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Biomedical subjects

S Nakashima

Publications and source records attributed to S Nakashima.

At least 289 records · Page 16Linked to original sources
PubMed1983

Coupling of polyphosphoinositide breakdown with calcium efflux in formyl-methionyl-leucyl-phenylalanine-stimulated rabbit neutrophils.

Exposure of rabbit neutrophils to formyl-methionyl-leucyl-phenylalanine (FMLP) induced the efflux of 45Ca2+ from pre-labeled cells which was almost complete within 30 s. On the other hand, FMLP-induced 45Ca2+ influx did not become apparent until 60 s after stimulation. When [3H]arachidonic acid-labeled neutrophils were stimulated with FMLP, the radioactivities in phosphatidylinositol 4,5-biphosphate (TPI) and phosphatidylinositol 4-phosphate (DPI) significantly decreased in parallel with the induction of 45Ca2+ efflux. In contrast, degradation of polyphosphoinositides in [3H]glycerol-labeled neutrophils was not significant until 60 s. Taken together, these results indicate that the early degradation of polyphosphoinositides, especially of those rich in arachidonic acid is closely associated with the initial efflux of calcium in FMLP-stimulated rabbit neutrophils. The study of resynthesis of polyphosphoinositides by measuring 32Pi incorporation into these lipids is also presented.

Animals↗
PubMed1983

Evidence for de novo synthesis of phosphatidylinositol coupled with histamine release in activated rat mast cells.

Phospholipid metabolisms in rat mast cells activated by ionophore A23187 and compound 48/80 were examined with reference to 'phosphatidylinositol (PI) cycle'. The addition of A23187 to [3H]glycerol-prelabeled mast cells induced a marked accumulation of the radioactivity in 1,2-diacylglycerol(DG) and phosphatidic acid(PA) within 10 to 30 sec. A great enhancement of [3H]glycerol incorporation into PA and PI was also detected during histamine release. On the other hand, 48/80 was far less effective than A23187 both in producing 1,2- DG and PA and in accerelating [3H]glycerol incorporation into PA and PI, despite the comparable ability of histamine release. The activity of Ca2+ uptake into mast cells, as measured by pulse-labeling with 45Ca2+, was increased when exposed to both of two agents. These data provide circumstantial evidence that phospholipid metabolisms, mainly de novo PI synthesis, may be a part of the triggering events for Ca2+ mobilization and secretory process. The PI metabolism induced by two different stimulants appears to behave in a different manner.

Animals↗
PubMed1983

The rapid polyphosphoinositide metabolism may be a triggering event for thrombin-mediated stimulation of human platelets.

The metabolism of polyphosphoinositides was examined in human platelets activated by thrombin. The addition of thrombin to [3H]glycerol-labeled platelets induced an initial loss and a subsequent increase of the radioactivity in phosphatidylinositol-4,5-bisphosphate (TPI) without any significant change in phosphatidylinositol-4-phosphate (DPI). A marked enhancement of [32P]Pi incorporation into TPI occurred in parallel with an increase in this lipid content, which was accompanied with a conccurent decrease in phosphatidylinositol (PI). The rate of this subsequent increase in TPI was smaller than that observed in [3H]arachidonic acid-labeled platelets, suggesting that formed TPI in activated platelets may contain much greater amount of arachidonate than preexisting TPI in resting platelets. These data indicate that thrombin causes a rapid change in TPI metabolism (initial degradation of preexisting TPI and subsequent production of arachidonate-rich TPI), which might be a primary candidate to modulate thrombin-induced function in human platelets.

Arachidonic Acid↗
PubMed1983

Isoelectric focusing of the inbred mouse antibody to bacterial alpha-amylase.

