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Biomedical subjects

P H Whitehead

Publications and source records attributed to P H Whitehead.

At least 19 recordsLinked to original sources
PubMed1991

The clinical expression of bullous pemphigoid is not determined by the specificity of the target antigen.

The major bullous pemphigoid (BP) antigen is a 220-240-kDa polypeptide, although some BP sera recognize bands of 180-200 kDa or lower molecular weight. We have investigated to what extent this heterogeneity of the target antigen accounts for the clinical diversity of BP. Immunoblotting studies against extracts of salt-separated epidermis were performed on sera from 39 patients with BP. The blotting patters obtained were correlated with the clinical findings, with particular reference to prodromal itching, lesion morphology and severity, mucosal involvement, presence of milia, dapsone responsiveness and disease duration. The results confirm that the major BP antigen is a 220-kDa polypeptide, and that the 180-kDa polypeptide is a second and sometimes the sole BP antigen identified in immunoblots. Rarely, multiple bands of lower molecular weight were found. There was no correlation between the pattern of BP antigens detected in immunoblots and the clinical presentation and course of BP. There was considerable clinical diversity even among the nine patients showing specificity for a single 220-kDa target antigen. Although two patients with a single 180-kDa antigen specificity had a disease of unusually long duration, factors other than antigen specificity must determine the clinical expression of BP.

Aged↗
PubMed1979

New information from bloodstains.

The traditional philosophy behind the grouping of bloodstains in the Forensic Science Laboratory is described. It is emphasised that while these blood-grouping methods are highly discriminating in the sense that they may distinguish one person's blood from hundreds, or thousands of others, such information may be of limited value in many crime investigations. The reason for this is that such information does not normally relate to physical features of the individual with which we are all familiar such as sex or age. Recent research work is described in which efforts are being made to deduce from small bloodstains information which indicates the donor's sex, age, ethnic origin and perhaps clinical history.

Adult↗
PubMed1979

An improved means of enzyme typing of hair roots using isoelectric focusing.

An improved method of grouping hair, based on the alleles of PGM observed by isoelectric focusing, has been described. The increased discriminating power of this system (0.77) compared to that obtained by the starch gel technique (0.55) provides a new and more sensitive means of typing hair.

Electrophoresis, Starch Gel↗
PubMed1979

The detection of Y chromosomes in bloodstains--a reevaluation.

A method has been described for detecting Y chromosomes in the leukocytes of human bloodstains prepared on a variety of substrates. The factors that influence the proportion of chromosomes exhibiting a Y spot (the Y cell index) in a bloodstain are considered, including the subjective nature of assessment of the Y chromosome fluorescence, the substrate, and the age of bloodstain. In contrast to previous workers no decay in Y cell index with the age of the stain was observed. The results of a blind trial involving stains derived from case work, where from other evidence there was no doubt as to the sex of the donor, are presented. Sixty-five percent of the male bloodstains were correctly identified and no females were wrongly reported as male.

Blood Stains↗
PubMed1978

Enzyme typing of human hair roots.

Sufficient phosphoglucomutase activity was found to be present in plucked hair noses bearing either fragmentary or complete outer root sheaths to enable typing of individual roots by starch-gel electrophoresis. Hair roots collected by brushing were found to contain very little PGM activity. Other isoenzyme systems were detected in hair roots but in insufficient quantities to make typing feasible.

Densitometry↗
PubMed1975

The significance of amylase in forensic investigations of body fluids.

Amylase levels in body fluids are reported, and it is shown that high amylase levels may occasionally occur in body fluids other than saliva. Low amylase levels are reported in a saliva component which has been previously described as being rich in blood group active material. The use of amylase activity in the localisation and identification of saliva is discussed in detail and guidelines for the interpretation of results are proposed.

Amylases↗