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Papers by Antonio Vivi
Creatine deficiency syndrome due to mutations in X-linked SLC6A8 gene results in nonspecific inte... more Creatine deficiency syndrome due to mutations in X-linked SLC6A8 gene results in nonspecific intellectual disability (ID). Diagnosis cannot be established on clinical grounds and is often based on the assessment of brain creatine levels by magnetic resonance spectroscopy (MRS). Considering high costs of MRS and necessity of sedation, this technique cannot be used as a first level-screening test. Likewise, gene test analysis is time consuming and not easily accessible to all laboratories. In this article feasibility of urine analysis (creatine/creatinine (Cr/Crn) ratio) performed by nuclear magnetic resonance (NMR) as a first level-screening test is explored. Before running a systematic selection of cases a preliminary study for further molecular analysis is shown. NMR urine spectra (n 1,347) of male patients with an ID without a clinically recognizable syndrome were measured.
The Journal of Maternal-Fetal & Neonatal Medicine, 2014
To investigate changes in global metabolic profile between: 1 - breast milk and formula milk, 2 -... more To investigate changes in global metabolic profile between: 1 - breast milk and formula milk, 2 - breast milk from mothers delivering at different gestational age (GA) collected within one week from delivery, and then week by week until term equivalent age. Proton magnetic resonance spectroscopy (MRS) was used to analyze the water-soluble and lipid fractions extracted from 50 milk samples, 46 human milk at different GA, from 23 weeks of gestation until term equivalent age and four different formula milks. The formula milk for premature infants was the most similar to breast milk of preterm babies. Breast milk showed higher lactose concentrations than formula milk, that conversely presented higher galactose 1-phosphate and maltose concentrations. Mother's milk of very preterm babies (23-25 wks of GA) showed a different metabolic profile from preterm infants ≥29 wks of GA with a subsequent trend to similarity around the 30th week of post-natal age. Breast milk from preterm infants of 29-34 wks, collected up to 40 wks of post-natal age showed a temporal change over the first three weeks of lactation, approaching to zero with the achievement of term age. Metabolome is a promising tool to study human and artificial milk global metabolic profile.
Vaccines
Adjuvants have been used for decades to enhance the immune response to vaccines, in particular fo... more Adjuvants have been used for decades to enhance the immune response to vaccines, in particular for the subunit-based adjuvants. Physicochemical properties of the adjuvant-protein antigen complexes, such as size, morphology, protein structure and binding, influence the overall efficacy and safety of the vaccine. Here we show how to perform an accurate physicochemical characterization of the nanoaluminum–ovalbumin complex. Using a combination of existing techniques, we developed a multi-staged characterization strategy based on measurements of increased complexity. This characterization cascade has the advantage of being very flexible and easily adaptable to any adjuvant-protein antigen combinations. It will contribute to control the quality of antigen–adjuvant complexes and immunological outcomes, ultimately leading to improved vaccines.
Disease Markers
Background and Objective. Early identification of neonates at risk for brain injury is important ... more Background and Objective. Early identification of neonates at risk for brain injury is important to start appropriate intervention. Urinary metabolomics is a source of potential, noninvasive biomarkers of brain disease. We studied the urinary metabolic profile at 2 and 10 days in preterm neonates with normal/mild and moderate/severe MRI abnormalities at term equivalent age.Methods. Urine samples were collected at two and 10 days after birth in 30 extremely preterm infants and analyzed using proton magnetic resonance spectroscopy. A 3 T MRI was performed at term equivalent age, and images were scored for white matter (WM), cortical grey matter (cGM), deep GM, and cerebellar abnormalities. Infants were divided in two groups: normal/mild and moderately/severely abnormal MRI scores.Results. No significant clustering was seen between normal/mild and moderate/severe MRI scores for all regions at both time points. The ROC curves distinguished neonates at 2 and 10 days who later developed a...
