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Biomedical subjects

A Mackie

Publications and source records attributed to A Mackie.

At least 37 records · Page 2Linked to original sources

Identification of several cyclosporine binding proteins in lymphoid and non-lymphoid cells in vivo.

The immunosuppressant cyclosporine A (CSA) has been shown to bind to the ubiquitous cellular protein, cyclophilin, and to inhibit its rotamase activity. In the present study, 3H-cyclosporine diazirine analogue was used to photolabel viable human cells of lymphoid and fibroblast origin in order to identify the intracellular targets for the drug. While cyclophilin was strongly labeled in situ, additional minor cyclosporine-protein complexes of 25, 40, 46 and 60 kDa were identified in the T cell leukemia cell line Jurkat. These proteins bound specifically, since only active CSA but not inactive CSH or FK506 competed for binding. Photolabeling of MRC5 cells, a CSA resistant human fibroblast cell line, revealed a 25 kDa complex as the major product, while the 46 and 60 kDa bands were not detectable and cyclophilin labeling was only faint, even though both MRC5 and Jurkat cells contain similar cyclophilin concentrations. Thus, our data suggest that the intracellular targets of CSA and/or the accessibility to cyclophilin varies considerably in drug sensitive and resistant cell types, which may contribute to explaining the lymphocyte selectivity of the drug.

Amino Acid Isomerases↗

Evaluation of the accuracy of a pharmacokinetically-based patient-controlled analgesia system.

Bone marrow transplant patients having severe, prolonged oral mucositis pain (expected to last for one to three weeks) used a computer-controlled infusion system to self-administer morphine for pain control. Individual patient pharmacokinetic information, derived from a pretreatment bolus morphine dose, was used in a new bolus-elimination transfer algorithm to produce rapid adjustments of steady plasma morphine concentrations when the patient requested more or less drug. We evaluated the performance characteristics (bias and precision) of this pharmacokinetically based patient-controlled analgesic infusion system (PKPCA) in a group of 15 cancer patients over six to 14 days. Although we found a three- to fivefold pharmacokinetic variability in the tailoring morphine dose data, the PKPCA system was free of systematic bias (insignificant overall prediction error) during the patient-controlled infusions in this study population. The absolute prediction error was 19.9% for the group on the first study day and 25.6% over the entire study period (aggregate results; 6-14 days of continuous use). Two-thirds of the patients exhibited no bias throughout the study period, and individual bias in the others was symmetrically distributed (three patients with underpredictions and two overpredicted). Magnitude of prediction error during the patient-controlled morphine infusions was not related to the magnitude of pharmacokinetic deviation of individual subjects from group parameters. Our results indicate that this PKPCA system provides accurate control of plasma morphine concentration when used by patients to self-administer opioid for prolonged pain relief continuously over 1 to 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesia, Patient-Controlled↗

Linkage analysis of maturity-onset diabetes of the young (MODY): genetic heterogeneity and nonpenetrance.

We have analyzed the inheritance of maturity-onset diabetes of the young (MODY) on chromosome 20 in a large multigeneration family, the R.-W. family, and in two other MODY families. Of the four branches of the R.-W. pedigree which have been studied, two have documented early onset of non-insulin-dependent diabetes mellitus (NIDDM), while there is no evidence of early onset in the other two branches. The early-onset branches have apparently inherited the same D20S16 allele from the affected parent, while another D20S16 allele was inherited in the two branches without evidence of early onset. A test for homogeneity, the M-test, using the results of two-point linkage analysis with D20S16 indicates heterogeneity between early- and late-onset branches of the R.-W. family (P less than or equal to .014). In addition, analysis strongly suggests that MODY as expressed in the EDI and WIS families is unlinked to loci on chromosome 20 (P less than or equal to .018-.004). Comparable results are seen when the data are analyzed by the HOMOG program. Three polymorphic loci-D20S16, D20S17, and ADA--show no recombination with the MODY locus when two-point linkage analysis is used in the early-onset branches of the family. The multipoint lod score in the early-onset branches of the R.-W. family is 10.16, with the most likely location being between D20S4 and D20S17. Multipoint linkage analysis using the CHROMPICS option of the program CRI-MAP has been used to follow inheritance of the MODY disease locus. This analysis has identified two cases of possible nonpenetrance in the early-onset branches of the family (odds of at least 156:1), as determined by the appearance of apparent isolated double crossovers at the MODY locus in these unaffected individuals.

Adolescent↗

Effect of giving enrofloxacin in the diet to pigs experimentally infected with Actinobacillus pleuropneumoniae.

Three groups of 16 pigs were exposed individually when four weeks old to intranasal infection with 10(8.9) viable Actinobacillus pleuropneumoniae (serovar 3, strain 2/(10P2); a fourth group was kept in isolation from the others as uninfected controls. Seven days later the 62 surviving animals were killed and necropsied. The organism had caused typical, mainly subacute disease in 12 of the 16 unmedicated animals but in only two of the 16 which had had continuous access to a diet containing 150ppm of enrofloxacin from four hours before exposure to infection, and in six of the 16 given 32 ppm enrofloxacin. However, only 150 ppm enrofloxacin produced marked control of the infection in terms of reduced average severity of thoracic lesions and much reduced prevalence of the organism in the lung at necropsy, and the mean weight gain (1.55 kg) and feed conversion efficiency (2.08) of this infected group over seven days were similar to those of the unmedicated, uninfected controls (1.67 kg and 2.25). The infected but untreated group on average produced detectable antibody seven days after infection whereas in the infected and medicated groups a specific response against serovar 3 was absent.

