Mammary carcinoma was induced in rats by itravenous injection of N-methy-N-Nitrosourea. Microangiography was perfromed to evaluate the microvascular alterations in mammary carcinoma after irradiation. The tumors were givena single dose of 1.400 rads using Co-60 telethrapy unit with field size of 4 x 4 cm at 40 cm SSD. The dose ratewas 147.5 rads per minute. Microangiography was performed prior to irradiation and at one, two, and four weeksfollowing irradiation. The results are as follows: 1. Before irradiation, mammary carcinoma in rats tended to formlobules and the basic vasculature consisted of peripheral vascular pattern with central penetrating vessels. Theperipheral vascular pattern was always richer than that of the center. Irregular and tortuous vessles stretchedfrom the periphery into the center of lobule. 2. One week following irradiation, an increase in the number ofsmaller, tortuous vessels and decreased intervasular distance were obseved in the central portion of each lobule.This finding seems to be due to an improved filling of some previously existing but unfilled vessels. This maylead to improved metabolic changes and reoxygenation. 3. Later's changes of microvasculature after irradiation aretortuosity, irregularity, narrowing, abrupt tapering, fragmentation, and extravasation. These findings progressedafter a lapse of time. 4. The results can be considered as the microangiographic demonstration of the fact that reoxygenation after irradiation is mainly due to dilatation of the collapsed tumor vessels.
Animals ; Dilatation ; Microvessels ; Radiation Effects ; Rats ; Silver Sulfadiazine

Early MRI and arthroscopic findings were compared to evaluate the efficacy of the former for patients, who upon physical examination, were diagnosed with possihle acute ACL tears. MRI, taken between 1-21 days after injury, had to reveal complete ACL tears and arthroscopic surgery should have taken place 3-12 weeks after the injury for patients of this prospective study. Fifty such cases were initially catagorized according to five MRI patterns. Types I to V were separated by the following ACL tear characteristics: Enlarged and diffusely increased in signal, horizontally oriented, non-visualized, discontinuous and vertically oriented. The cases were then divided into two groups of arthroscopic findings; Group A included cases of complete ACL tearing and group B included those with intact or minimally torn ACLs. Of MRI types I through V, there were 31, 9, 5, 4, and I cases of each respectively. 37 cases resulted in complete ACL tears (21 type I, 6 type II, 5 type III, 4 type IV and 1 type V) and 13 cases were catagorized into group B, 10 of which had pattern type I and 3 of which had pattern type II. As result, types III, IV and V had a 100% Positive Predictive Value (PPV) whereas types I and II together had a 67% PPV vaiue. Division of the cases into the five pattern types in early MRI proved valuble for possible cases of acute ACL tears. MRI pattern types III, IV and V were correlated with definite complete ACL tears. However, caution must be taken for types I and II, the majority of the cases, for which there exists a significant possibility for misdiagnosis and consequently unnecessary arthroscopic surgery.
Arthroscopy ; Diagnostic Errors ; Humans ; Knee ; Magnetic Resonance Imaging* ; Physical Examination ; Prospective Studies

We have evaluated the clinical results following the 46 cases of free vascularized osteocutaneous fibular flap transfer to the tibial defect combined with soft tissue defect, which were performed from May 1982 to January 1997. In the 46 consecutive procedures of free vascularized osteocutaneous fibular flap transfer, initial bony union were obtained in the 43 grafted fibulars at average 3.75 months after operation. There were 2 cases in delayed unions and 1 in nonunion. 44 cutaneous flaps among the 46 cases were survived but 2 cases were necrotized due to deep infection and venous insufficiency. One necrotized flap was treated with latissimus dorsi free flap transfer and the other was treated with soleus muscle rotational flap. Grafted fibulas have been hypertrophied during the follow-up periods. The fracture of grafted fibula (15 cases) was the most common complication and occurred at average 9,7 months after the operation. The fractured fibulas were treated with the cast immobilization or internal fixation with conventional cancellous bone graft. In the cases of tibia and fibula fracture at recipient site, the initial rigid fixation for the fibula fracture at recipient site could prevent the fracture of grafted fibula to the tibia.
Fibula ; Follow-Up Studies ; Free Tissue Flaps ; Immobilization ; Muscle, Skeletal ; Superficial Back Muscles ; Tibia* ; Transplants* ; Venous Insufficiency

