Droplet Information and Courses from MediaLab, Inc.

At John’s particular hospital, a stop sign on the door means not only means respiratory isolation, but also that special precautions for tuberculosis are in effect. At this point, John should obtain a a special particulate respirator mask which will be available outside the patient's room. He should put on the mask before entering the room, wash his hands before and after contact with the patient, and wear gloves and appropriate protective clothing during all contact with the patient. TB and most respiratory infections are transmitted via droplets in the air from respiratory secretions – thus the need for the masks.

There are a number of abnormalities of sperm morphology. Abnormal heads can include enlarged head, double head, round head, constricted head, amorphous head, pinhead, and acute tapering forms. There are also heads with abnormal numbers of vacuoles. Midpiece abnormalities include distended and thin midpiece regions. Abnormal tails include short tails, double, triple or multiple tails, coiled tails, broken tails, or absent tail. Cytoplasmic droplets are also seen in some specimens. These are large regions of cytoplasm just below the head assumed to represent failure of complete sperm maturation or a sign of either toxicity or oxidation. There have also been reports that cytoplasmic droplets may be artifacts from the fixation and staining for morphology analysis.

A fourth type of cast is the fatty cast. Fatty casts are clear cylinders containing droplets of fat which are highly refractile. These casts originate from the breakdown of the tubular epithelium containing oval fat bodies. Fatty casts are characteristic of degenerative tubular disease and are frequently seen with heavy proteinuria.

Oval fat bodies are degenerating tubular epithelial cells filled that contain refractile fat droplets. These fats have been absorbed by the tubular cells after being leaked through abnormal glomeruli. They appear as grape-like clusters of variable size and are highly refractile.

The natural history of TB infection is usually followed by an immune response and latency after exposure. In about 5-10% of cases, the latent period progresses to an active infection.The organism that causes TB infection is Mycobacterium tuberculosis. This organism is pictured in the photograph to the right as observed when stained with acridine orange stain. Infection occurs when a susceptible person inhales droplet nuclei containing Mycobacterium tuberculosis and the organism reaches the alveoli of the lungs.About 2-12 weeks after infection, the immune system limits multiplication of additional bacteria and the immunological test becomes positive.Latent tuberculosis infection (LTBI) is the stage when the viable organism remains in the body, and the patient has no symptoms and is non-infectious.Most infected persons do not experience clinical illness and are noninfectious. About 5-10% of persons infected with Mycobacterium tuberculosis who are not treated will develop TB during their lifetime. The risk for progression is highest during the first several years after infection.TB infects the lungs most often; however, it can infect almost any organ in the body, including bones and joints.