Spectrometric studies on stability of tenuazonic acid (TeA) solution in organic solvents

The stability of tenuazonic acid solution at different temperatures and storage times was studied using methanol, methanol-water (8:2 v/v), benzene and benzene-acetonitrile (98:2 v/v) as solvents. Solutions were analysed by a spectrometric method TeA U.V.-spectrum was recorded. Results indicated that the optimum temperature for long-time storage period of tenuazonic acid solution in any solvent assayed is -20°C. Benzene and benzene-acetonitrile (98:2 v/v) could be advised to make tenuazonic acid solution which will be stored less than 2 months at 4°C. Methanol and methanolwater (8:2 v/v) are not recommended because a low stability of TeA solution in this solvents.     

Serological evidence of an antibody response in farmed southern bluefin tuna naturally infected with the blood fluke Cardicola forsteri

In this study, adaptive immune response was investigated in farmed southern bluefin tuna, Thunnus maccoyii, infected with a sanguinicolid Cardicola forsteri. A cohort (Cohort₂₀₀₅) of southern bluefin tuna was sampled between March 2005 and August 2006. Samples were taken at the transfer of wild caught tuna to sea cages and then at regular intervals. Parasite intensity, abundance and prevalence data were recorded. An ELISA was developed to detect and quantify an antibody response against the blood fluke in southern bluefin tuna serum. Intensity and prevalence of the blood fluke were shown to peak in May 2005 at 10.9 flukes per infected fish (SE = 1.72) and 97.5% prevalence and then decreased to low prevalence (10%) and intensity (1.0). There were no significant changes in prevalence or intensity in 2006. Antibody titres and seroprevalence increased from 1.37 U μl⁻¹ and 10% at transfer in March 2005 to reach a peak in December 2005 of 25.86 U μl⁻¹ (SE = 6.26 U μl⁻¹) and 66.66%. No significant changes were observed in antibody titres for the same cohort of fish during 2006. Parasitological and serological values from Cohort₂₀₀₅ were compared to a 2006 cohort (Cohort₂₀₀₆) in March 2006 and August 2006 to determine if prior infection in Cohort₂₀₀₅ elicited any protection against infection in 2006. Although significant differences were not observed in intensities between cohorts it was shown that Cohort₂₀₀₅ had significantly lower abundances and prevalences of blood fluke infection than Cohort₂₀₀₆. Although there was no significant difference in mean antibody titres between cohorts in March 2006, the mean antibody titre of Cohort₂₀₀₆ was significantly greater than that of Cohort₂₀₀₅ in August 2006. No significant differences were observed in seroprevalence. This is one of the few studies to demonstrate the development of acquired resistance in fish against a parasite in an aquaculture environment under natural infection conditions.     

Liver glycogen synthase in the developing foetal rat

Kinetic constants for liver glycogen synthase (UDPglucose: glycogen 4-alpha-D-glucosyltransferase, EC 2.4.1.11) with respect to UDPglucose have been measured in foetal liver homogenates from samples taken during late gestation (days 17-22) and the first hours after birth. The V of the inactive form of glycogen synthase increased markedly in this period and there was a significant increase in V of the active enzyme to a maximum at day 20 of gestation. The Km for UDPglucose measured in the presence of glucose-6-P (total activity) did not vary greatly, mean values of 0.51 +/- 0.04 mM. Values derived for the inactive enzyme were almost identical. In contrast, Km values for active glycogen synthase in foetal livers during gestation were significantly higher than those for adult liver. Highest values were seen at day 19 of gestation (1.84 +/- 0.08 mM) followed by a steady fall to 0.55 +/- 0.05 mM in the newborn compared with a mean value of 0.48 +/- 0.04 mM for adult liver. Existence of a reduced affinity of active glycogen synthase for UDPglucose must be recognized when assaying the enzyme in foetal liver, particularly when extrapolating values to rates of glycogen synthesis in vivo. Data were obtained only after removal of an amylase-like contaminant from foetal liver samples which invalidated the radioassay of glycogen synthase. This work illustrates the care needed in the analysis of foetal tissue and the interpretation of resulting data when utilizing methods developed for adult tissue.     

