Search PubMed⌕ Search

Biomedical subjects

Y Hirano

Publications and source records attributed to Y Hirano.

At least 217 records · Page 12Linked to original sources
PubMed1990

[A case of Hurst's encephalitis complicated by hepatoma].

The patient, a 29-year-old female, was hospitalized because of clouding of consciousness, fever and right hemiplegia 4 days after the onset. On first examination she was found having fever in the 37 degree range, positive CRP, hepatomegaly, anemia and hepatic function impairment. Neurological examination revealed somnolence, conjugate deviation to the left and stiff neck. The muscular power measured about 3+ for the upper extremities and 0 for the lower extremities. Babinski sign was present on the right side. The spinal fluid showed an increase in cell counts, especially the neutrophil count. CT scans showed diffuse white-matter hypodensity in the left hemisphere. Soon after admission the patient fell into coma and died 6 days after admission. Autopsies led to a diagnosis of Hurst's encephalitis complicated by hepatoma with liver cirrhosis. It was reported that the immune complex was found in 25.9% of liver cirrhosis patients. From this fact it is suggested that Hurst's encephalitis might be elicited by some immunological mechanism.

Acute Disease↗
PubMed1990

[An epidemiological study on relationship between life style and colorectal cancer].

In Kumamoto prefecture, 2,359 cases were diagnosed as colorectal cancer and operated in 5 years from 1983 to 1987. Their records were analysed to determine the annual incidences in the cecum, ascending, transverse, descending, sigmoid colon and rectum. The female age-adjusted mortality from cancer of the cecum and ascending colon was slightly surpassed that of the male's. While the incidences of colonic and rectal cancer were 21.0 per 100,000 in 1983, they have increased to 26.0 per 100,000 in 1987. As for the crude mortality, it was 11.5 per 100,000 in 1983 and 13.5 per 100,000 in 1987 respectively. Increasing of the incidence was greatest in people over 50 years of age.

Adult↗
PubMed1990

Morphologic studies of sickle erythrocytes by image analysis.

An automated image analysis system was used to characterize the morphology of sickle cells under hypoxic conditions. Images observed by light microscopy were transferred to the image analysis system and were processed to binary (black and white) images, and were then analyzed by area, perimeter, and shape. A circular shape factor (CSF = 4 pi X[area]/[perimeter]2) was found to be useful for elucidating the degree of deformation, but it could not differentiate elongated sickle cells from maple leaf-shaped cells. By combining an elliptical shape factor (ESF = [short axis]/[long axis]) with CSF we could separate deoxygenated homozygous sickle red cells (SS cells) into several morphologically distinct groups, including non-sickled cells, maple leaf-shaped cells, and elongated sickle cells. Using this automated image analysis system, we studied morphologic changes of SS cells exposed to deoxygenation-oxygenation (d-o) cycles between PO2 of 0 and 100 mm Hg (one cycle = 12 minutes) at pHs of 6.9 and 7.4. We found that at both pHs the morphology of sickled cells after the first deoxygenation was predominantly maple leaf-shaped. The number of elongated sickled cells increased as the number of d-o cycles increased, indicating that SS cells changed from maple leaf morphology to classic elongated sickle shape during d-o cycles. Desickling occurred less during the oxygenation phase at pH 6.9 than at pH 7.4 and as the number of d-o cycles increased. These results suggest that during d-o cycles deoxyhemoglobin S fibers may align to form large bundles that do not depolymerize completely even at the arterial oxygen pressure.

Anemia, Sickle Cell↗
PubMed1989

[Focal sparing around the gallbladder in fatty liver: an useful sign in the diagnosis of borderline cases by CT].

