Urinary excretion of platinum (Pt) following skin and respiratory exposure to soluble Pt at South African precious metals refineries

Adverse respiratory and skin health effects have been associated with occupational exposure to soluble platinum (Pt). However, the relationship between skin exposure and urinary Pt excretion has not yet been investigated. In this study we examined the relationship between skin and respiratory exposure to soluble Pt and urinary Pt excretion at two South African precious metals refineries.The skin and respiratory exposure to soluble Pt as well as the urinary Pt excretion of forty precious metals refinery workers was assessed simultaneously using Ghostwipes?, Methods for the Determination of Hazardous Substances method 46/2 and spot urine tests, respectively.The geometric mean for skin exposure to soluble Pt on four anatomical positions (palm, wrist, neck and forehead) was 0.008?μg/cm² [95% confidence interval (CI): 0.005-0.013?μg/cm²], while the geometric mean for respiratory exposure was 0.301?μg/m³ (95%CI: 0.151-0.601?μg/m³) and the geometric mean for urinary Pt excretion was 0.212?μg/g creatinine (95%CI: 0.169-0.265?μg/g creatinine). Partial correlations identified significant positive correlations between skin exposure, respiratory exposure and urinary Pt excretion (r?=?0.580 to 0.754).Skin and respiratory exposures to soluble Pt were both positively correlated with urinary Pt excretion, and both exposure routes should be considered when investigating occupational exposure to soluble Pt.     

Prevalence of scoliosis and impaired pulmonary function in patients with type III osteogenesis imperfecta

European Spine Journal - Osteogenesis Imperfecta (OI) is a rare group of congenital genetic disorders that consists of a collagen synthesis defect. The most severe phenotype is type III OI....     

Rash Impulsiveness and Reward Sensitivity as predictors of treatment outcome in male substance dependent patients

Recent theories hypothesize that the impulsivity observed in addictive behaviors is a two-factor construct, consisting of Rash Impulsiveness and Reward Sensitivity. There is some evidence for this distinction, but it is unknown what the clinical relevance of this distinction is. The present study examines the predictive value of the two-factor model regarding drop-out from treatment and relapse into substance use in a clinical population of male substance dependent patients. Both behavioral and self-report measures of Rash Impulsiveness and Reward Sensitivity were measured during treatment while substance use relapse was measured after 90 days. Results indicate that treatment drop-out could be predicted by a behavioral index of Reward Sensitivity (Card Playing Task); self-reported Rash Impulsiveness only approached significance as predictor drop-out. In contrast, relapse could not be predicted in the present study. These findings might have implications for the early identification and treatment of patients at risk of treatment drop-out.     

Intuitive user interfaces increase efficiency in endoscope tip control

Background

Flexible endoscopes are increasingly used to perform advanced intraluminal and transluminal interventions. These complex interventions demand accurate and efficient control, however, current endoscopes lack intuitiveness and ergonomic control of the endoscope tip. Alternative handheld controllers can improve intuitiveness and ergonomics, though previous studies are inconclusive concerning their effect on the efficiency of endoscope manipulation. The aim of this study is to determine the efficiency of a robotic system with intuitive user interface in controlling the tip of the flexible endoscope.

Methods

We compared the efficiency of time and tip trajectory when steering the endoscope tip using the conventional steering wheels and a robotic platform with three different user interfaces: a touchpad in combination with a position control algorithm, a joystick combined with linear rate control, and a joystick combined with non-linear rate control. Fourteen participants, without a medical background, used all four interfaces. They performed both large navigational and fine targeting tasks in a simulated environment which allowed objective cross-subject comparison. Afterward, the participants were asked to select their preferred steering method.

Results

Participants were significantly faster in steering the endoscope tip when using robotic steering compared to using the conventional steering method. Between the robotic interfaces, using the touchpad was significantly faster compared to the joystick with linear rate control. Use of the joystick with non-linear rate control led to a shorter tip trajectory compared to the touchpad. The majority of participants preferred the joystick with non-linear rate control over the other steering methods.

