Molecular basis of phenotypic variation in patients with argininemia

Argininemia is an autosomal recessive disorder caused by a deficiency in the liver-type arginase enzyme. Clinical manifestations include progressive spastic diplegia and mental retardation. While the quality of life can severely deteriorate in most such patients, some do show remarkable improvement in neurological symptoms while on controlled diets. We examined the thesis that differences in clinical responses to dietary treatment are based on molecular heterogeneity in mutant arginase alleles. Genomic DNAs from 11 patients with argininemia were examined using the polymerase chain reaction, cloning, and sequencing. Nine mutations representing 21/22 mutant alleles were identified in 11 patients with argininemia, and four of these mutations were expressed in vitro to determine the severity of enzymatic defects. We found that these mutations accounted for 64% of the mutant alleles in our patients. Based on findings in vitro expression tests, the mutations can be considered either severe or moderate. Patients with at least one moderate mutant allele responded well to dietary treatment; concentrations of plasma arginine were controlled within 300 M. In contrast, patients with two severely mutated alleles did not respond to dietary treatment and plasma arginine was over 400 M. Argininemia is heterogeneous at the molecular level. The degree of clinical improvement during dietary treatment is reflected in the concentration of arginine in plasma, as a measure of metabolic control. Plasma arginine levels during treatment is reflected in the concentration of arginine in plasma, as a measure of metabolic control. Plasma arginine levels during treatment correlated with types of molecular defects in the arginase genes.     

Heterotypic passive protection induced by synthetic peptides corresponding to VP7 and VP4 of bovine rotavirus.

We have evaluated the potential of two peptides derived from highly conserved regions of rotavirus outer capsid proteins (VP7 and VP4) to act as a rotavirus vaccine. The capacity of peptides coupled to rotavirus VP6 spherical particles to provide passive protection in a murine model was compared with the protection induced by peptide-keyhole limpet hemocyanin (KLH) conjugates. Female mice were immunized a total of three times before and during pregnancy. Suckling mouse pups were challenged at 7 days of age with either homologous or heterologous rotavirus serotypes. The efficacy of vaccination was determined by analyzing the clinical symptoms and measuring xylose adsorption in the intestine. In this model the VP4 peptide-VP6 conjugate provided protection equal to that obtained using bovine rotavirus (BRV) as the immunogen. The VP7 peptide-VP6 conjugate provided slightly less protection than the VP4 peptide-VP6 conjugate. A mixture of the VP4 peptide-VP6 and VP7 peptide-VP6 conjugates provided better heterologous protection than immunization with BRV. In contrast, KLH-conjugated peptides provided only partial protection. The significance of a synthetic-peptide-based rotavirus vaccine in the prevention of rotavirus infections is discussed.     

Comparison of the airborne survival of calf rotavirus and poliovirus type 1 (Sabin) aerosolized as a mixture.

A mixture of a cell culture-adapted strain (C-486) of calf rotavirus and poliovirus type 1 (Sabin) was prepared in tryptose phosphate broth containing 0.1% uranine (physical tracer) and antifoam at a final concentration of 0.001%. By using a six-jet Collison nebulizer, the mixture was aerosolized into a 300-liter stainless-steel rotating (4 rpm) drum. The temperature of the air inside the drum was kept at 20 +/- 1 degrees C, and the virus aerosols were held at the following three levels of relative humidity (RH): low (30 +/- 5%), medium (50 +/- 5%), and high (80 +/- 5%). An all-glass impinger, containing 10.0 ml of tryptose phosphate broth with antifoam, was used to collect samples of air from the drum. Both viruses were propagated and quantitated in MA-104 cells. The calf rotavirus was found to survive well at mid-range RH, where 60% of the infectious virus could be detected even after 24 h of virus aerosolization. At the low RH, the half-life of the infectious rotavirus was ca. 14 h. On the other hand, no infectious poliovirus could be recovered from the drum air at the low and medium RH. At the high RH, more than 50% of the infectious rotavirus became undetectable within 90 min of aerosolization. In contrast to this, the half-life of the poliovirus at the high RH was about 10 h. These data, based on the aerosolization of virus mixtures, therefore suggest that there is a pronounced difference in the way RH influences the airborne survival of these two types of viruses held under identical experimental conditions.     

