SUNScholar - Browsing by Author "Taljaard, J. J. F."

Browsing by Author "Taljaard, J. J. F."

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Acetylated fetal haemoglobin in neonates born to mothers with established and gestational diabetes
(Health and Medical Publishing Group (HMPG), 1985-10) MacFarlane, C. M.; Tsakalakos, N.; Taljaard, J. J. F.
Birth weight ratios (BWRs) and cord blood C-peptide values were significantly higher in neonates born to mothers with well-controlled gestational diabetes (GD) than in those born to mothers with well-controlled established diabetes (ED) or mothers with normal results on glucose tolerance testing. The neonates born to the ED mothers had the highest cord blood acetylated fetal haemoglobin (Hb F1) values, and these values correlated with cord C-peptide values. The cord C-peptide values in the GD group correlated with BWRs, but not with Hb F1 values. These results suggest differential tissue utilization of glucose in neonates born to mothers with different types of diabetes.
Aetiology of pulmonary dysfunction in total hip replacement operations: The influence of nifedipine on the factors involved
(Health & Medical Publishing Group, 1987-05) Du Toit, H. J.; Macfarlane, C. M.; Taljaard, J. J. F.; King, J. B.; Cooper, R. C.
ENGLISH ABSTRACT: Patients undergoing total hip replacement surgery who developed pulmonary dysfunction (PD) demonstrated evidence of a complement activation and increased thromboxane A2 (TXA2) synthesis. In a double-blind study nifedipine (Adalat; Bayer-Miles) was shown to inhibit complement activation and TXA2 synthesis and thus appears to offer protection against PD.
Early recognition of pulmonary dysfunction during intramedullary orthopaedic surgery
(Health & Medical Publishing Group, 1982) Du Toit, H. J.; Erasmus, F. R.; Taljaard, J. J. F.
Peri-operative partial arterial oxygen tension (Pa(O2)) was monitored in 20 patients undergoing total hip replacement. Three distinct groups emerged on analysis of the arterial oxygen tensions. In group I there was no initial decrease in Pa(O2) but it rose above baseline level towards the end of the procedure. In group II there was a distinct fall in Pa(O2) during the acetabular and femoral stages of the operation. On termination of the procedure Pa(O2) had returned to baseline levels. In group III Pa(O2) values were significantly lower than those in group II during the acetabular and femoral stages and decreased further at the end of the procedure. One patient in group II and 6 in group III developed postoperative pulmonary dysfunction. A progressive deterioration in Pa(O2) during hip replacement without recovery at end of the procedure indicates that the patient is likely to develop postoperative pulmonary dysfunction.
The effect of acute haemodilution during cardiopulmonary bypass on blood calcium, pH, phosphorus and protein values
(Health & Medical Publishing Group, 1983) Coetzee, A. R.; Van der Merwe, W. L.; Taljaard, J. J. F.; Els, D.
The changes in total serum calcium, ionized calcium, total serum proteins, albumin and phosphate levels during cardiopulmonary bypass were measured. The possible causes of the changes in these parameters are discussed. The effect of the presence of heparin on serum ionized calcium is evaluated. The metabolic and clinical significance of the changes in blood components measured are discussed, special attention being paid to the use of calcium as an inotropic agent at the termination of cardiopulmonary bypass.
Endemic fluorosis -a model for studies examining the effect of fluoride on bone
(Health & Medical Publishing Group, 1997) Honiball, S. C.; Blaauw, Renee; Martell, R.; Taljaard, J. J. F.; Stokol, J. M.; Hough, F. S.
