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Biomedical subjects

S H Han

Publications and source records attributed to S H Han.

At least 217 records · Page 12Linked to original sources
PubMed1988

Assessment of HBV persistent infection in an adult population in Taiwan.

In order to study the prevalence of hepatitis B virus (HBV) in the adult population of Taiwan, we screened for the presence of HBV DNA in 205 blood samples from adult (20-59-year-old) volunteers. According to the serological markers of HBV, samples were divided into three groups: group I (173 subjects) was negative for both HBsAg and HBeAg; group II (14 subjects) was positive for both HBsAg and HBeAg; and group III consisted of 18 subjects who were HBsAg-positive but HBeAg-negative. Plasma HBV DNA was not detected in group I, but it was found in 85.7% and 11.8% of samples in group II and group III, respectively. A free-form HBV DNA was found in 14.3% of the leukocyte samples in group II. Furthermore, an integrated form of HBV DNA was detected in the leukocytes of two cases of group I who remained healthy based on clinical data. HBV DNA was also detected in the spermatozoa and liver cells of one of the cases.

Adult↗
PubMed1988

Establishment and characterization of a human urinary bladder carcinoma cell line (TSGH-8301).

A cell line derived from a well-differentiated human transitional cell carcinoma of the urinary bladder, designated TSGH-8301, was established in vitro. The cultured epithelioid cells exhibited monolayer growth and loss of contact inhibition. The tumorigenicity of TSGH-8301 had been shown by growth in soft agar and tumor induction in athymic nude mice. A reverse ratio of lactate dehydrogenase (LHD) isoenzyme in the cell line and nude mouse-grown tumors was seen predominantly with LDH-V. Chromosomal analysis revealed a heterodiploid stem line with a modal number of 50. Sera of urinary bladder cancer patients reacted with membrane antigens of the TSGH-8301 cells, suggesting the existence of tumor-associated antigens in the cells. In vitro chemosensitivity tests of these cells may provide data valuable in the selection of proper anticancer drugs for the TSGH-8301 donor patient.

Animals↗
PubMed1988

Establishment and characterization of a malignant glioma cell line, GBM8401/TSGH,NDMC.

A permanent human brain malignant glioma cell line, GBM8401/TSGH,NDMC, has been successfully established from a 31-year-old Chinese female with brain glioblastoma multiforme (GBM) in monolayer culture and has been subcultured for more than 100 passages during 24 months in vitro. The tumor cell doubling time in vitro was approximately 38 hr. The tumorigenicity in athymic nude mice was observed; the tumor volume doubling time was approximately 4 days. Glial fibrillary acidic protein (GFAP) and 10-nm-diameter intermediate filaments were identified by immunohistochemical peroxidase-antiperoxidase (PAP), immunofluorescence assay, and transmission electron microscopic methods. The scanning electron microscope revealed numerous surface microvilli and various-sized blebs. Karyotypic analysis showed this malignant glioma cell line to be of human origin, near-diploid with a modal chromosome number of 48,XX.

Adult↗
PubMed1988

The molecular basis of HbH disease in Taiwan.

We have determined the molecular characteristics of alpha-thalassemia in 12 HbH subjects from Taiwan by restriction endonuclease mapping with alpha- and zeta-specific probes. We have found four types of defects in the alpha-thalassemia-2 genetic determinant: -alpha 3.7 type I; -alpha 4.2; alpha CS alpha; and alpha alpha T. All HbH subjects carried the --SEA genotype in the alpha-thalassemia-1 determinant. At least two different subtypes of --SEA genotype were observed in this study.

DNA Restriction Enzymes↗
PubMed1988

Suppression of the growth of human colorectal carcinoma cells (LS174T) by radiolabeled monoclonal antibody (131I-MAbC27) in tissue culture and nude mice.

A monoclonal antibody against carcinoembryonic antigen (CEA), MAbC27, and its F(ab')2 fragments were prepared and labeled with 131I. They effectively suppressed the growth of a human colorectal carcinoma cell line, LS174T, both in culture medium and in inoculated nude mice, whereas 131I-labeled normal mouse immunoglobulin or 131I itself did not have similar effects. Intravenous injection of 131I-MAbC27 or 131I-MAbF(ab')2 following inoculation of carcinoma cells suppressed their growth in vivo. The suppression effect was even more effective when intact antibody rather than its F(ab')2 fragments was used, especially when the treatment was repeated. This study indicates that radiolabeled MAbC27 may be used as a therapeutic agent in CEA-secreting human colorectal carcinomas.

Animals↗
PubMed1988

Differential identification of Candida species and other yeasts by analysis of [35S]methionine-labeled polypeptide profiles.