Upstream and Downstream Processing of Lovastatin by Aspergillus terreus

The present study describes the enhanced production and purification of lovastatin by Aspergillus terreus in submerged batch fermentation. The enhancement of lovastatin production from A. terreus was attempted by random mutagenesis using ultraviolet radiations and nitrous acid. UV mutants exhibited increased efficiency for lovastatin production as compared with nitrous acid mutants. Among all the mutants developed, A. terreus UV-4 was found to be the hyper producer of lovastatin. This mutant gave 3.5-fold higher lovastatin production than the wild culture of A. terreus NRRL 265. Various cultural conditions were also optimized for hyper-producing mutant strain. 5 % glucose as carbon source, 1.5 % corn steep liquor as nitrogen source, initial pH value of 6, 120 h of incubation period, and 28 °C of incubation temperature were found as best parameters for higher lovastatin production in shake flasks. Production of lovastatin by wild and mutant strains of A. terreus was also scaled up to laboratory scale fermentor. The fermentation process was conducted at 28 °C, 200 rpm agitation, and 1vvm air flow rate without pH control. After the optimization of cultural conditions in 250 ml Erlenmeyer flasks and scaling up to laboratory scale fermentor, the mutant A. terreus UV-4 gave eightfold higher lovastatin production (3249.95 μg/ml) than its production by wild strain in shake flasks. Purification of lovastatin was carried out by solvent extraction method which yielded 977.1 mg/l of lovastatin with 98.99 % chromatographic purity and 26.76 % recovery. The crystal structure of lovastatin was determined using X-ray diffraction analysis which is first ever reported.     

A bioconvection model for viscoelastic nanofluid confined by tapered asymmetric channel: implicit finite difference simulations

As part of the growing evolution in nanotechnology and thermal sciences, nanoparticles are considered as an alternative solution for the energy depletion due to their ultra-high thermal effectives. Nanofluids reflect inclusive and broad-spectrum significances in engineering, industrial and bio-engineering like power plants, energy source, air conditioning systems, surface coatings, evaporators, power consumptions, nano-medicine, cancer treatment, etc. The present study describes the bio-convective peristaltic flow of a third-grade nanofluid in a tapered asymmetric channel. Basic conservation laws of mass, momentum, energy, and concentration as well as the microorganism diffusion equation are utilized to model the problem. The simplified form of the modeled expressions is accounted with long wavelength assumptions. For solving the resulting coupled and nonlinear equations, a well-known numerical method implicit finite difference scheme has been utilized. The graphical results describe the velocity, temperature and concentration profiles, and the density of motile microorganisms at the nanoscale. Furthermore, microorganism concentration lines are analyzed.

     

Antioxidant phenylpropanoid glycosides from Buddleja davidii

Phytochemical investigations on the n-BuOH-soluble fraction of the whole plant of Buddleja davidii led to the isolation of the phenylpropanoid glycosides 1-10. Their structures were determined by 1D and 2D NMR spectroscopic techniques. All the compounds showed potent antioxidative activity in three different tests, with IC₅₀ values in the range 4.15-9.47 μM in the hydroxyl radical (˙OH) inhibitory activity test, 40.32-81.15 μM in the total ROS (reactive oxygen species) inhibitory activity test, and 2.26-7.79 μM in the peroxynitrite (ONOO^?) scavenging activity test. Calceolarioside A (1) displayed the strongest scavenging potential with IC₅₀ values of (4.15?±?0.07, 40.32?± 0.09, 2.26?±?0.03μM) for ˙OH, total ROS and scavenging of ONOO^?, respectively.     

Urease and Serine Protease inhibitory alkaloids from Isatis tinctoria

Phytochemical investigations on the alkaloidal fraction of the whole plant of the Isatis tinctoria led to the isolation of the alkaloids 1-6., 3′-Hydroxyepiglucoisatisin (3), Epiglucoisatisin (2) were found to be potent urease inhibitors in a concentration-dependent manner with IC₅₀ values 25.63 ± 0.74, 37.01 ± 0.41 and 31.72 ± 0.93, 47.33 ± 0.31 μM against Bacillus pasteurii & Jack bean urease, respectively. Compounds 3 and 2 also showed potent inhibitory potential against α-chymotrypsin with IC₅₀ values of 23.40 ± 0.21 and 27.45 ± 0.23 μM, respectively.