Biomedical subjects
Publications and source records attributed to C A Roobottom.
Inverting papilloma of the sinonasal cavity is of importance because of its association with squamous cell carcinoma and its tendency to local recurrence. Appearances of inverting papilloma have only been reported infrequently, and never in recurrent cases. We present the magnetic resonance imaging (MRI) appearances of four cases of inverting papilloma, three of which are recurrent.
In order to ascertain the national variation in practice and workloads amongst interventional radiologists a questionnaire was sent to all members of the British Society of Interventional Radiologists of three or more years standing. The questionnaire was designed to assess changes in workload and angiographic practice amongst members at the various institutions. Results indicate that, over the last five years, there has been a dramatic increase in both diagnostic and therapeutic procedures performed, with an overall doubling of workload. There are, however, wide variations in angiographic practice and technique and referral pattern.
The vast majority of glass and metallic foreign bodies can be detected with conventional radiography. The visibility of common woods and plastics is, however, unknown. To assess their radiographic visibility, various woods and plastics of equal size were inserted into fresh porcine tissue. The pork was then radiographed, under identical conditions, using conventional film-screen combination and a FUJI computed radiographic system utilizing its edge-enhancement facility. The visibility of the compounds was scored by four radiologists for both systems at various times post-insertion. Plastics were found to vary widely in visibility. Dried timbers were visible initially but became isodense with time due to absorption of fluid from surrounding tissues. Fresh woods were invisible from the outset. The computed radiographs improved the visibility of objects visible with conventional radiography but did not bring about visualization of those invisible to normal film-screen combinations. In conclusion the visibility of woods and plastics is variable. Some improvement in visibility can be brought about by the use of digitally edge-enhanced computed radiographs.
Two recent deaths from massive air embolism occurring while scuba diving off the South coast of Britain are reported. In each case the circumstances of death were uncertain. In both instances the cause of death, that is massive gas embolism, was determined by plain radiography and findings were confirmed at post-mortem. These cases illustrate that in unexplained deaths that occur after exposure to, or change in hyper- or hypobaric conditions, investigation should include pain radiographs of the chest, abdomen and skull.
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RATIONALE AND OBJECTIVES: Differences in leukocyte phagocytosis following exposure to different classes of radiographic contrast media (RCM) may help in the development of less toxic alternatives and be useful as a guide to contrast selection in certain patient groups. The effect of RCM on leukocyte phagocytosis of Escherichia coli was examined. METHODS: Cell population phagocytosis and individual cell phagocytic activity were assessed in a control group and in samples exposed both to the ionic RCM diatrizoate and ioxaglate and to the nonionic RCM iohexol and iotrolan by using a flow cytometer. RESULTS: The percentage of granulocytes undergoing phagocytosis was 88.4% in the control population. Following exposure to RCM, this value fell to 79.2% with iohexol, 77.6% with iotrolan, 70.5% with diatrizoate, and 68.7% with ioxaglate. The number of bacteria phagocytosed by active leukocytes was not affected by RCM. CONCLUSION: RCM adversely affect the percentage of granulocytes involved in phagocytosis but not the number of pathogenic bacteria that are phagocytosed by individual granulocytes.
RATIONALE AND OBJECTIVES: Studies describing the effects of radiographic contrast media (RCM) in leukocyte chemotaxis have been contradictory. No studies have been performed after in-vivo exposure. The authors assess the effect of RCM on leukocytes following in-vivo exposure. METHODS: Seventeen patients were studied after intraarterial bolus injection of 75 mL of iohexol (300 mg/mL) or iotrolan (300 mg/mL), 30 minutes and 24 hours postinjection; chemotaxis was assessed using an ex-vivo whole-blood under-agarose method. RESULTS: With iohexol, there was a profound reduction in chemotaxis compared with the preinjection state (P = .001) at 30 minutes. No effect, however, was seen at 24 hours. With iotrolan, no significant reduction in chemotaxis was seen at 30 minutes or at 24 hours. CONCLUSIONS: Radiographic contrast media have differing effects on leukocyte chemotaxis. This may be of significance in the selection of appropriate RCM in certain patients.
