| susceptibility of four species of copepods, from areas of endemic dracunculus medinensis, to the north american d. insignis. | studies of the relative importance of different copepod species in areas of endemic dracunculiasis have been restricted, in part, by limited access to dracunculus medinensis. however, development of the d. insignis-ferret model provides a source of larvae of a species closely related to d. medinensis. using larvae derived from this model, the susceptibility of four species of copepods from d. medinensis-endemic areas was compared to that of canadian acanthocyclops vernalis, which is fully suscep ... | 1991 | 1839817 |
| acute alterations in the regulation of lipid metabolism after intravascular reexposure to a single bolus of homologous virus during influenza b infection in ferrets: possible model of epiphenomena associated with influenza. | metabolic responses occurring 24 h following the secondary haematogenous dissemination of influenza b virus during convalescence from infection were examined in the ferret as a possible model for epiphenomena which can occur following infection with influenza. among the major changes found were a further rise in the mean fasting serum free fatty acid (ffa) level to three times the control mean value and a 50% drop in the mean serum triglyceride (tg) concentration after the intravascular administ ... | 1991 | 1843259 |
| estimation of intracellular free magnesium using ion-selective microelectrodes: evidence for an na/mg exchange mechanism in skeletal muscle. | mg-selective microelectrodes allow continuous direct recording of intracellular free magnesium concentration ([mg]i). mg-selective microelectrodes utilizing the neutral carrier eth 1117 have been used to determine [mg]i in a wide variety of tissues. however, this type of electrode suffers from considerable interference from other cations (primarily potassium and sodium when used for intracellular studies). the recently developed mg sensor eth 5214 reveals a much improved selectivity and sensitiv ... | 1991 | 1844563 |
| use of ion-sensitive microelectrodes to study intracellular free magnesium concentration and its regulation in mammalian cardiac muscle. | ion-sensitive microelectrodes (ises) have been used to measure intracellular [mg2+] ([mg2+]i) in cardiac muscle, although most measurements have tended to overestimate the value due to the poor selectivity of the mg2+ ionophore in the sarcoplasm and to inaccurate collation of individual ise measurements. this paper highlights the correct method for analysis of data from multiple ise experiments. since [mg2+]i is constrained at a lower concentration than would be expected by passive distribution ... | 1991 | 1844564 |
| intracellular ph regulation in ferret ventricular muscle. the role of na-h exchange and the influence of metabolic substrates. | aspects of ph regulation in ferret ventricular cells have been investigated by using ph- and sodium-selective microelectrodes in bicarbonate-free tyrode's solution. an acid load was produced by the transient application of nh4cl (10 or 20 mmol/l). a complete recovery from an acid load was still observed after multiple applications of nh4cl, but amiloride (0.75 or 1 mmol/l), a blocker of the na-h exchanger, increased the acidification and inhibited the recovery. measurements of intracellular sodi ... | 1991 | 1845852 |
| use of the ferret as a model for pediatric endotracheal intubation training. | | 1991 | 1849599 |
| flosequinan, a vasodilator with a novel mechanism of action. | 1. the mechanism of action of flosequinan was investigated in ferret aortic smooth muscle by the simultaneous measurement of aequorin luminescence and isometric force. 2. the control calcium-force curve was obtained by plotting the calibrated aequorin luminescence against the force from potassium-depolarized muscles. flosequinan relaxed potassium-depolarized muscles by causing parallel changes in [ca2+]i and force with no shift in the control [ca2+]i-force relationship. 3. the [ca2+]i-force rela ... | 1991 | 1855126 |
| effects of ozone on the cholinergic secretory responsiveness of ferret tracheal glands. | oxidant air pollutants exacerbate several pulmonary diseases. inhalation of ozone has been shown to induce airway smooth muscle hyperresponsiveness. oxidant injury could also affect airway secretory mechanisms. we postulated that oxidant exposure would alter the glycoconjugate secretory function of airway submucosal glands. to test this hypothesis we examined the effects of in vivo ozone exposure on the in vitro secretory responsiveness of ferret tracheal glands. ferrets were exposed to 1 ppm oz ... | 1991 | 1855492 |
| source of information in heart research 1978 and 1988. | several regulatory provisions have been introduced during the last decade that might interfere with the conduct of experimental medical science. in order to study their impact on the source of information within one major field, heart research, a total of 3579 abstracts from the 1978 and 1988 scientific sessions of the american heart association were analysed with respect to their source of information. there was no change in overall fractions of classical patient studies (45%) or experimental a ... | 1991 | 1857099 |
| na-ca exchange: evidence against a ping-pong mechanism and against a ca pool in ferret red blood cells. | to determine the mechanism of na-ca exchange, we estimated the ratio of maximum velocity to michaelis constant for extra-cellular ca by measuring the rate of ca uptake at very low extracellular ca. in a ping-pong mechanism, one set of sites alternatively transports ca and na. in a sequential mechanism, ca and na sites are both filled during part of the transport cycle. in each set of experiments, two intracellular na concentrations were studied. the ca uptake rate (at low ca) increased as na inc ... | 1991 | 1858856 |
| developmental changes in the ferret ileum during the postnatal period. | the development of the ferret ileum was studied in order to determine the pattern of morphological maturation during the postnatal period. in the newborn, intestinal villi were short, and lined by simple columnar enterocytes with striated borders and small vacuoles. at one week old, the equivalent cell had large vacuoles that were shown on tem to be related to a tubulovesicular system in the apical region of the cytoplasm. at two and three weeks old, the epithelial cells at the same site showed ... | 1991 | 1866123 |
| change of ca2+ requirement for myosin phosphorylation by prostaglandin f2 alpha. | the mechanism of contraction of vascular smooth muscle by prostaglandin f2 alpha (pgf2 alpha) was examined by simultaneous measurement of the intracellular ca2+ concentration [( ca2+]i), force, and myosin light-chain (mlc) phosphorylation in ferret aorta. in the presence of 2.5 mm extracellular ca2+, pgf2 alpha (10(-5)m) produced a tonic contraction with a transient spike in [ca2+]i, followed by a relatively small sustained increase in [ca2+]i (from a basal level of 2.32 +/- 0.07 x 10(-7) to 2.7 ... | 1991 | 1872370 |
| endothelin 1 enhances myofilament ca2+ responsiveness in aequorin-loaded ferret myocardium. | the influence of endothelin 1 on intracellular ca2+ transients and isometric contractions was investigated in ferret papillary muscles loaded with the ca(2+)-regulated bioluminescent indicator aequorin. in concentrations of 3 x 10(-9) to 1 x 10(-7) m, endothelin produced dose-dependent increases in the amplitudes of both aequorin light signals (maximum, 31 +/- 12%) and developed tension (maximum, 64 +/- 13%). the peak aequorin light [( ca2+]i)-peak tension curve generated by increasing endotheli ... | 1991 | 1873860 |
