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Biomedical subjects

D Petty

Publications and source records attributed to D Petty.

9 recordsLinked to original sources

Comparative physiological responses to stressors in animals.

1. The species-specific experimental response to stressors (SSERTS) analysis has been applied to a number of species under varied short and long term conditions. 2. The measure provides quantitative data relating to the physiological responses of animals when exposed to stressors and results are presented comparing these for different methods of immobilization, euthanasia, etc. at intra- and inter-species level. 3. It is suggested that the SSERTS measure is of greater value for measuring the responses of animals to stressors than is the measurement of the concentration of single blood variables.

Animals

A drug usage review of omeprazole.

A drug use review of omeprazole was carried out at two centres in the Yorkshire Region from December 1990 to April 1991. Data collection documents were used and 66 patients in total were audited. Thirteen patients (19.7%) were treated for indications outside the product licence and 18 patients (27.3%) were treated for longer than 8 weeks. Twenty-eight patients (42.4%) received 40 mg daily. Fifty-one patients (77.3%) had received previous therapy with H2-receptor antagonists and in 33% of these patients it was at an inadequate dose or for an inadequate period of dosing or both. The results indicate a need for a prescribing policy for omeprazole.

Dose-Response Relationship, Drug

An inexpensive computer-aided system for quantitative echocardiography.

A comprehensive system has been developed to quantitatively analyze standard M-mode pediatric echocardiograms. It utilizes relatively inexpensive hardware together with a telephone coupling to a time-sharing computer. A complete patient report on the study is printed out upon completion, and all the data are digitally stored for future research computations. Initial and operating costs for this system are significantly less than for any comparable one available.

Diagnosis, Computer-Assisted

Specific removal of antibody by extracorporeal circulation over antigen immobilized in collodion-charcoal.

Studies were undertaken to determine whether BSA immobilized in collodion membranes adherent to activated charcoal particles, would be capable of specifically removing circulating BSA antibody in vitro and in vivo in an extracorporeal system in dogs. Up to 59-8 mg of BSA were retained in collodion membranes adherent to small particles. In vitro studies demonstrated that immobilized BSA could specifically reduce BSA binding activity from circulating antisera. For in vivo studies, an extracorporeal circulation system was established and arterial blood was circualted through a continuous flow celltrifuge in which plasma was separated from formed elements of the blood. Only plasma was circulated over the BSA collodion-charcoal immunoadsorbent. Anti-BSA and anti-HSA atibodies were passively infused into dogs and, after an equlibration period of 12 or 15 min, plasma was passed over the BSA collodion-charcoal immunoadsorben. Plasma exhibited a sharp reduction in BSA binding over the next 30-60 min with only slight reduction in anti-HSA binding the same period. Dogs, actively immunized to BSA and HSA, were also treated by extracorporeal plasma perfusion over BSA collodion-charcoal. A specific decline in BSA binding of sera, was again observed with minimal changes in HSA binding. A post-perfusion rebound of BSA binding was observed which reached pre-perfusion levels after 6-8 days. A second treatment during the rebound period also resulted in a specific decline in BSA binding with a similar pattern of antibody rebound. There were no significant changes in I-labelled BSA recorded on the charcoal before and after in vivo procedures and no signifcant alterations in haematocrit, serum sodium, potassium, calcium, magnesium or creatinine levels before and after the procedures. These data suggests that antigen-coated charcoal may specifically withdraw circulating antibodies in vivo with minimal release of the entrapped antigen and little alteration in the host's haematological and biochemical status.

Animals

Degradation of circulating DNA by extracorporeal circulation over nuclease immobilized on nylon microcapsules.