Disease Markers, Oct 1, 2018
Background and Objective. Early identification of neonates at risk for brain injury is important ... more Background and Objective. Early identification of neonates at risk for brain injury is important to start appropriate intervention. Urinary metabolomics is a source of potential, noninvasive biomarkers of brain disease. We studied the urinary metabolic profile at 2 and 10 days in preterm neonates with normal/mild and moderate/severe MRI abnormalities at term equivalent age. Methods. Urine samples were collected at two and 10 days after birth in 30 extremely preterm infants and analyzed using proton magnetic resonance spectroscopy. A 3 T MRI was performed at term equivalent age, and images were scored for white matter (WM), cortical grey matter (cGM), deep GM, and cerebellar abnormalities. Infants were divided in two groups: normal/mild and moderately/severely abnormal MRI scores. Results. No significant clustering was seen between normal/mild and moderate/ severe MRI scores for all regions at both time points. The ROC curves distinguished neonates at 2 and 10 days who later developed a markedly less mature cGM score from the others (2 d: area under the curve (AUC) = 0.72, specificity (SP) = 65%, sensitivity (SE) = 75% and 10 d: AUC = 0.80, SP = 78%, SE = 80%) and a moderately to severely abnormal WM score (2 d: AUC = 0.71, specificity (SP) = 80%, sensitivity (SE) = 72% and 10 d: AUC = 0.69, SP = 64%, SE = 89%). Conclusions. Early urinary spectra of preterm infants were able to discriminate metabolic profiles in patients with moderately/severely abnormal cGM and WM scores at term equivalent age. Urine spectra are promising for early identification of neonates at risk of brain damage and allow understanding of the pathogenesis of altered brain development.
Journal of Magnetic Resonance Series A
Sodium ion has been traditionally conceived to be the main effector of changes in cellular volume... more Sodium ion has been traditionally conceived to be the main effector of changes in cellular volumes. Active extrusion of sodium by the Na/K pumps is considered to counterbalance the oncotic pressure of intracellular macromolecules. Development of NMR techniques for non-invasive measurement of cellular sodium and water contents has yielded new insights into cell volume regulation. The "indirect sodium-water coupling" hypothesis postulates that sodium correlates closely to changes in intracellular volume due to its extensive coupling with the transport of osmotically-active ions and molecules. Intracellular sodium and water contents change in parallel, however the coefficients that relate their trans-membranal fluxes in cardiac muscle vary widely. In limited cases, sodium-water uncoupling was observed upon attenuation of intracellular calcium and energy metabolism. This hypothesis offers an alternative mechanistic explanation that underlines the importance of additional volume-regulatory mechanisms bwsides sodium homeostasis.
Clinica Chimica Acta
In order to highlight differences in the metabolic profile of healthy (control) compared with asp... more In order to highlight differences in the metabolic profile of healthy (control) compared with asphyxiated newborns, by using untargeted metabolomics approach coupled with 1H-NMR spectroscopy, we evaluated the effects of asphyxia on newborn urine metabolites. Our results showed that lactate, glucose and TMAO, together with threonine plus 3-hydroxyisovalerate are the metabolites more characterizing the asphyxiated group; lower contribute to discrimination is related to other metabolites such as dimethylglycine, dimethylamine, creatine, succinate, formate, urea and aconitate. After 24-48h from the resuscitation preterm asphyctic neonates showed their recovery pattern that still can be differentiated by the controls. Copyright © 2015 Elsevier B.V. All rights reserved.
Journal of applied physiology (Bethesda, Md. : 1985), 1993
Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of heat-accl... more Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of heat-acclimated (AC) rats (at 34 degrees C for 1 mo) and their age-matched controls (C). Diastolic and systolic pressures, coronary flow, and the appearance of ischemic contracture (IC) were measured during progressive graded ischemia, total ischemia (TI), and reperfusion. ATP, phosphocreatine, and intracellular pH were measured during TI and reperfusion with the use of 31P-nuclear magnetic resonance spectroscopy. Systolic pressure was greater in AC hearts than in C hearts (P < 0.0001). During 50% of perfusion pressure 15 and 46% of AC and C hearts, respectively, showed IC (P < 0.001). During 25% of perfusion pressure 85% of the hearts in both groups developed IC. The onset of IC in AC hearts was delayed compared with in C hearts. On reperfusion 93 and 66% of AC and C hearts, respectively, resumed contraction. Recovery of diastolic pressure was 78 and 36% for the AC and C hearts, respective...
