Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
PLoS Pathog ; 19(12): e1011797, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38079450

RESUMEN

The impact of the host immune environment on parasite transcription and fitness is currently unknown. It is widely held that hookworm infections have an immunomodulatory impact on the host, but whether the converse is true remains unclear. Immunity against adult-stage hookworms is largely mediated by Type 2 immune responses driven by the transcription factor Signal Transducer and Activator of Transcription 6 (STAT6). This study investigated whether serial passage of the rodent hookworm Nippostrongylus brasiliensis in STAT6-deficient mice (STAT6 KO) caused changes in parasites over time. After adaptation to STAT6 KO hosts, N. brasiliensis increased their reproductive output, feeding capacity, energy content, and body size. Using an improved N. brasiliensis genome, we found that these physiological changes corresponded with a dramatic shift in the transcriptional landscape, including increased expression of gene pathways associated with egg production, but a decrease in genes encoding neuropeptides, proteases, SCP/TAPS proteins, and transthyretin-like proteins; the latter three categories have been repeatedly observed in hookworm excreted/secreted proteins (ESPs) implicated in immunosuppression. Although transcriptional changes started to appear in the first generation of passage in STAT6 KO hosts for both immature and mature adult stages, downregulation of the genes putatively involved in immunosuppression was only observed after multiple generations in this immunodeficient environment. When STAT6 KO-adapted N. brasiliensis were reintroduced to a naive WT host after up to 26 generations, this progressive change in host-adaptation corresponded to increased production of inflammatory cytokines by the WT host. Surprisingly, however, this single exposure of STAT6 KO-adapted N. brasiliensis to WT hosts resulted in worms that were morphologically and transcriptionally indistinguishable from WT-adapted parasites. This work uncovers remarkable plasticity in the ability of hookworms to adapt to their hosts, which may present a general feature of parasitic nematodes.


Asunto(s)
Ancylostomatoidea , Infecciones por Uncinaria , Ratones , Animales , Citocinas , Nippostrongylus , Factor de Transcripción STAT6/genética
2.
Am J Respir Cell Mol Biol ; 66(3): 252-259, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34784491

RESUMEN

Tissue damage in the upper and lower airways caused by mechanical abrasion, noxious chemicals, or pathogenic organisms must be followed by rapid restorative processes; otherwise, persistent immunopathology and disease may ensue. This review will discuss evidence for the important role served by trefoil factor (TFF) family members in healthy and diseased airways of humans and rodents. Collectively, these peptides serve to both maintain and restore homeostasis through their regulation of the mucous layer and their control of cell motility, cell differentiation, and immune function in the upper and lower airways. We will also discuss important differences in which trefoil member tracks with homeostasis and disease between humans and mice, which poses a challenge for research in this area. Moreover, we discuss new evidence supporting newly identified receptor binding partners in the leucine-rich repeat and immunoglobulin-like domain-containing NoGo (LINGO) family in mediating the biological effects of TFF proteins in mouse models of epithelial repair and infection. Recent advances in our knowledge regarding TFF peptides suggest that they may be reasonable therapeutic targets in the treatment of upper and lower airway diseases of diverse etiologies. Further work understanding their role in airway homeostasis, repair, and inflammation will benefit from these newly uncovered receptor-ligand interactions.


Asunto(s)
Factores Trefoil , Animales , Pulmón/metabolismo , Ratones , Péptidos/metabolismo , Proteínas , Factor Trefoil-2
3.
Headache ; 55(4): 600-4, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25790126

RESUMEN

BACKGROUND: Photophobia is a debilitating feature of many headache disorders. OVERVIEW: Clinical and preclinical research has identified several potential pathways involved in enhanced light sensitivity. Some of these structures include trigeminal afferents in the eye, second-order neurons in the trigeminal nucleus caudalis, third-order neurons in the posterior thalamus, modulatory neurons in the hypothalamus, and fourth-order neurons in the visual and somatosensory cortices. It is unclear to what degree each site plays a role in establishing the different temporal patterns of photophobia across different disorders. Peptides such as calcitonin gene-related peptide and pituitary adenylate cyclase-activating polypeptide may play a role in photophobia at multiple levels of the visual and trigeminal pathways. CONCLUSION: While our understanding of photophobia has greatly improved in the last decade, there are still unanswered questions. These answers will help us develop new therapies to provide relief to patients with primary headache disorders.


