Mouse MOV10L1 associates with Piwi proteins and is an essential component of the Piwi-interacting RNA (piRNA) pathway

Piwi-interacting RNAs (piRNAs) are essential for silencing of transposable elements in the germline, but their biogenesis is poorly understood. Here we demonstrate that MOV10L1, a germ cell–specific putative RNA helicase, is associated with Piwi proteins. Genetic disruption of the MOV10L1 RNA helicase domain in mice renders both MILI and MIWI2 devoid of piRNAs. Absence of a functional piRNA pathway in Mov10l1 mutant testes causes loss of DNA methylation and subsequent derepression of retrotransposons in germ cells. The Mov10l1 mutant males are sterile owing to complete meiotic arrest. This mouse mutant expresses Piwi proteins but lacks piRNAs, suggesting that MOV10L1 is required for piRNA biogenesis and/or loading to Piwi proteins.     

Decreased expression of phospholipase C-beta 2 isozyme in human platelets with impaired function

Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate, mobilization of intracellular Ca2+, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation (see accompanying report). A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, 7 out of 10 known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC- gamma 2 > PLC-beta 2 > PLC-beta 3 > PLC-beta 1 > PLC-gamma 1 > PLC- delta 1 > PLC-beta 4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-beta 2, whereas PLC-beta 4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-beta 2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.     

Differential mononuclear cell activity and endothelial inflammation in coronary artery disease and cardiac syndrome X

BACKGROUND: Circulating mononuclear cells could be activated with endothelial inflammation in patients with coronary artery disease (CAD). In some patients with normal coronary angiograms, myocardial ischemia could also present with coronary microvascular dysfunction (cardiac syndrome X). This study was undertaken to investigate whether mononuclear cell activation and endothelial inflammation can present in syndrome X patients. METHODS: We evaluated the biochemical parameters, circulating soluble adhesion molecules, circulating superoxide free radicals, and mononuclear cell activity in 32 patients with syndrome X, 34 with angiographically documented CAD, and 17 age- and gender-matched healthy control subjects. RESULTS: Compared to that in control subjects, plasma high-density lipoprotein was reduced (P<0.001) and insulin to glucose ratio increased (P=0.02) in CAD patients. Circulating level of soluble intracellular adhesion molecule-1 was significantly higher in both syndrome X and CAD patients than in control subjects (P<0.01), whereas the levels of soluble vascular cell adhesion molecule (P=0.02) and von Willebrand factor (P=0.01) were increased in CAD patients only. The peak (P<0.001) and total counts of superoxide free radicals in whole blood (P<0.001) was significantly higher in syndrome X patients than in the other two groups. However, phorbol-12-myristate-13-acetate-induced superoxide free radical generation of mononuclear cells was increased in CAD (10.5+/-4.6%, P=0.01) but not in syndrome X patients (8.7+/-2.0%) as compared with control subjects (7.7+/-0.5%). CONCLUSIONS: The results indicated that the activity of mononuclear cells was increased with significant endothelial inflammation and injury in CAD patients. In syndrome X patients, though circulating superoxide free radicals were increased, there was minimal endothelial inflammation without mononuclear cell activation. The relatively preserved lipid and metabolic profiles might contribute to less vascular inflammation in syndrome X patients.     

Biological activity of autoantibodies associated with Graves' dermopathy

To test the hypothesis that Graves' dermopathy is due to cross-reactivity of thyroid autoantibody(ies) with a cellular target in pretibial skin, we tested the serum and serum immunoglobulin fraction of 20 such patients for their effects on the metabolic activities of cultured thyrocytes (rat FRTL cells), human pretibial skin fibroblasts, and human fibroblasts of other origins. The incorporation of 3H-labeled thymidine, amino acids, and glucosamine into DNA, protein, and glycosaminoglycans, respectively, was measured. TSH and the serum of each of the 20 patients with Graves' dermopathy markedly stimulated the synthesis of DNA, protein, and glycosaminoglycans by FRTL cells, but not by fibroblasts, whereas assays of serum from 38 of 40 patients with Graves' disease without dermopathy did not stimulate these processes in FRTL cells more than normal serum. Stimulatory activity was associated with immunoglobulins. Serum dermopathy-associated antibodies disappeared with the disappearance of the skin lesions. These results suggest that the serum of patients with dermopathy contains antibodies that recognize a component of the TSH receptor different from that recognized by serum of Graves' patients without dermopathy, the former acting in some manner to induce lesions in pretibial skin. The skin target remains unidentified.     

