RESUMO
INTRODUCTION: The variability in late toxicities among childhood cancer survivors (CCS) is only partially explained by treatment and baseline patient characteristics. Inter-individual variability in the association between treatment exposure and risk of late toxicity suggests that genetic variation possibly modifies this association. We reviewed the available literature on genetic susceptibility of late toxicity after childhood cancer treatment related to components of metabolic syndrome, bone mineral density, gonadal impairment and hearing impairment. METHODS: A systematic literature search was performed, using Embase, Cochrane Library, Google Scholar, MEDLINE, and Web of Science databases. Eligible publications included all English language reports of candidate gene studies and genome wide association studies (GWAS) that aimed to identify genetic risk factors associated with the four late toxicities, defined as toxicity present after end of treatment. RESULTS: Twenty-seven articles were identified, including 26 candidate gene studies: metabolic syndrome (nâ¯=â¯6); BMD (nâ¯=â¯6); gonadal impairment (nâ¯=â¯2); hearing impairment (nâ¯=â¯12) and one GWAS (metabolic syndrome). Eighty percent of the genetic studies on late toxicity after childhood cancer had relatively small sample sizes (nâ¯<â¯200), leading to insufficient power, and lacked adjustment for multiple comparisons. Only four (4/26â¯=â¯15%) candidate gene studies had their findings validated in independent replication cohorts as part of their own report. CONCLUSION: Genetic susceptibility associations are not consistent or not replicated and therefore, currently no evidence-based recommendations can be made for hearing impairment, gonadal impairment, bone mineral density impairment and metabolic syndrome in CCS. To advance knowledge related to genetic variation influencing late toxicities among CCS, future studies need adequate power, independent cohorts for replication, harmonization of disease outcomes and sample collections, and (international) collaboration.
Assuntos
Sobreviventes de Câncer , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/genética , Variação Genética/fisiologia , Transtornos de Início Tardio/genética , Neoplasias/genética , Lesões por Radiação/genética , Densidade Óssea/genética , Sobreviventes de Câncer/estatística & dados numéricos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Transtornos de Início Tardio/epidemiologia , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Síndrome Metabólica/genética , Neoplasias/epidemiologia , Neoplasias/terapia , Lesões por Radiação/epidemiologia , Fatores de TempoRESUMO
Hepatocellular carcinoma (HCC) develops on the background of chronic hepatitis. Leukocytes found within the HCC microenvironment are implicated as regulators of tumour growth. We show that diethylnitrosamine (DEN)-induced murine HCC is attenuated by antibody-mediated depletion of hepatic neutrophils, the latter stimulating hepatocellular ROS and telomere DNA damage. We additionally report a previously unappreciated tumour suppressor function for hepatocellular nfkb1 operating via p50:p50 dimers and the co-repressor HDAC1. These anti-inflammatory proteins combine to transcriptionally repress hepatic expression of a S100A8/9, CXCL1 and CXCL2 neutrophil chemokine network. Loss of nfkb1 promotes ageing-associated chronic liver disease (CLD), characterized by steatosis, neutrophillia, fibrosis, hepatocyte telomere damage and HCC. Nfkb1(S340A/S340A)mice carrying a mutation designed to selectively disrupt p50:p50:HDAC1 complexes are more susceptible to HCC; by contrast, mice lacking S100A9 express reduced neutrophil chemokines and are protected from HCC. Inhibiting neutrophil accumulation in CLD or targeting their tumour-promoting activities may offer therapeutic opportunities in HCC.
