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Biomedical subjects

R Brun

Publications and source records attributed to R Brun.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Selection of chloroquine-resistant Plasmodium falciparum strains in tourists under chemoprophylaxis].

In a prospective study 20 P. falciparum isolates imported from Africa by non-immune tourists were investigated for chloroquine sensitivity using the in vitro microtest and the results were compared with the plasma chloroquine concentration. All 6 patients taking correct chloroquine prophylaxis (chloroquine plasma levels between 0.1-0.5 nmol/ml) harboured highly resistant P. falciparum strains (schizont maturation at 3.2 and 6.4 nmol/ml blood in 3 patients each). In the 4 patients with inadequate prophylaxis (plasma levels between 0.02-0.1 nmol/ml) the degree of resistance was lower (at 1.6 and 6.4 nmol/ml blood in 2 patients each). Chloroquine-sensitive strains were found only in patients with chloroquine plasma levels below 0.02 nmol/ml and in 4 of 5 patients who did not show chloroquine in the plasma. Selection of chloroquine-resistant P. falciparum strains under short term chloroquine chemoprophylaxis appears to be highly probable.

Africa↗
PubMed1986

Microscopic and flow cytophotometric analysis of parasitemia in cultures of Plasmodium falciparum vitally stained with Hoechst 33342--application to studies of antimalarial agents.

Conditions for rapid vital staining of Plasmodium falciparum infected human erythrocytes were 1 microgram/ml of the dye Hoechst 33342 for 15 min in the standard culture medium at 37 degrees C. Fixed and stained cultures were analyzed by fluorescence microscopy and flow cytophotometry. The usefulness of this type of analysis for in vitro studies of antimalarial agents was demonstrated using three such agents--cyclosporin A, chloroquine, and pyrimethamine.

Antimalarials↗
PubMed1979

Nickel in food: the role of stainless-steel utensils.

Nickel may be found in prepared foods (tinned foods) at markedly higher concentrations than the safe threshold laid down for hypersensitive patients. Some foodstuffs cooked in stainless-steel utensils attack the metal and thus contain much more nickel than when enamel or aluminum saucepans are used. Among the natural organic acids which may be responsible for dissolving stainless-steel, oxalic acid is the most active at equivalent concentrations.

Cooking↗
PubMed1979

[Guinea pig nipple as a model for the investigation of melasma (author's transl)].

The nipples of male tan guinea pigs were used to test the effects on the skin of oral contraceptive pills and drugs. The daily topically applied doses were 1/2,000 of a pill. After 3 weeks, the nipples treated with solutions of ethinyloestradiol-containing pills had grown (200-300%), the epidermis showed acanthosis (150-250%) and strong hyperpigmentation. Mestranol-containing pills as well as pure progestogen substances did not produce these effects.

Animals↗
PubMed1979

[Alimentary nickel and contact eczema (author's transl)].

By atomic absorption spectrometry, nickel was analysed in many foodstuffs. The results of these determinations are given in detail. Nickel present in vegetables comes primarily from the soil but secondarily from stainless-steel cooking utensils.

Dermatitis, Contact↗
PubMed1978

[Hyperthyroidism in older patients].

This study comprises 81 thyrotoxic patients with onset after the age of 60. In elderly persons, toxic multinodular goiter is the most common cause (68%) of hyperthyroidism, followed by solitary thyroid nodules (16%) and Graves' disease (16%). Cardiovascular disorders (cardiac failure, arrythmias etc.) constitute the first and often the only symptom in 62% of the cases. The other forms of appearance are both various and deceptive: depression, slight fever, asthenia or nausea. Separate analysis of the three forms of hyperthyroidism did not reveal clinical, biological or therapeutic differences between them, except an inferior rate of captation for the toxic nodules. Isolated measurement of T3 or T4 is often insufficient to confirm the diagnosis because either of these hormones may appear at a normal rate. In three cases only the free thyroxin index was pathological on first determination. The authors have established that the autonomous nodules are larger and more active after, rather than before, 60 years of age, and have attempted to define their morphological identity. The results of the treatment are analyzed and preference is expressed for radioactive iodine in every form of hyperthyroidism.

Aged↗
PubMed1978

Effect of ethidium bromide on growth and morphology of Leishmania tarentolae promastigotes in vitro.

Incubation of Leishmania tarentolae promastigotes in 0.01 microgram/ml ethidium bromide in Neo Ye medium for 96 h resulted in 60% inhibition of cell growth and 91% dyskinetoplasty. After 48 h incubation in ethidium bromide over 50% of the cells were scored dyskinetoplastic by light microscopy although the electron microscopical examination revealed that most promastigotes contained at least a small amount of kDNA. A few of the treated cells undergoing division contained two kinetoplasts--one devoid of kDNA and the other with a reduced amount of kDNA as seen in the electron micrographs.

Ethidium↗
PubMed1977

Effect of berenil on growth, mitochondrial DNA and respiration of Leishmania tarentolae promastigotes.

Incubation of Leishmania tarentolae promastigotes in 1.0 microgram/ml Berenil for 96 hr resulted in approximately 33% inhibition of cell growth and approximately 42.5% dyskinetoplasty in the cell population. The buoyant density of kinetoplast DNA (kDNA), p = 1.703 g/ml, remained unchanged after 96-hr exposure to the drug. Endogenous respiration as well as proline- and glucose-induced respiration dropped markedly after 36-hr exposure to Berenil. This drop occurred approximately 12 hr before the onset of dyskinetoplasty, a result which suggests that this drug adversely affects mitochondrial respiratory activity of the promastigotes.

Amidines↗
PubMed1977

A new semi-defined medium for Trypanosoma brucei sspp.

A new, easy to prepare semi-defined medium for the cultivation of trypanosomes of the T. brucei complex is introduced. Containing the two commercially available media MEM (Minimum Essential Medium) and Medium 199 TC45 as well as 10% inactivated foetal calf serum (fcs), the medium supports optimum growth and direct adaptation of bloodstream forms. Growth characteristics, glucose uptake, amino acid utilization and the ultrastructure of trypanosomes grown in this medium are described briefly.

Amino Acids↗