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Biomedical subjects

M Farquharson

Publications and source records attributed to M Farquharson.

13 recordsLinked to original sources
PubMed2004

Late-onset fistula presenting as buttock abscess in two patients with ileo-anal J-pouches for ulcerative colitis.

Two cases are described of patients who presented with a buttock abscess 3 and 5 years after restorative proctocolectomy for ulcerative colitis. In both the abscess was secondary to a fistula, which was shown on further investigation to be a track traversing the greater sciatic notch. Both patients had had an ileo-anal J-pouch after a proctectomy which had included a mesorectal excision. The possibility that these unusual fistulae might be more common following removal of the mesorectum rather than a close rectal dissection is explored.

Abscess↗
PubMed2000

CT assessment of tumour response to treatment: comparison of linear, cross-sectional and volumetric measures of tumour size.

Changes in cross-sectional area are currently used to assess tumour response to treatment. The aims of this study were to validate a helical CT technique for volume determination using a series of phantoms and to compare tumour responses indicated by one-, two- and three-dimensional measures of tumour size change in patients treated for germ cell cancer or lymphoma. All studies were performed on an IGE HiSpeed Advantage helical CT scanner with an Advantage Windows workstation. Phantom volumes were calculated using volume reconstruction software and compared with reference volumes determined by water displacement. 20 lymph node masses were studied on serial CT scans in 16 patients treated with chemotherapy for germ cell cancer or lymphoma. For each lesion the maximum diameter, maximum cross-sectional area and volume were determined before and after treatment. Tumour response was assessed using the standard World Health Organisation criteria (i.e. changes in cross-sectional area) and the newly proposed unidimensional response evaluation criteria in solid tumour (RECIST). The CT volume measurement error was 1.0-5.1% for regularly shaped phantoms larger than 35 cm3. In the assessment of treatment response there was 90% agreement between one-dimensional (1D) and two-dimensional (2D) measurements and 100% agreement between 2D and three-dimensional (3D) measurements. CT volume measurements are accurate and reproducible, particularly for larger structures. Assessment of tumour response using 1D, 2D and 3D measures had limited influence on the classification of treatment response. However, the impact of CT assessment of tumour response using 1D, 2D and 3D measurements on clinical decisions and patient outcome remains to be determined.

Adult↗
PubMed1998

Fine-needle aspiration cytology of extranodal lymphoma.

The assessment of lymphoproliferative disorders using fine-needle aspiration (FNA) cytology may be problematic particularly when organs other than lymph node are involved. In this report we have reviewed 26 consecutive FNA specimens from superficial extranodal sites which were reported as diagnostic or suggestive of malignant lymphoma. The aspirates were obtained from skin or subcutaneous tissue (ten cases), thyroid (five cases), salivary gland (five cases), breast (four cases), neck, and pharynx (one case each). Ancillary studies including immunocytochemistry, in situ hybridisation to detect immunoglobulin light chain mRNA expression, and polymerase chain reaction for analysis of immunoglobulin heavy chain gene rearrangement were performed in 20, 12, and 7 cases, respectively. Clinicopathologic correlation confirmed the diagnosis of lymphoma in 25/26 aspirates. Nine of the 14 patients whose initial presentation was with an extranodal mass were considered to have primary lymphomas of mucosa-associated lymphoid tissue (MALT) type. In contrast, ten of 11 patients with recurrent extranodal disease had primary nodal type lymphomas. There was one false-positive diagnosis, a neck mass misinterpreted cytologically as B-cell lymphoma which was ultimately shown to be a branchial cyst. FNA cytology supported by appropriate ancillary investigations provides accurate diagnosis in most cases of extranodal lymphoma.

Adult↗
PubMed1998

Fine needle aspiration cytology diagnosis of malignant lymphoma and reactive lymphoid hyperplasia.

