Seroprevalence of human leptospirosis in a rural community from Tandil, Argentina. Assessment of risk factors and spatial analysis.

Leptospirosis is a neglected zoonosis that is widely distributed in the world. Although it is endemic in Argentina, prevalence remains unknown. The aims of the study were: (i) to determine the prevalence of leptospirosis in humans from a rural community in Tandil Argentina, (ii) to identify infecting Leptospira spp. serogroups, (iii) to identify factors associated with the infection, (iv) to estimate the population attributable fraction (PAF) of the risk factors and (v) to determine the spatial patterns of disease presentation and related risk factors. Blood samples from 202 participants were collected. A survey was conducted to obtain clinical and epidemiological data. Serological testing was performed by the microscopic agglutination test (MAT). Univariate and multivariate methods were applied to evaluate associations. Spatial clusters were investigated for seroprevalence and risk factors. Antibodies were found in 32.2% of participants (95% CI: 25.8-39.1). The most prevalent serogroup was Hebdomadis followed by Sejroe; Icterohaemorrhagiae; Tarassovi and Canicola. Living at lower altitudes (OR: 13.04; 95% CI: 2.60-65.32); not having access to water supply network (OR: 2.95; 95% CI: 1.30-6.69); living close to flooded streets (OR: 2.94; 95% CI: 1.14-7.69) and practicing water sports (OR: 3.12; 95% CI: 1.12-8.33) were associated with seropositivity. Factors related with housing characteristics, services and infrastructure had the higher PAF (from 17% to 81%). A spatial cluster with higher rates of positivity and of the main risk factors was determined. This work contributes useful data for specific preventive measures that should be implemented for the control of the disease.

Estimation of methane emission from an urban wastewater treatment plant applying inverse Gaussian model.

The methane (CH4) emissions from urban sources are increasing, and they depend on the processes and technologies applied in each one. Thus, studying them individually to quantify their emissions and understand their behavior to design CH4 mitigation strategies is meaningful. Although many studies have been carried out in different cities worldwide, the complex methodologies and technologies applied are not readily available in developing countries. The main objective of this work is to apply a simple and inexpensive methodology to collect air samples in urban areas using syringes with a three-way stopcock. Considering the baseline concentration in different urban zones, the WWTP contribution to atmospheric CH4 concentration was assessed. Moreover, it was possible to estimate the CH4 emission rate from the source by applying the inverse Gaussian model. The atmospheric CH4 concentrations inside and around the WWTP varied from 2.04 to 32.78 ppm. Most of the highest concentrations were found inside the WWTP; however, high concentrations were found up to 500 m from its center. The values in the urban zones were between 2.06 and 3.52 ppm, consistently higher in the area with the highest population density. Finally, considering the WWTP as a single source and according to the operational and atmospheric conditions during the studied period, the mean CH4 emission rate from this source was 2.08E + 04 µg s-1. The proposed sampling methodology could be applied to estimate CH4 emission rates from fixed sources in areas with overlapping sources.

Seroprevalence of human leptospirosis in a rural community from Tandil, Argentina. Assessment of risk factors and spatial analysis / Seroprevalencia de leptospirosis humana en una comunidad rural del partido de Tandil (Argentina). Identificación de los factores de riesgo y del análisis espacial

Abstract Leptospirosis is a neglected zoonosis that is widely distributed in the world. Although it is endemic in Argentina, prevalence remains unknown. The aims of the study were: (i) to determine the prevalence of leptospirosis in humans from a rural community in Tandil Argentina, (ii) to identify infecting Leptospira spp. serogroups, (iii) to identify factors associated with the infection, (iv) to estimate the population attributable fraction (PAF) of the risk factors and (v) to determine the spatial patterns of disease presentation and related risk factors. Blood samples from 202 participants were collected. A survey was conducted to obtain clinical and epidemiological data. Serological testing was performed by the microscopic agglutination test (MAT). Univariate and multivariate methods were applied to evaluate associations. Spatial clusters were investigated for seroprevalence and risk factors. Antibodies were found in 32.2% of participants (95% CI: 25.8-39.1). The most prevalent serogroup was Hebdomadis followed by Sejroe; Icterohaemorrhagiae; Tarassovi and Canicola. Living at lower altitudes (OR: 13.04; 95% CI: 2.60-65.32); not having access to water supply network (OR: 2.95; 95% CI: 1.30-6.69); living close to flooded streets (OR: 2.94; 95% CI: 1.14-7.69) and practicing water sports (OR: 3.12; 95% CI: 1.12-8.33) were associated with seropositivity. Factors related with housing characteristics, services and infrastructure had the higher PAF (from 17% to 81%). A spatial cluster with higher rates of positivity and of the main risk factors was determined. This work contributes useful data for specific preventive measures that should be implemented for the control of the disease.

