Abdominal aortic aneurysm repair and colonic infarction: a risk factor appraisal

OBJECTIVE: Colonic infarction is a recognized complication of abdominal aortic aneurysm (AAA) surgery. The clinical difficulty in establishing the diagnosis combined with the patient's poor physiological status is usually associated with a fatal outcome. We assessed our experience with this problem to identify a possible risk factor profile for these patients. METHOD: Patients records were identified from the operative logs, intensive care unit, Hospital Inpatient Enquiry system and vascular unit databases over a 6-year period. RESULTS: A total of 405 patients underwent AAA repair during this period; 140 as emergency ruptures. Nine patients were identified from the databases with known colonic infarction (2.2%). One was a woman. The mean age was 70 years. Seven patients had emergency ruptures (5%). Twenty independent risk factors were analysed using univariate and multivariate logistic regression models. Significant risk factors identified by using a multivariate analysis included the nature of the presenting patient, preoperative hypotension, prolonged cross-clamp time, intra-operative ischaemia and postoperative acidosis. Confirmatory diagnosis was made by colonoscopy in eight patients. One patient survived following the salvage surgery. The mean duration of survival was 10.5 days. The overall mortality was 89% of patients. CONCLUSION: In our unit infrarenal AAA repair has a 2.2% rate of colonic infarction. A definitive diagnosis is best made by colonoscopy. A risk factor profile for the development of colonic infarction may be constructed on the basis of specific clinical parameters. Earlier intervention on the basis of this profile may ultimately reduce the current excessive mortality.     

Recombinant GH replacement in hypopituitary adults improves endothelial cell function and reduces calculated absolute and relative coronary risk

OBJECTIVE: Adult GH deficiency (GHD) is linked to endothelial dysfunction and vascular disease. We examined the effect of 12 months of GH therapy on endothelial function, C-reactive protein (CRP) and coronary risk. DESIGN: Open-design intervention study. PATIENTS: Fourteen GH-deficient patients (nonsmokers, without diabetes, hypertension or vascular disease) studied before, 6 months and 12 months after GH therapy. MEASUREMENTS: Flow-mediated dilatation (FMD), carotid intima-media thickness (IMT) thrombomodulin (TM), E-selectin, CRP, lipid profile, blood pressure and anthropometric data were recorded. We used the Framingham equation to calculate coronary risk. RESULTS: FMD improved (7.5 +/- 1.62 vs. 11.93 +/- 1.52, P = 0.038). Overall there was no change in IMT, TM, E-selectin or CRP. The correlation between TM and FMD showed a trend for statistical significance (r = -0.54, P = 0.056). Changes in CRP correlated with change in IGF-1 (r = -0.67, P = 0.012); E-selectin correlated with high density lipoprotein (HDL)-cholesterol (r = -0.60, P = 0.028), triglycerides (r = 0.68, P = 0.01) and waist-to-hip ratio (WHR) (r = 0.71, P = 0.006). Systolic (127.36 +/- 4.47 vs. 120.36 +/- 3.50, P = 0.017) and diastolic (84.71 +/- 2.73 vs. 76.93 +/- 2.03, P = 0.005) blood pressure decreased. HDL-cholesterol increased (0.70 +/- 0.05 vs. 0.93 +/- 0.06, P = 0.001). WHR decreased (0.90 +/- 0.02 to 0.88 +/- 0.02, P = 0.043) without changes in weight or body mass index (BMI). Ten-year absolute (P = 0.009) and relative (P = 0.002) cardiac risk decreased. CONCLUSION: Biophysical test of endothelial function (FMD) improved after 12 months of GH therapy but there was no significant change in biochemical endothelial or inflammatory markers. Calculated coronary risk decreased mainly due to reduction in systolic and diastolic blood pressure and increase in HDL-cholesterol.     

