RESUMO
Diffuse pulmonary arteriovenous malformations (AVMs) are associated with a poor prognosis and the therapeutic strategy remains controversial. We describe a pediatric patient with diffuse pulmonary AVMs associated with hereditary hemorrhagic telangiectasia (HHT), who presented with two cerebral AVMs in the parietal and occipital lobes as well. Of note, successful bilateral lung transplantation not only improved the hypoxemia but also resulted in size reduction of the cerebral AVMs. Although it is essential to consider involvements other than pulmonary AVMs, especially brain AVMs, to decide the indication, lung transplantation can be a viable therapeutic option for patients with diffuse pulmonary AVMs and HHT.
Assuntos
Malformações Arteriovenosas/complicações , Pneumopatias/complicações , Transplante de Pulmão , Adolescente , Malformações Arteriovenosas/terapia , Feminino , Humanos , Malformações Arteriovenosas Intracranianas/complicações , Ataque Isquêmico Transitório/complicações , Pneumopatias/terapia , Telangiectasia Hemorrágica Hereditária/complicações , Telangiectasia Hemorrágica Hereditária/terapia , Resultado do TratamentoRESUMO
In order to determine the molecular basis of cytoplasmic male sterility (CMS) in alloplasmic lines of eggplant, the genomic structures and transcription patterns of mitochondrial ATP synthase subunit (atp) and cytochrome oxidase subunit (cox) genes were studied for wild and cultivated eggplants. Alloplasmic eggplant lines with cytoplasms of wild Solanum species showing either anther indehiscent type of CMS or non-pollen production type of CMS were studied with the cultivated eggplant Solanum melongena, used as a control. Southern hybridization of the mitochondrial genes indicated the difference between the two types of CMS and showed complete identity within each type. The cytoplasmic patterns of all wild species differed from that of the cultivated eggplant. Thus, the cytoplasm of the six wild eggplants and the one cultivated eggplant was classified into three groups. Male sterile plants of both types of CMS showed novel transcription patterns of atp1, whereas a different transcription pattern of cox2 was observed only in the anther indehiscent type. Based on these differences, we determined the DNA sequences of about a 4 kbp segment in the atp1 region. Although the coding and 3' flanking regions were almost identical among the cytoplasms, the 5' flanking region was completely different and novel open reading frames (orfs) were found for each of the CMS types and the cultivated eggplant. The cytoplasm of Solanum kurzii inducing the anther indehiscent type CMS had orf312, and those of Solanum aethiopicum and Solanum grandifolium of non-pollen production type CMS had orf218. The correspondence between the transcription patterns of these orfs and phenotypic expression of male sterility strongly suggests that these orfs are causal genes for each type of CMS.
Assuntos
Genes Mitocondriais , Genes de Plantas , Infertilidade das Plantas/genética , Solanum/genética , Transcrição Gênica , Sequência de Bases , Polimorfismo de Fragmento de Restrição , Análise de Sequência de DNARESUMO
OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a progressive debilitating neurodegenerative disease with a life expectancy of 3-5 years from initial symptoms. We report a case of ALS who received autologous adipose-derived mesenchymal stem cells (ADSC) and was followed up for 7 years. CASE REPORT: A 46-year-old man noticed weakness of his legs, difficulties on going down the stairs and coughing during eating in 2009. After complete workout, a diagnosis of ALS was confirmed. His ALS Functional Rating Scale-R (ALSFS-R) was 43. Symptoms rapidly progressed and he coughed and choked during eating. Starting in 2013, the patient received a total of six intravenous infusions of autologous ADSC. Changes in electromyogram, nerve conduction, and ALSFS-R were assessed. RESULTS: Soon after the administration, he noticed that he did not cough during conversation or eating food. Although he had difficulty in walking down the stairs, he remained well without coughing, dysarthria, or dysphagia. His ALSFS-R increased up to 45. Fascicular potentials were not detected in any muscles examined including trapezius muscle and rectus femoris muscles. The patient was well for 7 years after ADSC therapy by the time of this report and more than 10 years from the time of onset. CONCLUSIONS: The present case suggests that autologous ADSC can be administered safely and may be potentially useful in patients with ALS. Further investigations are warranted in order for the results to be generalized to other ALS patients.
Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Esclerose Lateral Amiotrófica/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Sobreviventes , Transplante AutólogoRESUMO
Circular DNAs excised by immunoglobulin kappa chain gene rearrangements were cloned and characterized. 16 of 17 clones examined were double recombination products containing a V kappa-J kappa rearrangement (coding joint) as well as the reciprocal element (signal joint) of another V kappa-J kappa rearrangement. These products suggested multiple recombination, primary inversion, and secondary excision. In primary events, 5 of 16 translational reading frames were in-phase. Thus, V kappa gene rearrangement may not be inhibited by the presence of a productively rearranged allele. An unusually large trinucleotide (P) insertion forming a palindrome of 12 nucleotides was also observed in one of the coding joints.
Assuntos
Rearranjo Gênico do Linfócito B/genética , Região Variável de Imunoglobulina/genética , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Circular/genética , Retroalimentação , Região de Junção de Imunoglobulinas/genética , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Biossíntese de ProteínasRESUMO
We have identified circular DNAs containing the kappa light chain constant region (C kappa), as well as the excision products of V kappa-J kappa and V lambda-J lambda joining in adult mouse splenocytes. Analysis of C kappa-positive circular DNA clones revealed two recombination sites (intron recombining sequence [IRS]1 and -2) within the germline J kappa-C kappa intron region and the recombining sequence (RS) located downstream of the C kappa exon. While RS contains a conserved heptamer and nonamer separated by a 23-bp spacer on the 5' side, IRS1 sequence is an isolated heptamer without an obvious nonamer, and IRS2 contains a variant heptamer, CACAAAA. Since IRS1 and IRS2 recombined with both RS (23-bp spacer signal) and V kappa (12-bp spacer signal) with significant frequency, intron recombination sites seem to have dual recombination signals. These findings provide direct evidence that C kappa deletion preceding lambda gene rearrangement can occur by looping out and excision. Increased accessibility of inefficient recombinational loci within the intron may enable recombinase to accept wide signal sequence variation.
Assuntos
Deleção Cromossômica , DNA/genética , Cadeias kappa de Imunoglobulina/genética , Baço/ultraestrutura , Animais , Sequência de Bases , Mapeamento Cromossômico , DNA/análise , DNA/metabolismo , Feminino , Rearranjo Gênico/genética , Cadeias lambda de Imunoglobulina/genética , Íntrons , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Recombinação Genética , Baço/química , Baço/metabolismoRESUMO
We have characterized extrachromosomal circular DNAs from adult mouse spleen cells that were induced to switch to immunoglobulin A (IgA) with bacterial lipopolysaccharide (LPS) and transforming growth factor beta (TGF-beta), and identified breakpoints of S mu/S gamma 3, S mu/S gamma 2, S mu/S alpha, S gamma 3/S alpha, and S gamma 2/S alpha recombinants. The S mu recombination donor sites clustered in the 3' half of the S mu region, while the S alpha recombination acceptor sites clustered in the 5' half of the S alpha region. In addition, donor and acceptor sites of S gamma regions also clustered in the 3' and 5' parts, respectively. These site preferences are in sharp contrast to the dispersed distribution of S mu/S gamma 1 breakpoints within both S mu and S gamma 1 regions upon IgG1 switch induced by LPS and interleukin 4. Our results support the hypotheses that TGF-beta increases the frequency of switch recombination events to IgA and that the switch recombination to IgA often proceeds by successive recombination of S mu/S gamma and S gamma/S alpha.
