High-Dimensional Feature Selection for Automatic Classification of Coronary Stenosis Using an Evolutionary Algorithm.

In this paper, a novel strategy to perform high-dimensional feature selection using an evolutionary algorithm for the automatic classification of coronary stenosis is introduced. The method involves a feature extraction stage to form a bank of 473 features considering different types such as intensity, texture and shape. The feature selection task is carried out on a high-dimensional feature bank, where the search space is denoted by O(2n) and n=473. The proposed evolutionary search strategy was compared in terms of the Jaccard coefficient and accuracy classification with different state-of-the-art methods. The highest feature selection rate, along with the best classification performance, was obtained with a subset of four features, representing a 99% discrimination rate. In the last stage, the feature subset was used as input to train a support vector machine using an independent testing set. The classification of coronary stenosis cases involves a binary classification type by considering positive and negative classes. The highest classification performance was obtained with the four-feature subset in terms of accuracy (0.86) and Jaccard coefficient (0.75) metrics. In addition, a second dataset containing 2788 instances was formed from a public image database, obtaining an accuracy of 0.89 and a Jaccard Coefficient of 0.80. Finally, based on the performance achieved with the four-feature subset, they can be suitable for use in a clinical decision support system.

Diagnostic Performance of 99mTc-iPSMA SPECT/CT in the Initial Staging of Patients with Unfavorable Intermediate-, High-, and Very High-Risk Prostate Cancer: A Comparative Analysis with 18F-PSMA-1007 PET/CT.

Prostate cancer is a leading cause of cancer death in men worldwide. Imaging plays a key role in disease detection and initial staging. Emerging data has shown the superiority of PSMA imaging with PET/CT over conventional imaging for primary diagnoses. Single photon emission computed tomography is more available worldwide, and the imaging agent is low in cost. The aim of this study is to compare the diagnostic accuracy of 99mTc-EDDA/HYNIC-iPSMA SPECT/CT to 18F-PSMA-1007 PET/CT in the primary diagnosis of prostate cancer and the impact on clinical staging. METHODS: In this prospective controlled study, 18 patients with histologically confirmed prostate cancer with unfavorable intermediate-, high-, and very high-risk characteristics were recruited to undergo 18F-PSMA-PET/CT and 99mTc-iPSMA SPECT/CT. The median age of the patients was 71 years old, and the median PSA level was 23.3 ng/mL. Lesions were divided into the prostate, seminal vesicles, lymph nodes, bone, and visceral metastases. Volumetric analysis was also performed between the two imaging modalities and correlated with PSA levels. RESULTS: A total of 257 lesions were detected on 18F-PSMA-PET/CT: prostate (n = 18), seminal vesicles (n = 12), locoregional lymph nodes (n = 62), non-locoregional (n = 67), bone (n = 90), and visceral (n = 8). Of these, 99mTc-iPSMA-SPECT/CT detected 229 lesions, while both reviewers detected 100% of the lesions in the prostate (18/18), seminal vesicles (12/12), and visceral (8/8); LN LR (56/62; 90%), NLR (57/67; 85%), and bone (78/90; 86%). There were no statistically significant differences between volumetric parameters (t = -0.02122; p = 0.491596). CONCLUSIONS: 99mTc-iPSMA SPECT/CT is useful in the primary diagnosis of prostate cancer. Despite it showing a slightly lower lesion detection rate compared to 18F-PSMA PET/CT, it exhibited no impact on clinical staging and, consequently, the initial treatment intention.

Radiomics Analyses to Predict Histopathology in Patients with Metastatic Testicular Germ Cell Tumors before Post-Chemotherapy Retroperitoneal Lymph Node Dissection.

