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Biomedical subjects

W Y Lin

Publications and source records attributed to W Y Lin.

At least 109 records · Page 6Linked to original sources
PubMed1996

Radiolabelling of Lipiodol with generator-produced 188Re for hepatic tumor therapy.

In this study we prepared and analyzed the biodistribution of 188Re-labelled Lipiodol ([188Re]-Lipiodol) in rats after intrahepatic arterial injection. EDTB was synthesized by condensation of 1,2-benzenediamine and ethylenediaminetetraacetic acid (EDTA). The labelling efficiency of [188Re] Lipiodol was determined to be greater than 97% by ITLC developed with n-hexane. Following incubation of the [188Re] Lipiodol with an equal volume of serum at 37 degrees C for 48 h, ITLC indicated good in vitro stability. Approximately 7.4 MBq [188Re] Lipiodol was injected in each rat via the hepatic artery and samples of liver, spleen, muscle, lung, kidney, bone, whole blood and testis were obtained. [188Re] Lipiodol tissue concentrations showed that after 1 h intrahepatic injection most of the radiotracer was retained in the liver, and was eliminated slowly with a biological half-life of 33.5 h. Radioactvity levels in the lung, kidney and blood were moderate at 1 h, and declined rapidly over time. In the spleen, muscle, testis and bone, radiation levels were insignificant. These initial results indicate that -188Re- Lipiodol may be a potential radiopharmaceutical agent for the treatment of liver tumors.

Animals↗
PubMed1996

Short-term hazards of low-dose radioiodine ablation therapy in postsurgical thyroid cancer patients.

During the last two decades, there has been a trend to use low-dose I-131 ablation therapy in patients with thyroid carcinoma without metastases. However, information regarding the incidence of acute adverse reactions in patients after low-dose radioiodine therapy has not been reported. In this study, the acute radiation effects after low-dose radioiodine ablation therapy in postsurgical differentiated thyroid cancer patients was evaluated. Fifty-six patients with differentiated thyroid cancer were prospectively evaluated. None of these patients had evidence of a distant metastasis. All patients received 40 mCi (1480 MBq) I-131 MIBG orally and were evaluated for symptoms and signs by a physician on the second and seventh days after therapy. Xerostomia and nausea were the most common complaints with the same incidence rate of 5.35%. Gastralgia occurred at a frequency of 3.57%. Pain in the thyroid bed, tenderness over a parotid gland, submandibular glands, change in taste, and vomiting all were found at a frequency of 1.78%. Maximum reactions generally occurred 24-48 hours after therapy. All the symptoms except for xerostomia resolved completely in most patients within a week. In comparison with high-dose ablation therapy published in the literature, the incidence of radiation reactions in low-dose radioiodine therapy was much lower. It was concluded that in patients without lymph node or distant metastases, low-dose I-131 MIBG therapy may be recommended to avoid the high incidence of local complications after high-dose treatment.

3-Iodobenzylguanidine↗
PubMed1996

Serial changes in regional blood flow in the cerebrum and cerebellum of stroke patients imaged by 99Tcm-HMPAO SPET.

Luxury perfusion is a well-known phenomenon that can mask ischaemic lesions in patients with cerebral infarction, thus making diagnosis difficult. In this study, we evaluated the incidence of luxury perfusion over a 3-week period following a stroke episode. The usefulness of crossed cerebellar diaschisis (CCD) as a complementary feature in the diagnosis of cerebral infarction was also evaluated using 99Tcm-hexamethylpropyleneamine oxime (99TcmHMPAO) brain single photon emission tomography (SPET). Twelve patients diagnosed as having a hemispheric ischaemic stroke of the middle cerebral arterial territory were enrolled in the study. Each patient underwent a total of four 99Tcm-HMPAO brain SPET examinations, 1 day, 1 week, 2 weeks and 3 weeks following the stroke episode. Our results show that the incidence of luxury perfusion was 67% (8/12) after 1 week, 75% (9/12) after 2 weeks and 83% (10/12) after 3 weeks. The incidence of CCD was 33% (4/12) after 1 day, 50% (6/12) after 1 week, 42% (5/12) after 2 weeks and 33% (4/12) after 3 weeks. We conclude that the detection of cerebral infarction is difficult 2 weeks or more after a stroke episode. The interval between the stroke episode and examination must be considered when reading the 99Tcm-HMPAO image. In addition, CCD may be helpful for the diagnosis of cerebral infarction within the first week after a stroke episode, especially in cases of an unidentified ischaemic region on the 99Tcm-HMPAO hemispheric image. However, the value of CCD is limited 2 weeks or more following the stroke episode.

Aged↗
PubMed1996

The influence of two bone agents (99Tcm-pyrophosphate and 99Tcm-methylenediphosphonate) on quantitative sacroiliac joint scintigraphy.

