Neu-Laxova Syndrome,an Inborn Error of Serine Metabolism,Is Caused by Mutations in PHGDH

Neu-Laxova syndrome (NLS) is a rare autosomal-recessive disorder characterized by severe fetal growth restriction, microcephaly, a distinct facial appearance, ichthyosis, skeletal anomalies, and perinatal lethality. The pathogenesis of NLS remains unclear despite extensive clinical and pathological phenotyping of the >70 affected individuals reported to date, emphasizing the need to identify the underlying genetic etiology, which remains unknown. In order to identify the cause of NLS, we conducted a positional-mapping study combining autozygosity mapping and whole-exome sequencing in three consanguineous families affected by NLS. Surprisingly, the NLS-associated locus identified in this study was solved at the gene level to reveal mutations in PHGDH, which is known to be mutated in individuals with microcephaly and developmental delay. PHGDH encodes the first enzyme in the phosphorylated pathway of de novo serine synthesis, and complete deficiency of its mouse ortholog recapitulates many of the key features of NLS. This study shows that NLS represents the extreme end of a known inborn error of serine metabolism and highlights the power of genomic sequencing in revealing the unsuspected allelic nature of apparently distinct clinical entities.     

First report on the use of moderately halophilic bacteria against stem canker of greenhouse tomatoes caused byBotrytis cinerea

Experiments were conducted to study the effect of moderately halophilic bacteria isolated from different Tunisian Sebkhas (hypersaline soils), on stem canker caused byBotrytis cinerea on tomato plants grown under greenhouse conditions. Treatments performed with moderately halophilic isolates ofBacillus subtilis J9 andHalomonas sp. K2-5 significantly reduced stem lesion expansion byB. cinerea on tomato plants under greenhouse conditions. The use of such bacteria may constitute an important alternative to synthetic fungicides, which failed to suppress the development of the fungal pathogen.     

Evaluation of conformational changes in diabetes‐associated mutation in insulin a chain: A molecular dynamics study

Insulin plays a central role in the regulation of metabolism in humans. Mutations in the insulin gene can impair the folding of its precursor protein, proinsulin, and cause permanent neonatal‐onset diabetes mellitus known as Mutant INS‐gene induced Diabetes of Youth (MIDY) with insulin deficiency. To gain insights into the molecular basis of this diabetes‐associated mutation, we perform molecular dynamics simulations in wild‐type and mutant (Cys^A7 to Tyr or C(A7)Y) insulin A chain in aqueous solutions. The C(A7)Y mutation is one of the identified mutations that impairs the protein folding by substituting the cysteine residue which is required for the disulfide bond formation. A comparative analysis reveals structural differences between the wild‐type and the mutant conformations. The analyzed mutant insulin A chain forms a metastable state with major effects on its N‐terminal region. This suggests that MIDY mutant involves formation of a partially folded intermediate with conformational change in N‐terminal region in A chain that generates flexible N‐terminal domain. This may lead to the abnormal interactions with other proinsulins in the aggregation process. Proteins 2015; 83:662–669. © 2015 Wiley Periodicals, Inc.     

Bedside evaluation of the resistance of large and medium pulmonary veins in various lung diseases.

To evaluate the contribution of large and medium pulmonary veins to the total pulmonary vascular resistance in various human lung diseases, we compared in 64 patients the pulmonary arterial proximal wedge pressure (Ppw), obtained when the balloon of a 7F pulmonary artery catheter was inflated with 1.5 ml air, with the distal wedge pressure (Pdw), obtained after the tip of the catheter was advanced until wedged in a small artery without balloon inflation. Ppw, reflecting the pressure in a large pulmonary vein, approximates the left atrial pressure, whereas Pdw reflects the pressure in a smaller pulmonary vein. Pdw was greater than Ppw in all 64 patients. The Pdw-Ppw gradient was 1.1 +/- 0.5 mmHg in nine patients with normal lungs and was significantly higher in 13 patients with chronic congestive heart failure (3.8 +/- 0.8 mmHg, P less than 0.01) and in 22 patients with adult respiratory distress syndrome (3.8 +/- 0.8 mmHg; P less than 0.01), but not in 20 patients with chronic obstructive pulmonary disease (1.8 +/- 0.7 mmHg). The distribution of the pulmonary vascular resistance was clearly different among the four groups. The fraction of the total pulmonary vascular resistance attributable to large and medium pulmonary veins was significantly increased (P less than 0.01) in adult respiratory distress syndrome (27.5 +/- 12%) and cardiac patients (27.5 +/- 9%) compared with patients with chronic obstructive pulmonary disease (13 +/- 5%) and normal lungs (13.5 +/- 6%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification and molecular docking of novel ACE inhibitory peptides from protein hydrolysates of shrimp waste

