RESUMO
BACKGROUND: Research mostly conducted in the UK and northern Europe has established that there are high rates of first-episode psychosis (FEP) in large cities and immigrant populations; moreover, psychosis has been found to be associated with cannabis use and early trauma. The present study aimed to evaluate the incidence rate of FEP and the distribution of several risk factors (e.g. age, ethnicity, substance abuse) in Bologna, Italy. METHOD: The Bologna FEP (BoFEP) study is an 8-year prospective study. All FEP patients, 18-64 years old, consecutively referred to the West Bologna Community Mental Health Centre (CMHC) from 2002 to 2009 were evaluated. Sociodemographic information, migration history and clinical data were collected through an ad-hoc schedule. Psychiatric diagnoses were recorded using the Schedule for Clinical Assessment of Neuropsychiatry (SCAN). RESULTS: The overall incidence rate (IR) in the BoFEP study was 16.4 per 100 000 person-years [95% confidence interval (CI) 13.9-18.9]. The incidence was higher in young people, men and migrants (MI). CONCLUSIONS: The IR of FEP found by the Bologna study is lower than that found by other European studies. However, as in other studies, the incidence was higher in certain groups. This heterogeneity has implications for policy and mental health service development, and for understanding the aetiology of psychosis.
Assuntos
Transtornos Psicóticos/epidemiologia , Esquizofrenia/epidemiologia , População Urbana/estatística & dados numéricos , Adolescente , Adulto , Centros Comunitários de Saúde Mental/estatística & dados numéricos , Feminino , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Adulto JovemRESUMO
Trimethyltin-induced intoxication has a great impact on human health due to the widespread occurrence of methyltin compounds. Acute TMT intoxication in humans leads to a variety of neurological symptoms which involve primarily the limbic system. In the present review we summarized the neuromorphological correlates of this neurological syndrome extending the analysis to various extra-limbic regions and detailing the fine ultrastructure of TMT-induced neuronal alterations. In order to comprehend the pathophysiology of TMT-induced neuronal damage we analysed the various experimental models of TMT-induced neurotoxicity. When comparing various animal species, it seems that the variety of neuropathological correlates are not related to species difference in the sensitivity to TMT toxicity but to a different susceptibility to secondary effects produced by TMT. In fact, apart from a primary neurotoxic damage induced by TMT at neuronal level, this compound promotes the onset of limbic and generalized seizures, which in turn add a secondary damage to that induced immediately by TMT. Thus, the different neuropathology observed in different animal species is produced mainly by a different sensitivity to epilepsy-induced brain damage.
Assuntos
Comportamento Animal/efeitos dos fármacos , Modelos Animais de Doenças , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/patologia , Neurotoxinas/toxicidade , Compostos de Trimetilestanho/toxicidade , Animais , Humanos , Sistema Límbico/patologia , RoedoresRESUMO
Methamphetamine produces locomotor activation and typical stereotyped motor patterns, which are commonly related with increased catecholamine activity within the basal ganglia, including the dorsal and ventral striatum. Since the cerebellum is critical for movement control, and for learning of motor patterns, we hypothesized that cerebellar catecholamines might be a target of methamphetamine. To test this experimental hypothesis we injected methamphetamine into C57 Black mice at the doses of 5 mg/kg two or three times, 2 h apart. This dosing regimen is known to be toxic for striatal dopamine terminals. However, we found that in the cerebellum, methamphetamine increased the expression of the primary transcript of the tyrosine hydroxylase (TH) gene, followed by an increased expression of the TH protein. Increased TH was localized within Purkinje cells, where methamphetamine increased the number of TH-immunogold particles, and produced a change in the distribution of the enzyme by increasing the cytoplasmic percentage. Increased TH expression was accompanied by a slight increase in noradrenaline content. This effect was highly site-specific for the cortex of posterior vermal lobules, while only slight effects were detectable in the hemispheres. The present data indicate that the cerebellum does represent a target of methamphetamine, which produces specific and fine alterations of the catecholamine system involving synthesis, amount, and compartmentalization of TH as well as increased noradrenaline levels. This may be relevant for motor alterations induced by methamphetamine. In line with this, inherited cerebellar movement disorders in various animal species including humans are associated with increased TH immunoreactivity within intrinsic neurons of the same lobules of the cerebellar cortex.
