Biomedical subjects

K Nakata

Publications and source records attributed to K Nakata.

At least 325 records · Page 18Linked to original sources

PubMed1993

Appearance of gamma delta T cell receptor-positive cells following alpha beta T cell receptor-positive cells in the lepromin reaction of human skin.

To elucidate the involvement of human gamma delta T cell receptor (TcR)+ cells in mycobacterial infection, we examined the kinetics of these cells in skin lesions of human lepromin reaction. The majority of CD3+ cells two days after induction of the lepromin reaction were alpha beta TcR+, while gamma delta TcR+ cells accounted for only 4.4 +/- 1.4% of the CD3+ cells. On day 21, the incidence of gamma delta TcR+ cells was greater (16.0 +/- 2.1%), although alpha beta TcR+ cells remained the predominant population. These kinetics of alpha beta TcR+ cells and gamma delta TcR+ cells contradict the 'early response, self-surveillance' hypothesis for gamma delta TcR+ cells in mice. Most of the gamma delta TcR+ cells in this study of the lepromin reaction were V delta 1- V delta 2+ V delta 9+, and some of them proliferated in the skin lesions, suggesting that gamma delta TcR+ cells in the lesions may respond to mycobacterial antigens and may play an active part in the lepromin reaction. However, these gamma delta TcR+ cells were not correlated with granuloma formation, the size of necrotic areas, mycobacterial content, or the incidence of CD4+ cells and CD8+ cells.

Fluorescent Antibody Technique↗

PubMed1993

Gamma delta T-cell receptor-positive cells in human skin. I. Incidence and V-region gene expression in granulomatous skin lesions.

BACKGROUND: There have been many reports that gamma delta T-cell receptor (TCR)+ cells respond to mycobacterial antigens in vitro, but there is little available information on human gamma delta TCR+ cells in clinical conditions. OBJECTIVE: Our purpose was to investigate the distribution and involvement of human gamma delta TCR+ cells in granulomatous skin lesions. METHODS: The incidence and V-region gene expression of human gamma delta TCR+ cells was examined in granulomatous skin diseases, including cutaneous tuberculosis and leprosy, by immunohistochemical procedures. RESULTS: gamma delta TCR+ cells in the dermis were increased in most patients with borderline lepromatous leprosy, and they were less frequently found in lepromatous leprosy and erythema nodosum leprosum. Other granulomatous skin lesions, including sarcoidosis, contained only a few gamma delta TCR+ cells. The gamma delta TCR+ cells that were found to be increased in this study were mostly delta TCS1-, BB3+, Ti gamma A+ (V delta 1-, V delta 2+, V gamma 9+). CONCLUSION: The gamma delta TCR+ cells in human granulomatous skin lesions may respond to some mycobacterial antigens, but they do not appear to be directly involved in granuloma formation.

Gene Expression↗

PubMed1993

Restorative effect of short term administration of thymulin on thymus-dependent antibody production in restraint-stressed mice.

Thymulin is a well defined nonapeptide produced by thymic epithelial cells, and plays an important role in thymocyte differentiation. We investigated the restorative effect of thymulin on the stress-induced reduction in the production of antibodies against SRBC in mice. Antibody production in stressed mice was reduced to about 50% of that in normal mice. A 3-day period of administration of thymulin (1 ng/kg) restored antibody production to close to the normal level, whereas thymulin (1 ng-1 microgram/kg) did not affect antibody production in normal mice. These results indicated that thymulin normalizes the altered thymus-dependent immune responses.

Animals↗

PubMed1993

Hepatic failure after partial hepatectomy due to synergism between endotoxaemia and congestion of the liver.

To determine whether hepatic failure after partial hepatectomy is due to synergism between endotoxaemia and congestion of the liver, we examined endotoxin hepatotoxicity in partially hepatectomized rats with and without congestion of the liver. In partially hepatectomized rats without congestion of the liver, endotoxin administration induced slight elevation of the serum transaminase activity and mild or moderate hepatocellular necrosis in a few rats: these findings were not significantly different from those in sham operated rats treated with endotoxin. On the other hand, in partially hepatectomized rats with congestion of the liver, endotoxin administration induced marked elevation of serum transaminase activity and moderate or severe hepatocellular necrosis in almost all rats: these findings were significantly different from those in endotoxin-treated partially hepatectomized rats without congestion of the liver. These experimental data suggest that synergism between endotoxaemia and congestion of the liver may be a cause of hepatic failure after partial hepatectomy.

Animals↗

PubMed1993

Effect of exogenous antioxidant enzymes and antioxidants on the development of endotoxin-induced hepatocellular necrosis in rats.

