Directional diffusivity changes in the optic nerve and optic radiation in optic neuritis

OBJECTIVE

Optic neuritis (ON) is defined as an inflammation of the optic nerve and provides a useful model for studying the effects of inflammatory demyelination of white matter. The aim of this study was to assess the diffusion changes in both the optic nerve and optic radiation in patients with acute and chronic ON using diffusion tensor (DT) MRI.

METHODS

33 patients with idiopathic demyelinating optic neuritis (IDON) and 33 gender- and age-matched healthy controls were examined with DT-MRI and with T(1) and T(2) weighted MRI.

RESULTS

Compared with controls, both first-episode and recurrent patients with IDON in the acute stage showed significantly increased radial diffusivity (λ(⊥)) and decreased mean fractional anisotropy (FA) in the affected nerves. Reduced FA, increased λ(⊥), mean diffusivity (MD) and axial diffusivity (λ(∥)) were determined in patients with subacute IDON. We found no significant difference in the directional diffusivity of optic radiation in patients whose disease had lasted less than 1 year compared with healthy controls. However, significant changes in the FA and λ(⊥) of the optic radiation were detected in patients with disease duration of more than 1 year.

CONCLUSION

These results show the great potential and capacity of DT-MRI measures as useful biomarkers and indicators for the evaluation of myelin injury in the visual pathway.

Molecular cloning of HSP70 in Mycoplasma ovipneumoniae and comparison with that of other mycoplasmas

Mycoplasma ovipneumoniae, a bacterial species that specifically affects ovine and goat, is the cause of ovine infectious pleuropneumonia. We cloned, sequenced and analyzed heat shock protein 70 (HSP70) (dnaK) gene of M. ovipneumoniae. The full length open reading frame of the M. ovipneumoniae HSP70 gene consists of 1812 nucleotides, with a G+C content of 34.16%, encoding 604 amino acids. Comparative analysis with the HSP70 sequences of 15 Mycoplasma species revealed 59 to 87% DNA sequence identity, with an amino acid sequence identity range of 58 to 94%. M. ovipneumoniae and M. hyopneumoniae shared the highest DNA and amino acid sequence identity (87 and 94%, respectively). Based on phylogenetic analysis, both the DNA and amino acid identities of M. ovipneumoniae with other mycoplasmal HSP70 were correlated with the degree of relationship between the species. The C-terminus of the HSP70 was cloned into a bacterial expression vector and expressed in Escherichia coli cells. The recombinant C-terminal portion of HSP70 protein strongly reacted with convalescent sera from M. ovipneumoniae-infected sheep, based on an immunoblotting assay. This indicates that HSP70 is immunogenic in a natural M. ovipneumoniae infection and may be a relevant antigen for vaccine development.

Optimal systolic and diastolic reconstruction windows for coronary CT angiography using 320-detector rows dynamic volume CT

AIM

To investigate the optimal pattern of systolic and diastolic reconstruction windows for coronary computed tomography (CT) angiography using 320-detector rows dynamic volume CT (DVCT).

MATERIAL AND METHODS

A prospective analysis was performed on the data from 77 patients who were admitted between December 2008 and July 2009 for DVCT. The images were reconstructed in 10% steps throughout the 10-100% of R-R interval. Data sets for the three major coronary arteries [right coronary artery (RCA), left anterior descending artery (LAD), and left circumflex artery (LCX)] were evaluated by two independent readers. The quality of the images from each examined artery was graded from 1 (no motion artefacts) to 4 (severe motion artefacts over the entire vessel). The optimal systolic and diastolic reconstruction windows and the relationship between image quality and heart rate (HR) were analysed. The HR at which the optimal reconstruction window shifted from diastole to systole was predicted.

RESULTS

The average HR during imaging was 69.5±12.8 beats/min (range 46-102beats/min). HR was positively correlated with the proportion of systole (r=0.78, p<0.001). As HR increased, the optimal reconstruction windows shifted to later phases in both systole and diastole. Image quality for optimal systolic and diastolic reconstructions both deteriorated significantly with higher HRs (r=0.38, p<0.001; r=0.82, p<0.001). However, image quality in systolic reconstructions did not deteriorate as much as in diastolic reconstructions. The cut-off HRs at which optimal reconstruction intervals turned from diastole to systole was 90.8beats/min.

CONCLUSIONS

In patients with a low HR, the optimal coronary reconstruction window is in mid-late diastole. As the HR increases, systolic reconstruction often yields superior image quality compared with diastolic reconstruction.

