Stress-Charge Nonlinear Physical Description and Tensor Symmetries for Piezoelectric Materials.

Nonlinear piezoelectric materials are raised as a great replacement for devices that require low power consumption, high sensitivity, and accurate transduction, fitting with the demanding requirements of new technologies such as the Fifth-Generation of telecommunications (5G), the Internet of Things (IoT), and modern radio frequency (RF) applications. In this work, the state equations that correctly predict the nonlinear piezoelectric phenomena observed experimentally are presented. Furthermore, we developed a fast methodology to implement the state equations in the main FEM simulation software, allowing an easy design and characterization of this type of device, as the symmetry structures for high-order tensors are shown and explained. The operation regime of each high-order tensor is discussed and connected with the main nonlinear phenomena reported in the literature. Finally, to demonstrate our theoretical deductions, we used the experimental measurements, which presented the nonlinear effects, which were reproduced through simulations, obtaining maximum percent errors for the effective elasticity constants, relative effective permittivity, and resonance frequencies of 0.79%, 2.9%, and 0.3%, respectively, giving a proof of the potential of the nonlinear state equations presented for the unifying of all nonlinear phenomena observed in the piezoelectric devices.

Computational evaluation of rebreathing and effective dead space on a helmet-like interface during the COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) is a potentially severe acute respiratory infection caused by severe acute respiratory syndrome coronavirus 2. The potential for transmission of this disease has led to an important scarcity of health-care resources. Consequently, alternative solutions have been explored by many physicians and researchers. Non-invasive Ventilation has been revealed as one alternative for patients with associated acute respiratory distress syndrome. This technique is being used in combination with helmet-like interfaces because of their versatility and affordability. However, these interfaces could experience important problems of CO2 rebreathing, especially under low flow rate conditions. This work proposes a Computational Fluid Dynamics method to accurately characterize the fluid flow in a pre-design environment of helmet-like interfaces. Parameters as effective dead space, rebreathing, pressure, or temperature field distribution are quantified and analysed in detail in order to study the performance and feasibility of such devices to relieve the effects of respiratory infections.

[Patterns of antidemential drug use in a group of patients from Colombia]. / Patrones de uso de farmacos antidemencia en un grupo de pacientes de Colombia.

INTRODUCTION: The benefits of pharmacological therapy with anti-dementia drugs are not yet fully demonstrated and there is even a lack of publications describing their use profile. The present work sought to determine the prescription patterns of anti-dementia drugs in a Colombian population. PATIENTS AND METHODS: Descriptive cross-sectional study. Through a systematized database of 3.5 million affiliates to the Colombian health system, patients with uninterrupted dispensing of anti-dementia drugs between August-October/2016 were selected. Sociodemographic, pharmacological and comedication variables were analyzed. The costs of the therapies were estimated from the reference price of the medicines. RESULTS: We identified 8372 patients with a mean age of 79.5 ± 8.7 years and 65.3% (n = 5471) were women. The most widely used medication was rivastigmine (69.6%), mainly in transdermal presentation, followed by memantine (31.4%). In general, the average dose administered per day was lower than the defined daily dose. Only 568 patients (6.7%) used combination therapy. 84.3% of patients (n = 7061) used some additional medication and 54.2% (n = 4535) had another neurologic medication. The cost per 1000 inhabitants/day of rivastigmine was 3.47 USD and for memantine 0.30 USD. CONCLUSION: Patients with anti-dementia drugs are using them at doses lower than those defined and they present an important frequency of comorbidities and comedications.

