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Background: The AACC Academy revised the reproductive testing section of the Laboratory Medicine Practice Guidelines: Evidence-Based Practice for Point-of-Care Testing (POCT) published in 2007. Methods: A panel of Academy members with expertise in POCT and laboratory medicine was formed to develop guidance for the use of POCT in reproductive health, specifically ovulation, pregnancy, premature rupture of membranes (PROM), and high-risk deliveries. The committee was supplemented with clinicians having Emergency Medicine and Obstetrics/Gynecology training. Results: Key recommendations include the following. First, urine luteinizing hormone (LH) tests are accurate and reliable predictors of ovulation. Studies have shown that the use of ovulation predicting kits may improve the likelihood of conception among healthy fertile women seeking pregnancy. Urinary LH point-of-care testing demonstrates a comparable performance among other ovulation monitoring methods for timing intrauterine insemination and confirming sufficient ovulation induction before oocyte retrieval during in vitro fertilization. Second, pregnancy POCT should be considered in clinical situations where rapid diagnosis of pregnancy is needed for treatment decisions, and laboratory analysis cannot meet the required turnaround time. Third, PROM testing using commercial kits alone is not recommended without clinical signs of rupture of membranes, such as leakage of amniotic fluid from the cervical opening. Finally, fetal scalp lactate is used more than fetal scalp pH for fetal acidosis due to higher success rate and low volume of sample required. Conclusions: This revision of the AACC Academy POCT guidelines provides recommendations for best practice use of POCT in fertility and reproduction. [ABSTRACT FROM AUTHOR]

Research was conducted to determine whether the differential inhibition of the Ca-ATPase in cardiac sarcoplasmic reticulum (SR) is caused by the presence of the regulatory protein phospholamban in cardiac SR. Different lipid environments in skeletal and cardiac SR or the different Ca-ATPase isoforms are present in the two tissues. Results establish a biochemical model for the mechanism of action of an anesthetic on a membrane protein and should lead to the identification of anesthetic binding sites on the skeletal and cardiac isoforms of the Ca-ATPase.

The effects of the nonionic detergent C12E8 on Ca-ATPase enzymatic activity and oligomeric state in skeletal and cardiac sarcoplasmic reticulum (SR) are investigated. Time-resolved phosphorescence anisotropy of skeletal SR at low and high Ca shows that C12E8 induces aggregation of ATPase monomers and small oligomers. C12E8 also aggregates the Ca-ATPase in cardiac SR at high Ca. C12E8 inhibits the ATPase when it aggregates the enzyme and the detergent activates when it dissociates ATPase oligomers.

Background: Reflex testing algorithms are effective tools to reduce unnecessary laboratory testing. Direct (conjugated) bilirubin (DB) and total bilirubin (TB) are often ordered together at our institution. Therefore, the objective of our study was to evaluate the potential impact of performing reflex testing for DB when TB is elevated. Methods: We performed a retrospective review of test orders (patients ≥18 years of age) for DB, TB, or for both DB and TB on the same accession number received in our stat laboratory from January through April 2017. The orders were binned into 4 categories depending on the results from each individual test: (a) DB normal and TB normal, (b) DB normal and TB high, (c) DB high and TB normal, and (d) DB high and TB high. The percentage of orders and median (range) test result for each category was calculated. Results: During the months evaluated, a total of 4828 stat orders were placed for DB, TB, or both DB and TB. A total of 4296 stat orders (89%) were placed with both DB and TB on the same accession number for 4158 unique patients. Of those orders, the vast majority of tests (87.3%) contained normal results for both analytes; only 12.7% of orders contained ≥1 abnormal result. Conclusions: The majority of all bilirubin tests ordered stat for emergency department and hospitalized patients have values within the reference interval. Consequently, if reflex testing were executed on elevated TB, a large number of DB tests could be avoided. [ABSTRACT FROM AUTHOR]

A study of the influence of cycloprizonic acid (CPA) and halothane on the oligomeric state, enzymatic activity and conformational equilibrium of Ca-ATPase in the sarcoplasmic reticulum (SR) of skeletal muscles using time-resolved phosphorescence anisotropy reveals that the proportion of dimers and larger aggregates of Ca-ATPase is enhanced by CPA. The observed K1 of CPA inhibition and proportion of monomeric CaATPase are enhanced by the addition of halothane to SR or by the solubilization of the enzyme. Measurements of the fluoroescein 5-isothiocyanate fluorescence and enzyme phosphorylation reveal that the E2 conformation of the enzyme is stabilized more than the E1 and E2-P states by CPA.