Comparison of Diffusion-weighted MRI using Singe-Shot Echo-planar Imaging (SS-EPI) and Split Acquisition of Fast Spin Echo Signal (SPLICE) Imaging, a non-EPI technique, in Tumors of the Head and Neck.

Background And Purpose: Diffusion-weighted imaging (DWI) using single-shot echo planar imaging (DW-EPI) is susceptible to distortions around air-filled cavities and dental fillings, typical for the head and neck area. Non-EPI, Split acquisition of fast spin echo signals for diffusion imaging (DWSPLICE) could reduce these distortions and enhance image quality, thereby potentially improving recurrence assessment in squamous cell carcinoma (SCC) of the head and neck region. This study evaluated whether DW-SPLICE is a viable alternative to DW-EPI through quantitative and qualitative analyses.

Hepatic arterial infusion pump chemotherapy combined with systemic chemotherapy for borderline resectable and unresectable colorectal liver metastases: phase II feasibility study.

Background: Hepatic arterial infusion pump chemotherapy combined with systemic chemotherapy (HAIP-SYS) for liver-only colorectal liver metastases (CRLMs) has shown promising results but has not been adopted worldwide. This study evaluated the feasibility of HAIP-SYS in the Netherlands.

Methods: This was a single-arm phase II study of patients with CRLMs who received HAIP-SYS consisting of floxuridine with concomitant systemic FOLFOX or FOLFIRI.

Multi-sequence MRI radiomics of colorectal liver metastases: Which features are reproducible across readers?

Purpose: To assess the inter-reader reproducibility of radiomics features on multiple MRI sequences after segmentations of colorectal liver metastases (CRLM).

Method: 30 CRLM (in 23 patients) were manually delineated by three readers on MRI before the start of chemotherapy on the contrast enhanced T1-weighted images (CE-T1W) in the portal venous phase, T2-weighted images (T2W) and b800 diffusion weighted images (DWI). DWI delineations were copied to the ADC-maps.

Purinergic regulation of brain catecholamine neurotransmission: In vivo electrophysiology and microdialysis study in rats.

It was previously reported that adenosine-2A (A2A) receptors interact with dopamine-2 (D2) receptors on a molecular level. The aim of the current study was to investigate the functional output of this interaction. In vivo microdialysis was used to assess the effects of an antagonist of A2A receptors, ZM 241385, and an antagonist of D2 receptors haloperidol, either alone or in combination, on brain catecholamine levels.

Increased noradrenergic neurotransmission to a pain facilitatory area of the brain is implicated in facilitation of chronic pain.

Background: Noradrenaline reuptake inhibitors are known to produce analgesia through a spinal action but they also act in the brain. However, the action of noradrenaline on supraspinal pain control regions is understudied. The authors addressed the noradrenergic modulation of the dorsal reticular nucleus (DRt), a medullary pronociceptive area, in the spared nerve injury (SNI) model of neuropathic pain.

Glutamatergic regulation of brain histamine neurons: In vivo microdialysis and electrophysiology studies in the rat.

The interactions between the glutamatergic and the histaminergic systems in the brain are not fully understood. Here we studied histamine release in the medial prefrontal cortex and the posterior hypothalamus-tuberomamillary nucleus (PH-TMN) using in vivo microdialysis and electrophysiological recordings of histaminergc neurons in the PH-TMN in vivo to further address the mechanistic details of these interactions. We demonstrated that histaminergic activity was regulated by group II metabotropic glutamate receptors (mGluR 2 and 3) using systemic dosing with mGluR 2/3 agonist and antagonists and an mGluR 2 positive allosteric modulator.

GABA acting on GABAB receptors located in a medullary pain facilitatory area enhances nociceptive behaviors evoked by intraplantar formalin injection.

The dorsal reticular nucleus (DRt) plays a key role in facilitation of nociceptive transmission at the spinal cord. In this study, we evaluated the mechanisms involved in GABA-mediated control of the DRt focusing on the role of local GABAB receptors. First, we used in vivo microdialysis to study the release of GABA in the DRt during the course of the formalin test.

Interaction Between Brain Histamine and Serotonin, Norepinephrine, and Dopamine Systems: In Vivo Microdialysis and Electrophysiology Study.

Brain monoamines (serotonin, norepinephrine, dopamine, and histamine) play an important role in emotions, cognition, and pathophysiology and treatment of mental disorders. The interactions between serotonin, norepinephrine, and dopamine were studied in numerous works; however, histamine system received less attention. The aim of this study was to investigate the interactions between histamine and other monoamines, using in vivo microdialysis and electrophysiology.

