Lactate biosensor could become…

… a simple test for CFS?

Credit: American Chemical Society. 

Saw this interesting article today. Since lactic acid and lactate is the prime substances that makes muscle feel exhausted and sour, may be this technique could become and easy way to test for CSF.

First human tests of new biosensor that warns when athletes are about to 'hit the wall'

Wednesday, 24 July 2013

A new biosensor, applied to the human skin like a temporary tattoo, can alert marathoners, competitive bikers and other "extreme" athletes that they're about to "bonk," or "hit the wall," scientists are reporting. The study, in ACS' journal Analytical Chemistry, describes the first human tests of the sensor, which also could help soldiers and others who engage in intense exercise — and their trainers — monitor stamina and fitness.

Joseph Wang and colleagues explain that the sensor monitors lactate, a form of lactic acid released in sweat. Lactate forms when the muscles need more energy than the body can supply from the "aerobic" respiration that suffices during mild exercise. The body shifts to "anaerobic" metabolism, producing lactic acid and lactate. That helps for a while, but lactate builds up in the body, causing extreme fatigue and the infamous "bonking out," where an athlete just cannot continue. Current methods of measuring lactate are cumbersome, require blood samples or do not give instant results. Wang's team sought to develop a better approach.

They describe the first human tests of a lactate sensor applied to the skin like a temporary tattoo that stays on and flexes with body movements. Tests on 10 human volunteers showed that the sensor accurately measured lactate levels in sweat during exercise.

"Such skin-worn metabolite biosensors could lead to useful insights into physical performance and overall physiological status, hence offering considerable promise for diverse sport, military, and biomedical applications," say the scientists.

Future research will further correlate sweat lactate levels with fitness, performance and blood lactate levels, Wang added.

Reference:

Electrochemical Tattoo Biosensors for Real-Time Noninvasive Lactate Monitoring in Human Perspiration

Wenzhao Jia, Amay J. Bandodkar, Gabriela Valdés-Ramírez, Joshua R. Windmiller, Zhanjun Yang, Julian Ramírez, Garrett Chan, and Joseph Wang 

Anal. Chem., 2013, 85 (14), pp 6553–6560, DOI: 10.1021/ac401573r

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ZenMaster

Finally a verdict…

… on XMRV and pMLV and CFS/ME.

In an extensive study funded by National Institutes of Health and with many expert groups participating, the conclusion is that the original study by Dr. Mikovits that XMRV or similar viruses is a cause of CFS, is WRONG. No such links can be found.

In a statement from Dr. Mikovits, the author of the Science paper wherein XMRV was first linked to CFS, she said:

"I greatly appreciated the opportunity to fully participate in this unprecedented study. Unprecedented because of the level of collaboration, the integrity of the investigators, and the commitment of the NIH to provide its considerable resources to the CFS community for this important study. Although I am disappointed that we found no association of XMRV/pMLV to CFS, the silver lining is that our 2009 Science report resulted in global awareness of this crippling disease and has sparked new interest in CFS research. I am dedicated to continuing to work with leaders in the field of pathogen discovery in the effort to determine the etiologic agent for CFS."

"Although the once promising XMRV and pMLV hypotheses have been excluded, the consequences of the early reports linking these viruses to disease are that new resources and investigators have been recruited to address the challenge of the CFS/ME", said W. Ian Lipkin, MD, director of the multi-site study and John Snow Professor of Epidemiology in the Mailman School of Public Health of Columbia University.

"We are confident that these investments will yield insights into the causes, prevention and treatment of CFS/ME."

Research on the causes of CFS/ME will continue, says Lipkin.

"We've tested the XMRV/pMLV hypothesis and found it wanting," he says.

But, he says, "we are not abandoning the patients. We are not abandoning the science. The controversy brought a new focus that will drive efforts to understand CFS/ME and lead to improvements in diagnosis, prevention and treatment of this syndrome."

References:

Chronic Fatigue Syndrome is Not Linked to Suspect Viruses

Multi-site blinded study puts to rest the notion that these viruses cause the mysterious ailment

EurekAlert! - Tuesday, 18 September 2012

Viruses Not to Blame for Chronic Fatigue Syndrome After All

EurekAlert! - Tuesday, 18 September 2012

ZenMaster

A second study,…

… published Monday by the Proceedings of the National Academy of Sciences, confirm the presence of XMRV and other MRV-related viruses in a high proportion of chronic fatigue syndrome patients. Scientists found gene sequences from several MRV-related viruses in blood cells from 32 out of 37 chronic-fatigue patients but only 3 of 44 healthy ones.

Chronic Fatigue Linked to Virus Class
New York Times - 23 August 2010
When the journal Science published an attention-grabbing study last fall linking chronic fatigue syndrome to a recently discovered retrovirus, many experts remained skeptical — especially after four other studies found no such association.

Reference:

Detection of MLV-related virus gene sequences in blood of patients with chronic fatigue syndrome and healthy blood donors
Shyh-Ching Lo, Natalia Pripuzova, Bingjie Li, Anthony L. Komaroff, Guo-Chiuan Hung, Richard Wang, and Harvey J. Alter
PNAS published ahead of print August 23, 2010, doi:10.1073/pnas.1006901107


ZenMaster