Monday, February 28, 2011

Leishmaniasis


Leishmaniasis

Causes, incidence, and risk factors

There are different forms of leishmaniasis.
·                 Cutaneous leishmaniasis affects the skin and mucus membranes. Skin sores usually start at the site of the sandfly bite. They can last for months or years before healing on their own. In a few people, sores may develop on mucus membranes.
·                 Systemic, or visceral leishmaniasis affects the entire body. This form occurs 2 - 8 months after a person is bitten by the sandfly. Most people do not remember having a skin sore. This form can lead to deadly complications. The parasites damage the immune system by decreasing the numbers of disease-fighting cells.
Cases of leishmaniasis have been reported on all continents except Australia and Antarctica. In the Americas, leishmaniasis can be found in Mexico and South America. Leishmaniasis has been reported in military personnel returning from the Persian Gulf.

Symptoms

Cutaneous leishmaniasis affects the skin and sometimes the mucus membranes. Symptoms may include:
·                 Skin sores, which may become a skin ulcer that heals very slowly
·                 Ulcers and wearing away (erosion) in the mouth, tongue, gums, lips, nose, and inner nose
·                 Stuffy nose, runny nose, and nosebleeds
·                 Breathing difficulty
·                 Swallowing difficulty
Systemic visceral infection in children usually begins suddenly with vomiting, diarrhea, fever, and cough. Adults usually have a fever for 2 weeks to 2 months, along with symptoms such as fatigue, weakness, and appetite loss. Weakness increases as the disease gets worse.
Other symptoms of systemic visceral leishmaniasis may include:
·                 Belly area (abdominal) discomfort
·                 Cough (children)
·                 Diarrhea (children)
·                 Fever that lasts for weeks; may come and go in cycles
·                 Night sweats
·                 Scaly, gray, dark, ashen skin
·                 Thinning hair
·                 Vomiting (children)
·                 Weight loss

Signs and tests

A physical exam may show signs of an enlarged spleen, liver, and lymph nodes. The patient may have been bitten by sandflies, or was in an area known for leishmaniasis.
Tests that may be done to diagnose the condition include:
·                 Biopsy of the spleen and culture
·                 Bone marrow biopsy and culture
·                 Direct agglutination assay
·                 Indirect immunofluorescent antibody test
·                 Lymph node biopsy and culture
·                 Montenegro skin test
·                 Skin biopsy
Other tests that may be done include:
·                 Complete blood count
·                 Serum immunoglobulin levels
·                 Serum protein
·                 Serum albumin
·                 Serologic testing

Treatment

Medicines called antimony-containing compounds are the main drugs used to treat leishmaniasis. These include:
·                 Meglumine antimonate
·                 Sodium stibogluconate
Other drugs that may be used include:
·                 Amphotericin B
·                 Fluconazole
·                 Pentamidine
Plastic surgery may be needed to correct the disfigurement caused by sores on the face (cutaneous leishmaniasis). Patients with drug-resistant viral leishmaniasis may need to have their spleen removed (splenectomy).


Thursday, February 17, 2011

Measles


  Measles

      Measles is best known for causing a rash in childhood, but measles can affect other parts of the body and sometimes occurs in adults. Vaccination has significantly reduced the number of cases in the United States, although isolated outbreaks continue to occur.
There are two types of measles, each caused by a different virus. Although both produce a rash and fever, they are really different diseases:
·                           The rubeola virus causes "red measles," also known as "hard measles" or just "measles." Although most people recover without problems, rubeola can lead to pneumonia or inflammation of the brain (encephalitis).

·                           The rubella virus causes "German measles," also known as "three-day measles." This is usually a milder disease than red measles. However, this virus can cause significant birth defects if an infected pregnant woman passes the virus to her unborn child.

