Search PubMed⌕ Search

Biomedical subjects

M Sakai

Publications and source records attributed to M Sakai.

At least 811 records · Page 45Linked to original sources
PubMed1981

beta-Galactosidase-neuraminidase deficiency in adults: deficiency of a freeze-labile neuraminidase in leukocytes and fibroblasts.

4-methylumbelliferyl neuraminidase activity was studied in fibroblasts, leukocytes, and frozen tissues from adult patients with beta-galactosidase-neuraminidase deficiency and specific clinical manifestations. This enzyme was almost completely deficient in fibroblasts, but the residual activity was relatively high (20% of the control mean) in the leukocytes from the patients. The frozen liver from one patient showed the enzyme activity as high as controls. This enzyme consisted of two components, freeze-labile and freeze-stable, and it was demonstrated that only the labile enzyme was deficient in fibroblasts and leukocytes. The apparently normal activity of neuraminidase in frozen autopsy tissues of a patient may be explained by the loss of the labile component in control tissues after a long-term freezing. The neuraminidase activity was variable in parents and no definite conclusion was drawn on the hereditary nature of the disease.

Brain↗
PubMed1981

Closely related mRNA sequences of protamines in rainbow trout testis.

Recombinant plasmids containing DNA complementary to protamine messenger RNA of rainbow trout (Salmo gairdnerii) have been isolated and sequenced. One of the clones contained the entire coding sequence of a protamine gene together with the complete 3' non-coding region. Another clone had an identical nucleotide sequence in the coding region but four base substitutions in the 3' non-coding region. On the basis of a comparison of the nucleotide sequences available at present, the structure and divergence of the protamine gene family are discussed.

Animals↗
PubMed1981

Construction and identification of a hybrid plasmid containing DNA sequence complementary to phenobarbital-inducible cytochrome P-450 messenger RNA from rat liver.

Cytochrome P-450 mRNA has been partially purified from membrane-bound polysomes of the livers of phenobarbital-treated rats by SDS-phenol-chloroform extraction, followed by poly(U)-Sepharose chromatography and by centrifugation through a sucrose density gradient. Cytochrome P-450 mRNA activity was detected near 18S in the sucrose density gradient, accounting for approximately 5% of total mRNA activity on the basis of [3H]leucine incorporation in an in vitro translation system of wheat germ. Complementary DNA (cDNA) which had been synthesized on the partially purified mRNA by AMV reverse transcriptase was inserted into the Pst I site of pBR 322. After bacterial transformation, and in situ colony hybridization using [32P]cDNA as a probe, a colony carrying cytochrome P-50 cDNA sequence was identified by a hybridization-arrested translation assay. Sequence complementarity of the inserted DNA sequence to cytochrome P-450 mRNA was further confirmed by a positive hybridization-translation assay. The mRNA isolated from the partially purified mRNA preparation by hybridizing it with the recombinant DNA (III-8-10) showed enriched synthesis of a protein product whose apparent molecular weight was consistent with that of cytochrome P-450, and which was immunoprecipitable with anti-cytochrome P-450 antibody.

Animals↗
PubMed1981

[Study on human pituitary gonadotropin synthesis and release during gestation by two steps LH-RF stimulation (author's transl)].

The pituitary gonadotropin response of synthesis and release to two step-stimulation at 60 minutes interval by 100 micrograms of luteinizing hormone-releasing factor was studied by radioimmunoassay of hLH-beta, hLH and hFSH in pregnant women. The immunological affinity of hLH-beta antiserum was 7.9% with hCG-beta, 3.4% with hLH-alpha and 0.41% with LER 907 as compared to 100% with hLH-beta. Serum mean levels of hLH in non pregnant women were 248.5 ng/ml serum before the first injection of LH-RF. The first injection caused an increase in the serum hLH level to 2185.0 ng/ml serum. After the second injection of the hormone, serum hLH levels increased further than the first peak, indicating the "self-stimulating" or "priming" effect of the first LH-RF on the second peak. Serum mean values of hLH-beta in normal menstrual women were 2.60 ng/ml before the first injection. The hLH-beta response to the second injection was significantly greater than to the first. The first peak of hLH-beta was 4.30 ng/ml serum and the second peak was 5.07 ng/ml serum. The FSH response to the second injection of LH-RF was not significantly peaked from that after the first injection. The value of the serum mean levels of hLH-beta during pregnancy were between 0.57 and 0.81 ng/ml and showed no significant increase through two LH-RF stimulations, suggesting that pituitary gonadotropins synthesis and release were depressed during gestation. Thus LH-RF two step stimulation was useful to clarify anterior pituitary function in both synthesis and release of gonadotropin.

