Additive manufactured gyroid-based cell structures under compression: design, testing and simulation for biomedical applications.

The mechanical behaviour of a DMLS Ti-6Al-4V gyroid-based cellular structure (CS), with potential application in the fabrication of implants, was studied under compressive conditions. The influence of the CS volumetric fraction on the elastic modulus was experimentally evaluated in cubic and cylindrical samples. The experimental results showed that the selected parameters allowed approximating the mechanical behaviour of the CS to that of trabecular bone. Finite element analysis was employed to study the mechanical behaviour of the CS. The model presented a good approximation of the experimental results, being useful to predict the mechanical behaviour of the CS.

Long-term effects of hypercalcemia in kidney transplant recipients with persistent hyperparathyroidism.

BACKGROUND: Hypercalcemia is highly prevalent in kidney transplant recipients with hyperparathyroidism. However, its long-term impact on graft function is uncertain. METHODS: We conducted a prospective cohort study investigating adverse graft outcomes associated with persistent hypercalcemia (free calcium > 5.2 mg/dL in ≥ 80% of measures) and inappropriately elevated intact parathyroid hormone (> 30 pg/mL) in kidney transplant recipients. Asymptomatic mild hypercalcemia was monitored unless complications developed. RESULTS: We included 385 kidney transplant recipients. During a 4-year (range 1-9) median follow-up time, 62% of kidney transplant recipients presented persistent hypercalcemia. Compared to kidney transplant recipients without hypercalcemia, there were no significant differences in graft dysfunction (10% vs. 12%, p = 0.61), symptomatic urolithiasis (5% vs. 3%, p = 0.43), biopsy-proven calcium deposits (6% vs. 5%, p = 1.0), fractures (6% vs. 4%, p = 0.64), and a composite outcome of urolithiasis, calcium deposits, fractures, and parathyroidectomy indication (16% vs. 13%, p = 0.55). In a subset of 76 kidney transplant recipients, subjects with persistent hypercalcemia had higher urinary calcium (median 84 [43-170] vs. 38 [24-64] mg/day, p = 0.03) and intact fibroblast growth factor 23 (median 36 [24-54] vs. 27 [19-40] pg/mL, p = 0.04), and lower 25-hydroxyvitamin D levels (11.3 ± 1.2 vs. 16.3 ± 1.4 ng/mL, p < 0.001). In multivariate analysis, pretransplant intact parathyroid hormone < 300 pg/mL was associated with a reduced risk of post-transplant hypercalcemia (OR 0.51, 95% CI 0.32-0.80). CONCLUSIONS: Long-term persistent mild hypercalcemia (tertiary hyperparathyroidism) was frequent in kidney transplant recipients in our series. This condition presented with lower phosphate and 25-hydroxyvitamin D, and higher urinary calcium and intact fibroblast growth factor 23 levels compared to kidney transplant recipients without hypercalcemia, resembling a mild form of primary hyperparathyroidism. Despite these metabolic derangements, the risk of adverse graft outcomes was low.

Cistoadenoma mucinoso biliar: Un reto diagnóstico / Mucinous biliary cystadenoma: A diagnostic challenge

Introducción. El cistoadenoma mucinoso biliar es una neoplasia rara con alta probabilidad de malignidad. Su diagnóstico es un reto ya que se asemeja a otras masas benignas que pueden encontrarse en el hígado. Caso clínico. Mujer de 21 años con sensación de masa en hipocondrio derecho, a quien se le realizan marcadores tumorales y estudios de imágenes concluyendo que se trataba de un cistadenoma mucinoso biliar. Resultado. Se presenta el caso de una paciente con cistoadenoma mucinoso biliar, diagnosticada y tratada exitosamente con cirugía. Conclusión. El diagnóstico de cistoadenoma mucinoso biliar se confirma mediante marcadores tumorales y estudios radiológicos, y su tratamiento es quirúrgico debido al riesgo de malignidad

Introduction. Biliary mucinous cystadenoma is a rare neoplasm with a high probability of malignancy. Its diagnosis is a challenge since it resembles other benign masses that can be found in the liver. Clinical case. A 21-year-old woman with a sensation of a mass in the right hypochondrium, who underwent tumor markers and imaging studies, concluding with a diagnosis of biliary mucinous cystadenoma. Result. A case of a patient with biliary mucinous cystadenoma diagnosed and successfully treated by surgery is presented. Conclusion. The diagnosis of biliary mucinous cystadenoma is confirmed by tumor markers and radiological studies, and its treatment is surgical due to the risk of malignancy

Submucosal resection via a transanal approach for treatment of epithelial rectal tumors - a multicenter study.