Resumen La leptospirosis es una enfermedad desatendida, ampliamente distribuida a nivel mundial. Aunque es endémica en Argentina, su prevalencia es desconocida. Los objetivos de este estudio fueron los siguientes: (i) determinar la prevalencia de leptospirosis humana en comunidades rurales del partido de Tandil (Argentina), (ii) identificar serogrupos infectantes de Leptospira spp., (iii) identificar factores de riesgo asociados, (iv) estimar la fracción atribuible poblacional (FAP) de los factores de riesgo y (v) determinar los patrones espaciales de la enfermedad y de los factores de riesgo. Se tomaron muestras de sangre a 202 personas, y se registró información clínica y epidemiológica. El diagnóstico se realizó por microaglutinación (MAT). Para evaluar asociaciones, se utilizaron métodos univariados y multivariados. Se estudiaron clusters espaciales de la seroprevalencia y de los factores de riesgo. El 32,2% de los participantes (IC 95%: 25,8-39,1) presentaron anticuerpos. Los serogrupos más prevalentes fueron Hebdomadis, Sejroe, Icterohaemorrhagiae, Tarassovi y Canicola. Vivir a menores altitudes (OR: 13,04; IC 95%: 2,60-65,32) y cerca de calles inundables (OR: 2,94; IC 95%: 1,14-7,69), la falta de acceso a agua de red (OR: 2,95; IC 95%: 1,30-6,69) y la práctica de deportes acuáticos (OR: 3,12; IC 95%: 1,12-8,33) estuvieron asociados con la seropositividad. Factores relacionados con las características de las viviendas, los servicios y la infraestructura tuvieron mayor proporción de FAP (17 al 81%). Se encontró un área de mayor riesgo de presentación de individuos seropositivos y de los principales factores de riesgo. Este trabajo provee información útil para generar medidas preventivas específicas que podrían ser aplicadas para controlar esta enfermedad.

[The patient with functional dyspepsia and his/her response to therapy]. / El paciente con dispepsia funcional y su respuesta terapéutica.

We studied during 12 months in the Centro de Especialidades Médicas "Esperanza Macarena" 997 patients with functional dyspepsia (324 males and 673 females) with a mean age of 37.4 and 42.6 years respectively. Patients with any organic disease, including diabetes, were excluded from the study. After completing the study we conclude that patients with functional dyspepsia constitute a large group of patients in gastroenterology clinics, that require multiple diagnostic tests, at great cost and scarce therapeutic successes. Only 36.5 percent of all patients had a good treatment response, most being under 40 years of age and with a relatively high cultural level. Therapeutic response depended on age, sex and social level. The best pharmacological results were obtained with cisapride (10 mg before meals).

Effectiveness of hemorrhoidal treatment by rubber band ligation and infrared photocoagulation.

