Source Identification of Particulate Matter in a Semi-urban Area of Malaysia Using Multivariate Techniques

This study aims to determine the composition and sources of particulate matter with an aerodynamic diameter of 10 μm or less (PM₁₀) in a semi-urban area. PM₁₀ samples were collected using a high volume sampler. Heavy metals (Fe, Zn, Pb, Mn, Cu, Cd and Ni) and cations (Na⁺, K⁺, Ca²⁺ and Mg²⁺) were detected using inductively coupled plasma mass spectrometry, while anions (SO₄ ^2?, NO₃ ^?, Cl^? and F^?) were analysed using Ion Chromatography. Principle component analysis and multiple linear regressions were used to identify the source apportionment of PM₁₀. Results showed the average concentration of PM₁₀ was 29.5 ± 5.1 μg/m³. The heavy metals found were dominated by Fe, followed by Zn, Pb, Cu, Mn, Cd and Ni. Na⁺ was the dominant cation, followed by Ca²⁺, K⁺ and Mg²⁺, whereas SO₄ ^2? was the dominant anion, followed by NO₃ ^?, Cl^? and F^?. The main sources of PM₁₀ were the Earth’s crust/road dust, followed by vehicle emissions, industrial emissions/road activity, and construction/biomass burning.     

Initial experience with single-source dual-energy CT abdominal angiography and comparison with single-energy CT angiography: image quality, enhancement, diagnosis and radiation dose

Objectives

To assess image quality of virtual monochromatic spectral (VMS) images, compared to single-energy (SE) CT, and to evaluate the feasibility of material density imaging in abdominal aortic disease.

Methods

In this retrospective study, single-source (ss) dual-energy (DE) CT of the aorto-iliac system in 35 patients (32 male, mean age 76.5 years) was compared to SE-CT. By post-processing the data from ssDECT, VMS images at different energies and material density water (WD) images were generated. The image quality parameters were rated on 5-point scales. The aorto-iliac attenuation and contrast-to-noise ratio (CNR) were recorded. Quality of WD images was compared to true unenhanced (TNE) images. Radiation dose was recorded and statistical analysis was performed.

Results

Image quality and noise were better at 70 keV (P?<?0.01). Renal artery branch visualisation was better at 50 keV (P?<?0.005). Attenuation and CNR were higher at 50 and 70 keV (P?<?0.0001). The WD images had diagnostic quality but higher noise than TNE images (P?<?0.0001). Radiation dose was lower using single-phase ssDECT compared to dual-phase SE-CT (P?<?0.0001).

Conclusion

70-keV images from ssDECT provide higher contrast enhancement and improved image quality for aorto-iliac CT when compared to SE-CT at 120 kVp. WD images are an effective substitute for TNE images with a potential for dose reduction.

Key Points

? Multi-detector computed tomography (MDCT) angiography is now a routine procedure. ? Single-source dual-energy CT (ssDECT) can provide simultaneous data with different kilovoltages. ? 70 keV images showed better image quality than conventional single-energy (SE) CT. ? 70 keV images exhibited less image noise in comparison to SE-CT.     

Perspectives of leprosy patients on MDT services after integration of NLEP functions into primary health care

Sixty-five leprosy patients residing in rural Digapahandi block of Ganjam district were studied during July-August 2001 in order to ascertain their perspectives regarding different MDT services after NLEP functions were integrated into primary health care (PHC) in Orissa after September 1999. They included 43.08% multibacillary (MB) cases and 61.92% paucibacillary (PB) cases. Assessment was done by personal interviews of adult patients and the parents of child cases after verification of their treatment cards at the sub-centre. Patient's knowledge regarding the availability of MDT services under PHC services and utilization of these services were highlighted. Influence of different socio-demographic factors was also studied. Basing on the study results, recommendations were made for sustained NLEP functions through PHC in order to improve the utilization of MDT services, which will help in the elimination of leprosy.     

