Stability of alpha-tocopherol: pre-analytical conditions in its determination in blood samples

Some amides, 1-substituted methylenediamines and 2-substituted thiazolidin-4-ones, all containing the aminopyrazinyl moiety, were synthesized and tested in the experimental models of acute and chronic inflammations and as potential analgesic agents. The first series of compounds are inactive, whereas the N,N'-di-(2-pyrazinyl)-methylene-diamines and the 3-(2'-pyrazinyl)-thiazolidinones 6, 7, 11, 12 and even more 16 and 17 were found to be endowed with antiinflammatory and analgesic properties and low acute toxicity, the two latter being the most interesting.     

Sources of error in glucose determinations in neonatal blood by glucose oxidase methods, including Dextrostix

An investigation was carried out to examine why a glucose oxidase-peroxidase-orthodianisidine method for plasma glucose, without protein precipitation, gave low results for neonatal blood. The magnitude of the difference between the results with and without protein precipitation was examined in a clinical neonatal series, and in sera to which bilirubin, hemolysate, pure hemoglobin, and uric acid had been added. Systematic linear inhibition was demonstrated with bilirubin, and the results suggested that high concentrations of hemolysate and uric acid could also interfere. Use of alkaline protein precipitants eliminated the inhibition. Dextrostix test results for neonatal blood are compared with results of conventional glucose analyses and possible sources of discrepancy examined.     

烟气脱硫石膏粉化学物相分析

介绍了燃煤发电厂产出的烟气脱硫石膏粉中的化学组分分析方法。根据烟气脱硫石膏粉的特性,采用X射线能谱(EDS)仪对样品进行半定量分析,样品经过水洗去除50%的主成分后,不溶于水的物质用X射线衍射（XRD）仪进行定性分析,根据定性和半定量的分析结果,采用电感耦合等离子体原子发射光谱(ICP-AES)法、离子色谱(IC)法和重量法进行元素和组分的定量分析,综合分析结果,确定了烟气脱硫石膏粉是由82.2% CaSO₄·0.5H₂O,3.0% CaCO₃,1.0% CaMg(CO₃)₂,11.1% SiO₂,1.4% Al₂SiO₅和1.3% Fe₂O₃组成。     

Determination of pH in human erythrocytes. Sources of systematic error

To develop serum-free (SF) media for the production of humanized antibody from recombinant Chinese hamster ovary (rCHO) cells, a statistical optimization approach based on a Plackett-Burman design was adopted. A basal medium was prepared by supplementing alpha-minimal essential medium (alpha-MEM) with Fe(NO3)3.9H2O, CuCl2, ZnSO4.7H2O, and Na2SeO3 which are generally contained in SF medium formulations. Insulin, transferrin, and ethanolamine were also supplemented to the basal medium to determine their optimal concentrations. From this statistical analysis, serine, phenylalanine, and tyrosine were identified as important determinants for cell growth. Also, putrescine, linoleic acid, and hydrocortisone were shown to be important for both cell growth and antibody production. The SF medium was formulated by supplementing the basal medium with components showing positive effects on cell growth and/or antibody production. Cell growth and antibody production in this SF medium were comparable to those in alpha-MEM supplemented with 5% dialyzed fetal bovine serum. Taken together, the results obtained here show that a Plackett-Burman design facilitates the development of SF media for rCHO cells aimed at producing a humanized antibody.     

Stress test blood gas analysis in chronic obstructive lung diseases

This study was conducted to investigate the clinical value of blood gas analysis during exercise in patients with COPD and healthy controls using the new criteria of the Deutsche Gesellschaft für Pneumologie (DGP) for performance and interpretation of blood gas analysis during exercise. A total of 64 patients with COPD (age: 63.7 +/- 10.1 years) and 35 healthy controls (age: 35.0 +/- 14.3 years) exercised on a bicycle ergometer to their submaximal capacity under steady state conditions (patients: 44.4 +/- 24.6 watt vs. 102.4 +/- 32.1 watt; p < 0.01). A pathological response for PaO2 occurred in 3 of 35 controls (8.6%) and 14 of 64 patients (21.9%; p < 0.01). A decrease in PaO2 yielded a sensitivity of 28% and a specificity of 92% in respect of patients with emphysema. Significant associations of lung function parameters at rest and blood gases under exercise were found by linear regression analysis (airway resistance (Rt): beta = -0.48; p < 0.001) and PaCO2 (FEV1: beta = -0.27; p < 0.05). This study demonstrates that in patients with COPD parameters of lung function and blood gas analysis at rest are already good predictors of gas exchange under exercise conditions. In individual cases, however, prediction may not be possible. This underlines the importance of the exercise test to investigate gas exchange under diagnostic (i.e. dyspnoea, medical opinion) and therapeutic aspects (i.e. therapy control). For COPD patients, the rule of the DGP yielded a poor sensitivity, but an excellent specificity in the diagnosis of emphysema, which yields confirmation of the diagnosis only in conjunction with, and complementary to, other methods.     

