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Sjöström L, Rissanen A, Andersen T, Boldrin M, Golay A, Koppeschaar HP, Krempf M. Randomised placebo-controlled trial of orlistat for weight loss and prevention of weight regain in obese patients. European Multicentre Orlistat Study Group. Lancet 1998; 352:167-72. [PMID: 9683204 DOI: 10.1016/s0140-6736(97)11509-4] [Citation(s) in RCA: 700] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND We undertook a randomised controlled trial to assess the efficacy and tolerability of orlistat, a gastrointestinal lipase inhibitor, in promoting weight loss and preventing weight regain in obese patients over a 2-year period. METHODS 743 patients (body-mass index 28-47 kg/m2), recruited at 15 European centres, entered a 4-week, single-blind, placebo lead-in period on a slightly hypocaloric diet (600 kcal/day deficit). 688 patients who completed the lead-in were assigned double-blind treatment with orlistat 120 mg (three times a day) or placebo for 1 year in conjunction with the hypocaloric diet. In a second 52-week double-blind period patients were reassigned orlistat or placebo with a weight maintenance (eucaloric) diet. FINDINGS From the start of lead-in to the end of year 1, the orlistat group lost, on average, more bodyweight than the placebo group (10.2% [10.3 kg] vs 6.1% [6.1 kg]; LSM difference 3.9 kg [p<0.001] from randomisation to the end of year 1). During year 2, patients who continued with orlistat regained, on average, half as much weight as those patients switched to placebo (p<0.001). Patients switched from placebo to orlistat lost an additional 0.9 kg during year 2, compared with a mean regain of 2.5 kg in patients who continued on placebo (p<0.001). Total cholesterol, low-density lipoprotein (LDL) cholesterol, LDL/high-density lipoprotein ratio, and concentrations of glucose and insulin decreased more in the orlistat group than in the placebo group. Gastrointestinal adverse events were more common in the orlistat group. Other adverse symptoms occurred at a similar frequency during both treatments. INTERPRETATION Orlistat taken with an appropriate diet promotes clinically significant weight loss and reduces weight regain in obese patients over a 2-year period. The use of orlistat beyond 2 years needs careful monitoring with respect to efficacy and adverse events.
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Abstract
This prospective study was carried out in order to evaluate the influence on liver morphology and function of a very-low-calorie formula diet. Fourty-one morbidly obese, non-alcoholic subjects had liver biopsy performed before and after a median weight loss of 34 kg. Fatty change improved (p less than 0.001), but 24% of the patients developed slight portal inflammation (p = 0.039) or slight portal fibrosis (p = 0.063). Patients developing portal fibrosis had a higher degree of fatty change at entry (p = 0.029), a more pronounced reduction of fatty change (p = 0.014) and a faster weight loss (p = 0.026). Liver biochemistry, which was of no individual diagnostic value, improved. It is concluded that morbidly obese subjects with a high degree of hepatic fatty change are at risk of developing portal inflammation and fibrosis when undergoing very fast dietary weight reductions.
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Dai S, Ma Q, Liu MK, Andersen T, Fei Z, Goldflam MD, Wagner M, Watanabe K, Taniguchi T, Thiemens M, Keilmann F, Janssen GCAM, Zhu SE, Jarillo-Herrero P, Fogler MM, Basov DN. Graphene on hexagonal boron nitride as a tunable hyperbolic metamaterial. NATURE NANOTECHNOLOGY 2015; 10:682-6. [PMID: 26098228 DOI: 10.1038/nnano.2015.131] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/25/2015] [Indexed: 05/11/2023]
Abstract
Hexagonal boron nitride (h-BN) is a natural hyperbolic material, in which the dielectric constants are the same in the basal plane (ε(t) ≡ ε(x) = ε(y)) but have opposite signs (ε(t)ε(z) < 0) in the normal plane (ε(z)). Owing to this property, finite-thickness slabs of h-BN act as multimode waveguides for the propagation of hyperbolic phonon polaritons--collective modes that originate from the coupling between photons and electric dipoles in phonons. However, control of these hyperbolic phonon polaritons modes has remained challenging, mostly because their electrodynamic properties are dictated by the crystal lattice of h-BN. Here we show, by direct nano-infrared imaging, that these hyperbolic polaritons can be effectively modulated in a van der Waals heterostructure composed of monolayer graphene on h-BN. Tunability originates from the hybridization of surface plasmon polaritons in graphene with hyperbolic phonon polaritons in h-BN, so that the eigenmodes of the graphene/h-BN heterostructure are hyperbolic plasmon-phonon polaritons. The hyperbolic plasmon-phonon polaritons in graphene/h-BN suffer little from ohmic losses, making their propagation length 1.5-2.0 times greater than that of hyperbolic phonon polaritons in h-BN. The hyperbolic plasmon-phonon polaritons possess the combined virtues of surface plasmon polaritons in graphene and hyperbolic phonon polaritons in h-BN. Therefore, graphene/h-BN can be classified as an electromagnetic metamaterial as the resulting properties of these devices are not present in its constituent elements alone.
