Radiopaque marker colonic transit study in the pediatric population BSPGHAN Motility Working Group consensus statement

Functional constipation (FC) is a common condition in childhood in the United Kingdom and worldwide. Various radiological approaches have been established for diagnostic purposes. The radiopaque marker study (ROMS) is universally accepted and used to assess colonic transit time (CTT) in children with FC. Despite being widely used, there is a lack of standardization with various technical protocols, reproducibility of different populations, the purpose for using investigation, variance in the number of markers used, the amount of study days and calculations, the need to empty the colon before performing the test, and whether to perform on medication or off, or the use of specific diets. As part of the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) motility working group (MWG), we decided to explore further into the evidence, in order to provide guidance regarding the use of ROMS in dealing with FC in the pediatric population.

Rare coding variant analysis in a large cohort of Ashkenazi Jewish families with inflammatory bowel disease

Rare variants are thought to contribute to the genetics of inflammatory bowel disease (IBD), which is more common amongst the Ashkenazi Jewish (AJ) population. A family-based approach using exome sequencing of AJ individuals with IBD was employed with a view to identify novel rare genetic variants for this disease. Exome sequencing was performed on 960 Jewish individuals including 513 from 199 multiplex families with up to eight cases. Rare, damaging variants in loci prioritized by linkage analysis and those shared by multiple affected individuals within the same family were identified. Independent evidence of association of each variant with disease was assessed. A number of candidate variants were identified, including in genes involved in the immune system. The ability to achieve statistical significance in independent case/control replication data was limited by power and was only achieved for variants in the well-established Crohn's disease gene, NOD2. This work demonstrates the challenges of identifying disease-associated rare damaging variants from exome data, even amongst a favorable cohort of familial cases from a genetic isolate. Further research of the prioritized rare candidate variants is required to confirm their association with the disease.

GPR133 (ADGRD1), an adhesion G-protein-coupled receptor, is necessary for glioblastoma growth

Glioblastoma (GBM) is a deadly primary brain malignancy with extensive intratumoral hypoxia. Hypoxic regions of GBM contain stem-like cells and are associated with tumor growth and angiogenesis. The molecular mechanisms that regulate tumor growth in hypoxic conditions are incompletely understood. Here, we use primary human tumor biospecimens and cultures to identify GPR133 (ADGRD1), an orphan member of the adhesion family of G-protein-coupled receptors, as a critical regulator of the response to hypoxia and tumor growth in GBM. GPR133 is selectively expressed in CD133+ GBM stem cells (GSCs) and within the hypoxic areas of PPN in human biospecimens. GPR133 mRNA is transcriptionally upregulated by hypoxia in hypoxia-inducible factor 1α (Hif1α)-dependent manner. Genetic inhibition of GPR133 with short hairpin RNA reduces the prevalence of CD133+ GSCs, tumor cell proliferation and tumorsphere formation in vitro. Forskolin rescues the GPR133 knockdown phenotype, suggesting that GPR133 signaling is mediated by cAMP. Implantation of GBM cells with short hairpin RNA-mediated knockdown of GPR133 in the mouse brain markedly reduces tumor xenograft formation and increases host survival. Analysis of the TCGA data shows that GPR133 expression levels are inversely correlated with patient survival. These findings indicate that GPR133 is an important mediator of the hypoxic response in GBM and has significant protumorigenic functions. We propose that GPR133 represents a novel molecular target in GBM and possibly other malignancies where hypoxia is fundamental to pathogenesis.

