Characterization of MGMT and EGFR protein expression in glioblastoma and association with survival

Journal of Neuro-Oncology - Understanding the molecular landscape of glioblastoma (GBM) is increasingly important in the age of targeted therapy. O-6-Methylguanine-DNA methyltransferase (MGMT)...     

From the Cover: Complex history of the amphibian-killing chytrid fungus revealed with genome resequencing data

Understanding the evolutionary history of microbial pathogens is critical for mitigating the impacts of emerging infectious diseases on economically and ecologically important host species. We used a genome resequencing approach to resolve the evolutionary history of an important microbial pathogen, the chytrid Batrachochytrium dendrobatidis (Bd), which has been implicated in amphibian declines worldwide. We sequenced the genomes of 29 isolates of Bd from around the world, with an emphasis on North, Central, and South America because of the devastating effect that Bd has had on amphibian populations in the New World. We found a substantial amount of evolutionary complexity in Bd with deep phylogenetic diversity that predates observed global amphibian declines. By investigating the entire genome, we found that even the most recently evolved Bd clade (termed the global panzootic lineage) contained more genetic variation than previously reported. We also found dramatic differences among isolates and among genomic regions in chromosomal copy number and patterns of heterozygosity, suggesting complex and heterogeneous genome dynamics. Finally, we report evidence for selection acting on the Bd genome, supporting the hypothesis that protease genes are important in evolutionary transitions in this group. Bd is considered an emerging pathogen because of its recent effects on amphibians, but our data indicate that it has a complex evolutionary history that predates recent disease outbreaks. Therefore, it is important to consider the contemporary effects of Bd in a broader evolutionary context and identify specific mechanisms that may have led to shifts in virulence in this system.Emerging infectious diseases (EIDs) pose significant challenges for human health, agricultural crops, and economically and ecologically important populations in nature (1–4). The incidence of EIDs has been steadily rising over the last several decades (5, 6), and EIDs are of particular concern in an increasingly globalized world. For example, the majority of human EIDs is zoonoses that originate in wildlife (5) and subsequently, create a significant burden for global economies and public health (7, 8). Therefore, scientific efforts to understand and respond to EIDs are critical in diverse fields from biomedicine to conservation biology.Although EIDs result from a complex interplay of factors, many studies focus primarily on the emergence of novel microbial pathogens. There are, in fact, high-profile examples of EIDs caused by the rapid appearance of novel, hypervirulent, or host-switching strains (9–11), but EIDs are not always caused by rapid or recent evolution of the pathogen itself. Virulence itself is an emergent property of microbe–host–environment interactions (12). Thus, EIDs can result from shifts in any factor—or combination of factors—in the microbe–host–environment epidemiological triangle (13). Characterizing the evolutionary history of emerging pathogens is, thus, critical, allowing us to determine whether observed EIDs result from rapid, recent shifts in organisms with pathogenic potential.Chytridiomycosis is an EID responsible for declines in amphibian species around the world. The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered and linked to amphibian declines in 1998 (14, 15). Chytridiomycosis is caused by Bd and kills amphibians by disrupting the integrity of their skin, a physiologically important organ that is involved in gas exchange, electrolyte balance, hydration, and protection from other pathogens (16, 17). Bd infects hundreds of species of amphibians, is found on all continents where amphibians occur, and is responsible for declines and extirpations in a diversity of amphibian hosts (18).Soon after Bd was discovered, researchers proposed two competing hypotheses for the emergence of chytridiomycosis. The emerging pathogen hypothesis posited that a novel disease agent caused chytridiomycosis, and the endemic pathogen hypothesis proposed that an environmental shift disrupted a previously benign microbe–host interaction (19). Over the years, spatiotemporal and genetic data have supported the emerging pathogen hypothesis (reviewed in refs. 20 and 21). Spatiotemporal data provided clear evidence that Bd arrived and spread through geographic regions where it was not present historically (22–24). Early genetic studies also found very little genetic differentiation in Bd with no geographic signal, consistent with a recent, rapid spread of a novel disease agent (25–27). Recently, genetic and genomic data have been used to describe a geographically widespread Bd lineage [termed the global panzootic lineage (GPL)] (28) and several putatively endemic Bd lineages (28–30). However, different studies have used different methods and focused sampling in different parts of the world, precluding integration across studies to determine the evolutionary history leading to the emergence of Bd as a global threat to amphibians.Here, we present whole-genome sequencing from a global panel of Bd isolates to show that Bd has a historically deeper and more complex evolutionary history than previously appreciated. We sequenced Bd genomes from around the world and also, a non-Bd chytrid outgroup that does not attack amphibians [Homolaphlyctis polyrhiza (Hp)] (31). Our focus was primarily on the evolutionary dynamics of Bd in the Americas, because many of the most devastating outbreaks have occurred in the New World. We address outstanding questions about the origins, genetic diversity, and genome structure of Bd that can be resolved using whole-genome data. We also integrate our genomic data with those data from a previous study with complementary geographic sampling (28). Our results reveal that the evolutionary history of Bd is complex, with multiple divergent lineages, heterogeneous patterns of genomic evolution, and no simple link between a single evolutionary event and observed amphibian declines.     

