Patterns of musculoskeletal disorders in health care providers and their association with ergonomic risks

Objectives. Musculoskeletal disorders (MSDs) have a high prevalence among allied health care providers because of the demanding nature of their work and lack of practicing proper ergonomics. The aim of this study focused on patterns of work-related musculoskeletal disorders (WMSDs) affecting different health care providers working in a different unit of a tertiary care hospital. Methods. This cross-sectional study collected data from 2000 allied health care providers working at various departments of Civil Hospital and Dow University Hospital of Karachi (DUHS), via self-administered questionnaire, based on Occupational Safety and Health Administration (OSHA) guidelines. Results. Our findings revealed that 92.9% of individuals had MSDs as a result of poor ergonomics, with 93% reporting that the disease interferes with their normal job routine. Conclusions. Medical technologists are the most affected group among allied health care workers. Lack of knowledge and improper ergonomic culture results in such a high prevalence rate in allied health care workers in Pakistan.

Generalized fractional Wentzel–Kramers–Brillouin approximation for electron tunnelling across rough metal interface

The conductive rough surfaces act as an integral part of several electron devices and systems. Electron tunnelling through the potential barrier imposed by the rough metal-vacuum interface is an important mechanism of charge transport in vacuum electron devices. Here, we analytically derive a generalized current–voltage relationship with a fractional image potential barrier that considers the reduced space-dimensionality encountered by the tunnelling electrons at a rough interface, in an effective manner. The traditional Schottky–Nordhiem equation based on the Schottky image potential barrier is shown to be a limiting case of our model for a perfectly flat surface. The fractional-dimension parameter used in this model accounts for the barrier reduction due to the geometrical roughness and it can be determined by fitting our model to a given current–voltage measurement. It is shown that the application of this model could reduce the error between measured current–voltage response and theoretical estimates based on the conventional model. This work provides an analytical framework for efficient design and engineering of quantum tunnelling in practical electron devices.

Diabetic keratopathy: Insights and challenges

Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially sight-threatening condition caused mostly by epithelial disturbances that are of clinical and research attention because of their severity. Diabetic keratopathy exhibits several clinical manifestations, including persistent corneal epithelial erosion, superficial punctate keratopathy, delayed epithelial regeneration, and decreased corneal sensitivity, that may lead to compromised visual acuity or permanent vision loss. The limited amount of clinical studies makes it difficult to fully understand the pathobiology of diabetic keratopathy. Effective therapeutic approaches are elusive. We summarize the clinical manifestations of diabetic keratopathy and discuss available treatments and up-to-date research studies in an attempt to provide a thorough overview of the disorder.

Metagenomics revealed a quorum quenching lactonase QlcA from yet unculturable soil bacteria

Quorum sensing (QS) is a signal mediated cell-cell communication system that couples bacterial cell density to a synchronized gene expression (Fuqua et al., 1994). Mostly, in Gram negative bacteria QS signals are N-acylhomoserine lactones (NAHLs) that coordinate important functions such as virulence and pathogenicity. QS signals or the elements involved in their production or perception could be targeted to disrupt QS, a phenomenon called Quorum quenching (QQ). QQ properties (chemicals and enzymes) are naturally found in various Living organisms, like bacteria (Rhodococcus and Commamonas), plants (carrot, soybean, pea seedling, chilli, garlic etc), and animals (human sera, pork kidney tissues). Consequently, various bacterial genes encoding for NAHL degrading enzymes, like NAHL lactonases (AiiA in Bacillus, AiiB and AttM in Agrobacterium tumefaciens) and acylase/-amidohydrolase (AiiD in Ralstonia) were identified (Givskov et al., 2006). In Pectobacterium carotovorum (causal agent of soft rot diseases) production of various virulence factors and cell wall maceration enzymes is QS dependant, and relies upon successful production, stability, emission and perception of NAHLs (C-8, oxo-C8 and C-10). Disruption of QS signalling by NAHL degrading bacteria, modified bacteria or plants expressing NAHL lactonases resulted in the reduced virulence of the pathogen (Faure et al., 2007). Until recently, investigations on QQ enzymes were carried out mostly on cultivable bacteria, that represent a tiny fraction of soil and root-associated bacteria. In this study, a metagenomics approach (Handelsman, 2004) was employed to access the hidden diversity of uncultivable soil bacteria that revealed a QQ enzyme, an NAHL lactonase, in these bacteria (Riaz et al., 2008).

Digoxin use in congestive heart failure. Current status

The use of digitalis in congestive heart failure with normal sinus rhythm is still debated. While older uncontrolled, withdrawal studies from 1969 to 1983 provided incomplete data, with poorly documented clinical status and poor haemodynamic and exercise data, some patients did improve clinically when digitalis treatment was utilised. Randomised, double-blind, placebo-controlled trials from 1977 to 1991 were of better quality but still short in duration, with small sample sizes and still with incomplete haemodynamic and exercise data. In 1993, the Prospective Randomised Study of Ventricular Failure and Efficacy of Digoxin (PROVED) and Randomised Assessment of Digoxin on Inhibitors of the Angiotensin-Converting Enzyme (RADIANCE) study, followed in 1997 by the Digitalis Investigation Group (DIG) trial, documented that digoxin prevents clinical deterioration and hospitalisations, and improves exercise tolerance and left ventricular function, but has no effect on survival. A substudy of the DIG trial showed no detrimental effect of digoxin on survival in patients with ejection fraction (EF) of > 45%, i.e. left ventricular (LV) diastolic dysfunction. Therefore, digoxin appears to be the first inotrope with no detrimental effect on survival in heart failure. In addition, the neurohormonal effect of digoxin has been documented, and is possibly present with dosages even lower than 0.25 mg. Finally, it has been determined that patients with only mild heart failure do obtain documented benefit from administration of this drug.