Therapeutic mechanism of Shenbing Decoction Ⅲ for renal fibrosis in chronic kidney disease: a study with network pharmacology, molecular docking and validation in rats / 南方医科大学学报

OBJECTIVE@#To observe the effect of Shenbing Decoction Ⅲ for improving renal function and pathology in rats with 5/6 nephrectomy and analyze its therapeutic mechanism for renal fibrosis in chronic kidney disease using network pharmacology combined with molecular docking.@*METHODS@#Forty male SD rats were randomized into two groups to receive two-staged 5/6 nephrectomy (n=30) or sham operation (n=10), and 2 weeks after the final operation, serum creatinine level of the rats was measured. The rats with nephrectomy were further randomized into Shenbing Decoction Ⅲ group, losartan group and model group for daily treatment with the corresponding drugs via gavage starting at 1 week after 5/6 nephrectomy. After 16 weeks of treatment, serum creatinine and urea nitrogen levels of the rats were measured, and HE staining and Western blotting were used to examine the changes in renal pathology and fibrosis-related factors. Network pharmacology combined with molecular docking study was performed to explore the therapeutic mechanism Shenbing Decoction Ⅲ against renal fibrosis in chronic kidney disease, and Western blotting was used to verify the expressions of the core targets.@*RESULTS@#Compared with those in the model group, the rats receiving 5/6 nephrectomy and Shenbing Decoction Ⅲ treatment showed significantly reduced serum creatinine and urea nitrogen levels, lessened renal pathologies, and improvement of the changes in epithelial mesenchymal transition-related proteins. Network pharmacological analysis showed that the main active ingredients of Shenbing Decoction Ⅲ were acacetin, apigenin, eupatilin, quercetin, kaempferol and luteolin, and the key targets included STAT3, SRC, CTNNB1, PIK3R1 and AKT1. Molecular docking study revealed that the active ingredients of Shenbing Decoction Ⅲ had good binding activity to the key targets. Western blotting showed that in rats with 5/6 nephrectomy, treatment with Shenbing Decoction Ⅲ obviously restored the protein expression of STAT3, PI3K, and AKT in renal tissue.@*CONCLUSION@#Shenbing Decoction Ⅲ can reduce renal injury induced by 5/6 nephrectomy in rats, and its therapeutic effects are mediated possibly by its main pharmacologically active ingredients that alleviate renal fibrosis via modulating multiple targets including STAT3, PIK3R1, and AKT1.

Analysis of frequency and molecular genetics of Jk (a-b-) phenotype among blood donors from Jining area / 中华医学遗传学杂志

OBJECTIVE@#To screen for Jk(a-b-) phenotype among blood donors from Jining area and explore its molecular basis to enrich the rare blood group bank for the region.@*METHODS@#The population who donated blood gratuitously at Jining Blood Center from July 2019 to January 2021 were selected as the study subjects. The Jk(a-b-) phenotype was screened with the 2 mol/L urea lysis method, and the result was confirmed by using classical serological methods. Exons 3 to 10 of the SLC14A1 gene and its flanking regions were subjected to Sanger sequencing.@*RESULTS@#Among 95 500 donors, urea hemolysis test has identified three without hemolysis, which was verified by serological method as the Jk(a-b-) phenotype and demonstrated no anti-Jk3 antibody. The frequency of the Jk(a-b-) phenotype in Jining area is therefore 0.0031%. Gene sequencing and haplotype analysis showed that the genotypes of the three samples were JK*02N.01/JK*02N.01, JK*02N.01/JK-02-230A and JK*02N.20/JK-02-230A, respectively.@*CONCLUSION@#The splicing variant of c.342-1G>A in intron 4, missense variants of c.230G>A in exon 4, and c.647_ 648delAC in exon 6 probably underlay the Jk(a-b-) phenotype in the local population, which is different from other regions in China. The c.230G>A variant was unreported previously.

Effective substances and mechanism of Yishen Guluo Mixture in treatment of chronic glomerulonephritis based on metabolomics and serum pharmacochemistry / 中国中药杂志

This study aimed to investigate the effective substances and mechanism of Yishen Guluo Mixture in the treatment of chronic glomerulonephritis(CGN) based on metabolomics and serum pharmacochemistry. The rat model of CGN was induced by cationic bovine serum albumin(C-BSA). After intragastric administration of Yishen Guluo Mixture, the biochemical indexes related to renal function(24-hour urinary protein, serum urea nitrogen, and creatinine) were determined, and the efficacy evaluations such as histopathological observation were carried out. The serum biomarkers of Yishen Guluo Mixture in the treatment of CGN were screened out by ultra-performance liquid chromatography-quadrupole time-of-flight/mass spectrometry(UPLC-Q-TOF-MS) combined with multivariate statistical analysis, and the metabolic pathways were analyzed. According to the mass spectrum ion fragment information and metabolic pathway, the components absorbed into the blood(prototypes and metabolites) from Yishen Guluo Mixture were identified and analyzed by using PeakView 1.2 and MetabolitePilot 2.0.4. By integrating metabolomics and serum pharmacochemistry data, a mathematical model of correlation analysis between serum biomarkers and components absorbed into blood was constructed to screen out the potential effective substances of Yishen Guluo Mixture in the treatment of CGN. Yishen Guluo mixture significantly decreased the levels of 24-hour urinary protein, serum urea nitrogen, and creatinine in rats with CGN, and improved the pathological damage of the kidney tissue. Twenty serum biomarkers of Yishen Guluo Mixture in the treatment of CGN, such as arachidonic acid and lysophosphatidylcholine, were screened out, involving arachidonic acid metabolism, glycerol phosphatide metabolism, and other pathways. Based on the serum pharmacochemistry, 8 prototype components and 20 metabolites in the serum-containing Yishen Guluo Mixture were identified. According to the metabolomics and correlation analysis of serum pharmacochemistry, 12 compounds such as genistein absorbed into the blood from Yishen Guluo Mixture were selected as the potential effective substances for the treatment of CGN. Based on metabolomics and serum pharmacochemistry, the effective substances and mechanism of Yishen Guluo Mixture in the treatment of CGN are analyzed and explained in this study, which provides a new idea for the development of innovative traditional Chinese medicine for the treatment of CGN.

