Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
2.
J Am Assoc Lab Anim Sci ; 63(3): 209-220, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38749659

RESUMEN

Animal research facilities are noisy environments. The high air change rates required in animal housing spaces tend to create higher noise levels from the heating and cooling systems. Housing rooms are typically constructed of hard wall material that is easily cleaned but simultaneously highly reverberant, meaning that the sound cannot be controlled/attenuated so the sounds that are generated bounce around the room uncontrolled. (Soft, sound-absorbing surfaces generally cannot be used in animal facilities because they collect microbes; various wall surface features and sound control panel options are available, although rarely used.) In addition, many of our husbandry tasks such as cage changing, animal health checks, cleaning, and transporting animals produce high levels of noise. Finally, much of the equipment we have increasingly employed in animal housing spaces, such as ventilated caging motors, biosafety, or procedure cabinets, can generate high levels of background noise, including ultrasound. These and many additional factors conspire to create an acoustic environment that is neither naturalistic nor conducive to a stress-free environment. The acoustic variability both within and between institutions can serve as an enormous confounder for research studies and a threat to our ability to reproduce studies over time and between research laboratories. By gaining a better appreciation for the acoustic variables, paired with transparency in reporting the levels, we might be able to gain a better understanding of their impacts and thereby gain some level of control over such acoustic variables in the animal housing space. The result of this could improve both animal welfare and study reproducibility, helping to address our 3Rs goals of Replacement, Reduction, and Refinement in the animal biomedical research enterprise.


Asunto(s)
Crianza de Animales Domésticos , Animales de Laboratorio , Vivienda para Animales , Ruido , Ruido/efectos adversos , Animales , Crianza de Animales Domésticos/métodos , Bienestar del Animal , Experimentación Animal/normas
3.
Epidemiol Infect ; 152: e37, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38250791

RESUMEN

To investigate the symptoms of SARS-CoV-2 infection, their dynamics and their discriminatory power for the disease using longitudinally, prospectively collected information reported at the time of their occurrence. We have analysed data from a large phase 3 clinical UK COVID-19 vaccine trial. The alpha variant was the predominant strain. Participants were assessed for SARS-CoV-2 infection via nasal/throat PCR at recruitment, vaccination appointments, and when symptomatic. Statistical techniques were implemented to infer estimates representative of the UK population, accounting for multiple symptomatic episodes associated with one individual. An optimal diagnostic model for SARS-CoV-2 infection was derived. The 4-month prevalence of SARS-CoV-2 was 2.1%; increasing to 19.4% (16.0%-22.7%) in participants reporting loss of appetite and 31.9% (27.1%-36.8%) in those with anosmia/ageusia. The model identified anosmia and/or ageusia, fever, congestion, and cough to be significantly associated with SARS-CoV-2 infection. Symptoms' dynamics were vastly different in the two groups; after a slow start peaking later and lasting longer in PCR+ participants, whilst exhibiting a consistent decline in PCR- participants, with, on average, fewer than 3 days of symptoms reported. Anosmia/ageusia peaked late in confirmed SARS-CoV-2 infection (day 12), indicating a low discrimination power for early disease diagnosis.


Asunto(s)
Ageusia , COVID-19 , Humanos , Anosmia/epidemiología , Anosmia/etiología , COVID-19/diagnóstico , Prueba de COVID-19 , Vacunas contra la COVID-19 , Estudios Longitudinales , SARS-CoV-2 , Ensayos Clínicos Fase III como Asunto
4.
Clin Infect Dis ; 76(3): 398-407, 2023 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-36210481