TITLE: Patrones de uso de farmacos antidemencia en un grupo de pacientes de Colombia.Introduccion. Los beneficios del manejo farmacologico con medicamentos antidemencia aun no estan del todo demostrados, e incluso hay carencia de trabajos que describan su perfil de utilizacion. El presente trabajo busco determinar los patrones de prescripcion de farmacos antidemencia en una poblacion de Colombia. Pacientes y metodos. Estudio descriptivo de corte transversal. Mediante una base de datos sistematizada de 3,5 millones de afiliados al sistema de salud colombiano, se selecciono a pacientes con dispensaciones ininterrumpidas de farmacos antidemencia entre agosto y octubre de 2016. Se analizaron variables sociodemograficas, farmacologicas y comedicaciones. Se estimaron los costes de las terapias a partir del precio de referencia de los medicamentos. Resultados. Se identifico a 8.372 pacientes con una edad media de 79,5 ± 8,7 años; el 65,3% (n = 5.471) fueron mujeres. El farmaco mas utilizado fue la rivastigmina (69,6%), principalmente en presentacion transdermica, seguida de la memantina (31,4%). En general, la dosis media administrada por dia fue inferior a la dosis diaria definida. Solamente 568 pacientes (6,7%) usaron terapia combinada. El 84,3% de los pacientes (n = 7.061) uso medicamentos para alguna comorbilidad y el 54,2% (n = 4.535) tenia otro neurofarmaco. El coste por 1.000 habitantes/dia de la rivastigmina fue de 3,47 dolares, y de la memantina, de 0,30 dolares. Conclusion. Los pacientes con medicamentos antidemencia los estan empleando en dosis inferiores a las definidas y presentan una importante frecuencia de comorbilidades y comedicaciones.

Genotypification of the MSP3 Gene in patients with complicated Malaria / Genotypification of the MSP3 Gene in patients with complicated Malaria

Objetivo. Se estudió la diversidad genética de las poblaciones naturales de parásitos de Plasmodium vivax mediante el estudio de la región variable del gen Pvmsp-3α. Materiales y métodos. Se realizó PCR-RFLP en 29 muestras de pacientes con malaria por P. vivax con complicaciones (PC) y 32 pacientes con malaria por P. vivax sin complicaciones (PNC), todos los pacientes provenientes de la región Bajo-Córdoba-Uraba, zona altamente endémica para malaria. Fueron colectadas muestras de sangre total para la extracción de DNA utilizando la tecnica saponina/chelex-100. Se usó la tecnica de RFLP usando las enzimas de restricción HhAI y AluI. Diez patrones de restricción fácilmente distinguibles, se detectaron después que los productos de la PCR fueron digeridos con la enzima Alu I y 9 con la enzima Hha I. Resultados. El gen Pvmsp-3α exhibió gran polimorfismo y los resultados sugieren que este gen puede ser utilizado en Colombia como un marcador molecular epidemiológico para el genotipado de P. vivax, ademas el patron PH1con la enzima AluI mostró mayor frecencia en los pacientes complicados. Conclusiones. El gen Pvmsp3α puede ser un marcador genetico de variabilidad en las cepas circulantes de P. vivax y el PH1 sugiere ser un marcador para predecir una complicación en pacientes con malaria vivax.

Objective. The genetic diversity of the natural populations of Plasmodium vivax parasites was studied by studying the variable region ofthe Pvmsp-3α gene. Materials and methods. PCR-RFLP was performed in 29 samples of patients with P. vivax malaria with complications (PC) and 32 patients with P. vivax malaria with out complications (PNC), all patients from the Bajo-Córdoba-Uraba region, Highly endemicto malaria. Total blood samples were collected for DNA extraction using the saponin /chelex-100 technique. The RFLP technique was used using there striction en zymes HhA Iand AluI. Teneasily distinguis hablere striction patterns were detected after the PCR products were digested with the enzyme Alu I and 9 with the enzyme Hha I. Results. The Pvmsp-3α gene exhibited large polymorphismand the results suggest that this gene can be used in Colombia asa moleculare pidemiological marker for the genotypin go fP. vivax. Further more, the PH1 pattern with the AluIen zyme showed higher frequency in the complicated patients. Conclusions. The Pvmsp3 gene may be agenetic marker of variability in the circulating strain so fP. vivax and the PH1 suggest samarker for predicting a complication in patients with vivax malaria.

