987 resultados para Active vibration controls


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To determine whether opportunistic oral infections associated to HIV infection (OOI-HIV) are found in HIV+/AIDS patients with immune reconstitution related to highly active antiretroviral therapy (HAART). Methods. From among 1100 HIV+/AIDS patients (Service of Internal Medicine, Carlos Haya Hospital, Malaga, Spain) subjected to review of the oral cavity between January 1996 and May 2007, we identified those examined in 1996 and which were again examined between 1997 and 2007, and were moreover receiving HAART. The following data were collected: age, gender, form of contagion, antiretroviral therapy at the time of review, number of CD4+ lymphocytes/ml, and viral load (from 1997 onwards). We identified those subjects with an increase in CD4+ lymphocytes/ ml associated to HAART, and classified them as subjects with quantitative evidence of immune reconstitution (QEIR). Among these individuals with QEIR we moreover identified those with undetectable viral loads (QEIR+VL), and differentiated those patients with an increase in CD4+ lymphocytes > 500/ml (QEIRm+VL). In each group we determined the prevalence of OOI-HIV, following the diagnostic recommendations of the EC-Clearinghouse (CDC-Atlanta, USA - WHO). In addition, we analyzed the prevalence of OOI-HIV in the different groups in relation to the duration of HAART. Results. A total of 86 subjects were included (44 females and 42 males; 19 heterosexuals, 34 male homosexuals, and 33 intravenous drug abusers). Forty-two patients showed QEIR: 21 belonged to the QEIR+VL group, and 17 conformed the QEIRm+VL group. The prevalence of OOI-HIV per group was as follows: QEIR = 54.8%; QEIR+VL = 33%; QEIRm+VL = 35%. The most prevalent lesion in all groups was erythematous candidiasis. OOI-HIV increased with the duration of HAART (p=0.008), and were seen to be dependent upon late appearance of the mycotic lesions ( after 24 months under HAART). Conclusions: It is suggested that opportunistic oral infections associated to HIV infection form part of the clinical picture of immune reconstitution inflammatory syndrome, though such infections are of late onset.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The selection of housekeeping genes is critical for gene expression studies. To address this issue, four candidate housekeeping genes, including several commonly used ones, were investigated in oral squamous cell carcinoma cell lines. A simple quantitative RT-PCR approach was employed by comparing relative expression of the four candidate genes within two cancerous cell tines (HN6 and HN31) and one noncancerous cell tine (HaCaT) treated or not with EGF and TGF-beta 1. Data were analyzed using ANOVA followed by the NormFinder software program. On this basis, stability of the candidate housekeeping genes was ranked and non statistical differences were found using ANOVA test. On the other hand, the NormFinder was able to show that GAPD and TUBB presented the less variable results, representing appropriated housekeeping genes for the samples and conditions anatyzed. In conclusion, this study suggests that the GAPD and the TUBB represent adequate normalizers for gene profiting studies in OSCC cell. tines, covering, respectively, high and low expression levels genes. (C) 2008 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Enzymes are crucial for the metabolism of macromolecular substrates. In the great majority of cells, most enzymes are constitutive. Nevertheless, inducible enzymes can predominate, determining specialized cell functions. Within this context, histochemistry/immunohistochemistry and biochemistry were used to investigate expression of peroxidase and reduced nicotinamide-adenine dinucleotide phosphate (NADPH)-oxidase, as well as the expression and activity of cathepsin D and acid phosphatase, in trophoblast cells within the endotheliochorial labyrinth and marginal hematoma of the term cat placenta. In the marginal hematoma, elevated Cathepsin D expression and activity was accompanied by erythrophagocytosis. In contrast, acid phosphatase activity was much more intense in the labyrinth, where metabolic exchanges occur. Peroxidase and NAD(P)H-oxidase were predominantly active in trophoblast cells within endosomal vesicles of different placental compartments, indicating that, although reactive oxygen species might participate in endosomal/lysosomal processes, they are not territorially specific or functional markers. These findings highlight differential characteristics of cathepsin D and acid phosphatase activity within each placental compartment, thereby contributing to the comprehension of the territorial role played by the placenta and facilitating future metabolic studies. (C) 2007 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Plasmablastic lymphoma (PBL) is an HIV-associated non-Hodgkin`s lymphoma that primarily affects the oral cavity. We describe the case of an HIV patient with a lesion in the maxilla that lasted four months. He was diagnosed with PBL and received highly active antiretroviral therapy as well as chemotherapy and local radiotherapy. The lesion regressed after the third cycle of chemotherapy. The patient interrupted antiretroviral treatment and the lesion recurred. The immune reconstitution secondary to the use of antiretroviral therapy seems to participate in the regression of PBL and maintains the remission of the tumour, but it might not be enough to prevent the development of PBL.