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inhibition of antigen-driven proliferative responses and enhancement of antibody production during infection with brugia pahangi.long standing brugia pahangi infections in seven dogs, restricted to one rear limb popliteal lymph node and its afferent ducts, were monitored with regard to proliferative responses and antibody production specific for a pbs extract of b. pahangi (bpa) by cells from infected and uninfected lymph nodes and by pbl. five of 10 dogs were negative for proliferative responses to bpa in node cells from infected limbs, yet they had positive pbl responses, and another was negative in both node cells and ...19911861067
altered adult worm location in young male jirds infected with brugia pahangi.male jirds (meriones unguiculatus) were inoculated subcutaneously with 100 brugia pahangi l3 each at 2, 6, 10, and 15 wk of age to compare their susceptibility and pathologic reactivity to infection. adult worm recoveries (mean +/- sd) ranged from 24.1 +/- 15.1 to 36.4 +/- 13.9 at 60 days postinfection. no significant difference in susceptibility was measured among the 4 age groups. jirds infected at 2 wk of age had significantly fewer (alpha less than or equal to 0.025) testicular and intralymp ...19911865273
mosquito host influences on development of filariae.a brief review is presented of the literature relating to factors which limit the capacity of filariae to develop in mosquitoes, with particular emphasis on immune mechanisms. most insects respond to bacterial infection by the production of potent antibacterial proteins, but little is known of this aspect of the immune response in mosquitoes or of the possible influence of immune proteins on the fate of filarial infections in mosquitoes. a summary account is given of recent experiments with the ...19911888212
antifilarial cellular responses detected in a haitian pediatric population by use of a microblastogenesis assay.previous reports have demonstrated age-related shifts in antifilarial humoral immune responses in 6- to 10-year-old haitian children; the responses consisted of elevated parasite-specific igg2 and igg3 in amicrofilaremic children and elevated igg4 in microfilaremic children. in this study, the cell-mediated immune responses to soluble adult and microfilarial extracts of brugia pahangi, determined by use of a microblastogenesis assay, were examined. capillary blood samples were collected by finge ...19911894942
depression of endothelium-dependent relaxation in aorta from rats with brugia pahangi lymphatic filariasis.a role for altered endothelial cell function is emerging in the pathogenesis of disease. we have previously demonstrated that dirofilaria immitis, the canine heartworm, depresses endothelium-dependent responses and alters the mechanism of relaxation in the in vivo femoral artery of infected dogs. exposure of rat aorta to the parasite or parasite-conditioned medium selectively depresses endothelium-dependent relaxation. d. immitis is closely related to the major human filarial pathogens. this stu ...19911903679
qualitative characterization of antibody responses to single and multiple brugia pahangi infections in jirds.antibody responses of jirds, singly and multiply inoculated with brugia pahangi infective larvae (l3), to soluble somatic extracts of adult parasites were characterized by western blot analysis. forty-two protein bands ranging in molecular weight from 12 to 160 kda were recognized by sera from infected jirds. antibody recognition of individual b. pahangi antigen bands in this assay appears to be independent of antibody enzyme-linked immunosorbent assay (elisa) titers to crude parasite extract, s ...19911919919
circulating filarial antigen in cats infected with brugia pahangi is indicative of the presence of adult worms.using counterimmunoelectrophoresis with rabbit antisera raised against soluble extracts of adult females of brugia pahangi parasite antigen was detected in the serum of all cats repeatedly infected with b. pahangi. antigen was never detected in uninfected cats. the antigen was associated with the presence of adult worms. antigen was detected consistently in a cat that was amicrofilaraemic but at autopsy harboured only two or three adult worms. conversely, some cats showed slowly declining number ...19911923565
experimental infection of humans with filariae.this report summarizes the findings of the 17 published studies involving humans who have been experimentally infected with filarial parasites. over the past 60 years, 45 individuals have been deliberately infected with wuchereria bancrofti, brugia malayi, brugia pahangi, loa loa, mansonella perstans, mansonella ozzardi, and/or onchocerca volvulus. the findings from these experimental infections of humans have helped define microfilarial survival and periodicity within human hosts, the prepatent ...19911962076
antibodies against the cuticlin of ascaris suum cross-react with epicuticular structures of filarial parasites.the insoluble cuticlin from the cortical zone of the cuticle of adult ascaris suum was purified and used to raise antibodies in c57/bl mice. the specificity of the antibodies for the external cortical layer was shown in the indirect immunofluorescence antibody test and by immunoelectronmicroscopy. a very high specificity for the external cortical layer was found. some cross-reactions with cuticular collagens occurred, and increased after booster immunizations. the anti-cuticlin antibody cross-re ...19901978533
the analysis of the 30 kda antigen of brugia pahangi and its interaction with the cuticle: a short review. 19901978536
cuticular proteins of brugia filarial parasites.surface-labelling techniques have been used to delineate a number of constituent molecules of the cuticle in adult stage brugia malayi and brugia pahangi. these molecules can be separated by virtue of their physical properties, and localised either by sequential solubilisation of intact cuticles or immunoelectron microscopy with relevant antisera. the major structural components of the cuticular matrix consist of a set of collagenous proteins of diverse molecular weight ranging from 36 to 160 kd ...19901978537
brugia pahangi in rats: increasing the number of infective larvae inoculated increases the percentage of microfilaremic rats.one hundred brugia pahangi infective larvae (l3) caused microfilaremic (mf + ve) infection in 56% of inbred pvg rats. adult worms were recovered consistently from infected rats but worm recovery was very low, only 1-3% of l3 inoculated survived to adulthood and the worms were dispersed in a wide range of anatomical sites. this suggested that lack of microfilaremia may be due to the low probability of male and female worms meeting in the same site and thus may be numerically and topographically b ...19911992091
the effect of ecdysteroids on the microfilarial production of brugia pahangi and the control of meiotic reinitiation in the oocytes of dirofilaria immitis.the effects of the ecdysteroids ecdysone and 20-hydroxyecdysone on microfilarial release in brugia pahangi and on meiotic reinitiation in the oocytes of dirofilaria immitis were studied. ecdysone was found to stimulate microfilarial release at 2 x 10(-6) m, but this effect was reduced at higher and lower concentrations. 20-hydroxyecdysone was found to have no such effect. in d. immitis, ecdysone at 10(-5) m was also found to overcome the period of meiotic arrest that occurs during the pachytene ...19911994372
