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Biomedical subjects

M Minami

Publications and source records attributed to M Minami.

At least 649 records · Page 36Linked to original sources
PubMed1982

[Changes in circadian rhythms of urinary catecholamine excretion in cold-stressed spontaneously hypertensive rats].

Investigations of the changes in ambulation and water drinking behavior of SHR were carried out and an attempt was made to determine the influence of cold exposure on the systolic blood pressure (SBP) and urinary catecholamines excretion (UCA) in SHR. Twenty week old male SHR-Okamoto strain (approximately 350 g) were used. The automatic Ambulo-Drinkometer was used to determine ambulatory activity and water drinking in SHR. UCA was determined by the trihydroxyindole method using high performance liquid chromatography. Cold exposure was performed for a period of 24 hours in a room maintained between 0--3 degrees C. It was observed that ambulatory activity and water drinking of SHR in dark phase were higher than those in the light phase (P less than 0.001). Significant increases in urinary norepinephrine (UNE), urinary epinephrine (UE), and urinary dopamine (UDA) contents as well as in urine volume were observed in the dark phase as compared with those in the light phase. SBP was significantly elevated after cold exposure. It was also demonstrated that cold exposure produced a significant increase in UNE and UE both in light and dark phases. Significant increase in UDA in cold stressed SHR was observed in dark phase. Although at room temperature (20 +/- 2 degrees C) significant difference in UCA between light and dark phases was observed, during cold exposure no significant difference was apparent. These findings suggest that temperature modulation induces changes in circadian rhythms of urinary CA excretion in SHR.

Animals↗
PubMed1981

Analysis of T cell hybridomas. II. Comparisons among three distinct types of monoclonal suppressor factors.

Five hybridoma T cell lines were prepared by fusion of Ts3 cells with the BW 5147 thymoma. The culture supernatants from these T cell hybrids contained a factor, TsF3, which specifically suppressed 4-hydroxy-3-nitrophenyl acetyl hapten (NP(-hapten cutaneous sensitivity responses. The properties of this new series of hybridoma factors was compared with those of two previously characterized types of NP-specific suppressor factors (TsF1 and TsF2). TsF3 activity was only observed if the factor was administered during the effector phases of the immune response. TsF3 bears I-J and C57BL anti-NP antibody idiotypic determinants and has binding specificity for the NP hapten. Furthermore, TsF3 does not suppress H-2 (I-J)-incompatible mice. In addition to this H-2 restriction, the monoclonal TsF3 factors also demonstrated an Igh genetic restriction. Finally, the TsF3 factors could be distinguished by their ability to suppress cyclophosphamide-treated recipients.

Animals↗
PubMed1981

Analysis of T cell hybridomas. I. Characterization of H-2 and Igh-restricted monoclonal suppressor factors.

Five hybridoma T cell lines were prepared by fusion of second order suppressor T cells (Ts2) with the BW5147 thymoma. The culture supernates from these T cell hybrids contained a factor, TsF2, which specifically suppressed 4-hydroxy-3-nitrophenyl acetyl hapten (NP)-induced cutaneous sensitivity responses. TsF2 activity was observed when the factor was administered during the effector phases of the immune response. TsF2 bears I-J determinants and has binding specificity for NPb idiotypic determinants. TsF2 suppressor activity could be absorbed on antigen-primed H-2-incompatible T cells but cannot suppress H-2-incompatible mice. In addition to this H-2 restriction, which maps to the I-J subregion, monoclonal TsF2 also has an Igh genetic restriction. The present results are combined with previous data to describe the cellular interactions leading to immune suppression.

Absorption↗
PubMed1981

Hapten-specific T cell responses to 4-hydroxy-3-nitrophenyl acetyl. XI. Pseudogenetic restrictions of hybridoma suppressor factors.

Suppressor factor derived from three different murine T cell hybridomas were characterized . They specifically inhibited 4-hydroxy-3-nitrophenyl acetyl cutaneous sensitivity responses. The factors bind antigen and bear I-J and idiotypic determinants, but lack conventional immunoglobulin constant-region determinants. The factors function during the induction phase of the immune response, by inducing a second population of suppressor cells (Ts(e)). Suppressor factor can inhibit both cellular and plaque-forming cell responses in appropriate strains of mice. These hybridoma suppressor factors directly suppress strains of mice that are Igh-V homologous with the strain producing the factor. Thus, there is an apparent Igh-V restriction in the activity of these factors. However, this is a pseudogenetic restriction because these factors generate second order suppressor cells (Ts(e)) in Igh-incompatible mice, but in order to express the suppressive activity, the cells must be adoptively transferred into recipients that are Igh compatible with the strain producing the suppressor factor. Finally, it was shown that the factor-induced Ts(e) population is under an apparent dual genetic restriction. Thus, Igh and H-2 homology is required in order for the Ts(e) population to express its suppressive activity.

Antibody Formation↗
PubMed1981

Effect of furosemide in congestive heart failure.