Caspase-1/-11 participates in LPS-induced sepsis-associated acute kidney injury by cleaving GSDMD / 生理学报

The present study was aimed to investigate whether Gasdermin D (GSDMD)-mediated pyroptosis participated in lipopolysaccharide (LPS)-induced sepsis-associated acute kidney injury (AKI), and to explore the role of caspase-1 and caspase-11 pyroptosis pathways in this process. The mice were divided into four groups: wild type (WT), WT-LPS, GSDMD knockout (KO) and KO-LPS. The sepsis-associated AKI was induced by intraperitoneal injection of LPS (40 mg/kg). Blood samples were taken to determine the concentration of creatinine and urea nitrogen. The pathological changes of renal tissue were observed via HE staining. Western blot was used to investigate the expression of pyroptosis-associated proteins. The results showed that the concentrations of serum creatinine and urea nitrogen in the WT-LPS group were significantly increased, compared with those in the WT group (P < 0.01); whereas serum creatinine and urea nitrogen in the KO-LPS group were significantly decreased, compared with those in the WT-LPS group (P < 0.01). HE staining results showed that LPS-induced renal tubular dilatation was mitigated in GSDMD KO mice. Western blot results showed that LPS up-regulated the protein expression levels of interleukin-1β (IL-1β), GSDMD and GSDMD-N in WT mice. GSDMD KO significantly down-regulated the protein levels of IL-1β, caspase-11, pro-caspase-1, caspase-1(p22) induced by LPS. These results suggest that GSDMD-mediated pyroptosis is involved in LPS-induced sepsis-associated AKI. Caspase-1 and caspase-11 may be involved in GSDMD cleavage.

Development and clinical application of hydrogel formulations containing papain and urea for wound healing

Abstract Hydrogels are used for wound treatment, as they may contain one or more active components and protect the wound bed. Papain is one of the active substances that have been used with this purpose, alongside urea. In this paper, carboxypolymethylene hydrogels containing papain (2% and 10% concentrations) and urea (5% concentration) were produced. Physical-chemical stability was performed at 0, 7, 15 and 30 days at 2-8ºC, 25ºC and 40ºC, as well as the rheological aspects and proteolytic activity of papain by gel electrophoresis. Clinical efficacy of the formulations in patients with lower limb ulcers was also evaluated in a prospective, single-center, randomized, double-blind and comparative clinical trial. The results showed 7-day stability for the formulations under 25ºC, in addition to approximately 100% and 15% of protein activity for 10% and 2% papain hydrogel, respectively. The rheological profile was non-Newtonian for the 10% papain hydrogel tested. There were no significant differences regarding the mean time for healing of the lesions, although 10% papain presented a better approach to be used in all types of tissue present in the wound bed.

Helicobacter pylori infection and UBT-13C values are associated with changes in body mass index in children and adults / La infección por Helicobacter pylori y los valores de UBT-13C se asocian con el índice de masa corporal en niños y adultos

BACKGROUND: The urea breath test (UBT-13C) is a non-invasive technique that allows the diagnosis and confirmation of eradication of Helicobacter pylori infection. Aim: To evaluate H. pylori positivity and values of UBT-13C among infected Chilean children and adults, and to analyze its variation in relation to sex, nutritional status, and age of the patients. Material and Methods: Retrospective study of 1141 patients aged 6 to 94 years, with an indication for a UBT-13C either for diagnosis or for confirmation of eradication of H. pylori infection. 13C enrichment was measured using an infrared spectrometer calculating the delta 13C values before and after the ingestion of 13C marked urea. The clinical data of the patients were obtained at the time of the examination. Results: We included 241 children and 900 adults. Infected children obtained lower UBT-13C delta values than infected adults (16.1 ± 8.7 and 37 ± 52.9, respectively). The rates of infection were higher in males who were recruited for diagnosis. Significant differences were obtained between positivity for H. pylori in overweight and obese children but not adults. UBT-13C titers were significantly associated with the body mass index (BMI) only in adults. Conclusions: H. pylori infection rates are similar between sexes and are higher in children probably because of selection bias. In children, H. pylori positivity is associated with higher BMI and excess malnutrition although with similar UBT-13C values. In adults, H. pylori infection is not related with BMI, but a higher BMI impacts UBT-13C titers.

ANTECEDENTES: La prueba de aliento con urea (UBT-13C) es una técnica no invasiva que permite el diagnóstico y confirmación de erradicación de la infección por Helicobacter pylori. Objetivo: Evaluar los valores de UBT- 13C en niños y adultos chilenos infectados y analizar su variación en relación al sexo, diagnóstico nutricional y edad de los pacientes. Material y Métodos: Estudio retrospectivo de 1.141 pacientes de 6 a 94 años. El enriquecimiento de13C se midió usando un espectrómetro de infrarrojos, calculando el delta 13C antes y después de la ingesta de urea marcada con 13C. Los datos clínicos de los pacientes se obtuvieron al momento del examen. Resultados: Incluimos 241 niños y 900 adultos con valores delta de UBT-13C de 16,1 ± 8,7 frente a 37 ± 52,9, respectivamente. Las tasas de infección fueron mayores en los hombres reclutados para el diagnóstico. Se obtuvieron diferencias significativas entre la positividad para H. pylori en niños con sobrepeso y obesidad, pero no en adultos. Los títulos de UBT-13C se asociaron significativamente con el índice de masa corporal (IMC) solo en adultos. Conclusiones: Las tasas de infección por H. pylori son similares entre los sexos y aumentan en los niños probablemente debido al sesgo de selección. En niños, la positividad para H. pylori se asocia con un IMC más alto y malnutrición por exceso, aunque con valores similares de UBT-13C. En los adultos, la infección por H. pylori no se relaciona con el IMC ni con la obesidad, pero el aumento del IMC afecta los títulos de UBT-13C.

Utilidad de la fórmula HUGE para el diagnóstico de enfermedad renal crónica en el anciano / Usefulness of the HUGE formula for the diagnosis of chronic kidney disease in the elderly

INTRODUCCIÓN: La enfermedad renal crónica se encuentra en ascenso.Prevenir o retardar su progresión mediante la aplicación de estrategias dirigidas al diagnóstico precoz es esencial. OBJETIVO: Evaluar la utilidad de la fórmula HUGE para el diagnóstico de Enfermedad Renal Crónica en el anciano. MATERIAL Y MÉTODO: Se realizó un estudio observacional descriptivo prospectivo y de corte longitudinal en 260 adultos mayores que ingresaron en los servicios de Geriatría y Medicina Interna del Hospital Clínico Quirúrgico "Hermanos Ameijeiras" en el período enero de 2019 y junio de 2020. RESULTADOS: El 58,5% de la muestra de estudio fueron mujeres. La edad promedio fue de 77,1 ± 7,3 años. La enfermedad renal crónica estuvo presente en el 64,2% de los pacientes. Se observó mayor frecuencia de pacientes con daño renal (32,7%) al emplear la formula CKD­ EPI en comparación con los identificados al emplear la fórmula HUGE (25,0%). Al estimar la concordancia entre ambas fórmulas se observó un estadístico kappa (k) de 0,814 (IC de 95%:0,7370 - 0,8909; p < 0,001). La sensibilidad de la fórmula de HUGE fue de un 76,5% (IC de 95%: 66,9% - 86,1%) y la especificidad de un 100% (99,7% - 100%). El valor predictivo positivo fue de 100 % (IC de 95%: 99,2% - 100%) y el negativo de 89,7% (85,2% - 94,2%). CONCLUSIONES: La fórmula CKD-EPI identifica daño renal en mayor porcentaje, en estadios precoces. Por el contrario, la fórmula de HUGE, detecta el daño renal en un porcentaje mayor en estadios más avanzados.La concordancia para diagnosticar daño renal entre la fórmula CKD-EPI y HUGE fue muy buena. La fórmula HUGE es útil, sensible y específica para evaluar la enfermedad renal crónica en los adultos mayores.

INTRODUCTION: Chronic kidney disease is on the rise. Preventing or delaying its progression through the application of strategies aimed at early diagnosis is essential. OBJECTIVE: To evaluate the usefulness of the HUGE formula for the diagnosis of Chronic Kidney Disease in the elderly. MATERIAL AND METHOD: A prospective, descriptive and longitudinal observational study was carried out in 260 older adults who were admitted to the Geriatrics and Internal Medicine services of the "Hermanos Ameijeiras" Surgical Clinical Hospital between January 2019 and June 2020. RESULTS: 58.5% of the study sample was women. The mean age was 77.1 ± 7.3 years. CKD was present in 64.2% of the patients. A higher frequency of patients with kidney damage (32.7%) was observed when using the CKD ­ EPI formula compared to those identified when using the HUGE (25.0%). When estimating the concordance between both formulas, a kappa statistic (k) of 0.814 (95% CI: 0.7370 - 0.8909; p < 0.001) was observed. The sensitivity of the HUGE formula was 76.5% (95% CI: 66.9% - 86.1%) and the specificity was 100% (99.7% - 100%). The positive predictive value was 100% (95% CI: 99.2% - 100%) and the negative predictive value was 89.7% (85.2% - 94.2%). CONCLUSIONS: The CKD-EPI formula identifies kidney damage in a higher percentage, in early stages. On the contrary, the HUGE formula detects kidney damage in a higher percentage in more advanced stages. The concordance to diagnose kidney damage between the CKD-EPI and HUGE formula was very good. The HUGE formula is useful, sensitive, and specific for evaluating chronic kidney disease in older adults.

Effect of kefir on increased apoptosis in liver and kidney in cisplatin toxicity / Efecto del kéfir sobre el aumento de la apoptosis en el hígado y los riñones en la toxicidad del cisplatino

SUMMARY: Cisplatin is a chemotherapeutic agent inducing liver and kidney damage. In this study, we intended to investigate the impact of kefir beverage, an essential probiotic and functional food, on liver and kidney damage induced by cisplatin. Wistar albino rats were divided into four groups: Control, Cisplatin (single dose of 7 mg/kg, intraperitoneal), Kefir (2 ml/d, 7 d, oral gavage), and Cisplatin+Kefir (CK). At the end of day 7, animals were euthanized. Blood, kidney, and liver tissue samples were collected. For both tissues, biochemically ALT, AST, Urea, Creatine; histomorphologically, hematoxylin-eosin, Masson's Trichrome, and immunohistochemical staining of caspase-3, a marker of apoptosis, were performed. Serum urea and creatinine levels of the Cisplatin group were significantly higher than the Control group (p<0.05). In the CK group, kefir consumption decreased urea and creatinin levels approached to Control and Kefir groups. Cisplatin resulted in higher ALT and AST activities, indicating hepatocellular damage, compared to the Control group (p<0.05). Kefir consumption decreased ALT activities approached to both the Control and Kefir group. Histomorphological observations were in agreement biochemical results. In liver and kidney tissues, structural damage was observed with an increase in collagen fibers in the Cisplatin group, and Caspase-3 activity was immunohistochemically higher than in the other groups. In the CK group, collagen fiber increase, structural damage, and Caspase-3 activities were less than in the Cisplatin group. Kefir consumption alleviated liver and kidney damage. However, more research is required to understand such effect of kefir better.

RESUMEN: El cisplatino es un agente quimioterapéutico que induce daño hepático y renal. En este estudio, intentamos investigar el efecto del kéfir, un alimento funcional y probiótico esencial, en el daño hepático y renal inducido por el cisplatino. Se dividieron ratas albinas Wistar en cuatro grupos: control, cisplatino (dosis única de 7 mg/kg, intraperitoneal), kéfir (2 ml/día, 7 días, sonda oral) y cisplatino + kéfir (CK). Al final del día 7, los animales fueron sacrificados. Se recolectaron muestras de sangre, riñón y tejido hepático. Se determinó ALT, AST, Urea y Creatina; Para el análisis histomorfológico, se realizaron tinciones con hematoxilina-eosina, tricrómico de Masson y para inmunohistoquímica, caspasa-3, un marcador de apoptosis. Los niveles séricos de urea y creatinina del grupo de cisplatino fueron significativamente más altos que los del grupo de control (p<0,05). En el grupo CK, el consumo de kéfir disminuyó los niveles de urea y creatinina acercándose a los grupos Control y Kéfir. El cisplatino resultó en actividades más altas de ALT y AST, lo que indica daño hepatocelular, en comparación con el grupo Control (p<0.05). El consumo de kéfir disminuyó las actividades de ALT tanto en el grupo Control como en el de Kéfir. Las observaciones histomorfológicas coincidieron con los resultados bioquímicos. En tejidos hepáticos y renales se observó daño estructural con aumento de fibras colágenas en el grupo de Cisplatino, y la actividad de Caspasa-3 fue inmunohistoquímicamente mayor que en los otros grupos. En el grupo de CK, el aumento de las fibras colágenas, el daño estructural y las actividades de Caspasa-3 fueron menores que en el grupo Cisplatino. El consumo de kéfir mejoró el daño hepático y renal. Sin embargo, se requiere más investigación para comprender mejor el efecto del kéfir.

Verificación y transferencia de intervalos de referencia de variables bioquímicas de rutina / Verification and transfer of reference intervals of routine biochemical variables

Introducción. El correcto análisis en la interpretación de los resultados de cualquier analito biológico es esencial para la salud del paciente y está fuertemente ligado a contrastar dichos resultados con los intervalos biológicos referenciales que estén acorde a la población que está siendo analizada diariamente. El objetivo de este artículo, fue establecer intervalos referenciales (IR) en adultos para glicemia, urea, creatinina, ácido úrico, colesterol total y triglicéridos en un laboratorio clínico y comparar los valores obtenidos con los incluidos en los insertos para ese rango de edad. Metodología. La población fue de 561 adultos de ambos sexos, aparentemente sanos, que acudieron a Biomasterclin Laboratorio en Valencia, Venezuela, y cuyas edades fueron de 57,1±18,1 años. Resultados. Los IR obtenidos fueron glicemia 63,0-108,8 mg/dL, urea 17,7-54,9 mg/dL, creatinina 0,60-1,41 mg/dL, ácido úrico 0,89-7,26 mg/dL, colesterol total 78,5-251,1 mg/dL y triglicéridos 39,5-176,0 mg/dL. Los IR propuestos por la casa comercial empleada para la determinación de la glicemia y la creatinina pudieron ser transferidos a la población evaluada, mientras que el resto de los IR no. Conclusión. Debido a las diferencias que se presentan entre los IR en los estuches comerciales comparados con los de la población de individuos que acuden a los laboratorios clínicos, se hace necesario establecer IR para ser empleados en cada laboratorio clínico

The correct analysis in the interpretation of the results of any biological analyte is essential for the health of the patient and it is strongly linked to comparing those results with reference ranges that are in accordance with the population that is being analyzed on a daily basis. The objective of this study was to establish reference ranges in adults for glycemia, urea, creatinine, uric acid, total cholesterol and triglycerides in a clinical laboratory and compare the values obtained with those included in the inserts for the corresponding age group. Methodology. The population consisted of 561 apparently healthy adults of both sexes that attended Biomasterclin Laboratorio in Valencia, Venezuela, whose ages were 57.1±18.1 years. Results. The reference ranges obtained for glycemia were 63.0- 108.8 mg/dL, urea 17.7-54.9 mg/dL, creatinine 0.60-1.41 mg/dL, uric acid 0.89- 726 mg/dL, total cholesterol 78.5-251.1 mg/dL and triglycerides 39.5-176.0 mg/ dL. The reference ranges proposed by the commercial kits used for the determination of glycemia and creatinine could be transferred to the evaluated population, while the rest of the reference ranges could not. Conclusion. Due to the differences that occur between the reference ranges in commercial kits compared to those of the population of individuals who attend clinical laboratories, it is necessary to establish reference values in each clinical laboratory

Assessment of Serum Uric Acid, Urea, and Glucose Levels and Associated Factors among Breast Cancer Patients Attending A Tertiary Hospital in Bahirdar, Ethiopia: A Comparative CrossSectional Study

BACKGROUND: Breast cancer is currently become a major public health problem in both developed and developing regions, it is one of the most common surgical problems in Ethiopia. Therefore, this study assessed serum uric acid, urea, and glucose levels and associated factors among benign, malignant breast cancer patients and apparently healthy women attending at Felege-Hiwot comprehensive Specialized Hospital. METHODS: Hospital based comparative cross-sectional study was conducted among benign, malignant breast cancer patients and apparently healthy women attending at Felege-Hiwot Comprehensive Specialized Hospital. Out of 178 study participants 66 benign and 23 malignant fine needle aspirate cytology confirmed breast cancer patients and 89 apparently healthy women, included. Multivariable logistic regression models used to measure the strength of associations. A P value of < 0.05 was considered statistically significant. RESULTS: Majority of the study participants, 81(91%) controls, 55(83.3%) benign, and 17(73.9%) malignant cases were premenopausal. Serum glucos144.47±74.35 and uric acid 6.84±2.54 levels were significantly elevated in malignant cases than control (p-value< 0.05). Patients with malignant status were 4.38 times more likely to have hyperglycemia (AOR=4.38, 95%CI: 1.98-19.97) and 5.53 times more likely have hyperuricemia (AOR=20.43-95% CI: 6.80- 61.23), 4 times more likely to have uremia (AOR=4.09, 95% CI: 1.06-15.91) compared to apparently healthy women. CONCLUSION: Serum glucose, and uric acid levels were significantly higher in malignant and benign cases compared with apparently healthy women. Family history of breast cancer, body mass index, systolic hypertension, comorbidity, residence and menopausal status were significantly associated with hyperglycemia, uremia and hyperuricemia.

Indicators of full value feeding rations for dairy cows / Indicadores de rações de valor total para vacas leiteiras

This article presents the results of the level of feeding and the health status of dairy cows in a commercial dairy farm on the content of the main components in milk (fat, protein, urea). The aim of the research was to study the milk productivity and composition of milk of cows, to analyze the level of feeding and the content of basic nutrients in the diet of the farm. The farm breeds purebred Holstein cattle with a high genetic potential for productivity. The milking herd was formed in 2009 on the basis of 600 heads of Holstein-Friesian heifers imported from Hungary, as well as 65 heads of Holsteinized heifers of Ukrainian selection from Ukraine in 2015. Today the livestock numbers about 1,500 head of cattle, of which there are about 900 breeders. On the territory of the farm there are: 3 cowsheds for keeping cows, an insemination room, a milking parlor with a parallel installation of the Delaval company, in which 48 cows are milked for one milking, the ABK, where the manager’s office, livestock technician, accounting is located, and a mini-hotel with dining room and lounges. Dairy bases are equipped with auto-drinkers, ventilation, plumbing, electric lighting, manure removal mechanisms, and a milking installation. The object of the research was Holstein cows in the amount of 483 heads of Aina Dairy Farm LLP. The studies were carried out according to generally accepted zootechnical methods using modern equipment for conducting analyzes and interstate and state standards. The research results showed that the milk productivity of cows averaged 19.5 kg per day, the fat content 4.3%, the protein 3.9%, the number of somatic cells 230.5 thousand units / ml, urea 45.3 mg / 100 ml respectively. Analyzing the [...].