The American journal of physiology, 1995
Intracellular sodium accumulation, cellular swelling, and energy deficiency are ischemia-associat... more Intracellular sodium accumulation, cellular swelling, and energy deficiency are ischemia-associated processes that participate in the transition to irreversible ischemic injury. This study aims to determine the relationship among these parameters in intact rat hearts during global ischemia at 4 degrees C. High-energy phosphates were determined by 31P nuclear magnetic resonance, intracellular sodium accumulation was measured by 23Na spectroscopy with the shift reagent dysprosium triethyl tetraaminohexaacetic acid [Dy(TTHA)3(-)], and cell volumes were measured by 59Co and 1H spectroscopy with use of the extracellular marker Co(CN)3-(6). Intracellular sodium flux rates were 1.53 +/- 0.17, 0.17 +/- 0.05, and 0.30 +/- 0.06 mumol.g dry wt-1.min-1 at 0-1.5, 2-7, and 9-12 h, respectively. Sodium influx resulted in accumulation of the ion: 10% after 4 h, 16% after 10 h, and 29% after 12 h. Water followed sodium into the cells at two constant molar ratios (Na+/H2O): 3.80 +/- 0.15 x 10(-3) dur...
Helvetica chirurgica acta, 1992
The ideal level of hypothermia during myocardial preservation for cardiac transplantation remains... more The ideal level of hypothermia during myocardial preservation for cardiac transplantation remains unknown. Therefore 31P-NMR spectroscopy was applied to assess the effect of different preservation temperatures (15 degrees C in group 1, 4 degrees C in group 2) on time dependent changes of myocardial high energy phosphorous compounds during prolonged global ischemia (5 hours in group 1, 8 hours in group 2) and subsequent reperfusion of isolated rat hearts preserved with modified St. Thomas Hospital solution. ATP-depletion during ischemia was slower in group 2 leading to a significant difference in myocardial ATP-concentrations between both groups after 3 hours of ischemia. The drop of intracellular pH during ischemia was significantly less pronounced in hearts preserved at 4 degrees C compared to 15 degrees C. Postischemic recovery of both left ventricular (LV) peak systolic pressure and its +dP/dt max. was superior in group 2, although the ischemic time was 3 hours longer than in gro...
The Journal of thoracic and cardiovascular surgery, 1992
The effectiveness of the University of Wisconsin solution on extended myocardial preservation was... more The effectiveness of the University of Wisconsin solution on extended myocardial preservation was examined in this study using phosphorus 31-nuclear magnetic resonance spectroscopy. Isolated perfused rat hearts were arrested and stored in four preservation solutions: group 1, modified Krebs-Henseleit solution; group 2, modified St. Thomas' Hospital solution; group 3, oxygenated modified St. Thomas' Hospital solution containing 11 mmol/L glucose; and group 4, University of Wisconsin solution. The changes in myocardial high energy phosphate profiles and the intracellular pH values were measured during 12 hours of cold (4 degrees C) global ischemia and 90 minutes of normothermic reperfusion. Following ischemia, the hearts were assessed for hemodynamic recovery and myocardial water content. During ischemia, adenosine triphosphate depletion was observed in all groups; however, after 5 hours of ischemia, the adenosine triphosphate levels were significantly higher in group 3 compar...
PLoS Pathogens, 2014
The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic va... more The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the withinhost complexity of the pathogenesis of invasive disease.
Transplantation Journal, 2012
ABSTRACT Background. NMR spectroscopy–based metabolomics is a system approach used to investigate... more ABSTRACT Background. NMR spectroscopy–based metabolomics is a system approach used to investigate the metabolic profile of biological fluids with multivariate data analysis tools. The aim of this study was to examine the kidney graft recovery process noninvasively through the examinations of urine samples using 1H NMR spectroscopy combined with chemometric tools. Methods. Urine samples were treated as the source of metabolites reflecting the pathological and clinical conditions of patients with transplanted kidneys. We observed 15 subjects (9 males and 6 females) during the graft recovery process and initial days thereafter. The patients provided at least 9 samples each, applying advanced statistical methods of analysis: Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis PLS-DA). Results. The PCA model (for all subjects exp. var. PC1 13.96% and PC2 9.88%) allowed us to clearly designate 3 stages of recovery: initially the kidney is not working; in the second stage, it regains functions, and the third stage includes follow-up during hospitalization. PCA analysis of a single patient follows graft recovery based on biochemical (metabolites) information, assigning the appropriate recuperation stage. Conclusions. NMR spectroscopy together with chemometric analysis allow monitor- ing of kidney graft recovery to identify patients who are not progressing within the normal range.
