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Biomedical subjects

G Wild

Publications and source records attributed to G Wild.

At least 19 recordsLinked to original sources
PubMed1991

Traffic through the Golgi apparatus as studied by radioautography.

The ability to radiolabel biological molecules, in conjunction with radioautographic or cell fractionation techniques, has brought about a revolution in our knowledge of dynamic cellular processes. This has been particularly true since the 1940's, when isotopes such as 35S and 14C became available, since these isotopes could be incorporated into a great variety of biologically important compounds. The first dynamic evidence for Golgi apparatus involvement in biosynthesis came from light microscope radioautographic studies by Jennings and Florey in the 1950's, in which label was localized to the supranuclear Golgi region of goblet cells soon after injection of 35S-sulfate. When the low energy isotope tritium became available, and when radioautography could be extended to the electron microscope level, a great improvement in spatial resolution was achieved. Studies using 3H-amino acids revealed that proteins were synthesized in the rough endoplasmic reticulum, migrated to the Golgi apparatus, and thence to secretion granules, lysosomes, or the plasma membrane. The work of Neutra and Leblond in the 1960's using 3H-glucose provided dramatic evidence that the Golgi apparatus was involved in glycosylation. Work with 3H-mannose (a core sugar in N-linked side chains), showed that this sugar was incorporated into glycoproteins in the rough endoplasmic reticulum, providing the first radioautographic evidence that glycosylation of proteins did not occur solely in the Golgi apparatus. Studies with the tritiated precursors of fucose, galactose, and sialic acid, on the other hand, showed that these terminal sugars are mainly added in the Golgi apparatus. With its limited spatial resolution, radioautography cannot discriminate between label in adjacent Golgi saccules. Nonetheless, in some cell types, radioautographic evidence (along with cytochemical and cell fractionation data) has indicated that the Golgi is subcompartmentalized in terms of glycosylation, with galactose and sialic acid being added to glycoproteins only within the trans-Golgi compartment. In the last ten years, radioautographic tracing of radioiodinated plasma membrane molecules has indicated a substantial recycling of such molecules to the Golgi apparatus.

Animals↗
PubMed1991

Inter-relationships between platelet count, platelet IgG, serum IgG, immune complexes and severity of liver disease.

Thrombocytopenia is a common finding in subjects with chronic liver diseases. A variety of mechanisms may underlie this. Immunological disturbances are commonly a feature in chronic liver disease, including hyperglobulinaemia and the presence of autoantibodies and circulating immune complexes and immune mechanisms could therefore contribute to thrombocytopenia. We have investigated the relationships between blood platelet count, serum IgG and IgG immune complexes and IgG associated with platelets in 92 subjects with chronic liver disease (27 with chronic active hepatitis, 38 with primary biliary cirrhosis and 27 with alcoholic liver disease). Severity of liver impairment was a major determinant of degree of thrombocytopenia. Also, an inverse relationship was demonstrated between platelet count and platelet-associated IgG. In subjects with chronic active hepatitis the relationships between platelet count, serum IgG immune complexes and platelet-associated IgG were consistent with a role for immune mechanisms in general and immune complexes in particular as mediators of the thrombocytopenia.

Antigen-Antibody Complex↗
PubMed1990

Problems of mediator measurement for a national advisory service to U.K. anaesthetists.

Large numbers of life threatening anaphylactoid reactions are encountered following administration of general anaesthesia. Advice on the future management of the survivors is essential and requires investigation of the reaction mechanism. Demonstration of histamine release is important but unlikely to be achieved in life threatening situations. A national advisory service to anaesthetists assesses IgE-mediated histamine release in terms of the presence and utilization of specific antibodies, and non-specific histamine release in terms of urinary methylhistamine excretion.

Anaphylaxis↗
PubMed1990

IGF-I, a marker of undernutrition in hemodialysis patients.

