Acetylation-dependent chromatin reorganization by BRDT, a testis-specific bromodomain-containing protein.

The association between histone acetylation and replacement observed during spermatogenesis prompted us to consider the testis as a source for potential factors capable of remodelling acetylated chromatin. A systematic search of data banks for open reading frames encoding testis-specific bromodomain-containing proteins focused our attention on BRDT, a testis-specific protein of unknown function containing two bromodomains. BRDT specifically binds hyperacetylated histone H4 tail depending on the integrity of both bromodomains.

Standardization of factor VII/activated factor VII measurement in plasma of patients treated with recombinant factor activated VII.

To improve the standardization of the factor VII clotting activity (FVII:C) assay in patients treated with recombinant activated factor VII (rFVIIa), we conducted a multicentre study on plasma samples from four patients with haemophilia A, before and at various times after injection of a single dose of rFVIIa. FVII:C and prothrombin time were measured with the methods and reagents routinely used in each laboratory. Strong inter-laboratory variability of FVII:C values was found.

Reassessment of von Willebrand factor (VWF), VWF propeptide, factor VIII:C and plasminogen activator inhibitors 1 and 2 during normal pregnancy.

The use of von Willebrand factor [VWF antigen (WF:Ag)] measurement as a marker of endothelial cell activation for monitoring hypertensive pregnancies is limited by the poor definition of reference values. We reassessed these reference values using different assays, and those of the propeptide (VWF:Ag II) and factor VIII coagulant activity (factor VIII:C), in a large population of normal pregnancies, at 3-week intervals of gestational age. Plasminogen activator inhibitors (PAI-1 and PAI-2) were measured in parallel.

A new ELISA assay for diagnosis of acquired von Willebrand syndrome.

The pathophysiology of acquired von Willebrand syndrome (AVWS), a rare bleeding disorder, is not fully understood. Circulating antibodies to Von Willebrand factor (VWF) are found in patients with AVWS associated with lymphoproliferative disorders but these autoantibodies are difficult to detect with routine laboratory tests and neutralisation assays. We have developed a simple enzyme-linked immunosorbent assay (ELISA) to detect serum antibody binding to VWF protein immobilized on polystyrene plates.

[Antiphospholipid antibodies in HELLP syndrome: clinical and biological study in 68 women].

Purpose: Pregnancy complicated by the HELLP syndrome and antiphospholipid syndrome have rarely been reported. We report a study on anticardiolipin antibodies in HELLP syndrome.

Methods: Between March 1996 and September 1999, anticardiolipin antibodies were checked in all women with HELLP syndrome hospitalised in a maternity of the North of France.

HDAC-6 interacts with and deacetylates tubulin and microtubules in vivo.

Microtubules are cylindrical cytoskeletal structures found in almost all eukaryotic cell types which are involved in a great variety of cellular processes. Reversible acetylation on the epsilon-amino group of alpha-tubulin Lys40 marks stabilized microtubule structures and may contribute to regulating microtubule dynamics. Yet, the enzymes catalysing this acetylation/deacetylation have remained unidentified until recently.

The viral control of cellular acetylation signaling.

It is becoming clear that the post-translational modification of histone and non-histone proteins by acetylation is part of an important cellular signaling process controlling a wide variety of functions in both the nucleus and the cytoplasm. Recent investigations designate this signaling pathway as one of the primary targets of viral proteins after infection. Indeed, specific viral proteins have acquired the capacity to interact with cellular acetyltransferases (HATs) and deacetylases (HDACs) and consequently to disrupt normal acetylation signaling pathways, thereby affecting viral and cellular gene expression.

Tip60 acetyltransferase activity is controlled by phosphorylation.

Here we show that the phosphorylation of histone acetyltransferase Tip60, a target of human immunodeficiency virus, type 1-encoded transactivator Tat, plays a crucial role in the control of its catalytic activity. Baculovirus-based expression and purification of Tip60 combined with mass spectrometry allowed the identification of serines 86 and 90 as two major sites of phosphorylation in vivo. The phosphorylation of Tip60 was found to modulate its histone acetyltransferase activity.

[Drug users attending at hospital emergency rooms. Changes in sociodemographic features, health care, referral attitudes and impact of substitution therapy, between 1993 and 1998].

The purpose of this work was to assess changes observed between 1993 and 1998 relative to drug users seen at hospital emergency rooms. We retrospectively reviewed our medical files for two periods, 1993-1995 and 1996-1998, i.e.

A blinded in vitro study with Refacto mock plasma samples: similar FVIII results between the chromogenic assay and a one-stage assay when using a higher cephalin dilution.

Assay of factor VIII (FVIII) in patient samples is routinely carried out using the one-stage assay rather than the chromogenic substrate assay. The introduction of new FVIII preparations for the treatment of haemophilia A, including immunopurified FVIII and particularly, recombinant FVIII (rFVIII) concentrates, has led to discrepancies between the results obtained with the two assays. In patients treated with rFVIII concentrates, FVIII levels measured with the one-stage assay can be 20-50% lower than those measured with the chromogenic assay.

Tat-controlled protein acetylation.

Human immunodeficiency virus, type 1-encoded transactivator protein Tat is known to be a substrate of and to interact with several nuclear histone acetyltransferases (HATs). Here we show that Tat is a general inhibitor of histone acetylation by cellular HATs and that for at least one of them, the CREB-binding protein (CBP), it induces a substrate selectivity. Indeed, in the presence of Tat, the acetylation of histones by CBP was severely inhibited, while that of p53 and MyoD remained unaffected.

Large experience with a factor VIII binding assay of plasma von Willebrand factor using commercial reagents.

