Experimental investigation of the implementation of Fermi-Eyges-Hogstrom electron beam model of the Pinnacle3 system at extended SSDs.

A commercially available ADAC Pinnacle(3) radiation treatment planning system has been used to model electron beams from a Varian Clinac 2300C/D in the energy range of 6 to 22 MeV. Prior to clinical use, the dosimetric characteristics of the beams have to be modeled accurately. As a first step for beam modeling, a number of dose profile and depth dose measurements were taken at standard source-to-surface distance (SSD) of 100 cm. Dose profiles and depth dose measurements at extended SSDs up to 120 cm are important for ascertaining accuracy of the model, as well as their clinical usefulness in the treatment of some sites (e.g., head-and-neck tumors). Modeled and measured beam data were compared. Over 98% of comparison points (modeled vs. measured) at 100-cm SSD were within 2.5% or 2.5 mm. At 110 cm SSD, over 98% of compared points were within 4% or 4 mm, and at 120-cm SSD, over 98% of compared points were within 5% or 5 mm. Overall, more than 98% of compared points were within 4% or 4 mm. Better models were produced for lower energies (6 to 15 MeV) than higher energies (18 and 22 MeV). For 6, 9, 12, and 15 MeV, 89% of compared points were within 2% or 2 mm. For 18- and 22-MeV electron energies, 75% and 67%, respectively, were within 2% or 2 mm. These results are consistent with the recommendations of AAPM Task Group Report 53.     

Closed Transverse Pinning for Reduction and Fixation of Metatarsal Neck Fractures: Surgical Technique

Most metatarsal neck fractures can be successfully treated non-operatively in a cast boot. Displaced metatarsal neck fractures tend to be less stable and have a propensity for the distal fragment to angulate, secondary to the strong flexor tendons, which often forces the distal fracture fragment in a plantar direction and leads to relative metatarsal shortening. Most literature is focussed on antegrade fixation of metatarsal neck fractures using pre-bent K wires or thin elastic nails. Apart from the technical challenges, this technique is limited when bones are osteoporotic as the pre-bent distal end of the K-wire may penetrate the plantar cortex of the proximal metatarsal and prevent the wire from entering the medullary canal of the metatarsal and advancing to the fracture site. Furthermore, when the medullary canal is narrow especially in Asian patients, it may be difficult to pass a bent K-wire through the isthmus of the metatarsal shaft. We describe an innovative technique of closed transverse wiring of the metatarsal head necks that has a distinct advantage in Asian population with osteoporotic bones. With percutaneous manipulation using digital pressure, closed reduction of fracture fragments of the most displaced fracture is done under fluoroscopic guidance to achieve a satisfactory alignment followed by closed transverse wiring of the metatarsal heads. With this procedure, adjacent fractures remain stable within an acceptable range because of intermetatarsal ligaments connected to the adjacent intact head. Our technique has a relatively short operating time and allows for early motion of the metatarso-phalangeal joint. This is especially useful for those with osteoporosis, narrow canal, soft tissue compromise, intra-operative failure of ante-grade pinning and in scenarios of limited surgical equipment/expertise.     

Autistic Traits,Empathizing–Systemizing,and Gender Diversity

Archives of Sexual Behavior - Previous research indicates a link between autism and transgender and gender-diverse identities, though the association is not yet fully understood. The current study...     

Reducing unnecessary crossmatching for hip fracture patients by accounting for preoperative hemoglobin concentration

