Comparison of apical debris extrusion of different generation nickel-titanium instrument systems.

Background and Aim: The aim of this study is to evaluate the apical debris extrusion amounts and preparation times of four different nickel-titanium systems with a similar cross-section design-Mtwo, RECIPROC, RECIPROC blue, and VDW.ROTATE. Materials and Methods: Eighty human mandibular central incisors were divided into four equal groups (n = 20). The test apparatus was inserted into an assembly that provided root canal temperature. Preparation times were recorded using a stopwatch, and the amount of extruded debris was collected in pre-weighed Eppendorf tubes. After drying, the net amount was determined by subtracting the previously measured Eppendorf tube weights from the total weight. Results: The Mtwo had the largest amount of debris, but there was no significant difference among the other groups. The VDW.ROTATE completed the preparation in a significantly shorter time than the RECIPROC blue and Mtwo. Conclusion: Compared to other files, the Mtwo sequence produced significantly more debris and required significantly more time to complete the whole root canal preparation.

Comparison of the cyclic fatigue resistance of hyflex EDM, vortex blue, protaper gold, and onecurve nickel-Titanium instruments.

OBJECTIVE: This in vitro study aimed to compare the cyclic fatigue resistance of HyFlex EDM (HEDM), Vortex Blue (VB), ProTaper Gold (PG), and OneCurve (OC) nickel-titanium (NiTi) instruments. MATERIALS AND METHODS: About 12 HEDM (25/.~), 12 VB (25/.06), 12 PG (25/.08), and 12°C (25/.06) instruments were included in this study. All the instruments were tested with a 60° angle of curvature and a 3-mm radius of curvature. All the instruments were utilized until fracture occurred, and then the number of cycles to failure (NCF) was calculated. The data were analyzed statistically using Kruskal-Wallis H and Mann-Whitney U-tests. The statistical significance level was set at P < 0.05. RESULTS: HEDM instruments had the highest cyclic fatigue resistance among all the other instruments (P < 0.05). The OC instruments had a significantly higher fatigue resistance than the PG and VB instruments (P < 0.05); however, there was no significant difference between PG and VB instruments in the NCF (P > 0.05). CONCLUSION: Within the limitations of this in vitro study, it was found that the cyclic fatigue resistance was higher for the HEDM instruments than for the VB, PG, and OC instruments.

The Effect of the iNOS Inhibitor S-Methylisothiourea and Hyperbaric Oxygen Treatment on Radiation Colitis in Rats.

INTRODUCTION: External radiotherapy is one of the main treatment modalities for a variety of malignancies. However, the lower gastrointestinal tract is sensitive to the ionizing radiation. Hyperbaric oxygen treatment (HOT) has been suggested as a viable treatment for refractory radiation colitis, but the effect of S-Methylisothiourea (SMT) in the radiation colitis have not reported. To investigate the effect of SMT, HOT and the combination of both in an acute radiation-induced enterocolitis model. METHODS: Sixty Sprague-Dawley rats were divided randomly into five equal groups. A single dose of gamma irradiation (25 Gy) was administered through the colorectal region to anesthetized rats. In the control group, we applied 2 ml of saline solution intraperitoneally for five days. In the HOT group, 100-per-cent oxygen at 2.5 atm pressure was applied for five days. In the SMT group, 10 mg/kg/day of SMT was applied intraperitoneally for five days. In the HOT+SMT group, HOT and SMT were both applied in the same dosages as in the preceding two groups. At the end of five days, the rats were sacrificed and colon samples were collected for histological grading. Blood samples were collected to test for : tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), IL-1ß, transforming growth factor-ß (TGF-ß) and intercellular adhesion molecule-1 (ICAM-1) mRNA. RESULTS: The TNF-α, IL-1ß, IL-10 and TGF-ß levels were reduced by SMT, HOT and HOT+SMT applications (p < 0.05). However ICAM-1 mRNA levels were not significantly lower (p:0.19). The microscopic scores differed significantly between the SMT, HOT and HOT+SMT groups and the control group. There was significant improvement histologically, especially in the HOT+SMT group. When we compared the weight of the rats before and after the study, weight loss was significantly lower in the SMT, HOT and HOT+SMT groups compared with the control group (p < 0.05). CONCLUSION: HOT and SMT together were significantly more effective in preventing weight loss and in reducing inflammation and the severity of colitis histology when compared with HOT and SMT separately.