Measles Symptoms

Rubeola ("red measles" or "hard measles")
Symptoms appear about 10-14 days after a person is infected with the rubeola virus. This is called the incubation period. During this period, the virus is multiplying. Symptoms occur in two phases.
·                           The early phase begins with these symptoms:

o                                           Fever

o                                           A run-down feeling

o                                           Cough

o                                           Red eyes

o                                           Runny nose

o                                           Loss of appetite

·                           The red measles rash develops from two to four days later.

o                                           The rash usually starts on the face, spreading to the trunk and then to the arms and legs.

o                                           The rash is initially small red bumps that may blend into each other as more appear. From a distance, the rash often looks uniformly red.

o                                           People with measles may develop small grayish spots on the inside of the cheek, called "Koplik spots."

o                                           The rash is usually not itchy, but as it clears up, the skin may shed (this looks like skin that is peeling after sunburn).

o                                           Although red measles is usually a mild disease, a few serious complications may occur. Red measles makes patients more vulnerable to pneumonia and bacterial ear infections. Pneumonia as a complication of measles is especially serious in infants and is responsible for most deaths in this age group. Inflammation of the brain (encephalitis) occurs about once in every thousand cases and is a serious complication that can be fatal.

o                                           Red measles is particularly severe in patients with weakened immune systems, including people who are malnourished or have HIV.
Rubella ("German measles")
German measles causes milder symptoms than red measles. The incubation period between getting the virus and getting sick is 10 days to two weeks.
·                           Initially, some people experience fatigue, low-grade fever, headache, or red eyes several days before the rash appears. These symptoms are more common in adults than in children.

·                           Swollen, tender lymph nodes may occur in the back of the neck.

·                           The rash is light red to pink. It starts as individual spots which may merge together over time. The rash usually starts on the face and moves down to the trunk.

·                           The rash does not usually itch, but as it clears up, the skin may shed.

·                           Adult women who get rubella may get painful joints for days to weeks after the infection. This affects the hands, wrists, and knees.

·                           Symptoms may be so mild that they are not even noticed, especially in children. Most symptoms resolve in a few days, but swollen lymph nodes may persist for a few weeks.

·                           The most feared complication of rubella is "congenital rubella," which occurs when an infected pregnant woman passes the virus to her unborn child. Among other problems and birth defects, affected infants may have cataracts, heart defects, hearing impairment, and learning disabilities. The risk of transmission is highest early in pregnancy. The virus may also causemiscarriage or stillbirth.

Measles Treatment

Self-Care at Home

Although there is no cure for measles, there are steps that can make the disease more tolerable. These include the following:
·                           Get plenty of rest.
·                           Sponge baths with lukewarm water may reduce discomfort due to fever.
·                          Drink plenty of fluids to help avoiddehydration.
·                           A humidifier or vaporizer may ease the cough.
·                           Pain relievers and fever reducers such as acetaminophen (Tylenol, Liquiprin Drops, and other brands) and ibuprofen (Advil, Motrin and other brands) can help with symptoms when used according to directions. Remember never to give aspirin to children or teenagers because it may cause a disease known as Reye syndrome.

Medical Treatment

There is no specific treatment or cure for measles. Children should stay at home and out of school until they are cleared to return by their health-care provider.


Mumps


 Mumps

It is an infection caused by the mumps virus.

Symptoms of mumps

The most common symptoms are fever, headache, muscle aches, tiredness andloss of appetite followed by onset of parotitis (swollen and tender salivary glands under the ears -- on one or both sides).

 Symptoms

Symptoms typically appear 16-18 days after infection, but this period can range from 12-25 after infection.

 Mumps spread

Mumps is spread by mucus or droplets from the nose or throat of an infected person, usually when a person coughs or sneezes. Surfaces of items (e.g. toys) can also spread the virus if someone who is sick touches them without washing their hands, and someone else then touches the same surface and then rubs their eyes, mouth, nose etc. (this is called fomite transmission).

 Treatment 

There is no specific treatment. Supportive care should be given as needed. If someone becomes very ill, they should seek medical attention. If someone seeks medical attention, they should call their doctor in advance so that they don't have to sit in the waiting room for a long time and possibly infect other patients.


Sore throat


 Sore throat

A sore throat can have many causes including:
  1. Common viruses, and even the viruses that causemononucleosis (mono) and the flu, can cause a sore throat. Some viruses can also produce blisters in the mouth and throat ("aphthous stomatitis").
  2. Breathing through the mouth can produce throat dryness and soreness.
  3. Sinus drainage (post nasal drip) may cause a sore throat.
  4. A sore throat can also be caused by bacteria. The two most common bacteria to cause a sore throat areStreptococcus (which causesstrep throat) andArcanobacterium haemolyticum.Arcanobacterium causes sore throats mainly in young adults and is sometimes associated with a fine redrash.
  5. Sore throat appearing after treatment with antibiotics,chemotherapy, or other immune-compromising medications may be due toCandida, commonly known as "thrush."
  6. A sore throat lasting for more than two weeks can be a sign of a serious illness, such as throat cancer or AIDS.

