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membrane changes during growth of tetrahymena in the presence of ethanol.after a brief lag period for acclimation, tetrahymena pyriformis, strain nt-1, is capable of growing in culture medium containing high levels of ethanol. when grown in a medium having 1.6% ethanol, the membrane phospholipid composition was significantly different from that of control cells. the principal changes included a reduction in hexadecenoic acids (16 : 1 and 16 : 2) from 23% to 5% and an increase in linoleic acid (18 : 2) from 14% to 25% similar but less pronounced changes were observed ...1979105757
a novel tetrahymena sp. with unusual membrane lipid composition, with special reference to iso fatty acyl chains.a novel tetrahymena sp. is similar in appearance to four classical strains (wh-14, gl, w, nt-1) of t. pyriformis except for a larger width. the phospholipid and acyl chain compositions of membranes of this novel species are significantly different from those of other strains. the tetrahymena sp. has a much higher content of ethanolamine phosphoglyceride and a lower level of glyceroaminoethyl phosphonate. major fatty acids of this strain are iso 15:0 and iso 17:1, which are, if present, usually m ...1978107352
new serotypes of group b streptococci isolated from human sources.antisera raised in rabbits against two nontypable group b streptococci, which were not agglutinable in a specific group b antiserum, were tested with acid extracts of 78 nontypable human group b streptococci. one antiserum (12351) reacted with 15 strains, and the other (7271) reacted with only 2 strains. antiserum to wilkinson's strain ss 1169 (nt 1) reacted with three strains. antiserum against strain 12351 appears to be a useful antiserum against a new type antigen, which is probably polysacch ...1979115895
mechanism of thermal adaptation of membrane lipids in tetrahymena pyriformis nt-1. possible evidence for temperature-mediated induction of palmitoyl-coa desaturase.the regulatory mechanism of a key enzyme, palmitoyl-coa desaturase, involved in the adaptation to temperature shift was investigated by labeling tetrahymena pyriformis cells with [14c]palmitic acid. the rate of conversion of [14c]palmitate to [14c]palmitoleate was shown to be dependent on incubation temperature and also to be maximal at 2 h after the shift 39.5 to 15 degrees c. addition of cycloheximide before the temperature shift produced no increase in desaturation of [14c]palmitate after the ...1978416850
an ecological study of bacteriophages of vibrio natriegens.effects of temperature and anaerobic conditions on the replication of two bacteriophages, nt-1 and nt-6, of the estuarine bacterium vibrio natriegens were studied. reduction in temperature resulted in longer latent periods and reduced burst sizes for both phages. replication under anaerobic conditions resulted in longer latent periods; however, phage nt-6 had a reduced burst size, whereas phage nt-1 had an increased burst size, resulting in a rate of phage production nearly equal to that observe ...1978647480
a family outbreak of serious streptococcal infection.a localized outbreak of scarlet fever was caused by an m-nontypable t-1 (nt/1) group a beta-hemolytic streptococcus. the result was a fatal outcome in a 5-year-old child and a near fatality in his 10-year-old sibling. the outbreak was confined to family units that had members with whom the children were close playmates. extensive epidemiologic studies in neighborhood schools and local hospital emergency rooms did not demonstrate a disemination of the causative serotype in the community.1976781335
physiology and ecology of bacteriophages of the marine bacterium beneckea natriegens: salinity.the effects of variation in ionic levels on the stability and replication of two bacteriophages (nt-1 and nt-6) host specific for the marine bacterium beneckea natriegens were examined. monovalent cations influenced the adsorption of the nt-1 but not the nt-6 phage; however, one-step growth studies showed that nacl was required for replication of both phage. the nacl optimum for nt-1 production was 0.25 m nacl, the same as the growth optimum for b. natriegens. however, the optimum for nt-6 produ ...1976938035
[characteristics of group a streptococci isolated from children with non-suppurative complication or severe infection].we determined the characteristics of group a streptococci isolated from 29 sporadic cases with non-suppurative complication or severe infection during a 15-year period from 1977 to 1991. the clinical diagnoses of children included 4 patients with rheumatic fever, 2 with reactive arthritis, 2 with central nervous system complication, 5 with glomerulonephritis, 11 with honoch-schölein purpura, 4 with sepsis and 1 with empyema. twenty-four strains were isolated from throat swabs, 4 from blood speci ...19921294649
heterogeneity within the nonstructural protein 5-encoding region of hepatitis c viruses from a single patient.nucleotide (nt) sequence heterogeneity of the hepatitis c virus (hcv) genome derived from a single carrier was investigated. a polymerase chain reaction (pcr) product of 311 bp in the putative nonstructural protein 5-encoding region was directly sequenced, while part of a pcr product was cloned, and sequence analyses were carried out for 27 independent clones. although 14 of the 27 clones were conserved, ten other types of nt sequences were found. the difference was at most 3 nt (1.1%). a direct ...19921322345
a silencer-like cis element for the testis-specific phosphoglycerate-kinase-2-encoding gene.phosphoglycerate kinase (pgk), a glycolytic enzyme, possesses two isozymes: somatic-type pgk-1 and testis-specific pgk-2, encoded by distinct genes. tissue-specific expression of the two pgk-encoding genes (pgk) seems to be transcriptionally controlled, since tissue distribution of the mrnas coincides well with that of the proteins. in the present study, we determined the cis-acting dna elements that regulate the transcription of mouse pgk-2. a transient expression assay of dnas having various p ...19921398112
molecular screening and fetal diagnosis of beta-thalassemia in the italian population.this paper reports our experience of molecular screening and fetal diagnosis of beta-thalassemia in 457 at risk couples of italian descent. molecular screening was carried out by dot blot analysis on amplified dna with oligonucleotide probes complementary to the eight most common mutations in italians [beta zero 39 (c----t); beta zero 6 (-a); beta+ -87 (c----g); beta+ ivsi nt 110 (g----a); beta zero ivsi nt 1 (g----a); beta+ ivsi nt 6 (t----c); beta zero ivsii nt 1 (g----a); beta+ ivsii nt 745 ( ...19921511973
heterozygous beta-thalassemia: relationship between the hematological phenotype and the type of beta-thalassemia mutation.in this study we have correlated the severity of the hematological features to the type of the beta-thalassemia mutation [codon 39 (c----t), ivs-i nt 110 (g----a), ivs-i nt 1 (g----a), ivs-i nt 6 (t----c), ivs-ii nt 745 (c----g), -87 (c----g) and beta 6 (-1 bp)], in a group of beta-thalassemia heterozygotes of italian descent in whom we excluded the presence of iron deficiency or deletion alpha-thalassemia. the beta-thalassemia mutation was defined by dot blot analysis on amplified dna with alle ...19921536137
human mast cell proteases hydrolyze neurotensin, kinetensin and leu5-enkephalin.purified mast cell carboxypeptidase cleaved the c-terminal leucines from leu5-enkephalin (leu-enk), neurotensin (nt), and kinetensin (kt), with km values of 36, 16, and 15 microm, and kcat values of 44, 51, and 53 s-1, respectively. to better predict potential in vivo hydrolysis products generated by mast cell proteases, these peptides were incubated with released skin mast cell supernatants. leu5-enkephalin was hydrolyzed only by carboxypeptidase. kinetensin was cleaved by tryptase, chymase, an ...19911800960
