The emergence of teeth is a complex physiological process characterized by the formation of the tooth crown, its movement towards the occlusal plane, and subsequent penetration through the alveolar bone and oral mucosa to achieve functional positioning for contact with opposing teeth. Parathyroid hormone (PTH) and parathyroid hormone-related peptide (PTHrP) are critical regulators of calcium and phosphorus metabolism in the body, playing significant roles in tooth emergence. Their regulatory functions exhibit intricate temporal and spatial dynamics, with underlying mechanisms that remain incompletely understood. In recent years, an increasing number of researchers both domestically and internationally have investigated the role and mechanisms of PTH/PTHrP in tooth emergence, primarily focusing on aspects such as dental sac formation, basal alveolar bone development, coronal alveolar bone resorption, root formation, and periodontal ligament development. Literature reviews indicate that PTH and PTHrP regulate bone metabolism, coordinate various signaling pathways including OPG/RANK/RANKL, cAMP/PKA, and Wnt/β-catenin, and are allosterically modulated by Ca2+ and ATP. These processes contribute to the development of dental sacs, which transmit signals to recruit osteoclasts and promote the resorption of crown alveolar bone, thereby forming an eruption pathway. Additionally, PTH/PTHrP plays a role in the formation of basal alveolar bone, root development, and the periodontal ligament, generating the force necessary for tooth eruption. Through precise spatiotemporal regulation and coordinated efforts, alveolar bone remodeling is achieved, facilitating the intricate process of tooth eruption. Through stringent temporal regulation and multi-faceted cooperation, remodeling of the alveolar bone occurs to complete this intricate developmental process of tooth emergence. Future research should further elucidate the mechanisms underlying PTH/PTHrP actions while also considering optimal dosage regimens regarding timing and frequency for therapeutic applications.

Organ transplantation is the most effective treatment for all categories of end-stage organ diseases. To resolve the shortage of donors in organ transplantation, widespread attention has been diverted to xenotransplantation. At present, clinicians mainly highlight the problems related to xenotransplantation rejection and viral infection. The physiology of xenotransplantation has been rarely studied. Kidney performs endocrine function by producing erythropoietin (EPO), renin and activating vitamin D. Although these pathways are usually well preserved in allogeneic transplantation, species-specific differences, especially those between pigs and non-human primates, may still affect the physiological function of transplant organs. In this article, the changes of EPO, renin-angiotensin-aldosterone system (RAAS) and active vitamin D₃ of pig and human after xenotransplantation were illustrated, aiming to provide reference for subclinical research of xenotransplantation.

Objective To analyze the status quo and existing problems of radiation protection for veterinary X-ray facilitiesin Beijing-Tianjin region, China, and to provide a basis for improving radiation protection management level. Methods According to the requirements of the Technical guidelines for status quo assessment of occupational hazard of the employing unit (AQ/T 4270—2015), the study performed status quo assessment on the workplaces of veterinary X-ray facilities in 16 pet hospitals in Beijing-Tianjin region, and comprehensively analyzed the impact of the workplaces on the health of radiation workers and the public. Results In terms of personnel management, the pass rates of occupational health management post setting, personnel training, personal protective equipment, individual monitoring of occupational external exposure, notification of occupational hazards, and occupational health surveillance were 100%, 81.3%, 100%, 75%, 37.5%, and 25%, respectively. In terms of workplace management, most workplaces had reasonable layout and zoning and complete protection and emergency devices. However, there were some problems in some places, such as non-standard radiation warning signs, no notice board of occupational hazards, and no radiation protection testing. In terms of document management, all institutions had imperfect system documents. Conclusion The workplaces of veterinary X-ray facilities in 16 institutions basically meet the requirements for radiation protection, but there are also some problems, such as inadequate management of personnel and workplace radiation protection, and imperfect system documents. Institutions should strengthen the study of radiation protection knowledge. The competent authorities should strengthen supervision, formulate corresponding standards for radiation protection, enhance training, and improve the professional level of staff.

Objective To evaluate the current status of radioactive occupational hazards in the construction of some medical institutions in Tianjin, discover existingproblems and deficiencies, and provide a technical basis for radiation protection management. Methods Based on the requirements of relevant regulations and standards, we comprehensivelyevaluated the results of the pre-evaluation and control effect evaluation of 81 radioactive occupational hazards in Tianjin. Results Among the 35 proposed protective measures for pre-evaluation of radiation occupational hazards constructionprojects, the lowest compliance rate is warning signs and personal protective equipment. Among the 46 construction projects of radioactive occupational hazard control evaluation, the pass rate of protective measures was between 73.9% and 100%, with the lowest pass rate for personal protective equipment. Besides, the pass rate of radiation protectionmanagement evaluation was 95.7% ～ 100%, with the lowest pass rate for the protection management system.The initial inspectionpass rateof the equipment quality control acceptancewas 98.6%, while the pass rate was 97.1% for the relevant workplace radiation protection during the initial inspection. Conclusion The pre-evaluation completion rate of radiological occupational hazard evaluation in Tianjin medical institution construction project, unilateral and area of construction room, workplace layout and zoning, ventilation, shielding measures, personal dose management and occupational health inspection all meet the requirements of regulations and standards. However, there are still some deficiencies in the personal protective equipment, warning signs and the radiation protection management system. Therefore, the regulatory department should further strengthen the evaluation of medical institutions, especially the key supervision and management of non-conformities.

