CX3CR1-dependent subretinal microglia cell accumulation is associated with cardinal features of age-related macular degeneration

The role of retinal microglial cells (MCs) in age-related macular degeneration (AMD) is unclear. Here we demonstrated that all retinal MCs express CX3C chemokine receptor 1 (CX3CR1) and that homozygosity for the CX3CR1 M280 allele, which is associated with impaired cell migration, increases the risk of AMD. In humans with AMD, MCs accumulated in the subretinal space at sites of retinal degeneration and choroidal neovascularization (CNV). In CX3CR1-deficient mice, MCs accumulated subretinally with age and albino background and after laser impact preceding retinal degeneration. Raising the albino mice in the dark prevented both events. The appearance of lipid-bloated subretinal MCs was drusen-like on funduscopy of senescent mice, and CX3CR1-dependent MC accumulation was associated with an exacerbation of experimental CNV. These results show that CX3CR1-dependent accumulation of subretinal MCs evokes cardinal features of AMD. These findings reveal what we believe to be a novel pathogenic process with important implications for the development of new therapies for AMD.     

Predictors of a positive response to biventricular pacing in patients with severe heart failure and ventricular conduction delay

BACKGROUND: Cardiac resynchronization therapy (CRT) is recommended in patients with ejection fraction <35%, QRS width> 120 ms, and New York Heart Association (NYHA) functional class III or IV despite optimal medical therapy. We aimed to define demographic, clinical, and electrocardiographic predictors of positive clinical response to CRT. METHODS AND RESULTS: Hundred consecutive patients fulfilling the recommended criteria were implanted with a CRT device. Demographic, clinical, two-dimensional echocardiographic and electrographic parameters were measured at baseline and after 6 months of simultaneous biventricular pacing. A positive response to CRT included an improvement of at least one NYHA functional class associated with an absence of hospitalization for worsening heart failure. At the end of follow-up, 12 patients were dead and 71% of the patients were classified as responders. After 6 months of CRT, the ejection fraction was significantly higher (P = 0.035) in responders versus nonresponders. Multivariate analysis identified three independent predictors of positive response to CRT: an idiopathic origin of the cardiomyopathy (P = 0.043), a wider QRS before implantation (P = 0.017), and a narrowing of the QRS after implantation (P = 0.037). CONCLUSION: An idiopathic origin of the cardiomyopathy, a wider QRS before implantation, and a narrowing of the QRS width after implantation were identified as independent predictors of clinical positive response to CRT.     

The ability of the Biodex Stability System to distinguish level of function in subjects with a second-degree ankle sprain

OBJECTIVE: To assess the capacity of the Biodex Stability System using a one-leg stance protocol to differentiate between injured and non-injured limbs and between level of disabilities. DESIGN: Cross-sectional study. SETTING: Military and civilian clinic. SUBJECTS: Thirty-four individuals with a second-degree lateral ankle sprain and 36 healthy subjects. METHODS AND MEASURES: Subjects were tested on the Stability System 30 days after injury using a one-leg stance protocol in the dynamic limit-of-stability mode. All subjects also filled out a disability questionnaire (Lower Extremity Functional Scale). The groups were compared based on the overall dynamic limit-of-stability score and its relationship with the score on the disability questionnaire was also examined. RESULTS: The overall dynamic limit-of-stability scores (subjects with a lateral ankle sprain: 13.0% (5.5)-26.0% (9.2); healthy subjects: 16.9% (7.9)-27.9% (9.6)) clustered in the lower end of the theoretical range of 0-100%. Statistically significant differences in the overall dynamic limit-of-stability scores were found between the injured and non-injured limbs but group differences were small and clinically not relevant. No significant relationships were found between the overall dynamic limit-of-stability scores and the Lower Extremity Functional Scale scores (58.2 (11.8)) of the subjects with a lateral ankle sprain. CONCLUSIONS: The one-leg stance protocol carried out in the dynamic limit-of-stability mode is very challenging and offers a very limited capacity to differentiate between injured and non-injured limbs. The main outcome of the Stability System does not appear to be a good indicator of the functional capacity of people with a lateral ankle sprain.     

Regulation of natural cytotoxicity by the adaptor SAP and the Src-related kinase Fyn

SAP is an adaptor protein that is expressed in NK and T cells. It is mutated in humans who have X-linked lymphoproliferative (XLP) disease. By interacting with SLAM family receptors, SAP enables tyrosine phosphorylation signaling of these receptors by its ability to recruit the Src-related kinase, Fyn. Here, we analyzed the role of SAP in NK cell functions using the SAP-deficient mouse model. Our results showed that SAP was required for the ability of NK cells to eliminate tumor cells in vitro and in vivo. This effect strongly correlated with expression of CD48 on tumor cells, the ligand of 2B4, a SLAM-related receptor expressed in NK cells. In keeping with earlier reports that studied human NK cells, we showed that SAP was necessary for the ability of 2B4 to trigger cytotoxicity and IFN-gamma secretion. In the absence of SAP, 2B4 function was shifted toward inhibition of NK cell-mediated cytotoxicity. By analyzing mice lacking Fyn, we showed that similarly to SAP, Fyn was strictly required for 2B4 function. Taken together, these results provide evidence that the 2B4-SAP-Fyn cascade defines a potent activating pathway of natural cytotoxicity. They also could help to explain the high propensity of patients who have XLP disease to develop lymphoproliferative disorders.     