OBJECTIVE: To report complications and long-term outcomes after submucosal resections of benign and malignant epithelial rectal masses. STUDY DESIGN: Retrospective multicentric study. SAMPLE POPULATION: Medical records of 93 dogs at 7 referral hospitals. METHODS: Records were reviewed for surgical time, diagnosis, margins, complications, and recurrences. Survival of dogs was evaluated based on tumor types, categorized as benign, carcinoma in situ, and carcinoma. The Kaplan-Meier survival curve and Cox proportional hazards analysis were used to determine the association of a range of variables with recurrence and survival time. RESULTS: Duration of follow up was 708 days (range, 25-4383). Twenty-seven dogs (29%) developed complications. Recurrence was identified in 20/93 (21%), with 12/20 recurrent masses treated with repeat submucosal resection. Median survival was not reached in any group. The 1-,2-, 5-year survival rates for carcinomas were 95%, 89%, and 73% respectively. However, overall survival was longer for benign tumors than carcinomas (P = .001). Recurrence was more likely when complications (P = .032) or incomplete margins (P = .023) were present. Recurrence was associated with an increased risk of death (P = .046). CONCLUSION: Submucosal resection of both benign and malignant rectal masses was associated with a low rate of severe complications and prolonged survival in the 93 dogs described here. CLINICAL SIGNIFICANCE: Submucosal resection is a suitable technique for resection of selected rectal masses.

Design and Fabrication of a Customized Partial Hip Prosthesis Employing CT-Scan Data and Lattice Porous Structures.

As a larger elderly human population is expected worldwide in the next 30 years, the occurrence of aging-associated illnesses will also be increased. The use of prosthetic devices by this population is currently important and will be even more dramatic in the near future. Hence, the design of prosthetic devices able to reduce some of the problems associated with the use of current components, such as stress shielding, reduced mobility, infection, discomfort, etc., becomes relevant. The use of additive manufacturing (AM) and the design fabrication of self-supported cellular structures in the biomedical area have opened up important opportunities for controlling the physical and mechanical properties of hip implants, resulting in specific benefits for the patients. Different studies have reported the development of hip prosthetic designs employing AM, although there are still opportunities for improvement when it comes to customized design and tuning of the physical and mechanical properties of such implants. This work shows the design and manufacture by AM of a personalized stainless-steel partial hip implant using tomography data and self-supported triply periodic minimal surface (TPMS) cell structures; the design considers dimensional criteria established by international standards. By employing tomography data, the external dimensions of the implant were established and the bone density of a specific patient was calculated; the density and mechanical properties in compression of the implant were modulated by employing an internal gyroid-type cell structure. Using such a cell structure, the patient's bone density was emulated; also, the mechanical properties of the implant were fine-tuned in order to make them comparable to those reported for the bone tissue replaced by the prosthesis. The implant design and manufacturing methodology developed in this work considered the clinical condition of a specific patient and can be reproduced and adjusted for different types of bone tissue qualities for specific clinical requirements.

Early outcomes in kidney transplant recipients with systemic lupus erythematosus.

Kidney transplant (KT) is the best treatment for patients who progress to end-stage renal disease. Short-term outcomes in patients with systemic lupus erythematosus (SLE) following KT are not well known. To describe the postoperative outcomes and complications in SLE patients undergoing KT, we conducted a case-control study from 2010 to 2015 including SLE recipients compared to non-SLE controls matched by age and sex. Demographics, comorbidities, donor characteristics, and preoperative tests were retrieved. Main outcomes were 30-day postoperative allograft function, development of infectious or non-infectious complications, and mortality. 68 patients (34 SLE, 34 non-SLE) were included. SLE recipients had median disease duration of 9 years; SLEDAI-2K of 2, and SLICC/ACR damage index of 3; 16 (47%) were taking prednisone (median dose 5 mg daily) before KT. SLE recipients had a lower frequency of diabetes (0 vs. 27%, p = 0.002). No differences were found in the development of any complication (50% SLE vs. 47% non-SLE, p = 1.00); infectious (44% vs. 41%, p = 1.00), or non-infectious (15% vs. 21%, p = 1.00). There were no deaths in either group, and none of the SLE recipients presented lupus disease activity 30 days after the KT. Allograft function determined by serum creatinine, estimated glomerular filtration rate, delayed graft function, and allograft loss was similar in both groups (p > 0.05). There were no differences between SLE recipients with and without complications. Early postoperative outcomes in SLE patients who undergo KT, including allograft function, development of infectious, non-infectious complications, and mortality, are similar to patients without SLE.

