Antibiotic treatment failure of uncomplicated urinary tract infections in primary care.

BACKGROUND: Higher resistance rates of > 20% have been noted in Enterobacteriaceae urinary isolates towards ciprofloxacin and co-trimoxazole (C + C) in Singapore, compared with amoxicillin-clavulanate and nitrofurantoin (AC + N). This study examined if treatment failure varied between different antibiotics, given different resistant rates, for uncomplicated urinary tract infections (UTIs) managed in primary care. We also aimed to identify gaps for improvement in diagnosis, investigations, and management. METHODS: A retrospective cohort study was conducted from 2019 to 2021 on female patients aged 18-50 with uncomplicated UTIs at 6 primary care clinics in Singapore. ORENUC classification was used to exclude complicated UTIs. Patients with uncomplicated UTIs empirically treated with amoxicillin-clavulanate, nitrofurantoin, ciprofloxacin or co-trimoxazole were followed-up for 28 days. Treatment failure was defined as re-attendance for symptoms and antibiotic re-prescription, or hospitalisation for UTI complications. After 2:1 propensity score matching in each group, modified Poisson regression and Cox proportional hazard regression accounting for matched data were used to determine risk and time to treatment failure. RESULTS: 3194 of 4253 (75.1%) UTIs seen were uncomplicated, of which only 26% were diagnosed clinically. Urine cultures were conducted for 1094 (34.3%) uncomplicated UTIs, of which only 410 (37.5%) had bacterial growth. The most common organism found to cause uncomplicated UTIs was Escherichia coli (64.6%), with 92.6% and 99.4% of isolates sensitive to amoxicillin-clavulanate and nitrofurantoin respectively. Treatment failure occurred in 146 patients (4.57%). Among 1894 patients treated with AC + N matched to 947 patients treated with C + C, patients treated with C + C were 50% more likely to fail treatment (RR 1.49, 95% CI 1.10-2.01), with significantly higher risk of experiencing shorter time to failure (HR 1.61, 95% CI 1.12-2.33), compared to patients treated with AC + N. CONCLUSION: Treatment failure rate was lower for antibiotics with lower reported resistance rates (AC + N). We recommend treating uncomplicated UTIs in Singapore with amoxicillin-clavulanate or nitrofurantoin, based on current local antibiograms. Diagnosis, investigations and management of UTIs remained sub-optimal. Future studies should be based on updating antibiograms, highlighting its importance in guideline development.

Arthroscopic Distal Triceps Repair.

In this note, we describe an arthroscopic repair of a degenerative tear of the triceps using a suture weave and an anatomic footprint anchor. We are able to assess, debride, and anatomically repair the distal triceps to its insertion. Compared with open procedures, this arthroscopic repair offers lower morbidity, faster recovery, and improved cosmesis. Our goal was to improve the function and strength of the elbow through this arthroscopic surgical fixation.

Variability of gross tumor volume delineation in head-and-neck cancer using PET/CT fusion, Part II: the impact of a contouring protocol.

The purpose of this study was to assess the efficacy of a gross tumor volume (GTV) contouring protocol on interobserver variability between 4 physicians in positron emission therapy/computed tomography (PET/CT) treatment planning of head-and-neck cancer. A GTV contouring protocol for PET/CT treatment planning was developed utilizing 4 stages: Preliminary contouring on CT alone, determination of appropriate PET windowing, accurate image registration, and modification of CT contouring with correctly formatted PET/CT display and rules for modality disagreement. Two neuroradiologists and 2 radiation oncologists (designated as A, B, C, and D, respectively) were given a tutorial of PET/CT coregistered imaging individualized to their skill level, which included a step-by-step explanation of the protocol with clinical examples. Opportunities for questions and hands-on practice were given. The physicians were asked to re-contour 16 head-and-neck patients from Part I on PET/CT fusion imaging. Differences in volume magnitude were analyzed for statistical significance by analysis of variance (ANOVA) and paired t-tests (alpha<0.05). Volume overlap was analyzed for statistical significance using Wilcoxon signed-rank tests (alpha<0.05). Volume overlap increased significantly from Part I to Part II (p<0.05). One previously significant difference between physicians disappeared with the protocol in place. The mean fusion volume of Physician C, however, remained significantly larger than that of Physician D (p<0.01). This result is unchanged from Part I. The multidisciplinary contouring protocol significantly improved the coincidence of GTVs contoured by multiple physicians. The magnitudes of the volumes showed marginal improvement in consistency. Developing an institutional contouring protocol for PET/CT treatment planning is highly recommended to reduce interobserver variability.

