Three-dimensional map of a rotavirus | ZEISS Microscopy
This image shows a three-dimensional reconstruction of a rotavirus at a magnification of about 50,000. Rotavirus infects humans as well as other animals and causes severe diarrhea in infants and young children. There are very few fatalities in the United States and other places where a vaccine is available, but elsewhere, the virus is responsible for more than 450,000 deaths each year. Image courtesy of the National Resource for Automated Molecular Microscopy, The Scripps Research Institute, La Jolla, California.
Causal Agent and Life Cycle (above):
Many species of Cryptosporidium exist that infect humans and a wide range of animals. Although Cryptosporidium parvum and Cryptosporidium hominis (formerly known as C. parvum anthroponotic genotype or genotype 1) are the most prevalent species causing disease in humans, infections by C. felis, C. meleagridis, C. canis, and C. muris have also been reported.
Follow steps in graph above:
Sporulated oocysts, containing 4 sporozoites, are excreted by the infected host through feces and possibly other routes such as respiratory secretions . Transmission of Cryptosporidium parvum and C. hominis occurs mainly through contact with contaminated water (e.g., drinking or recreational water). Occasionally food sources, such as chicken salad, may serve as vehicles for transmission. Many outbreaks in the United States have occurred in waterparks, community swimming pools, and day care centers. Zoonotic and anthroponotic transmission of C. parvum and anthroponotic transmission of C. hominis occur through exposure to infected animals or exposure to water contaminated by feces of infected animals . Following ingestion (and possibly inhalation) by a suitable host , excystation occurs. The sporozoites are released and parasitize epithelial cells (, ) of the gastrointestinal tract or other tissues such as the respiratory tract. In these cells, the parasites undergo asexual multiplication (schizogony or merogony) (, , ) and then sexual multiplication (gametogony) producing microgamonts (male) and macrogamonts (female) . Upon fertilization of the macrogamonts by the microgametes (), oocysts (, ) develop that sporulate in the infected host. Two different types of oocysts are produced, the thick-walled, which is commonly excreted from the host , and the thin-walled oocyst , which is primarily involved in autoinfection. Oocysts are infective upon excretion, thus permitting direct and immediate fecal-oral transmission.
Note that oocysts of Cyclospora cayetanensis, another important coccidian parasite, are unsporulated at the time of excretion and do not become infective until sporulation is completed. Refer to the life cycle of Cyclospora cayentanensis for further details.
Many individuals who have been diagnosed with coronary atherosclerosis take medications to help hinder further progression of the disease. The class of drugs known as statins, which effectively reduce elevated cholesterol levels, have been especially useful in the battle against the condition and other forms of heart disease.
I call this one the water recycler. #largeintestine #histology #histonerd (at University of the Sunshine Coast)
cultured adipocytes (fat cells) with bead-like lipid inclusions
credit: Shingo Kajimura
dream-by-day asked me what it is that I do to make money.
I am a histology technician. I turn whole human specimens into slides that are stained for a diagnosis. My lab specializes in oncology research, but we gross in all of the surgical pathology specimens. I am able to see all of the beautiful and terrifying things that the human body is capable of, and I make a stupid amount of money for only having a certification in my field.
So we begin with a tumor specimen that can be as small as a pea
or ovarian cysts that weigh 30# or more
And then it goes through the the assembly line of grossing, processing, embedding, sectioning, staining (routine hematoxylin & eosin, special stains, or ImmunoHistoChemistry if it is a paraffin block. We also perform ImmunoFluorescence on the renal and cardiac biopsies), and finally to the Pathologist for diagnosis. All of which are explained below. Thank you NSH for giving such a concise description.
Grossing & Fixation – Tissue specimens taken from routine surgical cases, autopsies, or other scientific investigations are examined, described and trimmed to proper size. This process is referred to as “grossing the specimen”. The resulting specimens are preserved by placing them in solutions designed to prevent decomposition. This is known as fixation. It’s usually 10% Neutral Buffered Formalin (37%-40% formaldehyde).
Processing – water is removed from the tissue and replaced by melted paraffin wax. The wax infiltrates the tissue and provides the necessary support when cutting the tissue into thin slices which will eventually be examined under a microscope.Embedding – Before the wax permeated tissue can be cut it is placed in a larger wax block for additional holding support during sectioning.
Sectioning – The tissue is mounted onto a delicate instrument called a microtome. An extremely sharp knife is used to cut sections of the tissue embedded in the wax block. These sections are cut one after another to form a ribbon, which is floated on warm water to soften and flatten tissue sections. These sections are then placed on microscopic slides and stored for future procedures.Staining – Staining causes tissue components to change colors when brought into contact with different chemicals. In addition to dyes, antibodies are reacted with tissues to identify specific tumor cell lines with a method called Immunohistochemistry. This technique is critical to guiding the patient’s physician in selecting the most effective tumor treatment. DNA probes are also applied to tissue sections to identify the presence of bacterial and viral infections and some tumors. When staining is completed, the tissue section is ready for examination under a microscope by a pathologist or other scientific investigator. Without specialized staining techniques, many tissue components would remain invisible.
So, yeah. That’s what I do all day.
Peyer’s patches and thin muscle layers. This is the #smallintestine #ileum. #histology #histonerd