Prevalence and predictors of conscious risk behavior among San Franciscan men who have sex with men

We estimated the prevalence of conscious risk, specifically defined as unprotected anal intercourse with an HIV-serodiscordant partner, and identified individual-level and partnership-level predictors of this behavior. Conscious risk was estimated to be practiced by 4.8% of HIV-negative MSM and 15.7% of HIV-positive MSM over a six-month period (p < 0.01). Among HIV-negative MSM, episodes of conscious risk were estimated to be more frequent among individuals between the ages of 18 and 24 (compared to those 55 years of age or older), among African Americans and Whites (compared to Latinos and Asians), individuals earning less than 10,000 dollars per year (compared to those earning 50,000 and 70,000 dollars per year), and among users of methamphetamine, downers, pain killers, and amyl nitrate (poppers). Among HIV-positive MSM, episodes of conscious risk were more frequent among Whites and Asians (compared to those of "other" races, i.e., those of mixed race, or those who did not exclusively self-report as White, Black, Latino, or Asian), those with full-time employment (as opposed to those with part-time employment), those earning between 30,000 and 50,000 dollars per year or 70,000 dollars per year or greater (compared to those earning under 10,000 dollars per year), and recent users of poppers. Conscious risk was more frequently reported in partnerships with large age gaps and in main partnerships (as opposed to casual or exchange partnerships). Individuals at high risk for conscious risk may be ideal candidates for pre-exposure prophylaxis (PrEP).

Cloning, expression and characterization of lepidopteran isopentenyl diphosphate isomerase

Isopentenyl diphosphate isomerase (IPPI) of the spruce budworm, Choristoneura fumiferana, and of the tobacco hornworm, Manduca sexta, was cloned and its catalytic properties assessed. In the presence of Mg(2+) or Mn(2+), the recombinant protein from C. fumiferana (CfIPPI) efficiently isomerized IPP to dimethylallyl diphosphate (DMAPP). While C. fumiferana IPPI transcript levels were evenly distributed in a wide variety of tissues, they were highly abundant in the corpora allata. Because IPPI plays an alternate role in lepidopteran juvenile hormone (JH) biosynthesis by catalyzing the isomerization of the homologous substrate, homoisopentenyl diphosphate (HIPP), the ability of CfIPPI to convert HIPP to homodimethylallyl diphosphate (HDMAPP) was also studied. As expected, HIPP isomerization was efficient and the formation of HDMAPP occurred, but the regiospecificity of the reaction was lower than previously found in M. sexta corpora allata homogenates and with purified Bombyx mori IPPI. Differences in inhibitory potency for several alkylated ammonium diphosphates and higher homologs of DMAPP were noted between CfIPPI and a vertebrate IPPI, suggesting that the lepidopteran enzyme has a larger active site cavity. To determine the structural factors responsible for homologous substrate coupling, site directed mutagenesis of several residues identified through sequence alignment and homology modeling analysis was performed. The results suggest that unlike other IPPIs, W216 (C. fumiferana numbering) works in concert with a tyrosine residue (Y105) to allow binding of larger substrates and to stabilize the high-energy intermediate formed during substrate isomerization.

3.0 T multiparametric prostate MRI using pelvic phased-array coil: utility for tumor detection prior to biopsy

OBJECTIVE

To evaluate the role of multiparametric magnetic resonance imaging (MRI) performed in men without a biopsy-proven diagnosis of prostate cancer using follow-up biopsy as the reference standard.

MATERIALS AND METHODS

Forty-two patients without biopsy-proven cancer and who underwent MRI were included. In all patients, MRI was performed at 3T using a pelvic phased-array coil and included T2-weighted imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging. Thirteen had undergone no previous biopsy, and 29 had undergone at least 1 previous negative biopsy. All patients underwent prostate biopsy following MRI. Two fellowship-trained radiologists in consensus reviewed all cases and categorized each lobe as positive or negative for tumor. These interpretations were correlated with findings on post-MRI biopsy.

RESULTS

Follow-up biopsy was positive in 23 lobes in 15 patients (36% of study cohort). On a per-patient basis, MRI had a sensitivity of 100%, specificity of 74%, positive predictive value (PPV) of 68%, and negative predictive value (NPV) of 100%. On a per-lobe basis, MRI had a sensitivity of 65%, specificity of 84%, PPV of 60%, and NPV of 86%. There was a nearly significant association between Gleason score and tumor detection on MRI (P = 0.072).

