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1.
Neurosurg Rev ; 47(1): 384, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39085721

RESUMO

"Low-lying" posterior communicating artery (PCoA) aneurysms require great attention in surgical clipping due to their distinct anatomical characteristics. In this study, we propose an easy method to immediately recognize "low-lying" PCoA aneurysms in neurosurgical practice. A total of 89 cases with "low-lying" PCoA aneurysms were retrospectively analyzed. All patients underwent preoperative digital subtraction angiography (DSA) examinations and microsurgical clipping. Cases were classified into the "low-lying" and regular groups based on intraoperative findings. The distance- and angle-relevant parameters that reflected the relative location of the aneurysms and tortuosity of the internal carotid artery were measured using 3D-DSA images. The data were sequentially integrated into a mathematical analysis to obtain the prediction model. Finally, we proposed a novel mathematical formula to preoperatively predict the existence of "low-lying" PCoA aneurysms with great accuracy. Neurosurgeons might benefit from this model, which enables them to directly identify "low-lying" PCoA aneurysms and make appropriate surgical decisions accordingly.


Assuntos
Angiografia Digital , Aneurisma Intracraniano , Procedimentos Neurocirúrgicos , Humanos , Aneurisma Intracraniano/cirurgia , Aneurisma Intracraniano/diagnóstico por imagem , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Angiografia Digital/métodos , Procedimentos Neurocirúrgicos/métodos , Estudos Retrospectivos , Idoso , Angiografia Cerebral/métodos , Modelos Teóricos , Artéria Carótida Interna/cirurgia , Artéria Carótida Interna/diagnóstico por imagem
2.
Analyst ; 147(22): 5054-5061, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36197707

RESUMO

Exosomes are considered as potential biomarkers that can reflect information from their parent cell-associated cancer microenvironment. Recently, aptasensors have been widely used for cancer and tumor exosome detection. Aptamers related to exosome surface proteins are usually used to introduce a sequence; the aptamer is used for exosome recognition, and the introduced sequence is used to form G-quadruplexes and for signal amplification. In this paper, we found that the EpCAM aptamer is rich in guanine and unimolecular G-quadruplex with a two-layer G-tetrad under acidic conditions, and we investigated its topology, thermal stability and dissociation constant with hemin. Based on this, our proposed colorimetric aptamer sensor combines the unmodified EpCAM aptamer with hemin to construct a hemin/G-quadruplex DNAzyme and catalyze the TMB-H2O2 system to generate a strong colorimetric signal. Therefore, colorimetric signal changes were negatively correlated with the exosome concentration. The linear range of the 1 h assay was 106-108 particles per mL, and the detection limit was 3.94 × 105 particles per mL. In addition, this method can detect exosomes in complex fetal bovine serum samples with good specificity and high sensitivity toward exosomes from breast, liver, and lung cancers with abnormal EpCAM protein expression.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , DNA Catalítico , Exossomos , Quadruplex G , DNA Catalítico/genética , Hemina/metabolismo , Colorimetria/métodos , Exossomos/metabolismo , Peróxido de Hidrogênio/metabolismo , Molécula de Adesão da Célula Epitelial , Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/métodos , Limite de Detecção
3.
BMC Endocr Disord ; 21(1): 123, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34134685

RESUMO

BACKGROUND: Diabetes is a well-known risk factor for tuberculosis and poorly glycemic control may increase the risk of tuberculosis. We performed a meta-analysis to explore the association of glycemic control in diabetic patients and their tuberculosis prevalence. METHODS: We included observational studies that investigated the prevalence of tuberculosis associated with glycemic control. The markers of glycated hemoglobin A1c (HbA1c) and fasting plasma glucose were used to evaluate the exposure of interest in the study. We searched related articles in PubMed, EMBASE and Web of Science through 14 December 2019. The Newcastle-Ottawa scale was used to assess the risk of bias of included studies. RESULTS: Seventeen studies (four cohort studies, five case-control studies and eight cross-sectional studies) were included, involving 1,027,074 participants. The meta-analysis found the pooled odds ratio of prevalent tuberculosis increased a 2.05-fold (95%CI: 1.65, 2.55) for the patients with HbA1c ≥7.0% compared to those with HbA1c concentration < 7.0%. Furthermore, we found the mean of HbA1c was higher in the diabetes mellitus with tuberculosis group than the diabetes-only group (P = 0.002). In the sensitivity analysis, the finding remains consistent. CONCLUSION: Our study provides the evidence that poorly controlled diabetes in diabetics may be associated with increased prevalence of tuberculosis. More efforts should focus on screening tuberculosis in uncontrolled diabetes.


