460 research outputs found
Comparison of HIV prevalence estimates from antenatal care surveillance and population-based surveys in sub-Saharan Africa
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In countries with generalized epidemics, national estimates of HIV prevalence levels and trends in the adult population are generally derived indirectly from surveillance of pregnant women attending selected antenatal care (ANC) clinics. ANC data however, come from a subset of the population and may not represent the true population prevalence. To compare HIV seroprevalence estimates obtained from ANC sentinel surveillance surveys in Ethiopia, Kenya, Malawi, Tanzania, and Uganda with those from population-based Demographic and Health Surveys (DHS) and AIDS Indicator Surveys (AIS). Geographic information system (GIS) methods were used to map sentinel surveillance sites and DHS/AIS survey clusters within a 15 km radius of the ANC\ud
surveillance sites. National DHS/AIS HIV prevalence estimates for women were compared with national prevalence estimates from ANC surveillance. DHS/AIS HIV prevalence estimates for women residing within 15 km of ANC sites were compared to those from ANC surveillance. These comparisons were also stratified by current pregnancy status, experience of recent child birth, and receiving ANC for the last birth. In four of the five countries, national DHS/AIS estimates of HIV prevalence were lower than the ANC surveillance estimates. Comparing women in the catchment areas of the ANC sites, the DHS/AIS estimates were similar to ANC surveillance estimates. ANC estimates were higher for younger women than DHS/AIS estimates for women in ANC catchment areas, but lower at older ages. In all cases, urban prevalence was higher than rural prevalence, but there were no consistent patterns by education. ANC surveillance surveys tend to overestimate HIV prevalence compared to prevalence among women in the general population in DHS/AIS surveys. However, the ANC and DHS/AIS estimates are similar when restricted to women residing in catchment areas of ANC sites. Patterns by age and urban/rural residence suggest possible bias in the ANC estimates.\u
Mitochondrial exchanger NCLX plays a major role in the intracellular Ca(2+) signaling, gliotransmission, and proliferation of astrocytes
Mitochondria not only provide cells with energy, but are central to Ca(2+) signaling. Powered by the mitochondrial membrane potential, Ca(2+) enters the mitochondria and is released into the cytosol through a mitochondrial Na(+)/Ca(2+) exchanger. We established that NCLX, a newly discovered mitochondrial Na(+)/Ca(2+) exchanger, is expressed in astrocytes isolated from mice of either sex. Immunoblot analysis of organellar fractions showed that the location of NCLX is confined to mitochondria. Using pericam-based mitochondrial Ca(2+) imaging and NCLX inhibition either by siRNA or by the pharmacological blocker CGP37157, we demonstrated that NCLX is responsible for mitochondrial Ca(2+) extrusion. Suppression of NCLX function altered cytosolic Ca(2+) dynamics in astrocytes and this was mediated by a strong effect of NCLX activity on Ca(2+) influx via store-operated entry. Furthermore, Ca(2+) influx through the store-operated Ca(2+) entry triggered strong, whereas ER Ca(2+) release triggered only modest mitochondrial Ca(2+) transients, indicating that the functional cross talk between the plasma membrane and mitochondrial domains is particularly strong in astrocytes. Finally, silencing of NCLX expression significantly reduced Ca(2+)-dependent processes in astrocytes (i.e., exocytotic glutamate release, in vitro wound closure, and proliferation), whereas Ca(2+) wave propagation was not affected. Therefore, NCLX, by meditating astrocytic mitochondrial Na(+)/Ca(2+) exchange, links between mitochondria and plasma membrane Ca(2+) signaling, thereby modulating cytoplasmic Ca(2+) transients required to control a diverse array of astrocyte functions
Analysis of the correlations between oxidative stress, gelatinases and their tissue inhibitors in the human subjects with obstructive sleep apnea syndrome
Obstructive sleep apnea syndrome (OSAS) is commonly associated with endothelial dysfunction, atherosclerosis and cardiovascular disorders. On the basis of this observation, our aim was to examine the oxidative status and the matrix metalloproteases (MMP) profile in a group of subjects with OSAS. We enrolled 48 subjects with OSAS defined after a 1-night cardiorespiratory sleep study, who were subsequently subdivided in two subgroups according to the severity of OSAS (low grade = L-OSAS; high grade= H-OSAS). We measured the parameters of oxidative stress, such as lipid peroxidation, protein oxidation, total antioxidant status (TAS), nitric oxide metabolites (NOx), and the plasma concentrations of the gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2). We found a significant impairment of oxidative status in H-OSAS compared to L-OSAS and higher plasma levels of MMP-9 and TIMP-1 in H-OSAS compared to L-OSAS. In this study we observed a positive correlation between TBARS and MMP-9, a positive correlation between PC and MMP-9, and a negative correlation between NOx and MMP-9, especially in the whole group of OSAS subjects. These data underline how strong interrelationships among some parameters of the oxidative stress, in particular those reflecting lipid peroxidation, protein oxidation and NOx, and MMP-9 are evident in OSAS subjects. All these information may be useful in the clinical practice keeping in mind the cardiovascular complications generally accompanying the obstructive sleep apnea syndrome
