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Biomedical subjects

C S Lin

Publications and source records attributed to C S Lin.

At least 19 recordsLinked to original sources
PubMed2006

Geometric and excited-state properties of 1,4-bis(benzothiazolylvinyl)benzene interacting with 2,2',2' '-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole] studied by a density-functional tight-binding method.

The energetics and luminescent property of a guest molecule, 1,4-bis(benzothiazolylvinyl)benzene (BT), interacting with a host molecule, 2,2',2' '-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole] (TPBI), in organic light-emitting diodes are studied by performing excited-state calculations using a time-dependent density-functional tight-binding method complemented with dispersion energy. It is found that the overlap between the TPBI emission and the BT absorption spectra shows an efficient energy transfer from the host molecule to the guest molecule when they are excited. The planar BT molecule becomes distorted when it is mixed with TPBI, resulting in a blue luminescence around 475 nm. The separation of the TPBI + BT mixture on a graphite surface is found to be energetically favorable, consistent with experimental observation.

Journal Article↗
PubMed2006

Establishment and characterization of a spontaneously immortalized porcine mammary epithelial cell line.

We have established a spontaneously immortalized porcine mammary epithelial cell line (SI-PMEC) from the mammary gland of a lactating sow and maintained it long-term in culture by continuous subculturing. SI-PMEC cells were maintained for more than 8 months (70 passages) in DMEM/F12 medium supplemented with 10% fetal calf serum, insulin, and hydrocortisone without obvious signs of senescence. When grown at low density on a plastic substratum, SI-PMEC cells formed islands, and when grown to confluency, the cells formed a monolayer and aggregated with the characteristic cobblestone morphology of epithelial cells. The subcultured SI-PMEC cells appeared to proliferate without changes in morphology or growth pattern, with an estimated population doubling time of 20-22 h. With increasing density, SI-PMEC cells organized into lumen-like structures with elongated cells at the margins. SI-PMEC cells from stocks frozen at Passage 30 were subcultured up to 20 times without changes in cell viability, proliferation rate, or morphology. Furthermore, SI-PMEC cells remained immunopositive to an antibody against cytokeratin AE3 and immunonegative to an antibody against a human fibroblast antigen. The SI-PMEC cells could form functional structures resembling ducts, lateral-buds, and alveoli in a Matrigel matrix-dependent manner in vitro. When grown on the Matrigel and stimulated by prolactin, the cells differentiated and formed mammary gland structures and strongly expressed transcripts encoding the milk proteins alpha-lactalbumin, beta-casein, and beta-lactoglobulin. Our results indicate that the SI-PMEC cell line can be subpassaged many times and still form functional differentiated secretory structures. To our knowledge, this is the first report of an immortalized mammary epithelial cell line from pig.

Animals↗
PubMed2006

Detection of gentoxicity of benzidine and its derivatives with the Escherichia coli DJ 702 lacZ reversion mutagenicity assay.

AIMS: The feasibility of Escherichia coli DJ 702 lacZ mutagenicity assay to detect genotoxicity of benzidine and its derivatives was evaluated. METHODS AND RESULTS: DJ 702 strain was grown overnight at 30 degrees C in Luria-Bertani (LB) medium containing some components, such as chloramphenicol, ampicillin, delta-aminolevulinic acid, isopropyl-beta-d-thiogalactoside, and trace element mix. The mixtures of a bacterial culture and tested chemical at indicated doses were incubated at 30 degrees C for 30 min. Subsequently, 2 ml of molten top agar was added and the resulting mixtures were immediately poured onto a minimal lactose (ML) plate. Plates were incubated at 30 degrees C for 48 h. The number of colonies was determined by visual scoring. In this study, results showed that all the tested chemicals were mutagenic to DJ 702 strain. CONCLUSIONS: E. coli lac mutagenicity assay using DJ 702 strain can detect the mutagenicity of benzidine and its derivatives. SIGNIFICANCE AND IMPACT OF THE STUDY: We detected the mutagenicity of benzidine and its derivatives in E. coli lac mutagenicity assay using DJ 702, indicating that this assay may be used to detect benzidine and its derivatives in a powerful, sensitive, and convenient mutagenesis assay.

