BACKGROUND: Ultrasound-medium frequency electrotherapy has better pain-relieving effect,whether it involves enkephalin and the like neurotransmitter is still not very clear, it is necessary to carry out qualitative and quantitative analysis of the pain response in rats received ultrasound-medium frequency electrotherapy.OBJECTIVE: To investigate the pain-relieving effect of ultrasound-medium frequency electrotherapy and its influence on the enkephalin content in rats, aiming to probe its underlying mechanism and relationship with neurotransmitter enkephalin.DESIGN: Randomly controlled study taking experimental animals as subjects.SETTING: Department of Physiotherapy, First Hospital Affiliated to China Medical University, Institute of Basic Medicine, Peking Union Medical CollegeMATERIALS: This experiment was carried out at the Institute of Basic Medicine, Peking Union Medical College between June 2002 and March 2003. Forty healthy male Wistar rats were adopted and randomized into four groups,namely methionine enkephalin detection experimental group and control group,as well as leucine enkephalin detection experimental group and control group with 10 rats in each group ,amongst which methionine enkephalin experimental group and leucine enkephalin experimental group were generally designed as experimental group ,with the other two group as control group.METHODS: ①Rats ín the experímental group were subjected to ultrasound-medium frequency electrotherapy with frequency of 0.8 MHz in manner of geminal pulse,the modulatìng frequency was 100 Hz and ultrasound intensity of 0.9 W/cm2;the carrier frequency of medium frequency electricity was 4 kHz with modulating frequency of 100 Hz in manner of continuous wave,the electric current of medium frequency was 2 mA and acting time of 10 min. rats in control group received the same dealing,but the higher voltage of ultrasound-medium frequency electrotheprauetic instrument was not used, thereby no energy output was available. tail flick test(TFr) was used to test rat algesthesia,and stopwatch was used to record the time for tail flick(s) that was taken as the value of pain threshold. ②The threshold of pain was tested at 10 minutes instantly after ultrasoundmedium frequency electric stimulation,and then pituitary (removing the posterior pituitary lobe) and hypothalamus were obtained to detect the content of methionine enkephalin and leucine enkephalin by using radioimmuno assay.MAIN OUTCOME MEASURES: The changes of the pain threshold after treatment,the content of methionine enkephalin and leucine enkephalin.RESULTS: Totally 40 rats were enrolled in the experiment and entered in the results analysis. ① The changing rate of pain threshold in two experimental group were 265.79% and 272.90% respectively,the difference was of no statistical significance (P ＞ 0.05). ②After ultrasoundmedium frequency electrotherapy,the content of methionine enkephalin and leucine enkephalin in pituitary and hypothalamus were obviously higher than before treatment [ The changing rate of methionine enkephalin and leucine enkephalin in adenohypophysis was 300.48 ±36.21)% and(204.61±68.65)% , respectively, compared to (239.80±59.98)%and(205.53±51.62)% in hypothalamus, P ＜ 0.05]. ③Linear regression analysis revealed that the variance of the pain threshold was positively correlated with the content of methionine enkephalin in adenohypophysis(r=0.91 ,P ＜ 0.01), suggesting the increment of methionine enkephalin in adenohypophysis was closely connected with the increment of pain threshold,and the level of methionine enkephalin in adenohypophysis would be higher than that in control group by 117.02% when the value of pain threshold increased by100%.CONCLUSION: One of the important mechanisms for the pain-relieving effect of ultrasound-medium frequency electrotherapy might be the increase of methionine enkephalin in adenohypophysis.

