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Biomedical subjects

G Joubert

Publications and source records attributed to G Joubert.

100 records · Page 6Linked to original sources
PubMed1984

Studies on Haemonchus contortus. X. The effect of Trichostrongylus axei in Merinos on artificial pastures.

A recently established Eragrostis curvula pasture 1,1 ha in size at Hennops River in the Transvaal Highveld was contaminated from 6 October 1976 until 20 May 1977 by 30 weaned Merinos, each infested with 7 000 infective larvae of H. contortus. On 2 November 1976 3 groups of weaned Merinos and again on 10 January 1977 a further group of Merinos were infested with 40 000 infective larvae of Trichostrongylus axei. From 19 November a single group of sheep, predosed with T. axei, and a control group grazed with the seeders for 8 weeks. After 6 weeks another group of sheep dosed with T. axei grazed with them, thus ensuring a 2-week overlap. This continued until autumn, when the last groups were removed. Efficacy against challenge reached Class C (greater than 50% effective against total worm burdens of H. contortus in greater than 50% of sheep) in early summer and autumn, but only reached significant levels of either P less than 0,01 or P less than 0,05 in summer. Peak worm burdens in controls were recorded in early autumn.

Animals↗
PubMed1984

Studies on Haemonchus contortus. XI. The effect of a bovine strain of Trichostrongylus axei in Merinos on natural pastures heavily infested with H. contortus.

Sheep grazed on natural pastures heavily infested with infective larvae of Haemonchus contortus. Sixty-eight weaned Merinos were divided into 6 groups on Day 0 (23 November 1977), and on Day +14 (7 December) 79 Merinos were divided into 7 groups. There were 2 groups of undosed controls and other groups were either dosed with infective larvae of Trichostrongylus axei (bovine strain) only on Days 0 and +14, or in combination with H. contortus, or with subsequent doses of H. contortus, 28 days later. One group (Group 12) was dosed with T. axei and treated with a subcutaneous injection of di-iodonitrophenol (DNP) on Day +14. With the exception of 2 sheep, the sheep of the first 6 groups survived until slaughter in March and April 1978, while many sheep (43) of the latter 7 groups died or were killed in extremis from March-May. T. axei dosed on 23 November (Day 0) protected Group 2 by greater than 50% in greater than 50% of sheep. In the latter 7 groups the best results were achieved when DNP was combined with predosing with T. axei. The poor results were probably due either to delayed predosing with T. axei or a massive challenge in the wettest summer on record.

Animals↗
PubMed1982

Studies on Haemonchus contortus. VIII. Attempts to protect suckling lambs against infestation with H. contortus.

A group of 12 Merino lambs, 3,5 months of age, which were still suckling, were each dosed with 40 000 infective larvae of Trichostrongylus axei on Day 0. From Day +62-Day 64 each of these lambs and those of a 2nd group of 11 controls were dosed with 30 000 infective larvae of Haemonchus contortus, and all the lambs of both groups were killed on Day +90. Attempts to use T. axei to protect them against subsequent challenge with H. contortus were unsuccessful.

Animals↗
PubMed1982

The effect of predosing calves with Trichostrongylus axei on subsequent challenge with Haemonchus placei.

Twelve calves were dosed with 40 000 and a further 12 with 80 000 infective larvae of Trichostrongylus axei respectively. These 2 groups and a control group were subsequently dosed with 50 000 infective larvae of Haemonchus placei. Predosing with T. axei had no effect on the establishment of H. placei. It is postulated that the numbers of T. axei worms present were below the 'threshold' value necessary to protect the calves against challenge with H. placei.

Animals↗
PubMedDate not supplied

Factors associated with high density lipoprotein cholesterol in a population with high high density lipoprotein cholesterol levels.

A cross-sectional study of a random sample of 976 coloureds (mixed race) of the Cape Peninsula, ages 15 to 64 years old, revealed a population with unexpectedly high levels of high density lipoprotein (HDL) cholesterol. The mean level for men was 55.4 +/- 16.1 mg/dl (SD) and for women, 60.8 +/- 16.0 mg/dl. The ratio of HDL cholesterol to total cholesterol expressed as a percentage was 26.3% +/- 9.5% for men and 28.1% +/- 9.3% for women. The HDL cholesterol levels were apparently lower than those of black and Negro populations, yet higher than those of Caucasian populations. Men with levels of HDL cholesterol above the median reported a personal history and a family history of coronary heart disease less frequently than did men with lower levels, while women with high levels of HDL cholesterol were less likely to have a history of hypertension or diabetes. Stepwise multiple regression analysis of variables significantly associated with HDL cholesterol levels showed that they explained 29.7% and 24.7%, respectively, of the variation in HDL cholesterol in men and women. Those variables independently associated with HDL cholesterol in both men and women were: serum triglyceride (-), cigarette consumption (-), alcohol, body mass index (-), age, and serum low density lipoprotein cholesterol levels (-). The reasons for the relatively high HDL cholesterol levels in this population are unknown. However, it would seem possible that these levels offer some protection against the high risk factors of smoking, hypertension, and hypercholesterolemia.

Adolescent↗
PubMedDate not supplied

Evaluation of exercise-induced stunning using myocardial perfusion imaging.

A late reduction (i.e. 1 hour post exercise) in left ventricular ejection fraction (LVEF) in patients with ischaemic heart disease was recently reported with radionuclide myocardial perfusion imaging (MPI). This was ascribed to possible stunning provoked by exercise-induced ischaemia. The purpose of this retrospective study was to evaluate the possible relationship between exercise-induced ischaemia and late (1 hour) post-exercise myocardial stunning. Forty-eight patients who underwent standard treadmill exercise with 99m Tc-MIBI MPI were analysed according to their rest and stress perfusion images. A normal group of 15 subjects, 23 patients with previous infarction and 10 with objective evidence of ischaemia were identified. Absolute change, i.e. exercise LVEF minus rest LVEF, and relative change, i.e. absolute change divided by resting LVEF (expressed as a percentage) were determined. The mean absolute change in LVEF was not significant within the normal and infarction groups but was statistically significant within the ischaemic group. The mean relative ( %) change within the normal and infarction groups was not significant, but was significant within the ischaemic group. The difference in mean absolute changes between the normal and infarction group was not significant but both these groups were statistically different when compared with the ischaemic group. No statistically significant difference in mean relative changes was found between the normal and infarction groups. The mean relative change in the ischaemic group tended to be larger than in the infarction group. The presence of a late regional wall motion abnormality or decreased LVEF after exercise (i.e. stunning) may be an important additional indicator of underlying myocardial ischaemia.

Adult↗
PubMedDate not supplied

The prevalence of risk factors for coronary artery disease in patients who had had CABG.

The conclusion of Ranjith and his co-workers from their study 'Demographic data and the outcome of acute coronary syndrome in the South African Asian Indian population' drew our attention. Young South African Indians frequently have premature atherosclerosis with diffuse and aggressive disease. This should be taken into account for risk intervention. We would like to add to this.

Aged↗