A comparison of serum electrolyte results by Technicon's Flame III and Flame IV AutoAnalyser system

A comparison of Technicon's (Technicon, Tarrytown, N. Y., 10591) Flame III and Flame IV electrolyte Auto-Analyzer systems for the determination of Na+, K+, Cl- and CO2 in serum is described. Results from the Flame IV are determined over three periods of time and compared to those of the referee Flame III system. The Optional Digital Printer and Linearizer Modules are not used with the described system. The Flame IV AutoAnalyzer is calibrated with a multi-point calibration technique (aqueous reference standards) rather than the single-point calibration technique (albumin reference material) used by the AutoAnalyzer II. Results for the Flame IV are shown to be comparable with those for the Flame III.     

An algorithm for calculating and analyzing the dissociation curves of human blood oxyhemoglobin standardized by 2 and 3 allosteric ligands

An algorithm of an "OXYHEM" programme intended for standardization of experimentally changed human blood oxyhemoglobin dissociation curves by two (H+, CO2) and three (H+, CO2, 2,3-DPG) allosteric ligands is presented. In the former case all the points of the curve are adjusted to the values of pH--7.4, pCO2--40 mmHg, while in the latter case--to values of pH--7.4, pCO2--40 mmHg and 2,3-DPG concentration 5 mmol per 1 of PBC. Every standardized curve makes it possible to determine P50, Hill's ratio, arteriovenous difference by O2 saturation and content. A comparative analysis of the parameters calculated presents a wide range of data reflecting the state of oxygen transport hemoglobin function in the studied blood.     

Enzymatic method for determination of CO2 in serum.

We describe an enzymatic method, requiring only 10 mul of serum, for determining CO2 as bicarbonate or dissolved gas. Phosphoenolpyruvate carboxylase catalyzes the reaction of HCO3- with phosphoenolypyruvate to give oxalacetate. The resulting NADH, in the presence of malate dehydrogenase, is oxidized to NAD+, and the decrease in absorbance at 340 nm is directly proportional to the amount of CO2 present in the sample. Reaction is complete in 3 to 6 min under assay conditions, and is linearly related to CO2 concentrations between 8 and 65 mmol/liter. Analytical recovery is 95-110% (average, 101%). Two laboratories compared values obtained by continuous-flow analysis. The resulting correlation coefficients were 0.966 and 0.987, values for the t-test were t(paired) equals 0.473 and t(paired) equals 0.334, and average day-to-day precisions (three concentrations) were 3.9% and 4.2%.     

Development of an aqueous temperature-indicating technique and its application to clinical laboratory instrumentation.

We describe a new technique for monitoring intra-cuvette temperatures in temperature-controlled spectrophotometric cells by use of two solutions, one for which absorbance is highly sensitive to temperature and one for which absorbance is insensitive to temperature. The first solution, cresol red in tris(hydroxymethyl)aminomethane buffer, is used to construct an absorbance-vs.-temperature calibration curvae. The second solution, cresol red in sodium hydroxide, is used for optical calibration of the spectrophotometric system to be tested. The combination of these two procedures allows accurate estimation of temperature. We show how this technique is applied to temperature measurement in several types of laboratory instrumentation.     

Comparison of methods to wash liquid-stored red blood cells and red blood cells frozen with high or low concentrations of glycerol

The efficiency of washing liquid-stored red blood cells and red blood cells frozen with high or low glycerol concentrations was evaluated by measuring the recovery of red blood cells in vitro, supernatant hemoglobin, extracellular potassium and red blood cell potassium levels, supernatant osmolality, residual 125I albumin, glycerol, hypoxanthine, and di-2-ethylhexyl phthalate (DEHP) levels. Four commercial washing systems were studied, three which used sodium chloride solutions with serial or continuous-flow centrifugation and one which used sugar solutions and dilution/agglomeration. Washing was most efficient using sodium chloride solutions in the IBM Blood Processor, an automated serial centrifugation procedure and in the Fenwal Elutramatic, a continuous-flow centrifugation procedure. Less efficient washing was achieved in the Haemonetics Processor 15, a continuous-flow centrifugation procedure and the least efficient washing occurred using the original and modified dilution/agglomeration procedures. To achieve the most efficient washing, three principles must be utilized: concentration of the red blood cells to hematocrit values of 90 per cent, prior to washing or freezing. Liquid-stored red blood cells concentrated to hematocrit values of 90V per cent should be diluted with hypertonic sodium chloride solutions prior to recovery and washing. Red blood cells containing 20 per cent or 40 per cent W/V glycerol should be diluted with hypertonic sodium chloride solutions before recovery and washing. Finally, on-line dilution should be achieved in the washing systems that use continuous-flow centrifugation.     

