Biomedical subjects

David Schulsinger

Publications and source records attributed to David Schulsinger.

4 recordsLinked to original sources

PubMed2004

Increase in scrotal temperature in laptop computer users.

BACKGROUND: Scrotal hyperthermia has been identified as a risk factor for male infertility. Laptop computers (LC) have become part of a contemporary lifestyle and have gained popularity among the younger population of reproductive age. LC are known to reach high internal operating temperatures. We evaluated the thermal effect of LC on the scrotum. METHODS: Right and left scrotal temperature (ScT) was measured in 29 healthy volunteers in two separate 60 min sessions. ScT was recorded from thermocouples on a digital datalogger every 3 min with the working LC in a laptop position and in the same sitting position with approximated thighs without LC. RESULTS: ScT increased significantly on the right and left side in the group with working LC (2.8 degrees C and 2.6 degrees C, respectively; P<0001) and without LC (2.1 degrees C, P<0.0001). However, ScT elevation with working LC was significantly higher (P<0.0001). CONCLUSIONS: Working LC in a laptop position causes significant ScT elevation as a result of heat exposure and posture-related effects. Long-term exposure to LC-related repetitive transient scrotal hyperthermia is a modern lifestyle feature that may have a negative impact upon spermatogenesis, specifically in teenage boys and young men. Further studies of such thermal effects on male reproductive health are warranted.

Adult↗

PubMed2004

Endoscopic treatment of bladder calculi in post-renal transplant patients: a 10-year experience.

BACKGROUND AND PURPOSE: Urinary calculus formation following renal transplantation is an uncommon phenomenon. As a result of the growing number of renal transplants performed and the greater graft survival, there has been increased awareness of transplant-related complications, one of which is calculus formation. We report our experience in the management of bladder calculi after renal transplantation. PATIENTS AND METHODS: We retrospectively reviewed the charts of 500 consecutive renal transplant patients from 1992 through 2002 and encountered 7 who had bladder calculi postoperatively. Ureteroneocystostomy had been performed using polyglactic acid suture. Bladder calculi were treated endoscopically by litholapaxy, electrohydraulic lithotripsy (EHL), or holmium:YAG laser lithotripsy. RESULTS: Three calculi were found incidentally at the time of stent removal, and the others were associated with hematuria (43%), urinary tract infection (14%), or irritative voiding symptoms (14%). Eighty-six percent of the calculi were close to the allograft ureteral orifice. CONCLUSION: While various forms of lithotripsy were employed in treating bladder calculi, Hol:YAG laser lithotripsy appeared to be both efficacious and safe. Both EHL and litholapaxy were complicated by mucosal bleeding necessitating Bugbee fulguration. Holmium:YAG laser lithotripsy was not associated with mucosal bleeding, and fulguration was not required near the allograft ureteral orifice. In addition, ureteral stenting is not required. Bladder calculi may form over both absorbable and nonabsorbable suture material, and the ideal suture for the ureteroneocystostomy has yet to be found. Until then, the Hol:YAG laser should be the lithotrite of choice for bladder calculi following renal transplantation.

Adult↗

PubMed2004

When can persistent hydroureteronephrosis in posterior urethral valve disease be considered residual stretching?

PURPOSE: Persistent hydroureteronephrosis (HUN) is often seen in boys with a history of a posterior urethral valve even years after valve ablation and it is often assumed to represent residual stretching. We determined the association of HUN with urodynamic abnormalities, the effect on HUN of treating these abnormalities and when persistent HUN could be considered residual stretching. MATERIALS AND METHODS: Of 71 patients with a posterior urethral valve evaluated after valve ablation 20 (28.2%) had persistent HUN in a total of 32 renal units (RUs). The degree of HUN was graded as mild, moderate or severe. Videourodynamics were performed in all patients with persistent HUN and abnormal urodynamic findings were aggressively treated. HUN was then reassessed and categorized as resolved, improved or unchanged. RESULTS: Abnormal urodynamic findings, primarily hypocompliance and instability, were noted in all 20 patients with HUN. All patients compliant with treatment showed dramatic improvement or complete resolution of abnormal urodynamic parameters. The 32 RUs with persistent HUN were initially graded as mild (8), moderate (13) and severe (11). HUN resolved in 15 RUs and improved to a lower grade in 11 in 26 of the 27 RUs (96.3%) in the 17 patients compliant with treatment. The 3 boys (5 RUs) who were noncompliant with treatment had neither decreased HUN nor improved urodynamic parameters. The 12 of 27 RUs (44.4%) in the treatment group in which HUN failed to resolve completely had no distal ureteral obstruction or identifiable persistent urodynamic abnormality and, thus, they can be labeled as having residual stretching. CONCLUSIONS: Persistent HUN following valve ablation should not be considered residual dilatation until a thorough urodynamic evaluation has been done and any abnormal parameters are addressed. With correction of these abnormal parameters one can expect significant lessening of HUN and hopefully improved long-term preservation of renal function.

Child↗

PubMed2003

Renal hemodynamic and ureteral pressure changes in response to ureteral obstruction: the role of nitric oxide.

PURPOSE: Triphasic changes in renal blood flow and ureteral pressure after unilateral ureteral obstruction have long been known. The contribution of nitric oxide to the decline in renal blood flow and ureteral pressure in unilateral ureteral obstruction was studied in this model using arginine infusion and by studying the effect of 2 inhibitors of nitric oxide synthase (NOS). MATERIALS AND METHODS: Left ureteral obstruction was created in dogs. Renal blood flow and ureteral pressure were monitored. Groups 1 to 4 underwent unilateral ureteral obstruction and group 5 dogs underwent sham operation. Groups 2 to 5 received an infusion of arginine at hour 18 of obstruction that was sustained for 1 hour. In addition, NOS inhibitors were administered to dogs in groups 3 (N-monomethyl-L-arginine) and 4 (triamcinolone diacetate). RESULTS: Arginine administration at 18 hours of obstruction caused a significant increase in renal blood flow and ureteral pressure compared to sham operated animals. Triamcinolone diacetate eliminated the increase in renal blood flow and ureteral pressure, whereas N-monomethyl-L-arginine did not, reflecting the competitive nature of its inhibition of NOS. CONCLUSIONS: Arginine infusion 18 hours after unilateral ureteral obstruction led to increases in renal blood flow and ureteral pressure that were not seen in control animals. These results suggest that the nitric oxide system of the kidney is activated in unilateral ureteral obstruction. Since the addition of arginine is accompanied by an increase in renal blood flow and ureteral pressure, it further suggests that a lack of availability of substrate for NOS may explain the decrease in renal blood flow and ureteral pressure in obstruction. Providing substrate may be a way of maintaining renal blood flow in unilateral ureteral obstruction.

Animals↗