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Biomedical subjects

M Morohashi

Publications and source records attributed to M Morohashi.

At least 91 records · Page 5Linked to original sources
PubMed1991

Cutaneous metastasis of renal cell carcinoma: an electron microscopic study.

A case of cutaneous metastasis of renal cell carcinoma in a 67-year-old man is described. Right side nephrectomy had been performed three years earlier, and a renal cell carcinoma was diagnosed. Following a bruise, the patient noticed an erythematous nodule on the scalp. Histological examination of this skin lesion showed atypical tumor cells consisting predominantly of clear cells with a honeycomb-like or adenoid structure. Electron microscopic examination revealed that the tumor cells were divided into three groups: clear cells with abundant glycogen, dark cells with abundant mitochondria, and intermediate cells containing both glycogen and mitochondria in varying proportions. Some of the tumor cells with an adenoid pattern had a brush border-like structure in the lumen. These results support the diagnosis of metastatic renal cell carcinoma. An electron microscopic approach may aid in diagnosis of cutaneous metastasis from renal cell carcinoma.

Aged↗
PubMed1990

Site-directed mutagenesis of Asp-376, the catalytic phosphorylation site, and Lys-507, the putative ATP-binding site, of the alpha-subunit of Torpedo californica Na+/K(+)-ATPase.

Point mutations of Asp-376 of the alpha-subunit of Torpedo californica Na+/K(+)-ATPase (the site of phosphorylation during the catalytic cycle) to Asn, Glu or Thr led to virtual abolishment of Na+/K(+)-ATPase activity and ouabain-binding capacity. Replacement of Lys-507 of the same subunit (the putative ATP-binding site) by Met resulted in decreases in Na+/K(+)-ATPase activity and ouabain-binding capacity. These results are in agreement with those reported for rabbit sarcoplasmic reticulum Ca2(+)-ATPase (Maruyama, K. and MacLennan, D.H. (1988) Proc. Natl. Acad. Sci. USA 85, 3314-3318).

Adenosine Triphosphate↗
PubMed1990

[The influence of coptidis rhizoma to lipase activity of Propionibacterium acnes].

Gas chromatography was applied for determination of the amounts of propionic and butyric acids in the medium produced by Propionibacterium acnes. The organism was incubated in Peptone-Yeast extract-Glucose medium containing 0.017 mEq/ml of tributyrin and various amounts of Coptidis Rhizoma at 37 degrees C for 24 to 96 hr. The amount of butyric acid produced by the lipase was reduced parallel with that of propionic acid resulted from the growth of P. acnes in the medium. These facts were also confirmed by counting the cell numbers of P. acnes. Furthermore, any lipase-negative colonies were not observed on the Kishishita's Lipase Medium. These findings indicate that Coptidis Rhizoma inhibits growth of P. acens and anti-lipase activity of the drug against the organism is resulted from the fact.

Drugs, Chinese Herbal↗
PubMed1988

Effects of Na+ and K+ on Artemia salina (Na,K)-ATPase solubilized with a zwitterionic detergent, CHAPS.

The membrane bound (Na,K)-ATPase prepared from Artemia salina nauplii was solubilized with a zwitterionic detergent, 3[3(cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), and then purified on a Bio-Gel A-1.5 m column in the presence of the detergent. 1) Upon solubilization, both NaCl and KCl protected the enzyme against loss of activity, KCl being more effective than NaCl. 2) Gel filtration of the solubilized enzyme on a Bio-Gel A-1.5 m column in the presence of 5 mM CHAPS resulted in loss of the enzyme activity even when one of the cations was added. Most of the phospholipids in the solubilized enzyme preparation were removed during the gel filtration (delipidation) and 10-25 phospholipids were left on a protomer (alpha beta) of the enzyme irrespective of the cation present during the gel filtration. With the addition of exogenous phospholipids, the activity was restored. The activity of the enzyme delipidated in the presence of KCl was restored to 3-4 times higher than in the case of that delipidated in the presence of NaCl. 3) Relipidation experiments with a fluorescent phospholipid, dansyl phosphatidylethanolamine (Dans-PE), suggested that the enzyme delipidated in the presence of KCl reassociated with phospholipids more firmly than the enzyme delipidated in the presence of NaCl. From these results we concluded that K+ stabilized the (Na,K)-ATPase more effectively than Na+, even when the enzyme was delipidated.

Animals↗
PubMed1987

Immunohistochemical study of Langerhans cells in skin tumors.

The behavior of Langerhans cells in skin tumors was investigated by immunohistochemical techniques using OKT6. OKT6-positive cells were numerous in squamous cell carcinomas, seborrheic keratoses and keratoacanthomas. They were rare in basal cell carcinomas, Bowen's disease, eccrine poromas, extramammary Paget's disease and warts. In solar keratosis, the number of OKT6-positive cells was almost equal or slightly larger compared to the normal epidermis. These results indicate that the density of Langerhans cells may not correlate with the degree of malignancy but, to a certain extent, with the nature of the membrane of tumor cells occurring e.g. during keratinization.

Antigens, Surface↗
PubMed1985

Protective effect of Na+ and K+ against inactivation of (Na+ + K+)-ATPase by high concentrations of 2-mercaptoethanol at high temperatures.

Purified dog kidney (Na+ + K+)-ATPase (EC 3.6.1.3) was inactivated with high concentrations of 2-mercaptoethanol at 50-55 degrees C. The inactivation was prevented by NaCl or KCl, with KCl being more effective than NaCl (the former ion being about one order more efficient under a typical set of experimental conditions). A disulfide bond in the beta-subunit of the enzyme protein was prevented from reductive cleavage by NaCl or KCl in accordance with protection of the enzyme activity. Choline chloride did not exert a significant protective effect over a similar concentration range. (Na+ + K+)-ATPase was also inactivated with high concentrations of 2-mercaptoethanol in the presence of low concentrations of dodecyl sulfate. This inactivation was also prevented by NaCl or KCl, with the latter being again more efficient than the former. These results indicate that Na+ and K+ bound to their respective ion-binding sites on the alpha-subunit exert a protective effect on a disulfide bond on the beta-subunit. This suggests some sort of interaction between the alpha- and the beta-subunits.

Animals↗
PubMed1985

The amino acid sequence of the fluorescein-labeled peptides of electric ray and brine shrimp (Na,K)-ATPase.

(Na,K)-ATPase from Torpedo californica (electric ray) and Artemia salina (brine shrimp) was labeled with fluorescein 5'-isothiocyanate (FITC) with concomitant loss of activity. Both inactivation and binding were inhibited in the presence of ATP. The sequence of the peptide resulting from tryptic digest containing labeled lysine from both enzymes is Tyr-Leu-Leu-Val-Met-Lys*-Gly-Ala-Pro-Glu-Arg. Thus the primary structure of this region is shown to be conserved in the enzymes of a nonvertebrate and a vertebrate.

Amino Acid Sequence↗
PubMed1984

Solubilization and purification of Artemia salina (Na,K)-activated ATPase and NH2-terminal amino acid sequence of its larger subunit.

Membrane bound (Na,K)-ATPase partially purified from the nauplius larva of the brine shrimp, Artemia salina, was solubilized with the non-ionic detergent C12E8 in the presence of KCl. The addition of KCl was essential for protecting the enzyme against inactivation. With solubilization the enzyme could then be purified to apparent homogeneity. Electron microscopic observation of the purified enzyme revealed a homogeneous population of particles with a diameter of approximately 4 nm. The larger (alpha) subunit of the enzyme formed double bands on sodium dodecyl sulfate-polyacrylamide gels. NH2-terminal sequence analysis of the alpha subunit revealed the possible presence of two isoforms of (Na,K)-ATPase. At the third position a small but distinct amount of lysine was found in addition to glycine, suggesting that the two forms are different from each other at least at the third residue. The NH2-terminal sequence determined is as follows. NH2-Ala-Lys-Gly (Lys)-Lys-Gln-Lys-Lys-Gly-Lys-Asp-Leu-Asn-Glu-Leu-Lys-Lys-Glu-Leu-Asp-Il e-Asp -Phe-His-Lys-Ile-Pro- The sequence is abundant in hydrophilic amino acids, especially lysine, and is quite different from those of vertebrate enzymes reported so far.

Amino Acid Sequence↗
PubMed1984

Proliferating trichilemmal cyst: an ultrastructural study.

A 73-year-old woman had a walnut-sized tumor in the occipital region for 10 years. The growth consisted of multiple small and large cystic epithelial masses. The cyst wall exhibited trichilemmal keratinization. Numerous squamous eddies as well as many glycogen-rich cells were present in the cyst wall. Some small round keratohyalin granules were observed in the cells below the horny layer. The desmosomes and masses of lipid droplets were seen in the horny layer. The findings described above are similar to those observed in the follicular isthmus and the follicular infundibulum. Other interesting findings include the presence of intranuclear inclusions of tonofilament-like material and/or keratohyalin-like granules within the cells near the mid-layer of the cyst wall.

Aged↗
PubMed1982

Immunofluorescence studies on C1Q in mast cells.

Evidence has been obtained of deposition of complement component C1q in mast cells, by the immunofluorscence technique, using biopsy specimens from the scalp from 5 of 7 normal subjects and 14 of 17 patients with alopecia areata and also from skin lesions of 1 of 2 patients with urticaria pigmentosa studied. The fluorescence in mast cells was of a granular pattern in most instances. No deposition of immunoglobulins (IgG, IgA, IgM, IgE) or other complement components (C3, C4, C5, C9) was demonstrable in the mast cells. The specificity of the C1q deposition in mast cells was confirmed by various tests, viz., the blocking test, prerinsing of tissue sections with bovine serum albumin-containing phosphate-buffered saline, absorption test of conjugates, C1q destruction test with urea or by heating, and the Ouchterlony method.

Adolescent↗