RESUMEN

BACKGROUND: The recombinant protein-based vaccine, NVX-CoV2373, demonstrated 89.7% efficacy against coronavirus disease 2019 (COVID-19) in a phase 3, randomized, observer-blinded, placebo-controlled trial in the United Kingdom. The protocol was amended to include a blinded crossover. Data to the end of the placebo-controlled phase are reported. METHODS: Adults aged 18-84 years received 2 doses of NVX-CoV2373 or placebo (1:1) and were monitored for virologically confirmed mild, moderate, or severe COVID-19 (onset from 7 days after second vaccination). Participants who developed immunoglobulin G (IgG) against nucleocapsid protein but did not show symptomatic COVID-19 were considered asymptomatic. Secondary outcomes included anti-spike (S) IgG responses, wild-type virus neutralization, and T-cell responses. RESULTS: Of 15 185 participants, 13 989 remained in the per-protocol efficacy population (6989 NVX-CoV2373, 7000 placebo). At a maximum of 7.5 months (median, 4.5) postvaccination, there were 24 cases of COVID-19 among NVX-CoV2373 recipients and 134 cases among placebo recipients, a vaccine efficacy of 82.7% (95% confidence interval [CI], 73.3%-88.8%). Vaccine efficacy was 100% (95% CI, 17.9%-100.0%) against severe disease and 76.3% (95% CI, 57.4%-86.8%) against asymptomatic disease. High anti-S and neutralization responses to vaccination were evident, together with S-protein-specific induction of interferon-γ secretion in peripheral blood T cells. Incidence of serious adverse events and adverse events of special interest were similar between groups. CONCLUSIONS: A 2-dose regimen of NVX-CoV2373 conferred a high level of ongoing protection against asymptomatic, symptomatic, and severe COVID-19 through >6 months postvaccination. A gradual decrease of protection suggests that a booster may be indicated. CLINICAL TRIALS REGISTRATION: EudraCT, 2020-004123-16.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Adulto , Humanos , Vacunas contra la COVID-19/efectos adversos , COVID-19/prevención & control , SARS-CoV-2 , Vacunas Sintéticas/efectos adversos , Inmunoglobulina G , Inmunogenicidad Vacunal , Método Doble Ciego , Anticuerpos Antivirales
5.
Clin Endocrinol (Oxf) ; 97(5): 562-567, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35792134

RESUMEN

OBJECTIVES: Individuals with chronic hypoparathyroidism may experience suboptimal medical care with high frequency of unplanned hospitalisation and iatrogenic harm. In 2015 the European Society for Endocrinology published consensus guidelines on the management of chronic hypoparathyroidism. We set out to audit compliance with these guidelines. METHODS: Using these recommendations as audit standards we worked with the Society for Endocrinology and Parathyroid UK to conduct a national audit of management of chronic hypoparathyroidism in the United Kingdom. Endocrine leads in 117 endocrine departments were invited to participate in the survey by completing a data collection tool on up to 5 sequential cases of chronic hypoparathyroidism seen in their outpatient clinics in the preceding 12 months. Data were collected on 4 treatment standards and 9 monitoring standards. Data on hospitalisations and Quality of Life monitoring were also collected. RESULTS: Responses were received from 22 departments giving a response rate of 19%, concerning 80 individual cases. The mean age of subjects was 48.4 years. The main findings were that the commonest cause of hypoparathyroidism was post surgical (66.3%). Treatments taken by the group included activated vitamin D analogues (96.3%), oral calcium salts (66.3%), vitamin D supplements (17.5%), thiazide diuretics (5%) and rhPTH1-34 (1.3%). Compliance with the audit standards varied between 98.8% and 60% for the treatment standards and between 91.3% and 20% for the monitoring standards. Some of the areas of weakness revealed include low rates of 24 h urinary calcium excretion monitoring, serum magnesium monitoring and low rates of renal imaging where indicated. In addition and importantly, 16.3% of subjects had experienced at least one hospital admission in the preceding 12 months. CONCLUSION: We conclude that further improvements in the UK national standard of management of chronic hypoparathyroidism should be made and that this will benefit both quality of life, morbidity and potentially mortality in this group of patients.


Asunto(s)
Hipocalcemia , Hipoparatiroidismo , Calcio/uso terapéutico , Humanos , Hipocalcemia/etiología , Hipoparatiroidismo/complicaciones , Hipoparatiroidismo/tratamiento farmacológico , Magnesio , Persona de Mediana Edad , Hormona Paratiroidea , Calidad de Vida , Sales (Química) , Inhibidores de los Simportadores del Cloruro de Sodio , Vitamina D/uso terapéutico
6.
BMC Med ; 19(1): 183, 2021 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-34407811

