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Biomedical subjects

K Akasofu

Publications and source records attributed to K Akasofu.

At least 19 recordsLinked to original sources
PubMed1995

Induction of ductal carcinomas by intraductal administration of 7,12-dimethylbenz(a)anthracene in Wistar rats.

Postpartum Wistar inbred rats (weaned on the 9th puerperal day) were injected intraductally in one mammary gland with 7,12-dimethylbenze (a) anthracene (DMBA) to selectively induce ductal carcinoma. The incidence of ductal hyperplasia increased with time until it peaked at 7 weeks (12/13 animals) and then decreased. Ductal carcinoma first developed at 9 weeks in 3/12 (2 non-invasive and 1 invasive lesion) and the incidence increased with time until invasive ductal tumors were observed in 9/11 at 20 weeks. Tumors developed only in the DMBA-treated mammary glands and no systemic effects of the carcinogen were observed. Degeneration and detachment of epithelioglandular cells were seen here and there in the ducts and terminal ducts, and epithelioglandular cells proliferated in terminal duct until 2 weeks. Residual trace DMBA powder was detected in terminal ducts and the epithelioglandular layer until 7 weeks. This trace DMBA was considered to be the cause of the development of atypical epithelial cells, inducing ductal carcinomas.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1994

Noncontact stimulation from estrous females evokes penile erection in rats.

Five experiments demonstrated that noncontact stimulation from estrous females evokes penile erection in a high proportion of sexually experienced male rats. In Experiment 1, 23 of 24 males (96%) displayed erections while separated from estrous females by a wire-mesh barrier, compared with 8% when no female was present. In Experiment 2, inaccessible estrous females stimulated erection in 100% of males, whereas only 38% responded to inaccessible unfamiliar males and 0% to inaccessible preferred food or an empty cage (n = 8/group). These data suggest that nonsexual arousing stimuli do not readily evoke erections. Experiments 3 and 4 demonstrated that bedding collected from estrous females is highly attractive to males, but is ineffective in promoting erections even when the males can burrow in the bedding. Therefore, estrous odors alone are apparently insufficient to stimulate erection. In Experiment 5, the percentage of males (n = 18) responding with erection did not vary significantly as a function of their exposure to ovariectomized females (67%), receptive but nonproceptive females (83%), or proceptive females (89%), but these stimuli were progressively more effective in reducing erection latency and increasing the number of erections displayed, suggesting that behavioral cues emitted by females promote erection. The display of erection by rats under the conditions used in these studies satisfies conventional criteria for recognition as psychogenic erections, which we have provisionally defined as erections that occur without concurrent somesthetic stimulation. The availability of a rodent model of psychogenic erection should foster analysis of its physiological mediation.

Animals↗
PubMed1994

Effects of copulation on apomorphine-induced erection in rats.

By testing the effects of antecedent copulation on subsequent apomorphine-induced penile erection we sought to test an implicit assumption in the research on drug-induced "spontaneous" erection--namely, that this research provides information relevant to the regulation of erection in copula. In experiment 1, male rats were observed after being injected SC with 0, 15, 30, 60, or 120 micrograms/kg apomorphine (APO); 60 micrograms/kg yielded the maximum probability of erection and yawning. In experiment 2, males were injected with 60 micrograms/kg APO after no exposure to females, after three intromissions, or after copulation to sexual satiety. There was no significant effect of three intromissions, but sexually sated males displayed no erections, the first evidence that copulation affects drug-induced erections. In experiment 3, males had one ejaculation, three intromissions, or no exposure to females immediately before injection with APO (60 micrograms/kg, SC) or ascorbic acid vehicle. APO induced both erection and yawning, but neither behavior was reliably affected by copulation in APO-treated males. Among vehicle-treated males, those having three intromissions or one ejaculation before the test had shorter erection latencies and more erections than males not exposed to females. Thus, a relatively small amount of copulation resulted in a level of erectile response similar to that of APO-treated males. Optimal doses of APO may be no more effective in promoting erection in male rats than are the natural neurochemical sequelae to copulation.

