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1.
Proc Natl Acad Sci U S A ; 118(20)2021 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-33972441

RESUMEN

Neuromodulation of immune function by stimulating the autonomic connections to the spleen has been demonstrated in rodent models. Consequently, neuroimmune modulation has been proposed as a new therapeutic strategy for the treatment of inflammatory conditions. However, demonstration of the translation of these immunomodulatory mechanisms in anatomically and physiologically relevant models is still lacking. Additionally, translational models are required to identify stimulation parameters that can be transferred to clinical applications of bioelectronic medicines. Here, we performed neuroanatomical and functional comparison of the mouse, rat, pig, and human splenic nerve using in vivo and ex vivo preparations. The pig was identified as a more suitable model of the human splenic innervation. Using functional electrophysiology, we developed a clinically relevant marker of splenic nerve engagement through stimulation-dependent reversible reduction in local blood flow. Translation of immunomodulatory mechanisms were then assessed using pig splenocytes and two models of acute inflammation in anesthetized pigs. The pig splenic nerve was shown to locally release noradrenaline upon stimulation, which was able to modulate cytokine production by pig splenocytes. Splenic nerve stimulation was found to promote cardiovascular protection as well as cytokine modulation in a high- and a low-dose lipopolysaccharide model, respectively. Importantly, splenic nerve-induced cytokine modulation was reproduced by stimulating the efferent trunk of the cervical vagus nerve. This work demonstrates that immune responses can be modulated by stimulation of spleen-targeted autonomic nerves in translational species and identifies splenic nerve stimulation parameters and biomarkers that are directly applicable to humans due to anatomical and electrophysiological similarities.


Asunto(s)
Sistema Inmunológico/inervación , Inmunomodulación/efectos de los fármacos , Bazo/inmunología , Sistema Nervioso Simpático/inmunología , Nervio Vago/inmunología , Animales , Femenino , Expresión Génica , Humanos , Sistema Inmunológico/efectos de los fármacos , Inflamación , Interleucina-6/genética , Interleucina-6/inmunología , Lipopolisacáridos/farmacología , Ratones , Microcirculación/efectos de los fármacos , Microcirculación/genética , Microcirculación/inmunología , Norepinefrina/farmacología , Ratas , Especificidad de la Especie , Bazo/efectos de los fármacos , Bazo/inervación , Bazo/patología , Porcinos , Sistema Nervioso Simpático/efectos de los fármacos , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología , Nervio Vago/efectos de los fármacos , Estimulación del Nervio Vago/métodos
2.
Exp Physiol ; 108(2): 280-295, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36459572

RESUMEN

NEW FINDINGS: What is the central question of this study? What are the effects of insulin and insulin-induced hypoglycaemia on carotid body chemoreceptor activity in vivo and how do carotid body chemoreceptor stimulation-mediated cardiorespiratory responses in beagle dogs compare during euglycaemia and insulin-induced hypoglycaemia? What is the main finding and its importance? Intracarotid insulin administration leads to sustained increase in carotid body chemoreceptor activity and respiratory response with significant cardiovascular effects. Insulin-induced hypoglycaemia exacerbated NaCN-mediated carotid body chemoreceptor activity and respiratory response with enhanced cardiovascular reflex response. These findings suggest that insulin-induced hypoglycaemia augments the carotid body chemoreceptors to initiate the adaptive counter-regulatory responses to restore the normoglycaemic condition. ABSTRACT: The carotid body chemoreceptors (CBC) play an important role in the adaptive counter-regulatory response to hypoglycaemia by evoking the CBC-mediated sympathetic neuronal system to restore normoglycaemia. Ex vivo studies have shown varied responses of insulin-induced hypoglycaemia on CBC function, and several in vivo studies have indirectly established the role of CBCs in restoring normoglycaemia in both animals and humans. However, a direct effect of insulin and/or insulin-induced hypoglycaemia on CBC activity is not established in animal models. Therefore, the aim of this study was to evaluate in vivo effects of insulin and insulin-induced hypoglycaemia on CBC activity and cardiorespiration in a preclinical large animal model. The carotid sinus nerve (CSN) activity and cardiorespiratory responses to sodium cyanide (NaCN; 25 µg/kg) were compared before (euglycaemic) and after (hypoglycaemic) intracarotid administration of insulin (12.5-100 µU/dogs) in beagle dogs. Insulin administration increased CSN activity and minute ventilation ( V ̇ $\dot V$ E ) with significant (P < 0.0001) effects on heart rate and blood pressure. Insulin-mediated effects on CSN and cardiorespiration were sustained and the change in V ̇ $\dot V$ E was driven by tidal volume only. Insulin significantly (P < 0.0001) lowered blood glucose level. NaCN-mediated CSN activity and V ̇ $\dot V$ E were significantly (P < 0.0001) augmented during insulin-induced hypoglycaemia. The augmented V ̇ $\dot V$ E was primarily driven by respiratory frequency and partially by tidal volume. The cardiovascular reflex response mediated through CBC stimulation was significantly (P < 0.0001) exacerbated during insulin-induced hypoglycaemia. Collectively, these results demonstrate direct effects of insulin and insulin-induced hypoglycaemia on CBC chemosensitivity to potentiate CBC-mediated neuroregulatory pathways to initiate adaptive neuroendocrine and cardiorespiratory counter-regulatory responses to restore normoglycaemia.