BACKGROUND: The identification of histopathology in metastatic non-seminomatous testicular germ cell tumors (TGCT) before post-chemotherapy retroperitoneal lymph node dissection (PC-RPLND) holds significant potential to reduce treatment-related morbidity in young patients, addressing an important survivorship concern. AIM: To explore this possibility, we conducted a study investigating the role of computed tomography (CT) radiomics models that integrate clinical predictors, enabling personalized prediction of histopathology in metastatic non-seminomatous TGCT patients prior to PC-RPLND. In this retrospective study, we included a cohort of 122 patients. METHODS: Using dedicated radiomics software, we segmented the targets and extracted quantitative features from the CT images. Subsequently, we employed feature selection techniques and developed radiomics-based machine learning models to predict histological subtypes. To ensure the robustness of our procedure, we implemented a 5-fold cross-validation approach. When evaluating the models' performance, we measured metrics such as the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, precision, and F-score. RESULT: Our radiomics model based on the Support Vector Machine achieved an optimal average AUC of 0.945. CONCLUSIONS: The presented CT-based radiomics model can potentially serve as a non-invasive tool to predict histopathological outcomes, differentiating among fibrosis/necrosis, teratoma, and viable tumor in metastatic non-seminomatous TGCT before PC-RPLND. It has the potential to be considered a promising tool to mitigate the risk of over- or under-treatment in young patients, although multi-center validation is critical to confirm the clinical utility of the proposed radiomics workflow.

Time intervals to care and health service use experiences of uninsured cancer patients treated under public financing in Mexico City.

BACKGROUND: The present study assesses the time intervals from symptom discovery to treatment start and describes the health service use experiences of uninsured patients with cancer of the breast, cervix uteri, testicle, and prostate before their arrival to the cancer hospital. METHODS: This cross-sectional study included 1468 patients who were diagnosed between June 2016 and May 2017 and received treatment for the selected cancers in two of the largest public cancer hospitals in Mexico City, financed through Seguro Popular. Data was collected through a survey administered via face-to-face interviews with patients and a review of their medical files. RESULTS: The median time between detection (symptom discovery or first abnormal screening test) and treatment start was 6.6 months. For all types of cancer, the longest interval was the diagnostic interval -between the first use of healthcare services and the confirmation of cancer. Less than 20% cancer patients were diagnosed in the earliest stages that are associated with the best chances of long-term survival. The participants described a high use of private services for their first consultation, the use of several different types of health services and multiple consultations before arrival to the cancer centers, and 35% perceived being misdiagnosed by the first doctor they consulted. CONCLUSIONS: Most cancer patients treated in the two largest public institutions available for the uninsured faced long delays to get diagnosed and started treatment at advanced stages. Strengthening quality and access for effective early cancer diagnosis and treatment is key to improve patient outcomes in low and middle-income settings.

Association between life-course leisure-time physical activity and prostate cancer.

OBJECTIVE: To evaluate the association between life-course leisure-time physical activity (PA) and prostate cancer (PC) among males living in Mexico City. Materials and meth-ods. Information from 394 incident PC cases and 794 popula-tion controls matched by age (± 5 years), was analyzed. Using leisure-time PA information at different life stages, life-course PA patterns were constructed. The association between PA and PC was estimated using an unconditional logistic regres-sion model. RESULTS: Three life-course PA patterns were identified: low PA (71.0%), moderate PA (22.0%), and high PA (7.0%); this last pattern was characterized by higher levels and consistent PA practice. Compared with inactive males, those in the high PA pattern (OR: 0.50; 95%CI: 0.26-0.93) had significantly lower PC odds. CONCLUSION: Intense and regular PA could reduce the possibility of PC. These results are in accordance with PA World Health Organization rec-ommendations.

Association between life-course leisure-time physical activity and prostate cancer / Actividad física a lo largo de la vida y su asociación con cáncer de próstata

Abstract: Objective: To evaluate the association between life-course leisure-time physical activity (PA) and prostate cancer (PC) among males living in Mexico City. Materials and methods: Information from 394 incident PC cases and 794 population controls matched by age (± 5 years), was analyzed. Using leisure-time PA information at different life stages, life-course PA patterns were constructed. The association between PA and PC was estimated using an unconditional logistic regression model. Results: Three life-course PA patterns were identified: low PA (71.0%), moderate PA (22.0%), and high PA (7.0%); this last pattern was characterized by higher levels and consistent PA practice. Compared with inactive males, those in the high PA pattern (OR: 0.50; 95%CI: 0.26-0.93) had significantly lower PC odds. Conclusion: Intense and regular PA could reduce the possibility of PC. These results are in accordance with PA World Health Organization recommendations.