neurotensin and neuromedin n elevate the cytosolic calcium concentration via transiently appearing neurotensin binding sites in cultured rat cortex cells.through assessment of the changes in the intracellular free-calcium concentration ([ca2+]i), which was measured using the calcium sensitive dye, fura-2, the character of the neurotensin (nt) binding sites which appeared transiently during the early ontogenetic stage in the rat cerebral cortex was analyzed in primary cultures of cerebral cortex cells from neonatal rats. nt (1-1000 nm) elevated [ca2+]i of the cells even when extracellular calcium was chelated with 1 mm ethylene glycol-bis(beta-ami ...19911849803
the electrophysiological actions of neurotensin in the central nervous system.the endogenous neuropeptide, neurotensin (nt) alters the firing frequencies of certain neurons in the central nervous system (cns). this is one of the findings that support the hypothesis that nt is a neurotransmitter substance. the direct application of nt on cns neurons causes predominantly excitatory effects. these effects occur in a dose-related fashion via a calcium-dependent postsynaptic mechanism. the c-terminal hexapeptide fragment, nt 8-13 exerts similar electrophysiological effects to ...19911890928
ontogeny of neurotensin in the fetal sheep.neurotensin (nt) is a regulatory peptide involved in the control of gastrointestinal function. we have used the chronically cannulated ovine fetus to examine the ontogeny of circulating nt-like immunoreactivity (ntli) in the fetus and neonatal lamb. in addition the placental transfer and clearance of nt has been determined. ntli in the ovine fetus circulates at adult concentrations during the third trimester of pregnancy and is of fetal origin. ntli is present in the fetal ileum, the richest sou ...19911797922
dynamics of neurotensin stores in the stellate ganglion of the cat.neurotensin (nt) within the stellate ganglion (sg) of the cat is present in axon terminals of extrinsic, presumably preganglionic, neurons and may play a role in ganglionic transmission. nt content of the sg, and of the preganglionic axons which innervate it, was determined by radioimmunoassay in the anesthetized cat under various experimental conditions in order to understand the factors determining the size of the ganglionic nt stores. the immunoreactive nt (int) from extracts of sg and its pr ...19911773341
rapid degradation of neurotensin by stimulated rat mast cells.a ria towards neurotensin (nt) using c-terminal- and n-terminal-specific antisera was used to study degradation of this tridecapeptide by isolated rat mast cells. incubation of nt (10 microm) with peritoneal or pleural mast cells resulted in a rapid loss of nt immunoreactivity (int), as measured by c-terminal-directed antiserum, with little effect on n-terminal int. the rate of the reaction was faster with pleural cells (t1/2, 30 s) than with peritoneal cells (t1/2, 180 s) and was greater than 1 ...19911726119
kinetics of sodium-lithium countertransport in normotensive and hypertensive subjects.the kinetic parameters vmax and km of erythrocyte sodium-lithium countertransport (na-li ct), and the lithium cell to plasma ratio (li c:p) measured 24 h after a 1-g oral dose of li2co3, were determined in 14 normotensive (nt) and 14 untreated mild hypertensive (ht) males matched for age and weight. li c:p and na-li ct were strongly correlated (r = -0.73), p less than 0.001), confirming the validity of li c:p as an in vivo index of na-li ct. no differences in li c:p (nt: 0.27 +/- 0.07; ht: 0.23 ...19901708027
tonic suppression of baroreceptor reflex by endogenous neurotensin in the rat.we evaluated the modulatory role of endogenous neurotensin (nt) in baroreceptor reflex (brr) response in sprague-dawley rats anesthetized with pentobarbital sodium. intracerebroventricular (i.c.v.) administration of nt (15 or 30 nmol) significantly reduced the sensitivity of the brr response. blocking the endogenous activity of the tridecapeptide with its specific antagonist, (d-trp11)-nt (4 or 8 nmol) or antiserum against nt (1:20); or inhibiting the aminopeptidases with bestatin (200 nmol), on ...19902326505
changes in alpha 2-adrenoceptors on vascular smooth muscle and neural membranes following hypertension induced by renal ischemia.alpha 2-adrenoceptors were characterized on neural and vascular membranes from 2-kidney-1-clip renal hypertensive (rht) and normotensive (nt) rats. rats were sacrificed 6 weeks after induction of renal ischemia, and the specific binding of 3h-clonidine to smooth muscle membranes form tail arteries and neural membranes from various brain regions was examined. additionally, isometric contractions of helically cut tail artery strips produced by various alpha-adrenoceptor agonists were measured. sca ...19911685246
characterization of neurotensin(6-13) from an hepatic fibrolamellar carcinoma.neurotensin(6-13) has been isolated and sequenced as the major form of neurotensin-like immunoreactivity (ntli) in a human hepatic fibrolamellar carcinoma. circulating ntli in the patient, especially c-terminal, was very high. in additional studies, nt(6-13) was synthesized and compared with the purified tumor ntli by hplc analysis and by testing stability in plasma in vitro. these methods confirmed that the tumor ntli was identical to nt(6-13). since the metabolic clearance rate of synthetic nt ...19911664950
characterization of neurotensin binding sites on rat mesencephalic cells in primary culture.many studies have reported the presence of high amounts of neurotensin (nt) binding sites in the mesencephalon of adult rat, and their possible role in mediating the effects of the peptide on the activity of mesencephalic dopaminergic neurons. in the present study, we demonstrate the presence of nt sites in primary cultures of embryonic rat mesencephalic cells. on these cells, a single class of high affinity 125i-nt binding sites was observed. the value of the apparent affinity constant (0.3 nm) ...19911661213
ion permeability of ciliary membrane vesicles isolated from tetrahymena. single-channel recording study on the membrane reconstituted into a planar lipid bilayer.an ion channel in ciliary membrane vesicles isolated from tetrahymena pyriformis nt-1 was characterized with a single-channel recording technique applied to the membrane reconstituted into a planar lipid bilayer made of soybean phospholipid. the gating of this channel is independent of membrane potential and it spends most of the time in its open-channel state. it is selective for metal cations over gluconate anion although it little distinguishes cations, ca2+, ba2+, mg2+, and k+. this channel ...19862437103
detection of stable secondary structure at the 3' terminus of dengue virus type 2 rna.the 3'-terminal sequences of flavivirus genomes within approx. 100 nucleotides (nt) have been suggested to have a highly conserved secondary structure, as based on the known nt sequence data and free-energy calculations using computer programs. to test the existence of a secondary structure in solution, we devised a strategy to generate truncated rna molecules from about 0.3-1.4 kb in length, having the same polarity and nt sequence as dengue virus type 2 (den-2) rna (new guinea-c strain). when ...19911660836
