Leukemia: Development of White Blood Cells

There are five types of leukocytes (white blood cells) found in the blood:

Basophils
Eosinophils
Lymphocytes
Monocytes
Neutrophils

Each cell type has a specific role to play in our body's immune system. Important overall functions of the immune system include defense against invading microorganisms, removal of dead or damaged cells, and destruction of cancer cells.

Blood cell formation begins with a special cell located in the bone marrow called a hematopoietic stem cell. Unlike most cells, the hematopoietic stem cell has the capability for self-renewal as well as the ability to give rise to any one of the separate blood cell types. This means that as the stem cell divides in two, one cell replaces the original stem cell and the other begins the multi-step process of developing into a mature blood cell.

It is important to note that hematopoietic stem cells are different from embryonic stem cells. While hematopoietic stem cells can develop into any type of blood cell, embryonic stem cells can develop into any cell type in the body.

Blood cell precursors usually progress through a series of stages in the bone marrow before entering the circulating blood stream. Signals from surrounding cells in the bone marrow can help stimulate stem cells to divide as well as develop and mature into specific blood cell types. Normal cell division is also regulated by an important process known as the cell cycle. Disruption of this process is central to the development of leukemia.

Conflicts of Interest Still Exist in Cancer Research

MONDAY, May 11 (HealthDay News) -- A recent analysis of major medical journals has found many potential conflicts of interest between researchers and medical industry companies, raising concern that investigators may at least be tempted to report favorable results to help the financial backers of their work.

The analysis, to be published in the June 15 issue of Cancer and headed by the University of Michigan, looked at more than 1,500 cancer studies published in eight authoritative journals, including Cancer, the New England Journal of Medicine and the Lancet, during a recent year and found:

-Randomized clinical trials that assessed patient survival were more likely to link a survival advantage to the medical treatment being studied when a conflict of interest was present.

-These trials, the authors noted, are how drugs, technologies, procedures and so on eventually get approved for use in medical practices.

-Apparent conflicts of interest (such as industry funding, consulting fees to authors and co-authorship by industry employees) found simply by reviewing the authorship credits were noted in 29% of studies, while 17% actually declared industry funding.

-Industry-funded studies focused on treatment in 62% of cases, whereas only 36% of studies done without industry funding focused on treatment.

-While 47% of studies done without industry funding looked at epidemiology, prevention, risk factors, screening or diagnostic methods, only 20% of industry-funded studies focused on these areas.

Researchers are often required to disclose potential conflicts of interest to medical journals when they submit articles, but the lines can get blurry. While taking a consulting fee or holding a job in the companies whose products they are evaluating is an obvious potential conflict of interest, some researchers may knowingly or unknowingly hold stock in the companies, for example.

As a result, the authors of the analysis wrote that "attempts to disentangle the cancer research effort from industry merit further attention, and journals should embrace both rigorous standards of disclosure and heightened scrutiny when conflicts exist."

-- Kevin McKeever
SOURCE: American Cancer Society, news release, May 11, 2009

Mushroom-Possible Therapeutic Benefits and Facts

Possible Therapeutic Benefits:

- Thins the blood

- Prevents cancer in animal

- Lowers blood cholesterol

- Stimulates the immune system

- Inactivates viruses

Facts:

So far few medicinal benefits are linked to the common button mushroom popular in the United States, but Oriental mushrooms contain compounds that can stimulate the immune system, inhibit blood clotting, and retard the development of cancer. The magical four with proven value: shiitake, oyster, enoki, and tree ear, also called wood ear and mo-er.

Japanese scientists have extensively analyzed the medicinal qualities of mushrooms, especailly shiitake, increasinly cultivated and eaten in United States. What makes these mushrooms unusually exciting to scientists is that some possess stimulating or potentiating properties that may strengthen the immune system against not only a variety of infections, but cancer and possibly autoimmune diseases such as rheumatoid arthritis, polyarthritis, and multiple sclerosis.

Gastric Cancer Overview

Overview

The stomach is part of the digestive system. It is located in the upper abdomen, between the esophagus and the small intestine. Stomach cancer is also called gastric cancer.

Most (85%) cases of gastric cancer are adenocarcinomas that occur in the lining of the stomach (mucosa). Approximately 40% of cases develop in the lower part of the stomach (pylorus); 40% develop in the middle part (body); and 15% develop in the upper part (cardia). In about 10% of cases, cancer develops in more than one part of the organ.

Stomach cancer can spread (metastasize) to the esophagus or the small intestine, and can extend through the stomach wall to nearby lymph nodes and organs (e.g., liver, pancreas, colon). It also can metastasize to other parts of the body (e.g., lungs, ovaries, bones).

Incidence

According to the National Cancer Institute (NCI), approximately 760,000 cases of stomach cancer are diagnosed worldwide and more than 24,000 cases are diagnosed in the United States each year. Incidence is highest in Japan, South America, Eastern Europe, and parts of the Middle East. Worldwide, stomach cancer is the second leading cause of cancer-related deaths.

Stomach cancer occurs twice as often in men and it is more common in people over the age of 55. In the United States, incidence is higher in African Americans than in Caucasians.

Changes in diet and food preparation have led to a recent decrease in the incidence of cancer of the lower stomach (distal gastric cancer). However, incidence of cancer of the upper stomach (proximal gastric cancer) has increased, primarily as a result of the prevalence of obesity and gastroesophageal reflux disease (GERD).

