44,075 research outputs found
Sampling problems in the radiocarbon dating of old mortars and plasters with the "pure lime lumps" technique.
No full textSeveral scientific papers describe the radiocarbon dating of lime mortars and plasters [Folk and Valastro, 1976; Van Strydonck et al., 1992; Hale et al., 2003; Nawrocka et al., 2005] carried out using the 14C dating contained in the calcium carbonate precipitated during the hardening process of lime. As the content of 14C contained in the newly formed calcium carbonate reflects the 14C concentration in the atmosphere at the time of hardening, this material can be used for the radiocarbon dating of old mortars and plasters. Although the method is quite simple in its basis principle, relevant issues come from the contamination problems with other carbon sources. Grains of carbonate sand or underburned pieces of the same limestone used to produce the lime, that are originally mixed with the binder cannot be, in fact, completely removed from the mixtures. These materials do not contain radioactive carbon but behave as the carbonated lime during the analyses.
For overcoming this problem, over the past years, new techniques for the sample preparation have been developed and among these techniques, the so called “pure lime lumps” represents a fast and reliable method. The technique is based on the use of lumps of pure lime, very often embedded in old lime based mixtures as material for the radiocarbon dating. Because these lumps are made of pure lime any contamination problem is avoided. However, despite the remarkable results already achieved with this technique [Pesce et al., 2009; Pesce et al., 2012; Pesce et al., 2013], the sample collection is still a very important issue for a successful application of the radiocarbon dating.
This contribute describes the main sampling problems faced during a research on the accuracy and precision of the "pure lime lumps" technique, founded by the University of Genoa2 and carried out together by the University of Genoa and the and CEDAD in Italy and the University of Bath in United Kingdom
T Regulatory Lymphocytes Function Increased, by Induction Of Ho-1, Improves Type-1 Cardio-Renal Syndrome
No full textRationale: Type-1 cardio-renal syndrome (CRS) is characterized by an acute kidney dysfunction due to renal arteriolar vasoconstriction following an acute worsening of cardiac function. It is well know that HO-1 upregulation has a cardio protective and renoprotective function mediated by anti-oxidative, anti-inflammatory, anti-apoptotic and vasodilating effects. An alteration of T-lymphocyte-related immune response seems to be one of the potential mechanisms involved in type-1 CRS.
Objective: The aim of this study was to assess 1) if HO-1 upregulation could be a therapeutic target for type 1 CRS and 2) the role of T-lymphocytes in HO-1 induced effects on renal function in type 1 CRS.
Methods: Post-ischemic heart failure was induced by left anterior coronary artery ligation in C57Bl6 and SCID (T lymphocytes deficient) mice. Animals were divided into 4 groups: sham, myocardial infarction (MI), MI treated with HO-1 inducer cobalt protoporphyrin (CoPP) with and without the HO activity inhibitor stannous mesoporphyrin (SnMP). All mice underwent echocardiography (fractional area shortening, FAS) and renal Doppler sonography (intrarenal pulsatility index, PI) 30 days after surgery.
Results: Heart function was significantly reduced in MI groups (C57: FAS: sham 0.36±0.06, MI 0.26±0.04, p<0.05; SCID: FAS: sham 0.34±0.04, MI: 0.24±0.04, p<0.01) and PI was significantly increased in MI groups compared to sham groups (C57: PI: sham 0.98±0.05, MI: 1.12±0.11, p<0.05; SCID: PI: sham 0.72±0.08, MI 1.37±0.37, p<0.05). HO-1 induction improved heart function in both C57 and SCID mice but only in SCID mice was a significant improvement of renal vasoconstriction observed (SCID; PI: MI+CoPP 0.9±0.19 p<0.05). In SCID mice SnMP treatment reversed the effect of CoPP on heart function and renal vasoconstriction.
Conclusion: Our novel study showed that T lymphocyte mediated immunity is involved in type 1 CRS and upregulation of HO-1, in this setting, could be a therapeutic target for improving type 1 CRS.
Author Disclosures: P. Pesce: None. D. Sacerdoti: None. M. Boldrin: None. R. Rezzani: None. N.G. Abraham: None.
Key Words: Renal circulation • Heart failure • Immunologic factors • Oxidative stres
Heme-oxygenase-1 Induction Improves Type-1 Cardiorenal Syndrome Only In Mice With Impaired AngII-induced Lymphocyte Activation (SCID Mice)
No full textRational: The absence of lymphocyte activity protects SCID mice from AngII-induced hypertension facilitating blood pressure-induced sodium excretion, possibly via the stimulation of eNOS- and COX-2-dependent pathways. Type-1 cardiorenal syndrome (CRS-1), characterized by acute kidney dysfunction secondary to deterioration in cardiac function, is caused by renal arteriolar vasoconstriction, mediated by the activation of renin-angiotensin and sympathetic nervous systems (RAAS, SNS). Heme Oxygenase-1 (HO-1) induction improves renal function, but not renal vasoconstriction, in AngII-induced hypertension, and causes the desensitization of vascular smooth muscle to phenylephrine.
Objectives: We evaluated whether AngII resistant SCID mice develop CRS-1 as occurs in control mice, and the differential effects of HO1 induction on renal hemodynamics in CRS-1.
