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P H Joubert

Publications and source records attributed to P H Joubert.

At least 37 records · Page 2Linked to original sources
PubMed1990

Interaction in the laboratory between Helisoma duryi, a possible competitor snail, and Biomphalaria pfeifferi, snail intermediate host of Schistosoma mansoni.

The planorbid snail, Helisoma duryi, has been proposed as a possible biocontrol agent against the intermediate host snails of schistosomiasis. In an attempt to evaluate the possible effect of interference between H. duryi and Biomphalaria pfeifferi, life-tables were compiled for these two snail species maintained both in the presence of each other and separately. The calculated population parameters indicated that H. duryi had a higher innate capacity of increase, net reproduction rate and finite rate of increase as well as a longer lifespan than the target species. However, the biological potential of B. pfeifferi was not influenced by the presence of H. duryi, and the latter appears to be unable to act as competitor against B. pfeifferi under similar prevailing conditions. It is possible that the situation might change under conditions of crowding and starvation.

Animals↗
PubMed1990

The effect of miglitol and acarbose after an oral glucose load: a novel hypoglycaemic mechanism?

1. Alpha-glucosidase inhibitors such as miglitol and acarbose lower blood glucose after a starch load in healthy volunteers and diabetic patients by interfering with the conversion of disaccharide to monosaccharide in the gastrointestinal tract. 2. The effect of placebo, 100 mg miglitol and 100 mg acarbose given 30 min prior to a 75 g oral glucose load was investigated in nine healthy Caucasian volunteers. 3. Miglitol produced a statistically significant fall in post-peak blood glucose levels when compared with placebo and acarbose. Serum insulin did not change significantly. 4. As miglitol is well absorbed and acarbose is not, it is suggested that miglitol has a systemic hypoglycaemic effect, probably related to its close structural similarity to glucose, which warrants further investigation.

1-Deoxynojirimycin↗
PubMed1990

Poisoning admissions of black South Africans.

During the period 1981-1985, 1306 patients with acute poisoning were admitted to Ga-Rankuwa Hospital. Of these 60% were males and 40% females. The majority (80%) were children aged 10 years or less. Sixty patients (4.6%) died. Most poisonings were accidental and only 4.0% were due to deliberate self-poisoning. The most important causes of acute poisoning were kerosene (59%) and traditional medicines (15.8%). The major causes of mortality were traditional medicines responsible for 51.7% and kerosene responsible for 26.7% of the deaths that occurred. The prevention and treatment of kerosene poisoning and poisoning by traditional medicines merits high priority in the health care of the indigenous population of South Africa.

Adolescent↗
PubMed1989

Geographical distribution and habitat preferences of the invader freshwater snail species Lymnaea columella (Mollusca: Gastropoda) in South Africa.

The present geographical distribution of Lymnaea columella, as recorded in the National Freshwater Snail Collection, is described and discussed. It appears that L. columella is the most successful colonist of all the freshwater snail species in South Africa, and, together with Bulinus tropicus and Lymnaea natalensis, it forms the most widely distributed freshwater snail species in the region. Data regarding the 2,341 discovery sites of L. columella recorded by collectors during surveys are analysed. L. columella cluster mainly in rivers or streams with perennial, slow flowing, or stagnant freshwater with many plants and a mud substrate. L. columella is regarded as a more effective intermediate host for the transmission of fascioliasis than the indigenous snail species. The economical implications of this are discussed briefly in the light of its success as an invader species.

Animals↗
PubMed1988

Chorea and psychiatric changes in organophosphate poisoning. A report of 2 further cases.

The acute muscarinic and nicotinic side-effects of organophosphate poisoning are well known. Less commonly encountered are neurological symptoms such as chorea and psychiatric disturbances such as psychoses and depression. Two patients with organophosphate poisoning are described, both exhibiting marked choreiform dyskinesias and one experiencing severe depression and emotional lability. Both responded well to the appropriate treatment. Because of the widespread use of organophosphate insecticides in agriculture, the neurological and psychiatric effects of chronic low-dose exposure to organophosphates in farmers and their employees deserves attention.

Adolescent↗
PubMed1988

Ethnic differences in response to beta-blockade: fact or artefact? A study with bisoprolol and propranolol.

A randomized, double-blind, placebo-controlled study was performed in 8 white and 8 black volunteers matched for sex, age and mass. The effect of 3 intravenous doses of a new, cardioselective beta-adrenergic blocker, bisoprolol, on the heart rate increase after standardized exercise was compared to that of 3 doses of propranolol. As described previously for propranolol, black volunteers showed less response than whites to beta-blockade assessed in terms of the reduction in exercise-induced tachycardia. The effects of the two beta-blockers were similar and the apparent ethnic difference was seen with both drugs. It has previously been shown that black volunteers have a higher intrinsic heart rate (i.e. heart rate after parasympathetic and beta-adrenergic blockade of the heart) than whites, but their resting heart rates are similar because of greater parasympathetic tone in blacks. When exercise-load was calculated as increase in heart rate above that after atropinization, no ethnic differences were seen. It is suggested that in populations that are heterogenous in terms of the heart rate increase after atropine, work load should be standardized in terms of the increase in heart rate over the atropine heart rate rather than on absolute heart rate. The apparent ethnic difference represents a flaw in methodology as applied to a heterogenous volunteer population.

Adolescent↗
PubMed1988

Effects of essential fatty acids on mild to moderate essential hypertension.

A double-blind placebo-controlled study with a crossover design was conducted on 25 non-obese black patients with mild-moderate uncomplicated essential hypertension. They were randomly assigned into two groups. After having received placebo capsules for 4 weeks, they received dietary supplementation with either Efamol-marine (containing desaturated n-6 and n3 essential fatty acids), or sunflower seed and linseed oil capsules for 12 weeks. Thereafter a second 4 weeks placebo phase and a subsequent second 12-week active phase were entered into during which a crossover of the dietary supplementation of the groups was brought about. The mean systolic blood pressure of patients receiving Efamol-marine was significantly lowered after 8 and 12 weeks, while those receiving sunflower/linseed oil supplementation had no significant reduction of blood pressure. This observation may indicate that defective desaturation of the essential fatty acids by the enzyme delta-6-desaturase, could play an important role in the etiology of essential hypertension.

Adult↗
PubMed1988

The tegument of Schistosoma hippopotami from Hippopotamus amphibius in the Kruger National Park.

Schistosoma hippopotami were collected from the right heart chambers and pulmonary arteries of Hippopotamus amphibius culled in the Kruger National Park. The schistosomes were subjected to scanning electron microscopy as well as optical microscopy. The results indicate that S. hippopotami is not conspecific to S. mansoni as suggested in the literature. On account of the morphology of certain tegumental structures of both male and female parasites, it is suggested that S. hippopotami is adapted to the pulmonary arterial circulation of its host.

Animals↗
PubMed1988

Notes on the occurrence of tubercular spines in Schistosoma margrebowiei and Schistosoma mattheei.

Scanning electron microscopical (SEM) studies on the tegument of the bovid schistosomes, Schistosoma margrebowiei and Schistosoma mattheei have yielded conflicting results; certain authors observed the tubercles on the tegument of these species to be spined, while others reported that they are spineless. The present study indicates that the protrusion of tubercular spines is subject to phenotypic plasticity regulated by external factors such as the identity of the host species and whether or not the schistosome is paired.

Animals↗
PubMed1988

Aspects of poisoning with traditional medicines in southern Africa.

During 1981-1985, 1306 patients were admitted to Ga-Rankuwa Hospital due to acute poisoning. The major causes were paraffin (59.0%) and traditional medicines (15.8%). The mortality from paraffin was low (2.1%), but poisoning from traditional medicine resulted in a high mortality (15.2%) and accounted for 51.7% of all deaths. The traditional healer was the main source (83.4%), of traditional medicines, while 11.6% was bought from African medicine shops. The rest was acquired from other sources. In 82.5% of cases traditional medicines were taken orally, and in 10.5% of cases they were administered as an enema. Poisoning by traditional medicines was always accidental and probably due to overdosage. Vomiting, diarrhea, and abdominal pain were the most frequently encountered symptoms while the lungs, liver, and central nervous system were commonly affected. Treatment consisted of ventilation, intravenous fluids, and other palliative measures. A great deal of secrecy still surrounds traditional medicine, hampering rational therapy. Questioning of patients and interviews with traditional healers facilitated the identification of a number of major etiological agents. This elucidated the problem and should promote effective treatment.

Adolescent↗
PubMed1987

Miglitol may have a blood glucose lowering effect unrelated to inhibition of alpha-glucosidase.

Miglitol is an alpha-glucosidase inhibitor which lowers blood glucose and insulin concentrations in healthy volunteers after a starch meal. It also lowers blood glucose concentrations after a starch meal in patients with non-insulin-dependent diabetes mellitus, but under these circumstances insulin is unaffected. We have studied the effect of miglitol after a glucose load in six healthy male volunteers. Although one would expect an alpha-glucosidase inhibitor to have no effect on blood glucose concentrations after a glucose load, miglitol produced a significant decrease in blood glucose concentrations after the absorption peak. This could be due to enhancement of insulin effects or to depression of anti-insulin factors.

1-Deoxynojirimycin↗
PubMed1987

The occurrence of Schistosoma mattheei in the south-western Transvaal.

To determine whether Schistosoma mattheei is present in the south-western Transvaal, sixty habitats were searched for the intermediate host snail, Bulinus africanus. Ten populations of this snail were located, 2 of which were infected with S. mattheei. Eggs of one of these isolates, originating from a spring in the Mooi River, were examined with an optical microscope. Scanning electron micrographs of the teguments of adult male worms and the terebratorial membranes of miracidia are described. These parasites are morphologically similar to some previously described from another habitat in the same geographical area and both populations can be regarded as typical S. mattheei.

Animals↗
PubMed1986

Bilharzia risk in Lichtenburg, Tvl.

The discovery of Biomphalaria pfeifferi, the intermediate host of Schistosoma mansoni, in the RSA in the recreational area of Lichtenburg prompted an investigation to assess the bilharzia risk posed by their presence. Localized populations of B. pfeifferi were found in the recreational area and in the adjoining game breeding farm. The population of downstream areas by the snails appears to be prevented by the water quality. It is proposed that the large populations of aquatic birds in the game breeding farm be lured to the snail-infested areas as a possible means of eradication. The susceptibility of these snails to S. mansoni was experimentally confirmed.

Animals↗