Identification and characterization of a novel 2R, 3R-Butanediol dehydrogenase from Bacillus sp. DL01

BACKGROUND: 2R,3R-butanediol dehydrogenase (R-BDH) and other BDHs contribute to metabolism of 3R/3S-Acetoin (3R/3S-AC) and 2,3-butanediol (2,3-BD), which are important bulk chemicals used in different industries. R-BDH is responsible for oxidizing the hydroxyl group at their (R) configuration. Bacillus species is a promising producer of 3R/3S-AC and 2,3-BD. In this study, R-bdh gene encoding R-BDH from Bacillus sp. DL01 was isolated, expressed and identified. RESULTS: R-BDH exerted reducing activities towards Diacetyl (DA) and 3R/3S-AC using NADH, and oxidizing activities towards 2R,3R-BD and Meso-BD using NAD+ , while no activity was detected with 2S,3S-BD. The R-BDH showed its activity at a wide range of temperature (25 C to 65 C) and pH (5.0­8.0). The R-BDH activity was increased significantly by Cd2+ when DA, 3R/3S-AC, and Meso-BD were used as substrates, while Fe2+ enhanced the activity remarkably at 2R,3R-BD oxidation. Kinetic parameters of the R-BDH from Bacillus sp. DL01 showed the lowest Km, the highest Vmax, and the highest Kcat towards the racemic 3R/3S-AC substrate, also displayed low Km towards 2R,3R-BD and Meso-BD when compared with other reported R-BDHs. CONCLUSIONS: The R-BDH from Bacillus sp. DL01 was characterized as a novel R-BDH with high enantioselectivity for R-configuration. It considered NAD+ and Zn2+ dependant enzyme, with a significant affinity towards 3R/3S-AC, 2R,3R-BD, and Meso-BD substrates. Thus, R-BDH is providing an approach to regulate the production of 3R/3S-AC or 2,3-BD from Bacillus sp. DL01.

Research Progress on Abused Drugs Metabolic in vivo / 法医学杂志

Under the catalysis of a variety of metabolic enzymes in vivo, such as UDP-glucuronyl transferases, cytochrome P450, carboxylesterase, sulfotransferase, butyrylcholinesterase, catechol-O-methyl transferase and 6-morphine dehydrogenase, the drugs perform glucuronidation, hydrolysis, oxidation, sulfonation and other reactions, then translate into active or inactive metabolites, which are excreted through urination, bile or the other pathways at last. Different drugs own their different metabolic pathways. This paper introduces the studies about the metabolism of drugs in human and animal in recent years, such as morphine-like drugs, amphetamine, ketamine, cannabis and cocaine, and reviews the research progress about the sites of metabolism, metabolic enzymes, metabolites and physiological activity of those drugs metabolic in vivo.

Risk factors for transient dysfunction of gas exchange after cardiac surgery / Fatores de risco para disfunção transitória da troca gasosa após a cirurgia cardíaca

Objective: A retrospective cohort study was preformed aiming to verify the presence of transient dysfunction of gas exchange in the postoperative period of cardiac surgery and determine if this disorder is linked to cardiorespiratory events. Methods: We included 942 consecutive patients undergoing cardiac surgery and cardiac procedures who were referred to the Intensive Care Unit between June 2007 and November 2011. Results: Fifteen patients had acute respiratory distress syndrome (2%), 199 (27.75%) had mild transient dysfunction of gas exchange, 402 (56.1%) had moderate transient dysfunction of gas exchange, and 39 (5.4%) had severe transient dysfunction of gas exchange. Hypertension and cardiogenic shock were associated with the emergence of moderate transient dysfunction of gas exchange postoperatively (P=0.02 and P=0.019, respectively) and were risk factors for this dysfunction (P=0.0023 and P=0.0017, respectively). Diabetes mellitus was also a risk factor for transient dysfunction of gas exchange (P=0.03). Pneumonia was present in 8.9% of cases and correlated with the presence of moderate transient dysfunction of gas exchange (P=0.001). Severe transient dysfunction of gas exchange was associated with patients who had renal replacement therapy (P=0.0005), hemotherapy (P=0.0001), enteral nutrition (P=0.0012), or cardiac arrhythmia (P=0.0451). Conclusion: Preoperative hypertension and cardiogenic shock were associated with the occurrence of postoperative transient dysfunction of gas exchange. The preoperative risk factors included hypertension, cardiogenic shock, and diabetes. Postoperatively, pneumonia, ventilator-associated pneumonia, renal replacement therapy, hemotherapy, and cardiac arrhythmia were associated with the appearance of some degree of transient dysfunction of gas exchange, which was a risk factor for reintubation, pneumonia, ventilator-associated pneumonia, and renal replacement therapy in the postoperative period ...