Preliminary results of radiation therapy for prostate cancer in human immunodeficiency virus-positive patients.

OBJECTIVES: The purpose of this study was to report on the clinical outcomes of patients treated at our institution for prostate cancer (PCa) who had been previously diagnosed as Human immunodeficiency virus (HIV) positive. METHODS: The authors conducted a retrospective study of 14 PCa/HIV patients who were being treated for PCa with external beam radiotherapy, brachytherapy, or a combination of the two. Each patient's prostate-specific antigen (PSA) level, CD4 count, and viral load were obtained before the initial radiation treatment and at the time of their most recent follow-up. In addition, 13 of 14 patients completed a quality of life survey with a social worker on staff and were examined by their radiation oncologist to assess the complications after treatment. RESULTS: Comparing pretreatment data with the data at last follow-up, only 1 patient's PSA level remained above 1.1 ng/mL. The average CD4 count remained stable, increasing from 523 to 577 cells/mm(3), with the lowest final count at 200 cells/mm(3). Viral load increased in only 2 of 14 patients. There were no unusual rectal, urinary, or sexual complications, and no infections related to treatment. CONCLUSIONS: Based on changes in viral load and CD4 count, radiotherapy does not appear to have a long-term negative effect on the immune system. Treatment complications are consistent with HIV-negative patients, giving no evidence that the subset of PCa/HIV patients should be treated differently from PCa patients without HIV when considering radiation therapy. More investigation will be necessary before reliable mortality and morbidity data can be assessed.

Evaluating eye injury risk of Airsoft pellet guns by parametric risk functions.

Over 2.4 million eye injuries occur each year in the United States as a result of trauma. New toy guns, commonly referred to as Airsoft guns are increasingly becoming responsible for ocular injuries in children. The purpose of this study was to determine the ocular injury risk of these Airsoft guns by experimental testing and the use of previously generated ocular injury risk functions. A total of 26 Airsoft pellet impact tests were performed on both post-mortem human and porcine eyes in a laboratory environment. Projectile parameters of diameter, mass, and velocity were used to calculate the injury potential of these impacts for five different ocular injuries: corneal abrasion, lens dislocation, hyphema, retinal damage, and globe rupture. Globe rupture was not observed in any of the experimental tests, which is consistent with that reported in the literature. The two most likely ocular injuries caused by these Airsoft guns are corneal abrasion and hyphema, at nearly a 100% and a greater than 75% risk of injury, respectively. This is consistent with the types of injuries reported in the literature, with corneal abrasion and hyphema being the most frequently occurring ocular injuries due to Airsoft guns. More experimental data on retinal injuries is necessary to make an accurate assessment of the risk of retinal damage from blunt impacts. In summary, the potential for ocular injury from Airsoft guns is great and protective equipment such as protective eyewear should be considered mandatory during operation.

The effect of gender and body size on linear accelerations of the head observed during daily activities.

The purpose of this study was to determine the effect of gender and body size on peak linear head accelerations during daily activities. Head accelerations were measured for 18 volunteers using a biteplate system. Each subject performed seven activities: sitting in a chair, sitting quickly in a chair, walking at 1.3 m/s, running at 2.7 m/s, performing jumping jacks, doing a vertical leap, and jumping off a step approximately 20 cm high. Peak resultant head accelerations for each subject and activity were compared to determine if there were statistically significant differences based on variables such as gender and size. All measured accelerations were below 10 g with a maximum peak acceleration of 9.54 g recorded during the vertical leap activity. Larger head accelerations were measured during the jumping activities, while lower accelerations occurred during the sitting, walking, and running events. Based on the statistical analysis, it was determined that gender and size do not have a statistically significant effect on peak linear accelerations of the head during daily activities.

The biomechanical response of human bone: the influence of bone volume and mineral density.

The purpose of this study was to investigate the relationship between bone mineral density and the biomechanical response. This study presents results from 117 human rib cortical bone coupon tests from six cadavers, three male and three female, ranging in age from 18 to 67 years old. First, the material properties of human rib cortical bone were determined using dynamic tension coupon testing. The rib sections were taken from the anterior, lateral, and posterior regions on ribs 1 through 12 of each cadaver's rib cage. The cortical bone was isolated from each rib section with a low speed diamond saw, and milled into dog bone shaped tension coupons using a small computer numerical control machine. A high-rate servohydraulic Material Testing System equipped with a custom slack adaptor, to provide constant strain rates, was used to apply tension loads to failure at an average rate of 0.5 strains/sec. The elastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, and strain energy density were determined from the resulting stress versus strain curves. Second, two measures of bone mineral density (BMD) were determined: the global BMD of each cadaver through standard radiographic scaling, and the percent mineralization of each coupon through ash analysis. Overall, the global BMD was correlated with the biomechanical properties, but the local apparent density was not. The global BMD is actually a surrogate for the volume of bone present and it is highly correlated with subject age. In contrast, the apparent density is the true local BMD and it was not correlated with subject age. This is consistent with previous research and illustrates that the overall structural biomechanics of bone are related to the volume of bone, or global BMD, while they are much less related to the apparent density, or local BMD, which varies much less with age.

Thoracic and lumbar spine accelerations in everyday activities.

The purpose of this study was to quantify thoracic and lumbar spine accelerations for men and women of different body sizes during daily activities. Measured spine accelerations were compared to determine if there were significant differences in peak accelerations based on gender, size, and spine location. Each subject performed seven activities, which included sitting in a chair, sitting quickly in a chair, walking at 1.3 m/s, running at 2.7 m/s, performing jumping jacks, achieving maximum vertical leap, and jumping off a step approximately 20 cm high. Overall, the peak lumbar spine accelerations were significantly greater than the thoracic spine accelerations. Based on the statistical analysis, it was determined that gender and body size did not have a significant effect on peak accelerations of the thoracic and lumbar spine. The findings from the present study are of great value to researchers in order to understand the acceleration patterns of the human body during low impact accelerations.

Variability of gross tumor volume delineation in head-and-neck cancer using CT and PET/CT fusion.

PURPOSE: To assess the need for gross tumor volume (GTV) delineation protocols in head-and-neck cancer (HNC) treatment planning by use of positron emission tomography (PET)/computed tomography (CT) fusion imaging. Assessment will consist of interobserver and intermodality variation analysis. METHODS AND MATERIALS: Sixteen HNC patients were accrued for the study. Four physicians (2 neuroradiologists and 2 radiation oncologists) contoured GTV on 16 patients. Physicians were asked to contour GTV on the basis of the CT alone, and then on PET/CT fusion. Statistical analysis included analysis of variance for interobserver variability and Student's paired sample t test for intermodality and interdisciplinary variability. A Boolean pairwise analysis was included to measure degree of overlap. RESULTS: Near-significant variation occurred across physicians' CT volumes (p = 0.09) and significant variation occurred across physicians' PET/CT volumes (p = 0.0002). The Boolean comparison correlates with statistical findings. One radiation oncologist's PET/CT fusion volumes were significantly larger than his CT volumes (p < 0.01). Conversely, the other radiation oncologist's CT volumes tended to be larger than his fusion volumes (p = 0.06). No significant interdisciplinary variation was seen. Significant disagreement occurred between radiation oncologists. CONCLUSION: Significant differences in GTV delineation were found between multiple observers contouring on PET/CT fusion. The need for delineation protocol has been confirmed.

Risk functions for human and porcine eye rupture based on projectile characteristics of blunt objects.

