Isolation of the opioid peptide Leu-Val-Val-hemorphin-7 from bronchoalveolar lavage fluid of a patient with non-small cell lung cancer

The decapeptide Leu-Val-Val-Tyr-Pro-Trp-Thr-Gln-Arg-Phe was isolated in high yield (1.5 nmol/ml) from bronchoalveolar lavage (BAL) fluid from a patient with an adenocarcinoma of the lung. This peptide, termed LVV-hemorphin-7 represents residues 32-41 of the beta-chain of hemoglobin and has been shown to be an endogenous ligand for opioid receptors. The N-terminal flanking peptide of LVV-hemorphin-7 [residues (1-31) of hemoglobin beta-chain] was also isolated in high yield. Neither peptide was detected in BAL fluid from the tumor-free lung of the same patient or from patients with non-neoplastic inflammatory lung disease. LVV-hemorphin-7 was not identified in BAL fluid from seven additional patients with non-small cell lung cancer, indicating that the formation of the peptide is unlikely to be of any diagnostic significance. However, the ability of LVV-hemorphin-7 to inhibit angiotensin-converting enzyme suggests that its formation may be of pathophysiological significance in the regulation of tumor blood flow in certain patients.     

Lactic acid bacteria in Hamei and Marcha of North East India

Hamei and Marcha are mixed dough inocula used as starters for preparation of various indigenous alcoholic beverages in Manipur and Sikkim in India, respectively. These starters are traditionally prepared from rice with wild herbs and spices. Samples of Hamei and Marcha, collected from Manipur and Sikkim, respectively, were analysed for lactic acid bacterial composition. The population of lactic acid bacteria (LAB) was 6.9 and 7.1 Log cfu/g in Hamei and Marcha, respectively. On the basis of phenotypic and genotypic characters, LAB strains isolated from Hamei and Marcha were identified as Pediococcus pentosaceus, Lactobacillus plantarum and Lactobacillus brevis. Technological properties of LAB such as antimicrobial properties, effect on acidification, ability to produce biogenic amines and ethanol, degree of hydrophobicity and enzymatic activities were also performed. Pediococcus pentosaceus HS: B1, isolated from Hamei, was found to produce bacteriocin. None of the strains produced biogenic amines. LAB strains showed a strong acidifying ability and they also produced a wide spectrum of enzymes.     

N6-Cycloalkyl-2-substituted adenosine derivatives as selective, high affinity adenosine A1 receptor agonists

A series of new selective, high affinity A(1)-AdoR agonists is reported. Compound 23 that incorporated a carboxylic acid functionality in the 4-position of the pyrazole ring displayed K(iL) value of 1 nM for the A(1)-AdoR and >5000-fold selectivity over the A(3) and A(2A)-AdoRs. In addition, compound 19 that incorporated a carboxamide functionality in the 4-position of the pyrazole ring displayed subnanomolar affinity for the A(1)-AdoR (K(iL)=0.6 nM) and >600-fold selectivity over the A(3) and A(2A)-AdoRs.     

Bacteriophage P22 tail accessory factor GP26 is a long triple-stranded coiled-coil

P22 is a well characterized tailed bacteriophage that infects Salmonella enterica serovar Typhimurium. It is characterized by a "short" tail, which is formed by five proteins: the dodecameric portal protein (gp1), three tail accessory factors (gp4, gp10, gp26), and six trimeric copies of the tail-spike protein (gp9). We have isolated the gene encoding tail accessory factor gp26, which is responsible for stabilization of viral DNA within the mature phage, and using a variety of biochemical and biophysical techniques we show that gp26 is very likely a triple stranded coiled-coil protein. Electron microscopic examination of purified gp26 indicates that the protein adopts a rod-like structure approximately 210 angstroms in length. This trimeric rod displays an exceedingly high intrinsic thermostability (T(m) approximately 85 degrees C), which suggests a potentially important structural role within the phage tail apparatus. We propose that gp26 forms the thin needle-like fiber emanating from the base of the P22 neck that has been observed by electron microscopy of negatively stained P22 virions. By analogy with viral trimeric coiled-coil class I membrane fusion proteins, gp26 may represent the membrane-penetrating device used by the phage to pierce the host outer membrane.     

Superoxide formation and interaction with nitric oxide modulate systemic arterial pressure and renal function in salt-depleted dogs

