Search PubMed⌕ Search

Biomedical subjects

B Dupont

Publications and source records attributed to B Dupont.

At least 127 records · Page 7Linked to original sources
PubMed1996

New HLA-DR haplotypes containing the DRB6 pseudogene.

An unexpected probe reaction pattern was observed in two samples during HLA-DR typing by PCR-Sequence Specific Oligonucleotide Probes. In order to confirm the unusual typings, samples were analyzed by PCR-Sequence Specific Primers, cloning, and nucleotide sequencing of the second exon of the HLA-DRB-genes. The confirmed DR, DQ phenotype for one sample was DRB1*0701, DRB4*01, DRB5*0101, DRB6*0201, DQB*0602, DQB1*0202. The phenotype of other sample was DRB1*1602, DRB1*1302, DRB3*0301, DRB6*0101, DQB1*0501, DQB1*0502. The first sample has the novel combination of DRB1*0701 with DRB5*0101 and DRB6*0201. The second sample has either DRB6*0101 together with DRB1*1602 in absence of any DRB5 allele or DRB6*0101 together with DRB1*1302, DRB3*0301. We postulate that the most likely haplotype in sample #1 is DRB1*0701; DRB5*0101, DRB1*0602 which could have arisen from gene conversion. The most likely haplotype in sample #2, DRB1*1602, DRB6*0101, DQB1*0502 would have arisen from an homologous recombination event.

HLA-DR Antigens↗
PubMed1996

[Primary non-Hodgkin's lymphomas of the liver in human immunodeficiency virus infected patients. Three cases].

The occurrence of primary non Hodgkin's lymphoma of the liver has rarely been reported in patients with the human immunodeficiency virus infection. We report 3 cases in these patients, presenting with a single liver tumor in 2 cases and multiple tumors in one case. Diagnosis was made by guided-biopsy. Histologically, there was B diffuse large cell lymphoma in 2 cases, and immunoblastic lymphoma in one case. In one case, RNA of Epstein-Barr virus was found in the nucleus of tumor cells by in situ hybridization. No extrahepatic localization was found in any of the 3 cases. One patient died one week after diagnosis, but the 2 other patients were treated by chemotherapy and were still alive 6 and 30 months later. In patients infected by human immunodeficiency virus, primary non Hodgkin's lymphoma should be investigated in case of liver tumor in order to provide early treatment.

AIDS-Related Opportunistic Infections↗
PubMed1995

Novel isoforms of murine intercellular adhesion molecule-1 generated by alternative RNA splicing.

Intercellular adhesion molecule-1 (ICAM-1)-deficient mice, produced by homologous recombination and previously recognized to be devoid of the common form of ICAM-1, are shown to express residual amounts of ICAM-1 Ag in thymus and lung. We demonstrate that this expression of ICAM-1 is possible because the mutated exon 5 in these animals has been skipped by alternative splicing of RNA. Three different alternative isoforms of ICAM-1 are expressed in mutant mice. Moreover, two of these isoforms are expressed in wild-type mice together with two additional alternative isoforms that cannot be produced in mutant mice. All alternatively spliced isoforms of ICAM-1 detected are missing complete extracellular Ig domains. In both mutant and wild-type mice, expression of alternatively spliced isoforms is up-regulated following stimulation of animals with LPS. Furthermore, all alternative isoforms of ICAM-1, except one, retain the ability to bind to the well-recognized ICAM-1 counter-receptor LFA-1. These findings, along with the restricted tissue distribution in mutant mice, indicate that alternative isoforms of ICAM-1 are significant physiologic adhesion structures which could play a distinct role in the functioning of the immune system of intact animals.

Alternative Splicing↗
PubMed1995

[Infectious complications of implantable catheters in HIV infected patients. Retrospective study of 46 patients].

OBJECTIVES: Investigate the rate of infection in HIV positive patients with an implantable venous access device. METHODS: Forty-six totally implantable venous access devices (port-a-cath, PAC) were inserted in 46 HIV infected patients between January 1990 and May 1992. We analyzed the rate of infectious complications and tried to find predictive factors. RESULTS: There were five infectious complications in five patients. The total complication rate was 0.06 per 100 catheter days. Staphylococcus aureus was responsible in two cases, Staphylococcus epidermidis was responsible in one case and Acinetobacter in one case. No predictive factor was recognized. CONCLUSION: The rate of PAC infection was lower than in other published studies concerning HIV-infected patients. Totally implantable central venous access devices play an increasingly important role in the clinical management of HIV-related diseases. We have shown that the PAC device is safe and convenient in HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed1995

Successful treatment of a brain abscess due to Trichoderma longibrachiatum after surgical resection.

A case of brain abscess due to Trichoderma longibrachiatum in a leukemic patient with prolonged neutropenia is reported. Definitive cure was achieved after neurosurgical resection of the abscess and prolonged antifungal therapy. Trichoderma is a filamentous fungus species, which is only exceptionally pathogenic in humans. This genus and particularly the species Trichoderma longibrachiatum should be added to the growing list of fungi causing infection in immunocompromised patients.

