Guided bone regeneration produced by new mineralized and reticulated collagen membranes in critical-sized rat calvarial defects.

The aim of this study was to evaluate the bone regenerative effect of glutaraldehyde (GA) cross-linking on mineralized polyanionic collagen membranes in critical-sized defects on rat calvarias. Bone calvarial defects were induced in Wistar rats, which were then divided into five groups: a sham group; a control group, which received a commercial membrane; and GA, 25GA, and 75GA groups, which received one of three different polyanionic collagen membranes mineralized by 0, 25, or 75 hydroxyapatite cycles and then cross-linked by GA. Bone formation was evaluated based on digital radiography and computerized tomography. Histological analyses were performed 4 and 12 weeks after the surgical procedure to observe bone formation, membrane resorption, and fibrous tissue surrounding the membranes. Measurement of myeloperoxidase activity, tumor necrosis factor alpha, and interleukin 1beta production was performed 24 h after surgery. The percentage of new bone formation in the GA, 25GA, and 75GA groups was higher compared with the control and sham groups. In the GA and 25 GA groups, the membranes were still in place and were contained in a thick fibrous capsule after 12 weeks. No significant difference was found among the groups regarding myeloperoxidase activity and interleukin 1beta levels, although the GA, 25GA, and 75GA groups presented decreased levels of tumor necrosis factor alpha compared with the control group. These new GA cross-linked membranes accelerated bone healing of the calvarium defects and did not induce inflammation. In addition, unlike the control membrane, the experimental membranes were not absorbed during the analyzed period, so they may offer advantages in large bone defects where prolonged membrane barrier functions are desirable.

Factors associated with thrombocytopenia in severe leptospirosis (Weil's disease).

OBJECTIVE: This study was conducted to investigate factors associated with thrombocytopenia in a large cohort of patients with leptospirosis in an endemic area. METHODS: This retrospective study included 374 consecutive patients with leptospirosis who were admitted to tertiary hospitals in Fortaleza, Brazil. All patients had a diagnosis of severe leptospirosis (Weil's disease). Acute kidney injury was defined according to the RIFLE criteria. Thrombocytopenia was defined as a platelet count <100,000/mm3. RESULTS: A total of 374 patients were included, with a mean age of 36.1 ± 15.5 years, and 83.4% were male. Thrombocytopenia was present at the time of hospital admission in 200 cases (53.5%), and it developed during the hospital stay in 150 cases (40.3%). The patients with thrombocytopenia had higher frequencies of dehydration (53% vs. 35.3%, p=0.001), epistaxis (5.7% vs. 0.8%, p=0.033), hematemesis (13% vs. 4.6%, p=0.006), myalgia (91.5% vs. 84.5%, p=0.038), hematuria (54.8% vs. 37.6%, p=0.011), metabolic acidosis (18% vs. 9.2%, p=0.016) and hypoalbuminemia (17.8% vs. 7.5%, p=0.005). The independent risk factors associated with thrombocytopenia during the hospital stay were lengthy disease (OR: 1.2, p=0.001) and acute kidney injury (OR: 6.6, p=0.004). Mortality was not associated with thrombocytopenia at admission (12.5% vs. 12.6%, p=1.000) or during the hospital stay (12.6% vs. 11.3%, p=0.748). CONCLUSIONS: Thrombocytopenia is a frequent complication in leptospirosis, and this condition was present in more than half of patients at the time of hospital admission. Lengthy disease and acute kidney injury are risk factors for thrombocytopenia. There was no significant association between thrombocytopenia and mortality.

Factors associated with thrombocytopenia in severe leptospirosis (Weil's disease)

OBJECTIVE: This study was conducted to investigate factors associated with thrombocytopenia in a large cohort of patients with leptospirosis in an endemic area. METHODS: This retrospective study included 374 consecutive patients with leptospirosis who were admitted to tertiary hospitals in Fortaleza, Brazil. All patients had a diagnosis of severe leptospirosis (Weil's disease). Acute kidney injury was defined according to the RIFLE criteria. Thrombocytopenia was defined as a platelet count <100,000/mm3. RESULTS: A total of 374 patients were included, with a mean age of 36.1±15.5 years, and 83.4% were male. Thrombocytopenia was present at the time of hospital admission in 200 cases (53.5%), and it developed during the hospital stay in 150 cases (40.3%). The patients with thrombocytopenia had higher frequencies of dehydration (53% vs. 35.3%, p = 0.001), epistaxis (5.7% vs. 0.8%, p = 0.033), hematemesis (13% vs. 4.6%, p = 0.006), myalgia (91.5% vs. 84.5%, p = 0.038), hematuria (54.8% vs. 37.6%, p = 0.011), metabolic acidosis (18% vs. 9.2%, p = 0.016) and hypoalbuminemia (17.8% vs. 7.5%, p = 0.005). The independent risk factors associated with thrombocytopenia during the hospital stay were lengthy disease (OR: 1.2, p = 0.001) and acute kidney injury (OR: 6.6, p = 0.004). Mortality was not associated with thrombocytopenia at admission (12.5% vs. 12.6%, p = 1.000) or during the hospital stay (12.6% vs. 11.3%, p = 0.748). CONCLUSIONS: Thrombocytopenia is a frequent complication in leptospirosis, and this condition was present in more than half of patients at the time of hospital admission. Lengthy disease and acute kidney injury are risk factors for thrombocytopenia. There was no significant association between thrombocytopenia and mortality. .