Vol.11,

The theraputic effectiveness of primary coronary stenting was evaluated and compared with that of intravenous thrombolysis for acute myocardial infarction (AMI) using ^99mTc-MIBI myocardial SPECT imaging. 42 patients with AMI were undergone primary coronary stenting (stenting group, 23 patients) or intravenous throm-bolysis therapy (thrombolysis group, 19 patients). ^99mTc-MIBI myocardium SPECT imaging was performed before and 1 week after stenting or thrombolysis therapy. The left ventricular myocardium of each patient was divided into 20 segments. The semiquantitative score of myocardial ^99mTc-MIBI uptake was expressed with a five-point scoring system: 0 = normal; 1 = equivocal; 2 = mild defect; 3 = severe defect; 4 = absence of activity. The scores of scanning before stenting or intravenous throm-bolysis was SBS. The scores of scaning after stenting or intravenous thrombolysis was SAS. Deducting SAS from SBS was SDS. A comparison was made between the stenting group and thrombolysis group: SBS was 41.3±9.8 and 39.4±7.9 (t=1.2, p < 0.05); SAS was 17.8±6.4 and 27.3±6.7 (t=5.8, p <0.01); SDS was 24.5±4.2 and 12.2±2.3 (t = 7.3, p <0.01). In the 193 defect segments before stenting, 106 segments (54.9%) restored to normal after stenting. In the 149 defect segments before intravenous thrombolysis, 61 segments (40.9%) restored to normal after thrombolysis therapy. Comparing between stenting group and thrombolysis group in the improved rate of myocardial perfusion defect scores there was a significant difference (p <0.01). ^99mTc-MIBI myocardial SPECT imaging has been proved to be an objective parameter for evaluating the therapeutic effectiveness of the stenting and the intravenous thrombolysis in the treatment of AMI. The results indicated that primary coronary stenting seems to be more effective than intravenous thrombolysis.

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The aim of this work has been to evaluate whether a diagnostic protocol based on the joint use of mammography and ^99mTc-MIBI scintimammography can help to distinguish the lesions and to reduce the number of biopsies required in patients with suspected breast cancer. A total of 58 women were evaluated by palpation, mammography, scintimammography. Twenty-four patients were scintimammographed with ^99mTc-MIBI at 10 min after injection. Thirty-four patients were taken double-phase scintimammography with ^99mTc-MIBI 10 min and 60~90 min after injection. Based on mammography, the supicion degrees of malignancy were rated, and 30 results of malignancy were confirmed by histopathology. Based on mammography, 18 lesions were considered to be most probably benign (of which 3 were histopathologi-cally breast cancer), 19 as indeterminate (of which 9 were histopathologically breast cancer), and 21 as malignant (of which 18 were histopathologically breast cancer). The results of early and delayed phases ^99mTc-MIBI scintimammography were the same. The sensitivity, specificity and accuracy of scintimammography were 74.29%, 86.96% and 79.31%, respectively. Scintimammography gave 16 correct diagnosis in 19 mammogram indeterminate (84.2%) and demonstrated 5 out of 8 cases axillary lymph nodes metastasis (62.5%). These studies show that ^99mTc-MIBI scintimammography used as a complementary testing technique to mammography is useful in the examination of patients with suspected breast cancer. The adoption of a joint mammography-scintimammography diagnostic protocol could considerably reduce the number of biopsies performed in patients with lesions of indeterminate mammographic suspicion of malignancy.

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This study was designed to evaluate the efficacy and safety of ^99mTc labeled human IgG as the tracer for detection of focal inflammatory lesion in abdomen. 61 inpatients with 20 documented cases of pelvicellulitis, 41 cases of inflammatory bowel diseases were studied. All their diagnosis were based upon clinical signs and various types of laboratory data and other imaging modalities. 370~740MBq/mg of ^99mTc-HIgG was injected intravenously. The whole body scan (Ant and Post views) were obtained 1, 2, 4, 6, 24 hours after injection, delayed imaging were repeated if necessary. Wherever abnormal areas, multiple spot views were added. ^99mTc-HIgG was avidly taken up by acute pelvis inflammation lesions and performed less well in 2 chronic cases, so the positive rate was 90%. 21 out of the 22 ulcerative colitis were positive, the positive rate was 93%. 17 out of the 19 Crohn's were positive, the positive rate was 89%. All the negative cases were not active ones. With respect to the activity of the disease, the positive rate of ^99mTc-HIgG scan in ulcerative colitis was 100% equal to that of endoscopy. In Crohn's disease the positive rate was 100%, while endoscopy and X-ray were 30% and 94% respectively. If both diseases were in their relief stage,the scans were normal. Thus ^99mTc-HIgG is proved to be effective in detecting the focal site of inflammation in the abdomen. Providing clinically useful assessment of disease activity and patient's response to therapy, ^99mTc-HIgG scintigraphy is safe, convenient with no side effects. Physiological accumulation in some organs such as the liver makes it difficult to localize.

