RESUMEN
PURPOSE: Stoma site marking is an important preoperative intervention for preventing various stoma-associated complications. In our institution, standardized stoma site marking is routinely performed before rectal cancer surgery with stoma creation, and various stoma-associated factors are recorded in the ostomy-record template. The present study investigated risk factors for stoma leakage. METHODS: Our stoma site marking is standardized so that it can be performed by non-stoma specialists. To identify risk factors of stoma leakage at 3 months after surgery, various preoperative factors associated with stoma site marking in our ostomy-record template were retrospectively analyzed in 519 patients who underwent rectal cancer surgery with stoma creation from 2015 to 2020. RESULTS: Stoma leakage was seen in 35 of the 519 patients (6.7%). The distance between the stoma site marking and the umbilicus was less than 60 mm in 27 of the 35 patients (77%) who experienced stoma leakage, so a distance of less than 60 mm was identified as an independent risk factor for stoma leakage. Aside from preoperative factors, stoma leakage was also caused by postoperative skin wrinkles or surgical scars near the stoma site in 8 of 35 patients (23%). CONCLUSION: Preoperative standardized stoma site marking is necessary to achieve reliable marking that is easy to perform. To reduce the risk of stoma leakage, a distance of 60 mm or more between the stoma site marking and the umbilicus is ideal, and surgeons need to contrive ways to keep surgical scars away from the stoma site.
Asunto(s)
Laparoscopía , Neoplasias del Recto , Procedimientos Quirúrgicos Robotizados , Estomas Quirúrgicos , Humanos , Estudios Retrospectivos , Cicatriz , Estomas Quirúrgicos/efectos adversos , Laparoscopía/efectos adversos , Neoplasias del Recto/cirugía , Estándares de ReferenciaRESUMEN
BACKGROUND: Immune checkpoint inhibitors, such as antibody against programmed cell death protein (PD-1), have demonstrated antitumour effects in patients with malignancies, including oesophageal cancer. A lymphocytic reaction observed by pathological examination is a manifestation of the host immune response to tumour cells. It was hypothesized that a stronger lymphocytic reaction to tumours might be associated with favourable prognosis in oesophageal cancer. METHODS: Using a database of resected oesophageal cancers, four morphological components of lymphocytic reactions (peritumoral, intranest, lymphoid and stromal) to tumours were evaluated in relation to clinical outcome, PD-1 expression by immunohistochemistry and total lymphocyte count in blood. RESULTS: Resected oesophageal cancer specimens from 436 patients were included in the study. Among the four morphological components, only peritumoral reaction was associated with patient prognosis (multivariable P for trend <0·001); patients with a higher peritumoral reaction had significantly longer overall survival than those with a lower reaction (multivariable hazard ratio 0·48, 95 per cent c.i. 0·34 to 0·67). The prognostic effect of peritumoral reaction was not significantly modified by other clinical variables (all P for interaction >0·050). Peritumoral reaction was associated with total lymphocyte count in the blood (P < 0·001), supporting the relationship between local immune response and systemic immune competence. In addition, higher morphological peritumoral reaction was associated with high PD-1 expression on lymphocytes in tumours (P = 0·034). CONCLUSION: These findings should help to improve risk-adapted therapeutic strategies and help stratify patients in the future clinical setting of immunotherapy for oesophageal cancer.
