Association between feeding style and weight gain in infants aged 2–7 months

Introduction: Feeding on demand supports an infant’s innate capacity to respond to hunger and satiety cues and may promote later self-regulation of intake. Our aim was to examine whether feeding style (on demand vs to schedule) is associated with weight gain in early life. Methods: Participants were first-time mothers of healthy term infants enrolled NOURISH, an RCT evaluating an intervention to promote positive early feeding practices. Baseline assessment occurred when infants were aged 2-7 months. Infants able to be categorised clearly as feeding on demand or to schedule (mothers self report) were included in the logistic regression analysis. The model was adjusted for gender, breastfeeding and maternal age, education, BMI. Weight gain was defined as a positive difference in baseline minus birthweight z-scores (WHO standards) which indicated tracking above weight percentile. Results: Data from 356 infants with a mean age of 4.4 (SD 1.0) months were available. Of these, 197 (55%) were fed on demand, 42 (12%) were fed on schedule. There was no statistical association between feeding style and weight gain [OR=0.72 (95%CI 0.35-1.46), P=0.36]. Formula fed infants were three times more likely to be fed on schedule and formula feeding was independently associated with increased weight gain [OR=2.02 (95%CI 1.11-3.66), P=0.021]. Conclusion: In this preliminary analysis the association between feeding style and weight gain did not reach statistical significance, however , the effect size may be clinically relevant and future analysis will include the full study sample (N=698).

The association between maternal infant feeding practices and child weight at 11-17 months in first-time Australian mothers

Introduction: Emerging evidence reveals that early feeding practices are associated with child food intake, eating behaviour and weight status. This cross-sectional analysis examined the association between maternal infant feeding practices/beliefs and child weight in Australian infants aged 11-17 months. Methods: Participants were 293 first-time mothers of healthy term infants (144 boys, mean age 14±1 months) enrolled in the NOURISH RCT. Mothers self-reported infant feeding practices and beliefs using the Infant Feeding Questionnaire (Baughcum, 2001). Anthropometric data were also measured at baseline (infants aged 4 months). Multiple regression analysis was used, adjusting for infant age, gender, birth weight, infant feeding mode (breast vs. formula), maternal perceptions of infant weight status, pre-pregnancy weight, weight concern, age and education. Results: The average child weight-for-age z-score (WAZ) was 0.62±0.83 (range:-1.56 to 2.94) and the mean change in WAZ (WAZ change) from 4 to 14 months was 0.62±0.69 (range:-1.50 to 2.76). Feeding practices/beliefs partly explained child WAZ (R2=0.28) and WAZ change (R2=0.13) in the adjusted models. While child weight status at 14 months was inversely associated with responsive feeding (e.g. baby feeds whenever she wants, feeding to stop baby being unsettled) (β=-0.104, p=0.06) and maternal concern about the child becoming underweight (β=-0.224, p<0.001), it was positively associated with mother’s concern about child overweight (β=0.197, p<0.05). Birth weight, infant’s age, maternal weight concern and perceiving her child as overweight were significant covariates. WAZ change was only significantly associated with responsive feeding (β=-0.147, p<0.05). Conclusion: Responsive feeding may be an important strategy to promote healthy child weight.

Associations between parenting behaviours and feeding beliefs of first-time Australian mothers in the NOURISH obesity prevention trial

Purpose: Parenting style and early feeding practices have been linked to child intake, eating behaviour and weight status. The purpose of this study was to examine associations between general maternal parenting behaviours and feeding beliefs in Australian mothers of 11-17 month-old children. Methods: This cross-sectional analysis included 223 first-time mothers and their children (49% male, mean age 14 [sd 1] months) enrolled in the control group of the NOURISH trial. Mothers self-reported their feeding beliefs and parenting behaviours (overprotection, irritability, warmth, autonomy-encouraging) using modified questions from the Infant Feeding Questionnaire (Baughcum, 2001) and the Longitudinal Study of Australian Children. Multiple regression analyses were conducted, using feeding beliefs (four factors) as dependent and parenting behaviours as independent variables while adjusting for child gender, age, weight-for-age z-score and maternal age, education level, feeding mode (breast vs. non-breast), and perception of own pre-pregnancy and child weight status. Results/Findings: Two of four parenting behaviours were significantly associated with feeding beliefs. Maternal warmth was inversely associated with concerns that the child would become underweight (β=-0.156, p=0.022) and positively associated with mothers’ awareness of child’s hunger/satiety cues (β=0.303, p<0.001). Mothers’ overprotection was positively associated with concerns that the child would become underweight (β=0.213, p=0.001); become overweight (β=0.174, p=0.005); and mother’s responsive feeding (β=0.135, p=0.057). Weight-for-age z-score, mothers’ perception of their child and own weight status, education, feeding mode, and child’s age were significant covariates. Conclusions: Feeding occurs within the broader parenting context. Improving early feeding beliefs and practices may require addressing mother’s approaches to parenting, especially warmth and overprotection.

