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Biomedical subjects

J Fontan

Publications and source records attributed to J Fontan.

9 recordsLinked to original sources
PubMed1999

[Human Herpesvirus 6: general information and infections in organ transplantations and hematopoietic stem cell grafts].

GENERAL DATA: Human herpesvirus 6 (HHV-6) infects 90% of the human population before the age of 4 years, recognized as a childhood disease (sixth disease) or with no clinical manifestation. HHV-6 DNA has partial homogly with cytomegalovirus DNA. Two variants, A and B, are known. The main target cells are CD4+ T cells and macrophages via a partially elucidated mechanism. Primary infection is followed by a latency period and episodes of reactivation. Truly protective targets of the immune response are unknown. POORLY UNDERSTOOD NATURAL HISTORY: In organ transplant or hematopoietic stem cell recipients, the natural history of HHV-6 infection is difficult to establish because of small sample size in certain series, the lack of controls both for patients and samples and differences in the sensitivity of diagnostic tests. Serology is non-specific and cannot be used to study reinfection. Different studies have relied on culture and isolation, detection of viral antigens with monoclonal antibodies and PCR using mononucleated cells, serum and plasma. PATHOGENICITY: In heart transplant recipients, HHV-6 infection can cause hepatitis and pancreatic or upper digestive tract disorders. It has also been suggested that HHV-6 could cause complications in liver transplant recipients and be involved in rejection episodes after kidney transplantation. In bone marrow graft recipients, HHV-6 could cause early onset interstitial pneumopathy, myelosuppression phenomena and aggravated graft versus host reactions. Nevertheless, viral DNA has been found in certain healthy controls. OTHER POSSIBILITIES: HHV-6 could also be a co-factor worsening cytomegalovirus infections as has been suggested in liver, heart and bone marrow recipients. A few cases of HHV-6 encephalitis have been reported in the literature and would appear to be authentic in transplanted or grafted subjects. Ganciclovir is effective. However, the practical clinical impact of HHV-6 infection remains to be established.

Hematopoietic Stem Cell Transplantation↗
PubMed1999

Low dose T-cell lymphocyte infusion combined with marrow T-cell depletion as prophylaxis of acute graft vs host disease for HLA identical sibling bone marrow transplantation.

T-cell depletion (TCD) of the bone marrow graft remains the most effective method to prevent severe graft versus host disease after allogeneic bone marrow transplantation. Early studies of HLA-identical sibling transplants showed that although T-cell depletion decreased GVHD, T-cell depleted transplants had higher risks of graft failure and leukemia relapse, leukemia free survival (LFS) was not improved compared to non-T-cell depleted transplants. In order to avoid graft failure and increased risk of relapse associated with this approach, we initiated a pilot study of T-cell depletion of the marrow graft combined with reinfusion of a fixed quantity of CD2+ peripheral blood T-cells. Depletion technique consisted in negative purging using CD2 and CD7 monoclonal antibodies (MoAbs) followed by rabbit complement cytolysis. This approach was associated with an intensified conditioning regimen using total body irradiation, high-dose cytosine arabinoside and melphalan (TAM) for all but one patient. Twenty-one patients were included with a mean age of 40 years. Only one acute severe Graft Versus Host Disease (GVHD) was observed and all patients engrafted. At 63 months, probability of survival is 42.86% with a relapse risk of 19.89%, two patients died from B-cell lymphoproliferative disease, seven other died from the procedure partially because of the use of the TAM as pretransplant regimen. This approach is being pursued by a gene therapy trial using herpes-simplex - 1 thymidine kinase gene expressing peripheral donor T-cells.

Adult↗
PubMed1995

[Listeriosis in patients with malignant hemopathy. 3 cases in the same hospital ward].

During the listeriosis epidemic which occurred in France in the summer 1992, three patients with malignant haematopathies hospitalized in our service contracted the disease. Although the retrospective investigations were hindered by the variable incubation period and the impossibility of examining the foods eaten at the time of infection, there was a high probability that two of the patients had been infected by cooked ham and dairy products at home. The third patient was apparently infected in hospital with well-cooked food found to be contaminated. The hypothesis of coinfection has been raised.

Aged↗
PubMed1988

Respiratory function in flour-mill workers.

The frequency of bronchial symptoms and the alteration of respiratory function parameters were studied in a group of 63 workers of an industrial flour-mill, and in a control group matched according to age, social class, and tobacco intake. In the exposed group the answers to a questionnaire indicated a greater incidence of cough (p less than 0.01) and chronic expectoration (p less than 0.01) as well as clinical airway hyperreactivity (p less than 0.01). No differences were noted for either asthma or allergy. The respiratory function parameters did not differ between the two groups studied. These results suggest that workers exposed to the vegetable dust found in fluor-mills are subject to develop chronic bronchial irritation.

Adult↗