Mutation of bacterium Vibrio gazogenes for selective preparation of colorants

A novel marine bacterium strain effectively produced prodiginine type pigments. These colorants could dye wool, silk and synthetic fabrics such as polyester and polyacrylic and also show antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria on the dyed products. Methyl nitrosoguanidine was used as a mutation agent to increase the genetic diversity and the production yield of the bacteria of the family of Vibrio gazogenes. The analysis of the mutated samples showed that two new main colorants as well as three previously found ones were produced. Liquid chromatography electro spray ionization mass spectrometry (LC‐ESI‐MS) and nuclear magnetic resonance (NMR) spectroscopic techniques were used to elucidate the structures of the newly produced colorants. Mass measurements revealed that the colorants C1, C2, C3, C4 have molecular masses of 321, 323, 351, and 295 Da. One unstable colorant C5 with molecular mass of 309 Da was detected as well. The mutated bacteria strains increased the yield of pigment production by about 81% and produced prodigiosin in 97% purity. The antibiotic activities of pure colorants are discussed as well. Based on their bio‐activity and excellent dyeing capabilities, these colorants could be employed in cosmetic and textile industries. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010     

Superantigenic Activity of emm3 Streptococcus pyogenes Is Abrogated by a Conserved, Naturally Occurring smeZ Mutation

Streptococcus pyogenes M/emm3 strains have been epidemiologically linked with enhanced infection severity and risk of streptococcal toxic shock syndrome (STSS), a syndrome triggered by superantigenic stimulation of T cells. Comparison of S. pyogenes strains causing STSS demonstrated that emm3 strains were surprisingly less mitogenic than other emm-types (emm1, emm12, emm18, emm28, emm87, emm89) both in vitro and in vivo, indicating poor superantigenic activity. We identified a 13 bp deletion in the superantigen smeZ gene of all emm3 strains tested. The deletion led to a premature stop codon in smeZ, and was not present in other major emm-types tested. Expression of a functional non-M3-smeZ gene successfully enhanced mitogenic activity in emm3 S. pyogenes and also restored mitogenic activity to emm1 and emm89 S. pyogenes strains where the smeZ gene had been disrupted. In contrast, the M3-smeZ gene with the 13 bp deletion could not enhance or restore mitogenicity in any of these S. pyogenes strains, confirming that M3-smeZ is non-functional regardless of strain background. The mutation in M3-smeZ reduced the potential for M3 S. pyogenes to induce cytokines in human tonsil, but not during invasive infection of superantigen-sensitive mice. Notwithstanding epidemiological associations with STSS and disease severity, emm3 strains have inherently poor superantigenicity that is explained by a conserved mutation in smeZ.     

An in vitro assessment for evaluating the efficiency of β-d-mannuronic acid (M2000) in myelodysplastic syndrome

β-d -Mannuronic acid (M2000), a novel non-steroidal anti-inflammatory drug (NSAID) with immunosuppressive properties, has been previously shown to exhibit potential therapeutic effects on autoimmune diseases. Immunosuppression therapy has been a standard approach for myelodysplastic syndrome (MDS) for many years. We evaluated the effect of M2000 on isolated peripheral blood mononuclear cells (PBMCs) from patients with MDS. The PBMCs were isolated from 13 patients with MDS and 13 normal donors. The cells were then treated with low, moderate, and high doses of M2000 and diclofenac as a control group. The level of interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), IL-3, granulocyte colony-stimulating factor (G-CSF) gene expression and the serum level of IL-6 and TNF-α production were evaluated by real-time polymerase chain reaction and enzyme-linked immunosorbent assay methods, respectively. Our findings indicated a significant reduction in the production of IL-6 and TNF-α as inflammatory cytokines. Furthermore, the level of G-CSF gene expression was significantly increased. In conclusion, M2000, a newly designed NSAID, has a remarkable effect on isolated PBMC in patients with MDS, which might bring a potential hope for its oral administrations in these patients.     