2-acetylpyridine thiosemicarbazones. 13. derivatives with antifilarial activity.several members of a series of 2-acetylpyridine thiosemicarbazones possess in vivo and in vitro macrofilaricidal properties. the most promising of the group tested is n4-(2-aminophenyl)-2-[1-(2-pyridinyl)ethylidene]-hydrazinecarbothioam ide (4), which suppressed 100% of the macrofilariae of brugia pahangi and 94% of those of acanthocheilonema viteae in the jird at a dose of 25 mg/kg per day x 5. compounds 4 and 14 were also shown to inactivate or kill onchocerca gutturosa and onchocerca volvulus ...19912016717
brugia pahangi: circulating antibodies to adult worm antigens in uninfected progeny of homologously infected female jirds.serum igg antibody levels to adult brugia pahangi antigens were measured in uninfected offspring from uninfected and b. pahangi-infected female jirds. antibody titers to b. pahangi antigens in sera of offspring from infected females mimicked the maternal titer during the suckling period. neonate titers peaked at 2 weeks of age at levels as high as 1:4100, then decreased to levels well below maternal titers by 8-12 weeks of age. concurrent maternal and 2-week-old neonate sera recognized identical ...19912026218
studies on hexokinase from the filarial worms brugia pahangi, onchocerca gutturosa and o. lienalis. 19912027887
characterization of a beta-tubulin gene and a beta-tubulin gene products of brugia pahangi.a genomic clone containing a beta-tubulin gene from the parasitic nematode brugia pahangi was isolated. this gene was sequenced to determine its size, structural organization, and corresponding primary amino acid sequence. the coding sequence of the beta-tubulin gene spans 3.8 kb, is organized into 9 exons and expresses an mnra of 1.8 kb which codes for a protein of 448 amino acids. the predicted beta-tubulin amino acid sequence is 89%, 94%, 90% and 88% identical to the chicken beta 2, and the c ...19912052017
a direct fluorescence technique for the rapid detection of sheathed microfilariae in blood smears.thick and thin blood smears containing microfilariae of wuchereria bancrofti, loa loa, brugia malayi, brugia pahangi, brugia patei or acanthocheilonema viteae were prepared from either cryopreserved blood samples or from freshly collected blood, fixed in methanol and treated with a fluoresceinated lectin wheat germ agglutinin. sheathed microfilariae of w. bancrofti, l. loa, b. malayi, b. pahangi and b. patei in the blood smears could be easily detected and counted using a fluorescence assay. the ...19902074139
n-acetylation of serotonin, octopamine and dopamine by adult brugia pahangi.the metabolism of biogenic amines by the filarial worm, brugia pahangi, was investigated by incubating cut worms with radio-labelled amine substrates. two-dimensional thin-layer chromatography and analysis on two high-performance liquid chromatography systems showed that [14c]5-hydroxytryptamine was metabolised to a less polar compound that was identified as n-acetyl 5-hydroxytryptamine. n-acetyloctopamine and n-acetyldopamine were also formed when cut b. pahangi were incubated with [14c]octopam ...19902090941
[changes in the susceptibility of the recipient aedes aegypti to brugia pahangi after passive transfer of haemolymph].observations were carried out on the changes in the susceptibility of aedes aegypti (refm) to brugia pahangi after receiving haemolymph from both refractory (reprr) and susceptible (refm) aedes aegypti that were previously inoculated with microfilariae plus tc199 (tissue culture 199) or tc199 respectively. the melanization rates of microfilariae in the recipient mosquitoes were determined by dissecting the mosquitoes on day 3, 4 and 5 after haemolymph transfer. in the recipients receiving haemol ...19902099252
non-specific immune suppression by cd8+ t cells in brugia pahangi-infected rats.non-specific suppression of the immune response was investigated in brugia pahangi-infected lewis rats. the proliferative response of peripheral blood lymphocytes or splenic non-adherent cells to mitogens was significantly reduced by b. pahangi infection. the degree of hyporesponsiveness of splenic non-adherent cells to mitogens was comparable between microfilaremic and non-microfilaremic animals. the suppressed proliferative response of splenic non-adherent cells was restored by blocking with a ...19902148931
brugia malayi and brugia pahangi: transmission blocking activity of ivermectin and brugian filarial infections in aedes aegypti.brugia malayi- or brugia pahangi-infected, microfilaremic jirds (meriones unguiculatus) were treated with ivermectin at a single dose of 200 micrograms/kg body weight, administered subcutaneously. after different time intervals, aedes aegypti mosquitoes were fed on treated or untreated jirds. sausage stage, l2, and l3 larvae failed to develop in mosquitoes that fed on jirds from 15 to 30 days post-treatment. after 1 month, the numbers of l3 larvae recovered from mosquitoes fed on treated b. paha ...19902209785
species variation in mosquito flight-muscle damage resulting from a single filarial infection and its repercussions on a second infection.serial sections of females of two highly filaria-susceptible mosquitoes, aedes togoi and ae. aegypti, were examined by light microscopy. following a single brugia pahangi infection, the predominant reaction of flight muscles of ae. aegypti was degeneration, whereas that in ae. togoi was nuclear enlargement, a putative repair response. this also holds true following mechanical injury (beckett 1990), suggesting an inherent species difference in flight-muscle response to injury. the filariae of a s ...19902217122
brugia pahangi: effects of duration of infection and parasite burden on lymphatic lesion severity, granulomatous hypersensitivity, and immune responses in jirds (meriones unguiculatus).the effects of brugia pahangi infection duration and parasite burden on parasite-associated inflammatory and immune responses were determined over a 181-day period in jirds receiving from one to eight inoculations of infective larvae. multiple infections did not produce a protective resistance to reinfection as determined by adult worm recovery at necropsy. intralymphatic granulomatous lesions, lymph thrombi, were first seen at 48 days post initial inoculation (dpi). the numbers of lymph thrombi ...19902226701
comparative susceptibility to anthelmintics of brugia pahangi in jirds infected by different methods.it is possible to infect jirds with brugia pahangi by three methods. infective larvae (l3) can be injected either intraperitoneally (ip), when adults develop in the peritoneal cavity, or sub-cutaneously (sc), when they develop in the lymphatics or the heart and blood vessels associated with the lungs. alternatively adult worms which have been grown in the peritoneal cavities of jirds can be implanted into the peritoneal cavities of other jirds. this latter system has been widely used for screeni ...19902230033
