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1.
Dis Esophagus ; 32(9)2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31037293

RESUMO

Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291.


Assuntos
Esôfago de Barrett/diagnóstico por imagem , Padrões de Prática Médica/estatística & dados numéricos , Tomografia de Coerência Óptica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Esôfago de Barrett/patologia , Esôfago de Barrett/terapia , Biópsia , Tomada de Decisão Clínica , Sistemas Computacionais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Tomografia de Coerência Óptica/estatística & dados numéricos , Estados Unidos
2.
Endoscopy ; 44(2): 161-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22109650

RESUMO

BACKGROUND AND STUDY AIMS: Open or laparoscopic gastrojejunostomy is an established treatment for malignant duodenal obstruction but may be associated with significant morbidity and mortality. The purpose of this study was to develop a model for an entirely endoscopic gastrojejunostomy to treat duodenal obstruction, and to compare this with the laparoscopic technique. METHODS: During the first part of the study the endoscopic technique was developed and tested in porcine nonsurvival and survival experiments (n=12). During the second part of the study (n=10), endoscopic gastrojejunostomy for duodenal occlusion was compared with laparoscopic gastrojejunostomy in a survival randomized controlled trial (RCT). For both groups duodenal occlusion was achieved by the laparoscopic approach. RESULTS: In the RCT, the median times for laparoscopic vs. endoscopic gastrojejunostomy were 70 minutes (interquartile range [IQR] 65-75) vs. 210 minutes (IQR 197-220; P=0.01). There was a trend toward increased anastomotic diameter at necropsy in the laparoscopic group (2 cm, IQR 2-3) compared to the endoscopic group (1.8 cm, IQR 1.6-1.8; P=0.06). One animal in the endoscopic group died secondarily to bowel ischemia from volvulus of the jejunal loop. One animal in the laparoscopic group was prematurely sacrificed due to extensive pulmonary congestion and edema. All anastomoses were intact and patent. CONCLUSIONS: Purely endoscopic gastrojejunostomy using the developed technique and devices is feasible and can result in adequate relief of duodenal obstruction. Endoscopic anastomoses tend to be smaller than laparoscopic anastomoses, with the procedures being more time-consuming and associated with higher complication rates.


Assuntos
Obstrução Duodenal/cirurgia , Endoscopia Gastrointestinal/métodos , Derivação Gástrica/métodos , Laparoscopia/métodos , Animais , Modelos Animais de Doenças , Endoscopia Gastrointestinal/instrumentação , Endoscopia Gastrointestinal/mortalidade , Feminino , Derivação Gástrica/instrumentação , Derivação Gástrica/mortalidade , Laparoscopia/instrumentação , Laparoscopia/mortalidade , Distribuição Aleatória , Sus scrofa , Resultado do Tratamento
3.
Endoscopy ; 42(10): 790-9, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20886398

RESUMO

BACKGROUND AND STUDY AIMS: The impact of the diagnosis and treatment of dysplastic Barrett's esophagus on quality of life (QoL) is poorly understood. This study assessed the influence of dysplastic Barrett's esophagus on QoL and evaluated whether endoscopic treatment of dysplastic Barrett's esophagus with radiofrequency ablation (RFA) improves QoL. PATIENTS AND METHODS: We analyzed changes in QoL in the AIM Dysplasia Trial, a multicenter study of patients with dysplastic Barrett's esophagus who were randomly allocated to RFA therapy or a sham intervention. We developed a 10-item questionnaire to assess the influence of dysplastic Barrett's esophagus on QoL. The questionnaire was completed by patients at baseline and 12 months. RESULTS: 127 patients were randomized to RFA (n = 84) or sham (n = 43). At baseline, most patients reported worry about esophageal cancer (71 % RFA, 85 % sham) and esophagectomy (61 % RFA, 68 % sham). Patients also reported depression, impaired QoL, worry, stress, and dissatisfaction with the condition of their esophagus. Of those randomized, 117 patients completed the study to the 12-month end point. Compared with the sham group, patients treated with RFA had significantly less worry about esophageal cancer ( P=0.003) and esophagectomy ( P =0.009). They also had significantly reduced depression ( P=0.02), general worry about the condition of their esophagus ( P≤0.001), impact on daily QoL ( P=0.009), stress ( P=0.03), dissatisfaction with the condition of their esophagus ( P≤0.001), and impact on work and family life ( P=0.02). CONCLUSIONS: Inclusion in the treatment group of this randomized, sham-controlled trial of RFA was associated with improvement in disease-specific health-related quality of life. This improvement appears secondary to a perceived decrease in the risk of cancer.


