A Direct Comparison of the Skin Conductance and Skin Resistance Methods

The purpose of the present study was a direct comparison between simultaneous recordings of skin conductance and skin resistance. Sixty male students received a series of 30 white noise stimuli, while measures were taken continuously from four sites on the palmar surfaces of the fingers. Evaluations were made for response amplitudes, recovery, and for an approximate area measure. Magnitude of reactions and reliabilities were compared using ANOVA procedures. Behavioral concordances were estimated as correlations with the subjects' ratings of stimulus intensities. Conductance and resistance measures do not differ in amplitude, in area, or in strength of their reliabilities and behavioral concordances. No differences in any respect are found between sites. Skin conductance yields significantly (p < .01) shorter recovery times than skin resistance, which is discussed in terms of membrane permeability change.     

An algorithm for mapping the catheter tip position on a fluorograph to the three-dimensional position in magnetic resonance angiography volume data

This paper proposes an algorithm which maps the position of a catheter tip on a fluorograph to the 3D position in magnetic resonance angiography (MRA) data. This algorithm was assessed for its accuracy. We designed an algorithm consisting of a registration step and a recognition step. The registration step registers MRA and fluorography data using a digital subtraction angiography (DSA) image. The recognition step recognizes the position in the MRA data corresponding to the catheter tip position on a fluorograph. We checked the accuracy of the recognition step by employing an artificial data set consisting of 3D image data (64 x 64 x 64 matrix) and its projection image (92 x 92 matrix) and the accuracy of the registration step with the aid of three of the 3D time-of-flight MRA data sets (256 x 256 matrix and 60 slices) and their projection images in the form of DSA images. The accuracy of the recognition step depended upon that of the registration. When there was no misregistration, all of the mean errors were less than 0.2 mm. The mean errors of the registration step were 0.273 mm and 0.226 mm, respectively, for the longitudinal shift along the X and Y axes, 0.478 degrees, 1.203 degrees and 0.208 degrees, respectively, for the rotation angles around the X, Y and Z axes and 0.020 times for the magnification. The mean image error between the projection image of the registered MRA data and that of the MRA data which were employed as the DSA image was 0.034 mm.     

Generation of antibodies directed against the low-immunogenic peptide-toxins microcystin-LR/RR and nodularin

The preparation of antibodies against the liver toxin microcystin, as described here, is of major importance for its detection and purification in food and water, and for a therapeutic approach to neutralize the toxin by passive immunization. Microcystin-LR (MLR) and microcystin-RR (MRR) were purified from cyanobacterial cell materials by extraction, Sephadex LH-20-, ODS silica gel-, ionic exchange and RP-HPLC-chromatography. In order to reduce the toxicity for parenteral administration, microcystins were coupled by the carbodiimide method to poly-L-lysine (PLL(50.000)). Mice and rabbits were immunized with the conjugates in the presence of two lipopeptide immunoadjuvants (P(3)CSK(4) and P(3)CS-T(h)). High MLR-specific antibody levels were observed after parenteral coadministration of antigen and lipopeptides, whereas no anti-MLR antibodies were obtained with free microcystin or the microcystin-PLL(50.000)-conjugate in the absence of lipopeptide. In oral immunization, coadministration of antigen and adjuvants resulted in an accelerated development of anti MLR-specific antibodies and high antibody levels. Using the antisera, we could detect different microcystins and nodularin down to a concentration range of 10-50 ng/ml by a competitive inhibition ELISA; detection of microcystins in crude cell preparations was also possible. Furthermore, microcystins from different sources could be detected and discriminated from cyclic cyanopeptolines.     