selective breeding of dogs for segregation of limb edema from microfilaremia as clinical manifestations of brugia infections.three generations of beagles were monitored for microfilaremia (mf) and clinical disease during repeated infection with brugia pahangi and were selectively bred for offspring manifesting limb edema and low or amicrofilaremia. a high microfilaremic female mated to a high microfilaremic male produced 7 pups, 6 of which maintained mf greater than 1,000/ml for greater than 2 years after 5 monthly infections of 10 infective larvae each. an uninfected female mated to another high mf male produced 5 pu ...19902240373
differential humoral and cellular immunoreactivity to saline- and detergent-extracted filarial antigens.the immunoreactivity to saline- and detergent-extracted filarial antigens of 31 haitian subjects exposed to or infected with wuchereria bancrofti was analysed. cellular reactivity, monitored by blastogenesis in vitro, was significantly greater to a soluble extract of brugia pahangi than to a detergent-extracted antigenic preparation. in contrast, serum antibody levels against the detergent extract were significantly higher. these differences were consistently observed in symptomatic, microfilara ...19902260176
possible direct effect of diethylcarbamazine on the infective larvae of brugia pahangi.the direct action of diethylcarbamazine (dec) on the infective larvae of brugia pahangi was studied. the larvae were cultured in rpmi 1640 supplemented with foetal bovine serum and antibiotics for 22 days. most of the larvae remained alive for 8 days, but survival rate of larvae decreased rapidly from day 10 onwards. the larvae did not grow in the culture system. the addition of dec did not affect the morbidity of the larvae and no difference was observed in the morphological characteristics bet ...19902283470
age-related changes of the susceptibility to infection with brugia pahangi in male and female balb/c mice.effects of host age and sex on murine brugia pahangi infection were examined. in female balb/c mice, partial resistance to b. pahangi developed rapidly with age. in animals inoculated at 5-6 wk of age, resistance was about 2 times higher than in the youngest group (2-3 wk) and remained at a similar level through the study period (12 wk). male balb/c mice showed a similar tendency until 5-6 wk of age, but afterward their susceptibility increased with age. significant difference in the susceptibil ...19902319434
investigation of ecdysteroid excretion by adult dirofilaria immitis and brugia pahangi.the excretion of ecdysteroids by the filarial nematode species, dirofilaria immitis and brugia pahangi, was examined both in vitro, by the analysis of culture medium, and in vivo, through analysis of serum samples from experimentally infected hosts. there was no evidence of ecdysteroid excretion by intact parasites of either species in vitro. free ecdysteroids were detected in the serum of ferrets and dogs infected with d. immitis, but concentrations would be at or below the limit of detection i ...19902320053
in vitro killing of microfilariae of brugia pahangi and brugia malayi by eosinophil granule proteins.eosinophil infiltration and degranulation around the tissue-invasive stages of several species of helminths have been observed. release of eosinophil granule contents upon the worms is supported by localization of two of the major granule proteins, major basic protein (mbp) and eosinophil peroxidase (epo), on and around species of trematodes, nematodes, and cestodes. in the case of filarial worms, mbp is deposited on degenerating microfilariae (mf) of onchocerca volvulus. here, we performed in v ...19902324497
susceptibility of anopheles quadrimaculatus (diptera: culicidae) to subperiodic brugia malayi and brugia pahangi (nematoda: filarioidea) adapted to nude mice and jirds.anopheles quadrimaculatus and aedes aegypti (black-eyed liverpool strain) were fed on jirds and nude mice (jird-jird infection, jird-mouse infection, and mouse-jird infection) infected with subperiodic brugia malayi and b. pahangi. microfilariae of b. malayi from jird-mouse and mouse-jird infections developed normally in an. quadrimaculatus, whereas those from jird-jird infections did not develop. microfilariae of both species from jirds and nude mice developed normally in ae. aegypti and those ...19902332882
effect of ivermectin on filariae of mastomys natalensis.the efficacy of ivermectin (iv) was evaluated against four species of filariae, litomosoides carinii, acanthocheilonema viteae, brugia pahangi and brugia malayi in mastomys natalensis. animals with patent infections, induced with l3 larvae, by intravenous (iv) infusion of the respective microfilariae (mf) (5 x 10(4) mf per animal) or by intraperitoneal (ip) route (2 x 10(4) mf per animal) were used in this study. a single dose of iv (100 micrograms.kg-1) given subcutaneously (sc) to mastomys inf ...19902381895
brugia pahangi adults implanted into mice: a possible screen for filaricidal activity.brugia pahangi adults grown in the peritoneal cavities of jirds (meriones unguiculatus) were implanted into the peritoneal cavities of six inbred mouse strains to investigate this system as a screen for detecting filaricidal activity. the mice were given 15 adult b. pahangi and autopsied 35 days later. the recoveries of adult worms were 25%, 35%, 49%, 33%, 26% and 27% of the number implanted respectively for the mf1, to, nih, cba, balb/c and c3h/he strains. there was great variation in the numbe ...19902382104
the anthelmintic activity of a novel organic arsenical, r7/45, upon brugia pahangi in meriones unguiculatus.the new organic arsenical r7/45 is a rapidly acting and very potent anthelmintic against adult brugia pahangi in jirds. against adult worms implanted into the peritoneal cavity 5 subcutaneous (sc) injections at 2.5 mg/kg of r7/45 killed 100% of adult worms. a single dose sc of 20 mg/kg was 100% effective and 10 mg/kg 76% effective against adult worms. when jirds were autopsied at different times after treatment at 20 mg/kg sc 89% of worms were dead within three days. r7/45 was not active when gi ...19902387972
circulating parasite antigen in brugia pahangi-infected jirds.the mongolian jird is used widely in filariasis research for studies of protective immunity, pathogenesis, and therapy. the purpose of this study was to evaluate parasite antigen detection as a means of noninvasively monitoring brugia pahangi infection in jirds. a parasite antigen with mr of 105-110 kda was identified in sera from i.p.- and s.c.-infected jirds by immunoblot with a monoclonal antibody to phosphorylcholine. the same antibody was used in a direct sandwich enzyme immunoassay to meas ...19902405144
secreted and circulating antigens of the filarial parasite brugia pahangi: analysis of in vitro released components and detection of parasite products in vivo.a range of excretory-secretory (es) antigens have been characterised following in vitro culture of adult brugia pahangi filarial nematodes in serum-free medium. analysis by radioiodination, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and immunoprecipitation of purified macromolecules with antibodies from human and experimental animal infections reveals both host and parasite components. two host molecules appear by molecular weight and immunoprecipitation analysis to be immunoglob ...19852417115
