RESUMO
Weather radiosondes play a crucial role in gathering atmospheric data for weather modeling and forecasting. However, their impact on marine wildlife, particularly seabirds, has raised concerns regarding the potential threats posed by these instruments. This study aims to assess the adverse effects of weather balloons on albatrosses, with a focus on the Southwest Atlantic region. The research reveals seven cases of entanglement of radiosonde equipment, leading to severe injuries and mortality along the Southern and Southeastern coasts of Brazil. Recommendations for mitigating the environmental impact of weather balloons include the adoption of biodegradable materials in their design and the implementation of improved retrieval protocols. Furthermore, the study stresses the importance of continued monitoring and research to address the interaction of weather radiosondes with marine animals. This approach is vital for ensuring the sustainable collection of scientific data while minimizing harm to marine life and ecosystems.
Assuntos
Aves , Ecossistema , Animais , Brasil , Tempo (Meteorologia) , Animais Selvagens , Monitoramento AmbientalRESUMO
Amyotrophic lateral sclerosis 2 (ALS2) is an autosomal recessive form of juvenile ALS and has been mapped to human chromosome 2q33. Here we report the identification of two independent deletion mutations linked to ALS2 in the coding exons of the new gene ALS2. These deletion mutations result in frameshifts that generate premature stop codons. ALS2 is expressed in various tissues and cells, including neurons throughout the brain and spinal cord, and encodes a protein containing multiple domains that have homology to RanGEF as well as RhoGEF. Deletion mutations are predicted to cause a loss of protein function, providing strong evidence that ALS2 is the causative gene underlying this form of ALS.
Assuntos
Esclerose Lateral Amiotrófica/genética , GTP Fosfo-Hidrolases/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Mutação , Sequência de Aminoácidos , Animais , Mapeamento Cromossômico , Cromossomos Humanos Par 2 , Feminino , Fatores de Troca do Nucleotídeo Guanina/química , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Polimorfismo Genético , Homologia de Sequência de AminoácidosRESUMO
We developed a simple genotyping method for Flavobacterium psychrophilum for analysing two single nucleotide polymorphisms (SNPs) in the gyrA gene and to distinguish between isolates that are virulent and avirulent to ayu, Plecoglossus altivelis altivelis (Temminck & Schlegel). The genotyping method is an on/off switch assay and is based on the polymerase chain reaction technique with phosphorothioated primers. We classified 232 isolates from four families of fish (i.e. Plecoglossidae, Osmeridae, Cyprinidae and Salmonidae) into four genotypes (G-C, A-T, A-C and G-T). The G-C type isolates exhibited strong pathogenicity to ayu, whereas the A-T and G-T types did not show any pathogenicity to this species. The A-C type exhibited no or weak pathogenicity to ayu. These results indicate that genotyping F. psychrophilum isolates with two SNPs from gyrA can clearly distinguish between isolates potentially harmful to ayu (G-C type) and those that are potentially not harmful or less harmful (A-C, A-T and G-T type). The on/off switch assay provides a quick, simple, and very powerful DNA genotyping technique for F. psychrophilum isolates.
