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W Y Lin

Publications and source records attributed to W Y Lin.

At least 91 records · Page 5Linked to original sources
PubMed1998

Influence of age and gender on quantitative sacroiliac joint scintigraphy.

UNLABELLED: The value of quantitative sacroiliac joint scintigraphy for detecting sacroiliitis is controversial. Age and gender may contribute to this discordance. In previous reports, the number of control groups has been small and might not exactly reflect the change of sacroiliac/sacral (SI/S) ratios related to different age. In addition, the selection of control subjects was not strict. In most studies, care was not taken to ensure that control subjects did not have a history of back pain or any other relevant conditions. In addition, there was no requirement for a normal radiograph as a condition of inclusion. The aim of our study was to evaluate the consequent changes in SI/S ratios, according to age (in 10-yr intervals) and gender. METHODS: Over a period of 5 yr, 413 control subjects without a history of back pain, scoliosis, kyphosis, joint pain, arthritis, lesions within the pelvis, chemotherapy or systemic disease such as diabetes or systemic lupus erythematosus were included in this study. A posterior planar film of the pelvis was obtained to calculate SI/S ratio 3 hr after injection of 740 MBq 99mTc-methylenediphosphonate. Our data showed that: (a) the change in SI/S ratios related to age was significant in both females and males; (b) the SI/S ratios were higher in males younger than 30 yr and higher in men in the 41-50-yr age group and in females in other groups; (c) the SI/S ratios declined steadily with increasing age in females, whereas there were two plateaus in men aged 21-40 yr and 41-70 yr; (d) there were significant differences of SI/S ratios between the genders in certain age groups; and (e) no differences were found between left SI/S ratios and right SI/S ratios. CONCLUSION: The influence of age and gender on SI/S ratios are substantial, and it is essential for each department to establish its own values for SI/S ratios based on gender and age (in 10-yr intervals).

Adolescent↗
PubMed1998

Geographic variation in viral load among hepatitis B carriers with differing risks of hepatocellular carcinoma.

The risk of hepatocellular carcinoma (HCC) varies significantly among hepatitis B virus (HBV) carriers from different geographic regions. We compared serological markers of HBV infection in adult male carriers from Haimen City, China and Senegal, West Africa, where the prevalence of chronic infection is similar. HCC mortality among HBV carriers is much higher in Haimen City than it is in Senegal (age-standardized rate, 878 versus 68 per l0(5) person-years). A dramatic difference was observed when HBV DNA levels in serum were assessed among carriers by Southern blot. In the Senegalese group (n = 289), 14.5% were HBV DNA positive by Southern blot in their 20s, and this percentage declined in each subsequent decade of age to 3.3, 2.9, and 0% thereafter. In the Chinese group (n = 285), a higher prevalence of HBV DNA positivity and a less consistent reduction were seen; 29.4% were positive in their 20s, and 30.2, 23.6, and 20.6%, respectively, were positive in each subsequent decade of age. Among 102 male Asian-American HBV carriers, the prevalence of HBV DNA positivity was intermediate between the Chinese and Senegalese populations (36.8, 10.7, 3.0, and 4.6% in each subsequent decade of age). Viral titers were similar among those who were HBV DNA positive in all three populations [median value, 10(7) virions/ml (range, 10(6)-10(9) virions/ml)]. The presence of HBV DNA in serum was positively associated with serum glutathione S-transferase, a marker of liver damage. These findings suggest that the more prolonged maintenance of productive virus infection in the Chinese carriers compared with the Senegalese carriers may explain their higher risk of HCC. This profound difference in the natural history of chronic infection may be due to earlier age of infection in China or to as yet unknown environmental or genetic factors.

Adult↗
PubMed1998

Intratumoral injection of rhenium-188 microspheres into an animal model of hepatoma.