brugia pahangi: stage-specific antigens on microfilariae detected by serum from infected jirds or by monoclonal antibodies.experiments were carried out to determine whether there are stage-specific antigens on microfilariae of brugia pahangi, using sera from mongolian jirds infected with b. pahangi and monoclonal antibodies against microfilariae of b. pahangi. these studies showed that microfilariae have both stage-specific and nonspecific antigens. the nonspecific antigens were also present on adult worms and on infective larvae. among monoclonal antibodies, 6 out of 14 clones produced antibodies against the microf ...19862417880
expression of cross-reactive surface antigens by microfilariae and adult worms of brugia pahangi during infections in cats.microfilariae of brugia pahangi were labelled with 125-iodine using the reagent iodogen. electron microscope autoradiographs of sections of iodinated microfilariae showed that the label was strictly confined to their sheath. adult worms were also iodinated by the same procedure. sodium dodecyl sulphate polyacrylamide gel electrophoresis (sds-page) analysis of detergent extracts of radio-labelled parasites revealed components of molecular weights 113, 81-71, 46 and 33 kda in microfilariae, and of ...19862432704
phosphorylcholine-bearing antigens in filarial nematode parasites: analysis of somatic extracts, in-vitro secretions and infection sera from brugia malayi and b. pahangi.a set of cross-reactive antigens is described which are present in somatic extracts and in-vitro secretions of the filarial nematodes brugia pahangi and b. malayi. a monoclonal antibody reactive with a repeating epitope on these molecules readily detects circulating antigen in the serum of animals infected with lymphatic filariae, using either an immunoradiometric assay or enzyme-linked immunosorbent assay (elisa). this epitope has the immunological reactivity and chemical characteristics of the ...19872436131
preliminary studies on the characterization of the mr 30,000 surface antigen of brugia pahangi. 19872439975
dynamics of immune responses related to clinical status in brugia pahangi-infected dogs.clinical signs of lymph node enlargement, limb edema, lymph duct fibrosis, and microfilaremia were monitored in dogs with chronic brugia pahangi infections. during the study a single rear limb of each dog was reinfected with multiple low doses of infective larvae. the changing immune responses to parasite antigens prepared from three sources--brugia pahangi adult worm homogenate extract, adult worm excretory-secretory products, and microfilaria excretory-secretory products--were monitored by wes ...19872440326
monoclonal antibody to a unique surface epitope of the human filaria brugia malayi identifies infective larvae in mosquito vectors.we describe properties of an igm monoclonal antibody (neb-d1e5) raised against the human filarial parasite brugia malayi. the antibody reacts with a stage- and species-specific determinant located on the surface of the infective-stage larva, as determined by indirect immunofluorescence. to use this reagent in epidemiological field studies, we developed an enzyme-linked immunoassay with which b. malayi larvae can be differentiated from other filarial parasites in mosquito vectors, including the m ...19872443912
regulation of jird lymphocyte responsiveness to fractionated antigens of brugia pahangi.the present studies were designed to characterize the in vitro responsiveness of jird lymphocyte populations to fractionated brugia pahangi antigens in the b. pahangi-jird model of filariasis. proliferative responses to spleen and lymph node cells from normal, b. pahangi-immunized, and infected jirds to hplc fractions of soluble and detergent extracted antigens were assayed. high molecular weight fractions of soluble b. pahangi were weakly mitogenic for normal lymph node, but not normal spleen c ...19882465563
egg production in brugia pahangi (nematoda: filarioidea).oogenesis in brugia pahangi has been studied by means of the aceto-orcein chromosomal squash technique and light-microscope autoradiography. the use of colchicine has demonstrated a 2-3 mm terminal germinative zone within the ovary, in which continuous and rapid mitotic division of germ cells occurs. in 80% of the gonads, oocytes within a 1-2 mm length of the ovary proximal to the germinative zone were at the prophase of meiosis i. primary oocytes with markedly less condensed chromatin, apparent ...19892470013
microfilariae of brugia pahangi in the blood of cats have variable levels of feline igg on their sheaths.feline igg was found on the sheath of microfilariae (mf) of brugia pahangi isolated from the blood of cats. gamma heavy chains, both light chains, and the fc and f(ab')2 portions of igg were present, suggesting that the molecule is intact. the amount of igg on the sheath was variable and the younger the mf the less igg was present on their sheaths. possible functions of this adherent layer of host protein are considered.19892494320
experimental brugia pahangi and b. malayi infections of callitrichid primates.the callitrichid primates, callithrix jacchus jacchus (the marmoset) and saguinus labiatus (the tamarin) were inoculated with infective larvae of brugia malayi and b. pahangi. microfilaraemia at low levels developed in 3 out of 4 c.j. jacchus infected with b. malayi and living or dead adult worms found in all 4. only one of 4 c.j. jacchus became microfilaraemic (mf + ve) when given b. pahangi and adults were found in two. of 4 s. labiatus given b. pahangi one became very lightly mf + ve and adul ...19892500478
respiration in the filarial nematode brugia pahangi.glucose-supported o2 uptake in the filarial nematode brugia pahangi was partially inhibited by antimycin a (30-40%), with the remaining activity being sensitive to o-hydroxydiphenyl or salicylhydroxamic acid (sham). the production of co2 by b. pahangi in the presence of d-glucose was stimulated by o2; the stimulation of co2; the stimulation of co2 production was sensitive to antimycin a. the o2 dependencies of respiration showed that the apparent o2 affinity for b. pahangi was diminished in the ...19892503459
brugia malayi and brugia pahangi: inherent difference in immune activation in the mosquitoes armigeres subalbatus and aedes aegypti.the inherent ability of brugia malayi and brugia pahangi (nematoda) to establish successful relationships with the mosquitoes armigeres subalbatus and aedes aegypti liverpool strain was evaluated. brugia pahangi microfilariae (mff) avoided the immune response and developed normally in a. subalbatus exposed to the parasite by an infective bloodmeal, whereas nearly 85% of b. malayi were destroyed by the immune response. because a. aegypti supports the development of both filarial worm species but ...19892563767