Uric Acid as a Potential Biomarker of Pulmonary Arterial Hypertension in Patients with Sickle Cell Disease

Serum uric acid (UA) is emerging as a strong and independent marker for pulmonary arterial hypertension (PAH). PAH is well recognized as a life threatening complication of sickle cell disease (SCD). However, the association between UA and PAH in SCD is unknown. We reviewed electronic medical records (EMR) of 559 consecutive adult SCD patients from Kings County Hospital Center (KCHC) between January 2005 and February 2010. Patients (n = 96) with measurement of UA in close temporal proximity to the transthoracic echocardiography (TTE) were identified. PAH was defined as pulmonary artery systolic pressure (PASP) ≥30 mm Hg. Patients (n = 16) with other risk factors which may cause PAH and chronic renal insufficiency were excluded. In 18 patients, TTE could not measure PASP. Finally, 62 patients were selected. Statistical analysis was performed using Student t tests, Pearson correlation coefficient and multivariate regression analysis. Out of 62 patients, 30 had PAH. Patients with PAH had a higher UA level (8.67 ± 4.8 vs. 5.35 ± 2.1, P = 0.001). We found strong positive correlation between the UA level and PASP (r = 0.71; P < 0.0001). This correlation was independent of diuretic use. UA could be a potential marker for PAH in SCD. However, its’ prognostic and pathophysiologic role in SCD patients with PAH needs to be further investigated.     

Acute esophageal necrosis: a case series of five patients presenting with “Black esophagus”

Acute esophageal necrosis (AEN), also known as “Black esophagus”, is a rare condition that typically presents as upper gastrointestinal hemorrhage. A retrospective chart analysis was conducted at two tertiary care hospitals over a three-year period (2005–2007) using a computerized inpatient database. Out of 9,179 upper endoscopies performed, five patients (0.05% prevalence) were found to have black esophagus. Their mean age was 44 years and the most common presentation was upper gastrointestinal bleeding. All five patients had comorbid conditions, most commonly coronary artery disease, diabetes mellitus, and renal insufficiency. Two patients died, but the cause of death was not related to AEN in either. In conclusion, AEN is usually seen in critically ill elderly patients with multiple comorbid conditions, particularly vascular disease, diabetes mellitus and azotemia.     

The impact of twice-daily consultant ward rounds on the length of stay in two general medical wards

Excess average length of stay (ALoS) not only results in an increased cost to hospitals but also increases the risk of hospital-acquired infection and thromboembolism. Various factors suggested to affect ALoS have yet to demonstrate a significant impact in clinical practice. Increased consultant input has been identified as an important factor influencing ALoS. As a result, a radical and innovative consultant job plan, replacing twice-weekly with twice-daily ward rounds (WRs) on a university teaching hospital's two medical words has been designed. The number of discharges (NoDs) significantly increased (p < 0.01), ALoS reduced (p < 0.01), whereas, readmission rate and mortality remained unchanged (p = NS) over 12 months following twice-daily WRs compared to two other wards with twice-weekly WRs. This innovative model resulted in almost doubling the NoDs and halving the ALoS. This study suggests that ALoS can be reduced and sustained with a cultural and behavioural shift in consultant working patterns, without affecting readmission rate or inpatient mortality.     

FOLFIRINOX in Locally Advanced Pancreatic Cancer: The Massachusetts General Hospital Cancer Center Experience

The objective of our retrospective institutional experience is to report the overall response rate, R0 resection rate, progression‐free survival, and safety/toxicity of neoadjuvant FOLFIRINOX (5‐fluorouracil [5‐FU], oxaliplatin, irinotecan, and leucovorin) and chemoradiation in patients with locally advanced pancreatic cancer (LAPC). Patients with LAPC treated with FOLFIRINOX were identified via the Massachusetts General Hospital Cancer Center pharmacy database. Demographic information, clinical characteristics, and safety/tolerability data were compiled. Formal radiographic review was performed to determine overall response rates (ORRs). Twenty‐two patients with LAPC began treatment with FOLFIRINOX between July 2010 and February 2012. The ORR was 27.3%, and the median progression‐free survival was 11.7 months. Five of 22 patients were able to undergo R0 resections following neoadjuvant FOLFIRINOX and chemoradiation. Three of the five patients have experienced distant recurrence within 5 months. Thirty‐two percent of patients required at least one emergency department visit or hospitalization while being treated with FOLFIRINOX. FOLFIRINOX possesses substantial activity in patients with LAPC. The use of FOLFIRINOX was associated with conversion to resectability in >20% of patients. However, the recurrences following R0 resection in three of five patients and the toxicities observed with the use of this regimen raise important questions about how to best treat patients with LAPC.