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B Laurent

Publications and source records attributed to B Laurent.

At least 19 recordsLinked to original sources
PubMed2007

TNFA2 and d2 alleles of the tumor necrosis factor alpha gene polymorphism are associated with onset/occurrence of idiopathic membranous nephropathy.

Idiopathic membranous nephropathy (IMN) has a strong association with the major histocompatibility complex HLA B8DR3(17)DQ2 haplotype. The tumor necrosis factor (TNF)A gene is located within the major histocompatibility complex region on chromosome 6. We have studied the influence of two functional polymorphisms; the -308 (promoter region) and the TNFd microsatellites on initiation and/or progression of IMN. This was a case-control study comparing data from 100 Caucasians patients (67 male subjects; 67%) with IMN to 232 Caucasians local controls (171 male subjects; 74%). We have analyzed genotypes and alleles distributions and the role of these polymorphisms in disease progression towards end-stage renal failure or patient death. For -308 TNFA polymorphism, distribution of genotypes was significantly different between IMN and controls (chi(2)=16.25; P=0.0003): the A2 allele frequency was 28.0% in IMN vs 15.3% in controls (chi(2)=14.57; P=0.0001). For TNFd polymorphism, alleles distribution (from d1 to d7) was also significantly different between IMN and controls (chi(2)=56.74; P<0.0001) with both diminished d3 allele frequency (chi(2)=27.30; P<0.0001; Pc=0.001) and increased d2 allele frequency (chi(2)=29.95; P<0.0001; Pc=0.001) in IMN. We could not isolate any significant and independent influence of these different genotypes on IMN disease progression. The TNFA2 and TNFd2 alleles were strongly associated with occurrence/initiation of IMN and should be considered as susceptibility genes for this disease.

Adult↗
PubMed2006

Alpha:2n:alpha molecular band in 10Be.

The 10.15 MeV resonance in 10Be has been probed via resonant 6He+4He elastic scattering. It is demonstrated that it is the Jpi=4+ member of a rotational band built on the 6.18 MeV 0+ state. A Gammaalpha of 0.10-0.13 MeV and Gammaalpha/Gamma=0.35-0.46 were deduced. The corresponding reduced alpha width, gamma2alpha, indicates one of the largest alpha-cluster spectroscopic factors known. The deformation of the band, including the 7.54 MeV, 2+ member, is large (h2/2I=200 keV). Such a deformation and the significant degree of clusterization signals a well-developed alpha:2n:alpha molecular structure.

Journal Article↗
PubMed2006

[Neuropsychological markers for the diagnosis of Alzheimer's disease].

Better knowledge of the preclinical phase of Alzheimer's disease and of the symptomatic pre-dementia stage designated "mild cognitive impairment" will require considerable progress in our understanding of neuropsychological processes. The results of studies suggest that impaired performance in memory tests may serve as a marker for Alzheimer's disease. The best current predictors include stringent tests of episodic memory and recognition tests. The early stages of Alzheimer's disease also seem to involve subtle deficits in semantic memory and attentional processes. Face recognition and denomination seem to be useful tools. Greater accuracy and precision in the transitional zone between healthy aging and the first manifestations of Alzheimer's disease will require work combining data on neuropsychological profiles and neuroimaging.

Aged↗
PubMed2006

[Evaluation of memory for French public events: EVE-30 in 108 controls, 10 mild cognitively impaired and 10 Alzheimer's disease patients].

INTRODUCTION: Public events memory is a principal historic component of memory for the past. METHOD: We propose a new form of the French public events battery EVE which has been elaborated in 1994. EVE-30 uses 30 events dated between 1920 and 2004. Each event assesses recall, recognition, questions and dating. New exposure and flash souvenirs can be explored. One hundred and eight controls aged between 20 and 79 years, ten patients with Alzheimer's disease (AD) and ten patients with amnesic mild cognitive impairment (aMCI) were evaluated. RESULTS: Mean percentage of good responses in controls group is good with a scale of 72p.cent. Performances were gradually observed. Recognition was respectively better than recall, than datation and than questions. Statistical analysis with ANOVA showed that an older age and a higher level of education significantly influenced results (p<0.05). MCI patients and MA patients exhibited more impaired performances than controls. MCI and MA patients had similar impairment in recognition and questions (very altered in the two groups). The French public events battery (EVE 30) can be performed in one hour and may be considered as a neuropsychological tool for the evaluation of memory for the historical past in clinical practice.

