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Biomedical subjects

C Robert

Publications and source records attributed to C Robert.

158 records · Page 9Linked to original sources
PubMedDate not supplied

Metalloproteinases and tumor necrosis factor-alpha activities in synovial fluids of horses: correlation with articular cartilage alterations.

Early detection of osteoarthritis in horses represents a challenge for equine practitioners. Several biological markers have been implicated in the pathological processes involved in articular cartilage destruction. To further document cartilage matrix proteases production, synovial fluid was collected from 14 horses (90 joints) before they were subjected to euthanasia. Growth macroscopic examination of the joints gave information on cartilage alterations. Samples were analyzed for matrix metalloproteinase (MMPs) activities by gelatin zymography and tumor necrosis factor alpha (TNF-alpha) cytotoxicity using L929 cells. Significant increase of MMP-9 monomer and dimer were found in synovial fluids of joints with severe cartilage alterations. On the contrary, the activity of TNF-alpha was not correlated to the degree of joint damage. The levels of MMP-9 monomer and dimer in the synovial fluid could reflect cartilage alteration in arthritis in the horse.

Animals↗
PubMedDate not supplied

Bacterial removal from inexpensive portable water treatment systems for travelers.

BACKGROUND: There are many personal portable water treatment systems for travelers on the market, including chemical agents, iodine resin purifiers and filters. However, information on the real efficacy of these systems in the field is often lacking. We have therefore estimated the capabilities of several inexpensive personal portable water treatment systems for travelers to remove bacteria in various situations of water quality, using stressed indigenous strains of bacteria. METHODS: Four chemical agents (Drinkwell chlorine, Hydroclonazone, Aquatabs, 2% iodine in ethanol), two iodine resin purifiers (the straw PentaPure Outdoor M1-E, the PentaPure Traveler purifying and filtration system) and four filters (the flexible bottle Pres2Pure, the hand-pump filters Mini Ceramic, First Need Deluxe and WalkAbout) were evaluated in triplicate using both turbid and clear water at 25 degrees C. Bacteria were counted by conventional culturing techniques, colorimetric and fluorescent assays of coliforms and Escherichia coli enzyme activities (Colilert)/Quantitray method), and viable but not culturable bacteria were assessed quantitatively by 5-cyano-2,3-dilotyl-tetrazolium staining. RESULTS: The best systems were the three hand-pump filters, Mini Ceramic, First Need Deluxe, and WalkAbout. All had a submicron filtration element that completely removed 3 log (99.9%) or more of viable bacteria, and no coliforms or E. coli were detected in the effluent. The PentaPure Traveler removed more than 99.3% of the viable bacteria. The only chemical agents that gave a bacterial inactivation of over 2 log in clear water were the Drinkwell chlorine, the Aquatabs, and the 2% iodine in ethanol. The three other devices, Hydroclonazone, Outdoor M1-E, and Pres2Pure, performed poorly, as coliforms and E. coli were detected in the treated water by the Colilert method. The chemical agents and the iodine resin straw performed poorly on raw river water; coliforms and E. coli were detected in the treated water. CONCLUSIONS: These data demonstrate the differences between the systems tested. The effectiveness of other devices on the market should also be tested, so as to help travelers and hikers select the most appropriate portable water treatment system.

Bacteria↗
PubMedDate not supplied

Variables processing in expert system building: application to the aetiological diagnosis of infantile meningitis.

We describe a method for the analysis and quantitative synthesis of information in a clinical data file using as an example the aetiological diagnosis of infantile meningitis. The results obtained together with the qualitative knowledge of experts in the field have enabled an experimental system to be constructed. This is performing sufficiently well to be introduced into a hospital environment to assist young doctors facing an emergency situation.

Acute Disease↗
PubMedDate not supplied

Outpatient satisfaction: validation of a French-language questionnaire: data quality and identification of associated factors.

OBJECTIVES: Following 1996 legislation requiring French hospitals to assess patient satisfaction, this study developed and validated a brief French-language multidimensional questionnaire designed to measure outpatient satisfaction with hospital visits and compared data quality for two patient-satisfaction survey methods. DESIGN: Authors developed a 19-item questionnaire following a strict procedure (identification of dimensions to explore, formulation, and selection of items). SETTING: Validation data were obtained from patients of six outpatient clinics in a teaching hospital. PARTICIPANTS: 586 consenting eligible patients were randomized to receive the questionnaire 2 weeks after their visit with one of two survey methods: a mailed self-administered questionnaire or a telephone interview. RESULTS: The response rate (79%) was not significantly different between the two survey methods. The risk of having one or more missing values was higher in the mail survey group (odds ratio, 1.65; 95% confidence interval, 1.03-2.63), but mail respondents were less likely to use the "extremely positive" response category. Principal component analysis identified four factors that accounted for 56% of the variance: interpersonal skills and information transfer, physical surroundings, convenience, and appointment delay. Patients' comments on open-ended questions validated the semantic content of the factorial construct. The internal consistency coefficient was greater than 0.70 for three of four subscales. Patient background characteristics accounted for less than 10% of the factorial score variance. Patient satisfaction was correlated with age, type of visit, and, to a lesser extent, gender and education level. CONCLUSION: This easily administered, multidimensional out-patient-satisfaction questionnaire provided encouraging preliminary psychometric characteristics.

