Search PubMed⌕ Search

Biomedical subjects

W Y Lin

Publications and source records attributed to W Y Lin.

At least 73 records · Page 4Linked to original sources
PubMed1999

Chemical constituents and biological activities of the fruit of Zanthoxylum integrifoliolum.

Through continuing studies on the chemical constituents and antiplatelet aggregation principles of the fruit of the Formosan Zanthoxylum integrifoliolum, four new compounds-including two new lignans, (+)-pinoresinol-di-3,3-dimethylallyl ether (1), and (+)-pinoresinol-3,3-dimethylallyl ether (2); zanthonitrile (3), and one new flavonoid, 3,5-diacetyltambulin (4)-and 18 known compounds were isolated from the CHCl3-soluble fraction. Their structures were elucidated on the basis of spectral data and chemical evidence. Among the isolates, including the previously reported isobutylamides, 13 compounds showed strong in vitro antiplatelet aggregation activity, with only (-)-tetrahydroberberine showing weak vasorelaxing effect in high potassium- or norepinephrine-induced contraction of rat aorta.

Animals↗
PubMed1999

Mandibular lengthening by distraction osteogenesis in children--a one-year follow-up study.

OBJECTIVE: The present study was undertaken to document whether mandibular length could be increased by distraction osteogenesis in children and what happens to the mandibular position 1 year after the distraction. METHODS: Five patients with hemifacial microsomia (four unilateral, one bilateral) had distraction osteogenesis performed to lengthen the mandible. All patients had cephalometric and panoramic radiographs obtained before and 3, 6, and 12 months after the distraction osteogenesis. RESULTS: The total mandibular length (Co-Gn) on the affected side was increased by 11.2 mm after the distraction and remained stable during a 1-year observation period. However, the increased mandibular length tended to move the chin downward (8 mm) more than forward (2 mm) during the same period. CONCLUSIONS: Distraction osteogensis can be used to lengthen the hypoplastic mandible. However, most of the increased mandibular length moved the chin downward more than forward.

Activator Appliances↗
PubMed1999

Bilateral coronoid process hyperplasia with limitation on mouth opening: case report.

Coronoid process hyperplasia with limitation of mouth opening is rare. The pathology is often ignored, but it can be easily detected using dental panoramic view of x-ray films. Definition of the coronoid process hyperplasia can be made by measuring the height of coronoid process and the ratio of coronoid/condyle height on lateral cephalometric x-ray film. Etiology of the coronoid process hyperplasia can be congenital or acquired. Differentiation of the diagnosis may be difficult. The congenital type occurs at early age with clinical manifestations. Proposed hypotheses for the formation of coronoid process hyperplasia include increased activity within the temporalis muscle from conditions such as functional stress, compression, and tension. For patients with coronoid process hyperplasia and restriction on mouth opening, conservative treatment should first be attempted. Surgical treatment is considered if conservative treatment fails. Coronoidectomy with early mobilization and aggressive physiotherapy corrects the problem. We present a patient with coronoid process hyperplasia with limitation of mouth opening who was successfully treated.

Abnormalities, Multiple↗
PubMed1999

Gallium-67 citrate scan in extrapulmonary tuberculosis.

AIM: Whole-body gallium scan was performed to evaluate the usefulness of gallium scan for detecting extrapulmonary tuberculosis (TB) lesions. METHODS: Thirty-seven patients with extrapulmonary TB were included in this study. Four patients were found to have two lesions. Totally, 41 lesions were identified, including 19 TB arthritis, 8 spinal TB, 5 TB meningitis, 3 TB lymphadenopathy, 2 TB pericarditis, 1 TB peritonitis, 1 intestinal TB, 1 skin TB and 1 renal TB. RESULTS: Of the 41 extrapulmonary TB lesions, gallium scan detected 32 lesions with a sensitivity of 78%. All the patients with TB meningitis showed negative gallium scan. When the five cases of TB meningitis were excluded, the detection sensitivity of gallium scan increased to 88.9% (32/36). CONCLUSION: Our data revealed that gallium scan is a convenient and useful method for evaluating extrapulmonary TB lesions other than TB meningitis. We suggest that gallium scan be included in the clinical routine for patients with suspected extrapulmonary TB.

Adult↗
PubMed1999

Midface distraction osteogenesis in cleft patients: a case report.