Studies were undertaken to determine whether deoxyribonuclease I, (DNase I) once immobilized on activated nylon microspheres, would be capable of degrading circulating DNA in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 4.73 mg of Dnase I. In vitro studies showed that DNase I immobilized on microspheres degreded a significant percentage of 125I-native DNA (nDNA) within 15 min. Mongrel dogs were injected with 125I-nDNA and a variation in initial t 1/2 in individual animals was observed. Therefore, for experimental studies, 125I-nDNA was injected and decay was recorded during a control period in which untreated microcapsules were utilized in the extracorporeal system. DNase I microspheres were then introduced into the extracorporeal circuit which resulted in an acceleration of degradation of acid precipitable 125I-nDNA. When 200 mug of unlabeled DNA with 125I-nDNA was injected, a similar augmentation of DNA degradation was noted after extracorporeal circulation over DNase I microcapsules. This effect could not be attributed to release of DNase I from the microspheres since no 131I-DNase was detected in the serum or organs of the dogs at the conclusion of the experiments. 125I-nDNA:anti-DNA complexes were passively injected into dogs and after a similar control period of circulation over untreated microcapsules. DNase I microspheres were introduced. Results showed a rapid acceleration in the degradation rate of 125I-nDNA:anti-DNA complexes precipitable with (NH4)2SO4. Extracorporeal circulation over nylon microspheres resulted in no significant alteration of the host's hematocrit or platelet count, and little residual cellular debris on the microcapsules. These data suggest that DNAase immobilized on nylon microspheres may have a potential role in the specific therapy of systemic lupus erythematosus, when it is desirable to hydrolyze DNA circulating free or in combination with antibody.

Animals

Specific extraction of antigen in vivo by extracorporeal circulation over antibody immobilized in collodion-charcoal.

A novel extracorporeal immunoadsorbent is described in which anti-bovine serum albumin (anti-BSA) was entrapped in collodion membranes adherent to activated charcoal particles. This immunoadsorbent was capable of specifically removing circulating BSA in vitro and in vivo in an extracorporeal system in dogs. In preparation of the immunoadsorbent, up to 81.2% of added anti-BSA was retained on collodion-charcoal. In vitro circulation studies demonstrated that anti-BSA collodion-charcoal removed 812% more 125I-BSA than control colloidon-charcoal. For in vivo studies, an extracorporeal circulation system was established and arterial blood was passaged through a continuous flow celltrifuge wherein plasma which was separated from formed elements of the blood was circulated over anti-BSA and control rabbit gamma-globulin collodion-charcoal. 125I-BSA was passively infused into mongrel dogs, and plasma was then circulated over extracorpeal immunoadsorbents for 2 hr. Results showed up to 896% greater uptake of circulating 125I-BSA on the charcoal containing immobilized anti-BSA compared to control charcoal. There was no evidence of release of anti-BSA from the immunoadsorbent since 125I-anti-BSA cpm on the charcoal before and after the experiments were unchanged. In addition, there were no significant alterations in hematocrit, leukocyte counts, serum sodium, potassium, calcium, magnesium, or creatinine levels before and after in vivo procedures. These data suggest that this immunoadsorbent consisting of anti-BSA immobilized in collodion membranes adherent to charcoal particles may specifically withdraw circulating antigens in vivo with minimal release of entrapped antibodies and no significant alteration in the host hematologic and biochemical status.

Animals

Specific removal of bovine serum albumin (BSA) antibodies in vivo by extracorporeal circulation over BSA immobilized on nylon microcapsules.

Studies were undertaken to determine whether BSA, once immobilized on activated nylon microspheres, would be capable of specifically removing circulating BSA antibody in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and, after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 34.5 mg of BSA. In vitro studies showed that BSA immobilized on microspheres removed a significant percentage of BSA-binding activity. For in vivo studies, an extracorporeal circulation system was established and mongrel dogs were then injected with anti-BSA and anti-HSA antibodies. After an equilibration period, BSA microspheres were introduced into the extracorporeal circulation system. After the insertion of BSA microcapsules, serum exhibited a sharp reduction in BSA binding over the next 15 min, with a more gradual diminution over the ensuing 60 to 90 min. There was no significant reduction in anti-HSA binding over the same time frame. This effect could not be attributed to release of BSA from the microspheres since no 125I-BSA was detected in the serum or organs of the dogs at the conclusion of the experiments. After extracorporeal circulation over nylon microspheres, there were only minimal changes in the host's hematocrit or leukocyte counts and no significant thrombotic material or cellular debris was recoverable on the capsules. These data suggest that antigen immobilized on nylon microspheres may specifically withdraw circulating antibodies in vivo with minimal release of its antigenic material and little alteration in the host's hematologic status.

Animals