Objetivo: Estudo de coorte retrospectivo com objetivo de verificar a presença de disfunção transitória da troca gasosa no pós-operatório de cirurgia cardíaca e determinar se esse transtorno está relacionado a eventos cardiorrespiratórios. Métodos: Foram incluídos 942 pacientes consecutivos submetidos à cirurgia cardíaca e procedimentos cardíacos, encaminhados para a Unidade de Terapia Intensiva, entre junho de 2007 e novembro de 2011. Resultados: A síndrome do desconforto respiratório agudo foi observada em 15 (2%) pacientes, 199 (27,75%) pacientes apresentaram disfunção transitória da troca gasosa leve, disfunção transitória da troca gasosa moderada foi observada em 402 (56,1%) pacientes e disfunção transitória da troca gasosa grave em 39 (5,4%). A presença de hipertensão arterial sistêmica e choque cardiogênico foi associada ao surgimento de disfunção transitória da troca gasosa moderada no período pós-operatório (P=0,02 e P=0,019, respectivamente) e foram considerados fatores de risco para essa disfunção (P=0,0023 e P=0,0017, respectivamente). A presença de diabetes mellitus também foi considerada um fator de risco para disfunção transitória da troca gasosa (P=0,03). Houve correlação entre a presença de pneumonia e a presença de disfunção transitória da troca gasosa moderada em 8,9% dos casos (P=0,001). A presença de disfunção transitória da troca gasosa grave foi associada a pacientes que necessitaram de hemodiálise (P=0,0005), hemoterapia (P=0,0001), nutrição enteral (P=0,0012), ou arritmia cardíaca (P=0,0451). Conclusão: A presença de hipertensão arterial sistêmica pré-operatória e choque cardiogênico foi associada à ocorrência de disfunção transitória da troca gasosa pós-operatória. Os fatores de risco pré-operatórios foram hipertensão arterial sistêmica, choque cardiogênico e diabetes. No pós-operatório, pneumonia, pneumonia associada à ventilação, hemodiálise, hemoterapia e arritmia cardíaca foram associadas com certo grau de ...

"El hecho de que sean más mujeres, no garantiza nada": feminización y experiencias de las mujeres en la ginecobstetricia en México / "The fact that there are more women doesn't guarantee anything": The feminization of obstetrics and gynecology and the experiences of female medical professionals in Mexico

En el marco de la creciente feminización de la profesión médica en México, el artículo indaga sobre las características de este proceso para el caso de la ginecobstetricia. Considerando la feminización como un proceso de cambio, que se analiza cuantitativa y cualitativamente, el artículo se detiene en especial en las experiencias de las mujeres ginecobstetras, experiencias que se dan en el seno de una especialidad que, desde sus orígenes, funcionó como un dispositivo de control del cuerpo de las mujeres. Basado en una investigación etnográfica, el artículo combina fuentes estadísticas, de archivo y de observación de campo. El material que surge de las entrevistas muestra las experiencias y tensiones que viven las ginecobstetras en este contexto.