Behavioral Characterization of Alcohol-Tolerant and Alcohol-Nontolerant Rat Lines and an F2 Generation

The Alcohol Tolerant (AT) and Alcohol Nontolerant (ANT) rats, selectively bred for ethanol-induced ataxia on the inclined plane at ALKO in Finland, were moved to the University of Colorado in 1998. The selection phenotype was tested on generation 60 animals in Colorado. In week one, ataxia was measured on the inclined plane 30 minutes after an intraperitoneal dose of 2 g/kg 15% w/v ethanol. Differences in ethanol-induced ataxia between the AT and ANT lines at the University of Colorado were similar to those in the original lines in Finland. In week two, ataxia was measured on the inclined plane at 5 and 30 minutes, and tolerance was measured as the time to regain the original angle of sliding. The AT rats rapidly developed tolerance to 2 g/kg ethanol on the inclined plane; tolerance development was significantly slower in the ANT rats. In week three, the animals were tested for the duration of loss of righting reflex (LORR) and blood ethanol concentration at regain of the righting reflex (BEC_RRR) following a dose of 3.5 g/kg. The AT rats had a significantly higher BEC_RRR than did the ANT rats, but did not differ in LORR. A separate experiment with previously untreated rats demonstrated that naïve animals of the two lines did not differ in BEC_RRR or LORR. AT and ANT rats were genotyped for the mutation that occurs in the gene for the α6 subunit of the GABA_A receptor, a natural mutation that is known to affect benzodiazepine responses. All ANT animals tested carried the mutant allele, whereas some AT families carried the mutation and others were wild type. There was no effect of the mutation in AT rats for any of the phenotypes that were tested. After several generations of brother–sister mating, the AT and ANT lines were more than 90% inbred as determined by genotyping. One AT (wild-type) line and one ANT (mutant) line were selected for breeding an F₂ intercross generation of 1200 animals. They were phenotyped for sensitivity and tolerance to ethanol on each of three consecutive weeks. Order of testing had a modest effect on some of the phenotypes: when tested during the third week as compared to weeks one or two, BEC_RRR was increased, 30-minute sensitivity was increased, and development of acute tolerance was increased. Statistically significant correlations were found between tolerance and sensitivity at both 5 and 30 minutes, and between LORR and BEC_RRR. The smaller (or absence of) significant correlations between others of the phenotypes indicate(s) that they are most likely controlled by different sets of genes.     

Rapid genotyping of MBL2 gene mutations using real-time PCR with fluorescent hybridisation probes

In this study, we describe a real-time polymerase chain reaction (PCR) for genotyping all known polymorphisms of the human mannose-binding lectin 2 (MBL2) gene. These comprised two variations in the 5' regulatory region at positions -550 (H/L) and -221 (X/Y), one in the 5' untranslated sequence at position +4 (P/Q) and three structural mutations within exon 1 at codons 52, 54, and 57, also known as the D, B and C variants, respectively. Three reactions with two different conditions were sufficient to genotype one individual unambiguously. The three mutations in exon 1 were detected in one capillary using a sensor probe covering the three mutations, whereas amplification of the variants located upstream of the coding sequence was performed in only two reactions. Single colour detection was used for detection of the (H/L) polymorphism and multiplexing by dual colour probes was used for simultaneous genotyping of (X/Y) and (P/Q). The reliability of the system was evaluated by comparison with a conventional PCR method with sequence-specific primers (PCR-SSP). For this study, 100 individuals of Danish and 30 of African descent were analysed, and the genotypes obtained were concordant in all cases. This new method is rapid and provides reliable results without ambiguities.     

Loading of polystyrene solid phases with microbial agents and their polysaccharide antigens for the screening of monoclonal antibodies

Before screening monoclonal antibodies using enzyme immuno assays, it is necessary to prove that the coating of the solid phases occurs efficiently. The adhesion of whole cells of group B streptococci, Escherichia coli K1, Haemophilus influenzae type b and Candida albicans as well as B-Streptococcus group antigen, H. influenzae type b capsular antigen, and C. albicans cell wall antigen to polystyrene solid phases was studied and detected by the following methods: Peroxidase competition procedure, scintillation measurement of 32phosphate-labelled germs, and reactions with monoclonal antibodies.     

