In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
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Question: Context: To systematically review methodological articles which focus on nonpublication of studies and to describe methods of detecting and/or quantifying and/or adjusting for dissemination in meta-analyses. To evaluate whether the methods have been applied to an empirical data set for which one can be reasonably confident that all studies conducted have been included.', 'We systematically searched Medline, the Cochrane Library, and Web of Science, for methodological articles that describe at least one method of detecting and/or quantifying and/or adjusting for dissemination bias in meta-analyses.', 'The literature search retrieved 2,224 records, of which we finally included 150 full-text articles. A great variety of methods to detect, quantify, or adjust for dissemination bias were described. Methods included graphical methods mainly based on funnel plot approaches, statistical methods, such as regression tests, selection models, sensitivity analyses, and a great number of more recent statistical approaches. Only few methods have been validated in empirical evaluations using unpublished studies obtained from regulators (Food and Drug Administration, European Medicines Agency).\Question: Are methods for detecting , quantifying , and adjusting for dissemination bias in meta-analysis described?

Answer: We present an overview of existing methods to detect, quantify, or adjust for dissemination bias. It remains difficult to advise which method should be used as they are all limited and their validity has rarely been assessed. Therefore, a thorough literature search remains crucial in systematic reviews, and further steps to increase the availability of all research results need to be taken.

Question: Context: Allergic asthma is characterized by inflammation and airway remodeling. Bronchial epithelium is considered a key player in coordinating airway wall remodeling. In mild asthma, the epithelium is damaged and fails to proliferate and to repair, whereas in severe asthma, the epithelium is highly proliferative and thicker. This may be due to different regulatory mechanisms. The purpose of our study was to determine the role of miRNAs in regulating proliferation of bronchial epithelial cells obtained from severe asthmatic subjects in comparison with cells obtained from mild asthmatics and healthy controls.', 'Human bronchial epithelial cells (BEC) were isolated by bronchoscopy from bronchial biopsies of healthy donors and patients with mild and severe asthma. MiRNA expression was evaluated using the TaqMan low-density arrays and qRT-PCR. Transfection studies of bronchial epithelial cells were performed to determine the target genes. Cell proliferation was evaluated by BrdU incorporation test.', 'MiR-19a was upregulated in epithelia of severe asthmatic subjects compared with cells from mild asthmatics and healthy controls. Functional studies based on luciferase reporter and Western blot assays suggest that miR-19a enhances cell proliferation of BEC in severe asthma through targeting TGF- receptor 2 mRNA. Moreover, repressed expression of miR-19a increased SMAD3 phosphorylation through TGF- receptor 2 signaling and abrogated BEC proliferation.\Question: Does microRNA-19a enhance proliferation of bronchial epithelial cells by targeting TGFR2 gene in severe asthma?

Answer: Our study uncovers a new regulatory pathway involving miR-19a that is critical to the severe phenotype of asthma and indicates that downregulating miR-19a expression could be explored as a potential new therapy to modulate epithelium repair in asthma.

Question: Context: The Cochrane Central Register of Controlled Trials, PubMed Medline and Latin American and Caribbean Health Science literature databases were searched, and searches made by hand of identified papers, to source relevant data. (BIOSIS Previews) were searched. There were no language restrictions.', 'Studies were evaluated by two reviewers independently. Only clinical trials were included that were published in the English, Spanish and Portuguese languages and were performed on humans. Articles were excluded when the examiners were not calibrated; when they did not compare manual and electronic probing techniques; when they did not measure the clinical attachment level (CAL); and when the subjects did not present destructive periodontal disease or had already received periodontal treatment.', 'The quality of the identified studies was assessed and standardised data extracted. Only two studies met all the selection criteria so no meta-analysis was performed.', 'Only two of the 37 identified articles were included in the review. The results of these two studies showed that the mean variance and the absolute mean difference between CAL measurements for the two types of probes were not statistically different.\Question: Do manual and electronic probes have similar reliability in the measurement of untreated periodontitis?

Answer:
Manual and electronic probes were of similar reliability when used to measure CAL in individuals who had untreated periodontitis and when used by a calibrated examiner, but this finding is not supported by strong evidence.