Tomoko Kadota

Chiba University, Chiba-shi, Chiba-ken, Japan

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Publications (39)66.73 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: At the Medical School of Chiba University, educational dissection tours have been conducted for intra- and extramural students in other programs, such as students of nursing. In the 2006 school year there were more than 1,500 students. As presented in a previous report, we tested an educational program in which our medical students teach other students parts of splanchnology, neurology, and myology to promote student understanding of human physiology through their own teaching. Since this system, termed the "teaching assistant system," was fairly laborious for many medical students, we attempted to improve it by decreasing the students' load and reducing the frequency of teaching from several times to once during the one-term dissection practice. We assessed the improved method with questionnaires for medical students who had studied at the school in 2006 and 2007 (n = 206) before and after teaching other students. The response rate for the questionnaires was 91.3% (n = 188). The results were as follows. (1) Most medical students (69.7%) realized that the task of teaching had stimulating effects on their own learning motivation. (2) According to most of their evaluations (80.4%), the duties of teaching involved in the previous assistant system were laborious. In contrast, the ratio of medical students who considered teaching to be laborious decreased by about half (55.3%) in the present improved system. (3) Most students (79.8%) were satisfied with the teaching assistant system. We concluded that the improved teaching assistant system was effective for the dissection practice.
    Kaibogaku Zasshi 07/2008; 83(2):45-50.
  • Tomoko Kadota, Ken Kadota
    Neuroscience Research 01/2007; 58. DOI:10.1016/j.neures.2007.06.1286 · 2.15 Impact Factor
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    ABSTRACT: Cadavers for gross anatomy laboratories are usually prepared by using embalming fluid which contains formaldehyde (FA) as a principal component. During the process of dissection, FA vapors are emitted from the cadavers, resulting in the exposure of medical students and their instructors to elevated levels of FA in the laboratory. The American Conference of Governmental Industrial Hygienists (ACGIH) has set a ceiling limit for FA at 0.3 ppm. In Japan, the Ministry of Health, Labour and Welfare has set an air quality guideline defining two limit values for environmental exposure to FA: 0.08 ppm as an average for general workplaces and 0.25 ppm for specific workplaces such as an FA factory. Although there are many reports on indoor FA concentrations in gross anatomy laboratories, only a few reports have described personal FA exposure levels. The purpose of the present study was to clarify personal exposure levels as well as indoor FA concentrations in our laboratory in order to investigate the relationship between them. The gross anatomy laboratory was evaluated in the 4th, 10th and 18th sessions of 20 laboratory sessions in total over a period of 10 weeks. Air samples were collected using a diffusive sampling device for organic carbonyl compounds. Area samples were taken in the center and four corners of the laboratory during the entire time of each session (4-6 hours). Personal samples were collected from instructors and students using a sampling device pinned on each person's lapel, and they were 1.1 to 6 hours in duration. Analysis was carried out using high performance liquid chromatography. Room averages of FA concentrations were 0.45, 0.38 and 0.68 ppm for the 4th, 10th and 18th sessions, respectively, ranging from 0.23 to 1.03 ppm. These levels were comparable to or relatively lower than the levels reported previously, but were still higher than the guideline limit for specific workplaces in Japan and the ACGIH ceiling limit. The indoor FA concentrations varied depending on the contents of laboratory sessions and seemed to increase when body cavity or deep structures were being dissected. In all sessions but the 4th, FA levels at the center of the room were higher than those in the corners. This might be related to the arrangement of air supply diffusers and return grills. However, it cannot be ruled out that FA levels in the corners were lowered by leakage of FA through the doors and windows. Average personal exposure levels were 0.80, 0.45 and 0.51 ppm for instructors and 1.02, 1.08 and 0.89 ppm for students for the 4th, 10th and 18th session, respectively. The exposure levels of students were significantly higher than the mean indoor FA concentrations in the 4th and 10th sessions, and the same tendency was also observed in the 18th session. The personal exposure level of instructors was also significantly higher than the indoor FA level in the 4th session, while they were almost the same in the 10th and 18th sessions. Differences in behavior during the sessions might reflect the differential personal exposure levels between students and instructors. The present study revealed that, if a person is close to the cadavers during the gross anatomy laboratory, his/her personal exposure level is possibly 2 to 3-fold higher than the mean indoor FA concentration. This should be considered in the risk assessment of FA in gross anatomy laboratories. If the risk of FA in gross anatomy laboratories is assessed based on the indoor FA levels, the possibility that personal exposure levels are 2 to 3-fold higher than the mean indoor FA level should be taken into account. Otherwise, the risk should be assessed based on the personal exposure levels. However, it is hard to measure everyone's exposure level. Therefore, further studies are necessary to develop a method of personal exposure assessment from the indoor FA concentration.
