A van der Merwe

Prostate cancer among different racial groups in the Western Cape: Presenting features and management

OBJECTIVES We aimed to compare the presenting features and management of prostate cancer among different racial groups. PATIENTS AND METHODS We studied all patients diagnosed with prostate cancer at the Urological Oncology Clinic, Tygerberg Hospital, from January 1995 to December 2005. Most presented symptomatically as PSA screening is not readily available in the referral area of the hospital. Race was self-defined as white, coloured or black. Statistical analysis was performed using Students t-test or Fishers exact test, where appropriate. A two-tailed p-value <0.05 was accepted as statistically significant. RESULTS There were 901 patients: 291 (32.3%) white, 539 (59.8%) coloured and 71 (7.9%) black. Mean age at presentation was significantly higher in the white than the coloured and black groups (69.7, 67.9 and 68.9 years, respectively). Grade 1 adenocarcinoma was most common in the white (37%) and coloured groups (38%), and grade 2 was most common in the black group (39%). There was a significantly lower percentage of patients with T3-4 disease at diagnosis in the white group (47%) than the coloured (61%) and black (62%) groups. Mean serum PSA at diagnosis was significantly higher in the black than the coloured and white groups (766.1,673.3 and 196.1 ng/ml, respectively). Potentially curative therapy (radical prostatectomy or radiotherapy) was chosen by 31% of white, 23% of coloured and only 12% of black patients. The mean duration of follow-up was significantly shorter in the black than in the white or coloured groups (24.0, 31.5 and 35.0 months, respectively). CONCLUSIONS Black men presented with higher grade and stage disease and higher serum PSA, received potentially curative treatment less often, and had a shorter follow-up (probably owing to shorter survival) than the white and coloured groups. Greater prostate cancer awareness and education among patients and physicians and more widespread use of PSA screening of presymptomatic men at risk of prostate cancer is needed.

Evaluation of a Hemostatic Sponge (TachoSil®) for Sealing of the Renal Collecting System in a Porcine Laparoscopic Partial Nephrectomy Survival Model

OBJECTIVE The objective of this study was to evaluate the efficacy of TachoSil (Nycomed UK, Oxford, Buckinghamshire, UK), a hemostatic sponge, to seal major collecting system injuries (in addition to providing an adjunct to hemostasis) after partial nephrectomy in a porcine chronic survival model. MATERIALS AND METHODS Laparoscopic upper-pole partial nephrectomies were performed in 10 farm pigs (>40 kg). After hilar clamping, an energyless incision was made at a point halfway between the hilum and the upper pole of the kidney and the collecting system was opened widely. TachoSil was applied to cover the defect; 15 to 20 minutes after the application of TachoSil, the hilar clamp was removed, hemostasis confirmed, and the pig survived. Assessment was made for hematoma and urinoma. Four weeks postoperatively, the pigs were euthanized. Ex-vivo retrograde studies were performed to assess collecting system leak. Weight, blood pressure, estimated blood loss, the weight of the partial and completion nephrectomy specimen, presence/absence of urinary leak on retrograde study, histopathologic findings, and complications were recorded. RESULTS All pigs survived. Mean warm ischemia time was 18 minutes, mean blood loss was 90 mL, and mean resected weight was 13.7 g. There was no evidence of leak on retrograde study. Histologically, nonspecific changes were noted in all specimens, which included dystrophic calcification, scarring, and areas of fibrosis at the partial nephrectomy surgical margin. CONCLUSION TachoSil seals the collecting system after partial nephrectomy on a porcine chronic survival model, in addition to providing an adjunct to hemostasis. More studies, including human trials, are warranted to evaluate this observation further.

