Current and Emerging Treatment Modalities for Leber’s Hereditary Optic Neuropathy: A Review of the Literature

Introduction

The purpose of this review is to present the current and emerging treatment alternatives for Leber’s hereditary optic neuropathy (LHON), emphasizing the most recent use of idebenone and stem cells or gene therapy.

Methods

A comprehensive literature review was performed at the PubMed database regarding the various treatment modalities for LHON.

Results

Treatment modalities for LHON include nutritional supplements, activators of mitochondrial biogenesis, brimonidine, and symptomatic and supportive treatment, but nowadays attention is being paid to idebenone and gene therapy or stem cells.

Conclusion

The treatment of LHON remains challenging, given the nature of the disease and its prognosis.

     

Ghrelin secretion in humans is sexually dimorphic,suppressed by somatostatin,and not affected by the ambient growth hormone levels

We studied plasma ghrelin and GH concentrations over a 24-h period in young healthy men and women and in patients with acromegaly. Healthy subjects were restudied after administration of GH-lowering agents, octreotide or GHRH antagonist. Ghrelin concentrations in women studied during the late follicular stage of the cycle were about 3-fold higher than in men. Suppression of GH secretion by GHRH antagonist did not alter ghrelin concentration profiles. In the presence of high GH levels (acromegaly), ghrelin levels were similar to those found in healthy men. Administration of somatostatin analog octreotide suppressed both GH and ghrelin concentration profiles. We conclude that: 1) ghrelin secretion is sexually dimorphic in humans, with women in the late follicular stage having higher levels than men; 2) ghrelin secretion is suppressed by somatostatin; and 3) GH has no influence over ghrelin secretion.     

Glycosaminoglycans and PDGF Signaling in Mesenchymal Cells

Platelet derived growth factor (PDGF) is involved in the autocrine growth stimulation of normal and malignant cells, the stimulation of angiogenesis, and the recruitment and regulation of tumor fibroblasts. PDGF has been shown to physically interact with glycosaminoglycans which are abundant in the extracellular microenvironment. The present review discusses the effects of glycosaminoglycans on the functions mediated by the PDGF on cells of mesenchymal origin. Recent studies have demonstrated that both soluble and surface bound glycosaminoglycan chains can modulate PDGF-BB isoform signaling depending on the cell type. These data demonstrated that the microenvironment rich in GAGs/PGs is able to significantly modify the cellular response to PDGF-BB signaling in a critical way for cell growth and differentiation.     

MRI and dual-energy CT fusion anatomic imaging in Ru-106 ophthalmic brachytherapy

PurposeBrachytherapy with Ru-106 is widely used for the treatment of intraocular tumors, and its efficacy depends on the accuracy of radioactive plaque placement. Ru-106 plaques are MRI incompatible and create severe metal artifacts on conventional CT scans. Dual-energy CT scans (DECT) may be used to suppress such artifacts. This study examines the possibility of creating fusion images from MRI scans (preoperatively) and DECT scans (with the plaque in place) as a tool for confirming the anatomic accuracy of plaque placement.Methods and MaterialsSix patients with intraocular lesions (5 with choroidal melanoma and 1 with a retinal vasoproliferative lesion) were included. Fusion images of preoperative MRI scans and DECT scans with the plaque in place were created with the Demo version of the ImFusion suite (ImFusion GmbH, Munchen Germany). Clearance margins between the tumor and plaque edge in axial, transverse, and coronal planes as well as the elevation of the posterior plaque edge from the sclera were recorded and associated with the location of the lesion.ResultsPlaque-tumor clearance margins for transverse, sagittal, and coronal planes were higher for anteriorly located lesions (5.13 mm ± 0.11 [5.0–5.2], 5.10 mm ± 0.26 [4.9–5.4], and 5.33 mm ± 0.45 [4.9–5.8] respectively) than for posteriorly located lesions (4.16 mm ± 1.44 [2.5–5.1], 4.13 mm ± 1.42 [2.5–5.1], and 4.2 mm ± 1.21 [2.8–5.0], respectively). The elevation of the posterior plaque edge from the sclera was 0.33 mm ± 0.28 [0–0.5] and 0.63 mm ± 0.60 [0.7–1.2] for posterior and anterior lesions, respectively.ConclusionsFusion images between DECT and MRI scans may be used as a tool to confirm the accuracy of Ru-106 plaque placement in relation with the intraocular tumors in ophthalmic brachytherapy.     

Emerging treatment strategies for COVID-19 infection

Clinical and Experimental Medicine - The new type of coronavirus (COVID-19), SARS-CoV-2 originated from Wuhan, China and has led to a worldwide pandemic. COVID-19 is a novel emerging infectious...     

Tumors of the labial mucosa: a retrospective study of 1045 biopsies

Background To investigate the relative frequency of localized mucosal swellings of the upper and lower labial mucosa, the clinical-pathological diagnosis agreement and whether patient’s age and gender and tumor’s site and size may raise the suspicion of neoplasm. Material and Methods Retrospective analysis was performed on upper or lower labial mucosal tumors, histopathologically diagnosed between 2009-2018. The diagnostic categories developmental/reactive tumors, benign and malignant neoplasms were associated with patient’s age and gender and tumor’s site and size; clinical-pathological diagnosis agreement was, also, evaluated. Results Overall, 1000 (95.7%) developmental/reactive tumors, 35 (3.3%) benign and 10 (1%) malignant neoplasms were found. Upper/lower lip tumor ratio was 0.14:1. The diagnostic category was significantly associated with age (p<0.0001), site (p<0.0001) and diameter (p<0.0001). Age ≥60 years, tumor’s location on the upper lip and diameter >1cm were independent predictors for neoplasms. Patients presenting 2 or 3 of these variables were 20.2 times (p < 0.0001) or 33.6 times (p <0.0001), respectively, more likely to have a neoplasm. Complete/partial agreement between clinical and pathological diagnosis was seen in 96.3% of the cases. Conclusions Most lip tumors involve the lower lip and are reactive, but upper lip tumors measuring >1cm in patients≥60 years have significantly higher probability to be neoplasms. Key words:Lip, tumor, neoplasm, carcinoma, cyst.