Asunto(s)
Cuerpo Carotídeo , Hipoglucemia , Humanos , Perros , Animales , Cuerpo Carotídeo/metabolismo , Insulina/metabolismo , Células Quimiorreceptoras/fisiología , Reflejo , Presión Sanguínea
3.
Int Wound J ; 20(5): 1609-1621, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36372913

RESUMEN

Diabetic Foot in Primary and Tertiary (DEFINITE) Care is an inter-institutional and multi-disciplinary team (MDT) health systems innovation programme at a healthcare cluster in Singapore. We aim to achieve coordinated MDT care across primary and tertiary care for patients with diabetic foot ulcers (DFU), within our public healthcare cluster - an integrated network of seven primary care polyclinics and two acute care tertiary hospitals (1700-bed and 800-bed) with a total catchment population of 2.2 million residents. Results from prospective DEFINITE Care is referenced against a retrospective 2013-2017 cohort, which was previously published. Cardiovascular profile of the study population is compared against the same population's profile in the preceding 12 months. Between June 2020 and December 2021, there were 3475 unique patients with DFU with mean age at 65.9 years, 61.2% male, mean baseline HbA1c at 8.3% with mean diabetes duration at 13.3 years, mean diabetes complication severity index (DCSI) at 5.6 and mean Charlson Comorbidity Index (CCI) at 6.8. In the 12-months preceding enrolment to DEFINITE Care, 35.5% had surgical foot debridement, 21.2% had minor lower extremity amputation (LEA), 7.5% had major LEA whilst 16.8% had revascularisation procedures. At 18-months after the implementation of DEFINITE Care programme, the absolute minor and major amputation rates were 8.7% (n = 302) and 5.1% (n = 176), respectively, equating to a minor and major LEA per 100000 population at 13.7 and 8.0, respectively. This represents an 80% reduction in minor amputation rates (P < .001) and a 35% reduction in major amputation rates (P = .005) when referenced against a retrospective 2013-2017 cohort, which had minor and major LEA per 100000 population at 68.9 and 12.4, respectively. As compared to the preceding 12 months, there was also a significant improvement in cardiovascular profile (glycemic and lipid control) within the DEFINITE population, with improved mean HbAc1 (7.9% from 8.4%, P < .001), low-density lipoprotein (LDL) levels (2.1 mmol/L from 2.2, P < .001), total cholesterol (3.9 mmol/L from 4.1, P < .001) and triglycerides levels (1.6 mmol/L from 1.8, P = .002). Multivariate analysis revealed a history of minor amputation in the preceding 12 months to be an independent predictor for major and minor amputation within the study period of 18 months (Hazard Ratio 3.4 and 1.8, respectively, P < .001). In conclusion, within DEFINITE care, 18-month data showed a significant reduction of minor and major LEA rates, with improved medical optimisation and cardiovascular profile within the study population.


Asunto(s)
Diabetes Mellitus , Pie Diabético , Anciano , Femenino , Humanos , Masculino , Estudios de Cohortes , Pie Diabético/cirugía , Servicios de Salud , Estudios Prospectivos , Estudios Retrospectivos , Atención Terciaria de Salud
4.
Int Wound J ; 19(4): 765-773, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34363329

RESUMEN

Present guidelines recommend a multidisciplinary team (MDT) approach to diabetic foot ulcer (DFU) care, but relevant data from Asia are lacking. We aim to evaluate the clinical and economic outcomes of an MDT approach in a lower extremity amputation prevention programme (LEAPP) for DFU care in an Asian population. We performed a case-control study of 84 patients with DFU between January 2017 and October 2017 (retrospective control) vs 117 patients with DFU between December 2017 and July 2018 (prospective LEAPP cohort). Comparing the clinical outcomes between the retrospective cohort and the LEAPP cohort, there was a significant decrease in mean time from referral to index clinic visit (38.6 vs 9.5 days, P < .001), increase in outpatient podiatry follow-up (33% vs 76%, P < .001), decrease in 1-year minor amputation rate (14% vs 3%, P = .007), and decrease in 1-year major amputation rate (9% vs 3%, P = .05). Simulation of cost avoidance demonstrated an annualised cost avoidance of USD $1.86m (SGD $2.5m) for patients within the LEAPP cohort. In conclusion, similar to the data from Western societies, an MDT approach in an Asian population, via a LEAPP for patients with DFU, demonstrated a significant reduction in minor and major amputation rates, with annualised cost avoidance of USD $1.86m.


