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1.
Fluids Barriers CNS ; 20(1): 54, 2023 Jul 06.
Article in English | MEDLINE | ID: mdl-37415175

ABSTRACT

BACKGROUND: Neurofilament light chain protein (NFL), a marker of neuronal axonal degeneration, is increased in cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). Assays for analysis of NFL in plasma are now widely available but plasma NFL has not been reported in iNPH patients. Our aim was to examine plasma NFL in iNPH patients and to evaluate the correlation between plasma and CSF levels, and whether NFL levels are associated with clinical symptoms and outcome after shunt surgery. METHODS: Fifty iNPH patients with median age 73 who had their symptoms assessed with the iNPH scale and plasma and CSF NFL sampled pre- and median 9 months post-operatively. CSF plasma was compared with 50 healthy controls (HC) matched for age and gender. Concentrations of NFL were determined in plasma using an in-house Simoa method and in CSF using a commercially available ELISA method. RESULTS: Plasma NFL was elevated in patients with iNPH compared to HC (iNPH: 45 (30-64) pg/mL; HC: 33 (26-50) (median; Q1-Q3), p = 0.029). Plasma and CSF NFL concentrations correlated in iNPH patients both pre- and postoperatively (r = 0.67 and 0.72, p < 0.001). We found only weak correlations between plasma or CSF NFL and clinical symptoms and no associations with outcome. A postoperative NFL increase was seen in CSF but not in plasma. CONCLUSIONS: Plasma NFL is increased in iNPH patients and concentrations correlate with CSF NFL implying that plasma NFL can be used to assess evidence of axonal degeneration in iNPH. This finding opens a window for plasma samples to be used in future studies of other biomarkers in iNPH. NFL is probably not a very useful marker of symptomatology or for prediction of outcome in iNPH.


Subject(s)
Hydrocephalus, Normal Pressure , Tumor Necrosis Factor Ligand Superfamily Member 14 , Humans , Aged , Hydrocephalus, Normal Pressure/cerebrospinal fluid , Intermediate Filaments , Neurofilament Proteins/cerebrospinal fluid , Biomarkers/cerebrospinal fluid
2.
Naunyn Schmiedebergs Arch Pharmacol ; 396(2): 247-260, 2023 02.
Article in English | MEDLINE | ID: mdl-36271936

ABSTRACT

Chemotherapy-induced intestinal mucositis is a severe side effect contributing to reduced quality of life and premature death in cancer patients. Despite a high incidence, a thorough mechanistic understanding of its pathophysiology and effective supportive therapies are lacking. The main objective of this rat study was to determine how 10 mg/kg doxorubicin, a common chemotherapeutic, affected jejunal function and morphology over time (6, 24, 72, or 168 h). The secondary objective was to determine if the type of dosing administration (intraperitoneal or intravenous) affected the severity of mucositis or plasma exposure of the doxorubicin. Morphology, proliferation and apoptosis, and jejunal permeability of mannitol were examined using histology, immunohistochemistry, and single-pass intestinal perfusion, respectively. Villus height was reduced by 40% after 72 h, preceded at 24 h by a 75% decrease in proliferation and a sixfold increase in apoptosis. Villus height recovered completely after 168 h. Mucosal permeability of mannitol decreased after 6, 24, and 168 h. There were no differences in intestinal injury or plasma exposure after intraperitoneal or intravenous doxorubicin dosing. This study provides an insight into the progression of chemotherapy-induced intestinal mucositis and associated cellular mucosal processes. Knowledge from this in vivo rat model can facilitate development of preventive and supportive therapies for cancer patients.


Subject(s)
Antineoplastic Agents , Mucositis , Neoplasms , Rats , Animals , Mucositis/chemically induced , Mucositis/drug therapy , Mucositis/pathology , Quality of Life , Doxorubicin , Neoplasms/drug therapy , Antineoplastic Agents/therapeutic use
3.
Eur J Pharm Biopharm ; 163: 240-251, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33872761

ABSTRACT

Accurate in vivo predictions of intestinal absorption of low solubility drugs require knowing their solubility in physiologically relevant dissolution media. Aspirated human intestinal fluids (HIF) are the gold standard, followed by simulated intestinal HIF in the fasted and fed state (FaSSIF/FeSSIF). However, current HIF characterization data vary, and there is also some controversy regarding the accuracy of FaSSIF and FeSSIF for predicting drug solubility in HIF. This study aimed at characterizing fasted and fed state duodenal HIF from 16 human volunteers with respect to pH, buffer capacity, osmolarity, surface tension, as well as protein, phospholipid, and bile salt content. The fasted and fed state HIF samples were further used to investigate the equilibrium solubility of 17 representative low-solubility small-molecule drugs, six of which were confidential industry compounds and 11 were known and characterized regarding chemical diversity. These solubility values were then compared to reported solubility values in fasted and fed state HIF, FaSSIF and FeSSIF, as well as with their human bioavailability for both states. The HIF compositions corresponded well to previously reported values and current FaSSIF and FeSSIF compositions. The drug solubility values in HIF (both fasted and fed states) were also well in line with reported solubility data for HIF, as well as simulated FaSSIF and FeSSIF. This indicates that the in vivo conditions in the proximal small intestine are well represented by simulated intestinal fluids in both composition and drug equilibrium solubility. However, increased drug solubility in the fed vs. fasted states in HIF did not correlate with the human bioavailability changes of the same drugs following oral administration in either state.


