Manejo inicial de la hiperamonemia aguda en pediatría / Initial management of acute hyperammonemia in pediatrics

La hiperamonemia constituye una emergencia médica. No existen publicaciones que hagan referencia a la disponibilidad de recursos, insumos y conocimientos necesarios para el manejo inicial de esta por parte del pediatra en nuestro país, pero, según la experiencia de los autores, los recursos necesarios no se encuentran disponibles los 365 días del año en una gran porción de nuestro territorio. Sobre la base de este estado de situación, de una revisión bibliográfica internacional sobre el tema y de la experiencia de los autores, se elaboraron una serie de recomendaciones para el manejo pediátrico inicial de esta emergencia, que tienen como objetivo poder reducir las deficiencias, permitir una sospecha clínica adecuada que lleve a un diagnóstico y tratamiento de emergencia oportunos, con utilización racional de recursos farmacológicos (algunos de ellos de alto costo), para reducir la morbimortalidad que asocia la patología.

Hyperammonemia is a medical emergency. There are no publications regarding the availability of resources, supplies, and knowledge necessary for the initial management of hyperammonemia by pediatricians in Argentina; however, according to the authors' experience, the necessary resources are not available all year round in a large portion of our territory. Based on such state of affairs, an international bibliographic review on this topic and the authors' experience, we developed a series of recommendations for the initial pediatric management of this emergency, with the objective of reducing deficiencies, allowing adequate clinical suspicion leading to a timely diagnosis and emergency management and a rational use of pharmacological resources (some of which are costly) to reduce the morbidity and mortality associated with hyperammonemia.

Breath-by-breath measurement of exhaled ammonia by acetone-modifier positive photoionization ion mobility spectrometry via online dilution and purging sampling / 药物分析学报

Exhaled ammonia(NH3)is an essential noninvasive biomarker for disease diagnosis.In this study,an acetone-modifier positive photoionization ion mobility spectrometry(AM-PIMS)method was developed for accurate qualitative and quantitative analysis of exhaled NH3 with high selectivity and sensitivity.Acetone was introduced into the drift tube along with the drift gas as a modifier,and the characteristic NH3 product ion peak of(C3H6O)4NH4+(K0=1.45 cm2/V·s)was obtained through the ion-molecule reaction with acetone reactant ions(C3H6O)2H+(K0=1.87 cm2/V·s),which significantly increased the peak-to-peak resolution and improved the accuracy of exhaled NH3 qualitative identification.Moreover,the interference of high humidity and the memory effect of NH3 molecules were significantly reduced via online dilution and purging sampling,thus realizing breath-by-breath measurement.As a result,a wide quantitative range of 5.87-140.92 μmol/L with a response time of 40 ms was achieved,and the exhaled NH3 profile could be synchronized with the concentration curve of exhaled CO2.Finally,the analytical capacity of AM-PIMS was demonstrated by measuring the exhaled NH3 of healthy subjects,demon-strating its great potential for clinical disease diagnosis.

Gene cloning and enzymatic activity analysis of phenylalanine ammonia-lyase from Sinopodophyllum hexandrum (Royle) Ying / 生物工程学报

Phenylalanine ammonia-lyase (PAL) is the key entry enzyme of plant phenylpropanoid pathway. It plays an important role in the biosynthesis of podophyllotoxin, an anti-tumor lignan that is currently produced from its main natural source Sinopodophyllum hexandrum (Royle) Ying. In this study, we cloned the gene ShPAL encoding phenylalanine ammonia-lyase by RT-PCR from the root of S. hexandrum ecotype inhabited in the Aba' district, Sichuan, based on its public SRA transcriptome data-package. Bioinformatics analyses showed that the ShPAL-encoded protein is composed of 711 amino acids, contains the conserved domains of PAL, and has the signature motif within the active center of aromatic ammonia-lyases. Moreover, ShPAL protein was predicted to have a secondary structure mainly composed of α-helix and random coil, a typical 'seahorse' shape monomer tertiary structure, and a homologous tetramer three-dimensional structure by Swiss-Modelling. The phylogenetic lineage analysis indicated ShPAL was of the highest sequence identity and the shortest evolutionary distance with the PAL of Epimedium sagittatum from the same Berberidaceae family. Subcellular localization experiments showed that ShPAL protein was mainly distributed in the cytoplasm, despite of a minority on the endoplasmic reticulum membrane. Furthermore, ShPAL protein was recombinantly expressed in Escherichia coli and purified by histidine-tag affinity chromatography. Its enzymatic activity was determined up to 20.91 U/mg, with the optimum temperature of 41 ℃ and pH of 9.0. In contrast, the enzyme activity of its F130H mutant decreased by about 23.6%, yet with the same trends of change with temperature and pH, confirming that phenylalanine at this position does affect the substrate specificity of PAL. Both the wild type and the mutant have relatively poor thermostability, but good pH-stability. These results may help to further investigate the regulatory role of PAL in the process of podophyllotoxin biosynthesis and advance the heterologous synthesis of podophyllotoxin to protect the germplasm resource of S. hexandrum. They also demonstrate that ShPAL has a potential application in biochemical industry and biomedicine.

