Bioelectronics-on-a-chip for cardio myoblast proliferation enhancement using electric field stimulation

Ángel Aragón,María Cebro-Márquez,Eliseo Perez,Antonio Pazos,Ricardo Lage,José Ramón González-Juanatey,Isabel Moscoso,Carmen Bao-Varela,Daniel Nieto 한국생체재료학회 2020 생체재료학회지 Vol.24 No.3

Background: Cardio myoblast generation from conventional approaches is laborious and time-consuming. We present a bioelectronics on-a-chip for stimulating cells cardio myoblast proliferation during culture. Method: The bioelectronics chip fabrication methodology involves two different process. In the first step, an aluminum layer of 200 nm is deposited over a soda-lime glass substrate using physical vapor deposition and selectively removed using a Q-switched Nd:YVO4 laser to create the electric tracks. To perform the experiments, we developed a biochip composed of a cell culture chamber fabricated with polydimethylsiloxane (PDMS) with a glass coverslip or a cell culture dish placed over the electric circuit tracks. By using such a glass cover slip or cell culture dish we avoid any toxic reactions caused by electrodes in the culture or may be degraded by electrochemical reactions with the cell medium, which is crucial to determine the effective cell-device coupling. Results: The chip was used to study the effect of electric field stimulation of Rat ventricular cardiomyoblasts cells (H9c2). Results shows a remarkable increase in the number of H9c2 cells for the stimulated samples, where after 72 h the cell density double the cell density of control samples. Conclusions: Cell proliferation of Rat ventricular cardiomyoblasts cells (H9c2) using the bioelectronics-on-a-chip was enhanced upon the electrical stimulation. The dependence on the geometrical characteristics of the electric circuit on the peak value and homogeneity of the electric field generated are analyzed and proper parameters to ensure a homogeneous electric field at the cell culture chamber are obtained. It can also be observed a high dependence of the electric field on the geometry of the electrostimulator circuit tracks and envisage the potential applications on electrophysiology studies, monitoring and modulate cellular behavior through the application of electric fields.

Intron 4 VNTR (4a/b) Polymorphism of the Endothelial Nitric Oxide Synthase Gene Is Associated with Breast Cancer in Mexican Women

Ramírez-Patiño Ramiro,Figuera Luis Eduardo,Puebla-Pérez Ana María,Delgado-Saucedo Jorge Ivan,Legazpi-Macias María Magdalena,Mariaud-Schmidt Rocio Patricia,Ramos-Silva Adriana,Gutiérrez-Hurtado Itzae A 대한의학회 2013 Journal of Korean medical science Vol.28 No.11

The endothelial nitric oxide synthase (eNOS) gene plays an important role in several biological functions. Polymorphisms of the eNOS gene have been associated with cancer. It has been suggested that the VNTR 4 a/b polymorphism may affect the expression of eNOS and contributes to tumor promotion in the mammary gland. We examined the role of the eNOS4 a/b polymorphism by comparing the genotypes of 281 healthy Mexican women with the genotypes of 429 Mexican women with breast cancer (BC). The observed genotype frequencies for control and BC patients were 0.6% and 0.7% for a/a (polymorphic); 87% and 77% for a/a (wild type); and 12% and 22% for a/b respectively. We found that the odds ratio (OR) was 1.9, with a 95% confidence interval (95%CI) of 1.29-2.95, P=0.001 for genotypes a/a-a/b, b/c. The association was also evident when comparing the distribution of the a/a-a/b genotypes in patients with high levels of glutamate-oxaloacetate transaminase (SGOT) (OR, 1.93; 95% CI, 1.14-3.28; P=0.015); undergoing menopause with high levels of SGOT (OR, 2.0; 95% CI, 1.1-3.84); and with high levels of glutamic-pyruvic transaminase (SGPT) (OR, 3.5; 95% CI, 1.56-8.22). The genotypes a/a-a/b are associated with BC susceptibility in the analyzed samples from the Mexican population.

