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Comment by Dr. Krishna Kumari Challa on April 26, 2015 at 11:55am

Comment by Dr. Krishna Kumari Challa on April 25, 2015 at 8:20am

Mitochondrial diseases are maternally inherited genetic disorders that cause a wide spectrum of debilitating conditions and which currently have no cure. In a study published April 23 in the journal Cell, Salk Institute researchers report the first successful attempt using gene-editing technology to prevent mutated mitochondrial DNA associated with multiple human mitochondrial diseases from being passed from mothers to offspring in mice.

"This technique is based on a single injection of mRNA into a mother's oocytes or early embryos and therefore could be easily implemented in IVF [in vitro fertilization] clinics throughout the world," said senior study author Juan Carlos Izpisua Belmonte of the Salk Institute for Biological Studies. "Since mutations in mitochondrial DNA have also been implicated in neurodegenerative disorders, cancer, and aging, our technology could potentially have broad clinical implications for preventing the transmission of disease-causing mutations to future generations."

Mitochondria are known as the powerhouse of the cell because they generate most of the cell's supply of energy. Each cell in the body contains anywhere from 1,000 to 100,000 copies of mitochondrial DNA, which is exclusively transmitted through maternal inheritance. In most patients with mitochondrial disease, mutated and normal mitochondrial DNA molecules are mixed together in cells. A high percentage of mutated mitochondrial DNA can lead to the degeneration and catastrophic failure of various organs, resulting in serious health problems such as seizures, dementia, diabetes, heart failure, liver dysfunction, vision loss, and deafness.
In the new study, Belmonte and his team demonstrated the therapeutic promise of an alternative approach that allows the direct correction of the mutated DNA in mitochondria by using DNA-cutting enzymes called restriction endonucleases and TALENs. This gene-editing approach might be safer, simpler, and more ethical than mitochondrial replacement therapy because it does not require donor eggs. The enzymes are designed to target a specific mutated DNA sequence and introduce a precise cut that destroys the mutated mitochondrial DNA while leaving the normal mitochondrial DNA intact, thereby shifting the balance toward a healthy genetic state in mitochondria.
''Selective Elimination of Mitochondrial Mutations in the Germline by Genome Editing''
http://www.cell.com/cell/abstract/S0092-8674%2815%2900371-2?_return...

Comment by Dr. Krishna Kumari Challa on April 25, 2015 at 7:26am

The Lancet: Scientists announce final trial results of the world's most advanced malaria vaccine
The first malaria vaccine candidate (RTS,S/AS01) to reach phase 3 clinical testing is partially effective against clinical disease in young African children up to 4 years after vaccination, according to final trial data, published in The Lancet. The results suggest that the vaccine could prevent a substantial number of cases of clinical malaria, especially in areas of high transmission. The findings reveal that vaccine efficacy against clinical and severe malaria was better in children than in young infants, but waned over time in both groups. However, protection was prolonged by a booster dose, increasing the average number of cases prevented in both children and young infants.
In children who received 3 doses of RTS,S/AS01 plus a booster, the number of clinical episodes of malaria at 4 years was reduced by just over a third (36%). This is a drop in efficacy from the 50% protection against malaria seen in the first year.

Importantly, without a booster dose, significant efficacy against severe malaria was not shown in this age group. However, in children given a booster dose, overall protective efficacy against severe malaria was 32%, and 35% against malaria-associated hospitalisations.

In infants who received 3 doses of RTS,S/AS01 plus a booster, the vaccine reduced the risk of clinical episodes of malaria by 26% over 3 years follow-up. There was no significant protection against severe disease in infants.
- The Lancet

Comment by Dr. Krishna Kumari Challa on April 25, 2015 at 7:13am

Labs are not boring places.  Apart from searching for and spreading knowledge they have aesthetic values too! See for yourself :

http://gizmodo.com/these-are-the-most-beautiful-science-labs-in-the...

