RESUMO
BACKGROUND: There are differing opinions with regard to the specific mechanical forces related to contraction of the frontalis muscle and how it exerts its effects on eyebrow motion. OBJECTIVES: To perform a detailed anatomic and clinical study of the frontalis muscle in cadavers and patients to better define the movement of the frontalis muscle. METHODS: This study consisted of four arms that included: 1) dynamic ecography to evaluate movement of the frontalis muscle, 2) anatomical study of the relationship between the frontalis muscle and the deep fascia, 3) histological study to define the frontalis muscle attachments and 4) clinical study to evaluate the action of the frontalis muscle in patients undergoing a temporal face lift. RESULTS: The frontalis muscle was attached, inserted, and adhered to the deep layer of the fascia in the superior cephalic and middle third of the forehead. In the superior cephalic third of the forehead, loose areolar tissue was observed deep to the frontalis muscle and the deep layer of the fascia. Within the middle third of the forehead, the deep layer of the galea was fused with the periosteum and firmly adhered. In the inferior caudal third of the forehead, the frontalis muscle was separated from the deep galeal aponeurosis and interdigitated with the orbicularis muscle. When the frontal muscle end was dissected free from the deep fascia by approximately 1â cm and pulled upward, no movement of the eyebrows was observed. Eyebrow elevation was only achieved by pulling on the inferior part of the muscle. CONCLUSIONS: Frontalis muscle movement occurs from the inferior caudal end towards the mid part of the muscle as it contracts centripetally on its superficial layer sliding over the deep part strongly attached to the deep fascia.
RESUMO
Esta revisión busca proporcionar a los profesionales de la salud una mayor comprensión del dolor para su actividad clínica-asistencial. Basados en la hipóte-sis de neuroplasticidad presentada inicialmente por Ramón y Cajal y la teoría de la compuerta en la vía dolorosa presentada por Melzack y Wall, se ha ela-borado una revisión bibliográfica con el objetivo de abordar la modulación de la vía nociceptiva desde un punto de vista fisiopatológico. Asimismo, se presen-tan los principales resultados obtenidos durante los últimos años en nuestro laboratorio usando ratas Wistar hembras como modelo de dolor experimental. Finalmente, se describe un circuito original de modu-lación central a nivel del subnúcleo caudal del trigé-mino con una visión integral de los componentes del sistema nociceptivo orofacial, para ayudar al clínico a comprender situaciones de sensibilización central con perpetuación del dolor y cómo paulatinamente el sistema nervioso central pone en marcha un sistema de modulación para adaptarse y alcanzar un estado similar al basal (AU)
This review aims to provide health professionals with a better understanding of pain for their clinical-care activity. Based on the neuroplasticity hypothesis initially presented by Ramón and Cajal, and the gate theory in the pain pathway presented by Melzack and Wall, a literature review has been carried out with the aim of addressing the modulation of the nociceptive pathway from a pathophysiological point of view. The main results obtained in recent years in our laboratory using female Wistar rats as an experimental pain model are also presented. Finally, an original central modulation circuit at the level of the caudal trigeminal subnucleus is described with a comprehensive view of the components of the orofacial nociceptive system, to help the clinician to understand situations of central sensitization with perpetuation of pain and how the central nervous system gradually sets in motion a modulation system to adapt and reach a state similar to the basal one (AU)
Assuntos
Humanos , Animais , Ratos , Dor/fisiopatologia , Sistema Nervoso Central/fisiologia , Nociceptividade/fisiologia , Plasticidade Neuronal/fisiologia , Astrócitos , Ratos Wistar , Hiperalgesia/fisiopatologia , InterneurôniosRESUMO
Objective: Laparoscopic colectomy has gained acceptance as a standard treatment for benign and malignant colorectal disease, such as diverticular disease and cancer, among others. Same as in open surgery, the laparoscopic approach carries a low risk of small bowel obstruction in the postoperative period, but in laparoscopic surgery, internal hernia after laparoscopic left colectomy may be a cause of small bowel obstruction with a significant risk of morbidity and mortality. This rare complication may be prevented with routine closure of the mesenteric defects created during the colectomy. Methods: We present four cases of internal herniation after laparoscopic colectomy. Two cases were after laparoscopic left colectomy and two after laparoscopic low anterior resection. All four cases had full splenic flexure mobilization. Routine closure of the mesenteric defect was not performed in the initial surgery. Results: The four patients were treated by laparoscopic reintervention with closure of the mesenteric defect. In two of them, conversion to open surgery was necessary. One of the patients developed recurrent internal herniation after surgical reintervention with mesenteric closure of the defect. All patients were managed without need for bowel resection, and mortality rate was 0%. Conclusion Internal herniation after laparoscopic colorectal surgery is a highly morbid complication that requires prompt diagnosis and management and should be suspected in the early postoperative period. Additional studies with extended follow-up are required to establish recommendations regarding its prevention and management. (AU)
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Laparoscopia/efeitos adversos , Colectomia , Hérnia Interna/etiologia , Ileostomia , Conversão para Cirurgia Aberta , Hérnia Interna/diagnóstico por imagemRESUMO
ABSTRACT Pelvic exenteration has showed to be beneficial therapeutically and palliatively in locally advanced colorectal cancer. Reconstruction of urinary transit posterior to a cystectomy has always been challenging with many associated complications. We present a 58-year-old male with locally advanced rectal cancer in which a pelvic exenteration and a double-barreled wet colostomy (DBWC) was created for urinary reconstitution. We present the surgical technique of DBWC. DBWC is a good alternative to other urinary reconstructions because fecal and urinary derivation occurs in only one stoma, the stoma output is easier to manage, and fewer complications are seen compared to other urinary reconstructions. Long-term surveillance is mandatory in patients with a DBWC because there is an increased risk of neoplasm in the reservoir.
