PubMed Health⌕ Search

Biomedical subjects

David Schwartz

Publications and source records attributed to David Schwartz.

35 records · Page 2Linked to original sources
PubMed2003

Harsh parenting in relation to child emotion regulation and aggression.

This study presents a model of harsh parenting that has an indirect effect, as well as a direct effect, on child aggression in the school environment through the mediating process of child emotion regulation. Tested on a sample of 325 Chinese children and their parents, the model showed adequate goodness of fit. Also investigated were interaction effects between parents' and children's gender. Mothers' harsh parenting affected child emotion regulation more strongly than fathers', whereas harsh parenting emanating from fathers had a stronger effect on child aggression. Fathers' harsh parenting also affected sons more than daughters, whereas there was no gender differential effect with mothers' harsh parenting. These results are discussed with an emphasis on negative emotionality as a potentially common cause of family perturbations, including parenting and child adjustment problems.

Adjustment Disorders↗
PubMed2003

Streptococcus bovis revisited: a clinical review of 81 bacteremic episodes paying special attention to emerging antibiotic resistance.

Following 2 Cases of Streprococcus bovis endocarditis with a high level of resistance to clindamycin during 2002, the authors reviewed their clinical experience with S. bovis bacteremia during 2 periods, starting in 1980. 81 episodes of S. bovis bacteremia represented approximately 1% of all episodes of bacteremia. In 32 (40%) cases the bacteremia represented endocarditis, in 15 (19%) the bacteremia originated from sick bowel, 11 (14%) were suspected to arise from urinary tract infection, 10 (12%) originated from biliary or peritoneal infection, and 13 from other or unknown sources. 25 (31%) of the bacteremias were polymicrobial. All of the isolates were highly susceptible to penicillin and clindamycin, with the following exceptions: 2 isolates had a minimal inhibitory concentration (MIC) of 0.5 mg/l to penicillin (in 1997) and 5 isolates had an MIC of > 2 mg/l to clindamycin (in 1997, 1998, 2000 and 2002). The 2 most recent of these 5 had high-level resistance to clindamycin of > 256 mg/l. It seems that clindamycin resistance in S. bovis is an emerging phenomenon, in contrast to penicillin resistance, high levels of which have not yet been described in S. bovis.

Age Distribution↗
PubMed2003

Occurrence and phenotypic characteristics of extended-spectrum beta-lactamases among members of the family Enterobacteriaceae at the Tel-Aviv Medical Center (Israel) and evaluation of diagnostic tests.

We assessed the prevalence and phenotypic characteristics of extended-spectrum beta-lactamase (ESBL) producers among cefuroxime-resistant (CXM-R) (MIC > or = 32 micro g/ml) members of the family Enterobacteriaceae in our institution. The 438 CXM-R clinical isolates obtained from nonurine sources among inpatients were screened. ESBL production was confirmed by disk diffusion assay using cefpodoxime (CPD), cefotaxime (CTX), and ceftazidime (CTZ) with and without clavulanate (CLAV). A difference of > or =5 mm in the size of the zone of inhibition in the presence of CLAV for at least one of the agents was considered representative of the ESBL phenotype: 186 isolates (42.5%) were confirmed as ESBL producers. The isolates tested and the rates of ESBL producers were as follows: Klebsiella spp. (n = 81), 79%; Proteus spp. (n = 58), 62%; Escherichia coli (n = 64), 53%; Enterobacter spp. (n = 69), 42%; Serratia spp. (n = 70), 14%; Citrobacter spp. (n = 25), 24%; Providencia spp. (n = 21), 24%; Morganella spp. (n = 41), 5%; and Kluyvera (n = 3), 0%. The overall sensitivity of isolated ESBL confirmatory tests was 79% for CPD-CLAV, 66% for CTZ-CLAV, and 91% for CTX-CLAV. Sensitivities of CTZ-CLAV confirmatory tests for Klebsiella spp., Proteus spp., E. coli, and Enterobacter spp. were 84, 22, 76, and 62%, respectively, and those for CTX-CLAV were 95, 97, 94, and 83%, respectively. They were 90% for CPD-CLAV and CTZ-CLAV, 95% for CPD-CLAV and CTX-CLAV, and 100% for CTZ-CLAV and CTX-CLAV. ESBL production was highly prevalent among Enterobacteriaceae. Using resistance to CXM as an ESBL screening criterion is a suitable option in high-incidence areas where Klebsiella spp. are not the dominant ESBL producers. This screening criterion may simplify the screening test and improve its sensitivity, although at the price of testing more isolates. The CTX-CLAV combination confirmed ESBL producers better than the CTZ-CLAV combination, with sensitivity varying between species. Combined CTZ-CLAV and CTX-CLAV testing detected all these strains; CPD-CLAV provided no additional benefit.

Anti-Bacterial Agents↗
PubMed2003

Infection of a ventriculoatrial shunt with phenotypically variable Staphylococcus epidermidis masquerading as polymicrobial bacteremia due to various coagulase-negative Staphylococci and Kocuria varians.

