| molecular characterization of clustered variants of genes encoding major surface antigens of human pneumocystis carinii. | a 13-kb genomic fragment from human pneumocystis carinii was cloned as repetitive dna. the fragment contains a cluster of three related genes, each 3 kb in size, and the 5' end of a fourth gene. the predicted polypeptide of the first gene in the cluster comprises 1,030 amino acid residues with a total molecular mass of 116 kda. the gene's predicted amino acid sequence bears 32% identity to predicted sequences of recently described gene fragments of ferret p. carinii, which encode an immunodomina ... | 1994 | 7518806 |
| localization of increased collagen in ferret lung tissue after chronic exposure to nitrogen dioxide. | chronic exposure of experimental animals to moderate levels of nitrogen dioxide (no2) leads to increased collagen deposition in the lung parenchyma. to localize this increased collagen, lung sections from ferrets exposed to 0.5 or 10 ppm of no2 4 h daily for 8 or 15 weeks were stained with sirius red under conditions in which the stain is specific for collagen. stained areas of respiratory bronchiolar submucosa were compared between no2-exposed and air-exposed control animals using computer-aide ... | 1994 | 7522361 |
| comparative effects of increased extracellular potassium and pacing frequency on the class iii activities of methanesulfonanilide ikr blockers dofetilide, d-sotalol, e-4031, and mk-499. | the methanesulfonanilide-containing class iii agents dofetilide, d-sotalol, e-4031, and mk-499 have been characterized as selective blockers of a rapidly activating component of the cardiac delayed rectifier (ik) k+ current, ikr. in the present studies, the effects of dofetilide (3-30 nm), d-sotalol (10-100 microm), e-4031 (30-300 nm), and mk-499 (30-300 nm) on myocardial effective refractory period (erp) were assessed in ferret right ventricular papillary muscles in conditions of altered extrac ... | 1994 | 7526051 |
| effects of a newly synthesized dihydropyridine, nz-105, on intracellular ca transients and tension in ferret ventricular muscles. | we investigated the effects of a newly synthesized dihydropyridine (dhp) derivative (nz-105) on intracellular ca transients and contraction in ferret ventricular muscles, using the aequorin method. low concentrations of nz-105 (10(-9)-10(-7) m) showed no significant effects on the light signal of aequorin and tension in twitch. high concentrations of nz-105 (10(-6)-10(-5) m) inhibited the peaks of the light signal and tension without altering their time courses. the relation between the peaks of ... | 1994 | 7526060 |
| agonist-induced redistribution of calponin in contractile vascular smooth muscle cells. | calponin is a thin filament-associated protein that has been implicated in playing an auxiliary regulatory role in smooth muscle contraction. we have used immunofluorescence and digital imaging microscopy to determine the cellular distribution of calponin in single cells freshly isolated from the ferret portal vein. in resting cells calponin is distributed throughout the cytosol, associated with filamentous structures, and is excluded from the nuclear area of the cell. the ratio of surface corte ... | 1994 | 7526695 |
| rabbit and ferret parietal cell inhibition by helicobacter species. | we tested sonicates of helicobacter pylori, h. mustelae, and h. felis for inhibition of acid secretion in rabbit and ferret isolated gastric glands. three h. pylori strains, two of three h. mustelae strains, and two h. felis strains significantly inhibited acid secretion in rabbit cells by 95.2-93.3%, 55.9% and 96.4%, and 83.4-96%, respectively. all helicobacter strains examined inhibited acid secretion by ferret cells by 65.3-76.8%, 89.1-97.6%, and 85.8-92.8%. h. pylori inhibited acid secretion ... | 1995 | 7529671 |
| mechanical determinants of left ventricular relaxation in isovolumically beating hearts. | both pressure and volume have been proposed to determine the speed of left ventricular (lv) relaxation, but their relative importance is not known. accordingly, we used isolated, buffer-perfused, isovolumically beating ferret hearts to study the effects of maximal developed pressure (pdmax) and lv volume (v) on the speed of lv relaxation. experiments were performed at 30 degrees c, and the hearts were paced at a baseline interbeat interval (bi) of 800 ms. pdmax was varied independently of v by u ... | 1995 | 7530916 |
| genetic diversity in human-derived pneumocystis carinii isolates from four geographical locations shown by analysis of mitochondrial rrna gene sequences. | the opportunistic fungal pathogen pneumocystis carinii is a frequent cause of pneumonia in immunocompromised hosts. in this study, we have compared the dna sequences of a portion of the mitochondrial large-subunit rrna gene of p. carinii (an informative locus showing up to 27% differences among isolates of p. carinii from human-, rat-, mouse-, ferret-, rabbit-, and horse-infected lungs) obtained from human-derived isolates from widely disparate geographical areas, including britain, the united s ... | 1994 | 7533779 |
| induction and relief of nasal congestion in ferrets infected with influenza virus. | susceptible ferrets intranasally infected with influenza virus consistently responded with maximal nasal secretion of virus, febrile reaction, and influx of inflammatory cells into nasal lumen on day 2 post infection (d.p.i.). polymorphonuclear leucocytes were the earliest predominant cell, followed by monocytes/macrophages while lymphocytes were maintained as a minor population throughout the 7-day period. nasal congestion level, continuously monitored by computer aided active anterior rhinoman ... | 1995 | 7537523 |
| transmission of a chronic lymphoproliferative syndrome in ferrets. | lymphomas and leukemias are caused by transmissible viruses in a wide variety of species, including humans, cattle, and cats. features of lymphoma in ferrets suggest that it, too, may have an infectious etiology. no agent has been identified. | 1995 | 7538182 |
| studies on nerves of the upper respiratory tract in the ferret and the mink. | the central localization of the superior laryngeal nerve (sln), recurrent laryngeal nerve (rln) and pharyngeal nerve (phar) in the ferret (mustela putorius furo) and mink (mustela vision) was determined by neuronal tract tracing techniques. the anterograde transport of horseradish peroxidase (hrp)/wheat germ aggluttinin conjugated hrp mixtures (wga-hrp) revealed afferent fibres of the sln projecting ipsilaterally in the tractus solitarius (ts) before terminating in the ipsilateral nucleus of the ... | 1995 | 7540189 |
| the anti-emetic effects of cp-99,994 in the ferret and the dog: role of the nk1 receptor. | 1. the selective nk1 receptor antagonist, cp-99,994, produced dose-related (0.1-1.0 mg kg-1, s.c.) inhibition of vomiting and retching in ferrets challenged with central (loperamide and apomorphine), peripheral (cuso4) and mixed central and peripheral (ipecac, cisplatin) emetic stimuli. 2. parallel studies with the enantiomer, cp-100,263 (1 mg kg-1, s.c.), which is > 1,000 fold less potent as a nk1 antagonist, indicated that it was without significant effect against cuso4, loperamide, cisplatin ... | 1995 | 7544198 |
