Subependymal nodules and giant cell tumours in tuberous sclerosis complex patients: prevalence on MRI in relation to gene mutation

Purpose

The purpose of this study was to estimate the association among the presence of subependymal nodules (SENs), subependymal giant cell tumours (SGCTs) and gene mutation in tuberous sclerosis complex (TSC) patients.

Methods

Clinical records and images of 81 TSC patients were retrospectively reviewed by two neuroradiologists in consensus. All patients were assessed for gene mutations and were categorized as TSC1 or TSC2 mutation carriers, or no-mutations-identified (NMI) patients. They underwent a brain magnetic resonance imaging (MRI) using 0.1 mmol/kg of gadobutrol. Any enhancing SEN?≥?1 cm and placed near the foramen of Monro was considered SGCT. Two MRI follow-up exams for each patient with SGCT were evaluated to assess tumour growth using Wilcoxon and chi-squared tests.

Results

Of 81 patients, 44 (54 %) were TSC2 mutation carriers, 20 (25 %) TSC1 and 17 (21 %) NMI. Nine (11 %) had a unilateral and three (4 %) a bilateral SGCT. Fifty of 81 patients (62 %) showed at least one SEN. None of the 31 patients without SEN showed SGCTs, whilst 12 (24 %) of the 50 patients with at least one SEN showed SGCTs (p?=?0.003). The association between the presence of SGCT or SEN and gene mutation was not significant (p?=?0.251 and p?=?0.187, respectively). At follow-up, the median SGCT diameter increased from 14 to 15 mm (p?=?0.017), whilst the median SGCT volume increased from 589 to 791 mm³ (p?=?0.006).

Conclusions

TSC patients with SENs are more likely to present with SGCT than those without SENs, in particular for TSC2 mutation carriers. The SGCT growth rate may be missed if based on the diameter instead of on the volume.     

Use of the Gait Profile Score for the evaluation of patients with joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type

Gait analysis (GA) is widely used for clinical evaluations in various pathological states, both in children and in adults, such as in patients with joint hypermobility syndrome/Ehlers–Danlos syndrome hypermobility type (JHS/EDS-HT). Otherwise, GA produces a large volume of data and there is the clinical need to provide also a quantitative measure of the patient's overall gait. Starting from this aim some global indexes were proposed by literature as a summary measure of the patient's gait, such as the Gait Profile Score (GPS). While validity of the GPS was demonstrated for the evaluation of the functional limitation of children with Cerebral Palsy, no studies have been conducted in patients JHS/EDS-HT. The aim of our study was therefore to investigate the effectiveness of the GPS in the quantification of functional limitation of patients with JHS/EDS-HT. Twenty-one adult (age: 36.1 ± 12.7 years) individuals with JHS/EDS-HT were evaluated using GA and from GA data the GPS was computed. The results evidenced that the GPS value of patients was 8.9 ± 2.6, statistically different from 4.6 ± 0.9 displayed by the control group. In particular, all values of Gait Variable Scores (GVS) which compose the GPS were higher if compared to controls, with the exception of Pelvic Tilt and Foot Progression. The correlations between GPS/GVS and Lower Extremity Functional Scale (LEFS) showed significant relationship between GPS and the item 11 (“Walking 2 blocks”) (ρ = ?0.56; p < 0.05) and 12 (“Walking a mile”) of LEFS (ρ = ?0.76; p < 0.05). Our results showed that GPS and GVS seem to be appropriate outcome measures for the evaluation of the functional limitation during gait of patients with JHS/EDS-HT.     

<Emphasis Type="Italic">V</Emphasis>O<Subscript>2Max</Subscript> and <Emphasis Type="Italic">V</Emphasis>O<Subscript>2AT</Subscript>: athletic performance and field role of elite soccer players

Purpose

Maximal oxygen consumption (VO_2max) and oxygen consumption at anaerobic threshold (VO_2AT) are commonly measured parameters to test elite soccer players; however, studies relating metabolic parameters of professional soccer players with performance and best fitting to the field role are scarce. Our aim was to study the relations of VO_2max and VO_2AT with the field role of elite soccer players to generate a robust dataset with a solid statistical analysis.

Method

Over a 12-year period we performed 953 field evaluation tests of VO_{2 max} and VO_2AT on 450 elite soccer players of 13 professional teams by incremental, continuous and exhausting test modified from Conconi’s test. Statistical analysis was performed by one-way ANOVA followed—when appropriate—by Tukey post hoc test. Effect size was evaluated by the Cohen D test and η partial squared test. Statistical significance was set for p < 0.05.

Results

VO_2max mean values increased at the beginning of season by 1.073 ± 0.06 respect to pre-season then decreased again up to pre-season levels and remained stable, while VO_2AT did not change during time. VO_2max differences were also related to players’ field role. VO_2max mean value for Goalkeeper was 50.85 ± 4.2, for central Defender was 57.58 ± 4.3, for Winger-sides back was 60.53 ± 5.02, for Midfielder was 59.53 ± 5.08, for Forward was 56.52 ± 4.14. On the contrary, as expected, VO_2AT percentage variations among the roles were not significant.

Conclusions

VO_2max is the choice parameter to consider for the metabolic compliance of athletes to the field role requirements, consequently influencing training programs, recovery and injury prevention strategies.

