Optimising non-invasive mechanical ventilation: Which unit should care for these patients? A cohort study.

BACKGROUND: Use of noninvasive ventilation (NIV) has extended beyond intensive care units (ICUs), becoming usual practice in emergency departments (EDs) and general wards. OBJECTIVE: To analyse the relationship between nursing care and NIV outcome in different hospital units. DESIGN AND SETTINGS: Three university hospitals and one community hospital participated in a prospective observational cohort study. PARTICIPANTS: Ten units participated: 4 ICUs (1 surgical, 3 medical-surgical), 3 recovery (1 postsurgical, 2 EDs, 3 general wards). METHOD: Treatment success/failure, interface intolerance and complications were evaluated according to patient characteristics, nursing care provided, and procedures used. Complications analysed included bronchoaspiration, pneumothorax, skin lesions, inability to manage secretions, eye irritations, deteriorating level of consciousness, gastric distension, and excessive air losses around the mask. RESULTS: Of 387 patients, 194 (50.1%) were treated in ICU, 121 (31.3%) in ED, 38 (9.8%) postsurgery, and 34 (8.8%) in general wards. Regression analysis, adjusted for APACHE score and NIV indication, showed 3.3 times greater risk of NIV failure (95% CI [1.2-9.2]) in a university-hospital ICU with <50 NIV cases/year, compared to a community hospital ICU. In ICUs and general wards, NIV was suspended in 12% of patients due to interface intolerance. Acute-on-chronic lung diseases (ACLD) had lower risk of NIV failure (OR 0.2 [95% CI 0.06-0.69]) and lack of humidification was not associated with treatment failure (OR 0.2 [95% CI 0.1-0.4]). Poor secretion management was linked to pneumonia (OR 2.5 [95% CI 1.1-5.9]) and early weaning/extubation (OR 3.3 [95% CI 1.2-8.9]). Interface intolerance was associated with conventional ICU ventilators (OR 4.4 [95% CI 2.1-9.2]) and nasal skin lesions with excessive air losses (OR 2.4 [95% CI 1.1-5.3]), especially with oronasal masks (OR 3.5 [95% CI 1.1-11.3]). CONCLUSIONS: Acute respiratory failure patients with pneumonia admitted to general wards had increased interface intolerance and NIV failure. Rotating mask types could improve NIV success in any unit administering this therapy.

Molecular phylogenetics of the white-lipped peccary (Tayassu pecari) did not confirm morphological subspecies in northwestern South America.

We sequenced the mitochondrial DNA (mtDNA) control region of 59 peccaries (44 white-lipped peccaries, Tayassu pecari, and 15 collared peccaries, Pecari tajacu). We also genotyped 3 DNA microsatellites from 78 white-lipped peccaries representing the 4 putative morphological subspecies (i.e., spiradens, aequatoris, pecari, and albirostris) present in northwestern South America (i.e., Colombia, Ecuador, Peru, and Bolivia). Our results showed: 1) the estimated diversity of the mtDNA control region in the T. pecari population was extremely high, whereas the average genetic diversity for the microsatellites was medium to high and similar to that observed in European pig breeds; 2) there was no significant genetic heterogeneity among the quoted putative morphological subspecies at the mitochondrial marker, but we did detect significant (although relatively small) genetic heterogeneity using microsatellites, indicating that T. pecari albirostris is a uniquely differentiated group; and 3) the phylogenetic mtDNA trees showed that haplotypes were intermixed independent of their "a priori" subspecies classification. In addition, the microsatellite assignation analyses yielded low percentages of well-classified individuals when the analysis considered the geographic morphology of the subspecies. Thus, the molecular results do not support the putative morphological subspecies of T. pecari in northwestern South America. Finally, our results did not detect clear historical demographic changes using the mtDNA control region sequences. These genetic results are discussed in the context of the ecological and social characteristics of T. pecari.

