Copper,zinc superoxide dismutase activity evaluation using mercury microelectrodes

The activity of bovine Cu,Zn superoxide dismutase (SOD) was determined by steady-state voltammetry using mercury microelectrodes having close hemisphere shapes. The measurements were carried out in aerated aqueous solutions saturated with the surfactant triphenylphosphine oxide (TPO). The influence of pH on oxygen reduction process, either in the presence or in the absence of SOD, was studied over the range 7.5–12.3. Well-defined steady-state voltammetric waves, whose heights were reproducible within 2%, were obtained. A theoretical equation was derived for the calculation of the kinetic constant involved in the SOD-catalysed dismutation of the superoxide ion. The results obtained with the approach employed here agreed satisfactorily with those obtained by a dropping mercury electrode with a short dropping time.     

Concordance between breath test and histologic damage in Helicobacter pylori associated infections in infancy.

OBJECTIVE: the purpose of this study was to investigate the concordance between urea breath test values and the histological severity of gastric mucosa lesions in children. METHOD: forty children ranging in age from 3 to 17 years were examined endoscopically because of abdominal pain and positive breath test results. Histological status was determined by the intensity of the inflammatory infiltrate and by the depth of the damage. Histologically, four groups were considered: normal-appearing gastric mucosa (group 0), mild antrum gastritis (group 1), moderate antrum gastritis (group 2), and severe antrum gastritis (group 3). RESULTS: normal-appearing gastric mucosa was observed in 8 children with a mean breath test value of 44.07; mild chronic gastritis was observed in 17 children with a mean breath test value of 36.15; moderate gastritis was demonstrated in 10 children with a mean breath test value of 48.50, and severe gastritis was observed in 5 children with a mean breath test value of 52.31. CONCLUSION: we conclude that there is no concordance between urea breath test values and histological severity of gastric mucosa lesions in children.     

Light-sheet fluorescence microscopy for the in vivo study of microtubule dynamics in the zebrafish embryo

During its first hours of development, the zebrafish embryo presents a large microtubule array in the yolk region, essential for its development. Despite of its size and dynamic behavior, this network has been studied only in limited field of views or in fixed samples. We designed and implemented different strategies in Light Sheet Fluorescence microscopy for imaging the entire yolk microtubule (MT) network in vivo. These have allowed us to develop a novel image analysis from which we clearly observe a cyclical re-arrangement of the entire MT network in synchrony with blastoderm mitotic waves. These dynamics also affect a previously unreported microtubule array deep within the yolk, here described. These findings provide a new vision of the zebrafish yolk microtubules arrangement, and offers novel insights in the interaction between mitotic events and microtubules reorganization.     

Effects of dopamine and opioid receptor antagonism on the neural processing of social and nonsocial rewards

Rewards are a broad category of stimuli inducing approach behavior to aid survival. Extensive evidence from animal research has shown that wanting (the motivation to pursue a reward) and liking (the pleasure associated with its consumption) are mostly regulated by dopaminergic and opioidergic activity in dedicated brain areas. However, less is known about the neuroanatomy of dopaminergic and opioidergic regulation of reward processing in humans, especially when considering different types of rewards (i.e., social and nonsocial). To fill this gap of knowledge, we combined dopaminergic and opioidergic antagonism (via amisulpride and naltrexone administration) with functional neuroimaging to investigate the neurochemical and neuroanatomical bases of wanting and liking of matched nonsocial (food) and social (interpersonal touch) rewards, using a randomized, between-subject, placebo-controlled, double-blind design. While no drug effect was observed at the behavioral level, brain activity was modulated by the administered compounds. In particular, opioid antagonism, compared to placebo, reduced activity in the medial orbitofrontal cortex during consumption of the most valued social and nonsocial rewards. Dopamine antagonism, however, had no clear effects on brain activity in response to reward anticipation. These findings provide insights into the neurobiology of human reward processing and suggest a similar opioidergic regulation of the neural responses to social and nonsocial reward consumption.     

Mycobacterium tuberculosisexploits the CD95/CD95 ligand system of γ δ T cells to cause apoptosis

Vγ9/Vδ2⁺ T cells specifically recognize Mycobacterium tuberculosis in vitro and are precociously recruited in early mycobacterial lesions. Even if γ δ T cells are only fortuitously detected in granulomas or bronchoalveolar lavages of patients with active pulmonary tuberculosis, a role in shaping the mature α β T cell response against M. tuberculosis is substantiated. Here we provide a molecular explanation for this paradox: the engagement of the γ δ TCR by mycobacterial antigens induced the expression of CD95 ligand (CD95L) by chronically activated CD95⁺ /CD95L⁻ γ δ T lymphocytes. The receptor was functional, as CD95/CD95L interaction triggered the bystander death of CD95⁺ cells by apoptosis. Cell death was abolished by CD95-blocking antibodies. The transient accumulation at the site of infection of CD95L⁺ γ δ lymphocytes, capable of interacting with CD95⁺ leukocytes attracted by the response towards the pathogen, may determine the characteristics of the ensuing granulomatous disease.     

