433 resultados para (0001) sapphire substrates
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Background/aims To compare two intraocular irrigating solutions, Balanced Salt Solution Plus (BSS Plus) versus Lactated Ringer`s (Ringer), for the preservation of corneal integrity after phacoemulsification. Methods 110 patients undergoing phacoemulsification were randomised to either BSS Plus (n = 55) or Ringer (n = 55) as the irrigating solution. Patients were examined at baseline and at 1, 8, 15, 30 and 60 days postoperatively. Evaluations included specular microscopy to evaluate endothelial cell density (ECD) and endothelial cell size variability (CV), and corneal pachymetry for central corneal thickness (CCT) measurement. Results Groups were well balanced regarding baseline ECD, CV and CCT (p>0.05). There was no statistically significant difference between ECD reduction in group BSS Plus 13.1 +/- 2.0% and Ringer 9.2 +/- 1.9% (p<0.05) at day 60 or in any study visit. There was no statistically significant difference between CV increase in group BSS Plus 23.0 +/- 3.0% and Ringer 20.2 +/- 4.0% (p<0.05) at day 60 or in any study visit. CCT was significantly increased (p<0.05) at 1, 8, 15 and 30 days postoperatively, returning to baseline at 60 days in both groups. There was no significant difference in CCT increase in both groups at any visit. Interestingly, there were statistically significant correlations between ECD loss and phacoemulsification time (p<0.0001) and ECD loss and irrigation solution volume (p<0.0001) in the Ringer group, but not in the BSS Plus group. Conclusions Ringers solution was similar to BSS Plus for corneal preservation in atraumatic cataract surgery. However, our study demonstrates that there is a trend towards lower postoperative endothelial cell density for surgeries with longer phacoemulsification time and higher irrigation volumes if Ringer is used.
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Aims: To compare the amount of intraoperative intraocular bleeding in patients with diabetes with macula-involving tractional retinal detachment (TRD) undergoing pars plana vitrectomy (PPV) with and without preoperative intravitreal bevacizumab (IVB) injection. Methods: An institutional study was carried out with consecutive patients with diabetic retinopathy and macula-involving TRD of recent (3 months) onset who were randomly assigned to PPV only (PPV group) or PPV combined with one IVB (1.5 mg/0.06 ml) injection 2 weeks prior to surgery (bevacizumab (BEV)/PPV group). All patients underwent 23-gauge PPV 3 weeks after baseline. The main outcome measure was erythrocyte count in the fluid retrieved from the vitrectomy cassette using a Neubauer counting chamber. Results: The study included 20 patients. The mean erythrocyte count was 14865x10(3) (SD 19332x10(3); median 4500x10(3)) cells in the BEV/PPV group, and 176240x10(3) (SD 108375x10(3); median 166600x10(3)) cells in the PPV group. The mean erythrocyte count was significantly lower in the BEV/PPV group than in the PPV group (p < 0.0001). No major adverse events were identified. Conclusion: Preoperative IVB injection was associated with reduced intraocular bleeding during 23-gauge PPV for diabetic macula-involving TRD. Further studies are needed to confirm our preliminary findings.
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Purpose: Bone maintenance after mandibular reconstruction with autogenous iliac crest may be disappointing due to extensive resorption in the long term. The potential of the guided-bone regeneration (GBR) technique to enhance the healing process in segmental defects lacks comprehensive scientific documentation. This study aimed to investigate the influence of polylactide membrane permeability on the fate of iliac bone graft (BG) used to treat mandibular segmental defects. Materials and Methods: Unilateral 10-mm-wide segmental defects were created through the mandibles of 34 mongrel dogs. All defects were mechanically stabilized, and the animals were divided into 6 treatment groups: control, BG alone, microporous membrane (poly L/DL-lactide 80/20%) (Mi); Mi plus BG; microporous laser-perforated (15 cm(2) ratio) membrane (Mip), and Mip plus BG. Calcein fluorochrome was injected intravenously at 3 months, and animal euthanasia was carried out at 6 months postoperatively. Results: Histomorphometry showed that BG protected by Mip was consistently related to larger amounts of bone compared with other groups (P <= .0001). No difference was found between defects treated with Mip alone and BG alone. Mi alone rendered the least bone area and reduced the amount of grafted bone to control levels. Data from bone labeling indicated that the bone formation process was incipient in the BG group at 3 months postoperatively regardless of whether or not it was covered by membrane. In contrast, GBR with Mip tended to enhance bone formation activity at 3 months. Conclusions: The use of Mip alone could be a useful alternative to BG. The combination of Mip membrane and BG efficiently delivered increased bone amounts in segmental defects compared with other treatment modalities. (C) 2008 American Association of Oral and Maxillofacial Surgeons.
