Biomedical subjects

N Bornstein

Publications and source records attributed to N Bornstein.

At least 19 recordsLinked to original sources

PubMed2006

Mannheim carotid intima-media thickness consensus (2004-2006). An update on behalf of the Advisory Board of the 3rd and 4th Watching the Risk Symposium, 13th and 15th European Stroke Conferences, Mannheim, Germany, 2004, and Brussels, Belgium, 2006.

Intima-media thickness (IMT) is increasingly used as a surrogate end point of vascular outcomes in clinical trials aimed at determining the success of interventions that lower risk factors for atherosclerosis and associated diseases (stroke, myocardial infarction and peripheral artery diseases). The necessity to promote further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is expressed through this updated consensus. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is based on physics, technical and disease-related principles as well as agreements on how to perform, interpret and document study results. Harmonization of carotid image acquisition and analysis is needed for the comparison of the IMT results obtained from epidemiological and interventional studies around the world. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from exceptions named, which emphasize that inside randomized clinical trials should be performed. Although IMT has been suggested to represent an important risk marker, according to the current evidence it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of randomized clinical trials incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Adult↗

PubMed2006

Cognitive impairment and carotid atherosclerosis in a general Italian midlife and old population.

The authors describe the design and the general, ultrasonographic, neuropsychological methodology of an observational epidemiological population survey, named REMEMBER (Registry Evaluation Memory in Buttrio e Remanzacco) conducted in the northeast of Italy in a randomized stratified sample of 1,026 subjects (554 F and 472 M) aged 55-98 years. The study was planned as cross-sectional and longitudinal survey of cognitive impairment, cardiovascular risk factors, carotid atherosclerosis in a midlife and older Italian population sample. The objectives of the first phase are to assess the prevalence of the different types of dementia, the cognitive impairment non-dementia, the cardiovascular risk factors, the carotid intima-media thickness and arterial distensibility, and of depression. The conclusions of this study will make it possible to organize preventive and interventional strategies for these epidemic conditions.

Aged↗

PubMed2004

Mannheim intima-media thickness consensus.

Intima-media thickness (IMT) is increasingly used in clinical trials as a surrogate end point for determining the success of interventions that lower risk factors for atherosclerosis. The necessity for unified criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is addressed in this consensus statement. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness of > or =1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is recommended in all epidemiological and interventional trials dealing with vascular diseases to improve characterization of the population investigated. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from few exceptions. Although IMT has been suggested to represent an important risk marker, it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of studies incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.

Arteriosclerosis↗

PubMed2004

Teaching of neuroepidemiology in Europe: time for action.

Many epidemiological and clinical studies in Europe, especially in Eastern Europe and countries in transition, are of poor methodological quality because of lack of background knowledge in clinical epidemiology methods and study designs. The only way to improve the quality of epidemiological studies is to provide adequate undergraduate and/or postgraduate education for the health professionals and allied health professions. To facilitate this process, the European Federation of Neurological Societies (EFNS) Task Force on teaching of clinical epidemiology in Europe was set up in October 2000. Based on analyses of the current teaching and research activities in neuroepidemiology in Europe, this paper describes the Task Force recommendations aimed to improve these activities.

Education, Medical↗

PubMed2001

A history of migraine is not a risk factor to develop an ischemic stroke in the elderly.

OBJECTIVE: To assess the prevalence of migraine in elderly patients hospitalized with ischemic stroke compared with vascular and nonvascular control groups. BACKGROUND: Migraine is a disease with a presumed vascular mechanism. While migraine is a common complaint of young victims of ischemic stroke, it is unclear whether a current or past history of migraine constitutes a risk factor for developing an ischemic stroke in the elderly. METHODS: We obtained current and past headache history from 100 consecutive patients hospitalized with ischemic stroke (aged 60 years or older) and compared the results with 100 patients hospitalized due to acute myocardial infarction and 100 hospitalized patients with no vascular disease. RESULTS: The sex and the age of the patients did not differ among the groups. The lifetime prevalence of migraine (8% of the patients with ischemic stroke, 8% of the nonvascular controls, and 15% of the patients with acute myocardial infarction) or of all types of headaches (27%, 30%, and 15%, respectively), did not differ significantly between the groups. CONCLUSIONS: Based on the reported history, elderly migraineurs are not at increased risk to develop ischemic stroke.

