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1.
J Am Chem Soc ; 146(36): 25151-25157, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39222363

RESUMEN

The electrocatalytic reduction process is a promising technology for decomposing chlorinated organic pollutants in water but is limited by the lack of low-cost catalysts that can achieve high activity and selectivity. In studying electrochemical dechlorination of 2-chlorophenol (2-CP) in aqueous media, we find that cobalt phthalocyanine molecules supported on carbon nanotubes (CoPc/CNT), which is a highly effective electrocatalyst for breaking the aliphatic C-Cl bonds in 1,2-dichloroethane (DCA) and trichloroethylene (TCE), are completely inactive for reducing the aromatic C-Cl bond in 2-CP. Detailed mechanistic investigation, including volcano plot correlation between dechlorination rate and atomic hydrogen adsorption energy on various transition metal surfaces, kinetic measurements, in situ Raman spectroscopy, and density functional theory calculations, reveals that the reduction of the aromatic C-Cl bond in 2-CP goes through a hydrodechlorination mechanism featuring a bimolecular reaction between adsorbed atomic hydrogen and 2-CP on the catalyst surface, which requires neighboring catalytic sites, whereas the aliphatic C-Cl bonds in DCA and TCE are cleaved by direct electron transfer from the catalyst, which can occur on isolated single sites. This investigation leads to the discovery of metallic Co as a highly selective and active electrocatalyst for 2-CP dechlorination. This work provides new insights into the fundamental chemistry and catalyst design of electrochemical dechlorination reactions for wastewater treatment.

2.
J Neurosurg Spine ; : 1-8, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39332029

RESUMEN

OBJECTIVE: This study aimed to report changes in utilization and payment trends of low-back pain (LBP) interventions and the impact of nonsurgeon interventionalists on these changes. METHODS: Medicare Part B national summary data files were used to gather annual utilization and Centers for Medicare and Medicaid Services (CMS) payment data for LBP interventions from 2000 to 2021. Healthcare Common Procedure Coding System (HCPCS) codes were grouped as decompression, spinal fusion, sacroiliac (SI) joint fusion, epidural steroid injections (ESIs), physical therapy (PT), and chiropractic manipulation (Chiro). The total allowed services and payments were collected for each HCPCS group. CMS provider-level files, available from 2013 to 2021, were used to collect neurosurgeon, orthopedic surgeon, and nonsurgeon interventionalist (interventional radiology and pain management) data for each surgical HCPCS code group (decompression, spinal fusion, and SI joint fusion). The United States Consumer Price Index was used to adjust for inflation. RESULTS: From 2000 to 2021, there were 339,720,725 Medicare-approved interventions and payments of approximately $21 billion for LBP (percentage of cumulative payments: 41.8% Chiro, 16.5% ESI, 14.4% spinal fusion, 14.3% PT, 10.2% decompression, and 0.4% SI joint fusion). In a subgroup analysis, spinal fusions for Medicare patients were performed by orthopedic surgeons (59.2%), neurosurgeons (40.6%), and nonsurgeon interventionalists (< 1%) from 2013 to 2021. From 2013 to 2021, neurosurgeon and orthopedic surgeon fusion utilization each grew by < 3% and associated Medicare payments to each specialty declined by 1% each year. During the same period, nonsurgeon interventionalist utilization grew 26% each year and associated Medicare payments to nonsurgeon interventionalists for spine fusions grew 62% each year. In a subgroup analysis, SI joint fusions for Medicare patients were performed by orthopedic surgeons (50.7%), neurosurgeons (24.8%), and nonsurgeon interventionalists (24.5%) from 2018 to 2021. Neurosurgeon utilization of SI joint fusion declined by 1% each year and associated Medicare payments to this group grew 2% each year. Orthopedic surgeon utilization of SI joint fusion declined 1% and associated Medicare payments to this group grew 4% each year. Nonsurgeon interventionalist use of SI joint fusions grew 415% and payments grew 435% each year. CONCLUSIONS: The substantial growth in Medicare payments for surgical LBP interventions is disproportionally driven by nonsurgeon interventionalists. The exponential growth of nonsurgeon interventionalists performing spinal fusion surgeries, particularly SI joint fusions, largely accounts for the significant increase in Medicare expenditures.

