Hallazgos citológicos y factores de riesgo asociados a lesión cervical en mujeres pertenecientes a tres etnias indígenas del Estado Zulia / Cytological findings and risk factors associated to cervical lesions in indigenous women belonging to three etnias of Zulia State

El cáncer de cuello uterino (CaCu) representa un problema de salud pública y es considerado la segunda causa de muerte por cáncer en mujeres. Se han descrito factores de riesgo, los cuales están relacionados con hábitos, conductas y agentes infecciosos tales como el Virus de Inmunodeficiencia humana, herpes virus, Chlamydia trachomatis y Virus del Papiloma Humano (VPH). Con el fin de establecer los factores de riesgo y detectar lesiones preinvasivas de cérvix, se seleccionaron 101 mujeres de tres etnias indígenas, a las cuales se les realizó una encuesta clínico-epidemiológica, además del estudio citológico. Del total de pacientes estudiadas un 66,34% presentaron algún tipo de alteración, siendo las Yukpa las más afectadas, así mismo 21 (20,79%) presentaron neoplasia intraepitelial cervical y se encontraron agentes infecciosos en un 56,51% de las mujeres. En un 26,21% de las pacientes se encontraron células coilocíticas sugestivas de VPH. Al analizar los factores de riesgo se encontró que el inicio de relaciones sexuales antes de los 15 años, y el consumo de alcohol fueron los más relevantes. Es de importancia el diagnóstico oportuno en estas comunidades que se encuentran desasistidas y sin acceso a centros de salud, ya sea por condiciones de vida o por implicaciones culturales.

The cervical cancer represents a problem of public health and is considered the second reason of death by cancer in women. There have been described factors associated, related to the conduct, habits and infectious agents, such as Human Immunodeficiency Virus, herpes virus, Chlamydia trachomatis and Human Papilloma Virus (HPV). In order to establish risk factors and detect preinvasive cervical lesions, 101 samples of women from three indigenous ethnic groups of Zulia State were selected; to which a clinical-epidemiological survey was carried out to study the predisposing factors, in addition to the cytological study. Of the total of patients studied 33.66% were negative to the cytological study, while 66.34% had some type of alteration, observing that the Yukpa the most affected, 21 (20.79%) presented Cervical intraepithelial neoplasia and related infectious agents were found in 56.51% of the women. Coelocytic cells suggestive of HPV were found in 26.21% of all patients. When we analyzed the risk factors, we found that, the onset of sexual intercourse before age 15 as well as alcohol consumption were the most relevant. According to the findings, it is important the timely diagnosis in these communities, which are disassociated, and without access to health centers, whether due to living conditions or cultural implications.

Parasitosis intestinales y tisulares y su relación con la eosinofilia en una comunidad indígena Yukpa de la Sierra de Perijá, estado Zulia / Intestinal and tissue parasites and their relation with eosinophilia in a Yukpa Amerindian community from the Mountains of Perijá, state of Zulia

Para determinar la prevalencia de parasitosis intestinales y tisulares y su relación con la eosinofilia en una comunidad indígena Yukpa, se analizaron 91 muestras fecales y sanguíneas. A las muestras fecales se les practicó examen coproscópico y concentrado. Se realizó hematología completa para determinar cuenta blanca y porcentaje de eosinófilos, y en suero se efectuó un test de ELISA para la detección de anticuerpos anti- Toxocara canis y anti- Toxoplasma gondii. Se observó una elevada prevalencia de parasitosis intestinales (90,10%). Se apreció predominio de protozoarios sobre helmintos, siendo para los primeros el más prevalente Blastocystis sp. (51,64%) y para los segundos Ascaris lumbricoides (38,46%). La seroprevalencia de anticuerpos anti-Toxocara canis fue de 24,17% y anti-Toxoplasma gondii de 43.95%. No se observó diferencias estadísticamente significativas entre los grupos de edad y sexo en las diferentes parasitosis intestinales y tisulares. No se encontró asociación entre la seroprevalencia para Toxocara canis y la eosinofilia. Se apreció una asociación estadística significativa entre la presencia de eosinofilia y las helmintiasis. Estos resultados sugieren que existe una alta prevalencia de infecciones parasitarias en estas comunidades debido probablemente a sus costumbres y las condiciones sanitarias en las que habitan.