Abortion, Spontaneous↗
PubMed1981

[Study on anterior-pituitary function during pregnancy and puerperium by radioimmunoassay of human FSH-subunits (author's transl)].

In order to observe the anterior pituitary function of pregnant women in terms of FSH secretion, specific and sensitive radioimmunoassays for human FSH-alpha and -beta subunits were utilized for this study. Blood levels of hFSH-alpha during pregnancy increase acutely and the values of the subunits are as follows: 428.0 +/- 92.64 ng/ml (mean +/- SE., 5-10 weeks of gestation), 962.8 +/- 132.5 ng/ml (11-20 weeks), 1889.0 +/- 137.60 ng/ml (21-30 weeks), 2959 +/- 323.40 ng/ml (31-40 weeks). After child delivery, serum levels of hFSH-alpha decreased to 22.92 ng/ml. In contrast, blood levels of hFSH-beta were not altered significantly through gestation. hFSH-beta subunits: 1.97 +/- 0.74 ng/ml (5-10 weeks of gestation), 2.66 +/- 0.52 ng/ml (11-20 weeks), 2.27 +/- 0.52 ng/ml (21-30 weeks), 2.07 +/- 0.37 ng/ml (31-40 weeks), respectively.

Adult↗
PubMed1980

Endoscopic evaluation of the effect of sucralfate therapy and other clinical parameters on the recurrence rate of gastric ulcers.

A randomized controlled clinical study was conducted to determine (a) whether basic aluminum sucrose sulfate (sucralfate) is effective in preventing or reducing gastric ulcer recurrence, and (b) the clinical parameters contributing to ulcer recurrence after endoscopically proved healing has been effected. A total of 167 patients were assigned on a random basis to either of two treatment groups, control (aluminum hydroxide and magnesium oxide) or sucralfate, and given these medications for 6 months. At the end of this period all medication was withdrawn from both groups and the patients were followed for an additional 12 months. Each patient was examined endoscopically at bimonthly intervals throughout the 18-month observation period. Treatment (sucralfate), ulcer history, size of previous ulcer(s), prestudy healing time, and prestudy healing stage attained (red or white scarring) were associated with a significant reduction in recurrence rate. Ulcer recurrence was markedly reduced in sucralfate patients as compared to control when the pretreatment ulcers had healed slowly (P less than 0.001).

Adult↗
PubMed1980

Topographical projections from the prefrontal cortex to the post-arcuate area in the rhesus monkey, studied by retrograde axonal transport of horseradish peroxidase.

The cells of origin of ipsilateral, prefrontal cortical projections to the post-arcuate area were studied in rhesus monkeys with the horseradish peroxidase (HRP) method. Following injections of HRP into the dorsal portion of the post-arcuate area, retrogradely labeled cells appeared in the arcuate area dorsal to the principal sulcus, while, following injections into its ventral portion, labeled cells appeared in the arcuate area ventral to the principal sulcus. They were pyramidal cells and lay mainly in the III layer, but small numbers of them were also found in the IV and V layers. In addition, HRP labeled cells were seen ipsilaterally in the banks of the cingulate sulcus.

Animals↗
PubMed1980

Importance of the carboxyl-terminal four amino acid residues in the inhibitory activity of Streptomyces subtilisin inhibitor (with a revision of its carboxyl-terminal sequence).

The carboxyl-terminal amino acid sequence of Streptomyces subtilisin inhibitor (SSI) was reinvestigated by analysis of the amino acid sequences of the thermolysin peptides from the C-terminal decapeptide, and the sequence -Val110-Ala-Phe-Phe113, which was reported in J. Biochem. 76, 1191-1209 (1974), was revised to -Val110-Phe-Ala-Phe113. Carboxypeptidase A digestion of SSI resulted in loss of the inhibitory activity in parallel with the release of the carboxyl-terminal four amino acid residues. The resulting modified inhibitor, des(Val110-Phe113)-SSI, possessed almost full inhibitory activity against subtilisin BPN' when the inhibitor was incubated with the enzyme in amounts less than one mol of enzyme per mol of the inhibitor. However, no inhibitor activity was observed when the molar ratio of the inhibitor to the enzyme was less than one. This phenomenon suggests that the carboxyl-terminal four amino acid residues might play an important role in the maintenance of the three-dimensional structure of SSI, which resists the action of the proteinase. The addition of more than 30-fold molar excess of SSI-(104-113)-decapeptide (C-terminal decapeptide of SSI) to the modified inhibitor resulted in refolding of the polypeptide chain, rendering it immune from proteolytic digestion.

Amino Acid Sequence↗