Influence of autologous adipose stem cell matrix gel on wound healing and scar hyperplasia of full-thickness skin defects in rabbit ears / 中华烧伤杂志

Objective: To investigate the influence of autologous adipose stem cell matrix gel on wound healing and scar hyperplasia of full-thickness skin defects in rabbit ears, and to analyze the related mechanism. Methods: Experimental research methods were adopted. The complete fat pads on the back of 42 male New Zealand white rabbits aged 2 to 3 months were cut to prepare adipose stem cell matrix gel, and a full-thickness skin defect wound was established on the ventral side of each ear of each rabbit. The left ear wounds were included in adipose stem cell matrix gel group (hereinafter referred to as matrix gel group), and the right ear wounds were included in phosphate buffer solution (PBS) group, which were injected with autologous adipose stem cell matrix gel and PBS, respectively. The wound healing rate was calculated on post injury day (PID) 7, 14, and 21, and the Vancouver scar scale (VSS) scoring of scar tissue formed on the wound (hereinafter referred to as scar tissue) was performed in post wound healing month (PWHM) 1, 2, 3, and 4. Hematoxylin-eosin staining was performed to observe and measure the histopathological changes of wound on PID 7, 14, and 21 and the dermal thickness of scar tissue in PWHM 1, 2, 3, and 4. Masson staining was performed to observe the collagen distribution in wound tissue on PID 7, 14, and 21 and scar tissue in PWHM 1, 2, 3, and 4, and the collagen volume fraction (CVF) was calculated. The microvessel count (MVC) in wound tissue on PID 7, 14, and 21 and the expressions of transforming growth factor β1 (TGF-β1) and α smooth muscle actin (α-SMA) in scar tissue in PWHM 1, 2, 3, and 4 were detected by immunohistochemical method, and the correlation between the expression of α-SMA and that of TGF-β1 in scar tissue in matrix gel group was analyzed. The expressions of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) in wound tissue were detected by enzyme-linked immunosorbent assay on PID 7, 14, and 21. The number of samples at each time point in each group was 6. Data were statistically analyzed with analysis of variance for repeated measurement, analysis of variance for factorial design, paired sample t test, least significant difference test, and Pearson correlation analysis. Results: On PID 7, the wound healing rate in matrix gel group was (10.3±1.7)%, which was close to (8.5±2.1)% in PBS group (P>0.05). On PID 14 and 21, the wound healing rates in matrix gel group were (75.5±7.0)% and (98.7±0.8)%, respectively, which were significantly higher than (52.7±6.7)% and (90.5±1.7)% in PBS group (with t values of 5.79 and 10.37, respectively, P<0.05). In PWHM 1, 2, 3, and 4, the VSS score of scar tissue in matrix gel group was significantly lower than that in PBS group (with t values of -5.00, -2.86, -3.31, and -4.45, respectively, P<0.05). Compared with the previous time point within the group, the VSS score of scar tissue at each time point after wound healing in the two groups was significantly increased (P<0.05), except for PWHM 4 in matrix gel group (P>0.05). On PID 7, the granulation tissue regeneration and epithelialization degree of the wounds between the two groups were similar. On PID 14 and 21, the numbers of fibroblasts, capillaries, and epithelial cell layers in wound tissue of matrix gel group were significantly more than those in PBS group. In PWHM 1, 2, 3, and 4, the dermal thickness of scar tissue in matrix gel group was significantly thinner than that in PBS group (with t values of -4.08, -5.52, -6.18, and -6.30, respectively, P<0.05). Compared with the previous time point within the group, the dermal thickness of scar tissue in the two groups thickened significantly at each time point after wound healing (P<0.05). Compared with those in PBS group, the collagen distribution in wound tissue in matrix gel group was more regular and the CVF was significantly increased on PID 14 and 21 (with t values of 3.98 and 3.19, respectively, P<0.05), and the collagen distribution in scar tissue was also more regular in PWHM 1, 2, 3, and 4, but the CVF was significantly decreased (with t values of -7.38, -4.20, -4.10, and -4.65, respectively, P<0.05). Compared with the previous time point within the group, the CVFs in wound tissue at each time point after injury and scar tissue at each time point after wound healing in the two groups were significantly increased (P<0.05), except for PWHM 1 in matrix gel group (P>0.05). On PID 14 and 21, the MVC in wound tissue in matrix gel group was significantly higher than that in PBS group (with t values of 4.33 and 10.10, respectively, P<0.05). Compared with the previous time point within the group, the MVC of wound at each time point after injury in the two groups was increased significantly (P<0.05), except for PID 21 in PBS group (P>0.05). In PWHM 1, 2, 3, and 4, the expressions of TGF-β1 and α-SMA in scar tissue in matrix gel group were significantly lower than those in PBS group (with t values of -2.83, -5.46, -5.61, -8.63, -10.11, -5.79, -8.08, and -11.96, respectively, P<0.05). Compared with the previous time point within the group, the expressions of TGF-β1 and α-SMA in scar tissue in the two groups were increased significantly at each time point after wound healing (P<0.05), except for the α-SMA expression in matrix gel group in PWHM 4 (P>0.05). There was a significantly positive correlation between the expression of α-SMA and that of TGF-β1 in scar tissue in matrix gel group (r=0.92, P<0.05). On PID 14 and 21, the expressions of VEGF (with t values of 6.14 and 6.75, respectively, P<0.05) and EGF (with t values of 8.17 and 5.85, respectively, P<0.05) in wound tissue in matrix gel group were significantly higher than those in PBS group. Compared with the previous time point within the group, the expression of VEGF of wound at each time point after injury in the two groups was increased significantly (P<0.05), and the expression of EGF was decreased significantly (P<0.05). Conclusions: Adipose stem cell matrix gel may significantly promote the wound healing of full-thickness skin defects in rabbit ears by promoting collagen deposition and expressions of VEGF and EGF in wound tissue, and may further inhibit the scar hyperplasia after wound healing by inhibiting collagen deposition and expressions of TGF-β1 and α-SMA in scar tissue.

Values of Apparent Diffusion Coefficient and Fractional Anisotropy in the Diagnosis of Brucella Spondylitis / 中国医学科学院学报

To compare the differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) between brucella spondylitis (BS) groups at different stages before treatment and the normal control group and to evaluate the change trend of ADC value and FA value at different time points before and after treatment. Totally 53 patients suspected of BS by conventional magnetic resonance imaging (MRI) and later confirmed as BS patients by serological tests were enrolled in this study. These patients underwent conventional MRI and diffusion tensor imaging scans,and the ADC value and FA value were measured. Independent sample test was used to compare the ADC value and FA value between the BS group and the control group,the ADC value and FA value between the BS group at each stage. Repeated measurement ANOV was used to compare the ADC values and FA values at different time points before and after treatment. FA imaging showed that the color code of BS was different from that of the normal control group,and the color code of FA imaging showed increased singal. The ADC values of BS in the acute,subacute,and chronic stages [(1.45±0.02)×10 mm /s,(1.35±0.03)×10 mm /s,(1.26±0.05)×10 mm /s,respectively] were significantly higher than those in the control group [(1.06±0.09) ×10 mm /s](=2.538,=0.009;=1.998,=0.032;=1.575,=0.004),and the FA value (0.55±0.02,0.65±0.03,0.71±0.04,respectively) were significantly lower than those of the control group (0.78±0.02) (=2.440,=0.012; =1.847,=0.041;=2.102,=0.003). Repeated measurement analysis showed that there were statistically significant differences in ADC values and FA values at different time points before and after treatment in the acute,subacute,and chronic stages (ADC:=12.100,<0.001;=8.439,=0.005;=9.704,=0.004,respectively;FA:=7.080,=0.002;=6.607;=0.003;=8.868,=0.001,respectively). The ADC values at different time points after treatment were significantly lower than those before treatment or at a previous time point after treatment (=332.14,<0.001),and the FA values were significantly higher than those before treatment or at a previous time point after treatment (=134.26,<0.001). FA color code can intuitively display differences in BS and normal vertebral bodies and show change of color code before and after treatment. Also,the ADC values and FA values can quantitatively reveal differences between BS and normal vertebral body in different time points and quantify BS vertebral lesion changes before and after treatment. In particular,in BS patients who are recovering from treatment,it can quantify microscopic edema. Therefore,diffusion tensor imaging may be useful objective indicator in evaluating the effectiveness of a specific treatment for BS.

Diffusion Tensor Imaging in Early Diagnosis and Prognostic Prediction of Intervertebral Disc Change in Patients with Brucella Spondylitis / 中国医学科学院学报

Objective To explore the value of fractional anisotropy(FA) and apparent diffusion coefficient(ADC) in the early diagnosis of intervertebral disc change in patients with Brucella spondylitis(BS) and in the assessment of BS disc changes after treatment and to further investigate the imaging features of BS in its acute,subacute,and chronic stages. Methods Totally 60 serologically or pathologically confirmed BS patients who were treated in the First Hospital Affiliated to Hebei North University(n=20) or ZhangJiakou Infectious Diseases Hospital(n=40) were enrolled. BS patients were scanned by CT,magnetic resonance imaging,and diffusion tensor imaging,and the FA and ADC values of the disc were measured using the DTI Fiber Trak package. The FA and ADC values were compared in each period and after treatment. Results The ADC value significantly increased and the FA value significantly decreased in different stages(P<0.01). Six months after treatment,the ADC value was significantly lower than the pre-treatment,and the FA value was significantly increased(P<0.01). The ADC value 12 months after treatment for patients in acute or subacute stage and the FA value 12 months after treatment for patients in all stages were significantly different from those in the 6 month after treatment(P<0.01),and the only exception was that the ADC value in the chronic stage was not significantly different between 12 and 6 month after treatment(P=0.089).Conclusion FA and ADC values are more sensitive than conventional MRI sequences in the diagnosis of BS intervertebral disc change and therefore can be used for the early diagnosis and prognostic prediction.

Enzymatic glycosylation of 4'-demethylepipodophyllotoxin / 中国中药杂志

The glycosides of 4'-demethylepipodophyllotoxin (DMEP) possess various pharmacological activities; however, the chemical synthesis of these glycosides faces challenges in regioselectivity, stereoselectivity, and the protection and de-protection of functional groups. In this work, a novel glycosyltransferase (GT) gene AbGT5 from Aloe barbadensis was successfully cloned, heterogeneously expressed and purified. Recombinant AbGT5 was able to catalyze the glycosylation of DMEP and the glycosylated product, which was separated from the preparative scale reaction, was characterized as DMEP 4'-O-β-D-glucoside via MS, 1H-NMR, 13C-NMR, HSQC and HMBC. According to the investigations of enzyme properties, AbGT5 show the highest activity around 20 ℃ in the buffer of pH 9.0, and it was independent of divalent metal ions. Under the optimum conditions, the conversion rate of DMEP can reach 80%. Above all, in this work the enzymatic glycosylation of DMEP was achieved with high efficiency by the novel GT AbGT5.

