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Biomedical subjects

F M Tatnall

Publications and source records attributed to F M Tatnall.

18 recordsLinked to original sources
PubMed1991

Assay of antiseptic agents in cell culture: conditions affecting cytotoxicity.

In-vivo studies suggest that chlorine-releasing antiseptic agents inhibit wound healing. Studies which have used cell culture systems to evaluate cytotoxicity have generated conflicting results for the toxicity of free-chlorine agents relative to other antiseptics. Here we examine the following three factors which may influence the toxicity of individual agents within a cell culture assay: (1) cell number; (2) duration of exposure; and (3) the nature of the antiseptic diluent. Three agents (sodium hypochlorite, chlorhexidine and hydrogen peroxide) were tested on transformed human keratinocytes (SVK 14 cells). It was found that increasing cell number, and using serum or medium as a diluent, reduced the toxicity of all agents but had the greatest effect on sodium hypochlorite. In contrast, increasing the duration of exposure increased the toxicity of all agents but had the greatest effect on hydrogen peroxide. These observations may explain the high toxicity of hydrogen peroxide and relatively low toxicity of sodium hypochlorite which have been observed in vitro and are the reverse of in-vivo findings. Culture systems in which high cell numbers are coupled with an agent diluted in serum or medium, and a long exposure time, seem likely to decrease the toxicity of chlorine-releasing agents relative to hydrogen peroxide.

Cell Count↗
PubMed1990

Facial leiomyomas.

We present a patient with multiple leiomyomas confined to the left cheek, giving rise to an unusual clinical presentation of this condition. The lesions were cosmetically disfiguring and, because of their exposed location, were particularly painful in the winter months. The treatment of this condition is discussed.

Adult↗
PubMed1990

Comparative study of antiseptic toxicity on basal keratinocytes, transformed human keratinocytes and fibroblasts.

The cytotoxic effects of a range of antiseptic agents were examined on cultured human fibroblasts and basal keratinocytes and compared to those on a transformed keratinocyte line (SVK 14 cells). Cells were exposed to chlorhexidine, hydrogen peroxide and sodium hypochlorite for 15 min and cell viability was assessed 24 h later with a colorimetric assay which utilizes the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). At concentrations recommended for wound cleansing all agents produced 100% killing of all cell types. The results show that fibroblasts and keratinocytes, cells which are fundamental to the wound healing process are equally sensitive to the effects of the antiseptic agents tested, and are highly susceptible to the effects of free-chlorine containing agents. These observations are of particular importance to the use of cultured keratinocytes (culture grafts) to enhance wound healing; the application of antiseptics to such wounds is contraindicated. All three cell types tested showed similar susceptibilities to the agents tested. These findings suggest that the transformed cell line, which has the advantage of immortality and ready availability, can replace fibroblasts and keratinocytes in studies designed to investigate the adverse effects of antiseptic agents in vitro. Comparison of the ED50 concentration for each agent on all cell types to the standard use concentration produced a ranking order of toxicity which showed chlorhexidine to be the least toxic agent and sodium hypochlorite the most.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Line, Transformed↗
PubMed1989

Identification of the epidermolysis bullosa acquisita antigen by LH 7.2 monoclonal antibody: use in diagnosis.

The sera from two patients with epidermolysis bullosa acquisita were blotted against dermal extracts in comparison with the mouse monoclonal antibody LH 7.2. This antibody reacts with carboxy terminal region of type VII collagen. The epidermolysis bullosa acquisita antisera showed binding to the same molecular weight protein as LH 7.2 confirming that the target antigen for epidermolysis bullosa acquisita antibodies is the carboxy terminal region of type VII collagen. This newly described collagen forms the major component of anchoring fibrils. These findings are consistent with established ultrastructural data which have shown that the epidermolysis bullosa acquisita antigen is located within and below the lamina densa. The monoclonal antibody LH 7.2 provides an internal standard for epidermolysis bullosa acquisita autoantisera activity. The use of immunoblotting of epidermolysis bullosa autoantisera in comparison with the monoclonal antibody LH 7.2 provides definitive investigation for the diagnosis of this disorder.

Adult↗
PubMed1986

Giant solitary trichoepitheliomas located in the perianal area: a report of three cases.

Very large solitary trichoepitheliomas which arose in the perianal region in three patients are described. Although these tumours showed a striking histological similarity to classical multiple or solitary trichoepitheliomas of the face, they differed in their massive size, unusual location and by their involvement of deeper tissue. We suggest that giant solitary trichoepitheliomas is a distinct variant of trichoepithelioma that may have a predilection for the perianal region. At this site this rare tumour must be distinguished from basal cell carcinoma of the perineum and from malignant basaloid (cloacogenic) carcinoma of the anal canal.

Aged↗
PubMed1985

Non-Hodgkin's lymphoma of the skin associated with chronic limb lymphoedema.

Cutaneous non-Hodgkin's lymphoma developed within a leg affected by chronic lymphoedema. The lymphoedema had followed radiotherapy to bony metastases from a carcinoma of the prostate. Eighteen months after the development of the cutaneous tumours, extracutaneous involvement by the lymphoma became apparent. This is the second report of a non-Hodgkin's lymphoma appearing within a lymphoedematous limb. The possible reasons for such an unusual localization are discussed. Our case report illustrates that cutaneous tumours other than lymphangiosarcomas may localize to a lymphoedematous limb and clinically simulate the Stewart-Treves syndrome.

Aged↗