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H H Chang

Publications and source records attributed to H H Chang.

84 records · Page 5Linked to original sources
PubMed1975

Excretion of radioactive diadzein and equol as monosulfates and disulfates in the urine of the laying hen.

The phytoestrogen, diadzein, was injected intramuscularly as [4-14-C]daidzein into two laying hens. The radioactive materials in the urine for the succeeding 23 (hen 1) or 14 (hen 2) days were fractionated on a DEAE-Sephadex column by a gradient of NaCl and the fractions thus separated were further analyzed by solvent partition, susceptability to enzymic cleavage and thin-layer chromatography. The sic following components were identified and quantitated: [14-C]diadzein, [14-C]equol, [14-C]diadzein monosulfate, [14-C]equol monosulfate, [14-C]diazein disulfate, and [14-C]equol disulfate. The urine from hen 2 yielded also the sulfate of an unidentified conversion product of [14-C]daidzein. Repeared tests for glucuronides of [14-C]daidzein or its conversion products gave negative results, excluding the possibility that any appreciable proportion of the radioactivity in the urine was in the form of beta-glucuronide. It is concluded that the diadzein and the equol excretion in the urine of the laying hen are present for the most part as monosulfates and disulfates.

Animals↗
PubMedDate not supplied

Receptor-mediated endocytosis as a selection force to enrich bacteria expressing rhodostomin on their surface.

Previously, we developed a TraT display system to express snake venom rhodostomin (RHO), a disintegrin, on the external surface of Escherichia coli [J Biomed Sci 6:64-70;1999]. To show a new potential use of the TraT display system, we employed a biotin labeling technique coupled with SDS-PAGE and flow cytometry analyses to further demonstrate and confirm the expression of TraT-RHO on the E. coli surface. We also showed that the expression of TraT-RHO on the cell surface not only facilitated the bacteria adhesion to BHK-21 cells but also induced bacterial internalization into BHK-21 cells. This feature allowed us to enrich the TraT-RHO expression bacteria about 10,000-fold starting with a mixture of TraT-RHO bacteria with beta-galactosidase-positive bacteria in a ratio of 10(2):10(7) through four cycles of BHK-21 cell endocytosis and replating of engulfed bacteria on agar plates. We therefore suggest that the TraT display system can be applied to select out bacteria expressing a specific peptide sequence from a large population of display library through the process of receptor-mediated endocytosis and reamplification cycles.

Animals↗
PubMedDate not supplied

DNA vaccination using the fragment C of botulinum neurotoxin type A provided protective immunity in mice.

Botulinum neurotoxin (BoNT) is one of the most toxic substances known to produce severe neuromuscular paralysis. The currently used vaccine is prepared mainly from biohazardous toxins. Thus, we studied an alternative method and demonstrated that DNA immunization provided sufficient protection against botulism in a murine model. A plasmid of pBoNT/A-Hc, which encodes the fragment C gene of type A botulinum neurotoxin, was constructed and fused with an Igkappa leader sequence under the control of a human cytomegalovirus promoter. After 10 cycles of DNA inoculation with this plasmid, mice survived lethal doses of type A botulinum neurotoxin challenges. Immunized mice also elicited cross-protection to the challenges of type E botulinum neurotoxin. This is the first study demonstrating the potential use of DNA vaccination for botulinum neurotoxins.

Animals↗
PubMedDate not supplied

Expression of CD5 on hematogones in a 7-year-old girl with Shwachman-Diamond syndrome.

We report increased numbers of hematogones in a 7-year-old girl with pancytopenia due to Shwachman-Diamond syndrome. Her hematogones expressed the T-cell marker CD5 as well as CD19, CD10, and CD20, and terminal deoxynucleotidyl transferase and HLA-DR. These findings suggest that hematogones are precursors of both CD5-positive B cells and CD5-negative B cells. Thus CD5-positive B cells in bone marrow may be derived from bone marrow stem cells, and not from the residual fetal B cells of yolk sac/liver origin. The finding of CD5 expression on hematogones also raises the possibility that neoplastic B cells of chronic lymphocytic leukemia, which characteristically co-express CD5 and CD19, may be derived from CD5-positive B-cell precursors in bone marrow and not from mature B cells in lymph nodes.

B-Lymphocytes↗
PubMedDate not supplied

Hospital autopsies: still valuable in their traditional role but in need of reform.

In 1997, 158 autopsies were performed at Charleston Area Medical Center, a community-based, teaching tertiary care center. The autopsies revealed 29 (18.4%) clinically undiagnosed principal causes of death, of which 79% were considered treatable. The five leading undiagnosed causes were: infarctions, 27.6%; malignant neoplasms, 17.2%; pulmonary emboli, 13.8%; dissecting or ruptured aortic aneurysms, 13.8%; and genetic or congenital disorders 10.2%. These results were significantly different from those reported from some other major tertiary care centers. Reports were completed in 5-302 days (average 59, median 32 days). For more than 40 (25%) of these autopsies, the purpose was only to confirm specific disorders such as occupational injury, which can be accomplished by a highly selective, cost-effective posthumous analysis. In summary, an autopsy in today's high-technology era is still useful, however, the high cost, long length of reporting time, and number of clinically non-enlightening cases are a reasons to reform both the format and procedure in which these procedures are conducted.

Adolescent↗
PubMedDate not supplied

Malignant carcinoid tumor and synchronous malignant extraadrenal paraganglioloma.

Gastrointestinal carcinoid tumor is often considered the most common neuroendocrine tumor of the small intestine. The overall incidence of 1% in the general population is quite low. Extraadrenal paragangliomas are rarer still, and the incidence of both of these tumors in the malignant state is exceedingly rare. This article describes the case of a patient who had both a malignant carcinoid tumor as well as a malignant retroperitoneal paraganglioma occurring synchronously. A review of the literature concerning these tumors is also presented.

Carcinoid Tumor↗