The Tohoku Journal of Experimental Medicine
Online ISSN : 1349-3329
Print ISSN : 0040-8727
ISSN-L : 0040-8727
Volume 215 , Issue 4
August
Showing 1-12 articles out of 12 articles from the selected issue
Review
  • Yuan-Han Yang, Ching-Kuan Liu
    2008 Volume 215 Issue 4 Pages 295-298
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Dementia has been increasing exponentially in recent years, especially in Asia. This increasing prevalence calls for the necessity of antecedent biomarkers. The angiotensin-converting enzyme (ACE) gene, located on chromosome 17q23, has been regarded as a candidate susceptibility gene for Alzheimer's disease (AD), because ACE could degrade β-amyloid, the pathological hallmark of AD, thereby inhibiting its aggregation. The level and activity of ACE, in part, may be modulated by the insertion or deletion (indel) polymorphism of ACE gene. The indel polymorphism, consisting of the presence or absence of a 287-bp DNA fragment, has been considered the biomarker of AD, although its validity varies with race. In the Japanese, seemingly different results have been reported. One report shows significant association of insertion homozygote with AD, whereas other shows no association of indel polymorphism with AD. In the Taiwanese, the significant association of deletion homozygote with AD was found. Moreover, clinical studies have shown that using ACE inhibitors could slow the deterioration of cognitive function in AD patients, despite that ACE can degrade β-amyloid. These heterogeneous results on the association of ACE gene with AD and clinical significance of using ACE inhibitor in AD highlight the necessity of exploring detailed mechanisms from the ACE gene to the development of AD. These detailed mechanisms and findings may serve as the basis for further study.
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Regular Contributions
  • Yashiro Makiyama, Ken Toba, Kiminori Kato, Satoru Hirono, Takuya Ozawa ...
    2008 Volume 215 Issue 4 Pages 299-306
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Restenosis is a major problem in percutaneous catheter intervension (PCI) for coronary artery stenosis in patients with acute myocardial infarction. Coronary restenosis arises from intimal hyperplasia, i.e., hyperplasia of the vascular smooth muscle cells (SMCs) caused by endothelial cell (EC) damage due to PCI. Drug eluting stent (DES), a novel stent coated with a cell-growth inhibitor, such as rapamycin, has been utilized to block SMC proliferation, but DES also blocks EC repair and thus requires the administration of anti-platelets for a long time to prevent thrombus formation after PCI. Moreover, insufficient prevention of platelet aggregation sometimes induces restenosis after PCI. One of the signal transduction inhibitors, imatinib mesilate, blocks tyrosine kinase activity of platelet-derived growth factor receptor (PDGFR), and therefore it may block the development of neointima through growth inhibition of SMCs without the obstructive effect on EC-repair. We therefore studied the effects of imatinib on neointimal hyperplasia in a balloon injury model of rat carotid arteries. Rats were orally administered with imatinib for 14 days after balloon injury, and sacrificed to analyze the neointimal formation. Intimal hyperplasia was inhibited by imatinib in a dose-dependent manner. Therefore imatinib presumably obstructed the growth of SMCs via interception on growth-signaling of PDGFR. The administration of imatinib after coronary stenting or the use of an imatinib-eluting stent may further reduce the risk of restenosis in patients.
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  • Akira Ando, Masahito Hatori, Masami Hosaka, Yoshihiro Hagiwara, Atsush ...
