NUDT15 R139C causes thiopurine-induced early severe hair loss and leukopenia in Japanese patients with IBD.

The efficacy of thiopurines, including azathioprine (AZA) and 6-mercaptopurine (6MP), has been demonstrated for the treatment of inflammatory bowel disease (IBD). The most common and serious adverse event of treatment with thiopurines altered by doctors is leukopenia. Hair loss is also a serious event that could be a critical reason for patients to decline thiopurine treatment. Thiopurine-induced severe hair loss causes cosmetic problems, and it takes a long time to recover. In a recent study, NUDT15 R139C was strongly associated with thiopurine-induced leukopenia in Korean and Caucasian populations. In this study, we performed an association study to investigate and replicate the association of R139C with adverse events of thiopurines in Japanese patients. A total of 142 Japanese patients with IBD, with histories of thiopurine treatment, were examined. NUDT15 R139C was genotyped using a custom TaqMan genotyping assay. Adverse events including leukopenia were reviewed from medical records. The 6MP dose was adjusted to AZA equivalents by multiplying with 2 as a thiopurine dose. Five patients developed severe hair loss and all of them were risk homozygous (T/T) for R139C. No early severe hair loss was observed in patients with the C/T or C/C genotype (P=3.82 × 10(-16), odds ratio=212). The association of R139C with early (<8 weeks) leukopenia (white blood cells<3000 mm(-3)), which was previously reported in Korean patients, was replicated in our Japanese IBD cohort (P=1.92 × 10(-16), odds ratio=28.4). However, we could not confirm the association with late leukopenia in the Japanese subjects. Patients with the C/T genotype discontinued treatment or required thiopurine dose reduction significantly earlier than patients with the C/C genotype (P=1.45 × 10(-4)); however, on manipulating the doses, there was no significant difference in the thiopurine continuation rates between the groups. In the maintenance period, the frequencies of 6MP usage were higher, and the doses of thiopurines were significantly lower in patients with the C/T genotype than in those with the C/C genotype (0.574±0.316 mg kg(-1) per day vs 1.03±0.425 mg kg(-1) per day, P=6.21 × 10(-4)). NUDT R139C was significantly associated with early severe hair loss in Japanese patients with IBD. We also verified the previously reported association of R139C with early leukopenia in a different East Asian population. It is recommended that treatment with thiopurines should be avoided for patients with the T/T genotype. Low-dose 6MP (0.2-0.3 mg kg(-1) per day) could be used rather than AZA for the patients with C/T genotype to continue thiopurine treatments. However, late leukopenia and other several adverse events could not be completely predicted by R139C genotypes.

HLA-B is the best candidate of susceptibility genes in HLA for Japanese ulcerative colitis.

Recently, a genome-wide association study for ulcerative colitis (UC) in the UK population was reported, and several susceptibility loci including the human leukocyte antigen (HLA) region were identified. The strongest association in the HLA region was found at a 400 kb haplotype block containing HLA-DRB1. In Japanese population, previous study suggested the association between UC and HLA-B*52; however, HLA typing was determined using serotyping with the small sample size. The purpose of this study was to perform an association study in HLA-B by genotyping. A total of 320 patients with UC and 322 healthy controls were recruited in this case-control study. All subjects were Japanese. Genotyping of HLA-B was performed by polymerase chain reaction using a sequence-specific primer. When the allele frequencies were compared, significant associations were found with B*52 [odds ratio (OR) = 3.65, P = 1.6 x 10(-17), P(c) = 3.7 x 10(-16)] and B*4002 (OR = 0.52, P = 0.00030, P(c) = 0.0068). The allele frequency of B*52 was significantly higher in patients diagnosed before 40 years of age than in those diagnosed after 40 years (OR = 1.79, P = 0.010, P(c) = 0.020). A combination association map of Japanese UC using our current and previous studies showed two equal peaks of association on HLA-DRB1 and HLA-B, indicating the possible existence of two casual variants in the HLA region inside and outside the 400 kb block found in UK. We conclude that HLA-B contributes to the susceptibility to Japanese UC, especially cases with younger age of onset. The strength of association for HLA-B was equal to that for HLA-DRB1 in Japanese UC, in contrast to the UK population.

