Embarazo y síndrome de Evans: a propósito de un caso / Pregnancy and Evans'syndrome: case report

El síndrome de Evans es la coexistencia de trombocitopenia autoinmune con anemia hemolítica autoinmune. Raramente se presenta durante el curso de un embarazo. Esto dificulta las opciones terapéuticas, dado que algunos de los agentes utilizados para el tratamiento son teratogénicos. Los efectos del síndrome de Evans en el feto y recién nacido se desconocen dado el escaso número de casos publicados. Presentamos el caso de una paciente con diagnóstico preconcepcional de síndrome de Evans, que presenta una crisis hemolítica en el curso de una gestación, y diagnóstico de restricción del crecimiento intrauterino (RCIU), en tratamiento en la Clínica Ginecotocológica "A" del Centro Hospitalario Pereira Rossell (CHPR), de Montevideo, Uruguay. Se analizan opciones terapéuticas y evolución, así como publicaciones previas...

Evans' syndrome is the coexistence of autoimmune thrombocytopenia with autoimmune hemolytic anemia. It is rarely found during the course of a pregnancy. This makes treatment options more difficult, since some therapeutic drugs are teratogenic. The effects of Evans' syndrome in the fetus and newborn are unknown given the low number of reported cases. We report the case of a patient with preconceptional diagnosis of Evans' syndrome, who develops a hemolytic crisis during the course of a pregnancy, and diagnosis of intrauterine growth restriction (IUGR), treated at Clinica Ginecotocologica "A" at the Pereira Rossell Hospital Center, in Montevideo, Uruguay. Treatment options and evolution are analyzed, as well as previous reports...

Overexpression of Ipe protein from the coliphage mEp021 induces pleiotropic effects involving haemolysis by HlyE-containing vesicles and cell death.

Lysogenic Escherichia coli K-12 harbouring the prophage mEp021 displays haemolytic activity. From a genomic library of mEp021, we identified an open reading frame (ORF 4) that was responsible for the haemolytic activity. However, the ORF 4 sequence contains four initiation codons in the same frame: ORF 4.1-ORF 4.4, coding for 83-a.a., 82-a.a., 77-a.a. and 72-a.a. products, respectively. The expression of the cloned ORF 4.3, or inducer of pleiotropic effects (ipe), reproduced the haemolytic phenotype in a native strain carrying the gene hlyE(+), but not in the mutant hlyE(-) strain. The overexpression of Ipe induced several pleiotropic effects, such as the inhibition of cell growth and the deregulation of cell division, which resulted in a mixture of normal and desiccated-like cells: normal-filamentous, desiccated-like-filamentous bacilli, minicells etc. Other effects included abnormalities of the cell membrane, the production of vesicles containing HlyE, and finally, cell death. These events were analysed at the molecular level by microarray assays. The global transcription profile of E. coli K-12 strain MC4100, which expressed Ipe after 4 h, revealed differential expression of various genes, most of which were related either to cell membrane and murein biosynthesis or to cell division. The up-regulation of some of these transcripts was confirmed by qRT-PCR. Additional research is needed to determine whether these effects are directly related to Ipe activity or are consequences of the cellular responses to putative structural damage induced by Ipe.

Characterization of heme as activator of Toll-like receptor 4.

Heme is an ancient and ubiquitous molecule present in organisms of all kingdoms, composed of an atom of iron linked to four ligand groups of porphyrin. A high amount of free heme, a potential amplifier of the inflammatory response, is a characteristic feature of diseases with increased hemolysis or extensive cell damage. Here we demonstrate that heme, but not its analogs/precursors, induced tumor necrosis factor-alpha (TNF-alpha) secretion by macrophages dependently on MyD88, TLR4, and CD14. The activation of TLR4 by heme is exquisitely strict, requiring its coordinated iron and the vinyl groups of the porphyrin ring. Signaling of heme through TLR4 depended on an interaction distinct from the one established between TLR4 and lipopolysaccharide (LPS) since anti-TLR4/MD2 antibody or a lipid A antagonist inhibited LPS-induced TNF-alpha secretion but not heme activity. Conversely, protoporphyrin IX antagonized heme without affecting LPS-induced activation. Moreover, heme induced TNF-alpha and keratinocyte chemokine but was ineffective to induce interleukin-6, interleukin-12, and interferon-inducible protein-10 secretion or co-stimulatory molecule expression. These findings support the concept that the broad ligand specificity of TLR4 and the different activation profiles might in part reside in its ability to recognize different ligands in different binding sites. Finally, heme induced oxidative burst, neutrophil recruitment, and heme oxygenase-1 expression independently of TLR4. Thus, our results presented here reveal a previous unrecognized role of heme as an extracellular signaling molecule that affects the innate immune response through a receptor-mediated mechanism.