effects of intermediary metabolites and electron transport inhibitors on action of chloroquine on brugia pahangi and onchocerca volvulus.we examined the possibility that chloroquine is interfering with aerobic energy-generating processes in the adult filarial parasites, brugia pahangi and onchocerca volvulus. using motility of these parasites as an assay of drug effect, we found that micromolar concentrations of chloroquine caused significant paralysis, but only in alkaline medium (ph 8.4). the addition of 12 mm glutamine or 10 mm albizziin to the medium completely antagonized drug-induced paralysis. in addition, in b. pahangi, a ...19892597203
nucleotide sequence of brugia pahangi 17.4 kd protein. 19892602125
effects of potential inhibitors on brugia pahangi in vitro: macrofilaricidal action and inhibition of microfilarial production.a series of compounds that apparently disrupt hormonally regulated processes in insects have been examined for effects on the viability and microfilarial production of adult brugia pahangi cultured in vitro. the azasteroids, 25-azacoprostane and 25-azacholestane, inhibited the production of microfilariae at 5 ppm, the former also exhibiting macrofilaricidal activity at this concentration. the brassinosteroids examined inhibited microfilarial production at 5 ppm but did not affect worm viability. ...19892608313
comparison of glycolysis and glutaminolysis in onchocerca volvulus and brugia pahangi by 13c nuclear magnetic resonance spectroscopy.comparison of glycolysis in brugia pahangi and onchocerca volvulus by 13c nuclear magnetic resonance (nmr) spectroscopy showed that the former organism is predominantly a lactate fermenter and the latter resembles more closely the metabolism of a mixed acid fermenter producing lactate, succinate, acetate, ethanol, formate and carbon dioxide. both organisms synthesize glycogen as a storage carbohydrate. glutaminolysis in both organisms proceeds by the delta-amino-butyrate shunt to produce succina ...19892608314
diethylcarbamazine: inhibitory effect on acetylcholinesterase of dirofilaria immitis and brugia pahangi.anti-acetylcholinesterase activity of diethylcarbamazine (dec) was studied. acethylcholinesterase (ache) of adult worms of dirofilaria immitis, those of the 4th-stage larvae, early 5th-stage larvae and adults worms of brugia pahangi, and that of hamster brain tissue were all inhibited by dec. michaelis constant (km) of d. immitis and b. pahangi adult worm ache were 1.47 x 10(-4) and 1.81 x 10(-4) m respectively. dec was a competitive inhibitor of the filarial ache. inhibition constant (ki) for a ...19892609206
modulation of lymphocyte activation by soluble brugia pahangi extracts.both nonspecific and antigen specific immunological alterations are associated with the presence of circulating microfilariae in brugia pahangi infected jirds. t-cell growth factors are an essential element of an immune response; thus, modulation of the production or utilization of lymphokines by filarial antigens may be involved in these alterations. in the present study, the effect of soluble extracts of b. pahangi adult worms and microfilariae on the in vitro mitogen and antigen induced proli ...19892617042
the lymphatic pathology of chronic brugia pahangi infection in the dog.the dog infected with brugia pahangi is an excellent model for studying the clinical and immunological pathogenesis of lymphatic filarial infection and disease. dogs demonstrated a range of clinical changes including varying levels of microfilaraemia, episodic lymphadenopathy, lymphangitis, and limb oedema similar to the clinical spectrum reported in man. histologically, tissues from parasite-infected dogs were characterized by fibrosis of the lymph nodes and their afferent and efferent lymphati ...19892617630
studies on the biosynthesis and fate of ecdysteroids in filarial nematodes.experiments were performed to investigate whether adult dirofilaria immitis and brugia pahangi were capable of synthesising ecdysteroids from cholesterol or various intermediates from the biosynthetic pathway functioning in insects. metabolites of radioactively-labelled cholesterol and 5 beta-ketodiol (2,22,25-trideoxy-ecdysone) were detected in the filarial nematodes, but there was no radioactivity corresponding to ecdysteroid. uptake of tritiated 2-deoxyecdysone was poor and metabolism was not ...19892623425
heightened anti-filarial immune responsiveness in a haitian pediatric population.the immunological consequences of exposure to filarial infection were examined by cross-sectional serological studies. serum samples from 121 pediatric patients (18 months-15 years of age) were analyzed in parallel with a panel of sera from adults residing in the same area of haiti. parasite antigen specific igg and ige levels were determined by elisa. igg levels in children were significantly elevated in humoral immunoreactivity to brugia pahangi extracts compared to adults. in addition, anti-f ...19892641643
heat shock cognate 70 is a prominent immunogen in brugian filariasis.a cdna expression library constructed from rna derived from adult stage brugia pahangi (mixed sexes) was screened with pooled sera from chronic, amicrofilaremic cases of human lymphatic filariasis from the indonesian island of tanjungpinang, where brugia malayi is endemic. polyclonal antisera raised to purified beta-galactosidase fusion proteins from two of the most highly reactive clones identified a protein of mr 70,000 in all stages examined (microfilariae, l3 and adults) of both b. malayi an ...19892659668
filarial parasites exhibit unusually high levels of choline acetyltransferase activity.the presence of unusually high levels of choline acetyltransferase (chat, ec 2.3.1.6) in human and animal filarial parasites has been demonstrated. the levels of chat were highest in male worms of brugia malayi and brugia pahangi, with specific activities in crude extracts of about 2.27 and 1.26 mumol min-1 (mg protein)-1, respectively. the enzyme levels in these worms were over 10-20 times higher than in male worms of litomosoides carinii. the chat levels were about 2-5 times higher in male tha ...19892664508
colorimetric quantitation of filarial viability.a simple three-step colorimetric assay based on the tetrazolium salt mtt (3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) has been developed for quantifying filarial viability. living (but not dead) filariae take up mtt and rapidly reduce it to formazan, so staining themselves dark blue. this colour change which is easily seen provides a rapid qualitative test for filarial viability. quantitative data can be obtained by solubilizing formazan out of the worm with dmso and measuring ...19892707965
anti-filarial effects of nine quinoline-containing drugs on adult filariae in vitro.the potencies and efficacies of 9 quinoline-containing anti-malarials including chloroquine, (bis)desethylchloroquine, sn6911, sn12108, amodiaquine, cn-2999-2k, primaquine, quinacrine, and quinine were examined in vitro against adult female brugia pahangi. parasite motility and lactate excretion were measured as indicators of drug effects. all of the agents tested showed time-dependent increases in potency over a 24-72-hr incubation period. sn12108 was the most potent at 72 hr, reducing motility ...19892723923
