Evolutionary Pathways and Trajectories in Antibiotic Resistance.

Evolution is the hallmark of life. Descriptions of the evolution of microorganisms have provided a wealth of information, but knowledge regarding "what happened" has precluded a deeper understanding of "how" evolution has proceeded, as in the case of antimicrobial resistance. The difficulty in answering the "how" question lies in the multihierarchical dimensions of evolutionary processes, nested in complex networks, encompassing all units of selection, from genes to communities and ecosystems. At the simplest ontological level (as resistance genes), evolution proceeds by random (mutation and drift) and directional (natural selection) processes; however, sequential pathways of adaptive variation can occasionally be observed, and under fixed circumstances (particular fitness landscapes), evolution is predictable. At the highest level (such as that of plasmids, clones, species, microbiotas), the systems' degrees of freedom increase dramatically, related to the variable dispersal, fragmentation, relatedness, or coalescence of bacterial populations, depending on heterogeneous and changing niches and selective gradients in complex environments. Evolutionary trajectories of antibiotic resistance find their way in these changing landscapes subjected to random variations, becoming highly entropic and therefore unpredictable. However, experimental, phylogenetic, and ecogenetic analyses reveal preferential frequented paths (highways) where antibiotic resistance flows and propagates, allowing some understanding of evolutionary dynamics, modeling and designing interventions. Studies on antibiotic resistance have an applied aspect in improving individual health, One Health, and Global Health, as well as an academic value for understanding evolution. Most importantly, they have a heuristic significance as a model to reduce the negative influence of anthropogenic effects on the environment.

Evaluation of Bone Mineral Density in Patients with Type 1 Gaucher Disease in Argentina.

The purpose of this study was to evaluate the frequency of osteoporosis (OP) in patients with Gaucher disease (GD) in Argentina. GD patients from 28 centers were consecutively included from April 2012 to 2014. Bone mineral density (BMD) was determined by dual X-ray absorptiometry in the lumbar spine and the femoral neck or the total proximal femur for patients ≥20 yr of age, and by whole-body scan in the lumbar spine in patients <20 yr of age. In children, mineral density was calculated using the chronological age and Z height. OP diagnosis was determined following adult and pediatric official position of the International Society for Clinical Densitometry. A total of 116 patients were included, of which 62 (53.5%) were women. The median age was 25.8 yr. All patients received enzyme replacement therapy, with a median time of 9.4 yr. Normal BMD was found in 89 patients (76.7%), whereas low bone mass (LBM) or osteopenia was found in 15 patients (13%) and OP in 12 patients (10.3%). The analysis of the pediatric population revealed that 4 patients (9.3%) had LBM and 3 (7%) had OP (Z-score ≤ -2 + fractures height-adjusted by Z), whereas in the adult population (n = 73), 11 patients (15%) had LBM or osteopenia and 9 (12.3%) had OP. Bone marrow infiltration and the presence of fractures were significantly correlated with the presence of OP (p = 0.04 and <0.001, respectively). This is the first study in Argentina and in the region describing the frequency of OP or LBM in GD patients treated with imiglucerase using the official position of the International Society for Clinical Densitometry.

Hopf Bifurcations in Directed Acyclic Networks of Linearly Coupled Hindmarsh-Rose Systems.

This paper addresses the existence of Hopf bifurcations in a directed acyclic network of neurons, each of them being modeled by a Hindmarsh-Rose (HR) neuronal model. The bifurcation parameter is the small parameter corresponding to the ratio of time scales between the fast and the slow dynamics. We first prove that, under certain hypotheses, the single uncoupled neuron can undergo a Hopf bifurcation. Hopf bifurcation occurrences in a directed acyclic network of HR neurons are then discussed. Numerical simulations are carried out to observe these bifurcations and to illustrate the theoretical results.

Ubiquitin binds the amyloid ß peptide and interferes with its clearance pathways.

