WAVE2 Is a Vital Regulator in Myogenic Differentiation of Progenitor Cells through the Mechanosensitive MRTFA-SRF Axis

Skeletal myogenesis is an intricate process involving the differentiation of progenitor cells into myofibers, which is regulated by actin cytoskeletal dynamics and myogenic transcription factors. Although recent studies have demonstrated the pivotal roles of actin-binding proteins (ABPs) as mechanosensors and signal transducers, the biological significance of WAVE2 (Wiskott-Aldrich syndrome protein family member 2), an ABP essential for actin polymerization, in myogenic differentiation of progenitor cells has not been investigated. Our study provides important insights into the regulatory roles played by WAVE2 in the myocardin-related transcription factor A (MRTFA)-serum response factor (SRF) signaling axis and differentiation of myoblasts. We demonstrate that WAVE2 expression is induced during myogenic differentiation and plays a pivotal role in actin cytoskeletal remodeling in C2C12 myoblasts. Knockdown of WAVE2 in C2C12 cells reduced filamentous actin levels, increased globular actin accumulation, and impaired the nuclear translocation of MRTFA. Furthermore, WAVE2 depletion in myoblasts inhibited the expression and transcriptional activity of SRF and suppressed cell proliferation in myoblasts. Consequently, WAVE2 knockdown suppressed myogenic regulatory factors (i.e., MyoD, MyoG, and SMYD1) expressions, thereby hindering the differentiation of myoblasts. Thus, this study suggests that WAVE2 is essential for myogenic differentiation of progenitor cells by modulating the mechanosensitive MRTFA-SRF axis.

Role of Actin-Binding Proteins in Skeletal Myogenesis

Maintenance of skeletal muscle quantity and quality is essential to ensure various vital functions of the body. Muscle homeostasis is regulated by multiple cytoskeletal proteins and myogenic transcriptional programs responding to endogenous and exogenous signals influencing cell structure and function. Since actin is an essential component in cytoskeleton dynamics, actin-binding proteins (ABPs) have been recognized as crucial players in skeletal muscle health and diseases. Hence, dysregulation of ABPs leads to muscle atrophy characterized by loss of mass, strength, quality, and capacity for regeneration. This comprehensive review summarizes the recent studies that have unveiled the role of ABPs in actin cytoskeletal dynamics, with a particular focus on skeletal myogenesis and diseases. This provides insight into the molecular mechanisms that regulate skeletal myogenesis via ABPs as well as research avenues to identify potential therapeutic targets. Moreover, this review explores the implications of non-coding RNAs (ncRNAs) targeting ABPs in skeletal myogenesis and disorders based on recent achievements in ncRNA research. The studies presented here will enhance our understanding of the functional significance of ABPs and mechanotransduction-derived myogenic regulatory mechanisms. Furthermore, revealing how ncRNAs regulate ABPs will allow diverse therapeutic approaches for skeletal muscle disorders to be developed.

FLII Modulates the Myogenic Differentiation of Progenitor Cells via Actin Remodeling-Mediated YAP1 Regulation

The dynamic rearrangement of the actin cytoskeleton plays an essential role in myogenesis, which is regulated by diverse mechanisms, such as mechanotransduction, modulation of the Hippo signaling pathway, control of cell proliferation, and the influence of morphological changes. Despite the recognized importance of actin-binding protein Flightless-1 (FLII) during actin remodeling, the role played by FLII in the differentiation of myogenic progenitor cells has not been explored. Here, we investigated the roles of FLII in the proliferation and differentiation of myoblasts. FLII was found to be enriched in C2C12 myoblasts, and its expression was stable during the early stages of differentiation but down-regulated in fully differentiated myotubes. Knockdown of FLII in C2C12 myoblasts resulted in filamentous actin (F-actin) accumulation and inhibited Yes-associated protein 1 (YAP1) phosphorylation, which triggers its nuclear translocation from the cytoplasm. Consequently, the expressions of YAP1 target genes, including PCNA, CCNB1, and CCND1, were induced, and the cell cycle and proliferation of myoblasts were promoted. Moreover, FLII knockdown significantly inhibited the expression of myogenic regulatory factors, i.e., MyoD and MyoG, thereby impairing myoblast differentiation, fusion, and myotube formation. Thus, our findings demonstrate that FLII is crucial for the differentiation of myoblasts via modulation of the F-actin/YAP1 axis and suggest that FLII is a putative novel therapeutic target for muscle wasting.

Efficient symptomatic treatment and viral load reduction for children with influenza virus infection by nasal-spraying Bacillus spore probiotics

Influenza virus is a main cause of acute respiratory tract infections (ARTIs) in children. This is the first double-blind, randomized, and controlled clinical trial examining the efficacy of nasal-spraying probiotic LiveSpo Navax, which contains 5 billion of Bacillus subtilis and B. clausii spores in 5 mL, in supporting treatment of influenza viral infection in pediatric patients. We found that the nasal-spraying Bacillus spores significantly shortened the recovery period and overall treatment by 2 days and increased treatment effectiveness by 58% in resolving all ARTIs' symptoms. At day 2, the concentrations of influenza virus and co-infected bacteria were reduced by 417 and 1152 folds. Additionally, the levels of pro-inflammatory cytokines IL-8, TNF-α, and IL-6 in nasopharyngeal samples were reduced by 1.1, 3.7, and 53.9 folds, respectively. Compared to the standard control group, treatment regimen with LiveSpo Navax demonstrated significantly greater effectiveness, resulting in 26-fold reduction in viral load, 65-fold reduction in bacterial concentration, and 1.1-9.5-fold decrease in cytokine levels. Overall, nasal-spraying Bacillus spores can support the symptomatic treatment of influenza virus-induced ARTIs quickly, efficiently and could be used as a cost-effective supportive treatment for respiratory viral infection in general.Clinical trial registration no: NCT05378022 on 17/05/2022.

Saturated fatty acid-inducible miR-103-3p impairs the myogenic differentiation of progenitor cells by enhancing cell proliferation through Twinfilin-1/F-actin/YAP1 axis

Actin dynamics play an essential role in myogenesis through multiple mechanisms, such as mechanotransduction, cell proliferation, and myogenic differentiation. Twinfilin-1 (TWF1), an actin-depolymerizing protein, is known to be required for the myogenic differentiation of progenitor cells. However, the mechanisms by which they epigenetically regulate TWF1 by microRNAs under muscle wasting conditions related to obesity are almost unknown. Here, we investigated the role of miR-103-3p in TWF1 expression, actin filament modulation, proliferation, and myogenic differentiation of progenitor cells. Palmitic acid, the most abundant saturated fatty acid (SFA) in the diet, reduced TWF1 expression and impeded myogenic differentiation of C2C12 myoblasts, while elevating miR-103-3p levels in myoblasts. Interestingly, miR-103-3p inhibited TWF1 expression by directly targeting its 3'UTR. Furthermore, ectopic expression of miR-103-3p reduced the expression of myogenic factors, i.e., MyoD and MyoG, and subsequently impaired myoblast differentiation. We demonstrated that miR-103-3p induction increased filamentous actin (F-actin) and facilitated the nuclear translocation of Yes-associated protein 1 (YAP1), thereby stimulating cell cycle progression and cell proliferation. Hence, this study suggests that epigenetic suppression of TWF1 by SFA-inducible miR-103-3p impairs myogenesis by enhancing the cell proliferation triggered by F-actin/YAP1.

