Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 109
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Aust N Z J Public Health ; 43(5): 496-503, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31535432

RESUMO

OBJECTIVE: To provide insights into complexities of seeking access to state and federal cross-jurisdictional data for linkage with the Australian Childhood Immunisation Register (ACIR). We provide recommendations for improving access and receipt of linked datasets involving Australian Government-administered data. METHODS: We describe requirements for linking eleven federal and state data sources to establish a national linked dataset for safety evaluation of vaccines. The required data linkage methodology for integrating cross-jurisdictional data sources is also described. RESULTS: Extensive negotiation was required with 18 different agencies for 21 separate authorisations and 12 ethics approvals. Three variations of the 'best practice' linkage model were implemented. Australian Government approval requests spanned nearly four years from initial request for data, with a further year before ACIR data transfer to the linkage agency. CONCLUSIONS: Integration of immunisation registers with other data collections is achievable in Australia but infeasible for routine and rapid identification of vaccine safety concerns. Lengthy authorisation requirements, convoluted disparate application processes and inconsistencies in data supplied all contribute to delayed data availability. Implications for public health: Delayed data access for safety surveillance prevents timely epidemiological reviews. Poor responsiveness to safety concerns may erode public confidence, compromising effectiveness of vaccination programs through reduced participation.


Assuntos
Controle de Doenças Transmissíveis/estatística & dados numéricos , Coleta de Dados/legislação & jurisprudência , Imunização , Registro Médico Coordenado , Sistema de Registros , Vacinação/estatística & dados numéricos , Austrália , Criança , Humanos , Programas de Imunização , Formulação de Políticas , Vacinas
2.
J Physiol ; 597(13): 3425-3439, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31077379

RESUMO

KEY POINTS: While the presence of GABA receptors on primary afferents has been well described, most functional analyses have focused on the regulation of transmitter release from central terminals and/or signalling in the sensory neuron cell body. Evidence that GABA receptors are transported to peripheral terminals and that there are several sources of GABA in the colon raise the possibility that GABA signalling in the periphery may influence colonic afferent excitability. GABAA and GABAB are present and functional in the colon, where exogenous agonists decrease the excitability of colonic afferents and suppress visceral nociception. Endogenous GABA release within the colon is sufficient to establish the resting excitability of colonic afferents as well as the behavioural response to noxious stimulation of the colon, primarily via GABAA receptors. Peripheral GABA receptors may serve as a viable target for the treatment of visceral pain. ABSTRACT: It is well established that GABA receptors at the central terminals of primary afferent fibres regulate afferent input to the superficial dorsal horn. However, the extent to which peripheral GABA signalling may also regulate afferent input remains to be determined. The colon was used to explore this issue because of the numerous endogenous sources of GABA that have been described in this tissue. The influence of GABA signalling on colonic afferent excitability was assessed in an ex vivo mouse colorectum pelvic nerve preparation where test compounds were applied to the receptive field. The visceromotor response (VMR) evoked by noxious colorectal distension was used to assess the impact of GABA signalling on visceral nociception, where test compounds were applied directly to the colon. Application of either GABAA or GABAB receptor agonists attenuated the colonic afferent response to colon stretch. Conversely, GABAA and GABAB receptor antagonists increased the stretch response. However, while the noxious distension-induced VMR was attenuated in the presence of GABAA and GABAB receptor agonists, the VMR was only consistently increased by GABAA receptor antagonists. These results suggest that GABA receptors are present and functional in the peripheral terminals of colonic afferents and activation of these receptors via endogenous GABA release contributes to the establishment of colonic afferent excitability and visceral nociception. These results suggest that increasing peripheral GABA receptor signalling could be used to treat visceral pain.