Effectiveness of an 'half elemental diet' as maintenance therapy for Crohn's disease: A randomized-controlled trial.

BACKGROUND: Although thiopurines have a proven role in maintenance therapy for Crohn's disease, an alternative therapy is needed for patients intolerant or resistant to thiopurines. AIM: To evaluate the effectiveness of home enteral nutrition as a maintenance therapy regimen in which half of the daily calorie requirement is provided by an elemental diet and the remaining half by a free diet. We refer to this home enteral nutrition therapy as 'half elemental diet'. METHODS: Between 2002 and 2005, 51 patients in remission from two hospitals were randomly assigned to a half elemental diet group (n = 26) or a free diet group (n = 25). The primary outcome measure of this study was the occurrence of relapse over the 2-year period. RESULTS: The relapse rate in the half elemental diet group was significantly lower [34.6% vs. 64.0%; multivariate hazard ratio 0.40 (95% CI: 0.16-0.98)] than that in the free diet group after a mean follow-up of 11.9 months. Compliance was similar in the two groups. No adverse event occurred in any of the patients throughout the study. CONCLUSION: This randomized-controlled trial shows the effectiveness of an half elemental diet, which is a promising maintenance therapy for Crohn's disease patients.

Tracking the states of a nonlinear and nonstationary system in the weight-space of artificial neural networks.

We propose a novel interpretation and usage of Neural Network (NN) in modeling physiological signals, which are allowed to be nonlinear and/or nonstationary. The method consists of training a NN for the k-step prediction of a physiological signal, and then examining the connection-weight-space (CWS) of the NN to extract information about the signal generator mechanism. We define a novel feature, Normalized Vector Separation (gamma(ij)), to measure the separation of two arbitrary states "i" and "j" in the CWS and use it to track the state changes of the generating system. The performance of the method is examined via synthetic signals and clinical EEG. Synthetic data indicates that gamma(ij) can track the system down to a SNR of 3.5 dB. Clinical data obtained from three patients undergoing carotid endarterectomy of the brain showed that EEG could be modeled (within a root-means-squared-error of 0.01) by the proposed method, and the blood perfusion state of the brain could be monitored via gamma(ij), with small NNs having no more than 21 connection weight altogether.

Growth of human cultured cells exposed to a non-homogeneous static magnetic field generated by Sm-Co magnets.

A static magnetic field, with a strong spatial gradient, was established on the surface of cell culture dishes by use of a gilded iron needle set vertically above an Sm-Co magnet. The calculated magnetic flux density was more than 1.5 T at the center of the needle tip, and the products of the flux density and its gradient were about 200 and 60 T2/m at distances of 0.1 and 0.3 mm, respectively, from the center. The DNA content, DNA synthesis and labeling index of cultured cells located within 0.1 mm from the center of the needle, and the growth rate of cells located within 0.3 mm from the center, were measured. HeLa cells grew at a normal rate for 96 h in the magnetic field and showed no significant change in shape, detectable by scanning electron microscopy. The growth of HeLa cells was not influenced by exposure to the magnetic field. Similarly, exposure for 48 h to the magnetic field had no effect on growth of normal human gingival fibroblasts (Gin-1). The DNA content, assayed by microfluorometry of the nuclei of both types of cells stained by the Feulgen reaction, was not significantly different from that of controls. Moreover, exposure to the magnetic field had no effect on DNA synthesis or the labeling index of HeLa cells assayed by autoradiography of incorporated [3H]thymidine. It is concluded that a non-homogeneous magnetic field of the intensity and the gradient used in this study does not significantly influence the growth of HeLa cells or Gin-1 cells.

Effects of seven months' exposure to a static 0.2 T magnetic field on growth and glycolytic activity of human gingival fibroblasts.

