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Biomedical subjects

M Koga

Publications and source records attributed to M Koga.

At least 451 records · Page 25Linked to original sources
PubMed1983

Changes with aging in serum lipoproteins and apolipoprotein C subclasses.

The effects of aging on serum lipids, lipoproteins and apolipoprotein C subclasses in very low density lipoprotein (VLDL) were investigated in healthy male subjects aged from the 1st to the 9th decade. The serum cholesterol, phospholipid and triglyceride concentrations, the serum beta-lipoprotein concentration determined immunologically, and the beta-lipoprotein percentage determined by electrophoresis showed the lowest levels in the 2nd decade, increased gradually with age, attained the highest level in the 6th to 7th decade and slightly declined in the 9th decade. The VLDL-low density lipoprotein (LDL) cholesterol level changed almost in parallel with the serum total cholesterol level, but the HDL cholesterol level and the apolipoprotein A concentration remained almost constant showing no age-related change. The free cholesterol percentages in every lipoprotein fraction and the apolipoprotein content in LDL were higher in the subjects in the 6th and 7th decade than those in the 2nd to 3rd decade. The apo C II/C III ratio in VLDL increased with age. These data suggest that the ability to active lipoprotein lipase may not be impaired but the lecithin:cholesterol acyltransferase (LCAT) activity declines with age.

Adolescent↗
PubMed1983

Neurovirulence of murine coronavirus JHM temperature-sensitive mutants in rats.

The murine coronavirus strain JHM is highly neurotropic in rats and has a marked tendency to cause demyelinating central nervous system diseases after intracerebral inoculation. The clinical diseases observed range from an acute encephalomyelitis occurring within 2 weeks postinfection to a subacute demyelinating encephalomyelitis developing several weeks or months postinfection. Uncloned wild-type virus induced both acute and subacute diseases, whereas cloned JHM virus grown in tissue culture caused only acute disease without the pronounced lesions of primary demyelination. In contrast, temperature-sensitive mutants selected from that clone were capable of inducing subacute demyelinating encephalomyelitis after prolonged incubation times. Viruses recovered from diseased animals were still temperature sensitive. Inoculation of temperature-sensitive mutants into suckling rats (age, 10 to 15 days) produced high rates of subacute demyelinating diseases running a more chronic course; these diseases often were not fatal. Those rats which did not show clinical signs frequently revealed inflammatory demyelinating lesions. These findings indicate that the rate and type of clinical disease are dependent on the neurovirulence of the virus mutant used for inoculation and the age of the animals at the time of infection.

Aging↗
PubMed1983

Aneurysm of the left aortic sinus causing acute myocardial infarction.

A 30-year-old female had an acute myocardial infarction complicated by congestive heart failure. Angiography demonstrated an aneurysm in the area of the left aortic sinus. The aneurysm compressed and displaced the main trunk of the left coronary artery and the proximal portion of the left anterior descending artery. This aneurysm was considered to be the cause of the infarction. Aortic valve replacement and removal of the aneurysm were performed. Postoperative studies revealed good function of the replaced valve, good antegrade filling of the left coronary artery, and improved left ventricular function.

Adult↗
PubMed1983

Human infection with the pancreas fluke, Eurytrema pancreaticum.

A 70-year-old Japanese woman with gastric cancer in Fukuoka Prefecture, Japan, was found at autopsy to have about 15 adult flukes, Eurytrema pancreaticum, in the dilated pancreatic ducts. The number of eosinophils in the blood was within normal limits. The two worms which were least damaged when removed from the gland were used for stained specimens, and another two were macerated to collect the eggs. The parasites (10 X 5, 11 X 7 mm in size) were broad, flattened, oval to fusiform. The suckers were large, the oral (2.1 X 2.0, 2.0 X 1.9 mm) being larger than the ventral (1.6 X 1.6, 1.4 X 1.5 mm). The eggs (47.06 +/- 3.88 X 30.35 +/- 2.74 microns) were embryonated in the uterus. These findings led to the identification of E. pancreaticum. This is the second documented case of eurytremiasis in man.

Aged↗
PubMed1983

Growth of normal and neoplastic mouse mammary epithelial cells in primary culture: stimulation by conditioned medium from mouse mammary fibroblasts.

Conditioned medium obtained from mouse mammary fibroblasts markedly stimulated both DNA synthesis and cell proliferation in primary monolayer cultures of mouse mammary tumor cells. Growth of normal mammary epithelial cells from virgin female mice was likewise stimulated by the conditioned medium. The growth-stimulating activity was absent in conditioned media from 3T3 cells, 3T6 cells, mouse embryonic and lung fibroblasts, mammary tumor cells and normal mammary epithelial cells. Stimulation of DNA synthesis in mammary tumor cells was also observed with epidermal growth factor (EGF), although the effect was less than that observed with the conditioned medium. Receptor studies using 125I-labeled EGF further showed that the specific binding of EGF to mammary tumor cells was not inhibited by the conditioned medium. The molecular weight of the growth-stimulating activity in mammary fibroblast-conditioned medium was estimated to be approximately 100,000 daltons by Sephadex G-200 column chromatography. These observations suggest that mammary fibroblasts, which constitute the stroma of the mammary gland, produce a mammary epithelial cell growth factor(s) distinct from EGF.

Animals↗
PubMed1983

[Case of lipohyperplasia of the ileocecal valve with adenocarcinoma of the ascending colon].

A rare case of lipohyperplasia of the ileocecal valve contiguous with adenocarcinoma of the ascending colon is reported. The patient was a 67-year-old female with a chief complaint of muco-bloody stool. Barium enema X-ray study revealed a filling defect in the proximal portion of the ascending colon, suggestive of Borrmann II-type carcinoma and enlargement of the ileocecal valve. Ileocecotomy and right colectomy were performed. Histological examination disclosed that the tumor of the ascending colon consisted of well differentiated adenocarcinoma; the proliferation of fat tissue in the submucosa of the ileocecal valve was diagnosed as lipohyperplasia of the ileocecal valve. The histogenesis of this lipohyperplasia seems to be secondary development induced by the adenocarcinoma of the ascending colon.

Adenocarcinoma↗
PubMed1983

[Clinical studies on cefadroxil in the field of pediatrics].

The newly developed cefadroxil (CDX) dry syrup in a mean daily dose of 32.9 mg/kg t.i.d. or q.i.d. was administered to children for a period of 8 days on the average; viz. a total of 64 cases consisting of 39 cases of tonsillitis, 2 of tonsillitis complicated with otitis media, 1 of bronchitis, 1 of pneumonia, 14 of scarlet fever, and 7 of urinary tract infections; and its clinical and bacteriological effects, and adverse reactions were examined, leading to the following results. 1. The clinical effects were "good" or "excellent" in any of 39 cases of tonsillitis, 2 of tonsillitis complicated with otitis media, 1 of pneumonia, 14 of scarlet fever, and 7 of urinary tract infections, and "fair" only in a case of bronchitis, showing the high efficacy of 98.4%. 2. The clinical effects by daily dose were compared only in the great cases of tonsillitis between the 2 daily dose groups of 30 mg/kg or below and 31 to 40 mg/kg, and both groups showed "good" or "excellent" results, but the latter group revealed that the excellent rate was greater by 20.8% than that of the former group. 3. The frequency of daily administration was 3 times or 4 times and the cases of 4 times administration were few in any disease. In comparison of clinical effects between the 3 times group and the 4 times group in the whole cases, no significant difference was observed between both groups but it is desirable to make the 4 times administration in view of the pharmacokinetics. 4. The bacteriological effects could be judged in 15 cases, namely bacteria were eradicated in 14 cases and unchanged in 1 case, showing a good result of the eradication rate as 93.3%. 5. No adverse reaction was observed and the laboratory test values showed eosinophilia in 7 cases (15.9%) and abnormal elevations of GPT in 1 case (4.5%), of GOT and GPT in 2 case (9.1%), of LDH in 1 case (4.8%) and of BUN in 1 case (4.8%), but 4 of the 7 cases with eosinophilia seemed attributable to underlying diseases or objective diseases. From the above it can be said that this preparation is a useful drug in mild bacterial diseases.

Adolescent↗
PubMed1982

Age-related changes in cholesterol and bile-acid metabolism in spontaneously hypertensive rats.

Age-related changes in serum and liver cholesterol, phospholipid and triglyceride levels, serum lipoproteins, biliary secretion of cholesterol, phospholipids and bile acids, fecal excretion of sterols and bile acids, and the pool size of bile acids were examined in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKR). SHR showed distinct age- and sex-related changes when young and marked aged-rat hypercholesterolemia after 1 yr of age. (1) Cholesterol shifted from blood to the liver between 10 and 20 wk only in male SHR and not at all in WKR. (2) Serum lipoprotein percentages changes; alpha-lipoprotein decreased, pre-beta-lipoprotein increased, but beta-lipoprotein did not change. These changes appeared only in male SHR and after 13 to 15 wk of age. (3) Liver enlargement in SHR, although not detected at 5 to 6 wk, progressed more rapidly than in WKR, giving values almost double those in WKR after 13 to 15 wk. Liver enlargement in female SHR was much less than in the male. (4) Bile flow, biliary secretion, and the pool size of bile acids increased. However, when expressed on the basis of liver weight, these values were similar to those in WKR, suggesting that the increases were caused by the hepatomegaly. (5) Differences appeared in the bile acid composition. A large amount of beta-muricholic acid was present in SHR of both sexes and the cholic acid percentage was low in male SHR. (6) Changes were observed in fecal bile acid excretion. Since the daily amounts in male SHR were similar to those in WKR, the hepatic synthesis activity (mg per day per 10 g liver) in male SHR was almost half that in WKR at all ages.

Aging↗
PubMed1982

Effects of pH on membrane fluidity of human erythrocytes.

The effects of pH on the membrane fluidity of intact human erythrocytes, ghosts, and their lipid vesicles were studied by spin label techniques in the range of pH 3.0 to 9.1. Two fatty acid spin labels, 5-nitroxide stearic acid (5NS) and 12-nitroxide stearic acid (12NS), and a maleimide spin label were used for the labeling of the membrane lipids and proteins, respectively. The outer hyperfine splitting (T parallel) was measured as a parameter of membrane fluidity. In the case of 5NS, the T parallel values for intact erythrocytes and ghosts remained almost constant over the entire pH range at 22 degrees C but those for their lipid vesicles changed slightly, indicating the vertical displacement of the labels in lipid bilayers. On the other hand, the ESR spectra of 12NS incorporated into intact erythrocytes and ghosts, as compared with their lipid vesicles, showed marked pH dependence. By means of spin labeling of membrane proteins, the conformational changes of the proteins were observed in the pH range mentioned above. These results suggest a possible association between the strong pH dependence of the T parallel values and the conformation changes of membrane proteins. The pH dependence of the membrane fluidity was also investigated in cholesterol-enriched and -depleted erythrocytes. The effects of cholesterol demonstrated that the membrane fluidity was significantly mediated by cholesterol at low pH, but not at high pH.

Cyclic N-Oxides↗