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1.
Artigo em Inglês | MEDLINE | ID: mdl-38587576

RESUMO

BACKGROUND: The immediate impact of catheter ablation on left atrial mechanical function and the timeline for its recovery in patients undergoing ablation for atrial fibrillation (AF) remain uncertain. The mechanical function response to catheter ablation in patients with different AF types is poorly understood. METHODS: A total of 113 AF patients were included in this retrospective study. Each patient had three magnetic resonance imaging (MRI) studies in sinus rhythm: one pre-ablation, one immediate post-ablation (within 2 days after ablation), and one post-ablation follow-up MRI (≤ 3 months). We used feature tracking in the MRI cine images to determine peak longitudinal atrial strain (PLAS). We evaluated the change in strain from pre-ablation, immediately after ablation to post-ablation follow-up in a short-term study (< 50 days) and a 3-month study (3 months after ablation). RESULTS: The PLAS exhibited a notable reduction immediately after ablation, compared to both pre-ablation levels and those observed in follow-up studies conducted at short-term (11.1 ± 9.0 days) and 3-month (69.6 ± 39.6 days) intervals. However, there was no difference between follow-up and pre-ablation PLAS. The PLAS returned to 95% pre-ablation level within 10 days. Paroxysmal AF patients had significantly higher pre-ablation PLAS than persistent AF patients in pre-ablation MRIs. Both type AF patients had significantly lower immediate post-ablation PLAS compared with pre-ablation and post-ablation PLAS. CONCLUSION: The present study suggested a significant drop in PLAS immediately after ablation. Left atrial mechanical function recovered within 10 days after ablation. The drop in PLAS did not show a substantial difference between paroxysmal and persistent AF patients.

2.
Ecol Lett ; 27(4): e14426, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38603592

RESUMO

While natural communities can contain hundreds of species, modern coexistence theory focuses primarily on species pairs. Alternatively, the structural stability approach considers the feasibility of equilibria, gaining scalability to larger communities but sacrificing information about dynamic stability. Three-species competitive communities are a bridge to more-diverse communities. They display novel phenomena while remaining amenable to mathematical analysis, but remain incompletely understood. Here, we combine these approaches to identify the key quantities that determine three-species competition outcomes. We show that pairwise niche overlap and fitness differences are insufficient to completely characterize competitive outcomes, which requires a strictly triplet-wise quantity: cyclic asymmetry, which underlies intransitivity. Low pairwise niche overlap stabilizes the triplet, while high fitness differences promote competitive exclusion. The effect of cyclic asymmetry on stability is complex and depends on pairwise niche overlap. In summary, we elucidate how pairwise niche overlap, fitness differences and cyclic asymmetry determine three-species competition outcomes.


Assuntos
Ecossistema , Modelos Biológicos
3.
Exp Parasitol ; 259: 108713, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38350522

RESUMO

The recurrence of visceral leishmaniasis (VL), also called kala-azar (KA), in endemic regions of tropical countries like India, is primarily attributed to asymptomatic VL, post-kala azar dermal leishmaniasis (PKDL), and human immunodeficiency virus (HIV) co-infection. To effectively manage VL cases and elimination targets, an early and rapid diagnosis as well as accurate field surveillance is highly essential. The traditional sampling methods like bone marrow (BM), spleen, and lymph node (LN) tissue aspirations are invasive, painful, tedious, and prone to nosocomial infections, require skilled persons and hospital facilities, and are not feasible in rural areas. Therefore, there is an urgent requirement for the adoption of a patient-friendly, non-invasive, non-hospitalized sampling procedure that ensures an effective VL diagnosis. This review aims to meticulously evaluate the most recent scientific research that focuses on the precision, feasibility, and applicability of non-invasive sampling (NIS) and techniques for the diagnosis and test of cure of VL, particularly in resource-limited settings. Apart from that, the non-invasive techniques (NIT) that have shown promising results while monitoring VL treatment response and relapse are also reviewed. The limitations associated with NIT and possible improvements in this regard are discussed as well to improve the diagnosis and management of VL.