UNLABELLED: Intratumoral injection of 90Y microspheres is a potential alternative in the treatment of primary liver tumor. However, complicated preparation and lack of a gamma ray for imaging are the disadvantages of 90Y. In this study, we used 188Re, a generator-produced radioisotope with 155-keV gamma ray emission, to label microspheres. After intratumoral injection of 188Re microspheres into rats with hepatoma, biodistributions and survival times were analyzed. METHODS: Twelve male rats with hepatoma were killed at 1, 24 and 48 hr (4 rats at each time point) after intratumoral injection of approximately 7.4 MBq 188Re microspheres. Samples of various organs were obtained and used to calculate the tissue concentrations. In addition, 30 male rats bearing hepatoma were divided into two groups (15 rats in each group) to evaluate survival time. Group 1 received intratumoral injection of 37 MBq 188Re microspheres, whereas Group 2 served as the control group and received an intratumoral injection of 0.1 ml normal saline only. Survival time was calculated from the day of injection to 2 mo after treatment. RESULTS: Radioactivity in the tumor was very high throughout. Biological half-time was 170.8 hr. Radioactivity in the lung was 1.78% injected dose (i.d.)/g at 1 hr but declined rapidly over time. The concentration in the urine was approximately 6.14% i.d./ml after the first hour and rapidly declined thereafter. The concentrations of radioactivity in other organs, such as normal liver, muscle, spleen, bone, testis and whole blood, were quite low throughout the study. Twelve of 15 (80%) of rats survived over 60 days after intratumoral injection of 188Re microspheres, whereas only 4 of 15 (26.7%) survived more than 60 days after injection of normal saline only. The difference between the groups was significant (p < 0.05). CONCLUSION: Rhenium-188 offers cost-effectiveness, on-site availability, short half-life, energetic beta particle, emission of gamma photons for imaging, easy preparation, easy clinical administration and apparent lack of radiation leakage from the treated tumor. Direct intratumoral injection of 188Re microspheres is extremely attractive as a clinical therapeutic alternative in hepatoma patients.

Animals↗
PubMed1998

Gallium-67 scintigraphy to predict response to therapy in active lupus nephritis.

UNLABELLED: Gallium-67-citrate has been used to detect inflammation for decades, and 67Ga uptake usually indicates an active, potentially curable lesion. In this study, we determined the value of 67Ga renal scintigraphy for predicting response to therapy in patients with lupus nephritis. METHODS: Forty-seven patients with lupus nephritis and abnormal serum creatinine or elevated 24-hr urine protein were enrolled. Delayed 48-hr 67Ga imaging was performed to evaluate 67Ga uptake by the kidneys. Serum creatinine and 24-hr urine protein values were obtained at the beginning of this study and after 1 yr of treatment. Serum creatinine was considered abnormal at levels greater than or equal to 1.4 mg/dl and 24-hr urine protein at levels greater than or equal to 1.0 g/day. When the value of serum creatinine or 24-hr urine protein obtained 1 yr after treatment was in the normal range or was 50% of the initial abnormal value, the patient was considered to have good response to treatment. RESULTS: Gallium-67 renal scan showed good correlation with the response to therapy in patients with lupus nephritis. In the negative 67Ga scan group, no significant changes in laboratory data were noted between onset of this study and after 1 yr of therapy. In the positive 67Ga scan group, there were significant decreases in serum creatinine and 24-hr urine protein levels 1 yr after treatment, especially in 24-hr urine protein, with p values of 0.019 and 0.0007 respectively, by Student's t-test for dependent samples. Moreover, 11.5% of patients with a negative 67Ga scan had a good response to treatment, whereas 71.4% of patients with a positive 67Ga scan had a good response to treatment. CONCLUSION: We suggest that 67Ga renal scan is a valuable predictor of response to therapy in patients with lupus nephritis.

Adult↗
PubMed1997

Rhenium-188 hydroxyethylidene diphosphonate: a new generator-produced radiotherapeutic drug of potential value for the treatment of bone metastases.