Erythrocyte deformability, plasma lipid peroxidation and plasma protein oxidation in a group of OSAS subjects
Considering that obstructive sleep apnea syndrome (OSAS) is usually associated with endothelial dysfunction, atherosclerosis and cardiovascular disorders, our aim was to examine the erythrocyte deformability and the oxidative status in a group of OSAS subjects. We consecutively enrolled 48 subjects with OSAS defined after a 1-night cardiorespiratory sleep study, subsequently subdivided according to the apnea/hypopnea index (AHI) value in two subgroups: Low (L = 21 subjects with AHI30). We evaluated the erythrocyte deformability, expressed as elongation index (EI) and the parameters of the oxidative status, such as lipid peroxidation (expressed as thiobarbituric acid-reactive substances TBARS) and protein oxidation (measured as carbonyl groups PC). In the entire group and in the two subgroups of OSAS subjects we found a decreased erytrocyte deformability at all shear stresses, not correlated with the plasmatic oxidative stress nor with the polysomnographic parameters. Lipid peroxidation was increased in the whole group and in the H subgroup of OSAS while protein oxidation showed a different trend. As in OSAS the osmotic fragility and the metabolism of the red cells seem to be not impaired, the oxidative damage to the red cell membrane proteins might be responsible for the reduced erythrocyte deformability. This rheological alteration, in addition to the increase in whole blood and plasma viscosity and to the erythrocyte hyperaggregation, could influence the microcircolatory profile in OSAS subjects
Lipid peroxidation and protein oxidation are related to the severity of OSAS
OBJECTIVE: Obstructive sleep apnea syndrome (OSAS) is associated with elevated cardiovascular morbidity and mortality. Considering that oxidative stress is involved in endothelial dysfunction and atherosclerosis development, our aim was to examine lipid peroxidation and protein oxidation, two parameters of oxidative status, in a group of subjects with OSAS. PATIENTS AND METHODS: We consecutively enrolled 48 patients (36 men and 12 women; mean age 49.7\ub114.6 yrs) with OSAS, subsequently subdivided according to the apnea/hy-popnea index (AHI) value in two subgroups: Low (L= 21 subjects with AHI30). We examined lipid peroxidation, expressed as TBARS, and protein oxidation, measured as carbonyl groups in plasma samples from fasting venous blood. RESULTS: We observed that TBARS and car-bonyl groups were significantly higher in subjects with AHI > 30 in comparison with the L subgroup and the whole group of OSAS subjects. In addition, we found that these parameters were positively correlated with neck and waist circumference, with the AHI value and with the oxygen desaturation index, and negatively correlated with the mean oxygen saturation. CONCLUSIONS: Lipid peroxidation and protein oxidation in OSAS patients are significantly correlated with the severity of the disease
Protamine-like proteins have bactericidal activity. The first evidence in Mytilus galloprovincialis.
The major acid-soluble protein components of the mussel Mytilus galloprovincialis sperm chromatin consist of the protamine-like proteins PL-II, PL-III and PL-IV, an intermediate group of sperm nuclear basic proteins between histones and protamines. The aim of this study was to investigate the bactericidal activity of these proteins since, to date, there are reports on bactericidal activity of protamines and histones, but not on protamine-like proteins. We tested the bactericidal activity of these proteins against Gram-positive bacteria: Enterococcus faecalis and two different strains of Staphylococcus aureus, as well as Gram-negative bacteria: Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhmurium, Enterobacter aerogenes, Enterobacter cloacae, and Escherichia coli. Clinical isolates of the same bacterial species were also used to compare their sensitivity to these proteins. The results show that Mytilus galloprovincialis protamine-like proteins exhibited bactericidal activity against all bacterial strains tested with different minimum bactericidal concentration values, ranging from 15.7 to 250 µg/mL. Furthermore, these proteins were active against some bacterial strains tested that are resistant to conventional antibiotics. These proteins showed very low toxicity as judged by red blood cell lysis and viability MTT assays and seem to act both at the membrane level and within the bacterial cell. We also tested the bactericidal activity of the product obtained from an in vitro model of gastrointestinal digestion of protamine-like proteins on a Gram-positive and a Gram-negative strain, and obtained the same results with respect to undigested protamine-like proteins on the Gram-positive bacterium. These results provide the first evidence of bactericidal activity of protamine-like-proteins
La produzione di ceramica da mensa a Solunto: un esempio di continuit\ue0 tecnologica dall\u2bcet\ue0 arcaica a quella ellenistico-romana.
