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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 1,693 records · Page 94Linked to original sources
PubMed1976

Effect of dibutyryl cyclic AMP on neuromuscular transmission in myasthenia gravis.

The effect of dibutyryl 3',5'-cyclic monophosphate (D-cAMP) on the neuromuscular transmission was studied in a patient with myasthenia gravis during anesthesia. D-cAMP caused a slight increase in single twitch tension, and an initial transient decrease in tension which resulted from the trains of 2 Hz stimuli disappeared after D-cAMP. The finding of the present study suggests that D-cAMP has an anti-fatigue effect in patients with myasthenia gravis.

Adult↗
PubMed1976

Changes in the weight of the adrenal glands and in the concentration of plasma corticosterone in perinatal rats after prenatal treatment with oestadiol benzoate.

On day 20 of gestation, foetal rats received a subcutaneous injection of 0-01 mg oestradiol benzoate dissolved in 0-05 ml sesame oil; foetuses in other litters were given sesame oil alone. Autopsy was performed on day 22 of gestation, at delivery or at various times after birth. Gravimetric and histological observations of the adrenals from oestradiol-treated, oil-treated and intact litter-mate control foetal and neonatal rats were performed together with determination of plasma corticosterone concentrations. Activity of 3 phi-ol dehydrogenase was also examined histochemically in the adrenals from these animals. The results indicated that oestradiol benzoate when given prenatally prevented the neonatal decline of adrenal weight and adrenocortical cell size. In normal or oil-treated rats, plasma corticosterone concentration was greatly increased during delivery and 2 h after birth, declining up to 12 h after birth. Oestradiol benzoate prevented this perinatal increase and suppressed the activity of 3 phi-ol dehydrogenase in the perinatal adrenal cortices.

Adrenal Glands↗
PubMed1976

Effects of early cyclophosphamide treatment on lymphoid organs and its immune response in ducks.

Cyclophosphamide treatment of newly hatched White Pekin ducks significantly reduced the weight of their lymphoid organs and almost completely eliminated the formation of bursal lymphoid follicles at one week of age. There after the thymus and spleen of these ducks completely recovered in weight at 7 weeks of age. The bursa, however, retained its light weight and morphological defects, such as the absence of lymphoid follicles. The specific antibody producing-capability to Salmonella pullorum was also eliminated. The total dosage of cyclophosphamide was smaller than that employed in chickens, which makes effective chemical bursectomy in ducks possible.

Animals↗
PubMed1976

Carcinogenicity of N-nitrosamines related to N-butyl-N-(4-hydroxybutyl)nitrosamine and N,N,-dibutylnitrosamine in ACI/N rats.

Carcinogenic effect of 14 N-nitrosamines related to N-butyl-N-(4-hydroxybutyl(nitrosamine (BBN) and N,N-dibutylnitrosamine (DBN) was studied in ACI/N male rats by administration in the drinking water. BBN homologs having methyl, ethyl, or pentyl group selectively induced urinary bladder tumors, but a homolog with tert-butyl group did not have any carcinogenic effect. N-Ethyl-N-(3-carboxypropyl)nitrosamine, the principal urinary metabolite of the ethyl homolog of BBN, did also induce bladder tumors selectively, thus providing an additional evidence that N-alkyl-N-(3-carboxypropyl)nitrosamines are responsible for the selective induction of bladder tumors by BBN homologs. N-Butyl-N-(carboxymethyl)nitrosamine and BBN analogs having 3-hydroxypropyl chain together with ethyl or butyl group were found to be noncarcinogenic. N-Propyl-N-butylnitrosamine and DBN induced hepatomas, but simultaneous development of esophageal tumors were observed only with the former. N-Butyl-N-(3-hydroxybutyl)nitrosamine, one of the principal metabolities of DNB, did not induce any tumors, but its further transformation product, N-butyl-N-(3-oxobutyl)nitrosamine as well as N-butyl-N-(2-oxobutyl)nitrosamine, another metabolic intermediate of DBN, induced hepatomas. Possible correlation of structure and metabolism with organotropic carcinogenesis by N-N-dialkylnitrosamines is discussed, with special reference to selective induction of urinary bladder tumors.

Alanine Transaminase↗
PubMed1976

Induction of transplantation immunity by dansylated tumor cells.

Tumor cells were coupled with fluorecent dansyl group in aqueous medium by dansyl chloride-cycloheptaamylose complex (CDC) without destruction of the cells. C57BL/6 mice and Donryu rats pretreated respectively with dansylated EL4 leukemia cells and with dansylated Yoshida sarcoma cells acquired transplantation immunity to the corresponding tumor cells. Serum and spleen cells obtained from EL4 immune mice showed cytotoxicity to EL4 cells but not to other allogeneic leukemia cells. Hapten-specific cytotoxicity of immune serum and spleen cells was not observed in the present immune system.

Animals↗
PubMed1975

Ultrastructure of the thread cells in the slime gland of Japanese hagfishes, Paramyxine atami and Eptatretus burgeri.

