Cholesterol Degrading Bacteria from Cow’s Milk

Screening of the Cholesterol Degrading Bacteria from Cow’s Milk

Accumulation of cholesterol may lead to the risk of severe heart disease. To prevent cardiac complications; various chemo-mendicants are available but may pose a risk of side effects on the human body. Therapy that could decrease the cholesterol without any side effect is therefore needed. Recently, microbial cholesterol degrading enzymes have been exploited for serum cholesterol detection. Hence, with the view to generate pro-biotic-based cholesterol decreasing technology an attempt has been made to isolate cholesterol degrading bacteria from cow’s milk. Total of 11 bacterial isolates exhibited cholesterol degrading activity with cholesterol-lowering potentials ranging from 42.88 – 97.20 %.

Isolation of cholesterol degrading bacteria from cow’s milk:-

Thirty-two fresh, raw cow milk samples were collected from fifteen farms in the Washim area, Maharashtra, India. Samples were incubated at 37°C until coagulation. The coagulated samples were then activated in MRS broth at 37°C for 24h in order to obtain enriched cultures. Enriched cultures were further streaked on an MRS agar medium and incubated under anaerobic condition using a candle extinction jar with a moistened filter paper to provide a CO2- enriched, water-vapor saturated atmosphere at 37° for 48 hours. Single colonies picked off the plates were subcultured in MRS broth at 37°C for 24 hours. The Received: 25 March 2013 Accepted: 27 April 2013 Online: 01 May 2013 cultures were examined microscopically and specifically Gram-positive rod-shaped bacteria were restreaked on MRS agar medium for purification The isolated Lactobacillus species were transferred from MRS medium to cholesterol agar (0.1 %) and incubated at 30° C for 12 hrs. The ability of the isolated bacteria to decompose cholesterol was evaluated by measuring the zone of translucency around colonies on agarized medium containing cholesterol as a sole carbon source. The developed colonies were further enriched in cholesterol broth and incubated at 30° C for 24 hrs. The enriched culture was homogenized to obtain cell free extract and was centrifuged at 7000 rpm for 10 minutes. The supernatant thus obtained was taken as a crude source of an enzyme cholesterol oxidase.

Xgeva for rare, non-malignant tumor

The tumor usually affects adults between ages 20 and 40, although it may also develop in adolescents, the FDA said Thursday in a news release. It typically doesn't spread, although in rare cases it can become cancerous and travel to the lungs.
As a non-cancerous tumor, GCTB destroys bone as it becomes larger, causing pain, fractures and loss of mobility. Xgeva has been approved in cases where the tumor can't be surgically removed, or might lead to a severe outcome such as loss of a limb, the agency said.
Xgeva, approved under the FDA's expedited review program, was evaluated for this use in two clinical trials involving a total of 305 adults and adolescents. Common side effects included joint pain, headache, nausea, fatigue, back pain and extremity pain.
Women of childbearing potential should use "highly effective" contraception while taking Xgeva, since the drug can harm a fetus, the FDA warned.
The drug was first approved in 2010 to prevent fractures when cancer has spread to the bone. It's marketed by Amgen, based in Thousand Oaks, Calif.

Mosquitoes' Sense Of Smell Altered

In one of the first successful attempts at genetically engineering mosquitoes, Howard Hughes Medical Institute (HHMI) researchers have altered the way the insects respond to odors, including the smell of humans and the insect repellant DEET. The research not only demonstrates that mosquitoes can be genetically manipulated using the latest research techniques, but paves the way to understanding why the insect is so attracted to humans, and how to block that attraction. 

In 2007, scientists announced the completion of the full genome sequence of Aedes aegypti, the mosquito that transmits dengue and yellow fever. A year later, when Vosshall became an HHMI investigator, she shifted the focus of her lab from Drosophila flies to mosquitoes with the specific goal of genetically engineering the insects. Studying mosquitoes appealed to her because of their importance as disease carriers, as well as their unique attraction to humans.  

