Safety of treatment of latent tuberculosis infection in compensated cirrhotic patients during transplant candidacy period

BACKGROUND: Treatment of latent tuberculosis infection with isoniazid (INH) or rifampin (RIF) is controversial in liver transplant candidates due to potential hepatotoxicity. In this study, treatment of latent tuberculosis during transplant candidacy period is explored, and relevant literature is reviewed. METHODS: Liver transplant candidates with latent tuberculosis infection by positive tuberculin skin test (>5 mm) were prospectively enrolled and treated with 9 months of INH or 4 months of RIF, and were monitored monthly for their liver enzyme profiles, adverse effects, compliance, and completion rate. RESULTS: Four of nine patients with INH had asymptomatic, mild elevations of aspartate aminotransferase (AST) or alanine aminotransferase (ALT) versus none of five patients in the RIF group. Two cases of elevations were attributed to INH. Two other cases were attributed to alcoholism or active chronic hepatitis B virus infection. Only one patient in the INH group experienced symptoms possibly attributed to INH hepatotoxicity. Compliance was 100% per patient reporting. Completion rates were 79% for INH and 100% for RIF. No fulminant hepatic failure or death was observed. CONCLUSION: Treatment of latent tuberculosis in liver transplant patients during their candidacy with INH or RIF appears to be a safe, viable option, if carefully monitored for adverse effects and liver enzymes.     

Use of diffusion tensor imaging to evaluate weakness

OBJECT: Recently, diffusion tensor (DT) imaging was introduced to demonstrate white matter tracts. However, research interest has focused on the anatomical rather than the functional aspects of this imaging modality. The authors undertook a functional analysis of DT imaging to determine the relationship between weakness and changes on DT images. METHODS: Diffusion tensor images were obtained in 23 patients with lesions located adjacent to the pyramidal tract. Patients were classified according to their motor deficit. Axial magnetic resonance image sections through the maximum tumor diameters were selected and the mean apparent diffusion coefficients (ADCs) and mean fractional anisotropies (FAs) were measured. One ovoid region of interest (ovROI) was placed in the center of the pyramidal tract and another was designed to include the whole pyramidal tract at the same axial level (wROI). To determine intraobserver variability, a single neurosurgeon measured mean ADCs and FAs four times by using these two different ROI types without knowledge of any clinical information. To determine interobserver variability, a second neurosurgeon who was also unaware of any clinical information measured the mean ADCs and FAs by using the wROI method. The five measurements produced the same results. The mean FA at the lesion side of the pyramidal tract was significantly lower in patients with weakness (p < 0.01). Little intraobserver measurement variability occurred using the ovROI method, and no interobserver variability occurred using the wROI method. CONCLUSIONS: Motor weakness was significantly related to a low mean FA in the pyramidal tract on the lesion side. Designing an ROI that includes the whole pyramidal tract is an easier and more reproducible method than using an ovROI method.     

C1-2 transarticular screw fixation in high-riding vertebral artery: suggestion of new trajectory

A significant drawback of atlantoaxial transarticular screw fixation is a potential risk of vertebral artery injury, especially with a high-riding type. The authors propose a relatively safe trajectory in cases of high-riding vertebral artery by using the 3-dimensional computerized tomography image reconstruction programs. Twelve consecutive patients with a pathologic condition in atlantoaxial complex were prospectively analyzed. Five other patients, whose high-riding vertebral arteries were incidentally found during the 3-dimensional computerized tomography performance for other cervical pathologic conditions, were also included. The preoperative screw simulation images, convergence angle, and caudal tilting angle for each screw were obtained from each patient. Of 17 subjects, 7 had high-riding vertebral artery unilaterally and 1 had bilaterally. All 12 patients with pathologic atlantoaxial complex, including 2 unilateral and 1 bilateral high-riding vertebral artery, had atlantoaxial transarticular screw fixation. For these 3 patients, the entry point and the trajectory for screw were moved more superiorly and medially as in cases with C2 pedicle screwing. The mean convergence angle and caudal tilt angle obtained during screw simulation for patients with high-riding vertebral arteries was 17.6 and 38 degrees compared with 21 and 53.3 degrees for patients with normal course of vertebral artery. It was possible to insert transarticular screws safely in patients with high-riding vertebral artery guided by preoperative screw insertion simulation program.     

Cytotoxic constituents isolated from the fruit bodies ofHypsizigus marmoreus

The bioactivity-guided fractionation of chloroform extracts of the fruit bodies of Hypsizigus marmoreus led to our isolation of (22E,24R)-ergosta-7,22-diene-3beta,5alpha,6beta-triol (1), ergosterol-3-O-beta-D-glucopyranoside (2), 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (3), hypsiziprenol A9 (4), hypsiziprenol AA8 (5), hypsiziprenol AA9 (6) and hypsiziprenol BA10 (7). Among these seven isolates, compound 2 was identified for the first time from this plant. All compounds (1-7) exhibited moderate cytotoxicity towards cultured human colon carcinoma (HT-29), human breast carcinoma (MCF-7) and human hepatoblastoma (HepG-2) cell lines.     

