Comparison of 2 isotope-nephrography-evaluation methods in normal pregnancy

The isotope nephrograms of a total of 31 renally healthy pregnant women of different thirds of pregnancy are semiquantitatively investigated by 2 methods. The results are demonstrated graphically. This comparison show that a more correct result can be made with the describing method by taking a greater number of parameters describing the excretory phase.     

Intercomparison of analytical methods for arsenic speciation in human urine

An intercomparison exercise was conducted for the quantification of arsenic species in spiked human urine. The primary objective of the exercise was to determine the variance among laboratories in the analysis of arsenic species such as inorganic As (As+3 and As+5), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Laboratories that participated had previous experience with arsenic speciation analysis. The results of this interlaboratory comparison are encouraging. There is relatively good agreement on the concentrations of these arsenic species in urine at concentrations that are relevant to research on the metabolism of arsenic in humans and other mammals. Both the accuracy and precision are relatively poor for arsenic concentrations of less than about 5 micrograms/l.     

Comparison by ELISA of serum anti-Candida albicans mannan IgG levels of a normal population and in diseased patients

A method is described for estimating the degree of genetic variability between parents and offspring for polygenic traits. Dermatoglyphic pattern elements on fingertips palms, and soles illustrate the method and the quantitative contribution of each sex was determined.     

Treatment of HCV positive individuals with normal serum ALT levels

A substantial number of cases of chronic hepatitis C infection can be shown to have normal or near normal serum ALT levels. Major questions that arise when such cases are seen are: should such patients be treated; if so for how long; and what is the end point of therapy. The reported experience of such patients treated by IFN is reviewed.     

锗的分析方法进展

介绍了自1994年以来,测定锗的多种分析方法,主要内容包括:光度法,原子吸收法,极谱法,荧光法和其它方法。引用文献131篇。     

Determination of drug levels in human serum by circular dichroism

Cryopreserved skin must be used immediately after thawing or discarded owing to rapid post-thaw deterioration in viability. This is inconvenient and wasteful. The purpose of this study was to evaluate whether release of protease enzymes from cryogenically damaged cells or the action of free radicals on skin cells, is the cause of this deterioration. Following thawing. skin was incubated for 24 h at 4 degrees C in a range of protease inhibitors and free radical inhibitors/scavengers. The rate of deterioration was significantly reduced by using complex treatments including addition of serum, egg white and raised pH. These treatments are known to inhibit various groups of protease enzymes but would clearly have additional effects on the cells. Of the remaining treatments most of the specific protease inhibitors improved viability although not significantly. Treatments designed to inhibit or scavenge free radicals had little or no effect.     

Hemolysis of normal human erythrocytes by autologous serum complement

Unsensitized normal human erythrocytes (E) were shown to be lysed when incubated with autologous serum in the presence of zymosan (Zy). The hemolysis proceeded slowly with a relatively constant rate for at least 24 h at 37 degrees C. It was shown that the hemolytic reaction is antibody independent and mediated by complement activation through the alternative pathway and that hemolysis is not due to the decay or inactivation of complement regulators present on the E membrane. The mechanism of the phenomenon was studied by use of several kinds of sera genetically deficient in C3, C5, C7 or C9. The reaction was found to be divided into two stages: in the first step, neither E, C5, C7 nor C9 but Zy, serum factors containing C3 and metal ions are necessary, and in the second step, neither C3 nor metal ions but E, C5, C7 and C9 are necessary. Thus, E seem to be lysed by reactive lysis induced by C5 convertase formed on Zy through alternative complement pathway activation.     

Calculation of serum digoxin levels in patients with normal and impaired renal function

Serum digoxin levels were examined in 55 patients with varying degrees of renal function impairment who were receiving chronic oral digoxin therapy. Three methods of predicting digoxin serum levels were investigated. Each method may be applied using serum creatinine values and does not require urinary data. Correlations between calculated and actual digoxin levels in combined male and female patients were improved when changes in digoxin distribution volumes in renal impairment were considered. Correlations between calculated and actual digoxin levels were poor in male patients but were again improved by incorporating changes in drug distribution volume. Correlations obtained in female patients were superior to those obtained in male patients and appeared to be independent of the method of calculation employed.     