Diagnostic value of a combined serology-based model for minimal hepatic encephalopathy in patients with compensated cirrhosis / 中华检验医学杂志

Objective:To investigate the diagnostic accuracy of serological indicators and evaluate the diagnostic value of a new established combined serological model on identifying the minimal hepatic encephalopathy (MHE) in patients with compensated cirrhosis.Methods:This prospective multicenter study enrolled 263 compensated cirrhotic patients from 23 hospitals in 15 provinces, autonomous regions and municipalities of China between October 2021 and August 2022. Clinical data and laboratory test results were collected, and the model for end-stage liver disease (MELD) score was calculated. Ammonia level was corrected to the upper limit of normal (AMM-ULN) by the baseline blood ammonia measurements/upper limit of the normal reference value. MHE was diagnosed by combined abnormal number connection test-A and abnormal digit symbol test as suggested by Guidelines on the management of hepatic encephalopathy in cirrhosis. The patients were randomly divided (7∶3) into training set ( n=185) and validation set ( n=78) based on caret package of R language. Logistic regression was used to establish a combined model of MHE diagnosis. The diagnostic performance was evaluated by the area under the curve (AUC) of receiver operating characteristic curve, Hosmer-Lemeshow test and calibration curve. The internal verification was carried out by the Bootstrap method ( n=200). AUC comparisons were achieved using the Delong test. Results:In the training set, prevalence of MHE was 37.8% (70/185). There were statistically significant differences in AMM-ULN, albumin, platelet, alkaline phosphatase, international normalized ratio, MELD score and education between non-MHE group and MHE group (all P<0.05). Multivariate Logistic regression analysis showed that AMM-ULN [odds ratio ( OR)=1.78, 95% confidence interval ( CI) 1.05-3.14, P=0.038] and MELD score ( OR=1.11, 95% CI 1.04-1.20, P=0.002) were independent risk factors for MHE, and the AUC for predicting MHE were 0.663, 0.625, respectively. Compared with the use of blood AMM-ULN and MELD score alone, the AUC of the combined model of AMM-ULN, MELD score and education exhibited better predictive performance in determining the presence of MHE was 0.755, the specificity and sensitivity was 85.2% and 55.7%, respectively. Hosmer-Lemeshow test and calibration curve showed that the model had good calibration ( P=0.733). The AUC for internal validation of the combined model for diagnosing MHE was 0.752. In the validation set, the AUC of the combined model for diagnosing MHE was 0.794, and Hosmer-Lemeshow test showed good calibration ( P=0.841). Conclusion:Use of the combined model including AMM-ULN, MELD score and education could improve the predictive efficiency of MHE among patients with compensated cirrhosis.

Assessment of myocardial viability in ischemic heart disease by integrated PET/MR / 中华核医学与分子影像杂志

