Watch: Bill Nye Uses Science To Defend Women’s Reproductive Rights

Neurotransmitters are chemicals that help in transmitting signals across a synapse. Different neurotransmitters are associated with different functions. Knowledge about these helps us to treat various neurological conditions by either stimulating or inhibiting these production. #neurology #neuroscience #psychiatry #medicine #medstudynotes #medschool #mbbs #unimed #brain #nervoussystem #physiology #medblog #medblr #medstudent https://www.instagram.com/p/BrM4ocsBqJe/?utm_source=ig_tumblr_share&igshid=12tojib83c32d

Marrow Christmas and a Happy New Smear!

A very seasonal smear made from red marrow extracted from the iliac crest of a donor’s pelvis prior to transplantation.

Happy Holidays everyone

i♡histo

The image amazingly captures a single moment in time during the development of thousands of red and white blood cells.

Many of the small cells that are visible, like the ones forming the snowman’s carrot nose, do not have a nucleus. These are brand new erythrocytes (red blood cells) that are ready to exit the bone and enter the blood stream.

The other, slightly larger cells that have nuclei, like the snowman’s eyes and his top button, are either precursors to these erythrocytes (they will mature and lose their nucleus) or are precursors to the other blood cells in our body, the leukocytes (white blood cells): lymphocytes, monocytes, neutrophils, eosinophils and basophils.

In addition, the bone marrow is home to the cells that form platelets. These are huge multinucleated cells aptly named megakaryocytes - perhaps the cell at the bottom right.

It is possible to identify each mature cell and its precursor based upon its morphology and staining at higher magnification. High or low levels of these cells can indicate disease or cancers of the blood.

NASA’s Juno Spacecraft Completes Flyby over Jupiter’s Great Red Spot

NASA’s Juno mission completed a close flyby of Jupiter and its Great Red Spot on July 10, during its sixth science orbit.

All of Juno’s science instruments and the spacecraft’s JunoCam were operating during the flyby, collecting data that are now being returned to Earth. Juno’s next close flyby of Jupiter will occur on Sept. 1.

Raw images from the spacecraft’s latest flyby will be posted in coming days.

“For generations people from all over the world and all walks of life have marveled over the Great Red Spot,” said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. “Now we are finally going to see what this storm looks like up close and personal.”

The Great Red Spot is a 10,000-mile-wide (16,000-kilometer-wide) storm that has been monitored since 1830 and has possibly existed for more than 350 years. In modern times, the Great Red Spot has appeared to be shrinking.

Juno reached perijove (the point at which an orbit comes closest to Jupiter’s center) on July 10 at 6:55 p.m. PDT (9:55 p.m. EDT). At the time of perijove, Juno was about 2,200 miles (3,500 kilometers) above the planet’s cloud tops. Eleven minutes and 33 seconds later, Juno had covered another 24,713 miles (39,771 kilometers), and was passing directly above the coiling crimson cloud tops of the Great Red Spot.

The spacecraft passed about 5,600 miles (9,000 kilometers) above the clouds of this iconic feature.

On July 4 at 7:30 p.m. PDT (10:30 p.m. EDT), Juno logged exactly one year in Jupiter orbit, marking 71 million miles (114.5 million kilometers) of travel around the giant planet.

Juno launched on Aug. 5, 2011, from Cape Canaveral, Florida. During its mission of exploration, Juno soars low over the planet’s cloud tops – as close as about 2,100 miles (3,400 kilometers). During these flybys, Juno is probing beneath the obscuring cloud cover of Jupiter and studying its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.

Early science results from NASA’s Juno mission portray the largest planet in our solar system as a turbulent world, with an intriguingly complex interior structure, energetic polar aurora, and huge polar cyclones.

JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate.

Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of Caltech in Pasadena

Solidification of liquid Gallium 

Gallium is a chemical element with symbol Ga and atomic number 31. Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures, and melts at 29.76 °C (85.57 °F) (slightly above room temperature). Elemental gallium is not found in nature, but it is easily obtained by smelting.

Gallium metal expands by 3.1% when it solidifies, and therefore storage in either glass or metal containers are avoided, due to the possibility of container rupture with freezing. Gallium shares the higher-density liquid state with only a few materials, like water, silicon,germanium, bismuth, and plutonium.

Giffed by: rudescience  From: This video

The film “Hidden Figures,” based on the book by Margot Lee Shetterly, focuses on the stories of Katherine Johnson (left, after receiving the Medal of Freedom in 2015), Mary Jackson and Dorothy Vaughan, African-American women who were essential to the success of early spaceflight. Today, NASA embraces their legacy and strives to include everyone who wants to participate in its ongoing exploration. “Progress is driven by questioning our assumptions and cultural assumptions,” NASA Administrator Charles Bolden says in a new video. “Embracing diversity and inclusion is how we as a nation will take the next giant leap in exploration.“ 

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Let’s learn about today’s black heroes we all can look up to!