Sensitive HPLC-fluorescence method for irinotecan and four major metabolites in human plasma and saliva: application to pharmacokinetic studies

BACKGROUND: We developed gradient HPLC methods for quantification of the antimitotic drug irinotecan (CPT-11) and its four metabolites, SN-38, SN-38 G, 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]-carbonyloxycamptothecin (APC), and 7-ethyl-10-[4amino-1-piperidino]-carbonyloxycamptothecin (NPC), as the sum of the lactone and carboxylate forms, in human plasma and saliva. Camptothecin was used as internal standard. METHODS: The sample pretreatment involved protein precipitation with methanol-acetonitrile (50:50 by volume) followed by acidification with hydrochloric acid to convert the lactone ring-opened form into its lactone form, quantitatively. HPLC separation was performed on a Xterra RP18 column. The excitation wavelength was 370 nm, and the emission wavelength was set at 470 nm for the first 24 min and then at 534 nm for the next 4 min. The stabilities of irinotecan and its four metabolites in plasma, saliva, and acidic extracts were also investigated under various conditions. RESULTS: Assays were linear in the tested range of 0.5-1000 micro g/L. For the five analytes, limits of quantification were 0.5 micro g/L in both matrices. The interassay imprecision (as relative standard deviation) was 3.2-14% in plasma and 2.6-5.6% in saliva. Assay recoveries ranged from 92.8% to 111.2% for plasma and 100.1% to 104.1% for saliva. Mean extraction recovery from plasma or saliva was 90%. CONCLUSION: The developed assay can be used to determine pharmacokinetic parameters for CPT-11, SN-38, SN-38 G, APC, and NPC in plasma and saliva from patients with metastatic colorectal cancer.     

Temporary and definitive external fixation of war injuries: use of a French dedicated fixator

Purpose

External fixation is the recommended stabilization method for both open and closed fractures of long bones in forward surgical hospitals. Specific combat surgical tactics are best performed using dedicated external fixators. The Percy Fx© (Biomet) fixator was developed for this reason by the French Army Medical Service, and has been used in various theatres of operations for more than ten years.

Methods

The tactics of Percy Fx© (Biomet) fixator use were analysed in two different situations: for the treatment of French soldiers wounded on several battlefields and then evacuated to France and for the management of local nationals in forward medical treatment facilities in Afghanistan and Chad.

Results

Overall 48 externals fixators were implanted on 37 French casualties; 28 frames were temporary and converted to definitive rigid frames or internal fixation after medical evacuation. The 77 Afghan patients totalled 85 external fixators, including 13 temporary frames applied in Forward Surgical Teams (FSTs) prior to their arrival at the Kabul combat support hospital. All of the 47 Chadian patients were treated in a FST with primary definitive frames because of delayed surgical management and absence of higher level of care in Chad.

Conclusion

Temporary frames were mostly used for French soldiers to facilitate strategic air medical evacuation following trauma damage control orthopaedic principles. Definitive rigid frames permitted achieving treatment of all types of war extremity injuries, even in poor conditions.     

Detection of specific chromosomal aberrations in urine using BCA-1 (oligo-CGH-array) enhances diagnostic sensitivity and predicts the aggressiveness of non-muscle-invasive bladder transitional cell carcinoma

Introduction

Bladder carcinoma (B-TCC) is the fifth most prevalent carcinoma in the United States (US) or Europe. In addition, B-TCC is the most expensive carcinoma per patient between diagnosis and death, because of its 50–80 % recurrence rate. B-TCC is an optimal carcinoma for which to detect DNA alterations in urine, which is easily obtainable. Chromosomal aberrations in tumors have been closely related to the carcinogenesis process.

Material and Methods

We developed a highly specific and sensitive oligo-CGH-array for the diagnosis and follow-up of B-TCC, based on the detection of chromosomal aberrations in urine samples. One hundred and sixty-four urine samples were analyzed. The qualitative results, including chromosomal aberrations, were obtained. Quantitative results are expressed as a percentage of chromosomal alterations on the autosomes.

Results

From the urine samples, we were able to differentiate B-TCC from non-malignant conditions with an accuracy of 100 % for patients without history of B-TCC. For follow-up of B-TCC in clinical practice, at least a deletion (8p; 9p; 9q) or a cut-off of >2 % of chromosomal imbalance was considered as a positive test. According to our criteria, 100 % of high-grade tumors were diagnosed, and the sensitivity to predict positive cystoscopy was 95 % (specificity 73 %). A cut-off >9 % was a strong signature of high-grade TCC (odds ratio 53 CI 95 % 7–417; p = 0.0002).

