Cerebellar cortical atrophy in a kitten.
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Animals↗
Biomedical subjects
Y Kaji
Publications and source records attributed to Y Kaji.
Effects of hydrocortisone on transmembrane currents in guinea pig ventricular myocytes--possible evidence for positive inotropism.
Steroid hormones are thought to have a positive inotropic action, but the precise electrophysiological effects which underlie this positive inotropism remain unknown. The effects of hydrocortisone on the L-type calcium current (ICa) of the isolated guinea pig ventricular cells were investigated under the whole-cell voltage-clamp recording. Hydrocortisone (10(-6) to 10(-5) M) increased the amplitude of ICa without any changes in the voltage-dependency in ICa. This agent retarded the fast inactivation component of ICa, but not the slow component. On the other hand, hydrocortisone slightly reduced the slope conductance of inward rectifying potassium current (IK1) at potentials less than -50mV. This effect on IK1 is favorable for the activation of ICa. Thus, these results indicate that the positive inotropism of hydrocortisone is mediated, at least in part, by a direct potentiating effect on ICa.
Animals↗
Pneumocystis carinii pneumonia in a thoroughbred foal.
Typical Pneumocystis carinii pneumonia was found in a male thoroughbred foal (46 days old) suffering from diarrhea and hypogammaglobulinemia after birth. The characteristics of the organisms were demonstrated by Grocott methenamine silver staining, and scanning and transmission electron microscopy. The present focal had no histological lesions suggesting immunodeficiency. However, he could not get adequate colostrum from his dam, because she died of hemorrhagic shock due to immuno-mediated thrombocytopenia at delivery. This condition was considered to have predisposed the foal to the pneumonia.
Animals↗
Thrombotic obstruction of the right coronary artery in a postoperative patient with Bland-White-Garland syndrome.
A 53-year-old female presented with symptoms of severe chest and back pain associated with oliguria. The patient had a history of exertional dyspnea since the age of 20, and easy fatigability since the age of 27. At the age of 41, she noted marked exacerbation of these symptoms after suffering from a cold and was ultimately diagnosed as having Bland-White-Garland (BWG) syndrome with mitral valve regurgitation. The patient then underwent re-implantation of an anomalous left coronary artery from the pulmonary artery to the posterolateral wall of the aorta. Eleven years later, she re-presented with symptoms of angina and congestive heart failure. Coronary angiography was subsequently performed and a total occlusion of the right coronary artery with probable thrombus was revealed. The right coronary artery was filled via collaterals from the implanted left coronary artery. Mitral regurgitation was noted during angiography. The patient underwent aorto-coronary artery bypass grafting of the right coronary artery and concomitant mitral valve replacement. Her postoperative condition remained excellent.
Coronary Angiography↗
The modulated receptor hypothesis revisited from the viewpoint of myocardial interstitial potential.
Time- and voltage-dependent interaction of antiarrhythmic agents with target cardiac ion channels is termed the modulated receptor hypothesis. Actually class I agents suppress the maximum upstroke rate (Vmax) of intracellular potential (Vic) depending on the pacing cycle length (PCL) and external potassium concentration ([K+]e). We examined this concept from the aspect of interstitial potential (Vis), since Vis reflects the second time derivative of Vic. Vic and Vis were recorded sequentially using standard microelectrode applied to the paced and superfused guinea pig papillary muscles. In the steady state, the greatest negative deflection of Vis (Vmin) was suppressed by quinidine (10 microM) in both PCL- and [K+]e-dependent manner, just like Vmax. However, quinidine-induced greater inhibition of Vmin than Vmax was evident at shorter PCL and greater [K+]e. Based on the sequential alteration of PCL and exposure to ouabain (10 microM), different quinidine sensitivity between Vmax and Vmin is most likely accounted for by the activity-dependent K+ efflux and Na(+)-K+ pump-mediated K+ uptake (i.e., [K+]e fluctuation). Thus, the modulated receptor hypothesis is concluded to be valid in terms of Vis.
Action Potentials↗
[The nature of the external ionic modulation of the myocardial electrical propagation: importance of the safety factor].