To determine the prevalence of intestinal and tissue parasites and their relationship with eosinophilia in Yukpa Amerindians, 91 fecal and blood samples were analyzed. The fecal samples underwent microscopic and concentrated examinations. Complete hematology was performed to determine white count and percentage of eosinophils; and ELISA tests were performed on the serum to detect anti-Toxocara canis and anti-Toxoplasma gondii antibodies. A high prevalence of intestinal parasites (90.10%) was observed. The predominance of protozoa over helminths was noted; for the first, the most prevalent were Blastocystis hominis (51.64%), and for the second, Ascaris lumbricoides (38.46%). Seroprevalence of anti-Toxocara canis antibodies was 24.17% and for anti-Toxoplasma gondi, 43.95%. No statistically significant differences were observed between age and sex groups for the different intestinal and tissue parasites. No association between seroprevalence for Toxocara canis and eosinophilia was found. A statistically significant association between the presence of eosinophilia and helminthiasis was observed. These results suggest that there is a high prevalence of parasitic infections in these communities due probably to their customs and the sanitary conditions in which they live.

Síndrome diarreico por rotavirus en niños menores de 5 años inmunizados y no de la ciudad de Maracaibo, estado Zulia, Venezuela / Diarrheic syndrome due to rotavirus in immunized and non-immunized children under 5, in the city of Maracaibo, state of Zulia, Venezuela

La diarrea aguda es la causa más común de morbi-mortalidad infantil, donde el Rotavirus es uno de los principales agentes involucrados en las diarreas severas en niños menores de 5 años. El presente estudio tiene como objetivo determinar la presencia de rotavirus en una población infantil con cuadros diarreicos, vacunados y no vacunados que acuden a observación pediátrica del Hospital de Niños y Hospital Universitario de Maracaibo, estado Zulia en el período de Abril 2011 hasta Abril 2012, para ello se recolectaron 100 muestras de heces y para el diagnóstico se utilizó la técnica de Aglutinación Directa en partículas de Látex. Resultaron positivos un 43,6% (24/55) de niños no vacunados y 33,3% (10/30) de niños vacunados afectando principalmente a los menores de 1 año con predominio del sexo masculino con un 65,9% sobre el sexo femenino con 40%, la diarrea por el agente viral estudiado representó casi la mitad de las hospitalizaciones por gastroenteritis, encontrándose una diferencia estadística significativa de p= 0.027 en el numero de evacuaciones del cuarto día, entre niños no vacunados (5) y vacunados (3). Los resultados de esta investigación muestran la circulación de rotavirus en niños vacunados y no vacunados, es por ello importante considerar que el presente reporte tiene como fin último alertar a la comunidad médica a considerar en todo niño con gastroenteritis la posibilidad de que se trate de un cuadro por RV.

Acute diarrhea is the most common cause of morbidity and mortality in infants, where rotavirus is one of the main agents involved in severe diarrhea for children under five years. The present study aims to determine the presence of rotavirus in a vaccinated and unvaccinated pediatric population with acute diarrhea that came to the Children’s Hospital and the University Hospital of Maracaibo, State of Zulia, for observation from April 2011 to April 2012. One-hundred stool samples were collected and direct agglutination of latex particles was used for diagnosis. 43.6% of the unvaccinated children were positive (24/55) as were 33.3% (10/30) of the vaccinated children. Principally, children under 1 year were affected, predominantly males with 65.9% and females with 40%. Diarrhea due to the viral agent under study accounted for nearly half the hospitalizations for gastroenteritis. A statistically significant difference of p = 0.027 was found between the number of evacuations on the fourth day in unvaccinated (5) and vaccinated (3) children. Results of this research show rotavirus circulating in vaccinated and unvaccinated children. Therefore, the purpose of this report is to alert the medical community to consider that every child with gastroenteritis could possibly have RV.