Adult↗
PubMed2005

[Primary and atypical facial pain: diagnosis and treatment].

PURPOSE: Facial pain is a frequently encountered symptom in general medical practice and encompass a wide group of facial problems. As correct diagnosis can usually be reached by history and physical examination for well defined typical clinical entities (trigeminal neuralgia, cluster headache) atypical facial pain may have many other potential causes (sinuses infection, temporomandibular joint syndrome, dental disorders...) so that diagnosis not appear an easy task. CURRENT KNOWLEDGE AND KEYPOINTS: Anatomical and physiological organization of facial nociceptive system, particularly trigeminal system, may explain the variability of facial pain. Although symptoms have been clearly identified mechanism of pain production remains controversial. Several factors (psychological, neurological, endocrine...) and mechanisms (neuropathic, vascular, myoarticular) may coexist and explain trouble in diagnosing and treating facial pain. FUTURE PROSPECTS AND PROJECTS: Better knowledge in identifying the cause of facial pain may lead to improve patient care and avoid patient frustration, medical nomadism, repetitive dental and otolaryngologic procedures, and finally non-compliance with treatment.

Facial Nerve Diseases↗
PubMed2004

An fMRI study of cortical representation of mechanical allodynia in patients with neuropathic pain.

OBJECTIVE: To investigate cerebral activity associated with allodynia in patients with neuropathic pain. METHODS: The brain responses of 27 patients with peripheral (5), spinal (3), brainstem (4), thalamic (5), lenticular (5), or cortical (5) lesions were studied with fMRI as innocuous mechanical stimuli were addressed to either the allodynic territory or the homologous contralateral region. RESULTS: When applied to the normal side, brush and cold rubbing stimuli did not evoke pain and activated a somatosensory "control" network including contralateral primary (SI) and secondary (SII) somatosensory cortices and insular regions. The same stimuli became severely painful when applied to the allodynic side and activated regions in the contralateral hemisphere that mirrored the "control" network, with, however, lesser activation of the SII and insular cortices. Increased activation volumes were found in contralateral SI and primary motor cortex (MI). Whereas ipsilateral responses appeared very small and restricted after control stimuli, they represented the most salient effect of allodynia and were observed mainly in the ipsilateral parietal operculum (SII), SI, and insula. Allodynic stimuli also recruited additional responses in motor/premotor areas (MI, supplementary motor area), in regions involved in spatial attention (posterior parietal cortices), and in regions linking attention and motor control (mid-anterior cingulate cortex). CONCLUSION: On a background of deafferentation in the hemisphere contralateral to stimuli, enhanced or additional responses to innocuous stimuli in the ipsilateral hemisphere may contribute to the shift of perception from innocuous toward painful and ill-defined sensations.

Basal Ganglia↗
PubMed2004

[Morbidity after stapled haemorrhoidectomy: long-term results about 140 patients and review of the literature].

AIM: The aim of this study was to determine the results and the complications of the treatment of hemorrhoids with circular stapler with a follow-up of 18 months, and to review the complications in the literature. METHODS: From April 1998 to August 1999, 140 patients (83 males and 57 females) with an average age of 43.8 years (range: 19-83 years) underwent haemorrhoidectomy using a circular stapler in three university hospital centers. The degree of hemorrhoids has been classified: three cases of degree II, 97 cases of degree III, and 40 cases of degree IV. All the patients were prospectively evaluated at two weeks, two and 18 months after surgery. RESULTS: The average length of the operation was 18 minutes (range: 8-60 minutes). Mean hospital stay was 36 hours (range: 8-72 hours). There was no intraoperative complication. There was no mortality. The postoperative complication rate was 7.8% (N = 11): there were five cases of bleeding that two complicated by a submucosal hematoma (one was infected and needed a rectotomy on day 21), two cases of urinary retention, and two cases of external hemorrhoid thrombosis. The bleeding occurred in the 12 hours after surgery except for one patient with antivitamin K whith presented a secondary bleeding on day 16. At 18 months, five patients presented a moderate asymptomatic stricture dilated on digital examination. Two patients complained of persistent skin tags. Neither functional trouble nor incontinence to gas, liquids, or solids was presented. With a mean follow-up of 40 months, 90% (N = 112) of the patients were fully satisfied. CONCLUSIONS: Treatment of hemorrhoids with circular stapler appears to be effective with 96% of patients fully satisfied at 18 months. The morbidity rate was low, and no higher than the diathermy excision hemorrhoidectomy. The results are directly dependent on the practice that required a learning, and not on the technique itself.

