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Biomedical subjects

K Obara

Publications and source records attributed to K Obara.

At least 127 records · Page 7Linked to original sources
PubMed1992

[Supralevator pelvic exenteration with simultaneous bowel and urinary reconstruction. Two case reports].

Two male patients underwent supralevator pelvic exenteration, preserving their normal voiding and evacuating function. Case 1 was a 19-year-old man with pineal region tumor, and a metastatic lesion in the bottom of the rectovesical pouch, possibly through the ventriculo-peritoneal shunt. Following supralevator pelvic exenteration, the construction of double pouches, a colonic J pouch and Mainz pouch to the urethra, were performed. Case 2 was a 39-year-old man with bulky retrovesical tumor. He underwent supralevator pelvic exenteration by sigmoid colo-proctostomy and U-pouch to the urethra. Both patients achieved continent except for urinary leakage at night and were able to defecate and urinate voluntarily. Urodynamic study revealed that the pressure in their urinary pouches was low.

Adult↗
PubMed1991

Calyculin A increases voltage-dependent inward current in smooth muscle cells isolated from guinea pig taenia coli.

The effects of a potent phosphatase inhibitor, calyculin A (CL-A), on inward currents in guinea pig taenia coli smooth muscle cells were examined. CL-A increased the inward current, and this effect of CL-A was inhibited by a protein kinase C inhibitor, H-7, and by nifedipine. Phorbol 12,13-dibutyrate, an activator of protein kinase C, also increased the inward current and this effect was antagonized by H-7. These results suggest that in guinea pig taenia coli smooth muscle cells CL-A may facilitate the opening of the L-type Ca2+ channels through the protein kinase C-dependent phosphorylation system.

Animals↗
PubMed1991

Prediction of the recurrence of esophageal varices based on portal vein pressure and oxygen tension in portal and peripheral blood.

In 27 variceal patients completely treated by ethanolamine oleate and polidocanol and followed for more than one year, the recurrence of varices was studied by measuring portal vein pressure and oxygen tension in the portal vein and peripheral arteries and veins before and after EIS. Frequent recurrence was observed in patients with increased PVP after EIS and lower or inverse PVO2-VO2 tension after EIS. The recurrence of varices after EIS may thus possibly be predicted based on portal vein pressure and PVO2-VO2 tension differences.

Esophageal and Gastric Varices↗
PubMed1991

[A case of mixed connective tissue disease (MCTD) associated with transverse myelitis responding to pulse therapy].

A 42-year-old female was admitted to our hospital on October 1, 1990 because of one week history of back pain, weakness of her right lower extremity and sensory disturbance of her left lower extremity. Physical examination revealed swollen hands, Raynaud's phenomenon, sclerodactyly and heliotrope rash. The body temperature was 37.0 degrees C. Neurological findings included weakness in the right lower extremity, left hypalgesia and thermohypesthesia below Th4, hyperreflexia on the right lower extremity and right extensive plantar response. Laboratory data showed leucopenia (3,700/mm3) and hypergammaglobulinemia. Serological examination revealed antinuclear antibodies with a titer of 1:5120 (speckled pattern) and anti-RNP antibody with a titer of 1:32. Neither anti-DNA antibody nor anti-Sm antibody were detected. Serum C3 and C4 were normal. The cerebrospinal fluid (CSF) contained mononuclear cells of 5/mm3, protein 29 mg/dl and glucose 56 mg/dl. Queckenstedt test was negative. Treatment with prednisolone 60 mg daily was started. On the 8th day of therapy, she complained of a burning sensation in the back, then paraplegia and urinary retention developed. MRI examination showed a high intensity area of the spinal cord at the right Th4 on T2-weighted images. Next day the treatment with 1000-mg intravenous daily pulse of methylprednisolone for 3 days was started, followed by prednisolone 40 mg daily. After this pulse therapy, the CSF contained mononuclear cells of 52/mm3, protein 34 mg/dl, glucose 67 mg/dl and IgG 7.6 mg/dl. Her neurological manifestation gradually improved and at six weeks after the pulse therapy neurological examination revealed no abnormality except for painful tonic spasm. Prednisolone was slowly tapered to 15 mg daily.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Normal pressure hydrocephalus associated with cauda equina neurinoma.

A 65-year-old woman with normal pressure hydrocephalus experienced improved gait and hydrocephalus following surgical resection of a cauda equina neurinoma. Fibrinogen, detected in the cerebrospinal fluid, may be involved in the pathophysiological process of normal pressure hydrocephalus.

Aged↗
PubMed1990

The destructive effects of sclerosant ethanolamine oleate on mammalian vessel endothelium.

Ethanolamine oleate (EO) used widely in sclerotherapy against esophageal varices was studied for its pharmacological effect on blood coagulation and vascular damage in animals. Blood coagulation was completely inhibited by EO at a concentration of 0.31%. EO destroyed the endothelial cells of the vessel of dog and rat within one minute after injection into the vessels. An accumulation of fibrin and platelets on the surface of the damaged vessel was observed electron microscopically. Mural thrombus was formed in a few hours and the thrombus occluded the blood stream in the vein. From these animal experiment, intravasal injection of EO was considered to cause the disappearance of varices by the following two processes: collapse of varices because of occlusion of the blood stream and shrinking of the obstructed thrombus through organization.

Adult↗
PubMed1990

[Localizing methods of primary hyperparathyroidism and those results].

