825 resultados para Autism spectrum disorders
Resumo:
In the present study we evaluated the toxic effects on the male adult rat prostate of DBP exposure during fetal and lactational periods, because although many studies have addressed the influence of phthalates on the male reproductive system, only a few have discussed their possible effects on prostate development. Pregnant females were distributed into two experimental groups: Control (C) and Treated (T). The females of the T group received DBP (100 mg/kg, by gavage) from gestation day 12 to postnatal day 21, while C rats received the vehicle (corn oil). In adulthood (90 days old), the animals were euthanized. The serum and testicular testosterone levels were measured. Ventral prostate was removed and weighed. Distal segment fragments of the ventral prostate were fixed and processed for histochemistry and immunohistochemistry to detect androgen receptor (AR) and Ki67 antigens. Protein extraction from ventral prostate fragments was performed for AR immunoblotting and Gelatin zymography for MMP-2 and MMP-9 (MMP, metalloproteinase). Stereological and histopathological analyses were also performed. Serum and testicular testosterone levels and prostate weight were comparable between groups. In the T group the relative proportions (%) of epithelial (C=32.86; T=42.04*) and stromal (C=21.61; T=27.88*) compartments were increased, while the luminal compartment was decreased (C=45.54; T=30.08*), *p < 0.05. In T, disseminated inflammatory infiltrate in the stroma, associated or not with epithelial dysplasia and PIN (Prostatic Intraepithelial Neoplasia), was observed. Increases in AR expression, proliferation index and metalloproteinase 9 (MMP-9) activity were noted in T animals. In some T animals, collagen fibrils accumulated adjacent to the epithelium. As far as we are aware, this is the first report in the literature showing that phthalates could play a role in proliferative and inflammatory disorders of the rat prostate. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
The research diagnostic criteria for temporomandibular disorders (RDC/TMD) are used for the classification of patients with temporomandibular disorders (TMD). Surface electromyography of the right and left masseter and temporalis muscles was performed during Maximum teeth clenching in 103 TMD patients subdivided according to the RDC/TMD into 3 non-overlapping groups: (a) 25 myogenous; (b) 61 arthrogenous; and (c) 17 psycogenous patients. Thirty-two control subjects matched for sex and age were also measured. During clenching, standardized total muscle activities (electromyographic potentials over time) significantly differed: 131.7 mu V/mu V s % in the normal subjects, 117.6 mu V/mu V s % in the myogenous patients, 105.3 mu V/mu V s % in the arthrogenous patients, 88.7 mu V/mu V s % in the psycogenous patients (p < 0.001, analysis of covariance). Symmetry in the temporalis muscles was larger in normal subjects (86.3%) and in myogenous patients (84.9%) than in arthrogenous (82.7%), and psycogenous patients (80.5%) (p=0.041). No differences were found for masseter muscle symmetry and torque coefficient (p>0.05). Surface electromyography of the masticatory muscles allowed an objective discrimination among different RDC/TMD subgroups. This evaluation could assist conventional clinical assessments. (C) 2007 Elsevier Ltd. All rights reserved.
Resumo:
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leucoencephalopathy (CADASIL) is a recently described cause of stroke or stroke-like episodes. It is caused by mutations in the Notch3 gene on chromosome 19p. We sought to demonstrate mutations of the Notch3 gene in Australian patients suspected of having CADASIL. Patients from several families were referred to the study. A diagnosis was determined clinically and by neuroimaging. Those suspected of having CADASIL had sequencing of exons 3 and 4 of the Notch3 gene. Eight patients, two of whom were siblings, were suspected of having CADASIL. Five patients (including the siblings) had mutations. Because of strong clustering of Notch3 mutations in CADASIL, this has potential as a reliable test for the disease in Australian patients. (C) 2001 Harcourt Publishers Ltd.
