Adaptive laboratory evolution of Rhodococcus rhodochrous DSM6263 for chlorophenol degradation under hypersaline condition.

BACKGROUND: Normally, a salt amount greater than 3.5% (w/v) is defined as hypersaline. Large amounts of hypersaline wastewater containing organic pollutants need to be treated before it can be discharged into the environment. The most critical aspect of the biological treatment of saline wastewater is the inhibitory/toxic effect exerted on bacterial metabolism by high salt concentrations. Although efforts have been dedicated to improving the performance through the use of salt-tolerant or halophilic bacteria, the diversities of the strains and the range of substrate spectrum remain limited, especially in chlorophenol wastewater treatment. RESULTS: In this study, a salt-tolerant chlorophenol-degrading strain was generated from Rhodococcus rhodochrous DSM6263, an original aniline degrader, by adaptive laboratory evolution. The evolved strain R. rhodochrous CP-8 could tolerant 8% NaCl with 4-chlorophenol degradation capacity. The synonymous mutation in phosphodiesterase of strain CP-8 may retard the hydrolysis of cyclic adenosine monophosphate (cAMP), which is a key factor reported in the osmoregulation. The experimentally verified up-regulation of intracellular cAMP level in the evolved strain CP-8 contributes to the improvement of growth phenotype under high osmotic condition. Additionally, a point mutant of the catechol 1,2-dioxygenase, CatAN211S, was revealed to show the 1.9-fold increment on activity, which the mechanism was well explained by molecular docking analysis. CONCLUSIONS: This study developed one chlorophenol-degrading strain with extraordinary capacity of salt tolerance, which showed great application potential in hypersaline chlorophenol wastewater treatment. The synonymous mutation in phosphodiesterase resulted in the change of intracellular cAMP concentration and then increase the osmotic tolerance in the evolved strain. The catechol 1,2-dioxygenase mutant with improved activity also facilitated chlorophenol removal since it is the key enzyme in the degradation pathway.

Effects of Surgical Timing of Facial Nerve Decompression for Patients With Severe Bell's Palsy.

Context: Bell's palsy is a form of idiopathic, facial nerve palsy. Initial treatment includes the use of oral corticosteroids and/or antiviral agents, but facial paralysis may persist. Some surgeons suggest that surgical decompression of the facial nerve can be a beneficial, but the optimal surgical approach, extent of nerve decompression, and timing of surgery remain unclear. Objective: This study intended to evaluate the efficacy of delayed, facial nerve decompression for severe Bell's palsy (BP) and to explore the relationship of opportunity timing for operations, with postoperative recovery for facial nerve function. Design: The research team performed a retrospective study. Setting: The study took place at Beijing Tiantan Hospital of Capital Medical University in Beijing, China. Participants: Participants were 45 patients who had been diagnosed with BP between 2015 and 2021 and who had undergone facial nerve decompression using the transmastoid approach, between 30 and 180 days after the onset of BP. According to the operation's timing, the research team divided the participants into three groups, consisting of participants who underwent surgery: (1) at 30-60-days after BP onset-19 participants, (2) at 61-90 days after BP onset-18 participants, and (3) at more than 90 days after BP onset-8 participants. Outcome Measures: The research team: (1) analyzed participants' demographic and preoperative and postoperative clinical characteristics, (2) compared the surgical outcomes with participants' House-Brackmann (HB) scales, and (3) analyzed the factors affecting the recovery of facial nerve function using logistic regression. Results: Decompression surgery was effective for 29 participants (64.4%), with similar rates for participants who underwent surgery after 30-60 days (73.7%) and 61-90 days (77.8%), but the surgery' success was significantly higher for those groups than for participants who underwent surgery after >90 days (12.5%), with P = .008 and P = .003, respectively. Multivariate logistic regression analysis showed that disease duration was the only factor significantly associated with the effectiveness of surgery (odds ratio = 120.337; 95% confidence interval 2.997-4832.267, P = .011). Conclusions: For patients with severe Bell's palsy with ineffective conservative treatment, surgery performed 30 to 90 days after the onset of paralysis can have therapeutic benefits, whereas surgery performed after 3 months is relatively ineffective.

[Blink restoration by the functional electrical stimulation in unilateral facial nerve palsy rabbits].

OBJECTIVE: Tocompare the effects of different waveforms and parameters of electrical stimulation to elicit a blink, and construct a functional electrical stimulation (FES) system to restore synchronous blink in unilateral facial nerve palsy (FNP). METHODS: Firstly, twenty-four rabbits were surgically induced unilateral FNP and were divided into three groups, who received square, sine and triangle pulse wareforms, respectirely. Both the healthy and the paralysis eyelids of the rabbits received pulse train stimulation to produce a blink in both eyes. For each rabbit, twenty-seven combinations of frequencies (25 Hz, 50 Hz and 100 Hz) and nine pulse widths (1-9 ms) were stimulated. The threshold amplitude and electric charge to elicit a blink was compared between different waveforms and different parameters. Secondly, a FES system was constructed to treat six surgically induced unilateral FNP rabbit chosen in the twenty-four rabbits, it consisted by an electromyogram (EMG) amplifier module which record the EMG of the healthy muscle, and a stimulator which received the EMG input and output a pulse train stimulation when triggered by the EMG. RESULTS: When the carrier frequency of the pulse train was 25 Hz, it was not able to induce a smooth blink. However, when the carrier frequencies were 50 Hz and 100 Hz, a smooth blink could be induced. The voltage required by 100 Hz was lower than 50 Hz, but it cost more electric charge. The amplitude that square waveforms required was far lower than sine and triangle, but the electric charge between the three waveforms was similar. Synchronous blink could be restored in the six unilateral FNP rabbits with the FES system. CONCLUSIONS: To elicit a blink, square pulse train delivered in 50 Hz is a preferable option. The motion of the healthy eyelids as a source of information for stimulation of the paralyzed sides can restore the synchronous blink in unilateral FNP rabbits.

[Survey of quality of life scale for patients with congenital ear malformation].

OBJECTIVE: To explore the congenital ear malformation (CEM)-specific quality of life (QOL) and examine the effects of total ear reconstruction surgery for QOL of CEM patients. METHODS: A self-composed QOL scale was used for 129 patients with congenital external and middle ear malformation. All patients were requested to fill in the QOL scale before and 1 month after ear reconstruction surgery. RESULTS: The level of QOL varied according to the degree of ear malformation. The total QOL score of patients with unilateral and bilateral CEM was 28.5 ± 18.4 and 51.6 ± 23.6, respectively. The total QOL score of patients pre- and post-operation was 21.0 ± 14.0 and 14.2 ± 9.7 respectively. Physiological functions, psychological status and social interactions of the patients were of statistical significance after ear reconstruction surgery compared to that of at pre-operation. CONCLUSION: Congenital ear malformation-specific QOL scale can show sensitively the changes of QOL of CEM patients. And ear reconstruction surgery is beneficial for the patients.