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Biomedical subjects

F Arnaud

Publications and source records attributed to F Arnaud.

33 records · Page 2Linked to original sources
PubMed1991

[Is it possible to avoid a penal offence in carrying out ambulatory anesthesia?].

French jurisprudence about outpatient anaesthesia is resolutely unfavorable. It is principally based on the June 22nd 1972 decision of the cessation court, the highest court of justice in France. Preoperative non hospitalisation has been considered as a fault by negligence/carelessness of the practitioners. It resulted in their penal condemnation for involuntary injuries and compensation for the harm. This decision is linked with the evolution of the fault and the responsibility share between surgeon and anaesthetist. The post-operative phase seems to involve "theory of missing luck" (causality linkage or the detriment in itself), excluding a penal condemnation but not a partial compensation. Though some new legal considerations could be put forward, a written contract between physicians and patients is necessary in outpatient surgery, whereas the medical files and the organisation of the unit can prove the quality of medical care.

Ambulatory Surgical Procedures↗
PubMed1990

Peripheral neuropathies in patients with chronic obstructive pulmonary disease: a multicenter prevalence study.

To investigate the prevalence and type of peripheral neuropathies (PNP) in patients with chronic obstructive pulmonary disease (COPD), we studied lung function and blood gases, clinical signs of PNP, and neurophysiological function in 151 patients with COPD without known risk factors for PNP. Mean (SD) age was 65 (10) years, mean arterial PO2 was 59 (9) mmHg, mean ratio of forced expiratory volume in the first second to vital capacity (FEV1.0/VC) was 42 (12%). Thirty patients (20%) had clinically detectable and 6 (4%) had subclinical PNP of mild degree. Fourteen (9%) of the patients with clinically detectable PNP had symptoms due to PNP. Prevalence of PNP increased with severity of hypoxemia (p less than 0.05) and was more pronounced in the lower than in the upper limbs. Age and the degree of hypoxemia were predictors to differentiate between COPD patients with and without PNP. Although the cause of PNP in COPD patients remains unknown, our observations suggest that chronic hypoxemia may contribute to PNP.

Adult↗
PubMed1987

Peripheral neuropathies during hypoxaemic chronic obstructive airways disease.

Peripheral nervous system alterations during chronic obstructive airways disease (COAD) with respiratory insufficiency seem more frequent than usual neurological practice would suggest. Almost a third of COAD patients have clinical evidence of peripheral neuropathy and two thirds have electrophysiological abnormalities. The presentation consists of a polyneuropathy often subclinical or with predominantly sensory signs, which has the neurophysiological and pathological features of predominantly axonal neuropathy. The presumed etiopathogenic factors are multiple: chronic hypoxia, tobacco smoke (which contains at least three neurotoxic constituents) alcoholism, malnutrition and adverse effects of certain drugs. Hypoxia probably plays the leading part, either by direct action on nerves fibres or by enhancing the effects of other neurotoxic factors or deficiencies.

Alcohol Drinking↗
PubMed1987

Evolution of peripheral nerve function in hypoxaemic COPD patients taking almitrine bismesylate: a prospective long-term study.

Almitrine bismesylate has been thought to provoke peripheral neuropathies in patients with chronic obstructive pulmonary disease (COPD). However, there seems to exist alterations of peripheral nerve function in patients with COPD, who have not taken almitrine. We have therefore examined 22 patients with COPD and no other cause of peripheral neuropathy (PN), before and after 6 and 12 months of treatment with almitrine (50 mg bd). Seventy-eight similar patients, who did not take almitrine, were also studied (controls). Sixty-four per cent of controls, and 55% of almitrine patients initially had at least one neurophysiological abnormality. There was no change in the studied parameters after 6 months and one year's treatment with almitrine.

Aged↗
PubMed1985

Bone marrow separation, purification and cryopreservation: application for autologous bone marrow transplant (ABMT).

Autologous bone marrow transplantation is used in the treatment of patients suffering from malignant diseases. The intention of this study was to develop a technique for cryopreservation of bone marrow stem cells. A technique of purification described elsewhere (2), gave recoveries of 80% of nucleated blood cells and 87% of mononucleated blood cells after apheresis and centrifugation of buffy-coat, but when applied to bone marrow only 59% of NBC and 32% of CFUc have been harvested. We therefore modified the apheresis technique and replaced the centrifugation step by sedimentation with hydroxy-ethyl-starch. This change resulted in a small but significant increase in the yield of bone marrow cells and improved the asepsis of the procedure. From a second group of bone marrow handled with this modified protocol, final yields of 46% of NBC and 62% of MNC were obtained. After cryopreservation 87% of NBC were recovered as assessed by counting.

Adolescent↗
PubMed1984

Comparison of the cryoprotection of red blood cells by 1,2-propanediol and glycerol.

