Alterations of serum and saliva oxidative markers in patients with bronchial asthma

BACKGROUNDS

The development of asthma is highly affected by exposure to exogenous and endogenous oxidative molecules, but the impact of this exposure on the pathophysiology of asthma has received little attention.

OBJECTIVES

Evaluating group of selective oxidative stress markers as a tool in the management of asthma disease.

METHODS

In comparison with matched healthy controls, levels of the oxidant and antioxidant markers: lipid peroxidation malondialdehyde (MDA), Total glutathione (tGSH), Uric acid (UA), Glutathione peroxidase (GPx), Catalase (CAT) superoxide dismutase (SOD), and Total antioxidant capacity (TAC) were assessed in serum and saliva of different asthma groups.

RESULTS

All oxidative markers in serum and saliva of asthma patients showed significant alterations from normal healthy controls (P < 0.05), except the salivary SOD (P = 0.441). Their levels in serum were significantly correlated with asthma severity (P < 0.05), and the distinguishing between childhood and adult asthma was significantly accomplished by GPx, SOD, TAC markers (P < 0.05). However, in patients with childhood asthma no significant differences were detected between the levels of GPx, CAT, UA, MDA in serum and saliva samples (P > 0.05).

CONCLUSION

Determination of the oxidative markers GPx, CAT, UA in serum or saliva can distinguish asthma from healthy states. The serum levels of UA and TAC are highly effective in monitoring asthma severity, while the salivary GPx, CAT, UA, MDA are beneficial in the management of childhood asthma. Discrimination of the age factor between asthma groups can be achieved by testing GPx, SOD, TAC in serum.

Association of RETN +299(G>A) polymorphism with type two diabetes mellitus

The global prevalence of type-two diabetes mellitus (T2DM) makes it a disease of public health concern. T2DM is strongly linked with insulin resistance caused by increased levels of visceral fat. Visceral fat secretes several adipocytokines that regulate body metabolism. Resistin is one of these adipocytokines which is encoded by the RETN gene. Herein, we tested the association of the RETN +299(G>A) and -420(C>G) single nucleotide polymorphisms (SNPs) with T2DM. T2DM patients (n=282) and healthy subjects (n=125) were included in the study. Subjects with metabolic syndromes other than diabetes were excluded. Genotyping of subjects was performed using PCR-RFLP. The +299(G>A) SNP was associated with T2DM (P=0.038). The AA genotype was higher in T2DM (17%) compared to controls (8%) with an odd ratio of 2.16 and 95% CI of 1.34 to 4.56. With respect to -420(C>G) SNP, no significant association was found with the risk of T2DM (P=0.128). The haplotype analysis of the examined SNPs indicated that the CA haplotype of the -420 and +299 SNPs in RETN was associated with T2DM risk (P=0.004; odd ration 4.0, 95% CI: 1.56-10.0). In conclusion, the present findings suggest a role of the RETN locus in modulating the risk of T2DM.

Antibacterial activity in vitro of Thymus capitatus from Jordan

This study was carried out to evaluate the antibacterial activity of aqueous and organic extracts of Thymus capitatus L. (Lamiaceae) leaves and stems. Dried ground powder leaves and stems were extracted with water (aqueous extracts), ethanol, dichloromethane and hexane (Soxhlet extracts). The antibacterial activity of these extracts was evaluated against bacteria using disc diffusion method. The result obtained showed that the leaves had stronger antibacterial activity than the stems extracts. The ethanolic extract had the highest yield products and the high antibacterial activity than all other solvents. The results suggest that essential oil as non-polar organic compounds could be the main active compounds in this plant. Therefore the antibacterial activity of leaves ethanol extracts (LEE) was compared with essential oils leaves extracts (LEO) of T. capitatus. The LEO showed greater antibacterial activity than LEE. The LEO showed a broad spectrum of antibacterial activity and the Pseudomonas aeruginosa was the most sensitive bacteria.

Effects of Carbon Source and Vitreoscilla Hemoglobin (VHb) on the Production of β-Galactosidase in Enterobacter aerogenes

At fixed concentration (0.5%), lactose and galactose acted as inducers while glucose and other tested carbon sugars showed repression effects on beta-galactosidase production in Enterobacter aerogenes strain. The expression of Vitreoscilla hemoglobin gene (vgb) in this bacterial strain managed to overcome the repression effects as well as improving the induction of beta-galactosidase formation by carbon sources. In parallel, the bacterial O(2) consumption was increased correspondingly to the vgb induction of beta-galactosidase synthesis. When Enterobacter aerogenes strains were grown at the incubation temperature 42 degrees C, about 5-fold higher enzyme productivity was obtained than with a similar incubation at 37 degrees C. The bacterial growth expressed as biomass yield had a different optimum temperature and was not influenced to the same extent by variations in the carbon sources. These data are discussed in terms of proposed enhancement in beta-galactosidase productivity by vgb expression as well as its significance to improve the technology of whey processing.

Correlation between bacterial haemoglobin gene (vgb) and aeration: their effect on the growth and alpha-amylase activity in transformed Enterobacter aerogenes

AIMS

To evaluate the effects of bacterial haemoglobin on bacterial growth and alpha-amylase formation under different aeration conditions.