What can I do at home for a sore throat?

Generally, sore throats must run their course (exception, strep throat will be addressed below.)
·                          Salt water gargles, hard candies, sprays for example, Chloraseptic) and lozenges can provide temporary pain relief. (Caution: Lozenges and hard candy are a choking hazard for children. Avoid their use in young children.) 
·                          A humidifier may be helpful in relieving symptoms, especially in sore throats caused by mouth breathing and dry air. 
·                          Acetaminophen or ibuprofen may help control the pain. 
·                          For adults, if your nose is plugged, nasal sprays such as Afrin may be used for two to three days to prevent mouth breathing. It is NOT a good idea to use these products for more than a couple of days; you may become dependent on them. 
·                          Other decongestant products, such as Sudafed, may be helpful. 

Medical care 

Seek medical care:
  1. If you have been in contact with someone with strep throat and you have a sore throat, it is reasonable to have a strep test done.
  2. If your sore throat is associated with a fever, swollen "glands" (lymph nodes), or white patches on the back of your throat.
  3. If your sore throat is not associated with other cold symptoms (runny nose, watery eyes, sinus congestion).
  4. Any sore throat that has a sudden onset and is associated with a fever.
  5. If you are having trouble swallowing liquids (pain with swallowing is to be expected with a sore throat).
  6. If your sore throat persists for more than a week.
  7. If you have a sore throat and the front of your neck is sore and stiff.

Wednesday, February 16, 2011

Kidney Structure



     One of the most complex, beautifully “engineered” organs of the human body, the kidneys perform several essential tasks including the excretion of waste products, the maintenance of homeostatic balance in the body and the release of important hormones. To achieve this, human kidneys have a highly developed, superbly refined anatomy and physiology.

Location and Basic Structure of the Kidneys

The kidneys are located near the vertebral column at the small of the back; the left kidney lying a little higher than the right. Each is identical in structure and function. They are bean-shaped, about 10 cm long and 6.5 cm wide. Each kidney comprises an outer cortex and an inner medulla. The kidney is supplied with oxygenated blood via the renal artery and drained of deoxygenated blood by the renal vein. In addition, urine produced by the kidney as part of its excretory function, drains out via narrow “tubules” and the ureter, in turn connected to the bladder.

The Nephron

The main functional unit of the kidney is the nephron. There are approximately one million nephrons per kidney. The role of nephrons is to make urine by:
  • Filtering blood of small molecules and ions such as water, salt, glucose and other solutes including urea. Large “macromolecules” like proteins are untouched.
  • Recycling the required quantities of useful solutes which then re-enter the bloodstream. (A process called reabsorption)
  • Allowing surplus or waste molecules/ions to flow from the tubules/ureter as urine.

Filtration and Reabsorbtion in the Kidneys

During progress through the nephron, some solutes like sodium chloride, potassium and glucose are reabsorbed, along with water, back into the bloodstream. This maintains a correct balance of these chemicals within the blood, assisting blood pressure regulation, for example. The filtration and reabsorbtion of glucose within the kidneys also helps to maintain correct levels of vital blood sugars. When this regulation breaks down very serious health consequences can follow.
Urea and uric acid are nitrogen containing waste products from metabolic processes in the body. These substances are potentially toxic and are partially excreted by the kidneys to maintain good health. Interestingly, of the filtrate which enters each nephron from the blood, only about 1% actually leaves the body as urine because of the various reabsorbtion mechanisms driven by osmosis, diffusion, and active transport.

Tubular Secretion in the Kidneys

Another, less familiar, mechanism for urine production in the kidneys is tubular secretion. Specialised cells move solutes directly from the blood into the tubular fluid. For example, hydrogen and potassium ions are secreted directly into the tubular fluid. This process is “coupled” or balanced by the re-uptake of sodium ions back into the blood.

Tubular secretion of hydrogen ions, augmented by control of bicarbonate levels, is important in maintaining correct blood pH. When the blood is too acidic (acidosis) more hydrogen ions are secreted. If the blood becomes too alkaline (alkalosis), hydrogen secretion is reduced. In maintaining blood pH within normal limits (about 7.35–7.45) the kidney can produce urine with pH as low as that of acid rain or as alkaline as baking soda!

