Published Research Proposes A System For Spreading Disease-Resisting Genes In Mosquito Populations

Scientists have modeled a system that may be used to control mosquitoes and the diseases they transmit, without the use of pesticides. In the proposed system, mosquitoes are engineered to carry two genes. The first gene causes males to transmit a toxin to females through their semen. The second gene, when expressed in females, makes them immune to this toxin. This research, published in the February 2011 issue of Genetics, describes a system that can be created using currently available molecular tools and could confine the spread of mosquitoes to isolated populations. It also allows the genes to be recalled if necessary.

“I hope that the results of this theoretical study will inspire molecular biologists to explore new ways of driving transgenes into populations,” said John M. Marshall, Ph.D., a researcher involved in the work from the Department of Infectious Disease Epidemiology, School of Public Health at the Imperial College of London in the United Kingdom. “Ultimately, I hope that the application of these ideas will help move transgenic mosquito technology forward, and thereby contribute to the many efforts to reduce the prevalence of malaria and dengue fever in disease-endemic countries.”

The gene transfer system was modeled using mathematical equations that describe how genetic alterations in the mosquitos’ DNA are inherited from one generation to the next, and predict how these alterations will either spread or be eliminated from the population. The system has two basic components – a toxin expressed in the semen of transgenic males that either kills female recipients or renders them infertile, and an antidote expressed in females that protects them from the effects of the toxin. An all-male release should result in population suppression because wild females that mate with transgenic males produce no offspring. A release that includes transgenic females propagates the desired gene because females carrying the toxin gene are favored at high population frequencies.

The scientists used simple population genetics models to explore the utility of this gene-transfer system, and found that it can work under a wide range of conditions. It requires a high frequency of gene transfer, which is desirable because it means that genetically altered insects released accidentally are unlikely to persist in the wild. Furthermore, it means that those released intentionally can be spatially confined and that the altered genes can be removed from a population through sustained release of wild-type insects. The scientists found few technical barriers to implementing this system, increasing prospects for engineering and testing in the coming years.

“Mosquito bites can mean more than an itchy annoyance,” said Mark Johnston, Editor-in-Chief of the journal Gentics. “For far too many people, they can lead to life-threatening diseases. But mosquitoes play a role in the greater ecosystem, and completely eradicating them may have unintended consequences that could be worse than the diseases they carry. This study is exciting because it suggests a way to control mosquito populations without pesticides, and in a way that gives us control of the process.”

Details:
John M. Marshall, Geoffrey W. Pittman, Anna B. Buchman, and Bruce A. Hay, Semele: A Killer-Male, Rescue-Female System for Suppression and Replacement of Insect Disease Vector Populations, Genetics 2011 187: 535.

Source:
Tracey DePellegrin Connelly
Genetics Society of America

Warnex Launches Test For Influenza A H1N1 Virus Mutation Associated With Resistance To Tamiflu(R)

Warnex Inc. (TSX:WNX) announced today that its Medical Laboratories division has launched a test for the detection of a mutation of the pandemic influenza A H1N1 virus, which is associated with resistance to Tamiflu®, a drug used for the treatment and prevention of the flu. The test specifically detects the H275Y mutation of the neuraminidase gene, which has been shown to cause resistance to Tamiflu.

“We have begun to see cases of Tamiflu resistance of the A H1N1 virus on a global scale, and recently also here in Quebec,” said Mark Busgang, President and CEO of Warnex. “We are offering this test for the identification of a Tamiflu-resistant strain in addition to our test for the rapid detection of the H1N1 flu virus, demonstrating the commitment of our Medical Laboratories division to serve as a reference laboratory and make available such highly specialized medical tests to the Canadian healthcare sector.”

Influenza A H1N1 virus, also known as human swine flu, is a variant of the influenza A virus which was first detected in people in April 2009 and has been declared a pandemic by the World Health Organization. The A H1N1 flu virus spreads from person to person, probably in much the same way as regular seasonal influenza viruses. The symptoms of this new flu virus are similar to the symptoms of seasonal flu and include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. A significant number of people who have been infected with this virus have also reported diarrhea and vomiting. Also, like seasonal flu, this virus can cause severe illness and death.

