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Role of Ca2+ stores in acetylcholine-induced all-or-none shortening of smooth muscle cells from guinea-pig taenia caecum.

1. We have reported previously that isolated single smooth muscle cells from guinea-pig taenia caecum respond to acetylcholine (ACh) in an all-or-none manner. 2. To clarify the roles of intracellular Ca(2+) stores in the all-or-none response of isolated smooth muscle cells from guinea-pig taenia caecum to ACh, we examined the inositol 1,4,5-trisphosphate (IP(3))-induced contractile response in Staphylococcus aureus alpha-toxin-permeabilized smooth muscle cells and the effect of depletion of intracellular Ca(2+) stores on the all-or-none response to ACh in intact smooth muscle cells. 3. alpha-T…

Dendroaspis natriuretic peptide relaxes gastric antral circular smooth muscle of guinea-pig through the cGMP/cGMP-dependent protein kinase pathway.

AIM: To systematically investigate if cGMP/cGMP-dependent protein kinase G (PKG) signaling pathway may participate in dendroaspis natriuretic peptide (DNP)-induced relaxation of gastric circular smooth muscle. METHODS: The content of cGMP in guinea pig gastric antral smooth muscle tissue and perfusion solution were measured using radioimmunoassay; spontaneous contraction of gastric antral circular muscles recorded using a 4-channel physiograph; and Ca(2+)-activated K(+) currents (I(K(Ca))) and spontaneous transient outward currents (STOCs) in isolated gastric antral myocytes were recorded usi…

Protective effects of S+ ketamine and atropine against lethality and brain damage during soman-induced status epilepticus in guinea-pigs.

Soman poisoning is known to induce full-blown tonic-clonic seizures, status epilepticus (SE), seizure-related brain damage (SRBD) and lethality. Previous studies in guinea-pigs have shown that racemic ketamine (KET), with atropine sulfate (AS), is very effective in preventing death, stopping seizures and protecting sensitive brain areas when given up to 1h after a supra-lethal challenge of soman. The active ketamine isomer, S(+) ketamine (S-KET), is more potent than the racemic mixture and it also induces less side-effects. To confirm the efficacy of KET and to evaluate the potential of S-KET …

Elimination of 2-arachidonoylglycerol action by direct hemoperfusion through immobilized polymyxin B fibers: an experimental study in conscious guinea pigs.

Direct hemoperfusion through a network of immobilized polymyxin B fibers is used for the treatment of septic shock, but the mechanism underlying the clinical benefits remains unclear. The aims of the present study were to assess the actions of direct hemoperfusion through immobilized polymyxin B fibers on effects of exogenous endotoxin or 2-arachidonoylglycerol in conscious guinea pigs; and to examine the underlying mechanisms. In the present study, colonic motion was monitored continuously by telemetry using a force transducer attached to the taenia caecum, while blood pressure was monitored …

Venezuelan equine encephalitis virus in the guinea pig model: evidence for epizootic virulence determinants outside the E2 envelope glycoprotein gene.

Epizootic strains of Venezuelan equine encephalitis virus (VEEV) cause epidemics by exploiting equines as highly efficient amplification hosts for mosquito transmission. Although phylogenetic studies indicate that epizootic VEEV strains emerge via mutation from enzootic progenitors that are incapable of efficient equine amplification, the molecular mechanism(s) involved remain enigmatic. The convergent evolution of E2 envelope glycoprotein mutations suggests that they are critical to VEEV emergence, but little is known about the role of non-envelope genes. We used the guinea pig, the small ani…

Short report: the activity of pamaquine, an 8-aminoquinoline drug, against sporozoite-induced infections of Plasmodium vivax (New Guinea strains).

It was reported in 1946 that the administration of pamaquine during the incubation period delayed but did not prevent primary attacks of a New Guinea strain of Plasmodium vivax malaria. The observation that none of the four test subjects in this study had relapses has not previously been published and may have important implications for the evaluation of other 8-aminoquinoline compounds against relapsing vivax malaria.

[beta-adrenoceptor subtypes involved in relaxations of guinea-pig gastrointestinal smooth muscles: distribution and signaling pathway of beta 3-adrenoceptors].

The distribution and signaling pathway of beta 3-adrenoceptors involved in relaxations were examined in guinea-pig gastrointestinal smooth muscles. In esophagus, beta 1-adrenoceptors participate in isoprenaline-induced relaxations. However, both beta 2- and beta 3-adrenoceptors contribute to the relaxations in taenia caecum. In gastric fundus, duodenum, and ileum, beta 3-adrenoceptors were responsible for the relaxant responses. These results suggest that functional beta 3-adrenoceptors are present in four smooth muscles except esophagus. This was strongly supported by molecular analyses with …

Human immunodeficiency virus and other sexually transmitted infections among female sex workers in two major cities in Papua New Guinea.

