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The developed asymmetric monovalent bispecific IgG1 or Duet monoclonal antibody (Duet mAb) has two distinct fragment antigen-binding region (Fab) subunits that target two different epitope specificities sequentially or simultaneously. The design features include unique engineered disulfide bridges, knob-into-hole mutations, and kappa and lambda chains to produce Duet mAbs. These make it structurally and functionally complex, so one expects challenging developability linked to instability, degradation of products and pathways, and limited reports available. Here, we have treated the product with different sources of extreme stress over a lengthy period, including varying heat, pH, photo stress, chemical oxidative stress, accelerated stress in physiological conditions, and forced glycation conditions. The effects of different stress conditions on the product were assessed using various analytical characterization tools to measure product-related substances, post-translational modifications (PTMs), structural integrity, higher-order disulfide linkages, and biological activity. The results revealed degradation products and pathways of Duet mAb. A moderate increase in size, charge, and hydrophobic variants, PTMs, including deamidation, oxidation, isomerization, and glycation were observed, with most conditions exhibiting biological activity. In addition, the characterization of fractionated charge variants, including deamidated species, showed satisfactory biological activity. This study demonstrated the prominent stability of the Duet mAb format comparable to most marketed mAbs.
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Developing a knob-into-hole asymmetric bispecific IgG1 monoclonal antibody (mAb) poses manufacturing challenges due to the expression of chain pairing variants, also called mispaired species, in the desired product. The incorrect pairing of light and heavy chains could result in heterogeneous mispaired species of homodimers, heterodimers, light chain swapping, and low molecular weight species (LMWS). Standard chromatography, capillary electrophoretic, or spectroscopic methods poorly resolve these from the main variants. Here, we report a highly sensitive reverse-phase polyphenyl ultra-high-performance liquid chromatography (RP-UHPLC) method to accurately measure mispaired species of Duet mAb format, an asymmetric IgG1 bispecific mAb, for both process development and quality control analytical tests. Coupled with electrospray ionization mass spectrometry (ESI-MS), it enabled direct online characterization of mispaired species. This single direct assay detected diverse mispaired IgG-like species and LMWS. The method resolved eight disulfide bonds dissociated LMWS and three mispaired LMWS. It also resolved three different types of IgG-like mispaired species, including two homodimers and one heterodimer. The characterization and quantification simultaneously enabled the cell line selection that produces a lesser heterogeneity and lower levels of mispaired species with the desired correctly paired product. The biological activity assessment of samples with increased levels of these species quantified by the method exhibited a linear decline in potency with increasing levels of mispaired species in the desired product. We also demonstrated the utility of the technique for testing in-process intermediate materials to determine and assess downstream purification process capability in removing diverse mispaired IgG-like species and LMWS to a certain level during the downstream purification process. Our investigation demonstrates that adopting this method was vital in developing asymmetric bispecific mAb from the initial stage of cell line development to manufacturing process development. Therefore, this tool could be used in the control strategy to monitor and control mispaired species during manufacturing, thus improving the quality control of the final product.
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Anticuerpos Biespecíficos , Espectrometría de Masa por Ionización de Electrospray , Inmunoglobulina G/química , Cromatografía de Fase Inversa , Dominios Proteicos , Anticuerpos Biespecíficos/química , Anticuerpos Monoclonales/químicaRESUMEN
Background: Cardiac arrest (CA) is a significant public health concern. There is the high imminent mortality and survival in those who are resuscitated is substantively compromised by the post-CA syndrome (PCAS), characterized by multiorgan ischemia-reperfusion injury (IRI). The inflammatory response in PCAS is complex and involves various immune cell types, including lymphocytes and myeloid cells that have been shown to exacerbate organ IRI, such as myocardial infarction. Purinergic signaling, as regulated by CD39 and CD73, has emerged as centrally important in the context of organ-specific IRI. Hence, comprehensive understanding of such purinergic responses may be likewise imperative for improving outcomes in PCAS. Methods: We have investigated alterations of immune cell populations after CA by utilizing rodent models of PCAS. Blood and spleen were collected after CA and resuscitation and underwent flow cytometry analysis to evaluate shifts in CD3+CD4+ helper T cells, CD3+CD8a+ cytotoxic T cells, and CD4/CD8a ratios. We then examined the expression of CD39 and CD73 across diverse cell types, including myeloid cells, T lymphocytes, and B lymphocytes. Results: In both rat and mouse models, there were significant increases in the frequency of CD3+CD4+ T lymphocytes in PCAS (rat, P < 0.01; mouse, P < 0.001), with consequently elevated CD4/CD8a ratios in whole blood (both, P < 0.001). Moreover, CD39 and CD73 expression on blood leukocytes were markedly increased (rat, P < 0.05; mouse, P < 0.01 at 24h). Further analysis in the experimental mouse model revealed that CD11b+ myeloid cells, with significant increase in their population (P < 0.01), had high level of CD39 (88.80 ± 2.05 %) and increased expression of CD73 (P < 0.05). CD19+ B lymphocytes showed slight increases of CD39 (P < 0.05 at 2h) and CD73 (P < 0.05 at 2h), while, CD3+ T lymphocytes had decreased levels of them. These findings suggested a distinct patterns of expression of CD39 and CD73 in these specific immune cell populations after CA. Conclusions: These data have provided comprehensive insights into the immune response after CA, highlighting high-level expressions of CD39 and CD73 in myeloid cells.
