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Biomedical subjects

K Yano

Publications and source records attributed to K Yano.

At least 613 records · Page 34Linked to original sources
PubMed1987

Nucleotide sequencing analysis of a LEU gene of Candida maltosa which complements leuB mutation of Escherichia coli and leu2 mutation of Saccharomyces cerevisiae.

The expression of a LEU gene from Candida maltosa (designated as C-LEU2) isolated previously (Kawamura et al. 1983) was shown to be regulated, when transferred into Saccharomyces cerevisiae, by leucine and threonine in the medium, as in the case of LEU2 gene of S. cerevisiae. The coding region together with the regulatory region was subcloned and the nucleotide sequence was determined. When the sequence of the coding region was compared with that of LEU2, the homology was 72% for base pairs and 76% for deduced amino acids. Comparison of the regulatory region of C-LEU2 with those of LEU1 and LEU2 suggested a few short consensus sequences which are involved in regulation of gene expression by leucine and threonine in the medium.

3-Isopropylmalate Dehydrogenase↗
PubMed1987

Postmortem findings in sudden and non-sudden deaths among Japanese-American men in Hawaii.

Analyses were made of the cause of death and major pathologic findings among 1,085 autopsied Japanese-American men in Hawaii to determine the differences between the 167 men who experienced sudden death within 24 hours of being well and the 918 men with non-sudden death. Sudden deaths were further divided into three subgroups according to the interval from the onset of symptoms to death: (less than one hour; one to six hours; more than six hours). Nearly 90 percent of sudden deaths and 25 percent of non-sudden deaths were attributed to cardiovascular disease. The proportion of deaths due to coronary heart disease was highest in sudden deaths less than one hour (72 percent) and lowest in sudden deaths more than six hours (49 percent), whereas the proportion of stroke deaths was highest in sudden deaths more than six hours (37 percent) and lowest in sudden deaths less than one hour (9 percent). The prevalence of myocardial infarction and the grade of coronary atherosclerosis were also significantly greater for sudden deaths (especially sudden deaths less than one hour) than for non-sudden deaths.

Aged↗
PubMed1987

Growth inhibitors in serum, platelets, and normal and malignant tissues.

The non-malignant epithelial cell line from Buffalo rat liver (BRL) and its malignant transformant obtained by Rous sarcoma virus infection (RSV-BRL) were used as the indicators. A survey was made in animals for growth inhibitors which could inhibit the growth of BRL, but not the growth of RSV-BRL in culture, under the consideration that the loss of the sensitivity to such inhibitors might be the most dominant cause for acquisition of tumorigenicity. From human platelets, a growth inhibitor was extracted with acid-ethanol and prepared to a homogeneous purity, separated from the major TGF-beta activity, which stimulated the anchorage-independent growth of NRK cells in the presence of EGF. The purified inhibitor (Mr 25-27k; pI 8.7-9.1) showed 50% inhibition on the growth of BRL at 20 pg/ml (0.7 pM), but hardly influenced the growth of RSV-BRL. Its inhibition was specific to epithelial cell lines, thus called epithelial growth inhibitor (EGI). It consisted of two subunits with practically identical Mr, which were cross-linked with disulfide bonds. Its sequence of N-terminal 10 amino acids was consistent with that of TGF-beta. In rats, serum contained a growth inhibitor with Mm 220k. The inhibitor, when treated with high concentrations of urea or guanidine-HCl, liberated an active component with Mr 30k and pI 5.2. When the growth inhibitor with Mm 220k was treated with ethanol-acetone or 1 M acetic acid, its activity increased more than 10-fold. Growth inhibitors were extracted with acid-ethanol from various tissues of rats. The activities of the extracts to inhibit the growth of BRL cells were high in spleen, lung and tumors with relatively high mitotic activities, but low in muscle, heart and brain. Acid-ethanol extract from BRL cells showed growth inhibitory activity toward BRL cells themselves significantly higher than that from RSV-BRL cells. The serum-free media conditioned with BRL and RSV-BRL cells showed a little growth inhibitory activity toward BRL cells. On treatment with acetic acid, their activities increased significantly, comparable for both types of cells. The media thus activated inhibited the growth of BRL cells, but not that of RSV-BRL cells. All the growth inhibitors described above including human platelet inhibitor, whether present in extracts or purified, resembled one another in stability against acid, heat and reducing reagents.

