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Biomedical subjects

P J Sykes

Publications and source records attributed to P J Sykes.

10 recordsLinked to original sources
PubMed1992

Rapid method for detecting monoclonality in B cell lymphoma in lymph node aspirates using the polymerase chain reaction.

AIMS: To use the polymerase chain reaction to detect monoclonality at the immunoglobulin heavy chain gene locus in cells derived from lymph node aspirates. METHODS: A nested two-stage polymerase chain reaction (PCR) for the VDJ region of the immunoglobulin heavy chain gene was used to detect monoclonality. The total number of cells available for diagnosis by PCR in lymph node aspirates was between 10(4) and 10(5). RESULTS: A monoclonal band was detected in 21 of 25 malignant B-lymphomas. The other four specimens gave polyclonal bands. Specimens from reactive lymph nodes produced polyclonal bands in 14 cases, no product in two cases, and one specimen gave two monoclonal bands. Polyclonal bands were obtained for three Hodgkin's lymphoma samples and five metastatic carcinomas. Four metastatic carcinoma samples gave no amplification. CONCLUSIONS: Detection of monoclonality in a cell population is strongly suggestive of malignant disease. The simple PCR method presented here should complement conventional cytological and immunological methods for diagnosis of malignancy by lymph node aspirates.

Base Sequence↗
PubMed1992

Quantitation of targets for PCR by use of limiting dilution.

We describe a general method to quantitate the total number of initial targets present in a sample using limiting dilution, PCR and Poisson statistics. The DNA target for the PCR was the rearranged immunoglobulin heavy chain (IgH) gene derived from a leukemic clone that was quantitated against a background of excess rearranged IgH genes from normal lymphocytes. The PCR was optimized to provide an all-or-none end point at very low DNA target numbers. PCR amplification of the N-ras gene was used as an internal control to quantitate the number of potentially amplifiable genomes present in a sample and hence to measure the extent of DNA degradation. A two-stage PCR was necessary owing to competition between leukemic and non-leukemic templates. Study of eight leukemic samples showed that approximately two potentially amplifiable leukemic IgH targets could be detected in the presence of 160,000 competing non-leukemic genomes. The method presented quantitates the total number of initial DNA targets present in a sample, unlike most other quantitation methods that quantitate PCR products. It has wide application, because it is technically simple, does not require radioactivity, addresses the problem of excess competing targets and estimates the extent of DNA degradation in a sample.

Base Sequence↗
PubMed1979

The use of free microvascular flaps in the leg. Their value in orthopaedic surgery.

After discussing the conventional techniques available for covering skin defects in the leg with associated complex orthopaedic problems the value of the free flap is empahsised. The technique is discussed briefly and six cases are presented. The advantages of this method are outlined and the improvement in healing afforded by the extra blood supply in cases where there is infection and exposure of bone or plate is stressed. Where large complicated skin defects can be predicted, early co-operation between orthopaedic and plastic surgeons is advised.

Adult↗
PubMed1978

Microvascular second toe transfer for digital reconstruction.

Reconstruction of a severely damaged hand, with multiple amputations of digits, presents a difficult reconstructive problem. The development of a safe method of transfer of the great toe for thumb reconstruction, using the dorsalis pedis artery and the saphenous vein, suggested the possibility of one-stage microvascular transfer of the second toe for reconstruction of fingers. In two patients a one-stage transfer of the second toe was done to replace an index finger and in another for restoration of part of the left ring finger. The transplants survived without anticoagulants and vessel complications were not encountered. Sensory return was adequate and a significant improvement in function was achieved.

Accidents, Occupational↗
PubMed1978

The use of marsupial x eutherian somatic cell hybrids to study marsupial cell surface antigens.

Buck and Bodmer (1976) have developed a technique for identifying an antigen on the surface of human x mouse somatic cell hybrids, specified by a gene on a particular human chromosome. We have successfully adapted this technique to a study of marsupial cell surface antigens. Somatic cell hybrids between Macropus rufus (Marsupialia) lymphocytes and the mouse cell lines PG19 and 1R were injected intraperitoneally into mice of the same inbred strain from which the above cell lines were derived (C57B16J and C3H, respectively). The only identified M. rufus chromosome present in the hybrid cells was the X chromosome. The antisera, after adsorption with PG19 or 1R, were tested using indirect immunofluorescence, against the hybrid cells, and also against sub-clones (derived from hybrids) which had apparently lost the M. rufus X chromosome, or at least its long arm. The results of these tests showed that the absorbed antisera contained reactivity against an M. rufus cell surface antigen (or antigens). The reactions of one of the antisera were most simply interpreted by supposing that it was detecting an M. rufus X-lined antigen(s).

Animals↗
PubMed1976

Lymphaticovenous anastomosis by microvascular technique.

After developing some basic techniques of lymphaticovenous anastomoses in 60 dogs, a further study of these anastomoses in the greyhound was performed with a patency rate of 74 per cent a 1 week and 66 per cent between 6 and 12 weeks. Points of technique and causes of failure are discussed. The use of this method in the treatment of early secondary lymphoedema is mentioned.

Animals↗