[Development of animal experimental model for bacterial peritonitis]. / Desarrollo de modelo experimental animal de peritonitis bacteriana.

OBJECTIVE: The aim of the study was to develop a model of abdominal sepsis in the experimental animal. METHODS: Sprague-Dawley male rats of 5 weeks (N=39) were used. Initially, a pilot study (N = 9) was performed and distributed in 3 groups with 1cc inoculum of Escherichia coli ATCC 25922 intraperitoneally at concentrations of 10E8, 10E9 and 10E10 CFU. Subsequently, concentrations of 10E10 CFU are used in two groups of 3 rats with dilutions of 10 cc and 15 cc of distilled water respectively. Finally, a randomized trial of 24 rats was started in three treatment groups after intraperitoneal infection: Group I with physiological serum (N = 6), Group II with ceftriaxone (N = 9), Group III with ceftriaxone plus allicin (N = 9). Microbiological samples of blood and peritoneal fluid were made, as well as histopathological study of intraperitoneal organs (liver, diaphragm and peritoneum). RESULTS: Death of 100% of the rats infected with 10E10 E. coli UFC concentration with the dilution of 15 ml of distilled water and without antibiotic was oberved. The blood culture and peritoneal fluid culture was positive for the same strain in all of them. The formation of abscesses on the liver surface and polymorphonuclear infiltration in tissues were observed. CONCLUSIONS: The lethal dose of E. coli is 10E10 CFU diluted in 15 cc distilled water by intraperitoneal injection.

The role of polyhedral oligomeric silsesquioxane on the thermo-mechanical properties of polyoxymethylene copolymer based nanocomposites.

Hybrid nanocomposites formed with polyoxymethylene copolymer (POM) and different types of polyhedral oligomeric silsesquioxane (POSS) nanoparticles have been investigated. Four types of POSS have been studied in contents of 2.5% and 5% wt. The POSS were incorporated by direct melt-mixing. Traditionally copolymerization has been the preferred approach used to form polymer-POSS nanocomposites because the possibility of immiscibility with the polymer matrix is reduced. However, melt-blended POSS nanoparticles can also improve the thermo-mechanical properties of some polymers. Different morphologies were obtained depending on the type of POSS used. GI-POSS and O-POSS exhibit sub-micron or micron-sized inclusions which size increased with increasing percentages of POSS added. On the other hand, both G-POSS and T-POSS appeared to be uniformly dispersed in the POM matrix probably at a molecular level. This is a clear indication of miscibility between these systems and also that POSS solubility in POM is higher than 5 wt%. G-POSS improved the thermal stability of the systems. However, the melting temperature and the modulus of elasticity were found to slightly decrease. On the other hand, the O-POSS produced the opposite effect in the matrix. Finally T-POSS filled systems do not yield important variations in regard to polymethylene oxide properties although interaction between T-POSS and the matrix was detected.

Human infection with Hymenolepis diminuta: case report from Spain.

We report a case of Hymenolepis diminuta infection in a human. The patient was a 5-year-old girl referred to us through the onset of a cyanotic attack. Treatment with a single dose (10 mg/kg of body weight) of praziquantel was ineffective, but the parasite was eradicated after three treatment cycles with the same drug at dosages of 25 mg/kg/day for 5 days.