ABSTRACT
INTRODUCTION AND IMPORTANCE: To report the sequential treatment of a Type II odontoid fracture combined with a severe lower cervical (C6-7) fracture-dislocation featuring bilateral facet joint interlocking. CASE PRESENTATION: A 58-year-old male who had suffered an injury in a car accident, He presented neck pain and extremity paralysis. His neurological function was classified as per the American Spinal Injury Association (ASIA) impairment scale as Grade A, indicating complete deficits below the C6 spinal cord level. A cervical CT scan and magnetic resonance image showed a type II odontoid fracture, C6 slipped anteriorly, C6-7 bilateral facet joint fracture and interlocking, slightly compression change of C7 upper endplate. CLINICAL DISCUSSION: Emergency closed reduction using cranial tong traction was success 6 h after the injury. A subsequent CT scan proved the successful reduction of bilateral facet joint dislocations and the odontoid fracture. After careful overall assessment, anterior cervical decompression and fusion (ACDF) was performed at C5-6 and C6-7 segments three days laterï¼while odontoid fracture was treated conservatively. At the 4 months follow-up, a CT scan demonstrated solid bone fusion at C5-6, C6-7 segments, along with successful healing at the odontoid fracture site. However, spinal cord was necrosis at C5-7 segments, and the patient's neurological function had no improvement. CONCLUSION: The initial closed reduction could restore the alignment and preliminary stability of cervical spine at sub-axial cervical fracture-dislocation segment as well as displaced odontoid fracture. This timely and effective closed reduction significantly diminished sequential surgical trauma and mitigated associated risks.
ABSTRACT
The sulfide oxygenation activities of both heptamolybdate ([Mo7O24]6-, [1]6-) and its peroxo adduct [Mo7O22(O2)2]6- ([2]6-) were examined in this contribution. [Mo7O22(O2)2]6- was prepared in a yield of 65% from (NH4)6[Mo7O24] (1a) upon treatment of 10 equiv. of H2O2 and structurally identified through single crystal X-ray diffraction study. (nBu4N)6[Mo7O22(O2)2] (2b) is an efficient catalyst for the sequential oxygenation of methyl phenyl sulfide (MPS) by H2O2 to the corresponding sulfoxide and subsequently sulfone with a 100% utility of H2O2. Surprisingly, (nBu4N)6[Mo7O24] (1b) is a significantly faster catalyst than 2b for MPS oxygenation under identical conditions. The pseudo-first order kcat constants from initial rate kinetics are 54 M-1 s-1 and 19 M-1 s-1 for 1b and 2b, respectively. Electrospray ionization mass spectrometry (ESI-MS) investigation of 1b under the catalytic reaction conditions revealed that [Mo2O11]2- is likely the main active species in sulfide oxygenation by H2O2.
ABSTRACT
Glycyl radicals are important bioorganic radical species involved in enzymatic catalysis. Herein, we demonstrate that the stability of glycyl-type radicals (X-(.) CH-Y) can be tuned on a molecular level by varying the X and Y substituents and experimentally probed by mass spectrometry. This approach is based on the gas-phase dissociation of cysteine sulfinyl radical (X-Cys SO .-Y) ions through homolysis of a Cα Cß bond. This fragmentation produces a glycyl-type radical upon losing CH2 SO, and the degree of this loss is closely tied to the stability of the as-formed radical. Theoretical calculations indicate that the energy of the Cα Cß bond homolysis is predominantly affected by the stability of the glycyl radical product through the captodative effect, rather than that of the parent sulfinyl radical. This finding suggests a novel experimental method to probe the stability of bioorganic radicals, which can potentially broaden our understanding of these important reactive intermediates.
