Tag Archives: Disinfectant

PUVA therapy

Description:
PUVA is an acronym. The P stands for psoralen,(Psoralen is a photosensitizing agent found in plants ) the U for ultra, the V for violet, and the A for that portion of the solar spectrum between 320 and 400 nanometers in wavelength. Psoralens are chemicals found in certain plants that have the ability to absorb ultraviolet light in these wavelengths. Once the light energy is absorbed, these chemicals are energized to interact with DNA, ultimately inhibiting cell multiplication, which is their presumed mode of action.

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Certain skin diseases are characterized by cells that are rapidly multiplying. Inhibiting this unrestrained multiplication can be useful in treating these diseases. So PUVA is a combination of an oral drug and subsequent ultraviolet light exposure. The treatment may affect certain blood cells and skin cells so that the skin disease improves.

It is a treatment for eczema, psoriasis, graft-versus-host disease, vitiligo, mycosis fungoides, large-plaque parapsoriasis and cutaneous T-cell lymphoma using the sensitizing effects of the drug psoralen. The psoralen is applied or taken orally to sensitize the skin, then the skin is exposed to UVA.

Photodynamic therapy is the general use of nontoxic light-sensitive compounds that are exposed selectively to light, whereupon they become toxic to targeted malignant and other diseased cells. Still, PUVA therapy is often classified as a separate technique from photodynamic therapy.

Plant sources   from where  we get psoralens:
Ficus carica (fig) is probably the most abundant source of psoralens. They are also found in small quantities in Ammi visnaga (bisnaga), Pastinaca sativa (parsnip), Petroselinum crispum (parsley), Levisticum officinale (lovage), Foeniculum vulgare (fruit, i.e., fennel seeds), Daucus carota (carrot), Psoralea corylifolia (babchi), and Apium graveolens (celery).

Types of PUVA therapy:
The most common form of therapy combines 8-methoxypsoralen taken by mouth followed 45-60 minutes later by exposure of the skin to UVA. Less commonly the drug is applied topically (the medication is occasionally diluted in bathtub water in which the patient is immersed) and then after a few minutes the ultraviolet exposure occurs.

Procedure:
Psoralens are taken systemically or can be applied directly to the skin. The psoralens allow a relatively lower dose of UVA to be used. When they are combined with exposure to UVA in PUVA, they are highly effective at clearing psoriasis and vitiligo. Like UVB light treatments, the reason remains unclear, though investigators speculate there may be similar effects on cell turnover and the skin’s immune response.

Choosing the proper dose for PUVA is similar to the procedure followed with UVB. The physician can choose a dose based on the patient’s skin type. The dose will increase in every treatment until the skin starts to respond.

Some clinics test the skin before the treatments, by exposing a small area of the patient’s skin to UVA, after ingestion of psoralen. The dose of UVA that produces uniform redness 72 hours later, called the minimum phototoxic dose (MPD), becomes the starting dose for treatment.

At the very least for vitiligo, narrowband ultraviolet B (UVB) phototherapy is now used more commonly than PUVA since it does not require the use of the Psoralen. As with PUVA, treatment is carried out twice weekly in a clinic or every day at home, and there is no need to use psoralen.

Narrowband UVB does not cure the legs and hands, compared to the face and neck. To the hands and legs PUVA may be more effective. The reason can be because UVA penetrates deeper in the skin, and the melanocytes in the skin of the hands and legs is deeper in the skin. The Narrowband UVB does not reach the melanocytes.

How maney PUVA  therapy is required:
There ought to be a significant improvement in the patient’s skin disease after about 15 treatments. Treatments are given no sooner than 48 hours apart because the burn induced by PUVA is often delayed for as long as two days (unlike ordinary sunburns). Unless there is a problem, the amount of energy administered to the patient is increased appropriately at each visit depending on the patient’s coloration. After about 30 treatments, a decision is made as to whether to continue treatments. PUVA is not always effective. If there is no improvement after these treatments, it is probably unlikely that continuing this form of treatment is worthwhile. On the other hand, if significant clearing has occurred, it is probably prudent to decrease the frequency of treatments in order to maintain the improvement. Since there is a relationship between the amount of light energy administered and the degree of photo-aging and the induction of skin cancers, it is wise to limit the light exposures as appropriate.

Advantages:
The major advantage to PUVA is that it is an effective therapy that becomes active only at the site of the disease, the skin. It can be used to treat large areas of skin, and the fact that the drug is only activated in the presence of UV light implies that it may be less toxic than other therapies that require systemic administration and whose effects are not localized to just the skin.

PUVA must be administered in a physician’s office under the control of a medical professional so it requires repeated visits to the office. PUVA may not cure psoriasis permanently so treatment can be required indefinitely.

