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Biomedical subjects

P Renaud

Publications and source records attributed to P Renaud.

34 records · Page 2Linked to original sources
PubMed1997

The stress of Stroop performance: physiological and emotional responses to color-word interference, task pacing, and pacing speed.

Heart rate, frequency of skin conductance responses, and self-reported anxiety were measured during performance of a computer version of the Stroop Color-Word Interference Test, and during a non-conflicting control task involving the color naming of color patches. Stroop and control stimuli were presented individually in order to vary task pacing. Subjects (N = 48) were divided into three groups assigned to self-paced, externally-paced, and fast externally-paced conditions. Performance data revealed that the relative proportion of speed and accuracy reductions which resulted from the Stroop interference varied according to task pacing and pacing speed. Stroop performance was accompanied by heightened HR levels which were sustained throughout the series. State-Anxiety scores increased after both tasks, but only among subjects who completed a large number of trials, i.e. subjects in the self-paced and fast externally-paced groups. Skin conductance responses only varied according to task order and time within series, irrespective of Stroop interference or task pacing. Overall, the results remained in accordance with an effort account of the relationship between attention and cardiac activity. They also provided indications on how the Stroop test may act as an efficient laboratory stressor.

Adolescent↗
PubMed1996

A 5-year (1990-1994) neuroblastoma screening feasibility study in France. Methodology and preliminary observations.

INTRODUCTION: Following the pioneering Japanese experience, several European and North American groups implemented pilot studies on screening infants for neuroblastoma, considering the possibility of demonstrating a decrease in mortality rate. In France, a 5-year (1990-1994) feasibility study on neuroblastoma screening at the age of 4 months was initiated in the Rhône district (1.5 M inhabitants, 26,000 births per year). METHODS: Vanillylmandelic (VMA) and homovanillic (HVA) acids were measured by HPLC, and creatinine (Cr) by the Jaffé's kinetic method on Technicon RA-XT. VMA and HVA were expressed as microgram/mg of Cr. The method was assessed with both a daily intra-laboratory control and a sample of urine obtained from a national quality control organism. RESULTS AND DISCUSSION: The overall participation rate for the 5-year period was 82.2%. Out of 105,293 infants tested from 128,126 births, 12 NB cases were discovered with screening (screened cases) and 1 case was discovered with a late performed test (at 13 months of age). Six neuroblastomas were found clinically before the age of 4 m. Two cases were missed because the parents did not perform the test. Three children with normal tests at screening were false-negative cases: two of them were found secreting at diagnosis, while one remained non-secretory at diagnosis and later on. Otherwise, thirty-five false-positive tests were found. Biochemical observations are discussed. It is too early to reach clinical conclusions from this screening program on neuroblastomas as it is presently being followed up.

Chromatography, High Pressure Liquid↗
PubMed1994

Treatment of port-wine stains with the 585-nm flashlamp-pulsed tunable dye laser: a study of 74 patients.

Over 20 months, we have treated 74 patients (59 children less than 12 years of age) with port-wine stains (PWS) using a 585-nm flashlamp-pulsed dye laser (SPTL-1, Candela Corp., Wayland, Mass., USA) after topical anesthesia with Emla cream. A 5-point reference color scale was used to evaluate the results. 45 patients had at least one treatment on the entire surface of the lesion. A mean of 88 impacts per session was delivered. There was a significant decrease in color in around two thirds of the cases after one complete treatment with a gradual tendency to improvement after subsequent treatments. Younger age at the beginning of treatment was not found to be predictive of a better outcome after the first treatment. In around one third of the cases, positive test site treatment was not correlated with significant improvement after one treatment. Lesions situated on the limbs were less responsive than those on the head and neck. Except for problems due to absence of general anesthesia in young children enduring repeated stressful and sometimes painful procedures, the overall impression is that early treatment of PWS is possible with very limited risks of scarring using this technique.

Adolescent↗
PubMed1991

[Linear porokeratosis of Mibelli in monozygotic twin girls].

Two monozygotic female twins with linear porokeratosis of Mibelli are described. One had only minimal lesions of the right elbow. The other had a linear lesion of the right arm following Blaschko's lines. Monozygotism was established using DNA fingerprinting. A single-gene defect of variable expressivity involving the clonal development of epidermal cutaneous cells according to the lines of cutaneous embryogenesis is suspected. Dithranol and carbon dioxide laser treatment are discussed.