Assuntos
Leishmaniose Cutânea , Leishmaniose Visceral , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , Leishmaniose Cutânea/diagnóstico , Índia/epidemiologia , Recidiva
4.
Cell Rep Methods ; 4(1): 100689, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38228151

RESUMO

In early neurodevelopment, the central nervous system is established through the coordination of various neural organizers directing tissue patterning and cell differentiation. Better recapitulation of morphogen gradient production and signaling will be crucial for establishing improved developmental models of the brain in vitro. Here, we developed a method by assembling polydimethylsiloxane devices capable of generating a sustained chemical gradient to produce patterned brain organoids, which we termed morphogen-gradient-induced brain organoids (MIBOs). At 3.5 weeks, MIBOs replicated dorsal-ventral patterning observed in the ganglionic eminences (GE). Analysis of mature MIBOs through single-cell RNA sequencing revealed distinct dorsal GE-derived CALB2+ interneurons, medium spiny neurons, and medial GE-derived cell types. Finally, we demonstrate long-term culturing capabilities with MIBOs maintaining stable neural activity in cultures grown up to 5.5 months. MIBOs demonstrate a versatile approach for generating spatially patterned brain organoids for embryonic development and disease modeling.


Assuntos
Encéfalo , Eminência Ganglionar , Feminino , Gravidez , Humanos , Interneurônios , Diferenciação Celular , Organoides
5.
bioRxiv ; 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38260630

RESUMO

Diverse eukaryotic cells assemble microtubule networks that vary in structure and composition. While we understand how cells build microtubule networks with specialized functions, we do not know how microtubule networks diversify across deep evolutionary timescales. This problem has remained unresolved because most organisms use shared pools of tubulins for multiple networks, making it impossible to trace the evolution of any single network. In contrast, the amoeboflagellate Naegleria uses distinct tubulin genes to build distinct microtubule networks: while Naegleria builds flagella from conserved tubulins during differentiation, it uses divergent tubulins to build its mitotic spindle. This genetic separation makes for an internally controlled system to study independent microtubule networks in a single organismal and genomic context. To explore the evolution of these microtubule networks, we identified conserved microtubule binding proteins and used transcriptional profiling of mitosis and differentiation to determine which are upregulated during the assembly of each network. Surprisingly, most microtubule binding proteins are upregulated during only one process, suggesting that Naegleria uses distinct component pools to specialize its microtubule networks. Furthermore, the divergent residues of mitotic tubulins tend to fall within the binding sites of differentiation-specific microtubule regulators, suggesting that interactions between microtubules and their binding proteins constrain tubulin sequence diversification. We therefore propose a model for cytoskeletal evolution in which pools of microtubule network components constrain and guide the diversification of the entire network, so that the evolution of tubulin is inextricably linked to that of its binding partners.

6.
Ann Rev Mar Sci ; 16: 513-536, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-37625127

RESUMO

For decades, multiple-driver/stressor research has examined interactions among drivers that will undergo large changes in the future: temperature, pH, nutrients, oxygen, pathogens, and more. However, the most commonly used experimental designs-present-versus-future and ANOVA-fail to contribute to general understanding or predictive power. Linking experimental design to process-based mathematical models would help us predict how ecosystems will behave in novel environmental conditions. We review a range of experimental designs and assess the best experimental path toward a predictive ecology. Full factorial response surface, fractional factorial, quadratic response surface, custom, space-filling, and especially optimal and sequential/adaptive designs can help us achieve more valuable scientific goals. Experiments using these designs are challenging to perform with long-lived organisms or at the community and ecosystem levels. But they remain our most promising path toward linking experiments and theory in multiple-driver research and making accurate, useful predictions.