Side effects and complications:
Some patients experience nausea and itching after ingesting the psoralen compound. For these patients PUVA bath therapy may be a good option.

Long term use of PUVA therapy has been associated with higher rates of skin cancer.

The most significant complication of PUVA therapy for psoriasis is squamous cell skin cancer. Two carcinogenic components of the therapy include the nonionizing radiation of UVA light as well as the psoralen intercalation with DNA. Both processes negatively contribute to genome instability.
History  :  Psoralens have been known since ancient Egypt but have only been available in a chemically synthesized form since the 1970s.

Resources:
http://en.wikipedia.org/wiki/PUVA_therapy
http://www.medicinenet.com/puva_therapy_photochemotherapy/article.htm

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Propolis,The Bee Product have Beneficial Effects For Health

Various products derived from the beehive have been studied and propolis has proved to be a product having beneficial results for human health.

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Propolis (Pro-before, Polis-city = defense of the city), is the resinous substance that bees gather from the leaf buds of trees and certain vegetables.

The bee gathers this and transforms it in order to disinfect the beehive, seal cracks, build panels, as well as using it as a microbiocidal agent, disinfectant and also for embalming intruders otherwise difficult to expel due to their size.

Propolis, thus, is directly responsible for guaranteeing the asepsis of the beehives, locations prone to developing viruses and bacteria, given their conditions of temperature and humidity.

Due to the great number of active ingredients present, tincture (alcoholic extract) of propolis is well known and used for its therapeutic properties, principally for its stimulant action on the organism’s defense system. Notable amongst its properties are its antioxidant and anti-microbial action, its activity as a stimulant and its healing, analgesic, anesthetic and anti-inflammatory activity.

To date, in the literature consulted, no antioxidant capacity values have been found greater than those obtained for propolis, for any of the products/foods analyzed, using this type of methodology.

Sources: Medical News Today October 28, 2009

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Percutaneous Transhepatic Cholangiography (PTCA)

 

Definition:

Percutaneous transhepatic cholangiography (PTHC or PTC) is a radiologic technique used to visualize the anatomy of the biliary tract. A contrast medium is injected into a bile duct in the liver, after which X-rays are taken. It allows access to the biliary tree in cases where endoscopic retrograde cholangiopancreatography (ERCP) has been unsuccessful. Initially reported in 1937, the procedure became popular after a 1952 report in the English-language literature.

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It is an x-ray test that can help show whether there is a blockage in the liver or the bile ducts that drain it. Since the liver and its drainage system do not normally show up on x-rays, the doctor doing the x-ray needs to inject a special dye directly into the drainage system of the liver. This dye, which is visible on x-rays, should then spread out to fill the whole drainage system. If it does not, that means there is a blockage. This type of blockage might result from a gallstone or a cancer in the liver.

It is predominatly now performed as a therapeutic technique. There are less invasive means of imaging the biliary tree including transabdominal ultrasound, MRCP, computed tomography and endoscopic ultrasound. If the biliary system is obstructed, PTC may be used to drain bile until a more permanent solution for the obstruction is performed (e.g. surgery). Additionally, self expanding metal stents can be placed across malignant biliary strictures to allow palliative drainage. Percutaneous placement of metal stents can be utilised when therapeutic ERCP has been unsuccessful, anatomy is altered precluding endoscopic access to the duodenum, or where there has been separation of the segmental biliary drainage of the liver, allowing more selective placement of metal stents. It is generally accepted that percutanous biliary procedures have higher complication rates than therapeutic ERCP. Complications encountered include infection, bleeding and bile leaks.
Why the test is performed?
Bile is a by-product of protein metabolism. It is created in the liver and excreted into the intestines via the bile ducts. If bile cannot be removed from the body, it collects in the blood and is seen as a yellow discoloration of the skin and eyes (jaundice).

Also, the pancreas creates digestive fluids which drain via a common bile duct into the intestine, and thus obstruction can prevent the drainage of the fluids and may cause pancreatitis (inflammation of the pancreas).

A PTCA test can help identify whether a blockage is causing the jaundice and pancreatitis.

How do you prepare for the test?
Tell your doctor if you have ever had an allergic reaction to lidocaine or the numbing medicine used at the dentist’s office. Also tell your doctor if you could be pregnant. If you have diabetes and take insulin, discuss this with your doctor before the test.

Most people need to have a blood test done some time before the procedure, to make sure they are not at high risk for bleeding complications. If you take aspirin, nonsteroidal anti-inflammatory drugs, or other medicines that affect blood clotting, talk with your doctor. It may be necessary to stop or adjust the dose of these medicines before your test.

