995 resultados para Differential kinetics
Resumo:
Previous work has suggested that decrement in both processing speed and working memory span plays a role in the memory impairment observed in patients with schizophrenia. We undertook a study to examine simultaneously the effect of these two factors. A sample of 49 patients with schizophrenia and 43 healthy controls underwent a battery of verbal and visual memory tasks. Superficial and deep encoding memory measures were tallied. We conducted regression analyses on the various memory measures, using processing speed and working memory span as independent variables. In the patient group, processing speed was a significant predictor of superficial and deep memory measures in verbal and visual memory. Working memory span was an additional significant predictor of the deep memory measures only. Regression analyses involving all participants revealed that the effect of diagnosis on all the deep encoding memory measures was reduced to non-significance when processing speed was entered in the regression. Decreased processing speed is involved in verbal and visual memory deficit in patients, whether the task require superficial or deep encoding. Working memory is involved only insofar as the task requires a certain amount of effort. (JINS, 2011, 17, 485-493)
Resumo:
Altered expression of histone deacetylases (HDACs) is a common feature in several human malignancies and may represent an interesting target for cancer treatment, including haematological malignancies. We evaluated the mRNA gene expression profile of 12 HDAC genes by quantitative real-time polymerase chain reaction in 94 consecutive childhood acute lymphoblastic leukaemia (ALL) samples and its association with clinical/biological features and survival. ALL samples showed higher expression levels of HDAC2, HDAC3, HDAC8, HDAC6 and HDAC7 when compared to normal bone marrow samples. HDAC1 and HDAC4 showed high expression in T-ALL and HDAC5 was highly expressed in B-lineage ALL. Higher than median expression levels of HDAC3 were associated with a significantly lower 5-year event-free survival (EFS) in the overall group of patients (P = 0.03) and in T-ALL patients (P = 0.01). HDAC7 and HADC9 expression levels higher than median were associated with a lower 5-year EFS in the overall group (P = 0.04 and P = 0.003, respectively) and in B-lineage CD10-positive patients (P = 0.009 and P = 0.005, respectively). Our data suggest that higher expression of HDAC7 and HDAC9 is associated with poor prognosis in childhood ALL and could be promising therapeutic targets for the treatment of refractory childhood ALL.
Resumo:
Galectin-3 (Gal-3) is a glycan-binding protein highly expressed in several tumors, including brain neoplasms. This protein has been demonstrated to be correlated with adverse prognosis in some tumor types. However, the role of Gal-3 in pediatric posterior fossa tumors (PPFTs) has not yet been fully addressed. The goals of this study were to evaluate Gal-3 expression in a series of PPFTs and verify whether this expression is related to patient outcome. Gal-3 expression was analyzed by immunohistochemistry in 42 cases of surgically resected primary PPFTs. Surgeries were performed in our institution from January 2003 to December 2006. Tumor samples consisted of 21 pilocytic astrocytomas (PAs), 13 medulloblastomas, 4 ependymomas, 2 diffuse cerebellar astrocytomas, and 2 atypical teratoid/rhabdoid tumors (AT/RTs). All PAs and ependymomas strongly showed Gal-3 expression, whereas no immunostaining was observed in medulloblastomas and diffuse astrocytomas. In AT/RTs, Gal-3 expression was conspicuous but heterogeneous, being mainly observed in rhabdoid cells. Concerning the Gal-3 expressing tumors, no relationship was observed between the degree of expression and patient survival. Gal-3 was strongly expressed in reactive astrocytes, normal endothelial cells, and macrophages in the adjacent non-neoplastic brain parenchyma. Interestingly, the endothelial cells in the tumor bulk of PAs lacked Gal-3 expression. Gal-3 is differentially expressed in PPFTs, but its expression shows no correlation with patient outcome. However, the evaluation of Gal-3 is helpful in establishing a differential diagnosis among PPFTs, especially between PAs and diffuse astrocytomas, and in some circumstances between medulloblastomas and AT/RTs.