The role of anxiety and perspective-taking strategy on affective empathic responses

Empathy is an important pro-social behaviour critical to a positive clientetherapist relationship. Therapist anxiety has been linked to reduced ability to empathise and lower client satisfaction with therapy. However, the nature of the relationship between anxiety and empathy is currently unclear. The current study investigated the effect of experimentally-induced anxiety on empathic responses elicited during three different perspective-taking tasks. Perspective-taking was manipulated within-subjects with all participants (N¼ 52) completing imagine-self, imagine-other and objective conditions. A threat of shock manipulation was used to vary anxiety between-subjects. Participants in the threat of shock condition reported higher levels of anxiety during the experiment and lower levels of empathyrelated distress for the targets than participants in the control condition. Perspective-taking was associated with higher levels of empathy-related distress and concern compared to the objective condition. The present results suggest that perspective-taking can to a large extent mitigate the influence of heightened anxiety on an individual’s ability to empathise.

Defining the role of phytoene synthase in carotenoid accumulation of high provitamin A bananas

Vitamin A deficiency (VAD) is a serious problem in developing countries, affecting approximately 127 million children of preschool age and 7.2 million pregnant women each year. However, this deficiency is readily treated and prevented through adequate nutrition. This can potentially be achieved through genetically engineered biofortification of staple food crops to enhance provitamin A (pVA) carotenoid content. Bananas are the fourth most important food crop with an annual production of 100 million tonnes and are widely consumed in areas affected by VAD. However, the fruit pVA content of most widely consumed banana cultivars is low (~ 0.2 to 0.5 ìg/g dry weight). This includes cultivars such as the East African highland banana (EAHB), the staple crop in countries such as Uganda, where annual banana consumption is approximately 250 kg per person. This fact, in addition to the agronomic properties of staple banana cultivars such as vegetative reproduction and continuous cropping, make bananas an ideal target for pVA enhancement through genetic engineering. Interestingly, there are banana varieties known with high fruit pVA content (up to 27.8 ìg/g dry weight), although they are not widely consumed due to factors such as cultural preference and availability. The genes involved in carotenoid accumulation during banana fruit ripening have not been well studied and an understanding of the molecular basis for the differential capacity of bananas to accumulate carotenoids may impact on the effective production of genetically engineered high pVA bananas. The production of phytoene by the enzyme phytoene synthase (PSY) has been shown to be an important rate limiting determinant of pVA accumulation in crop systems such as maize and rice. Manipulation of this gene in rice has been used successfully to produce Golden Rice, which exhibits higher seed endosperm pVA levels than wild type plants. Therefore, it was hypothesised that differences between high and low pVA accumulating bananas could be due either to differences in PSY enzyme activity or factors regulating the expression of the psy gene. Therefore, the aim of this thesis was to investigate the role of PSY in accumulation of pVA in banana fruit of representative high (Asupina) and low (Cavendish) pVA banana cultivars by comparing the nucleic acid and encoded amino acid sequences of the banana psy genes, in vivo enzyme activity of PSY in rice callus and expression of PSY through analysis of promoter activity and mRNA levels. Initially, partial sequences of the psy coding region from five banana cultivars were obtained using reverse transcriptase (RT)-PCR with degenerate primers designed to conserved amino acids in the coding region of available psy sequences from other plants. Based on phylogenetic analysis and comparison to maize psy sequences, it was found that in banana, psy occurs as a gene family of at least three members (psy1, psy2a and psy2b). Subsequent analysis of the complete coding regions of these genes from Asupina and Cavendish suggested that they were all capable of producing functional proteins due to high conservation in the catalytic domain. However, inability to obtain the complete mRNA sequences of Cavendish psy2a, and isolation of two non-functional Cavendish psy2a coding region variants, suggested that psy2a expression may be impaired in Cavendish. Sequence analysis indicated that these Cavendish psy2a coding region variants may have resulted from alternate splicing. Evidence of alternate splicing was also observed in one Asupina psy1 coding region variant, which was predicted to produce a functional PSY1 isoform. The complete mRNA sequence of the psy2b coding regions could not be isolated from either cultivar. Interestingly, psy1 was cloned predominantly from leaf while