4.
J Pain ; 20(7): 810-818, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30659887

RESUMO

Sensory neuron nicotinic acetylcholine receptors (nAChRs) contribute to pain associated with tissue injury. However, there are marked differences between rats and mice with respect to both the properties and distribution of nAChR currents in sensory neurons. Because both species are used to understand pain signaling in humans, we sought to determine whether the currents present in either species was reflective of those present in human sensory neurons. Neurons from the L4/L5 dorsal root ganglia were obtained from adult male and female organ donors. Nicotine evoked currents were detected in 40 of 47 neurons (85%). In contrast with the naïve mouse, in which almost all nAChR currents are transient, or the rat, in which both mouse-like transient and more slowly activating and inactivating currents are detected, all the currents in human DRG neurons were slow, but slower than those in the rat. Currents were blocked by the nAChR antagonists mecamylamine (30 µmol/L), but not by the TRPA1 selective antagonist HC-030031 (10 µmol/L). Single cell polymerase chain reaction analysis of nicotinic receptor subunit expression in human DRG neurons are consistent with functional data indicating that receptor expression is detected 85 ± 2.1% of neurons assessed (n = 48, from 4 donors). The most prevalent coexpression pattern was α3/ß2 (95 ± 4% of neurons with subunits), but α7 subunits were detected in 70 ± 3.4% of neurons. These results suggest that there are not only species differences in the sensory neuron distribution of nAChR currents between rodent and human, but that the subunit composition of the channel underlying human nAChR currents may be different from those in the mouse or rat. PERSPECTIVE: The properties and distribution of nicotine evoked currents in human sensory neurons were markedly different from those previously observed in mice and rats. These observations add additional support to the suggestion that human sensory neurons may be an essential screening tool for those considering moving novel therapeutics targeting primary afferents into clinical trials.

5.
Vaccine ; 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30503081

RESUMO

OBJECTIVE: To determine whether differences in combination DTaP vaccine types at 2, 4 and 6 months of age were associated with mortality (all-cause or non-specific), within 30 days of vaccination. DESIGN: Observational nationwide cohort study. SETTING: Linked population data from the Australian Childhood Immunisation Register and National Death Index. PARTICIPANTS: Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6 months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3 million children in the 2, 4 and 6 month vaccine cohorts, respectively. MAIN OUTCOME MEASURES: Infants were evaluated for the primary outcome of all-cause mortality within 30 days. A secondary outcome was non-specific mortality (unknown cause of death) within 30 days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 'Sudden infant death syndrome', R96 'Other sudden death, cause unknown', R98 'Unattended death', R99 'Other ill-defined and unspecified cause of mortality' or where no cause of death was recorded. RESULTS: The rate of 30 day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6 month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort. CONCLUSION: Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality.

6.
BMJ Open ; 8(10): e023263, 2018 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-30341132

RESUMO

OBJECTIVE: To actively solicit adverse events experienced in the days following immunisation with quadrivalent inactivated influenza vaccine using Australia's near real-time, participant-based vaccine safety surveillance system, AusVaxSafety. DESIGN AND SETTING: Observational cohort study conducted in 194 sentinel surveillance immunisation sites (primary care, hospital and community-based clinics) across Australia. PARTICIPANTS: Individuals aged ≥6 months who received a routine seasonal influenza vaccine at a participating site (n=102 911) and responded to a survey (via short message service or email) sent 3 days after vaccination about adverse events experienced (n=73 892; 71.8%). MAIN OUTCOME MEASURE: Near real-time and cumulative participant-reported rates of any adverse event, fever or medical attendance experienced within 3 days after vaccination overall, by brand, age, pregnancy status and concomitant vaccine receipt. RESULTS: Participant median age was 57 years (range: 6 months to 102 years); 58.1% (n=42 869) were female and 2.7% (n=2018) were pregnant. Near real-time fast initial response cumulative summation and Bayesian analyses of weekly event rates did not demonstrate a safety signal. Children aged 6 months to 4 years had higher event rates (522/6180; 8.4%) compared with older ages; participants aged ≥65 years reported fewer events (1695/28 154; 6.0%). There were no clinically significant differences in safety between brands, by age group or overall. Cumulative data analysis demonstrated that concomitant vaccination was associated with increased rates of fever (2.1% vs 0.8%) and medical attendance (0.8% vs 0.4%), although all rates were low and did not exceed expected levels. CONCLUSIONS: Novel, postmarketing AusVaxSafety surveillance demonstrated comparable and expected safety outcomes for the 2017 quadrivalent inactivated influenza vaccine brands used in Australia. These near real-time, participant-reported data are expected to encourage confidence in vaccine safety and promote uptake.