Assuntos
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas Experimentais/genética , Subunidade p50 de NF-kappa B/genética , Neutrófilos/imunologia , Alquilantes/toxicidade , Animais , Calgranulina A/genética , Calgranulina B/genética , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/imunologia , Quimiocina CXCL1/genética , Quimiocina CXCL2/genética , Dietilnitrosamina/toxicidade , Hepatopatias/genética , Hepatopatias/imunologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/imunologia , Camundongos , Camundongos Knockout , MutaçãoRESUMO
BACKGROUND: The prevalence of low bone mineral density (BMD) in adult survivors of childhood acute lymphoblastic leukemia (ALL), and the degree of recovery or decline, are not well elucidated. PROCEDURE: Study subjects (age ≥ 18 years and ≥10 years post-diagnosis) participated in an institutional follow-up protocol and risk-based clinical evaluation based on Children's Oncology Group guidelines. Trabecular volumetric BMD was ascertained using quantitative computed tomography, reported as age- and sex-specific Z-scores. RESULTS: At median age 31 years, 5.7% of 845 subjects had a BMD Z-score of ≤-2 and 23.8% had a Z-score of -1 to -2. Cranial radiation dose of ≥24 Gy, but not cumulative methotrexate or prednisone equivalence doses, was associated with a twofold elevated risk of a BMD Z-score of ≤-1. The cranial radiation effect was stronger in females than in males. In a subset of 400 subjects, 67% of those who previously had a BMD Z-score of ≤-2 improved by one or more categories a median of 8.5 years later. CONCLUSIONS: Very low BMD was relatively uncommon in this sample of adult survivors of childhood ALL, and BMD Z-scores tended to improve from adolescence to young adulthood. High-dose cranial or craniospinal radiation exposure was the primary predictor of suboptimal BMD in our study. Given that cranial radiation treatment for childhood ALL is used far more sparingly now than in earlier treatment eras, concerns about persistently low BMD among most current childhood ALL patients may be unwarranted.
Assuntos
Densidade Óssea , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/fisiopatologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Sobreviventes , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Estudos Retrospectivos , Fatores SexuaisRESUMO
BACKGROUND: There is a lack of published evidence for treatment and outcome measures for vulval erosive lichen planus (ELPV). OBJECTIVES: To conduct a multicentre case note review to examine real-life management of ELPV comparing current U.K. practice against an agreed audit standard. METHODS: Criteria for standards of care for which to evaluate current service provision were set following communication with experts from the British Society for the Study of Vulval Disease. Participants from 10 U.K. centres included nine dermatologists and one gynaecologist who run specialist vulval clinics. Standards examined the documentation of disease severity/impact measures, the use of diagnostic biopsies, treatments used and assessment of treatment response. RESULTS: Audit data were collected from 172 patients. Documentation of symptoms/clinical findings was excellent (99%, 170/172). A schematic diagram was present in the notes of 87% (150/172). Patient-related disease impact measures including Dermatology Life Quality Index (3%, 6/172) or visual analogue scales (1%, 2/172) were less well documented. Biopsies were performed in 78% (135/172); 71% (96/135) showed histological features consistent with erosive lichen planus. Squamous cell carcinoma developed in four patients (two vulval, two oral) and vulval intraepithelial neoplasia in two further patients. Recommended first-line treatment with a very potent topical steroid was used in 75% (129/172) with improvement in 66% (85/129). Significant variation in second-line therapy was seen. CONCLUSIONS: Wide variation in U.K. practice demonstrates the absence of standardized guidance for treating ELPV and the need for vulval-specific outcomes. This audit should act as a framework towards improving ELPV management and to plan future research in this area.
