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Biomedical subjects

P Loiseau

Publications and source records attributed to P Loiseau.

At least 55 records · Page 3Linked to original sources
PubMed1999

Review of controlled trials of gabitril (tiagabine): a clinician's viewpoint.

A recent problem for doctors has been the choice of which new antiepileptic drug (AED) to select for treatment of pharmacoresistant epilepsy. This article summarizes the clinical experience to date regarding the efficacy and safety of tiagabine (TGB; Gabitril) as adjunctive therapy in patients with partial-onset seizures. In its early Phase II development, TGB was evaluated in two multicenter pilot studies. Each had an open-label enrichment phase followed by a treatment phase with randomized, double-blind, two-period, cross-over phases. Between 24 and 50% of patients experienced reductions in seizure rates of > or =50%, depending on the type of partial seizure. In Phase III, three double-blind, parallel group, placebo-controlled adjunctive studies determined the efficacy of TGB in patients with refractory partial seizures. The first was a dose-response study employing doses of TGB-HCl of 16, 32 or 56 mg/day. Significant reductions in seizure rates were found with 32 and 56 mg/day. The second and third studies evaluated the efficacy of dosing TGB twice, three times, and four times daily, all of which showed similar efficacy. TGB efficacy in partial seizures was supported in several open trials, and no tolerance to efficacy was noted in long-term continuation studies. Tolerability was documented in all trials. Most adverse events were mild or moderate and transient, occurring during dose titration. They were clearly dose-related. No relevant changes in hematologic and biochemical tests, vital signs, or body weight were attributable to TGB. TGB appears to be an effective new drug for partial seizures with an acceptable safety profile.

Adolescent↗
PubMed1999

Prevalence of GBV C/HGV RNA and GBV C/HGV antibodies in French volunteer blood donors: results of a collaborative study.

BACKGROUND AND OBJECTIVES: Posttransfusion hepatitis still occurs at an incidence of about 1 in 118,000 for HBV and 1 in 220,000 for HCV. This collaborative study aimed to determine the prevalence of a novel flavivirus, GBV-C/HGV, even though its role in transfusion-associated hepatitis is uncertain. MATERIALS AND METHODS: GBV-C/HGV RNA was detected by PCR using either the Boehringer detection kit or by primers previously described. HGV antibodies were detected by a serological assay from Boehringer. RESULTS: The observed GBV-C/HGV RNA frequency was 3.4%. HGV antibodies occurred in 9.5% of donors. CONCLUSION: In our study, 12. 9% of the donors had been in contact with the GBV-C/HGV virus.

Adolescent↗
PubMed1999

Mycobacterium kansasii infection in a Paris suburb: comparison of disease presentation and outcome according to human immunodeficiency virus status. Groupe dEtude Des Mycobactéries de la Seine-Saint-Denis.

SETTING: Department of Seine-Saint-Denis, France. OBJECTIVE: To compare the presentation and outcome of Mycobacterium kansasii infections according to human immunodeficiency virus (HIV) status. DESIGN: Retrospective analysis of all the medical charts of adults meeting the diagnostic criteria of the American Thoracic Society for M. kansasii infection between 1991 and 1995. RESULTS: Between 1991 and 1995, 35 cases (23 HIV-[6%] and 12 HIV+ [34%]) were found, giving an annual incidence of 0.5/100000. The following particularities were common to both groups: 1) frequency and prominence of respiratory and general symptoms, 2) rarity of clinically apparent extra-thoracic involvement, 3) bacteriological confirmation mostly obtained with respiratory tract specimens, 4) favourable bacteriological outcome, and 5) low mortality attributable to the mycobacterial infection. The most striking differences concerned chest radiography: HIV- patients had apical cavitated and nodular lesions, while HIV+ patients exhibited a variety of other patterns, including alveolar infiltrates, miliary lesions and/or thoracic lymphadenopathy. CONCLUSION: Apart from pulmonary radiographic differences, presentation and short-term outcome of M. kansasii infections were similar in HIV+ and HIV-patients.

Adult↗
PubMed1999

[Epilepsies. Did you say 'epilepsy'?].

Epileptic disorders have been neglected for a long time by neurologists and practically ignored by pediatricians, satisfied with a diagnosis of infantile convulsions. Results of animal experimentation, huge progress in ancillary tests, potent antiepileptic drugs and efficacious neurosurgical procedures have considerably improved the condition of epileptic patients. However, much remains to be done. Even if numerous and varied, data given to physicians and patients are still insufficient. Stigma linked to the word epilepsy is present in many cases. It adds a supplementary burden to people who are not lacking in problems. Too often, epilepsy remains a word used in the singular, but epileptic seizure is not synonymous with epilepsy. The outcome and hence the consequences of epilepsies are quite various. A diagnosis of seizure may be difficult, and its classification not easy in all the cases. To place it in context, that is to find its causes and consequences is even more difficult. A good knowledge of epileptic disorders and efforts to use it are necessary, but one of them, or both, can be absent. This is unfortunate, because of the frequency and duration of conditions in which seizures are a symptom, and also because their outcome mostly depends on therapeutic choices. Only clinical, pragmatic aspects of the issue are considered here.

Cost of Illness↗
PubMed1998

Idiopathic generalized epilepsy of late onset.

Most idiopathic generalized epilepsies have an onset in childhood or adolescence, with a moderate second incidence peak in the presenium predominantly in women. This study addressed the question of a later onset. The available literature and the records of four personal data sets (two prospective incidence surveys of epileptic seizures, one prevalence study of epilepsy, and one clinical series of individuals with epilepsy) were screened for patients who had experienced a first generalized convulsive seizure with bilateral spike-wave complexes on EEG after 60 years of age. Reports of first idiopathic generalized tonic-clonic seizures occurring after age 60 were extremely rare and none was found in our four cohorts regardless of the methodology involved. Only five case reports were found, all involving a woman. Two had a family history of seizure disorders and two had had at least one seizure earlier in life. Idiopathic generalized epilepsy of late onset, if this condition actually exists, is likely to be the consequence of a genetic predisposition triggered by acquired epileptogenic factors.

Age of Onset↗
PubMed1998

Screening blood donations for viral genomes: multicenter study of real-time simulation using pooled samples on the model of hepatitis C virus RNA detection.

BACKGROUND: The systematic screening for several blood-borne viral genomes in blood donations is a complementary safety measure planned or discussed by the national authorities of several countries. STUDY DESIGN AND METHODS: To appreciate the feasibility of such screening using pooled samples, a multicenter study of real-time simulation has been performed on the model of hepatitis C virus (HCV) infection. Four blood transfusion center laboratories and two research and diagnosis laboratories simultaneously screened, by several HCV RNA polymerase chain reaction assays, a panel of plasma sample pools of different sizes (500, 100, and 10 samples), collected from HCV-infected or HCV-uninfected blood donors. One viremic plasma was introduced in each pool. HCV RNA was detected by in-house polymerase chain reaction procedures or by standardized manual or semi-automated polymerase chain reaction assays. RESULTS: The results indicate the feasibility of sample pooling, which renders the screening for viral genomes by molecular biology techniques applicable in the short term and the importance of the experience of laboratory personnel in the use of molecular biology tools. CONCLUSION: The improvement of standardized assays needs to be continued, and training of laboratory staff members appears to be a crucial step before systematic screening of blood donations for viral genomes by molecular biology techniques can occur.

Blood Donors↗
PubMed1998

Description of a new DRB1*11 allele (DRB1*1132).

We describe a new DRB1*11 allele which is similar to DRB1*11011 except at codon 74, where a GCG is changed for a GTG leading to an alanine/valine substitution. This new allele was carried by a Caucasian patient suffering from rheumatoid arthritis and by her healthy daughter. The motif at codon 74 of the new DRB1*11 is not found in any other known DRB alleles, nor among the published DQA1, DQB1, DPA1 or DPB1 alleles, and therefore suggests a mechanism of point mutation.

