PubMed Health⌕ Search

Biomedical subjects

K M Rigg

Publications and source records attributed to K M Rigg.

27 records · Page 2Linked to original sources
PubMed1993

Production of immunosuppressive factors by a cultured tumour cell line and their effect on lymphocyte proliferation and cell cycle response.

Immunosuppression observed in patients with malignancy may be due to factors released by tumour cells. Medium conditioned by COLO 205 cells was found to inhibit mitogen-stimulated lymphocyte proliferation. Examination of CD25 and Class II MHC induction on PBMC incubated in complete, or COLO 205 conditioned, medium was not significant. The prevalence of lymphocytes in the S-phase of the cell cycle was enhanced after mitogenic stimulation and addition of COLO 205 conditioned medium. This was balanced by a concomitant fall in proportion of cells in the G0/G1 phases of the cell cycle. The immunosuppressive properties of COLO 205 conditioned medium was abrogated by heating to 60 degrees C for 30 min and by digestion with trypsin. Fractionation of the medium by gel filtration yielded two immunosuppressive fractions with relative molecular weights of 60,000 and below 20,000. It was concluded that cultured COLO 205 cells produce immunosuppressive protein/peptide factors which block cell proliferation during DNA synthesis. These factors fail to prevent upregulation of membrane-associated markers of cell activation.

Cell Cycle↗
PubMed1992

Surgical aspects of chronic peritoneal dialysis in the neonate and infant under 1 year of age.

Since 1982 eight patients under 1 year of age with end-stage renal failure have been treated by chronic peritoneal dialysis (CPD) following insertion of an abdominal Tenckhoff catheter. We routinely perform a partial omentectomy now, and in males undertake bilateral exploration of the groins at the time of catheter insertion, with herniotomy or ligation of the patent processus vaginalis as required. Up to January 1990, 19 straight double-cuff catheters had been inserted with a total follow-up of 244.5 patient months. The median age at the initial catheter insertion was 14.6 weeks (range, 2 days to 11 months) and the median weight was 3.89 kg (range, 2.2 to 5.5). Peritonitis was the most common complication, with 46 episodes, representing one episode of peritonitis per 5.3 patient months on dialysis. The frequency of peritonitis has decreased in the last 6 months since all patients have been dialysed by two caregivers. The present rate of peritonitis is 1 episode per 10 patient months on dialysis. One patient has died of septicemia secondary to associated congenital abnormalities, one patient has regained renal function, and two patients have been transplanted, one successfully. Five patients are currently dialysing via their abdominal Tenckhoff catheters and awaiting transplantation. We conclude that neonates and infants under 1 year of age can be treated satisfactorily by CPD to enable successful preparation for transplantation later in childhood.

Catheters, Indwelling↗
PubMed1991

Alterations in circulating lymphocyte number and function after circulation through colorectal carcinomas.

Thirty-six patients undergoing curative resection for colorectal cancer were studied to determine the effect of the tumor on lymphocytes circulating through it. In the venous blood draining the tumor, there was an increased percentage of natural killer (NK) cells (p = 0.001), no difference in overall NK cell function, and decreased T-lymphocyte activation (p = 0.035) and proliferation (p = 0.002) compared with the lymphocytes in the arterial blood supplying the tumor. There were no significant differences in the control group of 16 patients. Local effects of colorectal cancer may include the ability to down-regulate T and NK cell function while increasing the number of NK cells. Means of enhancing antitumor activity therapeutically in an adjuvant setting, possibly through the portal vein during surgery, need to be considered, especially in the light of the immunosuppressive effects of surgery.

Aged↗
PubMed1990

Late perfusion. A simple remedy for renal allograft primary nonfunction.

Primary nonfunction in renal allografts makes the diagnosis of allograft dysfunction more difficult and may effect long-term graft survival. The prevention of primary nonfunction by a reperfusion technique has been assessed in a prospective analysis of 145 consecutive renal transplants performed in a single center. All kidneys were retrieved using an in situ perfusion method, and all but 13 recipients received a standardized immunosuppressive protocol with cyclosporine. The first 106 transplants were performed without the benefit of any additional perfusion, and the incidence of primary nonfunction was 57.5% in these patients. The last 39 kidneys received additional perfusion with kidney perfusion fluid immediately prior to implantation (late perfusion). In the latter group, the incidence of primary nonfunction was 30.8% (P = 0.007). Using logistic regression analysis, only three factors were found to be associated with primary nonfunction: immunosuppression with cyclosporine (P = 0.01), a second warm ischemia time of greater than 35 min (P = 0.002), and late perfusion (P = 0.003). In this study, the use of late perfusion alone has reduced the incidence of primary nonfunction by almost one half. The technique is simple, safe, inexpensive, and effective. Its routine use is now advocated in all renal transplants.

Cyclosporins↗
PubMed1989

A flow cytometric technique for simultaneous analysis of human mononuclear cell surface antigens and DNA.

A method for dual staining of mononuclear cells for lymphocyte phenotypic markers and DNA is described. The cells were stained with fluorescein-conjugated monoclonal antibodies and then rendered permeable to propidium iodide using saponin. Propidium iodide stains DNA and, using flow cytometry, cell cycle analysis of individual lymphocyte subpopulations can be determined. Saponin acts within 1 min, preserves expression of surface antigens and is effective at all concentrations from 0.001% to 1%. This technique is simple, rapid and gives reproducible results.

Antigens, Surface↗