Outcomes in lung cancer: An experience from routine tertiary care setting

BACKGROUND

The aim of this study was to establish characteristics of lung cancer patients diagnosed at a tertiary care hospital in Bangalore.

METHODS

The retrospective study was undertaken comprising of 202 patients diagnosed of advanced lung cancer in a tertiary care setting. Data was analyzed to identify patients' characteristics, smoking history, tumor histology, stage of the disease, treatment received, and survival rates.

RESULTS

Among the 202 patients diagnosed, 134 were males, and 68 were females. Tumor histology testing revealed that 168 patients had adenocarcinoma, 24 patients had squamous carcinoma, 5 patients had small cell carcinoma, and 5 patients were poorly differentiated carcinoma. Among the patients of adenocarcinoma, complete response, partial response (PR), stable disease, and progressive disease (PD) were seen in 0.6%, 52%, 17%, and 23.2% of the patients respectively. The median progression-free survival (PFS) for first-line treatment was 6.5 months; the highest PFS was seen with nab-paclitaxel/platinum combination. The mean overall survival was 11.7 months and the highest OS of 12.3 months with gefitinib therapy. In the squamous subset of patients, PR was observed in fourteen patients, of which five patients were treated with nab-paclitaxel/platinum. The mean overall survival of 10.5 months and mean PFS was 6.2 months with the highest PFS of 6.8 months were seen with weekly nab-paclitaxel. Among the small cell lung cancer patients, nine were treated with etoposide/platinum regimen with a compliance of 6 cycles. Three patients had a PR, and one had a PD on etoposide/platinum regimen. The mean overall survival in these patients was 4.6 months.

Comparative virulence of strains of entomopathogenic nematodes for management of eggplant Grey Weevil, Myllocerus subfasciatus Guerin (Coleoptera: Curculionidae)

The Grey Weevil, Myllocerus subfasciatus Guerin, is an important emerging pest of quarantine significance in Solanaceae crops including the eggplant, Solanum melongena. Entomopathogenic nematodes (EPNs) have been shown to be a potential source of safe and effective control of M. subfasciatus. In this study, we determined the virulence of seven strains of EPNs (Nematoda: Rhabditida) viz. Heterorhabditis bacteriophora NBAIIHb105, H. indica NBAIIHi101, H. indica NBAIIHiMah, Steinernema abbasi NBAIISa01, Steinernema abbasi NBAIISa04, S. carpocapsae NBAIISc04 and S. glaseri NBAIISg01, with different foraging behaviour, against larvae of eggplant grey weevil, M. subfasciatus (Coleoptera: Curculionidae), and their suitability in five representative soils from the eggplant grown areas under laboratory conditions. All seven nematode strains caused >80% mortality of M. subfasciatus larvae at 40 IJs/cm2. LC90 values ranged between 21.18 and 46.41 IJs/cm2 at 96 h post-application, which corresponded to field concentrations between 2.1-4.6×109 IJs/ha. H. indica NBAIIHi101, S. glaseri NBAIISg01, S. abbasi NBAIISa01 and S. carpocapsae NBAIISc04 recorded higher grub mortality, compared to H. indica NBAIIHiMah, H. bacteriophora NBAIIHb05 and S. abbasi NBAIISa04 indicating existence of inter- and intra-specific variation in virulence. Response Surface Modelling (RSM) optimized LC and LT values for maximised larval mortality. RSM predicted a concentration of 58.05-62.54 IJs/cm2 of these EPN (corresponding to a field dose of 5.8-6.2×109 IJs/ha) required for effecting 97.10-99.67% grub mortality, at 90-97 h of exposure. EPN strains performed better in terms of larval mortality in loamy sand, alluvial, mountain soil, red laterite compared to black cotton soils. Efficacy of EPN was positively correlated with the content of sand, and negatively with the clay content. It is possibly the first report that established the potential of local strains of EPNs with different foraging ability and their dosages for suppression of subterranean root feeding larvae of M. subfasciatus in five broad soil types of eggplant grown areas. Validation of this baseline data in real-time eggplant crop situations may help in evolving EPN-based viable management schedules for M. subfasciatus.

Structural studies on oxalate decarboxylase from Photorhabdus luminescens

As a part of exploration of novel bacterial genes coding for insecticidal proteins, we have initiated structural and functional studies on oxalate decarboxylase from Photorhabdus luminescens, a symbiotic bacteria inhabiting guts of nematodes that parasitize insects. Oxalate decarboxylases (OXDC) are enzymes that catalyze the conversion of oxalate to formate and carbondioxide (CO2) in the presence of manganese and dioxygen. Structures of OXDC in complex with ethylene glycol (EDO), EDO/formate (FMT) and FMT/CO2 were determined at resolutions of 1.97Å, 2.36Å and 2.5Å, respectively. The asymmetric unit of these crystals contained a trimeric molecule. A protomer of the enzyme consists of two β-barrel domains belonging to the cupin family of proteins. All the three ligand bound structures of OXDC resemble the closed form of OXDC from B. subtilis reported earlier. Comparison of these structures with the open and closed forms of B. subtilis OXDC indicated that the conformation of Glu166 (corresponding to Glu162 of B. subtilis) in cupin domain I but not in domain II is in a conformation suitable to function as the catalytic base/acid and hence only domain I may be catalytically active. It is observed that the hydrogen bonding interaction between Arg95 and Thr169 of cupin domain I is essential for the positioning of Glu166 for catalysis. A corresponding threonine residue is absent in cupin domain II. An analysis of the similarities and differences between OXDC structures from P. luminescens and other reported bacterial OXDC structures and oxalate oxidase from Hordeum vulgare has been carried out with the view of understanding substrate and functional specificities of these enzymes. The structure provides the molecular framework required to investigate the mode of action of the enzyme, which may be a suitable candidate for developing P. luminescens as a bio-insecticide against plant pests.

Determination of theanine in commercial tea by liquid chromatography with fluorescence and diode array ultraviolet detection

Two liquid chromatographic methods that involve precolumn derivatization with o-phthaladehyde (OPA) and phenylisothiocyanate (PITC) with fluorescence and diode array UV detection for the determination of theanine have been developed. The chromatographic separations were achieved by reverse-phase high-performance liquid chromatography using octadecyl columns and gradient elution. The methods were applied to evaluate the theanine content of commercial tea leaves. The coefficient of variation of the peak area repeatability for within day (n = 8) and between day (n = 8 over 10 days) was lower than 3% for both of the methods. The estimated limit of detection (LOD) and limit of quantitation (LOQ) for the OPA method was 0.12 and 0.35 microg theanine, respectively. The PITC method was 500-fold more sensitive with LOD and LOQ values of 0.25 and 0.75 ng, respectively. The theanine content of the commercial tea samples varied from 2-5 mg/g leaf. The overall % recoveries for these methods ranged from 93-99.3. The sensitivity and simplicity of the method render them suitable for use in quality control laboratories.