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K Aoki

Publications and source records attributed to K Aoki.

At least 991 records · Page 55Linked to original sources
PubMed1975

[Bain's circuit].

Explore the source record for details and available documents.

Adolescent↗
PubMed1975

Limited hydrolysis of bovine plasma albumin at neutral and alkaline pH catalyzed by associated proteinases.

Proteinase contaminants in some plasma albumin samples have previously been shown to produce cleavage of the albumin molecule at acid pH. The F conformer, existing at pH 3.8, is cleaved near erisidue number 400 to yield a large N-terminal fragment of approximately 46,000 daltons. No cleavage was found at pH above approximately 4.4. It is shown in this paper that the proteinase contaminants are active over a broad pH range from 2.5 to 11.4 provided conditions are such as to induce some breakdown of the native conformation of the albumin molecule. Addition of Tris-borate buffer (0.1 M) at pH 7.5-9 is sufficient to permit cleavage. At pH near 9 this occurs predominantly 42,000 and 27,000 daltons. Near neutral pH substantial cleavage occurs in 4-8 M urea solution or in the presence of sodium dodecyl sulfate (AD110 complex). Under these conditions there are two large fragments (42,000 and 47,000 daltons) and essentially two small ones (20,000-27,000 daltons). Under conditions where there is no cleavage at 38-40 degrees, substantial cleavage results at 50-65 degrees but enzyme inactivation also occurs toward the top of this range. The alkaline activity is inhibited by soybean trypsin inhibitor but not by pepstatin; the reverse is true of the low pH activity. Cleavage at neutral or alkaline pH under the various conditions occurs primarily at X-Leu bonds while the low pH activity was already shown to occur at X-Phe. These facts suggest the presence of at least two enzymes. There is surprisingly little pH dependence over the range 7.5-9 in any of the media examined, even though albumin is known to undergo a significant conformational change in this range, the N leads to B transition. This transition is thought to be essentially a tertiary change with little loss of helix content. It is suggested that loss of native secondary structure, especially uncoiling of helical regions, is crucial to permit attack by these enzymes.

Amino Acid Sequence↗
PubMed1975

Hormonal status of breast cancer. II. Abnormal urinary steroid excretion.

The urinary excretion of 14 neutral steroids was measured by gas-liquid chromatography in women with early and advanced breast cancer, in women with early uterine cancer, and in healthy women from urban and rural districts. The premenopausal patients with early breast cancer excreted subnormal amounts of five steroids (11-hydroxyandrosterone, 11-hydroxyetiocholanolone, pregnanediol, pregnanetriol, and tetrahydrocorticosterone) and increased amounts of tetrahydrocortisol as compared with the normal subjects of corresponding ages. From our findings, a new parameter was proposed by which a premenopausal breast-cancer patient was separated from the control. Postmenopausal breast-cancer patients excreted greater amounts of five steroids (one steroid from 17-ketosteroids and four from 17-hydroxycorticoids) than the corresponding controls. The discrepancy between premenopausal and postmenopausal breast cancer was tentatively related to ovarian-adrenal dysfunction in the course of aging. Oophorectomy induced a long-lasting tumor regression only in patients with a high value for the ratio of 11-deoxy-17-ketosteroid to 17-hydroxycorticosteroid in urine taken before surgery; the ratio in the responsive patients decreased remarkably after surgery. A constitutional change in 17-ketosteroids, as observed in a postmenopausal breast-cancer patient and a premenopausal healthy woman of urban origin, favored the geographic importance in the genesis of breast malignancy. The steroid abnormalities in uterine cancer were distinguishable from those of breast cancer in both premenopausal and postmenopausal women.

11-Hydroxycorticosteroids↗
PubMed1975

Polymorphism of esterase D in some population groups in Japan.

Electrophoretic types of red cell esterase D (Es D) have been determined in more than 1,000 blood samples from Tokyo. The allele frequency for Es D2 was found to be 0.342. Typing was also carried out in samples of the Ainu of Hokkaido and of the Ryukyuans of the Okinawa Island: the Es D2 frequencies were found to be 0.273 and 0.369, respectively. These values are considerably higher than those described in Europeans, Negroes and even in Asiatic Indians. The results indicate that Es D with a marked degree of heterogeneity is a valuable marker for genetic, anthropological and forensic application in Mongoloid groups.

Asian People↗
PubMed1975

Serum dopamine-beta-hydroxylase activity in essential hypertension and in chronic renal failure with hypertension.

Elevated serum DBH (dopamine-beta-hydroxylase) activity was found in essential hypertension. The elevated level was not reduced when blood pressure was brought to normotensive level by administration of thiazide or rauwolfia. In contrast, serum DBH activity was low in both normotensive and hypertensive patients treated on prolonged hemodialysis. However, there was no correlation between serum DBH activity and blood pressure level. It was suggested that the pathogenesis of high blood pressure might be different between essential hypertension and hypertension with chronic renal failure, and that measurement of serum DBH activity might help for clinical differentiation of essential hypertension from certain forms of secondary hypertension.

Benzothiadiazines↗
PubMed1975

Stimulation of HeLa-S3 cell aggregation by sugars related to cell membrane in rotation culture.

Effect of various sugars related to cell membrane on the aggregation of HeLa-S3 cells was examined in a rotation culture by adding each sugar to the culture medium. Some specific sugars among those tested induced (1) greater size of aggregates and (2) higher synthesis of hyaluronic acid than that of the control. Since the addition of hyaluronidase inhibited the aggregate formation, both in the test and control cultures, with HeLa-S3 cells of both groups forming only small aggregates, it was presumed that the hyaluronic acid synthesized might be of cardinal importance for the formation of aggregates. The specific sugars producing the effect mentioned above were N-acetyl-D-glucosamine, bis(N-acetyl)chitobiose, N-acetyl-D-galactosamine, alpha-methyl-D-glucopyranoside, and N-acetyl-D-mannosamine, while D-glucosamine, beta-methyl-D-glucopyranoside, L-fucose, D-glucose, and a commercially available hyaluronic acid were ineffective. The findings obtained in the present study interestingly ran parallel with the results of previously reported study on the induction of specific biological phenomena by the cell membrane-related sugars.

Acetylgalactosamine↗