The physiology of growth hormone (GH) in adults: translational journey to GH replacement therapy

The fact that growth hormone (GH) plays an important role in health after the cessation of growth requiring replacement therapy in adult life has only been recognised in the last three decades. This has only been made possible by recombinant technology providing GH supplies required to undertake investigations in the physiology of GH action and the benefits of replacement therapy in patients identified by rigorously validated diagnostic tests for GH deficiency (GHD). Human studies have revealed important regulatory roles in substrate metabolism, sodium homeostasis, body composition, and physical function. GH-induced anabolism is achieved by stimulating amino acid incorporation into protein while reducing oxidative loss simultaneously enhancing lipid utilisation by stimulating fatty acid oxidation and reducing lipid storage. Sodium and fluid retention are enhanced by activating the renin-angiotensin system and distal renal tubular reabsorption. GH stimulates the aerobic and anaerobic energy systems that underpin muscle and cardiovascular function. These pleiotropic actions explain the clinical picture of increased adiposity, reduced lean mass, and impaired physical and psychological function in the GHD adult, all of which are reversed when GH is replaced. Women require a greater replacement dose of GH than men. This is because androgens enhance while oestrogens attenuate GH action. The oestrogen effect is route-dependent, occurring with oral delivery blunting the liver-mediated actions of GH by directly inhibiting GH receptor signalling, global experience spanning over 30 years has attested to the safety, efficacy, and benefits of replacement therapy for adults with GHD

Epidemiology of SARS in the 2003 Hong Kong epidemic.

1. The temporal and spatial evolution of the SARS epidemic in Hong Kong is described. 2. Estimates of key epidemiological distributions and their stability over the course of the epidemic are derived. 3. The characteristics of those who contracted the disease are determined including factors associated with the likelihood of mortality as a result of SARS coronavirus infection.published_or_final_versio

The cost of tobacco-related disease

Health Services Research Fund & Health Care and Promotion Fund: Research Dissemination Reports (Series 2)published_or_final_versio

Driving RVpark/Campground Selection: A Grounded Theory Approach

The ability to “provide almost unrestricted land travel” (Prideaux & Carson, 2003, p. 307) has made drive tourism popular for tourists. A considerable sub-sector of the drive tourism industry is that of the multi-billion-dollar recreational vehicle industry (RV). Minimal academic research has been conducted on this important sub-sector of the drive tourism industry. This study builds upon previous research towards a further understanding of the RV consumer. A grounded theory approach was used to drive the direction of the research for this study. Given the scope of the data and studies that have been done regarding RV industry, this study examines the extent that motivational factors vary amongst three distinct segments of travelers within the RV industry. This study adds to the academic body of knowledge through the expansion of motivational research into the RV industry while also exploring spending patterns and importance of various sources of information amongst consumers. The research will give the industry a deeper understanding of the needs of the varying target markets so they can better tailor the offerings to meet consumer demands

Prevalence of SARS-CoV antibody in all Hong Kong patient contacts.

The near absence of transmission (seroprevalence=0.19%) resulting in asymptomatic infection in this representative high-risk group of close contacts indicates that the prevailing SARS-CoV strains in Hong Kong almost always led to clinically apparent disease.published_or_final_versio

Regression Towards the Mean Artifacts and Matthew Effects in multilevel analyses of value-added of individual schools

League tables are a problematic approach to inferring school effectiveness, but traditional value-added approaches are fraught with statistical complexities. According to the Regression Towards the Mean Artifacts (RTMA), students with initially high or low scores tend to regress towards the mean in subsequent testing, resulting in biased estimates of school growth (Marsh & Hau, 2002). The Matthews Effect is an apparently counter-balancing artifact in growth in achievement gains is systematically larger for students who are initially more able. (i.e., the rich becomes richer). Mathematical proof shows that although the Matthew and the RTMA artifacts work in opposite direction and tend to cancel each other, they share a similar mechanism and can be rectified. In this study, mathematical derivations and Monte Carlo simulated data are used to compare four models, namely: (i) without any remedy, (ii) with remedy for Matthew effect only, (iii) with remedy for RTMA only, (iv) remedies for both Matthew and RTMA effects. The conditional strategy with individual assignment test scores (used in assigning students to different schools) as covariate remedies artifacts, consistent with Marsh & Hau's (2002) conclusion for RTMA. The associated problems with the two effects in estimating school value-added information are discussed.published_or_final_versio

Methods for estimating the case fatality ratio for a novel, emerging infectious disease.