Assuntos
Biomarcadores/sangue , Complicações do Diabetes/epidemiologia , Diabetes Mellitus/fisiopatologia , Tuberculose/epidemiologia , Glicemia/análise , Complicações do Diabetes/sangue , Complicações do Diabetes/diagnóstico , Hemoglobinas Glicadas/análise , Humanos , Prognóstico , Fatores de Risco , Tuberculose/sangue , Tuberculose/diagnóstico
4.
JMIR Public Health Surveill ; 10: e53948, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38564244

RESUMO

BACKGROUND: Diabetes mellitus (DM) increases the risk of developing tuberculosis (TB), and optimal glycemic control has been shown to reduce the risk of complications and improve the TB treatment outcomes in patients with DM. OBJECTIVE: This study aims to investigate the role of glycemic control in improving TB treatment outcomes among patients with DM. METHODS: MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials (RCTs) assessing the impact of oral glycemic control in patients with TB who have DM. Outcomes of interest were radiological findings, treatment success, sputum positivity, and mortality. Evaluations were reported as risk ratios (RRs) with 95% CIs using weighted random-effects models. RESULTS: The analysis included 6919 patients from 7 observational studies. Our meta-analysis showed significant differences between patients with optimal glycemic control and those with poor glycemic control with regard to improved treatment outcomes (RR 1.13, 95% CI 1.02-1.25; P=.02; I²=65%), reduced sputum positivity (RR 0.23, 95% CI 0.09-0.61; P=.003; I²=66%), and fewer cavitary lesions (RR 0.59, 95% CI 0.51-0.68; P<.001; I²=0%) in radiological findings. There was no significant difference between the 2 groups in terms of mortality (RR 0.57, 95% CI 0.22-1.49; P=.25; I²=0%), multilobar involvement (RR 0.57, 95% CI 0.22-1.49; P=.25; I²=0%) on radiologic examination, and upper lobe (RR 0.94, 95% CI 0.76-1.17; P=.58; I²=0%) and lower lobe (RR 1.05, 95% CI 0.48-2.30; P=.91; I²=75%) involvement on radiologic examination. CONCLUSIONS: We concluded that optimal glycemic control is crucial for reducing susceptibility, minimizing complications, and improving treatment outcomes in patients with TB with DM. Emphasizing effective health management and health care strategies are essential in achieving this control. Integrating comprehensive care among patients with TB with DM will enhance patient outcomes and alleviate the burden of disease in this population. TRIAL REGISTRATION: PROSPERO CRD42023427362; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=427362.


Assuntos
Diabetes Mellitus , Controle Glicêmico , Tuberculose , Humanos , Tuberculose/complicações , Tuberculose/tratamento farmacológico , Controle Glicêmico/métodos , Controle Glicêmico/estatística & dados numéricos , Resultado do Tratamento , Diabetes Mellitus/epidemiologia , Complicações do Diabetes , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Front Immunol ; 15: 1401867, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38846947