OBJECTIVE: To construct a kind of recombinant plasmid PGCsi-AQP1 delivery with DOPC and explore the inhibit effect of laryngeal carcinoma by RNAi targeting AQP1 in vivo. METHOD: Male BALB/c mice, 6 weeks of age transplanted with laryngeal carcinoma cell line Hep-2, four groups were divided randomly: Tail vein injection group (TVIG), Carcinoma around injection group (CAIG), negative control group (NCG) and blank control group (BCG). The recombinant plasmid PGCsi-AQP1 delivery with DOPC were inject into tail vein or surrounding tumor. HE pathological slides and tumor size were observed and inhibitory rate was figured up. The level of AQP1 protein expression and high microvessel density were detected by Immunohistochemical staining (IHC). RESULT: We constructed BALB/c mice models of laryngeal carcinoma successfully (1) HE staining: cell putrescence, nuclear pyknosis and apoptotic bodies were more in the tumor tissues of experimental groups than two control groups. (2) The total volumes of tumor in experimental group were both smaller than in two control groups (P < 0.01). The inhibition rate of TVIG and CAIG were 52.4% and 53.5% respectively and there was no significant difference (P > 0.05). (3) IHC: the AQP1 positive cells and microvessel density in TVIG and CAIG were both less than in two control groups (P < 0.01). CONCLUSION Neutral lipsomes DOPC could help carriaging the recombinant plasmid PGCsi-AQP1 to tumor and then play an inhibit role in laryngeal carcinoma tissue by RNAi targeting AQP1 in vivo.
Animals ; Aquaporin 1 ; therapeutic use ; Cell Line, Tumor ; Laryngeal Neoplasms ; therapy ; Liposomes ; Male ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Plasmids ; RNA Interference ; RNA, Small Interfering ; Random Allocation ; Transfection

Humans ; Rhinitis, Allergic ; diagnosis ; therapy

Objective To investigate the growth curve,breeding rate,and blood physiological and biochemical parameters in Npc1 gene mutant mice (Npc1-/-) for providing theoretical evidence in research on Niemann-Pick disease type C1 (NPC1) patient.Methods 1) The body mass of Npc1-/-,Npc1+/-,and Npc1+/+ mice (n=120;60♀,60♂) was measured from 0 to 77 days;(2) As Npc1-/-mice were born only by the mating Npc1+/-mice,the breeding rate of Npc1+/-mice was counted here from the 1st to 4th generation;(3) The blood physiological and biochemical parameters were measured on both Npc1-/-and Npc1+/+ mice at 60 days.Results 1) Compared with the wild type controls,the body weight of Npc1-/-mice was progressively increased up to 7 weeks and then decreased,and died around 11 weeks.The body weight of the Npc1+/-and Npc1+/+ mice was increased as time went on.After 4 weeks,the male mice showed a higher weight gain than the females;(2) The generations of Npc1+/-mice had no significant difference in mating-parturition interval,litter size,weaning litter and the number of male and female (P>0.05),but the weaning rate of the 2nd generation was significantly higher than that of the 1st generation (P<0.05);(3) The hematological parameters showed a significant difference only in mean corpuscular hemoglobin (MCH) and mean peroxidase index (MPXI) between the Npc1-/-and Npc1+/+ mice (P<0.05).No significant difference was found in other hematological parameters (P>0.05).Among the biochemical parameters,aspartate aminotransferase (AST),glucose (GLU),lactate dehydrogenase (LDH),potassium (K) and copper (Cu) had a significant difference between the Npc1-/-and Npc1+/+ mice (P<0.05).Conclusions 1) The growth curves of Npc1-/-,Npc1+/-,and Npc1+/+ mice are different due to different genotype and sex;(2) The reproduction rates of Npc1+/-mice have no significant difference among different generations;(3) The blood physiological parameters (MCH,MPXI) and biochemical parameters (UREA,AST,GLU,LDH,K,Cu) are significantly different between Npc1-/-and Npc1+/+ mice.

Objective To analyze the impact of artificial intelligence (AI) on colorectal adenoma detection rate (ADR) in fatigue state of endoscopists. Methods A total of 784 patients undergoing colonoscopy at the Endoscopy Center of Hengshui People's Hospital in Hebei Province were enrolled. Patients were divided into group A (n=405, time from 14: 00 to 15: 59) and group B (n=379, time from 16: 00 to 17: 30) based on the operation time. Patients in both groups who underwent AI-assisted examination were included in AI subgroup, while those without AI assistance were included in non-AI subgroup. Baseline data, including age, gender and bowel preparation quality [assessed by the Boston Bowel Preparation Scale (BBPS) score] were collected. The ADR and polyp detection rate (PDR) for colorectal lesions were calculated for both groups, and the ADR was compared between groups with and without AI assistance. Results The overall ADR was 32.10% in the group A, which was higher than 26.91% in the group B, but the difference was not statistically significant (P>0.05). Without AI assistance, the ADR in the group A was 25.85%, which was significantly higher than 17.30% in the group B (P < 0.05). In the group B with AI assistance, the ADR was significantly higher than that in the group A without AI assistance (P < 0.05). Without AI assistance, the PDR in the group A was 33.17%, which was significantly higher than 22.70% in the group B (P < 0.05). After using AI assistance, there was no significant difference in PDR between the two groups (P>0.05). In the group A, the ADR was 38.50% in the AI subgroup (n=200) and 25.80% in the non-AI subgroup (n=205), with a statistically significant difference (P=0.006). In the group B, the ADR was 36.08% in the AI subgroup (n=194) and 17.30% in the non-AI subgroup (n=185), with a statistically significant difference (P < 0.001). Conclusion AI-assisted colonoscopy can effectively improve the ADR of endoscopists under fatigue conditions.

