RESUMEN
We examined the mechanism by which 24(R)-ethyllophenol (MAB28) isolated from the branches of Morus alba caused neurite outgrowth in rat pheochromocytoma cells (PC12). MAB28 significantly promoted neurite outgrowth to a similar degree as the positive control, nerve growth factor (NGF). After incubation with MAB28 in PC12 cells, phosphorylation of extracellular signal-regulated kinase, p38 mitogen-activated protein kinase, and cyclic AMP response element-binding protein was detected, but the time course of phosphorylation was different from that induced by NGF. The expression of chloride intracellular channel protein 3 (CLIC3) was significantly decreased by MAB28. 5-Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), an outward rectifying chloride channel inhibitor, significantly promoted neurite outgrowth in PC12 cells. These data suggested that MAB28 could induce neurite outgrowth by downregulating CLIC3 expression.
Asunto(s)
Morus , Neuritas , Animales , Células PC12 , Ratas , Morus/química , Neuritas/efectos de los fármacos , Proyección Neuronal/efectos de los fármacos , Factor de Crecimiento Nervioso/farmacología , Fosforilación , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Nitrobenzoatos/farmacología , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Fenoles/farmacología , Western Blotting , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Canales de CloruroRESUMEN
Semantic representations are processed along a posterior-to-anterior gradient reflecting a shift from perceptual (e.g., it has eight legs) to conceptual (e.g., venomous spiders are rare) information. One critical region is the anterior temporal lobe (ATL): patients with semantic variant primary progressive aphasia (svPPA), a clinical syndrome associated with ATL neurodegeneration, manifest a deep loss of semantic knowledge. We test the hypothesis that svPPA patients perform semantic tasks by over-recruiting areas implicated in perceptual processing. We compared MEG recordings of svPPA patients and healthy controls during a categorization task. While behavioral performance did not differ, svPPA patients showed indications of greater activation over bilateral occipital cortices and superior temporal gyrus, and inconsistent engagement of frontal regions. These findings suggest a pervasive reorganization of brain networks in response to ATL neurodegeneration: the loss of this critical hub leads to a dysregulated (semantic) control system, and defective semantic representations are seemingly compensated via enhanced perceptual processing.
Asunto(s)
Afasia Progresiva Primaria/fisiopatología , Degeneración Nerviosa/fisiopatología , Neuronas/fisiología , Semántica , Lóbulo Temporal/fisiopatología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Malignant gliomas are highly resistant to chemotherapy and radiation and more effective options for treatment are urgently needed. We reported previously that the aromatic amide brefelamide, which is isolated from methanolic extracts of the cellular slime molds Dictyostelium giganteum and D. brefeldianum, hinders cellular proliferation in a glioma model utilizing 1321N1 human astrocytoma cells. Herein, we examined the mechanisms underlying the inhibition of 1321N1 cell proliferation by brefelamide. Glial cell line-derived neurotrophic factor (GDNF) was found to enhance the rate of proliferation of serum-free cultured 1321N1 cells, but did not affect proliferation in PC12 cells. Brefelamide pretreatment inhibited GDNF-induced cell proliferation and expression of rearranged during transfection (RET). GDNF enhanced the phosphorylation of extracellular signal-regulated kinase (ERK), AKT, and c-jun-N-terminal kinase (JNK); however, brefelamide pretreatment inhibited these effects. Brefelamide also reduced the expression of GDNF mRNA and GDNF secretion. Together, the findings from this study indicate that brefelamide inhibits the proliferation of 1321N1 cell via several mechanisms including reduced GDNF receptor expression and GDNF secretion, and reduced phosphorylation of ERK, AKT, and JNK.
