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Biomedical subjects

T Gomi

Publications and source records attributed to T Gomi.

At least 127 records · Page 7Linked to original sources
PubMed1984

Purification of messenger RNA coding for glycine methyltransferase from rat liver.

Rat liver messenger RNA coding for glycine methyltransferase was associated preferentially with free polysomes. The mRNA was purified about 1000-fold over the total poly(A)-containing RNA by specific immunoadsorption of polysomes to protein A-Sepharose followed by oligo(dT)-cellulose column chromatography. Sodium dodecyl sulfate-gel electrophoresis of the in vitro translation products in a rabbit reticulocyte lysate system revealed only one major band which migrated to the position of the purified glycine methyltransferase subunit. The result shows that the mRNA isolated is nearly homogeneous and suggests that no precursor form of the enzyme existed. The mRNA sedimented at the position slightly smaller than 18 S rRNA in a sucrose density-gradient centrifugation and was shown to contain about 1,300 nucleotides by the Northern blot hybridization analysis with a cDNA probe.

Animals↗
PubMed1983

Evidence for an essential histidine residue in S-adenosylhomocysteinase from rat liver.

Rat liver S-adenosylhomocysteinase (EC 3.3.1.1) is inactivated by diethyl pyrocarbonate. The inactivation is first order in enzyme and in reagent, and a second-order rate constant of 77 M-1 min-1 is obtained at pH 6.9 and 0 degree C. The rate of inactivation is dependent on pH, and the pH-inactivation rate data show the involvement of a group with a pK of 6.8. The difference spectrum of the inactivated and native enzymes shows a single peak at 242 nm, indicating the modification of histidine residues. No trough at around 280 nm due to O-carbethoxytyrosine is observed. The sulfhydryl content of the enzyme is unchanged by the reaction. The inactivation was reversed by hydroxylamine. Although the reaction with [3H]diethyl pyrocarbonate reveals that a residue(s) other than histidine is (are) also modified, the agreement of the number of histidine residues modified and the number of carbethoxy groups removed by hydroxylamine treatment indicates that the inactivation is solely due to the modification of histidine. Statistical analysis of the residual enzyme activity and the extent of modification shows that, among six modifiable residues per subunit, one which reacts more rapidly with the reagent than the rest is critical for activity. The modified enzyme still retains the capacity to bind adenosine and S-adenosylhomocysteine and to oxidize the 3'-hydroxyl of these compounds as evidenced by the reduction of the enzyme-bound NAD+. Slow but significant exchange of the 4' proton with solvent also occurs with the modified enzyme. Thus, it may be concluded that the histidine residue essential for activity is involved in a catalytic reaction other than the abstraction of 3'-hydroxyl and 4' protons of the substrates.

Adenosine↗
PubMed1983

Hemolytic-uremic syndrome in an adult.

This report describes a 45-year-old man who suffered from hemolytic-uremic syndrome. In his autopsy findings, kidney arteriolar walls showed marked hyaline degeneration and interlobular arteries were occluded by severe intimal proliferation. No vascular changes were found in other organs. There were no arteriosclerotic changes in either main branches from the aorta or the aorta. These vascular changes are correspond well with the early features of malignant nephrosclerosis without any clinical findings of malignant hypertension. This type is called primary malignant nephrosclerosis by Bohle et al. We would like to point out the significance of this case in the re-consideration of the pathogenesis of malignant nephrosclerosis.

Hemolytic-Uremic Syndrome↗
PubMed1982

A novel nuclear protein in rat ventral prostate. Androgen-dependent and age-related change.

A novel protein was found in the nuclei of rat ventral prostate. This protein has a molecular weight of about 21 kDa as measured by SDS-polyacrylamide gel electrophoresis. It showed a characteristic change between 3 and 84 weeks after birth in close association with the level of testosterone in the blood. After castration, the level of the 21-kDa protein decreased to 1/60 of normal in 7 days, but on daily injection of testosterone the level was restored to normal in 8 days and to twice the normal level in 14 days. Unlike H1 and H1(0) histone and high mobility group proteins, the 21-kDa protein was not extracted with 5% HClO4, but was partially extracted with 0.35 M NaCl. The 21-kDa protein was not found in kidney, liver, or bain, suggesting that it is specific to the ventral prostate.

Aging↗
PubMed1982

Inactivation of rat liver S-adenosylhomocysteinase by iodoacetamide.

S-Adenosylhomocysteine (EC 3.3.1.1) from rat liver is inactivated by iodoacetamide following pseudo-first-order reaction kinetics. The apparent first-order rate constant for inactivation is proportional to the concentration of the modifier, and a value of 7.55 M-1 min-1 is obtained for the second-order rate constant at pH 9.06 and 25 degrees C. Amino acid analysis of the modifier enzyme shows the formation of S-(carboxymethyl)cysteine. No peaks corresponding to N epsilon-(carboxymethyl)- and N epsilon,N epsilon-bis(carboxymethyl)lysines, N-(carboxymethyl)histidines, S-(carboxymethyl)homocysteine, homoserine, and homoserine lactone are detected. Glycolic acid is also not found in the acid hydrolysate of the modified enzyme, indicating the absence of modification at carboxyl residues. These results and the finding that the number of residues modified as determined by the incorporation of iodo[1-14C]acetamide is equal to the number of cysteine residues lost by modification establish the site of modification as cysteine residues. Kinetics of inactivation and incorporation of the label from iodo[1-14C]acetamide show that two among three modifiable residues per enzyme subunit are essential for activity and the modification of either results in complete inactivation. The inactivation by iodoacetamide does not involve alteration in the molecular size of enzyme nor release of the bound NAD+. The modified enzyme still retains the capacity to bind adenosine and to oxidize it as evidenced by the reduction of enzyme-bound NAD+ but does not catalyze the exchange of the 4' proton with solvent. Thus, it is suggested that the inability of the modified enzyme to catalyze the overall reaction is due to the failure to abstract the 4' proton in the catalytic cycle.

Adenine↗
PubMed1981

Androgen receptor in human placental villi.

In studies with a synthetic androgen, R 1881, an androgen-binding component was found in the cytosol of human placental villi. Kinetic analysis indicated that the Kd value of this component was 1.4 nM at 0-4 degrees C and that binding of R 1881 amounted to 277 +/- 73 fmol/mg protein. glycerol density gradient ultracentrifugation showed a peak of binding activity in the 8S region in a medium of low ionic strength, but in the 4.5S region in a medium containing 9.5 M KCl. The R 1881-binding component was inactivated by mild heat- or trypsin-treatment, but not by treatment with DNase or RNase. Most of the R 1881-binding activity was sedimented at 20 to 40% saturation of ammonium sulfate. These findings indicate that the R 1881-binding component in human placental cytosol is quite similar in its characteristics to androgen receptors, which are present in various androgen-responsive organs. Testosterone was a more potent competitor of R 1881-binding than DHT or cyproterone acetate. Scatchard plots indicated that the binding site of testosterone was identical with that of R 1881. These findings suggest that the androgen receptor in placental cytosol is specific for testosterone. The Kd value for testosterone was calculated to be 3.2 nM.

Cell Membrane↗
PubMed1978

Renovascular hypertension due to Buerger's disease.

In a 42-year-old man with severe hypertension, stenosis of the left renal artery at its origin and occlusion of the abdominal aorta below the level of the renal arteries were observed. His past history and clinical and laboratory findings suggested that the renal artery stenosis was due to Buerger's disease which was reported to be a rare cause of renovascular hypertension.

Adult↗
PubMed1977

Observations on benign gastric ulcer simulating gastric carcinoma.

We have re-evaluated over-diagnosed cases which were first diagnosed, pre-operatively, as gastric cancer yet later confirmed as benign lesion (excavated lesion, in particular) in the post-operative histological examination of resected stomachs. We have experienced a total number of 1,358 cases which, being detected through mass survey, were diagnosed as cancer and, consequently, operated upon. On the other hand, 61 benign cases were misdiagnosed as cancer, 28 cases being protruded lesions and 33 cases excavated lesions. Among the misdiagnosed cases of excavated lesions, 27 cases were gastric ulcers or their scars, the remaining 6 cases being gastritis or gastric erosion. In 22 out of 33 cases of misdiagnosis, the wrong diagnosis was made by relying solely upon X-ray and endoscopy. Even after the addition of cytology, there were still 9 cases of misdiagnosis. Since, however, biopsy was introduced, there have been only 2 cases of wrong diagnosis. We may safely say that through these findings the absolute necessity of biopsy for the attainment of an accurate diagnosis of early gastric cancer has been sufficiently attested.

Biopsy↗
PubMed1977

Barium enema examination using a remote controlled positive and negative contrast media inflator.

In a series of 30 patients, barium enema examination of the colon was performed via a remote controlled air and contrast media inflator. With this apparatus, introduction and elimination of air and barium into the colon can be accomplished at a freely adjustable rate of injection by remote control. Fluoroscopy time is significantly reduced and the operator is not exposed to radiation.

Adult↗
PubMed1976

Evaluation of mass screening program for stomach cancer.

Particular method and program of mass survey examination of gastric cancer were introduced into Miyagi Prefecture and the results accumulated during the past 14 years are presented. During this period, 1,427 cases of gastric cancer (0.18%), as well as many cases of other diseases of the stomach and duodenum, were found by the mass survey. 450 cases were those of early cancer in which invasion of carcinoma was limited to the mucosa and submucosa. The ratio of surgically confirmed early cancer cases to all the stomach cancer cases was 36.4%. Almost in all cases of early stomach cancer there were neither complaints nor clinical symptoms; that is, they were the cases of so-called preclinical cancer of the stomach. The prognosis after surgery of early stomach cancer was remarkably favorable with a five-year survival rate over 90% and the death rate due to stomach cancer was actually decreased in the surveyed population.

Adult↗
PubMed1976

Crohn's disease, non-specific ulcers of the small intestine, and idiopathic proctocolitis in a Japanese university hospital from 1954 to 1974.

Most of the cases of Crohn's disease reported in Japan were originally treated surgically as acute appendicitis and, after appendectomy, they were diagnosed as acute terminal ileitis or acute Crohn's disease, which should belong to a category different from typical Crohn's disease, according to the international nomenclature by the Council for International Organization of Medical Sciences in 1973. Reviewing our university hospital records from 1954 to 1974, the incidence of typical Crohn's disease and idiopathic proctocolitis has been increasing, while the patients with intestinal tuberculosis have been decreasing. Clinical and histopathological features of operated three groups of our patients with Crohn's disease of the small intestine, non-specific ulcers of the small intestine and prestomal ileitis were comparatively studied. Furthermore, 9 cases of operated Crohn's disease of the colon and 23 cases of operated idiopathic proctocolitis were similarly evaluated. The importance of diagnosing Crohn's disease as a whole from both clinical and histopathological stand points of view was emphasized, and main differential diagnostic criteria between Crohn's disease and idiopathic proctocolitis were discussed.

Colitis, Ulcerative↗