| cardiac cell membrane repolarization is required for onset of mechanical restitution in papillary muscle. | in 10 voltage clamped ferret papillary muscles at 37 degrees c (single sucrose gap), the duration of resting (diastolic, holding) potential was varied in order to define the mechanical restitution process. following a period of steady state voltage clamp depolarizations to +20 mv, a single test depolarization clamp of 200 or 500 ms duration was introduced. then, the following period at resting (holding) potential was varied. all the mechanical restitution curves for the 500 ms clamps were delaye ... | 1991 | 1877359 |
| pulmonary vascular pressure profile in adult ferrets: measurements in vivo and in isolated lungs. | we have determined the vascular pressure profile in lungs of adult ferrets utilizing an anaesthetized open chested preparation and have compared the pressure profile in vivo with that in isolated, perfused lungs. ten adult ferrets, mean body weight 980 +/- 108 g, were studied. for in vivo measurements, five ferrets were anaesthetized, mechanically ventilated and the left chest wall resected. pressures were measured in the pulmonary artery, left atrium and by micropuncture, in 20-50 microns diame ... | 1991 | 1877364 |
| comparative histogenesis of bruch's membrane (complexus basalis). | we documented the comparative histogenesis and timing of development of bruch's membrane (complexus basalis) in five mammalian models with different lengths of gestation. retinas with attached choroid from the central posterior pole of the eye were obtained from hamster, vole, rabbit, ferret and cat, from mid-gestation onward until the time at which all components of bruch's membrane could be detected. the sequence of events in the development of bruch's membrane was similar among species, howev ... | 1991 | 1879501 |
| purification and characterization of helicobacter mustelae urease. | helicobacter mustelae is a urease-rich bacterium associated with gastritis in ferrets. the ureases of h. mustelae and helicobacter pylori, a bacterium implicated in human gastritis, share many characteristics. helicobacter sp. ureases appear to be unique among bacterial enzymes in exhibiting submillimolar km values and in being composed of two subunits. | 1991 | 1879950 |
| evaluation of campylobacter jejuni colonization of the domestic ferret intestine as a model of proliferative colitis. | forty 3- to 17-week old domestic ferrets, including 2 gnotobiotes, were inoculated orally and/or rectally with 10(6) to 10(9) colony-forming units of 1 or more of 4 strains of campylobacter jejuni, 3 of mink and 1 of human origin. feeding or gavage of any of the 4 strains, in milk or broth, with or without preinoculation sodium bicarbonate treatment to neutralize stomach acid, induced colonization in 38/40 ferrets; diarrhea lasted 2 to 4 days in conventional kits, 6 days in gnotobiotes. bacterem ... | 1991 | 1883085 |
| the effect of acidosis on the interval-force relation and mechanical restitution in ferret papillary muscle. | 1. the effect of a respiratory acidosis on the interval-force relation and on mechanical restitution was investigated in ferret papillary muscles. 2. acidosis (ph 6.85) decreased developed force over a range of stimulation frequencies (1.0.06 hz); the percentage decrease was greatest at the lowest stimulation frequencies. qualitatively similar effects of acidosis on developed force were observed in the presence of the sarcoplasmic reticulum (sr) inhibitor ryanodine. 3. mechanical restitution cur ... | 1991 | 1886064 |
| mn and cd transport by the na-ca exchanger of ferret red blood cells. | ca influx via the na-ca exchanger into ferret red blood cells is easily measured from a na-free solution; the intracellular na concentration is normally approximately 150 mm in ferret red blood cells. we have found that mn and cd competitively inhibit ca influx. mn influx and cd influx were a saturable function of the divalent cation concentration, consistent with a carrier mechanism. indeed, the km (approximately 10 microm) and the vmax (usually 1-3 mmol.l packed cells-1.h-1) were similar for c ... | 1991 | 1887874 |
| atropine-resistant submandibular responses to stimulation of the parasympathetic innervation in the anaesthetized ferret. | 1. submandibular salivary and vascular responses to stimulation of the peripheral end of the chorda-lingual nerve at 20 hz continuously for 60 min were investigated in anaesthetized ferrets, in which the sympathetic innervation to the gland was cut, in the presence and absence of atropine (2.0 mg kg-1). 2. both the increase in submandibular salivary flow and protein output, which occurred in response to nerve stimulation, were substantially reduced following the administration of atropine, the l ... | 1991 | 1890638 |
| the effects of metabolism on na(+)-k(+)-cl- co-transport in ferret red cells. | 1. the effects of altering metabolism on na(+)-k(+)-cl- co-transport were studied in ferret red cells. na(+)-k(+)-cl- co-transport was measured as the bumetanide-sensitive uptake of 86rb. 2. glucose, but not inosine or adenosine, sustained metabolism and maintained cell atp content ([atp]i) at the physiological level. [atp]i could be reduced by prolonged incubation of cells in a substrate-free medium or more quickly by incubating cells with 2-deoxyglucose or with a mixture of iodoacetamide and g ... | 1991 | 1890646 |
| characterization of eugonic fermenters group ef-4 by polyacrylamide gel electrophoresis and protein immunoblot analysis. | whole-cell lysates and proteinase k-extracted lipopolysaccharide (lps) of 19 strains of the group eugonic fermenter-4 (ef-4) were analyzed by electrophoresis and protein immunoblotting. these strains were isolated from dog- and cat-bite abscesses in human beings, ferret and human gastric lesions, and cat-lung infections. these strains represent 2 biovar groupings; ef-4a biovars ferment glucose and possess arginine dihydrolase activity, whereas ef-4b biovars do not. electrophoresis of whole-cell ... | 1991 | 1892260 |
| ferret tracheal epithelial cells grown in vitro are resistant to lethal injury by activated neutrophils. | airway inflammation is often accompanied by accumulation of polymorphonuclear leukocytes (pmn) as well as epithelial sloughing. to determine whether pmn contribute to epithelial damage in inflammatory states, we examined the interaction of pmn and tracheal epithelial cells in culture. ferret tracheal epithelial (fte) cells were grown in primary culture on collagen-coated multiwell dishes. confluent monolayers were loaded with [51cr]o4 and exposed to resting and activated neutrophils. there was n ... | 1991 | 1892642 |
| enzymatic conversion of beta-carotene into beta-apo-carotenals and retinoids by human, monkey, ferret, and rat tissues. | whether the conversion of beta-carotene into retinoids involves an enzymatic excentric cleavage mechanism was examined in vitro with homogenates prepared from human, monkey, ferret, and rat tissue. using high-performance liquid chromatography, significant amounts of beta-apo-12'-, -10'-, and -8'-carotenals, retinal, and retinoic acid were found after incubation of intestinal homogenates of the four different species with beta-carotene in the presence of nad+ and dithiothreitol. no beta-apo-carot ... | 1991 | 1899329 |