The diuretic effect of furosemide was studied in 18 patients with congestive heart failure. Subjects were divided into two groups, group I consisting of eight patients with moderate and group II of 10 patients with advanced congestive heart failure. Six hours after bolus injection of furosemide (40 mg), mean urinary sodium was 120.5 +/- 36.7 mEq in group I and 68.2 +/- 25.8 mEq in group II (p less than 0.01), mean urine volume was 1,100 +/- 281 and 764 +/- 257 ml (p less than 0.05), mean urinary furosemide excretion was 28.08 +/- 2.60 and 24.00 +/- 0.74 mg (p less than 0.05), and mean furosemide renal clearance was 73.4 +/- 16.6 and 42.3 +/- 11.5 ml/min (p less than 0.001). Diuretic effect and furosemide renal clearance, as well as urinary furosemide excretion, correlated positively. The diuretic effect of furosemide with and without hydralazine (0.2 mg/kg) was compared in eight patients in group II. Urinary sodium excretion 6 hr after furosemide rose from 77.2 +/- 31.0 to 122.8 +/- 42.5 mEq after furosemide with hydralazine (p less than 0.01). Urine volume rose from 854 +/- 278 to 1,279 +/- 359 ml (p less than 0.001), urinary furosemide excretion rose from 23.64 +/- 2.03 to 26.94 +/- 2.30 mg (p less than 0.01), and furosemide renal clearance rose from 46.3 +/- 12.2 to 62.5 +/- 18.6 ml/min (p less than 0.01).

Adult↗
PubMed1981

Functional association of idiotypic and I-J determinants on the antigen receptor of suppressor T cells.

The serological characteristics of the antigen receptor on 4-hydroxy-3-nitrophenylacetyl (NP) specific suppressor T cell hybridomas were analyzed. Three T-cell hybrids could be lysed with anti-idiotype and complement. The reactivity pattern observed from a panel of anti-idiotypic reagents indicated that NPb determinants were detected on all three hybrid lines. NP conjugates with bovine serum albumin or caproic acid specifically inhibited the complement-mediated lysis of these cells by both anti-NPb idiotype and anti-I-J antisera. These hapten conjugates failed to block lysis by anti-Thy 1 or anti-H-2K antisera on the same target cell populations. The data indicate that both I-J and Igh variable region gene products are intimately involved in the recognition of antigen by suppressor T cells. Finally, the suppressor cell hybrids produce soluble factors that mediate antigen-specific suppression. The characteristics of the cells and their factors indicate that the hybrids correspond to the Tsi or first-order suppressor cells in the suppressor cell pathway.

Animals↗
PubMed1981

Ia-positive stimulator cells are required in primary, but not in secondary, mixed leukocyte reactions against H-2K and H-2D differences.

The expression of I region gene products on stimulator cells in primary and secondary MLR directed against differences determined by the K or D regions of the H-2 gene complex was examined in B10-congenic mice. Treatment of the stimulator cells with anti-Ia antisera and complement (C) eliminates stimulation in primary MLR against K or D region gene products, indicating that the stimulator cells must express Ia antigens on their membranes. Further, stimulation in primary MLR against D region antigens is abolished by treatment of the stimulator cells with C and antisera against either I-A or I-E subregion products, but not by treatment of stimulator cells with C and antisera against I-J subregion products. Therefore, these stimulator cells express on their membranes both I-A and I-E subregion gene products, but not I-J subregion gene products. In contrast, in secondary MLR against K or D region gene products, treatment of stimulator cells with anti-Ia antisera and C does not abolish stimulation, indicating that Ia-negative cells can stimulate primed responder cells. These results indicate that the mechanisms of cell-cell recognition necessary in secondary MLR against K or D region gene products are different from those in primary MLR to the same products.

Animals↗
PubMed1981

[Studies on degradation of cartilage proteoglycan by rheumatoid synovial tissue. Part I: On the degraded products of proteoglycan (author's transl)].

The degradation of MgCl2-extracted proteoglycans (PG) from bovine nasal and articular cartilage was performed by using human rheumatoid synovial tissue extract, and the products were compared with that of being degraded by different commercially available proteases. 2. Degradation of PG by crude synovial extract occurred under the wide range of pH, and the degradation products showed the changes as follows; 1) a decrease of viscosity, 2) a decrease of hydrodynamic size, 3) an increase of electrophoretic mobility, 4) no change of the length of glycosaminoglycan side chains, 5) an increase of chondroitin sulfate relative to keratan sulfate in precipitate with 1% cetylpyridinium chloride (CPC), and 6) an increase of serine content in precipitate with 1% CPC. 3. The average hydrodynamic size of degradation products by crude synovial extract was larger than that of degradation products by pronase or papain. 4. The results indicate that the proteases play the main role on the PG-degrading activity of rheumatoid synovial tissue extract but the glycosidase play no significant role.

Adult↗
PubMed1981

[Studies on degradation of cartilage proteoglycan by rheumatoid synovial tissue. Part II: On the property of acid and neutral proteases obtained from rheumatoid synovial tissue (author's transl)].

1. Proteolytic enzymes are likely to play the main role on the proteoglycan (PG)-degrading activity of rheumatoid synovium. In this paper, the presence of cathepsin D, cathepsin B, lysosomal elastase and cathepsin G in rheumatoid synovium is established by isolation, purification, and characterization of these proteases. 2. The degradation of MgCl2-extracted PG from bovine nasal cartilage was performed by using these proteases and the property of the products was studied by the viscosity, Sepharose CL-4B chromatography, Agarose/polyacrylamide-gel electrophoresis, hexosamine analysis and amino acids analysis. 3. These proteases reduced the viscosity of PG solutions and the reaction was inhibited by addition of pepstatin, antipain, elastatinal and chymostatin for each protease. 4. The size and chemical composition of the degradation products varied with the different proteases. Of the four proteases, cathepsin G produced the largest glycosaminoglycan multi-chain peptides and cathepsin B produced the smallest contained chondroitin single-chain peptide. Each protease specifically split PG core protein and the degradation products particularly indicated the characteristic structure of core peptides. 5. The results suggest that these proteases may be contributed to the breakdown of cartilage PG in rheumatoid arthritis.

Amino Acids↗
PubMed1980

Characterization of the stimulator cells in the murine primary mixed leukocyte response.

Macrophage-enriched and depleted spleen cell populations were examined for their ability to stimulate a murine 1 degree mixed leukocyte response. A quantitative comparison of unfractionated spleen cells, Sephadex g-10 passed spleen cells, 4-hr glass adherent and 24-hr glass adherent spleen cells revealed that a potent 1 degree MLR stimulator cell was phagocytic and that T and B lymphocytes failed to stimulate a response. By using several inb;ed and recombinant mouse strains congenic for different subregions of the MHC, it was found that macrophage-enriched cells were capable of inducing an MLR against K, D, I-A, and I-E differences and against K and D mutants. Both macrophage-enriched and depleted spleen cells failed to stimulate responses when the stimulator and responder differed at I-J, I-C, S, or G. Moreover, MLR stimulation induced by K or D region differences alone was dependent upon stimulator cells that expressed Ia antigens. Therefore, it would appear that only a minor subpopulation of the cells that express the relevant MHC alloantigens is immunogenic in the murine 1 degree MLR.

Animals↗
PubMed1980

[Plasma catecholamine content in hypertensive subjects and spontaneously hypertensive rats using radioenzymatic assay (author's transl)].

The present experiments were undertaken to determine the plasma catecholamine content in normotensive, slightly hypertensive humans and spontaneously hypertensive rats using radioenzymatic assay. In addition, attempts were made to compare radioenzymatic assay with a fluorometric technique, using high performance liquid chromatography with respect to human plasma catecholamine content. Human plasma catecholamine content in normotensive subjects at rest was 250 +/- 61 pg/ml (mean +/- S.E.) for norepinephrine and 37 +/- 22 for epinephrine. Immediately after treadmill exercise, human plasma norepinephrine content significantly increased. In 14 patients with mild essential hypertension, plasma norepinephrine was 460 +2- 128 pg/ml with the subject in a supine position and 1030 +/- 151 in the case of treadmill exercise. Thus, there was a statistically significant difference. With regard to plasma catecholamine content in spontaneously hypertensive rats, the norepinephrine content was 816 pg/ml, epinephrine was 209 pg/ml and dopamine was 505 pg/ml, on an average. After comparing this method with the fluorometric technique using high performance liquid chromatography, we confirmed that the former requires much smaller sizes of samples and has much the same sensitivity as the latter.

Adult↗
PubMed1979

A simplified assay method of superoxide dismutase activity for clinical use.

A simple and inexpensive assay method of superoxide dismutase (SOD) activity of various biological materials has been developed. SOD activity can easily be measured by reading the medium's intense absorbance directly, and many samples can be treated in a short time using a reaction stopper which acts for a long time. Reproducibility of the assay method was excellent for the sample from an individual estimated at two different times (a week to a month) and the coefficient of variance was 5.1%. The mean and standard deviation of SOD activities of 45 blood samples from normal Japanese males 32.9 +/- 10.5 microgram per ml of blood; estimated using bovine SOD standard. The SOD activity of the fluid from lavaged lungs was 15.7 +/- 1.8 microgram/ml, and that of lung tissue homogenates from rats was 2.85 +/- 0.66 microgram/mg of protein.

Adult↗
PubMed1979

Successful replantation of an amputated leg in a child.

We report the successful replantation of an amputated leg in a 4-year-old boy. Four years after the replantation, skeletal growth and nerve regeneration were good and he had an excellent recovery of function and appearance. This result was undoubtedly enhanced by his youth, the ideal conditions for nerve repair, and the good preservation of the amputated leg in ice water. Replantation of an amputated lower extermity should be tried if the conditions mentioned above are fulfilled.

Amputation, Traumatic↗