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Biomedical subjects

M Kawashima

Publications and source records attributed to M Kawashima.

At least 289 records · Page 16Linked to original sources
PubMed1987

A common myosin light chain is expressed in chicken embryonic skeletal, cardiac, and smooth muscles and in brain continuously from embryo to adult.

We have isolated cDNA clones of the mRNA for chick embryonic myosin light chain (MLC), L23, by cross-hybridization with chicken skeletal muscle MLC1 cDNA. The identification of the isolated cDNAs was carried out by in vitro translation of hybrid-selected mRNA. Sequence analysis of the cloned cDNAs revealed that the cDNA insert contained 832 nucleotides and predicted a polypeptide of 185 amino acids with a calculated molecular weight of 20,687. The deduced amino acid sequence for L23 showed high sequence similarities to those of adult alkali type MLCs from various tissues, indicating that L23 belongs to the alkali MLC group. Using the cloned cDNA as a hybridization probe, we have revealed by RNA blot analysis that the expression of L23 mRNA was regulated in temporal and tissue-specific manners. The L23 mRNA of 1.1 kilobases is transiently expressed in embryonic skeletal, cardiac, and smooth muscles of chickens. It is also found in the brain of chickens during all stages of development so far investigated. Only a single gene for L23 was detected by Southern blot of chick genomic DNA. We therefore suggest that L23 is expressed from a single gene in both embryonic muscles and brain.

Age Factors↗
PubMed1987

Pathogenesis of arteritis of SL/Ni mice. Possible lytic effect of anti-gp70 antibodies on vascular smooth muscle cells.

The SL/Ni strain of mice spontaneously develops a necrotizing polyarteritis (NPA) that is histologically quite similar to human polyarteritis nodosa. This NPA most frequently affected parametrial tissues and/or ovaries of females and small arterioles of the major salivary glands. Electron microscopic studies of early arterial lesions revealed massive budding of C-type particles from arterial smooth muscle cells just before or at the onset of arteritis. In addition, binding of mouse IgG and C3 to the plasma membrane of virus-producing smooth muscle cells was shown by immunoelectron microscopy. Antibody-bound muscle cells showed disintegration of their plasma membrane, but degeneration and necrosis of muscle cells were not associated with dense infiltration of neutrophils. SL/Ni mice had natural antibodies that bound specifically to a fibroblast cell line infected with an endogenous ecotropic murine leukemia virus (MuLV) recovered from a SL/Ni mouse. Most of the natural antibodies were cytotoxic in the presence of murine complement. Western blot immunoassays revealed that among 14 SL/Ni female mice tested, all of the 9 mice that were affected by arteritis had anti-gp70 antibodies, while the 3 anti-gp70- mice were not affected. The presence of anti-p30 or anti-p15 (anti-p12) antibodies, which were also detected in some SL/Ni mice, did not correlate with the development of arteritis. These results strongly support the hypothesis that NPA in SL/Ni mice is mediated by the lysis of arterial smooth muscle cells due to the deposition of cytotoxic natural antibodies directed to cell membrane-bound gp70 molecules of an endogenous ecotropic MuLV.

Animals↗
PubMed1987

Presence of estrogen receptors in the hen hypothalamus and pituitary.

In the hen, the preoptic area, medial basal hypothalamus, and anterior lobe of the pituitary showed a greater uptake of [3H]estradiol-17 beta (E2) in vivo than other tissues. This uptake was decreased when unlabeled diethylstilbestrol was injected together with the [3H]E2 or when unlabeled E2 was injected before the [3H]E2 injection. A specific estrogen binding component having properties of a receptor was found in vitro in both soluble and insoluble fractions of these tissues in a hypotonic buffer solution. The administration of E2 in vivo caused a marked decrease in the estrogen receptor binding in the soluble fraction with a concomitant increase in binding in the insoluble fraction; as a result, total binding (sum of the bindings in soluble and insoluble fraction) did not change.

Animals↗
PubMed1987

Decrease of free thyroxin in serum of lactating women.

