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Biomedical subjects

W S Huang

Publications and source records attributed to W S Huang.

At least 19 recordsLinked to original sources
PubMed2006

Thallium-201 scan in evaluating thyroid nodules following equivocal fine-needle aspiration cytology.

UNLABELLED: The AIM of this prospective study was to evaluate the usefulness of the thallium-201 ( (201) Tl) thyroid scan in the detection of malignancy in cold thyroid nodules whose status was equivocal following palpation fine-needle aspiration cytology (FNAC). PATIENTS, METHODS: Fifty-one patients with clinically palpable solitary cold thyroid nodules classified as non-diagnostic or suspicious following biopsy underwent (201) Tl thyroid scans. Each scan was performed 15 min (early scan) and 3 h (delayed scan) after an intravenous administration of 74 MBq (201) Tl. Thallium uptake in the nodules was visually assessed and scored on a three point scale, with a grade of three defining malignancy. All patients underwent surgery and the histopathology of nodule tissues were compared with results of the scans. RESULTS: Fifty-one nodules were examined. Forty were benign and 11 were malignant. For early scans, the diagnostically relevant parameters were: sensitivity (100%), specificity (75%), and accuracy (80%). Corresponding findings for the delayed scan were: 91%, 98%, and 96%. CONCLUSION: The (201) Tl scan is useful for detecting malignancy in cold thyroid nodules classified as nondiagnostic or suspicious lesions by FNAC.

Biopsy, Fine-Needle↗
PubMed2003

Evaluation of the effects of methylprednisolone pulse therapy in patients with systemic lupus erythematosus with brain involvement by Tc-99m HMPAO brain SPECT.

Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in patients with systemic lupus erythematosus (SLE) with brain manifestations; however, the efficacy of MPT in SLE patients with brain involvement is still uncertain and needs to be objectively evaluated. We enrolled 15 female SLE patients with neuropsychiatric manifestations in this study. All patients had normal brain MRI and abnormal brain HMPAO-SPECT findings. Follow-up HMPAO-SPECT studies were conducted 2 weeks after MPT. Serum levels of anticardiolipin antibodies (ACA) and anti-ribosomal P antibodies (anti-P) were measured before and after MPT. Before MPT, 7 patients were positive for ACA and 7 patients were positive for anti-P. After MPT, none of the 15 patients demonstrated positive serologic findings or neuropsychiatric manifestations. Based on the follow up brain HMPAO-SPECT images following MPT, 13 patients showed disappearance of the perfusion defects and 2 patients showed partial recovery of rCBF. Brain HMPAO-SPECT imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by determining of changes in rCBF.

Adult↗
PubMed2003

Using 99mTc HMPAO brain SPECT to evaluate the effects of anticoagulant therapy on regional cerebral blood flow in primary antiphospholipid antibody syndrome patients with brain involvement-a preliminary report.

Technetium-99m hexamethylpropylene amine oxime ((99m)Tc HMPAO) brain single photon emission computed tomography (SPECT) was used to evaluate the effects of anticoagulant therapy (ACT) on regional cerebral blood flow (rCBF) in patients with primary antiphospholipid antibody syndrome (PAPS). Sixteen female PAPS patients with neuropsychiatric manifestations and hypoperfusion lesions demonstrated on initial (99m)Tc HMPAO brain SPECT images were enrolled in this study. Follow-up (99m)Tc HMPAO brain SPECT images were performed 1 month after ACT. Meanwhile, serum anticardiolipin antibodies (ACA) were measured before and after ACT. Before ACT, 14 (87.5%) patients had positive ACA. After ACT, all 16 PAPS patients showed decreased serologic findings, and their neuropsychiatric manifestations subsided. After ACT, 11 (68.8%) patients showed complete recovery of regional cerebral blood flow (rCBF) and five (31.2%) patients showed partial recovery in the follow-up (99m)Tc HMPAO brain SPECT images. This type of imaging is a logical and objective tool for measuring the effects of ACT in PAPS patients with brain involvement by determining changes in rCBF.

Adult↗
PubMed2003

Detecting abnormal regional cerebral blood flow in patients with primary Sjögren's syndrome by technetium-99m ethyl cysteinate dimer single photon emission computed tomography of the brain--a preliminary report.

Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in 32 female patients with primary Sjögren's syndrome (PSS) showing definite neuropsychiatric symptoms/signs and normal brain magnetic resonance imaging (MRI) findings. It demonstrated hypoperfusion brain lesions in 18 (56.3%) of the patients, most frequently in the parietal lobes, and appears to be a sensitive tool for this clinical application.

