Intraspinal penetrating stab injury to the middle thoracic spinal cord with no neurologic deficit

The annual incidence of traumatic spinal cord injury worldwide is estimated to be 35 patients per million. Nonmissile penetrating spinal injuries most commonly occur in the thoracic region, and the majority has neurologic deficits on admission. The management of patients who lack neurologic deficits is controversial due to the risk of neurologic status alteration intraoperatively. However, failure to intervene increases the risk of infection, delayed onset of neurologic deficits, and worsening functional outcome.A 17-year-old boy presented with an intradural T7-T8 knife penetration injury to the spinal cord with no neurologic deficit. Rapid surgical intervention was critical because the knife was lodged between the 2 hemispheres of the spinal cord. The patient was intubated in the lateral position, transferred to the prone position on a Jackson table, and underwent surgical decompression with laminectomy 1 level above and below the injury site, removal of the knife blade in the original path of trajectory, and repair of the dural tear with a collagen matrix. The patient sustained no neurologic sequelae from the penetrating knife injury. He was able to ambulate at discharge and had no complications. To our knowledge, this is the only report of a patient with intradural spinal cord penetration by a foreign object (knife blade) presenting with a normal neurologic preoperative examination that persisted throughout the course of postoperative care.     

Non-promoting effects of lean beef in the rat colon carcinogenesis model

Recent epidemiologic studies have implicated red meat consumptionas a risk factor for colon cancer in both men and women. However,it has been very difficult to separate the effects of meat asa protein source from the accompanying fat content of the dietsanalyzed in these studies. Experimental data from rodent feedingtrials show mixed results, with no firm conclusions being possiblein terms of the colon-cancer promoting effects of meat fat.The goal of the present study was to compare, in an experimentalanimal model, the effects of beef with casein as a protein source,within the context of a low- and high-fat diet containing eithercorn oil or beef tallow, on promotion of colon carcinogenesis.Tumors were induced in Sprague— Dawley rats with 1,2-dimethylhydrazine(20 mg/kg body wt for 10 weeks). Two hundred and eighty maleweanling rats were randomized to eight dietary treatment groupsof a 2x2x2 factorial design with fat source (corn oil vs. beeftallow), fat level (5% vs. 20%), and protein source (very leanbeef vs. casein) as the factors. Diets were fed ad libitum before,during and after carcinogen treatment for a total of 27 weeks.At termination of the study, animals were examined for location,size and type of colon or extracolonic lesions. The total incidenceand number of colon tumors were significantly lower in the groupsfed beef rather than casein. High fat levels, regardless ofsource, significantly increased the number of colon adenomas.These results demonstrate that when lean beef is used as theprotein source in the context of a low-fat diet, fewer intestinaltumors develop. These data do not support the belief that redmeat consumption increases the risk for colon cardnogenesis,but underscores the importance of fat level in dietary context.     

EEG source imaging.

OBJECTIVE: Electroencephalography (EEG) is an important tool for studying the temporal dynamics of the human brain's large-scale neuronal circuits. However, most EEG applications fail to capitalize on all of the data's available information, particularly that concerning the location of active sources in the brain. Localizing the sources of a given scalp measurement is only achieved by solving the so-called inverse problem. By introducing reasonable a priori constraints, the inverse problem can be solved and the most probable sources in the brain at every moment in time can be accurately localized. METHODS AND RESULTS: Here, we review the different EEG source localization procedures applied during the last two decades. Additionally, we detail the importance of those procedures preceding and following source estimation that are intimately linked to a successful, reliable result. We discuss (1) the number and positioning of electrodes, (2) the varieties of inverse solution models and algorithms, (3) the integration of EEG source estimations with MRI data, (4) the integration of time and frequency in source imaging, and (5) the statistical analysis of inverse solution results. CONCLUSIONS AND SIGNIFICANCE: We show that modern EEG source imaging simultaneously details the temporal and spatial dimensions of brain activity, making it an important and affordable tool to study the properties of cerebral, neural networks in cognitive and clinical neurosciences.     

