• Title/Summary/Keyword: repeated dose

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Evaluation of the testicular toxicity caused by 2-bromopropane in rats (랫드에 있어서 2-bromopropane에 의해 유발된 정소독성의 평가)

  • Kim, Jong-choon;Lee, Hyun-sook;Yun, Hyo-in;Chung, Moon-koo
    • Korean Journal of Veterinary Research
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    • v.40 no.2
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    • pp.361-371
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    • 2000
  • It has been recently reported that 2-bromopropane (2-BP) induces male reproductive toxicity in both human and experimental animals. However, delayed effects of 2-BP on male reproductive system have not been investigated in detail. The present study was conducted to investigate the testicular toxicity of 2-BP and to determine the recovery of normal spermatogenesis in Sprague-Dawley rats. Male rats aged 5 weeks were administered 1,000mg/kg 2-BP by gavage daily for 4 weeks and sacrificed sequentially at 1, 2, 3, 4 and 12 weeks after initiation of 2-BP treatment. Testicular toxicity was evaluated qualitatively by histopathological examinations and quantitatively by reproductive organ weights, spermatid head count, and repopulation index. In the 2-BP treated rats, the body weights was significantly suppressed and the weights of testes and epididymides were also decreased in a time-dependent manner. On histopathological examination, spermatogonia in stages I-VI and preleptotene and leptotene spermatocytes in stages VII-IX were strongly depleted at 1 week of dosing. Spermatogonia were depleted extensively in all spermatogenic stages at 2 weeks. Continuing with the evolution of spermatogenic cycle, zygotene spermatocytes, pachytene spermatocytes, and round spermatids were sequentially depleted at 2, 3, and 4 weeks of dosing due to the depletion of their precursor cells. Vacuolization of Sertoli cells and spermatid retention were also observed at all time points, suggesting that 2-BP induced Sertoli cell dysfunction. At 12 weeks, after 8 weeks recovery, most of the tubules appeared severely atrophic and were lined by Sertoli cells only. Leydig cell hyperplasia in the interstitial tissue was also found. In addition, dramatic reductions in the number of spermatid heads and repopulation index were observed, indicating that 2-BP-induced testicular injury is irreversible. These results indicate that 4 weeks repeated-dose of 1,000mg/kg 2-BP results in a progressive germ cell loss due to the depletion of spermatogonia followed by long-term testicular atrophy in SD rats.

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The Effect of Sahyangsohapwon on Heart Rate Variability of Healthy Subjects (사향소합원(麝香蘇合元)이 정상인의 심박변이도에 미치는 영향)

  • Kim, Chang-Hyun;Hwang, Jae-Woong;Min, In-Kyu;Kim, Mi-Young;Byeon, Hyung-Sik;Na, Byong-Jo;Park, Sung-Wook;Park, Jung-Mi;Ko, Chang-Nam;Bae, Hyung-Sup;Jung, Woo-Sang;Moon, Sang-Kwan;Cho, Ki-Ho;Kim, Young-Suk
    • The Journal of Korean Medicine
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    • v.30 no.1
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    • pp.120-127
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    • 2009
  • Objectives: Sahyangsohapwon (SS) is a herbal medication that has been widely used with circulatory and neural diseases. This study was conducted to assess the effect of SS on the autonomic nervous system by using heart rate variability measurement. Methods: The eligible subjects were enrolled from the healthy male group of ages 20 to 35 years. They were divided into two groups, the SS group (n=26) and the control (n=24). We monitored the ECG of subjects from the time period 14:00 to 18:00. In the SS group, subjects were administered with a dose of SS at the time 15:00, whereas the control group had none. For each hour HRV measurement was monitored every 15 minutes for 512 seconds from the time period 14:00 to 18:00. The mean value, which was calculated using the 4 values during each hour (i.e. 14:00, 14:15, 14:30, 14:45), was used as the representative value for each individual hour. For the measurement values, RR-interval and SDNN (standard deviation of the NN intervals) were used as time domain analysis, and HF (high frequency), LF (low frequency), and LF/HF ratio were used as frequency domain analysis. Results: The LF value showed an increase after one hour of SS administration and showed gradual diminution for each and every hour. The repeated measures of ANOVA for the comparison of the LF value between the SS group and the control group showed significant differences. While, RR interval, SDNN, HF, and LF/HF ratio values showed no significant differences between the two groups. Conclusions: We suggest that the SS might be useful for stabilizing autonomic nervous system by inhibiting sympathetic nerve activation in healthy people.