Frequency of adverse events and mortality in patients with pleural empyema in a public referral hospital in Mexico City.

SETTING: Adverse events (AEs) that occur during medical treatment are a public health problem. OBJECTIVE: 1) To measure the prevalence of AEs, 2) to characterize those that occur in patients diagnosed with empyema and 3) to analyze the mortality rate associated with the presence of empyema. DESIGN: Retrospective case series based on a review of files of patient diagnosed with empyema. RESULTS: A total of 347 files were assessed, reporting 96.6% of the total number of patients diagnosed with empyema in that period. There were 176 AEs reported for 150 of the patients. The frequency of at least one AE was 43%, with prolonged hospitalization being the most frequent condition. In these cases, 97% of the AEs were considered preventable. Intrahospital mortality was 4.8%, with age (HR for every 5 years 1.21, 95%CI 1.08-1.35, P < 0.001) and the presence of diabetes mellitus (HR 2.26, 95%CI 1.0-5.0, P = 0.04) being significant associated factors. CONCLUSION: There was a high frequency of AEs in patients with empyema, but most were considered preventable, especially the length of hospitalization, which could be reduced through timely surgery.

Meduloblastoma en pediatría: pronóstico y tratamiento en la actualidad / Medulloblastoma in pediatrics: current prognosis and treatment

En México, los tumores del sistema nervioso central representan el tercer lugar de todas las neoplasias malignas. El meduloblastoma constituye 20% de los tumores primarios del sistema nervioso central y 40% de los que se originan en el cerebelo; es el tumor maligno más frecuente en la niñez. Su origen se sitúa en la capa granular externa, normalmente migra del vermis hacia la superficie de los hemisferios cerebelosos y de ahí hacia las porciones profundas para poblar la capa granular interna de las folias. Estos tumores infiltran difusamente a través de las capas moleculares de la corteza cerebelosa por debajo de la pía, similar a lo que ocurre normalmente en las etapas embrionarias. Se diseminan por la circulación del líquido cefalorraquídeo con siembras a lo largo del espacio subaracnoideo y alrededor de la médula espinal para eventualmente salirse del sistema nervioso central y diseminarse a hueso, hígado, médula ósea y otros sitios menos frecuentes. Existen en la actualidad factores pronósticos bien definidos, así como el concepto de tratamiento multidisciplinario que ha condicionado mejores expectativas de supervivencia. El objetivo de esta revisión es actualizar el conocimiento de este tipo de tumores en nuestro país, así como los resultados terapéuticos.

In Mexico, Central Nervous System (CNS) tumors are the third most common childhood cancers. Medulloblastoma constitutes 20% of the primary CNS tumors and 40% of all cerebellar tumors, the single most common brain tumor among children. It originates over the external granular layer that normally migrates from the vermis to the surface of the cerebellum hemispheres and from there to the deep portions of the internal granular layer. These tumors infiltrate profusely the cerebellar cortex. The dissemination process can occur through the spinal fluid with seeding along the subarachnoidal space and around the spinal chord They eventually produce metastasis mainly to bone, liver, and bone marrow. There is a group of well identified prognostic factors that are relevant for each individual patient and that can be applied for multidisciplinary treatment purposes. The objective of the present review is to emphasize on new research findings and the overall survival that can be achieved with modern treatment programs.

[Medulloblastoma in pediatrics. Current prognosis and treatment]. / Meduloblastoma en pediatría. Pronóstico y tratamiento en la actualidad.

In Mexico, Central Nervous System (CNS) tumors are the third most common childhood cancers. Medulloblastoma constitutes 20% of the primary CNS tumors and 40% of all cerebellar tumors, the single most common brain tumor among children. It originates over the external granular layer that normally migrates from the vermis to the surface of the cerebellum hemispheres and from there to the deep portions of the internal granular layer. These tumors infiltrate profusely the cerebellar cortex. The dissemination process can occur through the spinal fluid with seeding along the subarachnoidal space and around the spinal chord They eventually produce metastasis mainly to bone, liver, and bone marrow. There is a group of well identified prognostic factors that are relevant for each individual patient and that can be applied for multidisciplinary treatment purposes. The objective of the present review is to emphasize on new research findings and the overall survival that can be achieved with modern treatment programs.

The evolution of RNA viruses: A population genetics view.

RNA viruses are excellent experimental models for studying evolution under the theoretical framework of population genetics. For a proper justification of this thesis we have introduced some properties of RNA viruses that are relevant for studying evolution. On the other hand, population genetics is a reductionistic theory of evolution. It does not consider or make simplistic assumptions on the transformation laws within and between genotypic and phenotypic spaces. However, such laws are minimized in the case of RNA viruses because the phenotypic space maps onto the genotypic space in a much more linear way than on higher DNA-based organisms. Under experimental conditions, we have tested the role of deleterious and beneficial mutations in the degree of adaptation of vesicular stomatitis virus (VSV), a nonsegmented virus of negative strand. We also have studied how effective population size, initial genetic variability in populations, and environmental heterogeneity shapes the impact of mutations in the evolution of vesicular stomatitis virus. Finally, in an integrative attempt, we discuss pros and cons of the quasispecies theory compared with classic population genetics models for haploid organisms to explain the evolution of RNA viruses.

[Orbital tumors in children. Transcranial surgical approach]. / Tumores orbitarios en niños. Su abordaje quirúrgico transcraneal.

From March 1980 to December 1995, at the Department of Neurosurgery of the Instituto Nacional de Pediatría (INP), 23 patients were treated for orbital tumors. In this communication, the authors report on the clinical presentation, age, radiological findings, visual-evoked potentials, type of surgery, histological diagnosis, and results. Two kinds of surgical techniques were employed: craniotomy with orbital roof removal (NAFZIGER) and fronto-orbitotomy. Eleven patients had optic nerve gliomas, 3 had fibrous osseous dysplasia, 2 meningiomas, neurofibromas, Langerhans cells histiocytosis, and 1 case of Anaplastic astrocytoma, Teratoma, primitive Neuroectodermal tumor, germinoma with areas of choriocarcinoma. The results were evaluated for the quality of life in regard to the Karnofsky scale, tumor recurrence and postoperative visual-evoked potentials. It is important to note the very variable histological kinds of lesions found in this series that can be approached surgically with cranio orbitotomy with good results.

Is the ancillary chemotherapy approach of any value in the treatment of infratentorial primitive neuroectodermal tumors with surgery and radiotherapy?

A retrospective historical analysis of patients under 18 years of age with the histopathological diagnosis of infratentorial primitive neuroectodermal tumor (PNET) is presented. The survey embraced two different groups of children. Group 1 was defined as those patients treated from 1972 to 1984 with surgical resection plus neuraxis radiotherapy alone. Group 2 was made up of children treated from 1990 to 1996 with the same approach but with the addition of adjuvant chemotherapy: cisplatin (day 1) and etoposide (days 1-3) every 3 weeks for 6 months. Group 1 embraced 42 children with an age range of 1-16 years (mean 6 years, SD 4.4 years). In group 2 there were 34 children, their ages ranging from 1 to 18 years (mean 7.2, SD 4.6 years). The prevalence of stages T2M0 and T3M0 was similar in both groups, but in group 1 there were 4 patients (9.5%) whose spinal fluid was positive for tumor cells (M1), while in group 2 there were 7 children (20.5%) with positive spinal fluid. There was an unequivocal initial response to treatment in 86% of these children in group 1 and in 79% in group 2. The event-free survival (EFS) was 30% at 252 months in group 1, while for group 2 the EFS was 67.6% at 63 months (P 0.002). Mortality from tumor activity was noted in 26 patients (70%) in group 1, while in group 2 mortality attributable to tumor progression was documented in 11 children (32%). We conclude that the use of adjuvant chemotherapy in these patients improves survival without any significant morbidity.

[Preventive program of birth defects: incidence of anencephaly in Maracaibo, Venezuela. 1993-1996 period]. / Programa preventivo de defectos del nacimiento: incidencia de anencefalia en Maracaibo, Venezuela. Período 1993-96.

