PubMed Health⌕ Search

Biomedical subjects

D Duke

Publications and source records attributed to D Duke.

33 records · Page 2Linked to original sources
PubMed1988

Fetal islet allotransplantation in rabbits.

Haploidentical fetal rabbit islets were transplanted into the renal subcapsular space of outbred maternal hosts. Islets were prepared by a mild collagenase digestion and were cultured in air and a high oxygen environment for 10 days prior to implantation. Grafts were examined at 14 days and later. No grafts survived in the absence of host immunosuppression, even when treatment of the donor tissue included both culture and ultraviolet-B irradiation (groups 1 and 3). With a high dose of oral cyclosporine, 30 mg/kg/day on days 0-3, viable but disrupted islets were present in 1/7 recipients of islets treated by culture alone. Only with high-dose peritransplant cyclosporine or chronic low-dose immunosuppression, and islet treatment with UVB and culture, was regular graft survival achieved (groups 4A and 5). These results demonstrate that haploidentical outbred hosts can be made to accept fetal islet allografts pretreated by UVB irradiation and culture in a high oxygen environment only if the recipient is given a high peritransplant dose of oral cyclosporine (30 mg/kg/day) or chronic low-dose cyclosporine, (10 mg/kg/day).

Animals↗
PubMed1987

Calcium phosphate crystal occlusion of central venous catheters used for total parenteral nutrition in infants and children: prevention and treatment.

Calcium phosphate crystal occlusion is a complication occasionally encountered with long-term indwelling Silastic central venous catheters used for total parenteral nutrition (TPN) in infants and children. These occluded catheters are usually treated by removal. We have successfully treated six patients who experienced seven episodes of calcium phosphate crystal central venous catheter occlusion by irrigating their catheters with a hydrochloric (HCl) acid heparin solution. Although temporary febrile reactions occurred in three cases (42%), no serious complications were encountered. An average of 46 catheter-days per patient episode were preserved. By paying close attention to the calcium and phosphate concentrations in a patient's TPN solution, the clinician can minimize the risk of calcium phosphate precipitation. If central venous catheter occlusion does occur due to precipitation of calcium phosphate crystals, then HCl-heparin irrigation is a safe and effective method for salvaging such catheters.

Calcium Phosphates↗
PubMed1983

Antibody response of nude (RNU/RNU) and hairy (RNU/+) rats to circulating cell surface components from human pancreatic cancer xenografts.

Homozygous nude rats (rnu/rnu) injected s.c. with 3 X 10(7) human pancreatic cancer cells from the GER cell line developed circulating antibody to GER cell surface, detected in a 125I binding assay against viable GER cells in vitro. Antibody titre rose with progressive xenograft growth. These antibodies showed no selectivity for GER cells when compared with a panel of other human cell lines. Heterozygous nude rats (rnu/+) immunised with serum from their GER xenograft-bearing nude relatives (rnu/rnu) also developed anti-GER cell surface antibodies. These antibodies showed some selectivity for GER and WAD (a second human pancreatic cancer cell line) when compared with other human cancer cells and lymphocytes. These findings show that some human pancreatic cancer cell surface components may persist independently in the circulation of xenograft bearing rnu/rnu rats despite the presence of antibody excess to other surface determinants from the same cells. It is suggested that differences in the relative immune competence of rnu/rnu and rnu/+ rats may offer a biological opportunity for enhancing the recognition of weak antigenic determinants which may have some useful selectivity for different types of human tumour cells.

Adenocarcinoma↗
PubMed1981

Production of antibodies against antigens released from human pancreatic tumour xenografts.

Antibodies directed against the antigen released from viable tumour cells during growth have been raised by cross-immunization of immunocompetent hairy litter-mates with serum from nude mice bearing pancreatic tumour xenografts. Antisera raised against the components released from a primary pancreatic tumour xenograft (WB) or from a tumour cell-line xenograft (GER) showed a titre greater than 1:625 against cultured pancreatic tumour cells by an I125-binding assay. Five out of 14 of the hairy litter-mates immunized with serum from the same tumour (GER) produced antisera that bound more strongly to pancreatic cancer cells than to 13 other non-pancreatic cell lines (binding ratio greater than 2). Absorption of the antisera with pure CEA reduced the level of binding by 11-25% without affecting the specificity for pancreatic tumour cells. The antibody response could be completely removed by absorption with pancreatic tumour cells, whereas 50% and 18% of the activity remained after absorption with normal pancreas homogenate and a mixed non-pancreatic tumour-cell pool, respectively. Immunofluorescent staining of pancreatic tumour sections indicated that the antibody was localized on the membrane of ductular epithelial cells. Challenge of immunocompetent mice using this procedure has produced a polyspecific antiserum with signs of selectivity for the circulating antigens released from pancreatic cancer cells, and may provide a route to the production of antibody against specific tumour components.