Methods: Post ischemic heart failure was induced in C57 and SCID mice by left anterior coronary artery ligation. Mice were divided in 4 groups: sham, myocardial infarction (MI), MI treated with cobalt protoporphyrin (CoPP), an inducer of HO-1, in the presence and absence of HO activity inhibitor, stannous mesoporphyrin (SnMP). All mice underwent echocardiography (ejection fraction, EF) and renal echoDoppler (arterial pulsatility index, K-PI) examination 30 days after surgery.
Results: EF was significantly reduced both in control and SCID mice after MI (C57: sham 0.60±0.07, MI 0.45±0.04, p<0.05; SCID: sham 0.60±0.06, MI: 0.46±0.1, p<0.01). K-PI was significantly increased in MI groups compared to sham groups (C57: sham 0.98±0.05, MI 1.12±0.11, p<0.05; SCID: sham 0.72±0.08, MI 1.37±0.37, p<0.05). HO1 induction improved renal vasoconstriction only in SCID mice (SCID K-PI: MI+CoPP 0.9±0.19 p<0.5çC57 K-PI: MI+CoPP 1.05±0.15, n.s.). In SCID mice SnMP reversed the effect of CoPP on renal vasoconstriction.
Conclusion: CRS-1 is similar in SCID and control mice and is associated with increased renal arterial resistance. HO-1 induction improves renal vasoconstriction only in SCID (AngII resistant) mice with CRS-1, suggesting that increased HO-1 activity cannot protect the kidney from AngII-induced lymphocyte activation, but only from SNS-induced vasoconstriction.
Author Disclosures: P. Pesce: None. D. Sacerdoti: None. S.R. Monu: None. K. Sodhi: None. M. Boldrin: None. N.G. Abraham: None.
Key Words: Angiotensin II • Renal circulation • Heart failur
HIV-1 Tat-induced diarrhea drives a glial inflammatory reaction to the central nervous system associated with a significant cognitive decline.
No full textAcquired immunodeficiency syndrome (AIDS)-associated gastrointestinal and cognitive dysfunctions are complications related to HIV infection that significantly increase the morbidity and mortality1.
HIV-1 Trans activating factor protein (Tat), by inducing mucosal damage, may reach the nerve part of the gut, the enteric nervous system (ENS), affecting its functions and resulting in a secretory diarrhea2. Since in the central nervous system (CNS) the glial cells are directly involved in mediating neurotoxic effects induced by HIV-1 Tat3, the possible role played by enteric glial cells (EGCs) to trigger and spread an HIV-1 Tat-induced neuroinflammatory response throughout the “gut-brain” axis was investigated.We tested our hypothesis that enteric glia is involved in HIV-1 Tat-induced diarrhea and cognitive dysfunctions to verify: (I) how the activation of the enteric glia modulates the diarrhea;(ii) if EGC-activation is localized at the intestinal level or it is associated with a signaling to the CNS; (iii) what is the pathway by which HIV-1 Tat signaling propagates from the periphery to the brain; (iv) if these events correlate with cognitive impairment. In eight-weeks-old Wistar male rats, HIV-1 Tat peptide (100 ng/ml) was injected into the lumen of the animal colon at day 1. In a subset of animals, HIV 1-Tat was administered immediately after lidocaine topic application in a single dose (0.03% w/v). In another group of animals, a single dose of bisacodyl (20 mg/Kg) was administrated orally by gavage. Animals were euthanatized at different time points (7, 12, 14 and 21 days) depending upon the scheduled experimental plan, and colon, thoracic and cervical spinal cord and brain were isolated to perform immunofluorescence, in situ hybridization and biochemical/molecular analyses. Finally, we investigated the memory skills of treated rats by the object recognition test. Our study demonstrates that a single colonic application of HIV-1 Tat induces an acute diarrhea that is at least partially modulated by the activation of glia cells in the submucosal plexus. This local response is able to trigger and activate glia cells in the spinal cord and brain cortex through the expression of Cx43, that results in an inflammatory reaction in the brain and that is associated with a significant cognitive decline in treated rats
[Indications for and results of extra-anatomic bypass in obstructive arteriopathies of the lower limbs].
No full textEnergy balance and active lifestyle: potential mediators of health and quality of life perception in aging
No full textThe relationship between aging and perception of health and quality of life is complex and its mediation mechanisms need to be further explored. The purpose of this study was to investigate the mediating effects of total energy expenditure and intake, body mass, and body image dissatisfaction on the relationship between age and perception of health and quality of life. Forty-two senior athletes, 55 physically active, and 61 sedentary individuals (aged 55-84 years) were evaluated for total energy expenditure (EE), energy intake (EI), body mass index (BMI), absolute Body Dissatisfaction Index (BDIabx), and physical (PCS) and mental (MCS) health and quality of life perception. Multiple mediation analyses were applied to assess the relationship between age and PCS and MCS indices, through the mediators EE, EI, BMI, and BDIabx. For MCS, but not for PSC, the mediation analysis showed: (a) a direct effect of age; (b) a mediation path through EE, EI, BMI, and BDIabx; and (c) a positive total effect. The combination of positive and negative mediating effects influencing the mental health perception underlined that with advancing age, the maintenance of high levels of energy expenditure through physical activity could positively impact body image satisfaction and, in turn, mental health
La chiesa di S. Nicolò di Capodimonte (Camogli - Genova): dal cantiere di diagnosi al progetto di restauro
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