    2008 Volume 215 Issue 4 Pages 307-312
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Focal fibrocartilaginous dysplasia (FFCD) is a rare and benign bone lesion that induces bowing deformity of the long bones in young children. Excessive production of fibrocartilage by abnormal differentiation in the metaphysis or by trauma during delivery or after birth is thought to cause growth disturbance. Radiologically, the lesion is characterized by a lucent defect with marginal sclerosis in the medial metaphysis of the long bone. However, there have been few reports about the initial radiological changes of FFCD before bowing started. We report a patient with FFCD in the left distal femur in whom the radiological changes were serially observed during the course of the disorder. A 2-week-old boy first visited our hospital because of left thigh pain. Plain radiographs did not show any abnormal findings at that time. At 10 weeks, a well-defined lucent defect with bony fragment inside was observed in the distal femoral medial cortex. At 1 year, this bony fragment gradually vanished but varus deformity progressed and reached approximately 40 degrees at the age of 2. After removal of the lesion, osteotomy and immobilzation was performed with Ilizarov external fixator comprising rings, rods and wires. Complete bone union was achieved 3 months after operation. It is noteworthy that we could observe the initial radiological changes of FFCD before varus deformity occurred. As far as we know, there have been no descriptions of the bony fragment inside a lucent defect of the lesion. Radiological features may vary in the early phase of FFCD.
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  • Seiji Shibuya, Hajime Hara, Yoshihiro Wakayama, Masahiko Inoue, Takahi ...
    2008 Volume 215 Issue 4 Pages 313-319
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Aquaporin (AQP) 4 is a water-specific channel protein and is abundant in central nervous tissues and skeletal muscles. Recently, the AQP4 molecule has been increasingly highlighted in its pathophysiological role of several neurological diseases, such as stroke, muscular dystrophy and neuromyelitis optica. We therefore measured the levels of AQP4 mRNA and glyceraldehyde-3 phosphate dehydrogenase mRNA (an internal control) in muscle and brain tissues of wild-type mice (C57BL10/ScSn) and age-matched dystrophin-deficient mdx mice (C57BL10/ScSn mdx) by real-time quantitative RT-PCR. The relative AQP4 mRNA level was highest in the spinal cord among the neuromuscular tissues examined in wild-type mice. Among the muscle tissues of wild-type mice, the relative AQP4 mRNA level was higher in extensor digitorum longus (EDL) muscles, and its descending order was EDL, quadriceps femoris, soleus and heart muscles. It is noteworthy that there was no difference in the relative AQP4 mRNA levels in the brain tissues between wild-type mice and age-matched mdx mice. In contrast, the AQP4 mRNA level in the quadriceps femoris muscle was significantly lower in mdx mice than in wild-type mice. The fact that the spinal cord contains the highest AQP4 mRNA may be related to the pathogenesis of neuromyelitis optica, in which AQP4 protein is the target antigen. In addition, the low expression level of AQP4 mRNA in the mdx mouse muscle suggests a functional link between AQP4 and dystrophin in the muscle tissue. We suggest that a similar pathomechanism may underlie the phenotypic consequences of the mdx mouse and Duchenne muscular dystrophy.
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  • Akira Ando, Yoshihiro Hagiwara, Eiichi Chimoto, Kouki Hatori, Yoshito ...
    2008 Volume 215 Issue 4 Pages 321-331
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Joint immobilization is a useful and common treatment modality in orthopedics. However, it also causes unfavorable outcome such as articular cartilage degeneration. Intra-articular injection of hyaluronan has been accepted as a treatment of osteoarthritis, but its effects on immobilized joint remain to be clarified. Hyaluronan is a polysaccharide, distributed ubiquitously in various tissues. In this study, we examined the effect of hyaluronan on the articular cartilage in immobilized joints. The unilateral knee joints of adult male rats were immobilized at 150° in flexion with an internal plate and screws for 1, 2, 4, 6, 8, 12, or 16 weeks (n = 84). Hyaluronan or saline (50 μl/each injection) was administered intra-articularly on the day of surgery and once a week. The articular cartilage from the medial midcondylar region of the knee was obtained, and divided into non-contact, contact and transitional areas (between the non-contact and the contact areas). In each area, a degree of degeneration was evaluated by histomorphometric grading, and measurements of thickness and number of chondrocytes. Histological grading scores in the hyaluronan group were smaller at 12 and 16 weeks compared with those in the saline group. The thickness of the articular cartilage increased in the transitional area in both groups. The number of chondrocytes in the contact and transitional areas gradually decreased, but their number in the hyaluronan group was greater at 12 and 16 weeks compared with that in the saline group. Hyaluronan showed chondroprotective effects on the articular cartilage in a rat immobilized-knee model.