Retroperitoneoscopic live donor nephrectomy : review of the first 50 cases at Tygerberg Hospital, Cape Town, South Africa

BACKGROUND Changing from an open to a laparoscopic live renal donor programme poses challenges and may affect donor and graft outcomes. OBJECTIVES To evaluate donor safety and graft outcomes for the first 50 retroperitoneoscopic live donor nephrectomies performed at Tygerberg Hospital, Cape Town, South Africa. METHODS The procedures were performed by a single surgeon from 8 April 2008 to 3 April 2012. Operative and anatomical data were prospectively collected. A flank approach with lateral and posterior placements was used. Vascular control was achieved with Hem-o-lok clips in the majority of cases. RESULTS The mean age of the donors was 31.5 years (range 18 - 50), 28 (56.0%) were male, and the left kidney was harvested in 28 (56.0%) of cases. The mean operating time was 149.8 minutes (range 75 - 250), mean warm ischaemic time (WIT) 181.3 seconds (107 - 630), mean blood loss 139.7 ml (5 - 700) and mean hospital stay 3.2 days (2 - 5). Mean WIT was significantly longer for right-sided than left-sided nephrectomy (213 v. 162 seconds). In two right-sided cases the renal vein was too short and vena profunda femoris was used to create length. No donor received a blood transfusion. Comparing the last 25 with the first 25 cases showed a significant decrease in mean WIT (158 v. 204 seconds) and operating time (128 v. 172 minutes). No major complications occurred. CONCLUSION Our initial 50 retroperitoneoscopic live donor nephrectomies were performed without major complications. Donor safety was maintained during the early learning curve of the transition to minimal-access donor nephrectomy.

Decision support for grape harvesting at a South African winery

Recent technological advances have had a major impact on the management of traditional wineries, giving rise to the prospect of computerised decision support with respect to a range of complex harvesting and wine making decisions which have to be taken routinely. In this paper, two nested scheduling problems are considered. The first, referred to as the active cellar scheduling problem, is concerned with making good scheduling decisions within a winery (i.e. optimal assignments of grape intake batches to different processor sets inside the active part of the cellar). The harvest scheduling problem, on the other hand, refers to the larger, over-arching problem of selecting the best possible dates on which to harvest the respective vineyard blocks in order to preserve grape quality. A nested tabu search approach is presented to solve these two scheduling problems simultaneously. This solution approach has been implemented as a computerised decision support tool, called VinDSS, and the practical workability of this tool is demonstrated by means of a special case study at a winery in the South African Western Cape.

Should baseline PSA testing be performed in men aged 40 to detect those aged 50 or less who are at risk of aggressive prostate cancer

OBJECTIVE We aimed to evaluate the presenting features and treatment outcome of prostate cancer in men aged <50 years, in a region where prostate specific antigen (PSA) screening is not readily available and most men present with symptoms. METHODS We analysed the data of 1 571 men with prostatic adenocarcinoma treated between January 1997 and December 2008 at out institution, a tertiary level public secotr hospital serving a largely indigent population. Statistical analysis was performed using Students, the Mann-Whitney and Fishers exact tests where appropriate (p<0.05 accepted as statistically significant). RESULTS Of 1 571 men, 47 (3%) were aged < 50 years. The group aged <50 years compared with that aged >50 years, had a siginificantly greater proportion with poorly differentiated adenocarcinoma (53%), locally advanced (stage T3-4) tumours (56%), haematogenous metastases (75%), significantly higher serum PSA at diagnosis (mean 621, median 74 ng/ml) and shorter survival. CONCLUSION Men aged <50 years presenting with symptoms owing to prostate cancer had significantly higher risk disease, higher mean PSA, and poorer prognosis than men aged >50 years. To diagnose prostate cancer at a potentially curable stage in men aged <50 years, it is necessary to initiate asleine PSA testing at age 40 and 45 years, and to select high-risk men for PSA surveillance in order to diagnose potentially curable cancer in those with a life expectancy >20-25 years.

