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C Lacroix

Publications and source records attributed to C Lacroix.

At least 55 records · Page 3Linked to original sources
PubMed2002

[Methemoglobinemia induced by repeated abuse of lidocaine viscous gel].

Lidocaine use may lead to methemoglobinemia. Lidocaine is clinically widely used as an anaesthesic drug, however its toxic effect is rare. We report a high methemoglobinemia level of 31.1% following repeated Xylocaine gel oral applications. New metabolic pathways of lidocaine have been reported leading to dimethylphenylhydroxylamine in humans. This metabolism is very similar to the aniline derivative ones, and may explain lidocaine methemoglobinemia effect.

Adult↗
PubMed2001

Physicians Taking Action Against Smoking: an intervention program to optimize smoking cessation counselling by Montreal general practitioners.

In 1997 the Direction de la santé publique de Montréal-Centre initiated "Physicians Taking Action Against Smoking," a 5-year intervention program to improve the smoking cessation counselling practices of general practitioners (GPs) in Montreal. Program development was guided by the precede-proceed model. This model advocates identifying factors influencing the outcome, in this case counselling practices. These factors are then used to determine the program objectives, to develop and tailor program activities and to design the evaluation. Program activities during the first 3 years included cessation counselling workshops and conferences for GPs, publication of articles in professional interest journals, publication of clinical guidelines for smoking cessation counselling and dissemination of educational material for both GPs and smokers. The program also supported activities encouraging smokers to ask their GPs to help them stop smoking. Results from 2 cross-sectional surveys, conducted in 1998 and 2000, of random samples of approximately 300 GPs suggest some improvements over time in several counselling practices, including offering counselling to more patients and discussing setting a quit date. More improvements were observed among female than male GPs in both psychosocial factors related to counselling and specific counselling practices. For example, improvements were noted among female GPs in self-perceived ability to provide effective counselling and in the belief that it is important to schedule specific appointments to help patients quit; in addition, the perceived importance of several barriers to counselling decreased among female GPs. A greater proportion of the female respondents to the 2000 survey offered written educational material than was the case in 1998, and a greater proportion of the male GPs devoted more time to counselling in 2000 than in 1998; however, among male GPs the proportion who discussed the pros and cons of smoking with patients in the pre-contemplation stage declined between 1998 and 2000, as did the proportion who referred patients in the preparation stage to community resources. Our experience suggests that an integrated, theory-based program to improve physicians' counselling practices could be a key component of a comprehensive strategy to reduce tobacco use.

Counseling↗
PubMed2001

Role of CD23 in astrocytes inflammatory reaction during HIV-1 related encephalitis.

Soluble factors released by intra-cerebral activated cells are implicated in neuronal alterations during central nervous system inflammatory diseases. In this study, the role of the CD23 pathway in astrocyte activation and its participation in human immunodeficiency virus-1 (HIV-1)-induced neuropathology were evaluated. In human primary astrocytes, CD23 protein membrane expression was dose-dependently upregulated by gp120. It was also upregulated by gamma-interferon (gamma-IFN) and modulated by interleukin-1-beta (IL-1beta) whereas microglial cells in these stimulation conditions did not express CD23. Cell surface stimulation of CD23 expressed by astrocytes induced production of nitric oxide (NO) and IL-1beta which was inhibited by a specific inducible NO-synthase (iNOS) inhibitor (aminoguanidine), indicating the implication of this receptor in the astrocyte inflammatory reaction. On brain tissues from five out of five patients with HIV-1-related encephalitis, CD23 was expressed by astrocytes and by some microglial cells, whereas it was not detectable on brain tissue from five of five HIV-1-infected patients without central nervous system (CNS) disease or from two of two control subjects. In addition, CD23 antigen was co-localized with iNOS and nitrotyrosine on brain tissue from patients with HIV1-related encephalitis, suggesting that CD23 participates in iNOS activation of astrocytes in vivo. In conclusion, CD23 ligation is an alternative pathway in the induction of inflammatory product synthesis by astrocytes and participates in CNS inflammation.