Adult↗
PubMed2003

Usefulness of Tc-99m ECD brain SPECT to evaluate the effects of methylprednisolone pulse therapy in lupus erythematosus with brain involvement: a preliminary report.

Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in systemic lupus erythematosus (SLE) with brain manifestations. However, its efficacy in SLE patients remains uncertain and needs to be objectively evaluated. In this study, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect regional cerebral blood flow (rCBF) in SLE patients with normal brain magnetic resonance imaging (MRI) findings. Twelve female SLE patients with neuropsychiatric symptoms were enrolled in this study. All patients had normal brain MRI and abnormal Tc-99m ECD brain SPECT findings. The Tc-99m ECD brain SPECT studies were performed 2 weeks after MPT. Pre- and post-MPT serum levels of anticardiolipin antibodies (ACA) and antiribosomal P antibodies (anti-P) were also measured. Before MPT, four patients had positive ACA and seven had positive anti-P. After MPT, all 12 patients demonstrated negative serologic findings and no neuropsychiatric symptoms. After MPT, ten patients showed complete recovery and two showed partial recovery of rCBF in the follow-up Tc-99m ECD brain SPECT images. This imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by the determination of rCBF changes.

Adult↗
PubMed2003

Usefulness of 99mTc ethyl cysteinate dimer brain SPECT to detect abnormal regional cerebral blood flow in patients with acute carbon monoxide poisoning.

99mTc ethyl cysteinate dimer (99mTc-ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in patients with acute carbon monoxide (CO) poisoning. Ten patients with acute CO poisoning and no past histories of psychoneurological disorders were enrolled in this study. After oxygen treatment, all of the 10 patients were investigated using 99mTc-ECD brain SPECT and brain computed tomography (CT) scan. Brain CT scan findings were normal in all of the 10 patients. 99mTc-ECD brain SPECT showed the hypoperfusion lesions of the basal ganglia and brain cortex in five and seven patients, respectively. Only three of the 10 patients had normal 99mTc-ECD brain SPECT findings. This study suggests that, in comparison with brain CT scan, 99mTc-ECD brain SPECT is a better tool for the early detection of hypoperfusion brain lesions in acute CO poisoning in patients with normal brain CT findings.

Adolescent↗
PubMed2002

Objective evidence of abnormal regional cerebral blood flow in patients with systemic lupus erythematosus on Tc-99m ECD brain SPECT.

Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in 78 SLE patients with neuropsychiatric manifestations. These patients were separated into two subgroups: group 1 including 48 cases with definite neuropsychiatric symptoms/signs and group 2 with 30 cases having no neuropsychiatric symptoms/signs. Tc-99m ECD brain SPECT demonstrated hypoperfusion brain lesions in 90% and 20% of patients in groups 1 and 2, respectively. In both groups, parietal lobe and cerebellum are the most and least common areas with hypoperfusion lesions, respectively. This study suggests that Tc-99m ECD brain SPECT may provide objective information for detection of hypoperfusion brain lesions in SLE patients.

Adult↗
PubMed2002

Abnormal 201Tl myocardial single photon emission computed tomography in energetic male patients with myocardial bridge.

Myocardial bridge is a relatively benign condition where a major coronary artery is bridged by a band of muscle and narrows during systole, particularly during rapid heart rates. Its clinical presentation and electrocardiogram (ECG) changes overlap with that of coronary artery disease. 201Tl myocardial perfusion imaging is thus frequently prescribed for further evaluation. This retrospective study was carried out to determine the 201Tl image patterns in patients with myocardial bridge. A total of 17 male patients (aged from 30 to 63 years) who had a positive exercise ECG and angiographic evidence of myocardial bridge in the mid-third of the left anterior descending coronary artery were recruited. Most of them were robust and received routine physical check-ups. They had no known heart disease or medication that affected cardiac function. The patients' clinical presentations, echocardiograph and exercise ECG findings were analysed. 201Tl single photon emission computed tomography (SPECT) was performed by intravenous injection of 201Tl (111 MBq) immediately following stress (treadmill or dipyridamole induced) and 4 h after stress, using a fixed, right angle camera equipped with a low energy, general purpose collimator. The images were interpreted independently by two experienced nuclear medicine physicians. Nine of the 17 patients had anterior chest pain during exercise. All patients had an abnormal ECG during exercise, including ST-T wave depression in leads II, III and aVF, and v4-6. Except for eight patients revealing reversible perfusion defect (R), 16 of the 17 patients also exhibited a partial reversible perfusion defect (PR) or a significant reverse redistribution (RR) scan pattern in the anterior or inferior walls of the left ventricle. Myocardial bridge should be taken into consideration in energetic male patients who had abnormal exercise ECGs and the corresponding patterns of Tl SPECT abnormalities including R, PR and RR.