The use of fluoride in the treatment of osteoporosis is complicated by concerns about the integrity of the newly formed bone, as well as the fact that not all patients respond to the drug. In an attempt to broaden insight into the varied skeletal response to fluoride exposure, we studied (clinical, dietary analysis, radiology, biochemistry and genetic markers) all 114 permanent inhabitants of an endemic fluorosis area. Unequivocal radiological evidence of osteofluorosis was present in 26% of subjects, while 48% had normal skeletal radiological results and 4% were found to be osteopenic. Twenty-two per cent were unclassifiable. Individuals with fluorosis were older and predominantly male. Although musculoskeletal symptoms occurred more frequently in patients with osteofluorosis, these subjects did not have an increased fracture prevalence and were, in fact, found to have a higher metacarpal as well as femoral cortical bone mass. In subjects with osteofluorosis, the average fluoride intake and residency in the area were similar to those of unaffected Kenhardt individuals, implying that there are causative factors other than fluoride exposure. Moreover, renal excretion of fluoride was comparable, as was the average energy, protein, mineral and alcohol intake. Mean serum calcium, phosphate, alkaline phosphatase, parathyroid hormone, calcitonin and 25-hydroxyvitamin D levels were unremarkable and similar in subjects with and without osteofluorosis. However, a family tree analysis of the population revealed that 4 very closely related subjects had osteopenia, which suggests that a genetic predisposition may at least partially explain why the skeletal response to fluoride is not determined by fluoride exposure alone.
Endocrine responses after thyrotrophin-releasing hormone stimulation and dexamethasone suppression tests in the major depressive syndrome
(Health & Medical Publishing Group, 1986-10) Aalbers, C.; Taljaard, J. J. F.; Gagiano, C. A.
The effects of dexamethasone 1 mg on plasma cortisol levels and of thyrotrophin-releasing hormone (TRH) 200 μg on thyrotrophin (TSH), growth hormone and prolactine levels in 107 patients with a major depressive disorder (MDD) were compared with those in 87 healthy subjects. Individual hormonal responses and combinations of hormonal responses after administration of dexamethasone and TRH were evaluated as diagnostic aids for MDD by calculating sensitivity, specificity and efficiency for single and multiple hormonal abnormalities. In patients suffering from MDD, 65% of men, 74% of reproductive women and 71% of menopausal or hysterectomized (H/M) women had abnormal responses (sensitivity) to a dexamethasone suppression test (DST). When the DST and TSH responses to TRH were combined, 85% of men, 87% of reproductive women and 84% of H/M women had abnormal results. If the efficiency of the different combinations of hormone responses is calculated, a totally different picture emerges.
Inappropriate antidiuretic state in long-term psychiatric inpatients
(Health & Medical Publishing Group, 1990) Emsley, R. A.; Van Der Meer, H.; Aalbers, C.; Taljaard, J. J. F.; Emsley, R. A.; Van Der Meer, H.; Aalbers, C.; Taljaard, J. J. F.
To investigate the occurrence of an inappropriate antidiuretic state in a long-term psychiatric inpatient population, 690 patients underwent serum sodium determination. Forty-four patients (6.4%) had levels < 133 mmol/l. Fifteen of these patients could be investigated further and the biochemical findings in all were consistent with an inappropriate antidiuretic state. Evidence of previous episodes of water intoxication was found in 80% of these patients. Although more than one possible cause was present in most patients, the two factors most strongly incriminated in the pathogenesis of the inappropriate antidiuretic state were the drugs carbamazepine and hydrochlorothiazide.
Katesjolestrogene
(Health & Medical Publishing Group, 1980) Neethling, A. C.; Taljaard, J. J. F.
Hydroxylation of oestrogens in the 2 or 4 positions leads to the formation of catechol oestrogens. These compounds are physiologically active in animals, especially in the control of gonadotropin secretion. Physiological activity can be ascribed to either an oestrogenic action or interaction with the catecholaminergic systems. These compounds are also formed in human subjects. Surprisingly high levels are found in the urine. The peri-ovulatory peak in urinary catechol oestrogen excretion is compatible with a role for these compounds in the control of gonadotropin secretion.
LP (a) levels and apo (a) phenotypes in urban black South African men
(Health & Medical Publishing Group, 1998) Carstens, M. E.; Burgess, L. J.; Taljaard, J. J. F.