Source
Warnex

View drug information on Tamiflu capsule.

NICE Publishes Final Guidance On Clopidogrel And Modified-Release Dipyridamole For The Prevention Of Occlusive Vascular Events

NICE has published final guidance on the use of clopidogrel and modified-release dipyridamole for the prevention of occlusive vascular events (ischaemic stroke, transient ischaemic attack or heart attack). The guidance is for people at high risk of occlusive vascular events because they have previously had an ischaemic stroke, a heart attack, a transient ischaemic attack, or have been diagnosed with a condition called peripheral arterial disease. The guidance also makes specific recommendations for people who have cardiovascular disease in more than one vascular site (multivascular disease).

The guidance, which updates previous NICE guidance published in 2005, recommends:

– Clopidogrel (initiated with the least costly licensed preparation) as an option for people who have had an ischaemic stroke, who have peripheral arterial disease or who have multivascular disease. Clopidogrel is only recommended as an option for people who have had a heart attack if they cannot take aspirin.

– Modified-release dipyridamole plus aspirin as an option for people who have had a transient ischaemic attack. For people who have had an ischaemic stroke, modified-release dipyridamole plus aspirin should only be used where clopidogrel is contraindicated or not tolerated.

– Modified-release dipyridamole alone as an option for people who have had an ischaemic stroke or a transient ischaemic attack, only where treatment with aspirin and clopidogrel is contraindicated or not tolerated.

Professor Peter Littlejohns, Clinical and Public Health Director at NICE, said: “We know that heart attacks and strokes are some of the biggest killers and causes of disability, and that people who have had one heart attack or stroke are at a greater risk of having another. In the UK, it is estimated that each year 98,000 people have a first ischaemic stroke, as many as 65,000 people have a transient ischaemic attack and 146,000 have a heart attack. In addition, it is estimated that approximately 850,000 people aged 55-75 years have lower limb peripheral arterial disease, of whom 5% have symptoms. Today’s guidance for clopidogrel and modified release dipyridamole therefore has the potential to have a significant impact on the treatment of many thousands of patients in England and Wales.”

Notes

About the guidance

1. The NICE guidance on the use of clopidogrel and modified-release dipyridamole for the prevention of occlusive vascular events is available on the NICE website from 15 December 2010.

2. Clopidogrel is an irreversible adenosine diphosphate-receptor antagonist with antiplatelet properties. It has a marketing authorisation for the prevention of atherothrombotic events in adults who have had a MI (from a few days until less than 35 days), ischaemic stroke (from 7 days until less than 6 months) or established peripheral arterial disease. The cost of generic clopidogrel is ВЈ3.40 for 30 days. The cost of branded clopidogrel (Plavix, Sanofi-Aventis, Bristol-Myers Squibb) for 30 days at a dose of 75 mg daily is ВЈ35.64. Clopidogrel is not licensed for the treatment/prevention of transient ischaemic attacks and therefore recommendations could not be made about the use of clopidogrel in this patient population.

3. Modified-release dipyridamole (Persantin Retard and Asasantin Retard [combined with aspirin], Boehringer Ingelheim) has both antiplatelet and vasodilating properties. It has a marketing authorisation for the secondary prevention of ischaemic stroke and transient ischaemic attacks, either alone or in conjunction with aspirin. The 30 day cost of treatment with modified-release dipyridamole is ВЈ7.50.

4. In the UK, it is estimated that each year 98,000 people have a first ischaemic stroke, as many as 65,000 people have a TIA and 146,000 have a heart attack (or myocardial infarction – MI). In addition, it is estimated that approximately 850,000 people aged 55-75 years have lower limb PAD of whom 5% have symptoms. Stroke and MI are associated with a high morbidity and mortality. Some 30% of people die from their first MI. After a stroke, approximately 23% of people die within 30 days and the overall 3 year survival rate is only 30-40%. Stroke is also the leading cause of disability in the UK, with about 25-30% of people who survive a stroke remaining permanently disabled.

