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Biomedical subjects

D J Cook

Publications and source records attributed to D J Cook.

At least 289 records · Page 16Linked to original sources
PubMed1987

The flow cytometry crossmatch in kidney transplantation.

1. Positive FCXM reactions were associated with sensitization in transplants with negative cytotoxic crossmatches. Recipients of regrafts, females, particularly those with previous pregnancies, and recipients with historical cytotoxic antibody reactivity were more likely to have FCXM detectable antibodies. 2. Primary nonfunction grafts were associated with a positive FCXM, but predominantly in those transplants involving female, older, or nontrauma donors. Nearly 40% of the FCXM positive transplants of these organs did not function during the first month posttransplant 3. Low 3-month graft survival rates were associated with a positive FCXM reaction, but once again this was seen with female, older, and nontrauma donor transplants. In addition, approximately 40% of FCXM positive transplants involving older or nontrauma donors that did survive had poor graft function at 3 months.

Antilymphocyte Serum↗
PubMed1987

ABO incompatibility in cadaver donor kidney allografts.

We have found the ABO barrier does appear to remain intact in clinical kidney transplantation, as evidenced by a 4% 1-year graft survival in 25 cadaver donor, ABO-incompatible allografts. The one long-term surviving graft could have been a case of an A2 kidney and a B recipient, but this could not be determined. Although these grafts were the result of errors at a number of different points, most could have been avoided if a red cell crossmatch had been performed at the time of transplant. The fact that these transplants rarely occur should not overshadow the possibility that they could be avoided by the implementation of such a simple procedure.

ABO Blood-Group System↗
PubMed1987

Anasarca due to pulmonic valve regurgitation with low pulmonary vascular resistance.

A 57-year-old woman underwent pulmonic valvotomy for congenital pulmonic stenosis. She developed severe pulmonic insufficiency, secondary tricuspid regurgitation, and anasarca in spite of a normal pulmonary artery pressure. Insertion of a pulmonary valve prosthesis and tricuspid valve plication reversed all clinical symptoms and signs of this rare complication of pulmonary valvotomy.

Edema↗
PubMed1987

Fluorophotometric study of intravenous carbonic anhydrase inhibitors in rabbits.

The ability of fluorophotometry to measure the time course of changes in aqueous humor flow in rabbits was evaluated by measuring the effect of intravenous carbonic anhydrase inhibitors on aqueous humor flow determinations. The abrupt changes in aqueous humor flow which were found by fluorophotometry agreed well with the expected changes in aqueous humor flow calculated from the time course of the intraocular pressure. Therefore, it was concluded that fluorophotometry could measure the time course of changes in aqueous humor flow in rabbits. Furthermore, it was suggested that the initial abrupt changes in aqueous humor flow after the administration of a carbonic anhydrase inhibitor were induced by the base content of the drug, followed by a more gradual decrease in aqueous humor flow caused by the direct effect of the drug on aqueous humor formation.

Animals↗
PubMed1986

Serum antibody reactivity of broadly sensitized patients with HLA-matched peripheral blood T lymphocytes.

The sera of 45 hypersensitized patients with more than 90% panel reactive antibodies were tested for reactivity against peripheral blood T lymphocytes from 7 donors matched for HLA-A,B antigens. The target cells were phenotypically homozygous HLA-A1,B8 or A2,B44. Tests for lymphocytotoxic antibodies were essentially negative except for one target cell in which 10 of 25 sera were positive. More positive reactions were detected by flow cytometry, and the proportion of positive specimens ranged from 15% to 48% with the different target cells. Most positive reactions involved the HLA-A2 and B44 antigens, in which heterogeneity within the serologically defined specificities has been described. The positive reactions were further evaluated by testing the effect of purified soluble HLA molecules on the binding of antibodies to the HLA-marched targets. Purified HLA produced a detectable inhibition of antibody binding in the majority of the serum-target combinations studied. These results document that anti-HLA antibodies can still react with HLA-matched lymphocytes, which may be due to the recognition of subtypes of the known serologically defined specificities.

