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Biomedical subjects

S Yuasa

Publications and source records attributed to S Yuasa.

At least 199 records · Page 11Linked to original sources

Age at any birth and breast cancer risk.

In an effort to assess the relative importance of age at first birth, age at subsequent births, and total parity to the occurrence of breast cancer, reproductive data from 4,225 women with breast cancer and 12,307 hospitalized women without breast cancer were analyzed by a multiple logistic regression model. Age at first birth was confirmed to be the most important reproductive risk indicator; it was associated with a 3.5% increase of relative risk for every year of increase in age at first birth (the 95% confidence interval of this estimate was 2.3 to 4.7% increase per year). However, age at any birth after the first was also an independent and statistically significant risk indicator; it was associated with a 0.9% increase of relative risk for every year of increase in age at any (and every) birth (the 95% confidence interval of this estimate was 0.4 to 1.5% increase per year). There is evidence that the age of approximately 35 years represents for every birth a critical point; before this age any full-term pregnancy confers some degree of protection; after this age any full-term pregnancy appears to be associated with increase in breast cancer risk. The effect of parity is determined by the age of occurrence of the component pregnancies. While most pregnancies occur under the age of 35, the distribution varies from population to population, and this may account for the differences between populations in whether or not a protective effect is seen for births after the first, and if it is seen, its extent.

Adolescent↗

Adrenoleukodystrophy-cerebello-brainstem dominant case.

A case of adrenoleukodystrophy was studied morphologically and biochemically. The patient was a 28-year-old man with no family history of adrenoleukodystrophy. His neurologic symptoms were cerebellar ataxia, spastic paraplegia, pseudo-bulbar palsy, and a minimal visual disturbance, with neither adrenal nor hypogonadal symptoms. The morphological and biochemical findings in this case are identical with those in typical adrenoleukodystrophy, but the topographical distribution of the lesions is distinctly different. The changes selectively affect the white matter in the cerebellum and brain stem in contrast to minimal involvement of the occipital white matter.

Adrenoleukodystrophy↗

Ranking of liver tests for differential diagnosis of liver parenchymal diseases.

Liver function tests were ranked in the order useful to differentiate 8 liver parenchymal diseases in combination of tests by forward selection and backward elimination procedures in the likelihood method using a microcomputer. The orders were almost same in both procedures: indocyanine green plasma disappearance rate, glutamic pyruvic transaminase (GPT), zinc turbidity test, alkaline phosphatase, age, HBsAg, RA test, glutamic oxaloacetic transaminase (GOT)/GPT ratio, GOT, cholesterol, total protein, total bilirubin, albumin/globulin ratio and gamma-globulin. The first 9 tests had almost all informations of all tests. The first likelihood diagnosis using the 9 tests was correct in 53% and the first or the second diagnosis was correct in 71% of 444 cases of 8 liver parenchymal diseases. A score table of likelihood diagnosis using the 9 tests was presented for manual application to new cases.

Clinical Enzyme Tests↗

Continuous synthesis of the dnaA gene product of Escherichia coli in the cell cycle.

The dnaA gene product of Escherichia coli, identified as a weakly basic protein of about 48,000 daltons (Yuasa and Sakakibara 1980), can be separated from other cellular proteins by means of two-dimensional gel electrophoresis. Synthesis of the dnaA protein took place continuously during a cell growth cycle. The newly synthesized dnaA protein persisted stably for one generation. Thermosensitive dnaA protein produced by the dnaA167 mutant was stable at 30 degrees C, but was disintegrated at 42 degrees C. The amount of intact dnaA protein present in the mutant exposed to the high temperature for 60 min was less than a quarter of the amount at the time of the shift. The cells having the reduced amount of intact dnaA protein were capable of initiating a new round of chromosome replication at the low temperature without de novo synthesis of the dnaA protein. The potential of the mutant for initiation of DNA replication decreased with reduction in the amount of the thermoreversible dnaA protein. The mutations dnaA167 and dnaA46 had no significant effect on the syntheses of the dnaA mRNA and the protein product at the low and high temperatures.