ANTECEDENTES: Los inhibidores de los puntos de control inmunitario (checkpoints) (p.ej. los anticuerpos anti-PD-1) han demostrado efectos antitumorales en pacientes con tumores malignos, incluido el cáncer de esófago. La reacción linfocítica detectada en estudios anatomopatológicos es una manifestación de la respuesta inmune del huésped a las células tumorales. Se estableció la hipótesis de que una mayor reacción linfocítica a los tumores podría asociarse con un mejor pronóstico en el cáncer de esófago. MÉTODOS: Usando una base de datos de 436 cánceres de esófago resecados, se evaluaron cuatro componentes morfológicos (peritumoral, intra-epitelial, linfoide y estromal) de las reacciones linfocíticas a tumores en relación con los resultados clínicos, la expresión inmunohistoquímica de PD-1 y el recuento total de linfocitos en sangre. RESULTADOS: De los cuatro componentes, solamente la reacción peritumoral se asoció con el pronóstico del paciente (P multivariable para tendencia < 0,001): los pacientes con mayor reacción peritumoral presentaron una supervivencia global significativamente más prolongada que aquellos pacientes con menor reacción peritumoral (cociente de riesgos instantáneos multivariable, hazard ratio, HR: 0,48; i.c. del 95%: 0,34 -0,67; P <0,001). El efecto pronóstico de la reacción peritumoral no se modificó significativamente por otras variables clínicas (todas las P para la interacción > 0,05). La reacción peritumoral se asoció con el recuento total de linfocitos en la sangre (P < 0,001), lo que respalda la relación entre la respuesta inmune local y la competencia inmune sistémica. Además, una elevada reacción morfológica peritumoral se asoció con una alta expresión de PD-1 en linfocitos tumorales (P = 0,034). CONCLUSIÓN: Estos hallazgos deberían ayudar a mejorar las estrategias terapéuticas adaptadas al riesgo y contribuir a estratificar a los pacientes en el entorno clínico futuro de la inmunoterapia para los pacientes con cáncer de esófago.
Asunto(s)
Neoplasias Esofágicas/cirugía , Linfocitos/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Anciano , Neoplasias Esofágicas/inmunología , Neoplasias Esofágicas/mortalidad , Femenino , Humanos , Recuento de Linfocitos , Linfocitos/metabolismo , Masculino , Pronóstico , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
Whereas smoking constitutes a significant risk factor for postesophagectomy morbidity, there is no reliable method to assess the smoking status of patients prior to the procedure. Since exhaled carbon monoxide (CO) is an indicator of recent smoking, this paper hypothesizes that this is a useful parameter in assessing current smoking status and may help predict morbidity following esophagectomy. Sixty-nine patients, who had undergone elective three-incision esophagectomy with two- or three-field lymphadenectomy for esophageal cancer, were prospectively studied between February 2015 and September 2017. At surgical admission, they were asked about their smoking history, their exhaled CO levels were evaluated, and they were grouped into three based on their CO levels. These were 0 parts per million (ppm), >0 and <7 ppm, and ≥7 ppm. Their postoperative morbidity was also assessed. Approximately 13.5% of the patients showed high levels of exhaled CO ≥ 7 ppm, despite preoperatively reporting smoking cessation for over a month. Morbidities of the Clavien-Dindo classification (CDc) ≥ II increased as exhaled CO levels increased and severe morbidity of CDc ≥ IIIb frequently was observed in patients with exhaled CO levels ≥7 ppm. The logistic regression analysis showed that exhaled CO level ≥7 ppm was an independent risk factor for severe postesophagectomy morbidity. Overall, the results of this study suggest that exhaled CO levels may be useful in estimating current smoking status and that it may also help give an estimation of the risk of postesophagectomy morbidity.
Asunto(s)
Pruebas Respiratorias/métodos , Monóxido de Carbono/análisis , Esofagectomía/efectos adversos , Complicaciones Posoperatorias/etiología , Cuidados Preoperatorios/métodos , Anciano , Anciano de 80 o más Años , Neoplasias Esofágicas/cirugía , Espiración , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Factores de Riesgo , Fumar/efectos adversosAsunto(s)
Colectomía/métodos , Laparoscopía/métodos , Agujas , Neoplasias del Colon Sigmoide/cirugía , HumanosRESUMEN
BACKGROUND: F-box and WD repeat domain-containing 7 (FBXW7) is a cell cycle regulatory gene whose protein product ubiquitinates positive cell cycle regulators such as c-Myc, cyclin E, and c-Jun, thereby acting as a tumour-suppressor gene. This study focused on microRNA-223 (miR-223), which is a candidate regulator of FBXW7 mRNA. The aim of this study was to clarify the clinical significance of miR-223 and FBXW7 in oesophageal squamous cell carcinoma (ESCC) patients, and to elucidate the mechanism by which FBXW7 is regulated by miR-223. METHODS: The expression levels of miR-223 and the expression of FBXW7 protein was examined using 109 resected specimens to determine the clinicopathological significance. We also investigated the role of miR-223 in the regulation of FBXW7 expression in ESCC cell lines in an in vitro analysis. RESULTS: We found that miR-223 expression was significantly higher in cancerous tissues than in the corresponding normal tissues. There was a significant inverse relationship between the expression levels of miR-223 and FBXW7 protein. Moreover, patients with high miR-223 expression demonstrated a significantly poorer prognosis than those with low expression. On the basis of a series of gain-of-function and loss-of-function studies in vitro, we identified FBXW7 as a functional downstream target of miR-223. CONCLUSION: Our present study indicates that high expression of miR-223 had a significant adverse impact on the survival of ESCC patients through repression of the function of FBXW7.
