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Biomedical subjects

F Robin

Publications and source records attributed to F Robin.

At least 19 recordsLinked to original sources
PubMed2006

Pseudomonas aeruginosa and Pseudomonas putida outbreak associated with contaminated water outlets in an oncohaematology paediatric unit.

This paper describes an outbreak of Pseudomonas aeruginosa and Pseudomonas putida that occurred in an oncohaematology paediatric unit between January and April 2005. Eight children had nosocomial infections due to P. aeruginosa (N=5) or P. putida (N=3), which were recovered from central venous catheter blood cultures (N=4), the catheter exit site alone (N=2), or the catheter exit site and the catheter tip (N=2). Subsequent investigation showed that contaminated water outlets represented the possible source of spread. Studies of nursing and environmental cleaning practices revealed two modes of catheter contamination. A reduction in the size of the catheter dressing at the exit site gave less protective cover during showers, and a detergent-disinfectant diluted with tap water had contaminated perfusion bottles. Repetitive intergenic consensus polymerase chain reaction indicated two discrete patterns for P. aeruginosa and one for P. putida. The water network was chlorinated, and disposable seven-day filters were fitted on all taps and showers. Due to the deleterious effects of chlorination on the water network and the cost of the weekly filter change, a water loop producing microbiologically controlled water was installed. In addition, the concentration of the detergent-disinfectant was increased and refillable sprayers were replaced with ready-to-use detergent-disinfectant solution for high-risk areas. Following these measures, no Pseudomonas spp. have since been isolated in clinical or environmental samples from the ward.

Adolescent↗
PubMed2006

Outbreak of colonization and infection with vancomycin-resistant Enterococcus faecium in a French university hospital.

An outbreak of infection with vancomycin-resistant Enterococcus faecium occurred at Hotel-Dieu Hospital (Clermont-Ferrand, France). A case-control study was performed in the infectious diseases and hematology units of the hospital. Urinary catheter use (odds ratio [OR], 12 [95% confidence interval {CI}, 1.5-90]; P<.02), prior exposure to a third-generation cephalosporin (OR, 22 [95% CI, 3-152]; P=.002), and prior exposure to antianaerobials (OR, 11 [95% CI, 1.5-88]; P<.02) were independently predictive of vancomycin-resistant Enterococcus faecium carriage.

Disease Outbreaks↗
PubMed2006

Prediction of the evolution of ceftazidime resistance in extended-spectrum beta-lactamase CTX-M-9.

A random mutagenesis technique was used to predict the evolutionary potential of beta-lactamase CTX-M-9 toward the acquisition of improved catalytic activity against ceftazidime. Thirty CTX-M mutants were obtained during three rounds of mutagenesis. These mutants conferred 1- to 128-fold-higher MICs of ceftazidime than the parental enzyme CTX-M-9. The CTX-M mutants contained one to six amino acid substitutions. Mutants harbored the substitutions Asp240Gly and Pro167Ser, which were previously observed in clinical CTX-M enzymes. Additional substitutions, notably Arg164His, Asp179Gly, and Arg276Ser, were observed near the active site. The kinetic constants of the three most active mutants revealed two distinct ways of improving catalytic efficiency against ceftazidime. One enzyme had a 17-fold-higher k(cat) value than CTX-M-9 against ceftazidime. The other two had 75- to 300-fold-lower Km values than CTX-M-9 against ceftazidime. The current emergence of CTX-M beta-lactamases with improved activity against ceftazidime may therefore be the beginning of an evolutionary process which might subsequently generate a great diversity of CTX-M-type ceftazidimases.

Ceftazidime↗
PubMed2005

Mode-locked laser diode with an ultrafast integrated uni-traveling carrier saturable absorber.

