the gout disease symptoms:
pain in the feet (usually at the corm of the foot) increases after wake up .
pain in the large finger of the foot.
Note:
if the patient have this symptoms and the UA analysis result is normal he must take the drug of gout disease.
Procedure:
1. Put 1 ml of the uric acid reagent in each of two small test tubes.
2. Withdraw 20µ of serum by micropipette and put them in one of the two tubes and sign it as test tube .
3. Withdraw 20µ of uric acid standard and put them in the other tube and sign it as standard tube .
4. Leave the two tubes in water bath for 5 minutes or in room temperature for 10 minutes .
5. Use the wave length 546 nm for measuring.
6. Put the standard and record the reading then put the tested serum and record the reading.
Calculation:
[The reading of test / The reading of standard ] * conc. of UA standard (usually 6 or 5 mg/dl) .
Normal values:
♂ : 3.4 – 7.0 mg/dl
♀ : 2.4 – 5.7 mg/dl
Nov 22, 2010
Creatinine analysis
Procedure:
-In Blood
Sample serum or plasma
The reagent usually must be prepared before use according to kits of the chemicals.
1.put 1 ml of working reagent in two test tubes.
2.put 100 µ of serum in one tube and read after exact 30 sec. abs1 at wave length 500 then wait for additional 2 minutes and read again abs2.
3.put 100 µ of standard in the other tube read after exact 30 sec. abs1 then wait for additional 2 minutes and read again abs2.
Calculation:
abs of sample (abs2 - abs1) / abs of standard (abs2 - abs1) * 2 = .......mg / dl
-In urine
the urine must be collected for 24 hrs. then take 1ml urine and put on it 49 ml water then take from the solution 100 µ and repeat as shown above
Calculation:
abs of sample / abs of standard * 100 = ....... mg / dl.
Normal values
in serum or plasma 0.6 - 1.4 mg / dl
in urine 1 - 1.5 mg / dl
-In Blood
Sample serum or plasma
The reagent usually must be prepared before use according to kits of the chemicals.
1.put 1 ml of working reagent in two test tubes.
2.put 100 µ of serum in one tube and read after exact 30 sec. abs1 at wave length 500 then wait for additional 2 minutes and read again abs2.
3.put 100 µ of standard in the other tube read after exact 30 sec. abs1 then wait for additional 2 minutes and read again abs2.
Calculation:
abs of sample (abs2 - abs1) / abs of standard (abs2 - abs1) * 2 = .......mg / dl
-In urine
the urine must be collected for 24 hrs. then take 1ml urine and put on it 49 ml water then take from the solution 100 µ and repeat as shown above
Calculation:
abs of sample / abs of standard * 100 = ....... mg / dl.
Normal values
in serum or plasma 0.6 - 1.4 mg / dl
in urine 1 - 1.5 mg / dl
Urea
Procedure :
1.prepare two test tubes mark one as test tube and the other is standard tube .
2.in standard tube put : 1 ml buffer + one drop urease (R2) + 10 µ standard reagent (R1) leave for 5 min. in room temp.
3.in test tube put at same time : 1 ml buffer + one drop urease (R2) + 10 µ serum or plasma then leave for 5 min in room temp.
4.then put 200 µ of Reagent 4 (R4) and leave for 5 min. in water bath or 10 min. in room temp.
5.Measure at 580 wave length.
Calculation :
[ reading test / reading standard ] x 50 =.......mg / dl . OR [ reading test / reading standard ] x 8.33 =......mmol /l
Normal values:
15 - 45 mg / dl.
OR
2.5 - 7.5 mmol / l.
1.prepare two test tubes mark one as test tube and the other is standard tube .
2.in standard tube put : 1 ml buffer + one drop urease (R2) + 10 µ standard reagent (R1) leave for 5 min. in room temp.
3.in test tube put at same time : 1 ml buffer + one drop urease (R2) + 10 µ serum or plasma then leave for 5 min in room temp.
4.then put 200 µ of Reagent 4 (R4) and leave for 5 min. in water bath or 10 min. in room temp.
5.Measure at 580 wave length.
Calculation :
[ reading test / reading standard ] x 50 =.......mg / dl . OR [ reading test / reading standard ] x 8.33 =......mmol /l
Normal values:
15 - 45 mg / dl.
OR
2.5 - 7.5 mmol / l.
Nov 18, 2010
Brucellosis
Definition:
Brucellosis is a serious bacterial disease that causes fever, joint pain and fatigue. Brucella, the bacteria that cause brucellosis, spread from animals to people, often via unpasteurized milk, cheese and other dairy products.
Also known as Mediterranean fever or undulant fever, brucellosis is uncommon in the United States. Worldwide, brucellosis affects hundreds of thousands of people and animals in Mediterranean countries and other areas each year. The bacteria can spread through the air or through direct contact with infected animals.
Brucellosis can usually be treated successfully with antibiotics. Treatment takes several weeks, however, and relapses are common. Avoiding unpasteurized dairy products and taking precautions when working with animals or in a laboratory can help prevent brucellosis. Animals can be vaccinated against the disease.