Animals↗
PubMed1987

A new orthodontic force system of magnetic brackets.

Tooth movement in orthodontic treatment is achieved by a combination of mechanical and physiologic forces acting on the teeth and their supporting structures to effect the biologic changes that cause teeth to move through bone. Traditional orthodontic appliances using wires, springs, and elastic forces inevitably cause some degree of discomfort and pain. In the present study, a new magnetized edgewise bracket was designed. The magnet works to move teeth mesiodistally and is not merely a mechanical force. It is well adapted to the biophysical system of tooth and bone interrelationships. Therefore, it works effectively, gives less discomfort, and produces less stress for the patient. The new magnetic appliance provides a force system that approaches the ideal orthodontic requirements.

Adolescent↗
PubMed1987

Asystole with syncope following strenuous exercise in a man without organic heart disease.

A 29-year-old man without organic heart disease who had a history of six episodes of syncope following sudden cessation of strenuous exercise over the last 18 years was reported. Resting electrocardiogram and 24-hour electrocardiographic monitoring did not show any rhythm disturbance or ischemic changes. Sinus node recovery time, sinoatrial conduction time and A-V conduction were normal on electrophysiologic study. Asystole with syncope occurred immediately following sudden cessation of strenuous exercise and following release of intrathoracic pressure during Valsalva's maneuver performed after subcutaneous administration of 0.5 mg of epinephrine. However, Master's single two-step test and Valsalva's maneuver performed without epinephrine could not evoke asystole. It was assumed from these results that transient overactivity of the autonomic nervous system and sympathetic-parasympathetic interactions were the underlying factors responsible for the occurrence of asystole following sudden cessation of strenuous exercise in the present case.

Adult↗
PubMed1987

Modification of growth rate of Toxoplasma gondii by continuous passage in immune mice.

Growth of the RH strain of Toxoplasma gondii, is suppressed in mice immunized with Toxoplasma antigens. At the second passage, the growth of T. gondii harvested from immune mice is suppressed more strongly in immune mice than that of T. gondii from control mice. After 52 passages in immune mice, the growth of T. gondii was still suppressed in immune mice than in control mice. T. gondii did not possess ability of antigenic variation (Pfefferkorn et al., 1983). After vaccination with the S-273 strain of T. gondii, mice were challenged twice with the RH strain. Cysts in brains caused death of all mice by inoculation at the 1st, 2nd, 3rd, 4th and 8th week after the second challenge of the RH strain. But the cysts from mice at the 16th and 30th week have decreased virulence, causing death in only 2 out of 4 and 1 out of 4 mice, respectively. Virulence of cysts had no definite relationship to Toxoplasma antibodies by indirect latex agglutination test and the numbers of cysts per brain. Growth variation of T. gondii is proposed under unfavourable conditions as in mice immunized with Toxoplasma antigens or vaccinated with the S-273 strain.

Animals↗
PubMed1987

Relationship of magnesium intake and other dietary factors to blood pressure: the Honolulu heart study.

Associations between blood pressure and intakes of 61 dietary variables assessed by 24-h recall method were investigated in 615 men of Japanese ancestry living in Hawaii who had no history of cardiovascular disease or treated hypertension. Magnesium, calcium, phosphorus, potassium, fiber, vegetable protein, starch, vitamin C, and vitamin D intakes were significant variables that showed inverse associations with blood pressure in univariate and a multivariate analyses. Magnesium had the strongest association with blood pressure, which supports recent interest in its relation to blood pressure. Nevertheless, it was not possible to separate the effect of magnesium from that of other variables because of the problem of high intercorrelation among many nutrients. While recommendations based upon cross-sectional studies must be viewed cautiously, these results suggest that foods such as vegetables, fruits, whole grains, and low-fat dairy items are major sources of nutrients that may be protective against hypertension.

Aged↗
PubMed1987

Calcium-induced weakening of Z-disks in postmortem skeletal muscle.

