Consistent magnetic-field induced dynamical changes in rabbit brain activity detected by recurrence quantification analysis

The reports dealing with the effects of electromagnetic fields (EMFs) on brain electrical activity have been inconsistent. We suspected that the use of linear methods and models accounted for some of the variability, and we explored the issue by using a novel approach to study the effects of EMFs on the electroencephalogram (EEG) from rabbits. The EEG was embedded in phase space and local recurrence plots were calculated and quantified to permit comparisons between exposed and control epochs from individual animals. Statistically significant alterations in brain activity were observed in each animal (n=10) when it was exposed to 2.5 G, 60 Hz, as assessed using each of two recurrence-plot quantifiers. Each result was replicated; a positive-control procedure ruled out the possibility that the effect of the field was a product of the method of analysis. Measurements performed while the rabbits were under anesthesia suggested that the effect was mediated by N-methyl-D-aspartate and/or alpha(2)-adrenoceptors. No differences were found between exposed and control epochs in any animal when the experiment was repeated after the rabbits had been killed, indicating that a putative interaction between the field and the EEG electrodes could not account for the observed effects. We conclude that EMF transduction resulting in changes in brain electrical activity could be demonstrated consistently using a nonlinear method of analysis.     

Umbilical cord plasma leptin is increased in preeclampsia

OBJECTIVE: The objective of this study was to compare umbilical cord plasma leptin between infants of mothers who experienced preeclampsia and infants of control subjects and to study the relation between cord plasma leptin and infant obesity, as indicated by ponderal index. STUDY DESIGN: On the basis of a population of approximately 13,000 deliveries, we compared cord plasma leptin from preeclamptic (n = 256 women) and control pregnancies (n = 607 women) after taking the differences in gestational age and ponderal index into account. RESULTS: Cord plasma leptin increased strongly with gestational age, both in the preeclampsia group and the control subjects (P <.01), but at each gestational age the preeclampsia group had higher leptin levels than control subjects (P <.01). Adjustment for the higher ponderal index among control subjects (P <.05) did not alter the difference in leptin levels between the groups. CONCLUSION: We found higher levels of umbilical cord plasma leptin in infants of mothers who had preeclampsia (compared with infants of control subjects) after adjusting for differences in gestational age, gender, and infant ponderal index.     

Allometric Species Comparison of Toluene and n–Hexane Metabolism: Prediction of Hepatic Clearance in Man from Experiments with Rodent Liver S9 in a Head Space Vial Equilibration System

Abstract: The liver S9 head space vial equilibration technique is an in vitro alternative that holds promises for a satisfactory in vivo extrapolation of liver metabolism of volatile organic chemicals. The aim of this study was to investigate the suitability of this methodology for the extrapolation of in vitro metabolic data from rodent to man by allometry with the two highly metabolized organic solvents toluene and n–hexane as model substances. The calculated hepatic clearance of toluene in man from rodent liver S9 in this study was equal to the reported total body clearance of toluene in man, suggesting insignificant extrahepatic clearance of toluene in humans. The calculated hepatic clearance of n–hexane was less than the reported values of total body clearance of n–hexane in man, indicating an about 80% extrahepatic clearance of n–hexane in humans. Both results are in line with our present knowledge of the metabolism of the two organic solvents in man. Allometric scaling from rodent liver S9 head space incubations to in vivo metabolism of toluene and n–hexane in man thus seems promising and could be a method of choice for scaling of organic solvent metabolism in general.     

The binding of thio-TEPA in human serum and to isolated serum protein fractions

Summary Binding of triethylenethiophosphoramide (thio-TEPA) in serum from healthy individuals and from cancer patients and its binding to isolated serum protein fractions were studied by equilibrium dialysis. A drug-protein binding in the order of 10% was demonstrated in serum, with little interindividual variation. The protein binding of thio-TEPA seemed to be restricted to albumin and lipoproteins, with the greatest affinity to albumin. The previously reported selective binding of thio-TEPA to gamma globulin was contrary to our findings. The almost insignificant degree of serum protein binding of thio-TEPA indicates that the drug is well suited for use in cancer drug combinations.The work described in this paper was supported by grants from The Norwegian Cancer Society (Oslo), the Regional Hospital (Trondheim), and Trondheim Cancer Society (Trondheim)During the work Bjørn Hagen was a research fellow in The Norwegian Cancer Society     

Papillomavirus infection among abortion applicants and patients at a sexually transmitted disease clinic.

The base-line prevalence of human papillomavirus (HPV) infection among applicants for first trimester induced abortion and among a sexually transmitted disease (STD) clinic population with macroscopically visible condyloma is investigated. Cervical cells were collected from 505 women applying for induced abortion. Cell scrapes were obtained from the surface of the warts from 81 female and 32 male STD patients. HPV DNA 6/11, 16/18, and 31/33/35 were detected by a dot blot technique (ViraPap and ViraType, Life Technologies, Gaithersburg, MD). Of the 505 abortion applicants, 31 (6.1%) had HPV DNA. In the STD population, 64 (79.0%) patients had positive test results for HPV DNA from cervical, introital cell scrapes, or both. Of the 32 male STD patients from whom preputial, urethral samples, or both were taken, 24 (75%) had HPV DNA. After typing, the relative proportion of HPV 6/11 was 9.7% in abortion applicants, 72.2% in female STD patients, and 91.3% in male STD patients. The relative proportion of high-risk HPV types, such as 16/18 and 31/33/35, was 89.7% among abortion applicants, 38.9% among female STD patients and 13.0% among male STD patients. The majority of abortion applicants infected with HPV were thus infected with a potentially oncogenic HPV type, and the prevalence of HPV type 16/18 and 31/33/35 was also high among female STD patients.     

