Cardiac function and metabolism in Type 2 diabetic mice after treatment with BM 17.0744, a novel PPAR-alpha activator

Hearts from diabetic db/db mice, a model of Type 2 diabetes, exhibit left ventricular failure and altered metabolism of exogenous substrates. Peroxisome proliferator-activated receptor-alpha (PPAR-alpha) ligands reduce plasma lipid and glucose concentrations and improve insulin sensitivity in db/db mice. Consequently, the effect of 4- to 5-wk treatment of db/db mice with a novel PPAR-alpha ligand (BM 17.0744; 25-38 mg x kg(-1) x day(-1)), commencing at 8 wk of age, on ex vivo cardiac function and metabolism was determined. Elevated plasma concentrations of glucose, fatty acids, and triacylglycerol (34.0 +/- 3.6, 2.0 +/- 0.4, and 0.9 +/- 0.1 mM, respectively) were reduced to normal after treatment with BM 17.0744 (10.8 +/- 0.6, 1.1 +/- 0.1, and 0.6 +/- 0.1 mM). Plasma insulin was also reduced significantly in treated compared with untreated db/db mice. Chronic treatment of db/db mice with the PPAR-alpha agonist resulted in a 50% reduction in rates of fatty acid oxidation, with a concomitant increase in glycolysis (1.7-fold) and glucose oxidation (2.3- fold). Correction of the diabetes-induced abnormalities in systemic and cardiac metabolism after BM 17.0744 treatment did not, however, improve left ventricular contractile function.     

Autosomal recessive dilated cardiomyopathy due to DOLK mutations results from abnormal dystroglycan O-mannosylation

Genetic causes for autosomal recessive forms of dilated cardiomyopathy (DCM) are only rarely identified, although they are thought to contribute considerably to sudden cardiac death and heart failure, especially in young children. Here, we describe 11 young patients (5-13 years) with a predominant presentation of dilated cardiomyopathy (DCM). Metabolic investigations showed deficient protein N-glycosylation, leading to a diagnosis of Congenital Disorders of Glycosylation (CDG). Homozygosity mapping in the consanguineous families showed a locus with two known genes in the N-glycosylation pathway. In all individuals, pathogenic mutations were identified in DOLK, encoding the dolichol kinase responsible for formation of dolichol-phosphate. Enzyme analysis in patients' fibroblasts confirmed a dolichol kinase deficiency in all families. In comparison with the generally multisystem presentation in CDG, the nonsyndromic DCM in several individuals was remarkable. Investigation of other dolichol-phosphate dependent glycosylation pathways in biopsied heart tissue indicated reduced O-mannosylation of alpha-dystroglycan with concomitant functional loss of its laminin-binding capacity, which has been linked to DCM. We thus identified a combined deficiency of protein N-glycosylation and alpha-dystroglycan O-mannosylation in patients with nonsyndromic DCM due to autosomal recessive DOLK mutations.     

Sources of dietary protein in relation to blood pressure in a general Dutch population

Background

Little is known about the relation of different dietary protein types with blood pressure (BP). We examined whether intake of total, plant, animal, dairy, meat, and grain protein was related to BP in a cross sectional cohort of 20,820 Dutch adults, aged 20–65 y and not using antihypertensive medication.

Design

Mean BP levels were calculated in quintiles of energy-adjusted protein with adjustment for age, sex, BMI, education, smoking, and intake of energy, alcohol, and other nutrients including protein from other sources. In addition, mean BP difference after substitution of 3 en% carbohydrates or MUFA with protein was calculated.

Results

Total protein and animal protein were not associated with BP (p_trend = 0.62 and 0.71 respectively), both at the expense of carbohydrates and MUFA. Systolic BP was 1.8 mmHg lower (p_trend<0.01) in the highest (>36 g/d) than in the lowest (<27 g/d) quintile of plant protein. This inverse association was present both at the expense of carbohydrates and MUFA and more pronounced in individuals with untreated hypertension (−3.6 mmHg) than in those with normal (+0.1 mmHg) or prehypertensive BP (−0.3 mmHg; p_interaction<0.01). Meat and grain protein were not related to BP. Dairy protein was directly associated with systolic BP (+1.6 mmHg, p_trend<0.01), but not with diastolic BP (p_trend = 0.24).

