[Prognostic nutritional index application value for acute-on-chronic liver failure co-infection].

Objective: To explore the predictive value of the prognostic nutritional index (PNI) in concurrently infected patients with acute-on-chronic liver failure (ACLF). Methods: 220 cases with ACLF diagnosed and treated at the First Affiliated Hospital of Xi'an Jiaotong University from January 2011 to December 2016 were selected. Patients were divided into an infection and non-infection group according to whether they had co-infections during the course of the disease. Clinical data differences were compared between the two groups of patients. Binary logistic regression analysis was used to screen out influencing factors related to co-infection. The receiver operating characteristic curve was used to evaluate the predictive value of PNI for ACLF co-infection. The measurement data between groups were compared using the independent sample t-test and the Mann-Whitney U rank sum test. The enumeration data were analyzed using the Fisher exact probability test or the Pearson χ(2) test. The Pearson method was performed for correlation analysis. The independent risk factors for liver failure associated with co-infection were analyzed by multivariate logistic analysis. Results: There were statistically significant differences in ascites, hepatorenal syndrome, PNI score, and albumin between the infection and the non-infection group (P < 0.05). Among the 220 ACLF cases, 158 (71.82%) were infected with the hepatitis B virus (HBV). The incidence rate of infection during hospitalization was 69.09% (152/220). The common sites of infection were intraabdominal (57.07%) and pulmonary infection (29.29%). Pearson correlation analysis showed that PNI and MELD-Na were negatively correlated (r = -0.150, P < 0.05). Multivariate logistic analysis results showed that low PNI score (OR=0.916, 95%CI: 0.865~0.970), ascites (OR=4.243, 95%CI: 2.237~8.047), and hepatorenal syndrome (OR=4.082, 95%CI : 1.106~15.067) were risk factors for ACLF co-infection (P < 0.05). The ROC results showed that the PNI curve area (0.648) was higher than the MELD-Na score curve area (0.610, P < 0.05). The effectiveness of predicting infection risk when PNI was combined with ascites and hepatorenal syndrome complications was raised. Patients with co-infections had a good predictive effect when PNI ≤ 40.625. The sensitivity and specificity were 84.2% and 41.2%, respectively. Conclusion: Low PNI score and ACLF co-infection have a close correlation. Therefore, PNI has a certain appraisal value for ACLF co-infection.

[A prospective study on application of human umbilical cord mesenchymal stem cells combined with autologous Meek microskin transplantation in patients with extensive burns].

Objective: To investigate the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) combined with autologous Meek microskin transplantation on patients with extensive burns. Methods: The prospective self-controlled study was conducted. From May 2019 to June 2022, 16 patients with extensive burns admitted to the 990th Hospital of PLA Joint Logistics Support Force met the inclusion criteria, while 3 patients were excluded according to the exclusion criteria, and 13 patients were finally selected, including 10 males and 3 females, aged 24-61 (42±13) years. A total of 20 trial areas (40 wounds, with area of 10 cm×10 cm in each wound) were selected. Two adjacent wounds in each trial area were divided into hUCMSC+gel group applied with hyaluronic acid gel containing hUCMSCs and gel only group applied with hyaluronic acid gel only according to the random number table, with 20 wounds in each group. Afterwards the wounds in two groups were transplanted with autologous Meek microskin grafts with an extension ratio of 1∶6. In 2, 3, and 4 weeks post operation, the wound healing was observed, the wound healing rate was calculated, and the wound healing time was recorded. The specimen of wound secretion was collected for microorganism culture if there was purulent secretion on the wound post operation. In 3, 6, and 12 months post operation, the scar hyperplasia in wound was assessed using the Vancouver scar scale (VSS). In 3 months post operation, the wound tissue was collected for hematoxylin-eosin (HE) staining to observe the morphological changes and for immunohistochemical staining to observe the positive expressions of Ki67 and vimentin and to count the number of positive cells. Data were statistically analyzed with paired samples t test and Bonferronni correction. Results: In 2, 3, and 4 weeks post operation, the wound healing rates in hUCMSC+gel group were (80±11)%, (84±12)%, and (92±9)%, respectively, which were significantly higher than (67±18)%, (74±21)%, and (84±16)% in gel only group (with t values of 4.01, 3.52, and 3.66, respectively, P<0.05). The wound healing time in hUCMSC+gel group was (31±11) d, which was significantly shorter than (36±13) d in gel only group (t=-3.68, P<0.05). The microbiological culture of the postoperative wound secretion specimens from the adjacent wounds in 2 groups was identical, with negative results in 4 trial areas and positive results in 16 trial areas. In 3, 6, and 12 months post operation, the VSS scores of wounds in gel only group were 7.8±1.9, 6.7±2.1, and 5.4±1.6, which were significantly higher than 6.8±1.8, 5.6±1.6, and 4.0±1.4 in hUCMSC+gel group, respectively (with t values of -4.79, -4.37, and -5.47, respectively, P<0.05). In 3 months post operation, HE staining showed an increase in epidermal layer thickness and epidermal crest in wound in hUCMSC+gel group compared with those in gel only group, and immunohistochemical staining showed a significant increase in the number of Ki67 positive cells in wound in hUCMSC+gel group compared with those in gel only group (t=4.39, P<0.05), with no statistically significant difference in the number of vimentin positive cells in wound between the 2 groups (P>0.05). Conclusions: The application of hyaluronic acid gel containing hUCMSCs to the wound is simple to perform and is therefore a preferable route. Topical application of hUCMSCs can promote healing of the autologous Meek microskin grafted area in patients with extensive burns, shorten wound healing time, and alleviate scar hyperplasia. The above effects may be related to the increased epidermal thickness and epidermal crest, and active cell proliferation.