Assuntos
Inibidores da Captação Adrenérgica/farmacologia , Córtex Cerebelar/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Metanfetamina/farmacologia , Norepinefrina/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Análise de Variância , Animais , Córtex Cerebelar/citologia , Córtex Cerebelar/metabolismo , Córtex Cerebelar/ultraestrutura , Relação Dose-Resposta a Droga , Esquema de Medicação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Imunoeletrônica/métodos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fatores de Tempo , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Parkinsonian patients are treated with dopamine replacement therapy (typically, intermittent administration of the dopamine precursor L-DOPA); however, this is associated with the onset of abnormal involuntary movements, which seriously impair the quality of life. The molecular mechanisms underlying abnormal involuntary movements represent an intense field of investigation in the area of neurobiology of disease, although their aetiology remains unclear. Apart from the fine cellular mechanisms, the pathways responsible for the generation of abnormal involuntary movements may involve changes in neurotransmitter systems. A potential candidate is noradrenaline, since a severe loss of this neurotransmitter characterizes Parkinson's disease, and noradrenergic drugs produce a symptomatic relief of L-DOPA-induced dyskinesia. In previous studies we found that pulsatile dopamine release, in the absence of the physiological noradrenaline innervation, produces motor alterations and ultrastructural changes within striatal neurons. In the present study we demonstrate that a unilateral damage to the noradrenaline system anticipates the onset and worsens the severity of L-DOPA-induced contralateral abnormal involuntary movements in hemi-parkinsonian rats. Similarly, ubiquitin-positive striatal ultrastructural changes occur in unilaterally dopamine-depleted, noradrenaline-deficient rats following chronic L-DOPA administration. This study confirms a significant impact of the noradrenergic system in the natural history of Parkinson's disease and extends its role to the behavioural and morphological effects taking place during pulsatile dopamine replacement therapy.
Assuntos
Dopaminérgicos , Discinesia Induzida por Medicamentos/etiologia , Discinesia Induzida por Medicamentos/patologia , Locus Cerúleo/patologia , Neurônios/patologia , Inibidores da Captação Adrenérgica/administração & dosagem , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Desipramina/administração & dosagem , Modelos Animais de Doenças , Dopamina/metabolismo , Interações Medicamentosas , Lateralidade Funcional , Levodopa/administração & dosagem , Masculino , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Norepinefrina/metabolismo , Oxidopamina/efeitos adversos , Ratos , Ratos Wistar , Teste de Desempenho do Rota-Rod , Índice de Gravidade de Doença , Tirosina 3-Mono-Oxigenase/metabolismoRESUMO
Prion diseases include a group of either sporadic, inherited or infectious disorders characterized by spongiform neurodegeneration and reactive glyosis in several brain regions. Whatever the origin, the neuropathological hallmark of prion diseases is the presence of brain aggregates containing an altered isoform of a cellular protein, named prion protein. Recent findings show the potential toxicity of the normal cellular prion protein, which occurs when its physiological metabolism is altered. In particular, several studies demonstrate that accumulation of the prion protein in the cytosol can be a consequence of an increased amount of misfolded prion proteins, a derangement of the correct protein trafficking or a reduced activity of the ubiquitin-proteasome system. The same effects can be a consequence of a mutation in the gene coding for the prion protein. In all these conditions, one assists to accumulation and self-replication of insoluble prion proteins which leads to a severe disease resembling what observed following typical "prion infections". This article provides an opinion aimed at reconciling the classic Prusiner's theory concerning the "prion concepts" with the present knowledge arising from experimental studies on neurodegenerative disorders, suggesting a few overlapping steps in the pathogenesis of these diseases.
