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Biomedical subjects

M Marco

Publications and source records attributed to M Marco.

At least 19 recordsLinked to original sources
PubMed2006

A relevant enzyme in granulomatous reaction, active matrix metalloproteinase-9, found in bovine Echinococcus granulosus hydatid cyst wall and fluid.

In addition to the ability of matrix metalloproteinases (MMP) to degrade components of the extracellular matrix and their involvement in pathology-related processes of tissue remodeling, they were recently reported to enhance inflammation by activation of proinflammatory cytokines, or their release from the cell surface. In the work reported here, proteolytic activity previously found for hydatid cysts was further characterized as MMP-9. Active host MMP-9 was found in walls and fluids of bovine hydatid cysts of Echinococcus granulosus in the environment of granulomatous reaction. Pooled walls and fluids of hydatid cysts obtained from infected cattle were processed. Strong proteolytic activity was detected by zymography. The proteolytic fraction was purified by anion exchange and gelatin-agarose affinity chromatography. Major proteinases of the purified fraction were subjected to mass spectrometry and their identities were further confirmed by Western blotting using commercial anti-human MMP-9 monoclonal antibodies. Two proteinases were characterized as latent and active forms of host MMP-9. Using the same antibody for immunoblot, activity was localized, in paraffin-embedded sections of the parasite and the local host environment, to epithelioid and giant multinucleated cells. It is proposed here that MMP-9 is secreted by specialized host cells of monocytic lineage (epithelioid/giant cells) as an effector, in an attempt to digest the persistent foreign body. In vivo activation of MMP-9 suggests its involvement in inflammatory reaction and in the chemotaxis of inflammatory cells to the cyst. However, E. granulosus can deal efficiently with MMP-9. Research is suggested into possible immune evasion mechanisms, including the secretion of an inhibitory molecule.

Amino Acid Sequence↗
PubMed2003

Effect of sperm preparation method on in vitro fertilization in pigs.

This study was designed to determine the effect of different sperm preparation treatments before IVF on the acrosome reaction, oocyte penetration time, early embryo development and timing of female and male pronucleus formation. Pooled sperm-rich fractions were (i) washed in PBS, (ii) left unwashed, or (iii) layered in a Percoll gradient. In Expt 1, the proportion of acrosome-reacted spermatozoa, determined by staining with fluorescein isothyocyanate-labelled peanut agglutinin lectin and propidium iodide, was highest after treatment with Percoll (P < 0.001). In Expt 2, oocytes matured in vitro were co-cultured with spermatozoa for 2, 4 or 6 h. Attached spermatozoa were then removed and the oocytes were cultured in fresh IVF medium for 16 h. Both sperm treatment and co-culture time were found to affect penetrability and monospermy rates (P < 0.001); spermatozoa treated with Percoll showed fastest oocyte penetration and highest penetrability. In Expt 3, matured oocytes were co-incubated with spermatozoa pretreated by the three above mentioned procedures (i, ii, iii) for 2, 6 and 2 h respectively. Putative zygotes were then washed and transferred to medium NCSU-23 until the blastocyst stage. In this experiment, sperm treatment had a significant effect on the cleavage rate (P < 0.001) and rate of blastocyst formation (P < 0.05); the group treated with Percoll showed the highest rate of blastocyst formation. Finally, in Expt 4, timing of female and male pronucleus formation for each sperm treatment was determined 4, 6 and 8 h after insemination. The time of female and male pronucleus formation was affected by the sperm treatment and was faster for the Percoll group (P < 0.05). The findings of the present study indicate that treatment with Percoll yields the best results in this in vitro pig embryo production system.

Acrosome Reaction↗
PubMed2002

Antidisialosyl antibodies in chronic idiopathic ataxic neuropathy.

Antidisialosyl antibodies were found in two out of 13 patients with chronic idiopathic ataxic neuropathy (CIAN) and not in 32 patients with different sensory neuropathies of known cause. This finding confirms the association of antidisialosyl antibodies and CIAN regardless of the absence of the M band. These antibodies may have pathogenic relevance; however, larger series are needed to establish their clinical significance.

Aged↗
PubMed2002

Biochemical and molecular studies in 26 Spanish patients with congenital disorder of glycosylation type Ia.

