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Biomedical subjects

S Sakuma

Publications and source records attributed to S Sakuma.

At least 343 records · Page 19Linked to original sources
PubMed1984

The relationship between serum hormone levels and reproductive ability in aging male rats.

The relation between fertility and hormonal levels was studied in aging male rats. Reproductive ability was inspected at 30, 31, 59, 60, 93 and 94 weeks of age, and the serum hormone levels were determined by the radioimmunoassay. Reproductive ability decreased with aging (mating rates: 15/20, 11/20, 3/20 and 6/20 at 30, 31, 59 and 60 weeks, respectively) and no male mated at 93 and 94 weeks. Serum testosterone levels in males without reproductive activity were significantly lower than those in males with reproductive activity. LH and FSH showed the lowest level in 95 weeks. The highest value of LH was found at 60 weeks in males without reproductive activity having low testosterone levels. The highest value of prolactin appeared in 95 weeks which was three times higher than those in the other groups. The results suggest that the loss in the reproductive activity in aging rats starts with a decrease in libido, which is followed by a high gonadotropin and low testosterone condition, and accomplished under a low gonadotropin and high prolactin circumstance.

Aging↗
PubMed1984

A histometrical study of immunohistochemically identified mitotic adenohypophysial cells in immature and mature castrated rats.

Two weeks after operation the effects of castration on all types of mitotic adenohypophysial cells in 30-day-old (immature) and 75-day-old (mature) male rats were studied immunohistochemically by light microscopy. The total number of mitotic cells in gland specimens increased 1.4 times in immature rats, but remained unchanged in mature animals; mitotic activity (mitotic cell number/mm2) was not affected in either age group. The population of mitotic gonadotrophs increased five to six times in comparison with intact controls. In addition, the percentage of mitotic gonadotrophs and their mitotic activity were raised in both age groups. Castration affected the mitosis of prolactin cells. The percentage of mitotic prolactin cells was reduced by one-third in castrated immature rats, but the total number and percentage of mitotic prolactin cells, as well as their mitotic activity, was reduced by about two-thirds in mature castrated rats. No significant changes in mitotic ACTH, TSH, GH and immunonegative cells were found after castration in either group of animals. Mitotic cells were more numerous in the anterior than in the posterior region of the gland in normal (uncastrated) immature rats, but were uniformly scattered in both regions in normal mature rats. On the other hand, castration induced a high population of mitotic cells in the anterior region regardless of age. This high population was the result of the enhanced mitosis of gonadotrophs. It is concluded that 2 weeks after castration the increment of mitotic divisions of all types of pituitary cells is age-dependent, and that mitosis takes place frequently in gonadotrophs and less frequently in prolactin cells.

Adrenocorticotropic Hormone↗
PubMed1984

Evaluation of varicella vaccine in childhood leukemia. Observation over 6 years.

Since 1977, we have used a live attenuated varicella vaccine to immunize 10 children with acute leukemia. 8 patients had no adverse clinical reaction but 2 patients developed mild fever and papulovesicular rash after vaccination. All 9 tested children became seropositive after the vaccination. Also in all 3 children who were observed for more than 4 years, persistence of neutralizing antibody was detected. Most of the recipients were prevented from developing symptoms of varicella in spite of contact exposure. Two patients developed varicella when they were in severe immunosuppressive states but their symptoms were mild. None of the children developed herpes-zoster during the 6 year follow-up period. The results suggest that the varicella vaccine is effective in children with acute leukemia, and that long-term effectiveness can be expected.

Antibodies, Viral↗
PubMed1984

Postoperative irradiation after reconstructive surgery: comparative study of radiosensitivity between free-skin grafts and skin flaps.

Radiation effects after reconstructive surgery (free-skin grafts and skin flaps) were studied in the rat, and the optimum time for irradiation was determined. The radiosensitivity of both free-skin grafts and skin flaps showed the same trend depending on time of irradiation after operation. The grafts or flaps irradiated in the hypervascular stage showed severe reactions to irradiation, whereas those irradiated in the hypovascular stage showed milder reactions in gross and microangiographic observation. Vascular damage should be given primary consideration when deciding the proper time for irradiation after reconstructive surgery. In general, free-skin grafts showed more severe reactions than skin flaps, especially in the grafts irradiated in the early stage after operation. The experimental results of this study cannot be readily transferred to a clinical setting, but they suggest that postoperative irradiation could be begun 3 to 4 weeks after operation with respect to graft or flap survival, and the results of the clinical cases almost coincide with these experimental results.

Angiography↗
PubMed1984

Pluridirectional macrotomography with three-fold magnification. An assessment of image quality and clinical application.

The purpose of this paper is to present the possible usefulness of macrotomography with three-fold magnification as demonstrated by a new apparatus. It can perform both conventional tomography and macrotomography of the same object plane. Quantitative evaluation included measurements of resolution, modulation transfer function and radiation dose. Qualitative evaluation included an analysis of clinical cases in which both techniques were used. The superior image quality of macrotomography with three-fold magnification was demonstrated and the clinical areas in which it proved most helpful are defined.

Humans↗
PubMed1983

[Effects of radiotherapy combined with daily intramuscular injection of bleomycin for uterine cervical cancer].

A total of 103 cases of cancer of the uterine cervix, untreated previously, were treated with radiotherapy combined with daily intramuscular injection of Bleomycin 30 minutes before irradiation (BR therapy) in 12 institutions. Result showed that especially in cases of stage III, BR therapy was superior in primary local control rate (89.6%), recurrence rate (20.8%) and crude 5-year survival rate (56.5%) to that of nationwide statistics. No severe side effects were found. It was concluded that external radiotherapy could control advanced cancers of uterine cervix combining with intramuscular injection of Bleomycin.

Bleomycin↗