RESUMEN

BACKGROUND: The purpose of this trial was to test if the Norfolk Diabetes Prevention Study (NDPS) lifestyle intervention, recently shown to reduce the incidence of type 2 diabetes in high-risk groups, also improved glycaemic control in people with newly diagnosed screen-detected type 2 diabetes. METHODS: We screened 12,778 participants at high risk of type 2 diabetes using a fasting plasma glucose and glycosylated haemoglobin (HbA1c). People with screen-detected type 2 diabetes were randomised in a parallel, three-arm, controlled trial with up to 46 months of follow-up, with a control arm (CON), a group-based lifestyle intervention of 6 core and up to 15 maintenance sessions (INT), or the same intervention with additional support from volunteers with type 2 diabetes trained to co-deliver the lifestyle intervention (INT-DPM). The pre-specified primary end point was mean HbA1c compared between groups at 12 months. RESULTS: We randomised 432 participants (CON 149; INT 142; INT-DPM 141) with a mean (SD) age of 63.5 (10.0) years, body mass index (BMI) of 32.4 (6.4) kg/m2, and HbA1c of 52.5 (10.2) mmol/mol. The primary outcome of mean HbA1c at 12 months (CON 48.5 (9.1) mmol/mol, INT 46.5 (8.1) mmol/mol, and INT-DPM 45.6 (6.0) mmol/mol) was significantly lower in the INT-DPM arm compared to CON (adjusted difference -2.57 mmol/mol; 95% CI -4.5, -0.6; p = 0.007) but not significantly different between the INT-DPM and INT arms (-0.55 mmol/mol; 95% CI -2.46, 1.35; p = 0.57), or INT vs CON arms (-2.14 mmol/mol; 95% CI -4.33, 0.05; p = 0.07). Subgroup analyses showed the intervention had greater effect in participants < 65 years old (difference in mean HbA1c compared to CON -4.76 mmol/mol; 95% CI -7.75, -1.78 mmol/mol) than in older participants (-0.46 mmol/mol; 95% CI -2.67, 1.75; interaction p = 0.02). This effect was most significant in the INT-DPM arm (-6.01 mmol/mol; 95% CI -9.56, -2.46 age < 65 years old and -0.22 mmol/mol; 95% CI -2.7, 2.25; aged > 65 years old; p = 0.007). The use of oral hypoglycaemic medication was associated with a significantly lower mean HbA1c but only within the INT-DPM arm compared to CON (-7.0 mmol/mol; 95% CI -11.5, -2.5; p = 0.003). CONCLUSION: The NDPS lifestyle intervention significantly improved glycaemic control after 12 months in people with screen-detected type 2 diabetes when supported by trained peer mentors with type 2 diabetes, particularly those receiving oral hypoglycaemics and those under 65 years old. The effect size was modest, however, and not sustained at 24 months. TRIAL REGISTRATION: ISRCTN34805606 . Retrospectively registered 14.4.16.


Asunto(s)
Diabetes Mellitus Tipo 2 , Anciano , Glucemia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/prevención & control , Proteínas del Ojo , Hemoglobina Glucada/análisis , Control Glucémico , Humanos , Hipoglucemiantes , Estilo de Vida , Persona de Mediana Edad , Proteínas del Tejido Nervioso , Resultado del Tratamiento
7.
Cureus ; 13(5): e15137, 2021 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-34164240

RESUMEN

Hypocalcaemia is a frequent, and potentially dangerous complication of total thyroidectomy occurring secondary to devascularisation of the parathyroid glands. This quality improvement (QI) project was undertaken in a large Ear, Nose and Throat (ENT) department in the East of England over a one year period. The project aimed to improve postoperative guideline compliance by optimising the recognition and management of patients at risk of hypocalcaemia. This process focussed on improving parathyroid hormone (PTH) and calcium blood testing, prophylactic calcium prescribing and the subsequent monitoring and management of hypocalcaemia. A baseline audit was conducted to determine the initial guideline compliance. The QI process subsequently involved the introduction of a new intraoperative PTH pathway and the amendment of trust guidelines. In addition, there was a focus on improving clinician awareness of guidelines, junior doctor education, communication between operating surgeons and junior doctors and the optimisation of patient handover. The project saw a significant improvement in the monitoring of hypocalcaemia (from 22.2% to 83.3% for patients with an intermediate risk of hypocalcaemia) and in the prescribing of prophylactic calcium supplements from 7.5% to 43.5%. The measurement of PTH at four hours improved from 42.5% to 52.2%. By optimising postoperative care, this QI project improved patient safety as well as impacting on the duration, and overall cost, of inpatient stay.