We present a case of midface distraction in a bilateral cleft lip and palate patient. The patient was a 10-year-old who underwent a high LeFort I osteotomy followed by placement of the Rigid External Distraction halo. Distraction was commenced on the fifth postoperative day at a rate of 1 to 1.5 mm per day until a total of 17 mm of maxillary advancement had been achieved. There were no complications and follow up was at 9 months post distraction. Results show that the patient had improved facial aesthetics and dental occlusion which was overcorrected to a Class III relationship. Velopharyngeal function was unaffected. Distraction osteogenesis of the midfacial skeleton in cleft patients offers the possibility to remodel not only the underlying bony skeleton but also all the soft tissues of the face and palate.

Child↗
PubMed1999

Pentavalent Tc-99m dimercaptosuccinic acid imaging of hepatocellular carcinoma.

Tc-99m (V)-dimercaptosuccinic acid (DMSA) has been used to image various kinds of tumors. However, from a review of the literature, it has never been applied to hepatocellular carcinoma (HCC). Low uptake of Tc-99m (V)-DMSA has been demonstrated in normal liver tissue, thus, Tc-99m (V)-DMSA may be useful for the detection of HCC. Nine male patients with focal nodular HCC were studied with sequential X-ray CT, Tc-99m (V)-DMSA and Tc-99m phytate liver scan. Our data showed that eight patients had increased uptake of Tc-99m (V) DMSA in HCC. Four cases demonstrated higher Tc-99m (V) DMSA uptake in HCC than in adjacent liver, and four cases demonstrated HCC uptake equal to liver uptake. One case showed no uptake of Tc-99m (V) DMSA in HCC. The detection sensitivity of Tc-99m (V)-DMSA was 88.9%. From our early results, Tc-99m (V)-DMSA is a readily available tumor imaging agent that appears to accumulate in HCC.

Adult↗
PubMed1998

Antigen-specific cytolysis by neutrophils and NK cells expressing chimeric immune receptors bearing zeta or gamma signaling domains.

TCR- and IgG-binding Fc receptors (Fc gamma R) mediate a variety of critical biologic activities including cytolysis via the structurally related zeta- and gamma-chains. In previous studies, we have described chimeric immune receptors (CIR) in which the ligand-binding domain of a heterologous receptor or Ab is fused directly to the cytoplasmic domain of the TCR zeta-chain. Such zeta-CIRs efficiently trigger cytotoxic function of both T and NK cells in a target-specific manner. In this report, we compared the ability of both zeta- and gamma-CIRs to activate the cytolytic function of two distinct classes of Fc gamma R-bearing effectors, NK cells and neutrophils. Mature neutrophils expressing zeta- and gamma-CIR were generated in vivo from murine hemopoietic stem cells following transplantation of syngeneic mice with retrovirally transduced bone marrow or in vitro from transduced human CD34+ progenitors following differentiation. Both zeta- and gamma-based CIRs were capable of activating target-specific cytolysis by both NK cells and neutrophils, although the zeta-CIR was consistently more efficient. The experimental approach described is a powerful one with which to study the role of nonlymphoid effector cells in the host immune system and permits the rational design of immunotherapeutic strategies that rely on harnessing multiple immune cell functions via CIR-modified hemopoietic stem cells or progenitors.

Adult↗
PubMed1998

Events in the kinetic folding pathway of a small, all beta-sheet protein.

The folding of cardiotoxin analogue III (CTX III), a small (60 amino acids), all beta-sheet protein from the venom of the Taiwan Cobra (Naja naja atra) is here investigated. The folding kinetics is monitored by using a variety of techniques such as NMR, fluorescence, and circular dichroism spectroscopy. The folding of the protein is complete within a time scale of 200 ms. The earliest detectable event in the folding pathway of CTX III is the formation of a hydrophobic cluster, which possess strong affinity to bind to nonpolar dye such as 1-anilino-8-napthalene-sulfonic acid. Quenched-flow deuterium-hydrogen exchange experiments indicate that the segment spanning residues 51-55 along with Lys23, Ile39, Val49, Tyr51 and Val52 could constitute the "hydrophobic cluster." Folding kinetics of CTX III based on the amide-protection data reveals that the triple-stranded, antiparallel beta-sheet segment, which is located in the central core of the molecule, appears to fold faster than the double-stranded beta-sheet segment.

Amides↗
PubMed1998

A study of a new tumour marker, CYFRA 21-1, in squamous cell carcinoma of the head and neck, and comparison with squamous cell carcinoma antigen.

