Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 208
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Breast Cancer Res Treat ; 203(3): 599-612, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37897646

RESUMEN

PURPOSE: There are insufficient large-scale studies comparing the performance of screening mammography in women of different races. This study aims to compare the screening performance metrics across racial and age groups in the National Mammography Database (NMD). METHODS: All screening mammograms performed between January 1, 2008, and December 31, 2021, in women aged 30-100 years from 746 mammography facilities in 46 U.S. states in the NMD were included. Patients were stratified by 10-year age intervals and 5 racial groups (African American, American Indian, Asian, White, unknown). Incidence of risk factors (breast density, personal history, family history of breast cancer, age), and time since prior exams were compared. Five screening mammography metrics were calculated: recall rate (RR), cancer detection rate (CDR), positive predictive values for recalls (PPV1), biopsy recommended (PPV2) and biopsy performed (PPV3). RESULTS: 29,479,655 screening mammograms performed in 13,181,241 women between January 1, 2008, and December 31, 2021, from the NMD were analyzed. The overall mean performance metrics were RR 10.00% (95% CI 9.99-10.02), CDR 4.18/1000 (4.16-4.21), PPV1 4.18% (4.16-4.20), PPV2 25.84% (25.72-25.97), PPV3 25.78% (25.66-25.91). With advancing age, RR significantly decreases, while CDR, PPV1, PPV2, and PPV3 significantly increase. Incidence of personal/family history of breast cancer, breast density, age, prior mammogram availability, and time since prior mammogram were mostly similar across all races. Compared to White women, African American women had significantly higher RR, but lower CDR, PPV1, PPV2 and PPV3. CONCLUSIONS: Benefits of screening mammography increase with age, including for women age > 70 and across all races. Screening mammography is effective; with lower RR and higher CDR, PPV2, and PPV3 with advancing age. African American women have poorer outcomes from screening mammography (higher RR and lower CDR), compared to White and all women in the NMD. Racial disparity can be partly explained by higher rate of African American women lost to follow up.


Asunto(s)
Neoplasias de la Mama , Mamografía , Humanos , Femenino , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/epidemiología , Detección Precoz del Cáncer , Valor Predictivo de las Pruebas , Biopsia , Tamizaje Masivo
2.
Surg Endosc ; 38(7): 3672-3683, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38777894

RESUMEN

BACKGROUND: Anastomotic leakage (AL), a severe complication following colorectal surgery, arises from defects at the anastomosis site. This study evaluates the feasibility of predicting AL using machine learning (ML) algorithms based on preoperative data. METHODS: We retrospectively analyzed data including 21 predictors from patients undergoing colorectal surgery with bowel anastomosis at four Swiss hospitals. Several ML algorithms were applied for binary classification into AL or non-AL groups, utilizing a five-fold cross-validation strategy with a 90% training and 10% validation split. Additionally, a holdout test set from an external hospital was employed to assess the models' robustness in external validation. RESULTS: Among 1244 patients, 112 (9.0%) suffered from AL. The Random Forest model showed an AUC-ROC of 0.78 (SD: ± 0.01) on the internal test set, which significantly decreased to 0.60 (SD: ± 0.05) on the external holdout test set comprising 198 patients, including 7 (3.5%) with AL. Conversely, the Logistic Regression model demonstrated more consistent AUC-ROC values of 0.69 (SD: ± 0.01) on the internal set and 0.61 (SD: ± 0.05) on the external set. Accuracy measures for Random Forest were 0.82 (SD: ± 0.04) internally and 0.87 (SD: ± 0.08) externally, while Logistic Regression achieved accuracies of 0.81 (SD: ± 0.10) and 0.88 (SD: ± 0.15). F1 Scores for Random Forest moved from 0.58 (SD: ± 0.03) internally to 0.51 (SD: ± 0.03) externally, with Logistic Regression maintaining more stable scores of 0.53 (SD: ± 0.04) and 0.51 (SD: ± 0.02). CONCLUSION: In this pilot study, we evaluated ML-based prediction models for AL post-colorectal surgery and identified ten patient-related risk factors associated with AL. Highlighting the need for multicenter data, external validation, and larger sample sizes, our findings emphasize the potential of ML in enhancing surgical outcomes and inform future development of a web-based application for broader clinical use.


Asunto(s)
Fuga Anastomótica , Aprendizaje Automático , Humanos , Fuga Anastomótica/etiología , Fuga Anastomótica/epidemiología , Proyectos Piloto , Femenino , Masculino , Estudios Retrospectivos , Suiza/epidemiología , Anciano , Persona de Mediana Edad , Anastomosis Quirúrgica/efectos adversos , Cuidados Preoperatorios/métodos , Estudios de Factibilidad
3.
Langenbecks Arch Surg ; 409(1): 227, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39037448

