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Biomedical subjects

M Robert

Publications and source records attributed to M Robert.

At least 181 records · Page 10Linked to original sources
PubMed1990

Perception and representation of the Euclidean coordinates in mature and elderly men and women.

Research on gender differences in visuo-spatial tasks has been mostly limited to samples of preadolescents, adolescents, and young adults. In a life span perspective, the present study attempted to complete the available information by submitting mature and elderly men and women to three tasks involving the Euclidean spatial system. Aged 40 to 61, 62 to 72, and 73 to 84, and maximally equivalent across age and sex groups, the subjects performed the Rod-and-Frame Test, the water-level task, and a plumb-line task. Proficiency was expected to decrease with age and to be higher among men. It was found that, whatever their age, men surpassed women in the water-level and plumb-line tasks, whereas no gender difference was obtained on the Rod-and-Frame Test. Irrespective of sex, the oldest subjects were outperformed by the youngest on the Rod-and-Frame Test, while water-level and plumb-line achievement was independent of age. Depression and anxiety scores were not correlated with visuo-spatial performance. Discussion focused on the fact that the present highly homogeneous and selective sample allowed for the valid emergency of a distinctive pattern of gender and age contributions to the use of appropriate vertical and horizontal references once maturity is reached.

Adult↗
PubMed1990

[Organ procurement in pediatrics. General and ethic aspects].

The progress in organ transplantation is leading an increase in the demand for organs. Any non-harvested organs from a dead child mean at least a delay or even the loss of hope for life. All brain dead children do not undergo organ harvesting because there are still obstacles. The definition of brain death must be clear and include the destruction of all the brain system. Intensive care units must be motivated by improved contacts with transplantation teams. The number of parents who refuse could decrease with better public information, good contacts with medical teams and the quality of discussion with parents when a child dies. Energy should be concentrated on improving the collective consciousness about this new aspect of medicine.

Attitude↗
PubMed1989

Reduction of demand characteristics in the measurement of certainty during modeled conservation.

The purpose of the present experiment was to document the cognitive processes mediating the observational learning of conservation. Two formats for measuring certainty were contrasted among nonconservers assigned to one of give groups. Under a public format, two groups used a certainty rating scale and showed the experimenter how sure they were about the correctness of a peer model's statements. Under a private format, two groups employed the same scale but were assured that their rating was not known by the experimenter. Within each format, one group was presented with the model's conservation answers and one group with the model's opinions on arbitrary matters. Conservation was demonstrated to the fifth group which did not perform the certainty assessment. All conservation groups were post-tested immediately after modeling and 6 weeks later and all groups displayed equivalent stable learning. Whereas public certainty was constantly high, private certainty increased as the model proceeded through conservation exemplification, in accordance with a hypothesis of sequential imitation and comprehension processes. Private certainty was also higher for conservation than for opinion, although not on the first two items. Public certainty was high regardless of modeled content, and public rating latency was always found to be shorter. These results strongly suggested the presence of demand characteristics for high undifferentiated ratings under the public format of certainty appraisal. This contamination prevented valid monitoring of the course of cognitive rule processing.

Attention↗
PubMed1989

G-protein dependent potentiation of calcium release from sarcoplasmic reticulum of skeletal muscle.

Skinned fibre experiments were conducted to determine if guanine nucleotide-binding proteins play a role in excitation-contraction coupling of skeletal muscle. By itself, the GTP-gamma S, a non hydrolysable GTP analogue was unable to induce calcium release from the sarcoplasmic reticulum, even at concentrations as high as 500 microM. However, calcium- or caffeine-induced calcium releases were enhanced by GTP-gamma S in micromolar concentrations. This response was blocked by GDP-beta S or Pertussis toxin. 32P-ADP-ribosylation catalysed by Pertussis toxin, radiolabelled G-protein alpha subunits in the range of 40 kDa on membrane subcellular fractions of rat skeletal muscle. Using Western blot analysis with antibodies raised against the bovine transducin, G-proteins were identified in frog and rat skeletal muscle subcellular fractions. In most of the muscle fractions (plasma membrane, T-tubules, triads, sarcoplasmic reticulum), the anti-beta subunit antibodies recognized a 36 kDa protein which comigrated with transducin beta subunit. It appears therefore that some of the G-proteins identified by ADP-ribosylation or immunostaining in several subcellular fractions from skeletal muscle, are implicated in the modulation of calcium release from sarcoplasmic reticulum. These results suggest that a Pertussis toxin sensitive G-protein is present at the loci of E-C coupling, and that it serves to regulate the calcium release.