About occlusive vascular events

5. An occlusive vascular event can happen when a person has a build-up of fatty deposits on the walls of their arteries. The arteries become narrow and blood cannot flow properly – this is called vascular disease.

6. If a narrowed part of an artery is damaged, a blood clot can form. This blood clot can block the artery, or travel through the blood vessels to another part of the body and block the blood flow there. When an artery is blocked in this way it is known as an occlusive vascular event.

7. There are different types of occlusive vascular event depending on where the blockage occurs. If the blood supply to the brain is affected, the result can be a stroke (either an ischaemic stroke, or if it happens for only a short time, a transient ischaemic attack). If the blood supply to the heart is affected, a heart attack can result. Peripheral arterial disease (PAD) is caused by a narrowing of the arteries in the arms or legs and people with the disease are at high risk of heart attack or stroke.

Source:

NICE

View drug information on Plavix.

Impact Of Dialysis Modality On Posttransplantation Results In Kidney Transplantation

(UroToday) – We carried out a retrospective study of 78 patients (39 were on PD and 39 on HD) who had their first renal transplantation between January 1986 and December 2004.

The following patient parameters were noted: age, gender, cadaveric donors (D), mean period of dialysis, mean transplantation (TR) follow-up, mean duration of first hospital stay (FH), first infection, post-transplant diabetes mellitus, acute tubular necrosis (ATN), acute rejection and patient and graft actuarial survival.

Patients were split up into two groups depending on whether they had had PD or HD before transplantation. Patients who were grafted in the same period, in the same centre and who were matched for age and sex were split up into 2 groups depending on whether they had had PD or HD. Diabetics were excluded from this study.

Analytical methods – Comparisons between groups were made using Chi-square test for qualitative parameters and non-paired student’s t-test for continuous variable. Statistical significance was accepted for p less than 0.05. Comparisons between actuarial curves of patient and technique survival were made using Logrank test. All analyses used StatView logiciel

I. Helal, MD, as part of Beyond the Abstract on UroToday. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc… of their research by referencing the published abstract.

Link to Full Abstract

UroToday – the only urology website with original content global urology key opinion leaders actively engaged in clinical practice.

To access the latest urology news releases from UroToday, go to:
www.urotoday

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Stricter Hand Hygiene In Schools Only A Short-Term Measure For Fighting Swine Flu

Increased hand hygiene in primary schools is only a short-term measure in preventing infections such as H1N1 from spreading. Researchers writing in the open access journal, BMC Public Health, found stricter hand hygiene practices are difficult to maintain in a school setting.

School children may be twice as likely to catch H1N1 influenza as adults, as such health policies often stress hand hygiene among school children as one low cost intervention that may prevent influenza from spreading.

A research team led by Wolf-Peter Schmidt at the London School of Hygiene and Tropical Medicine, London, UK used qualitative methods to explore teachers’ and students’ views on different hand hygiene protocols, as well as interviewing school nurses. Their pilot study in four East London primary schools examined both practical issues and attitudes, and included class exercises in hand washing or lining up to use hand sanitizer.

The researchers found that staff are motivated to contribute to hygiene education over and above what children learn from their parents, provided that expectations are realistic for the school environment. But very frequent and highly monitored hand washing would be hard to keep up over the longer term without the motivation of a major perceived public health threat like the current influenza pandemic. During a busy school day, time was a major factor in deciding what level of hand hygiene could be achieved.

School nurses were more focused on reducing infection, whereas teachers saw hygiene as an important education topic – particularly among the younger age groups. Rinse-free alcohol gel hand sanitizer was the fastest and least messy option. But teachers highlighted to children that this was only for situations where soap and water was in short supply.

“Intensive hand hygiene interventions are feasible and acceptable but only temporarily during a period of a particular health threat like an influenza pandemic and only if rinse-free hand sanitizers are used,” according to Schmidt. “In many settings there may be logistical issues in providing all schools with an adequate supply,” he added. “Hand hygiene is important in particular for the prevention of gastro-intestinal infections. The effect of hand hygiene on the spread of influenza is less clear, but may be promoted as a precautionary measure, even in the absence of evidence. Our study highlights the practical issues of bringing improved hand hygiene to scale.”