Aged↗

PubMed2000

Seizures after stroke: a prospective multicenter study.

BACKGROUND: Studies of seizures after stroke have largely been retrospective, with small patient numbers and limited statistical analysis. Much of the doctrine about seizures after stroke is not evidenced based. OBJECTIVE: To determine the incidence, outcome, and risk factors for seizures after stroke. DESIGN: International, multicenter, prospective, analytic inception cohort study conducted for 34 months. PATIENTS AND SETTING: There were 2021 consecutive patients with acute stroke admitted to university teaching hospitals with established stroke units. After exclusion of 124 patients with previous epilepsy or without computed tomographic diagnosis, 1897 were available for analysis. Mean follow-up was 9 months. MAIN OUTCOME MEASURES: Occurrence of 1 or more seizures after stroke, stroke disability, and death after stroke. RESULTS: Seizures occurred in 168 (8.9%) of 1897 patients with stroke (28 [10.6%] of 265 with hemorrhagic and 140 [8.6%] of 1632 with ischemic stroke). On Kaplan-Meier survival analysis, patients with hemorrhagic stroke were at significantly greater risk of seizures (P =.002), with an almost 2-fold increase in risk of seizure after stroke (hazard ratio [HR], 1.85; 95% confidence interval [CI], 1.26-2.73; P =.002). On multivariate analysis, risk factors for seizures after ischemic stroke were cortical location of infarction (HR, 2.09; 95% CI, 1. 19-3.68; P<.01) and stroke disability (HR, 2.10; 95% CI, 1.16-3.82; P<.02). The only risk factor for seizures after hemorrhagic stroke was cortical location (HR, 3.16; 95% CI, 1.35-7.40; P<.008). Recurrent seizures (epilepsy) occurred in 47 (2.5%) of 1897 patients. Late onset of the first seizure was an independent risk factor for epilepsy after ischemic stroke (HR, 12.37; 95% CI, 4.74-32.32; P<. 001) but not after hemorrhagic stroke. CONCLUSIONS: Seizures occur more commonly with hemorrhagic stroke than with ischemic stroke. Only a small minority later develop epilepsy. Patients with a disabling cortical infarct or a cortical hemorrhage are more likely to have seizures after stroke; those with late-onset seizures are at greater risk of epilepsy.

Aged↗

PubMed2000

Key points for the development of mouse immunogenicity test as potency assay for acellular pertussis vaccines.

According to WHO and the European Pharmacopoeia, the current potency test for acellular pertussis vaccines is a mouse immunogenicity assay assessing consistency of production from batch to batch. The assay compares the batch under control with a reference vaccine of documented clinical efficacy. This study describes and illustrates critical aspects of the assay, based on our experience on a tricomponent vaccine: validation of immunoassay to quantify mouse antibody response, choice of vaccine immunising doses in the three-doses model, treatment of non-responder mice for calculations, establishment of assay validity criteria.

Animals↗

PubMed2000

Acute neurological stroke care in Europe: results of the European Stroke Care Inventory.

