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Biomedical subjects

Y Okuda

Publications and source records attributed to Y Okuda.

At least 325 records · Page 18Linked to original sources
PubMed1990

[Primary liver cancer coincident with schistosomiasis japonica].

The etiologic relationship of a parasitic liver disease to primary liver cancer has long been debated, and reported is a case that has been encountered of a primary liver cancer coincident with Schistosomiasis japonica. A fifty-nine year-old-man was diagnosed as having a primary liver cancer complicated with liver cirrhosis. A posterior segmentectomy was performed and a microscopic examination revealed a primary liver cancer with multiple ovae of Schistosoma japonicum in the fibrous stroma of the portal spaces. Discussed is the etiologic relationship of Schistosomiasis japonica to the primary liver cancer.

Carcinoma, Hepatocellular↗
PubMed1990

[A double cancer of the gallbladder and common bile duct associated with an anomalous arrangement of the choledocho-pancreatic ductal junction--a case report and a review of the literature].

Reported is the case of a 65-year-old woman who complained of general fatigue and itching. The cancer of the gallbladder and the common bile duct associated with anomalous arrangement of choledocho-pancreatic ductal junction was diagnosed after examination by ERCP, PTCS, US, and CT. The cancer of the common bile duct had metastasized to the pancreas, the portal vein, and the regional lymph nodes and was unresectable. It is well known that an anomalous arrangement of the choledocho-pancreatic ductal junction is highly associated with a cancer of the common bile duct or the gallbladder. But a case that is associated with double cancers is rare and only 6 cases have been reported in the Japanese literature. In addition to a discussion of this case, the literature is reviewed.

Aged↗
PubMed1990

[Clinical study of extracorporeal shock wave lithotripsy for 1000 patients with renal and ureteral stones].

Using a Dornier HM3 lithotripter, we treated 1,000 patients with renal and ureteral stones from April, 1986 to July, 1989. They consisted of 612 solitary stones (pelvic stones, 152; calyceal stones, 167; ureteral stones, 293), 265 multiple stones and 123 staghorn calculi (complete, 48; partial, 75). The overall rate of the auxiliary procedure was 59.3% (pre-operative, 47.9%; post-operative, 11.4%). Pre-operative procedure included 430 catheterizations, 26 percutaneous nephrostomies (PNSs) and 23 pyelograms . Post-operative procedure included 69 transurethral lithotripsy , 21 PNSs, 26 percutaneous nephrolithotripsy (PNLs), 6 meatotomy , 5 chemolysis and 1 open surgery. 484 (68.3%) in 709 good follow-up cases were stone-free at the time of 3 months since the first extracorporeal shock-wave lithotripsy (ESWL). Complications were pain (34.8%), fever (4.3%), pain & fever (8.5%), subcapsular hematoma (0.1%) and ureteral obstruction (0.1%). Thus, ESWL is considered to be a useful means for renal and ureteral stones and in the case of large stone the combination therapy with PNL is more effective than ESWL-monotherapy.

Adult↗
PubMed1990

[Assessment of the biological activity of residual or recurrent neuroblastoma tumors with 131I-metaiodobenzylguanidine (MIBG) scintigraphy].

131I-Metaiodobenzylguanidine (MIBG) is now accepted as a useful agent for the diagnosis of adrenal medullary tumor. The aim of this paper is to evaluate 131I-MIBG for the assessment of the biological activity of residual or recurrent tumor after initial treatment in patients with neuroblastoma. Nineteen scans were performed for 9 patients, mean age 3.5 years-old. Computed tomography demonstrated paravertebral mass in six and metastatic liver tumor in four cases. Anterior and posterior images of the thorax and abdomen were taken 48-72 hours after injection of 7.4-18.5 MBq (0.2-0.5 mCi) 131I-MIBG. Positive images were obtained in 8 scans for four patients and followed by rapid growth of tumor and increased urinary dopamine. The biological activity of residual or recurrent tumor was thought to be high in these patients. Eleven scans for 5 patients revealed negative. In four of them, the tumor size reduced and urinary dopamine value remained within normal limits on the follow-up study. The tumor was assumed to have low biological activity in these patients. One case in which initial scan was negative became positive on the follow-up study. 131I-MIBG activity did not well correlate with urinary vanillylmandelic acid as compared with urinary dopamine. In conclusion, 131I-MIBG proved to be useful for assessing biological activity of residual or recurrent tumor of neuroblastoma and estimating the prognosis of the patient.

