Spontaneous reverse haemolytic plaque formation. I. Technical aspects of the protein A assay.
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Chemical Phenomena↗
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Chemical linkage of erythrocytes and viral antigen in the hemolysis-in-gel (HIG) test for viral antibodies.
The sensitivity of the hemolysis-in-gel (HIG) test with rubella antigen is not improved by chemical linkage of the virus to the erythrocytes, and after such modification, IgM specific antibodies are not detectable. In the influenza HIG test with tetraazotized o-dianisidine (TOD), chromic chloride and potassium periodate as coupling reagents, increased sensitivity was observed with allantoic fluid of infected eggs as antigen. If Tween-ether treated hemagglutinin is used in the HIG test, zones of hemolysis are detectable only after treatment of the erythrocytes with TOD, chromic chloride and potassium periodate.
Allantois↗
The demonstration of sIg, MHC and T cell antigens and Fc receptors on the lymphocyte surface by anti-globulin rosetting reactions: some technical considerations.
The previously shown marked difference in sensitivity of antiglobulin rosette formation and immunofluorescence was confirmed in detection of varying amounts of anti-Ig bound to B cells. The direct and indirect rosette method revealed twice the number of sIg+ cells shown by direct immunofluorescence (DIF), and at least an order of magnitude more antibody on the cell surface is necessary to detect the conventional B cells (shown by DIF) by indirect immunofluorescence compared with indirect antiglobulin (IARR) rosette formation. Variants of the sensitive IARR test were developed to reveal general lymphocyte, MHC class I and class II and T cell-specific antigens and Fc receptors using xenogeneic or allogeneic reagents. Sensitive indicator cells were used which form almost no rosettes with unsensitized lymphocytes although coated with IgG which would otherwise bind to the Fc receptor. The suggestion that chromic chloride treatment inactivates the relevant Fc determinants was supported by experiments showing the failure of IgG antibody-sensitized bovine RBC (standard Fc indicator cells) to form rosettes after treatment with chromic chloride.
Animals↗
A passive haemagglutination test for the detection of anti-nicotinic acetylcholine receptor antibodies.
A detergent-solubilised membrane protein (the nicotinic acetylcholine receptor) was coupled to red blood cells by the chromic chloride method. The bound receptor retained both antigenic activity and the ability to bind alpha neurotoxins. Coated cells were successfully used in a haemagglutination test to determine antibody titre and cross-reactivity of polyclonal and monoclonal anti-acetylcholine receptor antisera.
Animals↗
Rapid identification of proteins on flat surfaces, using antibody-coated metal oxide suspensions.
Suspensions of Fe3O4 (black), Fe2O3 (red), and Cr2O3 (green) were exposed to solutions of protein A, and then each to a different antiserum to one of the following human proteins: fibrinogen, high molecular weight kininogen (HMK), albumin or immunoglobulins (IgG). Test surfaces were patterns of human proteins adsorbed out of solutions or out of plasma, onto glass as well as onto polyvinylchloride slides. They were exposed to single or mixed suspensions of the treated oxides for about 30 s and rinsed. Adhesion of each oxide onto each matching protein of these patterned test surfaces resulted, thus identifying each protein by color.
Antibodies↗
Direct monoclonal antibody rosetting. An effective method for weak antigen detection and large scale separation of human mononuclear cells.
A direct monoclonal antibody rosetting technique is described which serves as a simple, reliable, and very sensitive method for the detection of surface antigens on human leukocytes. In this technique the discriminative monoclonal anti-leukocyte antibodies are directly coupled to ox erythrocytes (oxE) by use of CrCl3. The procedure can be applied to the effective separation of mononuclear cell subsets. By choosing a gradient of appropriate density labeled cells are either isolated in high purity or quantitatively eliminated. This technique proved to be particularly suitable for the large scale purification of autologous or allogeneic bone marrow transplants where either leukemic cells or T cells have to be completely eliminated without damaging sensitive stem cells.
Animals↗
Assays using red cell-labelled antibodies.
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Antibodies, Monoclonal↗
Rapid procedure for coupling protein antigens to red cells to be used in plaque assays, by prewashing in chromium chloride.
A rapid and efficient procedure is described for the coupling of proteins (protein A, ovalbumin, albumin and chicken gamma globulin) to sheep red blood cells (SRBC) to be used in antigen-specific or protein A plaque assays. This modification of the original procedure has three distinct features: prewash of the red cells with a low concentration of essentially freshly prepared CrCl3, use of a relatively high concentration of CrCl3 in the reaction mixture and a coupling time of only 4 min. Protein A plaque assays performed with such target cells have the same sensitivity as those employing red cells coupled with protein A according to the original procedure. Studies with hybridomas secreting antibody specific for a protein antigen showed that antigen-specific plaque assays employing target red cells coupled with the protein antigen according to the modified procedure have the same sensitivity as the protein A plaque assay. The modified procedure greatly facilitates cellular studies on antibody formation after immunization with protein antigens.