Assuntos
Esôfago de Barrett/psicologia , Esôfago de Barrett/cirurgia , Ablação por Cateter , Qualidade de Vida/psicologia , Idoso , Ansiedade/etiologia , Distribuição de Qui-Quadrado , Neoplasias Esofágicas/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Lesões Pré-Cancerosas/prevenção & controle , Estatísticas não Paramétricas , Inquéritos e Questionários
4.
Endoscopy ; 42(4): 311-7, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20200808

RESUMO

BACKGROUND AND STUDY AIMS: In natural orifice transluminal endoscopic surgery (NOTES) procedures it is essential to be able to perform secure closure of the access perforation. The aim of this study was to compare endoscopically sutured closure of a gastric access gastrotomy using the tissue apposition system (TAS), with closure via laparotomy in a randomized multicenter study. METHODS: A total of 32 pigs (18 - 42 kg) were used in this study. The gastric NOTES access was created using a needle knife and a 20-mm balloon. Following transgastric pelvic peritoneoscopy, the endoscope was withdrawn into the stomach. The animals were then randomized to endoscopic closure or laparotomy with surgical closure. Procedure time, recovery time, and weight gain were measured. At necropsy, adhesions, abscesses or peritonitis were recorded. RESULTS: Of the 32 pigs, 29 survived 14 days without complications. All endoscopic and all open surgical closures were secure at postmortem. On average two suture pairs were used for endoscopic closure. Surgical closure was quicker (12.5 vs. 20.1 minutes). Recovery time and postoperative weight gain were similar for both groups. Two pigs in the endoscopic group died: one of gastric dilatation, without leakage from the gastrotomy; another was euthanized due to rectal prolapse. In the laparotomy group one pig was euthanized after 7 days due to abdominal wound dehiscence. At necropsy there were significantly more intra-abdominal adhesions in the laparotomized group. CONCLUSION: This randomized controlled study of endoscopic and surgical closure of a gastrotomy made for transperitoneal access for NOTES procedures suggests that both techniques are comparable in technical closure rates, postoperative recovery, and prevention of peritonitis. There were fewer adhesions in the endoscopic group.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Gastroscopia , Estômago/cirurgia , Técnicas de Sutura , Animais , Modelos Animais , Suínos
5.
Endoscopy ; 41(12): 1056-61, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19899033

RESUMO

BACKGROUND AND STUDY AIM: Secure and reliable endoscopic closure is of paramount importance before clinical introduction of transgastric natural orifice transluminal endoscopic surgery (NOTES). Gastrotomy closure in humans using standard endoclips has been reported. The aim of this study was to assess the safety of standard endoclip closure and to compare it to a new over-the-scope clip (OTSC) specifically designed for gastrotomy closure. MATERIAL AND METHODS: Gastric wall puncture and balloon dilation followed by peritoneoscopy was carried out in 20 female swine. After randomization, closure of the gastric incision was performed using a tissue approximation grasper and either endoclips or OTSCs. RESULTS: Mean (+/- SD) time for gastrotomy closure using endoclips was 31.5 +/- 24.2 minutes (range 8 - 88 minutes) compared with 8.5 +/- 9.1 minutes (range 2 - 31 minutes) using OTSC (P = 0.002). No intraoperative complications occurred. Laparoscopic leak tests with insufflation and saline immersion demonstrated three minor leaks and one major leak in the endoclip closures. No leaks were observed in the OTSC group. At necropsy, complete sealing of the gastrotomy sites was found in all OTSC closures. Small, localized perigastric abscesses were observed in two animals in the OTSC group and in three animals in the endoclip group. One animal in the endoclip group was sacrificed prematurely due to signs of sepsis and was found to have gross peritonitis secondary to a leak. At necropsy, evidence of peritonitis was identified in two other animals in the endoclip group. CONCLUSION: NOTES gastrotomy closure using standard endoclips, even with a tissue approximation grasper, is associated with an increased risk of leakage and intra-abdominal infection compared with OTSC. The significance of perigastric abscesses, which were seen in both groups, warrants further investigation.