| regional distribution and characterization of nitric oxide synthase activity in the brain of the common marmoset. | the distribution of nitric oxide synthase (nos) within the brain of the common marmoset, a non-human primate species, was investigated using the [3h]l-citrulline formation assay and western blot analysis. no hemispheric asymmetry of specific nos activity was shown. the highest levels of nos were found in the putamen and caudate nucleus--more than twice those in the cortex and the cerebellum, the brain regions with the lowest activities. the regional distribution pattern was similar to that in th ... | 1995 | 7545017 |
| lateral superior olive projections to the inferior colliculus in normal and unilaterally deafened ferrets. | we have examined the projection from the lateral superior olive (lso) to the inferior colliculus (ic) in the ferret, with particular interest in the laterality of the projection and in the effects of unilateral cochlear removal in infancy. large or small deposits of the retrograde tracer wheat germ agglutinin-horseradish peroxidase (wga-hrp) were made in the ic of anesthetized adult ferrets that either were normally hearing or had been unilaterally deafened in infancy (p5 or p25). after 2 days, ... | 1995 | 7545189 |
| patterns of excitation and inhibition evoked by horizontal connections in visual cortex share a common relationship to orientation columns. | combined optical imaging and electrophysiological techniques were used to assess directly the functional nature of long-range excitatory and inhibitory synaptic interactions between orientation columns in area 17 of ferret visual cortex. a significant correlation was found between the layout of iso-orientation columns and the pattern of evoked synaptic inputs between cortical sites: the largest-amplitude inhibitory and excitatory synaptic responses were evoked in single neurons when stimulation ... | 1995 | 7546734 |
| distribution of digestive enzyme activities along intestine in blue fox, mink, ferret and rat. | the activities of amylase, total proteases, monoglyceride lipase, glycyl-leucine dipeptidase and sucrase were investigated in mucosa from five consecutive parts of small intestine in blue fox, mink, ferret and rat. in comparison with rats, the activity gradient of carbohydrates and tpa in mucosa of predatory animals was shifted in the distal direction. the distribution of dipeptidase and monoglyceride lipase along the intestine was similar enough in all animals: the first was exemplarily the sam ... | 1995 | 7553336 |
| influence of substrate nature and immobilization of implanted dentin matrix components during induction of reparative dentinogenesis. | the biological effects of isolated soluble dentin extracellular matrix components on the induction of reparative dentinogenesis in exposed cavities in ferret canine teeth have been shown to be blocked by immobilizing the extracellular matrix components on nitrocellulose or millipore membranes during implantation. this contrasts with the picture of induction of odontoblast-like cell differentiation and reparative dentin deposition on existing insoluble dentin matrix of the exposure walls when the ... | 1995 | 7554930 |
| long-term supplementation of canthaxanthin does not inhibit gastric epithelial cell proliferation in helicobacter mustelae-infected ferrets. | the effect of canthaxanthin (cx), a nonprovitamin a carotenoid, on gastric epithelial proliferation was studied in ferrets colonized with helicobacter mustelae, which causes a chronic gastritis and an increased gastric epithelial cell proliferation. seven spayed female ferrets were dosed by gavage with cx beadlets (50 mg/kg body wt, 5 d/wk) over 2 y, whereas seven control animals were given placebo beadlets. at the end of the 2-y-period, ferrets were killed, and gastric tissues were obtained fro ... | 1995 | 7562083 |
| effect of stretch on contraction and the ca2+ transient in ferret ventricular muscles during hypoxia and acidosis. | the effect of stretch on cardiac muscle contraction and the ca2+ transient was studied during hypoxia and acidosis in isolated ferret ventricular muscles. in control conditions, a maintained stretch produced an immediate increase in tension followed by a slow increase in tension and the ca2+ transient. a stretch between contractions (diastolic stretch) caused only a slow increase in tension and the ca2+ transient, whereas a stretch during the period of contraction (systolic stretch) produced an ... | 1995 | 7573399 |
| mechanisms of hypoxic vasodilation in ferret pulmonary arteries. | to investigate the mechanism of hypoxic pulmonary vasodilation we measured isometric tension in rings from ferret third- to fifth-generation intrapulmonary arteries mounted in organ baths (37 degrees c, 28% o2-5% co2). after precontraction with phenylephrine (pe), hypoxia caused a brief transient vasoconstriction followed by marked vasodilation. endothelial denudation did not affect the steady-state response. in vessels without endothelium, inhibition of cyclooxygenase and nitric oxide synthase ... | 1995 | 7573469 |
| isoform diversity and tandem duplication of the glycoprotein a gene in ferret pneumocystis carinii. | two ferret p. carinii gpa cdna clones were identified that reacted identically with a panel of anti-gpa monoclonal antibodies, although their nucleotide sequences were 22% divergent. each clone hybridized to a single mrna species of 3,600 nucleotides only in p. carinii-infected lung mrna, but rt-pcr analysis demonstrated that these cdna clones were derived from two distinct gpa mrna transcripts. further pcr analysis demonstrated that the ferret p. carinii genome contains at least two gpa genes l ... | 1995 | 7584051 |
| preclinical efficacy of a prototype dna vaccine: enhanced protection against antigenic drift in influenza virus. | vaccination with plasmid dna expression vectors encoding foreign proteins elicits antibodies and cell-mediated immunity and protects against disease in animal models. we report a comparison of dna vaccines, using contemporary human strains of virus, and clinically licensed (inactivated virus or subvirion) vaccines in preclinical animal models, to better predict their efficacy in humans. influenza dna vaccines elicited antibodies in both non-human primates and ferrets and protected ferrets agains ... | 1995 | 7585127 |
| effects of thapsigargin on aequorin-injected and skinned preparations of ferret ventricular muscles. | we investigated the effects of thapsigargin (tg) (0.1-1 microm) on the relation between intracellular ca2+ concentration and tension in ferret papillary muscles using aequorin-injected and skinned preparations. | 1995 | 7585826 |
| depressed transient outward current in single hypertrophied cardiomyocytes isolated from the right ventricle of ferret heart. | the aim of this study was to investigate transient outward potassium current (ito) changes as a basis for the prolongation of the action potential associated with cardiac hypertrophy. | 1995 | 7585836 |
| intracellular ph during hypoxia in normal and hypertrophied right ventricle of ferret heart. | the effects of preventing oxidative phosphorylation on phi were compared in papillary muscles from right ventricles of normal and pressure-overloaded ferret hearts. hypertrophy was induced by pulmonary artery clipping for 30-45 days. phi was recorded with ph-sensitive microelectrodes. resting phi and the relationship between intracellular buffering power and phi were not modified by the hypertrophy. at 22 degrees c, the initial intracellular alkalosis following exposure to oxygen-free tyrode sol ... | 1995 | 7602610 |