The search for an ideal radioisotope for systemic radiotherapy continues. As a generator-produced radioisotope emitting both beta and gamma rays and having a short physical half-life of 16.9 h, rhenium-188 is a very good potential candidate for systemic radiotherapy. In this study, we labeled hydroxyethylidene diphosphonate (HEDP) with 188Re and analyzed the biodistribution and bone uptake following intravenous injection in rats to assess its potential for clinical use. The rats were injected with approximately 14.8 MBq (0.4 mCi) 188Re-HEDP in a volume of 0.1 ml intravenously and then sacrificed at 1 h, 24 h, or 48 h (four rats at each time). Samples (about 0.1 g) of lung, liver, kidney, spleen, testis, muscle, stool, and bone (thoracic vertebra) were taken and weighed carefully. In addition, a 1-ml sample of blood was drawn from the heart and 1 ml of urine was taken from the urinary bladder immediately after killing. Tissue concentrations were calculated and expressed as percent injected dose per gram or per milliliter (% ID/g or ml). Bone lesions were created in the right tibial bone in three rabbits to calculate the lesion to normal uptake ratio (L/N ratio). The biodistribution data showed that the radioactivity in the bone tissue was as high as 1.877% ID/g at 1 h and that it climbed to 2.017% ID/g at 4 h. The activity level in the kidney was highest at 1 h but declined rapidly throughout the study. The radioactivities in the lung, liver, muscle, spleen, testis, blood, and stool were all lower than 0.3% ID/g at 1 h and also declined rapidly. The biological half-life in bone was the longest (60.86 h). In contrast, the biological half-lives in muscle and blood were short (2.99 h and 6.21 h respectively). The concentrations of radioactivity in muscle, spleen, testis, and stool were quite low throughout the study. Most of the radiotracer was excreted by the urinary system. The L/N ratio was 4.23+/-0.21 in rabbits injected with 188Re-HEDP and 4.25+/-0.23 in those injected with technetium-99m methylene diphosphonate. In conclusion, we would suggest that 188Re-HEDP is a very good potential candidate for the treatment of bone metastases because of the following characteristics: (1) it is generator produced; (2) it has a short half-life; (3) it emits gamma rays suitable for imaging; (4) there is highly selective uptake in the skeletal system and bone lesions; and (5) it has a low non-target uptake and rapid clearance in nonosseous tissue.

Animals↗
PubMed1997

Comparison technetium of Tc-99m disofenin cholescintigraphy with ultrasonography in the differentiation of biliary atresia from other forms of neonatal jaundice.

Technetium Tc-99m disofenin cholescintigraphy (CS) and ultrasonography (US) are two major clinical methods used in differentiating biliary atresia (BA) from neonatal jaundice. To compare the diagnostic utility of these two modalities, 66 patients with neonatal cholestasis (15 BA, 3 choledochal cyst (CC), 32 neonatal hepatitis, 13 prolonged jaundice, 2 total parenteral nutrition, and 1 sepsis) underwent Tc-99m disofenin CS and US. The diagnostic sensitivity, specificity, and accuracy of CS in differentiating BA from other forms of neonatal jaundice was 100%, 87.5%, and 90.5%, respectively, and for US 86.7%, 77.1%, and 79.4%, respectively. Tc-99m disofenin CS after premedication with phenobarbital and cholestyramine is a convenient and reliable method of differentiating BA from neonatal hepatitis, with a diagnostic accuracy superior to that of US. However, US is the initial imaging procedure of choice in patients presenting with jaundice to rule out anatomic anomalies such as CC.

Biliary Atresia↗
PubMed1997

Detection of acute inhalation injury in fire victims by means of technetium-99m DTPA radioaerosol inhalation lung scintigraphy.