BACKGROUND: Treatable sexually transmitted infections are very common in developing countries and quite often are inadequately treated or remain untreated despite the fact that they enhance the transmission of human immunodeficiency virus (HIV). GOAL: To estimate the prevalence of HIV, syphilis, chlamydial infection, gonorrhea, and trichomoniasis among female sex workers in Port Moresby and Lae, Papua New Guinea, and to collect data on associated behaviors. STUDY DESIGN: Self-identified female sex workers recruited through our peer-mediated sexually transmitted disease (STD)/HIV risk-reducti…

Syphacia longaecauda n. sp. (Nematoda: Oxyuridae) syphacinea from Melomys spp. (Muridae: Hydromyinae) from Papua New Guinea and Irian Jaya, Indonesia.

A new oxyurid nematode Syphacia (Syphacia) longaecauda n. sp. is described from the caecum and colon of the hydromyine rodents Melomys monktoni (type host) and M. rubex from Papua New Guinea and Irian Jaya, Indonesia. Syphacia longaecauda has an oval, laterally extended, relatively large cephalic plateau and can be distinguished from other species of Syphacia with similar characters by, amongst other features, tail length. The significance of the distribution of S. longaecauda, apparently restricted to New Guinea, is discussed.

Репликоны рекомбинантной РНК, полученные в результате ослабленного венесуэльского энцефалитного вируса, защищают морских свиней и мышей от вируса геморрагической лихорадки Эболы.

Репликоны РНК, полученные в результате ослабления штамма венесуэльского энцефалита (VEE), альфавируса, были разработаны как потенциальные вакцины от геморрагической лихорадки Эболы. Гены Эболы нуклеопротеина (NP) или гликпротеина (GP) были введены в VEE RNA вниз по течению от VEE 26S промоутер вместо VEE структурно-белковых генов. Полученные рекомбинантные репликоны, выражающие гены NP или GP, были упакованы в репликонные частицы VEE (соответственно NP-VRP и GP-VRP) с использованием двухпартийной системы поддержки, которая обеспечивала структурные белки VEE в трансе и предотвратила регенерацию

Совпадение в аннотации оригинала
RNA replicons derived from an attenuated strain of Venezuelan equine encephalitis virus (VEE), an alphavirus, were configured as candidate v … ility to protect against lethal Ebola infection were evaluated in BALB/c mice and in two strains of guinea pigs. The GP-VRP alone, or in combination with NP-VRP, protected both strains of guinea pigs and BALB/c mice, while immunization with NP-VRP alone protected BALB/c mice, but neither strain of guinea pig. Passive transfer of sera from VRP-immunized a …

Changes in cochlear blood flow due to intra-arterial infusions of angiotensin II (3-8) (angiotensin IV) in guinea pigs.

The effects of a newly discovered form of angiotensin, angiotensin IV (ANGIV), on cochlear blood flow (CBF) have been investigated utilizing the laser Doppler flowmetry (LDF) technique. Two specific questions were addressed: What are the effects of anterior inferior cerebellar artery infusions (AICA) of ANGIV on CBF and do angiotensin fragments other than ANGIV influence CBF in mature male and female guinea pigs. Infusions of ANGIV, and C-terminal shortened fragments were accomplished via micropipette into the AICA and changes in CBF were observed using LDF. The results demonstrated that 10 an…

Myocardial action potential prolongation by calcium channel activation under calcium free-EGTA conditions in guinea-pigs: developmental and regional variations.

Prolongation of action potentials upon the addition of various cAMP increasing agents under Ca2+ free-EGTA condition, which was previously suggested to be produced by persistent Na+ influx through Ca2+ channel due to lack of Ca(2+)-mediated inactivation, was examined in isolated myocardial preparations from neonatal and adult guinea-pigs. Application of isoproterenol under Ca2+ free-EGTA condition produced prolongation of the action potential duration in both neonatal and adult preparations from various regions of the heart. Both in the neonate and adult, the prolongation in the right ventricu…

Pulmonary tuberculosis in Guinea-Bissau: clinical and bacteriological findings, human immunodeficiency virus status and short term survival of hospitalized patients.

OBJECTIVE: To study tuberculosis patients in Guinea-Bissau with regard to clinical findings, bacteriologically verified diagnosis, human immunodeficiency virus (HIV) status and short term survival. DESIGN: 763 consecutive patients referred to the tuberculosis clinic with pulmonary symptoms underwent clinical examination and Ziehl-Neelsen sputum microscopy. Sputum for culture of mycobacteria on Löwenstein-Jensen medium was collected from all hospitalized patients, who were also screened by enzyme linked immunosorbent assay for the presence of HIV-1 and HIV-2 antibodies. HIV-positivity was conf…

Receptor for catecholamines responding to catechol which potentiates voltage-dependent calcium current in single cells from guinea-pig taenia caeci.