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We examined whether two functional polymorphisms (g.-1562C>T and g.-90(CA)14-24) in the matrix metalloproteinase (MMP)-9 gene or MMP-9 haplotypes affect the circulating levels of pro-MMP-9 and pro-MMP-9/TIMP-1 (tissue inhibitor of metalloproteinase-1) ratios in AIDS patients, and modulate alterations in these biomarkers after highly active antiretroviral therapy (HAART). We studied 82 patients commencing HAART. Higher pro-MMP-9 concentrations and pro-MMP-9/TIMP-1 ratios were found in CT/TT patients compared with CC patients. HAART decreased pro-MMP-9 levels and pro-MMP-9/TIMP-1 ratios in CT/TT patients, it did not modify pro-MMP-9 levels and it increased pro-MMP-9/TIMP-1 ratios in CC patients. The g.-90(CA)14-24 polymorphism, however, produced no significant effects. Moreover, we found no significant differences in HAART-induced changes in plasma pro-MMP-9, TIMP-1 and pro-MMP-9/TIMP-1 ratios when different MMP-9 haplotypes were compared. These findings suggest that the g.-1562C>T polymorphism affects pro-MMP-9 levels in patients with AIDS and modulates the alterations in pro-MMP-9 levels caused by HAART, thus possibly affecting the risk of cardiovascular complications. The Pharmacogenomics Journal (2009) 9, 265-273; doi: 10.1038/tpj.2009.13; published online 21 April 2009

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Spinal signs found in association with atypical chest and abdominal pain may suggest the pain is referred from the thoracic spine. However, the prevalence of such signs in these conditions has rarely been compared with that in those without pain. In this study, the prevalence of spinal signs and dysfunction in patients with back, chest and abdominal pain is compared with that in pain free controls. The aim of the study is to determine the significance of spinal findings in patients with such pain. Methods: A general practitioner blinded to the patients' histories performed a cervical and thoracic spinal examination on general practice patients with back, chest and/or abdominal pain and on controls without pain. Thoracic intervertebral dysfunction was diagnosed on the basis of movement and palpation findings. Results: Seventy three study patients plus 24 controls, were examined. For cervical spinal signs, pain in the back, chest and/or abdomen was associated with pain with active movements and overpressure at end range and with loss of movement range. For thoracic spinal signs, this association held for pain with active movements and overpressure, but not with loss of movement range. The prevalence of thoracic intervertebral dysfunction was 25.0% in controls, 65.5% with chest/abdominal pain, 72.0% with back pain and 79.0% with back pain with chest/abdominal pain. This prevalence was higher with chest pain than with abdominal pain. Conclusions: The results show an association, but not a causal link between thoracic intervertebral dysfunction and atypical chest/abdominal pain. A spinal examination should be performed routinely assessing these conditions. The minimum examination for the detection of intervertebral dysfunction is testing for pain with spinal movements and palpation for tenderness. The interpretation of positive signs requires knowledge of their prevalence in pain free controls and in patients with visceral disease

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study determined the frequencies of a G-to-A transition (S/N167) polymorphism in exon 4 of the parkin gene in Australian Parkinson's disease patients and control subjects. The genotype of each subject was determined using the polymerase chain reaction and restriction-fragment-length-polymorphism analysis. Overall, the A allele was significantly less common in the Parkinson's disease group (1.7%) compared with the control group (3.8%, OR = 0.43, 95% CI = 0.19-1.00, P < 0.05), although the frequency in the young onset Parkinson's disease group (6.6%) was not significantly different to controls. The A allele is less common in Australian Caucasian subjects compared to Japanese Parkinson's disease patients and appears to be under-represented in older-onset Parkinson's disease. <(c)> 2001 Elsevier Science Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The electromechanical