Humidity > Influenza Virus

Photo, James Gathany Photo credits: CDC

Photo, James Gathany
Photo credits: CDC

Each year in the winter influenza or “flu” season rolls around and this sickness runs rampant throughout the country. This virus, and many in general, are quite scary because of how easily they can be spread through the air ie. via coughing. Researchers of the National Institute for Occupational Safety and Health (NIOSH of the CDC) have recently linked higher humidity and transmission particle size to more inactivation of influenza (and less spread).

Influenza is an RNA virus that affects mammals and birds causing a small scale pandemic every year in the United States. Viruses tend to mutate very quickly, therefore, it is hard to find a single band-aid to blanket cure this bug. Most people can spread the virus between -1 and 6 days after showing symptoms. Airborne transmission is most likely when this virus appears since many people are in closed quarters attempting to stay warm at home with others during winter.

To test the rate at which influenza stays infectious in different humidities, researchers set up coughing and breathing test dummies in an isolated room. The sneezing dummy released about 4.5×103 virus/liter of air into the room, where 4.6% of that virus was seen to be infectious upon discharge. Of that, upwards of 77.2% of the virus retained infectivity at lower relative humidity (7-23%), while only 14.6% retained infectivity at higher relative humidity of 43%. As a grounding point, average in home humidity during winter is just above 20%, while summer humidity indoors is just below 60%.

Next, the rate of loss of infectivity was measured comparing low and moderate humidity (20% and 45%). Within 15 minutes, 52% of the virus’ infective ability was lost at 45% humidity compared to 20% humidity.

Together these two showed more virus lost its ability to infect new people/etc. at higher relative humidities.

Finally, transmission particle size was measured to see if it had bearing on influenza’s spread and infection at differing humidities. Three particle sizes were used, <1 µm, 1-4 µm, and >4 µm. At the two extremes, <1 & >4 µm, 94% infectivity was seen as lost in the first 15 minutes after coughing virus into the air. However, the 1-4 µm range of particles only showed 29% decrease in infectivity of the virus after 15 minutes. All sizes did, however, show increased loss of infectious ability with more time passed.

It seems as though humidity has great bearing on the inactivation/spreading ability of the influenza virus. At higher humidities, 45% +, the influenza virus showed very little strength in infecting new hosts. This was doubly true when the particle size they rode on was really small or really big.

The best way to minimize your chance to get influenza each year without getting a flu shot?…move to a state with really high humidity in the winter.

Reference:
John D. Noti, Francoise M. Blachere, Cynthia M. McMillen, William G. Lindsley, Michael L. Kashon, Denzil R. Slaughter, Donald H. Beezhold. High Humidity Leads to Loss of Infectious Influenza Virus from Simulated Coughs. PLoS ONE, 2013.
http://dx.doi.org/10.1371/journal.pone.0057485

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unOC linked to Diabetes relief

GLP-1 effects on different human organs.
Photo credits: Daniel J. Drucker (author of the paper of
DOI: 10.1016/j.cmet.2006.01.004)

Researchers have perhaps found another means by which to manage type 2 diabetes. A group from 九州大学 (Kyushu  University) has shown that addition of uncarboxylated osteocalcin (unOC) stimulates glucagon-like peptide-1 (GLP-1) release and insulin secretion in mice.

GLP-1 is normally released in released into the blood in response to eating, so that insulin can be released and digested glucose can be taken into cells. In those with type-II diabetes, the insulin release pathway is impaired in some way, so insufficient insulin (or no insulin) is produced to promote glucose uptake.

UnOC has shown in previous studies to have an effect on the pancreas directly to stimulate insulin release; therefore, this study wanted to test the indirect effect of unOC on insulin secretion via the GLP-1 pathway.

Using mice, unOC’s effect on GLP-1 secretion was tested. 20 minutes after giving mice unOC orally or intraperitoneally, a maximal rise of 50 pg/mL of serum GLP-1 was seen. However, this significant rise was only seen in mice also given the DPP-IV inhibitor sitgaliptin. This needed to be co-administered because GLP-1 has a very short half life and would breakdown before the effects could be seen.

Extending from this, the insulin levels in mice given unOC were seen as raised as well. With the combination of unOC and sitagliptin, insulin rose (maximally) 0.4 ng/mL. These results were seen administering therapies orally or via intrapineal injection. Administering intravenously gave similar results with significant rises in GLP-1 and insulin sooner (as expected).

This study shows unOC may be a strong therapy for type II diabetes management if given to patients in the pure chemical form, as an additive to food, or the like.

Reference:
Akiko Mizokami, Yu Yasutake, Jing Gao, Miho Matsuda, Ichiro Takahashi, Hiroshi Takeuchi, Masato Hirata. Osteocalcin Induces Release of Glucagon-Like Peptide-1 and Thereby Stimulates Insulin Secretion in Mice. PLoS ONE, 2013.
http://dx.doi.org/10.1371/journal.pone.0057375

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A note from me:

Lately my writings have been sluggishly drawn out and without the wherewithal to inspire (not to mention I’ve been posting suuuuuper late). Because of this, I’m taking a week break from blogging. For those that follow: I’ll see you on March 1st. For those that stumbled upon this today: Hopefully you’ll muse my articles, learn some cool stuff, and come back in a week when I pick up again.

See you all seven mornings from now 🙂

The nose of a mole sheds new light on mammalian touch

Star-nosed mole

Star-nosed mole

Researchers of Vanderbilt and Berkeley of the United States recently dug around the star of the star-nosed mole to see what could be learned about mammalian mechanoreception, sense of touch.

Moles are generally creatures that spend most time underground and therefore have terrible vision. To make up for this they have an excellent sense of touch. The star-nosed mole is classified as an animal with the highest density of touch neurons in one area of any animal on the planet. The star of this creature is where most of the touch receptors are housed. For this reason, this group wanted to test the microbiological and genetic components that make this organ so great for mechanoreception in order to learn about mammalian parallels.

The enhanced tactical acuity of the star led researchers to believe the ability of the mole to detect noxious stimuli of thermal and/or chemical root may be impaired. The enhancement of one sense may come at the expense of another so to speak. This was tested by applying capsaicin to the hind-paw of the mole and mice followed by application to mole nose. The first test elicited a nocifensive response in both mole and mouse, but no behavioral response was seen when applied to mole star.

RNA sequencing revealed a lack of TRPA1 and TRPV1 in the group of neurons immediately associated with the star-nose, but a 10 fold higher detection of these molecules in neurons outside the nose proximity. The aforementioned molecules are associated with nociception, or detection of pain.

Furthermore, 20 fold higher levels of Cnga2 and Cnga4, molecules associated with touch detection, were found in the ganglia associated with the nose (trigeminal ganglia) than found outside the area (dorsal root ganglia). A related ion channel, Fam 38a (Piezo1), was found to be expressed in trigeminal ganglia and dorsal root ganglia. Fam38a was found as a parallel to mouse Piezo1.

The group concluded that genes found to be associated with expression of mechanoreceptor stimuli as well as CNG and Piezo1 ion channels played roles in various aspects of mechano-transduction. Studying animals at the extremes of sensory perception can aid in understanding the senses further. In this case, researchers were guided closer to the answer of “how do humans feel” by a star not in the sky, but on a mole.

Reference:
Kristin A. Gerhold equal contributor,

Maurizio Pellegrino equal contributor,

Makoto Tsunozaki, Takeshi Morita, Duncan B. Leitch, Pamela R. Tsuruda, Rachel B. Brem, Kenneth C. Catania, Diana M. Bautista. The Star-Nosed Mole Reveals Clues to the Molecular Basis of Mammalian Touch. PLoS ONE, 2013

Restoring insulin creation in diabetes type I sufferers

Type I diabetes is very manageable by taking daily doses of exogenous insulin. However, researchers of the University of South Dakota pulled together a method utilizing G-protein coupled receptor 119 (GPR119) and dipeptidylpeptidase-IV (DPP-IV) to regenerate lost ß-islet cells of diabetics and restore insulin production in the body.

ß-cells are the insulin generators of the body, but in type I diabetes patients, they don’t exist or don’t work. GPR119, when activated by an agonist such as PSN632408, stimulates ß-cell replication, increases GLP-1 secretion, reduces food intake, and decreases body weight gain. If hyperstimulated in type I diabetes sufferers the level of insulin reached would be closer to that of normal body levels, which is why this was a target of this study. Contrarily, DPP-IV works to degrade or breakdown GLP-1, which is a protein that stimulates insulin release from ß-cells, enhances ß-cell proliferation, and prevents ß-cell programmed cell death.

In the study, diabetic mice with blood glucose levels of 400 to 500 mg/dL were treated with PSN632408 and/or sitagliptin for 7 weeks. The former acted as a GPR119 agonist and the latter as a DPP-IV inhibitor. After treatment ended, the three different treatment groups obtained the following percentages of normoglycemia (blood glucose < 200 mg/dL) mice:

– PSN632408, 32% mice with normoglycemia
– Sitagliptin, 36% mice with normoglycemia
– PSN632408 & sitagliptin, 59% mice with normoglycemia

The average drop in blood glucose was 257 mg/dL after seven weeks. The treatment actively reversed type I diabetes in these mice.

Further tests showed increased levels of GLP-1 (7.6±0.4 pmol/L in control mice, 14.8±1.0, 35.9±8.6, 44.2±10.5 pmol/L in mice treated with PSN632408, Sitagliptin, or both respectively), ß-cell replication, and ß-cell regeneration.

Mice treated with a GRP119 agonist and DPP-IV inhibitor showed increased ß-cell regeneration and overall insulin production. As mice have similar GRP119/DPP-IV pathways to humans, these results are very exciting for the diabetes scene.

Drinking (or painfully auto-injecting) daily insulin may no longer be necessary for diabetics if the GRP119 agonist/DPP-IV inhibitor treatment is approved for clinical use.

Reference:
Ansarullah, Yan Lu, Martha Holstein, Brittany DeRuyter, Alex Rabinovitch, Zhiguang Guo. Stimulating β-Cell Regeneration by Combining a GPR119 Agonist with a DPP-IV Inhibitor. PLoS ONE, 2013. http://dx.doi.org/10.1371/journal.pone.0053345