Incidence of anencephaly in the State of Zulia, and specifically in the Eastern Coast of Lake Maracaibo, an oil exploitation area, has been declared high since the beginning of the 80's, coincident with the generalized use of ultrasound as a diagnostic tool for fetal evaluation. Through the Birth Defects Preventive Program, established at the Hospital Chiquinquirá in Maracaibo, we have developed a fourfold strategy for the study of birth defects: i) analysis of more than 32,332 ultrasound evaluations within the Ultrasound Service, between 1993 and 1996, ii) a case-control malformation registry beginning in 1995, iii) a study of malformed stillbirths at the Pathology Service, observed after 4232 deliveries within this hospital, and iv) a registry of over 638 mothers with high risk pregnancy for fetal defects detected at the prenatal clinic and carried out at the Perinatal Medical Genetics Service. As a reference population we study 345 medical histories obtained from the Medical Genetics and Prenatal Diagnostic Service at Hospital Coromoto, and oil companies related medical facility. This approach has led us to conclude that the incidence of anencephaly in the State of Zulia is 0.75/1000, significantly similar to that expected for most populations.

Genetic lesions associated with Muller's ratchet in an RNA virus.

The molecular basis of Muller's ratchet has been investigated using the important animal pathogen foot-and-mouth disease virus (FMDV). Clones from two FMDV populations were subjected to serial plaque transfers (repeated bottleneck events) on host BHK-21 cells. Relative fitness losses were documented in 11 out of 19 clones tested. Small fitness gains were observed in three clones. One viral clone attained an extremely low plating efficiency, suggesting that accumulation of deleterious mutations had driven the virus near extinction. Nucleotide sequence analysis revealed unique genetic lesions in multiply transferred clones that had never been seen in FMDVs isolated in nature or subjected to massive infections in cell culture. In particular, a frequent internal polyadenylate extension has identified a mutational hot spot on the FMDV genome. Furthermore, amino acid residue substitutions in internal capsid sites which are severely restricted during FMDV evolution, amounted to half of capsid replacements in the transferred clones. In addition, a striking dominance of non-synonymous replacements fixed upon large population infections of FMDV was not observed upon serial plaque transfers. The nucleotide sequence of the entire genome of a severely debilitated clone suggests that very few mutations may be sufficient to drive FMDV near extinction. The results provide an account of the molecular basis of Muller's ratchet for an RNA virus, and insight into the types of genetic variants which populate the mutant spectra of FMDV quasispecies.

Discovery and molecular characterization of a plasmid localized in Buchnera sp. bacterial endosymbiont of the aphid Rhopalosiphum padi.

We have identified and completely sequenced a novel plasmid isolated from the aphid Rhopalosiphum padi. Evidence which suggests that the plasmid occurs localized within the bacterial endosymbionts is presented. The plasmid contains the four genes that constitute the entire leucine operon. This fact makes it really unique since most plasmids are dispensable and lack genes that encode essential anabolic functions. Four more phloem-feeding aphid species also seem to contain homologous plasmids. Although further work is necessary, we hypothesize that this plasmid has appeared during the evolution of the symbiotic association between the aphid and the bacterial endosymbiont. The fact that this plasmid contains the entire leucine operon can be related to physiological evidence showing that the aphid host's diet of plant phloem is deficient in essential amino acids.

Epidemiology and long-term consequences of hepatitis delta virus infection in the Yucpa Indians of Venezuela.