    Environmental Science and Pollution Research 04/2006; 13(2):120-4. DOI:10.1065/espr2005.06.265 · 2.76 Impact Factor
  • Journal of health science 01/2006; 52(5):642-647. DOI:10.1248/jhs.52.642 · 0.80 Impact Factor
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    ABSTRACT: Methamphetamine (MA) abuse induces deficits in cognitive performance that are related to dysfunction of the prefrontal cortex (PFC). The medial portion of the prefrontal cortex (mPFC) in rats that is crucial for cognitive function has been shown to undergo long-term potentiation (LTP) in the projections from the hippocampus. However, no study has been performed to evaluate the influence of MA on synaptic plasticity in the hippocampal-mPFC pathways. In the present experiments, we investigated the effects of repeated MA administration on hippocampal-mPFC LTP, together with MA-induced stereotyped behaviors. Repeated MA administration produced behavioral sensitization and LTP impairment in the hippocampal-mPFC pathways. The MA-induced impairment of hippocampal-mPFC LTP was prevented by the pretreatment of dopamine 1 (D1) but not dopamine 2 (D2) receptor antagonists, while D1 and D2 receptor antagonists attenuated the MA-induced stereotyped behaviors. These findings suggest that D1 receptors are crucial for the MA-induced deterioration of synaptic plasticity in the hippocampal-mPFC circuits. Impairment of LTP associated with D1 receptor dysfunction may underlie cognitive deficits in MA-dependent subjects.
    European Journal of Neuroscience 11/2005; 22(7):1713-9. DOI:10.1111/j.1460-9568.2005.04332.x · 3.67 Impact Factor
  • Kaibogaku Zasshi 10/2004; 79(3):95-100.
  • Tomoko Kadota, Ken Kadota
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    ABSTRACT: The present study examined whether the development in rats of behavioral sensitization to methamphetamine (MAP) is related to the development of neurotoxic morphological changes presumably induced in the medial prefrontal cortex (MFC). Male rats were intraperitonieally injected with MAP (5 mg/kg) once a day for 12 days (day 1-day 12), and then the drug was withdrawn for 7-42 days (WD7-WD42). The MAP- treatment caused hypersensitivity of a successive head-movement stereotypy, which reached a basic plateau level on day 4, and rose successively to a higher level by day 12. Morphological changes were histochemically and morphometrically examined in the MFC. In the strata covering layers II and III, the densities of tyrosine hydroxylase (TH)-immunoreactive axons decreased on a daily basis to 50% of the control on day 4 and then to 40% on days 6 and 12. The densities of dopamine-,beta-hydroxylase (DBH)-immunoreactive axons did not change during the injection period. A few TUNEL-positive cells were observed in a unit area (0.25 mm2) covering layers II-V on day 6 and they increased to 19 and 16 on day 12 and WD7, respectively. These observations demonstrate a role for the neurotoxic changes in the MFC in the processes of behavioral sensitization of a stereotypy to a low dose of MAP.
    Archives of Histology and Cytology 10/2004; 67(3):241-51. DOI:10.1679/aohc.67.241 · 0.60 Impact Factor
  • Kaibogaku Zasshi 04/2004; 79(1):35-9.
  • Toxicology Letters 09/2003; 144. DOI:10.1016/S0378-4274(03)90606-0 · 3.36 Impact Factor
  • Kaibogaku Zasshi 04/2003; 78(1):19-21.
  • Kaibogaku Zasshi 01/2003; 77(4):77-80.
