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PubMed1992

[Infective endocarditis in heroin addicts in the province of Cádiz. A multicenter study of 150 cases].

BACKGROUND: Given the progressive increase in infectious endocarditis (IE) in intravenous drug addicts (IVDA) in the province of Cadiz the present study was designed with the aim of studying the epidemiologic and clinical characteristics of this disease in our environment. METHODS: One hundred fifty episodes of IE occurring in 133 IVDA admitted to 6 hospitals in the province of Cadiz were studied in an open, multicentric study with a protocol of gathering of common data. Well known diagnostic criteria were used for this process and a univariant technique was employed in the analysis of prognostic factors. RESULTS: Fifty-three percent of the episodes occurred in the county of Campo de Gibraltar and 32% in the area of the Bay of Cadiz. The increase of the disease has been progressive since 1984 and marked over the last two years. All the patients presented fever, abnormal chest radiography in 90% and the process was produced by Staphylococcus aureus in 88%. Echography was abnormal in 85% of the episodes and vegetation was identified in 75%. The IE was located as right in 90%, mixed in 5% and left in 5%. Surgical treatment was required in 4 patients. Mortality was of 9%. Mixed or left location (p = 0.00003) and the development of the respiratory distress syndrome of the adult (p = 0.00001) were significantly associated with greater mortality. CONCLUSIONS: Infectious endocarditis in intravenous drug addicts maintains a well defined pattern of clinical expressivity and presents identifiable factors of prognostic influence. The increase in its prevalence in the province of Cadiz is probably due to a parallel increase in the addiction to intravenous heroin in this area.

Adolescent↗
PubMed2005

Barriers to racial/ethnic minority application and competition for NIH research funding.

BACKGROUND: Despite recognition of the need to increase the pool of racial/ethnic minority investigators, racial/ethnic minority representation among National Institutes of Health (NIH)-funded investigators remains low. Racial/ethnic minority investigators bring unique perspectives and experiences that enhance the potential for understanding factors that underlie racial/ethnic variation in health and health status. Identification of barriers to successful minority competition for NIH funding and suggestions for strategies to overcome them were obtained from a concept mapping project and a meeting of minority investigators and investigators at minority-serving institutions. METHODS: Concept mapping, a mixed-methods planning approach that integrates common data collection processes with multivariate statistical analyses, was used in this exploratory project. The concept mapping approach generated a series of related "concept maps" that were used for data interpretation and meeting discussions. RESULTS: Barriers to minority investigator competition for NIH funding identified by concept mapping participants include: (1) inadequate research infrastructure, training and development; (2) barriers to development as independent researchers; (3) inadequate mentoring; (4) insensitivity, misperceptions and miscommunication about the specific needs of investigators involved in research with minority communities; (5) institutional bias in NIH policies; (6) unfair competitive environment; (7) lack of institutional support; (8) lack of support for research topics/methods relevant to research with minority communities; and (9) social, cultural and environmental barriers. DISCUSSION: Data from both the concept mapping and the meeting discussions suggest the need to use a multilevel approach to increase minority representation among funded NIH investigators. Specifically, the NIH should use strategies that overcome barriers at the home institution, within NIH and at the investigator level.

Data Collection↗
PubMed1990

A negative regulator of mitosis in Aspergillus is a putative membrane-spanning protein.

The temperature-sensitive cell cycle mutation bimE7 of Aspergillus nidulans causes cells to become blocked in mitosis at a restrictive temperature. Previous work has shown that this mitotic block is induced even when cells are arrested in the S or G2 phase. The mitotic block is also observed in cells carrying a null mutation in bimE, obtained by molecular disruption of the gene (Osmani, S.A., Engle, D.B., Doonan, J.H., and Morris, N.R. (1988) Cell 52, 241-251), indicating that a lack of bimE function is responsible for the phenotype. We have cloned the bimE gene by complementation of the mutant phenotype and have isolated and sequenced its corresponding cDNA. The gene product is encoded by a 6.5-7-kilobase mRNA. The deduced amino acid sequence suggests a protein with three transmembrane domains. The sequence contains numerous potential N-glycosylation sites and several putative cAMP-dependent phosphorylation sites. No homologous protein sequences were found in the common data bases. The bimE gene product is a novel component in the regulation of mitosis.

