Publications

TitleAbstractYear
Filter
PMID
Filter
cortisol content of eggs and larvae of teleosts.the whole-animal content of the cortisol was measured in embryos and larvae of tilapia (oreochromis mossambicus), rainbow trout (oncorhynchus mykiss), ayu (plecoglossus altivelis), milkfish (chanos chanos), and yellowfin bream (acanthropagrus latus) by radioimmunoassay following the validation of an extraction method. the total cortisol content in tilapia was 50.3 +/- 19.1 pg immediately following fertilization, then decreased abruptly and maintained a lower level of 10-17 pg until larval hatchi ...19921601267
laboratory evaluation of b-2 as a molluscicide in the control of the snail intermediate hosts of schistosomiasis in south africa.there is a continuous need for the development and evaluation of new, inexpensive but highly effective molluscides for the control of freshwater snails acting as intermediate hosts of schistomiasis. for this reason b-2 (hokko chemical industry co. ltd, japan), also called phebrol (sodium 2,5-dichloro-4-bromophenol), was evaluated in our laboratory as a candidate molluscicide for the control of freshwater snails in south africa. bulinus africanus and biomphalaria pfeifferi, intermediate hosts of ...19911796888
some unusual features of mycobacteriosis in the cichlid fish oreochromis mossambicus.adult, aquarium-reared oreochromis mossambicus (tilapia mossambica), which were naturally infected with mycobacterium marinum, displayed non-healing skin ulcers and other clinical signs considered to be typical of piscine mycobacteriosis. however, in addition, they frequently had melanotic foci in the skin and spleen, due to the presence of pigment cells surrounding the cutaneous and splenic inflammation. such melanotic foci have never been reported in response to mycobacteriosis. all fish also ...19902365849
endorphin and msh in concert form the corticotropic principle released by tilapia (oreochromis mossambicus; teleostei) melanotropes.hplc characterization of tilapia pituitary endorphins using an antibody specific for n-terminally acetylated endorphins yielded three major peaks in the neurointermediate lobe, but none in the pars distalis. the melanotropes secreted two of the immunoreactive products in vitro, one of which coeluted with xenopus laevis n-ac-beta-end(1-8). this immunoreactive fraction also coeluted with diacetyl-alpha-msh. evidence is presented that the noteworthy corticotropic potency of this hplc fraction, prev ...19957651900
neobenedenia girellae (hargis, 1955) yamaguti, 1963 (monogenea: capsalidae) from cultured marine fishes of japan.the monogenean neobenedenia girellae (hargis, 1955) yamaguti, 1963 is redescribed and reported for the first time in japan. the parasite was recovered from the body surface, fins, and occasionally from the eyes of 14 species, comprising 5 families of cultured marine fishes from several localities in southwestern japan. neobenedenia melleni (maccallum, 1927) sensu kaneko et al. (1988) from tilapia (oreochromis mossambicus) in hawaii is synonymized with this species. examination of original specim ...19957707197
brain creatine kinase activity during ontogeny of the cichlid fish oreochromis mossambicus and the clawed toad xenopus laevis, influence of gravity?the development of creatine kinase (ck) activity was studied in the brain of cichlid fish and clawed toads. the activity of ck in the whole brain of the fish decreases immediately after hatching (stage 6) from values of about 135 nmol substrate cleaved/mg protein/min to a value of about 105 at stage 8 (5 days post hatch at 20 degrees c). with the exception of a significant peak (125 nmol) between stages 9 and 10 (7 and 9 days respectively, post hatch at 20 degrees c) and a small intermediate pea ...19938457775
parasites of south african freshwater fish. vii. nematodes of some scaled fishes from the hartbeespoort dam, transvaal.the nematode parasites of 16 large-scaled yellowfish, barbus marequensis, six silverfish, barbus mattozi, six small-scaled yellowfish, barbus polylepis, 52 canary kurper, chetia flaviventris, 11 carp, cyprinus carpio, 45 mozambique bream, oreochromis mossambicus and a single-banded bream, tilapia sparrmani, caught in the hartbeespoort dam, transvaal, were collected, identified and counted. contracaecum spp. larvae were recovered from one o. mossambicus, 40 chetia flaviventris, three cyprinus car ...19947596571
urotensin ii-immunoreactive neurons in the caudal neurosecretory system of freshwater and seawater fish.antiserum generated against synthetic urotensin ii of the goby, gillichthys mirabilis, was used to localize urotensin ii in the caudal neurosecretory system in six species of freshwater teleosts: cyprinus carpio, carassius auratus, oreochromis mossambicus, oreochromis niloticus, salmo gairdneri and plecoglossus altivelis, and six species of seawater teleosts: acanthogobius flavimanus, pagrus major, parapristipoma trilineatum, trachurus japonicus, seriola dumerili and seriola quinqueradiata. in t ...19853884162
possible involvement of polysialogangliosides in nerve sprouting and cell contact formation: an ultracytochemical in vitro study.in cichlid fish (oreochromis mossambicus) primary cell cultures from whole brain and optic tectum, the differentiation-dependent distribution of polysialogangliosides on the outer cell surface has been followed on an ultrastructural level. for this, a two-step labeling technique with the monoclonal mouse antibody q211, recognizing a polysialoganglioside-associated epitope, followed by a secondary igm antibody, coupled to colloidal gold sols as an electron-dense marker, has been used. the gold gr ...19892723652
chronic inflammatory cells with epithelial cell characteristics in teleost fishes.certain cells that participate in the chronic inflammatory response of teleost fishes have many features typical of epithelioid cells of mammals. such features include high metabolic activity, frequent phagolysosomes, and cytoplasmic interdigitations between adjacent cells; however, the epithelioid granulomas formed in response to certain diseases in teleost fishes also have several features associated with epithelial cells. cases of ulcerative mycosis or acid-fast bacterial infection in atlanti ...19892686148
serotonergic neurons in the intestine of two teleosts, carassius auratus and oreochromis mossambicus, and the effect of serotonin on transepithelial ion-selectivity and muscle tension.the application of an antiserum directed against rat serotonin demonstrated serotonin-immunoreactive cell bodies and varicose nerve fibres in the myenteric plexus of both goldfish and tilapia. in the circular muscle layer immunoreactive varicose nerve fibres and a few cell bodies could be detected. a fine network of varicose fibres was observed underlying the epithelial cells. serotonin immunoreactivity was not observed along incoming mesenterial blood vessels, suggesting that the serotonergic n ...19892594202
metabolism of isolated fish gill cells: contribution of epithelial chloride cells.gill cell suspensions from freshwater (fw)- and seawater (sw)-adapted teleosts were obtained by density gradient centrifugation. the proportion of chloride cells (ccs) in the mixed cell suspensions was estimated using the fluorescent mitochondrial stain, daspmei, and ranged from less than 1% (fw-adapted tilapia) to approximately 13% (sw-adapted toadfish). the gill cells displayed relatively high viability based on trypan blue exclusion (greater than 75%), lactate dehydrogenase leakage (less than ...19892549165
