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Biomedical subjects

I Stewart

Publications and source records attributed to I Stewart.

At least 37 records · Page 2Linked to original sources
PubMed1998

Chest computerized tomography scanning in patients presenting with head and neck cancer.

Between 1 to 16% of patients with head and neck squamous cell carcinoma (HNSCC) have synchronous tumours; the majority (> 50%) occurring within the lung. Previous studies have relied upon endoscopy and chest radiographs. The aim of this study was to determine the incidence of synchronous intrapulmonary tumours in this group of patients using computerized tomography (CT) scanning. Over 36 months, 111 consecutive patients were assessed at presentation by contrast enhanced CT scanning from the skull base to the diaphragm. Chest scans showed intrapulmonary lesions in 17 patients and 10 have, with time, been confirmed as neoplastic. These allowed treatment of three primary bronchial carcinomas following radical treatment of the index tumour and cancellation of radical treatment in five patients with metastases. Two patients with possible metastases at presentation underwent radical treatment to the index tumour with subsequent follow-up confirming metastatic chest disease. All 10 patients eventually died of either locoregional or metastatic disease. This is one of the first prospective reports of chest scanning in patients with head and neck cancer. An additional chest scan in this group, many of whom undergo a staging scan of the neck, requires an extra 10 min with no further contrast and in this study yielded a synchronous tumour rate of 9%.

Carcinoma, Squamous Cell↗
PubMed1996

Lego asthma.

Explore the source record for details and available documents.

Asthma↗
PubMed1996

Polymyalgia rheumatica is associated with both HLA-DRB1*0401 and DRB1*0404.

The frequency of HLA-DRB1 alleles was determined in 68 Caucasoid patients with polymyalgia rheumatica (PMR) and 140 controls using polymerase chain reaction (PCR) sequence-specific oligonucleotide typing. In keeping with previous studies, an increased frequency of DRB1*04 was observed in patients [55.9% vs 35.0%, odds ratio (OR) 2.4, 95% confidence interval (CI) 1.3-4.4]. HLA-DRB1*0101 frequency was also increased in patients, although less confidence could be placed on this association (19.1% vs 14.3%, OR 1.4, 95% CI 0.6-3.3). HLA-DRB1*04 subtyping indicated that the frequencies of both DRB1*0401 (38.2% vs 22.1%, OR 2.2, 95% CI 1.0-4.3) and DRB1*0404 (16.2% vs 5.0%, OR 3.7, 95% CI 1.2-11.1) were specifically raised. An increased frequency of the RA shared epitope (QKRAA/QRRAA) was also observed in this group (75.0% vs 44.2%, OR 3.8, 95% CI 1.9-7.6). When the analysis was restricted to only DRB1*04-negative patients and controls, the frequencies of DRB1*0301, *11 and *08 were marginally raised. However, no obvious relationship appeared to exist between PMR susceptibility and DRB1 alleles carrying the DYF conserved epitope in the second hypervariable region. Autoantibodies to thyroid antigens were present in 23% of patients. An increased frequency of DRB1*0301 was observed in patients with thyroid microsomal antibodies compared to those without (54.5% vs 24.6%, OR 3.7, 95% CI 0.8-17.0). This increase was not observed in patients with thyroglobulin autoantibodies. These data indicate that both DRB1*0401 and *0404 are associated with PMR, and that this may extend to include DRB1*0101. The immunogenetic profile of susceptibility markers in this condition appears to be similar to that in rheumatoid arthritis.

Aged↗
PubMed1996

The Measles/Rubella Immunisation Campaign in Greater Glasgow: a success in collaboration.

The recent UK campaign to immunise schoolchildren against measles and rubella involved, in Greater Glasgow, about 143,000 schoolchildren attending 300 primary, 63 secondary and 54 special schools administered by Strathclyde Regional Council and 21 private schools. The campaign involved a large number of individuals and professional groups, both in education and the health service. Despite-or perhaps because of-the magnitude and complexity of the task, and the very short time available, the campaign was planned and brought to a successful conclusion with a quite remarkable degree of enthusiasm and goodwill. As a result it was possible to immunise 88% of eligible schoolchildren in an area which has 46% of its population living in the most deprived postcode sectors (Carstairs categories 6 and 7) and to record all results on computer file as a permanent and readily accessible record. The campaign provided an unusual opportunity to demonstrate how effectively different organisations within the health service can collaborate with one another and with other agencies when there is a clear goal and deadline imposed.

Adolescent↗
PubMed1996

Prospective comparison of laparoscopy, ultrasonography and computed tomography in the staging of gastric cancer.

