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[Early effects of explosion on hearing threshold and activities of Na+-K+-ATPase and succinic dehydrogenase in the stria vascularis of guinea pigs].

Slow cortex responses to several frequencies were recorded in guinea pigs before and after intense impulse noise exposure. Guinea pigs were decapitated 90 minutes after the exposure. Besides scanning electron microscopic analysis of cochleas, activities of Na(+)-K(+)-ATPase and SDH in the stria vascularis (SV) corresponding to 4 kHz were studied with histochemical methods under light microscope. Densities of histochemical reaction products and cross sections of the SV were measured with image analysis system. Activities of Na(+)-K(+)-ATPase and SDH in the SV decreased significantly in PTS grou…

Effects of several volatile anesthetics on the Ca(2+)-related functions of skinned skeletal muscle fibers from the guinea pig.

The effects of various volatile anesthetics on intramuscular Ca(2+)-related functions were studied with the skinned fiber technique in guinea pig skeletal muscles. All the volatile anesthetics tested significantly enhanced Ca(2+)-induced Ca2+ release (CICR) from the sarcoplasmic reticulum (SR) at clinical concentrations with negligible effects both on Ca2+ sensitivity of the contractile system and on Ca2+ uptake by the SR. A comparison was made of the enhancing effect of several volatile anesthetics on CICR at clinical concentrations. Halothane was the most potent, followed by methoxyflurane, …

Coenzyme Q10 attenuates cyanide-activation of the ATP-sensitive K+ channel current in single cardiac myocytes of the guinea-pig.

The effect of coenzyme Q10 (CoQ10) on the cyanide (CN-)-induced ATP-sensitive K+ channel current (KATP) was examined in single atrial myocytes, using the patch clamp technique. Superfusion of the cells with a CN-/low glucose bathing solution induced an outward current in the whole-cell clamp condition. Glibenclamide (1 microM) abolished this current, indicating that the current was carried through the KATP channel. After steady-state activation by CN-, pinacidil (a KATP channel opener, 300 microM) failed to further increase the current. In cell-attached patches, CN-, when applied to the bath,

Effects of Tityus serrulatus scorpion venom and one of its purified toxins (toxin gamma) on the isolated guinea-pig heart.

1. The effects of Tityus serrulatus scorpion venom and its most important toxin (toxin gamma) were investigated on isolated guinea-pig hearts, perfused with Locke solution, by the Langendorff's method. 2. The cardiac contraction, the coronary flow and the electrocardiogram (ECG) were simultaneously recorded. 3. Bolus injections of 25, 50 or 100 micrograms of scorpion venom and 2.5, 5 or 10 micrograms of toxin gamma in the heart evoked complex effects which were divided into 3 phases: an initial phase (tachycardia or bradycardia associated with an increase in contractile force), an intermediate…

Guinea-pig isolated trachealis: the effects of charybdotoxin on mechanical activity, membrane potential changes and the activity of plasmalemmal K(+)-channels.

1. A study has been made, in guinea-pig isolated trachealis, of the effects of charybdotoxin in modulating (a) the activity of large conductance K(+)-channels, (b) the spontaneous electrical activity of intact cells and (c) the mechanical effects of some bronchodilator drugs. 2. Single smooth muscle cells were isolated from guinea-pig trachealis by enzymic digestion and were studied by the patch clamp recording technique. Recordings were made from outside-out plasmalemmal patches when the medium bathing the external surface of the patches contained 1.2 mM Ca2+ and 6 mM K+ while that bathing th…

Value of the cutaneous basophil hypersensitivity (CBH) response for distinguishing weak contact sensitization from irritation reactions in the guinea pig.

Numerous studies of the histology of allergic contact dermatitis reactions to potent allergens in guinea pigs and humans have indicated that there is significant tissue infiltration with basophilic leukocytes. In this study we determined whether this histologic finding could be of value in distinguishing weak sensitization reactions from primary irritation, thereby aiding in the predictive identification of weak or moderate contact allergens. Guinea pigs were sensitized by the Buehler test method. Skin reactions were graded 24, 48, and 72 h post-challenge with duplicate patch sites biopsied at…

Human recombinant lymphokines and cytokines induce pulmonary eosinophilia in the guinea pig which is inhibited by ketotifen and AH 21-132.

Subcutaneous or intraperitoneal injection of recombinant human granulocyte-macrophage colony-stimulating factor, interleukin 3, or mouse tumour necrosis factor alpha, but not recombinant human interferon gamma, platelet-derived growth factor, or transforming growth factor beta caused selective eosinophilia of the pulmonary airways in the guinea pig. Unlike responses to platelet-activating factor, there was no attendant detectable airway hyperreactivity, but in common with responses to platelet-activating factor, eosinophilia of the airways was prevented by pretreatment with ketotifen or AH21-1…

[Estimation of the ionic mechanism of inotropic agents from the shifting pattern of frequency-force relationship in guinea pig ventricular myocardium].

