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Biomedical subjects

Robert Cohen

Publications and source records attributed to Robert Cohen.

At least 37 records · Page 2Linked to original sources
PubMed2004

Activity of telithromycin and comparators against bacterial pathogens isolated from 1,336 patients with clinically diagnosed acute sinusitis.

BACKGROUND: Increasing antimicrobial resistance among the key pathogens responsible for community-acquired respiratory tract infections has the potential to limit the effectiveness of antibiotics available to treat these infections. Since there are regional differences in the susceptibility patterns observed and treatment is frequently empirical, the selection of antibiotic therapy may be challenging. PROTEKT, a global, longitudinal multicentre surveillance study, tracks the activity of telithromycin and comparator antibacterial agents against key respiratory tract pathogens. METHODS: In this analysis, we examine the prevalence of antibacterial resistance in 1,336 bacterial pathogens, isolated from adult and paediatric patients clinically diagnosed with acute bacterial sinusitis (ABS). RESULTS AND DISCUSSION: In total, 58.0%, 66.1%, and 55.8% of S. pneumoniae isolates were susceptible to penicillin, cefuroxime, and clarithromycin respectively. Combined macrolide resistance and reduced susceptibility to penicillin was present in 200/640 (31.3 %) of S. pneumoniae isolates (128 isolates were resistant to penicillin [MIC > or = 2 mg/L], 72 intermediate [MIC 0.12-1 mg/L]) while 99.5% and 95.5% of isolates were susceptible to telithromycin and amoxicillin-clavulanate, respectively. In total, 88.2%, 87.5%, 99.4%, 100%, and 100% of H. influenzae isolates were susceptible to ampicillin, clarithromycin, cefuroxime, telithromycin, and amoxicillin-clavulanate, respectively. In vitro, telithromycin demonstrated the highest activity against M. catarrhalis (MIC50 = 0.06 mg/L, MIC90 = 0.12 mg/L). CONCLUSION: The high in vitro activity of against pathogens commonly isolated in ABS, together with a once daily dosing regimen and clinical efficacy with 5-day course of therapy, suggest that telithromycin may play a role in the empiric treatment of ABS.

Journal Article↗
PubMed2004

Context-specific memory and apolipoprotein E (ApoE) epsilon 4: cognitive evidence from the NIMH prospective study of risk for Alzheimer's disease.

The aim of the study was to determine whether the epsilon 4 allele of the apolipoprotein E (ApoE) gene was associated primarily with context-specific memory among individuals at genetic risk for developing Alzheimer's disease. The effect of ApoE status on comprehensive neuropsychological results was examined in 176 healthy adults during baseline cognitive testing in the NIMH Prospective Study of Biomarkers for Older Controls at Risk for Alzheimer's Disease (NIMH Prospective BIOCARD Study). The presence of the epsilon 4 allele was associated with significantly lower total scores on the Logical Memory II subtest of the Wechsler Memory Scale-Revised and percent of information retained after delay. Further analysis indicated the prose recall and retention effect was partially explained by a small subgroup of epsilon 4 homozygotes, suggesting a gradually progressive process that may be presaged with specific cognitive measures. The current results may represent an epsilon 4-associated breakdown between gist-related information and context-bound veridical recall. This relative disconnection may be understood in light of putative epsilon 4-related preclinical accumulation of Alzheimer pathology (tangles and plaques) in the entorhinal cortex (EC) and among frontal networks, as well as the possibility of less-efficient compensatory strategies.

Adult↗
PubMed2004

Defining the optimum treatment regimen for azithromycin in acute tonsillopharyngitis.

Pharyngitis is one of the most common infectious diseases affecting children. Group A streptococci are the leading bacterial cause of pharyngitis in children and adults. Because inappropriate antibiotic treatment for pharyngitis is becoming a major issue, only true group A beta-hemolytic streptococcus (GABHS) infections, proven by rapid antigen test or culture, should be treated with antibiotics. GABHS pharyngitis is often a mild and self-limiting infection in the absence of antimicrobial therapy. However, antimicrobial treatment must be administered to eradicate the pathogen from the throat, limit the spread of the infection and prevent possible progression to rheumatic fever, suppurative disease or toxin-mediated complications. Penicillin V for 10 days is the standard therapy and is effective in the management of GABHS pharyngitis. However, there are drawbacks to penicillin V therapy, including the length of the dosing regimen, which are leading to decreasing penicillin prescription rates in many countries. In addition bacteriologic treatment failures have been documented in up to 35% of GABHS patients treated with penicillin V, particularly in children <6 years old. A number of mechanisms may be responsible for these failures, but poor compliance with the standard 10-day penicillin treatment is likely to be a major factor. There is growing evidence to suggest that children with GABHS pharyngitis can be effectively treated with non-penicillin V antibiotics, which have the advantage of simpler and shorter dosing regimens compared with penicillin V. Among the antibiotics that have been tested clinically, azithromycin is the most widely studied. A total dose of 60 mg/kg azithromycin, given either as 12 mg/kg once daily for 5 days or 20 mg/kg once daily for 3 days, provides the best rate of GABHS eradication. Thus a total dose of 60 mg/kg azithromycin given during 3 or 5 days constitutes an alternative treatment to standard penicillin therapy in cases of penicillin hypersensitivity, when patient nonadherence to a 10-day penicillin regimen is suspected or for patients who fail therapy with a beta-lactam.

