A graded forceps crush spinal cord injury model in mice

Given the rising availability and use of genetically modified animals in basic science research, it has become increasingly important to develop clinically relevant models for spinal cord injury (SCI) for use in mice. We developed a graded forceps crush model of SCI in mice that uses three different forceps with spacers of 0.25, 0.4, and 0.55 mm, to produce severe, moderate, and mild injuries, respectively. Briefly, each mouse was subjected to laminectomy of T5-T7, 15-second spinal cord crush using one of those forceps, behavioral assessments, and post-mortem neuroanatomical analyses. There were significant differences among the three injury severity groups on behavioral measures (Basso Mouse Score, footprint, and ladder analyses), demonstrating an increase in neurological deficits for groups with greater injury severity. Quantitative analysis of the lesion demonstrated that as injury severity increased, lesion size and GFAP negative area increased, and spared tissue, spinal cord cross-sectional area, spared grey matter and spared white matter decreased. These measures strongly correlated with the behavioral outcomes. Similar to other studies of SCI in mice, we report a dense laminin and fibronectin positive extracellular matrix in the lesion sites of injured mice, but unlike those previous studies, we also report the presence of numerous p75 positive Schwann cells in and around the lesion epicenter. These results provide evidence that the graded forceps crush model is an attractive alternative for the study of SCI and related therapeutic interventions. Because of its demonstrated consistency, ease of use, low cost, and clinical relevance, this graded forceps crush is an attractive alternative to the other mouse models of SCI currently available.     

Morbidity Associated With High Gastrocnemius Recession: Retrospective Review of 126 Cases

To evaluate morbidity associated with surgical lengthening of the gastrocnemius, medical records were reviewed retrospectively for 126 patients (mean age, 49.7 years; range, 8-78 years) who had undergone open gastrocnemius recession. Ten patients had isolated recession; 116 had gastrocnemius recession with an additional foot or ankle procedure on the ipsilateral limb. During a mean follow-up period of 19 months (range, 6-50 months), all patients were examined for any postoperative complications associated with the recession. Complications were defined as the presence of postoperative infection, wound dehiscence, nerve problems, decreased muscle strength, scar problems, or calcaneus gait (overlengthening). Uncomplicated outcome was defined as absence of all these complications and return to regular activity, both occurring during a follow-up of at least 6 months. Postsurgical complications developed in 9 (6%) of the 126 patients: 6 (4%) had scar problems, 2 (1.33%) had wound dehiscence, 2 (1.33%) had infection, 3 (2%) had nerve problems, and 1 (0.67%) developed complex regional pain syndrome. No patient complained of either a limp or gait disturbance. Neither persistent decrease in muscle strength nor calcaneus gait was seen. These data suggest that the open gastrocnemius recession procedure has low associated morbidity.     

Relationship of tinnitus questionnaires to depressive symptoms, quality of well-being, and internal focus

Twenty percent of people endure tinnitus to a degree that their quality of well-being and productivity in life are impaired, and up to 60% report depression. Four measures are widely used to assess tinnitus-related distress, yet the relationship among all four measures or their relationship to relevant psychiatric variables has yet to be studied. This study assessed the association between the four commonly used measures of tinnitus and their relationship to depressive symptoms, quality of well-being, and internal focus. Sixty-five people with tinnitus completed the following measures: Iowa Tinnitus Handicap Questionnaire (THQ); Tinnitus Reaction Questionnaire (TRQ); Tinnitus Handicap Inventory (THI); Tinnitus Questionnaire (TQ); Hamilton Rating Scale for Depression (HRSD); Beck Depression Inventory (BDI); Quality of Well-Being Scale (QWBS); Modified Somatic Perception Questionnaire (MSPQ); and Private Self-Consciousness Scale (PSCS). All the tinnitus measures were highly intercorrelated (r = .76-.90; all p values < .001), and related to depressive symptoms (r = .48-.66; p < .001) and QWBS (r = .37-.48; all p values < 0.008). The tinnitus measures correlated with the MSPQ (r = .37-.52; all p values < .01) but not with the PSCS. When controlling for the shared variance between tinnitus measures, the THQ independently predicted the HRSD, whereas the TRQ independently predicted the BDI.     

Pediatricians' Perspectives on Indoor Tanning

This report presents results from an online survey of New York State pediatricians regarding their counseling habits and attitudes toward indoor tanning among adolescents, as well as their awareness of current legislation that restricts youth access to tanning beds.     

Effects of stimulation rate on speech recognition with cochlear implants

Phoneme and speech recognition were measured as a function of stimulation pulse rate in 12 listeners with three types of cochlear implants. Identification of consonants and vowels and recognition of words and sentences were measured in 5 Clarion C1 subjects fit with continuous interleaved sampling (CIS) processors having 4 or 8 electrodes, 4 Nucleus 24 subjects fit with CIS processors having 4, 8, 12 or 16 electrodes and 3 Clarion C2 subjects fit with CIS processors with 4, 8, 12 and 16 electrodes. Stimulation rates ranged from 200 to more than 5000 Hz per electrode, depending on the device, number of electrodes used and stimulation strategy. Listeners were also tested on the same materials with their original processor prior to receiving the experimental processors. All testing was done in quiet listening conditions with essentially no practice with the experimental processor prior to data collection. Listeners scored the highest with their original processor. Little difference in speech understanding was observed for listener scores with processors using different stimulation rates. Speech recognition was significantly poorer only at the lowest stimulation rate and at high rates that used noninterleaved pulses. Speech recognition was similar for processors using 8, 12 or 16 electrodes. Only 4-electrode processors produced a significantly poorer performance. These results suggest that patients with present commercial implants are not able to make full use of the number of channels of spectral information delivered by the present speech processors. In addition, the results show no significant change in performance as a function of stimulation rate, suggesting that high stimulation rates do not result in improved access to temporal cues in speech, at least under quiet listening conditions.     

Revealing the spatial distribution of a disease while preserving privacy

Datasets describing the health status of individuals are important for medical research but must be used cautiously to protect patient privacy. For patient data containing geographical identifiers, the conventional solution is to aggregate the data by large areas. This method often preserves privacy but suffers from substantial information loss, which degrades the quality of subsequent disease mapping or cluster detection studies. Other heuristic methods for de-identifying spatial patient information do not quantify the risk to individual privacy. We develop an optimal method based on linear programming to add noise to individual locations that preserves the distribution of a disease. The method ensures a small, quantitative risk of individual re-identification. Because the amount of noise added is minimal for the desired degree of privacy protection, the de-identified set is ideal for spatial epidemiological studies. We apply the method to patients in New York County, New York, showing that privacy is guaranteed while moving patients 25—150 times less than aggregation by zip code.