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Biomedical subjects

P Levy

Publications and source records attributed to P Levy.

At least 19 recordsLinked to original sources
PubMed2002

Novel dynamical effects and persistent memory in phase separated manganites.

The time dependent response of the magnetic and transport properties of Fe-doped phase separated (PS) manganite La(0.5)Ca(0.5)MnO3 is reported. The nontrivial coexistence of ferromagnetic (FM) and non-FM regions induces a slow dynamics which leads to time relaxation and cooling rate dependence within the PS regime. This dynamics influences physical properties drastically. On one hand, metalliclike behavior, assumed to be a fingerprint of percolation, can be also observed before the FM phase percolates as a result of dynamical contributions. On the other hand, two novel effects for the manganites are reported, namely, the rejuvenation of the resistivity after aging and a persistent memory of low magnetic fields (<1 T), imprinted in the amount of the FM phase.

Journal Article↗
PubMed2002

The cost of osteoporosis in men: the French situation.

The objective of this study was to estimate the annual direct medical costs of osteoporosis and osteoporotic fractures incurred by French men > or =50 years of age. Costs were assessed from a societal perspective for 1999 and expressed in Euros. An expert panel was consulted to identify fractures attributable to osteoporosis according to International Classification of Diseases (ICD)-10 codes. Available age- and gender-specific osteoporosis attribution probabilities (OAP) were used to derive the proportion of health-care utilization for fractures resulting from osteoporosis. Hospital and ambulatory care costs due to fractures were obtained from French databases. A total of 23,260 acute hospitalizations were found to be caused by osteoporosis, 52% of which are for hip fractures. Mean cost per stay varied widely according to the site of fracture, from 1300 (wrist fracture) to 5900 (hip fracture). Consequently, the total cost of acute hospitalization amounts to 97.6 million, with hip fractures accounting for 73.2% of the expenditures. Rehabilitation and convalescence costs were estimated to be 90.8 million, generating a total hospital cost of 188.4 million. The total outpatient costs were estimated to be 9.1 million. Thus, the total medical costs of male osteoporosis amount to 197.5 million. A sensitivity analysis was performed to test the robustness of this figure. We estimate the number of fractures by applying international incidence rates from the literature to the French male population aged > or =50 years, whereas the OAP and unit costs were kept constant. This approach yielded an estimate of 21,857 fractures, which is only 6% below the base case. When compared with values from other countries, our study results appear very conservative.

Aged↗
PubMed2002

Identification of quality of life concerns of patients with obstructive sleep apnoea at the time of initiation of continuous positive airway pressure: a discourse analysis.

BACKGROUND: Obstructive sleep apnoea syndrome (OSAS) is a common condition with multiple symptoms dominated by daytime somnolence. Thus many worries and concerns of patients remain hidden. Treatment by nasal continuous positive airway pressure (CPAP) can be imposing for the individual. An analysis of the freely expressed concerns of such patients is required. OBJECTIVE: To seek an in-depth analysis of how patients live with sleep apnoea by allowing them an open discourse and analysing the text of their statements. DESIGN: A trained psychologist conducted semi-directive interviews with patients attending a pulmonary rehabilitation and convalescent unit around the themes of sleep, health and treatment. An analysis of content and of discourse was carried out by textual analysis and by propositional analysis of discourse (PAD) with the aid of dedicated computer programs (Tropes, Sphinx Lexica). RESULTS: Thirty patients with severe sleep apnoea were interviewed of whom 15 were initiating treatment with CPAP. Patients spoke of abnormal fatigue (22 mentions) and somnolence (21 times). Many have problems with obesity (25 instances), snoring related problems (12). There were 30 mentions of depression with a relationship to alcohol and anti-depressives. Twenty six times the theme of nocturnal waking was raised. There were many instances of problems with CPAP (nasal mask and noise problems raised 21 times). Patients have problems with relationships and sex because of OSAS. Other concerns were loss of memory and fear of dying. CONCLUSION: In a non-directed conversation OSAS patients express concerns not revealed in the standard medical paradigm and such concerns should be addressed in assessing treatment or evaluating quality of life (QOL).