Several lines of evidence point to a compromised proteostasis associated with a reduction of the Ubiquitin Proteasome System (UPS) activity in patients affected by Alzheimer's Disease (AD) and suggest that the amyloid ß peptide (Aß) is an important player in the game. Inspired also by many reports, underlining the presence of ubiquitin (Ub) in the amyloid plaques of AD brains, here we set out to test whether Ub may bind the Aß peptide and have any effect on its clearance pathways. By using an integrated array of MALDI-TOF/UPLC-HRMS, fluorescence, NMR, SPR, Microscale Thermophoresis (MST) and molecular dynamics studies, we consistently demonstrated that Aß40 binds Ub with a 1 : 1 stoichiometry and K d in the high micromolar range. In particular, we show that the N-terminal domain of the Aß peptide (through residues D1, E3 and R5) interacts with the C-terminal tail of Ub (involving residues K63 and E64), inducing the central region of Aß (14HQKLVFFAEDVGSNK28) to adopt a mixed α-helix/ß-turn structure. ELISA assays, carried out in neuroblastoma cell lysates, suggest that Aß competitively binds Ub also in the presence of the entire pool of cytosolic Ub binding proteins. Ub-bound Aß has a lower tendency to aggregate into amyloid-like fibrils and is more slowly degraded by the Insulin Degrading Enzyme (IDE). Finally, we observe that the water soluble fragment Aß1-16 significantly inhibits Ub chain growth reactions. These results evidence how the non-covalent interaction between Aß peptides and Ub may have relevant effects on the regulation of the upstream events of the UPS and pave the way to future in vivo studies addressing the role played by Aß peptide in the malfunction of proteome maintenance occurring in AD.

The insulin degrading enzyme activates ubiquitin and promotes the formation of K48 and K63 diubiquitin.

We report an ATP-dependent ubiquitin conjugation with IDE which, in turn, promotes Ub-Ub linkages in tube tests. We propose a novel function for IDE as a non-canonical ubiquitin activating enzyme.

Informatics in palliative care.

A computerized documentation system for palliative care would allow immediate availability of patient data and rapid evaluation of treatment. To develop such a system, many problems must be resolved, including choice of data and type of display. A preliminary screening of information and the introduction of codes to show some parameters are necessary to achieve a good result. We describe a program that allows data entry, storage of data, rapid display and printout of data, and recording of history, previous therapy, pathologic, physical, and laboratory findings, diagnosis, mechanisms and site of pain, drugs, and symptoms. Further improvements and problems are discussed.

[Importance of an outpatient record in obstetric anesthesia]. / Importanza dell'ambulatorio di anestesia ostetrica.

A computerised record was used to collect data following an anesthesiological check-up of pregnant women at approximately 30 weeks of pregnancy. The record was input onto a portable PC in the anesthesia outpatient clinic, memorized on disk (3.5") and then transferred onto a PC network (one PC for each operating theatre) for "real time" consultation of each patient's data. All pregnant women attending the antenatal clinico were also given a folder illustrating epidural anesthetic techniques. Seven hundred and nine outpatient visits have been performed over the past two years with a 62% utilisation ratio. The collection of data using a computerised system allows a rapid and efficacious system of communication to be set up among the membranes of the anesthesiological team, thus encouraging the use of epidural techniques during labour. The distribution of the folder also facilitated the task of the anesthetist who found that pregnant women visiting the anesthesia clinic were already familiar with the epidural technique.

A visual representation of a model for monitoring the state of oxygenation in the critically ill patients. Description and clinical validation.

The authors propose a new circular diagram for monitoring the oxygenation status of critically ill patients. This diagram contains some well known parameters; other ones are suggested to evaluate the pulmonary function and the capability of blood oxygenation. The calculation and a "BASIC" program are provided to use the diagram. This method offers a fast and easy monitoring of oxygenation status by a very small arterious and central venous blood sample.

[Blood level of thyroid hormones in surgical thyroid diseases. Pre-,intra- and post-operative T3 and T4 levels]. / Sul tasso ematico di ormoni tiroidei nelle tiropatie chirurgiche: T3 e T4 pre-, intra- e post-operatori.

A pre-, intra- and post-operative determination of thyroid hormone in values in the peripheral and thyroid vein reflux blood of patients with thyroid disorders requiring surgery showed that the so-called intraoperative squeezing of the gland either does not place or is of little importance when delicate surgical movements are commenced. A low incidence of intraoperative arrhythmia was also noted. Prevention of the latter is not indicated, since it is often dependent on surgical movements and/or unorthodox anaesthesiological management.

