Результаты поиска

The ability of salbutamol and theophylline to suppress immediate allergic conjunctivitis in the guinea pig.

Topically administered salbutamol was extremely effective in suppressing immediate allergic conjunctivitis in the guinea pig; a dose as low as 0.1% elicited 98% inhibition. Topical pretreatment with 1% propranolol completely blocked the suppressant action of 0.1% salbutamol. This was also the case after systemic propranolol (1 mg/kg SC); the beta-adrenoceptor antagonist itself has no effect on antigen-induced inflammation. The effect of 0.1% salbutamol was unaltered by pretreatment with the specific beta 1-adrenoceptor antagonist betaxolol (1 mg/kg SC). In marked contrast, the suppressant acti…

The effects of methylxanthines, ethymizol, ephedrine and papaverine on guinea pig and dog trachea.

The study was aimed to compare the effects of pentoxyphylline, aminophylline, choline theophyllinate and ethymizol on guinea pig and dog trachea with those of theophylline, papaverine and ephedrine. The effects of these drugs on the basal tension, on dose-response curves for muscle contraction produced by histamine and on cAMP level were investigated in guinea pig trachea, together with their influence on the resting and histamine-evoked mechanical and membrane activities of dog trachea. Like papaverine, pentoxyphylline did not alter the resting membrane potential, although it relaxed both tra…

Neuroleptic-induced changes in the firing pattern of guinea pig nigrostriatal neurons.

It is well established that neuroleptics increase the firing rate of nigrostriatal neurons. However, the action of these drugs on firing pattern has received scant attention. The effect of local administration of neuroleptic agents was investigated on the firing pattern, and also firing rate, of nigrostriatal neurons. Chlorpromazine or haloperidol was microinjected into the substantia nigra of the urethane-anaesthetized guinea pig during extracellular recordings from identified nigrostriatal cells. Both neuroleptics induced the familiar increase in firing rate of nigrostriatal neurons. More si…

Labetalol protects against the potentiation by propranolol of the bronchospasm to norepinephrine in guinea-pigs.

The increase in airway obstruction observed in asthmatics after treatment with beta-adrenergic blockers may be attributed to an unopposed alpha-adrenergic activity. Labetalol is an antihypertensive agent with beta-adrenoreceptor and alpha-adrenoreceptor blocking properties. Labetalol does not cause a bronchospasm in human asthmatics. Norepinephrine (0.025-0.1 mg/kg, i.v.) caused a bronchospasm in guinea-pigs after the blockade of beta-adrenoreceptors with propranolol (0.1-1 mg/kg, i.v.), but not after beta-blockade with labetalol (0.1-10 mg/kg, i.v.). Labetalol significantly protected against …

[Anatomy of the central auditory pathway. Demonstration with horseradish peroxidase in the guinea pig].

The neurones of the afferent and efferent auditory pathways were labelled by axonally transported horseradish peroxidase. The first neurone of the ascending system is the acoustic nerve with the spiral ganglion. These fibres terminate mainly in the ventral cochlear nucleus (VCN). The neurones of the latter chiefly run to the contralateral superior olivary complex (SOC), whereas the neurones of the dorsal cochlear nucleus (DCN) terminate mainly in the central nucleus of the contralateral inferior colliculus (IC). The nerve cells of the superior olivary complex and nuclei of the lateral lemniscu

Воздействие полиморфоядерного истощения на экспериментальную аргентинскую геморрагическую лихорадку у морских свиней.

