The Tohoku Journal of Experimental Medicine
Online ISSN : 1349-3329
Print ISSN : 0040-8727
ISSN-L : 0040-8727
Volume 211, Issue 2
February
Displaying 1-12 of 12 articles from this issue
Invited Review
  • Kesara Na-Bangchang, Kanungnit Congpuong
    2007 Volume 211 Issue 2 Pages 99-113
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    Malaria is the world's most important parasitic infection ranking among the major health and developmental challenges. Despite years of continual efforts, malaria is still one of the major causes of morbidity and mortality affecting third-world countries and still a threat to over 2 billion people, representing approximately 40% of the world's population in about 100 countries (Rollback Malaria 2005). During the “eradication era”, half a century ago, malaria was eliminated or effectively suppressed in many parts of the world, particularly subtropical regions. The disease is now on the rise again since it is appearing in areas where it had disappeared. The disaster can largely be attributed to antimalarial drug resistance in most malaria endemic countries. Geographical distribution of the disease is worldwide, being found in tropical areas, throughout sub-Saharan Africa and to a lesser extent in South Africa, Southeast Asia, the Pacific Islands, India and Central and South America. Best estimates currently describe the annual global burden of malaria as 300-500 million cases and 1-2 million deaths. Over 90% of the disease burden is in sub-Saharan Africa. The malaria burden differs according to age and gender; almost all deaths occur in African children under 5 years of age (Snow et al. 2001). Pregnant women in Africa (especially primigravidae) are at high risk, and are the major adult risk group in the continent. An increasing number of imported cases of malaria have been reported particularly as a result of increasing worldwide travel to regions where there is ongoing risk of malaria transmission. Nowadays, cases of malaria acquired by international travelers from developed countries probably number 25,000 cases per year, with 10,000 of them reported annually and approximately 150 deaths per year.
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Regular Contributions
  • Çimen Olguner, Ugur Koca, Mert Akan, Ayse Karci, Zahide Elar
    2007 Volume 211 Issue 2 Pages 115-120
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    Apneic oxygenation is an apnea testing method in the diagnosis of brain death. In this method, oxygen (O2) is delivered into the trachea via an O2 catheter (O2C). However, barotrauma may develop during O2 insufflation into the trachea. Oxygen catheter diameters, O2 catheter tip position in the trachea, and O2 flow rate have been proposed as causes of barotrauma. This study was designed to highlight the airway pressure changes during apneic oxygenation in a model consisting of an anesthesia bag, which was connected to a pressure transducer and to an endotracheal tube (ETT). The pressure of the system was monitored while delivering O2 continuously to the system through O2C of different diameters, which were placed in the ETT. Tested variables were ETT/O2C ratio, O2C tip position in ETT (proximal 1/3 of the ETT, mid point of the ETT, and distal 1/3 of the ETT) and O2 flow rate (6, 8, and 10 L min−1). The increase in the airway pressure significantly correlated with O2C tip position in ETT (p = 0.017). ETT/O2C ratio smaller than 1.75 caused significantly high airway pressures (p < 0.05). The pressure was significantly higher at the flow rate of 10 L min−1 O2 compared with the flow rate of 6 L min−1 O2 (p < 0.01). Thus, ETT/O2C ratio, O2C tip position in ETT and O2 flow rate are the important factors that determine the airway pressure in the trachea during O2 insufflation. In conclusion, overlooked mechanical factors dangerously increase airway pressure during apnea testing.
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  • Oral Nevruz, Mehmet Yokusoglu, Mehmet Uzun, Sait Demirkol, Ferit Avcu, ...
    2007 Volume 211 Issue 2 Pages 121-126
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    Acute leukemia is one of the leading malignancies worldwide. Although neuropathy was reported as one of the complications of leukemia, there is a little data about the autonomic involvement. This study was designed to investigate the cardiac autonomic disturbances in acute leukemias by using time-domain indices of heart rate variability (HRV). Newly diagnosed 36 patients with acute leukemia (14 acute lymphoblastic leukemia and 22 acute myeloblastic leukemia) and gender- and age-matched 32 healthy subjects as controls were enrolled in this study. The diagnosis of leukemia was established by whole blood count, peripheral smears and bone marrow aspirations. In order to rule out the effect of any medication on HRV, the patients were selected from those who had not received any antineoplastic agent yet. For assessing the cardiac autonomic functions, HRV obtained from 24-hr Holter monitor recordings was used. The age, gender and serum ferritin levels were similar, while hemoglobin levels were lower in the leukemia group. The comparison of the leukemia group and control group revealed that HRV decreased in patients with acute leukemia, which reflects sympathetic dominance in acute leukemia. This is the first study that shows altered cardiac autonomic functions in patients with acute leukemias who are not on any therapeutical intervention. The altered cardiac autonomic functions may be a sign of paraneoplastic neuropathy in patients with acute leukemia.