Adult↗
PubMed2001

Enteral compared with parenteral nutrition: a meta-analysis.

BACKGROUND: The difference in outcomes in patients is unclear when 2 types of enteral nutrition, ie, tube feeding and conventional oral diets with intravenous dextrose (standard care), are compared with parenteral nutrition. OBJECTIVE: We reviewed systematically and aggregated statistically the results of prospective randomized clinical trials (PRCTs) to examine the relations among the nutrition interventions, complications, and mortality rates. DESIGN: We conducted a MEDLINE search for PRCTs comparing the effects of enteral and parenteral nutrition in adults. Two different people abstracted data for the method and outcomes separately. We used fixed-effects meta-analysis technique to combine the relative risks (RRs) of the outcomes of infection, nutrition support complications, other complications, and mortality. RESULTS: Twenty-seven studies in 1828 patients met the study criteria. Aggregated results showed a significantly lower RR of infection with tube feeding (0.64; 95% CI: 0.54, 0.76) and standard care (0.77; 95% CI: 0.65, 0.91). A priori hypotheses showed a lower RR of infection with tube feeding than with parenteral nutrition, regardless of nutritional status, presence of cancer, year of study publication, or quality of the study method. In studies in which participants had high rates of protein-energy malnutrition, there was a significantly higher risk of mortality (3.0; 95% CI: 10.9, 8.56) and a trend toward a higher risk of infection with standard care than with parenteral nutrition (1.17; 95% CI: 0.88, 1.56). CONCLUSIONS: Tube feeding and standard care are associated with a lower risk of infection than is parenteral nutrition; however, mortality is higher and the risk of infection tends to be higher with standard care than with parenteral nutrition in malnourished populations.

Enteral Nutrition↗
PubMed2001

A general model of the effects of sleep medications on the risk and cost of motor vehicle accidents and its application to France.

BACKGROUND: Although various prescription drugs may be equally effective in promoting sleep, some may lead to substantial impairment in psychomotor functioning and an increased risk of motor vehicle accidents. OBJECTIVE: To develop a general model to evaluate the potential effects of sleep medications on motor vehicle accidents and costs, and apply the model to the French setting. METHODS: Impairment in driving performance, as evaluated by randomised controlled open-road studies using the standard deviation of a vehicle's lateral position (SDLP), a measure of weaving, was expressed in terms of equivalent blood alcohol (ethanol) concentration (BAC). Epidemiological data were then used to relate BAC to the excess risk of motor vehicle accidents. Although a non-impairing medication would not increase risk, a medication that produces mild impairment in driving performance (a change of 2.5 cm in SDLP, equivalent to 0.05% BAC) would increase motor vehicle accident risk by 25%. One that leads to moderate impairment (an SDLP change of 4.5 cm, equivalent to 0.08% BAC) would roughly double this risk, and a severely impairing medication (an SDLP change of 7 cm, equivalent to 0.12% BAC) would result in up to a 5-fold increase in motor vehicle accident risk. For application to the French setting, a hypothetical cohort of 100,000 adult drivers with insomnia was assumed to be treated for 14 days either with zaleplon 10 mg, a new sleep medication that has been shown not to significantly impair driving performance, or zopiclone 7.5 mg, which has been shown to cause moderate impairment. RESULTS: Compared with zaleplon, use of zopiclone over 14 days in France would be expected to result in 503 excess accidents per 100,000 drivers at an additional cost of 158 French francs (31 US dollars) per person (1996 values). CONCLUSIONS: Our model illustrates the extent to which non-impairing sleep medications could reduce the burden posed by motor vehicle accidents. Our model is designed to be general, and thus can serve as the basis for similar investigations.

Accidents, Traffic↗
PubMed2001

[Early implant treatment of a child with anhidrotic ectodermal dysplasia. Apropos of a case].

