Control of the rate of phosphocreatine resynthesis after exercise in trained and untrained human quadriceps muscles

We examined the effect of differences in exercise intensity on the time constant (t _c) of phosphocreatine (PCr) resynthesis after exercise and the relationships betweent _c and maximal oxygen uptake (VO_2max) in endurance-trained runners (n = 5) and untrained controls (n = 7) (average VO_2max = 66.2 and 52.0 ml · min^–1 · kg^–1, respectively). To measure the metabolism of the quadriceps muscle using phosphorus nuclear magnetic resonance spectroscopy, we developed a device which allowed knee extension exercise inside a magnet. All the subjects performed four types of exercise: light, moderate, severe and exhausting. The end-exercise PCr: [PCr + inorganic phosphate (P_i)] ratio decreased significantly with the increase in the exercise intensity (P < 0.01). Although there was little difference in the end-exercise pH, adenosine diphosphate concentration ([ADP]) and the lowest intracellular pH during recovery between light and moderate exercise, significant changes were found at the two higher intensities (P < 0.01). These changes for runners were smaller than those for the controls (P < 0.05). The _c remained constant after light and moderate exercise and then lengthened in proportion to the increase in intensity (P < 0.05). The runners had a lowert _c at the same PCr and pH than the controls, particularly at the higher intensity (P < 0.05). There was a significant correlation betweent _c and [ADP] in light exercise and betweent _c and both end-exercise PCr and pH in severe and exhausting exercise (P < 0.05). The threshold of changes in pH andt _c was a PCr: (PCr + P_i) ratio of 0.5. There was a significant negative correlation between the VO_2max andt _c after all levels of exercise (P<0.05).However, in the controls a significant correlation was found in only light and moderate exercise (P < 0.05). These findings suggest the validity of the use oft _c at an end-exercise PCr:(PCr + P_i) ratio of more than 0.5 as a stable index of muscle oxidative capacity and the correlation between local and general aerobic capacity. Moreover, endurance-trained runners are characterized by the faster PCr resynthesis at the same PCr and intracellular pH.     

A chitin sulfate-like polysaccharide from the test of the tunicate Halocynthia roretzi

Considerable amounts of water-soluble polysaccharides were found in the test of the tunicate Halocynthia roretzi. After fractionation with ethanol, a chitin sulfate-like polysaccharide was isolated. From the results of chemical analysis, optical rotation, infrared spectrum and alkaline treatment, it is suggested that the predominant structure for this polysaccharide is (1→4)-2-acetamido-2-deoxy-6-O-sulfo-β-D-glucopyranan.     

Dynamics of a biofouling community in finfish aquaculture: a case study from the South Adriatic Sea

Biofouling is one of the challenges that can strongly affect the finfish farm economy. Although several studies on biofouling in aquaculture have been conducted in the Mediterranean Sea, they focused on specific taxa or were limited to a particular period of sampling. The present study investigated for the first time the development, composition and variation in a biofouling community in a finfish farm with immersion time, season and depth. The results indicate that all these factors influence biofouling succession and recruitment. Moreover, the species that had a crucial role in structuring the community and in the farm cleaning activities were the ascidian Styela plicata and the bivalve Mytilus galloprovincialis. Compared with the literature data, the results highlight the heterogeneity in the composition of the biofouling present in the Mediterranean Sea. Moreover, such knowledge of the biofouling community could provide important information about management efforts and the costs that farmers will face when siting new fish farms.     

Isolation and Purification of Fucoidin from Brown Seaweed Pelvetia wrightii

A highly purified fucoidin was isolated from Pelvetia wrightii by an improved method, which involves the removal of alginate with calcium chloride solution and purification with cetylpyridinium chloride (CPC).

To this end, the critical salt concentrations of the cetylpyridinium complex of alginic acid and fucoidin in salt solutions (KCl, NaCl, CaCl₂) were determined.

The fucoidin of this alga contained both fucose and galactose as its constituents, in a ratio of approximately 10:1, and it is considered to be a galactofucan sulfate.     

