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Biomedical subjects

R Sasaki

Publications and source records attributed to R Sasaki.

At least 217 records · Page 12Linked to original sources

Family history of cancer and mortality among patients gastrectomized because of benign gastric diseases.

A preliminary result from a cohort study on the association of a family history of cancer with mortality is discussed in this paper. Among 2200 patients (1912 males and 288 females) gastrectomized because of benign gastric diseases, 274 male patients, and 40 female patients had a family history of cancer. During 2750 person-years of observation, 22 patients with the family history of cancer were found to be dead and 111 patients without the family history died during 17,527 person-years, giving a relative risk of 1.26 (not significant). We focused on the male subjects that were followed up for more than 10 years; however, the observed/expected ratio of cancer deaths for subjects with a family history of cancer was about four times higher than that for those without family history. Since case-control studies on family history are vulnerable to biased recall and interchangeability of cases, more cohort studies like the present study should be conducted to assess the association of the family history of cancer.

Case-Control Studies↗

[A note on methods for estimating the number of patients in the nationwide epidemiological survey on intractable diseases].

To find the most adequate method for estimating the number of patients in nationwide epidemiological surveys of intractable diseases, we examined six existing methods using reported data on 13 selected diseases. Estimated numbers of patients by the methods, except for methods with theoretical inadequacy or other problems, were almost equal to each other. The simple method, by which the number of patients is estimated as the reported one divided by the response rate, is recommended.

Arterial Occlusive Diseases↗

A novel CD10-positive erythroid cell line, RM10, established from a patient with chronic myelogenous leukemia.

A novel erythroid cell line, RM10, was established from a long-term bone marrow culture of a patient with chronic myelogenous leukemia (CML). RM10 cells were positive for periodic acid Schiff (PAS), but negative for peroxidase and dual esterase. RM10 cells had la, pre B (CD10), myeloid (CD13, CD14, CD33) and erythroid (glycophorin A) markers, but had no other lymphoid, megakaryocytic, or mesenchymal cell markers. RM10 cells spontaneously synthesized hemoglobin, which was markedly enhanced with hemin. Isoelectric focusing of the cell lysates and northern blot analysis of the total cellular RNA revealed hemoglobin synthesis in the cells. Using 125I-labeled recombinant human erythropoietin (Epo), two classes of Epo receptors were demonstrated in the RM10 cells. However, Epo did affect neither growth nor erythroid differentiation of the cells. RM10 cells rapidly differentiated to monocytic cells in the presence of 12-0-tetradecanoylphorbol-13-acetate, and simultaneously expressed glycoprotein IIb/IIIa. RM10 cells had Philadelphia chromosome (Ph), and expressed p210bcr-abl using immunoprecipitation with anti-c-abl and anti-phosphotyrosine antibodies. These results indicate that the RM10 cells have the characteristics of multipotential hemopoietic cells originating from Ph-positive CML and that high affinity Epo receptor class is not a sufficient condition for Epo responsiveness.

Adult↗

[Studies on evaluation of risk factors of cancer by a large-scale cohort study newly organized in Japan--planning and pilot study].

A large-scale cohort study has been planned in cooperation of 22 epidemiologists in Japan since 1986. The objective of this new cohort aged more than 40, consisting the inhabitants throughout Japan is to evaluate risk factors of cancer already known and suspected agents in so rapidly changing society of Japan where age-sex contraction of population, disease pattern and lifestyle habits have remarkably changing for the last decades. The factors examined are not only social factors but also biological ones from blood, serum and other body fluids. At the same time serum bank of healthy inhabitants in Japan is established in this study.

Cohort Studies↗

Mortality of hematopoietic disorders and hair dye use among barbers.

A total of 8,316 barbers were followed up from 1976 to 1987 to examine the relations between hair dye use and deaths from hematopoietic disorders. The follow-up rate was about 95%. Three leukemia deaths and two malignant lymphoma deaths were observed in this cohort. The observed deaths were less than the expected number calculated from age- and sex-specific mortality of the general population in Japan (3.8 and 3.0, respectively). No deaths from aplastic anemia or the other hematopoietic disorders were observed.

Adult↗

Sociomedical factors affecting participation in screening program on cerebro- and cardio- vascular disease.

