Color enhanced transmission electron micrograph (TEM) of a
Hantavirus. Hantavirus is a respiratory disease carried in wild rodents
such as deer mice. Mice do not appear ill while carrying the hantavirus.
People become infected after breathing airborne particles of urine,
droppings or saliva from infected rodents. Hantavirus causes flu-like
symptoms that eventually cause the lungs to fill with fluid, making
breathing difficult. Medical attention must be sought as soon as
infection is detected. Most cases of Hantavirus reported in the U.S.
have been in the rural Western states.
The Apollo 11 crew leaves Kennedy Space Center's Manned Spacecraft
Operations Building during the pre-launch countdown. Mission commander
Neil Armstrong, command module pilot Michael Collins, and lunar module
pilot Buzz Aldrin prepare to ride the special transport van to Launch
Complex 39A where their spacecraft awaited them.
Computer generated model of the chemical structure of Vitamin A.
Vitamin A maintains skin and mucus membranes, and is needed for night
vision. Its absence from diet leads to weight loss, night blindness, and
to an increased susceptibility to infections. Vitamin A is structurally
related to carotene. Carotene is converted into vitamin A in the liver,
two molecules of vitamin A are formed from on molecule of beta
carotene, hence good sources of carotene, such as green vegetables are
good potential sources of vitamin A. Vitamin A is manufactured from
fish-liver oil and by synthesis from beta-ionone. Good sources of
Vitamin A are butter, milk, cheese, yogurt, sweet potatoes, carrots, red
peppers, chilies, leafy green vegetables, tomatoes, apricots, and
Varicella-zoster virus (VZV) entering the bloodstream. VZV s a
herpes virus that can cause chickenpox in children and shingles (Herpes
zoster) in adults. The virus is transmitted by airborne viral particles
shed from the skin of an infected person. The new host breathes in the
virus, which enters the mucous membrane in a person's respiratory tract
and begins to spread without its envelope from cell to cell. The virus
invades T-cells of the blood and those T-cells carry the virus to the
skin. There, the virus can recreate its envelope because the top layer
of the skin lacks the endosomal pathway that removes glycoproteins from
Light micrograph of a section of human liver affected by
hemosiderosis, a condition characterized by the excessive deposition of
iron in the liver and caused by a high dietary intake or following
repeated blood transfusions. Iron is stored as hemosiderin in the
Kuppfer cells and hepatocytes (liver cells) and causes liver cell death
and cirrhosis. Here, some cells contain large quantities of iron which
has been stained black. Acomparable condition, hemochromatosis, results
from an inherited defect in iron metabolism and affects other organs in
addition to the liver. Magnification: x100 at 35mm size.
Triclosan is a potent wide-spectrum antibacterial and antifungal
agent. It is used in soaps (0.10-1.00%), deodorants, toothpastes,
shaving creams, mouth washes, and cleaning supplies. It may also be used
in kitchen utensils, toys, bedding, socks, and trash bags. Triclosan
reduces bacterial contamination on the hands and on treated products.
Showering with 2% triclosan is a recommended procedure to decolonize
patients whose skin carries methicillin-resistant Staphylococcus aureus
(MRSA). At low concentrations, triclosan acts as a bacteriostatic; it
targets bacteria mainly by inhibiting fatty acid synthesis. Key:
Carbon: blue, Hydrogen: cream, Chlorine: yellow, Oxygen: green.
MMR vaccine being drawn into a syringe. This combined vaccine
protects infants from three viral diseases: measles, mumps and rubella.
The first injection is given in a child's second year, followed by a
booster three years later. The vaccine consists of weakened samples of
the three viruses. When injected, the vaccine stimulates the body's
immune system to produce antibodies, but without causing infection. The
immune system can then respond quickly against future infections by the
viruses. In recent years, there has been public concern about a
possible link between the MMR vaccine and autism. However,
epidemiological studies suggest that there is no link.