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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 415 records · Page 23Linked to original sources
PubMed1994

[Clinical features of passed calcium oxalate monohydrate and dihydrate stones].

105 calcium oxalate stones (calcium oxalate content greater than calcium phosphate) which were passed spontaneously from 1983 to 1988 were studied by infrared analysis and divided into 51 COM stones and 54 COD stones according to the content of calcium oxalate monohydrate (COM) and dihydrate (COD). The appearance and consistency of 11 COM stones (21.6%) were like those of the typical COD stone, although the dark brown, firm core suggesting the typical COM stone was found in 3 COD stones (5.6%). The content of calcium phosphate was higher in COD stones than in COM stones (P < 0.01). There was no significant difference between the weights of 51 COM and 54 COD stones. However, regarding 73 stones < 100 mg in weight, COD stones were heavier than COM stones (p < 0.05); 48.0 +/- 23.8 and 35.4 +/- 23.2 mg (mean +/- standard deviation) for 38 COD and 35 COM stones respectively. COM stones were found in older patients than COD stones (p < 0.05); 45.2 +/- 12.8 and 39.9 +/- 11.2 years old for 51 COM stone patients and 54 COD stone patients. There was no significant difference in the sex distribution and the number of patients with a history of stone(s) between COM and COD stone patients. Fifty-three patients were followed at yearly intervals without any prophylactic treatment for stone recurrence. The follow up periods were 37.6 +/- 27.1 and 32.1 +/- 20.9 mos. for 25 COM and 28 COM stone patients respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[The early lesions of renal amyloidosis].

Two patients with minimal amyloid deposition in association with nephrotic syndrome are reported. Since the amyloid deposits in each renal biopsy specimen were inconspicuous, both were first thought to be minimal glomerular changes. A few widely scattered, silver-positive, epimembranous spicules were found on careful reexamination by light microscopy. Congo red stain and electron microscopy confirmed the presence of small glomerular amyloid deposits and amyloid fibrils. Furthermore, immuno-fluorescence microscopy showed partial IgA deposits in the mesangial area and capillary wall. We therefore urge careful examination to detect amyloid deposits of all kidney biopsy specimens of minor glomerular abnormalities, or glomerulonephritis with IgA deposits from elderly patients with nephrotic syndrome. Light microscopy of Congo-red-stained sections and electron microscopy of the fibrillar structure very useful for the detection of small amyloid deposits.

Adult↗
PubMed1994

Suppression of graft rejection in rat keratoepithelioplasty by anterior chamber inoculation of donor lymphocytes.

A newly developed model of keratoepithelioplasty (KEP) in the rat was used to analyze the effect of anterior chamber-associated immune deviation on the suppression of corneal allograft rejection. The right eyes of Fisher rats received an anterior chamber (AC) injection of lymphocyte suspension from Dark Agouti (DA) rats (DAL group) or phosphate-buffered saline (positive control group). Seven days later, DA corneal lenticules were grafted onto both eyes of the recipients. Delayed type hypersensitivity (DTH) was also assessed in another group of Fisher rats receiving an AC injection of DA lymphocytes in the right eye. Within 15 days, 88% of the eyes in the positive control group demonstrated vigorous epithelial edema, a large area of epithelial defect, and vascularization. By contrast, in the DAL group, only 37% of the eyes showed slight epithelial edema, a small area of epithelial defect, and rare vascularization; suppression of graft rejection was observed in both eyes. DTH assay demonstrated significant suppression in the recipients of the AC injection of donor-type lymphocytes. This study indicates that the AC injection of donor-type lymphocytes prior to corneal grafting suppresses allograft rejection in the rat KEP model, correlative with the suppression of DTH reaction.

Animals↗
PubMed1994

[A case of carcinomatous meningitis from transitional cell carcinoma of the urinary bladder].

We report a case of carcinomatous meningitis from transitional cell carcinoma of the urinary bladder. A 70-year-old man with invasive bladder cancer and multiple pulmonary metastases received 3 courses of systemic M-VAC (methotrexate, vinblastine, doxorubicin, and cisplatin) chemotherapy, after which the primary tumor and pulmonary metastases diminished in size and number. During the 4th course of chemotherapy, he complained of nausea, headache, diplopia, and neck stiffness. Computer tomographic (CT) scan of the brain showed no evidence of parenchymal metastases, cerebral hemorrhage, or infarction. Cerebrospinal fluid examination revealed an increase in cells along with elevated protein and depressed glucose concentrations, but no malignant cells were identified. He died two weeks after the onset of neurological symptoms. Autopsy revealed numerous tiny metastatic lesions in the leptomeninx, so called carcinomatous meningitis, without parenchymal metastases in the brain. Although metastases to the central nervous system from transitional cell carcinoma of the bladder, especially carcinomatous meningitis rarely have been reported, this unusual complication will be seen more frequently with the development of more effective systemic chemotherapy such as M-VAC.

