Postoperative changes in cerebral metabolites associated with cognitive improvement and impairment after carotid endarterectomy: a 3T proton MR spectroscopy study

BACKGROUND AND PURPOSE

Cognitive function can improve or decline after carotid endarterectomy. Proton MR spectroscopy can be used evaluate cerebral metabolites, such as N-acetylaspartate, choline, and creatine, in vivo. The purpose of the present study was to determine whether postoperative changes in cerebral metabolites measured by using 3T proton MR spectroscopy were associated with changes in cognitive function after CEA.

MATERIALS AND METHODS

In 100 patients undergoing CEA for ipsilateral cervical internal carotid artery stenosis (≥70%), brain proton MR spectroscopy was performed before and after surgery. NAA/Cr and Cho/Cr ratios were measured in regions of interest placed in the centrum semiovale of both cerebral hemispheres. Neuropsychological testing was also performed preoperatively and 1 month postoperatively. Multivariate statistical analysis of factors related to postoperatively changed cognition was performed, and odds ratios with 95% confidence intervals were calculated.

RESULTS

On the basis of the neuropsychological assessments, 10 (10%), 80 (80%), and 10 (10%) patients were defined as having postoperatively improved, unchanged, and impaired cognition, respectively. A positive and high ΔNAA/Cr ratio (postoperative value-preoperative value) in the cerebral hemisphere ipsilateral to the operative site was significantly associated with postoperatively improved cognition (95% CI, 13.3-21.3; P = .0016). Negative and high absolute values of the ΔNAA/Cr ratio (95% CI, 0.018-0.101; P = .0039) and ΔCho/Cr ratio (95% CI, 0.042-0.135; P = .0046) in the ipsilateral cerebral hemisphere were significantly associated with postoperatively impaired cognition.

CONCLUSIONS

Postoperative changes in cerebral metabolites measured by using proton MR spectroscopy were associated with changes in cognitive function after CEA.

Biochemical and hematologic effects of polyvinylpyrrolidone-wrapped fullerene C60 after oral administration

The fullerene C60 is used in consumer products such as cosmetics owing to its antioxidative effects and is being developed for nanomedical applications. However, knowledge regarding the safety of fullerene C60, especially after oral administration, is sparse. Here, we examined the safety of fullerene C60 in mice after 7 d of exposure to orally administered polyvinylpyrrolidone (PVP)-wrapped fullerene C60 (PVP-fullerene C60). Mice treated with PVP-fullerene C60 showed few changes in the plasma levels of various markers of kidney and liver injury and experienced no significant hematologic effects. Furthermore, the histology of the colon of PVP-fullerene C60-treated mice was indistinguishable from that of control mice. These results suggest that PVP-fullerene C60 lacks toxicity after high-dose oral administration and indicate that PVP-fullerene C60 can be considered safe for oral medication. These data provide basic information that likely will facilitate the production of safe and effective forms of fullerene C60.

Clinical efficacy of abatacept in Japanese rheumatoid arthritis patients

OBJECTIVES

The purpose of this study was to examine the treatment retention and efficacy of abatacept, the first member of a new class of biologic agents, in Japanese rheumatoid arthritis (RA) patients during clinical practice.

METHODS

A retrospective multicenter study was conducted with patients who underwent abatacept therapy for 24 weeks (n = 143).

RESULTS

Patients at baseline had a mean age of 63.5 years, a mean disease duration of 11.3 years, and a mean disease activity score in 28 joints (DAS28) of 4.5. Overall retention of abatacept treatment was 83.2 % at 24 weeks, when 46.2 % of patients achieved DAS28-defined low disease activity (LDA; DAS28 <3.2) and 26.6 % achieved DAS28-defined remission (DAS28 <2.6). LDA was achieved in a significantly higher proportion of patients without prior biologics therapy compared to those with prior biologics (60.9 vs. 34.2 %, p = 0.001). There was no significant difference between patients with or without concomitant methotrexate (MTX) therapy (45.2 vs. 47.5 %).

CONCLUSIONS

Abatacept therapy appears to be highly effective and well tolerated during clinical treatment of RA. Abatacept was particularly effective in patients with no history of biologics use, and did not appear to be dependent on concomitant MTX therapy.

Dermal absorption of amorphous nanosilica particles after topical exposure for three days

The skin penetration and cellular localization of well-dispersed amorphous nanosilica particles (nSPs) with a diameter of 70 nm was analyzed in mice. Our results suggest that after topical exposure for three days the particles penetrate the skin barrier and are transported to the lymph nodes. These findings underscore the need to examine biological effects following dermal exposure to nSPs for the development of safer use of nSPs.

