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1.
Phys Rev E ; 109(1-1): 014230, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38366434

ABSTRACT

Recent evidence shows that heteroclinic bifurcations in magnetic islands may be caused by the amplitude variation of resonant magnetic perturbations in tokamaks. To investigate the onset of these bifurcations, we consider a large aspect ratio tokamak with an ergodic limiter composed of two pairs of rings that create external primary perturbations with two sets of wave numbers. An individual pair produces hyperbolic and elliptic periodic points, and its associated islands, that are consistent with the Poincaré-Birkhoff fixed-point theorem. However, for two pairs producing external perturbations resonant on the same rational surface, we show that different configurations of isochronous island chains may appear on phase space according to the amplitude of the electric currents in each pair of the ergodic limiter. When one of the electric currents increases, isochronous bifurcations take place and new islands are created with the same winding number as the preceding islands. We present examples of bifurcation sequences displaying (a) direct transitions from the island chain configuration generated by one of the pairs to the configuration produced by the other pair, and (b) transitions with intermediate configurations produced by the limiter pairs coupling. Furthermore, we identify shearless bifurcations inside some isochronous islands, originating nonmonotonic local winding number profiles with associated shearless invariant curves.

3.
Theriogenology ; 215: 144-150, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38070213

ABSTRACT

This experiment evaluated pregnancy losses from day 30 of gestation to calving in Bos indicus females, and evaluated if serum haptoglobin concentrations during early gestation impacts subsequent pregnancy losses. A total of 4926 Nelore females were used, being 1802 nulliparous heifers inseminated as yearlings (precocious heifers), 1356 nulliparous heifers inseminated at 24 months of age (conventional heifers), 887 suckling primiparous cows, and 881 suckling multiparous cows. Cows were assigned to an ovulation synchronization + fixed-time artificial insemination (FTAI) protocol from day -11 to 0 of the experiment. Pregnancy status was verified using transrectal ultrasonography on days 30 and 60 after FTAI, via transrectal palpation on day 150 after FTAI, and according to calf birth. Blood samples were collected from all animals diagnosed pregnant on day 30 after FTAI, and analyzed for serum concentrations of haptoglobin and pregnancy associated glycoproteins (PAG). Pregnancy loss was greater (P < 0.01) from day 60-150 of gestation (10.2 %) compared with day 30-60 of gestation (6.0 %) and with day 150 of gestation to calving (7.4 %), and differed (P = 0.04) between these latter two periods. Pregnancy loss from day 30-60 of gestation did not differ (P = 0.26) among parities, whereas total pregnancy losses (day 30 to calving) were greater (P < 0.01) in precocious (28.4 %) and conventional (27.1 %) heifers compared with primiparous (16.4 %) and multiparous (13.0 %) cows. Serum PAG concentrations on day 30 after FTAI were less (P ≤ 0.03) in cows that lost the pregnancy (5.63 ng/mL) from day 30-60 of gestation, as well as those that lost the pregnancy from day 30 to calving (8.59 ng/mL) compared with cohorts that maintained the pregnancy (9.39 and 9.32 ng/mL, respectively). No differences in serum PAG concentrations on day 30 after FTAI were noted (P ≥ 0.23) according to pregnancy losses from day 60 to calving. Serum haptoglobin concentration on day 30 after FTAI also did not differ (P ≥ 0.48) between cows that maintained or lost the pregnancy. This experiment provides novel information about pregnancy losses after day 30 of gestation in B. indicus cattle, with most losses occurring as fetal mortality and not affected by systemic inflammation during early gestation. Pregnancy losses were nearly doubled in precocious and conventional heifers compared with parous cows, demonstrating the relevance of this reproductive failure to B. indicus replacement heifers.