RESUMEN

PURPOSE: Kono-S anastomosis, an antimesenteric, functional, end-to-end handsewn anastomosis, was introduced in 2011. The aim of this meta-analysis is to evaluate the safety and effectivity of the Kono-S technique. METHODS: A comprehensive search of MEDLINE (PubMed), Embase (Elsevier), Scopus (Elsevier), and Cochrane Central (Ovid) from inception to August 24th, 2023, was conducted. Studies reporting outcomes of adults with Crohn's disease undergoing ileocolic resection with subsequent Kono-S anastomosis were included. PRISMA and Cochrane guidelines were used to screen, extract and synthesize data. Primary outcomes assessed were endoscopic, surgical and clinical recurrence rates, as well as complication rates. Data were pooled using random-effects models, and heterogeneity was assessed with I² statistics. ROBINS-I and ROB2 tools were used for quality assessment. RESULTS: 12 studies involving 820 patients met the eligibility criteria. A pooled mean follow-up time of 22.8 months (95% CI: 15.8, 29.9; I2 = 99.8%) was completed in 98.3% of patients. Pooled endoscopic recurrence was reported in 24.1% of patients (95% CI: 9.4, 49.3; I2 = 93.43%), pooled surgical recurrence in 3.9% of patients (95% CI: 2.2, 6.9; I2 = 25.97%), and pooled clinical recurrence in 26.8% of patients (95% CI: 14, 45.1; I2 = 84.87%). The pooled complication rate was 33.7%. The most common complications were infection (11.5%) and ileus (10.9%). Pooled anastomosis leakage rate was 2.9%. CONCLUSIONS: Despite limited and heterogenous data, patients undergoing Kono-S anastomosis had low rates of surgical recurrence and anastomotic leakage with moderate rates of endoscopic recurrence, clinical recurrence and complications rate.


Asunto(s)
Anastomosis Quirúrgica , Enfermedad de Crohn , Humanos , Enfermedad de Crohn/cirugía , Anastomosis Quirúrgica/métodos , Anastomosis Quirúrgica/efectos adversos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/epidemiología , Íleon/cirugía , Recurrencia , Colon/cirugía
4.
Ther Umsch ; 80(9): 417-422, 2023 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-38095256

RESUMEN

INTRODUCTION: Despite the advances in the medical management, especially biologics, there are still clear indications for operative management of IBD. For Crohn's disease, surgical therapy plays an important role after failure of medical management and for treatment of complications. In recent years, however, there has been a change in the treatment philosophy of patients with isolated involvement of the ileocecal region, and for selected patients, primary surgical resection appears to be an equivalent treatment alternative to therapy with biologics. In ulcerative colitis, surgery offers the only curative option. In severe acute colitis, surgery is indicated when conservative treatment is not effective and/or when there is a risk of colonic perforation. Indications for elective surgery are failure of conservative therapy and malignant transformation. The ileoanal J-pouch reconstruction is the standard procedure after restorative proctocolectomy with excellent functional long-term results. The increasing complexity of indications and minimally invasive surgical techniques, as well as the demanding perioperative treatment, led to an increasing specialization in the surgical treatment of IBD patients, with IBD-surgeons collaborating as a team with gastroenterologists to optimize the outcome of IBD-patients.


Asunto(s)
Productos Biológicos , Colitis Ulcerosa , Enfermedad de Crohn , Enfermedades Inflamatorias del Intestino , Proctocolectomía Restauradora , Humanos , Enfermedades Inflamatorias del Intestino/cirugía , Enfermedades Inflamatorias del Intestino/etiología , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/cirugía , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/cirugía , Proctocolectomía Restauradora/efectos adversos , Proctocolectomía Restauradora/métodos , Complicaciones Posoperatorias/etiología , Productos Biológicos/uso terapéutico
5.
Surg Innov ; 29(2): 169-182, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34530655

RESUMEN

BACKGROUND: The abdominal wall expanding system (AWEX) was first applied in 2012 and published in 2017. This novel technique was developed to reconstruct complex incisional hernias and residual skin-grafted laparostoma after treatment of an open abdomen, when primary midline closure was impossible. The main aim was the anatomical reconstruction of the abdominal wall and the avoidance of dissecting techniques (component separation). METHODS: Between 2012 and 2019, 33 patients underwent AWEX hernia repair in three certified hernia centers. The retracted abdominal wall was stretched with the AWEX system intraoperatively for approximately 30 min. Hernia size was measured preoperatively, on CT, and intraoperatively. The gain in length on the lateral abdominal wall (decrease in width of the defect) after stretching and any residual midline gap were determined in the OR. RESULTS: 33 patients underwent AWEX procedures. Six cases were evaluated separately because of additional procedures (TAR, four cases) and preoperative application of botulinum toxin (two cases). The median (95% confidence interval) measured width of hernia defects was 13 (12-16) cm, the median gain in length on the lateral abdominal wall was 12 (10-15) cm. After median follow-up of 29 (12-54) months, one recurrence from the broken mesh was observed. No method-related complications occurred. CONCLUSION: Based on the 2017 and current results, the AWEX system represents an alternative or supplemental procedure to current techniques for complex abdominal wall reconstruction. The system proved again to be time-saving, safe, effective, and easy to learn. Further studies with enhanced technology are in progress.