Resumo:
Organisms of the genera Toxoplasma, Hammondia and Neospora, the Hammondia-like organisms, are closely related coccidian with similarly sized oocysts. Therefore, a diagnosis based on microscopy of oocysts in feces is not a method of choice for species identification of these important parasites. In this paper, we present a polymerase chain reaction coupled with restriction fragment length polymorphism (PCR-RFLP) method to differentially diagnose oocysts of Toxoplasma gondii from oocyst of Hammondia hammondi. Another PCR-RFLP was designed to differentiate oocysts of Hammondia heydorni from oocysts of Neospora spp. Both PCR-RFLP are based on nucleotide sequences of the Hsp70 coding gene. In conclusion, we presented two alternative molecular diagnostic assays that can be successfully applied for the differentiation of oocysts of Hammondia-like organisms shed by felids and canids.
Resumo:
A matricial method to solve the decay chain differential equations system is presented. The quantity of each nuclide in the chain at a time t may be evaluated by analytical expressions obtained in a simple way using recurrence relations. This method may be applied to problems of radioactive buildup and decay and can be easily implemented computationally. (C) 2009 Elsevier B.V. All rights reserved.
Phosphorus kinetics in calves experimentally submitted to a trickle infection with Cooperia punctata
Resumo:
Ten male Holstein calves (74.3 +/- 3.2 kg LW) were used for a trial with trickle infection with Cooperia punctata to evaluate phosphorus (P) kinetics. Five calves were inoculated with 10,000 L(3) stage larvae per week during 35 days, while the other group of five calves was kept as a control. On the 29th day each calf was intravenously injected with 29.6 MBq of a (32)p solution. Blood samples were taken at 24 h periods for 7 days, after which all calves were slaughtered and worms burdens. Faeces, urine and tissue samples were taken for analysis using isotopic dilution and modeling techniques. The number of eggs per gram of faeces (EPG)was 1920 +/- 168 on 28th day and the total number of worms burdens was 11,131 +/- 1500. Infected calves showed lower feed intake and live weight gain, as well as lower P intake, absorption and retention than control calves. The P flows between body compartments were lower for blood to gastrointestinal tract (TGI), TGI to blood, blood to soft tissues, bone balance and soft tissue balance in infected calves when compared to the control. The trickle infection of C punctata affected P metabolism due to the decrease in P retained and live weight due to fall in feed intake. (C) 2009 Elsevier B.V. All rights reserved.
Resumo:
Prostate growth and physiology are regulated by steroid hormones and modulated by multiple endocrine factors We investigated the action of insulin on the tissue organization and kinetics of epithelial cells in the rat ventral prostate (VP) in response to castration up to 120 hours after surgery by using an acute protocol of alloxan induced diabetes Diabetes caused a reduction in volume density (Vv(o)/) and volume of the epithelium The effects of castration on the epithelium were accelerated in the diabetic animals as determined by changes in V(o)/, and volume The smooth muscle cells became atrophic and apparently relaxed in response to castration in contrast to the spinous aspect observed in nondiabetic castrated rats Counting of apoptotic nuclei in the epithelium showed the classical apoptosis peak at 72 hours in nondiabetic rats and an advance of the apoptosis peak to 48 hours after castration in diabetic rats Insulin restored the time of the peak to 72 hours These results were confirmed after immunostaining for cleaved caspase 3 and suggest a survival and antiapoptotic effect on VP epithelial cells in both the presence and absence of androgen stimulation This idea is supported by the observation that insulin also reduced the overall rate of apoptosis at all experimental points analyzed before and after castration
Resumo:
The vomeronasal system is crucial for social and sexual communication in mammals. Two populations of vomeronasal sensory neurons, each expressing G alpha i2 or G alpha o proteins, send projections to glomeruli of the rostral or caudal accessory olfactory bulb, rAOB and cAOB, respectively. In rodents, the G alpha i2- and G alpha o-expressing vomeronasal pathways have shown differential responses to small/volatile vs. large/non-volatile semiochemicals, respectively. Moreover, early gene expression suggests predominant activation of rAOB and cAOB neurons in sexual vs. aggressive contexts, respectively. We recently described the AOB of Octodon degus, a semiarid-inhabiting diurnal caviomorph. Their AOB has a cell indentation between subdomains and the rAOB is twice the size of the cAOB. Moreover, their AOB receives innervation from the lateral aspect, contrasting with the medial innervation of all other mammals examined to date. Aiming to relate AOB anatomy with lifestyle, we performed a morphometric study on the AOB of the capybara, a semiaquatic caviomorph whose lifestyle differs remarkably from that of O. degus. Capybaras mate in water and scent-mark their surroundings with oily deposits, mostly for male-male communication. We found that, similar to O. degus, the AOB of capybaras shows a lateral innervation of the vomeronasal nerve, a cell indentation between subdomains and heterogeneous subdomains, but in contrast to O. degus the caudal portion is larger than the rostral one. We also observed that four other caviomorph species present a lateral AOB innervation and a cell indentation between AOB subdomains, suggesting that those traits could represent apomorphies of the group. We propose that although some AOB traits may be phylogenetically conserved in caviomorphs, ecological specializations may play an important role in shaping the AOB.
