| a sex comparison of serotonin immunoreactivity and content in the ferret preoptic area/anterior hypothalamus. | previous studies with rats raised the possibility that sexually dimorphic features of the medial preoptic area/anterior hypothalamus (poa/ah) may result, in part, from a sex difference in the serotonergic innervation of this region. we asked whether a similar phenomenon may occur in a carnivore, the ferret. a sexually dimorphic male nucleus of the dorsal poa/ah (mn-poa/ah) has previously been characterized in nissl-stained sections of the male ferret forebrain; this nucleus is absent in females. ... | 1993 | 8348343 |
| sequential differentiation of sensory innervation in the mystacial pad of the ferret. | the mystacial pad of the ferret has an elaborate sensory innervation provided by three types of terminal nerves that arise from the infraorbital branch of the trigeminal nerve. deep and superficial vibrissal nerves innervate nearly exclusive targets in the large follicle-sinus complexes (f-scs) at the base of each tactile vibrissa. dermal plexus nerves innervate the fur between the vibrissae. each type of nerve provides a similar variety of sensory endings, albeit to different targets. in this s ... | 1993 | 8349846 |
| peptide yy: a neuropeptide in the gut. immunocytochemical and immunochemical evidence. | peptide yy immunoreactivity was detected in neuronal elements in the upper digestive tract of the rat, cat, ferret and pig by immunocytochemistry and radioimmunoassay combined with high-performance liquid chromatography. the two peptide yy antisera used do not recognize the related peptides neuropeptide y and pancreatic polypeptide. in the rat peptide yy-immunoreactive nerve fibres were virtually restricted to the stomach smooth muscle of the minor curvature where they were numerous. peptide yy- ... | 1993 | 8350990 |
| early clinical trial of mdl 73.147 ef: a new 5-ht3-receptors antagonist for the prevention of chemotherapy-induced nausea and vomiting. | like mdl 72.222, one of the first selective 5-hydroxytryptamine3 (5-ht3) receptors antagonist discovered, mdl 73.147 ef has been shown to possess antiemetic properties in the ferret model. we conducted a phase i study with mdl 73.147 ef in 31 patients, treated with emetogenic drugs over one to five days (cisplatin, cyclophosphamide, doxorubicin, dacarbazine). | 1993 | 8353090 |
| rs 42358-197, a novel and potent 5-ht3 receptor antagonist, in vitro and in vivo. | the pharmacological activity of rs 42358-197, a novel 5-ht3 receptor antagonist has been evaluated in vitro and in vivo. in functional experiments in vitro, rs 42358-197 behaved as a competitive antagonist against 5-ht-induced contractions in the guinea pig ileum (low-potency phase), yielding a pa2 estimate of 8.1. rs 42358-197 was devoid of any agonistic or antagonistic activity at 5-ht1-like receptors (contraction of canine saphenous vein), 5-ht2 receptors (contraction of rabbit aorta) or 5-ht ... | 1993 | 8355189 |
| influence of host cell-mediated variation on the international surveillance of influenza a (h3n2) viruses. | growth of clinical specimens of influenza viruses in eggs can result in the selection of antigenic variants distinct from corresponding viruses grown in mammalian tissue culture. to evaluate the contribution of host cell selection on the antigenic diversity of human influenza isolates, as seen in annual surveillance studies, viruses grown in embryonated eggs were compared by antigenic and genetic analyses with their mammalian tissue culture-grown counterparts. clinical specimens were gathered fr ... | 1993 | 8356790 |
| the effects of indomethacin and thiorphan on bradykinin-induced albumin output and submucosal gland secretion in the ferret trachea in vivo. | in the ferret liquid-filled trachea in vivo, intraluminal bradykinin (bk, 3-300 microm) produced concentration-dependent increases in the output of lysozyme from submucosal gland serous cells and albumin movement into the lumen. baseline outputs of albumin and lysozyme were not altered significantly by intraluminal indomethacin (10 microm) or thiorphan (10 microm). however, intraluminal indomethacin completely blocked the bk-induced increase in albumin output. intraluminal thiorphan (10 microm) ... | 1993 | 8358181 |
| differential effects of cocaine and cocaethylene on intracellular ca2+ and myocardial contraction in cardiac myocytes. | 1. isolated cardiac myocytes of the ferret were used to investigate the influence of cocaine and cocaethylene on the intracellular ca2+ transient indicated by the indo-1 405/480 nm ratio signal, and peak cell shortening. 2. both cocaine and cocaethylene produced significant decreases in peak intracellular ca2+ and peak cell shortening in a dose-dependent manner. of interest, (1) the minimally effective dose of cocaethylene was ten fold lower (10(-8)m versus 10(-7)m) than that of cocaine; (2) the ... | 1993 | 8358533 |
| cellular mechanism of the positive inotropic effect of hydralazine in mammalian myocardium. | 1. the purpose of this study was to elucidate the cellular mechanism of the positive inotropic effect of hydralazine, a vasodilator widely used for afterload reduction in patients with heart failure that has also been reported to have positive inotropic effects on the heart. after isolation, right ventricular papillary muscles from the ferret were maintained in bicarbonate-buffered salt solution (30 degrees c). a concentration-response relationship was obtained for hydralazine (10(-6) to 10(-3) ... | 1993 | 8358564 |
| the reinnervation of healing extraction sockets in the ferret. | the objective of this study was to describe the pattern of healing of pulpal and periodontal nerve fibers following tooth extraction. the mandibular canine teeth were, under general anesthesia, removed from one side of nine young ferrets. one week (two animals), one month (four animals), and three months (three animals) later, again under general anesthesia, the animals were perfused with fixative. the mandibles were decalcified, paraffin-embedded, and serially sectioned. sample sections were st ... | 1993 | 8360365 |
| gastric anti-secretory, mucosal protective, anti-pepsin and anti-helicobacter properties of ranitidine bismuth citrate. | ranitidine bismuth citrate is a novel compound formed from ranitidine and a bismuth citrate complex. in conscious dogs, ranitidine bismuth citrate had similar activity to ranitidine hydrochloride as an inhibitor of histamine-induced gastric acid secretion when oral doses containing equivalent amounts of ranitidine base (0.1 or 0.3 mg/kg) were compared. in the rat, ranitidine bismuth citrate (3-30 mg/kg p.o.) prevented gastric mucosal damage induced by ethanol (fundic damage) and indomethacin (an ... | 1993 | 8364129 |
| osmolality affects ion and water fluxes and secretion in the ferret trachea. | nonisosmolar solutions were placed in the lumen of the ferret trachea in vitro in an organ bath. hyposmolar (150 mmol/kg) solutions progressively increased in osmolarity over 1 h. increases in luminal concentration of impermeant blue dextran occurred only after 5 min, suggesting that the initial changes were due to ion rather than water fluxes. with hyperosmolar solutions the osmolarity decreased over 1 h with no change in blue dextran concentration, indicating that ion but not water fluxes were ... | 1993 | 8365982 |