BACKGROUNDMaximum surgical blood order schedules were designed to eliminate unnecessary preoperative crossmatching prior to surgery in order to conserve blood bank resources. Most protocols recommend type and cross of 2 red blood cell (RBC) units for patients undergoing surgery for treatment of hip fracture. Preoperative hemoglobin has been identified as the strongest predictor of inpatient transfusion, but current maximum surgical blood order schedules do not consider preoperative hemoglobin values to determine the number of RBC units to prepare prior to surgery. AIMTo determine the preoperative hemoglobin level resulting in the optimal 2:1 crossmatch-to-transfusion (C:T) ratio in hip fracture surgery patients.METHODSIn 2015 a patient blood management (PBM) program was implemented at our institution mandating a single unit-per-occurrence transfusion policy and a restrictive transfusion threshold of < 7 g/dL hemoglobin in asymptomatic patients and < 8 g/dL in those with refractory symptomatic anemia or history of coronary artery disease. We identified all hip fracture patients between 2013 and 2017 and compared the preoperative hemoglobin which would predict a 2:1 C:T ratio in the pre PBM and post PBM cohorts. Prediction profiling and sensitivity analysis were performed with statistical significance set at P < 0.05. RESULTSFour hundred and ninety-eight patients who underwent hip fracture surgery between 2013 and 2017 were identified, 291 in the post PBM cohort. Transfusion requirements in the post PBM cohort were lower (51% vs 33%, P < 0.0001) than in the pre PBM cohort. The mean RBC units transfused per patient was 1.15 in the pre PBM cohort, compared to 0.66 in the post PBM cohort (P < 0.001). The 2:1 C:T ratio (inpatient transfusion probability of 50%) was predicted by a preoperative hemoglobin of 12.3 g/dL [area under the curve (AUC) 0.78 (95% confidence interval (CI), 0.72-0.83), Sensitivity 0.66] in the pre PBM cohort and 10.7 g/dL [AUC 0.78 (95%CI, 0.73-0.83), Sensitivity 0.88] in the post PBM cohort. A 50% probability of requiring > 1 RBC unit was predicted by 11.2g/dL [AUC 0.80 (95%CI, 0.74-0.85), Sensitivity 0.87] in the pre PBM cohort and 8.7g/dL [AUC 0.78 (95%CI, 0.73-0.83), Sensitivity 0.84] in the post-PBM cohort.CONCLUSIONThe hip fracture maximum surgical blood order schedule should consider preoperative hemoglobin in determining the number of units to type and cross prior to surgery.     

Effects of Acute and Chronic Inflammation on the Pharmacokinetics of Prednisolone in Rats

The effects of acute and chronic stages of carrageenan-induced air-pouch inflammation on the pharmacokinetics of prednisolone were studied in male Wistar rats. Chronic inflammation produced a significant increase in the area under the curve (AUC) of prednisolone compared to control animals (6594 ± 2144 vs 3530 ± 2164 µg · hr/ L). The effect of acute inflammation was not significant (AUC = 4996 ± 3813). Both acute and chronic inflammation also reduced thein vitro plasma protein binding of prednisolone, the reduction being much greater after chronic inflammation. The AUC of free prednisolone after chronic inflammation was 3141 µg · hr/L, compared to 1121 µg · hr/L in the control group and 1823 µg · hr/L after acute inflammation. The mean values of half-life and apparent volume of distribution at steady-state in each group were similar. These results indicate that prednisolone must be used with caution in the treatment of inflammatory diseases because of higher free concentrations of the steroid.     

Right‐Sided Endomyocardial Fibrosis with a Right Atrial Thrombus: Three‐Dimensional Transthoracic Echocardiographic Evaluation

Endomyocardial fibrosis is a form of restrictive cardiomyopathy mainly affecting poor children and young adults in geographically restricted areas of Latin America, Africa, and Southeast Asia. The pathophysiological hallmark of the disease is focal or diffuse endocardial thickening involving mainly the inflow, the apices, and the subvalvular region leading to valvular regurgitation, diastolic dysfunction and obliteration of the ventricular apex. Advanced right‐sided disease has slow flow of blood through chambers with propensity of thrombus formation especially in the right atria. Although two‐dimensional transthoracic echocardiography remains the cornerstone for the diagnosis of this disease, the case presented here shows how three‐dimensional transthoracic echocardiography can add substantial information regarding the region of involvement of the right ventricle as well as the various characteristics of the right atrial thrombus.