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Biomedical subjects

T Harada

Publications and source records attributed to T Harada.

At least 487 records · Page 27Linked to original sources
PubMed1994

The induction of specific antitumor immunity by in vivo treatment with interleukin-1 and sonicated tumor extract in a murine model.

BALB/c mice were pretreated intraperitoneally with interleukin-1 (IL-1) and sonicated tumor extract (SE) from plasmacytoma MOPC104E, 10, 7, and 4 days prior to the intraperitoneal or subcutaneous inoculation of MOPC104E cells, following which significant suppression was observed. The mean survival time and tumor diameter on day 21 were 46.7 days and 0 mm, respectively, in contrast to the 20.9 days and 20.4 mm of control mice. Mice pretreated with IL-1 and SE from MOPC104E (MOPC-SE) were not suppressed following fibrosarcoma MethA inoculation, which indicates the tumor specificity of immunity in this model. This systemically operating antitumor immunity was also achieved by the intramuscular administration of IL-1, or when tumor challenge was performed on day 7 or 14. Moreover, MOPC104E-specific delayed-type hypersensitivity was detected in these mice. The results of this study suggest the possibilities of a new type of active specific immunotherapy, which could prove useful as postsurgical adjuvant therapy for cancer patients.

Animals↗
PubMed1994

Role of iron and glutathione redox cycle in acetaminophen-induced cytotoxicity to cultured rat hepatocytes.

The aims of this study were to investigate the roles of iron as a catalyst in reactive oxygen metabolite-mediated cellular injury and of the endogenous antioxidant defenses against acetaminophen-induced cytotoxicity in cultured rat hepatocytes. Hepatocytes were isolated and cultured from either 3-methylcholanthrene-treated or untreated rats. Cytotoxicity was evaluated by measuring 51Cr and lactate dehydrogenase release. Acetaminophen caused dose-dependent cytotoxicity in 3-methylcholanthrene-treated, but not untreated, cells. There was a good correlation between 51Cr and lactate dehydrogenase release values. Pretreatment with both diethyl maleate, which covalently binds glutathione as catalyzed by glutathione-S-transferase, and bis(chloroethyl)-nitrosourea, an inhibitor of glutathione reductase, enhanced acetaminophen-induced cytotoxicity. Inhibition of endogenous catalase activity by pretreatment with aminotriazole did not affect acetaminophen-induced cellular damage. Addition of exogenous catalase failed to protect against acetaminophen-induced cytotoxicity. Preincubation with both deferoxamine, a ferric iron chelator, and phenanthroline, a ferrous iron chelator, diminished acetaminophen-induced cytotoxicity. These results indicate that iron is crucial in mediating acetaminophen-induced cytotoxicity and that the glutathione redox cycle, but not catalase, plays a critical role in the endogenous defenses against acetaminophen-induced cellular damage in cultured rat hepatocytes in vitro.

Acetaminophen↗
PubMed1994

Bile flow in a mutant Sprague-Dawley rat with defective biliary excretion of glutathione.

The Eisai hyperbilirubinemic rat is a mutant strain of Sprague-Dawley origin with hereditary defects in the biliary excretion of bilirubin glucuronide, glutathione, and several other organic anions. The correlation between bile flow and bile acid excretion rates during taurocholate infusion revealed that bile acid-independent flow was smaller in the mutant than in intact Sprague-Dawley rats (19.3 vs 56.0 microliters/kg per min), while bile acid-dependent flow was similar. The correlation between bile flow and glutathione excretion rates in Sprague-Dawley rats with modified hepatic glutathione levels revealed that a certain portion of bile flow was proportional to the biliary excretion of glutathione, with a coefficient of 551 bile per 1 mol glutathione. One-third of bile acid-independent bile flow in intact Sprague-Dawley rats was accounted for by glutathione osmosis, which feature was absent in the mutant rats.

Animals↗
PubMed1994

Protection of cultured rat gastric cells against oxidant-induced damage by exogenous glutathione.