Animals↗
PubMed1981

Growth of human digestive-tumour xenografts in athymic nude rats.

The athymic nude rat rnu/rnu has been established as an in vivo model for the acceptance of human digestive-tumour xenografts. We report the successful xenografting of 7/12 (58%) primary explants from patients with digestive cancer. Successful xenografting also occurred in 21/25 (84%) pancreatic tumours derived from a pancreatic exocrine adenocarcinoma (GER) maintained in cell culture; 2 of those have been successfully passaged in nude rats. The simultaneous implantation of these tumours into nude mice led to an almost identical take rate. Passage of one colonic and one pancreatic xenograft from nude rats into nude mice, and transplantation back into nude rats, increased the take rates. The critical period for the establishment of primary tumour growth was usually 28-42 days. The xenografts maintained histological and cytological characteristics of the primary explants or of the original tumour from which the cell line derived. The karyotype of the cell line was also maintained in the solid tumour. Three murine tumours were successfully grown as xenografts. Despite their immunoincompetence, the rats in this study showed no increased morbidity or mortality when kept in conventional conditions, compared with animals housed in isolators. The athymic nude rat will become a valuable complementary tool to the nude mouse for the establishment and maintenance of human digestive tumours and for surgical and serial serological studies.

Adenocarcinoma↗
PubMed1979

Establishment and characterization of primary human pancreatic carcinoma in continuous cell culture and in nude mice.

Primary human panceratic exocrine adenocarcinoma has been established in tissue culture and as xenografts in immune-deficient nu/nu mice. The cell line has a doubling time of 36 h and grows as a confluent monolayer together with a constant population of free-floating cells. Evidence of tumourigenicity was provided by growth on an early diploid fibroblast monolayer and in soft agar, and as solid tumours in immune-deficient nu/mu mice. Chromosome analysis of the cultured cells confirmed their tumour origin. Xenografts established from the cell line or directly from primary tumour tissue have retained a similar histology to the original tumour on serial transplantation. An electrophoretic study of exportable pancreatic digestive enzymes and a number of intracellular enzymes has shown that the cell line and xenografts maintain a human intracellular enzyme profile, but do not produce pancreatic digestive enzymes.

Adenocarcinoma↗
PubMedDate not supplied

Transvaginal aspiration of ovarian cysts: long-term follow-up.

BACKGROUND AND PURPOSE: Transvaginal aspiration of ovarian cysts has been advocated as a viable alternative to surgery in patients who are high-risk surgical candidates. We describe a retrospective study evaluating the results of transvaginal aspirations of benign ovarian cysts in patients at increased surgical risk, focusing on long-term follow-up for recurrence of the cyst and/or development of malignancy. METHODS: Twenty-four women with ovarian cysts underwent 34 transvaginal drainages between October 1998 and December 2004. All patients were referred following diagnosis of a persistent ovarian cyst with a benign appearance on ultrasound. All patients were unsuitable candidates for surgery (history of previous pelvic surgery, n = 21; high risk for anesthesia, n = 1; and unsuitable for laparoscopy due to obesity, n = 2). Patients with a history of pregnancy, acute abdominal symptoms, or previous gynecologic malignancy were excluded. A 20G x 20 cm Chiba needle was used for transvaginal aspiration using an endocavity probe (Acuson XP, Mountain View, CA, USA; Siemens Sololine, Erlangen, Germany) and intravenous sedoanalgesia. Cysts were aspirated to dryness. RESULTS: Long-term follow-up of patients was performed and revealed a recurrence rate of 75%. Eighty-three percent of cysts on the left and 42% of those on the right recurred. Nine of 15 (60%) patients with recurrence required further intervention. Two of 9 underwent surgical intervention only, 4 of 9 had repeat transvaginal aspiration(s) performed, and 3 of 9 had a combination of both transvaginal aspiration and surgery. No patient developed ovarian malignancy. CONCLUSION: Transvaginal cyst aspiration has many advantages including short hospital stay, rapid recovery, excellent patient tolerance, and a low rate of procedure-related complications. Our study demonstrates that ovarian cyst recurrence following transvaginal drainage is a more significant problem than previously documented, especially if the cyst is on the left side. However, when recurrences do occur, repeat transvaginal aspirations may be considered in the symptomatic patient.

Adult↗