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Biomedical subjects

M Kuwabara

Publications and source records attributed to M Kuwabara.

At least 19 recordsLinked to original sources
PubMed1995

The suppression of age-related accumulation of lipid peroxides in rat brain by administration of Rooibos tea (Aspalathus linearis).

The protective effects of Rooibos tea (RT), Aspalathus linearis, against damage to the central nervous system (CNS) accompanying aging were examined by both the thiobarbituric acid reaction (TBA) and magnetic resonance imaging (MRI) methods in brains of chronically RT-treated rats. Ad libitum administration of RT was begun with 3-month-old Wistar female rats and continued for 21 months. The contents of TBA reactive substances (TBARS) in the frontal cortex, occipital cortex, hippocampus and cerebellum in 24-month-old rats after administration with water were significantly higher than those in young rats (5 weeks old). However, no significant increase of TBARS was observed in RT-administered aged rats. When MR images of the brains of 24-month-old rats with and without RT as well as 5-week-old rats were taken, a decrease of the signal intensity was observed in the cerebral cortex, hippocampus and cerebellum in MR images of aged rats without RT, whereas little change of the signal intensity was observed in MR images of the same regions of 24-month-old rats treated with RT, whose images were similar to those of young rats. These observations suggested that (1) the age-related accumulation of lipid peroxides in the brain was closely related to the morphological changes observed by MRI, and (2) chronic RT-administration prevented age-related accumulation of lipid peroxides in several regions of rat brain.

Administration, Oral↗
PubMed1995

Correlation between canine NK cell mediated cytotoxicity and radical production.

We investigated the relationship between natural killer (NK) mediated cytotoxicity and radical production in canine peripheral blood lymphocytes (PBLs). Canine NK cell mediated cytotoxicity, measured by 51Cr release assay, was found to be the highest in the T-cell (Thymus cell) subpopulation which partitioned into the 35-40% percoll fraction by centrifugation through a discontinuous gradient. Radical production showed a similar tendency in luminol-dependent chemiluminescence (CL) assay. Furthermore, enrichment of large granular lymphocytes (LGL) was observed in the cell fraction from the same percoll density. These results suggest that NK cell mediated cytotoxicity is related to radical production in canines.

Animals↗
PubMed1995

Release of natural killer cytotoxic factor (NKCF) from canine natural killer (NK) cells stimulated with cytoplasmic membrane of target cells.

The presence of canine natural killer cytotoxic factor (NKCF) and the mechanism of the release of the NKCF by canine natural killer (NK) cells were studied. The cytotoxicity in the culture supernatant of effector cells cultured with target cells was dependent on the count of NK cells. Therefore, this suggests that the cytotoxic factor in this culture supernatant is NKCF. The NK-sensitive live target cells stimulated the release of NKCF from NK cells, but the NK-insensitive target cells did not. Moreover, NKCF was also released from NK cells stimulated with either killed target cells or their cytoplasmic membrane as well as live target cells. These findings suggest that the structure of the cytoplasmic membrane of target cells is involved in the recognition, binding and the release of NKCF by NK cells.

Animals↗
PubMed1995

alpha-Phenyl N-tert-butyl nitrone (PBN) increases the cortical cerebral blood flow by inhibiting the breakdown of nitric oxide in anesthetized rats.

The effects of intravenous administration of alpha-phenyl N-tert-butyl nitrone (PBN) on cortical cerebral blood flow (CBF) were examined in Wistar rats under pentobarbital anesthesia and artificial ventilation. The cortical CBF in parietal cortex was measured by laser Doppler flowmetry. Intravenous administrations of 2 mg/kg and 20 mg/kg of PBN dose-dependently produced significant increases in cortical CBF and decreases in systemic blood pressure (BP). To examine whether these increased responses in cortical CBF produced by PBN were associated with the vasodilatation system of nitric oxide (NO), the NO synthase inhibitor L-NG-nitroarginine (L-NOArg), which is an analog of L-arginine, was used to inhibit the NO-related-vasodilatative system. Since the PBN-induced responses in the cortical CBF were much attenuated in L-NOArg-treated rats (30 mg/kg, i.v.), it was inferred that NO-related vasodilatation was strongly associated with the PBN-induced increase in cortical CBF.

Amino Acid Oxidoreductases↗
PubMed1995

[Enzyme immunoassay (EIA) as an assay system of tumor markers].