Asunto(s)
Diabetes Mellitus , Pie Diabético , Úlcera del Pie , Amputación Quirúrgica , Estudios de Casos y Controles , Pie Diabético/prevención & control , Pie Diabético/cirugía , Humanos , Extremidad Inferior , Grupo de Atención al Paciente , Estudios Prospectivos , Estudios Retrospectivos
5.
Horm Metab Res ; 53(3): 191-196, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33530117

RESUMEN

Singapore currently has one of highest number of confirmed COVID-19 cases in Southeast Asia. To curb the further spread of COVID-19, Singapore government announced a temporary nationwide lockdown (circuit breaker). In view of restrictions of patients' mobility and the enforcement of safe distancing measures, usual in-person visits were discouraged. Here we describe how diabetes care delivery was ad hoc redesigned applying a telehealth strategy. We describe a retrospective assessment of subjects with diabetes, with and without COVID-19 infection, during the circuit breaker period of 7th April to 1st June 2020 managed through Tan Tock Seng Hospital's telehealth platform. The virtual health applications consisted of telephone consultations, video telehealth visits via smartphones, and remote patient monitoring. The TTSH team intensively managed 298 diabetes patients using a telehealth strategy. The group comprised of (1) 84 inpatient COVID-19 patients with diabetes who received virtual diabetes education and blood glucose management during their hospitalisation and follow-up via phone calls after discharge and (2) 214 (n=192 non-COVID; n=22 COVID-positive) outpatient subjects with suboptimal glycaemic control who received intensive diabetes care through telehealth approaches. Remote continuous glucose monitoring was applied in 80 patients to facilitate treatment adjustment and hypoglycaemia prevention. The COVID-19 pandemic situation mooted an immediate disruptive transformation of healthcare processes. Virtual health applications were found to be safe, effective and efficient to replace current in-person visits.


Asunto(s)
COVID-19 , Diabetes Mellitus , SARS-CoV-2/metabolismo , Telemedicina , Automonitorización de la Glucosa Sanguínea , COVID-19/sangre , COVID-19/epidemiología , COVID-19/terapia , Diabetes Mellitus/sangre , Diabetes Mellitus/epidemiología , Diabetes Mellitus/terapia , Femenino , Humanos , Masculino , Pandemias , Singapur/epidemiología
6.
Bioinformatics ; 35(4): 688-690, 2019 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-30101321

RESUMEN

SUMMARY: Many eukaryotic proteins are modified by N-glycans. Liquid chromatography (ultra-performance -UPLC and high-performance-HPLC) coupled with mass spectrometry (MS) is conventionally used to characterize N-glycan structures. Software can automatically assign glycan structures by matching their observed retention times and masses with standardized values in reference databases. However, more precise confirmation of N-glycan structures can be derived using exoglycosidases, enzymes that remove specific monosaccharides from glycans. Exoglycosidase removal of monosaccharides results in signature peak shifts, in both UPLC and MS1, yielding an effective way to verify N-glycan structure with high detail (down to the position and isomeric linkage of each monosaccharide). Because manual interpretation of exoglycosidase data is complex and time consuming, we developed GlycanAnalyzer, a web application that pattern matches N-glycan peak shifts following exoglycosidase digestion and automates structure assignments. GlycanAnalyzer significantly improves assignment accuracy over other auto-assignment methods on tests with a monoclonal antibody and four glycan standards (100% versus 82% for the next best software). By automating data interpretation, GlycanAnalyzer enables the easier use of exoglycosidases to precisely define N-glycan structure. AVAILABILITY AND IMPLEMENTATION: http://glycananalyzer.neb.com. Datasets available online. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Glicósido Hidrolasas/química , Polisacáridos/química , Programas Informáticos , Cromatografía Líquida de Alta Presión , Internet , Espectrometría de Masas
7.
Ann Fam Med ; 18(2): 139-147, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32152018