Assuntos
Gastroscópios , Gastrostomia , Estômago/cirurgia , Instrumentos Cirúrgicos , Animais , Feminino , Gastroscopia/métodos , Estresse Mecânico , Suínos
7.
Aliment Pharmacol Ther ; 29(8): 817-23, 2009 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-19154568

RESUMO

BACKGROUND: There is little evidence to guide choice between meperidine (pethidine) and fentanyl for sedation for gastrointestinal endoscopy. AIM: To compare meperidine with fentanyl in terms of procedure time and analgesia. METHODS: Single centre randomized controlled trial. Patients received narcotic doses and midazolam at the discretion of the attending endoscopist who was unaware of narcotic assignment. Endoscopy and recovery times were then recorded. The main outcome was total procedure time, defined as endoscopy time plus recovery time. Patient discomfort was assessed prior to discharge via visual analogue scale (VAS). RESULTS: In total, 55 patients were randomized to meperidine [44 colonoscopy and 11 esophagogastroduodenoscopy (EGD)] and 56 to fentanyl (45 colonoscopy and 11 EGD). Total procedure time was shorter for those receiving fentanyl (mean = 87.7 min) than for those receiving meperidine (mean = 102.9 min) (P = 0.05). The difference between the groups was explained by a shorter mean recovery time in the fentanyl group (63.0 min) than in the meperidine group (76.2 min) (P = 0.07). Based on post procedure pain scores, examinations with meperidine (mean = 1.99) were less painful when compared with those receiving fentanyl (mean = 2.86, P = 0.03). CONCLUSIONS: Fentanyl shortened total procedure time by reducing recovery time. A simple change in narcotic choice could increase endoscopy unit efficiency.


Assuntos
Analgésicos Opioides/administração & dosagem , Sedação Consciente/métodos , Endoscopia Gastrointestinal/métodos , Fentanila/administração & dosagem , Meperidina/administração & dosagem , Adulto , Idoso , Período de Recuperação da Anestesia , Anestésicos Intravenosos/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor
8.
Surg Endosc ; 21(3): 439-44, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17180259

RESUMO

BACKGROUND: The purpose of the present study was to assess the long-term safety and durability of effect for endoscopic full-thickness plication for the treatment of symptomatic gastroesophageal reflux disease (GERD). The Plicator (NDO Surgical, Inc., Mansfield, MA) used delivers a transmural suture through the gastric cardia to restructure the antireflux barrier. Published reports have shown the Plicator procedure to be effective in reducing GERD symptoms and medication use at 1 year post-plication. METHODS: Twenty-nine patients with chronic heartburn requiring maintenance daily anti-secretory therapy were treated at five sites. Patients received a single full-thickness plication in the gastric cardia 1cm below the gastroesophageal junction (GE) junction. Re-treatments were not permitted. Patients were evaluated at baseline for GERD symptoms and medication use. Intermediate (12 month) and long-term subject follow-up (median follow-up: 36.4 months; range, 31.2-43.9 months) were completed to evaluate procedure safety and durability of effect. RESULTS: Twenty-nine patients completed the 12-month and 36-month follow-up. All procedure-related adverse events occurred acutely, and no new events were observed during extended follow-up. At 36-months post-procedure, 57% (16/28) of baseline proton pump inhibitor (PPI)-dependent patients remained off daily PPI therapy. Treatment effect remained stable from 12- to 36-months, with 21/29 patients off daily PPI at 12 months compared to 17/29 patients at 36-months. Median GERD- Health Related Quality of Life (HRQL) scores remained significantly improved at 36 months versus baseline off-meds scores (8 versus 19, p < 0.001). In addition, the proportion of patients achieving > or = 50% improvement in GERD-HRQL score was consistent from 12 months (59%) to 36 months (55%). CONCLUSIONS: Endoscopic full-thickness plication can reduce GERD symptoms and medication use for at least 3-years post-procedure. Treatment effect is stable from 1 to 3 years, and there are no long-term procedural adverse effects.