The reaction mechanism of calcium ion in the postmortem weakening of Z-disks was studied in myofibrils prepared from fresh or stored muscles. The alpha-actinin content in myofibrils remained almost unchanged within 10 days postmortem, showing very limited proteolysis of myofibrils during postmortem storage of muscles at 10 degrees C. The postmortem weakening of Z-disks was markedly dependent on muscle pH, showing a minimum at pH 6.5. These results agree well with the calcium-induced weakening of Z-disks of freshly isolated myofibrils, indicating that no protease participates in the postmortem weakening of Z-disks. Z-Disks of myofibrils prepared from stored muscles split into halves after treatment with 0.1 N NaOH for 5 min. The identical splitting of Z-disks was induced by a calcium ion concentration of 10(-4)M, which is of the same order of magnitude as that in the sarcoplasm in postmortem muscle. We therefore conclude that the postmortem weakening of Z-disks is non-enzymatically induced by the raised sarcoplasmic calcium ion concentration of 10(-4) M. Calcium ions probably solubilize the amorphous cementing material of Z-disks, leaving unchanged the two sets of Z filaments composed of alpha-actinin.

Actinin↗
PubMed1987

Histological study of the development of cartilage after perichondrial vascularized grafting.

The authors investigated histologically the process of neocartilage formation in vascularized transplantation of rabbit ear perichondrium. The chondrocytes made their first appearance 4 days after transplantation, and the appositional growth of neocartilage lasted for about 3 weeks, although maximum growth occurred in the first 9 days after transplantation. The neoperichondrium of neocartilage was not observed until its gradual appearance at the end of this period of remarkable appositional growth. The time required for the neocartilage to become mature varied, and some cartilage was still not mature at 6 months after transplantation.

Animals↗
PubMed1987

Unilateral athelia with a subcutaneous dermoid cyst.

A case of unilateral athelia with a subcutaneous dermoid cyst in the area in question is reported. The histologic features of the cyst wall suggest that it is derived from a base in the nipple-areola complex. Dozens of cases of congenital absence of the breast have been reported, some of them associated with congenital anhidrotic ectodermal dysplasia, others with additional musculoskeletal abnormalities, and still others normal in other respects. But to our knowledge, the combination of athelia and corresponding subcutaneous dermoid cyst has not been reported.

Adolescent↗
PubMed1987

Urine growth hormone determinations compared with other methods in the assessment of growth hormone secretion.

Urinary excretion of hGH was studied in children with short stature using a sensitive sandwich enzyme immunoassay technique. Urinary hGH excretion, in terms of hGH: creatinine ratio, showed excellent correlation with the mean and peak hGH values during physiological and pharmacological tests. It seems that the urinary hGH levels reflect serum hGH profiles during the urine collection period. A border zone for the lower limits of normal hGH levels in the urine was 7.5-13.4 ng/g creatinine for the physiological test at night (from 2000 hours to 0600 hours) and 17.4-35.0 ng/g creatinine for the pharmacological tests. Assessment of hGH secretory status by the urinary hGH levels showed good agreement with the serum hGH response. Measurement of urinary hGH could be used as a diagnostic test for impaired hGH secretion, and the multiple blood drawing required in physiological and pharmacological tests might be replaced by urine sampling.

Child↗
PubMed1987

Nucleotide sequencing and characterization of the genes encoding benzene oxidation enzymes of Pseudomonas putida.

The nucleotide sequence of the genes from Pseudomonas putida encoding oxidation of benzene to catechol was determined. Five open reading frames were found in the sequence. Four corresponding protein molecules were detected by a DNA-directed in vitro translation system. Escherichia coli cells containing the fragment with the four open reading frames transformed benzene to cis-benzene glycol, which is an intermediate of the oxidation of benzene to catechol. The relation between the product of each cistron and the components of the benzene oxidation enzyme system is discussed.

Amino Acid Sequence↗
PubMed1987

Pharmacokinetics of methimazole in children and adolescents with Graves' disease. Studies on plasma and intrathyroidal concentrations.

Methimazole concentrations in plasma and in the thyroid glands were measured by means of high-performance liquid chromatography. Pharmacokinetics of methimazole were studied after a single oral dose (175 mumol/m2) in nine children and adolescent who were in the thyrotoxic state. Plasma levels of methimazole showed peak concentrations of 4.4 to 12.6 (median 9.2) mumol/l at 0.5 to 4 h after drug administration. Plasma half-life, area under the curve, and distribution volume ranged from 2.73 to 6.04 h, 32.8 to 77.9 mumol X l-1 X h-1, and 0.516 to 0.913 l/kg, respectively. These pharmacokinetic parameters showed a wide variation among the patients, but were quite reproducible in the same subject. Intrathyroidal concentrations of methimazole were measured in another nine subjects including four adolescents and five adults who underwent thyroidectomy. The drug concentrations in the thyroid glands ranged between 3.5 and 23.8 mumol/kg tissue and were far higher than those in the plasma obtained at the time of surgery. In this series of experiments, the dose of the drug varied from 76 to 319 mumol/m2, time after the last dose to surgery from 5 to 24 h, and the mode of drug administration from a single to three divided doses. Among these variable factors, only the daily dose of methimazole corrected by body surface area showed significant correlation with the intrathyroidal concentration, whereas the time after the last dose of the drug and the mode of drug administration did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1987

Influence of collateral flow reduction on electrophysiologic properties of preexisting ischemic area and inducibility of ventricular arrhythmias in the dog.

Electrophysiologic properties of the left ventricle, vulnerability to ventricular arrhythmias and regional myocardial blood flow (RMBF) of the left ventricle were examined during superposition of acute ischemia on a healed myocardial infarction. The left circumflex coronary artery (LCX) was ligated in 13 dogs with a 28-day-old anteroapical infarction. Six (46%) of 13 dogs had reproducible ventricular tachycardia in response to programmed ventricular stimulation before LCX ligation. Ventricular fibrillation could be induced in 2 of these 6 dogs. After LCX ligation, 11 (85%) of 13 dogs had ventricular arrhythmias induced by ventricular stimulation. Nine of 13 dogs had ventricular tachycardia and 7 of 13 dogs had ventricular fibrillation. The heterogeneity of the effective refractory period (delta ERP) and the local intraventricular conduction time (LIVCT) in the border and the infarct zones of the left ventricle increased significantly after LCX ligation. RMBF in the border and the infarct zones were markedly decreased by LCX ligation. The magnitude of reduction of RMBF was correlated significantly with the prolongation of LIVCT. In conclusion, acute critical reduction of the collateral blood supply causes a more heterogeneous refractory period and conduction delay in the preexisting ischemic area of the heart, increasing the vulnerability to lethal ventricular arrhythmias.

Animals↗
PubMed1987

Postchallenge glucose concentration and coronary heart disease in men of Japanese ancestry. Honolulu Heart Program.

Since 1965, the Honolulu Heart Program has followed 8006 men of Japanese ancestry, aged 45-70 yr at study entry, for the development of cardiovascular disease. To investigate the role of glucose concentration 1 h after a 50-g challenge on the risk of fatal coronary heart disease (CHD) and nonfatal myocardial infarction (MI), 6394 nondiabetic men were followed for 12 yr for the first development of CHD. The rate of fatal CHD increased linearly with amount of glucose. Men in the fourth quintile of postchallenge glucose (157-189 mg/dl) had twice the age-adjusted risk of fatal CHD of those in the lowest quintile (P less than .05). Relative risk increased to threefold among those in the top quintile and remained statistically significant after adjustment for other risk factors including body mass, total cholesterol, hypertension, left ventricular hypertrophy, and hematocrit (P less than .001). When glucose was considered as a linear term in the proportional hazards model, a highly significant relation was noted with fatal CHD alone and when combined with nonfatal MI (P less than .001). We conclude that a continuously increasing risk gradient exists between postchallenge glucose and subsequent CHD that is independent of other known risk factors.

Aged↗
PubMed1987

Pyrroxamycin, a new antibiotic taxonomy, fermentation, isolation, structure determination and biological properties.

A strain of streptomycete was found to produce a new antibiotic pyrroxamycin. This compound was isolated from the culture broth of Streptomyces sp. S46506. The chemical structure was determined to be 4,5-dichloro-2-(6',8'-dichloro-4'H-1',3'-benzodioxin-4'-yl)-3-nitr opyrrole by its chemical character and 1H and 13C NMR spectral analysis. Pyrroxamycin was active against Gram-positive bacteria and dermatophytes.

Anti-Bacterial Agents↗