AIMS: To assess the diagnostic accuracy of lymph node fine needle aspiration (FNA) cytology to distinguish reactive lymphoid hyperplasia from malignant lymphoma, and to evaluate the contribution of ancillary techniques applied to cytological material. METHODS: Two hundred and seventy seven consecutive lymph node FNA specimens reported to be consistent with reactive lymphoid hyperplasia (n = 213) or suggestive/diagnostic of malignant lymphoma (n = 64) were reviewed. Follow up data were obtained by case record review or by histological correlation. The value of immunocytochemistry, in situ hybridisation for immunoglobulin light chain mRNA, and polymerase chain reaction (PCR) towards the final clinicopathological diagnosis was assessed in 92, 61, and 45 cases, respectively. RESULTS: Sixty one of 67 lymphomas and 207 of 209 reactive lymph nodes were accurately diagnosed by FNA cytology. There were six false negative aspirates including three cases of follicular lymphoma, two cases of Hodgkin's disease, and one chronic lymphocytic leukaemia. Two FNA specimens considered suspicious of lymphoma proved reactive on histology or clinical follow up. One metastatic small cell carcinoma was wrongly diagnosed as lymphoma. Ancillary studies contributed to the correct diagnosis in most cases although occasional misleading results were obtained, particularly with PCR. CONCLUSIONS: FNA cytology accurately distinguished reactive lymphoid hyperplasia from malignant lymphoma in 97% of cases. However, occasional wrong diagnoses occurred owing to sampling error or misinterpretation. Ancillary studies can be applied to cytological samples and contribute to the diagnosis in most cases.

Adult↗
PubMed1997

The association between tumour progression and vascularity in the oral mucosa.

Tumourigenesis in experimental models is associated with the formation of new blood vessels (angiogenesis). Recent studies have suggested that tumour angiogenic activity may be inferred in histological sections by measuring the density of the vasculature. The purpose of this study was to determine whether the transition from normal to dysplastic and neoplastic tissue in the oral mucosa is accompanied by quantitative or qualitative changes in the vascularity of the tissue, and how the estimate of vascularity is influenced by the vessel marker and method of assessment. A total of 100 specimens of normal oral mucosa, dysplastic lesions, and squamous cell carcinomas were examined. Sections were immunostained with the pan-endothelial antibodies to von Willebrand Factor (vWF) and CD31, or with an antibody to the alpha v beta 3 integrin, previously reported to be a marker of angiogenic vessels. Vascularity was quantitated by two different methods: highest microvascular density (h-MVD) and microvascular volume, as determined by point counting (MVV). The results showed that vascularity, measured by the MVV method using antibodies to either vWF or CD31, increased significantly (P < 0.0001) with disease progression from normal oral mucosa, through mild, moderate, and severe dysplasia to early and late carcinoma (76 paraffin-embedded tissues examined). In contrast, h-MVD did not discriminate between dysplastic lesions and carcinoma. A similar percentage of the total vessel volume (MVV) and density (h-MVD) were positive for alpha v beta 3 in 24 frozen tissues examined, including normal oral mucosa. It is concluded that there is a close association between vascularity and tumour progression in the oral mucosa. Morphometric analysis reflecting microvascular volume is more informative than the currently popular analysis of microvascular density. The expression of alpha v beta 3 in the vasculature of oral tissues does not necessarily reflect the presence of angiogenic vessels.

Carcinoma, Squamous Cell↗
PubMed1995

A CCD based focal spot camera.

Rapid, quantative assessment of x-radiation source intensity distributions would be useful in several areas of radiation physics. A simple x-ray sensitive CCD based camera for the measurement of focal spot and radiation beam intensity profiles has been constructed. Focal spot images recorded with the CCD camera and radiographic emulsion are compared and the advantage of the CCD camera in rapidly recording true radiation intensity distributions is demonstrated.

Photography↗
PubMed1994

p53 immunoreactivity in cervical intraepithelial neoplasia and non-neoplastic cervical squamous epithelium.

AIMS: To determine the pattern of p53 immunoreactivity in cervical squamous epithelium and to investigate the relation between p53 immunostaining and human papillomavirus (HPV) infection. METHODS: Immunocytochemistry for p53 was performed in 65 specimens of formalin fixed, paraffin wax embedded cervical tissue using a polyclonal antibody against recombinant p53. Microwave oven heating was used for antigen retrieval. Eight normal biopsy specimens, eight cases with histological features of HPV infection, and 49 cases of cervical intraepithelial neoplasia (CIN) were examined. Thirty one cases of CIN were examined. Thirty one cases of CIN were examined for evidence of HPV infection using in situ hybridisation with probes directed against wide spectrum HPV, HPV 16 and HPV 18. RESULTS: p53 immunoreactivity was seen in seven of eight (87%) of specimens with histological features of HPV infection, five of eight (62%) normal specimens, 13 of 22 (59%) CIN III, three of 14 (21%) CIN II and five of 13 (38%) CIN I specimens. The numbers of positive nuclei were small in cases of CIN and the location of positive nuclei within the epithelium paralleled the degree of dysplasia. Eleven of 15 (73%) CIN specimens which were immunoreactive for p53 yielded a positive signal for HPV by in situ hybridisation. A positive signal for HPV was also seen in 10 of 16 (63%) of CIN specimens in which p53 staining was absent. CONCLUSIONS: p53 immunoreactivity can be demonstrated in a small proportion of cells in the cervical squamous epithelium in a significant proportion of cases of CIN. This immunoreactivity seems to be independent of the presence of HPV, as assessed by in situ hybridisation. p53 immunoreactivity also occurs in non-neoplastic cervical squamous epithelium with a pattern of distribution within the epithelium which differs from that seen in CIN. Antigen retrieval by microwave oven heating enhances p53 immunostaining and may result in visualisation of cellular p53 in the absence of mutation.