Assuntos
Doenças dos Peixes/microbiologia , Infecções por Flavobacteriaceae/veterinária , Flavobacterium/genética , Flavobacterium/patogenicidade , Técnicas de Genotipagem/veterinária , Osmeriformes , Animais , Sequência de Bases , DNA Girase/genética , Doenças dos Peixes/mortalidade , Infecções por Flavobacteriaceae/microbiologia , Infecções por Flavobacteriaceae/mortalidade , Flavobacterium/classificação , Japão , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Análise de Sobrevida , Virulência/genéticaRESUMO
BACKGROUND AND PURPOSE: MR imaging can reflect the pathologic progression of carcinoma ex pleomorphic adenoma (CXPA). This study aimed to identify the imaging findings related to extracapsular invasion of CXPA. Additionally, the pathologic background of these findings was investigated. MATERIALS AND METHODS: This retrospective study included 37 patients with histologically confirmed CXPA. Three radiologists independently evaluated whether the CXPA showed the following characteristic MR imaging findings: border, capsule, the corona sign on fat-saturated T2WI and contrast-enhanced fat-saturated T1WI, and the black ring sign. The corona sign appeared larger on fat-saturated and/or contrast-enhanced fat-saturated T1WI than on T1WI. The black ring sign was defined as an intratumoral nodule with a thick low-intensity rim on T2WI. Interreader agreement of the visual assessment was performed using κ analysis, and MR imaging and histopathologic findings were also correlated. Kaplan-Meier survival and the log-rank test were used to estimate the 3-year disease-free survival. RESULTS: MR imaging findings, especially peritumoral findings, showed a significant difference between invasive and noninvasive CXPA. The reliability was poor for the border and capsule. In contrast, it was good for the corona sign on fat-saturated and contrast-enhanced fat-saturated T1WI and the black ring sign. Pathologically, the corona sign reflected the invasiveness of the tumor and inflammatory cells, while the black ring sign reflected hyalinization or fibrosis. The corona sign also showed a significant difference in the 3-year disease-free survival. CONCLUSIONS: MR imaging findings, including the corona and black ring signs, reliably differentiated invasive and noninvasive CXPA. The corona sign can be used as a prognostic factor for CXPA.
Assuntos
Adenoma Pleomorfo , Carcinoma , Neoplasias das Glândulas Salivares , Humanos , Adenoma Pleomorfo/diagnóstico por imagem , Neoplasias das Glândulas Salivares/diagnóstico por imagem , Neoplasias das Glândulas Salivares/patologia , Estudos Retrospectivos , Reprodutibilidade dos Testes , Prognóstico , Imageamento por Ressonância Magnética , Carcinoma/diagnóstico por imagemRESUMO
We show here that transient forebrain ischemia selectively elevates levels of neuronal apoptosis inhibitory protein (NAIP) in rat neurons that are resistant to the injurious effects of this treatment. This observation suggests that increasing NAIP levels may confer protection against ischemic cell death. Consistent with this proposal, we demonstrate that two other treatments that increase neuronal NAIP levels, systemic administration of the bacterial alkaloid K252a and intracerebral injection of an adenovirus vector capable of overexpressing NAIP in vivo, reduce ischemic damage in the rat hippocampus. Taken together, these findings suggest that NAIP may play a key role in conferring resistance to ischemic damage and that treatments that elevate neuronal levels of this antiapoptotic protein may have utility in the treatment of stroke.
Assuntos
Hipocampo/lesões , Hipocampo/metabolismo , Ataque Isquêmico Transitório/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Adenoviridae/genética , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Carbazóis/administração & dosagem , Carbazóis/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Terapia Genética , Vetores Genéticos , Hipocampo/irrigação sanguínea , Alcaloides Indólicos , Ataque Isquêmico Transitório/patologia , Ataque Isquêmico Transitório/terapia , Masculino , Fatores de Crescimento Neural/administração & dosagem , Fatores de Crescimento Neural/uso terapêutico , Proteínas do Tecido Nervoso/genética , Proteína Inibidora de Apoptose Neuronal , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Ratos , Ratos WistarRESUMO
During a four month scholarly leave in United States of America, researchers designed a culturally appropriate prevention program for eating disorders (ED) for Brazilian adolescent girls. The program "Se Liga na Nutrição" was modeled on other effective programs identified in a research literature review and was carried out over eleven interactive sessions. It was positively received by the adolescents who suggested that it be part of school curricula. The girls reported that it helped them to develop critical thinking skills with regards to sociocultural norms about body image, food and eating practices.
Assuntos
Imagem Corporal , Comportamento Alimentar/psicologia , Transtornos da Alimentação e da Ingestão de Alimentos/prevenção & controle , Avaliação de Programas e Projetos de Saúde , Adolescente , Brasil , Criança , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Feminino , Humanos , Masculino , Projetos Piloto , Serviços de Saúde EscolarRESUMO
The Weyl semimetal (WSM), which hosts pairs of Weyl points and accompanying Berry curvature in momentum space near Fermi level, is expected to exhibit novel electromagnetic phenomena. Although the large optical/electronic responses such as nonlinear optical effects and intrinsic anomalous Hall effect (AHE) have recently been demonstrated indeed, the conclusive evidence for their topological origins has remained elusive. Here, we report the gigantic magneto-optical (MO) response arising from the topological electronic structure with intense Berry curvature in magnetic WSM Co3Sn2S2. The low-energy MO spectroscopy and the first-principles calculation reveal that the interband transitions on the nodal rings connected to the Weyl points show the resonance of the optical Hall conductivity and give rise to the giant intrinsic AHE in dc limit. The terahertz Faraday and infrared Kerr rotations are found to be remarkably enhanced by these resonances with topological electronic structures, demonstrating the novel low-energy optical response inherent to the magnetic WSM.