RESUMO

Tuberculosis (TB), caused by the bacterial pathogen Mycobacterium tuberculosis (MTB), remains one of the most prevalent and deadly infectious diseases worldwide. Currently, there are complex interactions between host cells and pathogens in TB. The onset, progression, and regression of TB are correlated not only with the virulence of MTB but also with the immunity of TB patients. Exosomes are cell-secreted membrane-bound nanovesicles with lipid bilayers that contain a variety of biomolecules, such as metabolites, lipids, proteins, and nucleic acids. Exosome-mediated cell-cell communication and interactions with the microenvironment represent crucial mechanisms through which exosomes exert their functional effects. Exosomes harbor a wide range of regulatory roles in physiological and pathological conditions, including MTB infection. Exosomes can regulate the immune response, metabolism, and cellular death to remodel the progression of MTB infection. During MTB infection, exosomes display distinctive profiles and quantities that may act as diagnostic biomarkers, suggesting that exosomes provide a revealing glimpse into the evolving landscape of MTB infections. Furthermore, exosomes derived from MTB and mesenchymal stem cells can be harnessed as vaccine platforms and drug delivery vehicles for the precise targeting and treatment of TB. In this review, we highlight the functions and mechanisms through which exosomes influence the progression of TB. Additionally, we unravel the critical significance of exosomal constituents in the diagnosis and therapeutic applications of TB, aiming to offer novel perspectives and strategies for combating TB.


Assuntos
Biomarcadores , Exossomos , Mycobacterium tuberculosis , Tuberculose , Exossomos/imunologia , Exossomos/metabolismo , Humanos , Tuberculose/imunologia , Tuberculose/diagnóstico , Tuberculose/terapia , Tuberculose/microbiologia , Mycobacterium tuberculosis/imunologia , Animais , Antituberculosos/uso terapêutico
6.
Front Immunol ; 14: 1305325, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38259491

RESUMO

Tuberculosis (TB) is caused by the bacterial pathogen Mycobacterium tuberculosis (MTB) and is one of the principal reasons for mortality and morbidity worldwide. Currently, recommended anti-tuberculosis drugs include isoniazid, rifampicin, ethambutol, and pyrazinamide. TB treatment is lengthy and inflicted with severe side-effects, including reduced patient compliance with treatment and promotion of drug-resistant strains. TB is also prone to other concomitant diseases such as diabetes and HIV. These drug-resistant and complex co-morbid characteristics increase the complexity of treating MTB. Host-directed therapy (HDT), which effectively eliminates MTB and minimizes inflammatory tissue damage, primarily by targeting the immune system, is currently an attractive complementary approach. The drugs used for HDT are repositioned drugs in actual clinical practice with relative safety and efficacy assurance. HDT is a potentially effective therapeutic intervention for the treatment of MTB and diabetic MTB, and can compensate for the shortcomings of current TB therapies, including the reduction of drug resistance and modulation of immune response. Here, we summarize the state-of-the-art roles and mechanisms of HDT in immune modulation and treatment of MTB, with a special focus on the role of HDT in diabetic MTB, to emphasize the potential of HDT in controlling MTB infection.


Assuntos
Diabetes Mellitus , Tuberculose , Humanos , Tuberculose/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico , Antituberculosos/uso terapêutico , Etambutol , Isoniazida
7.
J Chromatogr A ; 1661: 462680, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34879311

RESUMO

As metabolites of the gut microbiome, short-chain fatty acids (SCFAs) played an important role in the diagnosis of the metabolic diseases. Because of the high polarity, high volatility and complex matrix of biological samples, the highly sensitive, selective and accurate method to determine SCFAs remains a major challenge. Herein, a new method for simultaneous quantification of eleven SCFAs by derivatization combined with solid phase microextraction (SPME) and gas chromatography tandem mass spectrometry (GC-MS/MS) was developed. Isobutyl chloroformate coupled with isobutanol was used as the reaction reagent to derivatize SCFAs. The method validation data showed a satisfactory linearity with the linear regression coefficients (R) ranging from 0.9964 to 0.9996. The limit of detection (LOD) of all SCFAs ranges from 0.01 ng·mL-1 to 0.72 ng·mL-1 and the limit of quantification (LOQ) ranges from 0.04 ng·mL-1 to 2.41 ng·mL-1. The intra-day and inter-day precision (RSDs) ranged from 0.65% to 8.92% and 1.62% to 15.61%, respectively. The recovery ranged from 88.10% to 108.71%. Finally, the developed method was successfully used to determine SCFAs in mice fecal sample, and ten of the SCFAs were found in feces of mice, including formic acid.


