RESUMO
The use of biodegradable particles as oral delivery vehicles for macromolecular drugs was investigated. We evaluated the binding, uptake and absorption of poly-dl-lactide (PLA) micro- and nanoparticles in Caco-2 monolayers and in ileal tissue and gut associated lymphoid tissue (GALT) of anaesthetised rats and rabbits. Using a range of experimental techniques, we found that approximately 10% of administered micro- and nanoparticles were adsorbed to the apical membranes of each of the five intestinal models. Nanoparticles were found to be absorbed better than microparticles. Overall, little discrimination in uptake patterns was evident between Peyer's patch (PP) and non-PP tissue while rat ileum showed a greater uptake capacity than rabbit. Our results show that uptake of PLA particles was low capacity, size-dependent and predominantly transcellular in all systems. A low proportion of the apically-bound particles was absorbed, with uptake exclusion evident for particles >4microm. The affinity of PLA particles for intestinal epithelia and GALT needs to be greatly enhanced in order to achieve improved oral bioavailability of macromolecules.
Assuntos
Íleo/metabolismo , Poliésteres/metabolismo , Animais , Células CACO-2 , Portadores de Fármacos , Ferritinas/análise , Fluoresceína/análise , Humanos , Íleo/ultraestrutura , Tecido Linfoide/metabolismo , Microscopia Confocal , Poliésteres/química , Coelhos , Ratos , Ratos WistarAssuntos
Interleucina-1/farmacologia , Interleucina-6/biossíntese , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/imunologia , Membrana Celular/fisiologia , Técnicas de Cultura/instrumentação , Técnicas de Cultura/métodos , Endotélio , Epitélio , Humanos , Interleucina-6/metabolismo , Células Tumorais CultivadasRESUMO
With the single-channel patch-clamp technique we have identified Ca2+-sensitive, high-conductance (maxi) K+ channels in the basolateral membrane (BLM) of exocrine gland cells in frog skin. Under resting conditions, maxi K+ channels were normally quiescent, but they were activated by muscarinic agonists or by high serosal K+. In excised inside-out patches and with symmetrical 140mmol/l K+, single-channel conductance was 200pS and the channel exhibited a high selectivity for K+ over Na+. Depolarization of the BLM increased maxi K+ channel activity. Increasing cytosolic free Ca2+ (by addition of 100nmol/l thapsigargin to the bathing solution of cell-attached patches also increased channel activity, whereas thapsigargin had no effect when added to excised inside-out patches. An increase in cytosolic free Ca2+ directly activated channel activity in a voltage-dependent manner. Maxi K+ channel activity was sensitive to changes in intracellular pH, with maximal activity at pH 7.4 and decreasing activities following acidification and alkalinization. Maxi K+ channel outward current was reversibly blocked by micromolar concentrations of Ba2+ from the cytosolic and extracellular site, and was irreversibly blocked by micromolar concentrations of charybdotoxin and kaliotoxin from the extracellular site in outside-out patches.
Assuntos
Cálcio/fisiologia , Glândulas Exócrinas/metabolismo , Canais de Potássio/metabolismo , Pele/metabolismo , Animais , Bário/farmacologia , Citosol/efeitos dos fármacos , Citosol/metabolismo , Inibidores Enzimáticos/farmacologia , Glândulas Exócrinas/citologia , Glândulas Exócrinas/efeitos dos fármacos , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Ativação do Canal Iônico/efeitos dos fármacos , Ativação do Canal Iônico/fisiologia , Canais de Potássio/efeitos dos fármacos , Rana esculenta , Pele/citologia , Pele/efeitos dos fármacos , Terpenos/farmacologia , TapsigarginaRESUMO
We have previously mapped the human azoospermia factor to a deletion in Y chromosome interval 6 (subinterval XII-XIV). We now report the isolation and characterization of a gene family located within this deletion. Analysis of the predicted protein products suggests a possible role in RNA processing or translational control during early spermatogenesis. The Y chromosome RNA recognition motif (YRRM) family includes a minimum of three members expressed specifically in the testis. Interphase in situ results and Southern blot analysis indicate that several further YRRM sequences map within interval 6. Several mammalian species show Y chromosome conservation of YRRM sequences. We have detected deletions of YRRM sequences in two oligospermic patients with no previously detectable mutation.