BACKGROUND:With social progress,the incidence rate of knee osteoarthritis is getting higher and higher in the face of the rapidly developing aging problem in the social population,and the number of total knee replacement operations is gradually increasing. OBJECTIVE:To study the relationship between prosthesis size and stress shielding by improving the tibial prosthesis base. METHODS:A female patient with severe knee osteoarthritis was selected.Based on Mimics,through extracting the bone structure of the knee joint and simulating the total knee replacement surgery,osteotomy,positioning,and implantation operations were carried out to establish the geometric modeling of the total knee replacement prosthesis(including the femoral prosthesis,tibial bracket,and tibial pad),and improve the design of the tibial prosthesis base,analyze the effect of different tibial prosthesis bases on stress shielding of surrounding bone tissue. RESULTS AND CONCLUSION:(1)Compared with single-stem tibial intramedullary stem prosthesis,the design of four-post tibial intramedullary stem prosthesis created a certain degree of stress shielding around the short stem.However,compared with a thicker single long stem,this stress shielding effect was significantly reduced,and the load was evenly distributed among the four short stems,so there was no stress concentration at the bottom of the pile.(2)The design with a rectangular hole in the middle not only provided relatively good stability,but also helped to reduce stress shielding of cancellous bone to a certain extent,with a reduction rate of 77.5%.(3)Compared with a single-stem tibial intramedullary stem prosthesis,both the four-post tibial intramedullary stem prosthesis and the four-post tibial intramedullary stem prosthesis with a hole in the middle have good stability,which can reduce stress shielding to a certain extent without causing stress concentration,providing theoretical guidance for the design of the tibial intramedullary stem.

BACKGROUND:Total knee arthroplasty serves as an effective intervention for the treatment of late-stage knee joint disorders.However,prosthetic liners are prone to wear and failure due to internal stress variations,resulting in limited lifespan and decreased postoperative patient activity.Addressing how to enhance prosthetic design to meet a broader range of patient needs constitutes a significant focus in prosthesis research. OBJECTIVE:Based on the morphological design of the meniscus,we propose an asymmetric design prosthesis and compare it with a symmetric posterior stabilized prosthesis.The stress distribution patterns and variations in the contact area of the liners for both prostheses were analyzed to explore whether the asymmetric prosthesis design offers advantages over the symmetric design. METHODS:Using the finite element method,we simulated the osteotomy and prosthesis assembly in a knee osteoarthritis patient.Two different prostheses(asymmetric design and posterior stabilized)were employed to establish post-total knee arthroplasty knee joint models.Under flexion conditions at 0°,10°,20°,and 30°,we investigated the Mises stress on the femoral and tibial components as well as the liner.Additionally,by comparing the contact area on the inner and outer sides of the liner,we aimed to explore the changes in biomechanics and alterations in motion behavior in the post-total knee arthroplasty knee joint. RESULTS AND CONCLUSION:(1)Throughout the flexion range from 0 to 30 degrees,the Mises stress peak on the liner exhibited a trend of initial decrease followed by an increase,with the stress on the medial side consistently surpassing that on the lateral side.(2)In comparison to the posterior stabilized prosthesis,the asymmetrically designed prosthesis demonstrated smaller stress peaks.At a flexion angle of 30 degrees,the Mises stress peak values of the medial and lateral parts of the asymmetric prosthesis were 15.81 MPa and 11.95 MPa,and those of the posterior stabilization prosthesis were 16.70 MPa and 13.76 MPa.The difference of Mises stress on the medial part was 5.33%,and the difference of Mises stress on the lateral part was 13.15%.Comparing the peak Mises stress on the femoral and tibial components,the asymmetric component was always lower than the posterior stable component during knee flexion.(3)In the upright position at 0 degrees,the medial contact area of the posterior stabilization prosthesis was 17.96 mm2,and the lateral contact area was 34.10 mm2.The contact area on the inner and outer sides of the asymmetric design prosthesis liner was 105.47 mm2 and 107.80 mm2,respectively,indicating a larger contact area with a smaller difference between the inner and outer sides.(4)These results suggest that the biomechanical performance of the asymmetric prosthesis is superior,contributing to the maintenance of knee joint stability and improved joint mobility.This design,to a certain extent,mimics the rotational motion mechanism of the knee joint about the medial condyle as an axis,making it a more effective choice for knee joint prosthesis selection.