| role of nitric oxide and vasoactive intestinal polypeptide in vagally mediated relaxation of the gastric corpus in the anaesthetized ferret. | the roles of vip and no in vagally mediated relaxations of the gastric corpus were investigated in the anaesthetized ferret. intracorpus pressure was recorded manometrically during electrical stimulation of the cervical vagus nerve in three groups of animals: one control group (n = 6), one group treated with an inhibitor of no synthesis (ng-nitro-l-arginine methyl ester (l-name), 1.6 mg/kg); and a third group which had been immunized, prior to the experiment, with a vip-thyroglobulin conjugate ( ... | 1993 | 8366253 |
| resistance to health: when the mind interferes with the desire to become well. | secondary gain has long been viewed as a variable that can significantly affect a patient's recovery from such conditions as chronic pain disorders, factitious and somatoform disorders, and other psychological disorders. secondary gain has not been evaluated in terms of its impact on major illnesses such as cancer or autoimmune disorders. in this paper i discuss how secondary gain can be present in such illnesses and how it results in a resistance to health. this resistance to health can lead no ... | 1993 | 8368196 |
| pkc-mediated redistribution of mitogen-activated protein kinase during smooth muscle cell activation. | protein kinase c (pkc) translocates from the cytosol to the surface membrane at the time it mediates agonist-induced contraction of ferret vascular smooth muscle cells (r. a. khalil and k. g. morgan. j. physiol. lond. 455: 585-599, 1992). however, no direct communication between membrane-associated pkc and the contractile filaments has been identified. mitogen-activated protein (map) kinase is a substrate for pkc and is also capable of phosphorylating the actin-binding protein caldesmon at sites ... | 1993 | 8368270 |
| ca2+ and segment length dependence of isometric force kinetics in intact ferret cardiac muscle. | the influence of ca2+ and sarcomere length on myocardial crossbridge kinetics was studied in ferret papillary muscle by measuring the rate of force redevelopment following a rapid length step that dropped the force to zero. tetanic stimulation with 5 mumol/l ryanodine was used to obtain a steady-state contraction, and segment length was measured and controlled using a sense-coil technique that measures changes in the cross-sectional area of the central region of the muscle. the rate constant for ... | 1993 | 8370118 |
| the mammalian glomerulotubular junction studied by scanning and transmission electron microscopy. | the structure of the junction of glomerulus and tubule was investigated in man and 5 other mammalian species (rat, mouse, ferret, rabbit and pig) by scanning and transmission electron microscopy. the junction between parietal epithelium and proximal tubular epithelium was usually abrupt but varied in position: inside bowman's capsule, especially in the male mouse; at the anatomical tubular origin, in the rat, ferret and man; and down the tubule, in the rabbit. all animals but especially the pig ... | 1993 | 8376192 |
| role of gastric ph in isolation of helicobacter mustelae from the feces of ferrets. | helicobacter mustelae colonizes the gastric mucosa of ferrets and causes persistent chronic gastritis. | 1993 | 8380398 |
| mechanisms of ca(2+)-independent contraction in single permeabilized ferret aorta cells. | the mechanisms by which prostaglandin f2 alpha (pgf2 alpha) can cause contractions at constant intracellular ca2+ were investigated by the direct measurement of force from single saponin-permeabilized smooth muscle cells from the ferret aorta. the size of pgf2 alpha contractions did not change between pca 9.0 and pca 6.6. the remainder of the experiments were carried out at pca 7.0. at pca 7.0, pgf2 alpha (0.1-100 microm) induced sustained force in a dose-dependent manner, reaching a maximum (2. ... | 1993 | 8381724 |
| functional islet cell tumor in six ferrets. | functional islet cell tumor was diagnosed in 6 ferrets. prominent clinical signs included weight loss, hind limb weakness, ptyalism, and tremors. the diagnosis was made on the basis of 2 or more of the following methods and confirmed by histologic examination of biopsied tissue: hypoglycemia on routine serum biochemical analysis, clinical signs of hypoglycemia, simultaneous development of hypoglycemia (44 +/- 9.9 mg/dl; mean +/- sd), and hyperinsulinemia (58 +/- 18.4 microu/ml; mean +/- sd) afte ... | 1993 | 8382672 |
| the effect of acidosis on beta-adrenergic receptors in ferret cardiac muscle. | acidosis decreases the force of contraction of cardiac muscle in response to noradrenaline. the role of beta-adrenergic receptors in this response to acidosis was investigated. radioligand techniques were used to determine beta-adrenergic receptor number and the degree of g-protein coupling, and to see whether these were altered in tissues subject to acidosis. the effect of ph on agonist and antagonist binding to these receptors was also investigated. tissue pre-exposure to acidic conditions had ... | 1993 | 8383505 |
| luteal protein secretion during preimplantation in the ferret. | ferret cl were collected on days 5-11 of pregnancy or pseudopregnancy and incubated in mccoy's medium with radiolabeled amino acids to determine the ability of ferret cl to synthesize and secrete proteins during the preimplantation period. products recovered from the medium were separated by one- and two-dimensional sds-page followed by fluorography and were quantified by densitometry. selected secretory proteins were tentatively identified with specific antibodies on western blots. ferret cl sy ... | 1993 | 8384008 |
| effects of extracellular atp on ica, [ca2+]i, and contraction in isolated ferret ventricular myocytes. | the effects of extracellular atp on the voltage-activated "l-type" ca current (ica), action potential, resting and transient intracellular ca2+ levels, and cell contraction were examined in enzymatically isolated myocytes from the right ventricles of ferrets. with the use of the whole cell patch-clamp technique, extracellular atp (10(-7) to 10(-3) m) inhibited ica in a time- and concentration-dependent manner. atp decreased the peak amplitude of ica without altering the residual current at the e ... | 1993 | 8384788 |
| litoxetine: a selective 5-ht uptake inhibitor with concomitant 5-ht3 receptor antagonist and antiemetic properties. | the selective 5ht uptake inhibitor, litoxetine (sl 81.0385), currently under development as an antidepressant was shown to have antiemetic properties in the ferret. litoxetine (at 1 and 10 mg/kg i.v.) dose dependently reduced the number of retches and vomiting as well as the number of emetic episodes induced by cisplatin (10 mg/kg i.v.) and delayed the onset of emesis. fluoxetine (at 1 or 10 mg/kg i.v.) failed to inhibit cisplatin-induced emetic responses and, in contrast, significantly increase ... | 1993 | 8385615 |
| mechanisms of phi recovery after global ischemia in the perfused heart. | a na(+)-hco3- coinflux carrier and the na(+)-h+ antiport have both been shown to contribute to recovery from intracellular acidosis in cardiac tissue. we have investigated the participation of these mechanisms as well as metabolite (lactate and co2) washout in the recovery of phi after myocardial ischemia. isovolumic ferret hearts were langendorff-perfused with either hco3(-)-buffered or nominally hco3(-)-free (hepes-buffered) medium at 30 degrees c. phi was estimated from the chemical shift of ... | 1993 | 8386598 |
| (imidazolylphenyl)pyrrol-2-one inhibitors of cardiac camp phosphodiesterase. | seven 3-alkyl-4-aryl-1,5-dihydro-2h-pyrrol-2-ones were prepared as potential inhibitors of cardiac camp phosphodiesterase (pde). the design of these compounds made use of rolipram, a known inhibitor of the brain camp pde isozyme, as a lead structure and was guided by a model which describes the features required for potent inhibition of the cardiac isozyme. syntheses for the new compounds are described, together with the results of theoretical and crystallographic studies aimed toward ascertaini ... | 1993 | 8386770 |