RESUMO
R2D5 is a mouse monoclonal antibody that labels rabbit olfactory receptor neurons. Immunoblot analysis showed that mAb R2D5 recognizes a 22-kD protein with apparent pI of 4.8, which is abundantly contained in the olfactory epithelium and the olfactory bulb. We isolated cDNA for R2D5 antigen and confirmed by Northern analysis and neuronal depletion technique that R2D5 antigen is expressed predominantly, but not exclusively, in olfactory receptor neurons. Analysis of the deduced primary structure revealed that R2D5 antigen consists of 189 amino acids with calculated M(r) of 20,864 and pI of 4.74, has three calcium-binding EF hands, and has possible phosphorylation sites for Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) and cAMP-dependent protein kinase (A kinase). Using the bacterially expressed protein, we directly examined the biochemical properties of R2D5 antigen. R2D5 antigen binds Ca2+ and undergoes a conformational change in a manner similar to calmodulin. R2D5 antigen is phosphorylated in vitro by CaM kinase II and A kinase at different sites, and 1.81 and 0.80 mol of Pi were maximally incorporated per mol of R2D5 antigen by CaM kinase II and A kinase, respectively. Detailed immunohistochemical study showed that R2D5 antigen is also expressed in a variety of ependymal cells in the rabbit central nervous system. Aside from ubiquitous calmodulin, R2D5 antigen is the first identified calcium-binding protein in olfactory receptor neurons that may modulate olfactory signal transduction. Furthermore our results indicate that olfactory receptor neurons and ependymal cells have certain signal transduction components in common, suggesting a novel physiological process in ependymal cells.
Assuntos
Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Neurônios Receptores Olfatórios/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Antígenos/imunologia , Antígenos/metabolismo , Sequência de Bases , Northern Blotting , Cálcio/metabolismo , Sistema Nervoso Central/metabolismo , Clonagem Molecular , DNA Complementar , Escherichia coli , Immunoblotting , Camundongos , Dados de Sequência Molecular , Especificidade de Órgãos/genética , RNA Mensageiro/biossíntese , Coelhos , Homologia de Sequência de AminoácidosRESUMO
AIMS: Diffuse large B-cell lymphoma (DLBCL) usually proliferates effacing lymph follicles. In occasional cases, tumour cells show an interfollicular pattern of proliferation preserving lymph follicles. The aim was to analyse clinicopathological findings in DLBCL showing an interfollicular pattern of proliferation to determine whether this type of lymphoma is a distinct entity of DLBCL. METHODS AND RESULTS: Clinicopathological findings in 12 cases of DLBCL showing an interfollicular pattern of proliferation [interfollicular group (IF)] were examined and compared with those in 30 cases of DLBCL with ordinary morphology [control group (CG)]. IF showed a significantly lower lactate dehydrogenase level and International Prognostic Index scores than CG (P = 0.023 and P < 0.01, respectively). The frequency of localized disease, clinical stage 1 and 2, in IF was higher than that in CG (P = 0.016). A morphologically polymorphous pattern of proliferation was found in seven of 12 cases (58.3%) in IF, which was higher than that in CG, five (16.7%) of 30 cases (P < 0.01). Clonality analysis with the polymerase chain reaction method revealed that all 11 IF cases examined showed a monoclonal pattern. Immunohistochemically, the majority (11 of 12) of IF cases showed a non-germinal centre B-cell phenotype and the frequency was higher than that in CG (P = 0.021). CONCLUSION: Diffuse large B-cell lymphoma with an interfollicular pattern of proliferation shows distinct clinical and pathological findings from ordinary DLBCL.