Resumo:
p73 has recently been identified as a structural and functional homolog of the tumor suppressor protein p53. Overexpression of p53 activates transcription of p53 effector genes, causes growth inhibition and induced apoptosis. We describe here the effects of a tumor-derived truncated transcript of p73 alpha (p73 Delta exon2) on p53 function and on cell death. This transcript, which lacks the acidic N-terminus corresponding to the transactivation domain of p53, was initially detected in a neuroblastoma cell line. Overexpression of p73 Delta exon2 partially protects lymphoblastoid cells against apoptosis induced by anti-Fas antibody or cisplatin. By cotransfecting p73 Delta exon2 with wild-type p53 in the p53 null line Saos 2, we found that this truncated transcript reduces the ability of wild-type p53 to promote apoptosis. This anti-apoptotic effect was also observed when p73 Delta exon2 was co-transfected with full-length p73 (p73 alpha). This was further substantiated by suppression of p53 transactivation of the effector gene p21-Waf1 in p73 Delta exon2 transfected cells and by inhibition of expression of a reporter gene under the control of the p53 promoter. Thus, this truncated form of p73 can act as a dominant-negative agent towards transactivation by p53 and p73 alpha, highlighting the potential implications of these findings for p53 signaling pathway. Furthermore, we demonstrate the existence of a p73 Delta exon2 transcript in a very significant proportion (46%) of breast cancer cell lines. However, a large spectrum of normal and malignant tissues need to be surveyed to determine whether this transdominant p73 variant occurs in a tumor-specific manner.
Resumo:
Although extended-spectrum beta-lactamases (ESBLs) hydrolyze cephalosporin antibiotics, some ESBL-producing organisms are not resistant to all cephalosporins when tested in vitro. Some authors have suggested that screening klebsiellae or Escherichia coli for ESBL production is not clinically necessary, and when most recently surveyed the majority of American clinical microbiology laboratories did not make efforts to detect ESBLs, We performed a prospective, multinational study of Klebsiella pneumoniae bacteremia and identified 10 patients who were treated for ESBL-producing K. pneumoniae bacteremia with cephalosporins and whose infecting organisms were not resistant in vitro to the utilized cephalosporin. In addition, we reviewed 26 similar cases of severe infections which had previously been reported. Of these 36 patients, 4 had to be excluded from analysis. Of the remaining 32 patients, 100% (4 of 4) patients experienced clinical failure when MICs of the cephalosporin used for treatment were in the intermediate range and 54% (15 of 28) experienced failure when MICs of the cephalosporin used for treatment were in the susceptible range, Thus, it is clinically important to detect ESBL production by klebsiellae or E, coli even when cephalosporin MICs are in the susceptible range (less than or equal to 8 mug/ml) and to report ESBL-producing organisms as resistant to aztreonam and all cephalosporins (with the exception of cephamycins).
Resumo:
Sunscreens penetrate human epidermis and modify the biology of proliferating cells. This study addressed the question whether the UV response of cultured human cells is affected by direct treatment with nontoxic levels of sunscreens. Cell survival following exposure to UVC or unfiltered UVB was not altered by preincubation with 25 μg/mL of octyl p-dimethylaminobenzoate (o-PABA), 2-ethylhexyl p-methoxycinnamate (EHMC) or oxybenzone. However, UVA or UVB filtered to reproduce the solar UV spectrum penetrating to the basal layer of the epidermis, highly sensitized cells to killing by o-PABA but not by its hydrolysis product, 4-dimethylaminobenzoic acid. Sensitization was found in all cell types tested, except normal keratinocytes, and could be prevented by certain antioxidants particularly pyruvate and the hydroxyl radical scavenger mannitol. o-PABA and EHMC applied without UV reduced the adherence of cells. The results indicate that sunscreens may increase cell mobility and the combination of o-PABA with solar UV may selectively damage melanocytes in the skin.
Resumo:
We investigate the fluorescence spectrum of a two-level atom driven by a multiple amplitude-modulated field. The driving held is modeled as a polychromatic field composed of a strong central (resonant) component and a large number of symmetrically detuned sideband fields displaced from the central component by integer multiples of a constant detuning. Spectra obtained here differ qualitatively from those observed for a single pair of modulating fields [B. Blind, P.R. Fontana, and P. Thomann, J. Phys. B 13, 2717 (1980)]. In the case of a small number of the modulating fields, a multipeaked spectrum is obtained with the spectral features located at fixed frequencies that are independent of the number of modulating fields and their Rabi frequencies. As the number of the modulating fields increases, the spectrum ultimately evolves to the well-known Mellow triplet with the sidebands shifted from the central component by an effective Rabi frequency whose magnitude depends on the initial relative phases of the components of the driving held. For equal relative phases, the effective Rabi frequency of the driving field can be reduced to zero resulting in the disappearance of fluorescence spectrum, i.e., the atom can stop interacting with the field. When the central component and the modulating fields are 180 degrees out of phase, the spectrum retains its triplet structure with the sidebands located at frequencies equal to the sum of the Rabi frequencies of the component of the driving field. Moreover, we shaw that the frequency of spontaneous emission can be controlled and switched from one frequency to another when the Rabi frequency or initial phase of the modulating fields are varied.