Objective:To evaluate the value of integrated PET/MR in assessing myocardial viability in ischemic heart disease.Methods:A total of 39 patients (28 males, 11 females; age (60.1±12.0) years) diagnosed with ischemic heart disease in Xuanwu Hospital, Capital Medical University were retrospectively enrolled from September 2020 to December 2021. All patients underwent cardiac 13N-NH 3·H 2O and 18F-FDG PET/MR examinations. Late gadolinium enhancement (LGE) sequence was included in MRI scan. PET and MRI images were analyzed and myocardial viability of each myocardial segment was evaluated according to the American Heart Association (AHA) 17 segment method. The extent of left ventricular infarcted myocardium was measured based on PET and MRI images. Weighted Kappa test was used to evaluate the agreement of PET and MRI in assessing myocardial viability. The extent of infarcted myocardium measured by PET and MRI was compared by paired- t test, and Pearson correlation analysis was used to assess the correlation between them. Results:There was a moderate agreement between PET and MRI in assessing myocardial viability ( Kappa=0.532, P<0.001), with the agreement rate of 69.83%(463/663). There was no significant difference but strong correlation between the extents of infarcted myocardium measured by PET and MRI ((23.89±14.23)% vs (23.55±11.90)%; t=-0.24, P=0.809; r=0.79, P<0.001). In segments with normal perfusion and metabolism on PET, 22.52% (100/444) showed abnormal enhancement on MRI. On the other hand, 39.89% (73/183) of the segments classified as non-viable on MRI showed normal or viable on PET. Conclusion:Integrated PET/MR is able to take full advantage of the complementary nature of PET and MRI, achieving the comprehensive and accurate evaluation of myocardial viability.

Characterization of highly active tyrosine ammonia lyase and its application in biosynthesis of p-coumaric acid / 生物工程学报

p-coumaric acid is one of the aromatic compounds that are widely used in food, cosmetics and medicine due to its properties of antibacterium, antioxidation and cardiovascular disease prevention. Tyrosine ammonia-lyase (TAL) catalyzes the deamination of tyrosine to p-coumaric acid. However, the lack of highly active and specific tyrosine ammonia lyase limits cost-effective microbial production of p-coumaric acid. In order to improve biosynthesis efficiency of p-coumaric acid, two tyrosine ammonia-lyases, namely Fc-TAL2 derived from Flavobacterium columnare and Fs-TAL derived from Flavobacterium suncheonense, were selected and characterized. The optimum temperature (55 ℃) and pH (9.5) for Fs-TAL and Fc-TAL2 are the same. Under optimal conditions, the specific enzyme activity of Fs-TAL and Fc-TAL2 were 82.47 U/mg and 13.27 U/mg, respectively. Structural simulation and alignment analysis showed that the orientation of the phenolic hydroxyl group of the conserved Y50 residue on the inner lid loop and its distance to the substrate were the main reasons accounting for the higher activity of Fs-TAL than that of Fc-TAL2. The higher activity and specificity of Fs-TAL were further confirmed via whole-cell catalysis using recombinant Escherichia coli, which could convert 10 g/L tyrosine into 6.2 g/L p-coumaric acid with a yield of 67.9%. This study provides alternative tyrosine ammonia-lyases and may facilitate the microbial production of p-coumaric acid and its derivatives.

Emergency psychological intervention of acute ammonia leakage event / 中华劳动卫生职业病杂志

Objective: To analyze the situation of emergency psychological intervention in an acute ammonia leakage event, and to provide reference for emergency response. Methods: In August 2020, the emergency treatment of 65 patients admitted by Zhangqiu District People's Hospital Affiliated to Jining Medical College of Shandong Province in June 2019 in the ammonia tank car leakage incident was analyzed, the psychological intervention in emergency after the incident was collected, the anxiety and depression were evaluated by symptom checklist 90 (SCL-90) , and targeted psychological intervention was implemented according to the psychological evaluation results, And analyze the intervention efficiency. Results: Among the 65 patients, there were 52 cases of ammonia stimulation reaction, 11 cases of mild poisoning and 2 cases of moderate poisoning. There were 60 cases of chest tightness and dyspnea, 11 cases of bloody sputum, 58 cases of sore throat, 43 cases of hoarseness, 28 cases of photophobia and tears, 13 cases of blurred vision, 18 cases of nausea and vomiting, and 2 cases of dry and wet rales in the lungs. The scores of somatization, depression, anxiety, hostility, phobia, paranoia and negative coping in patients with mild and moderate poisoning were higher than those in patients with stimulus response (P<0.05) . The effective rate of intervention was 98.7%. Conclusion: Emergency psychological evaluation and intervention in mass public health events are helpful to the treatment of patients.

