Pulmonary injuries and cytokine levels after the intraperitoneal administration of pancreatic homogenates in rats.

INTRODUCTION: Our objective was to investigate the effects of the administration of pancreatic homogenates, with or without enzymatic activation, to healthy animals regarding cytokine serum levels and the development of pulmonary distress. MATERIAL AND METHODS: 106 male Wistar rats, divided into three groups, were studied: group A, intraperitoneal administration of homogenates activated with enterokinase; group B, homogenates without enterokinase; and group C, control group with administration of physiological saline solution. Each group was divided into 4 subgroups according to the time of sacrifice: 0, 2, 6 and 24 hours. We studied the pulmonary and pancreatic histology, serum parameters of renal and hepatic function, and serum levels of IL-1beta, IL-6 and TNFalpha. RESULTS: There was no mortality in any group. Pancreatic disorders in A and B groups were noted at 24 hours. These two groups had statistically significant higher transaminase serum levels than those of the control group, as well as statistically significant higher creatinine levels in group A. IL-1beta showed a statistically significant higher level at 6 h in both groups, A and B, but was higher in group A, which also exhibited significant pulmonary histologic damage with respect to controls at 6 h. CONCLUSIONS: The higher IL-1beta level in group A may result from production by peritoneal macrophages under the influence of homogenate enzymatic activation. This may be the reason for lung damage.     

Impaired activity of natural killer cells in patients with acute brucellosis.

Researchers have claimed that natural killer (NK) cells are involved in the mechanisms of defense of the host against infections. We have investigated the activity of NK cells in peripheral blood mononuclear cells (PBMNC) from 12 patients for whom acute brucellar infection has been diagnosed and from 14 healthy controls. The sera of eight of the patients were also analyzed 3 months after initiation of a 45-day course of antibiotic treatment, at which time they had no evidence of relapse. PBMNC from patients with acute brucellar infection showed a significantly depressed NK cell activity (P < .01) when compared with those from healthy controls; this depressed activity was not related to a deficient number of NK cells since the numbers of CD56+ and CD16+ cells present in PBMNC were similar in patients and controls. Incubation of PBMNC from patients with acute brucellar infection with recombinant interleukin-2, but not with interferon-gamma, can correct this impaired cytotoxic activity. In treated patients, there was a significant enhancement (P < .05) and normalization of the previously defective NK cell activity. It is concluded that acute brucellar infection is associated with a deficient cytotoxic activity of NK cells that can be overcome by in vitro incubation with interleukin-2 and that reverts to normal after antibiotic treatment.     

Carbon dioxide laser and bonding materials reduce enamel demineralization around orthodontic brackets

Altering the structure of the enamel surface around the orthodontic bracket by reducing its content of carbonate and phosphate resulting from application of CO₂ laser may represent a more effective strategy in preventing caries in this region. This study aimed at determining whether irradiation with a CO₂ laser combined with fluoride-releasing bonding material could reduce enamel demineralization around orthodontic brackets subjected to cariogenic challenge. Ninety bovine enamel slabs were divided into five groups (n?=?18): non-inoculated brain–heart infusion broth group, non-fluoride-releasing composite resin (NFRCR—control group), resin-modified glass ionomer cement (RMGIC), CO₂ laser + Transbond (L+NFRCR) and CO₂ laser + Fuji (L+RMGIC). Slabs were submitted to a 5-day microbiological caries model. The Streptococcus mutans biofilm formed on the slabs was biochemically and microbiologically analysed, and the enamel Knoop hardness number (KHN) around the brackets was determined. The data were analysed by ANOVA and Tukey tests (α?=?0.05). Biochemical and microbiological analyses of the biofilm revealed no statistically significant differences among the groups. Lased groups presented the highest KHN means, which statistically differed from NFRCR; however, no difference was found between these lased groups. RMGIC did not differ from NFRCR which presented the lowest KHN mean. The CO₂ laser (λ?=?10.6 μm; 10.0 J/cm² per pulse) use with or without F-bonding materials was effective in inhibiting demineralization around orthodontic brackets. However, no additional effect was found when the enamel was treated with the combination of CO₂ laser and an F-releasing material.