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Biomedical subjects

V Sanchis

Publications and source records attributed to V Sanchis.

At least 73 records · Page 4Linked to original sources
PubMed1994

A comparison and analysis of the toxicity and receptor binding properties of Bacillus thuringiensis CryIC delta-endotoxin on Spodoptera littoralis and Bombyx mori.

The binding of L-[35S]methionine in vivo labelled CryIC toxin to its receptor in brush border membrane vesicle (BBMV's) prepared from Spodoptera littoralis and Bombyx mori was studied. Both insect species were highly susceptible to the CryIC toxin in bioassays, B. mori being 7-fold more sensitive to CryIC than S. littoralis (LC50's of 10 ng/cm2 and 70 ng/cm2, respectively). Competition and direct binding experiments revealed saturable high-affinity binding sites on BBMV's from both insects which had similar binding characteristics for the CryIC toxin (Kd = 10 nM, Bmax = 8 to 9 pmol/mg BBMV's and IC50 = 37 nM for both inspect species). Thus a specific receptor for the CryIC toxin is present in both insect species and the 7-fold greater potency of CryIC towards B. mori is not due to qualitative or quantitative differences in binding affinity or receptor site concentration. Dissociation experiments also indicated that the binding of [35S]CryIC to B. mori BBMV's is partially reversible.

Animals↗
PubMed1994

A pyruvate decarboxylase gene from Aspergillus parasiticus.

A gene encoding a putative pyruvate decarboxylase (EC 4.1.1.1) was isolated from a genomic library of the filamentous fungus Aspergillus parasiticus strain SU-1. The deduced amino acid sequence showed 37% homology to PDC1 from Saccharomyces cerevisiae. Although A. parasiticus has an obligate growth requirement for oxygen, it produced ethanol in shake flask cultures indicating a response to anoxic conditions mediated by pyruvate decarboxylase.

Amino Acid Sequence↗
PubMed1994

A survey of porcine kidneys and chicken liver for ochratoxin A in Spain.

Contamination studies by ochratoxin A on pork kidney and chicken liver has been carried out in Catalonia (Spain). 73% of the pork kidney samples analyzed did not contain an amount of ochratoxin A over our detection limit (0.5 ng/g) whereas only 7% had contamination higher than 1 ng/g. None of the chicken samples analyzed were contaminated by this toxin above the detection limit. All contamination levels found are below the maximum levels accepted by several countries for this kind of material. A confirmative test is necessary before discarding false positive samples.

Animals↗
PubMed1994

Heat resistance of Saccharomyces cerevisiae strains isolated from spoiled peach puree.

The heat resistance of three Saccharomyces cerevisiae strains isolated from spoiled peach puree, in McIlvaine buffer (pH 4 and 7) and peach puree (pH 3.9) was studied. The D60-values in buffer at pH 7 were 0.75, 1.32 and 0.14 min for the strains 173, 180 and 325, respectively. The pH of the buffer did not influence the heat resistance of the three strains studied. The thermal sensitivity for all strains assayed was higher when peach puree was used with D60-values of 0.53, 0.20 and 0.10 min for the strains 173, 180 and 325, respectively. The menstrua used had limited influence on the z-values, varying between 3 (strain 173, pH 4) and 4 (strain 325, peach puree).

Buffers↗
PubMed1994

Occurrence of fumonisins b(1) and b(2) in corn-based products from the spanish market.

The natural occurrence of fumonisins B(1) and B(2), the incidence of Fusarium organisms, and the capacity of Fusarium isolates to produce fumonisins were investigated with 50 corn-based samples from Spain destined for human consumption. Eight samples (16%) were found to be contaminated with fumonisins. The levels of contamination were very low, with a mean of 80 ng/g.

Journal Article↗
PubMed1993

Identification and partial purification of a Bacillus thuringiensis CryIC delta-endotoxin binding protein from Spodoptera littoralis gut membranes.

Immunoblotting experiments were performed using CryIC and CryIA(c) Bacillus thuringiensis delta-endotoxins to detect the presence of specific toxin binding proteins on Spodoptera littoralis brush border membrane vesicles. The CryIC toxin binds two proteins of 40 and 65 kDa and the CryIA(c) binds a protein of 40 kDa. The CryIA(c) toxin also binds faintly to a 120 kDa protein on S. littoralis brush border membrane vesicles as does a polyclonal antiserum raised against a putative CryIA(c) 120 kDa binding protein from Manduca sexta. The 40 kDa CryIC binding protein was partially purified by affinity chromatography and is therefore a strong candidate for in vivo S. littoralis CryIC toxin receptor.

Animals↗
PubMed1993

Citrinin-producing capacity of Penicillium expansum strains from apple packinghouses of Lerida (Spain).

A study of the citrinin producing capacity in 122 Penicillium expansum strains isolated from apples and various locations of apple packaging premises Lleida (Spain) was conducted. Among the strains examined, 46% produced citrinin in a laboratory substrate and 73.2% of these strains were isolated from decayed apples. All citrinin producing strains produced metabolites which inhibited Bacillus cereus and Bacillus subtilis. The majority of the strains producing citrinin in solid substrate also produced citrinin in apples and apple juices.

