Human blood samples as indicators of occupational exposure to persistent chlorinated hydrocarbons

The value of using human blood as an indicator of occupational exposure to persistent organochlorine compounds is demonstrated. Blood samples from a total of 35 persons divided into three different groups, with and without exposure to chlorinated hydrocarbons in the work atmosphere, have been investigated by gas chromatography using electron capture detection. It is shown that the group of workers with an occupational exposure to pentachlorobenzene, hexachlorobenzene, heptachlorostyrene and octachlorostyrene had a higher level of these chlorinated hydrocarbons in their blood samples than did the other groups. On the average, the concentration of hexachlorobenzene is about 20 times higher in blood samples from the occupationally exposed workers than from the control group. The level of hexachlorobenzene in blood samples of the control groups is low compared to recent studies of blood samples from the general population in other industrialized countries. Furthermore, the average value obtained for the exposed workers is of the same magnitude as the general population in these industrialized countries.     

The feasibility of using cellular phones to collect ecological momentary assessment data: Application to alcohol consumption.

The limitations of paper-and-pencil self-monitoring (PM) are leading to the use of more sophisticated techniques. PM was compared with cellular phone monitoring (CM) to collect ecological momentary assessment data on alcohol use. Twenty social drinkers were randomly assigned to the 2 groups, and their drinking was monitored for 14 days. PM participants recorded data on cards. CM participants carried telephones and responded to an interactive voice response system. The authors found few significant group differences in alcohol use, compliance with the self-monitoring, and satisfaction. However, CM had useful advantages, including instantaneous entry of data into a central database, date and time stamping of data, and easy integration into daily life. Although preliminary, this study suggests that CM is a promising alternative to PM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

Individual bile acids in portal venous and systemic blood serum of fasting man

The serum concentrations of cholic acid (C), chenodeoxycholic acid (CD), and deoxycholic acid (D) were determined in peripheral venous and portal venous blood from 10 otherwise healthy patients undergoing elective cholecystectomy. A highly specific and accurate gas chromatographic-mass spectrometric technique was used. Peripheral venous serum contained 0.49 +/- 0.16 (mean +/- SEM) mumole per liter of C, 1.55 +/- 0.32 mumoles per liter of CD, and 1.44 +/- 0.57 mumoles per liter of D. Arterial serum, obtained from 5 of the subjects, did not show any differences in bile acid concentrations compared to venous serum. In contrast, the portal venous content of each bile acid was several-fold greater, 6.14 +/- 1.20 mumoles per liter of C, 8.40 +/- 1.84 mumoles per liter of CD, and 6.18 +/- 2.27 mumoles per liter of D. The hepatic uptake of C was estimated to be about 90%, whereas that of CD and D was lower, about 70%. This difference in hepatic uptake between the individual bile acids was reflected in the relative composition of the total bile acids, which was 30:39:31 (C:CD:D) in portal venous serum and 13:50:37 in peripheral serum. Compared to common duct bile obtained simultaneously, the portal vein contained a greater proportion of CD. The relevance of the data obtained to our present concept of the enterohepatic circulation of bile acids is discussed, and it is suggested that the higher fasting level of CD compared to C in peripheral serum results from the combination of a lower fractional hepatic extraction and a higher portal venous input to the systemic circulation.     

High-performance liquid chromatographic assay for diltiazem in small-volume blood specimens and application to pharmacokinetic studies in rats

