Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 665
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-38954792

RESUMEN

Objective: To review the effects of the ketogenic diet on epilepsy in children and adolescents.Data Sources: A literature search was conducted in PubMed with no publication date or language restrictions based on the Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines. Keywords used included children, adolescent, ketogenic diet, epilepsy, and seizure.Study Selection: After excluding articles that did not meet the inclusion criteria, such as missing variables of study, adult population, and nonrandomized clinical trials, a total of 12 studies were included in the final review.Data Extraction: Data on study design, duration, sample size, population, and type of intervention were collected using a standard template.Results: The ketogenic diet and its modified versions were noted to have beneficial effects in reduction of seizure frequency and severity, with manageable adverse effects such as gastrointestinal disturbances, dehydration, dyslipidemia, hyperuricemia, infection, and metabolic acidosis.Conclusions: Depending on patient compliance and comorbidities, all variations of the ketogenic diet were found to be helpful for seizure treatment, whether as an additive or an alternative treatment option, for children and adolescents with epilepsy.Prim Care Companion CNS Disord 2024;26(3):23r03661. Author affiliations are listed at the end of this article.


Asunto(s)
Dieta Cetogénica , Epilepsia , Humanos , Dieta Cetogénica/efectos adversos , Epilepsia/dietoterapia , Niño , Adolescente
2.
Front Mol Biosci ; 11: 1408767, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38962281

RESUMEN

Targeted delivery of medication has the promise of increasing the effectiveness and safety of current systemic drug treatments. Focused ultrasound is emerging as noninvasive and practical energy for targeted drug release. However, it has yet to be determined which nanocarriers and ultrasound parameters can provide both effective and safe release. Perfluorocarbon nanodroplets have the potential to achieve these goals, but current approaches have either been effective or safe, but not both. We found that nanocarriers with highly stable perfluorocarbon cores mediate effective drug release so long as they are activated by ultrasound of sufficiently low frequency. We demonstrate a favorable safety profile of this formulation in a non-human primate. To facilitate translation of this approach into humans, we provide an optimized method for manufacturing the nanocarriers. This study provides a recipe and release parameters for effective and safe drug release from nanoparticle carriers in the body part specified by focused ultrasonic waves.

3.
Front Hum Neurosci ; 18: 1412921, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38979100

RESUMEN

Transcranial focused ultrasound enables precise and non-invasive manipulations of deep brain circuits in humans, promising to provide safe and effective treatments of various neurological and mental health conditions. Ultrasound focused to deep brain targets can be used to modulate neural activity directly or localize the release of psychoactive drugs. However, these applications have been impeded by a key barrier-the human skull, which attenuates ultrasound strongly and unpredictably. To address this issue, we have developed an ultrasound-based approach that directly measures and compensates for the ultrasound attenuation by the skull. No additional skull imaging, simulations, assumptions, or free parameters are necessary; the method measures the attenuation directly by emitting a pulse of ultrasound from an array on one side of the head and measuring with an array on the opposite side. Here, we apply this emerging method to two primary future uses-neuromodulation and local drug release. Specifically, we show that the correction enables effective stimulation of peripheral nerves and effective release of propofol from nanoparticle carriers through an ex vivo human skull. Neither application was effective without the correction. Moreover, the effects show the expected dose-response relationship and targeting specificity. This article highlights the need for precise control of ultrasound intensity within the skull and provides a direct and practical approach for addressing this lingering barrier.

4.
J Inherit Metab Dis ; 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39038845

RESUMEN

ALDH7A1 deficiency is an epileptic encephalopathy whose seizures respond to treatment with supraphysiological doses of pyridoxine. It arises as a result of damaging variants in ALDH7A1, a gene in the lysine catabolism pathway. α-Aminoadipic semialdehyde (α-AASA) and Δ1-piperideine-6-carboxylate (P6C), which accumulate because of the block in the lysine pathway, are diagnostic biomarkers for this disorder. Recently, it has been reported that 6-oxo-pipecolic acid (6-oxo-PIP) also accumulates in the urine, CSF and plasma of ALDH7A1-deficient individuals and that, given its improved stability, it may be a more suitable biomarker for this disorder. This study measured 6-oxo-PIP in urine from a cohort of 30 patients where α-AASA was elevated and showed that it was above the normal range in all those above 6 months of age. However, 6-oxo-PIP levels were within the normal range in 33% of the patients below 6 months of age. Levels increased with age and correlated with a decrease in α-AASA levels. Longitudinal analysis of urine samples from ALDH7A1-deficient patients who were on a lysine restricted diet whilst receiving supraphysiological doses of pyridoxine showed that levels of 6-oxo-PIP remained elevated whilst α-AASA decreased. Similar to α-AASA, we found that elevated urinary excretion of 6-oxo-PIP can also occur in individuals with molybdenum cofactor deficiency. This study demonstrates that urinary 6-oxo-PIP may not be a suitable biomarker for ALDH7A1 deficiency in neonates. However, further studies are needed to understand the biochemistry leading to its accumulation and its potential long-term side effects.

