Synergistic efficacy of ceftazidime/avibactam and aztreonam against carbapenemase-producing Pseudomonas aeruginosa: insights from the hollow-fiber infection model.

BACKGROUND: Combination therapy is an attractive therapeutic option for extensively drug-resistant (XDR) Pseudomonas aeruginosa infections. Existing data support the combination of aztreonam and ceftazidime/avibactam (CZA) against class serine-ß-lactamase (SBL)- and metallo-ß-lactamase (MBL) - producing Enterobacterales. However, data about that combination against SBL- and MBL-producing P. aeruginosa are scarce. The objective of the study was to assess the in vitro activity of CZA and aztreonam alone and in combination against SBL- and MBL-producing XDR P. aeruginosa isolates. METHODS: The combination was analyzed by means of the hollow-fiber infection model in three selected carbapenemase-producing P. aeruginosa isolates that were representative of the three most common XDRP. aeruginosa high-risk clones (ST175, ST111, ST235) responsible for global nosocomial infection outbreaks. RESULTS: The three isolates were nonsusceptible to CZA and nonsusceptible to aztreonam. In the dynamic hollow-fiber infection model, the combination of CZA plus aztreonam exerts a bactericidal effect on the isolates, regardless of their resistance mechanism and demonstrates synergistic interactions against three isolates, achieving a bacterial reduction of 5.07 log10 CFU/ml, 5.2 log10 CFU/ml and 4 log10 CFU/ml, respectively. CONCLUSION: The combination of CZA and aztreonam significantly enhanced the in vitro efficacy against XDR P. aeruginosa isolates compared to each monotherapy. This improvement suggests that the combination could serve as a feasible treatment alternative for infections caused by carbapenemase-producing XDR P. aeruginosa, especially in scenarios where no other treatment options are available.

Phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae): Diversity of potential Leishmania vectors in northern Colombia.

Phlebotomine sand flies are critical vectors of Leishmania parasites, impacting public health significantly. This study focused on assessing the diversity of sand flies in a rural area of El Carmen de Bolívar Municipality, northern Colombia, employing rarefaction curves and Hill numbers to understand potential vector communities and inform environmental management. From January 2018 to April 2019 (five samplings), sand flies were collected using CDC light traps with blue LED in domestic/peridomestic/sylvatic ecotopes, identifying species per Young and Duncan (1994) and Galati (2003). Hill numbers provided diversity estimates across samples, while Principal Component Analysis correlated with environmental factors with phlebotomine species presence and abundance. 8,784 phlebotomine individuals were collected; 56.4 % females and 43.6% males (ratio 3:2). These individuals belonged to eight species: Pintomyia evansi, Psychodopygus panamensis, Lutzomyia gomezi, Micropygomyia cayennensis, Evandromyia dubitans, Psathyromyia aclydifera, Pintomyia serrana, and Pintomyia rangeliana; with Pi. evansi being the most abundant species (74.39 %; 6,530 exemplars). The ANOVA showed no significant differences between phlebotomine sand flies abundances across ecotopes (p = 0.018). Species of epidemiological relevance as Pi. evansi and Lu. gomezi not show a positive correlation with environmental variables evaluated, only Ps. panamensis was positively correlated with precipitation. However, the study emphasizes the need for a continuous sand fly monitoring and research to enhance leishmaniasis control strategies, highlighting the necessity to expand knowledge on phlebotomine diversity and environmental interactions to understand vector ecology and disease dynamics better.

The impact of a two-year long COVID-19 public health restriction program on mechanical thrombectomy outcomes in a stroke network.

OBJECTIVE: The purpose of this study was to evaluate the impact of COVID-19 pandemic public health restrictions on our drip and ship mechanical thrombectomy program in Santiago Chile. MATERIALS AND METHODS: This was a retrospective analysis of a prospectively collected database comparing two cohorts, one during a two-year period before COVID-19 and the second during the two years of the pandemic at our metropolitan stroke program. RESULTS: A total of 100 patients were included in the pre COVID-19 cohort (cohort 1) and 121 in the COVID-19 cohort (cohort 2). There was a significant difference between cohorts, with older patients, different occlusion sites and higher door to arterial puncture time during the COVID-19 period. A non-significant trend for worse 90-day outcomes and higher mortality was present in cohort 2. There were no statistical differences in safety treatment parameters. CONCLUSIONS: COVID-19 pandemic has had a measurable impact on our mechanical thrombectomy program. Results showed similarities to other reported Latin American series, where less robust health systems could adapt less efficiently compared to developed countries. After two years of public health restrictions, there were changes in the treatment population characteristics, delay in some internal management metrics and a non-significant trend to worse 90-day outcomes and higher mortality.