The thread cells in the slime gland of Japanese hagfishes, Paramyxine atami and Eptatretus burgeri were studied by light and electron microscopy. The mature thread cells are large elements (180 times 80 mu) filled with an intricately coiled thread, approximately 2 mu in diameter. The protein nature of the thread has been confirmed by histochemical examination. In the initial stage of growth, the thread consists of a bundle of distinctly parallel filaments approximately 90-120 A in diameter and a centrally located tubular component approximately 230-260 A in diameter which occurs singly or occasionally as a double and triple structure. The developing thread displays thin filaments, approximately 30-60 A in diameter. The thin filaments are composed of fine fibrous structures, subfilaments, approximately 10-30 A in diameter. On the outer surface of the thread a coating is apparent, giving it a fluffy appearance. Polysomal clusters consisting of five or six ribosomes are predominant. Fine fibrous structures are also found among the threads; they seem to have a spatial relationship with the polysomes and resemble the subfilament constituents of the thin filaments. From these results, it may be suggested that the fine fibrous structures synthesized by polysomes, twist together and coalesce into a thread. The problem of the polysome size and the molecular weight of the fibrous protein synthesized is discussed.

Animals↗
PubMed1975

Granular cells in the juxtaglomerular apparatus in perinatal rats.

Granular cell indices (GCI; Dunihue and Robertson, '57) in kidneys of fetal and newborn rats were determined by examining sections stained with Bowie's technique. Some fetuses were delivered prematurely by Caesarean section a day earlier than the expected delivery, and were then nursed by a foster mother. Similarly, postmature Caesarean newborn rats were obtained; retention one day beyond the normal gestation was induced by maternal progesterone injections. The GCI was strikingly increased within a day after birth, followed by an immediate decrease therafter. This was also observed in both premature and postmature rats. It seems that this temporary increase of the GCI is not attributable solely to the age of rat, but follows only the separation from the maternal environment.

Animals↗
PubMed1975

Evaluation of linear gastric ulcer as a precancerous lesion.

During the recent 13 years from 1961 to 1973, 21 cases of ulcer-carcinoma satisfying Hauser's pathologic criteria have been found endoscopically, 5 cases (2.6%) of which were mucosal carcinoma accompanying linear ulcer over 30 min in length. In addition, one submucosal carcinoma and 2 cases of sub-early gastric carcinoma, partially invaded into the proper muscle layer, were used for this study. Using these 8 cases and 11 operated ones of benign linear ulcer, we have a comprehensive study of histologic and clinical findings of both groups. As the results, malignant linear ulcer was similar in condition to the benign, either in mother ground or in histologic and clinical findings. Moreover, coexistent carcinoma with all kinds of gastric ulcer and with linear ulcer among them was found in 1.5% and 3.8%, respectively. In a series of controlled group, early gastric carcinoma was found in 2.1% out of 284 cases of no ulcer scar from its follow-up study. Its x2 test revealed no significant difference among these values. However, we might conclude that endoscopical follow-up study of chronic gastric ulcer, especially long linear ulcer, is indispensable for understanding the evaluation of malignant change of ch ronic gastric ulcer.

Adult↗
PubMed1975

Pharmacokinetics of lincomycin and clindamycin phosphate in a canine model.

Linomycin and clindamycin phosphate were studed in a canine model in which acute biliary obstruction was produced during iv infusion of antibiotic. Hepatic and renal extraction, bilary and renal excretion, and concentrations in liver and kidney were measured. Total and nonesterified clindamycin were assayed. The antibiotics were taken up by the liver at similar rates; however; the rates of excretion and concentration in bile were significantly higher for lincomycin than for clindamycin. Biliary obstruction did not affect the concentration of either antibiotic in canalicular bile. Lincomycin was extracted by the kidneys and excreted into urine at a much higher rate than was clindamycin. Concentrations of nonesterified clindamycin in the hepatic vein were higher than those in the portal vein, an observation suggesting metabolic activation within the liver. This relation was reversed by bilary obstructon. The results in this canine model indicate a greater role for the kedney in the disposition of lincomycin than in that of clindamycin, major differences between the rates of biliary excretion of the two agents, and a probable change in the metabolism of clindamycin procued by acute bilary obstruction.

Animals↗
PubMed1975

Fc-rosette inhibition by hypocomplementaemic systemic lupus erythematosus sera.

Human red cells sensitized with one of the Rh antisera (Ripley) form rosettes (Fc-rosette) with human B lymphocytes and the rosettes are well inhibited by aggregated human IgG. Since sera of hypocomplementaemic patients with systemic lupus erythematosus (SLE) have frequently been reported to contain immune complexes, they were used for the inhibition of Fc-rosette formation in this study. The results of Fc-rosette inhibition rates of the sera were inversely correlated with the serum CH50 levels. When the sera were separated into top, middle, and bottom fractions by ultracentrifugation, the bottom fractions showed more effective inhititions than the others. Similarly, the strongest inhibition was found in the void volume of the serum separated by Sephadex G200 gel filtration. Reduction and alkylation of IgG resulted in the loss of reactivity with Fc receptor of B lymphocytes, and the rosette inhibiting activities of the SLE sera were markedly reduced after reduction and alkylation. Some of anti-HLA sera were inhibitory for the Fc-rosette formation, while the tested sera did not contain anti-HLA activity assessed by the microcytotoxicity test. These results indicated that circulating immune complexes contained in the sera inhibit the rosette formation, and that the Fc-rosette inhibition test is a simple and relatively sensitive method for the detection of circulating immune complexes. Antinuclear antibody activities of the sera were tested by the indirect immunofluorescent method; however, clear correlations were not obtained between Fc-rosette inhibition rates and staining patterns of antinuclear antibodies. On the other hand, the positive groups of LE-test exhibited slightly greater inhibition rates of the rosette than the negative groups.

Antibodies, Antinuclear↗