Biomedical subjects

M G Veller

Publications and source records attributed to M G Veller.

15 recordsLinked to original sources

PubMed2006

General surgery in crisis--the critical shortage.

INTRODUCTION: General surgery is facing a serious crisis. There has been a significant decline in the number of applicants for registrar posts and an inability to attract and retain general surgical specialists in the state sector. The Association of Surgeons of South Africa (ASSA) undertook this study to determine the extent and cause of the problem. METHODS: The study involved a combination of desk research and structured interviews. In addition, the Health Professions Council of South Africa (HPCSA) database was reviewed and compared with the South African Medical Association (SAMA) and ASSA databases. The medical schools provided information about student numbers and demographics, and the National Department of Health pro vided information about the status of medical practitioner and specialist posts in the state sector. RESULTS: Overall, 26.1% of the specialist posts were vacant. The situation was particularly critical in Mpumalanga and the Eastern Cape, where 84% and 58% of the specialist posts were vacant. Using a predictive model, a conservative estimate of the need for general surgeons was found to be at least 50 per year. Currently the eight medical schools graduate about 25 general surgeons per year. The changing demographics of medical students may be partly responsible for the decline in registrar applicants. CONCLUSION: The findings from this study have revealed that the shortage of general surgeons in the state sector has reached critical levels.

Career Choice↗

PubMed2006

General surgery in crisis--comparatively low levels of remuneration.

INTRODUCTION: Several factors, including comparatively low remuneration, may be responsible for the decline in applicants to general surgery. In this study, the levels of remuneration of general surgeons in the state sector were compared with other professionals in the state sector and general surgeons overseas. METHODS: The study involved a combination of desk research and structured interviews. The Paterson system of job evaluation was used to compare general surgeons with other professionals. The levels of remuneration of general surgeons in the state sector were compared with those of other professionals. RESULTS: There was a significant difference in the levels of remuneration between state-employed medical practitioners and other professional positions such as legal professionals, municipal managers and airline pilots. At senior levels (senior specialist) the remuneration was only +/- 55% of that paid to the selected comparator group. There was also a significant differential between the remuneration of state-employed general surgeons and their overseas counterparts. CONCLUSION: Levels of remuneration of state-employed medical practitioners continue to lag behind other professionals.

Career Choice↗

PubMed2006

General surgery in crisis--factors that impact on a career in general surgery.

INTRODUCTION: The Association of Surgeons of South Africa (ASSA), because of a concern about the decline in the number of applicants for registrar posts, undertook this study into the various factors that may influence the choice of surgery as career option. METHODS: The study involved a combination of desk research and structured interviews with heads of departments, specialists, and registrars in general surgery. RESULTS: The reasons for choosing general surgery as a career included the immediately visible results of a surgeon's efforts and the practical and intellectual challenge of the specialty. General surgery continued to enjoy a high status in society. The greater focus on primary health care has affected facilities at tertiary and secondary institutions. General surgeons worked excessively long hours, which was associated with increased levels of stress and placed severe strains on family life. All respondents felt that their levels of remuneration were 'poor' in relation to other disciplines and professions. CONCLUSION: In this study we identified various factors that impacted either positively or negatively on the choice of general surgery as a career option.

Career Choice↗

PubMed1999

Efficacy of vitamin E compared with either simvastatin or atorvastatin in preventing the progression of atherosclerosis in homozygous familial hypercholesterolemia.

Over a 4-year period, antioxidant therapy (vitamin E) was compared with high-dose statin therapy in 15 patients with homozygous familial hypercholesterolemia. Carotid intima-media thickness, used as an in vivo assessment of atherosclerosis, progressed rapidly during the period of vitamin E therapy but regressed on statin therapy.

Adolescent↗

PubMed1999

Low-density lipoprotein cholesterol bulk is the pivotal determinant of atherosclerosis in familial hypercholesterolemia.

