Synchronous diagnosis of colorectal malignancy and lymphoma.

AIM: To perform case series from one centre over 9 years, and review of the literature. The synchronous diagnosis of colorectal malignancy and lymphoma is rare. METHOD: Case note review of patients identified from clinical databases. RESULTS: Five patients were identified and findings discussed. In two patients colorectal malignancy staging CT scans identified pathological lymphadenopathy consistent with lymphoma. A further two patients had an incidental lymphoma on histological examination of the colorectal malignancy specimen. The fifth patient was found to have suspicious superior mesenteric lymph nodes at laparotomy. Histology confirmed two nodular lymphocyte-predominant Hodgkin's lymphomas, a lymphocytic-rich classical Hodgkin's lymphoma, a diffuse large B-cell lymphoma and a B-cell follicular lymphoma. CONCLUSION: There is a need for vigilance for the possibility of dual pathologies in all specialties.

Consistency in the observation of features used to classify duct carcinoma in situ (DCIS) of the breast.

AIM: To determine interobserver and intra-observer agreement in the assessment of cytological grade and intraduct necrosis in pure duct carcinoma in situ (DCIS) of the breast. METHODS: Sixty unselected cases with illustrated diagnostic criteria were circulated to 19 practising histopathologists. RESULTS: Overall agreement was moderate for cytological grade in three categories: 71% agreement; weighted kappa (kappa w), 0.36; intraduct necrosis in three categories (absent, present, extensive): 76% agreement; kappa w, 0.57; and the Van Nuys classification system: 73% agreement; kappa w, 0.48. Agreement was no better among observers participating in the National External Quality Assurance Programme. Intra-observer agreement for cytological assessment (69.6% agreement; kappa w, 0.52) and intraduct necrosis (68.3% agreement; kappa w, 0.48) was moderate, suggesting that individual variation rather than precision of criteria contributes to the lack of agreement. CONCLUSIONS: Moderate agreement on observations can be achieved by non-specialist pathologists, with better agreement on necrosis than cytological grade. There was evidence of consistent individual bias towards over or under scoring cytological grade, which could be corrected with adequate and prompt feedback.

In-situ simulation of one-piece metacarpophalangeal joint implants using finite element analysis.

Generally, reconstruction of the rheumatoid metacarpophalangeal (MCP) joint is achieved by means of implantation of a hinged silastic prosthesis. Whereas these implants restore some degree of mobility to the joint, they are prone to failure after a relatively short life-span, and little is known about their dynamical behaviour within the joint. In this study, the Swanson and Sutter designs of MCP implant were examined in an idealized joint environment by means of two-dimensional finite element analysis. The purpose was to assess how the differing geometry affected their behaviour as replacement joints, and whether they were inherently prone to abrasion and high stress concentrations during flexion. The results revealed the changing points of contact between the implant and the bone ends, and clearly showed the implant stems 'pistoning' in the intramedullary canals. This was found to be an effective way to provide preliminary information on the dynamic behaviour of an implant in a simulated joint. This would facilitate further optimization of design in advance of fabrication.

The virtual hand. The Pulvertaft Prize Essay for 1996.

Virtual reality technologies are now at a stage in which the various disciplines can be brought together to construct a virtual human hand. Devices can be constructed to record multiple joint positions accurately in clinical environments. Joint prostheses may be tested virtually before undergoing clinical trials, albeit in a simple way at present, but may eventually be incorporated into a virtual model of the hand and driven by goniometric gloves. This will allow more detailed analyses of implant in situ behaviour. These exciting developments will provide a huge advance in our understanding of the functions of the real hand and also a potential way of assessing outcomes in a simple and repeatable fashion. We are on the edge of a new era in hand surgery when the computer scientist, biomechanic, control engineer, hand therapist and surgeon will be able to alternate between the virtual and the real world in producing better outcomes for patients.

Computer model analysis of the Swanson and Sutter metacarpophalangeal joint implants.

