Electrocardiogram alterations in non-traumatic brain injury: a systematic review.

The presence of abnormal electrocardiograms in individuals without known organic heart disease is one of the most common manifestations of cardiac dysfunction occurring during acute non traumatic brain injury. The primary goal of the present review is to provide an overview of the available data and literature regarding the presence of new-onset electrocardiographic (ECG) alterations in acute non traumatic brain injury. The secondary aim is to identify the incidence of ECG alterations and consider the prognostic significance of new-onset ECG changes in this setting. To do so, English language articles from January 2000 to January 2022 were included from PubMed using the following keywords: "electrocardiogram and subarachnoid hemorrhage", "electrocardiogram and intracranial hemorrhage", "Q-T interval and subarachnoid hemorrhage ", "Q-T interval and intracranial bleeding ", "Q-T interval and intracranial hemorrhage", and "brain and heart- interaction in stroke". Of 3162 papers, 27 original trials looking at electrocardiogram alterations in acute brain injury were included following the PRISMA guideline. ECG abnormalities associated with acute brain injury could potentially predict poor patient outcomes. They could even herald the future development of neurogenic pulmonary edema (NPE), delayed cerebral ischemia (DCI), and even in-hospital death. In particular, patients with SAH are at increased risk of having severe ventricular dysrhythmias. These may contribute to a high mortality rate and to poor functional outcome at 3 months. The current data on ECG QT dispersion and mortality appear less clearly associated. While some patients demonstrated poor outcomes, others showed no relationship with poor outcomes or increased in-hospital mortality. Observing ECG alterations carefully after cerebral damage is important in the critical care of these patients as it can expose preexisting myocardial disease and change prognosis.

Aberrant visual pathway development in albinism: From retina to cortex.

Albinism refers to a group of genetic abnormalities in melanogenesis that are associated neuronal misrouting through the optic chiasm. We perform quantitative assessment of visual pathway structure and function in 23 persons with albinism (PWA) and 20 matched controls using optical coherence tomography (OCT), volumetric magnetic resonance imaging (MRI), diffusion tensor imaging and visual evoked potentials (VEP). PWA had a higher streamline decussation index (percentage of total tractography streamlines decussating at the chiasm) compared with controls (Z = -2.24, p = .025), and streamline decussation index correlated weakly with inter-hemispheric asymmetry measured using VEP (r = .484, p = .042). For PWA, a significant correlation was found between foveal development index and total number of streamlines (r = .662, p < .001). Significant positive correlations were found between peri-papillary retinal nerve fibre layer thickness and optic nerve (r = .642, p < .001) and tract (r = .663, p < .001) width. Occipital pole cortical thickness was 6.88% higher (Z = -4.10, p < .001) in PWA and was related to anterior visual pathway structures including foveal retinal pigment epithelium complex thickness (r = -.579, p = .005), optic disc (r = .478, p = .021) and rim areas (r = .597, p = .003). We were unable to demonstrate a significant relationship between OCT-derived foveal or optic nerve measures and MRI-derived chiasm size or streamline decussation index. Our novel tractographic demonstration of altered chiasmatic decussation in PWA corresponds to VEP measured cortical asymmetry and is consistent with chiasmatic misrouting in albinism. We also demonstrate a significant relationship between retinal pigment epithelium and visual cortex thickness indicating that retinal pigmentation defects in albinism lead to downstream structural reorganisation of the visual cortex.

Voices of the Filipino Community Describing the Importance of Family in Understanding Adolescent Behavioral Health Needs.

Filipinos are a large, yet invisible, minority at high risk for adolescent behavioral health problems. Limited research describes the family as offering a source of positive support for some Filipino youths and yet for some it is also a source of stress and isolation, leading to struggles with adolescent depression and suicidal behavior. This article describes a qualitative study that investigates the role of family when understanding behavioral health needs among Filipino adolescents. Findings highlight the importance of addressing family cohesion when designing interventions aimed at improving the well-being of Filipino youth.

Ecallantide for the acute treatment of angiotensin-converting enzyme inhibitor-induced angioedema: a multicenter, randomized, controlled trial.

