Sexual interactions with unfamiliar females reduce hippocampal neurogenesis among adult male rats.

Recent experiments have shown that sexual interactions prior to cell proliferation cause an increase in neurogenesis in adult male rats. Because adult neurogenesis is critical for some forms of memory, we hypothesized that sexually induced changes in neurogenesis may be involved in mate recognition. Sexually naive adult male rats were either exposed repeatedly to the same sexual partner (familiar group) or to a series of novel sexual partners (unfamiliar group), while control males never engaged in sexual interactions. Ovariectomized female rats were induced into estrus every four days. Males were given two injections of 5-bromo-2'-deoxyuridine (BrdU) (200mg/kg) to label proliferating cells, and the first sexual interactions occurred three days later. Males in the familiar and unfamiliar groups engaged in four, 30-min sexual interactions at four-day intervals, and brain tissue was collected the day after the last sexual interaction. Immunohistochemistry followed by microscopy was used to quantify BrdU-labeled cells. Sexual interactions with unfamiliar females caused a significant reduction in neurogenesis in the dentate gyrus compared to males that interacted with familiar females and compared to the control group. The familiar group showed no difference in neurogenesis compared to the control group. Males in the familiar group engaged in significantly more sexual behavior (ejaculations and intromissions) than did males in the unfamiliar group, suggesting that level of sexual activity may influence neurogenesis levels. In a second experiment, we tested whether this effect was unique to sexual interactions by replicating the entire procedure using anestrus females. We found that interactions with unfamiliar anestrus females reduced neurogenesis relative to the other groups, but this effect was not statistically significant. In combination, these results indicate that interactions with unfamiliar females reduce adult neurogenesis and the effect is stronger for sexual interactions than for social interactions.

Testosterone and social isolation influence adult neurogenesis in the dentate gyrus of male rats.

Testosterone has been previously shown to enhance adult neurogenesis within the dentate gyrus of adult male rats, whereas social isolation has been shown to cause a decrease in adult neurogenesis under some conditions. The current study tested the combined effects of testosterone and social isolation upon adult neurogenesis using two experiments involving adult male rats. For both experiments, half of the subjects were pair-housed and half were housed individually for the duration of the experiments (34 days). For experiment 1, the subjects were divided into four groups (n=8/group): (1) sham/pair-housed, (2) sham/isolated, (3) castrate/pair-housed, and (4) castrate/isolated. Rats in the castrate groups were bilaterally castrated, and rats in the sham groups were sham castrated. For experiment 2, all rats were castrated, and the effects of testosterone were tested using daily injections of testosterone propionate (0.500 mg/rat for 15 days) or the oil vehicle. Subjects were divided into four groups (n=8/group): (1) oil/pair-housed, (2) oil/isolated, (3) testosterone/pair-housed, and (4) testosterone/isolated. All rats were injected with 5-bromo-2'-deoxyuridine (BrdU, 200 mg/kg body mass), and immunohistochemistry was used to determine levels of neurogenesis following a 16-day cell survival period. For experiment 1, castrated subjects had significantly fewer BrdU-labeled cells along the granule cell layer and subgranular zone (GCL+SGZ) of the dentate gyrus than did intact subjects, and this effect was mainly due to low levels of neurogenesis in the castrate/isolated group. For experiment 2, social isolation caused a significant decrease in neurogenesis within the GCL+SGZ relative to the pair-housed groups. Testosterone injections did not buffer against this effect but instead tended to cause a decrease in neurogenesis. Thus, social isolation reduced hippocampal neurogenesis, but the effects of testosterone were inconsistent. This suggests that normal circulating levels of testosterone may buffer against the neurogenesis-impairing effects of isolation, whereas high doses of testosterone do not.

Comparative tolerability of first-generation selective estrogen receptor modulators in breast cancer treatment and prevention.