Assuntos
Oligospermia/genética , Proteínas de Ligação a RNA/genética , Espermatogênese , Cromossomo Y , Sequência de Aminoácidos , Sequência de Bases , Mapeamento Cromossômico , Expressão Gênica , Genes , Humanos , Masculino , Dados de Sequência Molecular , Família Multigênica , Oligodesoxirribonucleotídeos/química , RNA Mensageiro/genética , Sequências Repetitivas de Ácido Nucleico , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Testículo/fisiologiaAssuntos
Anticorpos Monoclonais , Antígenos Glicosídicos Associados a Tumores/análise , Radioisótopos de Índio , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/tratamento farmacológico , Feminino , Humanos , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/diagnóstico , Tomografia Computadorizada de EmissãoRESUMO
We previously described a system for the in vitro immunization of human tonsilar lymphocytes under serum-free conditions in the presence of muramyl dipeptide and rIL-2 (1). Further studies with this system reveal possible roles for PWM and rIL-6 in the immunization process. The addition of these factors led to an increase in the levels of antibody produced in lymphocyte cultures. The time of addition of these factors was found to be important in determining the extent of their effects on the overall yields of antigen-reactive cells.
Assuntos
Linfócitos B/imunologia , Imunização/métodos , Interleucina-6/farmacologia , Tonsila Palatina/citologia , Mitógenos de Phytolacca americana/farmacologia , Acetilmuramil-Alanil-Isoglutamina/farmacologia , Formação de Anticorpos , Linfócitos B/efeitos dos fármacos , Células Cultivadas , Conalbumina/imunologia , Humanos , Ativação Linfocitária/efeitos dos fármacos , Cooperação Linfocítica , Ovalbumina/imunologia , Proteínas Recombinantes/farmacologia , Subpopulações de Linfócitos T/imunologiaRESUMO
The effects of haematoporphyrin (Hp), haematoporphyrin derivative (HpD), coumarin, 7-hydroxycoumarin, 4-hydroxycoumarin, amino-methyl-coumarin acetic acid and acridine orange, with and without photoradiation, on Landschutz ascites tumour (LAT) cells were examined. Hp, HpD and acridine orange showed a significant effect on LAT cell viability following photoradiation. However, coumarin or its derivatives had no significant effect on LAT cell viability, with or without photoradiation, over 18 h. Coumarin alone had a significant effect on viability of LAT cells, in vitro, over a period of 9 days. This effect was verified by transplantability studies. Coumarin and 7-hydroxycoumarin both exhibited cytostatic effects on LAT cell growth.
Assuntos
Laranja de Acridina/farmacologia , Antineoplásicos , Cumarínicos/farmacologia , Hematoporfirinas/farmacologia , Luz , Células Tumorais Cultivadas/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Feminino , Camundongos , Transplante de Neoplasias , Neoplasias/tratamento farmacológico , Fotoquimioterapia , Relação Estrutura-AtividadeRESUMO
A method for the in vitro immunization of human tonsilar lymphocytes is described. This method allows for the sensitization of B-cells against various antigens under serum-free medium conditions. The medium is supplemented with defined concentrations of antigen, rIL-2 and muramyl dipeptide to boost the immune responses. This method may prove useful for the generation of antigen reactive B-cells for use in human monoclonal antibody production and the study of the effects of other lymphokines on the in vitro immune response.