psy2 was obtained preferentially from fruit, suggesting some level of tissue-specific expression. The Asupina and Cavendish psy1 and psy2a coding regions were subsequently expressed in rice callus and the activity of the enzymes compared in vivo through visual observation and quantitative measurement of carotenoid accumulation. The maize B73 psy1 coding region was included as a positive control. After several weeks on selection, regenerating calli showed a range of colours from white to dark orange representing various levels of carotenoid accumulation. These results confirmed that the banana psy coding regions were all capable of producing functional enzymes. No statistically significant differences in levels of activity were observed between banana PSYs, suggesting that differences in PSY activity were not responsible for differences in the fruit pVA content of Asupina and Cavendish. The psy1 and psy2a promoter sequences were isolated from Asupina and Cavendish gDNA using a PCR-based genome walking strategy. Interestingly, three Cavendish psy2a promoter clones of different sizes, representing possible allelic variants, were identified while only single promoter sequences were obtained for the other Asupina and Cavendish psy genes. Bioinformatic analysis of these sequences identified motifs that were previously characterised in the Arabidopsis psy promoter. Notably, an ATCTA motif associated with basal expression in Arabidopsis was identified in all promoters with the exception of two of the Cavendish psy2a promoter clones (Cpsy2apr2 and Cpsy2apr3). G1 and G2 motifs, linked to light-regulated responses in Arabidopsis, appeared to be differentially distributed between psy1 and psy2a promoters. In the untranscribed regulatory regions, the G1 motifs were found only in psy1 promoters, while the G2 motifs were found only in psy2a. Interestingly, both ATCTA and G2 motifs were identified in the 5’ UTRs of Asupina and Cavendish psy1. Consistent with other monocot promoters, introns were present in the Asupina and Cavendish psy1 5’ UTRs, while none were observed in the psy2a 5’ UTRs. Promoters were cloned into expression constructs, driving the â-glucuronidase (GUS) reporter gene. Transient expression of the Asupina and Cavendish psy1 and psy2a promoters in both Cavendish embryogenic cells and Cavendish fruit demonstrated that all promoters were active, except Cpsy2apr2 and Cpsy2apr3. The functional Cavendish psy2a promoter (Cpsy2apr1) appeared to have activity similar to the Asupina psy2a promoter. The activities of the Asupina and Cavendish psy1 promoters were similar to each other, and comparable to those of the functional psy2a promoters. Semi-quantitative PCR analysis of Asupina and Cavendish psy1 and psy2a transcripts showed that psy2a levels were high in green fruit and decreased during ripening, reinforcing the hypothesis that fruit pVA levels were largely dependent on levels of psy2a expression. Additionally, semi-quantitative PCR using intron-spanning primers indicated that high levels of unprocessed psy2a and psy2b mRNA were present in the ripe fruit of Cavendish but not in Asupina. This raised the possibility that differences in intron processing may influence pVA accumulation in Asupina and Cavendish. In this study the role of PSY in banana pVA accumulation was analysed at a number of different levels. Both mRNA accumulation and promoter activity of psy genes studied were very similar between Asupina and Cavendish. However, in several experiments there was evidence of cryptic or alternate splicing that differed in Cavendish compared to Asupina, although these differences were not conclusively linked to the differences in fruit pVA accumulation between Asupina and Cavendish. Therefore, other carotenoid biosynthetic genes or regulatory mechanisms may be involved in determining pVA levels in these cultivars. This study has contributed to an increased understanding of the role of PSY in the production of pVA carotenoids in banana fruit, corroborating the importance of this enzyme in regulating carotenoid production. Ultimately, this work may serve to inform future research into pVA accumulation in important crop varieties such as the EAHB and the discovery of avenues to improve such crops through genetic modification.

Anticipatory innovation

This article examines the role of innovation in society, arguing that a failure of foresight in the practical design and development of innovations has been a significant causal factor in the crisis of global un-sustainability. It questions flawed assumptions about the nature of ecological and social change processes, and the worldview most commonly associated with modernism. In a diagnose, the dimensions of this failure reveal a "disciplinary dissociation", or the failure of disciplines to integrate in order to facilitate a process of innovation with a forward view. Finally the article proposes an alternative approach to innovation which utilises greater foresight, is inclusive of multiple disciplines, and has a greater sensitivity to social and ecological processes. This process is referred to as "anticipatory innovation."

