Comparison of Shigella GMMA and glycoconjugate four-component formulations in animals

Shigellosis is leading bacterial cause of diarrhea with high prevalence in children younger than 5 years in low- and middle-income countries, and increasing number of reports of Shigella cases associated to anti-microbial resistance. No vaccines against Shigella are still licensed, but different candidates based on the O-antigen portion of lipopolysaccharides are in clinic. Generalized Modules for Membrane Antigens (GMMA) have been proposed as an alternative delivery system for the O-antigen, and a 4-component vaccine candidate (altSonflex1-2-3), containing GMMA from S. sonnei and S. flexneri 1b, 2a and 3a is being tested in a phase 1/2 clinical trial, with the aim to elicit broad protection against the most prevalent Shigella serotypes. Here, the 4-component GMMA vaccine candidate has been compared to a more traditional glycoconjugate formulation for the ability to induce functional antibodies in mice and rabbits. In mice, in the absence of Alhydrogel, GMMA induce higher IgG antibodies than glycoconjugates and stronger bactericidal titers against all Shigella serotypes. In the presence of Alhydrogel, GMMA induce O-antigen specific IgG levels similar to traditional glycoconjugates, but with a broader range of IgG subclasses, resulting in stronger bactericidal activity. In rabbits, GMMA elicit higher functional antibodies than glycoconjugates against S. sonnei, and similar responses to S. flexneri 1b, 2a and 3a, independently from the presence of Alhydrogel. Different O-antigen based vaccines against Shigella are now in clinical stage and it will be of particular interest to understand how the preclinical findings in the different animal models translate in humans

Assessment of Apolipoprotein(a) Isoform Size Using Phenotypic and Genotypic Methods

Apolipoprotein(a) (apo(a)) is the protein component that defines lipoprotein(a) (Lp(a)) particles and is encoded by the LPA gene. The apo(a) is extremely heterogeneous in size due to the copy number variations in the kringle-IV type 2 (KIV2) domains. In this review, we aim to discuss the role of genetics in establishing Lp(a) as a risk factor for coronary heart disease (CHD) by examining a series of molecular biology techniques aimed at identifying the best strategy for a possible application in clinical research and practice, according to the current gold standard

Purine Metabolism Dysfunctions: Experimental Methods of Detection and Diagnostic Potential

Purines, such as adenine and guanine, perform several important functions in the cell. They are found in nucleic acids; are structural components of some coenzymes, including NADH and coenzyme A; and have a crucial role in the modulation of energy metabolism and signal transduction. Moreover, purines have been shown to play an important role in the physiology of platelets, muscles, and neurotransmission. All cells require a balanced number of purines for growth, proliferation, and survival. Under physiological conditions, enzymes involved in purines metabolism maintain a balanced ratio between their synthesis and degradation in the cell. In humans, the final product of purine catabolism is uric acid, while most other mammals possess the enzyme uricase that converts uric acid to allantoin, which can be easily eliminated with urine. During the last decades, hyperuricemia has been associated with a number of human extra-articular diseases (in particular, the cardiovascular ones) and their clinical severity. In this review, we go through the methods of investigation of purine metabolism dysfunctions, looking at the functionality of xanthine oxidoreductase and the formation of catabolites in urine and saliva. Finally, we discuss how these molecules can be used as markers of oxidative stress

Serum SCCA-IgM as a predictor of hepatocellular carcinoma in patients with liver cirrhosis

Aberrant Squamous Cell Carcinoma Antigen (SCCA) expression is an early hepatocarcinogenetic event and circulating SCCA-IgM complexes are elevated in most HCC patients. We evaluated whether serum SCCA-IgM levels can identify HCV +ve cirrhotic patients at low HCC risk. In this retrospective study we enrolled 29 cirrhotic patients in whom serum SCCA-IgM was measured 8 - 69 months (median 31) before HCC diagnosis, and 28 cirrhotic patients who remained HCC- free, with SCCA-IgM measured 15 - 68 months (median 48) before the study end. The best discriminating value of SCCA-IgM was calculated and tested in predicting HCC diagnosis within 12, 24 and 36 months. Sensitivity analysis, considering different HCC incidence, was conducted to identify the patient subgroup with an annual cancer risk below the threshold of a cost-effective semiannual surveillance with ultrasound. Cumulative HCC incidence at 12, 24 and 36 months was 7.0%, 15.7% and 26.3%, respectively. SCCA-IgM levels were higher in HCC than in cirrhotic patients [median: 381 (95% C.I.: 50 - 5289) vs. 100 (70 - 493) AU/mL, P = 0.005]. The SCCA-IgM value 64 200 AU/mL accurately identified patients at low risk of HCC development in the subsequent year (sensitivity 75%, specificity 62%, positive predictive value 13% and negative predictive value 97%). Considering an annual HCC incidence 64 3%, patients with SCCA-IgM 64 200 AU/mL (60% of the whole patients) had an HCC risk below the accepted threshold of a cost-effective surveillance (1.5%). In conclusion, provided that our provocative results are confirmed in larger studies, SCCA-IgM serum measurement could permit implementation of a two step (with different costs) surveillance: an initial serological surveillance, based on the annual monitoring of this biomarker, and the conventional surveillance by semiannual US when SCCA-IgM becomes >200 AU/mL. This could improve the cost/effectiveness of surveillance of HCV infected patients at risk of HC