Search PubMed⌕ Search

Biomedical subjects

R J Hay

Publications and source records attributed to R J Hay.

At least 235 records · Page 13Linked to original sources
PubMed1983

Nocardial infection of the skin.

This paper describes the relationship between different forms of nocardia infection involving the skin. The best recognized of these conditions are systemic nocardiosis and actinomycetoma due to Nocardia spp. in which the organisms are present in either filamentous or grain form respectively. Attention is drawn to evidence for the existence of a primary cutaneous form of nocardiosis which follows inoculation and in which the organisms grow in filamentous phase. It is not clear whether such cases can progress to mycetoma formation if left untreated, or whether other factors are involved. The clinical and laboratory features of these different clinical varieties of nocardia infection are discussed.

Animals↗
PubMed1983

An ultrastructural study of pale eumycetoma grains.

The electron microscopic appearances of grains from seven patients with pale grain eumycetoma infections have been studied. The infecting fungi were Pseudallescheria boydii (2), Fusarium sp. (1), Acremonium kiliense (1), a non-sporing mould (2) and Trichophyton violaceum (1). P. boydii grown in vitro and grains from a Madurella mycetomatis infection were used for comparison. The most important ultrastructural features of the pale eumycetoma grains were the gross thickening of the fungal cell walls maximal at the periphery of the grain, the predominance of grossly disorganised hyphae and the appearance of cytoplasmic membrane systems. In some areas adjacent cell walls appeared to fuse. These changes may account for some of the well recognised difficulties in isolating organisms from eumycetoma grains and treating the infections with antifungal drugs.

Ascomycota↗
PubMed1983

Experimental dermatophytosis: the clinical and histopathologic features of a mouse model using Trichophyton quinckeanum (mouse favus).

We have established a reproducible mouse model of dermatophytosis using Trichophyton quinckeanum. There was considerable variation in the pathogenic potential among 10 different strains of T. mentagrophytes or T. quinckeanum; susceptibility to the infection varied with the inbred strain of mouse used, with BALB/c or BALB/K mice proving to be the most susceptible. The primary infection was characterized by the development of a scutulum or crust consisting of large quantities of dermatophyte mycelium, dense infiltration with neutrophils, but minimal epidermal proliferation. By contrast, a secondary infection initiated 30 days after the primary infection showed different features with early and almost total elimination of fungal elements, a predominantly mononuclear cell response, and epidermal proliferation. If the secondary infection was given at the peak of the primary illness (day 7), there was a mononuclear cell response with epidermal proliferation but fungal mycelium was prominent and not quickly eliminated. The value of this model in investigating the kinetics of the immune response to experimental dermatophytosis is discussed.

Animals↗
PubMed1983

Immune responses of patients with tinea imbricata.

Tinea imbricata is a chronic dermatophyte infection caused by Trichophyton concentricum affecting large areas of the skin surface. Spontaneous improvement is unusual and relapse after apparently successful treatment is common. In this study in Papua New Guinea it was found that a high proportion of infected patients had immediate-type hypersensitivity (52%) or negative responses (46%) to intradermal trichophytin. The majority of patients failed to develop delayed-type hypersensitivity on skin testing or as assessed in vitro by leucocyte migration inhibition. However, 78% of patients investigated had antibody to T. concentricum. The relevance of T-lymphocyte hyporeactivity to persistence of the infection is discussed.

Antibodies, Fungal↗
PubMed1983

A comparative study of dermatophytosis in coal miners and dermatological outpatients.

The causative organisms and susceptibility factors were compared in two groups of individuals with tinea pedis, coal miners (234) and dermatological outpatients (244). Trichophyton rubrum was the commonest dermatophyte in both groups, being isolated from 71% of infected miners and 77% of infected outpatients. The incidence of atopy in the outpatients, but not the miners, was significantly higher in individuals with T rubrum infections than in control groups. An analysis of the data from both groups suggests that in the coal miners, in whom there is a high risk of endemic dermatophytosis, susceptibility factors such as atopy are of less importance than in patients seen in a dermatological outpatient clinic in whom the risk of exposure to other sources of dermatophytosis is low.

