Objective To establish a scald-induced pain model using a constant-temperature electrical scald instrument in rats.Methods Thirty-six pathogen-free male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into 4 groups (n =9 each) using a random number table: control group (group C), scald for 5 s group (group S5), scald for 10 s group (group S10), and scald for 15 s group (group S15).The rats were anesthetized with intraperitoneal chloral hydrate.In S5, S10 and S15 groups, the plantar surface of the left hindpaw of rats were exposed to a constant-temperature electrical scald instrument (85 ℃) for 5, 10 and 15 s, respectively.The plantar surface of the left hindpaw of rats was exposed to an electrical scald instrument (room temperature) for 10 s in group C.At 1 day before treatment (T0),and 1, 3, 5, 7 and 14 days after treatment (T1-5), the mechanical and thermal pain thresholds were measured.Immediately after treatment, and at 24 h after treatment, the total body condition, wound color, and shape of the margin of the wound were observed and recorded.At 24 h after treatment, 3 rats were randomly sacrificed, and the skin from the plantar surface of the left hindpaw was removed for microscopic examination.Results Compared with group C, the thermal pain threshold at T1-2, and the mechanical pain threshold at T1-3 were significantly decreased in group S5, and the thermal pain threshold,and mechanical pain threshold were significantly decreased at T1-4 in group S10 (P＜0.05).The thermal pain threshold ＞ 25 s, and the mechanical pain threshold ＞30 g at T1-5 in group S15.The swelling in foot was bovious, burn blister appeared, and the degree of damage was aggravated in group S10 compared with S5 and S15 groups.Conclusion The scald-induced pain model is successfully established using a constant-temperature electrical scald instrument in rats.

BACKGROUND: Inhibiting the degradation of extracellular matrix in the intervertebral disc can delay the degenerative process of intervertebral disc. Matrix metalloproteinases-3 (MMP3) is considered as a key enzyme for degradation of extracelular matrix components such as type II collagen and aggrecan.
OBJECTIVE:To construct the short hairpin RNA lentiviral vector targeting human MMP3 gene and to detect its efficiency of gene silence by infecting human degenerative nucleus pulposus cells.
METHODS:According to the human MMP3 mRNA (NM_002422.4) sequence, four groups of the short hairpin RNA gene sequences targeting MMP3 were designed, synthesized and annealed to form double stranded DNA fragments, which were connected with the LV3 vectors digested by BamHI andEcoRI enzymes, and then transfected into the competent cels. The positive clones were identified by PCR, and analyzed by sequencing. The packaging and titer of lentivirus were determined after transfecting 293T cells. Human degenerative nucleus pulposus cels were infected with lentivirus vector, and the transfection efficiency of each group was observed under inverted fluorescence microscope. The interfering efficiency was detected by real time-PCR and western blot at 72 and 96 hours.
RESULTS AND CONCLUSION:The ds-oligo DNA was successfully inserted into the lentiviral vector as confirmed by electrophoresis and sequence analysis. The recombinant lentivirus was harvested from 293T cels with a viral titer of 1-5 ×108 TU/mL. RNA interference targeting the GCC AGG CTT TCC CAA GCA AAT sequences with the highest interfering efficiency in MMP3 gene at 72 and 96 hours resulted in suppression of MMP3 mRNA expression by 98% and 72%, respectively; and at 96 hours, the interfering efficiency of protein expression was 57.2%. The recombinant lentivirus vector containing RNA interference targeting MMP3 gene is successfuly constructed, which lays a foundation for further studies on the MMP3 function and gene therapy.

AIM: To explore the transport and delivery of active drug from dexamethasone-angelica sinensis polysaccharides prodrug in the gastrointestinal tract of rats. METHODS: Dexamethasone and the prodrug were orally administered to rats at the dose of 1.96 mg?kg~ -1 (calculated by carried dexamethasone). The drugs in the plasma and contents of different parts of the rats' gastrointestinal tract were determined by high performance liquid chromatography (HPLC). RESULTS: Dexamethasone carried by the prodrug was mainly released in the contents and mucosa of cecum and colon after oral administration of the prodrug. The absorption of released dexamethasone was reduced significantly. The peak time, peak concentration and AUC were 7.2 h , 42 ?g?L~ -1 and 334 ?g?h?L~ -1 , respectively. However, free dexamethasone was found mainly in the contents and mucosa of the stomach, proximal and distal small intestine after oral administration. The peak time, peak concentration and AUC were 2.2 h, 2 120 ?g?L~ -1 and 11 875 ?g?h?L~ -1 , respectively. CONCLUSION: Dexamethasone can be specifically delivered to the cecum and colon by using dexamethasone- angelica sinensis polysaccharides prodrug. The absorption of dexamethasone was reduced significantly and the drug concentration in colon was increased significantly. The prodrug has a potential in the treatment of colitis.

