Prevotella intermedia Aggravates Subclinical Hypothyroidism.

Subclinical hypothyroidism (SCH) has been shown to be associated with microbiota. However, the association between SCH and oral microbiota has not yet been elucidated. The results of our previous clinical studies showed that Prevotella intermedia was abundant in the oral microbiota of SCH patients. This study aimed to investigate the relationship between SCH and oral microbiota, verify the pathogenicity of P. intermedia in SCH, and preliminarily explore the possible mechanism. The SCH mouse model with oral application of P. intermedia was established, and the variance in the mouse oral microbiota and changes in thyroid function and metabolism were detected in mice. Student's t test and analysis of variance were used for statistical analysis. Oral application of P. intermedia changed the composition of the oral microbiota of SCH mice, which enhanced the damage to the thyroid and decreased the expression of functional genes of the thyroid. Moreover, P. intermedia decreased oxygen consumption and aggravated glucose and lipid metabolism disorders in SCH mice. Glucose tolerance and insulin tolerance decreased, and the triglyceride content of the liver and inflammatory infiltration in adipose tissue increased in SCH mice after P. intermedia stimulation. Mechanistically, P. intermedia increased the proportion of CD4+ T cells in cervical lymph nodes and thyroids in SCH mice. Th1 cells were suggested to play an important role in the pathogenesis of SCH involving P. intermedia. In conclusion, P. intermedia aggravated SCH manifestations, including thyroid dysfunction and glucose and lipid metabolism disorders, by causing immune imbalance in mice. This study sheds new light on the pathogenesis of SCH from the perspective of oral microbiota.

Picric acid sensitive optode based on a fluorescence carrier covalently bound to membrane.

An acryloyl group was attached to fluorescein through the phenol hydroxyl group to make it photopolymerizable with 2-hydroxypropyl methacrylate and covalently immobilized on an optode glass surface modified with gamma-(methacryloxy)propyltrimethoxysilane. The optode system with a plastic-clad fused silica bifurcated fiber optic bundle shows satisfactory analytical performance characteristics for determining picric acid in terms of selectivity and reproducibility with a linear range from 8.0 x 10(-7) to 4.0 x 10(-3) mol L-1. The quenching mechanism was investigated. The optode membrane can be applied to the indirect determination of cinchonine drug and the results obtained were satisfactory.