Higher sensitivity of female cells to ethanol: methylation of DNA lowers Cyp2e1, generating more ROS.

BACKGROUND: Cells taken from mouse embryos before sex differentiation respond to insults according to their chromosomal sex, a difference traceable to differential methylation. We evaluated the mechanism for this difference in the controlled situation of their response to ethanol. METHODS: We evaluated the expression of mRNA for alcohol dehydrogenase (ADH), aldehyde dehyrogenases (ALDH), and a cytochrome P450 isoenzyme (Cyp2e1) in male and female mice, comparing the expressions to toxicity under several experimental conditions evaluating redox and other states. RESULTS: Females are more sensitive to ethanol. Disulfiram, which inhibits alcohol dehydrogenase (ADH), increases cell death in males, eliminating the sex dimorphism. The expressions ADH Class 1 to 4 and ALDH Class 1 and 2 do not differ by sex. However, females express approximately 8X more message for Cyp2e1, an enzyme in the non-canonical pathway. Female cells produce approximately 15% more ROS (reactive oxygen species) than male cells, but male cells contain approximately double the concentration of GSH, a ROS scavenger. Scavenging ROS with N-acetyl cysteine reduces cell death and eliminates sex dimorphism. Finally, since many of the differences in gene expression derive from methylation of DNA, we exposed cells to the methyltransferase inhibitor 5-aza- 2-deoxycytidine; blocking methylation eliminates both the difference in expression of Cyp2e1 and cell death. CONCLUSION: We conclude that the sex-differential cell death caused by ethanol derives from sex dimorphic methylation of Cyp2e1 gene, resulting in generation of more ROS.

The Role of Fibular Fixation in the Treatment of Combined Distal Tibia and Fibula Fracture: A Randomized, Control Trial.

BACKGROUND: This randomized, parallel-group, non-blinded study was designed to determine the role of fibular fixation in the treatment outcomes of combined distal tibia and fibula fractures. MATERIALS AND METHODS: Sixty patients with distal tibial and fibular fractures were randomly divided in two groups of case and controls. In the case group, fibula was fixed prior to the fixation of tibia. In the control group, tibia was fixed without fibular fixation. Primary outcomes were varus-valgus angulation, anterior-posterior angulation, union and side effects. Follow-up visit and radiographs were taken 2 and 4 weeks as well as 3, 6 and 9 months after surgery. RESULTS: During the follow-up, 11 out of 60 patients in case and control groups were excluded. We recruited 24 and 25 patients in the case and control group, respectively. Intramedullary nailing was used in 8 patients of case and 11 patients of control group. Plate and screw were used in 16 patients in the case and 14 patients in the control group. Varus/valgus and anterior-posterior angulation were not statistically significant between two groups (P ≥ 0.05). The frequency of tibial and fibula union after 1, 3, 6 and 9 months in case and controls groups were not statistically significant (P ≥ 0.05). The frequency of nonunion of tibia and fibula, infection and nerve injury in studied groups were not statistically significant (P ≥ 0.05). CONCLUSION: We did not observe any significant improvement using fibular fixation in the treatment outcomes of tibia distal fractures.

A case report of osteochondroma with unusual clinical and imaging presentation.

Osteochondroma or exostosis is a bony developmental anomaly, which arises from exophytic outgrowth on bone surfaces in a characteristic manner. Osteochondroma is asymptomatic and grows away from the nearby joint. This paper reports an unusual presentation of osteochondroma in which the patient was surprisingly completely symptomatic. The lesion grew toward the nearby joint and the radiographic findings were not compatible with surgical findings.

Results of pronator quadratus repair in distal radius fractures to prevent tendon ruptures.

BACKGROUND: Distal radius fractures are one of the the most common adult fractures encountered during the clinical practice of an orthopedic surgeon.12 Although several methods of treatment are suggested for these fractures, there are still controversies about the best treatment approach in the literature. Volar plating of distal radius fracture is a method of treatment which has become increasingly popular. One of the complications of this technique is flexor tendon rupture. The purpose of this study was to evaluate the protectiveness of complete repair of pronator quadratus muscle against flexor tendon rupture. MATERIALS AND METHODS: From September 2010 to September 2012, a consecutive series of 157 patients who were younger than 60 years with unstable distal radius fractures were included in the study. A standard volar approach to the distal radius was carried out. The radial and distal ends of pronator quadratus muscle were meticulously elevated from the radius and after volar plate fixation of the fracture, pronator quadratus muscle was restored to its normal insertion. We achieved full coverage of the plate with this muscle and followed the patients postoperatively. RESULTS: A total of 135 patients were studied. The mean age of patients was 34 ± 10 years (range 20-60 years). One 55-year-old diabetic female patient with flexor tendon rupture was identified. The flexor pollicis longus tendon had ruptured 16 months after surgery. CONCLUSIONS: Pronator quadratus repair should be done in distal radius fracture to protect flexor tendons.