CONCLUSIONS

In our sample, MRI had 100% sensitivity in predicting the presence of tumor on subsequent biopsy on a per-patient basis, suggesting a possible role for MRI in selecting patients with an elevated prostatic specific antigen (PSA) to undergo prostate biopsy. However, MRI had weaker specificity for prediction of a subsequent positive biopsy, as well as weaker sensitivity for tumor on a per-lobe basis, indicating that in patients with a positive MRI result, tissue sampling remains necessary for confirmation of the diagnosis as well as for treatment planning.

Ureteroscopic and extirpative treatment of upper urinary tract urothelial carcinoma: a 15-year comprehensive review of 160 consecutive patients

Study Type--Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? Upper urinary tract urothelial carcinomas (UTUC) have historically been treated with radical, extirpative surgery, primarily nephroureterectomy with bladder-cuff excision. In general, there has been growing interest in renal preservation, as evidenced by the broadening application of nephron-sparing surgery for renal parenchymal tumours. Beyond imperative reasons such as tumour in a solitary kidney, bilateral disease, or comorbidities preventing radical surgery, there is a growing role for endoscopic management of upper tract tumours. The aim has been to obtain similar oncological results to those of extirpative surgery, while preserving long-term renal function. Properly selecting patients for these therapies, designing specific treatments based on a complex presentation, and general information with regard to outcomes and risks for patient counselling have been based historically on results from relatively small series without long-term follow-up. This study reflects all patients with UTUC treated by a single tertiary referral surgeon, accrued prospectively over 15 years using the same surgical techniques and treatment algorithms throughout the entire study period, with 10-year survival data. The consecutively accrued nature and size of the study groups, uniformity in treatments, statistical review and long-term follow-up provide baseline oncological data that could help frame future study.

OBJECTIVE

• To present long-term oncological outcomes of all patients treated surgically for upper urinary tract urothelial carcinoma (UTUC) over a 15-year period.

PATIENTS AND METHODS

• All patients (N = 160) treated from January 1996 to August 2011 were prospectively studied and placed into three distinct groups after initial diagnostic ureteroscopy (URS): Group 1: low grade lesions treated with URS (n = 66); Group 2: high grade lesions palliatively treated with URS (n = 16); and Group 3: extirpative surgery (nephroureterectomy [NU]; n = 80). • Statistical analysis was performed using Kaplan-Meier methodology to calculate overall (OS), cancer-specific (CSS) and metastasis-free survival (MFS).

RESULTS

• The median patient age at presentation was 73 years, and the mean (range) follow-up time was 38.2 (1-185) months. At initial diagnostic URS, 71 (44.4%) patients presented with high grade and 89 (55.6%) patients presented with low grade disease. • The 2-, 5- and 10-year CSS rates were 98, 87 and 81% for patients with low grade disease, and 97, 87 and 78% for patients treated with URS (Group 1), not significantly different from those patients with low grade disease treated with NU (Group 3), (P = 0.54). • Of the patients treated with URS for low grade disease, 10 (15.2%) progressed to high grade disease at a mean time of 38.5 months. • Patients with high grade disease treated with NU had a 2-, 5-, and 10-year CSS of 70, 53 and 38%, with a MFS of 55, 45 and 35%. • Median survival of patients with high grade disease treated with palliative URS was 29.2 months with a 2-year OS of 54%. • On multivariate analysis only high grade lesion on initial presentation was found to be a significant factor (P < 0.001; hazard ratio = 7.27).

CONCLUSIONS

• Grade is the most significant predictor of OS and CSS in those with UTUC, regardless of treatment method. • Ureteroscopic and extirpative therapy are acceptable options for those with low grade disease showing excellent long-term CSS. • Extirpative therapy was found to result in relatively poor long-term CSS in patients with high grade disease, underscoring the need for adjuvant or neoadjuvant therapies.