| enhancement of transmission at the developing retinogeniculate synapse. | axon terminals from retinal ganglion cells in the left and right eyes initially overlap with each other in the lateral geniculate nucleus of the neonatal ferret, then segregate into eye-specific layers via an activity-dependent process. brain slices were used to show that, during this period of reorganization, retinal terminals within the lateral geniculate nucleus evoke excitatory postsynaptic currents composed of both nmda and non-nmda receptor-mediated currents. the amplitude of these current ... | 1993 | 8388224 |
| electrophysiological examination of the representation of the face in the suprasylvian gyrus of the ferret: a correlative study with cytoarchitecture. | using high-resolution microelectrode mapping methods, we explored the organization of the face representation within the primary somatosensory cortex of ferrets, finding evidence for at least two and probably four representations of the face distributed consecutively from anterior to posterior along the long axis of the suprasylvian gyrus. examination of the cytoarchitecture (rice et al., this issue) revealed that these four areas corresponded to four different cytoarchitectonic fields within th ... | 1993 | 8392240 |
| cytoarchitecture of the ferret suprasylvian gyrus correlated with areas containing multiunit responses elicited by stimulation of the face. | the cytoarchitecture was studied in a segment of the ferret suprasylvian gyrus containing at least two and possibly four somesthetic representations of the face that were observed in the primary somatosensory cortex. these representations were restricted to the crown of the gyrus and were surrounded by somesthetically unresponsive cortex that extended down both sides to the base of adjacent sulci. numerous cytoarchitectonic subdivisions were found on a qualitative basis, and were confirmed quant ... | 1993 | 8392241 |
| cellular mechanisms of a synchronized oscillation in the thalamus. | spindle waves are a prototypical example of synchronized oscillations, a common feature of neuronal activity in thalamic and cortical systems in sleeping and waking animals. spontaneous spindle waves recorded from slices of the ferret lateral geniculate nucleus were generated by rebound burst firing in relay cells. this rebound burst firing resulted from inhibitory postsynaptic potentials arriving from the perigeniculate nucleus, the cells of which were activated by burst firing in relay neurons ... | 1993 | 8392750 |
| cytokine release from human peripheral blood leucocytes incubated with endotoxin with and without prior infection with influenza virus: relevance to the sudden infant death syndrome. | previous work with a neonatal ferret model for human sids had indicated that inflammation caused by a combination of influenza virus and bacterial endotoxin may be a cause of human sids. to determine whether cytokines may be involved in this inflammatory response, levels of interleukin (il)-1 beta, il-6 and tumour necrosis factor (tnf)-alpha were examined, using elisa assays, in culture supernatants of human peripheral blood leucocytes infected with influenza virus and subsequently incubated wit ... | 1993 | 8392861 |
| regulation of intracellular ph in the perfused heart by external hco3- and na(+)-h+ exchange. | both na(+)-dependent hco3- influx and the na(+)-h+ antiport have been shown to contribute to recovery from intracellular acidosis in avian and mammalian cardiac tissue. we have investigated the participation of these mechanisms in the recovery of intracellular ph (phi) after an acid load in the langendorff-perfused ferret heart. phi was measured from the phosphorus-31 nuclear magnetic resonance chemical shift of 2-deoxy-d-glucose 6-phosphate. basal phi was higher in hco(3-)-buffered solution (7. ... | 1993 | 8393626 |
| alterations in contractile properties and ca2+ transients by beta-and muscarinic receptor stimulation in ferret myocardium. | 1. to clarify the mechanism which regulates the time course of twitch tension when beta- and muscarinic receptors are stimulated, intracellular ca2+ transients, ca2+ sensitivity of the contractile element and the cross-bridge cycling rate (ccr) were measured in ferret ventricular muscles. 2. isoprenaline (iso; 0.1 microm) increased peaks of ca2+ transients measured with aequorin and tension, and abbreviated the time courses of both signals. addition of acetylcholine (ach; 0.01-1 microm) to the i ... | 1993 | 8394423 |
| mechanism of the effects of acetylcholine on the contractile properties and ca2+ transients in ferret ventricular muscles. | 1. we investigated the mechanism of signal transduction during the effect of muscarinic receptor stimulation on ca2+ transients, tension, ca2+ sensitivity and the cross-bridge cycling rate (ccr). 2. membrane-permeable derivatives of cyclic gmp (8-bromo-cyclic gmp and dibutyryl cyclic gmp) did not cause any significant changes in the peaks of ca2+ transients and tension and the time courses of either signal modulated by isoprenaline (iso) (0.1 microm). 3. nitroprusside (0.1-1 mm) likewise did not ... | 1993 | 8394424 |
| light- and electron-microscopic immunocytochemistry of somatotropes in the anterior pituitary gland of european ferret, mustela putorius furo. | light-microscopic immunocytochemistry of ferret anterior pituitary revealed the localization of somatotropes in the pars distalis, but no immunoreactive cells were detected in the pars tuberalis. ultrastructural studies by superimposition immunocytochemistry and immuno-electron microscopy, elucidated the morphological heterogeneity of these somatotropic cells. they were classified into 2 subtypes on the basis of size of the secretory granules. type-i cells with small granules (mean diameter, 192 ... | 1993 | 8402825 |
| mnng-induced gastric carcinoma in ferrets infected with helicobacter mustelae. | n-methyl-n-nitro-n'-nitrosoguanidine (mnng) is a gastric carcinogen in several animal species and has been used in a number of systems to dissect the co-carcinogenic potential of various compounds in the induction of gastric adenocarcinoma. recent epidemiological evidence suggests that helicobacter pylori may play a role as a co-carcinogen in the etiology of this tumor in humans and we have been interested in developing an animal model to study this possibility. a related organism, h. mustelae, ... | 1993 | 8403224 |
| characterisation of the peptido-leukotriene receptor pl2 on the ferret spleen strip. | the peptido-leukotriene receptor(s) (pl) on the ferret isolated spleen strip have been characterised by functional studies using the naturally occurring leukotrienes (lts), a range of structurally distinct pl antagonists, and by ligand binding studies. ltb4 (0.01-10 microm) was inactive on ferret spleen whereas ltc4, ltd4 and lte4 produced concentration-related contractions with maximal responses, relative to noradrenaline, of 57% (ec50 0.28 microm), 60% (ec50 0.5 microm) and 7% respectively. th ... | 1993 | 8405079 |
| kinetic analysis of the l-type calcium current in enzymatically dissociated ferret ventricular myocytes. | the l-type calcium current (ica-l) was studied in single ferret ventricular myocytes using whole-cell recording with single patch pipettes. voltage-clamp experiments were performed at room temperature with internal and external na(+)- and k(+)-free tyrode solutions in order to isolate ica-l. for depolarizing steps eliciting small ica-l the decay of the current is best described by one exponential. for depolarizing steps eliciting large ica-l (i.e. between -10 and +30 mv), the decay of the curren ... | 1993 | 8405909 |