Alleles↗
PubMed1998

Treatment of concomitant illnesses in patients receiving anticonvulsants: drug interactions of clinical significance.

As epilepsy often is a chronic condition requiring prolonged therapy with anticonvulsants, patients being treated for epilepsy can be at risk when they are prescribed other drugs for concomitant diseases. Pharmacokinetic interactions can occur at each step of drug disposition (absorption, distribution, metabolism and elimination). Although such interactions may occur frequently with some drugs, only some will be clinically relevant. Alterations in the hepatic biotransformation of metabolised drugs due to hepatic isoenzyme induction or inhibition is of particular concern. The consequences of pharmacokinetic interactions are either accumulation of the drug leading to toxicity, or lowering of plasma concentrations resulting in reduced efficacy. Clinically relevant interactions depend on the structure, dosage and duration of administration of interacting agents, and on the individual's genetic make-up. In the past, drug interactions have been analysed empirically. At present, at least for interactions between drugs that are biotransformed in the liver, the risk should be predicted by considering the individual cytochrome P450 isoforms involved in the metabolism of coadministered drugs. Although drug-drug interactions can be predicted, their extent cannot be due to large interindividual variability. Even if nearly all drug combinations could be used with close clinical surveillance and blood concentration determinations, drugs that are not metabolised and are not highly protein bound, as are several of the new anticonvulsants, such as gabapentin, lamotrigine and vigabatrin, have a clear advantage in terms of a lower interaction potential.

Analgesics↗
PubMed1998

[Persistence of point-waves in the encephalogram (EEG) in idiopathic generalized epilepsy and therapeutic decisions].

We reviewed the literature on the following issues in idiopathic generalized epilepsy, is there a correlation between the persistence of seizures and electroencephalographic anomalies? Do point-waves observed in well-controlled patients constitute a factor predicting relapse? Do changes in paroxysmal anomalies during the disease course mean poor prognosis? Actually, there is very little literature on these issues and some disagreement in those data which have been published. Documented studies have been conducted in search of factors predicting relapse at treatment withdrawal, but little has been published concerning the role of the EEG. Few studies specifically mention idiopathic generalized epilepsy. In terms of the syndrome studied, they concern heterogeneous groups of patients. Generally, it is accepted that the EEG helps predict clinical course in idiopathic generalized epilepsy as it does in other epilepsies, given the characteristic EEG signs. This is true in patients under treatment and after treatment withdrawal. Risk errors were not however reported. II would appear reasonable to assume that no one EEG anomaly is determinant outside the clinical context.

Electroencephalography↗
PubMed1997

Natural history of GBV-C/hepatitis G virus infection through the follow-up of GBV-C/hepatitis G virus-infected blood donors and recipients studied by RNA polymerase chain reaction and anti-E2 serology.

The aims of this study were to determine the outcome and the natural history of GBV-C/hepatitis G virus (HGV) infection and to establish the frequency of acute or persistent infections in multiply-transfused individuals and blood donors. We used a GBV-C/HGV RNA polymerase chain reaction (PCR) and an assay evidencing antibodies to the envelop protein E2, which is considered a marker for virus clearance. Among 16 PCR-positive recipients, 11 were still positive for GBV-C/HGV RNA at the end of the study period; six of the 16 recipients were GBV-C/HGV infected during the study period and thus had a well-defined date of infection. The 16 patients were shown to carry GBV-C/HGV RNA over a mean period of 4.4 years, for a mean observational period (defined as the follow-up period since the first sample positive for GBV-C/HGV RNA) of 5.3 years. Within the limits of the study period, the patients with a well-defined date of infection were positive for GBV-C/HGV RNA during a mean period of 4.7 years. If defined by the presence of GBV-C/HGV RNA for at least 6 months, the persistent infection rate was 100% in this recipient cohort. Serum anti-E2 antibody was evidenced at least once in five (31.2%) recipients and, except in one case, became detectable after the loss of GBV-C/HGV RNA. Among the 11 blood donors, all were still positive for GBV-C/HGV RNA after a mean follow-up period of 7.7 months. The persistent infection rate was 100% in this donor cohort. Once acquired, the infection to GBV-C/HGV generally tends to persist in immunocompetent patients.