Grading scales for contact lens complications

Purpose. To devise and validate artist-rendered grading scales for contact lens complications Methods. Each of eight tissue complications of contact lens wear (listed under 'Results') was painted by a skilled ophthalmic artist (Terry R. Tarrant) in five grades of severity: 0 (normal), 1 (trace), 2 (mild), 3 (moderate) and 4 (severe). A representative slit lamp photograph of a tissue response of each of the eight complications was shown to 404 contact lens practitioners who had never before used clinical grading scales. The practitioners were asked to grade each tissue response to the nearest 0.1 grade unit by interpolation. Results. The standard deviation (± s.d.) of the 404 responses for each tissue complication is tabulated below:_ing_ 0.5 Endothelial pplymegethisjij-4 0.7 Epithelial microcysts 0.5 Endothelial blebs_ 0.4 Stromal edema_onjunctiva! hyperemia 0.4 Stromal neovascularization 0.4 Papillary conjunctivitis 0.5 The frequency distributions and best-fit normal curves were also plotted. The precision of grading (s.d. x 2) ranged from 0.8 to 1.4, with a mean precision of 1.0. Conclusions. Grading scales afford contact lens practitioners with a method of quantifying the severity of adverse tissue responses to contact lens wear. It is noteworthy that the statistically verified precision of grading (1.0 scale unit) concurs precisely with the essential design feature of the grading scales that each grading step of 1.0 corresponds to clinically significant difference in severity. Thus, as a general rule, a difference or change in grade of > 1.0 can be taken to be both clinically and statistically significant when using these grading scales. Trained observers are likely to achieve even greater grading precision. Supported by Hydron Limited.

Workforce indicators of health literacy

The concept of health literacy has evolved over the last forty years from an individual, literacy driven focus in clinical settings to one associated with a contemporary approach to health promotion. The World Health Organization has defined health literacy as ‘the cognitive and social skills which determine the motivation and ability of individuals to gain access to, understand and use information in ways which promote and maintain good health’ (World Health Organization, 1998, p. 10). The conceptual evolution of health literacy has seen a shift beyond a functional orientation to also recognise cognitive, behavioural and environmental influences. This more comprehensive view of health literacy acknowledges factors like efficacy, motivation, self-efficacy, autonomy, social support and empowerment. A health literate workforce could present benefits for the employee and employer...

Occupational therapy students’ contribution to occasions of service during practice placements in health settings

Currently in the Australian higher education sector, the productivity benefits of occupational therapy clinical education placements are a contested issue. This article will report results of a study that developed a methodology for documenting time use during placements and investigated the productivity changes associated with occupational therapy clinical education placements in Queensland, Australia. Supervisors’ and students’ time use during placements and how this changed for supervisors compared to pre- and post-placement is also presented. Methods: Using a cohort survey design, participants were students from two Queensland universities, and their supervisors employed by Queensland Health. Time use was recorded in 30 minute blocks according to particular categories. Results: There was a significant increase in supervisors’ time spent in patient care activities (F = 94.0112,12.37 df, P < 0.001) between pre- and during placement (P < 0.001) and decrease between during and post-placement (P < 0.001). Supervisors’ time spent in all non-patient care activities was also significant (F = 4.5802,16 df, P = 0.027) increasing between pre- and during placement (P = 0.028). There was a significant decrease in supervisors’ time spent in placement activities (F = 5.1332,19.18 df, P = 0.016) from during to post-placement. Students spent more time than supervisors in patient care activities while on placement. Discussion: A novel method for reporting productivity and time-use changes during clinical education programs for occupational therapy has been applied. Supervisors spent considerable time in assessing and managing students and their clinical education role should be seen as core business in standard occupational therapy practice. This paper will contribute to future assessments of the economic.

The effect of exercise intensity on fat oxidation and non-exercise activity thermogenesis in overweight/obese men