3.
Nanoscale Horiz ; 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39320147

RESUMEN

We studied the exciton delocalization of indodicarbocyanine 5 dye derivative (Cy5-R) heterodimers templated by a DNA Holliday junction (HJ), which was quantified by the exciton hopping parameter Jm,n. These dyes were modified at the 5 and 5' positions of indole rings with substituent (R) H, Cl, tBu, Peg, and hexyloxy (Hex) groups that exhibit different bulkiness and electron-withdrawing/donating capacities. The substituents tune the physical properties of the dyes, such as hydrophobicity (log P) and solvent-accessible surface area (SASA). We tuned the Jm,n of heterodimers by attaching two Cy5-Rs in adjacent and transverse positions along the DNA-HJ. Adjacent heterodimers exhibited smaller Jm,n compared to transverse heterodimers, and some adjacent heterodimers displayed a mixture of H- and J-like aggregates. Most heterodimers exhibited Jm,n values within the ranges of the corresponding homodimers, but some heterodimers displayed synergistic exciton delocalization that resulted in larger Jm,n compared to their homodimers. We then investigated how chemically distinct Cy5-R conjugated to DNA can interact to create delocalized excitons. We determined that heterodimers involving Cy5-H and Cy5-Cl and a dye with larger substituents (bulky substituents and large SASA) such as Cy5-Peg, Cy5-Hex, and Cy5-tBu resulted in larger Jm,n. The combination provides steric hindrance that optimizes co-facial packing (bulky Cy5-R) with a smaller footprint (small SASA) that maximizes proximity. The results of this study lay a groundwork for rationally optimizing the exciton delocalization in dye aggregates for developing next-generation technologies based on optimized exciton transfer efficiency such as quantum information systems and biomedicine.

4.
Surgery ; 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39327129

RESUMEN

BACKGROUND: The Whipple procedure for pancreatic adenocarcinoma frequently is referred to surgeons at high-volume centers, which requires that patients travel long distances, potentially impacting patient outcomes. Furthermore, patients with pancreatic cancer from underserved areas often have poor outcomes. There are limited data on Whipple outcomes on the basis of both socioeconomic and distance traveled. METHODS: This retrospective cohort study examined patients who underwent the Whipple procedure for pancreatic adenocarcinoma at a tertiary care center from 2019 to 2021. Patients who lived in areas with an Area Deprivation Index national percentile of >50% and ≥100 miles away from the care center were labeled as "at-risk" patients. RESULTS: Seventy-eight patients were included, with 22 (28.2%) patients determined to be at risk. The preoperative characteristics were comparable between the patients in the at-risk and standard-risk groups. Postoperatively, patients in the at-risk group were more likely to require reoperation (13.6% vs 0%; P = .020) and less likely to undergo adjuvant chemotherapy (73.2% vs 50%; P = .034) than patients in the standard-risk group; pathologic staging and frequency of previous use of neoadjuvant chemotherapy were not significantly different between the groups. At-risk status did not influence overall survival or recurrence rate. CONCLUSIONS: Through the integration of distance traveled and Area Deprivation Index, we have redefined the characterization of at-risk patients with pancreatic adenocarcinoma, who are at greater risk of undergoing reoperation and not receiving adjuvant chemotherapy. By addressing these intersecting challenges, providers can mitigate disparities and improve the care of these patients with pancreatic adenocarcinoma.

5.
J Chem Theory Comput ; 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39264121

RESUMEN

Nanoengineered metal@zeolite materials have recently emerged as a promising class of catalysts for several industrially relevant reactions. These materials, which consist of small transition metal nanoclusters confined within three-dimensional zeolite pores, are interesting because they show higher stability and better sintering resistance under reaction conditions. While several such hybrid catalysts have been reported experimentally, key questions such as the impact of the zeolite frameworks on the properties of the metal clusters are not well understood. To address such knowledge gaps, in this study, we report a robust and transferable machine learning-based potential (MLP) that is capable of describing the structure, stability, and dynamics of zeolite-confined gold nanoclusters. Specifically, we show that the resulting MLP maintains ab initio accuracy across a range of temperatures (300-1000 K) and can be used to investigate time scales (>10 ns), length scales (ca. 10,000 atoms), and phenomena (e.g., ensemble-averaged stability and diffusivity) that are typically inaccessible using density functional theory (DFT). Taken together, this study represents an important step in enabling the rational theory-guided design of metal@zeolite catalysts.