Subject(s)
Eating/physiology , Fasting/physiology , Intestinal Secretions/chemistry , Intestine, Small/metabolism , Pharmaceutical Preparations/chemistry , Administration, Oral , Biological Availability , Humans , Intestinal Absorption/physiology , Intestinal Secretions/metabolism , Solubility
4.
AJNR Am J Neuroradiol ; 41(7): 1187-1192, 2020 07.
Article in English | MEDLINE | ID: mdl-32527841

ABSTRACT

BACKGROUND AND PURPOSE: Ventricular enlargement in idiopathic normal pressure hydrocephalus is often estimated using the Evans index. However, the sensitivity of the Evans index to estimate changes in ventricular size postoperatively has been questioned. Here, we evaluated the postoperative change in ventricle size in relation to shunt response in patients with idiopathic normal pressure hydrocephalus, by comparing ventricular volume and the Evans index. MATERIALS AND METHODS: Fifty-seven patients with idiopathic normal pressure hydrocephalus underwent high-resolution MR imaging preoperatively and 6 months after shunt insertion. Clinical symptoms of gait, balance, cognition, and continence were assessed according to the idiopathic normal pressure hydrocephalus scale. The ventricular volume of the lateral and third ventricles and the Evans index were measured using ITK-SNAP software. Semiautomatic volumetric analysis was performed, and postoperative changes in ventricular volume and the Evans index and their relationships to postoperative clinical improvement were compared. RESULTS: The median postoperative ventricular volume decrease was 25 mL (P < .001). The proportional decrease in ventricular volume was greater than that in the Evans index (P < .001). The postoperative decrease in ventricular volume was associated with a postoperative increase in the idiopathic normal pressure hydrocephalus scale score (P = .004). Shunt responders (75%) demonstrated a greater ventricular volume decrease than nonresponders (P = .002). CONCLUSIONS: Clinical improvement after shunt surgery in idiopathic normal pressure hydrocephalus is associated with a reduction of ventricular size. Ventricular volume is a more sensitive estimate than the Evans index and, therefore, constitutes a more precise method to evaluate change in ventricle size after shunt treatment in idiopathic normal pressure hydrocephalus.


Subject(s)
Cerebral Ventricles/diagnostic imaging , Hydrocephalus, Normal Pressure/surgery , Neuroimaging/methods , Treatment Outcome , Aged , Aged, 80 and over , Cerebrospinal Fluid Shunts , Female , Humans , Male , Middle Aged
5.
Article in English | MEDLINE | ID: mdl-31594647

ABSTRACT

By administering an anaerobic cultivated human intestinal microbiota (ACHIM) via upper gastrointestinal route using endoscopy we aimed to rectify intestinal dysbiosis and simultaneously achieve a treatment response in IBS patients. The study population fulfilled the Rome III IBS criteria and comprised 50 patients. During 10 days, patients recorded the irritable bowel syndrome symptom severity scale (IBS-SSS) along with the Bristol stool scale and number of stools/day. The enrolled patients were categorized as follows: 37 with diarrhea, 5 with constipation and 8 with mixed symptoms. The treatment response showed reduction in a majority of patients, 32 of which with 50-point reduction of IBS-SSS and 21 with a 100-point IBS-SSS reduction. The percentage improvement was 36 (23-49) and 28 (18-38) for women and men respectively. Short-chain fatty acids were not changed. We consider fecal microbiota transplantation in the form of ACHIM as an option for the future therapeutic armamentarium in IBS. REGISTERED TRIAL: www.clinicaltrials.gov NCT02857257.


Subject(s)
Fecal Microbiota Transplantation/methods , Gastrointestinal Microbiome/physiology , Irritable Bowel Syndrome/therapy , Adult , Female , Humans , Irritable Bowel Syndrome/pathology , Male , Middle Aged
6.
AJNR Am J Neuroradiol ; 40(1): 74-79, 2019 01.
Article in English | MEDLINE | ID: mdl-30523139

ABSTRACT

BACKGROUND AND PURPOSE: Several studies have evaluated the use of MR imaging markers for the prediction of outcome after shunt surgery in idiopathic normal pressure hydrocephalus with conflicting results. Our aim was to investigate the predictive value of a number of earlier proposed morphologic MR imaging markers in a large group of patients with idiopathic normal pressure hydrocephalus. MATERIALS AND METHODS: One hundred sixty-eight patients (mean age, 70 ± 9.3 years) with idiopathic normal pressure hydrocephalus, subjected to standardized quantification of clinical symptoms before and after shunt surgery, were included in the study. Outcome was calculated using a composite score. Preoperative T1, FLAIR, and flow-sensitive images were analyzed regarding the presence of 13 different morphologic MR imaging markers. RESULTS: The median Evans index was 0.41 (interquartile range, 0.37-0.44). All patients had an aqueductal flow void sign present and white matter hyperintensities. The median callosal angle was 68.8° (interquartile range, 57.7°-80.8°). Dilated Sylvian fissures were found in 69%; focally dilated sulci, in 25%; and widening of the interhemispheric fissure, in 55%. Obliteration of the sulci at the convexity was found in 36%, and 36% of patients were characterized as having disproportionately enlarged subarachnoid space hydrocephalus. Sixty-eight percent of patients improved after surgery. None of the investigated MR imaging markers were significant predictors of improvement after shunt surgery. CONCLUSIONS: Disproportionately enlarged subarachnoid space hydrocephalus, a small callosal angle, and the other MR imaging markers evaluated in this study should not be used to exclude patients from shunt surgery. These markers, though they may be indicative of idiopathic normal pressure hydrocephalus, do not seem to be a part of the mechanisms connected to the reversibility of the syndrome.


Subject(s)
Cerebrospinal Fluid Shunts/methods , Hydrocephalus, Normal Pressure/diagnostic imaging , Hydrocephalus, Normal Pressure/pathology , Hydrocephalus, Normal Pressure/surgery , Patient Selection , Aged , Corpus Callosum/diagnostic imaging , Corpus Callosum/pathology , Female , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Subarachnoid Space/diagnostic imaging , Subarachnoid Space/pathology
7.
Acta Anaesthesiol Scand ; 62(5): 620-627, 2018 May.
Article in English | MEDLINE | ID: mdl-29377065

ABSTRACT

BACKGROUND: Pre-operative complex carbohydrate (CHO) drinks are recommended to attenuate post-operative insulin resistance. However, many institutions use simple CHO drinks, which while convenient, may have less metabolic effects. Whey protein may enhance insulin release when added to complex CHO. The aim of this study was to compare the insulin response to simple CHO vs. simple CHO supplemented with whey protein. METHODS: Twelve healthy volunteers participated in this double-blinded, within subject, cross-over design study investigating insulin response to simple CHO drink vs. simple CHO + whey (CHO + W) drink. The primary outcome was the accumulated insulin response during 180 min after ingestion of the drinks (Area under the curve, AUC). Secondary outcomes included plasma glucose and ghrelin levels, and gastric emptying rate estimated by acetaminophen absorption technique. Data presented as mean (SD). RESULTS: There was no differences in accumulated insulin response after the CHO or CHO + W drinks [AUC: 15 (8) vs. 20 (14) nmol/l, P = 0.27]. Insulin and glucose levels peaked between 30 and 60 min and reached 215 (95) pmol/l and 7 (1) mmol/l after the CHO drink and to 264 (232) pmol/l and 6.5 (1) mmol/l after the CHO + W drink. There were no differences in glucose or ghrelin levels or gastric emptying with the addition of whey. CONCLUSION: The addition of whey protein to a simple CHO drink did not change the insulin response in healthy individuals. The peak insulin responses to simple CHO with or without whey protein were lower than that previously reported with complex CHO drinks. The impact of simple carbohydrate drinks with lower insulin response on peri-operative insulin sensitivity requires further study.


Subject(s)
Blood Glucose/analysis , Dietary Carbohydrates/administration & dosage , Insulin/blood , Whey Proteins/administration & dosage , Adult , Aged , Cross-Over Studies , Double-Blind Method , Gastric Emptying , Ghrelin/blood , Humans , Middle Aged
8.
Aliment Pharmacol Ther ; 47(3): 391-400, 2018 02.
Article in English | MEDLINE | ID: mdl-29210098

ABSTRACT

BACKGROUND: The wireless motility capsule concurrently measures temperature, pH and pressure as it traverses the gastrointestinal tract. AIMS: To describe normative values for motility/contractility parameters across age, gender and testing centres. METHODS: Healthy participants underwent a standardised wireless motility capsule assessment following an overnight fast and consumption of a meal of known nutritional content. Traces were divided into regions of interest and analysed using 2 software packages (MotiliGI and GIMS Data Viewer). Inter-observer agreement was independently assessed by 2 investigators. RESULTS: Normative data for motility/contractility parameters (maximum amplitude, mean peak amplitude, contraction frequency and motility index) are presented for 107 individuals (62 male, median age 40 years, range 18-78). MotiliGI-Gastric, small bowel and colonic maximal contraction amplitude correlated with age (r = .24, P = .01; r = .22, P = .02; and r = .2, P = .04 respectively). Small bowel motility index was higher in females than males (150.4 ± 12 vs 122 ± 7.6, P = .04). Inter-observer agreement was excellent for transit times, pH and contractility/motility parameters. GIMS Data viewer-Gastric, small bowel and colonic loge motility index correlated with the respective area under the contraction curve, total contractions, sum of amplitudes and contraction frequency (all r>.35, P < .0003) but not with transit times. CONCLUSIONS: Our analysis provides normative data for motility/contractility parameters. Log motility index summarises a number of measures. In future, the measurement of contractile activity with the wireless motility capsule may potentially aid in the diagnosis of disease states such as visceral myopathic disorders.