RESUMEN

PURPOSE: We aimed to evaluate the efficacy and safety of use of the Fasting Algorithm for Singaporeans with Type 2 Diabetes (FAST) during Ramadan. METHODS: We performed a prospective, multicenter, randomized controlled trial. The inclusion criteria were age ≥21 years, baseline glycated hemoglobin (HbA1c) level ≤9.5%, and intention to fast for ≥10 days during Ramadan. Exclusion criteria included baseline estimated glomerular filtration rate <30 mL/min, diabetes-related hospitalization, and short-term corticosteroid therapy. Participants were randomized to intervention (use of FAST) or control (usual care without FAST) groups. Efficacy outcomes were HbA1c level and fasting blood glucose and postprandial glucose changes, and the safety outcome was incidence of major or minor hypoglycemia during the Ramadan period. Glycemic variability and diabetes distress were also investigated. Linear mixed models were constructed to assess changes. RESULTS: A total of 97 participants were randomized (intervention: n = 46, control: n = 51). The HbA1c improvement during Ramadan was 4 times greater in the intervention group (-0.4%) than in the control group (-0.1%) (P = .049). The mean fasting blood glucose level decreased in the intervention group (-3.6 mg/dL) and increased in the control group (+20.9 mg/dL) (P = .034). The mean postprandial glucose level showed greater improvement in the intervention group (-16.4 mg/dL) compared to the control group (-2.3 mg/dL). There were more minor hypoglycemic events based on self-monitered blood glucose readings in the control group (intervention: 4, control: 6; P = .744). Glycemic variability was not significantly different between the 2 groups (P = .284). No between-group differences in diabetes distress were observed (P = .479). CONCLUSIONS: Our findings emphasize the importance of efficacious, safe, and culturally tailored epistemic tools for diabetes management.


Asunto(s)
Algoritmos , Diabetes Mellitus Tipo 2/terapia , Ayuno , Islamismo , Anciano , Glucemia/análisis , Femenino , Hemoglobina Glucada/análisis , Humanos , Hipoglucemia/epidemiología , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Singapur
8.
Diabetologia ; 61(3): 700-710, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29332196

RESUMEN

AIMS/HYPOTHESIS: A new class of treatments termed bioelectronic medicines are now emerging that aim to target individual nerve fibres or specific brain circuits in pathological conditions to repair lost function and reinstate a healthy balance. Carotid sinus nerve (CSN) denervation has been shown to improve glucose homeostasis in insulin-resistant and glucose-intolerant rats; however, these positive effects from surgery appear to diminish over time and are heavily caveated by the severe adverse effects associated with permanent loss of chemosensory function. Herein we characterise the ability of a novel bioelectronic application, classified as kilohertz frequency alternating current (KHFAC) modulation, to suppress neural signals within the CSN of rodents. METHODS: Rats were fed either a chow or high-fat/high-sucrose (HFHSu) diet (60% lipid-rich diet plus 35% sucrose drinking water) over 14 weeks. Neural interfaces were bilaterally implanted in the CSNs and attached to an external pulse generator. The rats were then randomised to KHFAC or sham modulation groups. KHFAC modulation variables were defined acutely by respiratory and cardiac responses to hypoxia (10% O2 + 90% N2). Insulin sensitivity was evaluated periodically through an ITT and glucose tolerance by an OGTT. RESULTS: KHFAC modulation of the CSN, applied over 9 weeks, restored insulin sensitivity (constant of the insulin tolerance test [KITT] HFHSu sham, 2.56 ± 0.41% glucose/min; KITT HFHSu KHFAC, 5.01 ± 0.52% glucose/min) and glucose tolerance (AUC HFHSu sham, 1278 ± 20.36 mmol/l × min; AUC HFHSu KHFAC, 1054.15 ± 62.64 mmol/l × min) in rat models of type 2 diabetes. Upon cessation of KHFAC, insulin resistance and glucose intolerance returned to normal values within 5 weeks. CONCLUSIONS/INTERPRETATION: KHFAC modulation of the CSN improves metabolic control in rat models of type 2 diabetes. These positive outcomes have significant translational potential as a novel therapeutic modality for the purpose of treating metabolic diseases in humans.


Asunto(s)
Seno Carotídeo/inervación , Diabetes Mellitus Tipo 2/sangre , Animales , Glucemia/metabolismo , Péptido C/sangre , Corticosterona/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Electromiografía , Insulina/sangre , Resistencia a la Insulina/fisiología , Masculino , Óxido Nítrico/sangre , Pletismografía , Ratas
9.
J Neurosci ; 36(27): 7283-97, 2016 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-27383601

