Titanium as a Reconstruction and Implant Material in Dentistry: Advantages and Pitfalls

Commercial pure titanium (cpTi) has been the material of choice in several disciplines of dentistry due to its biocompatibility, resistance to corrosion and mechanical properties. Despite a number of favorable characteristics, cpTi as a reconstruction and oral implant material has several shortcomings. This paper highlights current knowledge on material properties, passive oxidation film formation, corrosion, surface activation, cell interactions, biofilm development, allergy, casting and machining properties of cpTi for better understanding and potential improvement of this material for its clinical applications.     

Long‐Term Exposure to Biomass Fuel and Its Relation to Systolic and Diastolic Biventricular Performance in Addition to Obstructive and Restrictive Lung Diseases

Background: Previous studies have demonstrated an increased risk for cardiovascular events and pulmonary disease in patients with biomass fuel exposure (BFE). However, biventricular heart function has yet to be investigated in these patients. Left ventricular (LV) myocardial performance index (LVMPI), which is an index of global ventricular function, incorporates ejection, isovolumic relaxation, and contraction times. In this study, pulmonary function and biventricular heart function were investigated in nonsmoking female patients with BFE. Methods: Our study population consisted of 46 female patients with BFE (group 1) and 31 control subjects (group 2). Pulmonary function tests and transthoracic echocardiographic examination were performed. Right ventricular myocardial performance index (RVMPI) and LVMPI were obtained by tissue Doppler imaging echocardiography (TDI). Results: BFE caused obstructive and restrictive spirometric impairments. RVMPI was higher in group 1 (0.55 ± 0.07) than group 2 (0.46 ± 0.06) (P = 0.042) and LVMPI was higher in group 1 (0.54 ± 0.08) than group 2 (0.47 ± 0.05) (P = 0.032). Also, pulmonary artery systolic pressure was higher in group 1 than group 2 (P = 0.02). Conclusions: BFE causes both obstructive and/or restrictive lung disease and systolic and diastolic biventricular dysfunction. Nonetheless, long‐term studies are needed to understand on BFE‐related ventricular dysfunctions and to document subsequent cardiovascular events. (Echocardiography 2011;28:52‐61)     

Successful and sustained treatment of chronic radiation proctitis with antioxidant vitamins E and C

OBJECTIVE: Chronic radiation proctitis, a common sequelae of pelvic radiation, is characterized by obliteration of the submucosal vasculature with subsequent ischemia and reperfusion injury. Oxidative stress is thought to be a major mechanism in radiation proctitis. Therefore, antioxidants (vitamins E and C) may be beneficial. METHODS: Twenty consecutive symptomatic outpatients with endoscopically documented radiation proctitis seen in a single gastroenterology clinic were given a combination of vitamin E (400 IU tid) and vitamin C (500 mg tid). Previous radiation therapy was given for prostatic (n = 10) or gynecological (n = 10) malignancies. These patients presented with one or more of the following symptoms: rectal bleeding, rectal pain, diarrhea, or fecal urgency. Using a questionnaire, these symptoms were rated by the patients in terms of their severity (grade 0-4) and frequency (grade 0-4) before and after treatment with vitamins E and C. A symptom index was calculated by the addition of the severity and frequency scores (8 = most symptomatic). The lifestyle impact of the symptoms was also assessed by questionnaire grading from 0 (no effect on daily activity) to 4 (afraid to leave home). Among these 20 patients, 10 patients who received vitamins E and C for 1 yr were assessed again to determine whether their initial responses were sustained. RESULTS: There was a significant (p < 0.05; Wilcoxon rank) improvement in the symptom index (before treatment vs after treatment with vitamins E and C) for bleeding (median score: 4 vs 0), diarrhea (median score: 5 vs 0), and urgency (median score: 6 vs 3). Patients with rectal pain did not improve significantly. Bleeding resolved in four of 11 patients, diarrhea resolved in eight of 16 patients, fecal urgency resolved in three of 16 patients, and rectal pain resolved in two of six patients. Lifestyle improved in 13 patients, including seven patients who reported a return to normal. Two of the patients with no improvement in their daily symptoms also had radiation ileitis. All 10 patients who underwent a second follow-up interview reported sustained improvement in their symptoms 1 yr later. CONCLUSION: A substantial number of patients with radiation proctitis seem to benefit from antioxidant therapy. A double-blind placebo-controlled trial is needed to confirm this open-labeled pilot study.     

Endoscopy in eosinophilic esophagitis: "feline" esophagus and perforation risk.

BACKGROUND & AIMS: Idiopathic eosinophilic esophagitis is an underdiagnosed disease with typical endoscopic findings, which have not been well described. METHODS: Charts and pathology reports at two tertiary care centers from June 1993 to April 2002 were reviewed to describe the endoscopic findings of this disease and to correlate them with clinical characteristics. Eight patients were identified as having eosinophilic esophagitis based on clinical symptoms and pathology reports. RESULTS: Soft and subtle ring(s) in the esophagus were found in 7 of 8 patients. In 3 of 8 patients, the esophagus appeared rigid. Mucosal rents occurred with simple passage of the endoscope in 5 of 8 patients. One patient developed a perforation after simple passage of the endoscope. Endoscopic findings can be normal or very subtle in these patients, and the findings can easily be missed during endoscopy. Tearing of the esophagus can occur with simple passage of the endoscope or biopsy even in the absence of overt rings. A minimum of 8 weeks of medical therapy (proton pump inhibitor, histamine antagonists, immunosuppressants) should be undertaken before considering dilation because of the high risk involved with the procedure and the good response to medical therapy. CONCLUSIONS: We recommend considering dilation only in patients with eosinophilic esophagitis who do not respond to medical therapy and have rings that appear to be obstructing the lumen.     