Deep brain stimulation: eye movements reveal anomalous effects of electrode placement and stimulation

One of the major difficulties in evaluating the efficacy of deep brain stimulation (DBS), or understanding its mechanism, is the need to distinguish the effects of stimulation itself from those of the lesion inevitably created during surgery. Recent work has shown that DBS of the subthalamic nucleus in Parkinson's disease greatly reduces the time it takes the eyes to make a saccade in response to a visual stimulus. Since this saccadic latency can be rapidly and objectively measured, we used it to compare the effects of surgery and of stimulation. We used a saccadometer to measure the saccadic latencies of 9 DBS patients (1) preoperatively, (2) the day after insertion of subthalamic nucleus electrodes, (3) three weeks later, prior to turning on the stimulator, and (4) after commencement of stimulation. Patients were on their anti-Parkinsonian medication throughout the study. It revealed an entirely unexpected and puzzling finding. As in previous studies an amelioration of symptoms is seen immediately after surgery, and then a further improvement when finally the stimulator is turned on, but in the case of saccadic latency the pattern is different: surgery produces a transient increase in latency, returning to baseline within three weeks, while subsequent stimulation reduced latency. Thus the differential effects of electrode placement and stimulation are completely different for saccades and for more general motor symptoms. This important finding rules out some over-simple interpretations of the mechanism of DBS, and needs to be taken into account in future attempts at modelling the neurophysiology of DBS.     

Multicenter evaluation of the phosphorylcholine-coated biodivYsio stent in short de novo coronary lesions: The SOPHOS study

AIMS: The BiodivYsio trade mark stent (Biocompatibles Ltd, Farnham, UK) is coated with a phosphorylcholine (PC)-containing copolymer to confer biocompatibility. The SOPHOS (Study Of PHosphorylcholine coating On Stents) study was designed to assess the safety and efficacy of this novel coronary stent and by indirect comparison to indicate equivalence with other formal stent studies. METHODS AND RESULTS: Patients with angina and a single short (#x2A7F;12 mm) de novo lesion in a native coronary artery of >/=2.75 mm diameter were included. A total of 425 patients were allocated in 24 centers. Clinical data were collected at one-, six- and nine-month follow-up. Angiography was performed before and after the stent implantation. In addition, in the first 200 patients (SOPHOS A) angiography was routinely performed at six months. The following 225 patients (SOPHOS B) were merely followed up clinically. The primary end-point of the study, the six-month MACE-rate (MACE = Major Adverse Cardiac Events) was 13.4% (two cardiac death; five Q-wave/nine non-Q-wave myocardial infarctions (MI); nine CABG and 32 target lesion revascularization (TLR), which is similar to the calculated 15% MACE-rate in comparable reference studies. Secondary end-points included among others restenosis at six months in the SOPHOS A population. The target vessel diameter was 2.98 +/- 0.48 mm. Minimal lumen diameter pre/post procedure and at follow-up was 1.00 +/- 0.32, 2.69 +/- 0.37, 1.91 +/- 0.71 mm, respectively. The binary restenosis rate (>/=50% diameter stenosis at follow-up) was 17.7%. CONCLUSION: The coronary BiodivYsio stent is safe and effective as a primary device for the treatment of native coronary artery lesions in patients with stable or unstable angina pectoris. Clinical and angiographic results are in the statistical range of equivalence with comparable studies with other current stents.     

A computational investigation of kinetoplastid trans-splicing

Trans-splicing is an unusual process in which two separate RNA strands are spliced together to yield a mature mRNA. We present a novel computational approach which has an overall accuracy of 82% and can predict 92% of known trans-splicing sites. We have applied our method to chromosomes 1 and 3 of Leishmania major, with high-confidence predictions for 85% and 88% of annotated genes respectively. We suggest some extensions of our method to other systems.     

