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PubMed1996

Regulation of the double-stranded RNA-dependent protein kinase PKR by RNAs encoded by a repeated sequence in the Epstein-Barr virus genome.

During the initial infection of B lymphocytes by Epstein-Barr virus (EBV) only a few viral genes are expressed, six of which encode the EBV nuclear antigens, EBNAs 1-6. The majority of EBNA mRNAs share common 5'-ends containing a variable number of two alternating and repeated exons transcribed from the BamHI W major internal repeats of the viral DNA. These sequences can also exist as independent small RNA species in some EBV-infected cell types. We present evidence that transcripts from these W repeat regions can exert a trans-acting effect on protein synthesis, through their ability to activate the dsRNA-dependent protein kinase PKR. UV cross-linking and filter binding assays have demonstrated that the W transcripts bind specifically to PKR and can compete with another EBV-encoded small RNA, EBER-1, which was shown previously to bind this kinase. In the reticulocyte lysate system the W RNAs shut off protein synthesis through an ability to activate PKR. In contrast to EBER-1, the W RNAs are unable to block the dsRNA-dependent activation of PKR. Using a purified preparation of the protein kinase we have shown that the W transcripts directly activate PKR in vitro. The results suggest that EBV has the ability both to activate and to inhibit PKR through the actions of different products of viral transcription.

Base Sequence↗

PubMed1988

Measuring hospital competition.

This paper appraises the use of the Herfindahl market share index as an exogenous competition variable in empirical studies of the hospital sector. An analysis of cross-sectional Florida data shows that this index itself is significantly influenced by the demand and supply factors commonly included in econometric models of hospital performance. The analysis then illustrates that biased inferences about the effects of market competition on the costs of hospital care may result unless the values of the Herfindahl Index are treated endogenously in hospital cost models.

Costs and Cost Analysis↗

PubMed1987

Idiotype-anti-idiotype interactions of VHIX-coded anti-progesterone and anti-arsonate antibodies. Comparison of passive haemagglutination and radioimmunoassays.

The reactivity and specificity of polyclonal and monoclonal anti-idiotypic antibodies raised against monoclonal anti-progesterone and anti-arsonate antibodies have been studied by solid phase radioimmunoassay (RIA) with immobilized idiotype and by passive haemagglutination with idiotype-coupled red cells. The sensitivity of the two methods was comparable, though some cross-reactions were only detected by RIA. Passive haemagglutination was found to be especially suitable in screening for monoclonal anti-idiotypes in hybridoma supernatants and ascites, and had advantages over RIA in detection of syngeneic anti-idiotypes. Demonstration of binding site-associated idiotopes was possible by haemagglutination inhibition. RIA and haemagglutination were used to investigate the idiotypic relationships between BALB/c antiprogesterone and anti-arsonate monoclonal antibodies which share heavy chains encoded by VHIX variable region genes.

Amino Acid Sequence↗

PubMed2006

Cyanobacterial peptides - nature's own combinatorial biosynthesis.

Cyanobacterial secondary metabolites have attracted increasing scientific interest due to bioactivity of many compounds in various test systems. Among the known structures, oligopeptides are often found with many congeners sharing conserved substructures, while being highly variable in others. A major part of known oligopeptides are of non-ribosomal origin and can be grouped into classes with conserved structural properties. Thus, the overall structural diversity of cyanobacterial oligopeptides only seemingly suggests an equally high diversity of biosynthetic pathways and respective genes. For each class of peptides, some of which have been found in all major branches of the cyanobacterial evolutionary tree, homologous synthetases and genes can be inferred. This implies that non-ribosomal peptide synthetase genes are a very ancient part of the cyanobacterial genome and presumably have evolved by recombination and duplication events to reach the present structural diversity of cyanobacterial oligopeptides. In addition, peptide synthetases would appear to be an essential part of the cyanobacterial evolution and physiology. The present review presents an overview of the biosynthesis of cyanobacterial peptides and corresponding gene clusters, the structural diversity of structural types and structural variations within peptide classes, and implications for the evolution and plasticity of biosynthetic genes and the potential function of cyanobacterial peptides.

Cyanobacteria↗

PubMed1995

The transmissible spongiform encephalopathies.