6.
JTCVS Open ; 20: 14-25, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39296446

RESUMEN

Objective: We examined the effect of frailty on in-hospital mortality, readmission rates, and hospitalization costs after transcatheter and surgical aortic valve replacement in a population-level cohort. Methods: The Nationwide Readmissions Database was queried for patients who underwent transcatheter or surgical aortic valve replacement during 2016-2018. Multivariate logistic regression was used to discern independent effects of frailty on outcomes. Kaplan-Meier time-to-event analysis was used to evaluate the effect of frailty on freedom from readmission. Results: A total of 243,619 patients underwent aortic valve replacement: 142,786 (58.6%) transcatheter aortic valve replacements and 100,833 (41.4%) surgical aortic valve replacements. Frail patients constituted 16,388 (11.5%) and 7251 (7.2%) in the transcatheter aortic valve replacement and surgical aortic valve replacement cohorts, respectively. Compared with nonfrail patients, frail patients had greater in-hospital mortality (transcatheter aortic valve replacement: 3.2% vs 1.1%; surgical aortic valve replacement: 6.1% vs 2.0%; both P < .001), longer length of stay (transcatheter aortic valve replacement: 4 vs 2 days; surgical aortic valve replacement: 13 vs 6 days; P < .001), and greater cost (transcatheter aortic valve replacement: $51,654 vs $44,401; surgical aortic valve replacement: $60,782 vs $40,544; P < .001). Time-to-event analysis showed that frail patients had higher rates of readmission over the calendar year in both transcatheter aortic valve replacement (P < .001) and surgical aortic valve replacement (P < .001) cohorts. This association persisted on adjusted multivariate regression for mortality (transcatheter aortic valve replacement odds ratio [95% CI] 1.98 [1.65-2.37], surgical aortic valve replacement 1.96 [1.60-2.41]), 30-day readmission (transcatheter aortic valve replacement 1.38 [1.27-1.49], surgical aortic valve replacement 1.47 [1.30-1.65]), and 90-day readmission (transcatheter aortic valve replacement 1.41 [1.31-1.52], surgical aortic valve replacement 1.60 [1.43-1.79]) (P < .001 for all). Conclusions: For patients undergoing transcatheter or surgical aortic valve replacement, frailty is associated with in-hospital mortality, readmission, and higher costs. Further efforts to optimize outcomes for frail patients are warranted.

7.
BMC Cardiovasc Disord ; 24(1): 497, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39289597

RESUMEN

BACKGROUND: Improving hypertension control is a public health priority. However, consistent identification of uncontrolled hypertension using computable definitions in electronic health records (EHR) across health systems remains uncertain. METHODS: In this retrospective cohort study, we applied two computable definitions to the EHR data to identify patients with controlled and uncontrolled hypertension and to evaluate differences in characteristics, treatment, and clinical outcomes between these patient populations. We included adult patients (≥ 18 years) with hypertension (based on either ICD-10 codes of hypertension or two elevated blood pressure [BP] measurements) receiving ambulatory care within Yale-New Haven Health System (YNHHS; a large US health system) and OneFlorida Clinical Research Consortium (OneFlorida; a Clinical Research Network comprised of 16 health systems) between October 2015 and December 2018. We identified patients with controlled and uncontrolled hypertension based on either a single BP measurement from a randomly selected visit or all BP measurements recorded between hypertension identification and the randomly selected visit). RESULTS: Overall, 253,207 and 182,827 adults at YNHHS and OneFlorida were identified as having hypertension. Of these patients, 83.1% at YNHHS and 76.8% at OneFlorida were identified using ICD-10-CM codes, whereas 16.9% and 23.2%, respectively, were identified using elevated BP measurements (≥ 140/90 mmHg). A total of 24.1% of patients at YNHHS and 21.6% at OneFlorida had both diagnosis code for hypertension and elevated blood pressure measurements. Uncontrolled hypertension was observed among 32.5% and 43.7% of patients at YNHHS and OneFlorida, respectively. Uncontrolled hypertension was disproportionately higher among Black patients when compared with White patients (38.9% versus 31.5% in YNHHS; p < 0.001; 49.7% versus 41.2% in OneFlorida; p < 0.001). Medication prescription for hypertension management was more common in patients with uncontrolled hypertension when compared with those with controlled hypertension (overall treatment rate: 39.3% versus 37.3% in YNHHS; p = 0.04; 42.2% versus 34.8% in OneFlorida; p < 0.001). Patients with controlled and uncontrolled hypertension had similar incidence rates of deaths, CVD events, and healthcare visits at 3, 6, 12, and 24 months. The two computable definitions generated consistent results. CONCLUSIONS: While the current EHR systems are not fully optimized for disease surveillance and stratification, our findings illustrate the potential of leveraging EHR data to conduct digital population surveillance in the realm of hypertension management.