Assuntos
Microextração em Fase Sólida , Espectrometria de Massas em Tandem , Animais , Ácidos Graxos Voláteis , Fezes , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Camundongos
8.
J Chromatogr A ; 1663: 462750, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-34942488

RESUMO

A simple and efficient dispersive solid-phase extraction (D-SPE) method combined with gas chromatography tandem mass spectrometry (GC-MS/MS) was developed to determine organochlorine pesticides (OCP) in honey. Firstly, a type of hybrid nanocomposite (CD-MOF/TiO2) was prepared by grafting a metal-organic framework material synthesized with cyclodextrin as an organic ligand onto titanium dioxide. Then, the CD-MOF/TiO2 was used as a D-SPE adsorbent to extract the OCP, and the effects of the amount of adsorbent, ultrasonic time, vortex time, pH, and salinity on the extraction were investigated using Plackett-Burman design and Box-Behnken Design. Under the optimized adsorption and desorption conditions, an analysis method that combined D-SPE with GC-MS/MS was established. The linear ranges of 14 OCP are 1-500 µg kg-1 and the correlation coefficients are between 0.9991 and 1.000. The limits of detection and quantification vary from 0.01 to 0.04 µg kg-1 and 0.04 to 0.12 µg kg-1, respectively. The intra-day and inter-day precision of this method are suitable (RSDs% less than 11.3%). The established CD-MOF/TiO2 / D-SPE method was used for the extraction of OCP in honey samples with recovery in the range of 76.4 to 114.3%. The results demonstrate that the CD-MOF/TiO2 has a good selective enrichment ability for OCP and is suitable for the D-SPE pretreat of honey sample analysis.


Assuntos
Mel , Estruturas Metalorgânicas , Nanocompostos , Resíduos de Praguicidas , beta-Ciclodextrinas , Cromatografia Gasosa-Espectrometria de Massas , Mel/análise , Resíduos de Praguicidas/análise , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Titânio
9.
J Chromatogr A ; 1648: 462192, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-33984649

RESUMO

Determination of folic acid and riboflavin in biological samples is difficult due to their high polarity, low concentration, chemical instability, and complex matrix. In this study, the polypyrrole-coated magnetic nanocomposite (Fe3O4@PPy) was synthesized innovatively with the assistance of hexadecyltrimethylammonium bromide. To evaluate the adsorption mechanism and the feasibility of synthesized Fe3O4@PPy as an adsorbent, the adsorption capacities, kinetics and thermodynamics of folic acid and riboflavin were investigated systemically. Furthermore, in light of the chemical instability of folic acid and riboflavin a method for rapid extraction and detection of them from human urine within 10 min was developed successfully by combining magnetic solid phase extraction with ultra-performance liquid chromatography (MSPE/UPLC). The adsorption parameters including sorbent amount, pH value, extraction time, desorption solvent and desorption time were studied. Under optimum conditions, the performance of the established determination method was validated with the linearly dependent coefficients (>0.9995), the limits of detection (0.02-0.05 µg/mL), the limits of quantification (0.07-0.18 µg/mL), and the recoveries (92.2-105.1%, with relative standard deviation < 3.3%). The rapid extraction and detection of folic acid and riboflavin from real urine samples were achieved subsequently. The present study suggests that the developed method exhibits a promising application in the analysis of free folic acid and riboflavin in human urine samples, which can provide a reference for the clinical drug monitoring and treatment.


