HGPS and related premature aging disorders: from genomic identification to the first therapeutic approaches

Progeroid syndromes are heritable human disorders displaying features that recall premature ageing. In these syndromes, premature aging is defined as "segmental" since only some of its features are accelerated. A number of cellular biological pathways have been linked to aging, including regulation of the insulin/growth hormone axis, pathways involving ROS metabolism, caloric restriction, and DNA repair. The number of identified genes associated with progeroid syndromes has increased in recent years, possibly shedding light as well on mechanisms underlying ageing in general. Among these, premature aging syndromes related to alterations of the LMNA gene have recently been identified. This review focuses on Hutchinson-Gilford Progeria syndrome and Restrictive Dermopathy, two well-characterized Lamin-associated premature aging syndromes, pointing out the current knowledge concerning their pathophysiology and the development of possible therapeutic approaches.     

Late-onset OCD as presenting manifestation of semantic dementia

Semantic dementia (SD) is a neurodegenerative disease belonging to the spectrum of frontotemporal dementia that presents with loss of memory for words and prevalent left temporal pole atrophy. Behavioral disorders, particularly obsessive-compulsive symptoms, are frequent during the course of the disease. We describe a patient presenting with late-onset typical obsessive-compulsive disorder (OCD) that lasted for 10 years as an isolated condition before developing clinical and neuroimaging features of SD. This case alerts clinicians that late-onset OCD may be a psychiatric presentation of a neurodegenerative disorder such as frontotemporal dementia and requires an accurate diagnostic work-up.     

Posterior reversible encephalopathy syndrome associated with Guillain-Barré syndrome: Case report and clinical management considerations

Around half of the patients with Guillain-Barré syndrome (GBS) present autonomic dysfunction requiring admission to intensive care unit in up to a quarter of patients. Treatment of GBS consists of plasma exchange (PE) and intravenous immunoglobulins (IVIG). Posterior reversible encephalopathy syndrome (PRES) consists in a reversible subcortical vasogenic brain edema caused by endothelial damage triggered by abrupt blood pressure changes. We report on a woman who presented with PRES in the course of GBS treated first with IVIG, and then with PE. The present report underlines the challenge that the clinicians face when these two rare syndromes concur. The literature is not helpful considering that both blood pressure fluctuations and IVIG are reported to be involved in the pathogenesis of PRES. In the present letter, both pathogenic mechanisms and clinical management considerations are discussed.     

Pathology of valved venous homografts used as right ventricle-to-pulmonary artery conduits in congenital heart disease surgery

Objectives

Although valved venous homografts (VVHs) are used for establishing right ventricle-to-pulmonary artery continuity in some complex heart defects, the tissue changes that occur in situ have not been described. We review the gross and microscopic changes observed in explanted VVH conduits and their effects on functionality.

A new integrated dual time-point amyloid PET/MRI data analysis method

Purpose

In the initial evaluation of patients with suspected dementia and Alzheimer’s disease, there is no consensus on how to perform semiquantification of amyloid in such a way that it: (1) facilitates visual qualitative interpretation, (2) takes the kinetic behaviour of the tracer into consideration particularly with regard to at least partially correcting for blood flow dependence, (3) analyses the amyloid load based on accurate parcellation of cortical and subcortical areas, (4) includes partial volume effect correction (PVEC), (5) includes MRI-derived topographical indexes, (6) enables application to PET/MRI images and PET/CT images with separately acquired MR images, and (7) allows automation.

Methods

A method with all of these characteristics was retrospectively tested in 86 subjects who underwent amyloid (¹⁸F-florbetaben) PET/MRI in a clinical setting (using images acquired 90–110 min after injection, 53 were classified visually as amyloid-negative and 33 as amyloid-positive). Early images after tracer administration were acquired between 0 and 10 min after injection, and later images were acquired between 90 and 110 min after injection. PVEC of the PET data was carried out using the geometric transfer matrix method. Parametric images and some regional output parameters, including two innovative “dual time-point” indexes, were obtained.

