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Biomedical subjects

M Roudier

Publications and source records attributed to M Roudier.

51 records · Page 3Linked to original sources
PubMed1982

Plasma corticosterone during perinatal period in postmature rats.

In the fetal rat, plasma corticosterone concentration (PCC) decreases dramatically on the 20th day of gestation and remains low until birth even if the parturition is delayed until 23.5 days postcoitus. In the normal term newborn, there is an increase of PCC in the 1st h after birth. In postmature newborn rats this increase is not present but PCC can be increased towards normal term values if the adrenal cortex is stimulated with cosyntropin or lysine-vasopressin. This suggests that the lack of elevation of PCC in the postmature newborn is not due to the lack of responsiveness of the adrenal cortex but rather an impairment of the hypophyseal stimulation. The absence of PCC elevation at birth could contribute to the metabolic disorders observed in the postmature newborn rat.

Animals↗
PubMedDate not supplied

Biomedical applications of maghemite ferrofluid.

The use of cell-targeted ferrofluid in the characterization of modifications of cell membranes is reviewed. Maghemite ferrofluid was synthesized by the Massart method, complexed with dimercaptosuccinic acid (FF). Cell targeting by FF was developed by coupling FF to various biological effectors such as antibodies, lectins, etc, which enabled magnetic cell sorting. Modifications in erythrocyte membranes were studied using FF bound to recombinant human annexin V (AnxFF) which is very sensitive, compared to other Anx-based reagents, in the early detection of phosphatidylserine (PS) exposition on the outer leaflet of the plasma membrane. Thus PS exposition on mouse RBC was detected already after a 24-h storage at 4 degrees C and, transiently, 24 h after their infection by Plasmodium parasites, at which time the parasites are still confined to the liver, thus leading to the recruitment of young RBC and the accumulation of a species, intermediate between reticulocytes and erythrocytes, and the actual RBC target of plasmodial invasion. AnxFF revealed PS exposition on RBC from sickle cell anemia patients, following various inflammations and already after 20 days of human blood storage under blood bank conditions. Such a sensitive detection should be similar to that of macrophages which recognize exposed PS on cells and bring about the latter's elimination from the circulation. AnxFF binding determination was combined with that of cell electrophoretic mobility, glycerol resistance and filterability to characterize RBC membrane modifications in Alzheimer's disease patients which suggested a continuous damage and regeneration in RBC of these patients. A logistic analysis suggested that several three-parameter combinations could permit diagnosis of Alzheimer's disease with up to 95% accuracy. THP1 cells and macrophages, derived themselves by incubation with retinoic acid, were bound to FF and placed in a radio frequency alternating magnetic field. Magnetocytolysis was associated with FF attachment to the cells without damage to non-bound cells and without heating of the surrounding solution.

Alzheimer Disease↗
PubMedDate not supplied

[A battery of neuropsychological tests for severe dementia. An evaluation study].

All patients with Alzheimer's disease progress, more or less rapidly, to a stage where they can no longer be tested with the standard neuropsychological tools. The Severe Impairment Battery (SIB) is a neuropsychological tool used to evaluate patients with severe dementia. Its maximum score is 133. The purpose of this study was to assess the reliability of a French version of SIB. Fifty-four patients with Alzheimer's disease (mean Mini Mental State examination [MMS] 10.11 +/- 6.38) entered the study. Their mean SIB score was 88.4 +/- 33.3. The patients who were most affected (MMS below 5) were distributed by SIB from 7 to 80 points. An inter-examinator study of 36 patients yielded a correlation coefficient r = 0.9957 (P = 0.0001). In an inter-test study of 17 patients the correlation coefficient was also very high (r = 0.874, P = 0.0001). Thus, SIB seems to be a reliable tool to evaluate cognitive functions in cases of severe dementia. The distribution of scores obtained by SIB in patients with an MMS below 10 demonstrates that even within groups of subjects with severe dementia distinctions can be made between their remaining capabilities. Using SIB in these patients should improve our knowledge of the natural course of the disease and give better correlation between clinical data and neuropathological and neurobiochemical tests on the one hand, and enable us to adjust to their condition the departments where these patients are treated on the other hand.