Ammonia gas for bacterial control in poultry litter

ABSTRACT: The current techniques used in the disinfection of reused poultry litter, such as lime addition, windrowing and plastic cover on the surface, do not guarantee the elimination of pathogenic microorganisms, causing damage to the environment and animal health. Gram negative bacteria, i.e., Salmonella and Escherichia coli, can be transmitted from one batch to another through reused litter, causing health damage to broilers and humans that consume food contaminated by these agents. Our study assessed the effectiveness of the methods plastic cover on the surface (PCS) and plastic cover on the surface with ammonia gas injection (PCSAI) in the control of Gram negative bacteria. The results obtained, both in laboratory conditions (Experiment 1) and in the field (Experiment 2), demonstrate that the method PCSAI with 0.22% ammonia gas had a significant reduction (P 0.05) of Gram negative bacteria in the period of 48 hours This new methodology for disinfecting poultry litter will allow its reuse in a practical and safe way, improving the preservation of the environment, of the health of broilers and consumers of poultry products.

RESUMO: O reaproveitamento de camas aviárias na criação de frangos de corte é uma prática muito utilizada no Brasil. Essa prática reduz custos de produção e contribui na conservação do meio ambiente. As técnicas atuais utilizadas na desinfecção de camas aviárias reaproveitadas, como adição de cal, enleiramento e lona na superfície, não garantem a eliminação de microrganismos patogênicos porque não geram quantidade suficiente de amônia. O gás amônia, em concentrações elevadas, tem efeito biocida. Bactérias Gram negativas, como as Salmonelas e Escherichia coli, podem ser transmitidas de um lote para outro através do reaproveitamento da cama, ocasionando prejuízos para a saúde das aves e dos humanos que consomem alimentos contaminados por estes agentes. Este trabalho avaliou a eficácia do método lona na superfície com injeção de gás amônia no controle de microrganismos Gram negativos. Os resultados obtidos demostraram que esse método controlou os microrganismos Gram negativos num período de 48 horas em camas de frangos de corte reaproveitadas. Assim, essa nova metodologia de desinfecção de camas de aviário permitirá sua reutilização de forma prática e segura, melhorando a saúde das aves e dos consumidores dos produtos avícolas.

Ammonia gas for bacterial control in poultry litter / Gás amônia para controle bacteriano em cama aviária

The current techniques used in the disinfection of reused poultry litter, such as lime addition, windrowing and plastic cover on the surface, do not guarantee the elimination of pathogenic microorganisms, causing damage to the environment and animal health. Gram negative bacteria, i.e., Salmonella and Escherichia coli, can be transmitted from one batch to another through reused litter, causing health damage to broilers and humans that consume food contaminated by these agents. Our study assessed the effectiveness of the methods plastic cover on the surface (PCS) and plastic cover on the surface with ammonia gas injection (PCSAI) in the control of Gram negative bacteria. The results obtained, both in laboratory conditions (Experiment 1) and in the field (Experiment 2), demonstrate that the method PCSAI with 0.22% ammonia gas had a significant reduction (P<0.05) of Gram negative bacteria in the period of 48 hours This new methodology for disinfecting poultry litter will allow its reuse in a practical and safe way, improving the preservation of the environment, of the health of broilers and consumers of poultry products.

O reaproveitamento de camas aviárias na criação de frangos de corte é uma prática muito utilizada no Brasil. Essa prática reduz custos de produção e contribui na conservação do meio ambiente. As técnicas atuais utilizadas na desinfecção de camas aviárias reaproveitadas, como adição de cal, enleiramento e lona na superfície, não garantem a eliminação de microrganismos patogênicos porque não geram quantidade suficiente de amônia. O gás amônia, em concentrações elevadas, tem efeito biocida. Bactérias Gram negativas, como as Salmonelas e Escherichia coli, podem ser transmitidas de um lote para outro através do reaproveitamento da cama, ocasionando prejuízos para a saúde das aves e dos humanos que consomem alimentos contaminados por estes agentes. Este trabalho avaliou a eficácia do método lona na superfície com injeção de gás amônia no controle de microrganismos Gram negativos. Os resultados obtidos demostraram que esse método controlou os microrganismos Gram negativos num período de 48 horas em camas de frangos de corte reaproveitadas. Assim, essa nova metodologia de desinfecção de camas de aviário permitirá sua reutilização de forma prática e segura, melhorando a saúde das aves e dos consumidores dos produtos avícolas.