Resumen: Objetivo: Evaluar la asociación entre la actividad física (AF) en la vida y el cáncer de próstata (CP) en hombres. Material y métodos: Se analizó la AF de 394 casos incidentes de CP y 794 controles poblacionales pareados por edad (± 5 años). Se utilizó la información de AF en diferentes etapas para generar los patrones de AF a lo largo de la vida. La asociación entre AF y CP se estimó mediante regresión logística no condicionada. Resultados: Se identificaron tres patrones de AF: baja (71.0%), moderada (22.0%) y alta (7.0%); este último patrón se caracterizó por una AF consistentemente mayor a lo largo de la vida. Comparado con los hombres inactivos, aquéllos en el patrón de alta AF (RM= 0.50; IC95% = 0.26-0.93) presentaron menos posibilidades de tener CP. Conclusión: El papel protector de la AF parece estar en función de la intensidad y regularidad de su práctica y apoyan las recomendaciones de la OMS.

Cáncer de pene en México: 20 años de experiencia en un hospital académico de tercer nivel / Penile cancer in Mexico: Twenty years experience at a tertiary academic hospital

OBJETIVO: Revisar las características clínicas y el manejo del cáncer de pene (CP) en el Instituto Nacional de Cancerología (INCan) de la Ciudad de México en 20 años de experiencia. MATERIAL Y MÉTODOS: Revisamos de forma retrospectiva a 405 pacientes con diagnóstico de CP tratados en INCan entre enero de 1989 hasta diciembre de 2015. Se describieron la modalidad de presentación de los casos, los resultados de patología, tratamiento y la sobrevida. RESULTADOS: Las informaciones clínico-patológicas y los resultados oncológicos fueron completas en 375 pacientes (edad media 56,82). Al diagnóstico 140 casos (n.37,3%) fueron cN0, 71 casos (18,9%) cN1, 164 casos (43,37%) cN2, 33 casos (8%) cN3. El 14% tuvieron metástasis a distancia (pulmón, huesos). El tratamiento inicial incluyó falectomía parcial (n = 123; 33,6% y falectomía total (n = 126; 33,6%). De 138 (36,2%) pacientes de alto riesgo sometidos a disección de ganglios linfáticos inguinales bilaterales, solo el 8% (n.56) tenían ganglios linfáticos positivos. El análisis de supervivencia de Kaplan-Meier mostró una tasa de SCE (sobrevida cáncer específica) a 10 años del 70%. No hubo diferencias significativas en la supervivencia para el grupo de edad. La CSS a 5 años para pT1, pT2, pT3 y T4 fue del 96%, 88%, 58% y 0%, respectivamente. Se encontró diferencia en la supervivencia entre pT2 y pT3 (p 0,047). CONCLUSIÓN: Los hallazgos de nuestra casuística proporcionan información sobre la historia natural del cáncer de pene en México. La amputación quirúrgica del tumor primario sigue siendo el patrón uro-oncológico para el tratamiento definitivo del CP. No hubo diferencias en la supervivencia para el grupo de edad

OBJECTIVE: The aim of this study was to report clinical features and management of penile cancer (CP) at the National Cancer Institute (INCan) of Mexico City over 20 years. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 405 cases of primary penile cancer (PC) treated at our institution between 1989 until 2015. Diagnosis, treatment and oncological outcomes are reported. RESULTS: Clinicopathologic and demographic information was available for 375 patients (mean age, 56 ys). At diagnosis, 140 (37.3 %) patients were cN0, 71(18.9%) cN1, 164 (43.37%) cN2 and 33 (8%) cN3. 14% had metastatic disease (lung and bone). Initial treatment included partial penectomy (n = 123; 33.6%), and total penectomy (n = 126;33.6%). 138 (36.2%) patients with high risk disease underwent bilateral inguinal lymph node dissection. 8% (56) had positive lymph nodes. Kaplan-Meier survival analysis showed a 10-year CSS (cancer specific survival) rate of 70%. There was no significant difference in CSS when stratifying per age. Five-year CSS for pT1, pT2, pT3 and T4 was 96%, 88%, 58% y T4 0%, respectively. A difference in CSS was found between pT2 and pT3 (p = 0.047). CONCLUSION: The findings of our descriptive análisis provide information on natural history of penile cancer in Mexico. The surgical penile removal of the primary tumour remains standard of care. There was no difference in survival for age group

Relationship of Geographic Altitude with Foveal Avascular Zone Metrics and Vascular Density Values Assessed by OCT Angiography.

