Mass Spectrometry Provides Warning of Carbon Monoxide Exposure Via Trifluoromethane

Background: The chemical breakdown of isoflurane, enflurane, or desflurane in dried carbon dioxide absorbents may produce carbon monoxide. Some mass spectrometers can give false indications of enflurane during anesthetic breakdown.

Methods: During clinical anesthesia with isoflurane or desflurane, the presence of carbon monoxide in respiratory gas was confirmed when enflurane was inappropriately indicated by a clinical mass spectrometer that identified enflurane at mass to charge ratio = 69. In vitro, isoflurane, enflurane, or desflurane in oxygen was passed through dried carbon dioxide absorbents at 35, 45, and 55 degrees C. Gases were analyzed by gas chromatography and by mass spectrometry.

Results: Mass spectrometry identified several clinical incidents in which 30-410 ppm carbon monoxide was measured in respiratory gas. Trifluoromethane was produced during in vitro breakdown of isoflurane or desflurane. Although these inappropriately indicated quantities of "enflurane" correlated (r2 > 0.95) to carbon monoxide concentrations under a variety of conditions, this ratio varied with temperature, anesthetic agent, absorbent type, and water content.     

Does the scleral encircling band provide a protective effect against the progression of diabetic retinopathy?

AIM: To evaluate the effect of scleral encircling bands on the development and progression of diabetic retinopathy (DR) in diabetic patients. METHODS: The medical records of diabetic patients who underwent unilateral retinal detachment (RD) surgery using scleral buckle and encircling band were reviewed retrospectively. Both eyes of patients were included in the study: one eye in each patient had a scleral buckle with encircling band (the operated eye) and the other one is the non-operated eye. The demographic characters, duration of diabetes and period between surgery and the last recall visit were retrieved from each patient. All the cases underwent fundus photo and fluorescein angiography (when indicated) to confirm the DR staging. RESULTS: Totally 25 patients fulfilled the inclusion and the exclusion criteria were become eligible for the study. A total of 50 eyes of 25 patients were enrolled in this analysis. The mean period of time passed from surgery with encircling band and the last reassessment visit was 12.5±2y. Even though DR could develop in the operated eyes, it was at a less degree of severity compared to the non-operated eyes of same patients (P=0.027). CONCLUSION: Scleral encircling bands have protective effects against the development and progression of DR.     

Enterotoxigenic Bacteroides fragilis-associated diarrhea in children 0-2 years of age in rural Bangladesh

The burden of enterotoxigenic Bacteroides fragilis (ETBF)-related diarrhea was determined in a birth cohort of 252 children in rural Bangladesh. Isolation rates of ETBF in stool and risk factors for acquisition of ETBF and disease were established. Of 382 B. fragilis-positive specimens, 14.4% of the strains found in them produced enterotoxin, as determined by a tissue-culture assay. The overall isolation rate of ETBF was 2.3% (40/1750) from diarrheal specimens and 0.3% (15/5679) from nondiarrheal specimens collected throughout the 2 years of the study (P < .001). ETBF was isolated from 20.3% (40/197) of the B. fragilis-positive diarrheal specimens and from 8.1% (15/185) of the B. fragilis-positive nondiarrheal specimens (P < .001) and was significantly associated with acute diarrheal disease in children > or = 1 year of age (P = .0001). The diarrheal illness was mild in nature. In conditional multivariate analyses that examined environmental and host risk factors, the presence of livestock in the household area was linked to the acquisition of ETBF (chickens, P < .05; cows, P = .06). ETBF was found to be a small but significant contributor to diarrheal disease in this rural community. Improved management of livestock may be useful for the prevention of ETBF infection.     

Mechanisms by which epoxyeicosatrienoic acids (EETs) elicit cardioprotection in rat hearts