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Background/aims: The aim of this study was to compare the morphological and visual acuity outcomes associated with a single intravitreal injection of triamcinolone acetonide versus bevacizumab for the treatment of refractory diffuse diabetic macular oedema. Methods: Twenty-eight patients were randomly assigned to receive a single intravitreal injection of either 4 mg/0.1 ml triamcinolone acetonide or 1.5 mg/0.06 ml bevacizumab. Comprehensive ophthalmic evaluation was performed at baseline and at weeks 1, 4, 8 (+/- 1), 12 (+/- 2) and 24 (+/- 2) after treatment. Main outcome measures included central macular thickness measured with optical coherence tomography (OCT) and best corrected Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity. Results: Twenty-six patients (26 eyes) completed all study visits (two patients missed two consecutive study visits). Central macular thickness was significantly reduced in the intravitreal triamcinolone group compared with the bevacizumab group at weeks 4, 8, 12 and 24 (p<0.05). Logarithm of the minimum angle of resolution (LogMAR) best-corrected visual acuity was significantly higher at weeks 8 (0.69; similar to 20/100(+1)) and 12 (0.74; 20/100(-2)) in the intravitreal triamcinolone group compared with the bevacizumab group (weeks 8 (0.83; similar to 20/125(-1)) and 12 (0.86; 20/ 160(+2))) (p<0.05). Significant change from baseline in mean intraocular pressure (mmHg) was seen at week 4 (+2.25) only in the intravitreal triamcinolone group (p<0.0001). No patient had observed cataract progression during the study. Conclusions: One single intravitreal injection of triamcinolone may offer certain advantages over bevacizumab in the short-term management of refractory diabetic macular oedema, specifically with regard to changes in central macular thickness. The actual clinical relevance of our preliminary findings, however, remains to be determined in future larger studies.
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Mucin 1 (MUC1) is a glycoprotein that is expressed on apical cell membranes in a variety of normal tissues. MUC1 is involved in cell signaling, inhibition of cell-cell and cell matrix adhesion, apoptosis, proliferation, and transcription. Hypoxia is an important factor that promotes cancer metastasis and stimulates angiogenesis and tumor progression. Hypoxia inducible factor 1 (HIF-1 alpha) and carbonic anhydrase IX (CAIX) are two molecules that are involved in this process. The role of hypoxia in MUC1+ invasive ductal breast carcinomas is not well established. In this study, the expression of MUC1 was correlated with the hypoxia-associated markers HIF-1 alpha and CAIX, as well as several immunohistochemical markers and clinicopathologic features of prognostic significance in 243 invasive ductal carcinomas. MUC1 was overexpressed in 37.0% of patients and correlated with the expression of estrogen receptor (p = 0.0001), progesterone receptor (p = 0.0001), HIF-1 alpha (p = 0.006), VEGF (p = 0.024), and p53 (p = 0.025). In breast cancer, MUC1 expression has been associated with increased degradation of inhibitor of NF-kappa B (I kappa B alpha), driving NF-kappa B to the nucleus and blocking apoptosis and promoting cell survival. We analyzed NF-kappa B expression in MUC1+ breast carcinoma and found a very significant relationship between these proteins (p = 0.0001). Our findings indicate that MUC1 may play a role in the regulation of hormone receptors by increasing the inactivation of p53 and targeting NF-kappa B to the nucleus. Our data also support the notion that activation of HIF-1 alpha in MUC1+ breast carcinomas may modulate VEGF expression, allowing a metabolic adaptation to hypoxia.