Assuntos
Cromatografia Líquida/métodos , Ácido Fólico/urina , Magnetismo/métodos , Polímeros/química , Pirróis/química , Riboflavina/urina , Extração em Fase Sólida/métodos , Adsorção , Humanos , Limite de Detecção , Nanocompostos/química , Solventes/química
10.
Acta Trop ; 224: 106073, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34487719

RESUMO

In western societies, the prevalence of type 2 diabetes (T2D) is related to the hygiene hypothesis, which implies that reduced exposure to infectious factors results in a loss of the immune stimulation necessary to form the immune system during development. In fact, it has been reported that parasites, such as Schistosoma, can improve or prevent the development of T2D, which may be related to the activity of immune cells, including regulatory T cells (Tregs). Hence, Schistosoma, Tregs, and T2D share a close relationship. Schistosoma infection and the molecules released can lead to an increase in Tregs, which play an important role in the suppression of T2D. In this review, we provide an overview of the role of Tregs in the response to Schistosoma infection and the protective mechanism of Schistosoma-related molecular products against T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Linfócitos T Reguladores , Animais , Diabetes Mellitus Tipo 2/prevenção & controle , Schistosoma
11.
J Med Invest ; 54(3-4): 322-30, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17878682

RESUMO

The present study was designed to present evidence to clarify the relationships between learning ability, neuronal cell adhesion molecule L1 expression and hippocampal structural changes in the rat model received X-irradiation at an embryonic stage (E15). Water maze task indicated that all of the irradiated rats failed to learn the task in the whole training procedure. Their latency to the platform and swimming distance were significant differences from those sham-treated controls. Histological studies showed that the hippocampal ectopias induced by X-rays in the CA1 were involved in the spatial learning impairment, in which they hampered normal processes in learning development and transmission of information. Number, size and positions of the ectopias in the dorsal parts of the hippocampus were confirmed to be related to degrees of spatial learning impairment. On the other hand, L1 expression in the hippocampus was examined with Western blot analysis. The results indicated a lower content of L1 in the irradiated rats. A decrease in L1 might be one of reasons to cause disorganization of the septohippocampal pathways. These findings suggest some mechanisms of spatial learning impairment can be attributed to the formation of the hippocampal ectopias and redaction of L1 following prenatal exposure to X-irradiation.


Assuntos
Aprendizagem em Labirinto/fisiologia , Aprendizagem em Labirinto/efeitos da radiação , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Animais , Feminino , Hipocampo/embriologia , Hipocampo/patologia , Hipocampo/fisiologia , Hipocampo/efeitos da radiação , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar
12.
Int J Biol Macromol ; 94(Pt A): 451-458, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27765573

RESUMO

A water-soluble polysaccharide (STPC2) was isolated from the boiling-water extract of Sargassum thunbergii, purified by CaCl2 precipitation and chromatography on DEAE-cellulose and Sephacryl S-300 column. It was found that STPC2, with a molecular weight of 57kD, was composed of fucose, xylose, galactose and glucuronic acid, in a ratio of 8.1: 3.8: 2.1: 1.0. Additionally, we found that STPC2 significantly inhibited endothelial cell migration and tube formation without toxicity. Moreover, STPC2 significantly inhibited lung cancer cell A549 migration and proliferation. It was found that STPC2 treatment suppressed MMP-2 gene expression at transcriptional level and enzymatic activity. Furthermore, STPC2 reduced the mRNA and protein expression of vascular endothelial growth factor-A (VEGF-A) and hypoxia-inducible factor (HIF)-1 alpha in the endothelial cells. Taken together, our findings indicated that STPC2 was a potent bioactive polysaccharide with distinct anti-angiogenesis activity against tumor migration via down-regulation of MMP-2 activity and VEGF/HIF-1α signaling pathway.