[Interpretation of defeating meningitis by 2030: a global road map].

Meningitis is a life-threatening disease. In order to reduce its threat to public health, the World Health Assembly indorsed a resolution in 2020 for urgent global action to prevent and control meningitis. Defeating Meningitis by 2030: a Global Roadmap was officially launched by the World Health Organization in 2021. We interpreted some key information of the roadmap from the aspects of coverage, objectives and pillar strategies, providing ideas for further strengthening the prevention and control of bacterial meningitis in China.

[The effect of maternal HBV DNA levels on HBV intrauterine transmission and fetal distress].

Aim: To identify the key risk factors of intrauterine hepatitis B virus transmission (HBV) and its effect on the placenta and fetus. Methods: 425 infants born to hepatitis B surface antigen (HBsAg)-positive pregnant women who received combined immunization with hepatitis B immunoglobulin and hepatitis B vaccine between 2009 to 2015 were prospectively enrolled in this study. The intrauterine transmission situation was assessed by dynamic monitoring of infants HBV DNA load and quantitative HBsAg. Univariate and multivariate regression analysis was used to determine the high risk factors for intrauterine transmission. Stratified analysis was used to determine the relationship between maternal HBV DNA load and fetal distress. Transmission electron microscopy was used to observe HBV Effects on placental tissue. Results: HBV intrauterine infection rate was 2.6% (11/425). Multivariate analysis result showed that the maternal HBV DNA load was an independent risk factor for intrauterine infection among infants (P=0.011). Intrauterine infection and distress rate was significantly higher in infants with with maternal HBV DNA>106 IU/ml than those with HBV DNA <106 IU/ml (12.2% vs. 1.8%; χ2=11.275, P=0.006), and (24.4% vs. 16.0%, χ2=3.993, P=0.046). Transmission electron microscopy showed that mitochondrial edema, endoplasmic reticulum expansion and thicker basement membrane were apparent when the maternal HBV DNA>106 IU/ml than that of maternal HBV DNA<106 IU/ml (960 nm vs. 214 nm, Z=-2.782, P=0.005) in the placental tissue. Conclusion: Maternal HBV DNA>106 IU/ml is associated not only with intrauterine infection, but also with increased incidence of intrauterine distress and placental sub-microstructural changes, providing strong clinical and histological evidence for pregnancy avoidance and treatment in this population.

Safety and efficacy of sofosbuvir-based treatment of acute hepatitis C in end-stage renal disease patients undergoing haemodialysis.