NMR in Biomedicine, 2010
Our aim was to compare urinary ethylmalonic acid (EMA) levels in subjects who had no apparent cli... more Our aim was to compare urinary ethylmalonic acid (EMA) levels in subjects who had no apparent clinical reason to have increased levels of this substance but were suffering from non-specific CNS impairment, and healthy controls. Urinary EMA concentrations detected by 1 H-NMR spectroscopy were studied in 130 subjects with CNS impairment of unknown origin (with no definite diagnosis, no specific symptoms or signs, and normal common biochemical and metabolic screening results) and 130 age-and sex-matched healthy subjects. EMA levels exceeding two standard deviations (SD) above normal (i.e. 8.1 mmol/molCn) were found in a subgroup of CNS-impaired patients and healthy controls. EMA levels exceeding 2 SD above normal were fourfold prevalent in the urine of patients with non-specific CNS impairment compared to from the EMA levels in healthy controls. Moreover, we found that the level exceeding > 8.1 mmol/molCn (i.e. > R 2 SD) had sufficient discrimination accuracy in identifying subjects with non-specific CNS impairment; the level exceeding 12 mmol/molCn (i.e. > R 6 SD) reaches suitable accuracy (i.e. 100% specificity and 78.6% sensitivity). These observations are of importance, as we found that subtle increases in urinary EMA levels are frequent in patients with non-specific CNS impairment. The reasons for this association remain unknown.
Neoplasia, 2000
Hepatocyte growth factor / scatter factor (HGF / SF) is a paracrine growth factor which increases... more Hepatocyte growth factor / scatter factor (HGF / SF) is a paracrine growth factor which increases cellular motility and has also been implicated in tumor development and progression and in angiogenesis. Little is known about the metabolic alteration induced in cells following Met-HGF / SF signal transduction. The hypothesis that HGF / SF alters the energy metabolism of cancer cells was investigated in perfused DA3 murine mammary cancer cells by nuclear magnetic resonance (NMR) spectroscopy, oxygen and glucose consumption assays and confocal laser scanning microscopy (CLSM). 31 P NMR demonstrated that HGF / SF induced remarkable alterations in phospholipid metabolites, and enhanced the rate of glucose phosphorylation (P < .05). 13 C NMR measurements, using [ 13 C 1 ]-glucose-enriched medium, showed that HGS / SF reduced the steady state levels of glucose and elevated those of lactate (P < .05). In addition, HGF / SF treatment increased oxygen consumption from 0.58 0.02 to 0.71 0.03 mol / hour per milligram protein (P < .05). However, it decreased CO 2 levels, and attenuated pH decrease. The mechanisms of these unexpected effects were delineated by CLSM, using NAD (P) H fluorescence measurements, which showed that HGF / SF increased the oxidation of the mitochondrial NAD system. We propose that concomitant with induction of ruffling, HGF / SF enhances both the glycolytic and oxidative phosphorylation pathways of energy production. Neoplasia (2000) 2, 365 ± 377.
Magnetic Resonance in Medicine, 1995
The present study describes the cell volume dynamics in intact rat hearts, during ischemia and af... more The present study describes the cell volume dynamics in intact rat hearts, during ischemia and after reperfusion. Cell volumes were measured in isolated hearts by either 13C or 5aC0 NMR of mannitol or cobalticyanide, respectively, as extracellular markers and 'H NMR of water as the aqueous space marker. A constant volume chamber was built inside a 15-mm NMR tube; the contents of the chamber were measured with and without a heart. The intracellular volume of isolated rat hearts was estimated to be 2.45 f 0.13 ml/g dry weight. In the perfused heart, adenosine triphosphate (ATP) and phosphocreatine (PCr) concentrations were calculated to be 12.2 f 0.7 and 16.1 k 1.0 mM, respectively. Consecutive volume measurements showed cell swelling of 16% during 30 min of ischemia, which was reduced at reperfusion to 7%. After 30 min of reperfusion, ATP and PCr concentrations were 4.5 2 0.8 and 8.1 f 0.9 mM. It is concluded that: (1) cell swelling is an ischemic event, which is partially reversed by reperfusion; and (2) continuous measurement of cell volumes provides intracellular molar concentrations of metabolites, which are the physiologically significant parameters.
