[Significance of opioid receptors in regulation of cardiac tolerance in pathogenic impact of long-term ischemia-reperfusion in vivo].

The study aimed at investigation of the role of opioid receptor (OR) in regulation of cardiac tolerance to ischemia-reperfusion. Opioid receptor ligands and inhibitors were administered in vivo prior to coronary artery occlusion (45 min) and reperfusion (2 hrs). Occurring infraction size/area at risk (IS/AAR) ratio was determined. Pretreatment with the micro-OR agonists DAMGO and dermorphin H exerted no effect on the IS/AAR ratio. Activation of delta 1-OR by DPDPE did not alter cardiac tolerance in ischemia-reperfusion either. Pretreatment with the delta 2-OR agonists deltorphin D and deltorphin E or ORL1 receptor agonist nociceptin exerted no effect on the IS/AAR ratio. Stimulation of K-OR by selective agonists did not modify cardiac tolerance to ischemia-reperfusion. The delta 2-OR agonist deltorphin II significantly reduced the IS/AAR index. This effect was prevented by treatment with naltrexone, naloxone methiodide and the delta 2-OR antagonist naltriben but not by the delta 1-OR antagonist BNTX. The infarction-limiting effect of deltorphin II was also abolished by inhibition of protein kinase C (PKC) and mitochondrial Katp channels. Thus, the agonists of micro, delta 1, kappa, and ORL1 receptors in used doses did not affect cardiac tolerance in ischemia-reperfusion injury in vivo. The peripheral delta 2-OR activation induces infarction size reduction. Its infarction-reducing effect of deltorphin II is mediated via PKC activation and mitochondrial Katp, channel opening.

Optimizing qPCR for the Quantification of Periodontal Pathogens in a Complex Plaque Biofilm.

Quantitative PCR (qPCR) has recently been used to quantify microorganisms in complex communities, including dental plaque biofilms. However, there is variability in the qPCR protocols being used. This study was designed to evaluate the validity of two of these variables with the intent of developing a more standardized qPCR protocol. The two variables evaluated were (1) the use of DNA content versus actual cell counts to estimate bacterial numbers in mixed plaque samples and (2) the effectiveness of three different universal primers versus species specific primers in amplifying specific target pathogens in these samples. Results lead to the development of a standardized protocol that was shown to be highly reproducible as demonstrated by low coefficients of variation. The results also confirmed that this standardized qPCR protocol can be used as a sensitive method for quantifying specific bacterial species in human plaque samples.

Effects of low-energy shock waves on oral bacteria.

We have recently demonstrated that extracorporeal shock-wave therapy (ESWT) is effective in promoting the healing of dermal wounds and in regenerating alveolar bone lost through periodontal disease. The objective of the present study was to determine any antibacterial effect of ESWT on oral bacteria. Monoculture suspensions of 6 bacterial species were treated with 100 to 500 pulses of ESWT at energy flux densities (EFD) of 0.12 mJ/mm(2), 0.22 mJ/mm(2), and 0.3 mJ/mm(2). Following treatment, aliquots were plated for viability determination and compared with untreated controls. ESWT showed a significant microbicidal effect for Streptococcus mutans and an unencapsulated strain of Porphyromonas gingivalis following as few as 100 pulses at 0.3 mJ/mm(2) (p 0.05). These findings suggest that low-energy ESWT may be bactericidal for selected oral bacteria.

[Comparative study of the antiarrhythmic activity of mu- and delta-opioid receptor agonists during acute cardiac ischemia and reperfusion models in rats].

It has been established that pretreatment with the selective mu-opioid receptor (OR) agonist DALDA (0.1 mg/kg, i.v.) or the selective delta1-OR agonists DPDPE (0.09 mg/kg) and/or (-)-TAN-67 (0.08 mg/kg) has no effect on the incidence of ventricular arrhythmias induced by a 10-min coronary artery occlusion and a 10-min reperfusion in ketamine-anesthetized rats. In contrast, the pretreatment with the selective delta2-OR agonist deltorphin II (0.12 mg/kg) and the proposed delta2-OR agonists deltorphin D (0.3 mg/kg) and/or dermorphin H (0.23 mg/kg) increases cardiac resistance to the arrhythmogenic action of acute ischemia and reperfusion. Administration of the mixed mu- and delta-OR agonist dalargin (0.12 mg/kg) 15 min before the coronary artery ligation abolished only the reperfusive ventricular fibrillation. It is concluded that peptidergic stimulation of delta2-ORs can be used as a new means of increasing cardiac tolerance to the arrhythmogenic effects of acute ischemia and reperfusion.

Phylogenetic comparison of two polycyclic aromatic hydrocarbon-degrading mycobacteria.

Two mycobacterial strains previously isolated from fossil-fuel-contaminated environments and shown to degrade four- and/or five-ring polycyclic aromatic hydrocarbons were further characterized. The two strains, PYR-I and RJGII-135, had similar growth characteristics, colony morphologies, and scotochromogenic pigmentations. DNA amplification fingerprints obtained with total genomic DNA indicated some strain similarities but with several distinctly different bands. Moreover, phylogenetic analysis based upon essentially full-length 16S rRNA gene sequences separates the two strains as distinct species within the fast-growing group of mycobacteria. Although both strains are thermosensitive, strain PYR-I has the bulged U between positions 184 and 193 characteristic of thermotolerant mycobacteria. Both strains are of potential use for reintroduction into and bioremediation of polycyclic aromatic hydrocarbon-contaminated soils.

Phylogenetic analysis of a bacterial aerobic degrader of azo dyes.

Eubacterial consensus oligonucleotide primers were used to amplify by polymerase chain reaction the nearly full-length 16S rRNA gene of isolate C7, a gram-negative rod capable of aerobic degradation of azo dyes. The DNA product was cloned and sequenced. Phylogenetic analysis based upon this DNA sequence places C7 within the alpha subdivision of proteobacteria, most closely related to Caulobacter subvibrioides. The phospholipid fatty acid pattern resembles that of caulobacters, with monounsaturated 16- and 18-carbon fatty acids predominating. C7 is unusual in having a monounsaturated branched fatty acid in the phospholipids and exclusively 2-hydroxy fatty acids in the lipid-extracted residue. This organism is of potential use in bioreactors operated for azo dye degradation.