77 resultados para Harris, Alexandra
Resumo:
We previously showed that 16-day-old rats exposed to a relatively high dose of ethanol at 10-15 postnatal days of age have fewer neurons in the hilus region of the hippocampus compared with controls. Dentate gyrus granule cell numbers, however, showed no statistically significant changes attributable to the ethanol treatment. It is possible that some of the changes in brain morphology, brought about as a result of the exposure to ethanol during early life, may not be manifested until later in life. This question has been further addressed in an extension to our previous study. Wistar rats were exposed to a relatively high daily dose of ethanol on postnatal days 10-15 by placement in a chamber containing ethanol vapour, for 3 h/day. The blood ethanol concentration was found to be similar to430 mg/dl at the end of the period of exposure. Groups of ethanol-treated (ET), separation control (SC), and mother-reared control (MRC) rats were anaesthetised and killed either at 16 or 30 days of age by perfusion with phosphate-buffered 2.5% glutaraldehyde. The Cavalieri principle and the physical disector methods were used to estimate, respectively, the regional volumes and neuron cell numerical densities in the hilus and granule cell regions of the dentate gyrus. The total numbers of neurons in the hilus region and granule cell layer were computed from these estimates. It was found that 16-day-old animals had 398,000-441,000 granule cells, irrespective of group. The numbers of granule cells increased such that by 30 days of age, rats had 487,000-525,500 granule cells. However, there were no significant differences between ethanol-treated rats and their age-matched controls in granule cell numbers. In contrast, ethanol-treated rats had slightly but significantly fewer neurons in the hilus region than did control animals at 16 days of age, but not at 30 days of age. Therefore, it appears that a short period of ethanol exposure during early life can have effects on neuron numbers of some hippocampal neurons, but not others. The effects on hilar neuron numbers, observed as a result of such short periods of ethanol treatment, appeared to be transitory. (C) 2003 Wiley-Liss, Inc.
Resumo:
Estimating energy requirements is necessary in clinical practice when indirect calorimetry is impractical. This paper systematically reviews current methods for estimating energy requirements. Conclusions include: there is discrepancy between the characteristics of populations upon which predictive equations are based and current populations; tools are not well understood, and patient care can be compromised by inappropriate application of the tools. Data comparing tools and methods are presented and issues for practitioners are discussed. (C) 2003 International Life Sciences Institute.
Resumo:
We have previously shown that exposing rats to a relatively high dose of ethanol during early postnatal life can result in an alteration in spatial learning ability. The hippocampal formation is known to be involved in the control of this ability. The purpose of the present study was to determine whether exposure of rats to ethanol during early postnatal life had either immediate or delayed effects on the numbers of pyramidal cells in the CA1-CA3 subregion of the hippocampus. Wistar rats were exposed to a relatively high daily dose of ethanol at postnatal day 10-15 by placing them for 3 h/day in a chamber containing ethanol vapor. Groups of ethanol-treated (ET), separation control (SC), and mother-reared control (MRC) rats were anesthetized and killed at 16 and 30 days of age by perfusion with phosphate-buffered 2.5% glutaraldehyde. The Cavalieri principle was used to determine the volumes of the CA1 and CA2+CA3 regions. The physical disector method was used to estimate the numerical density of neurons in each of the subdivisions. The total number of pyramidal cells was calculated by multiplying the appropriate estimates of the numerical density by the volume. There were significant age-related reductions in the total numbers of pyramidal cells at 16-30 days of age irrespective of the groups examined. Ethanol treated rats were found to have slightly but significantly fewer pyramidal cell neurons than either the MRC or SC groups. These observations indicate that pyramidal cells in the hippocampus may be vulnerable to a relatively high dose of ethanol exposure during this short period of early postnatal life. (C) 2003 Wiley-Liss, Inc.