The mechanisms of conduction change depending on the extracellular K+ and Ca2+ concentrations ([K+]o and [Ca2+]o, respectively) were investigated. Simultaneous measurements of active and passive membrane properties and net membrane excitability were fulfilled by arranging the intra- and extracellular microelectrodes in a superfused and paced guinea pig papillary muscle. Internal longitudinal resistance (ri), as a parameter of passive property, was evaluated by the intra- and extracellular voltage ratio. The maximum upstroke rate (Vmax) was used as an active property. Apparent threshold potential (Vth) was defined by the breakpoint in the action potential upstroke fitted semilogarithmically. Graded rise in [K+]o (from 2.7 to 15.0 mM) evoked a progressive fall in Vmax, and was associated with less negative resting membrane potential and constant ri. Conduction velocity (theta) was the maximum in 9.0 mM [K+]o ("supernormal" conduction) but not in 2.7 mM [K+]o which gave the greatest Vmax ("subnormal" conduction). Safety factor of conduction (S), as an index of net excitability, could most readily account for the [K+]o-dependent change in theta. This was true also in the case of [Ca2+]o elevation (from 0.9 to 5.4 mM). These results indicate that the cation-modulated propagation is governed by the cable theory including S as a matrix of combined active and passive properties.
Action Potentials↗
Development of preparing small-amount samples for transmission electron microscopy.
The means of examination of small-amount samples by transmission electron microscopy (TEM) is described. In this study, the amount of cells necessary for TEM was examined by using a KMU-100 cultured cell line. Floating cells diluted with phosphate buffer solution (PBS) to several concentrations, were gathered in the tip of Beem capsules by means of centrifuge. After fixation, dehydration, and embedding with Epon 812, the samples were cut with a diamond knife, followed by electron staining, and examined by TEM. As a result, we learned that an amount of cells over 1 x 10(3) could be observed by TEM. In spite of cell damage through this procedure, the microscopic structures of the cells were relatively maintained compared with the original cell monolayers. In the near future, it may be possible to examine the sorted cells by flow cytometry (FCM) with TEM.
Brain Neoplasms↗
[The effects of transcorneal administration of prostaglandin E2 on rabbit eyes].
The pharmacologic effects of prostaglandin E2 (PGE2) on the anterior ocular segment were investigated. PGE2 was administered with a glass cylinder attached to the cornea in concentrations ranging from 0.05 to 500 micrograms/ml. The intraocular inflammatory reaction was assessed according to the changes in the anterior chamber flare, ocular tension, and components of the aqueous humor. We also performed experiments designed to inhibit the reactions induced by PGE2 using anti-inflammatory agents. The PGE2 elicited a single peak reaction in the anterior chamber flare, which recovered after several hours, and a transient elevation in the ocular tension in the early stage after PGE2 administration. Quantitative analysis of these two reactions revealed that both were dependent on the dose of PGE2 administered. The concentrations of ascorbic acid and glutathione, particularly that of the reduced form of the latter, were transiently reduced in the aqueous humor. The anterior chamber flares were suppressed by agents that inhibit arachdonic acid metabolism. These findings suggest that the metabolism of arachdonic acid becomes newly activated as a result of stimulation by PGE2 of extrinsic origin.
Animals↗
[The effects of calcium antagonists on prostaglandin E2 reaction in rabbit eyes].
We determined the effects of calcium antagonists (CAs) on prostaglandin E2 (PGE2) induced responses in the anterior ocular segment. PGE2 was administered to pigmented rabbit eyes with a glass cylinder attached to the corneal surface. CAs (nicardipine, verapamil, diltiazem: 125-1,000 micrograms/kg) were injected intravenously either once (30 min. before or at the same time as the PGE2 administration), or twice (at the same time as the PGE2 administration and 30 min. after). We evaluated the aqueous flare (AF) for 6 hours using a laser flare cell meter and intraocular pressure (IOP). A single peak rise of AF was observed about 1 hour after the PGE2 administration and a transient elevation of IOP 15-30 min. after. Intravenously injected CAs reduced these responses. Nicardipine (500-1,000 micrograms/kg) in particular significantly suppressed both the rise of AF and the IOP elevation. These results suggest that CAs suppress ocular inflammatory responses induced by PGE2 effectively.