Asunto(s)
Antihipertensivos , Presión Sanguínea , Registros Electrónicos de Salud , Hipertensión , Humanos , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Hipertensión/tratamiento farmacológico , Hipertensión/epidemiología , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Antihipertensivos/uso terapéutico , Anciano , Presión Sanguínea/efectos de los fármacos , Adulto , Resultado del Tratamiento , Estados Unidos/epidemiología , Factores de Tiempo
8.
PLoS Pathog ; 20(9): e1012511, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39298524

RESUMEN

Molecular details of genome packaging are little understood for the majority of viruses. In enteroviruses (EVs), cleavage of the structural protein VP0 into VP4 and VP2 is initiated by the incorporation of RNA into the assembling virion and is essential for infectivity. We have applied a combination of bioinformatic, molecular and structural approaches to generate the first high-resolution structure of an intermediate in the assembly pathway, termed a provirion, which contains RNA and intact VP0. We have demonstrated an essential role of VP0 E096 in VP0 cleavage independent of RNA encapsidation and generated a new model of capsid maturation, supported by bioinformatic analysis. This provides a molecular basis for RNA-dependence, where RNA induces conformational changes required for VP0 maturation, but that RNA packaging itself is not sufficient to induce maturation. These data have implications for understanding production of infectious virions and potential relevance for future vaccine and antiviral drug design.

9.
Crit Care Med ; 52(10): 1499-1508, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39312458

RESUMEN

OBJECTIVES: Hyperkalemia is a common life-threatening condition causing severe electrophysiologic derangements and arrhythmias. The beneficial effects of calcium (Ca 2+ ) treatment for hyperkalemia have been attributed to "membrane stabilization," by restoration of resting membrane potential (RMP). However, the underlying mechanisms remain poorly understood. Our objective was to investigate the mechanisms underlying adverse electrophysiologic effects of hyperkalemia and the therapeutic effects of Ca 2+ treatment. DESIGN: Controlled experimental trial. SETTING: Laboratory investigation. SUBJECTS: Canine myocytes and tissue preparations. INTERVENTIONS AND MEASUREMENTS: Optical action potentials and volume averaged electrocardiograms were recorded from the transmural wall of ventricular wedge preparations ( n = 7) at baseline (4 mM potassium), hyperkalemia (8-12 mM), and hyperkalemia + Ca 2+ (3.6 mM). Isolated myocytes were studied during hyperkalemia (8 mM) and after Ca 2+ treatment (6 mM) to determine cellular RMP. MAIN RESULTS: Hyperkalemia markedly slowed conduction velocity (CV, by 67% ± 7%; p < 0.001) and homogeneously shortened action potential duration (APD, by 20% ± 10%; p < 0.002). In all preparations, this resulted in QRS widening and the "sine wave" pattern observed in severe hyperkalemia. Ca 2+ treatment restored CV (increase by 44% ± 18%; p < 0.02), resulting in narrowing of the QRS and normalization of the electrocardiogram, but did not restore APD. RMP was significantly elevated by hyperkalemia; however, it was not restored with Ca 2+ treatment suggesting a mechanism unrelated to "membrane stabilization." In addition, the effect of Ca 2+ was attenuated during L-type Ca 2+ channel blockade, suggesting a mechanism related to Ca 2+ -dependent (rather than normally sodium-dependent) conduction. CONCLUSIONS: These data suggest that Ca 2+ treatment for hyperkalemia restores conduction through Ca 2+ -dependent propagation, rather than restoration of membrane potential or "membrane stabilization." Our findings provide a mechanistic rationale for Ca 2+ treatment when hyperkalemia produces abnormalities of conduction (i.e., QRS prolongation).