Symptoms
Symptoms of brucellosis may show up anytime from a few days to a few months after you're infected with brucella, the bacteria that cause brucellosis. Signs and symptoms are similar to those of the flu and include:
- Fever, often rising to 104 F (40 C) or more in the afternoon — a rising and falling (undulating) fever is one of the hallmarks of the disease
- Chills
- Sweats
- Weakness
- Fatigue
- Joint, muscle and back pain
- Headache
Brucellosis symptoms may disappear for weeks or months and then return. In some people, brucellosis becomes chronic, with symptoms persisting for years, even after treatment. Long-term signs and symptoms include fatigue, fevers, arthritis and spondylitis — an inflammatory arthritis that affects the spine and nearby joints.
When to see a doctor
Brucellosis can be hard to identify, especially in the early stages, when it often resembles the flu. See your doctor if you develop a rapidly rising fever, muscle aches or unusual weakness and have any risk factors for the disease, or if you have a persistent fever.
Brucellosis can be hard to identify, especially in the early stages, when it often resembles the flu. See your doctor if you develop a rapidly rising fever, muscle aches or unusual weakness and have any risk factors for the disease, or if you have a persistent fever.
Causes:
Brucellosis affects many wild and domestic animals. Cattle, goats, sheep, pigs, dogs, camels, wild boar and reindeer are especially prone to the disease. A form of brucellosis also affects harbor seals, porpoises and certain whales.
At least six species or strains of bacteria cause brucellosis in animals, but not all produce illness in humans. The bacteria spread from animals to people in three main ways:
- Raw dairy products. Brucella bacteria in the milk of infected animals can spread to humans in unpasteurized milk, ice cream, butter and cheeses. The bacteria can also be transmitted in raw or undercooked meat from infected animals.
- Inhalation. Brucella bacteria spread easily in the air. Farmers, laboratory technicians and slaughterhouse workers can inhale the bacteria.
- Direct contact. Bacteria in the blood, semen or placenta of an infected animal can enter your bloodstream through a cut or other wound. Because normal contact with animals — touching, brushing or playing — doesn't cause infection, people rarely get brucellosis from their pets. Even so, people with weakened immune systems should avoid handling dogs known to have the disease.
Brucellosis normally doesn't spread from person to person, but in a few cases, women have passed the disease to their infants during birth or through their breast milk. Rarely, brucellosis may spread through sexual activity or through contaminated blood or bone marrow transfusions.
Complications
By Mayo Clinic staff Brucellosis can affect almost any part of your body, including your reproductive system, liver, heart and central nervous system. Chronic brucellosis may cause complications in just one organ or throughout your body. Possible complications include:
- Infection of the heart's inner lining (endocarditis). This is one of the most serious complications of brucellosis. Untreated endocarditis can damage or destroy the heart valves and is the leading cause of brucellosis-related deaths.
- Arthritis. Osteoarthritis is marked by pain, stiffness and swelling in your joints, especially the knees, hips, ankles, wrists and spine. Spondylitis — inflammation of the joints between the bones (vertebrae) of your spine or between your spine and pelvis — can be particularly hard to treat and may cause lasting damage.
- Inflammation and infection of the testicles (epididymo-orchitis). The bacteria that cause brucellosis can infect the epididymis, the coiled tube that connects the vas deferens and the testicle. From there, the infection may spread to the testicle itself, causing swelling and pain, which may be severe. Brucellosis can also affect the prostate gland and kidneys.
- Anemia. Anemia, in which you don't have enough healthy red blood cells, can cause pale skin, fatigue and shortness of breath.
- Skin rashes. Rashes and other skin problems are a rare complication of brucellosis.
- Miscarriage. Brucellosis may cause early pregnancy loss in some women.
- Hepatitis. Brucellosis can cause this serious liver disease, which, if not treated, can lead to liver scarring (cirrhosis) and ultimately to liver failure.
- Central nervous system infections. These include potentially life-threatening illnesses such as meningitis, an inflammation of the membranes surrounding the brain and spinal cord, and encephalitis, inflammation of the brain itself.
Treatments and drugs
By Mayo Clinic staff Treatment for brucellosis aims to relieve symptoms, prevent a relapse of the disease and avoid complications. You'll need to take medications for at least six weeks, and your symptoms may not go away completely for several months. The disease can also return and may become chronic.
Antibiotics
The standard treatment for brucellosis is a combination of two or three antibiotic medications, usually doxycycline in combination with streptomycin, rifampin or gentamicin. You'll take these drugs for six weeks or longer. If brucellosis has affected your central nervous system, you may need to take three antibiotics for as long as three months. Children and pregnant women can't take certain antibiotics, so their treatment may involve just one antibiotic or a different combination of drugs.
The standard treatment for brucellosis is a combination of two or three antibiotic medications, usually doxycycline in combination with streptomycin, rifampin or gentamicin. You'll take these drugs for six weeks or longer. If brucellosis has affected your central nervous system, you may need to take three antibiotics for as long as three months. Children and pregnant women can't take certain antibiotics, so their treatment may involve just one antibiotic or a different combination of drugs.
Nov 16, 2010
WIDAL TEST ( simple steps)
Widal test is a tube agglutination test employed in the serological diagnosis of enteric fever. The test is named after
Georges Fernand Isidore Widal, a French physician and bacteriologist, born March 9, 1862, Algeria; died January
14, 1929, Paris.
Principle: Patients’ suffering from enteric fever would possess antibodies in their sera which can react and
agglutinate serial doubling dilutions of killed, coloured Salmonella antigens in a tube agglutination test.