effect of hypophysectomy, replacement therapy with ovine prolactin, and cortisol and triiodothyronine treatment on prolactin receptors of the tilapia (oreochromis mossambicus).the effects of hypophysectomy and subsequent replacement therapy with ovine prolactin (oprl) on specific binding of 125i-oprl to gill, kidney, and liver membranes of male tilapia were examined. the possible control of prolactin receptors by cortisol (f) and triiodothyronine (t3) was also studied using intact animals. in gill and kidney, hypophysectomy resulted in a significant decrease in specific binding that was partially restored (threefold increase) by three injections of oprl, suggesting a ...19902338218
prolactin receptors in liver, kidney, and gill of the tilapia (oreochromis mossambicus): characterization and effect of salinity on specific binding of iodinated ovine prolactin.specific binding of 125i-ovine prolactin (oprl) to microsomal fractions from gill, kidney, and liver of adult tilapia was determined. specific binding varied among tissues, the highest values being displayed by kidney membranes. in the liver, the binding of oprl was not strongly displaced by tilapia prolactins (tprl177 and tprl188), although tprl177 was six times more potent than tprl188. on the other hand, in kidney and gill membranes, the two tprls were equipotent. tilapia prls showed low pote ...19902338217
effect of thyroid hormones on hatching in the tilapia, oreochromis mossambicus.incubation of fertilized eggs of oreochromis mossambicus in media containing varying doses of t3, t4, and phenylthiocarbamide (ptc) indicated that the thyroid hormones delayed hatching, while the antithyroid drug accelerated it. denuded eggs were also incubated in the above media and the media were assayed at various time intervals for hatching enzyme. the thyroid hormones delayed hatching enzyme release, while ptc enhanced it. the possible role of thyroid hormones in the control of the hatching ...19912055445
the molluscicidal properties of apodytes dimidiata subsp. dimidiata (icacinaceae).the molluscicidal and piscicidal activity of extracts from the leaves, berries and bark of the tree apodytes dimidiata were evaluated experimentally. the leaves were highly toxic to both bulinus africanus and biomphalaria pfeifferi, the intermediate host snails of schistosoma spp. b. pfeifferi profusely exuded mucus which appeared to render some protection against the toxic substance(s) of the plant but did not prevent their eventual demise. the lc10 after one-hour exposures of fish (oreochromis ...19912051521
amino acid sequence of growth hormone isolated from medium of incubated pituitary glands of tilapia (oreochromis mossambicus).the amino acid sequence of tilapia (oreochromis mossambicus) growth hormone (gh) was determined directly by edman degradation of peptide fragments generated by lysyl endopeptidase and trypsin digestion. the n-terminal residue was deduced to be pyroglutamic acid through the use of pyroglutamyl aminopeptidase; its removal allowed amino acid sequence determination of the remainder of the n-terminal trypsin peptide by edman degradation. tilapia gh is composed of 187 amino acid residues and shows hig ...19912019405
insulin-like growth factor i-like immunoreactivity in serum and tissues of the tilapia, oreochromis mossambicus.tilapia serum was acidified with 0.5 m hcl and then chromatographed on an octadecasily-silica column. after washing with 4% acetic acid, the column was eluted with methanol. the eluate was evaporated to dryness. the sample cross-reacted in a human insulin-like growth factor i (igf-i) radioimmunoassay, suggesting immunochemical similarity to human igf-i. igf-i-like immunoreactivity was present at high levels in tilapia liver. other tissues containing igf-i-like immunoreactivity included the gonad ...19911930252
effect of edta on reduction of copper toxicity in oreochromis mossambicus (peters). 19989528709
residues of polychlorinated biphenyls (pcbs) in fish, water and sediment from shing mun river.the level and pattern of contamination by polychlorinated biphenyls (pcbs) were investigated in tilapia, oreochromis mossambicus (peters), sediment, and water from the shing mun river. the range of total pcbs was 12.9 ng/g to 181.6 ng/g wet weight in tilapia, 12.7 ng/g to 46.0 ng/g freeze-dried weight in sediment, and 3.8 ng/l to 13.6 ng/l in water. the effect of biomagnification was also observed, pcb concentrations increased from water to sediment to tilapia. pcb congeners occurred in such a w ...19911781935
metabolic effects of bovine growth hormone in the tilapia oreochromis mossambicus.1. bovine growth hormone (bgh) was injected into tilapia intramuscularly at a dose of 50 micrograms/100 g/day for a total of five injections. control fish received saline instead. 2. the serum concentrations of amino acid and glucose were significantly higher and hepatic glycogen concentration and glycogen synthetase activity significantly lower in the bgh-treated fish than those in the control fish. 3. the serum concentrations of protein, lipid and cholesterol, and the hepatic concentrations of ...19911679700
patterns of thyroxine and triiodothyronine in serum and follicle-bound oocytes of the tilapia, oreochromis mossambicus, during oogenesis.this study describes simultaneous measurements of thyroid hormones, thyroxine (t4) and triiodothyronine (t3), in the oocytes and serum of a female teleost fish over a complete reproductive cycle. we have identified patterns in circulating t4 and t3 levels as well as their accumulation into oocytes during the reproductive cycle of the tilapia (oreochromis mossambicus). this is the first description of the patterns with which thyroid hormones accumulate in teleost oocytes. the sampling strategy us ...19921577243
growth hormone binding sites in tilapia (oreochromis mossambicus) liver.125i-labeled bovine and tilapia growth hormones were used to assess the presence of growth hormone receptors in membranes prepared from tissues of the tilapia oreochromis mossambicus. the highest level of specific binding was detected in liver membranes from animals of both sexes and the binding was protein-dependent. tilapia growth hormone, bovine growth hormone, and ovine prolactin, but not tilapia prolactin, potently inhibited the hepatic binding of 125i-labeled bovine growth hormone. scatcha ...19921505720
identification of insulin-like growth factor-binding proteins in the circulation of four teleost fish species.insulin-like growth factor-binding proteins (igf-bps) were demonstrated in the circulation of four teleost fish species. in the coho salmon (oncorhynchus kisutch), serum binding of 125i-labelled human igf-i (125i-higf-i) was competitively inhibited by addition of excess recombinant bovine igf-i (rbigf-i) in a manner similar to that when rat serum was used. western-ligand blot procedure using the same labelled hormone identified at least three major forms of igf-bps in the plasma of all four tele ...19921380067
fishes of district sundargarh, orissa, with special reference to their potential in mosquito control.an extensive fish fauna survey was carried out in sundargarh, a malaria-endemic district in orissa, during 1988 to 1990 to identify and evaluate the indigenous larvivorous fishes for mosquito control. in all, 57 species belonging to 19 families under 6 orders were found in the local water bodies. on laboratory evaluation against anopheline and culicine larvae, six potential larvivorous fishes, viz. aplocheilus panchax, oryzias melastigma, oreochromis mossambicus, gambusia affinis, danio (b.) rer ...19921363317
an aquatic toxicological evaluation of fenthion in the context of finch control in south africa.queletox, containing fenthion as active ingredient, is the avicide formulation used in south africa to control red-billed finches (quelea quelea). control measures involve night spraying of roosting areas with a light aircraft. since roosting areas often include reedbeds along riversides and on islands, proper control is difficult without exposing the aquatic environment to some risk of contamination. this study tested the acute effects of fenthion, in association with the queletox formulation, ...19958521783
