The group IIb metal zinc (Zn) is an essential dietary component that can be found in protein rich foods such as meat, seafood and legumes. Thousands of genes encoding Zn binding proteins were ...identified, especially after the completion of genome projects, an indication that a great number of biological processes are Zn dependent. Imbalance in Zn homeostasis was found to be associated with several chronic diseases such as asthma, diabetes and Alzheimer's disease. As it is now evident for most nutrients, body Zn status results from the interaction between diet and genotype. Zn ions cross biological membranes with the aid of specialized membrane proteins, belonging to the ZRT/IRT-related Proteins (ZIP) and zinc transporters (ZnT) families. The ZIPs are encoded by the Slc39A gene family and are responsible for uptake of the metal, ZnTs are encoded by the Slc30A genes and are involved in intracellular traffic and/or excretion. Both ZnTs and Zips exhibit unique tissue-specific expression, differential responsiveness to dietary Zn deficiency and excess, as well as to physiological stimuli via hormones and cytokines. Intracellular Zn concentration is buffered by metallothioneins (MTs), a class of cytosolic protein with high affinity for metals. Scattered information is available on the role of proteins responsible for regulating Zn fluxes in the onset and progression of chronic diseases. This paper reviews reports that link Zn transporter genes, their allelic variants and/or expression profiles in the context of specific diseases. Further investigation in this direction is very important, since Zn imbalance can result not only from insufficient dietary intake, but also from impaired activity of proteins that regulate Zn metabolism, thus contributing to multifactorial diseases.
To better understand the mechanisms by which zinc deficiency induces epithelial cell death, studies were done of the effects of intracellular zinc depletion induced by the zinc chelator TPEN on ...apoptosis-related events in human malignant epithelial cell lines LIM1215 (colonic), NCI-H292 (bronchial), and A549 (alveolar type II). In TPEN-treated cells, depletion of zinc was followed by activation of caspase-3 (as demonstrated by enzymatic assay and Western blotting), DNA fragmentation, and morphologic changes. Increase in caspase-3 activity began 12 h after addition of TPEN, suggesting that zinc may suppress a step just before the activation of this caspase. Caspase-6, a mediator of caspase-3 processing, also increased, but later than caspase-3. Effects of TPEN on apoptosis were completely prevented by exogenous ZnSO4 and partially prevented by peptide caspase inhibitors. A critical substrate of caspase-3 may be the cell cycle regulator p21Waf1/Cip1, which was rapidly cleaved in TPEN-treated cells to a 15-kDa fragment before further degradation.
Non‐toxic agents that target intracellular signalling pathways in apoptosis may have potential therapeutic use in many diseases. One such agent is the transition metal Zn, a dietary cytoprotectant ...and anti‐oxidant, which stimulates cell proliferation and suppresses apoptosis. Zn is maintained in discrete subcellular pools that are critical for the functional and structural integrity of cells. The present review initially describes the current state of knowledge on the cellular biology of Zn, especially the critical free or loosely bound (labile) pools of Zn, which are thought to regulate apoptosis. We then review the evidence relating Zn to apoptosis, including studies from our laboratory showing potent synergy between intracellular Zn deficiency and the short chain fatty acid butyrate in induction of caspase activation and the downstream events of apoptosis. Our studies have also reported the suppressive effects of micromolar concentrations of Zn on caspase‐3 activation in cell‐free models. Other key issues that will be discussed include the identification of the putative molecular targets of Zn and the evidence that systemic changes in labile Zn levels are sufficient to alter susceptibility to apoptosis and lead to physiopathological changes in the human body. Finally, we propose that labile Zn may serve as a coordinate regulator of mitosis and apoptosis to regulate tissue growth.
Our previous study demonstrated that selective carotid baroreceptors activation decreases airway resistance. The aim of the present study was to evaluate the effect of carotid baroreceptor ...inactivation on the reflex change of respiratory resistance. Twenty healthy men aged between 20 and 25 were included in the study. Selective inactivation of carotid baroreceptors was induced by generating a positive pressure of 40 mmHg for 5 s in two capsules placed bilaterally on the neck over the bifurcation of the carotid arteries. The oscillatory method (Siregnost FD5, Siemens) was used to measure continuously respiratory resistance. Inactivation of carotid baroreceptors produced a short increase in respiratory resistance by 0.39 +/- 0.01(SE) mbar/l/s, i.e., 21.7% above the resting level. We conclude that in humans, carotid baroreceptors might have a background contribution to bronchodilator tone. This observation seems to be important for clinical situations of impairment of baroreflex function.
The mechanism responsible for the central baroreflex resetting with age are an area of limited knowledge. We previously demonstrated that in subjects aged above 50 the airway resistance did not ...change in response to baroreceptor activation, whereas in younger volunteers the airway resistance significantly decreased.
The aim of the present study was to evaluate the effect of carotid baroreceptor inactivation on the reflex change of respiratory resistance, in the course of aging.
80 healthy men, divided in four groups: aged 20-30 (Group I), 31-40 (Group II), 41-50 (Group III), and 51-60 (Group IV) were included in the study. The selective inactivation of carotid baroreceptors was induced by generating a positive pressure of 40 mmHg for 5 s in two capsules placed bilaterally on the neck over the bifurcation of the carotid arteries. The oscillatory method (Siregnost FD5, Siemens) was used to measure continuously respiratory resistance.