A novel self-expanding shape memory polymer coil for intracranial aneurysm embolization: 1 year follow-up in Chile.

BACKGROUND: Aneurysm recurrence remains a challenge when coiling cerebral aneurysms. Development of next generation coils has focused on accelerating thrombus maturation and increasing coil packing density. Ultra low density shape memory polymer is a novel embolic material designed for this purpose. The polymer is crimped over a platinum-tungsten coil for catheter delivery and self-expands to a predefined volume on contact with blood. METHODS: This prospective study in humans evaluated aneurysms 5-16 mm (inclusive) in diameter that were indicated for endovascular coil embolization. At least 70% coil volume was required to be shape memory polymer coils. Patients were followed-up according to standard of care for 12 months. RESULTS: Nine patients (89% women, mean age 55.8±11.7 years) were treated with shape memory polymer coils and completed 12 months of follow-up. Aneurysms were all unruptured and were in the ophthalmic segment of the internal carotid artery (n=7), posterior communicating artery, and anterior cerebral artery A1-A2 segment. Aneurysms were a mean of 7.8±2.9 mm in diameter (range 5.2-14.9 mm). The mean packing density based on unexpanded polymer was 17±6%. Packing density based on expanded polymer was 43±13%. At 12 months, no recurrence had occurred, and a Raymond-Roy occlusion classification of 1 (n=5) or 2 (n=4) was observed. No serious adverse events related to the study device occurred over the 12 months after the procedure. CONCLUSIONS: Shape memory polymer coils were safe and effective in treating intracranial aneurysms over 12 months in this first study in human subjects.

Suboptimal Concentrations of Ceftazidime/Avibactam (CAZ-AVI) May Select for CAZ-AVI Resistance in Extensively Drug-Resistant Pseudomonas aeruginosa: In Vivo and In Vitro Evidence.

This study correlates in vivo findings in a patient with an extensively drug-resistant (XDR) P. aeruginosa infection who developed resistance to ceftazidime-avibactam (CAZ-AVI) with in vitro results of a 7-day hollow-fiber infection model (HFIM) testing the same bacterial strain. The patient was critically ill with ventilator-associated pneumonia caused by XDR P. aeruginosa ST175 with CAZ-AVI MIC of 6 mg/L and was treated with CAZ-AVI in continuous infusion at doses adjusted for renal function. Plasma concentrations of CAZ-AVI were analyzed on days 3, 7, and 10. In the HIFM, the efficacy of different steady-state concentrations (Css) of CAZ-AVI (12, 18, 30 and 48 mg/L) was evaluated. In both models, a correlation was observed between the decreasing plasma levels of CAZ-AVI and the emergence of resistance. In the HIFM, a Css of 30 and 48 mg/L (corresponding to 5× and 8× MIC) had a bactericidal effect without selecting resistant mutants, whereas a Css of 12 and 18 mg/L (corresponding to 2× and 3× MIC) failed to prevent the emergence of resistance. CAZ/AVI resistance development was caused by the selection of a single ampC mutation in both patient and HFIM. Until further data are available, strategies to achieve plasma CAZ-AVI levels at least 4× MIC could be of interest, particularly in severe and high-inoculum infections caused by XDR P. aeruginosa with high CAZ-AVI MICs.

First multicenter experience using the Silk Vista flow diverter in 60 consecutive intracranial aneurysms: technical aspects.