On-line determination of pulmonary blood flow using respiratory inert gas analysis

An inert gas analysis method has been developed to perform on-line real time determination of pulmonary blood flow using a nonrebreathing approach. This technique is based on a mathematical model describing mass balance of two inert gases which are breathed using an open gas circuit. The measurements using this method are noninvasive, easy to peform, and do not disturb normal physiological processes. As well, since data are collected on a breath-by-breath basis, it is possible to estimate other respiratory, cardiopulmonary, and metabolic parameters simultaneously in a breath-by-breath manner. Special consideration was given to developing effective data processing algorithms to minimize the influence of measurement noise and respiratory variations. Experimental studies to compare this method with other accepted techniques were conducted to validate the present technique.     

Influence of the blast on the gas phase in the blast-furnace hearth

Changes in the properties of the blast and the corresponding hearth gases in the blast furnace are considered—specifically, changes in the chemical composition, density, viscosity, specific heat, and thermal conductivity. The results are plotted. The conclusion is that, with increase in oxygen content in the blast, the properties of the hearth gas are improved. That offers interesting possibilities for the blast-furnace production of steel.     

Sources of lead in blood. Identification by stable isotopes

The isotope ratios of lead in the blood of ten subjects resident in Dallas, Texas, were measured from April 1974 to June 1975. During the same period, the ratios in the city's air changed linearly by 6%. One subject gave erratic results, but the remainder yielded ratios that changed systematically--some linearly, others cyclically with turning points occurring in August to October and February to April. Two South African subjects were 6 months out of phase with their U.S.-born wives and the other U.S.-born subjects. Since the South Africans are presumed to have in their skeletons lead that is isotopically distinct from that in the U.S. environment, the cycles are attributed to the mixing of skeletal and dietary lead. The dietary component is inferred to be greatest in August to October, which correlates with the time at which 25-hydroxyvitamin D is reported to have maximum concentration in blood. On the assumption that the isotope ratios of dietary leads remained constant, the proportion of airborne lead in the blood of those subjects whose ratios changed linearly could be calculated, and values between 7 +/- 3% and 41 +/- 3% were obtained.     

固相微萃取-气相色谱法测定煤气中萘

采用特制采样瓶收集煤气后,应用固相微萃取(SPME)对样品进行前处理,采用气相色谱(GC)对煤气中的萘进行测定。通过试验确定了SPME的最佳萃取条件为:采用100 μm聚二甲基硅氧烷(PDMS)萃取涂层,于转速为800 r/min时室温下萃取5 min,气相色谱解吸时间为3 min。在丙酮溶剂峰存在的情况下,基线平稳,丙酮峰对萘的测定并无影响。实验结果表明,萘在5～200 mg/m³范围内有良好的线性关系,相关系数为0.999 9。方法检出限为0.08 mg/m³。实验方法用于煤气中萘的测定,相对标准偏差(RSD,n=7)为2.6%～4.9%,加标回收率为85%～108%。     

Quantitative analysis of acetaldehyde in whole blood from human and various animals by gas chromatography

Acetaldehyde present in the blood of bull, chicken, hamster, horse, human, monkey, pig, rabbit, rat and sheep, was quantitatively analyzed by a newly developed gas chromatographic method. Acetaldehyde in a blood sample was reacted with cysteamine to give 2-methylthiazolidine, which was extracted with dichloromethane and subsequently analyzed by gas chromatography with a fused-silica capillary column and a nitrogen-phosphorus detector. The quantities of acetaldehyde found in blood ranged from 2.04 micromol/ml (hamster) to 14.8 micromol/ml (pig). The quantity of acetaldehyde recovered from human blood was 6.17 micromol/ml.     

The changes of blood gas analysis values and platelet aggregability on acute phase in the experimental model of pulmonary embolism prepared by sephadex G-75 (SG-75) injection

To study pathophysiologic phenomena in acute pulmonary embolism, we injected sephadex G-75 (SG-75) into rabbit auricular veins and measured the changes in blood gases and in platelet aggregability. Severe hypoxemia developed within 10 minutes of SG-75 injection. Microscopic examination of samples taken 120 minutes after SG-75 injection pulmonary artery had been embolized by the SG-75 particles, and that thrombin had formed around the particles. The lowest platelet counts were measured 10 minutes after SG-75 injection. The rates of platelet aggregation induced by adenosine diphosphate and by platelet-activating factor were abnormally low until 40 minutes after SG-75 injection. These results suggest that platelets were activated by anoxia and that the activated platelets moved around the emboli after obstruction of the pulmonary artery. We conclude that decreases in PaO2 and changes in platelet aggregability exacerbate the pathophysiologic processes in acute pulmonary embolism.