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Biomedical subjects

A Arita

Publications and source records attributed to A Arita.

15 recordsLinked to original sources
PubMed1997

[Laminin-dependent growth arrest of human hepatic carcinoma cell line, HuH-7, in association with expression of p21/WAF-1 protein].

Laminin-overlay to the culture of a human hepatocellular carcinoma cell line, HuH-7, resulted in changes in the cell behavior; suppression of the cell growth, conversion of the cell morphology, and the elevated secretion of cellular AFP in the culture medium, implying that the cells had undergone apparent differentiation in vitro. Together with the behavioral changes, the cells showed positive immunohistochemical staining of the anti-p 21/WAF 1 antibody over the cell nucleus and the amount of p 21/WAF-1 proteins was increased in the cells. p53 protein was detected both in the control cells and the cells with the laminin overlay. These findings indicate that the laminin-dependent changes in the cell behavior are closely associated with the activation of the cyclin-dependent kinase inhibitor, p 21/WAF-1, and that? is uncoupled with the p 53 expression.

Carcinoma, Hepatocellular↗
PubMed1995

Heterotopic gastric mucosa of the gallbladder.

A case of heterotopic gastric mucosa in the fundus of the gallbladder is reported. A 23-year-old man, who had been healthy and asymptomatic, visited our hospital because of abnormal findings in a liver enzyme test given during a routine health screening. Ultrasonography demonstrated a highly echogenic polypoid mass in the fundus of the gallbladder. The gallbladder mass was confirmed by both computed tomography and intravenous cholangiogram. After a 10-month follow up, laparoscopic cholecystectomy was performed. Intraoperative touch smear cytology of this lesion revealed class II cells. The surgical specimen revealed a 15 x 10 x 5 mm polypoid lesion in the fundus, with no gallstones in the gallbladder. Histologically, the polypoid lesion consisted of both fundic type and pyloric type gastric glands located in the mucosa of the gallbladder. In the literature, 42 cases of heterotopic gastric mucosa of the gallbladder have been reported, only 3 of which, including this present case, were found incidentally, with no apparent symptoms.

Adult↗
PubMed1995

Adenomyoma of the common hepatic duct.

A very rare case of adenomyoma of the common hepatic duct is described. A 54-year-old woman was admitted with impending obstructive jaundice secondary to adenomyoma of the common hepatic duct. Our impression, formulated from her clinical presentation, endoscopic investigations, and biochemical and radiological findings, was a cancer of the proximal common hepatic duct. The patient was treated successfully by combination surgical resection and hepaticojejunostomy. Despite our obtaining an intraoperative frozen section, final histological examination was required to confirm the diagnosis. The patient remains well 16 months postoperatively. A survey of the world literature revealed that this is the second report of adenomyoma occurring in the common hepatic duct.

Adenomyoma↗
PubMed1985

[Acute respiratory failure based on liver dysfunction in canine liver ischemia model].

From the analysis of 182 consecutive surgical patients who underwent hepatectomy and/or were associated with liver cirrhosis during 1963-1982, acute respiratory failure was proved to be so much often in those patients. The case rate of this complication tends to increase according to resected size of liver tissue and severity of liver cirrhosis. Those cases showed clinical signs of pulmonary interstitial edema and were often associated with coagulopathy and endotoxemia. In order to clarify the pathophysiological mechanism of the acute respiratory failure based on liver dysfunction, a canine experimental model in which blood inflow into the liver was completely blocked was newly devised, and respiratory state in this model was analysed. The following results were obtained. The increase of EVLW (extravascular lung water) measured by modified double indicator dilution method was linear to the increase of PWP (pulmonary wedge pressure) in both liver failure group and control group. But the coefficient of the regression line was three times larger in the former group than in the latter. It suggests that permeability of pulmonary capillary was highly increased in liver failure group. All dogs with liver failure showed typical symptomes of lung edema at maximal PWP. Disseminated intravascular coagulation, consumption of neutrophils, decrease of CH50 and serum opsonin were thought to be mediators of the increase of lung vascular permeability. Steroid and PGI2 blocked the increase of the lung vascular permeability completely but not the increase of lung vascular resistance in this experimental model.

Acute Disease↗
PubMed1982

Hyperpolarizing responses in the soma of crayfish median giant fiber.