Benzidines↗
PubMed2005

Simulation of water cluster assembly on a graphite surface.

The assembly of small water clusters (H2O)n, n = 1-6, on a graphite surface is studied using a density functional tight-binding method complemented with an empirical van der Waals force correction, with confirmation using second-order Møller-Plesset perturbation theory. It is shown that the optimized geometry of the water hexamer may change its original structure to an isoenergy one when interacting with a graphite surface in some specific orientation, while the smaller water cluster will maintain its cyclic or linear configurations (for the water dimer). The binding energy of water clusters interacting with graphite is dependent on the number of water molecules that form hydrogen bonds, but is independent of the water cluster size. These physically adsorbed water clusters show little change in their IR peak position and leave an almost perfect graphite surface.

Journal Article↗
PubMed2005

Calcium/poly(9,9-dioctylfluorene) interaction: a theoretical study.

The geometric and electronic structures of poly(9,9-dioctylfluorene) (PFO) oligomer interacting with Ca atoms were studied using Møller-Plesset perturbation theory. A weak interaction with little charge transfer and with a relatively long Ca-C distance (about 4.0 Angstrom) was found when only one Ca atom was attached to a PFO unit. However, when two Ca atoms were adsorbed at a PFO unit, a strong interaction with a shorter Ca-C distance (about 2.67 Angstrom) took place with considerable charge transfer from the Ca atom to the PFO, resulting in significant deformation in the backbone of the PFO oligomer. In the latter case, the frontier orbitals of the PFO were modified. However, the deformed PFO and its modified frontier orbitals could be recovered when oxygen was added, which is in good agreement with experimental observation.

Journal Article↗
PubMed2005

Interactions of Li, Ca, and Al with aromatic carbon materials: an ab initio study.

The interactions of benzene (C6H6), naphthalene (C10H8), and perinaphthene (C13H9) with metal atoms (Li, Ca, and Al) were studied using second-order Møller-Plesset perturbation theory. By analyzing the frontier molecular orbitals, geometric structures, binding energies, and charge transfers, it was found that these metal atoms can bond strongly with C13H9, but can only bond weakly with C6H6 and C10H8. The bonding nature between a metal atom and C13H9 at their ground state depends significantly on the valence orbital of the metal atom and the pi-bonding distribution of the aromatic hydrocarbons. The spindly shaped 3p valence orbital of an Al atom results in the deviation of the adsorption site to the edge of C13H9, whereas the ball-shaped 2s/4s valence orbitals of a Li and a Ca atom facilitate their overlap with the second lowest unoccupied molecular orbital of C13H9. Further, Hartree-Fock and density-functional theory methods were demonstrated generally to be unreliable in describing the interactions of metal atoms with these pi systems.

Journal Article↗
PubMed2005

Gene transfection and expression in a primary culture of mammary epithelial cells isolated from lactating sows.

Porcine mammary epithelial cells (PMECs) were isolated from lactating sow mammary glands and cultured on a matrix gel. Primary culture cells expressed significant amounts of the specific marker cytokeratin as determined by immunohistochemistry, and exhibited mammary-specific functions, such as transcription of alpha-lactalbumin, beta-casein and beta-lactoglobulin genes. They also formed mammospheres when the medium was supplemented with lactogenic hormones. The PMECs were used to study gene transfer and expression in vitro. A gene encoding enhanced green fluorescent protein (EGFP) was used as a reporter and two constructs were investigated, pEGFP-N1 (a vector constructed with a CMV promoter followed by the EGFP gene) and pGB562/GFP (a mammary gland-specific expression vector with regulatory sequences from the goat beta-casein gene linked to EGFP). The efficiency of DNA transfer into the cultured PMECs was about 20-30%. GFP expression in the pGB562/GFP-transfected PMECs was markedly stimulated by prolactin supplements in the medium. The established PMECs maintained optimal gene expression from 1 to 20 passages and appeared to provide an efficient and convenient system for assessing the expression of transgenes containing mammary gland-specific promoters.

