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Biomedical subjects

P Blanco

Publications and source records attributed to P Blanco.

At least 37 records · Page 2Linked to original sources
PubMed1999

Production of pectic enzymes in yeasts.

When grown in the appropriate medium, several yeast species produce pectinases able to degrade pectic substances. It is mainly exocellular endopolygalacturonases that break pectins or pectate down by hydrolysis of alpha-1,4-glycosidic linkages in a random way. Biochemical characterisation of these enzymes has shown that they have an optimal pH in the acidic region and an optimal temperature between 40 and 55 degrees C. Their production by yeasts is a constitutive feature and is repressed by the glucose concentration and aeration. Pectic substances and their hydrolysis products are used as carbon sources by a limited number of yeasts and hence these enzymes must be involved in the colonisation of different parts of plants, including fruits. The first yeast pectic enzyme (encoded by the PSE3 gene) was cloned from Tichosporon penicillatum. Recently, a polygalacturonase-encoding gene from Saccharomyces cerevisiae has been cloned and overexpressed in several strains and the gene for an extracellular endopolygalacturonase from Kluyveromyces marxianus has also been described. Taking all the results together, the idea is now emerging that this type of yeast enzyme could offer an alternative to fungal enzymes for industrial applications.

Amino Acid Sequence↗
PubMed1999

An exon map of the AZFc male infertility region of the human Y chromosome.

STS markers spanning the AZFc region of human Y Chromosome (Chr) were used to isolate a series of 14 P1 artificial chromosome (PAC) clones covering at least 560 kb of DNA. End clone analysis of these PAC clones was used to derive 10 new STS markers. Together with other markers mapped to the region, an STS content analysis was used to assemble these PAC clones into three distinct contigs. A minimum tiling path of ten PAC clones was subjected to exon trapping to identify potentially new genes mapping to the AZFs region. In all, 39 potential exons were isolated, including 2 exons from the DAZ gene, 3 exons from the BPY2 gene, 2 exons from the PRY gene, and 1 exon from a member of the RBM II gene family; all these genes have been shown previously to map to the AZFc region. One further exon was found that shows homology to the DFFRY gene, which maps to Yq11. 2, indicating that there may be a further copy of this gene or a pseudogene in the distal Yq euchromatin. The majority of the remaining potential exons appear to be novel, suggesting that additional genes lie in the AZFc region. Mapping of these exons by PCR analysis of somatic cell hybrids has shown that six of these exons are homologous to autosomal sequences, and five to sequences on the X Chr. RT-PCR analysis of primary cDNA from adult testis, brain, liver, and skeletal muscle mRNA has shown that 11 of the novel exons are expressed in one or a combination of these tissues, indicating that they form parts of genuine transcripts.

Brain↗
PubMed1999

[Group B streptococcal meningitis revealing an inner ear congenital malformation. A case report in an adult].

INTRODUCTION: Group B streptococcal meningitis is unusual in adults. It occurs in patients with a chronic disease. EXEGESIS: We report a case of group B streptococcal meningitis that occurred in a 32-year-old woman, uncovering inner ear congenital malformation associated with cerebrospinal fluid fistula. There was no recurrent episode of meningitis during a 2-year period following surgical correction of the malformation. CONCLUSION: Clinical signs suggesting cerebrospinal fluid fistula should be considered in any adult patient with severe group B streptococcal infection.

Adult↗
PubMed1999

Surgical treatment of an endovascular metastatic melanoma of the superior vena cava.

A 42-year-old woman, who had undergone excision of a melanoma of her right forearm 3 years before (Breslow's index 4.4 mm), was admitted to hospital for the evaluation of an superior vena cava syndrome. The thoracic CT scan and the phlebography showed obstruction of the superior vena cava by an endovascular tumor. Abdominal, pelvis and cranial CT scans did not reveal any other metastatic localization. Surgery with extracorporeal circulation was performed. The mass was resected and histopathologic examination confirmed the endovascular metastatic melanoma. There was no heart metastasis. The patient was then given a polychemotherapy. She was still alive after 18 months of follow-up after the initial metastasis. To our knowledge, no similar case has previously been reported and surgical treatment, as for isolated heart metastatic melanoma, may be considered for vascular metastasis, as in our case.

Adult↗
PubMed1999

A new rectal model for dosimetry applications.

