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Biomedical subjects

M Tabata

Publications and source records attributed to M Tabata.

At least 235 records · Page 13Linked to original sources
PubMed1988

Multiple cytokine activities and loss of interleukin 2 inhibitor in synovial fluids of patients with rheumatoid arthritis.

Attempts to detect immune mediators in rheumatoid arthritis synovial fluids (RA-SF) by bioassays have yielded conflicting results, and so we analyzed the immune reactions occurring within rheumatoid joints using monospecific immunoassays for cytokines such as interleukin 1 beta (IL-1 beta), interleukin 2 (IL-2) and gamma interferon (gamma-IFN). Furthermore, we examined the IL-2 inhibitors to clarify the immunoregulatory mechanism in the lesion. SF from active RA contained a significant amount of IL-1 beta and IL-2 but not gamma-IFN. In contrast IL-2 inhibitor activity was depressed in RA-SF regardless of clinical disease activity. Our results suggest that cytokine overproduction and deficiency of inhibitory signals may result in the overactivity of cytokines and the overactivity may participate in the joint lesions of RA.

Antibodies, Monoclonal↗
PubMed1988

Involvement of retinal and extraretinal photoreceptors in the mediation of nocturnal locomotor activity rhythms in the catfish, Silurus asotus.

Retinal and extraretinal photoreceptor organs involved in synchronization of nocturnal locomotor activity under 12-h light:12-h dark cycle (LD12:12) were investigated in catfish, Silurus asotus. Catfishes studied were: (1) intact; (2) pinealectomized; (3) blinded; (4) blinded and pinealectomized; and (5) blinded, pinealectomized, with the brain region covered with aluminum foil. When the light intensity was reduced during the light phase of the LD cycle, the threshold for 24-h rhythmicity was determined, by observing the synchronization to the given LD cycle with periodograms. Intact catfish showed almost the same threshold intensity (in the order of 10(-3) microW/cm2) as that of either blinded or pinealectomized animals. This suggests that information is combined through both organs and is related to the 24-h rhythm of locomotor activity at lower intensities. However, the animal without the eye and pineal organ could display 24-h rhythmicity at intensities higher by approximately 3 log units than those of the animals described above. This indicates the existence of extraretinal and non-pineal photoreceptors (ENPs), and the involvement of at least three types of photoreceptor in mediating nocturnal locomotor activity rhythms at higher intensities. One of the possible ENPs was assumed to be in the brain region.

Animals↗
PubMed1987

Nonbacterial transformation of bilirubin in bile.

Bilirubin present in gallstones is mainly in the unconjugated form despite the frequent absence of bacteria in bile. The aim of the present study was to determine if nonbacterial beta-glucuronidase activity and/or nonenzymatic hydrolysis is responsible. Inflammatory cells such as polymorphonuclear leukocytes and lymphocytes appearing with the presence of brown pigment gallstones and inflammation in biliary tract was shown to effect deconjugation of bilirubin conjugates in bile and contribute to their formation in addition to that of bacterial beta-glucuronidase. Gallbladder bile (mean +/- SD, 4.0 +/- 1.6%, N = 29) contained more unconjugated bilirubin than hepatic bile (mean +/- SD, 2.7 +/- 1.1%). In vitro experiments showed the deconjugation to take place during incubation at 37 degrees C without the presence of bacteria. Therefore, transformation of conjugated to unconjugated bilirubin is likely to take place in vivo during the storage in gallbladder, and nonbacterial beta-glucuronidase activity and/or nonenzymatic hydrolysis may be responsible for such transformation.

Bacteria↗
PubMed1987

Incidence of ovarian metastasis in patients with cancer of the uterine cervix.