Chemically induced hypoxia promotes differential outcomes over preadipocyte- or adipocyte-macrophage communication.

Expansion of white adipose tissue induce insufficient vascularization, driving hypoxia and low-grade inflammation. Resident preadipocytes are thought to be involved. We evaluated the effects of hypoxia over preadipocytes and adipocytes, to determine which cellular type impacts the most over macrophages activation. 3T3-L1 cells were either differentiated, or maintained undifferentiated. Each group was subjected to the presence or absence of chemical hypoxia (200 µM CoCl2) for 24 h. Conditioned media were used as treatment for murine RAW264.7 macrophages for 24 h. Gene expression of HIF-1α and TNF-α, and the release of several markers were assessed. It was observed that culture media from hypoxic preadipocytes induced greater expression of inflammatory markers and NO release than culture media from hypoxic adipocytes, by macrophages. Gene expression correlated closer with inflammatory markers release specially on macrophages treated with conditioned media from preadipocytes. Hence, the present work highlights the importance of preadipocytes on inflammatory conditions in vitro.

Effects of hyperoxia exposure on metabolic markers and gene expression in 3T3-L1 adipocytes

Adipose tissue often becomes poorly oxygenated in obese subjects. This feature may provide cellular mechanisms involving chronic inflammation processes such as the release of pro-inflammatory cytokines and macrophage infiltration. In this context, the purpose of the present study was to determine whether a hyperoxia exposure on mature adipocytes may influence the expression of some adipokines and involve favorable changes in specific metabolic variables. Thus, 3T3-L1 adipocytes (14 days differentiated) were treated with 95 % oxygen for 24 h. Cell viability, intra and extracellular reactive oxygen species (ROS) content, glucose uptake, as well as lactate and glycerol concentrations were measured in the culture media. Also, mRNA levels of hypoxia-inducible factor (HIF)-1á, leptin, interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, peroxisome proliferator-activated receptor (PPAR)-Gamma, adiponectin, and angiopoietin-related protein (ANGPTL)4 were analyzed. Hyperoxia treatment increased intra and extracellular ROS content, reduced glucose uptake and lactate release and increased glycerol release. Additionally, a higher oxygen tension led to an upregulation of the expression of IL-6, MCP-1, and PPAR-Gamma, while ANGPTL4 was downregulated in the hyperoxia group with respect to control. The present data shows that hyperoxia treatment seems to produce an inflammatory response due to the release of ROS and the upregulation of pro-inflammatory adipokines, such as IL-6 and MCP-1. On the other hand, hyperoxia may have an indirect effect on insulin sensitivity due to the upregulation of PPAR-Gamma signaling as well as a possible modulation of both glucose and lipid metabolic markers. To our knowledge, this is the first study analyzing the effect of hyperoxia in 3T3-L1 adipocytes (AU)

Influence of different oxygen supply on metabolic markers and gene response in murine adipocytes.

