Electrospinning of poly(lactic acid)/polyhedral oligomeric silsesquioxane nanocomposites and their potential in chondrogenic tissue regeneration.

The study was conducted to evaluate the cytocompatibility and hydrolytic degradability of the new poly(lactic acid)/polyethylene glycol-polyhedral oligomeric silsesquioxane (peg-POSS/PLLA) nanocomposite as potential material for cartilage regeneration. PLLA scaffolds containing 0 to 5% of peg-POSS were fabricated by electrospinning. Human mesenchymal stem cells (hMSC's) were cultured in vitro to evaluate the cytocompatibility of the new nanocomposite material. Hydrolytic degradation studies were also carried out to analyze the mass loss rate of the nanocomposites through time. The addition of the peg-POSS to the PLLA did not affect the processability of the nanocomposite by electrospinning. It was also observed that peg-POSS did not show any relevant change in fibers morphology, concluding that it was well dispersed. However, addition of peg-POSS caused noticeable decrease in mean fiber diameter, which made the specific surface area of the scaffold to rise. hMSC's were able to attach, to proliferate, and to differentiate into chondrocytes in a similar way onto the different types of electrospun peg-POSS/PLLA and pure PLLA scaffolds, showing that the peg-POSS as nano-additive does not exhibit any cytotoxicity. The hydrolytic degradation rate of the material was lower when peg-POSS was added, showing a higher durability of the nanocomposites through time. Results demonstrate that the addition of peg-POSS to the PLLA scaffolds does not affect its cytocompatibility to obtain hyaline cartilage from hMSC's.

[Invasive gastroenteritis, anything new?]. / Gastroenteritis invasivas, ¿algo nuevo?

Invasive gastroenteritis is characterized by fever and inflammatory diarrhea and can be caused by nontyphoideal Salmonella serotypes and Shigella spp.-enteroinvasive Escherichia coli (EIEC), among other pathogens. This review describes emerging monophasic variants of Salmonella enterica serotype 1,4,[5],12:i:- and provides an evolutionary consideration of Shigella spp.-EIEC as a single pathotype. In 1997, a monophasic variant of S. enterica serotype 1,4,[5],12:i:-, phage-type U302, multidrug resistant (ACGSSuTSxT), lacking the fljBA operon, appeared in Spain constituting a "Spanish" clonal line. Subsequently, strains of S. 4[5],12:i:-, of different phage types with a new resistance genomic island (ASSuT) were detected in Italy, forming part of a European clonal line. Finally, an "American" clonal line with a deletion of fljBA different from the Spanish clonal line appeared. Therefore, probably by convergent evolution, different clonal lines of Salmonella 1,4,[5],12:i:-, which can carry resistance genes on chromosomes or plasmids, with Salmonella Typhimurium as ancestor, have emerged in the world. Although Shigella belongs to the E. coli species and despite the biological inconsistency involved, this genus has traditionally been considered to cause bacillary dysentery. The EIEC group shares virulence mechanisms and clinical manifestations with Shigella. Both lack some metabolic genes and harbor similar plasmids of invasion. Shigella spp. and EIEC evolved from independent clonal lines of E. coli, by horizontal acquisition of virulence factors, forming a single pathotype. IpaH gene detection is an alternative to attribute the corresponding pathogenic role to non-agglutinable strains that are biochemically compatible with Shigella spp.

Molecular analysis of hereditary hyperferritinemia-cataract syndrome in a large Basque family.

Hereditary hyperferritinemia-cataract syndrome is a genetic condition characterized by constitutively increased serum ferritin values in the absence of iron overload and by bilateral cataract. It has been demonstrated that mutations in the stem loop structure of the iron regulatory element (IRE) located in the 5'-untranslated region of the ferritin L-subunit gene (19q13.1) are responsible for the anomalous expression of this protein. Although not clearly explained, cataract formation seems secondary to the increased levels of ferritin in the lens. We analyzed a large Basque family in order to identify possible germline alterations of the iron regulatory element of the ferritin-L gene in affected individuals and first-degree relatives. All members of the family presented hyperferritinemia and cataract except a young child who had hyperferritinemia but did not present cataract. Sequence analysis permitted the identification of an A40-->G mutation in all members, including this child. This could demonstrate that cataract formation is a consequence of ferritin accumulation in the lens.

[Surgical treatment of partial anomalous pulmonary venous drainage]. / Cirugía del drenaje anómalo parcial de las venas pulmonares.