Asunto(s)
Pared Abdominal , Hernia Ventral , Hernia Incisional , Pared Abdominal/cirugía , Estudios de Factibilidad , Hernia Ventral/cirugía , Herniorrafia/efectos adversos , Herniorrafia/métodos , Humanos , Hernia Incisional/cirugía , Recurrencia , Mallas Quirúrgicas
6.
HPB (Oxford) ; 24(11): 1898-1906, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35817694

RESUMEN

BACKGROUND: This is the first randomized trial to evaluate the efficacy of intraoperative cholangiography (IOC) and magnetic resonance cholangiopancreatography (MRCP) in patients with suspected CBDS. METHODS: This unblinded, multicenter RCT was conducted at five swiss hospitals. Eligibility criteria were suspected CBDS. Patients were randomized to IOC and laparoscopic cholecystectomy (LC), followed by endoscopic retrograde cholangiopancreatography (ERCP) if needed, or MRCP followed by ERCP if needed, and LC. Primary outcome was length of stay (LOS), secondary outcomes were cost, stone detection, and complication rates. RESULTS: 122 Patients were randomised to the IOC Group (63) or the MRCP group (59). Median LOS for the IOC and the MRCP groups were 4 days IQR [3, 6] and [4, 6], with an estimated increase of LOS of 1.2 days in the MRCP group (p = 0.0799) in the linear model. Median cost in the IOC and MRCP groups were 10 473 Swiss Francs (CHF) and 10 801 CHF, respectively (p = 0.694). CBDS were found in 24 and 12 patients in the IOC and the MRCP groups, respectively (p = 0.0387). The complication rate did not differ between both groups. CONCLUSION: There is equipoise between both pathways. IOC has a significantly higher diagnostic yield than MRCP. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT02351492: Radiological Investigation of Bile Duct Obstruction (RIBO).


Asunto(s)
Colecistectomía Laparoscópica , Cálculos Biliares , Humanos , Estudios Retrospectivos , Colangiografía , Cálculos Biliares/diagnóstico por imagen , Cálculos Biliares/cirugía , Cálculos Biliares/complicaciones , Colecistectomía Laparoscópica/efectos adversos , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Espectroscopía de Resonancia Magnética , Conducto Colédoco
7.
Crit Care Med ; 49(11): 1943-1954, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-33990098

RESUMEN

OBJECTIVES: The purpose of our study was to describe children with life-threatening bleeding. DESIGN: We conducted a prospective observational study of children with life-threatening bleeding events. SETTING: Twenty-four childrens hospitals in the United States, Canada, and Italy participated. SUBJECTS: Children 0-17 years old who received greater than 40 mL/kg total blood products over 6 hours or were transfused under massive transfusion protocol were included. INTERVENTIONS: Children were compared according bleeding etiology: trauma, operative, or medical. MEASUREMENTS AND MAIN RESULTS: Patient characteristics, therapies administered, and clinical outcomes were analyzed. Among 449 enrolled children, 55.0% were male, and the median age was 7.3 years. Bleeding etiology was 46.1% trauma, 34.1% operative, and 19.8% medical. Prior to the life-threatening bleeding event, most had age-adjusted hypotension (61.2%), and 25% were hypothermic. Children with medical bleeding had higher median Pediatric Risk of Mortality scores (18) compared with children with trauma (11) and operative bleeding (12). Median Glasgow Coma Scale scores were lower for children with trauma (3) compared with operative (14) or medical bleeding (10.5). Median time from bleeding onset to first transfusion was 8 minutes for RBCs, 34 minutes for plasma, and 42 minutes for platelets. Postevent acute respiratory distress syndrome (20.3%) and acute kidney injury (18.5%) were common. Twenty-eight-day mortality was 37.5% and higher among children with medical bleeding (65.2%) compared with trauma (36.1%) and operative (23.8%). There were 82 hemorrhage deaths; 65.8% occurred by 6 hours and 86.5% by 24 hours. CONCLUSIONS: Patient characteristics and outcomes among children with life-threatening bleeding varied by cause of bleeding. Mortality was high, and death from hemorrhage in this population occurred rapidly.


Asunto(s)
Transfusión Sanguínea/estadística & datos numéricos , Servicios Médicos de Urgencia , Hemorragia/terapia , Adolescente , Antifibrinolíticos/uso terapéutico , Transfusión de Componentes Sanguíneos/estadística & datos numéricos , Canadá , Niño , Preescolar , Femenino , Hemorragia/mortalidad , Humanos , Lactante , Recién Nacido , Italia , Masculino , Estudios Prospectivos , Estados Unidos
8.
BMC Med Res Methodol ; 21(1): 275, 2021 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-34865631