The purification of red cells for transfusion by freeze-preservation and washing. V. Red cell recovery and residual leukocytes after freeze- preservation with high concentrations of glycerol and washing in various systems

Red blood cells freeze-preserved with 40% W/V glycerol in an ionic or low ionic medium at −80 C were washed in one of four commercially available systems: the Haemonetics Blood Processor 15 using a continuous-flow centrifugation procedure, the Fenwal Elutramatic using a continuous-flow centrifugation procedure, the IBM Blood Processor using an automated serial centrifugation procedure, and the Huggins Cytoglomerator using a dilution/agglomeration procedure. Determinations of red blood cell recovery and leukocyte and platelet removal were made for each of these groups. The dilution/agglomeration procedure produced lower red blood cell recovery values and poorer leukocyte and platelet removal than did any of the three wash systems using sodium chloride solutions. The values obtained with the systems using sodium chloride solutions were slightly but significantly different.     

Validation of a computational platform for the analysis of the physiologic mechanisms of a human experimental model of hemorrhage

Computational models of integrative physiology may serve as a framework for understanding the complex adaptive responses essential for homeostasis in critical illness and resuscitation and may provide insights for design of diagnostics and therapeutics. In this study a computer model of human physiology was compared to results obtained from experiments using Lower Body Negative Pressure (LBNP) analog model of human hemorrhage. LBNP has been demonstrated to produce physiologic changes in humans consistent with hemorrhage. The computer model contains over 4000 parameters that describe the detailed integration of physiology based upon basic physical principles and established biologic interactions. The LBNP protocol consisted of a 5 min rest period (0 mmHg) followed by 5 min of chamber decompression of the lower body to −15, −30, −45, and −60 mmHg and additional increments of −10 mmHg every 5 min until the onset of hemodynamic decompensation (n = 20). Physiologic parameters recorded include mean arterial pressure (MAP), cardiac output (CO), and venous oxygen saturation (SVO₂; from peripheral venous blood), during the last 30 s at each LBNP level. The computer model analytic procedure recreates the investigational protocol for a virtual individual in an In Silico environment. After baseline normalization, the model predicted measurements for MAP, CO, and SVO₂ were compared to those observed through the entire range of LBNP. Differences were evaluated using standard statistical performance error measurements (median performance error (PE) <5%). The simulation results closely tracked the average changes observed during LBNP. The predicted MAP fell outside the standard error measurement for the experimental data at only LBNP −30 mmHg while CO was more variable. The predicted SVO₂ fell outside the standard error measurement for the experimental data only during the post-LBNP recovery point. However, the statistical median PE measurement was found to be within the 5% objective error measure (1.3% for MAP, −3.5% for CO, and 3.95% for SVO₂). The computer model was found to accurately predict the experimental results observed using LBNP. The model should be explored as a platform for studying concepts and physiologic mechanisms of hemorrhage including its diagnosis and treatment.     

Curve prediction in automated analyses in routine laboratories.

1. The hydraulics of first- and second-generation AutoAnalyzers introduce lag and exponential deformations of the square wave signal expected from the colorimeter. These factors limit sampling rates by causing sample interaction. Curve regeneration carried out on Technicon Flame IV modules, using a digital approach, with a Hewlett-Packard 2100A computer, has successfully compensated for exponential deformation of sodium, potassium, chloride and carbon dioxide channels in routine laboratory use for one year. A sampling rate of 138/hr has been used; faster rates are possible. 2. Reduced sample and reagent consumption are benefits in addition to the increased analysis rate.     

