T Cell Activation Inhibitors Reduce CD8+ T Cell and Pro-Inflammatory Macrophage Accumulation in Adipose Tissue of Obese Mice

Adipose tissue inflammation and specifically, pro-inflammatory macrophages are believed to contribute to insulin resistance (IR) in obesity in humans and animal models. Recent studies have invoked T cells in the recruitment of pro-inflammatory macrophages and the development of IR. To test the role of the T cell response in adipose tissue of mice fed an obesogenic diet, we used two agents (CTLA-4 Ig and anti-CD40L antibody) that block co-stimulation, which is essential for full T cell activation. C57BL/6 mice were fed an obesogenic diet for 16 weeks, and concomitantly either treated with CTLA-4 Ig, anti-CD40L antibody or an IgG control (300 µg/week). The treatments altered the immune cell composition of adipose tissue in obese mice. Treated mice demonstrated a marked reduction in pro-inflammatory adipose tissue macrophages and activated CD8+ T cells. Mice treated with anti-CD40L exhibited reduced weight gain, which was accompanied by a trend toward improved IR. CTLA-4 Ig treatment, however, was not associated with improved IR. These data suggest that the presence of pro-inflammatory T cells and macrophages can be altered with co-stimulatory inhibitors, but may not be a significant contributor to the whole body IR phenotype.     

Chemical Modification of Specific Active Site Amino Acid Residues of Enterobacter aerogenes Glycerol Dehydrogenase

Enterobacter aerogenes glycerol dehydrogenase (GlDH EC 1.1.1.6), a tetrameric NAD + specific enzyme catalysing the interconversion of glycerol and dihydroxyacetone, was inactivated on reaction with pyridoxal 5′-phosphate (PLP) and o -phthalaldehyde (OPA). Fluorescence spectra of PLP-modified, sodium borohydride-reduced GlDH indicated the specific modification of ? -amino groups of lysine residues. The extent of inhibition was concentration and time dependent. NAD + and NADH provided complete protection against enzyme inactivation by PLP, indicating the reactive lysine is at or near the coenzyme binding site. Modification of GlDH by the bifunctional reagent OPA, which reacts specifically with proximal ? -NH 2 group of lysines and -SH group of cysteines to form thioisoindole derivatives, inactivated the enzyme. Molecular weight determinations of the modified enzyme indicated the formation of intramolecular thioisoindole formation. Glycerol partially protected the enzyme against OPA inactivation, whereas NAD + was ineffective. These results show that the lysine involved in the OPA reaction is different from the PLP-reactive lysine, which is at or near the coenzyme binding site. DTNB titration showed the presence of only a single cysteine residue per monomer of GlDH. This could be participating with a proximal lysine residue to form a thioisoindole derivative observed as a result of OPA modification.     

Patterns of understory diversity in mixed coniferous forests of southern California impacted by air pollution

The forests of the San Bernardino Mountains have been subject to ozone and nitrogen (N) deposition for some 60 years. Much work has been done to assess the impacts of these pollutants on trees, but little is known about how the diverse understory flora has fared. Understory vegetation has declined in diversity in response to elevated N in the eastern U.S. and Europe. Six sites along an ozone and N deposition gradient that had been part of a long-term study on response of plants to air pollution beginning in 1973 were resampled in 2003. Historic ozone data and leaf injury scores confirmed the gradient. Present-day ozone levels were almost half of these, and recent atmospheric N pollution concentrations confirmed the continued air pollution gradient. Both total and extractable soil N were higher in sites on the western end of the gradient closer to the urban source of pollution, pH was lower, and soil carbon (C) and litter were higher. The gradient also had decreasing precipitation and increasing elevation from west to east. However, the dominant tree species were the same across the gradient. Tree basal area increased during the 30-year interval in five of the sites. The two westernmost sites had 30-45% cover divided equally between native and exotic understory herbaceous species, while the other sites had only 3-13% cover dominated by native species. The high production is likely related to higher precipitation at the western sites as well as elevated N. The species richness was in the range of 24 to 30 in four of the sites, but one site of intermediate N deposition had 42 species, while the easternmost, least polluted site had 57 species. These were primarily native species, as no site had more than one to three exotic species. In three of six sites, 20-40% of species were lost between 1973 and 2003, including the two westernmost sites. Two sites with intermediate pollution had little change in total species number over 30 years, and the easternmost site had more species in 2003. The easternmost site is also the driest and has the most sunlight filtering to the forest floor, possibly accounting for the higher species richness. The confounding effects of the precipitation gradient and possibly local disturbances do not show a simple correlation of air pollution with patterns of native and invasive species cover and richness. Nevertheless, the decline of native species and dominance by exotic species in the two westernmost polluted sites is cause for concern that air pollution is affecting the understory vegetation adversely.     

Study of catheptic and acid phosphatase activities during development and metamorphosis ofDrosophila melanogaster

Summary Developmental stages ofDrosophila melanogaster cultured at 22 ± 1° C were collected and tested for catheptic activity and acid phosphatase activity.It was found that catheptic activity was absent in the egg as well as in the first and second larval instars. The activity first appears in the third instar larva and reaches its peak 24 to 48 hr after puparium formation. It then decreases, at first gradually and at pupal stage 9 (120 to 144 hr after puparium formation) abruptly, reaching zero level just before the emergence of the imago.The pattern of acid phosphatase activity in different developmental stages was found to be broadly similar to that of catheptic activity in the larval and pupal stages. However, the acid phosphatase activity was found to be exceptionally high in the egg in contrast to the catheptic activity.The authors are grateful to Prof. Dr. R. Weber, Zoological Institute of the University of Bern, for constructive criticism of this paper.     

The growth rates of the estuarine mollusc Musculista arcuatula Yamamoto and Habe (Bivalvia: Mytilidae)

The pattern of growth of the total population of Musculista arcuatula over a period of thirteen months was built up plotting length-percentage frequency histograms each month. From the shifting of the modes it was noticed that the increase in size from November to December was 2 mm, the growth during December to January 3 mm. In February the growth was nil. In March the size increasing by 6 mm and in April by 1 mm, when mortality of the largest size groups started to get completed in May. In June a conspicuous mode appeared at 9 mm, grew 1 mm in July, 2 mm in August and 3 mm in September. Growth remained stationary in October and November. The rate of increase in length was found to follow exponential law. The growth rate of this bivalve goes on increasing at a steady pace, the rate being 1.086 mm per month. The mean size of the females was found to be significantly larger than that of the males. The proportion of the males in the size group 3 mm to 10 mm was found to be significantly larger than in the entire population. But in the larger size groups there was no difference in the number of males and females and the proportion was almost 1:1. Throughout the year only one age class was recognizable in the natural population. There appears to be an excessive post reproductive mortality of adults rendering the population during most of the year of a single age class recruited through the various months of spawning. The maximum longevity was found to be at the most 18 months.     

Plant regeneration from leaf discs of peanut and pigeonpea: Influence of benzyladenine,indoleacetic acid and indoleacetic acid-amino acid conjugates

The influence of indoleacetic acid (IAA) and some IAA-amino acid conjugates in combination with benzyladenine (BA) on in vitro shoot regeneration from leaf discs of peanut and pigeonpea was investigated. The frequency of shoot regeneration and average number of shoot buds produced was dependent on the type of auxin present in the medium. Highest frequency of plant regeneration in peanut was induced by BA in combination with IAA or IAA-l-alanine, while in pigeonpea BA in combination with IAA or IAA-l-aspartic acid produced best results. Four hundred plants of peanut and 25 plants of pigeonpea were transplanted to soil.Abbreviations BA benzyladenine - IAA indoleacetic acid - IAA l-alanine-indole acetyl-l-alanine - IAA aspartic acid-indole acetyl-l-aspartic acid - IAA glycine-indole acetyl-l-glycine - IAA phenylalanine-indole-acetyl-l-phenyl-alanine     

New biological activity against phospholipase A2 by Turmerin, a protein from Curcuma longa L

Turmerin is a protein from Turmeric (Curcuma longa L.) with a relative molecular mass of 14 kDa. The protein inhibits the enzymatic activity and neutralizes the pharmacological properties, such as cytotoxicity, oedema and myotoxicity of multitoxic phospholipase A2 (NV-PLA2) of cobra (Naja naja) venom at a 1:2.5 molar ratio of NV-PLA2:Turmerin. A Lineweaver-Burk plot indicates that Turmerin follows a linear mixed type of inhibition.     

Mineralization of 2-aminobenzenesulfonate by a bacterial consortium

A variety of environmental inocula were tested for the development of 2-aminobenzenesulfonate (2-ABS, Orthanilic acid) degrading bacterial enrichment. A bacterial consortium (BC), which could utilize 2-ABS as the sole carbon and energy source, could only be developed from the sludge derived from a wastewater treatment unit of a large chemical industry manufacturing nitro and aminoaromatics. BC consisted of two bacterial strains. Based on 16S rDNA sequence analysis, these strains were identified to be belonging to the genus, Acinetobacter and Flavobacterium. The consortium could degrade 1,000 mg l⁻¹ 2-ABS within 40 h. Evidence for the extensive mineralization of 2-ABS, during the growth of BC, was derived from U.V-spectral and total organic carbon analysis. BC was highly specific for 2-ABS, as other benzene sulfonates tested in this study, including other ABS isomers, were not utilized as growth substrates. 2-ABS removal pattern in the presence of glucose was significantly influenced by acclimation characteristics of the culture. Consortium adapted to 2-ABS/glucose demonstrated the concomitant removal of both substrates, whereas glucose exerted catabolic repression on 2-ABS removal with glucose adapted culture. Presence of chloramphenicol inhibited 2-ABS degradation by cells, pregrown on succinate, indicating that the 2-ABS degrading enzymes are inducible in nature. Thus the presence of 2-ABS is essential for maintaining the high degradation potential. This enrichment culture can find an application in the treatment of 2-ABS containing wastewaters.