Binding, Competitive↗
PubMed1986

HLA-DR associated immune responsiveness.

1. HLA-DR1-positive recipients were found to enjoy superior graft survival when compared with DR1-negative patients (72.5% versus 66.5%, p less than 0.00001) in kidneys transplanted since 1980. These patients had the highest graft survival rates in first cadaver, cadaver regraft, and living-related donor transplants. This was seen with patients regardless of the degree of DR-antigen matching. Within one day of the transplant, this advantage of DR1 patients was detectable when graft function was examined. 2. In white recipients, DR1-positive patients had the best graft survival rates. In black recipients, DR1-positive recipients also had the best graft survival rate; however, DR4-positive recipients also had very good graft survival. Whether or not these patients represent a unique population is unclear at this time. 3. In kidneys transplanted since 1983, DR1-positive patients again had the best graft survival rates. This was the case with and without the use of CsA for immunosuppression. DRw9-positive patients had the poorest graft survival rate (52%) in patients without CsA and the best survival rate (84%) of patients treated with CsA; however, because of the low number of patients, these survival rates were not significantly different from the average. 4. In the analysis of transplants performed since 1980, no association between the DRw6 antigen and low graft survival was noted. When the analysis was restricted to grafts transplanted since 1983, DRw6-positive recipients had the poorest graft survival rates. This was true both with and without the use of CsA. No beneficial effect of DRw6 in the kidney donor was seen regardless of the recipient's DR type.

Graft Survival↗
PubMed1986

Crossmatching with B and T cells and flow cytometry.

1. Hyperacute rejections occurred in 0.6% of 19,415 first cadaver donor grafts and 1.9% of 4,326 regrafts. When grouped into those without preformed cytotoxins, 0.5% first grafts and 1.3% of regrafts had hyperacute rejection. Among patients with cytotoxins 1.3% of first grafts and 2.6% of regrafts had hyperacute rejections. 2. A total of 923 first cadaver donor transplants and 238 multiple transplants were crossmatched by 6 variations of microcytotoxicity tests: standard, long 4-hour incubation, B lymphocytes at 4 degrees C and 37 degrees C and T lymphocytes at 4 degrees C and 37 degrees C. All crossmatching was done in one laboratory. 3. For first cadaver donor transplants, 178 patients with long positive crossmatches and 56 patients with T warm positive crossmatches had a significantly lower survival rate than crossmatch negative patients. Those with short positive (weak), B warm, B cold, and T cold positive crossmatches had the same graft survival as crossmatch negative patients. 4. In regrafted patients from cadaver donors those with a short and T warm positive crossmatches had lower graft survival than crossmatch negative patients. 5. Preformed T warm cytotoxins were associated with lower graft survival in first grafts and B warm cytotoxins were associated with lower graft survival in regrafts. 6. Eight patients with T warm positive crossmatches were successfully transplanted (function at 3 months) after they were shown to have IgM antibodies removable by 2-ME treatment. 7. A total of 136 patients were tested by FCXM at the time of transplant on a retrospective basis. Although all patients were crossmatch negative by the T warm tests, 24 were FCXM positive.(ABSTRACT TRUNCATED AT 250 WORDS)

Antilymphocyte Serum↗
PubMed1986

Original disease of the recipient.

1. The influence that a patient's original disease had on the outcome of kidney transplantation was small when recent transplants (1983 to present) were examined. A difference of only 5% was seen in one-year graft survivals of first cadaver donors. The average one-year survival was 70%; patients with pylonephritis having the best (75%) and SLE patients the worst (65%) survival rates among the major disease categories. 2. There was little difference observed in patient survivals or functional graft survivals in first cadaver transplants among patients with different original diseases. This was also the case with cadaver regrafts; with the exception of polycystic kidney patients who had quite poor graft survival (41% at one year) with regrafts. Pretransplant blood transfusions resulted in increased cadaver graft survival; however the low number of nontransfused patients in many disease categories presented difficulties in examining this effect. 3. The use of cyclosporine resulted in increased cadaver graft survival in all disease categories. One-year cadaver graft survival of cyclosporine-treated patients averaged 75% compared to 63% with noncyclosporine-treated patients. A beneficial effect of cyclosporine use was not consistently seen in transplants involving living-related donors, although perhaps larger numbers of patients are required in order to confirm this observation. 4. Graft survival in diabetic patients was quite good in this analysis of recent transplants. First cadaver one-year graft survival in diabetics was only 4% below the overall average and 2% less with cyclosporine. Patients with both juvenile (75% one-year graft survival) and adult-onset (78% one-year graft survival) forms of the disease had good graft survival when cyclosporine was used for immunosuppression.

