Showing posts with label diagnostics. Show all posts
Showing posts with label diagnostics. Show all posts

Wednesday, October 4, 2023

Methanethiol: The Scent of Disease and Discovery

In a previous blog post, we discussed the role of SELENBP1 in nonosyndromic (monosymptomatic) halitosis. We learned that if this enzyme isn't functioning correctly, it can lead to the release of more Methanethiol, a volatile and rather unpleasant-smelling gas often associated with the aroma of rotten cabbage. 

However, Selenium binding protein 1 (SELENBP1) isn't just a casual bystander in our biological processes. It has been linked to various health conditions and diseases. These include:

Hypermethioninemia: A rare condition that can sometimes come with learning disabilities and neurological issues.

Schizophrenia: a complex mental disorder that challenges our understanding of the human mind

Hypertension and Ischemic Heart Conditions, conditions such as Guillain-Barré syndrome and Infectious Diseases: Dysregulation of SELENBP1 is associated with Zika virus (ZIKV) and dengue infections, as well as COVID-19.

SELENBP1's role in several types of cancer, including its downregulation at the onset of cancer and upregulation in later stages, is a subject of intense research.

Methanethiol contributes to the distinct scent signature linked to cancer, characterized by a combination of volatile organic compounds (VOCs). Researchers are increasingly exploring this intriguing scent profile as a potential tool for non-invasive early cancer diagnosis.

Methanethiol is a testament to the intricate connections between genetics, metabolism, and disease, reminding us that even the smelliest molecules can lead to groundbreaking discoveries.

Methanethiol also contributes to the distinct scent signature associated with cancer, characterized by a combination of volatile organic compounds (VOCs). This intriguing scent profile is increasingly being explored for non-invasive early cancer diagnosis.

In a recent paper titled "Methanethiol: A Scent Mark of Dysregulated Sulfur Metabolism in Cancer,"  researchers unveiled new findings:

Tumor cells undergo metabolic adaptations to meet increased energy demands and enhance stress resilience. This includes dysregulation of sulfur metabolism and elevated levels of volatile sulfur compounds (VSCs) in cancer patients.

Methanethiol stands out as the predominant cancer-associated VSC and is being considered as a potential biomarker for non-invasive cancer diagnosis.

Within the gut microbiome of colorectal carcinoma (CRC) patients, gut bacteria, particularly methanethiol-producing strains like Fusobacterium nucleatum, are a significant source of exposure to methanethiol.

Selenium-binding protein 1 (SELENBP1) plays a crucial role in the rapid degradation of methanethiol through its methanethiol oxidase (MTO) activity.

Odor-based cancer screening methods, such as sniffer dogs and canine scent detection, even human feedback, have shown great promise in identifying lung and colorectal cancer patients, opening doors to non-invasive detection approaches.

The dysregulation of sulfur metabolism and the potential use of methanethiol as a biomarker, coupled with the innovative odor-based cancer screening methods, offer not just promising but transformative avenues for non-invasive cancer detection and cutting-edge research.


REFERENCE

Philipp TM, Scheller AS, Krafczyk N, Klotz LO, Steinbrenner H. Methanethiol: A Scent Mark of Dysregulated Sulfur Metabolism in Cancer. Antioxidants (Basel). 2023 Sep 19;12(9):1780. doi: 10.3390/antiox12091780. PMID: 37760083; PMCID: PMC10525899.

Sunday, June 12, 2016

Seeing Through the Skin

by AURAMETRIX

REFERENCES


Andreoni G, Standoli CE, & Perego P (2016). Defining Requirements and Related Methods for Designing Sensorized Garments. Sensors (Basel, Switzerland), 16 (6) PMID: 27240361

Gao W, Emaminejad S, Nyein HY, Challa S, Chen K, Peck A, Fahad HM, Ota H, Shiraki H, Kiriya D, Lien DH, Brooks GA, Davis RW, & Javey A (2016). Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis. Nature, 529 (7587), 509-14 PMID: 26819044

Imani S, Bandodkar AJ, Mohan AM, Kumar R, Yu S, Wang J, & Mercier PP (2016). A wearable chemical-electrophysiological hybrid biosensing system for real-time health and fitness monitoring. Nature communications, 7 PMID: 27212140

Lee H, Choi TK, Lee YB, Cho HR, Ghaffari R, Wang L, Choi HJ, Chung TD, Lu N, Hyeon T, Choi SH, & Kim DH (2016). A graphene-based electrochemical device with thermoresponsive microneedles for diabetes monitoring and therapy. Nature nanotechnology, 11 (6), 566-72 PMID: 26999482

Panneer Selvam A, Muthukumar S, Kamakoti V, & Prasad S (2016). A wearable biochemical sensor for monitoring alcohol consumption lifestyle through Ethyl glucuronide (EtG) detection in human sweat. Scientific reports, 6 PMID: 26996103
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Yokota T, Zalar P, Kaltenbrunner M, Jinno H, Matsuhisa N, Kitanosako H, Tachibana Y, Yukita W, Koizumi M, & Someya T (2016). Ultraflexible organic photonic skin. Science advances, 2 (4) PMID: 27152354


Thursday, January 31, 2013

Odors and Infections

Many illnesses are associated with distinct odors. Especially those caused by infectious or opportunistic microbes inside the body or on its surfaces.  Body odor of someone infected with C. difficile, for example, can appear "swampy", Rotavirus gives sharply sweet putrid smell that some people associate with wet dogs. H. pylori can create a range of foul odors, and pseudomonas infections can smell like grapes and bitter almonds

Infections like C. difficile are usually linked to a general imbalance of the intestinal microbiota, often referred to as dysbiosis. This means that the odors could be coming from several microbial species, hence could be different for different individuals. Does it mean odor-based diagnostics will never be enough specific?

Not according to a 2-year-old beagle from Netherland, named Cliff. After just a little over two months of training, the beagle learned to identify the C. diff toxin by sniffing people or their samples. During one test, he was able to identify 25 out of 30 infected patients and 265 of 270 non-infected individuals. He also correctly identified 50 of 50 C. diff positive stool samples and 47 of 50 samples from people that did not have this infection. That's sensitivity of 100% for samples and 83-93% for sniffing the air around the patients, and a specificity of 94-100%! And it took him less than 10 minutes to accurately perform 300 diagnostic tests.  

Dogs already do the dirty work with detecting molds. They can examine an office building with 200 rooms in just 8 hours, a task that would take us several days of measuring  moisture, probably without any result. Electronic noses would be of great help and many years of research are finally being translated into useful technologies - to be integrated with refrigerators and mobile phones. But until we are able to build smart devices to detect odors without labor-intensive dog training, perhaps we could train our own nozzles. Studies have shown we do get better with practice. 


REFERENCES

Bomers MK, van Agtmael MA, Luik H, van Veen MC, Vandenbroucke-Grauls CM, & Smulders YM (2012). Using a dog's superior olfactory sensitivity to identify Clostridium difficile in stools and patients: proof of principle study. BMJ (Clinical research ed.), 345 PMID: 23241268

Poulton J, Tarlow MJ. (1987) Diagnosis of rotavirus gastroenteritis by smell. Arch Dis Child. 1987 Aug;62(8):851-2. PMID: 3662595

Arnaud Tognetti, Megan N Williams, Nathalie Lybert, Mats Lekander, John Axelsson, Mats J Olsson, Humans can detect axillary odor cues of an acute respiratory infection in others, Evolution, Medicine, and Public Health, Volume 11, Issue 1, 2023, Pages 219–228, https://doi.org/10.1093/emph/eoad016