The results of several pre-operative localizing methods and pathological findings were compared in 11 patients with primary hyperparathyroidism. 1. The accuracy rate was highest with selective blood sampling from the thyroid vein and MRI, which was 75% with both methods. The 3rd was dual photon scintigraphy, the accuracy rate being 62.5%. The 4th was ultrasonography, 57.1%, and the rate was lowest with CT, 25%. 2. MRI-a new localizing method-has a weak point that it cannot differentiate lymph nodes from parathyroid adenoma/hyperplasia. 3. Not to overlook small lesion of primary hyperplasia, several localizing methods should be performed before initial neck exploration.

Adult↗
PubMed1990

[The effect of captopril on proteinuria in glomerular diseases].

We evaluated the efficacy of an ACE inhibitor captopril (CAP) for the reduction of proteinuria in glomerular diseases, and tried to find the conditions in which urinary protein excretion was significantly decreased by this drug. Renin provocation test by CAP (C-test) was performed, and the result was compared to the effect on proteinuria. In 33 patients with proteinuria, ranging from 1.1 to 14.1 g/day, CAP was administered. Urinary protein excretion was reduced from 3.6 +/- 0.6 to 2.8 +/- 0.4 g/day (mean +/- SEM, p less than 0.01) after 2 weeks. The decrease in urinary protein was significant when renal function was moderately impaired (30 less than or equal to Ccr less than 60 ml/min) or patients were on a salt diet less than 7 g of NaCl daily. Reduction of urinary protein excretion by 2-week treatment of CAP was correlated with the result of C-test (r = 0.874, p less than 0.025). The long-term follow up for more than 6 months also suggested that CAP delayed the deterioration of renal function. Thus, CAP was proved effective in treating proteinuria, and C-test might give us an information of its proteinuria-suppressing effect in an individual case. But its efficacy was observed only in patients with moderately-reduced renal function or on low-salt diet. Therefore, we should select the cases carefully to expect the effect of CAP for the reduction of proteinuria.

Adult↗
PubMed1990

Progression of experimental focal glomerulosclerosis in the spontaneously hypertensive rat.

To study the influence of hypertension on the progression of focal glomerulosclerosis (FGS), we produced an experimental model of FGS in spontaneously hypertensive rats (SHRs) by the combined administration of puromycinaminonucleoside (AMNS) and protamine sulfate (PS). SHRs and normotensive Wistar Kyoto rats as a control strain were given daily injections of subcutaneous AMNS (1 mg/100 gm body weight) and intravenous PS (two separated doses of 2.5 mg/100 mg body weight) for 4 days; they were killed on day 80 after three series of injections at 10-day intervals. The levels of urinary protein, serum creatinine, and urea nitrogen in SHRs given AMNS and PS were elevated throughout the experiment and were significantly higher than these levels in other control groups on day 80. Histology in SHRs given AMNS and PS showed advanced FGS associated with glomerular hypertrophy and widespread interstitial fibrosis. Most small arteries and arterioles showed "onion peel" thickening and fibrinoid necrosis of the intima, which is characteristic of malignant arteriosclerosis. We observed that the gradient of glomerulosclerosis increased from superficial to deep cortical zones; this phenomenon had often been reported in human FGS. However, these distinguished lesions were not found in control groups. Therefore, it is suggested that systemic hypertension is one of the deleterious factors enhancing histologic and functional deterioration in FGS.

Animals↗
PubMed1989

Okadaic acid, a phosphatase inhibitor, produces a Ca2+ and calmodulin-independent contraction of smooth muscle.

The effects of okadaic acid, a phosphoprotein phosphatase inhibitor, on the contractile response and on myosin light chain phosphorylation were studied in intact lamb tracheal smooth muscle. The effects of okadaic acid were compared to the response of the same fibers stimulated with 1 microM methacholine, a concentration that induces 90% of maximal force. Okadaic acid (50 microM) produced a slow but maximal contraction that was accompanied by an increase in phosphorylation of the 20 kDa light chain of myosin. The myosin light chain phosphorylation pattern induced by okadaic acid, however, differed from that induced by methacholine. Ca2+ depletion, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), a calmodulin antagonist and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), a protein kinase C inhibitor, blocked or attenuated methacholine-induced contractions but had no significant effect on force development or myosin light chain phosphorylation induced by okadaic acid. These results suggest that phosphorylation of the 20 kDa light chain of myosin is essential for smooth muscle contraction; they also suggest that okadaic acid either uncovers or activates an apparently Ca2+ and calmodulin-independent protein kinase activity that phosphorylates the 20 kDa light chain of myosin at multiple sites.

Animals↗
PubMed1989

Isoproterenol attenuates myosin phosphorylation and contraction of tracheal muscle.

The effects of isoproterenol on isometric force, unloaded shortening velocity, and myosin phosphorylation were examined in thin muscle bundles (0.1-0.2 mm diam) dissected from lamb tracheal smooth muscle. Methacholine (10(-6) M) induced rapid increases in isometric force and in phosphorylation of the 20,000-Da myosin light chain. Myosin phosphorylation remained elevated during steady-state maintenance of isometric force. The shortening velocity peaked at 15 s after stimulation with methacholine and then declined to approximately 45% of the maximal value by 3 min. Isoproterenol pretreatment inhibited methacholine-stimulated myosin light chain phosphorylation, shortening velocity, and force during the early stages of force generation. However, the inhibitory effect of isoproterenol on force and myosin phosphorylation is proportionally greater than that on shortening velocity. Isoproterenol pretreatment also caused a rightward non-parallel shift in the methacholine dose-response curves for both isometric tension and myosin light chain phosphorylation. These data demonstrate that isoproterenol attenuates the contractile properties of airway smooth muscles by affecting the rate and extent of myosin light chain phosphorylation, perhaps through a mechanism that involves the synergistic interaction of myosin light chain kinase phosphorylation and Ca2+ metabolism.

Animals↗