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Paro Cardíaco , Roedores , Animales , Ratones , Ratas , Citometría de Flujo , Leucocitos , Linfocitos T Citotóxicos , 5'-Nucleotidasa/metabolismoRESUMEN
BACKGROUND: High/intermediate-risk pulmonary embolism (PE) confers increased risk of cardiovascular morbidity and mortality. International guidelines recommend the formation of a PE response team (PERT) for PE management because of the complexity of risk stratification and emerging treatment options. However, there are currently no available Australian data regarding outcomes of PE managed through a PERT. AIMS: To analyse the clinical and outcome data of patients from an Australian centre with high/intermediate-risk PE requiring PERT-guided management. METHODS: We performed a retrospective observational study of 75 consecutive patients with high/intermediate-risk PE who had PERT involvement, between August 2018 and July 2021. We recorded clinical and interventional data at the time of PERT and assessed patient outcomes up to 30 days from PERT initiation. We used unpaired t tests to compare right to left ventricular (RV/LV) ratios by computed tomography criteria or transthoracic echocardiogram (TTE) at baseline and after interventions. RESULTS: Data were available for 74 patients. Initial computed tomography pulmonary angiography RV/LV ratio was increased at 1.65 ± 0.5 and decreased to 1.30 ± 0.29 following PERT-guided interventions (P < 0.001). TTE RV/LV ratio also decreased following PERT-guided management (1.09 ± 0.19 vs 0.93 ± 0.17; P < 0.001). 20% of patients had any bleeding complication, but two-thirds were mild, not requiring intervention. All-cause mortality was 6.8%, and all occurred within the first 7 days of admission. CONCLUSION: The PERT model is feasible in a large Australian centre in managing complex and time-critical PE. Our data demonstrate outcomes comparable with existing published international PERT data. However, successful implementation at other Australian institutions may require adequate centre-specific resource availability and the presence of multispeciality input.
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OBJECTIVE: Oxygen consumption (VO2), carbon dioxide generation (VCO2), and respiratory quotient (RQ), which is the ratio of VO2 to VCO2, are critical indicators of human metabolism. To seek a link between the patient's metabolism and pathophysiology of critical illness, we investigated the correlation of these values with mortality in critical care patients. METHODS: This was a prospective, observational study conducted at a suburban, quaternary care teaching hospital. Age 18 years or older healthy volunteers and patients who underwent mechanical ventilation were enrolled. A high-fidelity automation device, which accuracy is equivalent to the gold standard Douglas Bag technique, was used to measure VO2, VCO2, and RQ at a wide range of fraction of inspired oxygen (FIO2). RESULTS: We included a total of 21 subjects including 8 post-cardiothoracic surgery patients, 7 intensive care patients, 3 patients from the emergency room, and 3 healthy volunteers. This study included 10 critical care patients, whose metabolic measurements were performed in the ER and ICU, and 6 died. VO2, VCO2, and RQ of survivors were 282 +/- 95 mL/min, 202 +/- 81 mL/min, and 0.70 +/- 0.10, and those of non-survivors were 240 +/- 87 mL/min, 140 +/- 66 mL/min, and 0.57 +/- 0.08 (p = 0.34, p = 0.10, and p < 0.01), respectively. The difference of RQ was statistically significant (p < 0.01) and it remained significant when the subjects with FIO2 < 0.5 were excluded (p < 0.05). CONCLUSIONS: Low RQ correlated with high mortality, which may potentially indicate a decompensation of the oxygen metabolism in critically ill patients.
