Beneficial effect of pyruvate therapy on Leigh syndrome due to a novel mutation in PDH E1α gene

Leigh syndrome (LS) is a progressive untreatable degenerating mitochondrial disorder caused by either mitochondrial or nuclear DNA mutations. A patient was a second child of unconsanguineous parents. On the third day of birth, he was transferred to neonatal intensive care units because of severe lactic acidosis. Since he was showing continuous lactic acidosis, the oral supplementation of dichloroacetate (DCA) was introduced on 31st day of birth at initial dose of 50 mg/kg, followed by maintenance dose of 25 mg/kg/every 12 h. The patient was diagnosed with LS due to a point mutation of an A-C at nucleotide 599 in exon 6 in the pyruvate dehydrogenase E1α gene, resulting in the substitution of aspartate for threonine at position 200 (N200T). Although the concentrations of lactate and pyruvate in blood were slightly decreased, his clinical conditions were deteriorating progressively. In order to overcome the mitochondrial or cytosolic energy crisis indicated by lactic acidosis as well as clinical symptoms, we terminated the DCA and administered 0.5 g/kg/day TID of sodium pyruvate orally. We analyzed the therapeutic effects of DCA or sodium pyruvate in the patient, and found that pyruvate therapy significantly decreased lactate, pyruvate and alanine levels, showed no adverse effects such as severe neuropathy seen in DCA, and had better clinical response on development and epilepsy. Though the efficacy of pyruvate on LS will be evaluated by randomized double-blind placebo-controlled study design in future, pyruvate therapy is a possible candidate for therapeutic choice for currently incurable mitochondrial disorders such as LS.     

Early virological response to HIV treatment: can we predict who is likely to experience subsequent treatment failure? Results from an observational cohort study,London, UK

Introduction : For people living with HIV, the first antiretroviral treatment (ART) regimen offers the best chance for a good virological response. Early identification of those unlikely to respond to first‐line ART could enable timely intervention and increase chances of a good initial treatment response. In this study we assess the extent to which the HIV RNA viral load (VL) at 1 and 3 months is predictive of first‐line treatment outcome at 6 months. Methods : All previously ART‐naive individuals starting ART at two London centres since 2000 with baseline (−180 to 3 days) VL >500 c/mL had a VL measurement between 6 and 12 months after starting ART, and at least one at month 1 (4–60 days) or month 3 (61–120 days) were included. Lack of treatment response was defined as (i) VL >200 copies/mL at 6 months or (ii) VL >200 copies/mL at 6 months or simultaneous switch in drugs from at least two different drug classes before 6 months. The association with VL measurements at 1 and 3 months post‐ART; change from pre‐ART in these values; and CD4 count measurements at 1 and 3 months were assessed using logistic regression models. The relative fit of the models was compared using the Akaike information criterion (AIC). Results : A total of 198 out of 3258 individuals (6%) experienced lack of treatment response at 6 months (definition i), increasing to 511 (16%) for definition (ii). Those with a 1‐month (day 4–60 window) VL of <1000, 1000–9999, 10,000–99,999 and >100,000 copies/ml had a 4%, 8%, 23% and 24% chance, respectively, of subsequently experiencing treatment non‐response at 6 months (definition (i)). When considering the 3‐month (day 61–120 window) VL, the chances of subsequently experiencing treatment non‐response were, respectively, 3%, 25%, 67% and 75%. Results were similar for definition (ii). Conclusions : Whilst 3‐month VL provides good discrimination between low and high risk of treatment failure, 1‐month VL does not. Presence of a VL >10,000 copies/ml after 3 months of ART is a cutoff above which individuals are at a sufficiently higher risk of non‐response that they may be considered for intervention.     

Is prostate cancer incidence worldwide linked to artificial light at night exposures? Review of earlier findings and analysis of current trends

Widespread use of artificial light at night (ALAN) might contribute to the global burden of hormone-dependent cancers. Previous attempts to verify this association in population-level studies have been sparse. Using GLOBOCAN, US-DMSP, and World Bank 2010–2012 databases, we studied the association between ALAN and prostate cancer (PC) incidence in 180 countries worldwide, controlling for several country-level confounders. The PC–ALAN association emerged marginally significant when year-2012 PC age-standardized rate data were compared with ALAN levels (t = 1.886, p < .1); this association was more significant (t > 2.7; p < .01) when only 110 countries with well-maintained cancer registries were analyzed. Along with other variables, ALAN explains up to 79% of PC ASR variability. PC–ALAN association appears to vary regionally, with the greatest deviations in Central Africa, Small Island Developing States, Southeast Asia, and Gulf States.     