| genetic stability and diversity of pneumocystis carinii infecting rat colonies. | there is increasing molecular and antigenic evidence that pneumocystis carinii organisms isolated from humans, ferrets, and rats are different species. in contrast, little is known about the extent of genetic diversity among p. carinii strains found within a single mammalian species. in the present study, electrophoretic karyotypes were obtained from p. carinii prepared from 10 chronically immunosuppressed rat colonies to investigate diversity at the chromosomal level. most organism preparations ... | 1993 | 8406881 |
| unilateral adrenalectomy as a treatment for adrenocortical tumors in ferrets: five cases (1990-1992). | adrenocortical tumors were diagnosed in 5 adult spayed ferrets. four ferrets had bilaterally symmetrical alopecia of the caudal femoral region, abdomen, and tail, and 1 had alopecia of the distal limbs and feet. all 5 ferrets had vulvar swelling. during abdominal ultrasonography, irregular masses, believed to involve the adrenal glands, were seen in all 5 ferrets. unilateral adrenalectomy was performed successfully in each ferret by use of ventral midline celiotomy. on histologic examination of ... | 1993 | 8407488 |
| hyperadrenocorticism associated with adrenocortical tumor or nodular hyperplasia of the adrenal gland in ferrets: 50 cases (1987-1991). | adrenocortical adenoma, nodular hyperplasia, or carcinoma was diagnosed in 50 ferrets. thirty-five (70%) ferrets were female and 15 (30%) were male. the mean age at which clinical signs were first noticed was 3.4 years (range, 1 to 7 years). clinical signs included large vulva (n = 31; 89% of females), alopecia (n = 43; 86%), pruritus (n = 20; 40%), and increased consumption of water and increased urine output (n = 4; 8%). a mass was palpated at the cranial pole of the kidney during physical exa ... | 1993 | 8407489 |
| lymphoplasmacytic keratitis in a ferret with lymphoma. | unilateral lymphoplasmacytic keratitis was believed to be associated with multicentric lymphoma in a ferret. plasmacytosis (aleutian disease) should be considered in any ferret with lymphoplasmacytic infiltration of any organ. ferrets with antibodies to the parvovirus causing plasmacytosis are believed to be more susceptible to concurrent disease because of immunosuppression. | 1993 | 8407535 |
| 2-(quinuclidin-3-yl)pyrido[4,3-b]indol-1-ones and isoquinolin-1-ones. potent conformationally restricted 5-ht3 receptor antagonists. | several series of n-(quinuclidin-3-yl)aryl and heteroaryl-fused pyridones were synthesized and evaluated for 5-ht3 receptor affinity. in the heteroaryl series, 2-(quinuclidin-3-yl)tetrahydropyrido-[4,3-b]indol-1-one (8a) and the 4,5-alkano-bridged analogues (14 and 15) displayed high 5-ht3 receptor affinity with pki values > 9. the (3s)-quinuclidinyl isomers had > 10 fold higher affinity than the (3r)-isomers. in a series of 2-quinuclidin-3-yl)isoquinolin-1-ones, derivatives substituted with sma ... | 1993 | 8410977 |
| resinferatoxin, an ultrapotent capsaicin analogue, has anti-emetic properties in the ferret. | resinferatoxin (100 micrograms/kg, s.c.), the ultrapotent analogue of capsaicin, when given acutely blocked radiation-(200 rads) and copper sulphate (40 mg% 30 ml, p.o.)-induced emesis in ferrets and substantially decreased loperamide (0.5 mg/kg, s.c.)-induced vomiting, without significantly affecting the von bezold-jarisch reflex or gag reflex. it also produced a decrease in core temperature as has been reported for capsaicin. the observation that resinferatoxin reduced or blocked emesis induce ... | 1993 | 8413843 |
| role of sodium/calcium exchange in the mechanism of myocardial stunning: protective effect of reperfusion with high sodium solution. | this study was conducted to elucidate the role of sodium/calcium (na+/ca2+) exchange in the mechanism of myocardial stunning. | 1993 | 8417067 |
| antibody response to the m2 protein of influenza a virus expressed in insect cells. | a recombinant baculovirus expressing the m2 protein from influenza a/ann arbor/6/60 (h2n2) virus (aa60 virus) was constructed. the expressed m2 protein was recognized by a monoclonal antibody specific for the m2 protein and comigrated with the m2 protein from cells infected with aa60 virus on sds-polyacrylamide gels. immunofluorescence studies indicated that the expressed m2 protein was present on the surface of spodoptera frugiperda (sf9) cells infected with the recombinant baculovirus. immunoa ... | 1993 | 8423445 |
| prenatal development of axon outgrowth and connectivity in the ferret visual system. | the objective of this study was to determine when the retina, lateral geniculate nucleus (lgn), and striate cortex first send out axons, and first connect with each other, during embryonic development in the ferret. specifically, we were interested in the timing relationship between axon outgrowth and known temporal patterns of neurogenesis in the lgn and striate cortex. ferrets (mustela putorius furo) were selected for study because of their immature developmental state in late gestation and re ... | 1993 | 8424921 |
| cell migration in cultured cerebral cortical slices. | in order to investigate the cellular mechanisms of migration and lamination in the mammalian cerebral cortex, we have cultured living slices of the developing telencephalon and tracked the migration of newly generated cortical neurons. slice cultures made from neonatal ferret cortex were maintained in roller tubes and survived well for several weeks in vitro. cells generated on postnatal day (p) 0 or 1 were labeled with the thymidine analog 5-bromo-2-deoxy-uridine (brdu), and their movements wer ... | 1993 | 8432395 |
| development of a 14c-urea breath test in ferrets colonised with helicobacter mustelae: effects of treatment with bismuth, antibiotics, and urease inhibitors. | a 14c-urea breath test analogous to its clinical counterpart is described for use in ferrets naturally or experimentally infected with helicobacter mustelae. the test is performed within a sealed glass metabolism chamber through which air is drawn at a constant rate and expired breath collected into sodium hydroxide. peak 14co2 production occurred approximately 1 hour after substrate administration. both inter- and intra-animal responses were highly reproducible, with mean coefficients of variat ... | 1993 | 8432469 |
| practical venipuncture techniques for the ferret. | as the number of ferrets (mustela putorius furo) used in research and kept as pets continues to rise, so does the need for simple, humane research and diagnostic techniques. we have developed venipuncture methods for the ferret utilizing the jugular and cephalic veins. using these methods it is possible to repeatedly sample moderate volumes of blood and to perform intravenous injections in both conscious and sedated ferrets. | 1993 | 8437432 |
| eustachian tube function in the ferret. | the role of viral upper respiratory tract infections (uri) in the pathogenesis of otitis media (om) may be related to eustachian tube (et) dysfunction. preliminary experimental evidence suggests that the ferret may be an appropriate animal for modeling of pathophysiologic process related to uri's and et dysfunction. in an effort to determine the applicability of this animal model, normal et function was evaluated in 10 ferrets using the inflation-deflation and forced-response testing protocols. ... | 1993 | 8442426 |
