Visual disturbances, serum glycine levels and transurethral resection of the prostate

Transient visual disturbances have been noted in patients undergoing transurethral resection of the prostate. It has been suggested recently that these visual aberrations were secondary to high serum concentrations of glycine from the intravasation of irrigant solutions used during the procedure. We prospectively studied visual acuity, serum electrolytes, glucose, ammonia and glycine concentrations in 18 patients undergoing transurethral resection of the prostate. Of our patient population 22% experienced significant decreases in visual acuity. We found that all patients had significantly elevated serum glycine concentrations but that there was no correlation of visual symptomatology with serum electrolyte or glucose concentrations. Our data further suggest that impeded metabolism of glycine may be more important than the absolute serum concentration in symptomatic patients.     

Functional evaluation of sacral nerve root integrity. Report of a technique

We report our technique of direct stimulation of the sacral roots governing voiding by which the functional and anatomic integrity of these nerve roots can be assessed in patients with voiding dysfunction. The muscular responses to stimulation of each sacral root are described, as are the landmarks and approach used to achieve stimulation.     

Percutaneous nephrolithotomy. Experience with renal and proximal ureteral calculi at Tygerberg Hospital

Percutaneous nephrolithotomy (PCN) enables the urologist to remove upper urinary tract stones through a percutaneous nephrostomy tract. The principal advantages of PCN are the low morbidity, shortened hospital stay and rapid recovery. Percutaneous puncture failed in 5 (11%) of the first 44 patients with upper tract urolithiasis treated by PCN at Tygerberg Hospital. In 35 patients (80%) PCN cleared the kidney of stones but in 4 patients (9%) all stone fragments were not removed during the procedure. If the puncture and dilatation was successful, then 90% of patients were stone-free after PCN. Complications were minimal except for a diabetic who died of septicaemia. PCN is an alternative to open renal surgery in the management of most upper urinary tract stones. The technique is readily mastered by any urologist experienced in endoscopic surgery.     

The Ammann test, attempt at electrophysiologic verification

The Ammann filter test is a subjective method of differentiating functional amblyopia from the organic type. An attempt was made to verify this subjective method by means of visual evoked responses. Good correlation was found with the results described in the literature, obtained by psychophysical examination.     

Tumor progression and metastasis

The heterogeneity of cells capable of metastasation has proved to be the greatest obstacle to successful treatment or to prevention of metastatic diseases. This variety appears to be attributable to processes of selection. Cytobiological investigations which are helpful in casting some light at selective mechanisms of metastasation may, perhaps, make substantive contributions to cancer therapy.     

Two different proteoheparan sulfate species are synthesized by bovine corneal endothelial cells

Cultured bovine corneal endothelial cells were labeled with either [35S]sulfate or a combination of [3H]glucosamine and [35S]methionine. The medium proteoheparan sulfate (HS-PG) and cell-associated HS-PG were isolated and identified as heparan sulfate-containing proteoglycans by the susceptibility of their glycosaminoglycan component to specific enzymatic and chemical degradation. The native medium HS-PG has an apparent Mr of about 300,000 and an Mr of its protein core of 64,000, while the native cell-associated HS-PG had a lower molecular weight (approx. 100,000) and an Mr of its protein core of 33,000. The protein core of both HS-PG types consisted of a single polypeptide chain. After beta-elimination reaction of the native HS-PGs the resulting heparan sulfate side chains of medium HS-PG had an Mr of about 60,000, and those of cell-associated HS-PG an Mr of about 30,000. The different molecular parameters of medium HS-PG and cell-associated HS-PG refer to different functional roles. The medium HS-PG secreted by the endothelial cells is regarded as a metabolic precursor of the Descemet's membrane, while the cell-associated HS-PG might represent a cell membrane-integrated proteoglycan.