Asunto(s)
Carcinoma de Células Escamosas/enzimología , Proteínas de Ciclo Celular/metabolismo , Neoplasias Esofágicas/enzimología , Proteínas F-Box/metabolismo , MicroARNs/fisiología , Ubiquitina-Proteína Ligasas/metabolismo , Anciano , Secuencia de Bases , Western Blotting , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Cartilla de ADN , Neoplasias Esofágicas/patología , Proteína 7 que Contiene Repeticiones F-Box-WD , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Pronóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Of 34 infants less than 1 year of age with acute leukemia, 20 had an 11q23 translocation (group I), 8 had t(4;11), 5 had t(11;19), 3 had t(1;11), 2 had t(10;11), 1 had t(9;11), and the other had an 11q+ chromosome. Nine had other chromosome changes (group II), including t(1;19), t(8;14), 5q- chromosome, or +8 in one each, and a translocation involving 7p22 in two. The other five had normal diploidy in their leukemic cells (group III). Thus, the 11q23 translocation was seen in 50% of the leukemic infants, and in as high as 75% of the infants less than 6 months old. While the 7p22 translocations were both seen in those less than 6 months, the four chromosome abnormalities without 11q23 translocation mentioned above and normal diploidy were found only in those 6 months old or more. The group I patients had higher leukocyte counts than the group II (p less than 0.05) or group III (p less than 0.01) patients. Of the 20 group I patients, 16 were classified as having ALL, and 4 were classified as having ANLL. Eleven of 15 ALLs with the 11q23 translocation showed an Ia+, CALLA-, and B4+ (8 of 9 examined) immunophenotype. Coexpression of lymphoid and myeloid Ags was seen in four ALLs and two ANLLs with the 11q23 translocation. The survival of group II patients (median, 9 months) was significantly shorter than that of group I (median, 19 months) (p less than 0.05) or group III (median, 44 months) (p less than 0.01) patients; the difference in the survival between group I and group III patients was not significant. It is noteworthy that 5 of the 20 group I patients have survived 20 months or more without relapsing.
Asunto(s)
Aberraciones Cromosómicas/genética , Cromosomas Humanos Par 11 , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Translocación Genética , Antígenos de Diferenciación/análisis , Trastornos de los Cromosomas , Humanos , Lactante , Recién Nacido , Leucemia-Linfoma Linfoblástico de Células Precursoras/clasificación , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunologíaRESUMEN
In a chromosome study of childhood lymphoblastic lymphoma, we found a novel translocation, t(9;17)(q34;q23), in three patients. They presented with mediastinal mass and no bone marrow involvement. Despite intensive chemotherapy, one patient had no response, the other two relapsed after a brief remission, and all progressed to death. The 9;17 translocation may have a clinical implication for lymphoblastic lymphoma patients in predicting a poor prognosis. Since, in addition to our cases, involvement of the 9q34 breakpoint, together with 2q33, 14q11, or 7q34, has been reported in the literature in four lymphoblastic lymphoma patients, a gene located in 9q34 and referred to as tcl-3 may participate in the genesis of the T cell malignancies carrying these translocations. Furthermore, as is the case in other lymphomas, the reciprocal breakpoint, 17q23, might be the site of a yet unidentified T cell function gene.