During the period from 1970 to 1985, 706 patients with cervical cancer of stage 0 and Ia were treated by a simple hysterectomy without oophorectomy. In 326 patients with invasive carcinoma in stage Ib to stage III, who were treated by a radical hysterectomy from 1977 to 1985, histological examinations were performed to detect ovarian metastasis. A total of 674 autopsy specimens were obtained from the Annual of the Pathological Autopsy Cases in Japan. (Japanese Pathological Society, 1965 to 1978). Follow-up observations on stage 0 and stage Ia revealed no recurrence in the ovaries. In invasive cases of epidermoid carcinoma (stage Ib to stage III), no ovarian metastases were detected, despite discovery of metastases to the pelvic lymph node in 21.6% of the cases. Conversely, in the cases of cervical adenocarcinoma (pure adenocarcinoma and mixed carcinoma), 6 of 48 cases (12.5%) showed ovarian metastases. Ovarian metastases were found in 22 of 77 (28.6%) autopsy cases of adenocarcinoma, but in only 104 of 597 (17.4%) cases of epidermoid carcinoma. This finding is statistically significant (P less than 0.02). Both corpus invasion and metastasis to the ovaries were found in 20 of 54 cases (37.0%). This rate was significantly higher than the rate of ovarian metastasis in cases without corpus invasion (P less than 0.001).

Adenocarcinoma↗
PubMed1987

Use of a bioreactor consisting of sequentially aligned L-glutamate dehydrogenase and L-glutamate oxidase for the determination of ammonia by chemiluminescence.

A chemiluminometric method for the automated flow injection analysis of ammonia is described. The essence of the invention is the use of a bioreactor consisting of both immobilized L-glutamate dehydrogenase (GLDH) and L-glutamate oxidase (GLXD), which are sequentially aligned in this order in a minicolumn measuring 2.0 X 20 mm. The unidirectional constant flow of liquid through the column reactor minimizes the reversed diffusion of the solutes so that the following sequence of reactions is ensured. Thus, ammonia to be determined is first transformed by GLDH into L-glutamate, which then produces hydrogen peroxide by GLXD. Hydrogen peroxide in the effluent from the column is then determined by its chemiluminescence upon admixing with luminol and potassium ferricyanide. The present method gives linearity of the standard curve for ammonia up to 1.0 mM. It is at least 100 times more sensitive than the conventional method for ammonia assay using ultraviolet absorption measurement.

Amino Acid Oxidoreductases↗
PubMed1987

Inhibition of interleukin 2 by serum in healthy individuals and in patients with autoimmune disease.

To study the mechanisms that regulate the activity of interleukin 2 (IL 2) and possibly limit its activity, we have examined normal human serum for its ability to inhibit IL 2-mediated proliferation of a cloned IL 2-dependent cytotoxic T lymphocyte line (CTLL). Normal human serum contains a factor capable of inhibiting IL 2 dependent proliferation of CTLL cells. This factor is absorbed with the cells but not IL 2 molecules. The inhibitor is heat-labile and inactivated by trypsin treatment. The molecular weight of the inhibitor is 70,000-220,000. The imbalance of the inhibitor is observed in serum from patients with autoimmune disease including systemic lupus erythematosus and rheumatoid arthritis. These results suggest that the serum IL 2 inhibitor may play an important role in the in vivo regulatory mechanism of IL 2 activity and in aberrant immune functions in humans.

Arthritis, Rheumatoid↗
PubMed1987

Deficiency of interleukin 2 inhibitor activity in serum from autoimmune-prone mice.

To study the mechanisms that regulate the activity of interleukin 2 (IL 2) and possibly limit its activity, we have examined normal mouse serum for their ability to inhibit IL 2-mediated proliferation of a cloned IL 2-dependent cytotoxic T lymphocyte line (CTLL). Normal mouse serum contains a factor capable of inhibiting IL 2 dependent proliferation of CTLL cells. This factor is absorbed with IL 2-dependent cells, but not with IL 2 molecules. Decreased activity of the inhibitor is observed in serum from autoimmune-prone mice such as NZB and NZBWF 1 hybrid mice. The results suggest that the serum IL 2 inhibitor may play an important role in the in vivo regulatory mechanism of IL 2 activity and that lack of the inhibitor may be associated with aberrant immune functions.

Animals↗
PubMed1987

Biosynthesis and secretion of the third component of complement by human endothelial cells in vitro.

