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Biomedical subjects

T N Tran

Publications and source records attributed to T N Tran.

24 records · Page 2Linked to original sources

[Implications for genetic counselling in regard to sex chromosome aneuploidies diagnosed by amniocentesis (author's transl)].

It is in the detection of chromosomal aneuploidies that amniocentesis currently renders the greatest service. However, when an anomaly of the fetal sex chromosomes is found, the decision of what attitude to hold in counselling the parents poses a real dilemma, due to the importance of phenotypic variation-notably of intelligence and behavior-in individuals with sex chromosome disorders. It is in such situations that the need for information furnished by prospective studies is particularly evident. Prenatal diagnosis of four cases of sex chromosomal polysomy, detected in the course of approximately 600 amniocenteses, is presented, as are the criteria which may guide the parents in their decision to continue or to terminate a pregnancy so affected.

Amniocentesis↗

[Significance of chromosomal mosaicism diagnosed by amniocentesis].

Second-trimester amniocentesis, performed in a 39-year-old woman, revealed on two different taps a weak aneuploid cell line 47,XY+C or X (2 clones), with a strong majority of fetal cells being 46,XY normal (15 clones). A chromosome examination carried out on cord blood after the birth of a phenotypically normal infant confirmed the presence of mosaicism, with 12% of the cells being 47,XXY. The authors consider the manner in which mosaicism diagnosed by amniocentesis may be interpreted, pointing out the danger of hasty conclusions in this domain, which has not yet been adequately explored.

Adult↗

TRH stimulates the release of POMC-derived peptides from goldfish melanotropes.

The release of immunoreactive (ir) alpha-MSH and ir ACTH from goldfish (Carassius auratus) melanotropes was investigated using superfused isolated dispersed neurointermediate lobe cell columns. Stimulation of neurointermediate lobe cell columns with pulses of TRH evoked dose-dependent increases in the concomitant release of ir alpha-MSH and ir ACTH. Reversed-phase high performance liquid chromatography (RP-HPLC) was used to characterize the alpha-MSH and ACTH immunoreactivities released from a neurointermediate cell column under spontaneous release conditions. Six peaks of ir alpha-MSH were revealed. Three of these peaks were identified as des-acetyl alpha-MSH, mono-acetyl alpha-MSH and di-acetyl alpha-MSH. Seven peaks of ir ACTH were revealed. Four of these peaks were tentatively identified as ACTH variants. These studies suggest that TRH stimulates the release of peptide hormones from teleost melanotropes and that the goldfish neurointermediate lobe in vitro releases numerous peptides derived from POMC.

Adrenocorticotropic Hormone↗

Comparison of artemisinin suppositories, intramuscular artesunate and intravenous quinine for the treatment of severe childhood malaria.

Severe malaria remains a major cause of mortality and morbidity for children living in many tropical regions. With the emergence of strains of Plasmodium falciparum resistant to both chloroquine and quinine, alternative antimalarial agents are required. The artemisinin group of compounds are rapidly effective in severe disease when given by intramuscular or intravenous injection. However, these routes of administration are not always available in rural areas. In an open, randomized comparison 109 Vietnamese children, aged between 3 months and 14 years, with severe P.falciparum malaria, were allocated at random to receive artemisinin suppositories followed by mefloquine (n = 37), intramuscular artesunate followed by mefloquine (n = 37), or intravenous quinine followed by pyrimethamine/sulfadoxine (n = 35). There were 9 deaths: 2 artemisinin, 4 artesunate and 5 quinine-treated children. There was no difference in fever clearance time, coma recovery, or length of hospital stay among the 3 groups. However, parasite clearance times were significantly faster in artemisinin and artesunate-treated patients than in those who received quinine (P < 0.0001). Both artemisinin and artesunate were very well tolerated, but children receiving these drugs had lower peripheral reticulocyte counts by day 5 of treatment than those in the quinine group (P = 0.011). No other adverse effect or toxicity was found. There was no treatment failure in these 2 groups, but 4 patients in the quinine group failed to clear their parasites within 7 d of starting treatment and required alternative antimalarial therapy. Artemisinin suppositories are easy to administer, cheap, and very effective for treating children with severe malaria. In rural areas where medical facilities are lacking these drugs will allow antimalarial therapy to be instituted earlier in the course of the disease and may therefore save lives.

Adolescent↗

Pharmacokinetics of oral artesunate in children with moderately severe Plasmodium falciparum malaria.

The pharmacokinetic properties of oral artesunate (3 mg/kg) were determined in 10 Vietnamese children, aged from 6 to 15 years, with acute falciparum malaria of moderate severity. Plasma concentrations were measured using a bioassay and expressed in terms of antimalarial activity equivalent to dihydroartemisinin, the principal biologically active metabolite. Oral artesunate was absorbed rapidly with a mean time to peak plasma bioactivity of 1.7 h (95% confidence interval [95% CI] 0.8-2.6). There was wide variation in peak plasma concentrations with a mean value equivalent to 664 ng of dihydroartemisinin/mL (95% CI 387-9410, range 179-1395) and a four-fold variation in the area under the plasma concentration-time curves. Elimination from plasma was rapid with a mean (95% CI) half-life of 1.0 h (95% CI 0.8-1.4). Plasma antimalarial levels were below the limit of detection in all cases by 12 h, despite the relatively high dose of artesunate used. Oral artesunate is rapidly absorbed and rapidly eliminated in children with moderately severe malaria but there is considerable variation between individuals.

Administration, Oral↗