Effect of dietary supplementation with fish oil during the transition period on milk production, plasma metabolites and postpartum anoestrus interval in grazing dairy cows

Inclusion of fish oil (FO) in the diet of dairy cows could improve the energy status and milk yield and reduce the interval from calving to first postpartum ovulation, but the effects may differ depending on the specific period of supplementation. To test these hypotheses, 28 pregnant Holstein heifers were randomly assigned to four treatments in a 2 × 2 factorial design: prepartum oral drench of FO (0 or 140 g/cow.day) for 21 days before calving, and/or postpartum oral drench of FO (0 or 190 g/cow.day) for 21 days after calving. Prepartum, heifers grazed in native pastures with supplements of wheat silage and wheat bran, while postpartum, cows grazed on improved pastures with addition of concentrates and corn silage. No interaction between prepartum and postpartum FO was detected for any variable analysed. Prepartum and postpartum total DM intake, milk yield, protein yield and percentage were not different among treatments. Milk fat percentage (3.83 versus 3.34 ± 0.10%) and yield (0.88 versus 0.73 ± 0.04 kg/day) decreased with postpartum FO but were not affected by prepartum FO. Prepartum and postpartum body condition score and plasma concentration of non-esterified fatty acids and cholesterol were not different among treatments, but urea concentration was higher in cows drenched with FO during prepartum (5.91 versus 4.64 ± 0.35 mM). Proportion of cows that ovulated the dominant follicle of the first postpartum wave and days to first postpartum ovulation, as determined by ovarian ultrasonography, were not affected by drenching with FO, but size of the dominant follicle in the first wave was decreased when FO was drenched only during the pre- or postpartum period compared with drenching in both periods. Dietary supplementation with FO during the postpartum period affected milk fat synthesis but more research is needed to establish its effects on resumption of ovarian activity in grazing dairy cows.

Heart rate and blood lactate evaluation in bouldering elite athletes

AIM

Bouldering contests consist of a series of short routes, called ''problems'', which shall be climbed without ropes. The purpose of this study was to determine blood lactate [Lac] concentration and heart rate (HR) adaptations both during an official bouldering competition and a simulated contest.

METHODS

Eleven Italian elite climbers (6 males, 5 females) were tested from two bouldering national competitions (BNC). [Lac] assessments were done before and 2, 4, 6, 8 min after the contest. On a separate occasion, 9 different elite climbers (6 males, 3 females), matched for anthropometric features and ranking, were assessed in a simulated bouldering contest (SBC), under conditions and difficulties comparable to BNC. HR was measured through the whole performance; [Lac] was assessed before and 3 min after the achievement of each problem.

RESULTS

The ascending time in both BNC and SBC was 391+/-85 s and 551+/-96 s (P<0.001), respectively. During SBC the mean HR peak of each problem was 93+/-8% of the subjects' age-predicted maximal HR (HRmax), and HR showed a full recovery after each problem, but in males only. Peak [Lac] after last problem was 6.6+/-1.1 mmol/L and 5.6+/-1.1 mmol/L during BNC and SBC, respectively. A regression analysis showed that temporal changes in [Lac] depend on the attempts duration, with a critical cut-off time of 20 s.

CONCLUSIONS

Bouldering contest requires an intense intermittent effort. The high HR may be due to the repeated isometric contractions, particularly of arm and forearm muscles. The net lactate production may depend on the attempts duration.

Effect of prepartum energetic supplementation on productive and reproductive characteristics, and metabolic and hormonal profiles in dairy cows under grazing conditions

The effect of cracked corn grain supplementation (3.5 kg/day) during 3 weeks before the expected calving date on milk production and composition, body condition score (BCS), metabolic and hormonal profiles and length of postpartum anoestrus was evaluated in multiparous Holstein dairy cows under grazing conditions (Energy supplemented group, n = 10; Control group, n = 10). Body condition score was weekly recorded during the peripartum period, from days -21 to +35 (parturition = day 0). Non-esterified fatty acids, beta-hydroxybutyrate, cholesterol, urea, insulin, insulin-like growth factor I (IGF-I), leptin, thyroxine (T(4)) and 3,3''5-triiodothyroinine (T(3)) were weekly determined in plasma from days -21 to +35. The reinitiation of ovarian cyclicity was twice weekly determined by ovarian ultrasonography and confirmed by plasma progesterone concentrations. Cows fed energy concentrate prepartum had higher BCS during the prepartum and postpartum and produced more milk. Non-esterified fatty acids plasma concentrations were significantly higher in the energy group, while cholesterol was higher in the control group. Treated cows had higher levels of plasma insulin, IGF-I and leptin pre-calving. IGF-I, leptin and T(4) were diminished during the early postpartum period in both groups. Insulin levels were also diminished in the control group, but levels remained high in the energy-supplemented group. Treated cows ovulated sooner after parturition than controls. We conclude that Energetic supplementation prepartum in cows under grazing conditions increased milk production and reduced the reinitiation of ovarian activity, consistent with a better EB (BCS), higher prepartum levels of IGF-I, leptin and insulin, and higher insulin levels during early postpartum.