7.
Neuron ; 99(6): 1274-1288.e6, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30236284

RESUMO

Primary afferents are known to be inhibited by kappa opioid receptor (KOR) signaling. However, the specific types of somatosensory neurons that express KOR remain unclear. Here, using a newly developed KOR-cre knockin allele, viral tracing, single-cell RT-PCR, and ex vivo recordings, we show that KOR is expressed in several populations of primary afferents: a subset of peptidergic sensory neurons, as well as low-threshold mechanoreceptors that form lanceolate or circumferential endings around hair follicles. We find that KOR acts centrally to inhibit excitatory neurotransmission from KOR-cre afferents in laminae I and III, and this effect is likely due to KOR-mediated inhibition of Ca2+ influx, which we observed in sensory neurons from both mouse and human. In the periphery, KOR signaling inhibits neurogenic inflammation and nociceptor sensitization by inflammatory mediators. Finally, peripherally restricted KOR agonists selectively reduce pain and itch behaviors, as well as mechanical hypersensitivity associated with a surgical incision. These experiments provide a rationale for the use of peripherally restricted KOR agonists for therapeutic treatment.

8.
Pain ; 159 Suppl 1: S1-S2, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30113940
9.
Pain ; 159(8): 1484-1493, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29578943

RESUMO

Wind-up is a frequency-dependent increase in the response of spinal cord neurons, which is believed to underlie temporal summation of nociceptive input. However, whether spinoparabrachial neurons, which likely contribute to the affective component of pain, undergo wind-up was unknown. Here, we addressed this question and investigated the underlying neural circuit. We show that one-fifth of lamina I spinoparabrachial neurons undergo wind-up, and provide evidence that wind-up in these cells is mediated in part by a network of spinal excitatory interneurons that show reverberating activity. These findings provide insight into a polysynaptic circuit of sensory augmentation that may contribute to the wind-up of pain's unpleasantness.

10.
BMJ Open ; 8(1): e020232, 2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29391374

RESUMO

INTRODUCTION: Atopic diseases, including food allergy, have become a predominant cause of chronic illness among children in developed countries. In Australia, a rise in hospitalisations among infants coded as anaphylaxis to foods coincided with the replacement of whole-cell pertussis (wP) vaccine with subunit acellular pertussis (aP) vaccine on the national immunisation schedule in the late 1990s. Atopy is characterised by a tendency to mount T helper type 2 (Th2) responses to otherwise innocuous environmental antigens. Compared with infants who receive aP as their first pertussis vaccine, those who receive wP appear less likely to mount Th2 immune responses to either vaccine or extraneous antigens. We therefore speculate that removal of wP from the vaccine schedule contributed to the observed rise in IgE-mediated food allergy among Australian infants. METHODS AND ANALYSIS: This is a retrospective individually matched case-control study among a cohort of Australian children born from 1997 to 1999, the period of transition from wP to aP vaccines; we include in the cohort children listed on Australia's comprehensive population-based immunisation register as having received a first dose of either pertussis vaccine by 16 weeks old. 500 cohort children diagnosed as having IgE-mediated food allergy at specialist allergy clinics will be included as cases. Controls matched to each case by date and jurisdiction of birth and regional socioeconomic index will be sampled from the immunisation register. Conditional logistic regression will be used to estimate OR (±95% CI) of receipt of wP (vs aP) as the first vaccine dose among cases compared with controls. ETHICS AND DISSEMINATION: The study is approved by all relevant human research ethics committees: Western Australia Child and Adolescent Health Services (2015052EP), Women's and Children's Hospital (HREC/15/WCHN/162), Royal Children's Hospital (35230A) and Sydney Children's Hospital Network (HREC/15/SCHN/405). Outcomes will be disseminated through publication and scientific presentation. TRIAL REGISTRATION NUMBER: NCT02490007.