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Banana Build a Better Stomach

Wonder of wonders, that's what experts say plantains do; they strengthen the surface cells of the stomach lining, forming a sturdier barrier against noxious juices. The British experimenters were stunned to notice that the mucosa, or stomach lining, was actually visibly much thicker in rats fed banana powder. As a sideline experiment, they deliberately fed rats banana powder or aspirin and other chemicals to see what happened to this critical barrier. It grew considerably thicker with banana powder, decreased substantially with aspirin, and ever more with Tagamet. But the rats fed both banana and aspirin, the banana counteracted the drug's detrimental erosive effects; the lining still jumped in thickness by about twenty percent.

Thus, researchers say banana stimulates the proliferation of cell in the stomach lining, and also triggers the release of a protecting stomach hydrochloric acid and pepsin from doing further damage. The British researchers' bottom line: "The role of banana is folk medicine as an anti-ulcerogenic agent, at least against gastric ulcers, appears justified..."

Swine Flu Outbreak

What is swine flu and how can humans catch it?
Updated Sun. Apr. 26 2009 12:33 PM ET
Angela Mulholland, CTV.ca News

What is swine flu?
Like humans, pigs get the flu. They develop a sudden fever, a barking cough, sneezing, lethargy and typically lose their appetite.
Pigs usually don't die from swine flu; their flu viruses cause high levels of illness but low death rates.
Swine influenza viruses circulate among pigs throughout the year, but most outbreaks occur during the late fall and winter, just like with outbreaks in humans.
Most swine flu viruses belong to the Influenza A H1N1 and H3N2 subtypes.

Can humans catch swine flu?
Normally, swine flu bugs don't infect people. When they do, it's been in people who have direct contact with pigs; historically, there's such a case every year or two in the U.S. between Dec. 2005 and Feb. 2009, there were12 human swine flu infections in the U.S. -- about four a year.
It's possible this uptick was due to improved reporting systems, but the U.S. Centers for Disease Control says "genetic changes in swine flu viruses and other factors might also be a factor."
Since March 2009, a number of confirmed human cases of a new strain of swine influenza A (H1N1) virus infection in the U.S. and internationally have been identified.

Can humans pass swine flu?
Usually no. But what makes this new outbreak worrisome is that in all the recent cases, none had any direct contact with pigs.
Two of the new cases were among 16-year-olds at the same school in San Antonio and there's a father-daughter pair in California, said CDC's Dr. Anne Schuchat.

Is this a new kind of swine flu?
Yes. The CDC reports that the virus in these latest cases is a never-before-seen mixture of viruses typical among pigs, birds and humans.
The influenza A H1N1 virus contains DNA typical to avian, swine and human viruses, including elements from European and Asian swine viruses.
Although it's called swine flu, this new strain is not infecting pigs and has never been seen in pigs.

Why would a new strain be worrisome?
Epidemiologists have been warning for years that it's just a matter of time before a new strain of the flu emerges that has the potential to kill millions. Flu pandemics have historically occurred about three times per century and the world hasn't seen one in more than 40 years.
If an influenza virus changes and becomes a new strain against which people have little or no immunity -- and this new strain is easily spread from person to person – many people around the world could become ill and die.
The World Health Organization estimates that in the best case scenario, the next pandemic could kill two to seven million people and send tens of millions to hospital.

Is there a vaccine?
There is a vaccine available that can be given to pigs to prevent swine influenza. But there is no vaccine to protect humans from swine flu.

I got the flu shot this year. Am I protected?
No. H1N1 swine flu viruses are very different from human H1N1 viruses and, therefore, vaccines for human flu would not provide protection from H1N1 swine flu viruses.

Can people catch swine flu from eating pork?
No. Swine influenza viruses are not transmitted by food; you cannot get swine influenza from eating pork or pork products.

What are the symptoms of swine flu in humans?
Symptoms of swine flu are similar to those of our regular flu, with sudden onset of:
• Fever
• Lethargy
• Lack of appetite
• Coughing

Some people with swine flu also have reported:
• Runny nose
• Sore throat
• Nausea, vomiting and diarrhea.

How is the virus transmitted?
Human-to-human transmission of swine flu is believed to occur the same way as seasonal flu, mainly through coughing or sneezing of people infected with the influenza virus.
People also can become infected by touching something with flu viruses on it and then touching their mouth or nose.

Can we treat swine flu in humans?
Yes. Most swine influenza viruses have been treated with antiviral medications.
The virus from the most recent U.S. swine flu cases appeared to be resistant to amantadine and rimantadine but was susceptible to zanamivir and oseltamivir (Tamiflu).

Have there been swine flu outbreaks before?
Yes. Most famously, there was an outbreak in 1976 at Fort Dix, N.J., among military recruits that grabbed big headlines at the time.
Worried that they had the beginning of a pandemic on their hands, U.S. officials ordered the manufacture of swine flu vaccine and the country launched a mass immunization program that saw about 40 million people vaccinated.
But the outbreak didn't turn into a pandemic and went away as mysteriously as it appeared.

Sources: The Canadian Press, Public Health Agency of Canada and the U.S. Centers for
Disease Control

What Is Asthma?

Asthma (AZ-ma) is a chronic (long-term) lung disease that inflames and narrows the airways. Asthma causes recurring periods of wheezing (a whistling sound when you breathe), chest tightness, shortness of breath, and coughing. The coughing often occurs at night or early in the morning.
Asthma affects people of all ages, but it most often starts in childhood. In the United States, more than 22 million people are known to have asthma. Nearly 6 million of these people are children.