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  • Hiroaki Yoshino, Hiroyuki Kayaba, Tatsuzo Hebiguchi, Mayako Morii, Tak ...
    2007 Volume 211 Issue 2 Pages 127-132
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    The physiopathology of idiopathic chronic constipation is complex and yet to be investigated. In the manometric studies of the patients with severe chronic constipation, we noticed that some patients with megacolon show very slow periodical (< 2/min) pressure change in the anal canal, namely ultra slow waves (USWs). USWs are considered to represent the hyperactivity of the internal anal sphincter; however, USW-related clinical presentations have yet to be investigated. We retrospectively re-evaluated the patient records and manometric studies of 85 cases, 51 subjects without defecatory problems and 34 patients with constipation, to elucidate USW-related clinical presentations. USWs were seen in 10 patients, including eight patients with chronic constipation and two subjects without defecatory problems. Out of the eight patients with constipation, one had no organic change in the anorectum, three had hemorrhoids and four exhibited megacolon. Manometric and pathological studies proved that none of the four patients with magacolon was suffering from Hirschsprung's disease. Among the 51 subjects without defecatory problems, only two had USWs. Anal pressure in the USW-positive group (106.0 ± 37.0 cmH2O) was significantly higher than that in the group without defecatory problems (56.0 ± 27.0 cmH2O) or constipated patients without USWs (55.0 ± 26.0 cmH2O). Megacolon and high anal pressure, as well as chronic constipation and hemorrhoids, were the clinical presentations related to USWs. This is the first report to show the clinical relevance of USWs to megacolon. USWs should be recognized as an important manometric finding indicating a possible new clinical entity in chronic constipation.
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  • Ayako Hattori, Junichiro Hayano, Shinji Fujimoto, Naoki Ando, Kumiko M ...
    2007 Volume 211 Issue 2 Pages 133-139
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    West syndrome (WS) is a generalized epileptic syndrome of infancy and early childhood with various etiologies, and consists of a triad of infantile spasm, arrest or regress of psychomotor development and specific electroencephalogram (EEG) pattern of hypsarrhythmia. WS had been believed to be refractory, but recent evidence supports effectiveness of adrenocorticotropic hormone (ACTH) treatment. The ACTH treatment, however, has a problem that it is often accompanied by adverse autonomic symptoms. We therefore examined heart rate variability (HRV) for assessing cardiac autonomic functions in WS and prospectively observed the changes during ACTH treatment. We studied 15 patients with WS and 9 age-matched controls during sleep (EEG stage 2). Compared with controls, the patients with WS were greater in the low-frequency component (LF) of HRV, an index reflecting sympatho-vagal interaction (p = 0.02), but were comparable for high-frequency component (HF) and LF-to-HF ratio (LF/HF), indices reflecting cardiac vagal activity and sympathetic predominance, respectively. During ACTH treatment, heart rate decreased (p < 0.01), LF and HF increased (p < 0.01), and LF/HF did not differ significantly. These results indicate that WS might be accompanied by autonomic changes and that ACTH treatment enhances parasympathetic function and causes bradycardia.
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  • Hiroshi Maejima, Azusa Murase, Hitoshi Sunahori, Yuji Kanetada, Takuya ...
    2007 Volume 211 Issue 2 Pages 141-149
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    Reflecting the rapidly aging population, community-based interventions in the form of physical exercise have been introduced to promote the health of elderly persons. Many investigation studies have focused on muscle strength in the lower leg as a potent indicator of the effect of physical exercises. The objective of this study was to assess the effect of long-term daily exercises on neural command in lower leg muscle activations. Twenty-six community-based elderly persons (13 men and 13 women; 69.8 ± 0.5 years old) participated in this study. Daily exercise was comprised of walking for more than 30 min, stretching, muscle strengthening and balance exercise, and was continued for three months. Muscle strength and surface electromyography of the tibia anterior, rectus femoris, and biceps femoris were measured in maximum isometric voluntary contraction both before and after the intervention. The mean frequency of the firing of motor units was calculated based on fast Fourier transformation of the electromyography. As the results of the intervention, muscle strength increased significantly only in biceps femoris, whereas the mean frequency of motor units decreased significantly in every muscle, indicating that motor unit firing in lower frequency efficiently induces the same or greater strength compared with before the intervention. Thus, synchronization of motor units compensates for the lower frequency of motor unit firing to maintain muscular strength. In conclusion, long-term physical exercises in the elderly can modulate the neural adjustment of lower leg muscles to promote efficient output of muscle strength.