Screeninig en cáncer de próstata, ¿En qué estamos ahora? Revisión de la literatura / Proatate cancert screeninig, where are we now ? a review of the literature

El cáncer de próstata es el segundo cáncer más prevalente en hombres en el mundo. Corresponde a la segunda causa de muerte por cáncer en hombres en Chile y EE.UU. convirtiéndose de esta manera en un problema de salud pública relevante. Hemos visto una serie de modificaciones a las recomendaciones de tamizaje del cáncer de próstata. Esta revisión tiene por objetivo resumir los principales acontecimientos en cuanto a recomendaciones sobre screening. La USPSTF ha realizado recomendaciones y variaciones a estas, siendo la última publicada en abril 2017. En Chile el screening no está incluido dentro de un programa ministerial y las últimas recomendaciones son del 2010. El uso y abuso del APE conlleva un stress emocional y eventuales complicaciones al paciente. Parece razonable, entonces, plantear un algoritmo basado no sólo en un parámetro predeterminado para definir si un paciente debe realizarse una biopsia o no, sino que incorporar al paciente en una toma de decisión informada.(AU)

Prostate cancer is the second cancer diagnosed in men in the world. It corresponds to the second cause of cancer death in men in Chile and the United States, thus becoming a relevant public health problem. We've seen a number of changes in prostate cancer screening recommendations. This review aims to summarize the main events regarding recommendations on screening. The USPSTF has made recommendations and variations to these subject, the last one being published in April 2017. In Chile, screening is not included in a ministerial program and the latest recommendations date from 2010. The use and abuse of the PSA brings emotional stress, as well as risks to the patient. It seems reasonable to propose an algorithm based not only on a parameter to define whether a patient requires a biopsy or not, but to incorporate the patient into an informed decision-making.(AU)

Descripción de una técnica mínimamente invasiva, sencilla y de bajo costo para la resolución de estenosis de la vía urinaria superior: experiencia inicial / Minimally invasive and low cost approach for the treatment of upper urinary tract stenosis: surgical techniques and initial experience

El avance de las técnicas mínimamente invasivas y la aparición de nuevos dispositivos han llegado a resolver muchas de las patologías urológicas actuales, sin embargo, estas técnicas no siempre son simples de realizar y suelen asociarse a un aumento en los costos de insumos y equipos, limitando su uso. En el presente trabajo describimos nuestra experiencia inicial en el manejo de estenosis de la vía urinaria superior utilizando una técnica endoscópica con papilótomo y precut (instrumental gastroenterológico para ERCP) bajo visión fluoroscópica. Se presentan tres casos clínicos, dos de ellos con estenosis del cuello del cáliz superior (CCS) izquierdo y uno con una estenosis pieloureteral derecha recidivada luego de una pieloplastía laparoscópica. En los tres pacientes se logró abrir las zonas estenóticas obteniendoimágenes fluoroscópicas satisfactorias. No hubo complicaciones durante la cirugía ni en el postoperatorio.El alta se dio entre las 24 y 72 hrs posprocedimiento. La técnica empleada permite corregir estenosis de la vía urinaria superior, con equipos e insumos que se encuentran disponibles en la mayoría de los centros públicos y privados del país, de manera sencilla, económica, segura y mínimamente invasiva. Si bien los resultados iniciales obtenidos son muy alentadores, se debe tener presente que las estenosis de la vía urinaria tienden a recidivar, por lo que el éxito a largo plazo y el porcentaje de reestenosis es aún desconocido.

