PubMed Health⌕ Search

Biomedical subjects

S Mizukami

Publications and source records attributed to S Mizukami.

At least 73 records · Page 4Linked to original sources
PubMed1983

Sexual difference in nuclear volume and its ontogeny in the rat amygdala.

Nuclear volume of the medial and lateral nuclei of the amygdala was investigated in male and female rats. The volume of the medial nucleus in the adult male rat was significantly greater than that of the female rat. Treatment of female rats with estrogen for the first 30 days of postnatal life increased the nuclear size, and the volume became comparable to that of the males. Although there was no significant difference in volume of this nucleus between male and female rats from days 1 (day of birth) to 11, the difference became evident at day 21, and thereafter it persisted. In contrast, the nuclear volume of the lateral nucleus was not different between the two sexes. Estrogen treatment did not influence the volume of the lateral nucleus in the female animals. These data indicate that the nuclear volume is sexually different in the medial nucleus of the amygdala, and its differentiation occurs during the early postnatal period under the influence of the organizational action of sex steroids.

Amygdala↗
PubMed1982

Failure of ovulation after neonatal administration of 5 alpha-dihydrotestosterone to female rats.

Wistar female rats were injected with testosterone (T) or 5 alpha-dihydrotestosterone (5 alpha-DHT) from the day of birth (= day 1) to day 5. Neonatal treatment with 1 mg of T resulted in anovulatory persistent estrous syndrome in 100% of the animals. In the females treated with 1 mg of 5 alpha-DHT, 88.2% of the treated rats were sterile at 120 days of age. Treatment with 0.5 mg 5 alpha-DHT was also effective in inducing anovulatory sterility, the incidence of sterility being 71.4%. In the females injected with 0.1 mg 5 alpha-DHT, 42.9% of the animals were anovulatory at 120 days of age. These results suggest that non-aromatizable androgen, 5 alpha-DHT, can permanently suppress the development of female type of neuroendocrine regulation.

Animals↗
PubMed1981

Induction of anovulatory sterility by neonatal treatment with 5 beta-dihydrotestosterone in female rats.

Wistar female rats were injected with testosterone (T) or 5 beta-dihydrotestosterone (5 beta-DHT) for the first 5 days of life. Neonatal treatment with 1 mg of T resulted in anovulatory persistent oestrous syndrome in 100% of the animals. In the females injected with 1 mg of 5 beta-DHT, 74% of the treated rats became sterile at 120 days of age. In addition, 0.5 mg 5 beta-DHT was also effective in inducing anovulatory persistent oestrus; the incidence of sterility was 10 and 80% at 60 and 120 days of age, respectively. When daily dose of 5 beta-DHT was reduced to 0.1 mg, however, only 33% of the rats resulted in sterility. These results suggest that the free form of T and non-aromatizable androgen, 5 beta-DHT, can permanently suppress the development of female type of neuroendocrine regulation. The possible participation of the process other than the central aromatization in androgenization will be discussed.

Animals↗
PubMed1977

Fusion of dissociated fish embryonic cells.

The induction of a frequent fusion in dissociated fish embryonic cells is reported. Fusion was induced during mechanical isolation of blastomeres in normal saline solution or Ca2+-free saline solution by quickly bringing about physical contact between cells within about 1-5 min of dissociation. Fused blastomeres were obtained in about 18% yield from early morula cells in about 68% yield from early blastula cells and in about 5% yield from early gastrula cells.

Animals↗
PubMed1975

[Biphasic (ulcer-forming and ulcer-preventing) effect of adrenaline in rats].

Adrenaline-induced gastric ulceration was studied in rats. Adrenaline in high doses caused gastric ulcer, which was completely blocked by pretreatment with alpha-blockers (phenoxybenzamine, dibenamine), but not by pretreatment with propranolol or atropine, nor by vagotomy, hypophysectomy or adrenalectomy. After successive administration of adrenaline, once daily for 7 days, however, no gastric ulcer was observed. Recovery from the ulcerogenic action of adrenaline was seen after 4 weeks withdrawal. Pretreatment with a small dose of adrenaline inhibited the ulcerogenic action of a high dose of adrenaline. Pretreatment with reserpine, pyrogallol or iproniazid inhibited the action of adrenaline. It is concluded that adrenaline has a biphasic effect on gastric ulceration, the ulcerogenic action is due to its alpha-action and antiulcerogenic effect is due to development of tachyphylaxis.

Adrenalectomy↗
PubMedDate not supplied

[Cryopreservation of bone marrow and peripheral blood stem cells using a controlled rate freezing system: experience with 86 procedures].

UNLABELLED: The cryopreservation of hematopoietic stem cells can be used for rescuing the hematopoiesis after high dose chemotherapy. PURPOSE: The ice crystal formation during the freezing procedure is the key point that can be harmful to the cells. The cryopreservation of hematopoietic stem cells in a controlled-rate freezer could decrease the cell damage. METHODS: Twenty-three patients with a median age of 26 years (range 03-57) had bone marrow and/or peripheral blood stem cells harvested from March 1993 through October 1994, ending up to 86 freezing procedures. The patient's diagnoses are as follows: Non-Hodgkin's Lymphoma (n = 5); Acute Myelogenous Leukemia (n = 8); Acute Lymphocytic Leukemia (n = 6); Hodgkin's disease (n = 3); Multiple Myeloma (n = 1). The cells were frozen away in a controlled-rate freezer chamber at the following rate: -1 degree C/min from room temperature to -45 degrees C and then, at -10 degrees C/min down to -80 degrees C. After freezing, the cells were kept into mechanical freezers until the marrow infusion. To mobilize PBSC (peripheral blood stem cells), G-CSF (granulocyte colony stimulating factor) was given. RESULTS: A median of 3.16 x 10(8) cells/kg (range 0.86-24.22) of PBSC and 2.03 x 10(8) cells/kg (0.19-12.21) of bone marrow cells were frozen. The median time to reach granulocytes greater than 500/microL and platelets greater than 20,000/microL was 12 days (range 8-40) and 31 days (range 8-80), respectively. All patients had marrow engraftment after infusion of hematopoietic stem cells. CONCLUSION: The cryopreservation procedure using a controlled-rate freezer can store hematopoietic stem cells and potentially, cause less damage to the cells.

Adolescent↗
PubMedDate not supplied

Diverse biological activities of moxa extract and smoke.

Diverse biological activities of moxa extracts and smoke (gas phase) were investigated. Moxa was extracted with hot water (Fr. I), or ethanol (Fr. II), or extracted with hot water after ethanol wash (Fr. III) and then lyophilized to obtain the dried powders. Moxa smoke (containing a lot of gaseous components obtained by burning Moxa) (Fr. IV) was collected into phosphate-buffered saline and quantified spectrophotometrically. These extracts and Moxa smoke showed comparable cytotoxic activity against human oral tumor cell lines (HSC-2, HSG). Human gingival fibroblasts (HGF) were more resistant to any Moxa fractions. Neither of the extracts showed anti-HIV activity. Pretreatment of mice with Fr. I significantly reduced the lethal effect of E. coli infection. All extracts produced radicals under alkaline condition, with a maximum intensity at pH 10.5, and enhanced the radical intensity of sodium ascorbate. It was unexpected that these extracts show significant O2- scavenging activities. These data suggest the medicinal efficacy of Moxa extracts and smoke.

Animals↗