The human transmissible spongiform encephalopathies (TSEs), or prion diseases, are a group of rapidly progressive disorders characterized by a spectrum of clinical abnormalities that include cognitive impairment, ataxia, myoclonus, and visual, pyramidal, and extrapyramidal signs. They share a spongiform (vacuolar) degeneration and variable amyloid plaque formation. Examples of TSEs are kuru, an infectious disease; Creutzfeldt-Jakob disease (CJD), which may take an infectious, genetic, or sporadic form; and Gerstmann-Sträussler-Scheinker disease (GSS) and fatal familial insomnia (FFI), rare familial disorders. With the exception of FFI, all of these disorders have been experimentally transmitted to nonhuman primates and laboratory rodents. The pathogenic PrP protein accumulating in the brain of TSE patients is a protease-resistant and insoluble product of a precursor protein molecule of unknown function that is encoded by the PRNP gene on chromosome 20. Different mutations in this gene are responsible for various phenotypes of TSE in its familial form, and a polymorphism at codon 129 controls susceptibility to the infectious and perhaps sporadic forms of disease. TSEs are transmissible amyloidoses in which the host-encoded protein has the propensity to acquire a beta-sheet conformation and produce amyloid; the accumulation of amyloid eventually destroys the neurons and induces the deadly disease.

Animals↗

PubMed2003

Assessment of communication barriers in community pharmacies.

This study identified previously reported facilitators and barriers to pharmacist-client communication and then evaluated their impact on the observed communication behaviors of pharmacists. Pharmacists (n = 100) completed a seven-page questionnaire collecting information on 11 variables that had been organized according to the Policy, Regulatory and Organizational Constructs in Educational and Ecological Development (PROCEDE) model as predisposing, enabling, or reinforcing of pharmacist communication with their clients. Demographic variables also were included. "Communication quality" served as the study's dependent variable, whereas pharmacist responses served as the independent variables. Communication quality scores for each pharmacist were obtained from the analysis of 765 audiorecordings of verbal exchanges occurring between the study pharmacists and their consenting clients during 4-hour, on-site observation periods. Four of the variables examined in the study were found to share a unique relationship with communication quality (pharmacists' attitude, year of graduation, adherence expectations, and outcome expectations). Hierarchical multiple regression analysis revealed that the variables measured in the questionnaire accounted for 23% of the variance in communication quality scores. Plausible explanations for why the study was unable to capture more of the variance in its proposed relationships and future areas for research are provided.

Adult↗

PubMed2004

A hypothesized model of Korean women's responses to abuse.

Many abused married Korean women have a strong desire to leave their abusive husbands but remain in the abusive situations because of the strong influence of their sociocultural context. The article discusses Korean women's responses to spousal abuse in the context of patriarchal, cultural, and social exchange theory. Age, education, and income as component elements share common effects on the emergent variable, sociostructural power. Gender role attitudes, traditional family ideology, individualism/collectivism, marital satisfaction, and marital conflict predict psychological-relational power as a latent variable. Sociostructural, patriarchal, cultural, and social exchange theories are reconceptualized to generate the model of Korean women's responses to abuse.

Adaptation, Psychological↗

PubMed2000

Measuring cluster similarity across methods.

Cluster analysis techniques delineate groupings or categories of observations based on some shared commonality over a set of variables. If such groupings can be formed, their commonality may be investigated to define relationships that may otherwise go undetected given their complexity. However, the cluster analyses are inappropriate unless the results can be replicated. A number of clustering techniques are available, differing mostly in the technical criteria used to judge the similarity of the observations. There is added validity to the cluster structure when different methods produce similar groupings; however, in most cases, different clustering techniques will not produce identical clusters and the extent of cluster similarity becomes an important measure. In this paper the hypergeometric distribution is used to gauge cluster similarity across different methods, providing an appropriate measure of consistency. This measure is used to validate reproducibility of the clusters.

Cluster Analysis↗

PubMed1994

Thallium poisoning from maliciously contaminated food.

Four young adults presented two days after one of them had received marzipan balls packaged in a box from an expensive candy manufacturer. Two ate one candy ball, while two others shared a third. The next day, variable gastrointestinal symptoms developed. On the third day, two patients developed painful paresthesiae of the hands and feet, an early but nonspecific clinical marker of thallium poisoning. A tentative diagnosis of thallium poisoning was made based on symptoms, and treatment was initiated. The remaining candies were radiographed. Metallic densities in the candies supported the diagnosis, and atomic absorption spectroscopy was used to quantitate thallium content. Each candy contained a potentially fatal dose. Five to seven days later, hypertension and tachycardia developed in the two patients who had ingested an entire candy. All patients developed alopecia but recovered without overt neurologic or other sequelae. While the diagnosis of thallium poisoning is often delayed until alopecia develops, an early diagnosis favors an effective treatment strategy.

Adult↗

PubMed2001

Word reading and picture naming in Italian.