Spinal cord GLT-1 glutamate transporter and blood glutamic acid alterations in motor neuron degeneration (Mnd) mice

This study characterizes for the first time neurochemical mechanisms in Mnd mice, initially described as a model of motor neuron disease and more recently proposed as a model for neuronal ceroid lipofuscinosis. A selective decrease (-30%) of [3H]glutamate uptake was found in spinal cord but not cortical synaptosomes of Mnd mice aged 28 weeks, when they show histopathological alterations, complete blindness and moderate neurological deficits. In spite of the widespread presence of stored material in neurons in many brain regions and spinal cord, the active transport of [3H]serotonin, [3H]dopamine and depolarization-induced [3H]serotonin release were not affected. Spinal EAAC1 glutamate transporter protein was significantly decreased in some but not all aged mice by 36% on average, possibly due to the loss of motor neurons. GLT-1 immunoreactivity was reduced by 34% in 28-week-old Mnd mice, while GLAST immunoreactivity was not affected. In Mnd mice aged 14 weeks, when there was no apparent alteration of motor function, the defect in the glial transporter protein GLT-1 was similar to that in 28-week-old mice (25%). Blood glutamic acid concentration was increased in Mnd mice aged 14-22 weeks. We suggest that the early decrease of GLT-1 protein might raise the extrasynaptic glutamic acid concentration, and contribute to the loss of motor neurons in affected mice, resulting in low [3H]glutamate uptake, low EAAC1 immunoreactivity and neurological deficits.

Lasting increase in serotonin 5-HT1A but not 5-HT4 receptor subtypes in the kindled rat dentate gyrus: dissociation from local presynaptic effects

We examined the effect of kindling on serotonergic neurotransmission in the hippocampus by measuring serotonin (5-HT) release and uptake in hippocampal synaptosomes and 5-HT1A and 5-HT4 receptor subtypes during and at different times after electrical kindling of the dentate gyrus. Using quantitative receptor autoradiography, we found that binding of 8-[3H]hydroxy-2-(di-n-propylamino)tetralin ([3H]8-OH-DPAT) to 5-HT1A receptors was selectively increased by 20% on average (p < 0.05) in the dentate gyrus of the stimulated and contralateral hippocampus 2 days after stage 2 (stereotypes and occasional retraction of a forelimb) and by 100% on average (p < 0.05) 1 week after stage 5 (tonic-clonic seizures) compared with sham-stimulated rats. A 20% increase (p < 0.05) was observed 1 month after the last generalized seizure. No changes were found after a single afterdischarge. 5-HT4 receptors, which colocalize with 5-HT1A receptors on hippocampal neurons, were not modified in kindled tissue. [3H]5-HT uptake and its release as well as the 5-HT1B autoreceptor function did not differ from shams in hippocampal synaptosomes at stages 2 and 5. Systemic administration of 100 and 1,000 microg kg(-1) 8-OH-DPAT or 1,000 microg kg(-1) WAY-100,635, 30 min before each electrical stimulation, did not significantly alter kindling progression or the occurrence of stage 5 seizures in fully kindled rats. The changes in 5-HT1A receptor density in the dentate gyrus are part of the plastic modifications occurring during kindling and may contribute to modulating tissue hyperexcitability.