Assuntos
Genes de Troca , Imunoglobulina G/genética , Região de Troca de Imunoglobulinas , Recombinação Genética , Fator de Crescimento Transformador beta/farmacologia , Animais , Sequência de Bases , Clonagem Molecular , DNA Circular/genética , Feminino , Biblioteca Gênica , Genes de Troca/efeitos dos fármacos , Região de Troca de Imunoglobulinas/efeitos dos fármacos , Interleucina-4/farmacologia , Lipopolissacarídeos , Camundongos , Camundongos Endogâmicos BALB C , Modelos Genéticos , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Plasmídeos , Recombinação Genética/efeitos dos fármacos , Mapeamento por Restrição , Baço/imunologiaRESUMO
Necl-5 is an immunoglobulin-like molecule that was originally identified as a poliovirus receptor. Although Necl-5 expression is often up-regulated in cancer cells, its pathophysiological significance in the development of cancer remains unclear. We investigated the roles of Necl-5 in the development of colitis-associated neoplasia. Necl-5-deficient mice were generated and treated with dimethylhydrazine (DMH) and/or dextran sodium sulphate (DSS) to induce colitis and its associated neoplasias. Colon tissues were examined for histology, Ki-67 expression by immunohistochemistry and K-ras gene mutation. Colon tumours occurred significantly less frequently in heterozygous (Necl-5(+/-)) or homozygous Necl-5-deficient (Necl-5(-/-)) mice than in wild-type (WT) mice with DMH/DSS treatment. Total ulcer index and inflammatory cell infiltration were significantly lower in Necl-5(-/-) mice than in WT mice with DSS alone or DMH/DSS treatment. Colon tumours in both WT and Necl-5(-/-) mice showed high cell proliferation ability but lacked K-ras mutation. The total Ki-67 labelling index in non-neoplastic colon epithelium was significantly higher in WT (45.9 +/- 0.94) than in Necl-5(+/-) (34.3 +/- 1.40) or Necl-5(-/-) (27.7 +/- 1.15) mice with DMH/DSS treatment (p < 0.001). Necl-5 plays a role in the development of colitis-associated cancer by up-regulating colonic mucosal cell proliferation.
Assuntos
Antígenos de Neoplasias/fisiologia , Moléculas de Adesão Celular/fisiologia , Neoplasias Colorretais/fisiopatologia , Proteínas de Neoplasias/fisiologia , Animais , Peso ao Nascer , Moléculas de Adesão Celular/deficiência , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/complicações , Colite Ulcerativa/patologia , Colo/patologia , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/patologia , Sulfato de Dextrana , Dimetilidrazinas , Modelos Animais de Doenças , Genes ras/genética , Crescimento , Mucosa Intestinal/patologia , Antígeno Ki-67/metabolismo , Camundongos , Camundongos Knockout , Mutação , Proteínas de Neoplasias/deficiência , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
Recently, gastric fundic atrophy is reported to be an independent risk factor for esophageal squamous-cell carcinoma (ESCC). The aim of this study is to investigate the acid secretory level in ESCC in a case-control study. From April 2004 to March 2008, 100 consecutive subjects with early ESCC and 100 age- and sex-matched asymptomatic controls were prospectively enrolled. Gastrin-stimulated acid output was assessed by endoscopic gastrin test. Conditional regression analyses were used to adjust for other potential confounders. Multivariate analyses revealed a strong association between profound hypochlorhydria and ESCC with odds ratio (95% confidence interval): 6.0 (1.9-18.4). The association remained significant after adjusting for the effect of gastric atrophy as a covariate. The association became stronger as the ESCC developed more distal site of the esophagus. This study indicates that profound hypochlorhydria is a strong independent risk factor for ESCC even after adjusting for the influence of gastric atrophy.
Assuntos
Carcinoma de Células Escamosas/etiologia , Neoplasias Esofágicas/etiologia , Ácido Gástrico/metabolismo , Gastrite Atrófica/complicações , Idoso , Biópsia , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Endoscopia Gastrointestinal , Neoplasias Esofágicas/patologia , Feminino , Infecções por Helicobacter/epidemiologia , Helicobacter pylori , Humanos , Modelos Logísticos , Masculino , Pepsinogênio A/sangue , Estudos Prospectivos , Análise de RegressãoRESUMO
The regenerating gene (Reg) was originally isolated from regenerating rat pancreatic islets and revealed recently to constitute a multi-gene family in humans. REG Ialpha protein is known to be overexpressed not only in various human inflammatory diseases but also in various experimental models of inflammation in animal tissues. However, its involvement in pathophysiology of the minor salivary gland (MSG) is not clear. We investigated REG Ialpha expression in the MSG of patients with primary Sjögren's syndrome (SS) and assessed its role in ductal epithelial cell proliferation in such tissues. Lip biopsy specimens were obtained from 40 patients with primary SS and examined using immunohistochemistry for REG Ialpha protein, Ki67 and single-strand DNA (ssDNA). The relationships among clinicopathological factors and expression of REG Ialpha protein, Ki67 and ssDNA in the MSG were then analysed. REG Ialpha protein was expressed rarely in ductal epithelial cells of the normal MSG but was apparently overexpressed in those of patients with SS. The labelling indices for both Ki67 and ssDNA in the ductal cells of the MSGs were significantly higher in SS patients than in controls. Moreover, these labelling indices were significantly higher in REG Ialpha-positive than in negative SS patients. REG Ialpha protein may play a role in the regeneration of ductal epithelial cells in the MSGs of patients with SS.
