Exercise training for claudication.

Exercise advice is a well established component of the conservative management of intermittent claudication. Supervised programmes of exercise remain relatively uncommon and are provided mainly in secondary care. This review outlines the evidence for the effectiveness of different exercise regimens and the relative benefits of exercise therapy, where comparisons have been made with medical therapy, angioplasty and surgery.     

Relationship between methaemoglobin production and methylene blue plasma concentrations under general anaesthesia

Recently, a family tree with a predisposition for the gene of multiple endocrine neoplasia Type 1 has been identified in Tasmania. As the surgical identification and localisation of parathyroid adenomas is facilitated by the administration of methylene blue, an opportunity has presented to measure the plasma concentration of methylene blue and methaemoglobin production. The study was undertaken to establish whether significant methaemoglobin concentrations were generated during the infusion and whether these concentrations could be related to the corresponding methylene blue concentrations. Mean peak methylene blue concentrations of 3.72 micrograms l-1, mean percentage methaemoglobin of 10.0 and a PaO2 within acceptable clinical ranges were found. No apparent relationship between methylene blue concentration and methaemoglobin production was found.     

Intestinal ischaemia in the unconscious intensive care unit patient.

This paper highlights the difficulties of diagnosing intestinal ischaemia in unconscious patients on an intensive care unit. We have analysed the clinical details and investigations of eight such patients in whom a preoperative diagnosis of intestinal ischaemia was made on clinical grounds. Intestinal ischaemia was confirmed at laparotomy in only four cases (50%). These patients showed no significant differences in any of the commonly accepted parameters of intestinal ischaemia from the four patients who had a negative laparotomy. In particular, all patients exhibited a metabolic acidosis with fever and a leucocytosis. There was a mean delay of 13.6 h between surgical opinion and laparotomy in the four patients with ischaemia, only one of whom was salvaged. There was no morbidity associated with the laparotomy in this small series. It is suggested that, in the intensive care setting, early laparotomy should be performed immediately the clinical suspicion of intestinal ischaemia arises.     

Preliminary experience of angioscopy in femorodistal bypass.

During femorodistal bypass angioscopy can be used in vein graft preparation allowing valve lysis and the identification of tributaries under direct vision. A total of 30 patients have undergone angioscopic assisted femorodistal bypass using either an Olympus or Stortz system. Nineteen patients have undergone full vein mobilisation and valve lysis under direct vision. Eleven patients had in situ bypass with ligation of tributaries, identified by the angioscope, through small stab incisions. No evidence of fistula or retained valve cusps was found by subsequent duplex scanning and arteriography. One of these grafts failed at 6 days due to an unrecognised outflow stenosis. The mean hospital stay after operation for this latter group of patients was 5.2 days (range 4.4-6.0 days) compared with 9.5 days (8.6-10.3 days) in a historical group of 30 patients (P < 0.001). Angioscopy is a useful aid in the performance of femorodistal bypass. Early experience suggests that hospital stay may be reduced by angioscope assisted in situ femorodistal bypass because of the minimal dissection involved.     

Right atrial myxoma mistaken for recurrent pulmonary thromboembolism

A 69 year old man was admitted for investigation of right sided pleuritic chest pain and dyspnoea, both of which began suddenly four days before admission. Acute pulmonary embolism was diagnosed. Six months after discharge while on warfarin he died. Necropsy found a 50 mm diameter myxoid tumour arising on the right atrial side of the interatrial septum. This lesion may have been discovered earlier by echocardiography although there were no clear indications for this investigation. Presentation was that of recurrent pulmonary embolism with no obvious source or cause of thrombosis. Patients who are thought to have idiopathic pulmonary embolism should undergo early echocardiography to exclude the rare but treatable diseases of the right heart that may be responsible

Keywords: atrial myxoma     

Everyday memory following traumatic brain injury

Residual memory deficits may represent a problem to the everyday functioning of a large number of people, including those who have sustained traumatic brain injury (TBI). The present exploratory study sought to investigate the interrelationships between subjective memory reports, performance on traditional memory tests, and performance on tests of prospective memory. These interrelationships were contrasted between a group of 24 adults who had sustained TBI and a group of 24 matched control subjects. Prospective memory was hypothesized to be indicative of everyday memory functioning. The results provided preliminary evidence that prospective memory tests are sensitive to TBIrelated neurological impairment and, in comparison to traditional tests, may be better indicators of functional memory capacity. This pattern was particularly true for control subjects, possibly because TBI subjects had difficulties in evaluating their memory functioning.     

A specific and sensitive radioimmunoassay for rat C-peptide

A sensitive and specific radioimmunoassay for rat serum C-peptide (RCP) has been developed and validated using a guinea pig anti-rat C-peptide antibody to synthetic rat C-peptide. Negligible crossreactivity (<0.01%) to human proinsulin was observed, whereas human insulin, human pancreatic polypeptide (hPP), porcine insulin, porcine C-peptide, bovine insulin, rat insulin, porcine-PP, and glucagon, respectively, did not produce measurable displacement of RCP tracer. Human C-peptide even in a supraphysiological concentration range crossreacted poorly (<0.1%). The sensitivity limit of the assay calculated at ±3 standard deviations was 24.2pM (0.07 ng/mL). RCP standard concentrations ranged from 25–1600pM. The intraassay-and between assay-coefficient of variations (CV) were 3.5–6.1% and 4.1–9.5%, respectively. The mean percentage recovery of RCP added to rat serum samples was 100.8±2%. Serum volume dilution from 25 to 100 μL did not significantly alter the expected RCP level. Migration of rat serum C-peptide and that of synthetic RCP were identical in a Sephadex G-50 chromatographic analysis. The mean fasting and postprandial plasma RCP levels in normal rats were 102±15pM and 485±75pM, respectively. RCP levels following intravenous glucose tolerance test in diabetic and nondiabetic rats were consistent with expected patterns. In conclusion, we have developed and validated a rat C-peptide assay that is sensitive, simple, and specific for RCP in serum. The assay provides a reliable tool for studies of diabetes using rodent animal models.