PURPOSE: To evaluate variations in vascular density (VD) and foveal avascular zone (FAZ) metrics in relation to geographic altitude in healthy subjects from 6 Latin American cities. DESIGN: Cross-sectional study. PARTICIPANTS: Healthy volunteers from 6 Latin American cities. METHODS: One hundred eighty-five volunteers were recruited over a 3-month period. The RTVue-XR Avanti system (Optovue, Inc, Fremont, CA) was used along with split-spectrum amplitude-decorrelation angiography (SSADA) software 7.1 to obtain OCT angiography (OCTA) images from fovea-centered 3 × 3-mm2 and 6 × 6-mm2 angioscans for both the superficial and deep capillary plexuses (SCP and DCP, respectively). FAZ measurements were performed in a full retina slab based on the full retina vasculature using OCT angiograms. Analyses of variance were performed for all variables, and P < 0.05 indicated statistical significance. MAIN OUTCOME MEASURES: Retinal SCP and DCP VD; FAZ area, perimeter, and parafoveal density at 300 µm (FD-300). RESULTS: Three hundred seventy eyes of 185 participants (71 males and 114 females; mean age, 39.09±15.06 years; age range, 20-80 years) were assessed. The mean VD in the SCP and DCP was 46.94% (±3.11%) and 52.48% (±3.14%), respectively, with 3 × 3-mm2 scans and 50.62% (±3.13%) and 52.87% (±5.5%), respectively, with 6 × 6-mm2 scans. Mean FAZ area, perimeter, and FD-300 were 0.31 (± 0.11 mm2), 2.18 (± 0.43 mm), and 51.44 (± 3.64%), respectively. Mean SCP VD values in 3 × 3-mm2 scans were significantly higher and lower in La Paz and Lima, respectively, compared to those in the other cities (P = 0.001). VD in the 6 × 6 mm2 SCP scans, the DCP (all scans), and FAZ metrics showed no significant differences. CONCLUSIONS: VD showed a direct relationship with geographic altitude in SCP 3 × 3-mm2 scans in this group of healthy Hispanic volunteers. These findings indicate that geographic altitude should be accounted for when performing retinal OCTA evaluation of VD values.

[Penile cancer in Mexico: Twenty years experience at a tertiary academic hospital.] / Cáncer de pene en México: 20 años de experiencia en un hospital académico de tercer nivel.

OBJECTIVE: The aim of this study was to report clinical features and management of penile cancer (CP) at the National Cancer Institute (INCan) of Mexico City over 20 years. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 405 cases of primary penile cancer (PC) treated at our institution between 1989 until 2015. Diagnosis, treatment and oncological outcomes are reported. RESULTS: Clinicopathologic and demographic information was available for 375 patients (mean age, 56 ys). At diagnosis, 140 (37.3 %) patients were cN0, 71(18.9%) cN1, 164 (43.37%) cN2 and 33 (8%) cN3. 14% had metastatic disease (lung and bone). Initial treatment included partial penectomy (n=123; 33.6%), and total penectomy (n=126;33.6%). 138 (36.2%) patients with high risk disease underwent bilateral inguinal lymph node dissection. 8% (56) had positive lymph nodes. Kaplan-Meier survival analysis showed a 10-year CSS (cancer specific survival) rate of 70%. There was no significant difference in CSS when stratifying per age. Five-year CSS for pT1, pT2, pT3 and T4 was 96%, 88%, 58% y T4 0%, respectively. A difference in CSS was found between pT2 and pT3 (p=0.047). CONCLUSION: The findings of our descriptive analysis provide information on natural history of penile cancer in Mexico. The surgical penile removal of the primary tumour remains standard of care. There was no difference in survival for age group.

