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Biomedical subjects

A J Webb

Publications and source records attributed to A J Webb.

At least 19 recordsLinked to original sources
PubMed1992

Diagnostic and therapeutic aspects of fine-wire localization biopsy for impalpable breast cancer.

During the first 2 years (July 1989 to July 1991) of the Avon Breast Screening Service, fine-wire localization biopsy was indicated in 213 impalpable breast lesions. A total of 144 lesions were benign and 69 malignant. Only four of 213 lesions (1.9 per cent) were not excised at the first localization. Factors influencing reoperation in the 69 patients with malignant impalpable lesions were examined. There was a significant association (P < 0.001) between parenchymal disturbances on mammography and invasive carcinoma, and between non-invasive carcinoma and microcalcification (P < 0.001). In 31 patients the localization biopsy was the only surgical procedure. Thirty-eight patients required further surgery: 12 underwent further local excision and 26 mastectomy. Reoperation was more frequent in patients with calcification than in those with parenchymal disturbance (P < 0.001). The most frequent indications for mastectomy were inadequate excision of widespread comedo ductal carcinoma in situ or invasive ductal carcinoma combined with extensive ductal carcinoma in situ. Fine-wire localization biopsy was a combined therapeutic and diagnostic procedure in 31 of 69 women with impalpable screen-detected lesions. The majority of patients required further surgery because radiological abnormalities underestimated the extent of disease.

Biopsy, Needle↗
PubMed1991

Florid papillomatosis of the nipple: a clinico-pathological surgical problem.

Adenoma or florid papillomatosis of the nipple is a rare, benign condition which resembles the clinical appearances of Paget's disease of the nipple and the histological appearances of papillary carcinoma of the breast. We describe a case which illustrates the pitfalls in diagnosis and proposes a safe management procedure for breast and nipple lesions.

Breast Neoplasms↗
PubMed1989

Management of high grade parotid carcinomas.

Thirty-four patients admitted to the Bristol Royal Infirmary during the 20-year period 1966-85 and diagnosed as suffering from high grade parotid carcinoma were studied. The male:female ratio was 2.4:1, with a mean age at presentation of 68 years. Facial swelling was present in all patients with a mean duration of 9.9 months before treatment. Pain, deep fixation, facial nerve involvement, ulceration and distal metastases were all associated with a poor prognosis. Diagnosis was made either at operation or by fine needle biopsy. All 34 patients received radiotherapy. Fourteen patients (41 per cent) underwent a definitive surgical procedure. The local recurrence rates for the non-surgical and surgically treated groups were 30 per cent (six patients) and 36 per cent (five patients) respectively; twelve patients (60 per cent) in the non-surgical group developed distant metastases as opposed to six patients (43 per cent) in the surgical group. Both local and distant recurrent disease are indicators of poor prognosis, with only one patient alive at 104 months. Seven patients (21 per cent) remain recurrence free. Definitive surgery, combined with radiotherapy, improved survival in those with amenable localized disease.

Adult↗
PubMed1989

Beta-adrenergic responsiveness in stress-sensitive and stress-resistant pigs.

This study investigated whether enhanced metabolic responsiveness to beta-adrenergic stimulation might explain the liability of the stress-sensitive pig to develop an acidosis during stressful situations. Blood lactate, pH, PCO2 and heart rate response to an intravenous infusion of isoprenaline were examined in three lines of pentobarbitone anaesthetized, atropinized pigs. The lines were Pietrain X Hampshire which had been selected over eight generations for a positive reaction to the halothane test (stress-sensitive); Pietrain X Hampshire which had been selected over eight generations for no reaction to the halothane test (stress-resistant) and British Landrace which had been selected over four generations for a positive halothane reaction (stress-sensitive). The metabolic responses to isoprenaline were greater in the stress-sensitive Pietrain X Hampshire line than the stress-resistant line. The stress-sensitive Landrace pigs, however, had smaller changes in pH and PCO2 in response to isoprenaline than the stress-resistant Pietrain X Hampshire pigs. This inconsistent trend across the three lines led to the conclusion that enhanced beta-adrenergic responsiveness was not the likely cause of stress sensitivity.

Animals↗
PubMed1989

Impressions.

Explore the source record for details and available documents.

General Surgery↗
PubMed1987

Fine-needle aspiration biopsy and the diagnosis of thyroid cancer.

Conventional criteria for the evaluation of thyroid nodules are inaccurate in identifying the small proportion of malignant neoplasms. The diagnostic accuracy of fine-needle aspiration biopsy (FNAB) for cytology was therefore assessed in 562 patients with nodular thyroid disease, 373 of whom (66.4 per cent) had histological confirmation of the cytological diagnosis. Sixty-one aspiration biopsies were positive for malignancy, and the diagnosis was confirmed histologically in 59 of these (96.7 per cent). Thus, there were two false positive cytology results among 310 patients with proven benign disease (0.6 per cent). Four of sixty-three patients with proven carcinoma had a benign cytological diagnosis, a false negative rate of 6.3 per cent. In 57 of the 59 malignancies (96.6 per cent) correctly diagnosed by FNAB the histological type of tumour was successfully identified. Overall 367 of 373 patients received correct cytological discrimination between benign and malignant nodules, an overall accuracy of 98.4 per cent for FNAB. The sensitivity of the test was 93.7 per cent and the specificity 99.4 per cent. Besides being safe, cost-effective and reliable, FNAB directs the appropriate selection of patients for surgery and enables the correct operation to be performed for each type of tumour.