Human cigarette smoking: effects of puff and inhalation parameters on smoke exposure

This study determined effects of three smoking behavior components: puff volume, inhalation volume and lung exposure duration on biological measures of smoke exposure. A microcomputer-based auditory feedback system allowed subjects (N = 9 or 10 per experiment) to control puff and inhalation parameters as they smoked usual brand cigarettes. In each of four experiments, one smoking parameter was manipulated across sessions while two other parameters were held constant. Biological samples were obtained before and after each 8-puff smoking session conducted under a given set of behavioral parameters for analysis of plasma nicotine and expired air carbon monoxide (CO) levels. In Experiment I, both nicotine and CO levels were influenced systematically as puff volume was varied from 15 to 60 ml (inhalation volume = 50% of vital capacity, lung exposure time = about 9 sec). Nicotine boost (post- minus presession levels) increased 4-fold and CO boost increased 9-fold over this range of puff volume values. In Experiment II, nicotine levels were unaffected when average lung exposure times varied from 5 to 21 sec (puff volume = 50 ml, inhalation volume = 50% of vital capacity), suggesting that all the nicotine available may be absorbed during a normal smoking inhalation cycle with no breathholding. CO levels increased systematically with longer breathholds. In Experiments III and IV, inhalation volumes from 10% and 20% to 60% of vital capacity had no effect on either nicotine or CO levels, and this was true whether lung exposure time was about 8 sec (Experiment III) or about 4 sec (Experiment IV). This series of studies has shown that puff volume is an important determinant of tobacco smoke exposure, but that inhalation components of smoking behavior, at least within the range of parameters tested, have no effect on nicotine exposure levels.     

New Colorimetric reaction for end-point, continuous-flow, and kinetic measurement of urea.

A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 mu-l of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good sensitivity. A major advantage of the reaction is that it occurs at a temperature of 37 degrees C or lower. The results obtained by all three methods agree well with those for a continuous-flow procedure in which diacetyl is a reagent.     

Interrelations in the Oxidative Metabolism of Free Fatty Acids, Glucose, and Glycerol in Normal and Hyperlipemic Patients A COMPARTMENTAL MODEL

Palmitate, glucose, and glycerol oxidation to CO(2) have been investigated in the fasted state in ten normal subjects and nine patients (six hyperlipoproteinemias, one xanthomatosis, and two glycogenosis) after intravenous injection of [1-(14)C]palmitate, [1-(14)C]glucose, or [1-(14)C]glycerol in tracer amounts. The specific activities and concentrations of plasma palmitate, glycerol, or glucose and expired CO(2) were measured at various intervals after the injection for a period of 24 h. All the studies were analyzed in terms of a multicompartment model describing the structure for each of the subsystems, the transfer of carbon label between subsystems, and the oxidation to CO(2). A bicarbonate subsystem was also included in the model to account for its role in shaping the CO(2) curves.All the CO(2) activity following a palmitate injection could be accounted for by a direct oxidative pathway from plasm FFA with the addition of a 20-min delay compartment. The same also applied to glucose, except that the delay compartment had a mean time of about 150 min. Only about a third of the injected glycerol was directly oxidized to CO(2) from plasma; the delay time was about 4 min. Most of the remainder was converted to glucose.In normals about 45% of the FFA is oxidized to CO(2) directly. This constitutes about 30% of the total CO(2) output. In hyperlipemia the CO(2) output is nearly unchanged and the contribution from FFA is nearly the same. There is a considerable increase (factor of 2), however, in FFA mobilization, most of which is probably diverted to triglyceride synthesis.The glucose and glycerol subsystems are roughly the same in normals and hyperlipemics. About 50% of glucose is oxidized by the direct pathways which accounts for about 35% of the CO(2) output. Glycerol accounts for only 1.5% of the CO(2) produced.Major changes occurred in the glycerol and glucose subsystems in glycogenosis. The changes are consistent with the known deficiency in glucose-6-phosphatase in this disorder. There is a considerable reduction (factor of 2 or more) in the release of glucose to plasma (gluconeogenesis) and in the conversion of glycerol to glucose.Despite the integration of the kinetics of the glucose, glycerol, and FFA subsystems over a 24-h period, 36% of the CO(2) production was still unaccounted for in normals and 50% in hyperlipemics. Thus, some of the carbon must wind up in very slowly turning-over pools which supply CO(2) through subsystems not covered in these studies (triglycerides, glycogen, amino acids, etc.).All the modeling was carried out with the aid of the SAAM25 computer program.     

The aminopyrine breath test as a measure of liver function. A quantitative description of its metabolic basis in normal subjects

The APBT is used widely as a measure of liver function. The development of the APBT into a liver function test of greater diagnostic value requires quantitative information on the processes involved in aminopyrine disposition and metabolism in man and on how APBT values reflect changes in these processes. A dual-isotope kinetic study of aminopyrine disposition and metabolism has been carried out on five normal adult subjects. Oral administration of 13C-aminopyrine (2 mg/kg) accompanied by simultaneous intravenous injection of 14C-aminopyrine was followed by serial measurements of aminopyrine and monomethylaminopyrine in plasma and urine over 6 hr. Timed collections of respiratory CO2 were analyzed for the content of excess 13CO2 and for 14CO2. On separate days, an intravenous bolus of 13C-labeled NaHCO3 was administered to obtain estimates of the kinetic parameters of CO2 elimination in each subject. These data were fitted simultaneously to a multicompartmental model that, in addition to providing hitherto unavailable quantitative information, has revealed that (1) demethylation is the major elimination pathway for aminopyrine; (2) a major alternative pathway not involving demethylation exists for monomethylaminopyrine; and (3) only 50% of the labeled carbon generated by demethylation eventually is oxidized to HCO3-. The sensitivity of seven types of APBT scores to 50% reductions in the rates of aminopyrine absorption, metabolism of monomethylaminoantipyrine, intermediate carbon metabolism, and bicarbonate kinetics was evaluated with breath test curves simulated using the APBT model. Every APBT score currently in use was affected by variations in both gastrointestinal output of aminopyrine and bicarbonate kinetics. There is a need for further development of selective scoring methods in the aminopyrine breath test.     

Characterization of type IV collagen NC1 monomers and Goodpasture antigen in human renal basement membranes.

Monomeric subunits of the globular domain of type IV collagen from human renal basement membrane were isolated and characterized. The monomers, M24, M26, M28+, and M28 , which have been identified previously in human glomerular basement membrane, were characterized by amino acid analysis, amino-terminal sequencing, and electrophoretic mobility. The results indicate that M24 and M26 are derived from alpha 1(IV) and alpha 2(IV) collagen chains, respectively. Amino-terminal sequencing revealed that M28+, and M28 correspond to the globular domain of novel collagen chains. M28 has been characterized as the principal target antigen in Goodpasture's syndrome and antiglomerular basement membrane (GBM) nephritis, and both M28 species are absent from the GBM in Alport familial nephritis. The cationic charge of M28 appears to be a consequence of a relatively high concentration of basic amino acids when compared with other monomers. Previous studies of bovine GBM have demonstrated chains with amino-terminal sequence homology to M28+ and M28 .     

Quantification of antibiotic drug potency by a two-compartment radioassay of bacterial growth.

The two-compartment radioassay for microbial kinetics based on continuous measurement of the 14CO2 released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial 14CO2 liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and tetracycline. The implications of dose-response curves are discussed on the basis of the receptor site concept for drug action. The assay sensitivities for chloramphenicol and tetracycline were similar to those obtained by the cell counting method, but the sensitivity of the radioassay was at least 10 times greater for spectinomycin.     

Trend detection in control data: optimization and interpretation of Trigg's technique for trend analysis.

A method for trend detection, Trigg's technique [Oper. Res. Q. 15, 271 (1964)], has been investigated for use in monitoring trends in control data produced by multitest continuous-flow analyzers. Simulated trend data were used to optimize the method. Actual control data were analyzed retrospectively to determine the frequency of trends and the accuracy of several parameters obtained from Trigg's method. The prospective use of the technique has successfully uncovered important trends. Criteria for the interpretation of the Trigg's trend data are suggested and an algorithm for the computer implementation of Trigg's calculations is included.     

A limited protocol for assessment of within-batch performance of multichannel analysers

An experimental protocol is described to evaluate rapidly the performance of biochemical analysers. A trial in which this protocol was applied to 15 multichannel continuous-flow analysers is described and the results are discussed. Some consideration is given to the effects of applying a commonly-used drift correction procedure to the raw data, and values of within-batch standard deviation are proposed which may be useful in assessing performance.     

Removal of specific antibody in vivo by whole blood immunoadsorption: preliminary results in dogs

Effective immunoadsorption for removal of anti-red cell antibodies from plasma using affinity columns has been demonstrated. However, the requirement of a continuous-flow centrifuge to separate plasma increases the cost and complexity of the procedure. We have adapted red cell antigen immunoadsorption columns for use with whole blood. Effective and specific removal of anti-red cell antibodies was achieved in actively immunized dogs.     

Continuous-flow leukapheresis for rapid cytoreduction in leukemia

Three patients with leukemia were treated for acute leukostasis using the continuous-flow cell separator. The first patient, treated with a standard procedure sustained only a 14 per cent decrease in leukocyte count even though 50 × 10(10) leukocytes were removed. A more aggressive approach was taken with the second two patients by increasing the rate of leukocyte removal three- to fourfold. In these patients, 100 to 230 × 10(10) leukocytes were removed and prepheresis counts dropped by 48 to 85 per cent. Both had satisfactory clinical response to pheresis. The data suggest that an aggressive pheresis can effectively treat symptoms associated with acute leukostasis. Finally, the continuous-flow cell separator has distinct advantages over the discontinuous-flow separator in patients with small blood volumes.     

骨蜡与再生氧化纤维素材料在老年女性心内直视术胸骨止血中的应用

背景:再生氧化纤维素已成功应用于神经外科、耳鼻喉科等手术止血中,效果确切,但应用于心脏手术胸骨止血尚未见报道。目的:对比观察再生氧化纤维素与传统胸骨止血材料骨蜡在减少老年女性心内直视术后胸骨出血中止血及预防胸骨感染效果的差异。方法:纳入68例60岁以上女性接受正中开胸体外循环下心内直视术患者,分为2组:再生氧化纤维素组胸骨创面及骨髓腔内填充并覆盖再生氧化纤维素,对照组涂抹医用骨蜡。记录手术时间、关胸时间、体外循环时间、术后引流量、输血量、出血再次开胸例数、平均住院时间、胸骨裂开例数、胸骨感染例数、切口拆线时间以及切口感染例数。结果与结论:两组术后在手术时间、关胸时间、引流量、输血量、出血再次开胸方面,差异有显著性意义(P<0.05),再生氧化纤维素组更有优势;其余指标两组差异无显著性意义。提示再生氧化纤维素作为新型胸骨止血材料,可常规用于体外循环后胸骨创面止血,效果确切,近期结果观察显示安全性较高。     

A preliminary report on the Stone-Kaplan instrumentation for CO 2 laser periodontics. Phase I: periodontal pocket opening surgical procedure

A preliminary report on the Stone-Kaplan instrumentation for CO 2 laser periodontics is presented describing the instrumentation and introducing the first phase of its clinical usage. The design enables the introduction of a hollow fiber delivered CO 2 laser beam into the depth of a periodontal pocket enabling invasive surgical procedures to be carried out with exacting control of the laser beam as afforded by the design of the instrumentation. This design enables the performance of pocket-opening surgical procedures with ease of performance for the operator enhanced by the "instrument-in-hand" tactile-feedback and blind-visualization phenomena afforded by this unique design. The basic performance for a periodontal pocket opening procedure is presented here.