Australian Science

Category: Health

  • An outdated appetite control system in a rapidly evolving world?

    An outdated appetite control system in a rapidly evolving world?

    Imagine yourself for a moment waiting for a meal at your favourite restaurant, local takeaway store or at home counting down the time until the oven buzzer sounds. You know you’re hungry, but we seldom think or care about the complex series of processes that go on inside our bodies that drive that hunger.

    And why should we care?

    In the developed world, for the lucky majority at least, calorie-dense food has never been more accessible. Want a pizza? Just use an app from your smartphone to order one delivered any time, day or night. The one big problem with this–human appetite has evolved over tens of thousands of years when food was tough to come by, and we had to work physically hard for a meal, now we just go to the fridge. However the series of long developed processes that drive appetite have not caught up in this time of plenty thereby contributing to the modern day upsurge in obesity.

    Obesity as a global problem

    Obesity is a global disease on the increase, the World Health Organisation estimates that by 2015 there will be an astounding 700 million adults classified as obese. From a health viewpoint this is particularly worrying as obesity is a major risk factor for cardiovascular diseases, Type-2 diabetes and some cancers.

    Also concerning, is the number of people in developing countries at risk, where the bane of obesity joins established under-nutrition. Dr Ranjan Yajnik, the director of the diabetes unit at King Edward Memorial Hospital in Pune, was recently reported by ABC News saying, “Populations which have faced under-nutrition for a long time are now exposed to the over-nutrition of the modern world through globalisation and westernisation”.

    In short, it’s the modern world and how we live in it which is driving up rates of obesity.

    An unbalanced system?

    In broad terms, the body is wired to protect against starvation and low food availability, by increasing biological and sensory processes that promote the need to eat. This makes sense, after all starvation is an immediate threat to survival and was by far one of the greatest concerns of our ancient ancestors. As excessive food was less of a concern, the regulatory processes to protect against excess consumption and weight gain appear less effective, leading to the body favouring weight gain over weight loss.
    Combine this with the increased availability of highly palatable foods, and the ability to stop eating when full is increasingly difficult. According to Dr. Joanne Harrold and colleagues, in a recent paper published in the journal Neoropharmacology, this may be especially true for many obese people, who may “possess an over-responsiveness to the reward effects of eating, which results in the appetite system of these people being effectively overwhelmed

  • America in the time of AIDS

    America in the time of AIDS

    This week the world descends on Washington DC, to discuss, evaluate, and get the state of the art of what is probably the disease of our times: HIV/AIDS; as the city prepares to host the International AIDS Conference (AIDS2012). It marks the first time in 20 years the conference has been held in the US — coming as the US lifts the ban on people entering the country with an HIV positive status.

    It is the cliché to think that sub-Saharan Africa, particularly southern Africa, typifies and exemplifies the problem we have and our struggle with HIV/AIDS. America hides an ugly truth about a disease that last year celebrated its 30th birthday (anniversary of the first case reports in the United States). Washington DC has an HIV infection rate of 3.2%. If it were a country it would rank 23rd out of 54 in percentage of people with HIV — placing it above the Democratic Republic of Congo, Ghana, and 30 other African countries, and just behind Nigeria.

    In 1995, the number of new cases in black Americans overtook the number of new cases in white Americans and other ethnicities — and it’s been that way ever since. The District of Columbia, with a population of 600,000 odd inhabitants, has a rate of prevalence of HIV/AIDS among black males that far outweighs other ethnic groups, and even the total prevalence in other American cities.

    With the number of cases around the world dropping, in general, in the US it has remained the same. If the problem in southern Africa is one of denialism… America’s problem is one of inequality. From the statistics you would be forgiven to think that poverty equals AIDS. Poverty does not equal AIDS. Inequality equals AIDS.

    The problem seems systemic, being placed squarely on the shoulders of a city that has failed its population. The Globalpost writes “for years, the District had failed to do in-depth surveillance of the AIDS epidemic and had perceived it to a problem largely limited to the gay community and injectable drug users

  • Plastics Make it… Problematic

    Plastics Make it… Problematic

    The American Chemistry Council sponsors an initiative “Plastics Make it Possible.

