RESUMEN
Cefoselis is a widely used beta-lactam antibiotic, but occasionally induces seizures and convulsion in elder and renal failure patients. However, beta-lactams are known not to pass through the blood-brain barrier (BBB). In this study, we examined the BBB penetration of cefoselis in normal and renal failure rats by means of brain microdialysis. Cefoselis was dose-dependently appeared in brain extracellular fluid in proportion to its blood level. The elimination constant from brain extracellular fluid (apparent) was slightly lower than that from blood. These results indicated that cefoselis might penetrate the BBB or be discharged by a certain transport system. In contrast to the result of cefoselis, cefazolin, a leading drug of cephalosporins, could not be detected in the brain extracellular fluid after an intravenous injection. In renal dysfunction rats, the elimination half-lives of cefoselis from both blood and brain were extensively prolonged. This would be one of responsible factors inducing seizures seen in patients. However, the additional factor, such as decrease in brain function related to aging, would be involved in seizures in patient received cefoselis, because an extremely high dose was required to induce seizures even in renal failure rats. A local administration of cefoselis into the hippocampus through the microdialysis probe caused a striking elevation of extracellular glutamate, with a minimum increase in gamma-aminobutyric acid (GABA). However, a systematic cefoselis administration via the tail vein did not elevate extracellular glutamate and GABA concentrations in the hippocampus of renal failure rats that exhibited marked seizures. These results suggested that not the stimulation of glutamate release, but the blockade of GABA receptors might be responsible for the seizure induced by cefoselis.
Asunto(s)
Antibacterianos/efectos adversos , Antibacterianos/metabolismo , Barrera Hematoencefálica/metabolismo , Ceftizoxima/análogos & derivados , Ceftizoxima/efectos adversos , Ceftizoxima/metabolismo , Convulsiones/etiología , Animales , Antibacterianos/administración & dosificación , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Cefazolina/metabolismo , Ceftizoxima/administración & dosificación , Cromatografía Líquida de Alta Presión , Modelos Animales de Enfermedad , Ácido Glutámico/análisis , Ácido Glutámico/efectos de los fármacos , Ácido Glutámico/metabolismo , Masculino , Microdiálisis , Ratas , Ratas Wistar , Insuficiencia Renal/fisiopatología , Ácido gamma-Aminobutírico/análisis , Ácido gamma-Aminobutírico/efectos de los fármacos , Ácido gamma-Aminobutírico/metabolismoRESUMEN
Carbolines, azaheterocyclic amines derived from indoleamines, have various biological activities, such as neurotoxicity of beta-carbolines and potent mutagenicity of gamma-carbolines. In this study, structural significance among these carbolines was investigated in relation to the types of cell death, apoptosis and necrosis, using human neuroblastoma SH-SY5Y cells. DNA damage was quantitatively analyzed by a single-cell gel electrophoresis assay. DNA damage was induced by both beta-carbolines, harman and norharman, and gamma-carbolines, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-4-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), in a dose dependent manner. Gamma-carbolines were more potent to damage DNA than beta-carbolines. Alkaline lysis of the cells prevented DNA damage induced by beta-carboline, and pre-treatment of the cells with cycloheximide, an inhibitor of protein synthesis, reduced DNA damage caused by norharman. Morphological observation showed condensed and fragmented nuclei typical for apoptosis, in the cells treated with norharman. Thus, DNA damage induced by norharman was proved to be apoptotic. However, harman, which had a methyl substitution at the position 1, might induce necrosis in the cells. On the other hand, gamma-carbolines, Trp-P-1 and Trp-P-2, directly damaged DNA. Thus, the nitrogen atom at the gamma-position and/or an amino group in carboline structure would be required to induce the direct DNA cleavage.