Evaluation the treatment outcomes of intracapsular femoral neck fractures with closed or open reduction and internal fixation by screw in 18-50-year-old patients in Isfahan from Nov 2010 to Nov 2011.

BACKGROUND: There is conflict of interest in the treatment of intracapsular femoral neck fractures and the outcomes. The aim of this study was evaluation the treatment outcomes of closed and open reduction and internal fixation with screw in 18-50-year-old patients. MATERIALS AND METHODS: This clinical randomized study was conducted in Ayatollah Kashani Center in Isfahan from Nov 2010 to Nov 2011. In 42 patients selected in a randomized manner, fractures were reduced by closed reduction or open if necessary and C-ARM was controlled in AP and lateral plans. Movement range and femur pain severity were evaluated according to Visual analogue Scale (VAS) score at 3 and 6 months after surgery. Data were analyzed by SPSS 18. Chi-square, t-test, one-way analysis of variance (ANOVA), and descriptive statistics such as frequency distribution, mean, and mean deviation were used. RESULTS: Forty-two patients with femoral neck fracture were treated by open [31 patients (73.8%)] or closed reduction [11 patients (26.2%)] and also osteosynthesis. Their mean age was 47.3 ± 9.8 years; 29 of them were males and 13 were females. Twelve patients had bad range of motion (ROM) (28.6%), 16 had intermediate ROM (38%), and 14 had good ROM (33.4%). After 6 months, 12 patients (28.6%) had bad ROM, 10 (23.8%) had intermediate ROM, and 20 (47.6%) had good ROM. There were 11 cases of non-union (35.5%) in the open reduction group and 4 in the closed group. CONCLUSION: This study showed that femoral neck fracture is associated with several complications, especially if open reduction was necessary. So, the surgical method and necessary equipments such as radiolucent bed, C-ARM machine, and implant cannulated screw set should be considered.

Fibro-osseous pseudotumor of the digit.

Fibro-osseous pseudotumor of the digit is an unusual ossifying soft tissue lesion, which is usually an ill-defined soft tissue mass in radiography, with focal calcification, especially in the proximal phalanx. It predominantly affects young adults and, unlike myositis ossificans, is more common in women. The current case is a 30-year-old man who presented with pain and swelling on the dorsum of middle phalanx of the left index finger without history of trauma. Diagnosis of this lesion requires a high index of suspicion and should be differentiated from myositis ossificans, turret exostosis, and extra-skeletal osteosarcoma, which are discussed. This lesion is considered benign and has an excellent prognosis following complete removal and local recurrence is unusual. No cases of malignant change are on record.

Unicameral bone cyst of the scaphoid: a report of two cases.

Unicameral bone cysts are benign, fluid-filled lesions that occur mostly in long bones (proximal humerus, 50-60%; femur, 30%) of male children aged 5 to 15 years. Occurrence in the scaphoid of an adult is rare. We report 2 such patients who presented with wrist pain, with and without a history of trauma. Both underwent curettage and bone grafting (harvested from the distal radius) and achieved good functional recovery.

Inhibition of high-mobility group box 1 protein (HMGB1) enhances bacterial clearance and protects against Pseudomonas Aeruginosa pneumonia in cystic fibrosis.