AIM:To explore the therapeutic effect of dexamethasone Angelica sinensis polysaccharide prodrug(DEX-AP) on trinitrobenzene sulfonic acid(TNBS) induced ulcerative colitis(UC) in rats and its side effects.METHODS: The experimental UC rats were induced by clusis of the solution of TNBS in 45% alcoho1(50(mg?ml~(-1))).The UC rats were orally administrated with(0.25)(?mol?kg~(-1)?d~(-1)) DEX and(0.05),(0.25),(1.25)(?mol?kg~(-1)?d~(-1)) DEX-AP(calculated by carried DEX in DEX-AP) for 7 days,respectively.The rats were killed after the amount of peripheral blood lymphocyte was counted,then the spleen,thymus and colon were separated and weighted.After the ulcerative area of colon was calculated,the colonic myeloperoxidase(MPO) activity was determined and parts of colon were paraffin sectioned and examined under light microscope by HE stain.RESULTS: After the UC rats were administrated with different doses of DEX-AP for 7 days,the ulcerative area,the weight and the MPO activity of colon reduced significantly.The reduction of MPO activity was correlated to the dose of DEX-AP and the MPO activity with DEX-AP at the doses of(0.25),(1.25)(?mol?kg~(-1)?d~(-1)) reduced more significantly than that with DEX at the the dose of(0.25)(?mol?kg~(-1)?d~(-1)).The number of peripheral blood lymphocyte,spleen weight and thymus weight of UC rats reduced significantly at the dose of(0.25)(?mol?kg~(-1)?d~(-1)) DEX(P

Objective:To introduce a novel ridge preservation technique with micro-titanium plate avoiding the use of bone grafting materials,and evaluate the potential horizontal bone preservation effect of this new technique,applied on single maxillary central incisors after tooth extraction for future implant restoration.Methods:Nine patients (six women and three men),mean age (26.0 ±5.7)years(from 1 8 to 34 years)referred to the Department of Oral Implantology,Peking University School and Hospital of Stomotology,were selected and diagnosed with unsalvageable single middle incisor with fine general con-ditions,no signs of acute local inflammation,no ongoing or previous periodontitis,healthy neighboring teeth and intact buccal bone walls.Tooth extraction,delayed implant placement and implant-supported single crown restoration were selected as treatment plan.The teeth were extracted atraumatically with lo-cal anesthesia,followed by a reflection of a minor flap to exposed 2-3 mm of the buccal bone plate.Af-ter that,a micro-titanium plate was trimmed and bended to fit the convexity of the labial bone and fixed by two mini pins with intent to support the labial soft tissue.The flap was then repositioned over the micro titanium plate and secured with two single sutures.No bone grafting materials or releasing incisions were needed.The sockets were left to heal without any intention of primary wound closure.Cone-beam compu-ted tomographic (CBCT)scans were obtained before and four months after tooth extraction.Horizontal ridge widths were measured with CBCT software,and the preservation effects were calculated and recor-ded by the percentage of horizontal ridge alteration.Results:The nine extraction sockets were healed un-eventfully.The average socket width before extraction was (7.51 ±0.48)mm (6.92-7.82 mm).The average alveolar ridge labial-palatal width at the control point of the edentulous area was (6.81 ±0.44) mm (6.04-7.38 mm)4 months after tooth extraction,the mean percentage of ridge width preserved was 90.87%±2.91%(87.28%-95.60%).Conclusion:This novel ridge preservation method by the usage of a micro-titanium plate did not interfere with the natural socket healing process,and at the same time,largely preserved the width of alveolar ridge without any bone grafting procedures.Long term results remain to be seen.

Objective To explore the correlation between TCM constitution and sleep status in escort troops. Methods Standardized TCM Constitution Questionnaire and Pittsburgh Sleep Quality Index (PSQI) were used to investigate escort troops. Factors of PSQI and constitution types were analyzed. Results The results of PSQI showed the number of escort troops who had bad sleeping (PSQI>7) was 64, which accounted for 46%of the escort troops, among which, 45 people (70.3%) were justified as biased constitution, while 19 were normal constitution (29.7%). The top three biased constitution in bad sleeping were:qi deficiency, phlegm-dampness and dampness-heat. PSQI factors such as sleep disorder, daytime dysfunction and total score had positive correlation with qi deficiency, yang deficiency, yin deficiency, dampness-heat and blood stasis, and negative correlation with normal constitution. Conclusion Sleep condition of escort troops has correlation with TCM constitution, which indicates that sleep status could be improved by regulating TCM constitution.