Assuntos
Atenção à Saúde/normas , Líquen Plano/terapia , Doenças da Vulva/terapia , Administração Cutânea , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios , Feminino , Humanos , Imunossupressores/administração & dosagem , Líquen Plano/diagnóstico , Auditoria Médica , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Guias de Prática Clínica como Assunto , Qualidade de Vida , Esteroides/administração & dosagem , Reino Unido , Doenças da Vulva/diagnósticoRESUMO
BACKGROUND: The use of assisted reproductive technology (ART) is now well established in many countries and the first generations of offspring are reaching maturity. We reviewed the published literature to describe the available evidence about health outcomes in ART-conceived young people who were of an adolescent age or older. METHODS: The EMBASE, Medline and PsychINFO databases were searched from January 1998 to October 2010. Key inclusion criteria were that the study sample have a mean age of ≥ 12 years or a mean follow-up period of ≥ 12 years and were conceived by ART. RESULTS: Seven publications reported physical health outcomes and 10 reported psychosocial health outcomes in ART offspring. Compared with control groups, some differences in physiological outcomes in relation to growth and development, chronic illness and risk of cancer have been reported. Overall, psychosocial studies of ART-conceived young people indicate that their cognitive function and psychological and social adjustment are similar to that of comparison groups. CONCLUSIONS: Overall, nine ART-conceived populations of this age group have been studied. Most samples included < 300 participants and methodologies varied between studies. Health information on this age group is therefore limited and the clinical significance of the findings remains unclear. Further research focusing on ART-conceived young adults is needed, particularly in relation to neurological health outcomes where no studies have been reported to date.
Assuntos
Adaptação Psicológica , Desenvolvimento do Adolescente , Técnicas de Reprodução Assistida/psicologia , Adolescente , Feminino , Seguimentos , Humanos , Masculino , Relações Pais-Filho , Estudos Retrospectivos , Fatores de Risco , Adulto JovemRESUMO
Robust protocols for microarray gene expression profiling of archival formalin-fixed paraffin-embedded tissue (FFPET) are needed to facilitate research when availability of fresh-frozen tissue is limited. Recent reports attest to the feasibility of this approach, but the clinical value of these data is poorly understood. We employed state-of-the-art RNA extraction and Affymetrix microarray technology to examine 34 archival FFPET primary extremity soft tissue sarcomas. Nineteen arrays met stringent QC criteria and were used to model prognostic signatures for metastatic recurrence. Arrays from two paired frozen and FFPET samples were compared: although FFPET sensitivity was low ( approximately 50%), high specificity (95%) and positive predictive value (92%) suggest that transcript detection is reliable. Good agreement between arrays and real time (RT)-PCR was confirmed, especially for abundant transcripts, and RT-PCR validated the regulation pattern for 19 of 24 candidate genes (overall R(2)=0.4662). RT-PCR and immunohistochemistry on independent cases validated prognostic significance for several genes including RECQL4, FRRS1, CFH and MET - whose combined expression carried greater prognostic value than tumour grade - and cmet and TRKB proteins. These molecules warrant further evaluation in larger series. Reliable clinically relevant data can be obtained from archival FFPET, but protocol amendments are needed to improve the sensitivity and broad application of this approach.
Assuntos
Perfilação da Expressão Gênica , Neoplasias/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Biomarcadores Tumorais/genética , Formaldeído , Humanos , Neoplasias/patologia , Inclusão em Parafina , Prognóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fixação de TecidosRESUMO
Mainstream cigarette smoke (MSS) from 12 US cigarette brands and two reference cigarettes was evaluated to determine concentrations of dioxins (i.e., polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs)). The study included three 'tar' ranges based on Federal Trade Commission (FTC) determination: Low Yield (LY) < or = 5.5, Medium Yield (MY) 9.6-12.2, and High Yield (HY)> or = 14.5 mg/cig. Of the brands studied, the HY cigarettes yielded the greatest mean concentrations of 2005 World Health Organization Toxic Equivalents (WHO-TEQs) on a per cigarette basis. WHO-TEQ levels in LY cigarettes were significantly lower than for HY cigarettes (p=0.039) on a yield per cigarette basis and WHO-TEQ concentrations correlated with 'tar' yield (r=0.73, p=0.007), as did concentration on a WHO-TEQ per body mass per day basis (r=0.73, p=0.007). However, a statistically significant relationship was not observed between 'tar' yield levels and WHO-TEQ concentrations on a per mg Total Particulate Matter (TPM) basis. Concentrations for all brands tested ranged from 0.44 to 3.88 fg WHO-TEQ/mg TPM. Maximum daily exposure estimates calculated from this range (0.004-0.074 pg WHO-TEQ/kg bw/day) are below the current WHO Tolerable Daily Intake range of 1-5 pg/kg bw/day.
