Respiratory findings in art students

Art students are exposed to many noxious agents during their training. We studied respiratory findings in a cohort of the 117 art students in order to investigate the potential effects of these toxic agents in the art student's environment. A group of 88 medical students matched for age, sex and smoking, not exposed to known environmental pollutants were studied as controls for respiratory symptoms. Respiratory symptoms acute and chronic were evaluated by modifying the British Medical Research Council questionnaire. Lung function studies were performed with a spirometer (Jaeger, Germany) measuring maximum expiratory flow-volume (MEFV) curves. Significantly higher prevalences of most of the chronic respiratory symptoms were recorded in art compared to medical students (p < 0.05). Art students who were smokers had significantly higher prevalences of many of the chronic respiratory symptoms than nonsmoking art students. High prevalences of acute symptoms related to the study environment were recorded for art students. Odds ratios in male art students were significant for chronic cough, chronic phlegm and chronic bronchitis for the risk factors of exposure and smoking. Significantly decreased lung function was recorded for FVC, FEF50 and FEF25 in male and FVC, and FEF25 in female art students. Smokers and nonsmokers had similar reductions of lung function. Our data indicate that art students may be at risk of developing chronic respiratory symptoms and lung function changes as a result of their exposure and their smoking habits.     

Development of high oleic and low linoleic acid transgenics in a zero erucic acid Brassica juncea L. (Indian mustard) line by antisense suppression of the fad2 gene

A zero erucic acid (C22:1) line of Brassica juncea (VH486), adapted to the agronomic conditions of Northern India, has been modified for its fatty acid composition in the seed oil with antisense constructs using the sequence of fad2 gene of B. rapa. The full-length B. rapa fad2 cDNA sequence was determined by 5 and 3 RACE of a partial sequence available in the EST database. Construct pASfad2.1 contained 315 to 1251 bp and construct pASfad2.2 contained 1 to 1251 bp fragment of the fad2 gene, both in antisense orientation, driven by a truncated napin promoter. Analysis of the levels of linoleic acid (C18:2) in the BC1 seeds of single-copy transgenics showed that the construct pASfad2.2 gave better suppression of the fad2 gene as compared to the construct pASfad2.1. The BC1 transgenic seeds containing the pASfad2.2 construct segregated into two distinct classes of C18:2>20% (putative null homozygotes) and C18:2<20% (putative heterozygotes) in a 1:1 ratio, while the T1 seeds segregated into three classes, C18:2>20%, C18:2 between 12% and 20%) and C18:2<12% (putative homozygotes) in a 1:2:1 ratio. Putative homozygous T1 seeds (C18:2<12% analyzed by the half-seed method) of four of the transgenic lines were grown to establish T2 homozygous lines. These had ca. 73% C18:1 and 8 to 9% each of C18:2 and C18:3 (-linolenic acid) fractions in comparison to ca. 53% C18:1, 24% C18:2 and 16% C18:3 in the parental line VH486.     

Expression of LEKTI domains 6-9' in the baculovirus expression system: recombinant LEKTI domains 6-9' inhibit trypsin and subtilisin A

The precursor lympho-epithelial Kazal-type-related inhibitor (LEKTI), containing two Kazal-type and 13 nonKazal-type domains, is an efficient inhibitor of multiple serine proteinases, among them plasmin, subtilisin A, cathepsin G, elastase, and trypsin. To gain insight into the structure and function of some of these domains, a portion of the cDNA coding for LEKTI domains 6-9' was cloned and expressed in Sf9 cells using the baculovirus expression vector system (BEVS). Through a single purification step using a Co2+ column, 3-4 mg of purified recombinant LEKTI-domains 6-9' (rLEKTI6-9') with the predicted molecular mass of 34.6 kDa was obtained from the cell pellet of a 1-L culture. Unlike full-length LEKTI, rLEKTI6-9' inhibited trypsin and subtilisin A but not plasmin, cathepsin G, or elastase. The inhibition of trypsin and subtilisin A by rLEKTI6-9' occurred through a noncompetitive mechanism, with inhibitory constants (Ki) of 356 +/- 12 and 193 +/- 10 nM, respectively. On the basis of the Ki values, rLEKTI6-9' was determined to be a more potent trypsin inhibitor and a less potent subtilisin A inhibitor than the full-length LEKTI. In contrast to LEKTI domains 6-9', recombinant LEKTI domain 6 does not inhibit subtilisin A but competitively inhibited trypsin with a Ki of 200 +/- 10 nM. Taking LEKTI6-9' as an example, the BEVS should facilitate the structure-function analysis of naturally occurring processed LEKTI forms that have physiological relevance.     