  • BioGrid Australia links data to show bowel cancer screening is making impact on patient survival rate

    BioGrid Australia links data to show bowel cancer screening is making impact on patient survival rate

    BioGrid Australia links data to show bowel cancer screening is making impact on patient survival rate.

    Victorian researchers have been able to confirm that the national bowel cancer screening program is making a major impact on patient survival.

    Using data made available through BioGrid Australia, the researchers have shown that patients diagnosed as a result of a positive screening test have a much higher survival rate than patients presenting with symptoms.

    Maureen Turner, CEO of BioGrid Australia, said today that recent analysis from six Victorian hospitals has shown an increased number of early stage cancers diagnosed via the bowel screening programs (43% versus 19%) and a reduced number of patients with advanced cancer (4% versus 18%),² she said.

    This research is further confirmation of the value of the national bowel cancer screening program and the valuable contribution that BioGrid Australia, an innovative medical research platform, is making to furthering our understanding of cancers and other diseases,² she said.

    Dr Peter Gibbs and colleagues analysed diagnosis and survival information for 103 patients (all of whom had no symptoms of cancer) diagnosed as the result of a positive stool screening test on the national program.

    The patients attended six hospitals in Melbourne: Royal Melbourne, Royal Melbourne Private, Western Hospital, Western Private, Box Hill and Epworth Eastern. These patients were diagnosed between May 2006 and 2012 and their results were compared to 793 patients of the same age presenting with symptoms over the same timeframe.

    ³This analysis confirms that patients with a bowel cancer detected by a screening test, long before any symptoms have appeared, have a much improved outcome, with a projected five year survival of 95% compared to 73% for patients of the same age who were diagnosed with symptoms² said Dr Gibbs.

    ³This research yet again emphasises the ongoing need for and value of Australia¹s national bowel screening program which is leading to better survival rates as a direct result of earlier diagnosis.² Data available through BioGrid Australia was previously used in a campaign to extend the Australian National Bowel Cancer Screening Program to 60 and 70 year olds, by demonstrating the potential savings of early bowel cancer diagnosis.

    The research released in 2010 showed that annual bowel cancer treatment costs was likely to increase four-fold to $1 billion over 10 years by 2011, strengthening the economic case for expanding the Government¹s National Bowel Cancer Screening Program. The study by Victorian researchers supported by BioGrid Australia combined Australian screening data with treatment costs and survival rates, providing new evidence of the program¹s economic and social benefits. The researchers determined the cost of treating any one patient with bowel cancer at about $55,000 a patient.

    Due to the cost of expensive new therapies treating stage 3 (more advanced) cancers tripled from $25,000 in 1999 to $75,000 and for stage 4 (most advanced), the cost has significantly escalated 10 fold from $6,000 to $61,000. By screening leading to the detection of early stage cancers which can be dealt with by surgery alone, the substantial cost of treating later stage cancers, including the use of expensive chemotherapy drugs, are avoided. The data available through BioGrid was able to show the cost effectiveness of screening.

    The free National Bowel Cancer Screening Program was introduced in 2006. In the 2012 ­ 2013 Federal Budget, the program was expanded to include Australians turning 60 years of age from 2013 and those turning 70 years of age from 2015.

    The expansion of the screening program means that an estimated 1,000 early cancers will be detected each year and between 300 and 500 lives saved annually. This will significantly reduce the burden of bowel cancer on Australians and their families. Bowel cancer is the second most commonly diagnosed cancer in Australia, with annually more than 13,000 cases and 4,100 deaths from this disease.

    BioGrid Australia

    BioGrid Australia (www.biogrid.org.au) is an innovative medical research platform that facilitates privacy-protected research across many hospitals and medical research institutes. BioGrid provides an online Access Request System by which researchers can apply for access to specific databases.  Through this system, the data custodians approve access to their data and a Scientific Expert Review Committee assesses the proposed investigation providing formal ethics approval. Once authorised, researchers can access de-identified data for specified research.

    Issued on behalf of BioGrid Australia.

