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Biomedical subjects

C F Heyns

Publications and source records attributed to C F Heyns.

At least 37 records · Page 2Linked to original sources
PubMed1996

DNA fingerprint detection of somatic mutations in benign prostatic hyperplasia and prostatic adenocarcinoma.

Genetic alterations within diseased prostate tissue were analysed by genomic DNA fingerprinting using a minisatellite probe (lambda 33.6), a simple repetitive oligonucleotide probe (GTG)5, and an additional human multilocus probe (pV47-2). In prostatic adenocarcinoma, somatic mutations were detected in 77% of the samples compared with 38% of the benign prostatic hyperplasia samples. No correlation was evident with either the tissue histopathology or the grading or staging classification of the malignant tissue. Because one of the probes (pV47-2) did not demonstrate any changes in the tumour tissue, and because the probes exhibited specificity for different regions of the genome, it is possible to conclude that mutations occur widely throughout the genome, perhaps with the exception of certain domains. The results suggest that somatic mutations accompany the development of both benign and malignant pathologies of the prostate. Furthermore, benign prostatic hyperplasia should be considered as a risk indicator for processes leading to prostatic adenocarcinoma.

Adenocarcinoma↗
PubMed1996

Polymerase chain reaction in the diagnosis of urinary tract tuberculosis.

The polymerase chain reaction (PCR) is a technique that can be used to amplify a specific DNA genomic sequence, whereby the presence of an extremely small number of bacteria can be detected. The high sensitivity of PCR is particularly useful in paucibacillary situations such as non-pulmonary tuberculosis (TB). The aims of the present study were to establish a PCR assay for the rapid detection of Mycobacterium tuberculosis (MTb) in urine, to compare the sensitivity of PCR with routine culture technique (Bactec) and to determine the optimal type of urine specimen for PCR detection of MTb. In the first phase of the study, a total of 92 urine specimens were collected from 83 patients with suspected urinary tract TB. Two urine specimens in 2 patients were positive for TB by both PCR and Bactec, while 90 specimens from 81 patients were negative by both methods. Inhibition of PCR was present in nine urine specimens (10%). In the second phase of the study, a further seven patients were selected for intensive investigation to determine the optimal urine sampling for PCR detection of MTb. The conclusions of the study are that PCR can provide much faster confirmation of urinary TB (within 24-48 h) than Bactec urine culture (which may take several weeks). About 10% of urine specimens could not be evaluated by PCR due to the presence of inhibitory substances of unknown nature. MTb organisms were found to be excreted intermittently in the urine of infected patients, and single specimens were more likely to be false negative than a 24-h sample. The best method appeared to be the concentration of a large volume of urine, for instance 11 concentrated to 2 ml.

Adult↗
PubMed1996

Bladder cancer in various population groups in the greater Durban area of KwaZulu-Natal, South Africa.

OBJECTIVE: To study the incidence of different histological types of bladder cancer in various racial groups living within the same geographical region. PATIENTS AND METHODS: The study included 615 new patients with bladder cancer seen at three Provincial hospitals in Durban from January 1980 to January 1990. The patients were classified as Caucasian (white people of European descent). African (indigenous black people), Asian (people originating from the Indian subcontinent) or Coloured (people of mixed race). The bladder tumours were classified according to standard histopathological criteria as transitional cell carcinoma, adenocarcinoma or sarcoma. Mixed tumours consisted of both carcinomatous and sarcomatous or undifferentiated elements. RESULTS: Transitional cell carcinoma constituted 95% of the cancers in Caucasians, compared with only 30% in Africans, whereas squamous cell carcinoma occurred in 53% of the African patients, but in only 2% of the Caucasians. In Asian patients, 75% of the tumours were transitional cell and 18% were squamous cell carcinoma, whereas in Coloureds 82% were transitional cell and 9% squamous cell carcinoma. Undifferentiated carcinoma occurred in 8% of African and only 1% of Caucasian patients, whereas adenocarcinoma, mixed tumours and sarcoma occurred in 9% of African patients and only 2% of Caucasian patients. Ova of Schistosoma haematobium were seen in microscopic sections of the bladder tumour in 85% of the patients with squamous cell carcinoma, in 50% of those with undifferentiated tumours and adenocarcinoma, in 17% of those with mixed tumours or sarcoma, and in only 10% of the patients with transitional cell carcinoma. At presentation, African patients were a mean of > 20 years younger than Caucasians. In African patients with squamous cell carcinoma, 90% had stage T3 or T4 disease at presentation, whereas in Caucasian patients with transitional cell carcinoma 76% had stage T1 or T2 disease at presentation. From the study group, it appears that bladder cancer is about six times more common in Caucasians than in Africans. However, the value for Caucasian patients with bladder cancer probably underestimates the true value by about five times, so that bladder cancer in the greater Durban area may be as much as 30 times more common in Caucasians than in Africans. CONCLUSION: In African patients, endemic Schistosomiasis appears to be related to a high incidence of not only squamous cell carcinoma, but also undifferentiated tumours and adenocarcinoma of the bladder. The effective management of squamous cell carcinoma of the bladder in African patients will depend on the eradication of Schistosomiasis and the early detection of bladder cancer at a stage when it may still be cured by radical treatment.

