Communicating oesophageal duplication

Oesophageal duplications are rare congenital abnormalities. Most of them do not communicate with the oesophageal lumen. We present a very uncommon finding of communicating oesophageal duplication in which the connection between the oesophagus and its duplicate portion was demonstrated by CT.     

Uptake of individual fatty acids into adipose tissue in relation to their presence in the diet

BACKGROUND: The fatty acid composition of adipose tissue triacylglycerol reflects, but is not identical to, the fatty acid composition of the habitual diet. OBJECTIVE: We investigated whether the fatty acid composition of adipose tissue is explained by differences between fatty acids in early storage in adipose tissue after a meal. DESIGN: Nine healthy men ate a meal containing several fatty acids. Blood samples were taken for 6 h after the meal from an arterialized hand vein and a vein draining the anterior abdominal subcutaneous adipose tissue. RESULTS: Net storage of fatty acids in adipose tissue occurred between 1 and 4 h after the meal. In relation to the amount fed, storage of fatty acids differed (P < 0. 01) between classes (n-3 polyunsaturated < saturated < n-6 polyunsaturated < monounsaturated); oleic acid was stored in the greatest amounts. These differences agreed closely with published data, except for n-3 polyunsaturated fatty acids. The only individual metabolic step at which significant differences between fatty acids was shown was incorporation of fatty acids into chylomicron triacylglycerol. Differences between fatty acids in rate of extraction from chylomicron triacylglycerol and net uptake into adipose tissue in the postprandial period were significant (P < 0. 01), but not when expressed in relation to proportions in chylomicron triacylglycerol. CONCLUSIONS: The characteristic fatty acid pattern of adipose tissue may predominantly reflect the early metabolic handling of different fatty acids. Adipose tissue uptake of n-3 polyunsaturated fatty acids is slow in relation to that of other fatty acids.     

Relation between insulin resistance and plasma concentrations of lipid hydroperoxides, carotenoids, and tocopherols

BACKGROUND: It is not known whether total circulating lipid hydroperoxides are increased in insulin-resistant individuals and whether this correlates with depletion of liposoluble antioxidant vitamins that are consumed during lipid peroxidation. OBJECTIVE: The goal of this study was to define the relation between resistance to insulin-mediated glucose disposal and plasma concentrations of lipid hydroperoxides and liposoluble antioxidant vitamins in healthy volunteers. DESIGN: Insulin-mediated glucose disposal was determined in 36 healthy, nondiabetic volunteers by measuring their steady-state plasma insulin (SSPI) and glucose (SSPG) concentrations in response to a 180-min constant infusion of octreotide, insulin, and glucose. In addition, fasting plasma concentrations of lipid hydroperoxides and liposoluble antioxidant vitamins were determined by using the FOX 2 assay and liquid chromatography. RESULTS: Statistically significant direct relations were observed between SSPG and mean arterial blood pressure (r = 0.44, P: = 0.008) and plasma lipid hydroperoxide concentrations (r = 0.42, P: = 0.01), whereas significant inverse correlations were found between SSPG and alpha-carotene (r = -0.58, P: = 0.0002), beta-carotene (r = -0.49, P: = 0.004), lutein (r = -0.35, P: = 0.04), alpha-tocopherol (r = -0. 36, P: = 0.04), and delta-tocopherol (r = -0.45, P: = 0.007). CONCLUSIONS: Variations in insulin-mediated glucose disposal in healthy individuals are significantly related to plasma concentrations of lipid hydroperoxides and liposoluble antioxidant vitamins. These findings suggest that total plasma lipid peroxidation is increased in insulin-resistant individuals at an early, preclinical stage, ie, well before the development of glucose intolerance and type 2 diabetes.     