Asunto(s)
Calcio , Hiperpotasemia , Hiperpotasemia/tratamiento farmacológico , Animales , Perros , Calcio/metabolismo , Potenciales de Acción/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Potenciales de la Membrana/efectos de los fármacos , Electrocardiografía , Membrana Celular/efectos de los fármacos
10.
Genet Med ; : 101278, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39315527

RESUMEN

PURPOSE: Biallelic INPP4A variants have recently been associated with severe neurodevelopmental disease in single case reports. Here, we expand and elucidate the clinical-genetic spectrum and provide a pathomechanistic explanation for genotype-phenotype correlations. METHODS: Clinical and genomic investigations of 30 individuals were undertaken alongside molecular and in silico modelling and translation reinitiation studies. RESULTS: We characterize a clinically variable disorder with cardinal features including global developmental delay, severe-profound intellectual disability, microcephaly, limb weakness, cerebellar signs and short stature. A more severe presentation associated with biallelic INPP4A variants downstream of exon 4 has additional features of (ponto)cerebellar hypoplasia, reduced cerebral volume, peripheral spasticity, contractures, intractable seizures and cortical visual impairment. Our studies identify the likely pathomechanism of this genotype-phenotype correlation entailing translational reinitiation in exon 4 resulting in an N-terminal truncated INPP4A protein retaining partial functionality, associated with less severe disease. We also identified identical reinitiation site conservation in Inpp4a-/- mouse models displaying similar genotype-phenotype correlation. Additionally, we show fibroblasts from a single affected individual exhibit disrupted endocytic trafficking pathways, indicating the potential biological basis of the condition. CONCLUSION: Our studies comprehensively characterise INPP4A-related neurodevelopmental disorder and suggest genotype-specific clinical assessment guidelines. We propose the potential mechanistic basis of observed genotype-phenotype correlations entails exon 4 translation reinitiation.

12.
Chem Sci ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39246371

RESUMEN

The reaction of the N,N-diisopropyl bromoiminium salt with excess sodium phosphaethynolate (NaPCO) affords a diphospha-urea 2. Under blue light irradiation (450 nm), carbon monoxide is liberated affording the bis(carbene)P2 adduct 3. Photolysis of a benzene solution of 3 at 365 nm gives rise to the carbene dimer, namely the 1,2-bis(diisopropylamino)ethylene as a cis/trans mixture, along with white and red phosphorus. Under the same experimental conditions, but in the presence of excess 2,3-dimethyl-1,3-butadiene, the classical double Diels-Alder adduct of the triple-bonded diphosphorus P[triple bond, length as m-dash]P was obtained along with the bis(phospholene) formally resulting from a double [4 + 1] reaction of the diene with the bis(phosphinidene) form of P2. A stepwise carbene-carbene exchange reaction also occurs between the monosubstituted aminocarbene of 3 and a cyclic (alkyl)(amino)carbene, possibly involving the transient formation of a diphosphorus analogue of a diazo compound.

