Cellulose-starch Hybrid Films Plasticized by Aqueous ZnCl2 Solution.

Starch and cellulose are two typical natural polymers from plants that have similar chemical structures. The blending of these two biopolymers for materials development is an interesting topic, although how their molecular interactions could influence the conformation and properties of the resultant materials has not been studied extensively. Herein, the rheological properties of cellulose/starch/ZnCl2 solutions were studied, and the structures and properties of cellulose-starch hybrid films were characterized. The rheological study shows that compared with starch (containing mostly amylose), cellulose contributed more to the solution's viscosity and has a stronger shear-thinning behavior. A comparison between the experimental and calculated zero-shear-rate viscosities indicates that compact complexes (interfacial interactions) formed between cellulose and starch with ≤50 wt % cellulose content, whereas a loose structure (phase separation) existed with ≥70 wt % cellulose content. For starch-rich hybrid films prepared by compression molding, less than 7 wt % of cellulose was found to improve the mechanical properties despite the reduced crystallinity of the starch; for cellulose-rich hybrid films, a higher content of starch reduced the material properties, although the chemical interactions were not apparently influenced. It is concluded that the mechanical properties of biopolymer films were mainly affected by the structural conformation, as indicated by the rheological results.

Comprehensive Diagnostic Criteria for MELAS Syndrome; a Case Study Involving an Elderly Patient With MT-TWm.5541C>T Mutation.

INTRODUCTION: The mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a matrilineal hereditary multisystem disease caused by mutations in the mitochondrial DNA. Although the initial diagnostic criteria correlate with a range of clinical phenotypes, including clinical onset after the age of 40, there is still lack of a unified single diagnostic standard for MELAS. CASE REPORT: A 71-year-old female patient with recurrent stroke was reported. Magnetic resonance imaging showed a cerebral gyrus-like diffusion weighted imaging high signal lesion in the parietal-occipital lobe and the area of this lesion expanded with disease progression. The MRS result showed significantly inverted Lac/Lip peaks. The nucleic acid sequencing result displayed a MT-TWm.5541C>T mutation, and a 12.86% mutation rate in the blood sample. The patient had a 6-year history of type 2 diabetes. CONCLUSION: Patients with the MELAS syndrome may present with a variety of clinical manifestations. Our data demonstrated that, for patients with atypical cerebral infarction and suspected MELAS syndrome, gene sequencing and muscle biopsy should be performed in time. This case provides a reference for the diagnostic criteria of MELAS syndrome.

Ataxia with oculomotor apraxia type 2 caused by a novel homozygous mutation in SETX gene, and literature review.

Objectives: Autosomal recessive inherited ataxia with oculomotor apraxia type 2 (AOA2), caused by SETX gene mutations, is characterized by early-onset, progressive cerebellar ataxia, peripheral neuropathy, oculomotor apraxia and elevated serum α-fetoprotein (AFP). This study aimed to expand and summarize the clinical and genetic characteristics of SETX variants related to AOA2. Methods: The biochemical parameters, electromyogram and radiological findings of the patient were evaluated. Whole-exome sequencing (WES) was performed on the patient using next-generation sequencing (NGS), the variants were confirmed by Sanger sequencing and the pathogenicity of the variants was classified according to the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines. We reviewed 57 studies of AOA2 patients with SETX mutations and collected clinical and genetic information. Results: The patient was a 40-year-old Chinese woman who primarily presented with numbness and weakness of the lower limbs in her teenage years. She had elevated AFP, increased serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and decreased anti-Müllerian hormone (AMH) levels. We identified a novel homozygous missense mutation of the SETX gene, c.7118 C>T (p. Thr2373Ile), in the patient via Whole-exome and Sanger sequencing. The variant was located in the DNA/RNA helicase domain and is highly conserved. The protein prediction analysis verified the SETX variant as a damaging alteration and ACMG/AMP guidelines classified it as likely pathogenic. Through a literature review, we identified 229 AOA2 cases with SETX variants, and among the variants, 156 SETX variants were exonic. We found that 107 (46.7%) patients were European, 50 (21.8%) were African and 48 (21.0%) were Asian. Among the Asian patients, five from two families were Mainland Chinese. The main clinical features were cerebellar ataxia (100%), peripheral neuropathy (94.6%), cerebellar atrophy (95.3%) and elevated AFP concentration (92.0%). Most reported SETX mutations in AOA2 patients were missense, frameshift and nonsense mutations. Conclusion: We discovered a novel homozygous variant of the SETX gene as a cause of AOA2 in the current patient and expanded the genotypic spectrum of AOA2. Moreover, the clinical features of AOA2 and genetic findings in SETX were assessed in reported cohorts and are summarized in the present study.

Identification and functional analysis of differentially expressed genes associated with cerebral ischemia/reperfusion injury through bioinformatics methods.

Cerebral ischemia/reperfusion (I/R) injury results in detrimental complications. However, little is known about the underlying molecular mechanisms involved in the reperfusion stage. The aim of the present study was to identify a gene expression profile associated with cerebral ischemia/reperfusion injury. The GSE23160 dataset, which comprised data from sham control samples and post­I/R injury brain tissues that were obtained using a middle cerebral artery occlusion (MCAO) model at 2, 8 and 24 h post­reperfusion, was downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) in the MCAO samples compared with controls were screened using the GEO2R web tool. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for DEGs was performed using the online tool DAVID. Furthermore, a protein­protein interaction (PPI) network was constructed using the STRING database and Cytoscape software. In total, 32 DEGs at 2 h post­reperfusion, 39 DEGs at 8 h post­reperfusion and 91 DEGs at 24 h post­reperfusion were identified, while 15 DEGs were common among all three groups. GO analysis revealed that the DEGs at all three time­points were enriched in 'chemotaxis' and 'inflammatory response' terms, while KEGG pathway analysis demonstrated that DEGs were significantly enriched in the 'chemokine signaling pathway'. Furthermore, following PPI network construction, Cxcl1 was identified as the only hub gene that was common among all three time­points. In conclusion, the present study has demonstrated a global view of the potential molecular differences following cerebral I/R injury and may contribute to an improved understanding of the reperfusion stage, which may ultimately aid in the development of future clinical strategies.