[Prevalence and risk factors of respiratory viral infection in acute exacerbation of chronic obstructive pulmonary disease].

Objective: To study the prevalence of respiratory viral infection in chronic obstructive pulmonary disease(COPD) exacerbations and to find the factors associated with susceptibility to viral infections. Methods: Eighty patients with exacerbations of COPD and 50 stable COPD patients were recruited. Nasopharyngeal swabs were tested for a range of 18 different respiratory viruses using PCR. Results: Among the COPD exacerbations, viral infection was detected in 18 episodes (22.5%) . The most common virus was rhinovirus (33.3%), followed by coronavirus(27.8%), parainfluenza(22.2%), metapneumovirus(11.1%) and influenza virus B(5.6%). The prevalence of viral infection was 8% in the stable COPD patients. In multivariate regression analysis fever was found to be significantly associated with viral infections in COPD exacerbations (Odds ratio 4.99, 95%CI 1.51-16.48, P=0.008). Conclusion: Viral respiratory pathogens were more often detected in respiratory specimens from hospitalized patients with AECOPD than those with stable COPD. Rhinovirus was the most common infecting agent identified. The symptom of fever was associated with viral detection.

[The derivation and validation of a scoring system for identifying patients with bronchiectasis at risk of exacerbations].

OBJECTIVE: To create and verify a scoring system for identifying patients with bronchiectasis at risk of exacerbations. METHODS: Derivation of the scoring system used data from a retrospective cohort study enrolling 228 patients with bronchiectasis. Multivariable logistic regression analysis was performed to identify independent predictors associated with exacerbations. ß-coefficients derived from the independent predictors in our logistic regression model were applied to create a scoring system (Total score was 8). The scoring system was then validated in a prospective cohort enrolling 334 patients with bronchiectasis. RESULTS: The derivation study showed that age ≥ 60 years (OR=2.583, 95%CI: 1.188-5.613), BMI<18.5 kg/m(2) (OR=2.991, 95%CI: 1.112-8.042), high medical research council dyspnea score (OR=7.905, 95%CI: 4.288-8.309), Pseudomonas aeruginosa colonization (OR=3.227, 95%CI: 1.041-9.004), the lobes involved on high-resolution computed tomography≥3 (OR=3.179, 95%CI: 1.449~6.976), prior intensive care unit admissions (OR=2.499, 95%CI: 1.301-4.801), and FEV1<50% predicted(OR=2.497, 95%CI: 1.421-5.080) were the independent predictors associated with exacerbations. The scoring system predicted exacerbations with an area under the receiver operator characteristic curve (AUC) of 0.79 (95% confidence interval, 0.74-0.84). In the validation cohorts, the total score ranged 0 to 6. There was significant difference in exacerbation frequency and quality of life between patients classified as low(0-2), intermediate(3-4), and high(5-8) risks by the scoring system (P<0.05). A higher score was associated with higher risk of exacerbations and poorer quality of life. CONCLUSION: Our scoring system was an efficient clinical predictive tool to identify patients with bronchiectasis at risk of exacerbations. It may be useful for early prevention of bronchiectasis exacerbations and for proper management.

[Correlation between red cell distribution width and the severity and prognosis of chronic thromboembolic pulmonary hypertension].