Asunto(s)
Apoptosis/efectos de los fármacos , Carbolinas/toxicidad , Sistema Nervioso Central/efectos de los fármacos , Harmina/análogos & derivados , Harmina/toxicidad , Mutágenos/toxicidad , Neuronas/efectos de los fármacos , Neurotoxinas/toxicidad , Apoptosis/fisiología , Carbolinas/química , Sistema Nervioso Central/metabolismo , Sistema Nervioso Central/fisiopatología , Ensayo Cometa , Cicloheximida/farmacología , ADN/efectos de los fármacos , ADN/metabolismo , Fragmentación del ADN/efectos de los fármacos , Fragmentación del ADN/fisiología , Harmina/química , Humanos , Mutágenos/química , Neuronas/metabolismo , Neurotoxinas/química , Inhibidores de la Síntesis de la Proteína/farmacología , Células Tumorales CultivadasRESUMEN
The role of glutamate in the N-methyl-4-phenyldihydropyridinium (MPP+) toxicity has been argued in the past decade. However, the effects of glutamate efflux and NMDA antagonist on MPP+-induced dopamine overflow have not been documented. To clarify this, we perfused MPP+ through a microdialysis probe in the striatum of freely moving mature C57BL/6 mice. The 60-min perfusion of 10 and 100 microM MPP+ strikingly increased dopamine levels to 28- and 93-fold of the basal values, respectively. In contrast, an administration of MPP+ did not induce marked glutamate release: the MPP+-perfusion slightly increased the glutamate level at 100 microM, but not at 10 microM. The addition of 100 microM (+)-MK-801 or 200 microM (+/-)-AP-7 to the perfusate did not attenuate MPP+-induced dopamine overflow. The extent of dopamine release only depended on the amount of MPP+ accumulation into the cells. These results indicated that, at least in the striatum, neither glutamate release nor the NMDA antagonist, including (+)-MK-801, could regulate MPP+-evoked dopamine overflow.
Asunto(s)
1-Metil-4-fenilpiridinio/toxicidad , Dopamina/metabolismo , Ácido Glutámico/metabolismo , Herbicidas/toxicidad , Neostriado/efectos de los fármacos , Neuronas/efectos de los fármacos , Trastornos Parkinsonianos/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas/fisiología , Antagonistas de Aminoácidos Excitadores/farmacología , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Microdiálisis , Neostriado/metabolismo , Neostriado/fisiopatología , Neuronas/metabolismo , Trastornos Parkinsonianos/fisiopatología , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/metabolismo , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiologíaRESUMEN
Due to the structural similarity to N-methyl-4-phenyl pyridinium (MPP(+)), paraquat might induce dopaminergic toxicity in the brain. However, its blood--brain barrier (BBB) penetration has not been well documented. We studied the manner of BBB penetration and neural cell uptake of paraquat using a brain microdialysis technique with HPLC/UV detection in rats. After subcutaneous administration, paraquat appeared dose-dependently in the dialysate. In contrast, MPP(+) could not penetrate the BBB in either control or paraquat pre-treated rats. These data indicated that the penetration of paraquat into the brain would be mediated by a specific carrier process, not resulting from the destruction of BBB function by paraquat itself or a paraquat radical. To examine whether paraquat was carried across the BBB by a certain amino acid transporter, L-valine or L-lysine was pre-administered as a co-substrate. The pre-treatment of L-valine, which is a high affinity substrate for the neutral amino acid transporter, markedly reduced the BBB penetration of paraquat. When paraquat was administered to the striatum through a microdialysis probe, a significant amount of paraquat was detected in the striatal cells after a sequential 180-min washout with Ringer's solution. This uptake was significantly inhibited by a low Na(+) condition, but not by treatment with putrescine, a potent uptake inhibitor of paraquat into lung tissue. These findings indicated that paraquat is possibly taken up into the brain by the neutral amino acid transport system, then transported into striatal, possibly neuronal, cells in a Na(+)-dependent manner.
Asunto(s)
Sistemas de Transporte de Aminoácidos Básicos , Sistemas de Transporte de Aminoácidos Neutros , Barrera Hematoencefálica/efectos de los fármacos , Encéfalo/efectos de los fármacos , Proteínas Portadoras/efectos de los fármacos , Herbicidas/farmacocinética , Neuronas/efectos de los fármacos , Paraquat/farmacocinética , 1-Metil-4-fenilpiridinio/farmacología , 1-Metil-4-fenilpiridinio/toxicidad , Animales , Barrera Hematoencefálica/fisiología , Encéfalo/citología , Encéfalo/metabolismo , Proteínas Portadoras/metabolismo , Espacio Extracelular/efectos de los fármacos , Espacio Extracelular/metabolismo , Herbicidas/toxicidad , Lisina/farmacología , Masculino , Microdiálisis/métodos , Neostriado/citología , Neostriado/efectos de los fármacos , Neostriado/metabolismo , Neuronas/citología , Neuronas/metabolismo , Paraquat/toxicidad , Putrescina/farmacología , Ratas , Ratas Wistar , Valina/farmacologíaRESUMEN
N-Methyl-4-phenylpyridinium (MPP(+)) and 2,9-di-methyl-norharmanium (2,9-Me2NH(+)), which is a beta-carbolinium proposed as an endogenous MPP(+)-like toxin underlying Parkinson's disease, are strong mitochondrial toxins. We have measured the extracellular lactate levels as a marker for the in vivo cell hypoxia in the striatum of freely moving rats. The perfusions with MPP(+) and 2,9-Me2NH(+) increased extracellular lactate levels in a dose-dependent manner. These increases in lactate levels were significantly prevented by the co-perfusion with 10 microM L-deprenyl, a selective monoamine oxidase (MAO)-B inhibitor, but not by pargyline, a non-specific MAO inhibitor. The increase in extracellular lactate levels was considered to be the reflection of the cell damage resulted from the impairment of mitochondrial function. The present results suggested that L-deprenyl would rescue nerve cells from these toxins through the direct influence on the mitochondrial electron transport.
