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Biomedical subjects

D N Slater

Publications and source records attributed to D N Slater.

At least 19 recordsLinked to original sources
PubMed2001

Tonsillar metastasis: A rare presentation of gastric carcinoma.

Metastatic carcinoma of the tonsil is uncommon. Tonsillar metastases rarely become apparent before the diagnosis of the primary neoplasm. We describe only the second reported case of tonsillar metastasis as a presenting feature of gastric carcinoma. A review of the literature is also discussed.

Aged↗
PubMed2001

Pseudomembranous esophagitis.

BACKGROUND: Little is known of pseudomembranous esophagitis, a condition of striking endoscopic appearance. Presented here is a description of its nature and outcome. METHOD: Information on all patients with upper GI disease seen in our unit are held in a computerized database that includes presentation, diagnosis (including pseudomembranous esophagitis), treatment, and outcome. RESULTS: Forty-eight patients (mean age 70 years) with pseudomembranous esophagitis were seen over 15 years; 42 were in-patients with various illnesses. At endoscopy, a thin, concentric membrane and/or thick slough covered the distal half and occasionally the entire esophagus. This layer, yellow or blackened, could be peeled away to reveal underlying friable esophageal submucosa. The membrane was composed of fibrinous exudate and inflammatory cells; there was no basement membrane, hence the term pseudomembrane. Patients were treated with histamine H2 receptor antagonists or proton pump inhibitors for about 3 months and followed by endoscopy or clinical observation. All became asymptomatic; the pseudomembrane had disappeared in 32 who underwent follow-up endoscopy. It recurred in 3 of 38 being followed (mean 3.2 years), again associated with another illness requiring hospitalization. The long-term outcome was poor, determined by age and general condition and independent of pseudomembranous esophagitis. Seven patients died within 3 months and 17 during follow-up (mean 42 months, range 5-140 months). CONCLUSION: Pseudomembranous esophagitis is an unusual condition of unknown cause, probably under-reported and associated with systemic illness. It heals rapidly and recurrence is uncommon.

Adolescent↗
PubMed2000

Assessing the conditions for in vivo electrical virtual biopsies in Barrett's oesophagus.

It has previously been shown that it is possible to differentiate between squamous and columnar epithelia in rat and resected human tissues using an impedance probe to make in vitro measurements. This probe can be passed down an endoscope allowing measurements to be made in patients. However, the probe emerges parallel to the oesophageal wall, with little room to manoeuvre. The conditions of control required to give reliable readings have been investigated. The importance of pressure applied and the angle of approach to the oesophagus was assessed. Pressures in the range 26.6 Pa to 46.3 kPa and angles in the range 15-90 degrees were considered. In in vitro studies it was observed that it was possible to obtain consistent readings with pressures greater than 2.9 kPa and with angles greater than 15 degrees between the probe and the oesophagus. These conditions can be achieved in vivo, and readings obtained from twelve patients are shown (45 readings on normal squamous, 34 on Barrett's oesophagus and 22 on stomach). At low frequencies (9.6-153.2 kHz), a Mann-Whitney test shows a significant difference (p < 0.001) when comparing the means from squamous and columnar, and also when readings from Barrett's and normal gastric epithelia are compared (p < 0.001).

Animals↗
PubMed2000

The effect of nonscreening smears on screening smear results: a statistical analysis with its implications for the NHS cervical screening programme.

This is a statistical analysis of individual NHS Cervical Screening Programme laboratories screening smear 'pick-up' rates (defined here as percentage low grade and percentage high grade of total adequate smears for ages 20-64 years derived from general practitioners and community clinics) in relation to their nonscreening smear workload proportion (here defined as percentage nonscreening smears of total laboratory workload from all sources for all ages). This was achieved by the use of three one way ANOVA models in order to receive a complete overview of the results. The models were applied to the following: (1) Laboratories with a total workload of less than 15000 general practitioner (GP) and community clinic smears; (2) laboratories with a total workload of greater than 15000 GP and community smears and; (3) all laboratories (i.e. a combination of 1 and 2). The 'test' groups within each of these models comprised three subgroups based on the percentage of laboratory workload that consisted of smears from a nonscreening source. This figure ranged from 2.8% to 82.6%. The subgroups were divided so as to contain approximately the same number of laboratories in each one (172 laboratories in total, 42 with workload < 15000 and 130 with > 15000). The results show that laboratories high and low grade pick-up rates have a positively correlated but variable relationship with the proportion of their workload that consists of nonscreening smears. The results show significance overall at the 5% level for high grade and the 10% level for low grade (high grade at P = 0.045 and low grade at P = 0.071). Significance for laboratories viewing less than 15000 screening smears at the 1% level (high grade P = 0.006 and low grade P = 0.005). They show no significance, however, for laboratories viewing more than 15000 screening smears (high grade P = 0.457 and low grade P = 0.622). There is an intriguing possibility that a greater exposure to abnormal smears results in a greater tendency to detect them. The current data provides no evidence to support the NHS Executive's use of 15000 as a designated figure when quality monitoring and service provision becomes a specific issue. The closure or amalgamation of laboratories with workloads less than this would appear to have no scientific evidence base.