Citrinin↗
PubMed1993

Determination of patulin by reversed-phase high-performance liquid chromatography with extraction by diphasic dialysis.

A simple and economical method has been developed for the determination of patulin in apple juice. The sample is extracted with ethyl acetate in a diphasic dialysis system, and the extract is cleaned up by elution from a Sep-Pak cartridge. Patulin is detected and determined by reversed-phase high-performance liquid chromatography using a Novapak C18 column and an ultraviolet detector. The lower detection limit is 1 microgram l-1 and the recovery is 85% at the 20 micrograms l-1 level.

Acetates↗
PubMed1993

Four-part displaced proximal humeral fractures: operative treatment using Kirschner wires and a tension band.

Thirty-five patients with four-part displaced proximal humeral fractures and fracture-dislocations were retrospectively reviewed from the years 1977-1990. Thirty-three patients were available for study. All fractures were treated by open reduction and internal fixation allowing early motion. Surgical technique was as atraumatic as possible with the goal of restoring normal anatomy of the proximal humerus with a minimal fixation system. The fixation device consisted of two modified Kirschner wires introduced through the tuberosities and reinforced by a tension band wiring. Neer's criteria were used to evaluate results. With a mean follow-up of 7 years, results were excellent and satisfactory in 21 cases, nonsatisfactory in 10, and poor in two. The most common complication was avascular necrosis (nine patients). All cases of fracture-dislocations corresponded with the nonsatisfactory and poor results. Because of our results, we conclude that in four-part displaced fractures, open reduction and internal fixation with our system of osteosynthesis should be indicated initially. Prosthetic replacement should be considered as primary treatment in cases with marked comminution of the humeral head, in fracture-dislocations, and in patients > 75 years of age.

Adult↗
PubMed1993

Effects of potassium sorbate on growth and penicillic acid production by Aspergillus ochraceus and Penicillium aurantiogriseum.

The effect of potassium sorbate on the growth and penicillin acid production of Aspergillus ochraceus and Penicillium aurantiogriseum was studied. Yeast extract sucrose (YES) broth at initial pH values of 5.5 or 7.0, and containing different concentrations of potassium sorbate was inoculated with fungal spores and incubated for 35 days at 28 degrees C. In all cases, although the pH changes in sorbate-containing media were delayed, patterns were similar to those of the cultures without sorbate. This was most evident when the highest concentration of potassium sorbate was used. Potassium sorbate also inhibited mycelial growth. Penicillic acid production was initially delayed by the presence of potassium sorbate but this inhibition was eventually overcome (30-35 days) and penicillic acid levels at the end of the experiment were similar or higher then the controls. Generally cultures growing in culture media at an initial pH of 5.5 produced less toxin than those growing at pH 7.0.

Aspergillus ochraceus↗
PubMed1993

[Applications of molecular biology techniques for the control of aflatoxin contamination].

Aflatoxins are mycotoxins produced by species of Aspergillus flavus group. These toxins have received increased attention from the food industry and the general public because they shown a high toxicity against humans and animal. Different methods are applying to control the aflatoxin contamination. But these conventional methods do not seem to resolve the problem. So, new methods using techniques in biotechnology are now being developed: a) Inhibit the biosynthetic and secretory process responsible for aflatoxin contamination. b) Using biocompetitive agents that replace aflatoxigenic strains with non aflatoxigenic strains in the field. c) Using genetic engineering techniques to incorporate antifungal genes into specific plant species.

Aflatoxins↗
PubMed1990

Potential for the development of tolerance by Aspergillus amstelodami, A. repens and A. ruber after repeated exposure to potassium sorbate.

Three strains of A. amstelodami, A. repens and A. ruber were exposed to various levels of potassium sorbate, and the MICs were determined. Selected strains of the molds were then repeatedly exposed to subinhibitory levels of the compound to determine whether increased tolerance might develop. The MIC of sorbate (pH 5.5 or 6.5) for 3 species of Aspergillus was 0.07%. Increasing levels of sorbate resulted in increasing growth suppression of the molds. The 3 Aspergillus species were tested for increased tolerance to potassium sorbate, and none was found. They developed a slight increase in tolerance dependent upon pH and the mold strain by subculturing at low levels of sorbate.

Aspergillus↗
PubMed1989

Nucleotide sequence and analysis of the N-terminal coding region of the Spodoptera-active delta-endotoxin gene of Bacillus thuringiensis aizawai 7.29.