Red blood cells are cooled in buffered solutions containing 10, 15, 20, 30, or 35% (w/w) 1,2-propanediol or glycerol. Cell survival is measured after cooling to -196 degrees C at rates between 1 and 3500 degrees C/min, followed by rewarming rapidly, except in a few cases. At low cooling rates, where the injuries are due to solution effects, for the same (w/w) concentrations of 15 or 20% (w/w), 1,2-propanediol protects erythrocytes better than glycerol. Differences are still observed when the two cryoprotectants are compared on a mole-fraction basis. At high cooling rates the survival passes through a minimum and then increases again. For the same concentrations, the minimum occurs at much lower cooling rates with 1,2-propanediol than with glycerol, in agreement with the better glass-forming tendency of 1,2-propanediol solutions. These cooling rates almost coincide with those at which the quantity of ice crystallized begins to decrease in the corresponding solutions. Thus, survival seems to be closely related to the glass-forming tendency at the survival minimum, and at higher cooling rates. After the fastest cooling rates, the warming rates necessary to avoid damage on warming are much smaller than those necessary to avoid devitrification. Therefore, in the present experiments the survivals are not related to the stability of the wholly amorphous state. However, injury follows the presumed transition from cubic to hexagonal ice, in erythrocytes as well as in other kinds of cells.

Blood Preservation↗
PubMed1984

Comparison of apheresis and other methods for separation and purification of hemopoietic stem cells: initial experience with a blood buffy coat model for the use of autologous bone marrow transplantation.

With an increasing number of bone marrow transplantations (BMT) being contemplated in leukemia and cancer patients, it is prudent for blood banks to develop a suitable program within their resources for harvesting, purifying and freezing bone marrow stem cells. In order to do this, initially a prototype has been developed involving buffy coat model (BC) using normal donor blood. Centrifugation, sedimentation and machine apheresis methods were separately evaluated leading to a combined and sequential handling procedure. Blood was passed through a cell separator resulting collection of BC with 90% reduction of the volume showing 80% recovery of total leucocytes and 87% yield of mononuclear cells. Following centrifugation the cells with DMSO were frozen in a controlled freezing system and stored in liquid nitrogen. After thawing 94% cells were recovered with 93% viability. The initial experience gained in the model system could be incorporated in autologous BMT program in patients but requires modifications for improved results; the latter will be described separately.

Blood Cells↗
PubMed1983

Autologous cryopreserved platelets and prophylaxis of bleeding in autologous bone marrow transplantation.

Autologous platelets were harvested and cryopreserved in eight consecutive patients elected for ablative chemotherapy and autologous bone marrow transplantation (ABMT) for solid malignancy. There was a 19% loss in platelet count after the freeze thaw and wash procedure; with an in vitro functional loss of 40-60%. No correlation could be found for individual platelet transfusions between in vitro functional tests and in vivo recovery. Six consecutive patients received a total of 16 autologous platelet transfusions in the aplastic phase of ABMT. No bleeding was observed during the study period and there was no CMV infection in the recipients. While improvement in freezing and subsequent handling is desirable, autologous cryopreserved platelets can safely be used for the prophylaxis of bleeding during aplasia in patients treated with ABMT.

Adolescent↗
PubMed1978

[New therapeutic indications for a dopamine antagonist, Piribedyl].

Evidence has been found for the view that piribedil stimulates peripheral and central dopamine receptors. Piribedil stimulates the nigro-striatal pathway and has been shown to be an effective antiparkinsonian agent. The stimulation of dopamine receptors in the meso-limbic and/or meso-cortical pathways lead to propose its use in the treatment of affective disorders (maia and depression). Piribedil stimulates dopamine receptors located in the tubero-infundibular pathway and reduces the secretion of prolactine, producing ablactation ; it increases the secretion of STH. Recent studies suggest that the peripheral effects of piribedil, mainly the increases in femoral and cerebral blood flows are also due to stimulation of peripheral dopamine receptors.

Affective Symptoms↗
PubMedDate not supplied

Measurement of transmitted light as an indicator of cryopreserved platelet viability.

This study was designed to establish an alternative technique to the morphology scoring method described by Kunicki et al. [Transfusion 1975;15:414-421] using light transmission. A reference scale for platelet quality (expressed as a percentage of fresh cells) was established with a mixture of fresh platelets and damaged platelets frozen without cryoprotectant. The transmittance, read against autologous plasma, was compared to morphology, hypotonic stress response (HSR) and ADP-induced aggregation. The results showed that transmittance, morphology and HSR were related linearly to the percentage of fresh platelets. There was a significant correlation between relative transmittance (RT) and morphology (r = 0.932), and RT and HSR (r = 0.91), but a very poor correlation was found between transmittance and aggregation. Measurements of transmittance provided an estimation of the global aspect of a population of cryopreserved platelets in terms of shape, size and composition, and the relative transmittance of a sample to that of the fresh population could predict morphology and HSR. It is concluded that these measurements offer a valid alternative method to the subjective morphology scoring obtained with cryopreserved platelets.

Adenosine Diphosphate↗
PubMedDate not supplied

[Hypoxemia and aging (author's transl)].

Hypoxemia during rest reveals the aging of the respiratory tract. The evolution curve of the PaO2 related to age is parallel to that of static elastic recoil pressure. This hypoxemia is moderate and without any serious functional consequences in a healthy subject. Abnormalities of the ventilation-perfusion ratio are the main causes. The increase of the anatomical dead space and the increase of the right-left shunt only play a moderate part. On the other hand the increase of closing volume seems the major factor. Thus the ventilation distribution becomes dependent on the amplitude of the tidal volume. The response of the aged subject to hypoxia is lessened for mechanical and neurological reasons explaining why a respiratory distress can appear rapidely and sometimes unexpectedly.

Adaptation, Physiological↗