Asunto(s)
1-Metil-4-fenilpiridinio/toxicidad , Carbolinas/toxicidad , Herbicidas/toxicidad , Inhibidores de la Monoaminooxidasa/toxicidad , Fármacos Neuroprotectores/farmacología , Neurotoxinas/toxicidad , Selegilina/farmacología , Animales , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/fisiología , Dopamina/metabolismo , Relación Dosis-Respuesta a Droga , Espacio Extracelular/metabolismo , Ácido Láctico/metabolismo , Masculino , Microdiálisis , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Mitocondrias/patología , Neostriado/efectos de los fármacos , Neostriado/metabolismo , Neostriado/fisiopatología , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/patología , Pargilina/farmacología , Enfermedad de Parkinson/etiología , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/fisiopatología , Ratas , Ratas WistarRESUMEN
The discovery of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) leads to the hypothesis that Parkinson's disease (PD) is may be initiated or precipitated by endogenous toxins by the mechanism similar to that of MPTP in genetically-predisposed individuals. The higher cerebrospinal fluid levels of N-methylated azaheterocyclic amines, such as beta-carboline and tetrahydroisoquinoline, have been found in parkinsonian patients compared with age-matched controls. To estimate the N-methylation ability for azaheterocyclic amines in parkinsonian patient, nicotinamide was dosed with 100 mg to 26 parkinsonians and 20 controls consisted of 16 other neurogenic disease patients and 4 healthy volunteers. The urine was collected for 4 h, and then analyzed urinary its metabolites by an improved HPLC method. Nicotinamide has a pyridine ring in its structure and may be metabolized through the pathways similar to those for the endogenous neurotoxins. The urinary excretions of nicotinamide metabolites were significantly affected by aging. The excretion of N1-methylnicotinamide decreased along with aging both in PD patients and controls. In younger (65 years old or younger) PD patients, the excretion amount of N1-methylnicotinamide was significantly higher than that in younger controls. The decline rate of N1-methylnicotinamide excretion in parkinsonians was significantly greater than that in controls; the rate is more than 2-fold higher in parkinsonian patients. The age-associated decrease in 1-methyl-2-pyridone-5-carboxyamide excretion was observed only in parkinsonian patients, but not in controls. The total excreted amount of N-methylated metabolites (N1-methylnicotinamide plus 1-methyl-2-pyridone-5-carboxyamide) was also observed the age-related decline in both groups. The urinary excretions of nicotinamide and nicotinamide-N-oxide were not influenced by aging. These results would indicate that the excess N-methylation ability for azaheterocyclic amines before the onset had been implicated in PD. On the other hand, the present results suggested that the contribution of aberrant cytochrome P450 or aldehyde oxidase activity acting on the pyridine ring, that could act as detoxification routes of endogenous neurotoxins, would be small in the etiology of PD.