A representative model which mimics the behaviour of Silastic finger metacarpophalangeal joint implants was constructed using a finite element software package. The modelled implants were moved through a range of flexion, lateral deviation and a combination of both. Pistoning of both implants stems occurred within the modelled medullary cavities. For equivalent flexion angles, the Sutter implant produced a higher stress field than the Swanson implant, and the field was positioned at the central hinge mechanism. In both implants, lateral deviation increased the internal stress concentrations more than when pure flexion was applied. Overall the Swanson style of implant had lower stress magnitudes than the Sutter implant, and it is predicted that the Sutter implant will be more likely to fail than the Swanson. The failure mode for the Sutter implant would be at the central hinge region. The Swanson implant is likely to fail at the central hinge-stem interface regions.

A goniometric glove for clinical hand assessment. Construction, calibration and validation.

The construction of a goniometric glove is described. Each of the sensors in the glove was calibrated over a custom built metal hand using blocks of known angles as angular references. The digital data output from each sensor of the glove were converted into angular displacements at each joint. The glove was validated for consistency of measurement and accuracy over a custom built metal jig and in the human hand. The accuracy of the glove was found to be within the limits of traditional goniometry. It is proposed that goniometric gloves could be useful in the assessment of hand function.

An examination of one-piece metacarpophalangeal joint implants using finite element analysis.

Reconstruction of the rheumatoid metacarpophalangeal (MCP) joint is generally achieved by means of implantation of a hinged silastic prosthesis. These implants reduce the pain in joint and restore some degree of mobility. However, they are prone to failure after a relatively short life-span. In this study, two popular designs of MCP implant, the Swanson and the Sutter, were compared by means of three-dimensional finite element analysis. The aim was to examine how the differing geometry effected their relative stiffness as replacement joints, and whether they were inherently prone to high stress concentrations during flexion. Although the Swanson design implant exhibited relatively greater resistance to flexion, both designs showed regions of high stress concentration and it was noted that neither was without its limitations. The use of the finite element technique was found to be an excellent way to provide preliminary design evaluation information, allowing further evolution before clinical trials.

Oncoprotein p53 expression in normal, immortalized, and transformed mouse fibroblasts.

We have compared the rate of synthesis, half-life, and steady-state content of the oncoprotein p53 in logarithmically growing cultures of (a) primary embryo, (b) immortalized but untransformed, and (c) spontaneously transformed mouse fibroblasts. Steady-state p53 content derived from metabolic labeling and immunoprecipitation data revealed either no change or only a slight decrease (up to 1.5-fold depending on the antibody used) in transformed cells compared with immortal or primary cultures, p53 showed the same short half-life in all cell types. In contrast, immunocytochemical analysis of p53 content in intact cells demonstrated an increase in the proportion of cells with detectable nuclear p53 from approximately 4% in primary and immortal cultures to approximately 10% in fully transformed cells, together with a marked increase in the intensity of nuclear positivity. We suggest that transformation is associated with an increase in the cellular content of p53 in a subcellular pool which was not detectable in detergent for immunoprecipitation. In addition, immunocytochemical analysis demonstrated a marked heterogeneity in p53 content in all cell types which was not related to clonal variation, cell cycle phase, or growth state. These data challenge previous suggestion regarding the role of p53 in growth control.

Trans-osseous passage of head and neck brachytherapy tubes.

Brachytherapy following surgical resection of head and neck malignancy is a useful adjunct if full dose external beam radiotherapy has been performed previously. Percutaneous tube placement has been described but accurate placement can be technically difficult in certain areas of the head and neck. A case report is presented of trans-osseous brachytherapy tube placement through the zygoma bone to allow for optimum surgical bed irradiation without kinking of the tubes. It is proposed that the trans-osseous placement is a useful technique when siting of the tubes is difficult.

Collision tumour of the ampulla of Vater: carcinoid and adenocarcinoma.

Obstructive jaundice is most commonly due to luminal stones or lesions of the head of the pancreas and more rarely ampullary and primary common bile duct lesions. Obstruction due to lesions of the ampulla of Vater may be due to adenocarcinoma which has a significantly better long term prognosis than carcinomas located in the head of the pancreas. A case is presented where two tumours were identified at the ampulla of Vater of the resected specimen one an adenocarcinoma and the other a carcinoid tumour representing a collision tumour.