Characteristics of amino acid metabolism in myeloid-derived suppressor cells in septic mice / 北京大学学报(医学版)

OBJECTIVE@#To explore the amino acid metabolomics characteristics of myeloid-derived suppressor cells (MDSCs) in mice with sepsis induced by the cecal ligation and puncture (CLP).@*METHODS@#The sepsis mouse model was prepared by CLP, and the mice were randomly divided into a sham operation group (sham group, n = 10) and a CLP model group (n = 10). On the 7th day after the operation, 5 mice were randomly selected from the surviving mice in each group, and the bone marrow MDSCs of the mice were isolated. Bone marrow MDSCs were separated to measure the oxygen consumption rate (OCR) by using Agilent Seahorse XF technology and to detect the contents of intracellular amino acids and oligopeptides through ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) technology. Different metabolites and potential biomarkers were analyzed by univariate statistical analysis and multivariate statistical analysis. The major metabolic pathways were enriched using the small molecular pathway database (SMPDB).@*RESULTS@#The proportion of MDSCs in the bone marrow of CLP group mice (75.53% ± 6.02%) was significantly greater than that of the sham group (43.15%± 7.42%, t = 7.582, P < 0.001), and the basal respiratory rate [(50.03±1.20) pmol/min], maximum respiration rate [(78.07±2.57) pmol/min] and adenosine triphosphate (ATP) production [(25.30±1.21) pmol/min] of MDSCs in the bone marrow of CLP group mice were significantly greater than the basal respiration rate [(34.53±0.96) pmol/min, (t = 17.41, P < 0.001)], maximum respiration rate [(42.57±1.87) pmol/min, (t = 19.33, P < 0.001)], and ATP production [(12.63±0.96) pmol/min, (t = 14.18, P < 0.001)] of sham group. Leucine, threonine, glycine, etc. were potential biomarkers of septic MDSCs (all P < 0.05). The increased amino acids were mainly enriched in metabolic pathways, such as malate-aspartate shuttle, ammonia recovery, alanine metabolism, glutathione metabolism, phenylalanine and tyrosine metabolism, urea cycle, glycine and serine metabolism, β-alanine metabolism, glutamate metabolism, arginine and proline metabolism.@*CONCLUSION@#The enhanced mitochondrial oxidative phosphorylation, malate-aspartate shuttle and alanine metabolism in MDSCs of CLP mice may provide raw materials for mitochondrial aerobic respiration, thereby promoting the immunosuppressive function of MDSCs. Blocking the above metabolic pathways may reduce the risk of secondary infection in sepsis and improve the prognosis.

Influence of glyphosate in planktonic and biofilm growth of Pseudomonas aeruginosa

This study evaluated the impact of different concentrations of glyphosate (Rondup®) on planktonic and biofilm growth of P. aeruginosa. Aerobic and anaerobic cultures of P. aeruginosa ATCC®15442 inoculated in MHB + glyphosate (0.845 ppm, 1.690 ppm, 8.45 ppm, 16.90 ppm, 84.50 ppm, 169 ppm, 845 ppm, and 1690 ppm) and cultured in normoxia and anoxia, following their OD560nm every hour for 24 h. Biofilms of adapted cells were formed in the presence of glyphosate (0.845 to 1690 ppm) in normoxia and anoxia for 36 h. Glyphosate at concentrations higher than 84.5 ppm reduces the cell density of planktonic aerobic cultures (p < 0.05). However, these same concentrations favor the planktonic anaerobic growth (p < 0.05). On the other hand, the herbicide favors a slight growth of biofilms in a concentration-dependent manner up to 84.5 ppm (p > 0.05), and more pronounced over 169 ppm. Anaerobic biofilms have their growth more readily favored (p < 0.05), regardless of concentration. In a concentration-dependent manner, glyphosate interferes with the growth ability of P. aeruginosa ATCC®15442.