RESUMO A exenteração pélvica mostrou-se benéfica, tanto terapêutica quanto paliativamente, em casos de câncer colorretal localmente avançado. A reconstrução do trânsito urinário após uma cistectomia sempre foi desafiadora, com muitas complicações associadas. Os autores apresentam o caso de um homem de 58 anos de idade com câncer retal localmente avançado, submetido a uma exenteração pélvica e uma colostomia úmida em dupla-boca (CUDB) para reconstituição urinária. Os autores apresentam a técnica cirúrgica da CUDB, uma boa alternativa para outras reconstruções urinárias, já que a derivação fecal e urinária ocorre em apenas um estoma, a saída do estoma é mais fácil de gerenciar e o método apresenta menos complicações em comparação com outras reconstruções urinárias. A vigilância a longo prazo é obrigatória em pacientes com CUDB, pois há um risco aumentado de neoplasia no reservatório.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Exenteração Pélvica/estatística & dados numéricos , Colostomia/estatística & dados numéricos , Neoplasias Colorretais/cirurgiaRESUMO
BACKGROUND: The implementation of quality-of-care indicators aiming to improve colorectal cancer (CRC) outcomes has been previously described by Cancer Care Ontario. The aim of this study was to assess the quality-of-care indicators in CRC at a referral centre in a developing country and to determine whether improvement occurred over time. METHODS: We performed a retrospective study of our prospectively collected database of patients after CRC surgery from 2001 to 2016. We excluded patients who underwent local transanal excision, pelvic exenteration or palliative procedures. We evaluated trends over time using the Cochran-Armitage test for trend. RESULTS: A total of 343 patients underwent surgical resection of CRC over the study period. There was improvement of the following indicators over time: the proportion of patients detected by screening (p = 0.03), the proportion of patients with preoperative liver imaging (p = 0.001), the proportion of patients with stage II or III rectal cancer who received neoadjuvant chemotherapy (p = 0.03), the proportion of patients with pathology reports that indicated the number of lymph nodes examined and the number of positive nodes (p = 0.001), and the proportion of patients with pathology reports describing the details on margin status (p = 0.001). CONCLUSION: This study showed the feasibility of applying the Cancer Care Ontario indicators for evaluating outcomes in CRC treatment at a single centre in a developing country. Although there was an improvement of some of the quality-of-care indicators over time, policies and interventions must be implemented to improve the fulfillment of all indicators.
CONTEXTE: Action Cancer Ontario a déjà décrit l'application d'indicateurs de la qualité des soins dans le but d'améliorer l'issue du cancer colorectal (CCR). Le but de cette étude était d'évaluer les indicateurs de la qualité de soins pour le CCR dans un centre de référence d'un pays en voie de développement et de déterminer si des améliorations ont pu être observées avec le temps. MÉTHODES: Nous avons procédé à une étude rétrospective de notre base de données recueillies prospectivement auprès de patients ayant subi une chirurgie pour CCR entre 2001 et 2016. Nous avons exclu les patients qui ont subi une exérèse transanale locale, une exentération pelvienne ou des traitements palliatifs. Nous avons évalué les tendances au fil du temps à l'aide du test CochranArmitage pour dégager les tendances. RÉSULTATS: En tout, 343 patients ont subi une résection chirurgicale de CCR au cours de la période de l'étude. On a noté une amélioration des indicateurs suivants au fil du temps : proportion de patients ayant subi un dépistage (p = 0,03), proportion de patients ayant subi des épreuves d'imagerie hépatique préopératoires (p = 0,001), proportion de patients atteints d'un cancer rectal de stade II ou III ayant reçu une chimiothérapie néoadjuvante (p = 0,03), proportion de patients dont les rapports d'anatomopathologie indiquaient le nombre de ganglions lymphatiques examinés et le nombre de ganglions positifs (p = 0,001) et proportion de patients dont les rapports d'anatomopathologie décrivaient le statut des marges (p = 0,001). CONCLUSION: Cette étude a démontré l'applicabilité des indicateurs d'Action Cancer Ontario pour évaluer les résultats du traitement pour CCR dans un seul centre d'un pays en voie de développement. Même si certains des indicateurs de la qualité des soins se sont améliorés au fil du temps, il faut appliquer des politiques et des interventions pour améliorer tous les indicateurs.