During the course of an epidemic of a potentially fatal disease, it is important that the case fatality ratio be well estimated. The authors propose a novel method for doing so based on the Kaplan-Meier survival procedure, jointly considering two outcomes (death and recovery), and evaluate its performance by using data from the 2003 epidemic of severe acute respiratory syndrome in Hong Kong, People's Republic of China. They compare this estimate obtained at various points in the epidemic with the case fatality ratio eventually observed; with two commonly quoted, naïve estimates derived from cumulative incidence and mortality statistics at single time points; and with estimates in which a parametric mixture model is used. They demonstrate the importance of patient characteristics regarding outcome by analyzing subgroups defined by age at admission to the hospital

Turnip mosaic potyvirus probably first spread to Eurasian brassica crops from wild orchids about 1000 years ago

Turnip mosaic potyvirus (TuMV) is probably the most widespread and damaging virus that infects cultivated brassicas worldwide. Previous work has indicated that the virus originated in western Eurasia, with all of its closest relatives being viruses of monocotyledonous plants. Here we report that we have identified a sister lineage of TuMV-like potyviruses (TuMV-OM) from European orchids. The isolates of TuMV-OM form a monophyletic sister lineage to the brassica-infecting TuMVs (TuMV-BIs), and are nested within a clade of monocotyledon-infecting viruses. Extensive host-range tests showed that all of the TuMV-OMs are biologically similar to, but distinct from, TuMV-BIs and do not readily infect brassicas. We conclude that it is more likely that TuMV evolved from a TuMV-OM-like ancestor than the reverse. We did Bayesian coalescent analyses using a combination of novel and published sequence data from four TuMV genes [helper component-proteinase protein (HC-Pro), protein 3(P3), nuclear inclusion b protein (NIb), and coat protein (CP)]. Three genes (HC-Pro, P3, and NIb), but not the CP gene, gave results indicating that the TuMV-BI viruses diverged from TuMV-OMs around 1000 years ago. Only 150 years later, the four lineages of the present global population of TuMV-BIs diverged from one another. These dates are congruent with historical records of the spread of agriculture in Western Europe. From about 1200 years ago, there was a warming of the climate, and agriculture and the human population of the region greatly increased. Farming replaced woodlands, fostering viruses and aphid vectors that could invade the crops, which included several brassica cultivars and weeds. Later, starting 500 years ago, inter-continental maritime trade probably spread the TuMV-BIs to the remainder of the world

Longitudinal assessment of community psychobehavioral responses during and after the 2003 outbreak of severe acute respiratory syndrome in Hong Kong

Background. In previous literature, the stability and temporal evolution of psychobehavioral responses to an outbreak remained undefined, because of the exclusively cross-sectional nature of such study designs. Methods. Using random-digit dialing, we sampled 4481 Hong Kong residents in 6 population-based surveys that were conducted at different times during and after the 2003 outbreak of severe acute respiratory syndrome (SARS). Results. Respondents' State-Trait Anxiety Inventory score (range, 10-40) showed a decreasing temporal trend, from a high mean value of 24.8 during the peak of the Amoy Gardens outbreak to a postepidemic mean baseline value of 14.5. Those who perceived a higher likelihood of contracting or dying of SARS had significantly higher anxiety scores. Female respondents, individuals aged 30-49 years, and individuals with only a primary education or less were predisposed to greater anxiety. There was a positive dose-response gradient between anxiety level and uptake of personal protective measures. Males respondents, individuals at the extremes of age, and individuals with lower educational levels were less likely to engage in self-protective behavior. The presence of symptoms was the only consistent predictor for greater use of health services. There was remarkable stability in the magnitude and the direction of associations between predictors and outcomes over time. Conclusions. Our findings can assist in modifying public service announcements in the future, which should be tailored to psychobehavioral surveillance intelligence to achieve the desired behavioral outcomes. Future research should explore the use of more-sophisticated techniques, including structural equation modeling and game-theoretical frameworks, to analyze population psychology and behavior, and it should integrate such findings with transmission dynamics modeling. © 2005 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio