Yin-Yang-1 decreases Fas-induced apoptosis in acute lymphoblastic leukemia under hypoxic conditions: its implications in immune evasion / YY1 induce la disminución de la apoptosis a través de Fas en la leucemia linfoblástica aguda en condiciones hipóxicas: implicaciones en la evasión de la respuesta inmunitaria

Abstract Background: Acute lymphoblastic leukemia (ALL) is an aggressive malignant disease with high prevalence in pediatric patients. It has been shown that the downregulation of Fas expression is correlated with an inadequate response in ALL, although these mechanisms are still not well understood. Several reports demonstrated that hypoxia is involved in dysfunctional apoptosis. Yin-Yang-1 (YY1) transcription factor is involved in resistance to apoptosis, tumor progression, and it is increased in different types of cancer, including leukemia. The regulatory mechanism underlying YY1 expression in leukemia is still not understood, but it is known that YY1 negatively regulates Fas expression. The study aimed to evaluate the effect of YY1 on Fas expression under hypoxic conditions in ALL. Methods: Leukemia cell line RS4; 11 was cultured under normoxic and hypoxic conditions. YY1, Fas receptor, and hypoxia-inducible factor (HIF-1α) expression were analyzed. After treatment with a Fas agonist (DX2), apoptosis was analyzed through the detection of active caspase 3. Data were analyzed using Pearson’s correlation. Results: Leukemia cells co-expressed both HIF-1α and YY1 under hypoxia, which correlated with a downregulation of Fas expression. During hypoxia, the levels of apoptosis diminished after DX2 treatment. The analysis revealed that patients with high levels of HIF-1α also express high levels of YY1 and low levels of Fas. Conclusions: These results suggest that YY1 negatively regulates the expression of the Fas receptor, which could be involved in the escape of leukemic cells from the immune response contributing to the ALL pathogenesis.

Resumen Introducción: La leucemia linfoblástica aguda (LLA) es una enfermedad con alta prevalencia en la población pediátrica. El mecanismo por el cual el receptor de Fas participa en la regulación inmunitaria en los tumores es desconocido, pero se sabe que está subexpresado en LLA. El factor de transcripción Ying-Yang-1 (YY1) está involucrado en la resistencia a la apoptosis y la progresión tumoral; se encuentra aumentado en diferentes tumores, incluida la LLA. Aunque los mecanismos que regulan la expresión de YY1 en LLA son desconocidos, se sabe que YY1 regula la expresión del receptor de Fas. El objetivo de este trabajo fue evaluar el efecto de YY1 en la expresión de Fas en condiciones de hipoxia en la LLA. Métodos: Se cultivaron células RS4;11 en condiciones de hipoxia y se analizó la expresión de YY1, receptor de Fas y HIF-1α. La apoptosis fue inducida usando un agonista de Fas (DX2) y se analizó con la detección de caspasa 3 activa. Los datos se analizaron mediante correlación de Pearson. Resultados: Las células RS4;11 coexpresaron HIF-1αy YY1 en hipoxia, lo cual correlaciona con una baja expresión de Fas. La apoptosis se encontró disminuida durante condiciones de hipoxia, después del tratamiento con DX2. El análisis bioinformático mostró que los pacientes con altos niveles de HIF-1αpresentan YY1 elevado y bajos niveles del receptor de Fas. Conclusiones: Estos resultados sugieren que YY1 regula negativamente la expresión del receptor de Fas, lo cual podría estar involucrado en el escape de las células leucémicas a la respuesta inmunitaria, contribuyendo a la patogénesis de la LLA.

Classificação de risco de transmissão de doenças imunopreveníveis a partir de indicadores de coberturas vacinais nos municípios brasileiros / Clasificación de riesgo de transmisión de enfermedades prevenibles a partir de indicadores de cobertura de vacunación en municipios / Classification of transmission risk of vaccine-preventable diseases based on vaccination indicators in Brazilian municipalities

