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Biomedical subjects

R Verdon

Publications and source records attributed to R Verdon.

At least 19 recordsLinked to original sources

[Restropective investigation about the treatment of candidaemia in a French university hospital in 2004].

This study aimed to retrospectively evaluate the adequate use of antifungal drugs in the treatment of the candidaemia. A collection of clinical, biological and therapeutic data was carried out for the patients who had a positive blood culture for Candida species during the year 2004. The antifungal therapy was compared to the guidelines of the French Conference of consensus named "Prise en charge des candidoses et aspergilloses invasives de l'adulte". The degree of conformity was classified as follows: complying, partly complying (molecule in conformity but delay of treatment or unsuited dosing) and not complying with the guidelines. The analysis was performed, according to the guidelines, before and after knowledge of Candida species growing from the blood culture. On 29 candidaemia, the found species were: Candida albicans 55%, Candida glabrata 14%, Candida krusei 10%, Candida parapsilosis and Candida lusitaniae 7%, Candida pelliculosa and Candida tropicalis 3.5%. Only 19 candidaemia were included in this study because blood cultures were known positive for Candida on the day of death (N=7) or medical charts were not available (N=3). For treatment before identification of Candida species, 37% were complying, 37% in partly complying and 26% not complying with the guidelines. For the treatment after identification of the species, 26% were complying, 63% partly complying and 11% not complying with the guidelines. As a whole, antifungal therapy was totally or partly complying in 74 to 89% of candidaemia in adult patients. Lower dosages of fluconazole explained most of the treatments that partly complied with guidelines.

Candida glabrata↗

[Acute renal failure with acyclovir in a 42-year-old patient without previous renal dysfunction].

INTRODUCTION: Herpetic meningoencephalitis is treated with acyclovir (15 mg/kg/8 h). This higher dosage enhance the risk of acute renal failure. CASE REPORT: We report the case of a previously healthy 42 years old man treated by intravenous aciclovir 1g/8 h for a herpetic meningoencephalitis. He presented an acute renal failure and an acute confusional state at the end of the treatment. Renal function and neurologic status improved rapidly with increased hydration and stop of the antiviral therapy. CONCLUSION: If acyclovir is usually well tolerated, there is also a risk of acute nephropathy, especially dose-dependent. We point out the need to monitor renal function when high dosage of acyclovir is indicated.

Acute Kidney Injury↗

Mediation of Cryptosporidium parvum infection in vitro by mucin-like glycoproteins defined by a neutralizing monoclonal antibody.

The protozoan parasite Cryptosporidium parvum is a significant cause of diarrheal disease worldwide. Attachment to and invasion of host intestinal epithelial cells by C. parvum sporozoites are crucial steps in the pathogenesis of cryptosporidiosis. The molecular basis of these initial interactions is unknown. In order to identify putative C. parvum adhesion- and invasion-specific proteins, we raised monoclonal antibodies (MAbs) to sporozoites and evaluated them for inhibition of attachment and invasion in vitro. Using this approach, we identified two glycoproteins recognized by 4E9, a MAb which neutralized C. parvum infection and inhibited sporozoite attachment to intestinal epithelial cells in vitro. 4E9 recognized a 40-kDa glycoprotein named gp40 and a second, >220-kDa protein which was identified as GP900, a previously described mucin-like glycoprotein. Glycoproteins recognized by 4E9 are localized to the surface and apical region of invasive stages and are shed in trails from the parasite during gliding motility. The epitope recognized by 4E9 contains alpha-N-acetylgalactosamine residues, which are present in a mucin-type O-glycosidic linkage. Lectins specific for these glycans bind to the surface and apical region of sporozoites and block attachment to host cells. The surface and apical localization of these glycoproteins and the neutralizing effect of the MAb and alpha-N-acetylgalactosamine-specific lectins strongly implicate these proteins and their glycotopes as playing a role in C. parvum-host cell interactions.

Animals↗

Detection of viral, Chlamydia pneumoniae and Mycoplasma pneumoniae infections in exacerbations of asthma in children.