Assuntos
Endoscopia Gastrointestinal/métodos , Fundoplicatura/métodos , Refluxo Gastroesofágico/cirurgia , Dor Abdominal/etiologia , Adulto , Idoso , Antiácidos/uso terapêutico , Dor no Peito/etiologia , Transtornos de Deglutição/etiologia , Dispneia/etiologia , Endoscopia Gastrointestinal/efeitos adversos , Feminino , Seguimentos , Fundoplicatura/efeitos adversos , Mucosa Gástrica/lesões , Refluxo Gastroesofágico/tratamento farmacológico , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Faringite/etiologia , Inibidores da Bomba de Prótons , Qualidade de Vida , Resultado do Tratamento
9.
Aliment Pharmacol Ther ; 22(2): 123-8, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16011670

RESUMO

BACKGROUND: Prior studies suggest that histamines may modulate the development of colorectal neoplasia. AIM: To assess whether histamine receptor antagonist use was associated with adenoma formation. METHODS: Patients (n = 2366) were drawn from three adenoma chemoprevention trials. All underwent baseline colonoscopy with removal of adenoma(s) and were deemed free of remaining lesions; they were followed with surveillance colonoscopy. Medication use was assessed by questionnaire. Adjusted risk ratios for adenoma formation related to histamine receptor antagonist use (histamine H1 and H2 receptor, H1RA and H2RA) were determined using log linear models. RESULTS: In pooled analyses, H1RA exposure was not associated with subsequent adenoma risk (RR = 1.10; 95% CI 0.97-1.25) or multiple adenoma formation (RR = 0.85; 95% CI 0.67-1.07). H2RA use also was not associated with adenoma (RR = 0.90; 95% CI 0.77-1.06), or multiple adenoma (RR = 0.77; 95% CI 0.57-1.04) in the pooled analyses, but H2RA users in the first trial had a decreased risk of adenoma (RR = 0.70; 95% CI 0.48-1.03) and multiple adenoma (RR = 0.31; 95% CI 0.12-0.79). CONCLUSION: H2RA use was associated with reduced risk for adenoma in one trial, but not in the pooled analyses. Further study would be warranted before undertaking randomized trials of H2RAs for adenoma chemoprevention.


Assuntos
Adenoma/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Antagonistas dos Receptores Histamínicos H1/uso terapêutico , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco , Resultado do Tratamento
10.
J Clin Anesth ; 13(5): 387-91, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11498323

RESUMO

The EXIT (ex utero intrapartum treatment) procedure is used to maintain fetal-placental circulation during partial delivery of a fetus with a potentially life-threatening upper airway obstruction. We performed the EXIT procedure on a fetus with a large intra-oral cyst. Sevoflurane was used as the anesthetic because of its rapid titratability. Sevoflurane provided excellent maternal and fetal anesthesia. Modifications to previously described monitoring techniques for the EXIT procedure were also used.


Assuntos
Obstrução das Vias Respiratórias/cirurgia , Anestesia Obstétrica , Cistos/cirurgia , Doenças da Boca/cirurgia , Adulto , Obstrução das Vias Respiratórias/congênito , Obstrução das Vias Respiratórias/etiologia , Cistos/complicações , Cistos/congênito , Feminino , Monitorização Fetal , Feto/irrigação sanguínea , Humanos , Recém-Nascido , Monitorização Intraoperatória , Doenças da Boca/complicações , Doenças da Boca/congênito , Placenta/irrigação sanguínea , Gravidez , Fluxo Sanguíneo Regional/fisiologia , Ultrassonografia Pré-Natal
11.
Proc Natl Acad Sci U S A ; 98(15): 8276-82, 2001 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-11459964

RESUMO

Maintenance of genomic integrity and stable transmission of genetic information depend on a number of DNA repair processes. Failure to faithfully perform these processes can result in genetic alterations and subsequent development of cancer and other genetic diseases. In the eukaryote Saccharomyces cerevisiae, homologous recombination is the major pathway for repairing DNA double-strand breaks. The key role played by Rad52 in this pathway has been attributed to its ability to seek out and mediate annealing of homologous DNA strands. In this study, we find that S. cerevisiae Rad52 fused to green fluorescent protein (GFP) is fully functional in DNA repair and recombination. After induction of DNA double-strand breaks by gamma-irradiation, meiosis, or the HO endonuclease, Rad52-GFP relocalizes from a diffuse nuclear distribution to distinct foci. Interestingly, Rad52 foci are formed almost exclusively during the S phase of mitotic cells, consistent with coordination between recombinational repair and DNA replication. This notion is further strengthened by the dramatic increase in the frequency of Rad52 focus formation observed in a pol12-100 replication mutant and a mec1 DNA damage checkpoint mutant. Furthermore, our data indicate that each Rad52 focus represents a center of recombinational repair capable of processing multiple DNA lesions.