STUDY OBJECTIVE: We compare the safety and efficacy of ecallantide with placebo in subjects undergoing assessment for acute angiotensin-converting enzyme inhibitor-induced angioedema (ACEIA) in an emergency department (ED). METHODS: This was a multicenter, phase 2, double-blind study with subjects randomized to receive a single subcutaneous dose of ecallantide (10, 30, or 60 mg) or placebo plus physician-directed conventional therapy. The primary endpoint was defined as meeting predetermined discharge eligibility criteria within 6 hours of study drug administration. Discharge criteria included improvement of edema, stable vital signs, absence of stridor, absence of dyspnea or use of accessory muscles during respiration, absence of drooling, and ability to drink without difficulty. RESULTS: An interim analysis showed that a high percentage of subjects met the primary endpoint, and the study was halted. Overall, 79 subjects were randomized and 76 had data for analysis. Most had mild (45%) or moderate (42%) ACEIA. The discharge eligibility endpoint was met by 72% of the placebo group and 85%, 89%, and 89% of the ecallantide 10-, 30-, and 60-mg groups, respectively. This difference in meeting discharge eligibility endpoint criteria between treatment groups was not statistically significant. The incidence of treatment-emergent adverse events was similar between placebo and active-treatment groups. CONCLUSION: The addition of ecallantide to standard therapy does not appear to improve angioedema compared with placebo in ED patients with ACEIA. Our data suggest that most ED patients presenting with mild to moderate ACEIA are likely to meet our discharge eligibility criteria within 6 hours of treatment, regardless of intervention. Further studies to assess the utility of ecallantide in patients with more severe angioedema may be useful. No new safety signals related to ecallantide administration were identified.

Electroencephalographic monitoring of brain activity during cardiac arrest: a narrative review.

BACKGROUND: To date cardiac arrest (CA) remains a frequent cause of morbidity and mortality: despite advances in cardiopulmonary resuscitation (CPR), survival is still burdened by hypoxic-ischemic brain injury (HIBI), and poor neurological outcome, eventually leading to withdrawal of life sustaining treatment (WLST). The aim of CPR is cardiac pump support to preserve organ perfusion, until normal cardiac function is restored. However, clinical parameters of target organ end-perfusion during CPR, particularly brain perfusion, are still to be identified. In this context, electroencephalography (EEG) and its derivatives, such as processed EEG, could be used to assess brain function during CA. OBJECTIVES: We aimed to review literature regarding the feasibility of EEG and processed or raw EEG monitoring during CPR. METHODS: A review of the available literature was performed and consisted of mostly case reports and observational studies in both humans and animals, for a total number of 22 relevant studies. RESULTS: The research strategy identified 22 unique articles. 4 observational studies were included and 6 animal testing studies in swine models. The remaining studies were case reports. Literature regarding this topic consists of conflicting results, containing studies where the feasibility of EEG during CPR was positive, and others where the authors reached opposite conclusions. Furthermore, the level of evidence, in general, remains low. DISCUSSION: EEG may represent a useful tool to assess CPR effectiveness. A multimodal approach including other non-invasive tools such as, quantitative infrared pupillometry and transcranial Doppler, could help to optimize the quality of resuscitation maneuvers.

Longitudinal Patterns of Cortical Atrophy on MRI in Patients With Alzheimer Disease With and Without Lewy Body Pathology.

