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Biomedical subjects

C Love

Publications and source records attributed to C Love.

At least 55 records · Page 3Linked to original sources
PubMed1990

Detection of rubella antibody using an optical immunosensor.

Since the first biosensor was reported in 1962 different sensors have been developed in different areas; their attraction being that they hold out the possibility of a rapid test which can specifically detect the analyte, without the necessity for additional reagents. Immunosensors make use of antibodies and can be extremely specific if the appropriate monoclonal antibodies are used. We report on the development of an optical immunosensor used for the detection of rubella antibody in serum, plasma and whole blood. The assay time is less than 10 min and requires no accurate measurement of the sample or any additional reagents. The sensitivity is in the region of 30 IU/ml; with a correlation of 94% with conventional assays.

Antibodies, Monoclonal↗
PubMed1989

Neurological features of HIV-related disease in Glasgow.

The neurological features of 10 patients with HIV-related disease seen in Glasgow between July 1984 and May 1988 are described. Two of these patients presented with ARC and eight with AIDS. Six patients showed features consistent with a diagnosis of AIDS-dementia complex, one had cerebral toxoplasmosis, one had CNS lymphoma, one had a probable drug-induced encephalopathy and one patient had a meningoencephalitis of undetermined cause. Seven of these patients have now died. The implications of these findings are discussed.

AIDS-Related Complex↗
PubMed1987

Mutations affecting expression of the rosy locus in Drosophila melanogaster.

The rosy locus in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Previous studies defined a "control element" near the 5' end of the gene, where variant sites affected the amount of rosy mRNA and protein produced. We have determined the DNA sequence of this region from both genomic and cDNA clones, and from the ry+10 underproducer strain. This variant strain had many sequence differences, so that the site of the regulatory change could not be fixed. A mutagenesis was also undertaken to isolate new regulatory mutations. We induced 376 new mutations with 1-ethyl-1-nitrosourea (ENU) and screened them to isolate those that reduced the amount of XDH protein produced, but did not change the properties of the enzyme. Genetic mapping was used to find mutations located near the 5' end of the gene. DNA from each of seven mutants was cloned and sequenced through the 5' region. Mutant base changes were identified in all seven; they appear to affect splicing and translation of the rosy mRNA. In a related study (T. P. Keith et al. 1987), the genomic and cDNA sequences are extended through the 3' end of the gene; the combined sequences define the processing pattern of the rosy transcript and predict the amino acid sequence of XDH.

Animals↗
PubMed1986

On the identification of the rosy locus DNA in Drosophila melanogaster: intragenic recombination mapping of mutations associated with insertions and deletions.

DNA extracts of several rosy-mutation-bearing strains were associated with large insertions and deletions in a defined region of the molecular map believed to include the rosy locus DNA. Large-scale, intragenic mapping experiments were carried out that localized these mutations within the boundaries of the previously defined rosy locus structural element. Molecular characterization of the wild-type recombinants provides conclusive evidence that the rosy locus DNA is localized to the DNA segment marked by these lesions. One of the mutations, ry2101, arose from a P-M hybrid dysgenesis experiment and is associated with a copia insertion. Experiments are described which suggest that copia mobilizes in response to P-M hybrid dysgenesis. Relevance of the data to recombination in higher organisms is considered.

Animals↗
PubMed1986

The underlying bases of gene expression differences in stable transformants of the rosy locus in Drosophila melanogaster.

This report represents a continuation of our laboratory's effort to understand the major phenomena associated with P-M dysgenesis-mediated transformation in Drosophila. A group of stable transformants are characterized with respect to rosy gene expression. Stable, true-breeding, line-specific variants in gene expression are described. These are shown to be associated with single transposons present in each line, and the lines are free of functional P elements. The effects on expression are cis-acting, and there are no identifiable rosy DNA sequence lesions associated with these transposons. Evidence is presented that demonstrates that two features of the transformation experimental system are responsible for such variation. The first relates to the fact that the transposons insert at numerous genomic sites. Both heterochromatic and euchromatic position effects are characterized. The second relates to the fact that transformation involves dysgenic mobilization of a P-element transposon. This process is mutagenic, and such a mutation is characterized.

