WHAT'S IN THE SAMPLE?; TO PROFESSIONALS, A VIAL OF BLOOD OR URINE CAN HOLD THE SECRET TO MEDIAL MYSTERIES

Blood, the old saying goes, will tell. And technological and medical advances make blood, and other body fluids, tell a lot.

Depending on what particular tests are run, results can reveal everything from what the subject had for breakfast to what infections he's been exposed to and whether he was at the scene of a crime.

Experts can perform more than 200 assays -- analyses for particular chemical substances, medical conditions, enzyme reactions or other items -- on blood samples alone, said Tony Williams, lab director at Southeast Missouri Hospital.

Blood and urine can tell experts "almost" everything about an individual, Williams said.

"I don't know if I could tell what color your hair is" from a blood sample, he said. "But as far as far as diagnoses and tests, if you want to pay enough money for genetics testing or whatever, there's not many things that would be excluded, actually. There's not one thing that just springs to mind."

Pre-employment drug screening has probably "increased by 50 percent" in the last two or three years, Williams said. Other tests identify cancer antigens, blood volume, sexually transmitted diseases, the health of the immune system, etc.

DNA testing allows medical experts to determine whether particular viruses or bacteria are present by identifying specific genetic patterns belonging to those organisms.

At St. Francis Medical Center, DNA testing is used to determine whether patients have the sexually transmitted diseases chlamydia or gonorrhea. The Abbott LCX Probe system searches urine samples for the DNA patterns particular to those organisms, explained Dr. Don Miles, a clinical microbiologist at the hospital.

The new technology makes results quicker and more accurate, Miles said. Results can be ready in about five hours from the urine sample, as opposed to two to four days from a bacterial culture.

"Theoretically, if you had at least one organism, you could identify it with this system," he said.

"The significance of that, particularly with chlamydia, is there may be as many as 70 percent of people who won't know they're infected because they have no symptoms until they start developing pelvic inflammation or infertility," Miles said.

The LCX Probe only has FDA approval for chlamydia and gonorrhea testing at this time, he said, but more applications will become available in the next few years.

"The next one on the market will be direct TB testing," Miles said.

Using the probe, doctors will be able to test sputum samples directly for the presence of tuberculosis.

"The culture system we use now could take up to eight days," he said.

Quicker diagnoses mean doctors can begin to treat and contain the spread of the infection more quickly, he said.

Jim Schuette, service director of the laboratory at St. Francis Medical Center, said improved technology means experts can work with much smaller quantities, which means quicker results.

"We've gotten down to measuring in milligrams and micrograms," Schuette said.

Continued medical research also means that new components are being identified: the more experts learn, the more they can test for.

"Every year there's something new coming out that we didn't know about last year, some new component of the bloodstream or the urine that we didn't know about," Schuette said.

Most recently, he said, troponin has become the "new hot diagnostic marker" for acute myocardial infarctions, or heart attacks.

"There are things like that that continually come up to researchers," he said.

Another factor in improved testing is increased automation in the lab. Samples are no longer processed by hand by lab technicians. Instead, they're loaded in batches into computerized units that can run several tests at once on an individual sample.

"It's not unusual on a particular sample to test for 20 or 30 different things," Schuette said.

COMMONLY ORDERED LAB TESTS

Complete Blood Count (CBC) -- Measures white count, red count and blood volume

Culture -- Used to identify bacterial infection

Hemoglobin and Hematorcrit (H&H) -- Used to measure blood volume, check for anemia or blood loss

Lipoprotein Profile -- Screen for cholesterol both good and bad

Electrolytes -- Sodium, potassium and carbon dioxide level

BUN and Creatinine -- Used to monitor kidney function

Glucose -- Blood sugar level

Prostatic Specific Antigen (PSA) -- Screen for prostate cancer

Protime (PT) -- Used to monitor anticoagulant drugs

PTT (Partial Thromboplastin Time) -- Used to monitor blood-clotting factors

RPR -- Screen for syphilis

TSH -- Thyroid stimulating hormone

T3/T4 -- Monitor thyroid function

Urinalysis -- Screen used for urinary infections and/or general health

Rubella -- Used to determine immune status for measles

Chlamydia/GC Probe -- Diagnosis of sexually transmitted disease

BHGG -- Pregnancy test