Assuntos
Dioxinas/análise , Poluentes Ambientais/análise , Nicotiana/química , Fumaça/análise , Interpretação Estatística de Dados , Filtração , Material Particulado/análise , Bifenilos Policlorados/análise , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análise , Padrões de Referência , Medição de Risco , Estados UnidosRESUMO
The aim of this study was to examine the impact of Friedreich ataxia (FRDA) on quality of life (QOL) using a generic tool to explore factors potentially associated with health status. Sixty-three individuals with genetically confirmed FRDA, self completed the Medical Outcomes Study 36 item Short Form Health Survey Version 2 (SF-36V2) and were assessed using the FRDA Rating Scale. Disease-specific, demographic, and social characteristics were also recorded. SF-36V2 results were compared with Australian population norms. Sample subgroups of disease severity and age at disease onset were reviewed. Physical and mental component summaries were examined in relation to clinical and social characteristics using multiple linear regression. QOL is significantly worse in individuals with FRDA compared with population norms. Those with severe disease did not perceive a lower QOL than those with mild or moderate disease except in their physical functioning. A later age of onset and increased disease severity were negatively associated with physical QOL, whilst, increased disease duration was positively associated with mental QOL. There were limitations associated with the use of SF-36V2 in the FRDA population. Further exploration of health-related QOL and FRDA may benefit from the use of a more appropriate generic tool.
Assuntos
Demografia , Ataxia de Friedreich/psicologia , Relações Interpessoais , Qualidade de Vida , Adulto , Idade de Início , Austrália , Feminino , Ataxia de Friedreich/fisiopatologia , Nível de Saúde , Indicadores Básicos de Saúde , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Inquéritos e QuestionáriosRESUMO
The loss of dopamine in idiopathic or animal models of Parkinson's disease induces synchronized low-frequency oscillatory burst-firing in subthalamic nucleus neurones. We sought to establish whether these firing patterns observed in vivo were preserved in slices taken from dopamine-depleted animals, thus establishing a role for the isolated subthalamic-globus pallidus complex in generating the pathological activity. Mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) showed significant reductions of over 90% in levels of dopamine as measured in striatum by high pressure liquid chromatography. Likewise, significant reductions in tyrosine hydroxylase immunostaining within the striatum (>90%) and tyrosine hydroxylase positive cell numbers (65%) in substantia nigra were observed. Compared with slices from intact mice, neurones in slices from MPTP-lesioned mice fired significantly more slowly (mean rate of 4.2 Hz, cf. 7.2 Hz in control) and more irregularly (mean coefficient of variation of inter-spike interval of 94.4%, cf. 37.9% in control). Application of ionotropic glutamate receptor antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 2-amino-5-phosphonopentanoic acid (AP5) and the GABA(A) receptor antagonist picrotoxin caused no change in firing pattern. Bath application of dopamine significantly increased cell firing rate and regularized the pattern of activity in cells from slices from both MPTP-treated and control animals. Although the absolute change was more modest in control slices, the maximum dopamine effect in the two groups was comparable. Indeed, when taking into account the basal firing rate, no differences in the sensitivity to dopamine were observed between these two cohorts. Furthermore, pairs of subthalamic nucleus cells showed no correlated activity in slices from either control (21 pairs) or MPTP-treated animals (20 pairs). These results indicate that the isolated but interconnected subthalamic-globus pallidus network is not itself sufficient to generate the aberrant firing patterns in dopamine-depleted animals. More likely, inputs from other regions, such as the cortex, are needed to generate pathological oscillatory activity.