Cytochrome P450 (CYP) epoxygenases and their arachidonic acid (AA) metabolites, the epoxyeicosatrienoic acids (EETs), have been shown to produce reductions in infarct size in canine myocardium following ischemia-reperfusion injury via opening of either the sarcolemmal K(ATP) (sarcK(ATP)) or mitochondrial K(ATP) (mitoK(ATP)) channel. In the present study, we subjected intact rat hearts to 30 min of left coronary artery occlusion and 2 h of reperfusion followed by tetrazolium staining to determine infarct size as a percent of the area at risk (IS/AAR, %). The results demonstrate that the two major regioisomers of the CYP epoxygenase pathway, 11,12-EET (2.5 mg/kg, iv) and 14,15-EET (2.5 mg/kg, iv) significantly reduced myocardial infarct size (IS/AAR, %) in rats as compared with control (41.9+/-2.3%, 40.9+/-1.2% versus 61.5+/-1.6%, respectively), whereas, a third regioisomer, 8,9-EET (2.5 mg/kg, iv) had no effect (55.2+/-1.4). The protective effect of pretreatment with 11,12- and 14,15-EETs was completely abolished (61.9+/-0.7%, 58.6+/-3.1%, HMR; 63.3+/-1.2%, 63.2+/-2.5%, 5-HD) in the presence of the selective sarcK(ATP) channel antagonist, HMR 1098 (6 mg/kg, iv) or the selective mitoK(ATP) channel antagonist, 5-HD (10 mg/kg, iv) given 10 min after 11,12- or 14,15-EET administration but 5 min prior to index ischemia. Furthermore, concomitant pretreatment with 11,12- or 14,15-EET in combination with the free radical scavenger, 2-mercaptopropionyl glycine (2-MPG), at a dose (20 mg/kg, iv) that had no effect on IS/AAR (57.7+/-1.3%), completely abolished the cardioprotective effect of 11,12- and 14,15-EETs (58.2+/-1.6%, 61.4+/-1.0%), respectively. These data suggest that part of the cardioprotective effects of EETs in rat hearts against infarction is the result of an initial burst of reactive oxygen species (ROS) and subsequent activation of both the sarcK(ATP) and mitoK(ATP) channel.     

Surgical excision of a cardiac hydatid cyst from the right ventricle in a child

Reporting the rare cardiac localization of hydatid disease in the right ventricle of a child, and underlining the importance of early diagnosis and treatment to avoid severe and life‐threatening complications.     

Topical delivery of retinyl ascorbate co-drug. 1. Synthesis, penetration into and permeation across human skin

A novel synthetic technique was used to synthesise the co-drug retinyl ascorbate (RA-AsA) ester from all-trans-retinyl chloride (RA) and L-ascorbic acid (AsA) suspended in ethanol at low temperature. Its log P, solubility in a Me:PBS, 50/50 at pH 4.8 and degradation constant were determined. The flux and permeation coefficient were determined using heat separated human skin membrane, and skin penetration was determined by tape stripping using full thickness human. All experiments were performed in parallel with retinyl palmitate (Rol-Pal) and ascorbyl palmitate (AsA-Pal), which are used in commercial topical formulations. RA-AsA exhibited favourable log P (2.2), with stability much greater than RA and AsA, but similar stability to Rol-Pal and AsA-Pal. The flux of RA-AsA was lower than for Rol-Pal and AsA-Pal. RA-AsA also demonstrated higher skin retention than the other two esters, but delivered more RA and AsA to the viable epidermis than retinol from Rol-Pal and ascorbic acid from AsA-Pal. Overall, the data suggest the potential value of RA-AsA co-drug for the purpose of treating damage to skin resulting from UV-induced production of free radicals.     

Comparisons of hypertension-related costs from multinational clinical studies

BACKGROUND: This study identifies and compares the individual cost components of hospital and ambulatory services that manage the care of hypertensive patients in eight countries: the US, the UK, France, Spain, Germany, Italy, Canada and Australia. METHODS: Hypertension-related costs are classified according to four major cardiovascular events: (i) acute myocardial infarction; (ii) congestive heart failure; (iii) stroke; and (iv) renal failure, which was subdivided into renal failure treated by dialysis and renal failure treated by kidney transplantation. To make cross-country costs comparisons, we used the DRG codes used in the US and DRG-like codes from each country. US cost information was obtained from hypertension data available from the literature and health economics researchers. For costs in other countries, we consulted with national health economics experts in each country, used analyses by the Research Triangle Institute, and performed Medline and international literature searches. When available, we obtained information from the countries' public and private nationally representative data sources. For cross-country currency adjustments, all currencies were converted using the Purchasing Power Parities from the Organisation for Economic Cooperation and Development, and then converted into inflation-adjusted year 2000 US dollars. RESULTS: There exists considerable variation in hypertension-related costs from multinational clinical studies. This study documents that costs are generally higher in the US than in other countries; however, this is not always true. In particular, costs of treating heart failure in France and the costs of renal failure without transplantation in Germany and the UK are relatively high. DISCUSSION: While analysing multinational hypertensive cost data, this study also addresses the impact of cross-country cost variations on cost analyses. During the last decade, drug-development researchers have drawn extensively upon multinational trials to resolve enrollment problems and drug-registration issues. At the same time, formulary decision-makers are increasingly demanding multinational cost-effectiveness analyses of the clinical differences found between drug-treatment regimens. Since these data are typically not captured by randomised clinical trials, standard cost estimates must be applied to the clinical trials' resource data, although such standardised calculations do not necessarily account for clinical and cost variations between countries. CONCLUSION: This paper serves as an instrument for identifying which national and event cost data are comparable for analysis as well as highlighting specific problem areas for cost data integration. Although the study focuses on hypertension-related costs, its results may provide insight for multinational cost comparisons of other diseases where similar hospitalisation costs may be analysed.