Diabetes Mellitus↗
PubMed1986

Quantitative analysis of platelet surface HLA by W6/32 anti-HLA monoclonal antibody.

Class I molecules of human major histocompatibility complex (HLA) are the most important antigenic system in determining the survival of transfused platelets in alloimmunized patients. Platelets with reduced expression of a specific type of HLA antigen may escape specific anti-HLA antibody-mediated destruction. By using 125I-labeled Fab fragments of W6/32 anti-HLA monoclonal antibody and competitive protein binding assays, we measured the range of total HLA concentrations on platelets. In 12 individuals examined, the mean number of HLA-A, B, and C molecules per platelet was 81,587 +/- 20,016 (mean +/- SD); its range was between 54,782 to 116,185 molecules per platelet. After treatment with chloroquine, 79.9 +/- 7.0% (mean +/- SD, n = 6) of HLA antigens were removed from platelets as determined by binding of 125I-W6/32 Fab. A similar result was obtained when HLA antigens on chloroquine-treated platelets were evaluated with immunofluorescence flow cytometry. In contrast, chloroquine treatment did not remove integral membrane protein such as P1A1 antigens on platelets. The presence of HLA antigens in the chloroquine eluate of platelets could be demonstrated to contain HLA antigens similar in mol wts to intact class I molecules by an immunoblotting technique. These data suggest that 70% to 80% of platelet HLA antigens are adsorbed and that such HLA antigens are not proteolytic products of integral membrane class I molecules. The origin of the adsorbed platelet HLA-antigens remains to be determined.

Adult↗
PubMed1986

Dexamethasone, D-penicillamine, and glaucoma filter surgery in rabbits.

A study was made in rabbits of the effect of topical dexamethasone ointment, .05%, and either subconjunctival or intraperitoneal D-penicillamine on the duration of function of glaucoma filtering surgery. The drugs were tested alone and in combination. Intraperitoneal D-penicillamine was not effective, either alone or combined with topical dexamethasone. Topical dexamethasone ointment alone and subconjunctival D-penicillamine alone significantly prolonged the duration of function of the filter surgery; however, when combined, no additional effect was observed. It was concluded that the institution of therapy with both drugs immediately after glaucoma filtering surgery was not the optimal temporal sequence for combining the two modes of therapy.

Administration, Topical↗
PubMed1985

A fluorophotometric study of the effect of argon laser trabeculoplasty on aqueous humor dynamics.

Fluorophotometry and tonography were used before and after argon laser trabeculoplasty to measure aqueous humor dynamics in 15 eyes of 14 patients. A new fluorophotometric method used to measure true outflow facility showed that it increased from a mean pretreatment value of 0.016 microliter/min/mm Hg to a mean posttreatment value of 0.075 microliter/min/mm Hg. Similarly, total outflow facility, measured tonographically, increased from 0.112 microliter/min/mm Hg to 0.151 microliter/min/mm Hg. Uveoscleral flow decreased after laser therapy; however, this was secondary to the decrease in intraocular pressure. No effect was found on the rate of aqueous humor production. We concluded that the primary effect of argon laser trabeculoplasty was to increase true outflow facility, thereby decreasing intraocular pressure.

Aqueous Humor↗
PubMed1985

Purified HLA antigens to probe human alloantibody specificity.