The peripherally inserted central catheter (PICC) in neonates has solved the long-term venous access needs of hospitalized infants in the Neonatal Intensive Care Unit (NICU) . The application of technology is accompanied by the risk of complications. Providing safe and high-quality vascular access for neonates through standardized operations is of great significance. The National Association of Neonatal Nurses (NANN) has formulated the Practice Guideline for PICC in Neonates and revised it into the the Practice Guideline for Peripherally Inserted Central Catheter in Neonates (Third Edition) in 2015, aiming to support the bedside nursing practice of neonatal PICC, reduce the occurrence of complications, and promote neonatal safety. This article interprets the recommended points for early identification, management, and prevention of complications after neonatal PICC catheterization in the guidelines.

Objective To construct and validate a risk prediction model for delayed healing of venous leg ulcer(VLU),so as to provide a reference basis for early identification of people at high risk of delayed healing.Methods Using a convenience sampling method,331 VLU patients attending vascular surgery departments in 2 tertiary A hospitals in Sichuan Province from January 2018 to December 2022 were selected as a modeling group and an internal validation group,and 112 patients admitted to another tertiary A hospital were selected as an external validation group.Risk factors for delayed healing in VLU patients were screened using univariate analysis,LASSO regression,and multivariate logistic regression analysis,and a risk prediction model was constructed using R software,and the predictive effects of the models were examined using the area under the receiver operating characteristic curve,the Hosmer-Lemeshow test,decision curve,and the bootstrap resampling for internal validation and spatial external validation were performed,respectively.Results The predictors that ultimately entered the prediction model were diabetes(OR=4.752),deep vein thrombosis(OR=4.104),lipodermatosclerosis(OR=5.405),ulcer recurrence(OR=3.239),and ankle mobility(OR=5.520).The model had good discrimination(AUC:0.819 for internal validation and 0.858 for external validation),calibration(Hosmer-Lemeshow test:χ2=13.517,P=0.095 for internal validation and χ2=3.375,P=0.909 for external validation)and clinical validity.Conclusion The model constructed in this study has good differentiation and calibration,and it can effectively predict people at high risk of delayed healing of VLU,which facilitates targeted clinical interventions to improve ulcer outcomes and reduce the risk of delayed ulcer healing.

Objective To explore the related risk factors of hypokalemia in elderly patients with acute cerebral hemorrhage(ACH),and construct a risk prediction model based on logistic regres-sion.Methods A total of 190 elderly ACH patients treated in Foshan Hospital of Traditional Chi-nese Medicine from June 2022 to May 2024 were enrolled as study objects,and were divided into hypokalemic group(potassium＜3.5 mmol/L,n=51)and normal group(potassium 3.5-5.5 mmol/L,n=139)according to whether hypokalemia occurred.Logistic regression model was used to analyze the risk factors of hypokalemia in the elderly ACH patients.Based on the identified risk factors,a comprehensive index model was constructed.ROC curve was drawn to analyze the diag-nostic value of the index for occurrence of hypokalemia in the patients.Results Larger female ra-tio,higher NIHSS score at admission,elevated urea nitrogen and blood creatinine at admission,and higher glomerular filtration rate(GFR)≤60 ml/min,and ratio of using hydrochlorothiazide＞20 mg/d were observed in the hypokalemic group than the normal group(P＜0.01).Univariate logistic regression analysis showed that female,NIHSS score at admission,urea nitrogen at ad-mission,serum creatinine at admission,GFR ≤60 ml/min,and hydrochlorothiazide dose＞20 mg/d were risk factors for hypokalemia in the ACH patients(P＜0.05,P＜0.01).Multivariate lo-gistic regression analysis indicated that female,NIHSS score at admission,GFR ≤60 ml/min,and hydrochlorothiazide dose＞20 mg/d were independent risk factors for hypokalemia in the elderly ACH patients(OR=6.393,95％CI:2.138-19.112,P=0.001;OR=3.123,95％CI:2.161-4.513,P=0.000;OR=3.327,95％CI:1.137-9.736,P=0.028;OR=3.111,95％CI:1.083-8.933,P=0.035).ROC curve analysis revealed that the AUC values of female,NIHSS score at admission,GFR,hydrochlorothiazide dose and comprehensive index in predicting hypokalemia in elderly ACH patients were 0.621,0.897,0.601,0.613 and 0.857,with a sensitivity of 52.90％,76.50％,49.00％,54.90％and 72.50％,and a specificity of 71.20％,88.50％,71.20％,67.60％and 87.80％,respectively.Conclusion Female,NIHSS score at admission,GFR ≤60 ml/min,and hydrochlorothiazide dose＞20 mg/d may affect the occurrence of hypokalemia in elderly ACH pa-tients,and our comprehensive index model based on these risk factors has high performance in predicting the occurrence of hypokalemia in elderly ACH patients.