5.
bioRxiv ; 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38948797

RESUMEN

Glycosylation-deficient Chinese hamster ovary (CHO) cell lines have been instrumental in the discovery of N-glycosylation machinery. Yet, the molecular causes of the glycosylation defects in the Lec5 and Lec9 mutants have been elusive, even though for both cell lines a defect in dolichol formation from polyprenol was previously established. We recently found that dolichol synthesis from polyprenol occurs in three steps consisting of the conversion of polyprenol to polyprenal by DHRSX, the reduction of polyprenal to dolichal by SRD5A3 and the reduction of dolichal to dolichol, again by DHRSX. This led us to investigate defective dolichol synthesis in Lec5 and Lec9 cells. Both cell lines showed increased levels of polyprenol and its derivatives, concomitant with decreased levels of dolichol and derivatives, but no change in polyprenal levels, suggesting DHRSX deficiency. Accordingly, N-glycan synthesis and changes in polyisoprenoid levels were corrected by complementation with human DHRSX but not with SRD5A3. Furthermore, the typical polyprenol dehydrogenase and dolichal reductase activities of DHRSX were absent in membrane preparations derived from Lec5 and Lec9 cells, while the reduction of polyprenal to dolichal, catalyzed by SRD5A3, was unaffected. Long-read whole genome sequencing of Lec5 and Lec9 cells did not reveal mutations in the ORF of SRD5A3, but the genomic region containing DHRSX was absent. Lastly, we established the sequence of Chinese hamster DHRSX and validated that this protein has similar kinetic properties to the human enzyme. Our work therefore identifies the basis of the dolichol synthesis defect in CHO Lec5 and Lec9 cells.

7.
Ophthalmic Plast Reconstr Surg ; 40(4): 408-410, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38967565

RESUMEN

PURPOSE: To assess the utility of a marginal full thickness blepharotomy (MFTB) for the treatment of orbital compartment syndrome. METHODS: An experimental study design employing a cadaver model for orbital compartment syndrome was used to assess the efficacy of an MFTB. Elevated orbital compartment pressures were created in 12 orbits of 6 fresh cadaver heads. Intraocular pressure, as an analog of orbital pressure, was measured before and after inferior and superior MFTBs were performed. Statistical analysis was performed on the collected data to assess the efficacy of the procedure. RESULTS: Both procedures were found to significantly lower the orbital compartment pressure. MFTB of the inferior lateral eyelid decreased orbital compartment pressure by an average of 62.2 mm Hg (95% CI, 56.9-67.5). MFTB of the superior lateral eyelid following MFTB of the inferior lateral eyelid decreased the orbital compartment pressure by an additional average of 10.3 mm Hg (total average reduction of 72.5 mm Hg; 95% CI, 68.1-76.9). CONCLUSIONS: Orbital compartment syndrome is a time-sensitive vision-threatening emergency that requires prompt diagnosis and intervention to prevent irreversible vision loss. The authors describe the MTFB, a simple one-step procedure that when performed correctly results in a significant decrease in orbital compartment pressure, making it a viable option when canthotomy and cantholysis fails or is unable to be performed.