In vivo continuous and simultaneous monitoring of brain energy substrates with a multiplex amperometric enzyme-based biosensor device.

Enzyme-based amperometric biosensors are widely used for monitoring key biomarkers. In experimental neuroscience there is a growing interest in in vivo continuous and simultaneous monitoring of metabolism-related biomarkers, like glucose, lactate and pyruvate. The use of multiplex biosensors will provide better understanding of brain energy metabolism and its role in neuropathologies such as diabetes, ischemia, and epilepsy.

Microdialysis-coupled enzymatic microreactor for in vivo glucose monitoring in rats.

Continuous glucose monitoring (CGM) is an important aid for diabetic patients to optimize glycemic control and to prevent long-term complications. However, current CGM devices need further miniaturization and improved functional performance. We have coupled a previously described microfluidic chip with enzymatic microreactor (EMR) to a microdialysis probe and evaluated the performance of this system for monitoring subcutaneous glucose concentration in rats.

Lentiviral delivery of a vesicular glutamate transporter 1 (VGLUT1)-targeting short hairpin RNA vector into the mouse hippocampus impairs cognition.

Glutamate is the principle excitatory neurotransmitter in the mammalian brain, and dysregulation of glutamatergic neurotransmission is implicated in the pathophysiology of several psychiatric and neurological diseases. This study utilized novel lentiviral short hairpin RNA (shRNA) vectors to target expression of the vesicular glutamate transporter 1 (VGLUT1) following injection into the dorsal hippocampus of adult mice, as partial reductions in VGLUT1 expression should attenuate glutamatergic signaling and similar reductions have been reported in schizophrenia. The VGLUT1-targeting vector attenuated tonic glutamate release in the dorsal hippocampus without affecting GABA, and selectively impaired novel object discrimination (NOD) and retention (but not acquisition) in the Morris water maze, without influencing contextual fear-motivated learning or causing any adverse locomotor or central immune effects.

Prevalence of Dupuytren disease in The Netherlands.

Background: Dupuytren disease is a fibroproliferative disease of palmar fascias of the hand. The prevalence of Dupuytren disease and the association with potential risk factors have been the subject of several studies, although there is a paucity of such data from The Netherlands.

Methods: To study the prevalence of Dupuytren disease, the authors drew a random sample of 1360 individuals, stratified by age, from the northern part of The Netherlands.

Noradrenaline increases pain facilitation from the brain during inflammatory pain.

Antidepressants that inhibit the recapture of noradrenaline have variable effects in chronic pain which may be related to the complex role of noradrenaline in pain modulation. Whereas at the spinal cord noradrenaline blocks nociceptive transmission, both antinociception and pronociception were reported after noradrenaline release in the brain. To study the role of noradrenaline in pain modulatory areas of the brain, we elected the dorsal reticular nucleus (DRt), a key pain facilitatory area located at the medulla oblongata.

Effects of amphetamine on dopamine release in the rat nucleus accumbens shell region depend on cannabinoid CB1 receptor activation.

The psychostimulant drug amphetamine is often prescribed to treat Attention-Deficit/Hyperactivity Disorder. The behavioral effects of the psychostimulant drug amphetamine depend on its ability to increase monoamine neurotransmission in brain regions such as the nucleus accumbens (NAC) and medial prefrontal cortex (mPFC). Recent behavioral data suggest that the endocannabinoid system also plays a role in this respect.

Evaluation of permselective membranes for optimization of intracerebral amperometric glutamate biosensors.

Monitoring of extracellular brain glutamate concentrations by intracerebral biosensors is a promising approach to further investigate the role of this important neurotransmitter. However, amperometric biosensors are typically hampered by Faradaic interference caused by the presence of other electroactive species in the brain, such as ascorbic acid, dopamine, and uric acid. Various permselective membranes are often used on biosensors to prevent this.

The role of cortical and hypothalamic histamine-3 receptors in the modulation of central histamine neurotransmission: an in vivo electrophysiology and microdialysis study.

The current study aimed to investigate the effect of histamine-3 (H(3)) receptors, expressed in the tuberomammillary nucleus (TMN) of the hypothalamus and in the prefrontal cortex (PFC), on histamine neurotransmission in the rat brain. The firing activity of histamine neurons in the TMN was measured using in vivo extracellular single-unit electrophysiology, under propofol anesthesia. Extracellular histamine levels were determined using the dual (PFC and TMN) probe microdialysis, in freely-moving animals.