effects of acclimation to hypertonic environment on plasma and pituitary levels of two prolactins and growth hormone in two species of tilapia, oreochromis mossambicus and oreochromis niloticus.specific radioimmunoassays (rias) for the pair of tilapia prolactins (tprls) and growth hormone (tgh) were developed using antisera raised in rabbits. anti-tprl177 did not cross-react with tprl188 and tgh. anti-tprl188 did not cross-react with tprl177 and showed slight cross-reaction (3.1%) with tgh. anti-tgh showed negligible cross-reactions with tprl177 (0.4%) and tprl188 (1.6%). pituitary homogenates and plasma from oreochromis niloticus exhibited displacement curves parallel to the standards ...19938428646
diel variations in antibody response to bovine serum albumin in oreochromis mossambicus (peters).influence of time of antigen administration on antibody response to bovine serum albumin in the fish, o. mossambicus and variations in serum antibody titre during a 24 hr cycle are reported. significant variations were observed in magnitude of antibody response in groups of fishes immunized at different times of the day. magnitude of the response was maximal in fish immunized at 16 hr and minimal in those immunized at 4 hr. serum antibody titres in a 24 hr study also varied markedly with general ...19947959923
parasites of south african freshwater fish. vi. nematode parasites of some fish species in the kruger national park.the nematode parasites of 30 spot-tailed robbers, brycinus imberi, five tiger-fish, hydrocynus vittatus, 77 large-scaled yellowfish. barbus marequensis, two mudsuckers, labeo molybdinus, 114 catfish, clarias gariepinus, 46 silver barbel, schilbe intermedius, 66 squeakers, synodontis zambezensis, three eels, anguilla spp., 83 mozambique bream, oreochromis mossambicus, 81 red-breasted bream, tilapia rendalli swierstrae and 32 large-mouthed bream, serranochromis meridianus, caught in the sabie, cro ...19947898896
adrenocorticotropic hormone in relation to interrenal function during stress in tilapia (oreochromis mossambicus).this study examines acth-like immunoreactivity in the pituitary pars distalis and pars intermedia of the freshwater teleost oreochromis mossambicus (tilapia). two products (tactha and tacthb) were present in both lobes. these two products also accounted for the majority of the acth i.r. when in vitro pars distalis incubation medium was analyzed by hplc. in a homologous bioassay the two tilapia acth-like molecules and human acth1-39 possessed similar corticotropic potency. the peptides were quant ...19947883141
immunocytochemical and immunogold localization of two prolactin isoforms in the same pituitary cells and in the same granules in the tilapia (oreochromis mossambicus).the tilapia pituitary secretes two forms of prolactin (tprl) and a single growth hormone (tgh). the tprls share only 69% sequence identity and are designated tprl177 and tprl188 to indicate the number of amino acid residues in each isoform. our aim was to develop specific antisera for detection of these three related polypeptides. ten peptides corresponding to unique epitopes on the tprls and two peptides of tgh were synthesized using solid-phase methods, conjugated to carrier proteins, and used ...19937679085
modulation of humoral immune response by tannery effluent in oreochromis mossambicus (peters).fish were treated with various sublethal concentrations of tannery effluent. a concentration-dependent suppression of both primary and secondary antibody responses to bovine serum albumin (bsa) was observed after primary or secondary immunization. the fish were able to compensate the effluent-induced suppression of antibody response when the antigen (bsa) was administered along with an oil adjuvant.19958575812
cloning and sequence analysis of a hypothalamic cdna encoding a d1c dopamine receptor in tilapia.physiological and pharmacological studies have indicated that during acid stress a d1-like dopamine receptor becomes functional on intermediate pituitary melanocyte-stimulating hormone cells of tilapia (oreochromis mossambicus). as a first step towards physiological expression studies we isolated a d1-like dopamine receptor from a tilapia hypothalamus cdna library. construction of a phylogenetic tree of most of the d1-like receptors known in human, rat, xenopus, goldfish and drosophila revealed ...19968765745
gonadotropin-releasing hormone gene expression in teleosts.expression of multiple molecular forms of gonadotropin-releasing hormone (gnrh) mrnas and gnrh peptides were examined in the brains of tilapia (oreochromis mossambicus) and sockeye salmon (oncorhynchus nerka), using in situ hybridization histochemistry and immunohistochemical techniques. after otherwise identical conditions, lesser background and stronger gnrh hybridization signals were observed on cryostat vs. paraffin sections. in both fresh and bouin's-fixed paraffin-embedded tissues, there w ...19968883955
in situ hybridization for two differentially expressed gnrh genes following estrogen and triiodothyronine treatment in the brains of juvenile tilapia (cichlid).using in situ hybridization, messenger rnas for gonadotropin-releasing hormone (gnrh) were seen distributed differently in the brains of 40-day-old juvenile tilapia oreochromis mossambicus. while salmon-gnrh mrna was localized in the nucleus olfactoretinalis (terminal nerve ganglia), chicken ii-gnrh mrna mrna was observed in the midbrain nucleus. various concentrations (0.1-10 mg) of estradiol benzoate and triiodothyronine, given over a 24 h period, had no effects on mrna levels of salmon- and c ...19968945746
acute toxicity evaluation of the plant molluscicide, apodytes dimidiata (icacinaceae), to eisenia fetida (oligochaeta) and oreochromis mossambicus (cichlidae) in south africa.the crude aqueous leaf extract of a south african tree, apodytes dimidiata, has been identified as a potential molluscicide for snail control in anti-schistosomiasis programmes in rural communities. before preliminary field trials could be implemented its acute toxic effects on two non-target organisms were examined in accordance with the oecd guidelines to identify any potential hazards that might arise from the plant's use. laboratory results showed that working molluscicidal concentrations of ...19979083581
hypothalamic regulation of the pituitary-thyroid axis in the tilapia oreochromis mossambicus.electrolytic lesioning of the preoptic area resulted in an increase in plasma thyroxine (t4) and reverse triiodothyronine (rt3) 10 days later; plasma triiodothyronine (t3) levels were not affected, so that there was also a significant decrease in the t3:t4, but not rt3:t4, ratios. no significant changes in t4, t3, or rt3 levels were observed in fish with lesions in either the anterior or posterior portions of the lateral tuberal nucleus. the pituitary contents of growth hormone and the two prola ...19979126467
insulin-like growth factor i in the teleost oreochromis mossambicus, the tilapia: gene sequence, tissue expression, and cellular localization.using reverse transcription-pcr and molecular cloning, the complementary dna sequence encoding preproinsulin-like growth factor i (igf-i) of a teleost, the tilapia (oreochromis mossambicus) was established from liver. at the amino acid level, tilapia igf-i shows all residues necessary for the maintenance of tertiary structure and shares about 80% identity with igf-i from other teleosts. the b and a domains of tilapia igf-i show more than 90% homology to those of other teleosts and 86-93% to thos ...19979275043
