Recovered after an extreme bottleneck and saved by ex situ management: Lessons from the Alagoas curassow (Pauxi mitu [Linnaeus, 1766]; Aves, Galliformes, Cracidae).

A pivotal debate on biodiversity conservation is whether the scarce budgets must be invested in critically endangered taxa or in those with higher chances to survive due to larger population sizes. Addressing the fate of extremely bottlenecked taxa is an ideal way to test this idea, but empirical cases are surprisingly limited. The reintroduction of the extinct-in-the-wild Alagoas curassow (Pauxi mitu) by Brazilian scientists in September 2019 added to the two other known cases of survival to bottlenecks of only two or three individuals. We exploit the reasons why this species has survived, and we report how investments to rescue the Alagoas curassow resulted in the protection of many other taxa, suggesting that in the face of the dramatic number of extinctions expected for the Anthropocene, integration must prevail over a choice.

Evaluation of determination of glucose in urine with some commercially available dipsticks and tablets.

Four commercial products for urine glucose determination were evaluated and compared with a quantitative hexokinase procedure. We examined precision, sensitivity, and analytical recovery of glucose from glucose-supplemented urine samples and comparison of methods, using patients' samples. Only "Chemstrip uG" (Bio-Dynamics Inc.) could differentiate between 0.3 g/L (upper limit of normal) and 0.6 g/L urine glucose concentrations. "Tes-Tape" (Lilly) and "Diastix" (Ames) gave positive readings at 0.3 g/L; "Clinitest" (Ames) detected glucose only over 1 g/L. Analytical recovery of glucose was best, for all four products, between 1 and 2.5 g/L; Chemstrip uG was the most nearly accurate among the four. Between 5 and 20 g/L glucose concentrations, Tes-Tape, Diastix, and Clinitest tended to give falsely low results; the use of Chemstrip uG resulted in overestimates of concentration at 20 g of glucose per liter. Only Chemistrip uG and Clinitest (two-drop method) had linear ranges extending to 50 g/L; Chemstrip uG had better precision and accuracy at this concentration. Of the four products, Chemstrip uG had the lowest within-technologist and technologist-to-technologist random analytical errors. In method comparison on patients' samples, Chemstrip uG was significantly stronger in its association with the quantitative hexokinase method than was Diastix, Clinitest, or Tes-Tape.

Evaluation of clinical laboratory instruments. Part I: Defining laboratory needs.

The purchase of a new laboratory instrument can be an exciting challenge for a laboratory director or supervisor. Those responsible for making purchase recommendations should be objective and thorough. The skill with which they discharge this responsibility may affect laboratory performance and employee morale for several years. This paper explores some of the important considerations in purchasing instruments and suggests an approach to vendors to obtain information needed in making decisions.

Extended clinical trial and evaluation of urea nitrogen determination with the Ektachem GLU/BUN analyzer.

We followed the "abbreviated precision protocol" of the National Committee for Clinical Laboratory Standards for the evaluation of precision, accuracy, and carryover in analysis for urea nitrogen with the multilayer film analysis system ("Ektachem"). We analyzed 456 clinical samples with this instrument, by the manual urease/glucose dehydrogenase method, and with the Beckman System I GLU/BUN Analyzer. Precision and accuracy were estimated for 50, 220, 270, and 500 mg/L urea nitrogen concentrations in 100, 30, or 20 microL of serum. Potential interference of 15 compounds was evaluated. Random error (defined as 1.965 X SD) was 7, 10, 12, and 18 mg/L. Systematic error was 3, 4, 5, and 15 mg/L. Total analytical error was 11, 14, 17, and 34 mg/L for analysis of 100 microL of serum at the above-stated urea nitrogen concentrations. The greatest interference (6 mg/L) was caused by ethanol (300 mg/L) and by hemoglobin (500 mg/L) in the urea nitrogen (at 260 mg/L) determination. Urea nitrogen concentration, as determined with the Ektachem was linearly related to the expected concentration, at least up to 1187 mg/L. Carryover was not statistically significant.