Assuntos
Linfoma Difuso de Grandes Células B/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Proliferação de Células , Feminino , Centro Germinativo/citologia , Humanos , Imuno-Histoquímica , Japão , L-Lactato Desidrogenase/metabolismo , Linfoma Difuso de Grandes Células B/diagnóstico , Masculino , Pessoa de Meia-Idade , Fenótipo , PrognósticoRESUMO
The 150-kD oxygen-regulated protein (ORP150) was initially characterized based on its selective expression in astrocytes subjected to oxygen deprivation (Kuwabara, K., M. Matsumoto, J. Ikeda, O. Hori, S. Ogawa, Y. Maeda, K. Kitagawa, N. Imuta, K. Kinoshita, D.M. Stern, et al. 1996. J. Biol. Chem. 279:5025-5032). We have found that exposure of cultured human aortic smooth muscle cells and mononuclear phagocytes (MPs) to hypoxia (pO2 approximately 12-14 torr) induces ORP150 transcripts and production of the antigen, whereas incubation with either hydrogen peroxide, sodium arsenite, heat shock, or 2-deoxyglucose was without effect. Tissue extracts prepared from human atherosclerotic lesions demonstrated expression of ORP150 mRNA and antigen, vs lack of ORP150 in samples from nonatherosclerotic areas. In situ hybridization using ORP150 riboprobes showed the mRNA to be predominantly [correction of predominately] present in macrophages in in atherosclerotic plaques. Furthermore, autoantibody to ORP150 was demonstrated in the serum of patients with severe atherosclerosis, consistent with inducible in vivo expression of ORP150. Introduction of antisense oligonucleotide for ORP150 selectively diminished hypoxia-mediated induction of ORP150 antigen and reduced the viability of hypoxic MPs, especially in the presence of modified (oxidized/acetylated) LDL. In support of a role for ORP150 in the MPs' response to the microenvironment of an atheroma, the presence of oxidized LDL enhanced by approximately 10-fold ORP150 expression in hypoxic cultures. These data indicate that cells of the atherosclerotic vessel wall express ORP150 as part of a protective mechanism, potentially triggered by local hypoxia/hypoxemia and augmented by modified lipoproteins. The presence of antibody to ORP150 in sera of patients with severe atherosclerosis emphasizes the possibility that ORP150 may be a marker of vascular pathology.
Assuntos
Arteriosclerose/metabolismo , Lipoproteínas LDL/farmacologia , Macrófagos/fisiologia , Proteínas/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Arteriosclerose/patologia , Hipóxia Celular , Células Cultivadas , Criança , Pré-Escolar , Proteínas de Choque Térmico HSP70 , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/metabolismo , Oligonucleotídeos Antissenso/farmacologia , Proteínas/análise , CoelhosRESUMO
Genetic and environmental factors are important in the pathogenesis of clinical and experimental chronic intestinal inflammation. We investigated the influence of normal luminal bacteria and several groups of selected bacterial strains on spontaneous gastrointestinal and systemic inflammation in HLA-B27 transgenic rats. Rats maintained germfree for 3-9 mo were compared with littermates conventionalized with specific pathogen-free bacteria. Subsequently, germfree transgenic rats were colonized with groups of five to eight bacteria that were either facultative or strictly anaerobic. Transgenic germfree rats had no gastroduodenitis, colitis, or arthritis, but developed epididymitis and dermatitis to the same degree as conventionalized rats. Colonic proinflammatory cytokine expression was increased in transgenic conventionalized rats but was undetectable in germfree and nontransgenic rats. Colitis progressively increased over the first 4 wk of bacterial exposure, then plateaued. Only transgenic rats colonized with defined bacterial cocktails which contained Bacteroides spp. had colitis and gastritis. Normal luminal bacteria predictably and uniformly induce chronic colonic, gastric and systemic inflammation in B27 transgenic F344 rats, but all bacterial species do not have equal activities.