the effects of cyanobacteria and the cyanobacterial toxin microcystin-lr on ca2+ transport and na+/k+-atpase in tilapia gillsthe effects of cytotoxic substances from cyanobacteria on ionic transport processes in tilapia (oreochromis mossambicus) were examined. inhibitory effects on ionic transport including whole-body ca2+ fluxes and p-type atpases of the gill were found. the compounds tested were (1) purified microcystin-lr (mc-lr), a heptapeptide hepatotoxin produced by the cyanobacterium microcystis aeruginosa, (2) extracts from m. aeruginosa strain pcc 7820, a strain producing mc-lr and other microcystin variants, ...19969319198
effects of ovine prolactin on calcium uptake and distribution in oreochromis mossambicus.ovine prolactin stimulated the net uptake rate of ca2+ from the water by 96%, produced frank hypercalcemia, and increased total bone calcium content in fed rapidly growing freshwater male tilapia, oreochromis mossambicus. it did not, however, alter the size of the readily exchangeable bone calcium pool. the increase in calcium accumulation resulted from an increase in whole-body ca2+ influx and a decrease in ca2+ efflux. it is concluded that prolactin exerts an important control over ca2+ exchan ...19863946634
plasma and urine levels of c18, c19 and c21 steroids in an asynchronous fish, the tilapia oreochromis mossambicus (teleostei, cichlidae).female and male tilapia, oreochromis mossambicus, were treated with luteinizing hormone-releasing hormone analogue (lh-rha) and pimozide (pim) or with human chorionic gonadotropin (hcg) to stimulate gonadal development and sexual maturation. plasma (both sexes) and urine (males) samples were collected periodically for steroid analysis by radioimmunoassay. plasma levels of estradiol-17 beta (3-6 ng/ml) and testosterone, higher in female (up to 25 ng/ml) than in male (6-13 ng/ml; p < 0.05), were i ...19969375364
partial cloning of the hormone-binding domain of the cortisol receptor in tilapia, oreochromis mossambicus, and changes in the mrna level during embryonic development.cortisol is one of the central hormones in osmoregulation in fish, especially in seawater adaptation. a cdna of 453 bp was cloned from liver mrna of freshwater-reared tilapia (oreochromis mossambicus), by reverse transcription polymerase chain reaction (rt-pcr) with primers designed for the hormone-binding domain of glucocorticoid receptors (grs) in mammals and rainbow trout. the sequence of pcr product has 83% homology to the trout gr at the nucleotide level and 92% at the amino acid level. the ...19979378267
evidence that gonadotropin-releasing hormone (gnrh) functions as a prolactin-releasing factor in a teleost fish (oreochromis mossambicus) and primary structures for three native gnrh molecules.three forms of gonadotropin-releasing hormone (gnrh) are isolated and identified here by chemical sequence analysis for one species of tilapia, oreochromis niloticus, and by hplc elution position for a second species of tilapia, o. mossambicus. of the three gnrh forms in o. mossambicus, chicken gnrh-ii (cgnrh-ii) and sea bream gnrh (sbgnrh) are present in greater abundance in the brain and pituitary than salmon gnrh (sgnrh). these three native forms of gnrh are shown to stimulate the release of ...19979390014
behavioural and biochemical investigations of the influence of altered gravity on the cns of aquatic vertebrates during ontogeny.quantitative data are presented on the influences of hyper-gravity (3 +/- 1g) and of simulated weightlessness (approximately 0g) during early ontogeny of cichlid fish (oreochromis mossambicus) and clawed toad (xenopus laevis, daudin) demonstrating changes in the swimming behaviour and the brain energy and plasma membrane metabolism. after return to 1g conditions, hyper-g reared fish and toads express the well known "loop-swimming" behaviour. by means of a computer based video analyzing system ...199411537932
early development in aquatic vertebrates in near weightlessness during the d-2 mission statex project.aboard the german-spacelab-mission d-2 the project "gravity perception and neuronal plasticity (statex ii)" was performed. statex is for statolith experiment. objects were growing tadpoles of the south african toad (xenopus laevis d.) and a juvenile cichlid fish (oreochromis mossambicus). the results give a broader base for the understanding of how environmental stimuli (e.g. linear accelerations) affect the development and function of the gravity perceiving systems in these two vertebrates. ...199611538629
fatty acids from the cyanobacterium microcystis aeruginosa with potent inhibitory effects on fish gill na+/k+-atpase activity.fatty acids from two strains of the cyanobacterium microcystis aeruginosa, pcc 7820 (a strain that produces the hepatotoxin microcystin-lr, mc-lr) and cya 43 (a strain that produces only small quantities of mc-lr), were extracted, partially characterised and tested for their inhibitory effect on the k+-dependent p-nitrophenol phosphatase (pnppase) activity of tilapia (oreochromis mossambicus) gill basolateral membrane. thin-layer chromatography of the lipids from dichloromethane:methanol extract ...19989390939
isolation and characterization of tilapia (oreochromis mossambicus) insulin-like growth factors gene and proximal promoter region.to understand the molecular mechanism which controls the transcription of the insulin-like growth factors (igfs) gene, we have cloned and sequenced the cdna for the proximal promoter region of the tilapia igfs gene and have characterized its activity by chloramphenicol acetyltransferase (cat) transient transfected expression assays. tilapia (oreochromis mossambicus) igf-i cdna (549 bp) was amplified by pcr from single-stranded cdna of growth hormone (gh)-induced liver rna using a pair of oligonu ...19989570153
3,5,3'-triiodothyronine (t3) clearance and t3-glucuronide (t3g) appearance kinetics in plasma of freshwater-reared male tilapia, oreochromis mossambicus.distribution and metabolism of the thyroid hormone 3,5, 3'-l-triiodothyronine (t3) were studied in several ways to gain insights into these processes in the warm water fish tilapia oreochromis mossambicus. trace doses of 125i-labeled t3 (t*3)1 were injected intraarterially, extraarterially, or intraperitoneally in freshwater-reared male tilapia to explore plasma clearance kinetic responses to these different input modalities. multicompartmental analysis of the plasma clearance data indicated a k ...19989679085
isoform expression of na+-k+-atpase alpha-subunit in gills of the teleost oreochromis mossambicus.three isoform-specific antibodies, 6f against the alpha1-isoform of the avian sodium pump, hered against the rat alpha2-isoform, and ax2 against the rat alpha3-isoform, were used to detect the expression of na+-k+-atpase alpha-subunits in gills of a teleost, the tilapia (oreochromis mossambicus). tilapia gill tissue showed positive reactions to antibodies specific for alpha1- and alpha3-isoforms. the results of immunoblots were converted to numerical values (relative intensities) by image analys ...19989728093
pentastomid infections in cichlid fishes in the kruger national park and the description of the infective larva of subtriquetra rileyi n. sp.during 1995, studies were conducted on the pentastome fauna of the cichlid fishes tilapia rendalli and oreochromis mossambicus in the kruger national park. the prevalence of infective pentastome larvae was 40.5% in t. rendalli and 9.2% in o. mossambicus. encapsulated nymphs of leiperia cincinnalis were taken from the mesentery, while sebekia wedli was either encapsulated or free-living in the swim bladder. the subtriquetrids moved about freely in the swim bladder. l. cincinnalis was present in 0 ...19989809320