Vosshall's first target: a gene called orco, which her lab had deleted in genetically engineered flies 10 years earlier. 

"We knew this gene was important for flies to be able to respond to the odors they respond to," says Vosshall. "And we had some hints that mosquitoes interact with smells in their environment, so it was a good bet that something would interact with orco in mosquitoes."

Vosshall's team turned to a genetic engineering tool called zinc-finger nucleases to specifically mutate the orco gene in Aedes aegypti. They injected the targeted zinc-finger nucleases into mosquito embryos, waited for them to mature, identified mutant individuals, and generated mutant strains that allowed them to study the role of orco in mosquito biology. The engineered mosquitoes showed diminished activity in neurons linked to odor-sensing. Then, behavioral tests revealed more changes.

When given a choice between a human and any other animal, normal Aedes aegypti will reliably buzz toward the human. But the mosquitoes with orco mutations showed reduced preference for the smell of humans over guinea pigs, even in the presence of carbon dioxide, which is thought to help mosquitoes respond to human scent. "By disrupting a single gene, we can fundamentally confuse the mosquito from its task of seeking humans," says Vosshall. But they don't yet know whether the confusion stems from an inability to sense a "bad" smell coming from the guinea pig, a "good" smell from the human, or both

Next, the team tested whether the mosquitoes with orco mutations responded differently to DEET. When exposed to two human arms—one slathered in a solution containing 10 percent DEET, the active ingredient in many bug repellants, and the other untreated—the mosquitoes flew equally toward both arms, suggesting they couldn't smell the DEET. But once they landed on the arms, they quickly flew away from the DEET-covered one. "This tells us that there are two totally different mechanisms that mosquitoes are using to sense DEET," explains Vosshall. "One is what's happening in the air, and the other only comes into action when the mosquito is touching the skin." Such dual mechanisms had been discussed but had never been shown before. 

Vosshall and her collaborators next want to study in more detail how the orco protein interacts with the mosquitoes' odorant receptors to allow the insects to sense smells. "We want to know what it is about these mosquitoes that makes them so specialized for humans," she says. "And if we can also provide insights into how existing repellants are working, then we can start having some ideas about what a next-generation repellant would look like."

Stem cell surprises

Scientists are discovering many new sources of stem cells for research. Here are some of the more surprising:

BRAIN CELLS FROM URINE:

Cells from the lining of the kidney are routinely shed in urine. Scientists at China's Guangzhou Institutes of Bio-medicine and Health and their colleagues recently used a special brew of transcription factors to reprogram these cells into neural progenitor cells. They went on to successfully derive human brain cells that could survive in newborn rat brains.

3-D PRINTED STEM CELLS:

3-D printers lay down thin layers of material much like ordinary printers, except they deposit layer upon layer to create 3-D objects. A team of researchers at Heriot-Watt University and Roslin Cellab in Scotland recently showed they could print using inks containing human embryonic stem cells, which stayed alive after printing and could develop into different types of cells. Bio-engineers are exploring 3-D printing as a way of creating tissues and organs for transplant.

STEM CELLS FROM CADAVERS:

Last year, researchers at the Pasteur Institute in Paris and colleagues discovered that stem cells can remain alive in human corpses for at least 17 days after death. They kept cadavers at 4C to avoid decomposition and these stem cells, which normally give rise to skeletal muscle, survived without oxygen. The cells had extraordinarily reduced metabolic activity when discovered, marking the first time scientists have found that stem cells were capable of such dormancy. Another team of scientists at NIH and the Lieber Institute for Brain Development in Baltimore discovered that living cells from the scalps and brain linings of human corpses could be transformed into stem cells. Specifically, fibroblasts, the most common cells of connective tissue in animals, could be collected from cadavers and reprogrammed into induced pluripotent stem cells, which could then develop into a multitude of cell types, including neurons