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Biomedical subjects

H Blain

Publications and source records attributed to H Blain.

At least 37 records · Page 2Linked to original sources

[Alzheimer disease. Epidemiology, genetics and physiopathological hypotheses].

RISK FACTORS: Aging is the chief risk factor for Alzheimer's disease (AD). Other risk factors are aluminum in drinking water, diabetes mellitus, head trauma. Protective factors are: higher education, cigarette smoking, nonsteroidal anti-inflammatory drugs and estrogen use. GENETIC FACTORS: Mutations of presenilins 1 and 2 and of the APP gene in families with early-onset AD. Apolipoprotein E polymorphism in late-onset familial and sporadic AD. PATHOGENIC HYPOTHESES: Amyloid deposits in senile plaques and therefore dementia could be due to an overproduction of Abeta (Down's syndrome) or due to the primary (APP mutation) or secondary (role of diabetes, mellitus, apoE polymorphism: protective effect of estrogen) abnormal neurotoxic feature of Abeta. The hyperphosphorylation of tau (a protein which plays a pivotal role in the axonal transport), perhaps regulated by the apoE polymorphism could lead to neurofibrillar degeneration. Neurotoxic mediators produced by the activated microglia (perhaps activated by neuronal damage) and oxidative stress could also be involved in the neurodegeneration.

Age Factors↗

[Alzheimer disease, markers in the cerebrospinal fluid. Support of physiopathologic hypotheses].

CERTAIN DIAGNOSIS: Because the certainty diagnosis of Alzheimer's disease is defined after autopsy or brain biopsy by the presence of neurofibrillar degeneration (NFD), extracellular senile plaques and vascular deposits of amyloid in the hippocampus amygdalus and the cerebral cortex, some authors have searched for biological ante-mortem markers of AD, particularly in the cerebrospinal fluid (CSF) which is essentially derived from brain tissue. SEARCH FOR MARKERS: Studies have investigated the CSF level of neurotransmitters, neuropeptides, amino acids, trace elements, constituents of NFD and senile plaques in a diagnostic and pathogenic perspective. HOPE FOR DIAGNOSIS: Even though ethical, technical and methodological difficulties met by authors are important and even though many clinical and biological parameters must be taken into account, these studies bring important pathogenic evidence and allow hope that markers of AD which are so necessary for early diagnosis and objective study of therapies will be found.

Alzheimer Disease↗

Abnormal substrate levels that depend upon mitochondrial function in cerebrospinal fluid from Alzheimer patients.

BACKGROUND: Impaired oxidative and energy metabolism are important features in Alzheimer's disease. These metabolic abnormalities may induce functional disturbances and are associated with significant cognitive impairment. OBJECTIVE: To determine whether mitochondrial function is altered by Alzheimer's disease, a quantitative analysis of substrates that enter the tricarboxylic acid cycle was carried out in cerebrospinal fluid (CSF) from Alzheimer patients. METHODS: Organic acid levels related to carbohydrate oxidation were measured in CSF from patients affected by dementia of Alzheimer type (n = 17) and from nondemented elderly controls (n = 17) using a gas chromatography/mass spectrometry system. CSF glucose and glutamine concentrations were determined by a quantitative enzymatic method and by ion exchange chromatography, respectively. RESULTS: Compared to age-matched controls, patients had a higher CSF level of lactate (p = 0.002) and a lower mean level of succinate (p = 0.002), fumarate (p = 0.003) and glutamine (p = 0.0005). The CSF glucose level was not modified. CONCLUSION: Our results suggest an impairment of mitochondrial oxidative metabolism in brain cells of patients with Alzheimer's disease.

Aged↗

Cerebrospinal fluid apolipoprotein E level is increased in late-onset Alzheimer's disease.

Worldwide evidence has recently shown that the allele epsilon4 of apolipoprotein E (ApoE) is a genetic risk factor for Alzheimer's disease (AD) underlining the possible role of apoE in the physiopathology of AD. To evaluate the usefulness of apoE concentration in pathogenesis of AD, we measured the cerebrospinal fluid (CSF) levels of apoE. CSF apoE level was significantly higher in 38 patients with late-onset AD than in 31 control patients and 47 patients suffering from other neurological and related diseases. Higher levels of CSF apoE were also present in a subset of patients with meningoencephalitis, motor neuron disease, and low back pain. The increase of CSF-apoE in AD is in agreement with results from studies that find an increase of mRNA apoE in the brains of AD patients. Compared to other works, these results underline the importance and the difficulties of the selection of the controls. The CSF apoE level seems to be a reflection of neuronal damage and/or an inflammatory reaction that may be common to AD and other neurological and related diseases.