Extended clinical trial and evaluation of glucose determination with the Eastman Kodak Ektachem GLU/BUN Analyzer.

We followed the "abbreviated precision protocol" of the National Committee for Clinical Laboratory Standards for the evaluation of precision, accuracy, and carryover in analyses for glucose with the "Ektachem." We analyzed 760 clinical samples by this technique, by the FDA Proposed Class Standard glucose reference method, and with the Beckman System I GLU/BUN Analyzer. Precision and accuracy were estimated for 500, 1000, 1200, 1500, and 3000 mg/L glucose concentrations in 100, 30, or 20 microL of serum or plasma. Potential interference of 19 compounds was evaluated. Random error (1.965 X SD) was 22, 30, 34, 40, and 88 mg/L. Systematic error was 8, 1.5, -2, -5, and -27 mg/L. Total analytical error was 30, 32, 36, 46, and 110 mg/L for analysis of 100 microL of serum at the above-stated glucose concentrations. The greatest interference (-39 mg/L) in the glucose (at 1200 mg/L) determination was caused by L-ascorbate (40 mg/L). Glucose concentrations as determined with the Ektachem were found to be linearly related to the expected concentration up to at least 5660 mg/L. Carryover was not statistically significant.

False-negative results for urinary phenothiazines and imipramine in Forrest's qualitative assays.

When a series of patients' urine samples supplemented in vitro with chlorpromazine or imipramine was assayed with the Forrest qualitative assays, we observed an occasional false-negative result, which we found was attributable to interference by ascorbic acid. It interferes with the reagent, not with the analytes, in both assays. We easily eliminated this interference with the phenothiazine test by using an anion-exchange resin. Eliminating the interference with the assay for imipramine, however, is more difficult; false-negative results can be obtained even after ion-exchange chromatography if the imipramine concentration is less than 50 mg/L.

Hemoglobinuria and hematuria: accuracy and precision of laboratory diagnosis.

Five methods of assessing blood in urine were studied and compared: sedimentation count, hemacytometry, "Clini-lab" reagent strip and "N-Multistix" and "ChemStrip-8" dipsticks. The minimum sensitivity of two commercially available urine dip-stick procedures for blood was established. The study includes method association, assay variation among and within technologists, accuracy, precision, and sensitivity. Our results demonstrate generally poor association between results by the dip-stick procedures and the hemacytometer or sedimentation count. Results by the last two procedures also showed very poor association with each other.

Creatine kinase isoenzymes of mitochondrial origin in human serum.

We measured creatine kinase (EC 2.7.3.2) activity in 1009 serum samples from 538 patients in the intensive-care units of the University of Texas Medical Branch hospitals. Creatine kinase isoenzymes migrating cathodal to skeletal muscle creatine kinase (CK-MM) on cellulose acetate electrophoresis were found in sera from 14 of the 538 patients. Creatine kinase, lactate dehydrogenase (EC 1.1.1.27), aspartate aminotransferase (EC 2.6.1.1), and alanine aminotransferase (EC 2.6.1.2) activities were abnormally increased in these 14 patients. Liver lactate dehydrogenase isoenzyme (LDH5) and cardiac creatine kinase isoenzyme (CK-MB) were abnormally increased in 12 and eight of these patients, respectively. Ten of the 14 patients died during their hospital admission. We believe the creatine kinase isoenzymes that migrated cathodal to skeletal muscle creatine kinase (CK-MM) were of mitochondrial origin.

Glucosuria: accuracy and precision of laboratory diagnosis by dip stick analysis.

Two urine dip-stick assays for glucose were studied and compared to a quantitative hexokinase procedure. We determined sensitivity, specificity, predictive value of "normal" and "abnormal" dip stick results, assay efficiency, technologist precision, and method association. Precision was poor. Attempts to estimate urine glucose concentration with the dip sticks frequently produced gross inaccuracies. We believe the dip stick glucose assay should be considered qualitative only; as a qualitative test, the dip sticks are fairly efficient at distinguishing glucose concentrations of less than 0.3 g/L from concentrations greater than 0.3 g/L.

