A retrospective review of factors associated with vasovasostomies in United States military members.

BACKGROUND: Men seeking a vasectomy should receive counseling prior to the procedure that includes discussion of later seeking a reversal. We sought to determine demographic factors that may predispose patients to possibly later seek a vasectomy reversal. METHODS: All U.S. Military electronic health records were searched between 2000 and 2009 for either a vasectomy or vasovasostomy procedure code. Aggregate demographic information was collected and statistical analysis performed. RESULT: A total of 82,945 patients had a vasectomy of which 4,485 had a vasovasostomy resulting in a vasovasostomy-to-vasectomy rate of 5.04%. The average age at vasovasostomy was 34.9±5.0, with an average interval of 4.1±2.2 years. Men undergoing a vasectomy at a younger age were more likely to have a vasovasostomy. Various religions did have statistically significant differences. Within ethnic groups, only Native Americans [OR=1.39 (95% CI 1.198-1.614)] and Asians [OR=0.501 (95% CI 0.364-0.690)] had statistically significant differences when compared to Caucasians. Men with more children at the time of vasectomy were more likely to have a vasovasostomy. CONCLUSION: Younger men, Native Americans, and men with more children at vasectomy were more likely to undergo a vasovasostomy. The reason for these differences is unknown, but this information may assist during pre-vasectomy counseling.

Monitoring the serological proteome: the latest modality in prostate cancer detection.

PURPOSE: Various strategies have recently emerged to improve the diagnostic prediction of prostate cancer (CaP). One such strategy includes the mass profiling of serum protein fractions selectively adsorbed onto chemically modified probes. In the current study we further validated this approach, while offering a more versatile, less expensive and yet equally predictive alternative to existing technologies. MATERIALS AND METHODS: A solid core lipophilic C-18 resin was used to extract and enrich the low molecular weight protein fraction from patient serum for further analysis by mass spectrometry. Mass spectra generated from a 48 patient training set were data mined using multivariate analysis to identify diagnostically significant protein peaks. These peaks were then used to test a blinded study set comprising 168 patients with common statistical algorithms and commercially available software packages. RESULTS: A total of 36 peaks generated from the training set were used to test the combined set of 168 serum samples obtained from 98 healthy individuals and 70 patients with CaP. We report a sensitivity of 94.1% and a specificity of 99.0% with 1 false-positive, 4 false-negative and 5 nondiagnosed cases. CONCLUSIONS: Our results further indicate that mass profiling of serological proteins provides a means for the accurate detection of CaP. In addition, our approach was found to be superior to chip based protocols, generating rich, sharp, highly reproducible spectra attainable in a high throughput manner and at minimal cost. This technique is also scaleable for subsequent protein characterization using multidimensional protein identification technologies. Finally, analyses of mass spectra with commercially available statistical applications was found to be highly effective in generating highly discriminatory m/z values for CaP diagnosis.

The mechanics of corporal veno-occlusion in penile erection: a theory on the effect of stretch-associated luminal constrictability on outflow resistance.

In order to further our understanding of the physiology of corporal veno-occlusion, we developed a theory of a possible contribution to corporal venous outflow resistance which occurs as the result of venule stretching with resultant luminal narrowing when penile volume increases during the erection process. We stretched non-biological tubes and rabbit abdominal vena cava segments, performed flow-based and volume-based experiments to calculate the magnitude of N, the newly defined 'stretch-associated luminal constrictability' factor. We solved for (R(s)/R(u)), the ratio of the venule fluid resistance in the stretched state (R(s)) to the unstretched state (R(u)), to quantify the projected increases in fluid resistance as well as Q.R(u) where Q is the subtunical venule flow rate. For a given tube, N was found to be essentially constant for different amounts of stretch. A theory was formulated which predicted R(s) and Q as a function of N, DeltaP (intracavernosal pressure increase); V(E)/V(F) (tunical distensibility); X (cavernosal expandability) and R(u). Based on the magnitude of N=2, this theory predicts that patients with the highest values of both V(E)/V(F) and X would have maximal R(s) values, approaching infinity (complete occlusion) at a low DeltaP near 5 mmHg. In contrast, patients with low values of both V(E)/V(F) (eg Peyronie's disease) and X (eg corporal fibrosis), would be predicted to have minimal R(s) values. For example, a hypothetical patient with the lowest values of V(E)/V(F) and X would yield R(s) values only approaching 7.9 times that of unstretched values at a DeltaP increase of 90 mmHg. We concluded to that stretch-associated venule resistance may occur as a result of decreased sub-tunical venule diameter and increased sub-tunical venule length. In individual patients, stretch-associated venule resistance may either dominate or be a minor component of the overall mechanism of corporal veno-occlusion.