Aged↗
PubMed1994

Hepatic resection under the intermittent selective portal branch occlusion by balloon catheter.

BACKGROUND: In hepatic resection, it is important to control intrahepatic blood flow to minimize blood loss. Intermittent and selective vascular occlusion, if possible, are advisable. STUDY DESIGN: For this purpose, we created the double balloon catheter, which when introduced into a lobar or a smaller branch of the intrahepatic portal vein through a branch of the ileocolic vein, made it possible to occlude these branches temporarily during hepatic resection. The small balloon located at the tip of the catheter made it easy to introduce the catheter to the portal branch selectively, under the guidance of ultrasonography. Another balloon was inflated intermittently to occlude selective portal blood flow. Using this technique, hepatic resection was achieved in 18 consecutive patients: 13 with hepatocellular carcinomas (11 with cirrhosis, two with chronic hepatitis), one with cholangiocellular carcinoma, three with metastatic carcinomas, and one with intrahepatic calculi. RESULTS: In these cases, 19 hepatic resections were performed; two left hepatectomies, one extended right hepatectomy, one right hepatectomy, six segmentectomies, eight subsegmentectomies, and one partial hepatectomy. In each case, well demarcated hepatic tissue delineated by ischemic change was removed with minimal bleeding and little impairment to the residual hepatic tissue, resulting in a good postoperative course. CONCLUSIONS: This double balloon catheter can replace the dissection of the hepatoduodenal ligament for hepatic resection, which causes bleeding, especially in patients with cirrhosis, and results in less cell injury of the residual hepatic parenchyma.

Aged↗
PubMed1994

Pharmacological properties of the new stable prostacyclin analogue 3-Oxa-methano-prostaglandin I.

The pharmacological characteristics of the 3-oxamethano-prostaglandin I1 compound (+)-methyl [2-[(2R,3aS,4R,5R,6aS)-octahydro-5-hydroxy-4- [(E)-(3S,5S)-3-hydroxy-5-methyl-1-nonenyl]-2-pentalenyl]etho xy] acetate (SM-10902, CAS 139403-31-9), a novel stable analogue of prostacyclin and its free acid, SM-10906, were studied. SM-10902 was rapidly deesterified to its free acid in rabbit and human serum. SM-10902 and SM-10906 exhibited antiplatelet potency against ADP-induced aggregation in rabbit and human platelets. In the presence of diisopropyl fluorophosphate, an esterase inhibitor, the antiplatelet activity of SM-10902 was markedly reduced, to much less than that of SM-10906. SM-10906 inhibited platelet aggregation induced by various inducers in several species and enhanced the cyclic AMP (cAMP) level in human platelets. These activities were nearly equal to those of prostaglandin (PG) E1 and less than those of PGI2. SM-10906 relaxed isolated rabbit mesenteric and bovine coronary arteries, and elevated the cAMP level in bovine coronary arteries. SM-10906 given intravenously exhibited a sustained reduction in blood pressure based on vasodilation in ganglion-blocked, angiotensin II-supported rats. SM-10902 applied to the guinea-pig auricles increased the skin temperature, but SM-10906 and PGI2 showed no such effect. In conclusion, SM-10902, which is considered to be a prodrug of SM-10906, was suggested to exert its anti-platelet and vasodilator activities through the increase of cAMP. Since SM-10902 penetrates well into the skin, it may be useful as an external preparation to improve peripheral circulatory insufficiency.

Adenylyl Cyclase Inhibitors↗
PubMed1994

[Squamous carcinoma with pseudosarcomatous stroma of the renal pelvis and ureter: a case report].

A case of unusual tumor of renal pelvis and ureter is reported. A 82-year-old man was admitted with the chief complaint of gross hematuria. He was diagnosed with bladder tumor and right renal pelvic and ureter tumor by bladder biopsy (TCC G2) and radiological examinations. Right nephroureterectomy was performed after transurethral resection of bladder tumor (TUR-Bt). Histological findings of renal pelvic and ureteral tumor were squamous carcinoma with pseudosarcomatous stroma (so-called carcinosarcoma). Tumor cells showed mostly a sarcomatoid spindle pattern and partly apparent SCC. He was discharged without adjuvant therapy and no recurrence was found for 7 months after operation. In our case, CA19-9 was useful as a tumor marker. Such disease has been confused with true carcinosarcoma or sarcomatoid carcinoma and should be distinguished from them. We reviewed 18 case reports of true carcinosarcoma or sarcomatoid carcinoma of the renal pelvis.