Animals↗
PubMed1985

Dysgenesis-induced instability of rosy locus transformation in Drosophila melanogaster: analysis of excision events and the selective recovery of control element deletions.

Utilizing the method of P-M hybrid dysgenesis-mediated gene transfer to insert rosy locus DNA into various chromosomal locations, we recovered a transformed strain that carries an ry+ transposon inserted in or near the scalloped locus in polytene section 13F on the X chromosome. The resultant product, when stabilized, behaves as a homozygous and hemizygous viable and fertile extreme scalloped allele associated with wild-type expression of the rosy locus. We have labeled this allele, sdry+. This allele has been destabilized by subsequent P-M hybrid dysgenesis, and mutations were recovered that exhibit alterations in the rosy and/or scalloped phenotypes. Representative samples of all phenotypic classes have been characterized by Southern blot analyses of restricted DNA. The most common events are excisions of DNA wholly internal to the transposon and representing sections of rosy DNA. In addition to loss of rosy locus function, such excisions affect the scalloped locus expression.--A second dysgenesis experiment was carried out involving an ry+ transposon inserted in polytene section 16D on the X chromosome. A minimal estimate of the relative frequency of imprecise excisions, determined in this experiment is 75%.--A successful pilot experiment is described that utilizes dysgenic perturbation of the sdry+ allele to select for small deletions of the 5' noncoding region of the rosy locus.

Animals↗
PubMed1978

Drug interference in clinical chemistry: studies on ascorbic acid.

The expert group "Drug Interference in Clinical Chemistry" of the Bureau of Reference, Directorate General for Research, Science and Education of the Commission of the European Communities, consisting of one participant of each member of the European Communities, presents this first report on the final results of its activities. Within the framework of a first stage basic program, the paper describes interferences of therapeutic and elevated doses of ascorbic acid on commonly used clinical chemical methods. This is the result of a bipartite study that was jointly planned, carried out and evaluated. Local and personal influences have been eliminated, as have variations due to methodology, measurement equipment and reagents, in order to be able to present distinct causal effects of ascorbic acid. No definite influence of ascorbic acid on analytical values for urea, cholesterol, calcium, protein, bilirubin, aspartate aminotransferase and alkaline phosphatase could be detected. At therapeutic concentrations, ascorbic acid distinctly interferes with the analysis of glucose, uric acid, creatinine and inorganic phosphate. The extent and direction of interferences vary, depending on the type of reaction, kit and apparatus. In some cases the influence of ascorbic acid results in severe disturbance of the analytical methods leading to useless values.

Ascorbic Acid↗
PubMedDate not supplied

The relationship between legal factors and attrition from a residential drug abuse treatment program.

This article examines the legal involvement of 438 clients randomized to three- and six-month versions of a residential drug abuse treatment program with respect to early attrition (before 40 days in treatment) and later attrition (40-79 days in treatment). Concern about legal problems was reported by 21% of subjects in response to an open-ended question about factors that led to admission; 42% had other legal circumstances that were determined either from documented evidence of legal involvement from chart review or from self-report through structured questioning about legal status. For those with "concern about legal problems" the early attrition rate was 16%, compared with 33% for those with no legal factors--odds ratio (OR) .38 with 95% confidence interval (95% CI) (.20,.73) and the later attrition rate was 25%, OR .76, 95% CI (.39,1.48). Those subjects with "legal circumstances" only had an early attrition rate of 29%--OR .86, 95% CI (.54,1.37) and a later attrition rate of 19%, OR .53, 95% CI (.29,.98) compared to those with no legal factors. There was little evidence of confounding in any of these results from adjusted analyses. Findings suggest that only self-reported concern about legal status as a problem mentioned at entry to treatment is significantly associated with lower early attrition and there is no significant relationship of legal factors with later attrition.

Adult↗
PubMedDate not supplied

Rapid intraoperative construction of autologous small caliber blood vessels.