Variations in cyclic fatigue resistance among ProTaper Gold, ProTaper Next and ProTaper Universal instruments at different levels.

AIM: To compare the cyclic fatigue resistance of ProTaper Gold (PTG, Dentsply Tulsa Dental Specialities, Tulsa, OK, USA), ProTaper Next (PTN, Dentsply Tulsa Dental Specialities) and ProTaper Universal (PTU, Dentsply Tulsa Dental Specialities) instruments at different levels. METHODOLOGY: A total of 72 files were used to evaluate the cyclic fatigue of PTU (F2), PTN (X2) and PTG (F2) at 5 mm (n = 12) and 8 mm (n = 12) from the tip in 3-mm-radius steel canals with a 60° angle of curvature. The time to fracture was recorded. The Kolmogorov-Smirnov test was used to assess the normality of the samples distribution, and the statistical analysis was performed using the independent sample t-test (P < 0.01). RESULTS: Significant differences were found amongst the instruments 5 mm from the tip (P < 0.01). The PTG files had the highest CF resistance, and the PTN files displayed greater CF resistance than the PTU files. No significant differences were found between the PTG and PTN files 8 mm from the tip (P > 0.01). The PTG and PTN files demonstrated greater CF resistance than the PTU files (P < 0.01). CONCLUSIONS: The PTG instruments were the most resistant 5 and 8 mm from the tip; however, at 8 mm, there was no difference between the PTG and PTN instruments. The PTU files had the lowest CF resistance at all levels.

Efficiency of rifampicin in emergency treatment of severe hyperbilirubinemia : report of two cases and review of literature.

We showed in this study that rifampicin therapy is more effective than plasmapheresis and steroid treatment in diseases associated with severe hyperbilirubinemia. In our opinion, rifampicin treatment may suitable especially for patients with persistent hyperbilirubinemia, and it would be appropriate to use rifampicin as a challenge therapy to patients with severe hyperbilirubinemia, but liver function tests in these patients must be monitored closely.

Evaluation of orange-brown precipitate formed in root canals after irrigation with chlorhexidine and QMix and spectroscopic analysis of precipitates produced by a mixture of chlorhexidine/NaOCl and QMix/NaOCl.

AIMS: (i) To compare chlorhexidine and QMix(TM) in terms of orange-brown precipitate generation in root canals and (ii) to analyse the precipitate produced by mixing chlorhexidine and QMix(™) with NaOCl to determine whether para-chloroaniline was produced. METHODOLOGY: The root canals of 57 single-rooted anterior teeth were prepared using ProTaper Universal rotary instruments up to size F4. Two millilitres of 2.5% NaOCl was used between each instrument change. The specimens were then divided randomly into three groups (n = 19) and irrigated as follows: group 1, 5 mL of distilled water (control group) for 60 s; group 2, 5 mL of 2% chlorhexidine for 60 s; and group 3, 5 mL of QMix for 60 s. The roots were split longitudinally, and one of the halves was photographed using a stereomicroscope. The amount of orange-brown precipitate was evaluated using a four-grade scoring system. The data were analysed statistically using the Kruskal-Wallis and Mann-Whitney U-tests (P = 0.05). To evaluate whether the precipitates included para-chloroaniline, 5 mL of 2% chlorhexidine and 5 mL QMix were separately mixed with 5 mL of 2.5% NaOCl in two flasks. After centrifugation, precipitates were obtained and analysed using (1) H NMR spectra. The data were subjected to statistical analysis using the Kruskal-Wallis and Mann-Whitney tests at a 95% confidence level (P = 0.05). RESULTS: Chlorhexidine had significantly higher scores than QMix(™) in terms of orange-brown precipitate formed in the root canals (P < 0.001). According to the 1H NMR spectra, para-chloroaniline was present in the mixture of chlorhexidine and NaOCl. However, the mixture of QMix(™) and NaOCl did not result in para-chloroaniline formation. CONCLUSION: QMix(™) does not form para-chloroaniline when associated with NaOCl.

Frequency of hepatitis G virus and transfusion-transmitted virus infection in type II diabetes mellitus.