Aged↗
PubMed1994

[Ruptured anterior communicating artery aneurysm associated with inter-optic course of anterior cerebral artery: report of a case and review of the literature].

We report a ruptured anterior communicating artery (ACoA) aneurysm in a patient whose anterior cerebral artery (ACA) arose from the left C3 portion and ascended between the optic nerves. A 50 year-old woman was admitted to our department with complaints of headache and vomiting. CT scan showed thick subarachnoid hemorrhage. Left carotid angiography revealed a saccular aneurysm of the anterior communicating artery and an abnormal vessel which arose from the left C3 portion and terminated in the territory of the ACoA. Surgery was performed about eight hours after subarachnoid hemorrhage. The abnormal vessel was identified as it ascended between the optic nerves. There are only 25 reported cases of this abnormality including our own case. The right carotid artery was the most frequent origin of the abnormal artery (18 cases). 13 aneurysms were associated in 11 cases, in which seven were located in the anterior communicating artery. It was the most frequent site of the aneurysm. There were various explanations for this anomalous ACA. Because of the angiographical and operative findings, we prefer to use "inter-optic course of ACA" as the medical terminology better suited to describe this condition.

Aneurysm, Ruptured↗
PubMed1993

Evidence that peritoneal exudate cells cultured with eye-derived fluids are the proximate antigen-presenting cells in immune deviation of the ocular type.

Immune privilege in the anterior chamber of the eye results in part from a selective deficit in delayed hypersensitivity that is elicited by antigenic materials placed in this unique tissue site. This distinctive systemic immune response to intraocular Ag (termed anterior chamber-associated immune deviation, ACAID) is fashioned by indigenous, intraocular bone marrow-derived cells that capture Ag within the anterior chamber and carry an Ag-specific ACAID-inducing signal via the blood directly to the spleen. An identical form of immune deviation can be evoked by the i.v. injection of peritoneal exudate cells (PEC) pulsed in vitro with soluble Ag in the presence of transforming growth factor-beta (TGF-beta). To determine whether eye-derived cells present Ag directly to responding splenic T cells or merely serve as vehicles to deliver Ag to the spleen, we have conducted MHC restriction experiments with PEC donors and recipients selected to differ at loci dictating MHC and/or minor histocompatibility Ag. When PEC were pulsed in vitro with soluble Ag (BSA) in the presence of culture fluid containing TGF-beta and injected into recipients with which they shared either class I or class II MHC molecules, BSA-specific ACAID was induced. By contrast, PEC pulsed with BSA and TGF-beta-containing culture fluid failed to induce ACAID when the cells were injected into recipients who were completely histoincompatible or were identical with the injected cells only at non-MHC loci. Using MHC class I-deficient transgenic mice, it was determined that intraocular injection of BSA failed to induce ACAID, and that class I-deficient PEC were incapable of inducing either BSA-specific ACAID or splenic regulatory T cells that suppress BSA-specific delayed hypersensitivity. We conclude that cells that carry an ACAID-inducing signal to the spleen are: 1) restricted in their ability to induce ACAID by MHC-encoded molecules, 2) these cells are the proximate APC ACAID, and 3) class I MHC molecules play a central role in presenting exogenous protein Ag to splenic T cells in ACAID.

Animals↗
PubMed1993

Bactericidal catechins damage the lipid bilayer.

The mode of antibacterial action of, the green tea (Camellia sinensis) extracts, (-)-epigallocatechin gallate (EGCg) and (-)-epicatechin (EC) was investigated. Strong bactericidal EGCg caused leakage of 5,6-carboxyfluorescein from phosphatidylcholine liposomes (PC), but EC with very weak bactericidal activity caused little damage to the membrane. Phosphatidylserine and dicetyl phosphate partially protected the membrane from EGCg-mediated damage when reconstituted into the liposome membrane with PC. EGCg, but not EC, caused strong aggregation and NPN-fluorescence quenching of PC-liposomes and these actions were markedly lowered in the presence of negatively charged lipids. These results show that bactericidal catechins primarily act on and damage bacterial membranes. The observation that Gram-negative bacteria are more resistant to bactericidal catechins than Gram-positive bacteria can be explained to some extent by the presence of negatively charged lipopolysaccharide.

Anti-Bacterial Agents↗