The Kidney as an Endocrine Gland

In addition to its excretory and homeostatic roles, the kidneys also release two important hormones into the blood. These are:
  • Erythropoietin which acts on bone marrow to increase the production of red blood cells
  • Calcitriol which promotes the absorption of calcium from food in the intestine and acts directly on bones to shift calcium into the bloodstream.
Finally the kidney produces the enzyme renin, an important regulator of blood pressure.


Kidney stone


Kidney stone     
    A kidney stone is a solid mass made up of tiny crystals. One or more stones can be in the kidney or ureter at the same time.
See also: Cystinuria

Causes, incidence, and risk factors

Kidney stones can form when urine contains too much of certain substances. These substances can create small crystals that become stones.
The biggest risk factor for kidney stones is dehydration.
Kidney stones may not produce symptoms until they begin to move down the tubes (ureters) through which urine empties into the bladder. When this happens, the stones can block the flow of urine out of the kidneys. This causes swelling of the kidney or kidneys, causing pain. The pain is usually severe.
Kidney stones are common. A person who has had kidney stones often gets them again in the future. Kidney stones often occur in premature infants.
Some types of stones tend to run in families. Certain kinds of stones can occur with bowel disease, ileal bypass for obesity, or renal tubule defects.
There are different types of kidney stones. The exact cause depends on the type of stone.
·                 Calcium stones are most common. They occur more often in men than in women, and usually appear between ages 20 - 30. They are likely to come back. Calcium can combine with other substances, such as oxalate (the most common substance), phosphate, or carbonate to form the stone. Oxalate is present in certain foods. Diseases of the small intestine increase the risk of forming calcium oxalate stones.
·                 Cystine stones can form in people who have cystinuria. This disorder runs in families and affects both men and women.
·                 Struvite stones are mostly found in women who have a urinary tract infection. These stones can grow very large and can block the kidney, ureter, or bladder.
·                 Uric acid stones are more common in men than in women. They can occur with goutor chemotherapy.
Other substances also can form stones.

Symptoms

The main symptom is severe pain that starts suddenly and may go away suddenly:
·                 Pain may be felt in the belly area or side of the back
·                 Pain may move to groin area (groin pain) or testicles (testicle pain)
Other symptoms can include:
·                 Abnormal urine color
·                 Blood in the urine
·                 Chills
·                 Fever
·                 Nausea
·                 Vomiting

Treatment

The goal of treatment is to relieve symptoms and prevent further symptoms. (Kidney stones that are small enough usually pass on their own.) Treatment varies depending on the type of stone and how severe the symptoms are. People with severe symptoms might need to be hospitalized.
When the stone passes, the urine should be strained and the stone saved and tested to determine the type.
Drink at least 6 - 8 glasses of water per day to produce a large amount of urine. Some people might need to get fluids through a vein (intravenous).
Pain relievers can help control the pain of passing the stones (renal colic). For severe pain, you may need to take narcotic pain killers or nonsteroidal anti-inflammatory drugs (NSAIDS) such as ibuprofen.
Depending on the type of stone, your doctor may prescribe medicine to decrease stone formation or help break down and remove the material that is causing the stone. Medications can include:
·                 Allopurinol (for uric acid stones)
·                 Antibiotics (for struvite stones)
·                 Diuretics
·                 Phosphate solutions
·                 Sodium bicarbonate or sodium citrate (which make the urine more alkaline)
Surgery is usually needed if:
·                 The stone is too large to pass on its own
·                 The stone is growing
·                 The stone is blocking urine flow and causing an infection or kidney damage
Today, most treatments are much less invasive than in the past.
·                 Extracorporeal shock-wave lithotripsy is used to remove stones slightly smaller than a half an inch that are located near the kidney. This method uses ultrasonic waves or shock waves to break up stones. Then, the stones leave the body in the urine.
·                 Percutaneous nephrolithotomy is used for large stones in or near the kidney, or when the kidneys or surrounding areas are incorrectly formed. The stone is removed with an endoscope that is inserted into the kidney through a small opening.
·                 Ureteroscopy may be used for stones in the lower urinary tract.
·                 Standard open surgery (nephrolithotomy) may be needed if other methods do not work or are not possible.