Water-deprivation-induced expression of neuronal nitric oxide synthase in the hypothalamic paraventricular nucleus of rat

This study was conducted to define the molecular mechanism by which dehydration induces expression of neuronal nitric oxide synthase (nNOS) in the hypothalamic paraventricular nucleus (PVN). Rats were deprived from water for 48 hr and then sacrificed immediately or 1 hr after ad libitum access to water. Another group of rats had free access to food and water and was included as euhydrate control group. The PVN sections fixed with 4% paraformaldehyde were processed for nNOS immunohistochemistry and NADPH-diaphorase (NADPH-d)/pCREB or NADPH-d/c-Fos double staining. nNOS-ir neurons significantly increased with water deprivation and decreased with rehydration, both in the posterior magnocellular (pM)- and the medial parvocellular (mP)-PVN. Most NADPH-d histostained neurons in the PVN appeared to exhibit pCREB-ir as well. Water deprivation markedly increased, and rehydration decreased, NADPH-d/pCREB neurons both in the pM- and in the mP-PVN. Gel shift assay demonstrated that dehydration may promote CREB binding to nNOS promoter in the PVN neurons. Significant amounts of NADPH-d-stained neurons in the PVN of water-deprived rats (67-68% in both the mP and the pM) exhibited c-Fos-ir. NADPH-d/c-Fos neurons in the pM-PVN were increased by water deprivation but not changed by rehydration. NADPH-d/c-Fos double-stained neurons in the mP-PVN did not significantly change depending on different water conditions. These results suggest that pCREB may play a role in dehydration-induced nNOS gene expression in the PVN neurons, and c-Fos might not be implicated in the regulatory pathway.     

Development of a cone-shape phantom for multi-voxel MR spectroscopy

The purpose of this study was to develop a cone-shape phantom for multi-voxel magnetic resonance spectroscopy (MRS) and to evaluate MR spectra using the cone-shape phantom we developed in this study. A cone-shape MRS phantom was developed with a combination of cone-shape vials. The cylindrical main body was made of acrylic resin and the cone-shape vials were fabricated from poly-ethylene cones. Each cone of the phantom was filled with various metabolite materials. 1.5T GE and 3T Philips systems were used for the single voxel spectroscopy (SVS) as well as for the multi-voxel spectroscopy (MVS). Identification and quantification of the metabolite materials in the cone-shape phantom were done by the SAGE post-program. The MR images and spectra of the cone-shape phantom were obtained from the assigned slice position. The high order shimming control provided enhanced resolution in the SVS and MVS. The area and amplitude were proportional to the metabolite volume in the voxel. The present study demonstrated that the cone-shape phantom was useful for the metabolite quantification. Thus, we propose that the cone-shape phantom can be used for the evaluation of quality control of the MR spectra obtained from SVS and MVS.     

A non-parametric approach for co-analysis of multi-modal brain imaging data: application to Alzheimer's disease

We developed a new flexible approach for a co-analysis of multi-modal brain imaging data using a non-parametric framework. In this approach, results from separate analyses on different modalities are combined using a combining function and assessed with a permutation test. This approach identifies several cross-modality relationships, such as concordance and dissociation, without explicitly modeling the correlation between modalities. We applied our approach to structural and perfusion MRI data from an Alzheimer's disease (AD) study. Our approach identified areas of concordance, where both gray matter (GM) density and perfusion decreased together, and areas of dissociation, where GM density and perfusion did not decrease together. In conclusion, these results demonstrate the utility of this new non-parametric method to quantitatively assess the relationships between multiple modalities.     

Surface modification of and selective protein attachment to a flexible microarray pattern using atmospheric plasma with a reactive gas

The hydrophobic and hydrophilic properties of the surface of poly-ether sulfone (PES) films were controlled by an atmospheric pressure plasma (AP) treatment using reactive gases (Ar/H₂ and Ar/O₂). The surface properties of the Ar/H₂ and Ar/O₂ in series AP-treated PES films showed higher surface roughness (～120%), surface energy (～30%) and hydrophilic properties (oxygen content ～10%) than the Ar/O₂ AP-treated PES film. The protein staining results confirmed that an activated region on the patterned PES film with high selectivity and sensitivity was well-defined and formed. This method is suitable for fabricating flexible protein adhesive chips with uniform biomolecular adhesive properties.