AIDS Dementia Complex↗
PubMed2001

[Epidemiology of tinea capitis].

PREDOMINANT IN CHILDREN: Tinea capitis is the most frequent fungal infection in children under the age of puberty. It occurs only rarely in men but is observed in adult women. Human-to-human, animal-to-human and soil-to-human transmission can be involved. HISTORICAL BACKGROUND: The spectrum of fungal species known to cause tinea capitis has steadily grown for more than a century, varying with the local urban or rural environment. Since the beginning of the 20th century and up to the advent of griseofulvin in the sixties, M. audouinii, an anthropophilic species, caused major epidemics in France, England and the USA. In the sixties to eighties, M. canis was the cause of most cases observed throughout the world. Over the last 20 years, anthropophilic species have again become the leading cause of tinea capitis epidemics, particularly in large cities, in relationship with immigration: T. tonsuransi in the USA and England and T. soudanense and M. langeronii in France. HYGIENE AND EDUCATION: Despite the benign curable nature of the disease, interhuman transmission of tinea capitis is nevertheless a considerable public health problem due to the increasing number of children affected and the risk of contagion in schools. The considerations resulting from recent studies point out the fact that transmission occurs more often in the family than the school setting, particularly indirectly by common use of grooming instruments. This would explain the high percentage of tinea capitis in large immigrant families where hair combing habits favor transmission. In France, these observations should lead to a revision of the current regulations concerning expulsion from school of children affected by tinea capitis. Better education would be a more appropriate response to the problem.

Adolescent↗
PubMed2001

Massive gene decay in the leprosy bacillus.

Leprosy, a chronic human neurological disease, results from infection with the obligate intracellular pathogen Mycobacterium leprae, a close relative of the tubercle bacillus. Mycobacterium leprae has the longest doubling time of all known bacteria and has thwarted every effort at culture in the laboratory. Comparing the 3.27-megabase (Mb) genome sequence of an armadillo-derived Indian isolate of the leprosy bacillus with that of Mycobacterium tuberculosis (4.41 Mb) provides clear explanations for these properties and reveals an extreme case of reductive evolution. Less than half of the genome contains functional genes but pseudogenes, with intact counterparts in M. tuberculosis, abound. Genome downsizing and the current mosaic arrangement appear to have resulted from extensive recombination events between dispersed repetitive sequences. Gene deletion and decay have eliminated many important metabolic activities including siderophore production, part of the oxidative and most of the microaerophilic and anaerobic respiratory chains, and numerous catabolic systems and their regulatory circuits.

Animals↗
PubMed2001

Value of antigen detection using an enzyme immunoassay in the diagnosis and prediction of invasive aspergillosis in two adult and pediatric hematology units during a 4-year prospective study.

BACKGROUND: Invasive aspergillosis (IA) is a well recognized, life-threatening infection in neutropenic patients and stem cell transplantation recipients. Early diagnosis is important to achieve the best outcome for these patients; however, definite proof often is difficult to obtain due to counterindicated invasive procedures. METHODS: This study evaluated the specificity and sensitivity of the detection of galactomannan (GM) for the diagnostic and prediction of IA in 347 children from the Pediatric Hematology Service and 450 patients from the Bone Marrow Transplantation Unit at the Hôpital Saint-Louis in Paris. Serial screening of Aspergillus GM circulating antigen was evaluated using a double sandwich ELISA assay (Platelia Aspergillus) on 6209 sera. Among the patients studied, 53 presented with confirmed IA (n = 27 patients) or probable IA (n = 26 patients). RESULTS: Antigen was detected on at least two sequential sera in 48 of 53 patients, with a sensitivity of 90.6%. GM antigenemia was detected before the onset of radiologic signs in 31 of 48 patients (64.6%), with a mean of -8.4 days, and before clinical symptoms in 18 of 48 patients (39.6%), with a mean of -6.9 days. In patients without IA, 44 of 744 had positive antigenemia, resulting in a specificity of 94%. False positive results could not be related to the presence of a concurrent mucositis. CONCLUSIONS: This large, prospective study allowed the authors to define better the conditions for the use of GM immunocapture ELISA in surveying patients who are at high risk for IA. The presence of antigen has a good diagnostic value mainly when there is an increase in the titer on two consecutive sera samples. A repeated negative result is a strong argument against the diagnosis of IA; however, an awareness of the possibility of unexplained false negative results is important.