In the framework of an increasing feminization of the medical profession in Mexico, this article explores the characteristics of this process in the obstetrics and gynecology specialty. Understanding feminization as a process of change to be analyzed both quantitatively and qualitatively, the article focuses special attention on the experiences of female obstetrician-gynecologists within a medical specialty that has since its origins functioned as a mechanism of control over women's bodies. Based on ethnographic research, the article combines statistical and archival sources and field observation. The interviews reveal the experiences and tensions women obstetrician-gynecologists encounter in this context.

Phenylpropanoid enzymes, phenolic polymers and metabolites as chemical defenses to infection of Pratylenchus coffeae in roots of resistant and susceptible bananas (Musa spp.).

Activity differences of the first (phenylalanine ammonia lyase, PAL) and the last (cinnamyl alcohol dehydrogenase, CAD) enzymes of phenylpropanoid pathway in the roots of resistant (Yangambi Km5 and Anaikomban) and susceptible (Nendran and Robusta) banana cultivars caused by root lesion nematode, Pratylenchus coffeae, were investigated. Also, the accumulation of phenolics and deposition of lignin polymers in cell walls in relation to resistance of the banana cultivars to the nematode were analyzed. Compared to the susceptible cultivars, the resistant cultivars had constitutively significantly higher PAL activity and total soluble and cell wall-bound phenolics than in susceptible cultivars. The resistant cultivars responded strongly to the infection of the nematode by induction of several-time higher PAL and CAD enzymes activities, soluble and wall-bound phenolics and enrichment of lignin polymers in cell wall and these biochemical parameters reached maximum at 7th day postinoculation. In addition, profiles of phenolic acid metabolites in roots of Yangambi Km5 and Nendran were analyzed by HPLC to ascertain the underlying biochemical mechanism of bananas resistance to the nematode. Identification and quantification of soluble and cell wall-bound phenolic acids showed six metabolites and only quantitative, no qualitative, differences occurred between the resistant and susceptible cvs. and between constitutive and induced contents. A very prominent increase of p-coumaric, ferulic and sinapic acids, which are precursors of monolignols of lignin, in resistant cv. was found. These constitutive and induced biochemical alterations are definitely the chemical defenses of resistant cvs. to the nematode infection.

The proapoptotic activity of C-terminal domain of apoptosis-inducing factor (AIF) is separated from its N-terminal

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that mediates both NADH-oxidizing and caspase-independent apoptosis. Further, the proapoptotic activity of AIF is located in the C-terminus of AIF, although the precise minimum sequence responsible for apoptosis induction remains to be investigated. In the present study, we generated two truncated AIFs, AIFΔ1-480-FLAG, which is a FLAG-tagged C-terminal peptide comprising amino acids from 481 to 613, and AIF360-480 containing amino acids from 360 to 480 of AIF. We used confocal microscopy to demonstrate that both the truncated proteins are expressed and located in the cytoplasm of transfected cells. AIFΔ1-480 but not AIF360-480 induces apoptosis in transfected cells. We also found that the expression of AIFΔ1-480 could initiate the release of cytochrome c from the mitochondria. The suppression of caspase-9 via siRNA blocked the proapoptotic activity of AIFΔ1-480. Therefore, AIFΔ 1-480 is sufficient for inducing caspase-9-dependent apoptotic signaling, probably by promoting the release of cytochrome c. At last, we generated a chimeric immuno-AIFΔ 1-480 protein, which comprised an HER2 antibody, a Pseudomonas exotoxin A translocation domain and AIFΔ 1-480. Human Jurkat cells transfected with the immuno-AIFΔl-480 gene could express and secrete the chimeric protein, which selectively recognize and kill HER2-overexpressing tumor cells. Our study demonstrates the feasibility of the immuno-AIFΔl-480 gene as a novel approach to treating HER2-overexpressing cancers.

Effect of Aerva lanata on calcium oxalate urolithiasis in rats.

