Evaluation of periodontal pathogens of the mandibular third molar pericoronitis by using real time PCR.

OBJECTIVES: The aim of this study was to investigate the mandibular third molar pericoronitis flora by using real-time polymerase chain reaction (PCR). MATERIALS AND METHODS: The quantitative values of Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi) and Tannerella forsythia (Tf) were evaluated in comparison with the healthy third molar flora by using real time PCR. RESULTS: Aa, Cr, Pg, and Pi were not statistically significant but numerically higher than the pericoronitis group. In contrast to samples from control subjects, statistically significant higher numbers of Tf were detected in samples from pericoronitis patients. The study revealed the strong relation between risk of pericoronitis and the presence of Tf. Individuals who have Tf in their samples present with an almost eight times relative risk of pericoronitis as the individuals with an absence of Tf in their samples. CONCLUSION: Tf plays an important role in the development of clinical symptoms related to pericoronitis.

Long-term exposure to repetitive hyperbaric oxygen results in cumulative oxidative stress in rat lung tissue.

CONTEXT: Despite its known benefits, hyperbaric oxygen (HBO) is also reported to enhance the production of reactive oxygen species and can cause oxidative stress in several tissues. Previous studies had shown that HBO-induced oxidative stress is directly proportional to both its exposure pressure and duration. Nevertheless, these studies were usually performed with single-session HBO exposure but its clinical use commonly depends on long-term exposure periods. OBJECTIVE: To clarify the oxidative effect of long-term repetitive HBO in the lung tissue of rats. MATERIALS AND METHODS: Male Sprague-Dawley rats were divided into six study groups exposed to consecutive HBO sessions (2.8 atm/90 min) for 5, 10, 15, 20, 30, and 40 days. Animals were sacrificed 24 h after the last HBO session. An additional control group was set to obtain normal data. Lung malondialdehyde (MDA) and carbonylated protein (PCC) levels were determined as measures of oxidative stress along with the activities of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase. RESULTS: None of the measured parameters showed any changes among the groups exposed to 5-15 HBO sessions. However, MDA, PCC, and SOD were found to be significantly increased in the 20 to 40 session groups. DISCUSSION AND CONCLUSION: These results indicate that repetitive treatment with HBO may cause oxidative stress in critical tissues including the lung. Although HBO-mediated free radicals are accepted to be responsible for the benefits of this therapeutic modality, especially in cases with prolonged exposure, possible injurious effects of supranormal values of bio-oxidative products need to be considered.

Soluble vascular endothelial growth factor receptor 1 in human breast milk.

BACKGROUND/AIMS: Vascular endothelial growth factor (VEGF) is a potent proangiogenic protein that activates VEGF receptor (VEGFR-1, VEGFR-2) tyrosine kinases expressed by vascular endothelial cells. A soluble truncated form of VEGFR-1 (sVEGFR-1) binds to VEGF as strongly as full-length VEGFR-1 and inhibits VEGF activity. sVEGFR-1 can be detected in mouse and human plasma but in human milk sVEGFR-1 has not been described previously. METHODS: We measured sVEGFR-1 and VEGF in human milk and examined how the concentration varied with gestational age and the duration of lactation after birth. Human milk samples were collected from 29 mothers of preterm (<37 weeks) and from 29 mothers of term (>38 weeks) infants at days 3, 7 and 28 postpartum. RESULTS: The sVEGFR-1 and VEGF concentrations were greater in the human milk of mothers of preterm compared to term neonates (p < 0.05). Furthermore, the concentrations of sVEGFR-1 and VEGF were decreasing during postpartum days 3, 7 and 28. The concentration of sVEGFR-1 showed a positive correlation with the concentration of VEGF in human milk (r = 0.479 and p < 0.001). CONCLUSION: sVEGFR-1 is present in human milk and has a role in angiogenesis.