Adult↗
PubMed2003

Subacute meningoencephalitis in a subset of patients with AD after Abeta42 immunization.

BACKGROUND: AD is characterized by cerebral deposition of beta-amyloid plaques with amyloid beta-peptide (Abeta) 42 as the major peptide constituent, along with neurofibrillary tangles and neuronal loss. In transgenic mice, active immunization against Abeta42 removes these plaques and improves cognitive function. A Phase I study in AD patients demonstrated good safety and tolerability of multiple injections of aggregated Abeta42 (AN1792) with QS-21 as adjuvant. METHODS: Three hundred seventy-two patients with mild to moderate AD were randomized to receive IM injections of AN1792 or placebo (4:1) at baseline and at months 1, 3, 6, 9, and 12 in a multicenter Phase II safety, tolerability, and pilot efficacy study. Dosing was terminated after four early reports of meningoencephalitis, but follow-up continued. The study remains blinded, and further results will be reported after its termination. RESULTS: Symptoms and laboratory findings consistent with meningoencephalitis occurred in 18 of 298 (6%) patients treated with AN1792 compared with 0 of 74 on placebo (p = 0.020). Sixteen of the 18 had received two doses, one had received one dose, and one had received three doses of the study drug before symptoms occurred. The median latency from the first and last injections to symptoms was 75 and 40 days. No case occurred later than 6 months after the first immunization. Anti-Abeta42 antibody titers were not correlated with the occurrence or severity of symptoms or relapses. Twelve patients recovered to or close to baseline within weeks, whereas six remain with disabling cognitive or neurologic sequelae. All 18 patients remain alive to date (December 31, 2002), 6 months to >1 year after symptom onset. CONCLUSIONS: Postvaccination meningoencephalitis occurred without clear relation to serum anti-Abeta42 antibody titers. Potential mechanisms such as T-cell and microglial activation may be responsible and are under consideration to develop a safer anti-Abeta immunotherapy for AD.

Adrenal Cortex Hormones↗
PubMed2002

Role of operculoinsular cortices in human pain processing: converging evidence from PET, fMRI, dipole modeling, and intracerebral recordings of evoked potentials.

Insular and SII cortices have been consistently shown by PET, fMRI, EPs, and MEG techniques to be activated bilaterally by a nociceptive stimulation. The aim of the present study was to refer to, and to compare within a common stereotactic space, the nociceptive responses obtained in humans by (i) PET, (ii) fMRI, (iii) dipole modeling of scalp LEPs, and (iv) intracerebral recordings of LEPs. PET, fMRI, and scalp LEPs were obtained from normal subjects during thermal pain. Operculoinsular LEPs were obtained from 13 patients using deep brain electrodes implanted for presurgical evaluation of drug-resistant epilepsy. Whatever the technique, we obtained responses which were located bilaterally in the insular and SII cortices. In electrophysiological responses (LEPs) the SII insular contribution peaked between 150 and 250 ms poststimulus and corresponded to the earliest portions of the whole cerebral response. Group analysis of PET and fMRI data showed highly consistent responses contralateral to stimulation. On single-subject analysis, LEPs and fMRI activations were concentrated in relatively restricted volumes even though spatial sampling was quite different for both techniques. Despite our multimodal approach, however, it was not possible to separate insular from SII activities. Individual variations in the anatomy and function of SII and insular cortices may explain this limitation. This multimodal study provides, however, cross-validated spatial and temporal information on the pain-related processes occurring in the operculoinsular region, which thus appears as a major site for the early cortical pain encoding in the human brain.