| von willebrand factor in plasma, platelets, and selected tissues of ferrets. | by standard laboratory methods the presence and activity of von willebrand factor (vwf) was detected and characterized in the ferret (mustela putorius furo); vwf in plasma, platelets, and selected tissues (thoracic aorta, cranial vena cava, thoracic portion of caudal vena cava, and lung) was documented. activity, antigenic concentration, plasma multimeric distribution, and localization within tissues were similar to those features in other species. two differences were apparent: multimeric distr ... | 1995 | 7603015 |
| different effects of salmeterol, formoterol and salbutamol on cholinergic responses in the ferret trachea. | 1. in the present study, the inhibitory effects of the selective beta 2-adrenoceptor agonists, salmeterol, formoterol and salbutamol, have been investigated on contractions of ferret trachea induced both by endogenous and exogenous acetylcholine. the aim of the study was to evaluate quantitative and/or qualitative differences in response which may indicate both pre- and post-junctional sites of action. the non-selective beta-antagonist, sotalol, was used to estimate beta-adrenoceptor involvement ... | 1995 | 7606351 |
| development of glycinergic cells and puncta in nuclei of the superior olivary complex of the postnatal ferret. | the distribution of glycine-immunopositive cells and axonal endings was studied in the adult and early postnatal ferret superior olive. as in other species, the most prominent glycine-immunopositive cell group in the adult ferret superior olive was the medial nucleus of the trapezoid body. other darkly immunostained cells were present, although more scattered, in most periolivary regions, including the lateral and ventral trapezoid body nuclei. in the lateral superior olivary nuclei, glycine-imm ... | 1995 | 7608333 |
| responses of ferret lower esophageal sphincter to 5-hydroxytryptamine: pathways and receptor subtypes. | in urethananesthetized ferrets, basal lower esophageal sphincter pressure (lesp) was unaffected by the 5-hydroxytryptamine3 (5-ht3) receptor antagonist granisetron (0.5 mg/kg) or by greater splanchnic nerve section (gsx), but increased after bilateral vagotomy. peripheral vagal nerve stimulation caused les relaxation, often followed by a brief contraction and a prolonged inhibition of lesp. close intra-arterial injection of 5-ht (5-100 micrograms) had a biphasic effect on lesp, with a brief drop ... | 1995 | 7611399 |
| supplementing ferrets with canthaxanthin affects the tissue distributions of canthaxanthin, other carotenoids, vitamin a and vitamin e. | to study the effects of canthaxanthin supplementation on the tissue distribution of canthaxanthin, other carotenoids, vitamin a and vitamin e, 26 spayed female ferrets (2 mo of age) were used. ferrets were assigned to receive a commercial ferret diet and a gavage of canthaxanthin [50 mg/(kg body wt.d)] or a gavage of placebo beadlets (0 mg canthaxanthin) 5 d/wk. serum canthaxanthin concentrations in the canthaxanthin-fed group increased from 0 at baseline to 37.76 +/- 5.34 nmol/l trans and 77.10 ... | 1995 | 7616312 |
| emergence of functional circuits in ferret visual cortex visualized by optical imaging. | the emergence of functional lateral interactions in ferret visual cortex was monitored using high speed optical imaging of voltage-sensitive dye signals in brain slices. prior to the time of eye opening, lateral activation was restricted to a narrow columnar region. during the week following eye opening, the extent of lateral propagation of activity more than doubled. selective interruption of specific pathways in the slice, combined with pharmacological and anatomical experiments, determined th ... | 1995 | 7619527 |
| axonal target choice and dendritic development of ferret beta retinal ganglion cells. | we have investigated the relationship between axon targeting and dendritic morphology in beta retinal ganglion cells in the postnatal ferret. axonal projections were assessed by making separate injections of different fluorescent retrograde tracers into either the superior colliculus or lateral geniculate nucleus in vivo. the dendritic morphology of retrogradely labelled cells was revealed by the in vitro intracellular injection of lucifer yellow in fixed retina. in this way, 405 retinal ganglio ... | 1995 | 7620621 |
| acetylcholine excites gabaergic neurons of the ferret perigeniculate nucleus through nicotinic receptors. | 1. the actions of acetylcholine (ach) on the gabaergic neurons of the perigeniculate nucleus (pgn) were investigated with the use of extra- and intracellular recording techniques in spontaneously spindling ferret thalamic slices maintained in vitro. 2. local application of ach to pgn neurons resulted in rapid depolarization followed by a longer lasting hyperpolarization. neither of these responses were abolished by blockade of synaptic transmission with tetrodotoxin (ttx) nor with low ca2+ and e ... | 1995 | 7623105 |
| fluid and protein secretion from ferret submandibular and parotid glands in response to sympathetic nerve stimulation or administration of sympathomimetics. | electrical stimulation of the sympathetic innervation evoked secretion of submandibular and parotid saliva. by changing the mode of stimulation from a continuous to an intermittent one the fluid response increased and glandular blood flow improved. the volumes from the submandibular glands were larger than those from the parotid glands and further, the protein concentration of submandibular saliva was higher than that of parotid saliva. adrenaline, isoprenaline and phenylephrine evoked larger fl ... | 1995 | 7625175 |
| reactionary dentinogenesis. | reactionary dentinogenesis is the secretion of a tertiary dentine matrix by surviving odontoblast cells in response to an appropriate stimulus. whilst this stimulus may be exogenous in nature, it may also be from endogenous tissue components released from the matrix during pathological processes. implantation of isolated dentine extracellular matrix components in unexposed cavities of ferret teeth led to stimulation of underlying odontoblasts and a response of reactionary dentinogenesis. affinit ... | 1995 | 7626417 |
| regulation of brain androgen receptor immunoreactivity by androgen in prepubertal male ferrets. | during pubertal maturation, there is an increase in the number of androgen receptor-immunoreactive (ar-ir) cells in the preoptic area (poa), arcuate nucleus (arc), medial amygdala (mamy), and ventromedial hypothalamic nucleus (vmh) of the male ferret brain. in contrast, the number of ar-ir cells in the bed nucleus of the stria terminalis (bnst) or lateral septum (isep) does not change with pubertal development. this experiment tested the hypothesis that the pubertal increase in ar-ir cells in ce ... | 1995 | 7626721 |
| beta 3-adrenoceptors and airways. | beta 3-adrenoceptors have been identified in a variety of tissues from humans and animals: adipose tissue, gastrointestinal smooth muscle, rat skeletal muscle, bovine skeletal muscle, and human and canine heart. in the airways, the investigation of the beta 3-adrenoceptors came from studies with a series of novel selective agonists. stimulation of the "atypical" beta-adrenoceptor increases the active transport of albumin across the ferret tracheal epithelium and the ciliary beat frequency of can ... | 1995 | 7628823 |