Este artigo apresenta os resultados do nível de alimentação e do estado de saúde de vacas leiteiras em uma fazenda comercial leiteira sobre o conteúdo dos principais componentes do leite (gordura, proteína, ureia). O objetivo da pesquisa foi estudar a produtividade e composição do leite de vacas, analisar o nível de alimentação e o teor de nutrientes básicos na dieta da fazenda. A fazenda produz gado holandês de raça pura com alto potencial genético de produtividade. O rebanho leiteiro foi formado em 2009 com base em 600 cabeças de novilhas Holstein-Friesian importadas da Hungria, bem como 65 cabeças de novilhas holsteinizadas da seleção ucraniana em 2015. Hoje o gado totaliza cerca de 1.500 cabeças de gado, das quais existem cerca de 900 criadores. No território da fazenda existem: 3 estábulos para criação de vacas, uma sala de inseminação, uma sala de ordenha com instalação paralela da empresa Delaval, na qual são ordenhadas 48 vacas para cada ordenha, a ABK, onde fica o escritório do gestor, pecuária técnica, a contabilidade está localizada, e um mini-hotel com refeitório e salões. As bases leiteiras são equipadas com bebedouros automáticos, ventilação, encanamento, iluminação elétrica, mecanismo de remoção de esterco e instalação de ordenha. O objeto da pesquisa foram vacas da raça holandesa no valor de 483 cabeças da Aina Dairy Farm LLP. Os estudos foram realizados de acordo com métodos zootécnicos geralmente aceitos, utilizando equipamentos modernos para a realização de análises e padrões interestaduais e estaduais. Os resultados da pesquisa mostraram que a produtividade do leite das vacas era em média 19,5 kg por dia, o teor de gordura 4,3%, a proteína 3,9%, o número de células somáticas 230,5 mil unidades / ml, ureia 45,3 mg / 100 ml respectivamente. A análise do nível de ureia no leite [...].

Supplementation of crossbred cows with maize and urea in tropical pasture / Suplementação de vacas mestiças com milho e ureia em pastagem tropical

This research article aims to evaluate the effect of total replacement of corn by soybean meal and urea on intake and apparent digestibility of dry matter and its components, production and composition of milk and feeding behavior of lactating cows grazing, with intermittent stocking Mombaça grass (Megathyrsus maximus cv. Mombaça). Twelve milking cows were distributed in a triple 4 x 4 latin square. Experimental treatments consisted of four soybean meal replacement levels by corn more urea (0; 33; 66; 100%). The grass has an average content of crude protein and neutral detergent fiber of 19% and 59%, respectively. The replacement of soybean meal by corn and urea did not affect the intake and digestibility of nutrients. A linear reduction of milk production was observed, but there was no change in milk production corrected to 4.0% of fat. The milk components (g/kg) of fat, protein, lactose, and total solids were not altered, as well as feeding behavior. Under the conditions of this study, the replacement of the diets is suitable for crossbred dairy cows in lactation third medium, producing in average of 12.5 kg/day-1 when kept in quality pastures.(AU)

Este artigo de pesquisa tem como objetivo avaliar o efeito da substituição total do milho pelo farelo de soja e ureia sobre o consumo e a digestibilidade aparente da matéria seca e de seus componentes, a produção e a composição do leite e o comportamento alimentar de vacas em lactação mantidas em pastos capim-mombaça (Megathyrsus maximus cv. Mombaça) manejado sob lotação intermitente. Doze vacas em lactação foram distribuídas em um quadrado latino triplo 4 x 4. Os tratamentos experimentais consistiram de quatro níveis de substituição do farelo de soja pelo milho mais ureia (0; 33; 66; 100%). O capim-mombaça apresentou um teor médio de proteína bruta e de fibra em detergente neutro de 19% e 59%, respectivamente. A substituição do farelo de soja por milho e ureia não afetou o consumo e a digestibilidade dos nutrientes. Observou-se redução linear da produção de leite, mas não houve alteração na produção de leite corrigida para 4,0% de gordura. Os componentes do leite (g/kg): gordura, proteína, lactose e sólidos totais não foram alterados, assim como o comportamento ingestivo dos animais. Nas condições deste estudo, a substituição total do milho pelo farelo de soja e ureia nas dietas é adequada para vacas mestiças leiteiras em terço médio de lactação, produzindo, em média, 12,5 kg / dia-1 quando mantidas em pastagens de qualidade.(AU)

Amplification of urea detection based on pH-sensitive liposomes

BACKGROUND: This study aimed to develop an amplification method of urea detection based on pHsensitive liposomes. RESULTS: The urease covalently immobilized on the magnetic particles and the pH-sensitive liposomes encapsulating ferricyanide were added to the cyclic-voltammeter cell solution where urea was distributed. The conversion of urea into carbonic acid seemed to induce a pH decrease that caused a reduction in the electrostatic repulsion between the headgroups of weakly acidic 1,2-dipalmitoyl-sn-glycero3-succinate. The reduction induced the liposomes to release potassium ferricyanide that was encapsulated inside. The effects of urea concentration and pH value were investigated. A specific concentration (0.5 mg/mL) of the urea solution was set to observe the response. The activity of urease was reversible with respect to the pH change between 7 and 5. The sensitivity of this detection was almost identical to the comparable techniques such as an enzyme-linked immunosorbent assay and a field-effect transistor. CONCLUSIONS: In summary, the methodology developed in this study was feasible as a portable, rapid, and sensitive method.

Morphogenetic, structural and production traits of marandu grass under nitrogen rates in Neo soil / [Características morfogênicas, estruturais e produtivas do capim-marandu sob doses de nitrogênio em Neossolo]

Most sandy soils have low natural fertility and low levels of organic matter, making nitrogen (N) fertilization essential. Thus, five doses of N were applied (0, 75, 125, 175 and 225mg dm-³) in a randomized block design to evaluate the effects of nitrogen fertilization on the morphogenetic, structural and production characteristics of Brachiaria brizantha cv. Marandu in a Quartzarenic neosoil. The doses of N did not affect the height of the canopy. The leaf elongation rate, final leaf length and number of live leaves increased linearly at the doses of N. Leaf appearance rate, stem elongation rate, leaf lifespan, phyllochron, leaf senescence rate and tiller density showed a quadratic response to the rates There was also an effect of N rates in herbage mass, leaf mass, stem mass, which increased linearly. Brachiaria brizantha cv. Marandu cultivated in Quartzarenic neosoil requires higher doses of N, 175 and 225mg dm-³. Under these conditions, increases in its morphogenetic, structural and productive characteristics are observed. These findings may not be repeated in the most fertile soils with the greatest capacity to supply N.(AU)

A maioria dos solos arenosos tem baixa fertilidade natural e baixos teores de matéria orgânica, tornando a adubação com nitrogênio (N) essencial. Assim, foram aplicadas cinco doses de N (0, 75, 125, 175 e 225mg dm-³) em delineamento de blocos ao acaso, para se avaliarem os efeitos da adubação com nitrogênio nas características morfogênicas, estruturais e produtivas da Brachiaria brizantha cv. Marandu, em um Neossolo Quartzarênico. As doses de N não afetaram a altura do dossel. A taxa de alongamento foliar, o comprimento final da folha e o número de folhas vivas aumentaram linearmente em função das doses de N. A taxa de aparecimento de folhas, a taxa de alongamento do caule, o tempo de vida da folha, o filocrono, a taxa de senescência foliar e a densidade de perfilhos apresentaram resposta quadrática às doses de N. A massa da forragem, a massa foliar e a massa do caule aumentaram linearmente. Brachiaria brizantha cv. Marandu cultivada em Neossolo Quartzarênico requer maiores doses de N, 175 e 225mg dm-³. Nessas condições, são observados aumentos em suas características morfogenéticas, estruturais e produtivas. Esses achados podem não se repetir nos solos mais férteis e com maior capacidade de suprir N.(AU)

Comparison of dialysis dose through real-time Kt/V by ultraviolet absorbance of spent dialysate, single-pool Daugirdas II, and Kt/BSA according to sex and age / Comparação da dose de diálise através do Kt/V em tempo real pela absorbância ultravioleta do dialisato gasto, Daugirdas II de pool único e Kt/BSA de acordo com sexo e idade

ABSTRACT Background: Kt/V OnLine (Kt/VOL) avoids inaccuracies associated with the estimation of urea volume distribution (V). The study aimed to compare Kt/VOL, Kt/V Daugirdas II, and Kt/BSA according to sex and age. Methods: Urea volume distribution and body surface area were obtained by Watson and Haycock formulas in 47 patients. V/BSA was considered as a conversion factor from Kt/V to Kt/BSA. Dry weight was determined before the study. Kt/VOL was obtained on DIALOG machines. Results: Pearson correlation between Kt/VOL vs Kt/VII and Kt/VOL vs Kt/BSA was significant for males (r = 0.446, P = 0.012 and r = -0.476 P = 0.007) and individuals < 65 years (0.457, P = 0.019 and -0.549 P = 0.004), but not for females and individuals ≥ 65 years. V/BSA between individuals < 65 and individuals ≥ 65 years were 18.28 ± 0.15 and 18.18 ± 0.16 P = 0.000). No agreement between Kt/VII vs Kt/BSA. Men and individuals > 65 years received a larger dialysis dose than, respectively, females and individuals < 65 years, in the comparison between Kt/VOL versus Kt/VII. V/BSA ratios among men and women were respectively 18.29 ± 0.13 and 18.12 ± 0.15 P = 0.000. Conclusions: Kt/VOL allows recognition of real-time dose regardless of sex and age.

RESUMO Introdução: O Kt/V OnLine (Kt/VOL) evita imprecisões associadas à estimativa da distribuição do volume de uréia (V). O estudo teve como objetivo comparar Kt/VOL, Kt/V Daugirdas II e Kt/BSA de acordo com sexo e idade. Métodos: A distribuição do volume de uréia e área de superfície corporal foram obtidas pelas fórmulas de Watson e Haycock em 47 pacientes. V/BSA foi considerado um fator de conversão de Kt/V para Kt/BSA. O peso seco foi determinado antes do estudo. Kt/VOL foi obtido através de máquinas DIALOG. Resultados: A correlação de Pearson entre Kt/VOL vs Kt/VII e Kt/VOL vs Kt/BSA foi significativa para os homens (r = 0,446, P = 0,012 e r = -0,476 P = 0,007) e indivíduos < 65 anos (0,457, P = 0,019 e -0,549 P = 0,004), mas não para mulheres e indivíduos ≥ 65 anos. A V/BSA entre indivíduos <65 e indivíduos ≥ 65 anos foi 18,28 ± 0,15 e 18,18 ± 0,16 P = 0,000). Sem concordância entre Kt/VII vs Kt/BSA. Homens e indivíduos > 65 anos receberam maior dose de diálise do que, mulheres e indivíduos <65 anos, respectivamente, na comparação entre Kt/VOL versus Kt/VII. As razões V/BSA entre homens e mulheres foram, respectivamente, 18,29 ± 0,13 e 18,12 ± 0,15 P = 0,000. Conclusões: Kt/VOL permite o reconhecimento da dose em tempo real, independentemente do sexo e idade.

Comparison between hematological and biochemical changes caused by conventional and metronomic chemotherapies in the treatment of canine transmissible venereal tumor / Comparação entre as alterações hematológicas e bioquímicas ocasionadas pela quimioterapia convencional e quimioterapia metronômica no tratamento do tumor venéreo transmissível canino

This study aimed to report the hematological and biochemical changes caused by conventional and metronomic chemotherapies, using vincristine sulfate to treat canine Transmissible Venereal Tumor (TVT). Twelve dogs were selected, six of them for the group receiving conventional chemotherapy (G1), and six dogs for the group receiving metronomic chemotherapy (G2). The G1 group received vincristine sulfate once a week at the dose of 0.75mg/m² until the tumor had disappeared with treatment, and the G2 group was treated with vincristine sulfate three times a week at the dose of 0.25mg/m2 until the tumor had disappeared. Before and after chemotherapy treatment, hematological and biochemical blood tests were performed to evaluate the main alterations caused by both chemotherapeutic models. Dogs undergoing conventional chemotherapy had significant leukocyte changes (p<0.05), causing neutropenia and leukopenia. In dogs undergoing metronomic chemotherapy, leukocytes remained within the reference range. Half of the dogs in group G1 had normochromic, normocytic anemia. The only biochemical alteration observed was the increase of urea in group G2. Thus, metronomic chemotherapy for the treatment of TVT with vincristine sulfate proved to be an excellent method for treatment, with fewer adverse effects, especially in maintaining the leukogram of dogs within normal range and reducing the number of anemia in animals during treatment.(AU)

Esta pesquisa teve como objetivo relatar as alterações hematológicas e bioquímicas causadas pelo tratamento quimioterápico convencional e pela quimioterapia metronômica, utilizando-se sulfato de vincristina para o tratamento do tumor venéreo transmissível canino(TVTC). Foram selecionados 12 cães, sendo seis para o grupo que recebeu quimioterapia convencional (G1) e seis cães para o grupo que recebeu quimioterapia metronômica (G2). O grupo G1 recebeu sulfato de vincristina, uma vez por semana, na dose de 0,75mg/m2, até o desaparecimento do tumor e o grupo G2 foi tratado com sulfato de vincristina, três vezes por semana, na dose de 0,25mg/m2, até o desaparecimento do tumor. Antes e após o tratamento quimioterápico foram realizados exames hematológicos e bioquímicos sanguíneos para avaliação das principais alterações causadas pelos dois modelos quimioterápicos. Os cães submetidos à quimioterapia convencional tiveram alterações leucocitárias significativas (p<0,05), causando uma leucopenia por neutropenia enquanto nos cães, submetidos à quimioterapia metronômica, os leucócitos mantiveram-se dentro do intervalo de referência. A metade dos cães do grupo G1 tiveram uma anemia do tipo normocítica normocrômica. A única alteração bioquímica observada foi o aumento da ureia no grupo G2. Desta forma, a quimioterapia metronômica para o tratamento do TVT com sulfato de vincristina, demonstrou ser um excelente método para a cura do animal, com menores reduções de efeitos adversos, sobretudo, na manutenção do leucograma dos cães e na redução de animais com anemia.(AU)

Valor del indice urea/creatinina en orina aislada para estimar el hipercatabolismo proteico grave en pacientes ventilados / Value of the urea/creatinine index in isolated urine to estimate severe protein hypercatabolism in ventilated patients

RESUMEN Objetivo: Estudiar la capacidad discriminativa de hipercatabolismo proteico grave del índice urea/creatinina en orina aislada en pacientes críticos ventilados. Metodos: Estudio prospectivo, observacional. Incluyó 52 pacientes sin insuficiencia renal. Variables: nitrógeno urinario total estimado a partir de la urea en orina de 24 horas al segundo (T1) y cuarto día (T2) e índice urea/creatinina en orina aislada previo a la recolección de orina de 24 horas. Resultados: Presentaron hipercatabolismo proteico grave (nitrógeno urinario total estimado > 15g) 14 pacientes (26,9%) en T1 y 29 (55,7%) en T2. El 84% de los pacientes presentaron bajo riesgo nutricional por la escala Nutrition Risk in the Critically Ill. En el segundo día, la correlación de Pearson del nitrógeno urinario total estimado con el índice urea/creatinina fue: 0,272 (p = 0,051) y en el cuarto día: 0,276 (p = 0,048). El índice urea/creatinina al cuarto día, tuvo una tendencia a mayor discriminación del hipercatabolismo proteico grave que el Acute Physiology and Chronic Health Evaluation II y Nutrition Risk in the Critically Ill (AUC 0,741 versus 0,669 y 0,656, IC95%: 0,602 - 0,880; 0,519 - 0,818 y 0,506 - 0,806 respectivamente). El valor de corte optimo del índice urea/creatinina para diagnóstico de hipercatabolismo proteico grave fue de 16,15 con una sensibilidad de 79,31% (IC95%: 59,74 - 91,29), especificidad de 60,87% (IC95%: 38,78 - 79,53), valor predictivo positivo 71,88% (IC95%: 53,02 - 85,60), valor predictivo negativo 70,0% (IC95%: 45,67 - 87,18), LR (+) 2,03 (IC95%: 1,18 - 3,49) y LR (-) 0,34 (IC95%: 0,16 - 0,74). Conclusión: El índice urea/creatinina realizado al cuarto día tiene un discreto valor para estimar el hipercatabolismo proteico grave por nitrógeno urinario total y no reemplaza al mismo en pacientes críticos ventilados sin falla renal. Por su razonable sensibilidad podría ser utilizado como cribado para identificar a quien tomar la muestra de orina de 24 horas.

ABSTRACT Objective: To study the ability of the urea/creatinine index to identify severe protein catabolism from the isolated urine of critically ventilated patients. Methods: This was a prospective, observational study. It included 52 patients without kidney failure. Variables: total urinary nitrogen estimated from the urea in 24-hour urine on the second (T1) and fourth days (T2) and urea/creatinine index in isolated urine before 24-hour urine collection. Results: Severe protein hypercatabolism (estimated total urinary nitrogen > 15g) was present in 14 patients (26.9%) at T1 and in 29 (55.7%) at T2. Eighty-four percent of patients had low nutritional risk by the Nutrition Risk in the Critically Ill score. At T1, the Pearson correlation between the estimated total urinary nitrogen and the urea/creatinine index was 0.272 (p = 0.051), and at T2 it was 0.276 (p = 0.048). The urea/creatinine index at T2 had a tendency to better discriminate severe protein hypercatabolism than Acute Physiology and Chronic Health Evaluation II and Nutrition Risk in the Critically Ill (AUC 0.741 versus 0.669 and 0.656, 95%CI: 0.602 - 0.880; 0.519 - 0.818 and 0.506 - 0.806, respectively). The optimal cutoff value of the urea/creatinine index for the diagnosis of severe protein hypercatabolism was 16.15, with a sensitivity of 79.31% (95%CI: 59.74 - 91.29), specificity of 60.87% (95%CI: 38.78 - 79.53), positive predictive value 71.88% (95%CI: 53.02 - 85.60), negative predictive value 70.0% (95%CI: 45.67 - 87.18), LR (+) 2.03 (95%CI: 1.18 - 3.49), and LR (-) 0.34 (95%CI: 0.16 - 0.74). Conclusion: The urea/creatinine index measured on the fourth day has a certain ability to estimate severe protein hypercatabolism (as defined by estimated total urinary nitrogen) but does not replace total urinary nitrogen in critically ventilated patients without kidney failure. Due to its reasonable sensitivity, it could be used as a screen to identify which patients to take a 24-hour urine sample from.

Mycelial biomass cultivation of Lentinus crinitus / Crescimento micelial de Lentinus crinitus

Lentinus crinitus is a medicinal basidiomycete, little studied regarding the basic cultivation conditions, which is used in bioremediation and consumed by native Indians from the Brazilian Amazon. Also, it produces a fungal secondary metabolite panepoxydone that has been described as an essential regulator of the inflammatory and immune response. This study aimed to evaluate basic conditions of temperature, pH, and nitrogen concentration and source in the cultivation of L. crinitus mycelial biomass. In order to evaluate fungal growth temperature, 2% malt extract agar (MEA) medium, pH 5.5, was utilized from 19 to 40 °C. For pH, MEA had pH adjusted from 2 to 11 and cultivated at 28 °C. Urea or soybean meal was added to MEA to obtain final concentration from 0.5 and 16 g/L of nitrogen, pH of 5.5, cultivated at 28 °C. The best temperature growth varies from 31 to 34 ºC and the optimal one is 32.7º C, and the best pH ranges from 4.5 to 6.5 and the optimal one is 6.1. Protein or non-protein nitrogen concentration is inversely proportional to the mycelial biomass growth. Nitrogen concentrations of 2.0 g/L soybean meal and urea inhibit mycelial biomass growth in 11% and 12%, respectively, but high concentrations of 16.0 g/L nitrogen inhibit the growth in 46% and 95%, respectively. The fungus is robust and grows under extreme conditions of temperature and pH, but smaller adaptation with increasing nitrogen concentrations in the cultivation medium, mainly non-protein nitrogen.

Lentinus crinitus é um basidiomiceto medicinal consumido por índios nativos da Amazônia brasileira. Este fungo tem sido estudado quanto ao potencial de biorremediação de metais, mas ainda carece de estudos sobre às condições básicas de crescimento. L. crinitus produz panepoxidona - um metabólito secundário fúngico - descrito como regulador da resposta inflamatória e imune em células animais. Este trabalho teve como objetivo avaliar as condições básicas de temperatura, pH e concentração e fonte de nitrogênio para o crescimento micelial de L. crinitus. O fungo foi crescido em meio agar extrato de malte a 2% (MEA), pH 5,5 e mantido entre 19 e 40 °C. Para a avaliação de pH o MEA teve o pH ajustado de 2 a 11 e o crescimento foi realizado a 28 °C. As fontes de nitrogênio estudadas foram a uréia e o farelo de soja adicionado ao MEA para obter entre 0,5 a 16 g/L de nitrogênio, pH de 5,5, cultivado a 28 ° C. A melhor faixa temperatura para o crescimento micelial foi de 31 a 34 ºC com ótimo a 32,7 º C; a melhor faixa de pH de 4,5 a 6,5 e com ótimo de 6,1. A concentração de nitrogênio proteico ou não proteico é inversamente proporcional ao crescimento do fungo. Concentrações de nitrogênio de 2,0 g/L reduzem o crescimento da biomassa micelial em 11% e 12%, respectivamente e meios com nitrogênio de 16,0 g/L reduzem o crescimento em 46% e 95%, respectivamente. O fungo é robusto e cresce sob condições extremas de temperatura e pH, mas menor adaptação em meios com alta concentração de nitrogênio, principalmente não proteico.

Desenvolvimento ponderal e parâmetros hematológicos e bioquímicos de cordeiros Pantaneiros submetidos a diferentes manejos de amamentação / [Ponderal development and hematological and biochemical parameters of Pantaneiro lambs subjected to different suckling regimens]

Este estudo teve por objetivo avaliar o desenvolvimento ponderal e a dinâmica dos parâmetros hematológicos e bioquímicos de cordeiros Pantaneiros submetidos a diferentes manejos de amamentação dos 15 aos 43 dias. Foram separados 30 cordeiros em três diferentes grupos (n=10). Os grupos foram caracterizados conforme o tempo de permanência das ovelhas com suas crias em diferentes sistemas de amamentação: MAM24 - ovelhas e cordeiros 24 horas em conjunto; MAM12 - ovelhas e cordeiros 12 horas em conjunto durante a noite; MAM2x30 - ovelhas e cordeiros 30 minutos de manhã e 30 minutos à tarde em conjunto. As coletas de amostras sanguíneas e as pesagens ocorriam a cada sete dias. Houve aumento significativo no peso com o avanço da idade dos cordeiros nos três manejos, mas os tratamentos não diferiram entre si para o ganho de peso. Houve diferenças entre os três tratamentos para a variável hematológica CHGM e para as variáveis bioquímicas AST, glicose, ureia e proteína total. As variáveis bioquímicas foram influenciadas pela faixa etária dos animais. Os diferentes manejos de amamentação não influenciaram o desenvolvimento ponderal dos cordeiros. Não ocorreram alterações patológicas. Alguns parâmetros hematológicos e bioquímicos podem ser influenciados pelo desenvolvimento etário dos cordeiros.(AU)

This study aimed to evaluate the weight development and the dynamics of hematological and biochemical parameters of Pantaneiro lambs submitted to different breastfeeding management from 15 to 43 days. First, 30 lambs were separated into three different groups (n = 10). The groups were characterized according to the length of stay of ewes with their young in different breastfeeding systems: MAM24 - ewes and lambs 24 hours together. MAM12- Sheep and lambs 12 hours together at night. MAM2x30 - sheep and lambs 30 minutes in the morning and 30 minutes in the afternoon together. Blood samples were collected and weighed every seven days. Significant increase in weight was observed with the age of the lambs in the three managements, but the treatments did not differ for weight gain. Differences were identified between the three treatments for the hematological variable CHGM and for the biochemical variables AST, glucose, urea and total protein. Correlating the age of the lambs with the biochemical variables, there was variation influenced by the age of the animals. The different management of breastfeeding did not influence the weight development of the lambs. Hematological and biochemical variations did not represent pathological changes. Some hematological and biochemical parameters may be influenced by the age development of lambs.(AU)

Mineral and organomineral sources of nitrogen to maize agronomic performance / Fontes minerais e organominerais de nitrogênio para aumentar o desempenho agronômico do milho

Nitrogen (N) is one of the nutrients absorbed in great quantity by maize crop. Also, N fertilizers are of high costs and subject to large losses into the agricultural environment. There are various categories of fertilizers known as fertilizers of improved efficiency that can minimize such N losses. The objective of this study was to evaluate the effect of different sources and doses of N in maize agronomic performance. The experiment was installed in randomized blocks, with four replications, designed as a factorial 5 x 5 + 1, constituted by five N sources (urea, urea polymerized, urea with NBPT, organomineral with and without NBPT), five N doses (40, 80, 120, 160, 200 kg ha-1) plus a control (no N supply). The chlorophyll contents and grain yield were evaluated. The results showed no differences for the different N sources, indicating that the organomineral sources are as efficient as the mineral sources. The addition of N fertilizers in increasing doses, regardless of the source tested, has increased the levels of chlorophylls and grain yiled.

O nitrogênio (N) é um dos nutrientes absorvidos em grande quantidade pela cultura do milho. Além disso, os fertilizantes nitrogenados são de alto custo e sujeitos a grandes perdas no ambiente agrícola. Existem várias categorias de fertilizantes, conhecidas como fertilizantes de maior eficiência, que podem minimizar essas perdas de N. O objetivo deste estudo foi avaliar o efeito de diferentes fontes e doses de N no desempenho agronômico do milho. O experimento foi instalado em blocos casualizados, com quatro repetições, delineadas como fatorial 5 x 5 + 1, constituído por cinco fontes de N (uréia, uréia polimerizada, uréia com NBPT, organomineral com e sem NBPT), cinco doses de N (40, 80, 120, 160, 200 kg ha-1) mais um controle (sem fornecimento de N). O conteúdo de clorofila e o rendimento de grãos foram avaliados. Os resultados não mostraram diferenças para as diferentes fontes de N, indicando que as fontes organomineral são tão eficientes quanto as fontes minerais. A adição de fertilizantes N em doses crescentes, independentemente da fonte testada, aumentou os níveis de clorofilas e rendimento de grãos