effect of testosterone on the susceptibility of c57bl/6 mice to infection with brugia pahangi with reference to inflammatory cell response.effects of testosterone on the susceptibility and inflammatory cell responses of c57bl/6 mice infected intraperitoneally with brugia pahangi larvae were examined. on day 15 postinfection, female mice showed significantly greater resistance than did males, and peritoneal cell responses (lymphocytes, macrophages, and eosinophils) were great in females. castration of highly susceptible male mice increased their resistance and peritoneal cell responses to the level of female mice; whereas, castratio ...19892723929
effect of macrophage blockade on the resistance to a primary brugia pahangi infection of female balb/c mice.role of macrophages in the higher resistance of female balb/c mice than males to a primary brugia pahangi infection was investigated. macrophage blockade by carbon injection on the day of infection or by carrageenan injection one day before infection was effective to reduce the higher resistance of females to the level of males. the timing of macrophage blockade seems to be critical because carbon treatment on day 0 or 5 post-infection (pi) was much more effective than the same treatment on day ...19892740732
alteration in aedes togoi susceptibility to brugia pahangi microfilariae induced by aedes albopictus thoracic homogenate.refractoriness to brugia pahangi microfilarial infection could be induced in the normally susceptible aedes togoi mosquitoes by intrathoracic injection with crude thoracic homogenate of the refractory aedes albopictus mosquitoes. the crude thoracic homogenate contained three sephadex g-200 protein profiles of which the first profile showed strongest inhibition to the parasite development.19892772699
eosinophil hyporesponse of jirds induced by microfilariae of brugia pahangi.male jirds (meriones unguiculatus) were inoculated sc with 100 infective larvae of brugia pahangi. after 16 weeks, the animals were reinoculated with a comparable number of organisms. blood eosinophil responses during the 5 weeks subsequent to this attempt to reinfect were much lower than those of comparable naive animals, while the response to a heterologous infection (toxocara canis) was comparable to that of controls. mebendazole was given to infected animals for 2 weeks beginning 5 weeks (pr ...19892774064
the efficacy of 22,23-dihydroavermectin b1 (ivermectin) acting singly or in combination with a benzodiazepine on microfilariae of onchocerca species and brugia pahangi (an in vitro study).an in vitro study of the antinematodal action of two groups of compounds which act on the receptor complex of the inhibitory neurotransmitter, gamma-aminobutyric acid (gaba) in mammalian systems is described. the compounds, ivermectin and two benzodiazepines, diazepam and a water soluble midazolam were tested singly or in combination against two microfilarial parasites onchocerca lienalis (closely related to onchocerca volvulus) and brugia pahangi. the combination of ivermectin and diazepam at a ...19892775429
regulation of parasite antigen-induced t cell growth factor activity and proliferative responsiveness in brugia pahangi-infected jirds.previous studies have demonstrated that the induction of immunoregulatory mechanisms in the spleens of brugia pahangi-infected jirds is correlated with the onset of microfilaremia. this study investigated the relationship between production of a factor with il-2-like activity and the regulation of t cell-mediated responses in jirds experimentally infected with b. pahangi. a factor present in culture supernatants of mitogen-stimulated jird lymphocytes supported the proliferation of murine ctll ce ...19892783709
the role of macrophages on the expression of sex difference in the susceptibility to brugia pahangi infection in c57bl/6 mice.the role of macrophages or eosinophils on the expression of sex difference in the susceptibility to a primary brugia pahangi infection in c57bl/6 mice was investigated by using a macrophage blockade technique (carbon treatment) or a histamine type 1 (h1) receptor antagonist (promethazine). carbon treatment remarkably inhibited macrophage exudation, reduced the resistance of female mice, and completely abolished sex difference in the susceptibility to b. pahangi infection. although promethazine t ...19892794454
degranulated eosinophils, eosinophil granule basic proteins and humoral factors in nigerians with endomyocardial fibrosis.the frequency of eosinophilia, degranulated eosinophils, and raised serum levels of eosinophil granule basic proteins was determined in ten nigerians with emf and fifteen normal controls matched for age and sex, and from the same environment and social background as the patients. sera from the patients and control subjects were also examined for auto-antibodies, immune complexes, filaria antibodies and immunoglobulins. a mild eosinophilia was observed in four of the patients. the mean direct eos ...19872829606
in vitro motility of isolated adults and segments of onchocerca volvulus, brugia pahangi and acanthocheilonema viteae.observations were made on the spontaneous motility in vitro of entire adult worms and segments of onchocerca volvulus, brugia pahangi and acanthocheilonema viteae. segment motility was recorded in a mechano-transducer apparatus and responses of worm tissues to anthelmintics and other pharmacological agents were compared. entire adult female o. volvulus showed varied patterns of motor activity, ranging from continuous low level whole body motion to periodic spasmodic contractions interspersed bet ...19882852396
defense reactions of mosquitoes to filarial worms: potential mechanism for avoidance of the response by brugia pahangi microfilariae. 19852863311
turnover of the surface proteins of adult and third and fourth stage larval brugia pahangi.the turnover of surface proteins in adults, fourth-stage and third-stage larvae of brugia pahangi was measured using [125i]iodosulfanilic acid. groups of worms (n = 10 adult, 20 l4, 50 l3) were labelled and surgically implanted into the peritoneal cavity of naive jirds. the amount of radioactivity remaining on worms recovered over a 7-8 day period was determined. adult females showed no significant loss of label during a 7 day period. the recovery of fourth-stage larvae was low but the counts pe ...19862870432
susceptibility of mansonia mosquitoes to subperiodic brugia malayi and brugia pahangi. 19862874613
[humoral immune responses to stages of brugia pahangi in experimentally infected rats].in the present experiment, sprague-dawley rats were inoculated with brugia pahangi, a lymphatic dwelling filarial parasite. each rat received 100 third stage larvae (l3) of b. pahangi freshly harvested from aedes togoi. rats in the control group were injected with saline. after inoculation, tail vein blood was collected from each rat at 2-week intervals. the immune responses of the infected rats to b. pahangi were measured by the enzyme-linked immunosorbent assay (elisa). four types of antigen w ...19862880695