Objective. To investigate the lipoprotein (a) (Lp (a)) levels and apolipoprotein (a) (apo (a)) phenotypes in a group of urban black South African men. Design. Cross-sectional design. Setting. Lead acid battery plant, East London, Eastern Cape. Participants. Blood samples from a study on the association between lead and renal failure were kindly donated for the present study and 111 of the donors participated (K Steyn - personal communication). Outcome measures. Lp (a) levels and apo (a) phenotypes. Results. Three groups were identified: those with normal (< 300 U/l), intermediate (300-700 U/l) and high (> 700 U/l) plasma Lp (a) concentrations. Nine apo (a) phenotypes and 26 combinations thereof could be discerned. Apart from the single- and double-band phenotypes described before, triple-band phenotypes were also present. As the Lp (a) values increased, the relative frequency of the single-band phenotype decreased, whereas the relative frequency of the double-band phenotype increased. The relative frequency of the triple-band phenotype was highest in the group with high Lp (a) concentrations. No correlation was evident between the size of the apo (a) isoforms and the Lp (a) concentrations. Conclusions. Raised plasma Lp (a) levels have been associated with coronary heart disease (CHD). In addition, it has been proposed that the apo (a) gene determined plasma Lp (a) concentrations. These studies were performed using plasma from white subjects. CHD is uncommon in black South Africans. The reason may be that, given the lack of relationship between the size of the apo (a) isoforms and the Lp (a) concentrations observed in the present study, factors other than the isoform size may determine the Lp (a) levels in this particular ethnic group.
Measurement of micro-albuminuria in patients with diabetes mellitus
(Health & Medical Publishing Group, 1992) Nortje, H. F. M.; Aalbers, C.; Taljaard, J. J. F.; Hough, F. S.; Nortje, H. F. M.; Aalbers, C.; Taljaard, J. J. F.; Hough, F. S.
Persistent micro-albuminuria (MA) in patients with diabetes mellitus identifies a high-risk group for the development of vascular complications. Since the methodology involved in measuring MA has not been standardised, MA in 40 diabetic patients was measured in order to compare nephelometry with radio-immunoassay (RIA). The effect of storage (7 days), the influence of freezing and thawing on MA levels, and possible differences between glass and plastic containers were also assessed. An excellent correlation (r = 0,971) was found between RIA and nephelometry. Urine could be safely stored at 4°C in either plastic or glass containers without any signiicant influence on MA concentrations. It is concluded that nephelometry is an excellent method for accurately measuring MA.
Methylprednisolone and the adult respiratory distress syndrome
(Open access journal, 1984-06) Du Toit, H. J.; Erasmus, F. R.; MacFarlane, C. M.; Taljaard, J. J. F.; King, J. B.; De Klerk, A. J.; Elk, E.
Total hip replacement was carried out on 22 patients under general anaesthesia. Of these, 10 were pretreated with methylprednisolone (30 mg/kg); 1 of these developed the adult respiratory distress syndrome (ARDS) and had high levels of thromboxane B2 (TXB2) 5 minutes after fixation of the femoral prosthesis and at the end of the operation. The other 12 patients served as controls; 5 of them developed ARDS and had statistically significant higher TXB2 levels than the other 7 control patients who remained well. All patients who did not develop ARDS had low TXB2 levels. TXB2 and β-thromboglobulin levels followed the same trend and there was good correlation (r = 0.6806; P < 0.01) at the end of the operation in the control group patients who developed ARDS. There was no statistical difference in 6-keto-PGF(1α) levels between the patients who developed ARDS and those in the control group who remained well. Steroids reduce arachidonic acid metabolism by inhibiting the release of substrate for cyclo-oxygenase and lipoxygenase activity. Patients prone to ARDS thus benefit from methylprednisolone administration.
Neonatal pancreatic function in infants born to mothers with gestational and overt diabetes
(Health and Medical Publishing Group -- HMPG, 1984-11) De Villiers, T. J.; MacFarlane, C. M.; Tsakalakos, N.; Taljaard, J. J. F.