It is frequently reported that the actual weight loss achieved through exercise interventions is less than theoretically expected. Amongst other compensatory adjustments that accompany exercise training (e.g., increases in resting metabolic rate and energy intake), a possible cause of the less than expected weight loss is a failure to produce a marked increase in total daily energy expenditure due to a compensatory reduction in non-exercise activity thermogenesis (NEAT). Therefore, there is a need to understand how behaviour is modified in response to exercise interventions. The proposed benefits of exercise training are numerous, including changes to fat oxidation. Given that a diminished capacity to oxidise fat could be a factor in the aetiology of obesity, an exercise training intensity that optimises fat oxidation in overweight/obese individuals would improve impaired fat oxidation, and potentially reduce health risks that are associated with obesity. To improve our understanding of the effectiveness of exercise for weight management, it is important to ensure exercise intensity is appropriately prescribed, and to identify and monitor potential compensatory behavioural changes consequent to exercise training. In line with the gaps in the literature, three studies were performed. The aim of Study 1 was to determine the effect of acute bouts of moderate- and high-intensity walking exercise on NEAT in overweight and obese men. Sixteen participants performed a single bout of either moderate-intensity walking exercise (MIE) or high-intensity walking exercise (HIE) on two separate occasions. The MIE consisted of walking for 60-min on a motorised treadmill at 6 km.h-1. The 60-min HIE session consisted of walking in 5-min intervals at 6 km.h-1 and 10% grade followed by 5-min at 0% grade. NEAT was assessed by accelerometer three days before, on the day of, and three days after the exercise sessions. There was no significant difference in NEAT vector magnitude (counts.min-1) between the pre-exercise period (days 1-3) and the exercise day (day 4) for either protocol. In addition, there was no change in NEAT during the three days following the MIE session, however NEAT increased by 16% on day 7 (post-exercise) compared with the exercise day (P = 0.32). During the post-exercise period following the HIE session, NEAT was increased by 25% on day 7 compared with the exercise day (P = 0.08), and by 30-33% compared with the pre-exercise period (day 1, day 2 and day 3); P = 0.03, 0.03, 0.02, respectively. To conclude, a single bout of either MIE or HIE did not alter NEAT on the exercise day or on the first two days following the exercise session. However, extending the monitoring of NEAT allowed the detection of a 48 hour delay in increased NEAT after performing HIE. A longer-term intervention is needed to determine the effect of accumulated exercise sessions over a week on NEAT. In Study 2, there were two primary aims. The first aim was to test the reliability of a discontinuous incremental exercise protocol (DISCON-FATmax) to identify the workload at which fat oxidation is maximised (FATmax). Ten overweight and obese sedentary male men (mean BMI of 29.5 ¡Ó 4.5 kg/m2 and mean age of 28.0 ¡Ó 5.3 y) participated in this study and performed two identical DISCON-FATmax tests one week apart. Each test consisted of alternate 4-min exercise and 2-min rest intervals on a cycle ergometer. The starting work load of 28 W was increased every 4-min using 14 W increments followed by 2-min rest intervals. When the respiratory exchange ratio was consistently >1.0, the workload was increased by 14 W every 2-min until volitional exhaustion. Fat oxidation was measured by indirect calorimetry. The mean FATmax, ƒtV O2peak, %ƒtV O2peak and %Wmax at which FATmax occurred during the two tests were 0.23 ¡Ó 0.09 and 0.18 ¡Ó 0.08 (g.min-1); 29.7 ¡Ó 7.8 and 28.3 ¡Ó 7.5 (ml.kg-1.min-1); 42.3 ¡Ó 7.2 and 42.6 ¡Ó 10.2 (%ƒtV O2max) and 36.4 ¡Ó 8.5 and 35.4 ¡Ó 10.9 (%), respectively. A paired-samples T-test revealed a significant difference in FATmax (g.min-1) between the tests (t = 2.65, P = 0.03). The mean difference in FATmax was 0.05 (g.min-1) with the 95% confidence interval ranging from 0.01 to 0.18. Paired-samples T-test, however, revealed no significant difference in the workloads (i.e. W) between the tests, t (9) = 0.70, P = 0.4. The intra-class correlation coefficient for FATmax (g.min-1) between the tests was 0.84 (95% confidence interval: 0.36-0.96, P < 0.01). However, Bland-Altman analysis revealed a large disagreement in FATmax (g.min-1) related to W between the two tests; 11 ¡Ó 14 (W) (4.1 ¡Ó 5.3 ƒtV O2peak (%)).These data demonstrate two important phenomena associated with exercise-induced substrate oxidation; firstly, that