    Image source.

  • How Much is that Green Algae in the Window?

    How Much is that Green Algae in the Window?

    Whoever thought you could make money in biology, right? Turns out, there is quite a bit of money to be made in this field. And I think we are realizing more than ever the importance of the life sciences and the contribution it offers to society and the economy.

    “I think the biggest innovations of the 21st Century will be the intersection of biology and technology. A new era is beginning, just like the digital one was when I was his age.

  • The Olympics Mass Effect

    The Olympics Mass Effect

    59 Days to go.

    Simply put, for those that care about the London Olympics — the excitement is mounting. With 26 sports across 44 venues, 10,500 athletes and millions of spectators, it’s going to be a busy summer. From Box-hill to Coventry, and all across London the preparations are almost over and it’s almost time for the curtains to go up. Behind the scenes  a workforce of around 200,000 people are being amassed — comprising of around 6,000 paid full-time and temporary employees, up to 70,000 volunteers and around 100,000 contractors. A small army. Add to this another small army of reporters and media that will cover the games from every angle. The American broadcaster NBC will be sending a team of around 2,800 to London. The BBC will deliver a record 2,500 hours of live action from the games, including 26 channels dedicated to each sport. An Olympic staff (in more ways than one) that actually outnumbers Team GB itself by a considerable margin.

    As Londoners, nonplussed about it all, make a quiet exit for a few weeks, the city and those unlucky enough to be caught in it, are going to be overrun with tourists, sightseers, and everyone else.

    The amount of column inches dedicated to the Olympics, as you would expect, is significant. From the tried-and-tested stories of athletes battling against the odds to make it to London this summer. To the truly bizarre ones of the UK’s Ministry of Defence telling residents high-velocity rockets will be fitted to apartment blocks close to the Olympic Park. With round the clock surveillance, and even snipers.

    Evidently, in the run-up to the games, tensions and expectations for worse-case-scenarios are high. The threat and danger of anything sparking a problem is clearly in the forefront of the organiser’s minds. With millions of extra people added to the melting pot it’s not just an extra strain on public services. It goes beyond that — the Olympics should come with a health warning.

    Well, in fact, it does. A doctor at the Centers for Disease Control and Prevention (CDC) has told US travellers to make sure they are vaccinated against measles if they travel to London for the Olympics in July.

    “Disease knows no borders. We are concerned about Americans coming back from the Olympics this summer and unknowingly infecting others,

  • Battlefield Theory

    Battlefield Theory

    Imagine the scene — from the mouth and nose, through the pharynx into the trachea, separating into the left and right main bronchi at the larynx. This is the start of your airway. This is to be the site of inflammation, or rather, the site of battle. Across the landscape that is the airways, two sides are about to go to war. Invading pathogens versus human inflammatory cells. This war will eventually lead to pneumonia.

    To treat pneumonia we need to pin down the exact invading pathogen and treat accordingly. The most common types of infectious agents are viruses and bacteria. But of all the microorganisms that can cause pneumonia, most cases are down to only about two dozen species. Identifying the infecting agent, the actual cause of pneumonia, relies on a lengthy process; from a full patient history and examination, to imaging studies and epidemiological information, together with bacteriological tests.

    Despite all of this, in up to 50% cases of pneumonia, the causative pathogen remain unidentified.

    In and amongst the invading pathogens are other organisms that are just bystanders — colonizing the airway. Other commensal organisms in and amongst our instigators of war. In diagnosing pneumonia many are implicated and detecting these organisms in the airway does not necessarily mean they are the cause of infection. As such, any commensal organism that falls within a certain spread of criteria is thought to be the causative agent.

    The key to all of this is the difference between colonization and infection.

    To discriminate between the two types of organisms in a pneumonia infection — infectious and colonizing —  researchers from Japan came up with the “pneumonia battlefield“. The titled “Battlefield Hypothesis

  • Social and physical influences of sports and exercise

    Social and physical influences of sports and exercise

    training
    Image source: www.ontrackretreats.com.au

    Since the beginning of time sport has had a great importance. It is good for health and fitness, it is great fun and pastime and is great for learning how to win and dealing with the loss. Many factors influence sports activities and the study of them has gone to such an extent that today there is even a branch of sociology studying sports.