A Comparison of Multi-Criteria Evaluation Methods for RSFQ Circuit Optimization

Research has been done on the metaheuristic optimization of RSFQ circuits, but these are typically limited to single criteria (e.g., yield). The importance of using multiple criteria and the relevance of each of the criteria is discussed. The application of data envelopment analysis (DEA) and an interactive normalization technique as multi-criteria evaluation methods for the optimization of RSFQ circuits are investigated. We find that these evaluation methods each have clear advantages and disadvantages over each other. The normalization technique requires the analysis designer to have a good understanding of circuit design to be accurate, while the DEA method may yield many results that are ranked equally efficient.

INTERNATIONAL MARKETING DEVELOPMENTS AND THE EFFECT ON SOUTH AFRICAN AGRICULTURE / NEIGINGE IN INTERNASIONALE BEMARKING EN DIE EFFEK DAARVAN OP DIE SUID-AFRIKAANSE LANDBOU

The global agricultural marketing environment is changing rapidly. Coupled with the advance in technology, a borderless society is emerging tha t necessitates a rethinking of traditional agricultural policies. This paper analyses this trend by presenting an overview of issues currently affecting agricultural trade, both globally and in South Africa. The latter has undergone a significant deregulation and liberalisation process of its own. Coupled with global trends towards even further deregulation, especially during the 1999 round of multilateral trade negotiations, agricultural industries and economists will be required to focus their attention in this direction. While the former need to devise strategies that will enhance their international competitiveness within a deregulated environment, the latter will have to become involved in the policy debate surrounding this issue. This necessitates, however, on both sides, an improvement of theoretical knowledge of international trade, as well as an understan...

An algorithmic version of the theorem by Latimer and MacDuffee for 2×2 integral matrices

Abstract Given two n × n integral matrices A and B , they are said to be equivalent if B = S −1 AS , where S is an n × n integral matrix with determinant ±1. If we consider n × n integral matrices with a fixed characteristic polynomial that is irreducible over Q , it is well known from a result by Latimer and MacDuffee that the number of matrix classes (equivalence classes of matrices) is equal to the number of ideal classes ( I ≅ J if I = qJ for some q in the quotient field) of the ring obtained by adjoining a root of the characteristic polynomial to Z . In this paper, we develop an effective version of this result for 2×2 matrices. We present an algorithm which given a 2×2 matrix finds a canonical representative in its class. In particular this allows us to determine whether two matrices are equivalent.

Clinical (non-histological) diagnosis of advanced prostate cancer: evaluation of treatment outcome after androgen deprivation therapy

Introduction. Transrectal biopsy in suspected adenocarcinoma of the prostate (ACP) may cause significant morbidity and even mortality. A strong association between serum prostate-specific antigen (PSA) and tumour burden exists. If biopsy can be avoided in advanced disease, much morbidity and cost may be saved.Objective. To evaluate the reliability of using PSA and clinical features to establish a non-histological diagnosis of ACP.Methods. Androgen deprivation therapy (ADT) was used in 825 (56.2%) of 1 467 men with ACP. The diagnosis of ACP was made histologically in 607 patients (73.6%) and clinically alone in 218 (26.4%), based on a serum PSA level of >60 ng/ml, and/or clinical evidence of a T3 - T4 tumour on digital rectal examination, and/or imaging evidence of metastases. We compared two randomly selected groups treated with bilateral orchidectomy (BO) based on a clinical-only (n=90) v. histological (n=96) diagnosis of ACP.Results. There was no significant difference between the groups with regard to mean follow-up (26.1 v. 26.8 months), documented PSA relapse (70% v. 67.7%), and patients alive at last follow-up (91.1% v. 95.8%). ZAR1 068 200 (US

Functions and polynomials over finite commutative rings

1 = ZAR8) was saved by treating men with advanced ACP on the basis of a clinical (non-histological) diagnosis only, and a total of ZAR24 321 000 was saved by using BO instead of luteinising hormone-releasing hormone agonists as ADT.Conclusion. A reliable clinical (non-histological) diagnosis of advanced ACP can be made based on serum PSA and clinical features. This avoids the discomfort and potentially serious complications of biopsy and saves cost.