Subject(s)
Cattle Diseases , Haptoglobins , Pregnancy , Cattle , Animals , Female , Estrus Synchronization/methods , Abortion, Veterinary , Glycoproteins , Parity , Insemination, Artificial/veterinary , Insemination, Artificial/methods , Progesterone
4.
Eur Radiol ; 33(3): 1698-1706, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36271920

ABSTRACT

OBJECTIVES: To evaluate the feasibility of Doppler-ultrasound (DUS)-gated 4D flow MRI of the fetal great thoracic vessels at 3T in a clinical setting. METHODS: Sixteen consecutive fetuses (range 30+4-38+5 weeks) with (n = 11) and without (n = 5) cardiovascular anomalies underwent 4D flow MRI of the great thoracic vessels at 3T. Direct fetal cardiac gating was obtained using a MR-compatible DUS device. 4D flow MRI-based visualisation and quantification of four target regions (ascending aorta (AAo), descending aorta (DAo), main pulmonary artery (MPA), and ductus arteriosus (DA)) were performed using dedicated software. RESULTS: Fetal 4D flow MRI of the great thoracic vessels was successful in 12/16 fetuses (75%) by adopting clinical 4D flow MR protocols in combination with direct fetal cardiac DUS-gating. Four datasets were excluded due to artefacts by fetal movement or maternal breathing. 4D flow MRI-derived time-velocity curves revealed typical arterial blood flow patterns in the aorta. 4D flow quantification was achieved for the pre-defined target regions. Average velocity and flow volume were 21.1 ± 5.2 cm/s and 6.0 ± 3.1 mL/s in the AAo, 24.3 ± 6.7 cm/s and 8.4 ± 3.7 mL/s in the DAo, 21.9 ± 6.4 cm/s and 7.8 ± 4.2 mL/s in the MPA, and 23.4 ± 4.7 cm/s and 5.9 ± 3.6 mL/s in the DA, respectively. CONCLUSIONS: Combination of DUS-gating of the fetal heart and 4D flow MRI allows comprehensive visualisation and quantification of haemodynamics in the fetal great thoracic vessels. DUS-gated fetal 4D flow MRI may provide a new diagnostic approach for prenatal assessment of blood flow haemodynamics. KEY POINTS: • Fetal cardiac Doppler-ultrasound (DUS) gating and 4D flow MRI can be successfully combined. • DUS-gated fetal 4D flow MRI allowed visualisation and evaluation of streamline directionality, illustration of blood flow variations, and pulsatile arterial waveforms in the target vessels. • 4D flow MRI-based visualisation and quantification of the fetal great thoracic vessels were successful and flow metrics agreed with echocardiographic reference values.


Subject(s)
Fetal Heart , Magnetic Resonance Imaging , Pregnancy , Female , Humans , Feasibility Studies , Gestational Age , Fetal Heart/diagnostic imaging , Fetal Heart/physiology , Pulmonary Artery/diagnostic imaging , Blood Flow Velocity/physiology , Aorta, Thoracic
5.
Chaos ; 31(8): 083104, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34470246

ABSTRACT

We analyze nonlinear aspects of the self-consistent wave-particle interaction using Hamiltonian dynamics in the single wave model, where the wave is modified due to the particle dynamics. This interaction plays an important role in the emergence of plasma instabilities and turbulence. The simplest case, where one particle (N=1) is coupled with one wave (M=1), is completely integrable, and the nonlinear effects reduce to the wave potential pulsating while the particle either remains trapped or circulates forever. On increasing the number of particles ( N=2, M=1), integrability is lost and chaos develops. Our analyses identify the two standard ways for chaos to appear and grow (the homoclinic tangle born from a separatrix, and the resonance overlap near an elliptic fixed point). Moreover, a strong form of chaos occurs when the energy is high enough for the wave amplitude to vanish occasionally.

