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Full-Text Articles in Medical Specialties
Cell Encapsulation As A Potential Nondietary Therapy For Maternal Phenylketonuria, Donna Santillan, Mark Santillan, Stephen Hunter
Cell Encapsulation As A Potential Nondietary Therapy For Maternal Phenylketonuria, Donna Santillan, Mark Santillan, Stephen Hunter
Stephen K. Hunter
OBJECTIVE: The objective of this work was to determine whether cells overexpressing phenylalanine (Phe) hydroxylase (PAH) can significantly reduce Phe in vitro for potential use as a therapy for preventing maternal phenylketonuria. STUDY DESIGN: Human 293T and WRL68 cell lines were transiently and stably transfected to overexpress PAH. Cells were encapsulated within microspheres of sodium alginate. Timed measurements of Phe in media were performed using tandem mass spectrometry. RESULTS: Both nonencapsulated and encapsulated transiently transfected cells overexpressing PAH significantly reduced the Phe concentration in media by approximately 50% in comparison to mock-transfected cells. Cell line clones stably expressing PAH significantly …
Biodegradable Microspheres Containing Group B Streptococcus Vaccine: Immune Response In Mice, Stephen Hunter, M. Andracki, A. Krieg
Biodegradable Microspheres Containing Group B Streptococcus Vaccine: Immune Response In Mice, Stephen Hunter, M. Andracki, A. Krieg
Stephen K. Hunter
OBJECTIVE: This study seeks to show the feasibility of producing a group B Streptococcus (GBS) vaccine, which is capable of producing both a local IgA immune response at the mucosal surface where GBS is colonized and a humoral IgG response, which is capable of transplacental passive immunization. STUDY DESIGN: Inactivated GBS antigen was microencapsulated in poly (D, L-lactic-co-glycolic acid) (PLG) with a water-in-oil-in-water double emulsion technique. Immunostimulatory synthetic oligodeoxynucleotides containing cytidine-phosphate-guanosine (CpG) motifs were coencapsulated as a potent adjuvant. The ICR strain of mouse was used in these studies. Female mice with normal immune systems were immunized with the PLG …
Encapsulated Beta-Islet Cells As A Bioartificial Pancreas To Treat Insulin-Dependent Diabetes During Pregnancy, Stephen Hunter, Y. Wang, C. Weiner, Jennifer Niebyl
Encapsulated Beta-Islet Cells As A Bioartificial Pancreas To Treat Insulin-Dependent Diabetes During Pregnancy, Stephen Hunter, Y. Wang, C. Weiner, Jennifer Niebyl
Stephen K. Hunter
OBJECTIVE: Our purpose was to determine the effectiveness of the bioartificial pancreas technique in correcting (1) maternal carbohydrate metabolism and (2) fetal malformation rates in a pregnant diabetic animal model. STUDY DESIGN: Insulin secretion from encapsulated rat islets cultured in the presence of homologous rat prolactin was determined and compared with that of controls. Streptozotocin-induced diabetic Balb/c mice were then transplanted with rat islet cells encapsulated within alginate microbeads and were then bred. Blood glucose determinations were made after transplantation and throughout gestation. Pups were delivered by cesarean section on day 19 of gestation. Outcome parameters from the transplanted study …
Protective Immunization In Mice Against Group B Streptococci Using Encapsulated C5a Peptidase, Donna Santillan, M. Andracki, Stephen Hunter
Protective Immunization In Mice Against Group B Streptococci Using Encapsulated C5a Peptidase, Donna Santillan, M. Andracki, Stephen Hunter
Stephen K. Hunter
OBJECTIVE: The purpose of the study was to test whether C5a peptidase encapsulated within a biodegradable polymer can act as a vaccine and elicit an immune response to prevent group B streptococci (GBS) infection in mice and provide protection to pups. STUDY DESIGN: C5a peptidase was encapsulated in semipermeable microspheres of poly(lactide-co-glycolide). Female ICR mice were immunized with encapsulated C5a peptidase, free C5a peptidase, or empty microparticles. Booster doses were given at days 21 and 42. Antibody responses were measured by enzyme-linked immunosorbent assay. Challenge with GBS type III was performed 4 days after the final booster in the vaginal …
Bioartificial Pancreas Use In Diabetic Pregnancy, Stephen Hunter, Y. Wang, V. Rodgers
Bioartificial Pancreas Use In Diabetic Pregnancy, Stephen Hunter, Y. Wang, V. Rodgers
Stephen K. Hunter
The purpose of this study was to evaluate the feasibility and effectiveness of Bioartificial Pancreas (BAP) technology use during diabetic pregnancy. In particular, the study asked 1) can microencapsulated islet cells effectively correct carbohydrate metabolism during diabetic pregnancy and 2) will such therapy, if initiated before conception, eliminate diabetes-induced congenital malformations in the fetus? Streptozotocin-induced diabetic female mice (ICR) received transplants of rat islets encapsulated within alginate microbeads. Animals were placed with male mice and bred. Random, nonfasting blood glucose (BG) determinations were made posttransplantation and throughout pregnancy. Pups were delivered by cesarean section on day 19 of gestation. Outcome …
Mathematical Modeling Of Myoglobin Facilitated Transport Of Oxygen In Devices Containing Myoglobin-Expressing Cells, H. Tilakaratne, Stephen Hunter, V. Rodgers
Mathematical Modeling Of Myoglobin Facilitated Transport Of Oxygen In Devices Containing Myoglobin-Expressing Cells, H. Tilakaratne, Stephen Hunter, V. Rodgers
Stephen K. Hunter
Low pO(2) is perhaps the most significant factor in artificial pancreas failure. In these environments, not only is the beta cell production of insulin reduced, but the cell death rate is also significantly higher. Mathematical models are developed to test the feasibility of facilitated oxygen transport in enhancing O(2) flux to genetically engineered cells in a bioartificial device such as a pancreas. For this device, it is proposed that beta cells be genetically engineered to express myoglobin throughout the cell. In addition, the significance of including myoglobin throughout the alginate matrix present to provide immuno-protection for the transplanted cells is …