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Biomedical subjects

P Lebon

Publications and source records attributed to P Lebon.

At least 145 records · Page 8Linked to original sources
PubMed1985

Human epidermal cells are more potent than peripheral blood mononuclear cells for the detection of weak allogeneic or virus-specific primary responses in vitro.

Human epidermal cells (EC) and peripheral blood mononuclear cells (PBMC) have been used as antigen-presenting cells in allogeneic reactions or in self-restricted antiviral responses. Comparison of results from both cell types indicates that: (1) EC were better stimulators of primary proliferative responses in all the antigenic systems tested. (2) In secondary reactions, EC and PBMC functioned similarly for allogeneic responses, while a weak but significant difference could be observed in both (HSV1 or influenza A) virus-specific reactions. (3) By comparing pairs of HLA-identical mixed lymphocyte reaction (MLR)-negative siblings, positive responses were observed in several different families when lymphocytes of potential bone marrow donors were stimulated by EC of the recipient. This suggests that EC might be useful in detecting relatively weak proliferative responses in a number of antigenic systems, but especially in primary reactions against viral or putative minor histocompatibility antigens. (4) Despite this stronger antigen-presenting capacity in proliferative responses, EC induced lower levels of cytotoxic T lymphocyte (CTL) reactions than PBMC, not only in allogeneic responses but also in virus-specific self-restricted reactions.

Adult↗
PubMed1985

Inhibition of herpes simplex virus type 1-induced interferon synthesis by monoclonal antibodies against viral glycoprotein D and by lysosomotropic drugs.

Components of herpes simplex virus remained bound to the diploid cell membrane after nucleocapsid penetration into the cytosol. These components enabled the infected cells to induce interferon-alpha (IFN-alpha) in peripheral blood mononuclear cells even when the infected cells were fixed by glutaraldehyde. Monoclonal antibodies directed against the major viral glycoprotein D could neutralize their IFN-alpha-inducing capacity. Thus, the process of IFN induction does not require uptake and penetration of the inducer into the effector cells. The process was, however, sensitive to lysosomotropic drugs. These data suggest that a membrane receptor is involved in the IFN-alpha induction mechanism.

Ammonium Chloride↗
PubMed1985

Intrathecal synthesis of different alpha-interferons in patients with various neurological diseases.

CSF and sera from 238 newborns and children with various neurological diseases were assayed on bovine cells for the presence of alpha-interferon (IFN). An intrathecal synthesis of pH 2-resistant alpha-IFN was recovered in all newborns and in more than 90% of children with herpes encephalitis. It was also observed in one case of mumps encephalitis and in one case of encephalitis associated with Influenza A infection. An acid-labile alpha-IFN production was detected in CSF from more than one half of patients with viral meningitis or active congenital rubella and in those with neurological complications of systemic lupus erythematosus. This alpha-IFN subtype was also detected in CSF from only 2/37 children with measles encephalitis. In contrast, no alpha-IFN (less than 2 IU) in CSF was found among patients with subacute sclerosing panencephalitis, Guillain-Barré syndrome, Reye's syndrome, acute cerebellar ataxia, infantile spasms or facial paralysis of unknown origin.

Acute Disease↗
PubMed1985

Presence of an acid-labile alpha-interferon in sera from fetuses and children with congenital rubella.

In congenital rubella an acid-labile alpha-interferon was present in sera collected from fetuses between weeks 21 and 29 of gestation and from children with active congenital rubella. This interferon was different from the interferon detected in normal amniotic fluid and was not found in sera from uninfected fetuses or from children with postnatally acquired rubella. The fetal interferon is of interest as a complementary marker to confirm the virus contamination of the fetuses during maternal rubella. The role of the prolonged synthesis of this interferon in congenital rubella disease and its immune defects are discussed.

Adolescent↗
PubMed1984

Prenatal diagnosis of congenital rubella.