BACKGROUND/AIMS: Reduced glutathione (GSH) is an intracellular protectant against oxidants. The present study determined whether extracellular GSH protects against oxidant damage or whether an uptake system of GSH is present in cultured gastric cells. METHODS: Hydrogen peroxide was generated by glucose oxidase and glucose. Cytotoxicity was assessed by 51Cr release. Intracellular GSH was assayed by the method of Tietze. RESULTS: Pretreatment with extracellular GSH decreased H2O2-induced 51Cr release. Treatment with GSH enhanced cellular GSH content. Protection by pretreatment with GSH was prevented by buthionine sulfoximine (an inhibitor of gamma-glutamylcysteine synthetase). Enhancement of intracellular GSH was also prevented by buthionine sulfoximine. Acivicin (an inhibitor of gamma-glutamyl transpeptidase) prevented intracellular accumulation of GSH from extracellular GSH. Cysteine was effective in preventing damage and enhancing intracellular GSH content, whereas both glutamine and glycine were not. CONCLUSIONS: Extracellular GSH protects cultured gastric cells from H2O2 damage by accelerating intracellular GSH synthesis; this is mediated by membrane-bound gamma-glutamyl transpeptidase acting on extracellular GSH (which supplies these cells with cysteine) and then by intracellular gamma-glutamylcysteine synthetase.

Animals↗
PubMed1994

Two-dimensional demonstration of myenteric nerve plexus: application for pseudo-Hirschsprung's disease.

The use of two-dimensional demonstration of myenteric nerve plexus for the morphological estimation of pseudo-Hirschsprung's disease is introduced. By fluorescent immunohistochemistry for S-100 protein on flat-mounted frozen sections, a decrease in the amount of ganglionic plexuses in the small intestinal segments in cases of pseudo-Hirschsprung's disease was able to be distinguished from normoganglionic plexuses in control cases. Moreover, a morphological difference between the two types of cases was clearly demonstrated. This method may be an indispensable tool in the reliable diagnosis of pseudo-Hirschsprung's disease.

Female↗
PubMed1994

Effects of capsaicin analogs on adrenal catecholamine secretion in rats.

To assess the relationship among the structure, pungency and thermogenic action, a series of capsaicin analogs with saturated acyl moieties (heptanoyl to eicosanoyl vanillylamide) were synthesized. Pungency of the compounds and the thermogenic action, which was examined by the potential of the compounds (655 nmol/kg, i.v.) to enhance adrenal catecholamine secretion for 15 min in anesthetized rats, were compared. On the chain length of the acyl moieties of the analogs, nonanoyl to octadecanoyl vanillylamide caused strong adrenal catecholamine secretion, but heptanoyl vanillylamide and eicosanoyl vanillylamide caused weak or no response. Pungent analogs except heptanoyl vanillylamide and non-pungent analogs except eicosanoyl vanillylamide had strong potency to secrete adrenal catecholamine.

Adrenal Medulla↗
PubMed1994

Conformation of (2-->1)-beta-D-fructan in aqueous solution.

The conformation and dilute solution properties of (2-->1)-beta-D-fructan in aqueous solution were studied by gel permeation chromatography, low-angle laser light-scattering photometry, viscometry, small-angle X-ray scattering and electron microscopy. Fractions covering a broad range of weight-average molecular weights (Mw) from 1.49 x 10(4) to 5.29 x 10(6) were obtained from a native sample by ultrasonic degradation and fractional precipitation. For Mw < 4 x 10(4), the intrinsic viscosity [eta] varies with Mw0.71, indicating that the fructan chain behaves as a random coil expanded by an excluded-volume effect in this molecular weight region. For Mw > 10(5), [eta] exhibits an unusually weak dependence on Mw and finally becomes almost independent of molecular weight. This behaviour is interpreted in terms of a globular conformation of the high-molecular-weight fructan molecules. Small-angle X-ray-scattering measurements and electron microscopic observations support this interpretation of the values of [eta] observed.

Aspergillus↗
PubMed1994

Glomerular expression of type III and type IV collagens in benign nephrosclerosis: immunohistochemical and in situ hybridization study.