Adolescent↗
PubMedDate not supplied

An in vivo method to assess the photostability of UV filters in a sunscreen.

An in vivo method was developed in order to study the photostability of UV filters in a sunscreen. This method assesses sunscreen photostability in the emulsion after direct interaction with the skin. For this purpose UV filters were recovered from volunteers' forearms by using the stripping technique, then extracted from tapes and quantified by high-performance liquid chromatography (HPLC). The photostability of the filters tested was evaluated by comparing the amount of filters recovered from the strippings of UV-irradiated skin (40 minimal erythema dose, or MED) versus non-irradiated skin. Sequential analysis of several successive tapes reflected the distribution profile of the filters in the stratum corneum. Photochemical change was observed for one filter: it was shown to undergo a photochemical modification with the appearance of an additional HPLC peak. Moreover, UV filters tested displayed a high affinity for the stratum corneum but presented different distribution profiles. This in vivo method takes into account the interaction of the sunscreen agents with the stratum corneum. Furthermore, unlike spectrometric methods usually used for photostability assessment, it gives quantitative data for each individual filter of a finished product by using an HPLC technique.

Adult↗
PubMedDate not supplied

A double-blind evaluation of the activity of an anti-cellulite product containing retinol, caffeine, and ruscogenine by a combination of several non-invasive methods.

A double-blind, randomized, placebo-controlled study was conducted with 46 healthy female volunteers in order to test an anti-cellulite product containing retinol, caffeine and ruscogenine. An evaluation of different parameters related to cellulite appearance, i.e., the skin macrorelief, the dermal and hypodermal structures, the skin mechanical characteristics, and the cutaneous flowmetry was assessed using several non-invasive methods. This combination of different evaluation methods resulted in the demonstration of significant activity of the anti-cellulite product versus baseline and showed its superiority versus the placebo in skin macrorelief (decrease of the "orange peel" effect) and an increase in cutaneous microcirculation. By using a combination of methods, it was possible to detail the activity of an anti-cellulite product and to show superiority of the product in comparison with the placebo.

Adipose Tissue↗
PubMedDate not supplied

Detection of antibodies to human herpesvirus-6 using immunofluorescence assay.

A serological study of human herpesvirus-6 (HHV-6) infection was performed by means of immunofluorescence assay on fixed HHV-6-infected cells. Comparison between indirect immunofluorescence assay (IFA) and anticomplement immunofluorescence assay (ACIF) showed that the latter test was the most appropriate for HHV-6 serology, although both methods exhibited identical sensitivity. ACIF, which was performed on HSB2 cells infected with the HBLV strain (provided by S.Z. Salahuddin), was then used to determine the titre of HHV-6 antibodies in serum by end-point dilution. The sera from 115 healthy subjects and 99 patients with presumed viral infection were tested. A similar distribution of HHV-6 titres was evidenced in both cases and the rate of individuals exhibiting a positive titre of 20 and above was about 30% of the whole population studied. No serological cross-reactivity was observed between HHV-6 and other herpesviruses, suggesting that the HHV-6 ACIF test was quite specific.

Adult↗
PubMedDate not supplied

[Human herpesvirus-6 infection and hepatitis following heart transplantation].

OBJECTIVES: Human Herpesvirus-6 (HHV-6) has been implicated in hepatitis and HHV-6 infections have been reported in patients receiving heart transplants. We investigated the occurrence of such infections and their possible relation with post-transplantation hepatitis in 58 heart transplanted patients. METHODS: The titre of HHV-6 antibodies was determined by anticomplement immunofluorescence assay and compared with the titre of CMV antibodies determined by using ELISA. RESULTS: HHV-6 seroprevalence after transplantation did not differ significantly between hepatitis, control patients (without hepatitis) and the healthy general population. In three controls and five hepatitis patients we observed, after transplantation, a seroconversion or a significant increase of antibody titre which suggested active HHV-6 infection. In six cases, HHV-6-specific IgM were found whereas CMV-specific IgM were not detected. CONCLUSION: These results indicate that HHV-6 infection is frequent after heart transplantation but not in relation with hepatitis. The mechanism of this infection needs to be clarified (either primo-infection or reactivation) and the question remains whether this infection is totally asymptomatic or could induce serious illness.

Antibodies, Viral↗