Proteinuria: accuracy and precision of laboratory diagnosis by dip-stick analysis.

We studied and compared results of two urine dip-stick procedures for protein with those of quantitative measurements of total protein and albumin in urine. Sensitivity, specificity, and predictive value of "normal" and "abnormal" dip-stick results, assay efficiency, technologist precision, and method association were determined. Precision was poor, attributable largely to variation within each technologist. Relative to a defined measure of precision, technologist performance appears to be uniform within each product. Patients' urinary protein concentrations of less than 200 mg/liter can be distinguished from concentrations greater than 3000 mg/liter with confidence by dip-stick procedures. Urin samples with low albumin/total protein ratios were frequently falsely negative by dip-stick assays.

Urinary nitrite and urinary-tract infection.

Two dipstick procedures and an automated quantitative urinary nitrite assay were used to study nitrite in 786 samples of urine submitted to the bacteriology laboratory for routine culture and sensitivity testing. Many samples that had more than 100,000 nitrite-reducing organisms/ml and no detectable nitrite were studied. Limited nitrate concentration in urine was not a significant cause of false-negative nitrite results. However, in some urine samples nitrite added in vitro was lost during a four-hour incubation in vitro at 37 C in the presence of more than 100,000 nitrite-reducing organisms/ml. Ascorbic acid, abnormal amounts of urobilinogen, and urinary pH below 6.0 are all possible causes of false-negative nitrite determinations.

Accuracy and precision of urinary pH determinations using two commercially available dipsticks.

The accuracy and precision of urinary pH determinations using commercially available dipsticks were studied. Two products were evaluated by 17 MT(ASCP) technologists over the pH range 4.5 to 9.0. The study included accuracy, reproducibility, variation among technologists, and variation between products. The results demonstrated considerable variation among technologists, products, and true pH levels in dipstick urinary pH determinations, and that very good or very poor results could be obtained, depending on the true pH level being sampled and on the choice of technologist.

Hyperlipidemia in uremic children: response to peritoneal dialysis and hemodialysis.

Hemodialysis and hyperlipidemia have been associated in both adults and children. The present study indicates hyperlipidemia in uremic children treated with peritoneal dialysis and implies that the cardiovascular risk felt to exist with hemodialysis also exists in peritoneal dialysis. Thirty-eight children with chronic renal insufficiency or end-stage renal disease were followed serially under varying conditions of medical management, hemodialysis, peritoneal dialysis, and transplantation. Serum triglyceride concentrations in patients on peritoneal dialysis were not significantly different from those in patients on hemodialysis, but both were significantly higher (P less than 0.01) than concentrations in patients on medical management and transplantation.

Evaluation of the Du Pont aca alpha-amylase procedure.

The procedure used with the Du Pont aca for alpha-amylase (1,4,-alpha-D-glucan glucanohydrolase, EC 3.2.1.1) was evaluated in our laboratory and compared with the Roche Diagnostics "Amylochrome" and Perkin-Elmer Coleman 91 amylase assays. The within-run coefficients of variation (CV) for samples of fresh normal sera were: aca 5.8% and 4.3% on two different lots of reagent, Amylochrome 7.4%, and Coleman 91 3.3%. In sera with abnormally high amylase activity, the respective CV's were: aca, 1.2% and 0.8%; Amylochrome, 2.0%; and Coleman 91, 2.8%. Day-to-day precision studies on fresh and lyophilized normal and abnormal sera gave CV's in the following ranges: aca, 1.8% to 6.7%; Amylochrome, 3.0% to 5.2%; and Coleman 91, 4.5% to 5.9%. Results by the aca procedure were linearly related to activity to about 10-fold the upper limit of normal amylase activity. For serum, correlations were: r = 0.977 for aca vs. Coleman 91 and r = 0.974 for aca vs. Amylochrome. For urine they were: r = 0.978 for aca vs. Coleman 91 and r = 0.975 for aca vs. Amylochrome. Mean recovery from 53 supplemented samples was 98%. Icterus, hemolysis, and lipemia did not interfere with method correlation of aca vs. Coleman 91 or Amylochrome.