Assuntos
Ecologia , Ecossistema , Nutrientes , Oxigênio , Temperatura
7.
Exp Parasitol ; 257: 108688, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38142765

RESUMO

The recent increase in the drug (liposomal amphotericin-B) unresponsive cases becomes hostile for the visceral leishmaniasis (VL) elimination target. The quest for new antileishmanial drugs is on the way and may demand more time. Meanwhile, drug repurposing is a quite promising option to explore further. We made such an attempt with thioridazine (TRZ), a first-line antipsychotic drug, which was reported for antimicrobial activity. In this study, we evaluated the drug activity of TRZ against amphotericin-B (Amp-B) sensitive and unresponsive Leishmania donovani promastigotes, as well as intracellular amastigotes (drug sensitive). We observed a potent antileishmanial activity of TRZ with significantly low half maximal inhibitory concentrations (IC50) on both the variants of promastigotes (0.61 ± 0.15 µM). These concentrations are comparable to the previously reported IC50 concentration of the current antileishmanial drug (Amp-B) against L. donovani. Light microscopy reveals the perturbations in promastigote morphology upon TRZ treatment. The in vitro studies on human macrophage cell lines determine the 50% cytotoxicity concentration (CC50) of TRZ on host cells as 20.046 µM and a half maximal effective concentration (EC50) as 0.91 µM during L. donovani infection, in turn selectivity index (SI) was calculated as 22.03 µM. Altogether, the results demonstrate that TRZ has the potential for drug repurposing and further studies on animal models could provide better insights for VL treatment.


Assuntos
Antiprotozoários , Leishmania donovani , Leishmaniose Visceral , Animais , Humanos , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Tioridazina/farmacologia , Tioridazina/uso terapêutico , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico
8.
J Surg Res ; 293: 196-203, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37778087

RESUMO

INTRODUCTION: Despite advances in antiarrhythmia therapies, ventricular tachycardia (VT) is a leading cause of sudden cardiac death. Investigation into the characteristics and new treatments for this arrhythmia is required to improve outcomes and a reproducible model of VT would be useful in these endeavors. We therefore created a canine model of ischemia-induced VT. MATERIALS AND METHODS: A pacing lead was implanted in the right ventricle in canines (n = 13) and the left anterior descending artery was occluded in two locations for 2 h and subsequently released to create an ischemia-reperfusion injury. In the 10 dogs that survived the first 48 h following the initial study, a terminal study was conducted 4-7 d later and VT was induced using premature stimulation or burst pacing through the right ventricle lead. The arrhythmia was terminated using either antitachycardia pacing or a defibrillatory shock. Multiple inductions into sustained VT were attempted. RESULTS: Sustained VT was induced in eight of 10 dogs with an average cycle length of 335 ± 70 bpm. Multiple episodes of VT were induced. Episodes of VT exhibited different electrocardiogram morphologies and cycle lengths in individual animals. CONCLUSIONS: This canine model provides a consistent technique for inducing multiple episodes of sustained VT. It may be useful for investigating VT mechanisms and testing novel therapeutics and treatments for patients with VT.


Assuntos
Estimulação Cardíaca Artificial , Taquicardia Ventricular , Humanos , Cães , Animais , Estimulação Cardíaca Artificial/efeitos adversos , Estimulação Cardíaca Artificial/métodos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/terapia , Ventrículos do Coração , Eletrocardiografia/efeitos adversos , Isquemia/complicações
9.
J Cardiovasc Electrophysiol ; 35(3): 538-546, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38131368

RESUMO

Atrial fibrillation (AF) is significantly associated with morbidity and mortality and erodes the quality and quantity of life. It is standard of care to treat patients with AF and an increased risk of stroke with oral anticoagulation therapy, but the more daunting question many clinicians face is whether to pursue a "rate-only" or "rhythm" control strategy. Historical studies over the years have sought to answer this question but have found no significant difference in major clinical outcomes between the two strategies. There are opportunities based on new data to improve the natural history of the disease. The EAST AFnet trial for the first time revealed a significant morbidity and mortality advantage to rhythm control therapy when performed early in the disease process of AF and in the setting of comprehensive medical management that was maintained. The CABANA trial clearly demonstrated that catheter ablation was a more effective long-term treatment of AF in general and significantly lowers risk of AF progression compared to medical therapy. Like multiple prior trials of rhythm management strategies, when rhythm control was effective in these trials, independent of therapy assignment, there was a significantly lower risk of adverse outcomes and death. These contemporary data provide optimism that the pervasive mortality risk in patients with AF observed over the past 50 years may be improved by the timing, use, and efficacy of use of therapeutic interventions.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Fibrilação Atrial/tratamento farmacológico , Antiarrítmicos/uso terapêutico , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/prevenção & controle , Acidente Vascular Cerebral/etiologia , Ablação por Cateter/efeitos adversos , Resultado do Tratamento
10.
Indian J Community Med ; 48(5): 790-793, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37970162

RESUMO

During the COVID-19 pandemic, precautionary guidelines to shut down non-essential services had an impact on the pattern of hospital trauma admissions. We compared the trauma cases handled in our hospital from 24th March 2020 to 30th November 2020 during the restricted movement period with statistics from 2019. The objectives of this study is to assess the prevalence of trauma during lockdown and restricted movement phase of COVID-19 pandemic and to analyze the epidemiology factor associated with trauma in pre COVID-19 and COVID-19 era in a tertiary care hospital of National importance in central India. This retrospective record-based study was done to analyze the profile of injured trauma patients presented to trauma and emergency center of tertiary care center of national importance from March 24 to June 30, 2020 (lockdown phase) and 1st July to 30th November (post-lockdown phase) of 2020. Results were compared with data from the year 2019. Total 621 trauma patients were managed during various restricted phases of the COVID-19 pandemic (March 2020 - November 2020). Out of which 128 admissions were in the strict lockdown phase (March-May 2020) while 493 presented after lockdown during the restricted movement phase. Both during and after a strict lockdown, road traffic accidents are significantly reduced. In contrast, assaults and household injuries were significantly higher. During the post-lockdown phase of 2020, self-falls increased significantly in both phases compared to the year 2019. There was a significant decrease in trauma admissions in lockdown phase due to decreased vehicular accident but increase in household injury due increased activities inside home. To determine the readiness to deal with future situations similar to these, we look at the behavioral changes in our patient population during the COVID-19 pandemic.

11.
J Lab Physicians ; 15(4): 583-589, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37780888

RESUMO

Introduction Fetal hemoglobin (HbF) levels play significant role in lowering down the morbidity and mortality in sickle cell disease (SCD) patients. Coinheritance of heme oxygenase-1 (HMOX1) rs2071746:A > T polymorphism may contribute to variable HbF levels in Indian SCD patients. Objective This study was aimed to evaluate the role of HMOX1 polymorphism and its impact on HbF level in Indian SCD patients. Materials and Methods One-hundred twenty confirmed cases of SCD and 50 healthy controls were recruited. Their mean age was 11.5 ± 8.6 years (range: 3-23 years). Quantification of Hb, HbA2, HbF, and HbS was done by capillary zone electrophoresis. Allele-specific polymerase chain reaction was used to genotype HMOX1 (rs2071746:A > T) gene polymorphism. Results Out of the 120 cases of SCD, 65 were hemoglobin sickle-shaped (HbSS) and 55 were sickle-beta thalassemia (Sß). Out of 65 HbSS patients, 29 (44.6%) were heterozygous (AT), 20 (30.76%) were homozygous (TT), and 16 (24.61%) were found wild-type (AA) genotype. Out of 55 Sß, 22 (40%) were heterozygous, 18 (32%) were homozygous and 15 (28%) were wild-type. Patients carrying HMOX1 (rs2071746:A > T), AT, and TT genotypes had less anemia, painful crisis, splenomegaly, hepatomegaly, jaundice, and blood transfusion. HbF level was found higher in TT genotype (in HbSS the HbF levels was 25.1 ± 4.4; in sickle-beta thalassemia the HbF levels was 36.1 ± 4.7) than wild-type(AA) and was statistically significant ( p -value <0.001). Conclusion The TT genotype of the rs2071746:A > T polymorphism was associated with increased levels of Hb F ( p < 0.001). It can serve as a HbF modifier in Indian sickle cell diseases patients.