Assuntos
Acetilmuramil-Alanil-Isoglutamina/farmacologia , Anticorpos Monoclonais/biossíntese , Interleucina-2/farmacologia , Linfócitos/imunologia , Antígenos/administração & dosagem , Meios de Cultura , Humanos , Imunização , Técnicas In Vitro , Tonsila Palatina/imunologia , Linfócitos T/imunologia , Fatores de TempoAssuntos
Cumarínicos , Animais , Cumarínicos/análise , Cumarínicos/metabolismo , Cumarínicos/farmacologia , HumanosRESUMO
The onset and persistence of changes in 3H-spiroperidol binding to dopamine (DA) D2 receptors were examined in rat mesolimbic and striatal brain regions following daily administration of haloperidol, molindone, or sulpiride for 3, 7, 14, or 28 days. Neuroleptic dose equivalencies were determined by inhibition of 3H-spiroperidol in vivo binding in several rat brain regions. Changes in locomotor and stereotyped responses to the specific DA D2 agonist quinpirole were examined 3 days after the last treatment dose. Haloperidol or molindone administration increased mean stereotypy scores and striatal DA D2 receptor densities throughout the 28-day treatment period. In contrast, mesolimbic DA D2 receptor densities were transiently increased and returned to control values, after 28 days of haloperidol or molindone treatment. Sulpiride treatment increased mean stereotypy scores and striatal Bmax values, but had no effect on locomotion or mesolimbic dopamine receptor density. Additionally, the magnitude of change in the various measures of brain DA function varied among the three neuroleptic treatment groups. Results from this study suggest that mesolimbic and striatal brain regions differ in their response to long-term neuroleptic administration and that drug choice may influence the magnitude of neuroleptic-induced dopaminergic supersensitivity.
Assuntos
Haloperidol/farmacologia , Indóis/farmacologia , Molindona/farmacologia , Receptores Dopaminérgicos/efeitos dos fármacos , Sulpirida/farmacologia , Animais , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Haloperidol/metabolismo , Técnicas In Vitro , Sistema Límbico/efeitos dos fármacos , Sistema Límbico/metabolismo , Masculino , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Comportamento Estereotipado/efeitos dos fármacosRESUMO
Kindled seizures developed in rats following repeated electrical stimulation of the left CA1 region of the hippocampus. Two weeks after the final kindled seizure, the densities of dopamine (DA) D2 receptors were assayed in the left and right amygdaloid area, nucleus accumbens, and nucleus caudatus. A significant increase (107%) in the density of DA D2-receptors in the ipsilateral nucleus accumbens occurred. This finding may help to define the long-term neurochemical consequences of kindling.
Assuntos
Hipocampo/fisiologia , Excitação Neurológica , Sistema Límbico/metabolismo , Receptores Dopaminérgicos/metabolismo , Animais , Estimulação Elétrica , Masculino , Tratos Piramidais/fisiologia , Ratos , Ratos Endogâmicos , Receptores de Dopamina D2 , Valores de ReferênciaRESUMO
Regional differences in the onset and persistence of increased dopamine D2 receptor density in rat brain were studied following daily injections of haloperidol for 3, 7, 14, or 28 days. Striatal [3H]-spiroperidol Bmax values were significantly increased following 3-28 days of haloperidol treatment, as compared to saline controls. Olfactory tubercle Bmax values were significantly increased only after 14 or 28 days of haloperidol treatment. Nucleus accumbens Bmax values were significantly increased only in the 14-day drug treatment group, suggesting that dopamine D2 receptor up-regulation in nucleus accumbens may reverse during ongoing neuroleptic treatment. These findings suggest that important differences in adaptive responses to chronic dopamine blockade may exist between dopaminergic synapses located in various rat brain regions.