BACKGROUND: A high frequency of virus infections has been recently pointed out in the exacerbations of asthma in children. OBJECTIVES: To confirm this, using conventional and molecular detection methods, and expanding the study to younger children. STUDY DESIGN: One hundred and thirty-two nasal aspirates from 75 children hospitalized for a severe attack of asthma were studied (32 infants, mean age 9.1 months; and 43 children, mean age 5.6 years). According to the virus, a viral isolation technique, immunofluorescence assays (IFA) or both were used for the detection of rhinovirus, enterovirus, respiratory syncytial (RS) virus, adenovirus, coronavirus 229E, influenza and parainfluenza virus. Polymerase chain reaction (PCR) assays were used for the detection of rhinovirus, enterovirus, RS virus, adenovirus, coronavirus 229E and OC43, Chlamydia pneumoniae and Mycoplasma pneumoniae. RESULTS: Using IFA and viral isolation techniques, viruses were detected in 33.3% of cases, and by PCR techniques, nucleic acid sequences of virus, Chlamydia pneumoniae and Mycoplasma pneumoniae were obtained in 71.9% of cases. The combination of conventional and molecular techniques detects 81.8% of positive samples. Two organisms were identified in the same nasal sample in 20.4% of the cases. The percentage of detections was higher (85.9%) in the younger group than in the other (77%). The most frequently detected agents were rhinovirus (46.9%) and RS virus (21.2%). Using PCR rather than conventional techniques, the detection rates were increased 5.8- and 1.6-fold in rhinovirus and RS virus infections, respectively. The detection levels of the other organisms are as follows: 9.8, 5.1, 4.5, 4.5, 4.5, 3.7, and 2.2% for enterovirus, influenza virus, Chlamydia pneumoniae, adenovirus, coronavirus, parainfluenza virus, and Mycoplasma pneumoniae, respectively. CONCLUSION: These results confirm the previously reported high frequency of rhinovirus detection in asthmatic exacerbations in children. They also point out the frequency of RS virus detection, and emphasize the fact that PCR assays may be necessary to diagnose respiratory infections in asthma.

Adolescent↗

Cryptosporidium parvum biliary tract infection in adult immunocompetent and immunosuppressed mice.

Biliary tract infection by Cryptosporidium parvum is a frequent complication of intestinal cryptosporidiosis in immunosuppressed patients. Although biliary tract infection can be produced in immunosuppressed models as a late complication of intestinal infection, there is no infection model in immunocompetent animals. A murine model of biliary tract cryptosporidiosis was developed by direct intra-gall bladder injection of C. parvum oocysts. In adult immunocompetent mice, intracellular parasitic stages were detected in the epithelium of the common bile duct in all animals on day 7 post-inoculation (p.i.). These findings were associated with a strong inflammatory reaction. Infection was cleared between days 14 and 21 p.i. All animals developed significant levels of specific serum and bile IgG, IgA and IgM. Dexamethasone treatment resulted in the inability of animals to eradicate the parasite and the establishment of ileal parasitism. This model can be used to study the immunological mechanisms involved in the control of biliary cryptosporidiosis.

Animals↗

Attachment of Cryptosporidium parvum sporozoites to human intestinal epithelial cells.

An enzyme-linked immunosorbent assay-based attachment model using the human intestinal cell line Caco-2A was developed to study attachment of Cryptosporidium parvum sporozoites in vitro and to assess potential inhibitors of sporozoite binding. In this system, attachment was related to sporozoite dose, incubation time, and host cell differentiation status. Polyclonal antibodies to C. parvum as well as glycoprotein inhibitors of a sporozoite lectin reduced attachment. This model will be a valuable tool in elucidating specific molecules and mechanisms involved in sporozoite-host cell attachment.

Adhesiveness↗

An in vitro model of infection of human biliary epithelial cells by Cryptosporidium parvum.