Transurethral resection of prostate: a comparison of standard monopolar versus bipolar saline resection

INTRODUCTION: Transurethral resection syndrome is an uncommon but potentially life threatening complication. Various irrigating solutions have been used, normal saline being the most physiological. The recent availability of bipolar cautery has permitted the use of normal saline irrigation. MATERIAL AND METHODS: In a randomized prospective study, we compared the safety and efficacy of bipolar cautery (using 0.9 percent normal saline irrigation) versus conventional monopolar cautery (using 1.5 percent glycine irrigation). Pre and postoperative hemoglobin (Hb) and hematocrit values were compared. Hemodynamics and arterial oxygen saturation were monitored throughout the study. Safety end points were changes in serum electrolytes, osmolarity and Hb/PCV (packed cell volume). Efficacy parameters were the International Prostate Symptom Score (IPSS) and Qmax (maximum flow rate in mL/sec) values. RESULTS: Mean preoperative prostate size on ultrasound was 60 ± 20cc. Mean resected weight was 17.6 ± 10.8 g (glycine) and 18.66 ± 12.1 g (saline). Mean resection time was 56.76 ± 14.51 min (glycine) and 55.1 ± 13.3 min (saline). The monopolar glycine group showed a greater decline in serum sodium and osmolarity (4.12 meq/L and 5.14 mosmol/L) compared to the bipolar saline group (1.25 meq/L and 0.43 mosmol/L). However, this was not considered statistically significant. The monopolar glycine group showed a statistically significant decline in Hb and PCV (0.97 gm percent, 2.83, p < 0.005) as compared to the bipolar saline group (0.55 gm percent and 1.62, p < 0.05). Patient follow- up (1,3,6 and 12 months postoperatively) demonstrated an improvement in IPSS and Qmax in both the groups. CONCLUSION: We concluded that bipolar transurethral resection of prostate is clinically comparable to monopolar transurethral resection of prostate with an improved safety profile. However, larger number of patients with longer follow up is essential.

Neonatal nonketotic hyperglycinemia.

Nonketotic hyperglycinemia has variable phenotypic expressions and a poor prognosis. We report a case of severe neonatal nonketotic hyperglycinemia, who started convulsing immediately after birth. His glycine index was 0.38 and he did not respond to treatment with sodium benzoate and dextromethorphan. Hypotonia, transient hyperammonemia and metabolic acidosis were associated findings.

Photobiodegradation of pyridine by Rhodopseudomonas palustris JA1.

A purple non-sulfur bacterium isolated from dairy effluent was identified as Rps. palustris JA1. This organism was able to grow on pyridine as sole source of carbon in a light dependent anaerobic process with a doubling time of 30 h. Intermediates of pyridine photobiodegradation were identified as glycine and malonate, produced in stoichiometric molar ratios with simultaneous utilization, yielding biomass.

Effects of endosulfan on intestinal functions in protein-malnourished rats.

In rats fed 18% protein diet, administration of endosulfan (2mg/kg body weight daily for 7 days) significantly decreased the brush border sialic acid and increased the hexoses contents. The intestinal uptake of glucose was increased while that of glycine and calcium was reduced. Brush border enzymes and lipids were not affected. However, in protein malnourished rats (fed 8% protein) exposed to endosulfan, brush border sucrase and peptidase activities were enhanced, while alkaline phosphatase activity was decreased compared to untreated malnourished animals. Membrane sialic acid content was low while fucose and cholesterol levels were augmented in endosulfan fed malnourished animals. The uptake of glucose and glycine was elevated under these conditions. These results Suggest that the nutritional status of the animals has an important bearing on thc susceptibility of intestinal tissue to endosulfan toxicity in rats.

Soybean trypsin inhibitor confers protection against rotavirus infection in infant mice.

OBJECTIVE: To study the effects of soybean trypsin inhibitor (TI) on glycine uptake, glutathione (GSH) levels and morphological changes of intestine in rotavirus (RV) infected infant mice. METHODS: A total of 144 infant mice (7/8 days old) were divided in 3 groups (i.e. control, RV and RV + inhibitor). Infant mice were orally inoculated with the EB strain of RV and Trypsin protease inhibitor (TI) and 8 animals each were sacrificed on days 0,1,3,5,7 and 10 post infection (p.i). Glycine uptake (in vitro), GSH levels and histological changes were assessed in the jejunum, ileum and colon. RESULTS: Glycine uptake and GSH levels were significantly reduced on days 3 and 5 p.i in jejunum and ileum of RV inoculated animals, compared to the controls. Glycine uptake and GSH levels were maintained as in controls in the RV + TI inoculated animals on days 3 and 5 p.i in jejunum and colon but not in ileum where lesser values were recorded. Histology showed vacuolar degeneration in ileum towards the apical portion whereas normal morphology was observed in jejunum, similar to controls. No histological changes were observed in colon in any of the groups. Electron microscopic study confirmed the viral infection. CONCLUSION: Administration of Trypsin protease inhibitor along with RV reverted the effects of RV infection on amino acid uptake and GSH levels completely in the jejunum and partially in the ileum.