A novel two-section integrated mode-locked laser diode (MLLD) with a separate ultrafast uni-traveling carrier (UTC) saturable absorber section and semiconductor optical amplifier gain section is demonstrated. The UTC absorber is composed of a thin p-InGaAsP absorbing layer and an intrinsic InGaAsP collecting layer. By confining the photoexcitation process to the thin highly doped absorbing layer, the diffusion-limited hole extraction process is greatly enhanced. The investigated MLLD produces 600 fs uncompressed optical pulses at a 42 GHz repetition rate.

Journal Article↗
PubMed2005

[VCA agar (bioMérieux) for selective isolation of vancomycin-resistant Enterococci (VRE) from fecal specimens].

Screening for Vancomycin Resistant Enterococci (VRE) is recommended for preventing nosocomial infections with VRE. The aim of this study was to assess the performance of VCA3 agar (bioMérieux) in VRE isolation from fecal specimens. 220 specimens were cultured on VCA3 agar, which contains vancomycin and in parallel, on CAP agar (Oxoid), which is vancomycin-free. 36 vancomycin resistant enterococci were isolated: 24 isolates of Enterococcus faecium expressed a high-level resistance to vancomycin and 12 isolates of E. gallinarum/casseliflavus exhibited resistance at low-level. The sensitivity of VCA3 appeared greater than that of CAP for VRE isolation: 92% (22/24) vs 79% (19/24) for E. faecium (NS, P>0.05) ; 83% (10/12) vs 50% (6/12) for E. gallinarum/casselliflavus (NS, P>0.05). As expected, initial cultures of multiple gram positive organisms were far more frequent on CAP agar than on VCA3 agar. The isolation rate of vancomycin susceptible gram positive strains was impressively lower on VCA3 medium than on CAP medium. VCA3 agar avoided therefore additional subcultures, useless identification and susceptibility tests. In conclusion, VCA3 medium could be useful for the direct, rapid and selective isolation of VRE from fecal specimens.

Cross Infection↗
PubMed2005

Unexpected enzyme TEM-126: role of mutation Asp179Glu.

The clinical isolate Escherichia coli CF884 exhibited low-level resistance to ceftazidime (4 mug/ml) by a positive double-disk synergy test and apparent susceptibility to cefuroxime, cefotaxime, cefepime, cefpirome, and aztreonam. The enzyme implicated in this phenotype was a novel 180-kb plasmid-encoded TEM-type extended-spectrum beta-lactamase designated TEM-126 which harbors the mutations Asp179Glu and Met182Thr. TEM-126 exhibited significant hydrolytic activity (k(cat), 2 s(-1)) and a K(m) value of 82 muM against ceftazidime. Molecular dynamics simulations suggested that the substitution Asp179Glu induces subtle conformational changes to the omega loop which may favor the insertion of ceftazidime in the binding site and the correct positioning of the crucial residue Glu166. Overall, these results highlight the remarkable plasticity of TEM enzymes, which can expand their activity against ceftazidime by the addition of one carbon atom in the side chain of residue 179.

Amino Acid Sequence↗
PubMed2005

TEM-109 (CMT-5), a natural complex mutant of TEM-1 beta-lactamase combining the amino acid substitutions of TEM-6 and TEM-33 (IRT-5).

Escherichia coli CF349 exhibited a complex beta-lactam resistance phenotype, including resistance to amoxicillin and ticarcillin alone and in combination with clavulanate and to some extended-spectrum cephalosporins. The double-disk synergy test was positive. CF349 harbored an 85-kb conjugative plasmid which encoded a beta-lactamase of pI 5.9. The corresponding bla gene was identified by PCR and sequencing as a bla(TEM) gene. The deduced protein sequence revealed a new complex mutant of TEM-1 beta-lactamase designated TEM-109 (CMT-5). TEM-109 contained both the substitutions Glu104Lys and Arg164His of the expanded-spectrum beta-lactamase (ESBL) TEM-6 and Met69Leu of the inhibitor-resistant TEM-33 (IRT-5). TEM-109 exhibited hydrolytic activity against ceftazidime similar to that of TEM-6 (k(cat), 56 s(-1) and 105 s(-1), respectively; K(m) values, 226 and 247 microM, respectively). The 50% inhibitory concentrations of clavulanate and tazobactam (0.13 microM and 0.27 microM, respectively) were 5- to 10-fold higher for TEM-109 than for TEM-6 (0.01 and 0.06 microM, respectively) but were almost 10-fold lower than those for TEM-33. The characterization of this novel CMT, which exhibits a low level of resistance to inhibitors, highlights the emergence of this new ESBL type.