RESUMEN

UNLABELLED: After CNS injury, axon regeneration is blocked by an inhibitory environment consisting of the highly upregulated tenascin-C and chondroitin sulfate proteoglycans (CSPGs). Tenascin-C promotes growth of axons if they express a tenascin-binding integrin, particularly α9ß1. Additionally, integrins can be inactivated by CSPGs, and this inhibition can be overcome by the presence of a ß1-binding integrin activator, kindlin-1. We examined the synergistic effect of α9 integrin and kindlin-1 on sensory axon regeneration in adult rat spinal cord after dorsal root crush and adeno-associated virus transgene expression in dorsal root ganglia. After 12 weeks, axons from C6-C7 dorsal root ganglia regenerated through the tenascin-C-rich dorsal root entry zone into the dorsal column up to C1 level and above (>25 mm axon length) through a normal pathway. Animals also showed anatomical and electrophysiological evidence of reconnection to the dorsal horn and behavioral recovery in mechanical pressure, thermal pain, and ladder-walking tasks. Expression of α9 integrin or kindlin-1 alone promoted much less regeneration and recovery. SIGNIFICANCE STATEMENT: The study demonstrates that long-distance sensory axon regeneration over a normal pathway and with sensory and sensory-motor recovery can be achieved. This was achieved by expressing an integrin that recognizes tenascin-C, one of the components of glial scar tissue, and an integrin activator. This enabled extensive long-distance (>25 mm) regeneration of both myelinated and unmyelinated sensory axons with topographically correct connections in the spinal cord. The extent of growth and recovery we have seen would probably be clinically significant. Restoration of sensation to hands, perineum, and genitalia would be a significant improvement for a spinal cord-injured patient.


Asunto(s)
Axones/fisiología , Regulación de la Expresión Génica/fisiología , Integrinas/metabolismo , Regeneración Nerviosa/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Médula Espinal/citología , Animales , Péptido Relacionado con Gen de Calcitonina/metabolismo , Células Cultivadas , Proteoglicanos Tipo Condroitín Sulfato/metabolismo , Modelos Animales de Enfermedad , Femenino , Lateralidad Funcional , Ganglios Espinales/citología , Integrinas/genética , Proteínas del Tejido Nervioso/metabolismo , Neuritas/fisiología , Presión , Ratas , Ratas Sprague-Dawley , Caminata/fisiología
10.
Neurourol Urodyn ; 35(3): 365-70, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25663151

RESUMEN

AIMS: In this review, we focus on the current attempts of electrical nerve stimulation for micturition in spinal cord injury (SCI) patients. METHODS: A literature search was performed through PubMed using "spinal cord injury," "electrical nerve stimulation AND bladder," "sacral anterior root stimulation/stimulator" and "Brindley stimulator" from January 1975 to January 2014. RESULTS: Twenty studies were selected for this review. CONCLUSION: Electrical nerve stimulation is a clinical option for promoting micturition in SCI patients. Well-designed, randomized and controlled studies are essential for further investigation.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Traumatismos de la Médula Espinal/terapia , Vejiga Urinaria Neurogénica/terapia , Vejiga Urinaria/inervación , Micción , Terapia por Estimulación Eléctrica/instrumentación , Humanos , Neuroestimuladores Implantables , Recuperación de la Función , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/diagnóstico , Traumatismos de la Médula Espinal/fisiopatología , Resultado del Tratamiento , Vejiga Urinaria Neurogénica/diagnóstico , Vejiga Urinaria Neurogénica/etiología , Vejiga Urinaria Neurogénica/fisiopatología
11.
Urol Int ; 96(3): 360-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26953816

RESUMEN

INTRODUCTION: Using a rat model, we aimed to confirm the inhibitory effect of dorsal spinal root (afferent) stimulation and test if bilateral stimulation is more effective than unilateral stimulation. External urethral sphincter (EUS) electromyography (EMG) is also assessed in conjunction with cystometrogram. MATERIALS AND METHODS: Eighteen female Sprague-Dawley rats were tested following urethane anesthesia. Via urethral catheterization, the bladder was infused with normal saline to evoke rhythmic bladder reflex contractions (BRC). L6 spinal nerves were isolated and stimulated. RESULTS: L6 stimulation was effective in inhibiting BRC. L6 bilateral dorsal root (DR) stimulation of 50% intensity was required to cause inhibition as compared to unilateral stimulation. In EUS EMG recordings, there was a strong association between EUS EMG activities and bladder contraction. When the bladder contraction was inhibited effectively by L6 DR stimulation, a considerable reduction was also found in the EUS EMG activities. CONCLUSIONS: L6 DR stimulation abolished BRC in our rat model. Bilateral L6 DR stimulation produced a 50% reduction in stimulation intensity, providing a similar BRC block. Abolishing BRC also appeared to coincide with a reduction in EUS EMG, implicating that sacral neuromodulation might act centrally, at least rostrally at the T8-9 spinal level.


