In this work, the dosimetric characteristics of a new commercial carbon fiber treatment table are investigated. The photon beam attenuation properties of the Siemens image-guided radiation therapy (IGRT) tabletop were studied in detail. Two sets of dosimetric measurements were performed. In the first experiment a polystyrene slab phantom was used: the central axis attenuation and the skin-sparing detriment were investigated. In the second experiment, the off-axis treatment table transmission was investigated using a polystyrene cylindrical phantom. Measurements were taken at the isocenter for a 360° rotation of the radiation beam. Our results show that the photon beam attenuation of the Siemens IGRT carbon fiber tabletop varies from a minimum of 2.1% (central axis) to a maximum of 4.6% (120° and 240° beam incidence). The beam entrance dose increases from 82% to 97% of the dose at the depth of maximum for a clinical 6-MV radiation field. The depth of maximum also decreases by 0.4 cm. Despite the wedge cross section of the table the beam attenuation properties of the IGRT tabletop remain constant along the longitudinal direction. American Association of Medical Dosimetrists. 相似文献
The objective of this prospective, randomized, double-blind study was to determine if preoperative administration of a femoral nerve block reduces the amount of morphine needed for postoperative analgesia after total knee arthroplasty (TKA). Forty-two patients undergoing TKA were randomly assigned to receive either a femoral nerve block (0.50% bupivacaine hydrochloride with epinephrine 1:200,000) or matching placebo. Results showed postoperative morphine use was significantly lower in patients who received the nerve block (25.5 vs 37.5 mg, P = .016); however, the 2 groups had similar pain scores and rehabilitative outcomes. In general, a preoperative femoral nerve block is a safe and effective adjunct for decreasing morphine use for post-TKA analgesia. 相似文献
To date, few studies have examined the personality characteristics and clinical predictors of impulsive behaviors in eating disorders (ED). The aim of this work was to study the prevalence of a wide range of impulsive behaviors in a sample of 554 ED subjects and to examine the predictors of these behaviors. Subjects were diagnosed according to DSM-IV criteria as having anorexia nervosa restricting type (ANR; n = 183), anorexia nervosa binge eating/purging type (ANBP; n = 65), bulimia nervosa purging type (BNP; n = 244), and bulimia nervosa nonpurging type (BNNP; n = 62). Nine different types of impulsive behaviors were assessed in these groups. About 55% of the whole sample reported at least one type of impulsive behavior, 35% more than one, and about 13% more than three. According to findings, impulsive and multi-impulsive subjects are characterized by the presence of purging behavior and by specific temperamental features such as high levels of novelty seeking and low persistence. The prediction of impulsive behavior is further improved by considering the presence of a history of childhood abuse, maternal psychiatric morbidity, and some specific psychological symptoms such as maturity fears, perfectionism, depression, and obsessive-compulsive symptoms. The presence of impulsive behavior appears to be associated with overall higher levels of psychiatric symptomatology and eating psychopathology, thus indicating that they are an important feature to be considered in the assessment and treatment of ED. 相似文献
Video-assisted minimally invasive cardiac surgery (VAMICS) is currently performed with various indications. However, despite the increasing evidence of its effectiveness, new approaches have to be defined to simplify this procedure, minimize its potential complications and limit its costs, for a wider use in the surgical community. The limited access to the aorta is a key point in VAMICS and mandates specific clamping modalities with their own limitations, costs and drawbacks. The Portaclamp (Cardio Life Research SA, Louvain la Neuve, Belgium), a new autoguided extravascular aortic cross-clamping system, has been recently proposed to facilitate VAMICS. Herein, we describe the Portaclamp approach and report our indications and preliminary clinical experience so to define its role in VAMICS. 相似文献
Over 800 Maine residents will be diagnosed with colorectal cancer (CRC) this year, and nearly 300 will die from the disease.
While CRC screening can reduce these rates, it is only among insured populations that screening rates exceed 50%. This project
aimed to reduce barriers to, and increase rates of CRC screening among underinsured and uninsured women, ages 50 years and
over, residing in Cumberland County, Maine. The existing network of the Maine Breast and Cervical Health Program (MBCHP) was
used to reach the target population. A packet containing (1) an offer for no-cost fecal occult blood test (FOBT) screening
and CRC-related educational materials, and (2) a stamped, addressed postcard specifying the woman’s interest in these resources,
was mailed to 300 MBCHP enrollees residing in Cumberland County. Women requesting screening were contacted by phone to further
determine eligibility. Ninety-three women (31%) requested FOBT kits and 29 of these women requested educational materials.