12.
Indian J Hematol Blood Transfus ; 39(4): 565-571, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37786815

RESUMO

Hemolysis, a crucial feature of Sickle cell disease (SCD), is a key player for cellular activation leading to various complications including thrombosis. In response to hemolysis, platelets get activated and release components that are necessary for further platelet activation and aggregation. Thus, it is believed that platelets contribute to the development of thrombotic complications. Platelets in SCD are expected to be affected due to common cause of hemolysis. To measure the surface markers of platelets including P-Selectin, Phosphatidyl Serine and integrin αIIbß3 in SCD patients and healthy controls in order to understand the status of the platelets in SCD. To measure the surface markers of activated platelets using flow cytometry. Since mitochondria and calcium play an important role in cellular functions, the mitochondrial membrane potential and calcium content of platelets in SCD were also evaluated using flow cytometry. In the present study, we have observed significant increase of calcium level in SCD platelets. Further, the loss of mitochondrial membrane potential in SCD platelets was found to be significantly higher when compared to platelets of healthy controls. Though the surface markers of activated platelets in SCD remain unchanged, increased level of calcium and mitochondrial membrane potential loss suggest that the platelets in SCD are more prone to become activated. In order to understand the status of the platelets in SCD, apart from the surface markers, it is also important to assess the calcium levels and mitochondrial membrane potential of platelets.

13.
medRxiv ; 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37649910

RESUMO

Artificial intelligence - machine learning (AI-ML) is a computational technique that has been demonstrated to be able to extract meaningful clinical information from diagnostic data that are not available using either human interpretation or more simple analysis methods. Recent developments have shown that AI-ML approaches applied to ECGs can accurately predict different patient characteristics and pathologies not detectable by expert physician readers. There is an extensive body of literature surrounding the use of AI-ML in other fields, which has given rise to an array of predefined open-source AI-ML architectures which can be translated to new problems in an "off-the-shelf" manner. Applying "off-the-shelf" AI-ML architectures to ECG-based datasets opens the door for rapid development and identification of previously unknown disease biomarkers. Despite the excellent opportunity, the ideal open-source AI-ML architecture for ECG related problems is not known. Furthermore, there has been limited investigation on how and when these AI-ML approaches fail and possible bias or disparities associated with particular network architectures. In this study, we aimed to: (1) determine if open-source, "off-the-shelf" AI-ML architectures could be trained to classify low LVEF from ECGs, (2) assess the accuracy of different AI-ML architectures compared to each other, and (3) to identify which, if any, patient characteristics are associated with poor AI-ML performance.

14.
Phys Chem Chem Phys ; 25(33): 22040-22054, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37555468

RESUMO

The present work demonstrates the effect of temperature-dependent surface modification (SM) treatment and its influence in broadening the catalysis regime with Pd-TiO2 catalysts prepared by various methods. Due to SM induced changes, a shift in the onset of CO oxidation activity as well as broadening of the oxidation catalysis regime by 30 to 65 K to lower temperatures is observed compared to the temperature required for virgin counterparts. SM carried out at 523 K for PdPhoto-TiO2 exhibits the lowest onset (10% CO2 production - T10) and T100 for CO oxidation at 360 and 392 K, respectively, while its virgin counterpart shows T10 and T100 at 393 and 433 K, respectively. The SMd Pd-TiO2 catalysts were investigated using X-ray photoelectron spectroscopy (XPS), ultra-violet photoelectron spectroscopy (UPS) and atomic force microscopy (AFM). It is observed that diffusion of atomic oxygen into Pd-subsurfaces leads to SM and changes the nature of the surface significantly. These changes are demonstrated by work function (ϕ), surface potential, catalytic activity, and correlation among them. UPS results demonstrate the maximum increase in ϕ by 0.5 eV for PdPhoto-TiO2 after SM, compared to all other catalysts. XPS study shows a moderate to severe change in the oxidation states of Pd due to atomic oxygen diffusion into the subsurface layers of Pd. Kelvin probe force microscopy (KPFM) study also reveals corroborating evidence that the surface potential increases linearly with increasing temperature deployed for SM up to 523 K, followed by a marginal decrease at 573 K. The ϕ measured by KPFM and UPS shows a similar trend and correlates well with the changes in catalysis observed. Our results indicate that there is a strong correlation between surface physical and chemical properties, and ϕ changes could be considered as a global marker for chemical reactivity.