Cryoprostatectomy, the use of subzero temperatures to ablate prostate tissue gained favour in the 1960s because of its speed and lack of haemodynamic effects. It fell from use because the freezing process could not be monitored and this led to a high incidence of local complications. We have performed transrectal real time ultrasound in 12 patients undergoing cryoprostatectomy. In all the freezing process was easily visualized as an advancing hyperechoic 'iceball' with distal acoustic shadowing. Monitoring allowed maximum prostate ablation without breaching the prostatic capsule. There were no significant complications and all but one patient gained symptomatic relief. Ultrasound at 1 month showed a heterogeneous echo pattern with very little cavity formation but by 3 months a significant cavity was seen. This study demonstrates that it is possible to monitor the freezing process during transurethral cryoprostatectomy. This, theoretically, should significantly reduce the local complications encountered in previous studies.
The effects of radiographic contrast media (RCM) on leucocyte orientation in vitro were studied using a Zigmond chamber. Leucocyte orientation was assessed following exposure of the leucocytes to iotrolan, iohexol, ioxaglate and diatrizoate. The RCM used were diluted to a concentration similar to that obtained in vivo during routine angiography. At this concentration there was a significant reduction in leucocyte orientation for all RCM investigated but the effect was more pronounced in the monomeric than the dimeric RCM. The results may have significance when deciding which radiographic contrast medium to use in selected patients, particularly those who are immunosuppressed or septicaemic.
OBJECTIVE: The purpose of this study was to assess the frequency of significant disease (i.e., occlusion or stenosis > 70%) of the celiac and superior mesenteric arteries in asymptomatic patients. SUBJECTS AND METHODS: Using duplex sonographic criteria obtained from previous angiographic-duplex Doppler correlation studies, we assessed the frequency of significant disease in the celiac and superior mesenteric arteries in 184 patients who had no signs or symptoms of mesenteric ischemia. RESULTS: For patients less than 65 years old, the frequency of significant disease was 3%, and it was isolated to the celiac artery. Significant disease was found in 18% of patients more than 65 years old (in 11%, isolated to one vessel; in 7%, disease of both vessels). Single-vessel disease was more common in the celiac artery (81%) than in the superior mesenteric artery (19%). CONCLUSION: These results indicate that the finding of significant abnormality of the celiac and superior mesenteric arteries on Doppler sonograms does not necessarily indicate mesenteric ischemia.
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The migration of recirculating B cells was compared with that of newly produced virgin B cells following passive cell transfer between congenic strains of rats differing in their kappa immunoglobulin light chain (kappa) allotype. The number and location of donor B cells in the secondary lymphoid organs was determined at intervals following transfer by immunohistology using monoclonal antibodies specific for rat kappa allotypes. Recirculating B cells were obtained from thoracic duct lymph while bone marrow from rats depleted of recirculating cells was used as a source of newly produced virgin B cells. B cells from both sources gained immediate access to extrafollicular areas of secondary lymphoid organs rich in interdigitating cells and T cells. However, in lymph nodes extrafollicular B cells were found adjacent to lymphatics and not in the central paracortex. By 8 h after transfer most B cells from thoracic duct lymph were found in follicles. However, the capacity of the bone marrow B cells to enter follicles was very limited. These results are interpreted in relation to previous observations concerning (a) the timing of virgin B cell recruitment into T cell-dependent antibody responses, and (b) the role of B cells in antigen presentation.
The impact of therapeutic interventions on the disease process in patients with rheumatoid arthritis (RA) is complex. The effect on the acute phase response was studied in 25 in-patients on imposed bed rest, who were randomised to treatment with (n = 12) or without (n = 13) intra-articular steroids. C-reactive protein (CRP), ESR and IgA alpha-1 antitrypsin complex levels were measured on admission and on days 3 and 5. Levels at onset were not different between groups. At day 3 and day 5, a significant (p < 0.001) fall in CRP was seen only in the intra-articular steroid group. Other cytokine and disease parameter measures did not alter during the study period (although IL-6 and CRP correlated at onset in all 25 patients). The mean duration of the hospital stay was longer for the patients treated with bed rest only. Thus, bed rest when combined with intra-articular steroids produced a rapid systemic effect, while bed-rest alone did not have an effect on the acute phase response over this short time scale.