Resumo:
Epithelial malignancies are common in immunosuppressed individuals and the general population. However the mechanisms by which the adaptive immune system can eliminate immunogenic epithelial cells remain undefined. The aim of this project was to determine the effector molecules required for induction of apoptosis in murine epidermal keratinocytes (MEKs) in vitro and in vivo. HPV16E7-specific CTL lines and T cell receptor transgenic (E7TCRtg) effector cells were obtained from wild type (wt)-C57 and syngeneic mice rendered functionally inactive for perforin (Pfp), interferon-g (IFN-g) or FasL. CTLs or E7TCRtg spleen cells were co-cultured with primary MEKs in vitro or transferred into skin graft recipients. Inhibition of colony formation and skin graft rejection were used as indicators of T cell:KC interaction. Wt E7-specific CTLs and CTLs deficient in perforin, FasL or IFN-g produced mean reductions in colony formation of 67% (62.4–71.3%), 72% (71.1–72%), 76% (73–78%) and 21.5% (14– 34%) respectively. Wt, perforin deficient or FasL deficient CTLs all induced rejection of skin grafts (wt: 6/12; Pfp: 9/15; FasL: 3/13 survival). Transfer and immunisation of wt E7TCRtg spleen cells induces rejection of 50% of grafts (4/8 survival). In contrast, perforin or IFN-g deficient E7TCRtg failed to induce graft rejection (5/6; 4/4 survival). FasL deficient E7TCRtg induced nonspecific rejection of grafts (E7- 2/6 survival; C57- 4/7 survival). Therefore IFN-g production by CTL is necessary and sufficient in vitro and in vivo to kill epithelial cells which express a nonself antigen. Assessment of immunotherapies directed against epithelial tissues may be more effectively achieved by assaying the amount of IFN-g production by CD8 T cells, and the number and affinity of those cells, in conjunction with quantitation of perforin mediated effects in short term assays.
Resumo:
Objective: To examine the quality of diabetes care and prevention of cardiovascular disease (CVD) in Australian general practice patients with type 2 diabetes and to investigate its relationship with coronary heart disease absolute risk (CHDAR). Methods: A total of 3286 patient records were extracted from registers of patients with type 2 diabetes held by 16 divisions of general practice (250 practices) across Australia for the year 2002. CHDAR was estimated using the United Kingdom Prospective Diabetes Study algorithm with higher CHDAR set at a 10 year risk of >15%. Multivariate multilevel logistic regression investigated the association between CHDAR and diabetes care. Results: 47.9% of diabetic patient records had glycosylated haemoglobin (HbA1c) >7%, 87.6% had total cholesterol >= 4.0 mmol/l, and 73.8% had blood pressure (BP) >= 130/85 mm Hg. 57.6% of patients were at a higher CHDAR, 76.8% of whom were not on lipid modifying medication and 66.2% were not on antihypertensive medication. After adjusting for clustering at the general practice level and age, lipid modifying medication was negatively related to CHDAR (odds ratio (OR) 0.84) and total cholesterol. Antihypertensive medication was positively related to systolic BP but negatively related to CHDAR (OR 0.88). Referral to ophthalmologists/optometrists and attendance at other health professionals were not related to CHDAR. Conclusions: At the time of the study the diabetes and CVD preventive care in Australian general practice was suboptimal, even after a number of national initiatives. The Australian Pharmaceutical Benefits Scheme (PBS) guidelines need to be modified to improve CVD preventive care in patients with type 2 diabetes.
Resumo:
This paper reports on an investigation into the teaching of medical ethics and related areas in the medical undergraduate course at the University of Queensland. The project was designed in the context of a major curriculum change to replace the current 6 year course by an integrated, problem-based, 4 year graduate medical course, which began in 1997. A survey of clinical students, observations of clinical teaching sessions, and interviews with clinical teachers were conducted. Data obtained have contributed to curriculum development and will provide a baseline for comparison and evaluation of the graduate course in this field. A view of integrated ethics teaching is advanced in the light of the data obtained.