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Ayyad C, Andersen T. Long-term efficacy of dietary treatment of obesity: a systematic review of studies published between 1931 and 1999. Obes Rev 2000; 1:113-9. [PMID: 12119984 DOI: 10.1046/j.1467-789x.2000.00019.x] [Citation(s) in RCA: 211] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
METHODS MEDLINE surveys were carried out and reference lists were cross-checked to identify publications on long-term outcome for dietary treatment of obesity. 898 papers were identified, 17 fulfilled our planned criteria for inclusion (dietary treatment; adults; follow-up period > or = 3 years; follow-up rate > or = 50% of original study group; information on one of the success criteria: maintenance of all weight initially lost (or further weight reduction) or maintenance of at least nine to 11 kg of initial weight loss; obesity complications of the patient group not over-represented; English, German or Scandinavian languages). RESULTS The 17 included publications (here of three publications on randomized clinical trials with control group relevant for this review) reported on 21 study groups, comprising 3030 patients. Of these 2131 (70%) were followed-up for 3-14 years (median 5 years). Mean initial weight loss ranged from four to 28 kg (median 11 kg). Overall, 15% (median, range 0-49%) of followed-up patients fulfilled one of the criteria for success. Overall, success rates seemed stable for up to 14 years of observation. Diet combined with group therapy lead to better long-term success rates (median 27%) than did diet alone (median 15%) or diet combined with behaviour modification (median 14%). Active follow-up was generally associated with better success rates than was passive follow-up (19% vs. 10%). Conventional diet seemed to be most efficacious in addition with group therapy, whereas VLCD apparently was most efficacious if combined with behaviour modification and active follow-up. CONCLUSION The literature on long-term follow-up of dietary treatment of obesity, although limited and inhomogeneous, points to an overall median success rate of 15% and a possible adjuvant effect of group therapy, behaviour modification and active follow-up.
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Review |
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Dai S, Ma Q, Andersen T, Mcleod AS, Fei Z, Liu MK, Wagner M, Watanabe K, Taniguchi T, Thiemens M, Keilmann F, Jarillo-Herrero P, Fogler MM, Basov DN. Subdiffractional focusing and guiding of polaritonic rays in a natural hyperbolic material. Nat Commun 2015; 6:6963. [PMID: 25902364 PMCID: PMC4421822 DOI: 10.1038/ncomms7963] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 03/19/2015] [Indexed: 12/24/2022] Open
Abstract
Uniaxial materials whose axial and tangential permittivities have opposite signs are referred to as indefinite or hyperbolic media. In such materials, light propagation is unusual leading to novel and often non-intuitive optical phenomena. Here we report infrared nano-imaging experiments demonstrating that crystals of hexagonal boron nitride, a natural mid-infrared hyperbolic material, can act as a ‘hyper-focusing lens' and as a multi-mode waveguide. The lensing is manifested by subdiffractional focusing of phonon–polaritons launched by metallic disks underneath the hexagonal boron nitride crystal. The waveguiding is revealed through the modal analysis of the periodic patterns observed around such launchers and near the sample edges. Our work opens new opportunities for anisotropic layered insulators in infrared nanophotonics complementing and potentially surpassing concurrent artificial hyperbolic materials with lower losses and higher optical localization. Hexagonal boron nitride has many interesting properties, including a natural hyperbolic dispersion, making it attractive for nanophotonic applications. Here, Dai et al. show that metallic disks under the material launch phonon–polaritons, turning it into a hyper-focusing lens.
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Research Support, U.S. Gov't, Non-P.H.S. |
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Neumark DM, Lykke KR, Andersen T, Lineberger WC. Laser photodetachment measurement of the electron affinity of atomic oxygen. PHYSICAL REVIEW. A, GENERAL PHYSICS 1985; 32:1890-1892. [PMID: 9896287 DOI: 10.1103/physreva.32.1890] [Citation(s) in RCA: 176] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Andersen T, Christensen FB, Laursen M, Høy K, Hansen ES, Bünger C. Smoking as a predictor of negative outcome in lumbar spinal fusion. Spine (Phila Pa 1976) 2001; 26:2623-8. [PMID: 11725245 DOI: 10.1097/00007632-200112010-00018] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A review of the smoking habits in 426 patients who had been followed prospectively for 2 years after a lumbar spinal fusion procedure was conducted. OBJECTIVE To analyze the effect of pre- and postoperative smoking on clinical and functional outcome after lumbar spinal fusion. SUMMARY OF BACKGROUND DATA Several animal models have shown a negative effect of nicotine on spinal fusion. At this writing, the clinical effect of nicotine on spinal fusion has not been fully clarified. METHODS The study comprised 426 patients who underwent lumbar spinal fusion between 1993 and 1997. These patients received a mailed questionnaire regarding their tobacco consumption before and after their surgery. All other data, including preoperative clinical and functional status, were collected prospectively during a 2-year follow-up period. To assess functional outcome, the Dallas Pain Questionnaire was used. RESULTS The questionnaire was answered by 396 patients (93%). Of these patients, 54.5% (20% more than the background population) were smokers before the operation. Smoking of more than 10 cigarettes daily before the operation and attempted fusion at two or more levels increased the risk of nonunion: odds ratio, 2.01 (P < 0.016) and odds ratio, 3.03 (P < 0.001), respectively. Smoking cessation increased fusion rates to near those of nonsmokers. Smoking had no influence on functional outcome, as assessed by the Dallas Pain Questionnaire, but preoperative smoking predicted a negative answer to the question "Would you undergo the same treatment again, now that you know the result?" (odds ratio, 1.65; P < 0.054). CONCLUSIONS Smoking was shown to have a negative effect on fusion and overall patient satisfaction, but no measurable influence on the functional outcome as assessed by the Dallas Pain Questionnaire.