Adult↗
PubMed2001

Biaryl-based macrocyclic and polymeric chiral (salophen)Ni(II) complexes: synthesis and spectroscopic study.

Polymeric/oligomeric and macrocyclic (salophen)Ni(II) complexes have been synthesized starting from both an achiral biphenol dialdehyde and an optically active BINOL dialdehyde. It was found that these polysalophens contain nonplanar coordination of Ni(II) units that are paramagnetic. This is different from the previously reported (salophen)Ni(II) complexes which are square planar and diamagnetic. The nonplanar (salophen)Ni(II) units make the new polymeric Ni(II) complexes different from the helical structure proposed for chiral biaryl-based polymers containing square-planar (salophen)Ni(II) units. The copolymerization of the chiral binaphthyl monomer with the achiral biphenyl monomer demonstrates that the chirality of the binaphthyl unit is not propagated along the biphenyl polymer chain.

Journal Article↗
PubMed2001

The role of dopamine transporter imaging agent [99mTc]TRODAT-1 in hemi-parkinsonism rat brain.

This study aims to investigate the relationship between the determination of dopamine level by high performance liquid chromatography (HPLC) with electrochemical detection (ECD) and the detection of dopamine transporter (DAT) counts using autoradiography with DAT image agent [99mTc]TRODAT-1. For striatal lesions, pretreatment of 6-hydroxydopamine (6-OHDA) in the medial forebrain bundle shows that autoradiogaphic labeling of striatum region is reduced to near-background level. Using HPLC with ECD, unilateral 6-OHDA treatment is associated with significant (p < 0. 0002) reductions of dopamine levels. For the striatum of the 6-OHDA-lesioned side, dopamine content and DAT counts are reduced to 97% and 90%, respectively. Thus, our observation indicates a potential of using [99mTc]TRODAT-1 for the evaluation of animal DAT.

Animals↗
PubMed2001

Iliofemoral vein thrombosis and pulmonary embolism associated with a transient ischemic attack in a patient with antiphospholipid syndrome.

Several clinical conditions, such as deep vein thrombosis, cerebral infarct, pulmonary infarct, skin ulcers, renal failure, and habitual abortion, are thought to be associated with the antiphospholipid syndrome. The authors describe a 32-year-old woman who had characteristics of the antiphospholipid syndrome including increased immunoglobulin G-cardiolipin antibody titers, iliofemoral vein thrombosis, pulmonary embolism, headache, visual disturbances, and habitual abortion. During hospitalization, she suddenly experienced right-sided weakness. A Tc-99m HMPAO brain scan showed the probability of a transient ischemic attack in the left frontotemporal cortex.

Adult↗
PubMed2001

3,3'-Diiodothyronine sulfate excretion in maternal urine reflects fetal thyroid function in sheep.

We have shown that there is significant fetal-to-maternal transfer of sulfated metabolites of thyroid hormone after fetal infusion of a pharmacologic amount of 3,3',5-triiodothyronine (T(3)) or sulfated T(3) in late pregnancy in sheep (Am J Physiol 277:E915, 1999). The transferred iodothyronine sulfoconjugate, i.e. 3,3'-diiodothyronine sulfate (T(2)S), of fetal origin appears in maternal sheep urine. The present study was carried out to assess the contribution of T(2)S of fetal origin to the urinary pool in ewes. Eighteen date-bred ewes (mean gestational age of 115 d) and their twin fetuses were divided into four groups. In group I (control, n = 5), both ewes (M) and their fetuses (F) were sham operated for thyroidectomy (Tx). In group II, the ewes (MTx, n = 4) and, in group III, the fetuses (FTx, n = 4) were subjected to Tx. In group IV (MTx.FTx, n = 5), both the ewe and fetus had Tx. After 10-12 d, fetal and/or maternal hypothyroidism were confirmed by serum thyroxine (<15 nmol/L) measurements. In addition, we infused radioactive T(3) without disturbing the T(3) pool in three singleton near-term fetuses and assessed the amount of radioactive iodothyronine that appeared in maternal urine (MU). After infusing [(125)I-3'],3,5-T(3) via fetal vein to the near-term normal fetuses, radioactive T(2)S was identified as the major metabolite in MU by HPLC and T(2)S-specific antibody. MU T(2)S excretion (pmol/mmol creatinine) was significantly reduced by FTx and MTx.FTx but not by MTx. In addition, positive correlations (p < 0.01) were found between MU T(2)S excretion and fetal serum thyroxine and T(3) concentrations but not with maternal serum thyroxine or T(3) levels. T(2)S of fetal origin contributes significantly to the MU pool.