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Pulmón , Respiración Artificial , Humanos , Adolescente , Estudios Prospectivos , Calorimetría Indirecta/métodos , Consumo de Oxígeno , Dióxido de Carbono/metabolismo , Enfermedad Crítica/terapia , OxígenoRESUMEN
INTRODUCTION: Endotracheal intubation (ETI) is a procedure that varies in difficulty because of patient characteristics and clinical conditions. Existing physical simulators do not encompass these variations. The Virtual Airway Skills Trainer for Endotracheal Intubation (VAST-ETI) was developed to provide different patient characteristics and high-fidelity haptic feedback to improve training. METHODS: We demonstrate the effectiveness of VAST-ETI as a training and evaluation tool for ETI. Construct validation was evaluated by scoring the performance of experts ( N = 15) and novices ( N = 15) on the simulator to ensure its ability to distinguish technical proficiency. Convergent and predictive validity were evaluated by performing a learning curve study, in which a group of novices ( N = 7) were trained for 2 weeks using VAST-ETI and then compared with a control group ( N = 9). RESULTS: The VAST-ETI was able to distinguish between expert and novice based on mean simulator scores ( t [88] = -6.61, P < 0.0005). When used during repeated practice, individuals demonstrated a significant increase in their score on VAST-ETI over the learning period ( F [11,220] = 7206, P < 0.001); however when compared with a control group, there was not a significant interaction effect on the simulator score. There was a significant difference between the simulator-trained and control groups ( t [12.85] = -2.258, P = 0.042) when tested in the operating room. CONCLUSIONS: Our results demonstrate the effectiveness of virtual simulation with haptic feedback for assessing performance and training of ETI. The simulator was not able to differentiate performance between more experienced trainees and experts because of limits in simulator difficulty.
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Tecnología Háptica , Intubación Intratraqueal , Humanos , Retroalimentación , Simulación por Computador , Curva de Aprendizaje , Competencia ClínicaRESUMEN
Fibrotic cataracts, posterior capsular opacification (PCO), and anterior subcapsular cataracts (ASC) are mainly attributed to the transforming growth factor-ß (TGFß)-induced epithelial-to-mesenchymal transition (EMT) of lens epithelial cells (LECs). Previous investigations from our laboratory have shown the novel role of non-canonical TGFß signaling in the progression of EMT in LECs. In this study, we have identified YAP as a critical signaling molecule involved in lens fibrosis. The observed increase in nuclear YAP in capsules of human ASC patients points toward the involvement of YAP in lens fibrosis. In addition, the immunohistochemical (IHC) analyses on ocular sections from mice that overexpress TGFß in the lens (TGFßtg) showed a co-expression of YAP and α-SMA in the fibrotic plaques when compared to wild-type littermate lenses, which do not. The incubation of rat lens explants with verteporfin, a YAP inhibitor, prevented a TGFß-induced fiber-like phenotype, α-SMA, and fibronectin expression, as well as delocalization of E-cadherin and ß-catenin. Finally, LECs co-incubated with TGFß and YAP inhibitor did not exhibit an induction in matrix metalloproteinase 2 compared to those LECs treated with TGFß alone. In conclusion, these data demonstrate that YAP is required for TGFß-mediated lens EMT and fibrosis.