Use of clinical findings in the diagnosis of urinary tract infection in women

To develop a decision rule for predicting urinary culture results in patients suspected of having urinary tract infection, we used discriminant analysis to identify the optimum combination of clinical findings. Thirty variables identified in a pilot study were recorded from 248 patients in a second study. Five findings were independent predictors of positive urinary culture: history of urinary tract infection, back pain, microscopic pyuria, hematuria, and bacteriuria. An additive decision rule that assigned one point for each of the five variables was tested in a third group of 258 patients. These scores stratified patients into subsets with increasing likelihood of positive culture. Higher scores identified patients who can confidently be treated without documentation of bacteriuria. If the rule applies successfully to other populations, cost savings could result from identification of patients who do not require quantitative urinary culture to demonstrate significant bacteriuria.     

Levels of Circulating Microparticles in Lung Cancer Patients and Possible Prognostic Value

Background. Endothelial-derived microparticles (EDMPs) and platelet-derived microparticles (PDMPs) have been reported to be increasing in various diseases including malignant diseases. Here, we investigated whether these MPs may be useful biomarkers for predicting lung cancer (LC) disease status, cell type, or metastasis. Methods and Results. One hundred and thirty LC patients were prospectively enrolled into the study between April 2011 and February 2012. Flow cytometric analysis demonstrated that the circulating levels of platelet-derived activated MPs (PDAc-MPs), platelet-derived apoptotic MPs (PDAp-MPs), endothelial-derived activated MPs (EDAc-MPs), and endothelial-derived apoptotic MPs (EDAp-MPs) were significantly higher in LC patients than in 30 age- and gender-matched normal control subjects (all P < 0.05). Additionally, circulating level of PDAc-MPs was significantly lower (P = 0.031), whereas the circulating levels of the other three biomarkers did not differ (all P > 0.1) in early stage versus late stage LC patients. Furthermore, the circulating levels of the four types of MPs did not differ among patients with different disease statuses (i.e., disease controlled, disease progression, and disease without treatment, i.e., fresh case) (all P > 0.2) or between patients with or without LC metastasis (all P > 0.5). Moreover, only the circulating level of EDAp-MPs was significantly associated with the different cell types (i.e., squamous cell carcinoma, adenocarcinoma, and small cell carcinoma) of LC (P = 0.045). Conclusion. Circulating MP levels are significantly increased in LC patients as compared with normal subjects. Among the MPs, only an increased level of EDAp-MPs was significantly associated with different LC cell types.     

Social and Self-Reflective Use of a Web-Based Personally Controlled Health Management System

Background

Personally controlled health management systems (PCHMSs) contain a bundle of features to help patients and consumers manage their health. However, it is unclear how consumers actually use a PCHMS in their everyday settings.

Objective

To conduct an empirical analysis of how consumers used the social (forum and poll) and self-reflective (diary and personal health record [PHR]) features of a Web-based PCHMS designed to support their physical and emotional well-being.

Methods

A single-group pre/post-test online prospective study was conducted to measure use of a Web-based PCHMS for physical and emotional well-being needs during a university academic semester. The PCHMS integrated an untethered PHR with social forums, polls, a diary, and online messaging links with a health service provider. Well-being journeys additionally provided information to encourage engagement with clinicians and health services. A total of 1985 students and staff aged 18 and above with access to the Internet were recruited online, of which 709 were eligible for analysis. Participants’ self-reported well-being, health status, health service utilization, and help-seeking behaviors were compared using chi-square, McNemar’s test, and Student’s t test. Social networks were constructed to examine the online forum communication patterns among consumers and clinicians.

Results

The two PCHMS features that were used most frequently and considered most useful and engaging were the social features (ie, the poll and forum). More than 30% (213/709) of participants who sought well-being assistance during the study indicated that other people had influenced their decision to seek help (54.4%, 386/709 sought assistance for physical well-being; 31.7%, 225/709 for emotional well-being). Although the prevalence of using a self-reflective feature (diary or PHR) was not as high (diary: 8.6%, 61/709; PHR: 15.0%, 106/709), the proportion of participants who visited a health care professional during the study was more than 20% greater in the group that did use a self-reflective feature (diary: P=.03; PHR: P<.001).

Conclusions

There was variation in the degree to which consumers used social and self-reflective PCHMS features but both were significantly associated with increased help-seeking behaviors and health service utilization. A PCHMS should combine both self-reflective as well as socially driven components to most effectively influence consumers’ help-seeking behaviors.