A total of 103 consecutive patients with gastric adenocarcinoma was assessed for intra-abdominal spread of malignancy using ultrasonography, computed tomography (CT) and laparoscopy under general anaesthesia. Histologically proven metastases were to the liver in 27 patients, lymph nodes in 49 and directly to peritoneum in 13. All modalities showed a high specificity (92-100 per cent) for each type of metastasis. Laparoscopy was more sensitive in detecting hepatic, nodal and peritoneal metastases; the relative performance of laparoscopy was best with regard to hepatic metastases. Ultrasonography and CT were particularly poor at detecting nodal and peritoneal metastases. There was no significant morbidity and no mortality associated with laparoscopy, which was more accurate in preoperative staging of gastric cancer than ultrasonography or CT.

Adenocarcinoma↗
PubMed1995

Swallowing performance following anterior cervical spine surgery.

The aim of this study was to assess the incidence and severity of dysphagia following anterior cervical spine surgery for cervical spondylosis. One-hundred patients were contacted 12-22 months following cervical spine surgery. Those reporting persistent swallowing impairment were invited to attend for further investigation. Of 73 respondents, 33 (45%) experienced postoperative dysphagia. This persisted for longer than 6 months in nine (12% of respondents). Of five subjects attending for investigation, none had a definite radiological abnormality. In contrast, manometry suggested hyperactivity of the pharyngo-oesophageal segment in these patients, although with normal co-ordination. Surgeons should warn of the risk of transient dysphagia in 45% of patients postoperatively and of its persistence in around 10%. Radiological examination may be normal and manometry is the investigation of choice. Persistent, severe dysphagia may be ameliorated by cricopharyngeal myotomy or pharyngeal dilatation.

Adult↗
PubMed1994

Decline in sperm counts: an artefact of changed reference range of "normal"?

OBJECTIVE: To investigate a reported fall in sperm counts during 1940-90 in relation to the reduced lower reference value of "normal" during the same period by assuming the null hypothesis that no change had occurred in the probability distribution of the sperm concentration. DESIGN: Analysis by using various mathematical models of the probability distribution of sperm concentration together with experimental data which supported a model employing a logarithmic distribution. SUBJECTS: 235 men presenting for stimulated in vitro fertilisation at Midland Fertility Services, Aldridge, in 1992 together with samples of 20 ejaculates from each of five men attending the same centre during 1992-3. RESULTS: The effect of the change in lower reference value for the "normal" sperm concentration (from 60 x 10(9) to 20 x 10(9)/l) depended on the probability distribution of the concentration in the population. If that distribution was normal or uniform, then very little of the reported decline was a consequence of the change in lower reference value. If it was heavily skewed, then most or all of the reported decline may have been a consequence of that change. The limited experimental data available indicate that the distribution was heavily skewed. CONCLUSIONS: Depending on the actual distribution of sperm concentration in the population, the reported decline in concentration may have been accounted for entirely or in part by the change in lower reference value. The original evidence does not support the hypothesis that the sperm count declined significantly between 1940 and 1990.

Humans↗
PubMed1994

A group-theoretic approach to rings of coupled biological oscillators.

In this paper, a general approach for studying rings of coupled biological oscillators is presented. This approach, which is group-theoretic in nature, is based on the finding that symmetric ring networks of coupled non-linear oscillators possess generic patterns of phase-locked oscillations. The associated analysis is independent of the mathematical details of the oscillators' intrinsic dynamics and the nature of the coupling between them. The present approach thus provides a framework for distinguishing universal dynamic behaviour from that which depends upon further structure. In this study, the typical oscillation patterns for the general case of a symmetric ring of n coupled non-linear oscillators and the specific cases of three- and five-membered rings are considered. Transitions between different patterns of activity are modelled as symmetry-breaking bifurcations. The effects of one-way coupling in a ring network and the differences between discrete and continuous systems are discussed. The theoretical predictions for symmetric ring networks are compared with physiological observations and numerical simulations. This comparison is limited to two examples: neuronal networks and mammalian intestinal activity. The implications of the present approach for the development of physiologically meaningful oscillator models are discussed.

Animals↗
PubMed1994

Scintigraphic appearances in patients with pulmonary infection and lung scintigrams of intermediate or low probability for pulmonary embolism.

Out of 294 patients with lung scintigrams of low or intermediate probability for pulmonary embolism, the appearances in 54 patients with a final diagnosis of pulmonary infection were reviewed. The most common finding was a matched defect in ventilation and perfusion occurring in 40 patients (76%). Regional reverse mismatch occurred in 13 patients (24%) and both appearances were found in one patient (2%). Reverse mismatch was also present in a further seven patients, four of whom had bronchial obstruction. Although occurring less frequently than matched defects, 81% of regional reverse mismatched defects were because of chest infection. The presence of regional reverse mismatch in patients investigated for pulmonary embolism suggests the alternative diagnosis of chest infection.

Adult↗