OBJECTIVES: We studied all patients operated for partial anomalous pulmonary venous drainage and half-time follow-up. MATERIALS AND METHODS: Twenty-eight patients with a mean age of 5 +/- 5 years (5 patients were less than 1 year old). There were sixteen male and twelve female patients. Thirteen patients were symptomatic (47%). The drainage was to the superior vena cava in thirteen cases, to the inferior vena cava in eight cases, to the right atrium in five cases, mixed (to the superior vena cava and to the inferior vena cava) in one case and to the innominate vein in one patient. The diagnosis was made through echocardiography and catheterization in 25 patients, whereas nuclear magnetic resonance was performed in the last five patients. All cases were corrected through medium thoracotomy, except for the single case in which the drainage was to the innominate vein). In 27 patients, the pulmonary veins were guided to the left atrium through an enlarged present atrial septal defect or through a created atrial septal defect. In one case a direct connection was performed from the veins to the left atrium. After the surgical correction, all patients underwent a color-coded Doppler echocardiography study and a nuclear magnetic resonance study was performed in five patients. RESULTS: Twenty-seven patients survived after surgical correction. The patient with a mixed drainage developed an obstruction of the superior vena cava, the pressure gradient was 9 mmHg. He required a second surgical procedure followed with angioplasty on two occasions during a six month period. Two patients showed an ectopic atrial rhythm at some late time. The patient who died was one month old and had an associated pulmonary parenchymal sequestration. CONCLUSION: Partial anomalous venous connection is a congenital heart disease which has an easy surgical correction. Complications may arise after the surgical correction, among them obstruction of the superior vena cava and arrythmias are most frequently found. Obstruction is present when 50% of the caval area is occupied by the patch. The arrythmias occur following all surgical techniques. In order to decrease the arrythmias it is necessary to perform a good hemosthasis at the site of the patch, to leave the sinus node free of compression and to perform the atrial incision at the posterior wall. The diagnosis and the follow-up can be performed with non-invasive procedures.

[The usefulness of two-dimensional echocardiography in the diagnosis of an interventricular aneurysm]. / Utilidad de la ecocardiografía bidimensional para el diagnóstico del aneurisma del septo interventricular.

The ventricular septal defect (VSD) may close spontaneously in the first few years of life. The closure occurs by muscle's growth of the borders of the defect or by the appearance of an aneurysm of ventricular septum composed mostly by tricuspid tissue. We believe that the two-dimensional echocardiography is the best method to determine the mechanisms that take part in the aneurysm formation. The study was carried out on 58 patients with aneurysms of ventricular septum observed in 230 patients with ventricular septal defects. 29 were male and 29 were female patients. The mean age at the time of diagnosis of aneurysm was 30 months (range 1 month-13 years). Forty seven patients had a perimembranous ventricular septal defect (perimembranous inlet 29, perimembranous trabecular nine, perimembranous outlet nine and of mixed's type seven), muscular defect nine (muscular inlet seven, and muscular trabecular two) and VSD closed in two. The size of the defect was 0.47 +/- 0.2 cm (range 0.2-1.1). In 16 the defect was larger than 0.6 cm. Thirty two patients had associated anomalies. On study the aneurysm in relation with tricuspid valve leaflets: in 27 cases (46.3%), the aneurysm was entirely formed by tricuspid septal leaflets tissue (17 had perimembranous ventricular septal defect and seven muscular), in eight (13.6) the aneurysm had tricuspid valve leaflets and interventricular component of the membranous septum tissue (five perimembranous defect and two muscular) and in another 16 cases membranous septum tissue only. In 7 patients the origin of the aneurysm wasn't confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cardiovascular pathology in Marfan syndrome. Study of 11 children using two-dimensional echocardiography]. / Patología cardiovascular en el síndrome de Marfan. Estudio de 11 niños con ecocardiografía bidimensional.

UNLABELLED: From 1983 to 1987 we have studied by two-dimensional echocardiography 11 pediatric patients with Marfan's syndrome. All of them presented cardiovascular lesions localized mainly in the aortic and mitral valves and in the ascending aorta. Nine patients had a dilated aortic ring in both transversal and longitudinal diameters 2.03 and 2.29 cm/m2 of body surface (bs), respectively. The average value of the aortic valvular area was 4.71 cm2/m2 bs. The 9 patients presented also dilatation of the ascending aorta (2.01 cm/cm2 bs). There was thickening of the mitral valve in 5 cases and a prolapse was present in 8 (73%). In 4 cases the prolapse was localized in anterior leaflet valve in 2 in the posterior and in 2 in both. The maximal mitral valve diastolic area was 3.25 cm2/m2 bs. None of them has needed during follow up valvular replacement. Considering the importance of this cardiovascular disease and knowing its unpredictable evolution we recommend, in the absence of valvular insufficiency, and annual echocardiographic reevaluation, and more often if valvular insufficiency is already present. IN CONCLUSION: two-dimensional echocardiographic is useful and necessary for the diagnosis and follow up of patients with Marfan's syndrome.