8.
N Engl J Med ; 385(13): 1172-1183, 2021 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-34192426

RESUMEN

BACKGROUND: Early clinical data from studies of the NVX-CoV2373 vaccine (Novavax), a recombinant nanoparticle vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that contains the full-length spike glycoprotein of the prototype strain plus Matrix-M adjuvant, showed that the vaccine was safe and associated with a robust immune response in healthy adult participants. Additional data were needed regarding the efficacy, immunogenicity, and safety of this vaccine in a larger population. METHODS: In this phase 3, randomized, observer-blinded, placebo-controlled trial conducted at 33 sites in the United Kingdom, we assigned adults between the ages of 18 and 84 years in a 1:1 ratio to receive two intramuscular 5-µg doses of NVX-CoV2373 or placebo administered 21 days apart. The primary efficacy end point was virologically confirmed mild, moderate, or severe SARS-CoV-2 infection with an onset at least 7 days after the second injection in participants who were serologically negative at baseline. RESULTS: A total of 15,187 participants underwent randomization, and 14,039 were included in the per-protocol efficacy population. Of the participants, 27.9% were 65 years of age or older, and 44.6% had coexisting illnesses. Infections were reported in 10 participants in the vaccine group and in 96 in the placebo group, with a symptom onset of at least 7 days after the second injection, for a vaccine efficacy of 89.7% (95% confidence interval [CI], 80.2 to 94.6). No hospitalizations or deaths were reported among the 10 cases in the vaccine group. Five cases of severe infection were reported, all of which were in the placebo group. A post hoc analysis showed an efficacy of 86.3% (95% CI, 71.3 to 93.5) against the B.1.1.7 (or alpha) variant and 96.4% (95% CI, 73.8 to 99.5) against non-B.1.1.7 variants. Reactogenicity was generally mild and transient. The incidence of serious adverse events was low and similar in the two groups. CONCLUSIONS: A two-dose regimen of the NVX-CoV2373 vaccine administered to adult participants conferred 89.7% protection against SARS-CoV-2 infection and showed high efficacy against the B.1.1.7 variant. (Funded by Novavax; EudraCT number, 2020-004123-16.).


Asunto(s)
Vacunas contra la COVID-19 , COVID-19/prevención & control , Inmunogenicidad Vacunal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , COVID-19/epidemiología , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/efectos adversos , Vacunas contra la COVID-19/inmunología , Humanos , Inyecciones Intramusculares/efectos adversos , Persona de Mediana Edad , SARS-CoV-2 , Método Simple Ciego , Vacunas Sintéticas/inmunología , Adulto Joven
9.
JAMA Intern Med ; 181(2): 168-178, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33136119

RESUMEN

Importance: Nearly half of the older adult population has diabetes or a high-risk intermediate glycemic category, but we still lack trial evidence for effective type 2 diabetes prevention interventions in most of the current high-risk glycemic categories. Objective: To determine whether a group-based lifestyle intervention (with or without trained volunteers with type 2 diabetes) reduced the risk of progression to type 2 diabetes in populations with a high-risk glycemic category. Design, Setting, and Participants: The Norfolk Diabetes Prevention Study was a parallel, 3-arm, group-based, randomized clinical trial conducted with up to 46 months of follow-up from August 2011 to January 2019 at 135 primary care practices and 8 intervention sites in the East of England. We identified 141 973 people at increased risk of type 2 diabetes, screened 12 778 (9.0%), and randomized those with a high-risk glycemic category, which was either an elevated fasting plasma glucose level alone (≥110 and <126 mg/dL [to convert to millimoles per liter, multiply by 0.0555]) or an elevated glycated hemoglobin level (≥6.0% to <6.5%; nondiabetic hyperglycemia) with an elevated fasting plasma glucose level (≥100 to <110 mg/dL). Interventions: A control arm receiving usual care (CON), a theory-based lifestyle intervention arm of 6 core and up to 15 maintenance sessions (INT), or the same intervention with support from diabetes prevention mentors, trained volunteers with type 2 diabetes (INT-DPM). Main Outcomes and Measures: Type 2 diabetes incidence between arms. Results: In this study, 1028 participants were randomized (INT, 424 [41.2%] [166 women (39.2%)]; INT-DPM, 426 [41.4%] [147 women (34.5%)]; CON, 178 [17.3%] [70 women (%39.3)]) between January 1, 2011, and February 24, 2017. The mean (SD) age was 65.3 (10.0) years, mean (SD) body mass index 31.2 (5) (calculated as weight in kilograms divided by height in meters squared), and mean (SD) follow-up 24.7 (13.4) months. A total of 156 participants progressed to type 2 diabetes, which comprised 39 of 171 receiving CON (22.8%), 55 of 403 receiving INT (13.7%), and 62 of 414 receiving INT-DPM (15.0%). There was no significant difference between the intervention arms in the primary outcome (odds ratio [OR], 1.14; 95% CI, 0.77-1.7; P = .51), but each intervention arm had significantly lower odds of type 2 diabetes (INT: OR, 0.54; 95% CI, 0.34-0.85; P = .01; INT-DPM: OR, 0.61; 95% CI, 0.39-0.96; P = .033; combined: OR, 0.57; 95% CI, 0.38-0.87; P = .01). The effect size was similar in all glycemic, age, and social deprivation groups, and intervention costs per participant were low at $153 (£122). Conclusions and Relevance: The Norfolk Diabetes Prevention lifestyle intervention reduced the risk of type 2 diabetes in current high-risk glycemic categories. Enhancing the intervention with DPM did not further reduce diabetes risk. These translatable results are relevant for current diabetes prevention efforts. Trial Registration: ISRCTN Registry Identifier: ISRCTN34805606.