OBJETIVO: descrever a classificação de risco de doenças imunopreveníveis nos municípios brasileiros. MÉTODOS: estudo epidemiológico descritivo com dados do Sistema de Informações do Programa Nacional de Imunizações (SI-PNI) para 2014; os indicadores de coberturas vacinais foram utilizados para classificar o risco de transmissão de doenças imunopreveníveis nos municípios. RESULTADOS: dos 5.570 municípios brasileiros, 12,0% foram classificados como de risco muito baixo, 29,6% de risco baixo, 2,2% de risco médio, 54,3% de risco alto e 1,8% de risco muito alto. CONCLUSÃO: a vigilância das coberturas vacinais permitiu identificar a maioria dos municípios em situação de alto risco e a minoria das crianças vivendo em municípios com cobertura adequada; a vigilância das coberturas utilizando indicadores pactuados no Sistema Único de Saúde (SUS) oferece nova ferramenta para identificação de áreas prioritárias, onde as ações poderão ter maiores chances de acerto pelos gestores e melhorar a qualidade e o sucesso do PNI.

OBJETIVO: describir la clasificación de riesgo de enfermedades prevenibles en municipios brasileños. MÉTODOS: estudio epidemiológico descriptivo con datos del Sistema de informaciones del programa nacional de inmunizaciones (PNI) de 2014; los indicadores de cobertura fueron utilizados para clasificar el riesgo de transmisión de enfermedades prevenibles en los municipios. RESULTADOS: de los 5.570 municipios brasileños, 12,0% fueron clasificados de muy bajo riesgo, 29,6% de bajo riesgo, 2,2% de riesgo medio, 54,3% de alto riesgo y 1,8% de riesgo muy alto. CONCLUSIÓN: la vigilancia de la cobertura de vacunación permitió identificar la mayoría de los municipios en situaciones de alto riesgo y la minoría de niños que viven en municipios con una cobertura adecuada; la vigilancia de la cobertura de vacunación según indicadores acordados en el sistema de salud pública ofrece una nueva herramienta para la identificación de áreas prioritarias en las que la acción pueda tener mayores posibilidades de éxito por los administradores de salud para mejorar la calidad y el éxito del programa de inmunización.

OBJECTIVE: to describe the transmission risk classification of vaccine-preventable diseases in Brazilian municipalities. METHODS: this was a descriptive epidemiologic study using 2014 data of the Brazilian National Immunization Program Information System; the vaccine coverage indicators were used to classify the transmission risk of vaccine-preventable diseases in the municipalities. RESULTS: of the 5,570 Brazilian municipalities, 12.0% were classified as very low risk, 29.6% as low risk, 2.2% as medium risk, 54.3% as high risk and 1.8% as very high risk. CONCLUSION: the vaccination coverage surveillance allowed to identify most of the municipalities in high risk situation and the minority of children living in municipalities with appropriate coverage; the vaccination coverage surveillance using indicators of the Brazilian National Health System (SUS) is a new tool for identifying priority areas where the actions can be more successful for health managers and improve the quality and the success of the immunizations program.

Research progress of ursolic acid's anti-tumor actions / 中国结合医学杂志

Ursolic acid (UA) is a sort of pentacyclic triterpenoid carboxylic acid purified from natural plant. UA has a series of biological effects such as sedative, anti-inflammatory, anti-bacterial, anti-diabetic, antiulcer, etc. It is discovered that UA has a broad-spectrum anti-tumor effect in recent years, which has attracted more and more scholars' attention. This review explained anti-tumor actions of UA, including (1) the protection of cells' DNA from different damages; (2) the anti-tumor cell proliferation by the inhibition of epidermal growth factor receptor/mitogen-activated protein kinase signal or of FoxM1 transcription factors, respectively; (3) antiangiogenesis, (4) the immunological surveillance to tumors; (5) the inhibition of tumor cell migration and invasion; (6) the effect of UA on caspase, cytochromes C, nuclear factor kappa B, cyclooxygenase, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or mammalian target of rapamycin signal to induce tumor cell apoptosis respectively, and etc. Moreover, UA has selective toxicity to tumor cells, basically no effect on normal cells. With further studies, UA would be one of the potential anti-tumor agents.

