Immunogenicity and protective efficacy of yeast extracts containing rotavirus-like particles: A potential veterinary vaccine

Rotavirus is the most common cause of severe diarrhea in many animal species of economic interest. A simple, safe and cost-effective vaccine is required for the control and prevention of rotavirus in animals. In this study, we evaluated the use of Saccharomyces cerevisiae extracts containing rotavirus-like particles (RLP) as a vaccine candidate in an adult mice model. Two doses of 1 mg of yeast extract containing rotavirus proteins (between 0.3 and 3 μg) resulted in an immunological response capable of reducing the replication of rotavirus after infection. Viral shedding in all mice groups diminished in comparison with the control group when challenged with 100 50% diarrhea doses (DD₅₀) of murine rotavirus strain EDIM. Interestingly, when immunizing intranasally protection against rotavirus infection was observed even when no increase in rotavirus-specific antibody titers was evident, suggesting that cellular responses were responsible of protection. Our results indicate that raw yeast extracts containing rotavirus proteins and RLP are a simple, cost-effective alternative for veterinary vaccines against rotavirus.     

Mutations in the helix αC of the catalytic domain from the EGFR affect its activity in cervical cancer cell lines

The EGFR is a protein that belongs to the ErbB family of tyrosine kinase receptors. The EGFR is often overexpressed in human carcinomas. Amplification of the EGFR gene and mutations in the EGFR tyrosine kinase domain occur in patients with cancer. In cervical cancer, the expression level of the EGFR protein appears to directly associate with human papillomavirus infection. Our previous research demonstrated that in the cervical cancer cell lines, CALO and INBL, the EGFR is non-phosphorylated. The aim of the current study was to analyze the catalytic activity of the isolated EGFR and the presence of mutations in the control region αC. Catalytic activity was assessed by a universal in vitro kinase assay using polyGluTyr as a substrate, and the proteins were visualized by western blotting. For mutation analysis, DNA from CALO and INBL cell lines was isolated, and PCR was used to amplify the exons corresponding to the helix αC in the EGFR. The PCR products were visualized by agarose gel electrophoresis. The bands were isolated using a Zymoclean Gel DNA Recovery kit and directly sequenced. The EGFR, which was isolated and analyzed using the in vitro kinase assay, had catalytic activity. The receptor contained some mutations in the helix αC of the catalytic domain in both cell lines. The observed changes in the amino acid sequence may induce a different spatial arrangement and, therefore, a different conformation, which may confer different activities to this receptor. Thus, it was concluded that non-phosphorylated EGFR has catalytic activity, and it bears some amino acid changes in the helix αC of the catalytic domain in the CALO and INBL cells. These results suggest that the EGFR may function as an activator of other ErbB family receptors in these cervical cancer cells.     

Synthesis of water-soluble ionic terpolymers by inverse microemulsion and solution polymerization methods

The synthesis of terpolymers can lead to very interesting combinations of monomers, which can affect the solubility of the polymer, its thermal stability or resistance in saline aqueous media. Free-radical inverse microemulsion and solution polymerization techniques were used to prepare water-soluble acrylamide-N-vinylpyrrolidone-(vinylbenzyl)trimethylammonium chloride terpolymers. The formulation of the polymerizable microemulsion was optimized by using the screening of surfactant percentage and HLB concept. The influence of synthesis temperature on the terpolymer composition and molecular weight was investigated. The reactions were carried out at 60, 70, and 75 °C for the microemulsion technique and at 40, 50, and 55 °C for the solution polymerization technique. The reaction products from both processes were water-soluble polymers, and the two techniques reached high conversions and molecular masses. Maximal molecular weights were displayed by terpolymers prepared by the solution method at 40 °C (959, 840 g mol⁻¹) and the inverse microemulsion method at 60 °C (795, 994 g mol⁻¹). According to NMR analysis, the highest amount of (vinylbenzyl) trimethylammonium chloride was incorporated into the terpolymer structure by the inverse microemulsion method. In contrast, the solution method yielded higher contents of acrylamide and N-vinylpyrrolidone. The viscosity properties of the terpolymers in aqueous solutions were directly correlated to their molecular weight and synthesis conditions.