Conclusion

We developed a sensitive clinical tool for the detection of B-TCC using DNA extracted from patient urine. This tool is also able to identify low-grade B-TCC and identify high-risk patients harboring a high-grade disease.     

Transfer of learning and patient outcome in simulated crisis resource management: a systematic review

Purpose

Simulation-based learning is increasingly used by healthcare professionals as a safe method to learn and practice non-technical skills, such as communication and leadership, required for effective crisis resource management (CRM). This systematic review was conducted to gain a better understanding of the impact of simulation-based CRM teaching on transfer of learning to the workplace and subsequent changes in patient outcomes.

Source

Studies on CRM, crisis management, crew resource management, teamwork, and simulation published up to September 2012 were searched in MEDLINE^®, EMBASE?, CINAHL, Cochrane Central Register of Controlled Trials, and ERIC. All studies that used simulation-based CRM teaching with outcomes measured at Kirkpatrick Level 3 (transfer of learning to the workplace) or 4 (patient outcome) were included. Studies measuring only learners’ reactions or simple learning (Kirkpatrick Level 1 or 2, respectively) were excluded. Two authors independently reviewed all identified titles and abstracts for eligibility.

Principal findings

Nine articles were identified as meeting the inclusion criteria. Four studies measured transfer of simulation-based CRM learning into the clinical setting (Kirkpatrick Level 3). In three of these studies, simulation-enhanced CRM training was found significantly more effective than no intervention or didactic teaching. Five studies measured patient outcomes (Kirkpatrick Level 4). Only one of these studies found that simulation-based CRM training made a clearly significant impact on patient mortality.

Conclusions

Based on a small number of studies, this systematic review found that CRM skills learned at the simulation centre are transferred to clinical settings, and the acquired CRM skills may translate to improved patient outcomes, including a decrease in mortality.     

Unilateral posterior cervical spinal cord infarction due to spontaneous vertebral artery dissection

Context

Ischemia of the cervical spinal cord is a rare complication of spontaneous vertebral artery dissection (VAD) and usually involves the ventral portion. We describe a less evocative clinical presentation and images of unilateral posterior spinal cord infarction due to spontaneous VAD in order to facilitate early diagnosis.

Findings

A previously fit 30-year-old man presented with persistent headaches and proximal motor deficit of the right arm. He was diagnosed with spontaneous dissection of both vertebral arteries, with occlusion of the right one, and the right carotid artery. Neurological examination also revealed a right C2–C3 tactile sensory loss, with unilateral proprioceptive deficit below. Brain images revealed small bilateral cerebellar infarcts which could not be responsible for the clinical symptoms. Magnetic resonance imaging of the spinal cord showed a right posterior cervical spinal cord infarction. The patient achieved nearly complete recovery after several weeks of anticoagulation and rehabilitation.

Conclusion and clinical relevance

Infarction of the caudal portion of the cervical spinal cord, especially unilateral, caused by spontaneous VAD, has rarely been described and is certainly under-diagnosed due to less suggestive symptoms, like unilateral and mainly sensory deficit. Nevertheless, early diagnosis of this condition is important to guide patient management and rehabilitation.     

Estimating Endogenous Dopamine Levels at D2 and D3 Receptors in Humans using the Agonist Radiotracer [11C]-(+)-PHNO

Using positron emission tomography (PET) and an acute dopamine depletion challenge it is possible to estimate endogenous dopamine levels occupying dopamine D_2/3 receptors (D_2/3R) in humans in vivo. Our group has developed [¹¹C]-(+)-PHNO, the first agonist radiotracer with preferential in vivo affinity for D₃R. Thus, the use of [¹¹C]-(+)-PHNO offers the novel possibility of (i) estimating in vivo endogenous dopamine levels at D_2/3R using an agonist radiotracer, and (ii) estimating endogenous dopamine levels at D₃R in extrastriatal regions such as the substantia nigra, hypothalamus, and ventral pallidum. Ten healthy participants underwent a [¹¹C]-(+)-PHNO PET scan under baseline conditions and another under acute endogenous dopamine depletion achieved via oral administration of alpha-methyl-para-tyrosine (64 mg/kg). [¹¹C]-(+)-PHNO binding was sensitive to acute dopamine depletion, allowing in vivo estimates of endogenous dopamine in D₂R-rich regions (caudate and putamen), mixed D_2/3R-rich regions (ventral striatum and globus pallidus), and extrastriatal D₃R-rich regions (hypothalamus and ventral pallidum). Dopamine depletion decreased self-reported vigor, which was correlated with the reduction in dopamine levels in the globus pallidus. [¹¹C]-(+)-PHNO is a suitable radiotracer for use in estimating endogenous dopamine levels at D₂R and D₃R in neuropsychiatric populations.