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Background: Recently, it has been found that nitrogen (N) deposition strongly affects the coverage of biocrusts. However, we know little about the response of exopolysaccharides (EPSs), the key cementing material in the formation and stability of biocrusts, to N deposition. Method: Three N-sources including nitrate, ammonia and urea were added to biocrusts at three rates (2 mg/g, 4 mg/g, 8 mg/g) to evaluate the effect of N additions on the growth of biocrusts and the abundance of EPS. Results: Our results showed 2 mg/g of nitrate–N had no obvious effect on the cyanobacterial biomass, while 4 and 8 mg/g of nitrate–N inhibited the growth of Microcoleus vaginatus, the dominant cyanobacterium in biocrusts, but promoted other cyanobacteria growth. Ammonia-N and urea-N strongly decreased the cyanobacterial biomass, indicated by chlorophyll-a and 16 s rRNA gene copy-numbers. On the whole, N additions had a positive impact on the α-biodiversity of biocrusts. However, Ammonia-N and urea-N shifted the bacterial communities from more Cyanobacteria to more Proteobacteria and Actinobacteria. Notably, lesser-N (2 mg/g) promoted the excretion of EPSs, while greater-N (8 mg/g) had the opposite effect, and the total proportion of rhamnose and fucose in EPSs decreased in all treatment groups. Conclusion: N additions (except 2 mg/g of nitrate–N) reduced cyanobacterial biomass and affected the bacterial communities in biocrusts, which would obstruct the development and succession of biocrusts. Meanwhile, the simultaneous reductions of the EPSs contents and proportion of rhamnose and fucose in EPSs may further reduce stability and persistence of cyanobacterial biocrusts, after N additions. [ABSTRACT FROM AUTHOR]

The aim of the study was to describe the oral health and orofacial function of Mexican patients with rheumatoid arthritis (RA) and their association with clinical and radiological aspects of the disease. Patients with RA received a complete odontological exam, which also included a clinical and radiographic assessment of the temporomandibular joint (TMJ). The rheumatologic assessment included detailed profiling of the disease and serological and radiographic parameters. The study included 62 RA patients; the median (min–max) age was 51 (18–72) years old and 8.5 (1–39) years of disease duration. The 63.6% of the patients had DAS28 ≥ 3.2, and a median (min–max) of Sharp/van der Heijde score (SvdHS) of 41 (0–214). 98.3% of the patients presented caries, which were severe in 53.3% of the cases. The 73.8% of the patients were missing teeth due to caries, with a median (min–max) of 4 (0–32) teeth missing per patient. Oral hygiene was classified as bad in 49.1% of patients and only 15.3% of them had a healthy periodontium. The TMJ function was abnormal in 98.4% of the patients and 62.9% of them presented moderate or severe TMJ disorder (TMD). The radiographic damage of the TMJ correlated positively with the SvdHS. No correlations were found between disease activity or structural progression and orofacial variables, including periodontitis. There are severe oral and orofacial health problems in RA patients despite having medical attention for their disease. Multidisciplinary management remains an area of opportunity for both the medical specialists and the health system in our country. [ABSTRACT FROM AUTHOR]

Background In the case of psoriatic patients, only a limited number of studies have related serum biological therapies and antidrug antibodies levels to clinical response. With respect to etanercept, the available evidence has not shown any relationship yet. Objective The aim of this study was to determine if there is any correlation among etanercept serum levels, the presence of anti-etanercept antibodies and clinical response to this treatment in psoriatic patients. Setting A 1500-bed hospital (A Coruña University Hospital Complex). Method A retrospective observational study in psoriatic patients treated with etanercept (50 mg once weekly) was carried out. Psoriasis Area and Severity Index scale and adverse reactions were recorded at the time of the extraction sample. The pharmacokinetic monitoring was evaluated at the previous time points by extracting peripheral blood samples before the dose administration. Etanercept and anti-etanercept antibodies concentrations were quantified by two sandwich-type ELISA immunoassays. The patients were classified into three groups (good, partial and nonresponders) in accordance with the treatment efficacy at the blood assessment moments. The Kruskall-Wallis test and Spearman correlation assay were used to assess the efficacy and incidence of adverse effects according to the etanercept concentration and anti-etanercept antibodies, considering p values of <0.05 as statistically significant. This statistical analysis was conducted using SPSS software (version19.0). Main outcome measures Etanercept and anti-etanercept antibodies trough serum levels and clinical response. Results 38 patients were included. 26 patients (68.4 %) were good, 5 (13.2 %) were partial and 7 (18.4 %) were non-responders. There was no significant difference with respect to etanercept levels: 2.7 μg/mL (range 0.7-5.6) versus 2.2 μg/mL (range 1.0-3.5) versus 1.73 μg/mL (range 0.1-2.3), respectively (p = 0.085). Nevertheless, a positive correlation between percentage decrease in the Psoriasis Area and Severity Index scale value with respect to the baseline value and etanercept concentration was found (p = 0.011). No anti-etanercept antibodies were detected; nor was there a significant difference in the incidence of adverse effects (p = 0.8523). Conclusions Our results showed a positive correlated between etanercept concentration and the percentage decrease in the Psoriasis Area and Severity Index scale value. The incidence of anti-etanercept antibodies in psoriatic patients was low. [ABSTRACT FROM AUTHOR]

An introduction to the November 2008 issue of "International Review of Education," is presented.