Role of neuronal and inducible nitric oxide synthases in the guinea pig ileum myenteric plexus during in vitro ischemia and reperfusion

Background Intestinal ischemia and reperfusion (I/R) injury leads to abnormalities in motility, namely delay of transit, caused by damage to myenteric neurons. Alterations of the nitrergic transmission may occur in these conditions. This study investigated whether an in vitro I/R injury may affect nitric oxide (NO) production from the myenteric plexus of the guinea pig ileum and which NO synthase (NOS) isoform is involved. Methods The distribution of the neuronal (n) and inducible (i) NOS was determined by immunohistochemistry during 60 min of glucose/oxygen deprivation (in vitro ischemia) followed by 60 min of reperfusion. The protein and mRNA levels of nNOS and iNOS were investigated by Westernimmunoblotting and real time RT-PCR, respectively. NO levels were quantified as nitrite/nitrate. Key Results After in vitro I/R the proportion of nNOSexpressing neurons and protein levels remained unchanged. nNOS mRNA levels increased 60 min after inducing ischemia and in the following 5 min of reperfusion. iNOS-immunoreactive neurons, protein and mRNA levels were up-regulated during the whole I/R period. A significant increase of nitrite/nitrate levels was observed in the first 5 min after inducing I/R and was significantly reduced by Nx-propyl-L-arginine and 1400 W, selective inhibitors of nNOS and iNOS, respectively. Conclusions & Inferences Our data demonstrate that both iNOS and nNOS represent sources for NO overproduction in ileal myenteric plexus during I/R, although iNOS undergoes more consistent changes suggesting a more relevant role for this isoform in the alterations occurring in myenteric neurons following I/R

GMMA as an alternative carrier for a glycoconjugate vaccine against Group A streptococcus

Group A Streptococcus (GAS) causes about 500,000 annual deaths globally, and no vaccines are currently available. The Group A Carbohydrate (GAC), conserved across all GAS serotypes, conjugated to an appropriate carrier protein, represents a promising vaccine candidate. Here, we explored the possibility to use Generalized Modules for Membrane Antigens (GMMA) as an alternative carrier system for GAC, exploiting their intrinsic adjuvant properties. Immunogenicity of GAC-GMMA conjugate was evaluated in different animal species in comparison to GAC-CRM197; and the two conjugates were also compared from a techno-economic point of view. GMMA proved to be a good alternative carrier for GAC, resulting in a higher immune response compared to CRM197 in different mice strains, as verified by ELISA and FACS analyses. Differently from CRM197, GMMA induced significant levels of anti-GAC IgG titers in mice also in the absence of Alhydrogel. In rabbits, a difference in the immune response could not be appreciated; however, antibodies from GAC-GMMA-immunized animals showed higher affinity toward purified GAC antigen compared to those elicited by GAC-CRM197. In addition, the GAC-GMMA production process proved to be more cost-effective, making this conjugate particularly attractive for low- and middle-income countries, where this pathogen has a huge burden

Implantation of fiducial markers in the liver for stereotactic body radiation therapy: Feasibility and results

International audiencePurposeRobotic stereotactic body radiation therapy (SBRT) for the treatment of hepatocellular carcinoma requires the perilesional implant of gold fiducial markers for detection by scopy. The purpose of this study is to determine whether the implant of gold fiducial markers is still possible and, if so, with which imaging technique and with what results.Materials and methodsThis is a prospective study based on the implant of fiducial markers in the liver in our department for a treatment by SBRT for a hepatocellular carcinoma in 38 patients (49 lesions to treat) over a period of one year. As the first choice, it consisted of sonographic guidance and, if not possible, CT-scan guidance was used.ResultsThe mean number of fiducial markers implanted per procedure was 2.68(± 0.61) with almost exclusive sonographic guidance (36 out of 38 patients or 95% of the patients). The mean distance between the markers and the lesion was 32 mm (± 11 mm) and that between the markers was 17 mm (± 7 mm).ConclusionSBRT is being evaluated for the treatment of liver lesions. The radiologist has an important role to play since the implant of fiducial markers in the liver is indispensable. It is almost always possible with sonographic guidance, including for lesions not accessible to microbiopsies, a treatment by radiofrequency or for lesions poorly individualisable by sonography or CT-scan