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Biomedical subjects

D P de Klerk

Publications and source records attributed to D P de Klerk.

13 recordsLinked to original sources
PubMed1991

Prostate carcinoma--the value of T stage and grade in predicting metastases and prognosis. A cost-effective approach to clinical staging.

In order to evaluate the initial T stage and tumour grade as predictors of metastatic disease and prognosis in adenocarcinoma of the prostate, 963 patients were reviewed. Of the patients, 41% presented with metastatic disease. Stage T4 tumours were associated with a consistently poor prognosis, and 70% of such patients had demonstrable distant metastases. No patient with TOf local disease had metastases or died of prostate cancer during follow-up. The incidence of metastases was also low in stages T1 and T2. High tumour grade correlated strongly with more advanced disease. Using this information a more cost-effective approach to the staging of prostate carcinoma is proposed.

Adenocarcinoma↗
PubMed1990

[Intravesical BCG as a treatment for superficial and in situ transitional cell carcinoma of the bladder].

Intravesical BCG is already established as effective therapy in the management of superficial bladder cancer. However, varying results have been obtained with different BCG strains; these are ascribed to variations in their immunogenicity. The locally available BCG strain which contains approximately 1.2 x 10(9) colony-forming units per 120 mg was used for intravesical instillation in 27 patients with recurrent superficial transitional cancer of the bladder. Ten of the 13 patients who received BCG prophylactically to reduce or stop recurrencies completed therapy and 7 (70%) were in remission after 1 or 2 courses with a mean follow-up of 2 years. Fourteen patients received BCG therapeutically for in situ carcinoma. Thirteen of these patients completed therapy and 9 (69%) responded favourably after 1 or 2 courses of BCG for a mean follow-up period of 23 months. Adverse effects of the treatment were mild and well tolerated except in a patient who received radiotherapy. Although 21 patients experienced irritable bladder symptoms only 1 discontinued treatment as a direct result. The only other patient in whom treatment had to be stopped, developed severe polyarthritis after 3 instillations. A statistically significant reduction in the number of recurrences (P less than 0.001) was experienced by the patients who received BCG prophylactically. Although this is a very limited study, the locally available BCG strain exhibited therapeutic activity. It is cost-effective and warrants further study.

Administration, Topical↗
PubMed1988

Rectal examination in the detection of prostatic cancer.

Since the aetiology of prostatic cancer is unknown, and therapy for metastatic disease non-curative, a decrease in the mortality rate from this condition can only be achieved by early diagnosis and effective treatment of the primary tumour. For diagnosis of localised cancer no practical alternative exists to rectal palpation. Of 629 cases of prostatic cancer seen at Tygerberg Hospital, the disease had metastasised in 29% of white and 58% of coloured patients at initial diagnosis. Prostatism or urinary retention was the presenting complaint in 74.7% of patients. The letters of referral of 97 patients were examined to determine whether prostatic cancer had been diagnosed by the primary care physician before referral. Rectal examination by the referring physician was recorded or implied in 64.9% of patients, and in those patients who underwent rectal examination before referral prostatic cancer was diagnosed in 54%. These findings imply that the opportunity for early diagnosis of prostatic cancer may be missed in many patients in whom rectal examination by the primary physician is indicated.

Humans↗
PubMed1988

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.

Adolescent↗
PubMed1987

Light-microscopic stereologic analysis of spontaneous and steroid-induced canine prostatic hyperplasia.

A combined light-microscopic and stereologic analysis of the canine prostate was performed under the following experimental conditions: intact and castrated dogs, spontaneous benign prostatic hyperplasia, intact and castrated dogs after treatment with testosterone, 5 alpha-dihydrotestosterone or 3 alpha-androstanediol in combination with estradiol. Regarding the absolute amounts of the glandular and stromal parts of the prostate as well as the glandular cells, no difference was found among the testosterone, 3 alpha-androstanediol and 5 alpha-dihydrotestosterone treated castrated dogs. Treatment with 5 alpha-dihydrotestosterone or 3 alpha-androstanediol in combination with 17 beta-estradiol induced a four-fold increase in glandular and a two-fold increase in stromal tissue. The glandular to stromal tissue ratio equals that found in spontaneous canine hyperplasia, which is indicative of the glandular type of spontaneous canine hyperplasia. Therefore, it can be stated that treatment with 5 alpha-dihydrotestosterone or 3 alpha-androstanediol combined with 17 beta-estradiol not only induces prostatic overgrowth but also leads to prostatic hyperplasia of the glandular type. However, the stereologic analysis of canine prostates following steroid administration shows that canine hyperplasia is primarily a glandular disease, while human benign prostatic hyperplasia shows more stromal activation.

Androstane-3,17-diol↗
PubMed1987

Nephroblastoma in an ovotestis of a true hermaphrodite: a case report.