Assuntos
Neoplasias Colorretais/cirurgia , Países em Desenvolvimento , Recidiva Local de Neoplasia/epidemiologia , Avaliação de Resultados em Cuidados de Saúde/métodos , Indicadores de Qualidade em Assistência à Saúde/organização & administração , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/mortalidade , Estudos de Viabilidade , Feminino , Seguimentos , Implementação de Plano de Saúde/organização & administração , Implementação de Plano de Saúde/estatística & dados numéricos , Humanos , Estimativa de Kaplan-Meier , Masculino , México , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/prevenção & controle , Avaliação de Programas e Projetos de Saúde , Indicadores de Qualidade em Assistência à Saúde/estatística & dados numéricos , Estudos Retrospectivos , Centros de Atenção Terciária/organização & administração , Centros de Atenção Terciária/estatística & dados numéricos , Adulto JovemRESUMO
PDLIM's protein family is involved in the rearrangement of the actin cytoskeleton. In the present study, we describe the localization of PDLIM1 in chicken photoreceptors. This study provides evidence that this protein is present at the cone pedicles, as well as in other synapses of the chicken retina. Here, we demonstrate the expression pattern of PDLIM1 through immunofluorescence staining, immunoblots, subcellular fractionation, and immunoprecipitation experiments. Also, we consider the possibility that PDLIM1 may be involved in the synaptic vesicle endocytosis and/or the presynaptic trafficking of synaptic vesicles back to the nonready releasable pool. This endocytotic/exocytotic coupling requires a tight link between exocytic vesicle fusion at defined release sites and endocytic retrieval of synaptic vesicle membranes. In turn, photoreceptor ribbon synaptic structure depends on the cytoskeleton arrangement, both at the active zone-related with exocytosis-as well as at the endocytic zone-periactive zone. To our knowledge, the PDLIM1 protein has not been observed in the pre synapses of the retina. Thus, the present study describes the expression and subcellular localization of PDLIM1 for the first time, as well as its modulation by visual environment in the chicken retina.
Assuntos
Proteínas Aviárias/metabolismo , Proteínas com Domínio LIM/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Sinapses/metabolismo , Animais , GalinhasRESUMO
Peripheral inflammation induces plastic changes in neurons and glia which are regulated by free calcium and calcium binding proteins (CaBP). One of the mechanisms associated with the regulation of intracellular calcium is linked to ERK (Extracellular Signal-Regulated Kinase) and its phosphorylated condition (pERK). ERK phosphorylation is important for intracellular signal transduction and participates in regulating neuroplasticity and inflammatory responses. The aim of this study is to analyse the expression of two CaBPs and pERK in astrocytes and neurons in rat trigeminal subnucleus caudalis (Vc) after experimental periapical inflammation on the left mandibular first molar. At seven days post-treatment, the periapical inflammatory stimulus induces an increase in pERK expression both in S100b positive astrocytes and Calbindin D28k positive neurons, in the ipsilateral Vc with respect to the contralateral side and control group. pERK was observed coexpressing with S100b in astrocytes and in fusiform Calbindin D28k neurons in lamina I. These results could indicate that neural plasticity and pain sensitization could be maintained by ERK activation in projection neurons at 7 days after the periapical inflammation.
