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Biomedical subjects

C S Liu

Publications and source records attributed to C S Liu.

At least 37 records · Page 2Linked to original sources

University students' attitudes towards mental patients and psychiatric treatment.

BACKGROUND: Public attitudes towards mental patients and psychiatric treatment are mostly unfavorable. Mental patients tend to conceal their illness or selectively disclose their treatment histories to someone they trust. AIMS: To examine the university students' attitudes towards different information regarding a person labeled as mentally ill. METHODS: We designed seven descriptions of a mentally ill person of varying past and current treatment histories and randomly assigned 308 university undergraduates to read one of the descriptions. Subjects rated their willingness to interact with the hypothetical case using a 19-item social distance scale. RESULTS: Greater social distance was associated with non-medical field of study, no previous contact with the mentally ill and female gender. Subjects without previous contact with mentally ill individuals kept greater distance from a discharged mental patient receiving psychiatric care than a mental patient who did not require medications nor psychiatric follow-up. In contrast, respondents who had previous contact with the mentally ill were more willing to interact with a discharged mental patient receiving psychiatric care comparing with a person labeled as mentally ill alone and a mental patient who had never been admitted to hospital. CONCLUSIONS: Implications of our findings in clinical management and designing stigma-reducing programme are discussed.

Adult↗

Self-focusing and frequency broadening of an intense short-pulse laser in plasmas.

An intense ultrafast laser pulse propagating through a plasma undergoes self-focusing and self-phase-modulation as a result of relativistic mass nonlinearity. The inclusion of a quartic (r4) term in the expansion of the eikonal in the radial coordinate r allows the modification of the shape of the radial intensity profile. The front of the pulse, under the combined effects of time-dependent self-focusing and frequency downshifting, acquires a severely distorted temporal shape. The radial profile for I(lambda)2(mu) < 2.8 x 1018 W/cm2, where I is the axial laser intensity and lambda(mu), is the laser wavelength in micrometers, is transformed from a Gaussian to a super-Gaussian because of the faster convergence of the marginal rays than the paraxial rays. In the opposite case of I(lambda)(2)(mu) > 2.8 x 10(18) W/cm2 when nonlinear plasma permittivity approaches saturation, the radial profile in the axial region becomes broader than the Gaussian.

Journal Article↗

Expression of HER-2/NEU oncoprotein in familial and non-familial breast cancer.

The HER-2/neu proto-oncogene amplification or oncoprotein overexpression is an important prognostic factor and a predictive factor for resistance to endocrine therapy and adjuvant chemotherapy in breast cancers. Moreover, it is an entry criterion in the assessment of patients for whom Herceptin (Trastuzumab) treatment is considered. The overexpression rate of HER-2/neu oncoprotein has been identified in 10% to 40% of human breast cancers. In Taiwan, a higher grade of pathobiologic characteristics of familial breast cancer was also noted than that found in the non-familial group. It is worthwhile to evaluate whether the overexpression is more frequent in familial breast cancers. Fifty-six familial and 111 non-familial breast cancers were studied between 1990 and 1999 to assess both the overexpression of HER-2/neu oncoprotein immunohistochemically and the correlation with the histological type, grade and stage of breast carcinoma. The overexpression rate is higher in the familial breast cancer group (50.0%) when compared with non-familial breast cancer group (36.9%), which did not prove to be statistically significant (P = 0.1068). However, when the infiltrating ductal carcinomas of both groups are compared, it is statistically significant (52.3% vs. 33.7%, P = 0.0429). Overexpression correlated with node status and histological grade of infiltrating ductal carcinomas in non-familial and overall breast cancers. It also correlated with nuclear pleomorphism and mitotic counts, but not tubule formation or tumor size. All 3 cases of Paget's disease revealed overexpression, whereas all 12 cases of mucinous and one case of metaplastic carcinoma and one case of medullary carcinoma were negative. The overexpression rate was higher both in familial and non-familial intraductal carcinomas (57.1% vs. 73.3%, P = 0.4716). No statistical difference was identified between the 2 subsets. A case of infiltrating ductal carcinoma combined with intraductal carcinoma revealed heterogeneous staining in the component of ductal carcinoma in situ, while the invasive component did not. This suggests that overexpression decreases within individual tumors as they evolve from in situ to invasive lesioins. The HER-2/neu may imply a different role in intraductal carcinoma, Paget's disease and invasive duct carcinoma. Although the overexpression rate of HER-2/neu oncoprotein of familial breast cancer was not significantly higher than that of the non-familial group, it is appropriate to evaluate the rate of HER-2/neu overexpression according to the histological type of breast cancers from familial breast cancer and non-familial breast cancer. The prognoses will be needed for future evaluation.