Human gingival fibroblasts in confluent cultures were continuously exposed to a static 0.2 T magnetic field for 6 or 8 months. Culture flasks were not changed during the exposure, but culture medium was renewed. After dilution and mixing of the cultures surviving intact, field-exposed and sham-exposed cultures received further field- or sham-exposure on Sm-Co blocks. Rate of cell proliferation, histogram of the nuclear DNA content, rates of lactate production and glucose consumption and the ATP content were determined and cell morphology was investigated by both light- and electron-microscopy. Results show no marked differences between exposed and control cells.

Effects of a time-varying strong magnetic field on transient increase in cytosolic free Ca2+ induced by bradykinin in cultured bovine adrenal chromaffin cells.

We tested the effects of exposure to a time-varying magnetic field changing between 0.07 and 1.7 T at an interval of 3 s on transient increase in intracellular Ca2+ stimulated by bradykinin in bovine adrenal chromaffin cells. Addition of bradykinin induced the increase in intracellular Ca2+ within a few minutes. The exposure to the magnetic field perfectly suppressed the increase in intracellular Ca2+ in Ca2+-free medium. The inhibition occurred for 15 min when the maximum magnetic flux density was more than 1.4 T. These results suggest that the exposure inhibits Ca2+ release from intracellular Ca2+ stores.

Effect of intravenously infused eicosapentaenoic acid on the leukotriene generation in patients with active Crohn's disease.

Ten patients with active Crohn's disease who have been managed with parenteral-nutrition therapy were administered a lipid emulsion either with [containing 0.6 g eicosapentaenoic acid (EPA)] or without fish oil for 2 wk. We isolated polymorphonuclear leukocytes (PMNLs) from the patients before and after this treatment and measured the amounts of leukotriene B4 (LTB4) and leukotriene B5 (LTB5) generated by activated PMNLs by reversed-phase HPLC. The LTB5 generation in active Crohn's disease before this treatment was significantly lower than in healthy control subjects. The amount of LTB5 and the LTB5-LTB4 ratio increased significantly after fish-oil supplementation. The difference with LTB4 was not statistically significant. We have shown that daily intravenous administration of 0.6 g EPA influenced the generation of leukotrienes in active Crohn's disease even after short-term treatment. Further investigations are necessary to clarify the correlation between EPA and clinical improvement in Crohn's disease.

Relaxation of imprinting of the insulin-like growth factor II gene in colorectal cancer.

The insulin-like growth factor II gene (IGF2) is imprinted in normal human tissues, and relaxation of imprinting (ROI) of IGF2 is thought to play an important role in human childhood tumors. Taking advantage of an Apa I polymorphism in this gene, allelic expression of IGF2 has now been examined in colorectal cancer. Thirteen of 33 patients studied were informative. Colorectal cancer tissue from 5 of the 13 informative patients exhibited ROI of IGF2; furthermore, normal mucosa from 3 of these 5 patients also showed weak biallelic expression of IGF2. ROI of IGF2 may thus also play a role in colorectal cancer.

Application of electrical impedance analysis for diagnosis of a pulmonary mass.

The electrical impedance of a pulmonary mass was measured in 53 patients of whom 44 had primary lung cancer, 5 had metastatic lung tumor, and 4 had organizing pneumonia. Because biologic tissue can be regarded, electrically, to consist of extracellular resistance (Re), intracellular resistance (Ri), and the electrical capacitance of the cell membrane (Cm), these three parameters were calculated from the measured electrical impedance of tissue by a curve-fitting technique using a computer program. The Re of lung tissue was significantly greater (p < 0.01) and the Cm of lung tissue was significantly less (p < 0.01) than that of a pulmonary mass. The Re of malignant tumors (both lung cancer and metastatic tumors) was significantly greater (p < 0.01) and the Cm of malignant tumors was significantly less (p < 0.01) than that of organizing pneumonia. With this information, we used a biopsy needle to diagnose nine intrathoracic lesions. This technique additionally allowed us to confirm the proximity of the needle tip of the mass. The electrical impedance of the lung mass was measured through the biopsy needle using a modified impedance analysis system before the biopsy was performed. There were no false-negative results, and one false-positive result. The rapid measurement of the electrical impedance of a pulmonary mass, preoperatively, may be of value in the clinical evaluation of a pulmonary mass both by facilitating needle guidance and by permitting diagnosis based on electrical impedance.