Asunto(s)
Cefaleas Primarias/diagnóstico , Cefaleas Primarias/epidemiología , Fotofobia/diagnóstico , Fotofobia/epidemiología , Humanos , Nervio Trigémino/patología , Vías Visuales/patología
4.
bioRxiv ; 2023 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-37461610

RESUMEN

The authors have withdrawn this manuscript owing to inaccuracies in the calculation of tuft cell numbers and errors in the selection of immunofluorescence images used to support our claims. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

5.
Res Sq ; 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38076920

RESUMEN

Skin employs interdependent cellular networks to facilitate barrier integrity and host immunity through ill-defined mechanisms. This study demonstrates that manipulation of itch-sensing neurons bearing the Mas-related G protein-coupled receptor A3 (MrgprA3) drives IL-17+ γδ T cell expansion, epidermal thickening, and resistance to the human pathogen Schistosoma mansoni through mechanisms that require myeloid antigen presenting cells (APC). Activated MrgprA3 neurons instruct myeloid APCs to downregulate interleukin 33 (IL-33) and up-regulate TNFα partially through the neuropeptide calcitonin gene related peptide (CGRP). Strikingly, cell-intrinsic deletion of IL-33 in myeloid APC basally alters chromatin accessibility at inflammatory cytokine loci and promotes IL-17/23-dependent epidermal thickening, keratinocyte hyperplasia, and resistance to helminth infection. Our findings reveal a previously undescribed mechanism of intercellular cross-talk wherein "itch" neuron activation reshapes myeloid cytokine expression patterns to alter skin composition for cutaneous immunity against invasive pathogens.

6.
Mucosal Immunol ; 15(6): 1199-1211, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35538230

RESUMEN

Helminths are remarkably successful parasites that can invade various mammalian hosts and establish chronic infections that can go unnoticed for years despite causing severe tissue damage. To complete their life cycles, helminths migrate through multiple barrier sites that are densely populated by a complex array of hematopoietic and non-hematopoietic cells. While it is clear that type 2 cytokine responses elicited by immune cells promote worm clearance and tissue healing, the actions of non-hematopoietic cells are increasingly recognized as initiators, effectors and regulators of anti-helminth immunity. This review will highlight the collective actions of specialized epithelial cells, stromal niches, stem, muscle and neuroendocrine cells as well as peripheral neurons in the detection and elimination of helminths at mucosal sites. Studies dissecting the interactions between immune and non-hematopoietic cells will truly provide a better understanding of the mechanisms that ensure homeostasis in the context of helminth infections.


Asunto(s)
Helmintiasis , Helmintos , Parásitos , Animales , Mebendazol , Interacciones Huésped-Parásitos , Mamíferos
7.
J Leukoc Biol ; 111(1): 209-221, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-33857344

RESUMEN

Communication between the nervous and immune systems serves a key role in host-protective immunity at mucosal barrier sites including the respiratory tract. In these tissues, neuroimmune interactions operate in bidirectional circuits that can sense and respond to mechanical, chemical, and biologic stimuli. Allergen- or helminth-induced products can produce airway inflammation by direct action on nociceptive afferents and adjacent tissues. The activity of nociceptive afferents can regulate innate and adaptive immune responses via neuropeptides and neurotransmitter signaling. This review will summarize recent work investigating the role of neuropeptides CGRP, VIP, neuromedins, substance P, and neurotransmitters dopamine and the B2-adrenoceptor agonists epinepherine/norepinepherine, each of which influence type 2 immunity by instructing mast cell, innate lymphoid cell type 2, dendritic cell, and T cell responses, both in the airway and the draining lymph node. Afferents in the airway also contain receptors for alarmins and cytokines, allowing their activity to be modulated by immune cell secreted products, particularly those secreted by mast cells. Taken together, we propose that further investigation of how immunoregulatory neuropeptides shape respiratory inflammation in experimental systems may reveal novel therapeutic targets for addressing the increasing prevalence of chronic airway disease in humans.


