Axial length shortening in myopic children with Stickler syndrome after repeated low-level red-light therapy.

AIM: To report the myopia-controlling effect of repeated low-level red-light (RLRL) therapy in patients with Stickler syndrome (STL), an inherited collagenic disease typically presenting with early onset myopia. METHODS: Three STL children, aged 3, 7, and 11y, received RLRL therapy throughout the follow-up period of 17, 3, and 6mo, respectively after exclusion of fundus anomalies. Data on best-corrected visual acuity (BCVA), intraocular pressure, cycloplegic subjective refraction, ocular biometrics, scanning laser ophthalmoscope, optical coherence tomography, genetic testing, systemic disease history, and family history were recorded. RESULTS: At the initiation of the RLRL therapy, the spherical equivalent (SE) of 6 eyes from 3 patients ranged from -3.75 to -20.38 D, axial length (AL) were from 23.88 to 30.68 mm, and BCVA were from 0.4 to 1.0 (decimal notation). Myopia progression of all six eyes slowed down after RLRL therapy. AL in five out of the six eyes shortened -0.07 to -0.63 mm. No side effects were observed. CONCLUSION: Three cases of STL whose progression of myopic shift and AL elongation are successfully reduced and even reversed after RLRL therapy.

Enzymatic preparation of manno-oligosaccharides from locust bean gum and palm kernel cake, and investigations into its prebiotic activity

BACKGROUND: Manno-oligosaccharides (MOS) is known as a kind of prebiotics. Mannanase plays a key role for the degradation of mannan to produce MOS. In this study, the mannanases of glycoside hydrolase (GH) families 5 Man5HJ14 and GH26 ManAJB13 were employed to prepare MOS from locust bean gum (LBG) and palm kernel cake (PKC). The prebiotic activity and utilization of MOS were assessed in vitro using the probiotic Lactobacillus plantarum strain. RESULTS: Galactomannan from LBG was converted to MOS ranging in size from mannose up to mannoheptose by Man5HJ14 and ManAJB13. Mannoheptose was got from the hydrolysates produced by Man5HJ14, which mannohexaose was obtained from LBG hydrolyzed by ManAJB13. However, the same components of MOS ranging in size from mannose up to mannotetrose were observed between PKC hydrolyzed by the mannanases mentioned above. MOS stability was not affected by high-temperature and high-pressure condition at their natural pH. Based on in vitro growth study, all MOS from LBG and PKC was effective in promoting the growth of L. plantarum CICC 24202, with the strain preferring to use mannose to mannotriose, rather than above mannotetrose. CONCLUSIONS: The effect of mannanases and mannan difference on MOS composition was studied. All of MOS hydrolysates showed the stability in adversity condition and prebiotic activity of L. plantarum, which would have potential application in the biotechnological applications.

Identification and Characterization of a New 7-Aminocephalosporanic Acid Deacetylase from Thermophilic Bacterium Alicyclobacillus tengchongensis.

UNLABELLED: Deacetylation of 7-aminocephalosporanic acid (7-ACA) at position C-3 provides valuable starting material for producing semisynthetic ß-lactam antibiotics. However, few enzymes have been characterized in this process before now. Comparative analysis of the genome of the thermophilic bacterium Alicyclobacillus tengchongensis revealed a hypothetical protein (EstD1) with typical esterase features. The EstD1 protein was functionally cloned, expressed, and purified from Escherichia coli BL21(DE3). It indeed displayed esterase activity, with optimal activity at around 65°C and pH 8.5, with a preference for esters with short-chain acyl esters (C2 to C4). Sequence alignment revealed that EstD1 is an SGNH hydrolase with the putative catalytic triad Ser15, Asp191, and His194, which belongs to carbohydrate esterase family 12. EstD1 can hydrolyze acetate at the C-3 position of 7-aminocephalosporanic acid (7-ACA) to form deacetyl-7-ACA, which is an important starting material for producing semisynthetic ß-lactam antibiotics. EstD1 retained more than 50% of its initial activity when incubated at pH values ranging from 4 to 11 at 65°C for 1 h. To the best of our knowledge, this enzyme is a new SGNH hydrolase identified from thermophiles that is able to hydrolyze 7-ACA. IMPORTANCE: Deacetyl cephalosporins are highly valuable building blocks for the industrial production of various kinds of semisynthetic ß-lactam antibiotics. These compounds are derived mainly from 7-ACA, which is obtained by chemical or enzymatic processes from cephalosporin C. Enzymatic transformation of 7-ACA is the main method because of the adverse effects chemical deacylation brought to the environment. SGNH hydrolases are widely distributed in plants. However, the tools for identifying and characterizing SGNH hydrolases from bacteria, especially from thermophiles, are rather limited. Here, our work demonstrates that EstD1 belongs to the SGNH family and can hydrolyze acetate at the C-3 position of 7-ACA. Moreover, this study can enrich our understanding of the functions of these enzymes from this family.