1. Single isolated cells were obtained from the taenia of the guinea-pig's caecum by enzymic digestion and held under voltage clamp. The effects of various catecholamines, sympathomimetics and related compounds were tested for their ability to potentiate the voltage-dependent calcium current (ICa) evoked in these cells by a depolarizing step. 2. ICa was potentiated by up to 60% by isoprenaline, adrenaline, and noradrenaline which were equipotent. The EC50 for isoprenaline was about 40 nM. 3. The racemic mixtures of the optical isomers of isoprenaline, adrenaline, and noradrenaline, and (+)-iso…

Air-interface cultures of guinea pig airway epithelial cells: effects of active sodium and chloride transport inhibitors on bioelectric properties.

To systematically study airway epithelial barrier properties and active ion transport processes during challenge to environmental toxicants, in vitro models that closely resemble airway epithelium in vivo are required. Guinea pig tracheobronchial epithelial (GPTE) cells cultured in an air interface form a tight, confluent monolayer, which may be a more suitable model for the studies of the airway epithelial barrier in vivo. In the present study, bioelectric properties of such GPTE cell monolayers were characterized with the use of pharmacological agents. Treatment of the basolateral side with …

Tracheal relaxing effects and beta 2-selectivity of TA-2005, a newly developed bronchodilating agent, in isolated guinea pig tissues.

Tracheal relaxing effects and beta 2-selectivity of TA-2005 were investigated by functional experiments and radioligand binding assay in guinea pigs in comparison with those of other beta-agonists, isoproterenol, procaterol, formoterol and salbutamol. The relaxing activity of TA-2005 on histamine-induced contraction in the isolated trachea was most potent among the five agonists, and it was blocked by a beta 2-selective antagonist (ICI 118,551) but not by a beta 1-selective antagonist (bisoprolol). The potency of the relaxing effect was in the order of TA-2005 (pD2 = 9.79) greater than formote…

Comparison of central versus peripheral nerve pathways to the guinea pig inferior mesenteric ganglion determined electrophysiologically after chronic nerve section.

The contributions of central versus peripheral nerve pathways to neurons of the inferior mesenteric ganglion of guinea pigs were studied. Nerve trunks innervating neurons in the ganglion were surgically sectioned and intracellular electrical responses to nerve stimulation were measured 6-8 days after surgery. Guinea pigs were divided into two experimental groups: (1) those that had the lumbar sympathetic chain ganglia (LSG) L2 through L4 removed and (2) those that had the intermesenteric, lumbar colonic and hypogastric nerves sectioned leaving central connections intact. After 6-8 days fast ex…

Prevention of non-specific airway hyperreactivity after allergen challenge in guinea-pigs by the PAF receptor antagonist SDZ 64-412.

1. Allergen challenge by aerosol in sensitized guinea-pigs elicited non-specific airway hyperreactivity assessed by reactivity to i.v. histamine or acetylcholine. Airway hyperreactivity to histamine persisted for at least 48 h and was accompanied by pulmonary eosinophilia as determined by bronchoalveolar lavage cell analysis. 2. Airway hyperreactivity was independent of vagal reflex mechanisms since it was not abrogated by bilateral vagotomy. 3. The novel platelet-activating factor (PAF) receptor antagonist SDZ 64-412 inhibited the development of airway hyperreactivity, as measured 24 h after …

Nerve fibers showing immunoreactivities for thyrosine hydroxylase and dopamine-beta-hydroxylase re-appear in the guinea pig uvea after sympathectomy.

After sympathectomy we have studied the re-appearance of nerve fibers showing catecholaminergic characteristics in the uvea of the guinea pig. Immunoreactivities for two catecholamine symthetizing enzymes, tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH), were used as markers. Both TH-like and DBH-like immunoreactive nerve fibers disappeared after the extirpation of ipsilateral superior cervical ganglion. In the choroid the TH-like and DBH-like immunoreactive nerve fibers re-appeared within 2 weeks. In the iris and the ciliary body both of these types of immunoreactive nerve fiber…

Peptide-containing neurons in explant cultures of guinea-pig myenteric plexus during development in vitro: gross morphology and growth patterns.

The gross morphology and growth patterns of substance P, enkephalin-, somatostatin- and vasoactive intestinal peptide-immunoreactive neurons have been studied in explant cultures of the myenteric plexus taken from beneath the newborn guinea-pig taenia coli, grown for up to 4 weeks in vitro. Substance P- and enkephalin-immunoreactive neurons were more abundant than somatostatin- and vasoactive intestinal peptide-immunoreactive neurons. The peptide-containing neuronal cell bodies were clearly visible in culture and exhibited characteristic gross morphologies similar to those described in situ, a…