Asunto(s)
Amidas/farmacología , Antineoplásicos/farmacología , Astrocitoma/tratamiento farmacológico , Proliferación Celular/efectos de los fármacos , Fenoles/farmacología , Animales , Astrocitoma/genética , Astrocitoma/patología , Línea Celular Tumoral , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Factor Neurotrófico Derivado de la Línea Celular Glial/metabolismo , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial/genética , Glioma/tratamiento farmacológico , Glioma/patología , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Células PC12 , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Mensajero/metabolismo , RatasRESUMEN
There has been no consensus on the role of serum androgen concentrations in prostate cancer detection in men with prostate-specific antigen levels of 3-10 ng/mL. In this study, testosterone and dihydrotestosterone concentrations in blood were examined by a newly developed method using ultrasensitive liquid chromatography with two serially linked mass spectrometers (LC-MS/MS). We investigated the correlation between serum androgen levels and Gleason scores at biopsy. We analyzed data of 157 men with a total prostate-specific antigen range of 3-10 ng/mL who underwent initial systematic prostate needle biopsy for suspected prostate cancer between April 2000 and July 2003. Peripheral blood testosterone and dihydrotestosterone concentrations were determined by LC-MS/MS. Blood levels of testosterone and dihydrotestosterone were compared with pathological findings by multivariate analyses. Median values of prostate-specific antigen and prostate volume measured by ultrasound were 5.7 ng/mL and 31.4 cm3 , respectively. Benign prostatic hyperplasia was diagnosed in 97 patients (61.8%), and prostate cancer was diagnosed in 60 (38.2%) patients, including 31 (19.7%) patients with a Gleason score of 6 and 29 (18.5%) patients with a Gleason score of 7-10. Median values of testosterone and dihydrotestosterone in blood were 3798.7 and 371.7 pg/mL, respectively. There was a strong correlation between serum testosterone and dihydrotestosterone. In multivariate analysis, age, prostate volume, and serum dihydrotestosterone were significant predictors of benign prostatic hyperplasia or prostate cancer with a Gleason score of 6. The area under the receiver operating characteristics curve for age, prostate volume, and serum dihydrotestosterone were 0.67, 0.67, and 0.67, respectively . We confirmed that high dihydrotestosterone blood levels can predict benign prostatic hyperplasia or prostate cancer with a Gleason score of 6 in men with prostate-specific antigen levels of 3-10 ng/mL.
Asunto(s)
Adenocarcinoma/diagnóstico , Dihidrotestosterona/sangre , Antígeno Prostático Específico/sangre , Hiperplasia Prostática/diagnóstico , Neoplasias de la Próstata/diagnóstico , Adenocarcinoma/sangre , Adenocarcinoma/patología , Anciano , Anciano de 80 o más Años , Cromatografía Liquida , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Próstata/patología , Hiperplasia Prostática/sangre , Hiperplasia Prostática/patología , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/patología , Espectrometría de Masas en Tándem , Testosterona/sangreRESUMEN
Great advances in tissue androgen analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) have made it possible to evaluate the tissue androgen content from a single needle prostate biopsy specimen. In this study, we investigated if pre-treatment androgen content in prostate biopsy specimens could predict their response to primary androgen deprivation therapy (ADT) and future castration-resistant prostate cancer (CRPC). One-hundred and sixty-five prostate cancer patients who received primary ADT were enrolled. They had received multiple core prostate needle biopsy at diagnosis, and an additional one needle biopsy specimen was obtained for tissue androgen determination using LC-MS/MS. The patients' prostate specific antigen (PSA) values were periodically followed during the treatment and patients were determined to have CRPC when their PSA value increased continuously to 25% above the nadir and a 2.0 ng/mL increase. A significant correlation was found between PSA value decline velocity (PSA half-time) after ADT and pre-ADT tissue androgen content. Twenty-three patients were determined to have CRPC. These CRPC patients had a significantly high concentration of tissue T (p < 0.01) and low concentration of tissue 5α-dihydrotestosterone (DHT) (p < 0.01), resulting in a higher tissue T/DHT ratio (p < 0.001). A multivariate Cox proportional hazard model revealed the pre-ADT tissue T/DHT ratio and Gleason score as independent predictors for CRPC development. By using the two statistically significant variables, the relative risk of CRPC development could be calculated. The results of this study suggest that the evaluation of prostate androgen content in a single needle biopsy specimen may be useful to predict future CRPC development after primary ADT. Further studies are required for the clinical application of T/DHT ratio evaluation.