Asunto(s)
Hipersensibilidad/inmunología , Inflamación/inmunología , Neuroinmunomodulación , Neuropéptidos/inmunología , Animales , Humanos , Inmunidad Innata , Membrana Mucosa/inmunología , Sistema Respiratorio/inmunología
8.
Mol Biochem Parasitol ; 251: 111511, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36007683

RESUMEN

The gastrointestinal (GI) nematode Strongyloides stercoralis (S.s.) causes human strongyloidiasis, a potentially life-threatening disease that currently affects over 600 million people globally. The uniquely pernicious aspect of S.s. infection, as compared to all other GI nematodes, is its autoinfective larval stage (L3a) that maintains a low-grade chronic infection, allowing undetectable persistence for decades. Infected individuals who are administered glucocorticoid therapy can develop a rapid and often lethal hyperinfection syndrome within days. Hyperinfection patients often present with dramatic increases in first- and second-stage larvae and L3a in their GI tract, with L3a widely disseminating throughout host organs leading to sepsis. How glucocorticoid administration drives hyperinfection remains a critical unanswered question; specifically, it is unknown whether these steroids promote hyperinfection through eliminating essential host protective mechanisms and/or through dysregulating parasite development. This current deficiency in understanding is largely due to the previous absence of a genetically defined mouse model that would support all S.s. life-cycle stages and the lack of successful approaches for S.s. genetic manipulation. However, there are currently new possibilities through the recent demonstration that immunodeficient NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice support sub-clinical infections that can be transformed to lethal hyperinfection syndrome following glucocorticoid administration. This is coupled with advances in transcriptomics, transgenesis, and gene inactivation strategies that now allow rigorous scientific inquiry into S.s. biology. We propose that combining in vivo manipulation of host immunity and deep immunoprofiling strategies with the latest advances in S.s. transcriptomics, piggyBac transposon-mediated transgene insertion, and CRISPR/Cas-9-mediated gene inactivation will facilitate new insights into the mechanisms that could be targeted to block lethality in humans with S.s. hyperinfection.


Asunto(s)
Parásitos , Strongyloides stercoralis , Estrongiloidiasis , Animales , Glucocorticoides/efectos adversos , Humanos , Larva , Ratones , Ratones Endogámicos NOD , Strongyloides stercoralis/genética
9.
PLoS Negl Trop Dis ; 15(10): e0009550, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34662329

RESUMEN

Helminth infections, including hookworms and Schistosomes, can cause severe disability and death. Infection management and control would benefit from identification of biomarkers for early detection and prognosis. While animal models suggest that Trefoil Factor Family proteins (TFF2 and TFF3) and interleukin-33 (IL-33) -driven type 2 immune responses are critical mediators of tissue repair and worm clearance in the context of hookworm infection, very little is known about how they are modulated in the context of human helminth infection. We measured TFF2, TFF3, and IL-33 levels in serum from patients in Brazil infected with Hookworm and/or Schistosomes, and compared them to endemic and non-endemic controls. TFF2 was specifically elevated by Hookworm infection in females, not Schistosoma or co-infection. This elevation was correlated with age, but not worm burden. TFF3 was elevated by Schistosoma infection and found to be generally higher in females. IL-33 was not significantly altered by infection. To determine if this might apply more broadly to other species or regions, we measured TFFs and cytokine levels (IFNγ, TNFα, IL-33, IL-13, IL-1ß, IL-17A, IL-22, and IL-10) in both the serum and urine of Nigerian school children infected with S. haematobium. We found that serum levels of TFF2 and 3 were reduced by infection, likely in an age dependent manner. In the serum, only IL-10 and IL-13 were significantly increased, while in urine IFN-γ, TNF-α, IL-13, IL-1ß, IL-22, and IL-10 were significantly increased in by infection. Taken together, these data support a role for TFF proteins in human helminth infection.


