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.     

Polyglactin 910 implants in muscle revision surgery for the reconstruction of physiologic limits in Tenon's capsule

Iatrogenic damage to the orbital fascial system during strabismus surgery may lead to adherences with resulting problems of motility. To prevent new adherences in revisional surgery, several materials were tried, with varying degrees of success. The authors tested Polyglactin 910, popular as a suture material in strabismus surgery, in the form of a net. The material is hydrolytically soluble. Since the tissue response is finished before dissolution of the implant, it seemed that Polyglactin would be a suitable barrier to the formation of adhesions in Tenon's capsule. The implant was applied in 11 patients, some of whom had already undergone several strabismus operations and had adhesions at the surgical site. In one case the implant was used in a primary procedure. In one patient revisional surgery was needed four weeks after surgery because of overeffect, and this provided an opportunity to investigate the implanted area histologically.     

Neuroprostheses in the management of incontinence in myelomeningocele patients

A 16-year-old boy and a 17-year-old girl underwent successful closure of the meningomyelocele defect in childhood but they continued to suffer incontinence of stool and urine. After a 5-day trial with percutaneous electrostimulation of the pudendal nerve both patients received permanent neuroprosthetic implants. They became completely continent of stool and exhibited greater than 90% improvement in urinary control. These patients demonstrate that there is a small subset of meningomyelocele patients who, despite absence of spontaneous reflex tonus in the urinary and bowel sphincters, nevertheless have preserved motor capabilities.