Obese subjects often present a low-grade chronic inflammation in the white adipose tissue, which seems to play an important role in the initiation and development of obesity-related diseases. It has been reported that this inflammatory process may be due to a hypoxic state occuring within this tissue. Oxygen is used in current medicine as a treatment for several conditions. The aim of this study is to analyze the effects of 95 percent O2 on specific metabolic variables and on the expression of some genes on murine adipocytes. 3T3-L1 adipocytes were exposed during 48 h to different treatments: 95 percent O2 hyperoxia (HPx group), CoCl2 (CoCl2 group), hyperoxia with CoCl2 (HPx+CoCl2 group) and 1 percent O2 hypoxia (Hx group). Cell viability, intracellular ROS content, glucose utilization, lactate and glycerol concentrations were measured. Also, mRNA expression of HIF-1alpha, GLUT-1, ANGPTL4, PPAR-gamma, adiponectin, IL-6 and MCP-1 genes was analyzed. Importantly, 95 percent O2 decreased cell viability and increased intracellular ROS production. Also, glycerol and lactate release were significantly increased and decreased, respectively, in HPx treated cells. This treatment also provoked a down-regulation of GLUT-1 and ANGPTL-4, while IL-6 and MCP-1 were up-regulated. Exposure to a hyperoxia of 95 percent O2 provoked an inflammatory response in adipocytes. The two hypoxia-inducing conditions (CoCl2 and 1 percent O2) produced different outcomes in metabolic measurements as well as in the expression of some genes (GLUT-1, ANPGTL4, PPAR-gamma and adiponectin), while it remained similar in others (HIF-1alpha, IL-6 and MCP-1). Indeed, hyperoxia increased significantly the ROS levels and the lipolytic activity, while it reduced lactate production. In addition to the effects on inflammation, the changes in GLUT-1, ANGPTL4 and PPAR-gamma genes lead to suppose that hyperoxia may be beneficial for the hypertrophied adipose tissues of obese subjects and for improving insulin sensitivity.

[Morbidity and mortality in a series of patients suffering from intraperitoneal neoplasia treated with peritoneal cytoreduction and hyperthermic intraperitoneal chemotherapy at the Fundación Santa Fe de Bogotá Teaching Hospital (ONCOLGroup--ATIA study)]. / Morbilidad y mortalidad en una serie de pacientes con neoplasias del peritoneo, tratados con citorreducción peritoneal más quimioterapia hipertérmica intraperitoneal en el Hospital Universitario de la Fundación Santa Fe de Bogotá (ONCOLGroup--estudio ATIA).

BACKGROUND: The procedure of radical peritonectomy followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is considered the standard treatment for peritoneal cancers. AIMS: To evaluate various outcomes in a cohort of patients with peritoneal tumors treated with HIPEC. METHODS: Twenty-four patients consecutively treated with radical peritonectomy plus HIPEC within the time frame of November 2007 to July 2010 were enrolled; 15 (62%) had tumors of appendicular origin, 4 (16.7%) had primary peritoneal tumors, 2 had ovarian carcinomas and there was one case of colon cancer, one carcinosarcoma and one hemangioendothelioma. Mean age was 53 years (range: 26-68) and median follow-up was 14.2 months (range: 1-32). Demographic data, histology, peritoneal cancer index (PCI), surgical procedure characteristics, recurrence-free survival (RFS), and overall survival (OS) were all evaluated. Short-term morbidity and mortality were also determined. RESULTS: Complete cytoreduction was achieved in 18 patients (75%). Mean PCI was 15 (<10: 41% and >10: 58%), and the median (range) for surgery duration, length of stay in the Intensive Care Unit, parenteral nutritional support, and hospital stay were 12,5 (7-20) hours, 11,4 (2-74) days, 13,8 (12-65) days, and 29,1 (10-90) days, respectively. One patient (4%) died 6 months after the procedure, due to multiple associated complications. Considerable morbidity was seen in 52% of cases, including thromboembolic events (41%), catheter-related bacteremia (29%), fistulas (29%), and nephrotoxicity (25%). Six patients (25%) recurred after a median of 21 months of RFS. CONCLUSIONS: Cytoreductive surgery plus HIPEC in well-selected patients presenting with tumors that affect the peritoneum is a procedure that can be carried out in Colombia with an adequate safety and effectiveness profile. Mortality was similar to that reported in the international literature.

Effects of hyperoxia exposure on metabolic markers and gene expression in 3T3-L1 adipocytes.