Comment by Dr. Krishna Kumari Challa on April 24, 2015 at 9:57am

Heritability of Attractiveness to Mosquitoes
Abstract

Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. Body odour can be controlled genetically but the existence of a genetic basis for differential attraction to insects has never been formally demonstrated. This study investigated heritability of attractiveness to mosquitoes by evaluating the response of Aedes aegypti (=Stegomyia aegypti) mosquitoes to odours from the hands of identical and non-identical twins in a dual-choice assay. Volatiles from individuals in an identical twin pair showed a high correlation in attractiveness to mosquitoes, while non-identical twin pairs showed a significantly lower correlation. Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124) for relative attraction and 0.67 (0.354) for flight activity based on the average of ten measurements. The results demonstrate an underlying genetic component detectable by mosquitoes through olfaction. Understanding the genetic basis for attractiveness could create a more informed approach to repellent development.
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.01...

Comment by Dr. Krishna Kumari Challa on April 24, 2015 at 9:50am

Asthma's potential root cause has been identified...
A team of scientists have for the first time identified the potential root cause of asthma and an existing drug that offers a new treatment. Published in Science Translational Medicine, Cardiff University researchers, working in collaboration with scientists at King’s College London and the Mayo Clinic (USA), describe the previously unproven role of the calcium sensing receptor (CaSR) in causing asthma, a disease which affects 300 million people worldwide.

The team, which includes Professor Christopher Corrigan and Professor Jeremy Ward from the Division of Asthma, Allergy and Lung Biology at King’s College London, used mouse models of asthma and human airway tissue from asthmatic and non-asthmatic people to reach their findings.

Crucially, the paper highlights the effectiveness of a class of drugs known as calcilytics in manipulating CaSR to reverse all symptoms associated with the condition. These symptoms include airway narrowing, airway twitchiness and inflammation - all of which contribute to increased breathing difficulty. For the first time researchers have found a link airways inflammation, which can be caused by environmental triggers - such as allergens, cigarette smoke and car fumes – and airways twitchiness in allergic asthma.
The research paper shows how these triggers release chemicals that activate CaSR in airway tissue and drive asthma symptoms like airway twitchiness, inflammation, and narrowing. Using calcilytics, nebulized directly into the lungs, and show that it is possible to deactivate CaSR and prevent all of these symptoms.
The identification of CaSR in airway tissue means that the potential for treatment of other inflammatory lung diseases beyond asthma is immense. These include chronic obstructive pulmonary disease (COPD) and chronic bronchitis, for which currently there exists no cure. It is predicted that by 2020 these diseases will be the third biggest killers worldwide.

The team is now seeking funding to determine the efficacy of calcilytic drugs in treating asthmas that are especially difficult to treat, particularly steroid-resistant and influenza-exacerbated asthma, and to test these drugs in patients with asthma.
Calcilytics were first developed for the treatment of osteoporosis around 15 years ago with the aim of strengthening deteriorating bone by targeting CaSR to induce the release of an anabolic hormone. Although clinically safe and well tolerated in people, calcilytics proved unsuccessful in treating osteoporosis.

But this latest breakthrough has provided researchers with the unique opportunity to re-purpose these drugs, potentially accelerating the time it takes for them to be approved for use asthma patients. Once funding has been secured, the group aim to be trialling the drugs on humans within two years.
- King's College London