Diagnóstico tardio da hiperglicinemia näo-cetótica: relato de dois casos neonatais / Late diagnosis of nonketotic hyperglycinemia: report of two neonatal cases

A hiperglicemia näo-cetótica é uma doença genética, de herança autossômica recessiva, que causa distúrbios graves em recém-nascidos, podem levar à morte. Níveis aumentados de glicina no cérebro produzem lesäo neurológica irreversível. O diagnóstico clínico é confirmado por cromatografia líquida (HPLC), comparando-se os níveis de glicina em plasma e líquido cefalorraquidiano - uma relaçäo LCR/plasma maior do que 0,09 fecha o diagnóstico. O presente estudo relata dois casos de hiperglicemia neonatal com quadro clínico e evoluçäo neurológica semelhantes. Nos dois casos, os sintomas começaram nas primeiras 48 horas de vida, e näo havia antecedentes familiares, pré-natais ou perinatais. Os dois recém-nascidos apresentaram boas condiçöes ao nascimento. Além disso, em ambos os casos, o daignóstico laboratorial (HPLC) foi bastante tardio: as amostras de sangue total e liquor foram colhidas 55§ e no 17§ dia, respectivamente. As concentraçöes de glicina em LCR e plasma, e a relaçäo LCR/plasma, foram (em mg/dl), para as crianças número 1 e número 2, repectivamente: 2,8 e 3,3 (R=0,85); 2,4 e 8 (r=0,3). Muito embora os recém-nascidos tenham permanecido em unidade de terapia intensiva e suporte ventilatório e tenham sido medicados com benzoato de sódio e diazepam, o diagnóstico tardio da hiperglicinemia acarretou lesöes neurológicas graves e irreversíveis nas duas crianças. No entanto, a importância do diagnóstico laboratorial para o aconselhamento genético dos dois casais é inquestionável

Metabolism of diglycine and triglycine by non-filtering kidneys

We have studied the metabolism of diglycine and triglycine in the isolated non-filtering rat kidney. Kidneys from adult male Wistar Kyoto rats weighing 250-350 g were perfused with Krebs-Henseleit solution containing either 1 mM diglycine or triglycine. The analysis of the peptide residues and their components was performed using an amino acid microanalyzer utilizing ion exchange chromatography. Diglycine was degraded to a final concentration of 0.09 mM after 120 min (91 per cent); this degradation occurred predominantly during the first hour, with a 56 per cent reduction of the initial concentration. The metabolism of triglycine occurred similarly, with a final concentration of 0.18 mM (82 per cent); during the first hour there was a 67 per cent reduction of the initial concentration of the tripeptide. Both peptides produced glycine in increasing concentrations, but there was a slightly lower recovery of glycine, suggesting its utilization by the kidney as fuel. The hydrolysis of triglycine also produced diglycine, which was also hydrolyzed to glycine. The results of the present study show the existence of functional endothelial or contraluminal membrane peptidases which may be important during parenteral nutrition.

Characterization and regulation of glycine transport in Fusarium oxysporum var. lini

Glycine was transported in Fusarium oxysporum cells, grow on glycine as the sole source of carbon and nitrogen, by a facilitated diffusion transport system with a half-saturation constant(Ks) of 11 mM and a maximum velocity (Vmax) of 1.2 mM (g dry weight)-1 h-1 at pH 5.0 and 26 degrees Celsius. Under conditions of nitrogen starvation, the same system was present together with a high-affinity one(Ks) of about 47 muM and Vmax of about 60 muM (g dry weight)(-1) h-1)). The low-affinity system was more specific than the high-affinity system. Cells grown on gelatine showed the same behavior. In cells grown on glucose-gelatine medium, the low-affinity system was poorly expressed even after carbon and nitrogen starvation. Moreover, addition of glucose to cells grown on glycine and resuspended in mineral medium caused an increase of the glycine transport probably due to a boost in protein synthesis. This stimulation did not affect the Ks of the low-affinity system. These results demonstrate that, as is the case for other eukaryotic systems, F.oxysporum glycine transport is under control of nitrogen sources but its regulation by carbon sources appears to be more complex.

