Morphometric analysis of muscularis proper and myenteric plexus of the normal human oesophagus. Age related changes

Background: Oesophagus is a muscular tube that transports food and liquidsby coordinated contraction of its muscular lining led by stimuli from the nerveplexus. Its muscularis proper layer consists of muscle cells, connective tissue andmyenteric plexus. The aim of our histomorphometric study was to reveal detailedcharacteristics of this layer, cell number, volume, orientation, properties of myentericplexus as well as changes related to aging.Materials and methods: Oesophagus tissue samples from 17 male cadavers weretaken from the cranial and thoracic parts. Samples were divided in 2 groups: younger(ages 21–45) and older (ages 66–78). The tissue was routinely processed,embedded and serially sectioned. Sections were stained with Masson-Goldner andCresyl-violet dyes. Digital images were analysed with the image analysis software.Statistics were performed with SPSS software.Results: The average thickness of the cranial part of the oesophageal wall andmuscularis proper was 2590 μm and 1197 μm, respectively in the younger and2453 μm and 1144 μm in the older group. Overall volume of the muscle tissuewas slightly larger in the thoracic part, and in the younger group comparedto the cranial part and the older group. The average number of the striatedmuscle cells per 100 μm in the cranial part was 771.5 and 749.7 in the youngerand the older group, respectively. Striated cells were significantly lesspresent only in the lower thoracic part of the oesophagus. In the older group,smaller striated muscle cells dominated over the larger ones. In the youngergroup, majority of the striated muscle cells were mid-sized. The thickness ofthe circular layer of muscularis proper was more affected by aging than thelongitudinal one. Ganglion cells number was lower in the older group, butplexus area was unchanged.Conclusions: Aging affects muscularis proper and myenteric plexus of the oesophagus.Major differences can be observed in the striated muscle cells size, volumeof the circular layer and number of the ganglionic cells in the myenteric plexus

Combining Independent, Weighted P-Values: Achieving Computational Stability by a Systematic Expansion with Controllable Accuracy

Given the expanding availability of scientific data and tools to analyze them, combining different assessments of the same piece of information has become increasingly important for social, biological, and even physical sciences. This task demands, to begin with, a method-independent standard, such as the -value, that can be used to assess the reliability of a piece of information. Good's formula and Fisher's method combine independent -values with respectively unequal and equal weights. Both approaches may be regarded as limiting instances of a general case of combining -values from groups; -values within each group are weighted equally, while weight varies by group. When some of the weights become nearly degenerate, as cautioned by Good, numeric instability occurs in computation of the combined -values. We deal explicitly with this difficulty by deriving a controlled expansion, in powers of differences in inverse weights, that provides both accurate statistics and stable numerics. We illustrate the utility of this systematic approach with a few examples. In addition, we also provide here an alternative derivation for the probability distribution function of the general case and show how the analytic formula obtained reduces to both Good's and Fisher's methods as special cases. A C++ program, which computes the combined -values with equal numerical stability regardless of whether weights are (nearly) degenerate or not, is available for download at our group website http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/downloads/CoinedPValues.html

Can Simply Answering Research Questions Change Behaviour? Systematic Review and Meta Analyses of Brief Alcohol Intervention Trials

BACKGROUND: Participant reports of their own behaviour are critical for the provision and evaluation of behavioural interventions. Recent developments in brief alcohol intervention trials provide an opportunity to evaluate longstanding concerns that answering questions on behaviour as part of research assessments may inadvertently influence it and produce bias. The study objective was to evaluate the size and nature of effects observed in randomized manipulations of the effects of answering questions on drinking behaviour in brief intervention trials. METHODOLOGY/PRINCIPAL FINDINGS: Multiple methods were used to identify primary studies. Between-group differences in total weekly alcohol consumption, quantity per drinking day and AUDIT scores were evaluated in random effects meta-analyses. Ten trials were included in this review, of which two did not provide findings for quantitative study, in which three outcomes were evaluated. Between-group differences were of the magnitude of 13.7 (-0.17 to 27.6) grams of alcohol per week (approximately 1.5 U.K. units or 1 standard U.S. drink) and 1 point (0.1 to 1.9) in AUDIT score. There was no difference in quantity per drinking day. CONCLUSIONS/SIGNIFICANCE: Answering questions on drinking in brief intervention trials appears to alter subsequent self-reported behaviour. This potentially generates bias by exposing non-intervention control groups to an integral component of the intervention. The effects of brief alcohol interventions may thus have been consistently under-estimated. These findings are relevant to evaluations of any interventions to alter behaviours which involve participant self-report