Conclusions

Total protein and animal protein were not associated with BP in this general untreated Dutch population. Plant protein may be beneficial to BP, especially in people with elevated BP. However, because high intake of plant protein may be a marker of a healthy diet and lifestyle in general, confirmation from randomized controlled trials is warranted.     

Requirements for effective antitumor responses of TCR transduced T cells

Adoptive transfer of TCR gene-modified T cells has been proposed as an attractive approach to target tumors for which it is difficult or impossible to induce strong tumor-specific T cell responses by vaccination. Whereas the feasibility of generating tumor Ag-specific T cells by gene transfer has been demonstrated, the factors that determine the in vivo effectiveness of TCR-modified T cells are largely unknown. We have analyzed the value of a number of clinically feasible strategies to enhance the antitumor potential of TCR modified T cells. These experiments reveal three factors that contribute greatly to the in vivo potency of TCR-modified T cells. First, irradiation-induced host conditioning is superior to vaccine-induced activation of genetically modified T cells. Second, increasing TCR expression through genetic optimization of TCR sequences has a profound effect on in vivo antitumor activity. Third, a high precursor frequency of TCR modified T cells within the graft is essential. Tumors that ultimately progress in animals treated with this optimized regimen for TCR-based adoptive cell transfer invariably display a reduced expression of the target Ag. This suggests TCR gene therapy can achieve a sufficiently strong selective pressure to warrant the simultaneous targeting of multiple Ags. The strategies outlined in this study should be of value to enhance the antitumor activity of TCR-modified T cells in clinical trials.     

Dietary hydroxy fatty acids are absorbed in humans: implications for the measurement of 'oxidative stress' in vivo.

Lipid peroxidation products formed in vivo or originating from the diet may lead to atherosclerosis. However, little is known about the absorption of these products in man. We studied the absorption of fat (30 g) containing 14-15 mg [U-13C]-labeled hydroxy or dihydroxy triglycerides in two groups of six apparently healthy women aged 40 +/- 2 years. Post-prandial 13C-labeled hydroxy fatty acid concentration increased in a pattern somewhat different from that of plasma triglycerides, with peak levels being reached between 4 and 6 h. However, the amount of 13C-labeled oxidized fat absorbed (area under the curve of plasma concentrations from 0 to 8 h) was related to that of plasma triglycerides: 13C hydroxy vs TG (r = 0.88, p <.02), and 13C dihydroxy vs TG (r = 0.85, p <.05). 13C monohydroxy triglycerides appeared to be absorbed to a greater extent than those of 13C dihydroxy triglycerides. Although low levels of 13C hydroxy lipids could be detected in fasting plasma after 24 h, concentrations were very low. Dietary lipid oxidation products are absorbed. The measurement of hydroxy fatty acids in plasma total lipids may not be a valid marker of lipid peroxidation in vivo when subjects are not fasting.     

Subcortical Structures in Humans Can Be Facilitated by Transcranial Direct Current Stimulation

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that alters cortical excitability. Interestingly, in recent animal studies facilitatory effects of tDCS have also been observed on subcortical structures. Here, we sought to provide evidence for the potential of tDCS to facilitate subcortical structures in humans as well. Subjects received anodal-tDCS and sham-tDCS on two separate testing days in a counterbalanced order. After stimulation, we assessed the effect of tDCS on two responses that arise from subcortical structures; (1) wrist and ankle responses to an imperative stimulus combined with a startling acoustic stimulus (SAS), and (2) automatic postural responses to external balance perturbations with and without a concurrent SAS. During all tasks, response onsets were significantly faster following anodal-tDCS compared to sham-tDCS, both in trials with and without a SAS. The effect of tDCS was similar for the dominant and non-dominant leg. The SAS accelerated the onsets of ankle and wrist movements and the responses to backward, but not forward perturbations. The faster onsets of SAS-induced wrist and ankle movements and automatic postural responses following stimulation provide strong evidence that, in humans, subcortical structures - in particular the reticular formation - can be facilitated by tDCS. This effect may be explained by two mechanisms that are not mutually exclusive. First, subcortical facilitation may have resulted from enhanced cortico-reticular drive. Second, the applied current may have directly stimulated the reticular formation. Strengthening reticulospinal output by tDCS may be of interest to neurorehabilitation, as there is evidence for reticulospinal compensation after corticospinal lesions.     

