Epidermal growth factor-induced epithelio-mesenchymal transition in human breast carcinoma cells

PMC42-LA cells display an epithelial phenotype: the cells congregate into pavement epithelial sheets in which E-cadherin and beta-catenin are localized at cell-cell borders. They abundantly express cytokeratins, although 5% to 10% of the cells also express the mesenchymal marker vimentin. Stimulation of PMC42-LA cells with epidermal growth factor (EGF) leads to epithelio-mesenchymal transition-like changes including up-regulation of vimentin and down-regulation of E-cadherin. Vimentin expression is seen in virtually all cells, and this increase is abrogated by treatment of cells with an EGF receptor antagonist. The expression of the mesenchyme-associated extracellular matrix molecules fibronectin and chondroitin sulfate proteoglycan also increase in the presence of EGF. PMC42-LA cells adhere rapidly to collagen I, collagen IV, and laminin-1 substrates and markedly more slowly to fibronectin and vitronectin. EGF increases the speed of cell adhesion to most of these extracellular matrix molecules without altering the order of adhesive preference. EGF also caused a time-dependent increase in the motility of PMC42-LA cells, commensurate with the degree of vimentin staining. The increase in motility was at least partly chemokinetic, because it was evident both with and without chemoattractive stimuli. Although E-cadherin staining at cell-cell junctions disappeared in response to EGF, beta-catenin persisted at the cell periphery. Further analysis revealed that N-cadherin was present at the cell-cell junctions of untreated cells and that expression was increased after EGF treatment. N- and E-cadherin are not usually coexpressed in human carcinoma cell lines but can be coexpressed in embryonic tissues, and this may signify an epithelial cell population prone to epithelio-mesenchymal-like responses.     

Therapist use of silence in therapy: a survey

Eighty-one therapists responded to a mailed survey about their use of silence during a specific event in therapy and about their general attitudes about using silence in therapy. For the specific event, therapists used silence primarily to facilitate reflection, encourage responsibility, facilitate expression of feelings, not interrupt session flow, and convey empathy. During silence, therapists observed the client, thought about the therapy, and conveyed interest. In general, therapists indicated that they would use silence with clients who were actively problem solving, but they would not use silence with very disturbed clients. Therapists learned about using silence mostly through clinical experience.     

Leukotriene D4-induced, epithelial cell-derived transforming growth factor β1 in human bronchial smooth muscle cell proliferation

Background Cysteinyl‐leukotrienes (cys‐LTs) orchestrate many pathognomonic features of asthma in animal models of allergic airway inflammation, including bronchial smooth muscle cell (BSMC) hyperplasia. However, because cys‐LTs alone do not induce mitogenesis in monocultures of human BSMC, the effect observed in vivo seemingly involves indirect mechanisms, which are still undefined. Objective This study aims to investigate the regulatory role of leukotriene (LT)D₄ on TGF‐β1 expression in airway epithelial cells and the consequence of this interplay on BSMC proliferation. Methods HEK293 cells stably transfected with cys‐LT receptor 1 (CysLT1) (293LT1) were stimulated with LTD₄ and TGF‐β1 mRNA and protein expression was measured using Northern blot and ELISA, respectively. Conditioned medium (CM) harvested from LTD₄‐treated cells was then assayed for its proliferative effect on primary human BSMC. TGF‐β1 mRNA expression was also determined in tumoural type II pneumocytes A549 and in normal human bronchial epithelial cells (NHBE) following LTD₄ stimulation. Results The results demonstrated that LTD₄‐induced TGF‐β1 mRNA production in a time‐ and concentration‐dependent manner in 293LT1. TGF‐β1 secretion was also up‐regulated and CM from LTD₄‐treated 293LT1 was shown to increase BSMC proliferation in a TGF‐β1‐dependent manner. The increased expression of TGF‐β1 mRNA by LTD₄ also occured in A549 and NHBE cells via a CysLT1‐dependent mechanism. Conclusion In conclusion, elevated expression of cys‐LTs in asthmatic airways might contribute to BSMC hyperplasia and concomitant clinical features of asthma such as airway hyperresponsiveness via a paracrine loop involving TGF‐β1 production by airway epithelial cells.     

Allometric scaling of isometric biceps strength in adult females and the effect of body mass index

The purposes of this study were to (1) derive and test allometric scaling models of biceps isometric strength using body mass (BM) and muscle cross-sectional area (CSA) as the scaling variables, (2) assess the influence of body mass index (BMI) by separating the cohort by BMI (normal <25 kg/m² vs. overweight/obese ≥25 kg/m²) and repeating step 1, and (3) assess the effect of BMI on isometric strength allometrically adjusted for differences in CSA by comparing scaled strength between normal weight versus overweight/obese women. The participants were 183 women (18–39 years old) who reported no strength training in the prior year. Isometric strength and CSA of the biceps were assessed on the non-dominant arm. The CSA allometric model met all statistical criteria and produced a scaling exponent of 0.44. The BM model did not meet these criteria until the entire cohort was separated by BMI. The scaling exponents for normal weight and overweight/obese women were 1.48 and 0.35, respectively. These data suggest that BMI exerted an influence on the relationship between BM and allometrically scaled isometric strength and may be explained by previous studies demonstrating greater contribution of fat mass (FM) versus fat-free mass (FFM) to BMI in overweight/obese women. As such, allometric scaling models of isometric strength, especially in populations that are heterogeneous with regard to body composition, must be carefully tested and examined across the range of BMI. Isometric strength relative to CSA was not significantly different between groups. However, allometrically scaled strength, using CSA as the criterion variable, was significantly greater in overweight/obese women compared to those of normal weight. These data suggest that isometric strength in women is not completely determined by CSA and other factors such as intramuscular fat and muscle fiber type may be confounding or contributing factors.     

Short sleep duration in middle childhood: risk factors and consequences

STUDY OBJECTIVES: To measure sleep duration in 7-year-old children; identify the determinants of sleep duration; and assess the association between short sleep duration and obesity, cognitive functioning, and behaviour. DESIGN: Longitudinal study with disproportionate sampling of the participants. SETTING: Community. PARTICIPANTS: 591 seven-year-old children, of whom 519 had complete sleep data. INTERVENTIONS: Not applicable. MEASUREMENTS: Sleep duration was assessed by actigraphy. Other measurements included height, weight, BMI, percentage body fat as assessed by bioimpedance assay, intelligence (WISC-III) and behaviour (Strengths & Difficulties questionnaire, parent and teachers Conners Rating Scales). RESULTS: Mean time in bed according to parental report was 10.9 hours (SD 0.8). Mean sleep duration by actigraphy was 10.1 (SD 0.8) hours. In multivariable analysis, sleep duration was longer on weekdays vs. weekend nights (31.5 min, P = 0.002), in winter (40.5 min), autumn (31.1 min), and spring (14.8 min) compared with summer (P <0.0001), and in those with younger siblings (11.7 min, P = 0.03). Sleep duration was shorter when bedtime was after 21:00 (-41.1 min, P <0.0001). In multivariable analysis, sleep duration <9 hours was associated with being overweight/ obese (BMI: OR = 3.32; 95% CI = 1.40, 7.87) with an increase of 3.34% body fat (P = 0.03), and this was not explained by physical activity or television watching. Short sleep duration was also associated with higher emotional lability scores (Conners Rating Scale Parent Form; P = 0.03). IQ (WISC-III) and attention deficit / hyperactivity disorder scores (both parent and teachers Conners Rating Scales) did not differ with sleep duration. CONCLUSIONS: Sleep duration in 7-year-old children varies considerably among individuals. The duration is affected by weekday, season, and having younger siblings. Importantly, short sleep duration was shown to be an independent risk factor for obesity/overweight.     

Performance of hydroxyapatite bone repair scaffolds created via three-dimensional fabrication techniques

The current study analyzes the in vivo performance of porous sintered hydroxyapatite (HA) bone repair scaffolds fabricated using the TheriForm solid freeform fabrication process. Porous HA scaffolds with engineered macroscopic channels had a significantly higher percentage of new bone area compared with porous HA scaffolds without channels in a rabbit calvarial defect model at an 8-week time point. An unexpected finding was the unusually large amount of new bone within the base material structure, which contained pores less than 20 microm in size. Compared with composite scaffolds of 80% polylactic-co-glycolic acid and 20% beta-tricalcium phosphate with the same macroscopic architecture as evaluated in a previous study, the porous HA scaffolds with channels had a significantly higher percentage of new bone area. Therefore, the current study indicates that scaffold geometry, as determined by the fabrication process, can enhance the ability of a ceramic material to accelerate healing of calvarial defects.     

Phylogenetic analysis of Portuguese bovine viral diarrhoea virus

Bovine viral diarrhoea virus (BVDV) infections are an important cause of morbidity and mortality worldwide in dairy and beef cattle. To date, little is know about BVDV genotypes circulating in Portugal. For this purpose, a fragment within the 5'-untranslated region (5'-UTR) from 34 Portuguese field strains of BVDV was amplified by RT-PCR, cloned and sequenced. A maximum-likelihood phylogenetic analysis revealed that most of viruses, originated from cattle from different regions of the country, belong to BVDV type 1 (BVDV-1), genotypes 1b (n = 19), 1a (n = 6), 1d (n = 3) and 1e (n = 3); whereas three viruses clustered in BVDV type 2 (BVDV-2). The results from this study demonstrate that BVDV-lb is the most prevalent genotype and also shows the presence of BVDV-2 in Portugal.