Mortality and morbidity in fire victims are largely a function of injury due to heat and smoke. While the degree and area of burn together constitute a reliable numerical measure of cutaneous injury due to heat, as yet no satisfactory measure of inhalation injury has been developed. In this study, we employed technetium-99m diethylene triamine penta-acetic acid (DTPA) radioaerosol lung scintigraphy (inhalation scan) to evaluate acute inhalation injury in fire victims. Ten normal controls and 17 survivors from a fire accident were enrolled in the study. All patients suffered from respiratory symptoms (dyspnoea and/or cough with sputum). 99mTc-DTPA aerosol inhalation lung scintigraphy was performed in all subjects, using a commercial lung aerosol delivery unit. The degree of lung damage was presented as the clearance rate (k; %/min) calculated from the time-activity curve over the right lungs. In addition, the distribution pattern of the radioactivity in the lungs was evaluated and classified into two groups: homogeneous distribution and inhomogeneous distribution. A plain chest radiograph (CxR) and pulmonary function test (PFT) were performed in the same group of patients. The results showed that 6/17 (35.3%) patients had inhomogeneous distribution of radioactivity in their inhalation scans, and 11/17 (64.7%) had homogeneous scans. Five of the six patients with inhomogeneous scans were admitted for further management, and all patients with homogeneous scans were discharged from the emergency department and needed no further intensive care. The clearance rates of the right lung were 0.73%+/-0.13%/min for normal controls and 1.54%+/-0.58%/min for fire victims. The difference was significant, with a P value of less than 0.01. Using a cut-off value of 0.9%/min (all normal subjects were below 0. 9%/min), 14 (82.4%) patients had abnormal clearance rates of 99mTc-DTPA from the lung. In contrast, only three (17.6%) patients had abnormal CxR and three (17.6%) had abnormal PFTs. We conclude that (1) conventional CxR and PFT are not good modalities for evaluating inhalation injury in fire victims because of their low sensitivity, and (2) 99mTc-DTPA radioaerosol inhalation scintigraphy can provide an objective evaluation of inhalation injury during a fire accident and may be useful in therapeutic decision-making and disease monitoring.

Administration, Inhalation↗
PubMed1997

Temporal selectivity for complex signals by single neurons in the torus semicircularis of Pleurodema thaul (Amphibia:Leptodactylidae).

Responses of auditory neurons in the torus semicircularis (TS) of Pleurodema thaul, a leptodactylid from Chile, to synthetic stimuli having diverse temporal patterns and to digitized advertisement calls of P. thaul and three sympatric species, were recorded to investigate their temporal response selectivities. The advertisement call of this species consists of a long sequence of sound pulses (a pulse-amplitude-modulated, or PAM, signal) having a dominant frequency of about 2000 Hz. Each of the sound pulses contains intra-pulse sinusoidal-amplitude-modulations (SAMs). Synthetic stimuli consisted of six series in which the following acoustic parameters were systematically modified, one at a time: PAM rate, pulse duration, number of pulses, and intra-pulse SAM rate. The carrier frequency of these stimuli was set at the characteristic frequency (CF) of the isolated units (n = 47). Response patterns of TS units to synthetic call variants reveal different degrees of selectivities for each of the temporal variables, with populations of neurons responding maximally to specific values found in the advertisement call of this species. These selectivities are mainly shaped by neuronal responsiveness to the overall sound energy of the stimulus and by the inability of neurons to discharge to short inter-pulse gaps.

Acoustic Stimulation↗
PubMed1997

Kinetic studies of the inhibitory effects of propeptides subtilisin BPN' and Carlsberg to bacterial serine proteases.