CB-1 receptors modulate the effect of the selective serotonin reuptake inhibitor, citalopram on extracellular serotonin levels in the rat prefrontal cortex.

A large percentage of depressed individuals use drugs of abuse, like cannabis. This study investigates the impact of cannabis on the pharmacological effects of the antidepressant citalopram. Using microdialysis in the prefrontal cortex of rats we monitored serotonin levels before and after cannabinoid (WIN55,212-2 or rimonabant) and citalopram administration.

Direct effect of nicotine on mesolimbic dopamine release in rat nucleus accumbens shell.

Nicotine stimulates dopamine (DA) cell firing via a local action at somatodendritic sites in the ventral tegmental area (VTA), increasing DA release in the nucleus accumbens (NAcc). Additionally, nicotine may also modulate DA release via a direct effect in the NAcc. This study examined the contribution of the latter mechanism on NAcc DA release by applying nicotine systemically, as well as locally in the VTA and NAcc shell region in rats.

The pharmacokinetics and pharmacological effect of (S)-5-OH-DPAT following controlled delivery with transdermal iontophoresis.

The pharmacokinetic (PK) and pharmacodynamic (PD) properties of the active (S)-enantiomer of the potent dopamine (DA) agonist 5-hydroxy-2-(N,N,-di-n-propylamino)tetralin (5-OH-DPAT) were investigated in a novel anesthetized animal model. First, the relationship between current density, in vivo transport, and plasma profile was characterized. Second, the effect of the anesthetic mixture, transdermal iontophoresis, and blood sampling on the striatal DA release (PD end point) was investigated.

Biochemical and behavioral effects of long-term citalopram administration and discontinuation in rats: role of serotonin synthesis.

We have investigated effects of continuous SSRI administration and abrupt discontinuation on biochemical and behavioral indices of rat brain serotonin function, and attempted to identify underlying mechanisms. Biochemistry of serotonin was assessed with brain tissue assays and microdialysis; behavior was assessed as the acoustic startle reflex. Long-term SSRI administration to rats reduced the content of 5-HT and its main metabolite shortly after inhibition of 5-HT synthesis in many brain areas with more than 50%.

An enzymatic microreactor based on chaotic micromixing for enhanced amperometric detection in a continuous glucose monitoring application.

The development of continuous glucose monitoring systems is a major trend in diabetes-related research. Small, easy-to-wear systems which are robust enough to function over many days without maintenance are the goal. We present a new sensing system for continuous glucose monitoring based on a microreactor incorporating chaotic mixing channels.

Evaluation of temperature rise and bonding strength in cements used for permanent head attachments in rats and mice.

In animal models, devices such as indwelling catheters and intracranial cannulae are often fixed on the skull to allow sampling or injection in the freely moving animal. The most commonly used method to fixate these devices is by embedding them in a 'helmet' of cement which is fixed to the skull with screws. Methylmethacrylate cement is commonly used for this purpose.

The in vitro and in vivo evaluation of new synthesized prodrugs of 5-OH-DPAT for iontophoretic delivery.

The feasibility of transdermal iontophoretic transport of 4 novel ester prodrugs of 5-OH-DPAT (glycine-, proline-, valine- and beta-alanine-5-OH-DPAT) was investigated in vitro and in vivo. Based on the chemical stability of the prodrugs, the best candidates were selected for in vitro transport studies across human skin. The pharmacokinetics and pharmacodynamic effects of the prodrug with highest transport efficiency, were investigated in a rat model.

Microfiltration sampling in rats and in cows: toward a portable device for continuous glucocorticoid hormone sampling.

To monitor temporal patterns of glucocorticoids hormones in living animals, most often blood samples are collected. Blood sampling is invasive and subjects may find it--in particular--unpleasant when multiple samples are collected. We have developed a microfiltration collection device (MCD) sampling continuously, pulse-free, over a selected period of time, with minimum invasiveness as the device is inserted with only one venipuncture.

Oxazepam and temazepam attenuate paroxetine-induced elevation of serotonin levels in guinea-pig hippocampus.

Selective serotonin (5-HT) reuptake inhibitors (SSRIs) are used as a first-line treatment in depression. However, many depressed patients are also treated with benzodiazepines to alleviate increased anxiety and sleep disturbances normally associated with depression. Since benzodiazepines inhibit 5-HT neuronal firing activity, they might attenuate SSRI-induced increase in extracellular 5-HT levels.