Asunto(s)
Antagonistas de Andrógenos/uso terapéutico , Andrógenos/metabolismo , Orquiectomía , Próstata/metabolismo , Neoplasias de la Próstata/etiología , Anciano , Humanos , MasculinoRESUMEN
Intratumoural steroidogenesis may play a significant role in the progression of prostate cancer (PC) in the context of long-term ablation of circulating testosterone (T). To clarify the mechanism accounting for the progression of PC in a 74-year-old man who had undergone bilateral orchiectomy when he was 5 years old, we performed immunohistochemical studies of androgen receptor (AR) and steroidogenic enzymes in the prostate. We also measured steroid hormone levels in the serum and prostate, as well as mRNA levels of genes mediating androgen metabolism in the prostate. Positive nuclear staining of AR was detected in malignant epithelial cells. The levels of androstenedione (Adione), T, and 5-alpha dihydrotestosterone (DHT) in the serum of the patient were similar to those in PC patients receiving neoadjuvant androgen deprivation therapy (ADT), but were higher in the patient's prostate than in PC patients not receiving ADT. The gene expression of CYP17A1 and HSD3B1 was not detected, whereas that of STS, HSD3B2, AKR1C3, SRD5A1, and SRD5A2 was detected. Moreover, cytoplasmic staining of HSD3B2, AKR1C3, SRD5A1, and SRD5A2 was detected in malignant epithelial cells. Hence, in the present case (a man with primary hypogonadism), steroidogenesis in PC tissues from adrenal androgens, especially dehydroepiandrosterone sulphate, was the mechanism accounting for progression of PC. This mechanism might help elucidate the development of castration-resistant PC.
Asunto(s)
Hormonas Esteroides Gonadales/metabolismo , Hipogonadismo/etiología , Orquiectomía/efectos adversos , Neoplasias de la Próstata/metabolismo , Anciano , Androstenodiona/metabolismo , Dihidrotestosterona/metabolismo , Progresión de la Enfermedad , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Hormonas Esteroides Gonadales/sangre , Humanos , Hipogonadismo/metabolismo , Inmunohistoquímica , Masculino , Neoplasias de la Próstata/etiología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , ARN Mensajero/metabolismo , Receptores Androgénicos/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Testosterona/metabolismoRESUMEN
The skeletal elements of embryonic limb are prefigured by prechondrogenic condensation in which secreted molecules such as adhesion molecules and extracellular matrix have crucial roles. However, how the secreted molecules are controlled to organize the condensation remains unclear. In this study, we examined metabolic regulation of secretion in prechondrogenic condensation, using bioluminescent monitoring systems. We here report on ATP oscillations in the early step of chondrogenesis. The ATP oscillations depended on both glycolysis and mitochondrial respiration, and their synchronization among cells were achieved via gap junctions. In addition, the ATP oscillations were driven by Ca(2+) oscillations and led to oscillatory secretion in chondrogenesis. Blockade of the ATP oscillations prevented cellular condensation. Furthermore, the degree of cellular condensation increased with the frequency of ATP oscillations. We conclude that ATP oscillations have a critical role in prechondrogenic condensation by inducing oscillatory secretion.