This study's aim was to determine whether biochemical risk factors such as lipoprotein(a), fibrinogen, homocysteine, and insulin, as well as low-density lipoprotein (LDL) particle size, were predictive of carotid intimamedia thickness (IMT), an early marker of atherosclerosis, in subjects with familial hypercholesterolemia (FH). We also determined whether plasma 8-isoprostane, as a marker of in vivo lipid oxidation, correlated with carotid IMT. Twenty-two homozygous and 20 heterozygous subjects with FH were compared with 20 normocholesterolemic controls. On univariate analysis, plasma total and LDL cholesterol, the cholesterol-years score (CYS), lipoprotein(a), and fibrinogen, but not homocysteine or insulin, were positively related, and high-density lipoprotein (HDL) cholesterol was negatively related to carotid IMT. However, on multivariate analysis, only LDL cholesterol and the CYS predicted carotid IMT (multiple r = 0.82; r2 = 0.68; p <0.0001). The subjects with FH had large rather than small dense LDL particles, and plasma 8-isoprostane levels were not increased. LDL cholesterol and the CYS, or "cholesterol bulk" are the pivotal determinants of atherosclerosis and are the strongest predictors of carotid IMT in FH.

Adult↗

PubMed1999

Popliteal artery entrapment syndrome: more common than previously recognized.

PURPOSE: This report summarizes our experience with the popliteal entrapment syndrome in 88 limbs (48 patients) treated during a 10-year period. METHOD: The study cohort consisted of a retrospective analysis of those patients who were seen with symptoms of claudication or severe ischemia by a single surgical group and in whom unequivocal evidence of popliteal entrapment was shown either with angiography or at the time of operation. The cases were collected prospectively in a private vascular surgical practice. RESULTS: Bilateral popliteal entrapment was found in 40 of the 48 patients. The mean age at the time of presentation was 35.0 years (SD, 11.6 years). Claudication was the most frequent presenting symptom (70 of 88 limbs). Types I, II, III, and IV popliteal entrapment were found in 58 limbs (15 arteries occluded), and 30 limbs (three occlusions) were seen with a "functional" popliteal artery entrapment (apparent absence of a developmental anatomic abnormality). Of the 18 limbs with severe ischemia and associated occlusion of the popliteal artery, 15 underwent bypass grafting with reversed saphenous vein grafts, all of which remained patent during the follow-up period (median follow-up, 4.2 years; range, 1 to 10 years). One popliteal artery occlusion that was treated with thrombectomy and vein patching occluded within 6 months and necessitated subsequent vein grafting. Two limbs with inoperable occluded popliteal arteries were not subjected to reconstruction (one necessitated amputation because of advanced ischemia, and the second had extensive thrombosis of the distal run-off). In two patients (four limbs), moderate presenting symptoms abated without surgery after the discontinuation of an extreme exercise program. The remaining limbs underwent surgical decompression (all popliteal arteries remained patent, with a median follow-up of 3.9 years). CONCLUSION: The popliteal entrapment syndrome is more prevalent than has formerly been appreciated. On the basis of observations made in this series and in the surgical literature, we advise surgical correction in all cases of types I, II, III, and IV entrapment at the time of diagnosis to avoid occlusion as a result of continued arterial wall degeneration. In contrast, decompression is only advised in those patients with "functional entrapment" if they have discrete and typical symptoms because up to 50% of the normal population may display transient popliteal artery compression with extremes of plantar flexion or dorsiflexion. On the basis of the severe histologic changes found in those popliteal arteries that had undergone occlusion at the time of presentation, it is advised that the popliteal artery should be completely replaced, ideally with a vein graft, when significant degeneration or occlusion of the popliteal artery is noted at the time of operation.

Adolescent↗

PubMed1998

Retrograde balloon angioplasty of brachiocephalic or common carotid artery stenoses at the time of carotid endarterectomy.

OBJECTIVES: This study was performed to demonstrate the value and durability of intraoperative retrograde angioplasty for stenotic lesions of the aortic arch branches at the time of carotid endarterectomy for the treatment of tandem proximal and bifurcation carotid lesions. DESIGN: Retrospective analysis of the clinical data. METHODS: Forty-four patients were included in this study when they presented with symptomatic extracranial vascular disease due to stenosis of both a proximal aortic arch branch and carotid bifurcation disease. Tandem disease was detected in the vascular laboratory and confirmed by angiography. Each patient was subjected to conventional carotid endarterectomy, and at the time of operation, the proximal lesion was subjected to transluminal angioplasty through the endarterectomy arteriotomy (brachiocephalic 24; left common carotid 15; right common carotid artery five). Patients were then followed up clinically and by non-invasive tests at 6-monthly intervals. RESULTS: Forty-three successful dilatations were achieved. The single initial technical failure was due to heavy calcification of a brachiocephalic artery. In the follow-up period restenosis was noted in four patients. All restenosis occurred within 24 months. No restenosis at the angioplasty site was noted on subsequent follow-up of the remaining 39 patients. No perioperative stroke or death was encountered. A surprisingly high mortality rate was noted on follow-up in this group of patients, suggesting the presence of more aggressive and advanced diffuse vascular disease. CONCLUSION: Retrograde intraoperative angioplasty of the proximal component of a tandem extracranial lesion has in this series proven to be a safe and durable therapeutic option. This technique has an acceptable restenosis rate in a subset of patients who have been demonstrated to have a shortened life expectancy and a high mortality rate in the follow-up period.

