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Biomedical subjects

A Tran

Publications and source records attributed to A Tran.

83 records · Page 5Linked to original sources
PubMed1992

Separate induction of human blood platelet aggregation or cytotoxicity by different concentrations of PAF-acether and thrombin.

Using decreasing concentrations of PAF-acether or thrombin, it was possible to observe on human platelets, first, aggregation, classically associated to activation, then , below a threshold, cytotoxicity towards Schistosoma mansoni larvae, proposed here as stimulation. These two activities appeared as distinct and antithetic. However, their induction might be the consequence of triggering of the same receptors with different intensity, since PAF-induced, but not thrombin-induced, cytotoxicity could be inhibited with specific PAF-antagonists BN 52021 and BN 52024 also known to inhibit PAF-induced aggregation. These results give credit to the hypothesis that haemostatic and cytotoxic properties of platelets are two distinct functions of these blood elements.

Animals↗
PubMed1992

Hepatitis C virus and Hashimoto's thyroiditis.

We report two cases of Hashimoto's thyroiditis associated with chronic active hepatitis C virus (HCV). Our data suggest that HCV infection might be involved in this autoimmune disease.

Adult↗
PubMed1991

[Excision of bronchogenic cyst by video-thoracoscopy].

We report what is probably the first case of para-oesophageal bronchogenic cyst treated by video-thoracoscopy. The patient was a 26-years old woman who presented with dysphagia to solid foods. Preoperative investigations showed that the lesion was a cyst and that it was located in the superior and posterior mediastinum; they also enabled us to determine its relations with nearby structures, notably the oesophagus, and to make the diagnosis of para-oesophageal bronchogenic cyst. Treatment consisted of excision of the cyst by video-thoracoscopy. The postoperative period was uneventful, and the patient was discharged on the fourth day.

Adult↗
PubMed1991

Emergence of and takeover by hepatitis B virus (HBV) with rearrangements in the pre-S/S and pre-C/C genes during chronic HBV infection.

We have shown, by analyzing serial serum samples from a chronic hepatitis B virus (HBV) carrier, the emergence of HBV DNA molecules with nucleotide rearrangements in the pre-S/S and pre-C/C genes. Serum samples were obtained at four different times (1983, 1985, 1988, and 1989) from an HBsAg- and HBeAg-positive carrier with chronic hepatitis. The polymerase chain reaction was used to amplify the pre-S/S and pre-C/C genes. The amplified products were cloned, and 8 to 10 independent clones were sequenced. In 1983 and 1985 only one type of HBV DNA molecule was observed. Nucleotide divergence relative to the adw2 subtype was 4.7, 7.2, and 1.6%, for the pre-S1, pre-S2, and S regions, respectively, and 2.2 and 3.9% for the pre-C and C regions, respectively. In 1988 and 1989, HBV DNA forms with marked rearrangements of both the pre-S/S and pre-C/C regions were evidenced. In the pre-S/S region, they comprised two distinct HBV DNA molecules. The first showed nucleotide divergence of 20.4, 14.8, and 3.3% for the pre-S1, pre-S2, and S regions when compared with the adw2 sequence. In addition, nucleotide deletions in the pre-S1 region led to the appearance of a stop codon. The second was created by recombination between the original and mutated HBV DNA. In the pre-C/C region, the mutated viral DNA showed 11.7% divergence when compared with the adw2 sequence. A point mutation led to the creation of a stop codon in the pre-C region, together with an insertion of 36 nucleic acids in the core gene. Most of this DNA insertion was identical to that reported in an independent HBV isolate but showed no significant homology with known sequences. Semiquantitative estimation of the proportion of wild-type and mutated HBV DNA molecules showed a marked increase in the mutated forms during the period of follow-up. Sucrose gradient analysis indicated that the defective HBV DNA molecules were present in circulating virions. Western immunoblot analysis showed the appearance of modified translation products. Our findings thus indicate the emergence of and gradual takeover by mutated HBV DNA forms during the HBV chronic carrier state. The rearrangements we observed in the pre-S/S and pre-C/C genes might lead to changes in the immunogenicity of the viral particles and thus affect the clearance of the virus by the immune system.

Amino Acid Sequence↗
PubMed1983

Noninvasive intracranial pressure measurement in the newborn.

A pneumatic applanation tonometer designed for intraocular pressure measurement was modified to measure intracranial pressure (ICP) over the open anterior fontanel in well and sick newborn infants. The device consists of a sensing unit, a pneumatic-to-electric transducer, an amplifier, and a recording unit. Intracranial pressure in the first three days of life in 35 normal term infants was 5.3 +/- 1.3 mm Hg (mean +/- SD) and in 25 normal preterm infants was 5.1 +/- 0.9 mm Hg. Significant elevations in uncomplicated respiratory distress syndrome (6.9 +/- 2.8 mm Hg) and in infants with complicated respiratory distress syndrome (10.1 +/- 3.1 mm Hg). In a group of sick term infants, intracranial pressure measurements were also significantly elevated (14.3 +/- 10.1 mm Hg). This monitor is simple, quick to calibrate and use, capable of reproducible results, and well suited for use in the intensive care unit.

Female↗
PubMed1979

Distribution of estradiol receptor and vitellogenin gene in chick liver chromatin fractions.

The distribution of estradiol receptor and vitellogenin gene was studied in estradiol stimulated chick liver chromatin fractions prepared by limited DNAse II digestion and MgCl2 precipitation. The receptor was found in all fractions, undigested chromatin (P1), Mg2+ insoluble chromatin (P2) and Mg2+ soluble chromatin (S2). This last fraction was rich in acidic proteins, had a high protein:DNA ratio (7.0 w/w), contained 28% of rapidly labelled RNA, 20% of the receptor, 3-5% of chromatin DNA and showed a 2 fold enrichment of vitellogenin DNA sequences over unfractionated chromatin as well as P1 and P2 DNA. On isopycnic metrizamide gradients, all chromatin fractions showed a receptor peak banding at 1.23 g/cm3, the density of nucleoproteins. Hybridization experiments showed that the DNA banding at this density in fraction S2 was enriched 4 fold in vitellogenin DNA sequences over unfractionated chromatin as well as P1 and P2 DNA. These results suggest an association of hormone receptor complex with nucleoprotein structures of an apparently active chromatin fraction.

Animals↗
PubMedDate not supplied

Non invasive prediction of severe fibrosis in patients with alcoholic liver disease.

OBJECTIVES: The aim of this study was to assess the diagnostic accuracy of noninvasive markers of liver fibrosis in alcoholic liver disease. PATIENTS AND METHODS: Fifty-four clinical and biochemical parameters including serum fibrosis markers (hyaluronate and transforming growth factor beta1) were analyzed in 146 consecutive heavy drinkers (106 men, 40 women; mean age 49.2 years). Following liver biopsy, fibrosis was evaluated using a semi-quantitative scoring system (no fibrosis (0) to severe fibrosis (3 + )). Multivariate analysis was performed to determine the markers that were best correlated with the fibrosis score. RESULTS: Fifty-nine patients (40.4 %) had severe fibrosis (3 +) while 87 (59.6 %) had no fibrosis or moderate fibrosis (0 to 2 +). In multivariate analysis, serum hyaluronate and the prothrombin index were the best markers for the prediction of severe fibrosis. Hyaluronate and the prothrombin index had a diagnostic accuracy of 91.1 % and 89.7 %, respectively in the whole population. Finally, a significant negative correlation was found between hyaluronate and the prothrombin index (r =- 0.86, P <0.0001). CONCLUSIONS: Using only hyaluronate and the prothrombin index, 9 out of 10 alcoholic patients can be correctly classified according to the severity of liver fibrosis.

Adult↗