BACKGROUND: The aim of this study was to assess the technical success and procedural safety of the new Silk Vista device (SV) by evaluating the intraprocedural and periprocedural complication rate after its use in several institutions worldwide. METHODS: The study involved a retrospective review of multicenter data regarding a consecutive series of patients with intracranial aneurysms, treated with the SV between September 2020 and January 2021. Clinical, intra/periprocedural and angiographic data, including approach, materials used, aneurysm size and location, device/s, technical details and initial angiographic aneurysm occlusion, were analyzed. RESULTS: 60 aneurysms were treated with SV in 57 procedures. 66 devices were used, 3 removed and 63 implanted. The devices opened instantaneously in 60 out of 66 (91%) cases and complete wall apposition was achieved in 58 out of 63 (92%) devices implanted. In 4 out of 66 (6%) devices a partial opening of the distal end occurred, and in 5 (8%) devices incomplete apposition was reported. There were 3 (5%) intraprocedural thromboembolic events managed successfully with no permanent neurological morbidity, and 4 (7%) postprocedural events. There was no mortality in this study. The initial occlusion rates in the 60 aneurysms were as follows: O'Kelly-Marotta (OKM) A in 34 (57%) cases, OKM B in 15 (25%) cases, OKM C in 6 (10%) cases, and OKM D in 5 (8%) cases. CONCLUSIONS: Our study demonstrated that the use of the new flow diverter Silk Vista for the treatment of intracranial aneurysms is feasible and technically safe.

Breaking the breach in Latin America: A pilot study of mechanical thrombectomy in the public healthcare system in Chile.

BACKGROUND: Mechanical Thrombectomy (MT) is the standard of care for treatment of large vessel occlusion stroke. Until the beginning of 2020 MT was not funded nor widely implemented at the public healthcare level in Chile. OBJECTIVE: To describe the results of a pilot program created to provide access to public MT in Santiago - Chile. METHODS: Analysis from a prospectively collected database of MT cases performed between September 2017 and September 2019 in one center. A stroke network was developed with a single MT capable stroke center and five primary stroke centers. The primary efficacy endpoint was the rate of functional independence (mRS 0-2) at 90 days. Successful reperfusion was defined as 2 b-3 according to the thrombolysis in cerebral infarction scale. Safety outcomes include the rates of symptomatic intracranial hemorrhage and 90-day mortality. RESULTS: A total of 100 patients were treated over the study period. Their mean age was 62.8 ± 11.8 years and median baseline National Institute of Health Stroke Scale (NIHSS) measurement was 17. Seventy-seven percent of the patients received intra venous thrombolysis. Successful reperfusion was achieved in 95% of the cases. NIHSS at 24 hours showed a median drop of 7 points from baseline (p < 0.00001) and 50% of the follow-up patients were functionally independent at 90 days. Symptomatic Intracerebral hemorrhage occurred in 5% of the patients and 90-day all case mortality was 11%. CONCLUSIONS: We demonstrated the feasibility of a publicly funded MT program in Chile, with similar results as other international randomized control trials.

Análisis cuantitativo, uso de Escala Braden por enfermería en el servicio de Medicina Interna del Hospital Santo Domingo / Quantitative analysis of the use of Braden Scale by nursing in the Internal Medicine service of the Hospital Santo Domingo

Resumen El objetivo de este estudio fue evaluar, mediante un análisis cuantitativo, el uso y aplicación de la Escala de Braden por el personal de enfermería en pacientes de medicina interna del Hospital Santo Domingo, año 2018. Es un estudio cuantitativo, transversal y descriptivo; la población total fue de 1017 pacientes con una muestra de 30 (12 masculinos y 18 feminas), ingresados al área de medicina interna del Hospital General Santo Domingo, provincia Santo Domingo de los Tsáchilas, de julio a agosto del 2018. Se les realizó una revisión de su historia clínica para conocer el puntaje que determinaba el riesgo de desarrollar úlceras por presión (UPP), según la valoración que recibieron mediante la escala. Durante la aplicación de la Escala de Braden, se pronosticó riesgo bajo a 15 pacientes, riesgo medio a 10 y riesgo alto a 5, quienes presentaron alteraciones neurológicas o enfermedades crónicas como: accidente cerebrovascular, diabetes mellitus, cirrosis hepática. Se concluye que el personal de enfermería no realiza una aplicación adecuada de la Escala de Braden ni desde el ingreso del paciente ni durante su reevaluación en el servicio de medicina interna, lo que trae consigo que la atención no se realice con la calidad requerida. Factor favorable para complicaciones como las UPP.

