884 resultados para The Early Permian
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Abstract Background Clinical and experimental data suggest that the inflammatory response is impaired in diabetics and can be modulated by insulin. The present study was undertaken to investigate the role of insulin on the early phase of allergic airway inflammation. Methods Diabetic male Wistar rats (alloxan, 42 mg/Kg, i.v., 10 days) and controls were sensitized by s.c. injection of ovalbumin (OA) in aluminium hydroxide 14 days before OA (1 mg/0.4 mL) or saline intratracheal challenge. The following analyses were performed 6 hours thereafter: a) quantification of interleukin (IL)-1β, tumor necrosis factor (TNF)-α and cytokine-induced neutrophil chemoattractant (CINC)-1 in the bronchoalveolar lavage fluid (BALF) by Enzyme-Linked Immunosorbent Assay, b) expression of E- and P- selectins on lung vessels by immunohistochemistry, and c) inflammatory cell infiltration into the airways and lung parenchyma. NPH insulin (4 IU, s.c.) was given i.v. 2 hours before antigen challenge. Results Diabetic rats exhibited significant reduction in the BALF concentrations of IL-1β (30%) and TNF-α (45%), and in the lung expression of P-selectin (30%) compared to non-diabetic animals. This was accompanied by reduced number of neutrophils into the airways and around bronchi and blood vessels. There were no differences in the CINC-1 levels in BALF, and E-selectin expression. Treatment of diabetic rats with NPH insulin, 2 hours before antigen challenge, restored the reduced levels of IL-1β, TNF-α and P-selectin, and neutrophil migration. Conclusion Data presented suggest that insulin modulates the production/release of TNF-α and IL-1β, the expression of P- and E-selectin, and the associated neutrophil migration into the lungs during the early phase of the allergic inflammatory reaction.
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Severe Combined Immunodeficiency (SCID) is one of the most severe forms of primary immunodeficiency (PID). Complications of BCG vaccination, especially disseminated infection and its most severe forms, are known to occur in immunodeficient patients, particularly in SCID. A carefully taken family history before BCG injection as well as delaying vaccination if PID is suspected could be a simple and effective method to avoid inappropriate vaccination of an immunodeficient child in some cases until the prospect of newborn screening for SCID has been fully developed. We describe a patient with a very early diagnosis of SCID, which was suspected on the basis of the previous death of two siblings younger than one year due to severe complications secondary to the BCG vaccine. We suggest that a family history of severe or fatal reactions to BCG should be included as a warning sign for an early diagnosis of SCID.
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Aim: To evaluate the early response to treatment to an antiangiogenetic drug (sorafenib) in a heterotopic murine model of hepatocellular carcinoma (HCC) using ultrasonographic molecular imaging. Material and Methods: the xenographt model was established injecting a suspension of HuH7 cells subcutaneously in 19 nude mice. When tumors reached a mean diameter of 5-10 mm, they were divided in two groups (treatment and vehicle). The treatment group received sorafenib (62 mg/kg) by daily oral gavage for 14 days. Molecular imaging was performed using contrast enhanced ultrasound (CEUS), by injecting into the mouse venous circulation a suspension of VEGFR-2 targeted microbubbles (BR55, kind gift of Bracco Swiss, Geneve, Switzerland). Video clips were acquired for 6 minutes, then microbubbles (MBs) were destroyed by a high mechanical index (MI) impulse, and another minute was recorded to evaluate residual circulating MBs. The US protocol was repeated at day 0,+2,+4,+7, and +14 from the beginning of treatment administration. Video clips were analyzed using a dedicated software (Sonotumor, Bracco Swiss) to quantify the signal of the contrast agent. Time/intensity curves were obtained and the difference of the mean MBs signal before and after high MI impulse (Differential Targeted Enhancement-dTE) was calculated. dTE represents a numeric value in arbitrary units proportional to the amount of bound MBs. At day +14 mice were euthanized and the tumors analyzed for VEGFR-2, pERK, and CD31 tissue levels using western blot analysis. Results: dTE values decreased from day 0 to day +14 both in treatment and vehicle groups, and they were statistically higher in vehicle group than in treatment group at day +2, at day +7, and at day +14. With respect to the degree of tumor volume increase, measured as growth percentage delta (GPD), treatment group was divided in two sub-groups, non-responders (GPD>350%), and responders (GPD<200%). In the same way vehicle group was divided in slow growth group (GPD<400%), and fast growth group (GPD>900%). dTE values at day 0 (immediately before treatment start) were higher in non-responders than in responders group, with statistical difference at day 2. While dTE values were higher in the fast growth group than in the slow growth group only at day 0. A significant positive correlation was found between VEGFR-2 tissue levels and dTE values, confirming that level of BR55 tissue enhancement reflects the amount of tissue VEGF receptor. Conclusions: the present findings show that, at least in murine experimental models, CEUS with BR55 is feasable and appears to be a useful tool in the prediction of tumor growth and response to sorafenib treatment in xenograft HCC.