Assuntos
Artrite/microbiologia , Bacteroides/patogenicidade , Colite/microbiologia , Gastrite/microbiologia , Antígeno HLA-B27/imunologia , Animais , Animais Geneticamente Modificados , Sequência de Bases , Doença Crônica , Citocinas/genética , Primers do DNA/química , Sistema Digestório/microbiologia , Expressão Gênica , Humanos , Dados de Sequência Molecular , RNA Mensageiro/genética , Ratos , Microglobulina beta-2/imunologiaRESUMO
CDCP1, a novel stem cell marker, is expressed in hematopoietic cell line K562 but not in Jurkat. When CDCP1 promoter was transfected exogenously, Jurkat showed comparable promoter activity with K562, suggesting that the factor to enhance transcription was present but interfered to function in Jurkat. The reporter assay and si-RNA-mediated knockdown experiment revealed that zfp67, a zinc-finger protein, enhanced CDCP1 transcription. Amount of zfp67 in Jurkat was comparable with K562, but chromatin immunoprecipitation showed that zfp67 bound to CDCP1 promoter in K562 but not in Jurkat. There are CpG sequences around the promoter of CDCP1, which were heavily methylated in Jurkat but not in K562. Addition of demethylating reagent to Jurkat induced CDCP1 expression, and increased the zfp67 binding to CDCP1 promoter. Among normal hematopoietic cells such as CD34+CD38- cells, lymphocytes and granulocytes, inverse correlation between proportion of methylated CpG sequences and CDCP1 expression level was found. Demethylation of CpG sequences in lymphocytes, in which CpG sequences were heavily methylated, induced CDCP1 expression and its expression level further increased through zfp67 overexpression. The methylation of DNA appeared to regulate the cell-type-specific expression of CDCP1 through the control of interaction between chromatin DNA and transcription factors.
Assuntos
Antígenos CD/metabolismo , Moléculas de Adesão Celular/metabolismo , Metilação de DNA , Células-Tronco Hematopoéticas/metabolismo , Proteínas de Neoplasias/metabolismo , Antígenos CD/genética , Antígenos de Neoplasias , Sequência de Bases , Biomarcadores/metabolismo , Moléculas de Adesão Celular/genética , Imunoprecipitação da Cromatina , Ilhas de CpG , Primers do DNA , Humanos , Células Jurkat , Células K562 , Proteínas de Neoplasias/genética , Regiões Promotoras Genéticas , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Several studies have shown that long-term right ventricular (RV) overload in animal models alters myocardial energy substrate metabolism. However, whether long-term RV volume overload alters this metabolism in the human is unclear. METHODS AND RESULTS: We performed positron emission tomography with [(18)F]fluorodeoxyglucose (FDG) and single-photon emission tomography (SPECT) with [(201)Tl]TlCl (Tl) and [(123)I]15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in 11 patients with atrial septal defect (ASD) and 11 control subjects. In the FDG study, we calculated myocardial metabolic rate of glucose (MMR) in interventricular septum (IVS) and left ventricular (LV) free wall. MMR was significantly increased in IVS compared with LV free wall in the ASD patients (420+/-35 versus 333+/-32 mol x kg(-1) x min(-1); P<0.05) but not in the control group (347+/-27 versus 357+/-25 mol x kg(-1) x min(-1)). In both ASD and control groups, SPECT count was not significantly different between IVS and LV free wall in Tl (ASD, 160+/-11 versus 177+/-12; control, 141+/-12 versus 157+/-14 counts per 15 minutes) and BMIPP studies (ASD, 203+/-14 versus 212+/-18; control, 162+/-16 versus 176+/-16 counts per 15 minutes). MMR in the IVS/LV free wall ratio in the ASD group significantly correlated with indices related to RV volume overload. CONCLUSIONS: Given the assumption that long-term RV volume overload did not affect the lumped constant, the present study suggests that, unlike myocardial perfusion or fatty acid analogue uptake, myocardial glucose utilization in IVS relative to LV free wall is increased in relation to long-term RV volume overload in patients with ASD.