Semi-rational design improves the catalytic activity of phenylalanine ammonia lyase from Anabaena variabilis / 药学学报

Phenylalanine ammonia lyase (PAL) can catalyze L-phenylalanine to produce trans-cinnamic acid, which is widely used in the fields of pharmacy, food and agriculture. In particular, phenylalanine ammonia lyase from Anabaena variabilis (AvPAL) is the only protein drug for the treatment of phenylketonuria. However, the poor activity and low stability limit the application in industry of AvPAL. In this study, the key amino acids of substrate-binding cavity in AvPAL were identified by screening the single site saturation mutagenesis library. Subsequently, the impact of replacing M222 with the additional 19 amino acids on activity was also evaluated by site-directed mutagenesis. It was found that the kcat values of mutants M222L and M222V were 90% and 60% higher than that of AvPAL, and the kcat/Km was 1.4 and 1.5 times as that of AvPAL. Molecular docking results revealed that the higher activity of M222L and M222V may be due to the increase of hydrophobicity favorable for the substrate-binding cavity. This study is important for elucidating the structure-function relationship of AvPAL.

Molecular cloning and characterization of three phenylalanine ammonia-lyase genes from Schisandra chinensis / 中国天然药物

Phenylalanine ammonia-lyase (PAL), which catalyzes the conversion from L-phenylalanine to trans-cinnamic acid, is a well-known key enzyme and a connecting step between primary and secondary metabolisms in the phenylpropanoid biosynthetic pathway of plants and microbes. Schisandra chinensis, a woody vine plant belonging to the family of Magnoliaceae, is a rich source of dibenzocyclooctadiene lignans exhibiting potent activity. However, the functional role of PAL in the biosynthesis of lignan is relatively limited, compared with those in lignin and flavonoids biosynthesis. Therefore, it is essential to clone and characterize the PAL genes from this valuable medicinal plant. In this study, molecular cloning and characterization of three PAL genes (ScPAL1-3) from S. chinensis was carried out. ScPALs were cloned using RACE PCR. The sequence analysis of the three ScPALs was carried out to give basic characteristics followed by docking analysis. In order to determine their catalytic activity, recombinant protein was obtained by heterologous expression in pCold-TF vector in Escherichia coli (BL21-DE3), followed by Ni-affinity purification. The catalytic product of the purified recombinant proteins was verified using RP-HPLC through comparing with standard compounds. The optimal temperature, pH value and effects of different metal ions were determined. Vmax, Kcat and Km values were determined under the optimal conditions. The expression of three ScPALs in different tissues was also determined. Our work provided essential information for the function of ScPALs.

Hiperamonemia como causa de diálisis no renal / Hyperammonemia as a cause of non-renal dialysis

Resumen La hiperamonemia es una condición frecuente en pacientes cirróticos y en el contexto de una causa no cirrótica se relaciona con aumento en la producción de amonio o alteración en su eliminación. La presentación clínica de esta condición es inespecífica: va desde alteración del comportamiento hasta estado de coma, siendo una de las causas de diálisis no renal por determinados valores o refractariedad a manejo médico. Se presenta el caso de una mujer de 35 años, quien ingresó al servicio de urgencias con alteración del estado de conciencia, niveles de amonio elevados y masa hipervascular en hígado. Los estudios de aminoácidos limitantes del ciclo de la urea y ácido orótico urinario fueron normales y la biopsia de la lesión hepática reportó carcinoma hepático fibrolamelar, al cual se atribuyó la presencia de shunt portosistémico que causaba la hiperamonemia. Se indicó diálisis por persistencia de elevaciones de amonio y poca respuesta al tratamiento médico. Dada la evolución de la paciente, fue necesario reiniciar la terapia reemplazo renal por reaparición de estado encefalopático al suspender la misma. Esta terapia se mantuvo hasta el trasplante hepático que se realizó como tratamiento del carcinoma, con posterior estabilización de niveles de amonio y suspensión de la diálisis.