Asunto(s)
Cadáver , Síndromes Compartimentales , Párpados , Presión Intraocular , Enfermedades Orbitales , Humanos , Síndromes Compartimentales/cirugía , Síndromes Compartimentales/diagnóstico , Síndromes Compartimentales/fisiopatología , Síndromes Compartimentales/etiología , Párpados/cirugía , Presión Intraocular/fisiología , Enfermedades Orbitales/cirugía , Enfermedades Orbitales/diagnóstico , Órbita/cirugía , Procedimientos Quirúrgicos Oftalmológicos/métodos
8.
Hemasphere ; 8(6): e87, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38873532

RESUMEN

Brexucabtagene autoleucel (brexu-cel) is an autologous CD19 CAR T-cell product, approved for relapsed/refractory (r/r) mantle cell lymphoma (MCL). In ZUMA-2, brexu-cel demonstrated impressive responses in patients failing ≥2 lines, including a bruton's tyrosine kinase inhibitor, with an overall and complete response rate of 93% and 67%, respectively. Here, we report our real-world intention-to-treat (ITT) outcomes for brexu-cel in consecutive, prospectively approved patients, from 12 institutions in the United Kingdom between February 2021 and June 2023, with a focus on feasibility, efficacy, and tolerability. Of 119 approved, 104 underwent leukapheresis and 83 received a brexu-cel infusion. Progressive disease (PD) and/or manufacturing (MF) were the most common reasons for failure to reach harvest and/or infusion. For infused patients, best overall and complete response rates were 87% and 81%, respectively. At a median follow-up of 13.3 months, median progression-free survival (PFS) for infused patients was 21 months (10.1-NA) with a 6- and 12-month PFS of 82% (95% confidence interval [CI], 71-89) and 62% (95% CI, 49-73), respectively. ≥Grade 3 cytokine release syndrome and neurotoxicity occurred in 12% and 22%, respectively. On multivariate analysis, inferior PFS was associated with male sex, bulky disease, ECOG PS > 1 and previous MF. Cumulative incidence of non-relapse mortality (NRM) was 6%, 15%, and 25% at 6, 12, and 24 months, respectively, and mostly attributable to infection. Outcomes for infused patients in the UK are comparable to ZUMA-2 and other real-world reports. However, ITT analysis highlights a significant dropout due to PD and/or MF. NRM events warrant further attention.

9.
Br J Hosp Med (Lond) ; 85(6): 1-9, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38941979

RESUMEN

Prompt diagnosis of lymphoma facilitates early treatment and improves outcomes for patients. For non-haemato-oncologists, it is important to have an understanding of how lymphoma can present and the initial work-up. This review is intended to provide clinicians with background to aid clinical decisional making at presentation and when managing treatment related complications. There will be particular emphasis on emergency presentations (tumour lysis syndrome, management of patients with a mediastinal mass, infections in lymphoma patients) and novel treatment options which have unique toxicities often requiring multi-specialty expertise.


Asunto(s)
Linfoma , Humanos , Linfoma/terapia , Linfoma/diagnóstico , Toma de Decisiones Clínicas , Síndrome de Lisis Tumoral/diagnóstico , Síndrome de Lisis Tumoral/terapia , Síndrome de Lisis Tumoral/etiología
10.
J Synchrotron Radiat ; 31(Pt 4): 888-895, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38838165

RESUMEN

Understanding the correlation between chemical and microstructural properties is critical for unraveling the fundamental relationship between materials chemistry and physical structures that can benefit materials science and engineering. Here, we demonstrate novel in situ correlative imaging of the X-ray Compton scattering computed tomography (XCS-CT) technique for studying this fundamental relationship. XCS-CT can image light elements that do not usually exhibit strong signals using other X-ray characterization techniques. This paper describes the XCS-CT setup and data analysis method for calculating the valence electron momentum density and lithium-ion concentration, and provides two examples of spatially and temporally resolved chemical properties inside batteries in 3D. XCS-CT was applied to study two types of rechargeable lithium batteries in standard coin cell casings: (1) a lithium-ion battery containing a cathode of bespoke microstructure and liquid electrolyte, and (2) a solid-state battery containing a solid-polymer electrolyte. The XCS-CT technique is beneficial to a wide variety of materials and systems to map chemical composition changes in 3D structures.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38837925

RESUMEN

Accurately capturing dynamic scenes with wideranging motion and light intensity is crucial for many vision applications. However, acquiring high-speed high dynamic range (HDR) video is challenging because the camera's frame rate restricts its dynamic range. Existing methods sacrifice speed to acquire multi-exposure frames. Yet, misaligned motion in these frames can still pose complications for HDR fusion algorithms, resulting in artifacts. Instead of frame-based exposures, we sample the videos using individual pixels at varying exposures and phase offsets. Implemented on a monochrome pixel-wise programmable image sensor, our sampling pattern captures fast motion at a high dynamic range. We then transform pixel-wise outputs into an HDR video using end-to-end learned weights from deep neural networks, achieving high spatiotemporal resolution with minimized motion blurring. We demonstrate aliasing-free HDR video acquisition at 1000 FPS, resolving fast motion under low-light conditions and against bright backgrounds - both challenging conditions for conventional cameras. By combining the versatility of pixel-wise sampling patterns with the strength of deep neural networks at decoding complex scenes, our method greatly enhances the vision system's adaptability and performance in dynamic conditions.