Behavior, intention or chance? A longitudinal study of HIV seroadaptive behaviors, abstinence and condom use

Seroadaptive behaviors have been widely described as preventive strategies among men who have sex with men (MSM) and other populations worldwide. However, causal links between intentions to adopt seroadaptive behaviors and subsequent behavior have not been established. We conducted a longitudinal study of 732 MSM in San Francisco to assess consistency and adherence to multiple seroadaptive behaviors, abstinence and condom use, whether prior intentions predict future seroadaptive behaviors and the likelihood that observed behavioral patterns are the result of chance. Pure serosorting (i.e., having only HIV-negative partners) among HIV-negative MSM and seropositioning (i.e., assuming the receptive position during unprotected anal sex) among HIV-positive MSM were more common, more successfully adhered to and more strongly associated with prior intentions than consistent condom use. Seroconcordant partnerships occurred significantly more often than expected by chance, reducing the prevalence of serodiscordant partnerships. Having no sex was intended by the fewest MSM, yet half of HIV-positive MSM who abstained from sex at baseline also did so at 12 month follow-up. Nonetheless, no preventive strategy was consistently used by more than one-third of MSM overall and none was adhered to by more than half from baseline to follow-up. The effectiveness of seroadaptive strategies should be improved and used as efficacy endpoints in trials of behavioral prevention interventions.

Amelioration of renal ischemia-reperfusion injury with a novel protective cocktail

PURPOSE

Extended warm ischemia during partial nephrectomy can lead to considerable renal injury. Using a rat model of renal ischemia we examined the ability of a unique renoprotective cocktail to ameliorate warm ischemia-reperfusion injury.

MATERIALS AND METHODS

A warm renal ischemia model was developed using 60 Sprague-Dawley® rats. The left renal artery was clamped for 40 minutes, followed by 48 hours of reperfusion. A renoprotective cocktail of a mixture of specific growth factors, mitochondria protecting biochemicals and Manganese-Porphyrin (MnTnHex-2-PyP(5+)) was given intramuscularly at -24, 0 and 24 hours after surgery. At 48 hours the 2 kidneys were harvested and examined with hematoxylin and eosin, and periodic acid-Schiff stains. Protein and gene expression were also analyzed to determine ischemia markers and the antioxidant response.

RESULTS

Compared to ischemic controls, kidneys treated with the renoprotective cocktail showed significant reversal of morphological changes and a significant decrease in the specific ischemic markers lipocalin-2, mucin-1 and galectin-3. Quantitative reverse transcriptase-polymerase chain reaction revealed up-regulation of several antioxidant genes in treated animals.

CONCLUSIONS

According to histopathological and several molecular measures our unique renoprotective cocktail mitigated ischemia-reperfusion injury.

Flexible ureteroscopy update: indications, instrumentation and technical advances

Retrograde ureteroscopy has recently gained a broadened indication for use from diagnostic to a variety of complex minimally invasive therapies. This review aims to look at the recent advances in the instrumentation and accessories, the widened indications of its use, surgical techniques and complications. With minimization of ureteroscopic instruments manufacturers are challenged to develop new, smaller and sturdier instruments that all will also survive the rigors of surgical therapy.

Hypoxic pre-conditioning in a rat renal ischemia model: an evaluation of the use of hydralazine

INTRODUCTION

With the advent of improved diagnostic and imaging techniques, it is now possible to detect renal cancers in their very early stages, when they are still present as small renal masses. In these situations, use of laparoscopic partial nephrectomy (LPN) techniques are indicated and have gained acceptance in major medical institutions worldwide, offering comparable oncological outcomes and improving quality of life in the patient when contrasted with open nephrectomy procedures. However, a complication that may occur during or after this surgery is the possibility of compromising renal function, as a result of extended ischemia times of more than 30 min. We have undertaken a systematic study of the potential of several agents that may enhance renal parenchymal preservation without causing unwanted renal dysfunction as a result of enhanced ischemia times. In this study, we have evaluated the potential of one such agent under study, namely hydralazine, which was shown earlier to enhance hypoxia inducible factor-1α (HIF-1α) levels in experimental animal systems. Our aim was to determine whether enhanced levels of HIF-1α via pre-treatment with hydralazine had a reno-protective effect after ischemic injury.

MATERIALS AND METHODS

Rats were injected with hydralazine or saline for 5 days prior to right nephrectomy and 40 min of cross-clamping of the left renal pedicle. Ischemic damage was monitored via serum chemistry and renal pathology.

RESULTS

In our system, we found that hydralazine pre-treatment, even though it enhanced HIF-1α levels in the kidney, it also increased serum creatinine and worsened the morphological damage to the renal tubules in the ischemic kidney.

CONCLUSIONS

We conclude that even though this agent was described as a powerful inhibitor of prolyl hydroxylases, enhancing the levels of HIF-1α, it should be approached with caution when it is considered to enhance warm ischemia time and minimize the renal damage subsequent to LPN.

