Role of acid proteases in brown adipose tissue atrophy caused by fasting in mice

The lysosomal proteolytic capacity of mouse brown adipose tissue (BAT) and its role during fasting were evaluated. The specific activities of acid phosphatase and cathepsins B, D, H, and L were measured in BAT of mice acclimated at 33, 21, and 4 degrees C and in BAT undergoing different rates of protein loss during a 24- to 48-h fast. The specific activities of lysosomal proteases in BAT did not vary with the acclimation status of the animals. Mice acclimated at 33 degrees C showed no significant atrophy of BAT after a fast. In mice kept at 21 degrees C, protein loss from BAT was observed after a fast without change in tissue DNA content. Protein loss from BAT was partially reduced by injection of the acidotropic agent chloroquine. Furthermore, tyrosine release from BAT during fasting was also reduced by injections of chloroquine or leupeptin, a thiol-protease inhibitor. Tyrosine release from BAT was maximum within 24 h and returned to prefast values by 36 h, suggesting rapid activation followed by inhibition of the tissue proteolytic activity. However, there was no change in acid protease specific activities, suggesting that these enzymes were not limiting for protein degradation. When cold-acclimated mice were fasted at 21 degrees C, BAT protein loss was markedly enhanced and increases in cathepsin D and L activities were observed, but there was no change in cathepsin B and H and acid phosphatase specific activities. These results indicate that BAT contains an important lysosomal proteolytic pathway that is involved in the rapid reduction of the tissue thermogenic capacity during a fast.     

Selective binding of lectins to embryonic chicken vasculature.

Chicken embryos are an excellent model system for studies related to vascular morphogenesis. Development in ovo allows manipulations otherwise difficult in mammals, and the use of chicken-quail chimeras offers an additional advantage to this experimental system. Furthermore, the chicken chorioallantoic membrane has been extensively used for in vivo assays of angiogenesis. Surprisingly, few markers are available for a comprehensive visualization of the vasculature. Here we report the use of lectins for identification of embryonic chicken blood vessels. Nine lectins were evaluated using intravascular perfusion and directly on sections. Our results indicate that Lens culinaris agglutinin, concanavalin A, and wheat germ agglutinin can be used effectively for visualization of vessels of early chicken embryos (E2.5-E4). At later developmental stages, Lens culinaris agglutinin is a better choice because it displays equal affinity for the endothelia of arteries, veins, and capillaries. The findings presented here expand our understanding of lectin specificity in the endothelium of avian species and provide information as to the use of these reagents to obtain comprehensive labeling of the embryonic and chorioallantoic membrane vasculature.     

Variation in virulence of Beauveria bassiana isolates and its relatedness to some morphological characteristics

Ten Beauveria bassiana isolates were characterized using the following parameters: virulence, morphological measurements, germination in solid and liquid media, in vitro growth and physiological changes in liquid media. There were significant differences in mortality of second-instar larvae of the diamondback moth (DBM), Plutella xylostella (Lepidoptera: Plutellidae) and the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Coleoptera, Chrysomelidae) according to isolate used (DBM; 14.51-53.37%, CPB; 25.05-74.07%). The most virulent isolates to DBM and CPB were KCF107 (soil origin) and KCF106 (Chilo suppressalis origin), respectively. Several morphological and physiological characteristics of isolates were evaluated for a possible link to virulence against both insect species. Special mean diameter (2.45-3.58 µm) and area of conidia (5.72-10.25 µm²) were significantly different among isolates. Time for 50% of conidia to germinate (GT₅₀) varied from 11 to 21 h depending on isolate. There was no correlation to virulence of size of conidia, GT_50, red pigment production and mycelial growth. Acidity of 7-day-old broth cultures of isolates was positively correlated with virulence. Iranian isolates KCF106 and KCF107 were the most promising and virulent isolates but field testing is needed to further evaluate their potential for use in DBM and CPB management.     

Design Optimization and Fabrication of Graphene/J-Aggregate Kretschmann-Raether Devices for Refractive Index Sensing Using Plasmon-Induced Transparency Phenomena

Plasmonics - Here, a novel plasmon-induced transparency (PIT) sensing platform based on a Kretschmann–Raether configuration with graphene/J-aggregate materials is proposed. The J-aggregate...     

Pd(II)-catalysed and Hg(II)-co-catalysed oxidation of D-glucose and D-fructose by N-bromoacetamide in the presence of perchloric acid: a kinetic and mechanistic study

The kinetics of Pd(II)-catalysed and Hg(II)-co-catalysed oxidation of D-glucose (Glc) and D-fructose (Fru) by N-bromoacetamide (NBA) in the presence of perchloric acid using mercury(II) acetate as a scavenger for Br- ions have been studied. The results show first-order kinetics with respect to NBA at low concentrations, tending to zero order at high concentrations. First-order kinetics with respect to Pd(II) and inverse fractional order in Cl- ions throughout their variation have also been noted. The observed direct proportionality between the first-order rate constant (k1) and the reducing sugar concentration shows departure from the straight line only at very higher concentration of sugar. Addition of acetamide (NHA) decreases the first-order rate constant while the oxidation rate is not influenced by the change in the ionic strength (mu) of the medium. Variation of [Hg(OAc)2] shows a positive effect on the rate of reaction. The observed negative effect in H+ at lower concentrations tends to an insignificant effect at its higher concentrations. The first-order rate constant decreases with an increase in the dielectric constant of the medium. The various activation parameters have also been evaluated. The products of the reactions were identified as arabinonic acid and formic acid for both the hexoses. A plausible mechanism involving HOBr as the reactive oxidising species, Hg(II) as co-catalyst, and [PdCl3.S]-1 as the reactive Pd(II)-sugar complex in the rate-controlling step is proposed.     

Analysis of HLA DR2&;DQ6 (DRB1*1501, DQA1*0102, DQB1*0602) Haplotypes in Iranian Patients with Multiple Sclerosis

Multiple sclerosis (MS) is prototype of inflammatory demyelinating disease of the central nervous system .The etiology of MS remains unclear, but according to current data the disease develops in genetically susceptible individuals and may require additional environmental triggers. The human leukocyte antigen (HLA) class II alleles (DRB1*1501, DQA1*0102, DQB1*0602) may have the strongest genetic effect in MS. In this study, the role of these alleles were investigated in 183 Iranian patients with multiple sclerosis and compared with 100 healthy individuals. HLA typing for DRB1*1501, DQA1*0102, DQB1*0602 was performed by polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP) method. The results show that, HLA DR B1*1501 was significantly more frequent among MS patients (46% vs. 20%, PV = 0.0006) but DQA1*0102 haplotype was negatively associated with MS (30% vs. 50%, PV = 0.0049) and no significant association was found with DQB1*0602 and MS patients in comparison with control group (24% and 30%, PV = 0.43). No significant correlation was observed among these alleles with sex, type of disease; initial symptoms, expanded disability status scale (EDSS), as well as age at onset and familial MS. This study therefore indicates that there is no association of above HLA haplotypes with clinical presentation, disease duration, and disability in Iranian patients with MS which is in line with other previous studies in different ethnic groups.     

Comparison of phenotypic and genetic performance of local silkworm groups and two commercial lines

Five Iranian native silkworm groups: Baghdad, Khorasan Orange, Guilan Orange, Khorasan Pink, Khorasan Lemon, and 107 and 110 commercial lines (12 families from each breed) were randomly selected and reared during 2003-2005 (five generations in spring and autumn). In each family, 30 male and 30 female cocoons were individually recorded for weight, shell weight and shell ratio. From among the native groups, the highest average in all three traits belonged to Baghdad and Khorasan Pink, and the lowest to Khorasan Orange and Khorasan Lemon. From among the commercial lines, the highest average in all three traits belonged to 107. In comparing heritability for cocoon weight in native groups, the highest heritability belonged to Guilan Orange (0.5147) and Khorasan Orange (0.5036) and the lowest heritability belonged to Khorasan Pink (0.0967). In the two other traits, the highest heritability belonged to Khorasan Orange and Baghdad and the lowest to Khorasan Pink. In the commercial lines, line110 had higher heritability than line107 for cocoon weight and cocoon shell weight. In all the groups, genetic correlations between cocoon weight and cocoon shell weight were high, expect for the Baghdad group. There was medium or low genetic correlation among cocoon weight, cocoon shell weight and cocoon shell ratio.