Breast Neoplasms↗

The growth effects of gamma-ray irradiation on third-stage larvae of Angiostrongylus cantonensis in snail.

In order to clarify growth effects of gamma-ray irradiation on the third-stage larvae of Angiostrongylus cantonensis, snails naturally infected with larvae of A. cantonensis were irradiated with a cobalt-60 source, and the total dosage of exposure was 0.1 kGy. Third-stage larvae were collected from each group of irradiated and non-irradiated snails and then administered to rats. A significant reduction was observed in the number of recovery worms from rats sacrificed at 45 days after infection compared with the control group. Moreover, there was an increase in the percentage of female worms, and the body length of the irradiated group's worms was significantly shorter than that of the control group. In ultrastructural observations by transmission electron microscope, the cuticle was thickened and the subcuticle showed partial vacuolization and separation from muscle in the irradiated group. In addition, the muscles myofibril became shorter, the microvilli of intestinal mucosa were shorter and irregular, the terminal web disappeared, and the phagocytic vesicles, mitochondria, lysosomes and secretion granules decreased in number, respectively. Focusing on the mitochondria of the epithelial cells of the intestine, there were degenerative changes in the irradiated group showing vacuolization. The gonads of female worms recovered from the irradiated group revealed degenerative vacuolization, and the gonads of male worms could not be found.

Angiostrongylus cantonensis↗

Diagnosis of Helicobacter pylori infection by stool antigen test in southern Taiwan.

Helicobacter pylori (H. pylori) has been found to be associated with various gastrointestinal diseases. Confirmation of H. pylori infection includes invasive and non-invasive methods. There has been increasing interest in noninvasive tests recently. However, the geographical differences among H. pylori strains have been emphasized recently and the H. pylori strain in Taiwan showed a high cagA positive result and different vacA subtype when compared with those of Western countries. The aim of this study is to access and compare the reliability and the diagnostic accuracy of the stool H. pylori antigen tests by spectrophotometry and by the visual method, especially in Southern Taiwan. Thirty-two patients (18 men and 14 women; age range: 23-91 y/o, mean: 50.5 y/o) who underwent gastroendoscopy at Kaohsiung Medical University Hospital were enrolled in this study. H. pylori infection status was confirmed by culture or two positive test results on CLO test, histology and 13C-urea breath test (13C-UBT). The exclusion criteria included previous gastrointestinal tract surgery, use of antibiotics, proton pump inhibitor or compounds containing bismuth within 1 month of the study. Among them, 14 patients were with duodenal ulcer (DU), 4 with gastric ulcer (GU), 12 with non-ulcer dyspepsia, and 2 with GU and DU. Those patients had their stool collected for ELISA tests of H. pylori stool antigen (HpSA). The HpSA tests were positive in 16 of 18 patients diagnosed as H. pylori positive, and negative in 13 of 14 patients as H. pylori negative. The sensitivity and specificity were 88.9% and 92.9% respectively. The positive and negative predictive values were 94.1% and 86.7% respectively. The concordance of HpSA accessed by spectrophotometry and visual method is 100%, which makes this test even easier and cheaper. We concluded that stool HpSA test is a noninvasive, accurate, reliable, rapid and easy way to diagnose H. pylori infection in Southern Taiwan, either by spectrophotometry or by visual assessment.

Adult↗

Hepatic Schistosomiasis japonica in a patient with gallstones and bile duct stones--a case report.

Schistosomiasis, a common parasitic disease in many countries, is found as imported cases in Taiwan. Responsible for human infections are five species, one of which, Schistosoma japonicum, is currently endemic in China and South-east Asia. Chronic infection with S. japonicum may lead to the development of liver fibrosis, calcification and portal hypertension. Under investigation by sonography and computed tomography (CT) scan, a peculiar "turtle-back" appearance of liver fibrosis and calcification may be found. Herein, we report a case referred to our department due to jaundice. The sonography of liver showed typical "turtle-back" appearance. Gallstones and bile duct stones were also found in this case. Surgical interventions with percutaneous transhepatic biliary drainage (PTBD), cholecystectomy and choledocholithotomy were performed to relieve the obstructive jaundice and remove the stones. There were no parasitic eggs in the extracted stones or in drained bile juice. However, deposits of calcified S. japonicum eggs in liver parenchyma and portal tracts were identified in liver biopsy. No special treatment was given for the schistosomiasis japonica because the calcified parasitic eggs were the sequelae of past infection.

