ABSTRACT
RESUMEN El quitosano (QT) es un biopolímero que ha sido ampliamente utilizado en aplicaciones de ingeniería de tejido óseo, demostrando un gran potencial para este propósito. El presente estudio tiene como objetivo desarrollar un sistema de hidrogel entrecruzable in situ, compuesto de quitosano y nano-partículas de hidroxiapatita (HAP), un equivalente al componente mineral del hueso. El quitosano fue modificado, utilizando reacciones de carbodiimida, con ácido lactobiónico y ácido azidobenzoico para hacerlo soluble a pH fisiológico y foto-entrecruzable, respectivamente. El quitosano modificado fue mezclado en diferentes proporciones con HAP, y luego de una corta exposición a luz UV, se formaron hidrogeles. Células madre mesenquimales de médula ósea de rata (MSC) fueron sembradas sobre estos hidrogeles y cultivadas por 4, 10 y 16 días, bajo condiciones osteogénicas y no-osteogénicas. A través de ensayos de proliferación celular, actividad de fosfatasa alcalina, y microscopía confocal, se observó que la mayoría de las formulaciones soportan la adhesión y proliferación celular, mostrando importantes interacciones célula-biomaterial, y una diferenciación osteogénica temprana destacada en las formulaciones 70:30 y 50:50, QT:HAP. Algunas formulaciones del sistema foto-entrecruzable tienen potencial en aplicaciones de ingeniería de tejido óseo, y se propone estudios más detallados de diferenciación celular.
ABSTRACT Chitosan (QT) is a biopolymer that has been used in widely used in bone tissue engineering applications, demonstrating great potential for that purpose. Therefore, the present study aims to develop an in situ crosslinking hydrogel system, composed of chitosan and hydroxyapatite (HAP). Briefly, chitosan was modified, using carbodiimide chemistry, with lactobionic and azidobenzoic acid to make it soluble at physiological pH and photo-crosslinkable, respectively. The modified chitosan was mixed with HAP, in different proportions, and later exposed to UV light, yielding hydrogels. Mesenchymal stem cells, from rat bone marrow, were seeded onto the hydrogels and cultured for 4, 10 and 16 days, under osteogenic and non-osteogenic conditions. Through cell proliferation and alkaline phosphatase activity assays, and confocal microscopy, it was observed that the majority of formulations supported cell adhesion and proliferation, and a significant early osteogenic differentiation in formulations 70:30 and 50:50, QT:HAP. According to these results, the proposed photo-crosslinking system has potential for tissue engineering applications, and further specific studies are proposed for cell differentiation.
ABSTRACT
Abnormalities in maternal folate and carbohydrate metabolism have both been shown to induce neural tube defects (NTD) in humans and animal models. However, the relationship between these two factors in the development of NTDs remains unclear. Data from mothers of children with spina bifida seen at the Unidad de Espina Bífida del Hospital Infantil Virgen del Rocío (case group) were compared to mothers of healthy children with no NTD (control group) who were randomly selected from patients seen at the outpatient ward in the same hospital. There were 25 individuals in the case group and 41 in the control group. Analysis of genotypes for the methylenetetrahydrofolate reductase (MTHFR) 677CT polymorphism in women with or without risk factors for abnormal carbohydrate metabolism revealed that mothers who were homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism were more likely to have offspring with spina bifida and high levels of homocysteine, compared to the control group. The increased incidence of NTDs in mothers homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism stresses the need for careful metabolic screening in pregnant women, and, if necessary, determination of the MTHFR 677CT genotype in those mothers at risk of developing abnormal carbohydrate metabolism.