neurotensin may function as a regulatory peptide in small cell lung cancer.neurotensin (nt) has been postulated to act as a modulatory agent in the central nervous system. besides its presence in mammalian brain, nt is produced by small cell carcinoma of the lung (sclc) and cell lines derived from these tumors. receptors have also been characterized in some sclc cell lines leading to the suggestion that nt could regulate the growth of sclc in an autocrine fashion similar to bombesin/grp. previously, we had reported that a 10 nm dose of nt and nt(8-13), but not nt(1-8), ...19911646999
novel promoter and splice junction defects add to the genetic, clinical or geographic heterogeneity of beta-thalassaemia in the portuguese population.in order to delineate the spectrum and the relative abundance of beta-globin gene defects causing thalassaemia in the portuguese population, a representative sample was analysed including 51 beta-thalassaemia carriers along with 26 patients representing different clinical phenotypes. seven mutations were identified, four of which [codon 39 (c----t), 39%; intervening sequence (ivs) 1 nucleotide (nt) 1 (g----a), 26%; ivs 1 nt 110 (g----a), 17%; ivs 1 nt 6 (t----c), 15%] account for 97% of 93 beta- ...19921634236
the effect of the beta thalassemia mutation on the clinical severity of the sickle beta thalassemia syndrome.in this study, we have defined the beta thalassemia mutation and characterized the beta globin haplotype and the alpha globin gene arrangement in a group of patients of sicilian descent with beta (s)/beta thalassemia. we found that those patients carrying a beta(+) thalassemia mutation associated with a moderate reduction of beta chain synthesis (beta(+) ivs-1 nt 6) have normal or reduced hb levels and mild to moderate clinical manifestations, as defined by the number of hospital admission and s ...19892507407
effect of neurotensin on contractile activity and [3h]acetylcholine release in cat terminal ileum during different postnatal periods.the effect of neurotensin (nt) on the contractile activity of circular and longitudinal strips from the terminal ileum of 15-, 30-, 60-day-old and adult cats as well as on the resting and electrically-evoked release of [3h]acetylcholine (ach) was studied. radioactivity was measured by liquid scintillation spectrometry and the effect of nt was evaluated by the s2/s1 ratio. in the circular muscle strips nt (1-100 nm) inhibited spontaneous contractions in all age groups. in the longitudinal strips ...19921602843
a nuclear factor induced by hypoxia via de novo protein synthesis binds to the human erythropoietin gene enhancer at a site required for transcriptional activation.we have identified a 50-nucleotide enhancer from the human erythropoietin gene 3'-flanking sequence which can mediate a sevenfold transcriptional induction in response to hypoxia when cloned 3' to a simian virus 40 promoter-chloramphenicol acetyltransferase reporter gene and transiently expressed in hep3b cells. nucleotides (nt) 1 to 33 of this sequence mediate sevenfold induction of reporter gene expression when present in two tandem copies compared with threefold induction when present in a si ...19921448077
striking effects of coupling mutations in the acceptor stem on recognition of trnas by escherichia coli met-trna synthetase and met-trna transformylase.we measured kinetic parameters in vitro and directly analyzed aminoacylation and formylation levels in vivo to study recognition of escherichia coli initiator trna mutants by e. coli met-trna synthetase and met-trna transformylase. we show that, in addition to the anticodon sequence, mutations in the "discriminator" base a73 also affect aminoacylation. an a73----u change has a small effect, but a change to g73 or c73 significantly lowers vmax/kappm for in vitro aminoacylation and leads to apprec ...19921409632
branching patterns in the porcine coronary arterial tree. estimation of flow heterogeneity.the aim of this study is to quantify the porcine coronary arterial branching pattern and to use this quantification for the interpretation of flow heterogeneity. two casts of the coronary arterial tree were made at diastolic arrest and maximal dilation. the relation between length and diameter of arterial segments was quantified, as well as the area expansion ratio and diameter symmetry of vascular nodes. these relations were used to construct computer models of the coronary arterial tree, cover ...19921394880
alpha alpha alpha alpha anti-3.7 type ii: a new alpha-globin gene rearrangement suggesting that the alpha-globin gene duplication could be caused by intrachromosomal recombination.we report here a new human alpha-globin gene rearrangement carrying the two normal, alpha 2 and alpha 1, and two hybrid, alpha 1/alpha 2, globin genes in the order 5'-alpha 2-alpha 1/alpha 2-alpha 1/alpha 2-alpha 1-3'. both the hybrid genes, subtyped with apai and rsai restriction enzymes, were found to be of the uncommon anti 3.7 type ii. the hybrid genes were expressed at the biosynthetic level and their interaction with the beta-thalassaemia ivs 1 nt 1 g----a mutation caused thalassaemia inte ...19921349564
two liver-enriched trans-acting factors support the tissue-specific basal transcription from the rat tyrosine aminotransferase promoter.the rat tyrosine aminotransferase gene (tat) is a glucocorticoid-inducible gene, specifically expressed in liver. using gel retardation assays, we have shown that its promoter (nt + 1 to -350; tat.35) binds a combination of both ubiquitous and liver-specific trans-acting factors. cis-acting sequences spanning: (i) nt -65 to -85 bound nf-y, an ubiquitous "aaccaat" box binding factor; (ii) nt -157 to -171 bound a liver-enriched member of the nf1 gene family [nf1liver (nf1l hereafter)]; (iii) nt -2 ...19921348627
genetic variation in vivo and proposed functional domains of the 5' noncoding region of poliovirus rna.poliovirus has a single-stranded rna genome of about 7,440 nucleotides (nt) with an unusually long 750-nt noncoding region in the 5' end (5'ncr). several regulatory functions have been assigned to the 5'ncr. we sequenced the 5'ncrs of 33 wild-type 3 poliovirus strains to study the range and distribution of naturally occurring sequence variations. in this regard, the 5'ncr can be divided into a conserved part (nt 1 to 650) and a hypervariable part (nt 651 to 750). in the conserved part, altogethe ...19921323698
the biological relevance of n-terminal neurotensin fragments in the regulation of exocrine pancreas secretion.stimulation of the exocrine pancreas is one of the biological effects attributed to the tridecapeptide neurotensin (nt). only the c-terminal 8-13 fragment with its extremely short plasma half-life in the peripheral circulation was considered to be necessary for biological activity. the n-terminal fragments that are detectable in peripheral blood in much greater concentrations were considered to be of no importance. in order to elucidate the biological relevance of these n-terminal fragments, fiv ...19892717600
genomic typing of hepatitis c viruses present in china.hepatitis c virus (hcv) genomic clones were obtained from the serum of chinese hcv carriers using a polymerase chain reaction-based approach. consensus sequences were derived from (1) the structural region (nt 1-1543) for one carrier, (2) the hypervariable region v (nt 1156-1233) from four carriers and (3) region v3 from four carriers. region v3, located in the nonstructural domain ns5 (nt 7066-7137), has been previously shown to be a particularly good marker for the genomic typing of hcv isolat ...19921318245