13.
Bone Jt Open ; 5(6): 514-523, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38910515

RESUMEN

Aims: In metal-on-metal (MoM) hip arthroplasties and resurfacings, mechanically induced corrosion can lead to elevated serum metal ions, a local inflammatory response, and formation of pseudotumours, ultimately requiring revision. The size and diametral clearance of anatomical (ADM) and modular (MDM) dual-mobility polyethylene bearings match those of Birmingham hip MoM components. If the acetabular component is satisfactorily positioned, well integrated into the bone, and has no surface damage, this presents the opportunity for revision with exchange of the metal head for ADM/MDM polyethylene bearings without removal of the acetabular component. Methods: Between 2012 and 2020, across two centres, 94 patients underwent revision of Birmingham MoM hip arthroplasties or resurfacings. Mean age was 65.5 years (33 to 87). In 53 patients (56.4%), the acetabular component was retained and dual-mobility bearings were used (DM); in 41 (43.6%) the acetabulum was revised (AR). Patients underwent follow-up of minimum two-years (mean 4.6 (2.1 to 8.5) years). Results: In the DM group, two (3.8%) patients underwent further surgery: one (1.9%) for dislocation and one (1.9%) for infection. In the AR group, four (9.8%) underwent further procedures: two (4.9%) for loosening of the acetabular component and two (4.9%) following dislocations. There were no other dislocations in either group. In the DM group, operating time (68.4 vs 101.5 mins, p < 0.001), postoperative drop in haemoglobin (16.6 vs 27.8 g/L, p < 0.001), and length of stay (1.8 vs 2.4 days, p < 0.001) were significantly lower. There was a significant reduction in serum metal ions postoperatively in both groups (p < 0.001), although there was no difference between groups for this reduction (p = 0.674 (cobalt); p = 0.186 (chromium)). Conclusion: In selected patients with Birmingham MoM hips, where the acetabular component is well-fixed and in a satisfactory position with no surface damage, the metal head can be exchanged for polyethylene ADM/MDM bearings with retention of the acetabular prosthesis. This presents significant benefits, with a shorter procedure and a lower risk of complications.

14.
Am J Hosp Palliat Care ; : 10499091241252058, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38725412

RESUMEN

BACKGROUND: Gaps in communication of end-of-life care preferences increase risk of patient harm. Adoption of oncology practice guidelines advocating serious illness communication for patients with advanced cancer is limited. OBJECTIVES: (1) Increase Serious Illness Conversation (SIC) use across oncology teams via an interdisciplinary quality improvement (QI) approach and (2) assess patient reported shared decision making (SDM) experiences with clinicians engaged in SIC implementation. DESIGN: QI methodology was applied to spread the implementation of SIC across 4 oncology teams. CollaboRATE scores were used to evaluate patient reported outcomes of SDM for patients with advanced cancer. SETTINGS/SUBJECTS: The SIC QI initiative was a component of the Promise Partnership Learning Health System (PPLHS) piloted in the Dartmouth Cancer Center, Lebanon, NH, USA. MEASUREMENTS: (1) The percentage of eligible patients with documented SIC and (2) a comparison of a patient reported measure of SDM (CollaboRATE) among SIC eligible patients in encounters with providers who took part in the implementation versus those who did not. RESULTS: Oncology teams screened a total of 538 patients, identified 278 eligible patients, and completed 144 SIC conversations. The teams improved the proportion of documented SIC among eligible patients from near 0% to a collective frequency of 52%. For clinicians' top-box CollaboRATE scores, a chi-squared test demonstrated a statistically significant association between providers implementing SIC into practice and patient reported shared decision making (.16, p = .031). CONCLUSIONS: This approach allows for tailoring of iterative improvement cycles to mitigate barriers and improve the practice of SIC among oncology teams.