Abstract The objective of this study was to evaluate, through a quantitative analysis, the use and application of the Braden Scale by the nursing staff in internal medicine patients of the Santo Domingo Hospital, year 2018. It is a quantitative, cross-sectional and descriptive study; The total population was 1017 patients with a sample of 30 (12 males and 18 females), admitted to the internal medicine area of the Santo Domingo General Hospital, Santo Domingo de los Tsáchilas province, from July to August 2018. They underwent a review of their medical history to know the score that determined the risk of developing pressure ulcers (UPP), according to the assessment they received using the scale. During the application of the Braden Scale, low risk was predicted for 15 patients, medium risk for 10 and high risk for 5, who presented neurological disorders or chronic diseases such as: stroke, diabetes mellitus, liver cirrhosis. It is concluded that the nursing staff does not carry out an adequate application of the Braden Scale, neither since the patient's admission nor during his reevaluation in the internal medicine service, which means that the care is not performed with the required quality. Favorable factor for complications such as UPP.

Resumo O objetivo deste estudo foi avaliar, por meio de uma análise quantitativa, o uso e a aplicação da Escala de Braden pela equipe de enfermagem em pacientes de medicina interna do Hospital Santo Domingo, ano de 2018. Trata-se de um estudo quantitativo, transversal e descritivo; A população total foi de 1017 pacientes, com uma amostra de 30 (12 homens e 18 mulheres), admitidos na área de medicina interna do Hospital Geral de Santo Domingo, província de Santo Domingo de los Tsáchilas, de julho a agosto de 2018. Eles foram submetidos a uma revisão do histórico médico para conhecer o escore que determinou o risco de desenvolver úlceras por pressão (UPP), de acordo com a avaliação que receberam usando a escala. Durante a aplicação da Escala de Braden, foram previstos baixo risco para 15 pacientes, risco médio para 10 e alto risco para 5, que apresentavam distúrbios neurológicos ou doenças crônicas como: acidente vascular cerebral, diabetes mellitus, cirrose hepática. Conclui-se que a equipe de enfermagem não realiza uma aplicação adequada da Escala de Braden, nem desde a admissão do paciente nem durante sua reavaliação no serviço de medicina interna, o que significa que o cuidado não é realizado com a qualidade exigida. Fator favorável a complicações como UPP.

Is pulse oximetry helpful for the early detection of critical congenital heart disease at high altitude?

OBJECTIVE: To assess the pulse oximetry as a method for screening critical congenital heart disease (CHD) in newborns. STUDY DESIGN: This is an observational, transversal, descriptive simple study. The pre-ductal and postductal saturation were taken in term newborns that fulfilled the criteria of inclusion and exclusion in the Hospital Gineco-Obstetrico Isidro Ayora (HGOIA) in Quito. These measurements were performed between the 24 and 48 h after birth. Those newborns that saturated less than 90% on initial pulse oxìmetry underwent 3 successive measurements at 1-h intervals. Those who saturate less than 90% after 3 measurements or have a difference higher than 3% in preductal saturation and postductal saturation (positive screening) underwent transthoracic echocardiography evaluate for CHD. RESULTS: Pulse oximetry from 963 newborns was evaluated. In Quito, at an altitude of 2820 meters above sea level (9252 feet), the mean preductal saturation was 92.76% (SD ± 3) and the postductal saturation, 93.76% (SD ± 4.7). Pulse oximetry in 53 patients (5.5%) was classified as a positive screening. No critical congenital heart diseases were found. Atrial septal defect (ASD) was the most common finding in a 46.94% (n = 23), followed by the association of patent ductus arteriosus (PDA) and ASD with a 12.24% (n = 6). CONCLUSION: In this cohort of patients who underwent screening pulse oximetry, no critical congenital heart diseases (CHD) were observed. However, identifying those with oxygen saturation less than 90% after 3 successive measurements or a pre- and postductal oxygen difference of > 3% resulted in successful identification of ASD and PDA. It is necessary to implement new cutoff points in saturation values to identify critical cardiac anomalies in cities placed at a high altitude. The use of pulse oximetry should be recommended in all the newborns.

Quantitative evaluation of arteriovenous malformation hemodynamic changes after endovascular treatment using parametric color coding: A case series study.

