Complete nucleotide sequences of bovine alpha S2- and beta-casein cDNAs: comparisons with related sequences in other species

The nucleotide sequences corresponding to bovine alpha S2- and beta- casein mRNAs have been determined by cDNA analysis. Both sequences appear to be complete at their 5' ends. The nucleotide sequence of alpha S2-casein, when compared with the corresponding cavine A sequence, helps to define the boundaries of a large amino acid repeat (approximately 80 residues) whereas comparisons with the nucleotide sequences of rat gamma- and mouse epsilon-casein mRNAs also reveal extensive sequence similarities. An alignment of these four sequences shows that the divergence of their translated regions has been characterized by the duplication and deletion of discrete segments of sequence that probably correspond to exons. A high degree of nucleotide substitution is also found when the four sequences are compared, except for well-conserved leader-peptide and phosphorylation-site sequences and, to a lesser extent, the 5'-untranslated regions. Similar comparison of the bovine and rat beta-caseins shows that their divergence has involved a high rate of nucleotide substitution but that no major insertions or deletions of sequence have occurred. The several splice sites that have veen defined in the rat beta-casein gene are likely to have been conserved in the bovine. The contrasting evolutionary histories of the alpha- and beta-casein coding sequences correlate with the distinctive functions of these proteins in the casein micelle system in milk.      

Effects of ibuprofen and pentoxifylline on the cardiovascular response of normal humans to endotoxin.

Endotoxin is a major mediator of the life-threatening cardiovascular dysfunction that characterizes Gram-negative sepsis. In animal models of endotoxemia, pretreatment with ibuprofen or pentoxifylline attenuates some of these cardiovascular changes. To evaluate the effects of these agents on the human cardiovascular response to endotoxemia, hemodynamic variables were measured serially in 24 normal subjects who were given intravenous endotoxin. The subjects were randomized to receive oral ibuprofen (n = 9), pentoxifylline (n = 10), or no medication before endotoxin administration (n = 5). The subjects were volume loaded 3-5 h after endotoxin administration, and hemodynamic measurements were reassessed. Core temperature after endotoxin alone or endotoxin-pentoxifylline approached a maximum at 3 h (greater than or equal to 38.6 degrees C), while the endotoxin-ibuprofen group remained afebrile. At 3 and 5 h, all three groups had significant increases in heart rate, cardiac index, oxygen delivery, and oxygen consumption, while systemic vascular resistance index decreased significantly from baseline. The oxygen extraction ratio remained unchanged. After volume loading, the left ventricular ejection fraction and left ventricular end-diastolic and end-systolic volume indexes did not differ among the groups. The hyperdynamic cardiovascular response to endotoxin in humans occurs in the absence of fever and is not significantly ameliorated by oral cyclooxygenase or phosphodiesterase inhibition.     

Inflammatory remodeling of the HDL proteome impairs cholesterol efflux capacity

Recent studies demonstrate that HDL’s ability to promote cholesterol efflux from macrophages associates strongly with cardioprotection in humans independently of HDL-cholesterol (HDL-C) and apoA-I, HDL’s major protein. However, the mechanisms that impair cholesterol efflux capacity during vascular disease are unclear. Inflammation, a well-established risk factor for cardiovascular disease, has been shown to impair HDL’s cholesterol efflux capacity. We therefore tested the hypothesis that HDL’s impaired efflux capacity is mediated by specific changes of its protein cargo. Humans with acute inflammation induced by low-level endotoxin had unchanged HDL-C levels, but their HDL-C efflux capacity was significantly impaired. Proteomic analyses demonstrated that HDL’s cholesterol efflux capacity correlated inversely with HDL content of serum amyloid A (SAA)1 and SAA2. In mice, acute inflammation caused a marked impairment of HDL-C efflux capacity that correlated with a large increase in HDL SAA. In striking contrast, the efflux capacity of mouse inflammatory HDL was preserved with genetic ablation of SAA1 and SAA2. Our observations indicate that the inflammatory impairment of HDL-C efflux capacity is due in part to SAA-mediated remodeling of HDL’s protein cargo.     