Assuntos
1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Dopamina/metabolismo , Neurônios/efeitos dos fármacos , Neurotoxinas/farmacocinética , Núcleo Subtalâmico/citologia , Animais , Química Encefálica/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão/métodos , Dopamina/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Imuno-Histoquímica/métodos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Núcleo Subtalâmico/efeitos dos fármacos , Núcleo Subtalâmico/metabolismoRESUMO
Oestrogen (E) is essential for normal and cancer development in the breast, while anti-oestrogens have been shown to reduce the risk of the disease. However, little is known about the effect of E on gene expression in the normal human breast, particularly when the epithelium and stroma are intact. Previous expression profiles of the response to E have been performed on tumour cell lines, in the absence of stroma. We investigated gene expression in normal human breast tissue transplanted into 9-10-week-old female athymic nude (Balb/c nu/nu) mice. After 2 weeks, when epithelial proliferation is minimal, one-third of the mice were treated with 17beta-oestradiol (E2) to give human luteal-phase levels in the mouse, which we have previously shown to induce maximal epithelial cell proliferation. RNA was isolated from treated and untreated mice, labelled and hybridized to Affymetrix HG-U133A (human) GeneChips. Gene expression levels were generated using BioConductor implementations of the RMA and MAS5 algorithms. E2 treatment was found to represent the largest source of variation in gene expression and cross-species hybridization of mouse RNA from xenograft samples was demonstrated to be negligible. Known E2-responsive genes (such as TFF1 and AREG), and genes thought to be involved in breast cancer metastasis (including mammoglobin, KRT19 and AGR2), were upregulated in response to E treatment. Genes known to be co-expressed with E receptor alpha in breast cancer cell lines and tumours were both upregulated (XBP-1 and GREB1) and downregulated (RARRES1 and GATA3). In addition, genes that are normally expressed in the myoepithelium and extracellular matrix that maintain the tissue microenvironment were also differentially expressed. This suggests that the response to oestrogen in normal breast is highly dependent upon epithelial-stromal/myoepithelial interactions which maintain the tissue microenvironment during epithelial cell proliferation.
Assuntos
Mama/metabolismo , Estradiol/farmacologia , Perfilação da Expressão Gênica , Expressão Gênica/efeitos dos fármacos , Adulto , Animais , Mama/citologia , Mama/efeitos dos fármacos , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Feminino , Humanos , Camundongos , Camundongos Nus , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo , Transplante HeterólogoRESUMO
Extracellular single-unit recordings in mouse brain slices were used to determine the effect of exogenously applied 5-HT on STN neurones. Recordings were made from 74 STN cells which fired action potentials at a regular rate of 7.19+/-0.5 Hz. In 61 cells (82%), 5-HT application increased STN neurone firing rate (10 microM, 180+/-16.8%, n=35) with an estimated EC(50) of 5.4 microM. The non-specific 5-HT(2) receptor agonist alpha-methyl 5-HT (1-10 microM) mimicked 5-HT induced excitations (15 cells). These excitations were significantly reduced by pre-perfusion with the specific 5-HT(2C) receptor antagonist RS102221 (500 nM, 9 cells) and the 5HT(4) antagonist GR113808 (500 nM, 7 cells). In 6 cells (8%) 5-HT induced biphasic responses where excitation was followed by inhibition, while in 7 cells (9%) inhibition of firing rate was observed alone. Inhibitory responses were reduced by the 5-HT(1A) antagonist WAY100135 (1 microM, 4 cells). No inhibitory responses were observed following alpha-methyl 5-HT applications. Both the excitations and inhibitions were unaffected by picrotoxin (50 microM, n=5) and CNQX (10 microM, n=5) indicative of direct postsynaptic effects. Thus, in STN neurones, 5-HT elicits two distinct effects, at times on the same neurone, the first being an excitation which is mediated by 5-HT(2C) and 5-HT(4) receptors and the second an inhibition which is mediated by 5-HT(1A) receptors.