Synthesis of Bi₂W₂O9 from an amorphous complex precursor: characterization and evaluation of its photocatalytical properties

A. Martínez-de la Cruz,S. Obregón Alfaro,Leticia M. Torres-Martínez,I. Juárez Ramírez 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.5

Bismuth tungstate Bi2W2O9 has been synthesized using diethylenetriaminepentaacetic acid (H5DTPA), an organic chelating agent of metals in an aqueous solution. The formation of the oxide was followed through characterization techniques such as XRD, TGA/DTA, and SEM. The optimum temperature to decompose the organic matrix and to form Bi2W2O9 was determined to be around 720 oC. Below this temperature, Bi2W2O9 was formed with a high content of Bi2WO6. At 720 oC particles of the Bi2W2O9 with a surface area four times higher than that obtained by a solid-state reaction were obtained. The oxide was tested as a photocatalyst on the degradation of aqueous solutions of rhodamine B under VIS radiation. The photodegradation of the dye followed a kinetic first order with an apparent constant, k = 2.8 × 10−3 minute−1and t1/2= 247 minutes for an aqueous solution of 5 mg l−1 of rhodamine B. Bismuth tungstate Bi2W2O9 has been synthesized using diethylenetriaminepentaacetic acid (H5DTPA), an organic chelating agent of metals in an aqueous solution. The formation of the oxide was followed through characterization techniques such as XRD, TGA/DTA, and SEM. The optimum temperature to decompose the organic matrix and to form Bi2W2O9 was determined to be around 720 oC. Below this temperature, Bi2W2O9 was formed with a high content of Bi2WO6. At 720 oC particles of the Bi2W2O9 with a surface area four times higher than that obtained by a solid-state reaction were obtained. The oxide was tested as a photocatalyst on the degradation of aqueous solutions of rhodamine B under VIS radiation. The photodegradation of the dye followed a kinetic first order with an apparent constant, k = 2.8 × 10−3 minute−1and t1/2= 247 minutes for an aqueous solution of 5 mg l−1 of rhodamine B.

Chimeric Myostatin - Tetanic Toxin Epitopes and Heterologous Prime-boost Immunization Improve Immune Response Stimulating Muscle Growth in Mice

Vianey Ramírez Andoney,Amanda Gayosso Vázquez,Juan Pablo Pintor Ríos,Jorge Enrique Vázquez Buchelli,Rogelio A. Alonso Morales 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.5

Myostatin is a transforming growth factor-β family member who acts as a negative regulator of skeletal muscle growth. The interference of its biological activity could increase skeletal muscle growth with clinical and animal production applications. A strategy to block the myostatin action is by the induction of an immune response against it. In this work, we evaluated as an immunogen a recombinant myostatin fused to the tetanic toxin T- helper epitopes P2 and P30. Genetic constructs of the chimeric myostatin were cloned in an expression vector and used as a DNA vaccine. Besides, a chimeric genetic construct, P2-miostatin–P30 was expressed in Escherichia coli, obtaining a recombinant chimeric antigen. To find out the functionality of these genetic constructs as a vaccine in inducing muscle growth responses, experimental groups of BALB/c mice were DNA immunized with the myostatin fused to P2, P30 or both. Furthermore, to improve the immune response, a heterologous prime–boost immunization scheme was evaluated where the DNA inoculation was followed by immunization with the recombinant antigen P2-myostatin-P30. The different body segments weight was recorded in control and vaccinated mice groups, finding increased muscle masses in the vaccinated groups. These experiments showed the effectiveness of the P2 and P30 Thelper epitopes in inducing an immune response to the fused myostatin, leading to muscle growth. The heterologous prime-boost immunization protocol is a promising vaccination strategy reducing the time and amount of antigen used to induce a immune response to myostatin.