To determine whether released oxidants in endotoxemia contribute to the development of hepatocellular necrosis, we examined the effects of antioxidants and antioxidant enzymes on endotoxin hepatotoxicity in rats. In rats given endotoxin, focal and random hepatocellular coagulative necrotic areas with infiltration of polymorphonuclear leukocytes and mononuclear cells and an elevation of serum transaminase activities were found. The extent of hepatocellular necrosis and the level of serum transaminase activities were not significantly decreased by treatment with superoxide dismutase, catalase, alpha-tocopherol or allopurinol. These experimental data indicate that even if endotoxin is related to a release of oxidants, the oxidants do not appear to play an important role in the development of hepatocellular necrosis.

Allopurinol↗

PubMed1993

Augmentation of endotoxin hepatotoxicity by zinc.

The present study was undertaken in rats to determine whether zinc protects against endotoxin hepatotoxicity and mortality. Treatment with zinc (50-200 mumol/kg body weight) alone or endotoxin (lipopolysaccharide B, Escherichia coli 026:B6, Difco, 2 mg/kg body weight) alone did not induce significant morphological changes in the liver parenchyma or any abnormalities in liver function tests. The mortality rate was 0%. In the rats pretreated with 100 mumol of zinc and then injected with endotoxin, the mortality rate, the incidence of focal hepatocellular coagulative necrosis and serum transaminase activity increased markedly. Eleven of the 12 rats pretreated with 200 mumol of zinc died within 4 h after endotoxin injection. In the rats pretreated with 50 mumol of zinc and then injected with endotoxin, there was no conspicuous change, in the mortality rate, liver function tests or morphology of the liver. These experimental data indicate that zinc increases the mortality rate in endotoxemic rats and augments biochemical and morphological evidence of endotoxin hepatotoxicity.

Animals↗

PubMed1993

Influence of chronic alcohol consumption on the development of altered hepatocellular foci in rats.

The effect of chronic alcohol consumption on the development of altered hepatocellular foci was examined in 150 male Slc:Wistar rats fed an ethanol solution (0, 5 or 20%, w/v) ad libitum instead of drinking water. In the 120th week of the treatment period, the liver was examined histopathologically. There was no significant difference in the incidence, number and volume fractions of altered hepatocellular foci between the 0% and the 5% ethanol groups. In the 20% ethanol group, the incidence of altered hepatocellular foci was significantly higher than in the 0% ethanol group, and the number and the volume fraction of altered hepatocellular foci were significantly greater than in the 0% and the 5% ethanol groups. These results indicate that chronic consumption of a large amount of alcohol promotes the development of altered hepatocellular foci. However, there was no statistically significant difference in the incidence of benign liver cell tumours and hepatocellular carcinoma among the three groups.

Alcohol Drinking↗

PubMed1993

Role of microenvironmental deterioration of the bone marrow in the development of bone atrophy in magnesium silicate-treated rats.

The role of microenvironmental deterioration of the bone marrow in the development of bone atrophy was examined in rats with bone atrophy induced by magnesium silicate. In the tibial metaphyses, proliferation of myelocytic elements of haematopoietic tissue was prominent and caused narrowing of sinusoids, increased distance between sinusoids and trabecular bone and atrophy of trabecular bone. There was a significant correlation in volume percentage between haematopoietic cells and trabecular bone, between haematopoietic cells and sinusoids and between sinusoids and trabecular bone. These results imply that atrophy of trabecular bone is related to microenvironmental deterioration of the bone marrow, that is, a decrease in efficiency of exchange of nutrients and waste products between sinusoids and trabecular bone due to the proliferation of haematopoietic cells and a deficiency of nutrient supply to the bone marrow due to the narrowing of sinusoids.

Animals↗

PubMed1993

Microvascular events in bone marrow related to development of and recovery from bone atrophy in thiotepa-treated rats.

To clarify the relationship of microvascular events in the bone marrow to the development of and the recovery from bone atrophy, we examined quantitatively and qualitatively trabecular bone, sinusoids and haematopoietic tissue in the metaphysis of the tibia of rats given thiotepa, an antitumour drug derived from nitrogen mustards. The administration of thiotepa rapidly reduced the number of haematopoietic cells causing significant dilatation of the sinusoids and atrophy of the trabecular bone 1 day after the injection. However, these changes were transient; regeneration of haematopoietic cells and normalization of the dilated sinusoids started 3 days after the injection, and the atrophied trabecular bone gradually returned to normal starting 6 days after the injection. These results imply that an extreme decrease in velocity and margination of sinusoidal blood flow following marked dilatation due to a decrease in haematopoietic cells cause atrophy of the trabecular bone, and that normalization of the sinusoidal blood flow following regeneration of haematopoietic cells leads to recovery from atrophy of trabecular bone.