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Opacificación Capsular , Cristalino , Humanos , Ratas , Animales , Ratones , Metaloproteinasa 2 de la Matriz/metabolismo , Proteínas Señalizadoras YAP , Cristalino/metabolismo , Células Epiteliales/metabolismo , Opacificación Capsular/patología , Factor de Crecimiento Transformador beta/metabolismo , FibrosisRESUMEN
Sudden cardiac arrest (CA) is the third leading cause of death. Immediate reoxygenation with high concentrations of supplemental oxygen (O2) during cardiopulmonary resuscitation (CPR) is recommended according to the current guidelines for adult CA. However, a point in controversy exists because of the known harm of prolonged exposure to 100% O2. Therefore, there have been much debate on an optimal use of supplemental O2, yet little is known about the duration and dosage of O2 administration. To test whether supplying a high concentration of O2 during CPR and post resuscitation is beneficial or harmful, rats subjected to 10-minute asphyxia CA were administered either 100% O2 (n = 8) or 30% O2 (n = 8) for 2 hours after CPR. Two hours after initiating CPR, the brain, lung, and heart tissues were collected to compare mRNA gene expression levels of inflammatory cytokines, apoptotic and oxidative stress-related markers. The 100% O2 group had significantly shorter time to return of spontaneous circulation (ROSC) than the 30% O2 group (62.9 ± 2.2 and 77.5 ± 5.9 seconds, respectively, P < 0.05). Arterial blood gas analysis revealed that the 100% O2 group had significantly higher PaCO2 (49.4 ± 4.9 mmHg and 43.0 ± 3.0 mmHg, P < 0.01), TCO2 (29.8 ± 2.7 and 26.6 ± 1.1 mmol/L, P < 0.05), HCO3- (28.1 ± 2.4 and 25.4 ± 1.2 mmol/L, P < 0.05), and BE (2.6 ± 2.3 and 0.1 ± 1.4 mmol/L, P < 0.05) at 2 hours after initiating CPR, but no changes in pH (7.37 ± 0.03 and 7.38 ± 0.03, ns). Inflammation- (Il6, Tnf) and apoptosis- (Casp3) related mRNA gene expression levels were significantly low in the 100% O2 group in the brain, however, oxidative stress moderator Hmox1 increased in the 100% O2 group. Likewise, mRNA gene expression of Icam1, Casp9, Bcl2, and Bax were low in the 100% O2 group in the lung. Contrarily, mRNA gene expression of Il1b and Icam1 were low in the 30% O2 group in the heart. Supplying 30% O2 during and after CPR significantly delayed the time to ROSC and increased inflammation-/apoptosis- related gene expression in the brain and lung, indicating that insufficient O2 was associated with unfavorable biological responses post CA, while prolonged exposure to high-concentration O2 should be still cautious in general.
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Reanimación Cardiopulmonar , Ratas , Animales , Oxígeno , Inflamación , ARN Mensajero , Terapia por Inhalación de OxígenoRESUMEN
OBJECTIVE: Using a system, which accuracy is equivalent to the gold standard Douglas Bag (DB) technique for measuring oxygen consumption (VO2), carbon dioxide generation (VCO2), and respiratory quotient (RQ), we aimed to continuously measure these metabolic indicators and compare the values between post-cardiothoracic surgery and critical care patients. METHODS: This was a prospective, observational study conducted at a suburban, quaternary care teaching hospital. Age 18 years or older patients who underwent mechanical ventilation were enrolled. RESULTS: We included 4 post-surgery and 6 critical care patients. Of those, 3 critical care patients died. The longest measurement reached to 12 h and 15 min and 50 cycles of repeat measurements were performed. VO2 of the post-surgery patients were 234 ± 14, 262 ± 27, 212 ± 16, and 192 ± 20 mL/min, and those of critical care patients were 122 ± 20, 189 ± 9, 191 ± 7, 191 ± 24, 212 ± 12, and 135 ± 21 mL/min, respectively. The value of VO2 was more variable in the post-surgery patients and the range of each patient was 44, 126, 71, and 67, respectively. SOFA scores were higher in non-survivors and there were negative correlations of RQ with SOFA. CONCLUSIONS: We developed an accurate system that enables continuous and repeat measurements of VO2, VCO2, and RQ. Critical care patients may have less activity in metabolism represented by less variable values of VO2 and VCO2 over time as compared to those of post-cardiothoracic surgery patients. Additionally, an alteration of these values may mean a systemic distinction of the metabolism of critically ill patients.
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Cuidados Críticos , Consumo de Oxígeno , Humanos , Adolescente , Estudios Prospectivos , Calorimetría Indirecta/métodos , Respiración Artificial , Dióxido de Carbono/metabolismoRESUMEN
Background: High learner engagement is important for the success of asynchronous and online learning for graduate medical education. Medical trainees have recently reported using medical mobile apps. App-based interactions may provide more participation than email-based interactions. We sought to investigate (1) if there were higher levels of engagement with an online curriculum using notifications sent via email as compared with via text, and (2) if there were higher levels of engagement with the mobile app or website format. Methods: We implemented an online Journal Club curriculum with weekly topics for anesthesiology residents (postgraduate years 2-4) from July 2020 to June 2021. Weekly notifications were sent to residents via email for weeks 1-10, text for weeks 11-20, then email for weeks 21-49. Based on activity logs, we compared (1) the weekly numbers of interactions when email notifications were sent with the weekly numbers of interactions when text notifications were sent, and (2) the weekly numbers of interactions via the app with the weekly numbers of interactions via the website. Results: Thirty-eight of the 54 anesthesiology residents in our department at the time of the study (70.4%) interacted with the online Journal Club at least once throughout the study. The weekly numbers of interactions with email notifications (median [interquartile range (IQR)]: 13 [7-28]) were significantly higher than with text notifications (median [IQR]: 6 [4-8]) (P = .023). The weekly numbers of interactions via the website (median [IQR]: 9 [4-24]) were significantly higher than via the app (median [IQR]: 0 [0-1]) (P < .001). Conclusions: Although mobile technology may increase engagement and participation for some educational resources, learners may prefer accessing others through more conventional methods.
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INTRODUCTION: Patients admitted to the pediatric Intensive Care Unit (PICU) are frequently sedated, restrained, and placed on bed rest. These practices have known negative impacts including prolonged hospital stay and diminished functional status after discharge. The authors' objective was to investigate the impact of a PICU early mobility protocol on the frequency of orders for physical, occupational, and speech therapy (PT, OT, ST) and improvement in patient functional status. METHODS: Patients admitted in 2019 prior to the development of the PICU early mobility protocol were compared to those admitted in 2020 who underwent the protocol. Differences in clinical characteristics; PICU length of stay; rates of PT, OT, and ST orders; rates of bedside mobility activities; and functional status scores (FSSs) were assessed in bivariate and multivariate analyses. The protocol included early PT, OT, and ST order placement and frequent in-room mobility activities. RESULTS: Of the 384 patients included in the study, 216 (56%) were preprotocol patients, and 168 (44%) underwent the protocol. Patients in 2020 were more likely to receive a physical therapy order compared to their 2019 counterparts (79% vs 47%, p < 0.001). Patients in 2020 had a higher daily incidence of mobility activities compared to those in 2019 (4.88 activities vs 4.1 activities, p < 0.001). Changes in functional status scores were similar between the 2 groups. CONCLUSION: PICU early mobility was associated with increased physical, occupational, and speech therapy orders and daily mobility activities but was not associated with a reduction in functional morbidity at discharge or 3 months post-discharge.
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Cuidados Posteriores , Estado Funcional , Niño , Humanos , Alta del Paciente , Unidades de Cuidado Intensivo Pediátrico , HospitalizaciónRESUMEN
BACKGROUND: For children with upper brachial plexus birth injury (BPBI; C5, C6, ±C7 roots), most clinics first recommend nonsurgical treatment followed by primary and/or secondary surgical interventions in selected patients. Since 2008, we have used an infant shoulder repositioning protocol (supination-external rotation [Sup-ER]) designed to prevent shoulder internal rotation contracture and its potential effects on the shoulder joint. This study characterizes our clinic's current choice, number, and timing of primary and secondary procedural interventions (including Botox) and compares Sup-ER protocol patients with those of our historical controls. METHODS: The records of all patients with upper BPBI who underwent procedures from 2001 to 2018 were retrospectively reviewed and grouped into a historical (2001-2007, n = 20) and recent (2008-2018, n = 23) cohort. Patient demographics, procedure types and timing, and functional outcomes were collected and analyzed. RESULTS: Since the 2008 institution of the Sup-ER protocol, fewer brachial plexus exploration and grafting (BPEG) surgeries were performed and none in later infancy, where nerve transfers were preferred. There were more and earlier Botox injections. There were fewer tendon transfers, and the preoperative indications were from a higher level of function. CONCLUSIONS: We now see fewer indications for BPEG surgeries overall. After the 3-month-age group, more direct nerve transfers are indicated instead of the BPEG surgery if nerve surgery is required at all. Shoulder tendon transfer rates have decreased. Humeral osteotomies are not seen in our recent group. Glenoid osteotomies within tendon transfers are rare in both groups.
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Purine nucleotide adenosine triphosphate (ATP) is a source of intracellular energy maintained by mitochondrial oxidative phosphorylation. However, when released from ischemic cells into the extracellular space, they act as death-signaling molecules (eATP). Despite there being potential benefit in using pyruvate to enhance mitochondria by inducing a highly oxidative metabolic state, its association with eATP levels is still poorly understood. Therefore, while we hypothesized that pyruvate could beneficially increase intracellular ATP with the enhancement of mitochondrial function after cardiac arrest (CA), our main focus was whether a proportion of the raised intracellular ATP would detrimentally leak out into the extracellular space. As indicated by the increased levels in systemic oxygen consumption, intravenous administrations of bolus (500 mg/kg) and continuous infusion (1000 mg/kg/h) of pyruvate successfully increased oxygen metabolism in post 10-min CA rats. Plasma ATP levels increased significantly from 67 ± 11 nM before CA to 227 ± 103 nM 2 h after the resuscitation; however, pyruvate administration did not affect post-CA ATP levels. Notably, pyruvate improved post-CA cardiac contraction and acidemia (low pH). We also found that pyruvate increased systemic CO2 production post-CA. These data support that pyruvate has therapeutic potential for improving CA outcomes by enhancing oxygen and energy metabolism in the brain and heart and attenuating intracellular hydrogen ion disorders, but does not exacerbate the death-signaling of eATP in the blood.