Semantic-Episodic Memory Interactions in Semantic Dementia: Implications for Retrograde Memory Function

Semantic dementia refers to a multi-modal loss of semantic knowledge, resulting from degeneration of the anterior temporal neocortex. Loss of information is not absolute. We have previously demonstrated (Snowden, Griffiths,& Neary, 1994, 1995) that autobiographical experience has an important role in influencing information preservation, and have argued that patients' preserved experiential memory helps to invest words and objects with meaning that would otherwise be lost. Those studies suggested a particularly critical role of current autobiographical experience. The present study aimed to explore the generality of the observed current information superiority in an investigation of patients' knowledge of celebrities, understanding of a contemporary and obsolete monetary system, and autobiographical memory. Performance was superior for contemporary (recent) than for past (remote) information, both factual and autobiographic, suggesting an inverse of the temporally graded pattern of retrograde memory found in classical amnesia. It is argued that the findings are consistent with explanations of the "temporal gradient" effect of retrograde amnesia in terms of qualitative differences in recent and remote memories. The findings indicate a bidirectional interaction between autobiographic and semantic memorising, and emphasise a continuous, dynamic interrelationship rather than a time-limited role. An important distinction is highlighted between autobiographical and impersonal episodic memory. The findings have significant theoretical implications both for the understanding of retrograde memory function and the interrelationship between episodic and semantic memory.     

Treatments,complications, and healthcare utilization associated with acromegaly: a study in two large United States databases

Pituitary - The economic burden of acromegaly in the US has been largely unknown. We describe the prevalence of treatment patterns, complication rates, and associated healthcare utilization and...     

Mitochondrial function in brain tissue in primary degenerative dementia

Previous in vitro and in vivo studies of the brain in Alzheimer's disease indicated alterations in metabolism related to energy production although the relationships between these changes remains obscure. To help resolve this issue, in vitro oxygen uptake by homogenates of fresh samples of frontal neocortex from patients with dementia and neurosurgical controls has been examined as a measure of energy-related metabolism and mitochondrial function. Maximal respiratory rates (measured in the presence of an uncoupling agent) were similar for samples from 7 controls, 5 patients with Alzheimer's disease and two patients diagnosed clinically as Pick's disease, suggesting that there was little or no effect of these dementias on the maximal metabolic capacity of the tissue. However, under some conditions producing sub-maximal metabolic activity (which are of potentially greater physiological relevance) oxygen uptake rates were significantly elevated in the dementia group. The ratio of oxygen uptake rates in the presence and absence of ADP was significantly reduced (to 58% of control; P less than 0.02) for the dementia patients compared with controls, possibly indicative of partial mitochondrial uncoupling. These results indicate metabolic changes expressed in vitro which may be relevant to the pathogenesis of Alzheimer's disease and some related dementias.     

Evaluation of the NINCDS-ADRDA criteria in the differentiation of Alzheimer's disease and frontotemporal dementia

OBJECTIVES: The diagnosis of Alzheimer's disease (AD) is now reliant on the use of NINCDS-ADRDA criteria. Other diseases causing dementia are being increasingly recognised--for example, frontotemporal dementia (FTD). Historically, these disorders have not been clearly demarcated from AD. This study assesses the capability of the NINCDS-ADRDA criteria to accurately distinguish AD from FTD in a series of pathologically proved cases. METHODS: The case records of 56 patients (30 with AD, 26 with FTD) who had undergone neuropsychological evaluation, brain imaging, and ultimately postmortem, were assessed in terms of whether at initial diagnosis the NINCDS-ADRDA criteria were successful in diagnosing those patients who had AD and excluding those who did not. RESULTS: (1) The overall sensitivity of the NINCDS-ADRDA criteria in diagnosing "probable" AD from 56 patients with cortical dementia (AD and FTD) was 0.93. However, the specificity was only 0.23; most patients with FTD also fulfilled NINCDS-ADRDA criteria for AD. (2) Cognitive deficits in the realms of orientation and praxis significantly increased the odds of a patient having AD compared with FTD, whereas deficits in problem solving significantly decreased the odds. Neuropsychological impairments in the domains of attention, language, perception, and memory as defined in the NINCDS-ADRDA statement did not contribute to the clinical differentiation of AD and FTD. CONCLUSION: NINCDS-ADRDA criteria fail accurately to differentiate AD from FTD. Suggestions to improve the diagnostic specificity of the current criteria are made.