We have isolated and characterized a new LTR-retrotransposon in the genome of the Mediterranean fruit fly (Medfly), Ceratitis capitata. This retrotransposon, which we named yoyo, appears to be a member of the gypsy/Ty3 class of elements. The yoyo element was originally discovered on the Y chromosome of the Medfly. Although the Y chromosome copy appears to be truncated, at least two other apparently complete copies of yoyo from other genomic locations have been isolated and characterized. The complete element is approximately 7.7 kb in size. In addition to fairly typical GAG and POL coding regions, the yoyo element contains a potential ENV gene. The presence of an ENV gene is a key feature distinguishing potential retroviral-like elements, such as gypsy (and possibly yoyo), from many other invertebrate retrotransposons previously described. In addition to the structural features of yoyo, evidence is provided to show that yoyo is capable of movement in the genome, including RFLPs showing variability in genomic localization of copies of yoyo between strains, and differences among individuals in the presence of yoyo at a specific site in the genome.

Amino Acid Sequence↗

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Stimulatory effect of splicing factors on transcriptional elongation.

Transcription and pre-mRNA splicing are tightly coupled gene expression events in eukaryotic cells. An interaction between the carboxy-terminal domain of the largest subunit of RNA polymerase (Pol) II and components of the splicing machinery is postulated to mediate this coupling. Here, we show that splicing factors function directly to promote transcriptional elongation, demonstrating that transcription is more intimately coupled to splicing than previously thought. The spliceosomal U small nuclear ribonucleoproteins (snRNPs) interact with human transcription elongation factor TAT-SF1 (refs 6,7,8,9) and strongly stimulate polymerase elongation when directed to an intron-free human immunodeficiency virus-1 (HIV-1) template. This effect is likely to be mediated through the binding of TAT-SF1 to elongation factor P-TEFb, a proposed component of the transcription elongation complex. Inclusion of splicing signals in the nascent transcript further stimulates transcription, supporting the notion that the recruitment of U snRNPs near the elongating polymerase is important for transcription. Because the TAT-SF1-U snRNP complex also stimulates splicing in vitro, it may serve as a dual-function factor to couple transcription and splicing and to facilitate their reciprocal activation.

Cyclin T↗

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Workplace access, negative proscriptions, job strain, and substance use in registered nurses.

BACKGROUND: Both occupational conditions and individual factors have been shown as contributors to the likelihood of substance use among health professionals. OBJECTIVES: To assess the use of Winick's (1974) model for explaining nurses' substance use, which asserts that groups with access to substances, freedom from negative proscriptions, and role strain have an increased likelihood of drug dependence. METHODS: Data were analyzed from the 3,600 working nurses participating in the Nurses Worklife and Health Study, a nationally representative survey of registered nurses in the United States. A structural equation model was tested fitting workplace access to substances (availability, frequency of administration, and knowledge), freedom from negative proscriptions (internal: religiosity; external: social network), and role strain (job demands and depressive symptoms) to the frequency of past year alcohol, marijuana/cocaine, and prescription-type drug use. RESULTS: Nurses were more likely to use substances when workplace access to substances increased (p < 0.001), with social networks containing more drug users, and when religiosity decreased (p < 0.001). Role strain (measured through job demands and depressive symptoms) also was related to substance use. Depressive symptoms were related directly and negatively to substance use (p < 0.01), whereas job demands were related indirectly to substance use through depressive symptoms. CONCLUSIONS: Winick's model has use in explaining nurses' substance use. Research and preventive initiatives should consider the multidimensional aspects of substance use in nurses.

Adult↗

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Rhodes Index of Nausea and Vomiting--Form 2 in pregnant women. A confirmatory factor analysis.