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  • Taro Kitamura, Mitsutoshi Munakata, Kazuhiro Haginoya, Shigeru Tsuchiy ...
    2008 Volume 215 Issue 4 Pages 333-340
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    β-Phenylethylamine (β-PEA), an endogenous amine synthesized in the brain, serves as a neuromodulator and is involved in the pathophysiology of various neurological disorders such as depression, schizophrenia, and attention-deficit hyperactivity disorder. β-PEA fully exerts the physiological effects within the nanomolar concentration range via the trace amine receptors, but β-PEA also causes convulsions at much higher concentrations via an as yet unknown mechanism. To investigate the electrophysiological mechanism by which β-PEA induces convulsions, we examined the effect of β-PEA on ionic currents passing through the cell membrane of dissociated rat cerebral cortical neurons, using a patch-clamp technique. The external application of β-PEA suppressed ionic currents which continuously flowed when the membrane potential was held at −25 mV. The suppression was in a concentration-dependent manner and a half-maximal effective concentration was 540 μM. These currents suppressed by β-PEA consisted of two K+ currents: a time- and voltage-dependent K+ current (M-current) and a leakage K+ current. The suppression of the M-current reduces the efficacy of the current in limiting excessive neuronal firing, and the suppression of the leakage K+ current can cause membrane depolarization and thus promote neuronal excitation. Reducing both of these currents in concert may produce neuronal seizing activity, which could conceivably underlie the convulsions induced by high-dose β-PEA.
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  • Yukari Sugiyama, Haruo Mizuno, Yutaro Hayashi, Hiroki Imamine, Tetsuya ...
    2008 Volume 215 Issue 4 Pages 341-348
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Females with salt-wasting (SW) 21-hydroxylase deficiency (21OHD) may present with mild external genitalia virilization, despite complete or almost complete enzyme inactivation. We therefore analyzed genotype/phenotype correlation in 13 Japanese female patients with SW 21OHD. Criteria for classification into the SW phenotype included history of a salt-losing crisis with documented hyponatremia, hyperkalemia, and markedly elevated plasma renin activity. Urologists and pediatricians determined the Prader genital stage and classified the location of the vaginal entrance into the common urogenital sinus as low, moderate, or high. CYP21A2 gene, coding for 21-hydroxylase, was analyzed with Southern blotting and direct sequencing. Genotypes were categorized into four mutation groups, based on the degree of enzymatic activity (N, complete enzyme inactivation; groups A, < 2%, B, 3-7%, and C > 30%). Basal androgen levels were available from only six out of thirteen patients, so we could not relate androgen levels with the severity of external genitalia virilization. We compared the degree of external genitalia virilization with genotype. The severity of external genitalia virilization varied from Prader stage 1 to 4. One patient who presented with Prader 1 had a genotype consistent with Group B. In addition, discordance between Prader classification and the location of the vaginal entrance was noted; one patient classified as Prader 4 showed low vaginal entrance, while another patient classified as Prader 3 showed high vaginal entrance. The degree of the impairment of 21-hydroxylase activity does not correlate with the severity of virilization of the external genitalia in female patients with the SW type of 21OHD.
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  • Yuri Endo, Masaaki Suzuki, Yuichi Inoue, Mitsuo Sato, Kazuyoshi Namba, ...