Adenosine Diphosphate Ribose↗
PubMed1989

Antibiotic therapy of perforated appendicitis in children: a comparison of amoxycillin/clavulanate with a combination of benzylpenicillin, netilmicin and metronidazole.

This multicentre trial compared the clinical efficacy of amoxycillin/clavulanate used as a single-agent therapy with that of the three-agent combination usually prescribed in the post-operative period for appendicular peritonitis in children. Only bacteriologically documented peritoneal infections were included. Sixty-four patients were randomly distributed between two groups: Group A (29 cases) treated with amoxycillin/clavulanate, first administered iv (100 mg/kg/day) followed by conversion to the oral route (50 mg/kg/day) once the patient had been afebrile for 48 h; Group B (35 cases) first treated by the iv route with benzylpenicillin (100,000 IU/kg/day) plus netilmicin (5 mg/kg/day) plus metronidazole (30 mg/kg/day) followed by conversion to the oral route for metronidazole (30 mg/kg/day). In both groups, the total duration of parenteral and oral treatment was not less than five days. A total of 180 bacterial strains were recovered from peritoneal fluid samples obtained during surgery; 86% of these were sensitive to amoxycillin/clavulanate. Clinical efficacy, assessed on the basis of time until return to normal temperature and gut transit and duration of hospitalization, was identical in both groups, with follow-up monitoring on day 30 showing recovery in all cases. Cure was obtained without any problems of infection in 25/29 patients in group A and in 34/35 patients in group B (non-significant difference). Tolerance was excellent and identical in the two groups with the exception of three cases of thrombophlebitis which occurred in group B. The results of this study suggest that amoxycillin/clavulanate may be useful as single-agent therapy as a first-line curative treatment for appendicular peritonitis in children.

Amoxicillin↗
PubMed1989

[Rectal injury caused by a broken thermometer. Risks related to mercury].

This is a case of local mercury absorption caused by accidental rectal perforation during monitoring of temperature. This complication is only reported in cases of subcutaneous injury by a broken thermometer. Treatment necessitates complete excision of mercury deposits. When mercury remains, a clinical and biochemical follow-up is necessary but indication for chelation therapy is exceptional.

Foreign Bodies↗
PubMed1988

cGMP phosphodiesterase of retinal rods is regulated by two inhibitory subunits.

The cGMP phosphodiesterase (PDE) of cattle retinal rod outer segments comprises three types of subunits: the two heavy catalytic ones, PDE alpha and PDE beta, each around 85 kDa, and the light inhibitory one, PDE gamma or I (11 kDa). The relative stoichiometry is usually assumed to be 1:1:1. PDE activation in the visual transduction cascade results from removal of the inhibitor by the alpha subunit of transducin (T alpha). The stoichiometric complex T alpha-I, separated from activated PDE, has been isolated and characterized. Analyzing now the activated PDE, we find that it still contains some inhibitor and is resolvable into two species, one with 50% of the inhibitor content of the native enzyme and the other totally devoid of it. The same two species are observed upon activation of PDE by very short tryptic proteolysis, which specifically degrades the inhibitor. This leads us to conclude that the composition of the native enzyme is PDE alpha beta-I2. The two inhibitory subunits are differentially bound, sequentially removable, and exchangeable between the native complex PDE alpha beta-I2 and the fully active PDE alpha beta. The possibility of this exchange precludes as yet an unambiguous estimate of the actual activity of the intermediate complex PDE alpha beta-I. The differential binding and the exchangeability of the inhibitors raises the possibility of a fast, diffusion controlled, switch-off mechanism of PDE activity after a flash, which would shortcut the inactivation resulting from the slow GTPase rate of transducin.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1988

Hyperthyroidism due to selective pituitary resistance to thyroid hormones in a 15-month-old boy: efficacy of D-thyroxine therapy.