neurotensin and neuromedin n stimulate mucin output from human goblet cells (cl.16e) via neurotensin receptors.the stably differentiated human intestinal goblet cell line cl.16e was used to study the effects of two structurally related regulatory peptides, neurotensin (nt) and neuromedin n (nn), on mucus secretion. nt and nn stimulated rapid release of mucins from filter-grown cl.16e cells, this effect being dose related with a mean effective dose of 36 nm for nt and 422 nm for nn. the order of potency of nt, three nt fragments corresponding to the nh2-terminal part [nt-(1-11)] or to the cooh-terminal pa ...19921312794
protection against herpes simplex virus infection in mice by recombinant murine interferon-beta in combination with antibody.a recombinant murine interferon -beta (rmuifn-beta) was used to suppress the development of skin lesions and death of mice after challenge with herpes simplex virus (hsv) type 1 (hsv-1). depilated female balb/c mice were inoculated intradermally with hsv-1, hayashida strain, and were administered various concentrations of interferon (ifn) intraperitoneally 3 h later. the treatment with ifn was given once a day for 10 successive days. under the conditions in which almost all control mice died aft ...19872821897
e1a inducibility of the adenoviral early e2a promoter is determined by specific combinations of sequence elements.by transient expression analysis in hela cells of adenovirus-2 e2a early (e2ae) promoter mutants and hybrid e2ae-beta-globin gene constructs, we demonstrate the existence of three nucleotide (nt) sequence elements involved in the e1a-responsiveness of the e2ae transcription unit: element i, localized within a segment (nt -13 to +62) surrounding the major e2ae cap site (nt + 1); element ii (between nt -71 and -29), and element iii (between nt -146 and -86). each element is unable by itself to con ...19872828188
high affinity binding of [3h]neurotensin of rat uterus.[3h]neurotensin (nt) was found to bind specifically and with high affinity to crude membranes prepared from rat uterus. scatchard analysis of saturation binding studies indicated that [3h]nt apparently binds to two sites (high affinity kd 0.5 nm; low affinity kd 9 nm) with the density of high affinity sites (41 fmoles/mg prot.) being about one-third that of the low affinity sites (100 fmoles/mg prot.). in competition studies, nt and various fragments inhibited [3h]nt binding with the following p ...19872831520
changes in membrane lipid composition during temperature adaptation by a thermotolerant strain of tetrahymena pyriformis.experiments on temperature adaptation have been conducted using a thermotolerant clone of tetrahymena pyriformis designated as strain nt-1. the strain was able to grow well at 39.5 and 15 degrees c and could adapt quickly when transferred from one of these temperatures to the other. cells grown at the extreme temperatures differed markedly in their membrane lipid composition, particularly in the phospholipid polar head groups and hydrocarbon chains. the levels of fatty acid unsaturation increase ...1976817746
tetrahymena strives to maintain the fluidity interrelationships of all its membranes constant. electron microscope evidence.when cells of tetrahymena pyriformis, strain nt-1, were chilled from their growth temperature of 39.5 degrees c to lower temperatures, the plasma membrane, outer alveolar, nuclear, outer mitochondrial, food vacuolar, and endoplasmic reticulum membranes each responded in a fashion quite characteristic of the membrane type. in most cases a distinctive rearrangement of intramembrane particles, as discerned by freeze-fracture electron microscopy, began abruptly at a definitive temperature. by compar ...1977402370
studies on tetrahymena membranes. palmitoyl-coenzyme a desaturase, a possible key enzyme for temperature adaptation in tetrahymena microsomes.(1) microsomes from a thermotolerant tetrahymena nt-1 catalyze the conversion of palmitoyl-coa to palmitoleate. (2) palmitoyl-coa desaturase enzyme requires molecular oxygen and nadh or nadph as cofactor and its activity is inhibited by cyanide. a ph optimum range 7.0--7.3 is observed. (3) there is a clear break at 30 degrees c and a slight bend around 15 degrees c in the arrhenius plots of palmitoyl-coa desaturase activity. (4) after quenching from 39.5 degrees c, at 26 degrees c microsomal mem ...197720149
purification and properties of a neurotensin-degrading endopeptidase from pig brain.neurotensin (nt) endopeptidase (ec 3.4.24.16) has been purified about 800-fold from pig brain by four sequential chromatographic steps depending on ion-exchange and hydrophobic interactions. two types of preparation were studied: one from a triton x-100-solubilized membrane fraction, and the other from the soluble fraction containing 90% or more of the total activity in the homogenate. nt endopeptidase activity was monitored by high-precision liquid chromatography of the two peptide products, ch ...19911905921
direct stimulation of enzyme secretion from rat exocrine pancreas by neurotensin and its naturally occurring fragments.neurotensin stimulates amylase release from dispersed pancreatic acini at concentrations as low as 10(-15) m. the naturally occurring fragments of neurotensin (nt), nt 1-8 and nt 1-11, also stimulate amylase secretion at concentrations that occur in peripheral plasma (10(-11) m). the analogue d-phe11 neurotensin was as potent as neurotensin itself with respect to stimulation of amylase secretion. basal plasma neurotensin levels were approximately 10 pmol/l, a concentration that stimulates the ex ...19872434384
survey of distribution of substance p, vasoactive intestinal polypeptide, cholecystokinin, neurotensin, met-enkephalin, bombesin and phi in the spinal cord of cat, dog, sloth and monkey.levels of substance p (sp), peptide-histidine-isoleucine (phi), vasoactive intestinal polypeptide (vip), cholecystokinin (cck), neurotensin (nt), bombesin (bom) and methionine-enkephalin (met-enk) like immunoreactivity were measured in cat, dog, primate and sloth cervical, thoracic, lumbar and sacral dorsal and ventral horns and dorsal root ganglia. the levels of peptides in the cat sacral cord and the principal peaks of immunoreactivity on a 10-60% acetonitrile gradient on a c18 reverse phase h ...19882453858
a comparison of the effects of mesencephalic injections of neurotensin(1-13) and neuromedin n on brain electrical self-stimulation.neuromedin n (nm-n), a hexapeptide that shares a four amino acid c-terminal homology with the tridecapeptide, neurotensin (nt), has been suggested as a potential neurotransmitter or neuromodulator that could interact with the nt-sensitive receptors. in this experiment, we compared the effects of an equimolar concentration of nm-n and nt(1-13) injected in the ventral tegmental area (vta) on brain electrical self-stimulation (ss), a behavior previously shown to be potentiated by vta injections of ...19921437713
beta-thalassaemia mutations and the underlying beta gene cluster haplotypes in the greek population.the polymorphic sites across the beta gene cluster (restriction haplotypes) in association with specific thalassaemic mutations were analyzed in representative samples of normal and thalassaemic greeks in comparison to similar data of other populations around the mediterranean basin. we studied 316 normal chromosomes, 218 chromosomes from patients with thalassaemia major and 72 chromosomes from patients with thalassaemia intermedia. in the former group, haplotype frequencies followed the order i ...19921299316
molecular characterization of beta-thalassemia mutations in egypt.the relative frequency of different beta-thalassemia mutations and their association with beta-globin haplotypes were studied in patients from the nile delta region, egypt, by means of the polymerase chain reaction, oligonucleotide hybridization and restriction analysis. we found that 8 mutations account for 77% of beta-thalassemia chromosomes in this population, the commonest being ivs-1 nt 110, ivs-1 nt 6 and ivs-1 nt 1. each mutation was associated with a specific haplotype, with the exceptio ...19901975554