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  • Mariko Nishikitani, Yukiko Yasuoka, Hideaki Kawada, Katsumasa Kawahara
    2007 Volume 211 Issue 2 Pages 151-160
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    The enteric nervous system regulates epithelial ion and fluid secretion. Our previous study has shown that the low (0.2-1 mM) concentrations of Ba2+, a K+ channel inhibitor, evoke Ca2+-dependent oscillatory Cl− secretion via activation of submucosal cholinergic neurons in guinea pig distal colon. However, it is still unclear which types of Ca2+ channels are involved in the oscillation at the neuroepithelial junction. We investigated the inhibitory effects of organic and inorganic Ca2+ channel antagonists on the short circuit current (Isc) of colonic epithelia (mucosa-submucosa sheets) mounted in Ussing chambers. The amplitude (412 ± 37 μA cm−2) and frequency (2.6 ± 0.1 cycles min−1) of the Ba2+-induced Isc in normal (1.8 mM) Ca2+ solution (n = 26) significantly decreased by 37.6% and 38.5%, respectively, in the low (0.1 mM) Ca2+ solution (n = 14). The Isc amplitude was reversibly inhibited by either verapamil (an L-type Ca2+ channel antagonist) or divalent cations (Cd2+, Mn2+, Ni2+) in a concentration-dependent manner. The concentration of verapamil for half-maximum inhibition (IC50) was 4 and 2 μM in normal and low Ca2+ solution, respectively. The relative blocking potencies of metal ions were Cd2+ > Mn2+, Ni2+ in normal Ca2+ solution. In contrast, the frequency of Isc was unchanged over the range of concentrations of the Ca2+ channel antagonists used. Our results show that the oscillatory Isc evoked by Ba2+ involves L-type voltage-gated Ca2+ channels. We conclude that L-type Ca2+ channels play a key role in the oscillation at the neuroepithelial junctions of guinea pig colon.
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  • Xiao-Qi Xie, Yotaro Shinozawa, Junichi Sasaki, Kiyotsugu Takuma, Satos ...
    2007 Volume 211 Issue 2 Pages 161-169
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    Oxygen-derived free radicals play important roles in pathophysiological processes in critically ill patients, but the data characterizing relationships between radicals and neuroendocrine system response are sparse. To search the cue to reduce the oxidative cellular damage from the point of view of neuroendocrine system response, we studied the indicators of neuroendocrine and inflammatory responses excreted in urine in 14 burn patients (42.3 ± 31.4 years old, and 32.3 ± 27.6% burn of total body surface area [%TBSA]) during the first seven days post burn. The daily mean amounts of urinary excretion of 8-hydroxy-2'-deoxy-guanosine (8-OHdG), a marker of oxidative cellular damage, were above the upper limit of the standard value during the studied period. The total amount of urinary excretion of 8-OHdG in the first day post burn correlated with burn severity indices: %TBSA (r = 0.63, p = 0.021) and burn index (r = 0.70, p = 0.008). The daily urinary excretion of 8-OHdG correlated with the daily urinary excretion of norepinephrine and nitrite plus nitrate (NOx) during the studied period except day 2 post burn, and correlated with the daily urinary excretion of 17-hydroxycorticosteriod (17-OHCS) in days 2, 3, and 7 post burn. These data suggest that oxidative cellular damage correlates with burn severity and neuroendocrine system response modulates inflammation and oxidative cellular damage. Modulation of neuroendocrine system response and inflammation in the treatment in the early phase of burn may be useful to reduce the oxidative cellular damage and to prevent multiple organ failures in patients with extensive burn.
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  • Takanori Fujimoto, Yasuo Tsuchiya, Norio Shibuya, Mayumi Taiyoji, Tosh ...
    2007 Volume 211 Issue 2 Pages 171-180
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    While normally monitoring the Shinano River water quality, including examinations for mutagenicity, the Niigata Chuetsu Earthquake suddenly occurred on October 23, 2004. However, the influence of this earthquake on the mutagenicity of river water has not yet been well studied. To clarify the regional and seasonal changes in mutagenicity of the Shinano River water, blue rayon was suspended for 24 hrs at 4 sampling sites, once a month from September 2004 through August 2005. Mutagenicity was evaluated by the Ames test using Salmonella typhimurium TA98 (TA98) and TA100 with or without metabolic activation by S9 mixture. To detect and identify poly-aromatic hydrocarbons that may be responsible for the mutagenicity of the river water, we analyzed benzo[a]pyrene, benzophenone, 4-nitrotoluene, or other compounds using gas chromatography-mass spectrometry and total ion chromatogram spectra. Positive manifestations of TA98 with S9 mixture were observed at the 4 sampling sites throughout the 12-month test, showing a tendency to be higher at the downstream site and in winter. However, the highest mutagenicity was observed in the sample collected at the most upstream sampling site in December 2004, and fluoranthene or pyrene consisting mainly in coal tar was detected only in the samples collected in December 2004. Although benzo[a]pyrene, benzophenone, and 4-nitrotoluene were below the detection limits, non-mutagens such as aliphatic hydrocarbons or esters were frequently detected. Our findings indicate that either fluoranthene or pyrene was mainly responsible for the mutagenicity of the river water in December 2004, suggesting the possibility of oil contamination caused by the Niigata Chuetsu Earthquake.
