Association between platelet endothelial cellular adhesion molecule 1 (PECAM-1/CD31) polymorphisms and acute myocardial infarction: a study in patients from Sicily.

Adhesion of circulating cells to the arterial surface is among the first detectable events in atherogenesis. Cellular adhesion molecules, expressed by the vascular endothelium and by circulating leucocytes, mediate cell recruitment and their transendothelial migration. Platelet endothelial cellular adhesion molecule 1 (PECAM-1/CD31), involved in this migration, has been associated with the developmental course of atherosclerosis. A few studies have investigated an association between coronary heart disease and single nucleotide polymorphisms (SNPs) located in functionally important domains of the PECAM-1/CD31 gene. In particular, Ser563Asn and Gly670Arg SNPs have been described as susceptibility factors involved in acute myocardial infarction (AMI) in the Japanese male population. To confirm these observations, we studied 96 male patients (mean age 40 years; age range 20-46) affected by AMI and 118 healthy male controls (mean age 38 years, age range: 20-55), and analysed for the following PECAM-1/CD31 SNPs: Val125Leu, Asn563Ser and Gly670Arg. The frequency of the Gly670Arg polymorphism was significantly higher in patients with AMI (58.9% vs. 48.3%; P = 0.019), whereas the frequencies of the other two SNPs (Leu125Val and Ser563Asn) were not significantly different between patients and controls. By comparing the observed number of 670Arg/Arg genotypes in the patients with the expected number, calculated from the allele frequency in a healthy population, a significance of P = 0.02 (odds ratio, 2.04; 95% CI: 1.1-3.7) was obtained, supporting a recessive model of inheritance. Hence, the differences between patients and controls are significant, but relatively small. However, as AMI is a multifactorial disease, any single mutation will only provide a small or modest contribution to the risk, which also depends on environmental interaction. All in all, we believe that the results of the present study would add support to the role of pro/anti-inflammatory genotypes in determining susceptibility or resistance to immune-inflammatory diseases, including atherosclerosis.     

Pretectal jerk neuron activity during saccadic eye movements and visual stimulations in the cat

Summary The activity of jerk neurons was recorded extracellularly in the pretectum of the awake cat. The characteristic response of jerk neurons was a short, high-frequency burst that occurred after fast movements (jerks) of a large, structured visual stimulus, during saccadic eye movements in the light, and after on or off visual stimulation. Mean burst latency to pure visual jerks was 50 ms, whereas it was 30 ms to saccadic eye movements. Bursts were found to be stereotyped; the highest discharge rate was always at burst onset. Jerk neurons were not selective for stimulus parameters (such as movement amplitude or direction) except that in some neurons a weak correlation between stimulus velocity and discharge frequency was found. During saccades in the dark, clear bursts were only rarely found. In about half of the neurons, however, there was a slight but significant increase in the number of spikes above spontaneous frequency. Visual receptive fields were very large (46° horizontal and 35° vertical extent, on average). Nevertheless, the pretectal jerk neurons showed a rough retinotopic order, which was in accordance with the published retinotopy of the pretectum. Jerk neurons were found throughout the whole superficial pretectum, but preferentially in an area that corresponds to the nucleus of the optic tract (NOT) and the nucleus pretectalis posterior (NPP). Saccades were elicited by electrical stimulations at the sites where jerk neurons were recorded. The direction of the elicited saccades depended strongly on the pretectal stimulation site. A possible role of the jerk neurons as a visuomotor relay to elicit saccades or to modulate perception and attention is discussed.     

Decreased aminoacylation of mutant tRNAs in MELAS but not in MERRF patients

Mutations in human mitochondrial tRNA genes are associated witha number of multisystemic disorders. Using an assay that combinestRNA oxidation and circularization we have determined the relativeamounts and states of aminoacylation of mutant and wild-typetRNAs in tissue samples from patients with MELAS syndrome (mito-chondrial myopathy, encephalopathy, lactic acidosis, stroke-likeepisodes) and MERRF syndrome (myoclonus epilepsy with raggedred fibers), respectively. In most, but not all, biopsies fromMELAS patients carrying the A3243G substitution in the mitochondrialtRNA^Leu(UUR) gene, the mutant tRNA is under-represented amongprocessed and/or aminoacylated tRNAs. In contrast, in biopsiesfrom MERRF patients harboring the A8344G substitution in thetRNA^Lys gene neither the relative abundance nor the aminoacylationof the mutated tRNA is affected. Thus, whereas the A3243G mutationmay contribute to the pathogenesis of MELAS by reducing theamount of aminoacylated tRNA^Leu, the A8344G mutation does notaffect tRNA^Lys function in the same way. ⁺ To whom correspondence should be addressed. Tel: +1 617 4954396; Fax: +1 617 495 0758; Email: boerner@fas.harvard.edu     

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.