Asunto(s)
Adenosina Trifosfato/metabolismo , Condrogénesis/fisiología , Mitocondrias/metabolismo , Transducción de Señal/fisiología , Células Madre/metabolismo , Animales , Calcio/metabolismo , Recuento de Células , Línea Celular Tumoral , Uniones Comunicantes/metabolismo , Genes Reporteros , Glucólisis , Humanos , Luciferasas , Mediciones Luminiscentes , Ratones , Fosforilación Oxidativa , Células Madre/citologíaAsunto(s)
Estradiol/análisis , Estrona/análisis , Carne , Neoplasias Ováricas/química , Neoplasias Uterinas/química , Animales , Bovinos , Cromatografía Liquida , Femenino , Humanos , Japón , Carne/efectos adversos , Estadificación de Neoplasias , Neoplasias Ováricas/patología , Espectrometría de Masas en Tándem , Estados Unidos , Neoplasias Uterinas/patologíaRESUMEN
We evaluated the reliability and efficacy of the ultrasonically activated scalpel (Harmonic Scalpel) for pulmonary resection in video-assisted thoracoscopic surgery (VATS). Fifty-six cases of primary or metastatic lung cancer with history of lobectomy or segmentectomy from July 2003 to June 2006 were investigated. The ultrasonically activated scalpel was used to separate aborted lobulation and segment in the surgery. The outcome of the operation using the ultrasonically activated scalpel revealed the mean operation time of 224.5 minutes and mean blood loss volume of 116.7 ml. The chest drainage catheter was removed at the postoperative day 3.4 and hospitalization lasted 10.4 days on average. By means of statistical analysis, no significant differences were noted when compared with the cases using surgical stapler to separate the lobules or segments of the lungs. Histopathological results showed destruction of alveolar structures and denaturation of cells at the cut surface of the resected lung through the use of the ultrasonically activated scalpel. This method resulted in good lung expansion and preservation of the residual lung volume. Furthermore, it prevented postoperative air leakage by appropriate treatment to the cut surfaces of the residual lung. Indeed, the method appears to be useful in the separation of lung tissues in severe aborted lobulation and segmentectomy by VATS.
Asunto(s)
Electrocoagulación/instrumentación , Neoplasias Pulmonares/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Neumonectomía/instrumentación , Cirugía Torácica Asistida por Video/instrumentación , Ultrasonido , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonectomía/métodos , Cirugía Torácica Asistida por Video/métodos , Resultado del TratamientoRESUMEN
Clock genes, which mediate molecular circadian rhythms, are expressed in a circadian fashion in the suprachiasmatic nucleus and in various peripheral tissues. To establish a molecular basis for circadian regulation in the salivary glands, we examined expression profiles of clock-related genes and salivary gland-characteristic genes. Clock-related genes-including Per1, Per2, Cry1, Bmal1, Dec1, Dec2, Dbp, and Reverbalpha-showed robust circadian expression rhythms in the submandibular glands in 12:12-hour light-dark conditions. In addition, a robust circadian rhythm was observed in amylase 1 mRNA levels, whereas the expression of other salivary-gland-characteristic genes examined was not rhythmic. The Clock mutation resulted in increased or decreased mRNA levels of Per2, Bmal1, Dec1, Dec2, and Dbp, and in Cry1-/- background, Cry2 disruption also increased or decreased mRNA levels of these clock-related genes and the amylase 1 gene. These findings indicate that the Clock- and Cry-dependent molecular clock system is active in the salivary glands.
Asunto(s)
Ritmo Circadiano/genética , Glándula Submandibular/metabolismo , Transactivadores/análisis , Factores de Transcripción ARNTL , Amilasas/análisis , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/análisis , Relojes Biológicos/genética , Proteínas CLOCK , Proteínas de Ciclo Celular , Criptocromos , Proteínas de Unión al ADN/análisis , Flavoproteínas/análisis , Secuencias Hélice-Asa-Hélice/genética , Proteínas de Homeodominio/análisis , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Proteínas Nucleares/análisis , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares , Proteínas Circadianas Period , Receptores Citoplasmáticos y Nucleares/análisis , Glándula Submandibular/enzimología , Factores de Transcripción/análisisRESUMEN
OBJECTIVE: To clarify the clinical significance and etiologic impact of Norwalk virus (NV) and Sapporo virus (SV) in viral gastroenteritis in Japanese children. STUDY DESIGN: Two outbreaks each of NV gastroenteritis and SV gastroenteritis occurring in an infant home in Sapporo, Japan, as well as 95 hospitalized children with acute gastroenteritis were retrospectively evaluated using a 0- to 20-point clinical severity scoring system. RESULTS: The mean severity scores for NV and SV gastroenteritis outbreaks were 7.9 and 5.2, respectively, as compared with 8.4 for rotavirus A gastroenteritis that occurred in the same infant home. Among 95 hospitalized children with acute gastroenteritis, rotavirus A was detected in 47% followed by NV in 18%. SV was not found. CONCLUSION: Our data indicate that NV can cause severe gastroenteritis and is an important etiologic agent in hospitalized cases, whereas SV causes mild gastroenteritis in Japanese children.