BACKGROUND AND OBJECTIVES: Although Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) represent two different pathologies, they have clinical overlap, and there is a significant degree of co-occurrence of their neuropathological findings. Many studies have examined imaging characteristics in clinically diagnosed patients; however, there is a relative lack of longitudinal studies that have studied patients with pathological confirmation. We examined whether there were differences in longitudinal patterns of cortical atrophy between patients with both AD and DLB (AD/DLB) vs. those with AD alone. METHODS: We collected and analyzed clinical and neuroimaging data from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database for patients who underwent autopsy. The rates of change in various neuropsychological assessments were not significantly different between AD/DLB and AD patients, and each group had neuropsychological outcomes consistent with disease progression. For our neuroimaging analysis, we used a linear mixed effects model to examine if there were longitudinal differences in cortical rates of atrophy between AD/DLB and AD patients. RESULTS: Autopsies and serial neuroimaging was available on 48 patients (24 AD, 24 AD/DLB). Patients with AD alone had significantly higher atrophy rates in the left cuneus, lateral occipital, and parahippocampal regions over time when compared to patients with concomitant DLB, after covarying for interval from imaging to autopsy, gender, and total estimated intracranial volume (eTIV). Site ID was included as a random effect to account for site differences. For these regions, the rate of decline over time in the AD/DLB group were less steep by a difference of 0.1887, 0.395, and 0.0989, respectively (p =.022, .006, and .006). The lattermost left cuneus volume measurement also positively correlated to Braak Lewy score (Pearson's product-moment correlation 0.37, p=.009), while the lattermost left parahippocampal volume measurement negatively correlated to Braak NFT score (Pearson's product-moment correlation -0.327, p=.02). DISCUSSION: AD patients had more significant atrophy in the left cuneus, lateral occipital, and parahippocampal regions when compared to AD/DLB patients. These regions are known to distinguish DLB and AD pathology cross-sectionally, but here are shown to distinguish longitudinal disease progression.

Data to inform counseling on parathyroidectomy for secondary hyperparathyroidism of renal origin.

BACKGROUND: The risk of postoperative hungry bone syndrome after parathyroidectomy for secondary hyperparathyroidism of renal origin may alter the course of treatment, including the hospital length of stay and readmission rates. We sought to identify additional patient or hospital factors that might contribute to hungry bone syndrome after parathyroidectomy in patients with secondary hyperparathyroidism of renal origin. METHODS: Patients who underwent a parathyroidectomy for secondary hyperparathyroidism of renal origin were identified in a geographically diverse, 10-state, discharge data set. Covariates included demographic data, payer status, 31 comorbidities, and hospital characteristics. The primary outcome variable of interest was hospital length of stay. Secondary outcomes were complications and 30-day readmission. RESULTS: Of 796 patients studied, 164 patients (20.6%) were diagnosed with hungry bone syndrome. There were no differences in the rates of hungry bone syndrome by race or number of comorbidities. The average age of hungry bone syndrome patients (45.7 years ± 13.9) was younger than that of non-hungry bone syndrome patients (50.7 ± 14.8; P < .001). Hungry bone syndrome was more common among obese patients than nonobese patients (25.0% vs 15.8%; P < .001). Parathyroid autotransplant was performed at similar rates in hungry bone syndrome and non-hungry bone syndrome patients (23.8% vs 23.1%; P = .821). Median length of stay was significantly longer for hungry bone syndrome patients (6 days, interquartile range: [4, 8] versus 3 days, interquartile range: [2-6]; P < .001). Similar 30-day readmission rates were observed (hungry bone syndrome: 41 (25%) versus non-hungry bone syndrome: 147 (23%); P = .640). CONCLUSION: Hungry bone syndrome occurs in 1 of 5 patients after parathyroidectomy for secondary hyperparathyroidism of renal origin. Patients should be informed of the possibility of a relatively long (6 days) length of stay after surgery as well as the moderate possibility (>20%) of another hospitalization within the 30-day postdischarge period.

Excessive Sedation as a Risk Factor for Delirium: A Comparison between Two Cohorts of ARDS Critically Ill Patients with and without COVID-19.