4-Quinolones↗

Concentration-related effects of morphine on cognition and motor control in human subjects.

Morphine and other opioid analgesics may interfere with normal cognition and motor function when the drugs are used for long-term treatment of pain. We used individually tailored steady-state drug infusions to identify the nature and extent of cognitive and motor effects of the mu-receptor-selective opioid morphine in healthy volunteers. The tailored infusions allowed evaluation of cognitive and motor effects at three sequential, constant plasma concentrations of morphine in each subject. Compared with functional assessments obtained in a separate saline infusion day, infusions of morphine to plasma concentrations in the usual therapeutic range for analgesia caused significant impairments of some but not all elements of cognitive and motor function. The time needed to encode and process serially presented verbal information increased and the ability to maintain low consistent levels of force decreased during the morphine infusion. We also assessed verbal recall 3 hours after the morphine and saline infusions. Delayed recall of information presented during the morphine infusion was significantly impaired. Our results demonstrate that morphine can interfere with cognitive and motor performance at plasma drug concentrations within the usual therapeutic range.

Adult↗

Calibration of a prompt neutron activation analysis facility for the measurement of total body protein.

Prompt neutron activation analysis with 252Cf has been used to measure total body protein. Since simultaneous irradiation and detection generated a high count rate at the detectors the nucleonic system was optimised to reduce distortions in the gamma ray energy spectrum. Tissue-equivalent phantoms were used to calibrate the apparatus. A total of 53 studies was performed on 39 normal subjects. Ratios of total body protein to fat-free mass agreed well with those from other centres and with cadaver studies. Duplicate measurements of 14 subjects gave a coefficient of variation of +/- 2.9% for a measurement of total body protein, which is close to that calculated from the known errors of the technique of +/- 2.7%. The whole body dose equivalent was 0.17 mSv.

Activation Analysis↗

An introduction to body composition models used in nutritional studies.

Chemical analysis of cadavers has led to the definition of 'reference' man but diseases may result in significant changes in body composition. By measuring body composition in patient groups the nature of disease progression can be followed and management regimens evaluated. Various techniques are available which attempt to measure body composition in vivo. Several models of body composition have evolved with the introduction of new measurement techniques. A description of these models is presented. The limitations of the models and the techniques adopted for their measurement are discussed.

Body Composition↗

Severe clinical manifestations of primary HIV infection.

Three cases of oesophageal candidiasis in association with primary HIV infection are described. In each case the candidiasis was associated with a decreased number of circulating CD4+ cells and responded well to treatment with ketoconazole. Clinicians should be aware that severe opportunistic infections may develop during this stage of infection, presumably as a result of transient immunodeficiency. We argue that the definition of primary HIV infection should be extended to include severe opportunistic infections and neurologic presentations.

Adult↗

Identification of the multidrug resistance-related P-glycoprotein as a cyclosporine binding protein.

The immunosuppressive agent cyclosporine A has been shown to reverse multidrug resistance (MDR) in malignant cells. In the present study, a 3H-cyclosporine diazirine analogue was used to photolabel viable MDR Chinese hamster ovary cells. The 170-kDa membrane P-glycoprotein, which functions as a drug efflux pump, was strongly labeled. The binding of 3H-cyclosporine diazirine analogue to P-glycoprotein was competable by excess cyclosporine A and by the nonimmunosuppressive cyclosporine H. These results suggest that cyclosporine reverses the MDR phenotype by binding directly to P-glycoprotein and that this binding is not dependent on the immunosuppressive potential of the cyclosporine derivative. The identification of P-glycoprotein as a cyclosporine binding protein has obvious implications for cancer chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Actions of bovine skin washings and sera on the motile zoospores of Dermatophilus congolensis.

Concentrated skin washings, even from vaccinated animals, failed to inhibit the motility of the infective zoospores of Dermatophilus congolensis, or to prevent them from germinating or infecting cattle; their constituent immunoglobulins did not attach to the flagella although IgA and IgG2 did bind to the cell bodies. It is concluded that the specific antibodies at the skin surface of ruminants are unlikely to have a role in zoospore immobilisation. Post vaccination sera rapidly immobilised and clumped the zoospores by means of a coat around the flagella, in which immunoglobulins, particularly IgM, were detected. IgM and IgG1 also attached to the cell bodies of the zoospores.

Actinomycetales↗

Serological characterisation of a mouse monoclonal anti-P-like antibody.

An IgM mouse monoclonal antibody, LM 147/328, raised against an Escherichia coli immunogen, was found to possess anti-P-like specificity. It is proposed that this antibody recognises an epitope on a Gal beta 1-3GalNAc disaccharide structure (GalNAc = N-acetyl-D-galactosamine). The haemagglutinating activity of this antibody was consistently strong with adult erythrocytes, but gave significantly weak reactions with about 7% of cord erythrocyte samples.

Animals↗

Drawover vaporizers.

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Anesthesia, Inhalation↗