OBJECTIVE: To explore the relationship between circulating red cell distribution width (RDW) and the severity and prognosis of chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: A total of 66 consecutive patients with very likely CTEPH diagnosed by echocardiography and/or right heart catheterization were enrolled from August, 2007 to July, 2014. The patients included 31 females and 35 males with a mean age of (58±13) years. Based on the cut-off value of RDW=14%, the patients were divided into 2 groups as RDW>14% group(n=21) and RDW≤14% group(n=45). The baseline profile was recorded and compared between the 2 groups and the follow-up outcomes were analyzed by ROC curves and Logistic regression survival analysis. RESULTS: The median of follow-up time was 2 years, including 21 dead and 45 survived patients. The RDW level was positively related to creatinine(r=0.258, P=0.037), BNP(r=0.263, P=0.033) and uric acid(r=0.359, P<0.010). ROC analysis showed that RDW, BNP, and uric acid were the effective predictors for all-cause mortality in CTEPH patients(P<0.001, P=0.038, respectively), the area under the curve being 0.734, 0.806, and 0.659 respectively. Based on the cut-off value of 14%, the sensitivity and specificity for RDW prediction for CTEPH mortality was 60% and 80% respectively. The RDW≤14% group had better prognosis than the RDW>14% group (P<0.001). Moreover, the levels of BNP and uric acid were higher in the RDW>14% group than those in the RDW≤14% group(U=-3.558, P<0.05). Multi-Logistic regression analysis showed that RDW>14% was an independent risk factor for predicting death in CTEPH patients. CONCLUSIONS: RDW level was inversely related to the clinical condition and prognosis of CTEPH. Higher RDW, as an independent risk factor for adverse events, was correlated with severity and worse prognosis of the disease.

Three approaches to the analysis of trace formaldehyde in bulk and dosage from pharmaceuticals.

Trace-level determinations for the presence of formaldehyde in both bulk and dosage form pharmaceuticals were developed using three innovative strategies. One system adapted the chromotropic acid spot test for formaldehyde. This was accomplished spectrophotometrically over a linear detection range against authentic control samples. The other two chromatographic approaches necessitated rapid derivatization. One derivative was its corresponding oxime, formaldoxime, which was resolved on a gas chromatographic porous polymer column and sensed by a nitrogen-specific detector. The other derivative, sodium formate, was detected and quantified on an ion chromatograph using an anion-exchange column and a conductivity detector. The chromotropic acid technique was sensitive but not specific for formaldehyde. The chromatographic techniques required a high degree of water solubility. All were subject to interferences that could preclude their use for a particular application. None of the tested samples, which included a penicillin analogue, a pharmaceutical dosage from additive, a vitamin, and biological proteins, showed the presence of formaldehyde at trace levels.

Validation of washing procedures for maintaining a microbiologically clean gel filtration column.

Chromatographic gel filtration matrixes used in various separation techniques are subject to microbial contamination. The need for a microbe-free column is critical when preparing materials that require a low or zero microbial count. This report proposes two alternative washing systems: 0.02 N HCl containing 0.81% NaCl, and 0.1 M tromethamine--hydrochloride buffer (pH 7.0) containing 0.81% NaCl and 0.02% thimerosal. These washing systems were validated using a 100 x 2.6-cm column packed with a modified dextran gel slurry previously inoculated with known counts of USP test organisms. After each wash, the column separation characteristics were verified further with appropriate test proteins.

Methods for storage of antimicrobial effectiveness test inoculum suspensions below freezing.

Studies were conducted to determine the suitability of storage below freezing of some antimicrobial effectiveness test inoculum organisms: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. Several solutions used for protecting microorganisms subjected to storage below freezing were compared. Comparison of 10% dextrose with other solutions (distilled water; 0.07 M phosphate buffer, H 7.0, with 15% glycerol; and 0.07 M phosphate buffer, pH 7.0, with 7.5% dimethyl sufoxide) demonstrated that inoculum suspensions were most stable when prepared with 10% dextrose. After storage for 6 months at-50 degrees in a freezer, inoculum suspensions prepared with 10% dextrose retained viability and demonstrated suitability for use in antimicrobial effectiveness tests of dosage forms containg preservatives.

Quantitative methods for the gas chromatographic characterization of acidic fermentation by-products of anaerobic bacteria.

The present report describes improved chromatographic procedures which are capable of separating and quantitating complex mixtures of acidic fermentation by-products produced by anaerobic bacteria grown in two glucose-containing media. These methods are reliable and are sensitive, being able to detect as low as 0.5 mumoles of each by-product. Sample preparation has been simplified, and the methylation conditions have been optimized. It is also indicated in this investigation that each culture produced different patterns of by-products in each medium, indicating that the types and quantities of by-products produced in one medium cannot be used as a basis for characterization of these same cultures when grown in a different medium. Finally, it is shown that cultures can be characterized by the distinctive molar proportions of by-products they produce within each medium.