Non-PCR-dependent detection of the factor V Leiden mutation from genomic DNA using a homogeneous invader microtiter plate assay.

Background: The goal of this study was to compare the Invader technology for the direct detection of the Factor V Leiden mutation from genomic DNA with a conventional polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

Methods And Results: In the Invader assay, a specific upstream "invading" oligonucleotide and a partially overlapping downstream probe together form a specific structure when bound to complementary DNA template. This structure is recognized and cut at a specific site by the Cleavase enzyme, resulting in release of the 59 flap of the probe oligonucleotide.

Decreased maternal serum hCG levels with increasing gravidity and parity.

Objective: To investigate the preliminary observation that primigravid women have higher hCG multiples of the median (MoM) than multigravid women.

Methods: An analysis of the effect of gravidity and parity on maternal serum alpha-fetoprotein (MSAFP) and hCG was performed using data from 20,009 consecutive singleton pregnancies of 15-20 weeks' gestation in a maternal serum screening program.

Results: The human chorionic gonadotropin MoM for primigravid women was 0.

Effectiveness of combining maternal serum alpha-fetoprotein and hCG in a second-trimester screening program for Down syndrome.

Objective: To evaluate the efficacy of combining hCG and alpha-fetoprotein (AFP) with maternal age in a two-analyte maternal serum screening program for Down syndrome.

Methods: A prospective study involved the screening of 12,170 maternal sera from patients at 14-25 weeks of gestation. The risk for Down syndrome at term was calculated from maternal serum hCG and AFP, and maternal age.

Combined serum amylase and lipase determinations for diagnosis of suspected acute pancreatitis.

Serum amylase and lipase measurements are often used to diagnose acute pancreatitis. This study addresses the question of whether it is advantageous to order serum amylase and lipase tests simultaneously. We evaluated performance of the two tests separately and in combination through a retrospective study of patients for whom both amylase and lipase determinations were ordered.

Relevance of common tests of cerebrospinal fluid in screening for bacterial meningitis.

This study tests the hypothesis that if cerebrospinal fluid (CSF) has a nucleated blood cell count (NucBC) of less than 6/mm3, CSF tests other than bacterial culture need not be performed to exclude the diagnosis of bacterial meningitis in patients not receiving antimicrobial agents. The results of tests performed on the first specimen of CSF obtained for a given hospital visit from children younger than 3 years of age, exclusive of newborn infants admitted to the hospital on their date of birth, were analyzed. Of 3356 CSF specimens evaluated, 122 were from patients with bacterial meningitis; 460 specimens were analyzed separately because the erythrocyte count was greater than 1000/mm3.

Electron microscopy of human factor V and factor VIII: correlation of morphology with domain structure and localization of factor V activation fragments.

Clotting factor V and factor VIII are each represented by the domain structure A1-A2-B-A3-C1-C2 and share 40% sequence homology in the A and C domains. Rotary-shadowed samples of human factor V and factor VIII were examined in the electron microscope. Single-chain factor V molecules exhibited a globular "head" domain 12-14 nm in diameter.

Megakaryocyte and hepatocyte origins of human fibrinogen biosynthesis exhibit hepatocyte-specific expression of gamma chain-variant polypeptides.

The gamma chain of human fibrinogen is heterogeneous in length at the C-terminus due to differential RNA processing of the gamma chain-gene primary transcript. We have produced two specific monoclonal antibodies (MoAbs) against the gamma-chain epitopes generated by this alternative processing event: anti-gamma 57.5(408-416) (L2B), which reacts with gamma 57.

A critical survey of fresh-frozen plasma use.

The use of 534 units of fresh-frozen plasma (FFP) during 160 transfusion episodes in 135 consecutive patients was reviewed. Only 27 percent of transfusions were indicated by a need for replacement of labile coagulation factors. Other uses included volume repletion (31%), intraoperative bleeding or massive transfusion without coagulopathy (19%), and miscellaneous indications unrelated to labile coagulation factors (23%).

Simultaneous determination of cerebrospinal fluid oligoclonal bands and the "gamma-protein index" by agarose electrophoresis and densitometry.

Oligoclonal bands were identified in electropherograms of cerebrospinal fluid, and the "gamma-protein index" was concurrently calculated from the same strip. For the index, an upper limit of normal of 0.66 was established.

Conjugated bilirubin: a better indicator of impaired hepatobiliary excretion than direct bilirubin.

A prototype KODAK EKTACHEM Clinical Chemistry Slide (BuBc) provided a measurement of serum conjugated bilirubin which was at least as sensitive to developing conjugated hyperbilirubinemia as values provided by a direct (diazo) bilirubin assay. Under conditions where the impairment of hepatobiliary excretion was relieved in patients being treated for various hepatobiliary diseases, conjugated bilirubin was cleared from serum more rapidly than alkaline phosphatase, the delta bilirubin fraction, and bilirubin measured by the direct and total bilirubin assays. It is concluded that the conjugated bilirubin measurement provided by the BuBc Slide appears to be an earlier indicator of relief from hepatobiliary cholestasis, or conversely of residual impairment, than direct bilirubin, total bilirubin, or alkaline phosphatase.