The propeptides of bacterial subtilisin BPN' and Carlsberg were synthesized to investigate their inhibitory function on the enzymes. Kinetically, pro-BPN' inhibits the proteolytic activities of subtilisin BPN' and Carlsberg separately in a slow binding mode. Pro-Carlsberg behaves as a typical rapid equilibrium competitive inhibitor for these two proteases. Functionally, pro-Carlsberg inhibits the subtilisins with moderate selectivity. The inhibition constant Ki of pro-BPN' to subtilisin BPN' is 5.0 nM, and 6.1 nM to subtilisin Carlsberg. The on-rate of pro-BPN' to subtilisin BPN' is 5.8 x 10(5) M(-1)s(-1), and the off-rate 2.9 x 10(-3) s(-1). Similarly, the on-rate of pro-BPN' to subtilisin Carlsberg is 2.2 x 10(5) M(-1)s(-1), and the off-rate 1.3 x 10(-3) s(-1). On the other hand, the Ki of pro-Carlsberg to subtilisin BPN' gives 1.3 x 10(2) nM, and 88 nM to subtilisin Carlsberg. Based on the key features of the interactions between pro-BPN' and subtilisin from X-ray crystallographic results (Gallagher et al., 1995), the correlation between the sequence of subtilisin propeptides and their inhibition abilities on the proteases are compared and discussed.

Amino Acid Sequence↗
PubMed1997

99Tcm-HMPAO-labelled white blood cell scans to detect acute appendicitis in older patients with an atypical clinical presentation.

Forty-nine patients (age > 50 years) with an acute abdomen and suspected appendicitis, but with atypical findings, were included in the study. After the intravenous injection of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) labelled white blood cells (WBCs), serial anterior images of the abdomen and pelvis were obtained after 30, 60, 120 and 240 min. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen equal to or greater than bone marrow activity was considered positive. Twenty-five patients had positive WBC scans, all of whom underwent laparotomy. Twenty-three of these patients were shown to have appendicitis; the other 2 did not. The other 24 patients had a negative WBC scan, 2 of whom underwent laparotomy and were shown to have appendicitis; the other 22 patients did not undergo surgery and showed no evidence of appendicitis during follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values of WBC scans for diagnosing appendicitis were as follows: 92.0%, 91.7%, 91.8%, 92.0% and 91.7% respectively. In conclusion, 99Tcm-HMPAO-labelled WBC scans provide a rapid and highly accurate method for diagnosing appendicitis in older patients with equivocal clinical findings.

Abdomen, Acute↗
PubMed1997

Technetium-99m-HMPAO brain SPECT in systemic lupus erythematosus with CNS involvement.

UNLABELLED: Functional brain SPECT is playing an increasingly important role in evaluating CNS conditions in patients with systemic lupus erythematosus (SLE). However, SPECT findings varied in different studies because of their small population. Furthermore, earlier researchers, being restricted by the resolution of the camera, might not have been able to evaluate deep-seated nuclei such as the basal ganglia and thalamus. In this study, we describe the different patterns of SPECT findings in SLE patients with CNS involvement. METHODS: Seventy-two SLE patients (aged 14-67 yr; mean 33.2 yr) were divided into three groups: Group 1 with definite neuro-psychiatric disorder (including stroke, seizures and psychosis); Group 2 with minor neuropsychiatric disorders (headache, dizziness and recent memory impairment); and Group 3 without any neuropsychiatric symptoms or signs. Ninety minutes after injection of 1110 MBq 99mTc-HMPAO, brain SPECT was performed using a dual-head camera and fan-beam collimator. In addition, MRI and an electroencephalography (EEG) were also performed. RESULTS: SPECT findings were normal in 87% of the Group 3 patients and abnormal in all Group 1 patients; 84.6% of the Group 2 patients had abnormal SPECT findings. The parietal, frontal and temporal lobes were the most common areas of CNS involvement. Parietal lobes were involved in 95.6% of Group 1 patients and 80.7% in Group 2 patients. Frontal lobes were involved in 56.5% of Group 1 patients and 65.3% of Group 2 patients. Temporal lobes were involved in 56.5% of Group 1 patients and 46.1% of Group 2 patients. The basal ganglion was involved in about 30% of Group 1 patients and 11.5% of Group 2 patients, while the thalamus and cerebellum were less involved in neuropsychiatric SLE. MR images showed less sensitivity in the detection of CNS involvement than the SPECT and were normal in 27.3% of patients with definite neuropsychiatric disorders. The EEG and anticardiolipin antibody did not correlate well to the clinical diagnosis. CONCLUSION: HMPAO brain SPECT had the best correlation with the clinical diagnosis and may provide additional and objective information on SLE patients with potential CNS involvement.

