Sequence conservation and distribution of the fusobacterial immunosuppressive protein gene,fipA

Fusobacterium nucleatum is a gram‐negative anaerobe involved in various diseases, including periodontitis. Recently, other investigators isolated the
F. nucleatum FDC 364 fusobacterial immunosuppressive protein (FIP). One subunit, FipA, impairs T‐cell activation in vitro and shows homology with beta‐ketothiolases. However, its distribution and variability among fusobacteria was not reported. Cloned fipA gene sequences from F. nucleatum ssp. polymorphum (ATCC 10953) and F. nucleatum ssp. nucleatum (ATCC 23726) shared 89 and 92% identity, respectively, with FDC 364 fipA, and 90 and 94% identity, respectively, with the FDC 364 FipA predicted amino acid sequence. Southern blot analyses of chromosomal DNA from fusobacterial strains, including
F. nucleatum and other Fusobacterium species, were performed using partial fipA sequences as probes. The results indicate that fipA is highly conserved among the F. nucleatum strains examined and that fipA homologues are widely distributed among fusobacteria. A clear relationship between immune suppression, metabolism and the FipA protein remains to be determined.     

A closer look at diagnosis in clinical dental practice: part 4. Effectiveness of nonradiographic diagnostic procedures and devices in dental practice

This article, the fourth in a series, examines nonradiographic procedures and devices such as standard clinical and visual examination, apex locators, vitality testers and colour shade guides in light of the tools described in the first 2 articles in the series. A variety of nonradiographic indices and scales are used in detecting periodontal disease and monitoring and assessing its treatment. The reliability of these diagnostic procedures directly affects treatment success, decisions to initiate more aggressive clinical interventions, and the ability to make an informed prognosis about the course of the disease. However, in many instances, the dependability of the measurements remains to be established.     

A closer look at diagnosis in clinical dental practice: part 2. Using predictive values and receiver operating characteristics in assessing diagnostic accuracy

When a clinician is planning to use a diagnostic test or procedure, it is important to establish the likelihood that an individual patient is affected by the condition or disease; this determination depends on predictions that are affected by various features of the diagnostic procedure. In this regard, sensitivity and specificity are limited because they describe the results of a procedure in a dichotomous way: the result is either positive or negative. However, many clinical procedures are not dichotomous, such as probing of periodontal pockets or assessment of radiographs for caries, and in these situations, a range of features is examined to produce a degree of certainty regarding the presence or absence of disease. This article examines predictive values and receiver operating characteristic (ROC) analysis, an algorithm that combines various statistical features of diagnostic procedures to assess the effectiveness of nondichotomous procedures without imposing an arbitrary threshold.     

Pyritinol reduces nociception and oxidative stress in diabetic rats

The purpose of this study was to assess the antinociceptive and antiallodynic effect of pyritinol as well as its possible mechanism of action in diabetic rats. Streptozotocin (50 mg/kg) injection caused hyperglycemia within 1 week. Formalin-evoked flinching was increased in diabetic rats as compared to non-diabetic rats. Oral acute administration of pyritinol (50-200 mg/kg) dose-dependently reduced flinching behavior in diabetic rats. Moreover, prolonged administration of pyritinol (12.5-50 mg/kg, every 2 days for 2 weeks) reduced formalin-induced nociception. 1H-[1,2,4]-oxadiazolo [4,3-a] quinoxalin-1-one (ODQ, a guanylyl cyclase inhibitor, 2 mg/kg, i.p.), but not naltrexone (a non-selective opioid receptor antagonist, 1 mg/kg, s.c.) or indomethacin (a non-selective cycloxygenase inhibitor, 5 mg/kg, i.p.), blocked the pyritinol-induced antinociception in diabetic rats. Given alone ODQ, naltrexone or indomethacin did not modify formalin-induced nociception in diabetic rats. Oral acute (200 mg/kg) or prolonged (25 mg/kg, every 2 days for 2 weeks) administration of pyritinol significantly reduced streptozotocin-induced changes in free carbonyls, dityrosine, malondialdehyde and advanced oxidative protein products. Four to 8 weeks after diabetes induction, tactile allodynia was observed in the streptozotocin-injected rats. On this condition, oral administration of pyritinol (50-200 mg/kg) reduced tactile allodynia in diabetic rats. Results indicate that pyritinol is able to reduce formalin-induced nociception and tactile allodynia in streptozotocin-injected rats. In addition, data suggest that activation of guanylyl cyclase and the scavenger properties of pyritinol, but not improvement in glucose levels, play an important role in these effects.     

Thiol peptides induction in the seagrass Thalassia testudinum (Banks ex König) in response to cadmium exposure

Trace metal accumulation and thiol compounds synthesis as induced by cadmium exposure was studied in the seagrass Thalassia testudinum. Shoots were exposed for 24, 48, 96 and 144 h to several CdCl(2) concentrations (0, 30, 50 and 70 microM). Levels of cadmium, cysteine, glutathione (GSH), gamma-glutamylcysteine (gamma-EC), and phytochelatin-like peptides were determined in green blades, live sheaths and root/rhizomes tissues. Metal accumulation was dependent on Cd concentration and type of tissue, with green blades showing the highest content followed by live sheaths and root/rhizomes. All tissues experienced an increase in thiol-containing compounds as a response to cadmium exposure. Live sheaths showed the highest levels of cysteine, GSH and gamma-EC. This is the first report of induction of thiol peptides, presumably phytochelatins, by a trace metal in a sea grass species.