maximal fat oxidation derived from a discontinuous FATmax protocol differed statistically between repeated tests, and secondly, there was large variability in the workload corresponding with FATmax. The second aim of Study 2 was to test the validity of a DISCON-FATmax protocol by comparing maximal fat oxidation (g.min-1) determined by DISCON-FATmax with fat oxidation (g.min-1) during a continuous exercise protocol using a constant load (CONEX). Ten overweight and obese sedentary males (BMI = 29.5 ¡Ó 4.5 kg/m2; age = 28.0 ¡Ó 4.5 y) with a ƒtV O2max of 29.1 ¡Ó 7.5 ml.kg-1.min-1 performed a DISCON-FATmax test consisting of alternate 4-min exercise and 2-min rest intervals on a cycle ergometer. The 1-h CONEX protocol used the workload from the DISCON-FATmax to determine FATmax. The mean FATmax, ƒtV O2max, %ƒtV O2max and workload at which FATmax occurred during the DISCON-FATmax were 0.23 ¡Ó 0.09 (g.min-1); 29.1 ¡Ó 7.5 (ml.kg-1.min-1); 43.8 ¡Ó 7.3 (%ƒtV O2max) and 58.8 ¡Ó 19.6 (W), respectively. The mean fat oxidation during the 1-h CONEX protocol was 0.19 ¡Ó 0.07 (g.min-1). A paired-samples T-test revealed no significant difference in fat oxidation (g.min-1) between DISCON-FATmax and CONEX, t (9) = 1.85, P = 0.097 (two-tailed). There was also no significant correlation in fat oxidation between the DISCON-FATmax and CONEX (R=0.51, P = 0.14). Bland- Altman analysis revealed a large disagreement in fat oxidation between the DISCONFATmax and CONEX; the upper limit of agreement was 0.13 (g.min-1) and the lower limit of agreement was ¡V0.03 (g.min-1). These data suggest that the CONEX and DISCONFATmax protocols did not elicit different rates of fat oxidation (g.min-1). However, the individual variability in fat oxidation was large, particularly in the DISCON-FATmax test. Further research is needed to ascertain the validity of graded exercise tests for predicting fat oxidation during constant load exercise sessions. The aim of Study 3 was to compare the impact of two different intensities of four weeks of exercise training on fat oxidation, NEAT, and appetite in overweight and obese men. Using a cross-over design 11 participants (BMI = 29 ¡Ó 4 kg/m2; age = 27 ¡Ó 4 y) participated in a training study and were randomly assigned initially to: [1] a lowintensity (45%ƒtV O2max) exercise (LIT) or [2] a high-intensity interval (alternate 30 s at 90%ƒtV O2max followed by 30 s rest) exercise (HIIT) 40-min duration, three times a week. Participants completed four weeks of supervised training and between cross-over had a two week washout period. At baseline and the end of each exercise intervention,ƒtV O2max, fat oxidation, and NEAT were measured. Fat oxidation was determined during a standard 30-min continuous exercise bout at 45%ƒtV O2max. During the steady state exercise expired gases were measured intermittently for 5-min periods and HR was monitored continuously. In each training period, NEAT was measured for seven consecutive days using an accelerometer (RT3) the week before, at week 3 and the week after training. Subjective appetite sensations and food preferences were measured immediately before and after the first exercise session every week for four weeks during both LIT and HIIT. The mean fat oxidation rate during the standard continuous exercise bout at baseline for both LIT and HIIT was 0.14 ¡Ó 0.08 (g.min-1). After four weeks of exercise training, the mean fat oxidation was 0.178 ¡Ó 0.04 and 0.183 ¡Ó 0.04 g.min-1 for LIT and HIIT, respectively. The mean NEAT (counts.min-1) was 45 ¡Ó 18 at baseline, 55 ¡Ó 22 and 44 ¡Ó 16 during training, and 51 ¡Ó 14 and 50 ¡Ó 21 after training for LIT and HIIT, respectively. There was no significant difference in fat oxidation between LIT and HIIT. Moreover, although not statistically significant, there was some evidence to suggest that LIT and HIIT tend to increase fat oxidation during exercise at 45% ƒtV O2max (P = 0.14 and 0.08, respectively). The order of training treatment did not significantly influence changes in fat oxidation, NEAT, and appetite. NEAT (counts.min-1) was not significantly different in the week following training for either LIT or HIIT. Although not statistically significant (P = 0.08), NEAT was 20% lower during week 3 of exercise training in HIIT compared with LIT. Examination of appetite sensations revealed differences in the intensity of hunger, with higher ratings after LIT compared with HIIT. No differences were found in preferences for high-fat sweet foods between LIT and HIIT. In conclusion, the results of this thesis suggest that while fat oxidation during steady state exercise was not affected by the level of exercise intensity, there is strong evidence to suggest that intense exercise could have a debilitative effect on NEAT.