Animals↗
PubMed2005

Differentially transcribed genes in skeletal muscle of Duroc and Taoyuan pigs.

The objective of this study was to compare gene transcription profiles of LM between two pig breeds, Duroc and Taoyuan, which display dramatically different postnatal muscle growth. We isolated LM from neonatal pigs, and the Duroc muscle length and mass were greater (P < 0.01) than for Taoyuan pigs; however, insignificant differences in the muscle fiber area and the percentage of fiber types were found. A human high-density complementary DNA (cDNA) microarray consisting of 9,182 probes was used to compare gene transcription profiles of LM between the two breeds. The results showed that the transcription level of 73 genes and 44 genes in Duroc LM were upregulated and down-regulated by at least 1.75-fold (P < 0.05) compared with Taoyuan, respectively. The strongly upregulated genes in Duroc pigs included those encoding the complex of myofibrillar proteins (e.g., myosin light and heavy chains, and troponin), ribosomal proteins, transcription regulatory proteins (e.g., skeletal muscle LIM protein 1 [SLIM1] and high-mobility group proteins), and energy metabolic enzymes (e.g., electron-transferring flavo-protein dehydrogenase, NADH dehydrogenase, malate dehydrogenase, and ATP synthases). The highly transcribed genes that encode energy metabolic enzymes indicate a more glycolytic metabolism in Duroc LM, thereby favoring carbohydrates rather than lipids for use as energy substrates in this tissue. The over-transcribed genes that encode skeletal muscle-predominant proteins or transcription regulators that control myogenesis and/or muscle growth suggest a general mechanism for the observed higher rate of postnatal muscle growth in Duroc pigs. The transcription of one such gene, SLIM1, was more highly transcribed (P < 0.01) in Duroc LM at birth and at postnatal d 7 than in Taoyuan. The transcription of SLIM1 increased (P < 0.05) in Duroc LM from neonate through 7 d of age, whereas its transcription remained essentially constant in Taoyuan during this period. These results suggest that SLIM1 may be useful for the development of markers associated with the postnatal muscle growth of pigs.

Animals↗
PubMed2004

Rational pharmacotherapy in the diabetic hypertension: analysis-prescribing patterns in a general hospital in Taiwan.

OBJECTIVES: To examine prescribing at a 2800-bed hospital, also providing ambulatory services for 9000 visits per day, with a view to assessing the extent to which it followed international guidelines for treating diabetic hypertension. METHOD: Patients receiving antidiabetic and antihypertensive drugs concomitantly during the 4-week study period were included. RESULT: Of the 5015 eligible patients, most received combination antidiabetic therapy. Oral antidiabetic agents used alone or in combination included (in descending order) metformin, glibenclamide, gliclazide, glipizide, glimepiride and alpha-glucosidase inhibitors. Gliclazide accounted for most of the oral antidiabetic drug expenditure. Sulfonylurea plus metformin was the most popular regimen. Prescriptions for long-acting sulfonylureas did not differ between elderly and younger patients. For blood pressure control, calcium-channel blockers were most commonly used alone and overall, although current guidelines suggest that they should be second-line treatments. Inappropriate use of immediate-release nifedipine was noted. The combination, atenolol >100 mg/day and hydrochlorothiazide 50 mg/day (or an equivalent) were extensively used. Among 54.7% patients treated with combination antihypertensives, calcium-channel blockers and an angiotensin-converting enzyme inhibitor were most commonly used. CONCLUSION: Most diabetic hypertensive patients were treated with combination therapy for glucose and blood pressure control. Prescriptions for antihypertensive drugs often differed from current guidelines, especially in the choice of agents and their combinations.