Notes:

To increase awareness of the importance of handwashing, the 15th of October will mark the 2nd Global Handwashing Day. Global Handwashing Day 2009 will be the centerpiece of a week of activities that will mobilize millions of people in more than 70 countries across all five continents to wash their hands with soap.

Formative research on the feasibility of hygiene interventions for influenza control in UK primary schools
Wolf-Peter Schmidt, Catherine Wloch, Adam Biran, Val Curtis and Punam Pangtani
BMC Public Health (in press)
biomedcentral/bmcpublichealth/

Source:
Charlotte Webber

BioMed Central

Residents In Aged Care Facilities Malnourished, Australia

Australia’s peak nutrition body is calling on the Government to tackle ‘shocking’ rates of
malnutrition in Australia’s aged care facilities, where around one in two residents is
malnourished1.

In its submission to the Government’s Aged Care Funding Instrument (ACFI) review2, the
Dietitians Association of Australia (DAA) called for routine nutrition screening, and better
support for nursing and other care staff to feed and weigh residents and monitor their food
intake.

DAA’s President Julie Dundon said: ‘We’ve heard so much about obesity but at the other end
of the scale malnutrition is causing unnecessary suffering. Malnourished aged care residents
are at higher risk of falls and fractures, infections like bed ulcers, and medical complications
- all at a huge cost to the tax payer.’

Ms Dundon said unintentional weight loss needed to be picked up early and steps put in place
to improve the nutritional status of these residents.

‘Pharmacists are already funded to regularly review the medicines taken by residents. We’re
suggesting a similar model, where money could be set aside for Accredited Practising
Dietitians (APDs) to coordinate routine nutrition screening and carry out nutrition
assessments3.’

She said the tragedy of malnutrition is likely to get worse as the Australian population ages.
‘As the link between malnutrition and a poorer quality of life and health outcomes is well
known, the Government needs to give serious attention to the nutritional care of older
people,’ said Ms Dundon.

In its submission to the ACFI review DAA also called for:

– Government funding for:

- aged care residents to be able to better access APDs
- facility staff to work with APDs on planning nutrition care
- APDs to work on activities like facility-wide menu assessments, staff training and
quality improvement projects

– Publicly available Government reports on the rates of malnutrition in Australia
– National standards for menu planning in the aged care setting
– Mandatory training of aged care staff in correct techniques for weighing and feeding
residents.

Background

– The Dietitians Association of Australia has recently developed comprehensive,
evidence-based practice guidelines to help dietitians manage malnutrition.

– The Government subsidises aged care homes to provide care to older people who can
no longer remain in their own homes. The amount of Government funding is worked
out through the Aged Care Funding Instrument, which was introduced in March
20084.

– In 2009-10, around 210,000 Australians will receive subsidised residential aged care
in one of Australia’s nearly 2,800 aged care homes. And the Australian Government
will provide around $7 billion to support the provision of these residential aged care
services3.

– Between 2011 and 2021, the Australian population aged 65 years and over is
projected to grow from three to five million. And the proportion of Australians 85
year and older is projected to increase from 1.6 per cent in 2007 to between 4.9 and
7.3 per cent in 20565.

1 Gaskill D, Black LJ, Isenring EA, et al. Malnutrition prevalence and nutrition issues in residential aged care
facilities. Australasian Journal of Ageing 2008; 27:189-94.

2 Submission from the Dietitians Association of Australia to the Department of Health and Ageing Review of
the Aged Care Funding Instrument. Available here.

3 DAA’s Rehabilitation and Aged Care Interest Group Convenor, Karyn Matterson APD, initiated and
developed the RNMR concept. Further details on this can be obtained from Karyn on (02) 9216 9003 or via
email karyndietonline.au

4 Department of Health and Ageing. New funding model for residential aged care. Available here.

5 Australian Bureau of Statistics. Scenarios for Australia’s ageing population. Available here.

Source
Dietitians Association of Australia

A Model For Public Health Preparedness: Flu Pandemic In Prison

When pandemics occur, correctional facilities are not immune. With more than 9 million people incarcerated across the globe 2.25 million in U.S. jails and prisons alone it is vital that correctional officials and health professionals be prepared for a worst-case scenario that involves pandemic influenza reaching inmates and staff.