Adolescent↗
PubMed1982

The histopathological features of pale grain eumycetoma.

Histological findings in 24 cases of pale grain eumycetoma have been compared. The inflammatory response and morphology of grains caused by different organisms are very similar. However the histological appearances of Neotestudina rosatii infections, although reminiscent of dermatophyte mycetomas, are distinctive. The characteristic features include the presence of cement and the short swollen hyphal segments. Petriellidium boydii grains are more likely to contain numerous vesicles or swollen hyphae and be surrounded by a prominent eosinophilic fringe. In contrast, Fusarium and Acremonium grains usually have a minimal fringe and contain a dense mass of intermeshing hyphae. However the features separating P. boydii and Fusarium/Acremonium grains are not invariable and can only be used as an approximate guide to the correct identity of the organism.

Eosinophils↗
PubMed1982

Karyotype consistency in human colorectal carcinoma cell lines established in vitro.

Karyotypes of nine human colorectal cell lines deposited with the ATCC were studied by trypsin-Giemsa banding. CCL 229,230,231 and 235 (Modal chromosome number, Sm, was 49, 68, 47, and 40, respectively) belong in the stable type that is characterized by karyotypes consisting mostly of normal chromosomes and stable markers. CCL 228, 234, and 238 (Sm=55,79, and 70 respectively) belong in the unstable type that has karyotypes consisting of numerous markers in addition to normal chromosomes and stable markers. The remaining intermediate type (CCL 233 and 237, Sm = 60 and 64, respectively) has karyotypic characteristics between the above two types usually with two or less unstable markers per cell. The stable markers (together with normal chromosomes) are constitutive components of a cell genome and are common to most cells within the same cultured population. Unstable markers, which generally constitute only a small portion of the total chromosome complement are the likely cause of karyotypic variations between cells and often are produced by balanced inter- or intrachromosome changes, or both. Consequently, total chromosome length per cell genome is remarkably consistent within a cell population, and karyotypes between cells, such as from four stable lines, are profoundly stable and mostly identical. Chromosome deletions and interhomologue exchanges (including isochromosomes) had the highest incidences among both stable and unstable markers. The complex markers occurred relatively infrequently. There were neither common markers nor unique chromosome breakages common to all of these established cell lines. However, chromosomes No. 7 and 1 had the highest incidence (15 and 12, respectively) of structural modifications resulting in the formation of stable markers (82 total exchanges in nine cell lines), and chromosomes No. 7 and 2 were involved at high incidence (21 and 15, respectively) in the formation of both stable and unstable markers (181 total exchanges). Moreover, No. 7 is overrepresented in eight of nine lines. The significance of chromosome changes involving No. 7 in this as well as other tumor pathotypes is briefly discussed.

Carcinoma↗
PubMed1982

Chronic dermatophyte infections. I. Clinical and mycological features.

One hundred and six patients with chronic dermatophytosis unresponsive to griseofulvin were studied. Trichophyton rubrum was the causative organism in 93% of cases. Chronic dermatophyte infections caused by organisms other than T. rubrum occurred predominantly, but not exclusively, in patients with underlying diseases. Forty-nine percent of the patients had a personal or family history of atopy but other abnormalities included disorders of keratinization, collagen vascular disease and systemic steroid therapy. The commonest sites of infection were the palms and soles, as opposed to toe webs or groins in control patients with griseofulvin-responsive dermatophyte infections. A significant proportion of chronically infected patients had raised IgE levels. Only 11% of the chronically infected group showed delayed hypersensitivity responses to intradermal trichophytin but 58% showed immediate hypersensitivity responses to trichophytin as well as other fungal and non-fungal allergens.