Asunto(s)
Estimulación Eléctrica/métodos , Raíces Nerviosas Espinales/fisiología , Uretra/fisiopatología , Vejiga Urinaria/inervación , Vejiga Urinaria/fisiopatología , Anestesia/métodos , Animales , Electromiografía/métodos , Femenino , Contracción Muscular , Ratas , Ratas Sprague-Dawley , Uretano/química , Uretano/uso terapéutico , Micción , Enfermedades Urológicas
13.
J Neurosci ; 33(28): 11329-45, 2013 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-23843507

RESUMEN

Axon regeneration after injury requires the extensive reconstruction, reorganization, and stabilization of the microtubule cytoskeleton in the growth cones. Here, we identify KIF3C as a key regulator of axonal growth and regeneration by controlling microtubule dynamics and organization in the growth cone. KIF3C is developmentally regulated. Rat embryonic sensory axons and growth cones contain undetectable levels of KIF3C protein that is locally translated immediately after injury. In adult neurons, KIF3C is axonally transported from the cell body and is enriched at the growth cone where it preferentially binds to tyrosinated microtubules. Functionally, the interaction of KIF3C with EB3 is necessary for its localization at the microtubule plus-ends in the growth cone. Depletion of KIF3C in adult neurons leads to an increase in stable, overgrown and looped microtubules because of a strong decrease in the microtubule frequency of catastrophes, suggesting that KIF3C functions as a microtubule-destabilizing factor. Adult axons lacking KIF3C, by RNA interference or KIF3C gene knock-out, display an impaired axonal outgrowth in vitro and a delayed regeneration after injury both in vitro and in vivo. Murine KIF3C knock-out embryonic axons grow normally but do not regenerate after injury because they are unable to locally translate KIF3C. These data show that KIF3C is an injury-specific kinesin that contributes to axon growth and regeneration by regulating and organizing the microtubule cytoskeleton in the growth cone.


Asunto(s)
Axones/fisiología , Cinesinas/fisiología , Microtúbulos/fisiología , Regeneración Nerviosa/fisiología , Animales , Células Cultivadas , Femenino , Conos de Crecimiento/metabolismo , Conos de Crecimiento/fisiología , Células HEK293 , Humanos , Masculino , Ratones , Ratones Noqueados , Ratas , Ratas Sprague-Dawley , Neuropatía Ciática/metabolismo , Neuropatía Ciática/patología
14.
IEEE Open J Eng Med Biol ; 5: 59-65, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38445242

RESUMEN

Emerging therapies in bioelectronic medicine highlight the need for deeper understanding of electrode material performance in the context of tissue stimulation. Electrochemical properties are characterized on the benchtop, facilitating standardization across experiments. On-nerve electrochemistry differs from benchtop characterization and the relationship between electrochemical performance and nerve activation thresholds are not commonly established. This relationship is important in understanding differences between electrical stimulation requirements and electrode performance. We report functional electrochemistry as a follow-up to benchtop testing, describing a novel experimental approach for evaluating on-nerve electrochemical performance in the context of nerve activation. An ex-vivo rat sciatic nerve preparation was developed to quantify activation thresholds of fiber subtypes and electrode material charge injection limits for platinum iridium, iridium oxide, titanium nitride and PEDOT. Finally, we address experimental complexities arising in these studies, and demonstrate statistical solutions that support rigorous material performance comparisons for decision making in neural interface development.

15.
Int J Low Extrem Wounds ; : 15347346241252200, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38748515

RESUMEN

Diabetic Foot in Primary and Tertiary (DEFINITE) Care is an inter-institutional, multidisciplinary team (MDT) program for patients with diabetic foot ulcers (DFU) within a healthcare cluster in Singapore. This is one of our subgroup analyses within DEFINITE Care, assessing clinical outcomes of lower extremity amputation prevention program (LEAPP), a multidisciplinary diabetic foot clinic, and non-LEAPP patients within the program. From June 2020 to June 2022, 2798 patients within the DEFINITE cohort completed a minimum of 12-month follow up. Of these patients, 20.6% were managed by LEAPP, whereas 79.4% were non-LEAPP patients. Patients in the LEAPP cohort were older with co-existing metabolic conditions and complications of diabetes. Using non-LEAPP cohort as the reference group and after adjusting for age, gender, ethnicity, comorbidities, and medications, there was a significantly lower risk of death (odds ratio [OR] 0.60, P = .001) and composite major lower extremity amputation (LEA) or death (OR 0.66, P = .002) among LEAPP patients at 1 year with longer mean days from enrollment to minor LEA, major LEA, and death. The adjusted 1-year healthcare utilization outcomes for LEAPP patients demonstrated an increase in inpatient admissions, primary care polyclinic visits, hospital specialist outpatient clinic (SOC) visits and elective day surgery procedures. Despite the increased in inpatients admissions, cumulative hospital length of stay in LEAPP patients were lower. This subgroup analysis has demonstrated that the MDT approach to caring for patients with DFU in tertiary centers not only improves mortality by 40%, but also delayed the incidence of minor LEA, major LEA, and death.