Assuntos
Encéfalo/fisiopatologia , Doenças Priônicas/fisiopatologia , Príons/metabolismo , Encéfalo/metabolismo , Encéfalo/patologia , Transmissão de Doença Infecciosa , Corpos de Inclusão/genética , Corpos de Inclusão/metabolismo , Corpos de Inclusão/patologia , Modelos Neurológicos , Doenças Priônicas/genética , Doenças Priônicas/metabolismo , Príons/genética , Complexo de Endopeptidases do Proteassoma/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Dobramento de Proteína , Transporte Proteico/genética , Ubiquitina/genética , Ubiquitina/metabolismoRESUMO
The Ubiquitin Proteasome System is a multi-enzymatic pathway which degrades polyubiquinated soluble cytoplasmic proteins. This biochemical machinery is impaired both in sporadic and inherited forms of Parkinsonism. In the present paper we focus on the role of the pre-synaptic protein alpha-synuclein in altering the proteasom based on the results emerging from experimental models showing a mechanistic chain of events between altered alpha-synuclein, proteasome impairment and formation of neuronal inclusions and catecholamine cell death.
Assuntos
Doença de Parkinson Secundária/patologia , Complexo de Endopeptidases do Proteassoma/fisiologia , alfa-Sinucleína/fisiologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina , Anfetaminas , Animais , Modelos Animais de Doenças , Dopaminérgicos , Humanos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Ubiquitina/metabolismo , alfa-Sinucleína/genéticaRESUMO
OBJECTIVE: It is known that the placenta acts as an immunological barrier between the mother and fetal "graft" allowing two antigenically different organisms to tolerate one another. Preeclampsia may be considered as a fetal rejection consequent to severe damage at placental endothelial and syncytiotrophoblast level. In order to verify this placental barrier damage we undertook the present study by electron microscopy. STUDY DESIGN: 14 placentae from preeclaptic women, and the same number of placentae from healthy controls were examined. RESULTS: The results showed that endothelial cells from preeclamptic placentae express various and severe alterations, consisting of swollen and bulbous cytoplasm, degenerated inter-endothelial junctions with consequent crossing of fetal blood cells outside the vessels. CONCLUSIONS: These lesions could be the ultrastructural evidence of the placental barrier breakage leading to rejective reaction we presumed to be basis of preeclampsia.
Assuntos
Placenta/ultraestrutura , Pré-Eclâmpsia/patologia , Adulto , Citoplasma/ultraestrutura , Células Endoteliais/ultraestrutura , Endotélio Vascular/ultraestrutura , Feminino , Sangue Fetal , Idade Gestacional , Humanos , Junções Intercelulares/ultraestrutura , Microscopia Eletrônica , Microvilosidades/ultraestrutura , Placenta/irrigação sanguínea , Gravidez , Trofoblastos/ultraestruturaRESUMO
The effect of suramin on testosterone production was evaluated in cancer patients, adult male rats, rat Leydig cells, and NCI-H295 human adrenal cancer cells. Testosterone plasma levels markedly decreased in 14 patients receiving suramin as a therapy for refractory cancer, and in 8 of them, the plasma LH and/or FSH levels increased beyond the normal range. The hCG stimulation test (5000 IU, im) was performed in 8 patients and induced an average 2.1-fold increase in testosterone levels over baseline values. Testicular histology after suramin treatment was available in 1 patient who died of progressive disease; this revealed atrophy of seminiferous tubules and reduced Leydig cells in the interstitium. A significant reduction in plasma testosterone was also observed in rats given 18 mg/kg suramin, ip, twice weekly for 8 weeks, whereas plasma LH and FSH levels did not change significantly. Cytohistochemistry of testes from suramin-treated rats showed a reduced number of 3 beta-hydroxysteroid dehydrogenase-positive cells within the interstitium compared to controls, and light microscopy revealed severe impairment of spermatogenesis. Suramin inhibited the production of testosterone by isolated rat Leydig cells as well as the conversion of pregnenolone to progesterone by the 3 beta-hydroxysteroid dehydrogenase enzyme extracted from rat testes, with 50% inhibitory concentrations (IC50 values) of 108.2 and 87.5 micrograms/mL, respectively. Furthermore, suramin reduced the release of testosterone into the culture medium of NCI-H295 adrenal cancer cells with IC50 values of 91.2 and 83.9 micrograms/mL after 6 and 12 days, respectively. These data provide the first evidence in patients that suramin treatment produces a marked reduction in the circulating levels of testosterone, a result that was also obtained in experimental models.
