Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
19
result(s) for
"Thomsen, Lars Lykke"
Sort by:
Expression of Iron-Related Proteins at the Neurovascular Unit Supports Reduction and Reoxidation of Iron for Transport Through the Blood-Brain Barrier
by
Thomsen, Lars Lykke
,
Burkhart, Annette
,
Thomsen, Louiza Bohn
in
Animals
,
Astrocytes - metabolism
,
Biological Transport
2016
The mechanisms for iron transport through the blood-brain barrier (BBB) remain a controversy. We analyzed for expression of mRNA and proteins involved in oxidation and transport of iron in isolated brain capillaries from dietary normal, iron-deficient, and iron-reverted rats. The expression was also investigated in isolated rat brain endothelial cells (RBECs) and in immortalized rat brain endothelial (RBE4) cells grown as monoculture or in hanging culture inserts with defined BBB properties. Transferrin receptor 1, ferrireductases Steap 2 and 3, divalent metal transporter 1 (DMT1), ferroportin, soluble and glycosylphosphatidylinositol (GPI)-anchored ceruloplasmin, and hephaestin were all expressed in brain capillaries in vivo and in isolated RBECs and RBE4 cells. Gene expression of DMT1, ferroportin, and soluble and GPI-anchored ceruloplasmin were significantly higher in isolated RBECs with induced BBB properties. Primary pericytes and astrocytes both expressed ceruloplasmin and hephaestin, and RBECs, pericytes, and astrocytes all exhibited ferrous oxidase activity. The coherent protein expression of these genes was demonstrated by immunocytochemistry. The data show that brain endothelial cells provide the machinery for receptor-mediated uptake of ferric iron-containing transferrin. Ferric iron can then undergo reduction to ferrous iron by ferrireductases inside endosomes followed by DMT1-mediated pumping into the cytosol and subsequently cellular export by ferroportin. The expression of soluble ceruloplasmin by brain endothelial cells, pericytes, and astrocytes that together form the neurovascular unit (NVU) provides the ferroxidase activity necessary to reoxidize ferrous iron once released inside the brain.
Journal Article
Impairment of the Developing Human Brain in Iron Deficiency: Correlations to Findings in Experimental Animals and Prospects for Early Intervention Therapy
2019
Due to the necessity of iron for a variety of cellular functions, the developing mammalian organism is vulnerable to iron deficiency, hence causing structural abnormalities and physiological malfunctioning in organs, which are particularly dependent on adequate iron stores, such as the brain. In early embryonic life, iron is already needed for proper development of the brain with the proliferation, migration, and differentiation of neuro-progenitor cells. This is underpinned by the widespread expression of transferrin receptors in the developing brain, which, in later life, is restricted to cells of the blood–brain and blood–cerebrospinal fluid barriers and neuronal cells, hence ensuring a sustained iron supply to the brain, even in the fully developed brain. In embryonic human life, iron deficiency is thought to result in a lower brain weight, with the impaired formation of myelin. Studies of fully developed infants that have experienced iron deficiency during development reveal the chronic and irreversible impairment of cognitive, memory, and motor skills, indicating widespread effects on the human brain. This review highlights the major findings of recent decades on the effects of gestational and lactational iron deficiency on the developing human brain. The findings are correlated to findings of experimental animals ranging from rodents to domestic pigs and non-human primates. The results point towards significant effects of iron deficiency on the developing brain. Evidence would be stronger with more studies addressing the human brain in real-time and the development of blood biomarkers of cerebral disturbance in iron deficiency. Cerebral iron deficiency is expected to be curable with iron substitution therapy, as the brain, privileged by the cerebral vascular transferrin receptor expression, is expected to facilitate iron extraction from the circulation and enable transport further into the brain.