This paper describes a scheme for differential identification of Candida species and other yeasts based on autoradiographic analysis of protein profiles of [35S]methionine-labeled cellular proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Using ATCC strains as references, protein profile analysis showed that different Candida and other yeast species produced distinctively different patterns. Good agreement in results obtained with this approach and with other conventional systems was observed. Being accurate and reproducible, this approach provides a basis for the development of an alternative method for the identification of yeasts isolated from clinical specimens.

Candida↗
PubMed1988

Antitumor activity of doxorubicin-monoclonal antibody conjugate on human bladder cancer.

Doxorubicin (adriamycin) was conjugated via the dextran bridge method to a murine IgG3 monoclonal antibody, 1G3.10, directed against human bladder cancer. The drug-antibody conjugate, prepared from using 25% oxidized dextran as the linker, retained essentially the original immunological activity of the antibody using ELISA as tested against an antigen-positive target cell line (TSGH-8301), which has been shown to express an antigen recognized by the monoclonal antibody 1G3.10. Antitumor effect of the conjugate in vitro was evaluated by its inhibition on 3H-uridine incorporation into the established human bladder cancer cells. The conjugate exhibited a significantly higher cytotoxicity on target TSGH-8301 cells than that by a control antibody-doxorubicin conjugate prepared identically from an irrelevant mouse IgG3 monoclonal antibody. No apparently different cytotoxicity was detected on control antigen-negative bladder tumor cells of J82 between these two drug-antibody conjugates. Verapamil, a calcium channel blocker, enhanced the in vitro cytotoxicity of doxorubicin-1G3.10 monoclonal antibody conjugate. Results obtained from in vivo evaluation using xenografted target TSGH-8301 bladder tumor indicated that the 1G3.10 monoclonal antibody conjugate containing doxorubicin injected 4X, i.p., significantly inhibited TSGH-8301 bladder tumor growth in nude mice, whereas free monoclonal antibody, free drug and the mixture of both showed only moderate inhibition of tumor growth as compared to the untreated control. Verapamil also enhanced in vivo antitumor activity of the conjugate. There was no side effect (weight loss) detected on the conjugate-treated mice. Results obtained from in vivo evaluation using xenografted control J82 bladder tumor showed no specific antitumor activity as exhibited by doxorubicin-1G3.10 monoclonal antibody conjugate in comparison with free drug, mixture of drug and antibody without conjugation, or doxorubicin conjugated to the irrelevant antibody. These results suggested that doxorubicin conjugated with bladder tumor associated monoclonal antibody could be useful as a potentially cytotoxic agent in immunochemotherapy of human bladder cancer.

Animals↗
PubMed1988

Identification of allergens and antigens of Bermuda grass (Cynodon dactylon) pollen by immunoblot analysis.

Allergens and antigens of Bermuda grass pollen fractionated by SDS-polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes were identified using twenty-one sera of Bermuda grass pollen-allergic patients. The IgE- and IgG-binding pollen components transferred to nitrocellulose were detected by reaction with enzyme-labelled anti-human IgE and anti-human IgG, respectively. There was heterogeneity in both IgE- and IgG-binding patterns of the allergic sera tested. Fourteen pollen components, ranging in molecular weight from 16,000 to 88,000 daltons, bound to IgE antibodies. Only two of the fourteen allergens identified reacted with IgE antibodies of more than 50% of the twenty-one allergic sera. The pollen component with a molecular weight of 32,000 daltons showed by far the highest frequency of IgE binding, being recognized by sixteen (76%) of the twenty-one sera examined. Fifteen (71%) of the twenty-one sera tested had IgE antibodies that reacted with more than one of the fourteen allergenic components identified. Pollen components recognized by IgE antibodies also reacted with IgG antibodies, and there were components only recognized by IgG antibodies. Results obtained from this study should be useful both clinically and in research.

Allergens↗
PubMed1988

Natural and activated cytotoxic lymphocytes reactivity to human hepatocellular carcinoma cell lines in hepatocellular carcinoma patients.

The status of cellular cytotoxic activity in Hepatocellular Carcinoma (HCC) patients was compared to that in normal individuals by testing the cytotoxicity against K562 and five established HCC cell line targets. Natural killer (NK) activity of fresh peripheral blood mononuclear (PBM) cells in HCC patients to K562 cell line target was lower than that in normal donors. NK activity of unstimulated PBM cells from either source was minute against all five HCC cell line targets. Three different activation systems were employed to examine the cellular cytotoxicity of activated PBM cells: (1) conventional mixed lymphocyte culture (MLC), (2) allogeneic mixed lymphocyte tumor culture (MLTC), and (3) lymphokine-activated killer (LAK) cell culture. The cytotoxic effects of PBM cells in all three activation conditions were significantly lower in HCC patients than in normal donors (P less than 0.05 to P less than 0.01). These results suggest that, in addition to naturally present NK cells, the degree of in vitro activation of PBM cells may also have decreased in HCC patients.