Induction of miR-665-3p Impairs the Differentiation of Myogenic Progenitor Cells by Regulating the TWF1-YAP1 Axis

Actin dynamics are known to orchestrate various myogenic processes in progenitor cells. Twinfilin-1 (TWF1) is an actin-depolymerizing factor that plays a crucial role in the differentiation of myogenic progenitor cells. However, little is known about the mechanisms underlying the epigenetic regulation of TWF1 expression and impaired myogenic differentiation in the background of muscle wasting. This study investigated how miR-665-3p affects TWF1 expression, actin filaments' modulation, proliferation, and myogenic differentiation in progenitor cells. Palmitic acid, the most prevalent saturated fatty acid (SFA) in food, suppressed TWF1 expression and inhibited the myogenic differentiation of C2C12 cells while increasing the level of miR-665-3p expression. Interestingly, miR-665-3p inhibited TWF1 expression by targeting TWF1 3'UTR directly. In addition, miR-665-3p accumulated filamentous actin (F-actin) and enhanced the nuclear translocation of Yes-associated protein 1 (YAP1), consequently promoting cell cycle progression and proliferation. Furthermore, miR-665-3p suppressed the expressions of myogenic factors, i.e., MyoD, MyoG, and MyHC, and consequently impaired myoblast differentiation. In conclusion, this study suggests that SFA-inducible miR-665-3p suppresses TWF1 expression epigenetically and inhibits myogenic differentiation by facilitating myoblast proliferation via the F-actin/YAP1 axis.

Mir-302a/TWF1 Axis Impairs the Myogenic Differentiation of Progenitor Cells through F-Actin-Mediated YAP1 Activation

Actin cytoskeleton dynamics have been found to regulate myogenesis in various progenitor cells, and twinfilin-1 (TWF1), an actin-depolymerizing factor, plays a vital role in actin dynamics and myoblast differentiation. Nevertheless, the molecular mechanisms underlying the epigenetic regulation and biological significance of TWF1 in obesity and muscle wasting have not been explored. Here, we investigated the roles of miR-302a in TWF1 expression, actin filament modulation, proliferation, and myogenic differentiation in C2C12 progenitor cells. Palmitic acid, the most prevalent saturated fatty acid (SFA) in the diet, decreased the expression of TWF1 and impeded myogenic differentiation while increasing the miR-302a levels in C2C12 myoblasts. Interestingly, miR-302a inhibited TWF1 expression directly by targeting its 3′UTR. Furthermore, ectopic expression of miR-302a promoted cell cycle progression and proliferation by increasing the filamentous actin (F-actin) accumulation, which facilitated the nuclear translocation of Yes-associated protein 1 (YAP1). Consequently, by suppressing the expressions of myogenic factors, i.e., MyoD, MyoG, and MyHC, miR-302a impaired myoblast differentiation. Hence, this study demonstrated that SFA-inducible miR-302a suppresses TWF1 expression epigenetically and impairs myogenic differentiation by facilitating myoblast proliferation via F-actin-mediated YAP1 activation.

Particle size as a driver of dewatering performance and its relationship to stabilization in fecal sludge

Poor and unpredictable dewatering performance of fecal sludge is a major barrier to sanitation provision in urban areas not served by sewers. Fecal sludge comprises everything that accumulates in onsite containments, and its characteristics are distinct from wastewater sludges and from feces. There is little fundamental understanding of what causes poor dewatering in fecal sludge. For the first time, we demonstrate that particle size distribution is a driver of dewatering performance in fecal sludge, and is associated with level of stabilization. Higher concentrations of small particles (<10 μm) and smaller median aggregate size (D50) corresponded to poor dewatering performance (measured by capillary suction time (CST) and supernatant turbidity) in field samples from Kenya and Uganda and in controlled laboratory anaerobic storage experiments. More stabilized fecal sludge (higher C/N, lower VSS/TSS) had better dewatering performance, corresponding to lower concentrations of small particles. Samples with the largest aggregates (D50 > 90 μm) had higher abundance of Gammaproteobacteria Pseudomonas, and samples with the smallest aggregates (D50 ≤ 50 μm) were characterized by higher abundance of Bacteroidetes Vadin HA17 and Rikenellaceae. Contrary to common perceptions, stabilization, particle size distribution, and dewatering performance were not dependent on time intervals between emptying of onsite containments or on time in controlled anaerobic storage experiments. Our results suggest that the stabilization process in onsite containments, and hence the dewaterability of sludge arriving at treatment facilities, is not dependent on time in containment but is more likely associated with specific microbial populations and the in-situ environmental conditions which promote or discourage their growth.

Kank1 Is Essential for Myogenic Differentiation by Regulating Actin Remodeling and Cell Proliferation in C2C12 Progenitor Cells

Actin cytoskeleton dynamics are essential regulatory processes in muscle development, growth, and regeneration due to their modulation of mechanotransduction, cell proliferation, differentiation, and morphological changes. Although the KN motif and ankyrin repeat domain-containing protein 1 (Kank1) plays a significant role in cell adhesion dynamics, actin polymerization, and cell proliferation in various cells, the functional significance of Kank1 during the myogenic differentiation of progenitor cells has not been explored. Here, we report that Kank1 acts as a critical regulator of the proliferation and differentiation of muscle progenitor cells. Kank1 was found to be expressed at a relatively high level in C2C12 myoblasts, and its expression was modulated during the differentiation. Depletion of Kank1 by siRNA (siKank1) increased the accumulation of filamentous actin (F-actin). Furthermore, it facilitated the nuclear localization of Yes-associated protein 1 (YAP1) by diminishing YAP1 phosphorylation in the cytoplasm, which activated the transcriptions of YAP1 target genes and promoted proliferation and cell cycle progression in myoblasts. Notably, depletion of Kank1 suppressed the protein expression of myogenic regulatory factors (i.e., MyoD and MyoG) and dramatically inhibited myoblast differentiation and myotube formation. Our results show that Kank1 is an essential regulator of actin dynamics, YAP1 activation, and cell proliferation and that its depletion impairs the myogenic differentiation of progenitor cells by promoting myoblast proliferation triggered by the F-actin-induced nuclear translocation of YAP1.