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Ek J, Urhammer SA, Sørensen TI, Andersen T, Auwerx J, Pedersen O. Homozygosity of the Pro12Ala variant of the peroxisome proliferation-activated receptor-gamma2 (PPAR-gamma2): divergent modulating effects on body mass index in obese and lean Caucasian men. Diabetologia 1999; 42:892-5. [PMID: 10440134 DOI: 10.1007/s001250051243] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
AIMS/HYPOTHESIS The objectives of the present investigation were to examine: 1) whether a Pro115Gln variant in the peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) is associated with juvenile-onset obesity among Danish Caucasianmen and 2) whether the relation of a Pro12Ala polymorphism in PPAR-gamma2 with BMI and long-term weight regulation differ between lean and obese subjects within the same cohort. METHODS The Pro115Gln and Pro112Ala variants were examined using PCR and RFLP in a group of 752 subjects with a Body Mass Index (BMI) of 31.0 kg/m2 or more and in 869 non-obese control subjects. RESULTS We did not find Pro115Gln in any of the 1621 male subjects we examined. Among the males with juvenile-onset obesity, the allelic frequency of the Pro12Ala polymorphism was 14% (95% confidence interval: 12-16%) compared with 16% (14-17%) among the non-obese control subjects (NS). Heterozygosity of the codon 12 variant was not associated with differences in BMI or changes in body weight regulation during follow up in lean or obese subjects. In the group of obese subjects, 21 homozygous Ala12Ala carriers had, however, a higher BMI (38.9 +/- 5.4 kg/m2 (means +/- SD) vs 35.5 +/- 5.5 kg/ m2, p = 0.008) and a higher weight gain (0.27 +/- 0.24 kg x m(-2) x year(-1) vs 0.10 +/- 0.24 kg x m(-2) x year(-1), p = 0.004), compared with wild-type carriers. Moreover, within the control group of 869 men the 14 homozygous carriers of the variant had a lower BMI (24.4 +/- 2.7 kg/m2 vs 26.2 +/- 3.7 kg/m2, p = 0.005) and a slower increase in BMI (0.11 +/- 0.11 kg x m(-2) x year(-1) vs 0.17 +/- 0.11 kg x m(-2) x year(-1), p = 0.002) compared with wild-type carriers. CONCLUSION/INTERPRETATION The codon 12 variant of PPAR-gamma2 is not intrinsically associated with juvenile obesity. The variant may in its homozygous form interact, however, with various combinations of genetic and environmental factors in lean and obese subjects to cause divergent modulating effects on BMI and long-term body weight control.
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Abstract
An analysis was made of weight changes during treatment with valproate in 63 adult epileptic patients. 36 patients (57%) gained more than 4 kg in weight during treatment, while 27 patients (43%) were stable in weight with weight changes of less than +/- 4 kg. There were no significant differences between weight gainers and weight-stable patients with regard to age, sex, pretreatment overweight, duration of treatment, dosage or serum levels of valproate. From structured patient interviews, it appeared that the 2 groups of patients differed only insignificantly with regard to appetite, thirst and familial predispositions to obesity and diabetes. Consequently, no factors predictive for weight gain could be outlined. Presumable pathogenic mechanisms of importance are discussed.
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Hjortsø NC, Neumann P, Frøsig F, Andersen T, Lindhard A, Rogon E, Kehlet H. A controlled study on the effect of epidural analgesia with local anaesthetics and morphine on morbidity after abdominal surgery. Acta Anaesthesiol Scand 1985; 29:790-6. [PMID: 4082879 DOI: 10.1111/j.1399-6576.1985.tb02302.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A hundred patients scheduled for elective abdominal surgery were randomized to either general anaesthesia (low-dose fentanyl) and systemic morphine for postoperative pain or combined general anaesthesia and epidural analgesia with etidocaine 1.5% intraoperatively (T4-S5) and bupivacaine 0.5% 5 ml/4 h for 24 h and morphine 4 mg/12 h for 72 h. Postoperative pain was better controlled by the epidural regimen (P less than 0.0001). We found no significant reduction in postoperative mortality (6% to 2%), pneumonia (28% to 20%), cardiac dysrhythmia (10% to 5%) and wound complications (14% to 11%) by the epidural analgesic regimen. The incidence of deep venous thrombosis (125I-fibrinogen scan) was 32% after general anaesthesia and low-dose heparin and 34% after epidural analgesia with no prophylactic antithrombotic treatment (P greater than 0.9). Postoperative weight loss and decrease in serum-albumin and serum-transferrin, as well as the reduction in haemoglobin and the need for postoperative transfusions, were similar in the two groups. Convalescence, as assessed by postoperative fatigue, restoration of bowel function (flatus, bowel movement and food intake) and the time until the patients were self-aided at their preoperative level, was not reduced by epidural analgesia. Since 50% of the patients in each group suffered from one or more of the above-mentioned postoperative complications, this epidural regimen was not effective in reducing postoperative morbidity after major abdominal surgery despite the achievement of adequate pain relief.