15.
Nat Biotechnol ; 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38744947

RESUMEN

Cancer immunotherapy with autologous chimeric antigen receptor (CAR) T cells faces challenges in manufacturing and patient selection that could be avoided by using 'off-the-shelf' products, such as allogeneic CAR natural killer T (AlloCAR-NKT) cells. Previously, we reported a system for differentiating human hematopoietic stem and progenitor cells into AlloCAR-NKT cells, but the use of three-dimensional culture and xenogeneic feeders precluded its clinical application. Here we describe a clinically guided method to differentiate and expand IL-15-enhanced AlloCAR-NKT cells with high yield and purity. We generated AlloCAR-NKT cells targeting seven cancers and, in a multiple myeloma model, demonstrated their antitumor efficacy, expansion and persistence. The cells also selectively depleted immunosuppressive cells in the tumor microenviroment and antagonized tumor immune evasion via triple targeting of CAR, TCR and NK receptors. They exhibited a stable hypoimmunogenic phenotype associated with epigenetic and signaling regulation and did not induce detectable graft versus host disease or cytokine release syndrome. These properties of AlloCAR-NKT cells support their potential for clinical translation.

16.
Colorectal Dis ; 26(6): 1271-1284, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38750621

RESUMEN

AIM: Although proximal faecal diversion is standard of care to protect patients with high-risk colorectal anastomoses against septic complications of anastomotic leakage, it is associated with significant morbidity. The Colovac device (CD) is an intraluminal bypass device intended to avoid stoma creation in patients undergoing low anterior resection. A preliminary study (SAFE-1) completed in three European centres demonstrated 100% protection of colorectal anastomoses in 15 patients, as evidenced by the absence of faeces below the CD. This phase III trial (SAFE-2) aims to evaluate the safety and effectiveness of the CD in a larger cohort of patients undergoing curative rectal cancer resection. METHODS: SAFE-2 is a pivotal, multicentre, prospective, open-label, randomized, controlled trial. Patients will be randomized in a 1:1 ratio to either the CD arm or the diverting loop ileostomy arm, with a recruitment target of 342 patients. The co-primary endpoints are the occurrence of major postoperative complications within 12 months of index surgery and the effectiveness of the CD in reducing stoma creation rates. Data regarding quality of life and patient's acceptance and tolerance of the device will be collected. DISCUSSION: SAFE-2 is a multicentre randomized, control trial assessing the efficacy and the safety of the CD in protecting low colorectal anastomoses created during oncological resection relative to standard diverting loop ileostomy. TRIAL REGISTRATION: NCT05010850.


Asunto(s)
Anastomosis Quirúrgica , Fuga Anastomótica , Colon , Neoplasias del Recto , Recto , Humanos , Anastomosis Quirúrgica/instrumentación , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Fuga Anastomótica/prevención & control , Estudios Prospectivos , Neoplasias del Recto/cirugía , Recto/cirugía , Colon/cirugía , Femenino , Masculino , Resultado del Tratamiento , Ileostomía/instrumentación , Ileostomía/efectos adversos , Ileostomía/métodos , Persona de Mediana Edad , Calidad de Vida , Adulto , Anciano , Proctectomía/efectos adversos , Proctectomía/métodos , Proctectomía/instrumentación , Complicaciones Posoperatorias/prevención & control
17.
Cell ; 187(14): 3585-3601.e22, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38821050

RESUMEN

Dolichol is a lipid critical for N-glycosylation as a carrier for activated sugars and nascent oligosaccharides. It is commonly thought to be directly produced from polyprenol by the enzyme SRD5A3. Instead, we found that dolichol synthesis requires a three-step detour involving additional metabolites, where SRD5A3 catalyzes only the second reaction. The first and third steps are performed by DHRSX, whose gene resides on the pseudoautosomal regions of the X and Y chromosomes. Accordingly, we report a pseudoautosomal-recessive disease presenting as a congenital disorder of glycosylation in patients with missense variants in DHRSX (DHRSX-CDG). Of note, DHRSX has a unique dual substrate and cofactor specificity, allowing it to act as a NAD+-dependent dehydrogenase and as a NADPH-dependent reductase in two non-consecutive steps. Thus, our work reveals unexpected complexity in the terminal steps of dolichol biosynthesis. Furthermore, we provide insights into the mechanism by which dolichol metabolism defects contribute to disease.