Aged↗
PubMedDate not supplied

[Neuropathologic validation of clinical diagnosis of senile dementia of the Alzheimer type].

The purpose of this work was to establish a neuropathological confirmation of the clinical diagnosis of senile dementia of the Alzheimer type (SDAT) in a group of patients prospectively studied in a geriatric hospital since 1984 (Charles Richet Study). The sample consisted of 45 cases, 35 of which had received a clinical diagnosis of SDAT and 10 others a diagnosis of either vascular or mixed dementia. The mean age at death was 85 +/- 6.9 years (range 64-97). The neuropathological diagnosis was established independently of the clinical findings. Senile lesions typical of SDAT were found in 32/35 cases, giving a 91.4% rate of clinico-pathologic agreement. However, vascular lesions were present in 10 cases (28.5%) and the final pathologic diagnosis was mixed dementia, lowering the score of agreement for SDAT to 63%. Considering that the pathological criteria for the diagnosis of SDAT are not uniform, we independently applied 3 inclusion (senile lesions) and 3 exclusion (vascular lesions) criteria for the diagnosis of SDAT to each of the 45 cases. This permitted a comparison of nine combinations of neuropathological criteria with the clinical diagnosis. The sensitivity values ranged from 37 to 80% and the specificity values ranged from 55 to 100%. The highest agreement rate with the clinical diagnosis was achieved when were associated the criterion which specified that plaques and tangles must be present in the hippocampus regardless of neocortical findings and the criterion which excluded cases with vascular lesions of any site if their volume was 50 ml or more.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

[Standardized neurologic study in senile dementia of Alzheimer's type].

Seventy five patients affected by senile dementia of the Alzheimer type (mean age 82) have been submitted to a standardized neurological examination of 88 items. Gait abnormalities were present in 57% of the cases. Extrapyramidal symptoms (akinesia or rigidity or tremor) were noticed in 64% of the cases but they were rarely associated with a typical parkinsonian syndrome. Myoclonus was observed in only 4 patients. The gait abnormalities were significantly associated with the presence of rigidity and grasp reflex but not with other primitive reflexes. The only symptoms to be correlated with dementia severity as assessed by the Mini Mental State were rigidity and optokinetic nystagmus abolition. Tremor and amyotrophy of the hands appeared to be negatively correlated to dementia severity.

Aged↗
PubMedDate not supplied

[Quantified neuropsychological study in senile dementia of Alzheimer's type].

Forty six patients affected by senile dementia of the Alzheimer type and 20 control subjects of similar age, sex and educational level have been studied, using a quantified neuropsychological battery (Wechsler memory scale, Raven progressive matrices and quantified tests for aphasia, apraxia and agnosia). There was a significant correlation between the scores of all cognitive functions with one another and with the Mini Mental State. The results show a rather global impairment of cognitive functions in these patients and suggest that intellectual impairment progresses as a continuum in senile dementia of the Alzheimer type.

Aged↗
PubMedDate not supplied

The Hoffmann reflex (H-reflex) in senile dementia of the Alzheimer's type--preliminary results.

The Hoffmann reflex (H-reflex) and direct motor response (M) were investigated (latency, amplitude and excitability curves were analyzed) in patients with senile dementia of the Alzheimer's type (SDAT). M responses had similar latencies in SDAT patients and old control subjects. H reflex latencies were similar in SDAT patients and old control subjects but longer than in younger controls. The H max/M max ratio was also lower in SDAT patients and old control subjects than in younger controls. The excitability curve of the H-reflex (using a double shock procedure) in SDAT patients was lower than in non-demented old controls for all values of the interstimulus intervals.

Aged↗