Adolescent↗
PubMed1982

Chronic dermatophyte infections II. Antibody and cell-mediated immune responses.

In patients infected with Trichophyton rubrum, the T lymphocyte responses (lymphocyte transformation) to trichophytin were reduced, compared with control subjects. The same levels were seen in patients with intractable chronic infection and those who responded well to treatment but the site of infection affected the immune response, lower levels being seen in patients with palmo-plantar infection than in those with groin infections. In infections coursed by T. mentagrophytes by contrast, lymphocyte responses to specific antigens were significantly increased.

Antibody Formation↗
PubMed1982

Cultured cell lines for research on pulmonary physiology available through the American type culture collection.

Procedures are described by which cell lines of potential use for studies on pulmonary physiology were developed or otherwise obtained, characterized, and banked for distribution to the scientific community. Seventy-seven cell lines were submitted under this program. Forty-eight of these exhibited adequate doubling potential and were of sufficient interest and purity to permit accessioning and banking for distribution. An additional 12 lung cell lines had been added earlier during development of the Cell Repository. In all, 4 presumptive type II alveolar lines, 2 nonspecified epithelial-like lines, 2 endothelial lies, 1 mesothelial line, and 51 fibroblastlike lines are available. Eighteen species including humans, monkeys, and common laboratory animals are represented. An additional 19 lines were retained as token holdings because they either exhibited insufficient doubling potential or represented duplicate samples of differing passage levels. Ten lines were rejected because of poor viability, presence of contaminant microorganisms, or inappropriate species identification by the donor. The lines will be retained at the ATCC for distribution on request to the scientific community at large. As newly developed strains are identified and made available these may also be added to the existing collection. Appropriate cooperation from the scientific community and support from governmental funding agencies are required and acknowledge.

Adolescent↗
PubMed1982

Plasmodium falciparum malaria. An amelanotic melanoma cell line bears receptors for the knob ligand on infected erythrocytes.

Erythrocytes infected with Plasmodium falciparum trophozoites and schizonts are not seen in the peripheral circulation because they attach to venular endothelium via knoblike structures on the infected erythrocyte membrane. We have recently shown that erythrocytes containing P. falciparum trophozoites and schizonts likewise attach to cultured human venous endothelial cells via knobs. In search of a more practical target cell for large scale binding studies designed to characterize and isolate the knob ligand, we tested various normal cells and continuous cell lines for their ability to bind P. falciparum-infected erythrocytes. Of the 18 cell types tested, binding of infected erythrocytes was observed to a human amelanotic melanoma cell line and amnion epithelial cells as well as to human aortic and umbilical vein endothelial cells. 96-100% of amelanotic melanoma cells bound 17+/-4 (+/-1 SEM) infected erythrocytes per positive cell, whereas fewer endothelial cells (4-59%) and amnion epithelial cells (8-19%) were capable of binding 12+/-5 and 4+/-1 infected erythrocytes per positive cell, respectively. Further studies designed to compare the mechanism of binding to the amelanotic melanoma cell line and endothelial cells showed the following results. First, that adhesion of infected erythrocytes to these two cell types was parasite stage-specific in that only erythrocytes containing late ring forms, trophozoites, and schizonts bound. Erythrocytes containing early ring forms, which do not attach to venular endothelium in vivo, did not bind to either cell type. Second, erythrocytes infected with trophozoites and schizonts of P. vivax or a knobless strain of P. falciparum, both of which continue to circulate in vivo, did not bind to either target cell type. Third, transmission electron microscopy showed that infected erythrocytes attached to the amelanotic melanoma cells via knobs. We conclude that cultured human endothelial cells and an amelanotic melanoma cell line share common determinants on their surface and that the mechanism of binding to these two different cell types is similar. The amelanotic melanoma cell line offers a useful substitute for endothelial cells in binding studies requiring large numbers of target cells.

Amnion↗