Adipose tissue often becomes poorly oxygenated in obese subjects. This feature may provide cellular mechanisms involving chronic inflammation processes such as the release of pro-inflammatory cytokines and macrophage infiltration. In this context, the purpose of the present study was to determine whether a hyperoxia exposure on mature adipocytes may influence the expression of some adipokines and involve favorable changes in specific metabolic variables. Thus, 3T3-L1 adipocytes (14 days differentiated) were treated with 95 % oxygen for 24 h. Cell viability, intra and extracellular reactive oxygen species (ROS) content, glucose uptake, as well as lactate and glycerol concentrations were measured in the culture media. Also, mRNA levels of hypoxia-inducible factor (HIF)-1α, leptin, interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, peroxisome proliferator-activated receptor (PPAR)-γ, adiponectin, and angiopoietin-related protein (ANGPTL)4 were analyzed. Hyperoxia treatment increased intra and extracellular ROS content, reduced glucose uptake and lactate release and increased glycerol release. Additionally, a higher oxygen tension led to an upregulation of the expression of IL-6, MCP-1, and PPAR-γ, while ANGPTL4 was downregulated in the hyperoxia group with respect to control. The present data shows that hyperoxia treatment seems to produce an inflammatory response due to the release of ROS and the upregulation of pro-inflammatory adipokines, such as IL-6 and MCP-1. On the other hand, hyperoxia may have an indirect effect on insulin sensitivity due to the upregulation of PPAR-γ signaling as well as a possible modulation of both glucose and lipid metabolic markers. To our knowledge, this is the first study analyzing the effect of hyperoxia in 3T3-L1 adipocytes.

Impact of oxygen availability on body weight management.

Obesity is nowadays a major public health problem. The World Health Organization reported that globally 400 million adults are obese, and the situation seems to raise in the future. Furthermore, obesity is a major risk factor for a number of chronic diseases such as type 2 diabetes, cardiovascular diseases and the metabolic syndrome. Interestingly, several studies have reported that appetite suppression and body weight loss are frequently observed at high altitude. This observation has opened some possibilities for losing weight under hypoxia or living in altitude. Nevertheless, the triggering mechanisms for the decrease in energy intake in hypoxic conditions still remain unclear as well as the impact on body mass components. On the other hand, obese subjects often present a chronic inflammatory state on the adipose tissue that might have a strong relationship with onset and development of obesity-related diseases. Thus, it has been consistently reported that adipose tissue of obese subjects is poorly oxygenated and that this hypoxia state is a new potential risk factor for the chronic inflammation in obesity. In this sense, oxygen therapy is a common technique used in current medicine for the treatment of several diseases, while animal studies have demonstrated that treatment with hyperoxia produces some beneficial effects in different diseases related with lack of oxygen in several organs. In this article, we review the role of oxygen availability in body weight homeostasis and hypothesize the possible applicability of hypoxia and hyperoxia for the treatment of obesity and related disorders.

Condiciones higiénico-sanitarias como factores de riesgo para las parasitosis intestinales en una comunidad rural venezolana / Sanitary conditions as risk factors for intestinal parasites in a rural community in venezuelan

Las parasitosis intestinales, enfermedades tropicales desasistidas, contribuyen con el ciclo de la pobreza en poblaciones rurales, con acceso limitado a la atención médica, malas condiciones higiénicas, con consumo de agua y alimentos contaminados. El propósito de este estudio de prevalencia, muestra no aleatoria de 69 niños, fue evaluar los factores de riesgo higiénico-sanitarios mediante inspección, las normas de disposición de residuos sólidos y manipulación de alimentos en la Unidad Educativa de Panaquire-Miranda, ejecutar encuesta sobre las condiciones de vida, examinar muestras de heces mediante el método Formol-Tritón-Éter y asociar las condiciones higiénico-sanitarias de la vivienda con la presencia de parasitosis. La disposición de residuos y manipulación de alimentos fue insatisfactoria según los parámetros validados por los inspectores de salud a nivel nacional. Diecinueve por ciento de los encuestados sin acceso al agua peridomiciliaria, 17% viven en ranchos y 10% disponen sus excretas a cielo abierto. Casi 60% de las muestras fueron positivas para mono o poliparasitosis. Las infecciones por helmintos con alta prevalencia (73,5%), mmás frecuente la Trichuris trichiura (34,4%). Se encontró una asociación causal entre la defecación a campo abierto y la infección por Áscaris lumbricoides (Odds Ratio OR=8; IC 95%:1,27–50; p=0,03) y Trichuris trichiura (OR=14; IC 95%:1,51–133,4; p=0,01). Los hallazgos refuerzan la necesidad de políticas de salud para mejorar las condiciones higiénico-sanitarias en las comunidades rurales y proteger la salud pública.