Animals↗
Bond versus rebond strengths of three luting agents for resin-bonded fixed partial dentures.
Recently, new luting materials have been claimed to have adhesion to metal and tooth structure. This study determined if rebonding the specimens affected their tensile bond strength. Ten samples each of Rexillium III metal cylinders (12 x 6.3 mm) were bonded and rebonded with Comspan Panavia and Super-bond materials. The film thickness was controlled with a micrometer device at 20 microns. The samples were stored for 24 hours in deionized water at 37 degrees C and were then thermocycled for 24 hours and tested for tensile failure on an Instron testing machine. A stereomicroscope was used to determine adhesive/cohesive failure. The results showed a significant difference at p greater than 0.01 in tensile bond strengths (bond versus rebond strength) for all three luting agents. Most of the failures were adhesive in nature.
Acid Etching, Dental↗
Glucose metabolism in glucose-intolerant older people during chromium supplementation.
The effects of chromic chloride (CrCl3) administered orally for 12 weeks to five elderly subjects with glucose intolerance were assessed. Pretreatment and posttreatment, the hyperglycemic clamp technique was employed to determine glucose utilization, beta-cell sensitivity to glucose, and tissue sensitivity to insulin. In addition, erythrocyte insulin binding was studied. Urinary chromium excretion increased approximately 5 fold indicating good compliance with supplementation. The oral glucose tolerance curves following supplementation were lowered from 60 to 120 minutes but only the 60-minute values were significantly lowered. In agreement with this was significantly increased glucose utilization during the hyperglycemic clamp studies. Tissue sensitivity to insulin, receptor affinity, and total insulin binding were unchanged by supplementation while beta-cell sensitivity to glucose increased following supplementation (P less than 0.04), and explained the increased glucose utilization. HDL and LDL and total cholesterol levels were slightly lower after chromium supplementation, but no change reached statistical significance. The LDL/HDL cholesterol ratio was unchanged. This study shows small but statistically significant effects of CrCl3 on carbohydrate metabolism. The clinical relevance of these effects, that is, their prophylactic or therapeutic significance, remains to be determined.
Aged↗
Inhalation toxicity of chromium dioxide dust to rats after two years exposure.
Rats were exposed by inhalation to chromium dioxide (CrO2) dust at design concentrations of 0, 0.5 (stabilized and unstabilized, respectively) or 25 mg m-3 (stabilized) for 6 h day-1, 5 days week-1 for 2 years. No dust-exposure-related pathological changes were observed, other than lung lesions, in all exposed rats. There were no significant differences in pulmonary response between unstabilized and stabilized CrO2 at the 0.5 mg m-3 exposure level. The lungs showed minute dust deposition in the alveoli adjacent to the alveolar ducts, but maintained an intact general architecture. The pulmonary responses satisfied the biological criteria for a nuisance dust. At 25 mg m-3, dust deposition was sharply confined to the alveoli in the alveolar duct region. Alveolar walls enclosing dust-laden macrophage (dust cell) aggregates were thickened with hyperplastic Type II pneumocytes and slightly collagenized fibrosis. Alveoli adjacent to the terminal bronchioles were lined with bronchiolar epithelium (alveolar bronchiolarization). In addition, lungs showed foamy macrophage response, cholesterol granulomas, alveolar proteinosis, and minute fibrotic pleurisy. These pulmonary lesions occurred predominantly in female rats. Of 108 female rats, six developed keratin cysts and two had cystic keratinizing squamous cell carcinoma (CKSCC). None of 106 male rats had either a keratin cyst or a CKSCC. The lung tumors developed from metaplastic squamous cells in the areas of alveolar bronchiolarization in the alveolar duct region. The lung tumors were well differentiated and devoid of characteristics of true malignancy. The CKSCC is an experimentally-induced, unique tumor type and is different from the type of spontaneous lung tumor seen in man or animals. The relevance to man of ths type of lung tumor appears to be negligible.
Administration, Inhalation↗
Radioactive chromic phosphate suspension: studies on distribution, dose absorption, and effective therapeutic radiation in phantoms, dogs, and patients.
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Absorption↗
Intraperitoneal chromic phosphate in ovarian cancer: risks and benefits.