Subject(s)
Capsule Endoscopy , Gastrointestinal Motility/physiology , Gastrointestinal Tract/diagnostic imaging , Gastrointestinal Transit/physiology , Adolescent , Adult , Age Factors , Aged , Female , Gastrointestinal Tract/pathology , Gastrointestinal Tract/physiology , Geography , Healthy Volunteers , Humans , Male , Middle Aged , Observer Variation , Reproducibility of Results , Sex Factors , Wireless Technology , Young Adult
9.
Acta Physiol (Oxf) ; 222(2)2018 02.
Article in English | MEDLINE | ID: mdl-28786555

ABSTRACT

AIM: Stomach contractions show two types of specific patterns in many species, that is migrating motor contraction (MMC) and postprandial contractions (PPCs), in the fasting and fed states respectively. We found gastric PPCs terminated with migrating strong contractions in humans, dogs and suncus. In this study, we reveal the detailed characteristics and physiological implications of these strong contractions of PPC. METHODS: Human, suncus and canine gastric contractions were recorded with a motility-monitoring ingestible capsule and a strain-gauge force transducer. The response of motilin and ghrelin and its receptor antagonist on the contractions were studied by using free-moving suncus. RESULTS: Strong gastric contractions were observed at the end of a PPC in human, dog and suncus models, and we tentatively designated this contraction to be a postprandial giant contraction (PPGC). In the suncus, the PPGC showed the same property as those of a phase III contraction of MMC (PIII-MMC) in the duration, motility index and response to motilin or ghrelin antagonist administration. Ghrelin antagonist administration in the latter half of the PPC (LH-PPC) attenuated gastric contraction prolonged the duration of occurrence of PPGC, as found in PII-MMC. CONCLUSION: It is thought that the first half of the PPC changed to PII-MMC and then terminated with PIII-MMC, suggesting that PPC consists of a digestive phase (the first half of the PPC) and a discharge phase (LH-PPC) and that LH-PPC is coincident with MMC. In this study, we propose a new approach for the understanding of postprandial contractions.


Subject(s)
Gastrointestinal Motility/physiology , Ghrelin/metabolism , Motilin/metabolism , Postprandial Period/physiology , Shrews/physiology , Animals , Dogs , Humans , Muscle Contraction/physiology , Stomach/physiology
10.
Neurogastroenterol Motil ; 29(10): 1-9, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28524600

ABSTRACT

BACKGROUND: There is interest in ultimately combining endoscopy and motility assessments. Gastric emptying (GET), small bowel (SBTT), colon (CTT) and whole gut transit (WGTT) times are conveniently obtained by SmartPill® wireless motility capsule (WMC) that records luminal pH, temperature and pressure. Reproducibility within same subjects and accuracy of software derived times (MotiliGI® ) were investigated for diagnostic application. GET and SBTT were separately measured using video capsule endoscopy (VCE). The aim of this investigation was to assess same subject reproducibility of WMC, accuracy of software derived transit times and relate to Pillcam® SB (small bowel) VCE motility data. METHODS: Seventy three healthy adults ingested a 260 kcal mixed meal followed by WMC tests. Food intake was permitted after 6 hours. Regional transit data was obtained for GET, SBTT and CTT, the sum yielding WGTT. Nineteen subjects repeated WMC tests 2 or 4 weeks later; a separate 70 underwent VCE while fasted. KEY RESULTS: Visually derived data from WMC yielded GET 3.46±0.27, SBTT 5.15±0.21, CTT 20.76±1.19 and WGTT 29.53±1.28 hours (mean±SEM). Pearson's correlation coefficients (r) against software derived results were: GET 0.78 (P<.0001), SBTT 0.28 (P<.05), CTT 0.96 (P<.0001), WGTT 0.99 (P<.0001). VCE yielded lower GET (0.71±0.08 hours) and SBTT (4.15±0.13 hours). CONCLUSIONS AND INFERENCES: GET, SBTT, CTT and WGTT obtained by WMC are commensurate with literature values, including by other methods. Visually and software derived transit times have strongest correlations for CTT and WGTT. WMC yields longer GET and SBTT than VCE, perhaps due to meal related effects on motility.


Subject(s)
Capsule Endoscopy/instrumentation , Gastrointestinal Transit , Software , Adult , Aged , Female , Gastrointestinal Motility , Humans , Male , Middle Aged , Reproducibility of Results , Young Adult
11.
Oecologia ; 182(2): 511-8, 2016 10.
Article in English | MEDLINE | ID: mdl-27209296

ABSTRACT

Predation is an ecologically important process, and intra-guild interactions may substantially influence the ecological effects of predator species. Despite a rapid expansion in the use of mathematical graph theory to describe trophic relations, network approaches have rarely been used to study interactions within predator assemblages. Assemblages of diurnal raptors are subject to substantial intra- and interspecific competition. Here we used the novel approach of applying analyzes based on network topology to species-specific data on the stable isotopes (13)C and (15)N in feathers to evaluate patterns of relative resource utilization within a guild of diurnal raptors in northern Sweden. Our guild consisted of the golden eagle (Aquila chrysaetos), the gyrfalcon (Falco rusticolus), the peregrine falcon (Falco peregrinus) and the rough-legged buzzard (Buteo lagopus). We found a modular trophic interaction structure within the guild, but the interactions were less nested than expected by chance. These results suggest low redundancy and hence a strong ecological importance of individual species. Our data also suggested that species were less connected through intra-guild interactions than expected by chance. We interpret our results as a convergence on specific isotope niches, and that body size and different hunting behaviour may mediate competition within these niches. We finally highlight that generalist predators could be ecologically important by linking specialist predator species with disparate dietary niches.


Subject(s)
Feathers/chemistry , Raptors , Animals , Falconiformes , Isotopes , Predatory Behavior
12.
Aliment Pharmacol Ther ; 42(6): 761-72, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26223837

ABSTRACT

BACKGROUND: The wireless motility capsule (WMC) offers the ability to investigate luminal gastrointestinal (GI) physiology in a minimally invasive manner. AIM: To investigate the effect of testing protocol, gender, age and study country on regional GI transit times and associated pH values using the WMC. METHODS: Regional GI transit times and pH values were determined in 215 healthy volunteers from USA and Sweden studied using the WMC over a 6.5-year period. The effects of test protocol, gender, age and study country were examined. RESULTS: For GI transit times, testing protocol was associated with differences in gastric emptying time (GET; shorter with protocol 2 (motility capsule ingested immediately after meal) vs. protocol 1 (motility capsule immediately before): median difference: 52 min, P = 0.0063) and colonic transit time (CTT; longer with protocol 2: median 140 min, P = 0.0189), but had no overall effect on whole gut transit time. Females had longer GET (by median 17 min, P = 0.0307), and also longer CTT by (104 min, P = 0.0285) and whole gut transit time by (263 min, P = 0.0077). Increasing age was associated with shorter small bowel transit time (P = 0.002), and study country also influenced small bowel and CTTs. Whole gut and CTTs showed clustering of data at values separated by 24 h, suggesting that describing these measures as continuous variables is invalid. Testing protocol, gender and study country also significantly influenced pH values. CONCLUSIONS: Regional GI transit times and pH values, delineated using the wireless motility capsule (WMC), vary based on testing protocol, gender, age and country. Standardisation of testing is crucial for cross-referencing in clinical practice and future research.


Subject(s)
Capsule Endoscopy/methods , Clinical Protocols , Gastric Emptying/physiology , Gastrointestinal Transit/physiology , Hydrogen-Ion Concentration , Adult , Age Factors , Female , Healthy Volunteers , Humans , Male , Middle Aged , Sex Factors , Sweden , Time Factors , United States
13.
Acta Physiol (Oxf) ; 215(2): 105-18, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26176347

ABSTRACT

AIM: The migrating motor complex (MMC) propels contents through the gastrointestinal tract during fasting. Nitric oxide (NO) is an inhibitory neurotransmitter in the gastrointestinal tract. Little is known about how NO regulates the MMC. In this study, the aim was to examine nitrergic inhibition of the MMC in man using N(G)-monomethyl-L-arginine (L-NMMA) in combination with muscarinic receptor antagonist atropine and 5-HT3 receptor antagonist ondansetron. METHODS: Twenty-six healthy volunteers underwent antroduodenojejunal manometry for 8 h with saline or NO synthase (NOS) inhibitor L-NMMA randomly injected I.V. at 4 h with or without atropine or ondansetron. Plasma ghrelin, motilin and somatostatin were measured by ELISA. Intestinal muscle strip contractions were investigated for NO-dependent mechanisms using L-NMMA and tetrodotoxin. NOS expression was localized by immunohistochemistry. RESULTS: L-NMMA elicited premature duodenojejunal phase III in all subjects but one, irrespective of atropine or ondansetron. L-NMMA shortened MMC cycle length, suppressed phase I and shifted motility towards phase II. Pre-treatment with atropine extended phase II, while ondansetron had no effect. L-NMMA did not change circulating ghrelin, motilin or somatostatin. Intestinal contractions were stimulated by L-NMMA, insensitive to tetrodotoxin. NOS immunoreactivity was detected in the myenteric plexus but not in smooth muscle cells. CONCLUSION: Nitric oxide suppresses phase III of MMC independent of muscarinic and 5-HT3 receptors as shown by nitrergic blockade, and acts through a neurocrine disinhibition step resulting in stimulated phase III of MMC independent of cholinergic or 5-HT3 -ergic mechanisms. Furthermore, phase II of MMC is governed by inhibitory nitrergic and excitatory cholinergic, but not 5-HT3 -ergic mechanisms.