Asunto(s)
Encéfalo/enzimología , Carbolinas/metabolismo , Isoquinolinas/metabolismo , Niacinamida/farmacocinética , Enfermedad de Parkinson/metabolismo , Anciano , Envejecimiento/metabolismo , Aldehído Oxidasa , Aldehído Oxidorreductasas/metabolismo , Cromatografía Líquida de Alta Presión , Sistema Enzimático del Citocromo P-450/metabolismo , Femenino , Humanos , Masculino , Metilación , Persona de Mediana Edad , Niacinamida/análisis , Niacinamida/orina , Enfermedad de Parkinson/etiologíaRESUMEN
Peroxynitrite can nitrate tyrosine residues of proteins. We examined nitrotyrosine-containing proteins in cerebrospinal fluid of 66 patients with neurogenic disease by immunoblot analysis. Nitrated tyrosine residue-containing protein was observed in the cerebrospinal fluid and was concluded to be manganese superoxide dismutase (Mn-SOD). The nitrated Mn-SOD level was strikingly elevated in amyotrophic lateral sclerosis patients and was slightly increased in Alzheimer's and Parkinson's disease patients, whereas an elevated Mn-SOD level was observed only in progressive supranuclear palsy group.
Asunto(s)
Enfermedad de Alzheimer/enzimología , Nitratos/metabolismo , Nitrógeno/metabolismo , Enfermedad de Parkinson/enzimología , Superóxido Dismutasa/líquido cefalorraquídeo , Adulto , Anciano , Enfermedad de Alzheimer/líquido cefalorraquídeo , Anticuerpos , Biomarcadores , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estrés Oxidativo/fisiología , Enfermedad de Parkinson/líquido cefalorraquídeo , Pruebas de Precipitina , Tirosina/análogos & derivados , Tirosina/análisis , Tirosina/inmunología , Tirosina/metabolismoRESUMEN
Aeromonas sp. B-5, which has the ability to decolorize azo dyes, was isolated from soil. Aeromonas sp. B-5 completely decolorized 100 mg/l of Bordeaux S by reductive cleavage of azo bonds under static conditions in 24 h. Though the decolorization of Bordeaux S by Aeromonas sp. B-5 was suppressed under shaking, rapid decolorization was observed when the culture was changed to static conditions after cultivation with shaking. The indigoid dye, Acid blue 74, was decolorized by Aeromonas sp. B-5 under shaking conditions, in contrast to the decolorization of azo dyes.
RESUMEN
BACKGROUND: Various prognostic markers for lung carcinoma have been proposed, but to the authors' knowledge none is noninvasive and convenient for clinical use. The current study examined the utility of several radiotracers for the prediction of multidrug resistance (MDR) and radioresistance in patients with lung carcinoma. METHODS: Thirty patients with untreated lung carcinoma underwent a dual isotope single photon emission computed tomography (SPECT) scan at 10 minutes and 120 minutes after the injection of technetium-99m ((99m)Tc)-tetrofosmin ((99m)Tc-TF) (370 megabecquerels [MBq]) and thallium-201 ((201)TlCl) (111 MBq). Retention of each tracer was evaluated semiquantitatively. Using radiation and chemotherapy (cisplatin plus etoposide), the patients either were treated sequentially (n = 12) or concurrently (n = 18). The relation between therapeutic response and retention of each tracer was analyzed. The detectability of radioresistance was examined. RESULTS: In patients treated with sequential therapy, the response to radiation was predicted by (99m)Tc-TF retention, whereas (201)Tl retention was found not to be predictive. Regardless of whether the sequential or concurrent protocol was applied, 14 of 18 tumors with high (99m)Tc-TF retention (>/= 15%) exhibited a favorable response to chemoradiotherapy whereas all 12 tumors with low (99m)Tc-TF retention (= 15%) did not respond to the therapy. In contrast, (201)Tl retention was not found to be a predictive factor. CONCLUSIONS: The employed SPECT method is a useful tool for the in vivo prediction of radioresistance, P-glycoprotein (P-gp), and non-P-gp MDR in lung carcinoma. Low (99m)Tc-TF retention serves as a strong predictor of therapeutic resistance. High (99m)Tc-TF retention implies a favorable response. (201)Tl did not appear to be a predictive factor but is required for localization of the lesion on SPECT imaging.
