Binding and Fusion: HIV begins its life cycle
when it binds to a CD4 receptor and one of two
co-receptors on the surface of a CD4+
Tlymphocyte. The virus then fuses with the host
cell. After fusion, the virus releases RNA, its
genetic material, into the host cell.

Reverse Transcription: An HIV enzyme
called reverse transcriptase converts the singlestranded HIV RNA to double-stranded HIV DNA.

Integration: The newly formed HIV DNA
enters the host cell's nucleus, where an HIV
enzyme called integrase "hides" the HIV DNA
within the host cell's own DNA. The integrated
HIV DNA is called provirus. The provirus may
remain inactive for several years, producing few or
no new copies of HIV

Transcription: When the host cell receives a
signal to become active, the provirus uses a host
enzyme called RNA polymerase to create copies of
the HIV genomic material, as well as shorter
strands of RNA called messenger RNA (mRNA).
The mRNA is used as a blueprint to make long
chains of HIV proteins.

Assembly: An HIV enzyme called protease cuts
the long chains of HIV proteins into smaller
individual proteins. As the smaller HIV proteins
come together with copies of HIV's RNA genetic
material, a new virus particle is assembled.

Budding: The newly assembled virus pushes out
("buds") from the host cell. During budding, the new
virus steals part of the cell's outer envelope. This
envelope, which acts as a covering, is studded with
protein/sugar combinations called HIV
glycoproteins. These HIV glycoproteins are
necessary for the virus to bind CD4 and coreceptors. The new copies of HIV can now move
on to infect other cells.

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Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart. In healthy adults, there are two normal heart sounds often described as a lub and a dub (or dup), that occur in sequence with each heartbeat. These are the first heart sound (S1) and second heart sound (S2), produced by the closing of the atrioventricular valves and semilunar valves, respectively. In addition to these normal sounds, a variety of other sounds may be present including heart murmurs, adventitious sounds, and gallop rhythms S3 and S4.

Learn about Bicuspid Aortic Valves in this presentation. Bicuspid Aortic Valves are present in about 2% of the population and are the most common congenital disorder. Find out more about a Bicuspid Aortic Valve by visiting the following link:

The condition is caused by a blockage in the lymphatic system, part of the immune and circulatory systems. Lymphedema is most commonly caused by lymph node removal or damage due to cancer treatment. The main symptom is swelling in an arm or leg that may be accompanied by pain or discomfort. Exercise, wrapping, massage, and compression can help.

Expand Section. Pulmonary edema is often caused by congestive heart failure. When the heart is not able to pump efficiently, blood can back up into the veins that take blood through the lungs. As the pressure in these blood vessels increases, fluid is pushed into the air spaces (alveoli) in the lungs.

Arteriosclerosis occurs when the blood vessels that carry oxygen and nutrients from your heart to the rest of your body (arteries) become thick and stiff — sometimes restricting blood flow to your organs and tissues. Healthy arteries are flexible and elastic, but over time, the walls in your arteries can harden, a condition commonly called hardening of the arteries. Atherosclerosis is a specific type of arteriosclerosis, but the terms are sometimes used interchangeably. Atherosclerosis refers to the buildup of fats, cholesterol and other substances in and on your artery walls (plaques), which can restrict blood flow. These plaques can burst, triggering a blood clot. Although atherosclerosis is often considered a heart problem, it can affect arteries anywhere in your body. Atherosclerosis may be preventable and is treatable.

Uterine rupture is usually when the scar from your previous caesarean section tears open. Though it's uncommon, you should be aware of this risk, particularly if you're thinking about giving birth vaginally next time. It's possible for your scar to gape slightly while you're pregnant (scar dehiscence).

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The term subclavian steal describes retrograde blood flow in the vertebral artery associated with proximal ipsilateral subclavian artery stenosis or occlusion, usually in the setting of subclavian artery occlusion or stenosis proximal to the origin of the vertebral artery. Alternatively, innominate artery disease has also been associated with retrograde flow in the ipsilateral vertebral artery, particularly where the subclavian artery origin is involved. Subclavian steal is frequently asymptomatic and may be discovered incidentally on ultrasound or angiographic examination for other indications, or it may be prompted by a clinical examination finding of reduced unilateral upper limb pulse or blood pressure. In some cases, patients may develop upper limb ischemic symptoms due to reduced arterial flow in the setting of subclavian artery occlusion, or they may develop neurologic symptoms due to posterior circulation ischemia associated with exercise of the ipsilateral arm.[1] Treatment has traditionally consisted of open subclavian artery revascularization, typically via carotid-subclavian bypass or subclavian artery transposition, which are generally durable procedures. Newer, less invasive options include endovascular intervention with recanalization as appropriate and angioplasty and stenting if required. The clinical relevance of subclavian steal was described in 1961 by Reivich, Holling and Roberts; however, the recognition of retrograde vertebral artery flow dates back another 100 years to Harrison and Smyth. Some papers, including a previous version of this article, advocate restricting the term subclavian steal to patients with neurologic symptoms only, but this is incorrect in view of the substantial literature using this term to describe the hemodynamic scenario of retrograde vertebral flow and proximal subclavian artery disease.

