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Biomedical subjects

T Sekiguchi

Publications and source records attributed to T Sekiguchi.

At least 217 records · Page 12Linked to original sources
PubMed1982

Suppression of tumorigenicity in interspecific reconstituted cells and cybrids.

The effect of cytoplasms on the expression of tumorigenicity was examined in interspecific reconstituted cells and cytoplasmic hybrids (cybrids) formed by fusions between karyoplasts (or intact cells) from highly tumorigenic mouse melanoma B16 cells and cytoplasts from non-tumorigenic, hypoxanthine-guanine phosphoribosyl-transferase (HGPRT)-deficient and chloramphenicol (CAP)-resistant rat myoblastic cells, L6TG X CAPr. The reconstituted clones and cybrid clones isolated in the double selection medium, HAT and CAP, acquired CAP-resistance, and each showed unique morphology and cellular arrangement. Tumorigenicity was suppressed in all the reconstituted clones and cybrid clones examined at an early stage after their isolation, but re-appeared in some clones after prolonged cultivation of the cells.

Animals↗
PubMed1981

Purification of cytoplasts (enucleated cells) and karyoplasts (nuclei) from mouse splenic lymphocytes with cytochalasin-B.

Murine spleen and lymphoma cells were almost completely enucleated in suspension by centrifugation in discontinuous Ficoll gradients in the presence of cytochalasin-B. Viability of cytoplasts (cells lacking nuclei) and karyoplasts (nuclei) was over 90%. Pure fractions of cytoplasts or karyoplasts were then obtained by fractionation of the cytochalasin-B treated cells with unit gravity sedimentation in bovine serum albumin. Protein synthesis was seen in cytoplasts when they were stimulated with mitogens, such as lipopolysaccharide (LPS). This method can consistently yield pure fractions of morphologically and functionally intact karyoplasts or cytoplasts from normal lymphocytes with very low contamination of nucleated cells. Pure karyoplasts or cytoplasts obtained in this way could be extremely useful for subcellular analysis of lymphocyte activation.

Animals↗
PubMed1981

[Clinical experience with cefoxitin in bacterial infections of children (author's transl)].

Using a new cephamycin antibiotic, cefoxitin, clinical studies were carried out, and the following results were obtained: (1) Cefoxitin was administered to 52 children with 38 respiratory tract infections, 2 urinary tract infections, 1 acute otitis media and others, who ranged in age from 2 months to 11 years old. (2) Cefoxitin was given intravenously at a daily dose of 27.3 mg/kg to 110.5 mg/kg. (3) The overall efficacy rate was 80% in 46 cases, i.e., excellent in 10, good in 27, fair in 7 and poor in 2. (4) Clinical side effects were not seen except exanthema in 1 patient. Elevation of GOT and GPT was seen in 2 patients, elevation of A1-P in 1 and eosinophilia in 2 by laboratory tests. However, these findings were alleviated rapidly following the cessation of therapy.

Age Factors↗
PubMed1981

[Clinical experience with cefroxadine in bacterial infection of children (author's transl)].

In order to evaluate effectiveness of cefroxadine (CXD) in the treatment of bacterial infections of children, the clinical studies were carried out. CXD was orally administered to 30 patients at daily dose of 27.5 approximately 50.0 mg/kg (average 32.3 mg/kg) in 3 approximately 4 divided dose for 3 approximately 10 days (average 4.9 days). The overall efficacy rate in 30 cases was 93.3%, i.e., excellent 22 (73.3%), good in 6 (20.0%), fair in 1 (3.3%) and poor in 1 case (3.3%). Drug eruption and transient eosinophilia were observed in 1 case each out of 30 cases (6.7%), but any other abnormality was not observed throughout this series. Based on the above results, CXD was thus considered to be a useful antibiotic in treatment of pediatric infections.

Bacterial Infections↗
PubMed1980

Evaluation of the time weighted average of air contaminants with special references to concentration fluctuation and biological half time.

Statistical parameters with carbon felt dosimetry are analyzed and new sampling criteria are presented based on the analysis. In cass where the mean of measured time-weighted averages is kept two times the unbiased standard deviation below the maximum permissible concentration-time weighted average (MPC-TWA) and the values above MPC-TWA are observed with a frequency of less than 5%, compliance is determined with a confidence limit of 95% provided the biological half time of the contaminant is longer than 4 hours.

Air Pollutants↗
PubMed1980

Mechanism of gastroesophageal reflux in recumbent asymptomatic human subjects.

We investigated the mechanism of gastroesophageal reflux (GER) in 10 health volunteer subjects. Continuous recordings of intraluminal esophageal pH and pressure were obtained on two consecutive nights from 6:00 p.m. to 6:30 a.m. in each subject. During each study, the subject remained recumbent, except to eat a standardized meal after 1 h of basal recording. A manometric assembly with seven recording lumens monitored: (a) lower esophageal sphincter (LES) pressure via a sleeve device 6.5 cm in length, (b) esophageal-body motor activity, (c) swallowing activity in the pharynx, and (d) gastric pressure. An electrode 5 cm above the LES recorded esophageal pH. Sleep was monitored by electroencephalogram. All subjects showed wide variations of basal LES pressure. GER was not related to low steady-state basal LES pressure, but rather occurred during transient 5-30 s episodes of inappropriate complete LES relaxation. The inappropriate LES relaxations were usually either spontaneous or immediately followed appropriate sphincter relaxation induced by swallowing. The majority of GER episodes occurred within the first 3 h after eating. During the night LES relaxation and GER occurred only during transient arousals from sleep or when the subjects were fully awake, but not during stable sleep. After GER the esophagus was generally cleared of refluxed acid by primary peristalsis and less frequently by secondary peristalsis. Nonperistaltic contractions were less effective than peristalsis for clearing acid from the esophagus. We conclude that in asymptomatic recumbent subjects GER is related to transient inappropriate LES relaxations rather than to low steady-state basal LES pressure and also, that primary perstalsis is the major mechanism that clears the esophagus of refluxed material.

Adult↗
PubMed1980

Comparison of effects of external Ca2+ on antioxytocin actions of antispasmodics in ovariectomized and estradiol-treated rat uteri.

The influence of Ca2+ on the antioxytocin actions of papaverine, deoxycholate and 1,1-diphenyl-3-piperidinobutanol hydrochloride (Aspaminol) was investigated in the ovariectomized and the estradiol-treated rat uteri, and Ca exchangeability and Ca content in both uteri were compared. No qualitative difference in the responses to deoxycholate and Aspaminol at normal and higher Ca2+ concentrations in the estradiol-treated rat uterus was seen as compared to those obtained from the ovariectomized one. The antioxytocin action of papaverine in the estrogenized uterus was antagonized by excess external Ca2+, but not in the ovariectomized one. There were no significant differences either in the total Ca content or the non-displaceable Ca by La between the ovariectomized and the estrogenized rat uterine longitudinal muscle layers, while Ca exchangeability in the estrogenized was much greater than that in the ovariectomized one. These results suggest that the antagonism of papaverine against exogenous Ca2+ may be related to the more increased Ca exchangeability in the estradiol-treated rat myometrium.

Animals↗