RESUMEN

BACKGROUND: The application of advanced imaging in pediatric research trials introduces the challenge of how to effectively handle and communicate incidental and reportable findings. This challenge is amplified in underserved populations that experience disparities in access to healthcare as recommendations for follow-up care may be difficult to coordinate. Therefore, the purpose of the present report is to describe the process for identifying and communicating findings from a research MRI to low-income Latino children and families. METHODS: Latino adolescents (n = 86) aged 12-16 years old with obesity and prediabetes underwent a research MRI (3 Tesla Philips Ingenia®) as part of a randomized controlled diabetes prevention trial. The research MRIs were performed at baseline and 6 months to assess changes in whole-abdominal fat distribution and organ fat in response to the intervention. An institutional pathway was developed for identifying and reporting findings to participants and families. The pathway was developed through a collaborative process with hospital administration, research compliance, radiology, and the research team. All research images were reviewed by a board-certified pediatric radiologist who conveyed findings to the study pediatrician for determination of clinical actionability and reportability to children and families. Pediatric sub-specialists were consulted as necessary and a primary care practitioner (PCP) from a free community health clinic agreed to receive referrals for uninsured participants. RESULTS: A total of 139 images (86 pre- and 53 post-intervention) were reviewed with 31 findings identified and 23 deemed clinically actionable and reportable. The only reportable finding was severely elevated liver fat (> 10%, n = 14) with the most common and concerning incidental findings being horseshoe kidney (n = 1) and lung lesion (n = 1). The remainder (n = 7) were less serious. Of youth with a reportable or incidental finding, 18 had a PCP but only 7 scheduled a follow-up appointment. Seven participants without a PCP were referred to a safety-net clinic for follow-up. CONCLUSIONS: With the increased utilization of high-resolution imaging in pediatric research, additional standardization is needed on what, when, and how to return incidental and reportable findings to participants, particularly among historically underrepresented populations that may be underserved in the community. TRIAL REGISTRATION: Preventing Diabetes in Latino Youth, NCT02615353.


Asunto(s)
Diabetes Mellitus , Estado Prediabético , Adolescente , Niño , Hispánicos o Latinos , Humanos , Imagen por Resonancia Magnética , Obesidad
9.
Dig Surg ; 38(2): 158-165, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33640885

RESUMEN

BACKGROUND: This survey aimed to register changes determined by the COVID-19 pandemic on pancreatic surgery in a specific geographic area (Germany, Austria, and Switzerland) to evaluate the impact of the pandemic and obtain interesting cues for the future. METHODS: An online survey was designed using Google Forms focusing on the local impact of the pandemic on pancreatic surgery. The survey was conducted at 2 different time points, during and after the lockdown. RESULTS: Twenty-five respondents (25/56) completed the survey. Many aspects of oncological care have been affected with restrictions and delays: staging, tumor board, treatment selection, postoperative course, adjuvant treatments, outpatient care, and follow-up. Overall, 60% of respondents have prioritized pancreatic cancer patients according to stage, age, and comorbidities, and 40% opted not to operate high-risk patients. However, for 96% of participants, the standards of care were guaranteed. DISCUSSION/CONCLUSIONS: The first wave of the COVID-19 pandemic had an important impact on pancreatic cancer surgery in central Europe. Guidelines for prompt interventions and prevention of the spread of viral infections in the surgical environment are needed to avoid a deterioration of care in cancer patients in the event of a second wave or a new pandemic. High-volume centers for pancreatic surgery should be preferred and their activity maintained. Virtual conferences have proven to be efficient during this pandemic and should be implemented in the near future.


Asunto(s)
COVID-19/prevención & control , Accesibilidad a los Servicios de Salud/tendencias , Pancreatectomía/tendencias , Neoplasias Pancreáticas/cirugía , Pautas de la Práctica en Medicina/tendencias , Cuidados Posteriores/métodos , Cuidados Posteriores/normas , Cuidados Posteriores/tendencias , Actitud del Personal de Salud , COVID-19/epidemiología , Europa (Continente)/epidemiología , Encuestas de Atención de la Salud , Accesibilidad a los Servicios de Salud/normas , Humanos , Control de Infecciones/métodos , Control de Infecciones/tendencias , Estadificación de Neoplasias , Pancreatectomía/normas , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/patología , Pandemias , Aceptación de la Atención de Salud , Atención Perioperativa/métodos , Atención Perioperativa/normas , Atención Perioperativa/tendencias , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina/normas , Tiempo de Tratamiento/normas , Tiempo de Tratamiento/tendencias
10.
Langenbecks Arch Surg ; 406(1): 121-129, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33083847

