Prepulse inhibition and fear-potentiated startle are altered in tissue inhibitor of metalloproteinase-2 (TIMP-2) knockout mice

The ability to discriminate between potential dangers and recall those stimuli is essential for survival. This emotional learning requires the involvement of higher brain structures, including the amygdala, hippocampus and related cortical structures. Long-term changes in synaptic transmission and structure are important for the establishment and consolidation of fear memory. The structural changes associated with this synaptic plasticity likely require alterations in the composition of the extracellular matrix (ECM). ECM integrity is maintained by the opposing action of matrix metalloproteinases (MMPs) and their specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs). To date, no studies have examined the role of MMPs or TIMPs in conditioned fear. Here, we show that neither male nor female mice deficient in TIMP-2 (knockout) exhibit prepulse inhibition of the startle reflex, suggesting deficits in pre-attentional sensorimotor gating. In addition, knockout mice and mice expressing a mutant truncated TIMP-2 (knock-down) show deficits in fear-potentiated startle. This is the first report of a phenotype for the TIMP-2(-/-) mice and suggests that TIMP-2 may play a role in the synaptic plasticity underlying learning and memory.     

Modified Pfannenstiel approach for radical retropubic prostatectomy

Radical retropubic prostatectomy is traditionally performed using a vertical midline incision and occasionally using a transverse Pfannenstiel incision. We describe a technique for performing radical retropubic prostatectomy using a modified Pfannenstiel approach. This involves a Y incision of the rectus sheath, instead of a pure transverse incision, and provides both excellent exposure and better cosmetic results.     

Radical retropubic prostatectomy in Hispanic patients

BACKGROUND: Hispanics are the largest minority group in the U.S. Most studies assessing race as a predictor of biochemical disease recurrence after radical retropubic prostatectomy (RRP) have focused on African-American patients. To the authors' knowledge, little has been published to date regarding radical prostatectomy in Hispanic patients. Hispanics represent 29% of the patients in the current study. The authors analyzed the presentation and outcome of Hispanic males managed with radical prostatectomy. METHODS: In the current study, 1163 RRPs were performed. Patients were categorized by ethnicity as Hispanics, white non-Hispanics, African-Americans, and other ethnicities. African-American and other minority group patients were excluded from the analysis because of the small number in the current series. A comparative analysis of Hispanics and white non-Hispanics was performed. RESULTS: RRP was performed in 1163 patients. Two hundred seven Hispanic and 518 white non-Hispanic patients met the study criteria. The mean follow-up was 46.9 months. Twenty-three percent of the Hispanic patients received neoadjuvant therapy. RRP Gleason scores of 2-6, 7, and 8-10 were found in 45% of patients, 38% of patients, and in 17% of patients, respectively. Lymph node metastases were present in 3%, seminal vesicle invasion in 13%, and extraprostatic extension in 23% of Hispanic patients. Adjuvant hormonal therapy was administered to 6% of the Hispanic patients. The biochemical disease recurrence rate was 12%. The mean time to biochemical disease recurrence was 29.7 months. A comparison between the Hispanic and the white non-Hispanic groups showed no significant differences in the analyzed variables. CONCLUSIONS: Hispanic patients managed with radical prostatectomy for prostate carcinoma were found to have similar presentation, pathologic findings, and outcome as the white non-Hispanic patients.