UNLABELLED: A revised geometric representative model of the lower part of the colon, including the rectum, the urinary bladder and prostate, is proposed for use in the calculation of absorbed dose from injected radiopharmaceuticals. The lower segment of the sigmoid colon as described in the 1987 Oak Ridge National Laboratory mathematical phantoms does not accurately represent the combined urinary bladder/rectal/prostate geometry. In the revised model in this study, the lower part of the abdomen includes an explicitly defined rectum. The shape of sigmoid colon is more anatomically structured, and the diameters of the descending colon are modified to better approximate their true anatomic dimensions. To avoid organ overlap and for more accurate representation of the urinary bladder and the prostate gland (in the male), these organs are shifted from their originally defined positions. The insertion of the rectum and the shifting of the urinary bladder will not overlap with or displace the female phantom's ovaries or the uterus. In the adult male phantom, the prostatic urethra and seminal duct are also included explicitly in the model. The relevant structures are defined for the newborn and 1-, 5-, 10- and 15-y-old (adult female) and adult male phantoms. METHODS: Values of the specific absorbed fractions and radionuclide S values were calculated with the SIMDOS dosimetry package. Results for 99mTc and other radionuclides are compared with previously reported values. RESULTS: The new model was used to calculate S values that may be crucial to calculations of the effective dose equivalent. For 131I, the S (prostate<--urinary bladder contents) and S (lower large intestine [LLI] wall<--urinary bladder contents) are 6.7 x 10(-6) and 3.41 x 10(-6) mGy/MBq x s, respectively. Corresponding values given by the MIRDOSE3 computer program are 6.23 x 10(-6) and 1.53 x 10(-6) mGy/MBq x s, respectively. The value of S (rectum wall<--urinary bladder contents) is 4.84 x 10(-5) mGy/MBq x s. For 99mTc, we report S (testes<--prostate) and S (LLI wall<--prostate) of 9.41 x 10(-7) and 1.53 x 10(-7) mGy/MBq x s versus 1.33 x 10(-6) and 7.57 x 10(-6) mGy/MBq x s given by MIRDOSE3, respectively. The value of S (rectum wall<--prostate) for 99mTc is given as 4.05 x 10(-6) mGy/MBq x s in the present model. CONCLUSION: The new revised rectal model describes an anatomically realistic lower abdomen region, thus giving improved estimates of absorbed dose. Due to shifting the prostate gland, a 30%-45% reduction in the testes dose and the insertion of the rectum leads to 48%-55% increase in the LLI wall dose when the prostate is the source organ.

Adult↗
PubMed1999

[Joint involvement in AL amyloidosis].

This review is aimed at defining the frequency, the clinical, biological and radiological presentation and the therapeutic possibilities for AL amyloid arthropathies. The frequency of AL amyloid arthropathy is estimated to be between 2 and 5%. There is usually a bilaterally progressive symmetrical arthritis of multiple joints (predominantly in the upper limb joints) with a chronic evolution. Neurologic or cutaneous symptoms are common. The analysis of synovial fluid sediments is a key test for the diagnosis of amyloid arthropathy. Patients with amyloid arthropathy must be screened for monoclonal gammapathies. The synovectomy is the best symptomatic treatment. A better knowledge of the pathogenesis of amyloid deposits should permit to improve therapeutical strategies.

Adult↗
PubMed1998

Affinity chromatography purification of mitochondrial inner membrane proteins with calcium transport activity.

Immobilized calcium affinity chromatography was used to obtain a preparation enriched in calcium transporters from Triton X-100 extracts of rat liver mitochondria inner membranes (PPCT). The PPCT were reconstituted into preformed asolectin liposomes which contained 120 mM KCl as internal high K+ medium. 45Ca2+ uptake into proteoliposomes was studied under conditions favoring electrophoretic uptake, and H+i/45Ca2+o or Na+i/45Ca2+o exchange, to test for the presence of the three calcium transport modes present in mitochondria. 45Ca2+ uptake in liposomes was studied in parallel. Na+i/45Ca2+o exchange activity was not detectable. H+i/45Ca2+o exchange activity measured in the presence of a pH gradient (acid inside) obtained after suspension in low K medium in the presence of nigericin, was 100-200 nmoles 45Ca2+ per mg protein in 30 s. 45Ca2+ uptake in voltage-dependent assays (a K+ diffusion membrane potential induced by valinomycin in the presence of methylamine) was not electrophoretic since it was stimulated by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and probably due to secondary Ca2+/H+ countertransport. H+i/45Ca2+o uptake showed a saturable component at around 80 microM Ca and was coupled to an increase in internal pH in pyranine-loaded PPCT proteoliposomes. 45Ca2+ uptake in PPCT proteoliposomes could also be driven by a pH gradient obtained by raising external pH in high K+ medium. The results are consistent with the presence of a functional nH+/Ca2+ antiporter. Polyclonal antibodies raised against the PPCT were able to immunoprecipitate the H+/45Ca2+ uptake activity and recognized two major bands in the PPCT with molecular masses of about 66 kDa and 55 kDa. This is the first report of a partial purified protein(s) which may represent the H+/Ca2+ exchanger of the inner mitochondrial membrane, and represents an important step towards its identification.