Experiments were carried out to get information about the shifting mode of the frequency-force relationship curve (FFRC) of several well-established agents in guinea pig ventricular myocardium to estimate the ionic mechanism of inotropic action. The increase in [Ca2+]o or decrease in [Na+]o shifted the FFRC to the left and upwards, but no shift was observed when [Ca2+]o/[Na+]o2 ratio was kept constant. Drugs increasing [Na+]i (veratridine, asebotoxin) caused a parallel leftward shift of FFRC in the middle range of contraction frequency. Tetrodotoxin depressed the force of contraction (Fc) at h…

Effects of cadmium ions, D-600 and KCN on calcium-45 uptake in smooth muscle of guinea-pig taenia coli.

1. The effects of Cd2+ on Ca2+ uptake was compared with that of D-600 and KCN in guinea-pig taenia coli. Cd2+ inhibited both the phasic and tonic K+ responses, however, D-600 and KCN preferentially inhibited the tonic response. 2. Cd2+ (2 x 10(-6) M) which had no effect on the tissue ATP concentration, inhibited La3+ resistant residual Ca2+ binding at the high and low affinity site. Cd2+ (10(-5) M) which decreased the tissues ATP concentration, markedly inhibited Ca2+ binding at the low affinity site. 3. Both D-600 and KCN showed a greater inhibitory effect on Ca2+ binding at the low affinity …

Evaluation in Papua New Guinea of a urine coagglutination test and a Widal slide agglutination test for rapid diagnosis of typhoid fever.

Two simple rapid tests for the laboratory diagnosis of typhoid fever were evaluated, a coagglutination test for detecting Salmonella typhi antigens in urine and a Widal slide agglutination for detecting serum antibodies. Ninety-two culture-confirmed typhoid cases were compared with 64 non-typhoid fever patients, 50 close contacts of typhoid patients, 30 vaccinated staff and 72 healthy community members. A strong urine Vi coagglutination was found to be 86.5% sensitive and 91.8% specific for typhoid, but was not always easy to read. The slide Widal H was found to be 99% sensitive and 95% specif

Effect of four-week repeated inhalation exposure to unconjugated azodicarbonamide on specific and non-specific airway sensitivity of the guinea pig.

Reports of respiratory problems among industrial workers exposed repeatedly by inhalation to azodicarbonamide (ADA) raised concern that ADA might be a pulmonary sensitizer. We used a non-invasive method for measuring specific airway conductance to evaluate the potential for repeated inhalation of unconjugated ADA to cause specific or non-specific pulmonary sensitization in the guinea pig. Two groups of male Hartley guinea pigs were exposed 6 h/day, 5 days/week for 4 weeks to aerosolized ADA at 51 or 200 mg/m3, or to filtered air as controls. One group was tested for specific sensitization to A…

Effects of alaproclate, potassium channel blockers, and lidocaine on the release of 3H-acetylcholine from the guinea-pig ileum myenteric plexus.

The guinea-pig ileum longitudinal muscle-myenteric plexus preparation, preincubated with 3H-choline or 3H-noradrenaline, was mounted in an organ bath and superfused with Tyrode's solution. Alaproclate (2-(4-chlorophenyl)-1,1-dimethyl 2-aminopropanoate) (0.01-0.5 mmol/l) reduced (IC50 = 0.1 mmol/l) and at about 0.5 mmol/l completely blocked the electrically evoked 3H-acetylcholine secretion. The depressing effect of alaproclate (0.2 mmol/l) was not counteracted by atropine (0.01, 1 or 10 mumol/l), hexamethonium (0.1 mmol/l), phentolamine (1 mumol/l) yohimbine (1 mumol/l), haloperidol (1 mumol/l…

Evidence for tonic activation of prejunctional beta-adrenoceptors in guinea-pig pulmonary arteries by adrenaline derived from the adrenal medulla.

1. The effects of (+/-)-carteolol 10(-8) M to 10(-6) M, a non-selective beta-antagonist, applied cumulatively, on stimulation-evoked 3H-release at 1 Hz were studied in pulmonary arteries isolated from guinea-pigs. The guinea-pigs were subjected to either bilateral adrenalectomy, adrenalectomy followed by injections of deoxycorticosterone acetate (DOCA) and hydrocortisone, bilateral adrenodemedullation or a sham operation, and then loaded in vitro with [3H]-noradrenaline. 2. Carteolol inhibited 3H-output in arteries from sham-operated animals in a concentration-dependent manner. This inhibitory…

Защита морских свиней от лихорадки Ласса с помощью рекомбинированных вирусов вакцины, выражающих нуклеопротеин или конверты гликпротеинов вируса Ласса.