Analysis of the genetic variability and structure of Ochlerotatus taeniorhynchus (Diptera: Culicidae) populations from the Colombian Atlantic coast on the basis of random amplified polymorphic DNA markers.

Ochlerotatus taeniorhynchus (Diptera: Culicidae) is a mosquito, which is an efficient vector of the virus causing epidemic-epizootic Venezuelan equine encephalitis in Colombia. This study used 9 random amplified polymorphic DNA (RAPD) markers to analyze the mosquito's genetic variability and genetic structure of 122 specimens in 7 populations from the Colombian Atlantic coast. Assuming that all loci were in Hardy-Weinberg equilibrium, diversity statistics and analyses were performed. The average number of amplified fragments for each primer was 8.3, and the size of these fragments ranged from 350 to 3600 bp. The expected average heterozygosity was 0.358 ± 0.103. The genetic heterogeneity among the populations studied was small (GST = 0.05 ± 0.01); meanwhile, the gene flow estimates (Nm = 7.32 ± 1.35) were high. In an identical way, the Nei's genetic distances obtained yielded very small values amongst the populations that were studied in this Colombian region. Furthermore, a spatial autocorrelation analysis with Moran's I index revealed a very weak, or inexistent, spatial genetic structure among these populations. The comparison of these results with those performed for other markers (isoenzymes and microsatellites) in populations of this same mosquito from the Colombian Atlantic coast was discussed. The results of our RAPD analysis showed scarce genetic differentiation among the mosquito populations on the Colombian Atlantic coast, which was probably determined by high gene flow levels.

[A multicentre epilepsy registry in Mexico]. / Registro multicéntrico de epilepsia en México.

INTRODUCTION: The National Epilepsy Registry in Mexico was carried out, from March 2021 to December 2022, in public hospitals of the Priority Epilepsy Program 'PPE', with the aim of describing the current situation in our pediatric and adult population. PATIENTS AND METHODS: Observational, cross-sectional, multicenter study. We used a database, according to classifications of the International League Against Epilepsy (ILAE) 2017. Patients of all ages were included, with a diagnosis of epilepsy according to the practical clinical definition ILAE 2014. RESULTS: We registered 10,852 patients, 5,495 men (50.6%) and 5,357 women (49.4%). Family history of epilepsy in 1,714 patients (15.8%), febrile seizures in 987 (9.1%). Type of seizure: 5,542 (51.1%) presented focal onset, of which 1,889 (34.1%) evolved to bilateral tonic-clonic seizures; generalized onset 4,861 (44.8%), unknown 33 (3.1%) and unclassified 115 (1.1%). Almost half had unknown etiology and 40% were structural, of which hypoxic ischemic encephalopathy was the most frequent (21.6%) and neurocysticercosis was 1%. Comorbidities appeared in 6,326 patients (58.3%). Anti-seizure medications (ASM) were used in 96.4% patients, mainly valproate. Status epilepticus was found in 1,383 patients (12.7%) and drug-resistant epilepsy in 18.9%. Paraclinical studies: 79.3% with at least one electroencephalogram and 76.9% with a neuroimaging study. Epilepsy surgery occurred in 275 patients (2.5%). CONCLUSIONS: Despite the efforts of the Pan American Health Organization in its Strategy and Action Plan on epilepsy, diagnostic technologies and ASM supply are still lagging behind.