| a model of parasagittal controlled cortical impact in the mouse: cognitive and histopathologic effects. | controlled cortical impact (cci), using a pneumatically driven impactor to produce traumatic brain injury, has been characterized previously in both the ferret and in the rat. in the present study, we applied this technique to establish and characterize the cci model of brain injury in another species, the mouse, evaluating cognitive and histopathologic outcome. in anesthetized (sodium pentobarbital, 65 mg/kg) male c57bl mice, we performed sham treatment (no injury, n = 12) or cci injury (n = 12 ... | 1995 | 7629863 |
| time- and voltage-dependent modulation of a kv1.4 channel by a beta-subunit (kv beta 3) cloned from ferret ventricle. | in mammals, voltage-gated k+ channels can be made of complexes containing alpha-subunits similar to the shaker k+ channel and smaller cytoplasmic beta-subunits. recent studies have suggested that these ancillary beta-subunits can modulate k+ channel gating properties. we studied the effects of a k+ channel beta-subunit, kv beta 3, coexpressed with a kv1.4 alpha-subunit, fk1, on the time and voltage dependence of channel activation, inactivation, recovery from inactivation, and deactivation, usin ... | 1995 | 7631872 |
| effect of helicobacter mustelae infection on ferret gastric epithelial cell proliferation. | the effect of helicobacter mustelae infection on gastric epithelial proliferation was studied in ferrets colonized with h.mustelae and specific pathogen-free (spf) ferrets not infected with h.mustelae. thirteen h. mustelae-infected ferrets between the ages of 13 and 32 months and 16 spf ferrets between 6 and 18 months were analyzed. bacterial cultures, urease tests and warthin-starry stains were used to identify h.mustelae. tissues obtained from the antrum and the body regions of the stomach wer ... | 1995 | 7634423 |
| presence and effects of pituitary adenylate cyclase activating peptide in the submandibular gland of the ferret. | pituitary adenylate cyclase activating peptide (pacap), a recently described vasoactive intestinal peptide-like neuropeptide, was found to be present in neurons in the submandibular gland of the ferret, where pacap-immunoreactive nerve fibers were distributed around blood vessels, acini and ducts. most of the pacap-immunoreactive fibres were distinct from those storing vasoactive intestinal peptide. pacap occurs in tissues as pacap1-38 and pacap1-27. pacap1-38 and pacap1-27 but not pacap16-38 di ... | 1995 | 7637871 |
| construction and characterization of an isogenic urease-negative mutant of helicobacter mustelae. | helicobacter mustelae infects the ferret stomach and provides an opportunity to study pathogenic determinants of a helicobacter species in its natural host. we constructed an isogenic urease-negative mutant of h. mustelae which produced no detectable urease and showed a reduced acid tolerance. this mutant provides an opportunity to further evaluate the role of urease in the pathogenesis of helicobacter infection. | 1995 | 7642313 |
| inability of an isogenic urease-negative mutant stain of helicobacter mustelae to colonize the ferret stomach. | eight ferrets specific-pathogen-free for helicobacter mustelae were given, per dose, approximately 3.0 x 10(7) cfu of either the wild-type parent strain of h. mustelae (nctc 12032) (two ferrets) the isogenic urease-negative mutant strain of h. mustelae (10::tn3km) (four ferrets), or sterile culture broth (two ferrets). infection status was monitored by endoscopic gastric biopsy for urease activity, histopathology, and culture and by serology at 3, 6, 10, and 21 weeks. all ferrets were necropsied ... | 1995 | 7642314 |
| comparison of responses in the anterior and primary auditory fields of the ferret cortex. | 1. characteristics of an anterior auditory field (aaf) in the ferret auditory cortex are described in terms of its electrophysiological responses to tonal stimuli and compared with those of primary auditory cortex (ai). ferrets were barbiturate-anesthetized and tungsten microelectrodes were used to record single-unit responses from both ai and aaf fields. units in both areas were presented with the same stimulus paradigms and their responses analyzed in the same manner so that a direct compariso ... | 1995 | 7643163 |
| postnatal development of synchronized network oscillations in the ferret dorsal lateral geniculate and perigeniculate nuclei. | extracellular and intracellular recordings from slices of ferret dorsal lateral geniculate nucleus (lgnd) at postnatal ages p10-53 were performed to examine the postnatal development of spindle waves and the ability of block of gabaa receptors to alter these spindle waves into a slower, synchronous oscillation. as in prior studies in the adult, intracellular and extracellular recordings at ages p33-53 revealed robust spindle waves to be present in both the lgnd and perigeniculate nucleus (pgn). ... | 1995 | 7643215 |
| effect of environmental tobacco smoke on the metabolism of (-)-trans-benzo[a]pyrene-7,8-dihydrodiol in juvenile ferret lung and liver. | to evaluate the effects of "environmental tobacco smoke" (ets) on developing lungs, juvenile ferrets were exposed to ets at an average total particulate concentration of 381 +/- 97 mg/m3 for 2 h at the breathing zone. twenty-four hours after the exposure, the ferrets were sacrificed and the metabolism of (-)-trans-benzo[a]pyrene-7,8-dihydrodiol was studied in the lung and liver homogenates. the rate of conversion of (-)-trans-benzo[a]pyrene-7,8-dihydrodiol to the ultimate carcinogen (+)-anti-ben ... | 1995 | 7643432 |
| rapid acquisition of dendritic spines by visual thalamic neurons after blockade of n-methyl-d-aspartate receptors. | n-methyl-d-aspartate (nmda) receptors play an important role in the development of retinal axon arbors in the mammalian lateral geniculate nucleus (lgn). we investigated whether blockade of nmda receptors in vivo or in vitro affects the dendritic development of lgn neurons during the period that retinogeniculate axons segregate into on-center and off-center sublaminae. osmotic minipumps containing either the nmda receptor antagonist d-2-amino-5-phosphonovaleric acid (d-apv) or saline were implan ... | 1995 | 7644532 |
| the mechanism underlying the cardiotoxic effect of the toxin from the jellyfish chironex fleckeri. | we have investigated the mechanisms underlying the cardiac effects of the toxin from the box jellyfish chironex fleckeri. papillary muscles isolated from the hearts of ferrets and ventricular myocytes isolated from the hearts of ferrets and rats were used. force, intracellular [ca2+], and membrane potential were monitored in the papillary muscles; contraction, intracellular [ca2+], intracellular [na+], and membrane currents were monitored in the isolated myocytes. application of the toxin to the ... | 1995 | 7645014 |
| alternative splicing of the human shaker k+ channel beta 1 gene and functional expression of the beta 2 gene product. | mammalian voltage-activated shaker k+ channels associate with at least three cytoplasmic proteins: kv beta 1, kv beta 2 and kv beta 3. these beta subunits contain variable n-termini, which can modulate the inactivation of shaker alpha subunits, but are homologous throughout an aldo-keto reductase core. human and ferret beta 3 proteins are identical with rat beta 1 throughout the core while beta 2 proteins are not; beta 2 also contains a shorter n-terminus and has no reported physiological role. ... | 1995 | 7649300 |