Inhibición de la glicosilación no enzimática de la hemoglobina en la diabetes mellitus / Inhibition of non-enzymatic glycosilation of hemoglobin in diabetes mellitus

Se estudió el efecto inhibidor del aminoácido glicina sobre la glicosilación no enzimática de la hemoglobina en la diabetes experimental de ratas Wistar con estreptozotocina. La hemoglobina glicosilada de las ratas diabéticas fue de 4.2 ñ 0.38 por ciento y la de las diabéticas que tomaron glicina al 1 por ciento en el agua de bebida ad libitum fue de 2.90 ñ 0.37 por ciento (p = 0.00005). Un grupo de 30 personas diabéticas tipo II y 8 de tipo I tomaron glicina disuelta en agua: 20 gramos diarios (4 tomas de 5 g cada 6 horas) durante tiempos variables: de 3 hasta 56 meses. La hemoglobina glicosilada promedio de los diabéticos antes de tomar la clicina fue de 12.8 ñ 3.3 por ciento y después fue de 8.3 ñ 2.2 por ciento con un valor de p= 7 x 10-12 (prueba de rangos señalados de Wilcoxon)

Neurotransmisores y esquizofrenia / Neurotransmitters and schizophrenia

En la patologia esquizofrénica, los modelos bioquímicos explicativos mas comunes son: El de la Dopamina y el de la Fenciclidina. El neurotransmisor Dopamina actúa sobre los diversos receptores específicos, y la Fenciclidina sobre los llamados receptores de aminoácidos excitatorios. Otra hipótesis, como la de la Glicina o la de las Poliaminas, también tienen que ver con la acción sobre receptores de aminoacidos excitatorios. Esta revisión estudia algunos eventos neuroquímicos y neuropatológicos relacionados con los modelos mencionados. Conclusion: La esquizofrenia no puede ser explicada por un modelo simple, y mas bien es el resultado de una compleja interacción de disfunciones en los sistemas de neurotransmisión.

Non-ketotic hyperglycinemia- A typical case detected in a screening program for inborn errors of metabolism

Apresentamos um caso típico de hiperglicinemia näo-cetótica neonatal (McKusick 23830) detectado em um programa de triagem para erros inatos do metabolismo realizado no Rio de Janeiro e confirmado por análises que caracterizam os sintomas específicos desse distúrbio. Dados clínicos e características bioquímicas säo descritos e comparados com casos previamente relatados

Síntesis y control del MAG3 99mTc. Estudios comparativos con el hipurán 131I en seres humanos / Syntesis and control of Tc99m MAG3: comparative study with 131I hippuran in humans

La benzoilmercaptoacetiltriglicina (MAG,) se sintetizó de acuerdo con el método de A.R.Fritzberg y colaboradores. Se comprobó su pureza por punto de fusión, composición centesimal, cromatografía líquida de alta presión y resonancia magnética nuclear. Se realizaron estudios farmacológicos, esterilidad, apirogenicidad, toxicidad aguda y distribución biológica en animales. El producto (MAG,) marcado con tecnecio 99m, según la técnica de J.R.Coveney y M.S.Roblins, se controló por cromatografía en papel. Posteriormente, se inyectó en seres humanos (2,5-3 ,Ci) en normales y con patología renal (39 casos totales) realizándose el estudio comparativo con hipurán

Kainic acid induced epileptogenesis in developing normal & undernourished rats--a computerised EEG analysis.

Experimental epilepsy was induced in developing normal, undernourished and subsequently rehabilitated rats by locally injecting graded doses of Kainic acid (KA) in the right frontal cortex. Frequency and power spectral analysis of EEG was carried out to assess the progressive changes in EEG during KA-epileptogenesis. Undernourished animals were highly susceptible to seizure discharge. They exhibited generalized tonic-clonic discharge and had episodes of clinical seizures even after temporary neuronal recovery. Increase in power of delta, theta and decrease in alpha power was observed in the compressed spectral array (CSA) of undernourished animals. Delayed neuronal recovery with reduced background EEG and marked electrosilence in response to intra-rectal sodium valproate was observed in undernourished animals. Rehabilitated animals exhibited partial recovery which was related to the body weight gain. Spike frequency, spike amplitude and neuronal recovery time were not significantly differet between normal and undernourished animals at lower doses of KA (7.5-60 ng) whereas at higher doses (120-500 ng) marked differences were observed in these parameters. In KA treated undernourished rats 3H-glycine incorporation was significantly higher than normal in the hippocampus and spinal cord and lower in the cerebellum.