TITLE: Registro multicéntrico de epilepsia en México.Introducción. Se realizó el Registro Nacional de Epilepsia en México, de marzo de 2021 a diciembre de 2022, en hospitales del sector público del Programa Prioritario de Epilepsia, para conocer la situación actual en población pediátrica y adulta. Pacientes y métodos. Es un estudio observacional, transversal y multicéntrico. Se utilizó una base de datos, acorde con las clasificaciones de la Liga Internacional Contra la Epilepsia (ILAE) de 2017. Se incluyó a pacientes de todas las edades, con diagnóstico de epilepsia según la definición clínica práctica de la ILAE de 2014. Resultados. Se registró a 10.852 pacientes, 5.495 hombres (50,6%) y 5.357 mujeres (49,4%). Había antecedente familiar de epilepsia en 1.714 pacientes (15,8%) y crisis febriles en 987 (9,1%). Los tipos de crisis eran: 5.542 (51,1%) de inicio focal, de las que 1.889 (34,1%) evolucionaban a bilateral tonicoclónica; 4.861 (44,8%) de inicio generalizado; 33 (3,1%) de inicio desconocido; y 115 (1,1%) no clasificadas. Casi la mitad tuvo etiología desconocida y el 40% fueron estructurales; de ellas, la encefalopatía hipóxico-isquémica fue la más frecuente (21,6%) y la neurocisticercosis fue el 1%. Las comorbilidades aparecieron en 6.326 pacientes (58,3%). El 96,4% fueron tratados con fármacos anticrisis epilépticas (FACE), principalmente ácido valproico. El estado epiléptico se encontró en 1.383 pacientes (12,7%), y la farmacorresistencia, en 18,9%. Respecto a los estudios paraclínicos, al 79,3% se le realizó al menos un electroencefalograma, y al 76,9%, un estudio de neuroimagen. Se realizó cirugía de epilepsia a 275 pacientes (2,5%). Conclusiones. A pesar del esfuerzo de la Organización Panamericana de la Salud en su Estrategia y Plan de Acción sobre la Epilepsia, las tecnologías diagnósticas y el abasto de los FACE aún se encuentran rezagados.

Antioxidant activity of topiramate: an antiepileptic agent.

A number of experimental and clinical reports suggest the involvement of oxidative stress in pathophysiology of epilepsy. Topiramate, a new antiepileptic drug, induces antioxidant effect in epileptic animals. However, to date, no further studies appear to be carried out in order to demonstrate the ability of topiramate to act as antioxidant. Therefore, the objective of this work was to evaluate the in vitro superoxide (O2(·-)), hydroxyl radical (OH·), hypochlorous acid (HOCl), hydrogen peroxide (H2O2), singlet oxygen ((1)O2) and peroxynitrite (ONOO(-)) scavenging capacity of topiramate in comparison with reference compounds. In addition, we investigated the possible antitumour activity of this compound in some cancer cell lines. Topiramate displays a scavenging capacity compared to the reference compound, with the exception of ONOO(-), although it was less efficient than nordihydroguaiaretic acid, dimethylthiourea, ascorbic acid, sodium pyruvate and glutathione for O2(·-), OH·, HOCl, H2O2 and (1)O2(P < 0.0001), respectively, and not induced significant growth inhibition in cancer cell lines. The direct antioxidant properties of topiramate could explain the neuroprotective effects attributed to this compound and suggest its use as chemopreventive agent in a future.

How molecular diagnosis can change allergen-specific immunotherapy prescription in a complex pollen area.

BACKGROUND: The identification of disease-eliciting allergens is a prerequisite for accurate prescription of allergen-specific immunotherapy (SIT). The aim of this study was to determine whether molecular diagnosis (MD) may change indication and allergen prescription of SIT. METHODS: A total of 141 patients with allergic rhinoconjunctivitis and/or asthma sensitized to pollen with or without concomitant food allergy were included. Skin prick testing with a panel of aeroallergens and a microarray-based panel of allergens (ISAC(®); Phadia, Sweden) was performed in all patients. Prior to learning the results of molecular diagnosis, three of the authors reached a consensus on the indication of SIT and use of allergens following EAACI recommendations, basing their judgment on clinical history and skin prick test results before and after obtaining the ISAC results. The agreement coefficient (kappa index) was used to analyze the results. RESULTS: Fifty-nine percent of the patients were women with a mean age of 31 ± 13.63. Agreement in SIT indication before and after ISAC(®) results was found in only 62 (46%) patients (kappa = 0.1057 ± 0.0413). Concerning allergens used in the most common prescriptions before and after MD results, we obtained the following results: κ = 0.117 ± 0.0825 for grass; κ = 0.1624 ± 0.0639 for olive; κ = 0.0505 ± 0.0548 for olive and grass; κ = 0.1711 ± 0.0471 for grass and cypress; κ = 0.1897 ± 0.0493 for grass and London plane; κ = 1 ± 0.0842 for olive and cypress, and κ = 0.3586 ± 0.0798 for other combinations. CONCLUSIONS: There was very low agreement concerning indication and use of allergens for SIT before and after performing MD. This discrepancy emphasizes the usefulness of MD, at least in areas of complex sensitization to pollen, in determining correct indication of SIT.