The nucleotide sequence of a 2711bp DNA segment which contains the N-terminal coding sequence and the 5' flanking region of a crystal protein gene (bta) from Bacillus thuringiensis subsp. aizawai 7.29 has been determined. The coding region encodes an 824 amino-acid polypeptide corresponding to a carboxy-terminally truncated delta-endotoxin specifically active against the cotton leaf worm Spodoptera littoralis. Comparison of the deduced amino acid sequence of the bta gene with that of the 4.5, 5.3 and 6.6 kb classes of lepidopteran-active delta-endotoxins revealed that the Bta sequence contains a very high level of amino acid substitutions in the N-terminal part of the protoxin molecule. The substitutions are grouped in several highly variable segments separated by highly conserved regions. These conserved domains are also present in the dipteran- and coleopteran-active delta-endotoxins. The control region of the bta gene shows considerable DNA identity with the control regions of the other lepidopteran-active genes. Deletions of the 3' region of the gene were carried out and the toxic fraction of the bta delta-endotoxin was identified with the N-terminal half of the molecule.

Amino Acid Sequence↗
PubMed1988

Mycotoxin-producing potential of fungi isolated from red kidney beans.

The predominant fungi present in samples of reject and retail red kidney beans were Aspergillus glaucus, Penicillium spp. and Alternaria spp. Together with A. ochraceus, A. flavus, Fusarium spp., and Trichoderma, these isolates from the reject beans were screened for numerous mycotoxins by TLC. The most consistently produced mycotoxins were penicillic acid (from A. ochraceus and Penicillium spp.) and Alternaria toxins (tenuazonic acid and alternariol). A. glaucus strains were tested for cytotoxicity in three tissue culture cell lines with positive results.

Aspergillus↗
PubMed1988

Long-term results after conventional total meniscectomy: a point of reference.

We have reviewed 167 conventional total meniscectomies with the aim of analyzing the long-term results. One hundred and twenty-five patients came to the hospital for personal view, and the Lysholm test was applied in each case. There was a 14.4% diagnostic error that caused us to remove the meniscus without demonstrable pathology. A systematic introduction of diagnostic arthroscopy has clearly modified this situation. A decision to remove a meniscus should not be based solely on clinical findings; arthroscopic confirmation is necessary. The overall acceptable results (64.5%) revealed that conventional total meniscectomy is not an operation that belongs in the past. We believe it is an alternative to be considered every time diagnostic arthroscopy shows that it is impossible to leave a stable and uniform meniscal rim.

Absenteeism↗
PubMed1988

Multiplicity of delta-endotoxin genes with different insecticidal specificities in Bacillus thuringiensis aizawai 7.29.

The hypothesis according to which multiple and different delta-endotoxin genes could determine the host-range specificity of the lepidopteran strains of Bacillus thuringiensis is being checked in the case of strains aizawai 7.29 (serotype 7) and entomocidus 601 (serotype 6). From these strains, several crystal protein genes, belonging to different structural types, have been isolated. One of the cloned genes that is not present in strain entomocidus 601 is duplicated in strain aizawai 7.29. This gene belongs to a previously characterized type of crystal protein gene and encodes a protein preferentially active against Pieris brassicae. Two other genes, of presumed chromosomal location, are present in both strains and each displays a unique physical map. In both strains the two genes are in close proximity and in the same orientation. The first, which belongs to a new type of crystal protein gene, encodes a 130-140 kD protein that is not significantly active against the two insect species tested. The other new type of crystal protein gene directs the synthesis of a polypeptide preferentially active against Spodoptera littoralis.

Animals↗
PubMed1988

Identification of a delta-Endotoxin Gene Product Specifically Active against Spodoptera littoralis Bdv. among Proteolysed Fractions of the Insecticidal Crystals of Bacillus thuringiensis subsp. aizawai 7.29.

At least three different insecticidal crystal protein genes were shown to be expressed in Bacillus thuringiensis subsp. aizawai 7.29, a strain that is potentially active against the cotton leafworm Spodoptera littoralis Bdv. Among crude K-60 fractions (60- to 70-kilodalton [kDa] molecules) that were products of proteolysed crystals containing the active domains of the protoxin molecules, we were able to distinguish several distinct components on the basis of their antigenic relationship and their larvicidal properties. A purified fraction designated SF2 was a 61-kDa component specifically active against Pieris brassicae L. and homologous to the B. thuringiensis subsp. berliner 1715 plasmid-encoded crystal protein. A second fraction designated SF1 was composed of 63- and 65-kDa polypeptides and was specifically active against S. littoralis. The SF1 fraction and particularly the 65-kDa component were not antigenically related to the 61-kDa component. The purified fractions were compared with the products of three different crystal protein genes we previously cloned from total DNA of B. thuringiensis subsp. aizawai, among them a new type of crystal protein gene encoding a protein that is specifically active against S. littoralis and other insects of the Noctuidae family. This approach led us to consider the 65-kDa component as a minimum active part of a delta-endotoxin that is encoded by this new gene. Products of the two other cloned genes can be correlated with the 61- and 63-kDa components, respectively. Thus, in B. thuringiensis subsp. aizawai 7.29, multiple delta-endotoxin genes of different structural types direct the synthesis of several delta-endotoxins with different host specificities which were identified as components of the insecticidal crystals.

Journal Article↗