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Biomedical subjects

C Y Lin

Publications and source records attributed to C Y Lin.

At least 109 records · Page 6Linked to original sources
PubMed2000

Lingual osteoma: case report.

Lingual osteoma, a rare clinical entity, has been found mainly in the posterior region of tongue. It mostly affects women in their third and fourth decades of life and occurs less frequently in men. We report an unusual case of a 42-year-old male patient who developed a lingual osteoma near the foramen cecum. The patient underwent excision of the tumor mass under local anesthesia and had an uneventful postoperative course. Symptoms of the mass effect were noted to resolve after surgical intervention. Histologically, mature lamellar bone with haversian systems was seen. The pathogenesis of this rare tumor is a controversial problem and its nomenclature also remains an issue of debate. Discussion of the controversial pathogenesis of lingual osteoma and a review of the literature on its clinical characteristics are included in this report.

Adult↗
PubMed1999

Molecular characterization of Oryza sativa 16.9 kDa heat shock protein.

A rice class I low-molecular-mass heat shock protein (LMM HSP) Oshsp 16.9 was overexpressed in Escherichia coli. Oligomerized complexes of Oshsp16.9 were harvested and electron microscopic observations of purified complexes revealed globular structures of 10-20 nm in diameter (with majority of 15-18 nm) and calculated to comprise approx. 12 monomers per complex. In comparison, complexes from native rice class I LMM HSPs were observed as larger ellipsoid- or globular-like random aggregated hetero-oligomers. To characterize the biochemical functions of the hydrophobic N-terminal region of Oshsp16.9, a truncation in the N-terminal region was constructed and introduced into E. coli. Results showed that the N-terminal truncated Oshsp16.9 mutant was capable of forming complexes similar to the full-length Oshsp16.9; however, the deletion protein failed to confer in vitro protein thermostability under elevated temperatures. Protein assays from in vivo treatments at higher temperatures exhibited that non-specific interactions of E. coli cellular proteins only occurred with full-length Oshsp16.9 complexes but not with the mutant complex. In vitro immunoprecipitation of cellular proteins from E. coli overexpressing full-length Oshsp16.9 showed that interactions between plant LMM HSP and E. coli cellular proteins are temperature-dependent. Taken together, the hydrophobic N-terminal region of rice class I LMM HSP is critical in the ability of the protein to interact/bind with its potential substrates.

Amino Acid Sequence↗
PubMed1999

Indirect detection of organic acids in non-aqueous capillary electrophoresis.

Non-aqueous capillary electrophoresis (NACE) with indirect detection has been applied to the determination of fatty acids (FAs) and ascorbic acid (AA), respectively. C2-C18 FAs have been separated in less than 12 min using 8-hydroxy-7-iodoquinoline sulfonic acid as chromophores in NACE with indirect absorbance. The dissociation constant (pKa) values of C8-C18 FAs obtained from the slope of the linear plot -log [(mu 0/mu)-1] vs. pH, using 20% isopropanol and 40% acetonitrile as the organic modifier in NACE, are all above about two units than those obtained in aqueous solution. NACE with indirect laser-induced fluorescence, using merocyanine 540 (MC540) as fluorophores, has been performed to the analysis of AA and its stereoisomer, isoascorbic acid (IAA), and the limits of detection of AA and IAA are 0.30 microM and 0.17 microM, respectively. This method has been applied to the determination of AA in a lemon juice spiked with IAA as the internal standard in less than 3 min and its concentration is 76.7 +/- 0.4 mM.

Ascorbic Acid↗
PubMed1999

Molecular cloning of a cold-shock domain protein, zfY1, in zebrafish embryo(1).

Cold-shock domain proteins in vertebrates contain a highly conserved domain which is related to the Escherichia coli cold-shock proteins. Here we report the cloning of a cold-shock domain protein from zebrafish embryo. Using the combination of PCR techniques with degenerate primers, 5'RACE and 3'RACE, the full length cDNA of a cold-shock domain protein in the zebrafish embryo was successfully cloned without constructing and screening a library. Determined from the deduced amino acid sequence, this protein is most similar to Xenopus, FRGY1, and this newly cloned zebrafish gene was therefore designated as zfY1.

Amino Acid Sequence↗
PubMed1999

Molecular cloning of cDNA for matriptase, a matrix-degrading serine protease with trypsin-like activity.

