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Biomedical subjects

E Bernstein

Publications and source records attributed to E Bernstein.

At least 19 recordsLinked to original sources
PubMed2006

Structural transition in rare earth oxide clusters.

Size effects, such as structure transition, have been reported in small clusters of alkali halide compounds. We extend the study to rare earth sesquioxide (Gd(2)O(3)) clusters which are as ionic as the alkali halide compounds, but have a more complicated structure. In a clean and controlled environment (ultra high vacuum), such particles are well crystallized, facetted and tend to adopt a rhombic dodecahedron shape. This indicates the major role of highly ionic bonds in preserving the crystal lattice even at small sizes (a few lattice parameter). Based on both cathodo-luminescence and transmission electron microscopy, we report the existence of a structural transition from bcc to monoclinic at small sizes.

Journal Article↗
PubMed2004

Synthesis and properties of europium-based phosphors on the nanometer scale: Eu2O3, Gd2O3:Eu, and Y2O3:Eu.

Nanocrystals of oxides containing europium as the main constituent or as a doping element in RE2O3 ( RE=Y, Gd) have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by high-resolution TEM, absorption spectroscopy, and luminescence spectroscopy. The samples obtained consisted of concentrated and colloidally stable suspensions of luminescent oxide nanoparticles with an average grain diameter in the range 2-5 nm. The nanoparticles were found to be highly crystalline despite their ultrasmall size and the low temperature of 180 degrees C applied during the synthesis. Upon UV excitation, the red luminescence relative to the 5D0-->7Fn transition within the cubic form of RE2O3 exhibits some important differences from that usually found in bulk materials.

Journal Article↗
PubMed2001

Dicer functions in RNA interference and in synthesis of small RNA involved in developmental timing in C. elegans.

Double-stranded RNAs can suppress expression of homologous genes through an evolutionarily conserved process named RNA interference (RNAi) or post-transcriptional gene silencing (PTGS). One mechanism underlying silencing is degradation of target mRNAs by an RNP complex, which contains approximately 22 nt of siRNAs as guides to substrate selection. A bidentate nuclease called Dicer has been implicated as the protein responsible for siRNA production. Here we characterize the Caenorhabditis elegans ortholog of Dicer (K12H4.8; dcr-1) in vivo and in vitro. dcr-1 mutants show a defect in RNAi. Furthermore, a combination of phenotypic abnormalities and RNA analysis suggests a role for dcr-1 in a regulatory pathway comprised of small temporal RNA (let-7) and its target (e.g., lin-41).

Alleles↗
PubMed2001

Role for a bidentate ribonuclease in the initiation step of RNA interference.

RNA interference (RNAi) is the mechanism through which double-stranded RNAs silence cognate genes. In plants, this can occur at both the transcriptional and the post-transcriptional levels; however, in animals, only post-transcriptional RNAi has been reported to date. In both plants and animals, RNAi is characterized by the presence of RNAs of about 22 nucleotides in length that are homologous to the gene that is being suppressed. These 22-nucleotide sequences serve as guide sequences that instruct a multicomponent nuclease, RISC, to destroy specific messenger RNAs. Here we identify an enzyme, Dicer, which can produce putative guide RNAs. Dicer is a member of the RNase III family of nucleases that specifically cleave double-stranded RNAs, and is evolutionarily conserved in worms, flies, plants, fungi and mammals. The enzyme has a distinctive structure, which includes a helicase domain and dual RNase III motifs. Dicer also contains a region of homology to the RDE1/QDE2/ARGONAUTE family that has been genetically linked to RNAi.

Animals↗
PubMed2001

The rest is silence.

Over the past several years, RNAi and its related phenomena have emerged not only as a powerful experimental tool but also as a new mode of gene regulation. Through a combination of genetic and biochemical approaches we have learned much about the mechanisms underlying dsRNA responses. However, many of the most intriguing aspects of dsRNA-induced gene silencing have yet to be illuminated. What has become abundantly clear is that the complex and highly conserved biology underlying RNA interference is critical both for genome maintenance and for the development of complex organisms. However, it seems probable that we have only begun to reveal the diversity of biological roles played by RNAi-related processes.