Background Brain arteriovenous malformations (AVMs) are complex vascular lesions. Endovascular treatment results are usually measured by calculating the volume reduction of the lesions. Nevertheless, vascular flow quantification seems a more physiologically accurate way of measuring endovascular results. We evaluated the use of parametric color coding (PCC) with digital subtraction angiography (DSA), in order to determine the feasibility of PCC to detect and measure the impact of AVM endovascular treatment-induced changes using real-time hemodynamic parameters. Methods and results Supratentorial brain AVM treatment was evaluated in 29 patients over the course of 38 sessions. Using regions of interest (ROIs) at the carotid siphon, arterial feeder, drainage vein and venous sinus, we found significant increase in time to peak (TTP) values at the arterial feeder, drainage vein and venous sinus. We compared TTP in four different embolization volume groups: I (0-25%), II (26-50%), III (51-75%) and IV (76-100%). We found significant differences between groups and a moderate correlation between embolization percentages, as well as an increase in TTP at the main vein ROI; but not in the arterial side or sinus. Conclusions Brain AVM endovascular treatment results can be quantified in vivo with PCC. PCC is capable of detecting hemodynamic changes after brain AVM endovascular treatment, that may reflect flow drop, and it is correlated with volume embolization.

Unusual origin of the left ophthalmic artery from the basilar trunk.

The formation of the ophthalmic artery (OA) is a complex process with two different proposed embryological steps for its development. Several anatomical variants have been described. We present a very unusual origin of the ophthalmic artery from the basilar trunk, in a 45-year-old male with a history of pontine hemorrhagic stroke. MRI and CTA showed evidence of previous hemorrhage in the pons and several intracranial arterial dysplastic dilatations. DSA confirmed several fusiform dilatations of the basilar trunk. In the left ICA, no ophthalmic artery was seen arising from the carotid siphon. The left ophthalmic artery arises from the basilar trunk and runs lateral to the cavernous sinus through the middle cranial fossa, entering the left orbit at the superior orbital fissure. The patient was treated conservatively. Two main theories for this anomaly are known, one from Lasjaunias and the other from Paget. To our knowledge, this basilar origin of the OA has only been described three times in the literature. For its origin, we propose a partial persistence of the trigeminal artery together with a dominance of the dorsal ophthalmic artery.

Variable sampling approach to mitigate instability in networked control systems with delays.

This paper analyzes a new alternative approach to compensate for the effects of time delays on a dynamic networked control system (NCS). The approach is based on the use of time-delay-predicted values as the sampling times of the NCS. We use a one-step-ahead prediction algorithm based on an adaptive time delay neural network. The application of pole placement and linear quadratic regulator methods to compute the feedback gains taking into account the estimated time delays is investigated.

Conorfamide-Sr2, a gamma-carboxyglutamate-containing FMRFamide-related peptide from the venom of Conus spurius with activity in mice and mollusks.

A novel peptide, conorfamide-Sr2 (CNF-Sr2), was purified from the venom extract of Conus spurius, collected in the Caribbean Sea off the Yucatan Peninsula. Its primary structure was determined by automated Edman degradation and amino acid analysis, and confirmed by electrospray ionization mass spectrometry. Conorfamide-Sr2 contains 12 amino acids and no Cys residues, and it is only the second FMRFamide-related peptide isolated from a venom. Its primary structure GPM gammaDPLgammaIIRI-nh2, (gamma, gamma-carboxyglutamate; -nh2, amidated C-terminus; calculated monoisotopic mass, 1468.72Da; experimental monoisotopic mass, 1468.70Da) shows two features that are unusual among FMRFamide-related peptides (FaRPs, also known as RFamide peptides), namely the novel presence of gamma-carboxyglutamate, and a rather uncommon C-terminal residue, Ile. CNF-Sr2 exhibits paralytic activity in the limpet Patella opea and causes hyperactivity in the freshwater snail Pomacea paludosa and in the mouse. The sequence similarities of CNF-Sr2 with FaRPs from marine and freshwater mollusks and mice might explain its biological effects in these organisms. It also resembles FaRPs from polychaetes (the prey of C. spurius), which suggests a natural biological role. Based on these similarities, CNF-Sr2 might interact with receptors of these three distinct types of FaRPs, G-protein-coupled receptors, Na+ channels activated by FMRFamide (FaNaCs), and acid-sensing ion channels (ASICs). The biological activities of CNF-Sr2 in mollusks and mice make it a potential tool to study molecular targets in these and other organisms.