CYFRA 21-1 (CYFRA) is a newly developed tumour marker which is useful in evaluating large cell lung carcinoma, especially the squamous cell type. The purpose of this study was to assess the clinical value of CYFRA for squamous cell carcinoma of the head and neck and compare the results with squamous cell carcinoma antigen (SCCA). Serum levels of CYFRA were measured in 168 patients with a newly diagnosed head and neck squamous carcinoma. In addition, 77 patients without evidence of neoplasm were included as controls. At the same time, SCCA was also determined. The cut-off values of CYFRA and SCCA, determined at the 95th percentile of the standard Gaussian variate of controls, were 2.48 ng/ml and 1.49 ng/ml respectively. The diagnostic sensitivity of CYFRA was superior to that of SCCA, especially for nasopharyngeal carcinoma. The sensitivity of CYFRA for nasopharyngeal carcinoma was much higher (58.3%) than that of SCCA (15.5%). However, the sensitivity of CYFRA is not satisfactory in all types of squamous carcinoma. For oral cancer, the sensitivity is only 25.6%. CYFRA is a useful serum marker for patients with certain types of head and neck squamous carcinoma, such as nasopharyngeal carcinoma and hypopharyngeal carcinoma. In addition, CYFRA may be also useful in monitoring recurrence of certain types of SCCHN, which are sometimes difficult to detect.

Antigens, Neoplasm↗
PubMed1998

Value of gallium-67 scintigraphy in monitoring the renal activity in lupus nephritis.

In this study, we evaluated the relationship between the gallium uptake in the kidneys and the results of renal biopsy. The renal uptake of gallium in 32 patients with lupus nephritis were evaluated according to the classification of the World Health Organization, the activity index (AI), and the chronicity index (CI). AI was significantly higher in patients with a positive gallium scan when compared with patients with a negative gallium scan (p = 0.0007). However, change in gallium uptake was not related to the CI or WHO classification (p = 0.68 and p = 0.79 respectively). Of the 16 patients with AI > or = 9, 13 (81.25%) had a positive gallium scan, while only 3 (18.7%) of the patients with AI < 9 had a positive scan. In addition, all patients (100%) with AI > or = 11 showed a positive gallium scan. We conclude that renal imaging with gallium has a good correlation with AI, and may be a useful alternative to renal biopsy in patients with lupus nephritis.

Adolescent↗
PubMed1998

Ga-67 scintigraphy in lupus nephritis.

Lupus nephritis is a disease characterized by flareups and remissions. Evaluation of disease activity is important for therapeutic decisions and prognosis. In this study, 46 patients with lupus nephritis were evaluated by Ga-67 scintigraphy. Delayed 48-hour Ga-67 images were performed to evaluate kidney uptake. A patient with a 24-hour urinary protein excretion of 3 g or more or a serum creatinine level greater than 1.5 mg/dl was considered to have active lupus nephritis. Renal disease was active in 22 patients and inactive in 24 patients. Of the 22 patients with active renal disease, 18 (81.8%) showed positive Ga-67 results, whereas only 12.5% (3 of 24) of patients with inactive renal disease showed a positive Ga-67 study. The difference between the two groups was significant. Patients with positive Ga-67 scans had a significantly higher serum creatinine level and 24-hour urine protein value than patients with negative Ga-67 scans. In addition, all of the patients (100%) with a 24-hour urine protein greater than 4 g/day had a positive Ga-67 scan. It appears that Ga-67 scintigraphy is useful for the evaluation of disease activity in lupus nephritis.

Adult↗
PubMed1998

Diagnostic value of bone and Ga-67 imaging in skeletal tuberculosis.

Tuberculosis (TB) remains a major cause of skeletal infection in many parts of the world. Bone scintigraphy is an excellent screening test for bone lesions and Ga-67 scintigraphy is a useful tool for detecting inflammatory lesions. This study determined the value of bone and Ga-67 scans in patients with skeletal TB. Tc-99m MDP and Ga-67 whole-body scans were performed in 24 patients with proved skeletal TB. Twenty-six TB lesions were found in these 24 patients, 8 in the spine, 5 in the knee, 5 in the wrist, 4 in the ankle, 2 in the elbow, 1 in the finger, and 1 in the sacroiliac joint. Of the 26 TB lesions, Tc-99m MDP bone imaging detected 24 and Ga-67 scans revealed 23. The sensitivity rates were 92% (24 of 26) and 88.5% (23 of 26) for bone scans and Ga-67 scans, respectively. When the scans were evaluated in combination, the detection sensitivity was 96.1% (25 of 26). Two lesions that the bone scan failed to detect were in the spine. Ga-67 imaging failed to detect two spinal lesions and one lesion in the knee. The detection sensitivities of bone and gallium scans were high for skeletal TB, although neither scan was specific for TB lesions. Either the bone or Ga-67 scan can be used in the clinical setting as a convenient screening test to detect multiple sites of bone involvement in TB, and to indicate the sites for further detailed evaluation by CT, MRI, or biopsy.