Amino Acid Sequence↗
PubMedDate not supplied

[Muscular involvement and fibrates. Analysis of databanks of the French System of Pharmacovigilance].

A retrospective study of the muscular adverse reactions of fibrates has been conducted from the last 5-years reports of the 30 French Regional Centers of Pharmacovigilance, centralized in the common data bank located in Lyon. Fifty four reports in which at least one fibrate stated as suspect (according to the WHO's definitions) have been reviewed. Those 54 reports represent 13% of the side-effects reported with fibrates during this same period. Fibrates seem to be involved as frequently as prescribed, so fenofibrate was the most frequently suspected and the most prescribed. The most usual terms found were "myalgia" and "elevation of CPK". This study shows evidence of the interest of the data-bank of the French System of Pharmacovigilance (which has collected 36,890 reports with all the drugs during the same period); harmonization in the choice of the terms selected for computerizing the cases would improve the exploitation of this sum of data.

Adult↗
PubMed1991

The AIDS-defining diagnosis and subsequent complications: a survival-based severity index.

To define a survival-based severity measure for AIDS, we convened a panel of AIDS experts who identified factors influencing AIDS prognosis and estimated the impact of prognostic factors on survival time. The resulting conceptual model included 19 AIDS-defining conditions and 80 subsequent AIDS-related complications. This model was tested on longitudinal disease histories of 3,937 AIDS patients in the New York State Medicaid Program diagnosed between 1983 and 1986 and followed through 1988. The initial AIDS diagnosis and complications within 3 months of AIDS onset were identified from coded diagnoses recorded on inpatient and outpatient claims. Three AIDS-defining diagnosis groups were created; survival times from least to most severe group were 25, 10, and 7 months. To determine the influence of subsequent complications on risk of death, the survival times associated with combinations of defining diagnosis groups and four severity levels of subsequent complications were determined. Median survival ranged from 43 months for the least severe defining diagnosis group without early complications to 12 months for the group with severe defining diagnoses and serious complications. The matrix of AIDS-defining diagnoses and complications was divided into four severity categories with significantly different survival curves. This severity measure uses longitudinal data commonly available to clinicians and researchers to create distinct AIDS prognostic categories.

Acquired Immunodeficiency Syndrome↗
PubMed1978

[Functional stability of the cerebral circulatory system].

Functional stability of the cerebral circulation system seems to be based on the active mechanisms and on those stemming from specifics of the biophysical structure of the system under study. This latter parameter has some relevant criteria for its quantitative estimation. Analysis of common data on various effects upon cerebral vessels shows an essential difference between the functional stability and the idea of "autoregulation of the cerebral circulation". The data obtained suggest that the essential part of the mechanism for active responses of cerebral vessels which maintains the functional stability of this portion of the vascular system, consists of a neurogenic component involving central nervous structures localized, for instance, in the medulla oblongata.

Animals↗
PubMed1984

Dysplasia and cancer in ulcerative colitis: a soluble problem?

Now that many of the problems associated with the recognition, classification and terminology of dysplasia in ulcerative colitis have been overcome, the clinical effectiveness of such a classification needs to be investigated. Because dysplasia has been defined as an unequivocally neoplastic transformation of the epithelium which is capable of giving rise to an invasive carcinoma, it follows that in waiting for the development of dysplasia in patients at risk, there will always be an associated and as yet undefined incidence of invasive carcinoma already being present. Nevertheless, it is currently inappropriate to consider proctocolectomy before such changes develop. It is emphasised that waiting for high grade dysplasia to develop may lead to an unacceptably high level of associated invasive carcinoma. Also, because dysplasia is frequently focal, the changes of detecting it on random biopsy are directly proportional to the number of biopsies taken, and if found in flat mucosa it may be difficult to confirm the presence of such dysplasia by re-biopsy. Colectomy at this stage is aimed at cancer prevention rather than early cancer detection. Conversely, targeted biopsies of endoscopically visible plaques, nodules or other abnormalities, which may already be the superficial part of invasive carcinomas, offer the best hope of early detection of carcinoma. However, a proportion of these may have metastasised already; this is much more likely to have occurred if such a lesion is found at the first colonoscopy rather than in a patient in whom several surveillance colonoscopies have been carried out. Finally, the initial stages of many colitic cancers are undetectable endoscopically or radiologically but may be biopsied accidentally. All of these factors suggest that unexpected carcinomas will occur in any long-term prospective study. Surprisingly, most will not be lethal and they can be kept to a minimum if proctocolectomy is considered once unequivocal dysplasia is demonstrated on biopsy, particularly in parts of the world where large bowel cancer is already common. Data are required which assess accurately the risk of an invasive carcinoma being present or developing when epithelium indefinite for dysplasia, low grade dysplasia or high grade dysplasia are present both with and without an endoscopic abnormality being the source of the biopsy, and when such biopsies are obtained at the first or at subsequent colonoscopies. Only then can the risks of colectomy be weighed adequately against the likelihood of carcinoma already being present.(ABSTRACT TRUNCATED AT 400 WORDS)