A 15-month-old boy had clinical features of hyperthyroidism. In spite of elevated serum thyroid hormone levels (mean serum T4, 230 nmol/L; T3, 4.2 nmol/L), serum TSH levels ranged between 3.3-5.6 mU/L and rose to 35.4 mU/L after TRH stimulation. There was no abnormal serum thyroid hormone binding or any evidence of a pituitary tumor. The boy was treated with carbimazole for 6 months and became euthyroid. However, his thyroid size enlarged, and serum TSH rose to 45 mU/L. In an attempt to suppress TSH secretion, 3,5,3'-triiodothyroacetic acid was added to carbimazole in daily doses from 0.7-1.4 mg. This combined therapy failed to suppress TSH secretion (serum TSH, 10.2 mU/L) and led to recurrence of symptoms of hyperthyroidism. A trial using highly purified dextrothyroxine (contamination by L-T4, 0.05%) as sole therapy then was carried out. Serum TSH levels promptly declined to normal, both basally and after TRH stimulation (basal, 2.4 mU/L; peak, 13.8 mU/L). During a 24-month follow-up period, the boy remained euthyroid. Serum TSH levels remained in the normal range, as did his serum L-T4 levels (93 nmol/L). Complete remission was achieved using a 5-mg daily dose of D-T4. Temporary discontinuation of D-T4 led to prompt relapse of hyperthyroidism. Our patient's TSH hypersecretion appears to be due to selective pituitary resistance to thyroid hormones. Purified D-T4 effectively inhibited TSH secretion in this patient, without inducing significant side-effects, even when the daily dose was high. The cause of partial pituitary unresponsiveness to thyroid hormones is not known. We suggest that transport of thyroid hormones into the thyrotroph cells could be deficient in our patient.

Dextrothyroxine↗
PubMed1988

[Lacerations of the perineum in children].

24 cases of disruption of the perineum from 8 Centres of Pediatric Surgery in France, were studied. The patients were aged between 4 months and 13 years, with an average age of 6.7 years, and 70% were boys. The cause of the injury was crushing in 13 cases. The associated were complex. Fractures of the pelvis (18) and associated multiple fractures (13), as were as profuse pelvi-peritoneal haemorrhages arising from fractures (3) or lower limb amputations (3) determined the care of associated soft-tissue injuries. Disruptions of the skin were almost constant and displayed a high rate of sepsis. There were noted lesions of the ureter (9), the vagina (5), the anus and rectum (17), the ano rectal sphincter (10) and the penis (1). The care of each of these lesions followed the usual practices of Reparative Surgery specific to each organ, but was also adapted to each case. In effect, disruptions of the perineum take place in a context of serious polytrauma, where the hierarchy of urgency determines the choice of therapeutic attitudes.

Adolescent↗
PubMed1988

[Pelvic and genital injuries in children. Sexual injuries of young girls. Management in a medico-legal context].

In the emergency care of a young girl presumed to be a victim of sexual assault and the treatment of the lesions discovered in the perineum and vulvo-vaginal tract, the paediatric surgeon must take into consideration the medico-legal aspects of the file right from the first approach to this young victim. It would actually be damaging to her if a paediatric surgeon reconstituted the perineal tissues, vulva and vagina "ad integrum" without carefully describing the lesions observed and without, whenever possible, taking good quality photographs to be kept in the case file to support the evidence of sexual assault, if a criminal procedure is filed. Similarly, as a complement to this assessment of the initial lesions, the surgeon must be able to establish an anatomical and functional assessment of the vulvo-vaginal tract after healing, to enable the experts appointed by the court to determine the basis for compensation of bodily damages related to the sexual assault and the expenses entailed by further plastic operations required by the sequelae of the genital lesions. The bases for a pretium doloris, future aesthetic, sexual and obstetric damages should also be indicated in any certificate given to the patient's family or to the court experts. Thus, if the surgeon participates indirectly in demonstrating evidence of the crime subject to penal sanction, he can help the victim in her parallel civil court action for compensation of her bodily damages before the repressive jurisdiction.