Bone scintigraphy is an extremely sensitive method for the detection of focal bone disease. In many hospitals, quantitative sacroiliac joint scintigraphy is still a routine procedure in detecting sacroiliitis. In previous studies, both 99Tcm-methylenediphosphonate (99Tcm-MDP) and 99Tcm-pyrophosphate have been used for bone imaging. 99Tcm-pyrophosphate is eliminated more slowly than 99Tcm-MDP from the circulation and gives a higher background activity. We wished to discover the sacroiliac/sacral ratio (SI/S ratio) changes when using different bone agents. The aim of this study was to evaluate differences in SI/S ratios between the two bone agents. Forty-six control subjects, aged 31-50 years, with no history of back pain, scoliosis, kyphosis, joint pain, arthritis, lesions within the pelvis, chemotherapy or systemic diseases such as diabetes or systemic lupus erythematosis, were included in the study. A posterior planar image of the pelvis was performed to calculate the SI/S ratio 3 h after the injection of 740 MBq 99Tcm-MDP or 99Tcm-pyrophosphate. Twenty-five subjects were studied with 99Tcm-MDP and 21 with 99Tcm-pyrophosphate. We found the SI/S ratios using 99Tcm-MDP to be slightly higher than those using 99Tcm-pyrophosphate, especially on the left side, but this difference was not statistically significant (P-values > 0.1 on both sides using Student's t-tests for unpaired data).

Adult↗
PubMed1996

Hepatic artery injection of Yttrium-90-lipiodol: biodistribution in rats with hepatoma.

UNLABELLED: In this study, we analyzed the biodistribution of 90Y-lipiodol in rats with liver tumors (hepatoma) following hepatic arterial injection. METHODS: Sixteen male Sprague-Dawley rats with liver tumors were killed at 1, 24, 48 and 72 hr (four rats at each time) after injection of approximately 0.1 mCi 90Y-lipiodol through the hepatic artery, respectively. Samples of tumor, liver, spleen, skeletal muscle, lung, kidney, bone, whole blood and testis were obtained and counted to calculate the tissue concentrations (%ID/g). RESULTS: We found that the radioactivity in the liver tumor was high at 1 and 24 hr and then declined slowly. The biological half-time was 84.1 hr. The radioactivity in normal liver tissue was also high at 1 hr but was significantly lower than that in the tumor. The biological half-time was 38.5 hr. The ratio of tissue concentration between liver tumor and normal liver tissue (T/N ratio) was 3.03 at 1 hr and rose to 6.45 at 72 hr. The radioactivity in the lung was almost as high as in normal liver tissue at 1 hr and declined rapidly with a biological half-time of 25.6 hr. The activity levels of the kidney were moderate at 1 hr and remained at almost the same level throughout the study. A moderate concentration of radioactivity in bone was noted within the first 24 hr. The concentration, however, rose over the ensuing time. The concentration of radioactivity in skeletal muscle, spleen, testis and whole blood was quite low. CONCLUSION: Following hepatic arterial injection of 90Y-lipiodol, tracer uptake in liver tumor was high and tumor retention was lengthy. Consequently, large radiation doses could be delivered to the tumor. We suggest that 90Y-lipiodol is a potential agent in the treatment of liver malignancy.

Animals↗
PubMed1996

Serum prostate-specific antigen in healthy Chinese men: establishment of age-specific reference ranges.

The purpose of this study is to establish the normal range of serum prostate-specific antigen (PSA) and to evaluate the influence of age in a population of healthy Chinese men. Subjects with PSA concentration of less than 4.0 ng/ml and normal digital rectal examination (DRE) or PSA level greater than 4.0 ng/ml and/or abnormal results of DRE with negative biopsy were defined as clinically free of prostate cancer. A total of 1008 men aged between 21 and 80 years of age fulfilled the criteria of establishing the upper limits for PSA levels. The population was grouped by age decades. The 95th percentile was determined as the upper limit of normal (reference range) for each 10-year age group for the serum PSA concentration. Our data showed that the upper limit of normal (95th percentile) for the serum PSA concentration increases with age. It is 1.92 ng/ml for men 21 to 30 years of age. 1.85 ng/ml for men 31 to 40 years of age, 2.59 ng/ml for men 41 to 50 years of age, 3.31 ng/ml for men 51 to 60 years of age, 5.03 ng/ml for men 61 to 70 years of age and 5.73 ng/ml for men 71 to 80 years of age. In conclusion, the serum PSA concentration is directly correlated with patient age. The age-specific reference ranges should be established so as to increase diagnostic specificity in older men and increase diagnostic sensitivity in younger men and then the PSA assay can become more efficient as a screening test for prostatic cancer.