Age of Onset↗

[Aneurysm of the thoracic aorta and spondylodiscitis disclosing brucellosis].

Brucellosis, which decreased during the eighties in France, remains a public health problem in many Mediterranean countries. We report the case of a 65-year old patient native of Morocco, of thoracic aorta aneurysm and lumbar spondylodiscitis due to Brucella melitensis, revealed by haemoptysis and lumbar pains, with a favourable outcome after aortic graft resection, spinal plaster immobilization and specific lengthy antibiotic treatment. This case report is characterized by the absence of endocarditis or infectious focus near the aneurysm. Diagnosis of aneurysm and spondilitis due to Brucella melitensis is based on imaging and bacteriological and serological examination. Because of a clinical and biological intolerance for rifampicin and cotrimoxazole, this patient received ofloxacin-doxycyclin-streptomycin. We discuss antibiotic recommendations and stress the interest of the early diagnosis of complicated forms of brucellosis for a better prognosis.

Aged↗

Effects of malnutrition and atherosclerosis on the fatty acid composition of plasma phospholipids in the elderly.

The fatty acid profiles of plasma phospholipids have been compared in 53 elderly subjects suffering from malnutrition (group U, 17 subjects) or from atherosclerosis (group A, 15 subjects). A control group was also included in the study (group C, 21 subjects). Main differences were observed in phosphatidylcholine (PC). In group U, the proportion of monounsaturated fatty acids increased in PC, which was reflected by an increase in unsaturated fatty acids without significant modification of essential fatty acids. In group A, no major modification has been observed statistically, although the proportion of saturated fatty acids tended to increase.

Aged↗

[Monoclonal gammopathy and primary hyperparathyroidism. Apropos of 2 cases and review of the literature].

Frequency of primary hyperparathyroidism (HP) is increased in neoplasia. Though uncommon, both HP and monoclonal gammopathy are not exceptionally associated as seen in a literature review reporting 24 observations. The mechanism of this association remains unclear but does not seems coincidental. Association of hypercalcemia with gammopathy does not suggest systematically malignant hypercalcemia and implies the search for hyperparathyroidism. The authors report two patients presenting respectively a multiple IgD myeloma and an monoclonal gammopathy of undetermined signification associated with a parathyroid adenoma.

Aged↗

Thymoma with immunodeficiency (Good's syndrome) associated with selective cobalamin malabsorption and benign IgM-kappa gammopathy.

We have described the first case, to our knowledge, in which recurrent respiratory tract infections were the primary manifestation of thymoma with immunodeficiency (Good's syndrome) associated with cobalamin malabsorption and immunoglobulin M-kappa (IgM-kappa) M component. The intrinsic factor receptor activity was dramatically decreased in a mucosal homogenate prepared from ileal biopsies. This decreased activity could be the principal cause of the malabsorption of labelled cobalamin which was observed in the presence of intrinsic factor. However, it could be the consequence of the cobalamin deficiency, as it is known that a cobalamin deficiency can affect the assimilation of cobalamin, even in presence of exogenous intrinsic factor.

Aged↗

Influence of muscle strength and body weight and composition on regional bone mineral density in healthy women aged 60 years and over.

Although weight, lean mass, fat mass and muscular strength are often found to be intercorrelated, the respective role of each parameter in bone mineral density (BMD) remains unknown in older women. The aim of the present study was to investigate the relationship between body weight and composition and quadriceps strength on femoral neck and lumbar spine BMD in healthy postmenopausal women. The relationship between isokinetic quadriceps strength measured by Biodex and BMD measured by dual energy X-ray absorptiometry was studied in 56 women aged 60-81 (70.5 +/- 6.2) years in multiple regression models adjusted for age, body composition and menopausal treatment. Weight and age were associated with femoral neck BMD (33 and 10% of variance accounted for, respectively) and lumbar spine BMD (23 and 8% of its variance). When body weight and quadriceps strength were excluded from the model, lean mass and age were associated with femoral neck BMD (29 and 14% of variance explained, respectively) and lumbar spine BMD (28 and 11% of variance explained, respectively). When quadriceps strength was entered into the model, it was strongly associated with femoral neck BMD (30% of variance accounted for), in addition to lean mass (9%) and age (7%), whereas it was not associated with lumbar spine BMD. In conclusion, lean mass explains a great part of the strong association between body weight and femoral neck and lumbar spine BMD. Quadriceps strength explains a great part of the association between lean mass and BMD at the femoral neck site but not at the lumbar spine site. These results suggest a site-specific effect of muscular strength on bone and a potential role of the age-related decline of muscle strength in age-related bone loss in postmenopausal women.

Age Factors↗