Adult↗
PubMed2000

Are women sufficiently well informed to provide valid consent for the cervical smear test?

Three hundred women attending colposcopy for the first time, following an abnormal cervical smear, were invited to fill in a questionnaire. This covered aspects of their understanding of the cervical smear test and the NHS Cervical Screening Programme (NHSCSP). In addition, it covered aspects of consent to the test. The response rate was 83%. Seventy percent thought that the NHSCSP is working well and 72% were aware that probably over 3000 cases of cervical cancer per year are being saved by the NHSCSP. However, 55% did not know that the death rate from cervical cancer is decreasing. 96% were aware that the main reason for a cervical smear is to prevent the development of cervical cancer, by finding early treatable abnormalities. Similarly, 94% were aware that the presence of abnormal cells on a cervical smear indicated a possible but not definitive indication of cervical precancer or cancer. Disappointingly, only 5 had seen the new NHSCSP information poster on the cervical smear test and only 44% had been given written information about the test. Consent for the test in 59% of women had been implied rather than expressed and 30% of women providing expressed consent had signed to that effect. In 42% of women, the smear taker or a doctor had failed to discuss the reason for having a cervical smear and had not explained about its advantages and limitations. In 72%, the smear taker or doctor had not explained that the cervical smear test can never be 100% accurate and that some laboratory errors are unavoidable. It is likely that women attending for colposcopy are a highly motivated cohort in relation to their understanding of the cervical smear test and the NHSCSP. Accordingly, understanding in the more general female population is likely to be considerably less. It would appear that women are often suboptimally informed to provide valid consent for the cervical smear test.

Colposcopy↗
PubMed2000

What criteria reliably distinguish melanoma from benign melanocytic lesions?

The differential diagnosis of melanocytic lesions is fraught with difficulty and a common source of litigation either if a lesion misreported as 'benign' recurs locally or re-presents with nodal metastases or if an atypical naevus is called 'malignant' leading to a cosmetically unsatisfactory wider resection, unwarranted anxiety about prognosis and adverse life insurance prospects. Several authors have claimed that there are valid morphological criteria which, alone or in combination, enable reliable distinction between benign and malignant melanocytic lesions. Others question these criteria and, doubting the extent to which unequivocal diagnoses can be rendered in all cases, believe that the diagnosis is purely subjective and that most diagnostic errors are non-negligent. To address these issues, expert opinions were commissioned from three sets of authors. Okun, Edelstein & Kasznica emphasize that a significant minority of melanocytic lesions are so borderline morphologically that diagnostic uncertainty is allowable and that such uncertainty can be handled responsibly. Kirkham, in favouring the methodical use of criteria, concedes that they are 'largely opinion-based rather than evidence-based, but do go beyond mere subjective pattern analysis'. In agreement with Okun and his colleagues. Slater emphasises that no single feature is reliable by itself and that all aspects, including clinical details, should be interpreted together; he has no hesitation in reporting the diagnosis as 'uncertain' in doubtful cases. In the absence of a specific marker pathognomonic of melanocytic malignancy, the diagnosis will continue to rely on the judicious application of morphological criteria with a small proportion of elusive cases in which diagnostic uncertainty should not be concealed.

Biomarkers, Tumor↗
PubMed1999

Virtual biopsies in Barrett's esophagus using an impedance probe.

Preliminary results of electrical impedance measurements in squamous and columnar epithelia in rat and human tissues are presented. The aim of this work is to show the possibility of differentiating these two types of epithelia in terms of their electrical characteristics. For the measurements, we employed a 1.95-m-long, 3.2-mm-diameter, four-electrode probe designed to be used transendoscopically in the diagnosis of Barrett's esophagus (BE). BE is a condition in which the normal squamous epithelium of the esophagus is replaced by columnar epithelium of the intestinal type. This metaplasia is considered as a premalignant condition that puts patients at a 30-125-fold risk of developing adenocarcinoma of the esophagus. The diagnosis and surveillance of BE involve taking multiple biopsies, an expensive and time-consuming procedure. This study constitutes the first stage in the replacement of tissue biopsy by "virtual biopsies".

Animals↗
PubMed1999

Non-Langerhans cell histiocytosis associated with lymphocyte-predominant Hodgkin's disease.

We report a 74-year-old man who presented with a rash on the trunk showing clinical and histological features of non-Langerhans cell histiocytosis. Two years after presentation he developed weight loss, lymphadenopathy and hepatosplenomegaly; a diagnosis of lymphocyte-predominant Hodgkin's disease was made on lymph node biopsy. The cutaneous signs and lymphoma responded to chemotherapy. Taken in conjunction with previously published reports of associations between cutaneous histiocytoses and haematological malignancies, we recommend close observation of patients in whom a diagnosis of non-Langerhans cell histiocytosis is made.

Aged↗