| crohn's disease and anastomotic recurrence: microvascular ischaemia and anastomotic healing in an animal model. | microvascular injury and ischaemia may be factors in anastomotic recurrence after resection for crohn's disease. this hypothesis was explored in a ferret model of multifocal intestinal infarction. at laparotomy, isolated loops of small intestine were injected intraarterially with styrene microspheres (test loop) or saline (control). at a second laparotomy 72 h later, test and control loops were divided and an end-to-end anastomosis performed between test loops (n = 2), test and control loops (n ... | 1993 | 8443664 |
| oxidant injury alters barrier function of ferret tracheal epithelium. | to understand the influence of oxidant stress on the barrier function of airway epithelium, we conducted studies to determine the effects of chemically generated reactive oxygen species on permeability, permselectivity, and active ion transport of ferret trachea. we examined the consequences of oxidant injury using ferret trachea mounted in ussing-type chambers and bathed with a modified krebs-henseleit solution containing mannitol and xanthine. we added xanthine oxidase to the luminal bathing s ... | 1993 | 8447429 |
| gastric bacteria other than helicobacter pylori. | since the culture of helicobacter pylori from the human stomach in 1983 there has been renewed interest in other bacteria that had been observed in animal stomachs as early as late in the nineteenth century. many of these bacteria have now been isolated and have been shown to belong to the same genus, helicobacter, which currently contains nine species. study of the gastric helicobacters is important because it provides relevant information about how bacteria can survive in the gastric environme ... | 1993 | 8449568 |
| human dolasetron pharmacokinetics: ii. absorption and disposition following single-dose oral administration to normal male subjects. | dolasetron is a 5-hydroxytryptamine antagonist active at type iii receptors; it is presently undergoing clinical evaluation for the reduction/prevention of cancer chemotherapy-induced nausea and vomiting. a previous study demonstrated that following intravenous administration to healthy male subjects, dolasetron disappeared extremely rapidly from plasma, and less than 1 per cent of the dose appeared in the urine. a major plasma metabolite, reduced dolasetron, peaked rapidly in the plasma. in thi ... | 1993 | 8453023 |
| pneumocystis carinii organisms obtained from rats, ferrets, and mice are antigenically different. | pneumocystis carinii infections were developed in animals immunosuppressed by dexamethasone treatment either from activation of latent infection (ferret) or by transtracheal inoculation with p. carinii-infected lung tissue from the homologous species (rat or mouse). convalescent-phase antisera were obtained by stopping dexamethasone treatment after 2 to 4 weeks and allowing animals 5 to 8 weeks for recovery. p. carinii harvests from infected lungs were purified by differential filtration, solubi ... | 1993 | 8454333 |
| a factor released from coronary vascular endothelium inhibits myocardial contractile performance. | the effect of continuous intracoronary infusion of bradykinin (bk; 10(-6) m) on the myocardial contractile performance of isolated langendorff-perfused ferret hearts was investigated. bk produced a transient but marked inhibition of contractile performance, the changes being fully resolved by 2-3 min. this effect of bk was blocked after disruption of the coronary vascular endothelium with triton x-100 (0.5%). prior infusion of the endothelium-derived relaxing factor (edrf) synthesis inhibitor n ... | 1993 | 8456984 |
| short time-scale lv systolic dynamics: pressure vs. volume clamps and effect of activation. | we recently proposed a new model-based approach to quantifying short time-scale left ventricular (lv) systolic dynamics. in this study we examine the hypothesis that the quantitation of lv dynamics using the proposed approach is independent of external mechanical perturbations and the level of activation. mechanical perturbation independence was assessed in seven isolated ferret hearts in which controlled changes in pressure (pressure clamp) or volume (volume clamp) were introduced at the time o ... | 1993 | 8456995 |
| organization of response areas in ferret primary auditory cortex. | 1. we studied the topographic organization of the response areas obtained from single- and multiunit recordings along the isofrequency planes of the primary auditory cortex in the barbiturate-anesthetized ferret. 2. using a two-tone stimulus, we determined the excitatory and inhibitory portions of the response areas and then parameterized them in terms of an asymmetry index. the index measures the balance of excitatory and inhibitory influences around the best frequency (bf). 3. the sensitivity ... | 1993 | 8459273 |
| intestinal perfusion of beta-carotene in the ferret raises retinoic acid level in portal blood. | to determine whether beta-carotene (beta-c) can serve as a source of intestinally-derived retinoic acid (ra), either 15,15'-[14c]beta-c or unlabeled beta-c was perfused through 30 cm jejunal segments of ferrets in vivo. portal vein blood was sampled periodically via an indwelling catheter. ra was identified in portal blood by comparing retention times in hplc, by uv absorption, and by derivatization (methylation) and subsequent gc-ms analysis. the ra concentration in the portal blood increased 3 ... | 1993 | 8466944 |
| synaptophysin immunohistochemistry reveals inside-out pattern of early synaptogenesis in ferret cerebral cortex. | synaptogenesis in the ferret cerebral cortex was examined from the day of birth to adulthood with an antibody against synaptophysin at the light and electron microscopic levels. due to the premature birth of ferrets, the generation of cells destined to the upper cortical layers and their subsequent migration to their final positions in the cortical plate are largely postnatal events. throughout the newborn ferret cerebral cortex, a high amount of synaptophysin immunoreactivity was present within ... | 1993 | 8468403 |
| chiasmatic course of temporal retinal axons in the developing ferret. | recent studies on the distribution of optic axons in the mature visual pathways, as well as on the genesis of their ganglion cells of origin, suggest that the time of axonal arrival at the optic chiasm determines the side of the brain to which a temporal retinal axon will project. the present study has examined this issue directly in fetal ferrets, by determining the projection of the temporal retina at different developmental stages. fetuses of known gestational age were fixed with paraformalde ... | 1993 | 8468406 |
| in situ hybridization analysis of developmental stages of pneumocystis carinii that are transcriptionally active for a major surface glycoprotein gene. | an abundant glycoprotein on the surface of pneumocystis carinii, termed gpa or gp120, is thought to play a role in the interaction of this opportunistic pathogen with its host. using rna:rna hybridization techniques, the in situ expression of gpa mrna in developmental forms of the organism was investigated in a ferret model of p. carinii pneumonia. the results suggested that the relative abundance of gpa-specific mrna was variable in different developmental stages of ferret p. carinii. p. carini ... | 1993 | 8469111 |
