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Biomedical subjects

H Hsu

Publications and source records attributed to H Hsu.

87 records · Page 5Linked to original sources
PubMed1980

The ultrastructure of mucoid "onionskin" intimal lesions in malignant nephrosclerosis.

The ultrastructure of mucoid "onionskin" intimal thickening in the intrarenal arteries was studied in 12 cases of malignant hypertension. The thickened areas were found to contain proliferating myointimal cells, basement membrane lamellas, and ruthenium-red--positive proteoglycans. The proteoglycans consisted of granules 15--35 nm in diameter and thin filaments about 3 nm thick. The filaments connected the granules to each other and to the basement membranes of the concentric lamellas, to the basement membranes of the endothelial and myointimal cells, and also to the cell surfaces. This arrangement imparted a loose meshwork pattern to the mucoid layer. The granulofilamentous material is considered to be a structural component of the pathologic lesion distinct from plasma insudation. The relationship between the intercellular substances and the myointimal cells is briefly discussed.

Arterioles↗
PubMed1975

Translation of messenger ribonucleic acid from isolated pancreatic islets and human insulinomas.

RNA preparations from isolated rat pancreatic islets and from human insulinomas were injected into oocytes of Xenopus laevis which were then incubated with [3H]leucine. Acid-ethanol extracts of the oocytes were immunoprecipitated with anti-insulin serum using the double antibody technique. Sodium dodecyl sulfate disc gel electrophoresis of the immunoprecipitates showed the presence of an insulin-displaceable immunoreactive material with a molecular weight of about 18,000 in extracts from oocytes injected with RNA of 9-11 S. This immunoreactive product was not detected in extracts from oocytes injected with buffer or 4-8S RNA or RNA heavier than 11 S. These observations suggest the involvement of a precursor larger than proinsulin in the biosynthesis of insulin.

Adenoma, Islet Cell↗
PubMedDate not supplied

Preparation of N epsilon B28-monoazidobenzoyl insulin-like growth factor I and photoaffinity labeling of insulin-like growth factor I receptor.

Recombinant human insulin-like growth factor I (hIGF-I) was reacted with azidobenzoyl hydroxysuccinimide to produce a mixture of photoactive hIGF-I derivatives. The mixture was purified by reversed-phase HPLC to yield three mono-substituted azidobenzoyl hIGF-Is. One of the derivatives was identified by amino acid sequencing as N epsilon B28-monoazidobenzoyl hIGF-I. This derivative was indistinguishable from native hIGF-I when bioassayed in Rat-1 fibroblasts. A 120-kDa band, the alpha subunit of the IGF-I receptor, was specifically labeled in Rat-1 plasma membranes by this photoprobe. The labeling of this band was reduced by hIGF-I at 1 nM and completely abolished by hIGF-I, but not insulin, at 100 nM, indicating the specificity of the photolabeling of the IGF-I receptor by this fully active IGF-I photoprobe.

Affinity Labels↗
PubMedDate not supplied

Ultrasound-guided cardiac blood sampling of the rabbit fetus.

The object of the study was to determine whether cardiac sampling of the rabbit fetus could be successfully accomplished with minimal procedure-related loss. Pregnant rabbit dams were randomized to undergo ultrasound-guided fetal cardiac sampling in either the left or right uterine horn at 27 days of gestation; cesarean delivery was performed the following day. Liveborn pups from unsampled uterine horns underwent cardiac puncture immediately after birth. Fetal hematologic parameters were then compared to neonatal parameters. The acute fetal mortality from the sampled uterine horns was similar to that of the unsampled horns (3.6 vs. 4.5%). Fetal hematologic values were significantly higher than neonatal values with the exception of the reticulocyte count. This rabbit model offers a new approach for the evaluation of novel treatment modalities for hemolytic disease of the human fetus.

Animals↗
PubMedDate not supplied

Combined radiation and cytochrome CYP4B1/4-ipomeanol gene therapy using the EGR1 promoter.

BACKGROUND: Cytochrome p450 isozyme CYP4B1 converts the inert prodrug 4-ipomeanol (4-IM) into toxic alkylating metabolites. Induction of cytotoxicity by 4-IM combined with ionizing radiation (IR) in cells transfected with a fusion protein of rabbit cytochrome CYP4B1 under control of the radiation inducible EGR1 promoter was investigated. The capability of activated 4-IM to sensitize cells to IR was also assessed. MATERIALS AND METHODS: Survival fractions of cells, determined by MTT assays, stably transfected with EGR1-CYP4B1 were compared with that of cells transfected with a control plasmid after IR followed by 4-IM. Radiosensitization was tested by comparing clonogenic survival curves of cells transfected with the CYP4B1 cassette under a CMV promoter instead of EGR-1, irradiated with or without 4-IM. RESULTS: MTT assays for cytotoxicity indicated a decrease in relative survival fractions (survival with 4-IM/survival without 4-IM) of the EGR1-CYP4B1 transfected cells with increasing radiation dosage, but not of control cells. Clonogenic assays revealed decreased survival fractions with increasing radiation doses (CYP4B1 transfected and control cells) and 4-IM concentrations (CYP4B1 transfected cells), but showed no significant differences in slope of survival curves with 4-IM. CONCLUSION: The results indicate IR potentiates the cytotoxic activity of the EGR1-CYP4B1/4-IM transgene system, but activated 4-IM does not sensitize cells to IR. Thus, the EGR1-CYP4B1/4-IM system is a viable radiation-gene therapy system that may allow for improved spatial and temporal control of cytotoxicity by therapeutic radiation fields.

Animals↗
PubMedDate not supplied

A prospective randomized evaluation of chronic peritoneal catheters. Insertion site and intraperitoneal segment.

The insertion site (midline or through the lateral rectus muscle) and type of chronic dialysis catheter (straight or spiral intraperitoneal segment) were evaluated in a prospective randomized trial. Dialysis catheter complications and catheter survival were the endpoints of evaluation. Eighty-five first catheters were evaluated. Neither race, gender, renal diagnosis, type of catheter, nor insertion site was a determinant of dialysis catheter survival. Overall median catheter survival was 308 days. There were 40 catheter complications (70%, n = 28) that occurred during the first 61 days following insertion. Median time to the first complication occurring within the first 61 days was 3 days. Late catheter removals were due to peritonitis episodes that failed to resolve. Complications are frequent with peritoneal dialysis catheters, and care of the peritoneal dialysis catheters requires constant vigilance.

Adult↗