Production of a monoclonal antibody against a galactose-binding protein of Acanthamoeba castellanii and its cytotoxicity.

In this study, it was confirmed whether the galactose-binding protein (GBP) was present in Acanthamoeba castellanii, and its function on a target cell was confirmed by production of an antibody against the GBP. Since the genes for GBP have not yet been identified at all, the purification of GBP was done using galactose-beads from amoebial lysates, and monoclonal antibodies were produced using cell fusion. GBP was confirmed to have a size of about 35 kDa. After the third immunization with purified GBP in BALB/c mice, monoclonal antibody production was analyzed. The clone cultured before limiting dilution was named 2AB2 and showed the highest antibody titer in the culture supernatant of a 24-well plate. AF6 clone cultured after limiting dilution showed an antibody titer of 0.259 in a 75-T flask. Antibodies generated by collecting ascites by injecting monoclonal colonies into the abdominal cavity of mice were confirmed through gel analysis and were observed to belong to the isotype of the IgM having kappa chains. Since the cytotoxicity of A. castellanii was inhibited by about 26% by the monoclonal antibody against GBP, it was confirmed that the antibody against GBP had an inhibitory effect on cytotoxicity. This study was the first report on GBP isolated and purified from A. castellanii, and similarly to a mannose-binding protein (MBP), its involvement in contact-dependent cytotoxicity was demonstrated with monoclonal antibody production.

Cross-evaluation of facial hyperpigmented lesions based on fluorescence color image and cross-polarized color image.

BACKGROUND/PURPOSE: Hyperpigmentation is a common skin problem that looks darker than normal skin regions. Accurate evaluation of a hyperpigmented lesion (HPL) is of clinical importance because proper choice of treatment can be dependent on it. This study aimed to differentiate between epidermal and dermal HPLs. METHODS: Cross-polarized color images (CPCIs) and fluorescence color images (FCIs) were acquired from the same facial regions. Contrast-limited adaptive histogram equalization (CLAHE) was employed to enhance the image contrast and a fuzzy c-means algorithm was implemented to extract the HPLs. The HPLs were superimposed to investigate the difference between CPCI and FCI. RESULTS: The HPL was successfully extracted by applying both CLAHE and fuzzy c-means algorithms. CPCI and FCI resulted in a slightly different HPL, even from the same facial region, indicating a greater percentage area of HPL in FCI than CPCI. CONCLUSION: CPCI and FCI may be utilized to differentiate HPLs that exist in different skin layers. Thus, this approach may contribute to the effective treatment of HPLs.

Changes in heart rate variability after adenotonsillectomy in children with obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular morbidity and mortality, and increased sympathetic activity is considered to be a causative link in this association. Higher levels of sympathetic activity have been reported in children with OSAS. Sympathetic predominance is indicated on heart rate variability (HRV) analysis by increased heart rate (HR) and a higher ratio of low-frequency to high-frequency band power (LF/HF). Improvement in OSAS after adenotonsillectomy (AT) in children with OSAS could, therefore, be associated with reduced HR and reduced LF/HF. METHODS: Changes in HR and time and frequency components of HRV were retrospectively analyzed in 2-min epochs free of respiratory events during light, deep, and rapid-eye-movement (REM) sleep in children with OSAS who underwent polysomnography before and after AT. RESULTS: Eighteen children with OSAS, aged 4.9 ± 2.4 years (mean ± SD) were studied. After AT, the apnea-hypopnea index decreased from 31.9 ± 24.8 events/h to 4.1 ± 3.7 events/h. The HR decreased after AT in all stages of sleep (99.8 ± 16.9 beats/min to 80.7 ± 12.9 beats/min [light sleep]; 100.2 ± 15.4 beats/min to 80.5 ± 12.4 beats/min [deep sleep)]; and 106.9 ± 16.4 beats/min to 87.0 ± 12.1 beats/min [REM sleep]), as did the LF/HF (1.6 ± 2.7 to 0.6 ± 0.5 [light sleep]; 1.2 ± 1.6 to 0.5 ± 0.6 [deep sleep]; and 3.0 ± 5.4 to 1.4 ± 1.7 [REM sleep]). CONCLUSIONS: The proportion of sympathetic activity of the autonomic nervous system declines in children with OSAS after AT in association with improvement in sleep-disordered breathing.

Regularization of DT-MR images using a successive Fermat median filtering method.

Tractography using diffusion tensor magnetic resonance imaging (DT-MRI) is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of greatest diffusion in the white matter of the brain. To reduce the noise in DT-MRI measurements, a tensor-valued median filter, which is reported to be denoising and structure preserving in the tractography, is applied. In this paper, we proposed the successive Fermat (SF) method, successively using Fermat point theory for a triangle contained in the two-dimensional plane, as a median filtering method. We discussed the error analysis and numerical study about the SF method for phantom and experimental data. By considering the computing time and the image quality aspects of the numerical study simultaneously, we showed that the SF method is much more efficient than the simple median (SM) and gradient descents (GD) methods.

A study on the comparison of median filter regularization methods in diffusion tensor MRI.

Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) is a method which makes it possible to study non-invasively the architecture of axonal fibers in the central nervous system. Since eigenvectors obtained from DT-MRI usually contain noise, the calculated vector directions may be deviated from the real fiber orientation. Therefore, noise errors can be accumulated as fiber tract becomes longer in tractography of DT-MRI. We used three algorithms for computing matrix medians which are the Simple Median Method, the Gradient Descent Method, and the Successive Fermat Method, because matrix-valued median filters show excellent capabilities for structure-preserving denoising. The results of the Successive Fermat Method give better than those of the Simple Median Method and is faster and the performance is similar to those of the Gradient Descent Method.

Lossless compression of volumetric medical images with improved three-dimensional SPIHT algorithm.

This article presents a lossless compression of volumetric medical images with the improved three-dimensional (3-D) set partitioning in hierarchical tree (SPIHT) algorithm that searches on asymmetric trees. The tree structure links wavelet coefficients produced by 3-D reversible integer wavelet transforms. Experiments show that the lossless compression with the improved 3-D SPIHT gives improvement about 42% on average over two-dimensional techniques and is superior to those of prior results of 3-D techniques. In addition, we can easily apply different numbers of decomposition between the transaxial and axial dimensions, which is a desirable function when the coding unit of a group of slices is limited in size.