| distribution of calcitonin gene-related peptide immunoreactive nerve fibers in the human submandibular gland. | the indirect immunofluorescence technique was used to study the distribution of calcitonin gene-related peptide (cgrp) in human submandibular gland. a relatively low number of thin varicose fibers with intense immunofluorescence for cgrp was seen in samples from seven glands. these cgrp-immunoreactive (cgrp-ir) nerve fibers were mainly seen around or in close contact with intra- and interlobular blood vessels. some cgrp-ir nerve fibers were also found in association with intra- and interlobular ... | 1993 | 8469411 |
| sarcoplasmic reticulum calcium mobilization in right ventricular pressure-overload hypertrophy in the ferret: relationships to diastolic dysfunction and a negative treppe. | in a model of right-ventricular pressure-overload hypertrophy (poh) in the ferret, action potential duration (to 90% repolarization) was found to be significantly longer (228 +/- 11 vs 314 +/- 12 ms) with no change in amplitude (85 +/- 3 vs 85 +/- 2 mv) or resting membrane potential (-79 +/- 1.5 vs -79 +/- 1 mv) for control and poh, respectively. peak sarcoplasmic reticulum ca2+ release (expressed as the logarithm of the fractional luminescence, -4.2 +/- 0.1 vs -4.4 +/- 0.3) and resting calcium ... | 1993 | 8469611 |
| the regulation of intracellular mg2+ in guinea-pig heart, studied with mg(2+)-selective microelectrodes and fluorochromes. | because of the reported presence of a na(+)-mg2+ exchanger in guinea-pig but not in ferret myocardium, the mg2+ extrusion mechanism in guinea-pig myocardium has been reinvestigated using mg(2+)- and na(+)- selective microelectrodes and the fluorochromes mag-fura-2 and -5. the mean [mg2+]i measured with microelectrodes in trabeculae or papillary muscles was 0.72 mmol/l (n = 22, thirteen experiments; range 0.42-1.23 mmol/l). increasing [mg2+]o from 0.5 mmol/l to either 10.5 or 20 mmol/l caused sma ... | 1993 | 8471242 |
| spontaneous neoplasia in the ferret (mustela putorius furo). | thirteen spontaneous tumours in ferrets from two laboratory breeding colonies are described, including two types not previously reported in this species, namely, uterine teratoma and neurilemmoma. the literature on tumours in laboratory and domestic ferrets is comprehensively reviewed from the first reported case in 1950. only 20 cases were reported from 1950 to 1979, nearly all from laboratory or zoological collections. in the following 10 years more than 170 further cases were reported, about ... | 1993 | 8473565 |
| recurrent mycobacterium bovis infection following a ferret bite. | | 1993 | 8473774 |
| studies directed toward the design of orally active renin inhibitors. 2. development of the efficacious, bioavailable renin inhibitor (2s)-2-benzyl-3- [[(1-methylpiperazin-4-yl)sulfonyl]propionyl]-3-thiazol-4-yl-l-alanine amide of (2s,3r,4s)-2-amino-1-cyclohexyl-3,4-dihydroxy-6-methylheptane (a-72517). | employing a set of empirical guidelines for the design of well-absorbed renin inhibitors, we have followed two strategies to improve potency while maintaining bioavailability. one process involved incorporation of an extended n-terminal residue bearing a weakly basic substituent and is exemplified by compound 25. the other approach centered on the inclusion of an n-terminal sulfonamide and culminated in the discovery of inhibitor 32 (a-72517). both 25 and 32 showed excellent bioavailability in t ... | 1993 | 8474102 |
| the protective effect of 4-hydroxy-2-methyl-n-[2-(tetrazol-5-yl)- phenyl]-2h-1, 2-benzothiazine-3-carboxamide-1, 1-dioxide monosodium salt (hx-1920) on cisplatin-induced toxicity in rats. | the protective effect of 4-hydroxy-2-methyl-n-[2-(tetrazol-5-yl)-phenyl]-2h-1, 2-benzothiazine-3-carboxamide-1, 1-dioxide monosodium salt (hx-1920) on the nephrotoxicity of cisplatin was studied in rats. effects of hx-1920 on antitumor activity and emesis induced by cisplatin were also examined using mice and ferrets, respectively. all 10 rats injected with both hx-1920 and ld50 of cisplatin survived for 14 days. after 24 hr, co-administration of hx-1920 significantly increased the urinary excre ... | 1993 | 8474148 |
| factors influencing measurement of protein reflection coefficient by filtered volume technique. | in isolated perfused organs, the protein reflection coefficient (sigma) can be estimated by comparing increases in hematocrit (hct) and protein concentration (cp) during transvascular fluid filtration. in this study, we developed an equation for sigma to examine the potential influences of perfusate leak, evaporation, and hemolysis-induced changes in red blood cell volume and perfusate water. we also performed experiments in isolated ferret lungs to quantitate the magnitude of these potential so ... | 1993 | 8482680 |
| estrogen receptor immunoreactive neurons in the fetal ferret forebrain. | the development of estrogen receptors was studied in the preoptic area/anterior hypothalamus (poa/ah) of fetal male and female ferrets. in males this region includes a nucleus (mn-poa/ah), delineated by nissl stains, which is not discernible in females. the results reveal the distribution of estrogen receptor containing cells during the period when estrogen is known to induce the differentiation of the male ferret's mn-poa/ah. brains were taken from ferret kits on days 30, 34, 37 and 40 of a 41- ... | 1993 | 8485841 |
| behavioral studies of emetic sensitivity in the ferret. | the ferrets' responsiveness to several known and putative emetic agents was evaluated using a variety of agents that were injected subcutaneously and/or intravenously. apomorphine was consistently emetic at relatively high doses (100 micrograms/kg) when injected subcutaneously in large male ferrets (> or = 1.4 kg). the responsiveness to apomorphine was anomalous in that subcutaneous injections produced a more consistent response than intravenous ones. in addition, ferrets rapidly become tolerant ... | 1993 | 8495372 |
| neural changes in periapical lesions after systemic steroids in the ferret. | this study was intended to clarify the relationship between the neural changes which occur around the apex of the ferret canine after pulpectomy and the inflammatory process induced by the procedure. in 12 young adult ferrets, under general anesthesia, the pulps in the mandibular canine teeth were removed and replaced with gutta percha and grossman's sealer. six of the animals were treated with dexamethasone to reduce the inflammatory response. three months later, the animals, again under genera ... | 1993 | 8496482 |
| cardiac electrophysiologic and antiarrhythmic actions of 3,4-dihydro-1'-[2-(benzofurazan-5-yl) ethyl]-6-methanesulfonamidospiro [(2h)-1-benzopyran-2,4'-piperidin]-4-one hcl (l-691,121), a novel class iii agent. | the cardiac electrophysiologic and antiarrhythmic actions of 3,4-dihydro-1'-[2-(benzofurazan-5-yl)ethyl]-6-methyl-sulfonamid ospiro [(2h)-1-benzopyran-2,4'-piperidin]-4-one hcl (l-691,121), a novel spirobenzopyran piperidine class iii agent, were assessed in vitro and in vivo. in ferret isolated papillary muscles, l-691,121 significantly prolonged effective refractory period (ec25 = 13 nm) and elicited a modest positive inotropic effect. in guinea pig isolated ventricular myocytes, l-691,121 pro ... | 1993 | 8496818 |
| calcium sensitivity of skinned ferret edl, soleus, and cremaster fibers. | the properties of the contractile system at different times of the year in the ferret extensor digitorum longus (edl), soleus and cremaster muscles were examined by using chemically skinned (triton x-100) preparations. the results show clear differences in calcium sensitivity between these skeletal muscles. the apparent calcium threshold for activation was lower in soleus than in edl, while calcium concentrations ([ca2+]) required to obtain the half-maximal tension, expressed as pca50 (-log[ca2+ ... | 1993 | 8498595 |