To determine the role of superoxide (O(2)(-)) formation in the kidney during alterations in the renin-angiotensin system, we evaluated responses to the intra-arterial infusion of an O(2)(-) - scavenging agent, tempol, in the denervated kidney of anesthetized salt-depleted (SD, n=6) dogs and salt-replete (SR, n=6) dogs. As expected, basal plasma renin activity was higher in SD than in SR dogs (8.4 +/- 1.0 vs. 2.3 +/- 0.6 ng angiotensin 1/ml/hr). Interestingly, the basal level of urinary F(2)-isoprostanes excretion (marker for endogenous O(2)(-) activity) relative to creatinine (Cr) excretion was also significantly higher in SD compared to SR dogs (9.1 +/- 2.8 vs. 1.6 +/- 0.4 ng F(2)-isoprostanes/mg of Cr). There was a significant increase in renal blood flow (4.3 +/- 0.5 to 4.9 +/- 0.6 ml/min/g) and decreases in renal vascular resistance (38.2 +/- 5.8 to 33.2 +/- 4.7 mm Hg/ml/min/g) and mean systemic arterial pressure (148 +/- 6 to 112 +/- 10 mm Hg) in SD dogs but not in SR dogs during infusion of tempol at 1 mg/kg/min for 30 mins. Glomerular filtration rate and urinary sodium excretion (U(Na)V) did not change significantly during tempol infusion in both groups of dogs. Administration of the nitric oxide synthase inhibitor nitro-L-arginine (50 mug/kg/min) during tempol infusion caused a reduction in U(Na)V in SR dogs (47% +/- 12%) but did not cause a decrease in SD dogs. These data show that low salt intake enhances O(2)(-) activity that influences renal and systemic hemodynamics and thus may contribute to the regulation of arterial pressure in the salt-restricted state.     

Growth kinetics of microalgae in microfluidic static droplet arrays

We investigated growth kinetics of microalgae, Chlorella vulgaris, in immobilized arrays of nanoliter‐scale microfluidic drops. These static drop arrays enabled simultaneous monitoring of growth of single as well as multiple cells encapsulated in individual droplets. To monitor the growth, individual drop volumes were kept nearly intact for more than a month by controlling the permeation of water in and out of the microfluidic device. The kinetic growth parameters were quantified by counting the increase in the number of cells in each drop over time. In addition to determining the kinetic parameters, the cell‐size distribution of the microalgae was correlated with different stages of the growth. The single‐cell growth kinetics of C. vulgaris showed significant heterogeneity. The specific growth rate ranged from 0.55 to 1.52 day^?1 for different single cells grown in the same microfluidic device. In comparison, the specific growth rate in bulk‐scale experiment was 1.12 day^?1. It was found that the average cell size changes significantly at different stages of the cell growth. The mean cell‐size increased from 5.99 ± 1.08 to 7.33 ± 1.3 µm from exponential to stationary growth phase. In particular, when multiple cells are grown in individual drops, we find that in the stationary growth phase, the cell size increases with the age of cell suggesting enhanced accumulation of fatty acids in older cells. Biotechnol. Bioeng. 2012; 109: 2987–2996. © 2012 Wiley Periodicals, Inc.     

Urbanization and green space dynamics in Greater Dhaka, Bangladesh

Green space is particularly indispensable for proper functioning of the ecosystem in an urban environment. This study was an attempt to dynamically map and monitor green spaces in Greater Dhaka of Bangladesh. Both primary and secondary data were acquired to document the spatial–temporal dynamics of green spaces in the study area. Using a supervised classification algorithm, multi-temporal land use/cover data were extracted from a set of satellite images. A number of spatial metrics were employed to understand the landscape condition in a multi-temporal manner. In addition, 50 key informants along with focus group discussion and observation techniques were used to document existing management aspects of green spaces and their conservation policies. The analysis revealed that green spaces in Greater Dhaka are rapidly disappearing over the course of time even though they provide a number of natural, economic and social benefits. The disappearance of green spaces was primarily attributed to a rapid increase in the urban population, mainly driven by rural–urban migration. As a result, the landscape became highly fragmented and less connected. A substantial reduction of green patches is also leading to deterioration of the ecological condition of the landscape. The drastic reduction of green spaces in Greater Dhaka has been attributed to a lack of policy, low political motivation, and poor management. In order to ensure sustainability of green spaces and proper functioning of the city’s ecosystem, there is an urgent need for strategic green space planning.     

Feasibility and Effectiveness of Provider Initiated HIV Testing and Counseling of TB Suspects in Vizianagaram District, South India

Background

Though internationally recommended, provider initiated HIV testing and counseling (PITC) of persons suspected of tuberculosis (TB) is not a policy in India; HIV seroprevalence among TB suspects has never been reported. The current policy of PITC for diagnosed TB cases may limit opportunities of early HIV diagnosis and treatment. We determined HIV seroprevalence among persons suspected of TB and assessed feasibility and effectiveness of PITC implementation at this earlier stage in the TB diagnostic pathway.

Methods

All adults examined for diagnostic sputum microscopy (TB suspects) in Vizianagaram district (population 2.5 million), in November-December 2010, were offered voluntary HIV counseling and testing (VCT) and assessed for TB diagnosis.

Results

Of 2918 eligible TB suspects, 2465(85%) consented to VCT. Among these, 246(10%) were HIV-positive. Of the 246, 84(34%) were newly diagnosed as HIV (HIV status not known previously). To detect a new case of HIV infection, the number needed to screen (NNS) was 26 among ‘TB suspects’, comparable to that among ‘TB patients’. Among suspects aged 25–54 years, not diagnosed as TB, the NNS was 17.

Conclusion

The seroprevalence of HIV among ‘TB suspects’ was as high as that among ‘TB patients’. Implementation of PITC among TB suspects was feasible and effective, detecting a large number of new HIV cases with minimal additional workload on staff of HIV testing centre. HIV testing of TB suspects aged 25–54 years demonstrated higher yield for a given effort, and should be considered by policy makers at least in settings with high HIV prevalence.