Edge magnetization and thermally induced spin current in nanostructured graphene

In this work, the magnetic states and thermally induced spin currents in graphene nanoflake sizes with different sizes and shapes have been investigated using Hubbard model combined with non-equilibrium Green's function method. In addition to the antiferromagnetic (AFM) state governed by the sizes, shapes, armchair bond densities, and Coulomb energy, our calculations have also pointed out the emergence of ferromagnetic (FM) and complex magnetic states when the gate voltage is invoked in the graphene nanoflakes. More prominently, by exploiting the geometric symmetry of the nanoflakes without external fields, a pure spin current and zero charge current are generated in spin caloritronic device when the graphene nanoflakes are both in the AFM and FM states. The formation of pure spin currents driven by temperature difference depends on the graphene nanoflakes' size, shape, temperature and gate voltage as well. The study also shows the outstanding advantages of diamond-shaped graphene nanoflakes in both magnetic properties and spin currents. This result paves the way for the possibility of practical applications of graphene materials in spintronics and spin caloritronics.

Case report: PICC line for a toddler with bilateral bidirectional Glenn shunt, Fontan circulation, and persistent left superior vena cava

Performing peripherally inserted central catheters for children with bilateral bidirectional Glenn shunt, Fontan circulation, and persistent left superior vena cava differs from those with normal central venous anatomy. This study presents two PICC procedures for a toddler with this condition to demonstrate an accurate PICC approach for such children.

Children with bilateral bidirectional Glenn shunt, Fontan procedure, and persistent left superior vena cava require an unique PICC placement approach to prevent unexpected complications. Hence, it is extremely important to provide nurses with knowledge about this altered central venous anatomy and explicitly outline in the PICC placement guidelines.

Mycomerge: Fabrication of Mycelium-Based Natural Fiber Reinforced Composites on a Rattan Framework

There is an essential need for a change in the way we build our physical environment. To prevent our ecosystems from collapsing, raising awareness of already available bio-based materials is vital. Mycelium, a living fungal organism, has the potential to replace conventional materials, having the ability to act as a binding agent of various natural fibers, such as hemp, flax, or other agricultural waste products. This study aims to showcase mycelium’s load-bearing capacities when reinforced with bio-based materials and specifically natural fibers, in an alternative merging design approach. Counteracting the usual fabrication techniques, the proposed design method aims to guide mycelium’s growth on a natural rattan framework that serves as a supportive structure for the mycelium substrate and its fiber reinforcement. The rattan skeleton is integrated into the finished composite product, where both components merge, forming a fully biodegradable unit. Using digital form-finding tools, the geometry of a compressive structure is computed. The occurring multi-layer biobased component can support a load beyond 20 times its own weight. An initial physical prototype in furniture scale is realized. Further applications in architectural scale are studied and proposed.

MiR-183-5p Induced by Saturated Fatty Acids Hinders Insulin Signaling by Downregulating IRS-1 in Hepatocytes

Excessive saturated fatty acids (SFA) uptake is known to be a primary cause of obesity, a widely acknowledged risk factor of insulin resistance and type 2 diabetes. Although specific microRNAs (miRNAs) targeting insulin signaling intermediates are dysregulated by SFA, their effects on insulin signaling and sensitivity are largely unknown. Here, we investigated the role of SFA-induced miR-183-5p in the regulation of proximal insulin signaling molecules and the development of hepatic insulin resistance. HepG2 hepatocytes treated with palmitate and the livers of high-fat diet (HFD)-fed mice exhibited impaired insulin signaling resulting from dramatic reductions in the protein expressions of insulin receptor (INSR) and insulin receptor substrate-1 (IRS-1). Differential expression analysis showed the level of miR-183-5p, which tentatively targets the 3'UTR of IRS-1, was significantly elevated in palmitate-treated HepG2 hepatocytes and the livers of HFD-fed mice. Dual-luciferase analysis showed miR-183-5p bound directly to the 3'UTR of IRS-1 and reduced IRS-1 expression at the post-transcriptional stage. Moreover, transfection of HepG2 hepatocytes with miR-183-5p mimic significantly inhibited IRS-1 expression and hindered insulin signaling, consequently inhibiting insulin-stimulated glycogen synthesis. Collectively, this study reveals a novel mechanism whereby miR-183-5p induction by SFA impairs insulin signaling and suggests miR-183-5p plays a crucial role in the pathogenesis of hepatic insulin resistance in the background of obesity.

MiR-141-3p regulates myogenic differentiation in C2C12 myoblasts via CFL2-YAP-mediated mechanotransduction

Skeletal myogenesis is essential to keep muscle mass and integrity, and impaired myogenesis is closely related to the etiology of muscle wasting. Recently, miR-141-3p has been shown to be induced under various conditions associated with muscle wasting, such as aging, oxidative stress, and mitochondrial dysfunction. However, the functional significance and mechanism of miR-141-3p in myogenic differentiation have not been explored to date. In this study, we investigated the roles of miR-141-3p on CFL2 expression, proliferation, and myogenic differentiation in C2C12 myoblasts. MiR-141-3p appeared to target the 3’UTR of CFL2 directly and suppressed the expression of CFL2, an essential factor for actin filament (F-actin) dynamics. Transfection of miR-141-3p mimic in myoblasts increased F-actin formation and augmented nuclear Yes-associated protein (YAP), a key component of mechanotransduction. Furthermore, miR-141-3p mimic increased myoblast proliferation and promoted cell cycle progression throughout the S and G2/M phases. Consequently, miR-141-3p mimic led to significant suppressions of myogenic factors expression, such as MyoD, MyoG, and MyHC, and hindered the myogenic differentiation of myoblasts. Thus, this study reveals the crucial role of miR-141-3p in myogenic differentiation via CFL2-YAP-mediated mechanotransduction and provides implications of miRNA-mediated myogenic regulation in skeletal muscle homeostasis.

Role of MiR-325-3p in the Regulation of CFL2 and Myogenic Differentiation of C2C12 Myoblasts

Skeletal myogenesis is required to maintain muscle mass and integrity, and impaired myogenesis is causally linked to the etiology of muscle wasting. Recently, it was shown that excessive uptake of saturated fatty acids (SFA) plays a significant role in the pathogenesis of muscle wasting. Although microRNA (miRNA) is implicated in the regulation of myogenesis, the molecular mechanism whereby SFA-induced miRNAs impair myogenic differentiation remains largely unknown. Here, we investigated the regulatory roles of miR-325-3p on CFL2 expression and myogenic differentiation in C2C12 myoblasts. PA impeded myogenic differentiation, concomitantly suppressed CFL2 and induced miR-325-3p. Dual-luciferase analysis revealed that miR-325-3p directly targets the 3'UTR of CFL2, thereby suppressing the expression of CFL2, a crucial factor for actin dynamics. Transfection with miR-325-3p mimic resulted in the accumulation of actin filaments (F-actin) and nuclear Yes-associated protein (YAP) in myoblasts and promoted myoblast proliferation and cell cycle progression. Consequently, miR-325-3p mimic significantly attenuated the expressions of myogenic factors and thereby impaired the myogenic differentiation of myoblasts. The roles of miR-325-3p on CFL2 expression, F-actin modulation, and myogenic differentiation suggest a novel miRNA-mediated regulatory mechanism of myogenesis and PA-inducible miR-325-3p may be a critical mediator between obesity and muscle wasting.