Cryptosporidium parvum infection in the immunosuppressed host is frequently complicated by biliary tract involvement. The recent production of human biliary epithelial cell lines was exploited to develop an in vitro model of biliary cryptosporidiosis. Infection with C. parvum oocysts was detected by IFA and ELISA and confirmed by transmission electron microscopy. Inoculation of monolayers with 10(4) to 5 X 10(5) oocysts/well resulted in a dose-dependent increase in infection. Time-course experiments showed that the number of parasitic stages was maximal at 18-24 h after inoculation. Infection was significantly enhanced by bile at concentrations of 50 and 100 microg/mL and inhibited by 400 microg/mL paromomycin. Infection of human biliary cells with C. parvum can be consistently achieved and monitored by use of IFA or ELISA. This system will be of use in evaluating mechanisms of C. parvum infection and response to therapeutic agents in biliary cryptosporidiosis.

Amebicides↗

Herpes simplex esophagitis in patients with AIDS: report of 34 cases. The Cooperative Study Group on Herpetic Esophagitis in HIV Infection.

Herpetic esophagitis (HE) associated with human immunodeficiency virus (HIV) is a rare condition mainly reported as isolated cases. We thus decided to study this association and analyze the possible predisposing factors, clinical and endoscopic presentations, and clinical response to treatment. Thirty-four HIV-1-infected patients were identified: 27 had histologically or virologically confirmed HE and seven had probable HE, a retrospective diagnosis based on the efficacy of acyclovir given alone. The median CD4 cell count was 15/mm3. Recent predisposing factors (such as nasogastric procedures, steroid therapy, and anticancer therapy) were noted with regard to 16 of the 34 patients (47%). Odynophagia and/or chest pain occurred in 30 patients (88%). At the time of diagnosis of HE, extraesophageal herpes was found in only 13 patients (38%). Superficial ulcers of the distal third of the esophagus were present in 17 (50%). Among 20 of the 27 patients with confirmed HE that could be evaluated, therapy with acyclovir led to complete resolution in 16 and partial response in 3; 1 patient died of HE. Five patients (15%) suffered confirmed or possible relapses. The mean interval between the diagnosis of HE and death was 8.8 months. Herpes simplex virus may be responsible for ulcerated esophagitis that occurs in the advanced stages of AIDS and that can be safely treated with acyclovir before a definitive diagnosis is made.

AIDS-Related Opportunistic Infections↗

Tuberculous meningitis in adults: review of 48 cases.

The cases of 48 adult patients with tuberculous meningitis who were admitted to intensive care unit (ICU) between 1982 and 1993 were reviewed. An underlying disease was present in 24 patients (50%), including 10 with human immunodeficiency virus infection. Forty-seven patients were referred to the ICU because of neurological deterioration; 22 were comatose at admission. Forty-six patients received antituberculous treatment; 36 required mechanical ventilatory support, and 16 underwent neurosurgery. Thirty-one patients died within 4 months after admission, and the remaining 17 were alive at a 1-year follow-up. Univariate prognostic analysis selected three variables, all assessed at admission, associated with outcome: time to onset of treatment of > or = 3 days (P = .003), coma (P = .006), and simplified acute physiology score of > 11 (P = .03). Thus, the outcome of tuberculous meningitis is mainly determined by the clinical stage at admission and the delay in starting treatment. These findings underscore the need to initiate early therapy as soon as the diagnosis of tuberculous meningitis is suspected.

Adolescent↗

[Diagnosis of colitis caused by cytomegalovirus infection in AIDS. Comparative value of total colonoscopy and rectosigmoidoscopy (apropos of 24 cases). AIDS GIT].