La inflamación periférica induce cambios plásticos en las neuronas y en la glía, los cuales están regulados por el calcio libre y las proteínas fijadoras calcio (CaBP). Uno de los mecanismos asociados con la regulación del calcio intrace-lular está vinculado con la fosforilación de la pro teína quinasa ERK. Asimismo, ERK fosforilado es importante para la trans-ducción de señales intracelulares y participa en la regulación de la neuroplasticidad y las respuestas inflamatorias. El objetivo de este estudio es analizar la expresión de dos CaBPs y pERK en astrocitos y neuronas del subnúcleo caudal del trigémino (Vc) después de una inflamación periapical experimental en el primer molar inferior izquierdo en ratas. A los siete días posteriores al tratamiento, el estímulo inflamatorio periapical induce un aumento en la expresión de pERK, en el número de astrocitos positivos para la proteína marcadora astroglial S100b y en neuronas positivas para Calbindina D28k, en el Vc ipsilateral respecto del lado contralateral y el grupo de control. Además, se observó coexpresión de pERK tanto en astrocitos S100b positivos, como en neuronas fusiformes Calbindin D28k positivas, de la lámina I. Estas observaciones podrían indicar que la neuroplasticidad y la sensibilización al dolor podrían mantenerse mediante la activación de ERK en las neuronas de proyección a los 7 días de la inflamación periapical.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Inflamação , Plasticidade Neuronal , Núcleo Inferior Caudal do Nervo Trigêmeo/fisiopatologia , Animais , Astrócitos/metabolismo , Astrócitos/fisiologia , Neurônios/metabolismo , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Núcleos do TrigêmeoRESUMO
Peripheral inflammation induces plastic changes in neurons and glia which are regulated by free calcium and calcium binding proteins (CaBP). One of the mechanisms associated with the regulation of intracellular calcium is linked to ERK (Extracellular Signal-Regulated Kinase) and its phosphorylated condition (pERK). ERK phosphorylation is important for intracellular signal transduction and participates in regulating neuroplasticity and inflammatory responses. The aim of this study is to analyse the expression of two CaBPs and pERK in astrocytes and neurons in rat trigeminal subnucleus caudalis (Vc) after experimental periapical inflammation on the left mandibular first molar. At seven days post-treatment, the periapical inflammatory stimulus induces an increase in pERK expression both in S100b positive astrocytes and Calbindin D28k positive neurons, in the ipsilateral Vc with respect to the contralateral side and control group. pERK was observed coexpressing with S100b in astrocytes and in fusiform Calbindin D28k neurons in lamina I. These results could indicate that neural plasticity and pain sensitization could be maintained by ERK activation in projection neurons at 7 days after the periapical inflammation.
La inflamación periférica induce cambios plásticos en las neuronas y en la glía, los cuales están regulados por el calcio libre y las proteínas fijadoras calcio (CaBP). Uno de los mecanismos asociados con la regulación del calcio intrace-lular está vinculado con la fosforilación de la pro teína quinasa ERK. Asimismo, ERK fosforilado es importante para la trans-ducción de señales intracelulares y participa en la regulación de la neuroplasticidad y las respuestas inflamatorias. El objetivo de este estudio es analizar la expresión de dos CaBPs y pERK en astrocitos y neuronas del subnúcleo caudal del trigémino (Vc) después de una inflamación periapical experimental en el primer molar inferior izquierdo en ratas. A los siete días posteriores al tratamiento, el estímulo inflamatorio periapical induce un aumento en la expresión de pERK, en el número de astrocitos positivos para la proteína marcadora astroglial S100b y en neuronas positivas para Calbindina D28k, en el Vc ipsilateral respecto del lado contralateral y el grupo de control. Además, se observó coexpresión de pERK tanto en astrocitos S100b positivos, como en neuronas fusiformes Calbindin D28k positivas, de la lámina I. Estas observaciones podrían indicar que la neuroplasticidad y la sensibilización al dolor podrían mantenerse mediante la activación de ERK en las neuronas de proyección a los 7 días de la inflamación periapical.
Assuntos
Animais , Ratos , Núcleo Inferior Caudal do Nervo Trigêmeo/fisiopatologia , Proteínas de Ligação ao Cálcio/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Inflamação , Plasticidade Neuronal , Núcleos do Trigêmeo , Astrócitos/fisiologia , Astrócitos/metabolismo , Ratos Sprague-Dawley , Neurônios/fisiologia , Neurônios/metabolismoRESUMO
BACKGROUND: In colorectal cancer (CRC), regional lymphadenectomy provides prognostic information and guides management. The current consensus states that at least 12 lymph nodes (LN) should be evaluated. The aims of this study were to identify whether the number of LN is a predictor for survival and recurrence, and to reveal the role of LN ratio (LNR) and perineural invasion (PNI) in predicting prognosis after curative resection of CRC. METHODS: We included all patients who underwent surgery for CRC between 2000 and 2016 in an academic medical center in Mexico. The LNR cutoff value was 0.25. We analyzed two groups according to the number of LN retrieved: Group 1 (≥ 12 LN) and Group 2 (< 12 LN). RESULTS: We included 305 patients, 13.8% in Stage I, 45.6% in Stage II, and 40.6% in Stage III. The male: female ratio was 1.1. The mean age was 62.6 ± 14 years (range, 19-92). In 233 patients (76.4%), ≥ 12 LN were obtained. Recurrence rates in Groups 1 and 2 were 20.2% versus 26.4%, respectively (p = 0.16). PNI was present in 34 patients (13.2%). An LN harvest < 10 increased local and distant recurrences (p = 0.03). Stage III patients with an LNR ≥ 0.25 had higher overall recurrence rates (p = 0.012) and mortality (p = 0.029). In a multivariate Cox regression analysis, PNI-negative tumors were an independent prognostic factor for disease-free survival (p = 0.011, hazard ratio = 2.78, 95% confidence interval = 1.26-6.16). CONCLUSIONS: An LN retrieval < 10 increased local and distant recurrence rates. LNR was an independent prognostic factor for survival in Stage III tumors. PNI was the only significant independent prognostic factor affecting disease-free survival in our patients.
Assuntos
Neoplasias Colorretais/cirurgia , Excisão de Linfonodo/métodos , Linfonodos/patologia , Metástase Linfática/patologia , Centros Médicos Acadêmicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/patologia , Intervalo Livre de Doença , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Análise Multivariada , Invasividade Neoplásica , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Taxa de Sobrevida , Adulto JovemRESUMO
Members of the family of calcium binding proteins (CBPs) are involved in the buffering of calcium (Ca2+) by regulating how Ca2+ can operate within synapses or more globally in the entire cytoplasm and they are present in a particular arrangement in all types of retinal neurons. Calbindin D28k and calretinin belong to the family of CBPs and they are mainly co-expressed with other CBPs. Calbindin D28k is expressed in doubles cones, bipolar cells and in a subpopulation of amacrine and ganglion neurons. Calretinin is present in horizontal cells as well as in a subpopulation of amacrine and ganglion neurons. Both proteins fill the soma at the inner nuclear layer and the neuronal projections at the inner plexiform layer. Moreover, calbindin D28k and calretinin have been associated with neuronal plasticity in the central nervous system. During pre and early postnatal visual development, the visual system shows high responsiveness to environmental influences. In this work we observed modifications in the pattern of stratification of calbindin immunoreactive neurons, as well as in the total amount of calbindin through the early postnatal development. In order to test whether or not calbindin is involved in retinal plasticity we analyzed phosphorylated p38 MAPK expression, which showed a decrease in p-p38 MAPK, concomitant to the observed decrease of calbindin D28k. Results showed in this study suggest that calbindin is a molecule related with neuroplasticity, and we suggest that calbindin D28k has significant roles in neuroplastic changes in the retina, when retinas are stimulated with different light conditions.
Assuntos
Calbindina 1/fisiologia , Calbindina 2/fisiologia , Luz , Plasticidade Neuronal/fisiologia , Estimulação Luminosa/métodos , Retina/crescimento & desenvolvimento , Retina/metabolismo , Animais , Animais Recém-Nascidos , Calbindina 1/biossíntese , Calbindina 2/biossíntese , Galinhas , Feminino , Rede Nervosa/química , Rede Nervosa/crescimento & desenvolvimento , Rede Nervosa/metabolismo , Gravidez , Retina/fisiologiaRESUMO
Sensory information on facial structures, including teeth pulp, periodontium, and gingiva, is relayed in the trigeminal complex. Tooth pulp inflammation constitutes a common clinical problem, and this peripheral injury can induce neuroplastic changes in trigeminal nociceptive neurons. There is considerable evidence that the trigeminal subnucleus caudalis (Vc) is the principal relay for trigeminal nociceptive information as well as modulation of the painful stimuli. Glutamatergic primary afferents innervating the tooth pulp project to the most superficial laminae of the Vc. N-methyl-D-aspartate receptor stimulation leads to the activation of the enzyme nitric oxide synthase (NOS), which synthesizes the free radical nitric oxide (NO). This enzyme is expressed mainly in lamina II interneurons, and in a small number of cells in lamina I as well as in deep laminae projection neurons of Vc. In the present study, we analyzed the temporal changes in neuronal NOS (nNOS) in Vc local circuitries after unilateral intermediate molar pulp injury. Our results demonstrate that a peripheral dental pulp injury leads to neuroplastic changes in the relative amount and activity of nNOS enzyme. Moreover, after a period of time, the nitrergic system shifts to the initial values, independently of the persistence of inflammation in the pulp tissues.