Requirements: Widal rack, round-bottomed Felix tubes, conical-bottomed Dreyer’s tubes, water bath, doubly
diluted patient serum in three-four rows, Killed coloured suspensions of S.typhi O antigen, S.typhi H antigen,
S.paratyphi AH antigen and optionally S.paratyphi BH antigen.
Preparation of antigens: Salmonella typhi 901 strain is used to prepare S.typhi O and S.typhi H antigens. O
antigens for S.paratyphi A and S.paratyphi B are not taken as they cross-react with S.typhi O antigen. H antigen
suspension is prepared by treating overnight broth culture or saline suspension of Salmonella with 0.1% formalin.
For preparing O antigen suspension, Salmonella are grown on phenol agar (1:800) to inhibit flagella. The growth is
then emulsified in small volume of saline, mixed with 20 times its volume of alcohol, heated at 40oC to 50oC for 30
minutes and centrifuged. The antigens are treated with chloroform (preservative) and appropriate dyes are added
for easy identification of antigens.
Procedure:
© Sridhar Rao P.N (www.microrao.com)
Patient serum is doubly diluted by mixing and transferring from 1:10 to 1:640 in three-four rows. First row usually
comprises of Felix tubes, where somatic S.typhi O antigen is added. For all the remaining rows, Dreyer’s tubes are
taken; where different flagellar H antigens are added. Each tube must contain 0.5ml of diluted serum. A test tube
with only saline is kept in each row as control. All the tubes (including control) in a row are mixed with 0.5ml of
antigen suspension. The first row is treated with S.typhi O antigen, the second row with S.typhi H antigen, the third
row with S.paratyphi AH antigen and the fourth row with S.paratyphi BH antigen. Since infections by S.paratyphi B
are rare, this antigen is usually omitted in the test. After all the tubes have been treated with specific antigen
suspensions, the widal rack is placed in a thermostatically controlled water bath maintained at 37oC for overnight
incubation. Another approach is to incubate the tubes at 50-55oC.
Reading the results: The control tubes must be examined first, where they should give no agglutination. The
agglutination of O antigen appears as a “matt” or “carpet” at the bottom. Agglutination of H antigens appears loose,
wooly or cottony. The highest dilution of serum that produces a positive agglutination is taken as titre. The titres for
all the antigens are noted.
Slide widal test:
A slide widal test is more popular among diagnostic laboratories as it gives rapid results.
Qualitative test: One drop each of undiluted patients’ serum samples for the four antigens are placed on the circled
card and one drop of each of the four Salmonella antigens are added separately and gently rotated for one minute.
Appearance of agglutination gives qualitative results. To know the titre for each of the antigens, the test is repeated
with dilutions of serum.
Quatitative test: 80 µl, 40 µl, 20 µl, 10 µl and 5 µl of patient’s serum each for the four antigens are placed on the
circled card. To each series of serum specimen, one drop of specific antigen is added to each, mixed and rotated
for one minute. Agglutination in each of these is noted. 80 µl corresponds to 1in 20 dilution, 40 µl to 1 in 40, 20 µl to
1 in 80, 10 µl to 1 in 160 and 5 µl corresponds to 1 in 320 titre.
Interpretation of widal test:
Timing of test is important, as antibodies begin to arise during end of first week. The titres increase during
second, third and fourth week after which it gradually declines. The test may be negative in early part of first
week.
Single test is usually of not much value. A rise in titre between two sera specimens is more meaningful than
a single test. If the first sample is taken late in the disease, a rise in titre may not be demonstrable. Instead,
there may be a fall in titre.
Baseline titre of the population must be known before attaching significance to the titres. The antibody
levels of individuals in a population of a given area give the baseline titre. A titre of 100 or more for O
antigen is considered significant and a titre in excess of 200 for H antigens is considered significant.
Patients already treated with antibiotics may not show any rise in titre, instead there may be fall in titre.
Patients treated with antibiotics in the early stages may not give positive results.
Patients who have received vaccines against Salmonella may give false positive reactions. This can be
differentiated from true infection by repeating the test after a week. True untreated infection results in rise in
titre whereas vaccinated individuals don’t demonstrate any rise in titre.
Those individuals, who had suffered from enteric fever in the past, sometimes develop anti-Salmonella
antibodies during an unrelated or closely related infection. This is termed anamnestic response and can be
differentiated from true infection by lack of any rise in titre on repetition after a week.
Antigen suspensions with fimbrial antigens may sometimes give false positive reactions due to sharing of
fimbrial antigens by some Enterobacteriaceae members. Antigen suspension must be devoid of fimbrial
antigens.
* Widal test is losing its relevance in Western and European nations but continues to be used in India.
Georges Fernand Isidore Widal, a French physician and bacteriologist, born March 9, 1862, Algeria; died January
14, 1929, Paris.
Principle: Patients’ suffering from enteric fever would possess antibodies in their sera which can react and
agglutinate serial doubling dilutions of killed, coloured Salmonella antigens in a tube agglutination test.
Requirements: Widal rack, round-bottomed Felix tubes, conical-bottomed Dreyer’s tubes, water bath, doubly
diluted patient serum in three-four rows, Killed coloured suspensions of S.typhi O antigen, S.typhi H antigen,
S.paratyphi AH antigen and optionally S.paratyphi BH antigen.