Assuntos
Reparo do DNA , DNA Fúngico/biossíntese , Proteínas de Ligação a DNA/metabolismo , Proteínas Fúngicas/metabolismo , Recombinação Genética , Proteínas de Saccharomyces cerevisiae , Núcleo Celular/metabolismo , Dano ao DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular , Mitose , Proteínas Serina-Treonina Quinases , Proteína Rad52 de Recombinação e Reparo de DNA , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/fisiologia , Fase S , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Transdução de Sinais
12.
J Child Neurol ; 16(2): 139-40, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11292222

RESUMO

The case report of a child with the diagnosis of a pineal tumor and severe, chronic sleep disorder is reported. Due to treatment of her lesion, the nighttime melatonin secretion was markedly suppressed. For 4(1/2) years, she has been receiving oral melatonin, which has greatly improved her sleep, without any adverse effects. Sleep difficulties should be considered in the management of pineal lesions. Melatonin replacement therapy is beneficial for those patients who have deficient melatonin synthesis.


Assuntos
Neoplasias Encefálicas/complicações , Terapia de Reposição Hormonal , Melatonina/uso terapêutico , Glândula Pineal , Pinealoma/complicações , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Adolescente , Neoplasias Encefálicas/cirurgia , Criança , Doença Crônica , Relação Dose-Resposta a Droga , Feminino , Humanos , Melatonina/administração & dosagem , Pinealoma/cirurgia , Distúrbios do Início e da Manutenção do Sono/etiologia , Resultado do Tratamento
13.
Gastrointest Endosc ; 53(4): 416-22, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11275879

RESUMO

BACKGROUND: A totally transoral outpatient procedure for the treatment of GERD would be appealing. METHODS: A multicenter trial was initiated that included 64 patients with GERD treated with an endoscopic suturing device. Inclusion criteria were 3 or more heartburn episodes per week while not taking medication, dependency on antisecretory medicine, and documented acid reflux by pH monitoring. Exclusion criteria were dysphagia, grade 3 or 4 esophagitis, obesity, and hiatus hernia greater than 2 cm in length. Patients underwent manometry, endoscopy, 24-hour pH monitoring, and symptom severity scoring before and after the procedure. Patients were randomized to a linear or circumferential plication configuration. Adverse procedural events were recorded. RESULTS: Mean 6-month symptom score changes demonstrated procedural efficacy. Heartburn severity and frequency as well as regurgitation all improved (p > 0.0001 for each). Twenty-four-hour pH monitoring showed improvement in number of episodes below pH of 4 at 3 and 6 months (p < 0.0007 and 0.0002) and percentage of total time the pH was less than 4 at 6 months (p < 0.011). Plication configuration did not affect symptoms or pH monitoring results. One patient had a self-contained suture perforation that was successfully treated with antibiotics. CONCLUSION: Endoscopic gastroplasty is safe. It is associated with reduced symptoms and medication use at 6 month follow-up in patients with uncomplicated GERD.


Assuntos
Refluxo Gastroesofágico/cirurgia , Gastroplastia/métodos , Gastroscopia/métodos , Refluxo Gastroesofágico/prevenção & controle , Gastroplastia/efeitos adversos , Azia/diagnóstico , Humanos , Concentração de Íons de Hidrogênio , Manometria , Qualidade de Vida , Técnicas de Sutura
14.
Cell ; 103(5): 711-21, 2000 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-11114328

RESUMO

Mutation and subsequent recombination events create genetic diversity, which is subjected to natural selection. Bacterial mismatch repair (MMR) deficient mutants, exhibiting high mutation and homologous recombination rates, are frequently found in natural populations. Therefore, we have explored the possibility that MMR deficiency emerging in nature has left some "imprint" in the sequence of bacterial genomes. Comparative molecular phylogeny of MMR genes from natural Escherichia coli isolates shows that, compared to housekeeping genes, individual functional MMR genes exhibit high sequence mosaicism derived from diverse phylogenetic lineages. This apparent horizontal gene transfer correlates with hyperrecombination phenotype of MMR-deficient mutators. The sequence mosaicism of MMR genes may be a hallmark of a mechanism of adaptive evolution that involves modulation of mutation and recombination rates by recurrent losses and reacquisitions of MMR gene functions.