A major protease from human breast cancer cells was previously detected by gelatin zymography and proposed to play a role in breast cancer invasion and metastasis. To structurally characterize the enzyme, we isolated a cDNA encoding the protease. Analysis of the cDNA reveals three sequence motifs: a carboxyl-terminal region with similarity to the trypsin-like serine proteases, four tandem cysteine-rich repeats homologous to the low density lipoprotein receptor, and two copies of tandem repeats originally found in the complement subcomponents C1r and C1s. By comparison with other serine proteases, the active-site triad was identified as His-484, Asp-539, and Ser-633. The protease contains a characteristic Arg-Val-Val-Gly-Gly motif that may serve as a proteolytic activation site. The bottom of the substrate specificity pocket was identified to be Asp-627 by comparison with other trypsin-like serine proteases. In addition, this protease exhibits trypsin-like activity as defined by cleavage of synthetic substrates with Arg or Lys as the P1 site. Thus, the protease is a mosaic protein with broad spectrum cleavage activity and two potential regulatory modules. Given its ability to degrade extracellular matrix and its trypsin-like activity, the name matriptase is proposed for the protease.

Amino Acid Sequence↗
PubMed1999

Purification and characterization of a complex containing matriptase and a Kunitz-type serine protease inhibitor from human milk.

Matriptase, a trypsin-like serine protease with two potential regulatory modules (low density lipoprotein receptor and complement C1r/s domains), was initially purified from T-47D breast cancer cells. Given its plasma membrane localization, extracellular matrix-degrading activity, and expression by breast cancer cells, this protease may be involved in multiple aspects of breast tumor progression, including cancer invasion. In breast cancer cells, matriptase was detected mainly as an uncomplexed form; however, low levels of matriptase were detected in complexes. In striking contrast, only the complexed matriptase was detected in human milk. The complexed matriptase has now been purified. Amino acid sequences obtained from the matriptase-associated proteins reveal that they are fragments of a Kunitz-type serine protease inhibitor that was previously reported to be an inhibitor of the hepatocyte growth factor activator. In addition, matriptase and its complexes were detected in milk-derived, SV40 T-antigen-immortalized mammary luminal epithelial cell lines, but not in human foreskin fibroblasts or in HT-1080 fibrosarcoma cells. These results suggest that the milk-derived matriptase complexes are likely to be produced by the epithelial components of the lactating mammary gland in vivo and that the activity and function of matriptase may be differentially regulated by its cognate inhibitor, comparing breast cancer with the lactating mammary gland.

Amino Acid Sequence↗
PubMed1999

Latent variables, measurement error and methods for analysing longitudinal binary and ordinal data.

We explore structural equations with latent variables for modelling between-individual variability and measurement error in the analysis of longitudinal binary and ordinal data. The structural equation formulation provides insight into the assumptions and differences in interpretation of methods that are popular for longitudinal data analysis. Introducing the concept of continuous latent variables makes it clear that marginal and cluster-specific models differ because their predicted variables are scaled to different standard deviations, and that adjustment for measurement error in the outcome involves a change in scale as well. We apply both structural equation modelling and common longitudinal modelling approaches to data from a study of sleep disorders. In the process, we compare results from marginal modelling using an SAS GEE routine (Karim and Zeger, 1988), Qu's GAUSS program (Qu, 1992) for generalized mixed models using GEE, the MIXOR package for cluster-specific mixed effects models (Hedeker and Gibbons, 1994), and LISCOMP for structural models (Muthén, 1988).

Adult↗
PubMed1999

Efficacy of a pure compound H1-A extracted from Cordyceps sinensis on autoimmune disease of MRL lpr/lpr mice.

Cordyceps sinensis (CS) is a traditional Chinese medicine with immunomodulatory effect and is effective in improving the survival of lupus mice. In the present study we isolated a pure compound (H1-A) from CS and investigated its effect on inhibiting autoimmune disease progression in MRL Ipr/Ipr mice. Our results demonstrated that MRL Ipr/Ipr mice treated daily with H1-A (40 microg/kg/d orally) for 8 weeks had a progressive reduction in anti-ds-DNA production (optical density value decreased from 0.172 +/- 0.009 to 0.112 +/- 0.015) when compared with the control group (optical density value increased from 0.141 +/- 0.036 to 0.198 +/- 0.047). In clinical presentation, the treated group had a reduction in lymphadenopathy, a delayed progression of proteinuria, and an improvement in kidney function. Histologic analysis of kidney tissue indicated that H 1-A could inhibit the mesangial proliferation that was evident in lupus nephritis. However, there was no significant change in immune complex deposition. The studies reveal that the pure compound (H1-A) may be potentially useful for treating systemic lupus erythematosus in human patients, and they provide some questions for further investigation of the pathogenesis of systemic lupus erythematosus and lupus nephritis.