Asunto(s)
Dolicoles , Dolicoles/metabolismo , Dolicoles/biosíntesis , Humanos , Glicosilación , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Deshidrogenasa/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Trastornos Congénitos de Glicosilación/metabolismo , Trastornos Congénitos de Glicosilación/genética , Masculino , Mutación Missense , Femenino
18.
Cureus ; 16(4): e58950, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38800302

RESUMEN

BACKGROUND: This study aims to compare the performance of ChatGPT-3.5 (GPT-3.5) and ChatGPT-4 (GPT-4) on the American Society for Surgery of the Hand (ASSH) Self-Assessment Examination (SAE) to determine their potential as educational tools. METHODS: This study assessed the proportion of correct answers to text-based questions on the 2021 and 2022 ASSH SAE between untrained ChatGPT versions. Secondary analyses assessed the performance of ChatGPT based on question difficulty and question category. The outcomes of ChatGPT were compared with the performance of actual examinees on the ASSH SAE. RESULTS: A total of 238 questions were included in the analysis. Compared with GPT-3.5, GPT-4 provided significantly more correct answers overall (58.0% versus 68.9%, respectively; P = 0.013), on the 2022 SAE (55.9% versus 72.9%; P = 0.007), and more difficult questions (48.8% versus 63.6%; P = 0.02). In a multivariable logistic regression analysis, correct answers were predicted by GPT-4 (odds ratio [OR], 1.66; P = 0.011), increased question difficulty (OR, 0.59; P = 0.009), Bone and Joint questions (OR, 0.18; P < 0.001), and Soft Tissue questions (OR, 0.30; P = 0.013). Actual examinees scored a mean of 21.6% above GPT-3.5 and 10.7% above GPT-4. The mean percentage of correct answers by actual examinees was significantly higher for correct (versus incorrect) ChatGPT answers. CONCLUSIONS: GPT-4 demonstrated improved performance over GPT-3.5 on the ASSH SAE, especially on more difficult questions. Actual examinees scored higher than both versions of ChatGPT, but the margin was cut in half by GPT-4.

19.
Nat Commun ; 15(1): 4480, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38802338

RESUMEN

High-speed wide-field fluorescence microscopy has the potential to capture biological processes with exceptional spatiotemporal resolution. However, conventional cameras suffer from low signal-to-noise ratio at high frame rates, limiting their ability to detect faint fluorescent events. Here, we introduce an image sensor where each pixel has individually programmable sampling speed and phase, so that pixels can be arranged to simultaneously sample at high speed with a high signal-to-noise ratio. In high-speed voltage imaging experiments, our image sensor significantly increases the output signal-to-noise ratio compared to a low-noise scientific CMOS camera (~2-3 folds). This signal-to-noise ratio gain enables the detection of weak neuronal action potentials and subthreshold activities missed by the standard scientific CMOS cameras. Our camera with flexible pixel exposure configurations offers versatile sampling strategies to improve signal quality in various experimental conditions.


Asunto(s)
Microscopía Fluorescente , Relación Señal-Ruido , Microscopía Fluorescente/métodos , Microscopía Fluorescente/instrumentación , Animales , Neuronas/fisiología , Potenciales de Acción/fisiología , Procesamiento de Imagen Asistido por Computador/métodos , Ratones , Humanos
20.
bioRxiv ; 2024 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-38766068

RESUMEN

BACKGROUND: Deep brain stimulation of central thalamus (CT-DBS) has potential for modulating states of consciousness, but it can also trigger spike-wave discharges (SWDs). OBJECTIVES: To report the probability of inducing SWDs during CT-DBS in awake mice. METHODS: Mice were implanted with electrodes to deliver unilateral and bilateral CT-DBS at different frequencies while recording EEG. We titrated stimulation current by gradually increasing it at each frequency until an SWD appeared. Subsequent stimulations to test arousal modulation were performed at the current one step below the current that caused an SWD during titration. RESULTS: In 2.21% of the test stimulations (10 out of 12 mice), CT-DBS caused SWDs at currents lower than the titrated current, at currents as low as 20 uA. CONCLUSION: Our study found a small but significant probability of inducing SWDs even after titration and at relatively low currents. EEG should be closely monitored for SWDs when performing CT-DBS in both research and clinical settings.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...