transfer characteristics of adhesively bonded piezoelectric sensors are investigated. By the use of dynamic piezoelectricity theory, Mindlin plate theory for flexural wave propagation, and a multiple integral transform method, the frequency-response functions of piezoelectric sensors with and without backing materials are developed and the pressure-voltage transduction functions of the sensors calculated. The corresponding simulation results show that the sensitivity of the sensors is not only dependent on the sensors' inherent features, such as piezoelectric properties and geometry, but also on local characteristics of the tested structures and the admittance and impedance of the attached electrical circuit. It is also demonstrated that the simplified rigid mass sensor model can be used to analyze successfully the sensitivity of the sensor at low frequencies, but that the dynamic piezoelectric continuum model has to be used for higher frequencies, especially around the resonance frequency of the coupled sensor-structure vibration system.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ligands of the 2-pyridylcarbaldehyde isonicotinoylhydrazone class show high iron (Fe) sequestering efficacy and have potential as agents for the treatment of Fe overload disease. We have investigated the mechanisms responsible for their high activity. X-ray crystallography studies show that the tridentate chelate 2-pyridylcarbaldehyde isonicotinoylhydrazone undergoes an unexpected oxidation to isonicotinoyl(picolinoyl)hydrazine when complexed with Fe-III. In contrast, in the absence of Fel the parent hydrazone is not oxidized in aerobic aqueous solution. To examine whether the diacylhydrazine could be responsible for the biological effects of 2-pyridylcarbaldehyde isonicotinoylhydrazone, their Fe chelation efficacy was compared. In contrast to its parent hydrazone, the diacylhydrazine showed little Fe chelation activity. Potentiometric titrations suggested that this might be because the diacylhydrazine was charged at physiological pH, hindering its access across membranes to intracellular Fe pools. In contrast, the Fe complex of this diacylhydrazine was charge neutral, which may allow facile movement through membranes. These data allow a model of Fe chelation for this compound to be proposed: the parent aroylhydrazone diffuses through cell membranes to bind Fe and is subsequently oxidized to the diacylhydrazine complex which then diffuses from the cell. Other diacylhydrazine analogues that were charge neutral at physiological pH demonstrated high Fe chelation efficacy. Thus, for this class of ligands, the charge of the chelator appears to be an important factor for determining their ability to access intracellular Fe. The results of this study are significant for understanding the biological activity of 2-pyridylcarbaldehyde isonicotinoylhydrazone and for the design of novel diacylhydrazine chelators for clinical use.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Many nonsteroidal anti-inflammatory drugs (NSAIDs) which have antiproliferative activity in colon cancer cells are carboxylate compounds forming acyl glucuronide metabolites. Acyl glucuronides are potentially reactive, able to hydrolyse, rearrange into isomers, and covalently modify proteins under physiological conditions. This study investigated whether the acyl glucuronides (and isomers) of the carboxylate NSAIDs diflunisal, zomepirac and diclofenac had antiproliferative activity on human adenocarcinoma. HT-29 cells in culture. Included as controls were the carboxylate NSAIDs themselves, the non-carboxylate NSAID piroxicam, and the carboxylate non-NSAID valproate, as well as its acyl glucuronide and isomers. The compounds were incubated at 1-3000 muM with HT-29 cells for 24 hr, with [H-3]-thymidine added for an additional 2 hr incubation. IC50 values were calculated from the concentration-inhibition response curves for thymidine uptake. The four NSAIDs inhibited thymidine uptake, with IC50 values about 200-500 muM. All of the NSAID acyl glucuronides (and isomers, tested in the case of diflunisal) showed antiproliferative activity broadly comparable to the parent drugs. This activity may stem from direct uptake of intact glucuronide/isomers followed by covalent modification of proteins critical in the cell replication process. However, hydrolysis during incubation and cellular uptake of liberated parent NSAID will play a role. In HT-29 cells incubated with zomepirac, covalently modified proteins in cytosol were detected by immunoblotting with a zomepirac antibody, suggesting that HT-29 cells do have the capacity to glucuronidate zomepirac. The anti-epileptic drug valproate had no effect on inhibition of thymidine uptake, though, surprisingly, its acyl glucuronide and isomers were active. The reasons for this are unclear at present. (C) 2001 Elsevier Science Inc. All rights reserved.