Assuntos
Hipersensibilidade Alimentar/etiologia , Esquemas de Imunização , Vacina contra Coqueluche/efeitos adversos , Vacinação , Coqueluche/prevenção & controle , Adolescente , Anticorpos Antibacterianos/sangue , Antígenos , Estudos de Casos e Controles , Protocolos Clínicos , Vacina contra Difteria, Tétano e Coqueluche , Vacinas contra Difteria, Tétano e Coqueluche Acelular , Feminino , Hipersensibilidade Alimentar/sangue , Humanos , Imunoglobulina E/sangue , Lactente , Masculino , Vacina contra Coqueluche/classificação , Projetos de Pesquisa , Estudos Retrospectivos , Fatores de Risco , Austrália Ocidental
11.
Neurosurgery ; 2018 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-29425330

RESUMO

BACKGROUND: While high-resolution imaging is increasingly used in guiding decisions about surgical interventions for the treatment of trigeminal neuralgia, direct assessment of the extent of vascular contact of the trigeminal nerve is still considered the gold standard for the determination of whether nerve decompression is warranted. OBJECTIVE: To compare intraoperative and magnetic resonance imaging (MRI) findings of the prevalence and severity of vascular compression of the trigeminal nerve in patients without classical trigeminal neuralgia. METHODS: We prospectively recruited 27 patients without facial pain who were undergoing microvascular decompression for hemifacial spasm and had undergone high-resolution preoperative MRI. Neurovascular contact/compression (NVC/C) by artery or vein was assessed both intraoperatively and by MRI, and was stratified into 3 types: simple contact, compression (indentation of the surface of the nerve), and deformity (deviation or distortion of the nerve). RESULTS: Intraoperative evidence of NVC/C was detected in 23 patients. MRI evidence of NVC/C was detected in 18 patients, all of whom had intraoperative evidence of NVC/C. Thus, there were 5, or 28% more patients in whom NVC/C was detected intraoperatively than with MRI (Kappa = 0.52); contact was observed in 4 of these patients and compression in 1 patient. In patients where NVC/C was observed by both methods, there was agreement regarding the severity of contact/compression in 83% (15/18) of patients (Kappa = 0.47). No patients exhibited deformity of the nerve by imaging or intraoperatively. CONCLUSION: There was moderate agreement between imaging and operative findings with respect to both the presence and severity of NVC/C.

12.
Anesth Analg ; 126(5): 1598-1605, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29239949

RESUMO

BACKGROUND: Using labor, epidural analgesia has been linked to a reduced risk of postpartum depression, but the role of labor pain relief in this association remains unclear. The goal of this study was to test the hypothesis that effective epidural analgesia during labor is associated with reduced postpartum depression symptomatology. METHODS: A single, institutional, retrospective, observational cohort design was chosen. The primary outcome was Edinburgh postnatal depression scale (EPDS) score, measured at the 6-week postpartum visit. Subjects included in the final analysis had (1) received labor epidural analgesia; (2) pain assessed during labor both before and during initiation of labor epidural analgesia by 0-10 numeric rating scores; and (3) depression risk assessed by the EPDS and documented at their 6-week postpartum visit. Simple and multiple linear regression was used to identify the best model for assessing the association between pain improvement, defined as percent improvement in pain (PIP), and depression, after adjusting for a history of anxiety or depression, other psychiatric history, abuse, trauma, mode of delivery, and other maternal or fetal comorbid diseases. RESULTS: Two hundred one patients were included in the final analysis. Women with higher improvements in pain were associated with lower EPDS scores (r = 0.025; P = .002). Variables known to be associated with depression (body mass index, anxiety and/or depression, third- and fourth-degree perineal lacerations, and anemia) were significantly correlated with EPDS score and included in the final model. After we adjusted for these covariates, PIP remained a significant predictor of EPDS score (r = 0.49; P = .008), accounting for 6.6% of the variability in postpartum depression scores. The full model including pain, body mass index, anxiety and/or depression, perineal lacerations, and anemia explained 24% of the variability in postpartum depression scores. CONCLUSIONS: Although the extent of labor pain relief by epidural analgesia predicts lower postpartum depression scores, the relative contribution of PIP to risk for postpartum depression symptoms may be less than other established risk factors for depression. These data support that the clinical significance of labor analgesia in the development of postpartum depression needs to be more clearly defined.