In the IgG antibody response to bacterial alpha-amylase (B alpha A) assayed by the enzymatic procedure, C3H/He (C3) mice were high and C57BL/6 (B6) mice were low responders. High responsiveness was inherited as a dominant characteristic in (B6XC3)F1 hybrid mice. In these strains, the primary antibody response was analyzed for heterogeneity by isoelectric focusing (IEF). The IEF spectra were visualized with the use of the capacity of antibody to inhibit the amylase activity of antigen. Increases in the antigen dose and in the time interval between immunization and bleeding resulted in increases in antibody titers accompanied by strong staining of focused antibodies and by the expansion of the pH range where antibodies were focused. High responsiveness in C3 and F1 hybrid mice was also associated with the increase in intensity of stain and the rapid expansion of pH range of focused antibodies. Another strain difference was noted in the isoelectric point (pI) values of antibodies taken early in the primary response. B6 antisera contained those fractions of antibodies focusing over a more alkaline area than C3 antibodies. A similar strain difference in the pI values of antibodies occurred in the response to an irrelevant antigen, Taka-amylase A (TAA), suggesting that the hypervariable regions of antibody molecules play no major part in the strain difference observed. Antisera from F1 hybrid mice displayed bands covering the combined pH ranges of B6 and C3 spectrotypes.

Animals↗
PubMed1983

Prevalence of diabetes mellitus in a rural area of Japan: by 75 g OGTT.

Tests for DM using the 75 g OGTT method (NDDG diagnostic criteria) were performed on 3145 persons living in rural areas of 8 different geographical regions of Japan (from Tohoku to Kyushu regions). Considerable regional difference was observed with western Japan tending to have higher DM and IGT rates than eastern Japan. The DM and IGT prevalence rates (for rural areas in Japan) were 3.9% and 6.9% respectively, and the DM detection rate was 2.8%. Comparison between normals and disturbance of glucose tolerance group (DM and IGT) on the basis of risk factors for atherosclerotic angiopathy showed that those with abnormal findings were definitely more numerous in the disturbance of glucose tolerance group.

Blood Glucose↗
PubMed1983

[Histopathological alteration of the central nervous system in rats, following long-term administration of manganese chloride--relation to the activity of the brain tyrosine hydroxylase].

Chronic manganese poisoning is characterized by mental and extrapyramidal disturbances. Parkinsonism-dementia complex (PD) on Guam is also manifested by progressive extrapyramidal syndrome and dementia. In PD, the reduced activities of catecholamine synthesizing enzymes in the brain has been demonstrated. On the other hand, the soil and water in Guam are rich in manganese, and one of the possible etiologic factors is trace element dysmetabolism in PD. The purpose of this paper is to clarify the effect of chronic manganese loading on the central nervous system. Manganese chloride (10 mg/ml of demineralized and distilled water) was administrated orally to Wistar female rats weighing 80-110 g. Six and 12 months after the administration, manganese loaded and control rats were sacrificed by perfusion for histological studies and by decapitation for the assay of tyrosine hydroxylase (TH) activity. The striatum, globus pallidus and substantia nigra were examined with electron microscopy. The brain for TH assay was dissected into four parts as the striatum, midbrain-thalamus, pons-medulla oblongata, and hypothalamus. Ultrastructural changes were overwhelmingly detected in the zona reticulata of the substantia nigra at 12 months. These changes were mainly composed of alterations of the postsynapse and neuronal soma--shrunken and electron dense dendrites accumulated degenerating materials and so-called simple atrophy of the neuron. Alterations in the presynapse were extremely milder than those in the postsynapse and neuron. At both 6 and 12 months, no significant changes in the striatum and globus pallidus were detected except for irregular windings of the plasma membrane in the axon terminal of the globus pallidus at 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[Immunohistochemistry on tyrosine hydroxylase in the substantia nigra of human autopsied cases].

Despite the numerous data on the distribution of catecholamine (CA) neurons in a wide variety of species, data on that of human are rare because of technical difficulty in applying fluorescent histochemical methods. On the other hand, immunohistochemistry on tyrosine hydroxylase (TH) which was essential for synthesis of CA, was assumed to be applicable to human autopsied brain. We performed indirect immunoperoxidase study on TH using 10% formalin or buffered formalin fixed, paraffin embedded sections of the substantia nigra from 40 autopsied cases, ranging in age 7 to 70 years. TH was purified from the bovine adrenal medulla using the procedure described by Oka et al. with some modification. Purified TH was injected with Freund's complete adjuvant into rabbits. The specificity of the antiserum was demonstrated by the inhibition study of CA relating enzymes, double immunodiffusion and immunoelectrophoresis against tissue homogenate of bovine adrenal medulla. TH immunoreactive (TH-IR) products were restricted to the neuronal soma, axons and dendrities in almost all of the case except for the "dead brain" cases. TH-IR neurons were of large polygonal or multipolar cells, and closely correspond to melanin-pigmented neurons, located in the compact zone and scattered in the reticular zone in the substantia nigra. On the other hand, melanin free neurons in the reticular and compact zone, were of medium or small bipolar cells and were not stained. It was of interest that the non TH-IR melanin-pigmented neurons firstly appeared in the substantia nigra at third decade and increased their number with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1981