Asunto(s)
Infecciones por Caliciviridae/diagnóstico , Infecciones por Caliciviridae/epidemiología , Brotes de Enfermedades , Gastroenteritis/epidemiología , Gastroenteritis/virología , Virus Norwalk/aislamiento & purificación , Sapovirus/aislamiento & purificación , Enfermedad Aguda , Preescolar , Heces/virología , Femenino , Gastroenteritis/fisiopatología , Hospitalización , Humanos , Incidencia , Lactante , Japón/epidemiología , Masculino , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Estadísticas no ParamétricasRESUMEN
We investigated the constituents of Dictyostelium discoideum to clarify the diversity of secondary metabolites of Dictyostelium cellular slime molds and to explore biologically active substances that could be useful in the development of novel drugs. From a methanol extract of the multicellular fruit body of D. discoideum, we isolated two novel amino sugar analogues, furanodictine A (1) and B (2). They are the first 3,6-anhydrosugars to be isolated from natural sources. Their relative structures were elucidated by spectral means, and the absolute configurations were confirmed by asymmetric syntheses of 1 and 2. These furanodictines potently induce neuronal differentiation of rat pheochromocytoma (PC-12) cells.
Asunto(s)
Amino Azúcares/química , Amino Azúcares/farmacología , Antineoplásicos/química , Dictyostelium/química , Amino Azúcares/aislamiento & purificación , Animales , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Diferenciación Celular/efectos de los fármacos , Sinergismo Farmacológico , Conformación Molecular , Estructura Molecular , Factor de Crecimiento Nervioso/farmacología , Neuritas/efectos de los fármacos , Neuritas/ultraestructura , Neuronas/efectos de los fármacos , Neuronas/patología , Neuronas/ultraestructura , Resonancia Magnética Nuclear Biomolecular , Ratas , Células Tumorales CultivadasRESUMEN
CS mice exhibit a spontaneous splitting in the circadian rhythm of locomotor activity under constant darkness, suggesting that they contain two weakly coupled oscillators in the circadian clock system regulating locomotor activity rhythm. In order to clarify whether the two oscillators are located in the suprachiasmatic nucleus (SCN), a site of the master circadian pacemaker in mammals, circadian rhythms in mRNA of mouse Period genes (mPer1, mPer2 and mPer3) in the SCN and cerebral cortex were examined during rhythm splitting by in situ hybridization. In the SCN, mPer1 and mPer2 showed a circadian rhythm with a single peak in both split and unsplit mice. The rhythms of mPer1 and mPer2 were slightly phase delayed during rhythm splitting in reference to the activity onset, but the phase relationship between the two rhythms was not changed. In the cerebral cortex, the expression of mPer1 and mPer2 underwent the bimodal fluctuation with peaks temporally corresponding to split activity components. The unsplit mice showed the circadian rhythms with a single peak. There was no difference in the mPer3 rhythms in either the SCN or the cerebral cortex between the split and unsplit mice. These results indicate that the circadian oscillations of mPer1, mPer2 and mPer3 in the SCN are not related to the rhythm splitting of CS mice. The split rhythms of the CS mice are suggested to be caused by uncoupling of oscillators located outside the SCN from the SCN circadian pacemaker.