With collaborative planning and training, prison and public health officials can help control influenza outbreaks behind bars, according to an article in the April issue of the Journal of Correctional Health Care (published by SAGE).

A two-day conference on prison pandemic preparedness held in Georgia in 2007 could serve as a model for such training. Administrators, medical doctors, registered nurses, physician assistants, and pharmacists were among the participants, as well as state and local public health officials.

The objectives were to educate participants about pandemic flu issues in prison settings, provide impetus for initial planning in Georgia’s prisons, and elicit ideas about how the prisons could best prepare for and respond to pandemic flu. Topics included nonpharmaceutical interventions, health care surge capacity, and prison-community interfaces.

Effective training about pandemic influenza requires more than just classroom lectures or checklists, the authors write. The conference employed interactive methods and educational games that recent studies have found effective in training ”adult learners.” Experiential learning closely resembles the way adults learn on the job and offers a more hands-on approach compared to traditional didactic, classroom-based learning.

The training techniques appeared to be very effective. Scores on a test after the training were an average of 69% correct compared to a pretest, which had an average score of 42% correct.

As important, the conference served to forge new partnerships among correctional health and public health officials responsible for pandemic planning.

The article, “How Public Health and Prisons Can Partner for Pandemic Influenza Preparedness: A Report From Georgia” in the April issue of the Journal of Correctional Health Care can be accessed free for a limited time at jcx.sagepub/cgi/reprint/15/2/118.

Source:
Jim Gilden

SAGE Publications

Greater Risk For Cardiac Stress On Airline Flights For People With Obstructive Sleep Apnea

People with severe obstructive sleep apnea (OSA) on commercial airline flights may have a greater risk of adverse events from cardiac stress than healthy people, according to new research presented at the American Thoracic Society’s 2008 International Conference in Toronto.

The researchers compared oxygen levels and ventilation of healthy people and people with severe OSA during simulated flight conditions replicating the oxygen and pressure levels of typical commercial flights that have “cabin altitudes” (a measure of the air pressure and oxygen) ranging from 6,000 feet and 8,000 feet – the maximum allowed, even if the airplane is flying at 30,000 feet. This is the first study to use these measurements to assess fitness to fly without supplemental oxygen.

“It is normal for the rate of breathing to increase when air pressure falls. We predicted that patients with OSA would have a much sharper fall in oxygen levels because they might not increase their breathing as much,” said Leigh Seccombe, M.Sc., senior scientist in the Department of Thoracic Medicine at Concord Repatriation General Hospital in Sydney, Australia. “And in fact, we found that patients with OSA do have a lower blood oxygen level before and during aircraft cabin condition stimulation, but that the change in oxygen was similar. We also found that their breathing intensity increases at about the same rate as it does in healthy people.”

But what was different was the physiological stress and demand for oxygen was increased in people with OSA. “In short, the work they do to run the core range of body functions (heart, lungs, brain) is much greater under cabin conditions,” explained Ms. Seccombe, who is currently part of a group working on a consensus statement which will help guide respiratory physicians as to whether their patients are at risk from air travel.

“We addressed OSA because it is becoming so much more common as obesity increases and there are greater numbers of obese passengers on commercial flights,” said Ms. Seccombe. “Half of the patients with OSA would require supplemental oxygen in-flight if current guidelines (for those with lung disease) were strictly followed if these results are typical.”

###

Source: Keely Savoie

American Thoracic Society

GSA’s Annual Meeting To Present New Research On Aging: Education And The Gerontological Imagination

Dallas, TX is the location for The Gerontological Society of America’s 59th Annual Scientific Meeting, held in conjunction with the American Federation for Aging Research. The Adams Mark Dallas (adamsmark/dallas/) will accommodate the entire conference the country’s largest in the field of gerontology at their complex from November 16th through 20th, 2006. Nearly 4,000 individuals will attend.

The five-day meeting will focus on a wide range of aging topics chosen by leading experts to showcase cutting-edge research in the field. This online schedule demonstrates the scope of the presentations: agingconference/conference_program.cfm.

