Modern Medical Laboratory Journal

The researchers had applied to the US Food and Drug Administration (FDA) to do a clinical trial of the pig hearts in people but were turned down. According to Muhammad Mohiuddin, the University of Maryland surgeon who leads the research team behind the transplant, the agency was concerned about ensuring that the pigs came from a medical-grade facility and wanted the researchers to transplant the hearts into ten baboons before moving on to people. But 57-year-old David Bennett gave Mohiuddin’s team a chance to jump straight to a human transplant.
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Materials fall into one of two categories. The first are materials that demonstrate the same optical properties in all directions, such as gases, liquids, and certain glasses and crystals. These are isotropic materials. Because they are optically the same in all directions, they have only one RI. Light, therefore, passes through them at the same speed with no directional restrictions.

The second category is anisotropic materials, which have optical properties that vary with the orientation of the incoming light and the optical structure of the material. About 90% of all solid materials are anisotropic. The RIs vary in anisotropic materials depending both on the direction of the incident light and on the optical structure. 

HIV stands for human immunodeficiency virus. It weakens a person’s immune system by destroying important cells that fight disease and infection. There is currently no effective cure for HIV. But with proper medical care, HIV can be controlled. Some groups of people in the United States are more likely to get HIV than others because of many factors, including their sex partners and risk behaviors.
Newer, Improved HIV Tests Allow for Earlier HIV Detection

HIV tests have improved substantially over the years, and are now easier and less expensive, with a more rapid turnaround time for results.

Three types of HIV tests are available:

• Nucleic acid tests (NATs) — detects HIV ribonucleic acid (RNA)
• Antigen/antibody combination tests — detects HIV p24 antigen as well as HIV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies
• Antibody tests — detects HIV IgM and/or IgG antibodies

Following an exposure that leads to HIV infection, the amount of time during which no existing diagnostic test is capable of detecting HIV is called the eclipse period.
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A liver transplant is a surgical procedure that removes a liver that no longer functions properly (liver failure) and replaces it with a healthy liver from a deceased donor or a portion of a healthy liver from a living donor. Liver transplant is usually reserved as a treatment option for people who have significant complications due to end-stage chronic liver disease. Liver transplant may also be a treatment option in rare cases of sudden failure of a previously healthy liver.
In 1963, Starzl et al. performed the first liver transplantation. In the first five liver transplantations no patient survived more than 23 days. In 1967, stimulated by Calne who used antilymphocytic serum, Starzl began a successful series of liver transplantation. Until 1977, 200 liver transplantations were performed in the world. In that period, technical problems were overcome. Roy Calne, in 1979, used the first time cyclosporine in two patients who had undergone liver transplantation. In 1989, Starzl et al. reported a series of 1,179 consecutives patients who underwent liver transplantation and reported a survival rate between one and five years of 73% and 64%, respectively.  Liver Transplantation Program was initiated at Hospital Israelita Albert Einstein in 1990 and so far according to the American Liver Foundation, around 8,000 liver transplant surgeries are performed in the United States every year.
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The ultrasound image is produced based on the reflection of the waves off of the body structures. In an ultrasound exam, a transducer both sends the sound waves and records the echoing (returning) waves. When the transducer is pressed against the skin, it sends small pulses of inaudible, high-frequency sound waves into the body. As the sound waves bounce off internal organs, fluids and tissues, the sensitive receiver in the transducer records tiny changes in the sound's pitch and direction. A computer instantly measures these signature waves and displays them as real-time pictures on a monitor. The technologist typically captures one or more frames of the moving pictures as still images. They may also save short video loops of the images.
Ultrasound imaging is a medical tool that can help a physician evaluate, diagnose and treat medical conditions. Common ultrasound imaging procedures include:

• Abdominal ultrasound (to visualize abdominal tissues and organs)
• Bone sonometry (to assess bone fragility)
• Breast ultrasound (to visualize breast tissue)
• Doppler fetal heart rate monitors (to listen to the fetal heart beat)
• Doppler ultrasound (to visualize blood flow through a blood vessel, organs, or other structures)
• Echocardiogram (to view the heart)
• Fetal ultrasound (to view the fetus in pregnancy)
• Ultrasound-guided biopsies (to collect a sample of tissue)
• Ophthalmic ultrasound (to visualize ocular structures
• Ultrasound-guided needle placement (in blood vessels or other tissues of interest)

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The renal functional capacity can be assessed by measuring serum creatinine/blood urea nitrogen (BUN) or by urea and creatinine clearance. There are two types of dialysis procedures; it may be hemodialysis (using a machine/artificial kidney-like apparatus) or peritoneal dialysis (using a peritoneal membrane as a filter). Peritoneal dialysis is recommended for younger patients because of its flexibility and can be performed at home. Hemodialysis is done for patients with no residual renal function. Dr. Willem Kolff is considered the father of dialysis. This young Dutch physician constructed the first dialyzer (artificial kidney) in 1943. 

The mechanism of hemodialysis:

In hemodialysis, the wastes and excess water are removed by using an external filter called a dialyzer, which contains a semipermeable membrane. The separation of wastes is done by creating a counter-current flow gradient, where blood flow is in one direction and the fluid of the dialyzer is in the opposite direction. Peritoneal dialysis uses the peritoneum as a natural semipermeable membrane and removes waste and water into the dialysate (the material or fluid that passes through the membrane of the dialysis).
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