Adolescent↗
PubMed1995

Value of liver biopsy for the rapid diagnosis of infection in human immunodeficiency virus-infected patients who have unexplained fever and elevated serum levels of alkaline phosphatase or gamma-glutamyl transferase.

We prospectively determined the value of liver biopsy for microbiological diagnosis of infection in patients infected with the human immunodeficiency virus (HIV) who had unexplained fever and whose serum levels of alkaline phosphatase or gamma-glutamyl transferase were at least 1.5 times the upper limit of normal. From December 1989 to December 1991, 108 HIV-infected patients were referred to the Liver Unit at Hôpital Laënnec (Paris) with liver abnormalities related to viral hepatitis (generally chronic), AIDS-related sclerosing cholangitis, or nonspecific lesions (detected on histologic examination). Twenty-four patients had unexplained fever and increased levels of alkaline phosphatase or gamma-glutamyl transferase, and none had evidence of hepatobiliary disease. All 24 patients had undergone routine microbiological tests to determine the cause of their chronic fever. The results of all microbiological tests were negative. We performed liver biopsies for these 24 patients and examined the specimens by means of standard direct microbiological techniques; in addition, the specimens were cultured, the specimens were analyzed by standard histopathologic methods, and specific histologic studies for fungi, mycobacteria, and viruses were performed. A microbiological diagnosis was made in 13 (54%) of the 24 cases within 12 hours to 3 days of the liver biopsy. In conclusion, liver biopsy is a powerful diagnostic tool for rapid diagnosis of infection in HIV-infected patients who have unexplained fever and abnormal liver function test results.

AIDS-Related Opportunistic Infections↗
PubMed1995

Brain stem encephalitis due to varicella-zoster virus in a patient with AIDS.

We describe a patient infected with human immunodeficiency virus (HIV) who had localized brain stem encephalitis due to varicella-zoster virus (VZV) and no cutaneous eruption. Diagnosis of the infection was based on the presence of Cowdry type A intranuclear inclusions in neurons, astrocytes, and oligodendrocytes positive for VZV (as shown by immunochemical staining). Although this infection is rare, we demonstrate the need for clinicians to include VZV infection in the differential diagnosis of rapidly progressive multiple cranial nerve palsies in HIV-infected patients, particularly because specific treatment for VZV infection is effective and relatively safe.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Activation of extracellular signal-regulated protein kinase (ERK/MAP kinase) following CD28 cross-linking: activation in cells lacking p56lck.

T lymphocytes require two signals for activation. Recognition of antigen/MHC complexes by the T cell receptor delivers the first signal, while a second signal, delivered by the cell surface receptors CD80 and/or CD86 binding to the T cell surface molecule CD28, has been shown to be effective for the initiation of effective T cell responses. While some of the cytoplasmic effector molecules involved in T cell receptor signaling is known, little is known regarding those involved in the co-stimulation of T cells by CD28. Using the T cell leukemic cell line Jurkat as a model for T cell activation, we demonstrate that cross-linking CD28 using monoclonal antibodies causes tyrosine phosphorylation and activation of MAP kinase/ERK. This activation was rapid, peaking at approximately 5 minutes post CD28 cross-linking, and transient. Activation of MAP kinase/ERK occurred 3 fold less efficiently in a Jurkat line lacking functional p56lck (JCAM.1), and was almost undetectable in a line lacking CD45 (J45.01). These results suggest that CD28 cross-linking can activate intracellular signaling pathways via several different tyrosine kinases. Thus CD28 signaling can activate src family kinases lck and fyn, as well as the Tec family kinase emt/itk. Activation of any one or a combination of these tyrosine kinases may be sufficient for the activation of MAPK following CD28 cross-linking. Activation of MAPK has been shown to cause activation of AP-1 and other transcription factors via serine and/or threonine phosphorylation.(ABSTRACT TRUNCATED AT 250 WORDS)

CD28 Antigens↗
PubMed1995

Fluconazole concentrations in saliva from AIDS patients with oropharyngeal candidosis refractory to treatment with fluconazole.

Fluconazole (FCZ) has been extensively used as a primary therapy for oropharyngeal candidosis in AIDS patients. Clinical resistance to FCZ is now encountered, often related to decreased susceptibility of the isolate in vitro. We wondered if low levels in saliva play a role in the therapeutic failure, especially in patients complaining of dry mouth. Sixteen AIDS patients treated for oropharyngeal candidosis with FCZ were studied. MICs for the isolates were determined. Serum and saliva samples were collected to measure FCZ levels with a bioassay using paper disks loaded with the clinical specimens. We showed that (i) paper disks were convenient for collecting saliva in patients with dry mouth; (ii) levels in saliva depended on the FCZ dosage regimen but did not correlate with the response to therapy; (iii) correlation between concentrations in saliva and serum was poor and independent of clinical response to treatment, other therapies, or decreased salivation; and (iv) levels in saliva were always lower than MICs in patients who failed to respond to treatment. In conclusion, therapeutic failures are more likely to be related to in vitro resistance of the isolate to FCZ or insufficient dosage regimen than to decreased salivary secretion.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Balint's syndrome.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