Assuntos
Inibidores da Angiogênese/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Polissacarídeos/farmacologia , Células A549 , Inibidores da Angiogênese/química , Inibidores da Angiogênese/isolamento & purificação , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Regulação para Baixo , Ensaios de Seleção de Medicamentos Antitumorais , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Sargassum/química , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/fisiologia
13.
J Med Invest ; 49(1-2): 35-9, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11901757

RESUMO

Distribution of calbindin-D28K immunoreactive cells in the primary motor area of the adult rat neocortex was studied in the present experiment. In the primary motor cortex, calbindin-D28K immunoreactivity was found in two populations of cortical neurons. One was composed of neurons heavily labeled with anti-calbindin antibody, which were present in two bands corresponding to cortical layers II-III, and V. The morphological types of these cells were varied; they had oval, fusiform or mutiangular somata. The proximal dendrites of the heavily stained cells showed that these cells were non-pyramidal neurons, and they were either bitufted or multipolar cells. The other was a weakly stained population, mainly concentrated in layers II and III, that also contained pyramidal neurons. In addition, one outstanding feature of the neuropil staining deep to layer II was the labeling of the long, vertically oriented bundles of immunoreactive processes. Such a distinct pattern of calbindin-D28K immunoreactive neurons in the primary motor cortex suggests a relatively high density of calcium channels exists in the superficial layers of the rat primary motor cortex.


Assuntos
Córtex Motor/citologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Animais , Calbindina 1 , Calbindinas , Imuno-Histoquímica , Masculino , Córtex Motor/metabolismo , Especificidade de Órgãos , Ratos , Ratos Wistar
14.
J Med Invest ; 50(3-4): 187-91, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-13678389

RESUMO

To gain insight to the cellular and molecular mechanisms involved abnormal neuronal migration induced by irradiation, we investigated expression of neuronal cell adhesion molecule L1 and neuronal migration in the brains through comparison between rats prenatally exposed to X-ray and controls. To observe the pattern of neuronal migration, bromodeoxyuridine (BrdU) was chosen as a marker to label migrating cells. The results showed some of the labeled cells remained in the lower of the cortical plate in the irradiated rats, suggesting that neuronal migration was disrupted by X-ray. To study change of expressing neural cell molecule L1, rat brains were analyzed by SDS-PAGE after isolation of L1 by immunoaffinity chromatography. In the all brain membrane fraction, immunoaffinity purified L1 had bands at 200, 180, 140 and 80 kDa. However, the bands in the irradiated group were very weak when compared with the control. Taking these results into account, abnormal neuronal migration and reduction of expression L1 found in the irradiated brain indicated that migration of neural cells may be largely dependent on radial glial fiber as well as neural cell molecules like L1. A decrease in L1 expression may be one of reasons of abnormal neuronal migration.


Assuntos
Encéfalo/metabolismo , Movimento Celular/efeitos da radiação , Exposição Materna , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Irradiação Corporal Total/efeitos adversos , Animais , Encéfalo/citologia , Feminino , Masculino , Neurônios/efeitos da radiação , Gravidez , Ratos , Ratos Wistar , Raios X
15.
J Med Invest ; 51(1-2): 103-7, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15000263

RESUMO

Heavy-ion beams have the feature to administer a large radiation dose in the vicinity of the endpoint in the beam range, its irradiation system and biophysical characteristics are different from ordinary irradiation instruments like X-rays or gamma-rays. In order to get clarify characteristic effects of heavy-ion beams on the brain, we have developed an experimental system for irradiating a restricted region of the rat brain using heavy-ion beams. The left cerebral hemispheres of the adult rat brain were irradiated at dose of 50 Gy charged carbon particles (290 MeV/nucleon; 5 mm spread-out Bragg peak). After irradiation, the characteristics of the heavy-ion beams and the animal model were studied. Histological examination and measurement showed that extensive necrosis was observed between 2.5 mm and 7.5 mm depth from the surface of the rat head, suggesting a relatively high dose and uniform dose was delivered among designed depths and the spread-out Bragg peak used here successfully and satisfactorily retained its high-dose localization in the defined region. We believe that our experimental model for irradiating a restricted region of the rat brain using heavy-ion beams is a good model for analyzing regional radiation susceptibility of the brain.