Transgenerational effects of infantile adversity and enrichment in male and female rats

To discover whether the accumulation of life's experiences, adverse and enriching, inform, and serve the following generation by inheritance we examine whether stress to a weanling female will influence her future offspring, whether prereproductive enrichment to the dam, or postweaning enrichment to the offspring, can reverse the transgenerational effects of stress, and whether, like adversity, enrichment might have transgenerational effects. Female rats were exposed to stressors when they were 27-29 days old. Half of these females and their controls were then raised in an enriched environment from weaning until mating at 60 days to examine whether preproduction enrichment reverses the effects of preproduction stress on offspring. Half of the offspring of each group were raised in an enriched environment after weaning, to see whether it reverses the effects of preproduction stress and buttresses prereproductive enrichment. Behavior was examined in 625 adult offspring in 16 groups covering all permutations of the experimental variables (preproduction weanling stress (PS), preproduction enrichment (PE), offspring enrichment (OE), sex). Exploration, avoidance learning, startle, and social interaction were tested. Results reveal that very early prereproductive experience in females, adverse or enriching, will transgenerationally influence their future offspring, depending on the behavior tested and sex. Our finding that enrichment, whether to the parent or offspring generation, can ameliorate the transgenerational impact of adversity, has novel implications for the malleability of transgenerational inheritance, and its individual, social, and therapeutic impact.     

Comparison of acute and chronic traumatic brain injury using semi-automatic multimodal segmentation of MR volumes

Although neuroimaging is essential for prompt and proper management of traumatic brain injury (TBI), there is a regrettable and acute lack of robust methods for the visualization and assessment of TBI pathophysiology, especially for of the purpose of improving clinical outcome metrics. Until now, the application of automatic segmentation algorithms to TBI in a clinical setting has remained an elusive goal because existing methods have, for the most part, been insufficiently robust to faithfully capture TBI-related changes in brain anatomy. This article introduces and illustrates the combined use of multimodal TBI segmentation and time point comparison using 3D Slicer, a widely-used software environment whose TBI data processing solutions are openly available. For three representative TBI cases, semi-automatic tissue classification and 3D model generation are performed to perform intra-patient time point comparison of TBI using multimodal volumetrics and clinical atrophy measures. Identification and quantitative assessment of extra- and intra-cortical bleeding, lesions, edema, and diffuse axonal injury are demonstrated. The proposed tools allow cross-correlation of multimodal metrics from structural imaging (e.g., structural volume, atrophy measurements) with clinical outcome variables and other potential factors predictive of recovery. In addition, the workflows described are suitable for TBI clinical practice and patient monitoring, particularly for assessing damage extent and for the measurement of neuroanatomical change over time. With knowledge of general location, extent, and degree of change, such metrics can be associated with clinical measures and subsequently used to suggest viable treatment options.     

Salmonella typhimurium disseminates within its host by manipulating the motility of infected cells

The mammalian host has a number of innate immune mechanisms designed to limit the spread of infection, yet many bacteria, including Salmonella, can cause systemic disease. Salmonella typhimurium-infected phagocytes traverse the gastrointestinal (GI) epithelium and enter the bloodstream within minutes after ingestion, thereby spreading throughout its host. Here, we provide a cellular and molecular basis for this phenomenon. We demonstrate that S. typhimurium manipulates the migratory properties of infected GI phagocytes with a type III secretion system. We show that one secreted effector, SrfH, interacts with the host protein TRIP6, a member of the zyxin family of adaptor proteins that regulate motility. SrfH promotes phagocyte motility in vitro and accelerates the systemic spread of infection away from the lumen of the intestine in the mouse. This is a previously uncharacterized mechanism by which an intracellular pathogen overcomes host defenses designed to immobilize infected cells.