Conclusions

This work shows that intuitive user interfaces can improve the efficiency of endoscope tip steering.     

The in vivo expressed Mycobacterium tuberculosis (IVE-TB) antigen Rv2034 induces CD4 T-cells that protect against pulmonary infection in HLA-DR transgenic mice and guinea pigs

Tuberculosis (TB) remains a life-threatening infectious disease of global proportions with serious negative health and economic consequences. The lack of sufficient protection induced by Mycobacterium bovis BCG, the current vaccine for TB, as well as the impact of HIV co-infection and the emergence of drug resistant Mycobacterium tuberculosis (Mtb) strains all urge for improved vaccines against TB.     

Cycle-to-cycle control of swing phase of paraplegic gait induced by surface electrical stimulation

Parameterised swing phase of gait in paraplegics was obtained using surface electrical stimulation of the hip flexors, hamstrings and quadriceps; the hip flexors were stimulated to obtain a desired hip angle range, the hamstrings to provide foot clearance in the forward swing, and the quadriceps to acquire knee extension at the end of the swing phase. We report on two main aspects; optimisation of the initial stimulation parameters, and parameter adaption (control). The initial stimulation patterns were experimentally optimised in two paraplegic subjects using a controlled stand device, resulting in an initial satisfactory swinging motion in both subjects. Intersubject differences appeared in the mechanical output (torque joint) per muscle group. During a prolonged open-loop controlled trial with the optimised but unregulated stimulation onsets and burst duration for the three muscle groups, the hip angle range per cycle initially increased above the desired value and subsequently decreased below it. The mechanical performance of the hamstrings and quadriceps remained relatively unaffected. A cycle-to-cycle controller was then designed, operating on the basis of the hip angle ranges obtained in previous swings. This controller successfully adapted the burst duration of the hip flexors to maintain the desired hip angle range.     

Left ventricular ejection fraction and volumes from gated single photon emission tomographic myocardial perfusion images: Comparison between two algorithms working in three-dimensional space

Objective. Two different algorithms operating in three-dimensional space, one dependent on surface detection developed at Cedars-Sinai Medical Center (CS) and another dependent on statistical parameters and developed at Stanford University Medical School (SU), were compared in the same patients to assess the left ventricular volumes and the left ventricular ejection fractions (LVEFs) from gated single-photon emission tomography (SPECT) myocardial perfusion images.Methods. Perfusion SPECT images gated in eight time bins were recorded in 40 patients with coronary artery disease 60 minutes after the injection of 925 MBq^99mTc-labeled tetrofosmin at rest. The LVEF values were validated against planar gated ^99mTc-labeled blood pool studies (ERNA).Results. The software success rates were 95% (38/40 patients) for CS and 100% for SU. Agreement between LVEFs measured with CS and SU and agreement between both methods and ERNA were excellent (LVEF_CS = 0.89LVEF_SU + 6.21, r = 0.93; LVEF_SU = 0.92LVEF_ERNA + 0.99, r = 0.94; and LVEF_CS = 0.88LVEF_ERNA + 4.58, r = 0.93). Bland-Altman plots showed that differences between LVEFs from SU and CS and from ERNA were similar across a wide range (20% to 80%) of LVEF values. No relationship between these differences and the severity of perfusion defects was observed. For left ventricular volumes, linear regression analysis showed an excellent correlation between both methods (end-diastolic volume R = 0.97 end-systolic volume R = 0.98), but systematically higher values were obtained with SU (p = 0.013).Conclusion. Measurements of LVEF obtained with CS and SU correspond well with those from the standard, ERNA, even in patients with severe perfusion defects. A close relationship is observed between SU and CS when left ventricular volumes are considered. Measurements of LVEF (and left ventricular volumes) should be considered as an integral part of myocardial perfusion studies whenever possible.