Assuntos
Polpa Dentária/inervação , NADP/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Nociceptores/enzimologia , Núcleos do Trigêmeo/enzimologia , Vias Aferentes/enzimologia , Animais , Polpa Dentária/lesões , Feminino , Plasticidade Neuronal/fisiologia , Neurônios/enzimologia , Ratos , Ratos WistarRESUMO
Acute and long-term complications can occur in patients receiving radiation therapy. It has been suggested that cytoprotection might decrease the incidence and severity of therapy-related toxicity in these patients. Developing cerebellum is highly radiosensitive and for that reason it is a useful structure to test potential neuroprotective substances to prevent radiation induced abnormalities. Recent studies have shown that estrogen can rapidly modulate intracellular signalling pathways involved in cell survival. Thus, it has been demonstrated that estrogens mediate neuroprotection by promoting growth, cell survival and by preventing axonal pruning. The aim of this work was to evaluate the effect of the treatment with 17-ß-estradiol on the motor, structural and biochemical changes induced by neonatal ionizing radiation exposure, and to investigate the participation of nitric oxide and protein kinase C, two important intracellular messengers involved in neuronal activity. Our results show that perinatal chronic 17-ß-estradiol treatment partially protects against radiation-induced cerebellar disorganization and motor abnormalities. PKC and NOS activities could be implicated in its neuroprotective mechanisms. These data provide new evidence about the mechanisms underlying estrogen neuroprotection, which could have therapeutic relevance for patients treated with radiotherapy.
Assuntos
Dano Encefálico Crônico/tratamento farmacológico , Doenças Cerebelares/tratamento farmacológico , Estradiol/farmacologia , Fármacos Neuroprotetores/farmacologia , Lesões Experimentais por Radiação/tratamento farmacológico , Lesões Experimentais por Radiação/metabolismo , Animais , Animais Recém-Nascidos , Dano Encefálico Crônico/etiologia , Dano Encefálico Crônico/prevenção & controle , Doenças Cerebelares/etiologia , Doenças Cerebelares/prevenção & controle , Feminino , Raios gama , Masculino , Lesões Experimentais por Radiação/etiologia , Ratos , Ratos WistarRESUMO
Pain in humans constitutes a complex perception that involves peripheral tissues, nerves and the central nervous system. The glia is thought to be involved in the propagation and modulation of painful stimuli, as well as for the neurotransmission and plastic changes. In this work, an intermediate inflammatory nociceptive stimulus was generated after the exposure of the pulp in the left mandibular first molar. We analyzed the relationship between this tooth injury and the S100B expression in the trigeminal subnucleus caudalis. A significant difference of S100B immunoreactivity between the ipsilateral and the contralateral side could be observed at the 4th postoperative day. Besides, S100B positive-astrocytes located in the ipsilateral side showed an increase in their arborization, but not in the level of expression of the S100B protein. Our findings suggest that a unilateral peripheral nociceptive stimulus produces modifications in S100B positive-astrocytes in both sides of the trigeminal subnucleus caudalis.
Assuntos
Astrócitos/fisiologia , Polpa Dentária/lesões , Fatores de Crescimento Neural/metabolismo , Dor/fisiopatologia , Proteínas S100/metabolismo , Traumatismos Dentários/fisiopatologia , Núcleos do Trigêmeo/fisiopatologia , Análise de Variância , Animais , Astrócitos/patologia , Contagem de Células , Feminino , Lateralidade Funcional , Imuno-Histoquímica , Dor/etiologia , Dor/patologia , Fotomicrografia , Ratos , Ratos Wistar , Subunidade beta da Proteína Ligante de Cálcio S100 , Fatores de Tempo , Traumatismos Dentários/patologia , Núcleos do Trigêmeo/patologiaRESUMO
Sleep apnea (SA) can be effectively managed in humans but it is recognized that when left untreated, SA causes long-lasting changes in neuronal circuitry in the brain. Recent neuroimaging studies gave suggested that these neuronal changes are also present even in patients successfully treated for the acute effects of SA. The cellular mechanisms that account for these changes are not certain but animal models of intermittent hypoxia (IH) during sleep have shown neuronal death and impairment in learning and memory. Reactive gliosis has a drastic effect on neuronal survival and circuitry and in this study we examined the neuro-glial response in brain areas affected by SA. Glial and neuronal alterations were analyzed after 1, 3, 5 and 10 days of exposure to IH (8 h/day during the sleep phase, cycles of 6 min each, 10-21% O2) and observed significant astroglial hyperplasia and hypertrophy in parietal brain cortex and hippocampus by studying gliofibrillary acidic protein, Vimentin, S100B and proliferating cell nuclear antigen expression. In addition, altered morphology, reduced dendrite branching and caspase activation were observed in the CA-1 hippocampal and cortical (layers IV-V) pyramidal neurons at short exposure times (1-3 days). Surprisingly, longer exposure to IH reduced the neuronal death rate and increased neuronal branching in the presence of persistent reactive gliosis. Up-regulation of hypoxia inducible factor 1 alpha (HIF-1alpha) and mdr-1, a HIF-1alpha target gene, were observed and increased expression of receptor for advanced end glycated products and its binding partner S100B were also noted. Our results show that a low number of hypoxic cycles induce reactive gliosis and neuronal death whereas continuous exposure to IH cycles reduced the rate of neuronal death and induced neuronal branching on surviving neurons. We hypothesize that HIF-1alpha and S100B glial factor may improve neuronal survival under hypoxic conditions and propose that the death/survival/re-growth process observed here may underlie brain circuitry changes in humans with SA.