Azithromycin↗
PubMed2004

Role of nitric oxide in skin flap delay.

Surgical delay of skin flaps before transfer is known to improve flap viability. This study attempts to elucidate the mechanism of vasodilation by exploring the effects of nitric oxide on the microcirculation of delayed skin flaps. Using a skin flap model in 22 CD-1 white mice, the diameter of two nonterminal choke arteries was measured using in vivo videomicroscopy. Vessel flow was also measured using an optical Doppler velocimeter. Similar measurements were recorded in several animals on the same vessels in which subcutaneous dissection without elevation was performed. Average vessel diameter ranged from 21.77 to 25.55 microm before skin flap delay. Average flow ranged from 1.72 to 2.44 nl/sec before delay. Next, each animal received an intraperitoneal dose of nitro-aminomethyl-1-arginine (L-NAME), a nitric oxide synthase inhibitor delivered by means of osmotic pump at a level of 0 (n = 13 arteries), 20 (n = 10), 50 (n = 8), or 100 mg/kg/day (n = 7). Flaps were re-elevated 72 hours later and the aforementioned measurements were repeated. Vessel diameter increased to 44.92 microm in the control (0 mg/kg L-NAME) animals. Flow increased to 7.66 nl/sec in the control animals. Vessel dilation and flow did not change significantly in the nonoperative vessels. As the dose of L-NAME increased in the treated animals, there was a significant decrease in vasodilation and flow (p = 0.015 and p = 0.03, respectively). The authors' results demonstrate that nitric oxide is an important element of vasodilation and contributor to the phenomenon of skin flap delay.

Animals↗
PubMed2004

Emergence of macrolide-resistant Streptococcus pyogenes strains in French children.

We studied the antimicrobial susceptibility of 322 Streptococcus pyogenes throat isolates from French children and their serotype and genomic diversity. A total of 22.4% were erythromycin resistant, and 69.4, 4.2, and 26.4% of these isolates harbored ermB, ermA, and mefA, respectively. Increasing resistance in France is mainly associated with a few emm type 28 clones.

Adolescent↗
PubMed2003

Halofantrine efficacy in non-immune children with imported acute Plasmodium falciparum malaria Infection.

UNLABELLED: A rising incidence of imported acute malaria has been observed in non-immune traveller children returning from the tropics to France. Halofantrine efficacy has been poorly assessed in non-immune children. In order to assess halofantrine efficacy in non-immune children with acute uncomplicated Plasmodium falciparum malaria, we collected data of children with positive blood smears in an open prospective study. Children with neurological manifestations, vomiting and congenital long QT were excluded. All children were hospitalised and received halofantrine (24 mg/kg divided into three doses per day) on an empty stomach. Persistent fever after day 3 defined failure. Relapse was defined by a positive blood smear with or without systemic symptoms within a 1 month follow-up period. In total, 52 children were enrolled. No failure was observed, but relapses occurred in 14/52. On univariate analysis, the mean age of children with relapse was significantly lower (P<0.05). Moreover, diarrhoea was more frequently associated with relapses (P<0.04). Age and diarrhoea were significant independent factors contributing to relapses. CONCLUSION: This study shows that with a relapse rate of 27%, this regimen with a 1-day course of halofantrine is not to be recommended.

Adolescent↗
PubMed2003

[How to prescribe fewer antibiotics in children?].

During the last years, there has been an alarming worldwide increase in antibiotic resistance among bacterial pathogens of the respiratory tract, and particularly pneumococcus. This is generally attributed to extensive use of antibiotics prescribed for respiratory tract infection and the selection pressure they exert on bacterial strains of nasopharyngeal flora. In our opinion, five actions have to be coordinated in order to control this phenomenon. To improve the continuing education of practitioners and the diagnosis between viral and bacterial respiratory infections, to restrict the use for the situations where antibiotics are really necessary, to prescribe in these situations at the right dosage and duration the more potent antibiotics, to plan straight-a-way an alternative treatment in case of failures, finally achieve a prompt implementation of the pneumococcal conjugate vaccine.

Anti-Bacterial Agents↗
PubMed2003

Child vaccination policies in Europe: a report from the Summits of Independent European Vaccination Experts.

