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Biomedical subjects

L Chaix

Publications and source records attributed to L Chaix.

10 recordsLinked to original sources
PubMed2001

[Long-term treatment of Alzheimer's disease: followup of a cohort of 255 patients treated with lacrine for four years].

We describe the follow-up of a cohort of 255 Alzheimer's disease (AD) patients (81 males, 174 females) treated by tacrine during 4 years. We performed the survey of hepatic, cholinergic and general tolérance. Drug efficacy was measured by MMS examination on weeks 0, 18, 30, 52, 104, 156 and 208. A total of 190 patients (74.5 percent) were dropped out of this study, 75 (29 percent) for adverse events. We found 85 hepatic (33 percent), 79 cholinergic (31 percent), 31 (12 percent) neuropsychiatric and 72 general (28 percent) side effects. In term of drug efficacy we observed a global decline of 2.5 MMS points during the first year and 2 MMS points between W52 and W156. Tacrine's symptomatic efficacy, defined as the number of patients improved or stabilized at W30, was present in 50 patients (46 percent) among the 109 patients reaching W30. The intensity of symptomatic efficacy was expressed by a 2.7 MMS points increase in 37 patients improved on W30. The long term effects of Tacrine, measured by the MMS score at one year, showed a positive impact as the MMS was 2.5 points above the expected score in non treated AD patients. This study raises the practical problem of optimal cholinesterase inhibitors use in AD and the theoretical question of long term action of cholinesterase inhibitors on cerebral lesions of AD.

Aged↗
PubMed2000

Reanalysis and New Measurements of N(2) and CH(4) Adsorption on Ice and Snow.

Numerous literature data indicate that the mean heat of adsorption of a monolayer of N(2) (DeltaQ(N(2))) on ice or snow at 77.15 K, determined by volumetric methods, is highly variable, suggesting that ice surface properties strongly depend on its mode of formation and its thermal history. Less numerous data on CH(4) adsorption show smaller variations of DeltaQ(CH(4)). If such variations are real, the extrapolation to atmospheric chemistry models of adsorption parameters measured on laboratory-made ice may be unwarranted. We have measured CH(4) adsorption on variable amounts of a crushed ice sample, to show that when the total surface area of the sample is below a threshold value, DeltaQ(CH(4)) decreases. We identify the cause of this artifact as an error in the molar budget, because the temperature gradient in the tube connecting the introduction and expansion volumes is not taken into account. Performing an adequate molar budget suppresses this artifact, except for ice samples with very small total surface areas, where the resolution of the manometer becomes a limiting factor and a further decrease in DeltaQ(CH(4)) is observed. Error in DeltaQ(gas) results in large errors in surface area, and we suggest that the value of DeltaQ(gas) obtained can be used to test the reliability of the surface area measurement. Copyright 2000 Academic Press.

Journal Article↗
PubMed1999

mtDNA analysis of Nile River Valley populations: A genetic corridor or a barrier to migration?

To assess the extent to which the Nile River Valley has been a corridor for human migrations between Egypt and sub-Saharan Africa, we analyzed mtDNA variation in 224 individuals from various locations along the river. Sequences of the first hypervariable segment (HV1) of the mtDNA control region and a polymorphic HpaI site at position 3592 allowed us to designate each mtDNA as being of "northern" or "southern" affiliation. Proportions of northern and southern mtDNA differed significantly between Egypt, Nubia, and the southern Sudan. At slowly evolving sites within HV1, northern-mtDNA diversity was highest in Egypt and lowest in the southern Sudan, and southern-mtDNA diversity was highest in the southern Sudan and lowest in Egypt, indicating that migrations had occurred bidirectionally along the Nile River Valley. Egypt and Nubia have low and similar amounts of divergence for both mtDNA types, which is consistent with historical evidence for long-term interactions between Egypt and Nubia. Spatial autocorrelation analysis demonstrates a smooth gradient of decreasing genetic similarity of mtDNA types as geographic distance between sampling localities increases, strongly suggesting gene flow along the Nile, with no evident barriers. We conclude that these migrations probably occurred within the past few hundred to few thousand years and that the migration from north to south was either earlier or lesser in the extent of gene flow than the migration from south to north.

DNA Mutational Analysis↗
PubMed1995

[Rotablator and endoprosthesis on the left main coronary trunk].