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There is an urgent need to improve the performance of urine cytology for the diagnosis of bladder cancer. In preliminary studies, telomerase activity evaluated by telomeric repeat amplification protocol (TRAP) assay and chromosomal aneuploidy detected by fluorescence in situ hybridization (FISH) in the diagnosis of bladder cancer have produced important results. Urine cell-free (UCF) DNA has also been proposed as a potential marker for early bladder cancer diagnosis. In the first study the diagnostic performance of TRAP assay and FISH analysis was assessed, while the second study evaluated the potential role of UCF DNA integrity in early bladder cancer diagnosis. In the first cross-sectional study, 289 consecutive patients who presented with urinary symptoms underwent cystoscopy and cytology evaluation. In the second study, UCF DNA was isolated from 51 bladder cancer patients, 46 symptomatic patients, and 32 healthy volunteers. c-Myc, BCAS1 and HER2 gene sequences longer than 250 bp were quantified by real time PCR to verify UCF DNA integrity. In the first study, sensitivity and specificity were 0.39 and 0.83, respectively, for cytology; 0.66 and 0.72 for TRAP; 0.78 and 0.60 for the cytology and TRAP combination; 0.78 and 0.78 for the cytology, TRAP and FISH combination; and 0.65 and 0.93 for the TRAP and FISH combination. In the second study, at the best cutoff of 0.1 ng/µl, UCF DNA integrity analysis showed a sensitivity of 0.73 and a specificity of 0.84 in healthy individuals and 0.83 in symptomatic patients. The preliminary results suggest that these biomarkers could potentially be used for the early diagnosis of bladder cancer, especially in high-risk populations (e.g, symptomatic individuals exposed to occupational risk) who may benefit from the use of noninvasive diagnostic tests in terms of cost-benefit.
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Tonalite-trondhjemite-granodiorite (TTG) gneisses form up to two-thirds of the preserved Archean continental crust and there is considerable debate regarding the primary magmatic processes of the generation of these rocks. The popular theories indicate that these rocks were formed by partial melting of basaltic oceanic crust which was previously metamorphosed to garnet-amphibolite and/or eclogite facies conditions either at the base of thick oceanic crust or by subduction processes.rnThis study investigates a new aspect regarding the source rock for Archean continental crust which is inferred to have had a bulk compostion richer in magnesium (picrite) than present-day basaltic oceanic crust. This difference is supposed to originate from a higher geothermal gradient in the early Archean which may have induced higher degrees of partial melting in the mantle, which resulted in a thicker and more magnesian oceanic crust. rnThe methods used to investigate the role of a more MgO-rich source rock in the formation of TTG-like melts in the context of this new approach are mineral equilibria calculations with the software THERMOCALC and high-pressure experiments conducted from 10–20 kbar and 900–1100 °C, both combined in a forward modelling approach. Initially, P–T pseudosections for natural rock compositions with increasing MgO contents were calculated in the system NCFMASHTO (Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–TiO2) to ascertain the metamorphic products from rocks with increasing MgO contents from a MORB up to a komatiite. A small number of previous experiments on komatiites showed the development of pyroxenite instead of eclogite and garnet-amphibolite during metamorphism and established that melts of these pyroxenites are of basaltic composition, thus again building oceanic crust instead of continental crust.rnThe P–T pseudosections calculated represent a continuous development of their metamorphic products from amphibolites and eclogites towards pyroxenites. On the basis of these calculations and the changes within the range of compositions, three picritic Models of Archean Oceanic Crust (MAOC) were established with different MgO contents (11, 13 and 15 wt%) ranging between basalt and komatiite. The thermodynamic modelling for MAOC 11, 13 and 15 at supersolidus conditions is imprecise since no appropriate melt model for metabasic rocks is currently available and the melt model for metapelitic rocks resulted in unsatisfactory calculations. The partially molten region is therfore covered by high-pressure experiments. The results of the experiments show a transition from predominantly tonalitic melts in MAOC 11 to basaltic melts in MAOC 15 and a solidus moving towards higher temperatures with increasing magnesium in the bulk composition. Tonalitic melts were generated in MAOC 11 and 13 at pressures up to 12.5 kbar in the presence of garnet, clinopyroxene, plagioclase plus/minus quartz (plus/minus orthopyroxene in the presence of quartz and at lower pressures) in the absence of amphibole but it could not be explicitly indicated whether the tonalitic melts coexisting with an eclogitic residue and rutile at 20 kbar do belong to the Archean TTG suite. Basaltic melts were generated predominantly in the presence of granulite facies residues