Adolescent↗
PubMed2001

Smoking cessation counseling practices of general practitioners in Montreal.

BACKGROUND: Despite the cost-effectiveness of physician smoking cessation counseling, many physicians do not adhere to current clinical practice guidelines. METHODS: A cross-sectional mail survey was conducted in a random sample of general practitioners in Montreal to document cessation-counseling practices and identify correlates of these activities. RESULTS: Of 440 eligible general practitioners, 337 (77%) completed the questionnaire. Despite favorable beliefs/attitudes about cessation counseling, only 10.5% of general practitioners provided "thorough" counseling. While high proportions of general practitioners ascertained smoking status and encouraged patients to quit, relatively few offered adjunct support (i.e., for patients preparing to quit, 49.8% offered follow-up visits; 42.5% offered educational material; 20% referred patients to community resources). Correlates of counseling completeness included high self-efficacy to provide counseling (odds ratio (OR) = 2.0, 95% confidence interval (1.1-3.6)) and favorable beliefs/attitudes about counseling (OR = 3.6 (2.0-6.4)). Correlates of ascertaining smoking status included female gender (OR = 2.3 (1.5-3.5)), high self-efficacy (OR = 3.5 (2.0-5.9)), and favorable beliefs/attitudes (OR = 2.7 (1.6-4.5)). Correlates of offering adjunct support included female gender (OR = 1.9 (1.1-3.2)), awareness of stages of change (OR = 2.4 (1.3-4.4)), and knowledge of community resources to help patients quit (OR = 2.3 (1.3-3.9)). CONCLUSION: Support, training, and intervention programs to overcome lack of awareness and knowledge, unfavorable beliefs/attitudes, and low self-efficacy could increase and enhance cessation counseling practices among general practitioners.

Adult↗
PubMed2001

Production and characterization of anti-nisin Z monoclonal antibodies: suitability for distinguishing active from inactive forms through a competitive enzyme immunoassay.

As a pre-requisite to monoclonal antibody development, an efficient purification strategy was devised that yielded 72 mg of nisin Z from 14.5 1 of Lactococcus lactis subsp. lactis biovar. diacetylactis UL 719 (L. diacetylactis UL719) culture in supplemented whey permeate. Specific monoclonal antibodies (mAbs) were produced in mice against the purified nisin Z using keyhole limpet hemocyanin as a carrier protein. These antibodies did not recognize nisin A, suggesting that the asparagine residue at position 27 is involved in antibody recognition to nisin Z. However, the high reactivity of mAbs against biologically inactive nisin Z degradation products, produced during storage of freeze-dried pure nisin Z at -70 degrees C, indicated that the dehydroalanine residue at position 5 (Dha5), required for biological activity, is not necessary in nisin Z recognition by the mAb. A competitive enzyme immunoassay (cEIA) using the specific anti-nisin Z mAb was developed and used for rapid and sensitive detection and quantification of nisin Z in fresh culture supernatant, milk and whey. Detection limits of 78 ng/ml in phosphate-buffered saline, 87 ng/ml in culture supernatant, 106 ng/ml in milk and 90.5 ng/ml in whey were obtained for this assay. The cEIA using specific mAbs can be used to quantify nisin Z in food products.

Antibodies, Monoclonal↗
PubMed2001

New method for exopolysaccharide determination in culture broth using stirred ultrafiltration cells.