Adult↗
PubMed2002

Cognitive effects of precentral cortical stimulation for pain control: an ERP study.

Electrical stimulation of the motor cortex (MCS) is a promising and increasingly used neurosurgical technique for the control of refractory neuropathic pain. Although its mechanisms of action remain unknown, recent functional imaging data suggest involvement of the thalamus, brainstem and anterior cingulate/orbitofrontal cortex. Since some of these areas are also implicated in higher cognitive functions, notably attentional processes, we analysed cognitive ERPs and behavioural performance during an "oddball" auditory detection task in patients submitted to this procedure. Eleven consecutive patients undergoing MCS because of neuropathic refractory pain, ranging in age from 25 to 71 years, were included in the study. ERPs were obtained in all cases both during the application ("MCS-on") and within the 10 min that followed discontinuation of the procedure ("MCS-off"). In five patients, ERPs could also be obtained just before the start of MCS. When the patients' sample was taken as a whole, there were no consistent effects of MCS on the ERPs. There was, however, a significant interaction of MCS action with the patients' age, reflecting a significant delay during MCS of the cognitive responses N2 and P3 (N200 and P300) in the group of patients older than 50 years exclusively. This effect was rapidly reversible after MCS discontinuation. No MCS-related changes were observed in the N1 component. At the individual level, the effect of MCS on the endogenous ERPs was highly variable, ranging from a total stability of ERPs (mostly in younger subjects) to latency differences of tens of milliseconds in the older group. These results, together with recent experiments showing P300 alteration during repetitive transcranial stimulation, suggest that motor cortex stimulation may interfere with relatively simple cognitive processes such as those underlying target detection, and that the risk of abnormal cognitive effects related to cortical stimulation may increase with age. Although the procedure appears on the whole remarkably safe, complementary neuropsychological studies in this category of patients are advised, as well as caution to possible adverse cognitive effects when using MCS in the elderly, notably in the presence of pre-existent cerebral lesions.

Adult↗
PubMed2002

Serum pentosidine as an indicator of Alzheimer's disease.

Pentosidine, an advanced glycation end product (AGE), was assayed by HPLC in serum proteins from patients with Alzheimer type dementia (AD), patients with diabetes mellitus (D), and healthy (C) age-matched old subjects (mean age from each group = 84 years). Serum pentosidine was significantly different between the three groups despite similar renal function (serum creatinine < 160 micromol/L). In all groups of patients, pentosidine was independent of glycated hemoglobin (HbA1C) and the early glycation marker fructosamine and appeared to be an independent marker, mainly bound to serum albumin. Pentosidine could be an important factor useful for the diagnosis of Alzheimer's disease.

Aged↗
PubMed2002

[Alzheimer's disease: a public health problem: yes, but a priority?].

Alzheimer's Disease is a major Public Health problem for many reasons. First, it is a frequent disease since, in France, the prevalence was estimated at about 400.000 cases, and the annual incidence at 100.000 cases. The frequency of the disease increases, in particular due to the ageing of the population. This disease has major consequences on the life of the patient and his/her caretaker. The cost of the disease is important, estimated at about 50 milliards of French francs. Pharmaceutical treatment and other interventions are possible in particular to delay the nursing home placement. On the other hand, this disease is often ignored, under-diagnosed, underestimated and exposed to inequality in resorting to care. In summary, Alzheimer's Disease (AD) has all the criteria required for a major public health problem. In spite of this observation, AD is not yet considered as a priority for health authorities, although attitudes are changing.

Accidents, Traffic↗
PubMed2002

[First epileptic seizure in the elderly: electroclinical and etiological data in 341 patients].

