57 resultados para Average comparisons
Resumo:
Background Moderate di?erences in e?cacy between adjuvant chemotherapy regimens for breast cancer are plausible, and could a? ect treatment choices. We sought any such di?erences.
Methods We undertook individual-patient-data meta-analyses of the randomised trials comparing: any taxane-plusanthracycline-based regimen versus the same, or more, non-taxane chemotherapy (n=44 000); one anthracyclinebased regimen versus another (n=7000) or versus cyclo phosphamide, methotrexate, and ?uorouracil (CMF; n=18 000); and polychemotherapy versus no chemotherapy (n=32 000). The scheduled dosages of these three drugs and of the anthracyclines doxorubicin (A) and epirubicin (E) were used to de? ne standard CMF, standard 4AC, and CAF and CEF. Log-rank breast cancer mortality rate ratios (RRs) are reported.
Findings In trials adding four separate cycles of a taxane to a ?xed anthracycline-based control regimen, extending treatment duration, breast cancer mortality was reduced (RR 0·86, SE 0·04, two-sided signi?cance [2p]=0·0005). In trials with four such extra cycles of a taxane counterbalanced in controls by extra cycles of other cytotoxic drugs, roughly doubling non-taxane dosage, there was no signi?cant di?erence (RR 0·94, SE 0·06, 2p=0·33). Trials with CMF-treated controls showed that standard 4AC and standard CMF were equivalent (RR 0·98, SE 0·05, 2p=0·67), but that anthracycline-based regimens with substantially higher cumulative dosage than standard 4AC (eg, CAF or CEF) were superior to standard CMF (RR 0·78, SE 0·06, 2p=0·0004). Trials versus no chemotherapy also suggested greater mortality reductions with CAF (RR 0·64, SE 0·09, 2p<0·0001) than with standard 4AC (RR 0·78, SE 0·09, 2p=0·01) or
standard CMF (RR 0·76, SE 0·05, 2p<0·0001). In all meta-analyses involving taxane-based or anthracycline-based regimens, proportional risk reductions were little a? ected by age, nodal status, tumour diameter or di?erentiation (moderate or poor; few were well di?erentiated), oestrogen receptor status, or tamoxifen use. Hence, largely independently of age (up to at least 70 years) or the tumour characteristics currently available to us for the patients selected to be in these trials, some taxane-plus-anthracycline-based or higher-cumulative-dosage anthracycline-based regimens (not requiring stem cells) reduced breast cancer mortality by, on average, about one-third. 10-year overall mortality di?erences paralleled breast cancer mortality di?erences, despite taxane, anthracycline, and other toxicities.
Interpretation 10-year gains from a one-third breast cancer mortality reduction depend on absolute risks without chemotherapy (which, for oestrogen-receptor-positive disease, are the risks remaining with appropriate endocrine therapy). Low absolute risk implies low absolute bene?t, but information was lacking about tumour gene expression markers or quantitative immunohistochemistry that might help to predict risk, chemosensitivity, or both.
Resumo:
This analysis uses average length of stay as a proxy for efficiency, to compare the Australian private and public hospital sectors. We conclude that private hospitals are more efficient than public hospitals in providing the range of care provided by private hospitals. However, public hospitals are more efficient in handling the casemix of the public hospital sector. The picture is more complicated when particular types of care (such as obstetric and psychiatric) are excluded.
Resumo:
We used microsatellite DNA markers to identify the putative parents of 69 litters of nine-banded armadillos (Dasypus novemcinctus) over 4 years. Male and female parents did not differ in any measure of body size in comparisons with nonparents. However, males observed paired with a female were significantly larger than unpaired males, although paired females were the same size as unpaired females. Females categorized as possibly lactating were significantly larger than females that were either definitely lactating or definitely not lactating. There was no evidence of assortative mating: body-size measurements of mothers were not significantly correlated with those of fathers. Nine-banded armadillos give birth to litters of genetically identical quadruplets. Mothers (but not fathers) of female litters were significantly larger than mothers of male litters, and maternal (but not paternal) body size was positively correlated with the number of surviving young within years, but not cumulatively. There were no differences in dates of birth between male and female litters, nor were there any significant relationships between birth date and maternal body size. Body size of either parent was not correlated with the body sizes of their offspring. Cumulative and yearly reproductive success did not differ between reproductively successful males and females. Average reproductive success (which included apparently unsuccessful individuals) also did not differ between males and females. The majority of adults in the population apparently failed to produce any surviving offspring, and even those that did usually did so in only 1 of the 4 years. This low reproductive success is unexpected, given the rapid and successful range extension of this species throughout the southeastern United States in this century.
Resumo:
We use a simple average-atom model (NIMP) to calculate the distribution of ionization in a photoionization-dominated plasma, for comparison with recent experimental measurements undertaken on the Z-machine at the Sandia National Laboratory. The agreement between theory and experiment is found to be as good for calculations with an average-atom model as for those generated by more detailed models.