Cavidad oral: importante sitio de vigilancia inmunológica / Oral cavity: important site for immune surveillance

La cavidad oral es el principio del tracto digestivo y uno de los sitios del cuerpo más expuestos al ingreso de todo tipo de patógenos, tanto del aire como de los alimentos. Aunque varios excelentes artículos han examinado distintos aspectos de tejidos linfoides asociados a mucosas (MALT), no hay suficiente información acerca de la respuesta inmune en la cavidad oral. En esta revisión destacamos algunos aspectos sobre la anatomía / histología de la cavidad oral, estructuras asociadas y células o moléculas con crucial función inmunológica contra antígenos que ingresan en la boca. Los estudios sobre la mucosa oral han adquirido mucha notoriedad últimamente debido a que ofrece una excelente accesibilidad y evita la degradación de las proteínas y péptidos. En la cavidad bucal se puede generar una respuesta inmune apropiada contra microorganismos, en donde además de la IgA salival muchas otras moléculas son liberadas y cumplen un rol protagónico. A pesar de todos estos factores de defensa, existen momentos en donde el individuo se encuentra más expuesto, dependiendo de la edad, factores hormonales, genéticos, hábitos de fumar y la actividad física, ya que todo esto modifica la tasa de flujo salival, tasa de secreción y concentración de IgA salival y demás proteínas. (AU)

The oral cavity is the beginning of the digestive tract and one of the most exposed body sites to the entry of all types of pathogens in the air as food. Although several excellent articles have examined various aspects of mucosa-associated lymphoid tissue (MALT), there is insufficient information about the oral cavity immune response. In this review we highlight some aspects of the anatomy / histology of the oral cavity, associated structures and cells or molecules with crucial immunological function against antigens that enter the mouth. Studies on the oral mucosa have gained much notoriety lately because it offers excellent accessibility and prevents the degradation of proteins and peptides. In the oral cavity can generate an appropriate immune response against microorganisms, where salivary IgA in addition to many other molecules are released and play a role. Despite these defense factors, there are moments where the individual is more exposed, depending on age, hormonal factors, genetic, smoking habits and physical activity, and that this changes the rate of salivary flow rate secretion and concentration of salivary IgA and other proteins.(AU)

Evaluación internacional del Programa Ampliado de Inmunizacipon de Bolivia 2010: informe final / International Assessment of Expanded Programme of Bolivia Inmunizacipon 2010: final report

Determinar la capacidad instalada y necesidades del PAI, para que responda a desafios de mantener la erradicación, eliminación y control de enfermedades prevenibles por vacunación.

Câncer e o microambiente tumoral / Cancer and the tumor microenvironment

Antes tido como um conjunto de células alteradas em proliferação, hoje o cânceré mais bem entendido como um microambiente, em que as interações entre os elementos celulares e moleculares que o compõem são determinantes na progressão tumoral. Como resultado, a compreensão do evento neoplásico ganha complexidade crescente. A dinâmica das células tumorais passa a ser avaliada como parte de um verdadeiro tecido tumoral, sujeita a condições de vascularização, de oxigenação, de pressão intersticial e de necrose tecidual, que influenciam na cinética tumoral. Estão sendo identificados novos componentes deste nicho tumoral e as suas respectivas atuações. Entre esses integrantes, encontram-se os elementos da imunidade, cuja modulação tem sido demonstrada por uma série de pesquisas aqui revisadas, tanto no sentido da vigilância imunológica, como pressão seletiva negativa, quanto nofavorecimento da progressão tumoral. Esta revisão analisará a neoplasia do ponto de vista de um microambiente tumoral, focando na participação imunológica e na cinética tumoral, expondo as principais idéias e descobertas que criaram e estão aperfeiçoando o conceito de câncer.

Formerly referred to as a group of altered cells in proliferation, today cancer is better understood as a microenvironment, in which the interactions between the cellular andmolecular elements are determinative in tumor progression. As a result, the comprehension of a neoplasic event gains increasing complexity. The dynamics of the tumor cells are nowanalyzed as part of a true tumoral tissue, subject to conditions of vascularization, oxygenation, interstitial pressure and tissue necrosis, which influence tumor kinetics. New components of this tumoral niche and their respective actions are being identified. Among these constituentsare the elements of the immune system which, as a series of experiments have shown, are involved in the aspect of immunosurveillance, as negative selective pressure, as well as inmechanisms of tumor progression. This review will analyze neoplasia as a tumor microenvironment, focusing on immunological participation and on tumor kinetics, and exposing the mainideas and discoveries that created and are improving the concept of cancer.

