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Biomedical subjects

T Oishi

Publications and source records attributed to T Oishi.

At least 73 records · Page 4Linked to original sources
PubMed1997

Preparation and Characterization of New Self-Assembled Polyamide Film Containing Disulfide Bonds on Gold Electrode

New polyamides containing disulfide bonds in their main chains are prepared by condensation between 3,3'-dithiodipropionic acid and various alkyldiamines (NH2-(CH2)n-NH2, n = 4 and 12, polyamide I and II). The polyamides form a thin layer on a gold substrate. The surface of polyamide modified electrodes were investigated by AFM and XPS measurements. The surface structure depends on the polyamide structure, especially alkyl chain length of the polyamide. Furthermore, adsorption of ferrocene derivatives [1-ferrocenylmethanol (FME) or 2-amino-3-ferrocenylpropionic acid (AFP)] on the polyamide modified electrodes and their electrochemical responses were investigated. Interaction between the polyamide on the electrode and the ferrocene derivatives depends on the structure of the ferrocene derivatives and polyamide chain length.

Journal Article↗
PubMed1997

Extraovarian sex cord-stromal tumor: case report and review of the literature.

A 45-year-old woman was found at laparotomy to have a multinodular solid tumor within the broad ligament, which was removed by total hysterectomy and bilateral salpingo-oophorectomy. Both ovaries were unremarkable. Three years after the operation, retroperitoneal tumor was detected, which was associated with clinical evidence of estrogen production. Histological examination of the primary and retroperitoneal tumors showed histological features that resembled those of granulosa cell tumors. Previously reported sex cord-stromal tumors arising in extraovarian sites were reviewed with respect to the histogenesis of these tumors.

Cell Nucleus↗
PubMed1997

Alterations of renal V1 and V2 receptors in spontaneously hypertensive rats and DOCA-salt hypertensive rats using computerized quantification for macro-autoradiogram.

We previously examined the precise localization of vasopressin (VP) V1 and V2 receptors in the rat kidney using in vitro macro- and micro-autoradiography (ARG), and established the methodology of quantification for macro-ARG. In this study, to elucidate the role of VP in hypertension, we investigated the change within V1 and V2 receptors in the kidney of spontaneously hypertensive rats (SHR) and deoxycorticosterone acetate (DOCA)-salt hypertensive rats at different hypertensive stages. In SHR, although medullary V1 and V2 receptors decreased compared with age-matched Wistar-Kyoto (WKY) rats at the developmental hypertensive stage, these receptors increased once hypertension was established. Conversely, in DOCA-salt hypertensive rats, both renal V1 and V2 receptors decreased with elevated blood pressure. Therefore, expression of renal V1 and V2 receptors proved to be different between two models of hypertension, SHR and DOCA-salt hypertensive rats, when their blood pressure increases. In DOCA-salt hypertensive rats, renal V1 and V2 receptors may be down-regulated secondary to the high blood VP level. In SHR, the increase in renal V1 and V2 receptors may have a role in the development of high blood pressure in this strain of rats.

Animals↗
PubMed1997

[Serum levels of soluble tumor necrosis factor receptors as markers for disease progression of human immunodeficiency virus infection].

We studied whether the serum levels of soluble tumor necrosis factor receptor(sTNFR) type I or II correlate with clinical progression of human immunodeficiency virus type 1(HIV-1) infection. Serum levels of sTNFR type I and II were measured by an enzyme-linked immunosorbent assay in sixty five patients with HIV-1 infected hemophiliacs and 10 healthy controls. In a longitudinal study, we assessed whether the decline of CD4+ lymphocyte counts were associated with increased serum concentrations of sTNFRs. Elevated serum concentrations of sTNFRs were found among the HIV-1 infected patients and higher in patients with advanced clinical stage. We noticed there were two distinct patient groups in change of CD4+ lymphocyte count when twenty-eight patients were followed retrospectively for a median period of 65 months. 14 patients represented stable CD4+ lymphocyte counts, but another 14 patients had more than 40% decrease of CD4+ lymphocyte counts over the course of this study. Serum sTNFR type II levels were 3.49 +/- 0.71 to 3.11 +/- 0.31 ng/ml in the former group, and 4.88 +/- 0.91 to 4.26 +/- 0.71 ng/ml in the latter group during the study. Significantly higher levels of sTNFR type II were already revealed at early time in the latter group. There was, however, no significant difference in the level of sTNFR type I between the two. These results suggest that serum levels of sTNFR type II provided useful information as a predictor of disease progression related to the decline of CD4+ lymphocyte counts.