OBJECTIVES: To evaluate the respective diagnostic value of flexible rectosigmoidoscopy and colonoscopy in the cytomegalovirus colitis. METHODS: Twenty-four patients with AIDS were studied retrospectively. The entry criteria were: flexible rectosigmoidoscopy or colonoscopy, with 2 rectal and 2 caecal biopsies, presenting cytomegalovirus inclusions bodies linked to an inflammation at least on one colonic biopsy. RESULTS: Twenty-four patients had 29 colonoscopies. In 16 cases colonoscopy was performed to the caecum. The endoscopic findings of the 16 full colonoscopies were: 7 right colitis, 5 diffuse colitis, 2 bisegmentary colitis, 1 proctitis and 1 non endoscopic lesion. The histologic findings of the 16 full colonoscopies were: 5 cytomegalovirus inclusions on rectal biopsies and 16 on caecal biopsies. For the 13 incomplete colonoscopies, 11 had inclusions on rectal biopsies. So the flexible rectosigmoidoscopy was not sufficient to find inclusions 13 times out of 29. CONCLUSION: Our study indicates that in the cytomegalovirus colitis, inclusions predominate in the caecum, isolated right colitis exists and extra-colonic cytomegalovirus disease is not always found. For these reasons full colonoscopy is necessary for diagnosis in patients with normal flexible rectosigmoidoscopy.

AIDS-Related Opportunistic Infections↗

[Digestive involvements in human immunodeficiency virus infection].

Dysphagia or odynophagia occurs in an estimated 21% of patients with human immunodeficiency virus infection. A causal agent can be identified in 60-90% of the cases and generally can be successfully eradicated. Oesophageal candidosis, the predominant disorder, usually responds to nitrate derivatives and amphotericine B after a 10 to 15 day cure. Ulcerations of the oesophagus is the second major cause of dysphagia in these patients and result from cytomegalovirus and herpes simplex infections or unknown causes. Epstein-Barr virus infection has been suggested but is rarely demonstrated in clinical situations. Similar to other localizations in HIV-infected patients, Kaposi sarcoma and non-Hodgkin malignant lymphomas are the predominant tumours in the bowel. Infections are essentially revealed by sometimes very severe diarrhoea. Infective agents include Cryptosporidium parvum, microsporidiosae, cytomegalovirus, adenovirus, Isospora belli, Clostridium difficile, Salmonellae and non-tuberculous mycobacteria among others. When the search for an infective agent is negative, the diarrhoea is usually considered to be the expression of HIV infection itself. The clinical approach to HIV-related diarrhoea can be based on decision making management scheme according to the results of stool cultures or on complete exploration protocols. Whatever the diagnostic procedure, symptomatic treatment is of major importance because of the severe nutritional impact of HIV-related diarrhoea.

Digestive System Diseases↗

Evaluation of high-dose regimen of paromomycin against cryptosporidiosis in the dexamethasone-treated rat model.

In the dexamethasone-treated rat model of cryptosporidiosis, paromomycin was effective at a dosage of 50 mg/kg/day or more for ileal infection and 200 mg/kg/day or more for cecal infection. At 1 and 3 weeks after treatment, a persistent infection was demonstrated in all rats. These results confirm the anticryptosporidial activity of paromomycin and underscore the limitations of this compound because of its potential toxicity at such high dosages and its inability to eradicate the infection.

Animals↗

Absence of association between HLA antigens and chronicity of viral hepatitis in haemodialyzed patients.

The role of HLA antigens in the chronicity of viral hepatitis is still being debated. We analyzed the relation between HLA status and viral hepatitis in 558 consecutive haemodialyzed patients who underwent kidney transplantation. HLA A, B, DR status, ABO-Rh blood group, duration of haemodialysis, and number of blood units transfused during the dialysis period were known for all patients. Serological status for hepatitis B virus and hepatitis C virus and results of liver biopsies were available in 495, 300 and 316 patients, respectively. After correction for the number of tests performed, frequencies of HLA antigens did not differ significantly for: 1. hepatitis B virus infection (compared to HBsAg-positive and anti-HBc and/or anti-HBs-positive nonvaccinated patients); 2. hepatitis C virus infection (compared to anti-HCV-negative and -positive patients); 3. histopathological status (compared to patients who had chronic viral hepatitis and those who did not). These results suggest that there is no evidence for a significant role of a particular HLA antigen in the development of chronic viral hepatitis in haemodialysis patients with similar underlying immunosuppression and exposure to infection by hepatotropic viruses.

Adult↗