HLA class I antigens were purified in sufficient quantities to probe the antigen specificity of lymphocyte and platelet antibodies. Purification of HLA was achieved by affinity chromatography using the monoclonal W6/32 antibody that recognizes a nonpolymorphic determinant of HLA-A,B,C molecules. Pooled platelets from a large number of donors were used as source of antigen. A highly purified HLA preparation was obtained that produced a dose-dependent inhibition of the binding of the W6/32 antibody to lymphocytes as measured by flow cytometry. The binding of monoclonal antibodies to T-lymphocyte antigens or to HLA class II antigens was not affected. The purified HLA also inhibited the binding of lymphocyte alloantibodies from renal transplant patients, providing a direct and definitive way to probe HLA specificity. HLA also inhibited the binding of the same antibodies to platelets but it did not interfere with the binding of alloantibodies to the platelet-specific PLA1 antigen. This preparation, therefore, can conclusively probe the HLA specificity of both alloantibodies for clinical investigation purposes and monoclonal antibodies for screening purposes, and has the potential of becoming a reagent for routine use in clinical and research laboratories.

Antibodies, Monoclonal↗
PubMed1984

The role of carbamino compounds in histological staining.

The effects of high CO2 concentration on tissue staining with buffered eosin, methylene blue and azure A were investigated to determine if carbamino compound formation could alter dye binding. Only in the case of eosin staining were the differences in results with high and low CO2 concentrations compatible with the formation of carbamino compounds. The differences observed with basic dyes were statistically significant but could not be accounted for by carbamino compound formation.

Animals↗
PubMed1983

Gastric emptying in normal subjects--a reproducible technique using a single scintillation camera and computer system.

The gastric emptying of a mixed solid and liquid meal was assessed in 24 normal subjects using a single camera/computer system which allowed continuous monitoring of both solids and liquids. It was shown that variation in tissue attenuation caused by the changing depth of radionuclide within the stomach accounted for large errors in the measurement of gastric emptying (alteration in 50% emptying time of up to 65%). A technique for the correction of attenuation is described which used factors derived from a lateral image of the stomach. In all subjects, solid emptying was slower than liquid emptying and was characterised by a delay (lag period) which was followed by linear emptying. Liquid emptying usually followed a single exponential pattern. The effect of physiological changes induced by increasing the calorie content of the liquid component of the meal was assessed by giving either water, 10% dextrose or 25% dextrose. Liquid emptying was slowed and the lag period of solid was prolonged as the calorie content increased. Reproducibility was assessed in 19 subjects. For the three groups studied (water, 10% dextrose, 25% dextrose) the day-to-day variation in gastric emptying was not significant for any measured parameter, while statistically significant differences were present in solid and liquid emptying between subjects and groups.

Adult↗
PubMed1983

Abnormalities of gastric emptying in obese patients.

The pattern of gastric emptying in 15 obese patients and 11 control subjects has been assessed using a double isotope technique for measuring solid and liquid emptying with a scintillation camera. In all studies solid emptying was characterized by a lag period (before food enters the duodenum) followed by linear emptying. Liquid emptying was faster than solid and was non-linear. In obese patients solid emptying was delayed due to prolongation of the lag period, and the duration of the lag period correlated with excess body weight. There was no significant change in liquid emptying in obese patients. In control subjects no relationship between gastric emptying rates and body weight was apparent.

Adult↗
PubMed1982

Measurement of gastric emptying after gastric bypass surgery using radionuclides.

The pattern of gastric emptying has been assessed after gastric bypass surgery using a double isotope technique for measuring solid and liquid emptying with a scintillation camera. Eleven control subjects and 12 patients, 12 months post-gastric bypass, were studied. Stomal and gastric pouch size were assessed at endoscopy. Solid emptying was slower and liquid emptying was more rapid after gastric bypass surgery. Initial rapid emptying of solid occurred in the 4 patients with the smallest pouch diameters. There was no correlation between stomal size and rates of solid or liquid emptying nor between the weight loss produced by the operation and the rates of solid or liquid emptying, stoma or pouch size.

Adult↗