Adult↗
PubMed1996

Purification and characterization of nuclear alkaline phospholipase A2 in rat ascites hepatoma cells.

The alkaline phospholipase A2 (PLA2) was purified from nuclei of rat ascites hepatoma cells (AH7974) by column chromatography with a Sephacryl S-300 column and an immunoadsorbent using anti-group II PLA2 monoclonal antibody. From these two columns, the alkaline PLA2 was eluted in parallel with a 17-kDa protein which is reactive to another anti-group II PLA2 polyclonal antibody. Approximately 80% of nuclear PLA2 was inhibited by this antibody. The alkaline PLA2 was found in association with the chromatin fraction among subnuclear fractions. By an immunocytochemical staining, the nuclei of AH7974 were stained more strongly than other parts of cells with anti-group II PLA2 antiserum.

Animals↗
PubMed1996

Effect of renin-angiotensin inhibition on glomerular injuries in DOCA-salt hypertensive rats.

To determine whether growth factors in the glomerulus are induced in the renin suppressed hypertensive model, we examined the mRNA expressions of platelet-derived growth factor (PDGF) B-chain, transforming growth factor (TGF)-beta 1 and angiotensin II type 1 (AT1) receptors in the glomeruli of deoxycorticosterone acetate (DOCA)-salt-treated hypertensive rats (DOCA-treated rats). We also examined the effects of treatment with cilazapril, an angiotensin I-converting enzyme inhibitor (ACEI), and L-158,809, an AT1 receptor antagonist, on these expressions in DOCA-treated rats. We administered oral 10 mg/kg of cilazapril (CILAZA group) and 1 mg/kg of L-158,809 (L158 group) to DOCA-treated rats daily. Systolic blood pressure in the two groups was not decreased compared with that in DOCA-treated rats given saline. The mRNA expressions were examined using reverse transcriptase polymerase chain reaction (RT-PCR) methods. The mRNA expressions of these genes were higher in DOCA-treated rats than in age-matched control rats. After treatment with these agents for 4 weeks, the mRNA expressions of growth factors were suppressed in both the CILAZA and L158 groups. Mesangial expansion and cell proliferation observed in DOCA-treated rats were suppressed in both the CILAZA and L158 groups. Decreases in the size of the glomerulus were observed only in the CILAZA group. These findings suggested that suppression of growth factors and glomerular proliferative changes of these agents are mediated by blocking tissue renin-angiotensin system (RAS) in the renin-suppressed model.

Administration, Oral↗
PubMed1996

Retinal melatonin is not involved in corneal mitotic rhythms in the Japanese quail: effects of formoguanamine hydrochloride and eye-lid suture.

Relation between retinal melatonin and corneal mitotic rhythms in the Japanese quail was investigated in experiments manipulating the ocular physiology by treatments with formoguanamine hydrochloride (FG) and eye-lid suture. In experiment 1, we investigated the effects of FG, which is known to induce photoreceptor degeneration, on retinal melatonin and corneal mitotic rhythms. FG-treatment completely abolished the retinal melatonin rhythms in both LD 12:12 and constant darkness (DD), but the corneal mitotic rhythm was maintained with high mitotic rate in darkness under a LD cycle and subjective night under DD. The result suggests that 1) the photoreceptor cells in the retina are the site for melatonin production and/or for the oscillator which drives the circadian rhythm in retinal melatonin, and 2) melatonin is not involved in generation of the corneal mitotic rhythm. In experiment 2, we investigated the effects of eye-lid suture, which is known to induce eye enlargement and bulgy cornea, on the retinal melatonin and corneal mitotic rhythms. Eye-lid suture abolished the corneal mitotic rhythm in both LD and DD, with a high mitotic rate being maintained throughout 24 hr. But retinal melatonin maintained its rhythm with high levels in darkness under a LD cycle and in subjective night under DD. The result suggests that 1) bulgy cornea in the sutured eye was induced by the increase in mitotic rate in the light period, and 2) disappearance of the corneal mitotic rhythm does not have a relation to retinal melatonin. These results suggest that retinal melatonin is not involved in generation of the corneal mitotic rhythm and that there are two circadian clock systems in the eye.