Neonatal pancreatic function was assessed in infants born to non-diabetic mothers and to mothers with well-controlled gestational diabetes (GD) and overt diabetes (OD) using cord blood C-peptide estimations and the calculation of cord C-peptide/glucose ratios. Exaggerated pancreatic function was present in infants born to mothers with GD. In these infants the increased cord C-peptide values and cord C-peptide/glucose ratios correlated with their increased birth weight ratios. These results could not be explained on the basis of maternal hyperglycaemia and a possible intrinsic difference in pancreatic response between infants born to mothers with GD and those born to mothers with OD is suggested.
A new model for the pathophysiology of Alzheimer's disease : aluminium toxicity is exacerbated by hydrogen peroxide and attenuated by an amyloid protein fragment and melatonin
(Health & Medical Publishing Group, 1997) Van Rensburg, S. J.; Daniels, W. M. U.; Potocnik, F. C. V.; Van Zyl, J. M.; Taljaard, J. J. F.; Emsley, R. A.
Objectives. Although Alzheimer's disease (AD) is the leading cause of dementia in developed countries, there is an as yet unexplained lower prevalence of the disease in parts of Africa. AD is characterised by a catastrophic loss of neurons; free radicals (oxidative toxins) have been implicated in the destruction of the cells through the process of lipid peroxidative damage of cell membranes, previously aluminium (Al) and a fragment of beta amyloid (Aβ 25-35) were shown to exacerbate free-radical damage, while melatonin reduced this effect. The aim of the present study was: (i) to investigate the conditions determining the toxicity of Al and Aβ 25-35; and (ii) to assess whether melatonin could attenuate the damage done by both aluminium and the amyloid fragment, thus suggesting a pathway for the aetiology of AD. Design. An in vitro model system was used in which free radicals were generated, causing lipid peroxidation of platelet membranes, thus simulating the disease process found in the brain. Results. 1. Al and Aβ 25-35 caused lipid peroxidation in the presence of the iron (II) ion (Fe2+), Al being more toxic than Aβ 25-35. 2. Aβ 25-35 attenuated the lipid peroxidation promoted by Al. 3. Hydrogen peroxide (H2O2) greatly exacerbated the toxicity of Al and Aβ 25-35. 4. Melatonin prevented lipid peroxidation by Al and Aβ 25-35 in the absence of H2O2, but only reduced the process when H2O2 was present. Conclusions. In the light of the results obtained from the present study, the following hypotheses are formulated. 1. In AD, excessive quantities of Al are taken up into the brain, where the Al exacerbates iron-induced lipid peroxidation in the lysosomes. 2. In response, the normal synthetic pathway of amyloid protein is altered to produce Aβ fragments which attenuate the toxicity of Al. In the process of sequestering the Al and iron, immature plaques are formed in the brain. 3. Microglia are activated, in an attempt to destroy the plaques by secreting reactive oxygen species such as H2O2. At this point in the disease process, lipid peroxidation causes a catastrophic loss of brain cells. 4. Melatonin, together with other free radical scavengers in the brain, reduces the free-radical damage caused by Al and Aβ, except in the latter stages of the disease process. Since melatonin is produced by the pineal gland only in the dark, the excess of electric light in developed countries may help explain why AD is more prevalent in these countries than in rural Africa.
'n Ondersoek na die meganisme van delta-aminolevuliniensuur-neurotoksisiteit
(Health & Medical Publishing Group, 1981) Taljaard, J. J. F.; Lamm, M. C. L.; Truter, L.
The neurotoxicity of δ-aminolaevulinic acid (ALA), porphobilinogen (PBG), glutamic acid, γ-aminobutyric acid and kainic acid was compared in order to investigate the possibility of a common neurotoxic mechanism. Only ALA (10 μM) and glutamic acid (1 mM) were toxic towards neurons in culture, as measured by cell survival after 5 days' exposure. 3H-kainic acid binds to striatal membranes with an equilibrium dissociation constant (KD) of 57 nM and the number of binding sites was found to be 20 pmol/g striatal tissue. However, neither of the porphyrin precursors could displace kainic acid from these binding sites. Kainic acid alone caused neuronal degeneration after intrastriatal administration, as determined by 3H-spiroperidol binding to striatal membranes. The porphyrin precursors ALA and PBG thus do not share a common neurotoxic mechanism with the well-known neurotoxin kainic acid.