Preparation of antigens: Salmonella typhi 901 strain is used to prepare S.typhi O and S.typhi H antigens. O
antigens for S.paratyphi A and S.paratyphi B are not taken as they cross-react with S.typhi O antigen. H antigen
suspension is prepared by treating overnight broth culture or saline suspension of Salmonella with 0.1% formalin.
For preparing O antigen suspension, Salmonella are grown on phenol agar (1:800) to inhibit flagella. The growth is
then emulsified in small volume of saline, mixed with 20 times its volume of alcohol, heated at 40oC to 50oC for 30
minutes and centrifuged. The antigens are treated with chloroform (preservative) and appropriate dyes are added
for easy identification of antigens.
Procedure:
© Sridhar Rao P.N (www.microrao.com)
Patient serum is doubly diluted by mixing and transferring from 1:10 to 1:640 in three-four rows. First row usually
comprises of Felix tubes, where somatic S.typhi O antigen is added. For all the remaining rows, Dreyer’s tubes are
taken; where different flagellar H antigens are added. Each tube must contain 0.5ml of diluted serum. A test tube
with only saline is kept in each row as control. All the tubes (including control) in a row are mixed with 0.5ml of
antigen suspension. The first row is treated with S.typhi O antigen, the second row with S.typhi H antigen, the third
row with S.paratyphi AH antigen and the fourth row with S.paratyphi BH antigen. Since infections by S.paratyphi B
are rare, this antigen is usually omitted in the test. After all the tubes have been treated with specific antigen
suspensions, the widal rack is placed in a thermostatically controlled water bath maintained at 37oC for overnight
incubation. Another approach is to incubate the tubes at 50-55oC.
Reading the results: The control tubes must be examined first, where they should give no agglutination. The
agglutination of O antigen appears as a “matt” or “carpet” at the bottom. Agglutination of H antigens appears loose,
wooly or cottony. The highest dilution of serum that produces a positive agglutination is taken as titre. The titres for
all the antigens are noted.
Slide widal test:
A slide widal test is more popular among diagnostic laboratories as it gives rapid results.
Qualitative test: One drop each of undiluted patients’ serum samples for the four antigens are placed on the circled
card and one drop of each of the four Salmonella antigens are added separately and gently rotated for one minute.
Appearance of agglutination gives qualitative results. To know the titre for each of the antigens, the test is repeated
with dilutions of serum.
Quatitative test: 80 µl, 40 µl, 20 µl, 10 µl and 5 µl of patient’s serum each for the four antigens are placed on the
circled card. To each series of serum specimen, one drop of specific antigen is added to each, mixed and rotated
for one minute. Agglutination in each of these is noted. 80 µl corresponds to 1in 20 dilution, 40 µl to 1 in 40, 20 µl to
1 in 80, 10 µl to 1 in 160 and 5 µl corresponds to 1 in 320 titre.
Interpretation of widal test:
Timing of test is important, as antibodies begin to arise during end of first week. The titres increase during
second, third and fourth week after which it gradually declines. The test may be negative in early part of first
week.
Single test is usually of not much value. A rise in titre between two sera specimens is more meaningful than
a single test. If the first sample is taken late in the disease, a rise in titre may not be demonstrable. Instead,
there may be a fall in titre.
Baseline titre of the population must be known before attaching significance to the titres. The antibody
levels of individuals in a population of a given area give the baseline titre. A titre of 100 or more for O
antigen is considered significant and a titre in excess of 200 for H antigens is considered significant.
Patients already treated with antibiotics may not show any rise in titre, instead there may be fall in titre.
Patients treated with antibiotics in the early stages may not give positive results.
Patients who have received vaccines against Salmonella may give false positive reactions. This can be
differentiated from true infection by repeating the test after a week. True untreated infection results in rise in
titre whereas vaccinated individuals don’t demonstrate any rise in titre.
Those individuals, who had suffered from enteric fever in the past, sometimes develop anti-Salmonella
antibodies during an unrelated or closely related infection. This is termed anamnestic response and can be
differentiated from true infection by lack of any rise in titre on repetition after a week.
Antigen suspensions with fimbrial antigens may sometimes give false positive reactions due to sharing of
fimbrial antigens by some Enterobacteriaceae members. Antigen suspension must be devoid of fimbrial
antigens.
* Widal test is losing its relevance in Western and European nations but continues to be used in India.
Widal test
The Widal test is a presumptive serological test for enteric fever or undulant fever. In case of Salmonella infections, it is a demonstration of agglutinating antibodies against antigens O-somatic and H-flagellar in the blood. For brucellosis, only O-somatic antigen is used.
The Widal test is not a very specific test, since patients are often exposed to other bacteria (e.g. Salmonella enteritidis, Salmonella typhimurium and some types of E. coli) in this species that induce cross-reactivity; many people have antibodies against these enteric pathogens, which also react with the antigens in the Widal test, causing a false-positive result. Test results need to be interpreted carefully in the light of past history of enteric fever, typhoid vaccination, and the general level of antibodies in the populations in endemic areas of the world. Typhidot is the other test used to ascertain the diagnosis of typhoid fever. As with all serological tests, the rise in antibody levels needed to make the diagnosis takes 7-14 days, which limits. Other means of diagnosing Salmonella typhi (and paratyphi) include cultures of blood, urine and faeces. The organism also produces H2S from thiosulfate.