The diagnosis of bloodstream infection with coagulase-negative staphylococci is frequently based on the isolation of the same organism from more than one blood culture. Phenotypic variation is a common characteristic of pathogenic strains of Staphylococcus epidermidis which may affect species identification by the microbiology laboratory. We describe a patient with a new onset of nephritis and gram-positive bacteremia. Gram-positive cocci grew in multiple blood cultures and were identified by the Vitek 2 system as Kocuria varians, Staphylococcus hyicus, and S. epidermidis. Bacterial isolates grew on blood agar and Congo red agar plates as two distinct morphotypes and exhibited phenotypic variation. Neither morphotype could be identified by the API-Staph assay. Cellular fatty acid analysis identified one of the morphotypes as S. epidermidis but could not identify the other morphotype. All isolates were found to be identical by pulsed-field gel electrophoresis, and both colonial morphotypes were identified as S. epidermidis by 16S ribosomal gene sequencing. Phenotypic variation of S. epidermidis may affect identification to the species level by phenotype-based identification systems. Caution should be exercised when differentiating between true infection and contamination based on strain identification.

Actinomycetales↗
PubMed2003

The enhancer of decapping proteins, Edc1p and Edc2p, bind RNA and stimulate the activity of the decapping enzyme.

A major pathway of eukaryotic mRNA turnover initiates with deadenylation, which allows a decapping reaction leading to 5'-3' exonucleolytic degradation. A key control point in this pathway is the decapping of the mRNA. Two proteins, Edc1 and Edc2, were genetically identified previously as enhancers of the decapping reaction. In this work, we demonstrate that Edc1p and Edc2p are RNA-binding proteins. In addition, recombinant Edc1p or Edc2p stimulates mRNA decapping in cell-free extracts or with purified decapping enzyme. These results suggest that Edc1p and Edc2p activate decapping directly by binding to the mRNA substrate and enhancing the activity of the decapping enzyme. Interestingly, edc1Delta strains show defects in utilization of glycerol as a carbon source and misregulation of several mRNAs in response to carbon-source changes. This identifies a critical role for decapping and Edc1p in alterations of gene expression in response to carbon-source changes.

Endoribonucleases↗
PubMed2002

Reappraisal of community-acquired bacteremia: a proposal of a new classification for the spectrum of acquisition of bacteremia.

In recent years, dramatic changes in health care systems have shifted much of the care of sick individuals from hospitals to the community. Consequently, infections traditionally classified as community-acquired or hospital-acquired infections cannot now be readily classified into either category. We thus propose a new classification based on a wider spectrum of acquisition. A total of 1028 episodes of bloodstream infection (BSI) were divided into 5 categories: true community-acquired infections (370 episodes [36%]), infections in recently discharged patients (110 [11%]), infections associated with invasive procedures performed just before or at the time of admission (56 [5%]), infections in patients admitted from nursing homes (68 [7%]), and hospital-acquired infections (424 [41%]). Thus, 234 (39%) of the 604 bloodstream infections traditionally defined as community acquired were reclassified into 3 newly defined groups, each of which has distinct epidemiologic, clinical, and bacteriologic characteristics, as well as distinct antimicrobial susceptibility profiles. There is a conceptual and practical need for such a new classification.

Aged↗
PubMed2002

Standardized Uptake Values in 2-Deoxy-2-[18F]Fluoro-D-Glucose with Positron Emission Tomography. Clinical Significance of Iterative Reconstruction and Segmented Attenuation Compared with Conventional Filtered Back Projection and Measured Attenuation Correction.

PURPOSE: To evaluate the clinical significance of differences in 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) lymph node standardized uptake values (SUV) in human immunodeficiency virus (HIV) infection using iterative reconstruction with segmented attenuation correction (IR SAC) compared to filtered back-projection with measured attenuation correction (FBP MAC). PROCEDURES: Seven patients with HIV infection and multiple focal lymph node abnormalities were investigated with whole-body FDG-PET. Mean and maximum SUVs from lymph node regions of interest (n = 961) were compared for quantitative differences between reconstruction techniques. RESULTS: IR MAC resulted in significantly lower mean SUV [0.06; 95% (confidence interval (CI)) = 0.04-0.07] and maximum SUV (0.82; 95% CI = 0.77-0.88) values compared to FBP MAC. With IR, segmentation of attenuation correction (AC) resulted in significantly higher mean SUV (0.12; 95% CI = 0.11-0.13) and maximum SUV (0.21; 95% CI = 0.18-0.23) values compared to IR MAC. The overall effect of both IR and SAC was a slight but significant increase in mean SUV (0.06; 95% CI = 0.06-0.08; bias = 2.1%) and a significant decrease in maximum SUV (0.62; 95% CI = 0.56-0.67) compared to FBP MAC. CONCLUSIONS: With our reconstruction parameters, significant differences in mean and maximum SUV values were observed. The magnitude of the mean SUV difference, however, was small. IR SAC is a promising method to accurately quantify standardized uptake values for clinical use.

