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British dietary recommendations are to decrease total fat intake to less than 30 % of daily energy intake and saturated fat to less than 10 %. In practice, it is difficult for people to make these changes. It may be easier to encourage people to switch from a diet rich in saturated fatty acids to one rich in polyunsaturated fatty acids. A total of 17 subjects - six people with Type II (non-insulin-dependent) diabetes mellitus, six non-obese and five obese people without diabetes - were randomised to spend two 5-week periods on a diet rich in saturated or in polyunsaturated fatty acids, in a crossover design. At the start of the study and after each dietary period, we assessed abdominal fat distribution using magnetic resonance imaging, insulin sensitivity using hyperinsulinaemic-euglycaemic clamps and fasting lipid parameters. Dietary compliance, assessed by weekly 3-day dietary records and measurement of biochemical markers, was good. Energy and fat intake appeared to be reduced on the diet rich in polyunsaturated fatty acids although body weights did not change. Insulin sensitivity and plasma low density lipoprotein cholesterol concentrations improved with the diet rich in polyunsaturated fatty acids compared with the diet rich in saturated fatty acids. There was also a decrease in abdominal subcutaneous fat area. If this result is confirmed in longer-term studies, this dietary manipulation would be more readily achieved by the general population than the current recommendations and could result in considerable improvement in insulin sensitivity, reducing the risk of developing Type II diabetes.

Regulation of Dietary Fatty Acid Entrapment in Subcutaneous Adipose Tissue and Skeletal Muscle Kevin Evans 1 , Graham C. Burdge 2 , Stephen A. Wootton 2 , Mo L. Clark 3 and Keith N. Frayn 3 1 Department of Clinical Chemistry, Staffordshire General Hospital, Stafford, U.K. 2 Institute of Human Nutrition, University of Southampton, Southampton, U.K. 3 Oxford Centre for Diabetes, Endocrinology, and Metabolism, Oxford, U.K. Abstract Using stable isotopic labeling of dietary fatty acids in conjunction with arteriovenous difference measurements, we have assessed the regulation of lipoprotein lipase-derived fatty acid entrapment in subcutaneous adipose tissue and forearm muscle in healthy subjects in the postprandial state. Eight volunteers fasted overnight and were then given a mixed meal containing [ 1- 13 C]palmitic acid and [1- 13 C]oleic acid. At baseline and for 6 h after the meal, blood samples were obtained from an arterialized hand vein and veins draining subcutaneous abdominal adipose tissue and forearm muscle, and arteriovenous differences were calculated. Entrapment of labeled fatty acids released by circulating triacylglycerol hydrolysis was close to 100% at 60 min, decreasing to 10–30% by 360 min. Entrapment of labeled fatty acids in forearm muscle was >100% and did not change with time. This study shows that entrapment of dietary fatty acids in adipose tissue in the postprandial period is a highly regulated process (varying with time) and that this can be studied in humans using stable isotope- labeled fatty acids in combination with measurement of appropriate arteriovenous differences. Also, fatty acid trapping in skeletal muscle is fundamentally different from that in adipose tissue, in that all the fatty acids released by lipoprotein lipase in skeletal muscle are taken up by the tissue. Footnotes Address correspondence and reprint requests to Dr. Kevin Evans, Department of Clinical Chemistry, Staffordshire General Hospital, Weston Road, Stafford, ST16 3SA UK. E-mail: kevin.evans{at}msgh-tr.wmids.nhs.uk . Received for publication 7 January 2002 and accepted in revised form 4 June 2002. ATBF, adipose tissue blood flow; A-V, arteriovenous difference; FAME, fatty acid methyl ester; GC-IRMS, gas chromatography-isotope ratio mass spectrometry; HSL, hormone-sensitive lipase; LPL, lipoprotein lipase; NEFA, nonesterified fatty acid; TAG, triacylglycerol; V-A, veno-arterial difference. DIABETES