Angiography↗

PubMed1998

A method for creating reversible ureteric obstruction in the primate.

A technique has been developed for the establishment of a state of reversible, ureteric obstruction in the primate. Ten adult males had baseline 99mTc-DTPA renogram studies. A randomly selected ureter was totally occluded and obstruction confirmed on renogram. The occlusion was reversed and subsequent renograms confirmed recovery of activity in the obstructed kidneys of the eight animals who survived the reversal procedure. Seven were alive on conclusion of the study. Prevention of ureteric strictures was achieved with an intra-ureteric silastic tube. Autopsies demonstrated patency of every previously occluded ureter. This is the first study to be reported in primates, and the second overall, in which complete ureteric obstruction and its successful reversal has been confirmed on renogram using this surgical method. The technique is suitable for the study of the effect of reversible ureteric obstruction on renal function.

Animals↗

PubMed1996

The glomerular filtration rate, effective renal plasma flow, and renal blood flow in the adult male chacma baboon (Papio ursinus).

The radionuclide determination of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) has been validated in man, but not in the primate. GFR, ERPF, and renal blood flow (RBF) were measured in a group of 12 adult male chacma baboons using radiopharmaceuticals. GFR was determined using 99mtechnetium-labelled diethylenetriamine-pentacetic acid. ERPF was measured with 131iodine-labelled hippuran. RBF, body surface area, and kidney weights were calculated using standard formulae. GFR was 49 +/- 11 ml/min and ERPF was 237.9 +/- 54.2 ml/min. Calculated RBF was 430.7 +/- 111.9 ml/min and 507.4 +/- 138.4 ml/min/100 g of renal tissue. The results are in agreement with those obtained using more laborious nonradioisotopic techniques such as para-aminohippurate (PAH) and creatinine clearance and could serve as baseline normal values in the adult male chacma baboon.

Animals↗

PubMed1995

An unusual cause of back pain in a patient with an abdominal aortic aneurysm. A case report.

A case of a 50-year-old man with chronic back pain, an abdominal aortic aneurysm and bony erosion of the lumbar spine due to a chondrosarcoma is reported. This report shows that the lumbar erosion seen in association with an aneurysm is unlikely to be a result of pressure erosion of the spine by the aneurysm, and that an extensive metastatic and septic work-up is required in such patients.

Aged↗

PubMed1994

Renal allograft preservation: a comparison of University of Wisconsin solution and of hypothermic continuous pulsatile perfusion.

A study was performed to compare early allograft function in kidneys preserved with University of Wisconsin (UW) solution to kidneys preserved by hypothermic pulsatile perfusion. The study consisted of two sets of data. The first set was a donor-paired study (matched data) of 30 heart-beating, hemodynamically stable donors. After removal from the donor each cooled kidney was individually prepared for preservation. One kidney was flushed with +/- 500 ml of UW solution and stored in UW solution on slushed ice. The other kidney was continuously perfused with cooled (4-6 degrees C) cryoprecipitated plasma. The kidneys were transplanted into suitable recipients in a random sequence. Twelve donors were excluded from the study because one or both kidneys were transplanted into recipients who had previously been transplanted. The remaining 36 kidneys were implanted into two similar groups after a mean of 19 hours in the pulsatile perfusion group and 18 hours in the UW solution group. The second set of data consisted of all the kidneys preserved in UW solution (n = 62) at our institution and of 57 kidneys preserved by hypothermic continuous pulsatile perfusion during the same period (mixed data) and was used to evaluate the effect of prolonged preservation (longer than 24 hours) on delayed graft function. Both of these groups were also comparable. Acute tubular necrosis (ATN) was defined as the need for dialysis during the 1st week after transplantation, and delayed function as the delayed clearance of creatinine during the early post-operative phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1993

Measurement of the ultrasonic intima-media complex thickness in normal subjects.