| does early monocular enucleation in a marsupial affect the surviving uncrossed retinofugal pathway? | monocular enucleations have been done during early stages (postnatal days 3 to 9) of visual system development of monodelphis domestica, in order to determine whether in this marsupial, as in several eutherian mammals, there are any interactions between the pathways from the two eyes in establishing the uncrossed retinofugal projection. we have examined the distribution and the number of retrogradely labelled ganglion cells that project to the same side of the brain from the surviving eyes short ... | 1995 | 7649832 |
| changes in density of brainstem afferents in ferret primary auditory cortex (ai) during postnatal development. | histochemical methods were used to assess the distribution of 4 neurotransmitters thought to be involved in cortical plasticity. they were measured in the primary auditory cortex of the ferret from just before the onset of hearing. acetylcholinesterase staining was strongest in layers i, iv and vi and there was a gradual increase in the amount of staining from postnatal day (pnd) 21 through to adulthood. serotonin fibres were located mainly in layers i-iii and their density increased gradually o ... | 1995 | 7649837 |
| paf induces relaxation of pulmonary arteries but contraction of pulmonary veins in the ferret. | the present study was designed to determine whether platelet-activating factor (paf) has different effects on pulmonary arteries and veins. third-order pulmonary arterial and venous rings of the ferret were suspended in organ chambers filled with modified krebs-ringer bicarbonate solution (95% o2-5% co2, 37 degrees c) and their isometric tension was recorded. under basal conditions, paf had no effect on the resting tension of arteries but induced an endothelium-dependent contraction of veins. th ... | 1995 | 7653635 |
| comparison of helicobacter mustelae and helicobacter pylori adhesion to eukaryotic cells in vitro. | bacterial adhesion to mucosal surfaces is an important pathogenic mechanism for helicobacter-induced gastritis. the aims of this study were to compare binding of selected helicobacter mustelae and helicobacter pylori strains to lipids extracted from hep-2, chinese hamster ovary, human embryonic lung cells, and ferret gastrointestinal tissues as well as to intact tissue culture cells and to analyze the fatty acids of the receptor. | 1995 | 7657097 |
| bi-stable block by 4-aminopyridine of a transient k+ channel (kv1.4) cloned from ferret ventricle and expressed in xenopus oocytes. | 1. using the two-microelectrode, 'cut open' oocyte, and 'torn off' macropatch voltage clamp techniques, we studied the blocking effects of 4-aminopyridine (4-ap) on two cloned k+ channels expressed in xenopus oocytes, an inactivating k+ channel isolated from ferret ventricle (fk1), and its nh2-terminal deletion mutant (delta nco) which lacks fast n-type inactivation. 2. experiments with a permanently charged, impermeant 4-ap derivative, 4-aminopyridine-methyliodide, indicated that the cationic f ... | 1995 | 7658383 |
| effect of a very early monocular enucleation upon the development of the uncrossed retinofugal pathway in ferrets. | monocular enucleations were done in ferret embryos before or during the earliest stages of development of the retinofugal pathway (e23-e26). the effects on the development of the uncrossed pathway from the surviving eye were assessed on embryonic day 30. this stage was chosen for two reasons: (1) we show that in normal development a substantial uncrossed component from the temporal crescent has developed by e30; and (2) the pathway cannot yet have been affected by the cell death that normally oc ... | 1995 | 7665732 |
| intestinal absorption and metabolism of 9-cis-beta-carotene in vivo: biosynthesis of 9-cis-retinoic acid. | this study was done to examine the intestinal absorption and cleavage of 9-cis-beta-carotene in vivo. a micellar solution, containing either no addition or 10 mumol of 9-cis- or all-trans-beta-carotene, was perfused for 2 h through the upper portion of the small intestine of ferrets. the effluent of a mesenteric lymph duct cannulation was collected, as well as intestinal mucosa scrapings, a portal blood sample, and a liver biopsy, both before and after perfusion. carotenoids and retinoids were m ... | 1995 | 7666004 |
| the fate of the skin graft in laryngoplasty. | in laryngoplasty procedures, laryngotracheal soft tissue defects are often repaired using skin grafts. while stenting is necessary to approximate and immobilize the graft, prolonged stenting causes increased bacterial counts, granulation tissue formation, tissue ischemia, and graft failure. optimal time for stent removal has not been experimentally defined. using the ferret animal model, 24 laryngoplasty procedures were performed. the subjects were stented by group for 0, 3, 7, 14, or 28 days. a ... | 1995 | 7666731 |
| seasonal fiber growth cycles of ferrets (mustela putorius furo) and long-term effects of melatonin treatment. | pelage cycles of ferrets are poorly documented, although it is clear that their timing is sensitive to daylength, mediated by pineal melatonin. hair follicles were monitored histologically in ferrets from 3 to 19 months of age in order to describe naturally occurring changes in follicle growth status and follicle number over three successive cycles of fur growth. melatonin was administered to some of these animals in late summer to determine the long-term effects of perturbation of hormonal cont ... | 1995 | 7673877 |
| acetylcholine and adenosine activate the g protein-gated muscarinic k+ channel in ferret ventricular myocytes. | the properties of the k+ channel activated by acetylcholine (ach) and adenosine (ado) were examined in single ferret ventricular myocytes using patch-clamp techniques. in the whole-cell configuration, ach and ado induced an inwardly rectifying k+ current and shortened the action potential duration. the effect of ach was blocked by atropine, while the ado effect was interrupted by 8-cyclopentyl,1,2-dipropyl xanthine, a specific ado a1 receptor antagonist. in cell-attached recordings, ach and ado ... | 1995 | 7675119 |
| ferret tracheal mucus rheology, clearability and volume following administration of substance p or methacholine. | we studied the effects of substances p administration on tracheal mucus viscoelasticity, water content, clearability and secretion rate. six neutered adult male ferrets (weight 1.1-1.5 kg) were studied, on four occasions each. they were anaesthetized with ketamine and xylazine, and intubated shallowly. control mucus (pre- and post-ringer instillation) was compared with the mucus obtained following instillation of 200 microliters of 10(-6), 10(-5), and 10(-4) m substance p (sp), and 10(-4) m meth ... | 1993 | 7678818 |
| trigeminal nuclear complex of the ferret: anatomical and immunohistochemical studies. | in order to establish the ferret as an animal model for studies of trigeminal pain, we describe the cytoarchitecture and neurochemistry of the trigeminal nuclear complex in the ferret and compare them to those of the cat and rat. the complex was divided as previously described, but the ferret differed in the extent of the nuclear boundaries. the neuroanatomical istribution of substance p-, calcitonin gene-related peptide-, galanin-, enkephalin-, serotonin-, somatostatin-, neuropeptide y-, and ne ... | 1993 | 7681453 |