To detect a small amount of tumor marker in the serum, the development of a sensitive assay system has been tried. In the beginning radioimmunoassay was mainly employed. But the use of radioisotope has been undesirable because the special facilities to treat radioactive substance or to discard it are required. For this reason the various assay systems without the radioisotope have been developed. Among them EIA system is in the mainstream, especially for the determination of CEA and AFP. Recent analysis shows the increasing trend of the employment of EIA for the determination of other tumor markers. In EIA system it is critical to keep the regulation of reaction time to be obtain the accurate value. Autoassay system is favorable for this problem. It is also another problem that discrepancies of assayed value are seem among the different assay kits. In the clinical use of tumor marker the comparison of the serial data, even if they are obtained from the different hospitals, is important. So overcoming this problem is desirable.

Automation↗
PubMed1995

[Desensitization immunotherapy on patients with mite-positive bronchial asthma using purified mite feces antigen fractions].

At present, we are performing desensitization immunotherapy on patients with mite-positive bronchial asthma using purified mite feces antigen fractions. We obtained the following results in 13 patients 4 to 12 months after the start of treatment. 1) The fraction showing the maximum reaction in the skin test was HM1-2 (molecular weight: 150-155 kD) in two patients, HM2 (30-40 kD) in nine patients and HM3 (10-20 kD) in two patients, and immunotherapy was performed using these fractions. None of the patients showed the maximum skin reactions or was treated with HM4 (less than 10 kD). 2) In nine patients with perennial asthma, the effects of treatment were excellent in four and moderate in three, while two cases remained unchanged. In four patients with seasonal asthma, the treatment was effective in all cases. 3) In patients in whom immunotherapy was effective, specific IgG antibody increased after the treatment, but it did not increase in the unchanged cases. Among the subclasses of specific IgG antibody increased by the treatment, no clear changes were seen in IgG4 antibody and no conclusion has been reached at present. 4) None of the patients had definite adverse reactions such as the occurrence of asthma attacks or anaphylaxis. These results suggested that purified mite feces antigens are safe and effective. We plan to continue this study with more patients in the future.

Adolescent↗
PubMed1995

[A case of mediastinal fibrosarcoma].

Mediastinal fibrosarcoma is rare and comprises only 0.18% of mediastinal tumors. A case of mediastinal fibrosarcoma is reported. A 57-year-old woman was admitted to our hospital with a chief complaint of chest oppression. Computed tomogram and magnetic resonance imaging revealed an anterior mediastinal tumor expanding beneath the diaphragm. The tumor invaded the pericardium, the left lung and the diaphragm, so extensively resected. The resection was non-curative because of the presence of bloody pericardial effusion and maligant stump of the pericardium. Pathological examination showed fibrosarcoma. Although she recovered well postoperatively, she died with recurrence of the tumor, especially direct oppression of the heart, 8 months after the operation. In this case adjuvant chemotherapy did not effective and noncurative operation did not improve the prorhylaxis.

Female↗
PubMed1995

[Recurrent bronchogenic cyst--a case report].

Mediastinal bronchogenic cyst is a benign tumor and occupied about 5% of mediastinal tumor in Japan. As a benign tumor, recurrence of bronchogenic cyst is very rare, and we found only 2 cases were reported. We experienced a recurrent bronchogenic cyst found 14 years after first operation. The patient was 56-year-old male, and admitted to our hospital for further evaluation of his abnormal shadow on chest roentogenogram. He had no symptoms. He was operated an bronchogenic cyst for 14 years ago. Chest X-ray, CT, and MRI demonstrated a paratracheal cystic mass which was suspected of a recurrent bronchogenic cyst. An operation was done, and the tumor was resected. A histopathological study showed that the tumor had thin wall and had a ciliated epithelium, then it was diagnosed bronchogenic cyst. The most likely explanation for the recurrence in our patient is an incomplete resection during the initial operation. It is though that only a very small amount of epithelial tissue need remain for recurrence. For prevention of recurrence, complete resection of cyst is necessary, and long-term follow-up is indicated to detect recurrence.

Bronchogenic Cyst↗
PubMed1994

Serum glutathione S-transferase-pi level as a tumor marker for non-small cell lung cancer. Potential predictive value in chemotherapeutic response.