[Chronic lymphatic leukemia and large granular lymphocytes]

Chronic large granular lymphocyte leukemia is a rather rare disorder (less than 5% of LLC). Its subtype CD3+/CD8+ is often a clonal disease and without malignant characteristics. This kind of disease shows a clinical and laboratory heterogeneity, probably due to the immunological and functional variety of granular lymphocytes. In some cases of LGL leukemia an associated pathology, especially rheumatoid arthritis and chronic infections, has been reported. On the contrary, the relationship with neoplasms has been rarely proved in literature: only occasional studies have been reported and anyway they are not supported by a sufficient number of cases. Two cases of LGL leukemia are here delineated: a woman with advanced breast adenocarcinoma and another one with Sjögren disease. The first one had a rapidly fatal course, while the other one had a prolonged clinical course with chronic neutropenia (13 years follow-up). The association between carcinoma and LGL leukemia may be just a casual finding but the hypothesis of a possible relationship is however very interesting on account of the important role of granular lymphocytes in controlling tumoral growth. Moreover, both patients had concomitant chronic HCV-correlated infection: maybe it will worth making a prevalence study with a greater number of cases, in order to evaluate a probable relationship between these pathologies. The growth factor G-CSF may be useful in the treatment of infections that often occur in patients with severe neutropenia.

Carrier-dependent and Ca(2+)-dependent 5-HT and dopamine release induced by (+)-amphetamine, 3,4-methylendioxymethamphetamine, p-chloroamphetamine and (+)-fenfluramine

1. The mechanism underlying 5-hydroxytryptamine (5-HT) and/or dopamine release induced by (+)-amphetamine ((+)-Amph), 3,4-methylendioxymethamphetamine (MDMA), p-chloroamphetamine (pCA) and (+)-fenfluramine ((+)-Fen) was investigated in rat brain superfused synaptosomes preloaded with the 3H neurotransmitters. 2. Their rank order of potency for [3H]-5-HT-releasing activity was the same as for inhibition of 5-HT uptake (pCA > or = MDMA > or = (+)-Fen > > (+)-Amph). Similarly, their rank order as [3H]-dopamine releasers and dopamine uptake inhibitors was the same ((+)-Amph > > pCA = MDMA > > (+)-Fen). We also confirmed that the release induced by these compounds was prevented by selective transporter inhibitors (indalpine or nomifensine). 3. [3H]-5HT and/or [3H]-dopamine release induced by all these compounds was partially (31-80%), but significantly Ca(2+)-dependent. Lack of extracellular Ca2+ did not alter uptake mechanisms nor did it modify the carrier-dependent dopamine-induced [3H]-dopamine release. (+)-Amph-induced [3H]-dopamine release and pCA- and MDMA-induced [3H]-5-HT release were significantly inhibited by omega-agatoxin-IVA, a specific blocker of P-type voltage-operated Ca(2+)-channels, similar to the previous results on (+)-Fen-induced [3H]-5-HT release. 4. Methiothepin inhibited the Ca(2+)-dependent component of (+)-Amph-induced [3H]-dopamine release with high potency (70 nM), as previously found with (+)-Fen-induced [3H]-5-HT release. The inhibitory effect of methiothepin was not due to its effects as a transporter inhibitor or Ca(2+)-channel blocker and is unlikely to be due to its antagonist properties on 5-HT1/2, dopamine or any other extracellular receptor. 5. These results indicate that the release induced by these compounds is both 'carrier-mediated' and Ca(2+)-dependent (possibly exocytotic-like), with the specific carrier allowing the amphetamines to enter the synaptosome. The Ca(2+)-dependent release is mediated by Ca(2+)-influx (mainly through P-type Ca(2+)-channels), possibly triggered by the drug interacting with an unknown intracellular target, affected by methiothepin, common to both 5-HT and dopamine synaptosomes.

