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Biomedical subjects

D S Hsieh

Publications and source records attributed to D S Hsieh.

15 recordsLinked to original sources
PubMed2001

Detection of chromosomal alterations in bladder cancer by comparative genomic hybridization.

OBJECTIVES: To characterize which genomic alterations occur in bladder cancers of different grades and stages, and to evaluate the prognostic implication of chromosomal imbalances. Materials and methods Twelve transitional cell carcinoma cell lines were used to study chromosomal aberrations, using comparative genomic hybridization to examine metaphase cells. RESULTS: There was a mean of 6.0 aberrations per tumour with 4.9 gains and 1.08 deletions per tumour cell line. The mean number of aberrations was the same in grade 2 and 3 tumours. High-stage (>/= T2) carcinomas had markedly more genomic gains than had low-stage (T1) tumours, with 7.2 gains and 1.3 deletions per >/= T2 tumour, and 2.7 gains and 0.8 deletions per T1 tumour, although the difference was not statistically significant. The most frequent changes were gains of chromosome 1 (seven), 9 and 16 (six), and losses of chromosomes 14 (three), 21 and Y (two). The changes 1p+, 3p+, 9q+, 14p-, 16q+ and Yp- were significantly more frequent in low-grade tumours, with 1p+, 3p+ and Yq- the most frequent in stage T1 tumours, and 16p+, 9q+ and 13q- the most frequent in stage >/= T2 tumours. Conclusion These findings indicate several genomic regions in chromosomes 1, 9, 14 and 16 that may carry genes for the development and progression of bladder cancers.

Carcinoma, Transitional Cell↗
PubMed2001

The expression of neuropeptides in hyperplastic and malignant prostate tissue and its possible clinical implications.

PURPOSE: We characterized the incidence and pattern of distribution of neuroendocrine differentiated tumor cells in prostatic hyperplastic and carcinomatous tissue, correlated neuroendocrine differentiation with prostate specific antigen (PSA) and assessed whether neuroendocrine cells have value as an independent indicator of poor prognosis in patients with prostate carcinoma. MATERIALS AND METHODS: We immunohistochemically evaluated hyperplastic and carcinomatous prostate specimens for chromogranin A, neuron specific enolase and serotonin expressing tumor cells. The expression of various markers in cells was analyzed and correlated with tumor DNA ploidy, disease grade and stage, PSA and clinical course in patients with prostate cancer. RESULTS: Enrolled in our study were 31 patients with hyperplastic prostate tissue and 30 with prostatic carcinoma. Followup in cancer cases was 1 to 9 years (mean 3.7). During followup 9 patients (30%) died of cancer. We noted DNA content aneuploidy in 5 cases (16.7%) of prostate carcinoma. Chromogranin A, neuron specific enolase and serotonin were expressed in 80%, 43% and 77% of cases of prostate carcinoma and in 29%, 10% and 36% of hyperplastic tissue, respectively. Larger prostates had no higher content of various neuroendocrine cells than smaller prostates. There was higher expression of neuropeptides in carcinomatous than in hyperplastic tissue. Of the 3 peptides chromogranin A was significantly related to all parameters, including Gleason score, tumor stage, PSA and patient survival. In addition to PSA, neuron specific enolase was also closely associated with other clinicopathological parameters. Serotonin was significantly related to patient survival only but we noted no correlation with Gleason score, tumor stage or PSA. In regard to factors predictive of patient prognosis expression of the 3 neuropeptides in tumor cells, Gleason score, tumor stage and PSA were closely related to patient survival in this study CONCLUSIONS: The growth of hyperplastic prostate tissue is related to neuroendocrine cell activity. The chromogranin A marker has the highest expression in prostate cancer. Neuroendocrine cells may represent an independent indicator of poor prognosis in patients with prostate carcinoma.

Aged↗
PubMed1998

Bilateral idiopathic infantile pyoceles: a case report.

A 15-day-old infant was admitted to the 803 Military Hospital with swelling, bilateral erythematous changes, a tender firm mass in the scrotum and fever of six hours' duration. Scrotal sonography showed accumulated fluid with internal echoes in both hydrocele sacs. Aspirated fluid was found to contain Escherichia coli and bilateral scrotal pyoceles was diagnosed. The most common etiologic factor for this is meconium peritonitis, with surgical drainage being the necessary treatment. The case is reported, with a review of the literature.

Escherichia coli Infections↗
PubMed1995

Self-introduction of unusual foreign body into the urethra: a case report.

An 89-year-old male developed chronic urinary retention for five days due to a lobster tentacle impacted in his penile urethra. Because the penile deformity and abscess formation, he received external urethrotomy with removal of foreign body and suprapubic urinary diversion. There was no psychiatric problem in this patient.