Bacterial Proteins↗

Differential diagnosis of liver parenchymal diseases by likelihood method using 12 laboratory data and age.

Liver parenchymal diseases were statistically diagnosed by likelihood method using 12 routine liver function tests and age. 444 cases of liver diseases were classified into 8 groups by histological diagnosis. A score diagnosis table was made from the data of these cases. For the likelihood diagnosis, data of each case were adapted to the score table and the probable diagnosis was calculated. Correct diagnosis rate of the first probable diagnosis was 50% in all cases and that of the first and the second was 71%. Descending order of the correct diagnosis rate of the first diagnosis was fatty liver (76%), liver cirrhosis (67%), slight histological changes (61%), acute hepatitis (51%), alcoholic liver injury (48%), chronic aggressive hepatitis 2A (43%), chronic persistent hepatitis (40%) and chronic aggressive hepatitis 2B (26%). In conclusion, differential diagnosis of liver parenchymal diseases was made easily with the score table of 13 informations with a considerable success.

Adult↗

[Plasma exchange therapy in colonic cancer with hepatic metastasis].

The plasma exchange using Carcino embryonic Antigen (CEA) value as an index was performed for 3 colonic cancer patients with liver metastasis. A remarkable regression of hepatomegaly in two cases with rectal cancer was obtained and a significant decrease of CEA was observed in all patients.

Aged↗

Identification of the dnaA and dnaN gene products of Escherichia coli.

A specialized transducing lambda phage carrying the dnaN genes of Escherichia coli specifies two proteins of about 41 and 48 kilodaltons (kd). The temperature-sensitive mutations, dnaN59 and dnaA167, were found to result in altered isoelectric points of the 41 and 48 kd proteins, respectively. Thus the dnaN gene product was identified as a weakly acidic 41 and 48 kd protein. The synthesis of the dnaN gene product is greatly reduced by insertion of a transposon Tn3 in the dnaA gene and by deletion in the gene at the distal end to the dnaN gene. Temperature-sensitive dnaA mutations, on the dnaN gene product. These results indicate that the synthesis of the dnaN gene product is dependent on the structural integrity of the dnaA gene.

Bacterial Proteins↗

Maternal age and birth rank of women with breast cancer.

Data from a large international case-control study of breast cancer suggested that women born to young mothers had a 25% lower risk of breast cancer. The association was not secondary to a tendency for these women themselves to have had children at early ages. The data provided no indication of a meaningful association between breast cancer risk and birth rank. Confounding was controlled by stratification according to a summary confounder score.

Adult↗

Interaction of calcium and microtubules in the action of cyclic AMP on the toad urinary bladder.

Involvement of microtubules in the cellular action of vasopressin was studied by physiological and biochemical procedures. The inhibitory effect of 10(-4) M colchicine on the hydro-osmotic response of the toad bladder to 2 mM cyclic AMP was completely blocked by an increase in the concentration of calcium in the serosal bathing medium from 1 to 8 mM. Most of the colchicine-binding activity of extracts of the bladder epithelial cells was recovered by DEAE-Sephadex chromatography in a procedure similar to that used to isolate tubulin of bovine brain. Sodium dodecyl sulfate urea and urea gel electrophoresis of the DEAE-Sephadex fraction from the bladder epithelial cells yielded bands that corresponded to those of bovine brain tubulin. When 8 mM CaCl2 was present in an incubation mixture, the binding of colchicine to tubulin from the bladder epithelial cells and bovine brain was significantly inhibited. However, 1 mM CaCl2 did not affect the binding of colchicine to tubulin. Although the present study supports the concept that microtubules and calcium play an important role in the cellular action of vasopressin on the toad urinary bladder, the mechanism by which calcium blocks the inhibitory effect of colchicine on the hydro-osmotic response to cyclic AMP could not be elucidated.

Animals↗