Asunto(s)
Carcinoma de Células Pequeñas/diagnóstico por imagen , Resistencia a Múltiples Medicamentos , Neoplasias Pulmonares/diagnóstico por imagen , Tolerancia a Radiación , Tomografía Computarizada de Emisión de Fotón Único , Anciano , Antineoplásicos/uso terapéutico , Carcinoma de Células Pequeñas/terapia , Cisplatino/uso terapéutico , Terapia Combinada , Quimioterapia , Femenino , Humanos , Cinética , Neoplasias Pulmonares/terapia , Masculino , Compuestos Organofosforados , Compuestos de Organotecnecio , Pronóstico , Radioterapia , Radioisótopos de Talio , Resultado del TratamientoRESUMEN
Owing to recent advances in imaging technology and radiologic intervention, survival rates in patients with hepatocellular carcinoma have improved markedly. However, such prolonged survival has resulted in an increase in extrahepatic metastases. Tc-99m (Sn)-N-pyridoxyl-5-methyltryptophan (Tc-99m PMT), developed for hepatobiliary scintigraphy, has been used to visualize extrahepatic metastases, with most related reports limited to osseous metastases. The authors report two cases of hepatocellular cancer presenting as a hypopharyngeal metastasis and intraperitoneal dissemination along the tract of a fine-needle biopsy. Lesions undetectable on planar imaging could be visualized by Tc-99m PMT SPECT.
Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/secundario , Neoplasias Hepáticas/patología , Compuestos de Organotecnecio , Piridoxal/análogos & derivados , Radiofármacos , Tomografía Computarizada de Emisión de Fotón Único , Triptófano/análogos & derivados , Anciano , Humanos , Neoplasias Hipofaríngeas/diagnóstico por imagen , Neoplasias Hipofaríngeas/secundario , Masculino , Siembra Neoplásica , Neoplasias Peritoneales/diagnóstico por imagen , Neoplasias Peritoneales/secundarioRESUMEN
BACKGROUND: Adenoid cystic carcinoma is a slow-growing malignant tumor occurring in the head and neck. Intracranial involvement usually results from direct skull invasion from adjacent primary sites. To our knowledge, this is the first reported case of multiple brain parenchymal metastases manifesting with hemorrhage. CASE DESCRIPTION: A 60-year-old male experienced sudden onset of hemiparesis caused by an intracerebral hematoma in a brain metastasis from adenoid cystic carcinoma. The primary parotid tumor was treated 15 months before the appearance of the brain metastases. The hemorrhagic metastasis was resected, and cranial irradiation was performed. The brain metastasis had increased cellular atypism compared with the primary tumor. The patient remained well and free of neurologic dysfunctions until 5 months after the radiotherapy was completed; he died of systemically advanced disease 8 months after the craniotomy. CONCLUSION: Hematogeneous brain metastases of adenoid cystic carcinoma are quite rare and cannot be distinguished from those of other cancers radiologically. We assume that the intratumoral hemorrhage is related to the tendency of the tumor to spread around the vessels. Although radiation therapy is not curative, it is beneficial in controlling tumor regrowth.
Asunto(s)
Neoplasias Encefálicas/secundario , Carcinoma Adenoide Quístico/secundario , Neoplasias de la Parótida/patología , Bacteriemia/etiología , Bacteriemia/microbiología , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirugía , Carcinoma Adenoide Quístico/radioterapia , Carcinoma Adenoide Quístico/cirugía , Terapia Combinada , Resultado Fatal , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neoplasias Primarias Secundarias/patología , Neoplasias Primarias Secundarias/radioterapia , Neoplasias Primarias Secundarias/cirugía , Neoplasias de la Parótida/radioterapia , Neoplasias de la Parótida/cirugía , Úlcera por Presión/etiología , Úlcera por Presión/microbiología , Neoplasias de la Columna Vertebral/complicaciones , Neoplasias de la Columna Vertebral/secundario , Infecciones Estafilocócicas/microbiologíaRESUMEN
Formerly, patients with subareolar breast cancers have not been good candidates for breast-conservation treatment (BCT) in Japan. However, recently it was reported that patients with subareolar cancers were good candidates for this treatment. In order to improve both cosmetic results and survival rates, we performed BCT for 27 patients with subareolar breast cancers following pre-operative CAF chemotherapy and tamoxifen administration. From August 1989 to June 1998, we performed BCT for 200 out of 206 patients who visited our hospital with the desire of breast-conservation. Of these patients, 27 presented with tumors within 2 cm of the nipple areolar complex. For 26 of these 27 patients, breast-conserving surgery was performed following two to four times of CAF chemotherapy, and another one patient did not undertake any surgical resection. Following the surgery, patients were treated with radiation therapy to the intact breast and ipsilateral axilla to a total dose of 4,400 cGy with electron conedown to a total dose of 5,300 cGy. Their primary tumors were at T4bN0 in 1 case, T2N1b in 5 cases, T2N0 in 18 cases, and T1cN0 in 3 cases. Tamoxifen was administered to all the patients. CAF chemotherapy was performed six times for stage I patients, and eight times for stage II patients in total. For one patient with direct tumor invasion to the nipple, intraarterial infusion chemotherapy was performed following radiation therapy and CAF chemotherapy, without any surgical resection. For another 26 patients, breast-conserving surgery was performed, and 5 of them underwent lumpectomy under local anesthesia on an outpatient basis. For these 26 patients, the microscopic surgical margin was positive for 8 patients, close for 6 patients, negative for 10 patients, and unknown for 2 patients. All patients are alive with no evidence of disease after a follow-up of approximately 47 months on average, and all of their cosmetic results are estimated as excellent or good. It is concluded that BCT intensified with preoperative CAF chemotherapy and tamoxifen for subareolar breast cancers is a satisfying treatment modality in terms of both cosmetic results and survival rates.
Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Mastectomía Segmentaria , Tamoxifeno/uso terapéutico , Adulto , Anciano , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Terapia Combinada , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Persona de Mediana Edad , Pezones , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
We have evaluated the neuronal uptake of 12 neutral and quaternary azaheterocyclic amines that are possible candidates for idiopathic Parkinson's disease via dopamine transporter of striatal synaptosomes. The double-reciprocal plots for dopamine transporter obtained from Wistar rat and C57BL/6 mouse synaptosomes with N-methyl-4-phenylpyridinium cation (MPP+) as a substrate were identical to each other. Neutral beta-carbolines and tetrahydroisoquinolines were unfavorable substrates for dopamine transporter. The quarternization of these compounds strikingly increased the affinity for dopamine transporter with 2-10 times greater Km and 10 times smaller Vmax values than MPP+. Although catechol tetrahydroisoquinolines were weak substrates, their quarternization reduced their original properties as substrates for dopamine transporter. These results provide both topographic and electrogenic information of azaheterocyclic amines for the dopamine transporter-mediated influx. The intramolecular distance between the N-atom and the centroid of the benzene ring could be an important factor for the recognition of binding site of dopamine transporter, and an adequate net charge similar to dopamine would be further required for translocation into the cells.
Asunto(s)
1-Metil-4-fenilpiridinio/farmacología , Proteínas Portadoras/metabolismo , Dopaminérgicos/farmacología , Dopamina/metabolismo , Compuestos Heterocíclicos/farmacología , Glicoproteínas de Membrana , Proteínas de Transporte de Membrana , Neostriado/metabolismo , Proteínas del Tejido Nervioso , Enfermedad de Parkinson Secundaria/inducido químicamente , Sinaptosomas/metabolismo , 1-Metil-4-fenilpiridinio/metabolismo , Animales , Proteínas Portadoras/efectos de los fármacos , Dopaminérgicos/metabolismo , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Técnicas In Vitro , Cinética , Masculino , Ratones , Ratones Endogámicos C57BL , Neostriado/efectos de los fármacos , Neurotoxinas/metabolismo , Ratas , Ratas Wistar , Especificidad de la Especie , Sinaptosomas/efectos de los fármacosRESUMEN
Microrecordings were performed during pallidotomy and thalamotomy for Parkinson's disease (PD). Neuronal activity in globus pallidus (GP) was in general agreement with previous studies of human and primate models of PD. Neuronal activity, where frequency of tremor appeared to oscillate independently from peripheral input, was encountered in GPi. In contrast, neuronal activity in Vim regarding frequency of firing also correlated with tremor and was passively driven by kinesthetic stimuli with a somatotopic arrangement. Pallidal lesions based on microrecording induced relative reductions of tremor, while small Vim lesions immediately alleviated tremor. Basal ganglia pathology due to dopamine depletion could generate oscillatory neuronal activity in GPi, which may cause tremor. However, peripheral feedback to the motor cortex via Vim is also significant for tremorgenesis, because Vim may be an excitatory driving source for motor cortical neurons. Thus, a Vim lesion could reduce excitability of the motor cortical neurons and abolish tremor.