Resumo:
Hamartoma is a proliferation of normal tissues that are considered endogenous to the site of occurrence. In the head and neck region, hamartomas composed of other tissues different from blood and lymphatic vessels (hemangiomas and lymphangiomas) are very uncommon. We report an unusual case of upper lip angiomyolipomatous hamartoma in an 8-month-old patient. The patient underwent surgical treatment and the 1-year follow-up revealed no signs of recurrence. Angiomyolipomatous hamartoma is a very rare condition in the paediatric population group, especially in the head and neck region. It should be considered in the differential diagnosis of congenital lesions in childhood. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.
Resumo:
In this study, Bmp-4, Wnt-5a and Shh gene expressions were compared during early craniofacial development in mice by comparative non-isotopic in situ hybridization. Wild-type C57BL/6J mice were studied at various stages of embryonic development (from 8.5- to 13.5-day-old embryos - E8.5-13.5). During early odontogenesis, transcripts for Bmp-4, Shh and Wnt-5a were co-localised at the tooth initiation stage. At E8.5, Shh mRNA expression was restricted to diencephalon and pharyngeal endoderm. Before maxillae and mandible ossification, Bmp-4 and Wnt-5a signals were detected in the mesenchymal cells and around Meckel`s cartilage. During palatogenesis, Shh was expressed only in the epithelium and Wnt-5a only in the mesenchyme of the elevating palatal shelves. During tongue development, Shh expression was found in mesenchyme, probably contributing to tongue miogenesis, while Wnt-5a signal was in the epithelium, possibly during placode development and papillae formation. Taken together, these findings suggest that Bmp-4, Shh and Wnt-5a gene expressions may act together on the epithelial mesenchymal interactions occurring in several aspects of the early mouse craniofacial development, such as odontogenesis, neuronal development, maxillae and mandible ossification, palatogenesis and tongue formation. (C) 2009 Elsevier GmbH. All rights reserved.
Resumo:
Background: Galectin-3 has been implicated in tumor progression of some malignancies as thyroid, prostate, and salivary gland tumors. Recently, it has been suggested that this protein may be an important mediator of the beta-catenin/Wnt pathway. Moreover, nuclear galectin-3 expression has been implicated in cell proliferation, promoting cyclin D1 activation. Thus, the present study aimed to correlate galectin-3 expression with beta-catenin and cyclin D1 expressions in adenoid cystic carcinoma (ACC) and in polymorphous low-grade adenocarcinoma (PLGA). Methods: Fifteen formalin-fixed paraffin-embedded cases of each tumor were retrieved from the files of the Surgical Oral Pathology Service at the University of Sao Paulo and the proteins were analyzed by immunohistochemistry. Results: Adenoid cystic carcinoma showed galectin-3 immunostaining mainly in the nuclei, while PLGA revealed a positive mostly cytoplasmic reaction to galectin-3 in the largest part of tumor cells. Both tumors showed intense cytoplasmic/nuclear staining for beta-catenin in majority of cases. Cyclin D1 immunoreactivity was not detected in 14/15 PLGA and showed specific nuclear staining in 10/15 cases of ACC in more than 5% of the neoplastic cells. Cyclin D1 expression was correlated with cytoplasmic and nuclear galectin-3 expression in ACC (P < 0.05). Conclusions: These results suggest that in ACC galectin-3 may play a role in cellular proliferation through cyclin D1 activation. In addition, nuclear expression of galectin-3 in ACC may be related to a more aggressive behavior of this lesion. Although beta-catenin seems to play a role in carcinogenesis in both lesions, it seems that it does not bind to galectin-3 for cyclin D1 stimulation.
