Polymer-Based Bioactive Luting Agents for Cementation of All-Ceramic Crowns: An SEM, EDX, Microleakage, Fracture Strength, and Color Stability Study.

The aim of the study was to compare microleakage and fracture loads of all ceramic crowns luted with conventional polymer resins and polymeric bioactive cements and to assess the color stability of polymeric bioactive cements. Seventy-five extracted premolar teeth were tested for fracture loads and microleakage in all-ceramic crowns cemented with two types of polymeric bioactive cements and resin cements. In addition, the degree of color change for each cement with coffee was assessed. Thirty maxillary premolar teeth for fracture loads and thirty mandibular premolar teeth for microleakage were prepared; standardized teeth preparations were performed by a single experienced operator. All prepared specimens were randomly distributed to three groups (n = 20) based on the type of cement, Group 1: resin cement (Multilink N); Group 2: polymeric bioactive cement (ACTIVA); Group 3: polymeric bioactive cement (Ceramir). The cementation procedures for all cements (Multilink, ACTIVA, and Ceramir) were performed according to the manufacturers' instructions. All specimens were aged using thermocycling for 30,000 cycles (5-55 °C, dwell time 30 s). These specimens were tested using the universal testing machine for fracture strength and with a micro-CT for microleakage. For the color stability evaluation, the cement specimens were immersed in coffee and evaluated with a spectrometer. Results: The highest and lowest means for fracture loads were observed in resin cements (49.5 ± 8.85) and Ceramir (39.8 ± 9.16), respectively. Ceramir (2.563 ± 0.71) showed the highest microleakage compared to resin (0.70 ± 0.75) and ACTIVA (0.61 ± 0.56). ACTIVA cements showed comparable fracture loads, microleakage, and stain resistance compared to resin cements.

Growth-Based, High-Throughput Selection for NADH Preference in an Oxygen-Dependent Biocatalyst.

Cyclohexanone monooxygenases (CHMO) consume molecular oxygen and NADPH to catalyze the valuable oxidation of cyclic ketones. However, CHMO usage is restricted by poor stability and stringent specificity for NADPH. Efforts to engineer CHMO have been limited by the sensitivity of the enzyme to perturbations in conformational dynamics and long-range interactions that cannot be predicted. We demonstrate an aerobic, high-throughput growth selection platform in Escherichia coli for oxygenase evolution based on NADH redox balance. We applied this NADH-dependent selection to alter the cofactor specificity of CHMO to accept NADH, a less expensive cofactor than NADPH. We first identified the variant CHMO DTNP (S208D-K326T-K349N-L143P) with a ∼1200-fold relative cofactor specificity switch from NADPH to NADH compared to the wild type through semirational design. Molecular modeling suggests CHMO DTNP activity is driven by cooperative fine-tuning of cofactor contacts. Additional evolution of CHMO DTNP through random mutagenesis yielded the variant CHMO DTNPY with a ∼2900-fold relative specificity switch compared to the wild type afforded by an additional distal mutation, H163Y. These results highlight the difficulty in engineering functionally innovative variants from static models and rational designs, and the need for high throughput selection methods. Our introduced tools for oxygenase engineering accelerate the advancements of characteristics essential for industrial feasibility.

Clinical Outcomes of Lithium Disilicate Single Crowns after a Mean Duration of 3 Years - A Retrospective Study.

PURPOSE: To investigate the clinical performance and clinical survival rate of lithium disilicate-based core ceramic (IPS e.max Press) utilised in single crowns and to the accompanying periodontal health status. MATERIALS AND METHODS: A total of 47 patients with 88 IPS e.max Press single crowns were examined at the Faculty of Dentistry, University of Malaya, using modified United States Public Health Service evaluation criteria (USPHS). These 88 crowned teeth included 19 vital and 69 nonvital teeth that were restored with different post and core materials. The periodontal status was compared using the plaque index (PI), gingival recession (GR), modified papillary bleeding index (MPBI) and probing pocket depth (PPD) between the crowned teeth and contralateral control (sound) teeth. RESULTS: About 96.6% of the crowns exhibited satisfactory clinical performance. The mean survival rate at three years was 97.7%, and 100% at two years with a low incidence of fractures. There were no staitistically significant differences in the mean gingival recession (p = 0.182) and mean plaque scores (p = 0.102) between crowned and control teeth. The crowned teeth had higher mean MPBI (p = 0.000) and PPD (p = 0.051) compared to the contralateral sound teeth. Periodontal response in relation to subgingival crown margins, was statistically significantly lower regarding pocket depths (p = 0.01) and bleeding on probing (p = 0.00). CONCLUSION: IPS e.max Press crowns exhibited satisfactory clinical performance with high survival rate. No dentinal sensitivity was recorded. Plaque retention and gingival recession were similar to contralateral control teeth. Poor periodontal health was related to the subgingival crown margins.

Outcome of HIV-associated Pneumocystis pneumonia in hospitalized patients from 2000 through 2003.

