Tuning of glyconanomaterial shape and size for selective bacterial cell agglutination.

Multivalent glycosystems are potential candidates for anti-adhesive therapy, a non-lethal approach against the ever increasing antibiotic resistance of pathogenic bacteria. In order to fine-tune the glyconanomaterial size and shape for selective bacterial cell agglutination, herein we report the synthesis of sugar-coated dynamic and polymeric 3D-micelles and 1D-carbon nanotubes. The reported shot-gun like synthetic approach is based on the ability of diacetylenic-based neoglycolipids to self-assemble into micelles in water and hierarchically self-assemble into hemimicelles on a single-walled carbon nanotube surface. The affinity of the nanosystems was preliminarily assessed by enzyme-linked lectin assay (ELLA) using the mannose-specific Concanavalin A lectin as a model receptor. Relative binding potency enhancements, compared to methyl α-d-mannopyranoside used as control, from 10- to 25- to 2340-folds in sugar molar basis were observed when passing from 3D dynamic micelles to static micelles, to 1D-mannose coated carbon nanotubes, respectively, indicative of a significant cluster glycoside effect. Importantly, these results were confirmed in vivo showing that the 1D-glyconanoring-coated carbon nanotubes efficiently and selectively regulate the agglutination and proliferation of the enterobacteria Escherichia coli type 1 fimbriae. These findings highlight the potential of sugar coated nano-materials as novel and effective tools in the control of bacterial pathogenesis.

Synthesis of 1D-glyconanomaterials by a hybrid noncovalent-covalent functionalization of single wall carbon nanotubes: a study of their selective interactions with lectins and with live cells.

To take full advantage of the remarkable applications of carbon nanotubes in different fields, there is a need to develop effective methods to improve their water dispersion and biocompatibility while maintaining their physical properties. In this sense, current approaches suffer from serious drawbacks such as loss of electronic structure together with low surface coverage in the case of covalent functionalizations, or instability of the dynamic hybrids obtained by non-covalent functionalizations. In the present work, we examined the molecular basis of an original strategy that combines the advantages of both functionalizations without their main drawbacks. The hierarchical self-assembly of diacetylenic-based neoglycolipids into highly organized and compacted rings around the nanotubes, followed by photopolymerization leads to the formation of nanotubes covered with glyconanorings with a shish kebab-type topology exposing the carbohydrate ligands to the water phase in a multivalent fashion. The glyconanotubes obtained are fully functional, and able to establish specific interactions with their cognate receptors. In fact, by taking advantage of this selective binding, an easy method to sense lectins as a working model of toxin detection was developed based on a simple analysis of TEM images. Remarkably, different experimental settings to assess cell membrane integrity, cell growth kinetics and cell cycle demonstrated the cellular biocompatibility of the sugar-coated carbon nanotubes compared to pristine single-walled carbon nanotubes.

Bienestar psicológico y prácticas docentes con efectos motivacionales orientadas al aprendizaje / Psychological Well-Being and Learning-oriented Motivational Teaching Practices

Mediante un diseño de investigación descriptivo correlacional se exploran las relaciones entre bienestar psicológico (BP), prácticas docentes con efectos motivacionales orientadas al aprendizaje (PDEM-A) y clima mo-tivacional de clase orientado al aprendizaje (CMC-A), en un grupo de 46 profesores y 1.266 estudiantes. Las medias de las tres variables se ubicaron significativamente por sobre el punto central del rango de respuestas. Se encontró correlación significativa entre BP y PDEM-A r(46) = 0.61, p = 0.01; y no hubo relación entre PDEM-A y CMC-A ni entre BP y CMC-A. Considerar el BP del profesor puede ser relevante para facilitar su disposición hacia las PDEM-A, aunque la relación de estas prácticas con la percepción de los alumnos debe considerarse con mayor detalle.

Relationships between psychological well-being (PWB), learning-oriented motivational teaching practices (LMTP) and learning- oriented motivational classroom climate (LMCC) was explored using co-relational design, in 46 teachers and 1,266 students. The means of the three variables were significantly located above the central point of the response range. Correlation was found between PWB and LMTP r(46) = 0.61, p < 0.01, but there was no significant relationship between LMTP and LMCC, nor LMCC and PWB. To take into account teachers PWB could be relevant to facilitate their disposition toward LMTP, although the relationship of these practices with student's perceptions should be considered in more detail.

