• The Korean Journal of Pharmacology
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• v.2 no.1 s.2
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• pp.71-82
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• 1966

The inhibitory effect of 5-hydroxytryptamine (5-HT) on the isolated intestinal strips of the tortoise (Amyda japonica), rat, rabbit and guinea pig was investigated. 1) The strips from the middle or lower part of the tortoise intestine responded with relaxation to 5-HT $(10^{-9}{\sim}10^{-5}g/ml)$, and the magnitude of the relaxation was proportional to the dose of 5-HT. The rectal part of the tortoise intestine, in contrast, showed contraction, the magnitude of which also was proportional to the dose of 5-HT. 2) Various blocking agents such as methysergide, morphine, tetracaine, nethalide, bretylium, hexamethonium, mecamylamine and chlorisondamine, showed no selective blocking activity on the relaxant effect of 5-HT on the tortoise intestine. The inhibitory effect of isoproterenol on the tortoise intestine, however, was selectively blocked by nethalide, and the stimulatory effect of 5-HT on the rectal part of the tortoise was blocked by methysergide. 3) In the presence of 5-HT, the stimulatory effect of DMPP on the tortoise intestine was remarkably attenuated, whereas that of acetylcholine and $BaCl_2$ was little affected. In the presence of isoproterenol, the stimulatory effect of acetylcholine and $BaCl_2$ were affected, but that of DMPP was little affected. 4) Large dose of 5-HT($10^{-4}$g/ml) produced inhibitory effect on the strips from the distal part of the isolated colon of the rat, rabbit and guinea pig, when the strips had been exposed to 5-HT($10^{-4}$g/ml), methysergide or phen`oxybenzamine. 5) Bretylium, as well as nethalide, abolished or remarkably reduced, in a few cases of the experiments, the inhibitory effect of the large dose of 5-HT on the distal part of the colon, whereas morphine did not affect it. 6) The ileal strips of the guinea pig also showed relaxation, as in the colonic strips, having been exposed to the large dose of 5-HT or phenoxybenzamine. This effect, however, was not obsered in the case of the rabbit ileum. 7) The property of the action-site of 5-HT in the tortoise intestine seemd to be different from the 5-HT receptors which have been revealed by several investigators. 8) Adrenergic component seemed to be participated in the inhibitory effect of 5-HT on the colon of the rat and rabbit.

• Biomolecules & Therapeutics
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• v.8 no.4
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• pp.318-324
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• 2000

We have examined inhibitory erects on gasritis using omeprazole-cholestyramine resinate, which has been developed to increase the stability of omeprazole, the well-known proton pump inhibitor, in an acidic condition. To test the pharmacological action of this, we investigated the effect of omeprazole-cholestyramine resinate on indomethacin-induced gastritis in rats. Omeprazole was used as a reference drug. Orally administered omeprazole-cholestyramine resinate inhibited the indomethacin-induced gastritis in a dose-dependent manner. The inhibitory effect of omeprazole-cholestyramine resinate on the gastritis was similar to that of reference drug. In addition, rectal adminstration of the omeprazole-cholestyramine resinate inhibited the indomethacin-induced gastritis in a dose-dependent manner. The inhibitory effect of omeprazole-cholestyramine resinate was equipotent to reference drug. The basal gastric acid secretion was decreased when it was administered either orally or rectally. This inhibition of omfprazole-cholestyramine resinate was similar to that of omeprazole. These data suggest that omeprazole-cholestyramine resinate inhibit the gastritis in rats, and are comparable to omeprazole available in market.

• Journal of Yeungnam Medical Science
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• v.17 no.2
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• pp.123-128
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• 2000

Purpose: This study was aimed to develop a new vaginal applicator(Shin's Applicator) for 2-channel high-dose rate vaginal brachytherapy to evaluate uniformity of surface dose, and to present 3-dimensional dose distribution of the applicator. Methods: Shin's Applicator was inexpensively constructed using human soft tissue equivalent acrylic bar. We evaluated dose uniformity along the applicator surface using film densitometer and performed vaginal intracavitary brachytherapy after insertion of the applicator using HDR brachytherapy planning software and brachytherapy unit(Ralstron-20B). Results: Shin's Applicator allows improved dose distribution than the existing 1-channel cylinder and achieves diminished urinary bladder and rectal dose by 20%. Conclusions: From the above results, it can be concluded that Shin's Applicator may be an improved form of a vaginal applicator. Furthermore, it can be suggested that this applicator has an advantage, for it prevents vaginal stenosis after radiation therapy and can be used as a disposable vaginal dilator. Further follow up examination with radiological study may be helpful to evaluate the therapeutic efficacy of this applicator.