Following the 1997 Recommendations of the EFNS Task Force on Acute Neurological Stroke Care (European Journal of Neurology, 1997: 4:435-441) a European Inventory was undertaken to assess the development of acute stroke care in the EFNS member countries and to give an estimate of the needs based on 1997 data. All 30 members of the EFNS Stroke Scientist Panel were asked to complete a questionnaire on acute stroke epidemiology as well as acute stroke care in their country. Data were based either on national surveys, hospital statistics, or estimates given on the basis of extrapolation of regional studies, or other defined sources. Specialist estimates were also taken into account where no other data source was available. Data from 22 countries were received and referred to almost one million strokes occurring per year in a population of over 500 million. Most epidemiological data confirmed an east-west gap known from previous studies. These included rates that, in eastern countries, were higher for incidence, stroke as a leading cause of death, and 30-day case-fatality, and rates that were lower for overall hospitalization or availability of CT scanning. East-west differences were not seen for the total number of acute stroke units or the number of acute stroke units set up within neurological hospital departments, nor for most other quality indicators of acute stroke care with the exception of technological standards in some countries. The higher rates for 30-day case-fatality in eastern Europe (mostly above 20%) compared with western Europe (mostly below 20%) are probably caused by a case mix with more severe ischemic strokes and a higher percentage of cerebral haemorrhages admitted for acute care in eastern Europe. This is probably due to the higher prevalence of the most common risk factors for stroke in these countries which tend to result in more severe strokes. This, therefore, underlines the need for stroke prevention programmes especially in eastern Europe. This epidemiological east-west gap is not reflected by most quality indicators for acute stroke care, e.g. total number of acute stroke units available within each country. Most eastern European countries have a well-developed neurological care system for acute stroke but still have urgent technological and socioeconomical needs. The leading role of clinical neurology in acute stroke care is visible in most but not all European countries.

Aged↗

PubMed1999

White matter changes in stroke patients. Relationship with stroke subtype and outcome.

White matter changes (WMC), detected by imaging techniques, are frequent in stroke patients. The aim of the study was to determine how WMC relate to stroke subtypes and to stroke outcome. We made a systematic Medline search for articles appearing with two of the following key words: either 'WMC or white matter lesions or leukoencephalopathy or leukoaraiosis' and 'stroke or cerebral infarct or cerebral hemorrhage or cerebrovascular disease or transient ischemic attack (TIA)'. WMC, as defined radiologically, are present in up to 44% of patients with stroke or TIA and in 50% of patients with vascular dementia. WMC are more frequent in patients with lacunar infarcts, deep intracerebral hemorrhages, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and cerebral amyloid angiopathy. After an acute ischemic stroke, WMC are associated with a higher risk of death or dependency, recurrent stroke of any type, cerebral bleeding under anticoagulation, myocardial infarction, and poststroke dementia. WMC in stroke patients are often associated with small-vessel disease and lead to a higher risk of death, and poor cardiac and neurological outcome. However, several questions remain open and need further investigations.

Age Factors↗

PubMed1996

An international investigation of an outbreak of Legionnaires disease among UK and French tourists.

Five cases of legionnaires disease and one death were associated with four members of a tour group from the United Kingdom (UK) and one French tourist who all visited Spain in the spring of 1993. The UK group stayed at four hotels, one of which was also used by the French tourist. Phenotypic and genotypic comparison of isolates of Legionella pneumophila obtained from one of the UK cases and the French patient demonstrated that they were indistinguishable from each other and from environmental isolates obtained from the water supply of the hotel at which all five cases had stayed. A cohort study of the UK tour group was carried out to determine the extent of the outbreak and showed that three further members of the group had respiratory illness but were serologically negative to legionella infection. International participation in this investigation has highlighted the value of a European surveillance scheme and the benefit of microbiological collaboration between legionella reference laboratories in Europe.

Aged↗

PubMed1995

Genomic heterogenicity amongst phenotypically similar Legionella micdadei strains.