Early detection and treatment of malnutrition in patients on hemodialysis (HD) is hampered by lack of a sensitive biochemical marker. We compared the value of serum insulin-like growth factor-I (IGF-I) with other biochemical indices in detecting malnutrition in 61 HD patients. Protein and energy intakes were low in the majority of patients. Of all patients, 59.6% had severe reduction in triceps skinfold thickness (TSF thickness, less than or equal to 60% of normal), whereas midarm muscle circumference (MAMC) was mildly reduced (less than or equal to 90%) in 23%. Serum IGF-I proved superior to the other indices in predicting TSF thickness. A serum IGF-I concentration of 300 micrograms/L discriminated between wasted (TSF thickness less than or equal to 60%) and robust patients. In 16 patients with a history of recent infection, IGF-I was significantly reduced well before changes in anthropometric measurements could be detected. IGF-I is a useful and early marker of undernutrition in HD patients.

Adolescent↗
PubMed1990

C4a anaphylatoxin levels as an indicator of disease activity in systemic lupus erythematosus.

The use of a synthetic protease inhibitor, nafamstat mesilate, has enabled reliable estimations of in vivo complement activation to be made in systemic lupus erythematosus (SLE). Elevation of C3a anaphylatoxins was found in two out of 24 patients and elevation of C4a anaphylatoxins was found in 20 out of 24 patients, confirming that complement activation, predominantly by the classical pathway, is a common occurrence in the disease. Significantly higher levels of C4a anaphylatoxin were found in 16 patients, with more aggressive disease requiring supplementary treatment with azathioprine, while the remaining eight patients, with less severe disease, required purely steroid therapy. Very strong associations between elevated C4a anaphylatoxins and raised DNA antibody titres, C1q binding activity and low complement C4 levels were also observed, suggesting that anaphylatoxin measurement may be a sensitive additional method for monitoring disease activity in SLE.

Adult↗
PubMed1990

Complement activation in systemic sclerosis.

The use of a synthetic protease inhibitor, nafamstat mesilate, has enabled reliable estimations of in vivo complement activation to be made in patients with systemic sclerosis. Elevations of C3a and C4a anaphylatoxins were found in 2 and 24 out of 30 patients respectively, indicating that complement activation, predominantly by the classical pathway, is a common occurrence in the disease, even though complement C3 and C4 levels were within the reference range.

Adult↗
PubMed1989

Carbohydrate deficient transferrin: a marker for alcohol abuse.

OBJECTIVE: To assess the value of serum carbohydrate deficient transferrin as detected by isoelectric focusing on agarose as an indicator of alcohol abuse. DESIGN: Coded analysis of serum samples taken from patients with carefully defined alcohol intake both with and without liver disease. Comparison of carbohydrate deficient transferrin with standard laboratory tests for alcohol abuse. SETTING: A teaching hospital unit with an interest in general medicine and liver disease. PATIENTS: 22 "Self confessed" alcoholics admitting to a daily alcohol intake of at least 80 g for a minimum of three weeks; 15 of the 22 self confessed alcoholics admitted to hospital for alcohol withdrawal; 68 patients with alcoholic liver disease confirmed by biopsy attending outpatient clinics and claiming to be drinking less than 50 g alcohol daily; 47 patients with non-alcoholic liver disorders confirmed by biopsy; and 38 patients with disorders other than of the liver and no evidence of excessive alcohol consumption. INTERVENTION: Serial studies performed on the 15 patients undergoing alcohol withdrawal in hospital. MAIN OUTCOME measure--Determination of relative value of techniques for detecting alcohol abuse. RESULTS: Carbohydrate deficient transferrin was detected in 19 of the 22 (86%) self confessed alcohol abusers, none of the 47 patients with non-alcoholic liver disease, and one of the 38 (3%) controls. Withdrawal of alcohol led to the disappearance of carbohydrate deficient transferrin at a variable rate, though in some subjects it remained detectable for up to 15 days. Carbohydrate deficient transferrin was considerably superior to the currently available conventional markers for alcohol abuse. CONCLUSION: As the technique is fairly simple, sensitive, and inexpensive we suggest that it may be valuable in detecting alcohol abuse.

