Objective To analyses the magnetic resonance imaging(MRI)findings of different clinical patterns of neurosyphilis(NS).Methods Clinical records and MRI of 26 patients with NS were retrospectively studied.Results Abnormal MRI was found in 17 patients of 26 patients with NS.In 7 patients were with meningo-vascular syphilis,the MRI commonly showed multiple cerebral ischemia focus and cerebral infarction focus,very few similar to those of encephalitis;Six patients had general paresis,who presented cerebral MRI abnormalities of frontal and temporal atrophy,and few simultaneously with cerebral ischemia focus,granular apendymitis and hippocampus sclerosis;Three patients had syphilitic myelitis,their MRI showed mild tumefaction with multiple ischemic focus all the way through lower cervical spinal cord to lower thoracic spinal cord:One patient was with tabes dorsalis,whose cerebral MRI showed ischemic locus.Another 9 patients had normal MRI,of whom 4 patients with meningitis NS and 5 with tabes dorsalis.Conclusion The MRI of neurosyphilis has diverse presentations,and clinicians should pay much attention to it.

Tetrapyrrole compounds are a class of compounds with important functions. They exist in living organisms and have been widely used in agriculture, food, medicine, and other fields. The cumbersome process and high cost of chemical synthesis, as well as the shortcomings of unstable quality of animal and plant extraction methods, greatly hampered the industrial production and applications of tetrapyrrole compounds. In recent years, the rapid development of synthetic biology has provided new tools for microorganisms to efficiently synthesize tetrapyrrole compounds from renewable biomass resources. This article summarizes various strategies for the biosynthesis of tetrapyrrole compounds, discusses methods to improve its biosynthesis efficiency and future prospects, with the aim to facilitate the research on biosynthesis of tetrapyrrole compounds.
Biomass ; Plants/genetics* ; Synthetic Biology ; Tetrapyrroles