Outcome after extended follow-up in a prospective study of operable breast cancer: key factors and a prognostic index

In 1990, 215 patients with operable breast cancer were entered into a prospective study of the prognostic significance of five biochemical markers and 15 other factors (pathological/chronological/patient). After a median follow-up of 6.6 years, there were 77 recurrences and 77 deaths (59 breast cancer-related). By univariate analysis, patient outcome related significantly to 13 factors. By multivariate analysis, the most important of nine independent factors were: number of nodes involved, steroid receptors (for oestrogen or progestogen), age, clinical or pathological tumour size and grade. Receptors and grade exerted their influence only in the first 3 years. Progestogen receptors (immunohistochemical) and oestrogen receptors (biochemical) were of similar prognostic significance. The two receptors were correlated (r=+0.50, P=0.001) and displaced each other from the analytical model but some evidence for the additivity of their prognostic values was seen when their levels were discordant

Acoustic telemetry reveals strong spatial preferences and mixing during successive spawning periods in a partially migratory common bream population

Partial migration, whereby a population comprises multiple behavioural phenotypes that each have varying tendencies to migrate, is common among many animals. Determining the mechanisms by which these phenotypes are maintained is important for understanding their roles in population structure and stability. The aim here was to test for the temporal and spatial consistency of migratory phenotypes in a common bream Abramis brama (‘bream’) population, and then determine their social preferences and extent of mixing across three successive annual spawning periods. The study applied passive acoustic telemetry to track the movements of bream in the River Bure system of the Norfolk Broads, a lowland wetland comprising highly connected riverine and lacustrine habitats. Analyses revealed that individual migratory phenotype was highly consistent across the three years, but this was not predicted by fish sex or length at tagging. During the annual spawning periods, network analyses identified off-channel areas visited by both resident and migrant fish that, in non-spawning periods, were relatively independent in their space use. Within these sites, the co-occurrence of bream was non-random, with individuals forming more preferred and avoided associations than expected by chance. These associations were not strongly predicted by similarity in fish length, sex or behavioural phenotype, indicating that the resident and migrant phenotypes mixed during their annual spawning periods. The results suggested these different phenotypes, with spatially distinct resource use in non-spawning periods, comprised a single metapopulation, with this having important implications for the management of this wetland resource

In Silico-Enhanced Treatment and Rehabilitation Planning for Patients with Musculoskeletal Disorders: Can Musculoskeletal Modelling and Dynamic Simulations Really Impact Current Clinical Practice?

status: publishe

PILOT STUDY: IMPACT OF 2.4-KG PROXIMAL EXTERNAL LOADING ON 10-KM RUN PERFORMANCE IN RECREATIONALLY COMPETITIVE RUNNERS

Victor A. Alves, Savanna N. Knight, Tate M. Dean, Bandar A. Alghamdi, Brett A. Davis, Lauren G. Killen, Hunter S. Waldman, Eric K. O\u27Neal. University of North Alabama, Florence, AL. BACKGROUND: Recreationally competitive runners typically have higher variability in body fat percentage than elite distance runners. For runners with higher body fat percentages, modest decreases in non-lean mass is achievable and could potentially improve performance. This pilot study examined the performance and metabolic effects of artificially increasing trunk mass with a 2.4 kg, gel-based weighted compression garment. METHODS: Trained runners of various skill level (M = 10, F =6, age = 40 ± 9 years) completed two outdoor 10-km runs on a familiar and challenging course without (CON, first run) and with the weighted compression garment (LOAD, second run). Runners were instructed to finish the CON with a session RPE of ~7 on a 10-point scale. LOAD took place 7-14 days later with a goal to match CON pace (announced every 2.5-km). In a third laboratory session, running economy (RE) was assessed under both conditions at CON pace (1% grade). RESULTS: Runners were able to maintain pace under LOAD (CON = 52.37 ± 6.14, LOAD = 52.86 ± 7.44 min), but experienced an increase in cardiovascular strain for the last half of the run (heart rate ~8 beats/min higher during 5.0-7.5 and 7.5-10-km splits (p \u3c 0.05) and perceptual (session RPE = 71 ± 10 vs 84 ± 10 cm) disadvantages. Similar trends in heart rate and RPE were found during RE trials, but unlike performance, RE was impaired (p = 0.03) by LOAD (13.8 ± 2.9 vs 13.0 ± 2.6 kcal/min). CONCLUSIONS: The high variance from the mixed-sex sample and non-true time trial design may have clouded running performance statistical outcomes, but this data suggests that even modest changes in body mass may influence recreationally trained runners’ competition abilities

The role of physiological traits in assortment among and within fish shoals

Individuals of gregarious species often group with conspecifics to which they are phenotypically similar. This among-group assortment has been studied for body size, sex and relatedness. However, the role of physiological traits has been largely overlooked. Here, we discuss mechanisms by which physiological traits—particularly those related to metabolism and locomotor performance—may result in phenotypic assortment not only among but also within animal groups. At the among-group level, varying combinations of passive assortment, active assortment, phenotypic plasticity and selective mortality may generate phenotypic differences among groups. Even within groups, however, individual variation in energy requirements, aerobic and anaerobic capacity, neurological lateralization and tolerance to environmental stressors are likely to produce differences in the spatial location of individuals or associations between group-mates with specific physiological phenotypes. Owing to the greater availability of empirical research, we focus on groups of fishes (i.e. shoals and schools). Increased knowledge of physiological mechanisms influencing among- and within-group assortment will enhance our understanding of fundamental concepts regarding optimal group size, predator avoidance, group cohesion, information transfer, life-history strategies and the evolutionary effects of group membership. In a broader perspective, predicting animal responses to environmental change will be impossible without a comprehensive understanding of the physiological basis of the formation and functioning of animal social groups. This article is part of the themed issue ‘Physiological determinants of social behaviour in animals’

The effects of acute and chronic hypoxia on cortisol, glucose and lactate concentrations in different populations of three-spined stickleback

The response of individuals from three different populations of three-spined sticklebacks to acute and chronic periods of hypoxia (4.4 kPa DO, 2.2 mg l-1) were tested using measures of whole-body (WB) cortisol, glucose and lactate. Although there was no evidence of a neuroendocrine stress response to acute hypoxia, fish from the population least likely to experience hypoxia in their native habitat had the largest response to low oxygen, with significant evidence of anaerobic glycolysis after two hours of hypoxia. However, there was no measurable effect of a more prolonged period (seven days) of hypoxia on any of the fish in this study, suggesting that they acclimated to this low level of oxygen over time. Between-population differences in the analytes tested were observed in the control fish of the acute hypoxia trial, which had been in the laboratory for 16 days. However, these differences were not apparent among the control fish in the chronic exposure groups that had been held in the laboratory for 23 days suggesting that these site-specific trends in physiological status were acclimatory. Overall, the results of this study suggest that local environmental conditions may shape sticklebacks’ general physiological profile as well as influencing their response to hypoxia