Adenocarcinoma↗
PubMed1996

Luteinizing hormone, follicle-stimulating hormone, testosterone and dihydrotestosterone during testicular descent in the pig fetus.

To investigate the relationship between gonadotrophins, androgens and testicular descent in the pig fetus, serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and serum concentrations and testicular content of testosterone (T) and 5 alpha-dihydrotestosterone (DHT) were determined by radioimmunoassay in 95 fetuses (48 males, 47 females) between Day 60 and Day 90 post coitum (p.c.). The testes were descended in 0% of fetuses at Day 60, 8% of fetuses at Day 70, 40% of fetuses at Day 80 and 87% of fetuses at Day 90 p.c. There was a significant increase in mean serum concentrations of LH in both male and female fetuses from Day 60 to Day 90, with a significant difference in mean serum concentrations of LH between male fetuses with a body mass < 350 g (4% of testes descended) and those with a body mass > 450 g (87% of testes descended), but not between male and female fetuses < 350 g or > 450 g in body mass. There was no significant difference in mean serum concentrations of FSH between male and female fetuses. Mean serum concentrations of T were significantly higher in male fetuses at Day 60 than in those at Days 70-90, with no significant difference in serum concentrations of DHT from Day 60 to Day 90 p.c. Testicular content of T and DHT showed a non-linear increase from Day 60 to Day 90 p.c. Although the serum concentration of T is elevated before, and decreased during, the period of descent, the testicular content of T and DHT increases during the period of descent, indicating that serum concentrations of LH and FSH may have an indirect effect on descent by stimulating testicular androgen synthesis.

Dihydrotestosterone↗
PubMed1996

Infiltrating transitional cell carcinoma of the bladder--treatment results.

This is a review of the treatment results of 100 consecutive patients with infiltrating transitional cell carcinoma of the bladder who underwent cystectomy at Tygerberg Hospital between 1978 and 1989. Radiotherapy was given pre-operatively in 39% and postoperatively in 15%, and systemic chemotherapy was used postoperatively in 12% of the patients. Follow-up was available in 81% of patients, with a mean of 40.8 months (range 1-145 months). The estimated overall 5-year survival rate was approximately 70%, which compares favourably with the 5-year survival rate reported in other series of transitional cell bladder carcinoma treated with radical cystectomy (30-82%). There was a statistically significant decrease in overall 5-year survival in patients with more locally advanced tumours, and in patients with a higher pathological stage relative to clinical tumour stage (upstaging) than in those with a lower pathological stage relative to clinical tumour stage (downstaging). There was no statistically significant difference in overall survival between patient groups aged < 60 and > 70 years, between patients with and without pre-operative radiotherapy, between groups with different tumour grades, between those with and without carcinoma in situ, and between those with and without pelvic lymph node metastases.

Adult↗
PubMed1995

Proliferation of gubernaculum cells induced by a substance of low molecular mass obtained from fetal pig testes.

To investigate the hormonal control of gubernacular development and testicular descent we determined the effect of gonadal extracts and various hormones on the proliferation of gubernaculum cell cultures established from 55 male pig fetuses obtained at 60 to 90 days' gestation. The percentage of descended testes was 0 at 60, 8% at 70, 40% at 80 and 87% at 90 days' gestation. Significant proliferation (as measured by [3H]thymidine incorporation) of gubernaculum, but not 3T3, cells was induced by crude testicular but not ovarian extracts, and was directly related to its protein concentration. Significant proliferation of gubernaculum cells was induced by low molecular mass (< 30 kD) testicular, but not by high molecular mass (> 30 kD), testicular and low or high molecular mass ovarian extracts obtained by centrifugation of crude extracts in microspin filter membranes with a molecular cut-off mass of 30 kD. Proliferation of gubernaculum cells induced by the low molecular mass (<30 kD) testicular extract was significantly greater than that stimulated by testosterone or dihydrotestosterone. Polyacrylamide gel electrophoresis demonstrated a unique protein band at approximately 26 kD in the crude and low molecular mass testicular, but not in the ovarian, extracts. It is possible that this represents a novel peptide hormone secreted by the fetal testis, responsible for stimulating the growth of the gubernaculum, thereby mediating testicular descent.

Animals↗
PubMed1995

Are neuroendocrine cells of practical value as an independent prognostic parameter in prostate cancer?

OBJECTIVE: To assess whether the presence of neuroendocrine (NE) cells is of value as an independent indicator of poor prognosis in patients with prostate carcinoma. PATIENTS AND METHODS: A series of 160 consecutive patients with prostate carcinoma was studied retrospectively. In 120 there was sufficient tissue for review and to perform immunoperoxidase stains for neuron specific enolase (NSE) and chromogranin A (CGA). All patients had a potential follow-up of at least 5 years. RESULTS: Five-year survival was poorer for patients with a high tumour grade and stage at presentation compared to those with a lower grade and stage. NE cells were more common in higher grade and stage disease, but 5-year survival did not differ significantly between patients with NE cell positive and negative tumours. CONCLUSION: NE cells are of no practical value as an independent prognostic indicator in patients with prostatic adenocarcinoma.

Adenocarcinoma↗
PubMed1995

Changing patterns of prostatectomy in Scotland: 1971-1989.

Analysis of 81,374 prostatectomies performed in Scotland between 1971 and 1989 showed that the annual prostatectomy rate (per 100,000 men) increased 3-fold for procedures performed by urologists, but remained static for general surgeons. In 1971, transurethral prostatectomy comprised 16% of all prostatectomies performed by general surgeons and 55% of those performed by urologists, but by 1989 it comprised 93% of prostatectomies performed by general surgeons and 96.5% of those performed by urologists. The relative increase in the annual number of prostatectomies was greatest (2.61) in the older age group (80-89 years) and smallest (1.76) in the younger age group (60-69 years). The relative increase in the age-specific prostatectomy rate was greatest (1.79) in the youngest age group (50-59 years) and smallest (1.54) in the oldest age group (80-89 years). This indicates that the increase in the annual number of prostatectomies performed in the older age groups is largely the result of an increase in the number of elderly men in the population, but this is compounded by an expansion of the indications for prostatectomy in all age groups.

Age Factors↗
PubMed1995

Surgical complications of radical cystectomy in a teaching hospital.

We reviewed the surgical complications in 112 consecutive patients who had undergone radical cystectomy for bladder cancer at Tygerberg Hospital between 1978 and 1989. The cystectomies were performed by a total of 16 surgeons, of whom 1 (A) performed 30 and assisted at 2, 1 (B) performed 26 and assisted at 4, 2 (C + D) performed 27 and assisted at 16, and 12 (E-P) performed 29 and assisted at 46. Pre-operative radiotherapy was given in 37% of cases and intravesical chemotherapy in 25%. Major coexisting medical problems were present in 60%. The overall peri-operative mortality rate was 11%, but the rate was significantly lower (3%) in the group of patients operated on by surgeon A than in those operated on by surgeons E-P (21%). Major early postoperative complications occurred in 17% of the patients and major late complications in 25%. There were no significant differences between the different surgical groups in early and late complication rates. Peri-operative mortality and major early complications were significantly increased in patients aged over 71 years compared with those aged under 60 years. Peri-operative mortality was significantly increased in patients who had not received pre-operative radiotherapy compared with those who had done so. The presence of major coexistent medical problems did not significantly affect the rates of peri-operative mortality or major early or late surgical complications. Peri-operative mortality was lower in patients with T0-1 tumours than in those with T2-4 tumours, but the stage did not affect the incidence of major early or late surgical complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Absence of 5 alpha-reductase activity in the gubernaculum during descent of the fetal pig testis.