Autologous pericardium, briefly tanned in glutaraldehyde, is an excellent biomaterial when used in various cardiac procedures, including repair and replacement of heart valves. A generalized lack of calcification and an absence of inflammatory response in these combined experiences has led the authors to consider the use of treated autologous pericardium for the construction of substitute small caliber blood vessels. Rapid, intraoperative construction of a vascular graft from autologous pericardium, briefly treated in 0.62% glutaraldehyde, is accomplished through the use of two concentric, mating helical stents that support a rectangular pattern of tissue into a cylindrical, nonkinking, compliant conduit. A disposable automated assembly tool provides for precise assembly of the tissue and stents. The tools and methods for construction of vascular grafts from nonvascular tissue are known as the Rapidgraft (Ramus Medical Technologies, Santa Barbara, CA). The technique can be used with any suitable tissue. Accelerated fatigue test studies have confirmed that stent supported pericardial grafts are capable of withstanding physiologic pressures and flows beyond 7 equivalent years. Six autologous pericardial grafts measuring 5 mm in diameter by 5.5 cm in length showed 100% patency beyond 5 months in a growing calf carotid artery model. Pathological examination of explanted grafts confirm the presence of a continuous endothelial lined surface, infiltration of the tissue by fibrous connective tissue such that the individual layers of the pericardial vessel wall could not be identified, and there was no inflammatory response. Based on the encouraging results in animal studies, a small multicenter clinical trial has been initiated to evaluate the performance of the Rapidgraft as a replacement conduit for the radial artery in cases in which the radial artery has been harvested as a coronary artery bypass conduit. Results from the radial artery trial will be used as an indication to evaluate the Rapidgraft as a coronary artery substitute. We conclude that the material properties, including the biological origin of a vessel wall, may be significant determinants of graft patency, and that the Rapidgraft may be an answer to the need for small caliber arterial graft with the potential for long-term patency and durability.

Blood Vessel Prosthesis↗
PubMedDate not supplied

Role of radionuclide imaging in the diagnosis of postoperative infection.

Postoperative infections are a serious cause of morbidity and mortality and are difficult to diagnose. Signs and symptoms that are generally associated with infection may be masked by, or mistaken for, normal postoperative changes. Anatomic imaging modalities provide high-quality anatomic detail and are the procedures of choice in affected patients because of their availability, ease of performance, accuracy, and value in the selection of treatment options. However, radionuclide studies demonstrate physiologic processes, which often precede anatomic changes, and can help distinguish normal postoperative inflammation from infection. Radionuclide studies are also useful in identifying complicated orthopedic infections, in which the often extensive distortions produced by metallic hardware can confound the interpretation of anatomic images. Of the three agents (gallium-67 citrate, indium-111-labeled leukocytes, technetium-99m-labeled leukocytes) that are currently approved in the United States for imaging of infection, In-111-labeled leukocyte imaging is the procedure of choice for diagnosing postoperative infection. Gallium scintigraphy is best reserved for those situations in which leukocyte imaging is not available or there is concern that the suspected infection may not incite a neutrophil response. In general, the value of radionuclide imaging is maximized when used only in those patients for whom the results of anatomic imaging are negative, nondiagnostic, or at odds with the clinical impression.

Abdominal Abscess↗
PubMedDate not supplied

Role of nuclear medicine in diagnosis of the infected joint replacement.

Some complications of joint replacement surgery are easily diagnosed; however, differentiating infection from aseptic loosening is difficult because these entities are remarkably similar at clinical and histopathologic examination. Clinical signs and symptoms, laboratory tests, radiography, and joint aspiration are insensitive, nonspecific, or both. Cross-sectional imaging modalities are hampered by artifacts produced by the prosthetic devices themselves. Radionuclide imaging is not affected by the presence of metallic hardware and is therefore useful for evaluating the painful prosthesis. Bone scintigraphy is useful as a screening test, despite an accuracy of only 50%-70%, because normal results essentially exclude a prosthetic complication. The addition of gallium-67, a nonspecific inflammation-imaging agent, improves the accuracy of bone scintigraphy to 70%-80%. The accuracy of combined leukocyte-marrow imaging, 90%, is the highest among available radionuclide studies. Its success is due to the fact that leukocyte imaging is most sensitive for detection of neutrophil-mediated inflammation (ie, infection). The success of leukocyte-marrow imaging is tempered by the limitations of in vitro labeling. In vivo labeling has been investigated, and a murine monoclonal antigranulocyte antibody appears promising. Some investigations have focused on fluorodeoxyglucose imaging. Although this method is sensitive, specificity is a concern.

Bone and Bones↗