Biomedical subjects

K Yano

Publications and source records attributed to K Yano.

At least 523 records · Page 29Linked to original sources

PubMed1991

Characterization of spinach ferredoxin-thioredoxin reductase.

Ferredoxin-thioredoxin reductase (FTR) is an iron-sulfur protein which, in the presence of ferredoxin and thioredoxin, catalyses the activation of photosynthetic enzymes such as fructose-1,6-bisphosphatase, NADP-malate dehydrogenase and several others. The results from amino acid composition and N- and C-terminal sequences show that spinach FTR is composed of two nonidentical subunits (mol.wt. = 17,200: A; 15,500:B) present in equal amounts. Other components (mol. wt. = 16,300 and 14,200) observed in preparations are most likely derived from subunit A losing its amino terminal part. We report the amino acid compositions of the two subunits A and B of FTR including their partial terminal sequences. Subunit A has an additional amino-terminal serine-rich sequence which is phosphorylated.

Amino Acid Sequence↗

PubMed1991

[Effects of depth on the display of color Doppler flow imaging with transesophageal and transthoracic transducers: an experimental study].

Transesophageal color Doppler flow imaging has proved to provide an accurate and sensitive information for diagnosis of valvular regurgitation. However, it is necessary to understand the difference in the display of color Doppler image between transesophageal and conventional transthoracic transducers for quantitative assessment of valvular regurgitation. In this study, the effects of the depth between transducer and jet flow on color Doppler flow imaging were evaluated with the transesophageal (3.75 MHz) and conventional (2.5 MHz) transducers by using a flow phantom. A flow circuit was filled with saline in which nylon corpuscles (average diameter; 5 microns) were suspended to enhance the Doppler effects. A turbulent jet with constant flow velocity (Reynolds number; 3500) stimulating valvular regurgitant flow was produced in a water bath through a small orifice (2 mm) by constant driving pressure (100 mmHg). Color jet imaging in the long- and short-axis views were observed at each depth with both transducers. The measurement was made every 1 cm in depth from 3 to 12 cm. The color gain setting was fixed at the optimal point so as to get the maximal flow image with the minimal static background noise. We obtained larger image of the color jet signal with the conventional than the transesophageal transducer. Although a mosaic pattern was displayed more distinctly with the transesophageal transducer compared with that of the conventional transducer, the transesophageal image tended to become indistinct in the depth deeper than 8 cm. On the other hand, the transthoracic image was maintained relatively constant at any depth.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗

PubMed1991

[A case report of type II dissecting aneurysm after aortic valve replacement, successful repair by the modified Cabrol's method].

A case of type II dissecting aneurysm after aortic valve replacement was reported. The patient was a 66-year-old man, who was diagnosed as III degree aortic valve regurgitation without aortic dilatation, and performed aortic valve replacement with a 27A Omniscience prosthesis. Postoperative course was very smooth for 7 years, however he was admitted to our hospital of the sudden anterior chest pain. Computed tomography and aortography revealed marked dilatation and dissection of ascending aorta and occlusion of the right coronary artery. The operation of the modified Cabrol's method was performed, and he is well alive one and half a year after operation. Dissecting aneurysm in the late term after aortic valve replacement is rare, and its prognosis and re-operative results are very poor.

Aged↗

PubMed1991

Serum cholesterol and mortality among Japanese-American men. The Honolulu (Hawaii) Heart Program.

Hawaiian men of Japanese ancestry followed up for 18 or more years after a baseline examination showed a quadratic distribution of death rates at different levels of serum cholesterol. Mortality from cancer progressively decreased and mortality from coronary heart disease progressively increased with rising levels of serum cholesterol. There was a positive association between baseline serum cholesterol levels and deaths from coronary heart disease at 0 to 6 years, 7 to 12 years, and 13 years and longer after examination. The inverse relationship between cancer and serum cholesterol levels was stronger in the first 6 years than in the next 6 years and, although still inverse, lost statistical significance after 13 years. Cancers of the colon and lung showed the strongest association with low baseline serum cholesterol levels, while gastric or rectal cancer failed to show this association. Organ specificity and persistence of the inverse association beyond 6 years suggest that the nutritional demands of cancers may not entirely explain the inverse association with some cancers. The quadratic distribution of deaths in this cohort remained after coronary heart disease, stroke, and cancer were removed from the analysis. For the entire period of observation, the lowest mortalities were found in men with serum cholesterol levels between 4.65 and 6.18 mmol/L (between 180 and 239 mg/dL). Manipulation of serum cholesterol levels below this level would not be desirable if this were to result in increased risk of death from cancer or other disease. This study does not rule out this possibility.