The hepatitis G virus (HGV) and transfusion-transmitted virus (TTV) are recently defined hepatitis viruses that the pathogenic roles in liver diseases are still not clear. It has been well known that some hepatitis virus, such as hepatitis C, might have an affinity to pancreatic islet cells. To investigate the relationship between the newly defined hepatitis viruses and diabetes mellitus (DM), we studied the prevalence of TTV and HGV in a type 2 diabetic patient population. Serum samples of 60 patients with DM and 45 healthy volunteers as control were taken. HGV RNA and TTV DNA was investigated by polymerase chain reaction. HGV was detected in none of diabetic patients (0%) and only one in control group (2.2%). However, TTV DNA was detected in 16 patients with DM (26%) and in five controls (11%). TTV was more prevalent in diabetic patients, but the difference between groups was not statistically significant (p > 0.05). These results revealed that TTV is more common in diabetic patients than in controls. At present, we don't know if this result is only a coincidence or a sign of potential association between TTV and DM. Further studies are certainly needed to elucidate a potential relationship.

Metformin in the treatment of patients with non-alcoholic steatohepatitis.

BACKGROUND: Increased insulin resistance is the major pathogenic mechanism in the development of non-alcoholic steatohepatitis. AIM: To investigate the therapeutic effect of metformin, a well-known insulin-sensitizing agent, in the treatment of non-alcoholic steatohepatitis. METHODS: Thirty-six patients with non-alcoholic steatohepatitis were randomized into two groups. The first group was given lipid and calorie-restricted dietary treatment alone, and the second group was given metformin 850 mg b.d. plus dietary treatment, for 6 months. The changes in biochemical, sonographic and histological parameters were compared. RESULTS: The mean serum alanine/aspartate aminotransferase, insulin and C-peptide levels decreased and the index of insulin resistance improved significantly from baseline in the group given metformin. The mean changes in these parameters in the metformin group were significantly greater than those in the group given dietary treatment alone. Although more patients in the metformin group showed improvement in the necro-inflammatory activity, compared with the group given dietary treatment alone, no significant differences in necro-inflammatory activity or fibrosis were seen between the groups. CONCLUSION: The data suggest that improvement of the insulin sensitivity with metformin may improve the liver disease in patients with non-alcoholic steatohepatitis.

Similar frequency of TT virus infection in patients with liver enzyme elevations and healthy subjects.

TT virus (TTV) is a novel DNA virus that has been identified in patients with post-transfusional hepatitis of unknown aetiology. However, its pathogenic role in liver injury remains unclear. To determine its frequency and clinical impact in cryptogenic liver diseases, we investigated the TTV prevalence in patients with liver enzyme elevations of unknown aetiology and in healthy subjects. Fifty-four patients (33 male, 21 female) who have been followed up for elevated ALT/AST levels of unknown aetiology and 118 healthy subjects (99 male and 19 female) were included in the study. TTV DNA was investigated by the polymerase chain reaction. Other possible causes of transaminase elevation were excluded in detailed biochemical and serological tests. A liver biopsy was performed in 45 patients. TTV DNA was detected in 46 patients with liver enzyme elevations (85.1%) and in 94 healthy subjects (79.6%). There was no statistical difference between the groups (p = 0.51). Histological examination of the liver revealed no specific change in TTV DNA positive patients that could be attributed to this virus infection. These results showed that TTV is a common virus in patients with liver enzyme elevation of unknown aetiology and even among healthy subjects in our geographical area. TTV infection is therefore widespread in the general population and does not seem to be associated with liver damage.

Rifampicin test in the diagnosis of Gilbert's syndrome.

Gilbert's syndrome (GS) is characterised by the existence of chronic mild unconjugated hyperbilirubinaemia. The value of rifampicin as a provocative test for the diagnosis of GS was evaluated and compared with a fasting test. Twenty-two patients with GS, 15 patients with chronic liver disease and 20 healthy controls were included. Both rifampicin and fasting tests were applied to all subjects. In the fasting test, the subjects were given a 400 calorie/day diet for 24 hours; in the rifampicin test, unconjugated bilirubin levels was measured before and four hours after taking 600 mg of rifampicin. Both tests achieved a significant increase in mean unconjugated bilirubin levels in patients with GS but not in the controls. The sensitivity and specificity of a rifampicin test in the diagnosis of GS were comparable with the fasting test. However, both tests caused a significant increase in unconjugated bilirubin levels in nearly half the patients with chronic liver disease. A rifampicin test may be used in the diagnosis of suspected GS instead of a fasting test, as it is simpler and more practical. However, its specificity for GS is not sufficient, because it also causes an increase in unconjugated bilirubin levels in some patients with chronic liver disease.

Insignificant role of hepatitis G virus infection in patients with liver enzyme elevations of unknown etiology.