Polyamine evaluation in serum and erythrocytes of pediatric patients with neoplasms

A major allergen/antigen, Asp fl, secreted by Aspergillus fumigatus exhibits cytotoxicity towards eukaryotic cell lines. Asp fl inhibited protein synthesis in RAW cells with an IC50 of 4.5 nM and also degraded ribosomal RNA of RAW cells at a similar concentration. Ribosomal inactivation by Asp fl may be the probable mechanism for protein synthesis inhibition. Specific ribonuclease activity of Asp fl was observed to be 100,000 U/mg. Presence of strong RNase activity in Asp fl was further confirmed by agar gels containing yeast RNA. Electrophoretic run on agarose gels showed that Asp fl degrades all species of naked RNA. Modification of histidine residues of Asp fl with diethyl pyrocarbonate and alkylation of cysteines with iodoacetamide resulted in loss of ribonuclease activity and cytotoxicity of Asp fl. The current study establishes the ribonuclease activity of a purified major allergen of A. fumigatus that inhibits protein synthesis and kills the eukaryotic cells.     

Effects of prolonged hyperinsulinemia on serum leptin in normal human subjects

We have studied the effect of prolonged hyperinsulinemia and hyperglycemia on serum leptin levels in young nonobese males during 72-h euglycemic-hyperinsulinemic and hyperglycemic ( approximately 8.5 and 12.6 mM) clamps. Hyperinsulinemia increased serum leptin concentrations (by RIA) dose-dependently. An increase in serum insulin concentration of > 200 pM for > 24 h was needed to significantly increase serum leptin. An increase of approximately 800 pM increased serum leptin by approximately 70% over 72 h. Changes in plasma glucose concentrations (from approximately 5.0 to approximately 12.6 mM) or changes in plasma FFA concentrations (from < 100 to > 1,000 microM) had no effect on serum leptin. Serum leptin concentrations changed with circadian rhythmicity. The cycle length was approximately 24 h, and the cycle amplitude (peak to trough) was approximately 50%. The circadian leptin cycles and the circadian cycles of total body insulin sensitivity (i.e., GIR, the glucose infusion rates needed to maintain euglycemia during hyperinsulinemic clamping) changed in a mirror image fashion. Moreover, GIR decreased between Days 2 and 3 (from 11.4+/-0.2 to 9. 8+/-0.2 mg/kg min, P< 0.05) when mean 24-h leptin levels reached a peak. In summary, we found (a) that 72 h of hyperinsulinemia increased serum leptin levels dose-dependently; (b) that hyperglycemia or high plasma FFA levels did not affect leptin release; (c) that leptin was released with circadian rhythmicity, and (d) that 24-h leptin cycles correlated inversely with 24-h cycles of insulin sensitivity. We speculate that the close positive correlation between body fat and leptin is mediated, at least in part, by insulin.     

铀的分析方法研究进展

综述了铀的各类放射和化学分析方法的原理、特点和应用范围.放射分析方法主要包括:α能谱法、γ能谱法、中子活化法、裂变径迹法;化学分析法主要包括:容量法/滴定法、分光光度法/比色法、电化学法、荧光光度法、激光荧光法/紫外脉冲荧光法、X射线荧光光谱法(XRF)、电感耦合等离子体发射光谱法(ICP-AES或ICP-OES)、热...     

Comparison by external quality assessment of performance of analytical systems for measurement of therapeutic drugs in serum

OBJECTIVES: To identify the predictors of perceived health and predictors of changes in perceived health in frail hospitalized older persons during the year after hospitalization. DESIGN: Both cross-sectional and longitudinal multivariate analysis of data from a cohort followed for 1 year. SETTING: Six hospital in a group practice model health maintenance organization (HMO) in Southern California. PARTICIPANTS: A total of 1889 persons aged 65 or older who met at least one of 13 inclusionary criteria for a randomized trial of Comprehensive Geriatric Assessment consultation at admission and completed three Functional and Health Status Questionnaires (FHSQ) during a 12-month period. MEASUREMENTS: Functional and health status measures included basic and intermediate activities of daily living (BADL and IADI) and social activities (SA) scales from the Functional Status Questionnaire as well as the mental health index (MHI) and current health perception (CHP), scales from the Medical Outcomes Study short from. Subject's severity of disease was measured by the Resource Demand Scale (RD Scale). RESULTS: In the cross-sectional analyses, MHI score, IADL score, RD Scale, history of falls during the 3 months before hospitalization, and female gender were significant predictors of perceived health in all models for each time point, BADL score, age, presence of incontinence, and ethnicity were significant in the model for baseline only, and SA score was significant in models for 3 months and 12 months only. In the longitudinal analyses, the baseline CHP score and the changes in MHI, IADL, and BADL score predicted CHP change from 0 to 3 months and from 3 to 12 months. CONCLUSIONS: Functional and psychosocial health indicators are the most important and most consistent predictors of perceived health. Our study showed that several predictors of perceived health in cross-sectional analysis did not predict changes in perceived health over a 1-year period. Hence, to fully understand the medical and social contributors to perceived health, a comprehensive approach using both cross-sectional and longitudinal analyses is necessary.     