Animals↗
PubMed2000

An RNA-directed nuclease mediates post-transcriptional gene silencing in Drosophila cells.

In a diverse group of organisms that includes Caenorhabditis elegans, Drosophila, planaria, hydra, trypanosomes, fungi and plants, the introduction of double-stranded RNAs inhibits gene expression in a sequence-specific manner. These responses, called RNA interference or post-transcriptional gene silencing, may provide anti-viral defence, modulate transposition or regulate gene expression. We have taken a biochemical approach towards elucidating the mechanisms underlying this genetic phenomenon. Here we show that 'loss-of-function' phenotypes can be created in cultured Drosophila cells by transfection with specific double-stranded RNAs. This coincides with a marked reduction in the level of cognate cellular messenger RNAs. Extracts of transfected cells contain a nuclease activity that specifically degrades exogenous transcripts homologous to transfected double-stranded RNA. This enzyme contains an essential RNA component. After partial purification, the sequence-specific nuclease co-fractionates with a discrete, approximately 25-nucleotide RNA species which may confer specificity to the enzyme through homology to the substrate mRNAs.

Animals↗
PubMed1999

Pulsed dye laser therapy for sun damaged skin.

OBJECTIVE: The objective of this study was to evaluate the effectiveness of the pulsed dye laser (585 nm, 450 ms) in the treatment of sun induced wrinkles. DESIGN: Patients had one pulsed dye laser (585 nm) treatment. The treated areas were assessed by the following methods: grading of skin wrinkles at 6 weeks, 12 weeks, and 6-14 months after treatment by blinded observers and by light and electron microscopy. SETTING: An ambulatory care center at Abbott Northwestern Hospital (ANH) and the Laser & Skin Surgery Center of Northern California (LSSCNC). PATIENTS: Twenty patients were treated, half with mild to moderate and half with moderate to severe sun induced skin wrinkles. RESULTS: At last follow up 90% (9/10) of the mild to moderate wrinkles and 40% (4/10) of the treated patients with moderate to severe wrinkles had clinically observable improvement in their sun induced skin wrinkles. Histologic examinations of the treated areas showed a superficial dermal band of well organized elastin and collagen fibers replacing pre-treatment elastic tissue. Increased cellularity and mucin deposition was consistent with dermal collagen remodeling.

Adult↗
PubMed1999

Immune response to influenza vaccination in a large healthy elderly population.

Elderly individuals not only demonstrate a greater risk of morbidity and mortality from influenza than the young, but also have greater difficulty mounting a protective response to influenza vaccine. The mechanism of the decreased efficacy of influenza vaccination in the elderly is not well understood. The present study was designed to assess the interaction between cell-mediated and humoral immune responses to influenza vaccine in a large population (n = 233) of healthy elderly individuals (mean age = 80.7) living in six continuing care retirement communities (CCRCs). While influenza vaccination resulted in significant increases in the mean anti-influenza antibody titres and mean proliferative responses of peripheral blood mononuclear cells to purified subvirion trivalent influenza vaccine one month after vaccination, only 48.9% and 30.0% of subjects had intact humoral and cell-mediated immune responses, respectively. No association was observed between intact cell-mediated and humoral responses: 14.7% of subjects had an intact cell-mediated, but not humoral response, and 32.6% of subjects had an intact humoral, but not cell-mediated response. However, IFNgamma production was significantly correlated with both antibody and cell-mediated responses to influenza vaccination, a finding not previously reported in the elderly. These results indicate that there is considerable heterogeneity among immune responses of the elderly to influenza vaccination. This heterogeneity needs to be a major consideration in evaluation of new vaccine preparations.

Aged↗
PubMed1999

Sabbatical programs and the status of academic emergency medicine: a survey.

