Diagnostic accuracy of mediastinal width measurement on posteroanterior and anteroposterior chest radiographs in the depiction of acute nontraumatic thoracic aortic dissection

We aimed to explore the diagnostic accuracy of various mediastinal measurements in determining acute nontraumatic thoracic aortic dissection with respect to posteroanterior (PA) and anteroposterior (AP) chest radiographs, which had received little attention so far. We retrospectively reviewed 100 patients (50 PA and 50 AP chest radiographs) with confirmed acute thoracic aortic dissection and 120 patients (60 PA and 60 AP chest radiographs) with confirmed normal aorta. Those who had prior history of trauma or aortic disease were excluded. The maximal mediastinal width (MW) and maximal left mediastinal width (LMW) were measured by two independent radiologists and the mediastinal width ratio (MWR) was calculated. Statistical analysis was then performed with independent sample t test. PA projection was significantly more accurate than AP projection, achieving higher sensitivity and specificity. LMW and MW were the most powerful parameters on PA and AP chest radiographs, respectively. The optimal cutoff levels were LMW = 4.95 cm (sensitivity, 90 %; specificity, 90 %) and MW = 7.45 cm (sensitivity, 90 %; specificity, 88.3 %) for PA projection and LMW = 5.45 cm (sensitivity, 76 %; specificity, 65 %) and MW = 8.65 cm (sensitivity, 72 %; specificity, 80 %) for AP projection. MWR was found less useful and less reliable. The use of LMW alone in PA film would allow more accurate prediction of aortic dissection. PA chest radiograph has a higher diagnostic accuracy when compared with AP chest radiograph, with negative PA chest radiograph showing less probability for aortic dissection. Lower threshold for proceeding to computed tomography aortogram is recommended however, especially in the elderly and patients with widened mediastinum on AP chest radiograph

Use of endobronchial one-way valves reveals questions on etiology of spontaneous pneumothorax: report of three cases

Spontaneous pneumothoraces are believed to arise when air from the supplying airway exit via a ruptured visceral pleural bleb into the pleural cavity. Endobronchial one-way valves (EBVs) allow air exit (but not entry) from individual segmental airways. Systematic deployment of EBVs was applied to three patients with secondary spontaneous pneumothoraces and persistent airleak. In all cases, balloon-catheter occlusion of the upper lobe bronchus stopped the airleak. EBVs applied to individual upper lobe segmental airways failed to terminate the airleak, which only stopped after placements of multiple EBVs to occlude all upper lobe segments. The observation questions the traditional belief of 'one-airway-one-bleb-one-leak' in spontaneous pneumothorax

Surviving Endoplasmic Reticulum Stress Is Coupled to Altered Chondrocyte Differentiation and Function

In protein folding and secretion disorders, activation of endoplasmic reticulum (ER) stress signaling (ERSS) protects cells, alleviating stress that would otherwise trigger apoptosis. Whether the stress-surviving cells resume normal function is not known. We studied the in vivo impact of ER stress in terminally differentiating hypertrophic chondrocytes (HCs) during endochondral bone formation. In transgenic mice expressing mutant collagen X as a consequence of a 13-base pair deletion in Col10a1 (13del), misfolded α1(X) chains accumulate in HCs and elicit ERSS. Histological and gene expression analyses showed that these chondrocytes survived ER stress, but terminal differentiation is interrupted, and endochondral bone formation is delayed, producing a chondrodysplasia phenotype. This altered differentiation involves cell-cycle re-entry, the re-expression of genes characteristic of a prehypertrophic-like state, and is cell-autonomous. Concomitantly, expression of Col10a1 and 13del mRNAs are reduced, and ER stress is alleviated. ERSS, abnormal chondrocyte differentiation, and altered growth plate architecture also occur in mice expressing mutant collagen II and aggrecan. Alteration of the differentiation program in chondrocytes expressing unfolded or misfolded proteins may be part of an adaptive response that facilitates survival and recovery from the ensuing ER stress. However, the altered differentiation disrupts the highly coordinated events of endochondral ossification culminating in chondrodysplasia

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Self-Reported Gum Bleeding, Perception, Knowledge, and Behavior in Working-Age Hong Kong Chinese—A Cross-Sectional Study

Gingivitis and periodontitis are highly prevalent in Hong Kong, where the provision of oral health services is predominantly private. This cross-sectional study aimed to investigate the association between the oral symptoms of gum bleeding and self-reported behavioral factors, beliefs, and knowledge among Hong Kong Chinese. The research team commissioned the Public Opinion Programme of The University of Hong Kong to conduct a structured, population-based, computer-assisted telephone interview (CATI), which covered questions related to the demography, perception, and knowledge (including traditional Cantonese beliefs) of gum health, dental attendance, oral health behavior, and dental anxiety. A total of 1,265 individuals aged 25–60 years old were successfully contacted, and 704 (55.7%) reported prior gum bleeding experience. A total of 516 individuals (64.9% females, median 55–60 years) completed the CATI satisfactorily, and 321 (62.2%) experienced gum bleeding in the past 12 months. The factors that were significantly associated with reports of gum bleeding in the past 12 months include having periodontitis, sensitive teeth, having tertiary or higher education, flossing/interdental cleaning, not cleaning teeth well enough, lack of sleep, consuming too much ‘heaty’ food, avoiding going to the dentist when gums are bleeding, and waiting for gum bleeding to subside (p < 0.05, r2 =0.198; forward stepwise logistic regression). Within the limitations of this study, approximately half of the Hong Kong working-age adults surveyed reported experiencing gum bleeding, and 62.2% of the participants experienced it within the past 12 months. Members of Hong Kong’s working-age population who reported having higher levels of education appeared more readily aware of their gum problems. Those with bleeding gums, especially those who have discernable periodontitis, poor dental awareness/behaviors, and/or a poor lifestyle should be targeted to receive education and encouragement, which will allow them to take action and improve their own gum health

Overexpression of Cd36_03760 in Candida dubliniensis abrogates development of biofilms

Objectives: To investigate the in vitro effects of overexpression of Cd36_03760 on the development of biofilms in Candida dubliniensis Methods: C. dubliniensis strains that overexpress Cd36_03760 were constructed using a PCR-based gene targeting method. Overexpression was verified by real time quantitative PCR (RT-qPCR) using gene-specific primers upon addition of doxycycline. C. dubliniensis biofilms were prepared in polystyrene, flat bottom 96-well microtiter plates. The cell suspension (1 mL, 107cells/mL in PBS) was transferred to the wells and incubated at 37oC, 75 rpm for 90 min. After the removal of loosely adherent cells, fresh YPD (1 mL) with doxycycline (50 µg/mL) was added to the wells and incubated for 48 h for biofilm formation. The amount of protein in the extracellular matrix of the C. dubliniensis biofilms was determined using a BCA protein assay. The development of biofilms was qualitatively assessed by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Results: BCA protein assay indicated that the amount of protein in C. dubliniensis biofilms that overexpressed Cd36_03760 was reduced by ~35% (P \u3c 0.05) compared to its control. The SEM and CLSM results confirmed that overexpression of Cd36_03760 in C. dubliniensis abrogated the biofilm architecture: the biofilms were scanty, less dense, and less organised compared to its control which was relatively confluent. Conclusions: Cd36_03760 is a gene that is involved in biofilm development in C. dubliniensis. Overexpression of Cd36_03760 in C. dubliniensis disintegrates the biofilms. It sheds light on further development of novel antifungal interventions against this emerging human fungal pathogen by selectively inhibiting the activity of enzymes that are involved in biofilm development