Longitudinal evaluation of cognitive functioning in pediatric multiple sclerosis: report from the US Pediatric Multiple Sclerosis Network

BACKGROUND

Approximately one-third of those with pediatric-onset multiple sclerosis (MS) experience cognitive impairment. Less is known concerning their change in cognitive functioning over time.

OBJECTIVE

Changes in cognitive function over time were measured in the largest pediatric cohort to date through the US Network of Pediatric MS Centers.

METHODS

A total of 67 individuals with pediatric MS (n=62) or clinically isolated syndrome (CIS, n=5), ranging from 8-17 years of age (mean age ± standard deviation (SD)=14.37 ± 2.02) completed initial and follow-up neuropsychological testing after an average of 1.64 ± 0.63 years apart. The nine tests administered measure general intellect, attention and working memory, verbal memory, visuomotor integration, language, and executive functioning.

RESULTS

Rate of impairment (having one-third or more scores in the impaired range) was 37% at baseline and 33% at follow-up. Tests commonly impaired were measures of visuomotor integration, speeded processing, and attention. Most tested did not decline over two years. There was no clear pattern of change on any specific measure.

CONCLUSION

Findings suggest that, over short timeframes, stable or even improved performances on measures of cognitive ability can occur. Pediatric MS may instead prevent expected age-related cognitive gains.

Tumour cell retention of rucaparib, sustained PARP inhibition and efficacy of weekly as well as daily schedules

Background:

Poly(ADP-ribose) polymerase-1 (PARP) inhibitors (PARPi) exploit tumour-specific defects in homologous recombination DNA repair and continuous dosing is most efficacious. Early clinical trial data with rucaparib suggested that it caused sustained PARP inhibition. Here we investigate the mechanism of this durable inhibition and potential exploitation.

Methods:

Uptake and retention of rucaparib and persistence of PARP inhibition were determined by radiochemical and immunological assays in human cancer cell lines. The pharmacokinetics and pharmacodynamics of rucaparib were determined in tumour-bearing mice and the efficacy of different schedules of rucaparib was determined in mice bearing homologous recombination DNA repair-defective tumours.

Results:

Rucaparib accumulation is carrier mediated (Km=8.4±1.2 μM, Vmax=469±22 pmol per 10⁶ cells per 10 min), reaching steady-state levels >10 times higher than the extracellular concentration within 30 min. Rucaparib is retained in cells and inhibits PARP ⩾50% for ⩾72 h days after a 30-min pulse of 400 nM. In Capan-1 tumour-bearing mice rucaparib accumulated and was retained in the tumours, and PARP was inhibited for 7 days following a single dose of 10 mg kg⁻¹ i.p or 150 mg kg⁻¹ p.o. by 70% and 90%, respectively. Weekly dosing of 150 mg kg⁻¹ p.o once a week was as effective as 10 mg kg⁻¹ i.p daily for five days every week for 6 weeks in delaying Capan-1 tumour growth.

Conclusions:

Rucaparib accumulates and is retained in tumour cells and inhibits PARP for long periods such that weekly schedules have equivalent anticancer activity to daily dosing in a pre-clinical model, suggesting that clinical evaluation of alternative schedules of rucaparib should be considered.

Differential expression and cellular localization of novel isoforms of the tendon biomarker tenomodulin

Tenomodulin (Tnmd, also called Tendin) is classified as a type II transmembrane glycoprotein and is highly expressed in developing as well as in mature tendons. Along with scleraxis (scx), Tnmd is a candidate marker gene for tenocytes. Its function is unknown, but it has been reported to have anti-angiogenic properties. Results in a knockout mouse model did not substantiate that claim. It has homology to chondromodulin-I. Single nucleotide polymorphisms of TNMD have been associated with obesity, macular degeneration, and Alzheimer's disease in patients. In the present study, three Tnmd isoforms with deduced molecular weights of 20.3 (isoform II), 25.4 (isoform III), and 37.1 (isoform I) kDa were proposed and verified by Western blot from cells with green fluorescent protein-linked, overexpressed constructs, tissue, and by qPCR of isoforms from human tissues and cultured cells. Overexpression of each Tnmd isoform followed by immunofluorescence imaging showed that isoforms I and II had perinuclear localization while isoform III was cytoplasmic. Results of qPCR demonstrated differential expression of each Tnmd isoform in patient's specimens taken from flexor carpi radialis, biceps brachii, and flexor digitorum profundus tendons. Knockdown of Tnmd increased the expression of both scleraxis (scx) and myostatin, indicating a potential negative feedback loop between Tnmd and its regulators. Knockdown of all Tnmd isoforms simultaneously also reduced tenocyte proliferation. I-TASSER protein three-dimensional conformation modeling predictions indicated each Tnmd isoform had different structures and potential functions: isoform 1, modeled as a cytosine methyltransferase; isoform 2, a SUMO-1-like SENP-1 protease; and isoform 3, an α-syntrophin, plextrin homology domain scaffolding protein. Further functional studies with each Tnmd isoform may help us to better understand regulation of tenocyte proliferation, tendon development, response to injury and strain, as well as mechanisms in tendinoses. These results may indicate novel therapeutic targets in specific tenomodulin isoforms as well as treatments for tendon diseases.

