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1.  Non-Invasive Microbial Metabolic Activity Sensing at Single Cell Level by Perfusion of Calcein Acetoxymethyl Ester 
PLoS ONE  2015;10(10):e0141768.
Phase contrast microscopy cannot give sufficient information on bacterial metabolic activity, or if a cell is dead, it has the fate to die or it is in a viable but non-growing state. Thus, a reliable sensing of the metabolic activity helps to distinguish different categories of viability. We present a non-invasive instantaneous sensing method using a fluorogenic substrate for online monitoring of esterase activity and calcein efflux changes in growing wild type bacteria. The fluorescent conversion product of calcein acetoxymethyl ester (CAM) and its efflux indicates the metabolic activity of cells grown under different conditions at real-time. The dynamic conversion of CAM and the active efflux of fluorescent calcein were analyzed by combining microfluidic single cell cultivation technology and fluorescence time lapse microscopy. Thus, an instantaneous and non-invasive sensing method for apparent esterase activity was created without the requirement of genetic modification or harmful procedures. The metabolic activity sensing method consisting of esterase activity and calcein secretion was demonstrated in two applications. Firstly, growing colonies of our model organism Corynebacterium glutamicum were confronted with intermittent nutrient starvation by interrupting the supply of iron and carbon, respectively. Secondly, bacteria were exposed for one hour to fatal concentrations of antibiotics. Bacteria could be distinguished in growing and non-growing cells with metabolic activity as well as non-growing and non-fluorescent cells with no detectable esterase activity. Microfluidic single cell cultivation combined with high temporal resolution time-lapse microscopy facilitated monitoring metabolic activity of stressed cells and analyzing their descendants in the subsequent recovery phase. Results clearly show that the combination of CAM with a sampling free microfluidic approach is a powerful tool to gain insights in the metabolic activity of growing and non-growing bacteria.
PMCID: PMC4625966  PMID: 26513257
2.  Diagnosis of idiopathic pulmonary fibrosis: Current issues 
Idiopathic pulmonary fibrosis (IPF) accounts for the majority of lung diseases classified as idiopathic interstitial pneumonia (IIP). It is considered to be lethal because prognosis is very poor and far worse than other types of IIP. An early and accurate diagnosis of IPF is critical. The diagnostic process is complex and requires a multidisciplinary approach involving a pulmonologist, radiologist and pathologist.
PMCID: PMC4428188  PMID: 25984423
Idiopathic pulmonary fibrosis; idiopathic interstitial pneumonia; diagnosis
3.  Assessment of clonal fidelity of Tylophora indica (Burm. f.) Merrill “in vitro” plantlets by ISSR molecular markers 
SpringerPlus  2014;3:400.
Tylophora indica Burm F. Merrill. is widely used against various diseases owing to the presence an array of medicinally important secondary metabolites. Its stem is bitter, stomachic, stimulates bile secretion, enriches the blood and cures diseases like diabetes, fever, flatulence, hypertension, jaundice, leucorrhoea, urinary disease and upper respiratory tract infection. It is neglected for tissue culture work because of deciduous nature of climbing shrub, facing problems for micropropagation. Hence, in vitro regeneration of complete plantlets was done through indirect organogenesis in Tylophora indica. Calli were produced from in vivo leaves of T. indica on MS medium supplemented with 6-Benzylaminopurine (BAP: 2.0 mg l-1) and Indole-3-butyric acid (IBA: 0.5 mg l-1). The multiple shoots (12.00 ± 1.50) emerged and elongated on MS medium fortified with Thidiazuron (TDZ: 0.1 mg l-1). They were rooted on half strength MS medium having IBA (0.5 mg l-1) (7.75 ± 0.25) after 20 days of sub-culturing followed by hardening and acclimatization. During indirect regeneration of plants, chances of somaclonal variations may arise. These variations should be identified to produce true to type plants. Plantlets raised through tissue culture were used to validate the clonal fidelity through Inter simple sequence repeat markers (ISSR). Clonal fidelity is a major consideration in commercial micropropagation using in vitro tissue culture methods. During the study, total 71 clear and distinct bands were produced using 6 primers. The banding pattern of each primer was uniform and comparable to mother plant and showed about 93% homology using un-weighted pair group method with arithmetic averaging (UPGMA). ISSR analysis confirmed the genetic stability of in vitro raised plants.
PMCID: PMC4147081  PMID: 25170431
Clonal fidelity; ISSR markers; Organogenic calli; Tylophora indica; UPGMA
4.  Swyer–James–MacLeod syndrome with ipsilateral herniation of hyperinflated hyperlucent lung 
BMJ Case Reports  2011;2011:bcr0520114191.
Swyer–James–MacLeod syndrome is characterised by unilateral hyperlucency on chest radiograph with small or normal-sized lung on the affected side and compensatory hyperinflation of opposite lung. Hyperinflation of the affected lung is a very rarely reported entity. An adult female patient, who presented with exertional breathlessness and diagnosed to have hypoplastic left pulmonary artery with hyperlucent, hyperinflated and herniated left lung is described.
PMCID: PMC3176363  PMID: 22679043
5.  A comparative study on the clinical and polysomnographic pattern of obstructive sleep apnea among obese and non-obese subjects 
Annals of Thoracic Medicine  2012;7(1):26-30.
This study was designed to compare the pattern of obstructive sleep apnea (OSA) among obese and nonobese subjects regarding clinical and polysomnographic data obtained for a polysomnographic study.
A cross-sectional retrospective descriptive study was conducted by analyzing polysomnographic data in 112 consecutive patients underwent a sleep study at our sleep laboratory from January 2009 to July 2010. Out of them, 81 were diagnosed to have OSA (apnea-hypopnoea Index ≥5). These patients were classified in two groups with body mass index (BMI) < 27.5 kg/m2 as nonobese and BMI≥27.5 kg/m2 as obese. Clinical as well as polysomnographic data were evaluated and compared between the two groups. Patients were also evaluated for other risk factors such as smoking, alcoholism, and use of sedatives. Data were subjected to statistical analysis (χ2-test, P value <0.05 considered to be significant). The Fisher Exact test was applied wherever the expected frequency for a variable was ≤5.
Of 81 patients with OSA, 36 (44.4%) were nonobese with a mean BMI of 26.62 ± 2.29 kg/m2 and 45 (55.6%) were obese with a mean BMI of 35.14 ± 3.74 kg/m2. Mean AHI per hour was significantly more in the obese than in the nonobese group (50.09 ± 29.49 vs. 24.36 ± 12.17, P<0.001). The use of one or more sedatives was more in nonobese as compared to obese (58.3% vs. 24.4%, P=0.002). The obese group had significantly higher desaturation and arousal index (P<0.001). The minimal oxygen saturation was lower in the obese than the nonobese group (68.5 ± 13.00 vs. 80.3 ± 7.40, P<0.001) and was well below 90% in both groups. Overall, the OSA in nonobese patients was mild-to-moderate as compared to that of the obese and no significant differences were observed between them as regard to age, gender, mean neck circumference, excessive daytime sleepiness, adenoid or tonsillar enlargement, smoking, and remaining polysomnographic parameters.
Obstructive sleep apnea can occur in nonobese persons though with less severity as compared to obese leading to a concept that OSA is not restricted to obese persons only and there is a high demand of its awareness regarding evaluation, diagnosis, and management in such individuals.
PMCID: PMC3277037  PMID: 22347347
Body mass index; obesity; obstructive sleep apnea

Results 1-5 (5)