BACKGROUND: Hepatitis C virus (HCV) infection in patients undergoing haemodialysis is prevalent and aggressive. The treatment of chronic hepatitis C has been revolutionised by the advent of direct-acting antivirals (DAAs). However, the safety, efficacy, and tolerance of DAAs in the treatment of acute HCV infection in patients with end-stage renal disease who are on haemodialysis are unknown. AIM: To evaluate the safety and efficacy of sofosbuvir plus daclatasvir in this specific, difficult-to-treat population. METHODS: We conducted a prospective and observational study of end-stage renal disease patients who were undergoing haemodialysis and were acutely infected with HCV. Patients received a half dose of sofosbuvir (200 mg) and a full dose of daclatasvir (60 mg) daily. The primary endpoint was the proportion of patients with sustained virological responses (SVRs); the other primary outcomes were safety and tolerability. RESULTS: Thirty-three patients were enrolled in the study. The median HCV RNA viral load at baseline was 6.8 log10 IU/mL. Twenty-four patients were infected with HCV genotype 2a, seven patients with 1b, and two patients with 2a+1b. All patients achieved a SVR at 12 weeks after the end of treatment. The treatment was well tolerated, and there were no drug-related serious adverse events. CONCLUSION: A half dose of sofosbuvir (200 mg once daily) plus a full dose of daclatasvir (60 mg once daily) were suitable for the treatment of acute HCV-infected patients who were undergoing end-stage renal disease and were on haemodialysis.

[Role of enolase 1 in hepatocellular carcinoma and possible mechanism].

Objective: To investigate the role of enolase 1 (ENO1) in hepatocellular carcinoma (HCC) and possible mechanism. Methods: Real-time PCR and Western blot were used to measure the expression of ENO1 in HCC tissue, adjacent tissue, hepatoma cells, and normal hepatocytes. The siRNA interference technique was used for ENO1 knockout in HepG2 cells, and then CCK-8, colony formation assay, and transwell assay were used to measure the proliferation, migration, and invasion abilities of HepG2 cells. Real-time PCR and Western blot were used to measure the expression of proteins and genes involved in the activation of the Notch signaling pathway. The two-independent-samples t test and a one-way analysis of variance were used for comparison. Results: HCC tissue and HepG2 cells had significantly higher expression of ENO1 than adjacent tissue and normal hepatocytes (P < 0.05). There were significant reductions in the proliferation, migration, and invasion abilities of HepG2 cells after siRNA interference (P < 0.05). There were also significant reductions in the expression of N1ICD, snail, slug, HEY1, HES1, and HES5 (P < 0.05). Conclusion: ENO1 may promote the development of HCC, possibly by participating in the regulation of the Notch signaling pathway.

[Effects of change in the activity of vacuolar adenosine triphosphatase of myocardial lysosome on myocardial damage in rats after severe burn and its mechanism].

Objective: To explore the effects of change of activity of vacuolar adenosine triphosphatase (V-ATPase) of myocardial lysosome on myocardial damage in rats after severe burn and its mechanism. Methods: The myocardial lysosomes were extracted from the hearts of 12 SD rats with ultra-high speed gradient density centrifugation, then Western blotting and transmission electron microscope observation were conducted for identification. One hundred and twenty rats were divided into pure burn group, ATP group, normal control group, and bafilomycin group according to the random number table, with 30 rats in each group. Rats in pure burn group and ATP group were inflicted with 40% TBSA full-thickness scald on the back. Immediately after injury, rats in pure burn group were intraperitoneally injected with lactated Ringer's solution in 4 mL·%TBSA(-1)·kg(-1,) and rats in ATP group were intraperitoneally injected with ATP in 0.4 mg/kg at 12 h before burn, immediately after burn, and 12 h after burn. Rats in normal control group did not receive any treatment, and rats in bafilomycin group were intraperitoneally injected with bafilomycin A1 in 0.3 mg/kg at the same time points as those of ATP group. At 24 h after burn, 30 rats from each group were collected for determining activity of V-ATPase of myocardial lysosome with coupled-enzyme assay and the expression of myocardium autophagy-related proteins microtubule-associated protein 1 light chain 3 (LC3) and P62 by Western blotting. Left ventricular arterial blood was collected to detect the content of 5 items of myocardial enzyme spectrum and cardiac troponin T (cTnT). Data were processed with one-way analysis of variance and t test. Results: (1) After identification, both the expression level of lysosome-related membrane protein 1 and purity of lysosome in the sample were high, and the structure of lysosome was intact. (2) At 24 h after burn, the activity values of V-ATPase of myocardial lysosome in rats of pure burn group, ATP group, normal control group, and bafilomycin group were (2.03±0.67), (3.01±0.58), (4.29±0.26), and (1.83±0.52) µmol·mg(-1)·h(-1,) respectively. The activity value of V-ATPase of myocardial lysosome in rats of pure burn group was significantly lower than the values in ATP group and normal control group (with t values respectively 3.14 and 8.87, P values below 0.01). The activity values of V-ATPase of rats in normal control group were significantly higher than those in bafilomycin group (t=11.87, P<0.01). At 24 h after burn, the expressions of myocardial LC3 and P62 in pure burn group were significantly higher than those in ATP group and normal control group (with t values from 3.73 to 5.88, P values below 0.01). The expressions of myocardial LC3 and P62 in normal control group were significantly lower than those in bafilomycin group (with t values respectively 2.64 and 3.07, P<0.05 or P<0.01). At 24 h after burn, the content of 5 items of myocardial enzyme spectrum and cTnT in pure burn group was significantly higher than that in ATP group and normal control group (with t values from 3.24 to 16.72, P values below 0.01). The content of 5 items of myocardial enzyme spectrum and cTnT in normal control group was significantly lower than that in bafilomycin group (with t values from 2.39 to 10. 70, P values below 0.01). Conclusions: The activity of V-ATPase of myocardial lysosome decreased in rats after severe burn, which can result in myocardial damage by inhibiting myocardial autophagy flux.

