Omega 3 acids could protect from blindness

Increasing the dietary intake of Omega 3 fatty acids, found in certain kinds of fish, nuts and vegetable oils, may protect one from blindness, suggests a study conducted on mice.

Scientists in Boston found that they have a protective effect against blindness resulting from abnormal blood vessel growth in the eye, according to the study published in the online journal Nature Medicine.

Human clinical trials will soon begin at a children's hospital in Boston to test the effects of Omega 3 supplementation in premature babies who are at risk for vision loss, the researchers were quoted as saying by science portal EurekAlert.

Omega 3 fatty acids are already known to be beneficial for heart and brain functions. Short-term studies have indicated that taking dietary supplements of Omega 3 could also lower blood pressure in people with hypertension.

Abnormal vessel growth is the cause of retinopathy - an eye disease that leads to the eventual loss of vision. It begins with a loss of blood vessels in the retina, which becomes oxygen starved, sends out alarm signals and spurs new vessel growth. But the new vessels grow abnormally and are malformed, leaky and over-abundant.

The abnormal vessels finally pull the retina away from its supporting layer, and this retinal detachment ultimately causes blindness.

The researchers, led by Lois Smith and Kip Connor of Children's Hospital in Boston and Harvard Medical School, and John Paul SanGiovanni of the National Eye Institute (NEI) studied retinopathy in mice, feeding them a diet rich in Omega-3 fatty acids.

Mice on the Omega 3 diet had less initial vessel loss in the retina than those fed with Omega 6 fatty acids. The area with vessel loss was 40-50 percent smaller.

'Our studies suggest that after initial loss, vessels re-grew quickly and efficiently in the Omega 3-fed mice,' Connor said.

'This increased the oxygen supply to retinal tissue, resulting in a dampening of the inflammatory 'alarm' signals that lead to pathologic vessel growth.'

Apple might keep cancer at bay

Apple peel may either inhibit or kill cancer cells, a Cornell University research has found.

Cornell researchers analyzed the peel from 230 pounds of red delicious apples and isolated their individual compounds.

After identifying the structures of the promising compounds in the peel, the researchers tested the pure compounds against cancer cell growth in the laboratory.

They identified a dozen compounds -- triterpenoids -- in apple peel that either inhibit or kill cancer cells in laboratory cultures, according to the research published this month in the Journal of Agricultural and Food Chemistry.

Three of the compounds have not previously been described in the literature.

Lead researcher Rui Hai Liu, Cornell associate professor of food science, said three of the compounds have not previously been described in the literature.

'We found that several compounds have potent anti-proliferative activities against human liver, colon and breast cancer cells and may be partially responsible for the anti-cancer activities of whole apples,' said Liu.

In previous Cornell studies, apples had been found not only to fight cancer cells in the laboratory but also to reduce the number and size of mammary tumors in rats. The Cornell researchers now think that the triterpenoids may be doing much of the anti-cancer work.

'We believe that a recommendation that consumers to eat five to 12 servings of a wide variety of fruits and vegetables daily is appropriate to reduce the risks of chronic diseases, including cancer, and to meet nutrient requirements for optimum health,' said Liu.

Women cause of infertility in men!

Mothers too are responsible for certain types of infertility in men. Thus far, onlyfathers have been held responsible for infertility in the male offspring. This is so because it is the father who transmits the Y or male sex-determining chromosome tothe son and the mother does not transmit any male sex chromosome to the male child.But a study, by the Hyderabad-based Centre for Cellular and Molecular Biology, on Indian men from different linguistic and geographical backgrounds shows that motherstoo play a key role in transferring the infertility genes to sons. Mothers, however,do not themselves get affected by these infertility genes.

The CCMB study revealed that mitochondrial DNA, which is inherited by sons frommothers, is contributing to increasing male infertility around the world,particularly in men from the Indian sub-continent. The mitochondrial or mDNA is found to be undergoing mutations affecting the motility of sperm as well as itscount."Sperm quality is also greatly influenced by mutations in the components of therespiratory chain of the mitochondrial DNA. Although mDNA has been studied extensively for the past two decades, very few studies have investigated theinvolvement of mDNA mutations in male infertility. There are 37 genes in mDNA,encoding 13 proteins, which are essential components of respiratory-chain complexes involved in the production of adenosine triphosphate," says Dr Kumarasamy Thangarajof Evolutionary and Medical Genetics Laboratory of the Centre for Cellular andMolecular Biology.As part of the study, the CCMB team analysed the mitochondrial DNA of 34 men suffering from oligoasthenozoospermia (low sperm count with poor motility) alongwith 150 normozoospermic (fertile) men. The team noticed a novel missense mutationin ND4 gene. A missense is a mutation that converts a codon coding for one amino acid to a codon coding for another amino acid. In the case of oligoasthenozoospermicmen, the mutation in the ND4 gene replaced threonine with isoleucine. But this wasnot observed in normozoospermic or fertile men who served as a control group for purpose of the study.Dr Thangaraj points out that abnormal semen is one of the major factors that isassociated with male infertility. The quality and quantity of sperm production maybe affected greatly by both environmental and genetic factors.

Karyotypic (chromosomal) abnormalities and Y-chromosomal microdeletions are the most frequentgenetic abnormalities associated with abnormal semen profile, particularlyoligozoospemia (less than 20 million sperm per ml but still a measurable level) nonobstructive azoospermia (a condition with complete lack of measurable sperm).Explaining how the mitochondrial DNA from mothers is responsible for infertility insons, he says spermatozoa are heavily dependent on mitochondria for respiratory energy for motility. The mature mammalian spermatozoon contains about 72 to 80mitochondria in the mitochondrial sheath of the midpiece (area below the sperm headwhich serves as a motor of the sperm).Analysis of blood samples from both oligoasthenozoospermic (infertile) and normozoospermic (fertile) control men revealed the presence of several sequence variants but one variant at nucleotide position was found to be present in all 10samples. Interestingly the T allele (C11994T) never before has been reported, either as a polymorphism or in association with a disease, anywhere in the world."We screened for the presence of this mutation in the remaining 24 samples.Amazingly, we also found this mutation in all the remaining 24 samples, although none of the 150 proven-fertile (normozoospermic) men carried it. The C11994Tmutation is located in the second base of a codon, resulting in an amino-acid changefrom threonine to isoleucine at amino-acid position 412 of the ND4 gene. The ND4 gene is an essential subunit of complex I of the mitochondrial respiratory chain,and ND4 mutations have been implicated in mitochondrial diseases such as Leigh'ssyndrome and Leber hereditary optic neuropathy," he observed.

Because none of the fertile men analysed in this study or in other studies aroundthe world has been found to contain this C11994T mutation, the possibility of itbeing a neutral polymorphism was ruled out by the CCMB team.

"There is interesting evidence that mDNA variation is an important contributor tothe motility variation of sperm. Mutations of mDNA have been well documented inseveral disorders, either independently or in association with nuclear mutations," Dr Thangaraj says.

Source : greatandhra