Effects of chronic treatment with fluoxetine and citalopram on 5-HT uptake, 5-HT1B autoreceptors, 5-HT3 and 5-HT4 receptors in rats

The effect in rats of chronic treatment with two specific 5-HT reuptake inhibitors (SSRI) with antidepressant properties, citalopram (10 mg/kg, i.p. twice a day for 14 days, one day washout) and fluoxetine (15 mg/kg, p.o. twice a day for 21 days, 7 days washout), was evaluated on some mechanisms involved in central 5-HT neurotransmission. No adaptive modifications of brain 5-HT uptake (sites) were found by measuring functional [3H]5-HT uptake and [3H]citalopram binding in cortical and hippocampal synaptosomes, and by [3H]citalopram binding autoradiography in the raphe nuclei (5-HT cell bodies) and the ventral tegmental area (5-HT axonal pathway). Chronic treatments had no effect on presynaptic 5-HT1B autoreceptors, functionally evaluated by measuring 5-HT1B-mediated inhibition of depolarization-induced [3H]5-HT release from cortical and hippocampal synaptosomes. Chronic citalopram or fluoxetine did not significantly affect the binding of [3H]BRL-43694 to 5-HT3 receptors in the rat brain cortex. Citalopram had no effect on [125I]SB-207710 binding to 5-HT4 receptors, measured by autoradiography in the substantia nigra. Negative results, such as those reported in the present study, could be due to a number of variables including the animal species, the treatment schedule or the brain areas considered, thus explaining the differences from some previous reports of significant effects of SSRI. However, our negative data are in agreement with many other published studies, suggesting that adaptive modifications of brain 5-HT transporters, terminal 5-HT1B receptors, 5-HT3 and 5-HT4 receptors may not be a general effect induced by all SSRI.

Carrier-mediated serotonin release induced by d-fenfluramine: studies with human neuroblastoma cells transfected with a rat serotonin transporter

The NMB human neuronal cell line, transfected with a newly prepared plasmid expressing rat serotonin transporter (NMB-rSERT), shows specific [3H]5-HT uptake which is blocked by citalopram and fenfluramine (F) stereoisomers with IC50 values (1 nM. 0.5 microM (dF) and and 5 microM (IF), respectively) which are similar to those found in rat brain synaptosomes. d-Fenfluramine (0.5 and 10 microM) also stimulates tritium release from NMB-rSERT cells preloaded with [3H-]-5-HT. The d-fenfluramine-induced [3H-]5-HT release is blocked by 0.3 microM citalopram and is dependent on the density of SERT expressed per cell, but is not affected by removal of Ca++ ions from the incubation medium. Manipulation of the Na+ gradient across the plasma membrane (replacing 60 mM NaCl with an equimolar concentration of KCl or choline) also induced [3H-]5-HT release from NMB-rSERT cells, which was inhibited by 0.3 microM citalopram. These results, together with the finding that NMB-rSERT cells preloaded with 500 nM unlabelled 5-HT take up [3H-]d-fenfluramine, make NMB-rSERT cells a valuable tool for studying the transporter-mediated exchange release induced by amphetamine derivatives.

5-HT3 serotonin hetero-receptors inhibit [3H]acethylcholine release in rat cortical synaptosomes

