The cornea of humans and animals are composed of three distinct layers that are illustrated above. When the epithelial layer is damaged and the stroma is exposed, this is a corneal ulcer. Fluorescein dye is taken up only by stromal cells and if there is an ulcer it will turn bright green.
If an ulcer is not found or if an animal with an ulcer is given medication with a steroid in it the ulcer can get worse. Eventually the ulcer can extend through the stroma and expose Descemet’s membrane causing a descemetocele . This is when the intraocular contents push out on the membrane causing it to “bubble” out. If not treated immediately it can rupture and the contents of the eye will leak out causing blindness.
(Photo from AAFP.org)
A intussuception as seen on CT
An intussusception is a medical condition in which a part of the intestine has invaginated into another section of intestine, similar to the way in which the parts of a collapsible telescope slide into one another.This can often result in an obstruction. The part that prolapses into the other is called the intussusceptum, and the part that receives it is called the intussuscipiens.Early symptoms can include nausea, vomiting (sometimes bile stained [green color]), pulling legs to the chest area, and intermittent moderate to severe cramping abdominal pain. Pain is intermittent not because the intussusception temporarily resolves, but because the intussuscepted bowel segment transiently stops contracting. Later signs include rectal bleeding, often with “red currant jelly” stool (stool mixed with blood and mucus), and lethargy. Physical examination may reveal a “sausage-shaped” mass felt upon palpation of the abdomen.
Head first: reshaping how traumatic brain injury is treated
Traumatic brain injury affects 10 million people a year worldwide and is the leading cause of death and disability in children and young adults. A new study will identify how to match treatments to patients, to achieve the best possible outcome for recovery.
The human brain – despite being encased snugly within its protective skull – is terrifyingly vulnerable to traumatic injury. A severe blow to the head can set in train a series of events that continue to play out for months, years and even decades ahead. First, there is bleeding, clotting and bruising at the site of impact. If the blow is forceful enough, the brain is thrust against the far side of the skull, where bony ridges cause blood vessels to lacerate. Sliding of grey matter over white matter can irreparably shear nerve fibres, causing damage that has physical, cognitive and behavioural consequences. As response mechanisms activate, the brain then swells, increasing intracranial pressure, and closing down parts of the microcirculatory network, reducing the passage of oxygen from blood vessels into the tissues, and causing further tissue injury.
It is the global nature of the damage – involving many parts of the brain – that defines these types of traumatic brain injuries (TBIs), which might result from transport accidents, assaults, falls or sporting injuries. Unfortunately, both the pattern of damage and the eventual outcome are extremely variable from patient to patient.
“This variability has meant that TBI is often considered as the most complex disease in our most complex organ,” said Professor David Menon, Co-Chair of the Acute Brain Injury Programme at the University of Cambridge. “Despite advances in care, the sad truth is that we are no closer to knowing how to navigate past this variability to the point where we can link the particular characteristics of a TBI to the best treatment and outcome.”Read more
Scientists Develop Promising Drug Candidates for Pain, Addiction
Scientists from the Florida campus of The Scripps Research Institute (TSRI) have described a pair of drug candidates that advance the search for new treatments for pain, addiction and other disorders.
The two new drug scaffolds, described in a recent edition of The Journal of Biological…
The scientists harvested body parts from wild koalas that had been humanely euthanized for other reasons. When scientists looked at the voice boxes of male koalas, they found their vocal cords weren’t large enough to create the animals’ extremely low-pitched mating bellows. But further examination revealed a second, much larger pair of vocal folds located outside of the larynx, where the oral and nasal cavities connect.
Charlton and his colleagues used a combination of physical, video, and acoustic analyses to demonstrate that the newly discovered vocal folds outside of the larynx are capable of producing extremely low-pitched sound as the koala inhales air through its nostrils. (Read more about koalas in National Geographic magazine.)
It’s the first evidence in a land-dwelling mammal of an organ other than the larynx that is devoted to producing sound.
The only other example of a specialized sound-producing organ in mammals that is independent of the larynx is the phonic lips that toothed whales use to generate echolocation—or the natural sonar that helps them find prey, said Charlton, whose study is published in the journal Current Biology.
But Charlton and colleagues plan to keep looking to find other animals with such low voices.
here you can learn more and listen to a recording of the koalas
Scanning electron micrograph of an apoptotic HeLa cancer cell. Thomas Deerinck, UC San Diego
Researcher Thomas J. Kipps, MD, PhD, professor of medicine and deputy director of research operations at UC San Diego Moores Cancer Center, is principal investigator for one of six “Disease Team” awards approved December 12 by the governing board of the California Institute for Regenerative Medicine (CIRM). The grant, for $4.18 million, is part of a total $61 million awarded to fund work which promises to move therapies out of the lab and into clinical trials in patients.
The funding was approved by the stem cell agency’s governing board, the Independent Citizen’s Oversight Committee (ICOC), at a two-day meeting in Los Angeles.