A high-performance liquid chromatographic (HPLC) method was developed which involves the use of two 5-microns BDS silica gel columns (15 cm x 4.6 mm I.D.) in series for increased resolution and sensitivity, and an organic mobile phase for both extraction and elution of diltiazem. Plasma samples (400 microliters) were extracted using the organic mobile phase [n-hexane-methanol-dichloromethane-ammonia (370:35:30:0.3)] and the extracts were monitored at 240 nm. Desipramine (30 micrograms ml-1) was the internal standard. The limit of quantification in plasma was 20 ng ml-1 with a correlation coefficient of > or = 0.999 within the 20-800 ng ml-1 standard window. The inter- and intra-assay R.S.D.s were within 5%. The recovery of diltiazem varied from 101.1% at 20 ng ml-1 to 93.7% at 400 ng ml-1. The method was applied to the investigation of diltiazem absorption in a rat. Drug absorption was based on the intestinal single-pass perfusion model. The concentration of diltiazem in all test perfusion solutions was 1 mg ml-1 (2.4 mM) and the flow-rate through the system was 3.33.10(-3) ml s-1. A non-specific mucolytic absorption enhancer was also added to a diltiazem solution and studied in the in situ system. The pharmacokinetics of diltiazem hydrochloride were investigated in two study groups of Wistar rats (n = 4). A two-sample Student's t-test was employed to compare values of the area under the curve (AUC). The pharmacokinetic data indicated that the AUC in the group which received the enhancer [18.12 +/- 5.43 ng ml-1 h-1 (+/- S.D.)] was higher than that in the control group (11.49 +/- 3.67 ng h-1 ml-1), t-test; p = 0.0483. Hence it was shown that administration of an enhancer could increase the oral bioavailability of diltiazem.     

Estimation of numbers of malaria clones in blood samples

Methods are derived for estimating the mean number of clones of the haploid malaria parasite Plasmodium falciparum from samples of blood of infected hosts which have been tested for the presence of alleles at marker loci. For example, at a locus with three alleles the sample might contain only A1, or A1 and A2, or A1, A2 and A3, with multiple allele classes being more common at high infection rates. Assuming either a Poisson or negative binomial distribution of numbers of infections per host, formulae are derived for the frequency of different classes of blood samples, and maximum likelihood methods are used to estimate the mean number of clones and allele frequencies. Two data sets, each on two loci, are analysed. One data set was from the same locality in Tanzania from which oocysts of the parasite in mosquito vectors were tested for clonality (i.e. diploid unions of gametes from the same clone) using genetic markers. Good agreement was obtained between the observed clonality in oocysts and that expected from the number of infections per host (mean approximately three).     

Evaluation of the quality of life in pediatrics: how to collect the point of view of children

There are very few available child quality of life questionnaires. We describe here a French questionnaire (AUQUEI) which consists of a structured format scale (26 items). The first part of the questionnaire studies child satisfaction. Response levels are measured by checking faces expressing different emotional states. The validation is satisfactory, and the questionnaire is able to differentiate healthy children from sick children (HIV positive). A second part of the questionnaire focuses on the child's own quality of life, and is based upon open-ended questions. This second approach allows to broaden the structured format scale and improves the understanding of the child's quality of life. It constitutes a necessary complement to the first part as it avoids using mechanically adult-specific concepts for children. We also found it to be sensitive enough to distinguish sick children from healthy ones. The AUQUEI questionnaire with its two complementary parts appears to be a potentially valuable tool to better understand the experience of sick children, in the various aspects of their life, and to follow their evolution.     

Comparison of a lysed whole blood method to purified cell preparations for lymphocyte immunophenotyping: differences between healthy controls and HIV-positive specimens

Although the majority of clinical laboratories now use a lysed whole blood (LWB) method for routine immunophenotyping, researchers wishing to perform other types of studies with lymphocytes from HIV+ patients may still need to use purified cell preparations, such as peripheral blood mononuclear cells (PBMC). A comparison study of the two methods was performed, using peripheral blood specimens from normal donors and from patients infected with the human immunodeficiency virus (HIV+). Reproducibility studies and several types of holding studies (both before and after specimen processing) were also performed. The results suggest that the two different methods of sample preparation have different effects upon abnormal patient specimens than those observed in healthy controls. Immunophenotyping results derived from the two different methods cannot be considered equivalent for the purposes of quantitating the presence of a particular type of cell.     