Risk of Human Papillomavirus-Associated Cancers Among Persons With AIDS

Background Although risk of human papillomavirus (HPV)–associated cancers of the anus, cervix, oropharynx, penis, vagina, and vulva is increased among persons with AIDS, the etiologic role of immunosuppression is unclear and incidence trends for these cancers over time, particularly after the introduction of highly active antiretroviral therapy in 1996, are not well described. Methods Data on 499 230 individuals diagnosed with AIDS from January 1, 1980, through December 31, 2004, were linked with cancer registries in 15 US regions. Risk of in situ and invasive HPV-associated cancers, compared with that in the general population, was measured by use of standardized incidence ratios (SIRs) and 95% confidence intervals (CIs). We evaluated the relationship of immunosuppression with incidence during the period of 4–60 months after AIDS onset by use of CD4 T-cell counts measured at AIDS onset. Incidence during the 4–60 months after AIDS onset was compared across three periods (1980–1989, 1990–1995, and 1996–2004). All statistical tests were two-sided. Results Among persons with AIDS, we observed statistically significantly elevated risk of all HPV-associated in situ (SIRs ranged from 8.9, 95% CI = 8.0 to 9.9, for cervical cancer to 68.6, 95% CI = 59.7 to 78.4, for anal cancer among men) and invasive (SIRs ranged from 1.6, 95% CI = 1.2 to 2.1, for oropharyngeal cancer to 34.6, 95% CI = 30.8 to 38.8, for anal cancer among men) cancers. During 1996–2004, low CD4 T-cell count was associated with statistically significantly increased risk of invasive anal cancer among men (relative risk [RR] per decline of 100 CD4 T cells per cubic millimeter = 1.34, 95% CI = 1.08 to 1.66, P = .006) and non–statistically significantly increased risk of in situ vagina or vulva cancer (RR = 1.52, 95% CI = 0.99 to 2.35, P = .055) and of invasive cervical cancer (RR = 1.32, 95% CI = 0.96 to 1.80, P = .077). Among men, incidence (per 100 000 person-years) of in situ and invasive anal cancer was statistically significantly higher during 1996–2004 than during 1990–1995 (61% increase for in situ cancers, 18.3 cases vs 29.5 cases, respectively; RR = 1.71, 95% CI = 1.24 to 2.35, P < .001; and 104% increase for invasive cancers, 20.7 cases vs 42.3 cases, respectively; RR = 2.03, 95% CI = 1.54 to 2.68, P < .001). Incidence of other cancers was stable over time. Conclusions Risk of HPV-associated cancers was elevated among persons with AIDS and increased with increasing immunosuppression. The increasing incidence for anal cancer during 1996–2004 indicates that prolonged survival may be associated with increased risk of certain HPV-associated cancers.

Effects of cold water immersion on knee joint position sense in healthy volunteers

The purpose of this study was to determine the effects of cryotherapy, in the form of cold water immersion, on knee joint position sense. Fourteen healthy volunteers, with no previous knee injury or pre-existing clinical condition, participated in this randomized cross-over trial. The intervention consisted of a 30-min immersion, to the level of the umbilicus, in either cold (14 ± 1°C) or tepid water(28 ± 1°C). Approximately one week later, in a randomized fashion, the volunteers completed the remaining immersion. Active ipsilateral limb repositioning sense of the right knee was measured, using weight-bearing and non-weight bearing assessments, employing video-recorded 3D motion analysis. These assessments were conducted immediately before and after a cold and tepid water immersion. No significant differences were found between treatments for the absolute (P = 0.29), relative (P = 0.21) or variable error (P = 0.86). The average effect size of the outcome measures was modest (range –0.49 to 0.9) and all the associated 95% confidence intervals for these effect sizes crossed zero. These results indicate that there is no evidence of an enhanced risk of injury, following a return to sporting activity, after cold water.

Cryotherapy and joint position sense in healthy participants: a systematic review

Objective: To (1) search the English-language literature for original research addressing the effect of cryotherapy on joint position sense (JPS) and (2) make recommendations regarding how soon healthy athletes can safely return to participation after cryotherapy. Data Sources: We performed an exhaustive search for original research using the AMED, CINAHL, MEDLINE, and SportDiscus databases from 1973 to 2009 to gather information on cryotherapy and JPS. Key words used were cryotherapy and proprioception, cryotherapy and joint position sense, cryotherapy, and proprioception. Study Selection: The inclusion criteria were (1) the literature was written in English, (2) participants were human, (3) an outcome measure included JPS, (4) participants were healthy, and (5) participants were tested immediately after a cryotherapy application to a joint. Data Extraction: The means and SDs of the JPS outcome measures were extracted and used to estimate the effect size (Cohen d) and associated 95% confidence intervals for comparisons of JPS before and after a cryotherapy treatment. The numbers, ages, and sexes of participants in all 7 selected studies were also extracted. Data Synthesis: The JPS was assessed in 3 joints: ankle (n 5 2), knee (n 5 3), and shoulder (n 5 2). The average effect size for the 7 included studies was modest, with effect sizes ranging from 20.08 to 1.17, with a positive number representing an increase in JPS error. The average methodologic score of the included studies was 5.4/10 (range, 5–6) on the Physiotherapy Evidence Database scale. Conclusions: Limited and equivocal evidence is available to address the effect of cryotherapy on proprioception in the form of JPS. Until further evidence is provided, clinicians should be cautious when returning individuals to tasks requiring components of proprioceptive input immediately after a cryotherapy treatment.