Excessive sedation is associated with poor outcome in critically ill acute respiratory distress syndrome (ARDS) patients. Whether this prognostic effect varies among ARDS patients with and without COVID-19 has yet to be determined. We compared the prognostic value of excessive sedation­in terms of delirium, length of stay in intensive care unit (ICU-LOS) and ICU mortality­between COVID-19 and non-COVID-19 critically ill ARDS patients. This was a second analysis of prospectively collected data in four European academic centers pertaining to 101 adult critically ill ARDS patients with and without COVID-19 disease. Depth of sedation (DOS) and delirium were monitored through processed electroencephalogram (EEG) and the Confusion Assessment Method for ICU (CAM-ICU). Our main exposure was excessive sedation and how it relates to the presence of delirium, ICU-LOS and ICU mortality. The criterion for excessive sedation was met in 73 (72.3%) patients; of these, 15 (82.2%) and 58 (69.1%) were in non-COVID-19 and COVID-19 ARDS groups, respectively. The criteria of delirium were met in 44 patients (60.3%). Moreover, excessive sedation was present in 38 (86.4%) patients with delirium (p < 0.001). ICU death was ascertained in 41 out of 101 (41.0%) patients; of these, 37 (90.2%) had excessive sedation (p < 0.001). The distribution of ICU-LOS among excessive-sedated and non-sedated patients was 22 (16−27) vs. 14 (10.5−19.5) days (p < 0.001), respectively. In a multivariable framework, excessive sedation was independently associated with the development of delirium (p = 0.001), increased ICU mortality (p = 0.009) and longer ICU-LOS (p = 0.000), but only in COVID-19 ARDS patients. Independent of age and gender, excessive sedation might represent a risk factor for delirium in COVID-19 ARDS patients. Similarly, excessive sedation shows to be an independent predictor of ICU-LOS and ICU mortality. The use of continuous EEG-based depth of sedation (DOS) monitoring and delirium assessment in critically ill COVID-19 patients is warranted.

A Novel MEMS Capacitive Microphone with Semiconstrained Diaphragm Supported with Center and Peripheral Backplate Protrusions.

Audio applications such as mobile phones, hearing aids, true wireless stereo earphones, and Internet of Things devices demand small size, high performance, and reduced cost. Microelectromechanical system (MEMS) capacitive microphones fulfill these requirements with improved reliability and specifications related to sensitivity, signal-to-noise ratio (SNR), distortion, and dynamic range when compared to their electret condenser microphone counterparts. We present the design and modeling of a semiconstrained polysilicon diaphragm with flexible springs that are simply supported under bias voltage with a center and eight peripheral protrusions extending from the backplate. The flexible springs attached to the diaphragm reduce the residual film stress effect more effectively compared to constrained diaphragms. The center and peripheral protrusions from the backplate further increase the effective area, linearity, and sensitivity of the diaphragm when the diaphragm engages with these protrusions under an applied bias voltage. Finite element modeling approaches have been implemented to estimate deflection, compliance, and resonance. We report an 85% increase in the effective area of the diaphragm in this configuration with respect to a constrained diaphragm and a 48% increase with respect to a simply supported diaphragm without the center protrusion. Under the applied bias, the effective area further increases by an additional 15% as compared to the unbiased diaphragm effective area. A lumped element model has been also developed to predict the mechanical and electrical behavior of the microphone. With an applied bias, the microphone has a sensitivity of -38 dB (ref. 1 V/Pa at 1 kHz) and an SNR of 67 dBA measured in a 3.25 mm × 1.9 mm × 0.9 mm package including an analog ASIC.

Synthesis and SAR of vinca alkaloid analogues.

Versatile intermediates 12'-iodovinblastine, 12'-iodovincristine and 11'-iodovinorelbine were utilized as substrates for transition metal based chemistry which led to the preparation of novel analogues of the vinca alkaloids. The synthesis of key iodo intermediates, their transformation into final products, and the SAR based upon HeLa and MCF-7 cell toxicity assays is presented. Selected analogues 27 and 36 show promising anticancer activity in the P388 murine leukemia model.

BPA Alters Estrogen Receptor Expression in the Heart After Viral Infection Activating Cardiac Mast Cells and T Cells Leading to Perimyocarditis and Fibrosis.