Assuntos
Corpo Estriado/efeitos dos fármacos , Haloperidol/farmacologia , Sistema Límbico/efeitos dos fármacos , Receptores Dopaminérgicos/metabolismo , Animais , Antipsicóticos/farmacologia , Corpo Estriado/metabolismo , Sistema Límbico/metabolismo , Masculino , Núcleo Accumbens/metabolismo , Ratos , Ratos Endogâmicos , Espiperona/metabolismoRESUMO
To determine whether depression and neuroleptic-induced parkinsonism confound the clinical assessment of negative symptoms in schizophrenics, we evaluated 45 outpatient schizophrenics for depression, parkinsonian symptoms, and negative symptoms using standard clinical rating scales. Neuroleptic and anticholinergic dose and plasma activity were also determined. Associations between negative symptoms and these clinical and drug variables were examined using a multivariate statistical model. Negative symptoms were significantly correlated with several parkinsonian symptoms, some vegetative features of depression, and with anticholinergic dose. No significant correlations were found between negative symptoms and cognitive features of depression, or neuroleptic and anticholinergic plasma activity. These findings suggest that assessment criteria for negative symptoms, depression, and drug-induced parkinsonism overlap in treated schizophrenics. Strategies for differentiating these clinical syndromes are discussed.
Assuntos
Antipsicóticos/efeitos adversos , Transtorno Depressivo/diagnóstico , Doença de Parkinson Secundária/induzido quimicamente , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Adulto , Idoso , Assistência Ambulatorial , Antipsicóticos/sangue , Antipsicóticos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Parassimpatolíticos/efeitos adversos , Parassimpatolíticos/sangue , Parassimpatolíticos/uso terapêutico , Doença de Parkinson Secundária/diagnóstico , Doença de Parkinson Secundária/tratamento farmacológico , Escalas de Graduação Psiquiátrica , Esquizofrenia/tratamento farmacológicoRESUMO
To determine whether there is an association between prolactin (PRL) levels and psychopathology or tardive dyskinesia during neuroleptic treatment, we measured plasma prolactin levels and neuroleptic activity (NA) in 33 chronically treated male schizophrenics. Neuroleptic dose, plasma NA, and PRL were significantly intercorrelated. Plasma PRL levels were also measured in 8 male schizophrenics recently withdrawn from neuroleptics and in 18 normal male controls. In treated patients, but not in controls, PRL levels decreased with age and duration of illness, two variables that we interpreted as indirect measures of neuroleptic exposure. PRL levels in patients recently withdrawn from neuroleptics were lower than in treated patients or controls, which was suggestive of rebound hypoprolactinemia. A prolactin index, calculated as the ratio of PRL levels to NA, was inversely correlated with paranoid symptoms and tardive dyskinesia in younger treated patients. These results lead to speculation that tuberoinfundibular dopaminergic supersensitivity develops in chronically treated schizophrenics and that it is associated with nigrostriatal supersensitivity, manifested by tardive dyskinesia, and paranoid symptoms, which may reflect mesolimbic supersensitivity.
Assuntos
Antipsicóticos/efeitos adversos , Discinesia Induzida por Medicamentos/sangue , Prolactina/sangue , Esquizofrenia Paranoide/tratamento farmacológico , Adulto , Idoso , Assistência Ambulatorial , Antipsicóticos/sangue , Hospitais Psiquiátricos , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Receptores Dopaminérgicos/efeitos dos fármacos , Esquizofrenia Paranoide/sangue , Esquizofrenia Paranoide/psicologiaAssuntos
Antipsicóticos/efeitos adversos , Discinesia Induzida por Medicamentos/etiologia , Transtornos Paranoides/psicologia , Prolactina/sangue , Receptores Dopaminérgicos/fisiologia , Esquizofrenia/tratamento farmacológico , Humanos , Masculino , Transtornos Paranoides/diagnóstico , Transtornos Paranoides/fisiopatologia , Escalas de Graduação Psiquiátrica , Receptores Dopaminérgicos/efeitos dos fármacos , Esquizofrenia/sangue , Esquizofrenia/fisiopatologiaRESUMO
In the Cardiff Family Planning Association Clinic 330 men have been sterilized during the past 20 months. Selection for operation was made after a detailed discussion between husband, wife, and a Family Planning Association doctor, and with the general practitioner's agreement. The outpatient operation was performed under local anaesthetic by a surgeon. It was regarded as being successful or complete when two semen analyses showed azoospermia at an interval of one month.