Assuntos
Encéfalo , Gliose/etiologia , Neuroglia/patologia , Neurônios/patologia , Síndromes da Apneia do Sono/complicações , Síndromes da Apneia do Sono/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Caspases/metabolismo , Morte Celular/fisiologia , Modelos Animais de Doenças , Masculino , Proteínas do Tecido Nervoso/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Wistar , Síndromes da Apneia do Sono/metabolismo , Fatores de TempoRESUMO
Neonatal ionizing radiation exposure has been shown to induce a cerebellar cytoarchitecture disarrangement. Since cerebellar abnormalities have been linked to an impairment of behavioral functions, the aim of the present work was to investigate whether exposure of developing rats to ionizing radiations can produce behavioral deficits in the adult. Male Wistar rats were X-irradiated with 5Gy within 48h after birth and were tested in a radial maze and in an open field at 30 and 90 days post irradiation. Irradiated rats showed significative changes in spatial, exploratory, and procedural parameters in the radial maze, as well as a significative decrease in anxiety-like behavior, assessed in the open field. These results suggest that ionizing radiations can induce long-lasting spatial memory and anxiety-related changes. A relationship with radiation-induced cerebellar cytoarchitecture abnormalities supports the hypothesis that cerebellar integrity seems to be critical to achieve spatial performance and emotional behavior establishment.
Assuntos
Ansiedade/psicologia , Comportamento Animal/efeitos da radiação , Comportamento Exploratório/efeitos da radiação , Aprendizagem em Labirinto/efeitos da radiação , Memória/efeitos da radiação , Lesões Experimentais por Radiação/psicologia , Animais , Animais Recém-Nascidos , Comportamento Animal/fisiologia , Córtex Cerebelar/patologia , Córtex Cerebelar/efeitos da radiação , Comportamento Exploratório/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/fisiopatologia , Ratos , Ratos WistarRESUMO
Nitric oxide (NO) has been involved in many pathophysiological brain processes. However, the exact role of NO in the cognitive deficit associated to chronic stress exposure has not been elucidated. In this study, we investigated the participation of hippocampal NO production and their regulation by protein kinase C (PKC) in the memory impairment induced in mice subjected to chronic mild stress model (CMS). CMS mice showed a poor learning performance in both open field and passive avoidance inhibitory task respect to control mice. Histological studies showed a morphological alteration in the hippocampus of CMS mice. On the other hand, chronic stress induced a diminished NO production by neuronal nitric oxide synthase (nNOS) correlated with an increment in gamma and zeta PKC isoenzymes. Partial restoration of nNOS activity was obtained after PKC activity blockade. NO production by inducible nitric oxide synthase isoform was not detected. The magnitude of oxidative stress, evaluated by reactive oxygen species production, after excitotoxic levels of NMDA was increased in hippocampus of CMS mice. Moreover, ROS formation was higher in the presence of nNOS inhibitor in both control and CMS mice. Finally, treatment of mice with nNOS inhibitors results in behavioural alterations similar to those observed in CMS animals. These findings suggest a novel role for nNOS showing protective activity against insults that trigger tissue toxicity leading to memory impairments.