Cardiogenic shock: management of right ventricular infarction shock.

Right ventricular infarction is a not uncommon cause of cardiogenic shock, whose frecuency is variable and could be underestimated. Although left ventricular myocardial management is well defined in the right ventricular infarction are few studies with low level of evidence, to establish definitive guidelines. It is assumed that the treatment is similar to that of the left ventricle, although there are some differences. The axis of the therapeutic management, as well as the left ventricle infarction, is based on early myocardial reperfusion, particularly through percutaneous coronary interventionism. Throm-bolysis is an option, especially after an increase in systemic blood pressure using vasoactive drugs such as norepinephrine. The preload optimization by volume administration during resuscitation of shock is useful, but it must be with caution. The use of levosimendan could be potentially beneficial option. On the neurohormonal modulation of systemic inflammatory response produced after the cardiogenic shock (CS), the use of ACE inhibitors and beta-blockers is controversial.

[Intraabdominal and thoracic pressure in critically ill patients with suspected intraabdominal hypertension]. / Presión intraabdominal y torácica en pacientes críticos con sospecha de hipertensión intraabdominal.

OBJECTIVE: To study the correlation between intraabdominal and intrathoracic pressure in patients with suspected intraabdominal hypertension. DESIGN: A prospective, observational cohort study. SETTING: Polyvalent intensive care unit of a University hospital. PATIENTS: Twenty-seven medical-surgical patient dependent upon controlled mechanical ventilation due to acute respiratory failure and with several risk factors for intraabdominal hypertension (IAH). MAIN VARIABLES: Intraabdominal (IAP), esophageal (Peso) and airways pressure were measured under static (st) and dynamic (dyn) conditions. Respiratory system (Crs), lung (Cl) and chest wall compliance (Ccw)were calculated. RESULTS: In 10 patients IAP > 12 mmHg (IAH, IAPst, 14 ± 2 [12-21] mmHg), while in the rest the pressure proved normal (n = 17; IAPst, 8 ± 2 [3-11] mmHg). Peso st was 11 ± 5 (2-27) and Peso dyn 7 ± 4 (2-24) cmH2O. Depending on the presence or absence of IAH, Peso st was 9 ± 4 vs 7 ± 3 cmH2O (p = 0.2) and Peso dyn 6 ± 2 vs 4 ± 3 cmH2O (p = 0.3), respectively. The correlation between Peso st and dyn with IAPst was 0.5 (p= 0.003) and 0.4 (p = 0.03), respectively. The compliance components were decreased (Crs, 31 ± 8; Cl, 52 ± 22 and Ccw, 105 ± 50 ml/cmH2O); Ccw was significantly lower in patients with IAH (81 ± 31 vs 118 ± 55 ml/cmH2O; p = 0.02). The correlation coefficient between IAPst and Ccw was -0.7 (p < 0.001), and -0.5 (p = 0.002) with respect to Crs. CONCLUSIONS: A stiffer chest wall was observed in patients with IAH. In patients with risk factors for IAH, pressures in these compartments were highly variable.

SARS-CoV-2 induces mitochondrial dysfunction and cell death by oxidative stress/inflammation in leukocytes of COVID-19 patients.