Amino Acid Substitution↗
PubMed2005

[Contribution of the French Armed Forces Health Services to relief in Indonesia following the tsunami on December 26, 2004].

As of early January 2005, the French Armed Forces Health Services were on the ground in Indonesia to contribute to relief operations following the tsunami in Indonesia on December 26, 2004. Findings of preliminary investigation performed upon deployment of the first French elements demonstrated that a major priority was to speed up vaccination against measles in children between the ages of 6 months and 15 years. A vaccination campaign was planned in cooperation with Indonesian authorities and UNICEF. Implementation involved training of personnel and setting up vaccination clinics in refugee camps, schools, and neighborhoods in the city of Meulaboh. The vaccination campaign was hampered by a number of problems in particular involving logistics and required constant supervision. A survey to evaluate the results of the campaign in terms of vaccination coverage showed that the objective of vaccinating 70% of children in refugee camps was achieved. The survey provided other child health indicators that will be helpful to local authorities taking over after the departure of the French Armed Forces Health Services.

Adolescent↗
PubMed2004

Stage I ovarian cancer: comparison of laparoscopy and laparotomy on staging and survival.

OBJECTIVE: The aim of this study was to compare staging accurateness as well as survival when managing early ovarian cancers by laparoscopy or laparotomy. MATERIAL AND METHODS: We have conducted a retrospective and multicentric study in France. Only Stage I ovarian epithelial cancers operated on from January 1, 1985 to December 31, 1999 were taken into account. Respondents had to fill in a form detailing in each case the surgical access; the surgical acts performed during the initial intervention as well as data on the patient's follow-up. Lack of follow-up or final Stage > I were considered as exclusion criteria. Data were recorded and analysed with SPSS 7.5 and STATA (Stata statistical sofware 7.0). (ANOVA, chi-square test or Fisher's exact test and log-rank test). RESULTS: 105 cases were included: 14 patients were exclusively operated on by laparoscopy (group 1), 13 other patients were subjected to a conversion from laparoscopy to laparotomy (group 2) and 78 patients exclusively underwent laparotomy (group 3). Patients in group 3 were significantly more frequently postmenopausal and had larger lesions. Cyst rupture was rare during laparoscopy (21%) and the use of an endobag was achieved in only 21% of the patients in group 1. Radical treatment was significantly more frequent in group 3 when compared to group 1 (67% vs 23%, p < 0.05). Laparoscopy was not adequate for staging since no lymphadenectomy was carried out by this approach. However, only 27% of patients subjected to an open approach underwent lymphadenectomy and omentectomy. The outcome in terms of survival was similar in the three groups with a mean follow-up period of 1,221 days (+/- 832) (p = 0.1). CONCLUSION: Laparoscopic management of early ovarian cancer is poorly efficient in staging although disease-free survival does not seem to be affected. Further evaluation of laparoscopy in this indication is needed.

Adult↗
PubMed2002

Impact of pneumoperitoneum on tumor growth.