Results from two separate norming studies of lexical access in Italian were merged, permitting a comparison of word-reading and picture-naming latencies and the factors that predict each one for an overlapping subsample of 128 common nouns. Factor analysis of shared lexical predictors yielded four latent variables: a frequency factor, a semantic factor, a length factor, and a final factor dominated by frication on the initial phoneme. Age of acquisition (AoA) loaded highly on the first two factors, suggesting that it can be split into separate sources of variance. Regression analyses using factor scores as predictors showed that word reading and picture naming are both influenced by the frequency/AoA factor. The semantics/AoA factor influenced only picture naming, whereas the length and frication factors influenced only word reading. Generalizability of these results to other languages is discussed, including potential effects of cross-language differences in orthographic transparency.

Adult↗

PubMed1991

Putting teeth into pay-for-performance programs.

Although performance-based evaluation and salary systems are common among healthcare organizations, most facilities have not adopted rank-and-file variable compensation plans. One option, gain sharing, may draw increasing attention in health care because it is designed to reward employees based on financial performance, productivity, and quality measures--addressing some prominent concerns in the industry.

Efficiency↗

PubMed1992

Population genetics of rheumatoid arthritis.

A major component of genetic susceptibility to rheumatoid arthritis (RA) appears to be explained by inheritance of HLA-DRB1 alleles, which have a conserved sequence of amino acids in the third hyper-variable region of the molecule. This "shared epitope" is found on various DR4, DR1, and DR6 variants, as well as on DR10. The evidence for this "shared epitope" in RA is examined at the population level, including how it fits in with the available epidemiologic data and RA disease severity.

Alleles↗

PubMedDate not supplied

[Etiology, diagnosis, and treatment of pulmonary histiocytosis].

Langerhans' cell histiocytosis (LCH) encompasses a group of disorders with variable clinical features and prognosis that share in common the infiltration of involved tissues by numerous Langerhans' cell (LC), often organized in granulomas. In adults, pulmonary involvement with LCH is observed predominantly in young cigarette smokers. Lung involvement is usually an isolated or a predominant manifestation, and is characterized by LC granulomas entered on distal bronchioles. HRCT has proved to be very useful in the diagnosis of pulmonary LCT, showing in typical asess the association of nodules, cavitary nodules and cystic lesions with both thick and thin walls. The definite diagnosis of pulmonary LCT generally requires lung biopsy. The pathogenesis of pulmonary LCH is not well understood.

Adult↗

PubMed2004

Esthetic dentistry in North American dental schools.

OBJECTIVES: Esthetic dentistry is among the most dynamic areas of contemporary clinical dentistry. Teaching programs in dental schools have a strong effect on the practice of dentistry, not only for recent graduates, but also for established clinicians, especially with respect to new techniques and concepts. The purpose of the study reported here was to assess the frequency and extent of the teaching of esthetic dentistry in North American dental schools and to report how it differs among the various schools. MATERIALS AND METHODS: A 19-question survey was mailed to 64 North American dental schools. The questions inquired about the priority given to the teaching of esthetic dentistry in the school; how the subject was taught (through regular curricular courses; through a multidisciplinary approach or through elective classes); the duration of the esthetic dentistry course; the nature of the course content (theoretical or practical); the esthetic procedures taught to undergraduate students; the level of interaction among different disciplines in the teaching of esthetic dentistry; and the techniques and commercial materials used. The responses were summarized as percentages based on the number of schools that responded to each question. RESULTS: Fifty-two (81%) of the 64 dental schools completed and returned the questionnaire. Twenty-five of these schools (48%; designated group A) reported having a course exclusively for the teaching of esthetic dentistry. Twenty-seven schools (52%; designated group B) reported that esthetic dentistry was addressed in multiple courses, i.e., no specific course was available. Four schools in group B (15%) were in the process of developing a separate course for esthetic dentistry. In group A schools, esthetic dentistry was taught mainly in the operative dentistry department or division. The most frequent course duration was 4 to 6 months, but there were marked variations. Thirteen (52%) of these 25 schools had didactic and practical teaching at both the preclinical and the clinical levels. The schools in group B reported that only clinical instruction in esthetic dentistry was provided. Several concerns were addressed in the courses offered in group A schools: extrinsic and intrinsic discoloration, bleaching, diastemas, malformation and malpositioning (the latter including rotation, intrusion and labio-linguoversion), and replacement of amalgam and gold restorations. Only 7 (28%) of the group A schools reported having the support of an inhouse laboratory. The esthetic procedures taught were similar for schools in group A and group B. The use of direct posterior composite restorations, all-ceramic crowns and nonvital bleaching was more common among group B schools. Ceramic inlays, onlays and indirect posterior composite restorations were not taught by 4 (16%) of the schools in group A and 7 (26%) of the schools in group B. CONCLUSIONS: The teaching of esthetic dentistry in North American dental schools is highly variable and in many schools is shared among different disciplines. Dental schools should work together to establish the parameters for teaching this subject and should formulate the necessary standards for education and research in this new field.