Resumo:
Polymerization stress development results from the complex interplay of volumetric shrinkage, reaction kinetics, and viscoelastic properties. The objective of this study was to examine the relationships among volumetric shrinkage, degree of conversion, rate of polymerization (RPmax), and stress development for 2 model bis-GMA-based composites. Three irradiances were used 220, 400, or 600 mW/cm(2) - with exposure times adjusted to deliver the same radiant energy. Volumetric shrinkage was determined with a mercury dilatometer, degree of conversion and RPmax by differential scanning calorimetry (DSC), and polymerization stress with a low-compliance device (Sakaguchi et al., 2004b). Results indicated that polymerization reaction rate and shrinkage were not correlated. Irradiance was directly related to polymerization reaction rate and to stress development. The group with the highest stress/degree of conversion exhibited the lowest RPmax, so it can be assumed, within the limitations of this study, that the conversion was most closely related to stress development.
Resumo:
The influence of composite organic content on polymerization stress development remains unclear. It was hypothesized that stress was directly related to differences in degree of conversion, volumetric shrinkage, elastic modulus, and maximum rate of polymerization encountered in composites containing different BisGMA (bisphenylglycidyl dimethacrylate) concentrations and TEGDMA ( triethylene glycol dimethacrylate) and/or BisEMA ( ethoxylated bisphenol-A dimethacrylate) as co-monomers. Stress was determined in a tensilometer. Volumetric shrinkage was measured with a mercury dilatometer. Elastic modulus was obtained by flexural test. We used fragments of flexural specimens to determine degree of conversion by FT-Raman spectroscopy. Reaction rate was determined by differential scanning calorimetry. Composites with lower BisGMA content and those containing TEGDMA showed higher stress, conversion, shrinkage, and elastic modulus. Polymerization rate did not vary significantly, except for the lower value of the 66% TEGDMA composite. We used linear regressions to evaluate the association between polymerization stress and conversion (R-2 = 0.905), shrinkage ( R-2 = 0.825), and modulus ( R-2 = 0.623).
Resumo:
This study evaluated the kinetics of fluoride in plasma, femur surface and the whole femur of rats, after chronic exposure to different water fluoride levels was interrupted. Four groups of Wistar rats received drinking water containing 0, 5, 15 or 50 mu g F/ml for 60 days (n = 50/group). The animals were euthanized immediately after exposure to fluoride or after 7, 30, 90 or 180 days (n = 10/subgroup). Plasma and femurs were collected. Fluoride on the femur surface, whole femur and plasma was analyzed with an electrode. Data were analyzed using ANOVA and Tukey`s test (p < 0.05). The increase in plasma fluoride levels was significant only for the 50 mu g F/ml group at 0 and 7 days. Regarding bone surface and whole bone, for most groups, significant increases in fluoride concentrations were observed with the increase in water fluoride concentrations at each time of euthanasia. For fluoride doses up to 15 mu g F/ml, femur surface fluoride levels were reestablished 180 days after the exposure was discontinued, which Was not valid for whole femur or for higher fluoride doses. We found a different kinetics of fluoride in plasma,femur surface and the whole femur of rats after chronic exposure to fluoride is interrupted. Copyright 2008 Prous Science, S.A.U. or its licensors. All rights reserved.