Predictors of Nocturnal Oxygen Desaturation in Normoxemic Patients with Moderate to Very Severe Chronic Obstructive Pulmonary Disease.

Introduction: COPD is associated with complications suchas reduced oxygen saturation and hypoventilation duringsleep and is underdiagnosed among normoxemic patients. Toidentify the daytime parameters to predict nocturnal oxygendesaturation in normoxemic patients with moderate to verysevere chronic obstructive pulmonary disease. To correlate thepresence of nocturnal oxygen desaturation with pulmonaryhypertension.Material and methods: A cross-sectional study wasperformed at ACS medical college Chennai for 14 monthsfrom May 2017 to June 2018. The study population included103 participants. Data on variables such as 6-minute walk test,spirometry, nocturnal oximetry, partial pressures of O2 andCO2 were assessed.Results: A total of 103 patients were included in the analysiswith 93.2% males and 3.9% current smokers and 87.4%ex-smokers. 52.4% had a normal chest X-ray. Around45.6% had hyperinflated lungs. In the 6 minutes-walktest, 32% participants had desaturation. 50.5% had positiveC-reactive protein levels indicating the presence of systemicinflammation. Right atrial/right ventricular dilatation wasnoted among 34% participants. Nocturnal desaturation with3 to 4 episodes/hour was present among 39% participants.Univariate analysis results show that post FEV 1, partialpressure of oxygen and carbon dioxide, presence ofdesaturation and RA/RV dilatation on echocardiography wereall statistically significant predictors of nocturnal oxygendesaturation in normoxemic patients with moderate to verysevere Chronic Obstructive Lung Disease.Conclusion: Screening the COPD patients for these daytimepredictors will enable in identifying the patients who havenocturnal desaturation. This in turn will aid in early initiationof home oxygen therapy.

Production, purification and properties of fungal chitinases—A review.

After cellulose, chitin is the second most abundant organic and renewable polysaccharide in nature. This polymer is degraded by enzymes called chitinases which are a part of the glycoside hydrolase family. Chitinases have many important biophysiological functions and immense potential applications especially in control of phytopathogens, production of chito-oligosaccharides with numerous uses and in treatment and degradation of chitinous biowaste. At present many microbial sources are being explored and tapped for chitinase production which includes potential fungal cultures. With advancement in molecular biology and gene cloning techniques, research on fungal chitinases have made fast progress. The present review focuses on recent advances in fungal chitinases, containing a short introduction to types of chitinases, their fermentative production, purification and characterization and molecular cloning and expression.