Risk of empyema in patients with end-stage renal disease: a nationwide propensity-matched cohort study.

BACKGROUND: Empyema is a rare but important complication among patients with end-stage renal disease (ESRD). However, a nationwide, propensity-matched cohort study has never been performed. METHODS: We conducted a retrospective cohort study using data from the National Health Insurance Research Database of Taiwan. The ESRD group consisted of 82 765 patients diagnosed between 2000 and 2008. The comparison group consisted of individuals without kidney disease selected at a 1:1 ratio matched by propensity score estimated with age, gender, year of diagnosis and comorbidities. The occurrence of empyema was monitored until the end of 2011. The hazard ratios (HRs) of empyema were estimated using the Cox proportional hazards model. RESULTS: The incidence of empyema was 2.76-fold higher in the ESRD group than in the comparison group (23.7 vs. 8.19/10 000 person-years, P <0.001), with an adjusted HR of 3.01 [95% confidence interval (CI) = 2.67-3.39]. There was no difference of the incidence of empyema between hemodialysis (HD) and peritoneal dialysis (PD) (adjusted HR = 0.96, 95% CI = 0.75-1.23). In addition, 30-day mortality rate since empyema diagnosis was significantly higher in ESRD group than the comparison group (15.9% vs. 10.9%), with an adjusted OR of 1.69 (95% CI = 1.17-2.44). CONCLUSION: The risk of empyema was significantly higher in patients with ESRD than in those without kidney disease. The occurrence of empyema was without difference in patients undergoing HD compared to those undergoing PD. The 30-day mortality rate since empyema diagnosis was also significantly higher in patients with ESRD.

Increased risk of chronic obstructive pulmonary disease in patients with rheumatoid arthritis: a population-based cohort study.

BACKGROUND: The role of autoimmune pathology in development and progression of chronic obstructive pulmonary disease (COPD) is becoming increasingly popular. Our aim was to assess the association between patients with rheumatoid arthritis (RA) and subsequent COPD risk in a nationwide population. METHOD: We conducted a retrospective cohort study using data from the National Health Insurance system of Taiwan. The RA cohort included patients who were newly diagnosed and recruited between 1998 and 2008. Each patient was randomly frequency-matched for age, sex and the year of index date with people without RA from the general population. The newly diagnosed COPD was followed up until the end of 2010. The relative risks of COPD were estimated using Cox proportional hazard models after adjusting for age, sex, index year and comorbidities. RESULT: The overall incidence rate of COPD was 1.74-fold higher in the RA cohort than in the non-RA cohort (5.25 vs. 3.01 per 1000 person-years, 95% confidence interval (CI) = 1.68-1.81). Age-related risk analysis showed an increased incidence of COPD with age in both RA and non-RA cohorts. However, adjusted hazard ratio (HR) maximum was witnessed in the age range of 20-34 years (adjusted HR: 7.67, 95% CI=1.94-30.3), whereas adjusted HR minimum was observed in the oldest age group (>65 years). CONCLUSION: Patients with RA have a significantly higher risk of developing COPD than that of the control population. Further, age-related risk analysis indicated much higher adjusted HR in younger patients although COPD incidence increased with age. It can be hypothesized that in addition to cigarette smoke, RA may be a determining factor for COPD incidence and/or facilitates shortening of the time course for developing COPD. However, further investigation is needed to corroborate this hypothesis.

The use of different implant modalities in the atrophied ridge.

Many implant practitioners have been taught to use one implant system by a specific manufacturer. However, to successfully treat a patient, implant clinicians must learn to utilize the strengths of various systems when the patient's condition warrants it. The purpose of this paper is to illustrate how an edentulous patient with atrophied bone was treated with multiple-model implant procedures. Her treatment included different root form implants, bone spreading augmentations, endosseous submerged blades, tricortical support Diskimplants, and a custom-made ramus blade implant.

Effect of reduced pyridine nucleotides and tungstate on the in vitro insertion of molybdenum into demolybdo-nitrate reductase of Chlorella vulgaris.

Demolybdo-nitrate reductase (cytochrome c reductase) (NADH: acceptor oxidoreductase, EC 1.6.99.3) of Chlorella vulgaris can be activated in vitro to nitrate reductase by insertion of Mo from molybdate into the apoprotein. Evidence is here presented that reduction of the enzyme by reduced pyridine nucleotides inhibits the process of molybdenum insertion. This report also describes the effect of molybdate and tungstate concentration on the activation process. The activation is sigmoidally related to molybdate concentration with a calculated Hill coefficient of NH = 3. At suboptimal molybdate concentrations, tungstate stimulates enzyme activation by molybdate; but at saturating molybdate concentrations, tungstate is inhibitory. These facts are regarded as an indication that molybdate and tungstate are both positive effectors of molybdenum incorporation, but that they are competitors for the active Mo center.

Molybdenum insertion in vitro in demolybdo nitrate reductase of Chlorella vulgaris.

Demolybdo nitrate reductase (also called cyt c reductase) of Chlorella vulgaris has been converted to active nitrate reductase by insertion of Mo from Na2MoO4 in vitro. A procedure is described which consistently gives about 0.3 unit of nitrate reductase from about 6 units of cyt c reductase, a yield of 30% of the maximum expected, if we calculate on a basis of a ratio of 6 to 1 for the cyt c reductase/nitrate reductase of purified normal enzyme. The demolybdoenzyme is incubated for 30 s at 31 degrees C with molybdate and reduced glutathione (GSH) at pH 4.8, and the pH is then raised to 7, and the incubation continued for 20 min. At the acid pH, there must be a partial denaturation or unfolding which permits Mo insertion, with a refolding to active enzyme at the higher pH. The GSH is not essential for activation, but in its absence the yield of active enzyme was about 50% lower. Experiments with labeled GSH showed that no GSH was incorporated into the protein during the activation procedure. Although the enzyme activity measurements suggested that only 30% of the enzyme was activated, measurements with 99Mo showed that there was one Mo incorporated per subunit weight of 90,000. The Km for nitrate of the activated nitrate reductase was identical with the Km for nitrate of the normal enzyme. On gradient centrifugation, activated nitrate reductase, cyt c reductase, and normal nitrate reductase all behaved identically.