Often 2-mercaptoethanol is added. This agent more easily denatures the IgM class of antibodies, so if a decrease in the titer is seen after using this agent, it means that the contribution of IgM has been removed leaving the IgG component. This differentiation of antibody classes is important; as it allows for the distinction of a recent (IgM) from an old infection (IgG)
The Widal test is positive if TO antigen titer is more than 1:160 in an active infection, or if TH antigen titer is more than 1:160 in past infection or in immunized persons. A single Widal test is of little clinical relevance due to the number of cross reacting infections, including malaria. If no other tests (either bacteriologic culture or more specific serology) are available, a four fold increase in the titer (e.g., from 1:40 to 1:160) in the course of the infection, or a conversion from an IgM reaction to an IgG reaction of at least the same titer, would be consistent with a typhoid infection.
The Widal test is "a test involving agglutination of typhoid bacilli when they are mixed with serum containing typhoid antibodies from an individual having typhoid fever; which may be used to detect the presence of Salmonella typhi and S. paratyphi
Testing the Stool Sample
In general, the results of stool tests are usually reported back within 3 to 4 days, although it often takes longer for parasite testing to be completed.
Examining the Stool for Blood
Your doctor will sometimes check the stool for blood, which can be caused by certain kinds of infectious diarrhea, bleeding within the gastrointestinal tract, and other conditions. However, most of the time, blood streaking in the stool of an infant or toddler is from a slight rectal tear, called a fissure, which is caused by straining against a hard stool (this is fairly common in infants and kids with ongoing constipation).
Testing for blood in the stool is often performed with a quick test in the office that can provide the results immediately. First, stool is smeared on a card, then a few drops of a developing solution are placed on the card. An instant color change shows that blood is present in the stool. Sometimes, stool is sent to a laboratory to test for blood, and the result will be reported within hours.
Culturing the Stool
Stool can be cultured for disease-causing bacteria. A stool sample is placed in an incubator for at least 48 to 72 hours and any disease-causing bacteria are identified and isolated. Remember that not all bacteria in the stool cause problems; in fact, about half of stool is bacteria, most of which live there normally and are necessary for digestion. In a stool culture, lab technicians are most concerned with identifying bacteria that cause disease.
For a stool culture, the lab will need a fresh or refrigerated sample of stool. The best samples are of loose, fresh stool; well-formed stool is rarely positive for disease-causing bacteria. Sometimes, more than one stool will be collected for a culture.
Swabs from a child's rectum also can be tested for viruses. Although this is not done routinely, it can sometimes give clues about certain illnesses, especially in newborns or very ill children. Viral cultures can take a week or longer to grow, depending on the virus.
Testing the Stool for Ova and Parasites
Stool may be tested for the presence of parasites and ova (the egg stage of a parasite) if a child has prolonged diarrhea or other intestinal symptoms. Sometimes, the doctor will collect two or more samples of stool to successfully identify parasites. If parasites — or their eggs — are seen when a smear of stool is examined under the microscope, the child will be treated for a parasitic infestation. The doctor may give you special collection containers that contain chemical preservatives for parasites.
Collecting a Stool Specimen
Unlike most other lab tests, stool is sometimes collected by the child's family at home, not by a health care professional. Here are some tips for collecting a stool specimen:
- Collecting stool can be messy, so be sure to wear latex gloves and wash your hands and your child's hands well afterward.
- Many kids with diarrhea, especially young children, can't always let a parent know in advance when a bowel movement is coming. Sometimes a hat-shaped plastic lid is used to collect the stool specimen. This catching device can be quickly placed over the toilet bowl or your child's rear end to collect the specimen. Using a catching device can prevent contamination of the stool by water and dirt. If urine contaminates the stool sample, it will be necessary to take another sample. Also, if you're unable to catch the stool sample before it touches the inside of the toilet, the sample will need to be repeated. Fishing a bowel movement out of the toilet does not provide a clean specimen for the laboratory to analyze.
- Another way to collect a stool sample is to loosely place plastic wrap across the rim of the toilet, under the seat. Then place the stool sample in a clean, sealable container before taking to the laboratory. Plastic wrap can also be used to line the diaper of an infant or toddler who is not yet using the toilet.
The stool should be collected into clean, dry plastic jars with screw-cap lids. You can get these from your doctor or through hospital laboratories or pharmacies, although any clean, sealable container could do the job. For best results, the stool should then be brought to the laboratory immediately.
If it's impossible to get the sample to the laboratory right away, the stool should be refrigerated, then taken to the laboratory to be cultured as soon as possible after collection. When the sample arrives at the lab, it is either examined and cultured immediately or placed in a special liquid medium that attempts to preserve potential bacteria or parasites.
The doctor or the hospital laboratory will usually provide written instructions on how to successfully collect a stool sample; if written instructions are not provided, take notes on how to collect the sample and what to do once you've collected it.
If you have any questions about how to collect the specimen, be sure to ask. The doctor or the lab will also let you know if a fresh stool sample is needed for a particular test, and if it will need to be brought to the laboratory right away.
Most of the time, disease-causing bacteria or parasites can be identified from a single stool specimen. Sometimes, however, up to three samples from different bowel movements must be taken. The doctor will let you know if this is the case.