OBJECTIVES: To demonstrate the effectiveness of the treatment of internal hemorrhoids with rubber band ligation (RBL) and infrared photocoagulation (IRC). PATIENTS AND METHODS: From march 1996 to december 1999, we prospectively studied 358 patients with a total of 817 hemorrhoid groups and a follow-up period of 36 months. Distribution according to gender and age was: 210 men with a mean age of 46 years and 148 women with a mean age 45.8 years. The mean number of hemorrhoids treated per patients was 2.3. All of them had complete a follow-up protocol at 15, 30, 60 and 180 days and at 12, 24 and 36 months. Rubber band ligation was performed with McGown ligator and suction pump, placing the band at the base of the hemorrhoid. For the infrared coagulation we used a Lumatec coagulation system, applying at least four shoots around each hemorrhoid, with an exposition time ranging between 1 and 1.5 seconds. Treatment was considered effective when patients became asymptomatic (relief of pain, bleeding or anal itching) and the obliteration of hemorrhoids after the treatment was confirmed by anal inspection and anoscopy. RESULTS: Two hundred ninety five of 358 patients were treated with RBL (82.4%), this treatment being effective in 98% of the patients after 180 days and very good after 36 months. There were 6/295 relapses at 36 months (2%). All minor and major complications were observed within the first 15 days of treatment: rectal tenesmus in 96/295 patients (32.5%), mild anal pain in 115/295 (38.9%), self-limited and mild bleeding after the detachment of the bands in 30/295 (10%), and febricula in one patient. Sixty three of 358 patients were treated with IRC (17.6%). In this group, relapses were observed in 6/63 patients (9.5%) at 36 months, all of them with grade III hemorrhoids that required additional treatment with RBL. All the complications (inherent to the technique) were observed within the first days: mild anal pain in 40/63 patients (63.4%) and mild bleeding in 1/63 (1.6%). The treatment with RBL or IRC depended on the number of hemorrhoids and the hemorrhoidal grade. No significant differences were found regarding the effectiveness between RBL and IRC for the treatment of grade I-II hemorrhoids, while RBL was more effective for grade III and IV hemorrhoids (p < 0.05). CONCLUSION: RBL and IRC should be considered as a good treatment for all grades of hemorrhoids, due to its effectiveness, its cost-benefit and its small short and long-term morbidity.

Relationship between degree of cellular differentiation in colorectal cancer and topographical distribution.

OBJECTIVES: To demonstrate the relationship between degree of cellular differentiation in colorectal cancer and topographical distribution in 215 patients diagnosed with colorectal cancer from 1997 to 2000. MATERIAL AND METHODS: 215 patients (129 men and 86 women) were studied prospectively with a mean age of 64 years (range: 23-84 years). In all patients we performed a full colonoscopy with several biopsies (in patients with colon stenosis we used barium enema), radiographic studies (CT, abdominal ultrasounds), and laboratory tests for serum tumour markers (CEA, Ca 19-9, alpha-fetoprotein). The topographic location of colorectal cancer was: rectum 35%, sigmoid colon 31%, descending colon 10%, transverse colon 6%, ascending colon 9%, caecum 5%, and we included anorectal cancer 4%. RESULTS: According to histological differentiation we found: A) well-differentiated tumours 101/215 (47%); B) moderately-differentiated tumours 98/215 (45.5%), and C) poorly-differentiated tumours 16/215 (7.5%). We found no significant association among histological differentiation, topographic location, stage according to the Astler-Coller classification, sex or age (p = ns). The prevalence of well-differentiated tumours in men was 49% and 43% in women; of moderately-differentiated cancers in men was 43%, and 49% in women; for poorly-differentiated tumours in men was 7.5%, and 7.2% in women. Regarding tumour location, 165 cancers were found in the left colon: 80 were well differentiated, 77 moderately differentiated and 8 poorly differentiated. In the transverse colon we found 12 tumours: 7 well differentiated, 3 moderately differentiated and 2 poorly differentiated. 30 cancers were localized in the right colon: 11 well differentiated, 15 moderately differentiated and 4 poorly differentiated. In the anorectum 8 tumours were found: 3 well differentiated, 3 moderately differentiated and 2 poorly differentiated. According to staging classification, well differentiated tumours (101/215) were more common in Dukes' C2 (20.7%) and B1 (32.6%), moderately differentiated cancers (98/215) were in B1 (28.5%) and C2 (20.4%), and poorly differentiated tumours (16) were more common in Dukes' C2 (25%), without differences among other stages (p = ns). CONCLUSIONS: According to our results we have found that histological differentiation of colorectal cancer has no association with topographic location, and it is independent of sex or age. We have not found any relationship either between histological differentiation and stage in the Astler-Coller classification, but well differentiated cancers were more common at any location, age or sex.

[The assessment of colonic polyps found via colonoscopy]. / Valoración de los pólipos colónicos hallados mediante colonoscopia.