Animals↗
PubMed1996

Normotensive bilateral pheochromocytoma with Lindau disease: case report.

A 46-year-old man was found to have numerous cerebellar hemangioblastomas on magnetic resonance imaging (MRI). He denied any symptoms and had no history of hypertension, but his family history was remarkable for a father who died of renal cell carcinoma. Computed tomography (CT) of the abdomen revealed bilateral adrenal pheochromocytomas with significant enhancement in the regions where 131I-metaiodobenzylguanidine (MIBG) had noticeably accumulated. Endocrinological examinations demonstrated high plasma and urine catecholamine concentrations which were very responsive to metoclopramide and glucagon loading tests, without a significant change in blood pressure. After resection of bilateral pheochromocytomas, he underwent an operation for the cerebellar tumors. Since pheochromocytomas associated with Lindau or von Hippel-Lindau (VHL) disease have a tendency to multiple occurrence in normotensive patients, we suggest that patients with a family history involving VHL lesions should undergo cranial MRI, abdominal CT, MIBG scintigraphy and endocrinological examinations.

3-Iodobenzylguanidine↗
PubMed1996

T-cell lymphoma presenting with pericardial and pleural effusion as the initial and primary lesion: cytogenetic and molecular evidence.

A 90-year-old woman was admitted with progressive dyspnea. Chest roentgenogram and computed tomography revealed a massive pericardial effusion and bilateral pleural effusion, but no lymphomatous lesion was seen. A diagnosis of malignant lymphoma was made by cytological and immunological studies of the cells obtained from the pericardial effusion. Chromosome analysis showed a clonal abnormality and T-lineage clonality was determined by the rearrangement of the T-cell receptor gamma gene. The patient achieved remission with chemotherapy, but she later relapsed, with right pleural effusion, and died. She exhibited no lymphomatous features throughout the clinical course, indicating the possibility of malignant lymphoma originating from the pericardium and/or pleura.

Aged↗
PubMed1996

[Diagnosis of pulmonary aspergillosis in cases with cavity as sequela of tuberculosis].