Asunto(s)
Helmintiasis/sangre , Helmintos/clasificación , Helmintos/fisiología , Factor Trefoil-2/sangre , Factor Trefoil-3/sangre , Adolescente , Adulto , Factores de Edad , Animales , Brasil , Niño , Estudios de Cohortes , Femenino , Helmintiasis/parasitología , Helmintos/genética , Humanos , Interferón gamma/sangre , Interleucina-10/sangre , Interleucina-33/sangre , Masculino , Persona de Mediana Edad , Especificidad de la Especie , Factor de Necrosis Tumoral alfa/sangre , Adulto Joven
10.
Neuroscience ; 415: 121-134, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31295530

RESUMEN

How obesity exacerbates migraine and other pain disorders remains unknown. Trigeminal nociceptive processing, crucial in migraine pathophysiology, is abnormal in mice with diet induced obesity. However, it is not known if this is also true in genetic models of obesity. We hypothesized that obese mice, regardless of the model, have trigeminal hyperalgesia. To test this, we first evaluated trigeminal thermal nociception in leptin deficient (ob/ob) and control mice using an operant thermal assay. Unexpectedly, we found significant hypoalgesia in ob/ob mice. Because thermal hypoalgesia also occurs in mice lacking the transient receptor potential vanilloid 1 channel (TRPV1), we tested capsaicin-evoked trigeminal nociception. Ob/ob and control mice had similar capsaicin-evoked nocifensive behaviors, but ob/ob mice were significantly less active after a facial injection of capsaicin than were diet-induced obese mice or lean controls. Conditioned place aversion in response to trigeminal stimulation with capsaicin was similar in both genotypes, indicating normal negative affect and pain avoidance. Supporting this, we found no difference in TRPV1 expression in the trigeminal ganglia of ob/ob and control mice. Finally, we assessed the possible contribution of hyperphagia, a hallmark of leptin deficiency, to the behavior observed in the operant assay. Ob/ob and lean control mice had similar reduction of intake when quinine or capsaicin was added to the sweetened milk, excluding a significant contribution of hyperphagia. In summary, ob/ob mice, unlike mice with diet-induced obesity, have trigeminal thermal hypoalgesia but normal responses to capsaicin, suggesting specificity in the mechanisms by which leptin acts in pain processing.


Asunto(s)
Hiperalgesia/fisiopatología , Obesidad/fisiopatología , Ganglio del Trigémino/fisiología , Animales , Conducta/efectos de los fármacos , Capsaicina/farmacología , Dieta , Ingestión de Alimentos/efectos de los fármacos , Leptina/deficiencia , Locomoción/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Obesos , Modelos Animales , Nocicepción/fisiología , Dolor , Dimensión del Dolor , Quinina , Canales Catiónicos TRPV/metabolismo , Ganglio del Trigémino/metabolismo
11.
Mol Pain ; 4: 43, 2008 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-18828909

RESUMEN

BACKGROUND: Rodent models of orofacial pain typically use methods adapted from manipulations to hind paw; however, limitations of these models include animal restraint and subjective assessments of behavior by the experimenter. In contrast to these methods, assessment of operant responses to painful stimuli has been shown to overcome these limitations and expand the breadth of interpretation of the behavioral responses. In the current study, we used an operant model based on a reward-conflict paradigm to assess nociceptive responses in three strains of mice (SKH1-Hrhr, C57BL/6J, TRPV1 knockout). We previously validated this operant model in rats and hypothesized in this study that wild-type mice would demonstrate a similar thermal stimulus-dependent response and similar operant pain behaviors. Additionally, we evaluated the effects on operant behaviors of mice manipulated genetically (e.g., TRPV1 k.o.) or pharmacologically with resiniferatoxin (RTX), a lesioning agent for TRPV1-expressing neurons. During the reward-conflict task, mice accessed a sweetened milk reward solution by voluntarily position their face against a neutral or heated thermode (37-55 degrees C). RESULTS: As the temperature of the thermal stimulus became noxiously hot, reward licking events in SKH1-Hrhr and C57BL/6J mice declined while licking events in TRPV1 k.o. mice were insensitive to noxious heat within the activation range of TRPV1 (37-52 degrees C). All three strains displayed nocifensive behaviors at 55 degrees C, as indicated by a significant decrease in reward licking events. Induction of neurogenic inflammation by topical application of capsaicin reduced licking events in SKH1-Hrhr mice, and morphine rescued this response. Again, these results parallel what we previously documented using rats in this operant system. Following intracisternal treatment with RTX, C57BL/6J mice demonstrated a block of noxious heat at both 48 and 55 degrees C. RTX-treated TRPV1 k.o. mice and all vehicle-treated mice displayed similar reward licking events as compared to the pre-treatment baseline levels. Both TRPV1 k.o. and RTX-treated C57BL/6J had complete abolishment of eye-wipe responses following corneal application of capsaicin. CONCLUSION: Taken together, these results indicate the benefits of using the operant test system to investigate pain sensitivity in mice. This ability provides an essential step in the development of new treatments for patients suffering from orofacial pain disorders.