A laparoscopic approach to ventriculoperitoneal shunt placement with a novel fixation method for distal shunt catheter in the treatment of hydrocephalus

BACKGROUND

The laparoscopically assisted ventriculoperitoneal (VP) shunt has been widely used in the clinical treatment of hydrocephalus for its simplicity and reliability. Despite significant improvements in shunt procedures, shunt complications remain common. Our clinical experiences suggest that the fixation of the distal (peritoneal) shunt catheter using threads and hemoclips may partially contribute to complications of the distal shunt including obstruction of the shunt and infection. In this study, we explored a novel fixation method in the laparoscopically assisted VP shunt with use of the liver falciform ligament as a natural support for fixation of the distal shunt catheter.

METHODS

10 patients with hydrocephalus underwent laparoscopically assisted VP shunt and the distal shunt catheter was placed into the hepatodiaphragmatic space and the catheter was traversed through 2-3 drilled holes in the liver falciform ligament without using any artificial material for fixation.

RESULTS

In all the patients who received surgery with the adopted new procedure the clinical symptoms were alleviated. The size of cerebral ventricles returned to normal after 1 week. The distal catheters were in the hepatodiaphragmatic space in 9 of 10 patients, while in 1 patient it migrated to the peritoneal cavity underneath the liver. All the 9 patients were followed up for 1 year and no surgery-related catheter obstructions and infections were observed.

CONCLUSIONS

The modified laparoscopically assisted VP shunt in the treatment of hydrocephalus with fixation of the distal shunt catheter to a natural anatomic structure could potentially reduce the necessity of repeat surgery for addressing the complications caused by catheter obstruction and infections, reduce the chance of adhesions, and would be of benefit to those patients who need future revisions.

The effect of overweight and obesity on psoriasis patients in Chinese Han population: a hospital-based study

BACKGROUND

Accumulating evidence indicates that psoriasis is associated with increased risk of overweight and obesity. However, few studies have investigated this relationship in Chinese Han population.

OBJECTIVE

The aim of this study was to explore the relationship between overweight/obesity and psoriasis and to evaluate the overweight/obesity effect on the clinical features of psoriasis in Chinese Han population.

METHODS

A hospital-based study was conducted, which involved in 4452 patients and 1166 controls of Chinese Han through epidemiological investigation. Controls used in the study were individuals without psoriasis from health examination centre, and other skin disease patients from outpatient department.

RESULTS

Compared with the control group, a significantly greater prevalence of overweight and obesity was observed in psoriasis patients. The estimated ORs were 1.301 (95% CI, 1.105-1.531) and 1.680 (95% CI, 1.134-2.491) respectively. The disease severity of psoriasis measured by psoriasis area and severity index (PASI) was statistically correlated with body mass index (BMI) (r = 0.184, P < 0.01). Moreover, a high proportion of overweight patients had affected hands or/and feet, buttocks, trunk, legs, arms and arthritis (P < 0.01).

CONCLUSIONS

Our study suggested that psoriatic patients have a higher prevalence of overweight and obesity compared with non-psoriatic patients in Chinese Han population. Overweight and obesity has different risk effect on severity and manifestations of psoriasis and might be useful for better evaluating psoriasis clinically.

No time to lose--high throughput screening to assess nanomaterial safety

Nanomaterials hold great promise for medical, technological and economical benefits. Knowledge concerning the toxicological properties of these novel materials is typically lacking. At the same time, it is becoming evident that some nanomaterials could have a toxic potential in humans and the environment. Animal based systems lack the needed capacity to cope with the abundance of novel nanomaterials being produced, and thus we have to employ in vitro methods with high throughput to manage the rush logistically and use high content readouts wherever needed in order to gain more depth of information. Towards this end, high throughput screening (HTS) and high content screening (HCS) approaches can be used to speed up the safety analysis on a scale that commensurate with the rate of expansion of new materials and new properties. The insights gained from HTS/HCS should aid in our understanding of the tenets of nanomaterial hazard at biological level as well as assist the development of safe-by-design approaches. This review aims to provide a comprehensive introduction to the HTS/HCS methodology employed for safety assessment of engineered nanomaterials (ENMs), including data analysis and prediction of potentially hazardous material properties. Given the current pace of nanomaterial development, HTS/HCS is a potentially effective means of keeping up with the rapid progress in this field--we have literally no time to lose.

Study of brain asymmetries in sporadic and familial first episode patients with schizophrenia

Introduction

Although the deviations of brain volume deficits in sporadic and familial first-episode schizophrenia patients (FEP) had been presented, the difference of brain asymmetries remained unidentified.