use of restriction fragment length polymorphisms (rflps) to distinguish between nematodes of pathogenic significance.the availability of restriction fragment length polymorphisms (rflps) would be useful for studying the extent of diversity among morphologically indistinguishable populations of filarial parasites. such polymorphisms may be useful in correlating various physiological and clinical differences with parasite heterogeneity. in order to identify such rflps, we isolated dna from microfilaria of 6 filarial species (acanthocheilonema viteae, brugia malayi, brugia pahangi, dirofilaria immitis, litomosoid ...19882897655
ph-dependent uptake and macrofilaricidal effects of chloroquine on adult filarial parasites in vitro.uptake and macrofilaricidal effects of chloroquine (cq) and other aminoquinolines were found to be highly ph dependent in brugia pahangi, acanthocheilonema viteae, onchocerca volvulus, and dirofilaria immitis. using [3h]cq, it was found that all of the parasites took up more drug under alkaline conditions (rpmi 1640 at ph 8.4) than in neutral (ph 7.4) or acidic (ph 6.8) media. differences were seen in the amount of drug taken up among the filariae studied. b. pahangi and a. viteae took up 7 time ...19892917628
characterization of tubulin from brugia malayi and brugia pahangi.the tubulins of brugia malayi and b. pahangi were similar with respect to concentration (mg tubulin per mg soluble protein), electrophoretic and isoelectric mobility, reaction in western blots with anti-tubulin monoclonal antibodies, and isoform patterns. tubulin was estimated to account for 2.8% and 2.9% of soluble protein in b. malayi and b. pahangi extracts, respectively. tubulins from brugia nematodes have been partially purified by polylysine agarose chromatography and with taxol. western b ...19892927443
identification, synthesis and immunogenicity of cuticular collagens from the filarial nematodes brugia malayi and brugia pahangi.the major structural proteins of the cuticle of the filarial nematode parasites brugia malayi and brugia pahangi were identified by extrinsic iodination and sensitivity to clostridial collagenase. at least 16 acidic components were identified in adult worms by 2-dimensional electrophoresis, with molecular weights ranging from 35,000 to 160,000. these proteins appear to be cross-linked by disulphide bonds, and localised in the basal and inner cortical layers of the cuticle. the outer cortex, cont ...19892927447
the induction of functional mononuclear and multinuclear macrophages in murine brugian filariasis: morphological and immunological properties.this present study describes the ontogeny and morphology of mononuclear and multinuclear macrophages in murine brugia pahangi infections. intraperitoneal infection with l 3 resulted in the development of adult worms and the production of microfilariae in many mice; however, all worms were usually removed by 100 days post infection (p.i.). the infection induced predominantly mononuclear and multinuclear macrophage responses in the peritoneal cavity, with maximum numbers of peritoneal cells being ...19852934789
the effect of brugia pahangi infection on survival of susceptible and refractory species of the aedes scutellaris complex.life table statistics were used to examine the survival functions of filarial susceptible and refractory species of the aedes scutellaris (walker) group of mosquitoes, following infection with high and moderate doses of brugia pahangi (buckley & edeson). survivorship curves and hazard function curves were generated, and the median survival times and the proportions of mosquitoes surviving beyond the extrinsic incubation period of the parasite were determined. in the susceptible populations of ae ...19872979549
in vitro haemagglutination and attenuation of microfilarial motility by haemolymph from individual blackflies (simulium ornatum) infected with onchocerca lienalis.two in vitro tests were used to investigate the effect of onchocerca lienalis stiles infection on the haemolymph of simulium ornatum meigen. the first of these examined the effect of infected haemolymph on the motility of fresh o. lienalis or brugia pahangi buckley & edeson microfilariae. incubation of haemolymph from individual flies with fresh microfilariae was performed in the wells of terasaki micro-tissue culture plates. motility of both species of parasite was found to be significantly att ...19882980161
cloning and comparison of repeated dna sequences from the human filarial parasite brugia malayi and the animal parasite brugia pahangi.a 320-base-pair repeated sequence was observed when dna samples from the filarial parasites brugia malayi and brugia pahangi were digested with the restriction endonuclease hha i. a 640-base-pair dimer of the repeated sequence from b. malayi was inserted into the plasmid pbr322. when dot hybridization was used, the copy number of the repeat in b. malayi was found to be about 30,000. the 320-base-pair hha i repeated sequences are arranged in direct tandem arrays and comprise about 12% of the geno ...19863003750
novel retinoid-binding proteins from filarial parasites.the present study deals with the discovery and partial characterization of specific binding proteins for retinol and retinoic acid from filarial parasites (worms of the superfamily filarioidea), including those from two species of onchocerca. these binding proteins, which are distinct in their physicochemical properties and in the mode of ligand interactions from the host-tissue retinoid-binding proteins, may be involved in the mediation of the putative biological roles of retinoids in the contr ...19853004410
characterization of a ribosomal dna clone of brugia malayi.the structure of ribosomal dna (rdna) clone pbmr7 from microfilariae of the human parasite brugia malayi has been examined in detail by southern blot analysis and s-1 mapping techniques. the results demonstrate that this clone contains regions homologous to 28s, 18s and 5.8s rdnas. a noncoding or 'spacer' region lies between the 3' end of 28s rdna and the 5' end of 18s rdna. an acci-sau3ai fragment of approximately 900 bp from this spacer region cross-hybridizes to genomic dna fragments of diffe ...19863012333
the effect of diethylcarbamazine treatment of bancroftian filariasis on the immunological reactivity of microfilaraemic individuals.patent filarial infection has been correlated with a profound suppression of humoral and cellular responses to filarial antigens. in the present study, the filarial antigen-specific humoral and cellular reactivity of 30 haitian subjects with patent wuchereria bancrofti infection was monitored before and after treatment with diethylcarbamazine. microfilarial density was reduced from a pre-treatment mean of 1778/ml to 9/ml, with residual microfilaraemias detectable in 10 subjects. peripheral blood ...19883075359
comparisons of glucose and amino acid use in adults and microfilariae of brugia pahangi.with [u-14c]glucose we confirmed that essentially all of the glucose carbon used aerobically by intact brugia pahangi adults was accounted for in the recovered lactate, in spite of the presence of cristate mitochondria in these parasites. approximately 0.2% of the glucose carbon that disappeared was recovered in co2. however, aerobiosis was required for the incorporation of alanine, proline, and glutamate into both respiratory co2 and protein, but the glucose was used on the order of 1000 times ...19883144711