Journal Article
Intravenous iron isomaltoside versus oral iron supplementation for treatment of iron deficiency in pregnancy: protocol for a randomised, comparative, open-label trial
by
Hansen, Rebecka
,
Thomsen, Lars Lykke
,
Markova, Veronika
in
Acids
,
Anemia
,
Anemia, Iron-Deficiency - drug therapy
2020
Background
Iron deficiency is common in pregnancy. If left untreated, iron deficiency can lead to iron deficiency anaemia, which is a condition related to maternal and neonatal morbidity. The prevalence of iron deficiency increases through the trimesters, which means that women with iron deficiency in the beginning of pregnancy also have a great risk of developing iron deficiency anaemia during pregnancy. Standard treatment is oral iron in individualised intensified doses based on screening values in 1st trimester.
Maternal symptoms of iron deficiency and iron deficiency anaemia include fatigue, reduced physical performance, and restless legs syndrome (RLS). Severe anaemia may cause dizziness, dyspnea, palpitation, orthostatism, and syncope, and it decreases the woman’s ability to cope with blood loss during delivery. The anaemia may also compromise contractility in the uterine musculature increasing the risk for prolonged labour, caesarean section, and postpartum haemorrhage. Foetal iron deficiency may cause low birthweight and adversely affect foetal and early childhood brain development with long-term deficits.
Methods
In this randomised comparative, open-label, single-centre, phase IV trial, 200 pregnant women between 14 and 21 weeks of gestation who have iron deficiency after 4 weeks of standard treatment will be randomised 1:1 to either a single 1000 mg dose of intravenously administered ferric derisomaltose/iron isomaltoside 1000 or a fixed dose of 100 mg oral ferrous fumarate containing 60 mg ascorbic acid.
The primary endpoint is to prevent iron deficiency anaemia defined by a low level of haemoglobin throughout the trial. Other endpoints include other haematological indices of iron deficiency and anaemia, clinical outcomes by questionnaires, and collection of adverse events. Explorative endpoints by medical record follow-up include complications up to 7 days after delivery.
Discussion
This trial will provide evidence on how to prevent iron deficiency anaemia. The trial population represents a clinical reality where pregnant women often have sustained iron deficiency despite an increased oral iron dose. Thus, this evidence can be used to consider the optimal 2nd line of treatment in iron-deficient pregnant women.
Trial registration
European Union Drug Regulating Authorities Clinical Trials Database 2017-000776-29. Registered on 3 May 2017.
ClinicalTrials.gov
NCT03188445
. Registered on 15 June 2017.
Journal Article
Iron deficiency and iron treatment in the fetal developing brain – a pilot study introducing an experimental rat model
2018
Background
Iron deficiency is especially common in women during the reproductive age and it is estimated that 52% of pregnant women have iron deficiency anemia. Maternal iron deficiency with or without anemia in pregnancy may have consequences for the fetus, where it may have an impact on the cerebral development of the brain. Both animals and adult human studies support that iron deficiency affects psychomotor development, behavioral traits, and cognitive functions in the offspring. However, it has not yet been established whether the availability of sufficient iron is particularly important in certain phases during brain development, and whether possible damages are reversible if iron supplementation is provided during pregnancy. Here we report results from a pilot study in an experimental rat model suitable for introducing iron deficiency in the fetal rat brain.
Methods
The model was utilized for examination of the potential to reverse changes in fetal brain iron by maternal parenteral iron administration. Fertilized females subjected to iron deficiency without anemia were subcutaneously injected with iron isomaltoside at the day of mating (E0), 14 days into pregnancy (E14), or at the day of birth (Postnatal (P) 0). Blood, brain and liver in the offspring were examined on P0 or in adulthood on postnatal day P70.
Results
Maternal iron restriction during pregnancy led to significantly lower levels of iron in the brains of newborn rats compared to levels in pups of iron sufficient mothers. Females fed ID diet (5.2 mg/kg Fe) had offspring with significantly lower cerebral iron compared to a control group fed a standard diet (158 mg/kg Fe). Injection of IIM to pregnant ID females on E0 or E14 yielded normalization of Fe in the developing brain known to express elevated levels of capillary transferrin receptors, indicating that the administered iron passed the placenta and fetal blood brain barrier.