Paget's disease of bone disrupts your body's normal bone recycling process, in which old bone tissue is gradually replaced with new bone tissue. Over time, the affected bones may become fragile and misshapen. Paget's disease of bone most commonly occurs in the pelvis, skull, spine and legs.

Ear Infection Drainage Time Lapse Video

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Vertigo is a sensation of spinning. If you have these dizzy spells, you might feel like you are spinning or that the world around you is spinning. Causes of Vertigo Vertigo is often caused by an inner ear problem. Some of the most common causes include: BPPV. These initials stand for benign paroxysmal positional vertigo. BPPV occurs when tiny calcium particles (canaliths) clump up in canals of the inner ear. The inner ear sends signals to the brain about head and body movements relative to gravity. It helps you keep your balance. BPPV can occur for no known reason and may be associated with age. Meniere's disease. This is an inner ear disorder thought to be caused by a buildup of fluid and changing pressure in the ear. It can cause episodes of vertigo along with ringing in the ears (tinnitus) and hearing loss. Vestibular neuritis or labyrinthitis. This is an inner ear problem usually related to infection (usually viral). The infection causes inflammation in the inner ear around nerves that are important for helping the body sense balance

Electrical injuries can present with a variety of problems, including cardiac or respiratory arrest, coma, blunt trauma, and severe burns of several types. It is important to establish the type of exposure (high or low voltage), duration of contact, and concurrent trauma. Low-voltage AC injury without loss of consciousness and/or arrest These injuries are exposures of less than 1000V and usually occur in the home or office setting. Typically, children with electrical injuries present after biting or chewing on an electrical cord and suffer oral burns. Adults working on home appliances or electrical circuits can also experience these electrical injuries. Low-voltage AC may result in significant injury if there is prolonged, tetanic muscle contraction. Low-voltage AC injury with loss of consciousness and/or arrest In respiratory arrest or ventricular fibrillation that is not witnessed, an electrical exposure may be difficult to diagnose. All unwitnessed arrests should include this possibility in the differential diagnosis. Query EMS personnel, family, and coworkers about this possibility. Inquire if a scream was heard before the patient’s collapse; this may be due to involuntary contraction of chest wall muscles from electrical current. High-voltage AC injury without loss of consciousness and/or arrest Usually high-voltage injuries do not cause loss of consciousness but instead cause devastating thermal burns. In occupational exposures, details of voltage can be obtained from the local power company. High-voltage AC injury with loss of consciousness and/or arrest This is an unusual presentation of high-voltage AC injuries, which do not often cause loss of consciousness. History may need to come from bystanders or EMS personnel. Direct current (DC) injury These injuries typically cause a single muscle contraction that throws the victim away from the source. They are rarely associated with loss of consciousness unless there is severe head trauma, and victims can often provide their own history. Conducted electrical devices Conducted electrical weapons (CEWs) such as tasers are weapons used by law enforcement that deliver high-voltage current that is neither true AC or DC but is most like a series of low-amplitude DC shocks.[16] They can deliver 50,000 V in a 5-second pulse, with an average current of 2.1 mA.[17] Though they have been temporally associated with deaths in the law enforcement setting, conducted electrical devices (CEDs) in healthy volunteers have been shown to be safe without evidence of delayed arrhythmia or cardiac damage as measured by troponin I.[18, 17] One study of their use in 1201 law enforcement incidents showed mostly superficial puncture wounds from the device probes, and significant injuries only from trauma subsequent to shock, not from the device itself. Of 2 deaths in custody, neither was related to CEW exposure.[19]

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A central venous catheter, also called a central line, is a long, thin, flexible tube used to give medicines, fluids, nutrients, or blood products over a long period of time, usually several weeks or more. A catheter is often inserted in the arm or chest through the skin into a large vein.

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this animated surgery showing management of bone defects with the Precice Lengthening-Compression IM nail