Роль полиморфоядерного лейкоцита (ПМН) в аргентинской геморрагической лихорадке (AHF), эндемо-эпидемической болезни, вызванной вирусом Хунин (JV), была исследована в экспериментально зараженных свинках, истощенных PMN в результате применения специфической антисеремии. У лейкопентических животных эволюция инфекции с высокопатогенным штаммом JV была более серьезной, с более ранней смертностью и более высоким уровнем вирусной урожайности в крови и висцерии. В ходе патологического исследования были выявлены аналогичные повреждения как у контрольных, так и у обезжиренных животных, за исключением ле

Совпадение в аннотации оригинала
The role that polymorphonuclear leukocytes (PMN) may play in Argentine hemorrhagic fever (AHF), an endemo-epidemic disease caused by Junín virus (JV), was investigated in experimentally infected guinea pigs depleted of PMN by means of specific antiserum. In leucopenic animals the evolution of the infection with a highly pathogenic strain of JV was more sever…

The epidemiology of cryptosporidiosis and other intestinal parasitoses in children in southern Guinea-Bissau.

In order to determine the prevalence of Cryptosporidium and other intestinal parasites, a household sample survey of children under 5 years old was carried out during the late dry season in 8 rural villages in southern Guinea-Bissau, West Africa. Cryptosporidium oocysts were found in 10 of 270 stool samples (3.7%), using a safranin-methylene blue staining method. Of these 10 children (age range 5-16 months), all non-Muslims, 6 had diarrhoea, giving a prevalence of 12.5% in 48 children with diarrhoea, compared with 1.8% in children without diarrhoea (P less than 0.001). The ethnic group with th…

Neuropeptide Y and the ocular innervation of rat, guinea pig, cat and monkey.

By the immunohistofluorescence technique, peripheral nerves of the rat, guinea pig, cat and monkey eye contain a neuropeptide Y-like immunoreactive peptide. A broad distribution of immunoreactive nerve fibers is present in all four animals, innervating tissues of the aqueous humor outflow apparatus, the limbal blood vessels, and uveal blood vessels. A dense plexus of neuropeptide Y-like immunoreactive nerve fibers is present to the ciliary processes. A rich innervation exists to the iris dilator muscle, but that to the iris sphincter is modest. Throughout all regions of the uvea, neuropeptide …

Comparison of the muscarinic cholinoceptors in the rabbit ciliary body and the guinea-pig ileum.

Interactions of several muscarinic drugs with their receptors were studied in the ciliary body smooth muscle of rabbits and the ileal longitudinal muscle of guinea-pigs, using pharmacological and biochemical procedures. The dissociation constants of carbachol, pilocarpine, atropine and pirenzepine estimated by these procedures indicate no heterogeneity of muscarinic receptors in either tissue; thus both are probably of the M2 type. However, the density of the receptors in the ciliary body is lower than in the ileum. Pilocarpine, with lower intrinsic efficacy, demonstrated a pronounced organ se…

Lack of tolerance of morphine-induced spasm of guinea pig sphincter of Oddi.

To determine whether guinea pigs chronically exposed to morphine would develop tolerance to the morphine-induced contraction of the sphincter of Oddi (SO), adult male guinea pigs were implanted with morphine pellets (100 mg morphine). The effect of increasing IV doses of morphine on the SO was assessed by determining the duration of which saline perfusate stopped flowing into the duodenum of morphine-treated guinea pigs (MTGP) vs nonimplanted animals (non-MTGP). Isolated bovine and guinea pigs SO were also challenged with morphine. In the in vivo experiments the spasmogenic response of the SO …

The effect of cisapride on smooth muscle cells of guinea-pig taenia caeci.

Cisapride (5 X 10(-7) M) caused depolarization, enhancement of spike activity, increase in muscle tone and potentiation of the contraction evoked by transmural stimulation of taenia caecum of the guinea-pig at 35 degrees C. At higher cisapride concentrations (2.5 X 10(-6) M) the potentiation of the evoked contraction was less pronounced or was even reversed into inhibition. Muscle tone was also enhanced by cisapride after relaxation of the smooth muscle cells by isobutylmethylxanthine (4 X 10(-5) M), a phosphodiesterase inhibitor. This effect of cisapride on muscle tone was smaller in the pres…

Immunopathology of guinea pig autoimmune enterocolitis induced by alloimmunisation with an intestinal protein.