Despite the proven safety and efficacy of vaccines, common vaccine-preventable diseases such as measles are not yet controlled in all European countries. This is largely due to three factors. First, vaccination systems differ widely throughout Europe and they vary between highly centralised and totally decentralised systems. Both have advantages and disadvantages, but without doubt they can all work locally. "Harmonisation" in this field is neither a prerequisite nor a guarantee for success. Second, perception of vaccination--and this includes education of the public--is most crucial. In this field the media play an important part, but their ability or will to communicate complicated scientific matters in an appropriate way to the public is often insufficient. Third, political will may be the single most important factor for success in vaccination. Only if the European Union comes up with and implements common vaccination goals with firm deadlines can the best health through vaccination of all Europeans be accomplished. The system as well as the schedule used would then be of minor importance.

Adolescent↗
PubMed2003

Diagnostic performance and retention of acquired skills after dermatology elective.

BACKGROUND: The dermatology elective often constitutes the future physician's only exposure to dermatologic practice. Cost-benefit considerations dictate that the elective enables the students to acquire useful diagnostic expertise in the short time period available, and that this expertise is not rapidly forgotten after completion of the elective. METHODS: In order to determine the efficacy of a 2-week dermatology elective in promoting diagnostic skills and to ascertain the preservation of the acquired expertise, kodachrome slide-based multiple-choice examinations were administered to 84 sixth year medical students at the beginning (pre-test) and completion (post-test) of the elective. The long-term retention of diagnostic skills was evaluated by re-testing 4-9 months after completion of the elective (follow-up test). RESULTS: The mean scores of correct answers at the pre- and post-test were 39.73% and 72.46%, respectively. The mean score at the follow-up test for students with a previous dermatology elective was 80.22%, compared with a score of 46.00% for students who did not participate in the elective. CONCLUSIONS: The 2-week dermatology elective significantly improved the diagnostic skills of the participants, and the knowledge obtained during the elective was retained for at least 4-9 months.

Clinical Clerkship↗
PubMed2003

Interviewing and case presentations in the presence of patients in undergraduate psychiatry: an experiment.

A project to teach psychiatry to medical students in a protected workshop is described. The aim was to provide extended exposure to mental illness in the community but also for the students to present their findings to their peers and teacher in the presence of the patient. From a content analysis of the comments of the students and the patients, it emerges that while the experience was a positive one overall, the students were uncomfortable asking personal questions, and had particular difficulty presenting the patient's mental state and diagnosis in the patient's presence. Many of the patients were ultra-orthodox Jews and the conditions of the interviews often caused them religious concern. The experience was important for its emphasis on communication, and the feedback from the students and patients succeeded in identifying areas for change, such as accommodating religious concerns, and discussing with the patient sensitive issues such as the meaning of a diagnosis of schizophrenia.

Clinical Competence↗
PubMed2003

Shortened course of antibacterial therapy for acute otitis media.

Acute otitis media (AOM) is the most frequent bacterial disease and leading cause of antibacterial prescriptions in infants and children. Although AOM resolves spontaneously in most patients, antibacterial treatment is believed to be indicated in most industrial countries, particularly for infants, to prevent severe complications and relieve symptoms more rapidly. The classical duration of oral antibacterial therapy has been 10 days. During the last decade, the efficacy of shortened course antibacterial therapy has been demonstrated in many trials. Advantages of shorter treatment periods include less expense, better compliance, and potentially less impact on the commensal flora. However, short course antibacterial therapy may not be appropriate for children <2 years of age, particularly those attending daycare centers, those with otorrhea or a recent episode (<1 month), and otitis-prone children. Reasons for a poorer efficacy in these groups of children are still not completely understood.

Acute Disease↗
PubMed2002

Variables influencing bacteriological outcome in patients with streptococcal tonsillopharyngitis treated with penicillin V.

UNLABELLED: Despite the fact that group A streptococci (GAS) remain susceptible to penicillin V (pen V), an increasing rate of bacteriological treatment failures has occurred. A recent study has suggested that the major variables associated with pen V treatment failures were the number of days ill prior to initiation of treatment (<2 days) and age <6 years. In order to study the link between pen V treatment failures and individual variables, we reviewed the files of all children enrolled in four randomised multicentre trials of oral antibiotic therapy, carried out from 1993 to 1999. A standard protocol and follow-up examination were used in these four studies: cultures were obtained 4 days and 1 month after completion of treatment. Total DNA restriction fragment length polymorphism was used to compare pre- and post-treatment GAS isolates. We enrolled 1560 children aged 3 to 12 years, 685 received a 10 day pen V regimen (45 mg/kg per day divided into three doses/day), among them 536 were assessable for bacteriological efficacy at the first and second follow-up visit. We found the only variable associated with penicillin treatment failure was the age of the child when infected. The rate of failure was statistically more important for children younger than 6 years (35.5%, 95% CI 29.9--41.1) than for older children (21.9%, 95% CI 16.9-26.9). CONCLUSION: in this study only young age (<6 years) increases penicillin V treatment failures for group A streptococcal tonsillopharyngitis. This may lead to different antibiotic regimens and follow-up modalities for these targeted patients.

Adolescent↗