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Biomedical subjects

A Mínguez

Publications and source records attributed to A Mínguez.

9 recordsLinked to original sources

Dinoflagellates have a eukaryotic nuclear matrix with lamin-like proteins and topoisomerase II.

Unicellular Dinoflagellates represent the only eukaryotic Phylum lacking histones and nucleosomes. To investigate whether Dinoflagellates do have a nuclear matrix that would modulate the supramolecular organization of their non-nucleosomal DNA and chromosomes, cells of the free-living unarmored Dinoflagellate Amphidinium carterae were encapsulated in agarose microbeads and submitted to sequential extraction with non-ionic detergents, nucleases and 2 M NaCl. Our results demonstrate that this species has a residual nuclear matrix similar to that of vertebrates and higher plants. The cytoskeleton-nuclear matrix complex of A. carterae shows a relatively intricate polypeptide pattern. Immunoblots with different antibodies reveal several intermediate filament types of proteins, one of which is immunologically related to vertebrate lamins, confirming that these proteins are ancestral members of the IF family, which is highly conserved in eukaryotes. A topoisomerase II homologue has also been identified in the nuclear matrix, suggesting that these structures could play a role in organizing the Dinoflagellate DNA in loop domains. Taken together our results demonstrate that the nuclear matrix is an early acquisition of the eukaryotic nucleus, independent of histones and nucleosomes in such a way that the mechanisms controlling the two levels of organization in eukaryotic chromatin would be molecularly and evolutionarily independent.

Animals

[Post-traumatic cholelithiasis].

A 5 year old patient, without any lithogenic antecedent, suffered a trauma, resulting in a shrunken fracture of the left parietal bone, and a splenic parenchymal hematoma. A hemoperitoneum developed at the 3rd postoperation day, with an overall blood loss of 15% of the total blood volume. At the 6th day a well formed biliary calculi was detected in the gallbladder. As the patient remain asymptomatic related to his cholelithiasis, an ultrasound follow-up was instituted. At 3 month postinjury all biliary stones dissolved completely. In this report, the etiopathogenic factors responsible of stone formation in the biliary tree, and current therapeutic recommendations are reviewed.

Child, Preschool

Immunological characterization of lamins in the nuclear matrix of onion cells.

We have used polyclonal and monoclonal antibodies against different lamins from vertebrates, and the IFA antibody recognizing all kinds of intermediate filament proteins, to investigate the lamins of the nuclear matrix of Allium cepa meristematic root cells. All the antibodies react in the onion nuclear matrix with bands in the range of 60-65 kDa, which are enriched in the nuclear matrix after urea extraction, and do not crossreact with other antibodies recognizing intermediate filaments in plants (AFB, anti-vimentin and MAC 322), ruling out crossreaction with contaminating intermediate filaments of cytoplasmic bundles. In 2-D blots the chicken anti-lamin serum reacts with one spot at 65 kDa and pI 6.8 and the anti B-type lamin antibodies with another one at 64 kDa and pI 5.75. Both crossreact with IFA. The lamin is localized at the nuclear periphery and the lamina by indirect immunofluorescence. Immunogold labelling of nuclear matrix sections reveals that the protein is not only associated with the lamina, but also with the internal matrix. Taken together these results reveal that higher plants, which do not possess an organized network of cytoplasmic intermediate filaments, nevertheless present a well-organized lamina containing lamins in which at least one of them is immunologically related to vertebrate lamin B. Our data confirm that lamins are very old members of the intermediate filament proteins that have been better conserved in plants during evolution than their cytoplasmic counterparts.

Allium

Ribonucleoprotein components of root meristematic cell nuclei of the tomato characterized by application of mild loosening and immunocytochemistry.

Immunocytochemistry and hypotonic-formaldehyde fixation have been used to study the extranucleolar ribonucleoprotein (RNP) constituents of the nucleus of tomato root meristematic cells. The study of the distribution of small nuclear uridine-rich RNPs (snRNP) by means of a monoclonal anti-Sm antibody recognizing a 29-kDa protein in plants, after standard fixation, shows a preferential labeling of the perichromatin region and a lower labeling of the interchromatin space. These results suggest that in the tomato there is a perichromatin region similar to that of animal cells, in which much of the nonnucleolar transcription and splicing takes place. In hypotonic-formaldehyde-detergent-fixed nuclei, fibrogranular polyparticles have been visualized reacting with anti-snRNP antibody. These structures are frequently associated with filaments of extended chromatin characterized by their reaction with an anti-DNA monoclonal antibody.

Antibodies, Antinuclear

[A parametric description of the parenteral nutrition protocols of 19 American hospitals].

In the preparation of a centralized parenteral nutrition unit project in our hospital, following the creation of a multi-disciplinary commission entrusted with the study of this project, we proceeded to evaluate parenteral nutrition protocols of national and foreign hospitals, as a first approach to the subject. This study evaluates and extracts the data we consider most relevant in a sample of 19 American hospitals. With regard to the types of parenteral diet, we observed that most of them (63%) had "standard diets", mainly formulated with 25% glucose and 4.25% crystalline amino acids. None of the protocols studied contained alternatives to glucose as a calorie-contributor, nor were there special formulae for amino acids, although many of them included it in their therapies for use if considered necessary. In all protocols, the contribution of fats was reduced to concrete situations and administered in a different way to the rest of the food in 73% of cases. With regard to additives, despite the existence of standard formulations of electrolytes and vitamins and oligoelements, in 100% of the hospitals studied, there was the possibility of formulating each element separately. Administration was done in several doses per day in 42% of cases and in 100%, using perfusion pumps. The data obtained from this review was of great value in preparing our own parenteral nutrition protocols.

Canada

[Association of dystrophinopathy with facial-scapular-humeral dystrophy in the same family].

We present the association of a distrophinopathy with a case of facioscupulohumeral dystrophy in two individuals belonging to the same family. The discrepancy in the seric creatinphosphokinase (CPK) of the two patients together with certain clinical data suggests the possibility that it is a question of two different processes. This impression was confirmed later through dystrophine analysis and genetic examination techniques. This case drew attention to the vital need today to insist on a combination of genetic examinations and dystrophine analysis when diagnosing muscular dystrophies, thus avoiding mistakes derived from diagnostic assumptions made on the basis of antecedents in the family involving neuromuscular disorders and the consequences that this might have regarding vital prognosis and advice to the family. This is the first case of coincidental association of these two processes within one family that has so far come to our knowledge.

Antibodies, Monoclonal

[Four new cases and a review of the literature concerning the migraine with csf pleocytosis syndrome].

The syndrome known as migraine with cerebrospinal fluid (CSF) pleocytosis is a clinical syndrome of controversial pathogenesis characterized by typical migraine headaches occurring in a fixed period of time along with lymphocyte pleocytosis in CSF which persists during intercritical periods. We present four new cases of this syndrome diagnosed in our service and we review those cases published in the literature in which there were no personal headache antecedents, attempting in this way to separate this syndrome from other types of migraine as included in the present classification. There also exists the possibility that it might be a question of a secondary process, the pathogenesis of which may play a part in the activation of the humoral immune system, given the frequent existence of immunogenic antecedents the previous days as well as that of a humoral reaction expressed as an increase in IgG levels in CSF with normal blood electrophoresis.

Humans