In an attempt at prenatal diagnosis of fetal infection after primary rubella infection before 18 weeks of pregnancy fetal blood was taken by direct puncture under ultrasound guidance at 20-26 weeks of pregnancy from eighteen patients. Total IgM was assayed by radial immunodiffusion and rubella-specific IgM by IgM capture immunoassay. Rubella-specific IgM was detected in twelve of the eighteen fetuses. The parents decided whether to continue or terminate the pregnancy on the basis of the time of onset of maternal rubella. All six pregnancies in which rubella occurred before 12 weeks of gestation were terminated. Of the six with rubella after 12 weeks two were terminated. Among the six fetuses negative for rubella-specific IgM, five had no rubella-specific IgM at birth and no persistent IgG but one was found to be infected at birth; this false-negative diagnosis was due to sampling too early during pregnancy.

Antibody Specificity↗
PubMed1984

[Acute encephalitis in zoster infection].

A case of herpes zoster acute meningo-encephalitis is reported. It is characterized by a profuse intra-cerebral hemorrhage on CT scan and a favorable outcome after treatment with acyclovir. The serological basis for the diagnosis, the mechanism of the encephalitis (viral invasion or immuno-allergic type of reaction), and the origin of the hemorrhagic lesion are discussed. The effectiveness of acyclovir in treating the extention of the infection to the nervous system in patients suffering from varicella-zoster is also discussed.

Acyclovir↗
PubMed1984

Intestinal lesions containing coronavirus-like particles in neonatal necrotizing enterocolitis: an ultrastructural analysis.

Since the outbreaks of neonatal necrotizing enterocolitis occurring in maternity hospitals of Paris and suburbs in 1979-1980, it has been possible to examine by light and electron microscopy gut specimens from ten newborns with this illness. Coronavirus-like particles, enclosed in intracytoplasmic vesicles of damaged epithelial cells of the intestinal mucosa, were observed in the small intestine, appendix, and colon. The ultrastructural study, supported by bacteriologic findings, suggests the role of coronavirus-like particles in the appearance of the lesions. Secondary proliferation of mainly anaerobic bacteria, probably responsible for pneumatosis, may aggravate the disease.

Appendix↗
PubMed1983

[Dogmatil and vertigo in the aged subject. Apropos of 10 years' prescribing].

Dogmatil, whose effectiveness on vertigo resulting from peripheral causes is well-documented, is just as potent in central vestibular disorders. In elderly patients, the most common etiology of vertigo is a combination of varying degrees of vertebrobasilar insufficiency, arteriosclerosis and arthrosis of the cervical spine. Patients usually present with a permanent feeling of unsteadiness and anxiety, while electronystagmographic changes are usually of little significance. In most instances, Dogmatil is prescribed in a daily dose of 150 to 200 mg for 4 to 6 weeks, usually in the form of capsules. Three or four days are usually needed for the effect of Dogmatil to become apparent. However, in a non-negligible number of cases, the clinical effect of Dogmatil is clearly noticeable by the patient himself after 48 hours. Dogmatil is remarkably well-tolerated by the elderly, whether it is given as the sole medication or associated with other drugs which cannot be discontinued, such as those prescribed for cardiovascular or respiratory disorders.

Aged↗
PubMed1983

Synthesis of intrathecal interferon in systemic lupus erythematosus with neurological complications.

Intrathecal synthesis of interferon in the absence of viral or bacterial infection was detected during the occurrence of neurological complications in two patients with systemic lupus erythematosus. The interferons displayed characteristics similar to those observed in the sera of patients with the disease. No interferon inducing activity was detected in the cerebrospinal fluid or serum of the two patients. These observations support the hypothesis of a localised mechanism of interferon induction in systemic lupus erythematosus which includes the interaction of lymphocytes with damaged tissues.

Adolescent↗
PubMed1983

[Herpetic encephalitis in infants and children. Methods of diagnosis].

