The Tohoku Journal of Experimental Medicine
Online ISSN : 1349-3329
Print ISSN : 0040-8727
ISSN-L : 0040-8727
Volume 220 , Issue 2
February
Showing 1-10 articles out of 10 articles from the selected issue
Invited Review for the 90th Anniversary
  • Takeshi Tabira
    2010 Volume 220 Issue 2 Pages 95-106
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Based on the amyloid cascade hypothesis, various strategies targeting amyloid β protein (Aβ) have been invented for prevention and treatment of Alzheimer disease (AD). Active and passive immunizations with Aβ and Aβ antibodies successfully reduced AD pathology and improved cognitive functions in an AD mouse model. However, active immunization with AN-1792, a mixture of Aβ1-42 peptide and adjuvant QS21 induced autoimmune encephalitis in humans. Surprisingly, although AN-1792 cleared senile plaque amyloid, it showed no benefit in humans. It is speculated that AN-1792 failed in deleting more toxic forms of Aβ such as oligomers and intracellular Aβ, suggesting that newly developing vaccines should delete these toxic molecules. Since T cell epitopes exist mainly in the C-terminal portion of Aβ, vaccines using shorter N-terminal peptides are under development. In addition, since T helper 1 (Th1) immune responses activate encephalitogenic T cells and induce continuous inflammation in the central nervous system, vaccines inducing Th2 immune responses seem to be more promising. These are N-terminal short Aβ peptides with Th2 adjuvant or Th2-stimulating molecules, DNA vaccines, recombinant viral vector vaccines, recombinant vegetables and others. Improvement of vaccines will be also achieved by the administration method, because Th2 immune responses are mainly induced by mucosal or trans-cutaneous immunizations. Here I review recent progress in active immunization strategies for AD.
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Regular Contributions
  • Bhagyalakshmi Sridhar, Nagaraja Haleagrahara, Ramesh Bhat, Anupama Ban ...
    2010 Volume 220 Issue 2 Pages 107-113
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Autonomic neuropathy in diabetes leads to impaired regulation of blood pressure and heart rate variability (HRV), which is due to a shift in cardiac autonomic balance towards sympathetic dominance. Lower HRV has been considered a predictor of cardiac mortality and morbidity. Deep breathing test is a simple method to measure HRV and it provides a sensitive measure of cardiac autonomic function. The effect of long-term physical activity on HRV in type-2 diabetes mellitus is inconclusive. We aimed to evaluate the effects of regular physical exercise on HRV with deep breathing in type 2 diabetes (n = 105). Thirty normotensive diabetic patients and 25 hypertensive diabetic patients underwent physical exercise program for 12 months, and the other 50 patients (22 normotensive and 28 hypertensive diabetic patients) were considered the non-exercised group. Electrocardiogram was recorded during deep breathing and HRV was measured. Regular exercise significantly increased HRV in diabetic patients with and without hypertension. The degree of the increase in HRV was greater in hypertensive diabetic patients (p < 0.01) than in normotensive diabetic patients (p < 0.05). After exercise, glycosylated hemoglobin levels were decreased in both groups of diabetic patients. Moreover, the hypertensive diabetic patients showed a decrease (p < 0.05) in blood pressure after regular exercise. Thus, regular exercise training increases HRV, suggesting that there is a shift in the cardiac sympathovagal balance in favor of parasympathetic dominance in diabetic patients. Long-term physical training may be an effective means to reverse the autonomic dysregulation seen in type 2 diabetes.
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  • Olivera Miloševic-Djordjevic, Darko Grujicic, Zeljko Vaskovic, ...