BACKGROUND: Resistance to chemotherapeutic agents is a major problem in non-small cell lung cancer (NSCLC) chemotherapy, and recent studies have indicated that glutathione S-transferase-pi (GST-pi) may play an important role in the resistance of cancer cells to alkylating agents that include platinum compound. METHODS: GST-pi in serum of 121 patients with NSCLC was measured by a sandwich enzyme-linked immunosorbent assay, and the serum concentrations of carcinoembryonic antigen (CEA), squamous cell carcinoma (SCC) antigen, and neuron-specific enolase (NSE) were also examined. Serum levels of these tumor markers were also evaluated in relation to therapeutic response in 69 patients who received combination chemotherapy with platinum compound. RESULTS: Fifty of 121 patients with NSCLC (41.3%) showed elevated serum GST-pi levels above a cutoff value of 34.8 ng/ml (mean + two standard deviations in 30 healthy control subjects). The positive rate of GST-pi in patients with NSCLC was higher than those of CEA (37.2%), SCC (15.7%), and NSE (14.9%). The mean pretreatment GST-pi level was significantly lower in patients with a partial response to chemotherapy than in those with no response (26.9 +/- 11.3 ng/ml versus 38.8 +/- 16.7 ng/ml; P < 0.003). Among patients with elevated levels of pretreatment serum GST-pi, only 13.8% (four of 29) responded to the combination chemotherapy, whereas partial response was observed in 40.0% of patients (16 of 40) with serum GST-pi concentration below the cutoff level (P < 0.02). Neither CEA, SCC, nor NSE showed such a relationship. CONCLUSIONS: The serum GST-pi level may have limited value as a tumor marker for NSCLC: Interestingly, pretreatment serum GST-pi levels may be a useful parameter for predicting therapeutic response to combination chemotherapy regimens that include platinum compound.

Adult↗
PubMed1994

Induction of lung tumors in C3H strain mice after single or fractionated irradiation with X-rays.

Murine model for lung tumor induction was studied in C3H/He male mice, a strain with low spontaneous incidence of lung tumors. Dose-response relationships in lung tumor induction were compared following irradiation with single doses and split doses of X-rays to the thorax either at night or in the daytime. The tumor incidence after a single 1.25 Gy dose at night during the period of nocturnal activity almost reached the maximum level after a 5 Gy dose in the daytime. Proliferative activity determined by observing the labeling index with tritiated thymidine in the normal lung was low as a whole, but tended to decrease in the daytime. When the proliferative response was induced by X-irradiation, significantly higher activity was observed at night. These circadian fluctuations were thought to affect radiosensitivity and lung tumor induction in mice. When split doses or fractionated doses of X-rays were applied to the thorax, lung tumor incidence definitely increased. The incidence after two 7.5 Gy doses with a 12 hr-interval was 41%, 3-fold higher than that after a single 15 Gy dose. Moreover, fractionated whole body irradiations (three times at 3 Gy with 3-month-interval) after a single 7.5 Gy thoracic irradiation was most effective in increasing not only the incidence (47%) but also the multiplicity of the lung tumor. More than 30% of tumor-bearing mice had two or more tumors following thoracic and whole body irradiations, while only 10% of tumor-bearers had multiple tumors after single or fractionated thoracic irradiation alone.

Animals↗
PubMed1994

Magnetic resonance imaging of young and aged rat brains under a magnetic field of 7.05 T.

Using a homemade MR imaging probe (Helmoholtz coil), MR images of brains of 5-week-old and 23- or 24-month-old Wistar rats were taken under a magnetic field of 7.05 T (Tesla). The probe was designed to fit the rat head and made by winding thin copper film round an acrylic tube with a 5-cm i.d., 10-cm length and 2-mm thickness. This was adjusted to resonate with the 300 MHz radiofrequency corresponding to the resonance frequency of 1H under a magnetic field of 7.05 T. MR images were obtained by T1-weighted and two-dimensional Fourier transformation techniques. The sagittal and coronal sections were imaged in 1-mm-thick slices. The size of the data matrix was 128 phase-encoded steps. Each image was obtained through eight acquisitions. A comparison of the MR images with those semi-microscopically taken at the same position of the coronal section revealed that the cerebral cortex, hippocampus, hypothalamus and thalamus were clearly imaged by this probe. With aging, MR images of cerebral cortices were observed with decreased signal intensities. Enlargement of the third ventricles and hypertrophy of cranical parietal bones were also recognized in sagittal MR images of aged rats. These observations were more marked in males than in females. From these observations it was concluded that this probe was applicable for MR imaging of rat brains under a magnetic field of 7.05 T.