You will be told not to eat anything on the morning of the test so that your stomach is empty. This is a safety measure in the unlikely case you have a complication, such as bleeding, that might require repair surgery.

What happens when the test is performed?
You lie on a table wearing a hospital gown. An IV (intravenous) line is inserted into a vein in case you need medicines or fluid during the procedure. An area over your right ribcage is cleaned with an antibacterial soap. Then the radiologist may take a picture of your abdomen with an overhead camera. Medicine is injected through a small needle to numb the skin and the tissue underneath the skin in the area where the dye is to be injected. You may feel some brief stinging from the numbing medicine.

A separate needle is then inserted between two of your ribs on your right side. A small amount of xray dye is injected, and some pictures are taken that are visible on a video screen. Your doctor adjusts the placement of the needle until it is clear that the dye is flowing easily through the ducts (drainage tubes) inside your liver.

Because taking the x-ray pictures sometimes requires a significant amount of time, the doctor replaces the needle with a softer plastic tube. First, the syringe holding the dye is detached from the top of the needle, leaving the needle in place. The doctor then gently pushes a thin wire through the needle and into the duct where the needle has been sitting. Next the needle is pulled out, sliding over the outside end of the wire. The wire is left with one end inside the liver to hold the position where the needle had been. A thin plastic tube similar to an IV line is slid along the wire, like a long bead on a string, until it is in the same place where the needle was. The wire is then pulled out, and the dye syringe is attached to the tube.

More dye is injected through the plastic tube, and pictures are taken with the video camera as the dye spreads inside the liver. If there is no blockage, the dye drains out of the liver through the bile ducts and begins to show up on the x-ray in the area of your small intestine. Once all of the needed pictures have been taken, the plastic tube is pulled out, and a small bandage is placed over your side. The whole test usually takes less than an hour.

Risk Factors:
It is possible to have serious bleeding from this test. In some cases, blood leaks to the outside surface of the liver and causes a buildup of blood there. In other cases, blood can leak directly into the liver’s drainage system, in which case it might start showing up in your intestine, causing a bloody bowel movement. It is less likely that you could develop an infection after the test. The only soreness you are likely to have is at the skin surface where the needle went in. This should last for only a day or two.

In rare cases, the dye used in the test can damage your kidneys. This kidney effect is almost always temporary, but some people have permanent damage.

As with all x-rays, there is a small exposure to radiation. In large amounts, exposure to radiation can cause cancers or (in pregnant women) birth defects. The amount of radiation from the video x-ray in this test is very small-too small to be likely to cause any harm. (The people performing the test on you will wear lead shields, since they would otherwise be exposed to this radiation over and over, which could be more of a danger.)

Must you do anything special after the test is over?
Call your doctor right away if you have pain in your right abdomen or shoulder, fever, dizziness, or a change in your stool color to black or red.

How long is it before the result of the test is known?
You may be told a few early results of your test as soon as the test is done. It takes a day or two for the radiologist to review the x-rays more thoroughly and to give your doctor a full report.

RESULTS:-

Normal Result:-The bile ducts are normal in size and appearance for the age of the patient.

Abnormal Results:-The results may show that the ducts are enlarged, which may indicate the ducts are blocked. The blockage may be caused by infection, scarring, or stones. It may also indicate cancer in the bile ducts, liver, pancreas, or region of the gallbladder.

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*Blocked bile ducts
*Cholangitis (infection in common bile duct)
Special considerations:-
A PTCA may be done if an endoscopic retrograde cholangiopancreatography ( ERCP) cannot be performed or has failed in the past.

An MRCP (magnetic resonance cholangiopancreatography) is a newer, non-invasive imaging method, based on MRI, which provides similar views of the bile ducts.

Resources:
https://www.health.harvard.edu/fhg/diagnostics/percutaneous-transhepatic-cholangiography.shtml
http://en.wikipedia.org/wiki/Percutaneous_transhepatic_cholangiography
http://www.healthline.com/adamcontent/percutaneous-transhepatic-cholangiogram

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Why You Want to Avoid Using Chemical Disinfectants

chemical disinfectantsChemicals used to kill bacteria could be making them stronger. Low levels of biocides, which are used in disinfectants and antiseptics to kill microbes, can make the potentially lethal bacterium Staphylococcus aureus remove toxic chemicals more efficiently, potentially making it resistant to being killed by some antibiotics.

Biocides are commonly used in cleaning hospitals and home environments, sterilizing medical equipment and decontaminating skin before surgery. At the correct strength, biocides kill bacteria and other microbes. But if lower levels are used, the bacteria can survive and become resistant to treatment.

Researchers exposed S. aureus taken from the blood of patients to low concentrations of several biocides. Exposure to low concentrations of a variety of biocides resulted in the appearance of resistant mutants.

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