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Principle and Recent Advances of Neuroactivation Study (신경 활성화 연구의 원리와 최근 동향)

  • Kang, Eun-Joo
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.2
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    • pp.172-180
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    • 2007
  • Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

Combined Modality Treatment in Nasopharyngeal Carcinoma (비인강암의 병합요법)

  • Yun, Sang-Mo;Kim, Jae-Cheol;Park, In-Kyu
    • Radiation Oncology Journal
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    • v.19 no.2
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    • pp.100-106
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    • 2001
  • Purpose : We performed a retrospective analysis to compare short term results of induction chemotherapy-radiotherapy versus concurrent chemo-radiotherapy in patients with locally advanced nasopharyngeal carcinoma. Materials and Methods : From Oct. 1989 to May 1998, 62 patients with locally advanced nasopharyngeal carcinoma were treated with induction chemotherapy followed by radiotherapy (induction group) or concurrent chemo-radiotherapy (concurrent group). Induction chemotherapy was done for 50 patients, and concurrent chemotherapy for 12 patients. Age, sex, performance status, and pathologic types were evenly distributed between two groups. Stage distribution showed $32\%$ with IIB, $32\%$ with III, and $38\%$ with IV in induction group, and $50\%,\;33.3\%,\;and\;16.7\%$ in concurrent group, respectively. Chemotherapy regimen was CF (cisplatin and 5-FU) in both groups, and drug delivery method also same. Cisplatin $100\;mg/m^2$ was intravenously infused on day 1, and 5-FU $1,000\;mg/m^2$ on day $2\~6$. This was repeated at 3 weeks interval. At the end of radiotherapy, total cycles of chemotherapy were $1\~3$ (median 2) in both groups. Conventionally fractionated radiotherapy with daily fraction size $1.8\~2.0\;Gy$ and 5 fractions/week was done. Total dose was $69.4\~86\;Gy$(median 73.4 Gy) for induction group, and $69.4\~75.4\;Gy$ (median 70.8 Gy) for concurrent group. Follow-up time was $9\~116$ months (median 40.5 months) for induction group, $14\~29$ months (median 21 months) for concurrent group, respectively. Results : Overall 2 year survival rate (2YSR) for all patients was $78.7\%$. According to treatment modality, 2YSR were $77\%$ for induction group, $87\%$ for concurrent group (p>0.05). 2 year disease-free survival rate were $56\%$ and $81\%\;(p>0.05)$, respectively. Complete response to treatment were $75.5\%$ for induction group and $91.7\%$ for concurrent group, but there was no statistical difference. The incidence of grade $3\~4$ hematologic toxicity during radiotherapy was not differ between two groups, but grade 2 leukopenia was more frequent in concurrent group $(18\%\;vs\;66.7\%)$Grade $3\~4$ mucositis was more frequent in concurrent group $(4.0\%\;vs\;33.3\%)$. Overall incidence of grade $3\~4$ acute toxicity during radiotherapy was more frequent in concurrent group $(6.0\%\;vs\;41.7\%,\;p=0.005)$. Conclusion : Concurrent chemo-radiotherapy showed a trend of improvement in short-term survival and in treatment response when compared with induction chemotherapy-radiotherapy in locally advanced nasopharyngeal carcinoma. More controlled randomized trial are needed.

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