Animals↗

PubMed1993

Follow-up study of anti-hepatitis C virus antibodies in blood donors implicated in post-transfusion non-A, non-B hepatitis.

We retrospectively examined the antibodies to p22, a hepatitis C virus (HCV) nucleocapsid protein, and to c100-3, a HCV nonstructural protein, in donors whose blood was transfused to patients who later developed post-transfusion non-A, non-B hepatitis. Of 13 such blood donors, three seroconverted and three seroreverted with the anti-c100-3 test. In contrast, 12 of the 13 blood donors showed the same results at transfusion and follow-up, and one donor showed seroconversion with the anti-p22 assay. The follow-up study shows that the anti-p22 antibody test provides consistent results and is far more suitable for screening blood than the anti-c100-3 test.

Antigens, Viral↗

PubMed1993

The inhibitory effect of SA3443, a novel cyclic disulfide compound, on alpha-naphthyl isothiocyanate-induced intrahepatic cholestasis in rats.

1. We investigated the effect of SA3443, a novel cyclic disulfide compound, on alpha-naphthyl isothiocyanate (ANIT)-induced intrahepatic cholestasis in rats. 2. SA3443 given orally at doses of 100 or 300 mg/kg, three times at 4h intervals, dose-dependently suppressed the elevation of serum total bilirubin, alkaline phosphatase activity and transaminase activities induced by administration of ANIT (80 mg/kg) 3h before the second dosages of SA3443. 3. SA3443 also significantly inhibited the reduction of bile flow in the ANIT-treated rats. 4. These findings indicated that SA3443 had a markedly inhibitory effect on ANIT-induced intrahepatic cholestasis in rats.

1-Naphthylisothiocyanate↗

PubMed1993

Interleukin-4 induces proliferation of adult T-cell leukemia cells.

To evaluate the effect of IL-4 on the growth of leukemic cells from adult T-cell leukemia (ATL) patients (ATL cells) and determine whether the IL-4 autocrine mechanism is involved in the growth of ATL cells, we studied the proliferative response of ATL cells, from 11 patients, cultured in the presence or absence of IL-4 in vitro. Leukemic cells from 10 of the 11 patients examined proliferated in response to both IL-2 and IL-4 in a dose-dependent manner. The proliferative response to IL-4 was higher than that obtained with IL-2 in 8 patients. The expression of the IL-2 receptor (IL-2R) alpha alpha-chain in leukemic cells from some patients was also enhanced by IL-4. The IL-4 receptor was demonstrated by flow cytometry on the surface of ATL cells. Neither IL-4-induced proliferation of ATL cells nor IL-4-induced IL-2R expression on ATL cells was inhibited by anti-Tac or anti-IL-2 antibody and, therefore, these effects of IL-4 are considered independent of endogenous IL-2 activity. However, IL-2 and IL-4 were undetectable in the culture supernatants of ATL cells from any patient by enzyme-linked immunosorbent assay. Interferon-gamma (IFN-gamma) partially inhibited IL-2 or IL-4-induced proliferation of ATL cells. These results suggest that leukemic cells from ATL patients proliferate by an IL-2 or IL-4 paracrine mechanism in lymphoid tissue in vivo and that IFN-gamma inhibits IL-2- or IL-4-induced proliferation of ATL cells.

Aged↗

PubMed1993

Transforming growth factor-beta 1 stimulates chondrogenesis and inhibits osteogenesis in high density culture of periosteum-derived cells.

Chick periosteum-derived mesenchymal cells have been reported to exhibit both osteogenic and chondrogenic potentials in high cell density culture conditions. Using this culture system, the effects of transforming growth factor-beta (TGF beta) on proliferation and differentiation of periosteal mesenchymal cells were studied. Supplementation with TGF beta 1 at doses of 0.3-1.0 ng/ml shortened the time course of chondrogenesis and increased the amount of cartilage formed in the lower part of the culture. On the other hand, the amount of bone formed in the upper part of the culture decreased with TGF beta treatment, whereas the time course of osteogenesis remained unaffected.

Animals↗

PubMed1993

[Interaction of trichloroethylene and isopropyl alcohol in the perfused rat liver].

