Medicine

Beware in Denver Salads sold at Safeway recalled due to Salmonella risk

Written by  on May 3, 2011

DENVER – The department of Public Health and Environment is recalling grape tomatoes sold in Colorado due to Salmonella risk. The recalled tomatoes were used in pre-packaged salads made by Taylor Farms Pacific for several stores. However, in Colorado, only products sold at Safeway stores are included in the recall.

According to a Safeway representative, the recalled products were pulled from store shelves on Sat. April 30. No illnesses have been reported.

The following Signature Café products sold at Safeway stores in Colorado are included in the recall:

- Chef salad in 11-oz. plastic trays with use by dates of 4/30/2011-5/5/2011 and UPC code 21130-06252

- Cobb salad in12-oz. plastic trays with use by dates of 4/30/2011-5/3/2011 and UPC code 21130-06251

- Greek salad in 13.5 oz. plastic tray with use by dates of 4/30/2011-5/3/2011 and 4/30/2011-5/5/2011, and UPC code 21130-06257

- Tomato mozzarella salad (sold at the deli counter) in varying sizes with use by dates of 4/30/2011-5/6/2011, 4/30/2011-5/7/2011, and 4/30/2011-5/8/2011, and UPC code 21256300000

Anyone who purchased any of the recalled products is advised to discard it or return it to the place of purchase for a refund.

Salmonella is a food-borne bacteria which cause serious and sometimes fatal infections in children, elderly and others with weakened immune systems. Healthy people infected with Salmonella often experience fever, diarrhea, nausea, vomiting and abdominal pain.

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Ebola Virus Outbreaks Table

Written by  on May 1, 2011

 

 Known Cases and Outbreaks of Ebola Hemorrhagic Fever, in Chronological Order Source: http://www.cdc.gov/

Year(s)

Country

Ebola subtype

Reported no.
of human cases

Reported no. (%) of deaths among cases

Situation

 
 
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Ebola Hemorrhagic Fever

Written by  on May 1, 2011

Table of Ebola Outbreaks

What is Ebola Virus?
Read more…

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Jonas Salk Developer of Polio Vaccine

Written by  on April 25, 2011

Biography: Jonas Salk Developer of Polio Vaccine Jonas Salk Date of birth: October 28, 1914 Jonas Salk Date of death: June 23, 1995 Back to Jonas Salk Biography In America in the 1950s, summertime was a time of fear and anxiety for many parents; this … by The American Academy of Achievement

In America in the 1950s, summertime was a time of fear and anxiety for many parents; this was the season when children by the thousands became infected with the crippling disease poliomyelitis, or polio. This burden of fear was lifted forever when it was announced that Dr. Jonas Salk had developed a vaccine against the disease. Salk became world-famous overnight, but his discovery was the result of many years of painstaking research.

Jonas Salk was born in New York City. His parents were Russian-Jewish immigrants who, although they themselves lacked formal education, were determined to see their children succeed, and encouraged them to study hard. Jonas Salk was the first member of his family to go to college. He entered the City College of New York intending to study law, but soon became intrigued by medical science.

While attending medical school at New York University, Salk was invited to spend a year researching influenza. The virus that causes flu had only recently been discovered and the young Salk was eager to learn if the virus could be deprived of its ability to infect, while still giving immunity to the illness. Salk succeeded in this attempt, which became the basis of his later work on polio.

After completing medical school and his internship, Salk returned to the study of influenza, the flu virus. World War II had begun, and public health experts feared a replay of the flu epidemic that had killed millions in the wake of the First World War. The development of vaccines controlled the spread of flu after the war and the epidemic of 1919 did not recur.

In 1947, Salk accepted an appointment to the University of Pittsburgh Medical School. While working there, with the National Foundation for Infantile Paralysis, Salk saw an opportunity to develop a vaccine against polio, and devoted himself to this work for the next eight years.

Salk 2In 1955 Salk’s years of research paid off. Human trials of the polio vaccine effectively protected the subject from the polio virus. When news of the discovery was made public on April 12, 1955, Salk was hailed as a miracle worker. He further endeared himself to the public by refusing to patent the vaccine. He had no desire to profit personally from the discovery, but merely wished to see the vaccine disseminated as widely as possible.

Salk’s vaccine was composed of “killed” polio virus, which retained the ability to immunize without running the risk of infecting the patient. A few years later, a vaccine made from live polio virus was developed, which could be administered orally, while Salk’s vaccine required injection. Further, there was some evidence that the “killed” vaccine failed to completely immunize the patient. In the U.S., public health authorities elected to distribute the “live” oral vaccine instead of Salk’s. Tragically, the preparation of live virus infected some patients with the disease, rather than immunizing them. Since the introduction of the original vaccine, the few new cases of polio reported in the United States were probably caused by the “live” vaccine which was intended to prevent them.

In countries where Salk’s vaccine has remained in use, the disease has been virtually eradicated.

Salk 3In 1963, Salk founded the Jonas Salk Institute for Biological Studies, an innovative center for medical and scientific research. Jonas Salk continued to conduct research and publish books, some written in collaboration with one or more of his sons, who are also medical scientists.

Salk’s published books include Man Unfolding (1972), The Survival of the Wisest(1973), World Population and Human Values: A New Reality (1981), and Anatomy of Reality (1983).