Understanding the current status of the world's tropical rain forests (TRF) can be greatly advanced by global coverage of remotely sensed data at the scale of individual tree crowns. In 1999 the IKONOS satellite began offering worldwide 1-m panchromatic and 4-m multispectral data. Here we show that these data can be used to address diverse aspects of forest ecology and land-use classification in the tropics. Using crowns of emergent trees as control points, we georeferenced a 600-ha subset of IKONOS 1-m and 4-m data from an August 2000 image of the La Selva Biological Station, Costa Rica (root mean square error = 4.3 m). Crown area measured on the image was highly correlated with crown area for the same tree measured from the ground. Using a 1988 aerial photograph as a baseline, all trees >1 m diameter in a long-term study that died over the ensuing 12-year period, and that could be located in the photograph, were detected as missing in the IKONOS image (N = 7). Crown growth for large trees visible on both images averaged$12 m^{2}/yr$(N = 16). We thus demonstrate that IKONOS imagery can provide data on four variables necessary for doing demographic research: tree size, location, mortality, and growth. Stand basal area, estimated aboveground biomass, and percentage of the canopy >15 m tall for 18 0.5-ha permanent forest inventory plots in old growth were all highly significantly correlated with different indices derived from the IKONOS data. We used summary statistics from the original IKONOS data as well as derived indices to characterize nine areas with well-documented land-use histories. Secondary forests were clearly separable from the other sites. One of the secondary forests was 40 years old, suggesting that IKONOS data can be used to detect significantly older secondary forest than is possible with coarser resolution satellite data. The selectively logged forest was distinguishable by measuring the size of the largest crowns on the 1-m image. This suggests a range of applications for detecting and quantifying biomass degradation due to selective logging and edge effects. Satellite data at 1-m and 4-m resolution make possible a truly global approach to fine spatial resolution remote-sensing studies of TRF ecology and land use.

Palliative treatment is appropriate for most patients with cancer of the head of pancreas. Insertion of a biliary stent relieves jaundice and pruritus but it is not known if stenting affects other symptoms or changes the quality of life. Nineteen patients have completed a standard questionnaire to assess symptom relief and quality of life after stent insertion. After stenting there was complete relief of jaundice and pruritus. Furthermore, there was also considerable improvement in anorexia and indigestion. All patients had anorexia before stent insertion, this was moderate/severe in 13 (68.4%). Anorexia was significantly better (p < 0.01) a week after stenting and this benefit was maintained at 12 weeks (p < 0.01). Sixteen (84.2%) patients complained of indigestion before stenting, moderate/severe in 11 (57.9%). This was significantly better (p < 0.01) a week after stenting with complete relief in six at eight weeks (p < 0.01). Fifteen (78.9%) felt that their mood was good/very good before stent insertion and this was unchanged even at the 12 week assessment. A similar result was obtained for physical health and level of activity. In conclusion stent insertion not only relieves jaundice and pruritus in these patients but also improves other symptoms and quality of life. The considerable improvement in appetite after stenting was of particular benefit.

Elemental diet is as effective as corticosteroids in the treatment of previously untreated Crohn's disease. It is unclear whether a poor nutritional state is a prerequisite for efficacy of elemental diet, whether previously treated patients respond as well, or how duration of remission using elemental diet compares with corticosteroid induced remission. Forty two patients with active Crohn's disease were stratified for nutritional state and randomised to receive Vivonex TEN 2.1 l/day for four weeks, or 0.75 mg prednisolone/kg/day for two weeks and subsequent reducing doses. Nine of 22 (41%) patients assigned to nutritional treatment were intolerant of the diet. Thirty patients completed four weeks treatment. Disease activity decreased on elemental diet from mean (SEM) 4.8 (0.9) to 1.7 (0.6), p < 0.05, and on prednisolone from 5.3 (0.5) to 1.9 (0.6), p < 0.05. For each treatment, nourished and malnourished patients responded similarly. Patients with longstanding disease responded as well as newly diagnosed patients. The probability of maintaining remission at six months was 0.67 after prednisolone, 0.28 after elemental diet, and at one year was 0.35 after prednisolone and 0.09 after elemental diet, p < 0.05. When tolerated, elemental diet is as effective in the short term as prednisolone in newly and previously diagnosed Crohn's disease, and its benefit is independent of nutritional state. The subsequent relapse rate after elemental diet induced remission, however, is greater than after treatment with prednisolone.

The chest radiograph showed a distracted left clavicle fracture with the medial border of the left scapula displaced laterally (Fig. 1, left). A computed tomographic (CT) scan confirmed this finding and also revealed a fracture through the middle of the scapula but not entering the glenoid, with notable soft-tissue disruption (Fig. 1, right). Angiography established spasm of the left brachial artery without evidence of major vessel injury. FIG. 1. Left, a chest radiograph showing a wide mediastinum, widely displaced clavicular fracture, lateral displaced scapula and subcutaneous emphysema. Right, computed tomographic (CT) scan demonstrating severe soft-tissue swelling, a large chest-wall hematoma, small mediatinal hematoma and laterally displaced scapula. Treatment is dictated by the spectrum of injuries present.4 Surgical repair of a vascular injury is recommended,2'5 and exploration of a documented brachial plexus injury is warranted.2,4,5 Operative treatment of the displaced clavicular fracture can stabilize the shoulder girdle, avoid delayed or nonunion of the clavicle fracture and protect the brachial plexus and axillary artery from further distracting forces.2 Support of soft-tissue structures with immobilization for 6 weeks is appropriate before physical therapy to return range of motion.2 Outcomes depend on the state of the brachial plexus and other injuries that are present, and can range from normal function to a flail limb requiring fusion or amputation.