Asunto(s)
Cromosomas Humanos Par 17 , Cromosomas Humanos Par 9 , Leucemia Linfocítica Crónica de Células B/genética , Translocación Genética , Adolescente , Adulto , Antígenos de Diferenciación de Linfocitos T/análisis , Niño , Preescolar , Bandeo Cromosómico , Femenino , Humanos , Leucemia Linfocítica Crónica de Células B/clasificación , Leucemia Linfocítica Crónica de Células B/patología , Masculino , Fenotipo , Linfocitos T/inmunología , Linfocitos T/patologíaRESUMEN
Thirteen patients with sustained ventricular tachycardia (VT) were studied to elucidate predisposing factors for the development of constant and progressive fusion by rapid atrial pacing. All patients demonstrated transient entrainment by rapid ventricular pacing during VT. Constant and progressive fusion were observed in 7 patients (positive group) during rapid atrial pacing, but not in 6 (negative group). In the positive group, VT was induced by atrial pacing in 2 patients. The demonstration of constant and progressive fusion by atrial pacing was not dependent on QRS morphology or ventriculoatrial conduction during VT. VT cycle length in the positive group (363 +/- 59 ms) was longer than in the negative group (297 +/- 31 ms; p = 0.033). The maximal atrial pacing rate producing 1:1 atrioventricular (AV) conduction in the positive group was 171 +/- 18 beats/min compared with 125 +/- 22 beats/min in the negative group (p = 0.002). There were distinct differences between the positive and negative groups in the ratio of VT cycle length to minimal atrial cycle length causing 1:1 AV conduction (1.02 +/- 0.12 vs 0.61 +/- 0.12; p = 0.0001). It is concluded that AV conduction, VT cycle length and especially their ratio are important factors for the development of transient entrainment by rapid atrial pacing during VT. Therefore, atrial pacing can be used as an easy and useful method to examine transient entrainment during VT.
Asunto(s)
Estimulación Cardíaca Artificial , Taquicardia Ventricular/fisiopatología , Adulto , Anciano , Estimulación Cardíaca Artificial/métodos , Electrocardiografía , Electrofisiología , Femenino , Atrios Cardíacos/fisiopatología , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
We studied the effects of adrenoceptor antagonists and imidazoline derivatives on endogenous adrenaline-induced inhibition of insulin release in anesthetized rats. The intracerebroventricular injection of neostigmine increased plasma levels of catecholamines and glucose but not insulin. Pretreatment with an i.p. injection with phentolamine caused a dose-dependent increase in insulin secretion. When atropine was coadministered with phentolamine, the phentolamine-induced increase in insulin secretion was inhibited. Neither phentolamine nor atropine affected plasma levels of catecholamine. Yohimbine and idazoxan, which are alpha 2-adrenoceptor antagonists, and tolazoline, a non-selective alpha-adrenoceptor antagonist, also reversed adrenaline-induced inhibition of insulin secretion. Phenoxybenzamine, prazosin, propranolol, and antazoline, an imidazoline without alpha 2-adrenoceptor activity, did not affect insulin levels. When agents were preinjected i.p. in rats that were given saline into the third cerebral ventricle, phentolamine and antazoline, but not yohimbine and idazoxan, increased plasma levels of insulin. The results suggest that the inhibition of insulin release induced by adrenaline was reversed by antagonism of alpha 2-adrenoceptors. Phentolamine and antazoline, both of which are imidazoline derivatives, induced insulin secretion independently of the adrenoceptors only under the resting conditions.