Between March 1977 and December 1985, 59 patients were treated with intraperitoneal chromic phosphate at The University of Alabama Birmingham Hospitals and its affiliates. Twenty-seven patients received primary adjuvant therapy. Thirty-two patients were treated "secondarily" after tumor recurrence or after a "positive" second-look laparotomy. Associated morbidity was noted to be 12% with reoperation required in 7%. Early stage and grade tumors demonstrate a good prognosis. Little, if any, benefit was demonstrated in "secondary" therapy of advanced stage and grade tumors.
Chromium↗
Bowel perforation associated with intraperitoneal chromic phosphate instillation.
Intraperitoneal chromic phosphate is widely used as adjuvant therapy in the treatment of early-stage ovarian epithelial carcinoma. Delayed bowel injury is an infrequently observed complication of chromic phosphate administration. This report presents a case of colon perforation which occurred 4 months after treatment with intraperitoneal chromic phosphate for stage IB ovarian papillary serous cystadenocarcinoma.
Chromium↗
Intraperitoneal P-32 is not an effective consolidation therapy after a negative second-look laparotomy for epithelial carcinoma of the ovary.
Thirty-four patients with epithelial carcinoma of the ovary were entered into a trial of adjuvant intraperitoneal P-32 following induction chemotherapy and a negative second-look laparotomy. The breakdown by initial Stage was Stage IC, 5; Stage II, 3; Stage III optimal, 22; and Stage III suboptimal, 4. Previous treatment consisted of 4-12 cycles (median 6) of cisplatin or carboplatin-based combination chemotherapy. Fifteen millicuries of P-32 were instilled via a Tenckhoff catheter placed at the time of second-look laparotomy. Because of a 22% incidence of bowel injury in the first 23 patients, the P-32 dose was reduced to 12 mCi in the last 11 patients. To date, there have been no bowel injuries at the lower dose. Eighteen of the 34 (53%) patients have relapsed with a median time to relapse of 20 months and a median follow-up for all patients of 31 months. There has been no difference in the relapse rate between a dose of 12 and 15 mCi. Intraperitoneal P-32 does not appear to reduce the relapse rate following a negative second-look laparotomy. The incidence of bowel injury is dose dependent and is higher than that seen in patients treated as an adjuvant following initial surgery without subsequent chemotherapy or second-look laparotomy.
Adult↗
pH shifts and precipitation associated with metal ions in tissue culture.
Recently there has been interest in tests to assess the physiological response to surgical implant corrosion products. Both cell culturing in metal-bearing solutions and intramuscular injection of such solutions have been carried out. This paper examines the effects of the constraints of multicomponent equilibrium conditions on the characteristics of the solutions used in these biocompatibility tests. It is demonstrated that, unbuffered, they will have pH values shifted from neutral and that, in the buffered state, these solutions may contain both dissolved metal ions and insoluble hydroxides. The implications of these characteristics for the interpretation of the results of biocompatibility tests are discussed.
Animals↗
Polyester film strips coated with photographic gelatin containing immobilized glucose oxidase hardened by chromium(III) sulphate.
Glucose oxidase was immobilized into photographic gelatin hardened by chromium(III) sulphate. The enzyme-gelatin mixture was coated on polyester film strips which allowed easy and simple handling during assays. The effect of gelatin and cross-linker concentrations on water content and enzymatic activity was studied. The effect of pH during immobilization and that of incubation temperature on maximum activity were examined. Enzyme leakage tests were carried out during reuse number studies. Consecutive use of strips followed by washing and resting between uses were found to affect the reuse number. A maximum immobilization of 68% was reached under optimal conditions. Mechanical stability and leakage were found to be functions of gelatin and cross-linker concentrations. Photographic gelatin was found to have many capabilities with extraordinary characteristics as a carrier on immobilization.
Biocompatible Materials↗
Effect of chromium salts on invertase immobilization onto carboxymethyl-cellulose-gelatine carrier system.
The carboxymethylcellulose-gelatine carrier system was investigated for invertase immobilization. Chromium (III) acetate, chromium (III) sulphate and potassium chromium (III) sulphate were used as cross-linking agents. Effect of carboxymethylcellulose-gelatine ratio and cross-linker concentration on immobilized enzyme activity were analysed. Reusability of immobilized enzyme was also investigated. Maximum immobilized enzyme activities were obtained with cross-linkers chromium (III) sulphate (0.004 mol dm-3) and potassium chromium (III) sulphate (0.001 mol dm-3) for a carrier composition of carboxymethylcellulose-gelatine ratio 0.111 (w/w) as 78%.
Carboxymethylcellulose Sodium↗