The present study was designed to verify the presynaptic localization of 5-HT3 serotonin receptors on cholinergic, serotonergic and dopaminergic nerve endings in rat brain regions where they have been shown to modulate the release of these neurotransmitters. We measured the effect of 5-HT3 agonists on [3H] neurotransmitter release from superfused synaptosomes as a functional assay of the presence of 5-HT3 serotonin receptors. m-Cl-phenylbyguanide (m-Cl-PBG, 1 microM) inhibited by 18% depolarization-evoked [3H]acethylcholine (ACh) release from cortical synaptosomes, and this effect was blocked by a potent and selective 5-HT3 antagonist based on the arylpiperazine skeleton (VC 135, 0.03 microM). Ondansetron (0.1 microM) per se had an inhibitory effect as well, thus making it difficult to evaluate its interaction with m-Cl-PBG. Up to 10 microM, m-Cl-PBG did not affect [3H]dopamine release in striatum, nucleus accumbens and frontal cortex. A similar, although not significant inhibition (16%) of [3H]ACh release, was obtained with 2-methylserotonin (10 microM), which, at this concentration, did not modify either basal or depolarization-induced release of [3H]serotonin in hippocampus or [3H]dopamine in striatum. IN conclusion, our data suggest that 5-HT3 hetero-receptors are located on cortical nerve endings where they directly inhibit acethylcholine release, but they do not seem to be located on serotonergic and dopaminergic nerve endings in the brain regions studied, probably having an indirect effect on these neurotransmitters release in rat brain.

In vivo and in vitro interaction of flunarizine with D-fenfluramine serotonergic effects

Flunarizine (35 mg/kg), but not haloperidol and trifluperazine, counteracted the initial indole depletion induced by D-fenfluramine (dF) in vivo (5 mg/kg), without affecting ex vivo [3H]-serotonin (5-HT) uptake by synaptosomes or changing the brain concentrations of the parent drug and its main active metabolite, D-norfenfluramine (dNF). The long-term indole depletion induced by repeated doses of dF (5 mg/kg, b.i.d. for 4 days) was also reversed by flunarizine pretreatment. Flunarizine, methiothepin, and trifluperazine, but not haloperidol, reduced in vitro the Ca(2+)-dependent [3H]5-HT release stimulated by 0.5 microM dF and dNF from superfused synaptosomes. At the concentrations used in release experiments the drugs were not active on [3H]5-HT uptake nor on the calcium-calmodulin protein kinase activity, thus excluding an effect on the uptake carrier or on phosphorylation of synaptic proteins involved in exocytosis, respectively. The drugs did not consistently affect [3H]5-HT release induced by depolarization, or dNF-induced [3H]dopamine release in vitro. The fact that flunarizine, as methiothepin and 5-HT uptake inhibitors, counteract dF-induced indole depletion in vivo suggests a relation between the reduction of the Ca(2+)-dependent release of [3H]5-HT induced by dF in vitro and the protective effect on the short- and long-lasting depletion of indoles induced in vivo by high doses of dF.

Effects of fluoxetine on basal and K(+)-induced tritium release from synaptosomes preloaded with [3H]serotonin

Synaptosomes from rat brain cortex and spinal cord were preloaded with [3H]serotonin ([3H]5-HT), superfused and exposed to fluoxetine and/or 15 mM K+. In both regions 10 microM, but not 1 microM fluoxetine evoked a marked tritium overflow, about 2 min later than the immediate [3H]5-HT release induced by K+, and mainly (73%) due to the efflux of a tritiated metabolite of 5-HT, possibly [3H]5-hydroxy-indoleacetic acid. These findings confirm previous data in the rat hippocampus and are probably due to fluoxetine interacting with the 5-HT storage vesicles. One microM fluoxetine significantly reduced the d-fenfluramine-induced [3H]5-HT overflow, in accordance with its action as 5-HT uptake blocker, but did not affect the K(+)-induced [3H]5-HT overflow. This latter finding does not confirm that fluoxetine inhibits the depolarization-induced Ca(2+)-influx, suggested to involve a drug interaction with the L-type Ca(2+)-channels. Thus, the overflow induced by 10 microM fluoxetine was additive with the depolarization-induced overflow, when the two stimuli were applied together. When 10 microM fluoxetine was added 7 min before 15 mM K+, there was no depolarization-induced overflow. Such inhibition might be only apparent and due either to the fluoxetine-induced loss of vesicular 5-HT or to a fluoxetine-induced alterations of synaptic vesicles. The in vivo relevance of the fluoxetine releasing effect remains to be assessed.