Thiol/disulfide homeostasis in postmenopausal osteoporosis.

AIM: To evaluate the impact of postmenopausal osteoporosis on thiol/disulfide homeostasis. MATERIALS AND METHODS: A total of 75 participants were divided into two groups: Group 1 (n = 40) was composed of healthy postmenopausal women, and group 2 (n = 35) was composed of women with postmenopausal osteoporosis. Clinical findings and thiol/disulfide homeostasis were compared between the two groups. RESULTS: The disulfide/native thiol ratio was 8.6% ± 3.6 in group 1 and 12.7% ± 8.4 in group 2 (p = 0.04). The disulfide/native thiol percent ratio was significantly higher in group 2 after adjustment for the years since menopause and age (p < 0.05). The native thiol/total thiol percent ratio was 85.6% ± 4.8 in group 1 and 73.8% ± 24.9 in group 2 (p = 0.01). The native thiol/total thiol percent ratio was significantly lower in group 2 after adjustment for the years since menopause and age (p < 0.05). CONCLUSION: Thiol/disulfide homeostasis shifted to the disulfide side independent of age and years since menopause in postmenopausal osteoporosis.

Keratin-rhamnolipids and keratin-sodium dodecyl sulfate interactions at the air/water interface.

Keratin-surfactant interactions at the air/solution interface may be indicative for skin irritation by surfactants. In this study pure keratin was extracted from chicken feathers as described by Schrooyen at al. and the adsorption properties of biologically produced rhamnolipids (RL) and sodium dodecyl sulfate (SDS) mixed with keratin molecules were investigated by surface tension measurements. Keratin was added in three specific amounts to RL and SDS aqueous solutions of varying concentrations, respectively, and keratin-RL and keratin-SDS interactions were investigated at pH 6.2 and 5.0. The surface tension measurements showed that surfactant-keratin complexes were formed in the solutions at pH 6.2. At low RL concentrations the added amount of keratin decreased the surface tension as a result of the hydrophobic keratin-RL complexes formed, which have covered the air/solution interface. Beginning from moderate RL concentrations, less surface active keratin-RL complexes were formed due to hydrophilization of the former complexes and they were removed from the interface to the bulk phase as a result of the competitive adsorption mechanism and pure RL molecules covered the interface gradually. At low SDS concentrations surface tension decrease was also observed by the covering of the air/solution interface with keratin-SDS complexes. At moderate SDS concentrations the keratin-SDS complexes exhibited a more surface active feature. Unlike the keratin-RL complexes, they have remained at the interface until the higher SDS concentrations and keratin ratios. However, at the minimum surface tension value of the pure SDS at its CMC value, the surface tension of the keratin-SDS mixture reached the value of pure SDS solution and the air/solution interface has been covered again only with pure SDS monomers. The keratin-surfactant solutions prepared at pH 5 showed lower surface tension values compared to that measured at pH 6.2 and the surface tension behavior of RL and SDS resembled each other. Above a certain surfactant concentration the addition of keratin to surfactant solutions rendered the surface less surface active compared to their pure surfactant solutions at pH 5.0. The consideration of the surface tension behavior of two anionic surfactants has shown that the RL-keratin interactions are milder than SDS-keratin interactions at pH 6.2 and 5.0.

Lipid profile in chronic allograft nephropathy.

Chronic allograft nephropathy (CAN) represents the cumulative and incremental damage to nephrons by time-dependent immunologic and nonimmunologic causes. Hyperlipidemia is one nonimmunologic mechanism that promotes injury and poor function in a renal transplant. The aim of our study was to determine the effect of lipid profiles on CAN among renal transplant recipients. We retrospectively evaluated 53 renal transplant recipients who were classified according to the presence of CAN: CAN+ = 28 (18 males, 10 females) constituted the study group, whereas those with stable graft function CAN- = 25 (14 males, 11 females) were the control group. Biochemical parameters included serum urea, creatinine, total cholesterol, triglyceride, HDL cholesterol, LDL cholesterol, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), lipoprotein (a), homocysteine, and high-sensitive CRP (hs CRP). Angiotensin-converting enzyme inhibitor (ACEI) and/or angiotensin receptor blocker (ARB) use was significantly greater among the CAN+ group compared with the controls (P = .02, P = .04). Also, higher serum creatinine levels were observed in the CAN+ group (1.49 vs 1.22 mg/dL, P = .002), whereas serum levels of total cholesterol, triglyceride, hs CRP, and albumin were similar in both groups. The levels of ApoA1, ApoB, and lipoprotein (a) were similar, whereas the LDL/HDL cholesterol ratio and homocysteine levels were significantly higher in the CAN+ group (P = .04, P = .04). In conclusion, the LDL/HDL ratio may have a positive impact on CAN and may be used as a parameter during patient follow-up.