13.
J Biomed Opt ; 29(Suppl 3): S33306, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-39247899

RESUMEN

Significance: The arterial input function (AIF) plays a crucial role in correcting the time-dependent concentration of the contrast agent within the arterial system, accounting for variations in agent injection parameters (speed, timing, etc.) across patients. Understanding the significance of the AIF can enhance the accuracy of tissue vascular perfusion assessment through indocyanine green-based dynamic contrast-enhanced fluorescence imaging (DCE-FI). Aim: We evaluate the impact of the AIF on perfusion assessment through DCE-FI. Approach: A total of 144 AIFs were acquired from 110 patients using a pulse dye densitometer. Simulation and patient intraoperative imaging were conducted to validate the significance of AIF for perfusion assessment based on kinetic parameters extracted from fluorescence images before and after AIF correction. The kinetic model accuracy was evaluated by assessing the variability of kinetic parameters using individual AIF versus population-based AIF. Results: Individual AIF can reduce the variability in kinetic parameters, and population-based AIF can potentially replace individual AIF for estimating wash-out rate ( k ep ), maximum intensity ( I max ), ingress slope with lower differences compared with those in estimating blood flow, volume transfer constant ( K trans ), and time to peak. Conclusions: Individual AIF can provide the most accurate perfusion assessment compared with assessment without AIF or based on population-based AIF correction.


Asunto(s)
Verde de Indocianina , Imagen Óptica , Humanos , Imagen Óptica/métodos , Verde de Indocianina/química , Verde de Indocianina/farmacocinética , Femenino , Persona de Mediana Edad , Anciano , Masculino , Medios de Contraste/química , Adulto , Arterias/diagnóstico por imagen , Imagen de Perfusión/métodos , Simulación por Computador
15.
Front Psychol ; 15: 1407734, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39282681

RESUMEN

Hamdan Intelligence Scale (HIS) is the first intelligence scale that has been developed and normed in the United Arab Emirates (UAE). This study aimed to examine the refinement, validity, and reliability of HIS in upper elementary grades using the Rasch model. A total of 4,301 students (34.3% Male; 65.7% Female) from grade 4 to 6 (32.1% grade 4; 33.7% grade 5; 34.2% grade 6) were administered to the HIS. The confirmatory factor analysis was first conducted to verify the fitness of the one-factor model of the HIS. The results of validity showed strong correlation coefficients between the HIS and the Aurora-g battery (0.83) and the Raven's Standard Progressive Matrices (RSPM; 0.86). Moreover, the results of the developmental trends demonstrated that raw scores of the HIS increase with age and grade relatively constantly across composite scores. Unidimensionality was confirmed through the Confirmatory Factor Analysis and Principal Component Analysis of Residuals (PCAR). The low eigenvalues of the first contrast were below 2, and additionally, the infit and outfit mean squares ranged from 0.88 to 1.14 and 0.84 to 1.14. Rasch's person reliability result of 0.62 was acceptable reliability. The results provided strong support for the validity and reliability of using the Hamdan Intelligence Scale in the UAE environment.

16.
J Physiol ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39269684

RESUMEN

We investigated second-messenger signalling components linked to the stimulation of Gq protein-coupled receptors (e.g. thromboxane A2 and bradykinin B2 receptors) on the sensory endings of thin fibre muscle afferents in the chronic mechanoreflex sensitization in rats with myocardial infarction-induced heart failure with reduced ejection fraction (HF-rEF). We hypothesized that injection of either the inositol 1,4,5-trisphosphate (IP3) receptor antagonist xestospongin C (5 µg) or the PKCε translocation inhibitor PKCe141 (45 µg) into the arterial supply of the hindlimb would reduce the increase in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) evoked during 30 s of 1 Hz dynamic hindlimb muscle stretch in decerebrate, unanaesthetized HF-rEF rats but not sham-operated controls (SHAM). Ejection fraction was significantly reduced in HF-rEF (45 (19)%) compared to SHAM (80 (9)%; P < 0.001) rats. In HF-rEF rats (n = 3M/2F), IP3 receptor blockade had no effect on the peak ΔRSNA (pre: 99 (74)%; post: 133 (79)%; P = 0.974) or peak ΔMAP response to stretch (peak ΔMAP: pre: 32 (14) mmHg; post: 36 (21) mmHg; P = 0.719). Conversely, in another group of HF-rEF rats (n = 4M/3F), the PKCε translocation inhibitor reduced the peak ΔRSNA (pre: 110 (77)%; post: 62 (58)%; P = 0.029) and peak ΔMAP response to stretch (pre: 30 (20) mmHg; post: 17 (16) mmHg; P = 0.048). In SHAM counterparts, neither drug affected the mechanoreflex responses. Our findings highlight PKCε, but not IP3 receptors, as a significant second-messenger in the chronic mechanoreflex sensitization in HF-rEF which may play a crucial role in the exaggerated sympathetic response to exercise in this patient population. KEY POINTS: Skeletal muscle contraction results in an exaggerated reflex increase in sympathetic nerve activity in heart failure patients with reduced ejection fraction (HF-rEF) compared to healthy individuals, contributing to increased cardiovascular risk and impaired tolerance for mild exercise. The exaggerated reflex sympathetic responses in HF-rEF may be attributed to a chronic sensitization of mechanically sensitive thin fibre muscle afferents mediated, at least in part, by stimulation of Gq protein-coupled thromboxane A2 and bradykinin B2 receptors on muscle afferent sensory endings. The specific Gq protein-linked signalling mechanisms that produce the chronic mechanoreflex sensitization in HF-rEF have not been investigated but may involve inositol 1,4,5-trisphosphate (IP3) receptors and/or protein kinase C epsilon (PKCε). Here we demonstrate that PKCε, but not IP3 receptors, within the sensory endings of thin fibre muscle afferents plays a role in the sensitization of mechanically sensitive thin fibre muscle afferents in rats with HF-rEF.