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To investigate the relationship between NF-kappa B activation and hepatic stellate cell (HSC) apoptosis in hepatosplenic schistosomiasis, hepatic biopsies from patients with Schistosoma mansoni-induced periportal fibrosis, hepatitis C virus-induced cirrhosis, and normal liver were submitted to alpha-smooth muscle actin (alpha-SMA) and NF-kappa B p65 immunohistochemistry, as well as to NF-kappa B Southwestern histochemistry and TUNEL assay. The numbers of alpha-SMA-positive cells and NF-kappa B- and NF-kappa B p65-positive HSC nuclei were reduced in schistosomal fibrosis relative to liver cirrhosis. In addition, increased HSC NF-kappa B p65 and TUNEL labeling was observed in schistosomiasis when compared to cirrhosis. These results suggest a possible relationship between the slight activation of the NF-kappa B complex and the increase of apoptotic HSC number in schistosome-induced fibrosis, taking place to a reduced HSC number in schistosomiasis in relation to liver cirrhosis. Therefore, the NF-kappa B pathway may constitute an important down-regulatory mechanism in the pathogenesis of human schistosomiasis mansoni, although further studies are needed to refine the understanding of this process. (C) 2009 Elsevier B.V. All rights reserved.
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OBJECTIVE: HIV transmission has been associated with offering a child food prechewed by an HIV-infected caregiver. We assessed awareness of prechewing and oral prewarming of food by an adult before offering it to a child among HIV-infected pregnant women and clinical investigators in 3 Latin American countries. METHODS: HIV-infected pregnant women at 12 sites (Eunice Kennedy Shriver National Institute of Child Health and Human Development International Site Development Initiative Perinatal Longitudinal Study in Latin American Countries, a prospective cohort trial) in Argentina, Brazil, and Peru were administered a screening survey about prechewing/prewarming of infant foods and cautioned against these feeding practices. Survey responses were analyzed, overall, and stratified according to country. RESULTS: Of the 401 HIV-infected pregnant women interviewed, 34% had heard about prechewing (50% from Argentina, 32% from Brazil, and 36% from Peru), 23% knew someone who prechewed food for infants, and 4% had prechewed food in the past. Seventeen percent had heard about oral prewarming of food, 13% knew someone who prewarmed food for infants, and 3% had prewarmed food for an infant in the past. Women who reported knowing someone who prechewed were more likely to also know someone who prewarmed food (P < .0001). Few site investigators anticipated that their patients would be aware of these practices. CONCLUSIONS: Prechewing food, a potential risk factor for HIV transmission, and orally prewarming food, which has not been associated with HIV transmission but might expose a child to blood from an HIV-infected adult, are not uncommon practices in Latin America. Both practices should be further investigated. Site investigator responses underscore that health care providers could be missing information about cultural practices that patients may not report unless specifically asked. Pediatrics 2011;127:e1206-e1211
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Background/Objectives: Vitamin A deficiency (VAD) is a major public health problem. The supplementation of lactating women could be an effective strategy to combat it. The objective of this study was to assess the impact of maternal vitamin A supplementation on the mother-infant pair. Subjects/Methods: This was a double blind, placebo-controlled randomized clinical assay in which 33 women received 200 000 IU of vitamin A and 33 women received soy oil between 20th and 30th postpartum days. Maternal blood and milk samples were collected immediately before supplementation and 3 months after delivery, when blood was also collected from the babies. Retinol concentrations <= 0.70 mu mol/l in serum and 1.05 mu mol/l in milk were considered to indicate VAD. Results: Increase in serum retinol level was observed in the supplemented group compared with the pre-supplementation levels (1.05 and 1.17 mu mol/l, respectively; P = 0.026) and to the post-supplementation levels of the control group (1.02 mu mol/l; P = 0.032). Reduction in breast milk retinol was observed in the control group compared with the pre-supplementation levels (1.93 and 1.34 mu mol/l, respectively; P<0.0001) and to the post-supplementation levels of the supplemented group (1.56 mu mol/l; P = 0.0003). There was significant difference in the prevalence of VAD in breast milk after supplementation, 55.6% (15/27) in the control group and 16.1% (5/31) in the supplemented group (P = 0.002). VAD was present in 66.1% (39/59) of infants, with mean serum retinol levels of 0.64 +/- 0.30 mu mol/l in the control group and of 0.69 +/- 0.26 mu mol/l in the supplemented group. Conclusions: Supplementation had a positive impact on maternal vitamin A status. No effect on infant status was detectable 2 months after supplementation with a single dose. European Journal of Clinical Nutrition (2010) 64, 1302-1307; doi: 10.1038/ejcn.2010.165; published online 15 September 2010
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Background: The major stress response to critical illness leads to a catabolic state and loss of lean body mass. Aims: To test whether an increased rate of creatinine excretion might provide unique and timely information to monitor cell catabolism; to relate this information to balances of cell constituents (nitrogen, potassium, phosphate and magnesium); to evaluate the effectiveness of nutritional therapy to reverse this catabolic process. Design: Prospective observational study. Methods: Children with severe traumatic brain injury admitted to the paediatric critical care units of The Hospital for Sick Children, Toronto, Canada and Hospital das Clnicas, Faculty of Medicine of Ribeiro Preto, University of So Paulo, Brazil were studied. Complete 24 h urine collections were obtained for measurement of creatinine excretion rate and daily balances of nitrogen, potassium, phosphate and magnesium. Results: Seventeen patients were studied for 310 days. On Day 1, all had negative balances for protein and phosphate. Balances for these intracellular constituents became positive when protein intake was >= 1 g/kg/day and energy intake was >= 50% of estimated energy expenditure (P < 0.0001). Creatinine excretion rate was positively correlated with the urea appearance rate (r = 0.60; P < 0.0001), and negatively with protein balance (r = -0.45; P < 0.0001). Sepsis developed in four patients; before its clinical detection, there were negative balances for all intracellular markers and an abrupt rise in the excretion of creatinine. Conclusions: Negative balances of intracellular components and an increase in rate of creatinine excretion heralded the onset of catabolism.
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Our objective was to describe the prevalence of low concentrations of retinol, beta-carotene, and vitamin E in a group of human immunodeficiency virus (HIV)-infected Latin American children and a comparison group of HIV-exposed, uninfected children. Our hypothesis was that the rates of low concentrations of these micronutrients would be higher in the HIV-infected group than those in the HIV-exposed, uninfected group. This was a cross-sectional substudy of a larger cohort study at clinical pediatric HIV centers in Latin America. Serum levels of micronutrients were measured in the first stored sample obtained after each child`s first birthday by high-performance liquid chromatography. Low concentrations of retinol, beta-carotene, and vitamin E were defined as serum levels below 0.70, 0.35, and 18.0 mu mol/L, respectively. The Population for this analysis was 336 children (124 HIV-infected, 212 HIV-exposed, uninfected) aged I year or older to younger than 4 years. Rates of low concentrations were 74% for retinol, 27% for beta-carotene, and 89% for vitamin E. These rates were not affected by HIV status. Among the HIV-infected children, those treated with anti retrovirals were less likely to have retinol deficiency, but no other HIV-related factors correlated with micronutrient low serum levels. Low concentrations of retinol, beta-carotene, and vitamin E are very common in children exposed to HIV living in Brazil, Argentina, and Mexico, regardless of HIV-infection status. Published by Elsevier Inc.
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Rasmussen encephalitis (RE) is characterized by intractable epilepsy, progressive hemiparesis, and unilateral hemispheric atrophy. The progression of the symptoms to significant neurological impairment usually occurs within months to a few years. RE causes are unknown, although evidence of an autoimmune process has been extensively described in the literature. Antiepileptic drugs are usually not effective to control seizures or cerebral atrophy; despite data supporting a beneficial effect of early immunosuppressive and immunomodulatory interventions, for intractable seizures in RE patients with advanced disease, epilepsy surgery in the form of hemispheric disconnection has been considered the treatment of choice. This work describes the clinical and electrographic analyses, as well as the post-operative evolution of patients with RE. This work includes all the patients with RE evaluated from January 1995 to January 2008 by the RibeirA o pound Preto Epilepsy Surgery Program (CIREP), taking variables such as gender; age at epilepsy onset; seizure semiology; seizure frequency; interictal and ictal electroencephalographic (EEG) findings; age at surgery, when done; duration of epilepsy; surgery complications; follow-up duration; anatomo-pathological findings; post-surgery seizure; language and cognitive outcome; and anti-epileptic drug treatment after surgery into account. Twenty-five patients were evaluated; thirteen were female. Mean age of epilepsy onset was 4.4 +/- 2.0 years. There were no differences between patients with slow and fast evolution with respect to age of epilepsy onset (p = 0.79), age at surgery (p = 0.24), duration of epilepsy (0.06), and follow-up (p = 0.40). There were no correlations between the presence of bilateral EEG abnormalities or the absence of spikes and post-operative seizure outcome (p = 0.06). Immunomodulatory therapy was tried in 12 patients (48%). Twenty-three patients underwent surgery. The mean follow-up was 63.3 months. Eleven patients had total seizure control. Twelve individuals persisted with seizures consisting of mild facial jerks (six patients), occasional hemigeneralized tonic-clonic seizures (three patients), and frequent tonic-clonic seizures (three patients). Mental and language impairment was observed in 15 and 12 patients, after surgery, respectively. Eight patients presented post-operative cognitive decline, while only two patients had cognitive improvement. Comparing pre- and post-operative language deficits, 66.7% of the 12 patients with language disturbance did not improve after surgery. This retrospective study reported the clinical and electrographic analysis, as well as the evolution of 23 patients with RE. Patients were divided into two groups: fast evolution and slow evolution to hemiparesis and epilepsia partialis continua. These groups may represent different RE substrates. Fourteen patients achieved satisfactory seizure control, three patients had partial response to surgery, and five patients had maintenance of the pre-operative condition. All patients with left-side involvement presented with some language disturbance, which did not improve after surgery in 66.6% of patients. Cognitive evaluation showed that the majority of the patients did not have any significant improvement, and 38.1% had cognitive deterioration after surgery.