AIM: To evaluate the histopathological characteristics of colonic polyps, found during colonoscopy examination and endoscopic polypectomy, and their relation to age, tumor location, sex, histological type and degree of epithelial dysplasia. MATERIAL AND METHODS: Between 1996 and 1997, 2,465 total colonoscopies were performed at the Gastroenterology Department of the Virgin Macarena University Hospital in Seville. Different size polyps were found in 318 patients who had been referred because of several symptoms/by several centers. The mean age was 59.2 years in men and 61.5 years in women. RESULTS: 446 polyps were removed by endoscopic polypectomy, 32 (7.2%) were hyperplastic polyps, 402 were adenomas (90.2%) and 12 (2.6%) were adenomas with adenocarcinoma. Seventy-five percent of adenomas were located in the left colon and rectum and 25% in right colon. Hyperplastic polyps were found in left colon. Of the polyps removed, 55.1% were smaller than 1 cm, 26.5% were between 1 and 2 cm and 18.4% were between 2 and 7 cm. Histopathologic study of adenomas revealed that 17% were villous adenoma, 80% were tubular adenomas and 3% were tubulovillous adenomas. Adenocarcinomas were found in 12 (2.8%) adenomas. Of the adenomatous polyps, 87.4% had low-grade dysplasia and 12.6% high-grade dysplasia. Statistical analysis showed a strong correlation between size of adenoma and degree of dysplasia (p < 0.05). Similar significant relation was found between histological type and size (p < 0.05) but there were no statistically significant differences between location, sex or age, and degree of dysplasia (p < 0.05). CONCLUSIONS: Size of colonic polyps is related to epithelial dysplasia and histological type (p < 0.05). No correlation was found between location, sex or age and degree of dysplasia.

Adenocarcinoma pulmonar diagnosticado por la presencia de metástasis duodenales y yeyunales / Lung adenocarcinoma caused by duodenal and jejunal metastases

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Eficacia del tratamiento hemorroidal mediante la ligadura con bandas elásticas y la fotocoagulación infrarroja / Effectiveness of he morrhoidal treatment by rubber band ligation and infrared photocoagulation

Objetivos: demostrar la eficacia del tratamiento hemorroidal mediante ligadura con bandas elásticas (LBE) y coagulación con rayos infrarrojos (CRI). Pacientes y métodos: desde marzo de 1996 hasta diciembre de 1999, han sido tratados 358 pacientes con un total de 817 paquetes hemorroidales y seguidos durante 36 meses. La distribución según sexo y edad fue la siguiente: 210 hombres con una edad media de 46 años y 148 mujeres con una edad media de 45,8 años. La media de hemorroides por pacientes fue de 2,3.Todos habían cumplido un protocolo de seguimiento a los 15, 30, 60 y 180 días, 12, 24 y 36 meses. La ligadura con bandas elásticas se realizó con un portabandas tipo McGown® mediante aspiración por vacío y disparo de la banda en la base de la hemorroide. La coagulación infrarroja se realizó con un coagulador tipo Lumatec®, con un tiempo de exposición de 1 a 1,5 seg por punto de aplicación alrededor la hemorroide y un máximo de 4 puntos de coagulación por cada hemorroide. El tratamiento fue considerado eficaz si el paciente estaba asintomático (ausencia de sangrado, dolor o prurito anal) y confirmada la obliteración de las hemorroides tratadas por inspección anal y anoscopia. Resultados: con bandas elásticas (LBE) se trataron un total de 295/358 pacientes (82,4 por ciento), siendo eficaz en el 98 por ciento de los pacientes a los 180 días y muy bueno a los 36 meses. Se observaron recidivas en 6/295 (2 por ciento) de los pacientes a los 36 meses. Todas las complicaciones menores y mayores se presentaron dentro de los primeros 15 días postratamiento; tenesmo rectal en 96/295 pacientes (32,5 por ciento), dolor anal leve en 115/295 (38,9 por ciento), sangrado escaso y autolimitado tras desprendimiento de bandas en 30/295 pacientes (10 por ciento) y febrícula en un paciente. Con coagulación infrarroja (CRI) se trataron 63/358 (17,6 por ciento) pacientes. En este grupo se observaron recidivas en 6/63 pacientes (9,5 por ciento) a los 36 meses, todas en portadores de hemorroides grado III, que se resolvieron mediante la colocación de bandas elásticas. La totalidad de las complicaciones (inherentes a la técnica) se presentaron en los primeros días, y consistieron en: dolor anal leve en 40/63 pacientes (63,4 por ciento), sangrado leve en 1/63 pacientes (1,6 por ciento).El tratamiento con LBE o CRI dependió del número de hemorroides y del grado hemorroidal. No se observaron diferencias en la eficacia entre la LBE y la CRI en el tratamiento de las hemorroides grado I-II, aunque la LBE mostró una eficacia superior en las hemorroides grado III y IV (p<0,05).Conclusión: la LBE y la CRI se deben considerar como un buen método terapéutico a emplear en cualquier grado hemorroidal, dada su eficacia, coste/beneficio y su escasa morbilidad a corto y largo plazo (AU)