17.
J Physiol ; 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39258961

RESUMEN

There is evidence that aerobic exercise improves brain health. Benefits may be modulated by acute physiological responses to exercise, but this has not been well characterized in older or cognitively impaired adults. The randomized controlled trial 'AEROBIC' (NCT04299308) enrolled 60 older adults who were cognitively healthy (n = 30) or cognitively impaired (n = 30) to characterize the acute brain responses to moderate [45-55% heart rate reserve (HRR)] and higher (65-75% HRR) intensity acute exercise. Each participant received two fluorodeoxyglucose positron emission tomography (FDG-PET) scans, one at rest and one following acute exercise. Change in cerebral glucose metabolism from rest to exercise was the primary outcome. Blood biomarker responses were also characterized as secondary outcomes. Whole grey matter FDG-PET standardized uptake value ratio (SUVR) differed between exercise (1.045 ± 0.082) and rest (0.985 ± 0.077) across subjects [Diff = -0.060, t(58) = 13.8, P < 0.001] regardless of diagnosis. Exercise increased lactate area under the curve (AUC) [F(1,56) = 161.99, P < 0.001] more in the higher intensity group [mean difference (MD) = 97.0 ± 50.8] than the moderate intensity group (MD = 40.3 ± 27.5; t = -5.252, P < 0.001). Change in lactate AUC and FDG-PET SUVR correlated significantly (R2 = 0.179, P < 0.001). Acute exercise decreased whole grey matter cerebral glucose metabolism. This effect tracked with the systemic lactate response, suggesting that lactate may serve as a key brain fuel during exercise. Direct measurements of brain lactate metabolism in response to exercise are warranted. KEY POINTS: Acute exercise is associated with a drop in global brain glucose metabolism in both cognitively healthy older adults and those with Alzheimer's disease. Blood lactate levels increase following acute exercise. Change in brain metabolism tracks with blood lactate, suggesting it may be an important brain fuel. Acute exercise stimulates changes in brain-derived neurotrophic factor and other blood biomarkers.

18.
Clin Infect Dis ; 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39282957

RESUMEN

BACKGROUND: Prisons provide a key strategic opportunity to upscale hepatitis C testing and treatment in a high prevalence setting and are crucial for elimination efforts. METHODS: A decentralized, statewide nurse-led model of care offering hepatitis C treatment for people in prison was implemented in Victoria, Australia in 2015. The program provides hepatitis C care to all 14 adult prison sites in the jurisdiction. We prospectively evaluated treatment uptake between 1 November 2015 and 31 December 2021. Data on all people in prison treated were recorded in a clinical database. The primary outcomes were i) total number of people in prison with hepatitis C treated; ii) total number of DAA treatment courses. RESULTS: 3,133 DAA treatment courses were prescribed to 2,768 people in prison. The proportion of total Victoria DAA prescriptions the program was responsible for increased from 6% in 2016 to a peak of 23% in 2020. Of those treated, median age was 39 years, 91% were male and 9% had cirrhosis. Few (20%) had previously engaged in hepatitis C care in the community and at first treatment course in prison, only 6% had previously accessed hepatitis C treatment. Complete follow up data were available for 1,757/2,768 (63%) treated, with 1,627/1,757 (93%) achieving SVR12. CONCLUSIONS: A decentralized, nurse-led, statewide model of care was highly effective in treating large numbers of people in prison with hepatitis C and achieved high rates of SVR12. Nurse-led prison programs are playing a crucial role in eliminating hepatitis C as a public health threat in Australia.