Comparison of the pulmonary dead-space fraction derived from ventilator volumetric capnography and a validated equation in the survival prediction of patients with acute respiratory distress syndrome / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>This prospective observational study aims to evaluate the accuracy of dead-space fraction derived from the ventilator volumetric capnography (volumetric CO₂) or a prediction equation to predict the survival of mechanically ventilated patients with acute respiratory distress syndrome (ARDS).</p><p><b>METHODS</b>Consecutive VD/VT measurements were obtained based upon a prediction equation validated by Frankenfield et al for dead-space ventilation fraction: VD/VT = 0.320 + 0.0106 (PaCO₂-ETCO₂)⁺ 0.003 (RR)⁺0.0015 (age) in adult patients who had infection-related severe pneumonia and were confirmed as having ARDS. Here PaCO₂ is the arterial partial pressure of carbon dioxide in mmHg; ETCO₂, the end- tidal carbon dioxide measurement in mmHg; RR, respiratory rate per minute; and age in years. Once the patient had intubation, positive end expiratory pressure was adjusted and after Phigh reached a steady state, VD/VT was measured and recorded as the data for the first day. VD/VT measurement was repeated on days 2, 3, 4, 5 and 6. Meanwhile we collected dead-space fraction directly from the ventilator volu- metric CO₂ and recorded it as Vd/Vt. We analyzed the changes in VD/VT and Vd/Vt over the 6-day period to determine their accuracy in predicting the survival of ARDS patients.</p><p><b>RESULTS</b>Overall, 46 patients with ARDS met the inclusion criteria and 24 of them died. During the first 6 days of intubation, VD/VT was significantly higher in nonsurvivors on day 4 (0.70 ± 0.01 vs 0.57 ± 0.01), day 5 (0.73 ± 0.01 vs. 0.54 ± 0.01), and day 6 (0.73 ± 0.02 vs. 0.54 ± 0.01) (all p =0.000). Vd/Vt showed no significant difference on days 1e4 but it was much higher in nonsurvivors on day 5 (0.45 ± 0.04 vs. 0.41 ± 0.06) and day 6 (0.47 ± 0.05 vs. 0.40 ± 0.03) (both p=0.008). VD/VT on the fourth day was more accurate to predict survival than Vd/Vt. The area under the receiver-operating characteristic curve for VD/VT and Vd/Vt in evaluating ARDS patients survival was day 4 (0.974 ± 0.093 vs. 0.701 ± 0.023, p = 0.0024) with the 95% confidence interval being 0.857-0.999 vs. 0.525-0.841.</p><p><b>CONCLUSION</b>Compared with Vd/Vt derived from ventilator volumetric CO₂, VD/VT on day 4 calculated by Frankenfield et al's equation can more accurately predict the survival of ARDS patients.</p>

Chlorogenic acid alters the voltage-gated potassium channel currents of trigeminal ganglion neurons / 国际口腔科学杂志·英文版

Chlorogenic acid (5-caffeoylquinic acid, CGA) is a phenolic compound that is found ubiquitously in plants, fruits and vegetables and is formed via the esterification of caffeic acid and quinic acid. In addition to its notable biological functions against cardiovascular diseases, type-2 diabetes and inflammatory conditions, CGA was recently hypothesized to be an alternative for the treatment of neurological diseases such as Alzheimer's disease and neuropathic pain disorders. However, its mechanism of action is unclear. Voltage-gated potassium channel (Kv) is a crucial factor in the electro-physiological processes of sensory neurons. Kv has also been identified as a potential therapeutic target for inflammation and neuropathic pain disorders. In this study, we analysed the effects of CGA on the two main subtypes of Kv in trigeminal ganglion neurons, namely, the IK,A and IK,V channels. Trigeminal ganglion (TRG) neurons were acutely disassociated from the rat TRG, and two different doses of CGA (0.2 and 1 mmol⋅L(-1)) were applied to the cells. Whole-cell patch-clamp recordings were performed to observe alterations in the activation and inactivation properties of the IK,A and IK,V channels. The results demonstrated that 0.2 mmol⋅L(-1) CGA decreased the peak current density of IK,A. Both 0.2 mmol⋅L(-1) and 1 mmol⋅L(-1) CGA also caused a significant reduction in the activation and inactivation thresholds of IK,A and IK,V. CGA exhibited a strong effect on the activation and inactivation velocities of IK,A and IK,V. These findings provide novel evidence explaining the biological effects of CGA, especially regarding its neurological effects.