Asunto(s)
Diabetes Mellitus Tipo 2/prevención & control , Estilo de Vida , Estado Prediabético , Voluntarios , Anciano , Glucemia , Diabetes Mellitus Tipo 2/epidemiología , Dieta , Inglaterra/epidemiología , Ejercicio Físico , Ayuno , Femenino , Conductas Relacionadas con la Salud , Humanos , Hiperglucemia/epidemiología , Masculino
10.
J Am Assoc Lab Anim Sci ; 59(6): 665-672, 2020 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-32928338

RESUMEN

Noise and vibration are present in every room of laboratory animal vivaria, with great variability from room-to-room and facility-to-facility. Such stimuli are rarely measured. As a result, the many stakeholders involved in biomedical research, (for example, funding agencies, construction personnel, equipment manufacturers, animal facility administrators, veterinarians, technicians, and scientists) have little awareness of the effects such stimuli may have on their research animals. Noise and vibration present a potential source of unrecognized animal distress, and a significant, uncontrolled and confounding variable in scientific studies. Unmeasured and unrecognized noise and vibration can therefore undermine the fundamental goals of the 3R's to refine animal models and reduce the number of animals used in biomedical and behavioral research. This overview serves to highlight the scope of this problem and proposes a series of recommended practices to limit its negative effects on research animals and the scientific data derived from them. These practices consist of developing a written plan for managing noise and vibration concerns, assessment of noise and vibration both annually and whenever unexpected changes in the facility or animals are observed, and for maintaining levels of chronic noise below thresholds that might cause animal welfare concerns or disruptions in ongoing studies.


Asunto(s)
Bienestar del Animal , Animales de Laboratorio , Vivienda para Animales/normas , Animales , Ruido , Estrés Fisiológico , Vibración
11.
BMJ Case Rep ; 12(3)2019 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-30872334

RESUMEN

A 71-year-old woman who had been taking ibandronate for 10 years presented to an Endocrinology Department with persistent mid-thigh pain. Pelvic X-ray showed bilateral femoral cortical expansion, indicating impending atypical femoral fractures (AFFs). AFFs have been linked to long-term bisphosphonate therapy and have morbidity and mortality similar to that of hip fractures. Such fractures can be averted by regular reviews of bisphosphonate therapy and vigilance for prodromal symptoms. This patient's bisphosphonate therapy was stopped, and fractures were avoided by treatment with vitamin D and parathyroid hormone.


Asunto(s)
Difosfonatos/efectos adversos , Fracturas del Fémur/inducido químicamente , Fracturas del Fémur/prevención & control , Anciano , Conservadores de la Densidad Ósea/efectos adversos , Enfermedades Óseas/inducido químicamente , Enfermedades Óseas/diagnóstico por imagen , Enfermedades Óseas/patología , Hormonas y Agentes Reguladores de Calcio/uso terapéutico , Diagnóstico Diferencial , Femenino , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/patología , Humanos , Hormona Paratiroidea/administración & dosificación , Hormona Paratiroidea/uso terapéutico , Enfermedades Raras , Resultado del Tratamiento , Vitamina D/administración & dosificación , Vitamina D/uso terapéutico
12.
Endocr Connect ; 8(6): X1, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32022081

RESUMEN

In this addendum to the above paper, the Society for Endocrinology Clinical Committee and the original authors provide additional advice on the dose equivalence of calcium gluconate and calcium chloride. The 'Severe hypocalcaemia' section, which appeared in the September 2016 issue of Endocrine Connections (volume 5, page G8, https://doi.org/10.1530/EC-16-0056 reads as follows: Severe hypocalcaemia Severe hypocalcaemia: serum calcium <1.9 mmol/L and/or symptomatic at any level below reference range. This is a medical emergency Administer i.v. calcium gluconate Initially, give 10­20 mL 10% calcium gluconate in 50­100 mL of 5% dextrose i.v. over 10 min with ECG monitoring. This can be repeated until the patient is asymptomatic. It should be followed up with a calcium gluconate infusion as follows: Dilute 100 mL of 10% calcium gluconate (10 vials) in 1 L of Normal saline or 5% dextrose and infuse at 50­100 mL/h. (Calcium chloride can be used as an alternative to calcium gluconate, but it is more irritant to veins and should only be given via a central line) Titrate the rate of infusion to achieve normocalcaemia and continue until treatment of the underlying cause has taken effect The Society for Endocrinology Clinical Committee and the original authors now provide this additional advice on the dose equivalence of calcium gluconate and calcium chloride, as follows: Each 10 mL vial of 10% calcium gluconate contains 2.2 mmol of calcium. Calcium chloride for i.v. administration is available in a number of preparations including, commonly, 10 mL of 7.35% calcium chloride (which contains 5 mmol of calcium) and 5 mL of 14.7% calcium chloride (which also contains 5 mmol of calcium). Great care should be taken since other preparations are also available. If using calcium chloride in place of calcium gluconate, 4.4 mL of 7.35% calcium chloride or 2.2 mL of 14.7% calcium chloride for i.v. administration should therefore be used as equivalent to 10 mL of 10% calcium gluconate. If other calcium chloride preparations are used, the required volume should be calculated, aiming to achieve 2.2­4.4 mmol i.v. loading bolus followed by a 1.1­2.2 mmol/h maintenance infusion.