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Andersen T, Fogh J. Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients. J Hum Nutr Diet 2001; 14:243-50. [PMID: 11424516 DOI: 10.1046/j.1365-277x.2001.00290.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Obesity and overweight may soon affect more than half of the population in some regions of the world and are associated with diabetes, hypertension and other diseases that cause morbidity, mortality and high health-care expenditure. No one approach, whether dietetic management, medication, or commercial weight loss programme, can alone solve the problem--all potential treatments need to be investigated and exploited. Among the herbal preparations known to non-western cultures are materials which may have applications in modulating physiological processes which influence gut motility, food intake and energy balance. One such mixed herbal preparation is 'YGD' containing Yerbe Maté (leaves of Ilex paraguayenis), Guarana (seeds of Paullinia cupana) and Damiana (leaves of Turnera diffusa var. aphrodisiaca). AIMS This study had two distinct aims: to determine the effect of a herbal preparation 'YGD' containing Yerbe Maté, Guarana and Damiana on gastric emptying; to determine the effect of the same preparation on weight loss over 10 days and 45 days and weight maintenance over 12 months. METHODS Gastric emptying was observed using ultrasound scanning in seven healthy volunteers following YGD and placebo capsules taken with 420 mL apple juice. Body weight was observed before and after 10 days of treatment with three YGD capsules or three placebo capsules before each meal for 10 days in 44 healthy overweight patients attending a primary health care centre. Forty-seven healthy overweight patients entered a double-blind placebo-controlled parallel trial of three capsules of YGD capsules before each main meal for 45 days compared with three placebo capsules on body weight. Body weight was monitored in 22 patients who continued active (YGD capsules) treatment for 12 months. RESULTS The herb preparation YGD was followed by a prolonged gastric emptying time of 58 +/- 15 min compared to 38 +/- 7.6 min after placebo (P = 0.025). Body weight reductions were 0.8 +/- 0.05 kg after YGD capsules compared to 0.3 +/- 0.03 kg after placebo capsules over 10 days, and 5.1 +/- 0.5 kg after PGD capsules compared to 0.3 +/- 0.08 kg after placebo over 45 days. Active treatment with YGD capsules resulted in weight maintenance of the group (73 kg at the beginning and 72.5 kg at the end of 12 months). CONCLUSIONS The herbal preparation, YGD capsules, significantly delayed gastric emptying, reduced the time to perceived gastric fullness and induced significant weight loss over 45 days in overweight patients treated in a primary health care context. Maintenance treatment given in an uncontrolled context resulted in no further weight loss, nor weight regain in the group as a whole. The herbal preparation is thus shown to be one that significantly modulates gastric emptying. Further clinical studies with dietetic monitoring of energy intake, dietary quality, satiety ratings, body weight and body composition are now indicated, and examination of the active principles contained in the three herbal components may prove rewarding.
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Clinical Trial |
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Hyldstrup L, Andersen T, McNair P, Breum L, Transbøl I. Bone metabolism in obesity: changes related to severe overweight and dietary weight reduction. ACTA ENDOCRINOLOGICA 1993; 129:393-8. [PMID: 8279220 DOI: 10.1530/acta.0.1290393] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A non-invasive evaluation of bone metabolism was performed in 44 morbidly obese patients before and after a mean weight loss of 22.4 kg (range 7.9-43.4 kg) after 2 months and a further weight loss of 7.3 kg after 8 months (0.8-20.0 kg). This weight reduction was obtained by a nutritionally adequate very-low-calorie diet. Before treatment the bone mineral content of the distal forearm was increased compared to normals (51.9 U vs. 43.7 U, p < 0.001). Bone formation was evaluated by serum alkaline phosphatase and serum osteocalcin. Serum alkaline phosphatase was increased (187.8 U/l vs 147.4 U/l, p < 0.001) while serum osteocalcin was lower than in the controls (0.67 nmol/l vs 0.98 nmol/l, p < 0.01). Bone resorption, as measured by the urinary hydroxyproline/creatinine ratio, was not increased in the obese patients (19.2 molar ratio x 10(-3) vs 16.7 molar ratio x 10(-3), NS). After 2 months, the bone mineral content had declined by 3.3%. Serum alkaline phosphatase remained unchanged (187.8 U/l vs 186.9 U/l, NS) but serum osteocalcin demonstrated a significant rise (3.94 nmol/l vs 10.53 nmol/l, p < 0.001), parallel to changes in the hydroxyproline/creatinine ratio (19.2 molar ratio x 10(-3) vs 25.2 molar ratio x 10(-3), p < 0.001). At 8 months, no further change in the bone mineral content was seen. The hydroxyproline/creatinine ratio did still increase (from 25.8 molar ratio x 10(-3) to 30.1 molar ratio x 10(-3), p < 0.05), while serum alkaline phosphatase and serum osteocalcin remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)
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Clinical Trial |
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Andersen T, Backer OG, Stokholm KH, Quaade F. Randomized trial of diet and gastroplasty compared with diet alone in morbid obesity. N Engl J Med 1984; 310:352-6. [PMID: 6690963 DOI: 10.1056/nejm198402093100604] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We compared the weight-reducing effect of diet and gastroplasty with that of diet alone in a randomized trial in 60 morbidly obese patients followed for two years. Initial median body weight was 120 kg in patients randomly assigned to gastroplasty plus diet and 115 kg in those assigned to diet alone. Maximum weight losses did not differ significantly between the groups (26.1 kg in the gastroplasty group and 22.0 kg in the group treated with diet alone, P greater than 0.05). The risk of a Type II error with a true difference larger than 9.5 kg was less than 5 per cent. However, the group treated with diet alone regained significantly more weight after maximum weight loss had been achieved, so that the gastroplasty group had a more favorable net outcome at two years (P less than 0.05).