[11c-methionine pet, imp-spect, ct and mri in brain tumors].11c-labelled l-methionine uptake was measured in 7 patients with brain tumours prior to surgery, and in 2 patients with infarction, using pet. the strongest uptake occurred in tumours with a high grade of malignancy (astrocytoma iv: tumour/non-tumour t/nt = 2.6) while low-grade tumours accumulated less activity (astrocytoma ii: t/nt = 1.4). conventional 99mtc dtpa scans revealed a damage of blood brain barrier (bbb) in 4 patients (2 infarctions) with no or only slight 11c-methionine accumulation ...19852992024
beta-thalassemia intermedia in turkey.dna data have been collected for 41 patients with beta-thalassemia intermedia without transfusion dependency. they belonged to 33 families, and 45 of their parents were included in the study. eight patients were homozygous for the frameshift at codon 8 (-aa), and nine were homozygous for the ivs-2 nt 1 (g----a) mutation; haplotypes iv and iii, respectively, were associated with these mutations. three patients had a g gamma a gamma(delta beta)0-thalassemia homozygosity, characterized by a deletio ...19902291577
escherichia coli-derived human interferon-gamma with cys-tyr-cys at the n-terminus is partially n alpha-acylated.purified preparations of recombinant human interferon-gamma (rifn-gamma) with cys-tyr-cys at the n-terminus ([ cys-tyr-cys]ifn-gamma) derived from escherichia coli gave two closely migrating bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) and two peaks on reversed-phase high-performance liquid chromatography (rphplc). in contrast, rifn-gamma without cys-tyr-cys and rifn-gamma in which both cys-1 and cys-3 were substituted with serine behaved as a single species on b ...19892493219
the spectrum of beta-thalassaemia in burma.the molecular defects causing beta-thalassaemia (beta-thal) have been analyzed in 63 unrelated burmese patients. the patients include 49 with hb e/beta-thal, 13 with beta-thal major and 1 with hb s/beta-thal. using synthetic oligonucleotide probes and aided by the polymerase chain reaction 64/76 (84%) of the alleles have been characterized. to date 6 mutations have been identified. the most common mutation is the splicing defect at ivs-1 nt 1 which accounts for 32% of the alleles. complete chara ...19892575755
involvement of dopamine in the central effect of neurotensin on intestinal motility in rats.the effects of intracerebroventricular (icv) administration of neurotensin (nt) before a meal on intestinal postprandial motility were examined in conscious rats chronically fitted with intraparietal nichrome electrodes in the duodeno-jejunum. the effects were compared with those of two analogues, [d-tyr11]nt and [d-trp11]nt, resistant to degradation by brain peptidases. nt (10 micrograms icv) delayed the occurrence of postprandial disruption of duodenal motility and blocked it on the jejunum. [ ...19902087439
the conserved dinucleotide ag of the 3' splice site may be recognized twice during in vitro splicing of mammalian mrna precursors.we have previously used site-directed mutagenesis to introduce an additional branch site into the first intron of the human beta-globin gene at nt -24 between the natural branch site (nt -37) and the normal 3' splice site (nt -1). we found that either the upstream or downstream branch site could be used during in vitro splicing, depending on which site best matched the mammalian branch site consensus yurac (r = purine; y = pyrimidine). here we show that introduction of an additional ag dinucleot ...19902401404
determination of beta-19-nortestosterone and its metabolite alpha-19-nortestosterone in biological samples at the sub parts per billion level by high-performance liquid chromatography with on-line immunoaffinity sample pretreatment.an immunoaffinity precolumn (immuno precolumn) packed with sepharose-immobilized polyclonal antibodies against the anabolic hormone 17 beta-19-nortestosterone (beta-19-nt) was used for the selective on-line pretreatment of raw extracts of urine, bile and tissue samples by high-performance liquid chromatography. using uv detection (247 nm), beta-19-nt and its metabolite 17 alpha-19-nortestosterone (alpha-19-nt) can be determined in biological samples with a detection limit of 0.05 microgram/kg. o ...19892745646
biological potency of neurotensin metabolites in vivo: importance of alcohol 'fixation' of blood.neurotensin (nt), a 13-amino acid peptide, is released from the ileum following a meal. it is metabolized principally by the kidney and in the circulation to n-terminal fragments and apparently rapidly degraded c-terminal fragments. the present study was designed to compare the biological activity (plasma pancreatic polypeptide response) and the clearance kinetics of nt(1-13), the n-terminal fragment nt(1-11) and the c-terminal fragment nt(8-13). to measure accurately the circulating concentrati ...19892491208
neurotensin-induced excitation of neurons of the rat's frontal cortex studied intracellularly in vitro.the actions of neurotensin (nt) on frontal pyramidal neurons were studied in vitro in slices of rat cerebral cortex using current clamp and single electrode voltage clamp (sevc) techniques. bath application of nt (0.1 microm-10 microm) induced a depolarization (2-13 mv) in 88% of the pyramidal cells, this effect was associated with a decrease in input conductance of 5-35% and its reversal potential was estimated at -88 +/ -9.7 mv. typically, this depolarizing effect of nt was transient, since no ...19892599044
effect of acute exercise on plasma neurotensin levels.neurotensin (nt) levels were examined in five aerobically untrained females aged 20-36 engaged in acute graded exercise testing. in addition to radioimmunoassay measurements, high pressure liquid chromatography was performed to further characterize plasma nt-like immunoreactivity (ntli). epinephrine (e), norepinephrine (ne), and lactate (l) responses were also determined. exercise testing consisted of one hour of treadmill running subdivided into three 20-minute segments representing 50, 60, and ...19892587418
properties of digitonin-solubilized calmodulin-dependent guanylate cyclase from the plasma membranes of tetrahymena pyriformis nt-1 cells.calmodulin-dependent guanylate cyclase from tetrahymena plasma membranes was solubilized in about a 22% yield by using digitonin in the presence of 0.2 mm cacl2 and 20% glycerol. the detergent, when present in the assay at concentrations above 0.05%, diminished the basal and calmodulin-stimulated activity of the enzyme. guanylate cyclase solubilized with digitonin was eluted from deae-cellulose with 200 mm kcl in a yield of 50%. properties of the solubilized enzyme were similar to those of the n ...19872880561
selective cleavage of human acth, beta-lipotropin, and the n-terminal glycopeptide at pairs of basic residues by ircm-serine protease 1. subcellular localization in small and large vesicles.we present a study of the cleavage specificity of ircm-serine protease 1 from frozen porcine pituitary neurointermediate lobes using polypeptide substrates representing different segments of human pro-opiomelanocortin. using 125i-labeled acth(11-24) and a 125i-labeled model beta-lipotropin (beta-lph) peptide, the preference of this protease for cleavage c-terminal to the pairs of basic residues lys-arg and lys-lys was clearly seen. this study was extended to larger unlabeled natural human polype ...19863015945