Aged↗

Distribution of enantiomers of trans-tramadol and trans-O-demethyltramadol in central nervous system of rats.

AIM: To investigate the distribution of the enantiomers of trans-tramadol (trans-T) and its active metabolite, trans-O-demethyltramadol (M1), in the central nervous system (CNS). METHODS: After a single ip dose of trans-T hydrochloride or M1, the rats were killed by decapitation. A high performance capillary electrophoresis (HPCE) method was used to determine the concentrations of enantiomers of trans-T and M1 in the serum and different brain tissues, including cerebrospinal fluid (CF), cerebral cortex (CC), corpus striatum (CS), hypothalamus (HY), cerebellum (CE), and medulla oblongata (MO). RESULTS: After ip trans-T hydrochloride, the concentrations of (+)-trans-T were higher than those of (-)-trans-T in the serum and all tested brain tissues; The concentrations of (+)-M1 were lower than those of (-)-M1 in the all tested brain tissues; The concentrations of the enantiomers of trans-T and M1 were the highest in the CC, the lowest in the CF. After ip M1, the concentrations of (+)-M1 were higher than those of (-)-M1 in the serum and all tested brain tissues; The concentrations of the enantiomers of M1 were the highest in the CC, the lowest in the CF. CONCLUSION: The concentrations of the enantiomers of trans-T and M1 varied in the serum and different brain tissues. The distribution of trans-T and M1 in the CNS of rats was stereoselective. The stereoselectivity in the distribution of M1 after M1 injection was different with that after trans-T injection.

Animals↗

[Study on high-efficiency gene transfer of pseudotyped HIV vector].

OBJECTIVE: To investigate the high-efficiency of pseudotyped HIV as gene transfer vector. METHODS: Three plasmids of pseudotyped HIV gene transfer vector system were transferred into packaging cell line 293T by Ca3 (PO4)2 precipitation method. GFP (Green Fluorescence Protein) or HSV-tk gene was constructed in the plasmid pHR'CS respectively (pHR'CS.GFP or pHR'CS.HSV-tk). The pseudotyped HIV particles were observed through electronic microscopy and were measured through spectrofluorophotometer. High titer pseudotyped HIV was harvested from volume of virus-producing cell supernatant and concentrated. Ovarian epithelial cancer cell line SKOV3 and normal human gingival fibroblast cell GF were infected by pseudotyped HIV. PCR and RT-PCR were resorted to demonstrate the successful transduction and transcription of the HSV-tk gene. After administration of GCV, the changes of those cells and apoptosis were observed through optical microscopy. The cytotoxicity efficacy of HSV-tk/GCV system was evaluated by MTT method. The growth inhibition rate (GIR) of cells and inhibition concentration 50 (IC50) were counted. RESULTS: The above plasmids were effectively transferred into 293T cell. A lot of pseudotyped HIV particles were observed through electronic microscopy. The virus supernatant had a high absorbing value at 510 nm through spectrofluorophotometer, which proved the existence of virus. After pseudotyped HIV infection, SKOV3 and GF had remarkable infection rate. 600 bp strand was seen through PCR and RT-PCR. Changes and apoptosis of cells followed by administration of GCV were observed. The MTT method showed that the cytotoxicity efficacy of GCV was high to SKOV3 and GF cell. CONCLUSIONS: The pseudotyped HIV is a high-efficiency gene transfer vector.

Cell Line, Tumor↗

[Study on the interaction between sparfloxacin and serum albumins by fluorescence].