Assuntos
Células Epiteliais/fisiologia , Litostatina/análise , Regeneração/fisiologia , Ductos Salivares/fisiologia , Glândulas Salivares Menores , Síndrome de Sjogren/patologia , Adolescente , Adulto , Idoso , Biomarcadores/análise , Divisão Celular/fisiologia , DNA de Cadeia Simples/análise , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Litostatina/metabolismo , Masculino , Pessoa de Meia-Idade , Ductos Salivares/metabolismo , Ductos Salivares/patologia , Síndrome de Sjogren/metabolismo , Adulto JovemRESUMO
Microdeletions of chromosome 22q11 are the most common genetic defects associated with cardiac and craniofacial anomalies in humans. A screen for mouse genes dependent on dHAND, a transcription factor implicated in neural crest development, identified Ufd1, which maps to human 22q11 and encodes a protein involved in degradation of ubiquitinated proteins. Mouse Ufd1 was specifically expressed in most tissues affected in patients with 22q11 deletion syndrome. The human UFD1L gene was deleted in all 182 patients studied with 22q11 deletion, and a smaller deletion of approximately 20 kilobases that removed exons 1 to 3 of UFD1L was found in one individual with features typical of 22q11 deletion syndrome. These data suggest that UFD1L haploinsufficiency contributes to the congenital heart and craniofacial defects seen in 22q11 deletion.
Assuntos
Cromossomos Humanos Par 22/genética , Anormalidades Craniofaciais/genética , Deleção de Genes , Cardiopatias Congênitas/genética , Proteínas/genética , Proteínas Adaptadoras de Transporte Vesicular , Animais , Aorta Torácica/anormalidades , Aorta Torácica/embriologia , Aorta Torácica/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Crista Neural/citologia , Crista Neural/embriologia , Fenótipo , Proteínas/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Ubiquitinas/metabolismo , Proteínas de Peixe-ZebraRESUMO
Radiotherapy is an effective treatment for some esophageal cancers, but the molecular mechanisms of radiosensitivity remain unknown. RUNX3, a novel tumor suppressor of gastric cancer, functions in transforming growth factor (TGF)-beta-dependent apoptosis. We obtained paired samples from 62 patients with advanced esophageal cancers diagnosed initially as T3 or T4 with image diagnosis; one sample was obtained from a biopsy before presurgical radiotherapy, and the other was resected in surgical specimens after radiotherapy. RUNX3 was repressed in 67.7% cases of the pretreatment biopsy samples and 96.7% cases of the irradiated, resected samples. The nuclear expression of RUNX3 was associated with radiosensitivity and a better prognosis than cytoplasmic or no RUNX3 expression (P<0.003); cytoplasmic RUNX3 expression was strictly associated with radioresistance. RUNX3 was downregulated and its promoter was hypermethylated in all radioresistant esophageal cancer cell lines examined. Stable transfection of esophageal cancer cells with RUNX3 slightly inhibited cell proliferation in vitro, enhanced the antiproliferative and apoptotic effects of TGF-beta and increased radiosensitivity in conjunction with Bim induction. In contrast, transfection of RUNX3-expressing cells with a RUNX3 antisense construct or a Bim-specific small interfering RNA induced radioresistance. Treatment with 5-aza-2'-deoxycytidine restored RUNX3 expression, increased radiosensitivity and induced Bim in both control and radioresistant cells. These results suggest that RUNX3 silencing promotes radioresistance in esophageal cancers. Examination of RUNX3 expression in pretreatment specimens may predict radiosensitivity, and induction of RUNX3 expression may increase tumor radiosensitivity.