The Portuguese man o’ war delivers a powerful sting to its prey—and sometimes to people—through venom-filled structures on its tentacles. It is not a jellyfish, but rather a colony of different types of zooids (small animals). Jean Louis Coutant engraved the plate for this illustration.

These are rainbow eucalyptus trees (Eucalyptus deglupta) and hail from the Philippine Islands.

The trees get their name from the striking colours observed on their trunks and limbs. Although it may look like someone took a paintbrush to them, these colours are entirely natural. Unlike most trees, the rainbow eucalyptus does not have a thick, cork-like layer of bark on its trunk. The bark is smooth and as it grows it ‘exfoliates’ layers of spent tissue. This exfoliation technique occurs at different stages and in different zones of the tree.

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(Image caption: A new technique called magnified analysis of proteome (MAP), developed at MIT, allows researchers to peer at molecules within cells or take a wider view of the long-range connections between neurons. Credit: Courtesy of the researchers)

Imaging the brain at multiple size scales

MIT researchers have developed a new technique for imaging brain tissue at multiple scales, allowing them to peer at molecules within cells or take a wider view of the long-range connections between neurons.

This technique, known as magnified analysis of proteome (MAP), should help scientists in their ongoing efforts to chart the connectivity and functions of neurons in the human brain, says Kwanghun Chung, the Samuel A. Goldblith Assistant Professor in the Departments of Chemical Engineering and Brain and Cognitive Sciences, and a member of MIT’s Institute for Medical Engineering and Science (IMES) and Picower Institute for Learning and Memory.

“We use a chemical process to make the whole brain size-adjustable, while preserving pretty much everything. We preserve the proteome (the collection of proteins found in a biological sample), we preserve nanoscopic details, and we also preserve brain-wide connectivity,” says Chung, the senior author of a paper describing the method in the July 25 issue of Nature Biotechnology.

The researchers also showed that the technique is applicable to other organs such as the heart, lungs, liver, and kidneys.

The paper’s lead authors are postdoc Taeyun Ku, graduate student Justin Swaney, and visiting scholar Jeong-Yoon Park.

Multiscale imaging

The new MAP technique builds on a tissue transformation method known as CLARITY, which Chung developed as a postdoc at Stanford University. CLARITY preserves cells and molecules in brain tissue and makes them transparent so the molecules inside the cell can be imaged in 3-D. In the new study, Chung sought a way to image the brain at multiple scales, within the same tissue sample.

“There is no effective technology that allows you to obtain this multilevel detail, from brain region connectivity all the way down to subcellular details, plus molecular information,” he says.

To achieve that, the researchers developed a method to reversibly expand tissue samples in a way that preserves nearly all of the proteins within the cells. Those proteins can then be labeled with fluorescent molecules and imaged.

The technique relies on flooding the brain tissue with acrylamide polymers, which can form a dense gel. In this case, the gel is 10 times denser than the one used for the CLARITY technique, which gives the sample much more stability. This stability allows the researchers to denature and dissociate the proteins inside the cells without destroying the structural integrity of the tissue sample.

Before denaturing the proteins, the researchers attach them to the gel using formaldehyde, as Chung did in the CLARITY method. Once the proteins are attached and denatured, the gel expands the tissue sample to four or five times its original size.

“It is reversible and you can do it many times,” Chung says. “You can then use off-the-shelf molecular markers like antibodies to label and visualize the distribution of all these preserved biomolecules.”

There are hundreds of thousands of commercially available antibodies that can be used to fluorescently tag specific proteins. In this study, the researchers imaged neuronal structures such as axons and synapses by labeling proteins found in those structures, and they also labeled proteins that allow them to distinguish neurons from glial cells.

“We can use these antibodies to visualize any target structures or molecules,” Chung says. “We can visualize different neuron types and their projections to see their connectivity. We can also visualize signaling molecules or functionally important proteins.”

High resolution

Once the tissue is expanded, the researchers can use any of several common microscopes to obtain images with a resolution as high as 60 nanometers — much better than the usual 200 to 250-nanometer limit of light microscopes, which are constrained by the wavelength of visible light. The researchers also demonstrated that this approach works with relatively large tissue samples, up to 2 millimeters thick.

“This is, as far as I know, the first demonstration of super-resolution proteomic imaging of millimeter-scale samples,” Chung says.

“This is an exciting advance for brain mapping, a technique that reveals the molecular and connectional architecture of the brain with unprecedented detail,” says Sebastian Seung, a professor of computer science at the Princeton Neuroscience Institute, who was not involved in the research.

Currently, efforts to map the connections of the human brain rely on electron microscopy, but Chung and colleagues demonstrated that the higher-resolution MAP imaging technique can trace those connections more accurately.

Chung’s lab is now working on speeding up the imaging and the image processing, which is challenging because there is so much data generated from imaging the expanded tissue samples.

“It’s already easier than other techniques because the process is really simple and you can use off-the-shelf molecular markers, but we are trying to make it even simpler,” Chung says.

Checking Cancer At Its Origin..

In a first, the lab led by Leonard Zon at Boston Children’s Hospital has visualised the emergence of the primary melanoma cell in transgenic zebrafish that harbour the human oncogenic BRAFV600E mutation in melanocytes. This cancerous state is characterised in maturing fish by the formation of neural crest progenitors [NCPs], which are the predecessors of melanocytes and are only seen in the embryonic stage of healthy zebrafish.

The Zon lab placed the human mutated oncogene, BRAFV600E (a characteristic of benign human nevi/moles) under the control of a melanocyte-specific promoter and introduced it into the zebrafish. Generations of this transgenic fish were engineered such that they were also deficient in functional p53 (loss of function mutation). They used previous findings that in healthy zebrafish, a gene called crestin is expressed only in the embryonic NCPs and never throughout maturity, but is re-expressed selectively in melanomatous cells during adulthood. crestin was cloned adjacent to a reporter, enhanced green fluorescent protein [EGFP] for live imaging purposes.

The developmental phases of the fish, that were by now triple transgenic (for human BRAFV600E, p53 LOF and crestin:EGFP) were observed by live imaging; ~21 days after fertilisation, the expression of crestin:EGFP localised precisely to the (future) melanoma sites, and the very first triple-transgenic (individual) cells that went on to form larger masses of cells were also observed. To summarise, melanoma formation was observed in three stages: individual fluorescent cells, followed by these cells multiplying to form groups of <50 cells, and lastly these groups forming raised lesions. This consistently held true, with all 30 observed individual cells turning into 30 lesions. These results are illustrated in Figure 1.

Figure 1. In the top left box, a single cell is visualised as it multiplies into a group of melanoma cells (top right). The bottom images show the raised melanoma lesion as observed by the naked eye and by live imaging. The green fluorescence emitted from EGFP indicates that it is localised only to the melanoma (as is crestin expression), that is, it has not metastasised elsewhere. 

These pre-cancerous cells were also shown to be self-sustaining and tumourigenic: when fish scales containing the mutant cells were transplanted to another part of the same fish (auto-transplant) or to another fish (allo-transplant) that was also exposed to radiation, the cells proliferated in the new site, as well as penetrated the hypodermis underneath (Figure 2).

Figure 2. The fluorescence indicates a single scale being auto-transplanted elsewhere on the same fish. As the days progress, the patch expands as well, and after day 33, the cells penetrate deeper into the hypodermis and thrive independently, and excising the transplanted scale proves futile. 

Role of Transcription Factor sox10

sox10 is a master TF in NCP and its over-expression has been correlated with increased crestin expression, and accordingly, sox10 over expression in the transgenic melanocytes accelerated the melanoma onset. Following the logical train of thought that sox10 promotes melanoma progression, it was then targeted by CRISPR-Cas9 and inactivated in the transgenic cells. This resulted in a delayed onset of melanoma (180 days) compared to the controls (133 days). sox10 is also known to be expressed in most human melanoma cell lines. Moreover, the DNA element that acts as the binding site for Sox10 is also found in a hyper-acetylated [H3K27Ac], super-enhancer state. This is an epigenetic alteration and may prove a useful target in therapy (ex. HAT inhibitors).

Summary

The key finding clears up a hitherto ambiguous association between a reversion to stem/progenitor cell-like status and cancer: it indicates that the apparent devolution of a specialised cell to a primitive cellular state is not a consequence of cancer progression, but that it is an hallmark of pre-cancerous cells that may contribute to tumour progression. The rarity of melanoma formation among the mutant cells also suggests that the double mutant [BRAFV600E; p53 LOF] is not the only factor to influence the onset. Experimentally, crestin expression was a definitive prelude to formation of nevi which transformed into full-fledged raised melanomas in that spot.

This discovery has two chronological applications: first, of the many susceptible melanocytes harbouring the mutated oncogene, we can find out which are most likely to enter the melanoma state. Peaks in the expression profile of sox2, or a couple other TFs, dlx2 and tfap2, can prove to be a telltale pre-melanoma signature and thus be used in diagnosis. Secondly, by doing so, these can be better targeted early on before they’ve disseminated and become virtually untreatable.

Kaufman CK, Mosimann C, Fan ZP, Yang S, Thomas AJ, Ablain J, et al. A zebrafish melanoma model reveals emergence of neural crest identity during melanoma initiation. Science. 2016;351[6272]:aad2197–aad2197.