Conclusions
In future studies, this translational model may be applied to examine morphological and biochemical consequences of iron deficiency and iron deficiency treatment in the developing fetal brain.
Journal Article
Intravenous ferric derisomaltose versus oral iron for persistent iron deficient pregnant women: a randomised controlled trial
2023
PurposeTo compare the efficacy of intravenous (IV) iron (ferric derisomaltose) with oral iron (ferrous fumarate) in women 14–21 weeks pregnant with persistent iron deficiency (ferritin < 30 µg/L).MethodsIn a single-centre, open-label, randomised controlled trial at a Danish hospital, women with persistent iron deficiency after routine oral iron treatment were allocated to receive 1000 mg IV iron (single-dose) or 100 mg elemental oral iron daily. Outcomes were assessed during an 18-week follow-up period. The primary endpoint was the proportion of non-anaemic (haemoglobin [Hb] ≥ 11 g/dL) women throughout follow-up. Other outcomes included changes in haematological parameters, patient-reported fatigue, and quality of life (QoL). Safety was assessed by recording adverse events.ResultsFrom July 2017 to February 2020, 100 women were randomised to IV iron and 101 to oral iron. Throughout follow-up, 91% of women were non-anaemic in the IV iron group compared with 73% in the oral iron group (18% difference [95% confidence interval 0.10–0.25]; p < 0.001). The mean Hb increase was significantly greater with IV iron versus oral iron at Weeks 6 (0.4 versus − 0.2 g/dL; p < 0.001), 12 (0.5 versus 0.1 g/dL; p < 0.001), and 18 (0.8 versus 0.5 g/dL; p = 0.01). Improvements in fatigue and QoL were greater with IV iron versus oral iron at Weeks 3 and 6. The incidence of treatment-related adverse events was comparable between treatment groups.ConclusionIV iron was superior in preventing anaemia compared with oral iron in pregnant women with persistent iron deficiency; biochemical superiority was accompanied by improved fatigue and QoL.Clinical trial registrationEuropean Clinical Trials Database: EudraCT no.: 2017-000776-29 (3 May 2017); ClinicalTrials.gov: NCT03188445 (13 June 2017).The trial protocol has been published: https://dx.doi.org/10.1186%2Fs13063-020-04637-z.
Journal Article
Signaling-specific inhibition of the CB1 receptor for cannabis use disorder: phase 1 and phase 2a randomized trials
by
Vallée, Monique
,
Cooper, Ziva D.
,
Shaham, Yavin
in
631/154/436/2387
,
631/378/1788
,
692/308/153
2023
Cannabis use disorder (CUD) is widespread, and there is no pharmacotherapy to facilitate its treatment. AEF0117, the first of a new pharmacological class, is a signaling-specific inhibitor of the cannabinoid receptor 1 (CB
1
-SSi). AEF0117 selectively inhibits a subset of intracellular effects resulting from Δ
9
-tetrahydrocannabinol (THC) binding without modifying behavior per se. In mice and non-human primates, AEF0117 decreased cannabinoid self-administration and THC-related behavioral impairment without producing significant adverse effects. In single-ascending-dose (0.2 mg, 0.6 mg, 2 mg and 6 mg;
n
= 40) and multiple-ascending-dose (0.6 mg, 2 mg and 6 mg;
n
= 24) phase 1 trials, healthy volunteers were randomized to ascending-dose cohorts (
n
= 8 per cohort; 6:2 AEF0117 to placebo randomization). In both studies, AEF0117 was safe and well tolerated (primary outcome measurements). In a double-blind, placebo-controlled, crossover phase 2a trial, volunteers with CUD were randomized to two ascending-dose cohorts (0.06 mg,
n
= 14; 1 mg,
n
= 15). AEF0117 significantly reduced cannabis’ positive subjective effects (primary outcome measurement, assessed by visual analog scales) by 19% (0.06 mg) and 38% (1 mg) compared to placebo (
P
< 0.04). AEF0117 (1 mg) also reduced cannabis self-administration (
P
< 0.05). In volunteers with CUD, AEF0117 was well tolerated and did not precipitate cannabis withdrawal. These data suggest that AEF0117 is a safe and potentially efficacious treatment for CUD.