Comparative Transcriptome Analysis During the Seven Developmental Stages of Channel Catfish (Ictalurus punctatus) and Tra Catfish (Pangasianodon hypophthalmus) Provides Novel Insights for Terrestrial Adaptation

Tra catfish (Pangasianodon hypophthalmus), also known as striped catfish, is a facultative air-breather that uses its swim bladder as an air-breathing organ (ABO). A related species in the same order (Siluriformes), channel catfish (Ictalurus punctatus), does not possess an ABO and thus cannot breathe in the air. Tra and channel catfish serve as great comparative models for investigating possible genetic underpinnings of aquatic to land transitions, as well as for understanding genes that are crucial for the development of the swim bladder and the function of air-breathing in tra catfish. In this study, hypoxia challenge and microtomy experiments collectively revealed critical time points for the development of the air-breathing function and swim bladder in tra catfish. Seven developmental stages in tra catfish were selected for RNA-seq analysis based on their transition to a stage that could live at 0 ppm oxygen. More than 587 million sequencing clean reads were generated, and a total of 21,448 unique genes were detected. A comparative genomic analysis between channel catfish and tra catfish revealed 76 genes that were present in tra catfish, but absent from channel catfish. In order to further narrow down the list of these candidate genes, gene expression analysis was performed for these tra catfish-specific genes. Fourteen genes were inferred to be important for air-breathing. Of these, HRG, GRP, and CX3CL1 were identified to be the most likely genes related to air-breathing ability in tra catfish. This study provides a foundational data resource for functional genomic studies in air-breathing function in tra catfish and sheds light on the adaptation of aquatic organisms to the terrestrial environment.

MiR-96-5p Induced by Palmitic Acid Suppresses the Myogenic Differentiation of C2C12 Myoblasts by Targeting FHL1

Skeletal myogenesis is a multi-stage process that includes the cell cycle exit, myogenic transcriptional activation, and morphological changes to form multinucleated myofibers. Recent studies have shown that saturated fatty acids (SFA) and miRNAs play crucial roles in myogenesis and muscle homeostasis. Nevertheless, the target molecules and myogenic regulatory mechanisms of miRNAs are largely unknown, particularly when myogenesis is dysregulated by SFA deposition. This study investigated the critical role played by miR-96-5p on the myogenic differentiation in C2C12 myoblasts. Long-chain SFA palmitic acid (PA) significantly reduced FHL1 expression and inhibited the myogenic differentiation of C2C12 myoblasts but induced miR-96-5p expression. The knockdown of FHL1 by siRNA stimulated cell proliferation and inhibited myogenic differentiation of myoblasts. Interestingly, miR-96-5p suppressed FHL1 expression by directly targeting the 3’UTR of FHL1 mRNA. The transfection of an miR-96-5p mimic upregulated the expressions of cell cycle-related genes, such as PCNA, CCNB1, and CCND1, and increased myoblast proliferation. Moreover, the miR-96-5p mimic inhibited the expressions of myogenic factors, such as myoblast determination protein (MyoD), myogenin (MyoG), myocyte enhancer factor 2C (MEF2C), and myosin heavy chain (MyHC), and dramatically impeded differentiation and fusion of myoblasts. Overall, this study highlights the role of miR-96-5p in myogenesis via FHL1 suppression and suggests a novel regulatory mechanism for myogenesis mediated by miRNA in a background of obesity.

MiR-183-5p induced by saturated fatty acids regulates the myogenic differentiation by directly targeting FHL1 in C2C12 myoblasts

Skeletal myogenesis is a complex process that is finely regulated by myogenic transcription factors. Recent studies have shown that saturated fatty acids (SFA) can suppress the activation of myogenic transcription factors and impair the myogenic differentiation of progenitor cells. Despite the increasing evidence of the roles of miRNAs in myogenesis, the targets and myogenic regulatory mechanisms of miRNAs are largely unknown, particularly when myogenesis is dysregulated by SFA deposition. This study examined the implications of SFA-induced miR-183-5p on the myogenic differentiation in C2C12 myoblasts. Long-chain SFA palmitic acid (PA) drastically reduced myogenic transcription factors, such as myoblast determination protein (MyoD), myogenin (MyoG), and myocyte enhancer factor 2C (MEF2C), and inhibited FHL1 expression and myogenic differentiation of C2C12 myoblasts, accompanied by the induction of miR-183-5p. The knockdown of FHL1 by siRNA inhibited myogenic differentiation of myoblasts. Interestingly, miR-183-5p inversely regulated the expression of FHL1, a crucial regulator of skeletal myogenesis, by targeting the 3’UTR of FHL1 mRNA. Furthermore, the transfection of miR-183-5p mimic suppressed the expression of MyoD, MyoG, MEF2C, and MyHC, and impaired the differentiation and myotube formation of myoblasts. Overall, this study highlights the role of miR-183-5p in myogenic differentiation through FHL1 repression and suggests a novel miRNA-mediated mechanism for myogenesis in a background of obesity.

Inactivation of the bacterial pathogens Staphylococcus pseudintermedius and Acinetobacter baumannii by butanoic acid

AIMS

This study was performed to evaluate the efficacy of butanoic acid against bacterial pathogens including Acinetobacter baumannii and Staphylococcus pseudintermedius.

METHODS AND RESULTS

Vegetative bacteria were exposed to butanoic acid in vitro and log reduction was quantified using viable count assays. The maximum (8 and 9) log inactivation was determined by qualitatively assaying for growth/no-growth after a 48-h incubation (37°C). Membrane integrity after exposure to butanoic acid was determined by propidium iodide staining, scanning electron microscopy, membrane depolarization and inductively coupled plasma analysis. Cytosolic pH was measured by 5-(6-)carboxyfluorescein succinimidyl ester.

CONCLUSIONS

Inhibitory concentrations of butanoic acid ranged between 11 and 21 mmol l^-1 for Gram-positive and Gram-negative species tested. The maximum log reduction of A. baumannii was achieved with a 10-s exposure of 0·50 mol l^-1 of butanoic acid. Staphylococcus pseudintermedius required 0·40 mol l^-1 of butanoic acid to achieve the same level of reduction in the same time period. Inactivation was associated with membrane permeability and acidification of the cytosol.