Resumo:
Hypovitaminosis D is a candidate risk-modifying factor for a diverse range of disorders apart from rickets and osteoporosis. Based on epidemiology, and on in vitro and animal experiment, vitamin D has been linked to multiple sclerosis, certain cancers (prostate, breast and colorectal), insulin-dependent diabetes mellitus and schizophrenia. I hypothesise that low pre- and perinatal vitamin D levels imprint on the functional characteristics of various tissues throughout the body, leaving the affected individual at increased risk of developing a range of adult-onset disorders. The hypothesis draws from recent advances in our understanding of the early origin of adult disease and proposes a 'critical window' during which vitamin D levels may have a persisting impact on adult health outcomes. Methods to test the hypothesis are outlined. If correct, the hypothesis has important implications for public health. Careful attention to maternal vitamin D status could translate into diverse improvements in health outcomes for the following generation. (C) 2001 Harcourt Publishers Ltd.
Resumo:
Primary immunodeficiency disorders in childhood usually present as unusual, recurrent or severe infections, symptomatic infections with organisms of low pathogenicity, or as recognizable syndromes which are known to have associated immunological abnormalities. In many of the primary immunodeficiency disorders, there are known patterns of inheritance, and other family members may be affected. Some primary immunodeficiency disorders are relatively common, such as selective IgA deficiency, and often do not lead to major morbidity. Others, such as the severe combined immune deficiency syndromes, are relatively rare, and are fatal in early life if not recognized and treated early. Diagnosis of a primary immunodeficiency disorder depends on appropriate use of laboratory investigations. Often there will be abnormalities detected on a complete blood film and measurement of immunoglobulin isotypes. More complex investigations should be undertaken in conjunction with a paediatric immunology service. In recent years, many of the clinically defined primary immunodeficiency disorders have been shown to have associated specific gene defects. For some, this has led to the identification and characterization of defective or absent gene products. The consequences of this new knowledge are more accurate diagnosis, early diagnosis including antenatal diagnosis, detection of undiagnosed disease in other family members, and the potential for new therapies including gene or gene product therapy.
Resumo:
A pairing model for nucleons, introduced by Richardson in 1966, which describes proton-neutron pairing as well as proton-proton and neutron-neutron pairing, is re-examined in the context of the quantum inverse scattering method. Specifically, this shows that the model is integrable by enabling the explicit construction of the conserved operators. We determine the eigenvalues of these operators in terms of the Bethe ansatz, which in turn leads to an expression for the energy eigenvalues of the Hamiltonian.
Resumo:
There have been few replicated examples of genotype x environment interaction effects on behavioral variation or risk of psychiatric disorder. We review some of the factors that have made detection of genotype x environment interaction effects difficult, and show how genotype x shared environment interaction (GxSE) effects are commonly confounded with genetic parameters in data from twin pairs reared together. Historic data on twin pairs reared apart can in principle be used to estimate such GxSE effects, but have rarely been used for this purpose. We illustrate this using previously published data from the Swedish Adoption Twin Study of Aging (SATSA), which suggest that GxSE effects could account for as much as 25% of the total variance in risk of becoming a regular smoker. Since few separated twin pairs will be available for study in the future, we also consider methods for modifying variance components linkage analysis to allow for environmental interactions with linked loci.
Resumo:
Handedness, as a potentially influencing, nonpathologic factor, has not been investigated in relation to transient evoked otoacoustic emissions (TEOAEs). The present study aimed to examine the effects of handedness on the TEOAE spectrum in entry-level schoolchildren, with attention also to possible ear asymmetry. A total of 228 subjects (114 males, 114 females, mean age = 6.3 years) were tested using the ILO292 Otodynamics Analyzer (Quickscreen mode) in quiet rooms in 22 schools. For statistical analysis, subjects were matched for factors such as handedness, gender, age, and history of recent ear infection. The results from subjects with passing TEOAE, pure-tone screening, and tympanometry revealed no significant handedness effect overall, although a significant ear asymmetry effect on the measurement parameters of AB difference, noise level, response level, whole-wave reproducibility, band reproducibility, and signal-to-noise ratios was found.