Adenovirus E2 Proteins↗
PubMed1997

Prevalence and clinical features of hepatitis G virus infection in bone marrow allograft recipients.

To study the prevalence and clinical features of hepatitis G virus (HGV)/GB virus C (GBV-C) infection in bone marrow transplantation (BMT), we examined frozen serum samples from 95 bone marrow allograft patients for HGV/GBV-C RNA by RT-PCR. Twenty-eight out of 95 (29.5%) were positive and 14 of the HGV+ patients were already positive before transplantation. The mean numbers of blood donors to whom the HGV and HGV+ populations were exposed before BMT were not significantly different (Kruskal-Wallis test, P = 0.08, NS) but did reveal that the HGV+ population had been transfused more often. Moreover, all but one of the patients who were HGV+ before graft, had had hematological diseases which needed heavy transfusion protocols suggesting, a role of blood products in HGV transmission. Fifty out of the 95 patients received Gammagard intravenous immunoglobulin (i.v.IG) batches suspected of having transmitted HCV. However, no significant difference appeared between these recipients and those receiving other i.v.IG. Despite their immunodeficiency, no clinical or biological evidence of liver disease potentially linked to HGV infection has as yet been observed. The clinical outcome, in terms of acute GVHD, chronic GVHD or veno-occlusive disease was similar in HGV+ and HGV- recipients suggesting the absence of adverse effects of HGV infection on the early outcome of allogenic BMT. Long-term evolution remains to be prospectively studied.

Adolescent↗
PubMed1997

Prevalence of hepatitis G virus RNA in French blood donors and recipients.

BACKGROUND: Recently, cases of chronic hepatitis were linked to the presence of genomic sequences of a newly described RNA virus termed hepatitis G virus (HGV) and belonging to the Flaviviridae family. STUDY DESIGN AND METHODS: The presence of HGV RNA was searched for by polymerase chain reaction in a population of blood donors and in patients who had received multiple blood component transfusions and/or intravenous immunoglobulin (IVIG) infusions. RESULTS: Twenty-one (4.2%) of 500 donors were positive for HGV RNA as were 21 (10.7%) of 196 nonimmunosuppressed patients who had received multiple transfusions of packed red cells, 4 (8.7%) of 46 common variable immune deficiency (CVID) patients who had received only IVIG, and 22 (24.7%) of 89 bone marrow transplant (BMT) patients who had received IVIG and cellular components. The proportion of HGV-positive individuals was significantly higher in the immunosuppressed recipients (CVID and BMT patients) than in the nonimmunosuppressed patients who were multiply transfused with packed red cells (p < 0.03). The proportion of HGV-positive individuals was significantly higher in the BMT patients who had received IVIG and cellular components than in the CVID patients who had received IVIG only (p < 0.03). Eight (17.0%) of the 47 HGV-positive recipients and 48 (16.9%) of the 284 HGV-negative recipients had a serum alanine aminotransferase level higher than the upper limit of normal (nonsignificant difference). The medical history of HGV-positive donors failed to reveal a particular at-risk event. The large majority of HGV-infected patients had a normal serum alanine aminotransferase level, and the proportion of patients with elevated alanine aminotransferase was the same in HGV-positive and in HGV-negative recipients. CONCLUSION: The pathological significance of HGV infection remains unelucidated, and the classification of HGV as a new hepatitis virus was perhaps premature.

Adult↗