SIGNIFICANCE AND IMPACT OF THE STUDY

Antibiotic resistance among bacterial pathogens necessitates the utilization of novel therapeutics for disinfection and biological control. These results may facilitate the development of butanoic acid as an effective agent against a broad-spectrum of antibiotic-resistant bacterial pathogens.

Autologous bilayered self-assembled skin substitutes (SASSs) as permanent grafts: a case series of 14 severely burned patients indicating clinical effectiveness

Split-thickness skin autografts (AGs) are the standard surgical treatment for severe burn injuries. However, the treatment of patients with substantial skin loss is limited by the availability of donor sites for skin harvesting. As an alternative to skin autografts, our research group developed autologous self-assembled skin substitutes (SASSs), allowing the replacement of both dermis and epidermis in a single surgical procedure. The aim of the study was to assess the clinical outcome of the SASSs as a permanent coverage for full-thickness burn wounds. Patients were recruited through the Health Canada's Special Access Program. SASSs were grafted on debrided full-thickness wounds according to similar protocols used for AGs. The graft-take and the persistence of the SASS epithelium over time were evaluated. 14 patients received surgical care with SASSs. The mean percentage of the SASS graft-take was 98 % (standard deviation = 5) at 5 to 7 d after surgery. SASS integrity persisted over time (average follow-up time: 3.2 years), without noticeable deficiency in epidermal regeneration. Assessment of scar quality (skin elasticity, erythema, thickness) was performed on a subset of patients. Non-homogeneous pigmentation was noticed in several patients. These results indicated that the SASS allowed the successful coverage of full-thickness burns given its high graft-take, aesthetic outcome equivalent to autografting and the promotion of long-term tissue regeneration. When skin donor sites are in short supply, SASSs could be a valuable alternative to treat patients with full-thickness burns covering more than 50 % of their total body surface area.

Hepatitis B surface antigen loss and sustained viral suppression in Asian chronic hepatitis B patients: A community-based real-world study

Community-based real-world outcomes on effectiveness of antiviral therapies for chronic hepatitis B virus (CHB) in Asians are limited. Whether hepatitis B surface antigen (HBsAg) loss correlates with undetectable virus and alanine aminotransferase (ALT) normalization on treatment or what predicts risk of seroreversion or detectable virus after stopping therapy is unclear. We aim to evaluate rates and predictors of HBsAg loss, seroconversion, ALT normalization and undetectable HBV DNA, including HBsAg seroreversion or re-emergence of HBV DNA among Asian CHB patients. We retrospectively evaluated 1072 CHB adults on antiviral therapy at two community gastroenterology clinics from 1997 to 2015. Rates of HBsAg loss, ALT normalization, achieving undetectable HBV DNA and developing surface antibody (anti-HBs) were stratified by HBeAg status. Following HBsAg loss, HBsAg seroreversion or re-emergence of detectable HBV DNA was analysed. With median treatment of 76.7 months, the overall rate of HBsAg loss was 4.58%, with similar HBsAg loss rates between HBeAg-positive and HBeAg-negative patients (4.44% vs 4.71%, P=.85) in a predominantly Asian population (98.1%). Among HBsAg loss patients, 33.3% developed anti-HBs, 95.8% achieved undetectable virus and 66.0% normalized ALT. No significant baseline or on-treatment predictors of HBsAg loss were observed. While six patients who achieved HBsAg loss had seroreversion with re-emergence of HBsAg positivity, viral load remained undetectable, demonstrating the sustainability of viral suppression. Among a large community-based real-world cohort of Asian CHB patients treated with antiviral therapy, rate of HBsAg loss was 4.58%. Despite only 33.3% of HBsAg loss patients achieving anti-HBs, nearly all patients achieved sustained undetectable virus.

Finding HOPE: Changes in depressive symptomology following relocation from distressed public housing

Many public housing residents suffer from poor mental health and depression, which may be a function of both socioeconomic deprivation and residing in disorderly, unstable, and disadvantaged neighborhoods. While not explicitly targeting mental health, the HOPE VI program may improve public housing residents' mental health by relocating them from distressed developments and into less-disadvantaged and disorderly neighborhoods. This paper examines post-relocation depressive symptomology among residents relocated from the Boulevard Homes public housing development in Charlotte, NC. Drawing on pre- and post-relocation surveys, as well as interviews with staff and case managers, we examine whether depressive symptomology - measured by the CES-D-10 - is associated with whether tenants relocate to other public housing or to private-market housing through the Housing Choice Voucher program. Further, we investigate whether social support, perceptions of safety, or objective neighborhood measures result in improvements in post-relocation depressive symptomology. We find that depressive symptomology substantially decreased following relocation, and those with higher CES-D-10 scores were more likely to move to other public housing rather than through the voucher program. Interviews with case managers suggest that some residents were fearful of leaving public housing and assuming the responsibilities of a private-market rental unit - e.g., basic maintenance and utility payments. Further, we find that reductions in post-relocation depressive symptomology are associated with greater perceptions of safety, greater social support in their new neighborhoods, and length of tenure at Boulevard Homes. Policy recommendations include expanding community-based mental health services, conducting pre-relocation mental health screenings, and providing additional relocation counseling to those suffering from depression.

Community-based real-world treatment outcomes of sofosbuvir/ledipasvir in Asians with chronic hepatitis C virus genotype 6 in the United States

Sofosbuvir/ledipasvir (SOF/LDV) is the first all-oral ribavirin-free treatment approved for chronic hepatitis C virus (HCV) genotype 6, offering a safe and highly efficacious treatment option. Large studies evaluating real-world outcomes of this regimen are lacking. We aim to evaluate real-world treatment outcomes for HCV genotype 6. A retrospective cohort study evaluated 65 adults (age ≥18) with chronic HCV genotype 6 treated with SOF/LDV without ribavirin at a community gastroenterology clinic in the United States from November 2014 to May 2016. Rates of undetectable virus at week 4 on treatment, at end of treatment (EOT) and SVR12 were stratified by the presence of cirrhosis and prior treatment (treatment naïve vs treatment experienced). Among 65 patients with chronic HCV genotype 6 treated with SOF/LDV (52.3% male, mean age 66.3 years [SD 9.7], 41.5% cirrhosis and 15.4% treatment experienced), 97.3% had undetectable virus at week 4 on treatment, 96.9% had undetectable virus at EOT and 95.3% achieved SVR12. SVR12 was 100% in females vs 91.2% in males, P=.096, and 92.3% in patients with cirrhosis vs 97.4% in those without cirrhosis, P=.347. Resistance testing of treatment failures was attempted but unsuccessful due to lack of conforming primers to define the possible resistance mutations. Among the largest U.S. community-based real-world cohort of Asian chronic HCV genotype 6 patients treated with all-oral SOF/LDV without ribavirin, SVR12 was similar to SVR12 reported in clinical trials, confirming the safety and effectiveness of this regimen and validating current HCV genotype 6 treatment guideline recommendations.