Animals↗
PubMed1999

Blocking of cell proliferation, cytokines production and genes expression following administration of Chinese herbs in the human mesangial cells.

In the hope of identifying agents of therapeutic value in immuoglobulin A nephropathy (IgA-N), we tested crude methanol extracts of 15 Chinese herbs for their effect on human mesangial cell proliferation. The results indicated that 4 out of the 15 crude extracts inhibited human cells proliferation activated by IL-1beta and IL-6. The extracts and their median inhibitory concentrations were as follows (in microg/ml): Ludwiga octovalvis (MLS-052), 49.9 +/- 1.8; Rhus semialata (MLS-053), 31.2 +/- 1.6; Tabernaemontana divaricata (MLS-054), 50.0 +/- 2.1; Amepelopsis brevipedunculata (MLS-059), 42.9 +/- 1.1. These findings indicate that human mesangial cells were most sensitive to MLS-053 treatment. These herbs also decreased interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) production. Moreover, IL- 1beta mRNA expression was inhibited by Rhus semialata (R. semialata; MLS-053). It is unlikely that cytotoxicity was involved, because no cell deaths were observable. We hypothesize that the inhibitory mechanisms of these Chinese herbs may be related to the impairments of gene expression and production of cytokines in human mesangial cells. Plans are underway for the isolation of pure compounds from these Chinese herbs and the elucidation of their mechanisms of action.

Cell Division↗
PubMed1999

Inhibition of activated human mesangial cell proliferation by the natural product of Cordyceps sinensis (H1-A): an implication for treatment of IgA mesangial nephropathy.

Cordyceps sinensis (CS) is a parasitic fungus that has been used as a Chinese medicine for a long time in the treatment of nephritis. Today, the hypothesis about the pathogenesis of immunoglobulin A nephropathy (IgAN) is that nephritogenic IgA immune complexes (IgAIC) go to the kidney to stimulate resting mesangial cells to release cytokines and growth factors. These cytokines and growth factors cause mesangial cell proliferation and release matrix, chemical mediators that lead to the glomerular injury. However, nephritogenic IgAIC in humans is still unknown. To solve this problem previously, we established an in vitro model that showed that cultured human mesangial cells (HMC) stimulated with interleukin-1 (IL-1) plus IL-6 can cause mesangial cell proliferation, increasing production of chemical mediators and superoxide anion. An in vivo model also proved that this culture medium may lead to renal injury with hematuria and proteinuria. Therefore, to fractionate the crude components that can be used in the treatment of patients with IgAN, we cultured HMC, and then an HMC activating model with HMC incubated with IL-1 and IL-6 was established. We fractionated the crude methanolic extracts from fruiting bodies of CS with the use of this in vitro inhibition of HMC activation model as our assay method. In brief, the fruiting bodies were extracted by silica gel column chromatography. One out of 6 column fractions, F-2, significantly inhibited the HMC activation by IL-1 plus IL-6. The acute toxicity test with male Institute of Cancer Research mice showed no liver toxicity or mutagenicity. Then we established an IgAN animal model with R36A (Pneumococcal C-polysaccharide purified from Streptococcus pneumoniae) as antigen and anti-R36A IgA monoclonal antibody to form nephritogenic IgA-IC, which can induce hematuria and proteinuria in mice with IgA deposition in the mesangial area. The mice in the IgAN model fed with 1% F-2 in diet had significant reduction of hematuria and proteinuria together with histopathologic improvement. Therefore this fraction was then purified by silica gel column chromatography and high-performance liquid chromatography, which got a purified compound H1-A, which can suppress the activated HMC and alleviate IgAN (Berger's disease) with clinical and histologic improvement. These results give us a new regimen for the treatment of patients with IgAN in the future.