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Several papers on Schistosoma mansoni and Schistosoma japonicum proteomes have been published worldwide in the past few years, representing an emerging field of study. Knowledge of the schistosome proteome may greatly enhance our understanding of schistosome physiological processes at the molecular level, and may provide new models for development of vaccines or drugs. Despite the importance of this approach. schistosome proteomic research in Brazil is still incipient. Here we review the development of schistosome proteomic research around the world and provide an appreciation on the future opportunities in Brazil. (c) 2008 Elsevier B.V. All rights reserved
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Bothropstoxin-I (BthTx-I) is a homodimerie Lys49-PLA(2) from the venom of the snake Bothrops jararacussu, which lacks hydrolytic activity against phospholipid substrates, yet permeabilizes membranes by a Ca2+- independent mechanism. The interaction of the BthTx-I with model membranes has been studied by intrinsic tryptophan fluorescence emission (ITFE) spectroscopy. Nine separate mutants have been created each with a unique tryptophan residue located at a different position in the interfacial recognition site (IRS) of the protein. The rapid and efficient Ca2+-independent membrane damage against unilamellar liposomes composed of DPPC/DMPA in a 9:1 molar ratio was unaffected by these substitutions. Binding studies revealed low protein affinity for these liposomes and no changes were observed in the ITFE properties. In contrast, the binding of all mutants to DPPC/DMPA liposomes in a 1:1 molar ratio was stronger, and was correlated with altered ITFE properties. The blue-shifted emission spectra and increased emission intensity of mutants at positions 31, 67 and 115-117 in the interface recognition surface of the protein suggest these regions are partially inserted into the membrane. These results are consistent with a model for the Ca2+-independent membrane damaging mechanism that involves a transient interaction of the protein with the outer phospholipid leaflet of the target membrane. (C) 2007 Elsevier Masson SAS. All rights reserved.
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Human leukocyte antigen-G (HLA-G) is a non-classical major histocompatibility complex (MHC) class Ib molecule predominantly expressed in cytotrophoblasts, where it acts as a specific immunosuppressor. Literature data have shown that grafts in some settings, such as cardiac and liver/kidney-associated transplantations, express HLA-G and this expression is associated with less severe rejection and also reduces the incidence of rejection. Fourteen-base pair deletion/insertion polymorphism has been reported in exon 8 of the 3`-untranslated region of HLA-G. This polymorphism within exon 8 of the HLA-G gene might influence transcription activity, which in turn may influence the stability of HLA-G transcripts. This influences the stability of the HLA-G protein and therefore is of potential functional relevance. In order to determine a possible correlation between the 14-bp insertion/deletion polymorphism and kidney allograft outcome, we isolated genomic DNA from 83 patients who had received isolated kidney allografts, and we classified the 83 specimens into two groups, grafts presenting Banff features of rejection group and a non-rejection group, and compared them with a control group of 97 healthy subjects. The 14-bp polymorphism at exon 8 was genotyped in all groups. There was no significant difference in allelic frequencies of 14-bp insertion/deletion polymorphism between normal controls and kidney transplant patients. In the RG, the homozygous genotype +14/+14 bp (P = 0.0238) was significantly increased in the group with acute rejection compared with the healthy control group. Analysis of other HLA-G polymorphisms and functional studies on immune regulation are essential to elucidate the role of HLA-G in kidney allografts.