DICER1-associated central nervous system sarcoma: A comprehensive clinical and genomic characterization of case series of young adult patients.

Background: DICER1 alterations are associated with intracranial tumors in the pediatric population, including pineoblastoma, pituitary blastoma, and the recently described "primary DICER1-associated CNS sarcoma" (DCS). DCS is an extremely aggressive tumor with a distinct methylation signature and a high frequency of co-occurring mutations. However, little is known about its treatment approach and the genomic changes occurring after exposure to chemoradiotherapy. Methods: We collected clinical, histological, and molecular data from eight young adults with DCS. Genomic analysis was performed by Next-generation Sequencing (NGS). Subsequently, an additional germline variants analysis was completed. In addition, an NGS analysis on post-progression tumor tissue or liquid biopsy was performed when available. Multiple clinicopathological characteristics, treatment variables, and survival outcomes were assessed. Results: Median age was 20 years. Most lesions were supratentorial. Histology was classified as fusiform cell sarcomas (50%), undifferentiated (unclassified) sarcoma (37.5%), and chondrosarcoma (12.5%). Germline pathogenic DICER1 variants were present in two patients, 75% of cases had more than one somatic alteration in DICER1, and the most frequent commutation was TP53. Seven patients were treated with surgery, Ifosfamide, Cisplatin, and Etoposide (ICE) chemotherapy and radiotherapy. The objective response was 75%, and the median time to progression (TTP) was 14.5 months. At progression, the most common mutations were in KRAS and NF1. Overall survival was 30.8 months. Conclusions: DCS is an aggressive tumor with limited therapeutic options that requires a comprehensive diagnostic approach, including molecular characterization. Most cases had mutations in TP53, NF1, and PTEN, and most alterations at progression were related to MAPK, RAS and PI3K signaling pathways.

Applicability of DRIS in bananas based on the accuracy of nutritional diagnoses for nitrogen and potassium.

DRIS (Diagnosis Recommendation Integrated System) is a tool used in the interpretation of leaf analyses that values the balance of nutrients, an important fact for a better assessment of the nutritional status of banana plants. Its usefulness depends on the ability to identify the nutrients that limit productivity in order to correct possible nutritional imbalances, but there is a lack of research in all crops, including bananas, to assess the accuracy of these diagnoses, which have a worrying global implication. To this end, this study evaluates DRIS norms for banana cultivation in Ecuador and the use of accuracy measurements for nutritional diagnosis, verifying the capacity of DRIS to detect true nutritional status based on plant response. The database created here contains 233 results referring to productivity and leaf contents of N, P, K, Ca, Mg, S, Cl, Fe, Mn, Cu, B, and Zn for banana trees in 2018, 2019, and 2020. Then, a field experiment evaluated doses of nitrogen and potassium and the accuracy of DRIS norms for N and K. The results show that the DRIS of banana produced in Ecuador depends on the nutrient being variable according to the crop nutritional status. The DRIS norms for diagnosis of N and K result in an acceptable accuracy to identify only deficiencies and toxicities, respectively, indicating the need for adjustments in these standards for later use in the field. Thus, there is a need for more research aiming to adopt calibrated DRIS diagnostic norms to assess the nutritional status of bananas in Ecuador.

Identification of Toxoplasma gondii adhesins through a machine learning approach.

Toxoplasma gondii, as other apicomplexa, employs adhesins transmembrane proteins for binding and invasion to host cells. Search and characterization of adhesins is pivotal in understanding Apicomplexa invasion mechanisms and targeting new druggable candidates. This work developed a machine learning software called ApiPredictor UniQE V2.0, based on two approaches: support vector machines and multilayer perceptron, to predict adhesins proteins from amino acid sequences. By using ApiPredictor UniQE V2.0, five SAG-Related Sequences (SRSs) were identified within the Toxoplasma gondii proteome. One of those candidates, TgSRS12B, was cloned in plasmid pEXP5-CT/TOPO and expressed in E. coli BL21 DE3. The resulting recombinant protein was purified via affinity chromatography. Co-precipitation assays in CaCo and Muller cells showed interactions between TgSRS12B-His-tagged and the membrane fractions from both human cell lines. In conclusion, we demonstrated that ApiPredictor UniQE V2.0, a bioinformatic free software, was able to identify TgSRS12B as a new adhesin protein.

Hypophosphatemic Rickets in Colombia: A Prevalence-Estimation Model in Rare Diseases. 2018.

Background: Hypophosphatemic rickets is a rare, genetic syndrome with multisystem involvement. It causes skeletal abnormalities, painful enthesopathies, increased risk of fracture, and short stature; leading to a substantial burden of disease, disability, and worsening of quality of life. To improve health conditions of people living with this disease, it is essential to know its prevalence which is currently unknown in Colombia. This study aimed to estimate the prevalence of hypophosphatemic rickets in Colombia by using a mathematical model and national statistic records. Methods: We executed a model to estimate probabilities of transitions between health, disease, and death states (Markov chains). The model was fed with international prevalences taken from original studies (systematic review) and administrative records' data from SISPRO (a national health information system) using the International Classification of Diseases (ICD-10) E833 code, vital statistics, and census data. World Health Organization's (WHO) DISMOD II software was used to develop the model. Findings: The estimated overall prevalence of hypophosphatemic rickets in Colombia in 2018 was 2·03 cases per 100 000 people (981 affected people), with a sensitive range of 1·97 to 2·09. The estimated prevalence by sex was 2·61 (645 people) and 1·43 (336 people) cases per 100 000 women and men, respectively. Interpretation: Our overall estimated prevalence shows consistency with original international data. This is the first prevalence estimation of hypophosphatemic rickets in Colombia and will be relevant to support public health decisions for rare diseases and to provide a pre-test probability framework in clinical practice. DISMOD II and the model are useful tools to estimate the prevalence of rare and orphan diseases, when probabilistic studies cannot be carried out. There are limited bibliographic resources worldwide reporting prevalence values supported by original studies. Our study can be used as a cost-effective methodology reference in this regard, especially for Latin America. Funding: Ultragenyx Pharmaceutical, as a donation.

Current status of prevalence and risk factors associated with liver fluke Fasciola hepatica in cattle raised in different altitudinal regions of Colombia.

Fasciola hepatica is a trematode parasite with a worldwide distribution that affects mammals, including humans, and is considered a major food safety and public health problem. A research was conducted in three hundred eighty-five livestock farms located in different altitudinal regions of Colombia between February 2017 and March 2018 with the aim to determine the coprological prevalence, seroprevalence (SP) and risk factors associated with liver fluke F. hepatica. A total of 5620 fecal sample were collected from cattle and processed using sedimentation technique. Additionally, 597 blood samples were collected and processed by an ELISA test. The coprological prevalence of F. hepatica in animals and herds was 6.4% and 38.4%, respectively. Regarding the prevalence by municipalities, there was statistical association (P < .05), indicating that the prevalence was higher in those municipalities above 2000 masl (meters above sea level). Regarding risk factors, cattle raised in municipalities at 2000 to 3000 masl showed about 4 (OR = 3.96 [CI95% 3.1-5]; P < .05) times higher probability for infection than those raised at lower altitude. Cattle from 2 to 3 year of age, showed almost 4 times (OR = 3.7[CI95% 2.5-5.4]; P < .05), increased infection risk. Females and dairy breeds showed almost 2 (OR = 1.9 [CI95% 1.3-2.6]; P < .05) and 10 times (OR = 10 [CI95% 7.8-12.8]; P < .05), respectively, increased infection risk. The presence of antibodies anti- F. hepatica (SP = 37.8%; [CI95% 35.8-39.7]; P < .05) in cattle of the region under study is confirmed, which suggests an endemic behavior of this parasitosis. The present study provides current information on the prevalence of F. hepatica in different altitudinal regions of Colombia, and these findings could be useful for designing new holistic control measures for the liver fluke F. hepatica infection.

Biological ammonium and sulfide oxidation in a nitrifying sequencing batch reactor: Kinetic and microbial population dynamics assessments.

A kinetic study was carried out in a sequencing batch reactor (SBR) (125 mg NH4+-N/L) inoculated with a physiologically stable nitrifying sludge not previously acclimated to sulfur compounds and fed at different initial sulfide concentrations (2.5-20.0 mg HS--S/L). Up to 10.0 mg HS--S/L, the nitrifying process kept stable and complete, reaching an ammonium consumption efficiency (ENH4+) of 100% and a nitrate yield (YNO3-) of 0.95 ± 0.03 mg NO3--N/mg NH4+-N consumed. At 15.0 and 20.0 mg HS--S/L, after an initial alteration in the nitrite oxidizing process, the YNO2- was decreasing throughout the cycles and the YNO3- increasing, obtaining in the last cycle at 20.0 mg HS--S/L, an ENH4+ of 100%, a YNO2- of zero, and a YNO3- of 0.80 mg NO3--N/mg NH4+-N consumed. At the end of the period at 20.0 mg HS--S/L, the specific rates of ammonium consumption and nitrate formation were 15 and 55% lower than their respective values in the control period without sulfide addition, showing that the sludge had a better metabolic adaptation for ammonium oxidizing activity than for nitrite oxidizing activity. The sludge acquired a higher sulfide oxidation capacity along the cycles. Bacterial population dynamics assessment indicated that the ammonium oxidizing bacteria (AOB) community was more diverse and stable than the nitrite oxidizing bacteria (NOB) community. The use of consortia with a previously stabilized nitrifying activity in SBR may constitute an alternative for eliminating simultaneously ammonium by nitrification and sulfide by sulfide oxidation and be implemented for the treatment of wastewater with ammonium and sulfide.

Prevalence and molecular epidemiology of bovine leukemia virus in Colombian cattle.

Bovine leukemia virus (BLV) is one of the five agents considered most significant for cattle. It is important to determine the prevalence and molecular epidemiology of BLV throughout the country in order to gain a more thorough understanding of the current situation of BLV and to reveal the possibility of masked genotypes that the primers used by OIE are unable to identify. Blood samples were collected at random from 289 cows distributed in 75 farms across the country. PCR amplification of env, gag and tax gene segments was performed. The obtained amplicons were sequenced and then subjected to phylogenetic analyses. A total of 62% of the cows present at 92% of the farms were BLV-positive for gag fragment. Genotype 1 was exclusively detected by env gene segment when analyzed using previously reported primers. However, tax gene analysis revealed circulation of genotype 6 variants, which were also detected based on env gene analysis with newly designed primers. These results indicate that current genotyping approaches based on partial env sequencing may bias BLV genetic variability approaches and underestimate the diversity of the detected BLV genotypes. This report is one of the first molecular and epidemiological studies of BLV conducted in Colombia, which contributes to the global epidemiology of the virus; it also highlights the substantial impact of BLV on the country's livestock and thus is a useful resource for farmers and government entities.

La infiltración linfocitaria (tils) como factor pronóstico en pacientes con cáncer de mama Triple Negativo que realizan quimioterapia neoadyuvante / Intratumoral lymphocyte infiltration (tils) as prognostic factor in patients with Triple Negative breast cancer who underwent neoadjuvant chemotherapies

Introducción Los cánceres de mama Triple Negativo representan entre el 12 y el 17% de todos los carcinomas mamarios. Son un grupo heterogéneo con diferentes subgrupos. La reacción inflamatoria que produce el huésped como respuesta a la enfermedad puede cuantificarse a través de la infiltración linfocitaria intratumoral (tils). Objetivos Evaluar la infiltración linfocitaria intratumoral (tils) como factor pronóstico independiente en las core biopsias de las pacientes con cáncer de mama Triple Negativo que fueron sometidas a quimioterapias neoadyuvantes. Relacionarla con la respuesta patológica obtenida luego de la cirugía. Material y método Se seleccionaron retrospectivamente pacientes con carcinoma de mama Triple Negativo que realizaron quimioterapia neoadyuvante en la Unidadde Mastología de la Clínica Breast y en el Hospital Italiano de la Ciudad de La Plata entre los años 2014 y 2017. Se obtuvo una muestra de 36 pacientes. Resultados Sobre un total de 36 pacientes, 24 mostraron tils estromales menores al 50% y 12 mayores o iguales al 50%. El 16,7% de los tumores con tils menores al 50% y la mitad de los tumores con tils mayores o iguales al 50% presentaron una Respuesta Patológica Completa (rpc) post tratamiento quimioterápico neoadyuvante. En relación con los tils intratumorales, 6 tumores de 32 con tils menores al 50% (18,8%) y 4 de 4 (100%) con tils > o iguales al 50% presentaron una Respuesta Patológica Completa (rpc) post tratamiento quimioterápico neoadyuvante. Conclusiones En nuestra serie de casos, observamos que existe relación entre el porcentaje de tils y la respuesta patológica obtenida luego de la realización del tratamiento con quimioterapia neoadyuvante, siendo un factor pronóstico en las pacientes con cáncer de mama Triple Negativo

Introduction Triple Negative breast cancers account for between 12 and 17% of all breast carcinomas. They are a heterogeneous group with different subgroups. The inflammatory reaction produced by the host in response to the disease can be quantified through intratumoral lymphocyte infiltration (tils). Objectives To evaluate intratumoral lymphocyte infiltration (tils), as an independent prognostic factor, in the core biopsies of patients with Triple Negative breast cancer who underwent neoadjuvant chemotherapies. To relate it to the pathological response obtained after surgery. Materials and method Patients with Triple Negative breast carcinoma who underwent neoadjuvant chemotherapy in the Mastology Unit of the Breast Clinic and the Italian Hospital of La Plata were retrospectively selected between the years 2014 and 2017. A sample of 36 patients was obtained. Results Out of a total of 36 patients, 24 showed stromal tils less than 50% and 12 greater than or equal to 50%. 16.7% of tumours with tils less than 50% and half of tumours with tils greater than or equal to 50% presented a complete pathological response after neoadjuvant chemotherapy treatment. In relation to intratumoral tils, 6 tumors of 32 with tils less than 50% (18.8%) and 4 of 4 (100%) with tils > or equal to 50% presented a complete pathological response after neoadjuvant chemotherapy treatment. Conclusions In our series of cases, we observe that there is a relationship between the percentage of tils and the pathological response obtained after treatment with neoadjuvant chemotherapy, being a prognostic factor in patients with triple negative breast cancer

Seroprevalence and risk factor associated with respiratory viral pathogens in dual-purpose cattle of Aguachica, Rio de Oro, and La Gloria municipalities in Cesar department, Colombia.

AIM: The research was conducted to determine the seroprevalence and risk factor associated with respiratory viral pathogens in dual-purpose cattle of Aguachica, Rio de Oro and La Gloria municipalities in Cesar department, Colombia. MATERIALS AND METHODS: The seroprevalence study was done from the random sampling (n=1000) of blood collected from 29 dual-purpose herds, located in three municipalities (Aguachica, Rio de Oro, and La Gloria) of Cesar department. The presence of antibodies against bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial virus (BRSV), bovine viral diarrhea virus (BVDV), and bovine parainfluenza-3 virus (BPI-3V) in the samples was detected by indirect enzyme-linked immunosorbent assay. Epidemiological data were obtained using a questionnaire administered to the owner or manager of each herd. RESULTS: The overall highest seroprevalence was observed for BHV-1 (94.7%), followed by BRSV (98.6%), BVDV (35.2%), and BPI-3V (47.1%). Regarding the seroprevalence by municipalities, there was a statistical association (p<0.05) for BVDV; however, for BRSV, BHV-1, and BPI-3V, no statistical association was found (p>0.05) between seropositive values and the municipalities, indicating that animal was seropositive in similar proportions in the three municipalities. Female sex and older animals (>24 months) were a significant risk factor for BHV-1 and BPI-3V infection. Regarding the clinical signs, there was a statistical association (p<0.05) between the seropositive values of BVDV and most of clinical signs observed, except for abortion. CONCLUSION: This research confirms the high seroprevalence of the respiratory viral pathogens in nonvaccinated cattle within the study areas. Therefore, appropriate sanitary management practices and routine vaccination programs should be adopted to reduce the seroprevalence of these infectious agents.