AIM OF THE STUDY: To compare intraperitoneal tumor growth after CO2 laparoscopy (L), gasless laparoscopy (GL), midline laparotomy (ML), and general anesthesia (GA) as a control. MATERIALS AND METHODS: A prospective randomized trial was carried out in nude rats. A carcinomatosis was obtained by intraperitoneal injection of either one of the two human ovarian cancer cell lines IGR-OV1 or NIH:OVCAR-3. Rats secondly underwent randomly different kind of procedures: CO2 L (8 mmHg, 60 min), GL (traction by a balloon for 60 min), ML (bowel removed and let on a mesh for 60 min), or GA. The rats were finally killed 10 or 35 days after surgery (respectively in IGR-OV1, or NIH:OVCAR-3 models). Tumor growth was assessed by the weight of the omental metastasis and MIB1 immunostaining. Peritoneal dissemination as well as abdominal wall metastases were assessed by pathological examination. Statistical analysis used the chi-square test (or Fisher exact test) and Bonferroni method for multiple comparison between groups. RESULTS: Fifteen rats were included in each group. Mean omental weight was significantly increased after surgery (3.1 to 5.6 g), when compared to control (2.4 g), but no significant difference was recorded between the three surgical accesses. MIB1 immunostaining was poor in the PNP group (37%), whereas it was higher after midline laparotomy (51%), but the difference was not significant (p = 0.07). Similarly, no significant variation was recorded in the NIH:OVCAR-3 model for omental weight or MIB1 staining. CO2 pneumoperitoneum significantly increased right diaphragmatic dome involvement in the NIH:OVCAR-3 model. Abdominal wall metastases were significantly more frequent after surgery when compared to the control group, but no significant difference could be demonstrated between surgical groups in each model. CONCLUSION: In these solid tumor models, CO2 pneumoperitoneum had no deleterious effect on tumor growth when compared to gasless laparoscopy or midline laparotomy.

Animals↗
PubMed2002

Female pseudohermaphroditism in a fetus with a deletion 9(q22.2q31.1).

Interstitial deletions of chromosomal region 9q are rarely seen. We report the first prenatal diagnosis of a de novo interstitial deletion 9q. The fetus was karyotyped for intrauterine growth retardation (IUGR). Conventional and molecular cytogenetics showed female karyotype with a de novo deletion of the chromosomal region 9(q22.2q31.1) leading to a partial monosomy 9q. At autopsy, the fetus showed growth retardation, dysmorphy, and a female pseudohermaphroditism. These results suggest that a gene(s) for genital development reside in chromosomal region 9q22.2q31.1.

Adult↗
PubMed2001

Impact of different gases and pneumoperitoneum pressures on tumor growth during laparoscopy in a rat model.

BACKGROUND: The influence on intraperitoneal tumor growth of the choice of gas and pneumoperitoneum pressure during laparoscopy is still unknown. This study compared tumor growth after laparoscopy with different gases and pneumoperitoneum pressures in an immunodeficient model. METHODS: In an initial experiment, 60 nude rats were randomly allocated to undergo laparoscopy at different pneumoperitoneum pressures (gasless, 4 mmHg, or 8 mm Hg.) In a second experiment, 23 nude rats were randomly allocated to undergo laparoscopy with different gases (carbon dioxide or helium). Surgery was carried out 7 days after intraperitoneal injection of IGR-OV1 cells. The rats were killed 7 days after surgery. Tumor growth was assessed by the weight of the omental metastasis. For statistical analysis, we used analysis of variance (ANOVA). RESULTS: Mean omental weight was similar for all groups, regardless of the pneumoperitoneum pressure (p = 0.86) or the type of gas (p = 0.80). CONCLUSION: Physical parameters of gas have a limited impact on tumor growth.

Animals↗
PubMed2001

Peritoneal closure reduces port site metastases: results of an experiment in a rat ovarian cancer model.