3-Iodobenzylguanidine↗
PubMed1989

Effect of 3'-azido-3'-deoxythymidine on replication of duck hepatitis B virus in vivo and in vitro.

3'-Azido-3'-deoxythymidine (AZT) inhibits the replication of the human immunodeficiency virus (HIV) by blocking the formation of the phosphodiester bond and has been used clinically for the treatment of HIV infection. To assess the effect of AZT on the replication of hepadnaviruses, which replicate through reverse transcription, both the liver tissue and primary cultured hepatocytes from ducklings previously infected with duck hepatitis B virus (DHBV) were examined for DHBV DNA before and after the treatment with AZT. We did not observe suppression of DHBV replication at any doses in our system as measured by viral DNA synthesis in infected duck hepatocytes. The data strongly suggest that AZT has no inhibitory effect on DHBV reverse transcriptase.

Animals↗
PubMed1989

Enterically transmitted non-A, non-B hepatitis in cynomolgus monkeys: morphology and probable mechanism of hepatocellular necrosis.

Two cynomolgus monkeys were inoculated with a stool extract originally derived from patients suffering from enterically transmitted non-A, non-B hepatitis. Subsequently, the primates developed self-limiting acute hepatitis and their liver tissues were obtained sequentially by needle biopsy or at sacrifice. Histologically, the liver tissues exhibited necroinflammation which appeared in parallel, both in time and magnitude, with elevation in serum aminotransferases. Necroinflammation was characterized by focal dropout of hepatocytes with accumulation of lymphocytes and macrophages. These lymphocytes were positive for a cytotoxic/suppressor immunophenotype. The hepatocytes surrounding these focal necroses showed depletion of glycogen granules and decrease in glucose-6-phosphatase and succinic dehydrogenase activities. Ultrastructurally, damaged hepatocytes around the focal necroses revealed marked dilatation of both rough and smooth endoplasmic reticula, swelling and disruption of the mitochondria and leakage of nuclear materials into the cytoplasm. Frequently, direct contact between the damaged hepatocytes and lymphocytes was noted. Virus-like particles measuring about 27 nm in diameter were observed singly or in small groups within the cytoplasm of damaged hepatocytes. Primary hepatocyte culture of a cynomolgus monkey, inoculated with a transmissible stool extract did not show any cytopathic change, although similar virus-like particles were recognized ultrastructurally in the cultured hepatocytes. Morphological analysis of in vitro and in vivo transmission studies in cynomolgus monkeys strongly supported the hypothesis of immune-mediated hepatocytolysis rather than a direct cytopathic effect of this hepatitis virus.

Animals↗
PubMed1989

In vitro stability of insulin-loaded erythrocytes after freezing storage.

In order to clarify the utility of resealed erythrocytes as a cell carrier of insulin the freezing stabilities of loaded cells encapsulating two different amounts of insulin (about 0.1 and 7.0 IU/ml of packed cells) were investigated in an anti-freezing reagent containing a high concentration of glycerol at -80 degrees C. After storing for 1 week under the above condition the preparation was thawed at 37 degrees C. Although the osmotic resistance of the loaded cells was lowered more than that of intact cells, the freezing and thawing treatment did not change the resistance of the loaded cells to osmotic shock. Recoveries of hemoglobin from loaded cells with a low insulin content (0.1 IU/ml of cells) and the cell volume after freezing and thawing were similar to those from intact cells and the cells resealed without insulin. However, the recovery of insulin from the cells with a high insulin content (7.0 IU/ml of cells) was the same as that from one with a low insulin content (about 16%). In the in vitro stability experiment at 37 degrees C the insulin content in the loaded cells decreased according to a biexponential function. The considerable fraction of the loaded cells were lysed by freezing and thawing. In the in vitro stability experiment the decline curve of insulin in the cells showed apparently monoexponential kinetics. From these results, it was established that insulin-loaded erythrocytes may be stored in a high concentration of glycerol under freezing at -80 degrees C, although a partial decrease in the stability of cells was observed after thawing.

Animals↗
PubMed1989

Effects of 3-hydroxybutyrate and hyperosmolarity on glucagon release from isolated perfused canine pancreas.

