A very low diffusion Fricke gel dosimeter with functionalised xylenol orange-PVA (XOPVA).

A gel dosimeter has been developed utilising a recently reported system for reducing Fe3+ diffusion in a Fricke gel dosimeter which chelates xylenol orange to the gelling agent poly(vinyl alcohol) (PVA). Formulations were investigated using both gelatin and PVA as the gelling agent, along with the inclusion of glyoxal. The resulting gel had an optical density dose response of 0.0031 Gy-1, an auto-oxidation rate of 0.000 23 h-1, and a diffusion rate of 0.132 mm2 h-1 which is a significant improvement over previously reported gelatin based Fricke gel dosimeters. The gel was also shown to be energy and dose-rate independent and could be reused after irradiation. Thus, this gel dosimeter has the potential to provide a safe and practical solution to three dimensional radiation dosimetry in the medical environment.

"But Dr Google said " - Training medical students how to communicate with E-patients.

Purpose: Patients who have access to information online may feel empowered and also confront their physicians with more detailed questions. Medical students are not well-prepared for dealing with so-called "e-patients." We created a teaching module to deal with this, and evaluate its effectiveness.Method: Senior medical students had to manage encounters with standardized patients (SPE) in a cross-over design. They received blended-learning teaching on e-patients and a control intervention according to their randomization group (EI/LI = early/late intervention). Each SPE was rated by two blinded video raters, the SP and the student.Results: N = 46 students could be included. After the intervention, each group (EI, LI) significantly improved their competency in dealing with e-patients as judged by expert video raters (EI: MT0 = 9.75 (2.51) versus MT1 = 16.60 (2.80); LI: MT0 = 8.70 (2.14) versus MT2 = 15.20 (2.84); both p < 0.001) and SP (EI: MT0 = 24.13 (4.83) versus MT1 = 26.52 (3.06); LI: MT0 = 23.37 (3.10) versus MT2 = 27.47 (4.38); both p < 0.001). Students' rating showed a similar non-significant trend.Conclusions: Students, SP and expert video raters determined that blended-learning teaching can improve students' competencies when dealing with e-patients. Within the study period, this effect was lasting; however, further studies should look at long-term outcomes.

Impact of tissue preservation on collagen fiber architecture.

Microarchitectural features of collagen-rich extracellular matrices provide the mechanical foundation for tissue function and exhibit topographical cues that influence cellular behavior including proliferation, migration and protein expression. Preservation of tissue microarchitecture is required for accurate evaluation of tissue characteristics and pathology. It is unclear whether common tissue preservation methods possess equal ability to preserve microarchitecture. We investigated collagen microarchitecture in samples that had been flash frozen, fixed in formalin or preserved in RNAlater®, and which contained both collagen-rich and collagen-sparse regions. Fibrillar collagen organization was characterized using picrosirius red staining and second harmonic generation (SHG) microscopy. Maintenance of collagen fiber characteristics compared to the gold standard of flash freezing depended on both the method of preservation and the local collagen content of the tissue. Both formalin fixation and RNAlater® preserved collagen fiber characteristics similar to flash freezing in collagen-rich areas of the tissue, but not in collagen-sparse regions. Analysis using picrosirius red staining indicated preservation-dependent changes in overall tissue architecture and suprafibrillar organization. Together with considerations of cost, ease of use, storage conditions and ability to use the preserved tissue for RNA or protein analysis, our quantitative characterization of the effects of preservation method on collagen microarchitecture may help investigators select the most appropriate preservation approach for their needs.

Technical Note: Preliminary investigations into the use of a functionalised polymer to reduce diffusion in Fricke gel dosimeters.

PURPOSE: A modification of the existing PVA-FX hydrogel has been made to investigate the use of a functionalised polymer in a Fricke gel dosimetry system to decrease Fe(3+) diffusion. METHODS: The chelating agent, xylenol orange, was chemically bonded to the gelling agent, polyvinyl alcohol (PVA) to create xylenol orange functionalised PVA (XO-PVA). A gel was created from the XO-PVA (20% w/v) with ferrous sulfate (0.4 mM) and sulfuric acid (50 mM). RESULTS: This resulted in an optical density dose sensitivity of 0.014 Gy(-1), an auto-oxidation rate of 0.0005 h(-1), and a diffusion rate of 0.129 mm(2) h(-1); an 8% reduction compared to the original PVA-FX gel, which in practical terms adds approximately 1 h to the time span between irradiation and accurate read-out. CONCLUSIONS: Because this initial method of chemically bonding xylenol orange to polyvinyl alcohol has inherently low conversion, the improvement on existing gel systems is minimal when compared to the drawbacks. More efficient methods of functionalising polyvinyl alcohol with xylenol orange must be developed for this system to gain clinical relevance.

