Heart disease patients who eat one grapefruit daily can significantly reduce the levels of cholesterol in their blood in comparison to patients who do not eat the fruit, a new study has found. Chronic high blood cholesterol is a major risk factor for heart disease.

Dr. Shela Gorinstein at a citrus fruit stand in the Mahane Yehuda outdoor market in Jerusalem. (Photo by Sasson Tiram)

The study was conducted by a group of scientists under the leadership of Dr. Shela Gorinstein of the Hebrew University School of Pharmacy, Department of Medicinal Chemistry and Natural Products, in cooperation with Prof. Abraham Caspi, head of the Institute of Cardiology at Kaplan Hospital in Rehovot. In addition, scientists from Poland and Singapore participated in laboratory work connected with the project.

The study, which strengthens a growing body of evidence supporting the heart benefits of eating citrus fruit, was published this month on the website of the American Chemical Society’s Journal of Agricultural and Food Chemistry. The study will appear in the journal’s March 22 print issue.

February has been designated in the U.S. as American Heart Month. In the U.S., heart disease is the number one killer of women.

The grapefruit study included 57 patients at Kaplan Hospital, both men and women, with hyperlipidemia (high blood cholesterol) who recently had coronary bypass surgery and did not take statin drugs during the study period. Statins are commonly prescribed to lower cholesterol.

(1) Comments posted about this in the forum

This illustration compares the size of a gargantuan star and its surrounding dusty disk (top) to that of our solar system.

The discovery was made through NASA's Spitzer Space Telescope observations of two hypergiant stars in the Large Magellanic Cloud--the Milky Way's nearest neighboring galaxy--by a team led by Joel Kastner, a professor at Rochester Institute of Technology's Chester F. Carlson Center for Imaging Science. His team's findings will appear in the Feb. 10 issue of Astrophysical Journal Letters.

So far, searches for planets outside the solar system have been restricted to sun-like stars. All of these stars are older, dimmer and cooler objects than hypergiants, which are extraordinarily large and luminous but shorter-lived by billions of years.

Kastner and his team used infrared spectra obtained by Spitzer to study a population of dying stars. They added a new direction to their project when Spitzer's infrared spectrograph revealed unexpected information. Spitzer's sensitive spectrometer, which breaks down infrared radiation into component wavelengths as a prism splits visible light into a rainbow, indicated that a third of the stars in the population thought to be in decline--including two massive and exceedingly luminous hypergiants--were actually younger stars in varying stages of development.

The curious spectra of these two hypergiants (R126 and R66)--with one star being 70 times bigger than the sun--led Kastner to reexamine the stars' classifications as dying. The shape of the spectra, or the amount of light from different wavelengths, is characteristic of flattened disks of dust orbiting the stars.

The two stars' similar spectra differ in detail, with one encircled by dust in crystalline form, the other by more shapeless, amorphous dust grains. This expands the range of known conditions under which complex dust grains and molecules can form and persist around stars, Kastner says.

(2) Comments posted about this in the forum

Female embryonic stem cells differentiated for 2 days. Red: X-chromosomes, green: X-inactivation centers (Xics)

Forty-five years ago, British scientist Mary Lyon already described this chromosome inactivation typical of female cells. Lyon proposed a hypothesis: With two copies of the X chromosome, all X-linked genes are present in two copies. However, in a male organism, which is equipped with a set of one X and one Y chromosome, the X genes are present in only one copy in each cell. To restore genetic balance, a female cell inactivates one of its two X chromosomes.

During development of a female embryo, inactivation of either of the X chromosomes, the one inherited from the father or the one inherited from the mother, occurs at random. To coordinate inactivation, the cell first needs to determine whether it contains more than one X chromosome and then make a choice which of the two to switch off. Since the mid-1980s it has been known that a specific region of the X chromosome termed X inactivation center (Xic) is crucial for a correct inactivation process.

Professor Dr. Roland Eils, who leads the bioinformatics departments at the German Cancer Research Center and at the Institute of Pharmacy and Molecular Biotechnology of Heidelberg University, suspected that the spatial arrangement of the Xics within the nucleus is key to inactivation. Working together with colleagues of the Curie Institute, Paris, he searched different cells for distinctive features in the distribution of Xic regions. The scientists compared developing female embryonic stem cells of mice just before X inactivation, with mouse cells in which X inactivation had already taken place. Using a 3-dimensional visualization of fluorescent labels of the Xic regions, they observed that the Xics of both X chromosomes in the developing stem cells were located very close to each other in up to 15 percent of cells. In the comparative cell line, this was found in only about three percent of cells, which constitutes a random result. The formation of pairs (co-localization) was particularly noticeable in the stem cells after about one and a half days of development, i.e. shortly before X inactivation.

(1) Comments posted about this in the forum