Creatine deficiency syndrome due to mutations in X-linked SLC6A8 gene results in nonspecific inte... more Creatine deficiency syndrome due to mutations in X-linked SLC6A8 gene results in nonspecific intellectual disability (ID). Diagnosis cannot be established on clinical grounds and is often based on the assessment of brain creatine levels by magnetic resonance spectroscopy (MRS). Considering high costs of MRS and necessity of sedation, this technique cannot be used as a first level-screening test. Likewise, gene test analysis is time consuming and not easily accessible to all laboratories. In this article feasibility of urine analysis (creatine/creatinine (Cr/Crn) ratio) performed by nuclear magnetic resonance (NMR) as a first level-screening test is explored. Before running a systematic selection of cases a preliminary study for further molecular analysis is shown. NMR urine spectra (n 1,347) of male patients with an ID without a clinically recognizable syndrome were measured.
The Journal of Maternal-Fetal & Neonatal Medicine, 2014
To investigate changes in global metabolic profile between: 1 - breast milk and formula milk, 2 -... more To investigate changes in global metabolic profile between: 1 - breast milk and formula milk, 2 - breast milk from mothers delivering at different gestational age (GA) collected within one week from delivery, and then week by week until term equivalent age. Proton magnetic resonance spectroscopy (MRS) was used to analyze the water-soluble and lipid fractions extracted from 50 milk samples, 46 human milk at different GA, from 23 weeks of gestation until term equivalent age and four different formula milks. The formula milk for premature infants was the most similar to breast milk of preterm babies. Breast milk showed higher lactose concentrations than formula milk, that conversely presented higher galactose 1-phosphate and maltose concentrations. Mother&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s milk of very preterm babies (23-25 wks of GA) showed a different metabolic profile from preterm infants ≥29 wks of GA with a subsequent trend to similarity around the 30th week of post-natal age. Breast milk from preterm infants of 29-34 wks, collected up to 40 wks of post-natal age showed a temporal change over the first three weeks of lactation, approaching to zero with the achievement of term age. Metabolome is a promising tool to study human and artificial milk global metabolic profile.
Vaccines
Adjuvants have been used for decades to enhance the immune response to vaccines, in particular fo... more Adjuvants have been used for decades to enhance the immune response to vaccines, in particular for the subunit-based adjuvants. Physicochemical properties of the adjuvant-protein antigen complexes, such as size, morphology, protein structure and binding, influence the overall efficacy and safety of the vaccine. Here we show how to perform an accurate physicochemical characterization of the nanoaluminum–ovalbumin complex. Using a combination of existing techniques, we developed a multi-staged characterization strategy based on measurements of increased complexity. This characterization cascade has the advantage of being very flexible and easily adaptable to any adjuvant-protein antigen combinations. It will contribute to control the quality of antigen–adjuvant complexes and immunological outcomes, ultimately leading to improved vaccines.
Disease Markers
Background and Objective. Early identification of neonates at risk for brain injury is important ... more Background and Objective. Early identification of neonates at risk for brain injury is important to start appropriate intervention. Urinary metabolomics is a source of potential, noninvasive biomarkers of brain disease. We studied the urinary metabolic profile at 2 and 10 days in preterm neonates with normal/mild and moderate/severe MRI abnormalities at term equivalent age.Methods. Urine samples were collected at two and 10 days after birth in 30 extremely preterm infants and analyzed using proton magnetic resonance spectroscopy. A 3 T MRI was performed at term equivalent age, and images were scored for white matter (WM), cortical grey matter (cGM), deep GM, and cerebellar abnormalities. Infants were divided in two groups: normal/mild and moderately/severely abnormal MRI scores.Results. No significant clustering was seen between normal/mild and moderate/severe MRI scores for all regions at both time points. The ROC curves distinguished neonates at 2 and 10 days who later developed a...