Asunto(s)
Agonistas de Receptores Adrenérgicos alfa 2 , Antagonistas de Receptores Adrenérgicos alfa 2 , Agonistas alfa-Adrenérgicos/farmacología , Epinefrina/farmacología , Imidazoles/farmacología , Insulina/metabolismo , Antagonistas Adrenérgicos alfa/farmacología , Animales , Atropina/farmacología , Glucemia/metabolismo , Estimulantes del Sistema Nervioso Central/farmacología , Inyecciones Intraventriculares , Insulina/sangre , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Parasimpatolíticos/farmacología , Fentolamina/farmacología , Ratas , Ratas Wistar , Cloruro de SodioRESUMEN
This study has attempted to assess the importance of mesenchymal cells, fibroblasts, cementoblasts, and mononuclear phagocytes (i.e., macrophages) in physiological root resorption of feline deciduous teeth. Deciduous incisors of three- to six-month-old kittens undergoing root resorption were investigated by means of electron microscopy. In an early phase of root resorption, the resorption organ consisted of many fibroblasts and relatively few macrophages and odontoclasts, the last with a wide, clear zone and narrow, immature, ruffled border. In the active phase of root resorption, the resorption organ contained many odontoclasts with a well-developed ruffled border and a reduced clear zone, cementoblasts, fibroblasts, macrophages, neutrophils, and many blood vessels. Cementoblasts were present usually on the resorbing dentin surface adjacent to odontoclasts and, in many cases, these cells communicated with each other via gap junctions. Cementoblasts frequently extended broad cell processes with secretion granules and with phagosomes containing collagen fibrils into the dentinal tubules exposed to resorption lacunae. Some macrophages exhibiting a clear zone-like structure also appeared on resorbing dentin surfaces. In the resting phase of root resorption, the dentin surface was covered mostly with cementoblasts resembling bone lining cells. There was an occasional macrophage, but no odontoclasts were observed during this phase. During removal of the periodontal ligament concomitant with root resorption, many fibroblasts phagocytosed mature collagen fibrils, as well as amorphous fluffy material. These results suggest that these mesenchymal cells, as well as odontoclasts, are essential for the cellular removal of dental hard and soft tissues during shedding of feline deciduous teeth.
Asunto(s)
Resorción Radicular , Exfoliación Dental , Diente Primario/fisiología , Animales , Gatos , Cemento Dental/fisiología , Macrófagos/fisiología , Microscopía Electrónica , Osteoclastos/fisiología , Diente Primario/ultraestructuraRESUMEN
Three new variants of pyrimidine 5'-nucleotidase (P5N) found in Japan were studied. They are characterized by slow electrophoretic mobility and a high Michaelis constant for cytidine 5'-monophosphate as has been described in previously reported cases, but are unique with respect to the thermostability test and in pH optima. P5N Kumamoto was thermostable and showed a markedly basic shift in the pH optimum. P5N Nagano was thermolabile and had a normal pH optimum. P5N Kurume was thermostable and showed a basic shift in the pH optimum. These data suggest that these variants have structural gene mutations and that they are clearly distinguished from previously reported cases.
Asunto(s)
Anemia Hemolítica/genética , Nucleotidasas/deficiencia , 5'-Nucleotidasa , Adolescente , Adulto , Anemia Hemolítica/enzimología , Anemia Hemolítica/etiología , Niño , Estabilidad de Medicamentos , Electroforesis en Acetato de Celulosa , Femenino , Calor , Humanos , Concentración de Iones de Hidrógeno , Cinética , Masculino , Nucleotidasas/sangre , LinajeRESUMEN
We investigated the relationship between histamine and muscarinic cholinergic neurons in central nervous system (CNS)-mediated glucose regulation in anesthetized fed rats. The injection of pyrilamine (5 x 10(-7) mol) into the third cerebral ventricle suppressed the hyperglycemia induced by intraventricular injection of histamine (5 x 10(-7) mol). Ranitidine (5 x 10(-7) mol), however, did not suppress this hyperglycemia. The injection of atropine (5 x 10(-9)-5 x 10(-7) mol) into the third cerebral ventricle suppressed the histamine-induced hyperglycemia in a dose-dependent manner. These findings suggest that histamine induction of CNS-mediated hyperglycemia involves neuronal transmission not only via H1 receptors but also, at least in part, by muscarinic cholinergic neurons.