Child↗
PubMed1988

[Traumatic epiphyseal separation of the lower end of the femur].

Forty-one children suffering from displacement of the distal femoral epiphysis were reviewed with a five year follow-up. This is a rare lesion, caused by severe trauma. It is seen at all ages, four of the cases being neonatal, but principally in adolescence, in 22 cases. The Ogden classification is preferable to the Salter-Harris classification for these fractures, which are usually in type II (39 cases). The prognosis is related to the severity of the initial displacement and to the quality of the reduction and its maintenance. Epiphysoidesis developed frequently and early, in 15 cases. It seemed to be due to an initial vascular injury rather than to mechanical compression. The results were not very satisfactory with 23 good, 11 fair and 7 bad results. It is recommended that an anatomical reduction should be maintained by percutaneous crossed pins. In adolescents aged 15 years or over, primary surgical epiphysiodesis of the whole growth cartilage seems to be a reasonable possibility.

Adolescent↗
PubMed1988

[Osteoid osteoma of the femur neck in children and adolescents. Apropos of 12 cases].

Specific characters of the osteoma osteoid as a beniGN tumor are well known. We report twelve cases of femoral neck localisation. Delays in diagnosis of six months to one year after the onset of symptoms are quite common. Chronic or recurrent pain is localised in the inguinal area with a projection to the leg and to the knee. The pain was relieved by Aspirin in six cases only. X ray of the pelvis antero-posterior showed the tumor, but did not always show the lucent image with the surrounding sclerotic area that is well observed with tomography. The scintigraphy with technetium 99 is perhaps more sensitive as a way of diagnosis. The lesion is the place of intensive uptake. Although the surgical excision "in block" and the replacing of bone graft and material of osteosynthesis gave positive results, many technical problems are present during the intervention because of the important cortical reaction and bone densification. In six cases, peroperative X Ray and histology did not give diagnosis.

Adolescent↗
PubMed1987

[Results of combined valvular and coronary surgery].

Between 1975 and 1984, 50 patients underwent cardiac valve replacement combined with coronary revascularization. All had heart failure (class II 28, class III 18, class IV 4), and only 39 complained of angina, including 12 who had previously experienced myocardial infarction; 32 aortic valves, 17 mitral valves and 1 mitral + 1 aortic valve were replaced, these operations being combined with 1 to 4 bypasses (mean: 1.3) per patient. The overall peri-operative mortality rate (i.e. before the 30th post-operative day) was 12 p. 100 (aortic valve 6.2 p. 100, mitral valve 23.5 p. 100), with a regular decrease since 1978. The overall incidence of peri-operative infarction was 6 p. 100 (2.4 p. 100 after 1978). After the peri-operative period 15 patients died, 8 of them of cardiac disease (6 of heart failure, 1 of myocardial infarction, 1 of embolic accident). All survivors were improved, with only 3 cases of heart failure and 1 case of residual angina during a mean follow-up period of 36.1 months (range: 6-120 months). In combined valvular and coronary surgery the mortality rate and the incidence of peri-operative infarction have gradually decreased as years went by, and they are now similar to those of valvular surgery alone. This decrease is due to the progress achieved in cardiac surgery, notably to optimal myocardial protection and maximal revascularization. This progress, together with technical improvements in anaesthesia and intensive care, has rendered combined surgery feasible with an acceptable operative risk and with such satisfactory long-term results that patients over 70 years of age can now be offered this type of treatment.

Aged↗