Assuntos
Encéfalo/efeitos da radiação , Animais , Encéfalo/patologia , Íons Pesados , Masculino , Modelos Animais , Doses de Radiação , Tolerância a Radiação , Ratos , Ratos Sprague-Dawley
16.
J Med Invest ; 49(3-4): 97-110, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12323012

RESUMO

Neuronal migration is the critical cellular process which initiates histogenesis of cerebral cortex. Migration involves a series of complex cell interactions and transformation. After completing their final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. This process is guided by radial glial fibers, requires proper receptors, ligands, other unknown extracellular factors, and local signaling to stop neuronal migration. This process is also highly sensitive to various physical, chemical and biological agents as well as to genetic mutations. Any disturbance of the normal process may result in neuronal migration disorder. Such neuronal migration disorder is believed as major cause of both gross brain malformation and more special cerebral structural and functional abnormalities in experimental animals and in humans. An increasing number of instructive studies on experimental models and several genetic model systems of neuronal migration disorder have established the foundation of cortex formation and provided deeper insights into the genetic and molecular mechanisms underlying normal and abnormal neuronal migration.


Assuntos
Movimento Celular , Córtex Cerebral/citologia , Citocinas , Neurônios/citologia , 1-Alquil-2-acetilglicerofosfocolina Esterase , Animais , Biomarcadores , Proteínas de Transporte/análise , Moléculas de Adesão Celular Neuronais/deficiência , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/fisiologia , Córtex Cerebral/anormalidades , Córtex Cerebral/embriologia , Córtex Cerebral/crescimento & desenvolvimento , Proteínas da Matriz Extracelular/deficiência , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/fisiologia , Feminino , Humanos , Masculino , Mamíferos/anatomia & histologia , Mamíferos/embriologia , Camundongos , Camundongos Mutantes Neurológicos , Microcefalia/genética , Microcefalia/patologia , Proteínas Associadas aos Microtúbulos/deficiência , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/fisiologia , Midkina , Modelos Animais , Morfogênese , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Neuroglia/fisiologia , Gravidez , Ratos , Proteína Reelina , Serina Endopeptidases , Síndrome , Teratogênicos/toxicidade , Cromossomo X/genética , Síndrome de Zellweger/genética , Síndrome de Zellweger/patologia
17.
J Radiat Res ; 45(4): 563-9, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15635267

RESUMO

The relationship between an impairment of spatial navigation and an incidence of ectopic neurons in the dorsal hippocampus was investigated in adult rats that were prenatally exposed to X-ray irradiation. Adult rats which had received 1.5 Gy X-rays at embryonic day 15 (E15) showed significant learning disability in the water-maze task. According to the mean value of the swimming time, we categorized the irradiated adult rats into the following three groups: slightly damaged group, mildly damaged group and severely damaged group. No significant difference in the brain weight was found between the three categorized groups. Ectopic neurons appearing at abnormal places were prominently observed in the dorsal hippocampus of the severely damaged group with a remarkable learning disturbance, while no ectopia in the hippocampus was observed in the slightly damaged group. This may suggest that the cognitive dysfunction induced by prenatal exposure to X-ray irradiation may be, at least in part, attributable to ectopic neurons of the hippocampus.


Assuntos
Hipocampo/metabolismo , Hipocampo/efeitos da radiação , Exposição Materna , Neurônios/metabolismo , Animais , Encéfalo/patologia , Feminino , Hipocampo/patologia , Deficiências da Aprendizagem/etiologia , Masculino , Aprendizagem em Labirinto , Gravidez , Prenhez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar , Percepção Espacial , Fatores de Tempo , Distribuição Tecidual , Raios X
18.
J Radiat Res ; 43(2): 143-52, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12238328

RESUMO

The left cerebral hemispheres of adult Sprague-Dawley rat brains were irradiated at doses of 30, 50, or 100 Gy with charged carbon particles (290 MeV/nucleon; 5 mm spread-out Bragg peak). The spread-out Bragg peak used here successfully and satisfactorily retained its high-dose localization in the defined region. A histological examination showed that necrotic tissue damage, hemorrhage in the thalamus, and vasodilatations around the necrotic region were induced at 8 weeks after 100 Gy irradiation. The regions with tissue damage correlated well with those expected from the radiation-dose distribution, indicating an advantage of charged carbon particles for irradiating restricted brain regions. An X-ray fluorescent analysis demonstrated a decrease in the concentrations of K and P, and an increase in the concentrations of Cl, Fe, Zn in the damaged region at 8 weeks post-irradiation, though no significant changes were observed before 4 weeks of post-irradiation. This may indicate that even the very high radiation doses used here did not induce acute and immediate neuronal cell death, in contrast with ischemic brain injury where acute neuronal cell death occurred and the elemental concentrations changed within a day after the induction of ischemia.