Bone and Bones↗
PubMed1998

Identification of new renal scarring in repeated episodes of acute pyelonephritis using Tc-99m DMSA renal SPECT.

PURPOSE: This prospective study compared the value of Tc-99m DMSA renal planar scintigraphy with SPECT to detect new renal involvement in patients with repeated episodes of acute pyelonephritis (APN). MATERIALS AND METHODS: Children with suspected APN were transferred to our department for DMSA renal scans. Seventy-two children (ages 1 week to 15 years) had DMSA planar and SPECT imaging performed twice because of clinical or laboratory suspicion of repeated APN. In addition, radiographic voiding cystourethrography was also performed in all cases. The presence of vesicoureteral reflux (VUR) was graded on a scale of 0 to 5. RESULTS: New lesions were observed with SPECT in 56 kidneys and with planar scintigraphy in 38 kidneys. No patients had a negative result of Tc-99m DMSA renal SPECT who also had a positive Tc-99m DMSA planar result. The degree of VUR as related to APN was diagnosed better with SPECT than with planar scintigraphy (46 compared with 30 and 10 compared with 8, respectively). There is a significant difference (P < 0.05) between the diagnostic ability of these two methods to identify the increased tendency of repeated APN to occur with high-grade VUR compared with low-grade or no VUR. CONCLUSIONS: High-grade VUR is more commonly associated with renal injury than is low-grade or no VUR. If only Tc-99m DMSA renal planar scintigraphy is performed, renal scarring may be underestimated. Our results suggest that Tc-99m DMSA renal SPECT, rather than planar scintigraphy, should be used routinely in children with a clinical suspicion of APN, especially for those with scarred kidneys and high-grade VUR.

Acute Disease↗
PubMed1998

Rhenium-188 microspheres: a new radiation synovectomy agent.

Radiation synovectomy is efficacious in controlling the symptoms of rheumatoid arthritis. However, the procedure is not widely used because of concerns about leakage of radiopharmaceuticals from the treated joints. Leakage can be minimized by selecting particles of an appropriate size. In this study, we labelled microspheres with 188Re and analysed its biodistribution after intra-articular injection in rabbits with antigen-induced arthritis. Gamma camera imaging was performed to quantify the mean retention of 188Re in the knees. The mean retention of 188Re was 98.7, 94.6 and 93.6% at 1, 24 and 48 h, respectively. The biodistribution data revealed very low radioactivity in all organs at different times, which suggests the leakage of radiotracer from the knee was negligible. Our preliminary results indicate that 188Re microspheres are a potentially effective radiopharmaceutical for radiation synovectomy.

Animals↗
PubMed1998

Normal ranges of renal physiological parameters for technetium-99m mercaptoacetyltriglycine and the influence of age and sex using a camera-based method.

162 normal Chinese men and women underwent a 99mTc MAG3 renal study. Seventy-two males and 90 females were evaluated in 5 age groups: group 1, 61-80 years; group 2, 51-60 years; group 3, 41-50 years; group 4, 31-40 years, and group 5, 21-30 years. Each subject was required to fit the following criteria: (1) clinically no history of renal, urinary disorders and systemic diseases, normal blood pressure, kidney morphology, urinary examination and serum creatinine, and (2) for the gamma camera study normal hydration and renal images, and no pelvic, ureteric dilatation or retention of tracer should be found. The normal range of common physiological parameters for 99mTc MAG3 renal studies was measured in normal subjects. The effective renal plasma flow (ERPF, camera-based Schlegel method), percent function in each kidney (renal index, RI), time of peak renal parenchymal activity (Tmax) and half time of parenchymal activity following the peak (T1/2) were evaluated. The Tmax and T1/2 were determined with regions of interest over the entire kidney. The results showed that (1) between the sexes, there were no significant differences for any parameter; (2) between the age groups, the only significant difference was a decrease in ERPF, normalized for body surface area, with increasing age (group 1, 511.3 +/- 91.2; group 2, 559.5 +/- 102.1; group 3, 577.1 +/- 79.2; group 4, 607.8 +/- 101.1, and group 5, 610.2 +/- 109.2), and (3) the RI, Tmax and T1/2 were symmetrical and did not vary between the sexes or age groups (left vs. right: RI = 49.6 +/- 2.2 vs. 50.4 +/- 2.2%, Tmax = 3.63 +/- 1.13 vs. 3.75 +/- 1.11 min, and T1/2 = 5.38 +/- 1.65 vs. 5.83 +/- 1.88 min). We find that (1) ERPF for 99mTc MAG3 decreases with age in normal Chinese, which is similar to the results of Western countries, and (2) the RI, Tmax and T1/2 were symmetrical and did not vary between the sexes or age groups in normal Chinese, and are also similar to the results of Western countries.