The development of glomerular sclerosis in benign nephrosclerosis (BNS) was studied. We investigated the intraglomerular expression of type III and IV collagens and their mRNAs by immunohistochemistry and by the in situ hybridization method. Formalin-fixed paraffin sections from 28 patients with BNS and 10 control cases were stained by the avidin-biotin complex (ABC) method using monoclonal antibodies for human type III and IV collagens. In the course of the sclerotic process of the glomerulus in BNS, the glomerular staining intensity of type IV collagen increased. The strongest staining was observed in the glomerulus at the early sclerotic stage, and intensity decreased slightly at the later stages. Although type III collagen was absent in normal and nonsclerotic glomeruli, peripheral regions of the sclerotic glomeruli were positive at the early sclerotic stage. Later, type III collagen was diffusely observed in the completely hyalinized glomeruli. The expression of type III and type IV collagen mRNAs was detected in the glomeruli of BNS by the non-radioactive in situ hybridization method using thymine-thymine (T-T) dimerized synthetic oligonucleotides. The number of mRNA positive cells for type III and type IV collagens increased at the presclerotic and early sclerotic stages. But these cells gradually decreased in number as glomerular sclerosis developed. We concluded that type III collagen was presumably synthesized by the intraglomerular cells and may contribute to the development of glomerular sclerosis in BNS along with type IV collagen.

Adult↗
PubMed1994

Microarterial anastomosis with a distal tapering technique.

In microsurgical arterial anastomoses, there are some occasions in which the diameter of the distal artery is much larger than that of the proximal one. A fish-mouth incision technique is useful when there is considerable size discrepancy. However, this method cannot be used when the distal artery is much larger than the proximal artery because turbulent flow and thrombus formation occur, due to the sudden increase of luminal diameter. The distal tapering technique is recommended to prevent turbulent flow. A wedge resection is performed in the distal surplus vessel wall, and there is no sudden change in luminal diameter. Two clinical cases are presented in which this technique was used effectively.

Adult↗
PubMed1994

Application of neutral red staining for evaluation of the viability of dermatophytes and Candida in human skin scales.

The fungal elements observed by direct microscopic examination sometimes fail to grow on subsequent culture. To elucidate the cause of this discrepancy, the viability of dermatophytes and Candida in skin scales was evaluated by neutral red staining. Autoradiographic study using 3H-thymidine confirmed that grain-positive cells (viable cells) were stained with neutral red, whereas negative cells (non-viable cells) were not stained. Taking this as a baseline, the correlation between neutral red-positive fungal elements in scales taken from 211 patients with tinea and 27 patients with cutaneous candidosis and cultures on Sabouraud glucose agar was studied. Strong positive correlations were found in both mycoses. These findings suggest that neutral red staining provides a useful method for evaluating the viability of dermatophytes and Candida in human skin scales.

Arthrodermataceae↗
PubMed1994

Endometrial carcinogenesis induced by concurrent oral administration of ethylenethiourea and sodium nitrite in mice.

Endometrial carcinogenesis induced by concurrent oral administration of ethylenethiourea (ETU) and sodium nitrite (NaNO2) was investigated in ICR (Crj:CD-1) female mice. A mixed solution of ETU (100 mg/kg) and NaNO2 (70 mg/kg) was given to animals orally once a week for up to 6 months and all surviving animals were killed at 12 months of study. During the study, estrous cycle was monitored by vaginal smear and five or 10 selected animals were subjected to interim killing at 3 month interval to observe time-related carcinogenic responses of the uterus. Treatment with ETU and NaNO2 resulted in development of endometrial adenocarcinomas in the uterine horn and the incidence reached 42% in the surviving animals at 12 months. Prior to the development of the tumor, atypical hyperplasia of endometrial glands was frequently observed and regarded as the precancerous lesion. Immunohistochemistry for bromodeoxyuridine (BrdU) incorporation revealed higher labeling indices in both hyperplastic and neoplastic endometrial glandular cells, and the index in the adenocarcinoma was more than 20% on average at any stage of the estrous cycle. Overexpression of p53 protein, which is frequently demonstrated in virulent phenotypes of human corpus cancers, was seen in three out of eight (38%) adenocarcinomas, but not in the atypical hyperplasia or normal endometrial glands. There were no treatment-related changes in the estrous cycle on vaginal smears at any interval of the study. The analyses for plasma ovarian hormones at 12 months disclosed a marked depression of progesterone in the treated animals, while the 17 beta-estradiol (E2) level was comparable to the controls. These results suggest that endometrial carcinogenesis by ETU and NaNO2 could be initiated with atypical hyperplasia of the endometrial gland and a decrease in plasma progesterone level may play an important role in the development of endometrial carcinogenesis. In addition, inactivation of the p53 gene may play a significant role in the malignant transformation of endometrial epithelial cells in mice.