To evaluate the usefulness of computed tomography (CT) in radiotherapy treatment planning in malignant tumors of thoracic cage, the computer generated dose distributions were compared between plans based on conventional studies and those based on CT scan. 22 cases of thoracic malignancies, 15 lung cancers and 7 esophageal cancers, diagnosed and treated in Department of Therapeutic Radiology of Seoul National University Hospital from September, 1982 to April, 1983, were analyzed. In lung cancer, dose distribution in plans using AP, PA parallel opposing ports with posterior spinal cord block and in plans using box technique both based on conventional studies were compared with dose distribution using AP, PA and two oblique ports based on CT scan. On esophageal cancers, dose distribution in plans based on conventional studies and those based on CT scans, both using 3 port technique were compared. The results are as follows: 1. Parallel opposing field technique were inadequate in all cases of lung cancers, as portion of primary tumor in 13 of 15 cases and portion of mediastinum in all were out of high dose volume. 2. Box technique was inadequate in 5 of 15 lung cancers as portion of primary tumor was not covered and in every case the irradiated normal lung volume was quite large. 3. Plans based on CT scan were superior to those based on conventional studies as tumor was demarcated better with CT and so complete coverage of tumor and preservation of more normal lung volume could be made. 4. In 1 case of lung cancer, tumor localization was nearly impossible with conventional studies, but after CT scan tumor was more clearly defined and localized.
Esophageal Neoplasms ; Lung ; Lung Neoplasms ; Mediastinum ; Radiation Oncology ; Radiotherapy* ; Seoul ; Spinal Cord ; Tomography, X-Ray Computed

To obtain 7 MeV electron beam which is suitable for treatment of the chest wall after radical of modified radical mastectomy, the authors reduced the energy of electron beam by means by Lucite plate inserted in the beam. To determine the proper thickness of the Lucite plate necessary to reduce the energy of 9 MeV electron beam to 6 MeV, dosimetry was made by using a parallel plate ionization chamber in polystyrene phantom. Separation between two adjacent fields, 7 MeV for chest wall and 12 MeV for internal mammary region, was studied by means of film dosimetry in both polytyrene phantom and Humanoid phantom. The results were as follows. 1. The average energy of 9 MeV electron beam transmitted through the Lucite plate was reduced. Reduction was proportional to the thickness of the Lucite plate in the rate of 1.7 MeV/cm. 2. The proper thickness of the Lucite plate necessary to obtain 6 MeV electron beam from 9 MeV was 1.2 cm. 3. 7 MeV electron beam, 80% dose at 2cm depth, is adequate for treatment of the chest wall. 4. Proper separation between two adjacent electron fields, 7 MeV and 12 MeV, was 5mm on both flat surface and sloping surface to produce uniform dose distribution.
Film Dosimetry ; Mastectomy, Modified Radical ; Polymethyl Methacrylate ; Polystyrenes ; Thoracic Wall* ; Thorax*

The thickness of the part being irradiated is finite. Percent depth dose tables being used routinely are generally obtained from dosimetry in a phantom much thickner than usual patient. At or close to exit surface, the dose should be less than that obtained from the percent depth dose tables, because of insufficient volume for backscattering. To know the difference between the true absorbed dose and the dose obtained from percent depth dose table, the doses at or close to the exit surface were measured with plate type ionization chamber with volume of 0.5ml. The results are as follows; 1. In the case of 60Co, percent depth dose at a given depth increases with underlying phantom thickness up to the 5cm. 2. In the case of 60Co, the dose correction factor at exit surface which is less than 1, increases with part thickness and decreases with field size. 3. Exposure time may not be corrected when the part above 10cm in thickness is treated by 60Co. 4. In the case of 10MV x-ay, the dose correction factor is nearly 1 and constant for the underlying phantom thickness and field size, so the correction of monitor unit is not necessary for part thickness.
Axis, Cervical Vertebra* ; Fibrinogen ; Humans

To investigate the relationship between Radiosensitivity and postirradiation recovery in human cancer cells, a study was performed using human cancer cell lines-A549, CaSki, SNU-C5 and PCI-13. for the study of radiosensitivity, single doses of 2, 4, 6, 8, 10, 12, and 14 Gy were given and for postirradiation recovery, two fractions of 4 Gy were separated with a time interval of 0, 0.5, 1,1.5, 2, 2.5, 3, 4, 5, or 6 hours. Surviving fraction was estimated using colony forming ability. Surviving fractions at 2 Gy (SF2) were 0.496 (0.570-0.412) for A549, 0.496 (0.660-0.332) for CaSki, 0.386 (0.576-0.216) for SNU-C5, and 0.185(0.247-0.123) for PCI-13. By statistical analysis the SF2 of PCI-13 was lower significantly than those of others (p<0.05). this difference was also observed at 4,6 and 8 Gy dose levels. At 6 and 8 Gy the surviving fractions of SMU-C5 were also lower significantly than A549 and CaSki(p<0.05). By the analysis with linear quadratic model, the value of alpha for A549, CaSki, SNU-C5 and PCI-13 were 0.3016, 0.3212, 0.4327 and 0.8423, respectively, and those of betawere 0.024929, 0.02009, 0.03349 and 0.00059, respectively. So, the value of alpha showed increasing tendency with decreasing SF2.By the multitarget single hit model the values of Do for A549, CaSki, SUN-C5 and PCI-13 were 1.97, 1.97,1.46 and 0.81, respectively, and those of n were 1.53, 1.50, 1.56 and 2.28, respectively. So, the value of Do decreased with decreasing SF2. Post-irradiation recovery reached plateau at around 2 hours. Recovery ratio at plateau phase ranged from 1.2 to 4.2; the value were 1.2 for PCI-13, 3.2 for CaSki, 3.3 for SNU-C5, and 4.2 for A549. Recovery rate well correlated with SF2, and increased with increasing Do and decreasing alpha. According to above results, the intrinsic radiosensitivity was quite different among the tested cell ilnes; PCI-13 was the most sensitive and A549 and CaSki was similar. This difference of radiosensitivity is thought to be partly due to the difference in amount of postirradiation recovery. By linear quadratic model the difference of alpha values was very high, and by multitarget single hit model the difference of Do value was significantly high among four cell lines.
Cell Line* ; Humans* ; Radiation Tolerance*

