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Biomedical subjects

S Chu

Publications and source records attributed to S Chu.

167 records · Page 10Linked to original sources
PubMedDate not supplied

Insulin-like growth factor, insulin-like growth factor-binding protein-4, and pregnancy-associated plasma protein-A gene expression in human granulosa cell tumors.

The insulin-like growth factor (IGF) system plays an important role in folliculogenesis. It is also thought to contribute to the pathogenesis of many cancers, including those of the ovarian epithelium. In the human follicle, the predominant IGF is IGF-II and its actions are modulated by insulin-like growth factor-binding protein-4 (IGFBP-4), the IGFBP-4 protease, and the pregnancy-associated plasma protein-A (PAPP-A). These peptide components are synthesized by the granulosa cells of the developing follicle. The aim of this study was to characterize the expression of these components of the IGF system in granulosa cell tumors (GCT) of the ovary. IGF-I, IGF-II, IGFBP-4, and PAPP-A gene expression was determined in a panel of GCT and compared to the levels in normal ovary and in epithelial ovarian tumors. Although both the IGF-I and IGF-II genes were expressed in the GCT, the levels were lower than in the other tissue groups. IGFBP-4 expression was also low in the GCT, whereas PAPP-A gene expression was highest in the GCT. These findings were unexpected given the prominent role this signaling system plays in normal granulosa cells. In conclusion, these observations suggest that the IGF system may have a limited role in the pathogenesis of GCT with PAPP-A subserving a function other than IGFBP-4 proteolysis.

Adult↗
PubMedDate not supplied

Efficacy of a combination vaccine containing MDV CVI 988 strain and HVT against challenge with very virulent MDV.

With the emergence of very virulent Marek's disease virus (MDV) strains, vaccines based on herpesvirus of turkeys (HVT) appear to be not powerful enough to confer full protection, whereas in chicken flocks vaccinated with MDV CVI 988 strain protective immunity sometimes is generated not early enough for full protection. For this reason combination vaccines containing HVT as well as CVI 988 have been developed. In this paper the beneficial effect of combining both types of virus strains in one vaccine for early protection is shown in a vaccination challenge experiment, in which one-day-old chickens were vaccinated with suboptimal dosages of the monovalent vaccines and the same dosages in a combination vaccine. After 5 days the chickens were challenged with a very virulent MDV strain and subsequently observed for a period of approx. 50 days. It appeared that the combination vaccine provided better early protection than the monovalent vaccines. In addition, the combination vaccine was tested as vaccine administered in ovo. It appeared that after in ovo vaccination the vaccine conferred adequate protection against challenge with a very virulent MDV strain, 5 days after hatch, and that protection after in ovo vaccination was similar to that obtained after subcutaneous vaccination with the same combination vaccine.

Animals↗
PubMedDate not supplied

Fluoride release from a light-cured bonding material in openbite orthodontic patients.

This study was undertaken to clarify whether the salivary fluoride concentration on the anterior and premolar teeth, released from an orthodontic bonding material, differed between openbite and non-openbite patients. Using fluoride-releasing bonding materials, brackets were bonded to the teeth in openbite and in non-openbite patients. Saliva films on the tooth surfaces near the brackets were collected with filter paper and fluoride concentrations in the saliva were determined by using a fluoride electrode technique. Saliva was collected and analyzed at different periods after the bonding. Fluoride concentrations in the saliva increased sharply immediately after bonding, decreased gradually thereafter, then leveled off. Fluoride concentrations in the saliva on the tooth surfaces were higher in openbite patients for one day to as long as one week. The results of the two-way analysis (ANOVA) showed that the differences in the overbite factor (openbite, non-openbite) contributed to the variances the most (p < 0.001; contribution, 59.50 percent after one day and p < 0.01; contribution, 49.63 percent after 3 days). In conclusion, the fluoride released from the bonding materials on the tooth surfaces was retained more in openbite than in non-openbite patients, suggesting their lower flow rate of saliva.

Adhesives↗