| amiloride delays the ischemia-induced rise in cytosolic free calcium. | an increase in cytosolic free calcium (cai) has been shown to occur early during ischemia in perfused rat, ferret, and rabbit hearts. it has been proposed that this increase in cai may occur as a result of exchange of nai for cao, which occurs as a result of an increase in nai arising from exchange of nao for h+i. the latter exchange is stimulated by the intracellular acidification that occurs during ischemia. to test this hypothesis, we examined cai, nai, atp, and phi during ischemia in rats in ... | 1991 | 1902148 |
| analysis of 23na nmr spectra from isolated perfused hearts. | the 23na nmr spectra obtained from isolated hearts perfused with buffer containing the paramagnetic shift reagent dysprosium triethylenetetraminehexaacetic acid, dy(ttha)3-, are complex and contain a number of overlapping peaks of different intensities. spectra from rat, rabbit, guinea pig, and ferret hearts obtained during periods of control perfusion are similar and undergo similar changes when the hearts are subjected to periods of ischemia and reflow. the contributions from the intracellular ... | 1991 | 1905777 |
| atp-dependent k+ channels modulate vasoconstrictor responses to severe hypoxia in isolated ferret lungs. | in normo- and hypoglycemic ferret lungs, the pulmonary vascular response to severe hypoxia (pio2 less than or equal to 10 mmhg) is characterized by an initial intense vasoconstriction followed by marked vasodilation, whereas in hyperglycemic lungs, vasodilation is minimal, causing vasoconstriction to be sustained. in contrast, the response to moderate hypoxia is characterized by a slowly developing sustained vasoconstriction which is unaffected by glucose concentration. to determine the role of ... | 1991 | 1907614 |
| characterization of beta-apo-13-carotenone and beta-apo-14'-carotenal as enzymatic products of the excentric cleavage of beta-carotene. | two new products from the incubation of beta-carotene with intestinal mucosa homogenates of human, monkey, ferret, and rat were isolated using high-performance liquid chromatography (hplc). identification by comparing retention times in hplc, by monitoring ultraviolet/visible spectra, by reduction to corresponding alcohol, by oxime formation, and by mass spectrometry demonstrated that they are beta-apo-13-carotenone and beta-apo-14'-carotenal. these compounds were not found in incubations done w ... | 1991 | 1911774 |
| pituitary adenylate cyclase-activating peptide (pacap), a new vasoactive intestinal peptide (vip)-like peptide in the respiratory tract. | pituitary adenylate cyclase-activating peptide (pacap) is a vasoactive intestinal peptide (vip)-like peptide recently isolated from ovine hypothalami. nerve fibers displaying pacap immunoreactivity were found in the respiratory tract of rats, guinea pigs, ferrets, pigs, sheep and squirrel monkeys. a moderate supply of pacap-immunoreactive fibers was seen in the nasal mucosa of guinea pigs. few to moderate numbers of pacap-containing fibers occurred in the tracheo-bronchial wall of rats, guinea p ... | 1991 | 1913779 |
| pancreatic adenocarcinoma with osseous metaplasia in a ferret. | a poorly differentiated pancreatic adenocarcinoma with regional lymphatic, hepatic, enteric and pulmonary metastases was diagnosed in an adult european ferret (mustela putoris furo). the ferret showed clinical signs including a progressive, marked abdominal enlargement owing to ascites. microscopic findings included intralesional osseous metaplasia. exocrine pancreatic neoplasms in ferrets are rarely reported compared with neoplasms with endocrine differentiation. | 1991 | 1918450 |
| morphology of pioneer and follower growth cones in the developing cerebral cortex. | in the developing nervous systems of both invertebrates and vertebrates, neurons must develop precise sets of axonal connections. one strategy used by both orders of animals is to generate a special class of neurons whose axons "pioneer" the first pathways between these cells and their targets. in the developing mammalian telencephalon, the subplate neurons (which are among the first neurons to be generated in development) extend axons to long-distance subcortical targets before the neurons of t ... | 1991 | 1919567 |
| experimental infection of domestic ferrets (mustela putorius furo) and siberian polecats (mustela eversmanni) with yersinia pestis. | eight domestic ferrets (mustela putorius furo) and two siberian polecats (m. eversmanni) were inoculated subcutaneously with 12 to 1.2 x 10(7) yersinia pestis originally isolated during an epizootic of plague in white-tailed prairie dogs (cynomys leucurus) near meeteetse, park county, wyoming (usa) in 1985. none of the ferrets or polecats developed clinical signs of disease which suggested that black-footed ferrets (m. nigripes), a congener, also would be resistant to plague. all animals receivi ... | 1991 | 1920664 |
| characterization of strains of helicobacter pylori: one-dimensional sds-page as a molecular epidemiologic tool. | one-dimensional linear sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total proteins, coupled with a computerized numerical analysis, was used to distinguish among strains of helicobacter pylori. one hundred seventy-five clinical strains and five reference strains of h. pylori from humans, four isolates of helicobacter mustelae from ferrets, and three isolates of h. pylori-like organisms (hplos) from miniature swine were examined. intraspecies and interspecies comparisons were made ... | 1991 | 1925314 |
| effect of in vivo inhibition of neutrophil adherence on skeletal muscle function during ischemia in ferrets. | neutrophils are reported to play an important role in the genesis of tissue damage during reperfusion after periods of ischemia in a variety of organs and may also be involved in loss of tissue function during ischemia. to test this hypothesis, the monoclonal antibody, moab 60.3, which prevents the adhesion of ferret neutrophils to cultured human endothelial cells at a concentration of 30 micrograms/ml, was tested in a model of peripheral vascular disease to determine whether it would preserve s ... | 1991 | 1928400 |
| emd 53998 sensitizes the contractile proteins to calcium in intact ferret ventricular muscle. | emd 53998 (a thiadiazinone) is an inotropic drug that produces a pronounced increase in the ca2+ sensitivity of the contractile proteins in skinned cardiac fibers. the present study was undertaken to determine whether this effect on ca2+ sensitivity could explain the increase in tension observed in intact ventricular muscle. the experiments were performed on isolated ferret papillary muscles that had been microinjected with aequorin to measure the intracellular ca2+ concentration. force and intr ... | 1991 | 1934345 |
| contractile deactivation and uncoupling of crossbridges. effects of 2,3-butanedione monoxime on mammalian myocardium. | we investigated the effects of 1 and 3 mm 2,3-butanedione monoxime (bdm, diacetyl monoxime) on excitation and contraction of cardiac muscle in several types of preparations at various levels of organization. we selected a concentration of bdm that was not expected to affect sarcolemmal calcium flux and action potential duration in cardiac tissue. two indicators were used to record intracellular calcium. aequorin, a bioluminescent calcium indicator, was used in studies with ferret papillary muscl ... | 1991 | 1934358 |
| virulence of rimantadine-resistant human influenza a (h3n2) viruses in ferrets. | the influence of rimantadine-resistance mutations on the virulence of human h3n2 viruses in ferrets was examined. the similarities in virulence of the drug-resistant mutants with single amino acid substitutions at three different locations, 27, 30, and 31, within the m2 sequence and their corresponding sensitive wild-type isolates contrasted with differences in virulence between the three pairs of viruses. these data provide further evidence that rimantadine-resistant viruses that emerge during ... | 1991 | 1940477 |