Ten women were ineligible for screening because of previous colonoscopy. Fifty-two completed FOBT kits (63%) were returned;
all were negative. An additional 42 (14%) women requested educational materials only. To reduce the burden of CRC in Maine
and nationally, disparate populations must be reached with efficient and effective screening services. Established networks
are proven means for reaching uninsured and underinsured individuals with education, screening services, and necessary follow-up
care. This project serves as a model for the future development of similar programs statewide and nationally. 相似文献
During femorodistal bypass angioscopy can be used in vein graft preparation allowing valve lysis and the identification of tributaries under direct vision. A total of 30 patients have undergone angioscopic assisted femorodistal bypass using either an Olympus or Stortz system. Nineteen patients have undergone full vein mobilisation and valve lysis under direct vision. Eleven patients had in situ bypass with ligation of tributaries, identified by the angioscope, through small stab incisions. No evidence of fistula or retained valve cusps was found by subsequent duplex scanning and arteriography. One of these grafts failed at 6 days due to an unrecognised outflow stenosis. The mean hospital stay after operation for this latter group of patients was 5.2 days (range 4.4-6.0 days) compared with 9.5 days (8.6-10.3 days) in a historical group of 30 patients (P < 0.001). Angioscopy is a useful aid in the performance of femorodistal bypass. Early experience suggests that hospital stay may be reduced by angioscope assisted in situ femorodistal bypass because of the minimal dissection involved. 相似文献
Background: Patients may require perioperative cooling for a variety of reasons including treatment of a malignant hyperthermia crisis and induction of therapeutic hypothermia for neurosurgery. The authors compared heat transfer and core cooling rates with five cooling methods.
Methods: Six healthy volunteers were anesthetized with desflurane and nitrous oxide. The cooling methods were 1) circulating water (5 [degree sign] Celsius, full-length mattress and cover), 2) forced air (10 [degree sign] Celsius, full-length cover), 3) gastric lavage (500 ml iced water every 10 min), 4) bladder lavage (300 ml iced Ringer's solution every 10 min), and 5) ice-water immersion. Each method was applied for 40 min or until the volunteers' core temperatures approached 34 [degree sign] Celsius. The volunteers were rewarmed to normothermia between treatments. Core cooling rates were evaluated using linear regression.
Results: The first volunteer developed abdominal cramping and diarrhea after gastric lavage. Consequently, the technique was not again attempted. Bladder lavage increased heat loss 10 [nearly =] 10 W and decreased core temperature 0.8 +/- 0.3 [degree sign] Celsius/h (r2 = 0.99 +/- 0.002; means +/- SD). Forced-air and circulating-water cooling comparably increased heat flux, [nearly =] 170 W. Consequently, core cooling rates were similar during the two treatments at 1.7 +/- 0.5 [degree sign] Celsius/h (r2 = 0.99 +/- 0.001) and 1.6 +/- 1.1 [degree sign] Celsius/h (r2 = 0.98 +/- 0.02), respectively. Immersion in an ice water slurry increased heat loss [nearly =] 600-800 W and decreased core temperature 9.7 +/- 4.4 [degree sign] Celsius/h (r sup 2 = 0.98 +/- 0.01). Immersion cooling was associated with an afterdrop of [nearly =] 2 [degree sign] Celsius. 相似文献
OBJECTIVES: We aimed to investigate both nocturnal spontaneous and morning growth hormone (GH)-releasing hormone (GHRH)-induced GH secretion in children on daily glucocorticoid treatment after liver transplantation and to evaluate the effect of pyridostigmine (an acetylcholinesterase inhibitor thought to reduce hypothalamic somatostatin tone) on GH secretion in these patients. DESIGN: We performed a randomized, single-blind, cross-over study. PATIENTS: We studied three male and three female juvenile patients, within a year of orthotopic liver transplantation and under immunosuppressive glucocorticoid therapy (mean dose +/- SEM, 5.92 +/- 0.63 mg/day) and five normal children (four males, one female). MEASUREMENTS: Both nocturnal spontaneous and morning GHRH-induced GH secretion were evaluated after administration of placebo, 1 tablet p.o., or pyridostigmine, 2 mg/kg p.o. RESULTS: Spontaneous GH. Placebo: in liver transplanted children nocturnal GH secretion (mean GH level 10.8 +/- 2.0 mU/l) was not significantly different with respect to normal children (mean GH level 12.8 +/- 1.2 mU/l); pyridostigmine: nocturnal GH secretion was significantly increased as compared to placebo in subjects with liver transplantation but not in normal children. GHRH test. Placebo: liver transplanted patients showed a blunted GH response to GHRH with respect to normal children; pyridostigmine: the GH responses to GHRH (P less than 0.05) increased as compared to placebo and did not differ significantly in the two groups. CONCLUSIONS: Our data suggest a steroid-mediated increase in hypothalamic somatostatin tone in liver transplanted children. 相似文献