    Sport is all forms of physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Sport may be competitive, where a winner or winners can be identified by objective means, and may require a degree of skill, especially at higher levels. Hundreds of sports exist, including those for a single participant, through to those with hundreds of simultaneous participants, either in teams or competing as individuals. Some non-physical activities, such as board games and card games are sometimes referred to as sports, but a sport is generally recognised as being based in physical athleticism. [1]

    Promoting physical activity is a public health priority, and changes in the environmental contexts of adults’ activity choices are believed to be crucial. However, of the factors associated with physical activity, environmental influences are among the least understood.
    Method: Using journal scans and computerized literature database searches, we identified 19 quantitative studies that assessed the relationships with physical activity behavior of perceived and objectively determined physical environment attributes. Findings were categorized into those examining five categories: accessibility of facilities, opportunities for activity, weather, safety, and aesthetic attributes.
    Results: Accessibility, opportunities, and aesthetic attributes had significant associations with physical activity. Weather and safety showed less-strong relationships. Where studies pooled different categories to create composite variables, the associations were less likely to be statistically significant.
    Conclusions: Physical environment factors have consistent associations with physical activity behavior. Further development of ecologic and environmental models, together with behavior-specific and context-specific measurement strategies, should help in further understanding of these associations. Prospective studies are required to identify possible causal relationships. [2]

    bicycles
    Image source: www.reidcycles.com.au

    Results of the studies continue to support a growing literature suggesting that exercise, physical activity and physical-activity interventions have beneficial effects across several physical and mental-health outcomes. Generally, participants engaging in regular physical activity display more desirable health outcomes across a variety of physical conditions. Similarly, participants in randomized clinical trials of physical-activity interventions show better health outcomes, including better general and health-related quality of life, better functional capacity and better mood states.
    The studies have several implications for clinical practice and research. Most work suggests that exercise and physical activity are associated with better quality of life and health outcomes. Therefore, assessment and promotion of exercise and physical activity may be beneficial in achieving desired benefits across several populations. Several limitations were noted, particularly in research involving randomized clinical trials. These trials tend to involve limited sample sizes with short follow-up periods, thus limiting the clinical implications of the benefits associated with physical activity. [3]

    Little is known about possible determinants of children’s participation in physical activity. In particular, the role of adults has not been clearly identified. This study investigated contemporary social cognitive variables, in combination with likely adult influence factors, in predicting intended and self reported vigorous physical activity for young adolescents. A questionnaire was administered to 147 boys and girls ages 13–14. Questions assessed physical activity levels, including vigorous activity, intention to take part in sports or vigorous physical activity, social cognitive variables, and adult encouragement of physical activity. A structural equation modeling analysis showed a good fit for a model in which vigorous physical activity was predicted by direct paths from adult encouragement and intention, with adult encouragement also predicting vigorous activity indirectly through perceived competence. Intention itself was predicted by adult encouragement and a task achievement goal orientation. [4]

    Mental disorders are of major public health significance. It has been claimed that vigorous physical activity has positive effects on mental health in both clinical and nonclinical populations. This paper reviews the evidence for this claim and provides recommendations for future studies. The strongest evidence suggests that physical activity and exercise probably alleviate some symptoms associated with mild to moderate depression. The evidence also suggests that physical activity and exercise might provide a beneficial adjunct for alcoholism and substance abuse programs; improve self-image, social skills, and cognitive functioning; reduce the symptoms of anxiety; and alter aspects of coronary-prone (Type A) behavior and physiological response to stresses. The effects of physical activity and exercise on mental disorders, such as schizophrenia, and other aspects of mental health are not known. Negative psychological effects from exercise have also been reported. Recommendations for further research on the effects of physical activity and exercise on mental health are made.[5]

    Conclusion:

    The significance of sport is great. Not only that it effects our physical well-being but our state of mind as well. Various things effect how we experience sports activities however their benefits mustn’t be forgotten and neglected.