| pathophysiology and pathogenesis of contractile failure in stunned myocardium. | to investigate excitation-contraction coupling in stunned myocardium, intracellular free calcium concentration [( ca2+]i) was measured before and after ischemia in perfused hearts using gated 19f nmr and the ca2+ indicator 5f-bapta. maximal ca(2+)-activated force was also measured in parallel experiments. stunned myocardium was created by reperfusion after 15 min global ischemia at 37 degrees c in isolated ferret hearts. in stunned myocardium, peak [ca2+]i was paradoxically higher than that in c ... | 1991 | 1942493 |
| dominant-negative mutants as antiviral agents: simultaneous infection with the cold-adapted live-virus vaccine for influenza a protects ferrets from disease produced by wild-type influenza a. | the attenuated cold-adapted strain of influenza a virus that is a candidate live-virus vaccine suppressed clinical disease in ferrets when given simultaneously with a virulent epidemic strain of influenza a virus. the cold-adapted virus effectively prevented disease, even when the epidemic strain was of a different subtype than the attenuated virus. in this case, ferrets given a mixed inoculum produced antibody to both subtypes in the absence of clinical disease, indicating that both viruses are ... | 1991 | 1955719 |
| delayed neurotoxic effects of bis (1-methylethyl) phosphorofluoridate (dfp) in the european ferret: a possible mammalian model for organophosphorus-induced delayed neurotoxicity. | this study examined the effects of the organophosphorus delayed neurotoxicant bis (1-methylethyl) phosphorofluoridate (dfp) on the central nervous system of the european ferret. animals received subcutaneous injections of either 2 or 4 mg dfp/kg b.w. the extent of neuropathology was determined by the fink-heimer method, the activities of neuropathy target esterase (nte) and cholinesterase (che) by enzyme assay methods, and the severity of clinical signs by a graded scale. in ferrets injected wit ... | 1991 | 1956582 |
| immunocytochemistry of pancreatic endocrine tumors in three domestic ferrets (mustela putorius furo). | | 1990 | 1972304 |
| the actions of fenfluramine and interaction with 5-ht3 receptor-antagonists to inhibit emesis in the ferret. | the racemate and (+)- and (-)-isomers of fenfluramine (5 mg kg-1 i.p., 1 h pretreatment) antagonized cisplatin-induced retching and vomiting in the ferret. the intravenous injection of (+/-)-fenfluramine administered on an established cisplatin-induced emesis antagonized the response within minutes of injection. the administration of a lower dose of (+/-)-fenfluramine (1.0 mg kg-1 i.p., 1 h pretreatment) failed to antagonize cisplatin-induced emesis when administered alone but enhanced the antie ... | 1990 | 1972409 |
| fluphenazine, ics 205-930 and dl-fenfluramine differentially antagonise drug-induced emesis in the ferret. | the intravenous injection of cisplatin (10 mg/kg), the subcutaneous injection of apomorphine (0.125-1 mg/kg) and lisuride (0.001-0.1 mg/kg), the oral administration of ipecacuanha (0.3-2.4 mg/kg) and the intragastric administration of copper sulphate (25-100 mg/kg), induced a vomiting and retching response in the ferret. pretreatment with dl-fenfluramine (5 mg/kg i.p.) prevented or reduced the emesis induced by cisplatin, apomorphine, ipecacuanha and lisuride but failed to significantly antagoni ... | 1990 | 1972549 |
| the ferret as a model for studying the sexual differentiation of behavioral and reproductive function. | | 1990 | 1974798 |
| exacerbation of bacterial toxicity to infant ferrets by influenza virus: possible role in sudden infant death syndrome. | of several toxins examined, only staphylococcal alpha and gamma toxin, endotoxin, and diphtheria toxins were lethal for 5-day-old ferrets. their toxicities were enhanced in animals infected at 1 day old with influenza virus, from 3-fold with staphylococcal gamma toxin through 14-fold for staphylococcal alpha toxin, 84-fold for endotoxin, and 219-fold for diphtheria toxin. no increased viral replication occurred in any tissue; thus the effects of the toxins were exacerbated by the infection, not ... | 1991 | 1984474 |
| mechanism of early ischemic contractile failure. inexcitability, metabolite accumulation, or vascular collapse? | the basis of early ischemic contractile failure was investigated in perfused ferret hearts at 27 degrees c. isovolumic left ventricular developed pressure fell by more than 50% within 30 seconds of the onset of total global ischemia and reached zero by 5 minutes. monophasic action potential recordings revealed no decrease in excitability during this period. phosphorus nuclear magnetic resonance spectra obtained at 30-second resolution showed no significant changes in inorganic phosphate or phosp ... | 1991 | 1984866 |
| mechanical alternans during acidosis in ferret heart muscle. | acidosis leads to mechanical alternans (i.e., alternation of large and small contractions) in ferret papillary muscles. this alternation in the size of the contraction is paralleled by alternation in the size of the intracellular ca2+ transient (monitored using the photoprotein aequorin). in isolated myocytes, the large contraction is accompanied by a prolonged action potential. mechanical alternans also can be induced by acidosis in isolated myocytes during a train of voltage-clamp pulses. thus ... | 1991 | 1984873 |
| attachment of influenza a virus to ferret tracheal epithelium at different maturational stages. | influenza virus attaches primarily to ciliated cells in mature airways epithelium. this process is mediated by a viral envelope glycoprotein (hemagglutinin) that binds to sialic acid-containing receptors in the apical membrane of host cells. the purpose of this study was to determine the cellular distribution of these receptors as a function of tracheal epithelial maturation in the ferret, which is susceptible to influenza virus infection at all ages and undergoes postnatal ciliation. to assay f ... | 1991 | 1986780 |
| influenza virus enhancement of membrane leakiness induced by staphylococcal alpha toxin, diphtheria toxin and streptolysin s. | release of alpha-amino[14c]isobutyric acid from ferret mpf cells was promoted by staphylococcal alpha toxin, diphtheria toxin and streptolysin s. this release was enhanced to a significant extent if the cells had been previously infected with influenza virus strain a/puerto rico/8/34 (pr8, h1n1), although infection with virus alone did not increase the release of radiolabel as compared with that from untreated cells; inactivated virus had a similar enhancing action. the mechanism of enhancement ... | 1991 | 1990059 |
| the effects of halothane, enflurane, and isoflurane on the length-tension relation of the isolated ventricular papillary muscle of the ferret. | the effects of halothane, enflurane, and isoflurane on the length-tension relation were investigated in papillary muscles of the right ventricle of adult male ferrets at 30 degrees c. isometric twitch contractions were obtained at lengths ranging from the shortest length yielding the greatest active force development under isometric conditions (lmax) to 86% of lmax, in two consecutive protocols: first in [ca2+]o ranging from 0.45 to 2.25 mm, and then in [ca2+]o 2.25 mm before, during, and after ... | 1991 | 1990903 |
| intracellular po2 in individual cardiac myocytes in dogs, cats, rabbits, ferrets, and rats. | myoglobin (mb) saturation in individual subepicardial myocytes was determined by cryospectroscopy in dogs, cats, ferrets, rabbits, and rats. mb saturation within 800 microns of the epicardium is not affected by quick freezing or absorption of light by cytochromes. the po2 in equilibrium with mb (pmbo2) was calculated from the mb oxydissociation curve. the minimum pmbo2 found among the 1,000 cells examined was 2.5 torr, at least five times the critical po2 for cytochrome turnover in myocardium. t ... | 1991 | 1996695 |
| differential regulation of brain aromatase by androgen in adult and fetal ferrets. | the contribution of androgens to the regulation of aromatase activity (aa), measured by quantifying the in vitro formation of [3h]estrone from 19-[3h]hydroxyandrostenedione precursor, was studied in equivalent microdissected brain regions of adult and fetal ferrets. in adulthood, aa was similar in the bed nucleus of the stria terminalis, medial (m) and lateral (l) preoptic area (poa), medial (ma) and lateral amygdala (la), ventromedial hypothalamus (vmh), and parietal cortex of gonadectomized ma ... | 1991 | 1999145 |
| method for studying arterial wave transmission effects on left ventricular function. | a technique for studying the real-time effects of arterial wave reflections on the performance of the isolated left ventricle was investigated. real-time arterial loading of an isolated ferret heart with an asymmetric t-tube wave transmission model was obtained with the use of a multiprocessor computer control system and a volume control linear motor pump. the multiprocessor computer system was programmed to compute the instantaneous aortic flow from the instantaneous ventricular pressure. the t ... | 1991 | 2000959 |
| tetrodotoxin does not block the epithelium-dependent release of prostaglandin e2 induced by electrical field stimulation in isolated ferret trachea. | electrical field stimulation (efs) has previously been shown to induce the release of prostaglandin (pg) e2 from ferret tracheal epithelium. we have now conducted a study to see whether this effect of efs is due to the activation of nerves or whether it is a non-neural effect. the release of pge2 and 6-keto-pgf1 alpha into the bath fluid was assayed in isolated ferret tracheas with (e+) or without (e-) epithelium, stimulated by either efs or direct vagal nerve stimulation (dns) repeatedly for 12 ... | 1991 | 2001290 |
| nature of the endogenous pyrogen (ep) induced by influenza viruses: lack of correlation between ep levels and content of the known pyrogenic cytokines, interleukin 1, interleukin 6 and tumour necrosis factor. | fever in influenza results from the release of endogenous pyrogen (ep) following virus-phagocyte interaction and its level correlates with the differing virulence of virus strains. however, the different levels of fever produced in ferrets by intracardial inoculation of ep obtained from the interaction of different virus strains with ferret of human phagocytes did not correlate with the levels of interleukin 1 (il-1), il-6 or tumour necrosis factor in the same samples as assayed by conventional ... | 1991 | 2005436 |
| effects of glucose on hypoxic vasoconstriction in isolated ferret lungs. | to characterize the effects of glucose on the pulmonary vascular response to anoxia and hypoxia, isolated ferret lungs were ventilated with 28% o2 and 5% co2 and perfused at constant flow (100 ml.kg-1.min-1). perfusate glucose concentrations were allowed to fall spontaneously to less than 1 mm (low glucose) or were controlled at 5-6 mm (normal glucose) or 12-17 mm (high glucose). at 60, 120, and 180 min of perfusion, the inspired o2 tension (pio2) was reduced to 0, 10, or 30 torr for 30 min, and ... | 1991 | 2010403 |
| effects of cocaine on excitation-contraction coupling of aortic smooth muscle from the ferret. | the mechanism by which cocaine alters vascular tone is not fully understood. we determined the effects of cocaine on excitation-contraction coupling of isolated ferret aorta. cocaine in concentrations less than or equal to 10(-4) m caused a contractile response in a dose-dependent manner. the response of control muscle was significantly larger than that in muscle from ferrets pretreated with reserpine. cocaine-induced contraction was not affected by endothelial factors, but was significantly inh ... | 1991 | 2010545 |
| intracellular calcium and ventricular fibrillation. studies in the aequorin-loaded isovolumic ferret heart. | to elucidate the role of changes in [ca2+]i in the induction of ventricular fibrillation (vf), ca2+i signals, epicardial electrical potentials, and isovolumic left ventricular pressure were simultaneously recorded in isolated intact ferret hearts loaded with aequorin, a bioluminescent protein. when the preparations were perfused with 3 microm acetylstrophanthidin and 8 mm ca2+, or with a low na+ solution (18 mm na+, 100 mm li+), spontaneous transitions to the vf state were consistently observed ... | 1991 | 2018996 |
| variable effects of soman on macromolecular secretion by ferret trachea. | the purpose of this study was to examine the effect of the anticholinesterase agent, soman, on macromolecular secretion by ferret trachea, in vitro. we mounted pieces of ferret trachea in ussing-type chambers. secreted sulfated macromolecules were radiolabeled by adding 500 microci of 35so4 to the submucosal medium and incubating for 17 hr. soman added to the submucosal side produced a concentration-dependent increase in radiolabeled macromolecular release with a maximal secretory response (mean ... | 1991 | 2019349 |
| mechanism of the positive inotropic effect of ketamine in isolated ferret ventricular papillary muscle. | ketamine is a cardiovascular stimulant through its sympathomimetic effects; however, its direct inotropic effect has been reported as positive in rat and negative in rabbit ventricular myocardium. this study reexamines the effect of ketamine on the contractile properties of mammalian ventricular myocardium. in isolated, electrically stimulated ferret right ventricular papillary muscles, the authors assessed the inotropic effect of ketamine (10(-6) m to 3 x 10(-4) m in 0.5 log m increments) alone ... | 1991 | 2021205 |
| relation of cortical cell orientation selectivity to alignment of receptive fields of the geniculocortical afferents that arborize within a single orientation column in ferret visual cortex. | neurons in the primary visual cortex of higher mammals are arranged in columns, and the neurons in each column respond best to light-dark borders of particular orientations. the basis of cortical cell orientation selectivity is not known. one possible mechanism would be for cortical cells to receive input from several lateral geniculate nucleus (lgn) neurons with receptive fields that are aligned in the visual field (hubel and wiesel, 1962). we have investigated the relationship between the arra ... | 1991 | 2027051 |
| the auditory periphery of the ferret: postnatal development of acoustic properties. | the development of the acoustics of the auditory periphery of the ferret was examined by measuring the spectral transfer functions (stfs) and the directional characteristics of the outer ears of animals ranging in age from postnatal day 32 (p32) to p54. using an impulse response technique the stfs were obtained from up to 250 locations throughout free space. the directional responses were calculated for frequencies between 1 khz and 30 khz. the low frequency roll-off of the stf decreased with in ... | 1991 | 2032961 |