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To evaluate the degree of pulmonary artery hypertension (PAH) and its significance, pulmonary perfusion tomographic imaging (PPTI) and radioimmunoassay of plasma atrial nateiuretic. peptide (ANP) levels were examined in different stages of rabbit PAH models, controlled with cardiac catheterization. When the PAH was mild. ANP levels were not significantly changed (t=1, p >0.05). The mean pulmonary artery pressures (mPAP) measured by catheterization had no significant change, but there was a significant increase of the ratio of dorsal/abdominal counts using pulmonary perfusion tomographic imaging (PPTI) (t=2.5, p <0.05). The ANP levels rose when PAH was moderate or severe, and the difference was significant compared with the control group (t=4 and 6.5, p <0.05). The other two methods also showed significant changes (p <0.01). There was positive correlation between the results of ANP/PPTI, ANP/catheterization, and PPTI/catheterizations (p <0.01). These results suggest that ANP levels can assess the degree of the PAH as a simple method, but it is not as sensitive as that of the PPTI in mild PAH.

436

The relationship between dopamine D₂ receptors and brain perfusion in hemi-parkinsonism rats was studied. Hemi-parkinsonism rats were made by stereotaxic 6-hydroxy dopamine (6-OH-DA) lesions in substantia nigra(SN) and ventral tegmental area(VTA), apomorphine (Apo) which could induced the successful model rat rotates toward the intact side was used to select the rats, ¹²⁵I-IBZM ex-vivo autoradiography analysis and ^99mTc-HM-PAO regional cerebral biodistribution were used to evaluate D₂ receptors and cerebral blood flow. The HPLC-ECD were used to measure striatum DA and its metabolites content. The lesioned side striatum DA and its metabolites HVA DOPAC reduced significantly than that of the intact side and seudo-operated group, striatum/cerebellum ¹²⁵I-IBZM uptake ratio was 8.04±0.71 in lesioned side of hemi-parkinsonism rats, significantly increased compared with the intact side and the seudo-operated group(p <0.05), 30.11±4.53% enhancement as compared to the intact side, and also show good correlation with 30 min Apo induced rotation numbers (r=0.98), the regional cerebral blood flow study didn't show significant difference between bilateral brain cortex area(p >0.05). These results indicated that in the 6-OH-DA lesioned side DA content decreased significantly and an up-regulation of striatum D₂ receptor binding sites was induced in hemi-parkinsonism rats, which showed good correlation with rotation behavior induced by Apo. Comparing with cerebral blood flow, D₂ receptor reflected by IBZM seems to be more specific and earlier to detect the cerebral functional impairment in experimental hemi-parkinsonism.

293

The clinical prospect of radioiodinated SP-4 as an atherosclerotic plaque imaging agent was studied. The SP-4 was synthesized by a solid phase method and identified by an amino acid analysis after purification with HPLC. SP-4 was labeled with ¹³¹I and ¹²⁵I by the Chloramine-T method and purified through Sephadex G-25 column. Tewlve New Zealand rabbits were divided into an atherosclerotic group (n = 7, AR) and a control group (n = 5. NR ). All of the atherosclerotic rabbits were intravenous administrated with bovine serum albumin, then fed with high cholesterol and fat diet. ¹²⁵I-SP-4 was intravenous administrated to the rabbits of both groups. The biodistribution of ¹²⁵I-SP-4 in rabbits was investigated. The uptakes (%ID/g) in blood and thoracic aorta and abdominal aorta were calculated 4 hours postinjection. Macroautoradiography and microautoradiography were performed in 2 AR atheroscle-rotic abdominal aortas. The clearance of radioactivity from plasma was very rapid. ¹²⁵I-SP-4 was mainly excreted through kidneys. The radioactive uptakes of abdominal aorta and thoracic aorta of AR at 4hours postinjection were significantly higher than that of NR. The films of macroautoradiography showed focal accumulation of the radioactivity in the areas of a newly formed edges of atherosclerotic plaques. On the slices of microautoradiography, the obvious radioactive accumulation could be found in the atherosclerotic plaques. Thus it was seen that the SP-4 remained its biological activity after radioiodination and was located at atherosclerotic lesions, it is potentially useful as an atherosclerotic plaque imaging agent.