isolation and structural characterization of a diacyltaurolipid in cells of tetrahymena mimbres.a diacyltaurolipid was found in cells of tetrahymena mimbres (formerly tetrahymenas pyriformis nt-1). the lipid accounted for about 0.05% of the total lipids of the cells, and was composed of taurine (1 equiv.), 3,7,13-trihydroxystearic acid (1 equiv.) and non-hydroxy fatty acids (2 equiv.). by mild alkaline hydrolysis, non-hydroxy fatty acids (2 equiv.) and 2-(3,7,13-trihydroxyoctadecanoyl)aminoethanesulfonic acid were obtained. for determination of the positions of the ester bonds of the lipid ...19883132980
distribution of neurotensin receptors in the primate hippocampal region: a quantitative autoradiographic study in the monkey and the postmortem human brain.the distribution of [3h]neurotensin ([3h]nt) binding sites in the monkey and the postmortem human brain was studied by using quantitative in vitro receptor autoradiography. biochemical experiments carried out on tissue sections of the monkey hippocampus showed that the binding of [3h]nt was saturable, reversible and of high specificity. the hippocampal [3h]nt binding was displaced by fragment nt 8-13 but not fragment nt 1-8 of the peptide. the anatomical analysis showed a highly heterogeneous di ...19873035436
meal-stimulated neurotensin immunoreactivity in plasma following gastric surgery: characterisation with two region-specific antisera.plasma neurotensin (nt) response to a simple fatty meal, administered via an indwelling naso-gastric tube, has been assessed in two groups of subjects following gastric surgery without resection, and in healthy controls. two region-specific nt antisera were employed in the radioimmunoassay (ria) of plasma samples. the first, nt3, recognises only nt 1-13 in plasma extracts, while the second, gnt 21, recognises nt 1-13, nt 1-11 and nt 1-8 equally. in addition, plasma extracts were subjected to rev ...19862419192
beta-thalassemia mutations in the portuguese population.in this study we have carried out haplotype analysis on the beta-globin gene cluster and characterized the beta-thalassemia mutation by oligonucleotide hybridization in 14 patients with thalassemia major and 5 with sickle cell/beta-thalassemia originating from southern portugal. we found that three mutations, namely the beta(0)-39, beta(0) ivs-1 nt 1 and beta(+) ivs-1 nt 110 are prevalent accounting for 53%, 32% and 10% of the beta-thalassemia chromosomes respectively. in general each mutation w ...19883338791
the neurotensin analog xenopsin excites nigral dopamine neurons.the electrophysiological effects of neurotensin (nt), its analog xenopsin, and the fragment nt-(1-8) on the activity of dopaminergic neurons in rat substantia nigra slices were compared. xenopsin and nt produced a concentration-dependent increase in the firing rate. the mean firing rate was increased by 58.5% with xenopsin (0.1 microm) and 49.1% with nt (0.1 microm). nt-(1-8) was inactive at this concentration. dopamine (100 microm) inhibited firing in these neurons by 54.7%. these data provide ...19883350051
detection of a new hybrid alpha 2 globin gene among american blacks.we have examined the alpha globin gene complex for 49 individuals with alpha-thalassemia-2 (-alpha 3.7). crossovers resulting in alpha-thalassemia-2 (type i) were observed in all 57 chromosomes with the -alpha 3.7 defect. except for one alpha-thalassemia-2 chromosome, all were linked to the absence of an rsa i restriction site located 0.7 kb 5' to the alpha 2-globin gene; this polymorphic site was observed for 10 of 38 non-alpha-thalassemia chromosomes from black americans. in four black familie ...19882896623
species-specific effects of neurotensin on gallbladder contraction in vitro.we have previously shown that an in vivo administration of neurotensin (nt) stimulates contraction of dog gallbladder (gb), but produces dilatation of gb in humans. the objective of this study was to examine the effect of nt on human, dog, guinea pig, and rabbit gb in vitro, in order to delineate direct versus indirect actions of nt in different species and to evaluate the structure-activity relationships of nt. the effect of nt on the canine sphincter of oddi (sod) was also examined in vitro. i ...19892910678
correlation between ventilatory threshold and endurance capability in marathon runners.the purpose of the study was to develop an index of endurance capability [i.e., "the ability to sustain a high fractional utilization of maximal oxygen uptake (vo2max) for a prolonged period of time"]. the index was based on the linear reduction of fractional utilization of vo2max with total running time greater than 7 min plotted on a log scale. the endurance index estimated from vo2max, running efficiency and the marathon performance of 18 male runners (30 +/- 7 yr old; vo2max = 66 +/- 5 ml.kg ...19873431378
variable abundance of a mitochondrial dna fragment in cultured tobacco cells.the relative abundance of a cloned 4.5 kilobase (kb) pair mitochondrial dna sequence in two suspension cultures of tobacco (nicotiana tabacum cv turkish samsun and nicotiana tabacum nt-1) has been examined. this sequence is 70-fold reduced in nt-1 relative to turkish samsun; the reduction is correlated with an increase in supercoiled mitochondrial dna. this sequence does not hybridize with mitochondrial dna from watermelon, maize, or saccharomyces cerevisiae, nor with several cloned mitochondria ...19873449225
neurotensin elevates cytosolic calcium in small cell lung cancer cells.the ability of neurotensin (nt) to elevate cytosolic ca2+ in small cell lung cancer (sclc) cells was investigated using the fluorescent ca2+ indicator fura 2-am. using sclc cell line nci-h345, nt elevated cytosolic ca2+ levels in a concentration-dependent manner. using a 10 nm dose, nt and c-terminal fragments such as nt(8-13) but not n-terminal fragments such as nt(1-8) elevated the cytosolic ca2+ levels. because egta (5 mm) did not affect the nt response, nt may cause release of ca2+ from intr ...19892560176
characterization of n-terminal fragment of proopiomelanocortin in cerebrospinal fluid.the molecular forms of the n-terminal fragment (hnt) of proopiomelanocortin were studied in cerebrospinal fluid (csf) from normal subjects, methadone-addicted patients, patients with hydrocephalus, and a patient with nelson's syndrome. the peptides were characterized by molecular sieving and concanavalin a-sepharose chromatography. immunoreactivity was detected using antibodies directed against the n- and c-terminal portions of the hnt (hnt and gamma 3msh antibodies, respectively). the mean immu ...19873584397
behavioral effects of neurotensin applied to periventricular structures of rats.neurotensin (nt), an active neuropeptide, and bicuculline, a gaba-a receptor antagonist, were microinjected into the rat medial hypothalamus (mh) or the dorsal periaqueductal gray matter (dpag). bicuculline (80 pmol) produced behavioral activation which included jumping and nt (1-20 nmol) caused a dose-dependent behavioral activation accompanied by catalepsy rather than jumping. these results suggest that the behavioral activation produced by nt may be due to an interaction of the neuropeptide w ...19892620181
construction of an agrobacterium tumefaciens c58 reca mutant.clones encoding the reca gene of agrobacterium tumefaciens c58 were isolated from a cosmid bank by complementation of an escherichia coli reca mutation. subcloning and mutagenesis with the lacz fusion transposon tn3hoho1 located the agrobacterium reca gene to a 1.3-kilobase segment of dna. beta-galactosidase expression from the fusions established the direction in which the gene was transcribed. the gene restored homologous recombination as well as dna repair functions in e. coli reca mutants. s ...19892676971
