Resting energy expenditure and nutritional state of patients with increased oxygen cost of breathing due to emphysema, scoliosis and thoracoplasty.

BACKGROUND--Weight loss is a well recognised feature of patients with emphysematous chronic obstructive pulmonary disease (COPD). It has been suggested that this weight loss could be due to a hypermetabolic state resulting from the increased oxygen cost of breathing (OCB). To clarify the relation between resting energy expenditure (REE), nutritional state, and OCB these indices were measured in patients with respiratory impairment and an increased OCB due to COPD, scoliosis, and thoracoplasty. METHODS--Eighteen patients (six COPD, six scoliosis, six thoracoplasty) of mean (SD) age 59.9 (8.6) years (8M, 10F) and six controls (45.5 (9.9) years; 2M, 4F) were studied. OCB was estimated by the addition of dead space to the breathing circuit and REE was measured by indirect calorimetry using a ventilated canopy system. Height, arm span, weight, triceps skin fold thickness (TSF), mid-arm muscle circumference (MAMC), forced expiratory volume in one second (FEV1), and vital capacity (VC) were measured in all study subjects. RESULTS--OCB was elevated in all patient groups (mean 7.0 ml/l) compared with controls (1.9 ml/l). All patients with COPD, four with scoliosis, three with thoracoplasty, and none of the controls were < 90% ideal body weight. Mean (SD) measured REE as % predicted (Harris-Benedict equation) was 103.8 (7.6) in patients with COPD, 105.5 (10.9) in those with scoliosis, 106.3 (6.9) in the thoracoplasty patients, and 103.3 (3.4) in controls. One patient with COPD, two with scoliosis, two with thoracoplasty, but no controls were hypermetabolic (REE > 110% predicted). In all groups there was a negative relation between OCB and lung function (OCB v FEV1 r = -0.83 in COPD, -0.62 in scoliosis, -0.67 in thoracoplasty, and -0.76 in controls). There was no correlation between REE and OCB or MAMC. CONCLUSIONS--In patients with respiratory disease OCB (augmented ventilation) is related to lung function but not to REE. This is evidence against the hypothesis that hypermetabolism due to increased oxygen cost of breathing at rest is the sole or major cause of malnutrition in patients with lung disease.     

The effects of cardiopulmonary bypass and cold cardioplegia on coronary flow velocity and the reactive hyperemic response in patients and dogs

In normal coronary arteries, reactive hyperemic responses to a 20-second occlusion, an index of coronary reserve, usually demonstrate a peak-to-resting flow velocity ratio of 4:1 or more. Most intraoperative studies that have assessed reactive hyperemic responses in bypassed vessels have reported peak-to-resting flow velocity ratios of 2:1 or less following a 20-second occlusion. These decreased reactive hyperemic responses could be due to coronary vasodilatation after cardiopulmonary bypass or to an inadequate physiological result of the surgical procedure. In 14 patients with angiographically normal coronary arteries, the peak-to-resting flow velocity ratio following a 20-second coronary occlusion decreased significantly (p less than 0.05) from 4.4 +/- 0.2 (mean +/- standard error) before bypass to 3.0 +/- 0.3 after bypass. In a similar dog model, the peak-to-resting flow velocity ratio decreased by 36 to 52% during the first hour following one hour of cardiopulmonary bypass and cardioplegia. During the same period, left ventricular perfusion increased 21 to 30%, mean arterial pressure and coronary vascular resistance decreased, and myocardial oxygen consumption was unchanged. In a second group of dogs studied for the effects of duration (200 to 240 minutes) of anesthesia and thoracotomy alone, peak-to-resting flow velocity ratio was significantly lower. These clinical and experimental studies suggest that major coronary vasodilatation occurs early following cardiopulmonary bypass and cold cardioplegia, and may contribute to the blunted coronary reactive hyperemic responses reported during this time. Consequently, an intraoperative peak-to-resting flow velocity ratio of 3:1 for bypassed coronary arteries may represent an excellent physiological result.     

Stress analyses of glenoid component designs

Metal backing of glenoid components for total shoulder replacements and the use of bony ingrowth surfaces on these components have recently been introduced. In this study, finite element analyses were performed to determine the stress fields in the natural glenoid and to calculate the change in bone stresses after implantation of glenoid components of various designs. The effects of metal backing, keel geometry, and superior constraint on bone stresses indicate that stress distributions on the natural glenoid corresponded to bone morphology. Metal-backing the glenoid component may cause slight improvement in stress transfer to cortical bone. Altered fin geometry better stabilized the glenoid component. Superior restraints on the component intending to prevent subluxation increase stresses and may cause earlier loosening than encountered with unconstrained components.     

Germline mutations in the neurofibromatosis type 2 tumour suppressor gene

The recent identification of the NF2 tumour suppressor genehas enabled large scale screening for pathological mutationsin the gene. We have sought germline mutations In the NF2 geneby SSCP and heteroduplex analysis of cDNA and genomic DNA samplesfollowed by cloning and sequencing of mutant alleles. In thepresent report we describe 11 putative pathological mutations,including five nonsense mutations, three short insertions ordeletions cauing frameshifts and three missense mutations. Moststop mutations and frameshift mutations were found In Individualsexpressing a severe phenotype while one of the three missensemutations was associated with a mild phenotype. Four unrelatedNF2 patients of the 93 tested were found to have identical nonsensemutations caused by a C to T transition (C169) in a CpG dinucleotide,which is a potential mutational hotspot in the NF2 tumour suppressorgene.     

Aggressive angiomyxoma with gastrointestinal communication: a case report

We report the imaging findings of an abdominal aggressive angiomyxoma, which communicated with the gastrointestinal tract. The literature on this rare tumor is reviewed.     

Stress injury of the distal radial growth plate

We report 21 cases of stress injury of the distal radial growth plate-occurring in gymnasts before skeletal maturity. The injury appears to be caused by inability of the growth plate to withstand rotational and compressive forces. Our observations have confirmed that the skeletal age of gymnasts is retarded, which increases the length of time during which the epiphysis is at risk of damage.     

Are current processes for nuclear emergency management in Europe adequate?

We describe the results of process mapping of nuclear emergency management procedures in four European countries. We find clear differences and explore these in relation to their suitability for building a shared understanding across the emergency management team of the evolving situation and a balanced appreciation of the uncertainties. Our findings indicate that there are some issues that cause concern in that the procedures may run smoothly and efficiently but they may also risk underestimating uncertainty or ignore key issues that have only been identified by a minority of experts or models. We are concerned that they do not facilitate the building of shared mental models that the literature such as that on highly reliable organisations has shown is important.