Case series investigating the cortical silent period after burns using transcranial magnetic stimulation

Objective

The study aimed to investigate intracortical inhibition following a burn injury, and to establish transcranial magnetic stimulation (TMS) as a useful and sensitive tool to investigate the cortical response to a burn injury.

ADC mapping of neurodegeneration in the brainstem and cerebellum of patients with progressive ataxias

Analysis of the apparent diffusion coefficient (ADC) maps derived from diffusion-weighted MR imaging is emerging as a reproducible, sensitive, and quantitative tool to evaluate brain damage in diseases of the white and gray matter. To explore the potentials of ADC maps analysis in degenerative ataxias, we examined 28 patients and 26 age-matched controls with T1, T2, and diffusion (b values 0-1000 along the three main body axes)-weighted MR images. Twenty-four patients had inherited genetically proven diseases including spinocerebellar ataxia type 1 (SCA1) (n = 9), spinocerebellar ataxia type 2 (SCA2) (n = 8), and Friedreich's ataxia (FA) (n = 7), whereas four patients had sporadic adult onset pure cerebellar ataxia (three idiopathic, one gluten intolerance). Area and linear measurements of the CNS structures contained in the posterior cranial fossa (PCF) preliminary enabled classification of the patients in the three morphological categories reflecting the gross pathology findings, namely olivopontocerebellar atrophy (OPCA) (n = 10: six SCA2 and four SCA1), spinal atrophy (SA) (n = 7: all FA), and cortical cerebellar atrophy (CCA) (n = 4: three idiopathic and one gluten intolerance). Seven patients with SCA1 (n = 5) or SCA2 (n = 2) had morphologic changes reminiscent of OPCA, but their values were still in the lower normal range and were classified as undefined. Mean diffusivity (D) maps of the entire brain were generated and D was measured with regions of interest (ROI) in the medulla, pons, middle cerebellar peduncles, and the peridentate white matter. Moreover, after exclusion of the skull with manual segmentation and of the CSF with application of a threshold value, histograms were obtained for D of the brainstem and cerebellum and for D of the cerebral hemispheres. As compared to controls, a (P < 0.001) increase of D was observed in the medulla, middle cerebellar peduncles, and peridentate white matter in OPCA and undefined patients groups who had also significantly increased values of the 25th and 50th percentiles in the brainstem and cerebellum D histogram. In CCA (P = 0.01), an increase of the 25th and 50th percentile of the D value was observed in the brainstem and cerebellum histograms. The SA group showed (P < 0.001) an increased D in the medulla only. A correlation between clinical severity as assessed with the Inherited Ataxias Clinical Rating Scale (IACRS) and the 50th percentile of the D value in the brainstem and cerebellum histogram (r = 0.69) was observed in patients with SCA1 or SCA2. Diffusion MR imaging reveals variable patterns of increase of D in the brainstem, cerebellum, and cerebral hemispheres in degenerative ataxias that match the known distribution of the neuropathological changes.     

A survey of non-consultant career grade doctors in genitourinary medicine: their knowledge of guidelines and their access to information technology 2001

Non-consultant career grade (NCCG) doctors in genitourinary medicine (GUM) perform a large proportion of the clinical work. To ensure quality of service delivery to patients, it is essential that these doctors keep up to date. Seven hundred questionnaires were sent to NCCGs in the UK to evaluate their knowledge of national guidelines and access to information technology. A summary of the 224 replies (31% response) is presented. Knowledge of guidelines (76%-86%) and access to the Internet at work (39%-44%) varied according to the number of sessions worked in GUM per week and by grade of doctor. Knowledge of relevant websites was poor, ranging from 40%-54% for the Medical Society for the Study of Venereal Diseases (MSSVD) website and 21%-39% for the Association of Genitourinary Medicine (AGUM) website. This survey highlights areas for concern, especially with regard to NCCGs who work three or less GUM sessions per week.     

The Impact of Emerging Liquid Preference in the Treatment of Liquid Refusal

Treatment of liquid refusal in pediatric feeding disorders is essential for decreasing tube dependence, alleviating some medical conditions (e.g., constipation), and increasing caloric and nutritional intake (e.g., formulas). Although investigators have conducted edible preference assessments for solids, there are no studies to our knowledge in which investigators have evaluated liquid preference prior to and during treatment of liquid refusal. In the current study, we evaluated liquid preferences repeatedly over time during behavioral treatment for liquid refusal. Although none of the children demonstrated a preference for liquids during a paired-choice preference assessment, 2 of the 3 children showed a preference when we implemented an avoidance component. However, for all 3 children, latency to acceptance and inappropriate mealtime behavior decreased for liquids during behavioral treatment with undifferentiated responding between liquid types. Future research may evaluate the utility and correlation of liquid preference assessments preceding treatment for liquid refusal.     