Aged↗
PubMed1983

Zero-order controlled-release polymer matrices for micro- and macromolecules.

Theoretical and experimental analyses demonstrate that a hemispheric polymer-drug matrix laminated with an impermeable coating, except for an exposed cavity in the center face, can be used to achieve zero-order release kinetics. Hemispheric systems for low molecular weight drugs were prepared by heating and compressing polyethylene and drug (sodium salicylate) in a brass mold. Hemispheric systems for high molecular weight drugs were prepared by casting ethylene-vinyl acetate copolymer and protein in a hemispheric mold at -80 degrees, followed by a two-step drying procedure (-20 and 20 degrees). In both systems, cavities were made in the center face of the hemispheres and the remainder of the matrices coated with an impermeable material. Zero-order release for 60 days at a rate of 0.5 mg/day was achieved from polymer matrices containing bovine serum albumin (mol. wt. 68,000).

Chemistry, Pharmaceutical↗
PubMed1982

Synthesis of low-phenylalanine polypeptides.

Low-phenylalanine-peptides for dietotherapy of phenylketonuria (PKU) were prepared from soybean protein isolate. Soluble fraction of soybean protein isolate was hydrolysed by alpha-chymotrypsin then followed by carboxypeptidase-A. Molecular weight distribution and amino acid analysis were made on the resultant polypeptides. The chymotrypsin hydrolysate was divided into two fractions, Fraction I (molecular weight greater than 2500) and Fraction II (molecular weight between 1000 and 2500). The phenylalanine content of Fraction I (3.1%) was lower than that of Fraction II (5%), indicating the nonuniform distribution of phenylalanine in soy bean protein. Carboxypeptidase hydrolysis of Fraction I further reduced the phenylalanine concentration to 2.3%, approximately half of the original concentration in soybean protein isolate.

Amino Acids↗
PubMed1981

Inhibition of tumor growth, vascularization, and collagenolysis in the rabbit cornea by medroxyprogesterone.

Medroxyprogesterone, dexamethasone, or cortisone, locally applied in sustained release polymer to rabbit V2 carcinoma implanted in the rabbit cornea, blocked neovascularization and three-dimensional growth of the tumor. These hormones similarly prevented the vascular proliferative response to implants in the rabbit cornea of mouse B-16 melanoma and also the response to implants of polymer containing tumor extract with angiogenesis activity. The inhibitory responses were accompanied by considerable reduction in collagenolytic activity released into culture medium by explants of the two tumors and of the corneal region containing angiogenic hepatoma extract. Morphologic studies revealed extensive three-dimensional disruption of the compact laminated collagenous structure of the cornea by untreated V2 carcinoma. In the presence of hormone the tumor grew slowly as a noninvasive two-dimensional plaque limited to the narrow region of the insertion pocket in the cornea, with no obvious disturbance of structure elsewhere. Cortisone was much les effective than medroxyprogesterone or dexamethasone. Testosterone and estradiol had no effect on the three measured properties. The data suggest that local hormonal interference with neovascularization, collagenase production, and tumor growth can prevent neoplastic invasion and destruction of a dense collagenous connective tissue.

Animals↗
PubMed1981

Magnetic modulation of release of macromolecules from polymers.

Sustained-release systems were made by incorporating bovine serum albumin and magnetic steel beads in an ethylene-vinyl acetate copolymer matrix. When exposed to aqueous medium, the polymer matrix released the albumin slowly and continuously. Application of an oscillating magnetic field increased the release rate by as much as 100%. Intervals of 6-hr periods of magnetic exposure and nonexposure were alternated over a 5-day period, resulting in corresponding increases and decreases in release and establishing a pattern of modulated sustained release.

Animals↗
PubMed1980

Polymers for sustained macromolecule release: procedures to fabricate reproducible delivery systems and control release kinetics.

Matrixes composed of ethylene-vinyl acetate copolymer are useful vehicles for the sustained release of macromolecules such as proteins. A new procedure for fabricating these polymeric delivery systems involved mixing the dry, powdered macromolecule with a polymer solution and casting the mixture at -80 degrees. The resulting matrix was dried in two 48-hr stages, first at -20 degress and then at 20 degrees. These polymer systems had uniform drug distribution, and their release kinetics were reproducible. Fabrication parameters such as drug particle size, drug loading, and matrix coating all significantly affected release kinetics.

Animals↗
PubMedDate not supplied

Modulation of MDR-1 gene by MIF and GSTpi with drug resistance generation in hormone independent prostate cancer.