Asunto(s)
Relojes Biológicos/genética , Ritmo Circadiano/genética , Regulación de la Expresión Génica/fisiología , Ratones Endogámicos/metabolismo , Proteínas Nucleares/genética , Núcleo Supraquiasmático/metabolismo , Animales , Proteínas de Ciclo Celular , Giro del Cíngulo/citología , Giro del Cíngulo/metabolismo , Ratones , Ratones Endogámicos C57BL/anatomía & histología , Ratones Endogámicos C57BL/metabolismo , Ratones Endogámicos/anatomía & histología , Actividad Motora/genética , Vías Olfatorias/citología , Vías Olfatorias/metabolismo , Proteínas Circadianas Period , ARN Mensajero/metabolismo , Núcleo Supraquiasmático/citología , Factores de TranscripciónRESUMEN
It is well established that the Clock gene is essential for expressing circadian activity rhythms in mammals under constant darkness. The Clock gene product is a positive component of a molecular feedback loop which is assumed to generate the circadian rhythm. On the other hand, chronic treatment of methamphetamine (MAP) induces locomotor activity rhythm in a circadian domain, which is independent of the suprachiasmatic nucleus (SCN) and is driven by a pacemaker outside the SCN. However, it is not known whether the pacemaker outside the SCN possesses a similar molecular mechanism to that in the SCN. Here we show that MAP restores locomotor activity rhythm in arrhythmic homozygous Clock mutant (Clock/Clock) mice under constant darkness. This result indicates that the Clock mutation does not affect the MAP-induced locomotor rhythm.
Asunto(s)
Relojes Biológicos/efectos de los fármacos , Encéfalo/efectos de los fármacos , Ritmo Circadiano/efectos de los fármacos , Metanfetamina/farmacología , Actividad Motora/efectos de los fármacos , Mutación/efectos de los fármacos , Transactivadores/efectos de los fármacos , Animales , Relojes Biológicos/genética , Encéfalo/metabolismo , Proteínas CLOCK , Ritmo Circadiano/genética , Ratones , Ratones Mutantes , Actividad Motora/fisiología , Mutación/fisiología , Transactivadores/genética , Transactivadores/metabolismoRESUMEN
Roxatidine acetate hydrochloride (ROX, 2-acetoxy-N-[3-[m-(1-piperidinylmethyl)phenoxy]propyl]acetamide hydrochloride, CAS 78273-80-0), a histamine 2 (H2)-receptor antagonist, has been clinically applied for the treatment of gastritis, gastric and duodenal ulcers. There is no report on the identification of the metabolic enzyme of M-1 (2-hydroxy-N-[3-[m-(1-piperidinylmethyl)phenoxy]propyl]acetamide), the pharmacologically active metabolite, in humans. In this study, the Cytochrome P450 (CYP or P450) enzymes which participate in the metabolism of ROX were identified using human liver microsomes and S9 fractions. M-1 was converted to M-4 (3-[m-(1-piperidinyl-methyl)phenoxy]propylamine) by the enzyme reaction with the S9 but not with microsomes. M-4 was further metabolized to M-5 (3-[m-(1-piperidinylmethyl)phenoxy]propanol) by microsomes. The metabolism was inhibited by coumarin and anti-CYP2A1 serum. (3-[m-(1-piperidinylmethyl)-phenoxy]propionic acid) and M-3 (m-(1-piperidinylmethyl) phenol) formation from M-5 were inhibited by quinidine and anti-CYP2D6 serum. Moreover, M-5 was converted to M-2 and M-3 by cDNA-expressed CYP2D6. In conclusion, this study shows that microsomal enzymes do not participate in the clearance of the active metabolite M-1, CYP2A6 primarily catalyzes M-5 formation from M-4, and CYP2D6 primarily catalyzes M-2 and M-3 formation from M-5 in humans.