molecular cloning of clc chloride channels in oreochromis mossambicus and their functional complementation of yeast clc gene mutant.we have cloned two members of the clc chloride channel family (omclc-3 and omclc-5) from gill cdna libraries of the euryhaline tilapia oreochromis mosammbicus. at the amino acid level, omclc-3 is 90.5% identical to rat clc-3 and omclc-5 is 79.2% identical to rat clc-5. ribonuclease protection assay revealed that omclc-5 was mainly expressed in the gill, kidney, and intestine in both freshwater- (fw) and seawater- (sw) adapted tilapia. although the mrna of omclc-3 was broadly expressed in tissues ...199910082675
structure and functional analysis of a tilapia (oreochromis mossambicus) growth hormone gene: activation and repression by pituitary transcription factor pit-1.a gene encoding the tilapia mossambica (oreochromis mossambicus) growth hormone (tigh) was isolated and sequenced. the gene spans 5.6 kb, including 3.7 kb of 5' and 0.2 kb of 3' flanking sequences and a 1.7-kb transcription unit comprised of six exons and five introns. the gene and the 5' flanking region contain several potential binding sites for pit-1, a key transcription activator of mammalian gh genes. one of these (-57/-42) is highly conserved in fish gh genes. it activates transcription in ...199910390158
biochemical and histopathological changes in certain tissues of oreochromis mossambicus (trewaves) under ambient urea stress. 199910423492
distribution and feeding efficacy of larvivorous fishes of goa.fifteen species of larvivorous fishes, viz. aplocheilus blockii, aplocheilus lineatus, rasbora daniconius, puntius vittatus, puntius melanampyx pradhani, puntius amphibius, macropodus cupanus, danio aequipinnatus. oreochromis mossambicus, heteropneustes sp, therapon jarbua, etroplus suratensis, mugil cephalus. osteochilichthys nashii and hypselobarbus dobsoni were collected from different parts of goa. their habitat wise distribution was studied and density was recorded. daily average consumptio ...199810497843
genomic organization of the oreochromis mossambicus glutamate receptor subunit 2 beta gene (fglur2 beta): presence of two different 5'-untranslated regions.the ampa (alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid)-preferring receptor is one of the pharmacologically defined ionotropic glutamate receptors, which mediate fast excitatory synaptic transmission in the central nervous system of vertebrates. here, we report the mapping of the transcriptional start points and identification of the intron-exon boundaries of the teleost ampa receptor subunit gene fglur2 beta. fglur2 beta and the mouse glur2 share a similar genomic organization, hav ...199910524256
a line2 repetitive dna sequence from the cichlid fish, oreochromis niloticus: sequence analysis and chromosomal distribution.we report the cloning and characterization of a long interspersed nucleotide element (line) from a cichlid fish, oreochromis niloticus, and show the distribution of this element, called ciline2 for cichlid line2, in the chromosomes of this species. the identification of an open reading frame in ciline2 with amino acid sequence similarity to reverse transcriptases encoded by line-like elements in caenorhabditis elegans, platemys spixii, schistosoma mansoni, gallus gallus (cri), drosophila melanog ...199910654084
oreochromis mossambicus (tilapia) corticotropin-releasing hormone: cdna sequence and bioactivity.although hypothalamic corticotropin-releasing hormone (crh) is involved in the stress response in all vertebrate groups, only a limited number of studies on this neuroendocrine peptide deals with non-mammalian neuroendocrine systems. we determined the cdna sequence of the crh precursor of the teleost oreochromis mossambicus (tilapia) and studied the biological potency of the crh peptide in a homologous teleost bioassay. polymerase chain reaction (pcr) with degenerate and specific primers yielded ...200010718913
leiperia cincinnalis sambon, 1922 (pentastomida) from nile crocodiles crocodylus niloticus in the kruger national park, south africa, with a description of the male.a single male and several adult females of the pentastomid leiperia cincinnalis were recovered from the trachea of five of six nile crocodiles examined in 1995 and 1998. infective larvae, pre-adult males and females, as well as mature males, occurred in clusters in the pulmonary artery but infective larvae and pre-adult females were also occasionally taken from the lungs. irrespective of the developmental stage, the intensity of infection was 3, 6, 48, 72 and 79. sixty-four percent of eggs recov ...200010937664
evidence for an osmoregulatory role of thyroid hormones in the freshwater mozambique tilapia oreochromis mossambicus.the existing equivocal reports on the osmoregulatory role of triiodothyronine (t(3)) and thyroxine (t(4)) in teleosts prompted a reinvestigation of their osmoregulatory function in the euryhaline teleost oreochromis mossambicus. evidence is presented for thyroidal involvement in hydromineral balance in freshwater tilapia. dose- and tissue-related responses to various t(3) and t(4) concentrations were observed in the branchial and renal tissues. the branchial na(+),k(+)-atpase activity, known to ...200011078627
the hexapeptide kp-102 (d-ala-d-beta-nal-ala-trp-d-phe-lys-nh(2)) stimulates growth hormone release in a cichlid fish (ooreochromis mossambicus).abstract studies in mammals have shown that synthetic met-enkephalin derivatives, called growth hormone-releasing peptides (ghrps), stimulate growth hormone (gh) release. the present study was conducted to determine whether the ghrp, kp-102, specifically stimulates gh release in a teleost. tilapia (oreochromis mossambicus) were given a single intraperitoneal injection of kp-102 (d-ala-d-beta;-nal-ala-trp-d-phe-lys-nh(2)) or bovine ghrh(1-29)-amide or vehicle and blood was sampled at 1, 6 and 12 ...200011115782
partial characterization of serum immunoglobulins of oreochromis mossambicus.serum immunoglobulins of o. mossambicus were purified using chromatography methods--cm affinity gel blue chromatography followed by two step purification involving a combination of ion-exchange and gel filtration chromatography. studies revealed that o. mossambicus produces only one class of high molecular weight macroglobulin as determined by molecular sieving by sepharose cl 6-b. immunoelectrophoresis of purified o. mossambicus serum against rabbit anti o. mossambicus serum gave only a single ...200011116524
the development of gravity sensory systems during periods of altered gravity dependent sensory input.gravity related behavior and the underlying neuronal networks are the most suitable model systems to study basic effects of altered gravitational input on the development of neuronal systems. a feature of sensory and motor systems is their susceptibility to modifications of their adequate physical and/or chemical stimuli during development. this discovery led to the formulation about critical periods, which defines the period of susceptibility during post-embryonal development. critical periods ...200314631632
differential effect of chromium compounds on the immune response of the african mouth breeder oreochromis mossambicus (peters).the objective of this study was to investigate the effect of trivalent (chromic chloride) and hexavalent (potassium dichromate) forms of chromium in the african mouth breeder oreochromis mossambicus (peters), with reference to the humoral immune response and lymphoid cells/organs. the 96 h ld50 for hexavalent and trivalent chromium was found to be 75 and 1,000microg fish(-1), respectively. groups of fishes were injected intraperitoneally with 10, 1, 0.1 and 0.01% ld50 hexavalent and trivalent fo ...200011185752
sodium and calcium balance in mozambique tilapia, oreochromis mossambicus, raised at different salinities.mozambique tilapia, oreochromis mossambicus, born and raised in five salinities, viz. (relatively soft) fresh water, 25, 50, 75% and full-strength sea-water, were analyzed for ionoregulatory performance (in particular sodium and calcium handling) and growth. this tilapia regulates its blood serum mineral composition rather effectively; however, in sea-water serum concentrations of sodium, chloride and calcium (in males only) were increased, as was the serum osmolarity. in sea-water, the total bo ...199811248987
isolation and characterization of myostatin complementary deoxyribonucleic acid clones from two commercially important fish: oreochromis mossambicus and morone chrysops.in mammals, skeletal muscle mass is negatively regulated by a muscle-derived growth/differentiating factor named myostatin (mstn) that belongs to the transforming growth factor-beta superfamily. although putative mstn homologs have been identified from several vertebrates, nonmammalian orthologs remained poorly defined. thus, we isolated and characterized mstn complementary dna clones from the skeletal muscle of the tilapia oreochromis mossambicus and the white bass morone chrysops. the nucleic ...200111250920
effects of glucocorticoids on cartilage growth and response to igf-i in the tilapia (oreochromis mossambicus).to study the effects of glucocorticoids and igf-i on the modulation of growth in the tilapia oreochromis mossambicus, we employed an epiceratobranchial cartilage radioisotope incorporation assay, wherein radiolabeled sulfate and thymidine uptakes are measured in vitro to indicate proteoglycan synthesis and cell proliferation, respectively. cartilage explants were cultured with cortisol or dexamethasone with or without recombinant bovine insulin-like growth factor-i. cortisol directly inhibited s ...200111254370
"critical periods" in vestibular development or adaptation of gravity sensory systems to altered gravitational conditions?1. a feature of sensory, neuronal and motor systems is the existence of a critical period during their development. modification of environmental conditions during this specific period of life affects development in a long-term manner, or even irreversibly. deprivation is the prefered approach to study the existence and duration of critical periods. for gravity sensory systems, space flights offer the only opportunity for deprivation conditions. 2. studies in a fish (oreochromis mossambicus) and ...200415260375
effects of estrogens in vitro and in vivo on cartilage growth in the tilapia (oreochromis mossambicus).to study the effects of estrogens on cartilage growth in the tilapia oreochromis mossambicus, an epiceratobranchial cartilage radioisotope incorporation assay was employed to measure proteoglycan synthesis and prechondrocyte proliferation by incorporation of radiolabeled sulfate and thymidine, respectively. cartilage explants were cultured with estrogens with or without recombinant bovine insulin-like growth factor-i (igf-i). in vitro experiments using the natural teleost estrogen, 17beta-estrad ...200111254371
immunostimulatory effect of azadirachtin in oreochromis mossambicus (peters).the effect of azadirachtin, a triterpenoid derived from azadirachta indica on the immune response was studied in the freshwater teleost, o. mossambicus. bovine serum albumin (bsa) and sheep erythrocytes (srbc) were used as antigens to evoke immune response. the immune responses in fish were measured by quantifying antibodies produced and counting the peripheral blood leucocytes in control and experimental fish. in general, azadirachtin significantly enhanced the antibody response and leucocyte c ...200011395951
on the influence of altered gravity on the growth of fish inner ear otoliths.inner ear stones (otoliths) of developing cichlid fish (oreochromis mossambicus) were marked with the calcium tracer alizarin-complexone (ac) at 1g-earth gravity before and after a longterm (20 days) stay of the animals at moderate hypergravity conditions (3g; centrifuge). ac deposition at the otoliths resulted in two fluorescence bands, which enclosed the area grown during exposure to altered gravity. this area was measured with regard to size and asymmetry (size difference between the left and ...199911542523
bacterial lipopolysaccharide (lps) modulates corticotropin-releasing hormone (crh) content and release in the brain of juvenile and adult tilapia (oreochromis mossambicus; teleostei).although immune endocrine interactions in teleost fish have been shown to involve adrenocorticotropin hormone (acth) and cortisol, the involvement of corticotropin-releasing hormone (crh) has not been demonstrated. the present study investigates whether treatment with bacterial endotoxin (lipopolysaccharide, lps) modulates brain crh contents or in vitro crh release in tilapia (oreochromis mossambicus). 10 days lps (escherichia coli) exposure of juvenile tilapia (4.5 weeks post hatch) via the amb ...200415557033
hepatocyte nuclear factors-1alpha, -1beta, and -3beta expressed in the gonad of tilapia (oreochromis mossambicus).hepatocyte nuclear factors (hnfs) are upstream regulators of many liver-specific genes and are involved in many cellular functions in the body, but their existence, expression, and function in gonads are still poorly understood. here we report on the first cloning of partial cdnas of hnf-1alpha and -1beta and full hnf-3beta cdna from a tilapia (oreochromis mossambicus) liver cdna library. the deduced amino acid sequence of tilapia hnf-3beta has a 90 to 96% identity with those of other fishes (dw ...200111688983
[ecophysiological adaptability of tropical water organisms to salinity changes].physiological response of tropical organisms to salinity changes was studied for some marine, estuarine and freshwater fishes (astyanax bimaculatus, petenia karussii, cyprinodon dearborni, and oreochromis mossambicus), marine and freshwater crustaceans (penaeus brasiliensis, penaeus schmitti and macrobrachium carcinus), and marine bivalves (perna perna, crassostrea rhizophorae, and arca zebra) collected from northeast venezuela. they were acclimated for four weeks at various salinities, and (1) ...200111795174
isolation and characterization of a homologue of mammalian prolactin-releasing peptide from the tilapia brain and its effect on prolactin release from the tilapia pituitary.in the tilapia (oreochromis mossambicus), as in many teleosts, prolactin (prl) plays a major role in osmoregulation in freshwater. recently, prl-releasing peptides (prrps) have been characterized in mammals. independently, a novel c-terminal rf (arginine-phenylalanine) amide peptide (carrasius rf amide; c-rfa), which is structurally related to mammalian prrps, has been isolated from the brain of the japanese crucian carp. the putative prrp was purified from an acid extract of tilapia brain by af ...200211884078
rat ghrelin stimulates growth hormone and prolactin release in the tilapia, oreochromis mossambicus.recently, ghrelin (ghr), a new peptide which specifically stimulates growth hormone (gh) release from the pituitary, was identified in the rat and human stomach. ghrelin has been shown to stimulate gh release by acting through a growth hormone secretagogue (ghs) receptor in the rat. the present study describes the in vitro effect of rat ghr on the release of gh and two forms of prolactin (prl(177) and prl(188)) in the tilapia, oreochromis mossambicus. rat ghr stimulated the release of gh in a do ...200212149581
experimental studies on the life-cycle of sebekia wedli (pentastomida: sebekidae).four young nile crocodiles (crocodylus niloticus) were infected with infective pentastome larvae obtained from naturally infected mozambique bream, oreochromis mossambicus, and red-breasted bream, tilapia rendalli swierstrai in the kruger national park. at day 95 post infection one of the crocodiles died and three female and four male s. wedli were recovered from its lungs. one pair was found in copula but the uteri of the females were not yet developed. males and females were of about equal siz ...199810192834
modulation of humoral immune response by ascorbic acid in oreochromis mossambicus (peters).fish were treated with sublethal doses of ascorbic acid before being immunised with different physical forms of bovine serum albumin (bsa). ascorbic acid elevates the antibody response to all the physical forms of bsa tested. generally, there was an inverse relationship between the dose of ascorbic acid and antibody response. in fish administered with multiple doses of ascorbic acid, no significant enhancement of antibody response was observed.199810356967
effect of sex ratio on the immune system of oreochromis mossambicus (peters).the social environment of fish has a crucial role to play on the immune system and hence on the overall health status. stressors of social origin such as dominance, subordination, and fight for mate have a major impact on the immune system of fish. the present study was designed with the objective of finding the effect of sex ratio of the population on the immune system of oreochromis mossambicus. groups of fish were maintained for 28 days in three different sex ratios i.e., (i) all-male (ii) al ...200616256305
influence of hypergravity on fish inner ear otoliths: ii. incorporation of calcium and kinetotic behaviour.larval siblings of cichlid fish (oreochromis mossambicus) were subjected to hypergravity (hg; 3 g, 14 days) during development. following the transfer to 1 g (i.e., stopping the centrifuge) they were separated into normally and kinetotically swimming individuals (the latter performed spinning movements). during hg, the animals were maintained in aquarium water containing alizarin-complexone (ac), a fluorescent calcium tracer. densitometric measurements of ac uptake into inner ear otoliths (optic ...200212528672
ambient salinity modulates the expression of sodium pumps in branchial mitochondria-rich cells of mozambique tilapia, oreochromis mossambicus.na,k-atpase (sodium pumps) provide the primitive driving force for ion transport in branchial epithelial cells. immunoblots of epithelial homogenates of both seawater (sw)- and freshwater (fw)-adapted tilapia gills as well as rat brain homogenate, a positive control, revealed one major band with a molecular weight of about 100 kda. sw-adapted tilapia gills possessed larger (about 2-fold) amounts of sodium pumps compared with fw-adapted tilapia gills. (3)h-ouabain binding representing functional ...200312560598
characterization of a piscirickettsiosis-like disease in hawaiian tilapia.in 1994, tilapia (oreochromis mossambicus and sarotherodon melanotheron) in wild and farmed populations on oahu, hawaii, usa, began to die of an unknown disease that was similar but not identical to piscirickettsiosis in salmonids. only tilapia were affected. diseased tilapia often swam erratically and had trouble staying at depth. scattered cutaneous haemorrhage and exophthalmia were often noted. in many cases, fish were found dead with no clinical signs. gills exhibited epithelial hyperplasia ...200312691196
immune response and disease resistance of oreochromis mossambicus to aeromonas hydrophila after exposure to hexavalent chromium.the objective of this study was to investigate the effect of chronic exposure to sublethal concentrations of hexavalent chromium (k2cr2o7) on the immune response and disease resistance of oreochromis mossambicus (peters) to bacterial aeromonas hydrophila infection. fish (45 to 50 g) were exposed to 0.005, 0.05, 0.5, and 5 mg l(-1) [0.01, 0.1, 1, and 10% lc50, respectively] of hexavalent chromium cr (vi) for 28 d. the specific immune response was assessed by antibody response to a. hydrophila by ...200616610584
nitrate removal in aquariums by immobilized pseudomonas.biological denitrification of nitrate to nitrogen gas was examined in a freshwater and a marine aquarium. nitrate removal in the aquarium water was accomplished with denitrifiers immobilized in a freeze-dried, alginate-starch matrix. starch served as a bacterial carbon source and cellular matrix-strengthening filler. freeze-dried beads were placed in canisters through which nitrate-rich aquarium water was recirculated. the freshwater aquarium (100 l) contained goldfish (carassius auratus) at a t ...200312790671
availability of in vitro vitellogenin assay for screening of estrogenic and anti-estrogenic activities of environmental chemicals.vitellogenin (vtg) protein, vtg mrna, other egg yolk proteins, vitelline envelope proteins and their mrnas are produced in the liver of oviparous species by stimulation of endogenous estrogen and exogenous estrogenic chemicals. the vtg assay based on enzyme-linked immunosorbent assay (elisa) has been widely used for many fish species to screen estrogenic and anti-estrogenic activities of chemicals and sewage effluents using immature fish and/or male fish. in order to reduce the number of fish fo ...200616883298
immunostimulatory effect of tinospora cordifolia miers leaf extract in oreochromis mossambicus.immunostimulatory effect of leaf extract of t. cordifolia on (i) specific immunity (antibody response), (ii) non-specific immunity (neutrophil activity) and (iii) disease resistance against aeromonas hydrophila was investigated in o. mossambicus. ethanol and petroleum ether extracts of the leaves were used. both ethanol and petroleum ether extracts administered at doses of 0.8, 8 or 80 mg/kg body weight, prolonged the peak primary antibody titres upto one to three weeks. ethanol extract at the d ...200616999027
identification of tilapia ghrelin and its effects on growth hormone and prolactin release in the tilapia, oreochromis mossambicus.we have identified ghrelin and cdna encoding precursor protein from the stomach of a euryhaline tilapia, oreochromis mossambicus. the sequence of 20-amino acid tilapia ghrelin is gssflspsqkpqnkvkssri. the third serine residue was modified by n-decanoic acid. the carboxyl-terminal end of the peptide possessed an amide structure. rt-pcr analysis revealed high levels of gene expression in the stomach and low levels in the brain, kidney and gill. tilapia ghrelin stimulated growth hormone (gh) and pr ...200312831762
acute toxicity and bioaccumulation of arsenic in tilapia (oreochromis mossambicus) from a blackfoot disease area in taiwan.the general objective of our work was to determine the acute toxicity and bioaccumulation of arsenic (as) in tilapia (oreochromis mossambicus) from the blackfoot disease (bfd) area in taiwan. the average concentration of as in pond water ranged from 17.8 to 49 microg l(-1). acute toxicity tests showed that the as concentration that caused toxicity to tilapia ranged from 69 060 microg as l(-1), in the 24-h toxicity test, to 28 680 microg as l(-1), in the 96-h toxicity test. we measured as concent ...200312900944
evaluation of impact of pah on a tropical fish, oreochromis mossambicus using multiple biomarkers.treatment of the widely occurring tropical cichlid, oreochromis mossambicus with a pure polycyclic aromatic hydrocarbon (pah), phenanthrene, induced a concentration-dependant formation of the enzyme, 7-ethoxyresorufin-o-deethylase (erod). concomittant increase (65-669%) in the activity of sorbitol dehydrogenase in the serum (ssdh) occurring with erod induction denoted liver cell damage, which was more severe in fish exposed to lower concentrations (0.4-4 microg g-1) of the chemical. in o. mossam ...200314505704