16.
Diabetes Res Clin Pract ; 202: 110737, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37285967

RESUMEN

AIM: To evaluate the association between trajectories of glycated haemoglobin (HbA1c) and potentially avoidable hospitalisations (PAH). METHODS: We performed a cohort study in a tertiary hospital in Singapore among adult type 2 diabetes patients with ≥ 3 HbA1c tests over two years. Then, we followed up for one year after the last HbA1c reading to determine the PAH outcome. Glycaemic control was analysed by (1) HbA1c trajectories through group-based trajectory modelling, and (2) mean HbA1c. PAH was defined using the Agency of Healthcare Research and Quality criteria, categorising as overall, diabetes, acute, and chronic-composites. RESULTS: A total of 14,923 patients (mean age: 62.9 ± 12.8 years; 55.2% men) were included. Four HbA1c trajectories were observed; low-stable (n = 9854, 66.0%), moderate-stable (n = 3125, 20.9%), high-decrease (n = 1017, 6.8%) and high-persistent (n = 927, 6.2%). Compared to the low-stable trajectory, one-year risk ratio (RR) and 95% confidence interval (CI), respectively for moderate-stable, high-decrease and high-persistent trajectories were as follows: (1) overall PAH: 1.15 (1.00-1.31), 1.53 (1.31-1.80), 1.96 (1.58-2.43); (2) diabetes PAH: 1.30 (1.04-1.64), 1.98 (1.55-2.53), 2.24 (1.59-3.15); (3) acute PAH: 1.14 (0.90-1.44), 1.29 (0.95-1.77), 1.75 (1.17-2.62); and (4) chronic PAH: 1.21 (1.02-1.43), 1.62 (1.34-1.97), 2.14 (1.67-2.75). Mean HbA1c was significantly associated with overall and chronic-composites of PAH whilst evidence of a non-linear relationship with diabetes-composite of PAH was noted. CONCLUSION: Patients with high-decrease trajectory had a risk lower than those with persistently-high HbA1c, highlighting that a greater risk of hospitalisation conferred by poor glycaemic control is potentially reversible. Determining HbA1c trajectories could help to identify the high-risk individuals for targeted and intensive management to improve care and reduce hospitalisations.


Asunto(s)
Diabetes Mellitus Tipo 2 , Hiperglucemia , Masculino , Humanos , Adulto , Persona de Mediana Edad , Anciano , Femenino , Diabetes Mellitus Tipo 2/epidemiología , Hemoglobina Glucada , Estudios de Cohortes , Centros de Atención Terciaria
17.
Front Neurosci ; 16: 1088628, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36620453

RESUMEN

Introduction: The autonomic nervous system is a key regulator of inflammation. Electrical stimulation of the vagus nerve has been shown to have some preclinical efficacy. However, only a few clinical studies have been reported to treat inflammatory diseases. The present study evaluates, for the first time, neuromodulation of the splenic arterial neurovascular bundle (SpA NVB) in patients undergoing minimally invasive esophagectomy (MIE), in which the SpA NVB is exposed as part of the procedure. Methods: This single-center, single-arm study enrolled 13 patients undergoing MIE. During the abdominal phase of the MIE, a novel cuff was placed around the SpA NVB, and stimulation was applied. The primary endpoint was the feasibility and safety of cuff application and removal. A secondary endpoint included the impact of stimulation on SpA blood flow changes during the stimulation, and an exploratory point was C-reactive protein (CRP) levels on postoperative day (POD) 2 and 3. Results: All patients successfully underwent placement, stimulation, and removal of the cuff on the SpA NVB with no adverse events related to the investigational procedure. Stimulation was associated with an overall reduction in splenic arterial blood flow but not with changes in blood pressure or heart rate. When compared to historic Propensity Score Matched (PSM) controls, CRP levels on POD2 (124 vs. 197 mg/ml, p = 0.032) and POD3 (151 vs. 221 mg/ml, p = 0.033) were lower in patients receiving stimulation. Conclusion: This first-in-human study demonstrated for the first time that applying a cuff around the SpA NVB and subsequent stimulation is safe, feasible, and may have an effect on the postoperative inflammatory response following MIE. These findings suggest that SpA NVB stimulation may offer a new method for immunomodulatory therapy in acute or chronic inflammatory conditions.