Aged↗
PubMed2004

A double-blind comparison of the efficacy and tolerability of telmisartan 40-80 mg vs. losartan 50-100 mg in Taiwanese hypertensive patients.

A multicentre, randomised, double-blind, double-dummy, parallel-group, dose-titration study was conducted to determine the efficacy and tolerability of telmisartan 40-80 mg once daily compared with losartan 50-100 mg once daily in 180 Taiwanese patients with mild-to-moderate essential hypertension. After an initial 2-week placebo run-in phase, patients were randomised in a double-blind, double-dummy fashion to receive either telmisartan 40 mg or losartan 50 mg. If blood pressure control (diastolic blood pressure [DBP] <90 mmHg or > or = 10 mmHg reduction in DBP) was achieved after 4 weeks, the dose was maintained for the second 4 weeks of the active treatment phase; if not, the dose was doubled to telmisartan 80 mg or losartan 100 mg, respectively, for the second 4 weeks of double-blind treatment. Telmisartan 40-80 mg (n = 86) was as effective as losartan 50-100 mg (n = 90) in reducing trough seated DBP (11.1 vs. 8.7 mmHg, p = 0.144), and was significantly more effective than losartan in reducing trough seated systolic blood pressure (SBP) (22.1 vs. 16.5 mmHg, p = 0.032) and standing SBP (21.0 vs. 16.3 mmHg, p = 0.033). Significantly fewer patients treated with telmisartan than those treated with losartan required uptitration after 4 weeks' treatment (32.6% vs. 61.5%, p = 0.001). Both telmisartan and losartan were well tolerated.

Adult↗
PubMed2004

Bone marrow fat and bone mineral density on proton MR spectroscopy and dual-energy X-ray absorptiometry: their ratio as a new indicator of bone weakening.

OBJECTIVE: Bone weakening can be affected by agents other than bone mineral density (BMD). Increased bone marrow fat may have a direct link to bone loss. This pilot study analyzes the relationship between bone marrow fat and BMD in subjects with normal and structurally weakened vertebrae. SUBJECTS AND METHODS: Twenty-six subjects underwent both dual-energy X-ray absorptiometry and proton MR spectroscopy of 71 lumbar vertebrae. Fifteen subjects had normal-appearing vertebrae on MRI, and 11 had signs of bone weakening. RESULTS: We found that high bone marrow fat did not consistently equate with low BMD. Bone marrow fat can indicate bone weakening nearly as well as BMD, but neither parameter alone is suitable to be used independently as an indicator. The bone marrow fat/BMD ratio showed significant diagnostic power to detect bone weakening, even in this relatively small subject sample. CONCLUSION: An inverse relationship between bone marrow fat and BMD could not be confirmed. Bone marrow fat can be used to diagnose reduced bone strength nearly as well as BMD. The bone marrow fat/BMD ratio is a significant diagnostic indicator of bone weakening.

Absorptiometry, Photon↗
PubMed2004

Overexpression of c-met in oral SCC promotes hepatocyte growth factor-induced disruption of cadherin junctions and invasion.