To define better the epidemiology and clinical impact of hepatitis delta virus (HDV) infection among hepatitis B virus (HBV) carriers in less developed countries, the authors prospectively studied a cohort of 216 Yucpa Indian HBV carriers in Venezuela. HBV carriers were followed regularly between 1983 and 1988 by physical examination, laboratory testing for liver enzymes and HBV and HDV markers, and epidemiologic history. Among the cohort, 74 (34%) were initially positive for HDV infection, and 35 additional persons became infected during the study. Risk factors for new HDV infection included living in southern Yucpa villages; being young adults (15-19 years) or young children (1-9 years), and living in a household with a person with acute HDV infection. Persons with HDV infection were at high risk of developing chronic liver disease; 56% of HDV-infected persons had moderate-to-severe chronic liver disease at the end of the study compared with none of the HBV carriers without HDV infection. Mortality rates were 6.9% and 8.8% per year, respectively, among initially HDV-positive HBV carriers and those with new HDV infection, because of rapidly progressive chronic liver disease and fulminant hepatitis; mortality was significantly lower in HBV carriers without HDV infection and in non-HBV carriers. HDV superinfection is a devastating disease in HBV carriers in tropical South America. Prevention of HBV infection with hepatitis B vaccine is the best available tool to reduce the impact of this problem.

Glucose stabilization and coronary infarction with artificial pancreas in heart-lung preparation.

In the performance of heart-lung preparations, after 4-8 hours, it is an usual feature to have multiple microinfarctions, and, finally, heart failure and ventricular fibrillation. We have studied glucose, triglycerides and conjugated fructose consumption by the heart-lung preparation and found a very fast glucose depletion (30 to 90 minutes to glucose 0, starting with glucose 120 mg/dl). The depletion has been slower for triglycerides and even slower for conjugated fructose. Ventilation with pure oxygen has not modified itself the coronary deterioration, but if a Biostator has been used in order to maintain the glucose levels at 100-110 mg/dl., the isolated heart-lung does not deteriorate in 16-24 hours, nor show electrical signs of coronary impairment; after this time, the respirator is disconnected and the preparate discarded. The above mentioned experiments demonstrated the need of artificial control of glycemia in isolated organ experiments and suggest the convenience to use more widely the artificial pancreas (Biostator in our case) for better treatment no only in diabetic or pancreatic patients, but also in many circumstances in which the glucose utilization is impaired.

Delta virus infection and severe hepatitis. An epidemic in the Yucpa Indians of Venezuela.

Over a 3-year period, 149 Yucpa Indians in Venezuela developed hepatitis; 34 persons died and at least 22 developed chronic hepatitis. Children and young adults were primarily affected, especially males. Serologic testing showed that hepatitis B virus infection was highly endemic in this population, but also that 65% of patients had hepatitis B virus surface antigen (HBsAg) during or after illness. Most patients had evidence of delta-agent superinfection; 86% of HBsAg-positive patients had delta antibody, and delta antigen was found in specimens taken during autopsies on 7 of 9 patients. Serologic data suggested that most infections were due to delta superinfection of hepatitis B carriers, and that more than 60% of these infections progressed to chronic disease. Delta agent infection, and particularly delta superinfection of hepatitis B carriers, appears to be an ominous occurrence that may develop in populations among whom hepatitis B virus infection is endemic, and who have no other risk factor for delta infection.

Histologic studies of severe delta agent infection in Venezuelan Indians.

To supplement a detailed epidemiologic study of an outbreak of viral hepatitis in Venezuelan Indians in isolated valleys, apparently resulting from delta agent infection, 10 autopsy specimens were studied histologically and immunocytochemically, and five biopsy specimens were examined. The patients were children and young adults and predominantly males. A sequence of hepatitis from focal necrosis with conspicuous small-droplet steatosis, through massive necrosis, prolonged postnecrotic collapse to early cirrhosis with massive collapse was postulated. The histologic changes tentatively suggest a cytopathic effect of the delta agent without significant indication of lymphocytotoxicity, at least in the parenchyma. Delta agent was demonstrated in hepatocyte nuclei in moderate amounts in the focal-necrotic stage and in isolated cells in the massive-necrotic stage, but in large amounts during the transition to cirrhosis. Whether these patients, in whom neither HBcAg nor HBsAg were demonstrable in the liver, suffered exclusively from superinfection of hepatitis B virus carriers and/or coinfection of hepatitis B virus with the delta agent remains to be resolved. Delta infection may occur in isolated settings with no relation to Italian origin, drug addiction, or polytransfusion. The infection is far more widely spread than previously assumed.