We describe a patient who presented with a painful mass in the left inguinoscrotal region, gynecomastia, perineal hypospadias with chordee and a bifid scrotum with a small gonad in the right hemiscrotum. At operation the left mass was found to be an ovotestis with hemorrhage in a corpus luteum cyst. A rudimentary uterus and fallopian tube were situated next to the ovotestis. The right gonad also was an ovotestis with a tiny focus of small cell malignancy that was suggestive of nephroblastoma.

Adult↗
PubMed1985

Fluctuations in prostatic glycosaminoglycans during fetal and pubertal growth.

Mesenchymal glycosaminoglycans have been shown to fluctuate during the development of various organs. Prostatic development is an interesting example of organogenesis as it is only at puberty, under androgen influence, that differentiation is completed. We have extracted and quantitated the glycosaminoglycans of human prostates obtained from fetuses, prepubertal, and adult males to determine the changes that occur during prostatic differentiation. The total glycosaminoglycan content per prostate followed the wet weight growth curve. The percentages of heparan sulfate and heparan sulfate sulfation seemed to correlate with prostatic epithelial differentiation. After 25 years of age prostatic glycosaminoglycan concentrations tend toward the glycosaminoglycan ratios typical of benign prostatic hyperplasia.

Adolescent↗
PubMed1985

The gubernaculum during testicular descent in the pig fetus.

The role of the gubernaculum during testicular descent was investigated in a study of 119 male pig fetuses obtained at gestational ages ranging from 53 to 116 days. Histologically the gubernaculum was shown to consist of primitive mesenchymal cells with an abundant intercellular material containing glycosaminoglycans (mucopolysaccharides). Rapid descent of the testis through the inguinal canal occurred between 77 and 88 days' gestation, while sustained but slower descent occurred up to 109 days. There was a dramatic increase in the total wet mass of the gubernaculum at the commencement of rapid testicular descent from 77 to 81 days, and a further increase in wet mass during sustained descent from 91 to 95 days. In the period just prior to rapid testicular descent (day 74-81) the percentage increase in the water content of the gubernaculum was larger than the percentage increase in the dry mass. After descent of the testis (day 95-109) there was a decrease in the water content, but also an increase in the dry mass of the gubernaculum. No comparable increase in the water content of umbilical cord or striated muscle tissue occurred during the period of testicular descent. Thus, the marked swelling of the gubernaculum, which dilates the inguinal canal and scrotum and may possibly exert traction on the testis by the force of its expansion, is due largely to an accumulation of water by the gubernaculum. This process may be mediated by the intercellular glycosaminoglycans, since these poly-anionic macromolecules are known to have a large hydrodynamic volume and can act as a "water trap."

Animals↗
PubMed1983

Stab wounds associated with hematuria--a review of 67 cases.

The clinical records of 67 patients who underwent surgical exploration for stab wounds associated with hematuria were reviewed in an attempt to evaluate the need for mandatory operation and to define criteria for possible nonoperative of such cases. Minor renal injuries without associated intra-abdominal lacerations were found in 61 per cent of the patients. Delayed renal hemorrhage occurred in 15 per cent of the patients despite early exploration, suture and drainage of the kidney, and antibiotic prophylaxis. Of 7 nephrectomies 5 were performed for secondary hemorrhage. Postoperative pulmonary complications arose in 28 per cent of the patients. A policy of mandatory operation on all patients with stab wounds and hematuria led to apparently needless surgery in 61 per cent of the patients in this series. Retrospective analysis revealed that the rate of probably unnecessary operations could have been reduced to 24 per cent by selecting for operation only those patients with signs of severe hemorrhage, associated intra-abdominal injury or major extravasation of contrast material on excretory urography.

Adolescent↗
PubMed1979

Relationship of seminal volume to size and disease of the prostate in the beagle.

The seminal volume of young adult Beagles was correlated with the size of and disease in their prostates. The ejaculate volume of naturally collected semen increased in a linear manner with prostatic weight in dogs with normal or glandular hyperplastic prostates. This correlation was not observed in the dogs with cystic hyperplasia, in which there was a reduction in volume of 50% in the semen produced for each gram of prostate. There were no significant differences in other seminal characteristics regardless of prostatic size of disease.

Animals↗
PubMed1977

Multicystic dysplastic kidney.

We reviewed 29 cases of congenital multicystic dysplastic kidneys. Isolated renal pelvic atresia has an excellent prognosis but lower ureteral atresias are associated with a high incidence of contralateral renal disease and have a worse prognosis.

Abnormalities, Multiple↗
PubMed1975

Adenomatoid tumors (mesothelioma) of testicular and paratesticular tissue.

Fourteen cases of adenomatoid tumor of the paratesticular tissues are presented. The clinical presentation and histopathologic aspects are discussed. Two hundred and three cases from the English literature are reviewed, and the clinical presentation, natural history, malignant changes, histopathologic aspects, and possible hormonal associations are discussed.

Adult↗