Minimally invasive techniques (MIT) are both difficult to perform and costly in terms of equipment and supplies. The latter has limited the expansion of MIT. Herein, we describe a technique for management of upper tract urinary estenosis with the deploy of endoscopic retrograde colangiopancreatoscopy equipment (ERCP) and radiologic assistance. Three cases were treated with the technique. Two cases with superior calyx estenosis and 1 case with recidivated ureteropelvic stenosis. All three patients were solved with the proposed technique with adequate radiographic results verified at the end of the procedure. There were no perioperative complications and patients were discharged between 24 and 72 hours after the procedure. The technique offers a safe, reliable and low cost approach for the urinary tract stenosis. Follow-up is mandatory.

Anestesia local en la herniorrafia inguinal: bloqueo en cinco puntos anatómicos / Local anesthesia in the inguinal hernia repair: locking in five anatomical points

Evaluar los beneficios y la tolerancia del acto quirúgico con anestesia local en cinco puntos anatómicos en el tratamiento de la herniorrafia inguinal. Departamento de Cirugía General, Hospital General del Oeste "Dr. José Gregorio Hernández, Los Magallanes, Catía, Caracas-Venezuela. Estudio prospectivo en pacientes con diagnóstico de hernia inguinal que acudieron a la consulta externa de cirugía durante el lapso de un año, quienes fueron intervenidos utilizando anestesia local mediante la técnica de bloqueo en cinco puntos anatómicos más sedación. La técnica quirúrgica para reforzar la pared posterior se dejó a criterio del cirujano. La tolerancia al procedimiento se basó en la necesidad de emplear más unidad anestésicas. Cincuenta y nueve pacientes integraron el grupo, 21 tenían patología bilateral, para un total de 80 hernias. Todos soportaron el procedimiento, 95 por ciento tuvieron buena tolerancia, y 5 por ciento baja tolerancia. Hubo 3 complicaciones posoperatorias (3,75 por ciento) y una intra-operatoria (1,25 por ciento). La observación posoperatoria intra-hospitalasria fue en promedio de 2 horas 40 min y el 97,5 por ciento de los pacientes regresaron al grupo familiar inmediatamente. El reintegro al trabajo promedio 9,5 días. Los costos hospitalarios se redujeron considerablemente. El bloqueo local la cura quirúrgica de hernia inguinal se fundamenta en la neuroanatomía de la región inguinal, es altamente eficaz, bien tolerado y proporciona una disminución de costo muy significativa.

Determinar los constituyentes químicos en la hoja de la Cissus verticillata L. por medio de un screenig fitoquímico / Determine the chemical constituents in the leaf of Cissus verticillata L. by means of a phytochemical screenig

La Cissus verticillata L. es una especie vegetal muy usada por parte de la población en el tratamiento de un sinnúmero de patologías; a pesar de su alto uso, el investigador no se ha visto motivado en realizar un estudio en la especie. Debido a la carencia de estudios de investigación sobre la Cissus verticillata L., la pobreza por parte de la población y los usos etnomédicos de la especie; consideramos emprender un Screening fitoquímico en la hoja de la Cissus verticillata L. El presente estudio de tipo experimental fue realizado en al laboratorio de Farmacognosia del Departamento de Análisis de Medicamentos y Drogas de la Facultad de Ciencias Químicas. La muestra en estudio forma parte de la familia Vitaceae, tomando como unidad de análisis la hoja de la especie, por estar presente la mayoría de los constituyentes de la especie. Una vez seleccionada la unidad de análisis se procedió a la recolección e identificación de la especie, secado, trituración y por último la realización del Screening fitoquímico. Los constituyentes químicos identificados en la hoja de la Cissus verticillata L., fueron: Triterpenos/Esteroles, Ácidos grasos, Alcaloides, Carotenoides, Cumarinas, Taninos catéquicos, Compuestos reductores, Antracenósidos, Antocianinas y Polisacáridos; agrupados todos ellos en los extractos etéreo, alcohólico y acuoso. Los constituyentes químicos identificados, fueron todos aquellos que se encuentran en la familia Vitaceae, comprobando que la composición química de las especies de la familia Vitaceae; no varían cualitativamente. Así mismo, los ácidos grasos y flavonoides son constituyentes químicos que se informan por primera vez en la hoja de las especies de la familia Vitaceae. Para la realización del Screening se usaron solventes de diferentes polaridades para obtener extractos con la mayor cantidad de constituyentes químicos.