OBJECTIVECellular senescence as one of the important steps against tumor is observed in many cancer patients receiving chemotherapy and is related to chemotherapeutic response. To investigate the effect of cisplatin on hepatocellular carcinoma, we treated HepG2 cells exhibiting wild-type TP53 with gradient concentrations of cisplatin.

METHODSThe inhibitory effects of cisplatin on human hepatoma HepG2 cells were detected by MTT assay and colony formation test. The changes in cell cycle were analyzed by flow cytometry, and cellular senescence was detected with senescence associated β-galactosidase (SA β-gal) staining. The relative mRNA expression levels of TP53, P21 and P19 was estimated using semi-quantitative real-time RT-PCR, and the protein expressions of P53 and P21 were detected using Western blotting.

RESULTSCisplatin induced irreversible proliferation inhibition and G1 phase arrest of HepG2 cells. Elevated levels of senescence-associated β-galactosidase was observed in HepG2 cells exposed to low doses of cisplatin. P19 expression immediately increased following cisplatin exposure and reached the maximum level at 48 h, followed then by a rapid decrease to the baseline level, whereas the expressions levels of TP53 and P21 mRNA increased continuously. Western blotting confirmed P53 and P21 expression changes similar to their mRNA expressions during cisplatin-induced cellular senescence in HepG2 cells.

CONCLUSIONOur results revealed a functional link between cisplatin and hepatocellular senescence. Cellular senescence induced by cisplatin as a stabile senescent cellular model can be used for further research.

Cell Cycle ; drug effects ; Cell Cycle Checkpoints ; drug effects ; Cellular Senescence ; Cisplatin ; pharmacology ; Cyclin-Dependent Kinase Inhibitor p19 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Hep G2 Cells ; Humans ; Tumor Suppressor Protein p53 ; metabolism ; Up-Regulation

Objective Cellular senescence as one of the important steps against tumor is observed in many cancer patients receiving chemotherapy and is related to chemotherapeutic response. To investigate the effect of cisplatin on hepatocellular carcinoma, we treated HepG2 cells exhibiting wild-type TP53 with gradient concentrations of cisplatin. Methods The inhibitory effects of cisplatin on human hepatoma HepG2 cells were detected by MTT assay and colony formation test. The changes in cell cycle were analyzed by flow cytometry, and cellular senescence was detected with senescence associatedβ-galactosidase (SA β-gal) staining. The relative mRNA expression levels of TP53, P21 and P19 was estimated using semi-quantitative real-time RT-PCR, and the protein expressions of P53 and P21 were detected using Western blotting. Results Cisplatin induced irreversible proliferation inhibition and G1 phase arrest of HepG2 cells. Elevated levels of senescence-associated β-galactosidase was observed in HepG2 cells exposed to low doses of cisplatin. P19 expression immediately increased following cisplatin exposure and reached the maximum level at 48 h, followed then by a rapid decrease to the baseline level, whereas the expressions levels of TP53 and P21 mRNA increased continuously. Western blotting confirmed P53 and P21 expression changes similar to their mRNA expressions during cisplatin-induced cellular senescence in HepG2 cells. Conclusion Our results revealed a functional link between cisplatin and hepatocellular senescence. Cellular senescence induced by cisplatin as a stabile senescent cellular model can be used for further research.