Thirteen infants and 2 children with Herpes simplex encephalitis are reported and the authors emphasize the diagnostic value of several investigations: the neurological examination (fits followed by early motor deficit on the same side and coma), the EEG (periodicity and asymmetry of the trace), the CT scan (hypodensity in the frontotemporal areas), the level of the Interferon alpha in blood and cerebrospinal fluid, the electrophoretic pattern of cerebrospinal fluid proteins and the comparative study of cerebrospinal fluid/serum antibodies towards several viral antigens.

Adolescent↗
PubMed1982

[Identification of lymphocyte populations producing alpha-interferon by monoclonal antibodies].

Two different leucocyte populations producing alpha-interferon can be defined by monoclonal antibodies. One non glass adherent population produces interferon after induction with Herpes and Sendaï viruses. It is characterized by anti-D44 antibody, defining both some T and NK cells, but not by anti-D66 antibody with selective reactivity for T cells. The other glass adherent population is identified by OKM1 antibody, which defines about 70% of the monocytes, and can be induced only with Sendaï virus.

Antibodies, Monoclonal↗
PubMed1982

The presence of alpha-interferon in human amniotic fluid.

Almost all the samples of amniotic fluid from 62 pregnant women from the 16th week to the end of the pregnancy contained detectable amounts of alpha-type interferon. The presence of this substance in amniotic fluid during pregnancy raises the question of the physiological significance of this finding. It is postulated that the amniotic type of alpha-interferon might be a product of a constitutive gene, rather than induced by latent virus infection.

Amniotic Fluid↗
PubMed1982

Association of coronavirus infection with neonatal necrotizing enterocolitis.

From the clustered occurrence of numerous cases of necrotizing enterocolitis in newborns, it was possible to associate this disease significantly with infection due to coronavirus-like agents. Prematurity or low birth weight did not seem to affect the development of the disease, at least during the present epidemic. However, associated gas-producing bacteria could influence its severity and play a role in the appearance of pneumatosis. In many aspects the human disease is reminiscent of experimental necrotizing enterocolitis obtained by infection of germ-free newborn animals, as reported in the literature.

Antibodies, Viral↗
PubMed1982

[Osteomalacia as a result of aluminum poisoning during chronic hemodialysis].

The iliac crest biopsy of an uremic child, suffering from nephronophtisis, and hemodialyzed since the age of 11 1/2 years, was examined by histomorphometry, electron-probe X-ray microanalysis and ion microscopy. The results have been compared with those obtained with the same techniques in the bone tissue of 11 hemodialyzed aluminum-intoxicated adults. In this child, radiology of the skeleton and plasma biochemistry suggested secondary hyperparathyroidism; by contrast, histology showed impaired mineralization, little bone resorption, and aluminum deposits at the limit between osteoid and calcified tissue similar to those observed in the bone tissue of the adults. This observation, and the fact that the child had a high plasma aluminum level, and that dialysis was performed with softened aluminum-rich water, strongly suggests that the severe osteomalacia of this child was due to aluminum toxicity.

Adolescent↗
PubMed1982

Bullous dermatosis associated with dysglobulinemia (two cases). Relationships with epidermolysis bullosa acquisita.

Two cases of bullous dermatosis with dysglobulinemia are described. The first one was associated with renal and neuromuscular amyloidosis and production of a monoclonal lambda IgG. Optical and electron microscopy showed amyloid deposits beneath basal lamina of the dermis. Results for direct and indirect immunofluorescence (IF) were negative. This bullous dermatosis is not an epidermolysis bullosa acquisita (EBA), in the strict sense, because the amorphous material deposited is amyloid. In the second case, associated with Waldenström's disease, there was no cutaneous or systemic amyloidosis. Direct IF was positive; linear IgM deposits were seen along the basal membrane of the bulla and the healthy skin. Indirect IF showed the presence of circulating antibodies against basal membrane zone. This bullous dermatosis is probably an EBA, despite the absence of IgG deposits. The absence of electron microscopy does not permit the confirmation of this diagnosis.

Aged↗