Assuntos
Adenosina Trifosfatases , Pareamento Incorreto de Bases , Reparo do DNA , Proteínas de Ligação a DNA , Proteínas de Escherichia coli , Evolução Molecular , Alelos , Proteínas de Bactérias/genética , Escherichia coli/genética , Exodesoxirribonuclease V , Exodesoxirribonucleases/genética , Genótipo , Proteínas MutL , Proteína MutS de Ligação de DNA com Erro de Pareamento , Mutação , Fenótipo , Monoéster Fosfórico Hidrolases/genética , Filogenia , Reação em Cadeia da Polimerase , Pirofosfatases , Recombinação Genética , Salmonella typhimurium/genética
15.
Circ Res ; 87(4): 282-8, 2000 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-10948061

RESUMO

Neointimal hyperplasia at the site of surgical intervention is a common and deleterious complication of surgery for cardiovascular diseases. We hypothesized that direct delivery of a cell-permeable growth-arresting lipid via the balloon tip of an embolectomy catheter would limit neointimal hyperplasia after stretch injury. We have previously demonstrated that sphingolipid-derived ceramide arrested the growth of smooth muscle cell pericytes in vitro. Here, we show that ceramide-coated balloon catheters significantly reduced neointimal hyperplasia induced by balloon angioplasty in rabbit carotid arteries in vivo. This ceramide treatment decreased the number of vascular smooth muscle cells entering the cell cycle without inducing apoptosis. In situ autoradiographic studies demonstrated that inflating the balloon catheter forced cell-permeable ceramide into the intimal and medial layers of the artery. Intercalation of ceramide into vascular smooth muscle cells correlated with rapid inhibition of trauma-associated phosphorylation of extracellular signal-regulated kinase and protein kinase B. These studies demonstrate the utility of cell-permeable ceramide as a novel therapy for reducing neointimal hyperplasia after balloon angioplasty.


Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Lesões das Artérias Carótidas/tratamento farmacológico , Lesões das Artérias Carótidas/patologia , Ceramidas/farmacologia , Angioplastia Coronária com Balão/métodos , Animais , Apoptose/fisiologia , Lesões das Artérias Carótidas/metabolismo , Estenose das Carótidas/tratamento farmacológico , Estenose das Carótidas/metabolismo , Estenose das Carótidas/patologia , Modelos Animais de Doenças , Hiperplasia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/lesões , Músculo Liso Vascular/patologia , Complicações Pós-Operatórias/tratamento farmacológico , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/prevenção & controle , Coelhos , Túnica Íntima/enzimologia , Túnica Íntima/lesões , Túnica Íntima/patologia
16.
Am J Hum Genet ; 66(6): 1900-4, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10775530

RESUMO

We report an unusual molecular defect in the mitochondrially encoded ND1 subunit of NADH ubiquinone oxidoreductase (complex I) in a patient with mitochondrial myopathy and isolated complex I deficiency. The mutation is an inversion of seven nucleotides within the ND1 gene, which maintains the reading frame. The inversion, which alters three highly conserved amino acids in the polypeptide, was heteroplasmic in the patient's muscle but was not detectable in blood. This is the first report of a pathogenic inversion mutation in human mtDNA.


Assuntos
Inversão Cromossômica , DNA Mitocondrial/genética , Miopatias Mitocondriais/genética , Mutação/genética , NADH NADPH Oxirredutases/genética , Adulto , Sequência de Aminoácidos , Sequência de Bases , Sequência Conservada/genética , Análise Mutacional de DNA , Complexo I de Transporte de Elétrons , Humanos , Masculino , Mitocôndrias/enzimologia , Mitocôndrias/genética , Mitocôndrias/patologia , Miopatias Mitocondriais/enzimologia , Miopatias Mitocondriais/patologia , Miopatias Mitocondriais/fisiopatologia , Modelos Genéticos , Dados de Sequência Molecular , NADH NADPH Oxirredutases/deficiência , Polimorfismo de Fragmento de Restrição , Subunidades Proteicas , Recombinação Genética/genética
19.
Am J Gastroenterol ; 94(1): 194-9, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9934755