Identification and characterization of important allergens from mugwort pollen by IEF, SDS-PAGE and immunoblotting

Mugwort (Artemisia vulgaris L.) pollen allergens, separated by SDS-PAGE or IEF, were identified after transfer to NCM by incubation with a panel of sera from 16 patients with clinical mugwort pollen allergy, followed by [125I]anti-IgE and autoradiography. Of the at least 23 components separated by SDS-PAGE in a 15% polyacrylamide gel, at least 15 components with mol. wts 12,000-100,000 bound IgE from the panel of patient sera. A component of mol. wt 22,000 bound IgE from at least 94% of the patient sera tested and for all but three sera this component also bound the greatest quantity of IgE. Five other components with mol. wts 12,000, 17,000, 29,000, 39,000 and 42,000 bound IgE from 75-94% of the patient sera. After separation by IEF, at least 28 protein bands were detected in the pI region 3.5-7.2 and at least seven bands were found in the region 8.6-9.3. At least 11 bands in the pI range 4.2-7.3 and at least five bands in the pI region 8.5-9.2 bound IgE from the panel of patient sera. The most intense radiostaining was observed with a component having a pI of 4.35, which bound IgE from 31% of the patient sera. Immunoblotting of the SDS-PAGE and IEF gels using specific rabbit antisera and human sera against three important mugwort pollen allergens, denoted Ag 9, Ag 12 and Ag 13, was performed to determine the mol. wt and pI of these allergens which had earlier only been identified in CIE/CRIE. The results revealed that Ag 13 had a mol. wt of 61,000 and a pI of 4.35, Ag 12 had a mol. wt of 22,000 and AG 9 had pIs in the region 4.55-5.55 (six isoforms). Ag 9 did not bind IgE after SDS-PAGE and was thus not identified in the SDS-PAGE pattern, and Ag 12 failed to be detected in the NCM after transfer from IEF gels. By crossed immunoelectrofocusing, Ag 12 was found to consist of several isoforms predominantly located in the pI region 3.5-5.1. The immunoblotting analysis also revealed that the glycoprotein allergen Art v II was not detected after transfer from either SDS-PAGE or IEF gels. In conclusion, immunoblotting analysis of SDS-PAGE and IEF gels are useful methods for characterization of mugwort pollen extract, but it should be noted that some important allergens which are easily identified in CIE/CRIE may fail to be detected by these methods.     

Inhalation Kinetics of C6 to C10 Aliphatic,Aromatic and Naphthenic Hydrocarbons in Rat after Repeated Exposures

Abstract: The toxicokinetic properties of C6 to C10 n-alkanes, aromates and naphthenes have been investigated in rats during inhalation of 100 p.p.m. of the single hydrocarbons for 3 days, 12 hr/day. The concentration of hydrocarbon was measured by head space gas chromatography in blood, brain, liver, kidneys and perirenal fat at days 1, 2 and 3, immediately after termination of exposure and 12 hr after exposure on day 3. The main conclusions drawn from the study were: a) Aromatic hydrocarbons show high concentrations in blood and low concentrations in organs. b) Naphthenic hydrocarbons show low concentrations in blood and high concentrations in organs. c) n-Alkanes show very low concentrations in blood, relatively high concentrations in brain and a high potential for accumulation in fat with repeated exposures. d) Biological concentrations of hydrocarbons within one class increase in general with increasing molecular weight, though with specific exceptions. e) Accumulation is obviously influenced by differences in metabolism and enzyme induction potential. f) Lipid solubility is not the only parameter relevant for the evaluation of hydrocarbon accumulation.     

Comparison of parasitological and immunological methods in the diagnosis of leishmaniasis in Ethiopia.

The sensitivity and specificity of parasite demonstration methods (smear, culture and histology) and serological assays (enzyme-linked immunosorbent assay [ELISA], direct agglutination test and immunoblot) were compared in the diagnosis of leishmaniasis in Ethiopia. Culture was found to be the most sensitive diagnostic method, followed by ELISA, for the diagnosis of cutaneous leishmaniasis (CL). When the clinical type of CL was taken into consideration, serological and parasitological methods were equally good for the diagnosis of diffuse cutaneous leishmaniasis. Overall, the serological assays were not sensitive enough to diagnose all the parasitologically confirmed cases of localized cutaneous leishmaniasis. Both groups of diagnostic methods performed equally well in the diagnosis of visceral leishmaniasis patients. In cases of CL where clinical diagnosis was a problem and histology could not give a definitive diagnosis due to the absence of demonstrable parasites, one of the serological assays, preferably ELISA, was very useful in establishing the final diagnosis.