The role of CT in the diagnosis of fatty liver is well established. CT has been proved to be a useful noninvasive tool for the demonstration of fatty infiltration of the liver. The characteristic finding is a diffuse decrease in the attenuation within the liver compared with that of the spleen. Commonly, fatty infiltration of the liver is generalized and both CT scans and sonograms can easily demonstrate changes related to this condition. Sometimes, fatty infiltration of the liver is focal and occasionally, it is generalized with focal sparing of the normal liver tissue creating some problems in the diagnosis. Recently, some reports have mentioned the appearance of a focal sparing area in the generalized fatty liver. We often found a high attenuation region around the gallbladder bed in the fatty liver patients on CT examination. There appears to be some relationship between the high density around the gallbladder area and the fatty liver. A retrospective study was undertaken to evaluate the relationship. In this paper, we presented the CT scans of 57 fatty liver cases and compared them with the CT scans of 50 normal patients to discuss the possible cause of the phenomenon and its usage in the diagnosis of the fatty liver.

Adolescent↗
PubMed1989

Endotoxin-induced hypercoagulability: a possible aggravating factor of alcoholic liver disease.

The present experiments were designed to study the effect of chronic ethanol consumption on endotoxin toxicity. The intravenous injection of endotoxin produced a more pronounced increase of serum AST and ALT activities in chronic ethanol-fed rats, when compared to controls. The activities of hepatic mitochondrial enzymes, succinate dehydrogenase and cytochrome oxidase, were also distinctly decreased by endotoxin treatment in chronic ethanol-fed rats. Consistent with these biochemical alterations, light and electron microscopic examinations revealed severe liver injury after endotoxin injection in chronic ethanol-fed rats. Furthermore, the increase of blood BUN and creatinine levels accompanied by the degeneration of the renal tubulus and slight infiltration of neutrophils into the glomerule were produced by endotoxin treatment and were more conspicuous in chronic ethanol-fed rats than controls. Therefore, the biochemical and histological evidence indicates that endotoxin markedly potentiates organ injury after chronic ethanol consumption. In addition, a more pronounced decrease in blood antithrombin III activity accompanied by an increase in fibrin degradation product level in blood was recognized in chronic ethanol-fed rats receiving endotoxin, when compared to controls receiving endotoxin. This increase of blood fibrin degradation product level correlated well with the decrease of antithrombin III activity (r = -0.6116; p less than 0.005). These findings of blood antithrombin III activity and fibrin degradation product level indicate that the coagulation-fibrinolysis system is more activated by endotoxin treatment after chronic ethanol consumption. Furthermore, the activation of the coagulation-fibrinolysis system was well correlated with biochemical and histological alterations representing hepatorenal involvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗
PubMed1989

Lithocholate in liver tissue with obstructive jaundice.

The existence of tissue-bound lithocholate in liver tissue was first suggested by Nair et al. (Lipids 1988;12:922-929). Since lithocholate is well known to be cholestatic, we investigated whether tissue-bound lithocholate, if present, can be correlated to liver dysfunction in obstructive jaundice. Tissue-bound lithocholate in liver tissues of 7 patients with obstructive jaundice was analyzed using gas chromatography-mass spectrometry-selected ion monitoring. We found no accumulation of lithocholate, including tissue-bound form, indicating that the role of lithocholate in inducing hepatic dysfunction in obstructive jaundice is minimal, if any.

Cholestasis↗
PubMed1989

Inactivation properties of T-type calcium current in canine cardiac Purkinje cells.

The kinetic behavior of T-type Ca2+ current (ICa-T) was studied in canine cardiac Purkinje cells using a single suction-pipette whole-cell voltage clamp method. ICa-T was studied without contamination of conventional L-type Ca2+ current (ICa-L). Ca2+, Sr2+, or Ba2+ were used as the charge carrier. During maintained depolarization ICa-T decayed rapidly, and under most conditions the decay showed a voltage-dependent single exponential time course that did not depend on the species of charge carrier. The development of inactivation did not depend on Ca2+, but the time course required more than a single exponential process. Just negative to the threshold voltage for activating ICa-T, inactivation slowly developed and there was a delay in its onset. The time course of recovery from inactivation was dependent on the protocol used to measure it. As the duration of an inactivating voltage step was increased, recovery slowed markedly and there was a delay in its onset. The time course of recovery could be fit as a biexponential. The fast and slow time constants of recovery were relatively constant, however, the relative amplitudes were dependent on the duration of the inactivating voltage step. Recovery was not dependent on Ca2+, and it was slower at a less negative voltage. These results suggest that the T-type Ca2+ channel in cardiac Purkinje cells follows a complex kinetic scheme dependent only on voltage. This behavior can be accounted for by incorporating into a Markovian model several inactivated and closed states.