Assuntos
Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/radioterapia , Subunidade alfa 3 de Fator de Ligação ao Core/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/radioterapia , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , Idoso , Biópsia , Carcinoma de Células Escamosas/diagnóstico , Diferenciação Celular , Núcleo Celular/metabolismo , Neoplasias Esofágicas/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Tolerância a RadiaçãoRESUMO
Although stromal cell-derived factor (SDF)-1 alpha and its receptor CXCR4 are experimentally suggested to be involved in tumorigenicity, the clinicopathological significance of their expression in human disease is not fully understood. We examined SDF-1 alpha and CXCR4 expression in colorectal cancers (CRCs) and their related lymph nodes (LNs), and investigated its relationship to clinicopathological features. Specimens of 60 primary CRCs and 27 related LNs were examined immunohistochemically for not only positivity but also immunostaining patterns for SDF-1 alpha and CXCR4. The relationships between clinicopathological features and SDF-1 alpha or CXCR4 expression were then analysed. Stromal cell-derived factor-1 alpha and CXCR4 expression were significantly associated with LN metastasis, tumour stage, and survival of CRC patients. Twenty-nine of 47 CXCR4-positive CRCs (61.7%) showed clear CXCR4 immunoreactivity in the nucleus and a weak signal in the cytoplasm (nuclear type), whereas others showed no nuclear immunoreactivity but a diffuse signal in the cytoplasm and at the plasma membrane (cytomembrane type). Colorectal cancer patients with nuclear CXCR4 expression showed significantly more frequent LN metastasis than did those with cytomembrane expression. Colorectal cancer patients with nuclear CXCR4 expression in the primary lesion frequently had cytomembrane CXCR4-positive tumours in their LNs. In conclusion, expression of SDF-1 alpha and nuclear CXCR4 predicts LN metastasis in CRCs.
Assuntos
Biomarcadores Tumorais/análise , Quimiocina CXCL12/análise , Neoplasias Colorretais/química , Neoplasias Colorretais/patologia , Linfonodos/química , Linfonodos/patologia , Receptores CXCR4/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Western Blotting , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Análise de SobrevidaRESUMO
BACKGROUND: Regenerating gene type IV (RegIV) is a candidate marker for cancer and inflammatory bowel disease. In this study, its potential as a novel marker for the detection of gastric cancer peritoneal micrometastases was examined. PATIENTS AND METHODS: RegIV mRNA levels in the peritoneal washes of 95 gastric cancer patients and 22 with benign disease were quantified by real-time RT-PCR. To examine whether expression of RegIV enhance tumorigenicity or not, thirty two mice were injected intraperitoneally or subcutaneously with RegIV transfectants of TMK-1 cells, parental TMK-1 cells, or neomycin control transfectants. RESULTS: RegIV expression was markedly higher in patients with peritoneal metastases compared to those without. The level of RegIV mRNA in gastric cancer patients was related to the extent of wall penetration. A cut-off value for RegIV-positive expression was based on an analysis of negative control patients with benign disease, and gastric cancer patients above the cut-off value constituted the micrometastasis (MM+) group. Based on this criteria, 3 out of 43 T1 or T2 cases were MM+ (93% specificity). Among 15 patients with peritoneal dissemination (7 out of 15 cases were positive by cytology), 14 cases were positive for RegIV expression (93% sensitivity), while analysis of carcinoembryonic antigen (CEA) mRNA failed to detect micrometastases in 4 cases (73% sensitivity). Combined analysis of CEA and RegIV improved the accuracy of diagnosis to 100%. The prognosis of RegIV-positive cases was significantly worse than that of RegIV-negative cases. Multivariate analysis using the Cox proportional hazards model suggested that RegIV may be an independent prognostic factor. Stable expression of RegIV significantly enhanced peritoneal metastasis in an animal model of gastric cancer. CONCLUSION: These findings suggest that RegIV mRNA expression has the potential to serve as a novel marker for detecting peritoneal dissemination in gastric cancer.
Assuntos
Lectinas Tipo C/biossíntese , Actinas/biossíntese , Actinas/genética , Animais , Biomarcadores Tumorais , Antígeno Carcinoembrionário/biossíntese , Antígeno Carcinoembrionário/genética , Linhagem Celular Tumoral , Mucosa Gástrica/metabolismo , Mucosa Gástrica/fisiologia , Células HL-60 , Humanos , Lectinas Tipo C/genética , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Nus , Invasividade Neoplásica , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Proteínas Associadas a Pancreatite , Neoplasias Peritoneais/genética , Neoplasias Peritoneais/metabolismo , Neoplasias Peritoneais/secundário , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , TransfecçãoRESUMO
OBJECTIVE: Establishment of tetraploid ES cells. MATERIALS AND METHODS: Mouse H-1 (ES) cells were polyploidized by demecolcine and released from the drug. RESULTS: A tetraploid cell line (4nH1 cells) was established from mouse H-1 (ES) cells (2nH1 cells) highly polyploidized by treatment with demecolcine. Cell cycle parameters of 4nH1 cells were almost the same as those of 2nH1 cells, suggesting that the rate of DNA synthesis was about twice that of the diploid cells. Mode of chromosome number of 4nH1 cells was 76, about twice that of 2nH1 cells. Cell volume of 4nH1 cells was about twice of that of diploid cells, indicating that 4nH1 cells contained about twice as much total intracellular material as 2nH1 cells. Morphology of the 4nH1 cells was flagstone-like, thus differing from that of the spindle-shaped 2nH1 cells, suggesting that the transformation had occurred during the diploid-tetraploid transition. 4nH1 cells exhibited alkaline phosphatase activity and formed teratocarcinomas, implying that they would be pluripotent. CONCLUSION: A pluripotent tetraploid cell line (4nH1 cells) was established.