The inflammation and activation of the immune system induced by SARS-CoV-2 are mediated by a pro-oxidant microenvironment that can induce cytotoxic effects that enhance tissue damage, favoring organic deterioration. We investigated whether the induction of oxidative stress and inflammation by COVID-19 infection could inhibit mitochondrial function and cause cellular damage in leukocytes. We evaluated levels of oxidative/inflammation markers and their correlation with mitochondrial function and leukocyte cell death in COVID-19 patients at two moments: viremia and severe sepsis with multi-organ failure. COVID-19 induces increased oxidative stress and inflammation markers that activate cellular damage processes. In the viremia stage, an increase in peroxide, nitric oxide, carbonylated proteins, and IL-6 was observed, which was correlated with a marked inhibition of mitochondrial function, decreased cell viability, early apoptosis, necrosis, and leukocytes-reactivity. The severe sepsis stage with multi-organ failure also showed a further increase in levels of peroxide, carbonylated proteins, and IL-6, with a slight decrease in nitric oxide. This oxidative process and inflammation were correlated with less inhibition of mitochondrial function, decreased cell viability and an increase in late apoptosis, and morphology changes evidencing damage in the leukocytes. SARS-CoV-2 induced damage promotes levels of oxidative stress and inflammation markers and mitochondrial dysfunction that potentiate morphological changes and cell death in leukocytes. These processes explain the rapid changes in the immune system, and that present an initial over-activation and early massive death due to SARS-CoV-2 infection, promoting endothelial-alveolar damage that would cause multi-organ failure, sustained by oxidative stress and inflammation.

Molecular phylogenetics and phylogeography of the white-fronted capuchin (Cebus albifrons; Cebidae, Primates) by means of mtCOII gene sequences.

A total of 696 base pairs (bp) of the mitochondrial COII gene were sequenced from 118 individuals of Cebus albifrons (plus an individual of Cebus olivaceus) sampled from diverse geographical areas of Colombia, Peru, Ecuador and Brazil. These animals represented all of the C. albifrons's taxa described by Hershkovitz (1949) in Colombia and Peru (10 out of 13 subspecies are described by this author). The sequences analyzed demonstrate the existence of three well defined groups in northern Colombia (trans-Andean): malitosus, versicolor-pleei-cesarae and leucocephalus. They arose from at least, three distinct migrations from different Amazonian groups. Five different Amazonian and Eastern Llanos C. albifrons's groups (I, II, III, IV, and V) were also found. In many Amazonian localities, some of these groups live in sympatry probably by secondary expansion after their respective formations. Amazonian group I is closely related to the versicolor-pleei-cesarae group, malitosus is closely related to Amazonian group V, while leucocephalus is closely related to Amazonian group IV. Nevertheless, our genetic analysis could not resolve the genetic relationships among the main C. albifrons groups. The ρ-statistic applied to the median-joining network yielded that the major part of the temporal splits estimated occurred in the Pleistocene, reinforcing the importance of the Pleistocene refugia during the evolution of C. albifrons.

Fluctuation-induced current from freestanding graphene.

At room temperature, micron-sized sheets of freestanding graphene are in constant motion, even in the presence of an applied bias voltage. We quantify the out-of-plane movement by collecting the displacement current using a nearby small-area metal electrode and present an Ito-Langevin model for the motion coupled to a circuit containing diodes. Numerical simulations show that the system reaches thermal equilibrium and the average rates of heat and work provided by stochastic thermodynamics tend quickly to zero. However, there is power dissipated by the load resistor, and its time average is exactly equal to the power supplied by the thermal bath. The exact power formula is similar to Nyquist's noise power formula, except that the rate of change of diode resistance significantly boosts the output power, and the movement of the graphene shifts the power spectrum to lower frequencies. We have calculated the equilibrium average of the power by asymptotic and numerical methods. Excellent agreement is found between experiment and theory.

Bifurcation analysis and phase diagram of a spin-string model with buckled states.