Assuntos
Receptor 5-HT1A de Serotonina/efeitos dos fármacos , Receptor 5-HT2C de Serotonina/efeitos dos fármacos , Receptores 5-HT4 de Serotonina/efeitos dos fármacos , Serotonina/farmacologia , Núcleo Subtalâmico/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Eletrofisiologia , Globo Pálido/efeitos dos fármacos , Globo Pálido/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Piperazinas/farmacologia , Antagonistas da Serotonina/farmacologia , Compostos de Espiro/farmacologia , Núcleo Subtalâmico/citologia , Sulfonamidas/farmacologiaRESUMO
In accordance with its central role in basal ganglia circuitry, changes in the rate of action potential firing and pattern of activity in the globus pallidus (GP)-subthalamic nucleus (STN) network are apparent in movement disorders. In this study we have developed a mouse brain slice preparation that maintains the functional connectivity between the GP and STN in order to assess its role in shaping and modulating bursting activity promoted by pharmacological manipulations. Fibre-tract tracing studies indicated that a parasagittal slice cut 20 deg to the midline best preserved connectivity between the GP and the STN. IPSCs and EPSCs elicited by electrical stimulation confirmed connectivity from GP to STN in 44/59 slices and from STN to GP in 22/33 slices, respectively. In control slices, 74/76 (97%) of STN cells fired tonically at a rate of 10.3 +/- 1.3 Hz. This rate and pattern of single spiking activity was unaffected by bath application of the GABA(A) antagonist picrotoxin (50 microM, n = 9) or the glutamate receptor antagonist (6-cyano-7-nitroquinoxaline-2, 3-dione (CNQX) 10 microM, n = 8). Bursting activity in STN neurones could be induced pharmacologically by application of NMDA alone (20 microm, 3/18 cells, 17%) but was more robust if NMDA was applied in conjunction with apamin (20-100 nM, 34/77 cells, 44%). Once again, neither picrotoxin (50 microM, n = 5) nor CNQX (10 microM, n = 5) had any effect on the frequency or pattern of the STN neurone activity while paired STN and GP recordings of tonic and bursting activity show no evidence of coherent activity. Thus, in a mouse brain slice preparation where functional GP-STN connectivity is preserved, no regenerative synaptically mediated activity indicative of a dynamic network is evident, either in the resting state or when neuronal bursting in both the GP and STN is generated by application of NMDA/apamin. This difference from the brain in Parkinson's disease may be attributed either to insufficient preservation of cortico-striato-pallidal or cortico-subthalamic circuitry, and/or an essential requirement for adaptive changes resulting from dopamine depletion for the expression of network activity within this tissue complex.
Assuntos
Potenciais de Ação/fisiologia , Globo Pálido/fisiologia , Rede Nervosa/fisiologia , Núcleo Subtalâmico/fisiologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Animais , Apamina/farmacologia , Estimulação Elétrica , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Globo Pálido/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Técnicas In Vitro , Lisina/análogos & derivados , Masculino , Camundongos , Camundongos Endogâmicos , N-Metilaspartato/farmacologia , Neurônios/fisiologia , Picrotoxina/farmacologia , Ácido gama-Aminobutírico/metabolismoRESUMO
In Parkinson's disease the neurones of the subthalamic nucleus show increased synchrony and oscillatory burst discharge, thought to reflect a breakdown of parallel processing in basal ganglia circuitry. To understand better the mechanisms underlying this transition, we sought to mimic this change in firing pattern within sagittal slices of rat midbrain. The firing patterns of up to four simultaneously extracellularly recorded subthalamic nucleus (STN) neurones were analysed using burst and oscillation detection programs, and correlated activity between pairs of neurones assessed. In control conditions all but 11 of 488 (2%) neurones fired in a predominantly tonic pattern (with mean oscillation frequency >3 Hz), with no significantly cross-correlated activity in any of 393 pairs