Assuntos
Técnicas de Cultura de Células/métodos , Células-Tronco Embrionárias/citologia , Células-Tronco Pluripotentes/citologia , Poliploidia , Animais , Antineoplásicos Fitogênicos , Linhagem Celular , Demecolcina , Camundongos , Camundongos Endogâmicos C3H , Transplante de Células-Tronco , TeratocarcinomaRESUMO
Reciprocal interactions between vascular endothelial cells and vascular mesenchymal cells are essential for angiogenesis. Here we show that the basic helix-loop-helix transcription factor, dHAND/Hand2, is expressed in the developing vascular mesenchyme and its derivative, vascular smooth muscle cells (VSMCs). Targeted deletion of the dHAND gene in mice revealed severe defects of embryonic and yolk sac vascular development by embryonic day 9.5. Vascular endothelial cells expressed most markers of differentiation. Vascular mesenchymal cells migrated appropriately but failed to make contact with vascular endothelial cells and did not differentiate into VSMCs. In a screen for genes whose expression was dependent upon dHAND (using subtractive hybridization comparing wild-type and dHAND-null hearts), the VEGF(165) receptor, neuropilin-1, was found to be downregulated in dHAND mutants. These results suggest that dHAND is required for vascular development and regulates angiogenesis, possibly through a VEGF signaling pathway.
Assuntos
Vasos Sanguíneos/embriologia , Vasos Sanguíneos/fisiologia , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica no Desenvolvimento , Músculo Liso Vascular/fisiologia , Fatores de Transcrição/genética , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Desenvolvimento Embrionário e Fetal , Mesoderma/fisiologia , Camundongos , Músculo Liso Vascular/embriologia , Proteínas de Peixe-ZebraRESUMO
Multiple attempts have been made to replace biliary defects with a variety of materials. Recently, successful biliary reconstruction using the Gore-Tex vascular graft has been reported experimentally and clinically. We designed a new artificial bile duct consisting of collagen sponge and polypropylene mesh. We presently evaluated the feasibility of using this prosthesis as a scaffold for bile duct tissue regeneration in a canine model. Our prosthesis, a sponge made from porcine dermal collagen, is reinforced with a polypropylene mesh cylinder. We used the prosthesis to reconstruct the middle portion of the common bile duct in seven beagle dogs to evaluate its efficacy. While one dog died of biliary stricture 8 months after operation, six survived without problems to scheduled time points for tissue evaluation at 1 to 12 months. All prostheses had become completely incorporated into the host. A confluent epithelial lining was observed within 3 months. In cholangiograms the prosthesis displayed long-term patency in the six dogs and provided satisfactory bile drainage for up to 12 months. Our graft thus shows promise for repair of biliary defects and should lead to development of a new treatment for biliary reconstruction.