Adult↗
PubMed1998

Premaxillary size and craniofacial growth in patients with cleft lip and palate.

BACKGROUND: Premaxillary size in individuals with cleft lip and palate is variable, ranging from a mere nubbin to a large protuberance. The purpose of this study was to evaluate the effect of premaxillary size on craniofacial growth in cleft lip and palate patients. MATERIALS AND METHODS: Premaxillary size was measured using 181 dental casts of bilateral complete cleft lip and palate (BCLP) infants. The infants had no associated systemic malformations, and were approximately one year of age. Data were obtained from the files of the Chang Gung Craniofacial Center. The mean size (mean = 19.3 mm) of the premaxilla and standard deviation (SD = 2.0 mm) were calculated. A sample of 55 subjects was divided into three groups: large premaxilla; [LP; 15 boys, 5 girls; mean age 5.2 years; premaxillary size > (19.3 + 2.0) mm; mean size 22.6 mm]; small premaxilla [SP; 15 boys, 5 girls; mean age = 5.1 years; premaxillary size < (19.3-2.0) mm; mean size = 16.5 mm] and bilateral-median facial dysplasia [B-MFD; 6 boys, 9 girls; mean age 5.1 years; mean size 10.5 mm]. They all had a bilateral cheiloplasty at about 3 months of age and palatoplasty at about one year of age. Lateral cephalograms were taken at about 5 years of age to compare the craniofacial complex among the three groups. RESULTS: The LP group tended to have a longer maxilla, longer anterior maxillary height and more protruded maxilla, producing a better interjaw relation and larger overjet. The opposite phenomena were observed in the B-MFD group, and the SP group had results between those of the LP group and the B-MFD group. CONCLUSION: BCLP patients with large premaxilla had superior maxillary growth (in depth and anterior height) as compared to those with small premaxilla.

Child↗
PubMed1998

The value of CYFRA 21-1, a new tumor marker, in nasopharyngeal carcinoma.

CYFRA 21-1 (CYFRA) is a newly-developed tumor marker which is useful in evaluating non-small cell lung carcinoma, especially the squamous cell type. The purpose of this study was to assess the clinical value of CYFRA in patients with nasopharyngeal carcinoma (NPC). Serum levels of CYFRA (CIS bio-International, France) were measured in 80 patients with untreated NPC. The histologic diagnosis of all patients was confirmed by biopsy. Twenty two (27.5%) of the tumors were classified as undifferentiated carcinoma, and 58 (72.5%) as squamous cell carcinoma. All patients with malignancy were classified according to the International Union Against Cancer (UICC) TNM classification system. In addition, 77 patients without evidence of neoplasm were included as controls. The cut-off value of CYFRA, determined at the 95th percentile of the standard Gaussian variate of controls, was 2.48 ng/ml. The results show that (1) the mean values of serum CYFRA in patients with NPC were significantly higher than those in the control subjects, (2) the overall diagnostic sensitivity of CYFRA in patients with NPC is 58.75%, (3) there was no significant difference between the CYFRA concentrations in patients with squamous cell carcinoma and those in patients with undifferentiated carcinoma, and that (4) there was good correlation between CYFRA values and the tumor stage. There is a statistical difference between T1-T2 patients and T3-T4 patients, and between N0 to N1 patients and N2 to N3 patients. Our results suggest that the CYFRA test may have a potential clinical role as a valuable test in patients with NPC.

Antigens, Neoplasm↗