A rapid screening test for pleural exudates
(Health and Medical Publishing Group (HMPG), 1999-01) Burgess, L. J.; Taljaard, J. J. F.; Maritz, F. J.
Self-induced water intoxication : a case report
(Health & Medical Publishing Group, 1988) Emsley, R. A.; Taljaard, J. J. F.
A 19-year-old female schizophrenic with self-induced water intoxication is described. Factors of pathogenic significance included primary polydipsia and non-maximal urinary diluting capacity.
Serum phosphate and anxiety in major depression
(1990) Aalbers, C.; Emsley, R. A.; Taljaard, J. J. F.
[No abstract available]
Sex-dependent differences in phenobarbitone-induced oestradiol-2-hydroxylase activity in rat liver
(Health & Medical Publishing Group, 1981) Theron, C. N.; Neethling, A. C.; Taljaard, J. J. F.
Oestradiol-2-hydroxylase (E2-OH) activity was measured in liver and brain microsomes of 6-8-week-old Wistar rats. Phenobarbitone (75 mg/kg daily for 3 days) significantly increased enzyme activity in the liver of males and females, but there were striking differences between the two sexes. In males the enzyme activity was increased by 37% over control values and in females by 200%. The total microsomal cytochrome P-450 content was increased by 75% in males and by 82% in females. The apparent Michaelis constant (Km) of E2-OH for 17β-oestradiol in untreated males (9.8 μM) and females (9.2 μM) did not differ significantly. Phenobarbitone treatment, however, tended to reduce the apparent Km in males (8.2 μM) and to increase it in females (18.7 μM). E2-OH activity was also detected in brain tissue of both sexes, but it was 50-200-fold lower than in the liver and was not increased by phenobarbitone.
Value of acetylated haemoglobin assay in fetal assessment
(Health & Medical Publishing Group, 1987-5) Macfarlane, C. M.; Tsakalakos, N.; Taljaard, J. J. F.
Acetylation of fetal haemoglobin, probably a posttranslational, intracellular, enzyme-mediated reaction, depends upon an adequate supply of glucose and oxygen to the fetus and the nature of the diabetes (if present) in the mother. These complicating factors limit the general usefulness of acetylated fetal haemoglobin assay in fetal assessment.
Zinc and platelet membrane microviscosity in Alzheimer's disease. The in vivo effect of zinc on platelet membranes and cognition
(Health & Medical Publishing Group, 1997) Potocnik, F. C. V.; Van Rensburg, S. J.; Park, C.; Taljaard, J. J. F.; Emsley, R. A.
Objectives. To investigate the effects of oral zinc supplementation on: (i) plasma zinc concentrations; (ii) platelet membrane microviscosity in vivo; and (iii) cognitive function of Alzheimer's disease (AD) patients. Design. An open-labelled pilot study. Setting. University of Stellenbosch Medical School and Stikland Hospital. Subjects. Six volunteer AD patients. Outcome measures. Plasma zinc levels, platelet membrane microviscosity and cognition (MMSE and ADAS-cog tests). Results. Oral zinc supplementation (30 mg/day) did not increase plasma zinc levels significantly, but significantly increased platelet membrane microviscosity (P = 0.02; 6 patients). Four patients, who underwent 12 months of evaluation, showed modest cognitive improvement on psychometric testing (Mini-Mental State Examination and the cognitive portion of the Alzheimer's Disease Assessment scale scores). Conclusions. While earlier literature promoted the use of zinc in AD patients, a recent study has contradicted this and implicated zinc in the aetiology of Alzheimer's disease. On the basis of the above results, it may be premature to single out zinc as a causal agent in AD.

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