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Clinical Trial |
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Miller LE, van Kan PL, Sinkjaer T, Andersen T, Harris GD, Houk JC. Correlation of primate red nucleus discharge with muscle activity during free-form arm movements. J Physiol 1993; 469:213-43. [PMID: 8271199 PMCID: PMC1143869 DOI: 10.1113/jphysiol.1993.sp019812] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
1. We recorded from 239 neurons located in the magnocellular division of the red nucleus of four alert macaque monkeys. At the same time, we recorded electromyographic (EMG) signals from as many as twenty electrodes chronically implanted on muscles of the shoulder, arm, forearm and hand. We recorded EMG signals for periods ranging from several months to a year. 2. The monkeys were trained to perform three free-form food retrieval tasks, each of which activated all of the recorded muscles and most of the neurons. The 'prehension' task required simply that the monkey grasp a piece of food from a fixed point in space. The 'barrier' task required the monkey to reach around a small barrier to obtain the food, and the 'Kluver' task required that food be removed from small holes. During the prehension task, we found approximately equal numbers of neurons that were strongly active while the hand was being moved toward the target (70% of units), and while the food was being grasped (60%). Relatively few units were active as the hand was returned to the mouth (15%). 3. Data files of 1-2 min duration were collected while the monkey performed a single behavioural task. Whenever possible, we recorded files for all three tasks from each neuron. For each file we calculated long time-span analog cross-correlations (+/- 1.28 s) between instantaneous neuronal firing rate and each of the full-wave rectified, low-pass filtered EMG signals. We used the peak correlation and the time of the peak as two summary measures of the functional relation between modulation of neuronal activity and EMG. 4. The magnitude of the strongest correlations was between 0.4 and 0.5 (normalized to a perfect correlation of +/- 1.0). Distal muscles were the most frequently correlated, and extensors were more frequently correlated than flexors. For all monkeys, the lags for well correlated muscles were distributed broadly about a uni-modal value near 0 ms. Eighty five per cent of the correlations larger than or equal to 0.25 had peaks between -150 and 200 ms. 5. The activity of each neuron was represented in a muscle co-ordinate system by an n-dimensional 'functional linkage vector', each element of which was the peak correlation with one of n muscles. The vector for any given neuron points in a particular direction in muscle space, depending on the similarity between the activity of the neuron and the activity of each muscle.(ABSTRACT TRUNCATED AT 400 WORDS)
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Breum L, Astrup A, Gram L, Andersen T, Stokholm KH, Christensen NJ, Werdelin L, Madsen J. Metabolic changes during treatment with valproate in humans: implication for untoward weight gain. Metabolism 1992; 41:666-70. [PMID: 1640853 DOI: 10.1016/0026-0495(92)90061-e] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This study was initiated to elucidate the mechanisms behind valproate-induced weight gain. Eight patients with epilepsy were studied with identical examination programs before and during the end of the first month of treatment with sodium valproate (VPA). The measurements included registration of food intake, indirect calorimetry, and determination of pancreatic and thyroid hormones, catecholamines, albumin, electrolytes, glycerol, and free fatty acids. Measurements were performed both at the basal condition and during a 3-hour oral glucose tolerance test (OGTT). After the start of VPA treatment, the mean levels during the OGTT of plasma glucose and catecholamines were significantly decreased by 7% and 25%, respectively (P less than .05). The mean ratio of insulin to glucagon decreased by 37% (P less than .01). During the glucose load, the decreases in free fatty acids were less pronounced after the start of VPA treatment, whereas the mean levels of glycerol were found to be unchanged. We detected no differences between the two periods with regard to total energy intake or macronutrient selection, energy expenditure, or thyroid hormones. As VPA is known to affect the concentration of carnitine in humans, it is hypothesized that a possible VPA-induced deficiency of the beta-oxidation of fatty acids is important for the development of obesity in epileptic patients in long-term treatment with VPA, but changes in catecholamines or other hormones might also be of importance.