Biopsy↗
PubMed1994

Assessing the "modeling effect" in parasuicidal behavior: a comment on Platt (1993)

This article provides a critical evaluation of Platt's [1993] research investigating the role of modeling in the acquisition of parasuicidal behavior. The discussion focuses on general theoretical and methodological issues related to research in this area, as well as on specific concerns regarding Platt's investigation. In addition to presenting a critique of this research, a hypothetical model is presented that should lend credibility to future investigations into the theoretically posited casual relationships within the modeling paradigm. Model selection was based upon a recognition that an adequate test of the observational learning theory would need to appropriately employ correlational data commonly found in research in suicide and parasuicide. The implications for clinical practice are presented.

Attitude↗
PubMedDate not supplied

[Gastropathy caused by nonsteroidal anti-inflammatory agents].

Nonsteroidal anti-inflammatory drugs (NSAID) are widely used in current clinical practice. Several gastric lesions occur as a side effect. This review paper describes the spectrum of gastric lesions, its pathogenesis, prevalence and incidence as well as clinical data, common risk factors, treatment and the prophylaxis of NSAID gastric toxicity.

Adult↗
PubMed2004

Joint modeling of longitudinal and survival data via a common frailty.

We develop a joint model for the analysis of longitudinal and survival data in the presence of data clustering. We use a mixed effects model for the repeated measures that incorporates both subject- and cluster-level random effects, with subjects nested within clusters. A Cox frailty model is used for the survival model in order to accommodate the clustering. We then link the two responses via the common cluster-level random effects, or frailties. This model allows us to simultaneously evaluate the effect of covariates on the two types of responses, while accounting for both the relationship between the responses and data clustering. The model was motivated by a study of end-stage renal disease patients undergoing hemodialysis, where we wished to evaluate the effect of iron treatment on both the patients' hemoglobin levels and survival times, with the patients clustered by enrollment site.

Algorithms↗
PubMed2004

Imputation for incomplete high-dimensional multivariate normal data using a common factor model.

It is common in applied research to have large numbers of variables measured on a modest number of cases. Even with low rates of missingness on individual variables, such data sets can have a large number of incomplete cases. Here we present a new method for handling missing continuously scaled items in multivariate data, based on extracting common factors to reduce the number of covariance parameters to be estimated in a multivariate normal model. The technique is compared in several simulation settings to available-case analysis and to a multivariate normal model with a ridge prior. The method is also illustrated on a study with over 100 variables evaluating an emergency room intervention for adolescents who attempted suicide.

Humans↗
PubMed1997

Regression estimation using multivariate failure time data and a common baseline hazard function model.

Recent 'marginal' methods for the regression analysis of multivariate failure time data have mostly assumed Cox (1972) model hazard functions in which the members of the cluster have distinct baseline hazard functions. In some important applications, including sibling family studies in genetic epidemiology and group randomized intervention trials, a common baseline hazard assumption is more natural. Here we consider a weighted partial likelihood score equation for the estimation of regression parameters under a common baseline hazard model, and provide corresponding asymptotic distribution theory. An extensive series of simulation studies is used to examine the adequacy of the asymptotic distributional approximations, and especially the efficiency gain due to weighting, as a function of strength of dependency within cluster, and cluster size.