Objectives

To assess the potential differences of volumetric asymmetries of gray matter (GM) and white matter (WM) between groups.

Aims

To find out the different injury alteration of sporadic FEP and familial FEP.

Methods

42 sporadic and 30 familiar drug-naïve FEP with and 72 matched normal controls (NC) were recruited. Participants were assessed with neuropsychological tests and scanned by a 3.0T MRI to obtain T1-weighted and DTI images. Lateralization distribution maps of GM and WM volume were generated by employing optimized voxel-based morphometry. The asymmetries were analyzed by comparing calculating Laterality Index (LI) voxel by voxel.

Results

All three groups showed similar overall brain torque. Familiar FEP have more regional extensive GM asymmetry brain lesions compared to sporadic FEP. There was no shared regional lesion between two groups. LIGM and LIWM in right superior temporal were negatively correlated. Significant negative correlations were also found between LIGM of left superior parietal lobule and LIWM of right superior parietal lobule, and between LIGM of right inferior parietal lobule and LIWM of left inferior parietal lobule. The asymmetry in distinct brain regions were related to cognitive deficits especially in the domains of language and memory.

Conclusions

The two patient groups had different alteration in injuries of brain asymmetry. Familiar FEP has more GM extensive asymmetry brain region, which may correlate with their high genetic burdens.

Assessment of white matter abnormalities in paranoid schizophrenia and bipolar mania patients from Chengdu, China

Introduction

White matter abnormalities have been repeatedly reported in both schizophrenia and bipolar disorder (BD) diseases from diffusion tensor imaging (DTI) studies respectively, while the empirical evidences about the diagnostic specificity of white matter abnormalities in these disorders are still limited.

Objectives

25 patients with paranoid schizophrenia and 18 patients with bipolar mania were recruited from the in-patient unit of the Mental Health Centre, West China Hospital, China.

Patients were diagnosed according to the criteria of Diagnostic and Statistical Manual of Mental Disorders-Version IV (DSM- IV). 30 healthy controls were recruited from the community by means of leaflets distributed throughout Chengdu city.

Aims

This study sought to investigate the alterations in fractional anisotropy (FA) in white matter throughout the entire brain of patients from Chengdu, China with paranoid schizophrenia and bipolar mania.

Methods

Diffusion tensor imaging (DTI) was used to assess white matter integrity in patients with paranoid schizophrenia and bipolar mania, as well as in normal controls. The differences in FA were measured by use of voxel-based analysis.

Results

Reduced FA was found in the left posterior corona radiate (PCR) in patients with bipolar mania and paranoid schizophrenia compared to the controls. Patients with bipolar mania also showed a significant reduction in FA in right posterior corona radiate and in right anterior thalamic radiation (ATR).

Conclusions

Common abnormalities in the left PCR might imply an overlap in white matter pathology of both diseases and might be related to the shared risk factors for both disorders.

Roles of HAUSP-mediated p53 regulation in central nervous system development

The deubiquitinase HAUSP (herpesvirus-associated ubiquitin-specific protease; also called USP7) has a critical role in regulating the p53-Mdm2 (murine double minute 2) pathway. By using the conventional knockout approach, we previously showed that hausp inactivation leads to early embryonic lethality. To fully understand the physiological functions of hausp, we have generated mice lacking hausp specifically in the brain and examined the impacts of this manipulation on brain development. We found that deletion of hausp in neural cells resulted in neonatal lethality. The brains from these mice displayed hypoplasia and deficiencies in development, which were mainly caused by p53-mediated apoptosis. Detailed analysis also showed an increase of both p53 levels and p53-dependent transcriptional activation in hausp knockout brains. Notably, neural cell survival and brain development of hausp-mutant mice can largely be restored in the p53-null background. Nevertheless, in contrast to the case of mdm2- and mdm4 (murine double minute 4)-mutant mice, inactivation of p53 failed to completely rescue the neonatal lethality of these hausp-mutant mice. These results indicate that HAUSP-mediated p53 regulation is crucial for brain development, and also suggest that both the p53-dependent and the p53-independent functions of HAUSP contribute to the neonatal lethality of hausp-mutant mice.

Correlation between imaging features and epithelial cell proliferation in keratocystic odontogenic tumour

OBJECTIVES

this study was undertaken to investigate the relationship between radiographic appearance and epithelial cell proliferations in keratocystic odontogenic tumours (KCOTs).

METHODS

a retrospective radiographic analysis was performed on 284 cases of KCOT to gain insight into the radiographic characteristics. Expression of Ki-67 in 30 of the 284 cases was detected by the labelled streptavidin-biotin (LSAB) method and evaluated by an image analysis system.