    2010 Volume 220 Issue 2 Pages 115-120
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Chromosomal instability could be one of primary causes for malignant cell transformation. The objective of the present study was to evaluate the spontaneous genetic damages in circulated lymphocytes of newly diagnosed cancer patients by using cytokinesis-block micronucleus (CBMN) assay, with respect to the factors that might affect micronucleus frequency (i.e. age, gender, smoking habits and cancer sites). Micronuclei (MN) are small nuclei that are originated from chromosome fragments or whole chromosomes. The analyzed samples included 44 untreated cancer patients (19 females and 25 males with mean age of 60.89 years) with different cancer sites (12 patients with breast cancer, 5 with uterine cancer and 27 with cancer of pharynx). Control group included 40 healthy donors (28 females and 12 males with mean age of 43.95 years). The mean baseline MN frequency was significantly higher (p < 0.001) in cancer patients (15.18 ± 5.05 MN/1000 BN cells ranging from 4 to 27) than the baseline frequency in healthy controls (6.45 ± 2.75 MN/1000 BN cells, ranging from 1 to 11). There was no gender difference in baseline MN frequency in cancer patients and healthy controls. Moreover, the MN frequency did not significantly differ among cancer sites, and between smokers and non-smokers in both patient and control samples. In conclusion, untreated cancer patients may be associated with an increase of chromosomal instability in peripheral blood lymphocytes, irrespective of gender, cigarette smoking and cancer sites.
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  • Toshihiko Ando, Noriyuki Mitani, Kimie Matsunaga, Tatsuki Nakazora, To ...
    2010 Volume 220 Issue 2 Pages 121-126
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    The treatment of isolated extramedullary relapse (IEMR) after allogeneic hematopoietic stem-cell transplantation (allo-HSCT) poses a challenge for which no standard approach exists. Gemtuzumab ozogamicin (GO) is a recombinant humanized monoclonal antibody, conjugated to calicheamicin, which targets the CD33 antigen that is expressed in acute myelogenous leukemia (AML) blasts. The selectivity of GO for CD33-positive leukemic cells makes it an attractive agent for use in patients with multiple sites of IEMR after allo-HSCT, because GO does not suppress cells responsible for the putative graft-versus-leukemia (GVL) effect. Herein, we describe a 54-year-old male patient who developed AML with multiple sites of extramedullary (EM) relapse after allo-HSCT, and who exhibited apparent donor-derived hematopoiesis in the bone marrow. At approximately 120 days after allo-HSCT, the patient complained of severe lumbago. T2-weighted magnetic resonance images and fluorodeoxyglucose-positron emission tomography showed multiple mass lesions in soft tissue and bone. A biopsy specimen from a lumbar soft tissue mass confirmed EM relapse, and revealed that donor T lymphocytes were present in the relapse site and that leukemic cells expressed CD33. Therefore, to maintain the GVL effect of donor T lymphocytes, the patient was treated with GO as a single agent. He achieved complete hematological remission, and has remained in remission, with only mild liver injury, for more than 10 months since GO treatment. GO can be an effective therapy for IEMR after allo-HSCT, especially when cytotoxic T lymphocytes react to leukemic cells at the site of EM relapse.
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  • Kibom Kim, Norio Suzuki, Kinuko Ohneda, Naoko Minegishi, Masayuki Yama ...
    2010 Volume 220 Issue 2 Pages 127-138
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Eosinophils contribute to the pathophysiology of allergic and infectious diseases, albeit their molecular functions remain unknown. Mature eosinophils are identified by their unique morphology and staining characteristics. However, it is difficult to fractionate living eosinophils by flow cytometry because these granulocytes express multiple cell surface markers that are shared by other cells of hematopoietic or non-hematopoietic origin. In this study, we describe a flow cytometry-based method to enumerate and fractionate eosinophils by developmental stages. To fractionate these cell types, we used transgenic mouse lines that express fluorescent proteins under control of the Gata1 gene hematopoietic regulatory region (Gata1-HRD), which is exclusively active in Gata1-expressing hematopoietic cells, including eosinophils. As expected, mature eosinophils were highly enriched in the fluorescent reporter-expressing subfraction of bone marrow myeloid cells that were negatively selected by using multiple antibodies against B220, CD4, CD8, Ter119, c-Kit and CD71. Cytochemical analyses of flow-sorted cells identified the cells in this fraction as eosinophils harboring eosinophilic granules. Additionally, expression of eosinophil-specific genes, for instance eosinophil enzymes and the IL-5 receptor alpha gene, were specifically detected in this fraction. The expression of these eosinophil-specific genes increased as the cells differentiated. This method for enrichment of bone marrow eosinophils is applicable to fractionation of eosinophils and bronchoalveolar lavage fluid from transgenic mice with atopic asthma. Thus, both pathological and developmental stages of eosinophils are efficiently fractionated by this flow cytometry-based method using Gata1-HRD transgenic reporter mice. This study, therefore, proposes a useful means to study the experimental allergic and inflammatory systems.