Assuntos
Fluordesoxiglucose F18/farmacocinética , Comunicação Interatrial/metabolismo , Septos Cardíacos/metabolismo , Hiperemia/metabolismo , Miocárdio/metabolismo , Compostos Radiofarmacêuticos/farmacocinética , Função Ventricular Direita , Adulto , Cateterismo Cardíaco , Ecocardiografia , Feminino , Comunicação Interatrial/complicações , Comunicação Interatrial/diagnóstico , Humanos , Hiperemia/complicações , Hiperemia/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Tomografia Computadorizada de Emissão , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
OBJECTIVE: Anchoring cardiac myocytes to extracellular matrix, which is mediated mainly by integrins on their surfaces, is important for maintaining the architecture of myocardial tissues and transmitting mechanical force. We evaluated the expression of alpha integrin subunits on myocytes and the accumulation of interstitial collagen and fibronectin at acute and chronic stages after myocardial infarction. METHODS: Myocardial infarction was induced by ligation of left coronary arteries in rats. The expression of alpha 1, alpha 3 and alpha 5 integrin subunits, and accumulation of collagen and fibronectin were analyzed with immunohistochemistry or sirius-red staining. RESULTS: In hearts without infarction, moderate expression of the alpha 3 subunit and only slight expression of the alpha 5 subunit were observed on myocytes. In the first week after infarction, the alpha 1 subunit, collagen and fibronectin were increased only in the peri-infarcted area, while the alpha 5 subunit was increased both in peri-infarcted and non-infarcted areas. At day 42, the expression of the alpha 1 subunit and collagen were still increased, although the alpha 5 subunit and fibronectin were decreased. The expression of the alpha 3 subunit was not altered throughout the experimental period. CONCLUSION: These data suggest that integrin subunits play an important role in healing and remodeling processes after myocardial infarction.
Assuntos
Antígenos CD/metabolismo , Integrinas/metabolismo , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Animais , Antígenos CD/análise , Adesão Celular , Doença Crônica , Colágeno/análise , Colágeno/metabolismo , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Fibronectinas/análise , Fibronectinas/metabolismo , Imuno-Histoquímica , Integrina alfa1 , Integrina alfa3 , Integrina alfa5 , Integrinas/análise , Masculino , Miocárdio/química , Ratos , Ratos WistarRESUMO
The X-linked lymphoproliferative syndrome (XLP) is an inherited immuno-deficiency to Epstein-Barr virus infection that has been mapped to chromosome Xq25. Molecular analysis of XLP patients from ten different families identified a small interstitial constitutional deletion in 1 patient (XLP-D). This deletion, initially defined by a single marker, DF83, known to map to interval Xq24-q26.1, is nested within a previously reported and much larger deletion in another XLP patient (XLP-739). A cosmid minilibrary was constructed from a single mega-YAC and used to establish a contig encompassing the whole XLP-D deletion and a portion of the XLP-739 deletion. Based on this contig, the size of the XLP-D deletion can be estimated at 130 kb. The identification of this minimal deletion, within which at least a portion of the XLP gene is likely to reside, should greatly facilitate efforts in isolating the gene.
Assuntos
Transtornos Linfoproliferativos/genética , Mapeamento por Restrição , Cromossomo X , Adolescente , Linhagem Celular , Cromossomos Artificiais de Levedura , Clonagem Molecular , Cosmídeos , Deleção de Genes , Ligação Genética , Humanos , Masculino , SíndromeRESUMO
The time course of changes in cerebral intravascular volume was evaluated during 24 h following a series of three 5-min carotid artery occlusions spaced at 1-h intervals and compared with the changes occurring after single 5- or 15-min occlusions. Quantitative estimates of cerebral red cell volume, plasma volume, and total blood volume were obtained from the distribution spaces of 51Cr-labeled erythrocytes and 125I-albumin infused prior to killing at varied recirculation intervals. Significant reductions in vascular volume occurred in all ischemic brain regions within 1 h following a single 5-min occlusion, which recovered to control values within 6 h. A similar time course was seen after repeated occlusions. The reductions in volume remained significant at 6 h after a single 15-min occlusion, but there was no difference from control by 24 h. Thus, the time course of total vascular volume correlates well with that of CBF changes previously described, and both blood flow and blood volume are at normal levels during the time of severe edema 24 h after repeated occlusions. Calculated cerebral hematocrit was 60-70% of that obtained from the femoral artery, but was identical in all brain regions and was constant throughout the postischemic recirculation period, with the exception of a transient reduction in both peripheral and cerebral hematocrit observed at 6-h recirculation following single 15-min occlusions. These results suggest that changes in CBF and blood volume reflect primarily the status of larger vessels and that values in the normal range may be observed even under conditions of severe edema and impaired perfusion at the capillary level.
