Temperature dependence of the photodissociation of CO2 from high vibrational levels: 205-230 nm imaging studies of CO(X1Σ+) and O(3P, 1D) products.

The 205-230 nm photodissociation of vibrationally excited CO2 at temperatures up to 1800 K was studied using Resonance Enhanced Multiphoton Ionization (REMPI) and time-sliced Velocity Map Imaging (VMI). CO2 molecules seeded in He were heated in an SiC tube attached to a pulsed valve and supersonically expanded to create a molecular beam of rotationally cooled but vibrationally hot CO2. Photodissociation was observed from vibrationally excited CO2 with internal energies up to about 20 000 cm-1, and CO(X1Σ+), O(3P), and O(1D) products were detected by REMPI. The large enhancement in the absorption cross section with increasing CO2 vibrational excitation made this investigation feasible. The internal energies of heated CO2 molecules that absorbed 230 nm radiation were estimated from the kinetic energy release (KER) distributions of CO(X1Σ+) products in v″ = 0. At 230 nm, CO2 needs to have at least 4000 cm-1 of rovibrational energy to absorb the UV radiation and produce CO(X1Σ+) + O(3P). CO2 internal energies in excess of 16 000 cm-1 were confirmed by observing O(1D) products. It is likely that initial absorption from levels with high bending excitation accesses both the A1B2 and B1A2 states, explaining the nearly isotropic angular distributions of the products. CO(X1Σ+) product internal energies were estimated from REMPI spectroscopy, and the KER distributions of the CO(X1Σ+), O(3P), and O(1D) products were obtained by VMI. The CO product internal energy distributions change with increasing CO2 temperature, suggesting that more than one dynamical pathway is involved when the internal energy of CO2 (and the corresponding available energy) increases. The KER distributions of O(1D) and O(3P) show broad internal energy distributions in the CO(X1Σ+) cofragment, extending up to the maximum allowed by energy but peaking at low KER values. Although not all the observations can be explained at this time, with the aid of available theoretical studies of CO2 VUV photodissociation and O + CO recombination, it is proposed that following UV absorption, the two lowest lying triplet states, a3B2 and b3A2, and the ground electronic state are involved in the dynamical pathways that lead to product formation.

Prebiotic inulin: Useful dietary adjuncts to manipulate the livestock gut microflora.

In recent years, there has been a growing appreciation on the relevance of gastrointestinal microflora in both ruminants and non-ruminants owing to revelation of their role in several physiological functions including digestion, nutrient utilization, pathogen exclusion, gastrointestinal development, immunity system, gut gene expression and quality of animal products. The ban imposed on the use of antibiotics and hormones in feed has compelled animal researchers in finding an alternative which could overcome the issues of conventional feed additives. Though the concept of prebiotic was evolved keeping in mind the gastrointestinal flora of human beings, presently animal researchers are exploring the efficiency of prebiotic (inulin) for modulating the gut ecosystem of both ruminants and non-ruminants. It was revealed that prebiotic inulin is found to exhibit desirable changes in the gut of non-ruminants like poultry, swine, rabbit etc for augmenting gut health and improvement of product quality. Similarly, in ruminants the prebiotic reduces rumen ammonia nitrogen, methane production, increase microbial protein synthesis and live weight gains in calves. Unlike other feed additives, prebiotic exhibits its effect in multipronged ways for overall increase in the performances of the animals. In coming days, it is expected that prebiotics could be the part of diets in both ruminants and non-ruminants for enabling modulation of gut microflora vis a vis animals productivity in ecological ways.

A simple and efficient diffusion technique for assay of endo ß-1,4-xylanase activity.

Endo-ß-1, 4-xylanases is thought to be of great significance for several industries namely paper, pharmaceuticals, food, feed etc. in addition to better utilization of lignocellulosic biomass. The present investigation was aimed to develop an easy, simple and efficient assay technique for endo-ß-1, 4-xylanases secreted by the aerobic fungi. Under the proposed protocol, 9 g/L xylan containing agar was prepared in 100 mM phosphate buffer at different pH (4.5, 5.5 and 6.5). The sterilized xylan agar was dispensed in 90 mm petri dishes. 100 µl of culture supernatant of 12 fungal isolates was added to the wells and left overnight at 31±1(0)C. The petri dishes were observed for zone of clearance by naked eye and diameter was measured. Congo red solution (1 g/L) was applied over the petri dishes as per the established protocol and thereafter plates were flooded with 1M Sodium chloride solution for the appearance of zone of clearance. The diameter for zone of clearance by the proposed method and the established protocol was almost identical and ranged from 21 to 42 mm at different pH depending upon the activity of endo-ß-1, 4-xylanases. Change of pH towards alkaline side enabled similar or marginal decrease of diameter for the zone of clearance in most of the fungal isolates. The specific activities of these fungal isolates varied from 1.85 to 11.47 IU/mg protein. The present investigation revealed that the proposed simple diffusion technique gave similar results as compared to the established Congo red assay for endo-ß-1, 4-xylanases. Moreover, the present technique avoided the cumbersome steps of staining by Congo red and de-staining by sodium chloride.