Correlation of Fas/FasL expression to cell apoptosis in Epstein-Barr virus-associated gastric carcinoma / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>Epstein-Barr virus (EBV) has been detected in about 10% of gastric carcinomas. However, the pathogenetic role of EBV in gastric carcinoma is uncertain. This study was to explore the correlation of Fas/FasL expression to the apoptosis of tumor cells and tumor-infiltrating lymphocytes (TIL) in EBV-associated gastric carcinoma (EBVaGC).</p><p><b>METHODS</b>Fas/FasL expression in 49 specimens of EBVaGC, 20 specimens of EBV-negative gastric carcinoma (EBVnGC) and 12 specimens of normal gastric mucosa was detected by immunohistochemistry. The apoptotic index (AI) of cells was determined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL).</p><p><b>RESULTS</b>The positive rates of Fas were 91.7% in normal gastric mucosa and 76.8% in gastric carcinoma (P < 0.05); those of FasL were 16.7% in normal gastric mucosa and 58% in gastric carcinoma (P < 0.05). The positive rate of Fas was significantly lower in EBVaGC than in EBVnGC (71.4% vs. 90.0%, P < 0.05). The positive rate of FasL in EBVaGC was significantly higher than that in EBVnGC (63.2% vs. 45%, P < 0.05). The AI of EBVaGC cells was significantly lower than that of EBVnGC cells (P = 0.002). The number and AI of TIL in EBVaGC were higher than those in EBVnGC (P < 0.05). The AI of TIL was positively correlated with the level of FasL expression in tumor cells (r=0.237, P = 0.028).</p><p><b>CONCLUSION</b>Up-regulation of FasL expression and decrease of TIL apoptosis in EBVaGC may facilitate the escape of tumor cells from the host immunosurveillance, and it might contribute to the development and progression of carcinoma.</p>

A Case of Kaposi's Sarcoma with Concomitant Colon Cancer / 대한피부과학회지

Kaposi's sarcoma may be associated with other neoplasm, and this may indicate that Kaposi's sarcoma is related with altered immunologic surveillance. There has been only one reported case of Kaposi's sarcoma with concomitant pancreatic cancer in Korea, but Kaposi's sarcoma with concomitant colon cancer has not been reported in Korea. We report here on a case of Kaposi's sarcoma with concomitant colon cancer in an 82-year-old Korean woman who had no other evidence of immunosuppression.

Células natural killer e vigilância imunológica: [revisão] / Natural killer cells and immune surveillance: [review]

OBJETIVOS: Analisar a importância das células natural killer, de seus receptores killer immunoglobulin-like receptors e correspondentes genes (KIR) na vigilância imunológica do organismo contra agentes infecciosos, transplantes de células-tronco hematopoiéticas, assim como sua participação na auto-imunidade. As características e o polimorfismo dos genes e receptores KIR na população brasileira serão descritos. FONTES DOS DADOS: Livros, artigos de revisão e artigos científicos recentes são citados e listados na bibliografia. A experiência pessoal é também apresentada. SÍNTESE DOS DADOS: Identificamos o perfil de genes e haplótipos KIR na população caucasóide brasileira, sendo de importância esse conhecimento para a análise da relação desse sistema com doenças. Examinamos 116 indivíduos doadores voluntários de medula óssea, identificando-se 32 genótipos e a presença de 51 e 49 por cento de haplótipos A e B, respectivamente. Foi realizado estudo comparativo entre os nossos genótipos e os de outras populações. CONCLUSÕES: A imunidade inata é uma barreira antiinfecciosa de importância em pediatria. Ela atua de maneira independente da imunidade celular e humoral, sendo mais rápida que as demais fontes de proteção do organismo. Ao mesmo tempo, ela estimula os linfócitos T CD8 a agirem e amplificarem a rede de proteção imunológica. Entretanto, como na maioria das vezes em que a imunidade atua, ela também pode ser prejudicial, agredindo o organismo por mecanismos auto-imunes ou mesmo, na sua ausência, oferecer espaço aos agentes infecciosos para agirem de forma impune.