Nine unrelated Legionella micdadei strains isolated from clinical and environmental samples have been characterized biochemically, serologically using polyclonal and monoclonal antibodies and by macrorestriction analyses using pulsed-field gel electrophoresis. All strains were positive in the Bromocresol purple spot test and grew as blue colonies on dye-containing media. They were positive for catalase, weakly positive for oxidase, and negative for sodium-hippurate hydrolysis, beta-lactamase and gelatinase. None of the strains showed autofluorescence under long-wave ultraviolet light. A panel of six monoclonal antibodies raised against the ATCC strain TATLOCK revealed no significant differences in the surface antigen composition of the L. micdadei strains. None of these monoclonal antibodies reacted with L. maceachernii and L. longbeachae serogroup 2, the only species that cross-react with polyclonal antisera. Each of the nine L. micdadei strains showed individual restriction patterns of the genomic DNA when using both SfiI and NotI restriction enzymes in the pulsed-field gel electrophoresis. Macrorestriction analysis is a valuable tool for studies on the molecular epidemiology of L. micdadei.

Antibodies, Bacterial↗

PubMed1995

Combined monoclonal antibody typing, multilocus enzyme electrophoresis, soluble protein profiles and plasmid analysis of clinical and environmental Legionella pneumophila serogroup 1 isolated in a Portuguese hospital.

Sixteen strains of Legionella pneumophila serogroup 1 isolated from patients and the environment at Santa Cruz Hospital were examined using four typing methods. Monoclonal antibodies showed that all the isolates belonged to subgroup Pontiac and mainly to subtype Allentown. With multilocus enzyme electrophoresis nine subtypes (ETs) were revealed; each strain had the same profile with electrophoresis of soluble proteins, and plasmid analysis revealed that only two of the strains studied contained plasmids. Among these methods, multilocus enzyme electrophoresis was the most discriminative as a single epidemiological marker. Problems concerning the microbiological examination of environmental specimens and correlation with clinical strains confirmed the difficulty of investigating an outbreak source of legionellosis and the need for careful evaluation of the results.

Antibodies, Monoclonal↗

PubMed1995

Relationship between Legionella spp. and antibody titres at a therapeutic thermal spa in Portugal.

The presence of Legionella spp. in the water of a Portuguese spa was ascertained during the spa season, between May and November. Simultaneously the prevalence of anti-legionella antibodies in people attending the spa was also investigated. The antibody titres of 172 randomly selected patients and 42 therapists were determined, and compared with a control group of 503 blood donors. Legionellae were present in the spa water at low concentrations, generally lower than 10(3) c.f.u./l. A total of 92 strains representing eight different species or serogroups were isolated; the predominant isolates belonged to Legionella pneumophila serogroup 6 and to L. londiniensis. During the study, no clinical cases of Legionnaires' disease were observed, and the antibody titres were generally low in the groups studied. However, the antibody titres of the patients increased slightly during their stay at the spa, approaching the values for the therapists. Mean antibody titres in the groups related with the spa were significantly higher than those in the blood donors against five of the seven legionella antigens tested. The largest number of elevated antibody titres in the exposed groups were to the L. pneumophila sg 5 and sg 6 antigens.

Adult↗

PubMed1994

Clonal study of enterotoxin-B producing strains of Staphylococcus aureus.

Sixty-nine Staphylococcus aureus strains, 39 of which produced staphylococcal enterotoxin B (SEB+) and 14 of which were associated with toxic shock (TS+), were studied using the following markers: serotyping, phage typing, antibiotyping, ribotyping, zymotyping and pulsed-field electrophoresis typing. Analysis of the results showed that the enterotoxin B producing strains were derived from at least three clones: the first two consisted of methicillin-susceptible strains, while the third included the methicillin-resistant (MRSA) strains. TS+ strains of nongenital origin appeared to be distributed between the three clones, with no specific characters.

Bacteriophage Typing↗

PubMed1993

rRNA gene restriction patterns as an epidemiological marker in nosocomial outbreaks of Staphylococcus aureus infections.

rRNA gene restriction patterns (ribotyping) were compared with phage typing, serotyping, enterotoxins and exfoliatin production in the analysis of 26 Staphylococcus aureus strains isolated from two different nosocomial outbreaks. Total DNA was cleaved by EcoRI restriction endonuclease. After agarose gel electrophoresis and Southern transfer, the hybridization of the membranes was done with radiolabelled 16S rRNA gene from Bacillus subtilis inserted into a plasmid vector. Six to 13 fragments were visualized. A core of common fragments was discerned for all strains tested. A full correlation between ribotyping and conventional markers was observed in only one of the outbreaks studied. In both outbreaks, ribotyping proved helpful in characterizing otherwise untypable strains.