Arterial stiffness is elevated in normotensive type 2 diabetic patients with peripheral neuropathy

BACKGROUND AND AIMS

Arterial stiffness, a measure of macrovascular damage predictive of poor cardio-vascular outcomes, is strongly related to age and hypertension (HT). In diabetic patients peripheral neuropathy (PN) has been found to be associated with increased arterial stiffness, which might be due to the concomitant presence of HT. The aim of this study was to examine in type-2 diabetic patients, the relationship between arterial stiffness and presence or absence of PN and HT separately.

METHODS AND RESULTS

Arterial stiffness was measured with the gold standard carotid-femoral pulse wave velocity (PWV) in 447 type-2 diabetic subjects of whom 66% were hypertensive, 53% had PN, and 40% had both. Patients with PN were older, more often hypertensive and had higher PWV than those free of PN. Patients were separated according to the presence or absence of PN and HT. PWV values above the 90th percentile age- and blood pressure-adjusted reference range (PWV+) were different across these groups (p < 0.005) with the following respective prevalences: 27.2%, 53.4%, 33.3% and 30.6%. Only PWV+ was significantly associated with PN and hypertension in the interaction analysis.

CONCLUSION

Well controlled hypertensive patients did not have elevated arterial stiffness compared to normotensive patients. This might be due to anti-hypertensive treatment although our study design does not allow us to confirm it. A strong association between PN and arterial stiffness was only present in normotensive patients, suggesting that normotensive type 2 diabetic patients with PN and elevated arterial stiffness should be carefully managed to prevent future macrovascular complications.

The clinical utility of whole-exome sequencing in the context of rare diseases - the changing tides of medical practice

Whole-exome sequencing (WES) carries the potential to facilitate the identification of disease causing genes. This is particularly relevant concerning rare diseases, which proves particularly difficult for physicians to diagnose. However, the complexity of this technology renders its applicability onto the clinical setting uncertain. Our study thus aims to understand physicians' perspectives regarding the clinical utility of WES, particularly for providing a diagnosis for patients with rare diseases. Ten semi-structured interviews were conducted with physicians with experience and familiarity with WES, and the major themes that emerged from our interviews were (i) the relevance of WES in diagnosing patients with rare diseases (appropriateness); (ii) the cost-effectiveness of WES (accessibility), (iii) the practical issues related to the clinical implementation of WES (practicability); and (iv) ethical, legal and social issues (acceptability). Our study highlights how the clinical implementation of WES presents additional challenges where rare diseases are taken into consideration.

Decreased stroke volume−brachial pulse pressure ratio in patients with type 2 diabetes over 50 years: the role of peripheral neuropathy

BACKGROUND AND AIMS

To document the stroke volume to pulse pressure ratio (SV/PP, an index of total arterial compliance) and its correlates in patients with type 2 diabetes (T2DM) aged over 50 years whose peripheral neuropathy and silent myocardial ischemic (SMI) status were known.

METHODS AND RESULTS

A total of 360 patients with T2DM aged ≥ 50 years, without cardiac history or symptom, left ventricular systolic dysfunction, dilatation and hypokinesia, were retrospectively enrolled. The SV/PP was calculated from echocardiographic left ventricular measurements and brachial blood pressure at rest. Peripheral neuropathy was defined as the presence of any two or more of the following: neuropathic symptoms, decreased distal sensation, or decreased or absent ankle reflexes. SMI was defined as an abnormal stress myocardial scintigraphy and/or stress echocardiography. A low SV/PP ratio (<0.53 ml/m²/mmHg, first tertile) was associated with age, creatinine clearance, 24 h urinary albumin excretion rate, peripheral neuropathy, hypertension, serum total cholesterol and triglycerides levels (p < 0.05-0.0001). In multivariate analysis, age (OR 1.1 [1.0-1.2], p < 0.01), triglycerides (OR 1.5 [1.2-2.0], p = 0.01) and peripheral neuropathy (OR 2.2 [1.2-3.9], p = 0.009) were independently associated with a low SV/PP. The patients with peripheral neuropathy had lower SV (p < 0.01) and higher PP (p < 0.05) than those without, and only lower SV after adjustment for age and nephropathy. Similar results were obtained in the patients with and without SMI.

CONCLUSION

Peripheral neuropathy was independently associated with decreased SV/PP, mainly through decreased SV, in patients with T2DM over 50 years.

Hsp90 chaperones PPARγ and regulates differentiation and survival of 3T3-L1 adipocytes

Adipose tissue dysregulation has a major role in various human diseases. The peroxisome proliferator-activated receptor-γ (PPARγ) is a key regulator of adipocyte differentiation and function, as well as a target of insulin-sensitizing drugs. The Hsp90 chaperone stabilizes a diverse set of signaling 'client' proteins, thereby regulates various biological processes. Here we report a novel role for Hsp90 in controlling PPARγ stability and cellular differentiation. Specifically, we show that the Hsp90 inhibitors geldanamycin and novobiocin efficiently impede the differentiation of murine 3T3-L1 preadipocytes. Geldanamycin at higher concentrations also inhibits the survival of both developing and mature adipocytes, respectively. Further, Hsp90 inhibition disrupts an Hsp90-PPARγ complex, leads to the destabilization and proteasomal degradation of PPARγ, and inhibits the expression of PPARγ target genes, identifying PPARγ as an Hsp90 client. A similar destabilization of PPARγ and a halt of adipogenesis also occur in response to protein denaturing stresses caused by a single transient heat-shock or proteasome inhibition. Recovery from stress restores PPARγ stability and adipocyte differentiation. Thus, our findings reveal Hsp90 as a critical stress-responsive regulator of adipocyte biology and offer a potential therapeutic target in obesity and the metabolic syndrome.

The report of male gender and retinopathy status improves the current consensus guidelines for the screening of myocardial ischemia in asymptomatic type 2 diabetic patients

BACKGROUND AND AIMS

American Diabetes Association (ADA), French-speaking Societies for diabetes & cardiology (ALFEDIAM-SFC) and Cardiac Radionuclide Imaging (CRI) have proposed guidelines for the screening of silent myocardial ischemia (SMI). The aim of the study was to evaluate their diagnostic values and how to improve them.