Hepatitis G virus (HGV) may cause acute and chronic infection in humans but its role in parenchymal liver injury and chronic hepatitis is obscure. In this study, the importance of HGV was investigated in patients with elevated aminotransferases alanine transaminase/aspartate transaminase (ALT/AST) levels of unknown etiology. We included 56 patients with elevated ALT/ AST levels of unknown etiology and 81 healthy controls in the study. HGV RNA was investigated by the reverse transcription polymerase chain reaction. The other possible causes of transaminase elevation were excluded with detailed biochemical and serologic tests. Liver biopsy was performed on 47 patients for histologic examination. HGV RNA was detected in only two patients (3.3%) and in one control (1.2%). There was no statistical difference between the groups. Liver biopsy revealed minimal inflammatory changes and steatosis in HGV RNA-positive patients. These observations indicated that HGV prevalence is not different from that of the general population in patients with liver transaminases elevation of unknown etiology. The role of this novel virus in the pathogenesis of chronic liver injury of unknown etiology appears insignificant in our geographic area.

Influence of viral load and alanine aminotransferase on viral genetic heterogeneity in patients with chronic hepatitis C virus infection.

BACKGROUND/AIM: Hepatitis C virus (HCV) populations in vivo consist of genetically different heterogeneous mixtures defined as 'quasispecies', which vary in the hypervariable region 1 (HVR1) mostly. To further address the role of quasispecies diversity in hepatitis C infection, this study aimed to evaluate the influence of ALT, viral load and genotypes on quasispecies heterogeneity in patients with HCV infection. METHODS: Thirty-six chronic hepatitis C patients with high levels of alanine aminotransferase (ALT) were studied. None of them received any antiviral therapy. HCV RNA serum levels, genotype and genetic heterogeneity were determined by branched-chain DNA assay, restriction fragment length patterns and RT-PCR single-strand conformational polymorphism analysis of HVR1, respectively. RESULTS: Twenty-eight patients had genotype 1b (28/36; 78%), 6 patients had genotype 1a (6/36; 17%), 1 patient was 2a (1/36; 3%) and genotype could not be determined in 1 patient. The patients were categorized into two groups according to the number of bands representing the dominant strains in the circulation: group A with 2 bands having 1 strain (14/36 patients; 39%) and group B with more than 2 bands indicating more than 1 strain (22/36 patients; 61%). The serum viremia and ALT levels for these groups were 11 +/- 8.8 and 5.3 +/- 4.6 mEq/ml (p < 0.05), and 79 +/- 20, and 127 +/- 80 IU/l (p < 0.05), respectively. CONCLUSION: The results of this study suggest that hepatitis C patients having 1 dominant strain in the circulation may show a relatively weaker immune response resulting in lower ALT and higher viremia levels, whereas patients with high degrees of virus quasispecies diversity have higher ALT levels and a more active immune response causing the selection of new genome variants and depressing viral replication partly.

Serum leptin levels in patients with nonalcoholic steatohepatitis.

OBJECTIVE: Leptin is a peptide hormone that mainly regulates food intake and energy expenditure of human body. A close correlation between serum leptin levels and the percentage of body fat stores is well known. Nonalcoholic steatohepatitis (NASH) is a common disorder which causes serum liver enzyme elevation. In this study, the serum leptin levels were investigated in patients with NASH to determine a possible role in the pathogenesis and in patients with chronic viral hepatitis to ascertain the effect of hepatic inflammation on serum leptin level. METHODS: Forty-nine patients (38 men, 11 women) with NASH diagnosed by biopsy, 32 patients with biopsy-proven chronic viral hepatitis (21 men and 11 women), and 30 healthy adults (17 men, 13 women) enrolled in the study. Fasting blood samples were obtained, and serum leptin levels were measured by ELISA. Body mass index (BMI) was calculated for all subjects, and serum insulin, C-peptide, and lipoprotein levels were also detected. RESULTS: The mean serum leptin levels (+/-SEM) were 6.62 +/- 0.71, 4.24 +/- 1.0, and 4.02 +/- 0.46 ng/ml in NASH, chronic hepatitis, and the control group, respectively. Mean serum leptin level in the NASH group was significantly higher than those in the other groups tested. BMI was also slightly higher in the NASH group when compared to the other groups (26.7 +/- 0.3, 23.7 +/- 0.6, and 24.6 +/- 0.3, respectively). There was a significant correlation between BMI and serum leptin levels when all the subjects were evaluated together (NASH, hepatitis, and control groups, r = 0.337, p = 0.012) but not in the NASH group when evaluated alone (r = 0.238, p = 0.1). Of the predisposing factors for NASH, obesity was observed in 24% of patients and hyperlipidemia in 67%. Serum cholesterol and triglyceride levels were significantly higher in the NASH group than those in controls (p < 0.05). It has been detected that most of these patients consumed high amounts of fat in their dietary habits. CONCLUSIONS: The serum leptin levels were significantly higher in patients with NASH, while they were not affected by chronic hepatitis. This elevation is out of proportion to BMI of these patients and may be related to hyperlipidemia in most. Elevated serum leptin levels, therefore, may promote hepatic steatosis and steatohepatitis.

