Aβ40 oligomers identified as a potential biomarker for the diagnosis of Alzheimer's disease

Alzheimer's Disease (AD) is the most prevalent form of dementia worldwide, yet the development of therapeutics has been hampered by the absence of suitable biomarkers to diagnose the disease in its early stages prior to the formation of amyloid plaques and the occurrence of irreversible neuronal damage. Since oligomeric Aβ species have been implicated in the pathophysiology of AD, we reasoned that they may correlate with the onset of disease. As such, we have developed a novel misfolded protein assay for the detection of soluble oligomers composed of Aβ x-40 and x-42 peptide (hereafter Aβ40 and Aβ42) from cerebrospinal fluid (CSF). Preliminary validation of this assay with 36 clinical samples demonstrated the presence of aggregated Aβ40 in the CSF of AD patients. Together with measurements of total Aβ42, diagnostic sensitivity and specificity greater than 95% and 90%, respectively, were achieved. Although larger sample populations will be needed to confirm this diagnostic sensitivity, our studies demonstrate a sensitive method of detecting circulating Aβ40 oligomers from AD CSF and suggest that these oligomers could be a powerful new biomarker for the early detection of AD.     

Serum tumour M2-pyruvate kinase as a biomarker for diagnosis and prognosis of early-stage non–small cell lung cancer

Tumour M2-pyruvate kinase (TUM2-PK) is up-regulated in many human cancers. This study was to evaluate the clinical value of serum TUM2-PK in early-stage non–small cell lung cancer (NSCLC) patients. A total of 162 consecutive early-stage NSCLC patients were enrolled and followed up after tumour resection. Serum TUM2-PK level was detected by enzyme-linked immunosorbent assay (ELISA) in NSCLC patients, 50 benign pulmonary disease patients and 102 healthy controls. The TUM2-PK level in NSCLC patients was higher than that of healthy controls (P < .001) and benign pulmonary disease patients (P < .001). A threshold of 30 U/mL could be used to diagnose early-stage NSCLC with 71.6% sensitivity and 98.0% specificity. The 5-year overall survival rate in patients with high TUM2-PK level was lower than that of patients with low TUM2-PK level (P = .009). Multivariable Cox regression showed that high TUM2-PK level was an independent risk factor for overall survival (HR = 2.595, 95% CI: 1.231-5.474, P = .012). High serum TUM2-PK level could be a potential biomarker for diagnosis and prognosis of early-stage NSCLC patients.     

7β,12β-dihydroxy-5β-cholan-24-oic acid as an internal standard for quantitative determination of bile acids by gas chromatography

In order to find an artificial internal standard compound for quantitative determination of bile acids by gas chromatography, 7α,12α-,7α, 12β-, 7β,12α- and 7β,12β-dihydroxy-5β-cholan-24-oic acids were chemically synthesized with cholic acid (1) as the first starting material. The gas chromatographie retention time of 7β,12β-dihydroxy-5β-cholan-24-oic acid (ββ-isomer) was more different from that of natural bile acids than the other isomers. Moreover, ββ-isomer was extracted in the same fraction as the bile acids from urine, and no urinary substance had the same retention time as ββ-isomer. No artifact was produced from ββ-isomer during the analysis procedure. It was concluded that the ββ-isomer is an internal standard compound with certain advantages for the quantitative determination of bile acids in urine by gas chromatography, irrespective of the recovery rate during the analysis procedure.     

Genome mining and motif truncation of glycoside hydrolase family 5 endo-β-1,4-mannanase encoded by Aspergillus oryzae RIB40 for potential konjac flour hydrolysis or feed additive

Two novel glycosyl hydrolase family 5 (GH5) β-mannanases (AoMan5A and AoMan5B) were identified from Aspergillus oryzae RIB40 by genome mining. The AoMan5A contains a predicted family 1 carbohydrate binding module (CBM-1), located at its N-terminal. The AoMan5A, AoMan5 B and truncated mutant AoMan5AΔCL (truncating the N-terminal CBM and linker of AoMan5A) were expressed retaining the N-terminus of the native protein in Pichia pastoris GS115 by pPIC9 K^M. The specific enzyme activity of the purified reAoMan5A, reAoMan5 B and reAoMan5AΔCL towards locust bean gum at pH 3.6 and 40 °C for 10 min, was 8.3, 104.2 and 15.8 U/mg, respectively. The temperature properties of the reAoMan5AΔCL were improved by truncating CBM. They can degrade the pretreated konjac flour and produce prebiotics. In addition, they had excellent stability under simulative gastric fluid and simulative prilling process. All these properties make these recombinant β-mannanases potential additives for use in the food and feed industries.