[A quick and simple method for estimating the oxyhemoglobin dissociation curve]. / Une méthode rapide et simple pour l'estimation de la position de la courbe de dissociation de l'oxyhémoglobine.

The methods currently available for assessing the oxyhaemoglobin dissociation curve parameters are expensive, lengthy, require a large volume of blood, and the results obtained are modified by anaesthetic gases. The equipment required for the method described includes: a microtonometre, microcuvettes, 3 gas bottles containing different oxygen, carbon dioxide and nitrogen mixtures (4.5%, 5.6%, 89.9%; 3.5%, 5.6%, 90.9%; 2.5%, 5.6%, 91.9% respectively), a microxymetre, and a micropHmetre. The samples in the microcuvettes are incubated at 37 degrees C in a gas flow of 45 ml.min-1 from the bottles. SO2 is then read using the microxymetre. P50, i.e. PO2 at 50% saturation, is calculated, as well as Hill's number "n" (the angle of the oxyhaemoglobin dissociation curve). The PO2 required for Hill's formula is also calculated from the atmospheric pressure, the water vapour partial pressure, and the oxygen fraction in the gas bottle used. Normal values obtained by this method were P50: 26.5 +/- 1.5 mmHg; Hill's number: 2.65 +/- 0.35. The method presented here, requiring only 300 microliters of blood, is cheap, reliable, not affected by anaesthetic drugs, and quick.

[Neuroendocrine response to anesthesia with isoflurane]. / La réponse neuro-endocrinienne à l'anesthésie par isoflurane.

The effects during surgery of a new halogenated volatile anaesthetic, isoflurane, on the hypothalamo-hypophyseal-thyroid-suprarenal axis were studied. In fact, it was important to prove whether this new halogenated anaesthetic would provide better protection, for the patient, from surgery and anaesthetic stress compared with other anaesthetic agents in use. The study was carried out in 16 young class ASA I patients who were to undergo appendicectomy. Before and during operation, blood was taken to measure ACTH, cortisol, TSH, T3, T4 and PRL plasma levels. A remarkable increase of PRL, cortisol and T4 plasmatic rate was found, especially at the end of the operation. It was concluded that isoflurane, just like enflurane, did not prevent the increase of PRL, cortisol and T4 that usually takes place during surgery.

[In vitro and in vivo effects of propofol on the hemoglobin dissociation curve]. / Effets du propofol sur la courbe de dissociation de l'oxyhémoglobine in vivo et in vitro.

This study assessed in vivo and in vitro the effects of propofol on the affinity of hemoglobin for oxygen in seven ASA 1 adults. For the in vivo study, venous blood samples were withdrawn before and after premedication, after the injection of 2.5 mg.kg-1 of propofol and after 15 minutes of maintenance at an infusion rate of 0.2 mg.kg-1.min-1. For the in vitro study, propofol was added to the blood withdrawn before premedication in order to obtain two samples at a concentration of 1 microgram.mL-1 and 2 micrograms.mL-1 respectively. Propofol changed neither in vivo, nor in vitro, the P50 and the number of Hill indicating the angle of the slope of the dissociation curve, nor in vivo the concentration of 2,3-DPG.

[Effect promoting the rejection of an allograft of skin in rabbits treated with a high dose of amethopterin]. / Sull'effetto promuovente la reiezione di un alloinnesto di cute nel coniglio trattato con una dose elevata di ametopterina.

Present results show that the preventive inoculation of a single high dose of ametopterin (Methotrexate: MTX) may induce in rabbits the accelerated rejection of a skin allograft. This finding is sustained by an enhancing or adjuvant action of the agent on the mechanism of cell-mediated immunity.