Leukotriene B4 omega-hydroxylase activity in polymorphonuclear leukocytes from patients with inflammatory bowel disease.

omega-oxidation is regarded as the major pathway for the catabolism of leukotriene B4 (LTB4). To determine how LTB4 omega-hydroxylase is modulated in inflammatory bowel disease, we investigated the kinetic characteristics of this enzyme in 10 patients with Crohn's disease (CD), nine with ulcerative colitis (UC) and eight healthy control subjects. After incubating polymorphonuclear leukocytes with various concentrations of 3H-labeled LTB4, omega-oxidation products were separated by high performance liquid chromatography (HPLC) and the radioactivity was measured by a liquid scintillation counter. The apparent Vmax values were significantly higher in both disease than in healthy control subjects, although the difference between CD and UC was insignificant. There was no difference in the apparent Km values. And the Vmax/Km ratios of patients with CD were significantly higher than that of healthy control subjects. It is suggested that LTB4 metabolism is activated in inflammatory bowel disease (IBD) and that the modulation of this enzyme activity has an important role in the pathogenesis of inflammatory bowel disease.

5-Aminosalicylic acid inhibits leukotriene B4 omega-hydroxylase activity in human polymorphonuclear leukocytes.

omega-Oxidation is regarded as the major pathway for the metabolism and inactivation of leukotriene B4 (LTB4). To investigate the action of 5-aminosalicylic acid (5-ASA) on LTB4 omega-hydroxylase activity, we incubated human polymorphonuclear leukocytes (PMNLs) with 3H-labeled LTB4 after pre-incubation with various concentrations of 5-ASA. omega-oxidation metabolites were separated by high performance liquid chromatography and each radioactivity was measured by a liquid scintilation counter. LTB4 omega-hydroxylase activity was inhibited by 5-ASA in a concentration-dependent fashion. The 50% inhibitory dose was about 50 mumol/l, which is within the concentration range found in the colonic mucosa. Our findings may be valuable in elucidating the potentially critical aspect of 5-ASA treatment in ulcerative colitis (UC).

Studies on the Sm-Co magnet as a dental material.

The Sm-Co magnet has superior and convenient magnetic properties as compared with conventional ones used hitherto in prosthesis, and even very small pieces can provide the force necessary in dentistry. Also, the magnet has high corrosion resistance and is innocuous to tissues. Therefore, it can be used as a dental material, overcoming the limitations in past applications.

Pd-Co dental casting ferromagnetic alloys.

Three kinds of Pd-Co alloys have been newly developed. Their magnetic and physical properties and corrosion resistances have been examined. As a result, it was found that they are available as the dental casting ferromagnetic alloy which can be used in combination with Sm-Co magnets, overcoming such problems as non-castability and brittleness.

Telomere shortening in the colonic mucosa of patients with ulcerative colitis.

Telomere length in human somatic cells gradually decreases with the number of cell divisions and is regarded as a marker of somatic cell turnover. Mucosal cells of the affected colon show rapid turnover in individuals with active ulcerative colitis (UC). Telomere length was determined by Southern blot analysis of terminal restriction fragments (TRFs) from the colonic mucosa of 17 patients with UC in remission, two of whom showed dysplasia, and 17 control subjects without colitis. For each individual, mean TRF length was compared between rectal mucosa and unaffected cecal mucosa. The mean TRF length of the rectal mucosa was significantly less than that of cecal mucosa in UC patients (7.87 +/- 0.36kb versus 8.77 +/- 0.21 kb; P = 0.0015, Wilcoxon signed rank test), whereas no significant difference was detected in the control subjects. The extent of telomere shortening was 10.6 +/- 3.35% in UC patients, compared with 0.8 +/- 0.64% in noncolitis controls (P = 0.0024, Mann-Whitney U-test). Four UC patients, two of whom had dysplasia, showed telomere shortening of more than 20% in the rectal mucosa. These observations suggest that telomere shortening in the colonic mucosa of individuals with UC may represent the history of mucosal inflammation during disease of long duration, and that it may contribute to aneuploidy in UC.