ObjectiveThe methods based on bladder cancer markers which could be applied to early diagnosis and postoperative recurrence monitoring of bladder cancer were current research hotspots. This study aims to screen aptamers that specifically recognize human bladder cancer cell lines (EJ, T24, BIU87) through cell-based systematic evolution of ligand by exponential enrichment (CELL-SELEX).MethodsFor CELL-SELEX screening, bladder cancer cell lines EJ, T24, and BIU87 were used as positive control cells. HCV 29 (human normal urothelial cell line), 293T (human embryonic kidney cell line), huh7 (human hepatocellular carcinoma cell line) were used as negative control cells. PCR upstream primers were labeled with FITC, downstream primer was labeled with Biotin. ssDNA fragments collected from each round were amplified by PCR, and the amplified product was then purified using a DNA purification Kit. The biotin-streptavidin magnetic separation methods were used to isolate the PCR product to obtain secondary FITC-ssDNA for the next CELL-SELEX round. The screening process was monitored by flow cytometry. ssDNA pool with the highest binding rates to bladder cancer cell lines(EJ, T24, and BIU87) was selected to PCR amplification, product purification, molecular cloning, and sequencing. According to the sequencing results, the secondary structure of the aptamer was pre-simulated by Dnaman software. Aptamer labeled with FITC was synthesized in vitro, flow cytometry was used to detect the binding rate of the aptamer to bladder cancer cell lins (EJ, T24 and BIU87).ResultsWith the advance of the CELL-SELEX process, the binding rate of FITC-ssDNA to bladder cancer cell lins (EJ, T24, and BIU87) increased gradually. By the 15th round, the binding rate of FITC-ssDNA to EJ cells reached the highest level. The apt1 had the highest enrichment among the 15th round ssDNA pool. By the 18th round, the binding rate of FITC-ssDNA to T24 or BIU87 cells reached the highest level. The apt2 and apt3 had the highest enrichment among the 18th round ssDNA pool. DNA structure prediction showed that the secondary structure of apt1, apt2, and apt3 was mainly stem-loop structure. Flow cytometry showed that the highest binding rate was FITC-apt1 to EJ cells, FITC-apt2 to T24 cells, and FITC-apt3 to BIU87 cells, respectively. There is no significant combination between these aptamers with the negative cells.ConclusionIn this study, three kinds of aptamers with high specificity for bladder cancer cell lines were successfully screened by CELL-SELEX. The apt1 can specifically recognize EJ cells, apt2 can specifically recognize T24 cells and apt3 can specifically recognize BIU87 cells, all of which provide experimental evidence for early diagnosis and targeted therapy technology research of bladder cancer.

Objective:To understand the current status of quality control of medical X-ray diagnostic equipment in Tianjin, discuss the problems existing in the process of quality control, and provide technical basis for the relevant regulatory agencies.Methods:Using stratified random sampling, a total of 401 pieces of medical X-ray diagnostic equipment distributed over 111 medical institutions in Tianjin was used for this study. X-ray multifunctional dosimeters and other types of equipment were used to perform quality control testing and evaluation under the relevant health industry standards.Results:The initial testing pass rate of these equipment was 90.0%, with the pass rates of X-ray imaging equipment lower than those of X-ray fluoroscopy equipment, digital subtraction angiography (DSA) and X-ray computed tomography (CT) ( χ2=9.203, 3.383, 5.754, P<0.05). Among the imaging equipment, the screen X-ray equipment had the lowest pass rate, followed by the breast X-ray equipment and medical digital radiography (DR). The main unqualified items were output repeatability, deviation of tube voltage indication and limit spatial resolution. DR accounted for the highest percentage of X-ray equipment that were below testing condition. The unqualified proportion of X-ray imaging equipment was higher than that of X-ray fluoroscopy equipment ( χ2=8.216, P <0.05). Among the imaging equipment, the screen X-ray equipment was seen to have the highest unaqualified proportion, followed by computed radiography (CR). Among the 401 devices in this study, the initial testing pass rates of private medical institutions was not statistically different from those of public medical institutions ( P>0.05). The initial pass rates of domestic equipment was lower than those of imported equipment ( χ2=4.576, P<0.05). Conclusions:The performance of medical X-ray diagnostic equipment in Tianjin needs to be further improved. Medical institutions should pay attention to the quality control testing of medical X-ray diagnostic equipment. The relevant regulatory agencies should strengthen oversight and management of equipment that contains unqualified items, no baseline values and below the testing conditions.