Three polyethylene glycol dependent methods for the detection or circulating immune complexes in pathological sera: comparison with the Raji cell method.

A composite method using polyethylene glycol (PEG) and different markers for detecting circulating immune complexes (CIC) is described. The markers used are bovine conglutinin (RK-BA), C1q (C1q-BA) and IgG, IgM quantitation of PEG precipitate (RID-Ig). A composite scoring system is used in interpreting results from individual assays. The sensitivity of multiple PEG methods (MPM) was determined in 418 serum samples and compared with Raji cell assay in 204. Correlations between individual assays, viz., RK-BA-C1q-BA, RID-Ig and Raji cell test in several disease conditions including rheumatoid arthritis, glomerulonephritis, post-renal transplantation, maintenance haemodialysis, multiple sclerosis and normal pregnancies were computed. The relative discriminatory ability of a single PEG technique to differentiate normal from pathological sera in these disease states was observed in comparison with the composite PEG index. This index gives an improved assessment of abnormal sera, is simple and sensitive and has some advantages over biological techniques such as the Raji cell assay.U

Antigen-Antibody Complex↗
PubMed1980

In vitro examination of LH-HCG receptors in human corpora lutea of the menstrual cycle and pregnancy.

Binding of 125I-human chorionic gonadotropin (HCG) to homogenates of the human corpora lutea of the menstrual cycle and pregnancy was examined in vitro. While corpora lutea of the menstrual cycle bound 125I-HCG specifically, the corpora lutea of pregnancy from 8 weeks' gestation bound little or none of the added 125I-HCG. In the corpus luteum of the menstrual cycle the dissociation constant for HCG and the number of binding sites were analyzed by a Scatchard plot. However, from these observations along with the findings of earlier reports, it may be suggested that LH-HCG receptors remain reduced in number in the corpus luteum of pregnancy.

Chorionic Gonadotropin↗
PubMed1978

Studies on delayed hypersensitivity to protein antigen. Induction of delayed hypersensitivity by chemically modified antigen.

it was shown in our previous paper that mice primed with chemically modified bacterial alpha-amylase (BaA), which was neither cross-reactive with anti-BaA antibody nor able to induce a humoral anti-BaA response, developed enhanced responses to a subsequent challenge with native BaA and that the magnitude of the immunological memory was closely related to the priming dose of modified BaA. This paper describes the experimental conditions for induction of delayed hypersensitivity (DH) by modified BaA in relation to the development of immunological memory for antibody response to native BaA. Mice primed with either an intraperitoneal (i.p.) or subcutaneous (s.c.) injection of modified BaA in complete Freunds adjuvant (CFA) developed enhanced anti-BaA as the immunogen and modified BaA as the eliciting antigen, the relationship of anti-BaA responses to a subsequent challenge with BaA. In contrast, when mice were immunized with an s.c. injection of the modified BaA only, a significant level of DH to native BaA could be induced, as measured by the footpad reaction (FPR). The highest degree of DH was observed in mice given 50 micrograms of modified BaA. DH was detectable within 5 days and persisted for 25 days after immunization. In the reciprocal combination of native BaA as the immunogen and modified BaA as the eliciting antigen, the relationship of anti-BaA responses to DH was examined. The primary anti-BaA responses induced by an i.p. injection of large doses of BaA was markedly higher than those induced by an s.c. injection, while DH was exhibited only in mice given s.c. injection of BaA in CFA. With respect to DH to native BaA induced by the modified BaA, it was shown that C3H/He mice were high and C57BL/6 mice were low responders.

Amylases↗