Identification and characterization of specific receptors for monocyte-derived neutrophil chemotactic factor (MDNCF) on human neutrophils.

Specific receptors for a recently purified and cloned monocyte-derived neutrophil chemotactic factor (MDNCF) have been identified on the surface of normal human peripheral blood neutrophils using 125I-labeled recombinant human MDNCF (125I-MDNCF). Competitive binding of 125I-MDNCF to human neutrophils reached a maximal level at 1-3 h at 4 degrees C. The Scatchard analysis showed that there are approximately 20,000 receptors per cell with a single type of high affinity binding (Kd, 8 x 10(-10) M). The receptors for MDNCF are clearly distinct from the receptors for other cytokines and chemotactic agents, e.g., IL-1 alpha, TNF-alpha, and FMLP, C5a, leukotriene B4, and platelet activating factor. Based on the SDS-PAGE analysis of chemically crosslinked 125I-MDNCF receptor complex, there are two polypeptides that bind MDNCF; the molecular weight of these two MDNCF receptors were estimated to be 67,000 and 59,000. Treatment of a promyelocytic cell line, HL60, with 1.25% DMSO for 5 d in vitro increased the number of receptors up to 7,000 receptors/cell with a Kd of 1.2 x 10(-9) M.

Mutations in cytochrome B gene effects female reproduction of Ghungroo pig.

Cytochrome B is an important polypeptide of the mitochondria helpful in energy metabolism through oxidative phosphorylation. Cytochrome B plays an immense role in the reproduction of animals and due to its mutation prone nature, it can affect the basic physiology of animals. Cytochrome B affects reproductive system in males and equally plays an important role in transferring and providing energy in the development of the embryo, zygote, and oocytes precisely in females. The present study was conducted on Ghungroo pig to study their molecular and reproductive traits and the effect of the cytochrome B gene in the female reproduction of the Ghungroo pig. Although studies are available for cytochrome B gene analysis for evolutionary studies through phylogenetic analysis. This is the first report for the study of Cytochrome B gene on reproduction in pigs. Cytochrome B gene was sequenced and seven SNPs were observed out of which three were non-synonymous. INDEL mutation was detected in Variant B which had lead to Frame Shift mutation resulting in a stop codon AGA. The effect in the reproductive traits of the sow was studied due to the occurrence of nucleotide substitution. Bioinformatics analysis (I-mutant, PROVEAN, and SIFT) had revealed that the mutations were deleterious for the mutant type. Mutation leading to alterations in post-translational modification sites as phosphorylation site, leucine-rich nuclear export signal, occurrence of transmembrane helices, arginine and lysine peptide cleavage site for the mutant variant had resulted in a reduced physiological response. 3 D protein structure, (predicted through bioinformatics analysis) for cytochrome B has revealed distinct structural differences in mutated form with truncated protein by RMSD analysis through TM-Align software. Associated studies of genotype variants with reproductive traits have revealed the significant effect of variants of cytochrome B gene on reproductive traits namely litter size at first, second and third furrowing, piglet mortality, age at first furrowing and furrowing interval. Mitochondrial gene as Cytochrome B variants might be used as a marker for studying female reproduction of Ghungroo sow in future.

The presence of elements of a dinucleotide fold in UDP-glucose 4-epimerase from Saccharomyces fragilis.

UDPglucose 4-epimerase (EC 5.1.3.2) from Saccharomyces fragilis is a holoenzyme containing 1 mol NAD per mol dimeric protein. The enzyme can be dissociated with p-chloromercuribenzoate and can be reconstituted in the presence of 2-mercaptoethanol and exogenous NAD. Using Cibacron blue F3GA in this reconstituting system, competition between NAD and the dye for the pyridine nucleotide-binding site could be demonstrated. Inactive holoenzyme containing Cibacron blue can also be obtained under these conditions. These data suggest the possible presence of elements of a dinucleotide fold in this enzyme.

Regulation of interleukin-8 receptor expression in human polymorphonuclear neutrophils.