Dye-Perfused Human Placenta for Simulation in a Microsurgery Laboratory for Plastic Surgeons

Zambrano-Jerez Laura C.,Díaz-Santamaría Karen D.,Rodríguez-Santos María A.,Alarcón-Ariza Diego F.,Meléndez-Flórez Genny L.,Ramírez-Blanco Mónica A. 대한성형외과학회 2023 Archives of Plastic Surgery Vol.50 No.6

In recent decades, a number of simulation models for microsurgical training have been published. The human placenta has received extensive validation in microneurosurgery and is a useful instrument to facilitate learning in microvascular repair techniques as an alternative to using live animals. This study uses a straightforward, step-by-step procedure for instructing the creation of simulators with dynamic flow to characterize the placental vascular tree and assess its relevance for plastic surgery departments. Measurements of the placental vasculature and morphological characterization of 18 placentas were made. After the model was used in a basic microsurgery training laboratory session, a survey was given to nine plastic surgery residents, two microsurgeons, and one hand surgeon. In all divisions, venous diameters were larger than arterial diameters, with minimum diameters of 0.8 and 0.6 mm, respectively. The majority of the participants considered that the model faithfully reproduces a real microsurgical scenario; the consistency of the vessels and their dissection are similar in in vivo tissue. Furthermore, all the participants considered that this model could improve their surgical technique and would propose it for microsurgical training. As some of the model's disadvantages, an abundantly thick adventitia, a thin tunica media, and higher adherence to the underlying tissue were identified. The color-perfused placenta is an excellent tool for microsurgical training in plastic surgery. It can faithfully reproduce a microsurgical scenario, offering an abundance of vasculature with varying sizes similar to tissue in vivo, enhancing technical proficiency, and lowering patient error.

Silver nanoparticles incorporated into Na₂Ti6O13 microfibers

V. Rodríguez-González,I. Juárez-Ramírez,R. Zanella,M.E. Zarazúa,L.M. Torres-Martínez 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.6

This research is concerned with novel semiconductor composites of sodium hexatitanate oxide (Na2Ti6O13), and silver metallic nanoparticles. The Na2Ti6O13 was prepared by two methods, a sol-gel process and a solid state reaction. The silver nanoparticles were incorporated into the titanate by a deposition-precipitation technique, using NaOH as precipitation agent in the dark. Ag/Na2Ti6O13 microfibers were obtained by the sol-gel method, meanwhile octagonal microbar agglomerates were the product of the solid state reaction. The SEM-TEM observations showed silver particles with a nanometric size (5-7 nm); and fibrillar structures in the sol-gel sodium titanates. The UV-Vis-RD spectroscopy showed a blue shift Eg from 3.3 to 3.4 nm; and a plasmon surface resonance in the visible region. These materials are proposed as potential photocatalysts for contaminated water purification. This research is concerned with novel semiconductor composites of sodium hexatitanate oxide (Na2Ti6O13), and silver metallic nanoparticles. The Na2Ti6O13 was prepared by two methods, a sol-gel process and a solid state reaction. The silver nanoparticles were incorporated into the titanate by a deposition-precipitation technique, using NaOH as precipitation agent in the dark. Ag/Na2Ti6O13 microfibers were obtained by the sol-gel method, meanwhile octagonal microbar agglomerates were the product of the solid state reaction. The SEM-TEM observations showed silver particles with a nanometric size (5-7 nm); and fibrillar structures in the sol-gel sodium titanates. The UV-Vis-RD spectroscopy showed a blue shift Eg from 3.3 to 3.4 nm; and a plasmon surface resonance in the visible region. These materials are proposed as potential photocatalysts for contaminated water purification.

동해 남부 연안 해역에서 냉수대 발생이 식물플랑크톤 군집에 미치는 영향

김아람,윤석현,정미희,윤상철,문창호,Kim, A-Ram,Youn, Seok-Hyun,Chung, Mi-Hee,Yoon, Sang-Chol,Moon, Chang-Ho 한국해양학회 2014 바다 Vol.19 No.4