RESUMEN

PURPOSE: The management of perforated diverticulitis with generalized peritonitis is still controversial and no preferred standardized therapeutic approach has been determined. We compared surgical outcomes between Hartmann's procedure (HP) and primary anastomosis (PA) in patients with Hinchey III and IV perforated diverticulitis. METHODS: Multicenter retrospective analysis of 131 consecutive patients with Hinchey III and IV diverticulitis operated either with HP or PA from 2015 to 2018. Postoperative morbidity was compared after adjustment for known risk factors in a multivariate logistic regression. RESULTS: Sixty-six patients underwent HP, while PA was carried out in 65 patients, 35.8% of those were defunctioned. HP was more performed in older patients (74.6 vs. 61.2 years, p < .001), with Hinchey IV diverticulitis (37% vs. 7%, p < .001) and in patients with worse prognostic scores (P-POSSUM Physiology Score, p < .001, Charlson Comorbidity Index p < .001). Major morbidity and mortality were higher in HP compared to PA (30.3% vs. 9.2%, p = .002 and 10.6% vs. 0%, p = .007, respectively) with lower stoma reversal rate (43.9% vs. 86.9%, p < .001). In a multivariate logistic regression, PA was independently associated with lower postoperative morbidity and mortality (OR 0.24, 95% CI 0.06-0.96, p = .044). CONCLUSIONS: In comparison to PA, HP is associated with a higher morbidity, higher mortality, and a lower stoma reversal rate. Although a higher prevalence of risk factors in HP patients may explain these outcomes, a significant increase in morbidity and mortality persisted in a multivariate logistic regression analysis that was stratified for the identified risk factors.


Asunto(s)
Diverticulitis del Colon , Diverticulitis , Perforación Intestinal , Peritonitis , Anciano , Anastomosis Quirúrgica , Colostomía , Diverticulitis/cirugía , Diverticulitis del Colon/cirugía , Humanos , Perforación Intestinal/epidemiología , Perforación Intestinal/cirugía , Modelos Logísticos , Peritonitis/cirugía , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento
11.
Ther Umsch ; 78(10): 605-613, 2021.
Artículo en Alemán | MEDLINE | ID: mdl-34844431

RESUMEN

Pancreatic cancer Abstract. Pancreatic cancer is the second most common cancer in the GI tract in Europe and North America and it is associated with a poor prognosis due to its aggressive tumor biology. Each year the number of deaths from pancreatic cancer is almost the same as the number of new cases diagnosed. Most of the pancreatic cancers develop from exocrine cells, while endocrine pancreatic cancers (i. e., neuroendocrine tumors or islet cell tumors) are uncommon. The term "pancreatic cancer" is typically used to refer to pancreatic adenocarcinoma, which will be the focus of this paper. Despite the introduction of multimodal therapy concepts, advanced surgical techniques, and increasing surgical specialization, overall survival in pancreatic cancer has not significantly improved. Early and complete surgical tumor resection remains the only curative option; however, this is rarely achieved, mainly due to the advanced stage at diagnosis. Adjuvant chemotherapy has become the gold standard after upfront resection. Neoadjuvant chemotherapy regimens, such as FOLFIRINOX, represent a valid option in order to achieve complete surgical tumor resection in more advanced cases. However, the overall uptake of this promising concept is very low.


Asunto(s)
Adenocarcinoma , Neoplasias Pancreáticas , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quimioterapia Adyuvante , Humanos , Terapia Neoadyuvante , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/terapia
12.
Proteins ; 88(3): 527-539, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31589792

RESUMEN

The selectivity filter (SF) of bacterial voltage-gated sodium channels consists of four glutamate residues arranged in a C4 symmetry. The protonation state population of this tetrad is unclear. To address this question, we simulate the pore domain of bacterial voltage-gated sodium channel of Magnetococcus sp. (Nav Ms) through constant pH methodology in explicit solvent and free energy perturbation calculations. We find that at physiological pH the fully deprotonated as well as singly and doubly protonated states of the SF appear feasible, and that the calculated pKa decreases with each additional bound ion, suggesting that a decrease in the number of ions in the pore can lead to protonation of the SF. Previous molecular dynamics simulations have suggested that protonation can lead to a decrease in the conductance, but no pKa calculations were performed. We confirm a decreased ionic population of the pore with protonation, and also observe structural symmetry breaking triggered by protonation; the SF of the deprotonated channel is closest to the C4 symmetry observed in crystal structures of the open state, while the SF of protonated states display greater levels of asymmetry which could lead to transition to the inactivated state which possesses a C2 symmetry in the crystal structure. We speculate that the decrease in the number of ions near the mouth of the channel, due to either random fluctuations or ion depletion due to conduction, could be a self-regulatory mechanism resulting in a nonconducting state that functionally resembles inactivated states.


Asunto(s)
Alphaproteobacteria/química , Proteínas Bacterianas/química , Protones , Sodio/química , Canales de Sodio Activados por Voltaje/química , Alphaproteobacteria/metabolismo , Proteínas Bacterianas/metabolismo , Sitios de Unión , Cationes Monovalentes , Cristalografía por Rayos X , Concentración de Iones de Hidrógeno , Transporte Iónico , Cinética , Simulación de Dinámica Molecular , Unión Proteica , Conformación Proteica en Hélice alfa , Dominios y Motivos de Interacción de Proteínas , Sodio/metabolismo , Termodinámica , Canales de Sodio Activados por Voltaje/metabolismo
13.
Radiology ; 296(1): 32-41, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32427557