6.
Ultrasound Obstet Gynecol ; 55(1): 47-49, 2020 01.
Article in English | MEDLINE | ID: mdl-31486133

ABSTRACT

OBJECTIVE: To report the outcome of monochorionic twins with twin reversed arterial perfusion (TRAP) sequence following interstitial laser therapy in the first trimester. METHODS: This was a retrospective cohort study of all consecutive cases of TRAP that underwent interstitial laser therapy at ≤ 14 + 3 weeks' gestation between January 2014 and April 2016. Interstitial laser treatment was performed under ultrasound guidance using a 400-nm Nd:YAG laser fiber. Hospital records were reviewed to ascertain perinatal survival and morbidity. RESULTS: Twelve monochorionic twin pregnancies underwent interstitial laser treatment of the umbilical artery of the acardiac fetus, at a median gestational age of 13 + 5 (interquartile range (IQR), 13 + 4 to 14 + 0) weeks. In all cases, one treatment was sufficient to achieve complete interruption of the perfusion of the acardiac twin. There were no procedure-related complications during or within 48 h after the procedure. In one (8.3%) case, intrauterine death of the pump twin occurred 2 weeks after the intervention. All other cases (91.7%) resulted in a live birth at a median gestational age of 39 + 6 (IQR, 37 + 1 to 41 + 2) weeks and with a median birth weight of 3370 (IQR, 2980-3480) g. No neonatal mortality or serious morbidity occurred. CONCLUSIONS: Our results support the use of interstitial laser therapy in the first trimester of pregnancy complicated by TRAP sequence, showing a live birth rate of 92%. The results of a randomized controlled trial, evaluating early vs late intervention in pregnancy with TRAP sequence, are awaited. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.


Subject(s)
Fetofetal Transfusion/surgery , Pregnancy, Twin , Prenatal Care , Adult , Cohort Studies , Female , Fetofetal Transfusion/diagnostic imaging , Fetofetal Transfusion/mortality , Germany , Gestational Age , Humans , Laser Therapy , Pregnancy , Pregnancy Outcome , Pregnancy Trimester, First , Retrospective Studies , Survival Analysis , Ultrasonography, Interventional , Ultrasonography, Prenatal
7.
Eur Radiol ; 29(8): 4169-4176, 2019 Aug.
Article in English | MEDLINE | ID: mdl-30617486

ABSTRACT

OBJECTIVES: To investigate the feasibility of fetal phase-contrast (PC)-MR angiography of the descending aorta (AoD) using an MR-compatible Doppler ultrasound sensor (DUS) for fetal cardiac gating and to compare velocimetry with Doppler ultrasound measurements. METHODS: In this prospective study, 2D PC-MR angiography was performed in 12 human fetuses (mean gestational age 32.8 weeks) using an MR-compatible DUS for gating of the fetal heart at 1.5 T. Peak flow velocities in the fetal AoD were compared with Doppler ultrasound measurements performed on the same day. Reproducibility of PC-MR measurements was tested by repeated PC-MR in five fetuses. RESULTS: Dynamic PC-MR angiography in the AoD was successfully performed in all fetuses using the DUS, with an average fetal heart rate of 140 bpm (range 129-163). Time-velocity curves revealed typical arterial blood flow patterns. PC-MR mean flow velocity and mean flux were 21.2 cm/s (range 8.6-36.8) and 8.4 ml/s (range 3.2-14.6), respectively. A positive association between PC-MR mean flux and stroke volume with gestational age was obtained (r = 0.66, p = 0.02 and r = 0.63, p = 0.03). PC-MR and Doppler ultrasound peak velocities revealed a highly significant correlation (r = 0.8, p < 0.002). Peak velocities were lower for PC-MR with 69.1 cm/s (range 39-125) compared with 96.7 cm/s (range 60-142) for Doppler ultrasound (p < 0.001). Reproducibility of PC-MR was high (p > 0.05). CONCLUSION: The MR-compatible DUS for fetal cardiac gating allows for PC-MR angiography in the fetal AoD. Comparison with Doppler ultrasound revealed a highly significant correlation of peak velocities with underestimation of PC-MR velocities. This new technique for direct fetal cardiac gating indicates the potential of PC-MR angiography for assessing fetal hemodynamics. KEY POINTS: • The developed MR-compatible Doppler ultrasound sensor allows direct fetal cardiac gating and can be used for prenatal dynamic cardiovascular MRI. • The MR-compatible Doppler ultrasound sensor was successfully applied to perform intrauterine phase-contrast MR angiography of the fetal aorta, which revealed a highly significant correlation with Doppler ultrasound measurements. • As fetal flow hemodynamics is an important parameter in the diagnosis and management of fetal pathologies, fetal phase-contrast MR angiography may offer an alternative imaging method in addition to Doppler ultrasound and develop as a second line tool in the evaluation of fetal flow hemodynamics.