OBJETIVO: Revisar las características clínicas y el manejo del cáncer de pene (CP) en el Instituto Nacional de Cancerología (INCan) de la Ciudad de México en 20 años de experiencia.MATERIAL Y MÉTODOS: Revisamos de forma retrospectiva a 405 pacientes con diagnóstico de CP tratados en INCan entre enero de 1989 hasta diciembre de 2015. Se describieron la modalidad de presentación de los casos, los resultados de patología, tratamiento y la sobrevida. RESULTADOS: Las informaciones clínico-patológicas y los resultados oncológicos fueron completas en 375 pacientes (edad media 56,82). Al diagnóstico 140 casos (n.37,3%) fueron cN0, 71 casos (18,9%) cN1, 164 casos (43,37%) cN2, 33 casos (8%) cN3. El 14% tuvieron metástasis a distancia (pulmón, huesos). El tratamiento inicial incluyó falectomía parcial (n=123; 33,6% y falectomía total (n=126; 33,6%). De 138 (36,2%) pacientes de alto riesgo sometidos a disección de ganglios linfáticos inguinales bilaterales, solo el 8% (n.56) tenían ganglios linfáticos positivos. El análisis de supervivencia de Kaplan-Meier mostró una tasa de SCE (sobrevida cáncer específica) a 10 años del 70%. No hubo diferencias significativas en la supervivencia para el grupo de edad. La CSS a 5 años para pT1, pT2, pT3 y T4 fue del 96%, 88%, 58% y 0%, respectivamente. Se encontró diferencia en la supervivencia entre pT2 y pT3 (p 0,047).CONCLUSIÓN: Los hallazgos de nuestra casuística proporcionan información sobre la historia natural del cáncer de pene en México. La amputación quirúrgica del tumor primario sigue siendo el patrón uro-oncológico para el tratamiento definitivo del CP. No hubo diferencias en la supervivencia para el grupo de edad.

Renal Cell Carcinoma in a Pregnant Woman With Horseshoe Kidney.

To our knowledge, this is the first reported case of renal cell carcinoma in kidney horseshoe diagnosed in the second trimester of pregnancy. We performed open radical nephrectomy when the pregnancy was completed. Kidney cancer is rare during pregnancy and the symptoms can be mimic urinary infection. The diagnosis and its management can be a challenge.

History of gonorrhea and prostate cancer in a population-based case-control study in Mexico.

UNLABELLED: We evaluated the association between a history of sexually transmitted diseases (STDs) and the risk for prostate cancer (PC) among Mexican males. METHODS: PC incident cases (n=402) that were identified at six public hospitals in Mexico City were matched by age (±5 years) with 805 population controls with no history of PC. By face-to-face interview, we obtained information about sexual history, previous STDs, sociodemographic characteristics, and familial history of PC. An unconditional logistic regression model was used to estimate the risk for PC. RESULTS: A total of 16.6% of men reported having had at least one previous STD, and the most frequently reported STD was gonorrhea (10.5%). After adjusting by PC familial history, the history of STD was associated with a two-fold greater risk of PC: odds ratio (OR)=2.67; 95% confidence interval (95% CI=1.91-3.73). When each STD was evaluated separately, only gonorrhea was associated with a significant increase in PC risk (OR=3.04; 95% CI=1.99-4.64). These associations were similar when we stratified by low-risk PC (Gleason <7) and high-risk PC (Gleason ≥7). CONCLUSION: These results confirm that STDs, and particularly gonorrhea, may play an etiological role in PC among Mexican males, which is consistent with a previous report from a multiethnic cohort.

Growing teratoma syndrome.

Growing teratoma syndrome (GTS) is a rare clinical entity, which presents with enlarging teratomas masses of the retroperitoneum or other locations, occurring during or after systemic chemotherapy for the treatment of nonseminomatous germ cell of the testis (NSGCT), with normalised tumour markers. Awareness of this syndrome is necessary in order to prevent unnecessary chemotherapy and allow optimal management. Prognosis is excellent after the excision of these tumors, but surgery has to be as complete as possible. Surgical resection of bulky GTS lesions is technically challenging; intraoperative complications may occur; that is, why the treatment must not be delayed. Our experience in the surgical management of these lesions is reviewed in the following work.

