Recently published research in PLoS ONE reported a breakthrough in the development of broad-spectrum antiviral therapy, theoretically capable of working against all types of viruses, from naturally emerging viruses such as influenza and SARS to clinical viruses like hepatitis and HIV.

Viruses are very small acellular organisms that, when introduced into another organism, invade and commandeer cells in order to replicate and spread themselves. When viruses attempt to replicate themselves, the host organism usually has an immune system response which disrupts the replication process. Yet many viruses such as HIV can outsmart the immune system, leading to continued vira

l replication that can cause serious damage to the organism.

There are both preventative and therapeutic treatment options available to deal with viruses, but they have several limitations. For instance, vaccines can be used to build up strong immune system responses to specific viruses, which ensure that if the organism does become exposed to the virus, it is able to fight the virus off. However, vaccines usually need to be administered prior to (or in some cases shortly after) exposure of the virus, which is not always possible. In addition, when dealing with emerging infectious diseases such as SARS (which was unpredictable and quickly spread between people in Toronto), there is often little time to develop and administer vaccines to the public.

Therapeutic treatment options also exist, which can be used to treat viral infections post-exposure. The success of this type of treatment can be seen in how it has helped prolong the life of people who have contracted HIV. Nevertheless, this class of treatment is also subject to the same limitations as vaccines and can moreover become ineffective if the virus mutates and becomes resistant to the drug.

In response to these treatment limitations, Dr. Todd Rider and his colleagues from the Massachusetts Institute of Technology developed a new antiviral drug called Double-Stranded RNA Activated Caspase Oligerizer (DRACO), which targets cells that have been infected by a virus. When viruses attempt to replicate themselves in cells, they often create long strings of double-stranded RNA that are not found in regular human or animal cells. This approach works by specifically targeting the cells that have these long strings of double-stranded RNA and causes them to undergo apoptosis (programmed cell suicide) while ignoring all the other healthy cells.

In his research, Dr. Rider tested the new drug on 15 different viruses (including the common cold, H1N1 influenza, and polio virus) and it was effective against them all. Although his earlier research was primarily conducted on mammalian cells cultured in a lab (which leaves open the possibility that the drug might not work on living animals), his most recent work has focused on the effect of the drug on mice infected with influenza and has led to some promising results. As a broad-spectrum antiviral drug, the development of DRACO has tremendous potential to impact the treatment of viral diseases. More research and time will tell whether this drug ends up being safe and effective for the treatment of viral infections in humans.

Obesity May Explain Liver Cancer Hike Among Latinos

By: ALICIA AULT, Oncology Report Digital Network

WASHINGTON – A combination of risk factors may be driving a large increase in liver cancer among Latinos in the United States, researchers said at a conference sponsored by the American Association for Cancer Research.

Although liver cancer, or hepatocellular carcinoma (HCC), is most common in Asia and Africa, the incidence is on the rise in the United States, primarily due to hepatitis C virus infection. There are 20,000 new HCC cases in this country each year, and liver cancer is the fifth most common cancer in men and the seventh most common in women, according to a recent review article in the New England Journal of Medicine (2011;365:1118-27).

The main risk factors for HCC in Africa and Asia have been infection with hepatitis B or hepatitis C, and alcoholic liver disease. More recently, evidence has suggested that fatty liver disease and metabolic syndrome may be significant risk factors in Western countries, according to the NEJM review.

In the United States, HCC incidence was 1.7 cases per 100,000 in 1980, but by 2005, this figure had increased to 5 per 100,000, noted the lead author of the Texas study, Amelie Ramirez, Dr.P.H., who presented the data at the conference. Dr. Ramirez, director of the Institute for Health Promotion Research at the University of Texas Health Science Center at San Antonio, and her colleagues decided to see if they could tease out some risk factors for HCC and thereby help to explain the increase among Latinos living in that state.

The investigators used data from the U.S. Surveillance, Epidemiology, and End Results (SEER) program, the Texas Cancer Registry, and the Texas Department of State Health Services. They examined the time period 1995-2006 and calculated age-adjusted and age-specific HCC incidence rates as well as the prevalence of obesity, diabetes, heavy alcohol use, and smoking.

Dr. Ramirez and her colleagues found that Latinos accounted for one third of HCC cases in Texas, and about 75% of cases in South Texas. The rates were 10.6 cases per 100,000 in South Texas and 9.7 per 100,000 in the state, compared with 7.5 per 100,000 among Latinos nationally in the SEER database. About 70% of cases were in men, an observation that held across all three populations – SEER, Texas, and South Texas.

Latinos are the fastest-growing U.S. minority group, accounting for 20% of the total U.S. population and 36% of the population of Texas; by the year 2030, Latinos will constitute a majority of Texas’ census, Dr. Ramirez noted (U.S. Census Bureau, 2010). This pattern is especially pronounced in South Texas, a large region that is currently almost 70% Latino.

The researchers also documented increases in the prevalence of obesity and diabetes among Texas and South Texas Latinos. When they analyzed the time periods 1995-1997 and 2004-2006 separately, the researchers found that obesity for all Latinos increased. During 2004-2006, Texas and South Texas Latinos had higher rates of obesity than U.S. Latinos overall. For U.S. Latinos, the obesity rate was 27%, compared with 30% for Texas Latinos and 35% for South Texas Latinos.

Diabetes prevalence also increased among U.S. Latinos overall, while the prevalence figures for South Texas and Texas Latinos showed increases, but they were not significant.

Heavy alcohol use and smoking did not appear to be significant risk factors for HCC in the analyses. However, the study shows that obesity and diabetes, both of which are preventable and treatable, should receive more attention in the Latino population, especially in Texas, Dr. Ramirez said.