Assuntos
Suramina/farmacologia , Testosterona/antagonistas & inibidores , 3-Hidroxiesteroide Desidrogenases/metabolismo , Neoplasias das Glândulas Suprarrenais/metabolismo , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Idoso , Animais , Hormônio Foliculoestimulante/sangue , Histocitoquímica , Humanos , Células Intersticiais do Testículo/metabolismo , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Ratos , Ratos Wistar , Testículo/anatomia & histologia , Testículo/efeitos dos fármacos , Testículo/enzimologia , Testosterona/biossíntese , Testosterona/sangue , Células Tumorais CultivadasRESUMO
Lewy bodies (LB) were first described by Lewy in 1912 [1] as neuronal pale eosinophilic inclusions which became a pathological hallmark of Parkinson s disease (PD). In his original study, Lewy defined these inclusions as pale eosinophilic cytoplasmic structures, and studies since then have revealed LB to be ubiquitin-, alpha-synuclein-, and parkin-containing inclusions. This suggests that knowledge of the biochemical steps involved in the genesis of LB might disclose a final common pathway which might be responsible for different types of inherited and sporadic parkinsonism. This would lead to the identification of new therapeutic targets for interfering with disease progression. Although LB were originally described solely in PD, in the last decade these inclusions were described in a spectrum of degenerative disorders ranging from pure movement disorders to dementia. This suggests that common biochemical alterations leading to the formation of intracellular inclusions might underlie various pathological conditions. Consequently, the knowledge of the biochemical steps involved in the formation of neuronal inclusions could represent a key to develop new therapeutic strategies. In recent years it has been possible to develop both in vitro and in vivo neuronal inclusions resembling Lewy bodies. These experimental approaches have ranged from the use of alpha-synuclein transgenic mice to the continuous exposure to a mitochondrial complex I inhibitor. The aim of the present paper is to review briefly, recent advances on Lewy body research to achieve new insight into the etiology of PD and the molecular events leading to neurodegeneration.
Assuntos
Avaliação Pré-Clínica de Medicamentos/tendências , Corpos de Lewy/metabolismo , Corpos de Lewy/patologia , Doenças Neurodegenerativas/fisiopatologia , Ubiquitinas/metabolismo , Animais , Progressão da Doença , Ativadores de Enzimas/farmacologia , Previsões , Humanos , Corpos de Lewy/química , Complexos Multienzimáticos/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Neurônios/metabolismo , Neurônios/patologia , Transtornos Parkinsonianos/fisiopatologia , Relação Estrutura-AtividadeRESUMO
Recently, we described the occurrence of a dehydroascorbate reductase within the rat CNS. This enzyme regenerates ascorbate after it is oxidized during normal aerobic metabolism. In this work, we describe the neuronal compartmentalization of the enzyme, using transmission electron microscopy of those brain areas in which the enzyme was most densely present when observed under light microscopy. In parallel biochemical studies, we performed immunoblotting and measured the enzyme activity of the cytoplasm and different nuclear fractions. Given the abundance of ascorbate in the caudate-putamen, we focused mostly on the occurrence of dehydroascorbate reductase at the striatal subcellular level. We also studied cerebellar Purkinje cells, hippocampal CA3 pyramidal cells and giant neurons in the magnocellular part of the red nucleus. In addition to neurons, immunolabeling was found in striatal endothelial cells, in the basal membrane of blood vessels and in perivascular astrocytes. In neuronal cytosol, the enzyme was observed in a peri-nuclear position and on the nuclear membrane. In addition, in both the striatum and the cerebellum, we found the enzyme within myelin sheets. Dehydroascorbate reductase was also present in the nucleus of neurons, as further indicated by measuring enzyme activity and by immunoblotting selected nuclear fractions. Immunocytochemical labeling confirmed that the protein was present in isolated pure nuclear fractions. Given the great amount of free radicals which are constantly generated in the CNS, the discovery of a new enzyme with antioxidant properties which translocates into neuronal nuclei appears to be a potential starting point to develop alternative strategies in neuroprotection.