We present our experience with the diagnosis of 26 patients (19 families) with congenital disorders of glycosylation classified as type Ia due to PMM deficiency. In all but one of these CDG Ia families the patients are compound heterozygous for mutations in PMM2. Eighteen different mutations were detected. In contrast to other series in which R141H represents 43-50% of the alleles, only 9/36 (25%) alleles have this mutation. Two mutations (R123Q and T237M) have been found on three disease chromosomes, four (V44A, Y64C, P113L and F207S) on two disease chromosomes and 12 mutations (D65Y, Y76C, IVS3+2C>T, E93A, R123X, V129M, I153T, F157S, E197A, N216I, T226S, C241S) only on one disease chromosome. V44A and D65Y probably originated in the Iberian peninsula, as they have only been reported in Portuguese and Latin-American patients; Y64C, Y76C, R123X and F207S have not been detected in other patients. R123X is the only stop codon mutation so far described in PMM2. The common European F119L mutation has not been found in our patients, although it is very frequent in other populations (43% allele frequency in Danish patients). Probably because of this genetic heterogeneity, Spanish patients show very diverse phenotypes that are, in general, milder than in other series. This points to the necessity of widening the criteria for CDG in the routine screening for inborn metabolic diseases.

Carbohydrate Metabolism, Inborn Errors↗
PubMed2000

Conditional gene expression in the epidermis of transgenic mice using the tetracycline-regulated transactivators tTA and rTA linked to the keratin 5 promoter.

To produce conditional expression of genes in the mouse epidermis we have generated transgenic mouse lines in which the tetracycline-regulated transcriptional transactivators, tTA and rTA, are linked to the bovine keratin 5 promoter. The transactivator lines were crossed with the tetOlacZ indicator line to test for transactivation in vivo. In the absence of doxycycline, the K5/tTA line induced beta-galactosidase enzyme activity in the epidermis at a level 500-fold higher than controls, and oral and topical doxycycline caused a dose- and time-dependent suppression of beta-galactosidase mRNA levels and enzyme activity. In the K5/rTA lines, doxycycline induced beta-galactosidase activity between 3- and 50-fold higher depending on the founder line, and this occurred within 24-48 h after dosing. Histochemical analysis of all lines localized beta-galactosidase expression to the basal layer of the epidermis and the outer root sheath of the hair follicle, as well as other keratin 5 positive tissues. In several K5/rTA lines, skin-specific transactivation was restricted to the hair follicle. Treatment of these double transgenic mice with 12-O-tetradecanoyl-phorbol-13-acetate caused rapid migration of beta-galactosidase marked cells from the hair follicle through the interfollicular epidermis, demonstrating the usefulness of this specific double transgenic for fate mapping cells in the epidermis. These results show that the tetracycline regulatory system produces effective conditional gene expression in the mouse epidermis, and suggest that it should be amenable to suppression and activation of foreign genes during development and specific pathologic conditions relevant to the epidermis.

Animals↗
PubMed1998

Fc-binding molecules specific for human IgG1 and IgG3 are present in Echinococcus granulosus protoscoleces.

In this work we describe the presence of Fc-binding activity on the suckers and tegument of E. granulosus protoscoleces. A fraction (PSA-Fc+) from protoscolex somatic antigens was isolated by affinity chromatography on human Fc-gamma1-Sepharose. Analysis by SDS-PAGE of PSA-Fc+ showed that it contained two major components. Using mouse F(ab')2-human Fc chimaeric monoclonal antibodies we verified that PSA-Fc+ bound mainly to human Fc-gamma1 and Fc-gamma3 isotypes. In addition, one of the components of PSA-Fc+ showed proteolytic activity. Both, Fc-binding and proteolytic activities localized on the protoscolex surface, may play a relevant role in the host-parasite interaction.

Animals↗
PubMed1997

Putative association of a mutant ROM1 allele with retinitis pigmentosa.

Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous form of retinal degeneration. Several genes and loci have been shown to be involved in the disease, although each of them only accounts for a few cases. Mutations in the gene encoding ROM1, a rod-specific protein, have been putatively associated with several forms of RP. Here we describe a double-mutant allele of this gene, P60T and T108M, present in two affected sibs and also in two healthy members of a Spanish RP family. The same double-mutant allele was previously considered to be responsible for autosomal dominant RP in one family. We now report data that question the potential pathogenicity of these two ROM1 mutations.

Adolescent↗
PubMed1997

Evaluation of cerebral function after carotid endarterectomy.