High prevalence of persistently infected animals from bovine viral diarrhea in Colombian cattle.

BACKGROUND: Bovine Viral Diarrhea Virus (BVDV) is associated with gastrointestinal, respiratory and reproductive diseases of livestock across the world that causes continuous economic losses in the cattle industry. This virus can establish a persistent infection (PI) in calves after the fetal infection, making BVDV positive catle carriers and primary reservoirs which will constantly transmit the virus to healthy and new-born animals. For this reason, the detection of the PI animals in herds is the first line of prevention of the viral infection. RESULTS: In this study, PI animals were detected in five different regions of Colombia through RT-PCR techniques and confirmed by sequencing. BVDV genotypes were determined using one fragment of the 5'UTR. It was found a 7% BVDV prevalence in animals and 22% in farms; and genotype 1 was identified as a single genotype for all of the samples. All samples were BVDV 1a. CONCLUSION: This is the first report in Colombia with higher prevalence rates compared with other places in the world, turned out to be of great importance for the ranchers, the vaccine producers and animal health control parties.

Antibiotic susceptibility of Staphylococcus aureus isolated from subclinical bovine mastitis cases and in vitro efficacy of bacteriophage.

Staphylococcus aureus is an opportunistic pathogen that may cause severe infections in livestock, and represents the major cause of mastitis in dairy cows. Currently, instead of using antibiotics, new strategies are sought to reduce this clinical health problem. The aim of this study was to determine the efficacy of phage therapy to kill S. aureus strains obtained from farms located at the State of Guanajuato, México. Thirty-six S. aureus strains from cow milk with subclinical mastitis were isolated and identified, and the susceptibility to antibiotics and four phages also isolated in this work was tested. It was found that more of 90% of S. aureus isolates were not susceptible to six or more antibiotics, and 100% were resistant to penicillin, dicloxacillin, cefotaxime, ampicillin and cephalothin, and 81 and 77%, to tetracycline and cefuroxime, respectively. Fortunately, 100% of S. aureus isolates were susceptible to phages used in this work, which was detected as clear zones using specific phage. It was shown for the first time, that phages used in this study are active against pathogenic S. aureus and might be incorporated into the therapy as an important tool for the control of staphylococcal bovine mastitis, specially to antibiotic-resistant S. aureus strains isolated in farm located at the state of Guanajuato, México; and its use might be extended to other regions inside or outside the country.

Estimating the numbers of pregnant women infected with Zika virus and infants with congenital microcephaly in Colombia, 2015-2017.

BACKGROUND: Colombia experienced a Zika virus (ZIKV) outbreak in 2015-2016. To assist with planning for medical and supportive services for infants affected by prenatal ZIKV infection, we used a model to estimate the number of pregnant women infected with ZIKV and the number of infants with congenital microcephaly from August 2015 to August 2017. METHODS: We used nationally reported cases of symptomatic ZIKV disease among pregnant women and information from the literature on the percent of asymptomatic infections to estimate the number of pregnant women with ZIKV infection occurring August 2015-December 2016. We then estimated the number of infants with congenital microcephaly expected to occur August 2015-August 2017. To compare to the observed counts of infants with congenital microcephaly due to all causes reported through the national birth defects surveillance system, the model was time limited to produce estimates for February-November 2016. FINDINGS: We estimated 1140-2160 (interquartile range [IQR]) infants with congenital microcephaly in Colombia, during August 2015-August 2017, whereas 340-540 infants with congenital microcephaly would be expected in the absence of ZIKV. Based on the time limited version of the model, for February-November 2016, we estimated 650-1410 infants with congenital microcephaly in Colombia. The 95% uncertainty interval for the latter estimate encompasses the 476 infants with congenital microcephaly reported during that approximate time frame based on national birth defects surveillance. INTERPRETATION: Based on modeled estimates, ZIKV infection during pregnancy in Colombia could lead to 3-4 times as many infants with congenital microcephaly in 2015-2017 as would have been expected in the absence of the ZIKV outbreak. FUNDING: This publication was made possible through support provided by the Bureau for Global Health, U.S. Agency for International Development under the terms of an Interagency Agreement with Centers for Disease Control and Prevention.

Point prevalence of gastrointestinal parasites in double purpose cattle of Rio de Oro and Aguachica municipalities, Cesar state, Colombia.

Gastrointestinal parasites are one of the most important health problems in cattle worldwide, as they cause economic losses in the herds. Twenty - seven double purpose herds were visited to determine the prevalence of gastrointestinal parasites in cattle at the Rio de Oro and Aguachica municipalities. Overall, 862 fecal samples were collected in three age groups: <12months, 12-24months and >24months. Stool samples were taken directly from the rectum and refrigerated until processing. For parasite determination, fecal samples were processed using coprological techniques. The parasitic genera were identified by egg or infective larval morphology. The global prevalence of gastrointestinal parasites was 83.2%, being the highest values for Eimeria sp. (77.9%), Strongyloides sp. (10.8%) and Haemonchus sp. (8.5%). Regarding the prevalence by municipalities, there was no statistical association (P>0.05) indicating that the prevalence was similar in the two municipalities. Regarding the results for Eimeria sp., different degrees of positivity were observed, reflecting that there was statistical association (P<0.05) with respect to the age group, suggesting that adult animals may act as infection source for calves. Likewise, there was statistical association (P<0.05) between the prevalence for Strongyloides sp., Haemonchus sp. and Trichostrongylus sp. with respect to the age group. It is concluded that there is a high prevalence of gastrointestinal parasites in dual-purpose cattle in the municipalities under study, and that it could be controlled by improving the hygienic conditions of the herds, and informing the farmer about parasite control programs.

Ahorro del sistema de salud por la regulación directa de precios de venta de medicamentos biotecnológicos en Colombia / Savings in the Health System due to the Direct Regulation of the Sale Prices of Biotechnological Medicines in Colombia / Poupança no sistema de saúde pela regulamentação direta de preços de venda de medicamentos biotecnológicos na Colômbia

Resumen Se desarrolló un análisis retrospectivo sobre las ventas de trece biotecnológicos regulados, entre junio del 2010 y junio del 2014, en dos escenarios: valores facturados después de la regulación de precios y valores supuestos, calculados a partir del precio de venta promedio de los seis meses anteriores a la regulación, más el índice de precios al consumidor en salud. La diferencia entre ambos escenarios supone un ahorro al sistema. Los biotecnológicos analizados generaron un ahorro de USD $95 000 000 en dicho periodo; en el primer año el 10.2%, el segundo año el 17.2% y en el tercero el 30.5%. El biotecnológico que más ahorro representó fue el rituximab (40,9%), equivalente a USD $38 510 787. La regulación directa de precios de medicamentos biotecnológicos le ha generado ahorros significativos al sistema de salud, visto desde las ventas registradas en Audifarma. Probablemente, el ahorro económico que ha generado esta política es superior a lo estimado inicialmente por el Gobierno.

Abstract We developed a retrospective analysis on the sales of thirteen biotechnological regulated medicines between June, 2010, and June, 2014, in two scenarios: amounts billed after the price and assumed value regulation, calculated based on the average sale price during the six months prior to the regulation, plus the health consumer price index. The difference between both scenarios entails a saving for the system. The biotechnological medicines analyzed generated savings for US $95 Million in said period; 10.2% during the first year, 17.2% during the second, and 30.5% during the third. The biotechnological medicine that generated the most savings was rituximab (40.9%), equivalent to US $38,510,787. The direct regulation of biotechnological medicines has generated significant savings for the healthcare system, as seen from the sales registered by Audifarma. Probably, the economic savings generated by this policy are above the initial government estimates.

Resumo Análise retrospectiva sobre as vendas de treze biotecnológicos regulados entre junho de 2010 e junho de 2014 desenvolvida em dois cenários: valores faturados após regulamentação de preços e valores supostos, calculados a partir do preço de venda médio dos seis meses prévios à regulamentação, mais o índice de preços ao consumidor em saúde. A diferença entre ambos cenários supõe poupança para o sistema. Os biotecnológicos analisados geraram poupança de USD $95 000 000 nesse período; no primeiro ano o 10.2%, o segundo ano o 17.2% e no terceiro o 30.5%. O biotecnológico que mais poupança gerou foi o rituximab (40,9%), equivalente a USD $38 510 787. A regulamentação direta de preços de medicamentos biotecnológicos gerou poupança significativa ao sistema de saúde, visto desde as vendas registradas em Audifarma. Provavelmente, a poupança econômica gerada por esta política é superior do estimado inicialmente pelo Governo.

Kinetic Constants for Biological Ammonium and Nitrite Oxidation Processes Under Sulfide Inhibition.

Inhibition of nitrification by sulfide was assessed using sludge obtained from a steady-state nitrifying reactor. Independent batch activity assays were performed with ammonium and nitrite as substrate, in order to discriminate the effect of sulfide on ammonium and nitrite oxidation. In the absence of sulfide, substrate affinity constants (K S,NH4 = 2.41 ± 0.11 mg N/L; K s, NO2 = 0.74 ± 0.03 mg N/L) and maximum specific rates (q max,NH4 = 0.086 ± 0.008 mg N/mg microbial protein h; q max,NO2 = 0.124 ± 0.001 mg N/mg microbial protein h) were determined. Inhibition of ammonium oxidation was no-competitive (inhibition constant (K i , NH4 ) of 2.54 ± 0.12 mg HS(-)-S/L) while inhibition of nitrite oxidation was mixed (competitive inhibition constant (K' i , NO2 ) of 0.22 ± 0.03 mg HS(-)-S/L and no-competitive inhibition constant (K i , NO2 ) of 1.03 ± 0.06 mg HS(-)-S/L). Sulfide has greater inhibitory effect on nitrite oxidation than ammonium oxidation, and its presence in nitrification systems should be avoided to prevent accumulation of nitrite. By simulating the effect of sulfide addition in a continuous nitrifying reactor under steady-state operation, it was shown that the maximum sulfide concentration that the sludge can tolerate without affecting the ammonium consumption efficiency and nitrate yield is 1 mg HS(-)-S/L.

Incidencia del transtorno de estres postraumático en pacientes atendidos en el servicio de urgencias del Hospital Regional Simón Bolívar con herida toracoabdominal por arma de fuego y/o cortopunzante / Post traumatic stress disorder in firearm wound or steelarm wound in thorax and/or abdomen

El trastorno del estrés postraumático (TSPT) es una entidad nosológica clasificada desde 1980 por el DSM III, asociado a eventos traumáticos extraordinarios para el paciente y se presenta al cabo de mínimo 6 horas. El estudio abarca una muestra de 31 pacientes, seleccionados por haber sufrido herida por arma de fuego o cortopunzante en tórax y/o abdomen, de los cuales 16 cumplieron los criterios para el DSM III-R para el TSPT. Se encontró que el criterio que mas se cumplía en la población estudiada era el criterio referente a revivir el evento (26 pacientes) (criterio B). El item que más cumplieron los 31 pacientes fué el referido a alteración psicológica ante situaciones similares al evento (criterio B4) correspondiendo al 100 por ciento de población estudiada; de los pacientes que desarrollaron el TSPT todos presentaron hipervigilancia con una significancia estadística (p<0.0001). El estudio permite mostrar que el TSPT si se presenta en nuestra población además permite sugerir que los pacientes con las características establecidas para el presente estudio ameritan un control psicológico a mediano plazo como mínimo