Phycobiliproteins or C-phycocyanin of Arthrospira (Spirulina) maxima protect against HgCl(2)-caused oxidative stress and renal damage.

Our objective was to determine if the phycobiliproteins of Arthrospira (Spirulina) maxima protect renal cells against mercury-caused oxidative stress and cellular damage in the kidney. We used 40 male mice that were assigned into eight groups: (1) a control group that received 100mM phosphate buffer (PB) ig and 0.9% saline ip, (2) PB+HgCl(2) (5mg/kg ip), (3) PB plus phycobiliproteins (100mg/kg ig), (4) PB plus C-phycocyanin (100mg/kg ig), and four groups receiving HgCl(2)+phycobiliproteins or C-phycocyanin (50, and 100mg/kg ig). The left kidneys were used to determine lipid peroxidation, quantification of reactive oxygen species, and reduced glutathione and oxidised content. The right kidneys were processed for histology. The HgCl(2) caused oxidative stress and cellular damage. All doses of phycobiliproteins or C-phycocyanin prevented enhancement of oxidative markers and they protected against HgCl(2)-caused cellular damage.

Palmitone prevents pentylenetetrazole-caused neuronal damage in the CA3 hippocampal region of prepubertal rats.

Palmitone is a secondary metabolite of polyketide origin extracted from leaves of Annona diversifolia Saff. (Annonaceae). We found that palmitone possesses anticonvulsant properties against penicillin-, 4-AP-, and pentylenetetrazole (PTZ)-caused seizure in adult animals. Some convulsants as PTZ cause neuronal damage in different brain regions such as the CA3 hippocampal region. Our objective was to evaluate if palmitone protects against PTZ-caused seizures and hippocampal neuronal damage in prepubertal rats. We used 32 prepubertal Wistar rats (30-35 days old) divided into four groups of 8 animals; group I was the control group, group II received a single PTZ dose of 50mg/kg ip, group III received a single palmitone dose of 50mg/kg ip, and group IV received a palmitone dose of 50mg/kg ip plus a PTZ dose of 50mg/kg ip. Ten days after administration, the animals were killed using pentobarbital anesthesia (35 mg/kg). The brains were removed and were embedded in paraffin. Coronal cuts of 7 microm were obtained from -2.8 to -3.3 from Bregma. Each section was stained with cresyl violet-eosin. We evaluated the number of normal and abnormal neurons in the CA3 hippocampal region in a 10,000 microm(2) section. It was observed that palmitone did not prevent the PTZ-caused seizure but palmitone prevents the PTZ-caused neuronal damage in the CA3 hippocampal region.

Linfangioma mesentérico multiquístico como causa de vólvulo intestinal / Mesenteric lymphangioma causing volvulus: report of one case

Lymphangiomas are rare benign lesions, most commonly seen in children and adolescents. Their intra-abdominal presentation is uncommon. We report a 19 years old male, presenting to the emergency room with abdominal pain associated with fever, vomiting and abdominal distension. There was a history of multiple previous consultations for abdominal pain. A plain abdominal X-ray examination suggested a bowel obstruction. At surgery a volvulus and dilation of the small bowel in relation to a vascular malformation was found, excising 40 cm of jejunum with an end-to-end intestinal anastomosis. The pathology report showed a Mesenteric Multicystic Lymphangioma. Presently, the patient is in good conditions.