Isolation and identification of mycobacteria from livestock specimens and milk obtained in Brazil

The prevalence of Mycobacterium bovis and other mycobacterial species in livestock specimens and milk was evaluated. An emphasis was placed upon the distribution of these organisms in milk that is readily available to the public that was either untreated, pasteurized, or treated using ultra high temperature. Twenty-two pathologic specimens from livestock (bovine, swine and bubaline) in five Brazilian states and 128 bovine milk samples from retail markets in the State of S o Paulo were examined for mycobacteria. Identification was made by classical biochemical tests, thin layer chromatography of mycolic acids and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Mycobacteria were isolated from 15 (68.2%) caseous lesions and from 23 (18%) milk samples. Eleven isolates were identified as M. bovis, and the remaining 27 nontuberculous mycobacterial isolates were represented by five species and six unidentified rapidly growing mycobacterial strains. The data demonstrate that animal products in Brazil are frequent reservoirs of mycobacteria and may pose a risk to the public.     

Synthesis of DNA conjugates by solid phase fragment condensation

Development of a novel method for the synthesis of DNA conjugates is described. Oligonucleotides were successfully conjugated with a variety of functional molecules on a solid phase (Solid Phase Fragment Condensation) using an amino, a hydroxyl, a thiol, and a carboxyl group. DNA-peptide conjugate was obtained as a pure from by a single RPHPLC purification approximately in 20% yield. Moreover, it was demonstrated that the present method was effective for the preparation of conjugate molecules, DNA-sugar, DNA-polyamine, DNA-lipid and so on. The study to create new intelligent DNAs by accumulation various biofunctions on the molecule by SPFC is now in progress in our laboratory.     

Precise Stent Placement Using the New Siemens Artis Zeego 3D Rotation Angiography in a Stenosis of a Shelhigh Pulmonary Conduit

Stenting of the Shelhigh pulmonary conduit was performed 2 years after a Ross procedure because of a stenosis of the distal segment. We used the new Siemens Artis Zeego technology. A precise placement of the stent to release the stenosis within the distal segment simultaneously retaining a competent valve was possible by using the Dyna-computed tomography technology. The early onset of a stenosis of the Shelhigh xenograft in the pulmonary position is alarming, thus, its use can not be recommended for a replacement of the pulmonary valve.     

Techniques of SNP genotyping and remote sensing applied for elucidation of the contribution of polygene and environmental factors to inter-individual variation in skin pigmentation phenotype

We present a conceptual framework for applying techniques of SNP genotyping as a molecular biological approach and remote sensing as an ecological approach to elucidation of the contribution of polygene and environmental factors to inter-individual variation in skin pigmentation phenotype. Additionally, we discuss the obstacles that frustrate our efforts to identify how the human genome encodes the complex phenotype and suggest the use of computational methods designed for knowledge discovery within hereditary database.     

Polymorphism of pyridinium amphiphiles for gene delivery: influence of ionic strength, helper lipid content, and plasmid DNA complexation

Two double-tailed pyridinium cationic amphiphiles, differing only in the degree of unsaturation of the alkyl chains, have been selected for a detailed study of their aggregation behavior, under conditions employed for transfection experiments. The transfection efficiencies of the two molecules are remarkably different, especially when combined with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as helper lipid. The phase behavior of the cationic amphiphile/DOPE mixtures have been studied using (31)P- and (2)H-NMR (on deuterated cationic amphiphiles) as main techniques, to monitor independently the behavior of the two components. In water, the lamellar organization is dominant for both the surfactants in their mixtures with the helper lipid. In HEPES saline buffer (HBS), the mixtures of the unsaturated surfactant form inverted phases and, in particular, stable H(II) phases for DOPE contents > or =30 mol %. By contrast, the saturated surfactant does not form homogeneously mixed inverted phases in mixtures with DOPE at room temperature. However, mixed inverted phases are observed for this system at higher temperatures and, after mixing has been achieved by heating, the metastable mixed phases remain present for several hours at 5 degrees C. At 35 degrees C the dominant phase is the cubic phase. The lipoplex composed of equimolar mixtures of the unsaturated surfactant with DOPE and plasmid DNA was found to be organized in highly curved bilayers.