The reproductive cycle of the Tasmanian devil (Sarcophilus harrisii) and factors associated with reproductive success in captivity.

Numbers of wild Tasmanian devils are declining as a result of the fatal, transmissible Devil Facial Tumor Disease. A captive insurance population program has been initiated but current captive breeding rates are sub-optimal and therefore the goal of this project was to increase our understanding of the estrous cycle of the devil and elucidate potential causes of failed male-female pairings. Temporal patterns of fecal progestagen and corticosterone metabolite concentrations were examined for females (n=41) in three categories of reproductive status (successful: viable young, n=20 estrous cycles; unsuccessful: paired with a male but no young confirmed, n=44 estrous cycles; non-mated: no access to a male during estrus, n=8 estrous cycles) but substantial differences were not found. Females were more likely to produce pouch young if pairing with the male extended into late proestrus (P<0.05), thereby decreasing the time between pairing and presumed ovulation. The interval between the end of proestrous elevation in progestagen metabolite concentrations and the beginning of the luteal phase was 7.6±2.3 days in successful females. The length of the luteal phase in successful females was 12.5±1.4 days which was not different from unsuccessful or non-mated females (P>0.05). Unsuccessful females had 1-3 estrous cycles within a single year. Successful females were predominantly wild-caught (17/19, 90%) and most produced young following the first estrous cycle of the season (18/20, 90%). Unsuccessful females were predominantly captive born (20/27, 74%) in this study. It is possible that a proportion of females that do not produce pouch young achieve conception but the timing of reproductive failure continues to be elusive in this species.

Survey of pharmacists and physicians on drug interactions between combined oral contraceptives and broad-spectrum antibiotics / Encuesta a farmacéuticos y médicos sobre interacciones entre contraceptivos orales combinados y antibióticos de amplio espectro

Objective: To evaluate physician and pharmacist knowledge on potential drug interactions between combined oral contraceptives (COC) and broad-spectrum antibiotics and determine if any difference exists between responses. Methods: Two hundred licensed retail pharmacists and 200 licensed family practice physicians in the states of Virginia, West Virginia, and Maryland were mailed an anonymous survey between August 2007 and November 2007. The survey consisted of 3 short questions asking practitioners about their current opinion on drug interactions with COCs and whether an alternative form of contraception is needed for patients taking COC and concomitant broad-spectrum antibiotics. The main outcome measure of the survey included: identifying how physicians and pharmacists handle prescribing or dispensing COCs along with broad-spectrum antibiotics. Gender, educational degree, and years in practice were also collected. Results: A total of 182 participants returned the surveys (57% were physicians and 43% were pharmacists). When asked if broad-spectrum antibiotics have a clinically significant interaction with COCs, 82.7% of physicians and 88.5% of pharmacists answered, «yes». Of the respondents, 84.6% stated that the drug interaction warrants the patient to be advised to use back-up contraception. A total of 90.1% stated that they currently instruct patients to use back-up contraception when prescribing or dispensing antibiotics to a patient who is on COC, with no statistically significant difference existing between the responses of the pharmacists and the physicians. Conclusion: Physicians and pharmacists believe that broad-spectrum antibiotics decrease the effectiveness of COCs. These practitioners warn their patients of this interaction and advise the use of back-up contraception. More education should be provided to practitioners regarding the data concerning COCs and broad spectrum antibiotics and lack of a proven interaction (AU)