Los linfangiomas son lesiones benignas, de baja incidencia, más comunes en niños y adolescentes. Con muy baja frecuencia son intraabdominales y poseen presentación clínica variable, yendo desde el hallazgo clínico hasta pacientes con riesgo vital por abdomen agudo. Presentamos el caso de un paciente de 19 años, sin antecedentes mórbidos que acude a urgencias por dolor abdominal asociado a fiebre, vómitos y distensión abdominal; la radiografía simple es sugerente de obstrucción intestinal. En laparotomía exploradora se encuentra un vólvulo y dilatación del intestino delgado en relación a una malformación vascular y lesiones multilobuladas en mesenterio. Se resecan 40 cm de yeyuno y realiza anastomosis término-terminal. La histología reveló un Linfangioma Multiquístico Mesentérico. El paciente evoluciona en buenas condiciones generales y se mantiene control clínico e imagenológico seriado. Aunque infrecuente, es uno de los diagnósticos diferenciales de abdomen agudo. A pesar de su naturaleza benigna puede llegar a comprometer el pronóstico vital del paciente.

Anticuerpos anti-tiroglobulina en el seguimiento de pacientes con cáncer diferenciado de tiroides: ¿marcadores de enfermedad residual o recidivante? / Anti thyroglobulin antibodies in the follow up of patients with differentiated thyroid cancer

Background: Anti thyroglobulin antibodies are present in 25 percent of patients treated for a differentiated thyroid cancer, invalidating thyroglobulin determination. Those patients subjected to total thyroidectomy and free of disease, should reduce the production of these antibodies, due to the lack of antigenic stimulus. Therefore, anti thyroglobulin antibodies could be useful to detect early relapses. Aim: To assess the relationship between anti thyroglobulin antibodies and the evolution of the disease in patients treated for thyroid cancer. Material and methods: Retrospective analysis of 26 patients treated for thyroid cancer with positive anti thyroglobulin antibodies, followed for three years. These were divided in those with or without lymphocytic thyroiditis (19 and 7 respectively). Results: At the first year of follow up, anti thyroglobulin antibody concentration was 401ñ94.9 UI/ml (xñsem) in patients with thyroiditis and 38.9ñ8.9 UI/ml in those without thyroiditis (p < 0.005). During the three years of follow up, no differences in anti thyroglobulin antibodies were observed between patients with or without tumor relapse. Conclusions: Concentration of anti thyroglobulin antibodies was higher in patients with thyroiditis and did not differentiate patients with tumor relapse

Medición de 17-OH progesterona sanguínea en recién nacidos chilenos: antecedentes para implementar un programa de detección neonatal de hiperplasia suprarrenal congénita / 17 OH progesterone measurement in blood of chilean newborns: as a background to start a congenital adrenal hyperplasia screening program

Background: The early diagnosis and therapy of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency can prevent adrenal crises and erroneous gender assignment in affected newborns. To achieve this goal neonatal mass-screening programs have been developed, measuring blood 17 alpha-hydroxyprogesterone (17OHP). In Chile there is no experience with this type of screening. Aim: To develop a method for measuring 17OHP in filter paper blood specimens. To obtain reference ranges and determine neonatal 17OHP threshold levels according to gestational age and birth weight. To analyze factors affecting the cost-efficiency ratio and suggest recommendations for the organization of a neonatal screening program for CAH in Chile. Material and methods: Nine hundred twenty two newborns were studied. 17OHP was measured using double antibody radioimmunoassay in filter paper blood samples obtained 48 h after birth. Reference ranges were determined according to gestational age and birth weight and a cutoff point of 25 ng/ml was established. Results: Seventeen newborns had 17OHP over the cutoff value. They were assessed by a pediatric endocrinologist and in none of them, CAH was confirmed. Therefore the false positive rate of the determination was 1.8 percent. Among these newborns with elevated 17OHP, 66 percent had a birth weight below 1.5 kg and 5.8 percent, a birth weight between 1.5 and 2.5 kg. The cost per reported result was US $ l. Timing of the recall was between the 3 and 10 days of life. No newborn missed the follow-up. Discussion: To increase the cost-efficiency ratio of an eventual neonatal screening program, newborns with birth weights below 1.5 kg should be excluded and cutoff points should be defined according to birth weight

Autoanticuerpos anti-tiroglobulina: detección y posible interferencia en la medición de tiroglobulina en suero / Thyroglobulin autoantibodies: detection and possible interference in serum thyroglobulin measurement