定量组织速度成像技术评价阿霉素诱导兔心肌病模型：与常规经胸超声心动图比较

目的:采用定量组织速度成像技术评价阿霉素诱导兔心肌病模型,并与常规经胸超声心动图比较其评估优势。方法:实验于2005-06/2006-08在大连医科大学完成。①实验分组及处理:取纯种新西兰白兔22只,雌雄不限,随机分成阿霉素组12只,给予阿霉素每次2mg/kg,以1g/L耳缘静脉注射,每周1次,注射8周;对照组10只每周注射2mL/kg生理盐水,共8周。②实验评估:每周应用HPSonos5500型彩色多普勒超声诊断仪(美国Agilent公司生产)对两组兔心脏进行左室收缩末期和舒张末期内径明、室间隔厚度、E峰、射血分数、左室短轴缩短率等常规超声参数测量,使用GEVivid7型彩色多普勒超声诊断仪(美国GE公司生产)进行收缩期和舒张期峰值速度、收缩期加速度定量组织速度成像参数测定。结果:22只兔进入统计。①对照组1～12周各参数与阿霉素组基础状态下比较无明显差异(P>0.05)。②第4周阿霉素组二尖瓣环运动的平均收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P均<0.05)。③第7周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.05)。④第8周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),E峰较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.05)。⑤第12周阿霉素组二尖瓣环运动的收缩期和舒张期峰值速度、收缩期加速度较基础状态明显减低(P<0.01),左室收缩末期和舒张末期内径明显增大(P<0.01),室间隔厚度、左室后壁厚度明显变薄(P<0.05),射血分数、左室短轴缩短率和E峰明显减低(P<0.01)。结论:定量组织速度成像参数可有效评价阿霉素诱导心肌病模型兔心肌的病理变化,较常规超声参数更敏感。     

Treatment of deep cerebral venous thrombosis by local infusion of tissue plasminogen activator

BACKGROUND

Treatment of extensive intracranial venous sinus thrombosis with thrombolytic drugs is described, although the indications for and most efficacious technique for achieving thrombolysis remain uncertain. We report the successful lysis of superficial and deep venous system thrombosis by infusion of recombinant human tissue-type plasminogen activator (rt-PA) into the anterior superior sagittal sinus.

CASE DESCRIPTION

A 34-year-old man presented with headaches followed by decreased level of consciousness and left hemiplegia. Angiography showed thrombosis of the superior sagittal and both transverse and straight sinuses with extension into the internal cerebral veins. The superior sagittal sinus was catheterized via a transfemoral route and rt-PA, 25 mg, was infused. There was no significant change in the thrombosis. The catheter was left in place and rt-PA was infused at 1 mg/minute for 19 hours. Repeat angiography showed resolution of the thrombosis. The patient was placed on heparin and then coumadin. He recovered completely.

CONCLUSIONS

This report suggests that superselective infusion of thrombolytics into thrombosed intracranial venous sinuses can lyse intracranial venous sinus thrombosis. The thrombolytic agent must be infused for hours. The apparent successful lysis of clot in the deep venous system when infusion was into the superior sagittal sinus might be related to diffusion of rt-PA throughout the intracranial venous system or to improved venous outflow caused by lysis of clot in superficial dural sinuses.     