OBJECTIVES: To analyze the importance of natural killer cells, their killer immunoglobulin-like receptors (KIR) and genes in autoimmunity and in the immune surveillance against infectious agents and stem cells transplantation. The characteristics and polymorphisms of the KIR genes and receptors in the Brazilian population is described. SOURCES: Textbooks, review articles and recent scientific articles are cited and listed in the references. SUMMARY OF THE FINDINGS: KIR genes and haplotypes within a Brazilian Caucasian population were surveyed and analyzed to assess the future relationship of this system with diseases. Of 116 voluntary bone marrow donors, we identified 32 genotypes with frequencies of A and B haplotypes of 51 and 49 percent, respectively. A comparative analysis was performed between these genotypes and those from other populations. CONCLUSIONS: Innate immunity is an important anti-infectious barrier in newborns. It is independent of both cellular and humoral immunity, can be faster and confers great advantage in early age. At the same time, it stimulates CD8 T lymphocytes to act and amplify the immunological protection network. Nevertheless, as in the majority of situations in which immunity is activated, it can also be harmful, damaging the body through autoimmune mechanisms or even, through its absence, creating space for infectious agents to act free. Our study of a control group for KIR genotype and haplotypes in Brazilian Caucasoids could be used in future analyse of diseases related to these genes.

Effects of neuraxial block and general anesthesia on tumor metastasis in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of different anesthesia methods on immune surveillance and tumor metastasis in tumor-bearing rats.</p><p><b>METHODS</b>Seventy-two Fischer 344 rats were randomly assigned into 3 equal groups and anesthetized for 1 h with ketamine (group K), propofol (group P), or neuraxial block (group B). All the rats were subjected to laparotomy followed by intravenous injection of MADB106 tumor cells, and 24 h after the injection, the number and activity of circulating CD3(+), CD4(+), CD8(+), and D4(+)/CD8(+) lymphocyte subsets and NK cellèCD161a(+)éwere assessed. Three weeks later, the lung metastases were counted.</p><p><b>RESULTS</b>Compared with those in group B, the numbers of CD3(+), CD4(+), CD8(+), and CD161a(+) lymphocytes and the activity of circulating NK cells were significantly reduced, and the lung metastases of MADB106 increased significantly in groups K and P (P<0.05 or 0.01 ). The activity of immune surveillance in group K was significantly lower than that in group P except for CD8(+) cells, and the tumor metastases in group K increased significantly in comparison with those in group P (P<0.05 or 0.01).</p><p><b>CONCLUSION</b>Neuraxial block provides protection of the activity of immune surveillance and reduces tumor metastases in tumor-bearing rats compared with general anesthesia.</p>

Incidencia y patrones de transmisión de rubeola en México / Incidence and transmission patterns of rubella in Mexico

OBJETIVO: Describir los cambios en los patrones de transmisión de rubeola en México. MATERIAL Y MÉTODOS: Se analizó la incidencia durante el periodo 1990 a 2005 y se calcularon la tendencia por regresión lineal simple y el corredor endémico por transformación logarítmica de la media geométrica de las tasas de incidencia mensual y recorridos superior e inferior por IC95 por ciento. RESULTADOS: La morbilidad mostró una tendencia estable de 1990 a 1998 y descendente de 1999 a 2005 (r=-0.88, r²=0.77), con disminución acumulada de 97.1 por ciento. Además, se observaron la atenuación de la variación estacional, la interrupción transitoria de transmisión en 13 estados y el aumento de la proporción de casos en personas de 15 a 44 años y menores de un año, después del inicio de la vacunación antes de los siete años y de la estrategia combinada de inmunización (niños y adultos), respectivamente, con reducción de la incidencia en ambos grupos. CONCLUSIONES: El reforzamiento de la vigilancia y la vacunación sistemática y suplementaria favorecerá la interrupción endémica y la propuesta de su eliminación continental para 2010.