Assuntos
Ducto Colédoco/cirurgia , Desenho de Prótese , Implantação de Prótese , Engenharia Tecidual , Animais , Ductos Biliares/citologia , Colágeno , Ducto Colédoco/citologia , Cães , Células Epiteliais/citologia , PolipropilenosRESUMO
OBJECTIVES: We evaluated the value of coronary flow reserve (CFR), as determined by transthoracic Doppler echocardiography (TTDE), for physiologic assessment of coronary artery stenosis severity, and we compared TTDE measurements with those obtained by exercise thallium-201 (Tl-201) single-photon emission computed tomography (SPECT). BACKGROUND: Coronary flow reserve measurements by TTDE have been reported to be useful for assessing angiographic left anterior descending coronary artery (LAD) stenosis. However, discrepancies exist between angiographic and physiologic estimates of coronary lesion severity. METHODS: We studied 36 patients suspected of having coronary artery disease. The flow velocity in the distal LAD was measured by TTDE both at rest and during intravenous infusion of adenosine. Coronary flow reserve was calculated as the ratio of hyperemic to basal peak (peak CFR) and mean (mean CFR) diastolic flow velocities. The CFR measurements by TTDE were compared with the results of Tl-201-SPECT. RESULTS: Complete TTDE data were acquired for 33 of 36 study patients. Of these 33 patients, Tl-201-SPECT confirmed reversible perfusion defects in the LAD territories in 12 patients (group A). Twenty-one patients had normal perfusion in the LAD territories (group B). Peak CFR and mean CFR (mean value +/- SD) were 1.5 +/- 0.6 and 1.5 +/- 0.7 in group A and 2.8 +/- 0.8 and 2.7 +/- 0.7 in group B, respectively. Both peak and mean CFR < or = 2.0 predicted reversible perfusion defects, with a sensitivity and specificity of 92% and 90%, respectively. CONCLUSIONS: Noninvasive measurement of CFR by TTDE provides data equivalent to those obtained by Tl-201-SPECT for physiologic estimation of the severity of LAD stenosis.
Assuntos
Circulação Coronária/fisiologia , Doença das Coronárias/fisiopatologia , Ecocardiografia Doppler , Tomografia Computadorizada de Emissão de Fóton Único , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Meios de Contraste , Angiografia Coronária , Doença das Coronárias/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissacarídeos , Sensibilidade e Especificidade , Radioisótopos de TálioRESUMO
A total of 36 clones were randomly selected from a recombinant DNA library of small polydisperse circular DNA (spcDNA) molecules from HeLa cells and were shown to contain repetitive sequences of different reiteration frequencies that ranged from several hundred to several hundred thousand per genome. Sequencing of representative clones revealed tandem repeats of alphoid (alpha) satellite DNA, clustered repeats of the Alu family, KpnI family sequences, tandem repeats of an alpha satellite DNA specific to the X chromosome (alpha X), and A + T-rich segments carrying short stretches of poly(A) or poly(T). DNA rearrangement was frequently found in the repetitive sequences enriched in these spcDNA clones. Short regions of homology that were patchy and inverted were often found, especially at the novel joint where spcDNA sequences are circularized. The presence of these inverted repeats suggests that HeLa spcDNAs are formed by a mechanism that involves looping out of the spcDNA region and joining of the flanking DNA by illegitimate recombination.
Assuntos
DNA Circular , Sequências Repetitivas de Ácido Nucleico , Sequência de Bases , Células HeLa , Humanos , Dados de Sequência MolecularRESUMO
Electron microscopy was applied to thin crystals of yeast tRNAPhe. The crystals embedded in glucose yield Bragg reflections with a spacing smaller than 4 A. The measurement of radiation damage rate demonstrates that they are 4 to 14 times less susceptible to electron exposures than protein crystals embedded in glucose.
Assuntos
Aminoacil-RNA de Transferência/efeitos da radiação , Bacteriorodopsinas/efeitos da radiação , Catalase/efeitos da radiação , Cristalização , Elétrons , Microscopia Eletrônica , Saccharomyces cerevisiae/análiseRESUMO
Small polydisperse circular (spc) DNA was isolated from mouse thymocytes, fragmented by HindIII digestion and cloned into the vector. Sixty DNA clones were randomly selected from the 10,400 phage library. The average size of insert was one-fifth of the original circular molecule. Twenty spc-DNA clones were homologous to DNA probes derived from T-cell antigen receptor (TCR) alpha-chain loci. We have characterized nine clones by DNA sequencing; they contain new germline sequences of the TCR alpha-chain variable (V alpha) and joining (J alpha) gene segments and the products out of the recombination of a V alpha with a J alpha gene segment. An additional four spc-DNA clones carried a new rearranging gene of the TCR delta-chain that is located between V alpha and J alpha genes. At least nine of 60 DNA clones carried the recombination junction of a heptamer-heptamer head-to-head structure expected from an excised product of V-J joining. This shows that most extrachromosomal circular DNAs in the thymus are formed by a sequence-dependent recombination mechanism. We suggest that a functional T-cell receptor V alpha gene can be constructed by somatic random rearrangements through successive looping-out, excision and deletion.