METHODS AND RESULTS

731 consecutive type 2 diabetic patients with ≥1 additional risk factor were screened between 1992 and 2006 for SMI by stress myocardial scintigraphy and for silent coronary artery disease (CAD) by coronary angiography. A total of 215 (29.4%) patients had SMI, and 79 of them had CAD. ADA (Odds Ratio 1.7 [95% Confidence Interval: 1.2-2.5]; p < 0.05), ALFEDIAM-SFC (OR 1.5 [1.0-2.5], p < 0.05) and CRI criteria (OR 2.0 [1.4-2.8], p < 0.01) predicted SMI. Considering the presence of male gender and retinopathy added to the prediction of SMI allowed by ADA criteria (c statistic: area under the curve AROC 0.651 [0.605-0.697] versus 0.582 [0.534-0.630]), p < 0.01 and ALFEDIAM-SFC criteria (AROC 0.672 [0.620-0.719] versus 0.620 [0.571-0.670], p < 0.05). CRI prediction of SMI was improved by considering the presence of macroproteinuria and retinopathy (AROC 0.621 [0.575-0.667] versus 0.594 [0.548-0.641], p < 0.01). Severe retinopathy (OR 3.4 [1.2-9.4], p < 0.05), smoking habits (OR 2.1 [1.1-4.2], p < 0.05) and triglyceride levels (OR 1.3 [1.0-1.6], p < 0.05) were independent predictors of CAD in the patients with SMI.

CONCLUSION

Current guidelines criteria are able to predict SMI but prediction may be improved by considering male gender and the presence of retinopathy. CAD is more frequent in the patients with SMI who are current smokers, have severe retinopathy and higher triglyceride levels.

Energy level diagram and kinetics of luminescence of Ag nanoclusters dispersed in a glass host

A site-selective spectroscopy study of Ag nanoclusters dispersed in oxyfluoride glass hosts has been carried out. The nano- to millisecond, essentially non-exponential, luminescence kinetics of Ag nanoclusters has been detected in the spectral range from 450 to 1000 nm, when excited at discrete wavelengths in the range 250 to 450 nm. Based on these experimental observations, the energy level configuration coordinate diagram for the involved ground and excited singlet/triplet states of the Ag nanoclusters has been proposed and confirmed by the density functional theory (DFT). The sites for the Ag nanoclusters are argued to be multiple. The structure/geometry of the involved Ag nanoclusters has been suggested to involve spin-paired dimers Ag²⁺, or tetramers Ag₄²⁺, with a varying elongation/distortion along the tetramer diagonals.

Structural identification of caged vanadium doped silicon clusters

The geometry of cationic silicon clusters doped with vanadium, Si(n)V(+) (n=12-16), is investigated by using infrared multiple photon dissociation of the corresponding rare gas complexes in combination with ab initio calculations. It is shown that the clusters are endohedral cages, and evidence is provided that Si(16)V(+) is a fluxional system with a symmetric Frank-Kasper geometry.

What would be the outcome if the American Diabetes Association recommendations of 2010 had been followed in our practice in 1998-2006?

AIMS

In 2010, the American Diabetes Association has published recommendations on the population to be screened for dysglycaemia; the diagnostic criteria for intermediate hyperglycaemia and diabetes using oral glucose tolerance testing and HbA(1c); and the patients eligible for treatment with metformin. We aimed to evaluate the consequences of screening with oral glucose tolerance test or HbA(1c) in an at-risk population.

METHODS

Among 1177 overweight or obese consecutive adults without known diabetes who were referred to our department for weight management, we selected 1157 individuals (83% female; 80% European) fulfilling the American Diabetes Association 2010 criteria for dysglycaemia screening.

RESULTS

Mean age was 41.2 ± 13 years, BMI 37.0 ± 7.2 kg/m(2), fasting plasma glucose 4.9 ± 0.8 mmol/l and HbA(1c) (turbidimetric immunoassay) 5.7 ± 0.7% (39 mmol/mol). Based on oral glucose tolerance test and HbA(1c), respectively, 76 (6.6%) and 113 (9.8%) patients had diabetes, including 34 sharing both criteria; 307 (26.5%) and 478 (41.3%) had intermediate hyperglycaemia; and 130 (11.2%) and 255 (22.0%) would be treated with metformin. The sensitivity/specificity of HbA(1c) ≥ 6.5% (48 mmol/mol) for the diagnosis of diabetes according to the oral glucose tolerance test were 44.7/92.7%. Diabetes risk scores and UK Prospective Diabetes Study cardiovascular risk score were the highest in the 130 patients having both an abnormal oral glucose tolerance test and HbA(1c) ≥ 5.7%.

CONCLUSIONS

In a population at risk for diabetes, the HbA(1c) strategy could lead to diagnosing more cases of dysglycaemia and to treating more patients with metformin than the oral glucose tolerance test strategy. The consistency of either diagnostic criteria was low. The patients with the highest a priori risk of diabetes and cardiovascular disease were those fulfilling both oral glucose tolerance test and HbA(1c) criteria.

Retrofitting the suburbs to increase walking: evidence from a land-use-travel study

This paper reports results from a detailed travel diary survey of 2125 residents in the South Bay area of Los Angeles County - a mature, auto-oriented suburban region. Study areas were divided into four centres, typical of compact development or smart growth, and four linear, auto-oriented corridors. Results show substantial variation in the amount of walking across study areas. Trips are shorter and more likely to be via walking in centres. A key to the centres' increased walking travel is the concentration of local shopping and service destinations in a commercial core. Yet the amount of business concentration that is associated with highly pedestrian-oriented neighbourhoods is from three to four times as large as what can be supported by the local resident base, suggesting that pedestrian-oriented neighbourhoods necessarily import shopping trips, and hence driving trips, from larger surrounding catchment areas. The results suggest both land use and mobility strategies that can be appropriate for suburban regions.

N-terminal pro-B-type natriuretic peptide: an independent marker for coronary artery disease in asymptomatic diabetic patients

AIMS

To determine whether plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, a marker for cardiac failure and potentially for the severity of coronary artery disease (CAD), predicts silent myocardial ischaemia (SMI) and silent CAD in asymptomatic high-risk diabetic patients.

METHODS

Five hundred and seventeen asymptomatic diabetic patients with > or = 1 additional cardiovascular risk factor but without heart failure were prospectively screened between 1998 and 2008 for SMI, defined as an abnormal stress myocardial scintigraphy, and subsequently for significant (> 70%) angiographic CAD. The 323 patients with interpretable echocardiography and for whom NT-proBNP was measured were included in this analysis.

RESULTS

SMI was found in 108 (33.4%) patients, 39 of whom had CAD. NT-proBNP was higher in the patients with CAD than in the patients without CAD [45.0 (1-3199) vs. 20.0 (1-1640) pg/ml; P < 0.0001 median (range)], even after adjustment for confounding factors: age, gender, body mass index, glycated haemoglobin (HbA(1c)), retinopathy, nephropathy, hypertension, echocardiographic parameters (P < 0.05). NT-proBNP in the third tertile (> or = 38 pg/ml) predicted CAD with a sensitivity of 59% and a specificity of 67%. In a multiple logistic regression analysis including NT-proBNP > or = 38 pg/ml, age, body mass index, gender, HbA(1c), hypertension, retinopathy, nephropathy, peripheral occlusive arterial disease, left ventricular systolic dysfunction, dilatation and hypertrophy and Type 1 transmitral flow, NT-proBNP > or = 38 pg/ml was the only significant independent predictor of silent CAD [odds ratio (OR) 3.1 (95% confidence interval 1.3-7.6), P = 0.015].