| helicobacter mustelae and helicobacter pylori bind to common lipid receptors in vitro. | helicobacter pylori is a recently recognized human pathogen causing chronic-active gastritis in association with duodenal ulcers and gastric cancer. helicobacter mustelae is a closely related bacterium with similar biochemical and morphologic characteristics. h. mustelae infection of antral and fundic mucosa in adult ferrets causes chronic gastritis. an essential virulence property of both helicobacter species is bacterial adhesion to mucosal surfaces. the aim of this study was to determine whet ... | 1993 | 8500901 |
| cloning and genetic characterization of the helicobacter pylori and helicobacter mustelae flab flagellin genes and construction of h. pylori flaa- and flab-negative mutants by electroporation-mediated allelic exchange. | helicobacter pylori is one of the most common human pathogens. it causes chronic gastritis and is involved in the pathogenesis of gastroduodenal ulcer disease and possibly gastric carcinoma. helicobacter mustelae is a bacterium closely related to h. pylori that causes gastritis and ulcer disease in ferrets and is therefore considered an important animal model of gastric helicobacter infections. motility, even in a viscous environment, is conferred to the bacteria by several sheathed flagella and ... | 1993 | 8501031 |
| the calcium-independent transient outward potassium current in isolated ferret right ventricular myocytes. i. basic characterization and kinetic analysis. | enzymatically isolated myocytes from ferret right ventricles (12-16 wk, male) were studied using the whole cell patch clamp technique. the macroscopic properties of a transient outward k+ current i(to) were quantified. i(to) is selective for k+, with a pna/pk of 0.082. activation of i(to) is a voltage-dependent process, with both activation and inactivation being independent of na+ or ca2+ influx. steady-state inactivation is well described by a single boltzmann relationship (v1/2 = -13.5 mv; k ... | 1993 | 8505627 |
| the calcium-independent transient outward potassium current in isolated ferret right ventricular myocytes. ii. closed state reverse use-dependent block by 4-aminopyridine. | block of the calcium-independent transient outward k+ current, i(to), by 4-aminopyridine (4-ap) was studied in ferret right ventricular myocytes using the whole cell patch clamp technique. 4-ap reduces i(to) through a closed state blocking mechanism displaying "reverse use-dependent" behavior that was inferred from: (a) development of tonic block at hyperpolarized potentials; (b) inhibition of development of tonic block at depolarized potentials; (c) appearance of "crossover phenomena" in which ... | 1993 | 8505628 |
| the ferret as a model for evaluation of the bioavailabilities of all-trans-beta-carotene and its isomers. | the objective was to develop the ferret as a model for evaluation of the bioavailabilities of natural and synthetic beta-carotenes in foods. for these studies, a low carotenoid purified diet was formulated that produced excellent food intake and adequate growth. after consuming the diet for 16 d, ferrets were randomly assigned to one of three groups. for a 10-d period, they ingested a standardized amount of all-trans-beta-carotene (18 mumol/l) from either carrot juice, a test beverage of beta-ca ... | 1993 | 8505674 |
| resting and end-diastolic [ca2+]i measurements in the langendorff-perfused ferret heart loaded with a 19f nmr indicator. | intracellular free calcium concentration ([ca2+]i) was measured in langendorff-perfused ferret hearts (30 degrees c, ph 7.4) by loading paced hearts with the 19f nmr calcium indicator, the 5,5'-difluoro derivative of 1,2-bis(o-aminophenoxy)ethane-n, n,n',n'-tetraacetic acid (5fbapta), to an initial cytosolic concentration of approximately 120 microm. increasing the pacing frequency raised the end-diastolic [ca2+]i from 299 +/- 44 nm (mean +/- sem) at 0.2 hz to 522 +/- 54 nm at 1.0 hz and 691 +/- ... | 1993 | 8505896 |
| crossbridge scheme and the kinetic constants of elementary steps deduced from chemically skinned papillary and trabecular muscles of the ferret. | elementary steps of the crossbridge cycle in chemically skinned ferret myocardium were investigated with sinusoidal analysis. the muscle preparations were activated at pca 4.82 and an ionic strength of 200 mm, and the effects of the change in the mgatp (s) and phosphate (pi) concentrations on three exponential processes were studied at 20 degrees c. results are consistent with the following crossbridge scheme: [formula: see text] where a is actin, m is myosin, d is mgadp, and det includes all de ... | 1993 | 8508533 |
| differential effects of the optical isomers of emd 53998 on contraction and cytoplasmic ca2+ in isolated ferret cardiac muscle. | emd 53998 (a thiadiazinone) is a novel inotropic substance that increases the ca2+ sensitivity of the myofilaments in skinned cardiac fibers and has been found to have similar effects in intact cardiac muscle. however, the compound also possesses the ability to inhibit phosphodiesterase iii, indicating that its actions in intact cardiac muscle are likely to be complex. the present study was carried out to investigate the possibility that the optical isomers of emd 53998--(+)emd 57033 and (-)emd ... | 1993 | 8508534 |
| laterality of superior olive projections to the inferior colliculus in adult and developing ferret. | the laterality of projections from the lateral superior olivary nucleus (lso) to the inferior colliculus was studied in adult and immature postnatal ferrets. in the adult ferret, large unilateral injections of horseradish peroxidase (hrp) in the inferior colliculus labeled about equal proportions of cells in the ipsilateral and contralateral lateral superior olivary nuclei. the contralateral labeled cells consistently were more densely labeled than those on the ipsilateral side. double labeling ... | 1993 | 8509504 |
| healing of induced periapical lesions in ferret canines. | a previous study showed that the ferret canine is an appropriate model for inducing periapical lesions. ferret canines were used in this study to study changes in periapical lesions after root canal treatment (rct). after periapical pathosis was induced in the maxillary and mandibular canines of six ferrets, rct was performed on three of the four canines in each animal. each ferret received periodic intraperitoneal injections of procion red dye. two animals were killed at each of 4, 8, and 12 wk ... | 1993 | 8509750 |
| pneumocystis carinii is not universally transmissible between mammalian species. | in a series of five experiments, we attempted to transmit pneumocystis carinii from ferrets to scid mice by intratracheal inoculation. using highly specific and sensitive assay techniques, we could not document infection of scid mice by p. carinii isolated from ferrets. in contrast, under identical inoculation conditions, p. carinii was easily transmissible from one scid mouse to another. these results indicate that p. carinii organisms, at least those isolated from ferrets, have a restricted ho ... | 1993 | 8514391 |
| further evidence of host species-specific variation in antigens of pneumocystis carinii using the polymerase chain reaction. | to further elucidate the extent of variation among pneumocystis carinii obtained from different mammalian hosts, polymerase chain reaction (pcr) analysis of the genes encoding two antigens of p. carinii was done. using primers based on the ferret p. carinii glycoprotein (gp)a gene and the rat p. carinii 45- to 55-kda antigen gene, amplification was attempted with dna isolated from p. carinii-infected ferret, rat, mouse, and human lungs. for both genes, amplification was successful only with p. c ... | 1993 | 8515107 |
