The next 5 weeks of exams in one gif.
The next 5 weeks of exams in one gif.
Quadruple fluorescence image revealing the complexity of the optic fiber layer of a mouse retina. Optic nerve axons and glial cells are stained red and green, respectively while actin in the blood vessel-ensheathing endothelial cells are stained blue. DNA and RNA are in orange. The image was acquired by confocal microscopy.
Viruses in the gut protect from infection | Nature
“Mucus is everywhere,” says microbiologist Jeremy Barr. Almost every animal uses it to make a barrier that protects tissues that are exposed to the environment, such as the gut or lungs. Now, Barr and a team of researchers have discovered that mucus is also the key to an ancient partnership between animals and viruses.
Barr and his colleagues, who are based at San Diego State University in California, show that animal mucus — whether from humans, fish or corals — is loaded with bacteria-killing viruses called phages. These protect their hosts from infection by destroying incoming bacteria. In return, the phages are exposed to a steady torrent of microbes in which to reproduce. “It’s a unique form of symbiosis, between animals and viruses,” says Rotem Sorek, a microbial geneticist at the Weizmann Institute of Science in Rehovot, Israel, who was not involved in the research.
Bovine Pulmonary Artery Endothelial Cells
The actin filaments in these fixed bovine pulmonary artery endothelial cells (BPAEC) were labeled with phalloidin conjugated to Alexa Fluor® 647 dye. Phalloidin is a deadly toxin isolated from the “death cap” mushroom that binds specifically at the interface between F-actin subunits. Alexa Fluor® 647 exhibits far-red fluorescence, which has been pseudo-colored magenta in this image. Nuclei were stained with blue-fluorescent DAPI.
Photo courtesy of the Life Technologies Corporation.
Aspirate for a cutaneous mass over the right scapular region of a 2 year-old, male-castrated, Labrador Retriever. The dog’s owner felt this mass while brushing him out (it is spring time….coats are ‘blowing’ everywhere. We have to vacuum weekly to keep the fur at bay!) The mass does not appear to be painful on manipulation, and the patient is described as healthy otherwise.
The cytology is full of these large round cells containing amorphous, variably-sized, magenta globules. Is this a mast cell tumor? Nope! Although these lesions may often be confused for mast cell tumors on cytology. All of those round cells are actually macrophages - see their foamy cytoplasm? As for that magenta substance? That material is vaccine adjuvant being gobbled up by the macrophages. A key piece of information I left out….the dog was vaccinated over the scapula a month earlier :-P
Cytologic diagnosis: Moderate, mixed (lymphocytic, macrophagic) inflammation with intralesional adjuvant material. A.K.A. local vaccine reaction. Such lesions may be there for quite some time post vaccination…I recently saw such a sample from a dog vaccinated 6 months prior!
Radiograph of a turkey vulture showing a fractured ulna
Hemangioblastomas (capilliary hemangioblastomas) are tumors of the central nervous system that originate from the vascular system usually during middle-age. Usually occur in the cerebellum, brain stem or spinal cord but sometimes these tumors occur in other sites such as the spinal cord and retina. They may be associated with other diseases such as polycythemia, pancreatic cysts and Von Hippel-Lindau syndrome (VHL syndrome).
Hemangioblastomas are most commonly composed of stromal cells in small blood vessels and of endothelial cells. In VHL syndrome the von Hippel-Lindau protein (pVHL) is dysfunctional, usually due to mutation and/or gene silencing. In normal circumstances, pVHL is involved in the inhibition of hypoxia-inducible factor 1 α (HIF-1α) by ubiquitin mediated proteosomal degradation. In these dysfunctional cells pVHL cannot degrade HIF-1α, causing it to accumulate. HIF-1α causes the production of vascular endothelial growth factor, platelet derived growth factor B, erythropoietin and transforming growth factor alpha, which act to stimulate growth of cells within the tumour.
Pleural fluid from a 6 year-old, male-castrated, Domestic Longhair. Patient was previously diagnosed with congestive heart failure; subjectively the owner appreciated that the cat was responding well to heart failure therapy. However, he developed acute-onset respiratory issues yesterday and was re-examined
The pleural fluid had a cell count of 8,000 nucleated cells/uL and a total protein of 3.8g/dL. The key to this diagnosis is all those tiny mononuclear cells in the fluid! Who are they you may ask? Copious numbers small, mature lymphocytes! Lymphocytes comprised ~87% of all nucleated cells, with neutrophils and macrophages making up the rest. Many macrophages had clear punctate vacuoles in their cytoplasm, likely lipid vacuoles. That would make sense, as this is a chylous effusion!
The most common cause of chylothorax in the cat is cardiac disease. Apparently the poor thing was not being controlled well enough for his heart failure. Cats are so damn good at hiding their diseases! You can confirm chylous effusion by comparing the ratio of fluid triglycerides to serum triglycerides. If twice as much lipid is present in the fluid, a chylothorax it is!