• Radiation Oncology Journal
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• v.32 no.3
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• pp.187-197
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• 2014

Purpose: We aimed to analyze the treatment outcome and long-term toxicity of 70 Gy hypofractionated intensity-modulated radiotherapy (IMRT) for localized prostate cancer using a customized rectal balloon. Materials and Methods: We reviewed medical records of 86 prostate cancer patients who received curative radiotherapy between January 2004 and December 2011 at our institution. Patients were designated as low (12.8%), intermediate (20.9%), or high risk (66.3%). Thirty patients received a total dose of 70 Gy in 28 fractions over 5 weeks via IMRT (the Hypo-IMRT group); 56 received 70.2 Gy in 39 fractions over 7 weeks via 3-dimensional conformal radiotherapy (the CF-3DRT group, which served as a reference for comparison). A customized rectal balloon was placed in Hypo-IMRT group throughout the entire radiotherapy course. Androgen deprivation therapy was administered to 47 patients (Hypo-IMRT group, 17; CF-3DRT group, 30). Late genitourinary (GU) and gastrointestinal (GI) toxicity were evaluated according to the Radiation Therapy Oncology Group criteria. Results: The median follow-up period was 74.4 months (range, 18.8 to 125.9 months). The 5-year actuarial biochemical relapse-free survival rates for low-, intermediate-, and high-risk patients were 100%, 100%, and 88.5%, respectively, for the Hypo-IMRT group and 80%, 77.8%, and 63.6%, respectively, for the CF-3DRT group (p < 0.046). No patient presented with acute or late GU toxicity ${\geq}$grade 3. Late grade 3 GI toxicity occurred in 2 patients (3.6%) in the CF-3DRT group and 1 patient (3.3%) in the Hypo-IMRT group. Conclusion: Hypo-IMRT with a customized rectal balloon resulted in excellent biochemical control rates with minimal toxicity in localized prostate cancer patients.

• Journal of radiological science and technology
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• v.35 no.4
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• pp.327-333
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• 2012

Purpose: To analyze the correlation between dose volume histograms(DVH) based on organ outer wall contour and organ wall delineation for bladder and rectum, and to compare the doses to these organs with the absorbed doses at the bladder and rectum. Material and methods: Individual CT based brachytherapy treatment planning was performed in 13 patients with cervical cancer as part of a prospective comparative trial. The external contours and the organ walls were delineated for the bladder and rectum in order to compute the corresponding dose volume histograms. The minimum dose in 0.1 $cm^3$, 1 $cm^3$, 2 $cm^3$, 5 $cm^3$, 10 $cm^3$ volumes receiving the highest dose were compared with the absorbed dose at the rectum and bladder reference point. Results: The bladder and rectal doses derived from organ outer wall contour and computed for volumes of 2 $cm^3$, provided a good estimate for the doses computed for the organ wall contour only. This correspondence was no longer true when large volumes were considered. Conclusion: For clinical applications, when volumes smaller than 5 $cm^2$ are considered, the dose-volume histograms computed from external organ contours for the bladder and rectum can be used instead of dose -volume histograms computed for the organ walls only. External organ contours are indeed easier to obtain. The dose at the ICRU rectum reference point provides a good estimate of the rectal dose computed for volumes smaller than 2 $cm^2$ only for a midline position of the rectum. The ICRU bladder reference point provides a good estimate of the dose computed for the bladder wall only in cases of appropriate balloon position.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.235-246
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• 1988

A total of 93 patients with rectal cancer treated with radiotherapy at department of Radiation Oncology, Yonsei University College of Medicine, Yonsei Cancer Center between January 1974 and December 1983 are retrospectively analysed. The patients are divided into three groups as follows: I. Postoperative radiotherapy, II. Postoperative recurrent, III. Unresectable or Inoperable group. In postoperative radiotherapy group, overall 5 year survival rate is $34.8\%$ and prognostic factors are presence of obstruction and degree of differentiation. In postoperative recurrent group, overall 2 year survival rate is $7.4\%$ with median survival of 13 months and prognostic factors are RT responsiveness and sex, and the local failure rate is $22.7\%$. In unresectable or inoperable group, overall 2 year survival rate is $19.8\%$ with median survival of 12.6 months and prognostic factors are RT responsiveness and RT dose. The complications for RT are not significant and are acceptable in all patients.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.213-221
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• 2008