Animals↗
PubMed1989

Aggressive infantile fibromatosis of the submandibular region.

Aggressive infantile fibromatosis is an unusual, tumor-like, proliferative lesion which grows infiltratively. The clinical and histological features of aggressive infantile fibromatosis in the submandibular region of a 3-year-old girl are reported.

Child, Preschool↗
PubMed1989

Characteristics of L- and T-type Ca2+ currents in canine cardiac Purkinje cells.

Two types of Ca2+ currents were recorded in single dialyzed canine cardiac Purkinje cells using a whole cell voltage clamp technique. T-type current was easily separated from L-type current, because its voltage dependence of inactivation and activation was more negative and it decayed rapidly. L-type current was available at more depolarized holding potentials, activated at more positive voltages, and decayed slowly. In 2 mM extracellular Ca2+ concentration [( Ca]o), the average peak T- and L-type current density was 1.70 and 2.87 pA/pF, respectively. T-type current was relatively insensitive to modification by Ca2+, nifedipine, Cd2+, BAY K 8644, or isoproterenol. T-type current was more sensitive to block by Ni2+ and amiloride. Replacement of Ca2+ by Ba2+ or Sr2+ did not increase T-type current. Changes in the Ca2+ or Ba2+ concentration caused parallel shifts in the voltage dependence of several kinetic parameters for L- and T-type current. In 2 mM [Ca]o, the V1/2 (Boltzmann fit) for inactivation of T-type current was -68 mV with a slope of 3.9, and for L-type current the V1/2 was -31 mV with a slope of 5.5. Recovery from inactivation of L- and T-type current was voltage dependent, and for similar conditions L-type current recovered from inactivation more rapidly than T-type current. These findings show that T- and L-type currents are large in cardiac Purkinje cells, and they can easily be separated by their voltage, kinetic, and pharmacological differences. Both may have important physiological roles.

Animals↗
PubMed1989

Amantadine-induced afterpotentials and automaticity in guinea pig ventricular myocytes.

The ionic mechanisms of amantadine-induced changes in membrane potential and automatic activity in guinea pig ventricular myocytes were studied using the suction-pipette whole-cell clamp method. While 25-100 microM amantadine decreased the action potential amplitude and duration, 200 and 400 microM amantadine lengthened the action potential duration and decreased the maximum diastolic potential with an appearance of diastolic depolarization and automaticity. In the presence of 25-100 microM amantadine, the preparations developed an afterpotential due to incomplete repolarization and a delayed afterdepolarization that eventually brought about triggered automaticity. The former type of afterpotential was abolished by tetrodotoxin (TTX) and the latter by Co2+. Spontaneous activity from the diastolic depolarization was also abolished by Co2+ but not by Cs+. Amantadine suppressed the calcium current to as much as half of the control at the concentrations used (25-200 microM). The drug also produced a depression of the inward rectifier K+ current. The outward current showing time-dependent decay was activated at the plateau voltages by concentrations lower than 100 microM, whereas the delayed outward K+ current was depressed by the drug in a concentration-dependent manner at more positive potentials. Amantadine activated the TTX-sensitive and TTX-insensitive inward currents on repolarization from depolarized states, without producing the transient inward current. These results indicate that the amantadine-induced diastolic depolarization and afterpotentials are caused by changes in multiple ionic currents and that, therefore, the drug can be used as a unique model for the study of arrhythmogenesis.

Amantadine↗
PubMed1989

A possible mechanism of fever induced by Nocardia rubra cell wall skeleton (N-CWS) in experimental animals.