The binding reaction between sparfloxacion (SPFX) and bovine serum albumin (BSA) or chicken egg albumin (CEA) in aqueous was studied using fluorescence and absorption spectra. Their binding constants are KCEA = 8.29 x 10(6) and KBSA = 4.41 x 10(7), and the binding sites are nCEA = 0.558, nBSA = 0.793 respectively. The action distances (RCEA = 1.99 nm, RBSA = 2.09 nm) and energy transfer efficiencies (ECEA = 0.766, EBSA = 0.714) between donor-acceptor and SPFX were obtained by Förster's nonradiative energy transfer mechanism. The experiment demonstrated that the higher the temperature is, the lower the slopes of quenching curves of BSA and CEA are in presence of different amounts of SPFX. It is confirmed that the combination for SPFX with BSA or CEA is a single static quenching process, their interaction may be interpreted with energy transfer mechanism. Through binding reaction of the two albumins with SPFX, the biological effects and action mechanism of SPFX with albumins in vivo were discussed.

Albumins↗

Autoantibody against oxidized low-density lipoproteins may be enhanced by cigarette smoking.

A total of 59 healthy male subjects (32 smokers and 27 nonsmokers) who had no reported systemic disease and did not take alcohol and vitamin supplementation were included. The levels of autoantibody to oxidized low-density lipoproteins (ox-LDL) in smokers and age-matched nonsmokers were compared. The plasma levels of antioxidants that can affect the formation of ox-LDL were also measured, and correlation analyses between anti ox-LDL IgG and plasma antioxidants, controlling for age and body mass index (BMI), were performed. Plasma alpha-tocopherol and uric acid concentrations of nonsmokers (2.78+/-1.09 microg/mg total lipid and 6.96+/-1.69 mg/dl, respectively) were significantly higher than those of smokers (1.68+/-0.48 microg/mg total lipid and 6.15+/-1.14 mg/dl, respectively) (P<0.05). Although plasma ascorbate and retinol levels were not significantly different between smokers and nonsmokers, smokers older than 45 years old had significantly lower plasma ascorbate levels (0.32+/-0.17 mg/dl) than age-matched nonsmokers (0. 53+/-0.14 mg/dl) (P=0.036). Higher level of plasma anti ox-LDL IgG was noted in the group of smokers compared with nonsmokers (515+/-409 mU/ml vs. 407+/-268 mU/ml, respectively) under the statistic method of Chi-Square test (P=0.049). A significant negative correlation was found between plasma anti ox-LDL IgG and alpha-tocopherol in the combined population as well as in the smoker group (r=-0.26, p=0.047; r=-0.48, p=0.006; respectively). However, there was no correlation between plasma anti ox-LDL IgG and the levels of other antioxidants. These results suggest that reduced concentrations of alpha-tocopherol are associated with cigarette smoking. The significantly negative correlation between plasma anti ox-LDL IgG and alpha-tocopherol in the entire study population as well as in the smoker group suggests that plasma alpha-tocopherol may be partially effective if not totally at protecting LDL from oxidative damage caused by cigarette smoking and dietary supplementation with alpha-tocopherol may provide a protective effect against LDL oxidation, especially in smokers.

Adult↗

Optical cylinder designs to increase the field of vision in the osteo-odonto-keratoprosthesis.

BACKGROUND: The single optical cylinders used in the osteo-odonto-keratoprosthesis (OOKP) are known to produce very small visual fields. Values of 40 degrees are typically quoted. The purpose of this paper is to present designs for new optical cylinders that significantly increase the field of view and therefore improve the visual rehabilitation of patients having an OOKP. METHODS: Computer ray-tracing techniques were used to design and analyse improved one- and two-piece optical cylinders made from polymethyl methacrylate. All designs were required to have a potential visual acuity of 6/6 before consideration was given to the visual field and optimising off-axis image quality. Aspheric surfaces were used where this significantly improved off-axis image quality. RESULTS: Single optical cylinders, with increased posterior cylinder (intraocular) diameters, gave an increase in the theoretical visual field of 18% (from 76 degrees to 90 degrees) over current designs. Two-piece designs based on an inverted telephoto principle gave theoretical field angles over 120 degrees. Aspheric surfaces were shown to improve the off-axis image quality while maintaining a potential visual acuity of at least 6/6. This may well increase the measured visual field by improving the retinal illuminance off-axis. CONCLUSIONS: Results demonstrate that it is possible to significantly increase the theoretical maximum visual field through OOKP optical cylinders. Such designs will improve the visual rehabilitation of patients undergoing this procedure.

Computer-Aided Design↗

Flexible iris hooks for phacoemulsification in patients with iridoschisis.