OBJECTIVES: The Society for Academic Emergency Medicine (SAEM) commissioned a survey in 1998 to describe sabbatical programs, academic rank, and tenure, and to shed light on factors affecting the continuum of faculty development, as a context for evaluating the potential importance of emergency medicine (EM) sabbatical programs. METHODS: The chairs of 120 EM residency programs were surveyed. RESULTS: The response rate was 90%. Of 108 responses, 44 were academic EM departments (AEMDs); ten were their affiliates. The setting was urban for 82%; 37% were publicly funded and 58% privately. AEMDs were more likely to have a tenure track and eligibility for a sabbatical program, but not more likely to use a sabbatical program. Among 2,042 ranked EM faculty, there were 121 professors and 346 associate professors. Mean sabbatical length was six months, provided at full pay requiring a mean of 5.7 years of employment. Among 39 programs reporting eligibility for an EM sabbatical, requirements included: tenure (43%), academic rank of associate professor (78%), an application with multiple approval levels (92%), and a formal report (75%). Thirteen EM programs used sabbaticals; only 40 faculty members altogether (9% of senior faculty) have taken sabbaticals. The mean value of sabbaticals (rated by users on a scale of 1 to 10) was 6.8. Reduced funding, lack of departmental status, difficulty retaining faculty, Health Care Financing Administration (HCFA) regulations, graduate medical education (GME) cutbacks, and no release time were identified as challenges for emergency physicians (EPs) wishing to participate in sabbaticals. Strategies proposed to overcome these obstacles include quality customer service, streamlined operations, outside contracts, computerization, hiring individuals with PhDs, collaboration, political activity, and faculty development. CONCLUSIONS: A sabbatical can be beneficial for individuals and their institutions, but presently EPs have not been able to maximize use of available opportunities. Some obstacles to successful participation of EM in sabbatical programs might be overcome with creative strategies and the active support of professional academic organizations.

Career Mobility↗
PubMed1998

Behavioral risk factors in emergency department patients: a multisite survey.

BACKGROUND: Many people rely on EDs for routine health care. Often, however, screening and counseling for health risks are not provided. OBJECTIVE: To determine prevalence rates of chronic disease and injury risk factors and access to routine health care in a random sample of ED patients in 3 cities. METHODS: A prospective survey was conducted at 3 hospital EDs in Akron, OH, Boston, MA, and Denver, CO. A modified version of the national Behavioral Risk Factor Surveillance Survey was administered by trained researchers to a convenience sample of non-critically ill patients during randomly selected shifts. RESULTS: Of 1,143 eligible patients, 923 (81%) agreed to participate. Their mean age was 39 (range = 17-96) years. Most were female (58%), white (60%), and unmarried (68%). Thirty-eight percent had no access to primary care. Injury-prone behaviors were prevalent: 53% of the respondents did not wear seat belts regularly; 15% had no working smoke detector; 3% kept loaded, unlocked handguns in their homes; 11% had attempted suicide; 23% had a positive CAGE screen for alcoholism; 3% had operated a motor vehicle in the preceding month while alcohol-intoxicated; and 11% had ridden in an automobile with an intoxicated driver. Cancer and chronic disease risks were also common: 48% smoked; 16% had not received a blood pressure check in the preceding year; and 4% reported unsafe sexual practices. Among women aged > 50 years, 42% had not received a Pap test in the prior 2 years and 14% had never had mammography. Many prevalence rates and access to care varied among the 3 sites. However, for most risk factors, prevalence rates did not differ in patients with and without access to primary health care. CONCLUSIONS: ED patients have high rates of injury and chronic disease risks, and many have no other source of routine health care. Research is needed to determine whether ED-based programs, designed to reduce injury and chronic disease risks, are feasible and cost-effective.

Adolescent↗
PubMed1998

Patients with alcohol problems in the emergency department, part 1: improving detection. SAEM Substance Abuse Task Force. Society for Academic Emergency Medicine.