Disease Markers, Oct 1, 2018
Background and Objective. Early identification of neonates at risk for brain injury is important ... more Background and Objective. Early identification of neonates at risk for brain injury is important to start appropriate intervention. Urinary metabolomics is a source of potential, noninvasive biomarkers of brain disease. We studied the urinary metabolic profile at 2 and 10 days in preterm neonates with normal/mild and moderate/severe MRI abnormalities at term equivalent age. Methods. Urine samples were collected at two and 10 days after birth in 30 extremely preterm infants and analyzed using proton magnetic resonance spectroscopy. A 3 T MRI was performed at term equivalent age, and images were scored for white matter (WM), cortical grey matter (cGM), deep GM, and cerebellar abnormalities. Infants were divided in two groups: normal/mild and moderately/severely abnormal MRI scores. Results. No significant clustering was seen between normal/mild and moderate/ severe MRI scores for all regions at both time points. The ROC curves distinguished neonates at 2 and 10 days who later developed a markedly less mature cGM score from the others (2 d: area under the curve (AUC) = 0.72, specificity (SP) = 65%, sensitivity (SE) = 75% and 10 d: AUC = 0.80, SP = 78%, SE = 80%) and a moderately to severely abnormal WM score (2 d: AUC = 0.71, specificity (SP) = 80%, sensitivity (SE) = 72% and 10 d: AUC = 0.69, SP = 64%, SE = 89%). Conclusions. Early urinary spectra of preterm infants were able to discriminate metabolic profiles in patients with moderately/severely abnormal cGM and WM scores at term equivalent age. Urine spectra are promising for early identification of neonates at risk of brain damage and allow understanding of the pathogenesis of altered brain development.
Journal of Magnetic Resonance Series A
Sodium ion has been traditionally conceived to be the main effector of changes in cellular volume... more Sodium ion has been traditionally conceived to be the main effector of changes in cellular volumes. Active extrusion of sodium by the Na/K pumps is considered to counterbalance the oncotic pressure of intracellular macromolecules. Development of NMR techniques for non-invasive measurement of cellular sodium and water contents has yielded new insights into cell volume regulation. The "indirect sodium-water coupling" hypothesis postulates that sodium correlates closely to changes in intracellular volume due to its extensive coupling with the transport of osmotically-active ions and molecules. Intracellular sodium and water contents change in parallel, however the coefficients that relate their trans-membranal fluxes in cardiac muscle vary widely. In limited cases, sodium-water uncoupling was observed upon attenuation of intracellular calcium and energy metabolism. This hypothesis offers an alternative mechanistic explanation that underlines the importance of additional volume-regulatory mechanisms bwsides sodium homeostasis.
Clinica Chimica Acta
In order to highlight differences in the metabolic profile of healthy (control) compared with asp... more In order to highlight differences in the metabolic profile of healthy (control) compared with asphyxiated newborns, by using untargeted metabolomics approach coupled with 1H-NMR spectroscopy, we evaluated the effects of asphyxia on newborn urine metabolites. Our results showed that lactate, glucose and TMAO, together with threonine plus 3-hydroxyisovalerate are the metabolites more characterizing the asphyxiated group; lower contribute to discrimination is related to other metabolites such as dimethylglycine, dimethylamine, creatine, succinate, formate, urea and aconitate. After 24-48h from the resuscitation preterm asphyctic neonates showed their recovery pattern that still can be differentiated by the controls. Copyright © 2015 Elsevier B.V. All rights reserved.
Journal of applied physiology (Bethesda, Md. : 1985), 1993
Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of heat-accl... more Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of heat-acclimated (AC) rats (at 34 degrees C for 1 mo) and their age-matched controls (C). Diastolic and systolic pressures, coronary flow, and the appearance of ischemic contracture (IC) were measured during progressive graded ischemia, total ischemia (TI), and reperfusion. ATP, phosphocreatine, and intracellular pH were measured during TI and reperfusion with the use of 31P-nuclear magnetic resonance spectroscopy. Systolic pressure was greater in AC hearts than in C hearts (P < 0.0001). During 50% of perfusion pressure 15 and 46% of AC and C hearts, respectively, showed IC (P < 0.001). During 25% of perfusion pressure 85% of the hearts in both groups developed IC. The onset of IC in AC hearts was delayed compared with in C hearts. On reperfusion 93 and 66% of AC and C hearts, respectively, resumed contraction. Recovery of diastolic pressure was 78 and 36% for the AC and C hearts, respective...