Subject(s)
Blood Flow Velocity/physiology , Fetus/physiology , Magnetic Resonance Angiography/methods , Prenatal Diagnosis/methods , Adult , Arteries/embryology , Arteries/physiology , Female , Fetal Blood/physiology , Gestational Age , Humans , Magnetic Resonance Angiography/standards , Maternal Age , Microscopy, Phase-Contrast/methods , Pregnancy , Prenatal Diagnosis/standards , Prospective Studies , Reproducibility of Results , Ultrasonography, Doppler/methods , Ultrasonography, Prenatal/methods
8.
Ultrasound Obstet Gynecol ; 53(6): 794-797, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30207009

ABSTRACT

OBJECTIVES: To evaluate the relationship between the fetal intertwin difference in middle cerebral artery peak systolic velocity (MCA-PSV) and intertwin difference in hemoglobin (Hb) concentration at birth in monochorionic diamniotic (MCDA) twin pregnancies in order to assess its potential role in the prediction of twin anemia-polycythemia sequence (TAPS). METHODS: This was a retrospective cohort study of MCDA twin pregnancies delivered between January 2012 and January 2018. All pregnancies with measurements of MCA-PSV within 7 days prior to delivery and in which neonatal Hb concentration was available were included. The correlation between fetal intertwin difference in MCA-PSV, expressed in multiples of the median (MoM), and neonatal intertwin difference in Hb concentration was investigated. Receiver-operating characteristics (ROC) curve analysis was used to assess the performance of fetal intertwin difference in MCA-PSV for predicting intertwin difference in Hb > 90th centile at birth. RESULTS: A total of 154 out of 256 MC twin pregnancies fulfilled the inclusion criteria. Fetal intertwin difference in MCA-PSV MoM correlated positively with neonatal intertwin difference in Hb concentration (r = 0.79; P < 0.001). The 90th centile for intertwin difference in Hb was 7.25 g/dL. There were 15 (9.7%) cases with a Hb difference ≥ 7.25 g/dL at birth. ROC curve analysis showed a high accuracy of fetal intertwin MCA-PSV MoM difference for the prediction of neonatal intertwin Hb difference ≥ 7.25 g/dL at birth (area under the ROC curve, 0.976 (95% CI, 0.935-0.993); P = 0.012). The optimal cut-off for intertwin MCA-PSV MoM difference was 0.373, with a sensitivity of 93.3% (95% CI, 68.1-99.8%) and a specificity of 95.7% (95% CI, 90.8-98.4%). The positive predictive value was 70% (95% CI, 45.7-88.1%) and the negative predictive value was 99.3% (95% CI, 95.9-100%). CONCLUSION: Our findings show that fetal intertwin MCA-PSV MoM difference is a good predictor of neonatal intertwin Hb concentration difference > 90th centile and potentially of TAPS. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Anemia/physiopathology , Polycythemia/physiopathology , Twins, Monozygotic , Ultrasonography, Prenatal , Adolescent , Adult , Anemia/congenital , Anemia/diagnosis , Anemia/diagnostic imaging , Blood Flow Velocity , Cohort Studies , Female , Humans , Infant, Newborn , Male , Middle Aged , Polycythemia/congenital , Polycythemia/diagnosis , Polycythemia/diagnostic imaging , Pregnancy , Pulsatile Flow , Retrospective Studies , Sensitivity and Specificity , Systole , Young Adult
9.
Ultrasound Obstet Gynecol ; 53(5): 669-675, 2019 May.
Article in English | MEDLINE | ID: mdl-30381848