Morfometría macroscópica del ovario y cuerpo lúteo de yeguas criollas de Colombia / Macroscopic Morphometry of the Ovary and Corpus Luteum of Native Mares in Colombia / Morfometria macroscópica do ovário e corpo lúteo de éguas criollas da Colômbia

El objetivo del presente estudio era realizar una descripción de parámetros morfométricos del ovario y cuerpo lúteo (CL) de yeguas criollas de Colombia. Se utilizaron cincuenta ovarios provenientes de yeguas adultas. Todos los animales se encontraban clínicamente sanos. Los tejidos se obtuvieron después del sacrificio y se fijaron inmediatamente en formalina tamponada. Se pesó y se midió el diámetro mayor y el menor del ovario. Se realizó una incisión longitudinal con la finalidad de observar el parénquima del órgano. Se removió el CL y se registró su peso y diámetro. Los datos se analizaron a través de estadística descriptiva y el grado de asociación de las variables se calculó a través de un modelo de regresión simple. Se transformaron los datos con logaritmo en base natural cuando se requirió. El diámetro mayor del ovario varió desde 2 hasta 6,2 cm. El diámetro del CL varió desde 1,1 hasta 3,6 cm. Se encontró una relación lineal entre el peso y el diámetro del ovario (R² = 0,41; p < 0,01) y entre el peso y el diámetro del CL (R² = 0,48; p < 0,01). Aunque la relación entre el peso del ovario y el cuerpo lúteo es lineal, el coeficiente de determinación fue muy bajo. La yegua criolla colombiana tiene características similares en la morfología ovárica y luteal a las reportadas en la literatura para yeguas de otras razas livianas. Los valores aquí reportados podrían ser el punto de partida para establecer valores de referencia de utilidad clínica.

The purpose of this study was to describe the morphometric parameters of the ovary and corpus luteum (CL) of native mares in Colombia. Fifty ovaries from adult mares were used. All animals were clinically healthy. The tissues were collected after slaughter and immediately fixed in buffered formalin. The large and small diameters of the ovary were weighted and measured. A longitudinal incision was made in order to observe organ parenchyma. The CL was removed and its weight and diameter were recorded. Data were analyzed with descriptive statistics, and the degree of association between the variables was calculated through a simple regression model. When required, data were transformed with natural base logarithm. The large diameter of the ovary ranged from 2 to 6.2 cm. The diameter of the CL ranged from 1.1 to 3.6 cm. A linear relationship was found between the weight and diameter of the ovary (R² = 0.41; p < 0.01) and between the weight and diameter of the CL (R² = 0.48; p < 0.01). On the other hand, although the relationship between the weight of the ovary and corpus luteum is linear, the determination coefficient was very low. Luteal and ovarian morphology of native mares in Colombia has similar characteristics to those reported in literature for other light breed mares. The values reported herein could be the starting point to establish reference values for clinical utility.

O objetivo do presente estudo era realizar uma descrição de parâmetros morfométricos do ovário e corpo lúteo (CL) de éguas criollas da Colômbia. Utilizaram-se cinquenta ovários provenientes de éguas adultas. Todos os animais se encontravam clinicamente saudáveis. Os tecidos foram obtidos depois do sacrifício e se fixaram imediatamente em formalina tamponada. Foi pesado e medido o diâmetro maior e o menor do ovário. Realizou-se uma incisão longitudinal com a finalidade de observar o parênquima do órgão. Removeu-se o CL e se registrou seu peso e diâmetro. Os dados se analisaram com estatística descritiva, e o grau de associação das variáveis se calculou através de um modelo de regressão simples. Transformaram-se os dados com logaritmo em base natural quando se requerido. O diâmetro maior do ovário variou desde 2 até 6,2 cm. O diâmetro do CL variou desde 1,1 até 3,6 cm. Encontrouse uma relação linear entre o peso e o diâmetro do ovário (R² = 0,41; p < 0,01) e entre o peso e o diâmetro do CL (R² = 0,48; p < 0,01). Enquanto que, ainda sendo linear a relação entre o peso do ovário e o corpo lúteo, o coeficiente de determinação foi muito baixo. A égua criolla colombiana tem características similares na morfologia ovárica e lútea a as relatadas na literatura para éguas de outras raças leves. Os valores aqui reportados poderiam ser o ponto de partida para estabelecer valores de referencia de utilidade clínica.