BACKGROUND: Despite widespread application of Rhodes Index of Nausea and Vomiting-Form 2 (INV2) in practice and research, empirical analyses have not been consistently performed to verify the a priori factors that guided the subclass construction of the symptoms. OBJECTIVES: To examine the dimensional structure of Rhodes INV in a sample of pregnant women. METHOD: Data were collected from 152 pregnant women who were experiencing some degree of nausea and vomiting during early pregnancy and analyzed using structural equation modeling techniques. Five competing measurement structures were tested and compared. The structure (model) that provided the closest fit to the data was selected and relationships (factor loadings) between the constructs and indicators were established. RESULTS: The model fitting the data the closest was a three-factor structure measuring nausea, vomiting, and retching as three separate, but correlated dimensions. The factor loadings were high (0.73-0.96) and significant (p < .001). The model treating nausea and vomiting as a one-factor concept as well as the model including two factors named symptom occurrence and symptom distress did not fit the data. CONCLUSION: Rhodes INV2 is a valid measurement tool if subscales are formed to reflect the multidimensional structure of nausea and vomiting in pregnancy.

Adolescent↗

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Brazilian adolescents' prosocial moral judgment and behavior: relations to sympathy, perspective taking, gender-role orientation, and demographic characteristics.

The goal of this study was to examine demographic and individual difference variables that predict level of prosocial moral judgment and self-reported prosocial behavior and to test mediating or moderating relations among predictors. The relations of prosocial moral reasoning and self-reported prosocial behavior to perspective taking, sympathy, age, sociometric status, and gender-role orientation were examined with a sample of 149 Brazilian adolescents who completed a series of questionnaire measures. Prosocial moral judgment was expected to be predicted by both sympathy and perspective taking, whereas sympathy or prosocial moral judgment was expected to mediate the relations of femininity and perspective taking to prosocial behavior. Self-reported perspective taking and sympathy interacted when predicting prosocial moral judgment; adolescents who were high in either sympathy or perspective taking (or both) scored high in prosocial moral reasoning. A feminine orientation predicted sympathy and perspective taking, perspective taking predicted prosocial moral reasoning and sympathy, and sympathy had both direct and indirect paths (through moral judgment) to prosocial behavior. The findings generally were consistent with the contention that both the tendency to take others' perspectives and to sympathize are related to level of prosocial moral reasoning, which in turn motivates prosocial behavior. Moreover, patterns of correlations among variables were similar to those found in the United States.

Adolescent↗

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A quality measurement framework for managed care organizations.

This article presents a framework for a quality measurement system and its corresponding principles for quality improvement within a managed care environment. The quality measurement system comprises four modes: quality assessment, comparison, improvement, and system evaluation. If these modes are to be effective, the measurement system must incorporate the following five principles: (a) maintain and continually improve the data systems, (b) develop and utilize sound methodology and valid indicators, (c) build a competent measurement team, (d) develop effective strategies for implementation, and (e) protect member confidentiality. This model is helpful in the ongoing development and testing of new measurement systems.

Boston↗

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A novel snake venom disintegrin that inhibits human ovarian cancer dissemination and angiogenesis in an orthotopic nude mouse model.

OVCAR-5 is a human epithelial carcinoma cell line of the ovary, established from the ascitic fluid of a patient with progressive ovarian adenocarcinoma without prior cytotoxic treatment. The unique growth pattern of ovarian carcinoma makes it an ideal model for examining the anticancer activity of contortrostatin (CN), a homodimeric disintegrin from southern copperhead venom. FACS analysis revealed that OVCAR-5 is integrin alphavbeta3 negative, but alphavbeta5 positive. CN effectively blocks the adhesion of OVCAR-5 cells to several extracellular matrix proteins and inhibits tumor cell invasion through an artificial basement membrane. In a xenograft nude mouse model with intraperitoneal introduction of OVCAR-5 cells, intraperitoneal injection of CN was used for therapy. Tumor dissemination in CN-treated versus control groups was studied by gross examination, and antiangiogenic potential was examined by factor VIII immunohistochemistry and image analysis. CN not only significantly inhibited ovarian cancer dissemination in the nude mouse model, but it also dramatically prevented the recruitment of blood vessels to tumors at secondary sites.

Agkistrodon↗

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Reliability of urinary 6-sulfatoxymelatonin as a biomarker in breast cancer.