  • Tomoko Kadota, Ken Kadota
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    ABSTRACT: Synaptic plasticity associated with long-term potentiation was studied electrophysiologically and ultrastructurally in the cat superior cervical ganglion in situ. The preganglionic nerve fiber was stimulated at 10 Hz for 50 s for conditioning and then at 1 Hz for 1-3 h to monitor changes in the postganglionic compound action potential (PGP). The present material has shown the long-term potentiation (LTP), around 120% of the control, which lasted for up to 3 h. Fifteen of 18 ganglia (83%) have shown LTP. Ultrastructural studies demonstrated the synaptic structural remodeling: (1) The preganglionic nerve terminals ordinarily made mainly asymmetrical type of shaft synapses directly with dendrites of the ganglion cells that lacked dendritic spines; (2) conditioning tetanus rapidly remodeled simple shaft synapses into perforated ones characterized by perforations in the postsynaptic density (PSD), some of which had synaptic spinules associated with the perforated PSDs, i.e. spinule-synapses; (3) a rapid increase in the number of both structures was detected immediately after the tetanus. Perforated synapses and the spinule-synapses increased from 5% and 0% in the control to 27 and 9% at 0 min, respectively. Spinule-synapses occurred about one-third of the perforated shaft synapses; (4) Increased numbers of restructured shaft synapses was maintained for 15 min in ganglia expressing LTP; (5) Remodeled synapses did not increase in ganglia that did not express LTP or ganglia that were activated at 0.5 or 1 Hz. It was suggested a rapid increase in the number of remodeled synapses associated with the onset of LTP and its durability at its earlier phases in the cat SCG.
    Neuroscience Research 07/2002; 43(2):135-46. DOI:10.1016/S0168-0102(02)00028-7 · 2.15 Impact Factor
  • Kaibogaku Zasshi 04/2002; 77(1):17-20.
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    ABSTRACT: Coated vesicles prepared from bovine brain cerebral cortex exhibited [3H]5-hydroxytryptamine (5-HT, serotonin) and [3H]spiperone binding activities. The binding activities were localized in the inner core vesicles. Binding reached an equilibrium level by 30-45 min at 30 degreesC, and was reversed by the addition of 100 microM 5-HT for [3H]5-HT binding or 10 microM ketanserin for [3H]spiperone binding. The saturation binding experiments indicated a single class of binding sites for [3H]5-HT and [3H]spiperone with apparent Kd values of 2.4 and 1.75 nM, respectively. The binding of [3H]5-HT was displaced by 5-HT and 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), but not by ketanserin. The binding of [3H]spiperone was displaced by spiperone and ketanserin but not by 5-HT or 8-OH-DPAT even at 1 mM. The coated vesicles were shown by immunoblotting assay to contain alpha-subunits of GTP-binding proteins, Galphas, Galphai2, Galphai3, Galphao and Galphaq/11. Forskolin-stimulated adenylate cyclase activity in the coated vesicles was inhibited to 80% of the control level by 5-HT or 8-OH-DPAT. These results suggested that 5-HT1A and 5-HT2A receptors are present in bovine brain coated vesicles and that the 5-HT1A receptors are coupled to adenylate cyclase activity via GTP binding proteins.
    Brain Research 07/1998; 794(2):291-8. DOI:10.1016/S0006-8993(98)00245-5 · 2.83 Impact Factor
  • Tomoko Kadota, Shuji Hasegawa, Ken Kadota
    Neuroscience Research 01/1998; 31. DOI:10.1016/S0168-0102(98)82467-X · 2.15 Impact Factor
  • Neuroscience Research 01/1997; 28. DOI:10.1016/S0168-0102(97)90475-2 · 2.15 Impact Factor
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    ABSTRACT: The four kinds of oligopeptides specific in amino acid sequence to a rat dopamine transporter (DAT), peptide-1-peptide-4, were chemically synthethized. An attempt to produce antipeptide antibodies against these oligopeptides was made with an in vitro immunization method. Two monoclonal antibodies, MAbs H-1a and H-1b, were produced against one of the oligopeptides, peptide-1. Western blot analysis confirmed that the two antibodies recognized an approximately 85,000 Da protein in a synaptosomal fraction prepared from the rat striatum but none in the fraction from the cerebellum. The specificity of the antibody to DAT was also confirmed by an antibody absorption test using two synthetic oligopeptides, one of which is specific only to DAT. These results have confirmed the specificity of the present antibody to DAT. The expression and subcellular localization of DAT were immunohistochemically examined with MAbs H-1a and H-1b in PC12 cells treated with nerve growth factor (NGF). The antibody labeled the surface of PC12 cells. When the cells were treated with NGF, the expression of DAT was significantly emphasized, first in the area mainly including the Golgi apparatus and rough endoplasmic reticulum and then on the surface of growth cones from the beginning of neurite outgrowth. DAT was detected by Western blot analysis in a microsomal fraction prepared from PC12 cells. The activity of DAT in the PC12 cells was pharmacologically confirmed by the uptake of [3H]-dopamine and blockade by uptake inhibitors. The NGF treatment doubled the dopamine uptake activity. GBR12909, a specific inhibitor of DAT, blocked the [3H]-dopamine at a concentration of 10(-7) M. The expression of DAT and norepinephrine transporter (NET) mRNA in the PC12 cells was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). DAT mRNA significantly increased in the NGF-treated cells after 7 days of incubation, whereas NET mRNA markedly decreased.