The Effects of Children on the Process of Recovery in Oxford Houses

The effects of children on the process of substance use recovery for adults living in Oxford Houses is explored in two qualitative studies. Oxford Houses are self-run, community-based residential homes for small groups of adults who live together and support each other's efforts to recover from drug and/or alcohol addiction. In the first study, telephone interviews were conducted with 29 adults who were living in Oxford Houses that allowed children to live in the house with their parent. Results suggest that having children in the house supported a positive living environment for the recovery of house members. In the second study, telephone interviews were conducted with an additional 15 mothers who lived in Oxford Houses. These interviews focused on the effects of the mothers' addiction and recovery on their relationships with their children. This study found that most parents acknowledged the negative effects of their addiction on their relationship with their child and the effects of their recovery on improving those relationships.

Investigation of the presence of ghrelin in the central nervous system of the rat and mouse

Ghrelin and ghrelin receptor agonist have effects on central neurons in many locations, including the hypothalamus, caudal brain stem, and spinal cord. However, descriptions of the distributions of ghrelin-like immunoreactivity in the CNS in published work are inconsistent. We have used three well-characterized anti-ghrelin antibodies, an antibody to the unacylated form of ghrelin, and a ghrelin peptide assay in rats, mice, ghrelin knockout mice, and ghrelin receptor reporter mice to re-evaluate ghrelin presence in the rodent CNS. The stomach served as a positive control. All antibodies were effective in revealing gastric endocrine cells. However, no specific staining could be found in the brain or spinal cord. Concentrations of antibody 10 to 30 times those effective in the stomach bound to nerve cells in rat and mouse brain, but this binding was not reduced by absorbing concentrations of ghrelin peptide, or by use of ghrelin gene knockout mice. Concentrations of ghrelin-like peptide, detected by enzyme-linked immunosorbent assay in extracts of hypothalamus, were 1% of gastric concentrations. Ghrelin receptor-expressing neurons had no adjacent ghrelin immunoreactive terminals. It is concluded that there are insignificant amounts of authentic ghrelin in neurons in the mouse or rat CNS and that ghrelin receptor-expressing neurons do not receive synaptic inputs from ghrelin-immunoreactive nerve terminals in these species.

Quantifying show jumping horse rider expertise using IMUs

Horse rider ability has long been measured using horse performance, competition results and visual observation. Scientific methods of measuring rider ability on the flat are emerging such as measuring position angles and harmony of the horse-rider system. To date no research has quantified rider ability in show jumping. Kinematic analysis and motion sensors have been used in sports other than show jumping to measure the quality of motor control patterns in humans. The aim of this study was to quantify rider ability in show jumping using body-mounted IMUs. Preliminary results indicate that there are clear differences in experienced and novice riders during show jumping.

Alarin stimulates food intake and gonadotrophin release in male rats

BACKGROUND AND PURPOSE

Alarin is a recently discovered member of the galanin peptide family encoded by a splice variant of galanin-like peptide (GALP) mRNA. Galanin and GALP regulate energy homeostasis and reproduction. We therefore investigated the effects of alarin on food intake and gonadotrophin release.

EXPERIMENTAL APPROACH

Alarin was administered into the third cerebral ventricle (i.c.v.) of rats, and food intake or circulating hormone levels were measured. The effect of alarin on the hypothalamo-pituitary-gonadal axis was investigated in vitro using hypothalamic and anterior pituitary explants, and immortalized cell lines. Receptor binding assays were used to determine whether alarin binds to galanin receptors.

KEY RESULTS

The i.c.v. administration of alarin (30 nmol) to ad libitum fed male rats significantly increased acute food intake to 500%, and plasma luteinizing hormone (LH) levels to 170% of responses to saline. In vitro, 100 nM alarin stimulated neuropeptide Y (NPY) and gonadotrophin-releasing hormone (GnRH) release from hypothalamic explants from male rats, and 1000 nM alarin increased GnRH release from GT1-7 cells. In vivo, pretreatment with the GnRH receptor antagonist cetrorelix prevented the increase in plasma LH levels observed following i.c.v. alarin administration. Receptor binding studies confirmed alarin did not bind to any known galanin receptor, or compete with radiolabelled galanin for hypothalamic binding sites.

CONCLUSIONS AND IMPLICATIONS

These results suggest alarin is a novel orexigenic peptide, and that it increases circulating LH levels via hypothalamic GnRH. Further work is required to identify the receptor(s) mediating the biological effects of alarin.

Cerebellin1 is a novel orexigenic peptide

AIM

Cerebellin1 (Cbln1) is highly expressed in the hypothalamus, a region of the brain involved in appetite regulation. However, the effects of Cbn1 on food intake are not known. The present study aimed to investigate the effect of Cbln1 on appetite regulation in rats.

METHODS

We determined the effect of (i) intracerebroventricular (ICV) injection of Cbln1 on food intake, behaviour and plasma pituitary hormone levels in male Wistar rats; (ii) Cbln1 on the release of hypothalamic neuropeptides known to modulate food intake from hypothalamic explants and (iii) fasting on hypothalamic Cbln1 mRNA expression.

RESULTS

(i) ICV administration of Cbln1 significantly increased food intake in rats and caused no adverse behaviours. ICV administration of Cbln1 significantly reduced plasma thyroid stimulating hormone (TSH) levels 10 min postinjection in rats. (ii) Cbln1 significantly increased the release of neuropeptide Y (NPY) from hypothalamic explants. (iii) Cbln1 mRNA expression levels were increased in the ventromedial nucleus of the hypothalamus in fasted rats.

CONCLUSIONS

These data suggest that Cbln1 is a novel orexigenic peptide, which may mediate its effects via hypothalamic NPY.