Animals↗
PubMed1994

Etiology of prune belly syndrome: evidence of megalocystic origin in an early fetus.

BACKGROUND: Prune belly syndrome is a rare and complicated condition affecting the genitourinary organs and abdominal wall. The etiology of abdominal musculature deficiency in prune belly syndrome is controversial. We present a case that should elucidate the etiology of this syndrome. CASE: A spontaneously aborted fetus at 12 weeks' gestation with an early stage of prune belly syndrome was investigated by necropsy and light and electron microscopy. Megalocystis resulting from urethral atresia was diagnosed. There was no hydroureter or hydronephrosis, and both light and electron microscopy demonstrated evidence of development of the abdominal musculature. Both testes were elevated as a result of the megalocystis. CONCLUSION: These findings suggest that hypoplasia of the abdominal musculature and cryptorchidism might develop secondary to the presence of chronic megalocystis in this syndrome.

Abdominal Muscles↗
PubMed1993

Parovarian fibroma with heterotopic bone formation of probable wolffian origin.

Parovarian neoplasms of wolffian duct origin are very unusual. This article presents the first report of a case of parovarian fibroma with heterotopic bone formation of probable wolffian duct origin. The tumor cells present among mature collagen bundles were fibroblast-like cells, while those at the sites of cellular proliferation were either undifferentiated mesenchymal cells or had differentiated into osteoblasts. In the bone matrix, the tumor cells had differentiated into osteoblasts and connective tissue had ossified.

Adult↗
PubMed1993

Vulvar angioleiomyoma.

A rare case of vulvar angioleiomyoma was diagnosed, and examined by electron microscope. The tumor cells appeared to be derived from pericytes. Intracytoplasmic inclusions, which are sometimes observed in infantile digital fibroma, were noted in the myofibroblasts.

Adult↗
PubMed1993

Effects of oestrogen on hypothalamic beta-endorphin in ovariectomized and old rats.

Immunocytochemical beta-endorphin (beta-EP) staining and ultrastructural observations in the hypothalamus were compared in normal mature female rats, ovariectomized rats, and aged female rats. The effects of oestradiol benzoate (EB) on the hypothalamus were studied. The female Wistar rats were divided into seven groups, as follows: 40-day-old rats (Mature), 54-day-old rats ovariectomized at 40 days (Ovx), rats ovariectomized at 40 days and injected with 0.1 mg EB daily for 7 days (Ovx + e) rats ovariectomized and injected with one dose of 1 mg EB (Ovx + E), 500-day-old (Old), old rats injected with 0.1 mg EB daily for 7 days (Old + e), and old rats injected with 1 mg EB (Old + E). In the Ovx and Old groups, beta-EP-positive cells in the arcuate nucleus were rarely seen, as compared with the Mature group. The staining of beta-EP-positive cells in Ovx + e was slightly recovered and that in Ovx + E was almost completely recovered. However, no recovery of beta-EP-positive cells was seen in the Old + e or Old + E groups. The number of nerve fibers in the median eminence were reduced in both the Ovx and Old groups, as compared with the Mature group. There was no relationship between changes in these numbers and oestrogen replacement in the Old group, but in the Ovx group oestrogen replacement brought about recovery of these numbers. The number of glial cells increased after oestrogen replacement in both the Ovx and Old groups. The frequency of giant mitochondria in the neurons in the arcuate nucleus decreased after oestrogen replacement in the Old group.

Aging↗
PubMed1993

Effects of testosterone on the development of endometrial tumors in female rats.

Long-term treatment of mature virgin female rats with a high dose of testosterone (24 weeks at a total dose of 300 mg) was associated with the development of endometrial adenomatous hyperplasia and resulted in a high incidence of adenocarcinoma when administered in combination with 7,12-dimethyl-benz[a]anthracene (DMBA; 2 mg in 0.1 ml sesame oil) introduced into the uterine cavity. Adenomatous hyperplasia occurred in all testosterone-treated rats, both with and without ovaries. Testosterone may promote the induction of endometrial tumors by DMBA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1993

A follicular cyst during tamoxifen therapy in a premenopausal breast cancer woman.