Non-invasive pulmonary aspergillosis is frequently seen in cases with cavity as sequela of tuberculosis. Diagnosis of non-invasive pulmonary aspergillosis is not easy except for cases whose chest X-ray findings show a typical fungus ball. How to diagnose pulmonary aspergillosis was studied in 21 patients who showed changes in the radiological findings of cavity as sequela of tuberculosis. We made sputum culture of Aspergillus, measurement of precipitin antibody titer to Aspergillus fumigatus and measurement of PASTOREX ASPERGILLUS in serum and sputum on the 21 patients (group A). PASTOREX ASPERGILLUS in sputum was evaluated in three grades: 1+ approximately 3+. We diagnosed 14 patients as pulmonary aspergillosis (PA group) among the 21 patients taking into account the chest X-ray findings and the results of the above-stated investigations. The types of chest X-ray findings of these 14 patients were fungus ball type (FB) in 2 patients, productive aspergilloma on the inner wall of a cavity (PAIC) in 8, mixed type with FB and PAIC in 2 and non-specific change in 2. However, there were 3 patients with the chest X-ray findings suggestive of PAIC in 7 patients (non-PA group) who were not diagnosed as pulmonary aspergillosis. Sputum culture were positive in 11 patients of PA group (79%) and negative in all patients of non-PA group. Precipitin antibody were positive in 8 patients of PA group (67%) and negative in all patients of non-PA group. PASTOREX ASPERGILLUS in serum were negative in all 21 patients. PASTOREX ASPERGILLUS in sputum were 3+ (+3) in all 14 patients of PA group and in 2 patients of non-PA group and 2+ (+2) in 2 patients of non-PA group. 12 patients of PA group were treated by antifungal agents and 11 patients responded well to the treatment. We also made sputum culture of Aspergillus and measurement of PASTOREX ASPERGILLUS in sputum on 14 patients (group B) who had respiratory diseases with stable cavities and 17 patients (group C) who had respiratory diseases without a cavity. In group B, sputum culture were positive in 1 patient and PASTOREX ASPERGILLUS in sputum were 3+ (+3) in 2 patients, 2+ (+2) in 1 and 1+ (+) in 2. In group C, sputum culture were negative in all patients and PASTOREX ASPERGILLUS in sputum were 3+ (+3) in 1 patient, 2+ (+2) in 3 and 1+ (+) in 2. Measurement of PASTOREX in sputum was a useful tool to diagnose non-invasive aspergillosis in addition to sputum culture and measurement of precipitin antibody titer. The sensitivity of PASTOREX in sputum was high but its specificity was low, however, its specificity could be raised by applying semi-quantitative analysis of PASTOREX in sputum.

Adult↗
PubMed1996

Changes in urinary enzyme activity and histochemical findings in experimental tubular injury induced by gold sodium thiomalate.

To elucidate the renal injury induced by gold treatment, we administered various doses of gold sodium thiomalate (GST) to Wistar rats and investigated alterations in the urinary enzyme activity, gamma-glutamyl transpeptidase (gamma GTP) and N-acetyl-beta-glucosaminidase (NAG) activity, and histochemical change of enzymes, gamma GTP, alkaline phosphatase (ALP) and acid phosphatase (ACP) activity in the renal tissue. The single administration of a large dose of gold salts induced acute tubular necrosis and enzyme leakage was detected histochemically without damage to the glomerulus. After chronic administration of small doses of gold salts, the urinary gamma GTP activities gradually increased, but urinary NAG activities did not. These findings suggested that the change in urinary enzyme activities, which leaked from inside of brushborder or lysosome, indicated the degree or localization of tubular damage, because renal tubules were selectively injured by gold salts.

Acetylglucosaminidase↗
PubMed1996

Multienzyme control serum (Seraclear-HE) containing human enzymes from established cell lines and other sources. 3: Evaluation as candidate working enzyme reference material for gamma-glutamyltransferase.

Seraclear-HE, containing gamma-glutamyltransferase (GGT, EC 2.3.2.2) derived from the cell culture of a human macrophage cell line, was evaluated as a candidate enzyme reference material (ERM) to calibrate routine methods in terms of a Reference Method for GGT. We have compared this preparation with commercially available materials, including Certified Reference Material 319, at 30 degrees C and 37 degrees C with respect to kinetic properties and with respect to commutability between the Reference Method and each of 15 analytical procedures involving five structurally different donor substrates. GGTs of human origin are far more commutable with reagents of varied types than are GGTs derived from animals. Calibration of 44 patients' sera with Seraclear-HE decreased average intermethod variation from 20% to approximately 4%, whereas GGTs of animal origin showed intermethod variations of approximately 30% with no benefit from calibration. Seraclear-HE is promising as a secondary or working ERM to be used as an intermethod calibrator.

Animals↗
PubMed1995

Circadian rhythms of corneal mitotic rate, retinal melatonin and immunoreactive visual pigments, and the effects of melatonin on the rhythms in the Japanese quail.