A new method to remove simple carbohydrates from culture broth prior to the quantification of exopolysaccharides (EPS) was developed and validated for the EPS-producing strain, Lactobacillus rhamnosus RW-9595M. This method uses ultrafiltration (UF) in stirred cells followed by polysaccharide detection in the retentate by the phenol-sulfuric acid method. The UF method was compared with a conventional method based on ethanol extraction, dialysis, protein removal by trichloroacetic acid (TCA) and freeze-drying. EPS production during pH-controlled batch fermentations in basal minimum medium, whey permeate (WP). and whey permeate supplemented with yeast extract, minerals and Tween-80 (SWP) was determined by the new UF and conventional methods. EPS recovery by the new method ranged from 83% to 104% for EPS added in the concentration range 40-1,500 mg/l in 0.1 M NaCl solution or culture medium. The UF method was rapid (8 h), accurate and simple, and required only a small sample volume (1-5 ml). A very high maximum EPS production was measured in SWP by both the UF and conventional methods (1,718 and 1,755 mg/l).

Lactic Acid↗
PubMed2001

Relationship between environmental fungal contamination and the incidence of invasive aspergillosis in haematology patients.

Invasive aspergillosis (IA) is a major opportunistic infection in haematology patients. Spore inhalation is the usual route of Aspergillus infection, suggesting a determining role of environmental contamination by spores in the epidemiology of IA. We prospectively examined the relationship between environmental contamination by Aspergillus and other fungal species and the incidence of invasive nosocomial aspergillosis (INA) in a bone marrow transplantation unit and two haematology wards. During a four-year period, levels of air and surface fungal contamination were determined bi-monthly in patients' rooms (some equipped with HEPA filters and LAF systems), and various common sites in each ward (corridors, nursing stations, etc.). Results were compared to the incidence of INA. A total of 3100 air and 9800 surface samples were collected, and 79 cases of IA were diagnosed, of which 64 were probably or possibly INA. Patterns of fungal contamination were comparable in the three wards, with a gradient ranging from high levels in common sites to a virtual absence in rooms equipped with HEPA filters and LAF systems. Using a regression model, a significant relationship was found between the incidence of INA and the degree of fungal contamination of air and surfaces in conventional patient rooms (not equipped with HEPA) and common sites. This study shows that in a non-epidemic setting, there is a significant relationship between environmental fungal contamination in haematology wards and the incidence of INA. Our findings underline the importance of environmental surveillance and strict application of preventive measures.

Aspergillosis↗
PubMed2001

Arthrogryposis and multicystic encephalopathy after acute fetal distress in the end stage of gestation.

The natural history of the rare association "multicystic encephalopathy-arthrogryposis" was traced in a fetus carefully followed after artificial insemination. The fetus exhibited normal viability and brain morphology up to the 32nd week. At 36 weeks, active movements diminished and at 37 weeks, hydramnios and signs of fetal distress led to cesarean section. The infant presented with severe arthrogryposis of the limbs and spine, but not with the other elements of a long-lasting akinesia. US showed multicystic encephalopathy. Both the clinical and the neuropathological findings established that multicystic encephalopathy was neither the cause nor the sequential consequence of the fetal akinesia, but the result of a recent diffuse, acute malacic process that also involved the anterior horn cells. Acute fetal distress, responsible for major ischemic damage to CNS but compatible with fetal survival, remains an obscure condition which allows for the development of severe arthrogryposis in a few weeks.

Anterior Horn Cells↗
PubMed2001

Direct muscle neurotization after end-to-side neurorrhaphy.

Over the recent years, end-to-side neurorrhaphy has reemerged in the literature for reconstructive nerve surgery. Another technique, in which interest has remained continuous during the last century, is direct nerve implantation into muscle belly, so-called direct muscle neurotization (DMN). In this work, the authors present a new technique to recover muscle innervation through direct nerve implantation into muscle belly, by means of a nerve graft, and sutured with end-to-side neurorrhaphy. They carried out experiments on 20 Wistar rats divided into two groups. In Group 1 (10 rats), on the right side, the peroneal nerve was sutured to the tibial nerve with end-to-side neurorrhaphy. Subsequently, the terminal branches of the same nerve were implanted in the anterior tibial muscle (ATM). On the left side, the peroneal nerve was severed, and the ATM completely denervated. In Group 2 (10 rats), on the right side, the same technique was used as in first group. On the left side, the normal innervation of the ATM was maintained. After 4 months, all muscles and nerves were harvested and evaluations carried out on the morphologic aspect, weight, and histology of the ATM, as well as the histology of the nerves. The authors analyzed the results, which demonstrated good reinnervation of the muscles deprived of any nerve connection.