Aging↗
PubMed1994

Characterization of new inbred strains of Dahl-Iwai salt-sensitive and salt-resistant rats.

Dahl-Iwai salt-sensitive (S) and salt-resistant (R) rat strains were newly established as inbred strains. To characterize the strains, the Dahl-Iwai S and R rats were fed low-salt (0.3% NaCl) and high-salt (8.0% NaCl) diets from 5 weeks after birth, and systolic blood pressure and pathologic findings were examined at intervals. The distributions of alleles at 19 biochemical and immunologic loci also were examined in the aforementioned strains, together with those for the inbred SS/Sea and SR/Sea strains, which were derived from inbred SS/Jr and SR/Jr strains, respectively. The Dahl-Iwai S rats were hypertensive after 3 weeks of consuming the 8.0% NaCl diet and died from 6 to 10 weeks after the diet was initiated. Renal lesions developed after 4 weeks' consumption of the high-salt diet. The Dahl-Iwai S rats were not hypertensive until at least the age of 21 weeks while they consumed the 0.3% NaCl diet, whereas it was reported that the SS/Jr rats became hypertensive at about 20 weeks of age when they consumed the low-salt diet. The Dahl-Iwai R rats were normotensive whether fed the 0.3 or 8.0% NaCl diet. Hydronephrosis was not observed in the Dahl-Iwai R rats, though it develops in SR/Jr rats with high frequency. Different distributions were detected for kidney alkaline phosphatase-1 (Akp-1) and amylase-1 (Amy-1) alleles between the Dahl-Iwai S and SS/Sea strains, and for esterase-14 (Es-14) and seminal vesicle protein-1 (Svp-1) alleles between the Dahl-Iwai R and SR/Sea strains. The phenotypic differences between the substrains of inbred Dahl rats could be ascribed to different genetic backgrounds.

Aging↗
PubMed1994

[Amebic empyema, a case report].

A 49-year-old man was admitted to our hospital for dyspnea. Chest X-ray examination showed a massive right pleural effusion. Using intrathoracic tube drainage, a large quantity of chocolate-like pleural effusion was removed. Laboratory data demonstrated severe anemia and hypoproteinemia, and TPHA was positive. Antiameba antibody in blood was high, and a liver abscess was demonstrated on abdominal CT scan. Amebic liver abscess and amebic empyema were thus diagnosed. With pleural tube drainage and percutaneous liver abscess drainage, metronidazole (1.5 g/day) was administered. After administering this drug, the high temperature normalized and the patient's general condition improved significantly. Recently, amebic infections have been reported in increased numbers, especially in male homosexuals and immunocompromised patients. Henceforth amebic infection should be considered when pleural effusion and empyema are suspected.

Empyema, Pleural↗
PubMed1994

[Clinical efficacy of arbekacin in deep MRSA infection. Including follow-up study after the termination of chemotherapy].

We analyzed the efficacy of arbekacin (ABK) using monotherapy or combined therapy on deep MRSA infection to find the most adequate usage of the drug. We also followed-up the isolation incidence of MRSA after the end of chemotherapy. The results are summarized as follows: 1. Clinical efficacy of ABK on 29 pneumonia and 3 septicemia due to MRSA was 42.9% in ABK monotherapy (9 patients), 62.5% in combined therapy with ABK and minocycline (9 patients), 100% with ABK and imipenem/cilastatin (IPM/CS) (7 patients), and 100% with ABK and other drugs (7 patients). 2. As for microbiological efficacy, combined therapy with ABK and IPM/CS or other drug was superior to other methods. Among patients from whom two or more species of bacteria were isolated, causative bacteria persisted in many cases, and some replacements occurred. 3. Kidney functions deteriorated in two patients that underwent monotherapy or combined therapy with ABK and IPM/CS, but they recovered when therapy was completed the completion. 4. In the three month follow-up study after ABK therapy, we found four cases of renewed infections after disappearance of MRSA. When just decreases in the number of MRSA resulted upon the chemotherapy, the relapse occurred in all cases. 5. Above results indicate that ABK is effective in MRSA infection, and combined therapy with beta-lactams is superior to other methods in serious MRSA infections. We also suggest that chemotherapy should be continued until the complete disappearance of MRSA is achieved.

Adult↗