De novo generation of histamine in sputum and the effect of antibiotics

We have performed experiments to test the hypothesis that bacteria may contribute to the presence of histamine in sputum. Sputum samples obtained from 7 patients with exacerbations of chronic bronchitis and 7 patients with cystic fibrosis were incubated at 37 degrees C for 72 hours. Serial sputum histamine estimations, performed by a recently-developed HPLC technique, showed large, progressive increases in both groups of samples. Both the pre-heating of samples at 100 degrees C prior to incubation and the addition of antibiotics to the incubates substantially reduced these increases. These findings strongly suggest that bacteria may contribute to sputum histamine in infective lung disease.     

Urinary output of endogenous monoamine oxidase inhibitor and isatin during acute migraine attacks

Summary Urinary output of endogenous monoamine oxidase (MAO) inhibitory activity, was significantly raised in serial samples collected across a migraine attack compared with collections during attack-free periods and in healthy controls, which did not differ from each other. There was a highly significant correlation in output between isatin, a major fraction of the MAO inhibitory activity, and output of the MAO inhibitory activity itself. However, although there was a tendency towards increased isatin excretion during migraine attacks, it failed to reach statistical significance.     

Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance

Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy.     

Sensitisation to Swine Leukocyte Antigens in Patients with Broadly Reactive HLA Specific Antibodies

We have previously shown that IgG HLA specific antibodies in the sera of highly sensitised patients awaiting renal transplantation can cross-react with swine leukocyte antigens (SLA). In this study we determined the frequency of patient serum IgG HLA specific antibody binding to a porcine lymphocyte panel and the likelihood of locating a cross-match negative pig donor for sensitised patients. Serum samples (n = 82) were obtained from 35 sensitised [current IgG panel reactive antibodies (PRA) > 10%] and seven nonsensitised patients awaiting renal transplantation at Addenbrooke's Hospital, Cambridge, UK. Fifty sera had IgG HLA specific PRA of 11-84%, 20 had IgG PRA of >84% and 12 had 0% PRA (negative controls). Sera were absorbed with porcine erythrocytes to remove xenoreactive natural antibodies and tested for cross-reactive IgG HLA specific antibody binding by flow cytometry against a panel of porcine lymphocytes obtained from 23 human decay accelerating factor (hDAF) transgenic pigs. A total of 1,884 cross-match combinations were tested and 369 (20%) gave a positive porcine lymphocyte cross-match. For sera from sensitised patients with IgG PRA (11-64%), only 6 of 805 (0.75%) cross-match tests were positive. In contrast, for sera from patients with high IgG PRA (>64%), 363 of 805 (45%) cross-match tests were positive (p < 0.0001). There was no difference in the frequency of positive cross-matches between patient sera with IgG PRA 65-84% and highly sensitised patient sera with IgG PRA 85-100% [156/345 (45%) vs. 207/460 (45%)]. This study demonstrates that only patient sera with broadly reactive IgG HLA specific PRA (>64%) cross-react with porcine lymphocytes. If future clinical trials of xenotransplantation are undertaken, it may be of value to select a cross-match-negative pig organ donor for such patients.     

Development and implementation of an innovative intern training programme

The quality of medical education during internship is a cause for concern. This paper describes a structured educational programme for interns that was based around learning modules, clinical attachments and bedside teaching. The programme was incorporated into the term rotation of interns within an Area Health Service, and evaluated. Learning modules were timetabled by a Programme Coordinator and interns were reminded to attend. Clinical attachments were organized by the interns from a list of willing supervisors. Attendance at timetabled learning modules averaged 67%, which was greater than the 27% attendance at clinical attachments. Both sessions received high ratings for quality and clinical relevance. This structured education programme was based upon adult learning methods and was both feasible and well received by interns. Intern training programmes need to be programmed into the working week to ensure attendance, and modified following evaluation by interns. Such programmes should be considered by all hospitals to which interns are allocated.     

Intractable leg ulceration caused by cutaneous cholesterol embolism.

OBJECTIVE: To present a case of chronic intractable leg ulceration caused by cholesterol crystal embolism. CLINICAL FEATURES: A 76-year-old Caucasian male with a history of ischaemic heart disease had repeated hospital admissions for diagnosis and treatment of recurrent leg ulceration of more than three years' duration. INTERVENTION AND OUTCOME: Definitive diagnosis was made after the third biopsy when the specimen obtained included subcutaneous arteries. Complete healing occurred within three weeks of excision and a skin graft, and subsequent treatment which included systemic steroids. CONCLUSION: Cholesterol crystal embolism is probably an underdiagnosed cause of intractable leg ulceration and can be identified by a biopsy specimen which includes vessels in subcutaneous fat. Systemic steroids may be helpful in its treatment.     

Recovery from infectious mononucleosis after altitude training in an elite middle distance runner.

OBJECTIVES: This investigation was designed to monitor altitude acclimatisation in an elite cohort of distance runners and follow the subsequent recovery from infectious mononucleosis which developed in one of these athletes. METHODS: Twenty six national standard distance runners performed treadmill tests 24 days before they travelled to an altitude camp (1500 to 2000 m). One of these athletes was diagnosed as suffering from infectious mononucleosis 14 days after return to sea level. A physician prescribed an individualised training programme which was designed to maximise recovery from the condition, which was monitored on days 16 and 147 after altitude training. RESULTS AND CONCLUSIONS: The data suggest that the athlete was in a state of over-reaching during the altitude sojourn. After return to sea level, the early stages of infectious mononucleosis resulted in a marked impairment in physiological response to endurance exercise, which improved over time. Longitudinal physiological monitoring in conjunction with a carefully prescribed training programme made recovery from this condition possible.     

Glomerular epithelial cell endocytosis in puromycin-induced glomerulopathy.

Glomerulopathy and nephrotic syndrome were induced in rats by intravenous puromycin aminonucleoside. Ten days after the injection of puromycin, the animals have developed heavy proteinuria. During this phase, glomerular epithelial cell endocytosis was studied by injecting a conjugate of horseradish peroxidase and poly-L-lysine. This conjugate has been shown to be endocytosed by glomerular epithelial cells. The rats were serially sacrificed from 1 min to 24 h after this injection. Peroxidase was localised cytochemically and observed at light and electron microscopy. The early events of endocytosis in glomerulopathy (namely the binding to the plasma membrane, the membrane invagination and the formation of the early vesicles) were qualitatively similar to those in the normal. The later events (the fusion of the vesicles and their movement within the cells) were inhibited. The results show that puromycin aminonucleoside damages epithelial cell endocytotic activity and affects the later processing of the conjugate within the cells.