13.
Pain Med ; 19(8): 1525-1549, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29077871

RESUMO

Objective: Persistent pain causes untold misery worldwide and is a leading cause of disability. Despite its astonishing prevalence, pain is undertreated, at least in part because existing therapeutics are ineffective or cause intolerable side effects. In this review, we cover new findings about the neurobiology of pain and argue that all but the most transient forms of pain needed to avoid tissue damage should be approached as a disease where a cure can be the goal of all treatment plans, even if attaining this goal is not yet always possible. Design: We reviewed the literature to highlight recent advances in the area of the neurobiology of pain. Results: We discuss barriers that are currently hindering the achievement of this goal, as well as the development of new therapeutic strategies. We also discuss innovations in the field that are creating new opportunities to treat and even reverse persistent pain, some of which are in late-phase clinical trials. Conclusion: We conclude that the confluence of new basic science discoveries and development of new technologies are creating a path toward pain therapeutics that should offer significant hope of a cure for patients and practitioners alike. Classification of Evidence. Our review points to new areas of inquiry for the pain field to advance the goal of developing new therapeutics to treat chronic pain.

14.
Elife ; 62017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28508747

RESUMO

Available evidence indicates voltage-gated Na+ channels (VGSCs) in peripheral sensory neurons are essential for the pain and hypersensitivity associated with tissue injury. However, our understanding of the biophysical and pharmacological properties of the channels in sensory neurons is largely based on the study of heterologous systems or rodent tissue, despite evidence that both expression systems and species differences influence these properties. Therefore, we sought to determine the extent to which the biophysical and pharmacological properties of VGSCs were comparable in rat and human sensory neurons. Whole cell patch clamp techniques were used to study Na+ currents in acutely dissociated neurons from human and rat. Our results indicate that while the two major current types, generally referred to as tetrodotoxin (TTX)-sensitive and TTX-resistant were qualitatively similar in neurons from rats and humans, there were several differences that have important implications for drug development as well as our understanding of pain mechanisms.


Assuntos
Cátions/metabolismo , Gânglios Espinais/metabolismo , Neurônios/metabolismo , Sódio/metabolismo , Canais de Sódio Disparados por Voltagem/metabolismo , Animais , Humanos , Técnicas de Patch-Clamp , Ratos
16.
J Neurosci ; 37(14): 3741-3752, 2017 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-28264976

RESUMO

The δ opioid receptor (δR) is a promising alternate target for pain management because δR agonists show decreased abuse potential compared with current opioid analgesics that target the µ opioid receptor. A critical limitation in developing δR as an analgesic target, however, is that δR agonists show relatively low efficacy in vivo, requiring the use of high doses that often cause adverse effects, such as convulsions. Here we tested whether intracellular retention of δR in sensory neurons contributes to this low δR agonist efficacy in vivo by limiting surface δR expression. Using direct visualization of δR trafficking and localization, we define a phosphatase and tensin homolog (PTEN)-regulated checkpoint that retains δR in the Golgi and decreases surface delivery in rat and mice sensory neurons. PTEN inhibition releases δR from this checkpoint and stimulates delivery of exogenous and endogenous δR to the neuronal surface both in vitro and in vivo PTEN inhibition in vivo increases the percentage of TG neurons expressing δR on the surface and allows efficient δR-mediated antihyperalgesia in mice. Together, we define a critical role for PTEN in regulating the surface delivery and bioavailability of the δR, explain the low efficacy of δR agonists in vivo, and provide evidence that active δR relocation is a viable strategy to increase δR antinociception.SIGNIFICANCE STATEMENT Opioid analgesics, such as morphine, which target the µ opioid receptor (µR), have been the mainstay of pain management, but their use is highly limited by adverse effects and their variable efficacy in chronic pain. Identifying alternate analgesic targets is therefore of great significance. Although the δ opioid receptor (δR) is an attractive option, a critical limiting factor in developing δR as a target has been the low efficacy of δR agonists. Why δR agonists show low efficacy is still under debate. This study provides mechanistic and functional data that intracellular localization of δR in neurons is a key factor that contributes to low agonist efficacy, and presents a proof of mechanism that relocating δR improves efficacy.