<Emphasis Type="Italic">In vitro</Emphasis> plant regeneration via somatic embryogenesis through cell suspension cultures of horsegram [<Emphasis Type="Italic">Macrotyloma uniflorum</Emphasis> (Lam.) verdc.]

Summary In vitro regeneration of plants via somatic embryogenesis through cell suspension culture was achieved in horsegram. Embryogenic calluses were induced on leaf segments on solid Murashige and Skoog (MS) medium with 9.0 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Differentiation of somatic embryos occurred when the embryogenic calluses were transferred to liquid MS medium containing 2,4-D. Maximum frequency (33.2%) of somatic embryos was observed on MS medium supplemented with 7.9 μM 2,4-D. Cotyledonary-torpedo-shaped embryos were transferred to liquid MS medium without growth regulators for maturation and germination. About 5% of the embryos germinated into plants, which grew further on solid MS medium. The plants were hardened and established in soil. Effects of various auxins, cytokinins, carbohydrates, amino acids, and other additives on induction and germination of somatic embryos were also studied. A medium supplemented with 7.9 μM 2,4-D, 3.0% sucrose, 40 mg l⁻¹ L-glutamine, and 1.0 μM abscisic acid was effective to achieve a high frequency of somatic embryo induction, maturation, and further development.     

Photosynthetic flexibility in Pedilanthus tithymaloides poit,a CAM plant

The induction of CAM in Pedilanthus tithymaloides (Euphorbiaceae) under water-limited conditions was evaluated by following diurnal oscillations of CO2 fixation, titratable acidity and malic acid content in the leaf extracts. CAM induction was assessed by measuring the activities of phosphoenolpyruvate carboxylase (PEPC), NADH-malate dehydrogenase (MDH) and phosphoenolpyruvate caroxykinase (PEPCK) in the leaves as well. Drought resulted in large increases in the nocturnal acid accumulation and rates of CO2 uptake in the leaves of P. tithymaloides. The drought-induced CAM activity tended to be reversible after re-watering. Nevertheless, under well-watered conditions, plants of P. tithymaloides showed day time CO2 uptake patterns with less pronounced diurnal oscillations of organic acids. Our data indicate that although P. tithymaloides is a CAM plant, environmental variables like drought induce photosynthetic flexibility in this species. This type of plasticity in CAM and metabolic versatility in P. tithymaloides should be an adaptation for prolonged survival under natural adverse edaphic and microclimate situations.     

Functional analysis of plasma prophenoloxidase system in the marine mussel Perna viridis

The role of prophenoloxidase (proPO) system in recognition and phagocytosis of yeast cells by hemocytes was examined in vitro using whole plasma and proPO system isolated from the plasma of the marine mussel, Perna viridis. The proPO was isolated from the plasma by ammonium sulphate precipitation and gel filtration. The final proPO preparation was homogeneous in native PAGE, and could be activated by trypsin, α-chymotrypsin and pronase-E. Laminarin (a polymer of β-1, 3-glucan) and lipopolysaccharides (LPS) from diverse bacterial species effectively activated the isolated proPO, demonstrating the ability of this proenzyme to interact directly with microbial surface components. The susceptibility of proPO activation to inhibition by serine protease inhibitors such as soybean trypsin inhibitor (STI) or p-nitrophenyl-p′-guanidinobenzoate (p-NPGB), indicates that the isolated fraction may contain an integral serine protease domain in an inactive state. The presence of laminarin- or LPS-activated whole plasma of P. viridis facilitated adherence of yeast cells to hemocyte surface as well as eventually stimulated phagocytic uptake of the target cells by hemocytes, and no such hemocytic response was recorded with STI controls. This and other results strongly suggest that the intermediary factors generated during activation of plasma proPO system by non-self molecules play a key role in recognition and opsono-phagocytosis by hemocytes. However, the proPO system isolated from P. viridis plasma, after activation with microbial surface components, failed to show an opsonic effect.     

γ–aminobutyric acid promotes stem elongation in Stellaria longipes: The role of ethylene

The response of stems to GABA was biphasic in that lower concentrations of GABA (upto 500 µM) promoted stem elongation, but higher concentrations of GABA inhibited stem elongation. An optimal GABA concentration of 250 µM produced maximum stem elongation. The higher GABA concentrations also stimulated 1-aminocyclopropane-1-carboxylate (ACC) synthase (EC 4.4.1.14) mRNA accumulation and ethylene production. Results suggest that the inhibitory effect of higher GABA concentrations on stem elongation is partly mediated by ethylene.     