To evaluate the hypothesis that testicular descent is mediated by the action of high local concentrations of dihydrotestosterone in the gubernaculum, testis, or epididymis, we obtained tissues from 30 male pig fetuses between 63 and 101 days of gestation. We assayed the 5 alpha-reductase activity in homogenates of pooled tissue by following the conversion of (3H)testosterone to (3H)dihydrotestosterone. The 5 alpha-reductase activity in the urethra and prostate increased prior to and during, but decreased after, the period of testicular descent. The 5 alpha-reductase activity in the gubernaculum remained constant throughout gestation and was not significantly higher than the background activity found in umbilical cord, testis plus epididymis, striated thigh muscle and heat inactivated samples of prostate and urethra. Prior to testicular descent, the 5 alpha-reductase activity was approximately 60 to 300 times higher in the urethra than in the gubernaculum, and approximately 20 to 55 times higher in the prostate than in the gubernaculum. These findings indicate that local conversion of testosterone to dihydrotestosterone in the gubernaculum or epididymis does not play a role in the mediation of testicular descent in the pig fetus.

Animals↗
PubMed1993

Peripheral blood lymphocyte response in patients with superficial transitional cell carcinoma of the bladder treated with intravesical Bacillus Calmette-Guérin--a useful marker of response?

Intravesical instillation of Bacillus Calmette-Guérin (BCG) offers safe and effective short-term/long-term treatment for superficial transitional cell carcinoma (TCC) and TCC in situ of the bladder. However, 17 to 42% of patients may experience recurrence in spite of this therapy and a marker of effective treatment is of paramount importance. In this study the in vitro response of peripheral blood lymphocytes (PBL) to BCG was analysed in 10 patients with superficial TCC and TCC in situ before and during BCG instillations. The in vitro response of PBL to BCG, expressed as a stimulatory index (SI), revealed that 6 patients had a SI > 5 and 4 patients had a SI < 5. None of the former patients had recurrence of TCC during a mean follow-up of 17 months, while all of the latter patients experienced recurrence of TCC within 9 months. It was concluded that the in vitro response of PBL to BCG may be used as a marker of response to intravesical BCG treatment.

Adult↗
PubMed1993

Intra-operative myocardial ischaemia detected by biplane transoesophageal echocardiography during transurethral prostatectomy.

Recent studies have shown an increased late mortality rate due to cardiovascular causes after transurethral compared with open prostatectomy. This has been linked to the demonstration of haemodynamic changes during transurethral prostatectomy, which may cause ischaemic myocardial injury. We used transoesophageal echocardiography (currently the most sensitive modality for detecting myocardial ischaemia) to study 26 patients during prostatectomy under general anaesthesia. Evidence of myocardial ischaemia (as shown by the development of new regional wall motion abnormalities of the left ventricle) occurred in 4 of 22 patients during transurethral and in 3 of 4 patients during retropubic prostatectomy. An intra-operative fall in systolic as well as diastolic blood pressure occurred in 21 of 22 patients during the transurethral procedure and in all 4 patients during retropubic prostatectomy. The duration of anaesthesia and the operation, and the intra-operative blood loss did not differ significantly between patients with and without evidence of intra-operative myocardial ischaemia. However, the maximum intra-operative fall in systolic and diastolic blood pressure, as well as the mass of the prostatic tissue removed, were significantly greater in patients with than in those without evidence of intra-operative myocardial ischaemia, suggesting that the latter may be related to the extent of surgery and the degree of intraoperative hypotension. In this study, 7 of 26 patients (27%) showed evidence of myocardial ischaemia during prostatectomy. However, it remains difficult to explain why intra-operative myocardial ischaemia should result in an increased cardiovascular mortality rate several years after the operation.