Assuntos
Ácido Ascórbico/biossíntese , Encéfalo/enzimologia , Compartimento Celular/fisiologia , Glutationa/metabolismo , Neurônios/enzimologia , Oxirredutases/metabolismo , Animais , Encéfalo/ultraestrutura , Cerebelo/metabolismo , Cerebelo/ultraestrutura , Citosol/metabolismo , Feminino , Hipocampo/metabolismo , Hipocampo/ultraestrutura , Imuno-Histoquímica , Microscopia Eletrônica , Neostriado/metabolismo , Neostriado/ultraestrutura , Neurônios/ultraestrutura , Ratos , Ratos Wistar , Núcleo Rubro/metabolismo , Núcleo Rubro/ultraestrutura , Frações Subcelulares/metabolismo , Frações Subcelulares/ultraestruturaRESUMO
RATIONALE: 3,4-Methylenedioxymethamphetamine (MDMA) is an amphetamine derivative, which is neurotoxic to both serotonin (5HT) and dopamine (DA) nerve terminals. Previous reports, carried out in rodents and non-human primates, demonstrated neurotoxicity to monoamine axon terminals, although no study has analyzed nigral and striatal cell bodies at the sub-cellular level. OBJECTIVE: In this study, we examined intrinsic nigral and striatal cells, and PC12 cell cultures to evaluate whether, in mice, MDMA might affect nigral and striatal cell bodies. METHODS: After administering MDMA, we analyzed effects induced in vivo and in vitro using high-performance liquid chromatography (HPLC) analysis, light- and electron microscopy with immunocytochemistry, and DNA comet assay. RESULTS: We found that MDMA (5 mg/kg x4, 2 h apart), besides a decrease of nigrostriatal DA innervation and 5HT loss, produces neuronal inclusions within nigral and intrinsic striatal neurons consisting of multi-layer ubiquitin-positive whorls extending to the nucleus of the cell. These fine morphological changes are associated with clustering of heat shock protein (HSP)-70 in the nucleus, very close to chromatin filaments. In the same experimental conditions, we could detect oxidation of DNA bases followed by DNA damage. The nature of inclusions was further investigated using PC12 cell cultures. CONCLUSIONS: The present findings lead to re-consideration of the neurotoxic consequences of MDMA administration. In fact, occurrence of ubiquitin-positive neuronal inclusions and DNA damage both in nigral and striatal cells sheds new light into the fine alterations induced by MDMA, also suggesting the involvement of nuclear and cytoplasmic components of the ubiquitin-proteasome pathway in MDMA toxicity.
Assuntos
Corpo Estriado/efeitos dos fármacos , Dano ao DNA , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Neurônios/metabolismo , Serotoninérgicos/toxicidade , Substância Negra/efeitos dos fármacos , Ubiquitina/metabolismo , Animais , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Dopamina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/ultraestrutura , Células PC12 , Ratos , Substância Negra/metabolismo , Substância Negra/patologiaRESUMO
Amphetamine derivatives, such as methamphetamine (METH) and 3,4-methylenedioxymethamphetamine (MDMA), act as monoaminergic neurotoxins in the central nervous system. Although there are slight differences in their mechanism of action, these compounds share a final common pathway, which involves dopamine release and oxidative stress. Apart from striatal toxicity involving monoamine axons, no previous report evidenced any alteration at the striatal level concerning postsynaptic sites. Given the potential toxicity for extracellular dopamine at the striatal level, and the hypothesis for neurotoxic effects of dopamine on striatal medium-sized neurons in Huntington's disease, we evaluated at an ultrastructural level the effects of MDMA on intrinsic striatal neurons of the mouse. In this study, administering MDMA, we noted ultrastructural alterations of striatal postsynaptic GABAergic cells consisting of neuronal inclusions shaped as whorls of concentric membranes. These whorls stained for ubiquitin but not for synuclein and represent the first morphologic correlate of striatal postsynaptic effects induced by MDMA.