Assuntos
Membrana Celular/metabolismo , Neurônios/metabolismo , PTEN Fosfo-Hidrolase/fisiologia , Receptores Opioides delta/metabolismo , Animais , Membrana Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Células PC12 , PTEN Fosfo-Hidrolase/antagonistas & inibidores , Fenantrenos/farmacologia , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/fisiologia , Ratos , Ratos Sprague-Dawley
17.
Cell Calcium ; 62: 16-28, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28109678

RESUMO

We have recently demonstrated that in a rat model of chemotherapy-induced peripheral neuropathy (CIPN), there is a significant decrease in the duration of the depolarization-evoked Ca2+ transient in small diameter, IB4+, and capsaicin-responsive neurons innervating the glabrous skin of the hindpaw. This change was specific to the transient duration and significantly smaller if not undetectable in neurons innervating the dorsal skin of the hindpaw or the skin of the inner thigh. Given the importance of mitochondria in intracellular Ca2+ regulation and the findings of chemotherapy-associated increase in mitotoxicity along the sensory neuron axons, we hypothesized that CIPN is due to both increases and decreases in mitochondria function, with changes manifest in distinct subpopulations of afferents. To begin to test this hypothesis, we used confocal microscopy and Ca2+ imaging in combination with pharmacological manipulations to study paclitaxel-induced changes in retrograde tracer-labeled neurons from naïve, vehicle-treated, and paclitaxel-treated rats. Paclitaxel treatment was not associated with decreased mitochondrial membrane potential or increased superoxide levels in the somata of putative nociceptive glabrous skin neurons. However, it was associated with significant increases in the relative contribution of mitochondria to the control of the evoked Ca2+ transient duration in putative nociceptive glabrous skin neurons, as well as increases in mitotracker and Tom20 staining which reflected an increase in mitochondrial volume. Furthermore, the relative contribution of the sarco-endoplasmic reticulum Ca2+ ATPase to the regulation of the duration of the depolarization evoked Ca2+ transient was also increased in this subpopulation of neurons from paclitaxel treated rats. Our results indicate that the paclitaxel-induced decrease in the duration of the evoked Ca2+ transient is due to both direct and indirect influences of mitochondria. It remains to be determined if and how these changes contribute to the manifestation of CIPN.


Assuntos
Cálcio/metabolismo , Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Nociceptores/efeitos dos fármacos , Paclitaxel/farmacologia , Pele/efeitos dos fármacos , Animais , Masculino , Mitocôndrias/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Nociceptores/metabolismo , Ratos , Ratos Sprague-Dawley , Pele/metabolismo
18.
Cephalalgia ; 37(1): 36-48, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26970607

RESUMO

Aim of investigation Due to compelling evidence in support of links between sex, stress, sympathetic post-ganglionic innervation, dural immune cells, and migraine, our aim was to characterize the impacts of these factors on the type and proportion of immune cells in the dura. Methods Dural immune cells were obtained from naïve or stressed adult male and female Sprague Dawley rats for flow cytometry. Rats with surgical denervation of sympathetic post-ganglionic neurons of the dura were also studied. Results Immune cells comprise ∼17% of all cells in the dura. These included: macrophages/granulocytes ("Macs"; 63.2% of immune cells), dendritic cells (0.88%), T-cells (4.51%), natural killer T-cells (0.51%), natural killer cells (3.08%), and B-cells (20.0%). There were significantly more Macs and fewer B- and natural killer T-cells in the dura of females compared with males. Macs and dendritic cells were significantly increased by stress in males, but not females. In contrast, T-cells were significantly increased in females with a 24-hour delay following stress. Lastly, Macs, dendritic cells, and T-cells were significantly higher in sympathectomized-naïve males, but not females. Conclusions It may not only be possible, but necessary to use different strategies for the most effective treatment of migraine in men and women.


Assuntos
Dura-Máter/imunologia , Transtornos de Enxaqueca/imunologia , Caracteres Sexuais , Estresse Psicológico , Fibras Adrenérgicas , Animais , Linfócitos B/citologia , Contagem de Células , Células Dendríticas/citologia , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Imuno-Histoquímica , Macrófagos/citologia , Masculino , Ratos , Ratos Sprague-Dawley , Simpatectomia , Subpopulações de Linfócitos T/citologia
19.
J Allergy Clin Immunol ; 139(5): 1600-1607.e2, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27554812