RESULTS

the radiographic presentation of KCOT was divided into four types: unilocular, multilocular, multiple and naevoid basal cell carcinoma syndrome (NBCCS). The expression of Ki-67 in NBCCS was significantly different from the solitary and multiple KCOTs (P = 0.018, 0.002). In multilocular KCOTs it was also significantly different from the unilocular and syndrome-associated lesions (P = 0.000). In contrast, no significant differences were observed between the solitary and multiple lesions (P = 0.220).

CONCLUSIONS

a high correlation exists in KCOT between its biological behaviour and imaging features. The solitary KCOT seems less biologically aggressive and it should be classified as a cyst rather than a tumour. This means that more than half of KCOTs manifest themselves as ordinary cysts.

Establishment of primary human esophageal xenografts: Rationale for selection and cancer model

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Background: New animal models of esophageal cancer are required to accelerate research into novel treatment strategies. Mouse xenografts used in pre-clinical drug testing are typically derived from cell lines, but several esophageal cancer cell lines have been contaminated (PMID 20075370). Xenografts implanted from surgically resected human tumors are a potentially viable model, and may better recapitulate the characteristics of the original tumor. We describe the feasibility of such an approach.

Methods: 2-10 mm esophageal carcinoma fragments obtained from resected patient tumors were implanted directly into NOD/SCID mice. Tumors that grew beyond 1.5 cm in diameter were passaged serially. Pathologic properties were assessed from passage to passage. Potential clinicopathological predictors of engraftment were evaluated.

Results: Of the 63 patients with tumors used for implantation, 67% were male; median age 66 (range 31-89); 31% node negative disease; 69% node positive disease; 12% metastatic; 55% received neoadjuvant therapy; 12% had prior Barrett's esophagus; 46% had pre-existing heartburn; 88% were distal esophageal/GE junction cancers. Engraftment occurred in 14/43 (33%) adeno-, 1/14 (7%) squamous, and 1/1 adenosquamous carcinomas (p=0.05; 5 others were rare tumors e.g. granular or small cell). Engraftment occurred in 6/31 well/moderately vs 7/18 poorly differentiated tumors (p=0.08). Because we amended our implantation procedures, we compared engraftment rates pre- (7/39; 18%) and post-amendment (8/23; 35%; p=0.13). The primary architecture of the xenografted tissue remained similar pathologically for up to 5+ passages. None of the following variables predicted for engraftment (p>0.20 each comparison): cancer location, age, gender, history of heartburn, pre-operative therapy, presence of Barrett's esophagus, disease stage, or recurrence of primary cancer.

Conclusions: Creation of esophageal cancer xenografts from primary human resected specimens is feasible. Adenocarcinomas, higher tumor grade, and newer implantation strategies were associated with improved engraftment. We are treating these models with chemotherapy to discover new pharmacogenomic predictive biomarkers.

No significant financial relationships to disclose.

The EEL-1 ubiquitin ligase promotes DNA damage-induced germ cell apoptosis in C. elegans

E3 ubiquitin ligases target a growing number of pro- and anti-apoptotic proteins, including tumour suppressor p53, caspases, and the Bcl-2 family. The core apoptosis pathway is well conserved between mammals and Caenorhabditis elegans, but the extent to which ubiquitin ligases regulate apoptotic cell death is not known. To investigate the role of E3 ligases in apoptosis, we inhibited 108 of the 165 predicted E3 ubiquitin ligase genes by RNA interference and quantified apoptosis in the C. elegans germline after genotoxic stress. From this screen, we identified the homologous to E6-associated protein C terminus-domain E3 ligase EEL-1 as a positive regulator of apoptosis. Intriguingly, the human homologue of EEL-1, Huwe1/ARF-BP1/Mule/HectH9, has been reported to possess both pro- and anti-apoptotic functions through its ability to stimulate Mcl-1 and p53 degradation, respectively. Here, we demonstrate that eel-1 is required to promote DNA damage-induced germ cell apoptosis, but does not have a role in physiological germ cell apoptosis or developmental apoptosis in somatic tissue. Furthermore, eel-1 acts in parallel to the p53-like gene cep-1 and intersects the core apoptosis pathway upstream of the Bcl-2/Mcl-1 orthologue ced-9. Although ee1-1 mutants exhibit hypersensitivity to genotoxic stress they do not appear to be defective in DNA repair, suggesting a distinct role for EEL-1 in promoting damage-induced apoptosis in the germline.