Carcinoma, Hepatocellular↗
PubMed1988

Rhizobium meliloti genes required for C4-dicarboxylate transport and symbiotic nitrogen fixation are located on a megaplasmid.

A mutant of Rhizobium meliloti unable to transport C4 dicarboxylates (dct) was isolated after Tn5 mutagenesis. The mutant, 4F6, could not grow on aspartate or the tricarboxylic acid cycle intermediates succinate, fumarate, or malate. It produced symbiotically ineffective nodules on Medicago sativa in which bacteroids appeared normal, but the symbiotic zone was reduced and the plant cells contained numerous starch granules at their peripheries. Cosmids containing the dct region were obtained by selecting those which restored the ability of 4F6 to grow on succinate. The Tn5 insertion in 4F6 was found to be within a 5.9-kilobase (kb) EcoRI fragment common to the complementing cosmids. Site-specific Tn5-mutagenesis revealed dct genes in a segment of DNA about 4 kb in size extending from within the 5.9-kb EcoRI fragment into an adjacent 2.9-kb EcoRI fragment. The 4F6 mutation was found to be in a complementation group in which mutations yielded a Fix- phenotype, whereas other dct mutations in the region resulted in mutants which produced effective nodules in most, although not all, plant tests (partially Fix-). The dct region was found to be located on a megaplasmid known to carry genes required for exopolysaccharide production.

Cosmids↗
PubMed1988

Sequence duplication and internal deletion in the integrated human papillomavirus type 16 genome cloned from a cervical carcinoma.

Integrated human papillomavirus type 16 (HPV16) sequences were cloned from a cervical carcinoma and analyzed by restriction mapping and nucleotide sequencing. The viral integration sites were mapped within the E1 and E2 open reading frames (ORFs). The E4 and E5 ORFs were entirely deleted. An internal deletion of 376 base pairs (bp) was found disrupting the L1 and L2 ORFs. Sequencing analysis showed that an AGATGT/ACATCT inverted repeat marked the deletion junction with two flanking direct repeats 14 and 8 bp in length. A 1,330-bp sequence duplication containing the long control region (LCR) and the E6 and E7 ORFs was also found. The duplication junction was formed by two 24-bp direct repeats with 79% (19 of 24) homology located within the LCR and the E2 ORF of the prototype viral genome, respectively. This observation leads us to propose that the initial viral integration involved an HPV16 dimer in which the direct repeats in tandem units recombined, resulting in reiteration of only a portion of the original duplication. A guanosine insertion between nucleotides 1137 and 1138 created a continuous E1 ORF which was previously shown to be disrupted. Results from this study indicate that sequence reiteration and internal deletion in the integrated, and possibly in the episomal, HPV16 genome are influenced by specific nucleotide sequences in the viral genome. Moreover, reiteration of the LCR/E6/E7 sequences further supports the hypothesis that the E6/E7 ORFs may code for oncogenic proteins and that regulatory signals in the LCR may play a role in cellular transformation.

Base Sequence↗
PubMed1988

Characteristics of five monoclonal antibodies to major allergens of the short ragweed pollen.

Monoclonal antibodies against major allergens of the short ragweed pollen were produced by fusion of NS-1 cells with splenic cells from BaLB/C mice that had been immunized separately with the major allergens, AgE-B + E-C and AgK, of the short ragweed pollen. These monoclonal antibodies were detected by enzyme-linked immunosorbent assay and further characterized by immunoblot analysis using the crude extract and highly purified allergens of the ragweed pollen. Three monoclonal antibodies obtained by immunization with AgE-B + E-C, designated as 36-6, 27-2 and 48-5, reacted mainly with the beta (36-6) and alpha (27-2) subunit of AgE and both AgE and AgK (48-5), respectively. Two monoclonal antibodies obtained by immunization with AgK, 4-7 and 8-5, had a similar reactivity with AgE-B + E-C, AgK, AgK-A and AgK-B. In addition, however, antibody 4-7 also reacted with AgE-B2 as well as the 36- and the 24- to 22-kilodalton antigens of the crude extract. All 5 monoclonal antibodies were characterized as IgGl subclass. Besides, monoclonal antibody 48-5 also showed cross-reactivity to components of sage pollen. Beyond academic interests, the monoclonal antibodies described here may also be useful in clinical allergy.

Allergens↗
PubMed1988

Radioimmunotherapy of xenografted human bladder cancer using monoclonal antibody against blood group A-related antigen.