Noninvasive measurement of the electrical bioimpedance of breast tumors.

The purpose of this study was to evaluate the possibility of differential diagnosis of tumors, such as breast cancer, by measuring the mammary electrical bioimpedance via the skin surface noninvasively and by examining the relationship between the tissue structure of the breast and electrical bioimpedance. The mammary electrical bioimpedance was measured in 24 patients with breast cancer. Taking into account the measurement results and the distribution of the mammary glands and fatty tissue, a breast model with tumors was proposed. Based on this model, the distributions of the electric potential and electric field in the tissue were theoretically analyzed by the three-dimensional finite element method. In clinical cases, the Re values of the diseased breast were significantly larger than those of the contralateral healthy breast. In theoretical analysis based on the breast model, the Re value of mammary electrical bioimpedance varied due to the structure of the breast, that is, the ratio of fatty tissue to mammary gland and the presence of mammary tumors. The results of the measurement agreed with the theoretical analyses. These results suggest that differential diagnosis of breast tumors is possible by measuring the mammary electrical bioimpedance using noninvasive electrodes on the skin.

A new method for noninvasive measurement of multilayer tissue conductivity and structure using divided electrodes.

This paper outlines a new method for measuring multilayer tissue conductivity and structure by using divided electrodes, in which current electrodes are divided into several parts. Our purpose is to estimate the multilayer tissue structure and the conductivity distribution in a cross section of the local tissue by using bioresistance data measured noninvasively. The effect of the new method is assessed by computer simulations using a typical two-dimensional (2-D) model. In this paper, the conductivity distribution in the model is analyzed based on a finite difference method (FDM) and a steepest descent method (SDM). Simulation results show that the conductivity values of skin, fat, and muscle layers can be estimated with an error of less than 0.1%. When random noise at various levels is added to the measured resistance values, estimates of the conductivity values for skin, fat, and muscle layers are still reasonably precise: their root mean square errors are about 1.06%, 1.39%, and 1.61% for 10% noise. In a 2-D model, increasing the number of divided electrodes permits simultaneous estimates of tissue structure and conductivity distribution. Optimal configuration for divided electrodes is examined in terms of dividing pattern.

Effects of 9-(1,3-dihydroxy-2-propoxymethyl) guanine (DHPG) eye drops and cyclosporine eye drops in the treatment of herpetic stromal keratitis in rabbits.

The effect of 9-(1,3-dihydroxy-2-propoxymethyl) guanine (ganciclovir, DHPG) eye drops and the anti-inflammatory effect of cyclosporine (CYA) eye drops on experimental herpetic stromal keratitis in rabbits with herpes simplex virus (HSV) were studied. Ten rabbits were presensitized by subcutaneous injection of HSV, type 1, on days 14 and 7 before intrastromal inoculation of the same virus. These rabbits were divided into 2 groups and treatment was started 48 hours after virus inoculation. The eye drops used were 0.1% DHPG, 0.1% CYA or the vehicles of these eye drops. Eye drops were given 5 times a day and eyes were scored every day for 3 weeks after inoculation. The right eyes of Group 1 were treated with 0.1% DHPG and 0.1% CYA eye drops, and the left eyes with 0.1% DHPG and the vehicle of CYA eye drops. The right eyes of Group 2 were treated with 0.1% CYA and the vehicle of DHPG eye drops, and the left eyes with the vehicles of CYA and DHPG eye drops. The combination of DHPG and CYA was the most effective in decreasing the severity of herpetic stromal keratitis. Treatment with DHPG alone was also effective, but CYA alone was less effective.