Nerves and hydrogen peroxide:how old enemies become new friends

<正>ROS and nerves play together during the regeneration process:For many years,the role of reactive oxygen species(ROS)in neurobiology has mainly focused on its pathological implications in neurodegenerative diseases.Contrasting with this view,ROS were recently put forward as key positive signals for axon growth and repair,highlighting beneficial functions of ROS signalling in the vertebrate adult brain(Borquez et al.,2016).     

Structural and functional left ventricular impairment in subjects with chronic spinal cord injury and no overt cardiovascular disease

Context

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in subjects with long-term spinal cord injury (SCI). More specific recommendations for CVD prevention in this population are needed.

Methods

One hundred thirty male subjects (47 subjects with SCI and 83 able-bodied persons (ABPs), mean age 43.89 ± 1.9 and 45.44 ± 12.2 years; P = 0.48) underwent transthoracic echocardiography (TTE). The effects of age, weight, mean arterial pressure (MAP) and level of physical training on cardiac adaptations were evaluated through multiple regression analysis.

Results

In subjects with SCI, TTE revealed increased wall thickness (P < 0.05), lower E wave, E/A ratio and early diastolic myocardial relaxation velocity on Tissue Doppler Imaging (TDI) (P < 0.05) and higher systolic myocardial contraction velocity on TDI (0.10 ± 0.02 vs. 0.09 ± 0.02 m/seconds, P = 0.002) and peak systolic pressure to end-systolic volume ratio (3.62 ± 1.39 vs. 2.82 ± 0.90, P < 0.001) compared with ABPs. Aortic diameters were larger in subjects with SCI than ABPs. Differences remained statistically significant even after adjustment for age, weight, MAP, and level of physical training. Weight and age were found to be independent variables that substantially affected left ventricular structure and function in subjects with SCI.

Conclusions

Subjects with post-traumatic chronic SCI and no overt cardiovascular risk factors, exhibit initial left ventricular remodeling (as assessed by TTE) compared with ABPs. Lifestyle modifications, including regular physical exercise and weight control, should be implemented in all subjects with SCI, even at a very early stage, in order to reduce cardiovascular risk and prevent the development of CVD.     

Mechano-sensory organ regeneration in adults: the zebrafish lateral line as a model

In this report, we present a study of regeneration of the lateral line, a collection of mechano-sensory organ, in the adult zebrafish caudal fin. As all neuromasts are innervated by axon fibers, neuronal regeneration is a key issue in the regenerating process. We first show that support cells from the last neuromast adjacent to the amputation plane divide and migrate to colonize the blastema in order to reform the missing part of the lateral line. We then show that nerve re-growth takes place later than neuromast progenitor cell migration. We also provide evidence that new growth cones form at the amputation plane and subsequently follow the migrating placode-like structure to re-innervate regenerated neuromasts as they differentiate. Altogether, our observations indicate that caudal lateral line regeneration is not a mere recapitulation of the ontogenic process.     

Implication of type 3 deiodinase induction in zebrafish fin regeneration

Thyroid hormones are critical determinants of cellular differentiation. We used the zebrafish model to evaluate the involvement of thyroid hormones in regeneration processes after caudal fin amputation. We examined early events following fin amputation, i.e., blastema formation and nerve repair by growth cone formation. Here, we show that the abolition of thyroid gland activity by methimazole treatment had no effect on blastema formation, but slowed growth cone formation of the lateral line. Conversely, the addition of exogenous thyroid hormones enhanced growth cone formation without affecting blastema formation. However, amputation triggered a strong induction in the blastema of type 3 deiodinase mRNA and enzymatic activity, which degrades thyroid hormone (TH). We therefore blocked deiodinase activity with iopanoic acid (IOP) and saw a reduction in blastema formation, suggesting that local degradation of TH is permissive for cell proliferation in the blastema. The effect of IOP on the blastema required endogenous or exogenous TH. Our findings support a model in which local degradation of TH by type 3 deiodinase is permissive for epimorphic regeneration.     

Gender differences in the relationship between left ventricular size and ambulatory blood pressure in borderline hypertension: The HARVEST Study

AIM: To assess whether there are gender differences in cardiac adaptationto raised blood pressure levels in young subjects with borderlineto mild hypertension. METHODS AND RESULTS: In 499 18–45-year-old stage I hypertensive subjects (377men and 122 women) with a mean age of 33±9 years andoffice blood pressure of 146±11/94±6 mmHg, ambulatoryblood pressure monitoring in duplicate, echocardiography and24-h urinary catecholamines measurement were performed. RESULTS: The whole group was divided into quartiles of increasing daytimeblood pressure and differences in left ventricular echocardiographicdata were analysed in the two sexes separately. In men no leftventricular parameter differed across the quartiles, while inwomen left ventricular mass, posterior wall thickness and interventricularseptum thickness showed a clear tendency to increase with increasinglevels of systolic blood pressure. In multiple regression analysis,daytime systolic blood pressure explained only a small fractionof the variance in left ventricular parameters in men, whilein women daytime systolic blood pressure was a main determinantof left ventricular mass and posterior wall and septal thicknesses.Body weight explained most of the variance in all dimensionalparameters in men. In women weight was an important predictorof left ventricular mass and diameter, but was unrelated toleft ventricular posterior wall and septal thicknesses. CONCLUSIONS: Daytime systolic blood pressure is the most important predictorof left ventricular mass and geometry in pre-menopausal womenwith stage I hypertension, while in men left ventricular dimensionalindeces are chiefly explained by body weight.     

Immunoglobulinic fragments of urinary proteins in patients affected by acute pneumonopathies, lung cancer and tuberculosis (author's transl)

This study reports the immunoelectrophoretic analysis performed on 95 samples of urinary proteins. This analysis shows that in the majority of cases the migrant proteins in gamma position are F(ab) and Fc fragments, and free light chains with a molecular weight between 70,000 and 10,000. There is evidence of an increase in the immunoglobulinic fragments during inflammatory processes and their disappearance afterwards. This phenomenon proves that the elimination of these fragments evidences an increased synthesis of immunoglobulins and consequently also an increased catabolism.