The expression of MIF and GSTpi were upregulated in prostate cancer cells with mulitdrug resistant phenotype. The aim of this study is to determine the relationship between these genes and multidrug resistance (mdr-1) gene in acquired multidrug resistance of prostate cancer. The expression of MIF, GSTpi and gp-170 in multidrug resistant (MDR) subline or native cells were determined using flow cytometry and western blotting. The mRNA level of various genes was analyzed with RT-PCR method. The chemosensitivity of tumor cells and stable transfectants to paclitaxel was measured using MTT (tetrazolium bromide) assay. The protein levels of MIF, GSTpi and gp-170 increased in MDR sublines of prostate cancer when compared with their parental cells. The MIF and GSTpi stable transfectants expressed higher MIF and GSTpi protein levels than their parental cells in western blotting analysis, respectively. The expression of mdr-1 gene and the production of pg-170 were also increased in either MIF or GSTpi stable transfectants when compared with vector control by using RT-PCR and flow cytometric analysis. The MTT results demonstrated that the increased chemoresistance was correlated with the increased production of gp-170 protein in either MIF or GSTpi transfectants. The upregulation of MIF and GSTpi during the development of acquired drug resistance of hormone independent prostate cancer may simultaneously and partially modulate the activation of gp-170.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Increasing expression of GST-pi MIF, and ID1 genes in chemoresistant prostate cancer cells.

The differential expression of genes and related proteins of multidrug resistance in chemoresistant prostate cancer cell lines were elucidated in this study. RNA extracted from doxorubicin-resistant rat prostate cancer (PCa) cells (AT3/ADR1000) and native PCa cells was hybridized to expression arrays containing cDNAs from 588 known genes. Differential expression of selected genes was confirmed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis. Protein contents were measured by fluorescent flow cytometry and immunoblotting. Localization of selected proteins in cells was observed by immunocytochemical staining. Up-regulation of eleven genes and down-regulation of one single gene were displayed in the chemoresistant prostate cancer cells. Overexpression of mRNAs in macrophage migration inhibitory factor (MIF), DNA binding protein inhibitor 1 (ID1), and glutathione S-transferase-pi (GST-pi) were confirmed by gene-specific RT-PCR. Protein over-expression of GST-pi, MIF, and ID1 in resistant cells were 3.3-, 1.5-, and 1.5-fold to native cells, respectively. Immunocytochemistry revealed that GST-pi, MIF, and ID1 were present primarily in the cytoplasm of tumor cells, but ID1 also could be found in the nucleus. AT3/ADR1000 drug-resistant PCa cells displayed significantly increased expression of GST-pi, MIF, and ID1 proteins when compared with native PCa cells. It indicates these genes may play a role in drug resistance of prostate cancer.

Animals↗
PubMedDate not supplied

Redistribution of androgen receptors in acquired hormone-refractory prostate cancer cells.

The dynamic translocation of androgen receptors (ARs) in prostate cancer cells after hormone conversion was studied. The prostate cancer cell line LNCaP was converted into androgen-independent sublines after long-term treatment with 5alpha-reductase inhibitor and steroid-depleted medium. Immunohistochemical, immunofluorescent staining and laser scanning microscopy were used to observe the redistribution and serial translocation of ARs in these tumor cells. The androgen-independent tumor cells (LNCaP/Fin and LNCaP/HR) grew slower than native cells with fibroblastic-like characteristics. On immunohistochemical and immunofluorescent double staining, translocation and exocytosis of ARs were noted in androgen- independent tumor cells much more markedly than in native cells. Furthermore, laser-scanning microscopy revealed serial image changes of AR vesicle shifting and exocytosis in androgen-converted tumor cells. Translocation and exocytosis processes were observed in androgen-independent prostate cancer cells. ARs lose partly normal cellular biologic role during hormone manipulation.

Antineoplastic Agents↗
PubMedDate not supplied

Permeation enhancers compatible with transdermal drug delivery systems. Part I: selection and formulation considerations.

Part I of this article reviews the classification, chemistry, properties, selection, and use of skin permeation enhancers in transdermal drug delivery systems and dermal patches. The authors discuss ideal properties of enhancers and describe various enhancers' actions on the skin. Part II will describe interactions between permeation enhancers and other transdermal delivery system components, such as backing materials, pressure-sensitive adhesives, membranes, and release liners. Adhesive properties critical to the optimization of a transdermal formulation will be discussed.

Adjuvants, Pharmaceutic↗
PubMedDate not supplied

Permeation enhancers compatible with transdermal drug delivery systems: part II: system design considerations.

Part I of this article reviewed the classification, chemistry, properties, selection, and use of skin permeation enhancers in transdermal drug delivery systems and dermal patches. In Part II, the authors discuss ideal properties of enhancers and describe various enhancers' actions on the skin, as well as interaction among permeation enhancers and other transdermal delivery system components, such as backing materials, pressure-sensitive adhesives, membranes, and release liners. Adhesive properties critical to the optimization of a transdermal formulation are discussed.

Adjuvants, Pharmaceutic↗