15.
Micromachines (Basel) ; 14(7)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37512666

RESUMO

This paper examines the performance of a Gate-Engineered Gate-All-Around Charge Plasma Nanowire Field Effect Transistor (GAA-DMG-GS-CP NW-FET) and the implementation of a common source (CS) amplifier circuit. The proposed GAA-DMG-GS-CP NW-FET incorporates dual-material gate (DMG) and gate stack (GS) as gate engineering techniques and its analog/RF performance parameters are compared to those of the Gate-All-Around Single-Material Gate Charge Plasma Nanowire Field Effect Transistor (GAA-SMG-CP NW-FET) device. Both Gate-All-Around (GAA) devices are designed using the Silvaco TCAD tool. GAA structures have demonstrated good gate control because the gate holds the channel, which is an inherent advantage for both devices discussed herein. The charge plasma dopingless technique is used, in which the source and drain regions are formed using metal contacts and necessary work functions rather than doping. This dopingless technique eliminates the need for doping, reducing fluctuations caused by random dopants and lowering the device's thermal budget. Gate engineering techniques such as DMG and GS significantly improved the current characteristics which played a crucial role in obtaining maximum gain for circuit designs. The lookup table (LUT) approach is used in the implementation of the CS amplifier circuit with the proposed device. The transient response of the circuit is analyzed with both the device structures where the gain achieved for the CS amplifier circuit using the proposed GAA-DMG-GS-CP NW-FET is 15.06 dB. The superior performance showcased by the proposed GAA-DMG-GS-CP NW-FET device with analog, RF and circuit analysis proves its strong candidature for future nanoscale and low-power applications.

16.
Heart Rhythm O2 ; 4(4): 251-257, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37124552

RESUMO

Background: Catheter ablation is an effective treatment for atrial fibrillation (AF) but incurs significant financial costs to payers. Reducing variability may improve cost effectiveness. Objectives: We aimed to measure (1) the components of direct and indirect costs for routine AF ablation procedures, (2) the variability of those costs, and (3) the main factors driving ablation cost variability. Methods: Using data from the University of Utah Health Value Driven Outcomes system, we were able to measure direct, inflation-adjusted costs of uncomplicated, routine AF ablation to the healthcare system. Direct costs were considered costs incurred by pharmacy, disposable supplies, patient labs, implants, and other services categories (primarily anesthesia support) and indirect costs were considered within imaging, facility, and electrophysiology lab management categories. Results: A total of 910 patients with 1060 outpatient ablation encounters were included from January 1, 2013, to December 31, 2020. Disposable supplies accounted for the largest component of cost with 44.8 ± 9.7%, followed by other services (primarily anesthesia support) with 30.4 ± 7.7% and facility costs with 16.1 ± 5.6%; pharmacy, imaging, and implant costs each contributed <5%. Direct costs were larger than indirect costs (82.4 ± 5.6% vs 17.6 ± 5.6%). Multivariable regression showed that procedure operator was the primary factor associated with AF ablation overall cost (up to 12% differences depending on operator). Conclusions: Direct costs and other services (primarily anesthesia) drive the majority costs associated with AF ablations. There is significant variability in costs for these routine, uncomplicated AF ablation procedures. The procedure operator, and not patient characteristic, is the main driver for cost variability.