    2008 Volume 215 Issue 4 Pages 349-354
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Sleep apnea syndrome (SAS) is basically divided into two types: obstructive and central SAS. Recently, the concept of complex SAS has been advocated. Complex SAS is defined as SAS that initially manifests as primarily obstructive SAS, but is characterized by the frequent central apneas after the removal of upper airway obstruction. To determine the prevalence and clinical significance of complex SAS among Japanese patients with SAS, 1,312 patients with SAS were enrolled in this study. Diagnosis of central SAS was made based on diagnostic polysomnography, and differentiation of obstructive SAS from complex SAS was made from polysomnographic findings for treatment with continuous positive airway pressure, which resolved upper airway obstruction. As a result, obstructive SAS was found in 1,232 of 1,312 patients with SAS (93.9%) and central SAS was found in 14 patients (1.1%). The overall prevalence of complex SAS was 5.0% (n = 66). The prevalence of complex SAS among 1,218 male and 94 female patients with SAS were 5.3% and 1.1%, respectively. Patients with complex SAS had significantly higher apnea/hypopnea indices than patients with either obstructive or central SAS, but were similar in both mean age and average body mass index to obstructive SAS patients. There were no significant between-group differences in numbers of patients with clinical complications including hypertension, cardiac diseases, or cerebrovascular diseases. In conclusion, the prevalence of complex SAS in Japanese SAS patients is 5.0%, which is lower than previously reported prevalence of complex SAS in the USA and Australia.
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  • Takahiro Mitsui, Kiyoshi Shimaoka, Shigeki Tsuzuku, Taeko Kajioka, His ...
    2008 Volume 215 Issue 4 Pages 355-361
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Obese people may succeed in reducing their weight temporarily, but most of them regain the lost weight within a few years. We, therefore, recommend moderate long-term changes in habit rather than a strict temporary program. The purpose of this study was to examine whether physical activity of 40 minutes, mainly walking, was effective in improving or preventing metabolic syndrome when combined with dieting. Participants, all of whom had a waist circumference ≥ 85 cm (men) or ≥ 90 cm (women), were assigned into one of two groups: the control group (10 men and 11 women, age: 64.2 ± 3.4 [SD] years) and the intervention group (10 men and 12 women, age: 62.4 ± 4.2 years). Participants (n = 22) enrolled in a 52-week program; their diets were assessed using a 3-day dietary record and daily steps were measured with a pedometer. No significant change was seen in their dietary records, but the mean number of daily steps increased from 5,806 to 8,000-9,000. In the intervention group, BMI, waist circumference, and systolic and diastolic blood pressures decreased significantly by week 12 (all p < 0.001) and remained low until week 52. In fact, no significant change was seen between weeks 12 and 52. The control group showed no significant changes in all variables. These results indicate that gentle exercise of about 40 minutes in combination with dieting is effective in preventing metabolic syndrome among a sedentary population, although its effect may be limited.
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  • Darko Grujicic, Olivera Miloševic-Djordjevic, Slobodan Arsenije ...
    2008 Volume 215 Issue 4 Pages 363-371
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    In prevention of preterm labor, betamimetics are used in gynecological practice mostly combined with antiarrhythmic verapamil because of their therapeutic cardiovascular side effects. The aim of this study was to investigate the influence of a betamimetic (ritodrine hydrochloride, fenoterol or hexoprenaline) and verapamil (administered to mothers) on the frequency of micronuclei (MN) in umbilical cord blood lymphocytes of neonates, using cytokinesis-block micronucleus test. The analyzed sample included 23 babies whose mothers received the therapy and 30 control babies whose mothers received no therapy. The average MN frequency was significantly higher in the neonates whose mothers received the therapy (8.13 ± 2.69 MN/1000 BN cells), in comparison with the baseline frequency in untreated controls (3.30 ± 2.63 MN/1000 BN cells), with probability p < 0.05. The highest MN frequency was found in neonates whose mothers received fenoterol and verapamil (2.8-fold i.e. 9.10 ± 3.00 MN/1000 BN cells), while ritodrine hydrochloride and hexoprenaline combined with verapamil induced 2.3-fold and 2.2-fold higher MN values than in controls (7.50 ± 3.33 MN/1000 BN cells and 7.29 ± 0.95 MN/1000 BN cells). Multiple linear regression analysis showed that MN frequency was affected only by the maternal therapeutic treatment, while the neonates' sex, maternal age, cigarette smoking, and therapeutic doses did not affect the MN frequency in umbilical lymphocytes of neonates. We conclude that the treatment of pregnant women with a betamimetic and verapamil significantly increases the MN frequency in umbilical cord blood lymphocytes of neonates, regardless to therapeutic doses.