The generation of fibrinopeptide A in clinical blood samples: evidence for thrombin activity

Plasma fibrinopeptide A (FPA) concentrations were measured in clinical blood samples incubated in the collecting syringe for different time periods before addition to heparin and Trasylol, and the rate of in vitro generation of FPA was calculated as the mean increment in FPA concentration per minute over the linear portion of the generation curve. 36 normal individuals had a mean plasma FPA level of 0.64 +/- 0.56 pmol/ml and an FPA generation rate of less than 0.5 pmol/ml per min. Clinical samples with elevated plasma FPA levels manifested slow (less than 1 pmol/ml per min) (28 patients) or rapid FPA generation (greater than 1 pmol/ml per min) (33 patients). Slow FPA generation was found in 10/10 patients with venous thrombosis, in 4/4 with aortic aneurysm, and in several patients with acquired hypofibrinogenemia. In one such patient, addition of fibrinogen resulted in rapid FPA generation whereas thrombin addition was without effect. Rapid FPA generation was generally linear, was usually associated with slower fibrinopeptide B generation and was inhibited by parenteral or in vitro heparin. It is thought to reflect increased thrombin activity and was seen in patients with pulmonary embolism, active systemic lupus erythematosus, renal transplant rejection, and after infusion of prothrombin concentrates. The initial rate of FPA cleavage by thrombin at fibrinogen concentrations from 0.05 to 4 mg/ml showed little change between 2 and 4 mg/ml with a Km of 2.99 muM. At a fibrinogen concentration of 2.5 mg/ml the FPA cleavage rate was 49.2 +/- 1.6 nmol/ml per min per U of thrombin. Exogenous thrombin added to normal blood generated 21.7 nmol/ml per U of thrombin FPA in the first minute with a nonlinear pattern reflecting inactivation of thrombin and the presence of alternative substrates. Hence, the thrombin concentration in the blood cannot be calculated from the FPA generation rate. The FPA generation rates in clinical samples with rapid generation (1-28 pmol/ml per min) could be produced by 2 X 10(-5) to 5.6 X 10(-4) thrombin U/ml acting on purified fibrinogen at physiological conditions of pH, ionic strength, and temperature.     

When not to comment.

Suggests that errors, such as the one S. D. McLaughlin (1980) made in his critique of M. H. Birnbaum's (1979) article on sex bias in salaries of psychologists, could be avoided if authors would read material cited as containing theory before rushing into print with claims that procedures are atheoretical. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of fasting on mucosal blood flow in antrum and corpus of the stomach

Gastric mucosal blood flow in the rat was determined by the indicator fractionation technique 86RbCl. Antral and corpus flow rates were determined after increasing periods of fasting, and the effect of vagotomy was assessed. The physiological stimulus of food in the stomach markedly increased antral as well as corpus blood flow, and after vagotomy lower flow rates were recorded in all parts of the stomach. With progressive starvation, the antral:corpus flow ratio decreased. The findings suggest that the antrum plays an active role in response to a physiological stimulus and may, as has been suggested by others, contribute to the control of parietal cell blood flow and secretion.     

Hyperinsulinism in infancy: diagnosis by demonstration of abnormal response to fasting hypoglycemia

The metabolic adaptation to fasting in infants with hyperinsulinism was examined to see whether a characteristic abnormality could be found that would aid in the diagnosis of this disorder. Seven infants under 1 year of age with hyperinsulinism were studied; 7 control infants of similar age and 12 children with ketotic hypoglycemia served as contrast groups. At the time of hypoglycemia, four of the seven infants with hyperinsulinism did not have elevated levels of insulin. However, levels of beta-hydroxybutyrate were significantly lower in the infants with hyperinsulinism than in the control and ketotic hypoglycemic groups. Levels of free fatty acids were also lower in the infants with hyperinsulinism. Expected levels and normal limits for beta-hydroxybutyrate, insulin, and free fatty acids when plasma glucose is below 40 mg/100 ml were estimated by combining the control and ketotic hypoglycemic groups. Using these values as standards, the diagnosis of hyperinsulinism can be made by evaluation of the response to fasting hypoglycemia. The application of this approach is illustrated by three case examples.     