Assessment of the mutagenicity of dichloroacetic acid in lacI transgenic B6C3F1 mouse liver

Dichloroacetic acid (DCA) is a chlorination byproduct found in finished drinking water. When administered in drinking water this chemical has been shown to produce hepatocellular adenomas and carcinomas in B6C3F1 mice over the animal's lifetime. In this study, we investigated whether mutant frequencies were increased in mouse liver using treatment protocols that yielded significant tumor induction. DCA was administered continuously at either 1.0 or 3.5 g/l in drinking water to male transgenic B6C3F1 mice harboring the bacterial lacI gene. Groups of five or six animals were killed at 4, 10 or 60 weeks and livers removed. At both 4 and 10 weeks of treatment, there was no significant difference in mutant frequency between the treated and control animals at either dose level. At 60 weeks, mice treated with 1.0 g/l DCA showed a 1.3-fold increase in mutant frequency over concurrent controls (P = 0.05). Mice treated with 3.5 g/l DCA for 60 weeks had a 2.3-fold increase in mutant frequency over the concurrent controls (P = 0.002). The mutation spectrum recovered from mice treated with 3.5 g/l DCA for 60 weeks contained G:C-->A:T transitions (32.79%) and G:C-->T:A transversions (21.31%). In contrast, G:C-->A:T transitions comprised 53.19% of the recovered mutants among control animals. Although only 19.15% of mutations among the controls were at T:A sites, 32.79% of the mutations from DCA-treated animals were at T:A sites. This is consistent with the previous observation that the proportion of mutations at T:A sites in codon 61 of the H-ras gene was increased in DCA-induced liver tumors in B6C3F1 mice. The present study demonstrates DCA-associated mutagenicity in the mouse liver under conditions in which DCA produces hepatic tumors.      

Informed consent, parental awareness, and reasons for participating in a randomised controlled study

BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent.     

A CASE SERIES ANALYSIS OF “CATEGORY-SPECIFIC” DEFICITS OF LIVING THINGS:THE HIT ACCOUNT

We report a case series analysis of a group of seven patients with apparent “category-specific” disorders affecting living things. On standard diagnostic tests, a range of deficits were apparent, with some cases appearing to have impaired visual access to stored knowledge, some with impaired semantic knowledge (across modalities), and some with an impairment primarily at a name retrieval stage. Patients with a semantic deficit were impaired for both visual and associative/functional knowledge about living things, whilst patients with a modality-specific access deficit showed worse performance when stored visual knowledge was probed. In addition, patients with impaired access to visual knowledge were affected when perceptual input was degraded by masking, and all patients showed an interaction between perceptual similarity and category when matching pictures to names or defining statements. We discuss the results in terms of the Hierarchical Interactive Theory (HIT) of object recognition and naming (Humphreys & Forde, 2001). We also discuss evidence on lesion sites in relation to research from functional brain imaging on category differences in object identification in normal observers.     

Disorders of Visuo-spatial Cognition

Posterior fusiform gyrus (BA 37) is responsible for Hanja (ideogram) alexia in stroke patients. Patients with semantic dementia (SD) have lesions in the basal temporal area. The close proximity in these two lesions and the fact that reading ideograms requires holistic processing as is necessary in recognition of objects, suggests a possibility that ideogram alexia/agraphia may occur in patients with SD. We established and carried out Hanja and Hangul (phonogram) reading/writing tasks on six SD patients and nine Alzheimer's disease (AD) patients as control to see if these two patient groups show dissociation in the two sets of tests. SPM analysis was performed on the SD patients' PET images to look for any dysfunctions in the posterior fusiform gyrus. The SD patients manifested Hanja alexia/agraphia whereas Hangul reading/writing ability was relatively preserved. There were group differences between SD and AD in the Hanja tasks but not in the Hangul tasks. The SPM analysis revealed no hypometabolism in the posterior fusiform gyrus, but only in the middle and the anterior part of the temporal gyrus. Dysfunction in the middle temporal gyrus (BA 21) may have disrupted the temporal lobe connections preventing the function of the posterior fusiform gyrus.     

Visual selection and action in Balint's syndrome

We examined the relations between attention and action in a patient with Balint's syndrome following bilateral damage involving the parietal lobes. The first two experiments used prolonged stimulus exposures and showed that unlike normals, the patient GK made independent actions to bilateral stimuli, even when explicitly instructed to make coordinated reaches. In contrast, bimanual actions to a single stimulus were coordinated in time. Experiments 3 and 4 employed reduced stimulus exposures to produce visual extinction. We found comparable extinction effects in detection and action, along with improved bimanual movements when the stimuli were grouped by collinearity and surface contrast, plus better coordination with bilateral stimuli proximity. The results are discussed in relation to the common role of visual selection processes in perception and action.