assessment of human health risks for arsenic bioaccumulation in tilapia (oreochromis mossambicus) and large-scale mullet (liza macrolepis) from blackfoot disease area in taiwan.this paper carries out probabilistic risk analysis methods to quantify arsenic (as) bioaccumulation in cultured fish of tilapia (orechromis mossambicus) and large-scale mullet (liza macrolepis) at blackfoot disease (bfd) area in taiwan and to assess the range of exposures for the people who eat the contaminated fish. the models implemented include a probabilistic bioaccumulation model to account for as accumulation in fish and a human health exposure and risk model that accounts for hazard quoti ...200314565585
cdna nucleotide sequence coding for stearoyl-coa desaturase and its expression in the zebrafish (danio rerio) embryo.a cdna sequence of stearoyl-coa desaturase (scd) was determined from zebrafish (danio rerio) and compared to the corresponding genes in several teleosts. zebrafish scd cdna has a size of 1,061 bp, encodes a polypeptide of 325 amino acids, and shares 88, 85, 84, and 83% similarities with tilapia (oreochromis mossambicus), grass carp (ctenopharyngodon idella), common carp (cyprinus carpio), and milkfish (chanos chanos), respectively. this 1,061 bp sequence specifies a protein that, in common with ...200314579408
development and validation of a radioimmunoassay for fish insulin-like growth factor i (igf-i) and the effect of aquaculture related stressors on circulating igf-i levels.this paper describes the development and validation of a commercially available radioimmunoassay (ria) for the detection of fish insulin-like growth factor-i (igf-i). the assay was developed using recombinant barramundi igf-i as antigen and recombinant tuna igf-i as radiolabelled tracer and standard. assay sensitivity was 0.15 ng/ml, inter-assay variation was 16% (n = 9) and intra-assay variation was 3% (n = 10). cross reactivity of less than 0.01% was found with salmon insulin, salmon igf-ii an ...200414723878
corticotropin-releasing hormone in the teleost stress response: rapid appearance of the peptide in plasma of tilapia (oreochromis mossambicus).high concentrations (up to 600 pg/ml) of corticotropin-releasing hormone (crh) were detected in plasma of the teleost fish oreochromis mossambicus (tilapia) when screening peripheral tissues of tilapia exposed to stress. notably, the plasma crh response to stressors in tilapia is much more pronounced than that in higher vertebrates, such as rats. after characterisation by ria, by spiking plasma with synthetic tilapia crh and by methanol-acid extraction, it is concluded that the immunoreactive (i ...200415012597
identification of the growth hormone receptor in an advanced teleost, the tilapia (oreochromis mossambicus) with special reference to its distinct expression pattern in the ovary.there is considerable evidence that the gh/igf-i axis plays an important role in female reproduction. we report the isolation and characterization of the gh receptor (gh-r) and its gene expression profile during oogenesis in the tilapia, oreochromis mossambicus. cdna encoding gh-r was cloned and sequenced from the tilapia liver. the predicted gh-r preprotein consisted of 635 amino acids and contained a putative signal peptide, an extracellular region with a characteristic motif, a single transme ...200415072567
immune response in the tilapia, oreochromis mossambicus on exposure to tannery effluent.the objective of the study was to investigate the effect of chronic exposure to sublethal concentrations of tannery effluent (te) on the specific immune response and nonspecific immunity in tilapia, oreochromis mossambicus. the effluent from the tannery was collected directly from a chrome-tanning factory situated in dindigul district, tamil nadu, india. apart from chromium (88.2 ppm), the effluent contained appreciable amount of calcium carbonate and sodium sulphate. groups of fish (45-50 g) we ...200717261332
hormone release is tied to changes in cell size in the osmoreceptive prolactin cell of a euryhaline teleost fish, the tilapia, oreochromis mossambicus.prolactin (prl) cells from a teleost fish, the tilapia, oreochromis mossambicus, facilitate the direct study of osmoreception. the release of two prolactins, prl(188) and prl(177), which act in freshwater osmoregulation in teleost fish, rises in vitro within 5 min after extracellular osmolality falls. an increase in cell size accompanied this rise. cell size and prl release also increased, albeit more slowly, following the partial replacement of medium nacl (55 mosmolal) with an equivalent conce ...200415242746
enhancement of nonspecific immunity and disease resistance in oreochromis mossambicus by solanum trilobatum leaf fractions.the purpose of this study was to determine the effect of water and hexane soluble fractions of the indian medicinal plant, solanum trilobatum on the nonspecific immune mechanisms and disease resistance in oreochromis mossambicus. fish were intraperitoneally injected with different doses of 0, 4, 40 or 400 mg kg(-1) body weight of water or hexane soluble fraction. the nonspecific immune mechanisms were assessed in terms of serum lysozyme activity, reactive oxygen species production and reactive n ...200717448687
oral administration of eclipta alba leaf aqueous extract enhances the non-specific immune responses and disease resistance of oreochromis mossambicus.immunostimulatory effects of the oral administration of the medicinal plant, eclipta alba leaf extracts was studied in tilapia, oreochromis mossambicus. for this purpose, fish were fed for 1, 2 or 3 weeks with diets containing e. alba leaf aqueous extract at 0, 0.01, 0.1 or 1% levels. after each week, non-specific humoral (lysozyme, antiprotease and complement) and cellular (myeloperoxidase content, production of reactive oxygen and nitrogen species) responses and disease resistance against aero ...200717499515
the use of different enzymes in feral freshwater fish as a tool for the assessment of water pollution in south africa.selected enzymes in the organs/tissues of two fish species (oreochromis mossambicus and labeo umbratus) were evaluated as biomarkers of water pollution in warm- and cold-water systems. the fish were caught using standard techniques during two high-flow and two low-flow surveys. the results indicated that the fluctuating enzyme activities measured were not a result of pollution but could be initiated as a result of (1) no or too little pollution, (2) handling of the fish, and (3) struggling in th ...200415327873
cdna cloning and functional expression of a ca2+-sensing receptor with truncated c-terminal tail from the mozambique tilapia (oreochromis mossambicus).the complete cdna sequence of the tilapia extracellular ca(2+)-sensing receptor (car) was determined. the transcript length of tilapia car (tcar) is 3.4 kbp and encodes a 940-amino acid, 7-transmembrane domain protein that is consistent in its structural features with known mammalian and piscine cars. the tcar extracellular domain includes a characteristic hydrophobic segment, conserved cysteine residues that are implicated in receptor dimerization (cys(129) and cys(131)) and in coupling to the ...200415456780
prevalence of neurotoxic clostridium botulinum type c in the gastrointestinal tracts of tilapia (oreochromis mossambicus) in the salton sea.tilapia (oreochromis mossambicus) have been implicated as the source of type c toxin in avian botulism outbreaks in pelicans (pelecanus erythrorhynchos, pelecanus occidentalis californicus) at the salton sea in southern california (usa). we collected sick, dead, and healthy fish from various sites throughout the sea during the summers of 1999 through 2001 and tested them for the presence of clostridium botulinum type c cells by polymerase chain reaction targeting the c(1) neurotoxin gene. four o ...200415465707
Displaying items 1 - 100 of 236