Interleukin-8, a neutrophil chemotactic agent, is known to have an active role in the induction of inflammatory response in a number of diseases. Although the activity of IL-8 is known to be through a receptor (IL-8R) on the surface of neutrophils, no information is available regarding the regulation of the IL-8R expression. The present study demonstrates that serum activated LPS at a concentration of 10 ng/ml induces expression of functionally active IL-8R by 120% within 30 min through de novo protein synthesis. The upregulated receptors could be detected by anti-IL-8R antibody and could also be demonstrated by autoradiography with crosslinking 125I IL-8. The serum-activated LPS-stimulated neutrophils migrated faster and showed higher Ca2+ flux over the unstimulated cells. The LPS-induced receptors were downregulated rapidly, about 85% of the receptor activity being lost within 90 min of incubation at 37 degrees C. The downregulation could be partially prevented by treatment with a cocktail of protease inhibitors, suggesting the possible involvement of protease(s) in this process. Both EDTA (100 microM) and bestatin (40 microM) afforded almost complete protection of the receptor from proteolytic cleavage indicating that the enzyme involved is a metalloprotease, possibly an aminopeptidase. The study shows that stimulation of PMNs with LPS leads to induction of IL-8R expression enhancing the IL-8-mediated biological responses and also provides evidence for post-stimulatory restoration of receptor level on the neutrophil surface by proteolytic cleavage of the amino-terminal end of the receptor.

Effect of feeding chayote (Sechium edule) meal on growth performance and nutrient utilization in indigenous pig (Zovawk) of Mizoram.

AIM: This study was planned to investigate the effect of feeding different levels of chayote (Sechium edule) meal by replacing standard concentrate mixture (CM) on the growth parameters such as feed intake, body weight gain, average daily gain (ADG) and feed conversion ratio (FCR), and nutrient utilization in indigenous pig of Mizoram. MATERIALS AND METHODS: Twenty-four growing indigenous pigs (Zovawk) were used to study the effect of feeding chayote (Sechium edule) meal (fruits and leaves at the ratio 4:1) on growth performance and nutrient utilization. They were allocated randomly into 4 treatment groups (G1, G2, G3, and G4). Chayote meal was used to replace standard CM (pig grower ration) at 0% (G1), 20% (G2), 30% (G3), and 40% (G4). RESULTS: During the feeding trial of 90 days, it was found that the dry matter (DM) intake decreased as the level of chayote meal increased. For G1, G2, G3, and G4, the ADG (kg) was 0.24±0.04, 0.23±0.03, 0.18±0.02, and 0.18±0.02, respectively, and the feed conversion efficiency was 5.42±0.44, 4.93±0.17, 5.38±0.05, and 5.74±0.53, respectively. However, there was no significant difference (p>0.05) among the different treatment groups in respect to ADG and FCR. At the end of the feeding trial, digestibility trial was conducted to study the effect of feeding chayote meal in the digestibility of the different nutrients by the experimental animals. From the digestibility trial, it was revealed that the digestibility coefficient of DM, crude protein, and crude fiber were also similar (p>0.05), although the ether extract digestibility in G1 was significantly low (p<0.01) as compared to G2, G3, and G4. CONCLUSION: Chayote meal could safely replace the standard grower ration up to 40% in the diet of growing local pigs without causing any adverse effects on growth and nutrient utilization.

Dansyl cadaverine regulates ligand induced endocytosis of interleukin-8 receptor in human polymorphonuclear neutrophils.

Interleukin-8 (IL-8), a neutrophil chemotactic agent, acts as a key mediator in a large number of acute and chronic inflammatory diseases. At 37 degrees C, the receptor for IL-8 is rapidly internalized with its ligand. But no specific inhibitor of this ligand induced internalization of the receptor has been reported so far. We have found that monodansyl cadaverine (MDC) inhibited about 70% of IL-8 induced endocytosis and caused 70% and 66% inhibition of IL-8 mediated chemotaxis and respiratory burst response, respectively, in neutrophils. The uninternalized receptor was detected by anti IL-8R antibody in MDC treated cells. The endocytosis of IL-8R was strongly inhibited under Ca2+ depleted conditions which was restored on addition of 1 mM CaCl2 indicating the critical involvement of a Ca2+ ion in the process. Absence of receptor internalisation makes the MDC treated neutrophils suitable for studying the interaction of IL-8R with potential therapeutic agents e.g. for in vitro screening of anti-inflammatory agents.

Upregulation of interleukin-8 receptor in human polymorphonuclear neutrophils by formyl peptide and lipopolysaccharide.

Interleukin-8 (IL-8) is implicated in the pathogenesis of a large number of neutrophil-driven inflammatory diseases. Although the cytokine activates neutrophils through a receptor, no information is available regarding the regulation of IL-8 receptor (IL-8R) expression. The present study shows that, compared to control, the bacterial products--formylpeptide and LPS (serum-activated) upregulate IL-8 receptor by 54% and 115%, respectively, the former by degranulation of the secretory vesicle and the latter by de novo protein synthesis. The newly expressed IL-8R could be demonstrated with anti-IL-8R-antibody and by autoradiogram of the receptor crosslinked with [125I]IL-8. The study may be useful for understanding the potential role of IL-8 during neutrophil mediated inflammatory response.

Functions of interleukin-8 are mediated through thiol group(s) of IL-8 receptor in human polymorphonuclear neutrophils. Effects of 5,5'-dithio-bis(2-nitrobenzoic acid) on IL-8 receptor.

Interleukin-8, a neutrophil chemotactic agent causes excessive accumulation of the cells in a number of inflammatory diseases. The activity has been shown to be mediated through a specific functional receptor present on the surface of neutrophils. No information is available about the amino acids constituting the IL-8 binding domain of the receptor. Treatment of neutrophils with 5,5'-dithio-bis(2-nitrobenzoic acid), a thiol-specific modifier, at the concentrations of 0.4 mM and 1 mM reduced IL-8 binding ability and IL-8-induced migration of the cells by 45% and 65%, respectively. Dithiothreitol could regenerate the binding capacity and the ligand could protect the receptor from the effect of the reagent. All the evidence suggests that one or more critical thiol residues are located in the IL-8 binding site of the receptor which are indispensible for normal functions of IL-8.

Regulation of chemokine receptor CCR5 and production of RANTES and MIP-1alpha by interferon-beta.

Trafficking of inflammatory T cells into the brain is associated with interactions of certain chemokines with their receptors, which plays an important role in the pathogenesis of multiple sclerosis (MS). We examined whether interferon-beta (IFN-beta) had the ability to regulate the production of chemokines and the expression of their receptors in T cells derived from patients with MS. It was demonstrated for the first time that in vitro exposure of T cells to IFN-beta-1a selectively inhibited mRNA expression for RANTES and MIP-1alpha and their receptor CCR5. T cell surface expression of CCR5 was significantly reduced in MS patients treated with IFN-beta, correlating with decreased T cell transmigration toward RANTES and MIP-1alpha. The study provides new evidence suggesting that IFN-beta treatment impairs chemokine-induced T cell trafficking by reducing the production of RANTES and MIP-1alpha and the expression of their receptors CCR5.

Binding of Escherichia coli heat-stable enterotoxin and rise of cyclic GMP in COLO 205 human colonic carcinoma cells.

Escherichia coli heat-stable enterotoxin (STa) was found to bind on the surface of human colonic (COLO 205) cells. The binding of [125I]STa to cell membranes was found to be specific, reversible and saturable. Scatchard analysis of the equilibrium binding demonstrated a single class of binding sites with a Kd of 0.5 x 10(-10) M. Autoradiographic analysis of polyacrylamide gel electrophoresis revealed the specific incorporation of [125I]STa into a single STa binding protein with a molecular mass of 95 kDa. Following incubation of COLO 205 cells with STa, a rise of intracellular cGMP was also evident.

Homogeneous enzyme immunoassay of estradiol using estradiol-3-O-carboxymethyl ether as hapten.

A homogeneous enzyme immunoassay for estradiol estimation has been developed, which can be extended to other steroids. A new procedure for the preparation of estradiol -3-0- carboxymethyl ether by a simple one step reaction in high yield (90%) has been described. This hapten has been used for raising highly specific anti-estradiol antibody in rabbits and for preparation of enzyme conjugates. Two different enzymes, lysozyme and glucose -6- phosphate dehydrogenase have been studied for their suitability as enzyme labels. Our results indicate that lysozyme-conjugate meets the essential requirement for a practical enzyme immunoassay. The advantage of the present nonradioactive procedure is the overall simplicity, low cost and high stability of the reagents.

Mycoversilin, a new antifungal antibiotic. I. Fermentation, isolation and biological properties.

A new antifungal antibiotic, mycoversilin, was isolated from the culture filtrate of Aspergillus versicolor (N5)17 by repeated column chromatography and recrystallized from ethyl acetate as homogeneous fine needles. Maximum production took place in a medium containing 4% glucose and 1% peptone at pH 3.5, temperature 28 degrees C after 8-9 days of incubation under stationary condition. Mycoversilin is a narrow spectrum antibiotic with activity against filamentous fungi, particularly Trichophyton rubrum (MIC 15 micrograms/ml).

Mycoversilin, a new antifungal antibiotic. II. Structure elucidation.

The structure of a new antifungal antibiotic, mycoversilin, produced by Aspergillus versicolor (N5)17 was determined as I by various spectroscopic and chemical methods. Mycoversilin is a unique polynuclear aromatic compound having two methyl and six hydroxyl groups and two ether linkages. The acetyl derivative prepared was found to have no antifungal property.

Role of porta systemic shunt and hepatocellular damage in the genesis of hepatic neuropathy.

A study was undertaken to evaluate the relative role of porta-systemic shunts and hepatocellular damage in the genesis of neuropathy in chronic liver disease. Two of the 14 patients with non-alcoholic cirrhosis showed clinical evidence of neuropathy, whereas none of the patients with idiopathic portal fibrosis had evidence of neuropathy clinically. Decreased motor conduction velocities were present in some cases of idiopathic portal fibrosis as well as non-alcoholic cirrhosis. Subclinical evidence of histopathological neuropathy in the form of segmental demyelination and remyelination as well as myelin fiber loss was seen in 10 out of 11 sural nerves studied in idiopathic portal fibrosis group and in all the 10 patients in the non-alcoholic cirrhosis group. No correlation was found between histological features and various parameters studied. It is postulated that the development of clinical or subclinical neuropathy in chronic liver disease depends on two factors, being collateral shunting and hepatocellular damage or both and probably related to abnormalities of nitrogen metabolism.

The identification and quantitation of alkylated nucleobases by high-performance liquid chromatography with UV photodiode array detection.

The application of UV diode array detection in high-performance liquid chromatographic (HPLC) identification and quantitation of several classes of synthetic and commercially available alkylated nucleobases is investigated. Quantitative spectral overlays of these compounds to methyl standard references from a spectral library and absorbance ratios at two maximal wavelengths (lambda max) are found to be useful in categorizing the solutes. They can be grouped into classes of compounds originating from a specific nucleobase and classes of analogs having different alkyl substituents (e.g., methyl, ethyl, propyl, allyl, and benzyl) at the same position of the heterocycle. At a selected wavelength for alkylated nucleobases in the same class, the detector response factors are independent of the alkyl group (+/- 10%). This technique provides a practical means for both qualitative and quantitative analysis of product distribution of DNA base alkylation by using only readily obtainable methylated derivatives as the reference standards.

An aminopeptidase regulates LPS stimulated interleukin-8 receptor on the surface of human neutrophils.

A large number of inflammatory diseases are mediated by interleukin-8, an inflammatory neutrophil chemotactic agent. Since the cytokine acts through a cell surface receptor, detailed knowledge about the regulation of receptor expression is very important. We found that LPS in serum became activated and triggered the expression of IL-8 receptor by more than two folds within 30 min. After that period, the receptor attained normal level within 2 hr of SA-LPS stimulation. EDTA and bestatin could block this downregulation of IL-8 receptor. Intracellular Ca2+ level was increased till 45 min of SA-LPS stimulation and then the level was reduced. Addition of CaCl2 accelerated and depletion of Ca2+ inhibited the downregulation of the IL-8 receptor. The ligand could fully protect the loss of receptor from downregulation. It suggests that during SA-LPS stimulation, increase in intracellular Ca2+ level activates an aminopeptidase which presumably cleaves the N-terminal region of the receptor, critically essential for the function of IL-8. Thus the activated aminopeptidase regulates the functions of IL-8. The study is important for understanding the regulation of IL-8 receptor expression by LPS during bacterial infection.

Application of pigeon pea (Cajanus cajan) stalks as raw material for xylooligosaccharides production.

Pigeon pea (Cajanus cajan) is a perennial plant widely cultivated in tropical and subtropical regions of many countries. The present studies aimed to produce xylooligosaccharides (XOS) from pigeon pea stalks in order to do value addition. The chemical analysis of stalks revealed 18.33 ± 1.40 % hemicelluloses in addition to cellulose, protein, and lignin. Sodium hydroxide coupled with steam application enabled almost 96 % recovery of original xylan, present in the pigeon pea stalks. Enzymatic hydrolysis of xylan led to production of XOS namely, xylobiose and xylotriose. Response surface model indicated a maximum yield of xylobiose (0.502 mg/ml) under the hydrolysis conditions of pH 4.91, temperature at 48.11 °C, enzyme dose at 11.01 U, and incubation time at 15.65 h. The ideal conditions for higher xylotriose yield (0.204 mg/ml) were pH 5.44, temperature at 39.29 °C, enzyme dose at 3.23 U, and incubation time at 15.26 h. The present investigation was successful in assessing the prospect of using pigeon pea stalks as a raw material for xylan extraction vis-à-vis XOS production.