13.
J Cell Sci ; 131(22)2018 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-30333139

RESUMEN

White adipocytes are key regulators of metabolic homeostasis, which release stored energy as free fatty acids via lipolysis. Adipocytes possess both basal and stimulated lipolytic capacity, but limited information exists regarding the molecular mechanisms that regulate basal lipolysis. Here, we describe a mechanism whereby autocrine purinergic signalling and constitutive P2Y2 receptor activation suppresses basal lipolysis in primary human in vitro-differentiated adipocytes. We found that human adipocytes possess cytoplasmic Ca2+ tone due to ATP secretion and constitutive P2Y2 receptor activation. Pharmacological antagonism or knockdown of P2Y2 receptors increases intracellular cAMP levels and enhances basal lipolysis. P2Y2 receptor antagonism works synergistically with phosphodiesterase inhibitors in elevating basal lipolysis, but is dependent upon adenylate cyclase activity. Mechanistically, we suggest that the increased Ca2+ tone exerts an anti-lipolytic effect by suppression of Ca2+-sensitive adenylate cyclase isoforms. We also observed that acute enhancement of basal lipolysis following P2Y2 receptor antagonism alters the profile of secreted adipokines leading to longer-term adaptive decreases in basal lipolysis. Our findings demonstrate that basal lipolysis and adipokine secretion are controlled by autocrine purinergic signalling in human adipocytes.


Asunto(s)
Adipocitos/metabolismo , Receptores Purinérgicos P2Y2/metabolismo , Adenosina Trifosfato/metabolismo , Adenilil Ciclasas/metabolismo , Adipocitos/citología , Adipocitos/efectos de los fármacos , Adulto , Anciano , Calcio/metabolismo , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/fisiología , Femenino , Humanos , Lipólisis/efectos de los fármacos , Persona de Mediana Edad , Cultivo Primario de Células , Antagonistas del Receptor Purinérgico P2Y/farmacología , Transducción de Señal
14.
Purinergic Signal ; 14(4): 371-384, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30088129

RESUMEN

Adipose tissue contains self-renewing multipotent cells termed mesenchymal stromal cells. In situ, these cells serve to expand adipose tissue by adipogenesis, but their multipotency has gained interest for use in tissue regeneration. Little is known regarding the repertoire of receptors expressed by adipose-derived mesenchymal stromal cells (AD-MSCs). The purpose of this study was to undertake a comprehensive analysis of purinergic receptor expression. Mesenchymal stromal cells were isolated from human subcutaneous adipose tissue and confirmed by flow cytometry. The expression profile of purinergic receptors was determined by quantitative real-time PCR and immunocytochemistry. The molecular basis for adenine and uracil nucleotide-evoked intracellular calcium responses was determined using Fura-2 measurements. All the known subtypes of P2X and P2Y receptors, excluding P2X2, P2X3 and P2Y12 receptors, were detected at the mRNA and protein level. ATP, ADP and UTP elicited concentration-dependent calcium responses in mesenchymal cells (N = 7-9 donors), with a potency ranking ADP (EC50 1.3 ± 1.0 µM) > ATP (EC50 2.2 ± 1.1 µM) = UTP (3.2 ± 2.8 µM). Cells were unresponsive to UDP (< 30 µM) and UDP-glucose (< 30 µM). ATP responses were attenuated by selective P2Y2 receptor antagonism (AR-C118925XX; IC50 1.1 ± 0.8 µM, 73.0 ± 8.5% max inhibition; N = 7 donors), and UTP responses were abolished. ADP responses were attenuated by the selective P2Y6 receptor antagonist, MRS2587 (IC50 437 ± 133nM, 81.0 ± 8.4% max inhibition; N = 6 donors). These data demonstrate that adenine and uracil nucleotides elicit intracellular calcium responses in human AD-MSCs with a predominant role for P2Y2 and P2Y6 receptor activation. This study furthers understanding about how human adipose-derived mesenchymal stromal cells can respond to external signalling cues.


