Specimen amniotic fluid

Bilirubin is often present in the liquor amnii when the fetus is affected by hemolytic disease of the newborn (B5). Walker (Wl) examined fresh specimens of amniotic fluid before the 35th week and found that the presence of bilirubin correctly indicated the disease in 94.5 Jo of his afflicted cases. 

NBD-PC Fluorescence Polarization Method The NBD-PC method, also called FPol, is described in detail on the Evolve site that accompanies this book. The specimen is amniotic fluid that has been centrifuged at 400 Xg for 2 minutes. Results are expressed using artificial units of mil-lipolarization (P x 1000, mP). The analytical measurement range is 150 to 350 mP. No calibrators are used, but use of a Triton XlOO control assures that the temperature is correct and that the dye is not degraded. Comparison of the TDx FLM II and the NBD-PC assay reveals, as expected, a strong nonlinear, inverse correlation ... 

For multifetal pregnancies, separate specimens should be analyzed for each fetus. Infrequently, more than one fetus shares an amniotic fluid cavity. In such a case, a mature result is less predictive of maturity, because it represents a mixture of pulmonary surfactant from multiple fetuses. In the case of twins, the smaller is more likely to develop RDS than the larger. ... 

Dombroski RA, Mackenna J, Brame RG. Comparison of amniotic fluid lung maturity profiles in paired vaginal and amniocentesis specimens. Am J Obstet Gynecol 1981 140 461-4. 

Sterol-A -isomerase deficiency, known as Conradi-HUnermann syndrome (CDPX2), is an X-linked dominant disorder. Clinical manifestations of this disorder include skeletal abnormalities, chondrodysplasia punctata, craniofacial anomalies, cataracts, and skin abnormalities. The 7-dehydrocholesterol reductase deficiency, known as Smith-Lemli-Opitz syndrome (SLO) is an autosomal recessive disorder occurring in about 1 in 20,000 births. Clinical manifestations of affected individuals include craniofacial abnormalities, microcephaly, congenital heart disease, malformation of the limbs, psychomotor retardation, cerebral maldevelopment, and urogenital anomalies. Measurement of 7-dehydrocholesterol in amniotic fluid during second trimester or in neonatal blood specimen has been useful in the identification of the disorder. The sterol-A " -reductase deficiency causes a developmental phenotype similar to SLO syndrome and is associated with accumulation of desmosterol. The inability of de novo fetal synthesis of cholesterol combined with its inadequate transport from the mother to the fetus appears... 

Extraction of specimens with a suitable organic solvent and concentration of the extract prior to chromatography has been used for urine, plasma, blood, breast milk, amniotic fluid and saliva. 

IR spectroscopic analysis offers a number of practical advantages that make it a natural fit for high-volume applications of the type epitomized by serum and urine analysis, as well as for labor-intensive tests such as the amniotic fluid lecithin/sphingomyelin ratio. No reagents are required, there is generally no need to dilute very concentrated specimens (as may be required for certain other analytical methods), several analyses are available... 

Blood and body fluids include bulk laboratory specimens of blood tissue, sanen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, and amniotic fluid. Precautions do not apply to feces, nasal secretions, sputum, sweat, tears, urine, or vomit unless they contain visible blood. Handle free-flowing materials or items saturated to the point of dripping liquids containing visible blood or blood components. Pathological waste includes all discarded waste from renal dialysis contaminated with peritoneal fluid or blood visible to the human eye. Consider solid renal dialysis waste as medical waste if saturated and demonstrate the potential to drip/splash blood or other regulated body fluids. Waste sharps include any used or unused discarded article that may cause punctures or cuts. 

Urine samples for carnitine and acylcarnitine analysis should be frozen and shipped on dry ice (note however that urine is not recommended as a specimen for diagnosis, especially for defects of fatty acid oxidation). For convenience where distance from the testing laboratory is an issue, urine for these tests can also be spotted onto cotton fiber filter paper, allowed to dry and mailed in an envelope. Amniotic fluid should be frozen and shipped on dry ice. 

Blood and body fluids include bulk laboratory specimens of blood tissue, semen, vaginal secretions, cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, and amniotic fluid. Precautions do not apply to feces, nasal secretions, sputum, sweat, tears, urine, or vomit unless... 

Many errors can occur during the collection, processing, and transport of biological specimens. Minimizing these errors win result in more reliable information for use by healthcare professionals. Examples of biological specimens that are analyzed in clinical laboratories include whole blood serum plasma urine feces saliva spinal, synovial, amniotic, pleural, pericardial, and ascitic fluids and various types of solid tissue. The National Committee for CMnical Laboratory Standards (NCCLS) has published several procedures for collecting many of these specimens under standardized conditio ns.In addition, the NCCLS has published documents related to sample collection and analysis for specialized tests, such as sweat chloride (see also Chapter 27). 

Enzyme activities may also be measured in urine, cerebrospinal fluid, bone marrow cells or fluid, amniotic cells or fluid, red blood cells, leukocytes, and tissue cells. Cytochemical localization is possible in leukocytes and biopsy specimens (e.g., from liver and muscle). Under ideal conditions, both the concentration of the enzyme and its activity would be measured. Radioimmunoassay (RIA) and its alternative modes such as fluorescence immunoassay (FIA), fluorescence polarization immunoassay (FPIA), and chemiluminescence immunoassay (CLIA) (discussed later), can be used to measure enzyme concentration as well as other clinically important parameters. 

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