Aged↗

PubMed1990

Confluent BALB/c 3T3 cells monolayer provides selective and efficient growth of neoplastic cells.

In an attempt to further characterize non-irradiated contact-inhibited confluent monolayer of BALB/c 3T3 cells (= Contact-Sensitive Plates; CSP) as substrata for in vitro drug sensitivity testing, we compared the efficiency of colony formation with panels of cell lines on CSP with that on plastic dishes or in agar. Tumorigenicity in athymic nude mice was also examined. We found that: (1) HeLa cells, 2 esophageal cancer lines, rat 3Y1 fibroblasts transformed by either adenovirus type 12, mouse polyoma virus, Rous avian sarcoma virus, or plasmid DNA carrying v-Ha-ras oncogene all formed colonies on CSP and in agar and at the same time was tumorigenic. The efficiency of colony formation on CSP proved always to be higher than that in agar. (2) None of the 4 "normal" fibroplastic cell lines formed colonies on CSP or in agar and were tumorigenic. (3) Simian virus 40 and adenovirus E1A gene transformed rat 3Y1 fibroblasts formed colonies on CSP but not in agar, and were not tumorigenic. Therefore, CSP was found to provide selective and efficient growth of neoplastic cells when compared to other substrata and is also helpful in detecting incompletely transformed cells.

Animals↗

PubMed1990

Estradiol sensitivity test using contact-sensitive plates of confluent BALB/c 3T3 cell monolayers.

We have attempted to develop an in vitro assay system for predicting estradiol sensitivity of clinical cancer cells by measuring the effects of estradiol on the net DNA synthesis of primary culture cells. Superinoculation of neoplastic and normal cells onto confluent monolayers of a contact-sensitive cell line, which have been designated as contact-sensitive plates (CSPs), resulted in both the specific growth of the neoplastic cells and the growth inhibition of contact-sensitive normal cells. The applicability of CSPs to an estradiol sensitivity test was examined in the known estradiol-sensitive, estrogen receptor-possessing cell lines, MCF-7 breast cancer and KSE-1 esophageal cancer cells. The responses of each cancer cell to estradiol were sufficiently evaluated in this assay and clearly demonstrated stimulative and inhibitive growth regulatory effects of the estradiol in MCF-7 and KSE-1 cells, respectively. A total of 38 clinical carcinomas (33 of the breast and 5 of the esophagus) were tested for their estradiol sensitivity. A statistically significant increase of cancer cell growth (P less than 0.1) in nontreated culture from the 48th to the 96th h of the primary culture on CSPs was observed in 28 of 38 overall cases (73.7%), and the evaluable data were obtained within 5 days by a sampling of 5 X 10(3) cancer cells. Most of the breast carcinomas exhibited a positive correlation between the growth-stimulative effect of estradiol in this assay and the estrogen receptor levels in the resected specimens. On the other hand, a clinical case of esophageal cancer with an estrogen receptor showed a growth inhibition of primary carcinoma cells by estradiol treatment. These results therefore indicate the feasibility of predicting individual tumor response to estradiol by using a rapid sensitivity test in vitro.

Animals↗

PubMed1990

Correct splicing of modified introns of a Rhizopus proteinase gene in Saccharomyces cerevisiae.

The intron of the Rhizopus aspartic proteinase gene (RNAP-I) was modified by in vitro mutagenesis and examined for its splicing efficiency in Saccharomyces cerevisiae. The wild-type intron of the RNAP-I gene was not spliced at all in spite of its structural similarity to introns of S. cerevisiae. The primary transcript of the RNAP-I gene was converted to correctly translatable mRNA only when the complete consensus sequence of S. cerevisiae introns (i.e. 5'-GTATGT-----TACTAAC-----TAG-3') was introduced into its intron, although the efficiency of splicing was low. It is also shown that transformants carrying the RNAP-I gene with the complete consensus sequence of S. cerevisiae introns produce active RNAP-I protein.

Aspartic Acid Endopeptidases↗

PubMed1990

Replication of an entomopoxvirus in two lepidopteran cell lines.

Pseudaletia separata entomopoxvirus replicated in two lepidopteran cell lines, SIE-MSH-805-F and BM-N. Microscopic examination, and the virus passage tests, of infected cultures indicated that the virus replicated more readily in the former cell line. Virus release by exocytosis occurred in both cell lines. A sequence of virus morphogenesis in the cultured cells was described, based on electron microscopic observations of thin sections. The nucleus of infected cells contained spherical inclusions, and the cytoplasm contained virions, immature virus forms, spheroids, and spindles. A portion of the virions in the cytoplasm was occluded within spheroids, which were often associated with crystallogenic matrix. Virions acquired a coat prior to their occlusion.

Animals↗

PubMed1990

Smoking, pulmonary function, and mortality.