Infecção de sítio cirúrgico em revascularizações do miocárdio: estudo retrospectivo / Surgical site infection in myocardial revascularization: a retrospective study

Objetivo: analisar a incidência de infecção do sítio cirúrgico em revascularizações do miocárdio. Métodos: estudo quantitativo com 314 prontuários de pacientes submetidos às revascularizações no período de 2014 a 2016, do serviço de cirurgia cardíaca. Foram avaliadas as relações de variáveis operatórias com o aparecimento de infecção de sítio cirúrgico para determinar os fatores significativos. Para a coleta dos dados utilizou-se as fichas de circulação extracorpórea e para a análise as definições estabelecidas pela Agência Nacional de Vigilância Sanitária. Resultados: 66,2% eram do sexo masculino; 62,1%, brancos; 47,3%, hipertensos; 22,8%, diabéticos e 91,7%, cirurgias eletivas. Evidenciou-se que febre, edema local em 24 horas, dor, necrose em lesão operatória e (re)abordagem cirúrgica são os principais fatores para incidência de infecções relacionada ao tempo médio de circulação extracorpórea e de cirurgia. Conclusão: a infecção de sítio cirúrgico em revascularizações está relacionada com o tempo de cirurgia e de circulação extracorpórea.

Objective: to analyze the incidence of surgical site infection in myocardial revascularizations.Methods: a quantitative study with 314 medical records of patients submitted to revascularizationin the period from 2014 to 2016, of the cardiac surgery service. The relationships of operativevariables with the appearance of surgical site infection were evaluated to determine the significantfactors. Data collection was done using the cardiopulmonary bypass records and for the analysis thedefinitions established by the National Sanitary Surveillance Agency. Results: 66,2% were male;62,1% white; 47,3% hypertensive and 22,8% diabetic; 91.7% were elective surgeries. It was evidencedthat fever, local edema in 24 hours, pain, necrosis in operative lesion and surgical intervention are the main factors for the incidence of infections related to the mean time of extracorporealcirculation and surgery. Conclusion: the surgical site infection in revascularizations is related to thetime of surgery and extracorporeal circulation.

Emerging dynamics in neuronal networks of diffusively coupled hard oscillators.

Oscillatory networks are a special class of neural networks where each neuron exhibits time periodic behavior. They represent bio-inspired architectures which can be exploited to model biological processes such as the binding problem and selective attention. In this paper we investigate the dynamics of networks whose neurons are hard oscillators, namely they exhibit the coexistence of different stable attractors. We consider a constant external stimulus applied to each neuron, which influences the neuron's own natural frequency. We show that, due to the interaction between different kinds of attractors, as well as between attractors and repellors, new interesting dynamics arises, in the form of synchronous oscillations of various amplitudes. We also show that neurons subject to different stimuli are able to synchronize if their couplings are strong enough.

Conversion of spinal anesthesia into general anesthesia: an evaluation of more than 35,000 spinal anesthetics.

BACKGROUND: The aim of this study was to evaluate the number of conversions from spinal anesthesia (SA) into general anesthesia (GA) in a large number of patients who underwent surgery over a period of twenty-one years. METHODS: From the hospital's database, all surgical procedures performed under SA between January 1, 1988 and December 31, 2008 were retrieved. From this file, all SA cases converted into GA cases requiring endotracheal intubation were selected. Patients were divided in four groups, according to the reason for GA: IMPOSS (SA impossible to perform), FAIL (SA non profound enough for allowing surgery, even with light sedation), INSUFF (SA inadequate for unexpected prolonged duration of surgery), and COMPL (occurrence of complications associated with SA and requiring rapid control of ventilation). Anesthesiologists who performed SA were divided according their experience. The outcomes of patients converted to GA were compared with a matched sample of patients who received planned GA. RESULTS: A total of 35,960 SA cases were performed from 1988 to 2008; 29,220 and 6,740 SA cases were for elective and emergency surgery, respectively. Two hundred seventeen (0.6%) SA cases were converted into GA cases; 80.2% and 19.8% of the conversions were recorded in elective and emergency operations, respectively, with obstetric operations being the most prevalent (82/217). The primary reasons for the conversions, in a rank order, were INSUFF 107 (49.3%), FAIL 84 (38.7%), IMPOSS 13 (5.9%), and COMPL 13 (5.9%). Complications more frequently occurred in the aged population (P<0.05). Anesthesiologists with less experience had higher percentages of FAIL, IMPOSS, INSUFF, and COMPL SA cases in comparison with experienced anesthesiologists (odd ratios being 4.7, 3.0, 2.4, and 4.4, respectively). There was no difference in the frequency of complications compared to a matched sample of 1,000 patients who underwent GA (P=0.65). CONCLUSION: SA has been found to be a safe and highly effective technique. Failure of SA was infrequent in a large number of patients surveyed and most often occurred with less experienced anesthesiologists. Conversion to GA did not produced different outcomes in comparison with planned GA. Prospective studies with a definite protocol for recording data performed on a large number of patients may help in determining the factors associated with conversion from SA into GA and how to avoid these unexpected situations.