The estimation of the volume of sheep mandibular defects using cone-beam computed tomography images and a stereological method.

OBJECTIVE: The Cavalieri principle of stereological methods is widely used to estimate the volume of structures. Recently in clinical practice, it has become common to use this approach for daily routine purposes. The Cavalieri principle provides quantitative and unbiased volume estimates which are independent of the observer. In the present study, the efficacy of using the Cavalieri principle to estimate the volume of sheep mandibular defects on cone beam CT (CBCT) scans was tested. METHODS: 24 differently sized defects were created on 4 sheep mandibles. Before the defects were created, the outer boundaries of the defects were determined using plaster casts. CBCT scans of the defects were taken. The scans were reconstructed in the coronal plane and sections of 0.2 mm thickness with 0.2 mm and 0.4 mm intervals were obtained. The volume of each defect was estimated using the Cavalieri principle. The models were created using light-body silicone for the estimation of the actual volume of each defect. They were immersed in water using a pycnometer and the actual volumes were obtained on the basis of the Archimedean principle. The actual and estimated volumes of the defects were compared using the Wilcoxon signed-rank test. RESULTS: The results showed that the volumes from the Cavalieri estimates did not differ from the actual volumes of the defects (P > 0.05). CONCLUSION: We concluded that the volume of mandibular defects can be accurately estimated using the Cavalieri principle on images from a CBCT scan.

Helicobacter pylori-associated atrophic gastritis and carotid intima-media thickness: is there a link?

Chronic infections are associated with cardiovascular diseases. Helicobacter pylori-induced chronic active gastritis results in atrophic gastritis. In this study, we attempted to determine carotid intima-media thickness in patients with and individuals without H. pylori-induced atrophic gastritis. Oesophagogastroduodenoscopy was performed on 123 patients for various reasons. Helicobacter pylori were considered positive when histological examination and rapid urease test showed H. pylori. Helicobacter pylori-positive cases were divided into two groups, namely atrophic gastritis and non-atrophic gastritis. Of 123 patients, 92 patients had H. pylori-positive non-atrophic gastritis and 31 had H. pylori-positive atrophic gastritis. There was no significant difference in carotid intima-media thickness between the two groups. Carotid intima-media thickness is not associated with H. pylori-induced atrophic gastritis.

Sonographic findings in achalasia.

PURPOSE: The aim of this study was to describe the sonographic features of achalasia. METHODS: Thirty-five patients with achalasia (17 men and 18 women; mean age, 43 years) were examined with transabdominal sonography, and the findings were compared with those in 41 volunteers without esophageal disease (21 men and 20 women; mean age, 41 years), 10 patients with gastroesophageal junction carcinoma (7 men and 3 women; mean age, 55 years), and 4 patients with peptic stricture (3 men and 1 woman; mean age, 39 years). The distal end of the esophagus was evaluated, and the thickness of the esophageal wall was measured. RESULTS: In 28 fasting patients (80%) with achalasia, sonography showed dilatation, retention of fluid, and smooth narrowing of the distal esophagus (like a bird's beak). These findings were not identified in the other patients or volunteers. In addition, in 6 of 7 achalasia patients who had no sign of esophageal dilatation in the fasting state, water retention was demonstrated after ingestion of water, bringing the total number of patients with achalasia with positive sonographic findings to 34 (97%). In patients with achalasia, the mean thickness (+/- standard deviation) of the esophageal wall at the gastroesophageal junction was 4.8 +/- 0.9 mm (range, 3.6-7.2 mm). The thickening was regular, symmetric, and localized to the gastroesophageal junction. In the volunteers, the mean thickness of the esophageal wall was 2.3 +/- 0.5 mm (range, 1.4-3.5 mm). The difference between the 2 groups was statistically significant (p < 0.001). In the patients with carcinoma, the mean wall thickness was 17.0 /+ 1.1 mm, and the thickening was irregular. In the patients with peptic stricture, the mean wall thickness was 5.1 +/- 1.1 mm (range, 3.8-8.3 mm), and the thickening was irregular and occupied a longer segment of the distal esophagus. CONCLUSIONS: In patients with achalasia, transabdominal sonography clearly shows the regular thickening of the esophageal wall, water retention, dilatation of the distal esophagus, and the bird's beak appearance. Sonography may help in differentiating achalasia from carcinoma and peptic stricture of the gastroesophageal junction, which is difficult to do with other modalities.

