The importance of a two-step impression procedure for complete denture fabrication: a systematic review of the literature.

The literature has questioned the real need for some clinical and laboratory procedures considered essential for achieving better results for complete denture fabrication. The aim of this study was to review the current literature concerning the relevance of a two-step impression procedure to achieve better clinical results in fabricating conventional complete dentures. Through an electronic search strategy of the PubMed/MEDLINE database, randomised controlled clinical trials which compared complete denture fabrication in adults in which one or two steps of impressions occurred were identified. The selections were made by three independent reviewers. Among the 540 titles initially identified, four studies (seven published papers) reporting on 257 patients evaluating aspects such as oral health-related quality of life, patient satisfaction with dentures in use, masticatory performance and chewing ability, denture quality, direct and indirect costs were considered eligible. The quality of included studies was assessed according to the Cochrane guidelines. The clinical studies considered for this review suggest that a two-step impression procedure may not be mandatory for the success of conventional complete denture fabrication regarding a variety of clinical aspects of denture quality and patients' perceptions of the treatment.

Splenic autotransplantation reverses interferon-gamma and nitric oxide production and resistance to Listeria monocytogenes in splenectomized mice.

Splenectomized mice control Listeria monocytogenes infection better than non-splenectomized mice. Here, BALB/c mice subjected to splenectomy and autogenous grafting of spleen were evaluated after 3 and 7 days of intravenous L. monocytogenes infection. The group of splenectomized animals (SP) presented a lower number of bacteria in the liver in comparison with both the sham-operated control group (CT) and the group that received splenic autotransplantation (AT) in the retroperitoneal site. The AT group presented bacterial counts in the liver similar to the CT group. SP animals showed larger production of interferon-gamma (IFN-γ) and nitric oxide (NO) in the liver in comparison with CT and AT, this being associated with greater accumulation of mononuclear cells. IFN-γ production by spleen cells after stimulation with heat-killed Listeria was similar between the AT and CT groups, suggesting that the implanted fragments behaved like the original organ. The autogenous grafting of spleen fragments reverses the resistance to L. monocytogenes infection found in splenectomized mice, associated with a reduced IFN-γ and NO production in the liver. The present study shows that splenic autotransplantation restores the function of the spleen in splenectomized mice, even though in this case it does favor the susceptibility to L. monocytogenes infection.

Increased susceptibility to Strongyloides venezuelensis in mice due to Mycobacterium bovis co-infection which modulates production of Th2 cytokines.

An estimated quarter of the world's population possesses an infection caused by gastrointestinal nematodes, which induce a Th2 type immune response. Concomitant infection of nematodes with Mycobacterium tuberculosis, which induces a predominantly Th1 type response, is very frequent in tropical and subtropical regions. This study examined immune responses of BALB/c mice infected with Strongyloides venezuelensis and then co-infected with Mycobacterium bovis. The number of worms in the intestine, eggs in feces, cytokine production in lungs and intestine and the expression of CD80, CD86, CTLA-4 and CD28 cell markers on pulmonary cells were analysed. Our results indicate that co-infected mice had an increased parasite burden, which correlates with elevated IFN-gamma and IL-10 cytokine production and decreased IL-4 and IL-13. Moreover, decreased expression of CD80 and increased expression of CTLA-4 were observed in co-infected mice. Our data point out that susceptibility to Strongyloides venezuelensis infection is increased by Mycobacterium bovis co-infection, resulting in higher parasite survival.

Staphylococcus aureus infection after splenectomy and splenic autotransplantation in BALB/c mice.

Splenectomy results in an increased risk of sepsis. The autogenous transplant of the spleen is an option for preserving splenic functions after total splenectomy. In this study, the capacity of animals undergoing autogenous spleen transplantation to respond to Staphylococcus aureus infection was investigated. BALB/c mice were divided into three groups: splenectomy followed by autotransplantation in the retroperitonium (AT), splenectomized only (SP) and operated non-splenectomized sham control (CT). Thirty days after surgery the mice were infected intravenously with S. aureus. Splenectomized mice had a higher number of colony-forming units (CFU) of S. aureus in liver and lungs in comparison with either AT or with CT mice (P < 0.05). Higher CFU numbers in lung of SP mice correlated with elevated production of interleukin-10 associated with a lower production of interferon-gamma and tumour necrosis factor-alpha. However, systemically, the level of tumour necrosis factor-alpha was higher in the SP group than in CT or AT. Lower titres of specific anti-S. aureus immunoglobulin (Ig)M and IgG1 were observed 6 days after infection in SP mice in comparison either with the AT or CT groups. Thus, splenectomy is detrimental to the immune response of BALB/c mice against infection by S. aureus which can be re-established by autogenous implantation of the spleen.

Serum levels of nitric oxide and cytokines in smokers at the beginning and after 4months of treatment for smoking cessation.

INTRODUCTION: Nitric oxide (NO) modulates inflammatory reactions, having beneficial or toxic effects depending on the concentration. Its elevation can cause proinflammatory effects amplifying the inflammatory process with the participation of cytokines. Smoking has a negative impact on health and is considered one of the risk factors that influence disease development facilitating inflammatory processes. AIM: To compare the serum concentration of NO and cytokines in smokers at baseline and after 4months of abstinence treatment. METHODS: Blood samples which were collected to obtain the serum, at baseline and after 4months, were stored at -80°C until analysis. NO was measured by the total dose of nitrite determined by the Greiss method. CBA was the used technique to determine the concentration of cytokines in supernatants serum. The initial and final results of NO, TNF-α, IL-1, IL-6, IL-8, IL-10 and IL-12 that remained after 4months treatment were compared. Wilcoxon test was used to compare the data and Spearman test for correlations between NO and other variables. A significance level of p<0.05 was adopted. RESULTS: The analysis of NO observed a significant reduction (p=0.001) of the initial median value of 18.80 (3.55-80.01) µmol/L to 8.10 (2.85-14.97) µmol/L after 4months of treatment. There were no significant differences in cytokines from baseline to the end of treatment. CONCLUSION: The results may not mean harm to the body, but an adaptive process, decreasing the metabolism of abstinents due to the reduction of the use of nicotine.

Splenic autotransplantation restores IL-17 production and antibody response to Streptococcus pneumoniae in splenectomized mice.

The high incidence of overwhelming postsplenectomy infection caused by Streptococcus pneumoniae can be reduced by splenic autotransplantation. In this study the effect of splenectomy and splenic autotransplantation on the immune response to S. pneumoniae infection was investigated. Balb/c mice were divided into three groups: splenectomized (SP), splenectomized and autotransplanted (AT), and sham operated control (CT). Five days post-infection the serum antibody levels were measured and the number of S. pneumoniae CFU, neutrophil accumulation and IL-17 production in the liver and lungs were investigated. SP mice showed greater number of bacteria in both organs and lower serum levels of S. pneumoniae-specific IgM, IgG1 and IgG2a antibodies. IL-17 production and neutrophil recruitment to the liver and lungs were lower in SP mice, in comparison with both the CT and the AT groups. Levels of S. pneumoniae-specific IgM, CFU counts, neutrophil accumulation and IL-17 production did not differ significantly between the CT and AT groups. These results suggest that splenic autotransplantation restores the capacity of splenectomized mice to fight S. pneumoniae infection.