OBJECTIVE: To describe changes in the transmission patterns of rubella in Mexico. MATERIAL AND METHODS: An analysis of rubella incidence during 1990-2005 was performed to estimate the morbidity trend through a simple linear regression model. Endemic mapping was carried out by logarithmic transformation of the geometric mean of monthly incidence rates and 95 percent CI to estimate high and low endemic ranges. RESULTS: A stable trend was observed in morbidity during 1990-1998 ,descending during 1999-2005 (r=-0.88, r²=0.77), with a 97.1 percent cumulative decrease. Attenuation during seasonal variation, temporary interruption of transmission in 13 states and increase in the proportion of cases in 15-44 year-olds as well as in children less than one year of age, have been observed respectively after starting vaccination of children less than seven years of age and the implementation of combined strategy (children and adults) for rubella immunization, with incidence decrease in both groups. CONCLUSION: Reinforcement of surveillance and routine-supplemental immunization activities would favor the interruption of endemic rubella and contribute to the continent-wide elimination proposal for 2010.

Virus respiratorio sincicial, aún un misterio / Respiratory syncytial virus, still a mystery

El Virus Respiratorio Sincicial (VRS) es hoy el virus respiratorio que más produce enfermedades respiratorias en niños, el que más origina hospitalizaciones y al que con más frecuencia se le atribuye una relación íntima con el asma. A pesar del mayor conocimiento, los esfuerzos para combatirlo han sido infructuosos. Hasta ahora, sabemos con certeza que cada año viene y al no existir una vacuna efectiva, no contar con drogas antivirales seguras, sólo nos queda prepararnos para lo peor.

Significance of neo-angiogenesis and immuno-surveillance cells in squamous cell carcinoma of the tongue

Neo-angiogenesis is an essential process in physiological and pathological conditions. However, it is a complex process. Several studies demonstrated that intra-tumoural microvessel number is a significant predictor of metastasis and clinical outcome in many tumours, including oral malignancies. The immuno-surveillance cells, mast cells and eosinophils are implicated in the biological behaviour of tumours. Nevertheless, their function in tissues is uncertain. Mast cells are involved in homeostatic regulation of blood vessels as well as host defence. In some malignancies, high mast cell density has been found to correlate with favourable prognosis. However, others reported unfavourable associations. Tumour associated tissue eosinophilia is a well-known phenomena. It has been associated with good and poor prognosis. However, the role of eosinophils in tumours remains controversial. Therefore, this study was designed to investigate the prognostic value of microvessel, mast cell and eosinophil densities in the context of clinico-pathological parameters and survival in squamous cell carcinoma of the tongue. Anti-CD105 and anti-tryptase monoclonal antibodies were utilized to highlight and count microvessels and mast cells respectively in 81 cases of tongue squamous cell carcinoma. Eosinophils were demonstrated using carbol chromotrope histochemical stain. The densities were counted per mm2 and correlated with patients' outcome and other clinico-pathological parameters using non-parametric tests and student's t-test. Clinically, the cases were divided into 4 main groups depending on survival time, lymph-node or distant metastasis. The 5 year survival was significantly lower in patients with a low mast cell density than those with a high density [p=0.006, Kruskal-Wallis test]. The survival group-A demonstrated significantly higher mast cell and microvessel numbers than group-D [p=0.007, student's t-test] respectively. Patients with well- differentiated squamous cell carcinoma had significantly higher numbers of mast cells when compared to patients with poorly differentiated squamous cell carcinoma [p < 0.05, student's t-test]. The lymph node involvement correlation between the survival group-A and survival group-D was also significant [p=0.001, Mann-Whitney U test]. Data from this study indicates that accumulating mast cells in tumours play a part in inhibiting tumour progression and is potentially angiogenic in tumours

Hepatitis C virus infection at Sharkia Governorate, Egypt: Seroprevalence and associated risk factors

A sample of 1422 individuals was included in the study, using multistage sampling technique. Exposures and demographic characteristics were obtained through a pre-designed questionnaire. Antibody to HCV was assessed using micro-particle enzyme immunoassay [MEIA] enzyme assay by IMX and the HCV RNA was tested by real-time PCR technique using ABI Prism 7700 system. The seroprevalence of antibodies to HCV was 23.4% and 27.4% in urban and rural areas, respectively, with an overall prevalence of 25.8%. This reflected prior HCV infection, but not necessarily a current liver disease. The prevalence was higher among males than females and increased sharply with age, from 4.8% in those <20 years old to 41.9% in the older ages [>/40 years]. Those who were not educated and farmers had a significantly high prevalence. The significant predictors of HCV infection were previous parenteral therapy for schistosomiasis [OR = 4.3, 95%, CI = 3.6-7.9], among those over 20 years of age [3.5, 2.18-5.8], blood transfusion [4.1, 2.4-6.9], invasive procedures [surgery and endoscopy] and the use of contaminated syringes and needles. Also, shaving at community barbers added a significance to the model