Intestinal parasites, neglected tropical diseases, contribute to the cycle of poverty in rural populations with limited access to medical care and unhygienic conditions, coupled with the consumption of contaminated food and water. Prevalence study which involved 69 children, to evaluate through inspection, standards for solid waste disposal and food handling in the Panaquire-Miranda school unit, sanitation and hygiene life conditions obtained by the participant survey, examine fecal samples of participants using the method formaldehyde-Triton-ether and associate sanitary conditions of housing with the presence of parasites. Waste, water and food management handling were unsatisfactory according to official parameters validated by health inspectors. Nineteen percent of participants do not have access to water, 17% live on poor housing and 10% have their excreta in the open field. Nearly 60% of stool samples were positive for mono or poliparasitosis. Helminthes infections were highly prevalent (73.5%) and Trichuris trichiura (34.4%) most frequent. The results showed a positive correlation between open field defecation and infection with Ascaris lumbricoides (Odds Ratio OR=8; 95%CI=1.27-50, p=0.03) and Trichuris trichiura(OR=14 95%CI=1.51-133.4, p=0.01). These findings reinforce the need for political action to improve sanitary conditions in rural communities and protect public health.

Comportamiento epidemiológico de la coinfección virus de hepatitis B y virus hepatitis C con el virus de inmunodeficiencia humana / Epidemiological pattern of co-infection of hepatitis B virus and hepatitis C virus with human immunodeficiency virus

Los riesgos epidemiológicos compartidos por el VIII, y los virus de hepatitis B (VHB) y C (VHC), explican el aumento de prevalencia de VIH-VHB-VHC. Evaluar comportamiento clínico y epidemiológico de la co-infección VHI-VHB-VHC. Retrospectivo, descriptivo, correlacional. Se registraron datos de marcadores de VHB y VHC, función hepática, antecedentes epidemiológicos y síntomas. Universo 816 casos, 268 excluidos, muestra definitiva 548 casos, 91,39 por ciento sexo masculino, 8,61 por ciento femenino. Grupo más afectado: 36-50 años. El 27,37 por ciento resultó positivo para hepatitis B, 3,83 por ciento para hepatitis C, y 15,14 por ciento para Anticore 0,72 por ciento reportaron coinfección VIH-VHB-VHC Tasa de Incidencia en 2 años: 0,17 y 0,02 para VIH-VHB y VII1-VCH respectivamente. Pacientes positivos para VFIB: 72 por ciento evoluciono hacia la resolución y 18 por ciento hacia la cronicidad. Pacientes positivos para VIIC: 9,52 por ciento hizo inmunidad y 90,48 por ciento infección crónica, 19 por ciento con genotipo la y 9,52 por ciento con genotipo lb. De los cuales 50 por ciento tienen cargas virales detectables. Antecedentes epidemiológicos: consumo de drogas fue determinante para VHC (P=0,0042) y EST para VHS (P=0,032). Las transaminasas y los síntomas clínicos no mostraron diferencia significativa entre VHB y VHC. La presencia de VIII-VI-IB es más alta que la reportada por la literatura, pero la de VHC es menor. El comportamiento clínico y los antecedentes epidemiológicos de VIH-VHB- y VIH-VHC son similares a los documentados en otras localidades. Los pacientes con Anticore + deben evaluarse para la reactivación o falta de inmunidad de la infección. El genotipo 1 es frecuente en VIH-VCH. El 70 por ciento de los pacientes requieren vacunación para prevenir VHS.

