Myoclonus in mitochondrial disorders

Myoclonus is a possible manifestation of mitochondrial disorders, and its presence is considered, in association with epilepsy and the ragged red fibers, pivotal for the syndromic diagnosis of MERRF (myoclonic epilepsy with ragged red fibers). However, its prevalence in mitochondrial diseases is not known. The aims of this study are the evaluation of the prevalence of myoclonus in a big cohort of mitochondrial patients and the clinical characterization of these subjects. Based on the database of the “Nation‐wide Italian Collaborative Network of Mitochondrial Diseases,” we reviewed the clinical and molecular data of mitochondrial patients with myoclonus among their clinical features. Myoclonus is a rather uncommon clinical feature of mitochondrial diseases (3.6% of 1,086 patients registered in our database). It is not strictly linked to a specific genotype or phenotype, and only 1 of 3 patients with MERRF harbors the 8344A>G mutation (frequently labeled as “the MERRF mutation”). Finally, myoclonus is not inextricably linked to epilepsy in MERRF patients, but more to cerebellar ataxia. In a myoclonic patient, evidences of mitochondrial dysfunction must be investigated, even though myoclonus is not a common sign of mitochondriopathy. Clinical, histological, and biochemical data may predict the finding of a mitochondrial or nuclear DNA mutation. Finally, this study reinforces the notion that myoclonus is not inextricably linked to epilepsy in MERRF patients, and therefore the term “myoclonic epilepsy” seems inadequate and potentially misleading. © 2014 International Parkinson and Movement Disorder Society     

CMV-Specific Cell-Mediated Immunity in Immunocompetent Adults with Primary CMV Infection: A Case Series and Review of the Literature

Cytomegalovirus-specific cell-mediated immunity (CMV-CMI) in actively infected healthy immunocompetent hosts has been poorly investigated. Conversely, correlates of maternal protective immunity for the fetus after primary infection in pregnancy continue to be studied. The kinetics and magnitude of CMV-specific CMI in immunocompetent primary CMV-infected adults are described. A literature review on CMV-CMI in primarily infected pregnant women and its correlation to the risk of vertical virus transmission is included. Immunological measurements after infection were performed by enzyme-linked ImmunoSPOT assay enumerating IFN-γ secreting CMV-specific T cells, at a single cell level, upon in vitro stimulation with viral antigens. Simultaneously, serological and virological profiles of infected patients were investigated. Patients displayed mild-to-moderate clinical and laboratory profiles for infection, and all showed positive EliSpot results in the early stage of infection (<20 days after onset). The virus-CMI was strong in the majority of patients (58.8%) in which the lowest CMV-DNAemia levels (<300 copies/mL) were detected. Significantly higher viral loads were observed in patients with weak CMV-CMI at the same time-point post-infection (up to 15,104 copies/mL; p < 0.001). T cell response magnitudes to IE-1 and pp65-UL83 peptides were overlapping and stable over time. In these case series, the early presence of CMV-CMI was probably pivotal in controlling viral replication and led to spontaneous viral clearance.     

From microbiota toward gastro-enteropancreatic neuroendocrine neoplasms: Are we on the highway to hell?

Gut microbiota is represented by different microorganisms that colonize the intestinal tract, mostly the large intestine, such as bacteria, fungi, archaea and viruses. The gut microbial balance has a key role in several functions. It modulates the host’s metabolism, maintains the gut barrier integrity, participates in the xenobiotics and drug metabolism, and acts as protection against gastro-intestinal pathogens through the host’s immune system modulation. The impaired gut microbiota, called dysbiosis, may be the result of an imbalance in this equilibrium and is linked with different diseases, including cancer. While most of the studies have focused on the association between microbiota and gastrointestinal adenocarcinomas, very little is known about gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs). In this review, we provide an overview concerning the complex interplay between gut microbiota and GEP NENs, focusing on the potential role in tumorigenesis and progression in these tumors.

     

Prevalence of anti-FVIII antibodies in severe haemophilia A patients with inversion of intron 22

The aim of our study was to investigate whether haemophilia A patients with inversion of intron 22 are at high risk for non-inhibitory anti-FVIII antibodies development detected by ELISA. It is known that patients with severe forms of haemophilia A are more likely to develop anti-FVIII antibodies. The incidence of inhibitory anti-FVIII antibodies in patients with factor VIII gene inversion has been extensively evaluated, but if this defect has to be considered a predisposing factor is still debatable. Non-inhibitory anti-FVIII antibodies are attracting interest, due to the potential influence on FVIII half-life. Our data show that FVIII gene inversion was a major predisposing factor for anti-FVIII antibodies development.     

Effectiveness of intravenous propafenone for conversion of recent-onset atrial fibrillation: A placebo-controlled study

To evaluate the efficacy of propafenone in converting recent-onset atrial fibrillation (AF) lasting <7 days, 182 patients were treated intravenously with propafenone (Group 1, n = 98) and with placebo 0.9% saline solution (Group 2, n = 84) in a double blind study. The treatment was continued until sinus rhythm (SR) was restored, but for no more than 24 h. Eighty-nine patients treated with propafenone (90.8%) and 27 patients treated with placebo (32.1%) responded to the treatment and SR was restored (p < 0.0005). The mean time for SR restoration was 2.51± 2.77 h in Group 1, and 17.15± 7.8 h in Group 2 (p < 0.0005). In both groups the patients in whom SR was not restored (nonresponders) had larger left atrial size and longer duration of AF than responders at the onset of the arrhythmia. Nonresponders in Group 1 showed a decrease in mean ventricular rate (MVR) from 143± 16 to 101± 18 (p < 0.0005), while in the nonresponders in Group 2 no reduction of MVR was observed. Two patients whose SR was restored with propafenone had sinus standstill lasting 3.4 and 3.8 s, respectively. Propafenone used intravenously is an effective, quick, and safe drug for treating AF. Moreover, it significantly reduces MVR in nonresponders.     

Is there a difference in phenotype between males and females with non-transfusion-dependent thalassemia? A cross-sectional evaluation

Objectives: Non-transfusion-dependent thalassemia includes a variety of phenotypes and genotypes that rarely require regular transfusions. However, these patients can experience a wide range of complications. The objective of this retrospective study was to verify whether there is a significant difference in non-transfusion-dependent thalassemia-related complications and treatment among males and females.

Methods: We performed a re-analysis of samples evaluated in a previously published cross-sectional study, regarding 96 non-transfusion-dependent thalassemia patients followed at the ‘UOSD Malattie Rare del Globulo Rosso’ Centre of the Cardarelli Hospital in Naples, Italy.

Results: We found that females were more anemic than males, but there was no significant difference in prevalence of common complications among genders, except for hypogonadism. Furthermore, the transitory regular transfusions regimen in women who had been pregnant does not seem to have a significant impact on overall prognosis.

Discussion: In non-transfusion-dependent thalassemia patients, the lower levels of hemoglobin found in females do not seem to indicate a higher prevalence of complications.

Conclusion: This data should be considered in studies with experimental treatments aiming to correct anemia in patients with non-transfusion-dependent thalassemia. It should probably also be taken into account in order to set up different transfusion regimens among genders in transfusion-dependent patients.     

Glycation of human high density lipoprotein by methylglyoxal: Effect on HDL-paraoxonase activity

Objective

Methylglyoxal (MG), a reactive carbonyl compound formed primarily from triose phosphates, appears to be involved in the molecular mechanisms of diabetes, end-stage renal disease and neurodegenerative diseases. Methylglyoxal exerts several biological activities. Among these it promotes advanced glycation end products (AGEs), which are crucial in pathogenesis of human disease. Previous studies have demonstrated that MG reacts with proteins and compositional modifications reflect loss of biological activity. The aim of the study was to investigate the effect of in vitro MG-induced glycation on human high density lipoprotein (HDL) and on the activity of the enzyme paraoxonase-1 (PON1).

Methods

HDL was incubated in the absence or in the presence of MG (0.2 mmol/L and 1.0 mmol/L) (MG-HDL) for different times (3, 6, 24 h) at 37 ° C. We evaluated apoprotein compositional changes, in both control and MG treated HDL, using intrinsic fluorescence of tryptophan and monitoring the decrease of free amino groups. Furthermore we evaluated fluorescent advanced glycation end products (Ex = 370 nm, Em = 440 nm) and the activity of HDL-paraoxonase.

Results

We demonstrated that human HDL is susceptible to glycation by MG (0.2 mmol/L and 1 mmol/L). The decrease of free amino groups and of intrinsic fluorescence of tryptophan demonstrates HDL apoprotein modifications in HDL incubated with MG. The compositional changes are associated with a significant increase in fluorescent advanced glycation end products and with a significant decrease of paraoxonase-1 enzyme activity associated with the HDL surface.

Conclusions

HDL-associated paraoxonase is responsible for the anti-inflammatory and anti-oxidative properties of HDL and detoxification against homocysteine-thiolactone. Therefore, modifications of apoprotein composition and the decrease of paraoxonase-1 activity in MG-treated HDL could affect the protective effect exerted by HDL against oxidative damage and could contribute to complications in patients affected by diseases associated with aging and oxidative stress.