Interferon treatment for thrombocytopenia associated with chronic HCV infection.

Thrombocytopenia is commonly seen in patients with chronic liver disease, due mainly to hypersplenism secondary to portal hypertension. We report a case of chronic hepatitis C admitted with thrombocytopenia of unknown cause. The patient s symptoms and platelet count improved markedly with interferon treatment. We conclude that interferon treatment in chronic C hepatitis may improve HCV-induced thrombocytopenia.

The effect of Helicobacter pylori eradication on duodenal gastric metaplasia.

We investigated the incidence of duodenal gastric metaplasia and its response to Helicobacter pylori eradication in patients with duodenal ulcer or erosive duodenitis. Gastric and duodenal biopsies were taken from patients with endoscopically detected H. pylori positive duodenal ulcer or erosive duodenitis, and the presence and extent of duodenal gastric metaplasia was recorded. Patients were given omeprazole 20 mg twice daily for 2 weeks, and amoxicillin 1 g and clarithromycin 500 mg twice daily for 10 days, and then ranitidine for a further 8 weeks. Biopsies were repeated 6 months after the start of treatment. Duodenal gastric metaplasia was initially present in 22 patients (52%) and was more frequent in ulcer patients than in duodenitis patients, but not significantly so (69% versus 45%). After treatment, H. pylori was eradicated in 68% of duodenal gastric metaplasia patients and the duodenum was normal endoscopically in 85% of these patients. Duodenal gastric metaplasia was improved or eliminated in 12/15 H. pylori eradicators (80%) and in 5/7 H. pylori non-eradicators (71%), a non-significant difference. The improvement in duodenal gastric metaplasia appeared to be independent of H. pylori eradication.

Efficacy of omeprazole plus two antimicrobials for the eradication of Helicobacter pylori in a Turkish population.

Omeprazole combined with 2 antimicrobials has been suggested as a first-line option for Helicobacter pylori eradication in recent years. However, controversy exists regarding the efficacy of this protocol. This open-label, prospective clinical study investigated the efficacy of omeprazole-based triple therapy for H pylori eradication in 518 patients with H pylori-positive functional dyspepsia with or without duodenal ulcer. Amoxicillin, macrolides (clarithromycin or roxithromycin), and nitroimidazoles (metronidazole, ornidazole, or tinidazole) were the antibiotics used in the study. Nonulcer patients were randomly assigned to 1 of 8 different treatment protocols and duodenal ulcer patients were randomly assigned to 1 of 4 different treatment protocols consisting of omeprazole (20 mg once daily for nonulcer patients, 20 mg twice daily for ulcer patients for 14 days) with a combination of 2 of the above antimicrobials (for 10 days). H pylori infection was assessed by histologic findings and a rapid urease test before therapy and 4 weeks after therapy ended. Four hundred fifty-nine patients completed their regimens; 327 had functional dyspepsia (180 men, 147 women; median age, 39 years; range, 18 to 70 years) and 132 had ulcers (81 men, 51 women; median age, 40 years; range, 18 to 70 years). Eradication of H pylori was achieved in 58.8% (270 of 459) of all patients, 58.1% (190 of 327) of nonulcer dyspeptic patients, and 60.6% (80 of 132) of duodenal ulcer patients. The eradication rate varied from 47.2% to 69.4% in different treatment protocols. There were no statistically significant differences in eradication rates in any treatment group. All drugs were generally well tolerated in all groups, and no patient discontinued treatment because of side effects. Therapy with omeprazole and 2 antimicrobials for H pylori had limited efficacy in a Turkish population. The reason for these results, which conflict with those of other studies, is not clear. Further investigations of regimens for the eradication of H pylori in our population are necessary.