Abstract Hyperammonemia is a common condition in cirrhotic patients. In the context of a non-cirrhotic cause, this is related to the increase in its production of ammonium or alteration in its elimination. The clinical presentation is nonspecific, from the alteration of the behavior to the coma, being one of the causes of non-renal dialysis due to certain values or refractoriness to medical management. The case of a 35-year-old woman is presented, who is admitted to the emergency department with altered state of consciousness, elevated ammonium levels and hypervascular mass in the liver. Biopsy of the liver lesion reports fibrolamellar liver carcinoma. The presence of a portosystemic shunt that causes hyperammonemia is attributed to this pathology. Dialysis is indicated by persistence of ammonium elevations with little response to medical treatment. In its evolution, it required a restart of renal replacement due to a reappearance of the encephalopathic state when it was suspended. This therapy is maintained until liver transplantation performed as a carcinoma treatment, with subsequent stabilization of ammonium levels and dialysis suspension.

Aerobic stability of tifton 85 silage with and without pre-drying in the sun

The objective of this study was to evaluate pH, ammoniacal nitrogen, and aerobic stability of silage of Tifton 85 grass silage with two dry matter contents at different silos opening times. The experimental design was completely randomized, in a subdivided plots scheme, in which the silages constituted the plots and aerobic exposure times the subplots, with four replications. To verify the aerobic stability of the silages, the temperature and pH were analyzed at seven hours after the silos were opened (1, 24, 48, 72, 96, 120, and 144 hours). The pH reached adequate levels for conservation only after 90 days of fermentation for the silages with and without pre-drying in the sun. Ammoniacal nitrogen remained below the recommended limits in both silages. As for the silage temperature, no loss of aerobic stability was observed. However, the observed pH revealed a break instability after 72 hours when the silos were opened at 28 days, with no changes for the remaining silage periods. It is possible to obtain suitable silages from Tifton 85 with or without pre-warming in the sun, however, a minimum fermentation period of 90 days should be adopted. The studied silages presented high aerobic stability, but when kept silage for only 28 days, they should be consumed by the animals within 48 hours after the supply.

Advances in denitrification microorganisms and processes / 生物工程学报

Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.

Effect of Fluoxetine Hydrochloride on Routine Metabolism of Lambari (Deuterodon iguape, Eigenmann, 1907) and Phantom Shrimp (Palaemon pandaliformis, Stimpson, 1871)

HIGHLIGHTS Fluoxetine increases the metabolic rate and excretion of ammonia in both species. O:N ratio in fish showed higher values in the highest concentrations of fluoxetine. The LC50 - 96 hour values of Palaemon pandaliformis represented greater toxicity. Both species are a good biological model for fluoxetine exposure studies.

Abstract Fluoxetine is an emerging pollutant that acts as a selective serotonin reuptake inhibitor (SSRI) and being a hydrolytic molecule that is photolytically stable and accumulaties in biological tissues, its disposal in the aquatic environment can interfere with the physiology of fish and shrimp. Thus, the objective of this study was to analyze the effects of fluoxetine on routine metabolism (metabolic rate, specific ammonia excretion and O:N ratio) of Deuterodon iguape and Palaemon pandaliformis. For this, five groups of each species, were exposed to different concentrations of fluoxetine for 24 hours (D. iguape) and 2 hours (P. pandaliformis). The results demonstrated that in D. iguape exposure to fluoxetine significantly increased both the metabolic rate by 75%, 85%, 55% and 50% for concentrations of 0.05; 0.1; 0.5 and 1.0 mgL-1, respectively, and the specific ammonia excretion by 40%, 48% and 20% for concentrations of 0.05; 0.1 and 0.5 mgL-1, respectively, when compared with their control. The O:N ratio was statistically greater in concentrations of 0.5 and 1.0 mgL-1. Concerning P. pandaliformis, exposure to fluoxetine increased metabolic rate at concentrations 30.0 and 60.0 µgL-1, and also increased specific ammonia excretion at concentrations 10.0, 30.0 and 60.0 µgL-1, when compared with the control group. It was concluded that exposure to fluoxetine increases the routine metabolism of both species and that at the concentration 1.0 mgL-1, Deuterodon iguape required different energy substrates.