Asunto(s)
Células Madre Mesenquimatosas/metabolismo , Receptores Purinérgicos P2Y2/metabolismo , Receptores Purinérgicos P2/metabolismo , Adenosina Difosfato/metabolismo , Calcio/metabolismo , Humanos , Uridina Difosfato/metabolismo , Uridina Trifosfato/metabolismo
15.
Sci Rep ; 8(1): 6240, 2018 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-29674706

RESUMEN

The world diabetes population quadrupled between 1980 and 2014 to 422 million and the enormous impact of Type 2 diabetes is recognised by the recent creation of national Type 2 diabetes prevention programmes. There is uncertainty about how to correctly risk stratify people for entry into prevention programmes, how combinations of multiple 'at high risk' glycemic categories predict outcome, and how the large recently defined 'at risk' population based on an elevated glycosylated haemoglobin (HbA1c) should be managed. We identified all 141,973 people at highest risk of diabetes in our population, and screened 10,000 of these with paired fasting plasma glucose and HbA1c for randomisation into a very large Type 2 diabetes prevention trial. Baseline discordance rate between highest risk categories was 45.6%, and 21.3-37.0% of highest risk glycaemic categories regressed to normality between paired baseline measurements (median 40 days apart). Accurate risk stratification using both fasting plasma glucose and HbA1c data, the use of paired baseline data, and awareness of diagnostic imprecision at diagnostic thresholds would avoid substantial overestimation of the true risk of Type 2 diabetes and the potential benefits (or otherwise) of intervention, in high risk subjects entering prevention trials and programmes.


Asunto(s)
Glucemia/análisis , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiología , Hemoglobina Glucada/análisis , Adulto , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/prevención & control , Ayuno/sangre , Femenino , Humanos , Hiperglucemia/diagnóstico , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Medición de Riesgo , Reino Unido
16.
J Immunol ; 200(3): 1159-1168, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29255078

RESUMEN

Leukocytes sense extracellular ATP, a danger-associated molecular pattern, released during cellular stress and death, via activation of cell surface P2X and P2Y receptors. Here, we investigate P2 receptor expression in primary human monocyte-derived macrophages and receptors that mediate ATP-evoked intracellular [Ca2+]i signals and cytokine production in response to ATP concentrations that exclude P2X7 receptor activation. Expression of P2X1, P2X4, P2X5, P2X7, P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, and P2Y13 was confirmed by quantitative RT-PCR and immunocytochemistry. ATP elicited intracellular Ca2+ responses in a concentration-dependent fashion (EC50 = 11.4 ± 2.9 µM, n = 3). P2Y11 and P2Y13 activations mediated the amplitude of [Ca2+]i response, whereas P2X4 activation, but not P2X1 or P2X7, determined the duration of Ca2+ response during a sustained phase. ATP mediated gene induction of CXCL5, a proinflammatory chemokine. P2X4 antagonism (PSB-12062 or BX430) inhibited ATP-mediated induction of CXCL5 gene expression and secretion of CXCL5 by primary macrophage. Inhibition of CXCL5 secretion by P2X4 antagonists was lost in the absence of extracellular Ca2+ Reciprocally, positive allosteric modulation of P2X4 (ivermectin) augmented ATP-mediated CXCL5 secretion. P2X7, P2Y11, or P2Y13 receptor did not contribute to CXCL5 secretion. Together, the data reveals a role for P2X4 in determining the duration of ATP-evoked Ca2+ responses and CXCL5 secretion in human primary macrophage.


Asunto(s)
Adenosina Trifosfato/metabolismo , Calcio/metabolismo , Quimiocina CXCL5/metabolismo , Macrófagos/metabolismo , Receptores Purinérgicos P2X4/metabolismo , Señalización del Calcio , Células Cultivadas , Activación Enzimática/fisiología , Regulación de la Expresión Génica/inmunología , Humanos , Macrófagos/inmunología , Antagonistas del Receptor Purinérgico P2X/farmacología , Receptores Purinérgicos P2Y/metabolismo
17.
Bone Rep ; 7: 63-69, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28932769