Solunto is one of the most important Phoenician-Punic colonies of north-western Sicily. Archaeometric researches carried
out in the last years ascertained a local production of transport amphorae during Archaic and Classic age (7th-5th century
B.C.) through mineralogical, petrographical and chemical analysis of ceramic samples, kiln refuses and local raw materials
(clays and alluvial sands). In connection with these earliest works, the present paper was focused on some specific forms
of fine-tempered table ware of Archaic age and/or Classic-Hellenistic age. This pottery has been recurrently brought to light
in Solunto and it is furthermore suspected to be, at least to some extent, a local reproduction. Thus a representative number
of samples corresponding in style and morphology to Greek-colonial productions were subjected to thin-section and chemical
analysis. Simultaneously, the same analytical routine was applied to an Hellenistic black-gloss ware form (Campana A), the
plate classified as Lamboglia 36, considering a number of samples coming from Solunto as well as from others close centers.
In both the cases the comparative elaboration of petrographic and chemical data concerning the ceramic samples and local
raw clays let us to distinguish between the products made in the Solunto\u2bcs kilns and the imports from Greece or the Greek
colony of Himera or from the Gulf of Naples area (for the black-gloss ware samples). Therefore, a durability of the
manufacture crosswise more than four centuries was demonstrated for the ceramic kilns which were working at Solunto,
which were able to reproduce several fine ware forms testifying an high technological level
Gelatinases and their tissue inhibitors in a group of subjects with obstructive sleep apnea syndrome
Obstructive sleep apnea syndrome (OSAS) is associated with an elevated risk of cardiovascular events and stroke. Matrix metalloproteinases (MMPs) are endopeptidases involved in extracellular matrix degradation and then in the development and progression of cardiovascular diseases. Our aim was to evaluate plasma levels of gelatinases (MMP-2 and MMP-9) and their tissue inhibitors (TIMP-1 and TIMP-2) in a group of subjects with OSAS. We enrolled 48 subjects (36 men and 12 women; mean age 49.7 \ub1 14.68 yrs) with OSAS diagnosed with a 1-night cardiorespiratory study and then we subdivided these subjects into two subgroups according to the apnea/hypopnea index (AHI): Low (L = 21 subjects with AHI <30) and High (H = 27 subjects with AHI >30). We measured plasma concentration of the gelatinases and their inhibitors using ELISA kits. We observed a significant increase in plasma concentration of MMP-9, MMP-2, TIMP-1 and TIMP-2 in the entire group of OSAS subjects and in the two subgroups, with higher levels in the H in comparison with the L subgroup. In the whole group of OSAS subjects we also noted a significant decrease in MMP-9/TIMP-1 ratio in comparison with normal controls. Only MMP-9 was significantly correlated with the severity of the disease, expressed as AHI, with the oxygen desaturation index and also with the mean oxygen saturation. MMPs pattern is altered in OSAS and significantly influenced by the severity of the disease; it probably contributes to the vascular remodeling that leads to the atherosclerotic disease and cardiovascular complications
Standardisation of elemental analytical techniques applied to provenance studies of archaeological ceramics: an inter laboratory calibration study
Chemical analysis is a well-established procedure for the provenancing of archaeological ceramics. Various analytical techniques are routinely used and large amounts of data have been accumulated so far in data banks. However, in order to exchange results obtained by different laboratories, the respective analytical procedures need to be tested in terms of their inter-comparability. In this study, the schemes of analysis used in four laboratories that are involved in archaeological pottery studies on a routine basis were compared. The techniques investigated were neutron activation analysis (NAA), X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). For this comparison series of measurements on different geological standard reference materials (SRM) were carried out and the results were statistically evaluated. An attempt was also made towards the establishment of calibration factors between pairs of analytical setups in order to smooth the systematic differences among the results
Nitric oxide metabolites (nitrite and nitrate) in several clinical condition
We determined the concentration of nitric oxide metabolites (NO2-+ NO3-), expressed as NOx, in several clinical conditions. Regarding this, we have examined 25 subjects with arterial hypertension, 41 subjects with chronic kidney disease in conservative treatment, 106 subjects with metabolic syndrome subdivided according to the presence (n=43) or not (n=63) of diabetes mellitus, 48 subjects with obstructive sleep apnea syndrome (OSAS),14 women with systemic sclerosis complicated with Raynaud's phenomenon, 42 dialyzed subjects and 105 young subjects with acute myocardial infarction (AMI). In subjects with arterial hypertension, chronic kidney disease, metabolic syndrome, systemic sclerosis, as well as, in dialyzed and AMI subjects, we found at baseline a NOx increase. In dyalized subjects after a standard dialysis session, we observed a decrease in NOx. The increase in NOx in juvenile AMI was significantly influenced by cigarette smoking and less by cardiovascular risk factors and the extent of coronary lesions; at 3 and 12 months later than the initial event, we observed a decrease of NOx that remains significantly higher than the control group. In subjects with OSAS no difference in NOx was noted in comparison with normal controls, although their subdivision according to the apnea/hypopnea index operates a clear distinction regarding NOx concentration
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