Amorphous nanosilica particles induce ROS generation in Langerhans cells

Generation of total intracellular reactive oxygen species (ROS) was measured in XS52 cells, a Langerhans cell-like line, treated with different sized amorphous silica particles. The results suggested that exposure to amorphous nanosilica particles (nSPs) with a particle size of 70 nm induced a higher level of ROS generation than did exposure to micron-sized amorphous silica particles. This finding means that it is essential to examine the biological effects of ROS generated after exposure to nSPs, which will provide useful information for hazard identification as well as the design of safer nanomaterials.

Rho GDP-dissociation inhibitor alpha is associated with cancer metastasis in colon and prostate cancer

Since metastasis is one of the most important prognostic factors in colorectal cancer, development of new methods to diagnose and prevent metastasis is highly desirable. However, the molecular mechanisms leading to the metastatic phenotype have not been well elucidated. In this study, a proteomics-based search was carried out for metastasis-related proteins in colorectal cancer by analyzing the differential expression of proteins in primary versus metastasis focus-derived colorectal tumor cells. Protein expression profiles were determined using a tissue microarray (TMA), and the results identified Rho GDP-dissociation inhibitor alpha (Rho GDI) as a metastasis-related protein in colon and prostate cancer patients. Consequently, Rho GDI may be useful as a diagnostic biomarker and/or a therapeutic to prevent colon and prostate cancer metastasis.

Rectal duplication cyst successfully treated by laparoscopic total mesorectal excision using the prolapsing technique

Congenital alimentary tract duplication is a rare disease. It most frequently occurs in the ileum, with the rectum being the rarest site. Herein, we report a 38-year-old woman who was referred to our hospital because of severe anal pain. On digital examination, a smooth, round, rubbery mass was palpable; it was located 5 cm from the anal verge in the posterior rectal wall. A CT scan demonstrated a 5-cm cystic lesion located anterior to the sacrum that was displacing the rectum anteriorly. Spontaneous remission of the tumor was evident; however, after 5 months of follow-up, the patient experienced the same severe anal pain. MRI demonstrated a recurrent cystic lesion. To prevent further complications and to confirm or deny malignancy, laparoscopic total mesorectal excision using the prolapsing technique was performed. Pathologically, the cystic lesion was diagnosed as a rectal duplication cyst. This is the first report of a rectal duplication cyst successfully treated by laparoscopic total mesorectal excision.

Detection of titanium dioxide particles on frozen tissue sections using synchrotron radiation X-ray fluorescence analysis

Recent studies into the in vivo absorption and biological influence of particulate matter, especially nanomaterials (NMs), have raised worldwide concerns over their safety. However, it is often technically difficult to conduct these studies because NMs are too small to be observed by optical microscopy. Here, we attempted to establish a new method to visually detect NMs on tissue samples. Specifically, we have analyzed titanium dioxide particles with a diameter of 5 microm, which are widely used in cosmetics, using frozen tissue sections by synchrotron radiation X-ray fluorescence analysis.

Size-dependent immune-modulating effect of amorphous nanosilica particles

The immune-modulating effect following intradermal injection of various-sized amorphous silica particles was analyzed in terms of induction of ovalbumin-specific CD8+ T cells in vivo. IFN-gamma ELISPOT assays revealed that only nanosilica particles with a diameter of less than 100 nm significantly enhanced CD8+ T cell responses against ovalbumin. These results indicate that the size of nanomaterials is a critical determinant in terms of their safe use.

Application of chemical reaction mechanistic domains to an ecotoxicity QSAR model, the KAshinhou Tool for Ecotoxicity (KATE)

The validity of chemical reaction mechanistic domains defined by skin sensitisation in the Quantitative Structure-Activity Relationship (QSAR) ecotoxicity system, KAshinhou Tools for Ecotoxicity (KATE), March 2009 version, has been assessed and an external validation of the current KATE system carried out. In the case of the fish end-point, the group of chemicals with substructures reactive to skin sensitisation always exhibited higher root mean square errors (RMSEs) than chemicals without reactive substructures under identical C- or log P-judgements in KATE. However, in the case of the Daphnia end-point this was not so, and the group of chemicals with reactive substructures did not always have higher RMSEs: the Schiff base mechanism did not function as a high error detector. In addition to the RMSE findings, the presence of outliers suggested that the KATE classification rules needs to be reconsidered, particularly for the amine group. Examination of the dependency of the organism on the toxic action of chemicals in fish and Daphnia revealed that some of the reactive substructures could be applied to the improvement of the KATE system. It was concluded that the reaction mechanistic domains of toxic action for skin sensitisation could provide useful complementary information in predicting acute aquatic ecotoxicity, especially at the fish end-point.