Resumo:
Abstract: Raman spectroscopy has been used for the first time to predict the FA composition of unextracted adipose tissue of pork, beef, lamb, and chicken. It was found that the bulk unsaturation parameters could be predicted successfully [R-2 = 0.97, root mean square error of prediction (RMSEP) = 4.6% of 4 sigma], with cis unsaturation, which accounted for the majority of the unsaturation, giving similar correlations. The combined abundance of all measured PUFA (>= 2 double bonds per chain) was also well predicted with R-2 = 0.97 and RMSEP = 4.0% of 4 sigma. Trans unsaturation was not as well modeled (R-2 = 0.52, RMSEP = 18% of 4 sigma); this reduced prediction ability can be attributed to the low levels of trans FA found in adipose tissue (0.035 times the cis unsaturation level). For the individual FA, the average partial least squares (PLS) regression coefficient of the 18 most abundant FA (relative abundances ranging from 0.1 to 38.6% of the total FA content) was R-2 = 0.73; the average RMSEP = 11.9% of 4 sigma. Regression coefficients and prediction errors for the five most abundant FA were all better than the average value (in some cases as low as RMSEP = 4.7% of 4 sigma). Cross-correlation between the abundances of the minor FA and more abundant acids could be determined by principal component analysis methods, and the resulting groups of correlated compounds were also well-predicted using PLS. The accuracy of the prediction of individual FA was at least as good as other spectroscopic methods, and the extremely straightforward sampling method meant that very rapid analysis of samples at ambient temperature was easily achieved. This work shows that Raman profiling of hundreds of samples per day is easily achievable with an automated sampling system.
Resumo:
Bradykinins and related peptides (BRPs) occur in the defensive skin secretions of many amphibians. Here we report the structures of BRPs and their corresponding biosynthetic precursor cDNAs from the Chinese brown frog, Rana chensinensis, and the North American leopard frog, Lithobates pipiens. R. chensinensis skin contained four transcripts each encoding a different kininogen whose organizations and spectrum of encoded BRPs were similar to those reported for the pickerel frog, Lithobates palustris. In contrast, from L. pipiens, a single skin kininogen was cloned whose structural organization and spectrum of mature BRPs were similar to those reported for the Chinese piebald odorous frog, Huia schmackeri. These data also implied that the endogenous precursor processing proteases in each species pair have identical site-directed specificities, which in part may be dictated by the primary structures of encoded BRPs. Thus the spectra of skin BRPs and the organization of their biosynthetic precursors are not consistent with recent taxonomy. The natural selective pressures that mould the primary structures of amphibian skin secretion peptides are thought to be related to the spectrum of predators encountered within their habitats. Thus similarities and differences in skin bradykinins may be reflective of predator spectra rather than indicative of species relatedness.
Resumo:
Objectives: Recent advances in mental health care policy and service delivery have lead to the development of community care initiatives which have enabled those individuals traditionally cared for in hospital environments to be resettled successfully in community living arrangements that foster an ethos of empowerment and recovery. This study sought to identify differences between a hospital continuing care group (n = 16) and a community placement group (n = 20) in relation to quality of life, satisfaction and levels of empowerment. Method: The study was a cross-sectional design. It follows up a cohort of individuals identified as the ‘hospital continuing care group’ (365+ consecutive days in psychiatric hospital care) by Homefirst Community Trust in Northern Ireland. A proportion of this population has been resettled into community care environments and some continue to reside in hospital. Patients both in the hospital continuing care group and the community placement group completed two standard questionnaires that covered a number of variables including empowerment, quality of life and service satisfaction. Results: There were significant differences between the hospital continuing care and community placement groups across scores on service satisfaction, quality of life, and empowerment in the current study. Hypotheses relating to service satisfaction (z = -4.117; p
Resumo:
Data are summarised for two Lagrangian experiments in the North Atlantic in early summer 1996. At 59 degreesN 20 degreesW, plankton dynamics was studied in an SF, tracer release experiment within a mesoscale eddy over a 9-day period. At 37 degreesN 20 degreesW, a second experiment followed a drifting buoy for 7 days. The data obtained in these two experiments have been averaged for 3 depth strata; the euphotic zone, the surface mixed layer (SML), and the seasonal thermocline immediately beneath the surface mixed layer. At 59 degreesN, the euphotic zone was only marginally deeper than the SML, but at 37 degreesN the SML was ca 30 m and the euphotic depth was ca 110 m. At 37 degreesN, nutrient concentrations in the SML were low but significant new production occurred in the thermocline because of light penetration into the nutricline. The particulate organic carbon (POC) concentration of the SML at 59 degreesN was 13-15 mu mol C kg(-1), but at 37 degreesN POC concentrations were 4 mu mol C kg(-1). These POC measurements include biota and detritus. As a way of investigating latitudinal differences in the plankton communities, estimates have been made of the carbon and nitrogen content of phytoplankton, bacterioplankton, microzooplankton and mesozooplankton. At both 59 degreesN and 37 degreesN, phytoplankton was the largest component, accounting for ca 50% of the planktonic biomass in the SML. At 59 degreesN, microzooplankton was 16% of the planktonic carbon, but at 37 degreesN this reduced to 8% of the total. Mesozooplankton was a relatively constant proportion (ca 20%) of the planktonic carbon in the SML at both 59 degreesN and 37 degreesN. Bacterioplankton was 14% of the biomass at 59 degreesN, increasing to 24% in the microbial loop-dominated system at 37 degreesN. Mean carbon fixation rate in the oligotrophic southern station was 24% of that at the north, with more carbon fixation below the SML at 37 degreesN than at 59 degreesN. Respiration rates showed little variation with latitude, and the rates at 37 degreesN were 80% of those at 59 degreesN. Nitrate and ammonium uptake rates were very low in the oligotrophic conditions in the SML at 37 degreesN, but nitrate uptake in the euphotic zone was comparable to that at 59 degreesN. Ammonium uptake by phytoplankton was also significantly greater at 37 degreesN, in both the euphotic zone and thermocline, but uptake in the SML was only 20% of that in the SML at 59 degreesN. (C) 2001 Elsevier Science Ltd. All rights reserved.