Stool Tests
Stool (or feces) is usually thought of as nothing but waste — something to quickly flush away. But bowel movements can provide doctors with valuable information as to what's wrong when a child has a problem in the stomach, intestines, or another part of the gastrointestinal system.
A doctor may order a stool collection to test for a variety of possible conditions, including:
Stool samples are also sometimes analyzed for what they contain; for instance, examining the fat content. Normally, fat is completely absorbed from the intestine, and the stool contains virtually no fat. In certain types of digestive disorders, however, fat is incompletely absorbed and remains in the stool.
A doctor may order a stool collection to test for a variety of possible conditions, including:
- allergy or inflammation in the body, such as part of the evaluation of milk protein allergy in infants
- infection, as caused by some types of bacteria, viruses, or parasites that invade the gastrointestinal system
- digestive problems, such as the malabsorption of certain sugars, fats, or nutrients
- bleeding inside of the gastrointestinal tract
Stool samples are also sometimes analyzed for what they contain; for instance, examining the fat content. Normally, fat is completely absorbed from the intestine, and the stool contains virtually no fat. In certain types of digestive disorders, however, fat is incompletely absorbed and remains in the stool.
Nov 15, 2010
MICROSCOPIC URINALYSIS
MICROSCOPIC URINALYSIS:
Urine is centrifuged in a test tube forming a cohesive button at the bottom of the tube. The sediment is resuspended in the remaining supernate and a drop of resuspended sediment is poured onto a glass slide and coverslipped. The sediment is first examined under the microscope at both low and high power.
Low power examination is used to determine the numbers of casts seen are usually reported as number of each type found per low power field (LPF). Example: 5-10 hyaline casts/L casts/LPF.
High power examination is used to identify crystals, cells, and bacteria. The various types of cells are usually described as the number of each type found per average high power field (HPF). Example: 1-5 WBC/HPF.
MICROSCOPIC URINALYSIS MAY INCLUDE:
- Red Blood Cells: Hematuria is the presence of abnormal numbers of red cells in urine due to: glomerular damage, tumors which erode the urinary tract anywhere along its length, kidney trauma, urinary tract stones, renal infarcts, acute tubular necrosis, upper and lower uri urinary tract infections, nephrotoxins, and physical stress.Red cells may also contaminate the urine from the vagina in menstruating women or from trauma produced by bladder catherization. Theoretically, no red cells should be found, but some find their way into the urine even in very healthy individuals. However, if one or more red cells can be found in every high power field, and if contamination can be ruled out, the specimen is probably abnormal.RBC's may appear normally shaped, swollen by dilute urine (in fact, only cell ghosts and free hemoglobin may remain), or crenated by concentrated urine. Both swollen, partly hemolyzed RBC's and crenated RBC's are sometimes difficult to distinguish from WBC's in the urine. In addition, red cell ghosts may simulate yeast. The presence of dysmorphic RBC's in urine suggests a glomerular disease such as a glomerulonephritis. Dysmorphic RBC's have odd shapes as a consequence of being distorted via passage through the abnormal glomerular structure.
- White blood cells: Pyuria refers to the presence of abnormal numbers of leukocytes that may appear with infection in either the upper or lower urinary tract or with acute glomerulonephritis. Usually, the WBC's are granulocytes. White cells from the vagina, especially in the presence of vaginal and cervical infections, or the external urethral meatus in men and women may contaminate the urine. If two or more leukocytes per each high power field appear in non-contaminated urine, the specimen is probably abnormal.
- Epithelial cells: Renal tubular epithelial cells, usually larger than granulocytes, contain a large round or oval nucleus and normally slough into the urine in small numbers.However, with nephrotic syndrome and in conditions leading to tubular degeneration, the number sloughed is increased. When lipiduria occurs, these cells contain endogenous fats. When filled with numerous fat droplets, such cells are called oval fat bodies. Oval fat bodies exhibit a "Maltese cross" configuration by polarized light microscopy.Transitional epithelial cells from the renal pelvis, ureter, or bladder have more regular cell borders, larger nuclei, and smaller overall size than squamous epithelium.Renal tubular epithelial cells are smaller and rounder than transitional epithelium, and their nucleus occupies more of the total cell volume.Squamous epithelial cells from the skin surface or from the outer urethra can appear in urine. Their significance is that they represent possible contamination of the specimen with skin flora.