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  • Xiaojun Cui, Haijie Wang, Haidong Guo, Cun Wang, Hong Ao, Xiaoqin Liu, ...
    2010 Volume 220 Issue 2 Pages 139-147
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Myocardial infarction (MI) causes myocardium injury and scar formation, and the transmural infarction is associated with ventricular hypofunction. Stem cell transplantation therapy has improved cardiac function in animal models of MI. However, the poor survival of the donor cells in the host myocardium hampers the therapeutic efficacy of stem cell transplantation. Diazoxide, a mitochondrial ATP-sensitive potassium channel opener, has been applied to suppress cell apoptosis and promote cell survival. We therefore assessed the effects of diazoxide on the selected mesenchymal stem cells (SMSCs). Pretreatment of SMSCs with diazoxide (200 μmol/L) for 30 min protected cells from oxidative stress injury by upregulating the expression of basic fibroblast growth factor and hepatocyte growth factor mRNAs and phospho-Akt and by preventing mitochondral cytochrome c translocation into the cytoplasm. Expression of mRNAs and proteins was detected by RT-PCR and western blot analyses. Thirty min after establishment of MI (the ligation of the left anterior descending of coronary artery) in female rats, the male rat SMSCs preconditioned with diazoxide were injected at four sites on the edge of the infarcted area. At 4 weeks after cell tranplantation, the donor cells in the recipient myocardium were tracked with Y chromosome. Preconditioning with diazoxide improved the survival rate of the transplanted SMSCs, compared to the untreated SMSCs. Moreover, transplantation of the diazoxide-pretreated SMSCs reduced the infarct size and increased left ventricular function, as judged by transthoracic echocardiography. In conclusion, diazoxide preconditioning is effective to promote SMSCs survival under oxidative stress and attenuates cardiac injury in MI.
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  • Keiko Hyodo, Kazutoshi Nakamura, Mari Oyama, Osamu Yamazaki, Izumi Nak ...
    2010 Volume 220 Issue 2 Pages 149-155
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    A devastating earthquake causes psychological distress, and may increase suicide mortality thereafter, yet previous studies have made inconsistent conclusions regarding this issue. The purpose of the present study was to determine whether the 2004 Niigata-Chuetsu earthquake in Japan affected long-term mortality from suicide. We conducted a comparative study of suicide mortality rates during the 5-year period preceding and the 3-year period following the earthquake in the disaster area and a control area in Niigata Prefecture, by analyzing death certificate data from October 1, 1999, to September 30, 2007. In men, baseline suicide mortality rates (5 years preceding the earthquake) were 48.4 per 100,000 person-years in the disaster area and 46.1 in the control area, and suicide mortality rates during the 3-year period following the earthquake were 46.0 and 45.1, respectively. In women, baseline suicide mortality rates were 22.3 in the disaster area and 18.7 in the control area, and post-earthquake suicide mortality rates were 20.2 and 15.3, respectively. In consequence, the decrease in suicide mortality rate during the 3 years post-earthquake was significantly higher in the disaster area (2.5) than in the control area (1.0) (p = 0.0013) in men, whereas the decrease in suicide mortality rate was 2.1 in the disaster area and 3.0 in the control area (p = 0.1246) in women. We have concluded that the long-term mortality from suicide after the earthquake decreases in men and increases in women, suggesting that post-earthquake suicide mortality is sex-dependent. Post-earthquake suicide prevention strategies should more aggressively target women.
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  • Xi Huang, Xue-Ya Zhang, Feng Qin, Xiao-Yu Wang, Ping Ren, Zhao-Qian Li ...
    2010 Volume 220 Issue 2 Pages 157-163
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Guanxin II (GXII) is a traditional Chinese formula to treat coronary heart disease in China. Previous studies indicate cardioprotection of GXII are related to cardiomyocyte apoptosis. Akt is necessary and sufficient for inhibition of apoptosis in cardiomyocytes. Our aim was to examine whether or not the antiapoptotic mechanisms of GXII are related to the Akt pathway. Male Sprague-Dawley rats were randomly assigned to four groups: GXII administered at 2.5 or 0.5 g raw materials/kg, the vehicle control and sham-operated oral 0.9% NaCl. They were pretreated once a day for 15 consecutive days by gavage. Thirty min after the last administration, the left anterior descending coronary artery was occluded to induce myocardial ischemia except for the sham-operated rats. Compared with rats receiving vehicle, those rats pretreated with GXII at 2.5 g/kg significantly reduced infarct size and decrease apoptosis. Furthermore, GXII (2.5 g/kg) significantly activated Akt kinase, increased the Bcl-2/Bax ratio, inhibited cytochrome c release, reduced caspase-9 activation, and attenuated subsequent caspase-3 activation. GXII at 0.5 g/kg have no noticeable effect on these parameters. Meanwhile, GXII at 2.5 g/kg did not change myocardial blood flow of ischemic zone, indicating a direct action on cardiomyocytes. These results suggest GXII at 2.5 g/kg ensures the survival of myocardium by enhancing the Akt-mediated antiapoptosis pathway. The findings provide new evidence of the effective and safe therapy with GXII for patients with chronic coronary heart disease.
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  • Maiko Motoshima, Katsunori Yanagihara, Yoshitomo Morinaga, Junichi Mat ...
    2010 Volume 220 Issue 2 Pages 165-170
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Methicillin-resistant Staphylococcus aureus (MRSA) causes a wide range of infections in health care settings and community environments. In particular, community-acquired MRSA (CA-MRSA) is important for clinicians because many fatal cases in healthy populations have been reported. Staphylococcal cassette chromosome mec (SCCmec) is a mobile genetic element and carries the central determinant for broad-spectrum beta-lactam resistance encoded by the mecA gene. The emergence of MRSA is due to the acquisition and insertion of the SCCmec element into the chromosome. CA-MRSA is characterized as SCCmec type IV. Thus, we aimed to establish a novel multiplex real-time PCR method to distinguish SCCmec type, which enables us to evaluate the pathogenicity of MRSA. A total of 778 MRSA were isolated at Nagasaki University Hospital from 2000 to 2007. All isolates were subjected to minimal inhibitory concentration testing and PCR for SCCmec typing and detecting genes of toxins: tst (toxic shock syndrome toxin 1), sec (encoded enterotoxin type c), etb (exfoliative toxin type b), and lukS/F-PV (Panton-Valentine leukocidin). PCR was performed to amplify a total of 10 genes in the same run. The 667 MRSA clones detected from pus in 778 clones were classified as SCCmec type II (77.7%), type IV (19.2%), and type I (3.0%). 87.5% of SCCmec type II clone had tst and sec genes. No isolate was lukS/F-PV positive. The present study indicates the high rate of lukS/F-PV-negative SCCmec type IV in Nagasaki. Our PCR method is convenient for typing MRSA and detecting toxins in Japan.
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  • Sohtaro Mimasaka, Maki Ohtani, Naohito Kuroda, Shigeyuki Tsunenari
    2010 Volume 220 Issue 2 Pages 171-175
    Published: 2010
    Released: February 06, 2010
    JOURNALS FREE ACCESS
    Physical abuse of children is a severe social problem and is usually identified by the presence of bruises of various ages. The visual appearance of bruises is widely used to identify victims of abuse. Therefore, to objectively evaluate the age of bruises, we used a spectrophotometer to examine 86 bruises that occurred accidentally in healthy child volunteers, with consent from appropriate guardians. The bruise color was measured using a spectrophotometer and plotted using the CIE-L*a*b* color system, a method that expresses color numerically. The differences [Δ] in L* (lightness), a* (red and green content) and b* (yellow and blue content) color values relative to neighboring healthy/unbruised skin were measured for 7-10 days until the bruise disappeared. A characteristic pattern was observed in 21 bruises; ΔL* increased from the negative peak and returned to baseline, Δa* decreased from the positive peak to baseline, and Δb* increased above baseline and then slowly returned to baseline. The pattern of these color changes could be classified into three phases according to the time between bruising and the peak values for ΔL* (negative peak, 38.9 ± 19.5 hours), Δa* (positive peak, 37.6 ± 21.7 hours), and Δb* (negative and positive peak, 43.5 ± 18.7 and 132.6 ± 40.4 hours). Thus, spectrophotometric measurement of the color of bruises is helpful to estimate the approximate age of bruises and to distinguish between old and new bruises. This objective method could be introduced to clinical practice and social care to evaluate possible cases of child abuse.
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