Asunto(s)
Sistema Enzimático del Citocromo P-450/metabolismo , Antagonistas de los Receptores H2 de la Histamina/metabolismo , Microsomas Hepáticos/metabolismo , Piperidinas/metabolismo , Cromatografía Líquida de Alta Presión , Inhibidores Enzimáticos del Citocromo P-450 , Inhibidores Enzimáticos/farmacología , Humanos , Técnicas In Vitro , Isoenzimas/metabolismo , Cinética , Sistema Linfático/citología , Sistema Linfático/efectos de los fármacos , Sistema Linfático/metabolismo , Microsomas Hepáticos/enzimología , Espectrofotometría Ultravioleta , Fracciones Subcelulares/enzimología , Fracciones Subcelulares/metabolismoRESUMEN
Norwalk virus and Sapporo virus (SV) were approved as type species of the genus Norwalk-like viruses and the genus Sapporo-like viruses, respectively, in the family Caliciviridae. Nested polymerase chain reaction (PCR), using newly designed primers in the RNA-dependent RNA polymerase region, was developed to detect and differentiate viruses in the three genetic groups of SV based on the relative size of the PCR products obtained. In addition, a booster nested PCR that performs nested PCR in a single tube was introduced to reduce the chance of contamination during the procedure of standard nested PCR. The specificity of the newly developed PCR was confirmed by testing 77 stool specimens and 16 tissue culture fluids derived from growth of unrelated viruses. The sensitivity of the nested PCR was compared with the conventional PCR using Sapp35/Sapp36 primer pair by testing the three cDNA clones obtained from viruses in the SV/SV82, the SV/London92, and the SV/Parkville virus, respectively. This assay can detect SV in a more sensitive way than the conventional PCR and Southern hybridization. Sensitive and suitable methods to detect and differentiate SV are required to obtain accurate epidemiological data on these viruses and the standard and booster nested PCR should be a very useful tool for this purpose.
Asunto(s)
Infecciones por Caliciviridae/virología , Caliciviridae/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Caliciviridae/genética , Cartilla de ADN , Heces/virología , Humanos , Valor Predictivo de las Pruebas , ARN Viral/análisisRESUMEN
Regional specificities of the dorsal and ventral regions of the suprachiasmatic nucleus (SCN) were examined to elucidate the structure of multioscillator circadian organization. The circadian rhythms of arginine vasopressin (AVP) and vasoactive intestinal polypeptide (VIP) release, and of electrical activity of individual neurons were measured in an organotypic, static slice culture of the SCN obtained from neonatal rats. Five days after the start of culture, robust circadian rhythms were detected in AVP release with a peak located consistently at the middle of the original light phase, while the 24 h profiles of VIP release were either arrhythmic or rhythmic. In the latter case, a phase delay of 5-7 h was observed in the circadian peak from the AVP rhythm. Multi-channel, extracellular recording revealed that 51 (76.1%) out of 67 firing neurons, examined in the SCN, showed circadian rhythms in their firing rate. The percentage of rhythmic neurons was significantly larger in the dorsal (86.8%) than in the ventral (62.1%) region of the SCN, where the AVP and VIP containing neurons predominate, respectively. Twenty-seven percent of the firing rhythms were almost antiphasic from the majority of rhythms. There was no regional specificity in the distribution of the antiphasic rhythm. These findings, that the dorsal and ventral regions of the SCN both contain circadian pacemakers with different properties that regulate the AVP and VIP release separately, is probably due to differences in the number and, hence, the coupling strength of oscillating neurons.
Asunto(s)
Potenciales de Acción/fisiología , Arginina Vasopresina/metabolismo , Relojes Biológicos/fisiología , Ritmo Circadiano/fisiología , Neuronas/metabolismo , Núcleo Supraquiasmático/metabolismo , Péptido Intestinal Vasoactivo/metabolismo , Animales , Animales Recién Nacidos , Comunicación Celular/fisiología , Inmunohistoquímica , Neuronas/citología , Ratas , Ratas Wistar , Núcleo Supraquiasmático/citologíaRESUMEN
Effects of dietary consistency were examined on the development and persistence of meal anticipation in adrenocortical activity in rats under restricted daily feeding (RF), in which food supply was restricted to a fixed time of day. Restricted daily solid meal produced the anticipatory hormone peak in 8 days, whereas restricted daily liquid meal produced the peak in 12 days. The developed hormone peak was less prominent by liquid meal than by solid. The anticipatory corticosterone peak developed by solid meal persisted throughout the period examined (3 weeks) after the termination of RF, whereas the peak developed by liquid meal disappeared after the first week. It is concluded that liquid meal attenuates the meal anticipation in the adrenocortical activity in rats under RF.
Asunto(s)
Corteza Suprarrenal/fisiología , Dieta , Conducta Alimentaria/fisiología , Animales , Peso Corporal/efectos de los fármacos , Corticosterona/sangre , Masculino , Ratas , Ratas WistarRESUMEN
A previous study revealed that rostrodorsomedial oralis (Vo.r) neurons synapsing on trigeminal motoneurons use GABA and/or glycine as neurotransmitters. To determine the number and spatial distribution of contacts, injections of biotinamide and horseradish peroxidase were made into a Vo.r neuron and an alpha-motoneuron in the jaw-closing (JC) and jaw-opening (JO) motor nucleus, respectively, in 39 cats. All Vo.r neurons responded to low-threshold mechanical stimulation of the oral tissues. Single Vo.r neurons terminating in the JC nucleus (Vo.r-dl neurons; n = 5) issued, on average, 10 times more boutons than Vo.r neurons terminating in the JO nucleus (Vo.r-vm neurons; n = 5; 4437 vs 445). The Vo.r-dl neuron-JC alpha-motoneuron pairs (n = 4) made contacts on either the soma-dendritic compartment or dendrites, and the Vo.r-vm neuron-JO motoneuron pairs (n = 2) made contacts on dendrites, with a range of two to seven contacts. In five of the six pairs, individual or groups of two to three terminals contacted different dendritic branches of a postsynaptic cell. The Vo.r-dl neurons innervated a greater number of counter-stained motoneuronal somata than did the Vo.r-vm neurons (216 vs 26). Total number of contacts per Vo.r neuron was higher for the Vo.r-dl than Vo.r-vm neurons (786 vs 72). The present study demonstrates that axonal branches of Vo.r neurons are divided into two types with different innervation domains on the postsynaptic neuron and that they are highly divergent. The overall effect exerted by these neurons is predicted to be much greater within the JC than JO motoneuron pool.
Asunto(s)
Biotina/análogos & derivados , Neuronas/citología , Neuronas/fisiología , Puente/citología , Sinapsis/ultraestructura , Nervio Trigémino/citología , Potenciales de Acción/fisiología , Animales , Gatos , Recuento de Células , Dendritas/ultraestructura , Estimulación Eléctrica , Potenciales Postsinápticos Excitadores/fisiología , Peroxidasa de Rábano Silvestre , Maxilares , Músculo Masetero/inervación , Neuronas Motoras/citología , Neuronas Motoras/fisiología , Neuronas/clasificación , Estimulación Física , Terminales Presinápticos/ultraestructura , Umbral Sensorial/fisiologíaRESUMEN
The suprachiasmatic nucleus (SCN) of the hypothalamus is the site of the pacemaker that controls circadian rhythms of a variety of physiological functions. Data strongly indicate the majority of the SCN neurons express self-sustaining oscillations that can be detected as rhythms in the spontaneous firing of individual neurons. The period of single SCN neurons in a dissociated cell culture is dispersed in a wide range (from 20h to 28h in rats), but that of the locomotor rhythm is close to 24h, suggesting individual oscillators are coupled to generate an averaged circadian period in the nucleus. Electrical coupling via gap junctions, glial regulation, calcium spikes, ephaptic interactions. extracellular ion flux, and diffusible substances have been discussed as possible mechanisms that mediate the interneuronal rhythm synchrony. Recently, GABA (gamma-aminobutyric acid), a major neurotransmitter in the SCN, was reported to regulate cellular communication and to synchronize rhythms through GABA(A) receptors. At present, subsequent intracellular processes that are able to reset the genetic loop of oscillations are unknown. There may be diverse mechanisms for integrating the multiple circadian oscillators in the SCN. This article reviews the knowledge about the various circadian oscillations intrinsic to the SCN, with particular focus on the intercellular signaling of coupled oscillators.