Is the VBR still a useful measure of changes in the cerebral ventricles?

Standard methods of ventricular measurement with computed tomography (CT) and magnetic resonance imaging (MRI) allow for as much as a 10-mm variation in the level of the "best" axial slice through the lateral ventricles. In a series of 10 patients who received MRI scans, the effect of 1-mm variations in slice center level on measured ventricle-brain ratio (VBR) was determined; even variations as small as 1 mm can result in a 10% change in VBR. The amount of within-subject variability in VBR that could result from this factor alone appears to be more than twice as large as that encountered with direct volume measurements, indicating that the latter measure would be at least twice as sensitive to real changes in ventricular size as the VBR.     

Secondary hyperparathyroidism and osteopenia in women following gastric exclusion surgery for obesity

Gastric exclusion has been introduced as a surgical treatment for morbid obesity. We describe two women who had undergone gastric bypass for obesity with metabolic bone disease and secondaryhyperparathyroidism. In one patient transiliac bone biopsy after double tetracycline labelling demonstrated histologic evidence of hyperparathyroidism with osteitis fibrosa cystica. Six additional women who had undergone gastric exclusion were evaluated. Serum phosphorus, calcium, and creatinine were normal in all but one patient who had hypocalcemia. Serum immunoreactive parathyroid hormone was elevated in seven of eight patients and urinary calcium was 2 mmol/d (80 mg/24 h) in 6 patients. Lumbar spine bone mineral density was 86±7 (mean±SE) per cent of predicted and femoral neck bone mineral density was 89±6 per cent of predicted. Women who have had gastric exclusion for obesity may develop secondary hyperparathyroidism which could result in loss of bone mass.Deceased     

A modified prognostic index based upon nutritional measurements

This paper describes a formula which, on solution, derives a prognostic index (PI) for predicting surgical complications using an anthropometric measurement and serum protein levels which may be obtained easily and rapidly. The formula was applied to three groups of patients, firstly 106 patients undergoing major surgical resection, secondly to 16 patients admitted for minor surgery to assess a normal range, and thirdly 10 patients undergoing total parenteral nutrition. In patients undergoing major surgical resection the prognostic index was significantly greater in those patients developing complications than in the control group and a good predictor of the risk of complications. The index uses nutritional measurements to predict complications rather than being a measurement of nutritional status and is therefore a poor monitor of the efficacy of nutritional therapy.     

Exercise responses of healthy subjects in the evaluation of cardioselectivity ofβ-blockers

Summary The effects of intravenous propranolol, metoprolol, acebutolol and placebo on exercise-induced changes in heart rate and peak flow rate (PFR) have been studied in a group of healthy subjects. The three -blockers produced significant and comparable reductions in exercise-induced tachycardia and the magnitude of the reduction was related to the log plasma concentration of each drug. Significant cardiac -blockade was detectable for three hours after giving propranolol and for four hours after metoprolol and acebutolol. The exercise-induced changes in PFR were small and variable and were not significantly affected by any of the drugs. We conclude that, contrary to published reports, exercise-induced changes in heart rate and PFR in healthy subjects do not provide a satisfactory test system for assessing the selectivity of -blockers.     

Mathematical/computational challenges in creating deformable and probabilistic atlases of the human brain

Striking variations in brain structure, especially in the gyral patterns of the human cortex, present fundamental challenges in human brain mapping. Probabilistic brain atlases, which encode information on structural and functional variability in large human populations, are powerful research tools with broad applications. Knowledge-based imaging algorithms can also leverage atlased information on anatomic variation. Applications include automated image labeling, pathology detection in individuals or groups, and investigating how regional anatomy is altered in disease, and with age, gender, handedness and other clinical or genetic factors. In this report, we illustrate some of the mathematical challenges involved in constructing population-based brain atlases. A disease-specific atlas is constructed to represent the human brain in Alzheimer's disease (AD). Specialized strategies are developed for population-based averaging of anatomy. Sets of high-dimensional elastic mappings, based on the principles of continuum mechanics, reconfigure the anatomy of a large number of subjects in an anatomic image database. These mappings generate a local encoding of anatomic variability and are used to create a crisp anatomical image template with highly resolved structures in their mean spatial location. Specialized approaches are also developed to average cortical topography. Since cortical patterns are altered in a variety of diseases, gyral pattern matching is used to encode the magnitude and principal directions of local cortical variation. In the resulting cortical templates, subtle features emerge. Regional asymmetries appear that are not apparent in individual anatomies. Population-based maps of cortical variation reveal a mosaic of variability patterns that segregate sharply according to functional specialization and cytoarchitectonic boundaries.     

Perioperative optimisation of fluid management improves outcome

Mortality from high-risk surgery is close to 10% (20% with emergency). Poor outcome is linked to tissue hypoperfusion. Optimising fluid therapy has a good pathophysiological basis related to microvascular flow to the tissues and the risk of multiple organ failure. Metaanalysis showed the higher the risk of surgery the greater the benefit of fluid and flow optimisation. A direct technique (blood pressure is indirect) to manage fluid therapy measuring tissues perfusions has not yet fulfilled criteria (easiness, accuracy, less invasiveness). At present pulmonary artery catheter with continuous output measurement is the choice. The aim of the study is to assess the impact of fluid management to increase blood flow in high-risk surgical patient.     

Role of n-3 fatty acids in prevention of disease complications in patients with HIV.

Hypertriglyceridemia and insulin resistance have been seen in patients with HIV. Beneficial effects of the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been reported for these conditions. One study of n-3 fatty acid supplementation in patients with HIV reported a decrease in serum triglyceride levels. These marine fatty acids appear to be working at a number of sites to achieve an improvement in lipid metabolism and insulin sensitivity. There is disagreement about the amount of n-3 fatty acids needed to achieve different effects and about the optimal ratio of dietary n-6 and n-3 fatty acids.     

A UK multi‐centre pilot study of speech and swallowing outcomes following head and neck cancer

Speech and swallowing are important components of health‐related quality of life following head and neck cancer treatment. The aim of this study was to demonstrate the value of prospective multi‐centre evaluation by Speech and Language Therapists and to compare health‐related quality of life with speech and swallowing impairments. The University of Washington Head and Neck questionnaire version 4 (UW‐QOL) and Therapy Outcome Measures (TOM) were rated before and 6 months after cancer treatment in 95 patients from 12 centres. There was deterioration in TOM scores at 6 months. Pretreatment UW‐QOL swallowing was ranked equal first, with speech fourth. At 6 months speech was first and swallowing second. There were positive correlations between UW‐QOL swallowing and TOM dysphagia and between UW‐QOL speech and TOM laryngectomy, voice, phonology and dysarthria disorders. Both outcome measures are suitable for routine practice. Adaptation of TOM scales for use with head and neck cancer patients may improve sensitivity, validity and therapist compliance.