Pulmonary infection with Pseudomonas aeruginosa and neutrophilic lung inflammation significantly contribute to morbidity and mortality in cystic fibrosis (CF). High-mobility group box 1 protein (HMGB1), a ubiquitous DNA binding protein that promotes inflammatory tissue injury, is significantly elevated in CF sputum. However, its mechanistic and potential therapeutic implications in CF were previously unknown. We found that HMGB1 levels were significantly elevated in bronchoalveolar lavage fluids (BALs) of CF patients and cystic fibrosis transmembrane conductance regulator (CFTR )(-/-) mice. Neutralizing anti-HMGB1 monoclonal antibody (mAb) conferred significant protection against P. aeruginosa-induced neutrophil recruitment, lung injury and bacterial infection in both CFTR(-/-) and wild-type mice. Alveolar macrophages isolated from mice treated with anti-HMGB1 mAb had improved phagocytic activity, which was suppressed by direct exposure to HMGB1. In addition, BAL from CF patients significantly impaired macrophage phagocytotic function, and this impairment was attenuated by HMGB1-neutralizing antibodies. The HMGB1-mediated suppression of bacterial phagocytosis was attenuated in macrophages lacking toll-like receptor (TLR)-4, suggesting a critical role for TLR4 in signaling HMGB1-mediated macrophage dysfunction. These studies demonstrate that the elevated levels of HMGB1 in CF airways are critical for neutrophil recruitment and persistent presence of P. aeruginosa in the lung. Thus, HMGB1 may provide a therapeutic target for reducing bacterial infection and lung inflammation in CF.

Th17 and non-Th17 interleukin-17-expressing cells in chronic lymphocytic leukemia: delineation, distribution, and clinical relevance.

BACKGROUND: The levels and clinical relevance of Th17 cells and other interleukin-17-producing cells have not been analyzed in chronic lymphocytic leukemia. The objective of this study was to quantify blood and tissue levels of Th17 and other interleukin-17-producing cells in patients with this disease and correlate blood levels with clinical outcome. DESIGN AND METHODS: Intracellular interleukin-17A was assessed in blood and splenic mononuclear cells from patients with chronic lymphocytic leukemia and healthy subjects using flow cytometry. Interleukin-17A-producing cells were analyzed in formalin-fixed, paraffin-embedded spleen and lymph node sections using immunohistochemistry and immunofluorescence. RESULTS: The absolute numbers of Th17 cells in peripheral blood mononuclear cells and the percentages of Th17 cells in spleen cell suspensions were higher in patients with chronic lymphocytic leukemia than in healthy subjects; in six out of eight paired chronic lymphocytic leukemia blood and spleen sample comparisons, Th17 cells were enriched in spleen suspensions. Circulating Th17 levels correlated with better prognostic markers and longer overall survival of the patients. Two "non-Th17" interleukin-17-expressing cells were identified in chronic lymphocytic leukemia spleens: proliferating cells of the granulocytic lineage and mature mast cells. Granulocytes and mast cells in normal spleens did not express interleukin-17. Conversely, both chronic lymphocytic leukemia and healthy lymph nodes contained similar numbers of interleukin-17+ mast cells as well as Th17 cells. CONCLUSIONS: Th17 cells are elevated in chronic lymphocytic leukemia patients with better prognostic markers and correlate with longer survival. Furthermore, non-Th17 interleukin-17A-expressing cells exist in chronic lymphocytic leukemia spleens as maturing granulocytes and mature mast cells, suggesting that the microenvironmental milieu in leukemic spleens promotes the recruitment and/or expansion of Th17 and other IL-17-expressing cells. The pathophysiology of Th17 and non-Th17-interleukin-producing cells in chronic lymphocytic leukemia and their distributions and roles in this disease merit further study.

Administration of human umbilical cord blood cells produces interleukin-10 (IL-10) in IL-10 deficient mice without immunosuppression.

Recent studies from our laboratory have shown that intravenous administration of human umbilical cord blood (HUCB) mononuclear cells to mice improved blood glucose levels, survival, atherosclerosis and prostate cancer. In this study, we examined the effect of HUCB cells on the production of IL-10 levels in IL-10 knockout mice. It has been proposed that administration of IL-10 may be beneficial in the treatment of inflammatory bowl disease. The results show that mice treated with HUCB cells (100 x 10(6)) produce IL-10, as demonstrated by both qualitative and quantitative analyses, and that the levels of this cytokine persisted until the mice were sacrificed (5.5 months after administration). Immunohistochemical staining of the intestine using HuNu antibody cocktail demonstrated the presence of HUCB cells in the knockout mouse. Although the mice did not receive any immunosuppression, there was no evidence of graft-versus-host disease. Our data suggest that HUCB cells are capable of producing IL-10, and the use of these cells or HUCB may be indicated in the treatment of certain human diseases.