Comparison of thought-listing rating methods.

Compared 3 methods of rating thoughts: self-ratings, rating by experts with thoughts presented randomly, and rating by experts with thoughts presented in context. 107 university students enrolled in rhetoric classes listed their thoughts prior to giving a speech and completed a personal report of confidence as a speaker. Results indicate that all 3 methods of rating thoughts were equal in predictions of speech anxiety and performance. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Problems of sampling and analytical methods

The need for acceptable, reliable, and practical methods of analysis, chemical, physical, and biological, by the Food Standards Program of the Food and Agriculture Organization/World Health Organization is leading to cooperation by those organizations with the resources and experience to supply them. Methods should be shown to be workable and practicable and then validated in a properly designed international collaborative study for the efficient utilization of the time and effort of participating organizations and laboratories. The methods to be subjected to interlaboratory collaborative study should be clearly written so that the method itself is being tested without unauthorized variations. Satisfactory reference standard materials are often an essential part of the method. Uniform, international methods which have been developed through interlaboratory collaborative studies are applicable to the areas of microbiology and toxicology, as well as chemistry.     

Cystine metabolism in human fibroblasts. Comparison of normal, cystinotic, and gamma-glutamylcysteine synethetase-deficient cells

Incubation of normal human skin fibroblasts or fibroblasts derived from patients with erythrocyte deficiency of gamma-glutamylcysteine synthetase (gamma-glutamylcysteine synthetase-deficient) in culture medium containing L-[35S]cystine resulted in incorporation of radioactivity into protein, cysteine, and glutathione, gamma-Glutamylcysteine synthetase-deficient fibroblasts synthesized glutathione from [35S]cystine at 30% the rate of normal cells and contained 30% the normal amount of glutathione. Cystinotic fibroblasts incorporated [35S]cystine into the large intracellular cystine pool not found in normal or gamma-glutamylcysteine synthetase-deficient cells and also appeared to synthesize glutathione more slowly than normal cells. However, the radioactivity recovered as cystine was reduced greatly and the rate of [35S]cystine incorporation into glutathione increased if cystinotic cells were first depleted of their intracellular cystine pool before incubation in [35S]cystine. This suggests that the apparent reduced rate of glutathione synthesis observed in untreated cystinotic cells was a secondary effect caused by dilution of the [35S]cystine by the large pool of nonradioactive cystine. Cystinotic cells depleted of cystine by treatment with mercaptoethylamine reaccumulate 30 to 50% of their initial cystine in 24 hours in the absence of extracellular cystine. Both normal and cystinotic cells lose more than 90% of their intracellular glutathione in 24 hours in cystine-free medium. Both cell types can reutilize cysteine from glutathione for protein synthesis.     

Polyamine profile in human gastric mucosa infected by Helicobacter pylori

Septicemia is a frequent cause of death in HIV-infected adults in developing countries. Additional prospective studies are needed to determine the etiology of bloodstream infections (BSI) in febrile HIV-infected adults and guide initial evaluation and treatment in this setting. We assessed the prevalence and etiology of community-acquired BSI among 299 consecutive febrile adult medical admissions to Mulago Hospital, Kampala, Uganda, over a 4-month period in 1997. The median age of our patients was 30 years, 159 (53%) were male, and 227 (76%) HIV-1-seropositive. Overall, prevalence of bacteremia or fungemia (1 patient) was 24%. Bacteremia was more frequent in HIV-infected than in uninfected patients (27% versus 15%, respectively; p = .04). Mycobacterium tuberculosis (n = 28), Streptococcus pneumoniae (n = 15) and Salmonella species (n = 13) were the most frequent isolates. All Salmonella and mycobacterial isolates were recovered from HIV-infected patients. Pneumococcal bacteremia was not associated with HIV seropositivity. M. avium complex and M. simiae were isolated from two HIV-infected patients. The rate of mycobacteremia among febrile HIV-infected adults presenting for hospitalization was 13%. Bacteremia and disseminated tuberculosis are frequent causes of morbidity in febrile HIV-infected Ugandan adults. Initial empiric antibiotic coverage in this setting should be targeted toward the pneumococcus and gram-negative enteric bacilli, especially nontyphi Salmonella species. All patients presenting with chronic cough should be evaluated for tuberculosis.