Relationship between degree of cellular differentation in colorectal cancer and topographical distribution / Relationship between degree of cellular differentiation in colorectal cancer and topographical distribution

Objetivos: intentar establecer la relación existente entre el grado de diferenciación celular del cáncer de colon y su distribución topográfica, en 215 pacientes diagnosticados de cáncer colorrectal entre los años 1997 y 2000.Material y métodos: se estudiaron de forma prospectiva 215 pacientes (129 hombres y 86 mujeres) de edades comprendidas entre 23 y 84 años, con edad media de 64 años. En todos se realizó colonoscopia completa con varias tomas de biopsia. En los casos de estenosis tumoral con imposibilidad para sobrepasar la lesión se realizó enema opaco. Los estudios de extensión incluyeron TAC y ecografía abdominal, hemograma, perfil bioquímico completo y marcadores tumorales (CEA, Ca 19-9 y alfafetoproteina). La distribución topográfica de los cánceres colorrectales fue la siguiente: recto 78 (35 por ciento), sigma 66 (31 por ciento), descendente 21 (10 por ciento), transverso 12 (6 por ciento), ascendente 19 (9 por ciento), ciego 11 (5 por ciento), y anorrectal 8 (4 por ciento).Resultados: siendo el objetivo de nuestro estudio el establecer la relación entre el asentamiento tumoral en el colon y su grado de diferenciación celular encontramos: a) bien diferenciados 101/215 (47 por ciento); b) moderadamente diferenciados 98/215 (45,5 por ciento); y c) pobremente diferenciados 16/215 (7,5 por ciento). El cáncer bien diferenciado lo encontramos en el 49 por ciento de los hombres y en el 43 por ciento de las mujeres, el moderadamente diferenciado fue del 43 por ciento entre los hombres y del 49 por ciento entre las mujeres, el pobremente diferenciado fue del 7,5 por ciento entre los hombres y del 7,2 por ciento entre las mujeres. Según su distribución: en el colon izquierdo , 80 adenocarcinomas eran bien diferenciados, 77 moderadamente diferenciados y 8 pobremente diferenciados; en el colon transverso ; 7 adenocarcinomas eran bien diferenciados, 3 moderadamente diferenciados y 2 pobremente diferenciados, en el colon derecho 11 adenocarcinomas eran bien diferenciados, 15 moderadamente diferenciados y 4 pobremente diferenciados. De los 8 cánceres recto-anales , 3 eran bien diferenciados, 3 moderadamente diferenciados y 2 pobremente diferenciados, habiendo observado que dicho grado de diferenciación no tiene un significado estadístico de relación con la distribución topográfica del tumor. Según la clasificación por estadios, los bien diferenciados (101/215) fueron más frecuentes en los estadios B1 (32,6 por ciento) y C2 (20,7 por ciento); los moderadamente diferenciados (98/215) lo fueron en los estadios B1 (28,5 por ciento) y C2 (20,4 por ciento); el 25 por ciento de los estadios C2 fueron tumores pobremente diferenciados . No apreciamos diferencias estadísticamente significativas en la distribución de los grados de diferenciación por estadios (p=ns).Conclusiones: según nuestros resultados, no hemos observado que el grado de diferenciación celular del cáncer colorrectal se relacione con su localización inicial en el colon y es, igualmente, independiente del sexo y de la edad. En cuanto a su posible relación con la clasificación por estadios de Dukes y Astler-Coller tampoco hemos podido demostrarla (AU)