Adolescent↗
PubMed1996

Effect of chaotropic denaturant on the binding of 1-anilino-8-naphthalene sulfonic acid to proteins.

1-Anilino-8-naphthalene sulfonic acid (ANS), a hydrophobic dye, is widely used to monitor conformational changes occurring in proteins during their folding/unfolding. Using cardiotoxin III (whose conformation remains unperturbed even in 6 M urea) from the Taiwan Cobra (Naja naja atra) venom, it is demonstrated that chaotropic denaturant such as urea directly competes with the interaction between ANS and the protein. The results presented in this report, in our opinion, has significant implication(s) in the area of protein folding, arising out of ANS binding experiments.

Anilino Naphthalenesulfonates↗
PubMed1996

Neuronal architecture of the dorsal nucleus (cochlear nucleus) of the frog, Rana pipiens pipiens.

The neuronal architecture of the dorsal nucleus of the Northern leopard frog (Rana pipiens pipiens), which is a homolog of the cochlear nucleus of mammals and birds, was investigated. Our study showed that the frog dorsal nucleus contains a number of morphologically distinct cell types that are discernible in terms of the cellular architecture as derived from Nissl-stained material and in terms of the dendritic profile as revealed by horseradish peroxidase-filled single neurons. These cell types are bushy cells, bipolar (or fusiform) cells, octopus cells, stellate cells, giant cells, radiate (or round) cells, and a variety of small cells. The different cell types occupy different regions of the nucleus. Therefore, our results suggest that the dorsal nucleus should no longer be considered to be a uniform nucleus containing a homogeneous population of neurons. Homologies of these cell types with those described in other vertebrate species, including mammals, are proposed.

Animals↗
PubMed1996

Biodistribution of rhenium-188 Lipiodol infused via the hepatic artery of rats with hepatic tumours.

The purpose of this study was to analyse the biodistribution of rhenium-188 Lipiodol in rats with hepatic tumours following intrahepatic arterial injection to assess the potential of 188Re-Lipiodol as a radiopharmaceutical for the treatment of hepatic tumours in humans. Twelve male rats with hepatic tumours were killed at 1h, 24h and 48h after injection of approximately 7.4MBq of 188Re-Lipiodol via the hepatic artery. Samples of various organs were obtained and counted to calculate the tissue concentration. Radioactivity in the hepatic tumours was very high throughout this study, with a biological half-life of 122.9h. Radioactivity in the normal liver tissue was also high, but was significantly lower than in the tumour. The biological half-life in the normal liver tissue was 31.7h. The ratio of tumour concentration to the normal liver tissue concentration was 5.15 at 1h and rose to 7.7 at 24h and 10.84 at 48h. The level of radioactivity in the lung was high at 1h, and declined rapidly over time. The level of radioactivity in the kidney was moderate throughout the study. The radiation concentrations in muscle, spleen, testis, bone and whole blood were insignificant. We conclude that 188Re-Lipiodol should be considered as a potential radiopharmaceutical for the intra-arterial treatment of hepatic tumours.

Animals↗
PubMed1996

Thermal denaturation of an all beta-sheet protein--identification of a stable partially structured intermediate at high temperature.

The thermal unfolding of an all beta-sheet protein, cardiotoxin analogue III, from the Taiwan Cobra (Naja naja atra) is studied at pH 2.0, 4.0 and 6.0. At pH 4.0, using circular dichroism and 1-anilino naphthalene-8-sulphonic acid (ANS) fluorescence binding studies, a stable partially structured intermediate is detected at 90 degrees C.

Anilino Naphthalenesulfonates↗