[Evaluation of 100 melanomas of the choroid and ciliary body treated by application of ruthenium (RU 106 Rh 106)]. / Bilan de 100 mélanomes de la choroïde et du corps ciliaire traités par applicateur de ruthénium (RU 106 Rh 106).

100 cases of uveal melanomas, were treated with 106 RU 106 RH beta-brachytherapy, between June 1983 and September 1987. 82 eyes having a follow-up superior or equal to 6 months, were analysed. 13 of these 82 eyes have been enucleated. 2 patients, have died, 2 have at this time, hepatic dissemination. The first 43 patients were analysed at the 18th month after irradiation. The majority of tumors with initial thickness inferior to 5 mm had a regression superior to 50%, at the 18th month. The majority of tumors with initial thickness superior to 5 mm, had a regression inferior to 50%, at the same time. Functional results have also been noticed in this series of 43 eyes, and were satisfactory.

Autolysis induction of malignant lymphoblasts.

BALB/C mice were treated with epsilon aminocaproic acid (EACA), 0.1 to 3.2 mg/g body weight, subcutaneously every 24 hours for six days, starting on the second day after intraperitoneal transplantation of L5178Y lymphoma. Complete involution was observed in 20 to 90 per cent of the ascitic tumor and in 50 per cent of the solid tumor 72 hours after EACA was discontinued, tumoral involution and dosage were directly proportional. One hundred per cent of the non treated controls died 10 +/- 0.6 days after intraperitoneal lymphoma transplantation. During tumor involution malignant cells underwent autolysis and were attacked or phagocytized by activated macrophages. Since EACA is a proteolytic enzyme inhibitor, inhibition during treatment and activation of these enzymes after EACA was discontinued could have been the cause of autolysis of the L5178Y lymphoma cells.

[Immunogenicity of L5178Y cells modified by different reagents]. / Inmunogenicidad del las células L5178Y modificadas con diferentes reactivos.

Lymphoma L5178Y cells were treated with neuraminidase of Vibrio cholerae, potassium iodine, dithiotreitol (DTT), mercaptoethanol, glutaraldehyde, iodoacetamide, merthiolate, sodium periodate, urea, papaine, trypsine and EDTA, to increase immunoreaction in tumor cells. Mice were immunized with modified tumor cells every week for one month. Thereafter non modified tumor cells were transplanted to previously immunized mice. Only the immunization with neuraminidase-treated cells rejected the tumor. Although the immunization with cells treated with potassium iodine, DTT and mercaptoethanol did not reject tumor, prolonged significantly span of life. The other reactives had neither effect on tumor rejection nor on span of life.

[A new technic for LE cell formation. Preliminary report]. / Formación de células L.E. por un nuevo procedimiento. Communicación preliminar

In special designed vials using coverslides glued to segments of polyethilene test tubes of 0.15 ml of fibrin free blood were incubated during 45 min to 37 degrees C in a humid chamber. Blood samples were obtained from patients with disseminated Lupus erythematosus (DLE) and normal subjects (N). Adhered polymorpho-nuclear cells (PNC) to glass were washed with Hank's solution; immediately 0.15 ml of DLE or N serum containing 5X10(6) lymphocytes (L) were added to culture cells and incubated at 37 degrees C during 30 min. Lymphocytes were previously incubated at 37 degrees C during 30 min with either N serum or DLE serum. Thereafter the segment of polyethilene test tube was detached from coverslides and cells attached to glass was washed with Hank's solution and stained with Wright solution. PMN of DLE and N in presence of L of DLE and N incubated with fresh serum of DLE formed 5 to 15% of LE cells. Determining factor for LE cells formation is the serum of DLE. Slides contained only PMN and LE cells which make easy the observation of results. All possible combinations with PMN and DLE serum and N serum allowed inclusion of several negative or positive control groups.