- Casts: Urinary casts are formed only in the distal convoluted tubule (DCT) or the collecting duct (distal nephron). The proximal convoluted tubule (PCT) and loop of Henle are not locations for cast formation.Hyaline casts are composed primarily of a mucoprotein (Tamm-Horsfall protein) secreted by tubule cells. Even with glomerular injury causing increased glomerular permeability to plasma proteins with resulting proteinuria, most matrix or "glue" that cements urinary casts together is Tamm-Horsfall mucoprotein, although albumin and some globulins are also incorporated.The factors which favor protein cast formation are low flow rate, high salt concentration, and low pH, all of which favor protein denaturation and precipitation, particularly that of the Tamm-Horsfall protein. Protein casts with long, thin tails formed at the junction of Henle's loop and the distal convoluted tubule are called cylindroids. Hyaline casts can be seen even in healthy patients.Red blood cells may stick together and form red blood cell casts. Such casts are indicative of glomerulonephritis, with leakage of RBC's from glomeruli, or severe tubular damage.White blood cell casts are most typical for acute pyelonephritis, but they may also be present with glomerulonephritis. Their presence indicates inflammation of the kidney, because such casts will not form except in the kidney.When cellular casts remain in the nephron for some time before they are flushed into the bladder urine, the cells may degenerate to become a coarsely granular cast, later a finely granular cast, and ultimately, a waxy cast. Granular and waxy casts are be believed to derive from renal tubular cell casts.Broad casts are believed to emanate from damaged and dilated tubules and are therefore seen in end-stage chronic renal disease.The so-called telescoped urinary sediment is one in which red cells, white cells, oval fat bodies, and all types of casts are found in more or less equal profusion. The conditions which may lead to a telescoped sediment are: 1) lupus nephritis 2) malignant hypertension 3) diabetic glomerulosclerosis, and 4) rapidly progressive glomerulonephritis. In end-stage kidney disease of any cause, the urinary sediment often becomes very scant because few remaining nephrons produce dilute urine.
- Bacteria : Bacteria are common in urine specimens because of the abundant normal microbial flora of the vagina or external urethral meatus and because of their ability to rapidly multiply in urine standing at room temperature. Therefore, microbial organisms found in all but the most scrupulously collected urines should be interpreted in view of clinical symptoms.Diagnosis of bacteriuria in a case of suspected urinary tract infection requires culture. A colony count may also be done to see if significant numbers of bacteria are present. Generally, more than 100,000/ml of one organism reflects significant bacteriuria. Multiple organisms reflect contamination. However, the presence of any organism in catheterized or suprapubic tap specimens should be considered significant.
- Yeast: Yeast cells may be contaminants or represent a true yeast infection. They are often difficult to distinguish from red cells and amorphous crystals but are distinguished by their tendency to bud. Most often they are Candida, which may colonize bladder, urethra, or vagina.
- Crystals: Common crystals seen even in healthy patients include calcium oxalate, triple phosphate crystals and amorphous phosphates.Very uncommon crystals include: cystine crystals in urine of neonates with congenital cystinuria or severe liver disease, tyrosine crystals with congenital tyrosinosis or marked liver impairment, or leucine crystals in patients with severe liver disease or with maple syrup urine disease. Oxalate crystals in urine Triple phosphate crystals in urine Cystine crystals in urine.
Urinalysis
Also known as: Urine test; Urine analysis; UA
1-MACROSCOPIC URINALYSIS:
- Color : Normal, fresh urine is pale to dark yellow or amber in color A red or red-brown (abnormal) color could be from a food dye, eating fresh beets, a drug, or the presence of either hemoglobin or myoglobin. If the sample contained many red blood cells ( Haematuria ), it would be cloudy as well as red.
- Volume : 750 to 2000 ml/24hr.
- Clarity : Turbidity or cloudiness may be caused by excessive cellular material or protein in the urine or may develop from crystallization or precipitation of salts upon standing at room temperature or in the refrigerator. Clearing of the specimen after addition of a small amount of acid indicates that precipitation of salts is the probable cause of turbidity.
- pH : The glomerular filtrate of blood plasma is usually acidified by renal tubules and collecting ducts from a pH of 7.4 to about 6 in the final urine. However, depending on the acid-base status, urinary pH may range from as low as 4.5 to as high as 8.0. The change to the acid side of 7.4 is accomplished in the distal convoluted tubule and the collecting duct.
- Specific gravity : Any specific gravity > 1.022 measured in a randomly collected specimen denotes adequate renal concentration so long as there are no abnormal solutes in the urine. (which is directly proportional to urine osmolality which measures solute concentration) measures urine density, or the ability of the kidney to concentrate or dilute the urine over that of plasm.
- Protein :Screening for protein is done on whole urine, but semi-quantitative tests for urine protein should be performed on the supernatant of centrifuged urine since the cells suspended in normal urine can produce a falsely high estimation of protein.Normally, only small plasma proteins filtered at the glomerulus are reabsorbed by the renal tubule. However, a small amount of filtered plasma proteins and protein secreted by the nephron (Tamm-Horsfall protein) can be found in normal urine. Normal total protein excretion does not usually exceed 150 mg/24 hours or 10 mg/100 ml in any single specimen. More than 150 mg/day is defined as proteinuria. Proteinuria > 3.5 gm/24 hours is severe and known as nephrotic syndrome.Dipsticks detect protein by production of color with an indicator dye, Bromphenol blue, which is most sensitive to albumin but detects globulins and Bence-Jones protein poorly.
- Glucose : Less than 0.1% of glucose normally filtered by the glomerulus appears in urine (< 130 mg/24 hr). Glycosuria (excess sugar in urine) generally means diabetes mellitus. Dipsticks employing the glucose oxidase reaction for screening are specific for glucos glucose but can miss other reducing sugars such as galactose and fructose. For this reason, most newborn and infant urines are routinely screened for reducing sugars by methods other than glucose oxidase (such as the Clinitest, a modified Benedict's copper reduction test).
- Ketones :Ketones (acetone, aceotacetic acid, beta-hydroxybutyric acid) resulting from either diabetic ketosis or some other form of calorie deprivation (starvation), are easily detected using either dipsticks or test tablets containing sodium nitroprusside.