PURPOSE: The evolution of atherosclerosis can be studied before development of symptomatic plaque by evaluating morphologic changes of the intima-media (I-M) complex, seen on high-resolution ultrasonography of the arterial wall. These qualitative changes require large alterations in vessel wall appearance to recognize progression of atherosclerosis. It has been suggested that measurement of the thickness of the I-M complex may be a quantitative and more sensitive method of assessing these early atherosclerotic changes. METHODS: High-resolution ultrasonography has been used to measure the thickness of the I-M complex in 140 symptom-free subjects. RESULTS: The mean thickness of the I-M complex of the common carotid arteries was linearly related to the age (r = 0.77; p < 0.001), pack-years of smoking (r = 0.39; p < 0.05), the systolic blood pressure (r = 0.51, p < 0.01), and to the arterial ultrasound score (r = 0.85). The arterial ultrasound score has previously been shown to correlate with the presence of asymptomatic myocardial ischemia and with the development of cardiovascular symptoms. The mean thickness of the I-M complex in subjects without plaque (in the common carotid or common femoral artery bifurcations) was significantly thinner than in subjects with plaque (p < 0.001). CONCLUSION: The thickness of the I-M complex of the common carotid arteries is a measure of the risk for the development of cardiovascular symptoms in symptom-free individuals.

Adolescent↗

PubMed1993

Successes and failures of endoscopic injection haemostasis for bleeding peptic ulcers. A prospective clinical study.

Fifty-two consecutive patients with upper gastrointestinal haemorrhage, shock (systolic blood pressure less than 100 mmHg) and a peptic ulcer showing endoscopic stigma of recent haemorrhage underwent attempts at endoscopic haemostasis. The ulcers were injected with a dilute solution of adrenaline followed by 5% ethanolamine oleate. Active bleeding was present in 22 patients (42%) at initial endoscopy. Bleeding was controlled in 40 patients (77%) in hospital. Failure occurred more frequently in duodenal ulcers than gastric ulcers (46% v. 7%; P < 0.004), and in giant (more than 2 cm diameter) duodenal ulcers (6/7) than smaller duodenal ulcers (3/15). We recommend early surgery for large posterior duodenal ulcers in preference to endoscopic injection methods.

Adult↗

PubMed1987

Renal retransplantation. The Johannesburg Hospital experience.

Between 1968 and 1985 108 renal retransplants were performed at Johannesburg Hospital; 102 patients received a second, 5 patients a third, and 1 patient a fourth kidney. The actuarial graft survival at 1 and 5 years is 52.8% and 40.5%. All retransplanted kidneys were obtained from cadaver donors. Factors that influence second graft survival are the period of survival of the previous graft, the use of cyclosporin A, the level of pre-sensitisation determined by preformed antibodies, the original disease (in particular diabetes and analgesic nephropathy) and the patient's sex. The results of retransplantation are not significantly different from those found in patients with first allografts; hence retransplantation is justified in those individuals whose previous donor kidney has ceased to function.

Adolescent↗

PubMedDate not supplied

Arterial wall changes in type 2 diabetic subjects.

Arterial ultrasonic appearances using high resolution ultrasound were studied in 97 subjects with Type 2 diabetes and age- and sex-matched controls. The intima-media thickness of both common carotid arteries was measured 2 cm proximal to the bifurcation and the presence or absence of plaque on both common and femoral bifurcations was recorded. The mean intima-media thickness in subjects with diabetes was 0.82 +/- 0.22 mm while in the controls 0.66 +/- 0.13 mm (p < 0.001). Multiple regression in diabetic subjects only showed no correlation between age, sex, body mass index, smoking, duration of diabetes, systolic or diastolic blood pressure, cholesterol, HDL, LDL, triglycerides, HbA1 and the common carotid artery intima-media thickness. Type 2 diabetes is associated with increased intima-media thickness which has been found to be a marker of cardiovascular events in the general population.

Arteriosclerosis↗