971 resultados para Tissue elastic


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The reduction of parasitism tissue upon treatment with two lignano lactones, namely (-)- cubebin (CUB) and (-)-hinokinin (HNK), was evaluated in the chronic phase of Chagas` disease by quantifying the enzyme beta-galactosidase expressed by the CL B5 clone strain of Trypanosoma cruzi. Tissue karyometry was also performed. Treatment with the assessed lignans led to a larger reduction in parasitism tissue in all evaluated organs, compared with benznidazole (BZN). Oral treatment with CUB or HNK was more effective. Karyometry results demonstrated that the infected control animals had increased nuclear area compared with uninfected controls, indicating cellular hypertrophy. Results also revealed that use of CUB or HNK was able to significantly prevent this increase, and a slight decrease in the nuclear area was observed, compared with mice treated with BZN. Taken together, these data demonstrate that CUB and HNK could be considered as potential compounds for the development of new drugs for treatment of Chagas` disease.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Topical delivery of lycopene is a convenient way to supplement cutaneous levels of antioxidants. In this study, lycopene was incorporated (0.05%, w/w) in two microemulsions containing BRIJ-propylene glycol (2:1, w/w, surfactant blend) but different oil phases: mono/diglycerides of capric and caprylic acids (MG) or triglycerides of the same fatty acids (TG). Microemulsions containing MG and TG were isotropic, fluid, and clear, with internal phase diameters of 27 and 52 nm, respectively. Both MG- or TG-containing microemulsions markedly increased lycopene penetration in the stratum corneum, (6- and 3.6-fold, respectively) and in viable layers of porcine ear skin 2 (from undetected to 172.6 +/- 41.1 and 103.1 +/- 7.2 ng/cm(2), respectively) compared to a control solution. To assure that lycopene delivered to the skin was active, the antioxidant activity of skin treated with MG-containing microemulsion was determined by CUPRAC assay, and found to be 10-fold higher than untreated skin. The cytotoxicity of MG-containing microemulsion in cultured fibroblasts was similar to propylene glycol (considered safe) and significantly less than of sodium lauryl sulfate (a moderate-to-severe irritant) at 1-50 mu g/mL. These results demonstrate that the MG-containing microemulsion is an efficient and safe system to increase lycopene delivery to the skin and the antioxidant activity in the tissue. (C) 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:1346-1357, 2010

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We developed a new method for the quantification of parasites in tissue. Trypanosoma cruzi strain CL parasites were genetically engineered to express the Escherichia coli beta-galactosidase gene, lacZ and this enzyme is able to catalyze a colorimetric reaction with chlorophenol red beta-d galactopyranoside (CPRG) as the substrate. The animals were infected with clone CL Brener strain B5 of T. cruzi and treated with benznidazole in order to verify the reduction in the number of parasites in tissue study by quantifying the enzyme beta-galactosidase. The assay demonstrates a reduction in the number of parasites in the groups treated. Thus, this test can be used to test other substances with the aim of verifying the effectiveness in the chronic phase of experimental Chagas` disease.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We sequenced cDNAs coding for chicken cellular nucleic acid binding protein (CNBP). Two slightly different variations of the open reading frame were found, each of which translates into a protein with seven zinc finger domains. The longest transcript contains an in-frame insert of 3 bp. The sequence conservation between chick CNBP cDNAs with human, rat and mouse CNBP cDNAs is extreme, especially in the coding region, where the deduced amino acid sequence identity with human, rat and mouse CNBP is 99%. CNBP-like transcripts were also found in various tissues from insect, shrimp, fish and lizard. Regions with remarkable nucleotide conservation were also found in the 3' untranslated region, indicating important functions for these regions. Quantitative reverse transcription polymerase chain reaction (RT-PCR) indicated that in the chick, CNBP is present in all tissues examined in approximately equal ratios to total RNA. RT-PCR of total RNA isolated from different phyla indicate CNBP-like proteins art widespread throughout the animal kingdom. The extraordinary level of conservation suggests an important physiological role for CNBP. (C) 1997 Elsevier Science Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Multifrequency bioimpedance analysis has the potential to provide a non-invasive technique for determining body composition in