Offering ART refill through community health workers versus clinic-based follow-up after home-based same-day ART initiation in rural Lesotho: The VIBRA cluster-randomized clinical trial

BackgroundCommunity-based antiretroviral therapy (ART) dispensing by lay workers is an important differentiated service delivery model in sub-Sahara Africa. However, patients new in care are generally excluded from such models. Home-based same-day ART initiation is becoming widespread practice, but linkage to the clinic is challenging. The pragmatic VIBRA (Village-Based Refill of ART) trial compared ART refill by existing lay village health workers (VHWs) versus clinic-based refill after home-based same-day ART initiation.Methods and findingsThe VIBRA trial is a cluster-randomized open-label clinical superiority trial conducted in 249 rural villages in the catchment areas of 20 health facilities in 2 districts (Butha-Buthe and Mokhotlong) in Lesotho. In villages (clusters) randomized to the intervention arm, individuals found to be HIV-positive during a door-to-door HIV testing campaign were offered same-day ART initiation with the option of refill by VHWs. The trained VHWs dispensed drugs and scheduled clinic visits for viral load measurement at 6 and 12 months. In villages randomized to the control arm, participants were offered same-day ART initiation with clinic-based ART refill. The primary outcome was 12-month viral suppression. Secondary endpoints included linkage and 12-month engagement in care. Analyses were intention-to-treat. The trial was registered on ClinicalTrials.gov ({"type":"clinical-trial","attrs":{"text":"NCT03630549","term_id":"NCT03630549"}}NCT03630549). From 16 August 2018 until 28 May 2019, 118 individuals from 108 households in 57 clusters in the intervention arm, and 139 individuals from 130 households in 60 clusters in the control arm, were enrolled (150 [58%] female; median age 36 years [interquartile range 30–48]; 200 [78%] newly diagnosed). In the intervention arm, 48/118 (41%) opted for VHW refill. At 12 months, 46/118 (39%) participants in the intervention arm and 64/139 (46%) in the control arm achieved viral suppression (adjusted risk difference −0.07 [95% CI −0.20 to 0.06]; p = 0.256). Arms were similar in linkage (adjusted risk difference 0.03 [−0.10 to 0.16]; p = 0.630), but engagement in care was non-significantly lower in the intervention arm (adjusted risk difference −0.12 [−0.23 to 0.003]; p = 0.058). Seven and 0 deaths occurred in the intervention and control arm, respectively. Of the intervention participants who did not opt for drug refill from the VHW at enrollment, 41/70 (59%) mentioned trust or conflict issues as the primary reason. Study limitations include a rather small sample size, 9% missing viral load measurements in the primary endpoint window, the low uptake of the VHW refill option in the intervention arm, and substantial migration among the study population.ConclusionsThe offer of village-based ART refill after same-day initiation led to similar outcomes as clinic-based refill. The intervention did not amplify the effect of home-based same-day ART initiation alone. The findings raise concerns about acceptance and safety of ART delivered by lay health workers after initiation in the community.Trial registrationRegistered with Clinicaltrials.gov ({"type":"clinical-trial","attrs":{"text":"NCT03630549","term_id":"NCT03630549"}}NCT03630549).

Alain Amstutz and co-workers compare village- and clinic-based antiretroviral refills for people with HIV infection in Lesotho.