Neuroimaging methods have failed to disclose correlation between degree of cerebral atrophy and blood flow in carotid artery stenosis patients. Moreover, intellectual improvement after carotid endarterectomy does not correlate fully with neuroimaging data in such patients. We performed brain electrical activity mapping and psychological testing before and 4 weeks after operation in 28 patients with symptomatic, high-grade, carotid stenosis. Postoperatively, electroencephalographic (EEG) mean frequency and absolute theta power improved significantly (p < 0.01). Mean frequency increased >1 Hz in most areas while power decreased dramatically, mainly because of resolution of high-voltage foci in 8 patients. Differences were conspicuous in both frontal lobes irrespective of the operated side, which suggests changes in perfusion affecting the whole brain. This is a positive effect of endarterectomy. Mini-Mental test and Set Test for verbal fluency had a positive correlation with the qEEG changes. Quantitative EEG as a measure of cerebral function has disclosed discriminative improvement in the early postoperative period. Our results support the thesis of improvement subsequent to endarterectomy.

Adolescent↗
PubMed1997

[Spontaneous acquired localized neuropathies in childhood].

Acquired non-surgical, non-traumatic localized neuropathies, excluding cranial nerve disorders, are rare in infancy. We review the clinical histories of six children, studied for this disorders amongst a total of 2,105 children seen in the Neuropediatric Department of the Hospital Miguel Servet in Zaragoza. Two were diagnosed as familial neuropathy with pressure sensitive paralysis. Two plexopathies were considered to be familial brachial plexopathy with minor dysmorphic features. One case was diagnosed as idiopathic radial neuropathy and a further case as idiopathic lumbosacral plexopathy. We emphasize that although rare in pediatrics, spontaneous localized neuropathies often show constitutional pathology, frequently hereditary. Idiophatic cases may also be hereditary, and it may be difficult to confirm the diagnosis if there is no family history or phenotypic characteristics. Diagnosis depends on the personal and family history, physical examination, neurophysiological study, absence of abnormal neuroimaging findings and awareness of the possibility of this diagnosis. These disorders probably occur more often than is generally believed.

Brachial Plexus↗
PubMed1996

Clinical and genetic aspects of two Spanish families with autosomal dominant retinitis pigmentosa (ADRP)

A study was made of two families with autosomal dominant retinitis pigmentosa (ADRP) from Valencia (Spain). One family (ADRP15) was found to have mutation in codon 114 of the rhodopsin gene that led to a substitution of a glycine for an aspartic acid. The second family (ADRP7) substituted an aspartic acid for valine in codon 173 of the peripherin-RDS gene. Rhodopsin is involved in 25% of ADRP cases and many mutations of this gene have been described as causing different forms of the disease, with variable severity and age at onset. ADRP has been classified as RP with a milder symptom evolution, a typical RP fundus pattern, and macular involvement occurring after the second decade of life. Peripherin-RDS gene mutations lead to RP or other retinopathies. Furthermore, two mutations in codon 172 have been described as causing macular dystrophy. In ADRP7, a mutation in neighboring codon 173 produced RP with an atypical fundus pattern and macular involvement within the first decade of life. These observations confirm the established clinical and genetic heterogeneity involved in this form of RP.

Adolescent↗
PubMed1994

Inhibition of histone/anti-histone reactivity by histone-binding serum components; differential effect on anti-H1 versus anti-H2B antibodies.

IgG fractions were purified on a protein G-agarose column from sera of both systemic lupus erythematosus (SLE) patients and healthy donors. All IgG fractions, after elution with 0.5 M acetic acid, reacted with histones in an anti-histone ELISA assay, and IgG anti-histone activity was in all instances higher in the IgG fraction than in the corresponding whole serum. This was shown to be due to the presence in serum of histone-binding components that inhibited IgG binding to histones. Both normal human and SLE patients' sera had these histone-binding components, and disparity between serum-positive and -negative anti-histone antibody (AHA) tests was not dependent on differences in the blocking capacity but on IgG antibody levels and avidity. Interaction of normal serum IgG fraction with all five histones was of low avidity, whereas interaction of IgG from AHA-positive SLE sera with both H1 and H2B had high avidity. Low-affinity antibodies to every histone fraction, but also high-affinity anti-H1 antibodies, were preferentially inhibited. Our data indicate that several serum protein components are inhibiting histone/anti-histone interaction and may play a protective role against both high-affinity anti-H1 antibodies present in SLE patients, and natural, low-affinity, anti-histone antibodies. As some acute phase proteins, notably C-reactive protein, bind to histones, it is conceivable that they play such a role. High-affinity anti-H2B antibodies, present in some SLE patients, and not inhibited by these serum components, may, on the other hand, participate in the pathogenesis of the disease.

Antibody Affinity↗