Assuntos
Corpo Estriado/ultraestrutura , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Sinapses/ultraestrutura , Animais , Benzilaminas/administração & dosagem , Benzilaminas/toxicidade , Monoaminas Biogênicas/metabolismo , Cromatografia Líquida de Alta Pressão , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Dopamina/metabolismo , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , N-Metil-3,4-Metilenodioxianfetamina/administração & dosagem , Fosfatidilcolinas/metabolismo , Sinapses/efeitos dos fármacosRESUMO
The monoamine neurotoxin methamphetamine (METH) is commonly used as an experimental model for Parkinson's disease (PD). In fact, METH-induced striatal dopamine (DA) loss is accompanied by damage to striatal nerve endings arising from the substantia nigra. On the other hand, PD is characterized by neuronal inclusions within nigral DA neurons. These inclusions contain alpha-synuclein, ubiquitin, and various components of a metabolic pathway named the ubiquitin-proteasome (UP) system, while mutation of genes coding for various components of the UP system is responsible for inherited forms of PD. In this presentation we demonstrate for the first time the occurrence of neuronal inclusions in vivo in the nigrostriatal system of the mouse following administration of METH. We analyzed, in vivo and in vitro, the shape and the fine structure of these neuronal bodies by using transmission electron microscopy. Immunocytochemical investigation showed that these METH-induced cytosolic inclusions stain for ubiquitin, alpha-synuclein, and UP-related molecules, thus sharing similar components with Lewy bodies occurring in PD, with an emphasis on enzymes belonging to the UP system. In line with this, blockade of this multicatalytic pathway by the selective inhibitor epoxomycin produced cell inclusions with similar features. Moreover, using a multifaceted pharmacological approach, we could demonstrate the need for endogenous DA in order to form neuronal inclusions.
Assuntos
Metanfetamina/toxicidade , Complexo de Endopeptidases do Proteassoma/ultraestrutura , Inibidores de Proteassoma , Animais , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Células PC12 , Ratos , Substância Negra/efeitos dos fármacos , Substância Negra/ultraestruturaRESUMO
The psychostimulant 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") is an amphetamine derivative that is widely abused. In previous studies, depending on the animal species, neurotoxicity has been demonstrated for either serotonin (5-HT) or/and dopamine (DA) nerve endings. These studies focused on the basal ganglia circuitry; however, in humans chronic abuse of MDMA often results in neurological symptoms that last after MDMA withdrawal and are not related to the extrapyramidal system such as electroencephalographic (EEG) abnormalities and cognitive impairment. These alterations might be due to the concomitant intake of other illicit compounds, the consequence of MDMA-induced hyperthermia, or to a primary neurotoxicity directed to extrastriatal regions. These observations call for a more in-depth analysis on the potential involvement of brain areas outside the basal ganglia in the toxic effects induced primarily by MDMA. In the present study, we treated C57Black mice chronically (25 days) with daily injections of MDMA (2.5 mg/kg). During treatments, mice were monitored in order to detect behavioral modifications, and epidural electrodes were installed to perform EEG recording. Behavioral data showed a sensitization as measured by locomotor activity, which related to progressive and long-lasting EEG changes and neuronal degeneration within the hippocampus.