Medical and social problems related to alcohol use are frequently seen in the ED. Often, the tempo of emergency medicine practice seems to preclude assessment beyond that required by the acute complaint. However, detection of ED patients with alcohol problems can occur using brief screening tools. This article was developed by members of the SAEM Substance Abuse Task Force, and describes screening tools that have been used successfully to identify at-risk and dependent drinkers. Their brevity, reproducibility, and accuracy vary somewhat, but screening can be realistically performed in the busy ED setting. The early detection of patients with alcohol problems would provide the opportunity for early intervention, and may reduce subsequent morbidity and mortality in this patient population.

Adult↗
PubMed1998

Patients with alcohol problems in the emergency department, part 2: intervention and referral. SAEM Substance Abuse Task Force. Society for Academic Emergency Medicine.

Early intervention and appropriate referral of patients with alcohol problems have the potential to reduce alcohol-related morbidity and mortality. Part 1 of this series introduced screening tools that can be applied in the ED to allow early detection of at-risk drinkers. This article was developed by members of the SAEM Substance Abuse Task Force and describes assessment and intervention techniques once the at-risk or dependent drinkers has been identified. Appropriate aftercare and referral of patients found to have alcohol problems are also discussed.

Alcoholism↗
PubMed1997

Project ASSERT: an ED-based intervention to increase access to primary care, preventive services, and the substance abuse treatment system.

STUDY OBJECTIVE: To test the feasibility and effectiveness of Project ASSERT, an innovative program developed by us to facilitate access to the substance abuse treatment system and to primary care and preventive services for emergency department patients with drug- and alcohol-related health problems. METHOD: Multicultural health promotion advocates (HPAs) were trained by ED personnel to screen patients using a health needs history, to administer a brief negotiated interview based on readiness-to-change principles, and to use an active referral process to capture the marginal capacity of the substance abuse treatment system. Outcome measures included (1) number of referrals to the substance abuse treatment system, (2) patient self-report of satisfaction with services received from Project ASSERT and utilization of treatment resources, and (3) changes in self-reported frequency of drug and alcohol use and in Drug Abuse Screening Test scores between enrollment and follow-up at 60 to 90 days. RESULTS: Between March 1, 1995, and February 29, 1996, 7,118 adult ED patients were screened. Substance abuse was detected among 2,931 patients (41%), and 1,096 (37% of detected patients) were enrolled. A total of 8,848 referrals were made: 3,189 to primary care, 2,018 to a variety of substance abuse treatment services, 2,253 for smoking cessation, 339 for mammography, and 689 to other support services (eg, psychiatric nurse, social worker, battered women's advocate or shelter). Comparison of enrollment and follow-up scores for the 245 enrollees who kept a follow-up appointment demonstrated significant reductions, including a 45% reduction in severity of drug problem, a 56% reduction in alcohol use, and a 64% reduction in the frequency of drinking six or more drinks at one sitting. At follow-up, patients expressed satisfaction with Project ASSERT: 91% were satisfied with their referrals; 93% thought the HPAs explained things well; and 99% thought the HPAs respected them as individuals. Among the follow-up group, 50% self-reported that they had kept an appointment for treatment. CONCLUSION: Project ASSERT is an innovative approach to link ED patients with the substance abuse treatment system and with primary care and other preventive services. Its success is further demonstrated by its adoption by Boston Medical Center as a funded ED value-added service.

Adult↗
PubMed1996

An emergency medicine approach to violence throughout the life cycle. SAEM Public Health and Education Committee.

This document by the SAEM Public Health and Education Committee outlines the public health impact of interpersonal violence as it pertains to acute emergency care. This paper provides an overview of violence through the life cycle (i.e., child abuse, youth violence, intimate violence, and elderly abuse). It also makes specific recommendations regarding the role emergency physicians can play in reducing violence through medical education, research, surveillance, public education, advocacy, and clinical practice.

Aged↗