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Biomedical subjects

A Williams

Publications and source records attributed to A Williams.

At least 523 records · Page 29Linked to original sources
PubMed1987

Immunocytochemical demonstration of the association between Legionella pneumophila, its tissue-destructive protease, and pulmonary lesions in experimental legionnaires' disease.

Using immunocytochemical techniques at the light and electron microscope levels, Legionella pneumophila and one of its extracellular proteases were located in the lungs of guinea pigs with experimental Legionnaires' disease (LD). L. pneumophila was immunostained by several peroxidase- and gold-labelling methods for light and electron microscopy. The protease was immunolabelled in tissue fixed in Carnoy's fluid at the light microscopical level and on broth-grown organisms at the ultrastructural level. It was not labelled in either formalin- or glutaraldehyde-fixed tissue. Using double-labelling techniques, L. pneumophila and protease were located in the same section and were shown to be intimately associated with pulmonary lesions, providing strong evidence for the role of this protease in LD pneumonia.

Animals↗
PubMed1987

Analytical modeling of worldwide medical radiation use.

An analytical model was developed to estimate the availability and frequency of medical radiation use on a worldwide basis. This model includes medical and dental x-ray, nuclear medicine, and radiation therapy. The development of an analytical model is necessary as the first step in estimating the radiation dose to the world's population from this source. Since there is no data about the frequency of medical radiation use in more than half the countries in the world and only fragmentary data in an additional one-fourth of the world's countries, such a model can be used to predict the uses of medical radiation in these countries. The model indicates that there are approximately 400,000 medical x-ray machines worldwide and that approximately 1.2 billion diagnostic medical x-ray examinations are performed annually. Dental x-ray examinations are estimated at 315 million annually and approximately 22 million in-vivo diagnostic nuclear medicine examinations. Approximately 4 million radiation therapy procedures or courses of treatment are undertaken annually.

Africa↗
PubMed1987

Replication of cauliflower mosaic virus DNA in leaves and suspension culture protoplasts of cotton.

Cauliflower mosaic virus (CaMV) replicated in protoplasts and in inoculated leaves of the non-host, cotton (Gossypium hirsutum, L.). Protoplasts prepared from suspension-cultured cotton cells were infected by incubation with liposome-encapsulated CaMV virions. During a 1-week culture period the amount of CaMV nucleic acid as detected by nucleic acid hybridization in the protoplasts increased significantly regardless of whether or not the protoplasts contained vacuoles. In leaves inoculated with CaMV virions or CaMV DNA, viral DNA sequences were found by leaf skeleton hybridization to be located in small circular areas. DNA extracted from ultracentrifugal pellets of homogenates of inoculated leaves contained circular, gapped CaMV DNA only when inocula contained CaMV virions, CaMV DNA, or partial nested dimer CaMV plasmid DNA. When plants had been heavily watered, the CaMV DNA recovered contained degraded CaMV DNA. The results suggest that the host range limitation for CaMV is not due to an inability to replicate or spread locally in inoculated leaves.

Journal Article↗
PubMed1987

Fibronectin and immune complexes in rheumatic diseases.

The relation between fibronectin and immune complexes in rheumatic disease was examined in a series of linked studies. Fibronectin was present in immune complexes formed in vitro in the absence of C1q. Gel filtration chromatography showed complexed fibronectin was present in the serum of a patient with rheumatoid vasculitis, but not in normal serum; the complexed fibronectin coeluted with IgA and C3. Two dimensional immunoelectrophoresis showed a single fibronectin component was present in normal serum, but a number of components were present in serum from a rheumatoid patient. Polyacrylamide gel electrophoresis followed by immunoblotting for fibronectin showed that polyethylene glycol precipitates of synovial fluid contained immunoreactive components of a variety of sizes, indicating the presence of fragments of the molecule. An analysis of fibronectin in polyethylene glycol precipitates of paired serum and synovial fluid samples from 17 patients with rheumatoid arthritis and 16 with osteoarthritis showed more fibronectin was present in rheumatoid samples, especially in synovial fluid. More fibronectin was also present in synovial fluid than in serum polyethylene glycol precipitates; there was no direct relationship with C1q levels. All these results suggest that fibronectin is an integral component of immune complexes. This has potential pathogenic significance because it shows that a product of connective tissue cells may influence the functions of the immune system.

Antigen-Antibody Complex↗
PubMed1987

Hippocampal formation and related structures of the limbic lobe: anatomic-MR correlation. Part I. Surface features and coronal sections.