| tachykinin control of ferret airways: mucus secretion, bronchoconstriction and receptor mapping. | the effects of synthetic tachykinin receptor agonists on mucus secretion by ferret trachea was determined in vitro in ussing chambers using 35so4 as a mucus marker and the synthetic peptides [sar9,met(o2)11]substance p (sarsp), [beta ala8]neurokinin a-(4-10) and [mephe7] neurokinin b which are selective for nk1, nk2 and nk3 tachykinin-receptors respectively. the bronchomotor effects of the same agonists were also studied in vitro and tachykinin receptors were localized by autoradiographic mappin ... | 1993 | 7681552 |
| cervical chordoma in two ferrets (mustela putorius furo). | | 1993 | 7682370 |
| aleutian disease in domestic ferrets: diagnostic findings and survey results. | aleutian disease was diagnosed as the cause of posterior ataxia and paresis in domestic ferrets. six serologically positive animals (four clinically affected and two unaffected) were investigated in detail and seven other clinically affected ferrets were also identified. the diagnostic findings included hypergammaglobulinaemia, histological lesions in the central nervous system and parvovirus-like particles in mesenteric lymph nodes. a wider serological survey of 446 animals owned by members of ... | 1993 | 7685128 |
| the central localization of the vagus nerve in the ferret (mustela putorius furo) and the mink (mustela vison). | the location of vagal preganglionic neurones (vpn) has been determined in nine ferrets (mustela putorius furo) and seven mink (m. vison) using neuronal tract-tracing techniques employing horseradish peroxidase (hrp) and wheat-germ agglutinin conjugated hrp (wga-hrp) mixtures injected into the nodose ganglion of the vagus nerve. labelled vpn were located ipsilaterally in the dorsal motor nucleus of the vagus (dmnx), nucleus ambiguus (na), and reticular formation (rf) of the medulla oblongata. in ... | 1993 | 7686926 |
| colocalization of vasoactive intestinal peptide and nitric oxide synthase in neurons of the ferret trachea. | neurally-mediated relaxation of smooth muscle in human, guinea-pig, cat, and pig airways is largely attributed to a nonadrenergic, noncholinergic mechanism. while the specific transmitter(s) of this relaxant system have not been conclusively identified, vasoactive intestinal peptide and nitric oxide have emerged as likely mediators in airway smooth muscle. both vasoactive intestinal peptide and nitric oxide relax guinea-pig, pig and human smooth muscle. vasoactive intestinal peptide is present i ... | 1993 | 7688104 |
| photostimulation using caged glutamate reveals functional circuitry in living brain slices. | an approach for high-spatial-resolution mapping of functional circuitry in living mammalian brain slices has been developed. the locations of neurons making functional synaptic connections to a single neuron are revealed by photostimulation of highly restricted areas of the slice (50-100 microns in diameter) while maintaining a whole-cell recording of the neuron of interest. photostimulation is achieved by bathing brain slices in a molecularly caged form of the neurotransmitter glutamate [l-glut ... | 1993 | 7689225 |
| characterization of tachykinin receptors in ferret trachea by peptide agonists and nonpeptide antagonists. | the tachykinin receptors mediating mucus secretion and smooth muscle contraction were studied in the ferret trachea in vitro. substance p (sp) and the selective agonist for nk1 receptor ([sar9,met(o2)11]sp), but not selective agonists for nk2 ([ala5,beta-ala8]neurokinin a-(4-10)) and nk3 ([mephe7]neurokinin b) receptors, induced secretion of macromolecules in a concentration-dependent fashion. the nonpeptide nk1 receptor antagonist, cp-96,345, but not the nonpeptide nk2 receptor antagonist, sr-4 ... | 1993 | 7690189 |
| comparison of muscle cell fiber types and oxidative capacity in gracilis, rectus femoris, and triceps brachii muscles in the ferret (mustela putorius furo) and the domestic dog (canis familiaris). | muscle cell fiber types in gracilis, rectus femoris, and long head of triceps brachii muscles of ferrets and dogs were identified on serial sections stained for myosin atpase after preincubation at ph values of 9.8, 4.6, and 4.3 and for nadh-tetrazolium reductase (nadh-tr) activity. although fiber types i and ii were identified, the atpase stain did not demonstrate classic type iia/iib fiber differences in either species. however, two type ii fiber subtypes could be distinguished in the ferret b ... | 1993 | 7691036 |
| regional content of enteric substance p and vasoactive intestinal peptide during intestinal inflammation in the parasitized ferret. | our aim was to characterize and quantitate changes in two key neuropeptides, substance p (sp) and vasoactive intestinal peptide (vip), that are involved in governing neurally-mediated gastrointestinal (gi) reflex activity during enteric inflammation in the ferret. neuropeptide content was determined by radioimmunoassay of extracts of jejunal, ileal and colonic muscularis externa from uninfected ferrets and ferrets infected with enteric stages of the parasitic nematode, trichinella spiralis. incr ... | 1993 | 7692345 |
| endothelin-1 does not alter ca2+ responsiveness in saponin-skinned ferret papillary muscles. | endothelin is a potent vasoconstrictor and a positive inotropic agent in myocardium. endothelin has been reported to increase myocardial contractility with little or no increase in intracellular ca2+, thus apparently enhancing myofilament responsiveness to ca2+. we investigated the effects of endothelin on tension development and ca2+ responsiveness in both intact and saponin-skinned ferret right ventricular papillary muscles. isolated ferret papillary muscles were stimulated for 2 h in the pres ... | 1994 | 7698185 |
| sarcoplasmic reticulum function in newborn ferret cremaster skeletal muscles. | a study of the properties of the sarcoplasmic reticulum was performed with newborn ferret cremaster muscles at two different development stages: at 8 and 21 days. the effects of extracellular ca2+, caffeine and cyclopiazonic acid, a specific sarcoplasmic reticulum ca(2+)-atpase inhibitor, were examined on intact cremaster skeletal muscles. the uptake and release of ca2+ were explored on saponin-skinned fibres with or without cyclopiazonic acid and some results obtained were compared with those o ... | 1994 | 7698197 |
| in defense of ferrets. | | 1994 | 7698914 |
| otologic and systemic manifestations of experimental influenza a virus infection in the ferret. | in an effort to further validate an animal model and to better define the mechanisms relating viral upper respiratory tract infections and acute otitis media, we infected 10 ferrets intranasally with influenza a virus. infection was monitored by cultures and antibody titers, illness was monitored by signs and temperatures, and otologic complications were monitored by otoscopy, tympanometry, and eustachian tube function testing. all animals became infected. forced-response test results showed pro ... | 1995 | 7700664 |
| effect of high fat diet on liver microsomal oxygenations in ferret. | 1. ferret on a high fat diet accumulated large amounts of fat in its liver and had blood acetoacetate and beta-hydroxybutyrate concentrations 250 and 375% of those in control animals. 2. the high fat diet alone increased ferret liver microsomal 7-ethoxyresorufin o-deethylase (erod) activity by 90%, but had no effect on 7-methoxy-, 7-pentoxy-, or 7-benzyloxy-resorufin, o-dealkylase activities. administration of 3-methylcholanthrene (mc) increased only liver erod activity, by 5- to 6-fold, in ferr ... | 1994 | 7701848 |