Animals↗
Time sequential single photon emission computed tomography studies in brain tumour using thallium-201.
Time sequential single photon emission computed tomography (SPECT) studies using thallium-201 were performed in 25 patients with brain tumours to evaluate the kinetics of thallium in the tumour and the biological malignancy grade preoperatively. After acquisition and reconstruction of SPECT data from 1 min post injection to 48 h (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 15-20 min, followed by 4-6, 24 and 48 h), the thallium uptake ratio in the tumour versus the homologous contralateral area of the brain was calculated and compared with findings of X-ray CT, magnetic resonance imaging, cerebral angiography and histological investigations. Early uptake of thallium in tumours was related to tumour vascularity and the disruption of the blood-brain barrier. High and rapid uptake and slow reduction of thallium indicated a hypervascular malignant tumour; however, high and rapid uptake but rapid reduction of thallium indicated a hypervascular benign tumour, such as meningioma. Hypovascular and benign tumours tended to show low uptake and slow reduction of thallium. Long-lasting retention or uptake of thallium indicates tumour malignancy.
Brain↗
Malignant anorectal melanoma: usefulness of fat saturation MR imaging.
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Aged↗
Synergic activity of imipenem/cilastatin combined with cefotiam against methicillin-resistant Staphylococcus aureus.
The synergic activity of imipenem/cilastatin combined with cefotiam was studied in a mouse bacteraemia model. Combinations of imipenem plus cefotiam in ratios from 1:5 to 1:160 were more effective than either imipenem alone or cefotiam alone (P < 0.05). Synergy was observed against both beta-lactamase producing and beta-lactamase non-producing MRSA. Staggered combinations of imipenem with cefotiam (each drug was administered at a different time) were studied in an in-vitro pharmacokinetic system to clarify relationships between killing kinetics and pharmacodynamics of the combinations. In the in-vitro system, cefotiam (1 g over 30 min) administered 2 h after imipenem administration (250 mg over 30 min) reduced viable cell counts to an undetectable level and maintained this for 4 h, while the simultaneous administration of imipenem and cefotiam maintained an undetectable cell count for only 2 h. Furthermore, imipenem administered after cefotiam showed no synergy. These results indicate that the timing of dosing of each antibiotic influences synergy, and administration of cefotiam 2 h after imipenem is more effective than the other regimens.
Animals↗
Pelvic endometriosis: detection and diagnosis with chemical shift MR imaging.
Fat-saturation magnetic resonance (MR) imaging for detection and characterization of pelvic endometriosis was prospectively investigated in 35 women with a clinical diagnosis of the disease. Large endometrioma was diagnosed when the lesion was larger than 1 cm in diameter and hyperintense on T1- and T2-weighted images. Small endometrioma was diagnosed when a well-demarcated hyperintense lesion less than 1 cm in diameter was seen on T1-weighted or fat-saturated T1-weighted images. Surgery performed after MR imaging revealed a normal pelvis in six patients, endometriosis in 26 (33 large and 19 small endometriomas), and other cystic lesions in three. Conventional T1- and T2-weighted imaging accurately demonstrated 27 of 33 large endometriomas and two of 19 small endometriomas. Fat-saturation T1-weighted imaging in combination with conventional technique accurately demonstrated 30 of 33 large and nine of 19 small endometriomas. Diagnostic accuracy was improved with addition of fat-saturated images, so their use together with conventional images is recommended in assessment of endometriosis.
Adipose Tissue↗
First incidence of multilocular echinococcosis in a race horse in Japan.
Nodular hepatic lesions caused by larval Echinococcus multilocularis were found in a four-year-old female thoroughbred race horse born and raised in Hokkaido. Before detection of the infection, the infected animal was transported around Honshu for racing. The present disclosure of hydatidosis in a race horse raises concern over the potential danger of spreading the infection throughout Japan by horses possibly infected in Hokkaido.