Retroperitoneal duodenal perforation during endoscopic sphincterotomy: sonographic findings.

We present the sonographic findings in 5 cases of retroperitoneal duodenal perforation during endoscopic sphincterotomy. In each case, sonography showed hyperechoic areas associated with shadowing and ring-down artifacts between the liver and the right kidney correlating with the retroperitoneal air seen on plain x-ray films. This brightly echogenic area with shadowing surrounded and obscured the kidney. In 4 patients, resolution was documented on follow-up sonographic examinations in agreement with other radiologic findings; the other patient died.

Portal vein aneurysm in hereditary hemorrhagic telangiectasia.

Both hereditary hemorrhagic telangiectasia (HHT) and portal vein aneurysm are rare disorders. We described the first documented case of HHT associated with portal vein aneurysm. As the portal vein aneurysm in this patient associated with HHT, the pathogenesis in this patient seems to have been a congenital anomaly of the vasculature.

Sonographic diagnosis of recurrent ulcer penetrating the anterior abdominal wall.

Penetration of a recurrent ulcer into the anterior abdominal wall after surgical treatment of peptic ulcer disease is a rare surgical emergency. Early diagnosis is essential, but there are no specific radiographic or endoscopic features. We report 2 cases of recurrent ulcer penetration into the anterior abdominal wall diagnosed preoperatively with transabdominal sonography. The ulcers appeared as cavity lesions, with hyperechoic bases that had destroyed the continuity of the stomach wall. Associated findings were a minimal amount of fluid around the ulcer cavity and a hypoechoic area considered secondary to inflammation or edema. The diagnoses were confirmed at laparotomy.

Endoscopic management of a duodenal duplication cyst associated with biliary obstruction in an adult.

Duodenal duplication cysts are distinctly uncommon and most often present in infancy or early childhood. The clinical presentation is generally duodenal obstruction, hemorrhage, or pancreatitis. Duodenal duplication cysts rarely cause biliary obstruction in adults. So far, duodenal duplication cysts have been almost exclusively treated by surgical intervention. This report describes both endoscopic diagnosis and treatment of a large periampullary duodenal duplication cyst associated with biliary obstruction in an adult patient.

Chronic pancreatitis and aortic pseudoaneurysm in Behçet's disease.

Behçet's disease is a chronic, recurrent, systemic disease characterized by orogenital ulcers and oculocutaneous inflammatory lesions. Cardiovascular, pulmonary, neurological, articular, and GI involvement are common features, but pancreatic involvement is very rare. We present a case of Behçet's disease with both chronic pancreatitis and abdominal aorta pseudoaneurysm.

YSDD: a novel mutation in HBV DNA polymerase confers clinical resistance to lamivudine.

The emergence of drug-resistant virus in hepatitis B virus (HBV) patients treated with lamivudine is well documented. In this study, we determined the mutations occurring in the tyrosine-methionine-aspartate-aspartate (YMDD) amino acid motif of the HBV DNA polymerase gene, as well as upstream and downstream of this region, in patients with breakthrough virus during lamivudine therapy. Thirty-one Turkish patients (20 patients HBeAg positive, 11 patients HBeAg negative and anti-HBe positive) with chronic HBV infection who completed at least 104 weeks of lamivudine treatment were investigated. All patients received lamivudine, (150 mg/day), for 104 weeks, with or without 4 months of interferon (IFN) combination. HBV-specific sequences were amplified by polymerase chain reaction (PCR) from sera of patients with breakthrough virus, and the PCR products were directly analysed by sequencing. Breakthrough virus was detected in seven of the 31 patients (22.6%) between 9 and 18 months of therapy. Of the seven patients, six were HBeAg positive at baseline, and four had a double mutation consisting of rtM204V and rtL180M, while two had an rtM204I change. In one patient, two base substitutions at rt204 (ATG --> AGT; T to G and G to T) lead to a methionine to serine change (YMDD --> YSDD). This novel DNA pol mutation was detected at month 18 of lamivudine treatment. In addition, this new variant had the rtL180M mutation and a 12 base pair deletion in the pre-S1 region between nucleotides 43-54. The YSDD mutation was still present 6 months after lamivudine discontinuation. In vitro transfection studies also confirmed that the YSDD strain is resistant to lamivudine. In conclusion, the results indicate that, in addition to a Met --> Val and Met --> Ile change in YMDD, a Met --> Ser change at rt204 (YMDD --> YSDD) associated with the rtL180M change can also emerge during lamivudine treatment, which confers lamivudine resistance in vivo and in vitro, leading to virological breakthrough and ALT increases.