Nicotinic acetylcholine receptor expression and regulation in the rat kidney after ischemia-reperfusion injury.

The cholinergic anti-inflammatory pathway is a mechanism whereby local inflammation is modulated by the brain via the vagus nerve and nicotinic acetylcholine receptors (nAChRs). The nAChR family are ligand-gated ion channels that consist of many different subtypes formed by the specific assembly of five polypeptide subunits including alpha1-10, beta1-4, gamma, delta, and epsilon. The alpha7 receptor (alpha7nAChR) mediates the anti-inflammatory effects of cholinergic stimulation. We recently demonstrated that cholinergic agonists attenuate renal ischemia-reperfusion (I/R) injury in rats. We also showed that tubular epithelial cells express functional nAChRs in vitro. The current studies report the expression, localization, and regulation of the alpha7nAChR in the rat kidney after I/R injury. We also examined, in this model, potential interactions between cholinergic stimulation and the STAT3 pathway, a key signaling cascade that has been linked to alpha7nAChR activation. RT-PCR and immunohistochemistry showed constitutive expression of many nAChR subunits. Immunohistochemistry localized basal alpha7nAChR expression to the endothelium of cortical peritubular capillaries, and its distribution was upregulated after I/R injury. Western blotting also showed an increase in alpha7nAChR subunit protein after renal I/R injury. Interestingly, pretreatment with nicotine, which improves the outcome after renal I/R injury, reduced the alpha7nAChR protein after I/R injury. Finally, we found that I/R injury stimulated the STAT3 pathway, whereas pretreatment with nicotine downregulated its activation. These results suggest that the alpha7nAChR plays an important role in the pathophysiology of renal I/R injury.

Hyperoxia-induced signal transduction pathways in pulmonary epithelial cells.

Mechanical ventilation with hyperoxia is necessary to treat critically ill patients. However, prolonged exposure to hyperoxia leads to the generation of excessive reactive oxygen species (ROS), which can cause acute inflammatory lung injury. One of the major effects of hyperoxia is the injury and death of pulmonary epithelium, which is accompanied by increased levels of pulmonary proinflammatory cytokines and excessive leukocyte infiltration. A thorough understanding of the signaling pathways leading to pulmonary epithelial cell injury/death may provide some insights into the pathogenesis of hyperoxia-induced acute inflammatory lung injury. This review focuses on epithelial responses to hyperoxia and some of the major factors regulating pathways to epithelial cell injury/death, and proinflammatory responses on exposure to hyperoxia. We discuss in detail some of the most interesting players, such as NF-kappaB, that can modulate both proinflammatory responses and cell injury/death of lung epithelial cells. A better appreciation for the functions of these factors will no doubt help us to delineate the pathways to hyperoxic cell death and proinflammatory responses.

Antioxidants preserve macrophage phagocytosis of Pseudomonas aeruginosa during hyperoxia.

Pseudomonas. aeruginosa (PA) is a leading cause of nosocomial pneumonia in patients receiving mechanical ventilation with hyperoxia. Exposure to supraphysiological concentrations of reactive oxygen species during hyperoxia may result in macrophage damage that reduces their ability to phagocytose PA. We tested this hypothesis in cultured macrophage-like RAW 264.7 cells and alveolar macrophages from mice exposed to hyperoxia. Exposure to hyperoxia induced a similarly impaired phagocytosis of both the mucoid and the nonmucoid forms of PA in alveolar macrophages and RAW cells. Compromised PA phagocytosis was associated with cytoskeleton disorganization and actin oxidation in hyperoxic macrophages. To test whether moderate concentrations of O(2) limit the loss of phagocytic function induced by > or =95% O(2), mice and RAW cells were exposed to 65% O(2). Interestingly, although the resulting lung injury/cell proliferation was not significant, exposure to 65% O(2) resulted in a marked reduction in PA phagocytosis that was comparable to that of > or =95% O(2). Treatment with antioxidants, even post hyperoxic exposure, preserved actin cytoskeleton organization and phagocytosis of PA. These data suggest that hyperoxia reduces macrophage phagocytosis through effects on actin functions which can be preserved by antioxidant treatment. In addition, administration of moderate rather than higher concentrations of O2 does not improve macrophage phagocytosis of PA.