This study included 341 subjects aged over 60 years, 174 females and 167 males, (mean age 72-years), who experienced their first epileptic seizure and fulfilled all inclusion criteria over an 8-year period. Data were available from the physical examination, EEG, laboratory tests and CT scan or MRI for all patients. The international classification of epileptic seizures was applied, 41 p.cent of the seizures were generalized and 59 p.cent were partial. Status epilepticus occurred in 8 p.cent of the patients. The EEG recording was contributive to diagnosis or helpful for localizing the epileptic focus in 55 p.cent of the patients. Normal brain imaging was observed in 40 p.cent of the patients. The main etiology was cerebrovascular disease (33 p.cent), acute stroke (27 patients), or more often postvascular epilepsy (87 patients). Other etiologies were degenerative cortical dementia in 7 p.cent of the patients, metabolic and toxic disorders in 11 p.cent, and benign or malignant brain tumors in 6.5 p.cent. Thirty-two percent of the seizures were of unknown origin (cryptogenic seizures). No correlation was found between sex, age, and etiology. An antiepileptic drug treatment was initiated in 77 p.cent of the patients who were given either valproate (43 p.cent), carbamazepine (26 p.cent) or barbiturates (7 p.cent). These findings are in agreement with those reported in the reviewed literature.

Aged↗
PubMed2002

[Validation of the combined SF36/MSQOL test of evaluation of quality of life in migraine patients in France].

The impact of migraine on patients quality of life is great, even between attacks. The aim of this study was to assess the properties of a French language quality of life questionnaire, which associates the Medical Outcome Study Short Form (MOS SF 36) with the Migraine-Specific Quality of Life (MSQOL). Data were obtained from 110 consultant patients of neurology units located in three University hospitals in the center of France. The results indicated a good acceptability of the association of the two questionnaires with a 84p.cent response rate. The Principal Component Analysis showed no change in both SF-36 and MSQOL structures. It also suggested that the two questionnaires were complementary. The high values of the Cronbach alpha coefficients for each scale indicated a high level of internal consistency. The quality of life scores were correlated with external parameters such as frequency, intensity and length of migraine attacks, and social activity reduction due to these attacks. In conclusion, the association of the SF-36 with the MSQOL has the interest of associating generic and specific questionnaire, in a complementary way. This association has good psychometric properties, and can be used to evaluate migraineurs quality of life in French speaking countries.

Adult↗
PubMed2002

[Limits and uncertainties about the concept of MCI: contribution of neuropsychological approach].

The diagnosis of Alzheimer disease is earlier with the memory clinics at a stage preceding the DSMIV criterions of dementia when the complaints are only in the field of memory without daylife impairment (stage CDR 0,5 at the Morris clinical dementia rating). This "predemential" stage is obviously more uncertain in terms of diagnosis and prognosis than the later one but some groups declare the same reliability with combining neuropsychology, biological markers in CSF and imagery. The MCI as a pure syndromic definition but the prospective studies have demonstrated that only 20 to 30p. cent of MCI will remain steady after 5 years of following, and several autopsies of MCI have showed that the neuropathological frontier of Alzheimer disease were crossed with neurofibrillary tangles and senile plaques in the hippocampus. Many trials have been conducted in the different fields of neuropsychology, biological markers and imagery to distinguish the MCI "decliners" from the MCI not related to Alzheimer. In that paper we will analyze all the clinical and neuropsychological perspectives to make that distinction with the maximum of reliability. The question of the usefulness of the MCI concept remains open, taking into account the progress in the very early stage diagnosis of Alzheimer's disease.

Aged↗
PubMed2001

[Quality of life of lumbago patients cared for in a pain center].

OBJECTIVE: To evaluate the quality of life of patients treated in a pain center. METHOD: Sixty eight patients were assessed during their first consultation, then 6, 12 and 18 months later, using a quality of life questionnaire "SQVP or Subjective Quality of Life Profile" validated in French populations and a panel of questionnaires for the monitoring of chronic pain, recommended by the ANAES (French Agency for Health Assessment). RESULTS: Results showed that: the patients' quality of life was clearly deteriorated (lowest quality in the data base--14,000 patients--with regard to the SQVP); the profile obtained (severe handicap) suggests that the lumbagos are part of a psychiatric context; the patients' quality of life clearly improves after 6 months' treatment, but the pain only stabilizes later.

Adult↗