냉수대 발생 전 후의 해양 환경과 식물플랑크톤 군집 구조 및 크기를 파악을 위해 여름철 빈번하게 냉수대가 발생되는 동해 남부 해역(울산 정자~부산 일광) 18개 정점에서 2013년 5월부터 8월까지 냉수대 발생 환경 및 식물플랑크톤 군집 구조를 조사하였다. 냉수대는 7월과 8월에 연안 정점(A1, B1, C1)에서 발생하였고, 표층에서 저온 고염의 특성을 보였다. 이 시기에 영양염은 수온과 유의한 음의 상관관계(DIP, r=-0.218, p<0.01; DIN, r=-0.306, p<0.01; silicate, r=-0.274, p<0.01)를 보여, 찬 해수가 분포하는 표층에 영양염이 풍부함을 알 수 있었다. 출현한 식물플랑크톤은 총 186종이었고, 현존량은 5월(C1, $726{\times}10^3cells\;L^{-1}$)과 7월(A1, $539{\times}10^3cells\;L^{-1}$)에 높았다. 또한, 연안 정점에서 총 chl. a 와 소형플랑크톤 chl. a ($>20{\mu}m$)의 농도가 냉수대 발생 시기인 7, 8월에 뚜렷하게 증가한 반면, 수온약층이 형성된 6월에는 현저하게 낮았다. 6월의 우점종은 Pseudo-nitzschia spp.이었고, 그 세포 크기는 $309{\mu}m^3$로 다른 시기의 식물플랑크톤의 1/10 수준에 머무는 작은 크기였다. 이러한 결과는 7월과 8월에 총 chl. a의 증가와 식물플랑크톤의 크기 증가가 냉수대 발생 시에 표층으로 공급된 영양염의 영향임을 시사한다. 이러한 해양 환경 특성과 식물플랑크톤 출현양상은 연안 정점에서 뚜렷하게 보였고, 외측 정점에서는 관찰되지 않았다. 이 연구에서는 동해 남부 해역에서 냉수대가 발생하면 식물플랑크톤의 현존량 증가와 더불어 비교적 크기가 큰 식물플랑크톤의 출현 빈도가 증가하는 현상을 확인하였다. 결과적으로 하계에도 불구하고 동해 남부 연안 해역에서 냉수대 발생에 따른 영양염 공급은 식물플랑크톤 군집조성과 현존량에 상당한 영향을 미치는 것으로 판단된다. In order to understand environment condition and phytoplankton community before and after coastal upwelling, the influences of upwelling events on phytoplankton community were studied at 18 stations located the Southern part of East Sea, Korea from May to August 2013. The surface water masses showed low temperature and high salinity due to upwelling events at coastal stations (A1, B1, C1). Correlation between temperature and nutrients (DIP, r=-0.218, p<0.01; DIN, r=-0.306, p<0.01; silicate, r=-0.274, p<0.01) was significantly negative. This result could be explained that nutrients were supplied to surface water by the upwelling of bottom water. Phytoplankton communities were composed of 186 species. Phytoplankton abundance were relatively high in May (C1, $726{\times}10^3cells\;L^{-1}$) and July (A1, $539{\times}10^3cells\;L^{-1}$). Total chlorophyll a and micro-size fraction ($>20{\mu}m$) increased at coastal stations in July and August, while phytoplankton abundance and total chl. a was much low in June. Dominant species in June was Pseudo-nitzschia spp. of which the cell size was $309{\mu}m^3$. Cell size of Pseudo-nitzschia spp. was smaller than dominant species in other period. Therefore, the increase in total chloro-phyll a and the size of phytoplankton was resulted in the sufficient supply of nutrients. In contrast, these tendencies were not observed at outside stations. These results suggested that coastal upwelling was an important influencing factor to determine the species composition and standing stock of phytoplankton community in the coastal waters of the Southern part of East Sea, Korea.