Anthralin↗
PubMed1990

Cisplatin-induced anemia: a potential interference with iron metabolism at erythroid progenitors level.

To elucidate the potential mechanisms of anemia induced by cisplatin (CDDP) we have evaluated hemolysis, dyserythropoiesis, ferrokinetics and cytotoxicity on erythroid progenitors in 12 patients treated by a CDDP-containing combination chemotherapy and in 6 patients treated by a similar combination but without CDDP. Eight patients, from the CDDP treated group, experienced a pronounced anemia. None had signs of hemolysis. Ferrokinetic study showed a very deep and protracted decrease of 59Fe incorporation during the chemotherapy cycle and the following 2 weeks. These results, along with a normal medullary erythroblastic cellularity, suggest that CDDP induces a deep but transient erythropoiesis alteration leading to anemia in some cases.

Adult↗
PubMed1989

[Cephalhematoma infection in neonatal septicemia].

Most cephalhematomas resorb spontaneously; intervention by means of needle aspiration may introduce infection. In our case, a neonatal septicemia was associated with a large parietal cephalhematoma. The newborn was discharged after treatment of sepsis. Three days later, the diagnosis of infected cephalhematoma was apparent, associated with meningitis and septicemia. The authors discuss the physiopathology of the infection, antimicrobial therapy and careful aspiration when a serious infection is associated with cephalhematoma.

Cerebral Hemorrhage↗
PubMed1987

Management of insecticide resistance in control of the Simulium damnosum complex by the Onchocerciasis Control Programme, West Africa: potential use of negative correlation between organophosphate resistance and pyrethroid susceptibility.

1. Resistance of some populations of the Simulium damnosum complex to temephos (100-fold at the LC50 level), with degrees of cross-resistance to chlorphoxim (14-fold) and other organophosphate insecticides, follows intensive larvicidal control of S. damnosum s.l. in West African river systems since 1975 by the WHO Onchocerciasis Control Programme. 2. Larvae of at least three sibling species of the S. damnosum complex have become organophosphate-resistant: these are the forest species S. sanctipauli Vajime & Dunbar and the savanna species S. sirbanum V. & D. and S. damnosum Theobald sensu stricto. 3. Organophosphate-resistant S. damnosum s.l. larvae show increased susceptibility to some organochlorine and pyrethroid insecticides, especially to permethrin (up to 11-fold) and OMS 3002 (up to 17-fold), as compared with organophosphate-susceptible populations. 4. This differential susceptibility is reflected by increased pyrethroid efficacy in operational use for river treatments against organophosphate-resistant field populations of S. damnosum s.l. larvae. Treatment of 100 km of the lower Bandama River in 1985 showed that permethrin at the highly selective dosage of 10 min exposure to 0.01 mg/l caused reversion towards organophosphate-susceptibility of the target population of S. sanctipauli. This effect was less pronounced when the Comoe River was treated at the lower dosage of 0.005 mg/l for 10 min. 5. To overcome temephos-resistance, it is proposed that the most rational usage of currently available larvicides would involve the following annual sequence of treatments: Bacillus thuringiensis serotype H-14 when river discharge is below 75 m3/s; chlorphoxim for about eight weekly treatment cycles after river discharge rises; permethrin (or alternative pyrethroid) for up to six treatment cycles--this should eliminate any incipient selection for chlorphoxim-resistance; resume chlorphoxim (or perhaps carbosulfan) treatments until river discharge falls below 75 m3/s permitting resumed use of B.t. H-14.

Africa, Western↗
PubMed1987

Evaluation of larvicides for the control of Simulium damnosum s.l. (Diptera: Simuliidae) in West Africa.

The Onchocerciasis Control Program of the World Health Organization is carrying out an extensive screening program in a search for new larvicides to be used for control of Simulium damnosum s.l. Emphasis has been given to finding a pyrethroid and a carbamate to supplement the organophosphates currently in use. These chemicals with differing modes of action, together with Bacillus thuringiensis H-14, are being used in an attempt to cope with the development and spread of resistance to the organophosphates temephos and chlorphoxim.

Africa, Western↗