The effects of 3-hydroxybutyrate (3-OHB) and hyperosmolarity on glucagon secretion were examined in the isolated perfused canine pancreas. When 3-OHB was infused for 15 min into the pancreas perfused with 2.8 mM glucose, 5 and 20 mM sodium 3-OHB inhibited it after a transient stimulation, whereas a similar transient stimulation was observed also by the infusion of 20 mM NaCl in a control experiment. The above inhibition was not observed under the perfusate condition of 5.5 mM glucose plus 10 mM arginine. When the isolated canine pancreas was perfused under the perfusate condition of acidosis (pH 7.1), ketoacidosis (pH 7.1 and 20 mM 3-OHB) or hyperosmolarity (+60 mOsm/kg with sucrose) throughout the experiment, the glucagon concentrations produced by 2.8 mM glucose under the ketoacidotic and hyperosmolar conditions, were less than half of those obtained under the standard condition. The insulin level was not influenced by the above perfusate conditions. These results suggest that 3-OHB inhibits glucagon secretion stimulated by glucopenia, but does not inhibit it stimulated by amino acids, and that hyperosmolarity inhibits glucagon secretion but does not inhibit insulin secretion. The pathophysiological significance of these results must be slight, considering the presence of hyperglucagonemia during prolonged starvation or diabetic ketoacidosis.

3-Hydroxybutyric Acid↗
PubMed1989

[Fixation effect of phospholipids using tannic acid. Part 1: Artificial lung surfactant].

In order to study the preservation of phospholipids in specimens for electron microscopic study, two procedures were compared; routine double fixation with glutaraldehyde followed-by osmium tetroxide and fixation with a mixture of tannic acid-glutaraldehyde followed by osmium tetroxide, utilizing both glass slide smear and ultrathin section methods, using artificial lung surfactant (mainly composing of phospholipids). The following results were obtained. (1) In routine double fixation with glutaraldehyde-osmium tetroxide, although the lamellar structure, mainly composed of phospholipids, was often visualized, prefixation with mixed tannic acid-glutaraldehyde always resulted in a lamellar structure with a regular periodicity and good contrast. (2) The saturated phospholipid was better preserved with acetone dehydration than with alcohol dehydration. (3) Depending on the outcome of the first fixation, there was extensive loss of phospholipids during the process due to alcohol dehydration and propylene infiltration. (4) When the specimens were fixed with osmium tetroxide prior to tannic acid treatment, the multilamellar structure of the bilayer was usually irregular. Moreover, if the specimens were fixed with osmium tetroxide without tannic acid, phospholipid preservation was not good. From the above results, it became, apparent that prefixation by a mixture of tannic acid-glutaraldehyde followed by osmium tetroxide postfixation and dehydration by acetone was the most appropriate method for preserving saturated phospholipids and thus a stable ultrastructure of phospholipids an lamellar will obtained.

Fixatives↗
PubMed1989

[Chest X-ray findings in infantile Chlamydia trachomatis pneumonia; report of two cases].

Chest X-ray findings in two infants with Chlamydia trachomatis pneumonia were reported. Both cases showed bilateral interstitial infiltrates and hyperinflation. These findings are not specific to this pneumonia. Chlamydia trachomatis pneumonia should be considered as one possibility when we find such findings on chest X-ray in infants.

Antibodies, Bacterial↗
PubMed1989

[The effect of the protease inhibitor FUT-175 on phospholipase A2, complement, prostaglandins and prekallikrein during endotoxin shock].

This experiment was performed to investigate the effect of protease inhibitor FUT on the blood pressure, phospholipase A2, complement 3, CH50, thromboxane B2, 6-keto-PGF1 alpha and prekallikrein during endotoxin shock using 19 dogs. LPS was injected at a dose of 3mg.kg-1 in 11 dogs. Eight dogs were injected with FUT of 2mg.kg-1 before administration of LPS, and then infused continuously with 50 micrograms.kg-1.min-1 of FUT. FUT suppressed a decrease in the blood pressure, activations of phospholipase A2 and prekallikrein, but had no effect on serum TXB2, 6-keto-PGF1 alpha, C3 and CH50 compared with the LPS alone group. Suppression of the activation in phospholipase A2 and the falling of the blood pressure suggests that FUT has indirect effects such as inhibition of prekallikrein system.

Animals↗
PubMed1989

[Cell kinetic analysis of human brain tumors by bivariate flow cytometric measurement of cellular DNA content and amount of incorporated bromodeoxyuridine].