- Nitrite : A positive nitrite test indicates that bacteria may be present in significant numbers in urine.Gram negative rods such as E. coli are more likely to give a positive test.
- Leukocyte esterase : A positive leukocyte esterase test results from the presence of white blood cells either as whole cells or as lysed cells. Pyuria can be detected even if the urine sample contains damaged or lysed WBC's.A negative leukocyte esterase test means that an infection is unlikely and that, without additional evidence of urinary tract infection, microscopic exam and/or urine culture need not be done to rule out significant bacteriuria.
Nov 6, 2010
Venipuncture (Blood drawing)
In medicine, venepuncture,venopuncture or venipuncture is the process of obtaining intravenous access for the purpose of intravenous therapy or obtaining a sample of venousblood. This procedure is performed by medical laboratory scientists , medical practitioners, some EMTs, paramedics, phlebotomists and other nursing staff. Venepuncture is one of the most routinely performed invasive procedures and is carried out for two reasons, to obtain blood for diagnostic purposes or to monitor levels of blood components (Lavery & Ingram 2005). Blood analysis is one of the most important diagnostic tools available to clinicians within healthcare. Its data is relied upon in the clinical setting for interpretation of a myriad of clinical signs and symptoms and developing skills in venepuncture can facilitate holistic and timely treatment.
Blood is most commonly obtained from the median cubital vein, on the anterior forearm (the side within the fold of the elbow). This vein lies close to the surface of the skin, and there is not a large nerve supply.
Minute quantities of blood may be taken by fingersticks sampling and collected from infants by means of a heel stick or from scalp veins with a winged infusion needle.
Phlebotomy (incision into a vein) is also the treatment of certain diseases such as hemochromatosis and primary and secondary polycythemia
Blood Glucose
blood glucose test measures the amount of a type of sugar, called glucose, in your blood. Glucose comes from carbohydrate foods. It is the main source of energy used by the body. Insulin is a hormone that helps your body's cells use the glucose. Insulin is productiveness and released into the blood when the amount of glucose in the blood rises.
Normally, your blood glucose levels increase slightly after you eat. This increases to release insulin so that your blood glucose levels do not get too high. Blood glucose levels that remain high over time can damage your eyes, kidneys, nerves, and blood vessels.
Several different types of blood glucose tests are used.
Fasting blood sugar (FBS) measures blood glucose after you have not eaten for at least 8 hours. It is often the first test done to check for prediabetes and diabetes.
2-hour postprandial blood sugar measures blood glucose exactly 2 hours after you start eating a meal.
Random blood sugar (RBS) measures blood glucose regardless of when you last ate. Several random measurements may be taken throughout the day. Random testing is useful because glucose levels in healthy people do not vary widely throughout the day. Blood glucose levels thatvary widely may mean a problem. This test is also called a casual bloodglucose test.
Oral glucose tolerance test is used to diagnose prediabetes and diabetes. Anoralglucosetolerance test is a series of blood glucose measurements taken after you drink a sweetliquidthat contains glucose. This test is commonly used to diagnose diabetes thatoccursduringpregnancy (gestational diabetes). For more information, see the medical test Oral Glucose Tolerance Test. This test is not commonly used to diagnose diabetes in a person whoisnotpregnant.
Why It Is Done
Blood glucose tests are done to:
Check for diabetes.
Monitor treatment of diabetes.
Check for diabetes that occurs during pregnancy (gestational diabetes).
Determine if an abnormally low blood sugar level (hypoglycemia) is present. A testtomeasureblood levels of insulin and a protein called C-peptide may be done along with a bloodglucosetest to determine the cause of hypoglycemia. For more information, see themedicaltestC-Peptide.
Normally, your blood glucose levels increase slightly after you eat. This increases to release insulin so that your blood glucose levels do not get too high. Blood glucose levels that remain high over time can damage your eyes, kidneys, nerves, and blood vessels.
Several different types of blood glucose tests are used.
Fasting blood sugar (FBS) measures blood glucose after you have not eaten for at least 8 hours. It is often the first test done to check for prediabetes and diabetes.
2-hour postprandial blood sugar measures blood glucose exactly 2 hours after you start eating a meal.
Random blood sugar (RBS) measures blood glucose regardless of when you last ate. Several random measurements may be taken throughout the day. Random testing is useful because glucose levels in healthy people do not vary widely throughout the day. Blood glucose levels thatvary widely may mean a problem. This test is also called a casual bloodglucose test.
Oral glucose tolerance test is used to diagnose prediabetes and diabetes. Anoralglucosetolerance test is a series of blood glucose measurements taken after you drink a sweetliquidthat contains glucose. This test is commonly used to diagnose diabetes thatoccursduringpregnancy (gestational diabetes). For more information, see the medical test Oral Glucose Tolerance Test. This test is not commonly used to diagnose diabetes in a person whoisnotpregnant.
Why It Is Done
Blood glucose tests are done to:
Check for diabetes.
Monitor treatment of diabetes.
Check for diabetes that occurs during pregnancy (gestational diabetes).
Determine if an abnormally low blood sugar level (hypoglycemia) is present. A testtomeasureblood levels of insulin and a protein called C-peptide may be done along with a bloodglucosetest to determine the cause of hypoglycemia. For more information, see themedicaltestC-Peptide.
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