Adjuvant anthracycline therapy as a prognostic factor in metastatic breast cancer

Background. Prognostic factors in metastatic breast cancer continue to be identified. Previous adjuvant chemotherapy appeared to have poor prognosis in some studies but, despite this, the prior use of anthracyclines in the adjuvant setting has not been clearly established as an adverse prognostic factor once metastatic disease develops. Patients and methods. Patients (n=1,436) with stages I–IIIa breast cancer were surgically treated with/without radiotherapy and/or systemic adjuvant treatment. Of these, 297 patients who relapsed with metastatic disease constitute the sample population of this retrospective study. Survival, as a function of time since diagnosis of metastatic disease, was assessed in relation to the following factors: age, size of the primary tumor, grade, number of positive axillary nodes, type of surgery, type of adjuvant treatment administered, time to relapse, number of metastatic sites, presence of visceral metastases and type of treatment employed at the time of relapse. Results. In multivariable analysis three factors remained significant predictors of short survival time: more than 1 site of metastases (p=0.00003), shorter time to relapse (p=0.003) and the previous administration of anthracyclines as adjuvant therapy (p=0.005). Conclusions. The prior use of adjuvant anthracyclines, with other known clinical prognostic factors, confers a poorer outcome in metastatic disease, perhaps as a result of resistant clones selection or by induction of de novo resistance.     

Neuronal differentiation of chromaffin cells in vitro,induced by extremely low frequency magnetic fields or nerve growth factor: A histological and ultrastructural comparative study

The application of nerve growth factor (NGF) to primary adrenal medulla chromaffin cell cultures induces phenotypic changes characterized mainly by the presence of neurites. A similar effect has been seen when these cells are stimulated by extremely low frequency magnetic fields (ELFMF). In this study, newborn rat chromaffin cells were cultured and subjected to NGF or ELFMF in order to compare their histological and ultrastructural characteristics. Cells cultured in the presence of NGF developed cytoplasmic projections and their distal ends showed growth cones as well as filopodia. With scanning and transmission electron microscopy, an increased submembranous electron density was observed in the nuclei of cells as well as irregular, wavy neuritic projections with a moderate number of varicosities, as well as the prevalence of intermediate filaments among the cytoskeleton components. Cells stimulated with ELFMF presented straighter neuritic extensions with a greater number of varicosities. With the transmission electron microscope, numerous neurotubules were observed, both in the cell soma and in their neuritic extensions. In both groups, growth cones were clearly identified by their ultrastructural characteristics. The differences seen in the cytoskeleton of cells stimulated with NGF or ELFMF suggest differential stimulation mechanisms possibly determining the biochemical, electrophysiological, and morphological characteristics in both types of cell cultures. J. Neurosci. Res. 53:569–582, 1998. © 1998 Wiley-Liss, Inc.     

Effect of steroid receptors,pS2 and cathepsin D on the outcome of elderly breast cancer patients: An exploratory investigation

In 83 elderly breast cancer patients, oestrogen and progesterone receptors (ER, PgR), pS2 and cathepsin D (CathD) were evaluated for their possible prognostic role on disease-free survival (DFS). The biomarkers were determined on the same cytosol by using immunoradiometric assays, and the variables were considered on a continuous scale. Univariate analysis indicated a linear relationship between logarithmic hazard ratio (log(HR)) and the log(ER) and log(PgR) concentration, but a non-linear relationship between log(HR) and CathD. As regards pS2, there was no evidence of a relationship with log(HR). In multivariate analysis, log(ER) content did not have a significant prognostic role, whereas log(PgR) retained a significant prognostic role. As regards the predictive ability, log(PgR) was the best discriminator of outcome followed by CathD, whereas the contribution of log(ER) was negligible. In multivariate analysis, 2 models were considered: one with log(ER), pS2, CathD and the interaction between pS2 and CathD, and another with log(PgR), pS2, CathD and the interaction between pS2 and CathD. In the first model, log(ER) content did not have a significant prognostic role, whereas in the second model log(PgR) retained a significant prognostic role. Our findings indicate that the quantitative determination of pS2 and CathD, in addition to steroid receptors, on the same cytosolic fraction could be a complementary tool to describe all breast cancer patients rather than just the elderly and that the use of a continuous scale, instead of a simple dichotomous “status”, may improve the biological information supplied by the variables. Int. J. Cancer (Pred. Oncol.) 79:305–311, 1998. © 1998 Wiley-Liss, Inc.