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Cardiac arrest (CA) and concomitant post-CA syndrome lead to a lethal condition characterized by systemic ischemia-reperfusion injury. Oxygen (O2 ) supply during cardiopulmonary resuscitation (CPR) is the key to success in resuscitation, but sustained hyperoxia can produce toxic effects post CA. However, only few studies have investigated the optimal duration and dosage of O2 administration. Herein, we aimed to determine whether high concentrations of O2 at resuscitation are beneficial or harmful. After rats were resuscitated from the 10-min asphyxia, mechanical ventilation was restarted at an FIO2 of 1.0 or 0.3. From 10 min after initiating CPR, FIO2 of both groups were maintained at 0.3. Bio-physiological parameters including O2 consumption (VO2 ) and mRNA gene expression in multiple organs were evaluated. The FIO2 0.3 group decreased VO2 , delayed the time required to achieve peak MAP, lowered ejection fraction (75.1 ± 3.3% and 59.0 ± 5.7% with FIO2 1.0 and 0.3, respectively; p < .05), and increased blood lactate levels (4.9 ± 0.2 mmol/L and 5.6 ± 0.2 mmol/L, respectively; p < .05) at 10 min after CPR. FIO2 0.3 group had significant increases in hypoxia-inducible factor, inflammatory, and apoptosis-related mRNA gene expression in the brain. Likewise, significant upregulations of hypoxia-inducible factor and apoptosis-related gene expression were observed in the FIO2 0.3 group in the heart and lungs. Insufficient O2 supplementation in the first 10 min of resuscitation could prolong ischemia, and may result in unfavorable biological responses 2 h after CA. Faster recovery from the impairment of O2 metabolism might contribute to the improvement of hemodynamics during the early post-resuscitation phase; therefore, it may be reasonable to provide the maximum feasible O2 concentrations during CPR.
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Reanimación Cardiopulmonar , Paro Cardíaco , Ratas , Animales , Oxígeno , Paro Cardíaco/terapia , Hemodinámica , Hipoxia , Modelos Animales de EnfermedadRESUMEN
Simulation-based training plays an essential role in transesophageal echocardiography (TEE) education. Using 3-dimensional printing technology, the authors invented a novel TEE teaching system consisting of a series of heart models that can be segmented according to actual TEE views, and an ultrasound omniplane simulator to demonstrate how ultrasound beams intersect the heart at different angles and generate images. This novel teaching system is able to provide a more direct way to visualize the mechanics of obtaining TEE images than traditional online or mannequin-based simulators. It can also provide tangible feedback of both an ultrasound scan plane and a TEE view of the heart, which has been proven to improve trainees' spatial awareness and can significantly help in understanding and memorizing complex anatomic structures. This teaching system itself is also portable and inexpensive, making it conducive to teaching TEE in regions of diverse economic status. This teaching system also can be expected to be used for just-in-time training in a variety of clinical scenarios, including operating rooms, intensive care units, etc.
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Ecocardiografía Tridimensional , Entrenamiento Simulado , Humanos , Ecocardiografía Transesofágica/métodos , Corazón , Maniquíes , Unidades de Cuidados IntensivosRESUMEN
BACKGROUND: Point-of-care ultrasound (POCUS) is commonly employed to image the heart, lungs, and abdomen. Rapid ultrasound for shock and hypotension (RUSH) exams are a critical component of POCUS employed in austere environments by Special Operations Forces (SOF) and tactical medics for triage and diagnosis. Despite its utility, training for POCUS remains largely unstandardized with respect to feedback and markers of proficiency. We hypothesized that motion analysis could objectively identify improvement in medics' performance of RUSH exams. Furthermore, we predicted that motion metrics would correlate with qualitative ratings administered by attending anesthesiologists. METHODS: A team of civilian and military attending anesthesiologists trained 24 medics in POCUS during a 5-day course. Each medic performed eight RUSH exams using an ultrasound probe equipped with an electromagnetic motion sensor to track total distance travelled (path length), movements performed (translational motions), degrees rotated (rotational sum), and time. Instructors (experts) observed and rated the exams on the following items: image finding, image fine-tuning, speed, final image accuracy, and global assessment. Motion metrics were used to provide feedback to medics throughout the course. Generalized estimating equations were used to analyze the trends of motion metrics across all trials. Correlations amongst motion metrics and expert ratings were assessed with Pearson correlation coefficients. RESULTS: Participants exhibited a negative trend in all motion metrics (p < 0.001). Pearson correlation coefficients revealed moderate inverse correlations amongst motion metrics and expert ratings. CONCLUSION: Motion analysis was able to quantify and describe the performance of medics training in POCUS and correlated with expert ratings.