| effects of nitrous oxide on contractility, relaxation and the intracellular calcium transient of isolated mammalian ventricular myocardium. | the effects of nitrous oxide on variables of contractility and relaxation were analyzed in isolated ferret right ventricular papillary muscles. each mechanical variable, in isometric, isotonic, and zero-load-clamped twitches, was compared to the average value of that variable in control conditions (50% nitrogen in oxygen), before and after equilibration with 20%, 30% and 50% nitrous oxide in 50% oxygen. nitrous oxide caused a concentration-dependent decrease in contractility under all loading co ... | 1991 | 2033523 |
| synchronous bursts of action potentials in ganglion cells of the developing mammalian retina. | the development of orderly connections in the mammalian visual system depends on action potentials in the optic nerve fibers, even before the retina receives visual input. in particular, it has been suggested that correlated firing of retinal ganglion cells in the same eye directs the segregation of their synaptic terminals into eye-specific layers within the lateral geniculate nucleus. such correlations in electrical activity were found by simultaneous recording of the extracellular action pote ... | 1991 | 2035024 |
| short-time-scale left ventricular systolic dynamics. evidence for a common mechanism in both left ventricular chamber and heart muscle mechanics. | based on the premise that short-time-scale, small-amplitude pressure/volume/outflow behavior of the left ventricular chamber was dominated by dynamic processes originating in cardiac myofilaments, a prototype model was built to predict pressure responses to volume perturbations. in the model, chamber pressure was taken to be the product of the number of generators in a pressure-bearing state and their average volumetric distortion, as in the muscle theory of a.f. huxley, in which force was equal ... | 1991 | 2036709 |
| helicobacter mustelae-induced gastritis and elevated gastric ph in the ferret (mustela putorius furo). | helicobacter mustelae has been cultured from the stomachs of ferrets with chronic gastritis; the lesions in the stomach have many of the same histological features seen in h. pylori gastritis in humans. to determine whether h. mustelae-negative ferrets with normal gastric mucosa were susceptible to colonization and whether gastritis developed after infection, four h. mustelae-negative ferrets treated with cimetidine were inoculated orally on two successive days with 3 ml (1.5 x 10(8) cfu) of h. ... | 1991 | 2037349 |
| oral immunization against helicobacter pylori. | helicobacter pylori, which has been associated with gastritis and duodenal ulcers, commonly chronically infects adults. eradication of this microorganism, which is difficult to achieve, results in normalization of gastritis and marked reduction in the relapse rate of duodenal ulcers. since eradication is difficult to achieve, prevention of initial colonization of the gastrointestinal tract may be a viable alternative for abrogation of h. pylori-associated gastroduodenal disease. to test the feas ... | 1991 | 2050403 |
| studies on the emetic and antiemetic properties of zacopride and its enantiomers. | in ferrets, the oral emetic activity of zacopride was compared with its r- and s-enantiomers. increasing doses of 0.01, 0.1, 1.0, 10.0 and 31.6 mg/kg of zacopride or its 2 enantiomers were each administered at hourly intervals to separate groups of animals until emesis occurred. the emetic (100%) dose for zacopride and its s-enantiomer was 0.11 mg/kg p.o. (cumulative dose). the r-enantiomer at a cumulative dose of 42.71 mg/kg p.o. produced emesis in 25% of the animals. by the i.p. route zacoprid ... | 1991 | 2055236 |
| comparative semen cryopreservation in ferrets (mustela putorius furo) and pregnancies after laparoscopic intrauterine insemination with frozen-thawed spermatozoa. | a study was conducted to determine an optimum technique for semen cryopreservation and the biological competence of frozen-thawed ferret spermatozoa. fifty-two fresh electroejaculates from 4 males were evaluated for sperm percentage motility, forward progressive motility, motility index (smi) and acrosomal integrity. to determine the optimum temperature for maintaining sperm motility in vitro and the influence of glycerol on sperm motility, seminal aliquants were diluted in test diluent (contain ... | 1991 | 2056481 |
| the effect of pulpectomy on the longitudinal distribution of nerve fibres in the periodontal ligament of the ferret. | the innervation density of the periodontal ligament was measured at a series of levels around the mandibular canines of 6 ferrets, in 5 of the which the pulp of one of each of these pairs of teeth had been removed 3 months earlier. in control (unoperated) teeth the density of innervation was greatest in the apical third and lowest in the coronal third. the pattern around the pulpectomized teeth was similar. there was no statistically significant difference between density values for control and ... | 1991 | 2059164 |
| the length, width and volume of isolated rat and ferret ventricular myocytes during twitch contractions and changes in osmotic strength. | the length and width of rat and ferret ventricular myocytes have been measured using a linear photodiode array; the volume of the myocytes has been calculated based on the assumption that the cells were elliptical cylinders. during a twitch contraction, there was a decrease in cell length, but no significant change in the calculated cell volume, because the cells increased in width. inotropic interventions not only resulted in a greater shortening of the cell during each contraction, but also a ... | 1991 | 2059429 |
| albino gene dosage and retinal decussation patterns in the pigmented ferret. | we have examined the retinal decussation patterns in pigmented ferrets that were either wild-type sable or heterozygous with one albino gene. unilateral injections of horseradish peroxidase were made into the optic tract and labeled ganglion cells visualized in retinal wholemounts. in both wild-type and heterozygous ferrets, those ganglion cells in the temporal retina with the largest cell bodies projected only to the contralateral side of the brain. the total number of ipsilaterally projecting ... | 1991 | 2059573 |
| the effect of acidosis on the relationship between ca2+ and force in isolated ferret cardiac muscle. | 1. the relationship between force and intracellular [ca2+] (monitored using the protein aequorin) has been investigated in papillary muscles isolated from ferret hearts, under control conditions (superfusate ph (pho) 7.3) and during acidosis (pho 6.8). 2. at pho 7.3, increasing bathing [ca2+] from 0.5 mmol l-1 to 8 mmol l-1 led to an increase in the size of the intracellular calcium transient. at the lower [ca2+] this was accompanied by an increase in developed force; however, at the higher bath ... | 1991 | 2061846 |
| neonatal testosterone masculinizes sexual behavior without affecting the morphology of the dorsal preoptic/anterior hypothalamic area of female ferrets. | we examined whether testosterone (t) administered to female ferrets neonatally--a treatment known to enhance masculine coital capacity--induces formation of the sexually dimorphic male nucleus in the dorsal preoptic/anterior hypothalamic area (mn-poa/ah), and/or sensitizes dorsal poa/ah neurons to the stimulatory effect of later androgen treatment on somal dimensions. in males, the mn-poa/ah was present in all subjects, and exposure to androgen following castration at postnatal day 56 (p56) incr ... | 1991 | 2070265 |