Antimicrobial susceptibility, hemolysis, and hemagglutination among aeromonas ssp. isolated from water of a bovine abattoir

The presence of Aeromonas ssp. in food has been demonstrated. They are often introduced from water, which is the natural habitat of many species and is thought to be the main source of contamination. The occurrence of Aeromonas ssp. was investigated in 70 water samples of a bovine abattoir. Aeromonas ssp. were present in 21.4(per cent) of water samples. A.hydrophila was isolated from 11.4(per cent) of supplying water samples and from 25.7(per cent) of the water drained from carcasses, whereas A. sobria was sole isolated from 5.7(per cent) of supplying water samples. Although greater number of positive samples were from water drained from carcasses, only A.hydrophila isolates were present. This suggests that the supplying water is the source of contamination. The antibiotic susceptibility testing revealed all strains were resistant to ß-lactam antibiotics. However, the susceptibility to other antimicrobials was variable, being A.hydrophila more resistant than A. sobria strains. The investigation for virulence factors revealed positive reactions of hemolysis and hemagglutination. The results indicate that Aeromonas ssp. are present in the supplying water system. These microorganisms may be a potential contaminant of carcasses and widespread in derived food.

Phenotypic stability and plasmid detection in Actinobacillus actinomycetemcomitans

Neste estudo foram avaliadas a estabalidade da atividade hemolítica, a resistência a antibióticos e a detecção de plasmídios em cepas orais de A. actinomycetemcomitans. As características foram estßveis durante os diferentes repiques sucessivos realizados nas condições de nosso experimento. Todos os isolados de A. actinomycetemcomitans testados, perderam ou mudaram algums características fenotípicas tal como morfologia colonial e o crescimento em meio líquido.

Phenotypic stability and plasmid detection in Actinobacillus actinomycetemcomitans.

The stability of hemolytic activity, antibiotic resistance and plasmid detection in Actinobacillus actinomycetemcomitans isolates were studied. These characteristics were stable for all experimental conditions. All tested isolates lost or changed some phenotypic characteristics such as colonial morphology and growth in liquid medium.

Functional consequences of the genetic polymorphism of the third component of complement.

The third component of complement, the central protein of the complement cascade, occurs in two principal allotypes, C3S and C3F. An excess frequency of the F allotype has been implicated in a number of disease states, including some forms of glomerulonephritis. These associations have been explained by functional differences between C3S and C3F. We examined several complement functions, using purified preparations of C3S or C3F. The C3S allotype was 1.3 times more efficient than C3F in a hemolytic assay employing sensitized sheep erythrocytes; this difference was shown to arise from a slightly more efficient deposition of C3F on the cell surface. These differences are trivial and of much less magnitude than the functional differences between C4A and C4B. There were no differences between allotypes in their ability to be converted to inactive C3b (C3bi) by complement factors H and I or by CR1 and factor I. No significant differences were seen between the allotypes and their ability to support solubilization of preformed immune complexes.

The hereditary haemolytic syndromes

A review is made of recent developments in the study of the hereditary haemolytic syndromes. Current concepts in the pathogenesis of haemolysis are briefly discussed and the various intrinsic haemolytic disorders classified, with particular reference to anaemias due to red cell defects. The hereditary haemolytic syndromes are discussed in detail, as regards to both their genetic interrelationship and the recent demonstration of abnormal haemoglobin moieties in sickle cell trait and anaemia, and in haemoglobin C. disease. Reference is made to the recent application of paper electrophoretic analysis to the identification of these abnormal haemoglobins. Whilst hereditary sphercytosis and the thalassaemia syndromes are but rarely seen in the Caribbean area, the incidence of sickle cell trait is noted to vary between 5-12 percent of the mixed populations. Haemoglobin C. trait has been found to occur in 2 per cent of North American Negroes, so that these two anomalies alone or together may be present in a significant proportion of persons. Emphasis is placed on the potentiating effect which results from the linking of the dissimilar genes responsible for the hereditary haemolytic syndromes. The simultaneous occurrence of any one of these together with that determining the sickle cell trait is the probable cause of the so-called "mild" anaemia found to occur in those heterozygous children of whom one parent fails to show the sickling trait. It is stressed that while the hereditary haemolytic syndromes have many feature in common, the actual cause of red cell destruction varies with the shape to which the erythrocyte is ultimately changed (AU)