Assuntos
Encéfalo/metabolismo , Encéfalo/efeitos da radiação , Carbono , Lesões por Radiação/metabolismo , Lesões por Radiação/patologia , Animais , Encéfalo/patologia , Íons , Masculino , Ratos , Ratos Sprague-Dawley , Raios X
19.
J Radiat Res ; 43(1): 89-98, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12056333

RESUMO

The types and three-dimensional distribution of neocortical ectopias following prenatal exposure to X-irradiation were studied by a histological examination and computer reconstruction techniques. Pregnant ICR mice were subjected to X-irradiation at a dose of 1.5 Gy on embryonic day 13. The brains from 30-day-old mice were serially sectioned on the frontal plane at 15 microns, stained with HE and observed with a microscope. The image data for the sections were input to a computer, and then reconstructed to three-dimensional brain structures using the Magellan 3.6 program. Sectional images were then drawn on a computer display at 240 microns intervals, and the positions of the different types of neocortical ectopias were marked using color coding. Three types of neocortical ectopias were recognized in the irradiated brains. Neocortical Lay I ectopias were identified as small patches in the caudal occipital cortex, and were located more laterally in the neocortex in caudal sections than in the rostral sections. Periventricular ectopias were located more rostrally than Lay I ectopias, and were found from the most caudal extent of the presumed motor cortex to the most caudal extent of the lateral ventricle. Hippocampal ectopias appeared as continuous linear bands, and were frequently associated with the anterior parts of the periventricular ectopias.


Assuntos
Encéfalo/anormalidades , Encéfalo/efeitos da radiação , Animais , Encéfalo/embriologia , Feminino , Feto/efeitos da radiação , Processamento de Imagem Assistida por Computador , Camundongos , Camundongos Endogâmicos ICR , Neocórtex/anormalidades , Neocórtex/embriologia , Neocórtex/efeitos da radiação , Gravidez , Lesões por Radiação/patologia
20.
J Radiat Res ; 43(3): 277-82, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12518987

RESUMO

To elucidate the mechanisms involved in deleterious neuronal and behavioral changes after prenatal ionizing irradiation, in vitro muscarinic acetylcholine (mACh) receptor binding and histological construction were investigated in 9-week old rat brains after 1.5 Gy X-ray exposure on embryonic day 15 (E15). A gross anatomical examination with a magnetic-resonance imaging system showed an irregular tissue construction in the hippocampus and cortex of the irradiated rat brain. Histological sections stained with hematoxylin and eosin also indicated that the structures of the hippocampus and cortex were obviously changed. In irradiated rats, the laminar structure of pyramidal cells was selectively deranged in the CA1 region. In vitro 3H-Quinuclidinyl benzilate binding in the hippocampus was significantly decreased (about 10%) in prenatal irradiated rats compared to that in sham-treated rats. On the other hand, no significant change in mACh receptor binding was observed in the cerebral cortex. The present study revealed that prenatal exposure to ionizing radiation may induce dysfunction of the cholinergic neuronal systems, especially in the hippocampus, resulting in deleterious changes in memory and behavior.


Assuntos
Encéfalo/metabolismo , Encéfalo/efeitos da radiação , Antagonistas Muscarínicos/metabolismo , Efeitos Tardios da Exposição Pré-Natal , Quinuclidinil Benzilato/metabolismo , Animais , Feminino , Imageamento por Ressonância Magnética , Masculino , Gravidez , Ratos , Ratos Wistar , Trítio
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