Human exposure to mycotoxins in Egypt

This investigation examined the exposure of Egyptian infants to Aflatoxin M₁ (AfM₁) and of lactating mothers to Aflatoxin B₁, using AfM₁ in human milk as a biomarker for exposure to AfB₁. The presence of ochratoxin A (OA) in human milk was also investigated to determine the levels of infants exposure to OA from human milk. The results indicated that AfM₁ was found in 66 (55 %) of 120 human milk samples with a mean of 0.3 ± 0.53 ng/mL (range 0.02 to 2.09 ng/mL). OA was found in 43 (35.8 %) of 120 human milk samples with a mean of 21.1 ± 13.7 ng/mL (range 5.07 to 45.01 ng/mL), which will cause a daily intake of OA from human milk exceeding the suggested tolerable dose of 5 ng/kg_-1 of OA body weight. On the other side AfM₁ was found in 25 % of blood samples (5 out of 20 samples), at a mean of 1.18 ng/mL, but it was detected only in one urine sample (1 out of 20 samples). OA was detected only in 2 out of 13 blood samples (15.4 %) with an average 3.67 ng/mL. Whereas OA was not detected in all analyzed urine samples.     

Biodiversity of 52 chicken populations assessed by microsatellite typing of DNA pools

In a project on the biodiversity of chickens funded by the European Commission (EC), eight laboratories collaborated to assess the genetic variation within and between 52 populations from a wide range of chicken types. Twenty-two di-nucleotide microsatellite markers were used to genotype DNA pools of 50 birds from each population. The polymorphism measures for the average, the least polymorphic population (inbred C line) and the most polymorphic population (Gallus gallus spadiceus) were, respectively, as follows: number of alleles per locus, per population: 3.5, 1.3 and 5.2; average gene diversity across markers: 0.47, 0.05 and 0.64; and proportion of polymorphic markers: 0.91, 0.25 and 1.0. These were in good agreement with the breeding history of the populations. For instance, unselected populations were found to be more polymorphic than selected breeds such as layers. Thus DNA pools are effective in the preliminary assessment of genetic variation of populations and markers. Mean genetic distance indicates the extent to which a given population shares its genetic diversity with that of the whole tested gene pool and is a useful criterion for conservation of diversity. The distribution of population-specific (private) alleles and the amount of genetic variation shared among populations supports the hypothesis that the red jungle fowl is the main progenitor of the domesticated chicken.     

Quantitative DNA analysis of low grade cervical intraepithelial neoplasia and human papillomavirus infection by static and flow cytometry.

Quantitative deoxyribonucleic acid (DNA) analysis of cervical biopsy specimens from 26 women with cytological, colposcopic, and histological evidence of mild cervical atypia consistent with cervical intraepithelial neoplasia grade I, reactive atypia, or human papillomavirus infection alone or in combination was performed in a comparative evaluation of Feulgen microspectrophotometry, the fast interval processor image analysis system, and flow cytometry. The fast interval processor image analysis system showed a distinct advantage over the other methods, being faster and allowing the operator to see the cells that were selected for measurement. The three methods of measurement together showed that the DNA content of at least 2% of the cells measured exceeded 5C (C being the haploid amount of DNA in a normal cell and 2C representing the diploid complement of a normal cell) in all cases of cervical intraepithelial neoplasia grade I and reactive atypia and in 87% of those reported as showing human papillomavirus infection alone. In contrast, the DNA content of cervical biopsy specimens from the transformation zone of 11 normal controls did not exceed 4C. This study shows the value of using a DNA threshold--that is, the "5C exceeding rate"--to distinguish between normal and neoplastic appearances of the cervix. These results support the view that cervical infection by human papillomavirus is a true precursor of neoplasia.