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Biomedical subjects

D Neilson

Publications and source records attributed to D Neilson.

At least 19 recordsLinked to original sources
PubMed1996

Kinetics of circulating TNF-alpha and TNF soluble receptors following surgery in a clinical model of sepsis.

The interrelationship between cytokines and their natural antagonists in patients with systemic sepsis are incompletely understood. We have followed the changes in serum levels of TNF-alpha and the two soluble receptors (TNF-sr) in a clinical model of post-operative sepsis. Serial blood samples were taken in patients undergoing percutaneous nephrolithotomy (PCNL) starting pre-operatively and continuing for 24 h thereafter. The levels of TNF-alpha and TNF-sr were raised in patients who became clinically septic and correlated well with the severity of sepsis (using the APACHE III score). In septic patients there was no difference in the pattern of changes in the two types of receptor (TNF-sr55 and TNF-sr75). However, in non-septic patients TNF-sr75 was higher in those with endotoxaemia than those without. This difference was not observed with TNF-sr55 which suggests a different mechanism of release or degree of sensitivity for the two soluble receptors. Regardless of severity of illness, the levels of all three molecules (TNF-alpha and the two receptors) appeared to start rising at about the same time point. The peak TNF-alpha level was reached earlier (2-4 h) than that of the two TNF-sr (4-8 h). The relative rise in TNF-alpha was greater than that of the soluble receptors and this difference was even more marked in those with more severe sepsis. The relationship between peak TNF-alpha and peak TNF-sr was non-linear and the concentration of each TNF-sr appeared to plateau at the higher levels of TNF-alpha. This suggests the exhaustion of a limited pool or saturation of the rate of release. Taken together, these results suggest sepsis develops because of delayed and insufficient secretion of TNF-sr compared with TNF-alpha.

Antigens, CD↗
PubMed1994

The ultrasonic diagnosis of infantile hypertrophic pyloric stenosis: technique and accuracy.

The role of ultrasound for the diagnosis of pyloric stenosis has yet to be definitely established. We have carried out 147 ultrasound examinations of 142 infants (99 male and 43 female) with a history of projectile vomiting or the possibility of a pyloric mass. Measurements of the pyloric canal length, transverse pyloric diameter and muscle wall thickness were taken from a longitudinal view of the pylorus and related to previously described control data. The accuracy of the ultrasound examination was related to the finally established diagnosis. The results obtained revealed a sensitivity of 97% and specificity of 99% with positive predictive value of 99%. The three diagnostic errors (1 false positive and 2 false negative) occurred during the 'learning curve' of the radiologists and were the 15th, 29th and 35th cases examined, indicating that almost a 100% accuracy can potentially be achieved. This study confirms that ultrasound examination is the first line of investigation in a child in whom the clinical diagnosis of hypertrophic pyloric stenosis is uncertain and indicates that unnecessary surgery can thereby be prevented.

False Negative Reactions↗
PubMed1992

Criteria for selective admission of patients with haematemesis.

A retrospective survey of 157 consecutive admissions for haematemesis was carried out in order to determine whether patients at low risk of adverse events could be identified at the time of admission from simple clinical features. In addition to known prognostic factors such as hypotension, tachycardia and anaemia, we studied the character of the vomit classified into altered or frank blood. Death, surgical intervention and transfusion of more than 2 units of blood were defined as 'adverse events'. No adverse event occurred in 37 patients who vomited only altered blood and who did not have melaena, or in 42 patients with a concentration of haemoglobin of 12 g/dl or more who vomited altered blood only. Classification by other prognostic criteria was not as sensitive. These results suggested that patients with haematemesis who have negligible risk of serious sequelae can be identified at an early stage in the course of their disease from simple features of clinical history and examination. Excessive use of resources should be avoided in such patients, and selective admission may be justified.

Blood Transfusion↗
PubMed1989

Severe mental disorder in Afro-Caribbean patients: some social, demographic and service factors.

Forty-two consecutively identified Afro-Caribbean patients with a first episode of psychosis were compared with a similar group of non-Caribbean patients. A number of differences emerged, although the same proportion of patients in each group had symptoms for 6 months or more prior to psychiatric contact. Afro-Caribbean patients showed greater delay in seeking help, more 'disturbance' later in the course of their illness and were more likely to be admitted compulsorily. The social geography of the two groups suggests that the high rates of schizophrenia and related psychoses that we previously reported cannot be explained simply by differences in area of residence at the time of presentation.

Adult↗