Adolescent↗
PubMed1987

Triggering of B lymphocytes through CD23: epitope mapping and studies using antibody derivatives indicate an allosteric mechanism of signalling.

By using five monoclonal antibodies in reciprocal cross-locking studies, a minimum of three epitope clusters have been defined for the B-cell restricted, activation-associated CD23 antigen. Two of the five antibodies were capable of replacing low molecular weight B-cell growth factor (BCGF) in B-cell co-stimulation assays. These two antibodies belonged to the same epitope group, while non-stimulatory antibodies fell outside this cluster. By prior coating of activated B lymphocytes at 4 degrees, all five CD23 antibodies interfered with the subsequent uptake of BCGF activity onto the cells. However, only the two stimulatory antibodies were capable of inhibiting the absorption of BCGF completely. From one of these antibodies, F(ab')2 and Fab fragments were generated and both were found to be equivalent to whole antibody in their ability to mimic BCGF. Immobilized antibody, however, failed to stimulate over a wide range of concentrations. These findings demonstrate that the ability of certain CD23 antibodies to deliver a growth-promoting signal to activated B cells is independent not only of the Fc portion of the molecule but also of receptor cross-linking. The latter observation is indicative of an allosteric mechanism of triggering, a notion supported by the epitope specificity of activation through CD23. The findings are discussed in relation to the putative natural ligands for CD23 and the way they may influence B-cell function through this receptor.

Antibodies, Monoclonal↗
PubMed1986

Adenolymphoma of the parotid: aetiology, diagnosis and treatment.

In order to study the changing clinical pattern, diagnosis and surgical treatment of adenolymphoma, the records of all 57 patients with a confirmed histological diagnosis, made at Bristol Royal Infirmary between 1951 and 1984, were reviewed; in 3 patients (5 per cent) bilateral lesions had been found. No characteristics emerged in a review of the history and clinical examination which would have enabled a correct preoperative diagnosis to be made. During the period of study the incidence of adenolymphoma increased 24-fold. (Parotid pleomorphic salivary adenomas increased in incidence by only 42 per cent over the same period). Before 1965 all patients were men; between 1965 and 1975 the male to female ratio was 3:1; between 1975 and 1985, 1.6:1. Of the 48 patients who had a relevant history taken 45 were smokers (93.8 per cent). It is postulated that tobacco consumption is important in the development of adenolymphoma, and has produced the changes in incidence and sex ratio. Fine needle aspiration biopsy cytology (FNAB) afforded the only method of achieving a pre-operative diagnosis. This was successful in 64.7 per cent. Superficial parotidectomy induced a 43 per cent incidence of facial nerve neurapraxia. Controlled enucleation reduced this to 8 per cent. Enucleation is the procedure of choice for adenolymphoma but can only be employed with confidence if an exact pre-operative diagnosis is made.

Adenolymphoma↗
PubMed1986

Evidence for an association between CD23 and the receptor for a low molecular weight B cell growth factor.

Low molecular weight B cell growth factor (BCGF) and a monoclonal antibody (MHM6) to the 45-kDa, B lineage-restricted, CD23 activation antigen (BLAST-2; EBVCS) were found to be indistinguishable in their biological effects. Individually, both augmented DNA synthesis in activated, but not resting, B lymphocytes while no additional enhancement resulted from using the two agonists in combination. Furthermore, by increasing the expression of Tac, both MHM6 and BCGF promoted activated B cells to respond more vigorously to the late addition of recombinant interleukin 2. The presence of BCGF during B cell activations was found to down-regulate the expression of the CD23 antigen while the coating of activated cells with MHM6 antibody diminished their capacity to absorb BCGF activity. The findings demonstrate that CD23 and a low molecular weight BCGF deliver a comparable growth-promoting signal to activated B cells. A possible relationship between CD23 and the receptor for the low molecular weight BCGF is discussed.

Antibodies, Monoclonal↗
PubMed1986

Does radiolabelled diphosphonate retention reflect bone metabolism in the elderly?

The 24-h whole-body retention of diphosphonates (WBR), a useful measure of bone metabolism in young subjects, was measured in 27 elderly subjects (19 from home and eight in-patients). WBR rose with increasing age (r = 0.55, P less than 0.01) and was negatively correlated with renal function (r = -0.60, P less than 0.01). In five subjects given vitamin D, WBR did not fall. The measurement of WBR in the elderly has to be assessed in the light of an accurate assessment of renal function and so is rarely clinically useful.

Aged↗
PubMed1985

Fine needle aspiration cytology.

Fine needle aspiration cytology is an inexpensive, atraumatic technique for the diagnosis of disease sites. This paper describes the technique and illustrates how it may be applied to the management of tumours throughout the body. The limitations of the method, the dangers of false positive reports, and the inevitability of false negative diagnoses are emphasised. In a clinical context the method has much to offer by saving patients from inappropriate operations and investigations and allowing surgeons to plan quickly and more rationally. It is an economically valuable technique and deserves greater recognition.

Abdominal Neoplasms↗
PubMed1977

Tumour detection by ultrasonic Doppler blood-flow signals.

Ultrasonic Doppler blood-flow signals which seem to be associated with malignant tumour neovascularization have been detected in the female breast. No such signals have been detected from cysts. This discovery may lead to the development of a highspeed ultrasonic Doppler scanner which might make breast screening for cancer practicable.

Adenofibroma↗