RESUMEN

Phosphaturic mesenchymal tumours are a heterogeneous set of bone and soft tissue neoplasms that can cause a number of paraneoplastic syndromes such as tumour induced osteomalacia. The term phosphaturic comes from the common finding that these tumours secrete high levels of fibroblast growth factor 23 which causes renal phosphate wasting leading to hypophosphatemia. Phosphaturic mesenchymal tumours are rare and diagnosis is difficult. A very active 68 year old male presented with bone pain and muscle weakness. He was hypophosphataemic and total alkaline phosphatase was markedly elevated. The patient was placed on vitamin D supplementation but his condition progressed. In the fifth year of presentation the patient required the use of a wheelchair and described "explosive" bone pain on physical contact. Serum 1,25 dihydroxyvitamin D was low and serum fibroblast growth factor 23 was significantly elevated, raising suspicion of a phosphaturic mesenchymal tumour. A lesion was detected in his left femoral head and the patient underwent a total hip replacement. The patient displayed a rapid improvement to his condition and during a three year follow up period he returned to an active lifestyle. As molecular testing may help provide a robust diagnosis and is particularly useful in rare diseases we took a next generation sequencing approach to identify a differential expression of small RNAs in the resected tumour. Small RNAs are non-coding RNA molecules that play a key role in regulation of gene expression and can be used as specific biomarkers. We found an upregulation of miR-197. We also found a downregulation of miR-20b, miR-144 and miR-335 which is a small RNA profile typical of osteosarcoma. MiR-21, the most frequently upregulated microRNA in cancer, was downregulated. We conclude that the specific small RNA profile is typical of osteosarcoma except for the downregulation of oncogenic miR-21. Transcriptional plasticity of miR-197, which is computationally predicted to target fibroblast growth factor 23 messenger RNA, may be upregulated in a cellular effort to correct the ectopic expression of the protein.

18.
Clin Med (Lond) ; 17(3): 270-273, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28572230

RESUMEN

Hypercalcaemia is a common disorder normally caused by primary hyperparathyroidism (PHPT) or malignancy. A proportion of cases present as an emergency, which carries a significant mortality. Emergency management of hypercalcaemia is based on intravenous rehydration with normal saline but when this is inadequate, bisphosphonate therapy is used; more recently the novel anti-resorbtive agent denosumab has been shown to have a useful role in treatment. It is estimated that up to 10% of all cases of PHPT presenting under the age of 45 years have an underlying genetic predisposition; nine potentially causative genes are now recognised and may be screened in routine clinical practice. Although parathyroidectomy is the only curative treatment for PHPT, this is indicated in a minority of cases. Many cases can be adequately managed conservatively and guidance from the 4th international workshop on the management of asymptomatic PHPT has recently been updated in a consensus statement.


Asunto(s)
Hipercalcemia , Difosfonatos/uso terapéutico , Humanos , Hipercalcemia/diagnóstico , Hipercalcemia/fisiopatología , Hipercalcemia/terapia , Hiperparatiroidismo Primario , Paratiroidectomía
19.
Blood ; 129(10): 1320-1332, 2017 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-28049638

RESUMEN

Despite currently available therapies, most patients diagnosed with acute myeloid leukemia (AML) die of their disease. Tumor-host interactions are critical for the survival and proliferation of cancer cells; accordingly, we hypothesize that specific targeting of the tumor microenvironment may constitute an alternative or additional strategy to conventional tumor-directed chemotherapy. Because adipocytes have been shown to promote breast and prostate cancer proliferation, and because the bone marrow adipose tissue accounts for up to 70% of bone marrow volume in adult humans, we examined the adipocyte-leukemia cell interactions to determine if they are essential for the growth and survival of AML. Using in vivo and in vitro models of AML, we show that bone marrow adipocytes from the tumor microenvironment support the survival and proliferation of malignant cells from patients with AML. We show that AML blasts alter metabolic processes in adipocytes to induce phosphorylation of hormone-sensitive lipase and consequently activate lipolysis, which then enables the transfer of fatty acids from adipocytes to AML blasts. In addition, we report that fatty acid binding protein-4 (FABP4) messenger RNA is upregulated in adipocytes and AML when in coculture. FABP4 inhibition using FABP4 short hairpin RNA knockdown or a small molecule inhibitor prevents AML proliferation on adipocytes. Moreover, knockdown of FABP4 increases survival in Hoxa9/Meis1-driven AML model. Finally, knockdown of carnitine palmitoyltransferase IA in an AML patient-derived xenograft model improves survival. Here, we report the first description of AML programming bone marrow adipocytes to generate a protumoral microenvironment.


Asunto(s)
Adipocitos/patología , Células de la Médula Ósea/patología , Leucemia Mieloide Aguda/patología , Microambiente Tumoral/fisiología , Adipocitos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Western Blotting , Células de la Médula Ósea/metabolismo , Técnicas de Cocultivo , Proteínas de Unión a Ácidos Grasos/metabolismo , Femenino , Citometría de Flujo , Xenoinjertos , Humanos , Inmunohistoquímica , Leucemia Mieloide Aguda/metabolismo , Masculino , Ratones , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...