A 78 year old woman with unstable angina due to significant stenosis of the left main coronary artery and occlusion of the right coronary artery was treated medically for 29 months because of a surgical contraindication. Resistance to drug therapy led to referral for complex angioplasty of the left main, left anterior descending and left circumflex arteries, successively by rotablator and balloon angioplasty. An immediate elastic recoil on the left main coronary artery led to implantation of a Palma-Schatz stent. There were no complications and the patient is asymptomatic twenty months later.

Aged↗
PubMed1994

[Thromboembolic disease in patients aged 80 and over. Diagnostic and therapeutic strategies].

The aim of this retrospective study of 50 deep vein thromboses (DVT) of the lower limbs in patients aged 80 and over (35 women, including 2 with bilateral DVT and 13 men), mean age 83.37 +/- 2.72, hospitalised in a department of cardiology, was to assess the diagnostic value of ultrasound investigations, clinical parameters and results of treatment of thrombo-embolic disease in this age group. High DVT were found in 76 per cent of cases and pulmonary embolism occurred in 52.1 per cent of cases, its incidence increasing with age. One third of DVT were asymptomatic and presented as pulmonary embolism, the predominant clinical feature being edema in the absence of other signs. The existence of atrial fibrillation was associated in 90 per cent of cases with a pulmonary embolism. Venous Echo-Doppler is also the key investigation in the diagnosis of thrombo-embolic disease. Cardiac Echo-Doppler seems particularly useful in the diagnosis of pulmonary embolism when more than 40 per cent of the vascular bed is cut off. Thrombolytic treatment remains possible after the age of 80 in life-threatening situations. Overall hospital mortality remains high (10.4 per cent) and appears to be due chiefly to the onset of a pulmonary embolism which is not thrombolyzed since considered insufficiently serious or occurring in a situation in which fibrinolysis is theoretically contra-indicated.

Aged↗
PubMed1986

[Auricular fibrillation in the elderly. Indicators of risk and cerebral prognosis].

Cardiovascular anomalies contributing to development of atrial fibrillation (AF) and subsequent cerebral repercussion have been studied by analysis of clinical, electrocardiographic and anatomicopathological data for 131 elderly (85.16 +/- 6.7 years) medium- and long-term hospital patients. AF was seen in 22.14% of cases and seems more frequent in the ninth decade than in the eight. Predisposing factors were coronary alterations of repolarization (p less than 0.001), myocardial hypertrophy (less than 0.01), hypertension with cardiac repercussions (p less than 0.01), intraventricular conduction disorders, left anterior hemiblock excepted (p less than 0.05) and mitral valvulopathy. AF developed in 12% of cases without apparent cardiopathy. The risk of cerebral infarct was marginally greater in the presence of AF than in its absence; the risk was clear for paroxysmal forms and nil when AF developed in a healthy heart. In contrast, intellectual deterioration and cerebral hypotrophy were significantly more marked (p less than 0.01) in patients presenting AF. This affirmation is evidence for long-term hemodynamic repercussions of arrhythmia affecting cerebral blood flow and constitutes an argument for re-establishment of sinusal rhythm.

Aged↗
PubMed1986

[Risk factors in the combination of myocardial infarction and carotid atheroma].

This study compares two groups of patients: Group I with 44 patients who suffered recent acute myocardial infarction and Group II: 40 control subjects. In both groups, 2D Doppler echocardiography was performed to detect carotid atheroma, to determine the respective roles of vascular risk factors for two sites of atherosclerosis. Carotid atheroma affected 73 p. 100 of subjects in Group I and 22.5 p. 100 in Group II. Carotid stenosis of more than 40 p. 100 was found mainly in hypertensive patients who presented with acute myocardial infarction, and in patients with left ventricular hypertrophy. Smoking was more frequent in Group I than in Group II (p less than 0.001) irrespective of the frequency of carotid atheroma (p less than 0.05). Hypercholesterolaemia only favoured carotid atherosclerosis after acute myocardial infarction (p = 0.01). We did not find any difference in the incidence of diabetes mellitus in the two groups of patients. Age analysis indicated that carotid atheroma occurred earlier in Group I than in Group II. An association between a dominant risk factor for coronary disease (smoking or hypercholesterolemia) was found in 9 patients, all of whom had severe bipolar atherosclerosis with multivessel coronary lesions and carotid stenosis.

Adult↗