In 1984 the Public Health Bureau of Nagoya City began a new health check-up program to encourage citizens aged 40 years to have a medical examination. The rate of participation was 46.6% greater than that of the previous program; however, at about 16%, it was still low. From the survey in Moriyama Ward following results were suggested. Housewives and female part-time workers who had not had a health examination during the previous year showed participation rates of 32.7% and 42.4%, respectively. It would seem that the low rate of participation in the health examination program conducted in the metropolitan area by the municipal Public Health Bureau is due to the existence of many medical care facilities, and the fact that 64.6% of men and 52.6% of women had undergone a medical examination in the year preceding the program. Total screening rates became 69.7% in males and 66.0% in females. Participation rates of 32.7% and 42.4% were achieved by unemployed women and by women with part-time employment, respectively, who had no experience of screening in the previous year. Total screening rates were 63.7% for the unemployed women and 82.1% for the part-time women.

Cardiovascular Diseases↗

Serum concentration of beta-carotene and intake frequency of green-yellow vegetables among healthy inhabitants of Japan.

Serum levels of beta-carotene were measured among healthy inhabitants (671 males and 948 females) of 2 towns in Japan to determine the association between the levels and intake frequency of green-yellow vegetables. Those individuals who consumed green-yellow vegetables frequently showed higher levels of serum beta-carotene than those who ate them less often. The influences of alcohol drinking, smoking, obesity and age on serum beta-carotene levels were similarly observed for the 2 areas. The factors listed above were used for adjustment, giving a significant association between intake frequency of green-yellow vegetables and serum beta-carotene level. The proportion of the subjects who rarely consumed green-yellow vegetables was larger among smokers than among non-smokers. There was a large difference in serum beta-carotene levels between the 2 towns, which could not be explained by alcohol drinking and smoking. Women showed statistically significantly higher serum beta-carotene levels than men.

Adult↗

Nation-wide study of lethal mid-line granuloma in Japan: frequencies of wegener's granulomatosis, polymorphic reticulosis, malignant lymphoma and other related conditions.

Lethal mid-line granuloma (LMG) is a clinical term, and it is histologically composed of Wegener's granulomatosis (WG), polymorphic reticulosis (PR), and malignant lymphoma (ML). WG is an inflammatory disease, and PR and ML are considered to represent a neoplastic proliferation of lymphoreticular cells. In the present report, a nation-wide study on LMG in Japan is compared with a study from the UK, to examine differences in frequencies of each disease in Eastern and Western countries. A total of 340 cases of LMG were examined. On the basis of histological and clinical findings, these cases were categorized as 68 WG, 129 PR, 92 ML, 44 chronic inflammation not specified, and 7 other related conditions. The crude frequencies of WG, PR, and ML per 100,000 outpatients of ENT clinics in Japan and England were 4, 8 and 6, respectively and 8, 4 and I, respectively. The predominance of malignant lymphoproliferative diseases to WG in Japan (3.5:1) was in marked contrast to the situation in the UK (1:1.6). A review of the pertinent literature suggests a clustering of malignant lymphoproliferative diseases of the nose among Mongolian ethnic groups.

Adolescent↗

[Hazard ratio estimated from a proportional hazard model including two strongly correlated prognostic factors].

Estimates of hazard ratio from hypothetical survival data were examined, under the condition that the survival is affected by two prognostic factors X1 and X2 with two discrete values (0, 1) which are strongly correlated. Survival curves from the data were assumed to fit an exponential function. As an example, following numbers of subjects were used; 100 cases with X1 = 0 and X2 = 0, 10 cases with X1 = 1 and X2 = 0, 10 cases with X1 = 0 and X2 = 1, and 100 cases with X1 = 1 and X2 = 1. When the hazard ratio of X1 = 1 or X2 = 1 to X1 = 0 and X2 = 0 was 3, univariate analysis gave reasonable estimates around 3. Under the same condition, estimates of hazard ratio from multivariate analysis including the two variables X1 and X2 varied widely, depending on the survivals of 20 cases with X1 = 1 X2 = 0 or X1 = 0 X2 = 1. Probability of having extremely deviated estimates was demonstrated. The result illustrated successfully some points we should take into account when proportional hazard models including strongly correlated variables are applied.

Actuarial Analysis↗

Solubilization and characterization of erythropoietin receptor from transplantable mouse erythroblastic leukemic cells.

Functional erythropoietin (Ep) receptor (Ep-R) on transplantable mouse leukemic cells was solubilized by 3[(3-cholamidopropyl)dimethyl ammonio]-1-propanesulfate (CHAPS). An assay of the solubilized Ep-R was established: (1) radioiodinated Ep was bound to the solubilized Ep-R, (2) Ep.Ep-R complexes were covalently cross-linked, (3) the cross-linked products were selectively precipitated by polyethylene glycol, (4) the products were separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and (5) the Ep.Ep-R cross-linked products were measured. Optimal conditions to yield the cross-linked products and to stabilize the solubilized Ep-R were found. The solubilized Ep-R had properties similar to those of Ep-R on the membrane with respect to binding with Ep and the cross-linked products. These results would be exploited to allow purification of Ep-R.