a comparison of the rheologic properties of neonatal and adult blood.a number of studies have indicated that the rheologic properties of neonatal blood are different from those of the adult. the frequent administration of blood components to the neonate during intensive care make it important that these differences be established and their causes understood. the purpose of this study was to make a detailed comparison of the rheologic properties of neonatal and adult blood, with particular emphasis on low shear rate viscosity and rouleaux-related phenomena. the vi ...19892717261
effects of icv administration of neurotensin and analogs on eeg in rats.the electroencephalographic (eeg) effects of the icv administration of neurotensin (nt 1-13), nt 1-8 (an inactive neurotensin fragment) and d tyr-11 nt (a long-lasting analog of neurotensin) were studied in rats. in awake rats, nt 1-13 (30 micrograms) and d tyr-11 nt (10 micrograms) induced an increase of the power spectrum in the theta range activity (4-7 hz). in rats recorded during the sleep-wakefulness cycles, nt 1-13 (10 and 30 micrograms) and d tyr-11 nt (10 micrograms) had an awakening ef ...19892748429
dissimilar effects of l and d amino acids on the growth of tetrahymena.of the l and d configurations of four amino acids (phenylalanine, valine, tryptophan, tyrosine) tested for influence on the growth rate of tetrahymena, only l-tyrosine was able to induce imprinting in tetrahymena pyriformis zeuthen. d-valine stimulated the division of t. pyriformis nt-1, but failed to induce imprinting. the experiments have substantiated the selectivity of the amino acid receptors of t. pyriformis, and the extraordinary imprinting potential of tyrosine as well, as judged by its ...19872833952
a library of trimethylguanosine-capped small rnas in physarum polycephalum.we have constructed a cdna library for the trimethylguanosine-capped small rnas (srnas) in the acellular slime mold physarum polycephalum. capped srnas were purified from total cellular rna of vegetative microplasmodia by preparative immunoprecipitation with anti-trimethylguanosine antibody. the purified rna was analyzed by polyacrylamide gel electrophoresis. approx. eleven different capped srnas were observed with a size range of 70-204 nucleotides (nt). based on their approximate sizes, the pr ...19872956157
in vivo inactivation of neurotensin in dog ileum: major involvement of endopeptidase 24-11.the metabolism of tritiated neurotensin (nt) after close i.a. perfusion in ileal segments of anesthetized dog was studied. venous effluents containing labeled metabolites and intact nt were collected and analyzed by high-performance liquid chromatography. the apparent half-life of the peptide was between 2 and 6 min. the tritiated metabolites of nt were identified as free tyrosine, nt-(1-7), nt-(1-8), nt-(1-10), nt-(11-13) and nt-(1-11). pretreatment of dog ileum with thiorphan or captopril indi ...19882855236
neurotensin metabolism in the rat: contribution of the kidney.the kidney plays a key role in the metabolism of neurotensin (nt). we have examined the renal mechanisms of nt clearance by measuring plasma nt basally and after 45 min infusion of nt(1-13) in intact rats, anephric rats (no glomerular filtration, no peritubular metabolism) and ureteral ligated rats (reduced filtration). plasma nt was measured by radioimmunoassay with both c (biologically active end) and n terminal directed antisera. in anephric and ureteral ligated rats, basal plasma nt like imm ...19873126491
[acute toxicity test on dermal application of nt-1 tape and 10% nitroglycerin (nt-1 ointment)].an acute toxicity of nt-1 tape was investigated in mice, rats and rabbits, and also an acute toxicity of nt-1 ointment in rabbits. an irritation of nt-1 tape was investigated in rabbits. dead animals treated with nt-1 tape or ointment were not observed in reliable maximum administration dose of 0.88 mg/body as gtn (nitroglycerin) in mice (male; about 29.1 mg/kg, female; about 35.2 mg/kg), of 3.96 mg/body as gtn in rats (male; about 26.0 mg/kg, female; about 28.9 mg/kg) and of 480 mg/kg as gtn in ...19863093689
intracellular phospholipase activities of tetrahymena pyriformis.phospholipase activity was studied in the protozoan tetrahymena pyriformis nt-1 by using exogenous phosphatidylethanolamine and phosphatidylcholine. several phospholipase activities were found in tetrahymena homogenates. they were distinguished with respect to ph optimum, activity dependence on ca2+, substrate specificity and positional specificity. ca2+-dependent phospholipase activity had an optimal ph around 9 and gave rise to free fatty acid and lysophospholipid. this enzyme hydrolyzes phosp ...19853928611
[percutaneous chronic toxicity study of 10% nitroglycerin (nt-1 ointment) in rabbits].a chronic toxicity test of 10% nitroglycerin (nt-1 ointment) was carried out in male nzw rabbits. nt-1 ointment was applied to the back skin for 26 weeks at daily doses of 15, 60 and 240 mg/kg as nitroglycerin itself, and 5-week withdrawal period was followed. topical dermal responses to nt-1: macroscopically, erythema, edema, scales, papules and dermal thickening were observed in response to nt-1 ointment. in the withdrawal period, however, all of them disappeared. histopathologically, thickeni ...19863093691
mapping the 5' ends, 3' ends, and splice sites of mrnas from the early e3 transcription unit of adenovirus 5.using nuclease gel analyses, the sites in the approximately 4000 nucleotide (nt) e3 transcription unit of adenovirus 5 (ad5) that encode the 5' ends, 3' ends, and 5' and 3' splice sites of the approximately 10 e3 mrnas were determined. transcription initiation of all mrnas occurs at two major (nt 1 and 8) and approximately two minor sites, situated 20-30 nt 3' to a tata box. there are two major 3' end sites (nt 2227 and 3308), located approximately 20 nt downstream from attaaa and an aataaa sequ ...19853966299
eight base pairs encompassing the transcriptional start point are the major determinant for baculovirus polyhedrin gene expression.the effects of mutations within the 92-bp region immediately upstream from the translational initiation atg of the polyhedrin gene of the baculovirus autographa californica nuclear polyhedrosis virus (acmnpv) were determined by plasmid transient expression assays in the presence of wild-type (wt) acmnpv dna. clustered point mutations were generated by substitution of 10-bp stretches of the polyhedrin promoter/leader region with a 10-bp hindiii linker. three of these linker scan (ls) mutations in ...19883071492
nutritional support team vs nonteam management of enteral nutritional support in a veterans administration medical center teaching hospital.one hundred one patients receiving enteral nutritional support (ens) by tube feeding during a 5-month period were prospectively studied. fifty patients were managed by a nutritional support team (t) and 51 patients were managed by the nonteam approach (nt). demographics, primary diagnosis, chronic diseases, medical service, calculated basal energy expenditure (bee), duration of ens, and final patient disposition were recorded. enteral formula, formula modifications, results of laboratory tests a ...19863099009
effects of intraventricular neurotensin on blood pressure and heat balance in rats.the effects of intraventricular neurotensin (nt) at doses of 0.1, 1.0, and 10.0 micrograms on blood pressure (bp), heart rate (hr), heat production (m), heat loss (h), and colonic temperature (t co1) were investigated in conscious rats in a direct calorimeter at 18 and 28 degrees c. at 18 degrees c, a 10.0 micrograms of nt significantly increased bp for several minutes after injection with prolonged bradycardia. the larger two doses (1.0 and 10.0 micrograms) significantly reduced m and t co1. in ...19854046236