Adolescent↗
PubMed1999

Double cancers of the kidney and ureter complicated with emphysematous pyelonephritis within the parenchyma of the renal tumour.

Emphysematous pyelonephritis and double cancers of the kidney and urinary tract are rare. We describe here a case of a diabetic man who had simultaneous renal cell carcinoma of the right kidney and transitional cell carcinoma of the right ureter complicated with emphysematous pyelonephritis within the tumour parenchyma of renal cell carcinoma. Imaging and pathology are demonstrated.

Aged↗
PubMed1999

Lamotrigine attenuates cortical glutamate release during global cerebral ischemia in pigs on cardiopulmonary bypass.

BACKGROUND: The dose-response effects of pretreatment with lamotrigine (a phenyltriazine derivative that inhibits neuronal glutamate release) in a porcine cerebral ischemia model during cardiopulmonary bypass were studied. METHODS: Sagittal sinus catheters and cortical microdialysis catheters were inserted into anesthetized pigs. Animals undergoing normothermic cardiopulmonary bypass were pretreated with lamotrigine 0, 10, 25, or 50 mg/kg (n = 10 per group). Fifteen minutes of global cerebral ischemia was produced, followed by 40 min of reperfusion and discontinuation of cardiopulmonary bypass. Cerebral oxygen metabolism was calculated using cerebral blood flow (radioactive microspheres) and arterial-venous oxygen content gradients. Concentrations of microdialysate glutamate and aspartate were quantified; electroencephalographic signals were recorded. After cardiopulmonary bypass, blood and cerebrospinal fluid were sampled for S-100B protein, and a biopsy was performed on the cerebral cortex for metabolic profile. RESULTS: Lamotrigine caused dose-dependent reductions in systemic vascular resistance so that additional fluid was required to maintain venous return. Concentrations of glutamate and aspartate did not change during reperfusion after 50 mg/kg lamotrigine in contrast to fivefold and twofold increases, respectively, with lower doses. There were no intergroup differences in cerebral metabolism, electroencephalographic scores, cortical metabolites, brain lactate, or S-100B protein concentrations in the cerebrospinal fluid and blood. CONCLUSIONS: Lamotrigine 50 mg/kg significantly attenuated excitatory neurotransmitter release during normothermic cerebral ischemia during cardiopulmonary bypass without improving other neurologic parameters. Lamotrigine caused arterial and venous dilation, which limits its clinical usefulness.

Analgesics↗
PubMed1999

The value of Ga-67 renal SPECT in diagnosing and monitoring complete and incomplete treatment in children with acute pyelonephritis.

PURPOSE: This study evaluated the utility of Ga-67 renal SPECT for diagnosing acute pyelonephritis (APN) in children and monitoring them. METHODS: Seventy-one children (ages 1 week to 12 years) who were thought clinically to have APN were included in the study. The disease was considered present if the patients had all of the following: fever (38.5 degrees C), pyuria (leukocyte counts/per high-power field > or = 10), and a positive result of a urinary culture or blood culture. Tc-99m DMSA, Ga-67 renal SPECT, and voiding cystourethrography were performed, with informed consent from the patients' parents, within 3 days after hospitalization. Three months after treatment, Tc-99m DMSA and Ga-67 renal SPECT were repeated in those patients who had abnormal results of the initial Ga-67 renal SPECT. RESULTS: In the diagnostic study, Ga-67 renal SPECT was superior to DMSA renal SPECT in detecting lesions (97% vs. 79%). Three children had false-negative results with Ga-67 renal SPECT. Seventeen kidneys were negative with Tc-99m DMSA but positive with Ga-67 renal SPECT. No patients had any Ga-67 uptake on post-therapy imaging. However, 32 of 107 kidneys (30%) had permanent renal scars. In these 107 kidneys, 78 (73%) were associated with high-grade vesicoureteral reflux (VUR; VUR grade > or = 3) and 29 (27%) with low-grade or no VUR. CONCLUSIONS: High-grade VUR tends to be associated more with APN than has been reported by others, probably because of an underestimation of APN by ultrasonography or DMSA. Ga-67 renal SPECT is sensitive and useful not only in diagnosis but also for monitoring and follow-up of children with clinical suspicion of APN, especially in those with equivocal results after DMSA renal SPECT studies.