17.
J Cardiovasc Electrophysiol ; 34(5): 1249-1256, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37125623

RESUMO

INTRODUCTION: Antitachycardia pacing (ATP) is used to terminate ventricular tachycardia (VT) by delivering rapid, low energy pacing to the right ventricle (RV). Unfortunately, ATP is not effective against all VT episodes and can result in adverse outcomes, such as VT acceleration and degeneration into ventricular fibrillation (VF). Improving ATP is therefore desirable. Our objective was to compare the efficacy and safety of ATP delivered at the His bundle to traditional ATP. METHODS: Six dogs were anesthetized and pacing leads were implanted in the RV and His bundle. The left anterior descending artery was occluded for 2 h to create an ischemic injury. In a study 4-7 days later, a 128-electrode sock was placed snugly around the ventricles and VT was induced using rapid pacing. ATP was delivered from either the His bundle or RV lead, then attempted at the other location if unsuccessful. Success rates and instances of VT acceleration and degeneration into VF were calculated. RESULTS: We induced 83 runs of VT and attempted ATP 128 times. RV ATP was successful in 36% of attempts; His ATP was successful in 38% of attempts. RV ATP resulted in significantly more adverse outcomes. RV and His ATP induced VT acceleration in 9% and 3% of trains, respectively, and induced degeneration into VF in 5% and 1% of trains, respectively. CONCLUSION: His bundle ATP is safer, but not significantly more effective, than RV ATP.


Assuntos
Desfibriladores Implantáveis , Taquicardia Ventricular , Cães , Animais , Ventrículos do Coração , Fascículo Atrioventricular , Estimulação Cardíaca Artificial/métodos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/terapia , Fibrilação Ventricular/diagnóstico , Fibrilação Ventricular/terapia , Trifosfato de Adenosina
18.
Can J Respir Ther ; 59: 95-99, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37063456

RESUMO

Introduction: Patients with acute respiratory distress syndrome (ARDS) on mechanical ventilation often require high inspiratory pressure and positive end-expiratory pressure (PEEP). However, effective ventilation becomes difficult in cases where a large air leak develops in patients. The management of such a case requires improvisation and the adoption of special ventilation strategies. Case and outcomes: We present a case study of a burn patient with airway involvement, developing ARDS and who developed a bronchopleural fistula (BPF) leading to failure of conventional ventilation. He was managed successfully with high-frequency oscillatory ventilation (HFOV) and finally discharged. Conclusion: HFOV is a feasible option for ventilating patients with BPF when conventional ventilation fails. At a time when HFOV has largely been relegated to obsolescence, we hope to re-emphasize its relevance under particular circumstances.

19.
Food Chem Toxicol ; 176: 113788, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37075880

RESUMO

Tert-Butylhydroquinone (tBHQ), a preservative used to prevent oxidative deterioration of oil, fat, and meat products, has been linked to both chemoprotective and adverse effects. This study investigates the impact of dietary tBHQ consumption on survival, growth parameters, organ development, and gene expression in zebrafish (Danio rerio). As tBHQ activates the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2a), a zebrafish line with a mutation in the DNA-binding domain of Nrf2a was used to identify Nrf2a-dependent vs independent effects. Homozygous Nrf2a wildtype (wt) and mutant (m) larvae were fed a diet containing 5% tBHQ or a control diet. Survival and growth parameters were assessed at 15 days and at 5 months, and samples were collected for RNA sequencing at 5 months. Dietary exposure to tBHQ throughout the larval and juvenile periods negatively impacted growth and survival. RNA-seq analysis found differentially expressed genes related to growth and development and upregulation of several immune system-related pathways. The findings herein demonstrate that dietary tBHQ exposure may impair growth and survival in both Nrf2a dependent and independent manners.


Assuntos
Conservantes de Alimentos , Peixe-Zebra , Animais , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Antioxidantes/metabolismo , Exposição Dietética , Hidroquinonas/toxicidade , Expressão Gênica , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo
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