[teratological test of 10% nitroglycerin (nt-1 ointment) in rabbits].a teratological test of 10% nitroglycerin (nt-1 ointment) was carried out in new zealand white rabbits. pregnant rabbits were treated percutaneously with nt-1 ointment from day 6 to 18 of gestation at dose levels of 15, 60 and 240 mg/kg/day as nitroglycerin itself. all pregnant rabbits were killed on day 29 of gestation, and the influences of nt-1 ointment upon the performances of dams and fetuses were examined. during the treatment period, erythema was observed on the treated dorsal skin in all ...19863093692
[percutaneous subacute toxicity study of 10% nitroglycerin (nt-1 ointment) in rabbits].nt-1 ointment is a compound containing 10% nitroglycerin which is topically applied to the skin for angina pectoris. the subacute toxicity of this compound was examined by the continuous application for 5 weeks to the shaven skin of rabbit back at dose levels of 240, 120 and 60 mg/kg, and the recovery was examined 3 weeks after withdrawal of the drug. no special skin response to the nt-1 ointment was observed other than an erythema of the grading 2-3 draize points, while the control ointment, wh ...19863093690
a possible cyclic amp-mediated regulation of microsomal fatty acyl-coa desaturation system in tetrahymena microsomes.profound alterations in the microsomal fatty acyl-coa desaturase activities and cyclic amp production of a unicellular eukaryote, tetrahymena pyriformis nt-1, originally grown in the glucose-deficient medium, were observed, following the administration of glucose or beta-adrenergic agonists such as epinephrine and isoproterenol. there was a great increase of stearoyl-coa (delta 8) desaturase activity coincident with a 2-fold decrease of oleoyl-coa (delta 12) desaturase activity over the first 2 ...19852861855
the dynamics of arachidonic acid liberation and prolactin release: a comparison of thyrotropin-releasing hormone, angiotensin ii, and neurotensin stimulation in perifused rat anterior pituitary cells.the dynamics of arachidonic acid (aa) liberation and prl release were highly correlated in perifused rat anterior pituitary cells during stimulation by three different neuropeptides: trh, angiotensin ii (aii), and neurotensin (nt). after preincubation of these cells with 1 microci [3h]aa, a 20-min perifusion with aii (100 nm), trh (100 nm), or nt (1 microm) elicited a sharp initial increase in prl release and [3h]aa efflux, which rapidly subsided (within 6 min) to less elevated levels of prl rel ...19883139397
properties of acid phospholipases in lysosome and extracellular medium of tetrahymena pyriformis.phospholipase activity in the lysosomes of the protozoan tetrahymena pyriformis strain nt-1 was studied using phospholipids radioactively labeled in the fatty acid moieties. lysosomal homogenates showed high phospholipase activity with an acidic ph optimum. unlike the phospholipases in rat liver lysosomes, almost all activity was recovered from the membranous fraction of the lysosomes. the activity was partially solubilized by treatment of the membranes with a detergent or trypsin. using specifi ...19863082863
a family of non-allelic trna(valguu) genes from the cellular slime mold dictyostelium discoideum.a haploid genome of the cellular slime mold dictyostelium discoideum contains at least 14 non-allelic gene copies coding for a trna(valguu). the structure, genomic organization, and expression of these genes have been analyzed in relation to stages of the developmental cycle. so far, 13 trna(valguu) genes have been isolated and characterized. all genes contain identical mature trna-coding regions, and consequently identical gene internal promoter elements. however, different genes differ with re ...19883072263
pharmacokinetics and metabolism of neurotensin in man.we studied the pharmacokinetics, arteriovenous extraction, and degradation sites of neurotensin (nt) in man during iv infusions of synthetic intact nt [nt-(1-13)] and the nh2-terminal metabolite nt-(1-8) during lipid ingestion and by catheterization of various vascular beds in normal subjects and patients with hepatic disease. nt-like immunoreactivities in plasma were quantitated using 2 sequence-specific rias and gel filtration chromatography. during iv infusion of nt-(1-13) in 6 normal subject ...19892918048
extraction of neurotensin-like immunoreactivities from porcine ileal mucosa.the extractability of neurotensin (nt) from porcine ileal mucosa was studied by comparison of eight extraction procedures. tissue content of neurotensin-like immunoreactivity was quantitated and characterized by sequence-specific radioimmunoassays and gel filtration chromatography. homogenization prior to boiling in extraction solvent produced higher levels of the intact peptide than the reverse procedure. n-terminal immunoreactivity was not influenced by the sequence of these steps. tissue leve ...19873628080
release of histamine and adrenaline in vivo following intravenous administration of neurotensin.plasma histamine levels of rats anesthetized with pentobarbital sodium were significantly increased by intravenous administration of neurotensin (nt, 1 nmole/kg) with the maximum effect at 3 min, and a return to the initial levels in 20 min. treatment of animals with compound 48/80 or disodium cromoglycate completely inhibited the elevation of histamine level by nt, however, treatment with reserpine or diphenhydramine and adrenalectomy did not affect the elevation. plasma adrenaline levels incre ...19836405112
effect of neurotensin and neurotensin fragments on gastric acid secretion in man.the effect of intravenous infusion of neurotensin (nt) and nt-fragments on pentagastrin stimulated gastric acid secretion was investigated in healthy subjects. neurotensin was infused in three doses (72, 144 and 288 pmol/kg per h). an n-terminal fragment (nt 1-8), a c-terminal fragment (nt 8-13) and an nt-analogue, substituted at the c-terminal tyrosine residue (phe11-nt) were infused in two doses (72 and 144 pmol/kg per h). concentrations of the infused peptides were measured in peripheral veno ...19863763961
comparison of the immunochemical responses by anti-nadph-cytochrome c reductase of tetrahymena pyriformis (strain nt-1) in protozoan cells and mammalian liver microsomes.comparison of the microsomal nadph-cytochrome c reductase activities in the four tetrahymena cells (pyriformis, strain gl and nt-1; thermophilia; iso) and rat liver was studied. the reductase activity in strain nt-1 was lowest among four tetrahymena cells grown at 24 degrees c. rabbit antibody was prepared against the purified nadph-cytochrome c reductase from tetrahymena pyriformis (strain nt-1) microsomes. microsomal nadph-cytochrome c reductase activities in various tetrahymena cells were inh ...19853922671
enhancement of phagocytosis by neurotensin, a newly found biological activity of the neuropeptide.specific binding of neurotensin (nt) to mouse peritoneal thioglycollate-elicited macrophages and macrophages differentiated in vitro from bone marrow cells was demonstrated and characterized. nt binding to these phagocytes modulated their phagocytic capacity in a biphasic manner. at concentrations of 10(-14) to 10(-9) m nt, a dose-dependent augmentation of phagocytosis (up to 2-fold) was observed. further increases in the concentration of nt resulted in a gradual decrease of the augmented respon ...19826186124
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