The ability of various strains of <Emphasis Type="Italic">Staphylococcus</Emphasis> to create biofilms and their effect on cells of the human body

Research on staphylococci research is important because of their ability to cause such severe infections as soft tissue infections, endocarditis, sepsis, toxic shock syndrome, and food poisoning. Coagulase-positive Staphylococcus aureus is the main infection agent of intrahospital infections. This agent has many factors of pathogenicity, which are well known. Among the coagulase-negative staphylococcus (CNS) strains, S. haemolyticus and S. epidermidis are clinically important, because they cause infections in patients with weakened immune system. The mechanisms of the CNS pathogenicity are understood insufficiently. The goal of this work was to evaluate the potential pathogenicity of clinical CNS strains based on their capacity to form biofilms and their character of interaction with the human cells through an example of HT-29 cell culture. The research was carried out on the laboratory strain S. aureus ATCC 29213 and clinical strains S. haemolyticus SH39 and S. epidermidis SE 36-1, which were isolated from neonatal autopsy materials. The visual tests of biofilm formation by each strain and testing the impact of the strains on HT-29 cell culture were carried out in this work. Two CNS species form biofilms with a higher rate than S. aureus. Upon incubation for 2 h of HT-29 cells with the staphylococcus strains tested in this work, adhesion of bacteria on the cells’ surfaces was observed. The adhesion was most pronounced in the case of S. aureus ATCC 29213 and S. haemolyticus SH39. Upon 3 h of incubation with S. aureus ATCC 29213 and S. haemolyticus SH39, the destruction of a monolayer of HT-29 cells was observed. The incubation for 24 h with three strains tested in this work caused the complete destruction of the monolayer of HT-29 cells. The maximal toxic effect on HT-29 cells was inherent in S. haemolyticus SH39 strain. The cumulative results obtained in this work indicate the presence of the pathogenicity factors in S. haemolyticus SH39 strain, and their molecular nature needs to be researched further.     

Impact of estrogen receptor α on the tamoxifen response and prognosis in luminal-A-like and luminal-B-like breast cancer

Clinical and Experimental Medicine - The luminal-A-like and luminal-B-like breast cancer groups have distinct biological features that lead to differences in the treatment response and clinical...     

Therapeutic regimen of <Emphasis Type="SmallCaps">l</Emphasis>-arginine for MELAS: 9-year,prospective, multicenter,clinical research

Objective

To examine the efficacy and safety of the therapeutic regimen using oral and intravenous l-arginine for pediatric and adult patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS).

Methods

In the presence and absence of an ictus of stroke-like episodes within 6 h prior to efficacy assessment, we correspondingly conducted the systematic administration of oral and intravenous l-arginine to 15 and 10 patients with MELAS in two, 2-year, prospective, multicenter clinical trials at 10 medical institutions in Japan. Subsequently, patients were followed up for 7 years. The primary endpoint in the clinical trial of oral l-arginine was the MELAS scale, while that for intravenous l-arginine was the improvement rates of headache and nausea/vomiting at 2 h after completion of the initial intravenous administration. The relationships between the ictuses of stroke-like episodes and plasma arginine concentrations were examined.

Results

Oral l-arginine extended the interictal phase (p?=?0.0625) and decreased the incidence and severity of ictuses. Intravenous l-arginine improved the rates of four major symptoms—headache, nausea/vomiting, impaired consciousness, and visual disturbance. The maximal plasma arginine concentration was 167 μmol/L when an ictus developed. Neither death nor bedriddenness occurred during the 2-year clinical trials, and the latter did not develop during the 7-year follow-up despite the progressively neurodegenerative and eventually life-threatening nature of MELAS. No treatment-related adverse events occurred, and the formulations of l-arginine were well tolerated.

Conclusions

The systematic administration of oral and intravenous l-arginine may be therapeutically beneficial and clinically useful for patients with MELAS.

     

Parental mosaicism in epilepsies due to alleged de novo variants

Severe early onset epilepsies are often caused by de novo pathogenic variants. Few studies have reported the frequency of somatic mosaicism in parents of children with severe epileptic encephalopathies. Here we aim to investigate the frequency of mosaicism in the parents of children with epilepsy caused by alleged de novo variants. We tested parental genomic DNA derived from different tissues for 75 cases using targeted next‐generation sequencing. Five parents (6.6%) showed mosaicism at minor allele frequencies of 0.8%‐29% for the pathogenic variant detected in their offspring. Parental mosaicism was observed in the following genes: SCN1A, SCN2A, SCN8A, and STXBP1. One of the identified parents had epilepsy himself. Our results show that de novo events can occur already in parental tissue and in some cases can be detected in peripheral blood. Consequently, parents affected by low‐grade mosaicism are faced with an increased recurrence risk for transmitting the pathogenic variant, compared to the overall recurrence risk for a second affected child estimated at approximately 1%. However, testing for parental somatic mosaicism will help identifying those parents who truly are at higher risk and will significantly improve genetic counseling in the respective families.