An enterocolitis has been induced in guinea pigs by alloimmunisation with a mucosal protein. A single dose of immunogen fails to provoke a synthesis of precipitant antibodies, but a high percentage of animals, injected with two or more doses, develop these antibodies. A specific cell mediated immune response was already detectable 30 days after a single dose of immunogen. At later periods and after multiple doses of immunogen positive results were still found, although in a lesser percentage of the animals. The pathology was characterised by the appearance of multiple mucosal ulcerations, cong…

The comparative study of patterns of guinea worm prevalence as a guide to control strategies.

Guinea worm, a parasite found in unprotected drinking water sources, causes considerable morbidity and loss of agricultural production among rural people in India and West Africa. A comparative study of village level prevalence data in the two regions reveals marked contrasts in the level and characteristics of prevalence which are useful guidelines in planning control strategies where little is known about local guinea worm epidemiology. Prevalence rates of up to 75-80% of the total population of a settlement have been found in West Africa, far higher than those in India. The higher figure in…

Caprolactam-barbiturate interaction at the GABAA receptor complex in the guinea-pig intestine.

4,6,6-Trimethylcaprolactam antagonised GABAA receptor-mediated contractile responses in guinea-pig isolated ileum, displacing the GABA dose-response curve to the right in a non-parallel manner, and causing a depression of the maximum response. Pentobarbitone not only potentiated the GABAA receptor-mediated contractions but also reversed this non-competitive antagonism by 4,6,6-trimethylcaprolactam, shifting the dose-response curve for GABA to the left and restoring the maximum response. It is conclude that this caprolactam acts at the picrotoxin-barbiturate site on the Cl(-)-ionophore complex.

Inhibition of passive systemic anaphylaxis in guinea pigs by Trichinella spiralis infection.

Thirty of 33 guinea pigs experimentally infected with Trichinella spiralis survived passive systemic anaphylactic reactions which were fatal for 32 of 33 uninfected controls. Guinea pigs were infected with viable excysted trichinella larvae 20 to 32 days before they and uninfected controls were sensitized by intracardiac injection of rabbit anti-bovine serum albumin. Animals were challenged 24 hours later by intracardiac injection of bovine serum albumin. Respiratory anaphylaxis was observed in all challenged animals. Protection from passive anaphylaxis in parasitized guinea pigs was most like…

Efficacy of pefloxacin in comparison with erythromycin in the treatment of experimental guinea pig legionellosis.

Pefloxacin was compared to erythromycin in the treatment of guinea pigs severely infected with Legionella pneumophila. In this experimental model, two single intraperitoneal injections of either pefloxacin (10 mg/kg at 48 h and 5 mg/kg at 55 h) or erythromycin (40 mg/kg at 48 and 55 h) were administered 48 h post-infection (2 X 10(7) virulent L. pneumophila intraperitoneally). Counts of bacteria in blood monocytes and lungs of animals killed at different times after the completion of treatment, demonstrated a quick and highly significant reduction of the pretreatment bacterial load in pefloxac…

Contractile properties and histochemistry of extraocular muscle in the pigmented and the albino guinea pig.

The inferior oblique muscles of pigmented and albino guinea pigs were compared with respect to contractile and histochemical properties. No differences were found between the 2 kinds of animal in twitch and tetanic response or in fatigue properties. They also had the same fiber composition and fiber and capillary densities of their inferior obliques. These findings indicate that differences in eye muscle previously demonstrated and Siamese (albino) cats are related to the state of binocular vision and not to genetic variations between pigmented and albino animals.

Absence of progesterone effects on chlamydial genital infection in female guinea pigs.

The effect of progesterone alone and in combination with estradiol was investigated in ovariectomized and gonadally intact female guinea pigs infected with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). The course of the infection, as determined by the percentage of cells with GPIC (chlamydia) inclusions in Giemsa-stained vaginal scrapings, was not affected in animals receiving 5.0 mg of progesterone daily. Progesterone had no influence on the enhancement of infection by estradiol. In comparison with sesame oil-treated controls, infection was prolonged by four to six days …