Thermal stress and physiological strain in the glass bangle industry

A preliminary survey of the few units of the small-scale glass bangle industry in Firozabad, Agra District, Uttar Pradesh, indicated that the workers were exposed to severe degrees of heat stress during various operations in the manufacturing processes. A more detailed study in eight glass bangle units was therefore undertaken to make quantitative estimates of heat stress on exposed workers in the summer season. The thermal data collected confirmed that the heat stress on the workers was severe but measurement of certain physiological indicators revealed relatively low levels of strain amongst the exposed workers. The findings could be attributable to high degrees of acclimatization, but further observations in the field supplemented by studies on simulated exposures of volunteers in a climatic chamber seem to be warranted.     

Incorporation of beta-fluoroasparagine into peptides prevents N-linked glycosylation. In vitro studies with synthetic fluoropeptides

Previously, we reported that incorporation of threo-beta-fluoroasparagine into cellular protein inhibits N-linked glycosylation. We now show that short synthetic peptides which contain N-acetyl-threo-beta-fluoroasparagine fail to undergo glycosylation in a cell-free system except at extremely high substrate concentrations. An N-benzoyl-threo-beta-fluoroasparagine-containing peptide has a 100-fold lower Vmax/Km than the analogous N-benzoyl-asparagine-containing peptide. Substitution of a fluorine for a hydrogen on the beta-carbon of asparagine weakens the ability of the peptide to bind the oligosaccharyltransferase. A 100-fold excess of acetyl-threo-beta-fluoroasparaginyl-leucyl-threonine methylamide over acetyl-asparaginyl-leucyl-threonine methylamide inhibited glycosylation of the latter peptide by less than 10%. Both threo-beta-fluoroasparagine and erythro-beta-fluoroasparagine-containing peptides are glycosylated at the same rate. Glycofluoropeptides generated from beta-fluoroasparagine-containing peptides were N-glycosylated. These cell-free studies with synthetic fluoropeptides suggest that incorporation of beta-fluoroasparagine into cellular protein inhibits N-linked glycosylation by rendering protein substrates ineffective for glycosylation. In the course of this work, we also demonstrate that the N-linked glycosylating enzyme acts only on L-asparagine-containing peptides and not on D-asparagine peptides.     

Agrobacterium-mediated transformation of promising oil-bearing marine algae Parachlorella kessleri

Parachlorella kessleri is a unicellular alga which grows in fresh as well as marine water and is commercially important as biomass/lipid feedstock and in bioremediation. The present study describes the successful transformation of marine P. kessleri with the help of Agrobacterium tumefaciens. Transformed marine P. kessleri was able to tolerate more than 10 mg l^?1 hygromycin concentration. Co-cultivation conditions were modulated to allow the simultaneous growth of both marine P. kessleri and A. tumefaciens. For co-cultivation, P. kessleri was shifted from Walne’s to tris acetate phosphate medium to reduce the antibiotic requirement during selection. In the present study, the transfer of T-DNA was successful without using acetosyringone. Biochemical and genetic analyses were performed for expression of transgenes by GUS assay and PCR in transformants. Establishment of this protocol would be useful in further genetic modification of oil-bearing Parachlorella species.     

Enhanced detection of human immunodeficiency virus type 1-specific T-cell responses to highly variable regions by using peptides based on autologous virus sequences

The antigenic diversity of human immunodeficiency virus type 1 (HIV-1) represents a significant challenge for vaccine design as well as the comprehensive assessment of HIV-1-specific immune responses in infected persons. In this study we assessed the impact of antigen variability on the characterization of HIV-1-specific T-cell responses by using an HIV-1 database to determine the sequence variability at each position in all expressed HIV-1 proteins and a comprehensive data set of CD8 T-cell responses to a reference strain of HIV-1 in infected persons. Gamma interferon Elispot analysis of HIV-1 clade B-specific T-cell responses to 504 overlapping peptides spanning the entire expressed HIV-1 genome derived from 57 infected subjects demonstrated that the average amino acid variability within a peptide (entropy) was inversely correlated to the measured frequency at which the peptide was recognized (P = 6 x 10(-7)). Subsequent studies in six persons to assess T-cell responses against p24 Gag, Tat, and Vpr peptides based on autologous virus sequences demonstrated that 29% (12 of 42) of targeted peptides were only detected with peptides representing the autologous virus strain compared to the HIV-1 clade B consensus sequence. The use of autologous peptides also allowed the detection of significantly stronger HIV-1-specific T-cell responses in the more variable regulatory and accessory HIV-1 proteins Tat and Vpr (P = 0.007). Taken together, these data indicate that accurate assessment of T-cell responses directed against the more variable regulatory and accessory HIV-1 proteins requires reagents based on autologous virus sequences. They also demonstrate that CD8 T-cell responses to the variable HIV-1 proteins are more common than previously reported.     