Journal Article↗
PubMed2002

Victimization in South Korean children's peer groups.

This study reports a cross-sectional investigation of the behavioral, academic, and psychosocial correlates of victimization in South Korean children's peer groups. The participants were 122 children (66 boys, 56 girls; from 10-12-years-old) recruited from a primary school in Seoul, South Korea. Multi-informant assessments (peer nominations, teacher ratings, and self-reports) of peer victimization, social behavior, loneliness/social dissatisfaction, and academic functioning were obtained. Multivariate analyses indicated that peer victimization was associated with poor academic adjustment, loneliness, submissive-withdrawn behavior, aggression, and low levels of assertive-prosocial behavior. These findings suggest that there is considerable similarity in the social processes underlying peer group victimization across South Korean and Western cultural settings.

Aggression↗
PubMed2002

The origin, fate, and health effects of combustion by-products: a research framework.

Incomplete combustion processes can emit organic pollutants, metals, and fine particles. Combustion by-products represent global human and environmental health challenges that are relevant not only in heavily industrialized nations, but also in developing nations where up to 90% of rural households rely on unprocessed biomass fuels for cooking, warmth, and light. These issues were addressed at the Seventh International Congress on Combustion By-Products, which convened 4-6 June 2001 in Research Triangle Park, North Carolina. This congress included a diverse group of multidisciplinary researchers and practitioners who discussed recent developments and future goals in the control of combustion by-products and their effects of exposure on human and ecologic health. Participants recommended that interdisciplinary, coordinated research efforts should be focused to capitalize on the important potential synergisms between efforts to reduce the adverse human health effects linked to exposures to combustion by-products and broader efforts to reduce greenhouse gas emissions and save energy through efficiency. In this article we summarize the principal findings and recommendations for research focus and direction.

Bioelectric Energy Sources↗
PubMed2002

Listeria monocytogenes infection in Israel and review of cases worldwide.

Listeria monocytogenes, an uncommon foodborne pathogen, is increasingly recognized as a cause of life-threatening disease. A marked increase in reported cases of listeriosis during 1998 motivated a retrospective nationwide survey of the infection in Israel. From 1995 to 1999, 161 cases were identified; 70 (43%) were perinatal infections, with a fetal mortality rate of 45%. Most (74%) of the 91 nonperinatal infections involved immunocompromised patients with malignancies, chronic liver disease, chronic renal failure, or diabetes mellitus. The common clinical syndromes in these patients were primary bacteremia (47%) and meningitis (28%). The crude case-fatality rate in this group was 38%, with a higher death rate in immunocompromised patients.

Adolescent↗
PubMed2002

Aurintricarboxylic acid attenuates intimal thickening after balloon injury of the rabbit aorta.

Injury to the arterial wall initiates a cascade of events including platelet deposition and an increase in procoagulant activity of the vessel wall that is associated with intimal thickening and vascular wall remodeling. This study was designed to characterize the effects of aurintricarboxylic acid (ATA), an inhibitor of von Willebrand factor function, on vascular procoagulant activity and the development of intimal thickening after balloon-induced injury to the rabbit aorta. Treatment with ATA, aspirin, or the combination of agents at doses that attenuated platelet aggregation decreased platelet deposition and procoagulant activity bound to the vessel wall after injury. Treatment with ATA reduced the intimal thickening observed 2 weeks after injury. Surprisingly, aspirin treatment had no effect on intimal thickening. These data indicate that inhibition of platelet deposition, while it is able to attenuate local thrombin elaboration, is not alone sufficient to attenuate subsequent intimal thickening that occurs in response to arterial injury.

Angioplasty, Balloon↗
PubMed2000

Friendship as a moderating factor in the pathway between early harsh home environment and later victimization in the peer group. The Conduct Problems Prevention Research Group.

Two prospective investigations of the moderating role of dyadic friendship in the developmental pathway to peer victimization are reported. In Study 1, the preschool home environments (i.e., harsh discipline, marital conflict, stress, abuse, and maternal hostility) of 389 children were assessed by trained interviewers. These children were then followed into the middle years of elementary school, with peer victimization, group social acceptance, and friendship assessed annually with a peer nomination inventory. In Study 2, the home environments of 243 children were assessed in the summer before 1st grade, and victimization, group acceptance, and friendship were assessed annually over the next 3 years. In both studies, early harsh, punitive, and hostile family environments predicted later victimization by peers for children who had a low number of friendships. However, the predictive associations did not hold for children who had numerous friendships. These findings provide support for conceptualizations of friendship as a moderating factor in the pathways to peer group victimization.

Child↗
PubMed1987

Long term effects of a systems-oriented school prevention program.

This study documents three-year effects of a grade school systems-oriented primary prevention program based on the Yale Child Study Center model. Follow-up indicated that children receiving the intervention performed significantly better on various indices, mainly academic. Implications of these findings are discussed.

Achievement↗