The UC San Diego research team’s goal is to develop new therapies that specifically target a protein found only on the surface of cancer stem cells. The protein, called Receptor-tyrosine-kinase-like Orphan Receptor 1 or ROR1, is produced in great amounts during embryogenesis, when it helps regulate early muscle and skeletal development. Later, ROR1 is turned off. Normal cells and tissues in adults do not typically express ROR1.
But multiple types of cancer stem cells do, co-opting ROR1 to promote their growth and survival. In fact, Kipps and colleagues have found that exploitation of ROR1 by cancer cells is critical to the disease’s spread or metastasis, estimated to be responsible for 90 percent of cancer-related deaths.
With earlier CIRM funding, Kipps, fellow researcher Catriona Jamieson, MD, PhD – associate professor of medicine and director of the stem cell research program at Moores Cancer Center – and colleagues developed a humanized monoclonal antibody that specifically targets and inhibits the functioning of ROR1.
“Because this antibody does not bind to normal cells, it can serve as the ‘magic bullet’ to deliver a specific hit to cancer stem cells,” the researchers said in their CIRM proposal.
They plan to conduct clinical trials with the antibody, first in patients with chronic lymphocytic leukemia, the most common type of blood cancer in the United States, to determine appropriate dose levels and safety protocols, followed by clinical trials involving patients with other types of cancer, including solid tumor types like breast and lung.
“We will investigate the potential for using this antibody to deliver toxins selectively to cancer stem cells,” the researchers wrote. “This selective delivery could be very active in killing cancer stem cells without harming normal cells in the body because they lack expression of ROR1. With this antibody, we can develop curative stem-cell-directed therapy for patients with any one of many different types of currently intractable cancers.”
The CIRM Disease Team awards are designed to encourage multidisciplinary teams of researchers from academic institutions, medical centers and industry to work together and to develop new treatments for a broad range of therapies. The recipients were selected from 14 applications, all of which were reviewed by an independent group of internationally renowned scientists.
This image depicts a synaptic vesicle drifting through the crowded cytoplasm of a neuron. Other structures in the image include actin filaments as well as various enzymes and other free-floating proteins. This image was developed in collaboration with Rob Lue and Alain Viel at Harvard University. The vesicle is based on data from Takamori et al’s paper “Molecular Anatomy of a Trafficking Organelle”. Vote for this image for the National Science Foundation Visualization Challenge.
Fresh or Frozen - which is more nutritious? Most are under the assumption that fresh is better, but that may not always be the case! Find out why:
Evolutionary Adaptation of Pruney Fingers
You know how your fingers get all pruney and wrinkly when you’ve been in water for a while?
According to Mark Changizi, an evolutionary neurobiologist, “the wrinkles act like rain treads on tyres. They create channels that allow water to drain away as we press our fingertips on to wet surfaces. This allows the fingers to make greater contact with a wet surface, giving them a better grip.”
You may think that this all happens because your fingers are absorbing water - think again. When nerves to fingers are severed, this unique acclimation does not occur. It’s thus most likely controlled by the nervous system.
Microscopic life in a single drop of pond water. Peter Matulavich/Science Photo Library. Source here (definitely watch).
In 1905, E. G. Conklin published a remarkable fate map of the ascidian embryo. He showed that “all the principle organs of the larva in their definitive positions and proportions are here marked out in the 2-cell stage by distinct kinds of protoplasm.” This study of cell lineage has been the basis for all subsequent research on the autonomous specification of tunicates. The color plates of this study are considered to be some of the best examples of embryological illustration and descriptive anatomy.
In most of the scientific literature that I’ve read, autosomal (non-sex) chromosomes are referred to by their numbers (in decreasing size), after the species is somehow specified. So the second chromosome in humans would simply be called, “Chromosome 2.” This could refer specifically to either of the two chromosomes making up the pair known as “Chromosome 2,” or to the pair as a category.
As for how much/often to drink water, there are too many factors involved for me to give you a straightforward answer. Age, weight, gender, geographical location, degree of physical activity, and diet have to be taken into consideration. For example, a considerable amount of water is absorbed by our bodies from foods we eat, and a diet of fresh fruits and vegetables would yield a much higher water content than one of greasy snacks. This all complicates the “eight glasses a day” rule, which seems to be based more on tradition than scientific research.
Some say you aren’t sufficiently hydrated until urine is clear in color. While that could be a good indicator, it’s not really a guideline in frequency/quantity of water consumption, and not a universal indicator. For example, an average person can drink 20 cups of water and still have brightly colored urine if they are taking a B complex vitamin or have elevated concentrations of B vitamins in their blood.
The only real guideline is to, at the very least, drink when you’re thirsty, until you’re not thirsty anymore. We experience the feeling of thirst when blood plasma volume falls below a certain threshold, or when interstitial fluid (fluid outside our cells) becomes hypertonic (too many solutes, and not enough water) - both leading to dehydration. This may seem like useless advice, since thirst is enough of a drive to drink water, without me advising you to - but really it’s the only conclusive scientific answer I can provide.
Photo Credit: The ABC’s of DNA — Chromosomes