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Biomedical subjects

C De Castro

Publications and source records attributed to C De Castro.

12 recordsLinked to original sources
PubMed2004

Airborne plane-tree (Platanus hispanica) pollen distribution in the city of Córdoba, South-western Spain, and possible implications on pollen allergy.

Plane-trees are widely grown in Spain as ornaments. This taxon releases large amounts of pollen into the air and this pollen type seems to have proved implications on pollinosis. The aim of this study was to analyse airborne Platanus pollen content in the air of C6rdoba (South-western Spain) over the last 10 years, and its distribution in different areas of the city, as well as to consider possible implications regarding pollen allergies. Results revealed that Platanus pollen concentrations have been at their highest over the last 5 years. Within the city, the lowest pollen concentrations were in Northern areas of the city. Nevertheless, concentrations high enough to be of risk are reached over the whole city. All the patients studied presented symptoms during the Platanus pollen season. We can therefore conclude that plane pollen presents a risk for the whole city although symptoms are more intense and persistent in districts with a higher number of plane-trees. Platanus allergy is a particular problem for city-dwellers, where these trees are commonly used as ornamentals.

Adolescent↗
PubMed2001

Solvent effect on the isomeric equilibrium of carbohydrates: the superior ability of 2,2,2-trifluoroethanol for intramolecular hydrogen bond stabilization.

The higher aptitude of 2,2,2-trifluoroethanol for intramolecular hydrogen bond stabilization in carbohydrates is suggested. This belief, arising from the analysis by 1H NMR spectroscopy of the solvent effect of D2O, DMSO-d6, and 2,2,2-trifluoroethanol-d3 on the isomeric equilibrium of caryophyllose, was also confirmed by shifting of the conformational equilibria of beta-ribopyranose and of its methyl glycoside.

Carbohydrate Conformation↗
PubMed2001

Acetyl substitution of the O-specific polysaccharide caryophyllan from the phenol phase of Pseudomonas (Burkholderia) caryophylli.

The intact O-specific caryophyllan polysaccharide of the lipopolysaccharide fraction from the bacterium Pseudomonas (Burkholderia) caryophylli was isolated for the first time. Its structure was clarified by means of chemical and spectroscopic analysis and consisted of a homopolymer of randomly acetylated caryophyllose units. The position of acetyl groups when present is not unique: all the hydroxyl-groups on the side chain of the sugar can be substituted with a slight preference for acetylation of the C-5-C-10 tail of this unusual monosaccharide

Acetylation↗
PubMed2001

A very efficient method to cleave Lipid A and saccharide components in bacterial lipopolysaccharides.

A novel mild procedure for the selective cleavage of ketosidic linkages is developed using ceric ammonium nitrate (CAN) in anhydrous N,N-dimethylformamide. Its application to lipopolysaccharides (LPS) is very significant because in the so far investigated LPS, the connection between the Lipid A region and the oligo(poly)saccharide part is always a keto-sugar. This procedure has been tested on LPS of Escherichia coli which contains Kdo as a linker between Lipid A and OPS and on Acinetobacter haemoliticus which contains D-glycero-D-talo-2-octulopyranosonic acid (Ko) as a linker and it performed efficiently in both cases.

Acinetobacter↗
PubMed1999

Structural analysis of a novel putative capsular polysaccharide from Pseudomonas (Burkholderia) caryophylli strain 2151.

A novel putative capsular polysaccharide consisting of D-Glcp and D-Fruf in the molar ratio of 1:1 was isolated as minor constituent from the lipopolysaccharide (LPS) fraction of Pseudomonas (Burkholderia) caryophylli. Its structure was determined, using mainly one- and two-dimensional NMR spectroscopy, as: -->6)-alpha-D-Glcp-(1-->1)-beta-D-Fruf-(2-->.

Carbohydrate Sequence↗
PubMed1998

Structural determination of the O-deacetylated O-chain of lipopolysaccharide from Burkholderia (Pseudomonas) cepacia strain PVFi-5A.

On the basis of chemical degradation methods and one-and two-dimensional 1H and 13C NMR experiments the novel following structure was established for the O-deacetylated repeating unit of the O-chain of the main Burkholderia (Pseudomonas) cepacia (strain PVFi-5A) lipopolysaccharide: -->4)-beta-D-GalpNAc-(1-->3)-alpha-D-Galp-(1-->6)-alpha-D-GlcpNAc-(1-->.