Eye ruptures are among the most devastating eye injuries and can occur in automobile crashes, sporting impacts, and military events, where blunt projectile impacts to the eye can be encountered. The purpose of this study was to develop injury risk functions for globe rupture of both human and porcine eyes from blunt projectile impacts. This study was completed in two parts by combining published eye experiments with new test data. In the first part, data from 57 eye impact tests that were reported in the literature were analyzed. Projectile characteristics such as mass, cross-sectional area, and velocity, as well as injury outcome were noted for all tests. Data were sorted by species type and areas were identified where a paucity of data existed, based on the kinetic and normalized energy of assaulting objects. For the second part, a total of 126 projectile tests were performed on human and porcine eyes. Projectiles used for these tests included blunt aluminum projectiles, BBs, foam pellets, Airsoft pellets, and paintballs. Data for each projectile were recorded prior to testing and high-speed video was used to determine projectile velocity prior to striking the eye. In part three the data were pooled for a total of 183 eye impact tests, 83 human and 100 porcine, and were analyzed to develop the injury risk criteria. Binary logistic regression was used to develop injury risk functions based on kinetic and normalized energy. Probit analysis was used to estimate confidence intervals for the injury risk functions. Porcine eyes were found to be significantly stronger than human eyes in resisting globe rupture (p=0.01). For porcine eyes a 50% risk of globe rupture was found to be 71,145 J/m2, with a confidence interval of 63,245 J/m2 to 80,390 J/m2. Human eyes were found to have a 50% risk of globe rupture at a lower, 35,519 J/m2, with confidence intervals of 32,018 J/m2 to 40,641 J/m2. The results presented in this paper are useful in estimating the risk of globe rupture when projectile parameters are known, or can be used to validate computational eye models.

Determination of significant parameters for eye injury risk from projectiles.

BACKGROUND: Eye injuries affect a large proportion of the population and are expensive to treat. This article presents a parametric analysis of experimental data to determine the most significant factors for predicting ocular injuries or tissue lesions. METHODS: Using logistic regression, statistical values were generated to determine significant projectile characteristics for predicting ocular injury in published studies. Projectiles included BBs, metal rods, and foam particles with velocities ranging from 2 m/s to 122 m/s. RESULTS: A normalized energy (energy per projected area) value was found as the best predictor for ocular injury. Using this predictor, a 50% injury risk of corneal abrasion, lens dislocation, hyphema, retinal damage, and globe rupture was found to be 1,503 kg/s(2), 19,194 kg/s(2), 20,188 kg/s(2), 30,351 kg/s(2), and 23,771 kg/s(2), respectively. CONCLUSION: Normalized energy was the most significant predictor of injury type and tissue lesion. This finding is of great value for history-taking management triaging and as a design aid to minimize the risk of ocular injury for consumer products.

Customized conformal high-dose-rate brachytherapy boost for limited-volume nasopharyngeal cancer.

PURPOSE: To determine the feasibility of and patient outcomes using customized high-dose-rate (HDR) brachytherapy to boost the nasopharynx after external beam radiation therapy (EBRT) in patients with carcinoma of the nasopharynx. METHODS AND MATERIALS: Patients with nonmetastatic squamous cell carcinoma of the nasopharynx were treated using EBRT followed by a HDR brachytherapy boost delivered via customized catheters in a noninvasive, accurate, and reproducible method under direct fiber-optic visualization. Local control (LC), disease-free survival (DFS), and overall survival (OS) were analyzed. We also measured the change in maximum oral aperture as an indication of temporomandibular joint dysfunction. RESULTS: Between March 1996 and July 2003, we treated 38 patients with this customized brachytherapy method. The procedure was well tolerated without any incidents of soft-tissue or bone necrosis and with minimal decrease of oral aperture. Median follow-up time was 47 months (range, 2-84 months); 35 patients had at least 1 year of follow-up. The 5-year actuarial rate of LC, DFS, and OS were 96.0%, 81.4%, and 92.7%, respectively. CONCLUSIONS: The treatment has been well tolerated by all patients. The combination of conformal EBRT with our customized HDR brachytherapy boost has resulted in excellent local control to date, while minimizing temporomandibular joint dysfunction.

Material properties of human rib cortical bone from dynamic tension coupon testing.