In general, the selective estrogen receptor modulators (SERMs) currently indicated for the treatment and prevention of breast cancer, i.e. tamoxifen and toremifene, are fairly well tolerated. However, tamoxifen has been shown to induce hepatocellular carcinomas in rats, but not in humans, and can increase the risk of endometrial cancer in humans by two to three times. Other potentially serious adverse effects which have been associated with tamoxifen and toremifene therapy include vasomotor symptoms, an increased risk of venous thromboembolic events, and an increased incidence of cataracts and ocular toxicity, fatty liver, and nonmalignant hepatic and uterine changes. In addition, long term tamoxifen use almost always results in resistance to the drug and, indeed, has actually been shown to promote tumour proliferation in human breast cancer cells. Both tamoxifen and toremifene display drug interactions with a variety of drug classes. The adverse events associated with these compounds have raised significant concerns regarding their widespread use for the treatment and prevention of breast cancer. In addition, because of the weakness and scarcity of the data on toremifene, any conclusions about its tolerability remain tentative until outcomes of ongoing clinical trials in the adjuvant setting are known. A third SERM, raloxifene, is the focus of several large randomised trials examining its efficacy in the prevention of breast cancer. At present, each potential adverse event needs to be weighed against potential benefits in the decision to undergo SERM treatment. An array of therapies is currently available for patients with breast cancer and women at increased risk of disease; the risk-to-benefit ratio for each agent should be carefully examined in determining the most advantageous regimen.

Pelvic abscess with fistula to the abdominal wall due to verrucous carcinoma.

The case report of a 38-year-old woman with a pelvic abscess resulting from verrucous carcinoma of the uterine cervix is presented. This case is remarkable because the abscess formed a fistula through the anterior abdominal wall and because there was no visible lesion on the cervix. The patient underwent a total abdominal hysterectomy, left salpingectomy, fistulectomy, and removal of the abscess. Diagnosis was made on pathologic examination of the extirpated specimen. Genital tract verrucous carcinoma and genitocutaneous fistulae are reviewed.

Selective estrogen receptor modulators: a controversial approach for managing postmenopausal health.

Hormone replacement therapy (HRT) is considered the standard of care for managing the acute (e.g., hot flashes, vaginal dryness) and long-term (e.g., increased risk of cardiovascular disease, osteoporosis) sequelae of menopause. A group of synthetic nonsteroidal compounds, which act on the estrogen receptor, have been promoted for use as an alternative to hormonal therapy for postmenopausal women. Originally called antiestrogens because of their ability to antagonize the action of estrogen, these compounds possess both agonist and antagonist properties of estrogen action. They are now referred to as selective estrogen receptor modulators (SERMs). This article reviews the mechanism of action and the efficacy and safety data for SERMs currently used for clinical purposes. These data may indicate why the use of SERMs is a controversial alternative to HRT.

Commentary: patient education presentations.

Medical students often learn how to teach through observation of residents and attendings. The project described enables them to actively teach groups of patients, and allows them to begin developing their own style of teaching. It also demonstrates to the students that teaching is a skill to be learned, and methods may vary tremendously.

Declines in patient volume: an obstetrics and gynecology teaching program's response.

Historically, University teaching hospitals have been the primary providers of health care to the indigent population. With the advent of managed health-care plans, the university hospitals have seen a rapid decline in their obstetrical patient populations. This decrease is reflected in the numbers of deliveries and gynecological surgeries. From 1990 to 1995, these changes resulted in a significant decline in deliveries at our hospital, the Lyndon B. Johnson General Hospital. To reverse this ominous trend, we instituted a variety of changes resulting in a more patient-centered system and found an improvement in the numbers of obstetrical patients. In the following report, we describe these changes and the subsequent outcome.

Wound seeding associated with endometrial cancer.

We report a patient with well-differentiated adenocarcinoma of the endometrium who developed a recurrence in the anterior abdominal wall probably secondary to wound seeding at the time of her original surgery. She underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy. She then received 15 mCi of 32P for positive peritoneal washings. She was free of disease until 2 years later when a large lower incision mass developed. She had no evidence for intra-abdominal disease and a radical resection with a myocutaneous flap was undertaken. Radical resection for isolated metastases may be of benefit for patients with endometrial cancer. Patients with positive cytology should be observed closely for incisional recurrence.