Burkholderia cepacia↗
PubMed1998

Chemical structure of two phytotoxic exopolysaccharides produced by Phomopsis foeniculi.

The two main exocellular polysaccharides produced in vitro by Phomopsis foeniculi, a fungal pathogen of fennel, were isolated and characterized by chemical and spectroscopic methods as a galactan with the known structure [-->6)-beta-D-Galf-(1-->5)-beta-D- Galf-(1-->5)-beta-D-Galf-(1-->]n and a mannan. The latter consists of a backbone of alpha-(1-->6)-linked mannopyranose units. Almost all of these are branched at the 2 position with arms containing 2- and 3-linked mannopyranose units. The crude polysaccharide fraction and its components, galactan and mannan, showed phytotoxic effects, i.e. chlorosis, necrosis and/or wilting, on fennel and on two non-host plants, tobacco and tomato.

Ascomycota↗
PubMed1997

Lipopolysaccharides from three phytopathogenic pseudomonads.

Analysis of the polysaccharide and lipid moieties of the lipopolysaccharides (LPSs) of the phytopathogenic bacteria, Pseudomonas amygdali and P. syringae pv. ciccaronei has demonstrated that for both bacteria, the O-chain consists of a tetrasaccharide repeating unit of three alpha-L-Rhap and one terminal nonreducing alpha-D-Fucp3NAc. Two of the rhamnosyl residues are 3-linked, the third one 2,3-linked. This structure had been previously found for the O-chains of three phytopathogenic strains of P. syringae subsp. savastanoi, but this is the first report on its occurrence in P. amygdali and P. syringae pv. ciccaronei. The results of the LPS lipid residue analysis made it possible to make some chemotaxonomic considerations and therefore classify P. amygdali as a chemotype, which is different from that of the other two bacteria examined.

Carbohydrate Conformation↗
PubMed1994

Structural investigation of Ceratozamia spinosa mucilage.

The polysaccharide fraction from Ceratozamia spinosa appears to be made up mainly by a chemically homogeneous polysaccharide but with a wide range of molecular weight. By NMR and chemical degradative methods, it is shown to consist essentially of a backbone of alternate-->4)-beta-D-GlcpA-(1-->and-->2)-alpha-D-Manp-(1--> units. On the 4 position of the latter, beta-D-GlcpA residues are linked. End units of alpha-L-Araf, beta-D-Xylp, alpha-L-Rhap, and alpha-L-3-OMe-Rhap are linked to C-3 and/or C-4 positions of beta-D-GlcpA residues.

Adhesives↗
PubMed1990

Doppler hemodynamic characteristics of four widely used aortic valve prostheses.

Fifty-one patients with normofunctioning aortic prosthetic heart valves were evaluated by Doppler-Echocardiography to determine type-related flow characteristics. The four mechanical valves tested were: Starr-Edwards (1200-1260 aortic), Bjork-Shiley (60 degrees-60 degrees cc aortic), Medtronic-Hall (aortic) and St. Jude Medical (aortic). The most significant dynamic indexes were calculated: Peak (PG) and Mean (MG) Gradient across the valve, Cardiac Index (CI) or Cardiac Output (CO), Regurgitant Jets, Effective Orifice Area (EOA), Spectral Diagram Systolic Trend (SDST) and PVRT (time required to reach peak velocity during systole)/LVET (left ventricular ejection time) Ratio. Patients with Doppler assessed prosthetic dysfunction were dropped out of the study group. As expected, significant reverse correlation (-0.70) was found when transvalvular pressure gradients were compared with valve size. Significant direct correlation (0.82) was found when EOA was compared with valve size, thus suggesting the high reliability of the continuity equation in the assessment of the real orifice area. The Starr-Edwards valve, when compared with the other prostheses of the same size, showed the highest calculated transvalvular gradient; the St. Jude Medical showed the lowest. On the other hand, the Starr-Edwards valve was not commonly associated with regurgitation, while the St. Jude valve was usually moderately incompetent. Those hemodynamic differences should guide the selection of the ideal prosthetic valve for elective surgical indications. Doppler measurements provided noninvasive information similar to that given by cardiac catheterisation, which was reproducible and specific for valve function. According to this high sensitivity and specificity and to the absolute innocuity of the procedure, Doppler-Echocardiography should be considered the elective technique for long-term follow-up in patients with aortic prosthetic heart valves.

Adolescent↗