Asunto(s)
Atropina/farmacología , Encéfalo/efectos de los fármacos , Antagonistas de los Receptores Histamínicos/farmacología , Histamina/farmacología , Hiperglucemia/inducido químicamente , Animales , Sistema Nervioso Central/fisiopatología , Relación Dosis-Respuesta a Droga , Histamina/administración & dosificación , Hiperglucemia/fisiopatología , Inyecciones Intraventriculares , Masculino , Neurotransmisores/fisiología , Pirilamina/administración & dosificación , Pirilamina/farmacología , Ranitidina/administración & dosificación , Ranitidina/farmacología , Ratas , Ratas Wistar , Receptores Muscarínicos/fisiologíaRESUMEN
We previously reported that when neostigmine, an inhibitor of acetylcholine esterase, was injected into the third cerebral ventricle, the concentration of hepatic venous plasma glucose was increased via central muscarinic receptors in anesthetized rats. To determine whether brain histamine receptors are involved in cholinergic system transmission with regard to central nervous system (CNS)-mediated glucoregulation, we examined the effects of the H1 receptor antagonist pyrilamine and the H2 receptor antagonist ranitidine on neostigmine-induced hyperglycemia in anesthetized rats. The injection of pyrilamine (5 x 10(-9)-5 x 10(-7) mol) into the third cerebral ventricle suppressed hyperglycemia induced by intraventricular injection of neostigmine (1 x 10(-9) mol) in a dose-dependent manner. Injection of ranitidine (5 x 10(-9)-5 x 10(-7) mol) into the third cerebral ventricle did not suppress the hyperglycemia induced by neostigmine, but enhanced it in a dose-dependent manner. These findings suggest that neostigmine-induced CNS-mediated hyperglycemia is transmitted by not only brain cholinergic muscarinic receptors but also in part by histamine H1 receptors.
Asunto(s)
Glucemia/metabolismo , Encéfalo/metabolismo , Hiperglucemia/metabolismo , Receptores Histamínicos H1/fisiología , Receptores Histamínicos H2/fisiología , Animales , Glucemia/efectos de los fármacos , Masculino , Neostigmina/antagonistas & inhibidores , Pirilamina/farmacología , Ranitidina/farmacología , Ratas , Ratas EndogámicasRESUMEN
We investigated the effect of GABA receptor agonists on the central nervous system (CNS)-mediated hyperglycemia induced by neostigmine or histamine in anesthetized fed rats. The injection of muscimol, GABAA receptor agonist (1, 2.5 nmol) into the third cerebral ventricle suppressed the hyperglycemia induced by intraventricular injection of neostigmine (1 x 10(-8) mol) or histamine (5 x 10(-7) mol). Baclofen, GABAB receptor agonist (1, 2.5 nmol), however, did not suppress these hyperglycemia. Neither muscimol nor baclofen (2.5 nmol) affected plasma glucose levels. These findings suggest that activation of GABAA receptor in the CNS suppresses the hyperglycemia induced by the stimulation of cholinoceptive neuron or histaminergic neuron, but activation of GABAB receptor does not affect them.
Asunto(s)
Encéfalo/fisiología , Encéfalo/ultraestructura , Sistema Nervioso Central/fisiología , Antagonistas de los Receptores Histamínicos/farmacología , Histamina , Hiperglucemia/tratamiento farmacológico , Neostigmina/antagonistas & inhibidores , Receptores de GABA-A/efectos de los fármacos , Animales , Baclofeno/farmacología , Encéfalo/efectos de los fármacos , Sistema Nervioso Central/efectos de los fármacos , Hiperglucemia/inducido químicamente , Hiperglucemia/prevención & control , Inyecciones Intraventriculares , Masculino , Muscimol/farmacología , Ratas , Ratas Wistar , Receptores de GABA-A/fisiologíaRESUMEN
We investigated the effects of intrahypothalamic or hippocampal injection of GABA receptor agonists on hyperglycemia induced by hippocampal neostigmine. Prior to the injection of neostigmine (50 nmol) into the hippocampus (HPC), muscimol (0.01-1 nmol) or baclofen (1 nmol) was injected into the bilateral ventromedial hypothalamus (VMH). Muscimol suppressed the hyperglycemia in a dose-dependent manner, but baclofen affected it only minimally. In contrast, neither hippocampal muscimol (1 or 2.5 nmol) nor baclofen (1 nmol) suppressed the hippocampal neostigmine-dependent hyperglycemia. Intrahypothalamic muscimol (1 nmol) also decreased the changes in hepatic venous plasma glucagon and epinephrine significantly. These results indicate that intrahypothalamic muscimol suppresses hyperglycemia caused by cholinergic neurons originating from the HPC, indicating existence of the location specificity.
