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Biomedical subjects

P Lebon

Publications and source records attributed to P Lebon.

At least 91 records · Page 5Linked to original sources
PubMed1993

Rotavirus induces alpha-interferon release in children with gastroenteritis.

alpha-Interferon (IFN) blood levels were studied in 38 children hospitalized for rotavirus gastroenteritis. During rotavirus infection, a peak of systemic alpha-IFN was observed within 2 days of onset of symptoms. There was a significant positive correlation between alpha-IFN levels and the number of vomiting episodes (p = 0.0003) but not with duration of vomiting, maximal temperature, and duration of fever. alpha-IFN levels were higher in children with peripheral cyanosis compared with children without peripheral cyanosis (p = 0.005) and tended to be higher in children with diarrhea of < 3 days' duration compared with those with diarrhea lasting > 4 days (p = 0.06). alpha-IFN could be partly responsible for the severity of such initial symptoms as vomiting and peripheral cyanosis in rotavirus gastroenteritis and could play a role in recovery from diarrhea.

Female↗
PubMed1993

[Herpes encephalitis in newborn infants. Retrospective study of 12 cases].

BACKGROUND: Herpes simplex virus (HSV) may cause severe disease in neonates with high mortality and devastating sequelae. Adenine arabinoside (ara-A) and acyclovir can be effective in treating the neonatal disseminated disease, but optimal doses of the drugs are still debated. PATIENTS: The files of 12 neonates treated for HSV infection between May 1983 and April 1989 in 9 departments of pediatrics were studied. The following data were analysed: age at initial signs, clinical manifestations, CSF abnormalities, viral and immunological studies, imaging techniques used to detect brain damage, doses and duration of treatment. RESULTS: The mean age at the first infectious signs was 12.3 +/- 9.3 days and neurological manifestations were first seen at 18.3 +/- 7.7 days. Acyclovir was given intravenously for 2 to 4 weeks at doses of 30 mg/kg/24 hr (5 patients) or 60 mg/kg/24 hr (7 patients) at an average of 7.7 days after the first clinical manifestations. The initial dose of 30 mg/kg/24 hr was increased to 50 or 60 mg/kg/24 hr in 3 patients. Five patients died during treatment, and 5 had severe sequelae; follow-up for the 2 remaining patients was not possible. There was no correlation between prognosis and the dose of acyclovir, which was well tolerated in all patients. CONCLUSIONS: The best results are obtained when treatment is started early. This retrospective study failed to show any dose-dependent difference in the efficacy of acyclovir. A prospective study with different doses would be useful.

Acyclovir↗
PubMed1992

HIV replication during the first weeks of life.

Diagnosis of HIV infection among children born to HIV-positive mothers can be made in the first 12 months, but few studies have examined HIV status during the first weeks of life. In a prospective longitudinal study of 50 infants born to HIV-1 seropositive women, blood samples were obtained at birth and at 4-9 weeks and 5-9 months of age, and were tested for HIV-1 by the polymerase chain reaction (PCR), viral culture, and p24 antigen measurements. 16 were diagnosed as HIV-infected by the age of 4-9 weeks according to both PCR and culture; by contrast, infection could be detected in only 5 children at birth. No changes in HIV status were observed between 4-9 weeks and 5-9 months in the 44 children who could be retested. Perinatal HIV-1 infection can therefore be diagnosed in the first 2 months of life, either by PCR or viral culture. Our inability to detect HIV-1 infection at birth in almost 70% of babies subsequently found infected suggests an active replication of HIV during the first weeks of life. Our results might favour the hypothesis that transmission of HIV-1 takes place either at the end of pregnancy or at delivery.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Underestimation of the incidence of measles in a population of French children.

Data on titres of specific antibodies against measles virus and information given by families and physicians were analysed in 133 vaccinated and 117 unvaccinated children. Only 2 of the 133 vaccinated children reported a history of measles, while 131 had detectable levels of antibodies. Measles antibodies were detected in 102 (87.2%) of the unvaccinated children, but a history of measles diagnosed clinically by a physician was reported in only 42 of them. These findings suggest that subclinical cases of measles are possible and contribute to the high circulation of the measles virus in the child population in France.

Adolescent↗
PubMed1992

Immunogenicity of combined anti-HIV and anti-suppressive vaccine preparations.

HIV-1 antigens generate in man both a humoral and cellular immune reaction. However, in ARC/AIDS patients, the cellular response is inhibited by HIV-1 which induces an antiproliferative (suppressive) effect on activated T cells. To overcome this inhibition and up-regulate the cellular response, we designed a new vaccine strategy directed both against HIV-1 and immunosuppression and we used an immunizing preparation composed of HIV-1 antigens combined with immunoregulatory peptides prepared in a biologically inactivated but immunogenic form. In mice, this preparation induced anti-HIV-1 antibodies and a cell-mediated cytotoxicity directed against H2 restricted cells carrying HIV-1 antigens.

Animals↗
PubMed1992

Absence of intrathecal synthesis of some interferon-alpha subtypes in bacterial meningitis.

Sixty-five cerebrospinal fluid (CSF) samples from 54 infants and children with bacterial meningitis were analyzed for the presence of interferon (IFN)-alpha with a biologic assay. Of the 65 samples, 3 were positive (2-4 IU/mL) and only 1 of 56 collected early was at 4 IU/mL. These results suggest that some subtypes of IFN-alpha already reported as present in viral infections of the central nervous system are not detected in bacterial meningitis by our IFN assay. This difference may be helpful in differentiating bacterial from viral infections and also in evaluating the quality of the virologic investigation; moreover, the rarity of IFN-gamma in CSF in bacterial meningitis needs further investigation to understand its role in the pathogenesis of the disease.