Cell kinetics of 91 human brain tumors obtained from 88 patients were analyzed with the following two methods, 1) bivariate (two-color) flow cytometric measurement of cellular DNA content and amount of bromodeoxyuridine (BrdU) incorporated into cellular DNA, in 66 specimens, 2) immunohistochemical detection of BrdU incorporated S-phase cells, in 34 specimens. Patients were given an intravenous 1 hour infusion of 200 mg/sq. m. of BrdU 1-2 hours before the surgical removal. The excised tumor specimen was divided into several portions. One was fixed with 70% ethanol and embedded in paraffin, and another was digested mechanically and/or chemically to obtain a single cell suspension, and fixed in 70% ethanol. Paraffin-embedded tissue sections were stained by the peroxidase-antiperoxidase immunohistochemical method using anti-BrdU monoclonal antibody (MoAb). Single cell suspensions were reacted with fluorescein isothiocyanate (FITC) conjugated anti-BrdU MoAb, or anti-BrdU MoAb and FITC-conjugated second antibody successively by the staining with propidium iodide, for flow cytometry (FCM). Rates of S-phase fraction in single cell suspensions calculated by bivariate FCM were correlated well with labeling indexes (LI, i.e. the percentage of BrdU incorporated cells) calculated in tissue sections, but not with the result of analysis of DNA histogram by Dean's method. This discrepancy is probably due to large coefficient value in several samples. Histological malignancy of the tumors was reflected both in the proliferating index (PI, i.e. % S+G2M phase) calculated by bivariate FCM and the LI by immunohistochemical method. PI tended to be high in primitive neuroectodermal tumors and metastatic carcinomas, moderately high in gliomas, and low in benign tumor groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1988

Metabolic activation of environmental carcinogens and mutagens by human liver microsomes. Role of cytochrome P-450 homologous to a 3-methylcholanthrene-inducible isozyme in rat liver.

The metabolic activation of procarcinogens and promutagens by human liver microsomal cytochrome P-450 has been investigated by means of a newly developed method measuring the induction of umu gene in Salmonella typhimurium TA1535/pSK1002 [T. Shimada and S. Nakamura, Biochem. Pharmac. 36, 1979 (1987)]. The chemicals examined were aflatoxin B1 (AFB1), eight carcinogenic heterocyclic aromatic amines isolated from protein and amino acid pyrolysates, and 2-aminoanthracene. Liver microsomes from six patients catalyzed the metabolic activation of these chemicals; 2-amino-3,5-dimethylimidazo[4,5-f]quinoline (MeIQ) and AFB1 were most actively bioactivated, followed by 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-aminoanthracene (2-AA) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline. At least two forms of human cytochrome P-450 may be involved in the activation of these procarcinogens. This suggestion was supported by the following lines of evidence: (a) addition of non-ionic detergent Emulgen 913 to the incubation mixture caused a more profound inhibition of microsome-catalyzed activation of AFB1 than of MeIQ, IQ and 2AA, (b) 7,8-benzoflavone stimulated the activation of AFB1 by about 2.5-fold, whereas it inhibited significantly the reactions with MeIQ, IQ and 2AA, and (c) polyclonal antibodies against a 3-methylcholanthrene-inducible form of rat cytochrome P-450 (P-450d) caused a marked inhibition of the metabolic activation of MeIQ, IQ and 2-AA by human liver microsomes though they did not show any effects on the microsomal activation of AFB1. Data are also presented showing that none of the reactions catalyzed by human liver microsomes were inhibited by antibodies to a phenobarbital-inducible form of rat cytochrome P-450 (P-450b). These results suggest that the human cytochrome P-450 isozyme that is immunochemically similar and, thus, homologous to rat P-450d plays a major role in the metabolic activation of several procarcinogens examined, and that the activation of AFB1 is catalyzed by another and, possibly, not phenobarbital-inducible form(s) of human cytochrome P-450.

Adult↗
PubMed1988

Pineoblastoma with neuronal differentiation--immunohistochemical and immunocytochemical studies.

Immunohistochemical and immunocytochemical studies were performed on a specimen obtained at operation from a 4 year-old female with intracranially spread pineal tumor in the right temporal lobe. Microscopically, it was a highly cellular tumor, and the cells contained chromatin-rich round or oval nuclei and scanty cytoplasms. There were numerous mitotic figures. Rosettes were not detected. Both immunohistochemical staining of paraffin-embedded sections and immunocytochemical staining of short-term cultured cells disclosed a subgroups of cell positive for NSE and 68K-NF (neurofilament). No cells were positive for GFAP, S-100 protein or HCG. From these findings, the tumor was thought to be pineoblastoma, which is an undifferentiated tumor that rarely shows divergent differentiating potential. This is the first report of pineoblastoma with the differentiation only toward the neuronal line confirmed by the analysis of immunohistochemistry and immunocytochemistry.

Brain Neoplasms↗