Cervix Uteri↗
PubMed1990

Detection of messenger RNA using a digoxigenin end labelled oligodeoxynucleotide probe.

A synthetic oligodeoxynucleotide sequence complementary to the mRNA for the adrenocorticotrophin (ACTH) precursor pro-opiomelanocortin (POMC) was end labelled using digoxigenin. The probe was used to detect POMC mRNA both on nitrocellulose filters and by non-isotopic in situ hybridisation (NISH) in tissue sections. Digoxigenin was identified using anti-digoxigenin alkaline phosphatase. The model system examined was the rat pituitary gland. Removal of both adrenal glands and dexamethasone administration were used to change the concentrations of POMC mRNA in the rat anterior lobe. The labelled probe reacted with a single band of appropriate molecular weight in Northern blot analysis. The distribution of signal in tissue sections and the changes induced by experimental manipulation were as predicted. The results indicate that this method of NISH will prove useful in the detection of specific messenger RNAs in tissue sections of buffered, formalin fixed, paraffin wax embedded material.

Animals↗
PubMed1988

Class II MHC expression in normal adrenal cortex and cortical cells in autoimmune Addison's disease.

It has been proposed that aberrant expression of class II major histocompatibility complex (MHC) molecules by target cells may be an initiating factor in some forms of organ specific autoimmunity. This hypothesis was tested in relation to the autoimmune form of Addison's disease by studying autopsy adrenal glands from eight patients who had died of recent onset idiopathic Addison's disease. Using an immunohistochemical technique, class II MHC expression was found in a minority of adrenal cortical cells in the zona reticularis in 25 normal and four hyperplastic glands, while in Addison's disease almost all residual cortical cells expressed class II MHC. Three tuberculous adrenals showed increased staining of cortical cells around areas of chronic inflammation. It is concluded that since adrenal cortical cells of the normal gland express class II MHC, aberrant expression of this product cannot be invoked as an initiating mechanism in autoimmune adrenalitis. The increased cortical expression of class II MHC seen in idiopathic Addison's disease and tuberculosis may be due to local release of lymphokines by inflammatory cells.

Addison Disease↗
PubMed1988

Localization of alpha-interferon in the human feto-placental unit.

The distribution of alpha-interferon in human placental tissue was investigated by immunocytochemical study of paraffin wax-embedded tissue sections using a sheep alpha-interferon antiserum. Fifty-eight placentas of gestational ages from 8 to 40 weeks were examined. alpha-Interferon was present in the syncytiotrophoblast of the chorionic villi of all placentas and was also in macrophages in 28 cases. The appearances suggest production of interferon in human placental trophoblast and, in view of its diverse biological effects, support the concept of a role for alpha-interferon in the complex series of events required for successful gestation.

Chorionic Villi↗
PubMed1983

Liver membrane antibodies in alcoholic liver disease. II. Antibodies to ethanol-altered hepatocytes.

Using an indirect immunofluorescence technique, circulating liver membrane antibodies against normal rabbit hepatocytes and ethanol-altered rabbit hepatocytes have been sought in a series of patients with histologically confirmed alcoholic liver disease. Liver membrane antibodies against normal hepatocytes were found in 18 (28%) of the 65 sera examined, but with ethanol-altered hepatocytes as substrate liver membrane antibodies were found in 48 (74%) of the sera. Isolation of F(ab')2 fragments confirmed that the positive results were due to antibody binding. Liver membrane antibodies against ethanol-altered hepatocytes are peculiar to alcoholic liver disease, and there is a similar incidence in the various histological types of alcoholic liver disease. Absorption studies suggest that the liver membrane antibodies are directed against new or altered antigens which are not present in normal hepatocytes. These new or altered antigens may also appear after pretreatment with other primary alcohols and seem likely to be induced by a haptenic effect of the alcohol or a metabolic break-down product. These studies represent a novel approach to the further investigation of the possible role of immunological mechanisms in alcohol-induced liver injury.

Absorption↗