Myocarditis is an inflammatory heart disease that leads to dilated cardiomyopathy (DCM) and heart failure. Sex hormones play an important role in the development of myocarditis with testosterone driving disease in males and estrogen being cardioprotective in females. The human population is widely exposed to the endocrine disruptor bisphenol A (BPA) from plastics such as water bottles, plastic food containers, copy paper, and receipts. Several clinical and numerous animal studies have found an association between elevated BPA levels and cardiovascular disease. A recent report found elevated levels of BPA in the serum of patients with DCM compared to healthy controls. In this study we examined whether exposure to BPA for 2 weeks prior to viral infection and leading up to myocarditis at day 10 altered inflammation in female BALB/c mice housed in standard plastic cages/water bottles with soy-free food and bedding. We found that a human relevant dose of BPA (25 µg/L) in drinking water, with an estimated exposure of 5 µg BPA/kg BW, significantly increased myocarditis and pericarditis compared to control water without altering viral genome levels in the heart. BPA exposure activated ERα and ERß in the spleen 24 h after infection and phosphorylated ERα and ERß during myocarditis, but decreased ERα and increased ERß mRNA in the heart as measured by qRT-PCR. Exposure to BPA significantly increased CD4+ T cells, IFNγ, IL-17A, TLR4, caspase-1, and IL-1ß in the heart. BPA exposure also increased cardiac fibrosis compared to controls. Mast cells, which are associated with cardiac remodeling, were found to increase in number and degranulation, particularly along the pericardium. Interestingly, plastic caging/water bottle exposure alone led to increased mast cell numbers, pericardial degranulation and fibrosis in female BALB/c mice compared to animals housed in glass cages/water bottles with soy-free food and bedding. These data suggest that BPA exposure may increase the risk of developing myocarditis after a viral infection in women.

Are you Ernest Shackleton, the polar explorer? Refining the criteria for delirium and brain dysfunction in sepsis.

The Third International Consensus Definitions for Sepsis and Septic Shock has recently defined sepsis as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Organ dysfunctions in this consensus definition were identified as an organ-specific Sequential [Sepsis-related] Organ Failure Assessment (SOFA) score ≥ 2 points. The quick SOFA (qSOFA) considers altered mentation indicating brain dysfunction when the Glasgow Coma Scale (GCS) score is ≤13 or ≤14. However, concern has been expressed that the revised criteria may lead to a failure in recognizing the signs of potentially lethal organ dysfunction and thus sepsis. Patients with delirium have a fluctuating course, and GCS can be normal or only slightly reduced at the time when signs of delirium are already present. We here report an illustrative case showing how an acute, initially unrecognized, urinary tract infection caused acute brain dysfunction with profound behavioral and cognitive dysfunction despite normal GCS, hence not meeting the criteria for sepsis.

Ketamine: A Cause of Urinary Tract Dysfunction.

Drug addiction as a result of improper use of prescribed and illicit use has been on the increase globally. The effects of such use have implications in the urologic disease space. To this end, Ketamine has been reported to affect urologic function, causing a number of voiding symptoms. It may also confound the differential diagnosis of urologic diseases, such as interstitial cystitis, among others.

Characterization of Abnormal Optic Nerve Head Morphology in Albinism Using Optical Coherence Tomography.

PURPOSE: To characterize abnormalities in three-dimensional optic nerve head (ONH) morphology in people with albinism (PWA) using spectral-domain optical coherence tomography (SD-OCT) and to determine whether ONH abnormalities relate to other retinal and clinical abnormalities. METHODS: Spectral-domain OCT was used to obtain three-dimensional images from 56 PWA and 60 age- and sex-matched control subjects. B-scans were corrected for nystagmus-associated motion artefacts. Disc, cup, and rim ONH dimensions and peripapillary retinal nerve fiber layer (ppRNFL) thickness were calculated using Copernicus and ImageJ software. RESULTS: Median disc areas were similar in PWA (median = 1.65 mm2) and controls (1.71 mm2, P = 0.128), although discs were significantly elongated horizontally in PWA (P < 0.001). In contrast, median optic cup area in PWA (0.088 mm2) was 23.7% of that in controls (0.373 mm2, P < 0.001), with 39.4% of eyes in PWA not demonstrating a measurable optic cup. This led to significantly smaller cup to disc ratios in PWA (P < 0.001). Median rim volume in PWA (0.273 mm3) was 136.6% of that in controls (0.200 mm3). The ppRNFL was significantly thinner in PWA compared with controls (P < 0.001), especially in the temporal quadrant. In PWA, ppRNFL thickness was correlated to ganglion cell thickness at the central fovea (P = 0.007). Several ONH abnormalities, such as cup to disc ratio, were related to higher refractive errors in PWA. CONCLUSIONS: In PWA, ocular maldevelopment is not just limited to the retina but also involves the ONH. Reduced ppRNFL thickness is consistent with previous reports of reduced ganglion cell numbers in PWA. The thicker rim volumes may be a result of incomplete maturation of the ONH.