An IgG3 murine monoclonal antibody 1G3.10 was generated against a human urinary bladder carcinoma cell line TSGH-8301. The tumor-associated antigen recognized by the monoclonal antibody is a blood group A-related substance. From fluorescence-activated cell sorter analysis, a direct cytolytic effect of tumor cells by the antibody at concentrations of more than 10 micrograms/ml was seen. The antibody could target iodine-131 to established subcutaneous human bladder carcinoma xenografts in BALB/c nude mice. Monoclonal antibody alone also showed some inhibitory effect on xenografted tumor growth. In this study, radiolabeled monoclonal antibody 1G3.10 presented more effective cytotoxicity than antibody alone from in vitro and in vivo experiments.

ABO Blood-Group System↗
PubMed1988

Controlled release of adriamycin HCl from polymeric needle devices.

Two types of polymeric needle devices (reservoir type and matrix type) were prepared. The release behavior and mechanism of adriamycin HCl from these needle devices were investigated and deduced. Adriamycin HCl released from reservoir type needle devices exhibited a zero order release kinetic, but a Higuchi membrane-diffusion controlled model was shown in matrix type needle devices. A lag time and burst effect were obtained in reservoir type and matrix needle devices, respectively. The release of adriamycin HCl from these needle devices was controlled and can be monitored by adding a hydrophilic or hydrophobic additive.

Biocompatible Materials↗
PubMed1988

The mechanisms of inhibitory effects of liver extract on lymphocyte proliferation: II. Inhibition of DNA, RNA, and protein synthesis and their relationship to the effects of metabolic inhibitors.

The inhibitory effects of liver extract (LEx) on DNA, RNA, and protein synthesis in phytohaemagglutinin (PHA)-stimulated lymphocytes were studied by measuring the incorporation of labelled precursors. DNA, RNA, and protein synthesis were all inhibited by LEx in a dose-related manner. The inhibitory effect of LEx on protein synthesis was additive to the inhibitory effect of puromycin. The inhibitory effect of LEx on DNA synthesis was antagonistic to the inhibitory effect of mitomycin C. In the case of actinomycin D for RNA synthesis, its interactions with LEx were variable, but not additive. LEx may act as an inhibitor of protein synthesis through the mechanism of arginine-depletion.

Animals↗
PubMed1988

Monoclonal antibodies specific for human IgE and their clinical applications.

By applying the hybridoma technique, two mouse anti-human Immunoglobulin E (IgE) monoclonal antibodies, designated as E17-58 and E20-62, were generated and characterized. E17-58 was a murine IgG2b with an affinity constant of 4 x 10(8)l/mole. E20-62 was a murine IgG1 with an affinity constant of 1 x 10(8) l/mole. These two antibodies recognized different antigenic determinants specific to the IgE molecule. They were used in combination to quantify the total serum IgE level of forty-nine persons. Data obtained correlated highly with that obtained by using the Pharmacia PRIST Kit (r = 0.91). E17-58 was also used to detect the anti-Aspergillus specific IgE of twenty-one atopic patients by a radioimmunosorbent test. The positive rate detected correlated very well with the skin test (p less than 0.05). In addition, in the Western blot system, these monoclonal antibodies were capable of identifying IgE binding components of crude allergen extracts. Extracts from pollens of Bermuda grass were evaluated, and a new major allergenic component with a molecular weight of 40 kd was identified.

Animals↗
PubMed1988

A cytotoxic monoclonal antibody produced from a human urinary bladder carcinoma cell line (TSGH-8301).

A mouse monoclonal antibody, designated 1G3.10, directed against a human urinary bladder cancer cell line TSGH-8301 was generated using the conventional hybridoma technique. It was of the IgG3 subclass with a restricted specificity to bladder cancer and several epithelial cancers, as detected on a panel of various cell lines and tissues by radioimmunoassay and indirect immunofluorescence methods. It also exhibited a strong binding activity to human group A red blood cells, as demonstrated in hemagglutination and absorption tests. Radioimmunoprecipitation and thin-layer chromatography revealed that the antigens recognized by the antibody are a mixture of glycopeptides (M.W. 30, 54, and 108 KD) and glycolipid (retardation factor 0.67-0.83). From a fluorescence activated cell sorter (FACS) study, direct killing of tumor cells by the antibody at a concentration of more than 10 micrograms/ml was observed. This antibody could also mediate both antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) in vitro when tested in a 4-hr 51Cr-release test. These results suggest that the monoclonal antibody 1G3.10 may provide an agent for further immunodiagnosis and the treatment of human bladder cancer.

ABO Blood-Group System↗