The characteristics of fever elicited by the cell wall skeleton of Nocardia rubra (N-CWS) and by lipopolysaccharide (LPS) were compared in rabbits, and the possible involvement of the antigenicity of N-CWS was investigated in guinea pigs. In rabbits, fever of more than 0.5 degree C developed after an intravenous (i.v.) injection of 10 micrograms/kg or more of N-CWS, and was monophasic with 30-100 micrograms/kg but biphasic with the highest dose of 300 micrograms/kg. LPS elicited fever with similar characteristics at doses of 0.01-0.1 microgram/kg. With both compounds, the fever was inhibited by indomethacin. Tolerance to N-CWS and LPS appeared after dosing with 30 or 0.1 micrograms/kg, respectively for 10 d. In guinea pigs sensitized with N-CWS, challenge with 1 or 10 micrograms/kg of N-CWS 10 d later, which did not induce fever in the nonsensitized animals, caused fever of more than 0.5 degree C, and delayed-type hypersensitivity (DTH) appeared. N-CWS also elicited fever in nonsensitized guinea pigs bearing N-CWS-sensitized lymphocytes or anti-N-CWS antibody; the fever was higher in the guinea pigs sensitized with the lymphocytes than in those with the anti-N-CWS antibody. In brief, single injections of N-CWS and of LPS elicited fever with similar characteristics, although the potency of N-CWS was weaker. With N-CWS, the fever is proposed to be triggered by the antigenicity of the compound itself, because doses as low as 1 or 10 micrograms/kg elicited fever along with immunological response in N-CWS-sensitized animals, but not in nonsensitized ones.

Animals↗
PubMed1989

Possible involvement of a tumor necrosis factor (TNF)-like mediator as an endogenous pyrogen in fever induction by Nocardia rubra cell wall skeleton (N-CWS).

Tumor necrosis factor (TNF), a cytokine produced in macrophages, also acts as an endogenous pyrogen (EP). To investigate whether TNF has a role in the fever induced by Nocardia rubra cell wall skeleton (N-CWS), the relationship between fever and TNF production was studied in guinea pigs. N-CWS injected i.v. to guinea pigs caused biphasic fever and had L-929 cell-killing activity which resembled that of TNF in the sera 30 min before the first phase of fever appeared. In vitro, L-929 cell-killing activity was demonstrated in the culture supernatant of guinea pig peritoneal macrophages pretreated with N-CWS, and the activity increased dependently on N-CWS concentration or culture duration. When the supernatant of the macrophages was fractionated by gel filtration and each fraction was assayed for fever-inducing and L-929 cell-killing activities, the fraction with the cell-killing activity also induced fever with characteristics similar to that by i.v. injection of N-CWS in guinea pigs. These results suggest that TNF acts as an EP on the fever induced by N-CWS in guinea pigs.

Animals↗
PubMed1989

A morphometric right-left comparison of the cat olfactory bulb.

The brain weight, sizes (length, width and height) and thickness of cell strata of the olfactory bulb (OB) were measured in the cat weighing 2.3 to 4.8 kg. There was a significant correlation between the brain weight and the body weight. The OB size did not correlate significantly with the body weight, but only the width of the OB with the brain weight. Comparison of the right and left OBs showed that there was no significant difference between them in regard to the size and thickness of cell strata in the cat used in the present experiment.

Animals↗
PubMed1989

[Dramatic effects of high-dose intravenous gammaglobulin in each patient with intractable dermatomyositis and polymyositis].

A high-dose intravenous gamma-globulin (IVGG) therapy was given to two children; one with intractable dermatomyositis (case 1) and the other with polymyositis (case 2). Case 1, a 3-year-6-month-old girl, only poorly responded to the standard oral prednisolone therapy and a pulse therapy with high-dose methyl-prednisolone. This patient showed a complete remission after a course IVGG therapy, 100 mg/kg/day iv. for 5 days, which has been maintained for 6 months up to the present. Case 2, a 13-year-6-month-old girl, also showed little improvement after the oral prednisolone therapy, and transient improvement during plasma exchange therapy. This patient showed fairly good response after three repeated courses of IVGG therapy, but not complete remission.

Adolescent↗