Child↗
PubMed1992

[Immunity to and incidence of measles in a population of Parisian children].

BACKGROUND: Measles remains prevalent in France despite the development of nationwide vaccination program. This study evaluates measles immunity and correlates it with active immunization. MATERIAL AND METHODS: A total of 250 (131 boys and 119 girls) French children, aged 2 to 15 years, seen as outpatients in our hospital, were studied from 1.01.90 to 1.06.91; 133 had received live measles vaccine during the 2nd year of life, the 117 others were not vaccine-protected. Evaluation included medical records, specially those concerning past-history of measles or measles-like diseases and immunizations. Measles IgG and IgM antibodies (ELISA) were looked for in all 250 children. RESULTS: 102 of the 117 children who were not vaccine-protected had a detectable antibody titer. 42 of these 102 had a history of measles, before the age of 5 years in 30, between 5 and 10 years in 9 and after the age of 10 years in 3. Only 4 of the 70 children aged over 10 years and not vaccine-protected had no detectable antibodies. 131 of the 133 actively immunized children had detectable antibodies. CONCLUSIONS: Measles is probably more frequently subclinical than was believed until now. Its relative frequency in France in children who had not received the live vaccine explains the high percentage of those aged over 10 years who had detectable antibodies and the relatively low incidence of the disease in teenagers and young adults.

Adolescent↗
PubMed1992

[Cytomegalovirus infections in patients after liver transplantation: determination of risk groups].

The goal of this study was to identify high-risk groups for cytomegalovirus infection after liver transplantation. Sixty-one patients were evaluated. Twenty-five patients (41 percent) had infection. Among the 16 patients who were seronegative for the virus before transplantation, 11 received a liver graft and blood products from seronegative donors and none of them developed infection. All seronegative recipients of a liver from seropositive donors (5/5) developed primary infection. Among the 45 patients seropositive before transplantation, 20 developed a cytomegalovirus infection, whatever the donor serologic status. The incidence of symptomatic reactivation or reinfection was high (14/20), and, for 12/14 of them, associated with early acute rejection. Two high-risk groups of patients, eligible for cytomegalovirus prophylaxis, were identified: seronegative recipients of seropositive donors and seropositive recipients with early acute rejection.

Adolescent↗
PubMed1992

[Neonatal herpes: recurrence after treatment with acyclovir].

A case of cutaneous herpes relapse with meningitis is reported in a 1.5 month-old infant treated during the first three weeks of life with acyclovir (ACV) for a neonatal herpes infection. Such a relapse has previously been described in older children as well as in adults. In this case report, there was immunological response to herpes virus infection, 2.5 months after the onset of the infection. The relapse is discussed taking into account the mechanism of action of ACV, the age of the patient and the immunological response profile. Because of the high risk of neurological involvement, we suggest that the relapse should be treated with ACV for a period of time longer than actually recommended.

Acyclovir↗
PubMed1992

Intrathecal synthesis of proteins: from immunoglobulins to prealbumin.

The assessment of proteins intrathecal synthesis (ITS) is an essential step in the CSF analysis. It can be established qualitatively by different ratios and quantitatively by empirical formulae. Schuller and Sagar's formula was proposed 10 years ago for the calculation of IgG ITS. From this calculation, the antibody specific activity of intrathecal immunoglobulins may be also evaluated. The same principle may be used for complement components and for different other CSF proteins. Two examples (concerning Fibronectin and prealbumin ITS) demonstrate the usefulness of this approach, which can be programmed by a computer.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Clinical and virological aspects of HIV2 infection in rhesus monkeys.

To establish an animal model of AIDS, two different "wild" or "adapted" HIV2 Rod and Eho strains were cultivated on monkey cells from different species (baboons, cynomolgus, Rhesus monkeys). Five different available strains were then injected both by intravenous (i.v.) and intracerebral (i.c.) route into ten Rhesus monkeys. Seven animals seroconverted between days 13 and 230. Reverse transcriptase activity in the lymphocyte culture supernatants was detectable in six of the seven animals that seroconverted, and in one animal that remained seronegative. Lymphopenia and a decrease in the CD4+ cell counts were observed in eight animals. One animal, inoculated with HIV2-Rod "wild type," developed a severe cachexia, with dyspnea, and associated neurological symptoms 150 days after inoculation. This animal was sacrificed on day 220. Pathological examination showed typical lesions of actinomycetes infection in the lungs and in the meninges. Another monkey had significant weight loss associated with lymphadenopathies and pancytopenia. These results suggest that in vivo replication of HIV2 in Rhesus monkeys may induce clinical symptoms of immune deficiency. This method is reproducible and may provide a good model for AIDS.

Animals↗
PubMed1992

Alpha-interferon therapy in a case of probable progressive multifocal leukoencephalopathy.

Probable progressive multifocal leukoencephalopathy (PML) was diagnosed on the basis of clinical picture and magnetic resonance imaging in a 63-year-old man with a complete remission of a non-Hodgkin's lymphoma. After the introduction of intramuscular alpha-interferon therapy, his neurological state and MRI findings showed a clear improvement. Eighteen months after the onset of first symptoms the patient has significantly recovered from both aphasia and motor impairment, and shows only a mild attentional deficit.

Antineoplastic Combined Chemotherapy Protocols↗