Biomedical subjects

D M McKenna

Publications and source records attributed to D M McKenna.

6 recordsLinked to original sources

PubMed1997

A novel quantitative immunoassay system for p53 using antibodies selected for optimum designation of p53 status.

AIM: To develop a highly sensitive and specific enzyme linked immunosorbent assay (ELISA) system for analysis of p53 protein in cancer lysates. METHODS: The anti-p53 monoclonal antibodies DO7, 1801, BP53.12, and 421, and anti-p53 polyclonal antiserum CM1 were assessed by immunohistochemistry and western blot analysis to identify those most suitable for determining p53 status of cancer cells. Antibodies with desired characteristics were used to develop a non-competitive sandwich type ELISA system for analysis of p53 expression in cancer cytosols. Using the ELISA, p53 protein concentrations were measured in a small series of breast cancers, and the quantitative values compared with p53 immunohistochemical data of the same cancers. RESULTS: DO7 and 1801 gave the most specific and reliable results on immunohistochemistry and western blot analysis. Using these two antibodies, a non-competitive sandwich type ELISA system was developed to analyse p53 quantitatively. Analysis of the breast cancer series showed a good correlation between immunohistochemistry and the ELISA-tumours were generally positive using both techniques. Discrepancies were noted however: some cancers were immunohistochemically negative but ELISA positive. One explanation for this may be that the ELISA is more sensitive than immunohistochemistry. CONCLUSION: The p53 ELISA system is a non-competitive double monoclonal antibody sandwich method, using DO7 and 1801 which have been shown to be highly specific for p53 protein by immunohistochemistry and western blot analysis. The lower threshold of the assay is 0.1 ng/ml analyte in an enriched recombinant p53 preparation. As p53 is now regarded as a protein associated with prognosis in breast and other cancers, the assay may have clinical applications.

Antibodies, Monoclonal↗

PubMed1996

Cell adhesion molecules in bladder cancer: soluble serum E-cadherin correlates with predictors of recurrence.

Sera from 40 patients with newly diagnosed bladder cancer (28 superficial tumours (pTa and pT1) and 12 muscle-invasive tumours) were assessed by enzyme-linked immunosorbent assay (ELISA) to determine the concentrations of soluble E-cadherin (sE-cadherin), soluble E-selectin (sE-selectin), soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1). Corresponding frozen sections of primary tumour were analysed for E-cadherin expression using the monoclonal antibody, HECD-1 and standard immunohistochemistry. Patients with bladder cancer had significantly higher concentrations of sE-cadherin compared with a control group (P = 0.017). No difference was found between the two groups with regard to sE-selection (P = 0.403), sVCAM-1 (P = 0.942) and sICAM-1 (P = 0.092). High levels of sE-cadherin were related to poor histological grade (P = 0.009), number of superficial tumours at presentation (P = 0.008) and a positive 3 month check cytoscopy in superficial disease (P = 0.036). Abnormal E-cadherin expression was associated with increasing tumour stage (P = 0.009) and grade (P = 0.03). There was no correlation between high levels of soluble E-cadherin in sera and abnormal E-cadherin expression by the tumour (P = 0.077). Elevated levels of sE-cadherin are found in sera of patients with bladder cancer and correlate with known prognostic factors.

Aged↗

PubMed1992

A difficult intubation--fatal respiratory arrest secondary to an oral epulis.

We report an unusual case of cardio-respiratory arrest and eventual death secondary to a benign tumour of the oral cavity obstructing the oropharynx. We review the literature of similar occurrences causing difficulty with respiration and intubation, and highlight the importance of early diagnosis and treatment.

Aged↗

PubMed1990

The obstetric forceps--are we using the appropriate tools?

A total of 166 pairs of obstetric forceps of three different types in regular use in two major obstetric units was measured and compared with manufacturers' master instruments and drawings. As well as linear measurements of blade, shank and handle the distances between the tips and maximum distance between the blades, and the mean radius of the cephalic curve were determined. The purpose of the study was to assess the suitability of instruments in common use for present day practice. It was found that the measurements differed significantly from the original descriptions and there were wide variations between instruments of the same type, even when supplied by the same manufacturer. In some cases the blades had not been packed in matching pairs in the Central Sterile Supplies Department. It is suggested that critical reappraisal of the forceps in current use in many obstetric units is overdue. As well as a need for reconsidering the type of forceps used the dimensions of individual pairs should be checked.

Equipment Design↗

PubMed1989

Iron deficiency in pre-menopausal females.

Of 20 women (pre-menopausal) with iron deficiency anaemia, only three felt that their periods were unduly heavy. However, on objective assessment of menstrual loss using the alkaline haematin method, the blood was found to be excessively heavy in 12 cases (296 +/- 45 mls per cycle: normal is 80 mls/cycle). The findings emphasise that women underestimate the extent of menorrhagia.

Adolescent↗

PubMed1988

A device for measurement of radius of curvature of obstetric forceps.

Details of the design of obstetric forceps are important to ensure that they can be used safely for mother and baby. One of the most important measurements is the radius of the cephalic curve of the blades since if this is inappropriate there will be a poor grip on the baby's head and risk of slippage, superficial injury or even intracranial haemorrhage and brain damage because of undue compression. Because of the complex design of the forceps blades, which have a pelvic curve as well as a cephalic curve and a fenestra, the radius of the cephalic curve is difficult to measure. A device was designed to facilitate this measurement and was found to be accurate and reliable in use. This was the first stage in the study to assess the suitability for modern practice of instruments designed many years ago.

Equipment Design↗