Contrafreeloading in Rats Is Adaptive and Flexible: Support for an Animal Model of Compulsive Checking.

Contrafreeloading involves working unnecessarily to obtain a reward that is otherwise freely available. It has been observed in numerous species and can be adaptive when it provides an organism with updated information about available resources. Humans frequently update their knowledge of the environment through checking behaviors. Compulsive checking occurs when such actions are performed with excessive frequency. In a putative animal model of compulsive checking, rats treated chronically with the dopamine agonist quinpirole display exaggerated contrafreeloading for water. Although this effect has been attributed to behavioral rigidity, some evidence suggests the behavior remains somewhat flexible and may be adaptive under certain conditions. We assessed the ability of quinpirole-treated rats with contrafreeloading experience to adapt to changing contingencies by requiring them to alternate between response levers. Rats treated with quinpirole or saline were first trained to obtain water by pressing either of two levers. Next, free water was made available for 8 days, and contrafreeloading was measured. Rates of contrafreeloading were significantly higher in the drug-treated rats than in controls. On the following 5 days, each reward caused the associated lever to become inactive until a reward was earned from the alternate lever. Quinpirole-treated rats learned this new response requirement more quickly than controls. Thus, exaggerated checking behavior induced by chronic quinpirole treatment can be advantageous when environmental contingencies change. These results provide support for this animal model of compulsive checking and hint at the presence of a specialized neural checking module involving the dopamine system.

Chest Surgery in Female to Male Transgender Individuals.

BACKGROUND: Societal awareness of transgender individuals has led to increased acceptance and demand for sex-confirming surgery. In female to male transsexuals, the most common procedure is removal of breast tissue to masculinize the chest. METHODS: Eighty-eight transgender patients underwent either a subcutaneous nipple-sparing mastectomy (NSM) with or without a periareolar mastopexy or nipple reduction, or bilateral mastectomies with free nipple grafts (MFNG) with or without nipple reduction. Surgical techniques are discussed. Demographic data, use of testosterone, specimen weights, rates of wound dehiscence, infection, hematoma, hypertrophic scars, nipple loss, and revision surgery were all assessed. RESULTS: Of the 88 patients in the study, 40 underwent NSM and 48 underwent MFNG. Patients undergoing NSM were 4.1 times more likely to have a hematoma compared with patients undergoing MFNG (P <0.05). Mastectomy weight was not correlated with the occurrence of hematoma (P >0.80). Only 1 patient who underwent NSM required revision, whereas 5 patients in the MFNG patient population underwent revision. Patients were more likely to have hypertrophic scarring with the MFNG technique (0% vs 25%, P < 0.01) There were no infections, no wound dehiscence, and no nipple loss in any patient. Eighty-three percent of the patients who responded to a satisfaction survey (57/88) were very satisfied with their result, and 100% would recommend this procedure to other transgender individuals. CONCLUSIONS: Female to male transgender mastectomy can be performed with low complication rates and high satisfaction. Nipple-sparing mastectomy were more likely to have a hematoma than patients undergoing MFNG.

Nipple-sparing mastectomy in patients with previous breast surgery: comparative analysis of 775 immediate breast reconstructions.

BACKGROUND: An increasing number of women are candidates for nipple preservation with mastectomy. It is unclear how previous breast surgery impacts nipple-sparing mastectomy and immediate breast reconstruction. METHODS: A single-institution retrospective review was performed between June of 2007 and June of 2013. RESULTS: Four hundred forty-four patients underwent 775 immediate breast reconstructions after nipple-sparing mastectomy. Of these, 160 patients and 187 reconstructions had previous breast surgery, including 154 lumpectomies, 27 breast augmentations, and six reduction mammaplasties. Two hundred eighty-four patients with 588 reconstructions without previous breast surgery served as the control group. The previous breast surgery patients were older (49.6 years versus 45.8 years; p < 0.001) but otherwise had similar demographics. Previous breast surgery reconstructions were more often unilateral, therapeutic, and associated with preoperative radiotherapy (p < 0.001 for each). Extension of breast scars was common with previous breast surgery, whereas the inframammary incision was most frequent if no scars were present (p < 0.001). Multivariate regression analysis showed that previous breast surgery was not a significant risk factor for ischemic complications or nipple loss. Subgroup analysis showed extension of prior irradiated incisions was predictive of skin flap necrosis (OR, 9.518; p = 0.05). A higher number of lumpectomy patients had preoperative radiotherapy (41 versus 11; p < 0.001), and patients with breast augmentation had more single-stage reconstructions (85.2 percent versus 62.9 percent; p = 0.02). CONCLUSION: Nipple-sparing mastectomy and immediate reconstruction can be performed in patients with prior breast surgery with no significant increase in nipple loss or ischemic complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Birth weight predicts scores on the ADHD self-report scale and attitudes towards casual sex in college men: a short-term life history strategy?

Early development can have long-term effects on physiology and behavior. While severe disturbances predictably lead to dysfunction, recent work in humans and animals has led to a growing appreciation for the more subtle ways in which early conditions can modulate behavioral tendencies later in life. Life history theory predicts that early cues signaling a stressful or suboptimal environment might lead an organism to adopt a strategy favoring short-term gains and early reproduction. Fifty college men reported their birth weight, completed the Attention-Deficit/Hyperactivity Disorder (ADHD) Self-Report Scale, and answered a series of questions about their sexual history and attitudes towards short-term sexual encounters. Lower birth weights were associated with higher scores on the ADHD scale (r = -.352; p ≤ .05) and more favorable attitudes towards casual sex (r = -.456; p ≤ 0.001). There was a significant interaction between birth weight and casual sex favorability in predicting number of sexual partners (F1,46 = 4.994; p ≤ .05). This suggests that, although men who are smaller at birth may otherwise be at a disadvantage in reproductive terms, they may offset their reduced fitness by being more willing to engage in casual sex.

Long-term renal function and cardiovascular disease risk in obese kidney donors.

BACKGROUND AND OBJECTIVES: Increasing demand for live-donor kidneys has encouraged the use of obese donors despite the absence of long-term outcome data and evidence that obesity can adversely affect renal function. We wished to determine whether obesity increased the risk for renal dysfunction and other medical comorbidities in donors several years after donation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Ninety-eight patients who donated a kidney 5 to 40 years previously were stratified according to body mass index (BMI) at donation and evaluated for renal dysfunction and risk factors for cardiovascular disease. Patients who were from the 2005 through 2006 National Health and Nutrition Examination Survey database; did not have renal disease; and were matched for age, gender, race, and BMI served as two-kidney control subjects. RESULTS: Renal function in obese (BMI > or =30) and nonobese (BMI <30) donors was similar, and both donor groups had reduced renal function compared with BMI-matched two-kidney control subjects. Obesity was associated with more hypertension and dyslipidemias in both donors and two-kidney control subjects; however, there were no significant differences between the two groups within each BMI category. CONCLUSIONS: These results indicate that obese donors are not at higher risk for long-term reduced renal function compared with nonobese donors and that the increased incidence of hypertension and other cardiovascular disease risk factors in obese donors is due to their obesity and is not further exacerbated by nephrectomy. These findings support the current practice of using otherwise healthy overweight and obese donors but emphasize the need for more intensive preoperative education and postoperative health care maintenance in this donor group.