| reference values for organ weight, hematology and serum chemistry in the female ferret (mustela putrius furo). | organ weight, hematologic and blood chemistry values were determined to establish reference values in the female ferret. organ weight per kg body weight was calculated for various organs. body surface area (bsa) was also determined by the direct method, and k values (constant) were calculated. the k value was 3.48 in the dubois and dubois equation, and 9.69 in the meeh-rubner equation. blood samples were used to record 10 hematologic and 57 serum (plasma) chemistry values, and 7 immunological pa ... | 1993 | 8519287 |
| analysis of genetic diversity at the arom locus in isolates of pneumocystis carinii. | the dna sequences of a portion of the 5-enolpyruvyl shikimate phosphate synthase domain of the arom gene, encoding the pentafunctional arom protein, were determined from isolates of pneumocystis carinii from five mammalian host species (rat, human, ferret, rabbit and mouse). high levels of genetic divergence were found among p. carinii derived from different host species, 7-22% at the dna sequence level, and 7-26% at the derived amino acid sequence level. two separate and distinct sequences were ... | 1995 | 8520580 |
| pharmacology of l-754,142, a highly potent, orally active, nonpeptidyl endothelin antagonist. | l-754,142, (-)-n-(4-iso-propylbenzenesulfonyl)-alpha-(4-carboxyl-2-n-propy lphenoxy)-3,4- methylenedioxyphenylacetamide, is a potent nonpeptidyl endothelin antagonist (e.g., ki: cloned human eta = 0.062 nm: cloned human etb = 2.25 nm), with high specificity for endothelin receptors. in vitro, l-754,142 is a potent antagonist of et-1-induced phosphatidyl inositol hydrolysis in chinese hamster ovary cells expressing cloned human endothelin receptors (ic50: heta = 0.35 nm; hetb = 26 nm) and of et-1 ... | 1995 | 8531124 |
| the influence of endothelium-derived nitric oxide on myocardial contractile function. | nitric oxide released by cardiac endothelial cells modulates myocardial contractile function through elevation of intracellular 3',5'-cyclic guanosine monophosphate (cgmp). in the absence of agonist stimulation, nitric oxide typically enhances myocardial relaxation and reduces diastolic tone, without significantly altering the rate of force or pressure development. this pattern of effect is observed with nitric oxide or with cgmp analogues in isolated rat cardiac myocytes, isolated ferret papill ... | 1995 | 8537145 |
| mechanisms of the frank-starling phenomena studied in intact hearts. | the impact of ventricular volume on the relationship between intracellular calcium and ventricular pressure under steady-state conditions was determined in intact ferret hearts. the results reveal major quantitative differences and minor qualitative differences between these relations and those previously measured in isolated intact and skinned cardiac muscle. the importance of these differences is discussed within the context of developing a comprehensive mechanistic theory to describe load-dep ... | 1995 | 8540392 |
| helicobacter infections in laboratory animals: a model for gastric neoplasias? | evidence is rapidly accumulating that helicobacter pylori is a major risk factor for human gastric adenocarcinomas and all low-grade b-cell gastric lymphomas. given this, there is a need to develop animal models with a view to discovering not only how carcinogenesis is initiated, but also how the process can be prevented. the lack of h. pylori animal models suitable for long-term studies means that alternatives are needed. the most productive models are likely to be the helicobacter mustelae-inf ... | 1995 | 8541035 |
| estrogen receptor immunoreactivity in ferret brain is regulated by estradiol in a region-specific manner. | the effects of estrogen on estrogen receptor (er) immunoreactivity in the male ferret brain were examined. estrogen treatment reduced the mean number of er-immunopositive (er+) cells/unit area in periventricular preoptic area but increased the mean number of er+ cells/unit area in the medial division of the ventromedial hypothalamic nucleus, while having no effect on the number of er+ cells/unit area in the lateral vmh and arcuate nucleus. thus, estrogen regulates brain er immunoreactivity in ma ... | 1995 | 8542308 |
| discovery of an orally bioavailable nk1 receptor antagonist, (2s,3s)-(2-methoxy-5-tetrazol-1-ylbenzyl)(2-phenylpiperidin-3-yl)amine (gr203040), with potent antiemetic activity. | the antiemetic, pharmacokinetic, and metabolic profile of cp-99,994, a potent nk1 receptor antagonist, has been carefully evaluated. as a result we began a medicinal chemistry program which initially identified a 3-furanyl analogue (6) with improved antiemetic potency and a methyl sulfone (5) with enhanced metabolic stability and oral bioavailability. the improved pharmacokinetic profile of methyl sulfone (5) was associated with its low lipophilicity, and a therefore a number of heterocyclic ana ... | 1995 | 8544174 |
| chemical modulation of 5-ht3 and 5-ht4 receptors affects the release of 5-hydroxytryptamine from the ferret and rat intestine. | in species which vomit, elevated intestinal serotonin (5-hydroxytryptamine, 5-ht) may stimulate abdominal vagal afferent fibers, which in turn evoke the vomiting reflex. the release of 5-ht from intestinal enterochromaffin (ec) cells is regulated by polymodal mechanisms. the object of this study was to evaluate the involvement of 5-ht autoreceptors in the regulation of 5-ht release from the small intestine. functional studies were carried out using 5-ht3 receptor agonist and antagonists, and 5-h ... | 1995 | 8556268 |
| animal models and vaccine development. | following the demonstration of helicobacter pylori as a major gastroduodenal pathogen there was a need to develop animal models in order to investigate mechanisms of pathogenesis and to be able to test new treatment strategies. helicobacter pylori will only colonize a limited number of hosts including non-human primates, germ-free or barrier raised piglets, germ-free dogs and recently laboratory raised cats. although these models have proved useful there is a need for more convenient small anima ... | 1995 | 8563056 |
| the effect of k+ channel openers on submucosal gland function and epithelial transport of the ferret trachea, in vitro. | the effects of three k+ channel openers on lysozyme output from submucosal gland serous cells and epithelial albumin transport following maintained submaximal stimulation by the secretagogues methacholine and phenylephrine were examined in the ferret trachea in vitro preparation. the k+ channel openers ro 31-6930, 2-(6-cyano-2,2-dimethyl-2h-1-benzopyran-4-yl)-pyridine 1-oxide (10 nm-10 microm), levcromakalim, brl38227 (10 nm-10 microm) and pinacidil (100 nm-10 microm) produced a concentration de ... | 1995 | 8566100 |
| cloning and characterization of a conserved region of human and rhesus macaque pneumocystis carinii gpa. | although the genes encoding pneumocystis carinii (pc) glycoprotein a (gpa) display a high degree of host species-specific genotypic diversity, the pc gpa derived from different host species share defined regions of significant homology in their primary amino acid (aa) structure. using two degenerate oligodeoxyribonucleotide (oligo) primers corresponding to a conserved cys region (cys-primers) of the ferret (f), rat (r) and mouse (m) pcgpa, a 306-bp portion of the human (h) pcgpa was amplified fr ... | 1995 | 8566775 |