Optimizing quantitative in vivo fluorescence imaging with near‐infrared quantum dots

Quantum dots (QDs) are fluorescent nanoparticles with broad excitation and narrow, wavelength‐tunable emission spectra. They are used extensively for in vitro fluorescence imaging studies and more recently for in vivo small animal and pre‐clinical studies. To date there has been little concern about the selection of QD size (and thus emission wavelength peak) and excitation wavelengths, as they have little relevance to the results of in vitro studies. In vivo imaging, however, poses additional constraints, such as the scattering and absorption by tissue, which may influence the signal intensity at the body surface. Here, we demonstrate that longer‐wavelength excitation and emission yield less quantization error in measured relative fluorescence intensity, using three near‐infrared QDs (QD655, QD705 and QD800) applied to in vivo lymphatic imaging, and a range of excitation wavelengths from the blue to the red. Statistically significant differences in quantization error were observed between nearly all pairs of excitation wavelengths (445–490, 503–555, 575–605, 615–665 and 671–705 nm). Similarly, quantization error decreased with longer emission wavelengths (655, 705 and 800 nm). Light absorbance and scattering were demonstrated to be more potent factors than absorbance efficiency of QDs in producing quantization error in the measured fluorescence intensity. As a result, while wavelengths can be adjusted for qualitative experiments, the longest possible wavelengths should be used if quantification is desired during QD imaging experiments. Copyright © 2010 John Wiley & Sons, Ltd.     

Disruptions and Satisfaction in Internal Medicine Resident Continuity Clinic Differ Between Inpatient and Outpatient Rotations

Abstract

Background: Little is known about whether assignment to simultaneous inpatient and outpatient clinical duties causes disruptions during internal medicine resident continuity clinic and impacts trainee satisfaction.

Purpose: Our purpose was to determine whether dual inpatient and continuity clinic responsibilities impact resident stress and document the number, type, and immediacy of interruptions in continuity clinics.

Methods: Methods included a prospective 2-residency survey of 70 internal medicine residents performing 240 half-day continuity clinic sessions.

Results: More than half (52%) of trainees on inpatient rotations felt pressured to return to their ward duties. Half (50%) of residents thought clinic increased work hours, and the majority (70%) did not think continuity clinic detracted from their education on inpatient or elective rotations. Disturbances were more likely to occur on inpatient rotations (odds ratio 4.52, 95% confidence interval = 2.29-8.92) than on outpatient rotations. The time required to address an interruption was 3.9 ± 4.51 min. Residents thought many (46%) problems addressed during clinic could have waited until clinic completion.

Conclusions: Residents on inpatient rotations who were commonly interrupted in clinic felt pressured to return to ward duties and unable to focus on their clinic patients. Internal medicine faculty should modify curriculum to minimize the interference of other duties in resident clinics.     

Rolandic encephalopathy and epilepsia partialis continua following bone marrow transplant

Epilepsia partialis continua (EPC) is a condition defined by prolonged focal myoclonus. Often resistant to therapy, EPC in children is frequently present in Rasmussen encephalitis, a form of chronic encephalitis of uncertain etiology. We discuss a child who developed bilateral EPC 5 months after a bone marrow transplant. Neuroimaging studies showed signal abnormalities on both sensory-motor areas. An extensive search failed to reveal the etiology of the disorder, but treatment with a broad-spectrum anti-viral agent was associated with resolution of the process. An unidentified infectious agent may be responsible for an encephalitis of the motor strip in immunosuppressed patients.     

Drug problem recognition, desire for help, and treatment readiness in a soup kitchen population

This study determined hypothesized predictors of three components of motivation for change--drug problem recognition, desire for help, and treatment readiness--in a high-risk, drug-using population. The sample consisted of 190 guests at two inner-city soup kitchens in Brooklyn, NY who reported drug/alcohol use and were not participating in substance dependency treatment. Ever receiving addiction treatment, having no trade/job skills, and more severe symptoms of depression were associated with greater drug problem recognition. More recent days of drug/alcohol use, intensive pattern of drug use, and greater problem recognition were associated with greater desire for help. Caring for children, more recent days of drug/alcohol use, physical health problems, and desire for help were the direct predictors of treatment readiness. Problem recognition had a strong indirect effect on readiness mediated through desire for help. Knowledge of a drug user's motivational state and the factors leading to it can help guide the development of more effective interventions.     

Medical outreach to homeless substance users in New York City: preliminary results

An innovative, experimental, medical out-reach initiative, using a fully-equipped mobile medical van with a staff of 2 part-time physicians, a physician assistant, a social worker, and a driver/medical aid serving the needs of 1048, mostly male, minority group, high-level, homeless New York City substance users with infectious diseases is described. The study sample (N = 250) was divided into experimental S's who received Intensive case management and a control group who could choose to refer themselves to the SW. Biological tests revealed high rates of cocaine use and infectious diseases. Preliminary 4-month outcomes (N = 128) showed reductions in drug use, homelessness and health complaints in both groups; experimental subjects compared with controls received more Public Assistance and had fewer emergency room visits.