Subject(s)
Muscarinic Antagonists/pharmacology , Muscle, Smooth/drug effects , Myoelectric Complex, Migrating/drug effects , Nitric Oxide/metabolism , Serotonin Receptor Agonists/pharmacology , omega-N-Methylarginine/pharmacology , Adult , Atropine/pharmacology , Female , Gastrointestinal Motility/drug effects , Humans , Male , Muscle Contraction/drug effects , Myoelectric Complex, Migrating/physiology , Nitric Oxide Synthase/antagonists & inhibitors , Receptors, Muscarinic/metabolism , Serotonergic Neurons/drug effects , Treatment Outcome , Young Adult
14.
Oecologia ; 174(4): 1241-54, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24448699

ABSTRACT

The functional response is a key element of predator-prey interactions. Basic functional response theory explains foraging behavior of individual predators, but many empirical studies of free-ranging predators have estimated functional responses by using population-averaged data. We used a novel approach to investigate functional responses of an avian predator (the rough legged-buzzard Buteo lagopus Pontoppidan, 1763) to intra-annual spatial variation in rodent density in subarctic Sweden, using breeding pairs as the sampling unit. The rough-legged buzzards responded functionally to Norwegian lemmings (Lemmus lemmus L. 1758), grey-sided voles (Myodes rufocanus Sundevall, 1846) and field voles (Microtus agrestis L. 1761), but different rodent prey were not utilised according to relative abundance. The functional response to Norwegian lemmings was a steep type II curve and a more shallow type III response to grey-sided voles. The different shapes of these two functional responses were likely due to combined effects of differences between lemmings and grey-sided voles in habitat utilisation, anti-predator behaviour and size-dependent vulnerability to predation. Diet composition changed less than changes in relative prey abundance, indicating negative switching, with high disproportional use of especially lemmings at low relative densities. Our results suggest that lemmings and voles should be treated separately in future empirical and theoretical studies in order to better understand the role of predation in this study system.


Subject(s)
Arvicolinae , Falconiformes/physiology , Predatory Behavior/physiology , Animals , Appetitive Behavior , Diet , Ecosystem , Models, Theoretical , Sweden
15.
Eur J Clin Nutr ; 68(5): 581-6, 2014 May.
Article in English | MEDLINE | ID: mdl-24398647

ABSTRACT

BACKGROUND/OBJECTIVES: A decline in resting energy expenditure (REE) beyond that predicted from changes in body composition has been noted following dietary-induced weight loss. However, it is unknown whether a compensatory downregulation in REE also accompanies exercise (EX)-induced weight loss, or whether this adaptive metabolic response influences energy intake (EI). SUBJECTS/METHODS: Thirty overweight and obese women (body mass index (BMI)=30.6±3.6 kg/m(2)) completed 12 weeks of supervised aerobic EX. Body composition, metabolism, EI and metabolic-related hormones were measured at baseline, week 6 and post intervention. The metabolic adaptation (MA), that is, difference between predicted and measured REE was also calculated post intervention (MApost), with REE predicted using a regression equation generated in an independent sample of 66 overweight and obese women (BMI=31.0±3.9 kg/m(2)). RESULTS: Although mean predicted and measured REE did not differ post intervention, 43% of participants experienced a greater-than-expected decline in REE (-102.9±77.5 kcal per day). MApost was associated with the change in leptin (r=0.47; P=0.04), and the change in resting fat (r=0.52; P=0.01) and carbohydrate oxidation (r=-0.44; P=0.02). Furthermore, MApost was also associated with the change in EI following EX (r=-0.44; P=0.01). CONCLUSIONS: Marked variability existed in the adaptive metabolic response to EX. Importantly, those who experienced a downregulation in REE also experienced an upregulation in EI, indicating that the adaptive metabolic response to EX influences both physiological and behavioural components of energy balance.


Subject(s)
Body Composition , Energy Intake , Energy Metabolism , Exercise/physiology , Weight Loss , Adult , Blood Glucose , Body Mass Index , Female , Humans , Leptin/blood , Linear Models , Middle Aged , Nutrition Assessment , Obesity/therapy , Overweight/therapy , Rest , Surveys and Questionnaires
16.
Neurogastroenterol Motil ; 25(6): 474-80, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23527561

ABSTRACT

BACKGROUND: Ghrelin has been shown to stimulate gastric emptying in healthy humans and patients with delayed gastric emptying. The aim of this study is to assess the effect of ghrelin on gastric emptying on day 2 after open colorectal surgery. METHODS: Twenty-four patients (mean age 69.2 ± 1.4, BMI 25.8 ± 0.8 kg m(-2) ) were randomized to saline or ghrelin infusion (15 pmol kg(-1)  min(-1) ) during 3 h before and on day 2 after open colorectal surgery. Of these, 20 were assessed both before and after surgery. At start of infusion, a liquid meal (480 kcal, 200 mL) was administered together with 1.5 g acetaminophen. Plasma was obtained at regular intervals together with visual analogue scales for hunger, satiety and nausea. Acetaminophen was analyzed as a marker of gastric emptying. Plasma glucose, insulin, acyl-ghrelin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinoptrophic peptide (GIP), pancreatic polypeptide and peptide YY (PYY) were analyzed. KEY RESULTS: Gastric emptying was faster during ghrelin infusion compared to saline before and after surgery (P < 0.02). In addition, plasma glucose was increased (P < 0.05). With ghrelin infusion, plasma insulin was unchanged except for lower values postoperatively (P < 0.05). Ghrelin did not alter plasma concentrations of gut peptides. After surgery, ghrelin shortened the time to first bowel movement compared to saline (2.1 ± 0.3 vs 3.5 ± 0.4 days, P = 0.02). CONCLUSIONS & INFERENCES: A 3-h ghrelin infusion increased the gastric emptying rate and hastened the time to first bowel movement after surgery. Ghrelin/ghrelin receptor agonists have a therapeutic potential in postoperative ileus; Karolinska Clinical Trial Registry nr CT20110084.


Subject(s)
Defecation/drug effects , Gastric Emptying/drug effects , Ghrelin/pharmacology , Hunger/drug effects , Satiation/drug effects , Administration, Intravenous , Aged , Blood Glucose , Double-Blind Method , Female , Ghrelin/blood , Glucagon/blood , Glucagon-Like Peptide 1/blood , Humans , Insulin/blood , Male , Peptide YY/blood , Postoperative Period , Treatment Outcome
17.
Neurogastroenterol Motil ; 25(2): e140-50, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23279217

ABSTRACT

BACKGROUND: Gastroparesis causes significant morbidity and treatment options are limited. TZP-102 a novel, macrocyclic, selective, oral ghrelin receptor agonist, was evaluated in a randomized, double-blind, placebo-controlled trial in patients with diabetic gastroparesis. METHODS: A total of 92 outpatients were randomized to once-daily administrations of 10-mg (n = 22), 20-mg (n = 21), 40-mg (n = 23) TZP-102 or placebo (n = 26). The primary endpoint was the change from baseline in gastric half-emptying time (T(½)) utilizing (13)C-breath test methodology and secondary endpoints included symptom improvement using patient-reported gastroparesis symptom scores (PAGI-SYM questionnaire) and patient and physician overall treatment evaluations (OTE). KEY RESULTS: Gastric T½ changes were not statistically significant between TZP-102 and placebo after 28 days of treatment at any dose. Clinical improvements (-1.0 to -1.4 point mean decrease in symptom severity) occurred in the Gastroparesis Cardinal Symptom Index (GCSI) component of the PAGI-SYM, which was significant vs placebo for all TZP-102 doses combined. Improvements became evident after 1 week of treatment. Significantly, more patients given TZP-102 (any dose) had a 50% reduction in baseline GCSI score (28.8%vs 7.7% placebo). Safety profiles were similar across groups. All TZP-102 doses were well-tolerated with no adverse cardiac, weight, or glucose control outcomes. CONCLUSIONS & INFERENCES: TZP-102 for 28 days, at doses of 10-40 mg once daily, was well-tolerated and resulted in a reduction in symptoms of gastroparesis. The lack of correlation between symptom improvement and gastric emptying change is consistent with previous studies in diabetic gastroparesis, and emphasizes the value of patient-defined outcomes in determining therapeutic benefit.


Subject(s)
Diabetes Complications/drug therapy , Gastroparesis/drug therapy , Macrocyclic Compounds/administration & dosage , Receptors, Ghrelin/agonists , Adult , Aged , Dose-Response Relationship, Drug , Double-Blind Method , Female , Gastric Emptying/drug effects , Gastroparesis/etiology , Humans , Macrocyclic Compounds/adverse effects , Male , Middle Aged , Young Adult
18.
Acta Physiol (Oxf) ; 207(2): 326-36, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23009282

ABSTRACT

AIM: To compare the therapeutic effect of α(2) and α(4) integrin-blocking antibodies to conventional inflammatory bowel disease drugs methotrexate, 5-aminosalicylic acid and azathioprine in the dextran sulphate sodium mouse colitis model. METHODS: Colitis was induced in balb/c mice with 2.5-3.0% dextran sulphate sodium. Treatment was given daily for 7 days after the onset of colitis, by rectal installation. Clinical signs of disease were assessed daily using a disease activity index. After 19 days, all animals were killed and colon samples collected for histological grading and mRNA/protein analysis. All treatment groups were compared with an untreated control group and a treatment group receiving dextran sulphate sodium alone to monitor the potential degree of clinical remission. RESULTS: Treatment with anti-α(2) antibodies and methotrexate reduced the body weight loss. At the end of treatment, anti-α(2) antibodies reduced rectal bleeding, while methotrexate reduced the disease activity index score. Histological evaluation showed that anti-α(2) antibodies, methotrexate, 5-aminosalicylic acid and azathioprine treatment reduced the acute inflammation; methotrexate was the only treatment with effect on the crypt score. Compared with the dextran sulphate sodium alone group, the methotrexate group showed down-regulation of IL-1ß at the mRNA level, while the anti-α(2) antibody group displayed decreased protein expression of iNOS and IL-1ß. CONCLUSIONS: Specific blocking of extravascular trafficking of leucocytes with α(2)-antibodies could be a new beneficial drug target in inflammatory bowel disease.


Subject(s)
Antibodies, Blocking/pharmacology , Colitis/drug therapy , Integrin alpha2/metabolism , Integrin alpha4/metabolism , Animals , Anti-Inflammatory Agents/pharmacology , Antibodies, Monoclonal/pharmacology , Blotting, Western , Colitis/pathology , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Female , Mice , Mice, Inbred BALB C , Real-Time Polymerase Chain Reaction
19.
Regul Pept ; 180: 12-6, 2013 Jan 10.
Article in English | MEDLINE | ID: mdl-23159451

ABSTRACT

BACKGROUND: In animal and human studies glucagon-like peptide-2 (GLP-2) has been shown to increase blood flow in the superior mesenteric artery and the portal vein. This study describes the effect of GLP-2 measured directly on the intestinal mucosal blood flow by laser Doppler flowmetry (LDF) in end-jejunostomy short bowel syndrome (SBS) patients. METHODS: In five SBS patients with end-jejunostomy a specially designed laser Doppler probe was inserted into the stoma nipple, and blood flow measured directly on the jejunal mucosa for 105 min in relation to no treatment, systemic saline infusion, topical adrenaline application and a subcutaneous injection of 800 µg native GLP-2. RESULTS: The GLP-2 injection increased jejunal mucosal blood flow by 79±37% compared to conditions, where no treatment was given (p<0.001). The significant effect was present at least 105 min. Systemic saline infusion and topical, mucosal adrenaline application did not affect mucosal microcirculation. CONCLUSIONS: GLP-2 raises jejunal microcirculation in SBS patients with end-jejunostomy. This may explain the redness and increase in the end-jejunostomy nipple size imminently after commencing GLP-2 injections. The potential beneficial effects of this GLP-2-mediated increase of blood flow in the mesenteric bed should be investigated in clinical conditions other than the short bowel syndrome.


Subject(s)
Glucagon-Like Peptide 2/physiology , Intestinal Mucosa/blood supply , Jejunum/physiopathology , Microcirculation/physiology , Short Bowel Syndrome/physiopathology , Aged , Aged, 80 and over , Female , Humans , Jejunum/surgery , Laser-Doppler Flowmetry , Male , Middle Aged , Pilot Projects , Short Bowel Syndrome/surgery
20.
Regul Pept ; 179(1-3): 71-6, 2012 Nov 10.
Article in English | MEDLINE | ID: mdl-22960405

ABSTRACT

BACKGROUND: ROSE-010, a Glucagon-Like Peptide-1 (GLP-1) analog, reduces gastrointestinal motility and relieves acute pain in patients with irritable bowel syndrome (IBS). The rat small bowel migrating myoelectric complex (MMC) is a reliable model of pharmacological effects on gastrointestinal motility. Accordingly, we investigated whether ROSE-010 works through GLP-1 receptors in gut musculature and its effectiveness when administered by pulmonary inhalation. MATERIALS AND METHODS: Rats were implanted with bipolar electrodes at 5, 15 and 25 cm distal to pylorus and myoelectric activity was recorded. First, intravenous or subcutaneous injections of ROSE-010 or GLP-1 (1, 10, 100 µg/kg) with or without the GLP-1 receptor blocker exendin(9-39)amide (300 µg/kg·h), were studied. Second, ROSE-010 (100, 200 µg/kg) Technosphere® powder was studied by inhalation. RESULTS: The baseline MMC cycle length was 17.5±0.8 min. GLP-1 and ROSE-010, administered intravenously or subcutaneously, significantly inhibited myoelectric activity and prolonged MMC cycling; 100 µg/kg completely inhibited spiking activity for 49.1±4.2 and 73.3±7.7 min, while the MMC cycle length increased to 131.1±11.4 and 149.3±15.5 min, respectively. Effects of both drugs were inhibited by exendin(9-39)amide. Insufflation of ROSE-010 (100, 200 µg/kg) powder formulation totally inhibited myoelectric spiking for 52.6±5.8 and 70.1±5.4 min, and increased MMC cycle length to 102.6±18.3 and 105.9±9.5 min, respectively. CONCLUSIONS: Pulmonary delivery of ROSE-010 inhibits gut motility through the GLP-1R similar to natural GLP-1. ROSE-010 causes receptor-mediated inhibition of MMC comparable to that of intravenous or subcutaneous administration. This suggests that ROSE-010 administered as a Technosphere® inhalation powder has potential in IBS pain management and treatment.


Subject(s)
Glucagon-Like Peptide 1/analogs & derivatives , Myoelectric Complex, Migrating/drug effects , Peptide Fragments/administration & dosage , Peptide Fragments/pharmacology , Receptors, Glucagon/antagonists & inhibitors , Administration, Inhalation , Administration, Intravenous , Animals , Consciousness , Drug Evaluation, Preclinical , Electrodes, Implanted , Gastrointestinal Motility/drug effects , Glucagon-Like Peptide 1/administration & dosage , Glucagon-Like Peptide 1/pharmacology , Glucagon-Like Peptide-1 Receptor , Injections, Subcutaneous , Intestine, Small/drug effects , Intestine, Small/metabolism , Irritable Bowel Syndrome/metabolism , Male , Rats , Rats, Sprague-Dawley , Receptors, Glucagon/metabolism , Statistics, Nonparametric , Time Factors
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