live cattle. A bioimpedance meter developed for use in clinical medicine was adapted and evaluated in 2 experiments using a total of 31 cattle. Prediction equations were obtained for total body water, extracellular body water, intracellular body water, carcass water and carcass protein. There were strong correlations between the results obtained through chemical markers and bioimpedance analysis when determined in cattle that had a wide range of liveweights and conditions. The r(2) values obtained were 0.87 and 0.91 for total body water and extracellular body water respectively. Bioimpedance also correlated with carcass water, measured by chemical analysis (r(2) = 0.72), but less well with carcass protein (r(2) = 0.46). These correlations were improved by inclusion of liveweight and sex as variables in multiple regression analysis. However, the resultant equations were poor predictors of protein and water content in the carcasses of a group of small underfed beef cattle, that had a narrow range of liveweights. In this case, although there was no statistical difference between the predicted and measured values overall, bioimpedance analysis did not detect the differences in carcass protein between the 2 groups that were apparent following chemical analysis. Further work is required to determine the sensitivity of the technique in small underfed cattle, and its potential use in heavier well fed cattle close to slaughter weight.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tissue responses to the application of Rototags and Jumbo Rototags in the first dorsal fin of Carcharhinus melanopterus, C. obscurus and C. plumbeus were examined. The acute response included tissue tearing and haemorrhage and was present by 5 days post-tagging. The intermediate response had begun by 20 days post-tagging and continued beyond 207 days. This response involved decreased red blood cell activity as the inflammatory response commenced. The chronic response had begun by 301 days and was complete by 553 days with a layer of fibrous connective tissue walling off the tag. External damage to the fin was caused by continued abrasion by the tag. Repair scales were observed at 242 days using scanning electron microscopy and were confirmed histologically in 61- and 553-day samples. Repair scales were not seen in areas of continuous abrasion. No infection was observed in tissues surrounding the wound. Disruption of the fin surface was observed due to abrasion by the tag, but did not appear to cause a severe tissue reaction. The tissue responses observed were consistent with a normal, but relatively slow, healing in the vicinity of the tag wound. Use of Rototags or Jumbo Rototags appears to be an efficient way of marking elasmobranchs with minimal damage to the shark. (C) 1998 The Fisheries Society of the British Isles.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

1 Voltage-operated calcium channel (VOCC) antagonists are effective antihypertensive and antianginal agents but they also depress myocardial contractility. 2 We compared four L-type calcium channel antagonists, felodipine, nifedipine, amlodipine and verapamil and a relatively T-type selective calcium channel antagonist, mibefradil, on human and rat isolated tissue assays to determine their functional vascular to cardiac tissue selectivity (V/C) ratio. 3 The V/C ratio was calculated as the ratio of the IC50 value of the antagonist that reduced (by 50%) submaximally contracted (K+ 62 mM) human small arteries from the aortic vasa vasorum (vascular, V) mounted in a myograph and the IC50 value of the antagonist that reduced (-)-isoprenaline (6 nM) submaximally stimulated human right atrial trabeculae muscle (cardiac, C) mounted in organ chambers. 4 The average pIC(50) Values (-log IC50 M) for the human vascular preparations were felodipine 8.30, nifedipine 7.78, amlodipine 6.64, verapamil 6.26 and mibefradil 6.22. The average pIC(50) values for the cardiac muscle were felodipine 7.21, nifedipine 6.95, verapamil 6.91, amlodipine 5.94, and mibefradil 4.61. 5 The V/C ratio calculated as antilog [pIC(50)V-pIC(50)C] is thus mibefradil 41, felodipine 12, nifedipine 7, amlodipine 5 and verapamil 0.2. 6 In rat small mesenteric arteries the pIC(50) values for the five drugs were similar to the values for human vasa vasorum arteries contracted by K+ 62 mM. However for methoxamine (10 mu M) contraction in the rat arteries the pIC(50) values were lower for felodipine 7.24 and nifedipine 6.23, but similar for verapamil 6.13, amlodipine 6.28 and mibefradil 5.91. 