Dietary Fat Influences the Expression of Contractile and Metabolic Genes in Rat Skeletal Muscle

Dietary fat plays a major role in obesity, lipid metabolism, and cardiovascular diseases. To determine whether the intake of different types of dietary fats affect the muscle fiber types that govern the metabolic and contractile properties of the skeletal muscle, we fed male Wistar rats with a 15% fat diet derived from different fat sources. Diets composed of soybean oil (n-6 polyunsaturated fatty acids (PUFA)-rich), fish oil (n-3 PUFA-rich), or lard (low in PUFAs) were administered to the rats for 4 weeks. Myosin heavy chain (MyHC) isoforms were used as biomarkers to delineate the skeletal muscle fiber types. Compared with soybean oil intake, fish oil intake showed significantly lower levels of the fast-type MyHC2B and higher levels of the intermediate-type MyHC2X composition in the extensor digitorum longus (EDL) muscle, which is a fast-type dominant muscle. Concomitantly, MyHC2X mRNA levels in fish oil-fed rats were significantly higher than those observed in the soybean oil-fed rats. The MyHC isoform composition in the lard-fed rats was an intermediate between that of the fish oil and soybean oil-fed rats. Mitochondrial uncoupling protein 3, pyruvate dehydrogenase kinase 4, and porin mRNA showed significantly upregulated levels in the EDL of fish oil-fed rats compared to those observed in soybean oil-fed and lard-fed rats, implying an activation of oxidative metabolism. In contrast, no changes in the composition of MyHC isoforms was observed in the soleus muscle, which is a slow-type dominant muscle. Fatty acid composition in the serum and the muscle was significantly influenced by the type of dietary fat consumed. In conclusion, dietary fat affects the expression of genes related to the contractile and metabolic properties in the fast-type dominant skeletal muscle, where the activation of oxidative metabolism is more pronounced after fish oil intake than that after soybean oil intake.     

A novel variant of t-PA resistant to plasminogen activator inhibitor-1; expression in CHO cells based on in silico experiments

Resistance to PAI-1 is a factor which confers clinical benefits in thrombolytic therapy. The only US FDA approved PAI-1 resistant drug is Tenecteplase?. Deletion variants of t-PA have the advantage of fewer disulfide bonds in addition to higher plasma half lives. A new variant was developed by deletion of the first three domains in t-PA in addition to substitution of KHRR 128-131 amino acids with AAAA in truncated t-PA. The specific activity of this new variant, 570 IU/μg, was found to be similar to those found in full length t-PA (Alteplase?), 580 IU/μg. A 65% and 85% residual activity after inhibition by rPAI-1 was observed for full length and truncated-mutant form, respectively. This new variant as the first PAI-1 resistant truncated t-PA may offer more advantages in clinical conditions in which high PAI-1 levels makes the thrombolytic system prone to re-occlusion.     

Effect of Selenium Nanoparticle Supplementation on Tissue Inflammation,Blood Cell Count,and IGF-1 Levels in Spinal Cord Injury-Induced Rats

Biological Trace Element Research - Selenium is known to be a neuroprotective agent in respect to a number of neuronal diseases and pain. The aim of this study was to evaluate the neuroprotective...     

Ambient Temperature and Cerebrovascular Hemodynamics in the Elderly

Background and Purpose

Some prior studies have linked ambient temperature with risk of cerebrovascular events. If causal, the pathophysiologic mechanisms underlying this putative association remain unknown. Temperature-related changes in cerebral vascular function may play a role, but this hypothesis has not been previously evaluated.

Methods

We evaluated the association between ambient temperature and cerebral vascular function among 432 participants ≥65 years old from the MOBILIZE Boston Study with data on cerebrovascular blood flow, cerebrovascular resistance, and cerebrovascular reactivity in the middle cerebral artery. We used linear regression models to assess the association of mean ambient temperature in the previous 1 to 28 days with cerebrovascular hemodynamics adjusting for potential confounding factors.

Results

A 10°C increase in the 21-day moving average of ambient temperature was associated with a 10.1% (95% confidence interval [CI], 2.2%, 17.3%) lower blood flow velocity, a 9.0% (95% CI, 0.7%, 18.0%) higher cerebrovascular resistance, and a 15.3% (95%CI, 2.7%, 26.4%) lower cerebral vasoreactivity. Further adjustment for ozone and fine particulate matter (PM_2.5) did not materially alter the results. However, we found statistically significant interactions between ambient temperature and PM_2.5 such that the association between temperature and blood flow velocity was attenuated at higher levels of PM_2.5.

Conclusions

In this elderly population, we found that ambient temperature was negatively associated with cerebral blood flow velocity and cerebrovascular vasoreactivity and positively associated with cerebrovascular resistance. Changes in vascular function may partly underlie the observed associations between ambient temperature and risk of cerebrovascular events.