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Personal Militar , Sistemas de Atención de Punto , Humanos , Curriculum , Ultrasonografía/métodos , Personal Militar/educaciónRESUMEN
The over-use of synthetic nitrogen (N) fertilisers for crop production can cause environmental pollution through leaching and gaseous losses, resulting in low N use efficiency (NUE). Previous work has shown that brown coal (BC) combined with urea can slow down the fertiliser-N release to better synchronise soil N supply with crop N demand. The study aimed to evaluate the impact of granulated BC-urea (BCU) applied to sweet corn on NUE, fate and recovery of fertiliser-N using an 15N tracer technique. In this in-field microcosm study, 10 atom percent enriched 15N-labelled urea (46% N) and BCU (20% N) were applied as N fertilisers at rates of 90 or 180 kg N ha-1. On average, BCU fertiliser reduced the urea-derived 15N losses as nitrous oxide (N2O) by 64%, ammonia (NH3) by 73% and downward movement of total N by 59% compared to urea. Reduced losses of applied BCU fertiliser-15N were associated with significantly increased microbial immobilisation, soil retention and availability of fertiliser-15N to plants for longer periods of time, compared with urea. As a result, BCU enhanced cob yield by an average of 23%, 15N uptake by 21% and fertiliser NUE by 21% over urea. The plant recovery of fertiliser-15N was significantly higher from BCU (59%) than the recovery from urea (38%). Moreover, mining of native soil-N was lower when the N-fertiliser source was BCU cf. urea, suggesting that BCU could be used as a more N-efficient alternative to urea in cropping systems.
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Fertilizantes , Nitrógeno , Nitrógeno/análisis , Fertilizantes/análisis , Urea , Carbón Mineral , Suelo , Óxido Nitroso/análisis , Plantas , Agricultura/métodosRESUMEN
BACKGROUND: Randomised controlled trials (RCTs) are considered the "gold standard" for evaluating the effectiveness of interventions in clinical research. However, conventional RCTs are typically complex, expensive, and have narrow eligibility criteria, which limits generalisability. Registry-based randomised controlled trials (RRCTs) are an alternative approach that integrates the internal validity of an RCT with the external validity of a clinical registry by recruiting real-world patients and leveraging an existing registry platform for data collection. As RRCT is a novel research design, there has been limited research on the feasibility and acceptability of RRCTs from the patients' and trial team's perspectives. This study aims to explore patients', clinicians', and study coordinators' perspectives towards participation in and conduct of oncology RRCTs in Australia. METHODS: Thirty-seven semi-structured interviews were conducted with 15 cancer patients, 15 clinicians, and 7 study coordinators. Interviews were audio-recorded and transcribed verbatim. The data were analysed using thematic analysis. RESULTS: Three overarching themes were identified: (1) enablers and barriers to recruitment and enrolment of patients in RRCTs, (2) experiences of patients participating in RRCTs, and (3) recommendations for the implementation of future RRCTs. For patients, altruism and "trust in the clinician" were key reasons to participate in a RRCT. For clinicians and clinical trial coordinators, the RRCT study design was perceived as "simple and straightforward" but "less exciting" than RCTs. Competition from commercially sponsored RCTs poses challenges for investigator-led RRCTs recruitment, particularly if eligible patient numbers are low. There were limited impacts on patients' treatment experiences and clinicians' clinical workflow given that the RRCTs explored different standards of care. Recommendations to improve the enrolment of patients in RRCTs included generating greater buy-in from clinicians by increasing awareness of RRCTs via education initiatives and broader promotion of the "selling point" of RRCTs and providing monetary compensation to hospitals for enrolling patients. CONCLUSIONS: Whilst patients, clinicians, and study coordinators were generally supportive of RRCTs, several barriers to effective RRCT implementation in oncology were identified. Developing strategies to increase acceptance of the methodology by clinicians will help enhance the uptake of RRCTs in Australia and internationally.