Bacterial Typing Techniques↗

PubMed1992

Genotypic and phenotypic methods for the investigation of a nosocomial Legionella pneumophila outbreak and efficacy of control measures.

To determine the source of a nosocomial outbreak of Legionella pneumophila serogroup 1 infection and the efficacy of control measures, clinical and environmental isolates were characterized by molecular subtyping and disease surveillance was conducted. The outbreak involved 32 cases (relative risk, 4.0; P less than .001 vs. previous period). Water colonization with L. pneumophila serogroup 1 and patients' exposure to faucet use incriminated the water system as the environmental source. Monoclonal antibody typing showed that patient isolates belonged mainly to type Pontiac and water isolates mainly to type Bellingham (P less than .001). By four genotypic techniques, outbreak-related isolates from patients and the water system were found to be clonally related and distinct from control strains (P less than .001). Heat and UV light treatment of the water system showed a protective efficacy of 88% (95% confidence interval, 75%-94%). These findings indicate that phenotypic variation may interfere with monoclonal antibody typing of legionellae and that waterborne legionellosis can be controlled by physical disinfection.

Belgium↗

PubMed1992

Synthetic DNA probes for detection of genes for enterotoxins A, B, C, D, E and for TSST-1 in staphylococcal strains.

A dot blot hybridization technique with oligonucleotide probes was developed for the specific detection of the TSST-1 gene and the staphylococcal enterotoxin (SE) genes A, B, C, D and E. For each toxin gene a probe sequence was chosen from the previously determined sequence. A total of 145 staphylococcal strains (133 Staphylococcus aureus and 12 coagulase-negative staphylococci (CNS) were studied by this genotypic method and by two phenotypic assays (gel immunodiffusion and ELISA). An excellent correlation (96%) was observed between the genotypic and phenotypic assays. DNA from two CNS strains hybridized with a probe without detection of the corresponding toxin (SEB for one strain and SEC for the other strain). One Staph. aureus strain was shown to be an SEC producer, but was not detected by the corresponding probe. Gene probe and immunological assays seem to be complementary methods for studies of staphylococcal strains producing (or potentially producing) TSST-1 or enterotoxins.

Bacterial Toxins↗

PubMed1992

Detection of Legionella spp. in bronchoalveolar lavage fluids by DNA amplification.

By using Taq polymerase, DNA amplification of a specific fragment of the macrophage infectivity potentiator (mip) gene from Legionella pneumophila was used to detect Legionella spp. in bronchoalveolar lavage (BAL) fluid specimens. We were able to detect DNAs from all 30 L. pneumophila strains tested (serogroups 1 to 14), L. micdadei, and L. bozemanii serogroup 1. DNA from bacteria of other species tested and DNA from human leukocytes were not amplified by this procedure. After optimization of the conditions for DNA extraction from BAL fluid, a 2-ml sample of BAL fluid seeded with 25 CFU/ml tested positive after DNA amplification. A total of 68 frozen BAL fluid specimens sent to the laboratory because of suspected legionellosis were tested in a retrospective study. The eight culture-positive samples were all positive after specific DNA amplification. Among 60 culture-negative samples, 7 were positive after amplification. Of these seven samples, four were from patients who had presented a typical clinical history of legionellosis; the samples had antibody titer increases of 2 dilutions. For the three remaining samples, serological diagnosis of legionellosis in the patients from whom the samples were obtained could not be documented, and although the causative agent of these pulmonary infections was not determined, the clinical features of the patients were in accordance with legionellosis.

Bacteriological Techniques↗