ABSTRACT

OBJECTIVES: To investigate the diagnostic performance of dynamic fetal cardiac magnetic resonance imaging (MRI), using a MR-compatible Doppler ultrasound (DUS) device for fetal cardiac gating, in differentiating fetuses with congenital heart disease from those with a normal heart, and to compare the technique with fetal echocardiography. METHODS: This was a prospective study of eight fetuses with a normal heart and four with congenital heart disease (CHD), at a median of 34 (range, 28-36) weeks' gestation. Dynamic fetal cardiac MRI was performed using a DUS device for direct cardiac gating. The four-chamber view was evaluated according to qualitative findings. Measurements of the length of the left and right ventricles, diameter of the tricuspid and mitral valves, myocardial wall thickness, transverse cardiac diameter and left ventricular planimetry were performed. Fetal echocardiography and postnatal diagnoses were considered the reference standards. RESULTS: Direct cardiac gating allowed continuous triggering of the fetal heart, showing high temporal and spatial resolution. Both fetal cardiac MRI and echocardiography in the four-chamber view detected pathological findings in three of the 12 fetuses. Qualitative evaluation revealed overall consistency between echocardiography and MRI. On both echocardiography and MRI, quantitative measurements revealed significant differences between fetuses with a normal heart and those with CHD with respect to the length of the right (P < 0.01 for both) and left (P < 0.01 for both) ventricles and transverse cardiac diameter (P < 0.05 and P < 0.01, respectively). Tricuspid valve diameter on cardiac MRI was found to be significantly different in healthy fetuses from in those with CHD (P < 0.05). CONCLUSIONS: For the first time, this study has shown that dynamic fetal cardiac MRI in the four-chamber view, using external cardiac gating, allows evaluation of cardiac anatomy and diagnosis of congenital heart disease in agreement with fetal echocardiography. Dynamic fetal cardiac MRI may be useful as a second-line investigation if conditions for fetal echocardiography are unfavorable. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.


Subject(s)
Echocardiography, Doppler/statistics & numerical data , Fetal Heart/diagnostic imaging , Heart Defects, Congenital/diagnostic imaging , Magnetic Resonance Angiography/statistics & numerical data , Ultrasonography, Prenatal/statistics & numerical data , Adult , Echocardiography, Doppler/methods , Female , Gestational Age , Heart Defects, Congenital/embryology , Heart Function Tests/methods , Heart Function Tests/statistics & numerical data , Humans , Magnetic Resonance Angiography/methods , Pregnancy , Prospective Studies , Reproducibility of Results , Ultrasonography, Prenatal/methods , Young Adult
11.
J Physiol Pharmacol ; 69(3)2018 Jun.
Article in English | MEDLINE | ID: mdl-30342429

ABSTRACT

Currently, literature has accumulated great knowledge over the effect of exercise on the neurotrophin named brain derived neurotrophic factor (BDNF) and its role in neuronal plasticity. However, there is no enough discussion about how the exercise is related to enrichment of BDNF in specific metabolic properties. This review provides the current evidences regarding aerobic metabolism relation to BDNF concentrations in healthy individuals. A PICOS strategy was applied considering the mesh terms for: P - healthy subjects; I - physical exercise; C - aerobic metabolism demands; O - BDNF concentrations; S - before and after aerobic exercise; on PubMed, Scopus and Medline databases. Studies presenting at least one session the exercise with reports of BDNF analysis before and after were included. Reviews, letters, case-reports, articles not written in English, non- published or involving non-healthy populations were excluded. Compiling results, it was possible to observe a close interaction between different aerobic energy demands from the exercise models and the responses of BDNF, suggesting thus that increases in BDNF concentrations are associated to the amount of aerobic energy required by exercise in a dose-dependent manner. Moreover, the dynamics of BDNF synthesis and reuptake resemble the functioning of the metabolic systems of aerobic energy generation, with which they share a co-transcriptional factor dependence.


Subject(s)
Brain-Derived Neurotrophic Factor/physiology , Neuronal Plasticity/physiology , Aerobiosis , Brain/physiology , Exercise/physiology , Humans
12.
J Med Microbiol ; 67(8): 1042-1046, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29939129

ABSTRACT

Multidrug-resistant bacteria pose a major threat to effective antibiotics and alternatives to fight multidrug-resistant pathogens are needed. We synthetized molybdenum oxide (MoO3) nanoparticles (NP) and determined their antibacterial activity against 39 isolates: (i) eight Staphylococcus aureus, including representatives of methicillin-resistant S. aureus epidemic clones; (ii) six enterococci, including vancomycin-resistant isolates; and (iii) 25 Gram-negative isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae), including extended spectrum beta-lactamases and carbapenemases producers. All isolates showed a MoO3 NP MIC of 700-800 mg l-1. MoO3 NP produced a clear inhibition zone for S. aureus and all Gram-negative isolates at concentrations ≥25 mg ml-1 and ≥50 mg ml-1 for enterococci. When the NP solutions were adjusted to pH ~7, the biocidal activity was completely abolished. MoO3 NP create an acidic pH and show a universal antimicrobial activity against susceptible and resistant isolates belonging to the most relevant bacterial species responsible for hospital-acquired infections.


Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Molybdenum/pharmacology , Nanoparticles , Oxides/pharmacology , Anti-Bacterial Agents/chemistry , Bacterial Infections/microbiology , Gram-Negative Bacteria/isolation & purification , Gram-Positive Bacteria/isolation & purification , Humans , Hydrogen-Ion Concentration , Microbial Sensitivity Tests , Molybdenum/chemistry , Oxides/chemistry
14.
J Hosp Infect ; 100(3): 344-349, 2018 Nov.
Article in English | MEDLINE | ID: mdl-29807064

ABSTRACT

BACKGROUND: The prevalence of nosocomial meticillin-resistant Staphylococcus aureus (MRSA) was previously estimated as 23% in a paediatric hospital in Luanda, Angola and 18% in a general hospital in São Tomé and Príncipe. AIM: To evaluate the prevalence of S. aureus/MRSA colonization among hospitalized children and their parents at two hospitals in Angola and São Tomé and Príncipe. METHODS: In 2017, 127 hospitalized children and 129 of their parents had nasal swabs for S. aureus/MRSA carriage in the two countries. The isolates were tested for the presence of the mecA and Panton-Valentine leukocidin (PVL) genes, and characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multi-locus sequence typing and SCCmec typing. FINDINGS: Twenty of 127 children (15.7%) and 13 of 129 parents (10.1%) were MRSA nasal carriers. Three lineages comprised 88% of the MRSA isolates: (i) PFGE A-ST5-SCCmec IVa (N=15; 45%), associated with spa type t105, recovered in Angola alone; (ii) PFGE N-ST8-IV/V (N=7; 21%), associated with spa types t008/t121, recovered in São Tomé and Príncipe alone; and (iii) PFGE B-ST88-IVa (N=7; 21%), associated with spa types t325/t786, present in both countries. Fifteen child/guardian pairs were colonized with identical MRSA (N=8) or meticillin-susceptible S. aureus (N=7) strains. PVL was detected in 25% of isolates, including two MRSA (ST30-V and ST8-IVa). CONCLUSION: Hospitalized children and their parents are important reservoirs of MRSA. Infection control measures should focus on parents in order to minimize the spread of MRSA to the community.


Subject(s)
Carrier State/epidemiology , Inpatients , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Parents , Staphylococcal Infections/epidemiology , Angola/epidemiology , Carrier State/microbiology , Child , Child, Preschool , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Hospitals , Humans , Male , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/genetics , Multilocus Sequence Typing , Prevalence , Sao Tome and Principe/epidemiology , Staphylococcal Infections/microbiology , Virulence Factors/genetics
15.
Eur J Clin Microbiol Infect Dis ; 36(12): 2379-2383, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28825186

ABSTRACT

Multidrug-resistant (MR) Gram-negative (GN) pathogens pose a major and growing threat for healthcare systems, as therapy of infections is often limited due to the lack of available systemic antibiotics. Well-tolerated antiseptics, such as octenidine dihydrochloride (OCT), may be a very useful tool in infection control to reduce the dissemination of MRGN. This study aimed to investigate the bactericidal activity of OCT against international epidemic clones of MRGN. A set of five different species (Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Acinetobacter baumannii, and Pseudomonas aeruginosa) was studied to prove OCT efficacy without organic load, under "clean conditions" (0.3 g/L albumin) and under "dirty conditions" (3 g/L albumin + 3 mL/L defibrinated sheep blood), according to an official test norm (EN13727). We used five clonally unrelated isolates per species, including a susceptible wild-type strain, and four MRGN isolates, corresponding to either the 3MRGN or 4MRGN definition of multidrug resistance. A contact time of 1 min was fully effective for all isolates by using different OCT concentrations (0.01% and 0.05%), with a bacterial reduction factor of >5 log10 systematically observed. Growth kinetics were determined with two different wild-type strains (A. baumannii and K. pneumoniae), proving a time-dependent efficacy of OCT. These results highlight that OCT may be extremely useful to eradicate emerging highly resistant Gram-negative pathogens associated with nosocomial infections.