A large ovarian follicular cyst developed on day 43 of low-dose tamoxifen adjuvant therapy for a premenopausal breast cancer (total drug intake: 860 mg). The serum estradiol level increased to almost ten times the pretreatment level. However, the FSH and LH decreased slightly, and the serum progesterone level remained almost unchanged. It is hypothesized that tamoxifen acted directly on the ovaries to provoke excessive proliferation of the granulosa cells in a follicular cyst, causing it to grow very large, and resulting in elevated E2 levels.

Adult↗
PubMed1993

Partial hydatidiform mole in the fallopian tube.

An extremely rare case of partial hydatidiform mole located in the right Fallopian tube was diagnosed by ultrasonography and computed tomography. The lesion was excised, and the human chorionic gonadotropin (HCG) level in early morning urine fell below 1,000 IU/ml on postoperative day 11, and the serum HCG-beta level normalized on postoperative day 46.

Adult↗
PubMed1993

Adrenal steroids in serum during danazol therapy, taking into account cross-reactions between danazol metabolites and serum androgens.

To investigate the changes in the serum androgen concentrations and the Free Androgen Index (FAI) in women during danazol therapy, we measured the serum concentrations of adrenal steroids and danazol metabolites, and then examined the effects of danazol metabolites on assays for serum androgens. Thirteen women who had endometriosis were treated with danazol (300 or 400 mg/day) for 8 to 16 weeks. Blood samples were taken before, during, and after the medication. During the danazol therapy, serum testosterone (T), cortisol (F), and sex-hormone binding globulin (SHBG) significantly decreased (P < 0.05); but serum dehydroepiandrosterone-sulfate (DHEAS) and FAI increased (P < 0.05). The serum concentrations of danazol metabolites were: danazol, 209.0 +/- 28.3 (ng/mL, mean +/- SEM); delta 1-2-hydroxymethyl ethisterone, 114.4 +/- 8.4; and 2-hydroxymethyl ethisterone, 660.0 +/- 54.2. There was considerable cross-reaction between danazol metabolites and androgens [T, androstenedione (A), and dehydroepiandrosterone (DHEA)] in the direct assays. As for the ratios of adrenal steroids in serum, the DHEAS/F, DHEAS/DHEA, and 11-deoxycortisol (S)/F ratios increased (P < 0.05). We conclude that the increase in FAI and DHEAS represents increased native androgenic activity with danazol, and the changes in adrenal steroid ratios in serum indicate the inhibition of 11 beta-hydroxylase and sulfatase activities during danazol therapy.

Adrenal Glands↗
PubMed1993

Levels of androgens and danazol metabolites in serum during danazol therapy.

Thirteen women who had endometriosis were treated with danazol (300 to 400 mg/d). Levels of androgens and danazol metabolites in serum and the influences of danazol metabolites on the assays for serum androgen were investigated during danazol therapy. Serum DHEAS significantly increased (P < 0.05), but serum DHEA slightly decreased. Serum T levels, measured by direct assay, were markedly elevated. However, measured after HPLC separation, the T levels in serum were significantly decreased (P < 0.05). There were considerable cross-reactions between danazol metabolites and androgens (T, DHEA, and A) in RIA. Purification of androgens using column chromatography was necessary to measure serum androgens precisely.

Adult↗
PubMed1992

Vaginal schwannoma.

In the patient reported here, a solid tumor lying between the vagina and the rectum was detected using various imaging techniques (ultrasonography and MRI), and S100 protein was found in the tumor cells. Thus, a schwannoma was the final diagnosis. This is a slow-growing neoplasm, and its early detection is difficult.

Female↗
PubMed1992

Phyllodes tumor in a patient with a preexistent fibrocystic disease.

A phyllodes tumor appeared at the site of a resected fibrocystic disease focus. Administration of danazol resulted in temporary regression, but the tumor resumed growth. Relative hyperestrogenism also continued to increase in spite of continued long-term administration of danazol. After 12 months a simple mastectomy was performed. Most of the resected mass consisted of the phyllodes tumor, but it also contained fibrocystic disease.

Adult↗