Cytokine secretion via cholesterol-rich lipid raft-associated SNAREs at the phagocytic cup

Lipopolysaccharide-activated macrophages rapidly synthesize and secrete tumor necrosis factor α (TNFα) to prime the immune system. Surface delivery of membrane carrying newly synthesized TNFα is controlled and limited by the level of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins syntaxin 4 and SNAP-23. Many functions in immune cells are coordinated from lipid rafts in the plasmamembrane, and we investigated a possible role for lipid rafts in TNFα trafficking and secretion. TNFα surface delivery and secretion were found to be cholesterol- dependent. Upon macrophage activation, syntaxin 4 was recruited to cholesterol-dependent lipid rafts, whereas its regulatory protein, Munc18c, was excluded from the rafts. Syntaxin 4 in activated macrophages localized to discrete cholesterol-dependent puncta on the plasmamembrane, particularly on filopodia. Imaging the early stages of TNFα surface distribution revealed these puncta to be the initial points of TNFα delivery. During the early stages of phagocytosis, syntaxin 4 was recruited to the phagocytic cup in a cholesterol dependent manner. Insertion of VAMP3-positive recycling endosome membrane is required for efficient ingestion of a pathogen. Without this recruitment of syntaxin 4, it is not incorporated into the plasma membrane, and phagocytosis is greatly reduced. Thus, relocation of syntaxin 4 into lipid rafts in macrophages is a critical and rate-limiting step in initiating an effective immune response.

Catalytic properties of 26 S and 20 S proteasomes and radiolabeling of MB1, LMP7, and C7 subunits associated with trypsin-like and chymotrypsin-like activities*

20 and 26 S proteasomes were isolated from rat liver. The procedure developed for the 26 S proteasome resulted in greatly improved yields compared with previously published methods. A comparison of the kinetic properties of 20 and 26 S proteasomes showed significant differences in the kinetic characteristics with certain substrates and differences in the effects of a protein substrate on peptidase activity. Observed differences in the kinetics of peptidylglutamyl peptide hydrolase activity suggest that the 26 S complex cannot undergo the conformational changes of 20 S proteasomes at high concentrations of the substrate benzyloxycarbonyl (Z) -Leu-Leu-Glu-b-naphthylamide. Various inhibitors that differentially affect the trypsin-like and chymotrypsin-like activities have been identified. Ala-Ala-Phe-chloromethyl (CH2Cl) inhibits chymotrypsin-like activity assayed with succinyl (Suc) -Leu-Leu-Val-Tyr-AMC, but surprisingly not hydrolysis of Ala-Ala-Phe-7-amido-4-methylcoumarin (AMC). Tyr-Gly-Arg-CH2Cl inhibits Suc-Leu-Leu-Val-Tyr-AMC hydrolysis as well as trypsinlike activity measured with t-butoxycarbonyl (Boc) -Leu-Ser-Thr-Arg-AMC, while Z-Phe-Gly-Tyr-diazomethyl (CHN2) was found to inhibit only the two chymotrypsin- like activities. Radiolabeled forms of peptidyl chloromethane and peptidyl diazomethane inhibitors, [3H]acetyl-Ala-Ala-Phe-CH2Cl, [3H]acetyland radioiodinated Tyr-Gly-Arg-CH2Cl, and Z-Phe-Gly- Tyr-(125I-CHN2), have been used to identify catalytic components associated with each of the three peptidase activities. In each case, incorporation of the label could be blocked by prior treatment of the proteasomes with known active site-directed inhibitors, calpain inhibitor 1 or 3,4-dichloroisocoumarin. Subunits of labeled proteasomes were separated either by reverse phase-HPLC and SDS-polyacrylamide gel electrophoresis or by twodimensional polyacrylamide gel electrophoresis followed by autoradiography/fluorography and immunoblotting with subunit-specific antibodies. In each case, label was found to be incorporated into subunits C7, MB1, and LMP7 but in different relative amounts depending on the inhibitor used, consistent with the observed effects on the different peptidase activities. The results strongly suggest a relationship between trypsin-like activity and chymotrypsin-like activity. They also help to relate the different subunits of the complex to the assayed multicatalytic endopeptidase activities