Hepatocyte growth factor (HGF), the ligand for the c-met proto-oncogene product, is a multifunctional protein that enhances tumor cell motility, extracellular matrix invasion, and mitogenic or morphogenic activities of various cell types. In this study we examined the expression of the c-Met receptor in human oral squamous cell carcinoma (SCC) in vivo and in vitro to explore its relationship to tumor progression and invasiveness. Biopsy specimens of human oral SCC were immunohistochemically stained for c-Met. Nearly all primary oral SCC lesions and lymph node metastases consistently showed intense staining for c-Met, whereas normal oral mucosa showed faint to negative staining only on basal cells. In a panel of human oral SCC cell lines, we found a strong correlation between the levels of c-Met expression and the cells' response to HGF in motility and invasion assays. Sensitivity to HGF also correlated with the expression of the c-Met 9-kb mRNA. When the non-invasive HOC-605 cell line, which expresses a low level of c-Met receptor, was transfected with an expression plasmid containing human c-met cDNA, the transfectant cells showed motile and invasive responses to HGF. Immunostaining and immunoprecipitation studies demonstrated that E-cadherin and c-Met were physically associated at SCC cell-cell junctions, suggesting a direct role for c-Met in induction of junctional integrity. Importantly, HGF caused a rapid elevation of unbound beta-catenin, suggesting its availability for nuclear signal transduction and triggering of cell motility and invasiveness. Thus, overexpression of c-Met may facilitate disruption of E-cadherin junctions. Collectively, these results suggest that HGF/c-Met signaling is a common event in oral SCC that may trigger phenotype modulation and enhanced invasion and metastasis.

Blotting, Northern↗
PubMed2003

Involvement of the terminus of grouper betanodavirus capsid protein in virus-like particle assembly.

Dragon grouper, Epinephelus lanceolatus, nervous necrosis virus (DGNNV) consists of 180 copies of capsid protein that encapsulates a bipartite genome of single-stranded (+)RNAs. Expressing the open reading frame (ORF) of RNA2 in Escherichia coli forms virus-like particles (VLPs) that resembles native virus. Deleting N- and C-termini revealed different impacts on VLP formation. Deletion of 35 or 52 residues at the N-terminus completely ruined the VLP assembly, presumably due to removal of positively charged residues for binding RNAs. When deletions were restricted to 4, 16, or 25 N-terminal residues, the assembly of VLPs remained. The ability of VLP formation diminished when 4 to 11 C-terminal residues were deleted. The termini that can be deleted without seriously destructing the VLPs are 25 and 3 residues at N- and C-termini, respectively.

Amino Acid Sequence↗
PubMed2003

Structural and biochemical evidence of mitochondrial depletion in pigs with hypertrophic cardiomyopathy.

Pig hearts with naturally occurring hypertrophic cardiomyopathy (HCM) were isolated to investigate the effects of mitochondrial deficiency at biochemical and molecular levels. Enzyme activities of mitochondrial-encoded cytochrome c oxidase and NADH dehydrogenase in the HCM hearts (n=12) were lower than that in the controls (n=12) by 41+/-29% (P<0.01) and 43+/-21% (P<0.001), respectively. Additionally, Southern blot analysis was conducted to quantify the relative amount of mitochondrial DNA (mtDNA) from the HCM and controls. The relative amount of mtDNA in the HCM hearts was significantly 57+/-19% (P<0.001) lower than that in the controls. Both mitochondrial enzyme deficiency and mtDNA depletion were significantly correlated with the degree of cardiac hypertrophy judged based on the ratio of heart/body weight. In conclusion, our results reveal that a secondary effect of tissue-specific mtDNA depletion and mitochondrial dysfunction is in response to the HCM.

Animals↗
PubMed2003

Biotransformation of cyanide to methane and ammonia by Klebsiella oxytoca.

Klebsiella oxytoca, isolated from cyanide-containing industrial wastewater, was shown to be able to biodegrade cyanide to non-toxic endproducts using cyanide as the sole nitrogen source. In this study, ammonia was one of the detected endproduct of cyanide biodegradation by the concentrated resting cells of K. oxytoca. Moreover, cyanide has been shown to be biotransformed to methane through the actions of concentrated resting cells. Biodegradation of cyanide by cell-free extracts was not observed, which might be due to the inactivation of nitrogenase (an oxygen-labial enzyme) caused by the oxygen exposure after cell disruption. Results show that the cyanide consumption by resting cells of K. oxytoca was induced when the pretreatment of these cells with cyanide was conducted. However, the cyanide-degrading capability of resting cells pretreated with ammonia was inhibited. The inhibition of cyanide degradation by resting cells of K. oxytoca was affected by the ammonia concentration. This might result from the suppression of nitrogenase activity of K. oxytoca by ammonia since nitrogenase was suggested to be the sole cyanide-degrading enzyme during the cyanide degradation process. Results from this study also show that the processes of cyanide biodegradation and ammonia production by resting cells occurred simultaneously. This suggests that the utilization of cyanide as nitrogen source by K. oxytoca might proceed using ammonia as an assimilatory substrate.