| estradiol binding in the sexually dimorphic nucleus of the preoptic/anterior hypothalamic area of adult male ferrets and in the equivalent region of females. | a large number of estradiol-concentrating cells were visualized by autoradiography in a subpopulation of large neurons located in and around the sexually dimorphic male nucleus of the preoptic/anterior hypothalamic area (mn-poa/ah) of castrated male ferrets and in a comparable dorsal portion of the poa/ah of ovariectomized females. considerably fewer estradiol-labelled cells were seen in the non-dimorphic ventral poa/ah nucleus of both sexes. estrogen binding in cells in or around the mn-poa/ah ... | 1991 | 2070266 |
| evaluation of the anti-influenza virus activities of 1,3,4-thiadiazol-2-ylcyanamide (ly217896) and its sodium salt. | 1,3,4-thiadiazol-2-ylcyanamide (ly217896) and its sodium salt were shown to be effective against influenza a and b viruses in vitro and in the mouse model. in nondividing confluent mdck cells, the 50% inhibitory concentration of ly217896 ranged from 0.37 to 1.19 micrograms/ml against various strains of influenza a virus and from 0.75 to 1.54 micrograms/ml against various strains of influenza b virus, with no apparent cytotoxicity. however, at a concentration of 0.31 microgram/ml, ly217896 inhibi ... | 1990 | 2073106 |
| visual response properties and afferents of nucleus of the optic tract in the ferret. | basic properties of responses to visual stimulation with large moving random dot patterns were studied in ferret nucleus of the optic tract. retinal input to not was assessed by orthodromic electrical stimulation of the optic chiasm and optic nerves. presence of an input from visual cortex was tested by orthodromic electrical stimulation of ipsilateral area 17. all 51 not neurons studied displayed a non-habituating, clearly direction-specific response: discharge rate strongly increased with the ... | 1990 | 2073937 |
| effects of early monocular deprivation on response properties and afferents of nucleus of the optic tract in the ferret. | effects of early monocular deprivation on visual response properties of neurons in the nucleus of the optic tract (not) were studied in six adult ferrets. retinal input to not was investigated by orthodromic electrical stimulation of optic chiasm and optic nerves. electrical stimulation of the ipsilateral primary visual cortex was applied to reveal the presence of a cortical pathway to not. all 75 neurons studied in the not displayed the typical strongly direction-specific response to horizontal ... | 1990 | 2073938 |
| the effects of cocaine on intracellular ca2+ handling and myofilament ca2+ responsiveness of ferret ventricular myocardium. | 1. when ferret right ventricular papillary muscles were stimulated with threshold punctate pulses (0.33 hz; 30 degrees c), cocaine, 10(-5) m, increased peak tension development from 815 +/- 120 to 1125 +/- 180 mg (p less than 0.05) and increased the rate of relaxation from peak tension (time to 80% decline from peak tension decreased from 155 +/- 11 to 144 +/- 11 ms; p less than 0.05). these changes in the twitch were associated with comparable changes in the amplitude and time course of the cal ... | 1990 | 2076484 |
| pulmonary arterial and venous constriction during hypoxia in 3- to 5-wk-old and adult ferrets. | we have determined the sites of hypoxic vasoconstriction in ferret lungs. lungs of five 3- to 5-wk-old and five adult ferrets were isolated and perfused with blood. blood flow was adjusted initially to keep pulmonary arterial pressure at 20 cmh2o and left atrial and airway pressures at 6 and 8 cmh2o, respectively (zone 3). once adjusted, flow was kept constant throughout the experiment. in each lung, pressures were measured in subpleural 20- to 50-microns-diam arterioles and venules with the mic ... | 1990 | 2077015 |
| ontogeny of the sexually dimorphic male nucleus in the preoptic/anterior hypothalamus of ferrets and its manipulation by gonadal steroids. | a sexually dimorphic nucleus exists in the dorsal region of the ferret preoptic/anterior hypothalamic area (poa/ah), and is called the male nucleus of the poa/ah (mn-poa/ah) because it is found only in males. development of the mn-poa/ah was studied in male ferrets, and for comparison a sexually nondimorphic ventral poa/ah nucleus was studied in both sexes. the mn-poa/ah was conspicuous in males as early as embryonic day 37 (e37) of a 41-day gestation, and its volume increased until postnatal da ... | 1990 | 2077101 |
| pulmonary vascular pressure profile in 2-3-week-old, 5-6-week-old and adult ferrets. | we have previously reported age-related differences in the pattern of vascular pressure drop in rabbit lungs (raj et al., pediatric res. 20:1107-1111, 1986). the purpose of this study was to investigate if there were similar age related differences in the ferret lung. to determine the profile of vascular pressures and the longitudinal distribution of vascular resistance in arteries, microvessels and veins, we isolated and blood perfused lungs of 20 ferrets (8 adults greater than 6 months of age; ... | 1990 | 2080320 |
| auditory brainstem of the ferret: early cessation of developmental sensitivity of neurons in the cochlear nucleus to removal of the cochlea. | the role of primary afferent innervation in the maintenance of neurons in the mammalian auditory system was assessed by performing unilateral removals of the cochlea in neonatal and mature ferrets of known birth dates. removals were performed under steroid anesthesia and resulted in the complete destruction of the organ of corti and the loss of at least 80% of type i spiral ganglion neurons. four main age groups [postnatal days (p)5, p24, p90, and p180] were used. additional animals received no ... | 1990 | 2081818 |
| effects of cholecystokinin (cck-8) on two classes of gastroduodenal vagal afferent fibre. | in order to investigate the vagal afferent pathway responsible for the previously reported effects of cholecystokinin (cck) on gastric emptying and food intake, single afferent fibres were recorded from the cervical vagus of urethane-anaesthetized ferrets. sixty tension receptor afferents with receptive fields in the corpus, antrum, duodenum, jejunum and ileum all showed a resting level of discharge which was augmented powerfully by distension of the segment containing the ending. close intraart ... | 1990 | 2084184 |
| ultrastructure of the leptomeninx of the fetal ferret spinal cord and cerebrum. | the ultrastructures of the leptomeninx of the spinal cord and cerebrum was examined in the 32 d post-conception fetal ferret. leptomeningeal cells of the fetal ferret spinal cord have a moderately electron dense cytoplasm and nucleoplasm. the cisternae of endoplasmic reticulum are filled with an amorphous material and are more numerous in cells covering the lateral part of the cord. collagen fibrils are also abundant in this region. glycogen granules are only rarely present and then only in arac ... | 1990 | 2088147 |
| isolation of campylobacter coli from a proliferative intestinal lesion in a ferret. | | 1990 | 2094455 |
| effects of length change on intracellular ca2+ transients in ferret ventricular muscle treated with 2,3-butanedione monoxime (bdm). | quick release of the right ventricular papillary muscle of ferrets, injected with aequorin, from lmax (initial length) to 92% lmax during twitch response produced an extra-light signal of aequorin. 2,3-butanedione monoxime (bdm) at 10 mm decreased the peak tension to less than 10% of that in control and the light signal to 70%. in the bdm-treated muscle, the extra-light in response to the quick release did not occur. a quick stretch from lmax to 103% lmax, in the presence and absence of bdm, did ... | 1990 | 2094785 |