DNA profiles have been increasingly used as the most reliable means to identify remains from war or mass disaster. To establish the identity with such a large set of victims, special care should be taken to correlate remains with correct family references while avoiding coincidental match between non-relatives. Therefore we address here relevant statistical and combinatorial issues in the DNA identification of mass victims. A simple and general formula for the likelihood ratio governing any potential kinship between two DNA profiles was presented, and for that purpose, the probabilities that a given relative and an individual share autosomal identical-bydescent alleles were calculated. In addition, a method dealing with the allele drop-out in kinship analysis and the estimation of a cold hit were discussed.
Alleles ; Cold Temperature ; Disasters ; DNA ; Humans

Toxoplasma gondii is an obligate intracellular protozoan parasite, which invades a wide range of hosts including humans. The exact mechanisms involved in its invasion are not fully understood. This study focused on the roles of Ca2+ in host cell invasion and in T. gondii replication. We examined the invasion and replication of T. gondii pretreated with several calcium modulators, the conoid extrusion of tachyzoites. Calmodulin localization in T. gondii were observed using the immunogold method, and Ca2+ levels in tachyzoites by confocal microscopy. In light microscopic observation, tachyzoites co-treated with A23187 and EGTA showed that host cell invasion and intracellular replication were decreased. The invasion of tachyzoites was slightly inhibited by the Ca2+ channel blockers, bepridil and verapamil, and by the calmodulin antagonist, calmidazolium. We observed that calcium saline containing A23187 induced the extrusion of tachyzoite conoid. By immunoelectron microscopy, gold particles bound to anti-calmodulin or anti-actin mAb, were found to be localized on the anterior portion of tachyzoites. Remarkably reduced intracellular Ca2+ was observed in tachyzoites treated with BAPTA/AM by confocal microscopy. These results suggest that host cell invasion and the intracellular replication of T. gondii tachyzoites are inhibited by the calcium ionophore, A23187, and by the extracellular calcium chelator, EGTA.
Animals ; Calcium/*physiology ; Calcium Channel Blockers/pharmacology ; Calmodulin/antagonists & inhibitors ; Chelating Agents/pharmacology ; Hela Cells ; Host-Parasite Relations ; Humans ; Ionophores/pharmacology ; Research Support, Non-U.S. Gov't ; Toxoplasma/drug effects/pathogenicity/*physiology

OBJECTIVE: To compare the videofluoroscopic findings between the patients with lateral medullary infarct and middle cerebral artery infarct and to investigate specific findings relevant to lateral medullary infarct. METHOD: Among patients with stroke taking videofluoroscopic study for swallowing problems, thirteen patients had a lesion in lateral medulla in imaging study and twenty-six patients in middle cerebral arterial territory. The findings of videofluoroscopic study on two groups were analyzed and compared. RESULTS: In oral phase, the ability of mastication and bolus formation were better in lateral medullary group. In pharyngeal phase, lateral medullary group revealed significantly impaired triggering of pharyngeal reflex, impaired laryngeal elevation, larger amount of residual materials, repeated swallow, delayed pharyngeal transit time, weaker pharyngeal muscle contraction, and poorer upper esophageal sphincter relaxation. Inadequate relaxation of upper esophageal sphincter was most significant factor in indicating the possibility of lateral medullary infarct (positive predictability 90.0%). Inadequate triggering of pharyngeal swallow indicated least possibility of lateral medullary infarct (negative predictability 92.3%). CONCLUSION: Lateral medullary group has the characteristics of more impaired pharyngeal function and better oral function during swallowing than middle cerebral artery group in videofluoroscopic study. Inadequate upper esophageal relaxation and triggering of pharyngeal swallow are the most predictive for lateral medullary infarct.
Deglutition ; Esophageal Sphincter, Upper ; Gagging ; Humans ; Mastication ; Middle Cerebral Artery* ; Pharyngeal Muscles ; Relaxation ; Stroke