Background: Thyroglobulin measurement is useful for the follow up of patients subjected to total thyroidectomy for differentiated thyroid carcinoma. Thyroglobulin autoantibodies may interfere with its determination. Aim: To measure thyroglobulin autoantibodies and their interference with thyroglobulin determination. Material and methods: The presence of thyroglobulin autoantibodies was investigated in 801 serum samples sent to the laboratory for measurement of thyroglobulin levels. A serum was considered positive for these autoantibodies when radioactivity corresponding to 125I-thyroglobulin bound to thyroglobulin autoantibodies, precipitated with human gamma globulin, exceeded in 1.4 times that of a negative sera pool. In positive sera, thyroglobulin autoantibody concentration was measured and its interference with thyroglobulin radioimmunoassay was assessed through a recuperation test using exogenous thyroglobulin. Results: Thyroglobulin autoantibodies were detected in 149 sera (18.6 percent). Of these, 65 had a recuperation that fluctuated between 1 and 80 percent. Thyroglobulin autoantibody concentration was negatively correlated with recuperation percentages (r= -0.64; p <0.001) but not with thyroglobulin concentrations (r= 0.08). Thyroglobulin was higher in positive sera with a recuperation over 80 percent than in sera with a recuperation of less than 80 percent (12.7 ñ 1.7 and 5.9 ñ 0.6 ng/ml, respectively; p <0.001). Conclusions: Thyroglobulin autoantibodies interfere with thyroglobulin measurement by radioimmunoassay, sequestering variable amounts of thyroglobulin. The presence of these autoantibodies must be investigated prior to thyroglobulin determination

Copépodos dulceacuícolas de vida libre en el Perú familia Cyclopidae, Orden Cyclopoida / Copépodos dulceacuícolas of free life in the Peru family Cyclopidae, Order Cyclopoida

Copepods (Class: crustacea; subclase: cepepods) are small arthropods (microcrustaceans) whose life forms constitute an important part o zooplankton. The authors presents a brief history of the different studies carried out on these extant species found in fresh water in Peru. They include a list of the 49 species known in Peru to date. In particular, they refer to the 21 species in the Cyclopidae family, order Cyclopoida, pointing out their principal characteristic, providing detailed drawing in order to identify them.

Los copépodos (clase Crustácea, subclase Copepoda) son artrópodos pequeños o microcrustáceos, cuyas formas de vida libre constituyen parte muy importante del zooplancton. Los autores hacen una breve historia de los diferentes estudios que se han efectuado sobre estas especies existentes en los cuerpos de agua dulce del Perú. Incluyen una lista de los 49 especies que hasta la fecha se conocen en el Perú. Particularmente se refieren a las 21 especies de la familia Cyclopidae, del orden Cyclopoida, destacando sus características principales, con ilustraciones precisas para su reconocimiento.

Vía transdiafragmática de abordaje de la glándula suprarrenal / Transdiaphagmatic approach way to the adrenal gland

Se mencionan las distintas técnicas para el abordaje quirúrgico a las glándulas suprarrenales, describiendo detalladamente la vía transdiafragmática. Se reportan tres casos operados con esta técnica. Se recomienda esta vía en pacientes obesos, y en todos los casos con tumoraciones unilaterales grandes, especialmente en la teocromocitoma, por el amplio campo operatorio y adecuada exposición de la glándula (AU)

Patología no tumoral del esfínter de Oddi; conceptos sobre esta entidad y conducta a seguir sobre la misma

Se exponen los aspectos de clasificación, sintomatología, diagnóstico y tratamiento que se siguen en nuestro servicio arribándose a las siguientes conclusiones: La sintomatología puede orientar en el diagnóstico lográndose definitivamente éste en el preoperatorio por medio de la colangiografía endovenosa, sin el uso de morfina, destacando el valor del tiempo de densidad del colédoco, en los casos que no tiene una vesícula funcional o en los previamente colecistectomizados. Durante el acto quirúrgico se llega al diagnóstico principalmente por medio de la radiomanometría, destacándose el valor del hallazgo de presiones altas e imágenes en forma de copa del extremo distal del colédoco. La técnica quirúrgica a emplear como tratamiento está en función de la clasificación etiológica no siendo, por lo tanto, dogmática y será de elección de acuerdo con el caso (AU)