Objective:To explore the effects of foraging exercise (FE) on depressive-like behaviors and expression of transforming growth factor-β1 (TGF-β1) in hippocampus of rats with ischemic stroke after chronic stress.Methods:The right middle cerebral artery occlusion (MCAO) model was used in 30 male adult clean grade SD rats by suture method.According to the body weight, rats were evenly divided into stroke group ( n=10) and chronic unpredictable mild stimulation (CUMS) group ( n=20). Rats of CUMS group received stress induction 1 week after operation and lasted for 3 weeks. Then, according to random number generator of SPSS 24.0 software, the depression rats were divided into post-stroke depression (PSD) group( n=10) and FE groups ( n=10). The FE group received free FE intervention for 4 weeks. Body weight, water maze test, novelty inhibition feeding test (NSFT) and sucrose preference test (SPT) were performed at the end of the 1st, 4th and 8th week, respectively. The expression of TGF-β1 in hippocampus was detected by Immunohistochemistry (IHC) and Western blot (WB), and the levels of TGF-β1 and TNF-α in serum were detected by ELISA. SPSS 24.0 software was used for statistical analysis. The behavioral data were compared by two factor repeated measurement analysis of variance. One way ANOVA was used for comparison among groups, and LSD test was used for further pairwise comparison. Results:(1) The interaction between group and time had statistical significance on body weight, latency and food intake of NSFT and sucrose preference index(SPI) ( F=2.936-12.098, all P<0.05). After 4 weeks, compared with the stroke group((343.80±19.34)g, (12.10±6.97)s, (0.75±0.09)%), the body weight((307.80±17.23)g, (305.30±24.39)g), and SPI((0.52±0.06)%, (0.53±0.07)%) of PSD group and FE group were lower and the NSFT latency((21.70±7.02)s, (22.40±0.84)s) was longer (all P<0.05). After 8 weeks, SPI in FE group was higher than that in PSD group ( P=0.045). There were significant differences in body weight of three groups, NSFT latency and SPI of PSD group and FE group, and food intake of stroke and FE group ( F=8.478-196.548, all P<0.05). There was no interaction between group and time in the water maze test. Main effect of time ( P=0.034) and main effect of group ( P<0.01) had statistical significance on escape latency. The escape latency after 4 weeks was longer than that after 1 week ( P=0.003). The latency of PSD group was longer than that of stroke group ( P=0.005), and latency of FE group was shorter than that of the PSD group ( P<0.01). The main effect of group had statistical significance in the number of crossing quadrant ( P<0.01). The number of crossing quadrant of FE group was less than that of PSD group ( P<0.01). (2) Immunohistoche mistry staining showed that compared with the stroke group, the expression of TGF-β1 was down-regulated in 3 areas of hippocampus of PSD group (CA1, CA3 and DG) ( t=5.449-9.353, all P<0.01). Compared with stroke group, the expression of TGF-β1 of CA1 ( t=7.433, P<0.01) in FE group was down-regulated, but was up-regulated in CA3 ( t=3.342, P<0.05) of FE group. Compared with the PSD group, the expression of TGF-β1 was up-regulated in CA3 and DG of FE group ( t=7.811, 8.790, both P<0.01). (3) Western blot results: Compared with stroke group, the expression of TGF-β1 in hippocampus of PSD group was down-regulated ( t=3.255, P<0.01). Compared with the PSD group, the expression of TGF-β1 in hippocampus of FE group was up-regulated ( t=2.906, P<0.05). (4) ELISA detection showed that compared with the stroke group, the levels of TGF-β1 decreased ( t=2.224, P<0.05), but TNF-α increased ( t=6.127, P<0.01) in PSD group.Compared with the PSD group, the expression of TGF-β1 in FE group increased significantly ( t=4.417, P<0.01). Conclusion:Foraging exercise can improve the depressive behavior symptoms of ischemic stroke rats after chronic stress, and its mechanism may be related to the increasing expression of TGF-β1, which can alleviate the inflammatory reaction in hippocampus.