7 In conclusion in the human tissue assays, the putative T-channel antagonist mibefradil shows the highest vascular to cardiac selectivity ratio; some 3 fold higher than the dihydropyridine, felodipine, and some 200 fold more vascular selective than the phenylalkylamine, verapamil. This favourable vascular to cardiac selectivity for mibefradil, from a new chemical class of VOCC antagonist, may be explained by its putative T-channel selectivity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tissue susceptibility and resistance to infection with the yeast Candida albicans is genetically regulated. Analysis of the strain distribution pattern of the C. albicans resistance gene (Carg1) and additional gene and DNA segment markers in the AKXL recombinant inbred (RI) set showed that 13/15 RI strains were concordant for Carg1, Tcra and Rib1. Therefore, Carg1 is probably located within a 17 cM segment of chromosome 14, within approximately 4 cM of the other two genes. (C) 1998 Academic Press.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The severity of systemic infection with the yeast Candida albicans has been shown to be under complex genetic control. C57/L mice carry an allele that is associated with an increase in tissue destruction when compared with C57BI/6 mice; however, the gene affects only the severity of tissue lesions, and does not influence the magnitude of the fungal burden in either kidney or brain. Studies in [C57/L x C57BI/6]F1 hybrid mice, and [C57/L x C57BI/6]F1 x C57/L backcross mice, demonstrated that the gene behaves as a simple Mendelian co-dominant. (C) 1998 Academic Press.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The role of T lymphocytes in host responses to sublethal systemic infection with Candida albicans was evaluated by mAb depletion of CD4(+) and CD8(+) cells from BALB/c and CBA/CaH mice, which develop mild and severe tissue damage, respectively. Depletion of CD4(+) lymphocytes from BALB/c mice markedly increased tissue damage, but did not alter the course of infection. In CBA/CaH mice, depletion of CD4+ cells abrogated tissue destruction in both brain and kidney at day 4 after infection, and significantly decreased fungal colonization in the brain. However, the severity of tissue lesions increased relative to controls from day 8 onwards. A small increase in tissue damage was evident in both mouse strains after depletion of CD8(+) cells. There were no major differences between days 4 end 8 after infection in cDNA cytokine profiles of CD4(+) lymphocytes from either BALB/c or CBA/CaH mice. After passive transfer into infected syngeneic recipients, spleen cells from infected CBA/CaH mice markedly increased tissue damage when compared to controls, and also caused a significant increase in fungal colonization in the brain. A similar transfer in BALB/c mice increased the number of inflammatory cells in and around the lesions, but had no effect on the fungal burden in brain and kidney. The data demonstrate that both CD4(+) and CD8(+) lymphocytes contribute to the reduction of tissue damage after systemic infection with C. albicans, and that the development and expression of CD4(+) lymphocyte effector function is influenced by the genetic background of the mouse.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: To use magnetic resonance imaging (MRI) to validate estimates of muscle and adipose tissue (AT) in lower limb sections obtained by dual-energy X-ray absorptiometry (DXA) modelling. DESIGN: MRI measurements were used as reference for validating limb muscle and AT estimates obtained by DXA models that assume fat-free soft tissue (FFST) comprised mainly muscle: model A accounted for bone hydration only; model B also applied constants for FFST in bone and skin and fat in muscle and AT; model C was as model B but allowing for variable fat in muscle and AT. SUBJECTS: Healthy men (n = 8) and women (n = 8), ages 41 - 62 y; mean (s.d.) body mass indices (BMIs) of 28.6 (5.4) kg/m(2) and 25.1 (5.4) kg/m2, respectively. MEASUREMENTS: MRI scans of the legs and whole body DXA scans were analysed for muscle and AT content of thigh (20 cm) and lower leg (10 cm) sections; 24 h creatinine excretion was measured. RESULTS: Model A overestimated thigh muscle volume (MRI mean, 2.3 l) substantially (bias 0.36 l), whereas model B underestimated it by only 2% (bias 0.045 l). Lower leg muscle (MRI mean, 0.6 l) was better predicted using model A (bias 0.04 l, 7% overestimate) than model B (bias 0.1 l, 17% underestimate). The 95% limits of agreement were high for these models (thigh,+/- 20%; lower leg,+/- 47%). Model C predictions were more discrepant than those of model B. There was generally less agreement between MRI and all DXA models for AT. Measurement variability was generally less for DXA measurements of FFST (coefficient of variation 0.7 - 1.8%) and fat (0.8 - 3.3%) than model B estimates of muscle (0.5-2.6%) and AT (3.3 - 6.8%), respectively. Despite strong relationships between them, muscle mass was overestimated by creatinine excretion with highly variable predictability. CONCLUSION: This study has shown the value of DXA models for assessment of muscle and AT in leg sections, but suggests the need to re-evaluate some of the assumptions upon which they are based.