The objective of this study is to evaluate the effect of cryopreservation at different storage temperatures on urinary 6-sulfatoxymelatonin (aMT6s) concentration. Overnight urine from 28 postmenopausal women participating in the ORDET cohort study was filtered and separated into 6 mL aliquots. Urine samples were stored at -80 degrees C and at -30 degrees C for an average of 14 years. Urinary aMT6s concentration was assessed using a competitive immunoassay. Mean aMT6s values of samples stored at -30 degrees C were systematically lower than those of samples stored at -80 degrees C (10.7 ng/mL versus 15.8 ng/mL, p<0.001). Bland Altman plots showed disagreement between determinations at different storage temperatures at the highest levels of the metabolite concentration. The degree of agreement evaluated in terms of intraclass correlation coefficient was 0.68 (95% CI 0.41-0.84, p<0.0001). Pearson's correlation coefficient between aMT6s values of the two differently stored samples was 0.93 (p<0.001), while the Kendal tau coefficient for rank distribution was 0.73 (p<0.001). Our data suggest that storage temperatures might affect degradation of aMT6s during storage. However, individual characterization by melatonin levels does not seem to be affected by cryopreservation conditions.

Adult↗

PubMedDate not supplied

Confocal scanning laser tomography of the cornea with the total corneal analyzer.

Explore the source record for details and available documents.

Cornea↗

PubMedDate not supplied

Apoptosis and cell proliferation in esophageal precancerous and cancerous lesions: study of a high-risk population in northern China.

Changes in cell proliferation and cell death might be key factors in regulating the rate of neoplasm progression and tumor growth. The extent of apoptosis and its possible relationship with cell proliferation at different stages of esophageal carcinogenesis, however, have not been characterized. In this study, 241 esophageal biopsy samples from symptom-free subjects and 38 surgically resected esophageal carcinoma tissues from a high-risk population for esophageal cancer in Henan, China, were used to analyze the changes of apoptosis and its relationship with cell proliferation as determined by proliferating cell nuclear antigen (PCNA). The apoptotic cells, identified morphologically, were located in the same proliferative compartment of hyperproliferative cell population in the esophageal epithelium. The apoptotic indices (total number of apoptotic cells and apoptotic bodies per mm2 of the tissue section) were low in the normal epithelia, and increased significantly as the lesions progressed from basal cell hyperplasia (BCH) to dysplasia (DYS) and to squamous cell carcinoma (SCC). The extent of apoptosis correlated well with the cell proliferation indices. The present findings indicate that apoptosis occurs in the early stage of esophageal carcinogenesis, and as the lesions progress, both the apoptotic index and PCNA labelled index increase, suggesting that hyperproliferative cells might be more susceptible to apoptosis.

Adult↗

PubMedDate not supplied

Morphologic changes in efferent ductules and epididymis in estrogen receptor-alpha knockout mice.

Estrogen has been shown to have an important role in fluid reabsorption in efferent ductules of the testis. Our previous study of the estrogen receptor-alpha knockout mouse (ERKO) showed that the efferent ductules and rete testis were primary targets of estrogen receptor function. In the present study, a more comprehensive evaluation of the ERKO male reproductive tract was performed to determine the severity of effects in efferent ductules as well as the epididymis. The following observations were found in ERKO males: 1) blind-ending efferent ductules were more prevalent in ERKO than in wild type (WT) tissues; 2) glycogen-containing cells were observed at the rete testis-efferent ductule junction; 3) the tubular diameters of the efferent ductules and initial segment epididymides were dilated; 4) efferent ductules were dilated between 130 to 300% over wild type ductules; 5) efferent ductule epithelial height was reduced nearly 50%; 6) microvilli of nonciliated cells of efferent ductules were 64% shorter in length; 7) cilia were reduced in number; 8) initial segment epithelium was displaced into regions adjacent to the rete testis and in short segments of the common region of efferent ductule; 9) apical, narrow, and clear cells of the epididymis also were abnormal in some regions; 10) in the corpus and cauda regions, sperm granulomas were noted in one third of the ERKO males. In conclusion, the entire reproductive tract is affected in ERKO males. The cells showing the greatest effects were estrogen receptor-positive cells. It appears that in the ERKO mouse there are developmental anomalies that must be considered separately from adult dysfunctional changes in the male reproductive tract.

Animals↗