[Effects and mechanism of allogeneic platelet rich plasma on collagen synthesis in wound healing].

Objective: To investigate the effects and mechanism of allogeneic platelet rich plasma (PRP) on collagen in wound surface at different time. Methods: A total of 50 clean 7-week rats were selected for this study, including 10 rats for platelet-rich blood plasma preparation, 20 rats for PRP group and 20 rats for control group, 0.1 ml allogenic PRP and 0.1 ml saline were smeared respectively on wound surfaces of PRP and control group, wound regeneration and healing were examined. Cellular and histological morphology alteration was observed via Masson staining, type Ⅰ and type Ⅲ collagen protein and mRNA expression level were detected by Western blot and real-time PCR. T test was applied for comparison between two samples and one-way ANOVA was utilized for comparison between two groups. Results: The wound healing rate of PRP group was higher than that of control group on 3(rd,) 6(th,) 10(th) and 15(th) day (30.33±3.35 vs.18.35±2.04, 55.51±2.74 vs.36.83±2.34, 79.64±1.40 vs.56.92±1.44, 86.88±2.12 vs.65.80±1.76) after wound surface formation, there were statistic differences (t=13.66-50.48, all P<0.05). The wound collagen of PRP group form faster and coarser, and the fibers arrayed more densely in Masson staining. The protein expression of type Ⅰ collagen(1.92±0.09 vs.1.18±0.11) and type Ⅲ collagen(1.16±0.05 vs.0.74±0.11) of PRP group were higher than that of control group (t=22.99, P<0.01; t=17.62, P<0.05); the mRNA expression of type Ⅰ collagen(5.17±0.11 vs.1.79±0.18, 6.97±0.09 vs.1.96±0.08, 6.00±0.26 vs.2.10±0.05, 4.95±0.11 vs.3.58±0.09)and type Ⅲ collagen(2.35±0.08 vs.1.44±0.05, 3.08±0.05 vs.1.84±0.06, 3.48±0.07 vs.2.36±0.09, 4.42±0.07 vs.2.77±0.10) were higher than that of control group on 3(rd,) 6(th,) 10(th) and 15(th) day after wound surface formation, there were significant differences (t=43.37-188.37, all P<0.05). Conclusion: The allogeneic platelet rich plasma may promote fibroblasts secreted collagen by activated and releasing all kinds of growth factors, especially type Ⅰ and type Ⅲ collagen to accelerate the wound healing.

[The role of autophagy in the curcumin induced proliferation in human laryngeal cancer Hep2 cell].

