Preparation of shikonin liposome and evaluation of its in vitro antibacterial and in vivo infected wound healing activity.

BACKGROUND: The emergence of antibiotic resistance over the past decade has made the treatment of Staphylococcus aureus infection difficult. Burn wounds infected with methicillin-resistant S. aureus (MRSA) can cause mortality in animals. Shikonin (SH) has been reported to possess antimicrobial and anti-inflammatory properties, and is also responsible for the process of wound healing. However, the pharmacological mechanism of its wound healing process remains poorly comprehended, hence the probable mechanism deserves further investigation. PURPOSE: The current study was designed to develop a novel SH-liposome with improved anti-MRSA effect and to detect its beneficial wound healing effects. STUDY DESIGN: In vitro antibacterial tests and in vivo infected wound healing test were conducted. METHODS: SH-liposome was produced by the film formation method, and the characteristics were measured using a laser particle size analyzer, transmission electron microscopy, and the dialysis method. Additionally, in vitro antibacterial tests were conducted to investigate the antibacterial effects and the relative mechanism of SH-liposome. Furthermore, the therapeutic effects and bioactivity of SH-liposome in MRSA infected burn wounds were investigated in rats. Sixty-four male Sprague Dawley rats (250 ± 10 g) were randomly divided into four groups, including Group I (control group); Group II (model group); Group III (SH-liposome group) and Group IV (Arnebia oil® group), and the drug treatments were applied topically twice daily for 21 days. Further, full thickness skin biopsies at different periods were collected aseptically to evaluate tissue cytokines, recognize flora, observe histopathological changes, and determine the mechanism underlying the wound healing effects of SH-liposome. The data were analyzed via one-way analysis of variance (ANOVA) and Duncan's multiple range test. RESULTS: The results showed that SH-liposome was successful with a drug load of 4.6 ± 0.17%. Moreover, SH-liposome showed a sustained-release behavior and improved antibacterial ability in a dose-dependent manner. For the possible antibacterial mechanism, we observed that SH-liposome achieved antibacterial activity by damaging the integrity of bacterial cell wall and membrane to further disturb the physiological activities of S. aureus. In addition, SH-liposome facilitated wound healing by inhibiting bacterial activities to control infection, regulating the I-κBα/NFκB-p65 pathway to alleviate inflammation, and directly promoting repair in burn wounds. CONCLUSION: In conclusion, SH-liposome showed an antibacterial effect against S. aureus, promoted effective healing of infected burn wounds; hence, it could be used as an alternative therapy for drug-resistant infections.

Optimization Extraction of Shikonin Using Ultrasound-Assisted Response Surface Methodology and Antibacterial Studies.

The objectives of this study were to develop and optimize ultrasound-assisted extraction (UAE) for shikonin from Arnebia euchroma using response surface methodology (RSM) and to evaluate the antimicrobial activity of shikonin. The maximum yield of shikonin was 1.26% under the optimal extraction conditions (ultrasound power, 93 W; time, 87 min; temperature, 39°C; and liquid-solid ratio, 11 : 1). Shikonin showed inhibitory activity against standard strains and clinical isolates to varying extents (MICs ranging from 128 to 1024 µg/mL, MBCs ranging from 256 to 2048 µg/mL), and it was more effective for Gram-positive bacteria as indicated by lower MIC and MBC values. Time-kill curves revealed that antibacterial activity of shikonin exhibited a dose-response relationship. In summary, via this study, we identified ultrasound-assisted RSM as the optimal extraction method for shikonin, which is a potential material for the treatment of bacterial infections.

Relationship Between Pituitary Adenoma Consistency and Extent of Resection Based on Tumor/Cerebellar Peduncle T2-Weighted Imaging Intensity (TCTI) Ratio of the Point on Preoperative Magnetic Resonance Imaging (MRI) Corresponding to the Residual Point on Postoperative MRI.

BACKGROUND Controversies exist in imaging modalities for predicting adenoma consistency. In this study, we proposed a method of predicting consistency by magnetic resonance T2-sequence imaging based on adenoma to cerebellar peduncle signal (TCTI) ratio. MATERIAL AND METHODS Between January 2013 and May 2017, 191 consecutive patients with pituitary adenoma diagnosed at our institution were retrospectively studied. The consistency grade for each lesion was assigned. And the TCTI ratio based on preoperative and postoperative T2-weighted imaging was calculated. RESULTS The median TCTI ratio was 1.55, 1.28, and 1.25 for soft, fibrous, and hard adenomas, respectively. The differences were significant for all groups (p<0.001). A cutoff value of 1.38 for soft adenomas was found to be 80.2% sensitive and 88.7% specific. The median ratio of the outermost layer of residual tumor was 1.25 (SD±0.408, 95% CI 1.27-1.42). It was less than that ratio of the upper, lower quarter, and middle region of adenoma, respectively, and the inter-group differences were all statistically significant with p≤0.001. The extent of resection for the soft group was significantly greater than that of the hard group (85.3% vs. 70.6%, p=0.011). Analysis of Variance (ANOVA) revealed that the consistency grade was the influencing factor of degree of resection. p=0.003. CONCLUSIONS The TCTI ratio showed a good correlation with pituitary adenoma consistency. We also determined the optimal ratio of the residual adenoma.

Development and validation of a multi-color model using 3-dimensional printing technology for endoscopic endonasal surgical training.