A Case of Kaposi's Sarcoma Associated with Pancreatic Cancer / 대한피부과학회지

The association of classic Kaposi's sarcoma with other neoplasm(primary or secondary) may serve as a clinical indicator for altered immunologic surveillance mechanisms. The association have been discussed for several decades. But the association of Kaposi's sarcoma with pancreatic cancer has not been reported. We report a case of Kaposi's sarcoma associated with pancreatic cancer in a 79-year-old man, who had tender papules and plaques on the left hand. The histopathologic findings showed typical features of Kaposi's sarcoma as a dermal tumor composed of vascular proliferations, vascular slits, spindle cells, extravasated erythrocytes and deposits of hemosiderin.

Bioseguridad / Biosafety

Encuestas recientes sobre la administración de inyecciones en servicios de vacunación realiazadas en cuatro de seis regiones de la OMS, indican que hasta 30 por ciento de las inyecciones vacunales, no son estériles; como cambiar la aguja de una jeringa cargada con varias dosis de vacuna o usar agujas y jeringas para varias inyecciones, se toleran bajo el pretexto de la escasez permanente deequipo para inyecciones. Los nuevos retos que ha emprendido el PAI de Bolivia a través de lo que ha denominado el PAI de Segunda Generación, obligan a que se ponga de relieve la necesidad de mantener la calidad y la eficacia del programa nacional, en virtud de la introducción de nuevas vacunas y la ampliación y mejoramiento de las estrategias de vacunación con las vacunas tradicionales. En este sentido se hace pertinenete desarrollar normas operativas para las prácticas adecuadas de bioseguridad relacionadas a la vacunación.

El sistema inmune: herramienta estratégica en la batalla contra el cáncer / The inmune system: a strategic weapon in the battle against cancer

Las células tumorales ven alterada la regulación de su ciclo celular y comienzan a proliferar en forma descontrolada debido a mutaciones en su material genético. Además de las alteraciones en la proliferación, se producen modificaciones genéticas que dan origen a cambios en la expresión de proteínas en la célula maligna, lo que se manifiesta en la sobreexpresión de algunos genes o en su activación en tejidos normales, en los que comúnmente no son expresados. Estos genes originan proteínas que pueden ser reconocidas como aberrantes por el sistema inmune, generando una respuesta antitumoral. Recientemente, estudios realizados en animales de experimentación y en pacientes han demostrado que la principal actividad antitumoral está dada por la respuesta inmune celular. En esta situación, son los linfocitos T los que juegan un papel preponderante, reconociendo, a través de su receptor, antígenos que han sido procesados y presentados en asociación con las moléculas del complejo principal de histocompatibilidad (MHC). La gran mayoría de los antígenos asociados a tumor (AAT) y reconocidos por linfocitos T CD8+ citotóxicos (CTL) son péptidos derivados de proteínas que se expresan en las céluolas tumorales y además se encuentran en el tejido normal que les dio origen. Así, en melanoma humano por ejemplo, existen antígenos inmunodominantes derivados de proteínas involucradas en la síntesis de melanina y expresados tanto en el tumor como en los melanocitos normales. Existen otros antígenos restringidos por MHC que son comunes a varios tipos de tumores. Estos derivan de proteínas embrionarias y normalmente no se expresan en tejidos somáticos. La identificación de varios AAT ha permitido desarrollo de modernas vacunas antitumorales, las que se encuentran en etapa de experimentación. Estas vacunas, basadas en los antígenos descritos, pueden ser de tipo peptídico o de ADN y vendrían a reemplazar las terapias inmúnológicas menos específicas, como el tratamiento con citoquinas o las terapias adoptivas. Investigaciones clínicas y preclínicas llevadas a cabo durante los últimos dos años indican que la forma de inmunizar resulta esencial para inducir una respuesta inmune efectiva y evitar la anergia o tolerancia. Aquí juegan un papel determinante las células dendríticas en su función de células presentadoras de antígenos profesionales y algunas citoquinas proinflamatorias