Вирус рекомбинантной вакцины, выражающий ген нуклеопротеина вируса Ласса (сегмент Джосии) под контролем промоутера P7,5, был построен с помощью вектора совместного экспрессии LacZ pSC11. Южный анализ пятна показал, что рекомбинация последовательности, встроенной в ген тимидина киназы переносного вектора в фрагмент геном ДНК вируса Вакцины HindIII J, произошла надлежащим образом. Протеиновый протеин 63 кДа, идентичный электрофоретической подвижности к подлинному лассе нуклеопротеину, был замечен в рекомбинантных лизатах клеток, инфицированных вирусом. Реактивность белков Ласса, выраженных вакци

Совпадение в аннотации оригинала
A recombinant vaccinia virus that expresses the nucleoprotein gene of Lassa virus (Josiah strain) under the control of the P7.5 promoter was … differences between authentic and recombinant virus-expressed proteins. Vaccine efficacy trials in guinea pigs indicated that both the nucleoprotein and the envelope glycoproteins are capable of eliciting a protective immune response against a lethal dose of Lassa virus. Ninety-four percent of the animals vaccinated with V-LSN, 79% vaccinated with V-LSG …

[Simultaneous determinations of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure measurements in noise stress in guinea pigs].

In 14 guinea pigs the pO2 in the perilymph of the scala tympani fell to 50%-80% of the original value during exposure to noise consisting of 4,000 Hz clicks with a repetition rate of 20/s, 100 dB CHL = 120 dB SPL p.e., repeated twice over a period of 24 minutes each time. For the measurements of the pO2 we used the thin 0.5 micron micro-coaxial needle electrode described by Baumgärtl and Luebbers, which was placed through the round-window membrane in the scala tympani to a depth of 600 micron. The simultaneously recorded CAP latency times were prolonged by 0.8 ms at a test loudness of 60 and 8…

Haloperidol, chlorpromazine and lithium chloride antagonize the excitatory action of forskolin and of some gut peptides on guinea-pig myenteric neurones.

The effects of haloperidol, chlorpromazine and lithium chloride on electrical behaviour of AH/type 2 myenteric neurones from guinea-pig ileum as well as on the excitatory action of forskolin and of some gut peptides were studied. Haloperidol and chlorpromazine decreased the excitability of AH/type 2 myenteric neurones which was evidenced from the inhibition of spontaneous and electrically-evoked action potentials recorded intracellularly from neurones. Forskolin caused excitation in AH/type 2 neurones which mimicked the changes in neuronal behaviour that occur during the slow synaptic excitato…

Comparative clinico-morphological investigations of the CNS of monkeys and of the eye teguments of guinea pigs infected with different measles virus strains.

Measles virus strains Edmonston and L-16 have been studied in 10 intracerebrally (i.c.) infected monkeys and in 155 guinea pigs infected into the anterior eye chamber. The strains appeared to differ in pathogenicity for monkeys and guinea pigs. The more pathogenic Edmonston strain caused encephalitis in monkeys, whereas in guinea pigs it caused iridocyclitis, keratoconjunctivitis and follicular conjunctivitis. Strain L-16 was not neurovirulent for monkeys, while in guinea pigs it caused follicular conjunctivitis. Specific pathohistological changes detected in the CNS of monkeys and in the eye …

Analysis and comparison of immune reactivity in guinea-pigs immunized with equivalent numbers of normal or radiation-attenuated cercariae of Schistosoma mansoni.

Guinea-pigs immunized with equivalent numbers of normal or radiation-attenuated cercariae of Schistosoma mansoni are known to develop close to complete resistance to reinfection at weeks 12 and 4.5 respectively. We here analyse and compare the immune responses induced by the two populations of cercariae. Both radiation-attenuated and normal parasites of S. mansoni elicited an extensive germinal centre response in guinea-pigs by week 4.5 post-immunization. The anti-parasite antibody titre and cytotoxic activity of serum from 4.5-week-vaccinated, or 4.5-week-infected guinea-pigs were approximate…

Experimental tinea pedis induced by non-abrasive inoculation of Trichophyton mentagrophytes arthrospores on the plantar part of a guinea pig foot.

Arthrospores of Trichophyton mentagrophytes were inoculated on to the plantar part of a guinea pig foot by a newly devised non-abrasive method. Anthropophilic and zoophilic isolates required inocula of 280 and 80 arthrospores to infect 50% of inoculated feet, but much larger inocula (5 X 10(4)) were used to establish infection consistently in all feet. Anthropophilic isolate NTM-105 invaded only the upper two-thirds of the horny layer and induced no inflammatory responses. On the other hand, zoophilic isolate SM-110 invaded the whole horny layer and provoked strong inflammatory responses and c…

Suppression by muscarinic M2 stimulation of the contractile mechanism via histamine H1 receptors in the longitudinal muscle of guinea pig ileum.

The longitudinal muscle of the guinea pig ileum is well known to contract in response to stimulation of either muscarinic or histamine H1 receptors. However, we found that simultaneous application of agonists to both receptors, methacholine (MeCh) and histamine (Hist), at their maximum concentrations (both at 10(-5) M), induced a contraction of the muscle with a pattern very similar to that observed with MeCh alone. In the muscle contracted by MeCh, a muscarinic antagonist, atropine, caused a transient relaxation, but a histamine H1 blocker, pyrilamine, had no effect on the tension. Experiment…