Animals↗
PubMed2001

Evaluation of early-stage Parkinson's disease with 99mTc-TRODAT-1 imaging.

UNLABELLED: Parkinson's disease is a progressive neurodegenerative disorder characterized by a selective loss of dopamine in the striatum. Problems remain in the accurate diagnosis of Parkinson's disease. A 99mTc-labeled tropane derivative that binds to dopamine transporter with high selectivity is [2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl](2-mercaptoethyl)amino]ethyl]amino]ethanethiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)] (TRODAT-1). The purpose of this study was to investigate the potential usefulness of 99mTc-TRODAT-1 imaging in the evaluation of patients with early-stage Parkinson's disease. METHODS: Thirty-four patients with early-stage idiopathic Parkinson's disease were recruited. For all patients, the Parkinson's disease was stage 2 or less as assessed by the Hoehn and Yahr scale. Seventeen age-matched healthy volunteers (8 men, 9 women) served as controls. 99mTc-TRODAT-1 was prepared from a lyophilized kit. Brain SPECT imaging was performed between 165 and 195 min after injection, using a double-head camera equipped with fanbeam collimators. Specific uptake in the striatum and its subregions, including the putamen and caudate nucleus, was calculated and compared with that of the other sides and of healthy volunteers. RESULTS: A continuous reduction in specific striatal uptake of 99mTc-TRODAT-1 with increasing disease severity was found in Parkinson's disease patients (control vs. stage I vs. stage II, 1.98 vs. 1.62 vs. 1.22, respectively, P < 0.01). The changes were magnified by measurement of specific putaminal uptake (control vs. stage I vs. stage II, 1.81 vs. 1.27 vs. 0.94, respectively, P < 0.01). The mean values of specific putaminal uptake contralateral to the more affected limbs were significantly decreased compared with the ipsilateral sides in both stage I and stage II groups (1.02 vs. 1.49 for stage I and 0.73 vs. 1.14 for stage II, P < 0.01). Moreover, a significant loss of putaminal uptake ipsilateral to the symptoms was found in the stage I group compared with the healthy volunteers (1.49 vs. 1.81, P < 0.01). The difference became greater when the posterior putaminal uptakes were compared. No remarkable adverse reactions were found in either healthy volunteers or Parkinson's disease patients during or after imaging. CONCLUSION: For clinical practice, 99mTc-TRODAT-1 may serve as a useful imaging agent for the early detection of Parkinson's disease.

Aged↗
PubMed2000

The role of lung scintigraphy in the diagnosis of nephrotic syndrome with pulmonary embolism.

PURPOSE: Patients with nephrotic syndrome (NS) have an increased tendency to develop thrombosis and even to progress to pulmonary embolism (PE). This study was performed to determine the incidence of PE in NS with severe hypoalbuminemia and to investigate the possible role of ventilation-perfusion (V/Q) lung scans to evaluate these patients. METHODS: Eighty-nine patients with NS (serum albumin concentration < 2 g/dl) and risk factors for PE were studied. In all patients, the probability that PE would develop was assessed based on the results of V/Q lung scans (Xe-133 for ventilation and Tc-99m MAA for perfusion imaging). The lung scans were judged using the modified Prospective Investigation of Pulmonary Embolism Diagnosis criteria. In 25 (28%) patients whose lung scans showed an intermediate or low probability, but for whom there was a strong clinical indication of PE, pulmonary angiography was performed. The patients' clinical symptoms and signs on initial examination were observed. Additional examinations included electrocardiograms, chest radiography, and hematochemical tests such as albumin, blood urea nitrogen, creatinine, cholesterol, triglycerides, fibrinogen, antithrombin III, prothrombin time, and activated partial thromboplastin time. RESULTS: Based on the findings of lung scans, 19 (21%) of the patients were categorized as having a high probability of PE. However, pulmonary angiography found that 10 (11%) other patients had PE despite having lung scan findings categorized as intermediate or low probability of PE. Except for plasma fibrinogen and antithrombin III levels, neither the clinical symptoms and signs, electrocardiogram findings, chest radiograph results, nor values of hematochemical testing were consistent with the occurrence of PE in these 29 patients. CONCLUSION: The results of this study suggest that PE is not a rare complication in patients with NS, and is usually clinically silent. In this series, the occurrence of PE did not appear to be always correlated with the clinical or hematochemical severity of NS, except for the association with elevated levels of fibrinogen and antithrombin III. When treating the clinical symptoms of patients with NS, physicians should be alert to the possible complication of PE. Serial V/Q lung scans may provide valuable clues in the evaluation of these patients.

Angiography↗
PubMed2000

The effect of fasting on the pulse spectrum.

Nutrition is the major source of bioenergy. The present study investigated the physiological response to fasting by analyzing the effect of fasting on the pulse spectrum of the radial artery. Sixteen subjects were allowed to take only mineral water for 24 hours, and the pulse was measured at intervals during fasting and after eating resumed. Data were analyzed using one-way analysis of variance (ANOVA) with Scheffe's test for pairwise comparisons. The results indicate the second harmonic of the radial pulse increased and the sixth harmonic decreased significantly after 24 hours of fasting. The proportions of the second harmonic then decreased significantly and those of the sixth harmonic increased significantly 12 hours after eating resumed. These findings suggest that a rhythm exists in physiological changes and the distribution of bioenergy, which ensures that the overall heart load will remain unchanged during the fasting and re-feeding periods, maintaining a stable overall balance in body function.

Adult↗
PubMed2000

Iodothyronine sulfotransferase activity in rat uterus during gestation.

In developing mammals, we and others demonstrated that sulfation is an important pathway in the metabolism of thyroid hormone, and there is significant fetal-maternal transfer of sulfated iodothyronine. In the present study, we characterized a novel iodothyronine sulfotransferase (IST) in pregnant rat uterus. (125)I-labeled 3,3'-diiodothyronine (T(2)), T(3), rT(3), and T(4) were used as substrates with unlabeled 3'-phosphoadenosine-5'-phosphosulfate (PAPS) as the sulfate donor. Sulfated iodothyronine products were separated by Sephadex LH-20 column and further identified on reverse phase HPLC. We measured IST activity in pregnant rat uterus by incubating 1 microM substrate, 50 microM PAPS, and 50 microg cytosol protein, pH 7.2, 30 min at 37 degrees C. The results show that the substrate preference of the uterine IST activity is: T(2 )> rT(3 )> T(3)> T(4); the pH optimum is 6.0 for T(2). The K(m) and V:(max) (for gestational day 21 uterus) for T(2) are 0.62 microM and 3466 pmol/mg protein/h, respectively; for PAPS the values are 2.6 microM and 1523 pmol/mg protein/h, respectively. During pregnancy, the total activities exhibit a U-shaped curve with minimum activity at day 13 of gestation; while a thermostable activity increases significantly near term. In summary, there is significant uterine IST that varies during pregnancy. The role of this uterine sulfotransferase activities in regulating the bioavailability of thyroid hormone in the developing fetus remains to be elucidated.

Animals↗
PubMed2000

Aortoduodenal fistula presenting as acute massive gastrointestinal bleeding and recurrent syncope: case report.

Aortoenteric fistula is a rare condition that may cause death in patients due to gastrointestinal bleeding. The duodenum is the most frequently involved site, at 78.5% of 191 cases by Nagy and Marshall's meta-analysis. It is characterized by the clinical triad of abdominal pain, gastrointestinal bleeding, and an abdominal mass. Abdominal computed tomography is the most useful tool in detecting an aortoenteric fistula. To prevent a high mortality rate, early diagnosis is necessary. Exploratory laparotomy is required for patients who are highly suspected of having an aortoduodenal fistula. Herein, we report a 60-year-old man who suffered from acute gastrointestinal bleeding, recurrent syncope, and impending shock. Abdominal computed tomography revealed a 6 cm longitudinal aneurysm in the infrarenal aorta. Emergency laparotomy was performed and revealed an aortoduodenal fistula in the fourth portion of the duodenum causing acute duodenal bleeding. The patient survived and has undergone 2 years worth of regular follow-up in our outpatient department.

Aortic Diseases↗