| development of the pathway from the reticular and perireticular nuclei to the thalamus in ferrets: a dil study. | this study examines the connections of the thalamic reticular and perireticular cell groups in developing ferrets. small crystals of dil (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate) were implanted into either the dorsal thalamus or the cerebral cortex of aldehyde-fixed prenatal and postnatal ferret brains. a small implant of dil into the presumptive lateral geniculate nucleus during early prenatal development [between embryonic day 23 (e23) and e25] reveals many retrograd ... | 1994 | 7704297 |
| failure of aspirin to interfere with the cardioprotective effects of ifetroban. | the thromboxane receptor antagonist ifetroban ([1s-(1 alpha,2 alpha,3 alpha, 4 alpha)]-2-[[3-[4-[(pentylamino)carbonyl]-2-oxazolyl]- 7-oxabicyclo[2.2.1]hept-2-yl]methyl]benzenepropanoic acid) and aspirin were evaluated for direct and combined effects on myocardial infarct size in anesthetized ferrets subjected to coronary artery occlusion (90 min) and reperfusion (5 h). aspirin (10 mg/kg) or vehicle was administered as an i.v. bolus dose at the 45th min of occlusion in an initial assessment of i ... | 1994 | 7705447 |
| analysis of the retinas and optic nerves of achiasmatic belgian sheepdogs. | an autosomal recessive mutation carried in a family of black belgian sheepdogs eliminates the optic chiasm--all retinal ganglion cell axons extend directly into the ipsilateral optic tract. one key issue we are trying to resolve is whether the retina or the chiasm is the principal site of mutant gene action. in this study, we have examined retinas of mutants to discover any associated changes in retinal structure. retinas of mutant animals are relatively normal. inner and outer nuclear layers ar ... | 1995 | 7706558 |
| pathogenicity of influenza a/seal/mass/1/80 virus mutants for mammalian species. | increases in infectiousness, neurotropism and virulence were found in a laboratory variant of influenza a/seal/massachussets/1/80 (h7n7) virus having a highly cleavable hemagglutinin. sequential passage from host to host further increased pathogenicity of the h7n7 virus in mice, ferrets and rats. | 1995 | 7710359 |
| telencephalic and diencephalic origin of radial glial processes in the developing preoptic area/anterior hypothalamus. | neuronal birth-dating studies using [3h] thymidine have indicated that neurons in the preoptic area/anterior hypothalamus (poa/ah) are derived primarily from progenitors in proliferative zones surrounding the third ventricle. radial glial processes are potential guides for neuronal migration, and their presence and orientation during development may provide further information about the origin of cells in the poa/ah. in addition to determining the orientation of radial glial fibers, we examined ... | 1995 | 7714527 |
| cardiac electrophysiologic and antiarrhythmic actions of tedisamil. | the class iii electrophysiologic and antiarrhythmic actions of the bradycardic agent tedisamil were assessed in vitro and in vivo. in ferret isolated right ventricular papillary muscles, tedisamil increased effective refractory period (erp) in a concentration-dependent manner, with a 25% erp increase achieved with 3.0 microm tedisamil, and a 133.4% +/- 28.8% increase in erp achieved at the high 100 microm concentration tested. in anesthetized dogs, the cumulative i.v. administration of tedisamil ... | 1995 | 7714763 |
| dose-related cardioprotection by ifetroban in relation to inhibition of thrombosis and ex vivo platelet function. | the dose-related cardioprotective efficacy of the thromboxane a2/prostaglandin endoperoxide (tp) receptor antagonist, ifetroban (bms-180291), was investigated in an anesthetized ferret model of myocardial ischemia (90 min) followed by reperfusion (5 h). treatment was begun at either the 75th minute of ischemia or 5 min after initiating reperfusion. the magnitude of tp receptor blockade was evaluated by ex vivo platelet function. additional experiments in ferrets tested the antithrombotic potency ... | 1995 | 7716179 |
| cutaneous lymphoma in a ferret (mustela putorius furo). | | 1995 | 7725598 |
| biochemical, mechanical and energetic characterization of right ventricular hypertrophy in the ferret heart. | ferret right ventricular hypertrophy is characterized by a decreased and prolonged isometric contraction, associated with altered intracellular calcium (ca2+) regulation. however myofibrillar composition, cross-bridge function and/or energy transfer may also be involved in these contractile disturbances. therefore, mechanical properties of myofibrils have been studied with triton x-100-skinned fibres and troponin (tn) t and i composition has been examined. mitochondrial function and functional a ... | 1994 | 7731052 |
| variability in distribution and populations of gap junctions in ferret trachea during postnatal development. | immunocytochemical probes have been used to characterize gap junction distribution in the postnatal ferret trachea by epifluorescence and by laser scanning confocal and electron microscopy. a battery of antibodies directed against fragments of different connexins localized beta 1- and beta 2-gap junction antigens (connexins 32 and 26, respectively) at the intercellular borders of the superficial epithelium while alpha 1-gap junction antigen (connexin 43) was localized to the loose connective tis ... | 1995 | 7733300 |
| gastric disease in ferrets: effects of helicobacter mustelae, nitrosamines and reconstructive gastric surgery. | animal models are being used to study the mechanisms by which helicobacter spp. induce gastric disease. to assess the effects of a natural gastric pathogen, helicobacter mustelae, in the development of chronic gastritis, premalignancy and cancer, the ferret model was studied under natural and experimental conditions. | 1994 | 7735938 |
| responses of neurons in the ferret superior colliculus to the spatial location of tonal stimuli. | using multi-unit recordings, we compared the azimuthal spatial selectivity of auditory neurons in the deep layers of the ferret superior colliculus (sc) to broadband and tonal stimuli. responses to noise were tuned at different sound levels to a single location, which varied topographically along the rostrocaudal axis of the nucleus to form a map of sound azimuth. frequency response profiles tended to be multi-peaked, so the spatial tuning was examined at two or more frequencies in each case. so ... | 1994 | 7737921 |
| scaling of transepithelial potential difference in the mammalian trachea. | tracheal epithelia of different mammalian species differ widely with regard to the relative rates of na+ absorption and cl- secretion. however, the short circuit current, a measure of total ion transport, appears to be consistently greater in large than in small mammals. thus, we hypothesized that the in vivo tracheal electrical potential difference (pd) would vary among species as a function of body mass (m). to test this hypothesis we measured pd in ten mammalian species that ranged 1000-fold ... | 1995 | 7740208 |