Assuntos
Volume Sanguíneo , Edema Encefálico/fisiopatologia , Isquemia Encefálica/fisiopatologia , Encéfalo/fisiopatologia , Circulação Cerebrovascular , Animais , Feminino , GerbillinaeRESUMO
One of the challenges in human genome research is to identify the promoter sequences which play a key role in the regulation of gene expression. We report here a new promoter trapping system for use with mammalian cells comprised of the following three steps: 1) Cloning of DNA fragments into a promotertrapping vector, 2) integration of the trapping vector into a designated target in the mammalian genome using the Cre site-specific recombinase, and 3) screening of integrants for trapped promoter sequences by activation of the luciferase gene. To assess the efficiency of this system, lox trapping vectors containing sense tk promoter, antisense tk promoter, or a non-promoter sequence of the neo gene were employed. The resulting levels of luciferase activity of the site-specific integrants were measured directly. Luciferase activity of the integrants can be assayed under conventional culture conditions by simply replacing the culture medium with potassium phosphate buffer containing luciferin. Only those G418r colonies carrying the tk promoter in the normal orientation exhibited a 21-to 35-fold increase in luciferase activity over that of the other integrants. These results indicate that this system is an effective means of trapping promoter sequences from random mammalian genomic DNA fragments.
Assuntos
Técnicas Genéticas , Integrases/genética , Mamíferos/genética , Regiões Promotoras Genéticas , Recombinação Genética , Proteínas Virais , Animais , Linhagem Celular , Clonagem Molecular , Vetores Genéticos , Canamicina Quinase , Luciferases/genética , Luciferases/metabolismo , Camundongos , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Timidina Quinase/genética , TransfecçãoRESUMO
Five distinct novel transcripts (RES4-22, -23, -24, -25 and -26) that mapped to the 1-Mb interval between D4S180 and D4S183 on human chromosome 4p16.3 close to the Huntington's disease (HD) gene were isolated, and the structure and exon/intron organization of each gene were thoroughly analyzed. The transcripts of the RES4-22, -23 and -24 genes each have several isoforms by alternative splicing and these have also been defined. Two transcripts, RES4-24 and RES4-25, reside in the same genomic region with opposite polarities and they also clearly overlap. Among these transcripts, RES4-26 was found to encode a novel zinc finger protein. The transcript map based upon our current level of analysis combined with data from previous studies reveals the gene-rich nature and the intricate organization of the genes in the HD locus.
Assuntos
Cromossomos Humanos Par 4 , Doença de Huntington/genética , Proteínas do Tecido Nervoso/genética , Transcrição Gênica , Processamento Alternativo , Sequência de Aminoácidos , Northern Blotting , Mapeamento Cromossômico , Clonagem Molecular , DNA Complementar , Éxons/genética , Expressão Gênica , Humanos , Íntrons/genética , Dados de Sequência Molecular , Proteínas Nucleares , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
Six hundred and twenty-seven cDNA clones from human brain cDNA libraries were characterized and integrated into a transcript map of the 1-Mb region on human chromosome 4p16.3 containing the Huntington's disease (HD) gene. Six hundred and seventy-two cDNA clones were obtained by a direct screening of the cDNA libraries, probing with pools of single copy microclones generated from the HD region specific yeast artificial chromosome (YAC)-DNA. So far, 93% of the obtained clones (627 cDNA clones) have been mapped onto the 1-Mb HD gene region by hybridization with HD region-specific cosmid, P1 and YAC clones. DNA sequence and expression analyses revealed that several cDNA clones might encode novel genes, some of which are situated within or close to the IT15, IT11, and alpha-adducin (ADD1) gene region, suggesting the presence of the overlapping genes in this region. This collection of cDNA clones will greatly facilitate the construction of the complete map of the transcripts in the HD region.