Operating times and bleeding complications in percutaneous nephrolithotomy: a comparison of tract dilation methods in 5,537 patients in the Clinical Research Office of the Endourological Society Percutaneous Nephrolithotomy Global Study

PURPOSE

The study investigated factors that affect operating times and bleeding complications associated with percutaneous nephrolithotomy (PCNL) in the PCNL Global Study.

PATIENTS AND METHODS

All patients who underwent PCNL for primary or secondary treatment of kidney stone indications during the study period (November 2007-December 2009) were eligible for inclusion. PCNL procedures were performed according to local clinical guidelines and practices. Nephrostomy tract dilation was performed using balloon dilation, metal telescopic dilation, or Amplatz serial dilation. Hematologic complications assessed included bleeding rates, transfusion rates, and preoperative and postoperative hematocrit values.

RESULTS

The median operating time with balloon dilation (n=2277) was significantly longer than with telescopic/serial dilation (n=3260) at 94.0 vs 60.0 minutes, respectively (P<0.0001). In the balloon dilation group, there was significantly more bleeding (9.4% vs 6.7%, respectively; P<0.0001) and more transfusions (7.0% vs 4.9%, respectively; P=0.001) compared with the telescopic/serial dilator group. Univariate analysis showed that the probability of bleeding complications was higher with balloon vs telescopic/serial dilation (odds ratio [OR] 1.75; P=0.0001) and larger sheath size (OR 1.42; P=0.0001). By multivariate analysis, sheath size but not dilation method was predictive of bleeding complications. Other significant predictive factors included operating time, stone load, and caseload.

CONCLUSION

This study shows that in PCNL, factors that are associated with bleeding/transfusion include sheath size, operating time, stone load, and caseload.

Beyond mean-field theories with zero-range effective interactions: a way to handle the ultraviolet divergence

Zero-range effective interactions are commonly used in nuclear physics and in other domains to describe many-body systems within the mean-field model. If they are used within a beyond-mean-field framework, contributions to the total energy that display an ultraviolet divergence are found. We propose a general strategy to regularize this divergence and we illustrate it in the case of the second-order corrections to the equation of state (EOS) of uniform symmetric matter. By setting a momentum cutoff Λ, we show that for every (physically meaningful) value of Λ it is possible to determine a new interaction such that the EOS with the second-order corrections reproduces the empirical EOS, with a fit of the same quality as that obtained at the mean-field level.

Ureteroscopic laser treatment of upper urinary tract neoplasms

BACKGROUND

Endoscopic management of upper urinary tract transitional cell carcinoma has assumed an important role in diagnosis and treatment. The introduction of small diameter rigid and flexible ureteroscopes has permitted access to the upper tract. Biopsy techniques have been developed for accurate diagnosis, and the addition of lasers has given the urologists an excellent tool for treatment.

METHODS

Medical literature available relative to the endoscopic laser treatment of upper tract neoplasms has been reviewed.

RESULTS

Ureteroscopic treatment has been characterized by good success with high recurrence rates, both in the upper tract and in the bladder. Bladder recurrence rates are similar to those seen after surgical treatment of upper tract tumors. Surveillance has been ureteroscopic since the other diagnostic options are inadequate. The holmium and neodymium:YAG lasers are the devices most commonly used now for the endoscopic treatment of upper tract tumors.

CONCLUSION

Ureteroscopic treatment of upper tract neoplasms usually with ablation and resection using the neodymium and holmium:YAG lasers is a current acceptable procedure. This should be considered as one of the options in tumor treatment.

Endoscopic management of upper urinary tract urothelial malignancies: broadening experience

Upper urinary tract urothelial tumors reflect a small but growing number of urologic malignancies. The application of progressive endoscopic therapies including ureteroscopic and percutaneous nephroscopic resection and topical chemotherapy have found success, defined as the preservation of the renal unit without malignant progression, in those with low grade lesions. Careful and meticulous diagnostic endoscopy with tissue sampling and cytologic evaluation is key to directing treatment and counseling patients with regard to the risk of recurrence and progression. It is the population with a low grade lesion and negative cytology that are most commonly selected for endsoscopic resection. Those with high grade lesions who opt for endoscopic resection are counseled that this therapy is palliative and can often control local symptoms but is infrequently curative. Surveillance endoscopy post endoscopic resection and topical chemotherapy is essential. With growing surgical experience and improved instrumentation, the complications associated with these and other endoscopic procedures is acceptably low.