Animals↗
PubMed1998

Cloning, molecular characterization, and expression of an endo-polygalacturonase-encoding gene from Saccharomyces cerevisiae IM1-8b.

A structural polygalacturonase-encoding gene (PGU1) from Saccharomyces cerevisiae IM1-8b was cloned and sequenced. The predicted protein comprises 361 amino acids, with a signal peptide between residues 1 and 18 and two potential glycosylation points in residues 318 and 330. The putative active site is a conserved histidine in position 222. This polygalacturonase showed 54% homology with the fungal ones and only 24% homology with their plant and bacterial counterparts. The gene is present in a single gene copy per haploid genome and it is detected in all strains, regardless of their phenotype. The expression of PGU1 gene in several strains of S. cerevisiae revealed that the polygalacturonase activity depended on the plasmid used and also on the genetic background of each strain but in all cases the enzymatic activity increased.

Amino Acid Sequence↗
PubMed1997

Cloning of a new FLO gene from the flocculating Saccharomyces cerevisiae IM1-8b strain.

A flocculation conferring gene was cloned from a genomic library of the flocculating strain Saccharomyces cerevisiae IM1-8b as a 5 kb DNA fragment. The shortest DNA fragment (XbaI-XbaI) able to confer the flocculating phenotype was 3.1 kb. Southern analysis revealed that this gene was not homologous to the already reported FLO1 gene since strong hybridization signals were obtained when chromosomes IV and XII were probed with a digoxygenin-labelled fragment and no signal at all was detected for chromosome I. Partial sequencing data unequivocally ascribed the cloned fragment to chromosome XII. The gene was detected in a variety of S. cerevisiae strains regardless of their being phenotypically flocculating. This gene which, we propose as FLO2, is able to complement the flo1 mutation and is suppressed by suppressors (fsu3) that do not affect other FLO genes.

Chromosome Mapping↗
PubMed1997

Use of cardiac troponin T rapid assay in the diagnosis of a myocardial injury secondary to electrical cardioversion.

BACKGROUND AND HYPOTHESIS: This study was carried out to determine whether cardiac troponin T test in rapid assay gives positive results in patients previously submitted to cardioversion or electrical defibrillation. METHODS: Forty patients with supraventricular tachyarrhythmias lasting no more than 2 days were treated with electrical cardioversion. The total creatine phosphokinase (CPK)-MB isoenzyme and troponin T in rapid assay were measured at baseline and at 6, 12, and 24 h thereafter. RESULTS: Total CPK baseline levels were normal in all cases; within 4 h, the serum CPK levels increased by 98%, at 6 h by 111.5%, at 12 h by 168%, and at 24 h by 225% (p > 0.01). The CPK-MB isoenzyme showed no percentage increase of total CPK higher than 5%, measured at 6, 12, and 24 h after the shock, independent of the number of attempts of cardioversion. The troponin T test was also negative in all cases at baseline and at 6, 12, and 24 h after cardioversion. CONCLUSION: We conclude that the absence of elevations in CPK-MB levels and cardiac troponin T levels matched clinical and electrocardiographic results showing absence of myocardial damage after electrical cardioversion.

Aged↗
PubMed1997

Genetic determination of polygalacturonase production in wild-type and laboratory strains of Saccharomyces cerevisiae.

The genetic determination of polygalacturonase (PG) production in Saccharomyces cerevisiae was studied by biochemical and classical genetic techniques. Crosses of PG+ strains with PG- strains showed that in the haploid wild-type-derived strain, two structural genes were involved in the production of a hydrolysis halo on plates with polygalacturonic acid. However, in the case of PG+ laboratory strain IM1-8b, the phenotype was controlled by only one structural gene although the analysis of PG- IM1-8b mutants demonstrated the existence of at least two complementation groups. All these genetic results were assessed biochemically by means of cation-exchange chromatography. Two enzymes were separated in the wild-type strain, and only one in the laboratory strain. The three enzymes had different Km values, molecular masses, and optimal pHs for activity.

Crosses, Genetic↗