ClinicalTrials.gov identifiers:
NCT03325595
,
NCT03443895
and
NCT03717272
.
The signaling-specific inhibitor AEF0117 selectively inhibits CB
1
activation by THC and reduces self-administration and subjective effects of cannabis in clinical trials, making it a potential treatment for cannabis use disorder.
Journal Article
No effect of pure oxygen inhalation on headache induced by glyceryl trinitrate
by
Thomsen, Lars Lykke
,
Iversen, Helle Klingenberg
,
Tfelt-Hansen, Peer
in
Adult
,
Biological and medical sciences
,
Cross-Over Studies
2010
Inhalation of hyperbaric oxygen has been used as an experimental treatment for migraine and pure oxygen is an established treatment for cluster headache. Intravenous glyceryl trinitrate (GTN) is an established headache model. In the present study the possibility of decreasing the headache by inhalation of pure oxygen was explored in a double-blind crossover design in 18 healthy subjects. Inhalation of air served as placebo. The subjects received intravenous GTN (0.25 µg/kg/min) for 20 min. Headache was scored for 85 min. Sixteen of 18 (89%) subjects experienced GTN-induced headache after O
2
-inhalation and 17/18 (94%) experienced GTN-induced headache after air. The mean peak headache scores were 1.9 and 2.4, respectively, on a numerical scale of 0–10. Oxygen inhalation did not have effect on GTN-induced headache, most likely because the theoretical decrease in NO levels, due to faster metabolism of NO, is too small to be detected in the GTN headache model.
Journal Article
Normalization of Fetal Cerebral and Hepatic Iron by Parental Iron Therapy to Pregnant Rats with Systemic Iron Deficiency without Anemia
by
Thomsen, Lars Lykke
,
Burkhart, Annette
,
Hertz, Sandra
in
Anemia
,
Anemia, Iron-Deficiency - drug therapy
,
Animals
2024
Background/Objectives: Iron (Fe) is a co-factor for enzymes of the developing brain necessitating sufficient supply. We investigated the effects of administering ferric derisomaltose/Fe isomaltoside (FDI) subcutaneously to Fe-deficient (ID) pregnant rats on cerebral and hepatic concentrations of essential metals and the expression of iron-relevant genes. Methods: Pregnant rats subjected to ID were injected with FDI on the day of mating (E0), 14 days into pregnancy (E14), or the day of birth (postnatal (P0)). The efficacy was evaluated by determination of cerebral and hepatic Fe, copper (Cu), and zinc (Zn) and gene expression of ferroportin, hepcidin, and ferritin H + L in pups on P0 and as adults on P70. Results: Females fed an ID diet (5.2 mg/kg Fe) had offspring with significantly lower cerebral and hepatic Fe compared to female controls fed a standard diet (158 mg/kg Fe). Cerebral Cu increased irrespective of supplying a standard diet or administering FDI combined with the standard diet. Hepatic hepcidin mRNA was significantly lower following ID. Cerebral hepcidin mRNA was hardly detectable irrespective of iron status. Conclusions: In conclusion, administering FDI subcutaneously to ID pregnant rats on E0 normalizes fetal cerebral and hepatic Fe. When applied at later gestational ages, supplementation with additional Fe to the offspring is needed to normalize cerebral and hepatic Fe.
Journal Article
Intravenous iron isomaltoside 1000 administered by high single-dose infusions or standard medical care for the treatment of fatigue in women after postpartum haemorrhage: study protocol for a randomised controlled trial
by
Thomsen, Lars Lykke
,
Holm, Charlotte
,
Langhoff-Roos, Jens
in
Anemia
,
Anemia, Iron-Deficiency - blood
,
Anemia, Iron-Deficiency - diagnosis
2015
Background
Postpartum haemorrhage can lead to iron deficiency with and without anaemia, the clinical consequences of which include physical fatigue. Although oral iron is the standard treatment, it is often associated with gastrointestinal side effects and poor compliance. To date, no published randomised controlled studies have compared the clinical efficacy and safety of standard medical care with intravenous administration of iron supplementation after postpartum haemorrhage.