Dual‐Confined Flexible Sulfur Cathodes Encapsulated in Nitrogen‐Doped Double‐Shelled Hollow Carbon Spheres and Wrapped with Graphene for Li–S Batteries

Batteries with high energy and power densities along with long cycle life and acceptable safety at an affordable cost are critical for large‐scale applications such as electric vehicles and smart grids, but is challenging. Lithium–sulfur (Li‐S) batteries are attractive in this regard due to their high energy density and the abundance of sulfur, but several hurdles such as poor cycle life and inferior sulfur utilization need to be overcome for them to be commercially viable. Li–S cells with high capacity and long cycle life with a dual‐confined flexible cathode configuration by encapsulating sulfur in nitrogen‐doped double‐shelled hollow carbon spheres followed by graphene wrapping are presented here. Sulfur/polysulfides are effectively immobilized in the cathode through physical confinement by the hollow spheres with porous shells and graphene wrapping as well as chemical binding between heteronitrogen atoms and polysulfides. This rationally designed free‐standing nanostructured sulfur cathode provides a well‐built 3D carbon conductive network without requiring binders, enabling a high initial discharge capacity of 1360 mA h g^?1 at a current rate of C/5, excellent rate capability of 600 mA h g^?1 at 2 C rate, and sustainable cycling stability for 200 cycles with nearly 100% Coulombic efficiency, suggesting its great promise for advanced Li–S batteries.     

Lithium Polyacrylate (LiPAA) as an Advanced Binder and a Passivating Agent for High‐Voltage Li‐Ion Batteries

Intensive studies of an advanced energy material are reported and lithium polyacrylate (LiPAA) is proven to be a surprisingly unique, multifunctional binder for high‐voltage Li‐ion batteries. The absence of effective passivation at the interface of high‐voltage cathodes in Li‐ion batteries may negatively affect their electrochemical performance, due to detrimental phenomena such as electrolyte solution oxidation and dissolution of transition metal cations. A strategy is introduced to build a stable cathode–electrolyte solution interphase for LiNi_0.5Mn_1.5O₄ (LNMO) spinel high‐voltage cathodes during the electrode fabrication process by simply using LiPAA as the cathode binder. LiPAA is a superb binder due to unique adhesion, cohesion, and wetting properties. It forms a uniform thin passivating film on LNMO and conducting carbon particles in composite cathodes and also compensates Li‐ion loss in full Li‐ion batteries by acting as an extra Li source. It is shown that these positive roles of LiPAA lead to a significant improvement in the electrochemical performance (e.g., cycle life, cell impedance, and rate capability) of LNMO/graphite battery prototypes, compared with that obtained using traditional polyvinylidene fluoride (PVdF) binder for LNMO cathodes. In addition, replacing PVdF with LiPAA binder for LNMO cathodes offers better adhesion, lower cost, and clear environmental advantages.     

Clonal CD8+ T Cell Persistence and Variable Gene Usage Bias in a Human Transplanted Hand

Immune prophylaxis and treatment of transplanted tissue rejection act indiscriminately, risking serious infections and malignancies. Although animal data suggest that cellular immune responses causing rejection may be rather narrow and predictable based on genetic background, there are only limited data regarding the clonal breadth of anti-donor responses in humans after allogeneic organ transplantation. We evaluated the graft-infiltrating CD8⁺ T lymphocytes in skin punch biopsies of a transplanted hand over 178 days. Profiling of T cell receptor (TCR) variable gene usage and size distribution of the infiltrating cells revealed marked skewing of the TCR repertoire indicating oligoclonality, but relatively normal distributions in the blood. Although sampling limitation prevented complete assessment of the TCR repertoire, sequencing further identified 11 TCR clonal expansions that persisted through varying degrees of clinical rejection and immunosuppressive therapy. These 11 clones were limited to three TCR beta chain variable (BV) gene families. Overall, these data indicate significant oligoclonality and likely restricted BV gene usage of alloreactive CD8⁺ T lymphocytes, and suggest that changes in rejection status are more due to varying regulation of their activity or number rather than shifts in the clonal populations in the transplanted organ. Given that controlled animal models produce predictable BV usage in T lymphocytes mediating rejection, understanding the determinants of TCR gene usage associated with rejection in humans may have application in specifically targeted immunotherapy.