The effect of enzymatic hydrolysis by Savinase on the interfacial properties and antihypertensive activity of shrimp waste proteins was evaluated. The physicochemical characterization, interfacial tension, and surface characteristics of shrimp waste protein hydrolysates (SWPH) using different enzyme/substrate (E/S) (SWPH₅ (SWPH using E/S = 5), SWPH₁₅ (SWPH using E/S = 15), and SWPH₄₀ (SWPH using E/S = 40)) were also studied. SWPH₅, SWPH₁₅, and SWPH₄₀ had an isoelectric pH around 2.07, 2.17, and 2.54 respectively. SWPH₅ exhibited the lowest interfacial tension (68.96 mN/m) followed by SWPH₁₅ (69.36 mN/m) and SWPH₄₀ (70.29 mN/m). The in vitro ACE inhibitory activity of shrimp waste protein hydrolysates showed that the most active hydrolysate was obtained using an enzyme/substrate of 15 U/mg (SWPH₁₅). SWPH₁₅ had a lower IC₅₀ value (2.17 mg/mL) than that of SWPH₅ and SWPH₄₀ (3.65 and 5.7 mg/mL, respectively). This hydrolysate was then purified and characterized. Fraction F1 separated by Sephadex G25 column which presents the best ACE inhibition activity was then separated by reversed‐phase high performance liquid chromatography. Four ACE inhibitory peptides were identified and their molecular masses and amino acid sequences were determined using ESI–MS and ESI–MS/MS, respectively. The structures of the most potent peptides were SSSKAKKMP, HGEGGRSTHE, WLGHGGRPDHE, and WRMDIDGDIMISEQEAHQR. The structural modeling of anti‐ACE peptides from shrimp waste through docking simulations results showed that these peptides bound to ACE with high affinity.     

Inflammatory cytokines and metabolic responses to high-intensity intermittent training: effect of the exercise intensity

To examine the effects of two high-intensity intermittent training (HIIT) programs of varying intensities (100% vs. 110% of maximal aerobic velocity [MAV]) on metabolic, hormonal and inflammatory markers in young men. Thirty-seven active male volunteers were randomly assigned into: HIIT experimental groups (100% MAV [EG₁₀₀, n = 9] and 110% MAV [EG₁₁₀, n = 9]) and a control groups (CG₁₀₀, n = 9 and CG₁₁₀, n = 9). Particpants performed high intesity intermittent exercise test (HIIE) at 100% or 110% MAV. Venous blood samples were obtained before, at the end of HIIE and at 15 min of recovery, and before and after 8 weeks of HIIT programs. After training, Glucose was lower (p < 0.01) in EG₁₀₀ (d = 0.72) and EG₁₁₀ (d = 1.20) at the end of HIIE, and at 15 min recovery only in EG₁₁₀ (d = 0.95). After training, Insulin and Cortisol were lower than before training in EG₁₀₀ and EG₁₁₀ at the end of HIIE (p < 0.001). After HIIT, IL-6 deceased (p < 0.001) in EG₁₀₀ (d = 1.43) and EG₁₁₀ (d = 1.56) at rest, at the end of HIIE (d = 1.03; d = 1.75, respectively) and at 15 min of recovery (d = 0.88;d = 1.7, respectively). This decrease was more robust (p < 0.05) in EG₁₁₀ compared to EG₁₀₀. After HIIT, TNF-α deceased (p < 0.001) in EG₁₀₀ (d = 1.43) and EG₁₁₀ (d = 0.60) at rest, at the end of HIIE (0.71 < d < 0.98) and at 15 min of recovery (0.70 < d < 2.78). HIIT with 110% MAV is more effective in young males on the improvements of some metabolic (Glucose), hormonal (Cortisol) and inflammatory (IL-6) markers at rest, at the end of HIIE and 15 min of recovery than training at 100 % MAV.     

Medication Possession Ratio Associated with Short-Term Virologic Response in Individuals Initiating Antiretroviral Therapy in Namibia

The visual-analogue scale (VAS), Likert item (rating scale), pills identification test (PIT), and medication possession ratio (MPR) provide estimates of antiretroviral therapy (ART) adherence which correlate with HIV viral suppression. These simple adherence measures are inexpensive and easy to administer; however, require validation and adjustment prior to implementation. The objective of this study was to define the optimal adherence assessment measure in Namibia to identify patients at risk for sub-optimal adherence and poor virologic response 6 months after ART initiation. We conducted a cross-sectional survey in HIV-infected adults receiving ART for 6–12 months prior to the adherence assessment. Adherence measures included 30-day VAS, 30-day Likert item, self-reported treatment interruptions, PIT, and MPR. Association of adherence measures with 6-month HIV-1 RNA level was assessed using two thresholds (1000 copies/mL and 5000 copies/mL). Adherence was assessed in 236 patients, mean age 37.3 years, 54% female. Mean adherence was 98.1% by 30-day VAS, 84.7% by 30-day Likert item, 97.0% by self-reported treatment interruptions, 90.6% by PIT, and 98.8% by MPR. Agreement between adherence measures was poor using kappa statistic. 76% had HIV-1 RNA <1000 copies/ml, and 88% had HIV-1 RNA <5000 copies/ml. MPR (continuous) was associated with viral suppression <5000 copies/ml (p = 0.036). MPR <75% was associated with virologic failure at ≥5000 copies/ml with OR 3.89 (1.24, 12.21), p = 0.013. Adherence was high with all measures. Only MPR, was associated with short-term virologic response, suggesting its cross-culturally utility for early identification of patients at high risk for virologic failure.     

Enhanced SPR Sensitivity with Nano-Micro-Ribbon Grating—an Exhaustive Simulation Mapping

In this study, we theoretically investigate the sensing potential of 2D nano- and micro-ribbon grating structuration on the surface of Kretschmann-based surface plasmon resonance (SPR) biosensors when they are employed for detection of biomolecular binding events. Numerical simulations were carried out by employing a model based on the hybridization of two classical methods, the Fourier modal method and the finite element method. Our calculations confirm the importance of light manipulation by means of structuration of the plasmonic thin film surfaces on the nano- and micro-scales. Not only does it highlight the geometric parameters that allow the sensitivity enhancement compared with the response of the conventional SPR biosensor based on a flat surface but also describes the transition from the regime where the propagating surface plasmon mode dominates to the regime where the localized surface plasmon mode dominates. An exhaustive mapping of the biosensing potential of the 2D nano- and micro-structured biosensors surface is presented, varying the structural parameters related to the ribbon grating dimensions, i.e., the widths and thicknesses. The nano- and micro-structuration also leads to the creation of regions on biosensor chips that are characterized by strongly enhanced electromagnetic (EM) fields. New opportunities for further improving the sensitivity are offered if localization of biomolecules can be carried out in these regions of high EM fields. The continuum of nano- and micro-ribbon structured biosensors described in this study should prove a valuable tool for developing sensitive and reliable 2D-structured plasmonic biosensors.     

Whole Exome Sequencing Identifies Mutations in Usher Syndrome Genes in Profoundly Deaf Tunisian Patients

Usher syndrome (USH) is an autosomal recessive disorder characterized by combined deafness-blindness. It accounts for about 50% of all hereditary deafness blindness cases. Three clinical subtypes (USH1, USH2, and USH3) are described, of which USH1 is the most severe form, characterized by congenital profound deafness, constant vestibular dysfunction, and a prepubertal onset of retinitis pigmentosa. We performed whole exome sequencing in four unrelated Tunisian patients affected by apparently isolated, congenital profound deafness, with reportedly normal ocular fundus examination. Four biallelic mutations were identified in two USH1 genes: a splice acceptor site mutation, c.2283-1G>T, and a novel missense mutation, c.5434G>A (p.Glu1812Lys), in MYO7A, and two previously unreported mutations in USH1G, i.e. a frameshift mutation, c.1195_1196delAG (p.Leu399Alafs*24), and a nonsense mutation, c.52A>T (p.Lys18*). Another ophthalmological examination including optical coherence tomography actually showed the presence of retinitis pigmentosa in all the patients. Our findings provide evidence that USH is under-diagnosed in Tunisian deaf patients. Yet, early diagnosis of USH is of utmost importance because these patients should undergo cochlear implant surgery in early childhood, in anticipation of the visual loss.