Animals↗

[Explanatory essay for researchers who plan to analyse their clinical data using Cox's proportional hazard model].

Proportional hazard model was proposed by Cox as a multivariate model suitable for evaluation of prognostic factors and/or therapeutic effects. This paper aims at explaining fundamental concepts of the model for clinical researchers, as clear as possible. The relationship between hazard ratio and survival curves is demonstrated using an example of survivals calculated from an exponential function. Usage of computer programme SAS is described in brief for the readers who plan to analyse their own clinical data by this model.

Analysis of Variance↗

Determination of amino- and carboxyl-terminal sequences of guinea pig liver transglutaminase: evidence for amino-terminal processing.

Transglutaminases (EC 2.3.2.13) catalyze the formation of epsilon-(gamma-glutamyl)lysine cross-links and the substitution of a variety of primary amines for the gamma-carboxamide groups of protein-bound glutaminyl residues. These enzymes are involved in many biological phenomena. In this study, the amino- and carboxyl-terminal sequences of guinea pig liver transglutaminase were identified by sequence analysis to determine whether this enzyme is processed posttranslationally at its terminal regions. Two peptides, believed to contain the amino-terminal sequences of transglutaminase, were isolated from the Pronase digest of the enzyme protein with SP-Sephadex C-25 column chromatography and reverse-phase HPLC. Analyses (amino acid analysis, sequencing after the treatment with an acylamino-acid-releasing enzyme, and fast atom bombardment mass spectrometry) of these peptides indicated that the amino-terminal structure of this enzyme is acetylAla-Glu-Asp-Leu-Ile-Leu-Glu. The candidate for the carboxyl-terminal peptide in the trypsin digest of enzyme was isolated from the unadsorbed fraction of affinity chromatography with anhydrotrypsin agarose gel. The peptide was found to be Asn-Val-Ile-Ile-Gly-Pro-Ala. Both the terminal sequences were completely consistent with those predicted from the cDNA sequence [Ikura, K., Nasu, T., Yokota, H., Tsuchiya, Y., Sasaki, R., & Chiba, H. (1988) Biochemistry 27, 2898-2905]. These results indicated that the amino-terminal processing occurred after or in the course of translation of this enzyme, namely, removal of the initiator methionine and a subsequent acetylation of the alanine residue adjacent to the methionine. Our results did not indicate carboxyl-terminal processing of guinea pig liver transglutaminase.

Amino Acid Sequence↗

Influence of risk factors on long-term survival following acute myocardial infarction: a follow-up study in central Japan.

The long-term survival rate following acute myocardial infarction (AMI) was studied in 358 patients in central Japan who were monitored for 8 to 20 years after discharge from hospital for AMI. Fifteen-year cardiac survival rates were 65% in males and 72% in females. In both sexes, the survival rate decreased with increasing age at the time of AMI. The survival rate was significantly lower in recurrent MI than in first MI patients. Those who had smoked cigarettes before AMI or had hyperlipidemia during hospitalization did not show any significant decrease in cardiac survival rate, which may be due to cessation of smoking or control of hyperlipidemia after AMI. The 15-year survival rate was significantly lower in patients with a past history of angina pectoris or hypertension. Patients with a large infarct had a lower survival rate, as did those with a large cardiothoracic ratio on chest x-ray, and those who received digitalis during hospitalization. On the other hand, patients who were administered anticoagulants during hospitalization had a higher survival rate. Multiple regression analysis gave similar results. In conclusion, factors that reduced long-term survival rate after AMI were older age at time of the first attack, reduced cardiac function, and a history of angina pectoris or hypertension. Anticoagulant therapy appeared to improve the long-term survival rate.

Age Factors↗

Biochemical examination on the increased superoxide dismutase-like plasma substance observed in a state of acute gastric mucosal lesions.

When experimental acute gastric mucosal lesions were produced in guinea pig by water-immersion and restraint stress, superoxide dismutase (SOD)-like substance in the plasma increased. On analysis by gel filtration, it was shown that the molecular weight of the increased SOD-like plasma substance was about 130,000, and even after treatment with trypsin, 84% of this substance remained. Since the molecular weight of intracellular SOD is about 40,000, it seems that this substance is similar to extracellular SOD, located on the endothelial cell-surface, as previously reported by Marklund et al. Our results suggest that in the presence of acute gastric mucosal lesions, SOD-like plasma substance is not identical to intracellular SOD, which derived from cell destruction by stress or free radical-induced microvascular damage or by hemolysis. Furthermore, this substance may itself work as a scavenger of free radicals generated under conditions, such as these described in the present experiment.

Animals↗