Objetivo: Evaluar el conocimiento de médicos y farmacéuticos sobre posibles interacciones medicamentosas entre contraceptivos orales combinados (COC) y antibióticos de amplio espectro, y determinar si existe diferencia entre ambas respuestas. Métodos: Entre agosto 2007 y Noviembre 2007, se escribió para una encuesta anónima a 200 farmacéuticos comunitarios registrados y 200 médicos de familia registrados en los estados de Virginia, West Virginia y Maryland. La encuesta contenía 3 preguntas cortas sobre la opinión de los facultativos sobre las interacciones de COC y si se necesitaba una forma alternativa de contracepción en pacientes que tomaban COC y antibióticos de amplio espectro concomitantemente. Las principales variables de resultados incluían: identificar como médicos y farmacéuticos prescribían o dispensaban COC junto con antibióticos de amplio espectro. También se recogieron género, nivel educativo, y años de ejercicio. Resultados: Un total de 182 participantes devolvieron los cuestionarios (57% eran médicos y 43% farmacéuticos). Cuando se les preguntaba si los antibióticos de amplio espectro tienen alguna interacción clínicamente significativa con los COC, el 82,7% de los médicos y el 88,5% de los farmacéuticos respondieron «Sí». De los respondientes, el 84,6% afirmó que las interacciones merecen aconsejar a la paciente a que use otro método contraceptivo. Un total de 90,1% afirmó que actualmente instruían a las pacientes a usar el método alternativo cuando prescribían o dispensaban antibióticos a una paciente que estaba con COC, sin diferencias estadísticamente significativas entre las respuestas de médicos y farmacéuticos. Conclusión: Médicos y farmacéuticos creen que los antibióticos de amplio espectro reducen la efectividad de los COC. Estos facultativos advierten a sus pacientes de esta interacción y les aconsejan el uso de un método contraceptivo alternativo. Se debería proporcionar más formación a los facultativos sobre COC y antibióticos de amplio espectro y la falta de una interacción demostrada (AU)

A new method of energy prescription to improve weight loss.

Clinical outcome audit was carried out on two groups of obese out-patients for a 3-month follow-up period. In the first audit group of 35 patients (A1), energy intake was prescribed by diet history, whereas in the second audit group of 27 patients (A2) energy intake was prescribed from an estimate of individual energy requirements based on age, sex, and activity. There was no significant difference in age or initial BMI between the two groups and the failure-to-attend rate was the same in each group. Patients in Group A2 received a significantly higher energy prescription (P<0.001) than Group A1, but this was still significantly more restricted than the recommended 500 kcal energy deficit from energy expenditure (P<0.05). Weight loss was significant in both groups, but was greater in Group A2 than in Group A1. There was no significant correlation between weight loss and energy deficit. In a selected group of patients from Group A2 who were prescribed energy intake close to the recommended deficit of 500 kcal, weight loss was found to be significantly greater (P<0.05) when compared to the weight loss in Group A1. Results suggest that a diet prescription with an energy deficit below the estimated energy requirements does not lead to greater weight loss and probably reduces compliance. Estimating individual energy requirements rather than using dietary assessment may improve weight loss.

Summary of the practice parameter for the prevention and management of aggressive behavior in child and adolescent psychiatric institutions with special reference to seclusion and restraint.

This parameter reviews the current state of the prevention and management of child and adolescent aggressive behavior in psychiatric institutions, with particular reference to the indications and use of seclusion and restraint. It also presents guidelines that have been developed in response to professional, regulatory, and public concern about the use of restrictive interventions with aggressive patients with regard to personal safety and patient rights. The literature on the use of seclusion, physical restraint, mechanical restraint, and chemical restraint is reviewed, and procedures for carrying out each of these interventions are described. Clinical and regulatory agency perspectives on these interventions are presented. Effectiveness, indications, contraindications, complications, and adverse effects of seclusion and restraint procedures are addressed. Interventions are presented to provide more opportunities to promote patient independence and satisfaction with treatment while diminishing the necessity of using restrictive procedures.

Outcomes of posterolateral lumbar fusion in Utah patients receiving workers' compensation: a retrospective cohort study.

STUDY DESIGN: A retrospective cohort study consisting of a medical record review and a follow-up telephone survey of patients with lumbar fusion, at least 2 years after their surgery, was performed. OBJECTIVE: To identify presurgical correlates and long-term outcomes from posterolateral lumbar fusion in Utah patients receiving workers' compensation. SUMMARY OF BACKGROUND DATA: Lumbar fusion has been criticized for its highly variable outcomes, and compensated workers are at particular risk for poor outcomes. Evidence suggests that presurgical psychosocial factors may be important modifiers of back pain reporting and back surgery outcomes. METHODS: The patients in this study were 185 compensated workers in Utah who underwent posterolateral lumbar fusion. Patient medical records were independently reviewed, and medical and sociodemographic variables were coded. A telephone outcome survey was completed with 130 patients (70%) an average of 4.6 years after their surgery. RESULTS: Reported solid fusion, reoperation, and disability rates for the follow-up sample were 74%, 24%, and 25%, respectively. As reported by the patients, 41% experienced no change or a worsened quality of life. Mean scores from the Roland and Morris Back Pain Disability Questionnaire, the Stauffer-Coventry-Index, and the Short-Form 20 Multidimensional Health Survey indicate that many patients experienced postsurgical dysfunction. Presurgical predictors of outcomes were number of prior low back operations, income at time of injury, age, litigation, and depression. CONCLUSIONS: Outcomes of posterolateral lumbar fusion among compensated workers in Utah are inconsistent. Outcomes can be predicted by presurgical sociodemographic variables. Screening for such presurgical risk factors may be important for prudent surgical decisions and rehabilitation planning.