Assuntos
Eletroencefalografia/efeitos dos fármacos , Corantes Fluorescentes/análise , N-Metil-3,4-Metilenodioxianfetamina/administração & dosagem , Animais , Gânglios da Base/química , Gânglios da Base/efeitos dos fármacos , Fluoresceínas , Imuno-Histoquímica , Locomoção/efeitos dos fármacos , Locomoção/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Compostos OrgânicosRESUMO
The cytotoxicity and cardiotoxicity of benzoyl mustard (FCE 24517) and epoxamido (FCE 24561) synthetic derivatives of distamycin A were reported in the present study. The 50% inhibiting concentration (IC50) of colony formation of FCE 24517 on human SNB-19 glioblastoma, A2780 ovarian cancer and DU 145 prostate cancer was at least three times lower than that of FCE 24561; on the same cell lines the IC50 of DXR was up to 14 and 240 times higher than that of FCE 24561 and FCE 24517, respectively. Isolated rat hearts perfused with concentrations of both derivatives equivalent to their respective IC50 values did not show any significant change in ECG parameters, contractility and coronary flow. Compared to control hearts, FCE 24517 10(-6) M induced a significant increase in PR interval, reduction in + dF/dtmax, heart rate and coronary flow, while FCE 24561 10(-6) M produced a modest but significant increase in S alpha T segment and decrease in + dF/dtmax. Rats treated with FCE 24561 3, 6 or 12 mg/kg, intravenously (i.v.), once weekly for 3 weeks had a modest increase in S alpha T segment and QRS complex duration, while a slight alteration of S alpha T segment and QRS complex duration were observed in rats given FCE 24517 1 or 2 mg/kg i.v. once weekly for 3 weeks. No cardiac histologic alterations were found in hearts from rats receiving FCE 24517 or FCE 24561. For comparison, the cardiotoxicity of doxorubicin (DXR) was evaluated in the same experimental models; perfusion of hearts with DXR 10(-6) M induced severe alterations in all parameters of the isolated hearts; the administration of DXR 3 mg/kg i.v. once a week for 3 weeks was associated with a widening of the S alpha T segment and QRS complex and cardiac histologic picture was markedly altered. In conclusion, distamycin A derivatives display elevated cytotoxicity while no substantial cardiotoxicity was observed.
Assuntos
Antineoplásicos/toxicidade , Distamicinas/toxicidade , Coração/efeitos dos fármacos , Compostos de Mostarda Nitrogenada/toxicidade , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Distamicinas/administração & dosagem , Distamicinas/farmacologia , Doxorrubicina/toxicidade , Feminino , Humanos , Injeções Intravenosas , Compostos de Mostarda Nitrogenada/administração & dosagem , Compostos de Mostarda Nitrogenada/farmacologia , Perfusão , Ratos , Ratos Wistar , Células Tumorais CultivadasRESUMO
While reserpine and nicardipine pretreatment induced a more or less marked decrease in typical red-orange doxorubicin fluorescence in certain rat tissues, such as spleen, kidney and large intestine, the myocardial tissue (right atrium and left ventriculum) did not show any significant variations in nuclear doxorubicin storage. This different behaviour of cardiac tissue may be related to the well-known doxorubicin cardiotoxicity.
Assuntos
Doxorrubicina/metabolismo , Miocárdio/metabolismo , Nicardipino/farmacologia , Pré-Medicação , Reserpina/farmacologia , Animais , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/metabolismo , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Masculino , Distribuição Aleatória , Ratos , Ratos Endogâmicos , Baço/metabolismoRESUMO
OBJECTIVE: To investigate whether formation of nitrotyrosine in the nasal polyps of atopic patients occurs. STUDY DESIGN: A nonrandomized, retrospective, controlled qualitative and quantitative study. METHODS: Nasal polyp tissue samples were acquired from 12 atopic patients. Control fragments of nasal mucosa were taken from 10 patients undergoing corrective surgery of the nasal septum. For routine histologic examinations, hematoxylin-eosin staining was used. Low-magnification microscopy was designed to yield pathologic characteristics and high magnification to quantify the number of eosinophils in the subepithelial connective tissue. Presence of nitrotyrosine was assessed by immunohistochemical method. RESULTS: Hematoxylin-eosin staining revealed presence of numerous eosinophils in the epithelium and in the subepithelial connective tissue. All polyps were characterized by epithelial damage. Nitrotyrosine was present in the eosinophils, in the ciliated cell, and in cells of the damaged epithelium. Goblet cells, glands, and vessels were found to be negative. No significant differences concerning the localization of nitrotyrosine were recognized among the examined nasal polyps. CONCLUSIONS: Nitrotyrosine immunohistochemical staining in nasal-polyp tissues suggested the existence of progressive epithelium injury caused by peroxynitrite. Consequences of peroxynitrite formation in eosinophils remain to be precisely established. The lack of nitrotyrosine in glands and blood vessels indicated that peroxynitrite does not have a significant role in the vascular and glandular dysfunction of nasal polyps.