Asunto(s)
Condicionamiento Operante , Dolor Facial/etiología , Neuronas/química , Canales Catiónicos TRPV/deficiencia , Canales Catiónicos TRPV/fisiología , Animales , Reacción de Prevención , Modelos Animales de Enfermedad , Diterpenos/farmacología , Calor , Ratones , Ratones Noqueados , Dimensión del Dolor
12.
Behav Brain Res ; 187(2): 478-82, 2008 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-17976833

RESUMEN

Environmental enrichment reduces reactivity to stressor and could also modulate pain perception. In this study we sought to compare the effects of enriched and standard housing on temperature perception. In an operant assay, rats housed in an enriched environment exhibited significantly lower sensitivities to thermal stimuli and displayed less exploratory behavior in a rearing chamber. These findings indicate that environmental enrichment can significantly affect temperature perception, likely through stress-related mechanisms.


Asunto(s)
Condicionamiento Operante/fisiología , Ambiente , Conducta Exploratoria/fisiología , Umbral del Dolor/fisiología , Sensación Térmica/fisiología , Animales , Reacción de Prevención/fisiología , Masculino , Ratas , Ratas sin Pelo , Ratas Wistar
13.
Behav Brain Funct ; 3: 49, 2007 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-17883847

RESUMEN

BACKGROUND: Management of pain involves a balance between inhibition of pain and minimization of side effects; therefore, in developing new analgesic compounds, one must consider the effects of treatment on both pain processing and behavior. The purpose of this study was to evaluate the effects of the mu and kappa-2 opioid receptor agonists on general and pain behavioral outcomes. METHODS: As a general behavioral assessment, we modified the cylinder rearing assay and recorded the number and duration of rearing events. Thermal sensitivity was evaluated using either a reflexive measure of hindpaw withdrawal latency to a radiant heat source or using an orofacial operant thermal assay. Acetic acid-induced visceral pain and capsaicin-induced neurogenic inflammatory pain were used as painful stimuli. The mu-opioid receptor agonist, morphine or the kappa-2 receptor agonist GR89696 was administered 30 min prior to testing. A general linear model repeated measures analysis was completed for baseline session comparisons and an analysis of variance was used to evaluate the effects of treatment on each outcome measure (SPSS Inc). When significant differences were found, post-hoc comparisons were made using the Tukey honestly significant difference test. *P < 0.05 was considered significant in all instances. RESULTS: We found that morphine and GR89,696 dose-dependently decreased the number of reaching events and rearing duration. Rearing behavior was not affected at 0.5 mg/kg for morphine, 1.25 x 10-4 mg/kg for GR89,696. Hindpaw thermal sensitivity was significantly increased only at the highest doses for each drug. At the highest dose that did not significantly influence rearing behavior, we found that visceral and neurogenic inflammatory pain was not affected following GR89,696 administration and morphine was only partially effective for blocking visceral pain. CONCLUSION: This study demonstrated that high levels of the opioids produced significant untoward effects and made distinguishing an analgesic versus a more general effect more difficult. Quantification of rearing behavior in conjunction with standard analgesic assays can help in gaining a better appreciation of true analgesic efficacy of experimental drugs.

14.
Mol Pain ; 2: 37, 2006 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-17166284

RESUMEN

BACKGROUND: A hallmark of many orofacial pain disorders is cold sensitivity, but relative to heat-related pain, mechanisms of cold perception and the development of cold allodynia are not clearly understood. Molecular mediators of cold sensation such as TRPM8 have been recently identified and characterized using in vitro studies. In this study we characterized operant behavior with respect to individually presented cold stimuli (24, 10, 2, and -4 degrees C) and in a thermal preference task where rats chose between -4 and 48 degrees C stimulation. We also evaluated the effects of menthol, a TRPM8 agonist, on operant responses to cold stimulation (24, 10, and -4 degrees C). Male and female rats were trained to drink sweetened milk while pressing their shaved faces against a thermode. This presents a conflict paradigm between milk reward and thermal stimulation. RESULTS: We demonstrated that the cold stimulus response function was modest compared to heat. There was a significant effect of temperature on facial (stimulus) contacts, the ratio of licking contacts to stimulus contacts, and the stimulus duration/contact ratio. Males and females differed only in their facial contacts at 10 degrees C. In the preference task, males preferred 48 degrees C to -4 degrees C, despite the fact that 48 degrees C and -4 degrees C were equally painful as based on their reward/stimulus and duration/contact ratios. We were able to induce hypersensitivity to cold using menthol at 10 degrees C, but not at 24 or -4 degrees C. CONCLUSION: Our results indicate a strong role for an affective component in processing of cold stimuli, more so than for heat, which is in concordance with human psychophysical findings. The induction of allodynia with menthol provides a model for cold allodynia. This study provides the basis for future studies involving orofacial pain and analgesics, and is translatable to the human experience.


Asunto(s)
Frío , Condicionamiento Operante , Dolor Facial/etiología , Sensación Térmica , Animales , Femenino , Calor , Humanos , Masculino , Mentol/farmacología , Modelos Animales , Ratas , Canales Catiónicos TRPM/agonistas , Temperatura
15.
Behav Brain Res ; 170(2): 308-15, 2006 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-16675039

RESUMEN

Investigations of new analgesic treatments ideally are coupled with the use of compassionate methods for pain testing in animals. Recently, we described a novel operant thermal testing device that can be used to quantify orofacial pain. The objective of the current study was to differentiate thermal allodynia from hyperalgesia using this operant thermal assay. Rats were trained to complete a task whereby they had a conflict between a positive reward and tolerance for thermal nociceptive stimulation. They were subjected to cool to hot temperatures (24-45 degrees C) and evaluated under naïve (untreated), capsaicin cream (0.075%), capsaicin/morphine, or morphine test conditions. The following outcome measures were evaluated: reward intake; licking contacts; facial contacts; time to complete 25, 50, and 75% of the events (licks and face contacts); facial contact duration; ratio of reward/stimulus contacts; and ratio of facial contact duration/event. Capsaicin produced an increase in mechanical sensitivity and a significant thermal allodynic effect at 42 degrees C and hyperalgesic effect at 45 degrees C. These effects were blocked with morphine pre-treatment. The temporal profile for completing the task was also significantly altered following capsaicin treatment. These data demonstrate that using the operant orofacial assay in conjunction with capsaicin cream can provide a reproducible, sensitive, minimally invasive, and powerful approach for quantifying and studying enhanced thermal pain within the trigeminal system. This technique provides an alternative to reflex tests of orofacial sensitivity, and it presents a pivotal link for translating basic pain research into clinic trial strategies.


Asunto(s)
Capsaicina/efectos adversos , Condicionamiento Operante/efectos de los fármacos , Hiperalgesia/inducido químicamente , Umbral del Dolor/efectos de los fármacos , Análisis de Varianza , Animales , Conducta Animal/efectos de los fármacos , Condicionamiento Operante/fisiología , Hiperalgesia/fisiopatología , Masculino , Dimensión del Dolor/métodos , Ratas , Ratas Sprague-Dawley
16.
Neuroscience ; 331: 99-108, 2016 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-27328418

RESUMEN

Migraine affects predominantly women. Furthermore, epidemiological studies suggest that obesity is a risk factor for migraine and this association is influenced by sex. However, the biological basis for this bias is unclear. To address this issue, we assessed light avoidant behavior, a surrogate of photophobia, in female C57BL/6J mice fed regular diet (RD) or high-fat diet (HFD, 60% kcal from fat). We first assessed sex differences in basal photophobia in 20-25-week-old mice and found that both obese and lean females spent significantly less time in light than their male counterparts. Next, we assessed photophobia evoked by trigeminal stimulation with intradermal capsaicin. Females at 20-25weeks of age did not display capsaicin-evoked photophobic behavior unless they had diet-induced obesity. When we tested 8-11-week-old females to determine if the diet alone could be responsible for this effect, we found that both HFD and RD 8-11-week-old females exhibit capsaicin-evoked photophobic behavior. This is in contrast to what we have previously shown in males and indicates a sex difference in the photophobic behavior of mice. Comparison of 20-25-week-old RD mice with 8-11-week-old RD mice suggests that age or age-related weight gain may contribute to capsaicin-evoked photophobic behavior in males, but not in females. These findings suggest that obesity exacerbates photophobia in both sexes, but additional work is needed to understand the sex- and age-specific mechanisms that may contribute to photophobia and trigeminal pain.


Asunto(s)
Obesidad/fisiopatología , Fotofobia/fisiopatología , Caracteres Sexuales , Envejecimiento/fisiología , Envejecimiento/psicología , Análisis de Varianza , Animales , Reacción de Prevención , Capsaicina , Estudios de Cohortes , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Femenino , Masculino , Ratones Endogámicos C57BL , Trastornos Migrañosos/fisiopatología , Actividad Motora/fisiología , Obesidad/complicaciones , Estimulación Luminosa , Fotofobia/etiología , Distribución Aleatoria , Factores de Tiempo
17.
Pain ; 157(1): 235-246, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26397933

RESUMEN

Obesity is associated with several pain disorders including headache. The effects of obesity on the trigeminal nociceptive system, which mediates headache, remain unknown. We used 2 complementary mouse models of obesity (high-fat diet and leptin deficiency) to examine this. We assessed capsaicin-induced nocifensive behavior and photophobia in obese and control mice. Calcium imaging was used to determine the effects of obesity on the activity of primary trigeminal afferents in vitro. We found that obese mice had a normal acute response to a facial injection of capsaicin, but they developed photophobic behavior at doses that had no effect on control mice. We observed higher calcium influx in cultured trigeminal ganglia neurons from obese mice and a higher percentage of medium to large diameter capsaicin-responsive cells. These findings demonstrate that obesity results in functional changes in the trigeminal system that may contribute to abnormal sensory processing. Our findings provide the foundation for in-depth studies to improve the understanding of the effects of obesity on the trigeminal system and may have implications for the pathophysiology of headache disorders.


Asunto(s)
Neuronas/fisiología , Obesidad/fisiopatología , Dolor/fisiopatología , Trastornos de la Sensación/fisiopatología , Ganglio del Trigémino/fisiopatología , Animales , Conducta Animal/fisiología , Capsaicina/farmacología , Ratones , Ratones Obesos , Neuronas/efectos de los fármacos , Obesidad/complicaciones , Dolor/complicaciones , Sensación/efectos de los fármacos , Trastornos de la Sensación/complicaciones , Células Receptoras Sensoriales/efectos de los fármacos , Células Receptoras Sensoriales/fisiología , Ganglio del Trigémino/efectos de los fármacos
18.
Pain ; 116(3): 386-395, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15982812

RESUMEN

Orofacial pain has been well-characterized clinically, but evaluation of orofacial pain in animals has not kept pace. The objective of this study was to describe behavioral responses to facial thermal stimulation and inflammation with/without an analgesic using a novel operant paradigm. Animals were trained to voluntarily place their face against a stimulus thermode (37.7-57.2 degrees C) providing access to positive reinforcement. These contingencies present a conflict between positive reward and tolerance for nociceptive stimulation. Inflammation was induced and morphine was provided as an analgesic in a subset of animals. Six outcome measures were determined: reward intake, reward licking contacts, stimulus facial contacts, facial contact duration, ratio of reward/stimulus contacts, and ratio of facial contact duration/event. Animals displayed aversive behaviors to the higher temperatures, denoted by a significant decrease in reward intake, total facial contact duration, and reward licking events. The number of facial contacts increased with increasing temperature, replacing long drinking bouts with more frequent short drinks, as reflected by a low ratio of facial contact duration/event. The number of reward licking/facial contact events was significantly decreased as the thermal stimulus intensity increased, providing another pain index derived from this operant method. These outcomes were significantly affected in the direction of increased nociception following inflammation, and these indices of hyperalgesia were reversed with morphine administration. These data reflect an orofacial pain behavior profile that was based on an animal's responses in an operant escape paradigm. This technique allows evaluation of nociceptive processing and modulation throughout the neuraxis.


Asunto(s)
Condicionamiento Operante/fisiología , Dolor Facial/fisiopatología , Calor , Umbral del Dolor/fisiología , Analgésicos Opioides/administración & dosificación , Animales , Conducta Animal , Chondrus , Condicionamiento Operante/efectos de los fármacos , Reacción de Fuga/efectos de los fármacos , Reacción de Fuga/fisiología , Cara/inervación , Dolor Facial/inducido químicamente , Dolor Facial/tratamiento farmacológico , Masculino , Morfina/administración & dosificación , Dimensión del Dolor/métodos , Umbral del Dolor/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Recompensa , Nervio Trigémino/fisiopatología
19.
Am Surg ; 68(7): 628-30, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12132747

RESUMEN

A prospective assessment was performed to determine the incidence of anal complications after ileoanal J-pouch anastomosis procedures for ulcerative colitis (UC) and familial adenomatous polyposis (FAP). From 1989 to 2000, 75 patients (50 male and 25 female) underwent proctocolectomy and ileal pouch-anal anastomosis with temporary loop ileostomy for UC (N = 68) and FAP (N = 7). Overall 33 patients (44%) developed anal complications postoperatively. Nineteen patients (25%) had mild anal stenosis amenable to digital dilatation in the office. Ten patients (13%) had severe anal stenosis requiring operative dilatation. Ileostomy closure was delayed longer than 3 months in four patients because of anal stenosis. One patient never had his ileostomy closed secondary to severe anal stenosis. Anal fissures developed in one patient that resolved with conservative treatment. Three patients developed fistula-in-ano and one patient developed a pouch-vaginal fistula. Of these four patients two later manifested signs of Crohn's disease. Four patients developed perirectal abscesses (three without fistulas) that were treated with incision and drainage. Two patients had presacral (anastomotic) abscesses; one patient was treated with temporary anastomotic diversion and the other underwent a permanent ileostomy and pouch resection. Both of these patients were later diagnosed with Crohn's disease. Anal complications developed in 17 of 41 (41%) handsewn anastomoses, 16 of 34 (47%) stapled anastomoses, three of seven (43%) patients with FAP, and 30 of 68 (44%) patients with UC. Operative technique and disease type did not significantly correlate with the type of anal complication. However, hand-sewn anastomoses had a higher incidence of severe strictures and FAP patients did not develop anal abscesses, fistulas, or fissures. Forty-five per cent of our patients with abscesses/fistulas and all of our patients with presacral abscesses from anastomotic dehiscence were later diagnosed with Crohn's disease. Anal complications after ileoanal J-pouch anastomosis are relatively common.


Asunto(s)
Poliposis Adenomatosa del Colon/cirugía , Enfermedades del Ano/etiología , Colitis Ulcerosa/cirugía , Proctocolectomía Restauradora/efectos adversos , Absceso/etiología , Adolescente , Adulto , Constricción Patológica/etiología , Femenino , Fisura Anal/etiología , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Proctocolectomía Restauradora/métodos , Fístula Rectal/etiología , Suturas/efectos adversos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA