Higher risk of auto versus pedestrian crashes in school-age children on school days.

BACKGROUND: This study examines the rates of pediatric auto versus pedestrian collision (APCs) and determined ages and periods of greatest risk. We hypothesized that the rate of APC in children would be higher on school days and in the timeframes correlating with travel to and from school. METHODS: Retrospective case-control study of APC on school and nonschool days for patients younger than 18 years at an urban Level II pediatric trauma center from January 2011 to November 2019. Frequency of APC by hour of the day was plotted overall, for school versus nonschool days and for age groups: 0 year to 4 years, 5 years to 9 years, 10 years to 13 years, and 14 years to 17 years. t Test was used with a p value less than 0.05, which was considered significant. RESULTS: There were 441 pediatric APC in the study period. Frequency of all APC was greater on school days (0.174 vs. 0.101; relative risk [RR], 1.72, p < 0.001), and APC with Injury Severity Score greater than 15 (0.039 vs. 0.024; p = 0.014; RR, 1.67; 95% confidence interval, 1.10-2.56). Comparing school day with nonschool day, the 0-year to 4-year group had no significant difference in APC frequency (0.021 vs. 0.014; p = 0.129), APC frequency was higher on school days in all other age groups: 5 years to 9 years (0.036 vs. 0.019; RR, 1.89; p = 0.0134), 10 years to 13 years (0.055 vs. 0.024; RR, 2.29; p < 0.001), and 14 years to 17 years (0.061 vs. 0.044; RR, 1.39; p = 0.045). The greatest increase in APC on school days was in the 10-year to 13-year age group. DISCUSSION: All school age children are at higher risk of APC on school days. The data support our hypothesis that children are at higher risk of APC during transit to and from school. The age 10-year to 13-year group had a 129% increase in APC frequency on school days. This age group should be a focus of injury prevention efforts. LEVEL OF EVIDENCE: Prognostic and Epidemiologic; Level IV.

Satellite cell activity is differentially affected by contraction mode in human muscle following a work-matched bout of exercise.

Optimal repair and adaptation of skeletal muscle is facilitated by resident stem cells (satellite cells). To understand how different exercise modes influence satellite cell dynamics, we measured satellite cell activity in conjunction with markers of muscle damage and inflammation in human skeletal muscle following a single work- and intensity-matched bout of eccentric (ECC) or concentric contractions (CON). Participants completed a single bout of ECC (n = 7) or CON (n = 7) of the knee extensors. A muscle biopsy was obtained before and 24 h after exercise. Functional measures and immunohistochemical analyses were used to determine the extent of muscle damage and indices of satellite cell activity. Cytokine concentrations were measured using a multiplexed magnetic bead assay. Isokinetic peak torque decreased following ECC (p < 0.05) but not CON. Greater histological staining of the damage marker Xin was observed in muscle samples of ECC vs. CON. Tenasin C immunoreactivity increased 15 fold (p < 0.01) following ECC and was unchanged following CON. The inflammatory cytokines interferon gamma-induced protein 10 (IP-10) and monocyte chemotactic protein 1 (MCP-1) increased pre- to post-ECC (4.26 ± 1.4 vs. 10.49 ± 5.8 pg/ml, and 3.06 ± 0.7 vs. 6.25 ± 4.6 pg/ml, respectively; p < 0.05). There was no change in any cytokine post-CON. Satellite cell content increased 27% pre- to post-ECC (0.10 ± 0.031 vs. 0.127 ± 0.041, respectively; p < 0.05). There was no change in satellite cell number in CON (0.099 ± 0.027 vs. 0.102 ± 0.029, respectively). There was no fiber type-specific satellite cell response following either exercise mode. ECC but not CON resulted in an increase in MyoD positive nuclei per myofiber pre- to post-exercise (p < 0.05), but there was no change in MyoD DNA binding activity in either condition. In conclusion, ECC but not CON results in functional and histological evidence of muscle damage that is accompanied by increased satellite cell activity 24 h post-exercise.

Carcinomatous meningitis from urachal carcinoma: the first reported case.

Carcinomatous meningitis (CM) occurs in less than 10% of cancer patients. Although patients frequently present with a focal complaint, multifocal signs are often found following careful neurological examination. The gold standard for diagnosis remains the demonstration of neoplastic cells in the cerebrospinal fluid. Despite the discouraging prognosis, palliative treatment may improve quality of life and lengthen lifespan. We report a patient with known primary carcinoma of the urachus who presented with headaches, nausea, vomiting and ataxia 1 week following resection of a nodular arachnoidal metastasis (indenting the cerebellum). Lumbar cerebrospinal fluid subsequently confirmed carcinomatous meningitis. This is the first reported case of carcinomatous meningitis resulting from metastatic urachal carcinoma.

Cerebellar pilocytic astrocytoma with auditory presentation: case study.

An 8-year-old girl complained of decreased hearing and difficulty hearing from her right ear while on the telephone. Pure-tone and speech audiometry, immittance (tympanometry, acoustic reflex thresholds), auditory brainstem response, and transient click-evoked otoacoustic emissions were administered. The results were suggestive of a space-occupying lesion, and the patient was referred to a pediatric neurologist and neurosurgeon. A cerebellar pilocytic astrocytoma was found. The patient's audiologic profile is described, along with implications for pediatric neurologic evaluations.