Purpose: The objective of this retrospective study was to identify predictive factors for the complete pathologic response and tumor downstaging after preoperative concurrent chemoradiotherapy for locally advanced rectal cancer. Materials and Methods: Between the years 2000 and 2008, 39 patients with newly diagnosed rectal cancer without prior evidence of distant metastasis received preoperative concurrent chemoradiotherapy followed by surgery. The median radiation dose was 50.4 Gy (range, $45{\sim}59.4\;Gy$)). Thirty-eight patients received concurrent infusional 5-fluorouracil and leucovorin, while one patient received oral capecitabine twice daily during radiotherapy. Results: A complete pathologic response (CR) was demonstrated in 12 of 39 patients (31%), while T-downstaging was observed in 24 of 39 patients (63%). N-downstaging was observed in 18 of 28 patients (64%), with a positive node in the CT scan or ultrasound. Two patients with clinical negative nodes were observed in surgical specimens. The results from a univariate analysis indicated that the tumor circumferential extent was less than 50% (p=0.031). Moreover, the length of the tumor was less than 5 cm (p=0.004), while the post-treatment carcinoembryonic antigen (CEA) levels were less than or equal to 3.0 ng/mL (p=0.015) and were significantly associated with high pathologic CR rates. The univariate analysis also indicated that the adenocarcinoma (p=0.045) and radiation dose greater than or equal to 50 Gy (p=0.021) were significantly associated with high T-downstaging, while a radiotherapy duration of less than or equal to 42 days (p=0.018) was significantly associated with N-downstaging. The results from the multivariate analysis indicated that the lesser circumferential extent of the tumor (hazard ratio [HR] 0.150; p=0.028) and shorter tumor length (HR, 0.084; p=0.005) independently predicted a higher pathologic CR. The multivariate analysis also indicated that a higher radiation dose was significantly associated with higher T-downstaging (HR, 0.115; p=0.025), while the shorter duration of radiotherapy was significantly associated with higher N-downstaging (HR, 0.028; p=0.010). Conclusion: The circumferential extent of the tumor and its length was a predictor for the pathologic CR, while radiation dose and duration of radiotherapy were predictors for tumor downstaging. Hence, these factors may be used to predict outcomes for patients and to develop further treatment guidelines for high-risk patients.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.61-66
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• 2012

Purpose: The purpose of this study is to compare plans prescribed to point A with these prescribed to point H recommended by ABS (American Brachytherapy Society) in high dose rate intracavitary brachytherapy for cervical carcinoma. Materials and Methods: This study selected 103 patients who received HDR (High Dose Rate) brachytherapy using tandem and ovoids from March 2010 to January 2012. Point A, bladder point, and rectal point conform with Manchester System. Point H conforms with ABS recommendation. Also Sigmoid colon point, and vagina point were established arbitrarily. We examined distance between point A and point H. The percent dose at point A was calculated when 100% dose was prescribed to point H. Additionally, the percent dose at each reference points when dose is prescribed to point H and point A were calculated. Results: The relative dose at point A was lower when point H was located inferior to point A. The relative doses at bladder, rectal, sigmoid colon, and vagina points were higher when point H was located superior to point A, and lower when point H was located inferior to point A. Conclusion: This study found out that as point H got located much superior to point A, the absorbed dose of surrounding normal organs became higher, and as point H got located much inferior to point A, the absorbed dose of surrounding normal organs became lower. This differences dose not seem to affect the treatment. However, we suggest this new point is worth being considered for the treatment of HDR if dose distribution and absorbed dose at normal organs have large differences between prescribed to point A and H.

• Journal of the Korean Society of Radiology
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• v.7 no.6
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• pp.409-414
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• 2013

In this study, we evaluated to the superiority of treatment techniques on prostate cancer, apply to each other treatment techniques-3D conformal therapy versus IMRT-using dose distribution and dose coverages. Obtained 10 patients CT simulation, divided tumor volume and critical organs. Prescription dose was 80 Gy on tumor volume and Each of plans was set by two different plans. As a result, Dose coverage was superior to IMRT. The IMRT's tumor absorbed dose(100.2%) was close to prescription doses. Normal tissue(bladder, rectal, bowel Lt Rt fumoral head) absorbed dose rate was superior. In other words, the radiation therapy of prostate cancer with intensity modulated radiation therapy was better than conformal radiation therapy on dose.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.89-97
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• 2021

Purpose: The purpose of this study is to compare and evaluate the dose change according to the gas volume variations in the rectum, which was not included in the treatment plan during radiation therapy for cervical cancer. Materials and methods: Static Intensity Modulated Radiation Therapy (S-IMRT) using a 9-field and Volumetric Modulated Arc Therapy (VMAT) using 2 full-arcs were established with treatment planning system on Computed Tomography images of a human phantom. Random gas parameters were included in the Planning Target Volume(PTV) with a maximum change of 2.0 cm in increments of 0.5 cm. Then, the Conformity Index (CI), Homogeneity Index (HI) and PTV D_max for the target volume were calculated, and the minimum dose (D_min), mean dose (D_mean) and Maximum Dose (D_max) were calculated and compared for OAR(organs at risk). For statistical analysis, T-test was performed to obtain a p-value, where the significance level was set to 0.05. Result: The HI coefficients of determination(R²) of S-IMRT and VMAT were 0.9423 and 0.8223, respectively, indicating a relatively clear correlation, and PTV D_max was found to increase up to 2.8% as the volume of a given gas parameter increased. In case of OAR evaluation, the dose in the bladder did not change with gas volume while a significant dose difference of more than D_mean 700 cGy was confirmed in rectum using both treatment plans at gas volumes of 1.0 cm or more. In all values except for D_mean of bladder, p-value was less than 0.05, confirming a statistically significant difference. Conclusion: In the case of gas generation not considered in the reference treatment plan, as the amount of gas increased, the dose difference at PTV and the dose delivered to the rectum increased. Therefore, during radiation therapy, it is necessary to make efforts to minimize the dose transmission error caused by a large amount of gas volumes in the rectum. Further studies will be necessary to evaluate dose transmission by not only varying the gas volume but also where the gas was located in the treatment field.