Ammonia↗
PubMed2003

Effects of glucose concentration on in vitro fertilization in BALB/c mice.

BALB/c mice are widely used in genetic, tumour and immunological studies. However, the mice demonstrate a lower reproduction rate, low fertility and small litters, because of their highly genetic homozygoisty. Based on in vitro fertilization (IVF), a routine technique for biomedical studies, it is worth to evaluate the effects to BALB/c mice on IVF efficiency. In order to test the genetic factor affecting the IVF efficiency of BALB/c, four reciprocal IVF tests of BALB/cByJ and FVB/NCrl mice were performed. The results showed that the average fertility of IVF sponsored by FVB/NCrl spermatozoa was 69.6%, but only 12.1% was obtained from BALB/cByJ strain. Effect of glucose contained in the culture medium to the IVF efficiency of BALB/cByJ was also evaluated. The results showed that the fertility of BALB/cByJ spermatozoa incubated with 0, 2.7, 5.5, 11.1 and 22.2 mm of glucose in the TYH medium were 6.8, 9.9, 13.9, 32.7 and 22.2%, respectively. It is showed that IVF efficiency of BALB/cByJ spermatozoa could be improved depending on the concentration of glucose in the IVF medium. According to the results, it is beleived that lower IVF of BALB/cByJ mice might be due to the genetic defect in spermatozoa and increasing glucose in the IVF medium which significantly affect the IVF efficiency of BALB/cByl via activating the spermatozoa.

Animals↗
PubMed2003

The effect of vascular endothelial growth factor and brain-derived neurotrophic factor on cavernosal nerve regeneration in a nerve-crush rat model.

OBJECTIVE: To test the hypothesis that an intracavernosal injection with brain-derived neurotrophin factor (BDNF) and vascular endothelial growth factor (VEGF) can facilitate nerve regeneration and recovery of erectile function after cavernosal nerve injury. MATERIALS AND METHODS: The study included 25 Sprague-Dawley rats; four had a sham operation, seven bilateral nerve crushing with no further intervention, and 14 bilateral nerve crushing with either an immediate (seven) or delayed for 1 month (seven) intracavernosal injection with BDNF+VEGF. Erectile function was assessed by cavernosal nerve electrostimulation at 3 months, and neural regeneration by NADPH-diaphorase staining and tyrosine hydroxylase (TH) staining of penile tissue and major pelvic ganglia (MPG). RESULTS: After nerve crushing, the functional evaluation at 3 months showed a lower mean (SD) intracavernosal pressure (ICP) with cavernosal nerve stimulation, at 33.9 (15.3) cmH2O, than in the sham group, at 107.8 (18.1) cmH2O. With an immediate injection with BDNF+VEGF the ICP was significantly higher than in the controls, at 67.8 (38.5) cmH2O. Even delayed injection with BDNF+VEGF improved the ICP, to 78.0 (21.8) cmH2O. Histological analysis of specimens stained for NADPH and TH showed a significant change in the morphology of terminal branches of the cavernosal and dorsal nerves, and the staining quality of the neurones in the MPG. The number of positively stained nerve fibres tended to revert to normal after treatment with BDNF+VEGF. CONCLUSION: An intracavernosal injection with BDNF+VEGF appears to both prevent degeneration and facilitate regeneration of neurones containing neuronal nitric oxide synthase in the MPG, dorsal nerve and intracavernosal tissue. Therefore it might have therapeutic potential for enhancing the recovery of erectile function after radical pelvic surgery.

Animals↗