Inactivation of carotid baroreceptors produced a short increase in respiratory resistance by 0.38 +/- 0.01SE mbar/l/s, i.e., 21.7% above the resting level in Group I and by 0.25 +/- 0.01 mbar/l/s in Group II. In the two older groups (III and IV) respiratory resistance did not change in response to baroreceptors inactivation.
In humans aged above 40, carotid baroreceptors do not contribute to bronchodilator tone, which causes imbalance between the activities of upper airway and chest wall inspiratory muscles leading to a collapsing effect on the upper airway.
Abstract Background Response patterns to nivolumab differ from those seen with other approved targeted therapies. Objective To investigate the efficacy of nivolumab in previously treated patients ...with advanced renal cell carcinoma who were treated beyond (Response Evaluation Criteria In Solid Tumors) RECIST progression. Design, setting, and participants This was a subgroup analysis of patients treated with nivolumab in the phase 3 CheckMate 025 study. Patients continuing to tolerate therapy and exhibiting investigator-assessed clinical benefit were eligible to be treated beyond RECIST progression (TBP) and received therapy for ≥4 wk after first progression; patients not treated beyond RECIST progression (NTBP) received 0 wk to <4 wk of therapy after progression. Interventions Nivolumab 3 mg/kg intravenously every 2 wk. Results and limitations Of 406 nivolumab-treated patients, 316 (78%) progressed by RECIST criteria. Of those who progressed, 48% were TBP, 52% were NTBP. Before being TBP, objective response rate (95% confidence interval) was 20% (14–28) and 14% (9–21) in patients TBP and NTBP, respectively. Differences in clinical characteristics assessed at first progression between patients TBP versus NTBP included better Karnofsky performance status, less deterioration in Karnofsky performance status, shorter time to response, lower incidence of new bone lesions, and improved quality of life. Postprogression, 13% of all patients TBP (20/153) had ≥30% tumor burden reduction including patients with preprogression and postprogression tumor measurements ( n = 142) and complete/partial response (28%, 8/29), stable disease (6%, 3/47), and progressive disease (14%, 9/66) as their best response before being TBP. Incidence of treatment-related adverse events in patients TBP was lower after (59%) versus before (71%) progression. Limitations included potential bias from the nonrandomized nature of the analysis. Conclusions A subset of patients with advanced renal cell carcinoma and RECIST progression experienced tumor reduction postprogression with nivolumab, and had an acceptable safety profile. Clinical judgment remains essential when switching therapy. ClinicalTrials.gov Identifier: NCT01668784. Patient summary A subset of patients with advanced renal cell carcinoma and disease progression may continue to benefit from nivolumab treatment beyond progression as evidenced by tumor reduction postprogression and an acceptable safety profile.
Chronic lymphocytic leukemia lymphocytes were used to study mechanisms involved in apoptosis (programmed cell death). Apoptosis, which was determined by morphological changes including cell death and ...by internucleosomal DNA fragmentation, occurred during culture for 1 to 2 days in a portion of the cells from three of the four patients tested. Most of the cells underwent apoptosis and DNA fragmentation was greatly enhanced when cells were cultured in the presence of the microtubule inhibitor colchicine, the topoisomerase II inhibitor etoposide, or the glucocorticoid methylprednisolone. Tumor-promoting phorbol esters inhibited spontaneous DNA fragmentation and cell death including that induced by colchicine, etoposide, and methylprednisolone, indicating that they act on an event common to apoptosis caused by diverse stimuli. Phorbol esters probably act through protein phosphorylation, since they were effective at concentrations which modulated protein kinase C (PKC) and their action was prevented by H-7, which binds to and inactivates the catalytic site of PKC. In the absence of phorbol ester, H-7 itself induced some apoptosis. These findings implicate PKC in the suppression of apoptosis, but its precise role requires systematic investigation.
To determine associations between sicca symptoms, chronic rhinosinusitis (CRS) symptoms and asthma in a community survey.
Data was obtained from the Spring 2009 South Australian Health Omnibus Survey ...which sampled, via interviewer administered questionnaire, 3007 individuals aged 15 years and over whose socio-demographic distribution corresponded to South Australian population estimates. Respondents were asked a range of questions relating to the presence of persistent dry eyes or dry mouth, CRS and medically diagnosed nasal polyps and asthma. Relationships between symptoms were explored using maximum likelihood dependency tree analysis.
THE RESPECTIVE POPULATION PREVALENCES WERE: dry mouth (5.9%), dry eyes (8.6%), nasal polyps (3.8%), CRS (13.2%) and asthma (12.0%). The overall prevalence of sicca symptoms (dry eyes or dry mouth) was 12.4%. Dependency tree analysis revealed the expected symptom clustering between (1) sicca symptoms and their association with female gender and increasing age and (2) CRS, nasal polyps and asthma (one airway hypothesis). However there was also an association between dry eyes and CRS (OR 2.5, 95% CI 1.9, 3.4), which was in fact stronger than the association between CRS and asthma (OR 1.9, 95% CI 1.4, 2.5).
Sicca symptoms are common in the community. Our novel finding of a strong association between dry eyes and CRS suggests that further research into the relationship between airway inflammation and sicca symptoms is required. These findings may have particular relevance to Sjögren's syndrome (SS) in both its primary and secondary forms.
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