of neurones. The glutamate antagonists DL-2-amino-phosphonopentanoic acid (APV), 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 6-methyl-2-(phenylethynyl)pyridine (MPEP) did not change the firing rate or pattern of these cells, providing no evidence for a role of glutamatergic collaterals within the STN under these conditions. The GABA(A) receptor antagonist bicuculline and GABA(B) receptor antagonist (2S)-3-[[(1S)-1-(3,4-dichlorophenyl)ethyl]amino-2-hydroxypropyl]phenylmethyl phosphinic acid (CGP 55845) were also without effect on firing rate or pattern in these cells, suggesting that there was no active input from other GABAergic basal ganglia nuclei in this slice. The dopamine receptor antagonist haloperidol caused no significant change to firing rate or pattern of firing in these cells, suggesting that there was no active dopaminergic input in this slice. Excitations of STN neurones by muscarine, (+)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (ACPD), N-methyl-D-aspartic acid (NMDA) or dopamine were all unaccompanied by a change in firing pattern or any significant correlated activity between STN neurone pairs. Burst firing could be induced in STN neurones with either the potassium channel blocker tetraethylammonium (TEA; 10 mM; in 100/138 [72%] of cells) or with a combination of NMDA and the calcium-activated potassium channel blocker apamin (in 101/216 [47%] of cells). Burst firing in TEA was unchanged by CNOX and APV, MPEP, CGP55845, haloperidol, dopamine, and ACPD, although muscarine produced a significant increase in oscillation frequency. Burst firing in NMDA and apamin was unchanged by CNQX and APV, dopamine, muscarine and ACPD, although bicuculline caused a significant increase in oscillation frequency. Such burst firing was not accompanied by synchrony in any condition, either alone, or during application of excitatory agents or glutamate or GABA antagonists. As the bursting seen here was unaccompanied by the synchronous activity that has often been observed (pathologically) in vivo, it probably reflects solely intrinsic STN neuronal properties, rather than network activity. No functional role was found for glutamatergic collaterals within the STN, either when cells are firing tonically or burst firing. The circuitry needed to produce synchrony in the STN is most likely not intrinsic to the STN itself, but requires connections with other basal ganglia nuclei, and/or the cortex, which are not present in this preparation.
Assuntos
Potenciais de Ação/fisiologia , Relógios Biológicos/fisiologia , Neurônios/fisiologia , Núcleo Subtalâmico/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Relógios Biológicos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Técnicas In Vitro , Masculino , N-Metilaspartato/farmacologia , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/fisiologia , Neurônios/efeitos dos fármacos , Ratos , Ratos Wistar , Núcleo Subtalâmico/efeitos dos fármacos , Tetraetilamônio/farmacologiaRESUMO
Sleep deprivation exerts antidepressant effects after only one night of deprivation, demonstrating that a rapid antidepressant response is possible. In this report we tested the hypothesis that total sleep deprivation induces an increase in extracellular serotonin (5-HT) levels in the hippocampus, a structure that has been proposed repeatedly to play a role in the pathophysiology of depression. Sleep deprivation was performed using the disk-over-water method. Extracellular levels of 5-HT were determined in 3 h periods with microdialysis and measured by high performance liquid chromatography coupled with electrochemical detection. Sleep deprivation induced an increase in 5-HT levels during the sleep deprivation day. During an additional sleep recovery day, 5-HT remained elevated even though rats displayed normal amounts of sleep. Stimulus control rats, which had been allowed to sleep, did not experience a significant increased in 5-HT levels, though they were exposed to a stressful situation similar to slee-deprived rats. These results are consistent with a role of 5-HT in the antidepressant effects of sleep deprivation.