Correlation of magnetic resonance (MR) images with cryomicrotome sections and formalin-fixed sections of human brain documents that spin-echo MR imaging with short repetition time/short echo time pulse sequences can display the surface gyri of the inferomedial temporal lobe, including the temporal pole, the parahippocampal gyrus, the isthmus of the cingulate gyrus, the lateral and medial occipitotemporal gyri, and the inferior temporal gyrus; the associated sulci including the rhinal and collateral sulci, the occipitotemporal sulcus, and the anterior calcarine sulcus; the components and fiber tracts of the hippocampal formation including the pes hippocampi, the hippocampus, the subiculum, the dentate gyrus, the subsplenial gyri, the alveus, the fimbria, and the fornix; the fissures and sulci associated with the hippocampal formation, including the hippocampal fissure, dentatofimbrial fissure, and the choroidal fissure; the continuity between the cingulate gyrus and the parahippocampal gyrus through the isthmus of the cingulate gyrus; and the continuity between the callosal sulcus and the hippocampal fissure.

Hippocampus↗
PubMed1987

Hippocampal formation and related structures of the limbic lobe: anatomic-MR correlation. Part II. Sagittal sections.

Magnetic resonance (MR) images in the sagittal plane display the lengths of the parahippocampal gyrus, subiculum, dentate gyrus, hippocampus, fimbria, fornix, hippocampal fissure, choroidal fissure, and temporal horn, and the anatomic relationships of these structures to the surrounding brain. Correlation of these images with anatomic specimens provides criteria for identifying these structures confidently on routine clinical MR imaging.

Hippocampus↗
PubMed1987

Intravenous thyrotropin releasing hormone in amyotrophic lateral sclerosis: autonomic effects.

Heart rate, respiratory rate, systolic and diastolic blood pressure, and oral and skin temperature changes following intravenous administration of TRH occur at lower infusion rates in patients with ALS and bulbar involvement than in patients with ALS without bulbar involvement. This autonomic sensitivity to TRH infusion is characteristic of a more advanced stage of ALS with difficulties in speaking and swallowing. Patients who will be receiving neuropeptides, such as TRH, must be carefully studied to determine whether subclinical bulbar involvement is present. Such patients may require a lower initial dose or dose rate adjustment as well as continual monitoring during neuropeptide administration.

Adult↗
PubMed1987

Silicone-induced hypercalcaemia in haemodialysis patients.

Silicone spallation from the roller-pump insert in dialysis blood lines leads to the accumulation of silicone in haemodialysis patients, which in turn leads to a foreign-body reaction with granuloma formation. We have studied two patients in whom documented silicone accumulation has been associated with both granuloma formation and significant, persistent hypercalcaemia. In both patients plasma levels of immunoreactive parathyroid hormone and 1,25-dihydroxyvitamin D were low or undetectable. In one patient, hypercalcaemia responded only partially to corticosteroids, but completely to naproxen. Both patients were changed to silicone-free blood lines and their hypercalcaemia subsequently resolved. The results indicate that in some haemodialysis patients, silicone accumulation and granuloma formation may lead to hypercalcaemia that is independent of 1,25-dihydroxyvitamin D, and that may instead reflect altered prostaglandin metabolism.

Adult↗
PubMed1987

Abnormalities in the immune system of children with beta-thalassaemia major.

We have studied both the humoral and cell mediated immune systems of 23 children with beta-thalassaemia major. In children who had not been splenectomized, a 3-fold expansion in the number of circulating B cells and a modest polyclonal gammopathy was present. Of these patients 70% had decreased numbers of circulating T4 cells; 83% were unresponsive to skin testing with Candida albicans, and the majority had decreased lymphocyte proliferative responses in vitro. In children who had been splenectomized, there was a 10-fold increase in the number of circulating B lymphocytes and a 2-fold increase in the number of T4 and T8 cells present in peripheral blood. Additionally, these patients as a group were more responsive to both skin testing and lymphocyte stimulation in vitro with Candida albicans. Seven patients had an inverted T4/T8 ratio. One child has positive serology to HIV by ELISA and Western Blot techniques with a normal T4/T8 ratio. Thus, while children with thalassaemia are at risk for exposure to HIV, the immunological abnormalities associated with the disease and/or its treatment necessitates cautious interpretation of any AIDS-related immunological changes.

Acquired Immunodeficiency Syndrome↗