RESUMO

OBJECTIVE: Studies of tandem colonoscopies have reported that 15-25% of neoplastic polyps <1 cm in size and 0-6% of larger polyps are overlooked at the time of colonoscopy. We determined the miss rate and "true" 1-yr recurrence of neoplastic polyps in a population of patients reflecting a broad spectrum of different gastroenterology practice settings. METHODS: Patient data from several sources were examined for repeat colonoscopies performed on the same patient within 120 days of each other. Examination pairs were included for analysis if both colonoscopies had good preps and reached the cecum. The miss rate was calculated by two methods: 1) a pooled rate, the total number of polyps on all second examinations divided by the total number on both examinations, and 2) a within-person rate, the average of the individual miss-rates. We estimated a "true" 1-yr recurrence rate by subtracting the proportion of patients with a missed neoplastic polyp from the proportion of patients with a neoplastic polyp found at 1 yr. RESULTS: A total of 76 colonoscopy pairs a mean 47 days apart (range, 1-119 days) were identified from a total of approximately 15,000 examinations and used to calculate the overall miss rates. For the category "all polyps" (neoplastic and nonneoplastic polyps), 17% by the pooled method and 11% by the within-person method were missed. The corresponding rates for neoplastic polyps were 12% by the pooled method and 8% by the within-person method. A total of 17% of patients had one or more neoplastic polyps missed on the initial examination. The observed 1-yr recurrence rate was determined from 1,314 colonoscopy pairs performed a mean of 379 days apart and found to be 28% for neoplastic polyps. By comparing this to the proportion of patients with one or more missed neoplastic polyps, we found the true 1-yr recurrence of neoplastic polyps to be 11%. CONCLUSION: There is a significant colonoscopic miss rate for neoplastic polyps and "all polyps" in clinical practice that is comparable to that previously stated in special research settings. The within-person rate more accurately reflects the true colorectal polyp miss rate for any given colonoscopic exam than does the pooled rate. The difference between the observed 1-yr recurrence rate and the proportion of patients with a missed polyp represents the true 1-yr recurrence of neoplastic polyps.


Assuntos
Pólipos Adenomatosos/diagnóstico , Colonoscopia , Neoplasias Colorretais/diagnóstico , Recidiva Local de Neoplasia/diagnóstico , Pólipos Adenomatosos/cirurgia , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
20.
N Engl J Med ; 340(2): 101-7, 1999 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-9887161

RESUMO

BACKGROUND AND METHODS: Laboratory, clinical, and epidemiologic evidence suggests that calcium may help prevent colorectal adenomas. We conducted a randomized, double-blind trial of the effect of supplementation with calcium carbonate on the recurrence of colorectal adenomas. We randomly assigned 930 subjects (mean age, 61 years; 72 percent men) with a recent history of colorectal adenomas to receive either calcium carbonate (3 g [1200 mg of elemental calcium] daily) or placebo, with follow-up colonoscopies one and four years after the qualifying examination. The primary end point was the proportion of subjects in whom at least one adenoma was detected after the first follow-up endoscopy but up to (and including) the second follow-up examination. Risk ratios for the recurrence of adenomas were adjusted for age, sex, lifetime number of adenomas before the study, clinical center, and length of the surveillance period. RESULTS: The subjects in the calcium group had a lower risk of recurrent adenomas. Among the 913 subjects who underwent at least one study colonoscopy, the adjusted risk ratio for any recurrence of adenoma with calcium as compared with placebo was 0.85 (95 percent confidence interval, 0.74 to 0.98; P=0.03). The main analysis was based on the 832 subjects (409 in the calcium group and 423 in the placebo group) who completed both follow-up examinations. At least one adenoma was diagnosed between the first and second follow-up endoscopies in 127 subjects in the calcium group (31 percent) and 159 subjects in the placebo group (38 percent); the adjusted risk ratio was 0.81 (95 percent confidence interval, 0.67 to 0.99; P=0.04). The adjusted ratio of the average number of adenomas in the calcium group to that in the placebo group was 0.76 (95 percent confidence interval, 0.60 to 0.96; P=0.02). The effect of calcium was independent of initial dietary fat and calcium intake. CONCLUSIONS: Calcium supplementation is associated with a significant - though moderate - reduction in the risk of recurrent colorectal adenomas.


Assuntos
Adenoma/prevenção & controle , Carbonato de Cálcio/uso terapêutico , Neoplasias Colorretais/prevenção & controle , Recidiva Local de Neoplasia/prevenção & controle , Colonoscopia , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Risco , Resultado do Tratamento
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