19.
Ann Intern Med ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39284187

RESUMEN

BACKGROUND: Cardiovascular devices account for one third of all Class I recalls, the U.S. Food and Drug Administration's (FDA) most severe designation, indicating a reasonable probability of "serious adverse health consequences or death." Understanding recalls and their causes is important for patient safety. OBJECTIVE: To characterize Class I recalls of cardiovascular devices and the clinical evidence supporting authorization. DESIGN: In this cross-sectional study, cardiovascular device recalls from 1 January 2013 through 31 December 2022 were identified using the FDA's annual log. Information about devices was extracted from publicly available FDA decision summaries. SETTING: The FDA Medical Device Recalls database. PARTICIPANTS: Cardiovascular devices with Class I recalls. MEASUREMENTS: Recalls were characterized by their causes and scope. Devices were characterized by their regulatory history (product code, special designations) and clinical evidence (premarket testing, postmarket surveillance). Clinical studies were analyzed for quality, including end point selection (clinical vs. surrogate, use of composites). RESULTS: From 2013 to 2022, there were 137 Class I recall events affecting 157 unique cardiovascular devices, of which 112 (71.3%) were moderate-risk 510(k) devices and 45 (28.7%) were high-risk premarket approval (PMA) devices. Recalls affected a median of 7649 units (IQR, 953 to 28 446) and were most commonly attributed to device design (43 [31.4%]). Forty-two (26.8%) devices had multiple Class I recalls. Thirty (19.1%) devices underwent premarket clinical testing (7 [6.2%] 510(k) devices, 17 [85.0%] PMA devices, and 6 [24.0%] PMA supplement devices). Most studies used surrogate (27 [79.4%]) and composite (24 [70.6%]) measures as primary end points. Twenty-two (48.9%) PMA devices had required postapproval studies, with 14 reporting delays. No 510(k) devices were subject to postmarket surveillance. LIMITATION: Details about clinical testing may be missing from FDA summaries. CONCLUSION: Cardiovascular devices with Class I recalls were infrequently subjected to premarket or postmarket testing, with recalls affecting thousands of patients annually. PRIMARY FUNDING SOURCE: None.

20.
SLAS Discov ; 29(7): 100182, 2024 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-39245180

RESUMEN

The use of organoid models in biomedical research has grown substantially since their inception. As they gain popularity among scientists seeking more complex and biologically relevant systems, there is a direct need to expand and clarify potential uses of such systems in diverse experimental contexts. Herein we outline a high-content screening (HCS) platform that allows researchers to screen drugs or other compounds against three-dimensional (3D) cell culture systems in a multi-well format (384-well). Furthermore, we compare the quality of robotic liquid handling with manual pipetting and characterize and contrast the phenotypic effects detected by confocal imaging and biochemical assays in response to drug treatment. We show that robotic liquid handling is more consistent and amendable to high throughput experimental designs when compared to manual pipetting due to improved precision and automated randomization capabilities. We also show that image-based techniques are more sensitive to detecting phenotypic changes within organoid cultures than traditional biochemical assays that evaluate cell viability, supporting their integration into organoid screening workflows. Finally, we highlight the enhanced capabilities of confocal imaging in this organoid screening platform as they relate to discerning organoid drug responses in single-well co-cultures of organoids derived from primary human biopsies and patient-derived xenograft (PDX) models. Altogether, this platform enables automated, imaging-based HCS of 3D cellular models in a non-destructive manner, opening the path to complementary analysis through integrated downstream methods.

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