Assuntos
Hipersensibilidade Imediata/metabolismo , Pólipos Nasais/química , Tirosina/análogos & derivados , Tirosina/metabolismo , Adulto , Estudos de Casos e Controles , Eosinófilos/química , Feminino , Humanos , Imuno-Histoquímica , Masculino , Mucosa Nasal/química , Mucosa Nasal/patologia , Pólipos Nasais/patologia , Ácido Peroxinitroso/metabolismo , Estudos RetrospectivosRESUMO
The present study was performed to examine the effect of varying duration of noise exposure on rat adrenal gland. Animals were exposed to noise for 1, 6 and 12 h continuously and the sections obtained from exposed rats were compared to those from corresponding controls. No significant ultrastructural changes were found in the zona glomerulosa, while mitochondria of the zona fasciculata showed matrix dilution and cristolysis after 1 and 12 h of noise stress. At all exposure times examined, the zona reticularis exhibited areas of diluted cytoplasm, disarranged endoplasmic reticulum, membrane vestigia and some altered mitochondria. Diluted cytoplasmic areas appeared in noradrenaline- and adrenaline-storing cells after 6 and 12 h of exposure, respectively. Our findings indicate that each zona of the adrenal cortex and the two cell types of adrenal medulla show a differential reaction to noise stress.
Assuntos
Glândulas Suprarrenais/patologia , Ruído , Estresse Fisiológico/patologia , Córtex Suprarrenal/patologia , Medula Suprarrenal/patologia , Animais , Masculino , Ratos , Ratos WistarRESUMO
Reserpine pre-treatment causes a considerable decrease in typical red-orange doxorubicin fluorescence of the organs examined (kidney, large intestine, spleen) and a similar picture is observed after calcium antagonists administration. This effect is far more evident in the spleen and large intestine than in the kidney; moreover, it seems more marked in young rats compared with aged ones. An inhibitory action of these drugs on the anthracycline transport carrier through the cell membrane is hypothesized.
Assuntos
Doxorrubicina/farmacocinética , Intestino Grosso/metabolismo , Rim/metabolismo , Nicardipino/farmacologia , Reserpina/farmacologia , Baço/metabolismo , Verapamil/farmacologia , Envelhecimento , Animais , Intestino Grosso/efeitos dos fármacos , Intestino Grosso/crescimento & desenvolvimento , Rim/efeitos dos fármacos , Rim/crescimento & desenvolvimento , Masculino , Microscopia de Fluorescência , Desenvolvimento Muscular , Músculo Liso/efeitos dos fármacos , Músculo Liso/crescimento & desenvolvimento , Músculo Liso/metabolismo , Especificidade de Órgãos , Ratos , Ratos Endogâmicos , Baço/efeitos dos fármacos , Baço/crescimento & desenvolvimentoRESUMO
The effects of pretreatment with a benzodiazepine (diazepam) on the cardiovascular system of rats exposed to noise were evaluated. Animals were given diazepam before noise treatment; time exposure was one and six consecutive hours. Examination of preparations (corresponding portions of right atrium and ventricle), obtained using the histofluorescence method, showed that noise treatment increased the density of noradrenergic pattern. In diazepam-pretreated tissues the fluorescent fibres resulted to be thinner and less numerous, in particular after one hour of noise exposure. Our present data demonstrate that diazepam exerts a protective action on the heart, more evident after one hour of treatment.