PubMed Health⌕ Search

Biomedical subjects

S G Pollard

Publications and source records attributed to S G Pollard.

At least 37 records · Page 2Linked to original sources

An evaluation of the cyclosporine parent-compound-specific whole blood TDx assay.

The new Abbott TDx cyclosporine parent-compound-specific fluorescence polarization immunoassay (TDxP) was evaluated and compared to the cyclosporine-and-metabolites-specific TDx (TDxT) and a cyclosporine parent-compound-specific radioimmunoassay (RIA) (Sandimmun-Kit, INCSTAR). The TDxP assay was linear within the range of 31 to 1600 ng/ml (r = 0.985) with a lower limit of detection of less than 31 ng/ml. The TDxP had excellent intra- and interassay reproducibility (CV = 1.2 to 4.5) that was significantly better than that of the radioimmunoassay. 230 whole blood samples obtained from 65 kidney, 19 liver, and 8 pancreas transplant recipients were analyzed with each of the three assay methods. TDxP had a much stronger correlation with the RIA than did TDxT (r = 0.95 versus 0.83). The difference between the correlations was greatest for the liver and pancreas recipients. The mean ratio of the cyclosporine level determined by TDxP to RIA was 1.0 versus 2.4 for TDxT to RIA. The new TDxP assay provides results equal to a parent-compound-specific RIA but with the added advantages of decreased sample turn-around time and improved intra- and interassay coefficients of variation.

Cyclosporine↗

Breast sarcoma. A clinicopathologic review of 25 cases.

Sarcoma of the breast represents less than 1% of primary mammary malignancies; this study reports 25 such cases. The largest group had malignant fibrous histiocytoma (44%), followed by liposarcoma (24%) and fibrosarcoma (16%). Also represented were clear cell sarcoma, neurogenic sarcoma, leiomyosarcoma, and alveolar soft part sarcoma (4% each). Of 19 patients treated by wide local excision or simple mastectomy with or without adjuvant radiotherapy, 11 had local recurrence develop, of which one patient died and nine of the remaining ten had metastases develop. Of the remaining eight patients in this group with no local recurrence, only two had metastases develop. Of the six patients treated by radical or Patey mastectomy, none had local recurrence develop, but two died of metastases. No patient had metastases develop more than 5 years after diagnosis. Regional lymph node involvement with tumor was observed in only one patient (with malignant fibrous histiocytoma) despite regional lymphadenopathy in seven. The overall mortality at 5 years is 64% but does not increase thereafter. The authors' findings suggest that failure to establish local control is associated with a poor prognosis and that wide local excision or simple mastectomy does not provide sufficient clearance to be used as first-line treatment. Excision of the axillary lymphatics and adjuvant radiotherapy are unlikely to be beneficial.

Adult↗

Liver transplantation in cancer--a review.

Whilst liver transplantation is an accepted therapeutic modality for end stage cirrhosis, its application for hepatic malignancy has remained a controversial issue. This is due to the early experience in several centres of tumour recurrence within the first year. More recently, stringent patient selection criteria have been established to decrease the risk of tumour recurrence. Pre-operative assessment including liver biopsy, computerised axial tomography (CT) of both the thorax and abdomen, bone scans and pre-transplant laparotomy are routinely performed to exclude extrahepatic spread. Of the primary tumours, the most common groups are the hepatocellular carcinomas (HCC) and cholangiocarcinomas. A hierarchy of tumours favourable for transplantation exists, with HCC giving the best results, followed by central bile duct carcinoma, cholangiocellular carcinoma (peripheral), and secondaries, in descending order of suitability. With better patient selection based on adequate staging, and the confinement of liver grafting to lymph node negative stages, there has been a marked improvement in survival in otherwise unresectable and mainly untreatable tumours. The improved results support the application of liver grafting for malignancy, and suggest that the often discussed danger of tumour growth enhancement because of immunosuppression may not significantly be present. Despite the risk of tumour recurrence, liver transplantation gives worthwhile survival with the chance of cure for some and in others, considerable palliation with prolonged survival.

Humans↗

Soluble HLA antigens in the circulation of liver graft recipients.

Human liver allografts deliver soluble class I (HLA-A and -B) transplantation antigens into the recipients' circulation. These molecules are detectable in recipient serum shortly after transplantation and they persist at high concentration for as long as the liver graft functions. Levels of graft-derived antigens in the recipient serum and self antigens in donor serum are comparable. Kinetic studies of these soluble antigens in donor and recipient show that donor antigens are continuously exported by the transplanted liver, while in the recipient, self antigens are derived from liver and other sources. At least two molecular forms of soluble HLA-A and -B antigens are present in sera from donors, recipients, and normal individuals. One form with m.w. approximately 50 kd seems to be a soluble monomer associated with beta 2-microglobulin, while the other forms of higher m.w. may be aggregates and/or complexes. Monitoring of these antigens in transplant recipients may be a useful indicator of graft pathology and function.

HLA-A Antigens↗