Crecimiento y metabolismo de Fischerella TB22 en medio de cultivo BG11 / Growth and metabolism of Fischerella TB22 in BG110 culture medium

Los microorganismos fijadores de nitrógeno de vida libre, abarcan una gama morfológica que va desde los organismos unicelulares como las bacterias y algunas cianobacterias, hasta multicelulares, filamentosas, por ello es importante conocer cómo se comportan y se puede saber haciendo una curva de crecimiento microbiano. Para este estudio se prepararon 4 fotobioreactores de columna burbujeada con inoculo de Fischerella TB22, se pusieron en aireación constante con 12 horas luz y 12 horas obscuridad durante 40 días con diferentes tratamientos de ajuste de volumen del medio de cultivo y ajuste del pH. El objetivo de este trabajo fue evaluar el crecimiento en biomasa por peso seco, densidad óptica, pH y amonio de Fischerella sp. en medio de cultivo BG110 durante 12 días. Las variables que se midieron de la curva de crecimiento de las cianobacterias, siguieron el patrón de una curva típica de crecimiento microbiano. (AU)

Free-living nitrogen-fixing microorganisms cover a morphological range that goes from unicellular organisms such as bacteria and some cyanobacteria, to multicellular, filamentous, therefore it is important to know how they behave and can be known by makinga microbial growth curve. For this study, 4 bubbled column photobioreactors with Fischerella TB22inoculum were prepared, they were placed in constant aeration with 12 hours of light and 12 hours of darkness for 40 days with different treatments of volumeadjustment of the culture medium and pH adjustment. The objective of this work was to evaluate the biomass growth by dry weight, optical density, pH, and ammonia of Fischerella sp. in the BG110 culture medium for 12 days. The variables that were measured from the growth curve of cyanobacteria followed the pattern of a typical microbial growth curve. (AU)

Intake, nitrogen balance and microbial protein synthesis of steers fed with or without lipid addition / Consumo, balanço de nitrogênio e síntese de proteína microbiana de novilhos alimentados com ou sem adição de lipídios

This study investigated the influence of energy supplementation with or without the addition of lipids on microbial production, microbial synthesis efficiency and nitrogen balance. Eight fistulated steers were used with accessible rumens and kept in individual stalls. Their diets consisted of corn silage; corn silage + concentrate; corn silage + concentrate with addition of lipids in the form of soybean oil; and corn silage + concentrate with addition of lipids in the form of soybean grains. Estimates of microbial protein synthesis were obtained based on the urinary excretion of purine derivatives. The concentrations of ammonia in the rumen were determined immediately at 2, 4, 6 and 8 hours after feeding. The diets with concentrate increased (P<0.05) the microbial protein synthesis and the efficiency of the synthesis and nitrogen balance without a difference between the lipid sources (P>0.05). Concentrated diets presented higher concentrations of urea nitrogen in the serum and urinary urea excretion (P<0.05), but there was no difference between the lipid sources (P>0.05). Energy supplementation, with or without lipid addition, can be used as a strategy to increase the synthesis of the microbial protein in the cattle fed corn silage.

Este estudo investigou a influência da suplementação energética com ou sem adição de lipídios na produção microbiana, eficiência de síntese microbiana e balanço de nitrogênio. Oito novilhos fistulados foram utilizados com rúmen acessível e mantidos em baias individuais. Suas dietas consistiram de silagem de milho; silagem de milho + concentrado; silagem de milho + concentrado com adição de lipídios na forma de óleo de soja; e silagem de milho + concentrado com adição de lipídios na forma de grãos de soja. Estimativas de síntese de proteína microbiana foram obtidas com base na excreção urinária de derivados de purina. As concentrações de amônia no rúmen foram determinadas imediatamente às 2, 4, 6 e 8 horas após a alimentação. As dietas com concentrado aumentaram (P<0,05) a síntese de proteína microbiana e a eficiência da síntese e o balanço de nitrogênio sem diferença entre as fontes lipídicas (P>0,05). As dietas concentradas apresentaram maiores concentrações de nitrogênio uréico no soro e excreção urinária de uréia (P <0,05), mas não houve diferença entre as fontes lipídicas (P>0,05). A suplementação energética, com ou sem adição de lipídios, pode ser utilizada como estratégia para aumentar a síntese da proteína microbiana em bovinos alimentados com silagem de milho.

Analysis of the verification results of the laboratory ability to detect ammonia nitrogen in drinking water in the CDC in Hubei Province / 公共卫生与预防医学

Objective To understand the ability of the CDC to detect ammonia nitrogen in drinking water in Hubei Province. Methods The blind samples of two concentration levels were tested in the laboratories of the disease control institutions in the province, and the test results were evaluated by double-sample Z score. Results The satisfaction rate was 76.29% (74/97), the problem rate was 15.46% (15/97), and the dissatisfaction rate was 8.25% (8/97). Conclusion The detection ability of ammonia nitrogen in drinking water in laboratories of disease control institutions in Hubei Province is generally high，however，some laboratories need to be further improved.