Comparison of different biochemical and molecular methods for the identification of Vibrio parahaemolyticus

AIMS: Multicentre evaluation of biochemical and molecular methods for the identification of Vibrio parahaemolyticus. METHODS AND RESULTS: For the biochemical identification methods, API 20E and API 20NE and Alsina's scheme were evaluated in intra- and interlaboratory tests in order to determine the accuracy and concordance of each method. Both in intra- and interlaboratory tests, the Alsina's scheme showed the highest sensitivity (86% of correct identifications in the interlaboratory test). False-positive results were obtained by all methods (specificity was 95% for API 20E, 73% for API 20NE and 84% for Alsina's scheme) and concordance varied from 65% of API 20NE to 84% of API 20E. For the molecular identifications, polymerase chain reaction (PCR) for the detection of toxR gene, tl gene and pR72H fragment were tested on 30 strains by two laboratories. The PCR for toxR showed the highest inclusivity (96%), exclusivity (100%) and concordance (97%). CONCLUSIONS: Among the biochemical identification methods tested, the Alsina's scheme gave more reliable results; however, in order to avoid false-positive results, all the biochemical identifications should be confirmed by means of molecular methods. SIGNIFICANCE AND IMPACT OF THE STUDY: Availability of an efficient identification method of Vibrio parahaemolyticus to use in official control of fisheries products.     

Adaptive evolution of G-protein coupled receptor genes

The phylogeny and patterns of nucleotide substitutions in the visual pigment genes, adrenergic receptor genes, muscarinic receptor genes, and in the human mas oncogene were studied by comparing their DNA sequences. The evolutionary tree obtained shows that the visual pigment genes and mas oncogene form one cluster and that the receptor genes form another. In the evolution of rhodopsin genes, synonymous substitutions outnumber nonsynonymous substitutions. This is consistent with the neutral theory of molecular evolution. However, the early evolutionary stages of alpha- and beta-adrenergic and muscarinic receptors are notable for significantly more nonsynonymous substitutions than synonymous substitutions, suggesting the acquisition of novel functional adaptations. Variable rates of nonsynonymous changes in different domains of these proteins reveal DNA segments that might have been important in their functional adaptations.      

Aspergillus terreus and its toxic metabolites as a food contaminant in some Egyptian Bakery products and grains

A. terreus isolates isolated from some bakery products, corn and rice were found to be able to produce territrems. 90% of theA. terreus isolated from bakery products were able to produce territrem A, with a mean of 0.09 ppm, while 80% ofA. terreus isolates produce territrem B with a mean of 0.24 ppm. On the other hand 31.8% of the isolates ofA. terreus from corn were able to produce territrem A with a mean of 0.44 ppm. ConcerningA. terreus isolates from rice, 66.7% were found to produce territrem A, with a mean of 5.28 ppm, and 77.8% of the isolates produced territrem B with a mean of 1.79 ppm.     

Occurrence of enteric viruses in shellfish and relation to climatic-environmental factors

Aims: To investigate the presence of enteric viruses [hepatitis A (HAV) and norovirus (NoV)] in shellfish harvested from the deltaic area of the Po river in relation to environmental factors. Methods and Results: Fortnightly sampling of shellfish was carried out in two lagoon areas (category B production areas) and one sea area (category A). Environmental parameters in the lagoon and hydrometric level of the tributary river were monitored throughout the sampling period. Samples (n = 120) were analysed for bacterial (E. coli and Salmonella) and viral (HAV and NoV) contamination; samples from category B areas were analysed before and after purification treatment. All the samples were negative for HAV whereas 10 samples (8·3%), all harvested in the lagoon areas, were positive for NoV. Sequencing identified the strains as genotypes II.4 and II.b. None of the samples was found to be contaminated after depuration. Conclusions: The monitoring showed a low frequency of NoV presence; viral contamination, detected exclusively in shellfish collected from the deltaic area (category B), could be influenced by the flow of the tributary river. Significance and Impact of the Study: The data collected are useful for the design of targeted prevention strategies and for the modulation of control plans after meteorological events.