Survey of cattle in northeast Colorado for evidence of chronic wasting disease: geographical and high-risk targeted sample.

A geographically targeted survey of potentially high-risk, adult cattle in chronic wasting disease (CWD)-endemic areas in Colorado was initiated to assess the possibility of the spread of CWD from deer to cattle under natural conditions. Surveyed cattle were sympatric with free-roaming deer in geographically defined areas where CWD occurs and where CWD prevalence has been estimated. To qualify for inclusion in the survey, cattle had to be at least 4 years old and had to have spent a minimum of 4 years in surveyed areas. Brains from culled cattle were examined microscopically and immunohistochemically for tissue alterations indicative of a transmissible spongiform encephalopathy (TSE). Two hundred sixty-two brains were suitable for evaluation and were found to lack changes indicative of a TSE infection. Prion deposition was not demonstrable using a method involving formic acid and proteinase-K treatment before application of monoclonal antibody to bovine prion protein (F99/97.6.1). Some incidental neuropathologic changes unrelated to those of TSEs were detected. Findings from this study suggest that large-scale spread of CWD from deer to cattle under natural range conditions in CWD-endemic areas of northeast Colorado is unlikely.

Papillary Renal Carcinoma Presenting as a Cancer of Unknown Primary (CUP) and Diagnosed through Gene Expression Profiling.

Cancer of unknown primary (CUP) is a clinical syndrome representing many types of cancers and diagnoses are typically made after review of clinical presentation, pathology (including immunohistochemical staining) and imaging studies. Treatment with systemic chemotherapy has been shown to result in fairly reproducible objective response rates. Herein, a case of a patient who was initially diagnosed with a poorly differentiated adenocarcinoma of unknown origin is reported. After mRNA gene expression profiling (commercially available CancerTYPE ID), a specific diagnosis of papillary renal cell carcinoma (RCC) was made and then confirmed with additional immunohistochemical staining. The patient was treated with targeted therapy and an objective radiographic response was seen. A literature review suggests this to be the first patient with papillary RCC, identified by molecular profiling, and benefitting from a targeted agent that otherwise would not have been considered in the setting of CUP. This case underscores the importance of considering the use of newer testing technologies in the interest of offering patients more specific, targeted therapy in order to improve efficacy and spare patients toxicities of less specific, empiric chemotherapeutic regimens.

Are optimal cerebral perfusion pressure and cerebrovascular autoregulation related to long-term outcome in patients with aneurysmal subarachnoid hemorrhage?

BACKGROUND AND OBJECTIVES: Continuous assessment of the cerebrovascular autoregulation (CVA) through use of the pressure reactivity index (PRx), a moving linear correlation coefficient between mean arterial blood pressure and intracranial pressure, has been effective in optimizing cerebral perfusion pressure (CPPopt) in traumatic brain injured (TBI) patients. This study investigates the feasibility of measuring CPPopt in patients with aneurysmal subarachnoid hemorrhage (aSAH) by continuously assessing the CVA. METHODS: Twenty-nine aSAH patients were enrolled, and data from CVA status, CPPopt, and periods when CPP was below, within, or above CPPopt were computed daily. Outcome was assessed at 6 months with the Glasgow Outcome Scale. Mann-Whitney U test was used to analyze differences in the duration of impaired CVA and duration of CPP below CPPopt in patients with good and poor outcomes. Multivariable logistic regression analysis was used to identify independent predictors of outcome. RESULTS: CVA monitoring data were available for all 29 patients with a total monitoring time of 2757 h. The duration of impaired CVA was 36.5% (interquartile range: 24.6 to 49.8) of the total monitoring time in 15 patients with good outcome and 71.6% of the total monitoring time (51.2 to 80.0) in 14 patients with poor outcome (Mann-Whitney U test 3.295, P=0.0010). PRx-based CPPopt could be identified in 26 patients (89.6%) with a total monitoring time of 2691 h. The duration of CPP below the CPPopt range was 28.0% (interquartile range: 18.0 to 47.0) of the total monitoring time in patients with good outcome and 76.0% (48.5 to 82.5) in patients with poor outcome (Mann-Whitney U test 2.779, P=0.0054). Glasgow Coma Scale score and duration of impaired CVA were independently associated with 6-month outcome (Glasgow Coma Scale score odds ratio: 1.95, 95% confidence interval: 1.01-3.75; duration of impaired CVA odds ratio: 0.88, 95% confidence interval: 0.78-0.99). CONCLUSIONS: The assessment of CVA and CPPopt is feasible in aSAH patients and may provide important information regarding long-term outcome. A PRx above the 0.2 threshold and a CPP below the CPPopt range are associated with worse outcome.