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  • Orhan Ates, Mustafa Keles, Habip Bilen, Ahmet Kiziltunc, Ibrahim Kocer ...
    2008 Volume 215 Issue 4 Pages 373-376
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Retinal vein occlusion is an important cause of visual loss. Several ocular and systemic conditions have been reported for retinal vein occlusion. The pathogenesis of thrombus formation in the retinal vein, which results in retinal vein occlusion, is unclear. The aim of this study was to investigate the correlation between increased serum leptin levels and the occurrence of retinal vein occlusion (RVO). The study group consisted of 40 patients with RVO (58.1 ± 6 years old; 17 males and 23 females): 15 patients with central RVO, 23 with branch RVO, and 2 with hemispheric RVO. The patients who had any ocular or systemic pathology were not included in the study. The control group consisted of 40 healthy individuals of similar gender, age, date and type of health survey, and geographic region. The blood samples of the RVO patients (n = 40) and controls (n = 40) were obtained antecubitally. Leptin levels were measured by an enzyme-linked immunosorbent assay (ELISA) method, and Student's t-test was used to determine differences between the groups. The mean serum leptin levels were 12.5 ± 1.64 ng/ml in patients with RVO and 8.4 ± 1.22 ng/ml in the control subjects; namely, the mean serum leptin levels were significantly higher in the patients with RVO (p < 0.001). These results suggest that leptin may be involved in the pathogenesis of venous thrombosis in the retina probably through its effects on homeostasis of the vessel wall.
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  • Wen-Qiang Liao, Yan Pang, Chang-An Yu, Jian-Yan Wen, Yi-Guan Zhang, Xi ...
    2008 Volume 215 Issue 4 Pages 377-384
    Published: 2008
    Released: August 02, 2008
    JOURNALS FREE ACCESS
    Mitochondrial single nucleotide polymorphisms (mtSNPs) have been reported to associate with type-2 diabetes mellitus (T2DM), but mtSNPs appear to be considerably different among different populations and regions. To determine mtSNPs in Chinese Han patients with T2DM, the entire sequences of the mitochondrial genomes from 72 T2DM Chinese (59 ± 4 years) and 50 age-matched healthy subjects (controls) in Chongqing region of Western China were directly sequenced and mtSNPs were analyzed. We found that M8, M9, D, G, R and A haplogroups exist in Chinese Han population and the frequency of haplogroup M9 was significantly higher in patients with T2DM than in the controls (p = 0.0006, OR 0.06 [95% CI 0.008-0.476]). MtSNPs T3394C in NADH dehydrogenase subunit 1 (ND1), G4491A in ND2, T16189C and T16519C were found with significantly higher frequency in patients with T2DM than in the controls (T16189C, p = 0.0045; T16519C, p < 0.0001; T3394C, p = 0.0015; G4491A, p = 0.0015). In contrast, the frequency of C5178A in ND2 and A10398G in ND3 was higher in the controls than in patients with T2DM (C5178A, p = 0.014; A10398G, p = 0.0011). Our results indicate that mtSNPs T3394C, G4491A, T16189C and T16519C show susceptible tendency to T2DM and mtSNPs C5178A and A10398G seem to be genetic factors for against T2DM. These mtSNPs determined in our study is useful and could be used for early diagnosis and prevention of T2DM in Chinese Han population.
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