Subject(s)
Carbohydrate Metabolism , Genotype , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Mothers , Neural Tube Defects/genetics , Neural Tube Defects/metabolism , Polymorphism, Single Nucleotide , Adult , Alleles , Case-Control Studies , Female , Genetic Association Studies , Homocysteine/blood , Humans , Incidence , Neural Tube Defects/epidemiology , Pregnancy , Risk Factors , Spinal Dysraphism/epidemiology , Spinal Dysraphism/genetics , Spinal Dysraphism/metabolism , Young AdultABSTRACT
UNLABELLED: The purpose of this study is to compare two patient cohorts with Bankart lesion, one with intraarticular drainage after surgery and another group without drainage. MATERIAL AND METHODS: We designed a study cohort for patients with Bankart repair due to relapsing shoulder dislocation; they underwent arthroscopy and were stabilized with suture anchors; intraarticular drainage was used in one group and no drainage was used in a control patient cohort. Thirty-one consecutive patients were operated by the same team. All patients were evaluated at the office using the Rowe, Constant and UCLA scales. The statistical tests used included chi-square, the student-t test or the Wilcoxon rank sum test (nonparametric version). RESULTS: The UCLA median value was 35 (34.5-35) in group B and 33 (32.5 -35) in group A, with p = 0.13. The Rowe test score was 100 (95;100) in group B and 100 in group A (85;100), with p = 0.913. The Constant test score was 96 (88.8-98) in group B and 96 (90.5-100) in group A with p = 0.535 and no differences. DISCUSSION: This comparative study includes two groups that underwent arthroscopic Bankart repair, one with drainage and another one without drainage. Good results were obtained in both groups. In this study the placement of a postoperative intraarticular drainage did not improve clinical results, as no statistically significant differences were observed between both groups.
Subject(s)
Postoperative Care/methods , Shoulder Dislocation/surgery , Shoulder Pain/diagnosis , Adult , Cohort Studies , Female , Humans , Male , Recurrence , Shoulder Dislocation/complications , Shoulder Pain/etiology , SuctionABSTRACT
Presenta un caso de Mielolipoma suprarrenal, tumor raramente descrito, endocrinológicamente benigno. Analizamos la presentación Clínica y Quirúrgica. Como revisión de la literatura.
Subject(s)
Female , Adult , Adrenal Glands , Carcinoma , Myelolipoma/surgery , Myelolipoma/therapy , Cancer Care Facilities , Ecuador , Medical Examination , Patients , Physical ExaminationABSTRACT
Se reporta un caso de tumor de Frantz (neoplasia papilar quistica del pácnreas), en una mujer de 23 años, a quien se laparotomizó encontrándo un tumor del cuerpo y cola pancreatica, con gran invasión local, no así linfática. Describimos la clínica, histológía e imagen de esta neoplasia, como el esfuerzo quirurgico del grupo de cirujanos, Logrando la radicalidad del tumor, ofreciendo de esta manera, a una pacientes jóven escelente sobrevida.
Subject(s)
Humans , Female , Adult , Carcinoma, Papillary/complications , Pancreas , Pancreatic CystABSTRACT
Serological studies were carried out using the haemagglutination inhibition and neutralization tests so as to know the circulation dynamics of some arboviruses with the use of Western and Eastern equine encephalitis antigens and St Louis encephalitis antigens in human serum from sound and symptomatic individuals, as well as from sentinel birds, between 1987 and 1991, and during 1994. 1.7% of the asymptomatic subjects tested presented neutralizing antibodies to to Eastern equine and 4.8% to St Louis encephalitis. 16 patients with seroconversion by haemagglutination inhibition to St Louis virus were detected. Surveillance of sentinel birds showed that during 1988, 1989, and 1994. St. Louis circulated in the municipalities of Morón, Bolivia and Chambas; whereas in the latter the Eastern equine encephalitis circulated in 1988 and 1989. Antibodies to Western equine encephalitis were detected in sound individuals by haemagglutination inhibition due seemingly to heterologous antibodies, since there were no neutralizing antibodies against this virus.
Subject(s)
Antibodies, Viral/blood , Encephalitis Virus, Eastern Equine/immunology , Encephalitis Virus, Western Equine/immunology , Encephalitis, St. Louis/immunology , Humans , Sentinel SurveillanceABSTRACT
Se analiza el concepto de tecnología de los asentamientos humanos, y se destacan los criterios que avalan la importancia de considerar la participación de la comunidad como un componente de valor de ésta. Se precisan las variantes de esta participación en relación con las diferentes formaciones socioeconómicas. Se señala la necesidad de precisar las características socioeconómicas de cada país, al referirse a la participación popular en determinadas áreas o sectores de la sociedad, por las diferencias que existen en la forma en que esta participa según las distintas estructuras económicas. Se considera que la participación de la comunidad es un proceso en el que pueden identificarse determinadas etapas o fases durante su desarrollo (AU)