The present diagnostic assay for type 2N von Willebrand disease (VWD) is based on the in vitro measurement of the capacity of plasma von Willebrand factor (VWF) to bind exogeneous factor VIII (VWF:FVIIIB). We report a method using only commercially available reagents that is easy to perform. This method has been validated in a cohort of 144 patients with FVIII/VWF ratios < 0.

Permeability and functionality of pancreaticogastrostomy after pancreaticoduodenectomy with dynamic magnetic resonance pancreatography after secretin stimulation.

Background: The aim of this study was to evaluate pancreatogastrostomy (PG) permeability after duodenopancreatectomy (PD) and to determine a correlation with pancreatic endocrine and exocrine functions.

Study Design: This prospective study included 19 patients who underwent PD with PG between 1992 and 1999. There were 12 men and 7 women, with a mean age of 58 years (range 35 to 76 years).

Evolution of DNA ploidy during squamous cell carcinogenesis in the esophagus.

Image and flow cytometry was used to study the nuclear DNA content (ploidy) during the squamous cell carcinogenesis in the esophagus. The present retrospective study comprised 26 surgical specimens of squamous cell carcinomas (SCC) in patients who underwent surgery alone at the Department of Surgery in CHUV Hospital in Lausanne, between January 1992 and December 1999. We analyzed 53 healthy tissues, 43 tumors, and six lymph node metastases.

Type 2N von Willebrand disease: clinical manifestations, pathophysiology, laboratory diagnosis and molecular biology.

Type 2N von Willebrand disease encompasses all patients with factor VIII deficiency caused by a markedly decreased affinity of von Willebrand factor for factor VIII. It is recessively inherited and clinically similar to mild haemophilia. The differential biological diagnosis is of major importance for providing the optimal treatment and relevant genetic counselling.

Gelatinase A (MMP-2) in developing tooth tissues and amelogenin hydrolysis.

Matrix metalloproteinases (MMPs) are thought to play important roles during enamel and dentin biomineralization. Previously, membrane type-1 matrix metalloproteinase (MT1-MMP) was localized to the plasma membranes of ameloblasts and odontoblasts of the developing tooth. The best-characterized function of MT1-MMP is to initiate the activation of gelatinase A (MMP-2).

Quantification of lupus anticoagulants in clinical samples using anti-beta2GP1 and anti-prothrombin monoclonal antibodies.

Quantification of lupus anticoagulant (LA) in clinical samples is hampered by the lack of a suitable standard of activity. We evaluated the use of mAbs displaying LA activity for this purpose. As most patient samples contain both beta2Glycoprotein I (beta2GP1) and prothrombin dependent LA, a combination of two mAbs, one of each specificity, was added to normal plasma in a concentration from 0 to 60 microg/ml.

The histone acetyltransferase, hGCN5, interacts with and acetylates the HIV transactivator, Tat.

Factor acetyltransferase activity associated with several histone acetyltransferases plays a key role in the control of transcription. Here we report that hGCN5, a well known histone acetyltransferase, specifically interacts with and acetylates the human immunodeficiency virus type 1 (HIV-1) transactivator protein, Tat. The interaction between Tat and hGCN5 is direct and involves the acetyltransferase and the bromodomain regions of hGCN5, as well as a limited region of Tat encompassing the cysteine-rich domain of the protein.

The C. elegans zyg-1 gene encodes a regulator of centrosome duplication with distinct maternal and paternal roles in the embryo.

Centrosome duplication is a critical step in assembly of the bipolar mitotic spindle, but the molecular mechanisms regulating this process during the cell cycle and during animal development are poorly understood. Here, we report that the zyg-1 gene of Caenorhabditis elegans is an essential regulator of centrosome duplication. ZYG-1 is a protein kinase specifically required for daughter centriole formation that localizes transiently to centrosomes and acts at least one cell cycle prior to each spindle assembly event.

Treatment of chronic hepatitis C with amantadine hydrochloride in patients who had not responded to previous treatment with interferon-alpha and/or ribavirin.

Seven women and 3 men infected with hepatitis C virus, all of whom had failed to respond to therapy with either IFN-alpha or IFN and ribavirin, were treated with 200 mg/day of amantadine hydrochloride for 12 months. We found a significant decrease of serum ALT activity without any decrease in virus load. These results suggest that amantadine hydrochloride should not be used as monotherapy for patients who do not respond to treatment with IFN-alpha and/or ribavirin.

Unbalanced X-chromosome inactivation with a novel FVIII gene mutation resulting in severe hemophilia A in a female.

This report is of a 14-month-old girl affected with severe hemophilia A. Both her parents had normal values for factor VIII activity, and von Willebrand disease type 2N was excluded. Karyotype analysis demonstrated no obvious alteration, and BclI Southern blot did not reveal F8 gene inversions.

[Percutaneous cholecystostomy in non-surgical patients].

Purpose: To assess the efficacy and complications of percutaneous cholecystostomy (PC) in the treatment of acute cholecystitis in non-surgical patients.

Materials And Methods: Retrospective study of 25 cases (16 males and 9 females) of PC. The average age was 82 years (range: 59-95).

Significant linkage for Tourette syndrome in a large French Canadian family.

Family and twin studies provide strong evidence that genetic factors are involved in the transmission of Gilles de la Tourette syndrome (TS) and related psychiatric disorders. To detect the underlying susceptibility gene(s) for TS, we performed linkage analysis in one large French Canadian family (127 members) from the Charlevoix region, in which 20 family members were definitely affected by TS and 20 others showed related tic disorders. Using model-based linkage analysis, we observed a LOD score of 3.