Flexible iris hooks, or retractors, can be used to facilitate cataract removal by phacoemulsification in patients with primary iridoschisis. This rare condition is associated with fibrillary degeneration of the iris, narrow drainage angles, and cataract. In addition to their conventional use as iris retractors, iris hooks can control the degenerate fibrillary iris stroma to improve the view and access to the lens, preventing further damage during phacoemulsification and cortical cleanup. Iris hooks are widely available, easily handled, and can transform a difficult case into one that is almost routine.

Aged↗

Identification of novel human genes evolutionarily conserved in Caenorhabditis elegans by comparative proteomics.

Modern biomedical research greatly benefits from large-scale genome-sequencing projects ranging from studies of viruses, bacteria, and yeast to multicellular organisms, like Caenorhabditis elegans. Comparative genomic studies offer a vast array of prospects for identification and functional annotation of human ortholog genes. We presented a novel comparative proteomic approach for assembling human gene contigs and assisting gene discovery. The C. elegans proteome was used as an alignment template to assist in novel human gene identification from human EST nucleotide databases. Among the available 18,452 C. elegans protein sequences, our results indicate that at least 83% (15,344 sequences) of C. elegans proteome has human homologous genes, with 7,954 records of C. elegans proteins matching known human gene transcripts. Only 11% or less of C. elegans proteome contains nematode-specific genes. We found that the remaining 7,390 sequences might lead to discoveries of novel human genes, and over 150 putative full-length human gene transcripts were assembled upon further database analyses. [The sequence data described in this paper have been submitted to the

Amino Acid Sequence↗

Reproducibility of visual activation in functional MR imaging and effects of postprocessing.

BACKGROUND AND PURPOSE: Functional MR imaging studies of the brain should be interpreted in the context of their reproducibility. We assessed the reproducibility of visual activation measured by functional MR imaging and analyzed the effect of image transformation to standard space. METHODS: Seven healthy volunteers were studied twice with echo-planner functional MR imaging at 1.5 T during visual stimulation. The studies were separated by an interval of 2 to 7 days. Functional images were analyzed after spatial normalization to the space described by Talairach and Tournoux and/or after coregistration of the images of the second study with the images of the first study. The number of active voxels for each study was determined at three thresholds. In addition, the change in the center of the mass of activation, the mean change in signal intensity, and the mean t value within the activated area were measured. These reproducibility indexes were calculated for the spatially normalized and nonnormalized data for each subject. RESULTS: Variations in visual activation were observed between the two studies in the same individual as well as across subjects. There was no evidence of an effect from image transformation on reproducibility on any of the measures. CONCLUSION: Our findings show that the reproducibility of activation in functional MR imaging may be much more variable across subjects than suggested in previous studies. The use of different types of image transformation (coregistration, spatial normalization) does not significantly affect the reproducibility of visual activation.

Adult↗

Splice site mutation in the type VII collagen gene (COL7A1) in a Taiwanese family with recessive dystrophic epidermolysis bullosa.

BACKGROUND AND PURPOSE: Generalized recessive dystrophic epidermolysis bullosa (RDEB) is a severe inherited disease, in which patients suffer from blistering and scarring of the skin and mucous membranes after minor mechanical trauma. Tight genetic linkage has been established to the type VII collagen gene (COL7A1) at 3p21. The purpose of this study was to identify mutations in COL7A1 in one Taiwanese pedigree with generalized RDEB. METHODS: Genomic DNA was used as the template for polymerase chain reaction (PCR) amplification of all 118 COL7A1 exons and the flanking splice junctions. PCR was followed by heteroduplex analysis of the products by single-strand conformation polymorphism (SSCP) studies, and direct nucleotide sequencing was used to search for mutations, which were verified by restriction endonuclease digestion. RESULTS: We identified a homozygous intronic splice-site at the +1 position of intron 5 (682 + 1G-->A) of COL7A1 in the affected individual. His parents, who were cousins, were not affected by this disease. The mother was heterozygous for the mutation; the father had died before the study, of unrelated causes. This mutation results in a frameshift and downstream stop codons on both alleles, indicating an absence of functional protein. Restriction endonuclease BspHI can be used to verify this mutation and screen other members in the same family. CONCLUSIONS: These molecular findings offer a genetic explanation for the skin fragility in this Taiwanese patient with RDEB. The immediate benefits gained by elucidating mutations in family members include the ability to assess whether they are carriers of this disease and the ability to use this DNA-based method for prenatal testing in subsequent pregnancies.

Adult↗