| [rabies antibody production in ferrets after immunization with four different rabies vaccines]. | the development of rabies antibodies in ferrets after injection of four different types of rabies vaccines. experiments aimed at proving the suitability of ferrets in the routine testing of rabies vaccines for human and animal use were carried out. a total of 40 ferrets received four vaccines, two for use in humans and two for use in animals. for the determination of rabies antibodies, blood was taken on days 28 and 56, respectively, after inoculation of the vaccines. all animals developed antib ... | 1994 | 7740856 |
| evaluation of urinary cortisol:creatinine ratios for the diagnosis of hyperadrenocorticism associated with adrenal gland tumors in ferrets. | assays were validated for the measurement of urinary concentrations of cortisol and creatinine in domestic ferrets (mustela putorius furo). urinary concentrations of cortisol and creatinine and the calculated urinary cortisol:creatinine ratio (uccr) values were determined for 29 clinically normal female ferrets, 22 clinically normal male ferrets, and 12 ferrets with adrenal gland tumors. the uccr values for the 51 clinically normal ferrets ranged from 0.04 x 10(-6) to 1.66 x 10(-6), with a media ... | 1995 | 7744661 |
| transient expression of nadph-diaphorase in the lateral geniculate nucleus of the ferret during early postnatal development. | retinogeniculate projections in the ferret are refined during postnatal development so that inputs from the two eyes become segregated into eye-specific laminae, and each eye-specific lamina is further divided into sublaminae containing inputs from on-center or off-center afferents. segregation into eye-specific laminae and on/off sublaminae is dependent on neuronal activity; sublamination depends on activation of n-methyl-d-aspartate (nmda) receptors. by analogy with the suggested role of nitri ... | 1995 | 7745138 |
| plague in a black-footed ferret (mustela nigripes). | diagnosis of sylvatic plague in a captive black-footed ferret (mustela nigripes) was based on gross and microscopic lesions, fluorescent antibody tests, culture of yersinia pestis, and immunohistochemistry. gross lesions consisted of acute hemorrhage and necrosis associated with cervical and mesenteric lymph nodes, subcutaneous hemorrhages, and pulmonary edema. acute edema, hemorrhage, and necrosis with numerous bacteria in blood vessels and sinusoids characterized microscopic lesions. occurrenc ... | 1994 | 7760495 |
| effects of 5-ht3 receptor antagonists on models of acute and delayed emesis induced by cisplatin in the ferret. | the emetic profile of action of cisplatin 5 and 10 mg/kg i.p. was investigated in the ferret over a 72 and 24 hr period respectively. the 5-ht3 receptor antagonists ondansetron and alosetron markedly antagonized or abolished the emesis during the "acute phase" and, whilst antagonizing the emesis during the delayed phase, also revealed a 5-ht3 receptor antagonist resistant component. these cisplatin paradigms may provide models relevant to the study of acute and delayed emesis induced by cisplati ... | 1994 | 7760983 |
| depression of hepatic cytochrome p450 monooxygenases after chronic environmental tobacco smoke exposure of young ferrets. | six-week-old ferrets were exposed head-only to clean air or environmental tobacco smoke (ets) for 2 h/day, 5 days a week for a total of 8 weeks. exposure to ets caused a significant reduction in the levels of hepatic microsomal cytochrome p450 and p450 reductase activity in both the male and female ferrets. the content of cytochrome b5 and the activity of its reductase were significantly reduced in the hepatic microsomes of female ferrets. 7-ethoxycoumarin o-deethylase activity and cytochrome p4 ... | 1995 | 7762009 |
| fractional sr ca release is regulated by trigger ca and sr ca content in cardiac myocytes. | the release of sarcoplasmic reticulum (sr) ca in cardiac muscle during excitation-contraction coupling is known to be graded by the amount of activating ca outside the sr (i.e., ca-induced ca release). however, little is known about how intra-sr ca affects the release process. in this study we assessed how the fractional sr ca release as described by bassani et al. [am. j. physiol. 265 (cell physiol. 34): c533-c540, 1993] is affected by alteration of trigger ca and of sr ca content. experiments ... | 1995 | 7762626 |
| smooth muscle protein kinase c. | protein kinase c (pkc) was first implicated in the regulation of smooth muscle contraction with the observation that phorbol esters induce slowly developing, sustained contractions. in some vascular smooth muscles, e.g., ferret aorta, phorbol ester induced contractions occur without an increase in sarcoplasmic free-ca2+ concentration ([ca]i) or myosin light chain phosphorylation. this response appears to be mediated by a ca(2+)-independent isoenzyme of pkc (probably pkc epsilon), since saponin-p ... | 1994 | 7767884 |
| use of a vascular access system for administration of chemotherapeutic agents to a ferret with lymphoma. | two months after initiation of chemotherapy, a totally implantable vascular access system was used for the continuing administration of chemotherapeutic agents to a ferret with multicentric lymphoma. the subcutaneously located injection port minimized the need for restraint and facilitated repeated iv administration of drugs. treatment with a combination of l-asparaginase, vincristine sulfate, doxorubicin, cyclophosphamide, methotrexate, chlorambucil, and prednisone failed to induce complete rem ... | 1995 | 7768701 |
| comparative ultrastructural and functional studies of helicobacter pylori and helicobacter mustelae flagellin mutants: both flagellin subunits, flaa and flab, are necessary for full motility in helicobacter species. | helicobacter mustelae causes chronic gastritis and ulcer disease in ferrets. it is therefore considered an important animal model of human helicobacter pylori infection. high motility even in a viscous environment is one of the common virulence determinants of helicobacter species. their sheathed flagella contain a complex filament that is composed of two distinctly different flagellin subunits, flaa and flab, that are coexpressed in different amounts. here, we report the cloning and sequence de ... | 1995 | 7768796 |
| differential photoperiodic control of seasonal variations in pulsatile luteinizing hormone release in long-day (ferret) and short-day (mink) mammals. | the aim of this study was to elucidate the pituitary adjustments implicated in photoperiodic control of reproduction in two mammalian species, the ferret and the mink. in the ferret, which displays renewed testicular activity when the days lengthen, we observed a stimulation of the pulsatile liberation of luteinizing hormone (lh) reflecting the pulsatile activity of the gonadotropin-releasing hormone (gnrh) system when daylight was equal to or in excess of ld 8:16. this photoperiod coincides pre ... | 1994 | 7772791 |
| pharmacological characterization of rs 25259-197, a novel and selective 5-ht3 receptor antagonist, in vivo. | 1. the pharmacological effects in vivo, of rs 25259-197, a selective 5-ht3 receptor antagonist, have been investigated. 2. in anaesthetized rats, rs 25259-197, administered by the intravenous, intraduodenal or transdermal route, dose-dependently inhibited the von bezold-jarisch reflex induced by 2-methyl 5-ht (id50 = 0.04 micrograms kg-1, i.v., 3.2 micrograms kg-1, i.d. and 32.8 micrograms per chamber, respectively). in this regard, when administered intraduodenally, rs 25259-197 was more potent ... | 1995 | 7773547 |