Terpolymers based on acrylamide, N-vinylpyrrolidone and (vinylbenzyl)trimethylammonium chloride (VBTA) were synthesized using inverse microemulsion and solution methods. The microemulsion promoted the incorporation of VBTA in the terpolymer structure.     

Effect of dexamethasone on respiratory syncytial virus-induced lung inflammation in children: results of a randomized, placebo controlled clinical trial

Inflammatory mediators play a major role in the pathogenesis of respiratory syncytial virus (RSV) infection. The objective of this study was to evaluate the effect of i.v. dexamethasone on cytokine concentrations in tracheal aspirates (TA) of children with severe RSV disease and to correlate them with disease severity. Twenty-five cytokines were measured in TA obtained from children <2 yr old intubated for severe RSV disease, and enrolled in a double-blind study of i.v. dexamethasone (0.5 mg/kg; n = 22) vs. placebo (n = 19). Cytokine concentrations, measured at baseline and days 1 and 5 post-randomization using a multiplex assay, were compared within both treatment groups and correlated with: (i) tracheal white blood cell counts, (ii) tracheal RSV loads by culture and (iii) parameters of disease severity, including number of days of requirement for mechanical ventilation, intensive care unit (ICU), and hospitalization. At baseline interleukin (IL)-13 and IL-15 concentrations were significantly higher in the dexamethasone treatment group. On day 1 post-treatment, only MCP-1, eotaxin and IL-6 concentrations were significantly different but higher in the placebo group. On day 5: IL-13, IL-7, IL-8 and MIP-1α concentrations were higher in dexamethasone-treated patients. In both groups MIP-1β inversely correlated with the days of ventilator support; MIP-1α, MIP-1β and eotaxin inversely correlated with ICU days; and IL-6 inversely correlated with hospitalization regardless of the treatment assigned. Systemic administration of dexamethasone did not have a consistent effect on TA concentrations of pro-inflammatory cytokines. This may help explain, at least in part, the lack of clinical benefit of steroid treatment in children with severe RSV bronchiolitis.     

Laparoscopic management of symptomatic and large adrenal cysts

PURPOSE: We present the feasibility and results of the laparoscopic management of symptomatic and large adrenal cysts. MATERIALS AND METHODS: From June 1993 to April 2004 we performed 149 laparoscopic adrenalectomies. In this series 8 patients with symptomatic adrenal cysts or pseudocysts were treated laparoscopically. Surgical indications for laparoscopic management of adrenal cysts were abdominal pain in 5 cases and cyst size 5 cm or greater in 3. RESULTS: The incidence of adrenal cyst was 5.4% (8 of 149 cases). Six patients underwent laparoscopic adrenal cyst decortication and marsupialization, 1 underwent laparoscopic partial adrenalectomy and 1 underwent laparoscopic adrenalectomy. Mean operative time was 77.5 minutes. There were no intraoperative or postoperative complications. Mean hospital stay was 1.7 days. At a mean followup of 18.5 months all patients were asymptomatic and without radiographic evidence of cyst recurrence. CONCLUSIONS: Laparoscopic conservative management of adrenal cysts is safe and feasible. Laparoscopic decortication and marsupialization should be the preferred treatment option for symptomatic adrenal cysts. Laparoscopic partial adrenalectomy or a total adrenalectomy can be performed in cases of larger cysts which compromise most of the adrenal gland. To our knowledge, this represents the largest series of symptomatic adrenal cysts managed laparoscopically.     

Polychlorinated biphenyls: Photolysis of 3,4,3′,4′-tetrachlorobiphenyl and 4,4′-dichlorobiphenyl in solution

Summary The large difference in retention times for the photoproducts of 3,4,34-tetrachlorobiphenyl can be explained on the basis of their chlorine content and the effect of vicinal chlorosubstitution as observed by V. Zitko and coworkers (4).The absence of biphenyl among the photoproducts of 4,4-dichlorobiphenyl was not surprising since 4-chlorobiphenyl (max 203, 253) does not absorb at the wavelength of irradiation (>286), 4,4-dichlorobiphenyl exhibits only marginal absorption at this wavelength (max 201, 259, 286) this explains the low yield of 4-chlorobiphenyl obtained (appx. .1%). The greater reactivity at the meta position may be the result of bond weakening due to steric interactions with the chlorine atom at the para position. Rate studies may provide an answer to this problem.