The purpose of this article is to report the clinical course and follow-up of a child with ectodermal dysplasia who was treated with implants surgery very early. Different possibilities for prosthetic restoration in the anodontic child are reviewed. Tolerance was excellent. Good cover of the implant was achieved at four years. We propose early implantation reconstruction surgery for these exceptional cases. A prospective multicentric study of this condition would be useful.

Anodontia↗
PubMed2000

Rapid and sensitive PCR detection of Vibrio penaeicida, the putative etiological agent of syndrome 93 in New Caledonia.

Experimental infections of Penaeus (Litopenaeus) stylirostris were performed with a Vibrio penaeicida strain (AM101) isolated in New Caledonia from Syndrome 93 diseased shrimp. Cumulative mortalities resulting from intramuscular injection or immersion of shrimp in bacterial suspensions demonstrated high virulence for this bacterial strain and suggested that V. penaeicida could be the etiological agent of Syndrome 93. The median lethal dose (LD50) for AM101 was 1.3 x 10(4) CFU (colony forming units) ml-1 by immersion and less than 5 CFU shrimp-1 by intramuscular challenge, with mortality outbreaks at 48 and 22 h after challenge, respectively. A polymerase chain reaction (PCR) detection assay using a primer set designed from the 16S ribosomal RNA gene of V. penaeicida was developed. It gave an expected amplicon of approximately 310 bp in ethidium bromide-stained agarose gels. The specificity of these primers was assessed with different Vibrio species. Furthermore, DNA extracted by the Chelex method could be used to detect fewer than 20 cultured Vibrio cells in sea-water or shrimp hemolymph by this assay. It appears to be a reliable screening method for detecting V. penaeicida in shrimp and from the aquatic environment.

Animals↗
PubMed2000

Pancreatic pseudocyst located in the liver: a case report and literature review.

Pancreatic pseudocyst in the liver is a rare complication of acute or chronic pancreatitis. However, its frequency seems to be increasing with modem imaging procedures. The authors report a case of pancreatic pseudocyst involving the left lobe of the liver that occurred in a patient who never showed clinical evidence of pancreatitis or pancreatic injury. Complete screening led to the discovery of alcoholic chronic pancreatitis. The pseudocyst was treated successfully by radiologic drainage. The pancreatic pseudocyst location and therapeutic approaches are discussed. A literature review uncovered 26 cases of hepatic pancreatic pseudocysts. Clinical presentation, imaging characteristics, and treatment of these cases are analyzed.

Drainage↗
PubMed2000

Characterization of pharyngeal resistance during sleep in a spectrum of sleep-disordered breathing.

Aims of the study were 1) to compare Hudgel's hyperbolic with Rohrer's polynomial model in describing the pressure-flow relationship, 2) to use this pressure-flow relationship to describe these resistances and to evaluate the effects of sleep stages on pharyngeal resistances, and 3) to compare these resistances to the pressure-to-flow ratio (DeltaP/V). We studied 12 patients: three with upper airway resistance syndrome (UARS), four with obstructive sleep hypopnea syndrome (OSHS), three with obstructive sleep apnea syndrome (OSAS), and two with simple snoring (SS). Transpharyngeal pressures were calculated between choanae and epiglottis. Flow was measured by use of a pneumotachometer. The pressure-flow relationship was established by using nonlinear regression and was appreciated by the Pearson's square (r(2)). Mean resistance at peak pressure (Rmax) was calculated according to the hyperbolic model during stable respiration. In 78% of the cases, the value of r(2) was greater when the hyperbolic model was used. We demonstrated that Rmax was in excellent agreement with P/V. UARS patients exhibited higher awake mean Rmax than normal subjects and other subgroups and a larger increase from wakefulness to slow-wave sleep than subjects with OSAS, OSHS, and SS. Analysis of breath-by-breath changes in Rmax was also a sensitive method to detect episodes of high resistance during sleep.

Adult↗