We analyze a one-dimensional spin-string model, in which string oscillators are linearly coupled to their two nearest neighbors and to Ising spins representing internal degrees of freedom. String-spin coupling induces a long-range ferromagnetic interaction among spins that competes with a spin-spin antiferromagnetic coupling. As a consequence, the complex phase diagram of the system exhibits different flat rippled and buckled states, with first or second order transition lines between states. This complexity translates to the two-dimensional version of the model, whose numerical solution has been recently used to explain qualitatively the rippled to buckled transition observed in scanning tunneling microscopy experiments with suspended graphene sheets. Here we describe in detail the phase diagram of the simpler one-dimensional model and phase stability using bifurcation theory. This gives additional insight into the physical mechanisms underlying the different phases and the behavior observed in experiments.

Genetic Relationships and Spatial Genetic Structure Among Populations of Rhodnius prolixus (Hemiptera: Reduviidae) in Colombia and Venezuela Based on Mitochondrial Cytochrome-b Sequences.

One hundred twenty Rhodnius prolixus (Stal) (Hemiptera: Reduviidae) specimens from 6 Colombian Departments and 1 Venezuelan State had 594-bp of the mitochondrial cytochrome-b gene sequenced to improve the understanding of evolutionary processes that shape the main vector of Chagas disease. The levels of genetic diversity for this species were low-medium with reference to other bugs. The genetic heterogeneity among the populations was very limited which means there has been extensive gene flow and/or very recent split processes. The overall sample as well as some individual populations showed evidence of recent population expansions (with the exception of Arauca, which yielded evidence of a bottleneck for a mismatch distribution). This expansion (11,000 or 2000-25,000 year ago depending of two procedures employed) coincides with the ending of the last intense glacial conditions during the Pleistocene and the beginning of the Holocene that had a warmer and wetter climate. Some of our autocorrelation analyses (AIDA and Genetic Landscape Interpolation Analysis) indicated local patches of high genetic similarity but no globally significant spatial structure. We did show an original haplotype distributed throughout the entirety of the geographical area studied.

First report of major histocompatibility complex class II loci from the Amazon pink river dolphin (genus Inia).

We report the first major histocompatibility complex (MHC) DQB1 sequences for the two species of pink river dolphins (Inia geoffrensis and Inia boliviensis) inhabiting the Amazon and Orinoco River basins. These sequences were found to be polymorphic within the Inia genus and showed shared homology with cetacean DQB-1 sequences, especially, those of the Monodontidae and Phocoenidae. On the other hand, these sequences were shown to be divergent from those described for other riverine dolphin species, such as Lipotes vexillifer, the Chinese river dolphin. Two main conclusions can be drawn from our results: 1) the Mhc DQB1 sequences seem to evolve more rapidly than other nuclear sequences in cetaceans, and 2) differential positive selective pressures acting on these genes cause concomitant divergent evolutionary histories that derive phylogenetic reconstructions that could be inconsistent with widely accepted intertaxa evolutionary relationships elucidated with other molecular markers subjected to a neutral dynamics.

Genetic structure of the genera Psorophora (Diptera: Culicidae) in Columbian and North American populations using isoenzymes and ITS2 sequences.

Two, a priori, Psorophora columbiae and one, a priori, Ps. toltecum populations from Colombia were studied by means of eleven isoenzyme loci. The levels of genetic diversity, Hardy-Weinberg equilibrium, gene flow estimates, isolation by distance and genetic relationships among these three populations were studied and the results were as follows: 1. The gene diversity levels were high as well as very similar among the three populations indicating no differences between them. 2. Within each population and from a hierarchical standpoint several loci were not in Hardy-Weinberg equilibrium simultaneously by excess and defect of heterozygous. This could reflect that several natural selection forces are acting upon these mosquito populations. 3. The gene flow estimate for these populations showed the existence of this event between them. This agrees quite well with the fact that the three populations really belong to a single species. In addition, maximum parsimony analyses with 16 isoenzyme for several individuals from four Colombian and two United States Psorophora populations showed that effectively only one species was present in the Colombian area surveyed, and that this species is Ps. columbiae, which hardly contrast with that previously suggested by other authors.