BACKGROUND: Pneumocystis pneumonia (PCP) remains a leading cause of morbidity and mortality in HIV-infected persons. Epidemiology of PCP in the recent era of highly active antiretroviral therapy (HAART) is not well known and the impact of HAART on outcome of PCP has been debated. AIM: To determine the epidemiology of PCP in HIV-infected patients and examine the impact of HAART on PCP outcome. METHODS: We performed a retrospective cohort study of 262 patients diagnosed with PCP between January 2000 and December 2003 at a county hospital at an academic medical center. Death while in the hospital was the main outcome measure. Multivariate modeling was performed to determine predictors of mortality. RESULTS: Overall hospital mortality was 11.6%. Mortality in patients requiring intensive care was 29.0%. The need for mechanical ventilation, development of a pneumothorax, and low serum albumin were independent predictors of increased mortality. One hundred and seven patients received HAART before hospitalization and 16 patients were started on HAART while in the hospital. HAART use either before or during hospitalization was not associated with mortality. CONCLUSION: Overall hospital mortality and mortality predictors are similar to those reported earlier in the HAART era. PCP diagnoses in HAART users likely represented failing HAART regimens or non-compliance with HAART.

Effectiveness of infliximab in treating selected patients with sarcoidosis.

OBJECTIVE: To assess the effectiveness of infliximab (Remicade) in the treatment of patients with sarcoidosis who either do not respond to corticosteroids and other conventional drugs or develop unacceptable side effects to these drugs. DESIGN: A clinical, non-randomized, off-label study. SETTING: Sarcoidosis clinic at a university teaching hospital. PATIENTS: Twelve biopsy-proven sarcoidosis patients, nine women and three men ranging from 45 to 70 years of age with chronic multisystem sarcoidosis refractory to corticosteroids or alternative treatment. INTERVENTION: Infliximab was infused at a dedicated ambulatory infusion center. The initial dose was 3mg/kg body weight and subsequent doses were given at weeks 2, 4, 6, 10, and 14. All patients received at least six infusions. RESULTS: All 12 patients improved significantly. One patient had a mild allergic drug reaction that responded to antihistamine. One patient, after 3 months of stopping infliximab treatment, died of a ruptured blood vessel in the abdomen. At autopsy a plasma cell dyscrasia was found. CONCLUSION: Infliximab is safe and effective in treating those patients with multisystem sarcoidosis who are either refractory or develop side effects to a standard regimen of corticosteroids and immunosuppressive agents.

Sarcoidosis of the spinal cord: literature review and report of eight cases.

Sarcoidosis, which affects African Americans more than it does other racial/ethnic groups, only rarely manifests initially as spinal cord dysfunction. This paper presents the findings of eight patients with spinal cord dysfunction as part of a presentation of sarcoidosis. After reviewing these cases, we devised an algorithm to diagnose and manage spinal cord sarcoidosis.

Epstein-Barr-virus-induced interstitial lung disease.

PURPOSE OF REVIEW: We describe a patient in whom Epstein-Barr virus infection appears to have caused an unusual interstitial lung disease with multisystem involvement resembling sarcoidosis and interstitial lung disease. We have reviewed the relevant literature about the relation of Epstein-Barr virus and interstitial lung disease. RECENT FINDINGS: Epstein-Barr virus replication within type II alveolar cells was shown to occur in adult cryptogenic fibrosing alveolitis. Latent membrane protein 1 is one of the Epstein-Barr-virus-associated proteins and is expressed on the surface of Epstein-Barr-virus-infected cells in the latent and replicating phases. Latent membrane protein 1 was positive in the cuboidal epithelial cells of the lungs from some patients with idiopathic pulmonary fibrosis, and that its positivity correlated with poor prognosis. Epstein-Barr virus was also found in the lungs of children with lymphocytic interstitial pneumonia, AIDS and Langerhans cell histiocytosis. Epstein-Barr virus DNA was not detectable in patients with sarcoidosis. There was also lack of evidence for a role of Epstein-Barr virus in the increase of lung cancer in idiopathic pulmonary fibrosis. SUMMARY: Using monoclonal antibodies against viral antigen Epstein-Barr virus was shown to replicate within type II alveolar cells of adult idiopathic pulmonary fibrosis patients. Latent membrane protein 1positivity indicates poor prognosis; Epstein-Barr virus positivity did not increase the incidence of lung cancer in these patients. Epstein-Barr virus was also associated with lymphocytic interstitial pneumonia, AIDS and Langerhans cell histiocytosis but not with sarcoidosis.

Interferon-induced granulomatous lung disease.

PURPOSE OF REVIEW: Interferon therapy can induce or exacerbate sarcoidosis. With the increasing use of interferons it is highly likely that more cases of sarcoidosis will be encountered by clinicians. We describe three unusual cases of interferon-induced sarcoidosis and review the most recent relevant literature on this subject. RECENT FINDINGS: Interferons, on account of their antiviral antigrowth and immunomodulatory effects, are used to treat various internal and dermatological diseases. Exogenously administered interferons stimulate the Th-1 response, which plays a major role in granuloma formation. In most of the patients with interferon-induced sarcoidosis, the disease subsides when interferon is discontinued. Occasionally, treatment with corticosteroids may become necessary. SUMMARY: Interferon therapy can induce or exacerbate sarcoidosis, the disease disappears when interferon is discontinued, sometimes treatment with corticosteroids is required.