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A method by which to overcome the clinical symptoms of atherosclerosis is the insertion of a graft to bypass an artery blocked or impeded by plaque. However, there may be insufficient autologous mammary artery for multiple or repeat bypass, saphenous vein may have varicose degenerative alterations that can lead to aneurysm in high-pressure sites, and small-caliber synthetic grafts are prone to thrombus induction and occlusion. Therefore, the aim of the present study was to develop an artificial blood conduit of any required length and diameter from the cells of the host for autologous transplantation. Silastic tubing, of variable length and diameter, was inserted into the peritoneal cavity of rats or rabbits. By 2 weeks, it had become covered by several layers of myofibroblasts, collagen matrix, and a single layer of mesothelium. The Silastic tubing was removed from the harvested implants, and the tube of living tissue was everted such that it now resembled a blood vessel with an inner lining of nonthrombotic mesothelial cells (the intima), with a media of smooth muscle-like cells (myofibroblasts), collagen, and elastin, and with an outer collagenous adventitia. The tube of tissue (10 to 20 mm long) was successfully grafted by end-to-end anastomoses into the severed carotid artery or abdominal aorta of the same animal in which they were grown. The transplant remained patent for at least 4 months and developed structures resembling elastic lamellae. The myofibroblasts gained a higher volume fraction of myofilaments and became responsive to contractile agonists, similar to the vessel into which they had been grafted. It is suggested that these nonthrombogenic tubes of living tissue, grown in the peritoneal cavity of the host, may be developed as autologous coronary artery bypass grafts or as arteriovenous access fistulae for hemodialysis patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Isolated limb perfusion (ILP) with melphalan is used to treat recurrent melanoma. This study aimed to develop a microdialysis technique for melphalan tissue concentration measurement during ILP. The effects of melphalan concentration (50-600 mu g/ml), microdialysis flow rate (0.55-17.5 mu l/min), probe length (5-50 mm) and temperature (25-41.5 degrees C) on in vitro recovery were studied. In addition, in vivo recovery was measured in rat hindlimbs perfused with melphalan using 50 mm microdialysis probes implanted subcutaneously and into muscle. Both dialysate and tissue sample melphalan concentrations were determined by high performance liquid chromatography. The in vitro recovery of melphalan was not affected by melphalan concentration or temperature, but increased with probe length and decreased with flow rate. The melphalan concentrations in subcutaneous and muscle dialysates were not significantly different. A linear relationship was found between tissue dialysate concentrations and actual tissue concentrations of melphalan (r(2) = 0.97). Microdialysis is a potential method for tissue drug monitoring which may assist in the efficacious use of cytotoxics in human ILP. (C) 2000 Lippincott Williams & Wilkins.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective. Differentiated dendritic cells (DC) and other antigen-presenting cells are characterized by the nuclear location of RelB, a member of the nuclear factor kappa B/Rel family. To characterize and enumerate differentiated DC in rheumatoid arthritis (RA) peripheral blood (PB), synovial fluid (SF), and synovial tissue (ST), the expression and location of RelB were examined. Methods. RelB protein expression and cellular location were determined in RA PB, SF, and ST by flow cytometry and immunohistochemical analysis of purified cells or formalin-fixed tissue. DNA-binding activity of RelB was determined by electrophoretic: mobility shift-Western immunoblotting assays. Results. Circulating RA PBDC resembled normal immature PBDC in that they did not express intracellular RelB protein. In RA ST serial sections, cells containing nuclear RelB (nRelB) were enriched in perivascular regions. A mean +/- SD of 84 +/- 10% of these cells were DC. The remaining nRelB+,HLA-DR+ cells comprised B cells and macrophages. Only 3% of sorted SFDC contained nRelB, However, RelB present in the nucleus of these SFDC was capable of binding DNA, and therefore capable of transcriptional activity. Conclusion. Circulating DC precursors differentiate and express RelB after entry into rheumatoid ST. Differentiated DC can thus be identified by immunohistochemistry in formalin-fixed ST. Signals for DC maturation may differ between RA ST and SF, resulting in nuclear location of RelB predominantly in ST. This is likely to have functional consequences for the DC in these sites.