Accuracy of an automated blood pressure device in stable inpatients: optimum vs routine use

OBJECTIVES: The review lists the child psychiatry day-care centres in Quebec, evaluates their capacity, and describes them according to the age range for admission, the psychopathologies treated, and the parent involvement required. METHOD: The 26 programs selected, which are all associated with a hospital centre, assess and treat children aged 0 to 12 years on a day-care basis. Organization, clinical operation, and research are addressed during a semisupervised interview. RESULTS: The average capacity is 18 children (4 to 40), with a total capacity of 454 children. The number of preschool patients can be compared with the number of school patients. Few programs are dedicated to invasive development disorders, and one-third treat behavioural or emotional disorders. The larger capacity programs treat patients of both genders. Most programs are eclectic and encourage but do not require parental involvement. CONCLUSIONS: Results take into account different theoretical influences, the controversy about integration criteria and parent involvement, and the specificity of the child psychiatry mission.     

Anatomical variation of cerebral venous drainage: the theoretical effect on jugular bulb blood samples

A workshop was convened to discuss safety issues for traditional-approach HIV vaccines, especially inactivated vaccines. The topics included issues pertaining to (1) cell substrates used for production and (2) vaccine virus inactivation. The use of cell substrates such as tumor-derived continuous cell lines (TCLs) or virus-transformed. CLs may be the most feasible approach to provide commercial-scale virus yields. However, especially because of concerns about tumorigenicity, TCLs have not been used to produce preventive vaccines for human trials with healthy subjects in the United States. Residual TCL material (e.g., DNA, cellular proteins, viruses) may not be removed during purification of intact HIV virions to the same extent achievable for a recombinant protein. Manufacturing processes, e.g., physicochemical methods of destroying DNA, could decrease tumorigenicity risk. Methods to assess potential for tumorigenicity may need further development. Another potential substrate for viral production that merits further study is human peripheral blood mononuclear cells (PBMCs). Regardless of the cell substrate used, extensive testing for adventitious agents (including non-HIV retroviruses) is needed. Vaccine virus inactivation can be considered in statistical terms, i.e., the probability of a surviving infectious particle. One formula to determine a "safety margin" (SM) is reduction of titer in log10 for all inactivation steps minus initial viral infectivity in log10. Calculations for appropriate SMs should include all sources of variability (e.g., lot-to-lot differences). Ensuring a specified SM, as the lower bound of the 95% confidence interval, for production lots was discussed. Sensitivity and specificity of infectivity assays may present limitations.     

Comparison of culture and the antigenemia assay for detection of cytomegalovirus in blood specimens submitted to a reference laboratory

We compared the antigenemia assay (AA) with tandem shell vial cultures (SVCs) and tube cultures (TCs) for detection of cytomegalovirus (CMV) in 343 blood specimens. For 249 specimens, the AA was performed in duplicate with two different commercially available monoclonal antibody reagents (Biotest Diagnostic Corporation and Argene Biosoft). Specimens considered true positives were positive in either culture system or both AAs. Only specimens which were negative in both cultures and positive in a single AA were tested retrospectively with a CMV PCR assay. CMV recovery rates were also calculated to determine if increased specimen age resulted in decreased positivity. CMV recovery rates for the AA and the combination of both cultures were 20.0 and 5.0% at 3 to 18 h, 20.2 and 14.0% at 18 to 35 h, 12.5 and 7.8% at 36 to 52 h, and 18.8 and 6.3% at 64 to 75 h, respectively. The sensitivities and specificities of the Biotest AA, the Argene AA, SVC, and TC were 84.4 and 100.0, 100.0 and 99.6, 44.4 and 100.0, and 46.0 and 100.0%, respectively. The AA was significantly more sensitive than either culture method alone and was also more sensitive than the two culture methods used in tandem (the tandem culture sensitivity was 63.5%); the Argene AA identified more positives than the Biotest AA.