Assuntos
Hipocampo/enzimologia , Deficiências da Aprendizagem/enzimologia , Deficiências da Aprendizagem/psicologia , Transtornos da Memória/enzimologia , Transtornos da Memória/psicologia , Óxido Nítrico Sintase Tipo I/fisiologia , Estresse Psicológico/enzimologia , Estresse Psicológico/psicologia , Animais , Aprendizagem da Esquiva/fisiologia , Western Blotting , Doença Crônica , Feminino , Imuno-Histoquímica , Isoenzimas/metabolismo , Deficiências da Aprendizagem/etiologia , Transtornos da Memória/etiologia , Camundongos , Camundongos Endogâmicos BALB C , N-Metilaspartato/farmacologia , Plasticidade Neuronal/fisiologia , Óxido Nítrico/biossíntese , Óxido Nítrico/fisiologia , Óxido Nítrico Sintase Tipo I/metabolismo , Proteína Quinase C/metabolismo , Proteína Quinase C-alfa/metabolismo , Proteína Quinase C-épsilon/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/fisiologia , Estresse Psicológico/complicaçõesRESUMO
Sensory experience is critical for the formation of neuronal circuits and it is well known that neuronal activity plays a crucial role in the formation and maintenance of synapses. In the vertebrate retina, exposure to different environmental conditions results in structural, physiological, neurochemical and pharmacological changes. Serotoninergic (5HT) amacrine cells of the chicken retina are bistratified interneurons whose primary dendrites descend through the inner nuclear layer (INL) to branch in the inner plexiform layer (IPL) forming two plexi, an outer network, localized to sublamina 1, and an inner network, localized to sublamina 4 and 5 of the IPL. Their development is temporally correlated with the establishment of synapses in the retina and with the emergence of the typical adult electroretinogram. It is unknown, however, which role these cells play in processing visual information and whether visual deprivation modifies their phenotype. Here, we show that, in the chicken, red-light rearing from hatching to postnatal day 12 significantly alters the stratification pattern of 5HT amacrine cells, inhibiting their age-dependent pruning measured with morphometric and densitometric procedures; as well as increasing serotonin immunoreactivity measured as relative optical density. This change in dendritic arborization, accompanied by an increase in serotonin concentration in dark adapted conditions, may decrease visual threshold, thus increasing visual sensitivity.
Assuntos
Células Amácrinas/fisiologia , Escuridão , Plasticidade Neuronal/fisiologia , Retina/citologia , Retina/metabolismo , Serotonina/metabolismo , Fatores Etários , Células Amácrinas/efeitos da radiação , Animais , Animais Recém-Nascidos , Embrião de Galinha , Galinhas , Diagnóstico por Imagem , Imuno-Histoquímica/métodos , Retina/crescimento & desenvolvimento , Retina/efeitos da radiaçãoRESUMO
In this study, we show that one single dose of gamma-irradiation at birth induces an inhibition of the cerebellar calcium dependent nitric oxide synthase (NOS) activity, probably correlated to the motor abnormalities and the disarrangement in the cerebellar cytoarchitecture observed in adult rats. This decrease in calcium dependent NOS activity could be associated with an increased protein kinase C (PKC) activity. PKC inhibition partially restores calcium dependent NOS activity, indicating that PKC activity could be negatively modulating the catalytic activity of calcium dependent NOS. These findings suggest that a decrease in nitric oxide (NO) production and the related increase in PKC activity could be intracellular events that participate in the onset of motor and cerebellar abnormalities induced by postnatal gamma-irradiation at early stages of life.
Assuntos
Cerebelo/enzimologia , Cerebelo/efeitos da radiação , Raios gama , Óxido Nítrico Sintase/efeitos da radiação , Proteína Quinase C/efeitos da radiação , Lesões Experimentais por Radiação/enzimologia , Análise de Variância , Animais , Animais Recém-Nascidos , Calbindinas , Cálcio/metabolismo , Cerebelo/patologia , Feminino , Marcha/efeitos da radiação , Masculino , Neurônios/enzimologia , Neurônios/patologia , Neurônios/efeitos da radiação , Ratos , Ratos Wistar , Proteína G de Ligação ao Cálcio S100/efeitos da radiação , Transdução de Sinais/efeitos da radiação , Fatores de TempoRESUMO
El asma es una enfermedad muy común, pero su prevalencia varía grandemente de región a región incluso en un mismo país. En el noroeste de México no se han realizado estudios epidemiológicos sobre esta enfermedad. En este trabajo aplicamos un cuestionario estandarizado (ISAAC) a los padres de niños que asistían a 8 escuelas primarias de la ciudad mexicana de Hermosillo, Sonora. De 3000 cuestionarios enviados se contestaron aceptablemente 1489 (49 por ciento). Los niños fueron de ambos sexos, con edad de 9.1 ñ 1.8 años (x ñ DE). De esta población, 74 (10.4 por ciento) de 713 niños y 67 (8.6 por ciento) de 776 niñas tuvieron una respuesta afirmativa a la pregunta "¿Alguna vez ha tenido asma?", por lo que concluimos que la prevalencia global de asma en la muestra estudiada fue de 9.5 por ciento, cifra que resulta intermedia entre las informadas por otros estudios hechos en México.