Comparison of 18F-Flurpiridaz and 13N-NH3·H2O PET/CT myocardial perfusion imaging in animal experiments / 中华核医学与分子影像杂志

Objective@#To explore the biodistribution and quantitative value of 18F-Flurpiridaz in mini-swine, and compare with 13N-NH3·H2O.@*Methods@#Ten Bama mini-swine were divided into normal group and myocardial infarction group (n=5 in each group). Normal group was not treated and myocardial infarction group was modeled by thoracotomy and coronary artery ligation. Both groups were preceded by 13N-NH3·H2O imaging, followed by 18F-Flurpiridaz imaging (time interval >40 min). Injection dosage of 2 tracers was the same (185-370 MBq). 18F-Flurpiridaz whole-body PET/CT imaging was also performed in normal group. Biological distribution of 18F-Flurpiridaz was observed, and the ratio of radioactive uptake of 18F-Flurpiridaz between myocardium and adjacent tissues or organs was calculated. Image quality score and rest myocardial blood flow (rMBF) of 2 imaging tracers in normal group were measured and compared. MPI image quality score, cardiac function parameters such as summed rest score (SRS), myocardial infarction area percentage, total perfusion defect (TPD), and left ventricular ejection fraction (LVEF) of 2 imaging tracers were compared in myocardial infarction group. Data was analyzed by paired t test.@*Results@#In normal group, 18F-Flurpiridaz in the myocardium was clearly observed, with high radioactive uptake maintaining within 2 h postinjection. The radioactivity count ratios of left ventricular myocardium to cardiac pool, the lungs and liver were high (5.19-12.87, 4.17-50.51, 2.08-6.92). The quality of 18F-Flurpiridaz MPI images in both groups was excellent (10/10). The rMBF (ml·g-1·min-1) in different regions of left ventricle measured by 18F-Flurpiridaz and 13N-NH3·H2O imaging were not significantly different (left anterior descending: 0.98±0.06 vs 0.92±0.13; left circumflex: 0.98±0.05 vs 0.88±0.12; right coronary artery: 0.95±0.07 vs 0.88±0.15; left ventricle: 0.96±0.07 vs 0.90±0.13; t values: from -1.70 to -0.90, all P>0.05). There was no significant difference in SRS, myocardial infarction area percentage, TPD, rMBF or LVEF between 18F-Flurpiridaz and 13N-NH3·H2O (SRS: 10.6±4.1 vs 9.2±4.6; myocardial infarction area percentage: (15.2±9.0)% vs (12.6±6.6)%; TPD: (11.6±6.3)% vs (9.6±3.9)%; LVEF: (68.6±11.1)% vs (71.4±11.3)%; t values: -2.33-2.75, all P>0.05).@*Conclusions@#Comparing with 13N-NH3·H2O, 18F-Flurpiridaz has the advantages of good MPI image quality, accurate measurement of cardiac function parameters and quantitative potential of myocardial blood flow, which make it as a promising positron myocardial perfusion imaging agent.

Improvement program on pretreatment of acid decalcified tissue in hematoxylin-eosin staining / 华西口腔医学杂志

OBJECTIVE@#To explore the treatment conditions of acid decalcified specimens and improve the poor quality of sections and unclear structure of hematoxylin-eosin (HE) staining caused by the change in pH in tooth and hard tissue after acid decalcification.@*METHODS@#A total of 20 cases of oral pathological specimens that contain hard tissues were decalcified and treated with routine treatment, concentrated ammonia water immersion treatment, and saturated lithium carbonate solution immersion treatment. The quality and HE staining effects of hard tissue sections treated with different methods were compared.@*RESULTS@#Compared with routine treatment, lithium carbonate saturated solution treatment showed complete sections. Hematoxylin is strongly stained, the nucleus is clear, and the cytoplasm is bright.@*CONCLUSIONS@#Soaking acid decalcified specimens in lithium carbonate saturated solution before embedding in dehydration can neutralize the acidic environment of the tissue. The quality of sections and HE staining effect are improved and are suitable for the pretreatment of acid decalcified tissue samples of oral pathology.