Anastomosis, Surgical↗
PubMed2001

Rapid discrimination among dermatophytes, Scytalidium spp., and other fungi with a PCR-restriction fragment length polymorphism ribotyping method.

Dermatomycoses are very common infections caused mainly by dermatophytes. Scytalidiosis is a differential mycological diagnosis, especially in tropical and subtropical areas. Since a culture-based diagnosis takes 2 to 3 weeks, we set up a PCR-restriction fragment length polymorphism (RFLP) method for rapid discrimination of these fungi in clinical samples. The hypervariable V4 domain of the small ribosomal subunit 18S gene was chosen as the target for PCR. The corresponding sequences from 19 fungal species (9 dermatophytes, 2 Scytalidium species, 6 other filamentous fungi, and 2 yeasts) were obtained from databases or were determined in the laboratory. Sequences were aligned to design primers for dermatophyte-specific PCR and to identify digestion sites for RFLP analysis. The reliability of PCR-RFLP for the diagnosis of dermatomycosis was assessed on fungal cultures and on specimens from patients with suspected dermatomycosis. Two sets of primers preferentially amplified fungal DNA from dermatophytes (DH1L and DH1R) or from Scytalidium spp. (DH2L and DH1R) relative to DNA from bacteria, yeasts, some other filamentous fungi, and humans. Digestion of PCR products with EaeI or BamHI discriminated between dermatophytes and Scytalidium species, as shown with cultures of 31 different fungal species. When clinical samples were tested by PCR-RFLP, blindly to mycological findings, the results of the two methods agreed for 74 of 75 samples. Dermatophytes and Scytalidium spp. can thus be readily discriminated by PCR-RFLP within 24 h. This method can be applied to clinical samples and is suited to rapid etiologic diagnosis and treatment selection for patients with dermatomycosis.

Ascomycota↗
PubMed2001

Metformin retention independent of renal failure in intestinal occlusion.

Metformin is eliminated by the kidneys, and metformin accumulation has always been noticed in oligo-anuric patients. We have reported an exception to the rule with the case of a metformin-treated patient having metformin accumulation contrasting with a mild increase in serum creatinine in the context of a volvulus of the sigmoid colon. This case prompted us to examine the association between intestinal occlusion and plasma metformin concentrations. For this purpose, we developed an experimental animal model of mechanical obstruction of the intestine. Rats were pre-treated during 3 weeks via drinking solution at a dose of approximately 100 mg/kg/day of metformin. They underwent at day 0 either sham-operation (n=7) or operation (n=8) to place a plastic tube around the ileum near the ileocaecal valve. Metformin administration was pursued on days 1, 2, and 3 giving a single dose of 100 mg/kg by intragastric gavage. Four days after the surgery, i.e. 24 h after the last metformin administration, the surviving intestinal obstructed rats (n=8) developed overt intestinal dilation but no biochemical abnormality compared to sham-operated animals (n=7; arterial lactate concentrations respectively 4.87 +/- 0.63 mmol/l and 3.97 +/- 0.30 mmol/l, NS, and serum creatinine concentrations 69.0 +/- 1.7 micromol/l and 68.7 +/- 1.9 micromol/l, NS). By contrast, there was a striking difference with regard to metformin concentrations, decreasing from 2.95 +/- 0.94 mg/l at day 0 to 0.12 +/- 0.03 mg/l at day 4 (p<0.001) in the sham-operated group but remaining unchanged (1.65 +/- 0.76 mg/l and 1.61 +/- 0.51 mg/l) in the operation group. In conclusion, this is the first experiment showing that intestinal occlusion may be responsible for metformin retention in the absence of renal failure. Whether this observation may be relevant to other drugs remains to be established.