BACKGROUND: L-Arginine has been shown to induce fluid secretion in human jejunum. Nitric oxide, a derivative of L-arginine is thought to have an important role as an intestinal secretagogue. AIM: To determine the effect of L-arginine and the nitric oxide synthase inhibitor, nitro L-arginine methyl ester (L-NAME), on fluid and electrolyte movement in rat jejunum. METHODS: A 25 cm segment of rat jejunum was perfused in situ with iso-osmotic solutions containing either (1) saline, (2) D-arginine 20, (3) L-arginine 20, (4) L-NAME 0.1, 1, or 20 mmol/l, or (5) a combination of L-arginine 20 and L-NAME 0.1, 1, or 20 mmol/l. In further groups the effect of a subcutaneous injection of L-NAME 100 mg/kg was examined in rats pretreated with either D-or L-arginine 500 mg/kg. RESULTS: L-Arginine, unlike D-arginine, induced fluid secretion despite being better absorbed (mean -7.3 v 17.0 microliters/min/g; p < 0.01). L-NAME at 0.1 mmol/l had no effect on basal fluid movement but reversed L-arginine induced secretion (7.8; p < 0.05). L-NAME at 1 and 20 mmol/l induced fluid secretion (-15.4 and -28.4, respectively), which was enhanced by the addition of L-arginine (-30.0 and -41.0, respectively; both p < 0.05). A subcutaneous injection of L-NAME resulted in marked fluid secretion (-39.9) and histological evidence of intestinal ischaemia. These changes were attenuated or reversed by pretreatment with subcutaneous L- but not D-arginine. CONCLUSIONS: L-arginine induces intestinal fluid secretion through production of nitric oxide. There is a delicate balance between the effect of nitric oxide as a secretagogue and its effect on maintaining blood flow and thus preventing intestinal ischaemia.

A study investigated the relationship between friendship expectations and the evaluation of present friendships to determine if early adolescents get what they expect from their close friendships. The study yielded data on reciprocity and gender differences for the criteria used by adolescents to select friends and the evaluation of present friends.

We studied the relationship of reciprocity, gender, and racial composition (Caucasian, African American, cross-race) of adolescent friendship dyads to similarity and proximity in 136 young adolescents. We found that adolescents selected friends who were of the same gender and race and that female dyads were more similar than male dyads on verbal achievement and several personality dimensions. Caucasian dyads were more similar than African American dyads on verbal achievement, mental alertness, and dominance. African American adolescents had more contact with their best friends outside school, whereas Caucasian adolescent friends had more in-school contact. African American students had fewer reciprocal relationships than the Caucasian students. Cross-race friendships were less reciprocal than same-race friendships. Race and gender were important in determining friendship patterns. Similarity and proximity were more important than reciprocity in understanding early adolescent friendships.

OBJECTIVE: To test the hypothesis that intravenous infusion of lipid would bring about changes in adipose tissue metabolism, which would tend to spare net fat mobilization, and to attempt to identify the mediators of such responses. DESIGN: The triacylglycerol (TG) emulsion. Intralipid, was infused and metablic changes in subcutaneous adipose tissue and forearm muscle were assessed by measurements of arterio-venous differences. SUBJECTS: Six normal male subjects aged 21-37 y, with body mass index (BMI) 23.0-25.9 kg/m2. RESULTS. Plasma TG and non-esterified fatty acid (NEFA) concentrations rose during infusion as expected. The rise in systemic plasma NEFA concentration occurred despite decreased NEFA release from adipose tissue. Intralipid infusion resulted in a suppression of intracellular lipolysis in adipose tissue, by mechanisms which are not clear. Plasma leptin concentrations, measured in a search for the regulator of lipolysis, showed consistent leptin release from adipose tissue which did not change significantly with time. CONCLUSION: The suppression of intracellular lipolysis in adipose tissue during Intralipid infusion is a new observation and may reflect a novel mechanism for regulation of fat storage.