527

A method with several steps superior to literature has been developed for the preparation of β-methyl p-iodophenyl pentadecanoic acid(BMIPP). The synthesis and physical properties of BMIPP are described. It is characterized by IR, ¹HNMR, elemental analysis and MS. ¹²⁵I-BMIPP can be prepared by three methods: direct labeling, solid-state transfer labeling and Cu(I) assisted labeling. Cu(I) assisted labeling is simple and not necessary to purify before clinical use. It can fulfil the requirements for kit labeling.

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Tinnitus is an auditory disorder hardly assessable by clinical technology. PET imaging of the brain in 13 cases with and 10 without tinnitus was undertaken at 40 min after injection of 280~440 MBq ¹⁸F-FDG. To ensure the quality of the PET study, all cases followed a normalized procedure with visual and auditory blockage. CT/MRI imaging and routine acoustic tests were carried out in all subjects. PET revealed that an increased uptake of ¹⁸F-FDG at left med-temporal lobe (primary auditory center, PAC) present exclusively in tinnitus, regardless the side of hearing hallucination. Significant asymmetry was noted between left and right PAC, but not at other cortex area. While control cases showed no asymmetric uptake between two hemispheres. The abnormal PAC uptake did not respond to external pure sound stimulus, nor did it relate to the severity of hearing loss assessed by acoustic tests. No anatomical or morphological alteration could be proven on CT/MRI. In conclusion, PET/¹⁸F-FDG objectively revealed an increased metabolic change at left PAC in tinnitus, which is of diagnostic value; and there is evidence suggesting tinnitus is most likely induced by a functional change in the brain.

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To investigate the characteristics of expression and distribution of 5 subtypes of somatostatin receptors (SSTR1~5) in lung cancer, in situ hybridization was used to examine the expression patterns of SSTR mRNAs in 21 cases of different pathologic types of lung cancer tissues with [α-³⁵S]dATP labeled oligonucleotides of the 5 SSTR subtypes as probes. Additionally, Leica Q-500 image analysis processing system was employed for the semi-quantitatively analysis of the hybridization signals. Patterns of SSTR1~5 expression in lung cancer tissues were found as follows. SSTR2 was prominent in small cell lung cancer (SCLC), whereas in non-small cell lung cancer (NSCLC) including the adenous cancer (Ad) and the squamous cancer (Sq), the expression of SSTR1 mRNA was stronger than that of the other 4 types. The expression density of SSTR1~5 in the NSCLC was higher than the SCLC (p <0.01). The expression patterns and densities of the SSTR subtypes showed heterogeneity in different pathologic types of lung cancer. The expressions of the SSTR mRNAs in both SCLC and NSCLC indicated the positive prospects for somatostatin analog(SSA)-oriented agents in the treatment of both types of the lung cancer.

338

To calculate a safe and effective ¹⁵³Sm-EDTMP therapy dose, a whole-body scintigraphy technique for prospective individual dosimetry was developed and the results were compared with 5 h urine collection method in 20 patients with bone metastases. Anterior and posterior whole-body images were obtained 10 min and 5 h after intravenous injection of 740 MBq ¹⁵³Sm-EDTMP and the bone uptake value was determined. There is a close correlation between the bone uptake value obtained from the whole-body scintigraphy and 5 h urine collection method (r=0.93). The radiation absorption dose to red marrow was limited to 1.4 Gy and the administered activity calculated from bone uptake value by whole-body scintigraphy was 1.40~2.27 GBq (mean 1.90 GBq). If the activity was calculated according to the standard body weight of 37 MBq•kg^-1, the administered activity would be 1.75~2.41 GBq (mean 2.18). the radiation absorption dose to red marrow would be 1.37~2.27 Gy (mean 1.63 Gy), but at these doses significant myelotoxicity would be anticipated, thus emphasizing the need for individual prospective dosimetry.

420

The apoptosis of osteosarcoma cells treated with irradiation by ¹⁵³Sm-EDTMP was studied. The morphological changes in osteosarcoma cells were observed by fluorescence microscopy. It was found that osteosarcoma cells exposed with ¹⁵³Sm-EDTMP displayed significant nuclear fragmentation and marked pyknosis. With the prolongation of observing period, the membrane bound apoptotic bodies formation was observed. It should be noted, that with the lengthening of irradiation time by ¹⁵³Sm-EDTMP, the inhibition rate of proliferation of osteosarcoma cells increased progressively.

367

Objective: To study the effect of coixenolide (CXL) on irradiation of human nasopharyngeal carcinoma cell line CNE-2Z in the absence of oxygen. Methods: Microcolony formation assay was used for determining the sensitivity of CNE-2Z to γ-ray in vitro. Results: When CNE-2Z was treated with 10^-7 ~ 10^-6 mol/L of CXL, CXL shifted the radiation dose-survival curve to the left, with the decrease of D₀, D_q and N values. Radiation dose reduced 10.07%~35.69% at D37 level, the sensitizing enhancement ratios (SER) were 1.07~1.43 and 1.16~1.72 at D₀ and D_q levels respectively. Conclusion: CXL increase susceptibility of CNE-2Z to ray under hypoxic condition by the mechanism of inhibiting its sublethal damage repair. Subject words Nasopharyngeal neoplasm; Coixenolide; Radiosensitization, Hypoxic irradiation

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Human peripheral blood exposed with 188ReO4− at various radioactivities for 54h was examined to observe the chromosome and chromatin aberrations at metaphases in the mitosis of lymphocytes. The findings indicate that there is an increasing tendency of the aberration yields of both types with increasing 188ReO4− concentration and a dose dependency could be obtained. The aberration yield was best fitted by a quadratic model. Chromatin aberrations, aberration cells and chromosome fragments were fitted into a linear-regression model.

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The low dose effects induced by carbon ions on Chinese hamster V79 cells and murine melanoma B16 cells were investigated in this paper. Both cell lines were divided into four groups for irradiation: (1) control, (2) 0.02 Gy or 0.05 Gy(D1), (3) 1 Gy(D2), (4) D1+D2. The survivors and micronuclei were studied as biological endpoints. The results of group (1) and group (2) showed that there were no obvious differences on micronucleus frequency but there were significant increases when irradiation dose was 0.02Gy on colony formation efficiency. Although low dose ion irradiation could not contribute to DNA damages, it could enhance the colony formation efficiency. In the study of group (3) and (4), when the ion dose was 0.02 Gy, there were evident increases on surviving fraction and decreases on micronuclcus frequency, but there were no statistical changes on these endpoints when the ion dose was 0.05Gy. This meant that high LET radiation could induce the adaptive response of cultured cells, furthermore, in the range of inducing ion dose low dose irradiation was more profitable than high dose one.

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Though the radiation-resistant bacteria Deinococcus radiodurans (D. radiodurans) have a high resistance to the lethal and mutagenic effects of many DNA-damaging agents, the mechanisms involved in the response of these bacteria to oxidative stress are poorly understood. In this report, the superoxide dismutase (SOD) and catalase (CAT) activities produced in bacteria (D.radiodurans AS1.633) and their change caused by 20keV N⁺ beam exposure were examined. Results showed that the activities of the enzymes were increased in the case of N⁺ beam exposure from 8 × 10¹⁴ ions/cm² to 6 × 10¹⁵ ions/cm². In addition, the treatment of H₂O₂ and [CHCl₃+CH₃CH₂OH] and the measurement of absorption spectrum showed that the increase of whole SOD activity resulted from inducible activities of Mn-SOD in (a sub-type) D.radiodurans AS1.633. These results suggested that these bacteria possess inducible defense mechanisms against the deleterious effects of oxidization.

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