Objective:The aim of this study is to study the effect of 3-methyladenine (3-MA) on the autophagy and apoptosis of human laryngeal cancer Hep 2 cells induced by curcumin. Method:The proliferation of human laryngeal cancer Hep2 cells was observed by MTT assay. The autophagy level was detected by AO acridine orange staining. Annexin VFITC/PI double staining was used to detect the apoptosis of Hep2 cells. The expression of LC3, Beclin1, Bcl-2 and Bax protein were detected by Western blot. Result:MTT assay showed that curcumin inhibited the proliferation of Hep2 cells in a dose/time dependent manner. The apoptosis rate of curcumin combined with 3-MA increased (P<0.05). Acridine orange staining showed that 3-MA combined with curcumin could significantly reduce the autophagy level of laryngeal carcinoma Hep2 cells. The expression of Bcl-2, Bclin-1 and LC3 Ⅱ was decreased, while the expression of Bax protein was increased (P<0.05). Conclusion:Curcumin can induce apoptosis of Hep 2 cells and induce the development of protective autophagy. The inhibitory effect of curcumin on the apoptosis of laryngeal carcinoma Hep2 cell line was significantly enhanced by 3-MA.

[Effect of rapamycin on the migration of human epidermal cell line HaCaT and its possible molecular mechanism].

OBJECTIVE: To explore the effects of rapamycin on the migration of human epidermal cell line HaCaT, and to analyze its molecular mechanism. METHODS: HaCaT cells were conventionally cultured with RPMI 1640 culture medium containing 10% fetal calf serum (hereinafter referred to as culture medium). (1) According to the random number table, HaCaT cells in logarithmic phase were divided into control group and 1, 5, 50, 100, 200 nmol/L rapamycin groups, with 6 wells in each group. The cells in rapamycin groups were cultured with culture medium containing rapamycin in corresponding mass concentration, and the cells in control group were cultured with culture medium containing dimethyl sulfoxide (DMSO) instead. After being conventionally cultured for 4 hours, proliferative activity of cells was determined with microplate reader (denoted as absorbance value). (2) HaCaT cells in logarithmic phase were grouped and cultured as that in experiment (1), with 1 well in each group. After being conventionally cultured for 4 hours, range of movement of cells in 3 hours was observed under live cell imaging workstation, and their curvilinear movement speeds were calculated. Then the suitable concentration of rapamycin was selected for experiments (3) and (4). (3) HaCaT cells in logarithmic phase were divided into control group and rapamycin group according to the random number table, with 1 well in each group. The cells in rapamycin group were cultured with culture medium containing 50 nmol/L rapamycin, and the cells in control group were cultured with culture medium containing DMSO. After being conventionally cultured for 4 hours, cells were collected for scratch assay. Wound area was observed at post scratching hour (PSH) 0, 5, 10, and 15, and the migration rates of cells at PSH 5, 10, and 15 were calculated respectively. (4) HaCaT cells in logarithmic phase were grouped and cultured as that in experiment (3), with 1 well in each group. Activity of focal adhesion kinase (FAK) was determined with Western blotting (denoted as the ratio of gray value of phosphorylated FAK to that of FAK). Above-mentioned experiments were independently repeated for three or five times. Data were processed with one-way analysis of variance, LSD test, and t test. RESULTS: (1) Proliferative activity of cells in control group and 1, 5, 50, 100, 200 nmol/L rapamycin groups was respectively 1.22±0.28, 1.29±0.38, 1.12±0.27, 1.20±0.29, 1.15±0.30, 1.39±0.40, without statistically significant differences among these groups (F=2.112, P=0.068). (2) The ranges of movement of cells in 1, 5 nmol/L rapamycin groups were similar to the range of movement of cells in control group, while those of cells in 50, 100, 200 nmol/L rapamycin groups were obviously smaller than the range of movement of cells in control group. There were statistically significant differences in cell curvilinear movement speeds among the 6 groups (F=3.525, P=0.004). The curvilinear movement speeds of cells in 1, 5 nmol/L rapamycin groups were respectively (0.8±0.4) and (0.8±0.8) µm/min, and they were similar to the curvilinear movement speed of cells in control group [(0.9±0.5) µm/min, with P values above 0.05]. The curvilinear movement speeds of cells in 50, 100, 200 nmol/L rapamycin groups were respectively (0.7±0.5), (0.7±0.4), (0.7±0.4) µm/min, and they were significantly lower than the curvilinear movement speed of cells in control group (with P values below 0.01). Thus, 50 nmol/L rapamycin was selected for experiments (3) and (4). (3) Compared with those of control group, wound areas of rapamycin group showed no obvious change at PSH 0 and 5, while they were obviously increased at PSH 10 and 15. At PSH 5, migration rate of cells in control group [(17.5±2.6)%] was similar to that in rapamycin group [(15.8±3.5)%, t=1.951, P>0.05]. Migration rates of cells of rapamycin group at PSH 10 and 15 [(42.5±4.0)% and (71.3±9.2)%, respectively] were obviously decreased as compared with those of control group [(46.9±6.7)% and (88.0±7.7)%, with t values respectively 2.732 and 6.746, P values below 0.01]. (4) Compared with that in control group (0.46±0.14), FAK activity of cells in rapamycin group (0.16±0.08) was significantly down-regulated (t=4.967, P<0.01). CONCLUSIONS: FAK signal pathway is sensitive to rapamycin in HaCaT cells. Inhibition effects of rapamycin on migration of HaCaT cells may be mediated by down-regulated activity of FAK.