BACKGROUND: The arm of this study was to assess the role of peritoneal closure in the prevention of port site metastasis after carbon dioxide (CO2) CO2 pneumoperitoneum. METHODS: We developed a xenograft ovarian cancer model by intraperitoneal injection of 27 106 IGR-OV1 line cells in nude rats Seven days after the inoculation, the animals underwent a CO2 pneumoperitoneum. At the end of the procedure, port sites were randomly closed either with suture of peritoneum (n = 14, group A) or without suture of peritoneum (n = 12, group B). The rats were killed 7 days after surgery and their port site scars were resected. Tumor implantation was assessed by a pathologist who was blinded to the type of wound closure. RESULTS: The animals in group B were significantly more likely to have at least one port site metastasis frequent (seven of 12, or 58.3%) than those in group A (two of 14, or (14.3%) (p = 0.037). Port sites with metastases were seen more frequently in group B (eight of 24, or (33.3%) than in group A (three of 28, or 10.7%) (p = 0.046). CONCLUSIONS: Our results shows that peritoneum closure decreases the risk of port site metastasis.

Animals↗
PubMed2001

Saline contrast sonohysterography in the preoperative assessment of benign intrauterine disorders.

OBJECTIVES: To assess the value of saline contrast sonohysterography (SCSH) in the preoperative evaluation of benign intrauterine lesions. DESIGN: Patients presenting with abnormal bleeding related to benign uterine pathologies and scheduled for surgical treatment were prospectively enrolled in a study conducted between 1 January 1996 and 31 December 1997. SCSH was first carried out with the intention of establishing further surgical management (hysterectomy or hysteroscopy). The end point of the study was to compare the surgical option ultimately carried out with the one decided after SCSH. In addition, size and location of intrauterine lesions determined by SCSH were compared with those issued from surgical records. Similarly, pathologic results were juxtaposed to SCSH diagnosis. Statistical analysis used non-parametric and correlation tests. RESULTS: Two hundred and thirty-three patients were included in the study, 39.5% of whom were postmenopausal. SCSH was consistently effective in the choice of the best surgical method, because no hysterectomy was required when an operative hysteroscopy was indicated on SCSH data. Similarly, only one patient treated by hysterectomy (5.8%) could have undergone a more conservative approach. But this patient had a genital prolapse, and thus hysterectomy was a part of the treatment. SCSH correlated well with surgery for the location and size of intrauterine lesions (P < 0.001). SCSH was accurate in the diagnosis of polyps and submucous myomas (sensitivity 85.7%, specificity 95.4%). CONCLUSIONS: SCSH appears an important tool for preoperative assessment of benign intrauterine pathologies. It should be used in the selection of patients that should be scheduled for an operative hysteroscopy.

Female↗
PubMed2001

Impact of pneumoperitoneum on visceral metastasis rate and survival. Results in two ovarian cancer models in rats.

OBJECTIVE: To compare the impact of CO2 laparoscopy, gasless laparoscopy, and midline laparotomy on the development of distant metastases and on survival in two ovarian carcinoma models. DESIGN: A prospective randomised study in rats. MATERIAL: and methods Two ovarian cancer xenografts were obtained by intraperitoneal injection of IGR-OV1 or NIH-OVCAR-3 cells. Experimental surgical procedures were performed on day 7 (IGR-OVI model) or day 14 (NIH: OVCAR-3 model) after intraperitoneal injection: CO2 laparoscopy (pneumoperitoneum (PNP) with unheated CO2 at a pressure of 8 mmHg for 1 hour); gasless laparoscopy (consisting in abdominal wall expansion by a balloon for 1 hour); midline laparoscopy (consisting in bowel exteriorisation on a mesh for one hour following xyphopubic laparotomy). The control group underwent general anaesthesia alone. The animals were killed by CO2 inhalation as soon as they became moribund. MAIN OUTCOME MEASURES: Pathological examination was carried out on the liver, lungs and pleura as well as the retroperitoneal nodes. Survival was determined from the time of surgery to the sacrifice of the animal. Statistical analysis used ANOVA, Fisher exact test, Bonferonni method and the log-rank test. RESULTS: In the IGR-OV1 model, distant metastases were rare, and were not promoted by CO2 laparoscopy. With the NIH: OVCAR-3 model, pleural, pulmonary and para-aortic metastases were not enhanced by CO2 PNP when compared with other approaches. Conversely, midline laparotomy and laparoscopy significantly increased liver involvement when compared with gasless laparoscopy (P = 0.04 and P = 0.008). Survival was comparable no matter what kind of surgery had been performed in the IGR-OV1 model (P = 0.7) or in the NIH: OVCAR-3 model (P = 0.5). CONCLUSIONS: CO2 laparoscopy had a minor impact on distant and nodal metastases in the two models. Similarly, survival was similar for all surgical groups.

