Interdisciplinary Undergraduate Laboratory for an Integrated Chemistry/Biology Program: Synthesis of Silver Nanoparticles (AgNPs)-Cellulose Composite Materials with Antimicrobial Activity.

This laboratory exercise integrates chemistry and biology concepts to give third/fourth-year undergraduate students an opportunity to apply knowledge from different subject areas to address a real-world biomedical issue such as pathogen inhibition using composite materials. It involves the preparation of a bacteria-derived cellulosic biopolymer through microbial cultivation, impregnation of the bacterial cellulose (BC) with silver nanoparticles (AgNPs), followed by the analysis of the materials and the antimicrobial properties of the biomaterial-AgNPs composites. The methods are relatively simple and use inexpensive chemicals. A Tollens type approach is adopted to produce silver nanoparticles-bacterial cellulose (AgNPs-BC) composites by the reduction of [Ag(NH3)2]+ complex embedded in the cellulose matrix. The samples were dried by two different methods: freeze-drying or vacuum-drying. The dried AgNPs-BC films were evaluated for antimicrobial properties against a test organism, in this example, Pseudomonas aeruginosa, a Gram-negative biosafety containment level 2 (BSL 2) bacterium, using an agar diffusion test. For additional flexibility and customization, options for dividing the chemistry/biology content of this laboratory into smaller units with an emphasis on characterization techniques of nanomaterials for chemistry majors are also discussed.

Long-term impact of abusive head trauma in young children.

OBJECTIVE: Abusive head trauma is the leading cause of physical abuse deaths in children under the age of 5 and is associated with severe long-lasting health problems and developmental disabilities. This study evaluates the long-term impact of AHT and identifies factors associated with poor long-term outcomes (LTOs). METHODS: We used the Truven Health MarketScan Research Claims Database (2000-2015) to identify children diagnosed with AHT and follow them up until they turn 5. We identified the incidence of behavioral disorders, communication deficits, developmental delays, epilepsy, learning disorders, motor deficits, and visual impairment as our primary outcomes. RESULTS: The incidence of any disability was 72% (676/940) at 5 years post-injury. The rate of developmental delays was 47%, followed by 42% learning disorders, and 36% epilepsy. Additional disabilities included motor deficits (34%), behavioral disorders (30%), visual impairment (30%), and communication deficits (11%). Children covered by Medicaid experienced significantly greater long-term disability than cases with private insurance. In a propensity-matched cohort that differ primarily by insurance, the risk of behavioral disorders (RD 36%), learning disorders (RD 30%), developmental delays (RD 30%), epilepsy (RD 18%), and visual impairment (RD 12%) was significantly higher in children with Medicaid than kids with private insurance. CONCLUSION: AHT is associated with a significant long-term disability (72%). Children insured by Medicaid have a disproportionally higher risk of long-term disability. Efforts to identify and reduce barriers to health care access for children enrolled in Medicaid are critical for the improvement of outcomes and quality of life.

Characteristics of Rib Fractures in Child Abuse-The Role of Low-Dose Chest Computed Tomography.

OBJECTIVES: Our aim is to describe the radiologic characteristics of rib fractures in clinically diagnosed cases of child abuse and suggest a complementary imaging for radiographically occult injuries in highly suspicious cases of child abuse. METHODS: Retrospective analysis of initial and follow-up skeletal surveys and computed tomography (CT) scans of 16 patients younger than 12 months were reviewed after obtaining approval from our institutional review board. The number, location, displacement, and age of the rib fractures were recorded. RESULTS: Out of a total 105 rib fractures, 84% (87/105) were detected on the initial skeletal survey. Seventeen percent (18/105) were seen only after follow-up imaging, more than half of which (11/18) were detected on a subsequent CT. Majority of the fractures were posterior (43%) and anterior (30%) in location. An overwhelming majority (96%) of the fractures are nondisplaced. CONCLUSIONS: Seventeen percent of rib fractures analyzed in the study were not documented on the initial skeletal survey. Majority of fractures are nondisplaced and located posteriorly or anteriorly, areas that are often difficult to assess especially in the acute stage. The CT scan is more sensitive in evaluating these types of fractures. Low-dose chest CT can be an important imaging modality for suspicious cases of child abuse when initial radiographic findings are inconclusive.