Acute Disease↗
PubMed1999

Clinical significance of rebound nystagmus.

OBJECTIVE/HYPOTHESIS: Magnetic resonance imaging (MRI) examination is performed in cases of rebound nystagmus to elucidate the responsible site for rebound nystagmus. METHODS: Patients with vertigo or tinnitus received a battery of audiological and neuro-otological tests. Those who had rebound nystagmus were rechecked by electronystagmography and examined by MRI. RESULTS: Ten patients had a second-degree nystagmus evoked by changing direction of fixation, from the lateral to the forward gaze. All patients displayed positive MRI findings in cerebellum or brainstem, including tumor in seven cases and stroke in three cases. Moreover, in seven of eight cases with unilateral lesions, rebound nystagmus was ipsilateral with respect to the side of the lesion. CONCLUSION: Rebound nystagmus implies a lesion in cerebellum or brainstem for which MRI examination is 100% sensitive. It has a certain lateralizing value, with its direction away from the lesioned side.

Adolescent↗
PubMed1999

A retrospective study of clozapine and urinary incontinence in Chinese in-patients.

OBJECTIVE: This study investigated the incidence of clozapine-associated urinary incontinence (UI) in schizophrenic patients, the percentage of these patients with persistent urinary incontinence (PUI), and the possible factors affecting the occurrence of UI. METHOD: A total of 61 Chinese in-patients with schizophrenia (according to DSM-IV) treated with clozapine for more than 3 months were assessed retrospectively for the occurrence of UI. Patients who still had UI at the time of assessment were classified as having PUI. Patients whose UI had resolved at the time of assessment were classified as having self-limited urinary incontinence (SUI). We compared the characteristics of UI and non-UI cases and of PUI and SUI cases. RESULTS: The results showed that urinary incontinence developed at some time in 27 of 61 patients (44.3%), and that it was persistent in 15 of 61 patients (25%). There were no statistically significant differences in age, sex, clozapine dose, duration of clozapine use, duration of index admission, duration of illness, age at onset of schizophrenia, or concurrent treatment with other psychiatric medications between the UI and non-UI groups and between the PUI and SUI groups. CONCLUSION: Clozapine-associated urinary incontinence may be persistent in some patients, and it should be cautiously monitored in every patient taking clozapine.

Adult↗
PubMed1999

Expression of cyclin D1 is correlated with poor prognosis in patients with areca quid chewing-related oral squamous cell carcinomas in Taiwan.

Abnormal expression of cell cycle regulatory proteins, particularly cyclin D1, has been implicated in the pathogenesis of several types of cancer. We have examined the expression of cyclin D1 in histological sections of oral squamous cell carcinomas (SCCs) using anti-cyclin D1 antibodies with an immunoperoxidase technique. Cyclin D1 nuclear staining was observed in 73 of 88 (83%) cases of oral SCC. In 54 of these 73 (74%) cases, positive cyclin D1 staining was also found in the normal appearing epithelium immediately adjacent to the cyclin D1-positive SCCs. No significant correlation was found between the expression of cyclin D1 and the patients' age, sex, oral habits, cancer location and STNM status. The Kaplan-Meier analysis showed that patients with tumors containing more than 10% cyclin D1-positive cells had significantly shorter overall survival than those with tumors containing less than 10% cyclin D1-positive cells or with cyclin D1-negative tumors (P<0.05). Patients with positive lymph node status also had significantly shorter overall survival (P<0.01). These results indicate that cyclin D1 may play an important role in the genesis of oral SCC and may serve as an adjuvant marker of worse prognosis in patients with oral SCCs in Taiwan.

Adult↗
PubMed1999

Apolipoprotein E genotype and schizophrenia.

Schizophrenic disorders are complex genetic disorders and may involve multiple genes of small effect. The presence of apolipoprotein E (apoE) is associated with several neuropsychiatric disorders. Previous studies on apoE genotype distribution in schizophrenia have reported conflicting findings. We studied the genotype frequencies in a large group of schizophrenic patients. The genotype distribution was significantly different between the schizophrenic patients and the control subjects. Persons who were sigma3 carriers have an increased risk of schizophrenia. This result suggests that apoE isoforms may play a functional role in the pathogenesis of schizophrenic disorders. Some possible mechanisms regarding the effect of apoE on the development of schizophrenia are discussed.

Aging↗