dna base composition of filarial nematodes.we have determined the molar content of guanine + cytosine (gc content) of dna of the filarial nematode (brugia malayi, brugia pahangi and dirofilaria imitis) and of the free-living soil nematodes caenorhabditis elegans and have analysed the dna for the presence of methylcytosine. two independent methods, thermal denaturation and direct analysis of base content by hplc following enzymatic hydrolysis, reveal that the gc content of filarial nematodes is 26-28%. we have been unable to find methylcy ...19883174240
exsheathment of microfilariae of brugia pahangi in the susceptible and refractory strains of aedes aegypti.exsheathment of microfilariae of brugia pahangi was studied in susceptible (liverpool) and refractory (bora-bora) strains of aedes aegypti. it was found that the microfilariae tend to carry their sheaths into the haemocoel of both strains of ae. aegypti within two hours after the engorgement of mosquitoes from a rat parasitized by filariae. the percentage of sheathed microfilariae in the haemocoel then progressively decreased to 0% at eight hours and to 1% at 24 hours post-ingestion in the bora- ...19883178339
differential regulation of in vitro humoral and cellular immune responsiveness in brugia pahangi-infected jirds.patent filarial infection is associated with the downregulation of parasite-specific immune reactivity. in the present study, the relationship between in vitro parasite antigen-specific humoral and cellular immune responsiveness was investigated in brugia pahangi-infected jirds and in jirds immunized with soluble antigens. spleen cells from b. pahangi-immunized jirds or from jirds with prepatent infections mounted significant in vitro proliferative and antibody responses to b. pahangi. the antig ...19883182070
cloning and characterization of a species-specific repetitive dna sequence from onchocerca armillata.two clones, poa1 and poa5, have been isolated from a genomic dna library prepared from pools of onchocerca armillata adults in the plasmid vector puc12. in dot-blot hybridisations, these two clones do not cross-hybridise significantly with total genomic dna from o. volvulus, o. gutturosa, o. ochengi, o. gibsoni, o. lienalis, bovine, human, culicoides nubeculosus, simulium species or brugia pahangi, but do hybridise with as little as 100 pg of dna from two separate geographic isolates of o. armil ...19883185612
further evidence of both humoral and cellular encapsulations of sheathed microfilariae of brugia pahangi in anopheles quadrimaculatus. 19883192354
failure of the h2 antagonist cimetidine to reverse parasite antigen-specific lymphocyte unresponsiveness in experimental filariasis.histamine is known to mediate potent immunosuppressive effects on lymphocyte function. in jirds infected with brugia pahangi decreased mitogen and parasite antigen responsiveness are associated with the presence of histamine binding regulatory cells. the present study was thus designed to investigate the immunoregulatory role of histamine in experimental filariasis. spleen cells from normal or b. pahangi infected jirds were incubated with bsa or histamine coupled sepharose beads and the degree o ...19883219801
clearance of brugia pahangi microfilariae in immunized mice.active brugia pahangi microfilariae (mf) were injected into naive male balb/c mice intraperitoneally. microfilaraemia was studied for 28 days; and mf circulated in blood in optimum numbers from 3 to 14 days. anti-mf response was assessed by the rate of disappearance of mf from blood as well as their absence from visceral organs. sonicated antigens of mf (mfe) and whole worm extract of adults (wwe) induced absolute protection against the establishment of mf in mice. this potent anti-mf response e ...19883224990
the effect of diethylcarbamazine on the in vitro serum-mediated adherence of feline granulocytes to microfilariae of brugia pahangi.the effect of the antifilarial drug diethylcarbamazine (dec) on immunologically mediated destruction of the microfilariae (mf) of brugia pahangi in vitro is addressed by studying the drug's influence on the granulocyte adherence to the surface of mf and the subsequent death of these parasites. dec enhanced the adherence of cat blood-derived granulocytes to the surface of mf through the meditation of cuticle direct antibodies but not that mediated by complement alone; the parasites became immobil ...19883227233
comparative effects of anthelmintics on motility in vitro of onchocerca gutturosa, brugia pahangi and acanthocheilonema viteae.the effects of standard anthelmintics on the motor activity in vitro of adult onchocerca gutturosa, brugia pahangi and acanthocheilonema viteae were determined using a micromotility meter. fresh adult males dissected from bovine tissues were the best source for observations on o. gutturosa. parasites liber-ated by collagenase digestion showed poor viability and motility. only segments of o. gutturosa females were obtainable by dissection and these were not able to sustain motility in vitro. adul ...19883227249
pathologic changes and immunologic responses in brugia pahangi infected dogs. 19883236903
macrofilaricidal activity of oral flubendazole on brugia pahangi.the macrofilaricidal effect of orally administered flubendazole on brugia pahangi was studied in the multimammate rat, mastomys natalensis. a micronized formulation was incorporated in the routine feed for 2 weeks, starting 16 weeks after infection. in the treated rats the microfilarial density dropped to zero 20 weeks after infection, whereas it remained high in untreated animals. when killed between 40 and 41 weeks after infection, the treated group yielded a mean of 2 male and 0.16 female wor ...19883256991
complement activation by eggs and microfilariae of filarial parasites.the complement of fresh normal rat serum was activated by filarial eggs and microfilariae (mf). c3 was deposited on the surface of litomosoides carinii, brugia pahangi, brugia malayi and dipetalonema viteae as seen by immunofluorescence. intra-uterine and in vitro-derived mf did not bind c3. in contrast, c3 bound to the blood-derived mf of b. pahangi and b. malayi as well as exsheathed mf of l. carinii and b. malayi. significant consumption of complement was observed with eggs of all filarial sp ...19873325408
cloned antigen genes of brugia filarial parasites.human lymphatic filariasis is a chronic, potentially debilitating disease caused by brugia and wuchereria species of parasitic nematodes. the spectrum of clinical manifestations appears to be related to the immune response of individuals to invasive larvae, adult worms and circulating first-stage larvae (microfilariae). potential immunopathological outcomes place constraints on vaccine development, emphasizing the need to understand the basis of immunity and pathology. clones coding for a number ...19873332770
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