Publications by authors named "Hiskias Keizer"

Various models for ageing, each focussing on different biochemical and/or cellular pathways have been proposed. This has resulted in a complex and non-coherent portrayal of ageing. Here, we describe a concise and comprehensive model for the biochemistry of ageing consisting of three interacting signalling hubs.

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Article Synopsis
  • Despite extensive research, the exact cause of Alzheimer's disease (AD) is still unknown, leading to a new hypothesis focusing on the enzyme carnitine palmitoyl transferase-2 (CPT2) as a key player in the disease.
  • CPT2, found in the inner mitochondrial membrane, is vital for fatty acid metabolism and is particularly sensitive to hydrogen peroxide, which is produced in excess by major AD risk factors.
  • The inhibition of CPT2 due to increased hydrogen peroxide levels may contribute to the symptoms of AD, offering new insights for potential therapeutic strategies.
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Human milk oligosaccharides (HMOs) belong to a group of multifunctional glycans that are abundantly present in human breast milk. While health effects of neutral oligosaccharides have been investigated extensively, a lot remains unknown regarding health effects of acidic oligosaccharides, such as the two sialyllactoses (SLs), 3'sialyllactose (3'SL), and 6'sialyllactose (6'SL). We utilized () to investigate the effects of SLs on exercise performance.

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Scope: The 9cis,11trans-conjugated linoleic acid (9c,11t-CLA) is reported to have anti-atherogenic properties in animal models and to modulate protein expression in unstimulated human platelets in vivo. Platelet function was therefore investigated after dietary supplementation with 9c,11t-CLA enriched oil (CLA80:20) in a randomized, baseline-controlled cross-over trial.

Methods And Results: Forty-three healthy adults at low to moderate risk of cardiovascular disease received 4 g/day of CLA80:20 or placebo for two weeks each.

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The "cholesterol hypothesis" is the leading theory to explain the cause of atherosclerosis. The "cholesterol hypothesis" assumes that plasma (LDL) cholesterol is an important causal factor for atherosclerosis.However, data of at least seven placebo controlled randomized prospective trials with various cholesterol lowering drugs show that plasma cholesterol lowering does not necessarily lead to protection against cardiovascular disease.

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The 5-HT(6) receptor (5-HT(6)R) has been in the spotlight for several years regarding CNS-related diseases. We set out to discover novel, neutral 5-HT(6)R antagonists to improve off-target selectivity compared to basic amine-containing scaffolds dominating the field. High-throughput screening identified the N'-(sulfonyl)pyrazoline-1-carboxamidine scaffold as a promising neutral core for starting hit-to-lead.

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Background: Pomegranate seed oil has been shown to protect against diet induced obesity and insulin resistance.

Objective: To characterize the metabolic effects of punicic acid on high fat diet induced obesity and insulin resistance.

Design: High-fat diet or high-fat diet with 1% Pomegranate seed oil (PUA) was fed for 12 weeks to induce obesity and insulin resistance.

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In this paper a sub-chronic (13 weeks) toxicity study in rats and an in vitro genotoxicity study with Korean pine (Pinus koraiensis Siebold & Zucc.) nut oil, KPNO (PinnoThin) are described. Both studies were performed in compliance with GLP, and in line with OECD guidelines applicable.

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Appetite suppressants may be one strategy in the fight against obesity. This study evaluated whether Korean pine nut free fatty acids (FFA) and triglycerides (TG) work as an appetite suppressant. Korean pine nut FFA were evaluated in STC-1 cell culture for their ability to increase cholecystokinin (CCK-8) secretion vs.

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Certain free fatty acids have been shown to have potent effects on food intake and self-reported changes in appetite; effects associated with increases in the release of endogenous cholecystokinin (CCK) and glucagon like peptide-1 (GLP-1). In the current study, the effects of a Korean pine nut oil product, PinnoThin, at doses 2 g, 4 g and 6 g triglyceride (TG) and 2 g free fatty acid (FFA), on food intake and appetite were examined in a cross-over double-blind placebo-controlled randomised counter-balanced design in 42 overweight female volunteers. 2 g FFA PinnoThin, given 30 minutes prior to an ad-libitum buffet test lunch, significantly reduced food intake (gram) by 9% (F(4,164) = 2.

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We have investigated a series of 7-azaindoles as potential partial agonists of the alpha4beta2 nicotinic acetylcholine receptor (nAChR). Three series of 7-azaindole derivatives have been synthesized and evaluated for rat brain neuronal nicotinic receptor affinity and functional activity. Compound (+)-51 exhibited the most potent nAChR binding (Ki = 10 nM).

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A series of novel bicyclic 1-heteroaryl-4-[omega-(1H-indol-3-yl)alkyl]piperazines was synthesized and evaluated on binding to dopamine D(2) receptors and serotonin reuptake sites. This class of compounds proved to be potent in vitro dopamine D(2) receptor antagonists and in addition were highly active as serotonin reuptake inhibitors. Some key representatives showed potent pharmacological in vivo activities after oral dosing in both the antagonism of apomorphine-induced climbing and the potentiation of 5-HTP-induced behavior in mice.

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Series of thiazoles, triazoles, and imidazoles were designed as bioisosteres, based on the 1,5-diarylpyrazole motif that is present in the potent CB(1) receptor antagonist rimonabant (SR141716A, 1). A number of target compounds was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The thiazoles, triazoles, and imidazoles elicited in vitro( )()CB(1) antagonistic activities and in general exhibited considerable CB(1) vs CB(2) receptor subtype selectivities, thereby demonstrating to be cannabinoid bioisosteres of the original diarylpyrazole class.

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A series of novel 3,4-diarylpyrazolines was synthesized and evaluated in cannabinoid (hCB(1) and hCB(2)) receptor assays. The 3,4-diarylpyrazolines elicited potent in vitro CB(1) antagonistic activities and in general exhibited high CB(1) vs CB(2) receptor subtype selectivities. Some key representatives showed potent pharmacological in vivo activities after oral dosing in both a CB agonist-induced blood pressure model and a CB agonist-induced hypothermia model.

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