Subclavian-Brachial Bypass for Chronic Limb Threatening Ischemia Associated with an Old Motorcycle Accident

Jose I. Martínez-Quesada,Javier E. Anaya-Ayala,Santiago Mier y Terán-Ellis,Montserrat Miranda-Ramírez,Luis H. Arzola,Christopher Ruben-Castillo,Juan C. Aramburo,Jesus M. de los Ríos,Carlos A. Hinojosa 대한혈관외과학회 2022 Vascular Specialist International Vol.38 No.2

Chronic limb-threatening ischemia is rarely associated with previous traumatic injury. We present a case of a 28-year-old male with progressive digit ulcers, a weak pulse, cyanosis, and a cold limb. Eight months prior, he had a motorcycle accident resulting in a right clavicle fracture and brachial plexus injury. Computed tomography angiography revealed occlusion of the right subclavian artery near a surgically implanted reduction plate. The patient underwent an open subclavianbrachial bypass with a reversed saphenous vein graft. His postoperative recovery was uneventful. After 3 months, he had a euthermic right hand with a palpable pulse and his ulcers had completely healed. This case reinforces the need for patients with a neurological deficit in the upper extremity caused by blunt trauma to undergo thorough vascular examination to identify potential arterial injury and compromised perfusion.

Use of supercritical methanol/carbon dioxide mixtures for biodiesel production

María Belén García-Jarana,Jezabel Sánchez-Oneto,Juan Ramón Portela,Lourdes Casas,Casimiro Mantell,Enrique Martínez de la Ossa 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.8

The use of supercritical conditions for the production of biodiesel from both vegetables oils and waste-oils may be of great industrial interest because it can be carried out without those catalysts necessary in the conventional transesterification process, therefore avoiding a complex separation between the product and the catalyst. However, the use of supercritical alcohol requires higher operating temperatures and pressures. In this work, CO2 was added to the reaction mixture in order to reduce the operating conditions (temperature, pressure and molar ratio of alcohol to vegetable oil). The novelty of using CO2 may have two advantages: a possible combination of supercritical CO2 extraction of the oil and its subsequent transesterification reaction without CO2 depressurization, and a reduction of the supercritical temperature and pressure of the mixture. The effects of temperature (280-350 oC), pressure (140-280 bar), methanol- to-oil molar ratio (20-30), CO2-to-methanol molar ratio (0.05-0.2) and residence time (0-45minutes) on the yield of methyl esters (biodiesel) were studied in a batch reactor, obtaining in all cases a relatively low increase in the yield when CO2 was present in the medium. The yields of biodiesel were tested with three vegetable oils used as model compounds (palm, sunflower and borage), obtaining similar results.

Enteroparasitism and Risk Factors Associated with Clinical Manifestations in Children and Adults of Jalisco State in Western Mexico

María de la Luz Galván-Ramírez,Ana Luisa Madriz-Elisondo,Jorge de Jesús Romero Rameño,Dania Araceli de la O Carrasco,Marco Antonio Cardona López,Cynthia Guadalupe Temores Ramírez 질병관리본부 2019 Osong Public Health and Research Persptectives Vol.10 No.1

Objectives: To determine the prevalence and risk factors associated with intestinal parasites in the population of San Juan Cosala, Jalisco, Mexico. Methods: A total of 277 samples from 104 participants were analysed using direct smear, flotation, formaldehyde/ethyl acetate, and modified Kinyoun’s acid-fast stain methods. The Graham method was applied only for samples from children under 12 years of age for the diagnosis of Enterobius vermicularis. Results: The prevalence of parasite infections in the study population was 77.9% including: Entamoeba histolytica/E. dispar/E. moshkovskii/E. bangladeshi (37.5%), Giardia intestinalis (11.5%); commensals: Endolimax nana (44.2%), Entamoeba coli (27.9%), Chilomastix mesnili (6.7%) and Iodamoeba bütschlii, (2.9%); emerging intestinal protozoans: Blastocystis spp. (49%), Cryptosporidium spp. (7.7%) and Cyclospora cayetanensis (2.9%); and helminths: Enterobius vermicularis (18.3%) and Ascaris lumbricoides (5.8%). The results also showed that 58.64% of the studied population presented polyparasitism. A significant association was found between protozoan infections and housewives, and houses that were not built with concrete ceilings, brick walls and cement floors (p < 0.05). Conclusion: Polyparasitism was observed in over half the study population. The most prevalent parasite was Blastocystis spp, whilst the prevalence of helminths was less than that of protozoans. The risk factors for infection to intestinal parasites were being a housewife and not having solid brick, cement and concrete materials for house construction.