Downregulation of miR-181a upregulates sirtuin-1 (SIRT1) and improves hepatic insulin sensitivity.

AIMS/HYPOTHESIS: Sirtuin-1 (SIRT1) is a potential therapeutic target to combat insulin resistance and type 2 diabetes. This study aims to identify a microRNA (miRNA) targeting SIRT1 to regulate hepatic insulin sensitivity. METHODS: Luciferase assay combined with mutation and immunoblotting was used to screen and verify the bioinformatically predicted miRNAs. miRNA and mRNA levels were measured by real-time PCR. Insulin signalling was detected by immunoblotting and glycogen synthesis. Involvement of SIRT1 was studied with adenovirus, inhibitor and SIRT1-deficient hepatocytes. The role of miR-181a in vivo was explored with adenovirus and locked nucleic acid antisense oligonucleotides. RESULTS: miR-181a targets the 3' untranslated region (3'UTR) of Sirt1 mRNA through a miR-181a binding site, and downregulates SIRT1 protein abundance at the translational level. miR-181a is increased in insulin-resistant cultured hepatocytes and liver, and in the serum of diabetic patients. Overexpression of miR-181a decreases SIRT1 protein levels and activity, and causes insulin resistance in hepatic cells. Inhibition of miR-181a by antisense oligonucleotides increases SIRT1 protein levels and activity, and improves insulin sensitivity in hepatocytes. Ectopic expression of SIRT1 abrogates the effect of miR-181a on insulin sensitivity, and inhibition of SIRT1 activity or SIRT1 deficiency markedly attenuated the improvement in insulin sensitivity induced by antisense miR-181a. In addition, overexpression of miR-181a by adenovirus impairs hepatic insulin signalling, and intraperitoneal injection of locked nucleic acid antisense oligonucleotides for miR-181a improves glucose homeostasis in diet-induced obesity mice. CONCLUSIONS/INTERPRETATION: miR-181a regulates SIRT1 and improves hepatic insulin sensitivity. Inhibition of miR-181a might be a potential new strategy for treating insulin resistance and type 2 diabetes.

Polar distribution dynamics of Con A binding sites in embryo sacs is temporally coupled by the fertilization process.

The binding site distribution of concanavalin agglutinin (Con A) and wheat germ agglutinin (WGA) on embryo sacs at various developmental stages of Torenia fournieri L was studied by using a cooled Charge Coupled Device (CCD) and fluorescent Con A and WGA probes. The distribution patterns of Con A and WGA binding sites on embryo sacs changed during the fertilization process. The fluorescent signal indicating Con A binding sites was distributed evenly on the surface of the embryo sac wall before anthesis, was much denser on the micropylar end of the embryo sac wall and looked like a corona on the day of anthesis. After pollination, stronger fluorescence was present on the micropylar end of the embryo sac wall and the filiform apparatus (FA), showing an obvious polar distribution. When the pollen tube entered the embryo sac and reached a synergid, the fluorescence was still concentrated on the micropylar end and FA, and started to appear on the synergid. After fertilization, the polar distribution of the fluorescence gradually disappeared and an even distribution pattern was observed again on the embryo sac wall. These results revealed that the dynamic distribution of Con A binding sites was temporally coupled with the process of fertilization. WGA binding site distribution on the embryo sac was also investigated and showed a simple pattern but also regularly changed during the process of fertilization. The variation of these lectin binding sites during the fertilization process suggests that lectin binding site interactions may play a role in the process.