F-18 FDG PET imaging of chronic traumatic brain injury in boxers: a statistical parametric analysis.

PURPOSE: The participation in concussive susceptible sports such as boxing may cause chronic traumatic brain injury. The objective of this study was to determine whether there are unique patterns of reduced brain glucose metabolism in professional and amateur boxers. METHOD: We compared the fluorine-18 fluorodeoxyglucose (F-18 FDG) PET brain scans of boxers (group) (N=19) with those of controls (group) (N=7) using both statistical parametric mapping and region of interest analysis. RESULTS: Boxers showed decreased F-18 FDG uptake by 8-15% in the following brain areas: posterior cingulate cortex, parieto-occipito, frontal lobes (Broca's area) bilaterally, and the cerebellum (P<0.005) as compared with controls. CONCLUSION: Our results suggest that F-18 FDG PET scans of boxers suspected of chronic traumatic brain injury show unique patterns of hypometabolism, and that these patterns may reflect the mechanisms of repeated traumatic brain injury unique to boxers.

A biomechanical comparison of two volar locked plates in a dorsally unstable distal radius fracture model.

BACKGROUND: This study compares the biomechanical stability of two volar locked plate systems for fixation of unstable, extra-articular distal radius fractures. METHODS: In six matched pairs of fresh frozen cadaveric specimens, a simulated unstable, extra-articular distal radius fracture was created. The fractures were stabilized with one of two types of volar locked plates. Specimens were axially loaded at five different positions: central, volar, dorsal, radial, and ulnar. Initial (precyclic loading) stiffness of each locked plate system was calculated. Each specimen was then loaded for 5,000 cycles with an 80 N central load. Finally, specimens were axially loaded at the same five positions to calculate the postcyclic loading stiffness of each volar locked plate system. Main outcome measurements were precyclic loading stiffness, postcyclic loading stiffness, maintenance of stiffness after cyclic loading, and amount of fracture displacement between the two volar locked plate systems. RESULTS: There were no differences in maintenance of stiffness and fracture displacement following cyclical loading between the two volar plate systems. After cyclic loading, the distal volar radius (DVR) locked plate was significantly stiffer than the Synthes volar locked plate in volar loading only (p < 0.01). CONCLUSION: Materials properties and design differences between these systems did not provide enough biomechanical difference to support use of either implant over the other. With this in vitro model, both implants provided adequate stability to resist physiologic loads expected during therapy in the initial postoperative period.

Old mice express a transient early resistance to pulmonary tuberculosis that is mediated by CD8 T cells.

During the natural aging process the immune system undergoes many alterations. In particular, both the CD4 and CD8 T-cell compartments become compromised, and these changes have serious implications for the capacity of the elderly to control infection. As a result, the elderly are more susceptible to many infectious diseases, including primary infection and reactivation of latent infections. In this study we addressed the capacity of old mice to control an infection with Mycobacterium tuberculosis and to characterize the mechanism by which old mice, paradoxically, can express a transient early resistance to infection. This resistance was shown to be associated with the presence of CD8 T cells within the lungs that were capable of secreting gamma interferon, as illustrated by the demonstration that early resistance was lost in aged CD8 gene-disrupted mice. These studies therefore show that, despite a documented decline in general CD8 T-cell responsiveness in the elderly, a subset of CD8 T cells is an important early mediator of protection in the lungs of old mice that have been infected with M. tuberculosis.