Asunto(s)
Globo Pálido/fisiopatología , Neuronas/fisiología , Enfermedad de Parkinson/fisiopatología , Enfermedad de Parkinson/cirugía , Núcleos Talámicos/fisiopatología , Electromiografía , Electrofisiología , Globo Pálido/patología , Humanos , Enfermedad de Parkinson/patología , Núcleos Talámicos/patología , Resultado del Tratamiento , Temblor/patología , Temblor/fisiopatologíaRESUMEN
The effects of dilazep and K-7259, a dilazep derivative, on the haemolysis (as evidenced by release of haemoglobin) induced by palmitoyl-L-carnitine (PAL-CAR) or palmitoyl 1-alpha-lysophosphatidylcholine (PAL-LPC) have been determined in rat erythrocytes. At concentrations above the critical micelle concentration both PAL-CAR and PAL-LPC induced haemolysis; the concentrations of PAL-CAR and PAL-LPC producing 50% haemolysis were approximately 13 and 14 microM, respectively. The 50% haemolysis induced by PAL-CAR or PAL-LPC was attenuated by dilazep (1, 10 or 100 microM) but not at the highest concentration used (1 mM). K-7259 attenuated the 50% haemolysis induced by PAL-CAR or PAL-LPC at concentrations ranging from 1 microM to 1 mM. Similarly, dilazep (1 to 100 microM) and K-7259 (1 microM to 1 mM) significantly or insignificantly attenuated the 25% and 75% haemolysis induced by PAL-CAR or PAL-LPC. Neither dilazep nor K-7259 affected micelle formation by PAL-CAR or PAL-LPC, nor, at concentrations of 1 and 10 microM, did they attenuate the haemolysis induced by osmotic imbalance (hypotonic haemolysis). These results suggest that both dilazep and K-7259 protect the erythrocyte membrane from the damage induced by PAL-CAR or PAL-LPC. The protective effects of dilazep and K-7259 are mediated by some mechanism other than prevention of micelle formation or protection of the erythrocyte membrane against osmotic imbalance.
Asunto(s)
Dilazep/análogos & derivados , Dilazep/farmacología , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Lisofosfatidilcolinas/toxicidad , Palmitoilcarnitina/toxicidad , Vasodilatadores/farmacología , Animales , Soluciones Hipotónicas , Masculino , Micelas , Ratas , Ratas Sprague-DawleyRESUMEN
We studied the effects of nifedipine (NF) on UV-induced photohemolysis of erythrocytes in vitro. A suspension in physiologic saline of crythrocytes separated from the venous blood sample freshly obtained from a dog was prepared and used. NF is a photolabile agent, and this drug was extremely sensitive to the long wavelength (365 nm) of UV light. The most abundant photodegradation product was a nitroso-derivative which changed into a lactam-derivative in the dog erythrocyte suspension with or without irradiation. NF itself showed protective effects against photohemolysis of erythrocytes caused by 365 nm of UV light as well as hypotonic hemolysis. But NF enhanced the degree of photohemolysis under oxygen condition. The photohemolysis enhanced by NF was reduced by thiobarbituric acid, indicating an oxidative stress by a radical intermediate of NF to photohemolysis. On the other hand, the nitroso-derivative reacted with erythrocyte hemoglobin spectroscopically to change into the lactam-derivative. It is considered that NF is a phototoxic agent to cause photohemolysis by producing a radical intermediate with oxygen and unknown species of hemoglobin degraded with the nitroso-derivative of nifedipine photoproduct.
Asunto(s)
Bloqueadores de los Canales de Calcio/efectos adversos , Membrana Eritrocítica/efectos de los fármacos , Hemólisis/efectos de los fármacos , Hemólisis/efectos de la radiación , Nifedipino/efectos adversos , Animales , Células Cultivadas , Dermatitis Fototóxica/etiología , Perros , Rayos Ultravioleta/efectos adversosRESUMEN
A 30-year-old male presented with a large calcified intraventricular mass. The tumor was completely resected via the transventricular route. Light microscopy showed the tumor was composed of small round cells with perinuclear halo, typical of oligodendroglioma. Electron microscopy revealed marked neuronal differentiation, including neurosecretory granules, well-formed numerous synapses, and lipofuscin granules. The tumor was diagnosed as well-differentiated central neurocytoma.