We measured thyroid hormones and thyroxin-binding proteins in serum from 62 normal lactating and 52 nonlactating women at three months postpartum, and compared these values with those for 42 nonpregnant control women of similar age. Mean thyroxin concentrations in the lactating and nonlactating women were significantly (P less than 0.001) lower than that of the nonpregnant controls, but there was no significant difference (P greater than 0.2) in triiodothyronine concentration among these three groups. Free T4 concentration was significantly (P less than 0.01) lower in lactating women than in controls. The reverse-T3 concentrations in both lactating and nonlactating women were significantly (P less than 0.001) lower than in controls, and were significantly (P less than 0.001) lower in lactating than in nonlactating women. The concentration of thyroxin-binding globulin was significantly higher in lactating women than in controls, and the albumin concentration was significantly lower in women postpartum than in controls. Evidently, regulation of thyroid hormone in women postpartum, especially during lactation, differs from that in nonpregnant women.

Adult↗
PubMed1987

Immunopathology of murine lupus-overview, SL/Ni and MRL/Mp-lpr/lpr-.

Murine lupus is a useful animal model for the study of disease based on some defect in the immune system including the so-called collagen diseases. Seven strains are available in Japan; NZB, NZB/WF1, MRL/Mp-lpr/lpr, BxSB, SL/Ni, NC and C3H/HeJ-gld/gld. Characteristics of these strains of mice are outlined. Care should be taken about applying the knowledge or information obtained from animal models to the analysis of related human disease because there are various genetic or species barriers which cannot be overcome. Therefore, it is rather dangerous to conclude that the pathogenesis of some human disease is similar to that of an animal model from a study of the latter. Therefore, one should divide the data obtained from animal experiments into "factors" and insert each factor in the "formula" of a human disease in order to better understand it. Recent studies by the authors on two strains of lupus mouse; SL/Ni and MRL/Mp-lpr/lpr from such a standpoint are presented and discussed in detail.

Animals↗
PubMed1986

Characterization of a new type of human papillomavirus (HPV) related to HPV5 from a case of actinic keratosis.

Human papillomavirus (HPV) DNA sequences, related to the genomes of HPVs associated with epidermodysplasia verruciformis (EV), were detected in DNA samples extracted from biopsied lesions in 2 of 24 cases of actinic keratosis found in the general population. An HPV DNA was molecularly cloned from one of these samples. Blot hybridization experiments, performed under stringent conditions, revealed a significant cross-hybridization only between this HPV DNA and the DNAs of HPV5 and of the HPV5-related types. The extent of homology between them ranged from 7 to 30%, as evaluated by hybridization in liquid phase at saturation followed by nuclease S1 analysis. This showed that the cloned HPV represented a new type, tentatively named HPV36. HPV36 was not found in the other 22 cases of actinic keratosis, but was detected in scrapings of benign lesions of 7 of 18 (39%) EV patients.

Aged↗
PubMed1986

Effect of serotonin and beta-endorphin on the release of luteinizing hormone in the hen (Gallus domesticus).

Serotonin (5-hydroxytryptamine) and beta-endorphin administered into the third ventricle of the hen blocked normal and progesterone-induced ovulation, and suppressed the release of LH in normal and progesterone-injected hens. p-Chlorophenylalanine, an inhibitor of serotonin synthesis, caused the release of LH and diminished the effect of beta-endorphin. Naloxone, an antagonist of opiate peptides, diminished the effect of beta-endorphin but not the effect of serotonin. The results suggest that both serotonin and beta-endorphin are involved in the control of LH release in the hen as an inhibitory agent, and serotonin is predominant while beta-endorphin is subsidiary to the inhibition of the LH release.

Animals↗
PubMed1986

Epidermolysis bullosa acquisita: clinical response to plasma exchange therapy and circulating anti-basement membrane zone antibody titer.

Epidermolysis bullosa acquisita has been recognized as a rare autoimmune mechanobullous disorder since the detection of immunoglobulin and complement deposits along the basement membrane zone. A circulating anti-basement membrane zone antibody has also been detected in some cases. We are reporting a case of epidermolysis bullosa acquisita in which clinical symptoms were well correlated with the circulating anti-basement membrane zone antibody titers. Although the patient initially responded very well to corticosteroid therapy, remission could not be maintained without increasing the dosage. Other therapies, including azathioprine, dapsone, vitamin E, and gold sodium thiomalate, produced no beneficial effects. Although a high dose of oral corticosteroid and cyclophosphamide decreased the antibody titer and blister formation, this therapy had to be terminated because of side effects. Plasma exchange therapy in combination with corticosteroid and low-dose cyclophosphamide resulted in a marked decrease of the anti-basement membrane zone antibody titer and clinical improvement. Thus plasma exchange therapy may be a useful adjunct to conventional treatments for patients with epidermolysis bullosa acquisita.

Autoantibodies↗