Glutamate dehydrogenase in Reye's syndrome. Evidence for the presence of an altered enzyme in serum with increased susceptibility to inhibition by GTP.

The glutamate dehydrogenase activity found in the serum of patients with Reye's syndrome is shown to be inhibited about 1000-fold more potently by GTP than is the normal human enzyme. 1 mM ADP, which with the normal enzyme effectively reverses GTP inhibition, has no effect in the GTP inhibition of the Reye's syndrome serum activity.

Masking by enzyme inhibitor of raised serum glutamate dehydrogenase activity in Reye's syndrome.

Serum glutamate dehydrogenase (GDH) activity was greatly raised (up to 830 times the upper limit of normal) in 16 patients with Reye's syndrome. The serum activity was masked by an inhibitor, and the rises were observed only after dialysis or sample dilution. Serum GDH values from 38 paediatric patients, including 10 with hyperammonaemia due to other causes, showed no such rise after dialysis.

Do preoperative laboratory tests predict blood transfusion needs in cardiac operations?

We retrospectively compared preoperative prothrombin (PT), partial thromboplastin (PTT), dilute whole blood clot lysis and bleeding times, fibrinogen level, and platelet count with subsequent blood component administration in 92 patients who had undergone cardiac operations with cardiopulmonary bypass (CPB). Abnormal results for one or more tests were found in 34% of 71 adults and 81% of 21 children and teenagers. The patients with abnormal test(s) received no more whole blood and packed red cell units, platelets, or plasma than those with normal tests in either age group.

Spurious elevation of the electronically determined mean corpuscular volume and hematocrit caused by hyperglycemia.

Following normalization of blood glucose levels, a marked change in the MCV and in the calculated hematocrit was observed in five patients with transient severe hyperglycemia. The addition of varied concentrations of glucose to blood samples from healthy volunteers and from patients with microcytic, macrocytic, and normocytic anemia produced a similar and proportionate increase in the MCV. Increases in urea concentration to clinically relevant levels had no effect.

Isoelectric focusing of hemoglobins on thin-layer agarose.

Isoelectric focusing on thin layers of agarose was used to separate several human hemoglobin variants in narrow pH range (pH 6-9). Problems with gel flooding and distortions due to electroendosmotic flow were solved by altering the casting and processing of the gel, by modifying the focusing apparatus, and by utilizing commercial agarose that had been chemically modified to reduce electroendomosis. Hemoglobins C, O-ARAB, A2, and E were distinguished from one another, as were hemoglobins S, D-LOS ANGELES, G-PHILADELPHIA, F.

alpha-Fetoprotein in the routine clinical laboratory: evaluation of a simple radioimmunoassay and review of current concepts in its clinical application.

We have assessed the clinical utility of a radioimmunoassay for alpha-fetoprotein (AFP). The method, which relies on ammonium sulfate precipitation for the separation of "bound" and "free" radiolabeled antigen, can be completed in one working day. The assay is specific for AFP, has a sensitivity of < 10 ng/ml, and has intra- and inter-assay precision of 5--8% and 9--11%, respectively.

Fetal-maternal bleeding associated with genetic amniocentesis.

Maternal serum alpha-fetoprotein (AFP) elevation following midtrimester genetic amniocentesis (post-AFP) was studied as an indicator of fetal-to-maternal bleeding (FMB). A post-AFP elevation was observed in 28 of 333 (8.4%) consecutive patients who before the procedure had preliminary placental localization by ultrasound and a normal serum AFP concentration (pre-AFP) for the gestational age.

Diagnosis of acute myocardial infarction in the emergency room: a prospective assessment of clinical decision making and the usefulness of immediate cardiac enzyme determination.

This study evaluates (a) the ability of house staff physicians to diagnose acute myocardial infarction (AMI) in patients with chest pain and (b) the usefulness of immediate ("stat") creatine kinase determinations in aiding the decision to hospitalize patients with chest pain. Of 80 emergency room patients with chest pain, 34 were admitted to an intensive care unit and 46 were either discharged or admitted to a general medical unit. Of the 34 patients admitted to intensive care, 11 fulfilled criteria for AMI.

The effect of the alkaline tide on serum-ionized calcium concentration in man.

The effect of the gastric alkaline tide on serum-ionized calcium levels was determined in human subjects. Gastric acid seretion was stimulated by a standard steak meal, human synthetic gastrin, and betazole hydrochloride. Ionized calcium levels fell to a similar extent after each stimulus.

Mechanism of release of endogenous cholecystokinin by jejunal amino acid perfusion in man.

Ertan et al have shown that the perfusion of the proximal jejunum with a mixture of amino acids (MAA) in physiological concentration releases endogenous cholecystokinin (CCK) in man. In the present experiment, we investigate the mechanism by which jejunal MAA perfusion mediates an increase in exocrine pancreatic and biliary secretions. The effects of a bolus of topical anesthetic (oxethazaine, 0.