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Barrow LL, van Bokhoven H, Daack-Hirsch S, Andersen T, van Beersum SEC, Gorlin R, Murray JC. Analysis of the p63 gene in classical EEC syndrome, related syndromes, and non-syndromic orofacial clefts. J Med Genet 2002; 39:559-66. [PMID: 12161593 PMCID: PMC1735218 DOI: 10.1136/jmg.39.8.559] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
EEC syndrome is an autosomal dominant disorder with the cardinal signs of ectrodactyly, ectodermal dysplasia, and orofacial clefts. EEC syndrome has been linked to chromosome 3q27 and heterozygous p63 mutations were detected in unrelated EEC families. In addition, homozygous p63 null mice exhibit craniofacial abnormalities, limb truncations, and absence of epidermal appendages, such as hair follicles and tooth primordia. In this study, we screened 39 syndromic patients, including four with EEC syndrome, five with syndromes closely related to EEC syndrome, and 30 with other syndromic orofacial clefts and/or limb anomalies. We identified heterozygous p63 mutations in three unrelated cases of EEC syndrome, two Iowa white families and one sporadic case in a Filipino boy. One family is atypical for EEC and has features consistent with Hay-Wells syndrome. In this family, the mutation ablates a splice acceptor site and, in the other two, mutations produce amino acid substitutions, R280C and R304Q, which alter conserved DNA binding sites. Germline mosaicism was detected in the founder of the mutation in one case. These three cases show significant interfamilial and intrafamilial variability in expressivity. We also screened p63 in 62 patients with non-syndromic orofacial clefts, identifying an intronic single nucleotide polymorphism but finding no evidence of mutations that would explain even a subset of non-syndromic orofacial clefts. This study supports a common role for p63 in classical EEC syndrome, both familial and sporadic, but not in other related or non-syndromic forms of orofacial clefts.
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Rasmussen MH, Frystyk J, Andersen T, Breum L, Christiansen JS, Hilsted J. The impact of obesity, fat distribution, and energy restriction on insulin-like growth factor-1 (IGF-1), IGF-binding protein-3, insulin, and growth hormone. Metabolism 1994; 43:315-9. [PMID: 7511202 DOI: 10.1016/0026-0495(94)90099-x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The aim of this study was to characterize the association between serum insulin-like growth factor-1 (IGF-1) and obesity, as well as fat distribution, before and during moderate energy restriction (1,200 kcal/d). In 51 females and nine males having a body mass index (BMI) between 27 and 39 kg/m2, relationships between serum IGF-1, IGF-binding protein-3 (IGFBP-3), insulin, growth hormone (GH), blood glucose, and anthropometric measurements of body fat were examined. The patients were studied before treatment and again after 8 and 16 weeks of dieting. Visceral adipose tissue (AT) was estimated by anthropometric computed tomography (CT)-calibrated equations. In females, IGF-1 was inversely associated with the abdominal sagittal diameter (SagD) and with the visceral AT (r = -.41, P = .006). No significant correlations were found between IGF-1 and BMI or other indices of adiposity. Weight loss caused a temporary increase in IGF-1 concentrations (P = .03) and continued decrements in blood glucose levels (P = .0004 at 16 weeks). A statistically significant inverse correlation between IGF-1 and blood glucose levels was present before (r = -.30, P = .02) and after 8 (r = -.37, P = .007) and 16 (r = .02, P = .02) weeks of dietary treatment. Both serum IGF-1 and insulin levels were positively correlated with serum IGFBP-3 levels (r = .34, P = .009 and r = .34, P = .008, respectively). We conclude that IGF-1 levels in obese females reflect the intraabdominal fat mass rather than obesity per se. IGF-1 and blood glucose levels are inversely correlated in obesity before and during energy restriction.
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Clinical Trial |
31 |
72 |
18
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Wollesen F, Andersen T, Karle A. Size reduction of extrasellar pituitary tumors during bromocriptine treatment. Ann Intern Med 1982; 96:281-6. [PMID: 7059088 DOI: 10.7326/0003-4819-96-3-281] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The well-known size-reducing effect of bromocriptine on prolactinomas was tested on five types of large, extrasellar pituitary tumors. Twenty patients were treated prospectively for up to 4.5 years with bromocriptine, 30 or 60 mg/d (two patients received 15 mg and 160 mg, respectively). The effect on the size of the pituitary tumors was quantitated by planimetry of computed tomographic scans before and during treatment. The immediate success rate was 16 of 20 tumors. Eleven nonsecreting tumors were reduced by a median of 32% (range of reduction for 50% of cases, 18%-41%) with an immediate success rate of nine of 11. Nine secreting tumors (four that secreted prolactin; three, growth hormone; one, adrenocorticotropic hormone; and one, thyroid stimulating hormone) were reduced by a median of 51% (range of reduction for 50% of cases, 25%-72%). The reduction in tumor size was significantly associated with pretreatment size (r=0.6360, p less than 0.005), but not with the serum concentration of any hormones assayed or previous radiation treatment. Bromocriptine causes a clinically significant reduction in size of nonsecreting as well as secreting pituitary tumors with the same success rate as that of conventional treatments.U
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43 |
70 |
19
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Andersen TB, López CQ, Manczak T, Martinez K, Simonsen HT. Thapsigargin--from Thapsia L. to mipsagargin. Molecules 2015; 20:6113-27. [PMID: 25856061 PMCID: PMC6272310 DOI: 10.3390/molecules20046113] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 03/26/2015] [Accepted: 03/30/2015] [Indexed: 12/23/2022] Open
Abstract
The sesquiterpene lactone thapsigargin is found in the plant Thapsia garganica L., and is one of the major constituents of the roots and fruits of this Mediterranean species. In 1978, the first pharmacological effects of thapsigargin were established and the full structure was elucidated in 1985. Shortly after, the overall mechanism of the Sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) inhibition that leads to apoptosis was discovered. Thapsigargin has a potent antagonistic effect on the SERCA and is widely used to study Ca2+-signaling. The effect on SERCA has also been utilized in the treatment of solid tumors. A prodrug has been designed to target the blood vessels of cancer cells; the death of these blood vessels then leads to tumor necrosis. The first clinical trials of this drug were initiated in 2008, and the potent drug is expected to enter the market in the near future under the generic name Mipsagargin (G-202). This review will describe the discovery of the new drug, the on-going elucidation of the biosynthesis of thapsigargin in the plant and attempts to supply the global market with a novel potent anti-cancer drug.
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Review |
10 |
68 |
20
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Hegge AB, Andersen T, Melvik JE, Bruzell E, Kristensen S, Tønnesen HH. Formulation and bacterial phototoxicity of curcumin loaded alginate foams for wound treatment applications: studies on curcumin and curcuminoides XLII. J Pharm Sci 2010; 100:174-85. [PMID: 20575064 DOI: 10.1002/jps.22263] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2010] [Revised: 04/09/2010] [Accepted: 05/08/2010] [Indexed: 12/15/2022]
Abstract
Curcumin loaded alginate foams are proposed for application in antimicrobial photodynamic therapy of infected wounds. The drug loaded foams were formulated to provide a burst release of the photosensitizer when hydrated. The foams remained intact after hydration and would be possible to remove from the wound prior to irradiation without causing any tissue damage. The characterization of the prepared foams showed that both curcumin loaded and unloaded foams hydrated within 1 min and absorbed from 12 to 16 times their dry weight of a model physiological fluid. Curcumin, the model photosensitizer, has an extremely low solubility in water and may aggregate in aqueous environment. Cyclodextrins (CDs) and polyethylene glycol 400 (PEG 400) were therefore selected as solubilizers of curcumin in the foams to provide a burst release of the photosensitizer. Exposure to the prepared foams in combination with visible light irradiation (∼9.7 J/cm(2)) resulted in >6 log reduction of Entrococcus faecalis cells. However, curcumin mediated photokilling of Escherichia coli was ineffective when CDs were selected as solubilizer of curcumin in the foams. An 81% reduction in viable E. coli cells was detected after treatment with the foam containing PEG 400 as the only solubilizer of curcumin combined with visible light irradiation (∼29 J/cm(2)).
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Journal Article |
15 |
66 |
21
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Essendrop M, Andersen TB, Schibye B. Increase in spinal stability obtained at levels of intra-abdominal pressure and back muscle activity realistic to work situations. APPLIED ERGONOMICS 2002; 33:471-476. [PMID: 12236656 DOI: 10.1016/s0003-6870(02)00028-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In this study, sudden load was applied to the trunk and situations with alternating low levels of intra-abdominal pressure (IAP) realistic to work situations were compared. The aim was to see if IAP and the small increases in co-contraction of back muscles that follow are capable of increasing the stiffness of the lumbar spine. Nine subjects participated in ten sudden load situations during which they were asked to hold a box and conduct a percentage of maximal IAP. The hip was fixed and the load was applied horizontally on the trunk. EMG, IAP, and movement of the trunk were measured. It was found that IAP of a size likely to appear in work situations, and the concomitant increase in muscle co-activation increased the spine stiffness. This increase in stiffness decreased the movement caused by the sudden load. These results show that both abdominal- and back muscles may have an important role in stabilising the spine, and in decreasing movements caused by sudden loads likely to appear in numerous work
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23 |
51 |
22
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Echwald SM, Sørensen TD, Sørensen TI, Tybjaerg-Hansen A, Andersen T, Chung WK, Leibel RL, Pedersen O. Amino acid variants in the human leptin receptor: lack of association to juvenile onset obesity. Biochem Biophys Res Commun 1997; 233:248-52. [PMID: 9144432 DOI: 10.1006/bbrc.1997.6430] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The recently described putative lipostat system mediated in part by leptin and its hypothalamic receptor provides logical candidate genes for the molecular basis of inherited obesity in humans on the basis of the occurrence of profound obesity observed in obese and diabetic mice, in which the genes for leptin or its receptor, respectively, are mutated. In this study we tested the hypothesis that juvenile onset obesity in humans may be caused by leptin resistance mediated through genetic variations in isoforms of the hypothalamic leptin receptor. One hundred and fifty-six obese Danish men with a history of juvenile onset obesity were selected at the draft board examination with a body mass index (BMI) > or = 31 kg/m2. From the same study population a control group of 205 control subjects (mean BMI = 21,5 kg/m2) were randomly selected. Single strand conformational polymorphism scanning of genomic DNA from 56 obese subjects revealed a total of four amino acid variants located in coding exons 2, (Lys109Arg), 4 (Lys204Arg and Gln223Arg), and 12 (Lys656Asn), respectively. The codons 109, 223, and 656 variants were common, but their prevalence was not significantly different between obese and lean carriers with regard to allele or carrier frequency (p > 0.1 in each case). The codon 204 mutation was only found in one obese subject. In conclusion, it is unlikely that mutations in the coding region of the long isoform of the leptin receptor are a common cause of juvenile onset obesity.