Self-Report of Outpatient Therapy Dose at 6 and 12 Months After Severe Traumatic Brain Injury

Objective

Determine agreement between self-reported dose and dose reflected in administrative records of outpatient physical, occupational, and speech therapies at 6 and 12 months after severe traumatic brain injury (TBI), for the purpose of examining accuracy and predictors of accuracy of self-reported health care utilization in this population.

Absorption, distribution, metabolism, and excretion of [1-¹⁴C]-perfluorohexanoate ([¹⁴C]-PFHx) in rats and mice

The absorption, tissue distribution, elimination, and metabolism of [1-¹⁴C]-PFHx in rats and mice dosed orally at 2 or 100 mg/kg was evaluated following a single dose or after 14 consecutive doses. Absorption was rapid in rats as evidenced by a short time to maximum concentration (C_max) of 30 min in male rats and 15 min in female rats at both the 2 and 100 mg/kg dose level. The plasma elimination half-life was somewhat longer in males (1.5-1.7 h) than in females (0.5-0.7 h). Absorption in the mouse was also rapid with the maximum plasma concentration occurring between 15 and 30 min after dosing. The maximum concentration was not appreciably different between male and female mice (8 μg equiv./g at 2 mg/kg; ∼350 μg equiv./g at 100 mg/kg). The primary route of elimination was via the urine. PFHx was not metabolized in rat or mouse hepatocytes, nor were any metabolites observed after oral dosing in either rodent species. Essentially 100% of the dose was eliminated in urine within 24 h demonstrating that PFHx is readily absorbed and bioavailability approaches 100%, even at a dose as high as 100 mg/kg. The route and extent of elimination was unchanged after 14 days of daily dosing. Tissues were collected at three time points (rat: 0.5, 2, and 24 h; mice: 0.25, 1, and 24 h) after dosing to investigate the tissue clearance kinetics of PFHx following a single dose at 2 or 100 mg/kg. In all tissues except skin, PFHx was not quantifiable 24 h after dosing in both sexes of the two species.     

8:2 fluorotelomer alcohol: a one-day nose-only inhalation toxicokinetic study in the Sprague-Dawley rat with application to risk assessment

8:2 fluorotelomer alcohol (8:2 FTOH) inhalation exposure was investigated to (1) compare plasma metabolites to oral data, (2) conduct a route-to-route extrapolation (oral to inhalation), (3) develop a human equivalent air concentration (HEC) from a 90-day oral sub-chronic study in rats using BMD analysis, and (4) calculate a margin of exposure (MOE) between the HEC and measured air concentrations. Male and female rats were exposed nose-only for 6h at 3 or 30mg/m(3). Blood was collected at 1, 3 and 6h during exposure and 6 and 18h post exposure. Alcohol, perfluorocarboxylic acid and polyfluorinated acid metabolites were determined in plasma by LC-MS/MS. 8:2 FTOH was 相似文献   

Biomedical engineering strategies for peripheral nerve repair: surgical applications, state of the art, and future challenges

Damage to the peripheral nervous system is surprisingly common and occurs primarily from trauma or a complication of surgery. Although recovery of nerve function occurs in many mild injuries, outcomes are often unsatisfactory following severe trauma. Nerve repair and regeneration presents unique clinical challenges and opportunities, and substantial contributions can be made through the informed application of biomedical engineering strategies. This article reviews the clinical presentations and classification of nerve injuries, in addition to the state of the art for surgical decision-making and repair strategies. This discussion presents specific challenges that must be addressed to realistically improve the treatment of nerve injuries and promote widespread recovery. In particular, nerve defects a few centimeters in length use a sensory nerve autograft as the standard technique; however, this approach is limited by the availability of donor nerve and comorbidity associated with additional surgery. Moreover, we currently have an inadequate ability to noninvasively assess the degree of nerve injury and to track axonal regeneration. As a result, wait-and-see surgical decisions can lead to undesirable and less successful "delayed" repair procedures. In this fight for time, degeneration of the distal nerve support structure and target progresses, ultimately blunting complete functional recovery. Thus, the most pressing challenges in peripheral nerve repair include the development of tissue-engineered nerve grafts that match or exceed the performance of autografts, the ability to noninvasively assess nerve damage and track axonal regeneration, and approaches to maintain the efficacy of the distal pathway and targets during the regenerative process. Biomedical engineering strategies can address these issues to substantially contribute at both the basic and applied levels, improving surgical management and functional recovery following severe peripheral nerve injury.