Adult↗
PubMed1996

Sequential pulmonary effects of radiotherapy detected by Tc-99m DTPA radioaerosol inhalation lung scintigraphy.

Lung damage after radiation therapy in 39 female patients diagnosed with right breast cancer was measured by Tc-99m DTPA radioaerosol inhalation lung scintigraphy (DTPA). The clearance rate of Tc-99m DTPA in the lungs was presented as the clearance rate (k; %/min) of the time-activity curve of the dynamic lung images. All patients underwent simple mastectomy, and postoperative radiation of approximately 50 Gy. We divided the patients into three groups according to the interval of time between the date of irradiation and the lung scintigraphy: group 1 included 12 patients who were examined within three months after irradiation, group 2 included 16 patients who were examined 3 to 9 months after irradiation, and group 3 included 11 patients who were examined more than 9 months after irradiation. In addition, 10 age matched normal women were included as the control. The clearance of the right lung was 0.73 +/- 0.13 for normal controls, 0.94 +/- 0.24 for group 1, 1.11 +/- 0.39 for group 2, and 0.69 +/- 0.21 for group 3. In this small series of patients with breast cancer, the results suggest that lung damage may occur within the first three months after irradiation. After three months, lung damage becomes more significant and the clearance of Tc-99m DTPA in the lungs becomes faster. However, the clearance rate declines markedly after 9 months, which is assumed to result from the recovery of lung tissue from acute irradiation damage or from pulmonary fibrotic change after radiation therapy, or from a combination of both.

Administration, Inhalation↗
PubMed1995

Identification of 'molten globule'-like state in all beta-sheet protein.

The cardiotoxin analogue III (CTX III), isolated from the Taiwan Cobra venom (Naja naja atra), is a sixty amino acid, all beta-sheet protein. The 2,2,2-trifluoro ethanol (TFE) induced unfolding of CTX III is studied under acidic conditions (pH 2.5). Using circular dichroism, 1-anilino-8-napthalene sulphonic acid binding and NMR experiments, it is shown that stable, partially structured state(s) ['molten globule'-like state] is formed between 50 and 80% TFE concentrations. The protein was found to exist in an unfolded state in 80% TFE containing 2M urea. The TFE induced unfolding process is shown to be completely reversible. In the 'molten globule' state of CTX III in 80% TFE, though portion(s) of the backbone of the protein assume helical conformation, most of the original beta-sheet secondary structural elements in the protein are intact. In our opinion, this is the first report of the identification of a 'molten globule'-like state in the unfolding pathway of an all beta-sheet monomeric protein.

Anilino Naphthalenesulfonates↗
PubMed1995

Rhenium-188 sulphur colloid as a radiation synovectomy agent.

Radiation synovectomy has been shown to be an effective treatment for the rheumatoid arthritic knee. In this study, we evaluated the suitability of rhenium-188 as a radiation synovectomy agent. In addition, we were successful in labelling sulphur colloid with 188Re. In vitro stability tests revealed that more than 95% of the 188Re remained in colloid form over a 3-day period. Intra-articular injection of 188Re sulphur colloid into arthritic rabbit joints was followed by gamma camera imaging to quantify the leakage. The mean retention percentages of 188Re colloid in arthritic knees were 93.7% (+/- 1.4%), 90.8% (+/- 1.7%) and 87.2% (+/- 0.6%) at 1 h, 1 day and 2 days, respectively. A biodistribution study of the arthritic rabbits revealed that the highest activity outside the knees was in the liver and the kidneys. Our preliminary results indicate that 188Re sulphur colloid may be an effective radiopharmaceutical for radiation synovectomy.

Animals↗
PubMed1995

Preparation and biodistribution of yttrium-90 Lipiodol in rats following hepatic arterial injection.

In this study, we labelled Lipiodol with yttrium-90 and analysed the biodistribution in rats after intrahepatic arterial injection. An RP-18 column (E. Merck) was used to separate 90Y from strontium-90. 90Y was retained on the column, which had been pretreated with yttrium-selective extraction reagent, di(2-ethylhexyl) phosphate, while 90Sr was washed out. A hexadentate nitrogen-donor chelating ligand N,N,N',N'-tetrakis(2-benzymidazolylmethyl)-1,2-ethanediamine (EDTB) was synthesized by condensation of 1,2-benzenediamine and ethylene diamine tetra-acetic acid (EDTA). Lipiodol was covalently conjugated with EDTB. The final product was obtained by eluting the retained 90Y from the RP-18 column with EDTB-Lipiodol. Sixteen male rats (Sprague-Dawley) were sacrificed at 1 h, 24 h, 48 h and 72 h (four rats at each time) after injection of approximately 0.1 mCi 90Y-Lipiodol via the hepatic artery. Samples of liver, spleen, muscle, lung, kidney, bone, whole blood and testis were obtained and counted to calculate the tissue concentrations. In addition, labelling efficiency and in vitro stability were determined by ITLC methods. We found that at 1 h after intrahepatic injection, most of the radiotracer was retained in the liver, but it was eliminated gradually over a few days. The radioactivity level in the lung was fair at 1 h and remained at roughly the same level throughout the study. Radioactivity in the kidney and spleen reached a relatively high level at 24 h, but declined rapidly.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Evaluation of arthritis in Reiter's disease by bone scintigraphy and radiography.

Tc-99m MDP bone scans were used to evaluate the articular inflammation in 38 patients with Reiter's disease and compared with clinical examination and radiologic findings. Our data showed that Reiter's disease predominantly involves the lower limbs, especially the heels, which may be a characteristic feature of Reiter's disease. Bone scans revealed a high diagnostic sensitivity in the detection of clinical arthritis in all peripheral joints, especially in the small joints of the four limbs. The diagnostic sensitivity of radiography was generally lower than bone scintigraphy. In the presence of positive radionuclide findings, clinical arthritis was found in most joints. The scintigram, however, detects a greater number of abnormalities than does clinical assessment in the sternoclavicular joints, shoulders, metacarpophalangeal joints, and tarsals. Because of its high sensitivity, bone scintigraphy is capable of detecting subclinical arthritis, and might provide more objective evidence of early inflammatory joint disease and additional information regarding the pattern of joint involvement. In view of the advantages of low patient radiation exposure, high sensitivity, and the ability to survey the whole body, we consider bone scintigraphy as useful and better than radiography in the detection of early articular inflammation and in establishing the extent and pattern of arthritis in Reiter's disease.

Adolescent↗
PubMed1995

Evaluation of tissue perfusion by the Xe-133 washout method in lower limbs of patients with noninsulin-dependent diabetes mellitus.

Ischemia is thought to be a major component in the pathogenesis of foot problems. The authors use the Xe-133 washout method to evaluate the blood perfusion of muscle tissue in the lower legs of patients with noninsulin-dependent diabetes mellitus (NIDDM). Eighty-five male patients with NIDDM ranging in age from 51 years to 79 years (mean, 66.5 years) and 47 nondiabetic control males with a matched age ranging from 52 years to 82 years (mean, 64.5 years) were included in this study. None of the diabetics had a history or presentation of peripheral vascular disease in the lower limbs. The patients were separated into groups according to the duration of the disease and condition of blood sugar control. The Xe-133 washout method was performed in the anterior tibial muscle of all the subjects. According to a Student's t-test, the tissue perfusion were of significant difference between 1) NIDDM and normal controls (1.98 +/- 1.39 ml/100 g/minute versus 2.85 +/- 1.35 ml/100 g/minute), 2) good and poor blood sugar control (2.36 +/- 1.58 versus 1.51 +/- 0.94), and 3) long and short disease durations (1.50 +/- 0.78 versus 2.35 +/- 1.63). It is concluded that the tissue perfusion in the lower legs of patients with NIDDM is significantly decreased and related to the duration of the disease and condition of blood sugar control. This may contribute to the high incidence of foot gangrene and limb loss in patients with NIDDM.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Effects of inhalation of steroids on lung permeability in patients with asthma.

This study evaluated the effect of inhalation of steroids on lung permeability in patients with asthma by measuring the clearance of Tc-99m DTPA aerosol from the alveolar to vascular space. Twenty patients with asthma were studied in the supine position with a gamma camera and the clearance half time (T 1/2) was calculated. The base line lung permeability study was performed before treatment with inhalation of 100 micrograms beclomethasone dipropionate four times daily for 1 week, then the study was repeated. After treatment with inhalation of steroid, there was a change in T 1/2 from 76.4 +/- 37.4 minutes to 86.6 +/- 48.2 minutes (P = 0.08). This preliminary study suggests that lung permeability is not altered by inhaled steroid therapy.

Administration, Inhalation↗
PubMed1995

Radionuclide imaging in extraskeletal myxoid chondrosarcoma.

The authors present a case of extraskeletal myxoid chondrosarcoma. The MR study clearly showed the extent of the tumor and a "rings and arcs" pattern appeared after Gadolinium-DTPA administration in the T1 weighted images. Dynamic Tc-99m MDP and Tc-99m DTPA scintigraphy showed increased blood flow in the mass. The delayed 3-hour images demonstrated moderate Tc-99m MDP uptake, but intense Tc-99m DTPA accumulation in the tumor. Surprisingly, the Ga-67 scan failed to demonstrate the tumor.

Adult↗