RESUMEN

Background The literature supports the use of short-interval follow-up as an alternative to biopsy for lesions assessed as probably benign, Breast Imaging Reporting and Data System (BI-RADS) category 3, with an expected malignancy rate of less than 2%. Purpose To assess outcomes from 6-, 12-, and 24-month follow-up of probably benign findings first identified at recall from screening mammography in the National Mammography Database (NMD). Materials and Methods This retrospective study included women recalled from screening mammography with BI-RADS category 3 assessment at additional evaluation from January 2009 through March 2018 from 471 NMD facilities. Only the first BI-RADS category 3 occurrence for women aged 25 years or older with no personal history of breast cancer was analyzed, with biopsy or 2-year imaging follow-up. Cancer yield and positive predictive value of biopsies performed (PPV3) were determined at each follow-up. Results Among 45 202 women (median age, 55 years; range, 25-90 years) with a BI-RADS category 3 lesion, 1574 (3.5%) underwent biopsy at the time of lesion detection, yielding 72 cancers (cancer yield, 4.6%; 72 of 1574 women). For the remaining 43 628 women who accepted surveillance, 922 were seen within 90 days (with 78 lesions biopsied and 12 [15%] classified as malignant). The women still in surveillance (31 465 of 43 381 women [72.5%]) underwent follow-up mammography at 6 months. Of 3001 (9.5%) lesions biopsied, 456 (15.2%) were malignant (cancer yield, 1.5%; 456 of 31 465 women; 95% confidence interval [CI]: 1.3%, 1.6%). Among 18 748 of 25 997 women (72.1%) in surveillance who underwent follow-up at 12 months, 1219 (6.5%) underwent biopsy with 230 (18.9%) malignant lesions found (cancer yield, 1.2%; 230 of 18 748 women; 95% CI: 1.1%, 1.4%). Through 2-year follow-up, the biopsy rate was 11.2% (4894 of 43 628 women) with a cancer yield of 1.86% (810 malignancies found among 43 628 women; 95% CI: 1.73%, 1.98%) and a PPV3 of 16.6% (810 malignancies found among 4894 women). Conclusion In the National Mammography Database, Breast Imaging Reporting and Data System (BI-RADS) category 3 use is appropriate, with 1.86% cumulative cancer yield through 2-year follow-up. Of 810 malignancies, 468 (57.8%) were diagnosed at or before 6 months, validating necessity of short-interval follow-up of mammographic BI-RADS category 3 findings. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Moy in this issue.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/epidemiología , Bases de Datos Factuales/estadística & datos numéricos , Mamografía/métodos , Sistemas de Información Radiológica/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Mama/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Estudios Retrospectivos
14.
J Phys Chem A ; 124(19): 3851-3858, 2020 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-32312049

RESUMEN

Fluorinated organic compounds are ubiquitous in the pharmaceutical and agricultural industries. To better discern the mode of action of these compounds, it is critical to understand the strengths of hydrogen bonds involving fluorine. While established techniques can determine these strengths for intermolecular complexes, there is no analogous scheme for intramolecular hydrogen bonds. This work uses 1H nuclear magnetic resonance spectroscopy to measure the strength of intramolecular hydrogen bonds in ortho-substituted phenols. Titration of each phenol with DMSO in CCl4 yields a free energy of binding (ΔG). Subtraction of this value from the ΔG of binding of the standard, 4-fluorophenol, is shown to give the difference in ΔG for the cis and trans isomers of the ortho-substituted phenols. This difference is conventionally taken to be approximately equal to the ΔG of the intramolecular hydrogen bond. These data complement theoretical methods, which yield slightly larger ΔGs. Both theory and experiment point to a weak intramolecular hydrogen bond in 2-fluorophenol. The other 2-X-phenols have stronger hydrogen bonds, following the order F < Cl ≈ Br < OCH3. The methodology developed here can be readily applied to other systems with intramolecular hydrogen bonds.

15.
Magn Reson Chem ; 58(10): 957-968, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32529717

RESUMEN

A corona, consisting of 18 carbon atoms bearing 12 hydroxy groups in a continuous hydrogen-bonded chain, is built up by alternating degenerate conformations of alternating alkane-1,2-diol and 1,3-diol motifs. Geometries, proton nuclear magnetic resonance shifts and interaction energies for the dodecahydroxycyclo-octadecane and selected fragments are determined by density functional calculations at the B3LYP/6-311+G(d,p) level. Cooperative effects of O-H⋯O-H bonding are evident from the simple juxtaposition of these two motifs with a common OH group in butane-1,2,4-triol conformers. Bracketing a 1,2-diol motif with two 1,3-diol motifs in hexane-1,3,4,6-tetrol leads to a structure in which the 1,2-diol motif displays a bond critical point for hydrogen bonding. This is associated with enhancement of the shift of the hydrogen-bonded OH proton and of the corresponding H⋯O interaction energy. The full corona has a complete outer ring of O-H⋯O-H bond paths, and an inner ring of bond paths, due to C-H⋯H-C hydrogen-hydrogen bonding, which result in a central ring critical point. The topological O-H⋯O-H hydrogen bond, never seen in simple alkane-1,2-diols, is associated with cooperative enhancement of the H⋯O interaction energy, but this is not a necessary condition for a bond path: values for topological C-H⋯H-C hydrogen-hydrogen bonds can be as low as -0.4 kcal mol-1 .

16.
Ther Umsch ; 77(9): 441-448, 2020 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-33146097

RESUMEN

Adrenal tumors Abstract. The term 'adrenal tumor' describes benign and malignant mass lesions of the adrenal gland, including primary adrenal tumors and metastases from extra-adrenal origin. With the widespread use of imaging technique, adrenal tumors have become increasingly detected as 'incidentalomas'. The detection of an adrenal tumor raises two questions: Is the mass malignant? Is the mass hormonally active? Whereas the evaluation for malignancy is based on specific imaging characteristics (imaging phenotype), a targeted clinical examination and specific biochemical tests are required to assess for hormonal secretion. An adrenal mass < 4 cm with clear benign features on imaging and with a normal hormonal workup does not require treatment. If malignancy is suspected further diagnostic procedures and / or adrenalectomy are indicated. For hormonally active tumors surgery is generally considered the treatment of choice; however, the decision for surgery has to be individualized for aldosterone-secreting tumors and for cortisol-secreting tumors with only mild cushing's syndrome. Also in patients with large tumors (> 4 cm), and in cases with non-conclusive evaluation for malignancy or hormonal activity, the decision for further management has to be made on an individual basis. A minimally invasive surgical approach may be considered in adrenal tumors < 6 cm and without local infiltration of adjacent structures. Both laparoscopic (transabdominal) and retroperitoneoscopic techniques are possible. The surgical outcome depends on the surgeon's experience. A close interdisciplinary collaboration is mandatory in the evaluation and treatment of adrenal tumors.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales , Síndrome de Cushing , Laparoscopía , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Neoplasias de las Glándulas Suprarrenales/cirugía , Adrenalectomía , Síndrome de Cushing/cirugía , Síndrome de Cushing/terapia , Humanos
17.
Dis Colon Rectum ; 62(8): 997-1004, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30998528

RESUMEN

BACKGROUND: Postoperative ileus after colorectal surgery is a frequent problem that significantly prolongs hospital stay and increases perioperative costs. OBJECTIVE: The aim was to evaluate the effect of standardized coffee intake on postoperative bowel movement after elective laparoscopic colorectal resection. DESIGN: This is a prospective randomized controlled trial that was conducted between September 2014 and December 2016. SETTINGS: This study was performed in a public cantonal hospital in Switzerland with accreditation for colon and rectum cancer surgery. PATIENTS: Patients who underwent elective colorectal surgery were included. INTERVENTIONS: Patients were randomly assigned either to the intervention group receiving coffee or the control group receiving tea. A total of 150 mL of the respective beverage was drunk 3 times per day every postoperative day until discharge. MAIN OUTCOME MEASURES: The primary end point was time to first bowel movement. Secondary end points included the use of laxative, insertion of a nasogastric tube, length of hospital stay, and postoperative complications. RESULTS: A total of 115 patients were randomly assigned: 56 were allocated to the coffee group and 59 to the tea group. After coffee intake, the first bowel movement occurred after a median of 65.2 hours versus 74.1 hours in the control group (intention-to-treat analysis; p = 0.008). The HR for earlier first bowel movement after coffee intake was 1.67 (p = 0.009). In the per-protocol analysis, hospital stay was shorter in the coffee group (6 d in the coffee group vs 7 d in the tea group; p = 0.043). LIMITATIONS: The rate of protocol violation, mostly coffee consumption in the tea arm, was relatively high, even if patients were clearly instructed not to consume coffee if they were in the tea arm. CONCLUSIONS: Coffee intake after elective laparoscopic colorectal resection leads to faster recovery of bowel function. Therefore, coffee intake represents a simple and effective strategy to prevent postoperative ileus. See Video Abstract at http://links.lww.com/DCR/A955. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT02469441.


Asunto(s)
Café , Colectomía/efectos adversos , Procedimientos Quirúrgicos Electivos/efectos adversos , Ileus/prevención & control , Laparoscopía/efectos adversos , Complicaciones Posoperatorias/prevención & control , Anciano , Colectomía/métodos , Neoplasias Colorrectales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Ileus/epidemiología , Ileus/etiología , Incidencia , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Prospectivos , Suiza/epidemiología , Factores de Tiempo , Resultado del Tratamiento
18.
Neurourol Urodyn ; 38(7): 1944-1952, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31310369

RESUMEN

AIMS: To assess the effectiveness and patient satisfaction of pelvic floor muscle training (PFMT) guided by an intravaginal accelerometer-based system for the treatment of female urinary incontinence (UI). METHODS: Premenopausal women with mild-to-moderate stress or mixed UI were recruited to participate in PFMT with an accelerometer-based system for 6 weeks with supervision. Objective outcomes included pelvic floor muscle (PFM) contraction duration, number of contractions in 15 seconds, and angular displacement of the accelerometer relative to earth during PFM contraction. Subjective outcomes and quality-of-life were assessed with validated, condition-specific questionnaires. Results are presented as means, standard error of the mean, and 95% confidence intervals unless otherwise indicated. RESULTS: Twenty-three women (age 42.0 ± 10.7 years, mean ± standard deviation) completed the study. Scores on the Urogenital Distress Inventory (UDI) decreased from 36.7 ± 4.7 at baseline to 1.45 ± 0.8 at 6 weeks (P < .0001). The Patient's Global Impression of Severity score decreased from 1.5 ± 0.1 to 0.2 ± 0.1 (P < .0001) at study endpoint. At 6 weeks, the PFM contraction duration increased from 13 ± 2.6 at baseline to 187 ± 9.6 seconds (P < .0001). Repeated contractions in 15 seconds increased from 5.9 ± 0.4 at enrollment to 9.6 ± 0.5 at 6 weeks (P < .0001). Maximum pelvic floor angle (a measure of lift) increased from 65.1 ± 2.0° to 81.1 ± 1.8° (P < .0001). Increasing PFM contraction duration and maximum pelvic floor angle correlated with decreasing UDI-6 scores, r = -0.87, P = .01; r = -0.97, P = .0003, respectively. No device-related adverse events occurred. CONCLUSIONS: Pilot testing of this accelerometer-based system demonstrates improvements in objective PFM measures, patient-reported UI severity and condition-specific quality of life, with results evident after 1 week of use.


Asunto(s)
Acelerometría , Terapia por Ejercicio/métodos , Diafragma Pélvico/fisiopatología , Calidad de Vida , Incontinencia Urinaria/terapia , Adulto , Femenino , Humanos , Persona de Mediana Edad , Proyectos Piloto , Encuestas y Cuestionarios , Resultado del Tratamiento , Incontinencia Urinaria/fisiopatología , Incontinencia Urinaria de Esfuerzo/terapia
19.
J Phys Chem A ; 123(35): 7651-7660, 2019 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-31398057

RESUMEN

For 2-X-ethanols, where X = F, OH, or NH2, the gauche conformer is favored over the trans conformer by at least 2 kcal/mol. Initially, this preference, ΔE, was attributed to an intramolecular hydrogen bond, IMHB, between the OH and X groups. Over the years, this conclusion has been challenged by two major arguments. One claim is that the entirety of ΔE can be accounted for by the gauche effect. Against this, calculations using five different methods show that the maximum contribution of the gauche effect to ΔE is less than 1 kcal/mol. A second argument employs the quantum theory of atoms in molecules to contend that the absence of a bond critical point (BCP) between the OH and X groups in 2-X-ethanols denotes the lack of an IMHB. By looking at the 2-X-ethanols at fixed XCCO torsional angles ranging from 0° to 60°, it is shown that the BCP criterion is inconsistent with other properties such as energy, bond lengths, and stretching frequencies. These inconsistencies are removed when the theory of noncovalent interactions is used. The IMHBs in 2-X-ethanols are found to be similar in form but smaller in magnitude than their intermolecular counterparts. This work concludes that 2-X-ethanols form IMHBs.

20.
World J Surg ; 43(7): 1669-1675, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30824961

RESUMEN

OBJECTIVES: Incisional hernia, a serious complication after laparotomy, is associated with high morbidity and costs. This trial examines the value of prophylactic intraperitoneal onlay mesh to reduce the risk of incisional hernia after a median follow-up time of 5.3 years. METHODS: We conducted a parallel group, open-label, single center, randomized controlled trial (NCT01003067). After midline incision, the participants were either allocated to abdominal wall closure according to Everett with a PDS-loop running suture reinforced by an intraperitoneal composite mesh strip (Group A) or the same procedure without the additional mesh strip (Group B). RESULTS: A total of 276 patients were randomized (Group A = 131; Group B = 136). Follow-up data after a median of 5.3 years after surgery were available from 183 patients (Group A = 95; Group B = 88). Incisional hernia was diagnosed in 25/95 (26%) patients in Group A and in 46/88 (52%) patients in Group B (risk ratio 0.52; 95% CI 0.36-0.77; p < 0.001). Eighteen patients with asymptomatic incisional hernia went for watchful waiting instead of hernia repair and remained free of symptoms after of a median follow-up of 5.1 years. Between the second- and fifth-year follow-up period, no complication associated with the mesh could be detected. CONCLUSION: The use of a composite mesh in intraperitoneal onlay position significantly reduces the risk of incisional hernia during a 5-year follow-up period. TRIAL REGISTRATION NUMBER: Ref. NCT01003067 (clinicaltrials.gov).


Asunto(s)
Técnicas de Cierre de Herida Abdominal , Hernia Ventral/prevención & control , Hernia Incisional/prevención & control , Mallas Quirúrgicas , Abdomen/cirugía , Estudios de Seguimiento , Hernia Ventral/etiología , Hernia Ventral/cirugía , Herniorrafia , Humanos , Hernia Incisional/etiología , Hernia Incisional/cirugía , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/cirugía , Mallas Quirúrgicas/efectos adversos , Suturas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA