The constant force continuous molecular dynamics for potentials with multiple discontinuities.

In this work, we present an extension of the constant force approach [P. Orea and G. Odriozola, J. Chem. Phys. 138, 214105 (2013)] to the case of potentials with multiple discontinuities. To illustrate the method, we selected the square well potential of range λ=1.5 that exhibits two discontinuities. Square well single phase properties, vapor-liquid phase diagram, and surface tension were calculated and compared with available simulation data. Besides, we analyzed the internal energies of a square well plus a square shoulder potential having three discontinuities. For both potentials, a good agreement has been found when compared with results of other simulation techniques (discontinuous molecular dynamics and Monte Carlo methods). This extension can be easily implemented to more general and efficient continuous molecular dynamics packages (HOOMD, GROMACS, NAMD, etc.).

Intususpección en el adulto. Diagnóstico por TAC / No disponible

No disponible

Pseudoquiste traumático de páncreas / Traumatic pseudocyst of the pancreas

No disponible

Limitations of the pelvic examination for evaluation of the female pelvic organs.

OBJECTIVE: To assess factors influencing an accurate pelvic examination under the best possible circumstances. METHODS: Before undergoing laparoscopy or laparotomy, 84 women under general anesthesia underwent pelvic examinations by an attending gynecologist, a gynecology resident, and a medical student blinded to the indication for surgery. Surgical findings were compared with the examiners' findings. Dependent variables (uterine size, uterine contour, and presence of adnexal masses) and effect modifiers (examiner experience and body mass index) were analyzed. RESULTS: The overall pelvic examination was accurate 70.2% of the time for attending gynecologists, 64.0% for residents, and 57.3% for medical students. The sensitivity to detect adnexal masses was much lower than the sensitivity to assess uterine size or uterine contour. Obesity noticeably reduced detection of adnexal masses. CONCLUSION: The bimanual examination appears to be a limited screening test for the female upper genital tract even under the best possible circumstances. Uterine assessment appears to be more accurate than adnexal assessment.

Oclusión intestinal por carcinoma colorrectal en el anciano. Presentación clínica y utilidad de la anamnesis y exploración física / Intestinal occlusion due to colorectal carcinoma in the aged. Clinical presentation and usefulness of anamnesis and physical examination

El síndrome de distensión visceral es el diagnóstico más frecuente en nuestro medio en pacientes ancianos que acuden a Urgencias por presentar dolor abdominal agudo (DAA). La oclusión intestinal representa el 59,6 por ciento de estos pacientes y el carcinoma colorrectal es la primera causa (46,6 por ciento) en la población de edad avanzada. Objetivos: Una exhaustiva revisión de la bibliografía nos ha llevado a verificar la escasez de trabajos que hacen referencia a la sensibilidad de la historia clínica en el proceso diagnóstico del dolor abdominal agudo en el anciano en general y en la oclusión intestinal por carcinoma colorrectal en particular, siendo éste el objetivo fundamental de nuestro estudio. Métodos: Cirujanos, gastroenterólogos y expertos en Medicina de Urgencia elaboramos un cuestionario especialmente diseñado para evaluar la semiología del DAA y que aplicamos a pacientes de edad igual o mayor a 65 años que acudían a Urgencias por este motivo. Resultados: Una historia clínica y examen físico efectuados con rigor es capaz de predecir con acierto el diagnóstico en más de la mitad de los casos de los pacientes ancianos que acuden a Urgencias presentando una oclusión intestinal por carcinoma colorrectal. Este porcentaje se eleva al 75 por ciento cuando sumamos la aportación de las pruebas complementarias rutinarias. Conclusiones: La historia clínica, aún con las limitaciones que comporta en este grupo de edad, constituye el documento principal del proceso diagnóstico en el DAA (AU)

The accuracy of the rectovaginal examination in detecting cul-de-sac disease in patients under general anaesthesia.

BACKGROUND: The rectovaginal examination is frequently used as an adjunct to a bimanual examination. The accuracy of rectovaginal examination in detecting cul-de-sac disease under ideal circumstances of the operating room was studied. METHODS: Fifty-two attending physicians and 30 residents were selected on experience and immediate availability to evaluate the presence of uterosacral nodularity and external rectal compression on 140 women undergoing general anaesthesia, followed by laparoscopy or laparotomy, at an academic medical centre. Physicians were masked to the indications for surgery and procedure ranging from diagnostic laparoscopy to laparotomy for suspected malignancy. RESULTS: Mean patient body mass index (BMI) was 26.1 kg/m2 and nearly one-third had had previous surgery. Based on the surgical findings, cul-de-sac disease was common, including uterosacral nodularity (5.8%) and rectal compression (10.1%). Both sensitivity and positive predictive value of the rectovaginal examination for detecting uterosacral nodularity were zero, whereas specificity approached 95%. Accuracy in detecting rectal compression was somewhat better with a sensitivity of 34%, specificity 96.7% and positive predictive value 55.6%. Neither examiner-years of experience nor the laterality of the dominant or examining hand affected the accuracy of the rectovaginal examination. CONCLUSIONS: The rectovaginal examination has marked limitations despite the controlled circumstances of the operating room including general anaesthesia, an empty bladder and ideal patient positioning. As suspected, the specificity of the rectal examination is high due to the low prevalence of disease. However, the sensitivity of the rectovaginal examination is very low, limiting its capacity as a screening test.

Using a belly board device to reduce the small bowel volume within pelvic radiation fields in women with postoperatively treated cervical carcinoma.

OBJECTIVE: The purpose of this study was to attempt to reduce the small bowel volume in cervical cancer patients undergoing radiation therapy using the belly board device and a four-field technique. METHODS: From 1994 through 1997, twenty-one patients with cervical cancer were referred to the University of Minnesota Medical Center and underwent surgical staging with or without radical hysterectomy followed by postoperative external beam radiotherapy for various indications including positive nodal disease (n = 11), lymph-vascular space invasion (n = 2), poor histology (n = 3), parametrial disease (n = 4), and positive vaginal margin (n = 1). RESULTS: The median age of the 21 patients was 42 years (25-54 years) and a median external beam pelvic radiation dose of 4775 cGy (range, 4200-5075 cGy) was administered. All patients were evaluated for amount of small bowel in the field in both the supine and prone positions, with and without the belly board device (BBD), using a four-field technique. With a full bladder, abdominal radiographs with contrast were obtained to evaluate the volume of small bowel within the radiation fields. In most patients, the BBD was effective at minimizing the amount of small bowel in the lateral fields, whereas a prone position on the treatment table (without the BBD) spared the most small bowel with the AP/PA fields. Therefore over a 2-day cycle, the most small bowel sparing was obtained with the patients treated prone on the BBD for the lateral fields on Day 1 and prone on the table for the AP/PA fields on Day 2. Patients had FIGO stage IB (n = 18), IA2 (n = 1), and IIA (n = 2). The median follow-up was 37 months (24-65 months). No significant acute gastrointestinal or genitourinary toxicity was experienced and no patients have experienced a bowel obstruction to date. CONCLUSIONS: The BBD may offer a means for positioning the mobile small intestine out of the radiation field and improving the tolerance of radiotherapy. The BBD provides a noninvasive technique for reduction of acute and chronic gastrointestinal morbidity.

The implementation of critical pathways in gynecologic oncology in a managed care setting: a cost analysis.

OBJECTIVES: The aim of the study is to determine whether critical pathways can be implemented at an academic institution to limit cost, without compromising patient satisfaction and quality of care. PATIENTS AND METHODS: Patients undergoing a hysterectomy with either cervical or endometrial cancer were placed on specific critical pathways consecutively for an 18-month study period. Preoperative teaching was intensified to educate the patient regarding expectations during the postoperative period. All patients were started on early feeding and patients were also placed on separate care pathways addressing pain and deep vein thrombosis prophylaxis. Total direct costs and patient satisfaction were obtained throughout the study period. During the year prior to care pathway implementation, patient data and direct costs were obtained for the preintervention group utilized for comparison. Postintervention groups were summarized every 6 months during the study period. RESULTS: From January 1997 through June 1998, 63 patients with cervical carcinoma undergoing a radical hysterectomy (DRG 353) and 21 patients with endometrial cancer who underwent a hysterectomy and lymph node sampling (DRG 355) were utilized as the preintervention group. During the 18-month study period (July 1998-December 1999), 42 patients (DRG 353) and 25 patients (DRG 355) were accrued. The average length of stay was reduced from 5.2 (DRG 353) and 4.7 days (DRG 355) prior to implementation of pathways to 3.4 days in both groups. In addition, total direct costs were reduced by 29 (DRG 353) and 32% (DRG 355) after implementation of care pathways. Patient satisfaction data recorded during the study did not demonstrate any change throughout the study period nor were there any higher rates of readmission after implementation of the care pathways. CONCLUSIONS: Critical pathways in gynecologic oncology can be implemented in a managed care environment in order to maintain high quality of care, maintain outcomes, and help reduce costs.

Accuracy of the pelvic examination in detecting adnexal masses.

OBJECTIVE: To estimate sensitivity, specificity, positive predictive value, Youden J statistic, and likelihood ratio of pelvic examination in adnexal assessment under ideal circumstances. METHODS: One hundred forty women consented to have pelvic examinations under general anesthesia before laparoscopy or laparotomy. They were assigned to examiners masked to indications for surgery, including attending gynecologists, gynecology residents, and medical students. Surgeons' findings were compared with examiners' findings. Variables assessed included adnexal diameter, presence of adnexal masses, and effect modifiers such as examiner experience and body mass index. RESULTS: Forty-nine left adnexal and 33 right adnexal masses were found during surgery. Examiners tended to underestimate adnexal size. Sensitivity of pelvic examinations for detecting left adnexal masses was 0.23-0.36 and for right adnexal masses was 0.15-0.28. Positive predictive value was low for left adnexal masses (0.50-0. 69) and right adnexal masses (0.26-0.39). Differences among examiner groups were not statistically significant. Patient obesity noticeably reduced detection of adnexal masses on either side. CONCLUSION: Bimanual pelvic examination has marked limitations for evaluating adnexa, even with ideal circumstances. Experience during postgraduate training in gynecology did not seem to improve examination accuracy. Patient characteristics such as obesity, uterine size, and abdominal scars limit the accurate palpation of the adnexa.

Hemorragia digestiva baja secundaria a tumor estromal yeyunal / Lower digestive hemorrhage secondary to a jejunal stromal tumor

Presentamos el caso de una mujer joven que comenzó con una hemorragia digestiva baja y que precisó intervención quirúrgica urgente ante la persistencia y gravedad de la misma. Fue diagnosticada por angiografía selectiva de arteria mesentérica superior de lesión yeyunal con sangrado activo tras haber resultado negativas otras pruebas diagnósticas. La intervención quirúrgica y la aplicación de pruebas inmunorreactivas establecieron el diagnóstico de tumor mesenquimal tipo estromal CD 34+. Revisamos las características de este tipo de tumores infrecuentes en esta localización (AU)

[Acute kidney failure secondary to inguinoscrotal bladder hernia]. / Fracaso renal agudo secundario a hernia vesical inguinoescrotal.

Bladder hernia is not a rare pathological condition, with a frequency between 0.3% and 3%, reaching the 10% between patients older than 50 years. Massive bladder hernia is less frequent and very rarely ureterohydronephrosis is associated with this pathology, given that the trigone is the only portion remaining fixed after herniation. Five cases have been described in the literature reviewed affecting ureters. The present paper represents the fourth case of bilateral ureterohydronephrosis in the literature. The treatment is surgical correction of the inguinoscrotal hernia.

Ectopic pregnancy causing hemothorax managed by thoracoscopy and actinomycin D.

BACKGROUND: Most patients with extratubal ectopic pregnancies present with vaginal bleeding and lower abdominal pain. We report a case of an extratubal ectopic pregnancy with extra-abdominal manifestations. CASE: An ectopic pregnancy implanted on the diaphragm resulted in spontaneous hemothorax due to trophoblastic invasion into the pleura. Thoracoscopic excision followed by actinomycin D chemotherapy provided successful resolution of the ectopic pregnancy. CONCLUSION: Abdominal pregnancies may have bizarre clinical presentations.

Management of twin pregnancies consisting of a complete hydatidiform mole and normal fetus.

OBJECTIVE: To report the clinical features, management, and outcome of twin pregnancies consisting of a complete hydatidiform mole and a coexisting normal fetus. METHODS: Between 1966 and 1997, seven women with complete hydatidiform mole and coexisting normal fetus were treated at the John I. Brewer Trophoblastic Disease Center of Northwestern University Medical School. Clinical features, including presenting symptoms, gestational dates, hCG levels, and complications, as well as route of delivery or evacuation, pregnancy outcome, genetic analysis, and need for chemotherapy were assessed. RESULTS: Four women required uterine evacuation before 20 weeks' gestation because of vaginal bleeding or medical complications, one woman required an emergency hysterotomy because of hemorrhage at 24 weeks, and two women delivered normal, viable infants at 26 and 34 weeks. The pathologic diagnosis of complete hydatidiform mole was confirmed in each case and the chromosome complement was 46,XX in all molar gestations. Four of seven women required chemotherapy for treatment of nonmetastatic gestational trophoblastic tumors, including both women who delivered viable infants and two of the five women whose pregnancies were evacuated before 24 weeks' gestation. All four patients were treated with five to seven cycles of a 5-day methotrexate regimen and achieved complete remission. CONCLUSION: Patients with a twin pregnancy consisting of a complete mole and a normal fetus are at increased risk for hemorrhage and medical complications, as well as the development of persistent gestational trophoblastic tumor.