Adenocarcinoma↗
PubMed1994

Assessment of functional integrity of frozen-thawed mouse embryos by albumin and leucine uptake.

To assess the effects of freezing-thawing on metabolic functions of embryos prior to implantation, we measured the uptake of [125I]bovine serum albumin (BSA) and [3H]leucine in 2-cell mouse embryos, that were freshly collected (control), exposed to cryoprotectants (non-frozen), and frozen-thawed, and in morulae and blastocysts cultured from these 2-cell embryos. No significant difference in [125I]BSA uptake by 2-cell embryos was observed among the three groups. However, [125I]BSA uptake by blastocysts in the frozen-thawed group was significantly reduced compared with the control and non-frozen groups. [3H]leucine uptake by 2-cell embryos in the frozen-thawed and non-frozen groups was significantly less than in the control group. Fluorescein diacetate staining was performed in the control and frozen-thawed 2-cell embryos. The intensity of fluorescence after fluorescein diacetate exposure did not differ between the control and frozen-thawed embryos. The present study with mouse embryos suggests that freezing-thawing procedures impair the metabolic functions, in particular the membrane transport system, of embryos. Measurements of BSA and leucine uptake in embryos may be useful for evaluating the quality of frozen-thawed embryos.

Animals↗
PubMed1994

Laparoscopic unwinding of adnexal torsion caused by ovarian hyperstimulation.

A case of laparoscopic unwinding of a twisted enlarged ovary and Fallopian tube caused by ovarian hyperstimulation is presented. The laparoscopic unwinding was simple and was carried out in a short time. The patient's post-operative course was uneventful. Complications such as thromboembolism were not observed and the post-operative ovarian function was well preserved after such procedures. Preservation of the ovary is highly important in young infertile women. Prompt diagnosis with an immediate unwinding of the twisted adnexa by a laparoscopic technique can produce a valuable outcome.

Adnexal Diseases↗
PubMed1994

Penile verrucous carcinoma with anaplastic transformation following radiotherapy. A case report with human papillomavirus typing and flow cytometric DNA studies.

We report a case of penile verrucous carcinoma with anaplastic transformation after radiotherapy. A 49-year-old man with penile verrucous carcinoma initially underwent excision and chemotherapy followed by radiotherapy when the carcinoma recurred locally. Twenty-four months after the completion of radiotherapy, the verrucous cancer transformed to an anaplastic spindle-cell carcinoma, which resulted in his death 10 months after diagnosis. Autopsy confirmed a huge hemorrhagic recurrent lesion and lung metastases. In situ hybridization with biotinylated DNA probes did not detect any type of human papillomavirus (HPV) (types 6/11, 16/18, and 31/33/51) in either the primary or the anaplastic tumor. Immunohistochemical HPV capsid antigens were also negative in both lesions. A flow cytometric analysis, using paraffin-embedded materials, showed a diploid DNA content in the excised verrucous carcinoma and an aneuploid content in the anaplastic tumor. This patient most likely had radiation-induced transformation of an anaplastic carcinoma. Wide excision and, if necessary, amputation, are preferred to radiotherapy.

Carcinoma↗
PubMed1994

Purification and properties of a new exo-(1-->3)-beta-D-glucanase from Bacillus circulans YK9 capable of hydrolysing resistant curdlan with formation of only laminari-biose.

A (1-->3)-beta-D-glucan glucanohydrolase (EC 3.2.1.6), capable of hydrolysing resistant curdlan, was purified chromatographically from the culture supernatant of Bacillus circulans complex YK9 on Toyopearl HW-55F and butyl-Toyopearl 650M columns. The purified enzyme had a specific activity of 190 units mg-1 on regenerated curdlan. The molecular mass was estimated to be about 70 kDa as judged by SDS-PAGE. The enzyme had a pH optimum of approximately pH 6.0. It hydrolysed regenerated and resistant curdlans yielding predominantly laminari-biose, although the rate of hydrolysis of the former was much higher than the latter. This enzyme rapidly hydrolysed laminaran, curdlan and carboxymethyl-curdlan, but did not cleave schizophyllan and screloglucan, which have glucosyl side chains. The enzyme hydrolysed low molecular mass (1-->3)-beta-D-glucans-(mean degree of polymerization, DPn = 131, 49 and 14) and laminari-heptaose more efficiently than curdlan. It also hydrolysed laminari-hexaose and -pentaose effectively, but laminari-tetraose only slightly and it did not hydrolyse laminari-triose or -biose. The enzyme is an exo-hydrolase of curdlan and various oligomers composed of (1-->3)-beta-D-glucosidic linkages, liberating laminari-biose from their non-reducing terminals. The laminari-biose generated was in the alpha-form.

Bacillus↗
PubMed1994

An autopsy case of acquired immune deficiency syndrome (AIDS) with preceding aplastic anemia.

A case of acquired immunodeficiency syndrome (AIDS) with preceding aplastic anemia is reported. The patient was a 36 year old female who had been diagnosed as having aplastic anemia 10 years before and thereafter had received multiple transfusions. Human immunodeficiency virus (HIV)-seropositivity was revealed 10 months prior to her death, but no particular clinical signs indicating HIV infection, pre-AIDS or onset of AIDS were recognized before serological diagnosis, although the slow progression of leukopenia was noted along with thrombocytopenia. Her general condition deteriorated during the last 10 months accompanied by an acute decrease in the CD4/CD8 ratio. Autopsy revealed full-blown AIDS: systemic aspergillosis, progressive multifocal leukoencephalopathy, Epstein-Barr virus-related B cell lymphoma arising in the diaphragm and severe lymphocyte depletion in the lymph nodes and spleen. Markedly hypoplastic bone marrow was considered to be primarily attributable to the aplastic anemia but the affection of AIDS was not excluded. The possible transmission route of HIV and the effect of the preceding aplastic anemia on the infection and clinical course of AIDS are discussed.

AIDS-Related Opportunistic Infections↗
PubMed1994

Immunoelectron microscopic localization of carcinoembryonic antigen in gastric adenocarcinoma cell lines.

The distribution of carcinoembryonic antigen (CEA) in human gastric adenocarcinoma cell lines (HPE-GAC-3 cells and HPE-GAC-2 cells) was determined immunohistochemically by indirect peroxidase-labeled antibody method at the light and electron microscopic levels. In GAC-3 cells that proliferated as non-adherent single cells, CEA was located in the perinuclear spaces, the endoplasmic reticulum, Golgi apparatus, vesicles, multivesicular body (MVB) and entire plasma membrane. Membrane CEA was shown to be internalized into MVB in GAC-3 cells. In GAC-2 cells that form an acinus, CEA was predominantly present along the microvilli of the luminal surface and in glycocalyceal bodies, the vesicles which bud from the microvilli into the lumen. These results suggest that in poorly differentiated cancer cells CEA is transported over the entire cell surface, retained on the membrane and accumulated into the cell by way of the MVB, but in well differentiated cancer cells the newly synthesized CEA is rapidly and predominantly transported to the luminal surface and rapidly released from the membrane into the lumen by way of the glycocalyceal body.

Adenocarcinoma↗