Animals↗
PubMed2001

Influence of peritoneal factors on port-site metastases in a xenograft ovarian cancer model.

OBJECTIVE: We determine the main physical effects of pneumoperitoneum on tumour dissemination and port-site metastases occurrence. DESIGN: A prospective randomised study in rats. METHODS: A human ovarian cancer cell line (IGR-OV1) was xenografted in nude rats. Seven days after cancer inoculation, surgery was performed. Rats were randomised in two main groups and underwent either: gasless laparoscopy (n = 20) CO2 laparoscopy with pneumoperitoneum pressure at 4 mmHg (n = 20), or 8 mmHg (n = 20) with in each case, increasing operative duration: 30,60,90 or 120 minutes (five rats for each time). Animals were killed seven days after the intervention. MAIN OUTCOME MEASURES: Tumour dissemination and frequency of port-site metastases. RESULTS: Tumour dissemination was not influenced by gas pressures or duration of procedure. The rate of rats with at least one port-site metastasis (one or two) was similar in all groups: gasless: n = 10/20; 4 mmHg CO2: 5/20; 8 mmHg CO2: 7/20,(P = 0.26). The number of port-site metastases were significantly higher in the gasless group compared with the 4 mmHg CO2 group (15/40 (37.5%) vs 5/40 (12.5%), P = 0.01). Difference was not significant between the 8mmHg group and the gasless group (9/40(22.5%) vs 15/40(37.5%), P = 0.14) or the 4mmHg group (9/40(37.5%) vs 5/40 (12.5%), P = 0.24). Duration of procedures had no significant influence on port-site metastases rate (P > 0.05). CONCLUSIONS: Unlike previous animal studies, port-site metastases were more frequent with gasless laparoscopy than with CO2 pneumoperitoneum. Local peritoneal factors could play an important role in port-site metastases mechanism.

Animals↗
PubMed2000

Direct cost of single dose methotrexate for unruptured ectopic pregnancy. Prospective comparison with laparoscopy.

OBJECTIVES: to compare the direct cost of single dose methotrexate (MTX) and laparoscopy in the treatment of unruptured ectopic pregnancy (unruptured EP). STUDY DESIGN: A prospective nonrandomized study. Thirty-two women received intramuscular MTX (1 mg/kg) on an out-patient basis when they fulfilled the following requirements: human chorionic gonadotropin (hCG) level <5000 IU/l, hematosalpinx diameter <3 cm and peritoneal fluid <100 cc. Follow-up consisted of clinical controls and hCG assays. Twenty-seven women eligible for MTX therapy according to the above conditions underwent laparoscopic salpingectomy because some of them refused the therapy while others had contraindications to MTX. We recorded all the medical expenses related to the out-patient and in-patient management for the two treatment options. The cost was calculated according to the French General Nomenclature of Professional Acts and expressed in Euros. RESULTS: MTX resulted in a significantly lower mean direct cost in comparison with surgery (E 1145 vs. 2442, P=0.006) that was mainly due to shortened hospital stay (1.1 vs. 2.8 days, P=0.007). Conversely MTX required a significantly higher number of medical acts during the follow-up. Costs for MTX therapy were closely related to the length of hospitalization and to the duration of the follow-up. CONCLUSION: Single dose MTX provides significant cost-savings when compared to laparoscopy. Savings reach a peak for small unruptured EP because hospitalization is not required and the length of follow-up reduced.

Abortifacient Agents, Nonsteroidal↗