Results

Subjects classified visually as amyloid-positive showed a sparse tracer uptake in the primary sensory, motor and visual areas in accordance with the isocortical stage of the topographic distribution of the amyloid plaque (Braak stages V/VI). In patients classified visually as amyloid-negative, the method revealed detectable levels of tracer uptake in the basal portions of the frontal and temporal lobes, areas that are known to be sites of early deposition of amyloid plaques that probably represented early accumulation (Braak stage A) that is typical of normal ageing. There was a strong correlation between age and the indexes of the new dual time-point amyloid imaging method in amyloid-negative patients.

Conclusions

The method can be considered a valuable tool in both routine clinical practice and in the research setting as it will standardize data regarding amyloid deposition. It could potentially also be used to identify early amyloid plaque deposition in younger subjects in whom treatment could theoretically be more effective.

     

A bullet wandering through the heart

We report a case of young male with a penetrating chest trauma due to a gunshot. The bullet was detected by conventional X-ray and localized within the lateral wall of the left ventricle by CT. During surgery the bullet was not found. Thereafter conventional X-ray showed migration of the bullet within the lung parenchyma.     

“In-house” pharmacological management for computed tomography coronary angiography: heart rate reduction, timing and safety of different drugs used during patient preparation

We retrospectively evaluated the effect, timing and safety of different pharmacological strategies during 64-slice CT coronary angiography (CT-CA). From the institutional database of CT-CA we enrolled 560 consecutive patients with suspected coronary artery disease. The type of drug preparation (group 1 = no treatment; group 2 = oral metoprolol; group 3 = other; group 4?=?intravenous (IV) atenolol; group 5?=?IV atenolol + nitrates; NR = non-responders), timing, and adverse effects were recorded. Heart rate (HR) during different preparation phases was recorded. Four adverse effects were recorded, none of which was attributable to pharmacological treatment. In all groups, except group 1, the HR on arrival was significantly reduced by the pharmacological treatment (p?<?0.01). Group 4 showed the best (?16?±?8 bpm) HR reduction. There was no significant effect on HR due to nitrates (p?=?0.49), while a slight increase due to contrast material was noted (p?<?0.05). Average time required for preparation was 44?±?25 min. Groups 4 and 5 showed the most effective timing (8?±?9 min and 8?±?8 min, respectively; p?<?0.01). Pharmacological preparation in patients undergoing CT-CA is safe and effective. Best results in terms of HR reduction and fast preparation are obtained with IV administration of beta-blockers.     

De novo RANBP2 variant in a fetal demise case with cerebral intraparenchymal hemorrhage

Fetal intracranial hemorrhage (ICH) may result from a wide array of causes, either associated with maternal or fetal risk factors. In the last decade, monogenic causes of susceptibility to fetal ICH have been described, in particular in association with COL4A1 and COL4A2 genes. A peculiar form of ICH is acute necrotizing encephalitis (ANE), which is characterized by a rapid-onset severe encephalopathy following an abnormal inflammatory response to an otherwise banal infection. It usually affects healthy children and it is thought to be multifactorial, with a genetic predisposition. RANBP2 gene has been extensively associated with ANE susceptibility. We hereby present a unique case of a 42-year-old secundigravida with intrauterine fetal demise at 35 weeks of gestation. Trio-based whole-exome sequencing performed on both parents and fetal DNA showed a de novo likely pathogenic variant in the RANBP2 gene on 2q13. At the fetal autopsy, subtentorial hematoma and cerebral intraparenchymal hemorrhage were present. We speculate that this might be a new phenotypic presentation of RANBP2-associated disease. However, more similar fetal cases need to be reported in order to reinforce this hypothesis.     

Critical subaortic stenosis due to fibromuscular ridge in a 66-year-old woman: 2D-3D echocardiography findings

Subvalvular aortic stenosis (SAS) can be either a fixed stenosis resulting from subaortic anatomical obstacle or a dynamic stenosis because of hypertrophic cardiomyopathy. Here, we report a patient with a rare subaortic circumferential fibromuscular tunnel who became unusually symptomatic in her sixth decade of life. Transthoracic and mostly transesophageal echocardiography with 3D application is the preferred diagnostic modality. Indications for surgery include symptoms and LVOT gradient of 50 mm Hg. Our purpose is an image focus on this infrequent case.