The primary objective of this study is to compare the efficacy of an intravenous high single-dose of iron isomaltoside 1000 with standard medical care on physical fatigue in women with postpartum haemorrhage.
Methods/Design
In a single centre, open-labelled, randomised trial, women with postpartum haemorrhage exceeding 700 mL will be allocated to either a single dose of 1,200 mg of iron isomaltoside 1000 or standard medical care. Healthy parturients with a singleton pregnancy will be included within 48 hours after delivery.
Participants will complete structured questionnaires that focus on several dimensions of fatigue and mental health (Multidimensional Fatigue Inventory, Edinburgh Postnatal Depression Scale and the Postpartum Questionnaire), at inclusion and at follow-up visits after three days, one week, three weeks, eight weeks, and 12 weeks postpartum. The primary endpoint is the aggregated change in physical fatigue score within 12 weeks postpartum, as measured by a subscale of the Multidimensional Fatigue Inventory. The primary objective will be considered to have been met if an intravenous high single dose of iron isomaltoside 1000 is shown to be superior to standard medical care in women after postpartum haemorrhage regarding physical fatigue.
For claiming superiority, we set the minimal clinically relevant difference between the mean scores at 1.8, and the assumed standard deviation at 4.2. Hence, 87 participants per treatment group are needed in order to demonstrate superiority; to provide an extra margin for missing data and dropouts, 200 women will be included.
Discussion
The study will provide evidence on relevant clinical outcomes beyond biochemical parameters for intravenous iron isomaltoside 1000 compared to standard medical care in women after postpartum haemorrhage.
Trial registration
This trial is registered with Clinicaltrials.gov (identifier:
NCT01895218
) on 26 June 2013.
Journal Article
Signaling-specific inhibition of the CB 1 receptor for cannabis use disorder: phase 1 and phase 2a randomized trials
by
Vallée, Monique
,
Shaham, Yavin
,
Hebert-Chatelain, Etienne
in
Animals
,
Cannabis
,
Double-Blind Method
2023
Cannabis use disorder (CUD) is widespread, and there is no pharmacotherapy to facilitate its treatment. AEF0117, the first of a new pharmacological class, is a signaling-specific inhibitor of the cannabinoid receptor 1 (CB
-SSi). AEF0117 selectively inhibits a subset of intracellular effects resulting from Δ
-tetrahydrocannabinol (THC) binding without modifying behavior per se. In mice and non-human primates, AEF0117 decreased cannabinoid self-administration and THC-related behavioral impairment without producing significant adverse effects. In single-ascending-dose (0.2 mg, 0.6 mg, 2 mg and 6 mg; n = 40) and multiple-ascending-dose (0.6 mg, 2 mg and 6 mg; n = 24) phase 1 trials, healthy volunteers were randomized to ascending-dose cohorts (n = 8 per cohort; 6:2 AEF0117 to placebo randomization). In both studies, AEF0117 was safe and well tolerated (primary outcome measurements). In a double-blind, placebo-controlled, crossover phase 2a trial, volunteers with CUD were randomized to two ascending-dose cohorts (0.06 mg, n = 14; 1 mg, n = 15). AEF0117 significantly reduced cannabis' positive subjective effects (primary outcome measurement, assessed by visual analog scales) by 19% (0.06 mg) and 38% (1 mg) compared to placebo (P < 0.04). AEF0117 (1 mg) also reduced cannabis self-administration (P < 0.05). In volunteers with CUD, AEF0117 was well tolerated and did not precipitate cannabis withdrawal. These data suggest that AEF0117 is a safe and potentially efficacious treatment for CUD.ClinicalTrials.gov identifiers: NCT03325595 , NCT03443895 and NCT03717272 .
Journal Article