    Journal of Histochemistry and Cytochemistry 10/1996; 44(9):989-96. DOI:10.1177/44.9.8773564 · 2.40 Impact Factor
  • Tomoko KADOTA, Muneaki MIZOTE, Ken KADOTA
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    ABSTRACT: A synaptic spinule formed on the postsynaptic membrane in the cat superior cervical ganglion (SCG) in vivo was electron microscopically studied, When the preganglionic nerve fiber was tetanically stimulated at 10 Hz for more than 10 seconds, a post-tetanic potentiation (PTP) was electrophysiologically detected and maintained up to 30 min. Concurrently with PTP, a small process, termed as synaptic spinule, was generated as a small projection standing out from the postsynaptic dendritic membrane with a straightly extended contour. The spinule produced a break at about a middle point of the postsynaptic density (PSD) and divided it into two parts forming a perforated synapse. Then, the spinule increased in size, invaginated into the cytoplasm of the nerve terminal, and subdivided the presynaptic terminal bag into two compartments. Each of the compartments retained a morphology of an active synaptic site with a cluster of synaptic vesicles associated with a presynaptic active zone standing opposite to the one part of the subdivided PSD. The longer the tetanic stimulation in period, the more the synapses with the spinule increased in number. In addition to this, a few spinules (multiple type of spinule) were often formed after the stimulation of 1 min and more than two compartments were generated in a single nerve ending. The present observations have suggested that the synaptic spinule is a morphological representation of the ''synaptic plasticity'' which is electrophysiologically displayed as the PTP in cat SCG in vivo.
    Proceedings of the Japan Academy Ser B Physical and Biological Sciences 03/1996; 72(3):48-51. DOI:10.2183/pjab.72.48 · 2.56 Impact Factor
  • Neuroscience Research 01/1996; 25. DOI:10.1016/0168-0102(96)89014-6 · 2.15 Impact Factor
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    ABSTRACT: Two kinds of oligopeptides, based on the amino acid sequences of No. 217-232 and 374-387 of a rat dopamine transporter, were designed and chemically synthesized. Five clones of the monoclonal antibodies against these peptides were produced with the in vitro immunization method. Two of them have recognized a protein of M(r) approximately 85,000 in a synaptosomal fraction of the rat striatum. It is probable that the protein M(r) approximately 85,000 corresponds to a dopamine transporter in the nerve terminal of the dopamine neurons in the striatum. The expression of dopamine transporter was immunohistochemically examined with these antibodies in PC12h cells. The immunoreactivity was detected on the surface membrane of the cells.
    Kaibogaku Zasshi 07/1995; 70(3):248-51.

Publication Stats

229 Citations
66.73 Total Impact Points

Institutions

  • 1985–2008
    • Chiba University
      • Graduate School of Medicine
      Chiba-shi, Chiba-ken, Japan
  • 2003
    • Catholic University of Louvain
      Лувен-ла-Нев, Walloon, Belgium
  • 1998
    • Chiba University Hospital
      Tiba, Chiba, Japan
  • 1996
    • Tokyo Metropolitan Institute of Medical Science
      Edo, Tōkyō, Japan
    • Teikyo University
      Edo, Tōkyō, Japan
  • 1974
    • The Royal Institution of Great Britain
      Londinium, England, United Kingdom