Evaluación del grado de buena prescripción médica en 5 Hospitales Universitarios de tercer nivel de la ciudad de La Paz (Bolivia) / Assesment of the degree of a good medical prescriptionin 5 third level University Hospitals in the city of La Paz - Bolivia

OBJETIVO: establecer el grado de cumplimiento de Buenas Prácticas de Prescripción Médica sugeridas por la Organización Mundial de la Salud (OMS) analizando recetas extendidas a pacientes de consulta externa e internados de 5 hospitales universitarios de la ciudad de La Paz (Bolivia), identificando limitaciones y deficiencias en su formulación. MÉTODOS: estudio descriptivo, retrospectivo de evaluación de recetas, según disposiciones de la ley No.1737 (1996) de Bolivia, las Normas Nacionales de Atención Clínica del Ministerio de Salud Boliviano (2013) y el Manual de la Buena Prescripción de la OMS. RESULTADOS: del análisis de 220 recetas se desprende que la proporción de recetas que cumple con la mayoría de parámetros sugeridos por la OMS para una buena prescripción médica es baja. Las recetas que tienen identificación del prescriptor son 37,27%; 66,82%, no señala el origen de la prescripción; 15% incumple con una adecuada filiación del paciente, incluyendo el nombre del paciente, 80,91% no incluían la edad del paciente, 10,91% no estaban con nombre genérico del medicamento; 11,82% estaban con nombre comercial, 5,45% no contaban con nombre completo ni firma del prescriptor; 13,64% no incluía fecha de la prescripción. Un 34,09% tenían letra poco legible y 29.54% letra no legible. Estos datos, entre otros, indican la necesidad de reflexión y actualización sobre este importante tema. CONCLUSIONES: Se registra un elevado índice de incumplimiento de las normas de buena prescripción señaladas por las regulaciones antes mencionadas, identificando la necesidad de re-orientar los hábitos de prescripción facultativa a fin que no repercutan negativamente en la salud y tratamiento de los pacientes y en las acciones del Sistema Nacional de Salud. El formato de receta médica utilizado en los diferentes servicios de salud objeto del estudio es deficiente en cuanto al modelo y guía sugerida por la OMS.

OBJECTIVE: to establish the degree of compliance with good medical prescription practices suggested by the World Health Organization (WHO) analyzing prescriptions issued to outpatients and admitted patients of 5 university hospitals in the city of La Paz (Bolivia), identifying limitations and deficiencies in its formulation. METHODS: descriptive, longitudinal, retrospective study of prescription assesment, according to provisions of Law No.1737 (1996) of Bolivia, the National Standards for Clinical Care Bolivian Ministry of Health (2013) and the Manual of Good Prescription the World Health Organization (WHO). RESULTS: analysis of 220 prescriptions show that the proportion of prescriptions that meet most of the parameters suggested by WHO for a good prescription is down. 37,27% of prescriptions have prescriber identification; 66.82%, do not indicate the origin of the prescription, 15% fail to comply with proper affiliation of the patient, including the patient's name, 80.91% did not have included patient age, 10.91% of prescriptions were not made by generic drug name; 11.82% were prescribed with trade name, 5.45% had no full name or signature of the prescriber; 13.64% did not include prescription date. 36.36% were made legibly a 34.09% with little legibly and 29.54% with no legible. These data, among others, indicate the need for reflection and update on this important topic. CONCLUSIONS: it has been registered a high rate of non-compliance with good prescription for the above mentioned regulations, identifying the need to re-direct professional prescription habits so that no negative impact on the health and treatment of patients and the actions of the National Health System (NHS) is done. The format of prescription used in various health services under study is deficient in terms of model and guide suggested by the WHO.