The following are selected conference highlights:

*
Opening Session: GSA welcomes one of Great Britain’s leading aging experts, Dr. Thomas Kirkwood

*
The GSA Task Force on Women Symposium: “Income Security Among Future Cohorts of Older Women”

* The Ollie Randall Symposium: “Understanding Older Americans’ Long-Term Care Use and Well Being in Dynamic Social and Policy Contexts”

* Closing Session: “Ethical Dilemmas in Care for the Elderly”

###

Founded in 1945, The Gerontological Society of America is the nation’s oldest and largest multidisciplinary scientific organization devoted to the advancement of gerontological research. The Society’s membership includes more than 5,000 researchers, educators, practitioners, and other professionals in the field of aging. The National Academy on an Aging Society is the policy institute of GSA. For more information on GSA and the Academy, visit geron/.

Contact: Todd Kluss

The Gerontological Society of America

Avian Flu Virus Unlikely To Spread Through Wastewater And Drinking Water Treatment Systems, Cornell Researchers Find

A close relative of the highly pathogenic avian influenza virus (H5N1) can be eliminated by waste and drinking water treatments, including chlorination, ultraviolet (UV) radiation and bacterial digesters. The virus is harmless to humans but provides a study case of the pathways by which the influenza could spread to human populations.

Cornell researchers studied the related virus, called H5N2, to see whether a hypothetical mutated form of H5N1 could infect people through drinking and wastewater systems. Researchers at Cornell and the U.S. Military Academy at West Point collaborated on the study, published in a recent issue of Environmental Engineering Science.

H5N2, a low-pathogenic avian influenza virus that is not contagious for humans, is physically similar to H5N1, which has been lethal to millions of birds globally and more than half of the almost 200 infected people mostly through handling infected birds, since 2003. Researchers and officials are concerned that if H5N1 mutates to transmit easily between people, a deadly global pandemic could occur.

“It is unknown if H5N1 is more resistant” than H5N2 to procedures used by the water management industry, said Araceli Lucio-Forster, the paper’s lead author and a teaching support specialist in Cornell’s Department of Microbiology and Immunology. Lucio-Forster will receive her Ph.D. in microbiology from Cornell in January 2007.

Because H5N1 requires high-level biosafety facilities, Lucio-Forster and colleagues used H5N2 as a surrogate virus. Given the similarities between the two viruses, she thinks that if H5N1 entered the water treatment system, “the virus should be inactivated, which means treated water may not be a likely source of transmission,” said Lucio-Forster.

Overall, avian flu viruses do not survive well outside of a host. Still, the researchers tried to address concerns in the wastewater-treatment industry that if a human outbreak occurred, contaminated feces passing through the plant could infect plant workers and spread elsewhere through drinking water.

“You have some 50,000 treatment plants in the U.S., and all these operators that run the plants were concerned that if there were an influenza outbreak and everyone were sick, is it going to come into the plant and infect them and others,” said co-author Dwight Bowman, a professor of parasitology at Cornell.

To test the effectiveness of UV radiation for killing the H5N2 virus, the researchers exposed the virus in drinking water as well as in wastewater effluents to UV light at varying levels. The treatment was very effective in killing H5N2 at levels well within industry standards (and at lower levels than are used for killing Cryptosporidium and Giardia in water).

For chlorine, which is mostly ubiquitous in U.S. drinking water, the results were less definitive. Inactivation of H5N2 depends on both chlorine concentrations and time of exposure. On average, U.S. treatment plants treat drinking water with chlorine concentrations of 1 milligram per liter for 237 minutes. Under these conditions, the researchers found that H5N2 (and probably H5N1) would be mostly inactivated, but further studies are needed to see if the viruses stay active when they come out of feces or are at different pH and salinity levels.

Similarly, the small laboratory-scale study found that bacterial digesters also reduced H5N2 to undetectable levels after 72 hours, which is consistent with industry standards. The researchers also found that higher digester temperatures inactivated the virus more quickly.

The UV and chlorine tests were conducted at the U.S. Military Academy.

Contact: Press Relations Office

Cornell University News Service