Oral bone loss induced by mineral deficiency in a rat model: Effect of a synthetic bone mineral (SBM) preparation

Osteoporosis affects the craniofacial and oral structures and has been associated with periodontal bone loss, tooth loss and reduced jaw bone mass.ObjectiveThis study aimed to test the therapeutic efficacy of synthetic bone mineral (SBM) in minimizing alveolar bone loss induced by mineral deficiency in a rat model. SBM consists of a calcium carbonate apatite (similar to bone apatite) matrix incorporating magnesium, zinc, and fluoride ions.DesignThirty female Sprague Dawley rats (2 months old) were randomly distributed into 3 groups (10 rats per group): GA (control), on basic diet; GB, on mineral deficient (MD) diet; and GC, on MD + SBM. The rats were sacrificed after 3 months, the jawbones were isolated and the soft tissues removed. Bone density was determined using X-ray radiography (Faxitron); mandibular cortical width, panoramic mandibular index, and alveolar resorption degree (M/M ratio) using BioquantOsteo; and bone micro-architecture micro-computed tomography and scanning electron microscopy.ResultsCompared to control (GA), the rats on MD diet (GB) experienced significant mandibular bone loss while the rats on MD + SBM diet (GC) experienced significantly less bone loss compared to the GB group.ConclusionSBM, administered orally, may have the potential as an osteoporosis therapeutic agent in minimizing or preventing alveolar bone loss induced by mineral deficiency.     

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.     

Episodic ataxia and severe infantile phenotype in spinocerebellar ataxia type 14: expansion of the phenotype and novel mutations

Journal of Neurology - Spinocerebellar ataxia type 14 (SCA14) is a dominantly inherited neurological disorder characterized by slowly progressive cerebellar ataxia. SCA14 is caused by mutations in...     

Clinical features and cognitive sequelae in COVID-19: a retrospective study on N=152 patients

Neurological Sciences - The novel human coronavirus (SARS-CoV-2) shows neurotropism and systemically affects the central nervous system (CNS). Cognitive deficits have been indeed reported as both...     

Episodic long-term memory in post-infectious SARS-CoV-2 patients

Neurological Sciences - Episodic long-term memory (LTM) difficulties/deficits are frequent in COVID-19-recovered patients and negatively impact on prognosis and outcome. However, little is known...