We investigated circadian ocular rhythms in the Japanese quail, Coturnix coturnix japonica. The birds were placed under light-dark cycles (LD 12:12), constant light (LL) and constant darkness (DD), and the retinas were dissected out at four-hour intervals throughout 24 h. Following measurements were performed. (1) Melatonin content in the retina was measured by radioimmunoassay. It was low in light and several folds higher in darkness under LD 12:12. The rhythm continued in DD, but disappeared in LL. (2) Mitotic figures in the corneal epithelium were counted. Similar rhythms to the melatonin content were observed in the corneal mitotic rate with a slight phase delay. (3) The retinas were fixed at 4-h intervals and immunostained with anti-bovine rhodopsin serum and anti-chicken iodopsin monoclonal antibodies. The outer segments of photoreceptor cells were stained intensively throughout 24 h in LD 12:12, LL and DD. In contrast, the stainability of the locus close to the outer limiting membrane where the Golgi apparatus exists changed diurnally. Scores showing the ratio of cells with positive staining indicated high values from 4 h after the onset of light to the beginning of dark phase under LD 12:12. The values were high throughout 24 h in LL and intermediate or low in DD. (4) To investigate the effect of melatonin on the corneal mitotic rate and visual pigments at the Golgi region, melatonin was injected into one eye and saline into the contralateral eye. Melatonin induced a phase advance in the corneal mitotic rate under LD 12:12, but did not induce a rhythm under LL.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Effects of restricted feeding on the light-induced body weight change and locomotor activity in the Djungarian hamster.

To investigate the role of food intake in seasonal body weight changes in the Djungarian hamster, we divided animals, which had minimum body weights after 18 wk in SD, into ad-lib feeding and restricted feeding groups under a long day (LD) and a short day (SD) photoperiods. In the ad-lib feeding groups, body weight and food intake increased in parallel after 3 wk under LD and after 6-7 wk in SD because of photorefractoriness. In the restricted feeding groups, almost all animals moved around furiously (food-seeking activity) when they came to consume all the food provided at 2-3 wk of the treatment in LD and after several weeks in SD with the initiation of photorefractoriness, and ended up with death. In the restricted feeding groups, body weight increase was not observed. The furious food-seeking activity in the restricted groups and the increase of body weight specific food intake (food intake/body weight) in the ad-lib feeding groups might reflect the increased requirement for food. This increase of requirement for food seems to be one of the critical factors regulating the seasonal body weight change.

Animals↗
PubMed1995

Local injection of bicuculline into area 8 and area 6 of the rhesus monkey induces deficits in performance of a visual discrimination GO/NO-GO task.

While performing a symmetrically reinforced visual discrimination GO/NO-GO task, five monkeys were injected with a GABAA antagonist, bicuculline methiodide (BMI), into Brodmann's area 9, 8, 6, or 4. The task consisted of five periods: START, OFF, CUE, RESPONSE, and an inter-trial interval. The monkey was trained to make either the GO response (lever release) or the NO-GO response (continued pressing of the lever), depending on the color of the cue, during the RESPONSE period. Analysis was limited to 102 sites in which muscle convulsions of the forelimb and/or shoulder did not result from BMI injections. Errors in performance increased 10-60 min after injection into 10 of 33 sites in area 9, 9 of 25 sites in area 8, 20 of 34 sites in area 6, and 2 of 10 sites in area 4. The number of trials finished in a 120-min session decrease. Injections induced PRE-RESPONSE errors (release of the lever in either the OFF or CUE periods), GO RESPONSE errors (failure to release the lever when signaled), and NO-GO RESPONSE errors (release of the lever despite a signal not to release). The results suggest that both areas 8 and 6 are involved in correct performance of the GO/NO-GO task.

Animals↗
PubMed1995

An in vitro culture method for chick embryos obtained from the anterior portion of the magnum of oviduct.

1. Chick embryos, obtained from the anterior portion of the magnum of the oviduct 60 to 80 min after the preceding egg had been laid, were cultured in vitro in small and large recipient eggshells until hatching. 2. Of 82 embryos cultured, 46.3% had survived to day 4 of incubation, and 19.5% survived to hatching. 3. The method for culturing embryos used in this experiment could facilitate research on the in vitro manipulation of early chick embryos.

Animals↗