The association of pulmonary function (as percent of predicted forced expiratory volume in 1 second [FEV1]) with total and cause-specific mortality over 15 to 18 years was investigated in a large cohort (5924) of prospectively followed Japanese-American men. Among those who never smoked, pulmonary function was found not to be significantly predictive of total mortality in a multivariate model in which adjustment for variables that might confound the results was made. Among past and current smokers, highly significant associations were found (P < 0.0001). The positive relationship of pulmonary function to mortality in smokers was so strong that it overshadowed these differences in nonsmokers in a model including all smoking groups combined, even after adjusting for smoking. A smoking-pulmonary function interaction term added to this model was statistically significant (P < 0.003). This illustrates the need for attention to the potential for complex interactions between biologic variables when carrying out multivariate statistical analysis. Findings for cardiovascular and noncardiovascular mortality were similar. This analysis indicates that while pulmonary function is associated with subsequent mortality, the relationship is significantly associated with smoking history.

Asian↗

PubMed1990

Health status and life style in elderly Japanese men with a long life expectancy.

The Japanese population in Hawaii has one of the longest life expectancies of any large population subgroup in the U.S. and the world. Cross-sectional data on 1,379 elderly, noninstitutionalized, male Japanese American survivors of a population-based cohort study indicated the most common health problems were hypertension (43%), arthritis (33%), diabetes (13%), and gout (9%). For cancer and hypertension there is a trend toward higher prevalence in older age groups. For coronary heart disease, stroke, and angina the oldest age group (75-81 years) has a higher prevalence than that seen in younger age groups. Other relatively common diseases such as diabetes, gout, peptic ulcer, and arthritis do not have higher prevalence in older age groups. Drugs reported to be used frequently by study participants were for hypertension, gout, CHD, and diabetes. The prevalence rates of major limitations of mobility and of living alone appear to be relatively low in this population. Less than one percent of the current population rate their health status as poor. The prevalence of normal serum cholesterol and smoking are similar to those seen in U.S. White males, while the rates of hypertension appear lower. Prevalence rates for stroke and heart attack also appear to be somewhat lower in these long-lived individuals than those seen in U.S. Whites.

Activities of Daily Living↗

PubMed1990

Potential bias due to prevalent diseases in prospective studies.

In prospective studies, subjects found to have the disease under investigation at the initial screening examination are commonly excluded from analyses. However, the possibility of bias due to prevalent conditions other than the disease of interest is usually not considered. In the present study, an algebraic development enables analysis of the effects of inclusion and exclusion of subjects with certain prevalent conditions upon risk estimates. Hypothetical data are presented for which an association between a risk factor and an incident disease could become null or even reversed after removing subjects with certain prevalent diseases. Bias appears even when the only association present is between risk factor and total disease incidence. Data from the Honolulu Heart Study also have been used to illustrate this finding, examining the association between coronary heart disease (CHD) incidence and smoking. Decisions regarding the inclusion or exclusion of subjects with prevalent diseases requires prior knowledge of alteration of usual risk factors levels by individuals with these diseases. Simply removing all subjects with prevalent diseases might on the contrary create bias. Therefore, people with prevalent diseases should be screened for potential alteration of their risk factor levels as a result of the diseases. The situation becomes still more complex when several risk factors and prevalent diseases need to be considered at the same time as it happens in multivariate analyses. Because this situation represents a bias, and not confounding or effect modification, controlling for the effect of prevalent diseases is not appropriate.

Aged↗

PubMed1990

Screening test for hormone sensitivity by the autoradiographic method using cell mats.

We developed an autoradiographic screening test for hormone sensitivity of single cell suspensions of tumor tissues on cell mats, which inhibited the growth of normal cells alone. We applied this method to our newly established KSE-1 line derived from esophageal carcinoma and compared this method with well-established cytoplasmic and nuclear assays. Our assay, though taking longer to implement and providing only qualitative information, requires significantly smaller specimens than the current biochemical assay and will predict the hormone sensitivity of only viable neoplastic cells.

Animals↗

PubMed1990

Treatment of tattoos with pure epidermal sheet grafting.

We treated tattoos with a new method in which the epidermis of the tattooed skin was replaced after removing the dermis, which contained tattoo pigments. The separation of the epidermis from the dermis was performed enzymatically with the use of dispase. The time required for healing of the wound was markedly shortened.

Female↗

PubMed1990

Results of the Allen test on 2,940 arms.

The ulnar arterial circulation to bilateral hands of 683 men and 787 women was assessed with the Allen radial artery compression test. Of the 2,940 arms, the Allen test showed abnormalities in 105 (3.6%). The incidence of abnormality generally increased with age: 2.2% in the first decade and 6.9% after the ninth decade. It is very likely that circulatory failure in the hand develops after several decades among those whose radial artery was removed in their youth. When the radial artery is removed in the young, attention should therefore be paid to future consequences.