BACKGROUND: The teaching of endoscopic endonasal surgery has always been difficult because of the complex structure of the nasal cavity, and the unique endoscopic view angle and endoscopic surgical tools. In this study, we have designed a 3D printed multi-color model for training of endoscopic endonasal surgery, and obtained preliminary application results. METHODS: The 3D printed model contained facial skin, bony skeleton, internal carotid artery, turbinate, optic chiasm, and a special sellar base with appropriate colors. After it was printed, six otolaryngologists and neurosurgeons assessed the model. Twenty graduate students and residents from otolaryngology or neurosurgery, without prior experience in endoscopic endonasal surgery were recruited and consented for the training. The training results were recorded. The subjective feeling of participants in terms of using 3D printed model in surgical training was investigated after training. RESULTS: All experts strongly agreed or agreed that the 3D printed model has realistic anatomical structure of nasal passage and appropriate colors for different parts, and is a good teaching tool. As the trainees practiced more, the rate and quality of endoscopic operation increased gradually. Compared to the first practice, all recorded training parameters were improved significantly (all P < 0.05). All participants strongly agreed or agreed that they benefited from the training and the 3D printed model can inspire interest and enthusiasm of endoscopic endonasal surgical training. CONCLUSION: This 3D printed model has realistic anatomical structure of nasal passage and appropriate colors for different parts, and could be a good teaching tool of endoscopic endonasal surgery.

Epithelial-mesenchymal transition and clinicopathological correlation in craniopharyngioma.

AIMS: To assess the immunophenotypic changes associated with epithelial-mesenchymal transition (EMT) in craniopharyngioma, especially at the tumour invasive front, and to correlate the findings with clinicopathological features and patient outcomes. METHODS AND RESULTS: Forty-two craniopharyngiomas were investigated for the presence of EMT markers (vimentin, E-cadherin and ß-catenin) by immunohistochemistry and western blot. The relationships between expression of these markers and various clinicopathological indicators and clinical outcomes of the tumours were analysed. There were statistically significant differences in the expression of vimentin and E-cadherin-ß-catenin between adamantinomatous and papillary variants. The expression of vimentin and E-cadherin (but not that of ß-catenin) in whole tumour sections was associated with tumour recurrence, and with postoperative weight and hypothalamic disturbances; the expression of vimentin and E-cadherin-ß-catenin at the tumour invasive front was also associated with tumour recurrence, postoperative weight, and hypothalamic disturbances. The results from western blotting closely matched those of immunohistochemistry. CONCLUSION: Our study demonstrates, for the first time, the potential prognostic implications of vimentin, E-cadherin and ß-catenin expression in craniopharyngiomas. EMT may represent a crucial mechanism in the progression of craniopharyngiomas.

Nicotinic autoreceptor function in rat brain during maturation and aging: possible differential sensitivity to organophosphorus anticholinesterases.

Acetylcholine (ACh) release is modulated pre-synaptically by both muscarinic and nicotinic receptor-mediated processes. While muscarinic autoreceptors inhibit ACh release, nicotinic autoreceptors enhance ACh release and thus disruption of these processes could potentially affect cholinergic toxicity following exposure to anticholinesterases. Marked age-related differences in sensitivity to some organophosphorus (OP) anticholinesterases have been reported. We compared nicotinic autoreceptor function (NAF) during maturation and aging and evaluated its potential modulation by the common OP insecticide, chlorpyrifos (CPF). Cortical synaptosomes were pre-loaded with [3H]choline, superfused (0.6 ml/min) with physiological buffer and [3H]ACh release was evoked with potassium (KCl, 9 mM), with or without co-addition of exogenous ACh to stimulate nicotinic autoreceptors. Fractions of perfusate were subsequently collected and area under the curve (AUC) for [3H] was analyzed by scintillation counting. The difference in evoked release due to co-addition of exogenous ACh was defined as NAF. Under these conditions, atropine (ATR, 0.1 microM) appeared requisite for NAF; thus this muscarinic antagonist was subsequently added to all perfusion buffers. In synaptosomes from adult tissues, exogenous ACh (3-100 microM) significantly increased release in a concentration-dependent manner. The nicotinic antagonist mecamylamine (MEC, 100 microM) substantially reduced the potassium-evoked release elicited by co-addition of ACh (10 microM). Interestingly, the nicotinic agonists nicotine (NIC) and dimethylphenylpiperazinium (DMPP; 0.1-10 microM) had no effect on release. The active metabolite of CPF (i.e. chlorpyrifos oxon (CPO), 1-10 microM) inhibited NAF in vitro. Maturation-related expression of NAF was noted (AUC with co-addition of 10 microM ACh: 7-day rats, 7+/-6; 21-day rats, 44+/-6; 90-day rats, 196+/-37; 24-month rats, 173+/-52). NAF was substantially reduced (67-91%) 96 h after maximum tolerated dosages of CPF in adult and aged rats (279 mg/kg, sc) but not in juveniles (127 mg/kg, sc), even though AChE inhibition was similar among the age groups (>80%). Together these data suggest that NAF is differentially expressed during maturation and that this neuromodulatory process may be selectively altered by some OP insecticides, potentially contributing to age-related differences in response to AChE inhibitors. As NAF has been postulated to be activated under conditions of 'impaired' cholinergic function, selective alteration of this pre-synaptic process by OP anticholinesterases may be also important in age-related conditions associated with cholinergic hypofunction.