Comment by Dr. Krishna Kumari Challa on April 23, 2015 at 8:15am

Social exchange can amplify subjective fears and risk perception...
New findings by scientists at the Max Planck Institute for Human Development and the University of Konstanz show that subjective fears about potential risks may be amplified in social exchange. Their findings have now been published in the journal Proceedings of the National Academy of Sciences of the USA .
Scientists at the Max Planck Institute for Human Development and the University of Konstanz studied 10-person communication chains in the laboratory. In an experiment based on a “pass the message” game, they examined how risk information is transmitted from one person to the next, and how this process influences risk perception. The results show not only that information is often gradually lost or distorted, but that new information can be spontaneously created. “The participants’ messages became shorter, less accurate, and increasingly dissimilar,“ says Mehdi Moussaïd, lead author of the study and researcher at the Max Planck Institute for Human Development in Berlin.
The authors of the study found that participants’ preconceptions affected the information transmitted, and in turn influenced the perceptions of those receiving the information. The subjective view of the communicator was thus amplified. “People tend to single out the information that fits their preconceptions, and communicates primarily that information to the next person,“ says Henry Brighton, co-author of the study and researcher at the Max Planck Institute for Human Development. This can lead to preconceptions being reinforced, so that the original message eventually has a negligible impact on the receiver’s judgments, and leads to an increasingly alarmist perception of potential risks.
The results of this study provide insights into the public response to risk and the formation of often unnecessary fears and anxieties. The researchers emphasize the socio-political importance of the realistic assessment of potential dangers. To combat the social amplification of risk, they call for the open, transparent communication of scientific evidence. “Without scaremongering, but also without giving people a false sense of security or an illusion of certainty,“ says co-author Wolfgang Gaissmaier, Professor of Social Psychology and Decision Sciences at the University of Konstanz.
"The amplification of risk in experimental diffusion chains"
http://www.pnas.org/content/early/2015/04/14/1421883112

Comment by Dr. Krishna Kumari Challa on April 23, 2015 at 6:49am

Forensic geo-science:
http://www.nature.com/news/forensic-science-the-soil-sleuth-1.17373

Comment by Dr. Krishna Kumari Challa on April 22, 2015 at 6:17am

How to avoid pet-associated (zoonotic infections) diseases:

We all love pets. However, we can get a few diseases from them too - especially those who are more vulnerable like young children, older people and people with weak immune systems because of various diseases are at higher risk.

Disease can be transmitted to people by all kinds of pets. Examples of the types of pathogens that can be transmitted include Salmonella, multidrug resistant bacteria (including Clostridium difficile) and Campylobacter jejuni, as well as parasites such as hookworm, roundworm and Toxoplasma. Routes of transmission include bites, scratches and contact with faeces and indirect transmission via infected surfaces from reptiles and amphibians.

Relatively simple steps can be taken to reduce risk of infection, including use of gloves when cleaning aquariums, cages and removing faeces, hand washing after contact with pets and their living and feeding areas, keeping living, sleeping and feeding areas clean and disinfected, keeping litter boxes away from human food preparation and consumption areas, discouraging face-licking, avoidance of contact with exotic animals, taking pets for regular veterinary checks and holding off on acquiring new pets until immune status of a vulnerable person has improved.

http://www.cmaj.ca/content/early/2015/04/20/cmaj.141020

Comment by Dr. Krishna Kumari Challa on April 22, 2015 at 6:06am

How the skin fusing works in wound healing ... an interesting observation by scientists

Scientists from the Goethe University Frankfurt, the European Molecular Biology Laboratory Heidelberg and the University of Zurich explain skin fusion at a molecular level and pinpoint the specific molecules that do the job in their latest publication in the journal Nature Cell Biology.

As a first step, as the scientists discovered, cells find their opposing partner by "sniffing" each other out. As a next step, they develop adherens junctions which act like a molecular Velcro. This way they become strongly attached to their opposing partner cell. The biggest revelation of this study was that small tubes in the cell, called microtubules, attach to this molecular Velcro and then deploy a self-catastrophe, which results in the skin being pulled towards the opening, as if one pulls a blanket over.

Damian Brunner who led the team at the University of Zurich has performed many genetic manipulations to identify the correct components. The scientists were astonished to find that microtubules involved in cell-division are the primary scaffold used for zipping, indicating a mechanism conserved during evolution.

"What was also amazing was the tremendous plasticity of the membranes in this process which managed to close the skin opening in a very short space of time. When five to ten cells have found their respective neighbors, the skin already appears normal", says Achilleas Frangakis from the Goethe University Frankfurt, who led the study.

The scientists hope that their results will open new avenues into the understanding of epithelial plasticity and wound healing.

"Quantitative analysis of cytoskeletal reorganization during epithelial tissue sealing by large-volume electron tomography"

http://www.nature.com/ncb/journal/vaop/ncurrent/full/ncb3159.html

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