Asunto(s)
Neoplasias del Ventrículo Cerebral/patología , Ventrículos Cerebrales/patología , Lipofuscina/química , Neurocitoma/patología , Adulto , Neoplasias del Ventrículo Cerebral/cirugía , Ventrículos Cerebrales/cirugía , Citoplasma/ultraestructura , Humanos , Lisosomas/ultraestructura , Masculino , Neurocitoma/cirugíaRESUMEN
Effects of four photodegradation products of nifedipine (nitroso-, nitro-, azoxy- and N,N'-dioxide-derivatives) were studied in the rat aortic strip suspended in the bath medium. In the CaCl2-free bath medium containing 40 mM KCl, CaCl2 (2.5 mM) induced contraction, which was relaxed by nifedipine (-log [EC50] = 8.66 M) and all the four photodegradation products (-log[EC50] = 4.15-4.82 M). The EC50 values for all these substances were not affected by denuding the vessel of endothelium. In the bath medium containing KCl (15 mM), Bay K-8644 (2 x 10(-6) M) induced contraction, which was relaxed by nifedipine (10(-9)-10(-6) M) and its four photodegradation products (3 x 10(-6)-10(-4) M). Norepinephrine (10(-7) M) induced contraction, which was relaxed by the nitroso-derivative (10(-4) M) noncompetitively (pIC50 = 4.37) but not by three other photodegradation products. Both methylene blue and hemoglobin had no effect on the relaxation produced by the nitroso-derivative. Phorbol 12-myristate 13-acetate induced contraction, which was inhibited completely by the nitroso-derivative (10(-4) M) but only by 42% by nifedipine (10(-4) M). Prostaglandin F2 alpha (3 x 10(-6) M), endothelin-1 (10(-9) M) and 5-hydroxytryptamine (10(-6) M) also induced contraction, which was relaxed effectively by the nitroso-derivative (10(-4) M) but not by any of the three other photodegradation products.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Aorta/efectos de los fármacos , Nifedipino/análogos & derivados , Vasodilatadores/farmacología , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Alcaloides/farmacología , Animales , Cloruro de Calcio/farmacología , Dinoprost/farmacología , Endotelinas/farmacología , Hemoglobinas/farmacología , Masculino , Azul de Metileno/farmacología , Nifedipino/farmacología , Compuestos Nitrosos/farmacología , Norepinefrina/farmacología , Fotoquímica , Potasio/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Ratas , Ratas Sprague-Dawley , Serotonina/farmacología , Estaurosporina , Acetato de Tetradecanoilforbol/farmacología , Vasoconstrictores/farmacologíaRESUMEN
PET imaging studies with 4-[18F]fluoro-L-m-tyrosine (FMT) in normal macaca monkeys showed selective accumulations of radioactivity in the striatum with time. In monkeys rendered hemiparkinsonian by intracarotid infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), FMT uptake was eliminated in the lesioned striatum. FMT-PET studies were able to detect dopaminergic terminals in both normal and hemiparkinsonian monkeys, and clearly showed a reduction in aromatic L-amino acid decarboxylase (AAAD) activities in the MPTP-lesioned striatum. These results show that FMT is promising as a PET tracer for the evaluation of central dopaminergic systems in parkinsonism.
Asunto(s)
Cuerpo Estriado/diagnóstico por imagen , Radioisótopos de Flúor , Enfermedad de Parkinson Secundaria/diagnóstico por imagen , Tirosina/análogos & derivados , 1-Metil-4-fenil-1,2,3,6-Tetrahidropiridina , Animales , Estimulantes del Sistema Nervioso Central/farmacocinética , Cuerpo Estriado/metabolismo , Radioisótopos de Flúor/farmacocinética , Macaca , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/metabolismo , Valores de Referencia , Tomografía Computarizada de Emisión/métodos , Tirosina/farmacocinéticaRESUMEN
We constructed the broad-host-range human epidermal growth factor (EGF) secretion plasmid pKSEGF2 by inserting the Escherichia coli tac promoter, the signal sequence of Pseudomonas stutzeri amylase, and the synthesized EGF gene into the broad-host-range vector pKT230. E. coli JM109 carrying pKSEGF2 secreted EGF into the periplasm and the culture medium under the control of the tac promoter. Pseudomonas aeruginosa PAO1161 carrying pKSEGF2 and Pseudomonas putida AC10 carrying pKSEGF2 secreted EGF into the culture medium constitutively. Four hydrogen-utilizing bacteria, Pseudomonas pseudoflava, Alcaligenes eutrophus, Alcaligenes paradoxus, and Paracoccus denitrificans, were transconjugated with pKSEGF2 from eight hydrogen-utilizing bacteria tested. In these transconjugated hydrogen-utilizing bacteria, P. pseudoflava carrying pKSEGF2 grew autotrophically and secreted EGF, confirmed by Western blot (immunoblot) analysis, into the culture medium constitutively.