Adolescent↗

PubMed1990

Congenital fistula of the dural carotid-cavernous sinus: case report and review of the literature.

The case of a 2-month-old boy with a congenital fistula of the dural carotid-cavernous sinus is presented. This is a rare vascular anomaly in infancy, and it may cause acute changes in vision. The child was initially followed up for 1 year to see if spontaneous thrombosis would occur. The symptoms persisted, however, and intravascular surgery using platinum coils was performed for closure. After treatment, the symptoms completely resolved. Literature pertaining to this anomaly has been reviewed with particular emphasis on dural fistulas of the cavernous, transverse, sigmoid, and straight sinuses in infancy.

Arteriovenous Fistula↗

PubMed1990

Transformation-specific decrease of phosphorylation of 80K protein, a substrate of protein kinase C, in NIH3T3 cells.

Phosphorylation in normal and transformed NIH3T3 cells of the 80K protein, a specific substrate for protein kinase C, was compared by means of two-dimensional gel analysis. We obtained evidence that NIH3T3 cells transformed by the c-raf or H-ras oncogene maintained a decreased level of phosphorylation of the 80K protein, with or without phorbol ester (TPA)-stimulation, at all concentrations of serum tested while normal NIH3T3 cells maintained an elevated level of phosphorylation of the 80K protein. Furthermore, NIH3T3 cells transformed by N-ras, K-ras, src, mos or polyoma middle T antigen exhibited a decreased level of phosphorylation of the 80K protein. These events were confirmed by an analysis of a hormone-inducible H-ras transformant. Thus, phosphorylation of the 80K protein is inversely correlated with cellular transformation.

Cell Line, Transformed↗

PubMed1990

Molecular cloning, nucleotide sequencing, and expression of the Bacillus subtilis (natto) IAM1212 alpha-amylase gene, which encodes an alpha-amylase structurally similar to but enzymatically distinct from that of B. subtilis 2633.

An alpha-amylase gene of Bacillus subtilis (natto) IAM1212 was cloned in a lambda EMBL3 bacteriophage vector, and the nucleotide sequence was determined. An open reading frame encoding the alpha-amylase (AMY1212) consists of 1,431 base pairs and contains 477 amino acid residues, which is the same in size as the alpha-amylase (AMY2633) of B. subtilis 2633, an alpha-amylase-hyperproducing strain, and smaller than that of B. subtilis 168, Marburg strain. The amino acid sequence of AMY1212 is different from that of AMY2633 at five residues. Enzymatic properties of these two alpha-amylases were examined by introducing the cloned genes into an alpha-amylase-deficient strain, B. subtilis M15. It was revealed that products of soluble starch hydrolyzed by AMY1212 are maltose and maltotriose, while those of AMY2633 are glucose and maltose. From the detailed analyses with oligosaccharides as substrates, it was concluded that the difference in hydrolysis products of the two similar alpha-amylases should be ascribed to the different activity hydrolyzing low-molecular-weight substrates, especially maltotriose; AMY1212 slowly hydrolyzes maltotetraose and cannot hydrolyze maltotriose, while AMY2633 efficiently hydrolyzes maltotetraose and maltotriose. Further analyses with chimeric alpha-amylase molecules constructed from the cloned genes revealed that only one amino acid substitution is responsible for the differences in hydrolysis products.

Amino Acid Sequence↗

PubMed1990

Suppression of exercise-induced ventricular arrhythmias by propranolol and diltiazem in a woman without organic heart disease--a case report.

A thirty-five-year-old woman without organic heart disease who has exercise-induced ventricular arrhythmias suppressed by propranolol and diltiazem is reported. Treadmill exercise provoked reproducibly nonsustained ventricular tachycardia (NSVT) and salvos of ventricular premature contraction (VPC). QRS morphology of these ventricular arrhythmias showed left bundle branch block pattern and right axis deviation. Oral propranolol (20 mg) and diltiazem (90 mg) prevented exercise provocation of NSVT and VPC. However, oral mexiletine (200 mg) and procainamide (500 mg) could not prevent exercise provocation of these ventricular arrhythmias. No ventricular arrhythmias could be induced by any form of ventricular extrastimulations. Right ventricular pacing at a rate of 210 beats/minute provoked NSVT of which the QRS morphology was similar to that of exercise-induced NSVT. Triggered activity may be a possible electrophysiologic mechanism for exercise-induced ventricular arrhythmias in this patient, although other mechanisms such as reentry and enhanced automaticity could not be completely excluded.

Adult↗