Subject(s)
Anti-Infective Agents/pharmacology , Drug Resistance, Multiple, Bacterial/drug effects , Gram-Negative Bacteria/drug effects , Gram-Negative Bacterial Infections/microbiology , Pyridines/pharmacology , Anti-Bacterial Agents/pharmacology , Dose-Response Relationship, Drug , Gram-Negative Bacteria/genetics , Humans , Imines , Microbial Sensitivity Tests
16.
Transplant Proc ; 49(4): 813-816, 2017 May.
Article in English | MEDLINE | ID: mdl-28457401

ABSTRACT

BACKGROUND: Aldosterone is involved in the process of renal allograft fibrosis, clinically manifest by proteinuria and allograft dysfunction, with increased risk for cardiovascular death. The treatment with aldosterone antagonists appears to be effective in controlling proteinuria, with a protective effect on progression of renal fibrosis. METHODS: This retrospective, cohort study included kidney transplant recipients from January 1993 to June 2015. Inclusion criteria were persistent proteinuria >0.5 g/d, longer than 6 months, and spironolactone therapy. RESULTS: One hundred forty transplant recipients fulfilled the inclusion criteria and were divided into 3 groups, according to proteinuria levels at the beginning of spironolactone therapy: low (<1 g/24 h), intermediate (1-3 g/24 h), and nephrotic (>3 g/24 h). Groups were comparable in demographic data, with a higher incidence of living related donors in the nephrotic group. In patients with proteinuria ≥1 g/d, we observed a significant reduction in proteinuria after 6 months of therapy that persisted over time. Blood pressure and glomerular filtration rate persisted stable over time. Adverse events were not severe to withdrawal therapy. CONCLUSIONS: Spironolactone can be a safe alternative to control post-transplant proteinuria, especially in patients with mild to moderate allograft dysfunction with proteinuria ≥1 g/day.


Subject(s)
Diuretics/therapeutic use , Kidney Transplantation/adverse effects , Proteinuria/drug therapy , Spironolactone/therapeutic use , Adult , Female , Humans , Male , Middle Aged , Proteinuria/etiology , Retrospective Studies
17.
Eur J Clin Microbiol Infect Dis ; 36(7): 1243-1252, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28160148

ABSTRACT

High rates of trimethoprim/sulfamethoxazole (SXT) resistance, a combination of two antifolate antibiotics trimethoprim (TMP) and sulfamethoxazole (SMZ), have been reported among Staphylococcus aureus isolates in Portuguese-speaking African countries. Our study aimed to evaluate the occurrence of TMP resistance markers in major SXTR methicillin-resistant S. aureus (MRSA) clones from these countries. We accessed also different fitness traits that could explain the success of these isolates over the Brazilian MRSA (the most successful SXTR MRSA clone worldwide but never identified in these countries). Minimum inhibitory concentrations for SXT, TMP and SMZ were determined, and genes encoding TMP resistance (dfrG, dfrA, dfrK and dfrB) were searched. Representatives of the Brazilian clone and of the major MRSA African clones were evaluated for their fitness by individual growth curves, competition assays, survival under desiccation, autolytic activity, resistance to oxidative stress, and also growth at high osmolarity and in acid and alkaline environments. Although all African isolates showed high-level resistance to TMP, the majority presented hetero-resistance to SXT. TMP resistance was linked to the presence of dfrG (78%), dfrA (19%) or both (3%) genes. Compared to the Brazilian clone, the African isolates showed higher growth rates and autolytic activity, and better survival to desiccation and alkaline conditions. Since isolates exhibiting SXT hetero-resistance are frequent in Africa, the implementation of standardized guidelines to detect this phenomenon is of major interest. The predominant MRSA clones in Portuguese-speaking African countries likely possess significant advantages over other clones, such as the Brazilian MRSA, that may explain their epidemiological success.