Testicular cancer in androgen insensitivity syndrome in a Mexican population.

Male pseudohermaphroditism and androgen insensitivity syndrome cases have an increased risk of developing testicular cancer due to many factors such as mutations, hormonal disturbances involving gonadotropins and cryptorchidism. We describe the clinical features, diagnosis and treatment of two cases with partial androgen insensitivity syndrome and testicular cancer development, which were handled at the National Cancer Institute of Mexico.

Zonificación agroecológica mediante uso y aplicaciones de sistemas de información geográfica, para un ordenamiento territorial en la región andina del Municipio de Tiraque

Este trabajo se desarrollo en la región andina del municipio de Tiraque, cosiderada como área de acción del PDA- Tiraque, con la colaboración del Centro de Investigaciones y Servicios en Teledetección (CISTEL), y el proyecto de Desarroollo de área Tiraque (PDA-Tiraque). Se utilizó como principal herramienta Sistema de Información Geográfica (Arc View GIS Versión 3.2). Se adoptó la metodología de zonificación agroecológica de la FAO 1997 y la Guía metodológica para la Formulación de planes Municipales de Ordenación Territorial de Bolivia y el marco general de Ordenamiento Territorial 1997, tomando como base principal las necesidades y requerimiento de la misma, la conjugación de estas fueron adaptadas al medio geográfico de la región logrando asi una metodología propia para el Municipio de Tiraque. La zonificación agroecológica permite; delimitar zonas biofísicamente homogéneas, realizar una evaluación de tierras para identificar alternativas del uso potencial de las tierras de carácter normativo a través de recomendaciones de uso y manejo de cada unidad agroecológica identificada. La zonificación agroecológica para el Municipio de Tiraque constituye una base para una futura elaboración de Plan de Uso de los suelos PLUS que es parte de los objetivos del ordenamiento territorial.

Genotipificación de cepas de Histoplasma Capsulatum aisladas de pacientes con histoplasmosis asociada al SIDA, mediante el polimorfismo en la longitud de los fragmentos de restricción / Genotypic characterization of Histoplasma capsulatum isolates from AIDS associated-histoplasmosis-patients by using restriction fragment langth polymorphysms (RFLP)

Introducción: La histoplasmosis es una de las más importantes micosis asociada al síndrome de inmunodeficiencia adquirida (SIDA) en México. En este trabajo se efectuó la caracterización genotípica por el polimorfismo en la longitud de los fragmentos de restricción (RFLP) del DNA total de 31 cepas de Histoplasma capsulatum de pacientes con histoplasmosis asociada a SIDA, y su comparación con cepas de referencia de México, Panamá y Estados Unidos de America (EUA). Material y métodos: Las cepas fueron plenamente identificadas como H. capsulatum mediante su morfología colonial y microscópica, conversión de micelio a levadura y repoducción de exoantígenos probados por inmunodifusión con sueros específicos. El DNA total de las cepas fue obtenido a partir de micelio a levadura y producción de exoantígenos probados por inmunodifusión con sueros específicos. El DNA total de las cepas fue obtenido a partir de micelio macerado con nitrógeno líquido e incubado en presencia de proteinasa K y dodecilsulfato de sodio. El DNA fue diferido con la enzima HaeIII y los productos separados por electroforesis en agarosa y teñidos con bromuro de etidio. Utilizando el programa SPSS/PC+ se construyó un dendrograma a fin de establecer las relaciones polimórficas entre las cepas. Resultados y discusión: Las cepas formaron 10 grupos según sus perfiles de RFLP, obsevándose dos perfiles principales A y C con 33.3 y 29.1 por ciento de las cepas, respectivamente. Los perfiles restantes estuvieron representados por cepas únicas, a excepción del perfil J con dos cepas que mostraron un patrón similar al de la cepa Downs (clase 1, de EUA), No se encontró ningún perfil semejante a los de las cepas prevalentes en EUA o Panamá. El dendrograma mostró una relación de 85 por ciento entre las cepas de los perfiles de mayor prevalencia (A y C) asimismo del perfil J, además de las cepas Downs y FLs1 de los EUA. Los demás aislados con perfiles únicos se relacionaron en un 75 por ciento con las otras cepas