Canada↗

PubMed2006

[Family socialization and values].

Occupying a fundamental place among the intra-family interaction processes are those whose objective is to socialize children in a determined system of values, norms and beliefs; in other words, parents attempt to configure a determined type of person in their children. These socialization processes are some of the most widely known functions in a family; around these, family roles are distributed and the limits of parent-child expectations and behavior patterns are set; perhaps socialization is the fundamental axle in family life. These processes are also one of the main dimensions to articulate intra-family interactions and the socio-cultural context in which the family as an institution is inscribed. For this reason, most literature regarding family interaction -if not the lion's share- deals with describing the relevant variables related to the aforementioned socialization processes.

Family↗

PubMed1996

[CD4 lymphocytopenia in patients without significant clinical pathology].

There are different causes of CD4 lymphocytopenia: neoplastic pathology, immunosuppressive therapy or other iatrogenic forms. In addition to these causes, an important role is certainly played by HIV infection which, at the AIDS stage, constantly accompanies progressive CD4 lymphocytopenia, with or without affecting the other lymphocyte components. CD4 lymphocyte deficits not correlated to HIV infection are relatively rare and are not always accompanied by progressive clinical manifestations of immunodeficiency. In the recent past an idiopathic form of CD4 lymphocytopenia (ICL) was recognised whose diagnostic criteria were defined by the Center for Disease Control (CDC) in Atlanta. Cases of ICL association with hepatitis C virus infection have been reported and anomalies partially shared by subjects suffering from common variable hypogammaglobulinemia (CVH) have been reported in some ICL carriers. The CD4 deficit in these patients is not associated with other cellular and/or humoral immunological anomalies and the clinical manifestations, essentially of scant importance, have not shown signs of progression towards severe immunodeficiency syndromes. The authors report 4 subjects with major CD4 deficit whose clinical characteristics do not match idiopathic lymphocytopenia and specific serological tests have excluded HIV infection. No known causes of CD4 lymphocytopenia have been found in these patients and they do not present major signs of clinical damage.

Adult↗

PubMed1993

Evaluation of response perseveration of rats in the radial arm maze following reinforcing and nonreinforcing drugs.

The behavioral effects of three drugs with high abuse potential (amphetamine, heroin, and nicotine) and two substances with low abuse potential (haloperidol and scopolamine) were evaluated in an eight-arm radial maze. Rats were trained to explore the maze for the food reward. Unlike most radial arm maze paradigms, a food pellet was made available every time the rat entered an arm; thus, no external restrictions were placed upon rats' exploratory pattern. Following 3 days of drug-free training, rats were injected prior to testing with one of the five drugs. Analysis of the sequences of arm entries demonstrated that the variability of the search strategy was significantly decreased by amphetamine, heroin, and nicotine. In contrast, scopolamine and haloperidol either decreased or had no effect on preservation. These data, along with previous data on ethanol and diazepam, lead to the speculation that drugs of abuse may share the common property of reducing behavioral variability.

Amphetamine↗

PubMed2000

Major gene effect on body mass index: the role of energy intake and energy expenditure.

The evidence for a major gene for body mass index (BMI) was investigated using complex segregation analysis (POINTER) in 1691 individuals belonging to 432 nuclear families residing in the Chittoor district of Andhra Pradesh, India. Since the BMI is significantly correlated with energy intake (EI) and energy expenditure of activity (EEA), the effects of each were removed from the BMI using regression analysis, and the segregation analysis was repeated on the energy-adjusted BMI. For BMI, a putative major locus could not be ruled out, and the effect (q = 0.25, accounting for 37% of the phenotypic variance) was remarkably similar to that reported in Western populations. After adjusting the BMI for EI and EEA, however, no evidence in support of a major gene could be observed, suggesting either that EI and EEA mediate the expression of the major gene effect on BMI, or that the same major gene may influence both traits. The pleiotropy hypothesis was further explored using a simple bivariate familial correlation model, in which the significance of familial cross-trait correlations (e.g., BMI in parents with BMI as predicted from the energy variables in the offspring) was examined. The cross-trait resemblance between the two measures was significant for all biological relatives, verifying the presence of shared heritable determinants (i.e., the same gene[s] and/or familial environments) accounting for 58% of the covariation. The significant cross-trait spouse correlations further suggested that at least part of the cross-trait resemblance may be due to shared environmental factors. Therefore, we conclude that there is strong evidence for shared genetic effects between BMI and the energy variables.

Adolescent↗