Progress in the management and outcome of small-cell lung cancer in a French region from 1981 to 1994

Recent analyses of series of small-cell lung cancer (SCLC) patients included in clinical trials have shown improved survival over time, but it has been impossible to determine whether this was due to selection biases, stage migration, or true therapeutic improvement. To determine if there has been a true improvement of survival over time, we reviewed the medical records of all consecutive patients diagnosed with SCLC between 1981 and 1994 in the Bas-Rhin in France. Among the 787 patients (median age 63), there was no significant period effect for sex, age, or stage. Staging work-ups became increasingly thorough (significant period effect). The mean number of investigations and of tumour sites detected correlated significantly. The chemotherapy rate increased (from 76.4% in 1981–1983 to 91.7% in 1993–1994, P = 10−5) and mediastinal irradiation decreased (to roughly 25% of patients after 1983). Median survival time increased for the overall population from 6.6 months in 1981–1983 to 11.3 months in 1993–1994 (P = 10−5), for patients with limited disease (LD) from 9.2 (P = 0.002) months to 14.0 months, and for those with extensive (ED) disease from 3.5 months to 9.6 months (P = 10−5). Significant independent prognostic factors were disease extent, clinical trial participation, period, type of chemotherapy, and mediastinal irradiation in LD. Survival time has truly improved as ‘state of the art' management of SCLC has changed. © 2001 Cancer Research Campaignhttp://www.bjcancer.co

Development and evaluation of an instrument for the critical appraisal of randomized controlled trials of natural products

<p>Abstract</p> <p>Background</p> <p>The efficacy of natural products (NPs) is being evaluated using randomized controlled trials (RCTs) with increasing frequency, yet a search of the literature did not identify a widely accepted critical appraisal instrument developed specifically for use with NPs. The purpose of this project was to develop and evaluate a critical appraisal instrument that is sufficiently rigorous to be used in evaluating RCTs of conventional medicines, and also has a section specific for use with single entity NPs, including herbs and natural sourced chemicals.</p> <p>Methods</p> <p>Three phases of the project included: 1) using experts and a Delphi process to reach consensus on a list of items essential in describing the identity of an NP; 2) compiling a list of non-NP items important for evaluating the quality of an RCT using systematic review methodology to identify published instruments and then compiling item categories that were part of a validated instrument and/or had empirical evidence to support their inclusion and 3) conducting a field test to compare the new instrument to a published instrument for usefulness in evaluating the quality of 3 RCTs of a NP and in applying results to practice.</p> <p>Results</p> <p>Two Delphi rounds resulted in a list of 15 items essential in describing NPs. Seventeen item categories fitting inclusion criteria were identified from published instruments for conventional medicines. The new assessment instrument was assembled based on content of the two lists and the addition of a Reviewer's Conclusion section. The field test of the new instrument showed good criterion validity. Participants found it useful in translating evidence from RCTs to practice.</p> <p>Conclusion</p> <p>A new instrument for the critical appraisal of RCTs of NPs was developed and tested. The instrument is distinct from other available assessment instruments for RCTs of NPs in its systematic development and validation. The instrument is ready to be used by pharmacy students, health care practitioners and academics and will continue to be refined as required.</p

Enhancement of dermal fibroblast isolation method

© 2015 University of Kragujevac, Faculty of Science. All right reserved. Cultivated fibroblasts have been widely used in a large number of in vitro studies. Although they readily proliferate under cell culture conditions, improvements in methods for their isolation are necessary. Here, we present our modified enzyme digestion method and compare its efficiency with commonly used techniques. Three foreskin samples from young, middle-aged and old donors were used. The classical explant, standard enzyme digestion method with collagenase and our improved enzyme digestion method were compared for efficiency of fibroblast isolation and the time needed to achieve 95% confluence in a 30-mm Petri dish. The explant method was the slowest to achieve fibroblast confluence, especially with the tissues from the older donors (up to 23 days). With the standard enzyme digestion method, the skin tissue was partially digested, but the fibroblasts reached confluence much faster (the younger donor cells needed approximately 7 days to reach confluence). Our modified “mixed” enzyme digestion method was the fastest (the fibroblasts from the younger donors needed up to 5 days to reach confluence). For studies requiring the primary isolation and cultivation of dermal fibroblasts, the best method to achieve this goal is the tissue digestion method with the multiple enzyme solution