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  • Levent Altinel, Z. Kadir Saritas, Kamil Cagri Kose, Kamuran Pamuk, Yus ...
    2007 Volume 211 Issue 2 Pages 181-186
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    Avocado and soya unsaponifiables (ASU) are plant extracts used as a slow-acting antiarthritic agent. ASU stimulate the synthesis of matrix components by chondrocytes, probably by increasing the production of transforming growth factor-β (TGF-β). TGF-β is expressed by chondrocytes and osteoblasts and is present in cartilage matrix. This study investigates the effect of ASU treatment on the levels of two isoforms of TGFβ, TGF-β1 and TGF-β2, in the knee joint fluid using a canine model. Twenty-four outbred dogs were divided into three groups. The control animals were given a normal diet, while the treated animals were given 300 mg ASU every three days or every day. Joint fluid samples were obtained prior to treatment, and at the end of every month (up to three months). TGF-β1 and TGF-β2 levels were measured using a quantitative sandwich enzyme immunoassay technique. ASU treatment caused an increase in TGF-β1 and TGF-β2 levels in the joint fluid when compared to controls. The different doses did not cause a significant difference in joint fluid TGF levels. TGF-β1 levels in the treated animals reached maximum values at the end of the second month and then decreased after the third month, while TGF-β2 levels showed a marginal increase during the first two months, followed by a marked increase at the end of the third month. In conclusion, ASU increased both TGF-β1 and TGF-β2 levels in knee joint fluid.
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  • Tuncay Nas, Süreyya Barun, Gökce Sevim Öztürk, Ism ...
    2007 Volume 211 Issue 2 Pages 187-193
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    The women who smoke have lower fertility rates which might be due to harmful effects of nicotine on tubal function and menstrual cycle. Although the uterine contractility of the non-pregnant uterus plays an important role in the human reproduction process, the influence of nicotine on the contractile responses in uterus is not known. Nicotine increases the release of neurotransmitters following nerve stimulation both in the central and peripheral nervous system through acting on nicotinic acetylcholine receptors (nAchRs). The aim of this study was to examine whether the electrical field stimulation (EFS)-evoked contraction is altered in rabbit myometrium strips in the presence of nicotine to evaluate the changes in contractility. EFS-evoked contractile responses were recorded from myometrium strips obtained from non-pregnant rabbits in the absence and presence of nicotine. Nicotine led to the increase in the amplitudes of the EFS-evoked contractile responses in a dose-dependent manner. Therefore, the effects of hexamethonium, cadmium, indomethacin, atropine, and Nω-Nitro-L-arginine methyl ester hydrochloride were tested on the EFS-evoked contractions in the absence or presence of nicotine to clarify the mechanisms of nicotine-induced potentiation in EFS-evoked contractile responses. Indomethacin, a non-selective cyclooxygenase inhibitor, and hexamethonium, a ganglionic blocker, inhibited nicotine-induced increase in EFS-evoked responses, whereas other chemicals produced no effect. These results suggest that nicotine-induced potentiation may be mediated by nAchRs and prostaglandins. In conclusion, failure of quiescence in the uterus due to increased contractility by nicotine might be one of the factors contributing to infertility in female smokers.
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Case Report
  • Chikashi Nakanishi, Naoki Kawagishi, Satoshi Sekiguchi, Yorihiro Akama ...
    2007 Volume 211 Issue 2 Pages 195-200
    Published: 2007
    Released on J-STAGE: February 08, 2007
    JOURNAL FREE ACCESS
    The majority of acute cellular rejection occurs in the first few months after liver transplantation. It has been, however, reported that some recipients experience late acute rejection, which occurs more than 3 months after transplantation. We herein report a case of late acute rejection that occurred nearly 10 years after liver transplantation. The patient is a 27-year-old male who underwent a living donor liver transplantation when he was 17 years old. At 9 years 6 months after transplantation, the patient presented with the elevated serum levels of liver enzymes and total bilirubin. A liver biopsy showed acute cellular rejection. Steroid bolus therapy was not effective, but we successfully used deoxyspergualin as a rescue therapy. Late acute cellular rejection that occurs nearly 10 years after transplantation has so far been rarely reported. It is generally believed that late acute rejection may be more resistant to treatment and be associated with a higher rate of graft loss, as well being associated with the development of chronic ductopenic rejection. In this report, we have shown that deoxyspergualin is safe and effective for treatment of steroid-resistant late acute rejection, preventing from graft loss of chronic rejection.
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