Acute Kidney Injury↗
PubMed2001

Comparison of the activity spectra against pathogens of bacterial strains producing a mutacin or a lantibiotic.

The increase of drug resistance among bacterial pathogens is currently a major threat in hospital settings. New and more efficient antibiotic compounds have to be developed to fight infectious diseases. In the present work, a deferred antagonism test was used to determine the activity of different bacterial strains producing either a mutacin or a lantibiotic against bacterial pathogens. The mutacins A, B, C, D, I, K, L, M, and nisins A and Z were active against all enterococci tested. Mutacins A and B, and nisins A and Z inhibited all the staphylococci tested. Except for the strains producing mutacins P, Q, and X, all the other producing strains inhibited the streptococci tested. Mutacins A, B, I, J, T, nisins A and Z, and epidermin inhibited the two antibiotic-resistant strains of Neisseria gonorrhoeae tested. Mutacins A, B, C, D, and nisins A and Z inhibited Campylobacter jejuni and Helicobacter pylori. Thus, the wide activity spectra of nisin A and Z are confirmed. These results also indicate that many of the mutacins, especially those of groups A, B, C, D, I, J, K, L, M, and T, could be candidates for further development as useful antibiotics.

Anti-Bacterial Agents↗
PubMed2000

Effects of mixed starter composition on nisin Z production by lactococcus lactis subsp. lactis biovar. diacetylactis UL 719 during production and ripening of Gouda cheese.

A starter culture system that produced both acid and nisin at acceptable rates in milk for manufacture of Gouda cheese was developed using nisin Z-producing L. lactis subsp. lactis biovar. diacetylactis UL 719 (UL 719) and a commercial Flora Danica (FD) starter culture. Different compositions of mixed cultures (0, 0.2, 0.4, 0.6 or 0.8% UL 719 with 1.4% FD) were tested for acidification and nisin Z production in milk after 12 h incubation at 30 degrees C. The 0.6/1.4% combination, selected as the optimal mixture of starter cultures, acidified milk to a suitable pH and produced nisin Z at a high concentration of 512 IU/ml. With this optimal combination, FD numbers of citrate-fermenting and non-fermenting bacteria did not change compared with the control (1.4% FD). However, with 0.8% of L. lactis strain UL 719 and 1.4% of the FD starter culture, the numbers of citrate-fermenting and non-fermenting bacteria in fermented milk decreased compared with those obtained when milk was inoculated with 0.2, 0.4 or 0.6% of UL 719 added to 1.4% FD or control cultures (1.4% FD). Mixed starter culture ratios 0.6/1.4%, 0.4/1.4% and 0.5/1.4% (UL 719/FD) were used to manufacture nisin Z containing Gouda cheese which was ripened up to 45 weeks. The composition of control cheeses made with 1.4% FD, and nisin Z-containing Gouda cheeses were similar with respect to percent moisture, fat, salt and protein. During the ripening period, the cell counts observed were approximately two logs higher in cheese made with the 0.6/1.4% mixed starter culture than in control cheese. In experimental cheese produced with 0.6/1.4% (UL 719/FD) mixed starter culture, nisin activity increased from 256 IU/g at the end of manufacture to a maximum of 512 IU/g after 6 weeks of ripening; the levels then decreased to 128 and 32 IU/g after 27 and 45 weeks of ripening, respectively. In contrast, nisin Z was not detected in experimental cheeses made with 0.4/1.4% or 0.5/1.4% (UL 719/FD) mixed starters. Using an affinity purified anti-nisin polyclonal antibody, anti-rabbit gold-conjugate and transmission electron microscopy, nisin Z was found to be localized in the cheese matrix, in fat globules, in the casein phase and concentrated at the fat-casein interface. After 27 weeks of ripening, nisin Z was detected preferentially in the fat globules of the experimental cheese.

Cheese↗