Blunt Intraoral Trauma Resulting in Internal Carotid Artery Dissection and Infarction in a Child.

A 16-month-old child fell forward onto her toothbrush sustaining minor oropharyngeal injury. The following day, she became acutely lethargic with localizing neurologic signs of a cerebrovascular infarct. CTA and MR imaging demonstrated occlusion of the right internal carotid artery with a large right middle cerebral artery territory infarction. She was treated with decompressive craniectomy and anticoagulation but remained weak on the left side. Pediatric oropharyngeal injuries can rarely be complicated by internal carotid artery injury with dissection, thrombosis, or embolization to the cerebral circulation. For the best outcome, carotid dissection treatment requires prompt diagnosis at the initial onset of neurologic symptoms. However, further research is needed to determine the best management and advanced imaging work-up for neurologically intact children.

CT of the chest in suspected child abuse using submillisievert radiation dose.

The cornerstone of child abuse imaging is the skeletal survey, but initial imaging with radiographs may not demonstrate acute and non-displaced fractures, especially those involving the ribs. Given the high mortality of undiagnosed non-accidental trauma, timely diagnosis is crucial. CT is more sensitive in assessing rib fractures; however the effective radiation dose of a standard chest CT is high. We retrospectively identified four children (three boys, one girl; age range 1-4 months) admitted between January 2013 and February 2014 with high suspicion for non-accidental trauma from unexplained fractures of the long bones; these children all had CT of the chest when no rib fractures were evident on the skeletal survey. The absorbed radiation dose estimates for organs and tissue from the four-view chest radiographs and subsequent CT were determined using Monte Carlo photon transport software, and the effective dose was calculated using published tissue-weighting factors. In two children, CT showed multiple fractures of the ribs, scapula and vertebral body that were not evident on the initial skeletal survey. The average effective dose for a four-view chest radiograph across the four children was 0.29 mSv and the average effective dose for the chest CT was 0.56 mSv. Therefore the effective dose of a chest CT is on average less than twice that of a four-view chest radiograph. Our protocol thus shows that a reduced-dose chest CT may be useful in the evaluation of high specificity fractures of non-accidental trauma when the four-view chest radiographs are negative.

Children's memory and suggestibility about a distressing event: the role of children's and parents' attachment.

Our goal was to identify individual difference predictors of children's memory and suggestibility for distressing personally experienced events. Specifically, we examined children's and parents' attachment orientations and children's observable levels of distress, as well as other individual difference factors, as predictors of children's memory and suggestibility. Children (N=91) aged 3 to 6years were interviewed about inoculations received at medical clinics. For children whose parents scored as more avoidant, higher distress levels during the inoculations predicted less accuracy, whereas for children whose parents scored as less avoidant, higher distress levels predicted greater accuracy. Children with more rather than less positive representations of parents and older rather than younger children answered memory questions more accurately. Two children provided false reports of child sexual abuse. Implications for theory, research, and practice are discussed.

Optimizing bone surveys performed for suspected non-accidental trauma with attention to maximizing diagnostic yield while minimizing radiation exposure: utility of pelvic and lateral radiographs.

BACKGROUND: Skeletal surveys for non-accidental trauma (NAT) include lateral spinal and pelvic views, which have a significant radiation dose. OBJECTIVE: To determine whether pelvic and lateral spinal radiographs should routinely be performed during initial bone surveys for suspected NAT. MATERIALS AND METHODS: The radiology database was queried for the period May 2005 to May 2011 using CPT codes for skeletal surveys for suspected NAT. Studies performed for skeletal dysplasia and follow-up surveys were excluded. Initial skeletal surveys were reviewed to identify fractures present, including those identified only on lateral spinal and/or pelvic radiographs. Clinical information and MR imaging was reviewed for the single patient with vertebral compression deformities. RESULTS: Of the 530 children, 223 (42.1%) had rib and extremity fractures suspicious for NAT. No fractures were identified solely on pelvic radiographs. Only one child (<0.2%) had vertebral compression deformities identified on a lateral spinal radiograph. This infant had rib and extremity fractures and was clinically paraplegic. MR imaging confirmed the vertebral body fractures. CONCLUSION: Since no fractures were identified solely on pelvic radiographs and on lateral spinal radiographs in children without evidence of NAT, nor in nearly all with evidence of NAT, inclusion of these views in the initial evaluation of children for suspected NAT may not be warranted.

Follow-up skeletal surveys for suspected non-accidental trauma: can a more limited survey be performed without compromising diagnostic information?

OBJECTIVE: Follow-up skeletal surveys have been shown to improve the rate of fracture detection in suspected cases of non-accidental trauma (NAT). As these studies are performed in a particularly radiosensitive population, it is important to evaluate if all of the (approximately 20) radiographs obtained at repeat skeletal survey are clinically useful. Our goal was to evaluate if certain radiographs can be excluded at follow-up skeletal survey without compromising the clinical efficacy. METHODS: This retrospective study included 22 cases of suspected NAT (average age 3.8 months, range 0.7-15 months) in which patients received both initial and follow-up bone surveys. The follow-up survey was performed an average of 16.7 days (range 11-29 days) after the initial survey. Radiographs were reviewed by 2 pediatric radiologists, with discrepancies resolved by consensus. In addition, we combined our data with data from all known previously published reports of follow-up skeletal surveys for NAT for meta-analysis. RESULTS: A total of 36 fractures were found on the initial bone survey in 16/22 patients (73%). Six patients had no fractures detected at initial survey. Follow-up bone surveys demonstrated an additional 3 fractures (2 extremities and 1 rib) in 3/22 cases (14%); 1 was in a patient whose initial survey was negative. No additional fractures in the skull, spine, pelvis, feet, or hands were detected in any case. In combination with patients reported in the literature (194 patients total) no new fracture of the skull, spine, pelvis, or hands was detected at follow-up survey. The skull, spine and pelvis radiographs are the highest dose-exposure studies of the skeletal survey. CONCLUSION AND PRACTICE IMPLICATIONS: If no injury is detected or suspected in the pelvis, spine, hands, or skull at initial bone survey for suspected NAT, a limited follow-up skeletal survey which excludes the pelvis, lateral spine, hands, and skull should be considered to limit radiation exposure without limiting diagnostic information.

Comparison of computed tomography and chest radiography in the detection of rib fractures in abused infants.

PURPOSE: Chest radiographs (CXR) are the standard method for evaluating rib fractures in abused infants. Computed tomography (CT) is a sensitive method to detect rib fractures. The purpose of this study was to compare CT and CXR in the evaluation of rib fractures in abused infants. METHODS: This retrospective study included all 12 abused infants identified from 1999 to 2004 who had rib fractures and both CXR and CT (8 abdomen CTs, 4 chest CTs). CT exams had been performed for clinical indications, and were obtained within one day of the CXR. Studies were reviewed by two pediatric radiologists to determine the number, locations, and approximate ages of the rib fractures. A total of 225 ribs were completely (192) or partially (33) seen by CT, and the matched ribs on CXR were used for the analysis. RESULTS: The mean patient age was 2.5 months (1.2-5.6), with seven females and five males. While 131 fractures were visualized by CT, only 79 were seen by CXR (p<.001). One patient had fractures only seen by CT. There were significantly (p<.05) more early subacute (24 vs. 4), subacute (47 vs. 26), and old fractures (4 vs. 0) seen by CT than by CXR. Anterior (42 vs. 11), anterolateral (21 vs. 12), posterolateral (9 vs. 3) and posterior (39 vs. 24) fractures were better seen by CT than by CXR (p<.01). Bilateral fractures were detected more often by CT (11) than by CXR (6). CONCLUSIONS: While this study group is small, these findings suggest that CT is better than CXR in visualizing rib fractures in abused infants.