Assuntos
Espaço Extracelular/metabolismo , Hipocampo/metabolismo , Serotonina/metabolismo , Privação do Sono/metabolismo , Análise de Variância , Animais , Cromatografia Líquida de Alta Pressão/métodos , Eletroquímica , Eletroencefalografia/métodos , Eletromiografia , Hipocampo/anatomia & histologia , Masculino , Microdiálise/métodos , Ratos , Ratos Sprague-Dawley , Fases do Sono/fisiologia , Estresse Fisiológico/metabolismo , Fatores de TempoRESUMO
The effect of magnetic fields on interictal firing rates was investigated in three epileptic patients with depth electrode implantation in the hippocampus for pre-surgical evaluation. The protocol consisted of 10 min test periods, during which magnetic fields were cycled for 1 min on and 1 min off, and intervening 5 min rest periods. Only one patient revealed a 95% significant increase in the 10 s after the fields were switched on compared with the background estimate from the 10s before the fields were applied. This patient was also the only patient to show significant increases in firing rates during field-on compared with field-off periods, and during magnetic field test periods compared with intervening rest periods. This patient had a right hippocampal seizure onset. All patients showed increased firing rates during the 10 min periods of magnetic field testing compared to the 5 min rest periods between tests. This result was significant for the group at the 99% level. Two patients with right temporal lobe onset showed greater activity in the right hippocampus than the left. All patients exhibited a progressive increase in firing rates in rest periods between tests.
Assuntos
Campos Eletromagnéticos , Epilepsia/fisiopatologia , Eletrodos Implantados , Eletroencefalografia/métodos , Fenômenos Eletromagnéticos , Potenciais Evocados/fisiologia , Feminino , Hipocampo/anatomia & histologia , Hipocampo/fisiopatologia , Humanos , Masculino , Fatores de TempoRESUMO
Serotonin is thought to be intimately involved in the regulation of sleep and waking in humans, though the evidence for such is indirect. Using in vivo microdialysis, the authors show that serotonin in human ventricular CSF covaries with the state of consciousness. They hypothesize that CSF serotonin may be acting in an endocrine-like manner through activation of known leptomeningeal serotonin receptors and possibly participating in modulation of choroidal production of CSF.
Assuntos
Ciclos de Atividade/fisiologia , Ventrículos Laterais/metabolismo , Serotonina/líquido cefalorraquidiano , Sono REM/fisiologia , Adulto , Eletroencefalografia/estatística & dados numéricos , Humanos , MasculinoRESUMO
Full-length cDNA clones of RNA viruses are advantageous for maintaining the genomic sequence without the generation of diversity by accumulation of sequence mutations during productive virus replication. They permit in vitro manipulation of the genomic clone to test the effect of sequence changes on the phenotype of reactivated virus. Infectious cDNA clones have been produced by ligation of subgenomic clones but are sometimes difficult to generate in a single cloning operation. We used reverse-transcription to synthesize full-length cDNA from genomic RNA of Coxsackievirus B3 of the Picornavirus family and enzymatically amplified this by long PCR. Five different cloning vectors were used to clone the long PCR product, including the vector Lorist6 which contains transcriptional terminators on either side of the cloning site to prevent transcription of inserts in E. coli. No recombinant colonies were obtained from any of the vectors lacking transcriptional terminators but three full-length clones were obtained using Lorist6. The results suggest that transcriptional terminators increase the recovery of cDNA clones of the 7.4 kb Coxsackie virus genome in this cosmid vector, without resort to phage packaging, representing an advance over previous methods and advantages in the molecular manipulation of these viruses.
Assuntos
Clonagem Molecular/métodos , Enterovirus Humano B/genética , Vetores Genéticos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Regiões Terminadoras Genéticas , Animais , Chlorocebus aethiops , DNA Complementar , Escherichia coli/genética , Células VeroRESUMO
Klippel-Trenaunay syndrome (KTS) is a congenital vascular anomaly characterized by limb hypertrophy, cutaneous hemangiomas, and varicosities. GI hemorrhage is a potentially serious complication secondary to diffuse hemangiomatous involvement of the gut. We report on three patients with KTS who presented with transfusion-dependent anemia and life-threatening bleeding due to extensive cavernous hemangiomas involving the rectum. Two patients were treated by proctocolectomy and coloanal anastomosis, which preserved anal function while controlling bleeding. The third patient required an abdominoperineal resection because of extensive rectal, perianal, and perineal angiomatosis. The literature on the evaluation and management of GI hemorrhage in KTS, particularly of colorectal origin, is reviewed.