Aged↗
PubMed1992

Increasing role of angiography and segmental artery embolization in the management of renal stab wounds.

During a 5-year period 93 patients with stab wounds involving the upper urinary tract were treated. Of these patients 79 were treated initially at our department (group 1) and 14 were referred with complications after initial treatment elsewhere (group 2). In group 1, 26 patients (33%) were selected for surgery on the basis of signs of severe blood loss or associated intra-abdominal injury, or major abnormality on the excretory urogram. At operation a major renal injury and/or associated intra-abdominal laceration was found in 23 patients (88%) and nephrectomy was required in 7 (27%) of them. Nonoperative management was selected in 53 patients (67%) in group 1 and secondary hemorrhage occurred in 8 (15%). Of the patients in group 2, 4 had undergone an operation elsewhere and 10 had been managed nonoperatively. Renal arteriography was performed in 14 patients who had been managed nonoperatively (6 from group 1 and 8 from group 2) and demonstrated a traumatic pseudoaneurysm in 6, an arteriovenous fistula in 5 and no large vessel injury in 3. Selective embolization of the involved segmental artery was successful in 9 of 11 patients (82%) when angiography showed a vascular lesion. This study demonstrates the increasingly important role of renal angiography and selective embolization in the selective nonoperative management of patients with stab wounds of the kidney.

Adolescent↗
PubMed1992

Selective surgical management of renal stab wounds.

Patients with stab wounds and haematuria were selected for surgical exploration if they had signs of severe blood loss, an associated intra-abdominal laceration or major abnormality on the intravenous urogram (IVU). Patients without these signs were selected for non-operative management, consisting of bed rest, an intravenous antibiotic for 24 h and regular observation. Of 95 patients, 60 (63%) were selected for non-operative management (Group 1) and 35 (37%) were selected for primary surgical exploration (Group 2). At surgery in Group 2, a major renal injury and/or associated intra-abdominal laceration was found in 31 patients. Thus a probably unnecessary operation was performed in only 4 patients (4% of the whole group of 95 patients). Renal complications occurred in 12 of the 60 patients (20%) in Group 1 and consisted mainly of secondary haemorrhage caused by an arteriovenous fistula (AVF) or pseudo-aneurysm. Management of the renal complications included segmental artery embolisation in 6, nephrectomy in 2, heminephrectomy in 1, open surgical ligation of an AVF in 1 and spontaneous resolution in 2 patients. The mean period of hospitalisation was significantly shorter in Group 1 (6.1 days) than in Group 2 patients (9.9 days). Comparing the Group 1 patients who developed renal complications with those who did not, we would recommend more aggressive selection for surgery of those patients exhibiting clinical signs of shock, a fall in haemoglobin during observation, a palpable abdominal mass, a haemothorax and/or pneumothorax ipsilateral to the renal injury, and IVU signs of extravasation, non-function, delayed excretion or hydroureteronephrosis due to blood clots.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Three-dimensional computed tomographic imaging of the pelvicaliceal system: analysis of factors influencing image quality.

We analyzed 3-dimensional (3D) computed tomographic images of the pelvicaliceal system obtained in 25 patients after opacification of the collecting system by retrograde ureteric or intravenous (IV) infusion of sodium iothalamate. 3D images were reconstructed using the data from nonoverlapping 5-mm sections taken on an Elscint 2400 scanner. Factors contributing to poor image quality were: artifacts caused by contrast in the collecting tubules, underfilling or overdistension of the pelvicaliceal system with contrast, movement of the patient and severe hydronephrosis. Satisfactory 3D images of the pelvicaliceal system can be obtained by retrograde ureteric infusion of 5% w/v sodium iothalamate at 20 cm H2O, or by IV injection of 50 ml of 70% w/v sodium iothalamate. Abdominal compression should be applied 10-15 min after the IV injection of contrast, and the computed tomographic examination should commence 20-30 min after the injection. It is imperative that the patient lie completely still and breathe normally to avoid movement of the kidneys. 3D computed tomographic imaging of the pelvicaliceal system may become a valuable adjunct to the preoperative planning and performance of percutaneous nephrolithotomy.

Adolescent↗