Adrenal Glands↗
Hb J-Guantanamo [alpha 2 beta 2 128(H6)Ala-->Asp] found in a Japanese family.
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Adult↗
[Interferon therapy after ablation of Kent bundle for a patient with chronic hepatitis type B complicated with WPW syndrome].
Cardiotoxicity of interferon-alpha or gamma, such as fatal arrhythmia and myocardial infarction, has been reported. Therefore cardiotoxicity of interferon should be seriously considered before administration for patients with a pre-existing heart disease. We treated a patient with chronic active hepatitis type B, coexisted with Wolff-Parkinson-White syndrome, who has had frequent attacks of paroxysmal atrial fibrillation. To prevent the occurrence of fatal arrhythmia with an interferon therapy in this patient, we performed radiofrequency catheter ablation of the Kent bundle. After the successful ablation, we could safely administered recombinant interferon alpha-2b for chronic hepatitis type B.
Adult↗
Phase 1 clinical tests of influenza MDP-virosome vaccine (KD-5382).
MDP-virosome vaccine, which contains haemagglutinin (HA) and neuraminidase (NA) antigens isolated from influenza virus combined with 6-O-(2-tetradecylhexadecanoyl)-N-acetylmuramoyl-L-alanyl-D-isoglutamine) (B30-MDP) and cholesterol was tested, in comparison with a currently used HA vaccine, for immunogenicity and adverse reactions on 77 adult male volunteers. The volunteers were divided into eight groups, and each individual was injected subcutaneously once, or twice at a 4 week interval, in their upper arm with one of seven different MDP-virosome vaccine preparations or with HA vaccine as control. Of the three virus strains used as vaccine antigens, MDP-virosome vaccines induced higher haemagglutination inhibiting (HI) antibody to A/Yamagata/120/86 (H1N1) and A/Fukuoka/C29/86 (H3N2) than did HA vaccine, whereas it induced lower HI antibody to B/Nagasaki/1/87, comparable with that induced by HA vaccine. Regarding local adverse reactions, MDP-virosome vaccinees frequently developed mild local pain, reddening and swelling, which disappeared within 5 days; as regards systemic no adverse reactions, leucocytosis developed among the MDP-virosome vaccines, but no other reactions were observed. The leucocytosis may have been caused by the pharmacoimmunological activity of B30-MDP derivatives.
Acetylmuramyl-Alanyl-Isoglutamine↗
The effects of feed intake and purified cellulose on the endogenous ileal amino acid flow in growing pigs.
The effects of level of feed intake (0.8, 1.2 and 1.6 kg/d) and body-weight of the pig (49 and 92 kg) in Expt 1, and dietary neutral-detergent fibre (NDF; 30, 60, 90, 120 and 150 g/kg) in Expt 2 on the endogenous ileal flow of amino acids (AA) and nitrogen were studied with protein-free diets into which purified wood cellulose was incorporated at the expense of maize starch. In Expt 1, one of the protein-free diets containing 90 g NDF/kg was used. Female pigs were fitted with a simple 'T' cannula at the terminal ileum. In Expt 1, the endogenous ileal AA and N flow, expressed as g/kg dry matter (DM) intake, decreased significantly (P < 0.05) with increasing DM intake, except for proline. By contrast, the values expressed as g/d remained constant. There was no significant difference in endogenous ileal flow (P > 0.05) between initial body-weights of 45 and 90 kg except for histidine, isoleucine, phenylalanine, threonine, valine and serine, in which the ileal flow determined at the higher body-weight was significantly higher (P < 0.05). In Expt 2, the effects of dietary cellulose levels on the endogenous ileal flow of AA and N were not significant (P > 0.05), although the values tended to increase as dietary cellulose levels increased for most AA and for N. It is concluded that the daily endogenous ileal flow of AA and N remains relatively similar at different DM intake and cellulose levels. Therefore, correction of apparent ileal digestibility of AA and N to the true ileal digestibility should be made with the endogenous ileal flow values expressed on a daily amount basis, not the values expressed on a DM intake basis.
Amino Acids↗