Laparoscopic retroperitoneal lymph node dissection in stage A nonseminomatous testis cancer.

Open retroperitoneal lymph node dissection in clinical Stage A testis cancer offers the advantages of definitive staging and high cure rates. Observation is elected in various settings to avoid the morbidity and possible sequelae of this procedure. We present a case report of a new procedure, laparoscopic retroperitoneal lymph node dissection, that decreases hospital stay, recovery time, and morbidity while maintaining the advantages of open retroperitoneal lymph node dissection.

Applications of prostate ultrasonography.

Transrectal ultrasonography of the prostate is a relatively new diagnostic modality being used with increasing frequency in the assessment of prostatic disease. Applications include tumour staging, assisted biopsy and assessment of prostate size. The role of this study for the early detection of carcinoma of the prostate remains controversial and its role in this regard remains to be determined.

The evaluation of urinary protein patterns in a stone-forming animal model using two-dimensional polyacrylamide gel electrophoresis.

The exact role of urinary proteins in kidney stone formation remains an area of controversy. Some investigators believe that urinary proteins are selectively incorporated within urinary calculi and as such have an active role in stone formation. Other investigators believe that urinary proteins are nonspecifically adsorbed into urinary crystals and thus have only a passive role in stone formation. In the current investigation a previously described stone-forming animal model (hyperoxaluric rat) was utilized along with an animal model for renal tubular injury (gentamicin nephrotoxicity) in an effort to clarify the role of urinary proteins in kidney stone formation. Urine specimens were collected before and after the induction of stone formation and after the induction of renal tubular injury. The purified proteins from each urine specimen were separated in two dimensions by electrophoresis resulting in a characteristic "map" of protein spots for each urine specimen. All animals in the stone-forming group had pathologic evidence of early stone formation (diffuse intranephronic calculosis). Early stone formation was consistently associated with a reduction in the excretion of low molecular weight urinary proteins (30,000 dalton and less than 20,000 dalton ranges). Alcian blue staining confirmed the presence of matrix within clumps of intranephronic calcium oxalate crystals. Renal tubular injury was associated with an increase in the excretion of low molecular weight proteins (approximate 20,000 dalton range) consistent with classical tubular proteinuria. These results suggest that low molecular weight urinary proteins are selectively incorporated within the crystalline structure of the stone early during its formation.

Applications of prostate ultrasonography.

Transrectal ultrasonography is a relatively new imaging modality that may be useful in the evaluation and management of patients with prostate cancer. Although cancer may have a characteristic appearance, it cannot always be reliably differentiated from benign conditions. While this technique has clinical applications in staging, monitoring tumor response to therapy, and assisting in biopsy, it is unclear as to whether useful information is obtained in the evaluation of patients with palpable disease. The role of transrectal ultrasonography in patients with nonpalpable disease or as a screening tool has yet to be determined. Other diagnostic tests in conjunction with ultrasound may in the future prove to be useful. Carefully performed prospective investigations with state-of-the-art equipment are still needed to further define the role of this diagnostic modality.

The use of transrectal prostatic ultrasonography in the evaluation of patients with prostatic carcinoma.

Transrectal ultrasonography is a relatively new diagnostic technique that has received much of the same enthusiasm that often is associated with the introduction of other new diagnostic or therapeutic instruments. The study allows for imaging of the prostate but benign conditions often cannot be differentiated reliably from malignant ones. The technique has clinical application in staging, monitoring tumor response to therapy and assisting in biopsy. Its role as a screening study when used either alone or in combination with other diagnostic tests has yet to be determined and well controlled, carefully performed investigations with state of the art instruments probably will help to establish the role of this examination when used for this purpose.