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Neoplasias , Humanos , Estudios de Factibilidad , Investigación Cualitativa , Sistema de Registros , Neoplasias/diagnóstico , Neoplasias/terapia , Investigadores , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Fragmentation is a major degradation pathway ubiquitous to all therapeutic monoclonal antibody (mAb) and therefore, monitored throughout the manufacturing process. Here, we describe a three-step approach to 1) detect, 2) confirm and 3) characterize partially reduced fragment species in an immunoglobulin G1 (IgG1) mAb with prolonged hold time of harvested cell culture fluid (HCCF). Microchip capillary electrophoresis (MCE) and high-performance size exclusion chromatography (HPSEC) were used as fast and efficient screening methods to detect fragmentation. HPSEC was found to be underestimating fragmentation levels. To confirm and characterize the fragments, capillary electrophoresis-sodium dodecyl sulphate (CE-SDS) was employed. Interestingly, the absence of fragments in the reduced CE-SDS analysis suggested partial reduction of disulphide bonds contributing to fragmentation in this mAb lot. This was further confirmed using reverse phase high performance liquid chromatography (RP-HPLC) coupled with mass spectrometry, which established the presence of heavy-heavy-light (HHL), heavy-heavy (HH), light-light dimer (LL), light chain (LC) and half antibody (HL) fragments with good mass accuracy. In this study, we demonstrated a readily applicable systematic strategy to support process development and investigate anomalous events in manufacturing. An additional highlight of this work is the data-driven comprehensive comparison of modern and conventional analytical techniques for fragment analysis.
Asunto(s)
Anticuerpos Monoclonales , Cromatografía de Fase Inversa , Anticuerpos Monoclonales/química , Flujo de Trabajo , Espectrometría de Masas , Cromatografía en GelRESUMEN
Cardiac arrest (CA) patients suffer from systemic ischemia-reperfusion (IR) injury leading to multiple organ failure; however, few studies have focused on tissue-specific pathophysiological responses to IR-induced oxidative stress. Herein, we investigated biological and physiological parameters of the brain and heart, and we particularly focused on the lung dysfunction that has not been well studied to date. We aimed to understand tissue-specific susceptibility to oxidative stress and tested how oxygen concentrations in the post-resuscitation setting would affect outcomes. Rats were resuscitated from 10 min of asphyxia CA. Mechanical ventilation was initiated at the beginning of cardiopulmonary resuscitation. We examined animals with or without CA, and those were further divided into the animals exposed to 100% oxygen (CA_Hypero) or those with 30% oxygen (CA_Normo) for 2 h after resuscitation. Biological and physiological parameters of the brain, heart, and lungs were assessed. The brain and lung functions were decreased after CA and resuscitation indicated by worse modified neurological score as compared to baseline (222 ± 33 vs. 500 ± 0, P < 0.05), and decreased PaO2 (20 min after resuscitation: 113 ± 9 vs. baseline: 128 ± 9 mmHg, P < 0.05) and increased airway pressure (2 h: 10.3 ± 0.3 vs. baseline: 8.1 ± 0.2 mmHg, P < 0.001), whereas the heart function measured by echocardiography did not show significant differences compared before and after CA (ejection fraction, 24 h: 77.9 ± 3.3% vs. baseline: 82.2 ± 1.9%, P = 0.2886; fractional shortening, 24 h: 42.9 ± 3.1% vs. baseline: 45.7 ± 1.9%, P = 0.4658). Likewise, increases of superoxide production in the brain and lungs were remarkable, while those in the heart were moderate. mRNA gene expression analysis revealed that CA_Hypero group had increases in Il1b as compared to CA_Normo group significantly in the brain (P < 0.01) and lungs (P < 0.001) but not the heart (P = 0.4848). Similarly, hyperoxia-induced increases in other inflammatory and apoptotic mRNA gene expression were observed in the brain, whereas no differences were found in the heart. Upon systemic IR injury initiated by asphyxia CA, hyperoxia-induced injury exacerbated inflammation/apoptosis signals in the brain and lungs but might not affect the heart. Hyperoxia following asphyxia CA is more damaging to the brain and lungs but not the heart.