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Methicillin-Resistant Staphylococcus aureus/drug effects , Staphylococcal Infections/microbiology , Trimethoprim, Sulfamethoxazole Drug Combination/pharmacology , Africa , Genes, Bacterial , Genetic Fitness , Humans , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Microbial Sensitivity Tests , Prevalence
19.
J Nutr Health Aging ; 21(2): 180-186, 2017.
Article in English | MEDLINE | ID: mdl-28112773

ABSTRACT

BACKGROUND: Moderate calorie-restricted diets and exercise training prevent loss of lean mass and cardiovascular risk. Because adherence to routine exercise recommendation is generally poor, we utilized recreational soccer training as a novel therapeutic exercise intervention in type 2 diabetes (T2D) patients. OBJECTIVE: We compared the effects of acute and chronic soccer training plus calorie-restricted diet on protein catabolism and cardiovascular risk markers in T2D. DESIGN, SETTING AND SUBJECTS: Fifty-one T2D patients (61.1±6.4 years, 29 females: 22 males) were randomly allocated to the soccer+diet-group (SDG) or to the diet-group (DG). The 40-min soccer sessions were held 3 times per week for 12 weeks. RESULTS: Nineteen participants attended 100% of scheduled soccer sessions, and none suffered any injuries. The SDG group showed higher levels of growth hormone (GH), free fatty acids and ammonia compared with DG. After 12 weeks, insulin-like growth factor binding protein (IGFPB)-3 and glucose levels were lower in SDG, whereas insulin-like growth factor (IGF)-1/ IGFBP-3 ratio increased in both groups. After the last training session, an increase in IGF-1/IGFBP-3 and attenuation in ammonia levels were suggestive of lower muscle protein catabolism. CONCLUSIONS: Recreational soccer training was popular and safe, and was associated with decreased plasma glucose and IGFBP-3 levels, decreased ammoniagenesis, and increased lipolytic activity and IGF-1/IGFBP-3 ratio, all indicative of attenuated catabolism.


Subject(s)
Biomarkers/blood , Caloric Restriction , Cardiovascular Diseases/blood , Diabetes Mellitus, Type 2/blood , Soccer , Absorptiometry, Photon , Aged , Blood Glucose/metabolism , Body Composition , Body Mass Index , Dietary Proteins/administration & dosage , Fatty Acids, Nonesterified/blood , Female , Glycated Hemoglobin/metabolism , Heart Rate , Humans , Insulin-Like Growth Factor Binding Protein 3/blood , Insulin-Like Growth Factor I/analysis , Male , Middle Aged , Oxygen Consumption , Postmenopause/blood , Risk Factors
20.
Clin Microbiol Infect ; 23(6): 373-380, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27851997

ABSTRACT

Currently, methicillin-resistant Staphylococcus aureus (MRSA) is a universal threat. After being well established in the healthcare setting, it has emerged in the community among people with no risk factors for MRSA acquisition, therefore imposing a new threat. The subsequent detection of MRSA colonizing or infecting animals as well as in food of animal origin was of major concern, revealing new reservoirs for MRSA. The major MRSA clonal lineages circulating in the different settings, i.e. in hospitals, in the community and among animals, are described here, differentiating between clones colonizing companion and food-chain animals. Particular attention is given to the widely spread livestock-associated MRSA clonal complex (CC) 398, which is mainly associated with professional exposure but may be of high pathogenicity. The recent detection of a mecA homologue, designated mecC, with a wide geographical distribution in Europe, and including a large diversity of hosts (food-chain, companion and wildlife animals and also detected in water samples) adds to the threat. Domestication as well as globalization of the livestock industry have intensified exchanges between human and animal bacteria. We report here several cases of transmission of MRSA between companion or food-chain animals and humans, as well as some MRSA clones of human origin that have adapted to new animal hosts eventually by losing useless virulence factors or acquiring new mobile genetic elements.


Subject(s)
Livestock/microbiology , Methicillin-Resistant Staphylococcus aureus/classification , Pets/microbiology , Staphylococcal Infections/veterinary , Africa , Animals , Asia , Australia , Europe , Food Microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Phylogeography , Staphylococcal Infections/microbiology
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