The interaction of trichloroethylene (TCEL) and isopropyl alcohol (IPA) was studied in the perfused rat liver. Experiments consisted of four parts; TCEL administration with or without IPA, chloral hydrate (CH) administration with or without IPA, IPA administration with or without CH, IPA administration with or without trichloroethanol (TCE). The chemicals were administered into the perfusate of Krebs-Henseleit buffer saturated with 95%O2/5%CO2 in a non-recirculating circuit. Concentrations of the following three metabolites in the effluent were continuously measured by gas chromatograph and chemical methods: TCE and trichloroacetate (TCA) (metabolites of TCEL and CH), and acetone (a metabolite of IPA). Fluorescence from intracellular reduced pyridine nucleotides (NADH, NADPH) was monitored by surface fluorometry. The results showed that IPA changed the TCA/TCE ratio in the TCEL metabolism because of an increase in NADH production, and IPA oxidation was suppressed by CH because of an inhibitory effect of TCE on alcohol dehydrogenase. It was concluded that IPA and TCEL, both ubiquitous agents, interacted with each other in their metabolic pathways in the perfused rat liver, suggesting a new feature of a combined effect of these chemicals when they coexist.

1-Propanol↗

PubMed1993

Identification of cDNA clones coding for the style specific S11a-glycoprotein gene associated with gametophytic self-incompatibility in tomato (Lycopersicon peruvianum).

We isolated 18 cDNA candidates that were expected to encode parts of the self-incompatibility-associated RNase of Lycopersicon peruvianum PI 126441 (S11a-plant) from a style cDNA library. Polymerase chain reaction was used with oligonucleotides derived from conserved amino acid sequences of RNases from fungi and S-associated RNases in other species of Solanaceae. Two of these clones (both do not have full length sequences) gave 826-bp and 730-bp sequences, and they had the same open reading frame, named ORF-1. Comparison of the deduced amino acid sequence of ORF-1 with S-associated RNase of other Solanaceous plants showed a high degree of similarity. mRNA encoding this ORF-1 was about 1000 bases long and detected only in the style tissue by Northern analysis. Using one of the cDNA clones as a probe, we detected sequence variability among three different S-genotypes of randomly chosen wild-type tomatoes by Southern analysis. From these results, it was concluded that ORF-1 encodes the self-incompatibility associated S-glycoprotein of L. peruvianum PI 126441 (S11a-plant).

Amino Acid Sequence↗

PubMed1993

Angiotropic lymphoma of paranasal sinuses with initial symptoms of oculomotor nerve palsy.

A 78-year-old female was found to have angiotropic lymphoma, a rare fatal disease, with initial symptoms of oculomotor nerve palsy. A biopsy of the paranasal sinus mucosa showed that the small vessels were occupied by large mononuclear cells which upon immunohistochemical examination tested positive for pre B-cell markers. She felt a gradually increasing pain in her left thigh. Magnetic resonance imaging suggested the involvement of neoplastic cells in the left femoral bone marrow. Following chemotherapy treatment remission was achieved. Early diagnosis of angiotropic lymphoma appears very significant, as this disorder could be well controlled by systemic chemotherapy.

Aged↗

PubMed1993

The effect of prior transfusion history on blood donor anti-hepatitis C virus antibody.

In Japan, the major transfusion-associated disease is non-A, non-B hepatitis. We studied the relationship between transfusion history and blood donor antibodies to hepatitis C virus (HCV). The positive rate of antibodies to the HCV nonstructural protein (c100-3) depended on age and the time elapsed since transfusion. The anti-c100-3 ratio for subjects with transfusions made prior to 20 years ago was high. One quarter century ago, a change occurred in national blood policy from paid to non-paid voluntary donations. We also have studied the anti-HCV positive rate among donors with prior transfusion using a second generation HCV test kit which includes anti-HCV core antibody detection. The anti-HCV positive rate for the second generation test was higher than that for the anti-c100-3 test. Introduction of the second generation test is therefore more useful in screening than the anti-c100-3 test for blood programs.

Adolescent↗

PubMed1993

[Successful treatment by ranimustine (MCNU) of a patient with B-cell prolymphocytic leukemia (B-PLL)].

A 66-year-old female was admitted to our hospital because of leukocytosis, anemia and splenomegaly in August 1989. The white cell count was 3.49 x 10(10)/l with 88.5% of the leukemic cells which were morphologically similar to prolymphocytes. On flowcytometric analysis, the leukemic cells were found to be positive for B-cell markers such as CD19, CD20, FMC7, Sm-IgM and Sm-IgD and negative for CD5 and CD25. The chromosome analysis demonstrated hyperdiploidy of 48, XX, (+3, +18). She was diagnosed as having B-cell prolymphocytic leukemia, and treated with alpha-interferon and VP therapy with progression. Complete remission was achieved after three courses of ranimustine (MCNU) administration. She relapsed after about one year without therapy, but when MCNU was administered again, a secondary remission followed. The prolymphocytes during the relapse stage also had the phenotypes of CD11b, CD13 and CD25. This case is considered to be rare with respect to both complete remission by MCNU and the immunophenotypic change of leukemic cells during the relapse period.

Aged↗