The third component of complement (C3) is synthesized and released by cultured human capillary endothelial cells. After the incubation of cells in a methionine-free medium containing 35S-methionine for 48 hr, culture supernatants were immunoprecipitated with anti-human C3 serum. SDS solubilization and 2-ME reduction of the immunoprecipitates, followed by separation with SDS-polyacrylamide gel electrophoresis and autoradiography, revealed two major bands comparable to those of the alpha and beta chains of human C3. The content of C3 in the culture medium harvested at different time-intervals was determined by ELISA. The C3 secretion rate was about 250 ng/10(6) cells/5 days in the primary culture medium and 75 ng/10(6) cells/5 days after seven passages. The capillary endothelial cells described here have factor VIIIRAg specific for endothelial cells, and exhibit ring formation resembling capillary lumina, but they lack Weibel-Palade bodies.

Antigens↗
PubMed1987

[Pathological study of ovarian metastasis in cervical cancer].

During the period from 1977 to 1986, 860 patients with cervical cancer were examined ovarian metastasis in our department. Four hundred and seventy seven patients of stage 0 and Ia were treated by a simple hysterectomy without oophorectomy. Follow-up examinations on these stages revealed no recurrence in the ovaries and 5 year survival rate is 100%(239/239). In 383 patients with invasive carcinoma in stage Ib to stage III, who were treated by radical hysterectomy, histological examinations were performed to detect ovarian metastasis. In invasive cases of epidermoid carcinoma(stage Ib to stage III), no ovarian metastases were detected, despite discovery of metastases to the pelvic lymph node in 22.3% of the cases. Conversely, in the cases of cervical adenocarcinoma(pure adenocarcinoma and mixed carcinoma), 9 of 74 cases(12.2%) showed ovarian metastases even in early histologic stages. It is noteworthy that seven of nine cases had no lymph node metastasis. Only endocervical type had ovarian metastasis in pure adenocarcinoma. In mixed carcinoma, metastatic lesion of ovary is adenocarcinoma.

Adenocarcinoma↗
PubMed1986

Stimuli that produce sensitization lead to elevation of cyclic AMP levels in tail sensory neurons of Aplysia.

Facilitation of synaptic connections between sensory neurons and motor neurons mediating the tail withdrawal reflex in Aplysia is produced by the modulatory effects of sensitizing stimuli. Facilitation can be mimicked by perfusing these neurons with serotonin (5-HT) in a semi-intact preparation. Consequently, 5-HT has been presumed to be acting as an agonist of the modulatory transmitter that mediates sensitizing input in vivo. While the 5-HT effects appear to be mediated by increased cyclic adenosine monophosphate (cAMP) levels in the sensory neurons, a critical issue that has not been examined is whether sensitizing stimuli also increase cAMP levels in these cells. We now report that such sensitizing stimuli delivered to the tail of a semi-intact preparation lead to elevation of cAMP levels in the tail sensory neurons.

Animals↗
PubMed1986

The effects of reduced glutathione and cysteine on prostaglandin synthesis in rabbit kidney medulla slices.

The effects of GSH and cysteine on the generation of medullary prostaglandins E2 and F2 alpha were examined. The formation of prostaglandin E2 was enhanced by GSH, but was reduced by cysteine in a dose-related manner. GSH inhibited prostaglandin F2 alpha production, while cysteine stimulated it. These results suggest that GSH and cysteine have contrary effects on prostaglandins E2 and F2 alpha synthesis by affecting endoperoxide E2 isomerase or endoperoxide reductase.

Animals↗
PubMed1986

[Changes in the forearm tcPO2 following the cold water immersion test].

The purpose of this study is to apply changes in forearm transcutaneous PO2 (tcPO2) during the cold water immersion test (5 degrees C, for 10 min) to the diagnosis of vibration syndrome. Forearm tcPO2 in healthy controls increased gradually up to 3 min after the start of the cold water immersion and decreased thereafter. It returned to almost the same level before immersion 5 min after the start. In the workers using vibrating tools manifesting Raynaud's phenomenon, forearm tcPO2 also increased up to 3 min after the start as in healthy controls, but no change was observed thereafter. The difference between the level of forearm tcPO2 at 3 min and that at 10 min after the start of the immersion (Forearm tcPO2 recovery index, newly devised by authors) in workers using vibrating tools was significantly lower than that in healthy controls. Therefore, investigation of changes in forearm tcPO2 following the cold water immersion test is considered to be a useful objective item which can contribute to the diagnosis of vibration syndrome.

Aged↗