Quantitative US fat fraction for noninvasive assessment of hepatic steatosis in suspected metabolic-associated fatty liver disease.

OBJECTIVES: To evaluate the agreement between quantitative ultrasound system fat fraction (USFF) and proton magnetic resonance spectroscopy (1H-MRS) and the diagnostic value of USFF in assessing metabolic-associated fatty liver disease (MAFLD). METHODS: The participants with or suspected of MAFLD were prospectively recruited and underwent 1H-MRS, USFF, and controlled attenuation parameter (CAP) measurements. The correlation between USFF and 1H-MRS was assessed using Pearson correlation coefficients. The USFF diagnostic performance for different grades of steatosis was evaluated using receiver operating characteristic curve analysis (ROC) and was compared with CAP, visual hepatic steatosis grade (VHSG). RESULTS: A total of 113 participants (mean age 44.79 years ± 13.56 (SD); 71 males) were enrolled, of whom 98 (86.73%) had hepatic steatosis (1H-MRS ≥ 5.56%). USFF showed a good correlation (Pearson r = 0.76) with 1H-MRS and showed a linear relationship, which was superior to the correlation between CAP and 1H-MRS (Pearson r = 0.61). The USFF provided high diagnostic performance for different grades of hepatic steatosis, with ROC from 0.84 to 0.98, and the diagnostic performance was better than that of the CAP and the VHSG. The cut-off values of the USFF were different for various grades of steatosis, and the cut-off values for S1, S2, and S3 were 12.01%, 19.98%, and 22.22%, respectively. CONCLUSIONS: There was a good correlation between USFF and 1H-MRS. Meanwhile, USFF had good diagnostic performance for hepatic steatosis and was superior to CAP and VHSG. USFF represents a superior method for noninvasive quantitative assessment of MAFLD. CRITICAL RELEVANCE STATEMENT: Quantitative ultrasound system fat fraction (USFF) accurately assesses liver fat content and has a good correlation with magnetic resonance spectroscopy (1H-MRS) for the assessment of metabolic-associated fatty liver disease (MAFLD), as well as for providing an accurate quantitative assessment of hepatic steatosis. KEY POINTS: Current diagnostic and monitoring modalities for metabolic-associated fatty liver disease have limitations. USFF correlated well with 1H-MRS and was superior to the CAP. USFF has good diagnostic performance for steatosis, superior to CAP and VHSG.

Mechanism of the All-α to All-ß Conformational Transition of RfaH-CTD: Molecular Dynamics Simulation and Markov State Model.

The C-terminal domain of the bacterial transcription antiterminator RfaH undergoes a dramatic all-α-helix to all-ß-barrel transition when released from its N-terminal domain. These two distinct folding patterns correspond to different functions: the all-α state acts as an essential regulator of transcription to ensure RNA polymerase binding, whereas the all-ß state operates as an activator of translation by interacting with the ribosomal protein S10 and recruits ribosomal mRNA. Accordingly, this drastic conformational change enables RfaH to physically couple the transcription and translation processes in gene expression. To understand the mechanism behind this extraordinary functionally relevant structural transition, we constructed Markov state models using an adaptive seeding method. The constructed models highlight several parallel folding pathways with heterogeneous molecular mechanisms, which reveal the folding kinetics and atomic details of the conformational transition.

Cerebral perfusion SPECT imaging for assessment of the effect of hyperbaric oxygen therapy on patients with postbrain injury neural status.

OBJECTIVE: To evaluate the effects of hyperbaric oxygen (HBO) therapy on patients with postbrain injury neural status. METHODS: Two to 4 courses of HBO therapy and/or medications were used to treat 320 patients who were randomly divided into two groups. Assessment was made with (99m)Tc-ethyl cysteinate dimer ( (99m)Tc-ECD) single photon emission computed tomography (SPECT) before and after treatment. RESULTS: There was a significant difference between the HBO therapy group and the non-HBO therapy group. HBO therapy was superior to medication treatment alone in the recovery of clinical symptoms, control of epilepsy, and resolution of hydrocephalus (P<0.01). CONCLUSIONS: HBO therapy has specific curative effects on patients with postbrain injury neural status, and (99m)Tc-ECD SPECT could play an important role in diagnosing postbrain injury neural status and monitoring the therapeutic effects of HBO.