| in vivo findings associated with heat generation during thermomechanical compaction of gutta-percha. 1. temperature levels at the external surface of the root. | temperature elevations of 10 degrees c above body temperature, of duration greater than 1 minute, may be sufficient to cause bone tissue injury. temperature rises on the root surface in excess of 10 degrees c have been shown in studies in vitro of thermoplasticized gutta-percha root filling techniques. to determine whether results in vitro at room temperature could be extrapolated to conditions in vivo, temperature elevations were recorded at the mid-point on the root surface of the canine tooth ... | 1990 | 2098343 |
| in vivo findings associated with heat generation during thermomechanical compaction of gutta-percha. 2. histological response to temperature elevation on the external surface of the root. | an in vivo investigation is described and a histological evaluation made of the effect of canal obturation by thermomechanical compaction of gutta-percha and sealer on the cementum on the lateral surface of the root and adjacent periodontal membrane and alveolar bone of the ferret canine after time intervals of 24 hours, 20 days and 40 days. these tissue reactions were compared with those in the roots of control teeth filled by lateral condensation of cold gutta-percha and sealer. iatrogenic dam ... | 1990 | 2098344 |
| magnesium transport in ferret red cells. | 1. mg2+ efflux from ferret red cells into a nominally mg2(+)-free medium is 41 +/- 2 mumol (l cell)-1 h-1. the properties of mg2+ transport can be measured in these cells without the need for mg2+ loading. 2. amiloride, quinidine, imipramine and external divalent cations partially inhibit mg2+ efflux. maximal inhibition by these agents is about 60-70% suggesting that at least two mg2+ transport pathways exist. 3. as external na+ is replaced by choline or n-methyl-d-glucamine mg2+ efflux is first ... | 1990 | 2100303 |
| submandibular responses to stimulation of the parasympathetic innervation in bursts in the anaesthetized ferret. | 1. submandibular salivary and vascular responses to different patterns of stimulation of the parasympathetic innervation have been investigated in anaesthetized ferrets in the presence and absence of atropine. 2. at low stimulus frequencies likely to fall within the physiological range (0.5-2.0 hz continuously; 5.0-20.0 hz in 1 s bursts at 10 s intervals) secretion of fluid and protein were both potentiated by the bursting pattern of stimulation and the latency of the secretory response was redu ... | 1990 | 2100312 |
| species differences in susceptibility to ischemic injury and responsiveness to myocardial protection. | isolated hearts from rabbits, hamsters, ferrets, gerbils, rats, mice and guinea pigs were used to investigate species differences in (i) stability during aerobic perfusion, (ii) susceptibility to ischemic injury and (iii) responsiveness to cardioplegic protection. during 120 minutes of continuous aerobic perfusion, the rate of functional deterioration differed between species. the rabbit was the most stable and the guinea pig the least: the mean +/- sem of the left ventricular developed pressure ... | 1990 | 2102801 |
| an efficient isolation procedure of ca-tolerant ventricular myocytes from ferret heart for applications in electrophysiological studies. | a simple procedure which provides a large yield of isolated ferret ventricular myocytes is described. the enzymatic dissociation was performed by perfusion of the whole heart with the "langendorff method" at 37 degrees c, without an incubation period. special attention was given to the period of perfusion with ca-free or low-calcium containing solutions and to the proportion of both collagenase and elastase used. the viability and calcium tolerance of the isolated cells were tested by ultrastruc ... | 1990 | 2103519 |
| control of ph of airway surface liquid of the ferret trachea in vitro. | we measured the ph of airway surface liquid (asl) secreted by the ferret trachea in vitro by using a catheter-tipped ph electrode implanted in a collecting cannula close to the airway epithelium. mucus secretion was promoted by methacholine (0.02 mmol/l) in the organ bath. the ph of the asl was 6.85 +/- 0.03 (se) compared with a bath value of 7.39 +/- 0.01, when the bath was bubbled with 5.65% co2. changing the bath co2 from 0 to 20.93% co2 altered the bath ph from 8.06 to 6.96, but the asl ph o ... | 1990 | 2107164 |
| quantification of [ca2+]i in perfused hearts. critical evaluation of the 5f-bapta and nuclear magnetic resonance method as applied to the study of ischemia and reperfusion. | calcium has been implicated as a mediator of cell injury in ischemia and reperfusion, but direct measurements of ca2+ are required to refine this idea. we used nuclear magnetic resonance spectroscopy and the ca2+ indicator 5f-bapta to measure [ca2+]i in perfused ferret hearts. several lines of evidence are presented to show that loading with the acetoxymethyl ester of 5f-bapta is not significantly complicated by accumulation of partially de-esterified metabolites, compartmentalization into mitoc ... | 1990 | 2110515 |
| a comparative biochemical and ultrastructural study of proteoglycan-collagen interactions in corneal stroma. functional and metabolic implications. | 1. corneas of mouse, rat, guinea pig, rabbit, sheep, cat, dog, pig and cow were quantitatively analysed for water, hydroxyproline, nucleic acid, total sulphated polyanion, chondroitin sulphate/dermatan sulphate and keratan sulphate, several samples or pools of tissue from each species being used. ferret cornea was similarly analysed for water and hydroxyproline on one pool of eight corneas. pooled frog (38) and ferret (eight) corneas and a single sample of human cornea were qualitatively examine ... | 1990 | 2119175 |
| large and small airway responses to bronchoconstrictors in the guinea pig and ferret. | in the isolated, perfused lung lobe of the ferret we evaluated the bronchoconstrictor response of its airways to methacholine and histamine, pharmacologic agents associated with the asthmatic state. the bronchus of excised lobes was cannulated and needle scarifications were made on the pleural surface to allow perfusate to exit. lung airways were perfused at constant flow with equilibrated 95% o2/5% co2, warmed krebs-ringers solution. perfusion pressure was measured as a gauge of airway resistan ... | 1990 | 2126832 |
| epithelium-derived pge2 inhibits the contractile response to cholinergic stimulation in isolated ferret trachea. | we have previously reported that epithelium-dependent inhibitory factors, both prostanoids and non-prostanoids, can be activated by electrical field stimulation (efs) and direct nerve stimulation (dns) in an in vitro nerve-muscle preparation of ferret trachea. in this study we set out to compare the release of the inhibitory prostanoids, pge2 and pgi2, in preparations with intact and with removed epithelium. ferret tracheae were mounted in organ baths and phasic contractions were induced by efs ... | 1990 | 2135219 |
| dexamethasone can potentiate the anti-emetic action of a 5ht3 receptor antagonist on cyclophosphamide induced vomiting in the ferret. | a new group of selective 5ht3 antagonists are proving to be effective anti-emetics for cytotoxic and radiation induced vomiting in both animal models and man. current anti-emetic regimens often benefit from combination therapy, in particular the efficacy of metoclopramide (which can be a weak 5ht3 antagonist), can be improved by combination with dexamethasone, another anti-emetic. hence it was of interest to evaluate whether a 5ht3 receptor antagonist gr38032f could be improved by combination wi ... | 1990 | 2137008 |