Dr. Salk’s last years were spent searching for a vaccine against AIDS. Jonas Salk died on June 23, 1995. He was 80 years old.

http://www.achievement.org

 

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The Polio Crusade

Written by  on April 25, 2011

In the summer of 1950 fear gripped the residents of Wytheville, Virginia. Movie theaters shut down, baseball games were cancelled and panicky parents kept their children indoors — anything to keep them safe from an invisible invader. Outsiders sped t…
American Experience: The Polio Crusade
Airs Monday, April 12, 2010 at 9 p.m. on KPBS TV

Credit: March of Dimes

Above: Nurse and child with polio. This program is the story of the largest public health experiment in American history — the effort to eradicate polio, one of the 20th-century’s most dreaded diseases.
April 9, 2010
It was the largest public health experiment in American history – a crusade that eradicated polio, one of the 20th century’s most dreaded diseases. The polio epidemic terrified Americans for decades, affecting thousands of children, leaving many crippled, paralyzed or condemned to life in an iron lung.

Photo Gallery
In the mid-twentieth century, the National Foundation for Infantile Paralysis (predecessor to today’s March of Dimes) pioneered a new approach to philanthropy, raising money a dime at a time from millions of small donors. The nonprofit enlisted poster children, celebrities, presidents, and other partners in their high-profile campaigns. View the photos.
But on April 26, 1954, hope emerged. At the Franklin Sherman Elementary School in McLean, Virginia, six-year-old Randy Kerr stood at the head of a long line of children and waited patiently while a nurse gently rolled up his sleeve, then filled a syringe with a cherry-colored liquid containing the world’s first polio vaccine.

Developed just a few years earlier by virologist Jonas Salk, the polio vaccine had not yet been widely tested on humans. No one was certain it was safe or whether it could provide effective protection against the disease. In the coming weeks, nearly two million school children in 44 states received the shots. The Salk vaccine trials were the dramatic culmination of years of research and a multi-million dollar investment, made up in large part by public donations.

Based in part on David Oshinsky’s Pulitzer Prize-winning book, “Polio: An American Story,” “The Polio Crusade” chronicles a decades-long crusade, fueled by the bold leadership of a single philanthropy and its innovative public relations campaign, and features a bitter battle between two scientists and the breakthrough of a now-forgotten woman researcher.

The 20th-century effort to eradicate polio is chronicled. Included: lawyer Basil O’Connor (1892-1972), who developed the “March of Dimes” concept to help fund research; the competition between polio researchers Jonas Salk and Albert Sabin.

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Polio Virus

Written by  on April 25, 2011
Smithsonian National Museum of American History
Quote. To initiate infection, the virus must first attach to its cell-surface receptor and then deliver its RNA to the appropriate cellular compartment. End Quote. -David Belnap, biochemist, 2000
Poliomyelitis is a viral disease. There are three types of poliovirus and many strains of each type. The virus enters through the mouth and multiplies in the throat and gastrointestinal tract, then moves into the bloodstream and is carried to the central nervous system where it replicates and destroys the motor neuron cells. Motor neurons control the muscles for swallowing, circulation, respiration, and the trunk, arms, and legs.

Human nerve cells have a protruding protein structure on their surface whose precise function is unknown. When poliovirus encounters the nerve cells, the protruding receptors attach to the virus particle, and infection begins. Once inside the cell, the virus hijacks the cell’s assembly process, and makes thousands of copies of itself in hours. The virus kills the cell and then spreads to infect other cells.

Factoids
bullet Many types of human cells have receptors that fit the poliovirus; no one knows why the virus favors motor neurons over other cells for replication.
bullet For every 200 or so virus particles that encounter a susceptible cell, only one will successfully enter and replicate.
bullet In tissue culture, poliovirus enters cells and replicates in six to eight hours, yielding 10,000 to 100,000 virus particles per cell.
bullet One way the human immune system protects itself is by producingantibodies that engage the protein covering of the poliovirus, preventing the virus from interacting with another cell.
bullet There are three types of poliovirus: 1, 2, and 3. Type 1 is the most virulent and common. Both the Salk and Sabin vaccines are “trivalent” that is, active against all three virus types. Type 2 poliovirus has not been detected anywhere in the world since 1999.
bullet A person who gets polio is immune to future infection from the virus type that caused the polio.
Illustration of the poliovirus attached to neuron receptors
Poliovirus bound to a neuron receptor Illustration courtesy of Link Studio
Photo of poliovirus bronze models next to microscopic images
Scientifically accurate bronze models (without patina) of the poliovirus created for the Smithsonian by Edgar Meyer, 2005.
These models are an adaptation of James Hogle’s image of the poliovirus and were specially cast in bronze for the exhibit. They are the first three dimensioanl representations of the poliovirus

Poliovirus Capsid Model and Scientific Art
Scientists use many types of models to visualize concepts about the real world. Environmentalists and climatologists make computer graphics models of the entire earth. In 1953, James Watson and Francis Crick used a brass model of DNA‘s structure—the so-called “double helix”—as a physical analog of genes. All models are partly right and partly wrong because they represent only a level of knowledge at a given time. This bronze model of the poliovirus was made by for the exhibition by biochemist/artist Edgar Meyer, based on the first three-dimensional images of poliovirus that virologist James Hogle at Harvard obtained from X-ray crystallography in 2000. While the model represents the surface relief at a very high resolution, the shell (capsid) in nature is more complex than artwork or X-ray crystallography can show.

A Vaccine to Prevent Polio
Scientists could make vaccines even before they completely understood how they functioned. Eventually researchers learned that vaccines work by fooling the body’s immune system into producing antibodies even though there is no disease. Jonas Salk and Albert Sabin used this knowledge to create two different kinds of polio vaccines.

Life Cycle of the Poliovirus Animation (popup window)
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Illustration of the life cyle of the poliovirus
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Life cycle of the poliovirus
Illustration courtesy NMAH

Photo of James Hogle
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James Hogle in his Harvard Medical School lab, 2000

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