Incidence and diagnosis of acute rheumatic fever in Denmark, 1980 and 1983. A retrospective analysis of the fulfillment of the revised Jones criteria in hospitalized patients

A review of 1547 official hospital record summaries concerning discharges during the period 1980 through 1983 of patients whose diagnoses had been coded as acute rheumatic fever revealed that in only 61% of the cases had this illness been diagnosed or suspected. A substantial proportion of the remaining patients had had acute non-rheumatic pericarditis diagnosed. The medical records were analyzed for 141 patients diagnosed in 1980 or 1983 by hospital departments as having acute rheumatic fever with regard to the revised Jones criteria. They were fulfilled in 47 patients, 23 of whom were considered unlikely cases of rheumatic fever. Eight patients were considered possible cases, although they did not fulfill the revised Jones criteria. The current annual incidence of acute rheumatic fever was estimated to be at most 0.3 per 100,000 inhabitants.     

Short note: oral contraceptives and sleep in depressed and healthy women

STUDY OBJECTIVES: To evaluate the effects of oral contraceptives (OCs) on sleep EEG in healthy women and in those with major depressive disorders (MDD). DESIGN: This archival study selected participants who had sleep EEG measured over two consecutive nights, following a five-day regularized sleep-wake routine. Between-groups multivariate analysis of variance (MANOVA) contrasted group and OC main effects and interactions on sleep architecture. SETTING: N/A PARTICIPANTS: Sixty-eight women (ages 14-46 years) diagnosed with major depressive disorder (MDD), 13 of whom were on OCs and 55 were not. Patients were symptomatic and untreated at the time of study. Thirty-seven healthy control women (ages 12-46 years), nine of whom were on OCs and 28 were not. INTERVENTIONS: N/A Measurements and Results: OC main effects were found for %SW and for REM latency. Significant OC x Group interactions were found for sleep latency and %REM. Sleep latency was significantly shorter on OCs, but only in healthy women. Women on OCs showed a shorter REM latency, more total REM time, and less slow-wave sleep than women who were not on OCs. CONCLUSIONS: The effects of OCs were generally larger in healthy women than in those with MDD. Moreover, OC use was associated with more disturbed sleep in healthy women. These findings imply that OC use may compromise sleep EEG differences between healthy and depressed women and may be more difficult to differentiate between depressed patients and healthy controls when sleep studies include women on OCs. These findings may also have implications for evaluating gender differences in sleep architecture.     

Neurotrophic effects of hippocampal target cells on developing septal cholinergic neurons in culture

The influence of hippocampal target cells on the development of cholinergic septal neurons was studied in rotation-mediated reaggregating cell cultures. Brain cells from 15-day-old mouse embryos were obtained from: septum, containing cholinergic cells which project to the hippocampus; hippocampus which contains target cells for the septal cholinergic neurons; and cerebellum, containing cells which are not targets for the septal cholinergic cells. The cells were then cultured for 3 weeks in a rotary incubator in the following combinations: septal cells alone; hippocampal cells alone; cerebellar cells alone; septal-hippocampal cells together; and septal-cerebellar cells together. After harvesting, fixation, and embedding, 50 micron sections were cut and processed for visualization of acetylcholinesterase activity. Sections from reaggregates containing either hippocampal or cerebellar cells alone contained only a few acetylcholinesterase-positive cells, but no positive fibers. Sections from septal-hippocampal coaggregates revealed a pattern of well-defined, fine-caliber acetylcholinesterase-positive fibers with extensive arborizations and varicosities suggesting axonal proliferation. In septal-cerebellar coaggregates, acetylcholinesterase-positive fibers appeared to be degenerating and distinct areas were observed which were essentially devoid of acetylcholinesterase fibers. In some experiments, either cerebellar or hippocampal cells were labeled with wheatgerm agglutinin-rhodamine prior to culture in order to identify these cells in the resulting reaggregates. Analysis of sections from these studies showed that acetylcholinesterase fibers were excluded from regions of coaggregates containing cerebellar cells, but were present in regions of coaggregates containing hippocampal cells. Finally, cell counts of acetylcholinesterase-positive cells in the various combinations revealed that these putative cholinergic neurons were significantly more numerous in septal-hippocampal coaggregates (271 +/- 19 per 10(6) septal cells added) than in septal reaggregates (38 +/- 6 per 10(6) septal cells added) or septal-cerebellar coaggregates (85 +/- 29 per 10(6) septal cells added). These results, taken together, suggest that hippocampal target cells influence the development and survival of cholinergic neurons.