Animals↗
PubMed1995

Foundational issues concerning the analysis of censored data.

The common approach to analyzing censored data utilizes "competing risk" models; a class of distribution is first chosen and then the sufficient statistics are identified! An "operational Bayesian" approach (Barlow 1993) for analyzing censored data would require a somewhat different methodology. In this approach, we first determine potentially observable parameters of interest. We then determine the data summaries (sufficient statistics) for these parameters. Tsai (1994) suggests that the observed sample frequency is sufficient for predicting the population frequency. Invariant probability measures (likelihoods), conditional on the parameters of interest, are then derived based on the principle of sufficiency and the principle of insufficient reason.

Bayes Theorem↗
PubMed2006

Mass spectrometric data characteristics of commonly abused amphetamines with sequential derivatization at two active sites.

There have been reports on improved chromatographic parameters derived from the incorporation of sequential derivatization in preparing biological specimens for the analysis of opiates. This current study was designed to characterize the mass spectrometric data resulting from sequential derivatizations of commonly abused amphetamines (along with all commercially available deuterated analogs) containing two active sites, i.e., amphetamine, methylenedioxyamphetamine, phenylpropanolamine. The first derivatization groups included in this study were trifluoroacetyl, pentafluoropropionyl, and heptafluorobutyryl, while t-butyldimethylsilyl was used as the second derivatization group. Products resulting from the first step and the two-step derivatization processes were analyzed by GC-MS. Full-scan mass spectrometric data were used to select ions with potential for designating the analytes and their respective isotopically labeled analogs in quantitative analysis protocols. Selected ion monitoring data were then collected and assessed to determine the quality of these ions when one or two different derivatization groups were incorporated in the sample preparation processes. A total of 77 full-scan mass spectra and 8 ion intensity cross-contribution tables, representing various forms of derivatization and isotopic analogs of the three amphetamines, are systematically presented for reference. Evaluations of these data concluded that many, but not all, products derived from "double derivatization" (sequential derivatization with two derivatization groups), generate ions of higher quality than those derived from "single derivatization".

Journal Article↗
PubMed2004

Multiple paternity in clutches of common lizard Lacerta vivipara: data from microsatellite markers.

The common lizard (Lacerta vivipara) is a small live-bearing lacertid that reproduces once a year. In order to document the poorly known mating system of this species, we present here an assessment of multiple paternity using microsatellite markers. Paternities were established within 122 clutches belonging to two wild populations from contrasted areas and to four seminatural enclosed populations. The proportion of multiply sired clutches was found to be very high (between 50.0% and 68.2%) and similar among populations, which suggests that the mating system of this species may be insensitive to environmental and population conditions.

Animals↗
PubMed1996

Studies on the immunoglobulin-E system of the common marmoset in comparison with human data.

In the common marmoset (Callithrix jacchus jacchus) immunoglobulin E (IgE) serum levels and IgE synthesis of peripheral blood mononuclear cells (PBMC) in vitro were investigated in order to look for homologies to the human system. While IgE was not found in marmoset blood plasma with three commercial antihuman IgE-kits with monoclonal antibodies (mAbs), two other kits using polyclonal antibodies against human IgE revealed detectable IgE concentrations of up to 10 kU/liter in plasma samples of 19 out of 21 marmosets. In accord with human data, rhIL-4 showed biological functions under in vitro conditions in PBMC of the New World monkey. Proliferation, measured by 3H-thymidine incorporation, of isolated PBMC of marmosets could be induced by rhIL-4. FACScan analysis showed an enhanced expression of the low affinity IgE receptor CD23 (Fc epsilon RII) on CD20+ B lymphocytes after incubation with rhIL-4. Furthermore, PBMC from marmosets could be stimulated by IL-4 alone or in combination with dexamethasone as well as with lipopolysaccharide (E. coli) to produce IgE in culture. The results indicate that Callithrix jacchus is using an IgE system that is rather similar to that of humans, although not completely identical. Antihuman mAbs and rhIL-4 can be used to investigate IgE regulation in vitro of marmoset PBMC. These data encourage the development of a primate animal model for studying possible modifications of the IgE system under pathological conditions to find new therapeutic strategies in atopic diseases.

Animals↗