RESUMO

BACKGROUND: The ideal age to introduce egg into the infant diet has been debated for the past 2 decades in the context of rising rates of egg allergy. OBJECTIVE: We sought to determine whether regular consumption of egg protein from age 4 to 6 months reduces the risk of IgE-mediated egg allergy in infants with hereditary risk, but without eczema. METHODS: Infants aged 4 to 6 months were randomly allocated to receive daily pasteurized raw whole egg powder (n = 407) or a color-matched rice powder (n = 413) to age 10 months. All infants followed an egg-free diet and cooked egg was introduced to both groups at age 10 months. The primary outcome was IgE-mediated egg allergy defined by a positive pasteurized raw egg challenge and egg sensitization at age 12 months. RESULTS: There was no difference between groups in the percentage of infants with IgE-mediated egg allergy (egg 7.0% vs control 10.3%; adjusted relative risk, 0.75; 95% CI, 0.48-1.17; P = .20). A higher proportion of participants in the egg group stopped taking the study powder because of a confirmed allergic reaction (25 of 407 [6.1%] compared with 6 of 413 [1.5%]). Egg-specific IgG4 levels were substantially higher in the egg group at 12 months (median, 1.22 mgA/L vs control 0.07 mgA/L; P < .0001). CONCLUSIONS: We found no evidence that regular egg intake from age 4 to 6 months substantially alters the risk of egg allergy by age 1 year in infants who are at hereditary risk of allergic disease and had no eczema symptoms at study entry.


Assuntos
Hipersensibilidade a Ovo/prevenção & controle , Proteínas do Ovo/administração & dosagem , Método Duplo-Cego , Hipersensibilidade a Ovo/sangue , Hipersensibilidade a Ovo/diagnóstico , Hipersensibilidade a Ovo/imunologia , Proteínas do Ovo/efeitos adversos , Proteínas do Ovo/imunologia , Ovos/efeitos adversos , Feminino , Humanos , Imunoglobulina E/sangue , Lactente , Masculino , Fatores de Risco
20.
J Neurosci ; 36(42): 10769-10781, 2016 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-27798132

RESUMO

Designer receptors exclusively activated by designer drugs (DREADDs) are an advanced experimental tool that could potentially provide a novel approach to pain management. In particular, expression of an inhibitory (Gi-coupled) DREADD in nociceptors might enable ligand-dependent analgesia. To test this possibility, TRPV1-cre mice were used to restrict expression of Gi-DREADDs to predominantly C-fibers. Whereas baseline heat thresholds in both male and female mice expressing Gi-DREADD were normal, 1 mg/kg clozapine-N-oxide (CNO) produced a significant 3 h increase in heat threshold that returned to baseline by 5 h after injection. Consistent with these behavioral results, CNO decreased action potential firing in isolated sensory neurons from Gi-DREADD mice. Unexpectedly, however, the expression of Gi-DREADD in sensory neurons caused significant changes in voltage-gated Ca2+ and Na+ currents in the absence of CNO, as well as an increase in Na+ channel (NaV1.7) expression. Furthermore, CNO-independent excitatory and inhibitory second-messenger signaling was also altered in these mice, which was associated with a decrease in the analgesic effect of endogenous inhibitory G-protein-coupled receptor activation. These results highlight the potential of this exciting technology, but also its limitations, and that it is essential to identify the underlying mechanisms for any observed behavioral phenotypes. SIGNIFICANCE STATEMENT: DREADD technology is a powerful tool enabling manipulation of activity and/or transmitter release from targeted cell populations. The purpose of this study was to determine whether inhibitory DREADDs in nociceptive afferents could be used to produce analgesia, and if so, how. DREADD activation produced a ligand-dependent analgesia to heat in vivo and a decrease in neuronal firing at the single-cell level. However, we observed that expression of Gi-DREADD also causes ligand-independent changes in ion channel activity and second-messenger signaling. These findings highlight both the potential and the limitations of this exciting technology as well as the necessity to identify the mechanisms underlying any observed phenotype.


Assuntos
Analgesia , Drogas Desenhadas/farmacologia , Nervos Periféricos/metabolismo , Células Receptoras Sensoriais/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Canais de Cálcio/efeitos dos fármacos , Clozapina/farmacologia , Feminino , Masculino , Camundongos , Nociceptores/efeitos dos fármacos , Medição da Dor/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Técnicas de Patch-Clamp , Canais de Potássio de Abertura Dependente da Tensão da Membrana/efeitos dos fármacos , Receptores Acoplados a Proteínas-G/efeitos dos fármacos , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Canais de Cátion TRPV/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA