Levels of soluble ICAM-1 in premature and full-term neonates with infection

BACKGROUND: Infection in the neonatal period is an extremely serious condition and diagnosis is difficult. C-reactive protein (CRP) is widely used as a marker of infection; however, its usefulness is limited in the early phase. The role of soluble intracellular adhesion molecule-1 (sICAM-1), an adhesion molecule, has been examined in recent studies as an early marker of neonatal infection with controversial results. AIM: Assessment of sICAM-1 concentrations and correlation with CRP, which is the currently used marker of infection, in order to use sICAM as an early diagnostic tool in neonates suspected for infection METHODS: Blood samples and blood cultures were obtained from two groups of pre-term and full-term neonates with clinical suspicion of infection prior to the initiation of antibiotics. The sICAM-1 and CRP values were compared with the corresponding noninfected ones (n = 10 each). RESULTS: The sICAM-1 levels were found increased in the group of both premature and term neonates with infection compared with the corresponding healthy ones (P < 0.0001). Prematurity combined with infection resulted in excessive increase of the levels of sICAM-1 in comparison with full-term infected newborns (p < 0.001). CRP values were normal in all samples except one in both full-term and premature infected neonates on day 1 of clinically suspected infection. Serial detection of CRP values on days 2 and 4 of infection revealed a pattern according to which CRP values in premature neonates continued rising, while in the group of full terms these values, after rising on the second day, lowered on day 4. CONCLUSIONS: Increased sICAM-1 levels can be detected early in both full-term and premature neonates with sepsis while CRP levels are within normal range at the same time. Assessment of sICAM-1 concentrations may be used as a diagnostic tool in neonates suspected for infection, resulting in earlier initiation of antibiotic therapy and therefore improving their outcome.     

Molecular phylogeographic analyses of the loach Oxynoemacheilus bureschi reveal post‐glacial range extensions across the Balkans

Rivers on the Balkan Peninsula can be separated into ichthyofaunistic areas with different endemic fish species. The Vardar River contains a particularly large number of endemics, indicating its complete and long‐term isolation from neighbouring river systems. One of the few species shared with other rivers is the loach species Oxynoemacheilus bureschi. In this study, the genetic analyses of 175 individuals of O. bureschi from 17 sites, covering the entire distribution of the species, including the Rivers Vardar (= Axios), Struma (= Strymon), Mesta (= Nestos) and Danube, were performed using one mitochondrial and one nuclear marker. Genetic differentiation among populations was in general low. Shared haplotypes were common and occurred even between distant localities and different river systems. This points to a high degree of gene flow among populations and rejects the hypothesis that the population in the Vardar River represents a relict from an early colonization of the Balkan Peninsula. In contrast, the results suggest that populations in the Vardar River, as well as those in the Danube River, are of recent origin, and a human‐mediated introduction cannot be excluded. On the other hand, the populations in the Aggitis River, a left tributary of the lower Struma River, were clearly separated from the rest of the species and represent a long‐term isolated lineage. Demographic analyses suggest a recent population expansion for O. bureschi, in which the population in the Aggitis River was not involved.     

Dual oxidase-2 has an intrinsic Ca2+-dependent H2O2-generating activity

Duox2 (and probably Duox1) is a glycoflavoprotein involved in thyroid hormone biosynthesis, as the thyroid H2O2 generator functionally associated with Tpo (thyroperoxidase). So far, because of the impairment of maturation and of the targeting process, transfecting DUOX into nonthyroid cell lines has not led to the expression of a functional H2O2-generating system at the plasma membrane. For the first time, we investigated the H2O2-generating activity in the particulate fractions from DUOX2- and DUOX1-transfected HEK293 and Chinese hamster ovary cells. The particulate fractions of these cells stably or transiently transfected with human or porcine DUOX cDNA demonstrate a functional NADPH/Ca2+-dependent H2O2-generating activity. The immature Duox proteins had less activity than pig thyrocyte particulate fractions, and their activity depended on their primary structures. Human Duox2 seemed to be more active than human Duox1 but only half as active as its porcine counterpart. TPO co-transfection produced a slight increase in the enzymatic activity, whereas p22(phox), the 22-kDa subunit of the leukocyte NADPH oxidase, had no effect. In previous studies on the mechanism of H2O2 formation, it was shown that mature thyroid NADPH oxidase does not release O2*- but H2O2. Using a spin-trapping technique combined with electron paramagnetic resonance spectroscopy, we confirmed this result but also demonstrated that the partially glycosylated form of Duox2, located in the endoplasmic reticulum, generates superoxide in a calcium-dependent manner. These results suggest that post-translational modifications during the maturation process of Duox2 could be implicated in the mechanism of H2O2 formation by favoring intramolecular superoxide dismutation.