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28 |
50 |
23
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Urhammer SA, Dalgaard LT, Sørensen TI, Møller AM, Andersen T, Tybjaerg-Hansen A, Hansen T, Clausen JO, Vestergaard H, Pedersen O. Mutational analysis of the coding region of the uncoupling protein 2 gene in obese NIDDM patients: impact of a common amino acid polymorphism on juvenile and maturity onset forms of obesity and insulin resistance. Diabetologia 1997; 40:1227-30. [PMID: 9349606 DOI: 10.1007/s001250050811] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Recently, a gene encoding a novel human uncoupling protein, designated UCP2, was discovered. The murine UCP2 was mapped to a region on mouse chromosome 7 which in several models has been shown to be linked to obesity and hyperinsulinaemia. Single strand conformation polymorphism (SSCP) analysis and direct sequencing of the coding region of the UCP2 gene in 35 obese Caucasian NIDDM patients of Danish ancestry revealed one nucleotide substitution, replacing an alanine with a valine at codon 55. The amino acid polymorphism was present in 24 of the 35 (69%) examined subjects. The allelic frequency of the A/V55 variant was 48.3% (95% CI: 42.5-54.1%) among 144 subjects with juvenile onset obesity, 45.6% (40.5-50.7%) among 182 subjects randomly selected at the draft board examination, and 45.5% (37.1-53.9%) among lean control subjects selected from the same study cohort. Within these cohorts there were no differences in BMI values at different ages among wild-type carriers and A/V55 carriers. In a population-based sample of 369 young healthy Caucasians the variant showed no association with alterations in BMI, waist-to-hip ratio, fat mass or weight gain during childhood or adolescence. The A/V55 polymorphism was not related to alterations in fasting values of serum insulin and C-peptide or to an impaired insulin sensitivity index. We conclude that genetic variability in the human UCP2 gene is not a common factor contributing to NIDDM in obese Danish Caucasian subjects and the common A/V55 amino acid polymorphism of the gene is not implicated in the pathogenesis of juvenile or maturity onset obesity or insulin resistance in Caucasians.
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Comparative Study |
28 |
49 |
24
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Olsen JO, Andersen T, Andersen N. Excitation of Li and Na in collisions with He and Ne: measurements of Li I and Na I resonance-line emission and polarization. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3700/10/9/021] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24 |
48 |
25
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Andersen T, McNair P, Hyldstrup L, Fogh-Andersen N, Nielsen TT, Astrup A, Transbøl I. Secondary hyperparathyroidism of morbid obesity regresses during weight reduction. Metabolism 1988; 37:425-8. [PMID: 3367788 DOI: 10.1016/0026-0495(88)90041-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In order to test the relation between obesity and the secondary hyperparathyroidism found in markedly overweight subjects, 24 morbidly obese patients were studied before and after a weight loss of 35.9 kg obtained by a nutritionally adequate, intermittent very-low-calorie diet. Overweight was reduced from 98 +/- 34% to 44 +/- 19%. Serum total calcium did not change, but serum ionized calcium (Ca2+) increased from 1.22 +/- 0.04 mmol/L to 1.25 +/- 0.04 mmol/L (P less than .001). A corresponding fall was observed in serum parathyroid hormone (s-PTH), which decreased from 47.2 +/- 21.7 pmol/L to 35.2 +/- 19.4 pmol/L (P = .01). The change of s-PTH was positively associated with the reduction of body weight (r = .50, P less than .05) and with the reduction of overweight (r = .55, P less than .01). Regarding calcium binding substances, serum albumin remained low. The initially lowered serum phosphate and bicarbonate both rose (P less than .001). Plasma lactate and plasma free fatty acids (FFAs) decreased (P less than .001). The study supports our hypothesis that the change profile of calcium complexing anions in obesity interferes with the tubular reabsorption of calcium, which in turn lowers serum Ca2+, thus promoting hyperparathyroidism. Along with weight loss, concentrations of calcium complexing anions returns towards normal values and the secondary hyperparathyroidism regresses.
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37 |
48 |