18.
EFORT Open Rev ; 6(9): 716-726, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34667642

RESUMEN

Osteoarthritis (OA) is a global health issue with myriad pathophysiological factors and is one of the most common causes of chronic disability in adults due to pain and altered joint function.The end stage of OA develops from a destructive inflammatory cycle, driven by the pro-inflammatory cytokines interleukin-1ß (IL-1ß) and tumour necrosis factor alpha (TNFα).Owing to the less predictable results of total knee arthroplasty (TKA) in younger patients presenting with knee OA, there has been a surge in research evaluating less invasive biological treatment options, one of which is autologous protein solution (APS).APS is an autologous blood derivative obtained by using a proprietary device, made of APS separator, which isolates white blood cells (WBCs) and platelets in a small volume of plasma, and APS concentrator, which further concentrates platelets, WBCs and plasma proteins, resulting in a concentrated solution with high levels of growth factors including the anti-inflammatory mediators against IL-1ß and TNFα.A single intraarticular injection of APS appears to be a promising solution for treatment of early-stage OA from current evidence, the majority of which comes from preclinical studies.More clinical studies are needed before APS can be widely accepted as a treatment modality for OA. Cite this article: EFORT Open Rev 2021;6:716-726. DOI: 10.1302/2058-5241.6.200040.

19.
J Patient Rep Outcomes ; 5(1): 54, 2021 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-34236563

RESUMEN

BACKGROUND: Graves' disease is the most common cause of hyperthyroidism. It results in accelerated tissue metabolism with multi-organ involvement ranging from cardiovascular to neuropsychological function. This results in a negative impact on the quality of life (QOL) of the individual patient. We aim to evaluate the psychometric properties of ThyPRO, a Thyroid-related Patient Reported Outcome questionnaire, and validate its use in our multi-ethnic Asian patients with Graves' hyperthyroidism. METHODS: Forty-seven consecutive Graves' hyperthyroidism patients answered the ThyPRO questionnaire at baseline and at 4 months after treatment initiation. Data were recorded for thyroid related symptoms and signs, thyroid function tests and thyroid volume. We analyzed the internal consistency using Cronbach's alpha, construct validity by evaluating relationship between clinical variables and ThyPRO scales, ceiling and floor effects, and responsiveness of ThyPRO to treatment based on Cohen's effect size. RESULTS: Correlations between individual scale scores and free thyroxine concentrations were moderate and statistically significant: 0.21-0.64 (p <  0.05). There was high internal consistency between the items in this instrument, Cronbach's alpha > 0.7 for all scales. ThyPRO was responsive to the changes in QOL after treatment (Effect Size: 0.20-0.77) in 9 of the 14 scales including the hyperthyroid symptoms and psychosocial scales (Tiredness, Cognitive complaints, Anxiety, Emotional susceptibility, Impact on Social, Daily and Sex life). CONCLUSION: This study provides evidence that ThyPRO has satisfactory measurement properties in hyperthyroid Graves' disease patients in Singapore population with the potential to complement clinical care.

20.
Knee ; 32: 103-111, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34455160

RESUMEN

BACKGROUND: Postoperative delirium (POD) is a cause of poorer patient outcomes following total joint arthroplasties (TJA). However, it often goes undiagnosed. Although various risk factors have been documented, study heterogeneity leads to poor understanding within a South East Asian population. This study aims to evaluate POD within this demographic and elucidate its risk factors. METHODS: This was a single-centre prospective observational study comprising 462 patients. Inclusion criteria was patients 65-90 years old undergoing elective TJA. Exclusion criteria was patients unable to personally provide consent for TJA. Preoperative, intraoperative, and postoperative data was recorded to analyse treatment pathway factors. Patients were assessed for POD twice daily for 3 days after TJA using the Confusion Assessment Method (CAM). RESULTS: Mean age of the study cohort was 72 ± 5 years; 70.1% were female; and mean MMSE score preoperatively was 27.3 ± 3.3. 419 patients underwent total knee arthroplasty (TKA) and 43 patients underwent total hip arthroplasty (THA). 164 patients received general anaesthesia, and 298 patients received regional anaesthesia. Overall, 0% (0/462) of patients tested positive for POD at any postoperative timepoint. While various CAM components were met, no patients were positive for the complete requisite criteria for POD diagnosis. CONCLUSION: We report zero incidence of POD in 462 patients who underwent elective TJA in our institution. We believe that our streamlined care process including pre-operative assessment, patient-specific anaesthesia regime as well as a strictly administered inpatient clinical care pathway with opioid-reducing strategy and early mobilization are protective factors against POD.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Delirio , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera/efectos adversos , Artroplastia de Reemplazo de Rodilla/efectos adversos , Delirio/diagnóstico , Delirio/epidemiología , Delirio/etiología , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Factores de Riesgo
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