    References:

    [1] http://en.wikipedia.org/wiki/Sport
    [2] ‘Environmental factors associated with adults’ participation in physical activity’ by Nancy Humpel BPsyc, Neville Owen PhD and Eva Leslie MHN
    [3] ‘Exercise and well-being: a review of mental and physical health benefits associated with physical activity’ by Penedo, Frank Ja; Dahn, Jason Ra,b
    [4] J Sch Health. 1996;66(2):75–78
    [5] ‘The relation of physical activity and exercise to mental health’ by C B Taylor, J F Sallis, and R Needle

  • Impact of wireless networks on human health

    Impact of wireless networks on human health

    In the modern days wireless technology has become indispensible and is a part of our every-day lives. We have it with remote controls, video cameras, baby monitors and of course mobile phones and wireless internet connections. Despite all its benefits many are concerned about its influence on our health.

    Basics:

    Wireless computer networks have become commonplace in our environment. Wireless hotspots are found in many public areas and, increasingly, in homes and schools. Wireless networks use low-powered radiofrequency (RF) transmitters called access points to communicate with other low-powered transmitters called client cards that are located in users’ laptop computers or other portable equipment. Nearly all of these wireless networks use Wi-Fi technology, although other wireless technologies are coming into use as well.[1]
    Mobile telephony is now commonplace around the world. This wireless technology relies upon an extensive network of fixed antennas, or base stations, relaying information with radiofrequency (RF) signals. Over 1.4 million base stations exist worldwide and the number is increasing significantly with the introduction of third generation technology.

    ipad
    Image source: www.macfixit.com.au

    There has been concern about possible health consequences from exposure to the RF fields produced by wireless technologies. This fact sheet reviews the scientific evidence on the health effects from continuous low-level human exposure to base stations and other local wireless networks.

    Health concerns

    To date, the only health effect from RF fields identified in scientific reviews has been related to an increase in body temperature (> 1 °C) from exposure at very high field intensity found only in certain industrial facilities, such as RF heaters. The levels of RF exposure from base stations and wireless networks are so low that the temperature increases are insignificant and do not affect human health.
    In fact, due to their lower frequency, at similar RF exposure levels, the body absorbs up to five times more of the signal from FM radio and television than from base stations.

    Cancer:

    Scientific evidence on the distribution of cancer in the population can be obtained through carefully planned and executed epidemiological studies. Over the past 15 years, studies examining a potential relationship between RF transmitters and cancer have been published. These studies have not provided evidence that RF exposure from the transmitters increases the risk of cancer.
    Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects.[2]
    Also, the results, which are detailed in the Health Physics paper, show that in all cases the measured Wi-Fi signal levels were very far below international safety limits, specifically, those of the Institute of Electrical and Electronics Engineers and the International Commission on Nonionizing Radiation Protection (ICNIRP 2002). These limits were designed to protect against all known hazards of RF energy. [3]
    The World Health Organization has acknowledged that electromagnetic fields (EMFs) are influencing the environment (but not people), and that some people are worried about possible effects. In response to public concern, the World Health Organization established the International EMF Project in 1996 to assess the scientific evidence of possible health effects of EMF in the frequency range from 0 to 300 GHz. They have stated that although extensive research has been conducted into possible health effects of exposure to many parts of the frequency spectrum, all reviews conducted so far have indicated that exposures are below the limits recommended in the ICNIRP (1998) EMF guidelines, covering the full frequency range from 0–300 GHz, and do not produce any known adverse health effect.[4]

    Conclusion:

    After conducting numerous researches on the subject of impact of wireless networks on human health, the same conclusion was reached: there is no convincing evidence that exposure to RF causes any health problems. However, there are some limitations as to how high a level of frequency people can be exposed to and it should be respected.

    References:

    [1] http://www.hps.org/hpspublications/articles/wirelessnetworks.html
    [2] http://www.who.int/mediacentre/factsheets/fs304/en/index.html
    [3] http://www.hps.org/hpspublications/articles/wirelessnetworks.html
    [4] http://en.wikipedia.org/wiki/Wireless_electronic_devices_and_health