Monte Carlo calculation of the sensitivity of a commercial dose calibrator to gamma and beta radiation

The detection process used in a commercial dose calibrator was modeled using the GEANT 3 Monte Carlo code. Dose calibrator efficiency for gamma and beta emitters, and the response to monoenergetic photons and electrons was calculated. The model shows that beta emitters below 2.5 MeV deposit energy indirectly in the detector through bremsstrahlung produced in the chamber wall or in the source itself. Higher energy beta emitters (E > 2.5 MeV) deposit energy directly in the chamber sensitive volume, and dose calibrator sensitivity increases abruptly for these radionuclides. The Monte Carlo calculations were compared with gamma and beta emitter measurements. The calculations show that the variation in dose calibrator efficiency with measuring conditions (source volume, container diameter, container wall thickness and material, position of the source within the calibrator) is relatively small and can be considered insignificant for routine measurement applications. However, dose calibrator efficiency depends strongly on the inner-wall thickness of the detector.     

Gamification for Family Engagement in Lifestyle Interventions: A Systematic Review

Prevention Science - The majority of chronic conditions that plague the USA are modifiable by lifestyle change. Lifestyle interventions that incorporate family members for social support and that...     

Performance of a Rapid Self-Test for Detection of Trichomonas vaginalis in South Africa and Brazil

Women participating in studies in Brazil (n = 695) and South Africa (n = 230) performed rapid point-of-care tests for Trichomonas vaginalis on self-collected vaginal swabs. Using PCR as the gold standard, rapid self-testing achieved high specificity (99.1%; 95% confidence interval [CI], 98.2 to 99.6%) and moderate sensitivity (76.7%; 95% CI, 61.4 to 88.2%). These tests may be considered an alternative to syndromic management in resource-poor settings.     

Therapeutic plasma exchange in the management of sepsis and multiple organ dysfunction syndrome: A report of three cases

Sepsis with multi organ dysfunction syndrome (MODS) is the most common cause of death in patients in noncoronary intensive care units. Currently, there are no specific treatments that reduce mortality in patients with sepsis and MODS. We report three patients who received therapeutic plasma exchange (TPE) for sepsis with MODS who completely recovered. The first patient, a 3‐year‐old male presented with Methicillin‐resistant Staphylococcus aureus‐associated respiratory, renal, coagulation, hepatic, and neurologic dysfunction. After 5 TPEs, the patient fully recovered. The second patient was a 36‐year‐old pregnant female who developed MODS at 22 weeks of gestation. She had developed respiratory, hepatic, renal, cardiovascular, neurologic, and coagulation dysfunction following pneumonia and concurrent urinary tract infection resulting in an intrauterine fetal demise. After 8 TPEs, the patient was discharged home with only mild residual hepatic dysfunction. The third patient, a 50‐year‐old female with a history of seizure disorder, was found unresponsive in over 100°F heat and diagnosed with Staphylococcus aureus‐associated MODS. Her respiratory, coagulation, neurologic, renal, and hepatic systems were affected. The patient underwent 6 TPEs after which she had marked improvement. In conclusion, TPE may be an effective adjunct therapy in MODS by possibly removing toxic mediators and replacing deficient factors using donor plasma. J. Clin. Apheresis 29:127–131, 2014. © 2013 Wiley Periodicals, Inc.     

The Constipation Severity Instrument: A Validated Measure

Purpose This study was designed to develop and test the validity and reliability of the Constipation Severity Instrument. Methods Scale development was conducted in two stages: 1) 74 items were generated through a literature review and focus groups of constipated patients and medical providers; and 2) a preliminary instrument was administered to 191 constipated patients and 103 healthy volunteers. Test-retest reliability of the constipated group was assessed (N = 90). Content, convergent, divergent, and discriminant validity were evaluated by using other validated measures by performing one-way analysis of variance and Pearson correlations. Results Exploratory and confirmatory factor analysis revealed three subscales: obstructive defecation, colonic inertia, and pain. Internal consistency (α = 0.88–0.91) and test-retest reliability (intraclass correlation coefficients = 0.84–0.91) were high for all subscales. Constipated patients were grouped by Rome II criteria: functional constipation (22 percent), pelvic floor dyssynergia (15 percent), constipation predominant irritable bowel syndrome (23 percent), and no specific criteria (40 percent). Those with constipation predominant irritable bowel syndrome or pelvic floor dyssynergia scored higher on the Obstructive Defecation and Colonic Inertia subscales than those with functional constipation or no specific criteria (P = 0.001–0.058). Subjects with functional constipation had much lower scores on the pain subscale than constipation predominant irritable bowel syndrome, functional constipation, or no specific criteria (P < 0.009).The Constipation Severity Instrument subscale and total score correlated very highly with the subscales and total score of the Patient Assessment of Constipation Symptom measure. The Constipation Severity Instrument subscales discriminated well between constipated patients and healthy volunteers (P < 0.001) and demonstrated excellent divergent validity. Higher Constipation Severity Instrument scores inversely correlated with general quality of life. Conclusions The Constipation Severity Instrument is a reliable and valid instrument for assessing constipated patients. Administration of the Constipation Severity Instrument to other constipated patients will further validate its use. Supported by the University of California San Francisco Hellman Family Award for Early Career Faculty. Read at the meeting of The American Society of Colon and Rectal Surgeons, St. Louis, Missouri, June 2 to 6, 2007. Reprints are not available.