Asunto(s)
Glucemia/metabolismo , Hipocampo/efectos de los fármacos , Hiperglucemia/prevención & control , Muscimol/administración & dosificación , Muscimol/farmacología , Neostigmina/farmacología , Núcleo Hipotalámico Ventromedial/efectos de los fármacos , Análisis de Varianza , Animales , Baclofeno/administración & dosificación , Baclofeno/farmacología , Glucemia/efectos de los fármacos , Epinefrina/sangre , Venas Hepáticas , Hipocampo/fisiología , Hiperglucemia/inducido químicamente , Insulina/sangre , Masculino , Microinyecciones , Neostigmina/administración & dosificación , Norepinefrina/sangre , Ratas , Ratas Wistar , Técnicas Estereotáxicas , Núcleo Hipotalámico Ventromedial/fisiologíaRESUMEN
This study evaluated the effect of stimulating the central nervous system (CNS) with neostigmine, an inhibitor of acetylcholinesterase, on the blood lactate concentration in fed rats and in rats fasted for 48 hours. After the rat was anesthetized with pentobarbital, neostigmine was stereotaxically injected into the third cerebral ventricle. In fed rats, the central injection of neostigmine significantly increased the blood lactate level, while concomitantly increasing plasma glucagon, epinephrine and norepinephrine concentrations. Constant infusion of somatostatin throughout the experiments, to inhibit glucagon secretion from the pancreas, did not affect alterations in blood lactate by central injection of neostigmine. In adreno-medullated rats, CNS-stimulation by neostigmine still increased plasma norepinephrine significantly, however, the alteration in blood lactate was only one-third of that in intact rats. Intraperitoneal propranolol, but not phentolamine, prevented the rise in lactate. Neostigmine increased lactate in fasted rats as well as in fed rats. We conclude that in anesthetized rats, stimulation of the CNS by neostigmine increases blood lactate mainly through circulating epinephrine and partially through circulating norepinephrine or direct sympathetic nervous stimulation; glucagon does not appear to be involved in the increase in blood lactate.
Asunto(s)
Glucemia/metabolismo , Ventrículos Cerebrales/fisiología , Lactatos/sangre , Neostigmina/farmacología , Somatostatina/farmacología , Anestesia General , Animales , Glucemia/efectos de los fármacos , Ventrículos Cerebrales/efectos de los fármacos , Ingestión de Alimentos , Epinefrina/sangre , Ayuno , Glucagón/sangre , Glucagón/metabolismo , Infusiones Intravenosas , Inyecciones Intraventriculares , Ácido Láctico , Masculino , Neostigmina/administración & dosificación , Norepinefrina/farmacología , Pentobarbital , Fentolamina/farmacología , Propranolol/farmacología , Ratas , Ratas Wistar , Valores de Referencia , Somatostatina/administración & dosificación , Técnicas Estereotáxicas , Factores de TiempoRESUMEN
The potential initiation activities of a novel monoamine oxidase type-A (MAO-A) inhibitor E2011, which induced preneoplastic foci in the rat liver, were investigated by comparing the mutagenic activity of E2011, 6-aminobenzothiazole (6-ABT, a structural scaffold of E2011) and its derivatives, which are suggested primary reactive metabolites for E2011-induced hepatotoxicity in the rats in vivo, in the Ames assay system employing two Salmonella tester strains, TA100 and YG1029, a bacterial O-acetyltransferase-overproducing strain of TA100. E2011, a tertiary amine, showed no mutagenic activity both in the Salmonella typhimurium TA100 and YG1029 with and without S9 mix. On the other hand, a secondary aromatic amine ER-174238-00, a typical decarbonated metabolite of E2011, showed weak but significant mutagenicity in YG1029 in the presence of S9 mix, and a primary aromatic amine ER-174237-00, an N-dealkylated derivative of ER-174238-00, exhibited S9-dependent potent mutagenicity in YG1029. Thus, it appears that primary and secondary amino moieties of benzothiazole derivatives at C(6)-position are the specific structures contributing to their mutagenic activity. In addition, the alkyl group at C(2)-position of E2011, ER-174237-00 and ER-174238-00 is suggested to intensify the mutagenic activity, since the mutagenicity of ER-174237-00 is approximately two-fold higher than that of 6-ABT, which has hydrogen at C(2)-position in the place of the alkyl group. These results strongly suggest that E2011 has potential initiation activities in the rat liver in vivo after undergoing decarbonation, one of the metabolic pathways, at the carbonyl moiety of oxazolidinone ring to form mutagenic amine(s).