Myocardial perfusion imaging versus biochemical markers in acute coronary syndromes

The assessment and appropriate clinical management of patients with acute chest pain and non-diagnostic electrocardiograms remain a continuing clinical problem. Accordingly, there is considerable interest in evaluating new strategies to improve early diagnostic accuracy in patients with possible acute myocardial ischaemia. Cardiac troponins (T and I) and acute rest myocardial perfusion imaging have similar sensitivities for detecting acute myocardial infarction. Whereas cardiac markers require 6-12 h to become positive, acute rest myocardial perfusion imaging immediately reflects the status of regional myocardial blood flow at the time of radiopharmaceutical injection. The measurement of cardiac troponins is particularly useful in the diagnosis and estimation of the degree of myocardial injury in those patients with a high likelihood of coronary artery disease and myocardial necrosis and for prognostication of adverse cardiac events in those patients with unstable angina. In contrast, the most appropriate use of acute rest myocardial perfusion imaging is in the setting of patients with acute ischaemic symptoms, non-diagnostic electrocardiogram and a low likelihood of myocardial necrosis, in which early imaging will assist in effective triage decisions.     

Arsenic in drinking water and skin lesions: dose-response data from West Bengal,India

BACKGROUND: Over 6 million people live in areas of West Bengal, India, where groundwater sources are contaminated with naturally occurring arsenic. The key objective of this nested case-control study was to characterize the dose-response relation between low arsenic concentrations in drinking water and arsenic-induced skin keratoses and hyperpigmentation. METHODS: We selected cases (persons with arsenic-induced skin lesions) and age- and sex-matched controls from participants in a 1995-1996 cross-sectional survey in West Bengal. We used a detailed assessment of arsenic exposure that covered at least 20 years. Participants were reexamined between 1998 and 2000. Consensus agreement by four physicians reviewing the skin lesion photographs confirmed the diagnosis in 87% of cases clinically diagnosed in the field. RESULTS: The average peak arsenic concentration in drinking water was 325 microg/liter for cases and 180 microg/liter for controls. The average latency for skin lesions was 23 years from first exposure. We found strong dose-response gradients with both peak and average arsenic water concentrations. CONCLUSIONS: The lowest peak arsenic ingested by a confirmed case was 115 microg/liter. Confirmation of case diagnosis and intensive longitudinal exposure assessment provide the basis for a detailed dose-response evaluation of arsenic-caused skin lesions.     

Novel treatment of atrophic rhinitis: early results

The aim of this randomized control trial, performed at a tertiary referral hospital, was to compare the therapeutic effectiveness of two novel treatment modalities, oral rifampicin and submucosal placentrex injection, in randomly selected patients of primary atrophic rhinitis regarding objective, subjective and histopathological improvement. Patients treated with oral rifampicin showed most promising results regarding objective, subjective and histopathological improvement with maximum disease-free interval on regular follow-up as compared to submucosal placentrex injections.     

Poly-lactide-co-glycolide nanoparticles containing voriconazole for pulmonary delivery: in vitro and in vivo study

Poly-lactide-co-glycolide nanoparticles (207–605 nm) containing voriconazole (VNPs) were developed using a multiple-emulsification technique and were also made porous during preparation in presence of an effervescent mixture for improved pulmonary delivery. Pulmonary deposition of the particles was studied using a customized inhalation chamber. VNPs had a maximum of 30% (w/w) drug loading and a zeta potential (ZP) value around ? 20 mV. In the initial 2 hours, 20% of the drug was released from VNPs, followed by sustained release for 15 days. Porous particles had a lower mass median aerodynamic diameter (MMAD) than nonporous particles. Porous particles produced the highest initial drug deposition (~ 120 μg/g of tissue). The drug was detectable in lungs until 7 days and 5 days after administration, for porous and nonporous particles, respectively. VNPs with improved drug loading were successfully delivered to murine lungs. Porous nanoparticles with lower MMADs showed better pulmonary deposition and sustained presence in lungs.From the Clinical EditorIn this paper, voriconazole-containing porous nanoparticles were studied for inhalational delivery to lung infections in a murine model, demonstrating prolonged half-life and improved pulmonary deposition.     

Carotid body chemoreception in the absence and presence of CO2-HCO3-.

Carotid body (CB) chemosensory responses to natural and pharmacological stimuli were studied in vitro in the presence and nominal absence of CO2-HCO3- in the perfusion-superfusion media. The CBs obtained from cats (n = 10), anesthetized with sodium pentobarbitone, were simultaneously perfused and superfused with a modified Tyrode solution at 36.5 +/- 0.5 degrees C, equilibrated respectively with PO2 of 120 and less than 20 Torr. The Tyrode, nominally free of CO2-HCO3- (HEPES-NaOH, pH 7.38, 310 mOsm), was used first. Subsequently the Tyrode containing HEPES-HCO3-, equilibrated with PCO2 of 36.8 Torr (pH 7.38) was used. Chemosensory discharges were recorded from the carotid sinus nerve. Both hypoxia (PO2 = 20-25 Torr) and ischemic hypoxia stimulated the discharge in the absence and presence of CO2-HCO3-. However, the presence of CO2-HCO3- significantly raised the baseline activity, augmented the speed, sensitivity and the maximal responses to both types of hypoxia. Hypercapnic perfusate (PCO2 = 65 Torr at pH 7.17) produced a peak response equally promptly in the absence and presence of CO2-HCO3- in the ongoing perfusate but generated a larger and more sustained response. Presence of CO2-HCO3- strongly potentiated the responses to cyanide (10(-10)-10(-7) mol) but less strikingly the responses to nicotine (10(-11)-10(-8) mol). Thus, the extracellular CO2-HCO3- significantly improved the response to hypoxia but was not essential for O2 chemoreception. The underlying mechanisms of the effect of CO2-HCO3- is likely to be mediated by the Cl(-)-HCO3- anion exchanger in the pH regulation of glomus cells.     

Preventing gastric regurgitation with a ballooned nasogastric tube.

Regurgitation and aspiration of gastric contents remain a major source of morbidity and mortality in the perioperative period. A modified nasogastric tube has been designed with an integral balloon which is inflated in the stomach and impacted, by gentle traction, at the gastro-oesophageal junction, to prevent gastro-oesophageal reflux. Preliminary studies demonstrate its effectiveness in improving the competence of the gastro-oesophageal sphincter.