Comprehensive epitope analysis of human immunodeficiency virus type 1 (HIV-1)-specific T-cell responses directed against the entire expressed HIV-1 genome demonstrate broadly directed responses,but no correlation to viral load

Cellular immune responses play a critical role in the control of human immunodeficiency virus type 1 (HIV-1); however, the breadth of these responses at the single-epitope level has not been comprehensively assessed. We therefore screened peripheral blood mononuclear cells (PBMC) from 57 individuals at different stages of HIV-1 infection for virus-specific T-cell responses using a matrix of 504 overlapping peptides spanning all expressed HIV-1 proteins in a gamma interferon-enzyme-linked immunospot (Elispot) assay. HIV-1-specific T-cell responses were detectable in all study subjects, with a median of 14 individual epitopic regions targeted per person (range, 2 to 42), and all 14 HIV-1 protein subunits were recognized. HIV-1 p24-Gag and Nef contained the highest epitope density and were also the most frequently recognized HIV-1 proteins. The total magnitude of the HIV-1-specific response ranged from 280 to 25,860 spot-forming cells (SFC)/10(6) PBMC (median, 4,245) among all study participants. However, the number of epitopic regions targeted, the protein subunits recognized, and the total magnitude of HIV-1-specific responses varied significantly among the tested individuals, with the strongest and broadest responses detectable in individuals with untreated chronic HIV-1 infection. Neither the breadth nor the magnitude of the total HIV-1-specific CD8+-T-cell responses correlated with plasma viral load. We conclude that a peptide matrix-based Elispot assay allows for rapid, sensitive, specific, and efficient assessment of cellular immune responses directed against the entire expressed HIV-1 genome. These data also suggest that the impact of T-cell responses on control of viral replication cannot be explained by the mere quantification of the magnitude and breadth of the CD8+-T-cell response, even if a comprehensive pan-genome screening approach is applied.     

Novel drug designing approach for dual inhibitors as anti-inflammatory agents: implication of pyridine template

Compounds incorporating thiophene moiety, a pi excess five membered heterocycle, have attracted a great deal of research interest, owing to the therapeutic utility of the template as useful drug molecular scaffolding. We report the synthesis and pharmacological evaluation of thiophenes substituted with 4-methanesulfonyl benzoyl moiety at the fifth position of the ring, as possible anti-inflammatory lead candidates. The aryl sulfonyl methyl thiophene analogs AP29, AP82, and AP37, when screened for anti-inflammatory activity in carrageenin induced rat paw edema, an acute in vivo model, exhibited moderate to good activity at a dose level of 100 mg/kg body weight P.o compared to Ibuprofen. In a five day formalin induced rat paw edema, a chronic in vivo anti-inflammatory model, candidates AP29, AP82, and AP37 inhibited the disease progression by 53%, 34%, and 65%, respectively on the fifth day, at a dose level of 100 mg/kg body weight P.o compared to Rofecoxib, Ibuprofen, and Dexamethasone at therapeutic doses which gave a protection of 53.8%, 81.5%, and 81.5%, respectively. The replacement of the 4-methanesulfonyl benzoyl moiety in AP82 with the pyridine template, 3,5-dimethyl-4-methoxy-2-pyridyl function, gave rise to AP84, which was less active in the acute model, but gave 54% and 75% protection both during the first day and fifth day, respectively, in the chronic model. A dual mechanism of action is proposed for AP84, a non-steroidal drug which has exhibited remarkable activity when compared to the steroid dexamethasone. These results open up new avenues in designing novel anti-inflammatory drugs as dual inhibitors with the incorporation of a pyridine template as part of the pharmacophore.     

Use of tree seedlings for the phytoremediation of a municipal effluent used in dry areas of north-western India: Plant growth and nutrient uptake

Impacts of municipal effluent (ME) irrigation on soil physicochemical properties and its remediation by tree species were assessed with a view to utilize this resource in growing woodlot, controlling land degradation and improving environmental quality in suburban areas. Acacia nilotica L. (babool), Dalbergia sissoo L. (sissoo) and Eucalyptus camaldulensis seedlings planted in July 1998 were irrigated with ME at ½ PET (T₂), 1 PET (T₃), 2 PET (T₄), and with canal water at 1 PET (T₅). The control was soil without seedlings irrigated with ME at 1 PET (T₁). Application of ME increased minerals concentration from T₂ to T₄ in both soil and seedling in June 1999 and 2000. The increase in soil pH, EC, SOC was by <2.00-fold and availability of potassium (K), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) by >2-fold, NH₄–N by 10.44-fold and PO₄–P by 6.57-fold in T₄ than those in T₅ treatment in 2000. Available NH₄–N, PO₄–P, Mg and K were higher in 0–15 cm soil layer but continued irrigation and low soil carbon influenced leaching of NO₃–N, Na, Cu, Fe, Mn and Zn resulting their higher concentrations in 60–90 cm soil layer (P < 0.01). Lower soil nutrients in T₃ than in T₁ suggested soil amelioration by the planted seedlings and because of lowest concentration of most of the nutrients E. camaldlensis showed highest soil amelioration capacity. But nutrient utilization efficiency was highest in A. nilotica for K, Ca, Mg, Na, Fe, Cu and Zn, D. sissoo for N and P, and E. camaldulensis for Mn. Thus, planting tree seedlings, particularly E. camaldulensis, under ecological amelioration could in this way help in controlling land degradation and enhancing biomass and aesthetic benefits, although long-term application of effluent would lead to mineral/salt accumulation in soil and plants.