Continuous-wave 4.3-mum intracavity difference frequency generation in an optical parametric oscillator.

We have achieved 150 mW of cw output at 4.3mum, using difference frequency mixing in a singly resonant optical parametric oscillator (OPO). We pumped the OPO cavity, which contains periodically poled LiNbO(3) (PPLN), with a 14-W 1.06-mum Nd:YAG laser to generate a signal at 1.7 mum and an idler at 2.8 mum. Mixing of the two waves at the same crystal temperature and grating spacing yielded emission in the mid IR. This technique avoids the mid-IR absorption-high-threshold problem, which has limited the cw performance of PPLN OPO's at wavelengths beyond 4 mum. Provided that tunability is not required, this method is a simple alternative to multiple-crystal configurations.

Surgical treatment of uterine atony employing the B-Lynch technique.

Postpartum hemorrhage remains a major cause of maternal morbidity and mortality. Four cases utilizing the B-Lynch technique for control of hemorrhage secondary to uterine atony are presented. The B-Lynch technique appears to be effective in controlling postpartum hemorrhage. More experience is needed before the B-Lynch technique can be accepted as routine practice.

Does pediatric orthopedic subspecialization affect hospital utilization and charges?

In the current climate of health care reform, there is a perception that overspecialization is responsible for increased medical costs. Few studies support the premise that high-quality surgical subspecialization improves the cost effectiveness of care. The purpose of this study was to compare hospital utilization and charges between a pediatric hospital staffed by pediatric orthopedic subspecialists and a community hospital system for the care of closed femur fractures and slipped capital femoral epiphysis (SCFE) in a pediatric population. We reviewed hospital charges and length-of-stay (LOS) data for all children treated for closed femoral shaft fractures and SCFE between 1992 and 1994 within the Intermountain Health Care System (IHC). Within the IHC, there are 23 community hospitals and one children's hospital (PCMC). Patients were matched for age and injury severity. Four of six orthopedic surgeons at PCMC are pediatric orthopedists, but none of the community orthopedists has subspecialty training in pediatric orthopedics. For closed femoral shaft fractures (n = 334), the average hospital charges were less (PCMC, $4,943/Other IHC, $9,031), and length of stay was shorter (PCMC, 2.81 days/Other IHC, 8.91 days) when the child was treated at the children's hospital by pediatric orthopedic subspecialists. For SCFE (n = 63), the average hospital charges were less (PCMC, $2,824/Other IHC, $3,544) and the length of stay was shorter (PCMC, 1.13 days/Other IHC, 1.64 days) at the children's hospital. These data suggest that hospital utilization and charges were significantly decreased if the care was provided by pediatric orthopedic subspecialists in a children's hospital.

A comparison of manual versus computer-assisted radiographic measurement. Intraobserver measurement variability for Cobb angles.

STUDY DESIGN: A comparison between computer-assisted measurement using digitized radiographs, which has the potential to reduce error, and manual measurement using standard radiographs. OBJECTIVE: To assess measurement variability for the Cobb method on digital radiographs and compare it with that of manual measurements on standard radiographs. BACKGROUND DATA: Studies of the Cobb method have demonstrated multiple sources of error leading to significant intraobserver measurement variability. Estimates for the 95% confidence interval for intraobserver variability range from 2.8 degrees to 10 degrees. METHODS: Twenty-four scoliosis radiographs were measured by six examiners. Two measurement sets were done manually ("manual set"), and two measurement sets were done on digitized images using a computer mouse ("computer set"). RESULTS: For the manual set, the 95% confidence interval for intraobserver variability was 3.3 degrees (range, 2.5-4.5 degrees). For the computer set, the value was 2.6 degrees (range, 2.3-3.3 degrees). This difference in 95% confidence intervals between the manual and computer sets was statistically significant (P < 0.001). CONCLUSIONS: The results of this study demonstrate that intraobserver variability for manual and computer Cobb angle measurements yield a 95% confidence interval of approximately 3 degrees, with the computer having a slightly lower variability. The computer technique removes sources of intrinsic error, e.g., the variability introduced by using different manual protractors, the inaccuracy of standard protractors, and the use of wide-diameter radiographic markers. Identical digital images can be shared electronically between centers, without having to duplicate and mail films. Multicenter studies in which different examiners will be measuring Cobb angles may consider using the computer as a measuring device to reduce intrinsic measurement errors.