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Biomedical subjects

Y Tanabe

Publications and source records attributed to Y Tanabe.

At least 289 records · Page 16Linked to original sources

Diabetes mellitus in Kearns-Sayre syndrome.

A 20-year-old woman with Kearns-Sayre syndrome (KSS) suddenly experienced two episodes of diabetic coma. She was studied to determine whether diabetes mellitus (DM) resulted from insulin resistance or from an insulin secretion abnormality, using the euglycemic glucose clamp technique and the glucagon tolerance test. She had a deficiency of insulin secretion from beta cells. It is important to recognize in practice the onset of DM in patients with mitochondrial myopathy. We would suggest that a genetic linkage or mitochondrial dysfunction may be responsible for the association of both disease states.

Adult↗

Effect of mild aerobic exercise on lipid and apolipoprotein levels in patients with essential hypertension.

The effects of supervised mild aerobic exercise at the work load of the blood lactate threshold for 10 weeks on serum lipids and apolipoproteins were studied in 24 patients with essential hypertension. Significant reduction in both systolic and diastolic blood pressure and increased maximal oxygen uptake were observed in both men and women. The high density lipoprotein cholesterol increased significantly following mild aerobic exercise in women. Apolipoprotein A-II was significantly elevated at the 4th week in women. No significant differences in total cholesterol, triglyceride, low density lipoprotein cholesterol, apolipoproteins A-I, C-II, C-III, B and E were observed in either men or women following an exercise program. These data demonstrate the different effect of mild aerobic exercise therapy on high density lipoprotein in hypertensive men and women.

Adult↗

Plasma abnormal prothrombin levels in patients with small hepatocellular carcinoma.

The diagnostic value of plasma abnormal prothrombin (PIVKA-II) measurements in detecting relatively small hepatocellular carcinomas (HCC), less than 5 cm in diameter, was compared with that of serum alpha-fetoprotein (AFP) determinations. Among 18 patients with relatively small hepatocellular carcinoma (HCC), abnormal PIVKA-II values were found in only three (16.6%). Highly elevated serum AFP levels (greater than 200 ng/ml) relatively specific for HCC were seen also in three patients. However, nonspecific elevation of PIVKA-II in patients with liver cirrhosis not accompanied by HCC was much less than that of AFP. Although complementary, both tests appear to be of limited value in early detection of HCC, indicating that searches for other markers are necessary, to allow early detection of small HCC.

Aged↗

Biological activities of novel recombinant tumor necrosis factor having N-terminal amino acid sequences derived from cytotoxic factors produced by THP-1 cells.

Eight species of novel recombinant tumor necrosis factor-S (rTNF-SAM group) were constructed in which N-terminal amino acid sequences were based on that of TNF-S from THP-1 cells with higher basicity than conventional rTNF-alpha. Two of this rTNF-SAM group, denoted as rTNF-SAM1 and rTNF-SAM2, showed more cytocidal activity on A549 lung carcinoma cells and G401 Wilm's tumor cells than did rTNF-alpha. In addition to these cell lines, rTNF-SAM1 revealed strong cytocidal activity on T24 bladder carcinoma cells, which are resistant to rTNF-alpha. Moreover, possible cachectin activity of rTNF-SAM2 seemed to be lower than that of conventional rTNF-alpha, suggesting that rTNF-SAM2 has less side effects. Actually, toxicity as expressed by LD50 value of rTNF-SAM2 as well as others of the rTNF-SAM group was significantly lower than that of conventional rTNF-alpha. Thus, newly constructed rTNF-SAM1 and rTNF-SAM2 should be more promising antitumor reagents for clinical use, since they were shown to be superior to conventional rTNF-alpha both in antitumor effect and in less side effects.

Amino Acid Sequence↗

[Re-evaluation of determinants of the cardiothoracic ratio using two-dimensional echocardiography].

To evaluate the correlation of cardiothoracic ratios (CTR) on chest radiography with the sizes of the four cardiac chambers, we studied 41 normal persons and 77 cardiac patients using two-dimensional echocardiography (2DE). The transverse cardiac diameter and the CTR were ascertained from their chest radiographs. Using 2DE, each cardiac chamber was evaluated three-dimensionally, by measuring the short and long diameters of each left (LV) and right ventricle (RV), the diameter of the RV outflow, the anteroposterior, transverse, and long diameters of each left (LA) and right atrium (RA). These values were corrected using the square root of the body surface area. The correlation coefficient for the CTR was greatest in the long diameter of the LA (r = 0.84), and was greater in the atrial diameters (r greater than or equal to 0.71) than in the other diameters except for the transverse diameter of the RA (r less than or equal to 0.51). The contribution of each cardiac chamber to the transverse cardiac diameter was evaluated in 34 patients with cardiac enlargement by a method using the null hypothesis, which we originally designed. Consequently, the contribution of the LV to the CTR was definitely proven in two patients, that of RV in two, that of LA in 15 and that of RA in nine. These results indicated that the CTR is strongly influenced by enlargement of the LA.

Echocardiography↗

Improvement of cytotoxicity of tumor necrosis factor (TNF) by increase in basicity of its N-terminal region.

Two new recombinant TNFs (named rTNF-Scw1 and -Scw2) with higher basicity than conventional recombinant human TNF-alpha (rTNF-alpha) in the N-terminal region were constructed. Their sequences were constructed based on those of partially purified cytotoxic factors from the culture supernatant of acute monocytic leukemia cells THP-1, which unlike rTNF-alpha are cytotoxic to T24 bladder carcinoma cells in vitro. These new rTNF-Ss showed a broader cytotoxicity to tumor cells than rTNF-alpha. This increase in the basicity of the N-terminal region over that of conventional TNF significantly increased the cytotoxicity on tumor cells in vivo as well as in vitro.

Amino Acid Sequence↗

Sex difference in responsiveness to Aztreonam of monooxygenase system in liver microsomes from rats.

Effect of successive administration of Aztreonam on microsomal monooxygenase system was investigated in male and female Sprague-Dawley rats. The activities of benzphetamine N-demethylase, aminopyrine N-demethylase, p-nitroanisole O-demethylase and aniline hydroxylase in liver microsomes from male rats were decreased dose-dependently by Aztreonam. On the contrary, the activities in liver microsomes from female rats were slightly increased rather than decreased by the administration of Aztreonam. In addition, Aztreonam was found to decrease the specific content of microsomal cytochrome P-450 in male rats but not in female rats. The decreases in the activities observed in male rats were accompanied by a parallel decrease in the specific content of cytochrome P-450. Furthermore, the results of quantitation of P-450 (M-1), one of the male specific forms of cytochrome P-450, indicated that the administration of Aztreonam resulted in a dose-dependent decrease in the content of P-450 (M-1) in liver microsomes from male rats.

Aminopyrine N-Demethylase↗

Muscle fiber growth and necrosis in dystrophic muscles: a comparative study between dy and mdx mice.

Histopathological and morphometric studies of murine dystrophic muscles in the early postnatal period were performed. In dy mice, obtained by in vitro fertilization, scattered necrotic fibers were noted at 10 days of age followed by poorly compensated regeneration leading to muscle fiber loss, marked variation in fiber size, and fibrous and adipose tissue proliferation. In mdx mice, clusters of necrotic muscle fibers seen at 10-15 days were followed by well compensated regeneration with little fibrosis. There appeared to be no delay in muscle fiber growth and fiber type differentiation in both dy and mdx mice up to 10 days of age since there was no distinct difference in muscle fiber size, fiber type differentiation and the incidence of myosatellite cells between dystrophic muscles and those from age-matched control mice. Muscle fibers appeared to undergo necrosis only when they had reached a certain stage of maturation since at early stages of development or regeneration they rarely became necrotic. The difference in clinical symptoms between dy and mdx mice may result from differences in their regenerative response to necrosis.

Animals↗

Congenital myotonic dystrophy. Changes in muscle pathology with ageing.

Undifferentiated type 2C fibers and satellite cells were increased in number in younger patients with congenital myotonic dystrophy (CMD) indicating immaturity in muscle fiber growth. The changes found in a 38-year-old man with CMD were identical to those described in late onset myotonic dystrophy. Type 1 fibers were found to become predominant with age. This suggests that in this disorder fiber type transformation progresses with age, presumably due to abnormal neural influences or aberrant sarcolemmal responses.

Adult↗

Antihypertensive and volume-depleting effects of mild exercise on essential hypertension.

After a general clinical observation period of over 4 weeks, 20 essential hypertensive subjects (Japanese) were randomly divided into two groups. One group (n = 10; 4 men and 6 women; 51.4 +/- 2.8 years of age) agreed to physical training using bicycle ergometer exercise with the intensity at blood lactate threshold for 60 minutes three times a week for 10 weeks, while the other group (n = 10; 4 men and 6 women; 51.0 +/- 2.9 years of age) did no particular physical training and was followed once a week as the control. Changes in blood pressure, hemodynamics, and humoral factors of the exercised group were compared with values in the controls. The following significant changes were found only in the exercised group. Blood pressure was significantly (p less than 0.01) reduced. Whole blood and plasma volume indices were significantly reduced (p less than 0.05, p less than 0.01, respectively). The change in ratio of serum sodium to potassium positively correlated with the change in systolic blood pressure (r = 0.76, p less than 0.02). Plasma norepinephrine concentrations both at rest and at the workload of blood lactate threshold during graded exercise tests were significantly reduced (p less than 0.05, p less than 0.02 respectively) after 10 weeks of exercise training. The change in the resting level of plasma norepinephrine positively correlated with that in the mean blood pressure. No such changes were observed in the control group. In both groups, body weight and urinary sodium excretion showed no statistically significant changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Cockayne syndrome with delayed recovery of RNA synthesis after ultraviolet irradiation but normal ultraviolet survival.

We report a girl with Cockayne syndrome (CS) with atypical cellular features. We studied the ultraviolet (UV)-sensitivity of cultured fibroblast cells derived from this case and male CS siblings as positive controls. Cells from this female with CS displayed normal unscheduled DNA synthesis and repair replication capacity. However, the cells also displayed a less depressed level of RNA synthesis after UV irradiation, compared to control CS cells, and showed normal UV survival. This CS case with early onset of abnormalities had more serious clinical manifestations than the control CS siblings. These cytological results suggest that there is considerable clinical and cellular heterogeneity in CS and that cellular sensitivity to UV might not be as essential for the diagnosis of CS as previously thought.

Adolescent↗

Effect of mild aerobic exercise on serum lipids and apolipoproteins in patients with coronary artery disease.

The effects of mild aerobic exercise on serum lipids, apolipoproteins and lecithin-cholesterol acyltransferase (LCAT) activity were examined in 11 male patients with coronary artery disease and 4 healthy male controls. The mild aerobic exercise program involved exercise intensity at 50% of maximal oxygen uptake, as determined from the blood lactate threshold, for 60 min periods 3 times per week for 10 weeks. Following mild aerobic exercise, serum levels of high density lipoprotein cholesterol (HDL-C) were increased significantly from 50 +/- 7 mg/dl to 59 +/- 11 mg/dl (p less than 0.05) with a simultaneous increase in apolipoprotein A-I (apo A-I) in normal controls. The LCAT activity was significantly increased from 65 +/- 22 nmol/ml/hr to 99 +/- 30 nmol/ml/hr in normal controls (p less than 0.05). Furthermore, maximal oxygen uptake (VO2max) was significantly increased in normal controls. In contrast, no significant changes were found in HDL-C, apo A-I, apo B, VO2max and body weight in patients with coronary artery disease. There was significant correlation between the initial HDL-C level and the change in HDL-C level following the exercise program in the combined group of normal controls and patients with coronary artery disease.

Aerobiosis↗