CONCLUSIONS

NT-proBNP measurement helps to better define asymptomatic diabetic patients with an increased likelihood for CAD, independently of cardiac function and structure.

Bouc-Wen model parameter identification for a MR fluid damper using computationally efficient GA

A non-symmetrical Bouc-Wen model is proposed in this paper for magnetorheological (MR) fluid dampers. The model considers the effect of non-symmetrical hysteresis which has not been taken into account in the original Bouc-Wen model. The model parameters are identified with a Genetic Algorithm (GA) using its flexibility in identification of complex dynamics. The computational efficiency of the proposed GA is improved with the absorption of the selection stage into the crossover and mutation operations. Crossover and mutation are also made adaptive to the fitness values such that their probabilities need not be user-specified. Instead of using a sufficiently number of generations or a pre-determined fitness value, the algorithm termination criterion is formulated on the basis of a statistical hypothesis test, thus enhancing the performance of the parameter identification. Experimental test data of the damper displacement and force are used to verify the proposed approach with satisfactory parameter identification results.

Letter: OCCO*+, NNCO*+ and NNNN*+ radical cations

Chemical ionization of a mixture of nitrogen and carbon monoxide produces three stable isobaric species at m/z 56: OCCO, OCNN and NNNN radical cations. Separated at increased resolution, these ions are readily identified by collisional activation. Neutralization-reionization experiments performed on two different mass spectrometers have not allowed the detection of any recovery signals for the corresponding neutrals.

Quenching of the magnetic moment of a transition metal dopant in silver clusters

Single magnetic atoms embedded in a nonmagnetic host exhibit the Kondo effect in the bulk limit, while in very small molecules the magnetic atom is hardly affected by the matrix. In a combined theoretical (density functional theory) and experimental (photofragmentation and mass spectrometry) study we consider the intermediate case of nanometer sized transition-metal-doped silver clusters. In particular, we provide experimental evidence for enhanced stability of the cobalt-doped silver cluster Ag10Co+ and show theoretically that it has a symmetric endohedral geometry with a closed 18-electron singlet electronic shell structure. This implies that the magnetic moment on the cobalt atom is quenched.

Ab initio study of small graphitic cones with triangle, square, and pentagon apex

Accurate geometries of carbon nanocones of different sizes with a triangle, square or pentagon at the apex have been determined for the first time using a quantum chemical optimization method. The structure close to the apex is distorted from an ideal conical surface. The charging effect of the central defect is quite different from that predicted by tight-binding calculations. The symmetry behavior of the frontier orbitals and the size of the highest occupied molecular orbital-lowest unoccupied molecular orbital gap versus cone type and size is explained. The density of states quickly converges towards that of graphite when the size of the cone increases. In comparison to previous results in the literature it is found that the local densities of states of cones, that are locally different but belong to the same topo-combinatoric class, share common features.

Comparative study on pressure and temperature stability of 5-methyltetrahydrofolic acid in model systems and in food products

A comparative study on the pressure and temperature stability of 5-methyltetrahydrofolic acid (5-CH(3)-H(4)folate) was performed in model/buffer systems and food products (i.e., orange juice, kiwi puree, carrot juice, and asparagus). Effects of pH and ascorbic acid (0.5 mg/g) on 5-CH(3)-H(4)folate stability in buffer systems were studied on a kinetic basis at different temperatures (from 65 to 160 degrees C) and different pressure/temperature combinations (from 100 to 700 MPa/from 20 to 65 degrees C). These studies showed that (i) the degradation of 5-CH(3)-H(4)folate in all model systems could be described by first-order reaction kinetics, (ii) the thermostability of 5-CH(3)-H(4)folate was enhanced by increasing pH up to 7, (iii) 5-CH(3)-H(4)folate was relatively pressure stable at temperatures lower than 40 degrees C, and (iv) ascorbic acid enhanced both the thermo- and barostabilities of 5-CH(3)-H(4)folate. In food products, temperature and pressure stabilities of 5-CH(3)-H(4)folate were studied at different temperatures (70-120 degrees C) and different pressure/temperature combinations (from 50 to 200 MPa/25 degrees C and 500 MPa/60 degrees C). 5-CH(3)-H(4)folate in orange juice and kiwi puree was relatively temperature (up to 120 degrees C) and pressure (up to 500 MPa/60 degrees C) stable in contrast to carrot juice and asparagus. Addition of ascorbic acid (0.5 mg/g) in carrot juice resulted in a remarkable protective effect on pressure (500 MPa/60 degrees C/40 min) and temperature degradation (120 degrees C/40 min) of 5-CH(3)-H(4)folate.

Demographic trends in Vietnam

"Asia's four ¿little dragons' (South Korea, Hong Kong, Singapore and Taiwan) have in common not only an economic boom, but also the same rapid demographic transition. How does Vietnam, whose economy is poised for a take-off, stand in this respect? In an attempt to answer this question, [the authors] study the growing corpus of information which a number of ad hoc surveys have added to the 1979 and 1989 population censuses."

Pediatric imaging: sedation with an injection formulation modified for rectal administration

PURPOSE

To determine if rectal sedation with thiopental sodium produced for intravenous administration provides safe and effective sedation for children undergoing diagnostic imaging.

MATERIALS AND METHODS

Five hundred twenty-five consecutive children (mean age, 2.7 years +/- 2.2 [SD]) underwent magnetic resonance imaging (n = 425), computed tomography (n = 89), and nuclear medicine (n = 11) examinations after rectal administration of thiopental sodium injection solution. The solution was prepared from thiopental sodium powder mixed with sterile water to create a concentration of 100 mg/mL. The dose ranged from 25 to 40 mg per kilogram of body weight, with a total dose limit of 1.5 g. The percentages of successful sedations and adverse reactions were evaluated on the basis of data collected at the time of the sedation.

RESULTS

Sedation was successful in 504 (96%) children. Ten (2%) children experienced desaturation, but only three of the 10 experienced sedation failure. All cases of desaturation were treated successfully with head repositioning, administration of supplemental oxygen, or both. No children experienced vomiting, acute rectal irritation, paradoxical hyperactivity, or prolonged sedation.

CONCLUSION

Thiopental sodium sedation for pediatric imaging, with use of a rectal solution prepared from thiopental sodium preparation for intravenous injection, is safe and effective.