Calcium oxalate (CaOx) stone was induced in rats using 0.75% of ethylene glycol in drinking water for 28 days. Ethylene glycol treated rats showed significant increase in the activities of oxalate synthesizing enzymes such as glycolic acid oxidase (GAO) in liver and lactate dehydrogenase (LDH) in liver and kidney. CaOx crystal deposition, as indicated by increased excretion of stone-forming constituents in urine, such as calcium, oxalate, uric acid, phosphorus and protein and decreased concentration of inhibitors, such as citrate and magnesium was observed in ethylene glycol induced urolithic rats. Histopathological studies also confirmed the deposition of CaOx crystals. Administration of Aerva lanata aqueous suspension (2g/kg body wt/dose/day for 28 days) to CaOx urolithic rats had reduced the oxalate synthesizing enzymes, diminished the markers of crystal deposition in the kidney. The results of the present study confirmed that A. lanata can be used as an curative agent for urolithiasis.

Extreme nuclear disproportion and constancy of enzyme activity in a heterokaryon of Neurospora crassa.

Heterokaryons of Neurospora crassa were generated by transformation of multinucleate conidia of a histidine-3 auxotroph with his-3(+) plasmid. In one of the transformants, propagated on a medium with histidine supplementation, a gradual but drastic reduction occurred in the proportion of prototrophic nuclei that contained an ectopically integrated his-3(+) allele. This response was specific to histidine. The reduction in prototrophic nuclei was confirmed by several criteria: inoculum size test, hyphal tip analysis, genomic Southern analysis, and by visual change in colour of the transformant incorporating genetic colour markers. Construction and analyses of three-component heterokaryons revealed that the change in nuclear ratio resulted from interaction of auxotrophic nucleus with prototrophic nucleus that contained an ectopically integrated his-3(+) gene, but not with prototrophic nucleus that contained his-3(+) gene at the normal chromosomal location. The growth rate of heterokaryons and the activity of histidinol dehydrogenase - the protein encoded by the his-3(+) gene - remained unchanged despite prototrophic nuclei becoming very scarce. The results suggest that not all nuclei in the coenocytic fungal mycelium may be active simultaneously, the rare active nuclei being sufficient to confer the wild-type phenotype.

Sjögren-Larsson syndrome: an appraised of the litterature and presentation of two cases

A Síndrome de Sjögren-Larsson é uma doença autossômica recessiva rara com distribuiçäo universal. Consiste em ictiose, displegia espástica e retardo mental causado por um defeito enzimático na oxidaçäo do álcool-graxo. Nós relatamos dois casos e fazemos uma revisäo da literatura respectiva. As duas crianças tinham atividade deficiente da NAD oxidorredutase. Foram estudados os lípides de membrana das células plasmáticas e eritrócitos. Bons resultados foram obtidos em um dos pacientes quando submetido a dieta na infância precoce o que se correlacionou com diminuiçäo do álcool-graxo no plasma. Entretanto näo obtivemos melhora clínica no outro paciente cujo tratamento teve início tardio.Terapia com etretinato foi necessária para controlar os sintomas cutâneos neste segundo paciente.

Biochemical studies on Mycobacterium leprae.

Very little information is available on the basic biology of Mycobacterium leprae. It is not known why the organism fails to grow in bacteriological media or in cell cultures and why it has an unusual predilection for certain tissues in the human host where cells derived from the neural crest occur (e.g. skin, peripheral nerves adrenal medulla). Biochemical studies have revealed that M. Leprae contains an unusual form of the enzyme diphenoloxidase which has not been detected in other mycobacteria. The presence of a specific glutamic acid decarboxylase in the organism has been demonstrated. Although a few enzymes of glycolysis and tricarboxylic acid cycle have been investigated, nothing characteristic of the bacterium has been discovered, and how M. leprae derives energy for its survival and proliferation still remains obscure.