Hyperpolarizing responses of the somata of median giant fibers of crayfish were investigated under current clamp and voltage clamp conditions in normal saline. The responses consisted of a peak [mean delta Vm (peak)=-217 mV] followed by a plateau (-107 mV), and could be classified into N-type and G-type. In the N-type cells, the current clamp I-V curve showed a transient phase to the peak. The phase corresponded to the negative slope region of the voltage clamp I-V curve. There was no negative slope region in the G-type cells. In the transient and the peak phases, the instantaneous I-V curves showed nonlinearity, and the shifts of the electromotive forces (delta EMF) from the resting level were slightly negative or zero. In the plateau phase, however, the instantaneous I-V curve was linear and delta EMF was large and positive (33.2 mV). The membrane resistance, which was larger (X2.3) at the peak than at the resting state, decreased (X0.23) gradually during the plateau phase. delta EMF during the hyperpolarizing response consisted of two components: a fast component (1.7 msec) and a slow one (113 msec). The amplitudes of delta EMF (27.4 mV) of these components in the depolarizing direction increased gradually, once the response had reached the peak. The fast and slow delta EMF's attained 17.0 and 10.4 mV respectively at the end of 100 msec current pulse. It is shown that constant charge triggers the plateau process and that this threshold voltage-current curve is hyperbolic. It is a possibility that the plateau is caused by membrane breakdown.

Animals↗
PubMed1979

Impedance changes during the electrical and mechanical activities of a bullfrog heart.

Electrical impedance of a bullfrog ventricle was recorded epicardially by the V-I method and the bridge method together with an electrocardiogram (ECG) and a contraction curve, in terms of shortening. Impedance change during one cardiac cycle of a contracting ventricle corresponded completely to the contraction curve in its time course: impedance decreased during systole and attained minimum at the peak of contraction, and the durations of both curves were almost identical. The ratio of impedance just before T-wave to that just after R-wave ([ZT]/[ZR]) of an in situ heart was increased when the ventricle contracted isovolumetrically by means of mineral oil: the ratio was far less than 1.0 in control ventricle, while it was more than 1.0 in oil-filled one (2/3 cases). Upon isometric condition or treatment of cadmium the motion restricted ventricle caused an increase in the impedance ratio ([ZT]/[ZR]) to higher than 1.0, as in the case of oil-filled ventricle. The epicardial recording of ventricular impedance seems to consist of two components: contraction(shortening-dependent impedance change, which reflects the membrane activity. Vigorous contraction will probably mask the latter and reveal only the former.

Animals↗
PubMed1978

Cadmium-induced decrease in the outer facing skin resistance of a bullfrog (Rana catesbeiana).

Effects of cadmium on the electrical properties of frog skin were investigated by using the microelectrode technique. The epidermal application of 2 mM Cd for 5 min increased both the short circuit current and the skin potential, and decreased the skin resistance (RM). Cadmium also decreased intracellular potential with reference to the epidermal solution (PDi) and the electrical resistance between the epidermal solution and the tip of a microelectrode (RM1) located in the stratum germinativum. deltaRM that is RM,Cd-RM, control seemed to approximately coincide with deltaRM1 which is RM1,Cd-RM1,control. Comparing with our previous results, i.e., Cd decreased RNa (the resistance to the active Na current) and increased Rsigma (the resistance to the passive ions) but did not altered ENa (the electromotive force of active Na current) in the later stage (15 min or later). Cd seemed to decrease the RNa component at the epidermal side of the skin in the early stage (less than 5 min).

Animals↗
PubMed1977

Effects of cadmium on the active transport of sodium by the abdominal skin of a bullfrog (Rana catesbeiana).

Effects of Cd on the active transport of Na in SO4-Ringer's solution on the abdominal skin of a bullfrog (Rana catesbeiana) were investigated. The short circuit current (SCC), potential difference (PD), and Na flux were determined. The skin resistance (Rm), the electromotive force of active Na transport (Ena), and the resistance to the active Na current (Rna) were calculated from the measured data. The application of Cd to the epidermal side at 2 mM was more effective in increasing SCC than that to the dermal side at the same concentration. The time course of changes in SCC induced by Cd were classified into three types: (I) a simple increase in SCC during Cd application, (II) an early decrease followed by an increase in SCC, and (III) a decrease in SCC except for a small increase in the initial short period. Type I response was observed in the majority of cases (about two-thirds). Types II and III were observed in 7 and 32 percent of 28 cases, respectively. The Cd-induced changes in SCC were analyzed on the basis of changes in ENa and RNa. In Type I, the increase in SCC was due to a remarkable decrease in RNa without an appreciable change in ENa (since SCC = ENa/RNa). In Types II and III, the changes in SCC in the early and the later stages could be explained by the differences in the extents to which ENa and RNa decreased. The experimental and calculated ratios of PDcd to PDcontrol in these stages were in good agreement with each other.

Abdominal Muscles↗