Alcoholism↗
PubMed1989

Human T-cell mediated response to homologous lens antigen.

T-Cell response to a suspension of homologous whole lens antigen was investigated in three groups: (1) adults with normal eyes; (2) patients with mature and hypermature cataract with an intact lens capsule; and (3) patients, who had had extracapsular cataract surgery or lens injury, some of whom had clinical evidence of severe lens-induced inflammation. The results show that sensitized T-cells occur only in some patients in the third group. To our knowledge, this is the first direct evidence of a difference in the response to T-cells to lens antigen released from mature and hypermature lenses, and to lens antigen exposed by lens injury or extracapsular cataract surgery. The test may be useful to confirm clinical suspicion of delayed hypersensitivity to lens antigen in patients with severe sterile purulent inflammation or milder delayed sterile non-purulent inflammation following lens injury or extracapsular surgery, in the absence of histological proof.

Adult↗
PubMed1988

Scalloped valvulae conniventes: an endoscopic marker of celiac sprue.

The finding, in a patient with celiac sprue, of a characteristic change at endoscopy (scalloping of the valvulae conniventes, event on close inspection, but forming only a mosaic pattern from a distance) led to an endoscopic survey designed to define its incidence. In a series of 28 sequential patients found to have microscopic changes characteristic of sprue on biopsy, distinctive endoscopic changes were found in 22 (in 6 of 9 with sprue in relapse, and 16 of 19 presenting with initial symptoms). The finding of the distinctive appearance provides an endoscopically recognizable pattern that can be associated with sprue. It also provides the potential for early recognition of the process in patients in whom the diagnosis might otherwise have been delayed due to a lack of substantial evolution of the usually associated symptom complex.

Biopsy↗
PubMed1988

Immunological abnormalities 17 years after accidental exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Eighteen workers were reviewed 17 years after accidental exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin). Clinical assessment showed that they were in good health. A study of several biochemical and immunological parameters in these subjects and in 15 carefully matched controls showed no difference in serum concentrations of hepatic enzymes between exposed workers and controls. Although mean serum concentrations of cholesterol and triglyceride were higher in exposed subjects than in controls, the results did not reach statistical significance. Antinuclear antibodies and immune complexes were detected significantly more frequently in the peripheral blood of workers exposed to dioxin. There was no significant difference between exposed workers and controls in the number of T lymphocytes, B lymphocytes, and helper and suppressor T cell counts in peripheral blood, but the number of natural killer cells identified by the monoclonal antibody Leu-7 was significantly higher in workers exposed to dioxin.

Accidents, Occupational↗
PubMed1987

Polymorphic keratins in human epidermis.

Human epidermal keratins from many different individuals were identified and compared by both high-resolution 1- and 2-dimensional gel electrophoresis and immunoblotting. While the polypeptide patterns obtained for keratin-enriched cytoskeletal preparations could be considered typical of normal interfollicular epidermis, they also disclosed variations, among the individuals, concerning some of the constituent protein subunits. Three sets of interindividually varying keratins could be distinguished owing to their distinct, though small, differences in electrophoretic mobility on sodium dodecyl sulfate-polyacrylamide gels and their similar or identical charge characteristics upon nonequilibrium pH gradient electrophoresis: the basic keratins 1a and 1b as well as 5a and 5b and the acidic keratins 10a and 10b. Of each set either a doublet, showing a marked 1:1 ratio of polypeptides, or the one or the other variant protein was detected together with keratin 14, which did not display any variation in a series of 148 individual tissue samples tested. Thus, the keratin composition of human epidermis could be summarized in the formula: (1a v 1b) + (5a v 5b) + (10a v 10b) + 14. The systematic appearance of the variants suggested that each protein within a set is the product of an independent allele. In support of this hypothesis we have found that the same variant is expressed in other epithelia of a given individual. Moreover, the frequency of any of the keratins in our sampling concurred with the frequency predicted by the Hardy-Weinberg relation for the distribution of alleles in a population, as did the frequency distribution of particular keratin patterns.

Alleles↗