such as amphibole plus/minus garnet, plagioclase, orthopyroxene that lack quartz in all MAOC compositions at pressures up to 15 kbar. rnThe tonalitic melts generated in MAOC 11 and 13 indicate that thicker oceanic crust with more magnesium than that of a modern basalt is also a viable source for the generation of TTG-like melts and therefore continental crust in the Archean. The experimental results are related to different geologic settings as a function of pressure. The favoured setting for the generation of early TTG-like melts at 15 kbar is the base of an oceanic crust thicker than existing today or by melting of slabs in shallow subduction zones, both without interaction of tonalic melts with the mantle. Tonalitic melts at 20 kbar may have been generated below the plagioclase stability by slab melting in deeper subduction zones that have developed with time during the progressive cooling of the Earth, but it is unlikely that those melts reached lower pressure levels without further mantle interaction.rn
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The advent of highly active antiretroviral therapy (HAART) in 1996 led to a decrease in the incidence of Kaposi's sarcoma (KS) and non-Hodgkin's lymphoma (NHL), but not of other cancers, among people with HIV or AIDS (PWHA). It also led to marked increases in their life expectancy.
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The mechanism underlying the mineralization of bone is well studied and yet it remains controversial. Inherent difficulties of imaging mineralized tissues and the aqueous solubility of calcium and phosphate, the 2 ions which combine to form bone mineral crystals, limit current analyses of labile diffusible, amorphous, and crystalline intermediates by electron microscopy. To improve the retention of calcium and phosphorus, we developed a pseudo nonaqueous processing approach and used it to characterize biomineralization foci, extracellular sites of hydroxyapatite deposition in osteoblastic cell cultures. Since mineralization of UMR106-01 osteoblasts is temporally synchronized and begins 78 h after plating, we used these cultures to evaluate the effectiveness of our method when applied to cells just prior to the formation of the first mineral crystals. Our approach combines for the first time 3 well-established methods with a fourth one, i.e. dry ultrathin sectioning. Dry ultrathin sectioning with an oscillating diamond knife was used to produce electron spectroscopic images of mineralized biomineralization foci which were high-pressure frozen and freeze substituted. For comparison, cultures were also treated with conventional processing and wet sectioning. The results show that only the use of pseudo nonaqueous processing was able to detect extracellular sites of early calcium and phosphorus enrichment at 76 h, several hours prior to detection of mineral crystals within biomineralization foci.
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This thesis assesses relationships between vegetation and topography and the impact of human tree-cutting on the vegetation of Union County during the early historical era (1755-1855). I use early warrant maps and forestry maps from the Pennsylvania historical archives and a warrantee map from the Union County courthouse depicting the distribution of witness trees and non-tree surveyed markers (posts and stones) in early European settlement land surveys to reconstruct the vegetation and compare vegetation by broad scale (mountains and valleys) and local scale (topographic classes with mountains and valleys) topography. I calculated marker density based on 2 km x 2 km grid cells to assess tree-cutting impacts. Valleys were mostly forests dominated by white oak (Quercus alba) with abundant hickory (Carya spp.), pine (Pinus spp.), and black oak (Quercus velutina), while pine dominated what were mostly pine-oak forests in the mountains. Within the valleys, pine was strongly associated with hilltops, eastern hemlock (Tsuga canadensis) was abundant on north slopes, hickory was associated with south slopes, and riparian zones had high frequencies of ash (Fraxinus spp.) and hickory. In the mountains, white oak was infrequent on south slopes, chestnut (Castanea dentata) was more abundant on south slopes and ridgetops than north slopes and mountain coves, and white oak and maple (Acer spp.) were common in riparian zones. Marker density analysis suggests that trees were still common over most of the landscape by 1855. The findings suggest there were large differences in vegetation between valleys and mountains due in part to differences in elevation, and vegetation differed more by topographic classes in the valleys than in the mountains. Possible areas of tree-cutting were evenly distributed by topographic classes, suggesting Europeans settlers were clearing land and harvesting timber in most areas of Union County.
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To assess the pattern of early bacterial colonization at implants and teeth in patients with a history of chronic periodontitis compared with a group of healthy subjects. Furthermore, the presence of host-derived markers at teeth and implants in the two subject groups was determined.