Upregulation of alveolar epithelial active Na+ transport is dependent on beta2-adrenergic receptor signaling

Alveolar epithelial beta-adrenergic receptor (betaAR) activation accelerates active Na+ transport in lung epithelial cells in vitro and speeds alveolar edema resolution in human lung tissue and normal and injured animal lungs. Whether these receptors are essential for alveolar fluid clearance (AFC) or if other mechanisms are sufficient to regulate active transport is unknown. In this study, we report that mice with no beta1- or beta2-adrenergic receptors (beta1AR-/-/beta2AR-/-) have reduced distal lung Na,K-ATPase function and diminished basal and amiloride-sensitive AFC. Total lung water content in these animals was not different from wild-type controls, suggesting that betaAR signaling may not be required for alveolar fluid homeostasis in uninjured lungs. Comparison of isoproterenol-sensitive AFC in mice with beta1- but not beta2-adrenergic receptors to beta1AR-/-/beta2AR-/- mice indicates that the beta2AR mediates the bulk of beta-adrenergic-sensitive alveolar active Na+ transport. To test the necessity of betaAR signaling in acute lung injury, beta1AR-/-/beta2AR-/-, beta1AR+/+/beta2AR-/-, and beta1AR+/+/beta2AR+/+ mice were exposed to 100% oxygen for up to 204 hours. beta1AR-/-/beta2AR-/- and beta1AR+/+/beta2AR-/- mice had more lung water and worse survival from this form of acute lung injury than wild-type controls. Adenoviral-mediated rescue of beta2-adrenergic receptor (beta2AR) function into the alveolar epithelium of beta1AR-/-/beta2AR-/- and beta1AR+/+/beta2AR-/- mice normalized distal lung beta2AR function, alveolar epithelial active Na+ transport, and survival from hyperoxia. These findings indicate that betaAR signaling may not be necessary for basal AFC, and that beta2AR is essential for the adaptive physiological response needed to clear excess fluid from the alveolar airspace of normal and injured lungs.     

Decreased Plasminogen Activator Inhibitor-1 Levels in Coronary Artery Aneurysmatic Patients

BACKGROUND: Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of arterial aneurysms through increased proteolysis of extracellular matrix proteins. Increased proteolysis due to elevated matrix degrading enzyme activity in the arterial wall may act as a susceptibility factor for the development of coronary aneurysms. Plasmin strongly stimulates pro-MMP enzyme conversion to the active form. Plasmin hyperactivity due to decreased plasminogen activator inhibitor-1 (PAI-1) may cause MMP over activity and coronary aneurysms. The aim of this study was to investigate the association between PAI-1 and presence of coronary aneurysms. METHODS: Twenty-three patients with aneurysmal coronary artery disease and stable angina were enrolled into study (Group 1). Twenty-two patients without coronary aneurysm were selected as a control group (Group 2). PAI-1 was measured in peripheral venous blood. RESULTS: The plasma PAI-1 level was lower in the coronary artery aneurysmatic patients compared to the control group (8.41 +/- 4.28 vs. 13.32 +/- 10.05 ng/ml, p = 0.037). Serum C-reactive protein (CRP) values were not significantly different between groups (3.83 +/- 1.08 vs. 4.01 +/- 1.35 mg/l, p >0.05). CONCLUSION: Increased matrix degrading enzyme activity can cause arterial wall destruction through increased proteolysis of extracellular matrix proteins. Unregulated plasmin hyperactivity due to decreased inhibition by PAI-1 may play an important role in coronary aneurysm formation.     

The cognitive aspect of formal thought disorder and its relationship with global social functioning and the quality of life in schizophrenia

Purpose

It was expected that using a comprehensive scale like the Thought and Language Disorder Scale (TALD) for measurement of FTD would enable assessing its heterogeneity and its associations with cognitive impairment and functionality. This study has aimed to analyze the relationship between formal thought disorder (FTD) and cognitive functions, functionality, and quality of life in schizophrenia.

Methods

This cross-sectional exploratory study included 46 clinical participants meeting the DSM-5 diagnostic criteria for schizophrenia and 35 healthy individuals as the control groups. Data were acquired by means of the Turkish language version of the TALD, the Positive and Negative Syndrome Scale, the Clinical Global Impression Scale, the Functioning Assessment Short Test, the Social Functioning Scale, the World Health Organization Quality of Life Instrument-Short Form, and a neuropsychological test battery on executive functions, working memory, verbal fluency, abstract thinking, and response inhibition. Correlation analyses were conducted to detect significant relationships.

Results

The clinical group scored failures in all cognitive tests. The objective positive FTD was associated with deficits in executive functions and social functioning. The objective negative FTD was associated with poor performance in all cognitive domains, physical quality of life, and social and global functioning. The subjective negative FTD was negatively correlated with psychological quality of life.

Conclusion

This study demonstrated that objective FTD factors reflect different underlying cognitive deficits and correlate with different functioning domains. Significant correlation was determined between subjective negative FTD and psychological quality of life. Given the close relationship of FTD with functioning and quality of life, the FTD-related cognitive deficits should be the key treatment goal in schizophrenia.