Association of inflammatory cytokines expression in cerebrospinal fluid with the severity and prognosis of spontaneous intracerebral hemorrhage.

OBJECTIVE: To investigate the potential diagnostic and prognostic implications of inflammatory cytokine levels in the cerebrospinal fluid (CSF) of patients with spontaneous intracerebral hemorrhage (SICH) upon their initial hospital admission. METHODS: Our cohort included 100 patients diagnosed with acute SICH, presenting to the Department of Neurosurgery. Additionally, we recruited 50 individuals without central nervous system (CNS) pathology, treated concurrently at our facility, as controls. CSF samples, collected upon hospital entry, were quantitatively assessed for 10 inflammatory cytokines using the Mesoscale Discovery Platform (MSD, Rockville, MD, USA) electrochemiluminescence technology, followed by validation through enzyme-linked immunosorbent assay (ELISA). RESULTS: We observed a marked elevation of IL-6, IL-8, IL-10, and TNF-α in the CSF of the SICH subgroup compared to controls. Higher Glasgow Coma Scale (GCS) scores in SICH patients corresponded with lower CSF concentrations of IL-6, IL-8, IL-10, and TNF-α, indicating an inverse relationship. Notably, CSF inflammatory cytokine levels were consistently higher in SICH patients with hydrocephalus than in those without. Increases in IL-6, IL-8, IL-10, and TNF-α in the CSF were notably more pronounced in the poor prognosis group (Glasgow Outcome Scale, GOS 1-3) compared to those with a favorable prognosis (GOS 4-5). The AUC values for these cytokines in predicting SICH prognosis were 0.750, 0.728, 0.717, and 0.743, respectively. CONCLUSIONS: Initial CSF levels of IL-6, IL-8, IL-10, and TNF-α upon admission provide significant insights into the severity of neural damage and are robust indicators for prognosis in SICH patients.

Biochemical characterization of a GH19 chitinase from Streptomyces alfalfae and its applications in crystalline chitin conversion and biocontrol.

Chitinases play crucial roles in enzymatic conversion of chitin and biocontrol of phytopathogenic fungi. Herein, a chitinase of glycoside hydrolase (GH) family 19, SaChiB, was cloned from Streptomyces alfalfae ACCC 40021 and expressed in Escherichia coli BL21(DE3). The purified SaChiB displayed maximal activities at 45 °C and pH 8.0, and showed good stability up to 55 °C and in the range of pH 4.0-11.0, respectively. It exhibited substrate specificity towards chitin and chitooligosaccharides (degree of polymerization 3-6) with the endo-cleavage manner. In combination with the N-acetyl hexosaminidase SaHEX, it yielded a conversion rate of 95.2% from chitin powder to N-acetyl-D-glucosamine in 8 h and a product purity of >98.5%. Furthermore, the enzyme strongly inhibited the growth of tested pathogenic fungi. These results indicated that SaChiB has the great potential for applications in the conversion of raw chitinous waste in industries as well as the biocontrol of fungal diseases in agriculture.

[Cloning, expression and characterization of a new endo-ß-N-acetylglucosaminidase from Streptomyces alfalfae].

Endo-ß-N-acetylglucosaminidase is used widely in the glycobiology studies and industries. In this study, a new endo-ß-N-acetylglucosaminidase, designated as Endo SA, was cloned from Streptomyces alfalfae ACCC 40021 and expressed in Escherichia coli BL21 (DE3). The purified recombinant Endo SA exhibited the maximum activity at 35 ºC and pH 6.0, good thermo/pH stability and high specific activity (1.0×106 U/mg). It displayed deglycosylation activity towards different protein substrates. These good properties make EndoSA a potential tool enzyme and industrial biocatalyst.

Biochemical characterization of a ß-N-acetylhexosaminidase from Streptomyces alfalfae and its application in the production of N-acetyl-d-glucosamine.

N-Acetyl-d-glucosamine (GlcNAc) is a valuable monosaccharide widely used in the medical, agricultural, biofuel, and food industries. Its efficient and environment-friendly production depends on the binary system of ß-N-acetylhexosaminidase (HEX) and chitinase. In the present study, a HEX of glycoside hydrolasefamily 20 was identified in Streptomyces alfalfae ACCC40021, and was overexpressed in Escherichia coli. The purified recombinant SaHEX showed maximal activities at 60°C and pH 5.5, and retained stable up to 45°C. The enzyme not only exhibited broad substrate specificity including p-nitrophenyl ß-N-acetylglucosaminide, p-nitrophenyl ß-N-acetylgalactosaminide, chitooligosaccharides and colloidal chitin, but also had higher specific activities (up to 1149.7 ± 72.6 U/mg) towards natural and synthetic substrates. When combined with a commercial chitinase, it achieved a conversion rate of 93.7% from 1% of colloidal chitin to GlcNAc in 6 h, with the product purity of >98%. These excellent properties make SaHEX a potential enzyme candidate for the chitin conversion for various industrial purposes.