The American journal of physiology, 1995
Intracellular sodium accumulation, cellular swelling, and energy deficiency are ischemia-associat... more Intracellular sodium accumulation, cellular swelling, and energy deficiency are ischemia-associated processes that participate in the transition to irreversible ischemic injury. This study aims to determine the relationship among these parameters in intact rat hearts during global ischemia at 4 degrees C. High-energy phosphates were determined by 31P nuclear magnetic resonance, intracellular sodium accumulation was measured by 23Na spectroscopy with the shift reagent dysprosium triethyl tetraaminohexaacetic acid [Dy(TTHA)3(-)], and cell volumes were measured by 59Co and 1H spectroscopy with use of the extracellular marker Co(CN)3-(6). Intracellular sodium flux rates were 1.53 +/- 0.17, 0.17 +/- 0.05, and 0.30 +/- 0.06 mumol.g dry wt-1.min-1 at 0-1.5, 2-7, and 9-12 h, respectively. Sodium influx resulted in accumulation of the ion: 10% after 4 h, 16% after 10 h, and 29% after 12 h. Water followed sodium into the cells at two constant molar ratios (Na+/H2O): 3.80 +/- 0.15 x 10(-3) dur...
Helvetica chirurgica acta, 1992
The ideal level of hypothermia during myocardial preservation for cardiac transplantation remains... more The ideal level of hypothermia during myocardial preservation for cardiac transplantation remains unknown. Therefore 31P-NMR spectroscopy was applied to assess the effect of different preservation temperatures (15 degrees C in group 1, 4 degrees C in group 2) on time dependent changes of myocardial high energy phosphorous compounds during prolonged global ischemia (5 hours in group 1, 8 hours in group 2) and subsequent reperfusion of isolated rat hearts preserved with modified St. Thomas Hospital solution. ATP-depletion during ischemia was slower in group 2 leading to a significant difference in myocardial ATP-concentrations between both groups after 3 hours of ischemia. The drop of intracellular pH during ischemia was significantly less pronounced in hearts preserved at 4 degrees C compared to 15 degrees C. Postischemic recovery of both left ventricular (LV) peak systolic pressure and its +dP/dt max. was superior in group 2, although the ischemic time was 3 hours longer than in gro...
The Journal of thoracic and cardiovascular surgery, 1992
The effectiveness of the University of Wisconsin solution on extended myocardial preservation was... more The effectiveness of the University of Wisconsin solution on extended myocardial preservation was examined in this study using phosphorus 31-nuclear magnetic resonance spectroscopy. Isolated perfused rat hearts were arrested and stored in four preservation solutions: group 1, modified Krebs-Henseleit solution; group 2, modified St. Thomas' Hospital solution; group 3, oxygenated modified St. Thomas' Hospital solution containing 11 mmol/L glucose; and group 4, University of Wisconsin solution. The changes in myocardial high energy phosphate profiles and the intracellular pH values were measured during 12 hours of cold (4 degrees C) global ischemia and 90 minutes of normothermic reperfusion. Following ischemia, the hearts were assessed for hemodynamic recovery and myocardial water content. During ischemia, adenosine triphosphate depletion was observed in all groups; however, after 5 hours of ischemia, the adenosine triphosphate levels were significantly higher in group 3 compar...
PLoS Pathogens, 2014
The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic va... more The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the withinhost complexity of the pathogenesis of invasive disease.
Transplantation Journal, 2012
ABSTRACT Background. NMR spectroscopy–based metabolomics is a system approach used to investigate... more ABSTRACT Background. NMR spectroscopy–based metabolomics is a system approach used to investigate the metabolic profile of biological fluids with multivariate data analysis tools. The aim of this study was to examine the kidney graft recovery process noninvasively through the examinations of urine samples using 1H NMR spectroscopy combined with chemometric tools. Methods. Urine samples were treated as the source of metabolites reflecting the pathological and clinical conditions of patients with transplanted kidneys. We observed 15 subjects (9 males and 6 females) during the graft recovery process and initial days thereafter. The patients provided at least 9 samples each, applying advanced statistical methods of analysis: Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis PLS-DA). Results. The PCA model (for all subjects exp. var. PC1 13.96% and PC2 9.88%) allowed us to clearly designate 3 stages of recovery: initially the kidney is not working; in the second stage, it regains functions, and the third stage includes follow-up during hospitalization. PCA analysis of a single patient follows graft recovery based on biochemical (metabolites) information, assigning the appropriate recuperation stage. Conclusions. NMR spectroscopy together with chemometric analysis allow monitor- ing of kidney graft recovery to identify patients who are not progressing within the normal range.