The purpose of this study was to develop material properties of human rib cortical bone using dynamic tension coupon testing. This study presents 117 human rib cortical bone coupon tests from six cadavers, three male and three female, ranging in age from 18 to 67 years old. The rib sections were taken from the anterior, lateral, and posterior regions on ribs 1 through 12 of each cadaver's rib cage. The cortical bone was isolated from each rib section with a low speed diamond saw, and milled into dog bone shaped tension coupons using a small computer numerical control machine. A high-rate servo-hydraulic Material Testing System equipped with a custom slack adaptor, to provide constant strain rates, was used to apply tension loads to failure at an average rate of 0.5 strains/sec. The elastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, and strain energy density were determined from the resulting stress versus strain curves. The overall average of all cadaver data gives an elastic modulus of 13.9 GPa, a yield stress of 93.9 MPa, a yield strain of 0.88 %, an ultimate stress of 124.2 MPa, an ultimate strain of 2.7 %, and a strain energy density of 250.1 MPa-microstrain. For all cadavers, the plastic region of the stress versus strain curves was substantial and contributed approximately 60 % to the strain energy and over 80 % in the tests with the 18 year old cadaver. The rib cortical bone becomes more brittle with increasing age, shown by an increase in the modulus (p < 0.01) and a decrease in peak strain (p < 0.01). In contrast to previous three-bending tests on whole rib and rib cortical bone coupons, there were no significant differences in material properties with respect to rib region or rib level. When these results are considered in conjunction with the previous three-point bending tests, there is regional variation in the structural response of the human rib cage, but this variation appears to be primarily a result of changes in the local geometry of each rib while the material properties remain nearly constant within an individual.

Clinical experience using respiratory gated radiation therapy: comparison of free-breathing and breath-hold techniques.

PURPOSE: To investigate the clinical use of a commercially available gating system for minimizing respiratory-induced anatomic motion over a range of treatment sites. METHODS AND MATERIALS: The gating system consists of a reflective marker placed on the patient's anterior surface. The motion of the marker is tracked using a camera interfaced to a computer. Gated intervals were defined that limited the motion of the diaphragm to less than 1 cm during free breathing. Patients underwent a computed tomography virtual simulation using a breath-hold technique. At the time of treatment, verification of patient position and gating interval were performed using electronic portal imaging. RESULTS: Between September 2000 and January 2002, 136 patients were simulated with respiratory gating. Of these, 108 patients were treated to 110 sites for a total of 2301 treatment sessions. Ninety-seven percent of patients completed their entire course of therapy with gated treatment delivery. CONCLUSIONS: Respiratory gating is a practical and achievable solution for minimizing respiratory-induced target motion during both simulation and treatment. With proper patient selection and training, it can be successfully implemented in a clinical radiation therapy department.

Palladium-103 plaque radiotherapy for choroidal melanoma: an 11-year study.

PURPOSE: To describe 11 years of experience with 103Pd ophthalmic plaque brachytherapy for intraocular melanoma. METHODS AND MATERIALS: Since 1990, 152 patients have been diagnosed with uveal melanoma, found to be negative for metastatic disease, and treated with 103Pd radioactive plaque radiotherapy. This study presents the first 100 patients treated with 103Pd and followed for > or = 2 years. Plaques were sewn to the episclera to cover the base of the intraocular tumor. Treatment involved delivery of a mean apical radiation dose of 80.5 Gy during 5-7 days' continuous treatment. Patients were evaluated for local tumor control, visual acuity, radiation damage (retinopathy, optic neuropathy, cataract), and metastatic disease. RESULTS: Patients in this series were followed for a mean of 4.6 years (55.4 months). 103Pd seeds were found to be equivalent to 125I with respect to plaque manufacture and ease of dosimetric calculations. We noted a local control rate of 96% and six secondary enucleations. Including the enucleated patients, the visual acuity evaluations revealed that 35% lost six or more lines of vision and 73% had vision of 20/200 or better. CONCLUSION: Long-term results now exist describing the use of 103Pd plaque radiotherapy for uveal (iris, ciliary body, and choroidal) melanoma. Compared with the results from centers using 125I, patients in this series experienced equivalent local control rates and better visual function.