METHODS AND RESULTS

Enterobacter aerogenes was transformed with the gene encoding Vitreoscilla (bacterial) haemoglobin, vgb. The growth kinetics and ability to synthesize alpha-amylase enzyme were investigated in this transformed Enterobacter strain as well as in two other Enterobacter control strains that do not harbour the vgb gene. Such comparison was made under variable aeration conditions, using the agitation rate as a measure of aeration. The expression of bacterial haemoglobin-supported cell growth determined as O.D.600 and cell viability in addition to the alpha-amylase production. These positive effects of bacterial haemoglobin were observed under both low and high aerations, but at different extents.

CONCLUSIONS

In addition to improving cell growth under low aeration, the bacterial haemoglobin is able to promote bacterial cell tolerance during exposure to high oxygen tension.

SIGNIFICANCE AND IMPACT OF THE STUDY

The expression of bacterial haemoglobin is advantageous in reducing the burden of certain toxic conditions such as high oxygen levels. It may have the same impact on some environmental toxic substances. This, haemoglobin biotechnology can be extended to induce enzymes of pollutants degradation or production of some useful industrial substances.

The DNA polymerases associated with the adenovirus type 2 replication complex: effect of 2'-3'-dideoxythymidine-5'-triphosphate on viral DNA synthesis

An adenovirus (Ad) DNA replication complex extracted from infected HeLa nuclei could be purified free of the bulk of intracellular DNA polymerase activity by sedimetation in neutral sucrose gradients. However, the replication complex still retained some alpha and gamma DNA-polymerase activity. Since this complex is inhibited by 2', 3' dideoxythymidine-5'-triphosphate (ddTTP), an inhibitor of DNA polymerase gamma, a functional role for this enzyme in Ad DNA replication is suggested. Similar inhibition by ddTTP in intact Ad infected nuclei and comparable inhibition of Ad DNA synthesis in whole cells by dideoxythymidine (ddThy) are consistent with a role for DNA polymerase gamma. Uninfected HeLa nuclei or whole cells are not similarly inhibited by ddTTP or DDThy respectively. Such data does not rule out an additional functional role for other DNA polymerases, and recent experiments from this laboratory (1) suggest that DNA polymerase alpha is also involved in Ad DNA synthesis.

Apparent suicidal inactivation of DNA polymerase by adenosine 2',3'-riboepoxide 5'-triphosphate

Adenosine 2',3'-riboepoxide 5'-triphosphate (epoxyATP) has been found to be a suicidal inactivator of DNA polymerase I from Escherichia coli by the following criteria. Inactivation is complete, is first order in enzyme activity, and shows saturation kinetics with an apparent KD of 30 +/- 10 micron for epoxy ATP. This KD is comparable to the KM of the substrate dATP. The t1/2 for inactivation is 1.3 min. Inactivation requires Mg2+ and the complementary template. The enzyme is protected by dATP but not by an excess of template. Gel filtration of the reaction mixture after inactivation with [3H]epoxy ATP results in the comigration of E. coli DNA polymerase I, the tritium-labeled inactivator, and the DNA template. The stoichiometry of binding approaches 1 mol of [3H]epoxy nucleotide per mol of inactivated enzyme. These results are consistent with the hypothesis that epoxy ATP initially serves as a substrate for the polymerase reaction, elongating the DNA chain by a nucleotidyl unit, and subsequently alkylates an essential base at the primer terminus binding site of the enzyme. Epoxy ATP also inactivates human and viral DNA polymerases but not E. coli RNA polymerase or rabbit muscle pyruvate kinase. Hence epoxy ATP may be a specific suicide reagent for DNA polymerases.

Mechanism and stereochemistry of enzymic reactions involved in porphyrin biosynthesis

5-Aminolaevulinate synthetase cataylses the condensation of glycine and succinyl-CoA to give 5-aminolaevulinic acid. At least two broad pathways may be considered for the initial C--C bond forming step in the reaction. In pathway A the Schiff base of glycine and enzyme bound pyridoxal phosphate (a) undergoes decarboxylation to give the carbanion (b) which then condenses with succinyl-CoA with the retention of both the original C2 hydrogen atoms of glycine. In pathway B, loss of a C2 hydrogen atom gives another type of carbanion (c) that reacts with succinyl-CoA. Evidence has been presented to show that the initial C--C bond forming event occurs via pathway B which involves the removal of the pro R hydrogen atom of glycine. Subsequent mechanistic and stereochemical events occurring at the carbon atom destined to become C5 of 5-aminolaevulinate have also been delineated.(Carticle) Several mechanistic alternatices for the formation of the two vinyl groups of haem from the propionate residues of the precursor, coproporphyrinogen III, have been examined. (see article). It is shown that during the biosynthesis both the hydrogen atoms resident at the alpha positions of the propionate side chains remain undisturbed thus eliminating mechanisms which predict the involvement of acrylic acid intermediates. Biosynthetic experiments performed with precursors containing stereospecific labels have shown that the two vinyl groups of haem are formed through the loss of pro S hydrogen atoms from the beta-positions of the propionate side chains. In the light of these results, three related mechanisms for the conversion, propionate leads to vinyl, have been considered. In order to study the mechanism of porphyrinogen carboxy-lyase reaction, stereo-specifically deuterated, tritiated-succinate was incorporated into the acetate residues of uroporphyrinogen III which on decarboxylation generated asymmetric methyl groups in coproporphyrinogen III and then in haem. Degradation of the latter yielded chiral acetate deriving from C and D rings of haem. Configurational analysis of this derivate acetate shows that the carboxy-lyase reaction proceeds with a retention of configuration.