     

A truncation in the RYR1 gene associated with central core lesions in skeletal muscle fibres

A novel single-nucleotide deletion in exon 100 of the RYR1 gene, corresponding to deletion of nucleotide 14,510 in the human RyR1 mRNA (c14510delA), was identified in a man with malignant hyperthermia and in his two daughters who were normal for malignant hyperthermia. This deletion results in a RyR1 protein lacking the last 202 amino acid residues. All three subjects heterozygotic for the mutated allele presented with a prevalence of type 1 fibres with central cores, although none experienced clinical signs of myopathy. Expression of the truncated protein resulted in non-functional RYR1 calcium release channels. Expression of wild-type and RyR1(R4836fsX4838) proteins resulted in heterozygotic release channels with overall functional properties similar to those of wild-type RyR1 channels. Nevertheless, small differences in sensitivity to calcium and caffeine were observed in heterotetrameric channels, which also presented an altered assembly/stability in sucrose-gradient centrifugation analysis. Altogether, these data suggest that altered RYR1 tetramer assembly/stability coupled with subtle chronic changes in Ca2+ homoeostasis over the long term may contribute to the development of core lesions and incomplete malignant hyperthermia susceptibility penetrance in individuals carrying this novel RYR1 mutation.     

Insulin replacement restores the behavioral effects of quinpirole and raclopride in streptozotocin-treated rats

Streptozotocin (STZ)-induced diabetes can modulate dopamine (DA) neurotransmission and thereby modify the behavioral effects of drugs acting on DA systems. Insulin replacement, and in some conditions repeated treatment with amphetamine, can partially restore sensitivity of STZ-treated rats to dopaminergic drugs. The present study sought to characterize the role of insulin and amphetamine in modulating the behavioral effects of drugs that selectively act on D2/D3 receptors. In control rats, quinpirole and quinelorane produced yawning, whereas raclopride and gamma-hydroxybutyric acid (GHB) produced catalepsy. Raclopride antagonized quinpirole- and quinelorane-induced yawning with similar potency. STZ treatment increased blood glucose concentration, decreased body weight, and markedly reduced sensitivity to quinpirole-induced yawning, quinelorane-induced yawning as well as to raclopride-induced catalepsy, while enhancing sensitivity to GHB-induced catalepsy. Repeated treatment with amphetamine partially restored sensitivity of STZ-treated rats to amphetamine-stimulated locomotion and also produced conditioned place preference, without affecting blood glucose and body weight changes. However, amphetamine treatment did not restore sensitivity to the behavioral effects of quinpirole, raclopride, or GHB, suggesting differential regulation of dopamine transporter activity and sensitivity of D2 receptors in hypoinsulinemic rats. Insulin replacement in STZ-treated rats normalized blood glucose and body weight changes and fully restored sensitivity to quinpirole-induced yawning, as well as to raclopride-induced catalepsy, while reducing sensitivity to GHB-induced catalepsy. Overall, these data indicate that changes in insulin status markedly affect sensitivity to the behavioral effects of dopaminergic drugs. The results underscore the importance of insulin in modulating DA neurotransmission; these effects might be especially relevant to understanding the co-morbidity of eating disorders and substance abuse.     

Specific identification of Habronema microstoma and Habronema muscae (Spirurida, Habronematidae) by PCR using markers in ribosomal DNA

Gastric or cutaneous habronemosis caused by Habronema microstoma Creplin, 1849 and Habronema muscae Carter, 1865 is a parasitic disease of equids transmitted by muscid flies. There is a paucity of information on the epidemiology of this disease, which is mainly due to limitations with diagnosis in the live animal and with the identification of the parasites in the intermediate hosts. To overcome such limitations, a molecular approach, based on the use of genetic markers in the second internal transcribed spacer (ITS-2) of ribosomal DNA, was established for the two species of Habronema. Characterisation of the ITS-2 revealed sequence lengths and G+C contents of 296 bp and 29.5% for H. microstoma, and of 334 bp and 35.9% for H. muscae, respectively. Exploiting the sequence difference (approximately 40%) between the two species of nematode, primers were designed and tested by the polymerase chain reaction (PCR) for their specificity using a panel of control DNA samples from common equid endoparasites, and from host tissues, faeces or muscid flies. Effective amplification from each of the two species of Habronema was achieved from as little as 10 pg of genomic DNA. Hence, this molecular approach allows the specific identification and differentiation of the DNA from H. microstoma and H. muscae, and could thus provide a molecular tool for the specific detection of Habronema DNA (irrespective of developmental stage) from faeces, skin and muscid fly samples. The establishment of this tool has important implications for the specific diagnosis of clinical cases of gastric and cutaneous habronemosis in equids, and for studying the ecology and epidemiology of the two species of Habronema.     

Surgical delivery of drug releasing poly(lactic-co-glycolic acid)/poly(ethylene glycol) paste with in vivo effects against glioblastoma

Introduction

The median survival of patients with glioblastoma multiforme (astrocytoma grade 4) remains less than 18 months despite radical surgery, radiotherapy and systemic chemotherapy. Surgical implantation of chemotherapy eluting wafers into the resection cavity has been shown to improve length of survival but the current licensed therapy has several drawbacks. This paper investigates in vivo efficacy of a novel drug eluting paste in glioblastoma.

Methods

Poly(lactic-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) self-sintering paste was loaded with the chemotherapeutic agent etoposide and delivered surgically into partially resected tumours in a flank murine glioblastoma xenograft model.

Results

Surgical delivery of the paste was successful and practical, with no toxicity or surgical morbidity to the animals. The paste was retained in the tumour cavity, and preliminary results suggest a useful antitumour and antiangiogenic effect, particularly at higher doses. Bioluminescent imaging was not affected significantly by the presence of the paste in the tumour.

Conclusions

Chemotherapy loaded PLGA/PEG paste seems to be a promising technology capable of delivering active drugs into partially resected tumours. The preliminary results of this study suggest efficacy with no toxicity and will lead to larger scale efficacy studies in orthotopic glioblastoma models.