NMR in Biomedicine, 2010
Our aim was to compare urinary ethylmalonic acid (EMA) levels in subjects who had no apparent cli... more Our aim was to compare urinary ethylmalonic acid (EMA) levels in subjects who had no apparent clinical reason to have increased levels of this substance but were suffering from non-specific CNS impairment, and healthy controls. Urinary EMA concentrations detected by 1 H-NMR spectroscopy were studied in 130 subjects with CNS impairment of unknown origin (with no definite diagnosis, no specific symptoms or signs, and normal common biochemical and metabolic screening results) and 130 age-and sex-matched healthy subjects. EMA levels exceeding two standard deviations (SD) above normal (i.e. 8.1 mmol/molCn) were found in a subgroup of CNS-impaired patients and healthy controls. EMA levels exceeding 2 SD above normal were fourfold prevalent in the urine of patients with non-specific CNS impairment compared to from the EMA levels in healthy controls. Moreover, we found that the level exceeding > 8.1 mmol/molCn (i.e. > R 2 SD) had sufficient discrimination accuracy in identifying subjects with non-specific CNS impairment; the level exceeding 12 mmol/molCn (i.e. > R 6 SD) reaches suitable accuracy (i.e. 100% specificity and 78.6% sensitivity). These observations are of importance, as we found that subtle increases in urinary EMA levels are frequent in patients with non-specific CNS impairment. The reasons for this association remain unknown.
Neoplasia, 2000
Hepatocyte growth factor / scatter factor (HGF / SF) is a paracrine growth factor which increases... more Hepatocyte growth factor / scatter factor (HGF / SF) is a paracrine growth factor which increases cellular motility and has also been implicated in tumor development and progression and in angiogenesis. Little is known about the metabolic alteration induced in cells following Met-HGF / SF signal transduction. The hypothesis that HGF / SF alters the energy metabolism of cancer cells was investigated in perfused DA3 murine mammary cancer cells by nuclear magnetic resonance (NMR) spectroscopy, oxygen and glucose consumption assays and confocal laser scanning microscopy (CLSM). 31 P NMR demonstrated that HGF / SF induced remarkable alterations in phospholipid metabolites, and enhanced the rate of glucose phosphorylation (P < .05). 13 C NMR measurements, using [ 13 C 1 ]-glucose-enriched medium, showed that HGS / SF reduced the steady state levels of glucose and elevated those of lactate (P < .05). In addition, HGF / SF treatment increased oxygen consumption from 0.58 0.02 to 0.71 0.03 mol / hour per milligram protein (P < .05). However, it decreased CO 2 levels, and attenuated pH decrease. The mechanisms of these unexpected effects were delineated by CLSM, using NAD (P) H fluorescence measurements, which showed that HGF / SF increased the oxidation of the mitochondrial NAD system. We propose that concomitant with induction of ruffling, HGF / SF enhances both the glycolytic and oxidative phosphorylation pathways of energy production. Neoplasia (2000) 2, 365 ± 377.
Magnetic Resonance in Medicine, 1995
The present study describes the cell volume dynamics in intact rat hearts, during ischemia and af... more The present study describes the cell volume dynamics in intact rat hearts, during ischemia and after reperfusion. Cell volumes were measured in isolated hearts by either 13C or 5aC0 NMR of mannitol or cobalticyanide, respectively, as extracellular markers and 'H NMR of water as the aqueous space marker. A constant volume chamber was built inside a 15-mm NMR tube; the contents of the chamber were measured with and without a heart. The intracellular volume of isolated rat hearts was estimated to be 2.45 f 0.13 ml/g dry weight. In the perfused heart, adenosine triphosphate (ATP) and phosphocreatine (PCr) concentrations were calculated to be 12.2 f 0.7 and 16.1 k 1.0 mM, respectively. Consecutive volume measurements showed cell swelling of 16% during 30 min of ischemia, which was reduced at reperfusion to 7%. After 30 min of reperfusion, ATP and PCr concentrations were 4.5 2 0.8 and 8.1 f 0.9 mM. It is concluded that: (1) cell swelling is an ischemic event, which is partially reversed by reperfusion; and (2) continuous measurement of cell volumes provides intracellular molar concentrations of metabolites, which are the physiologically significant parameters.