Recently, liposomes have been widely used in cancer therapeutics, but their anti-tumor effects are suboptimal due to limited tumor penetration. To solve this problem, researchers have made significant efforts to optimize liposomal diameters and potentials, but little attention has been paid to liposomal membrane rigidity. Herein, we sought to demonstrate the effects of cholesterol-tuned liposomal membrane rigidity on tumor penetration and anti-tumor effects. In this study, liposomes composed of hydrogenated soybean phospholipids (HSPC), 1,2-distearoyl--glycero-3-phosphoethanolamine--[methoxy(polyethylene glycol)-2000] (DSPE-PEG) and different concentrations of cholesterol were prepared. It was revealed that liposomal membrane rigidity decreased with the addition of cholesterol. Moderate cholesterol content conferred excellent diffusivity to liposomes in simulated diffusion medium, while excessive cholesterol limited the diffusion process. We concluded that the differences of the diffusion rates likely stemmed from the alterations in liposomal membrane rigidity, with moderate rigidity leading to improved diffusion. Next, the tumor penetration and the anti-tumor effects were analyzed. The results showed that liposomes with moderate rigidity gained excellent tumor penetration and enhanced anti-tumor effects. These findings illustrate a feasible and effective way to improve tumor penetration and therapeutic efficacy of liposomes by changing the cholesterol content, and highlight the importance of liposomal membrane rigidity.

OBJECTIVETo investigate the operation timing of newborns with rectosigmoid Hirschsprung's disease (HD).

METHODSFrom March 2013 to September 2015, 35 newborns diagnosed as rectosigmoid HD in our department were prospectively and randomly divided into 2 groups: less than 3 months treatment group (18 cases) and more than 3 months treatment group (17 cases, conservative treatment for 3 months). They all underwent laparoscopic-assisted transanal endorectal pull-through (LATEP) (modified Soave) procedure. Clinical data, perioperative conditions, postoperative complication, postoperative anal function evaluated by Wingspread score and barium enema were compared between two groups.

RESULTSThe baseline data of two groups were comparable (all P>0.05). All the cases completed single-stage LATEP procedure successfully without conversion to open operation. Compared with more than 3 months treatment group, preoperative bowel preparation time and operation time were significantly shorter [(6.2±3.3) vs. (9.3±4.1) days, P=0.042; (95±15) vs.(121±23) minutes, P=0.029, respectively], intra-operative blood loss was significantly less [(13±3) ml vs. (22±5) ml, P=0.036], length of resected bowel was significantly shorter [(16±5) cm vs.(23±8) cm, P=0.033], and bowel movement recovery time, parenteral nutrition time, hospital stay were also significantly shorter [(2.3±0.5) vs. (2.9±0.6) days, P=0.046; (5.1±2.1) vs. (5.9±2.3) days, P=0.048; (12.9±3.3) vs. (15.8±4.3) days, P=0.049, respectively] in less than 3 months treatment group. No short-term complications, such as anastomotic leak, interlayer infection and abdominal infection occurred in both groups. The follow-up period ranged from 2 months to 24 months. Only the incidence of perianal excoriation was significantly higher in less than 3 months treatment group compared with more than 3 months treatment group [50.0%(9/18) vs. 23.5%(4/17), P=0.045]. Wingspread score results at 6 and 12 months after operation showed excellent rate of postoperative anal function, which was not significantly different between two groups[ <3 months group : 81.3%(13/16) and 92.9%(13/14); >3 months group: 85.7%(12/14) and 92.3%(12/13), all P>0.05]. Postoperative barium enema results at 6 and 12 months after operation all showed normal shape of colon without residue of barium.

CONCLUSIONSFor newborns with rectosigmoid HD, single-stage definitive operation performed at the age less than 3 months has the advantages of shorter preoperative preparation time, less operating injury, shorter resected bowel, and faster postoperative recovery as compared to the age more than 3 months. If rectosigmoid HD is definitively diagnosed, early operation is suggested to perform at the age less than 3 months.

Anastomotic Leak ; Barium Enema ; Blood Loss, Surgical ; Defecation ; Digestive System Surgical Procedures ; Female ; Hirschsprung Disease ; surgery ; Humans ; Infant ; Infant, Newborn ; Intraabdominal Infections ; Laparoscopy ; Length of Stay ; Male ; Operative Time ; Parenteral Nutrition ; Parenteral Nutrition, Total ; Postoperative Complications ; Postoperative Period ; Treatment Outcome

Objective To explore the effect of pleural cavity integrity on respiratory system after off-pump coronary artery bypass grafting (OPCABG),through comparing the respiratory complication after OPCABG.Methods One hundred and two patients were accepted OPCABG,among whom 49 patients' pleural cavities were opened (open group) and 53 patients' pleural cavities were closed (close group).The ventilation time,intensive care unit time,pleural effusion,the rate of atelectasis and respiratory failure after operation were compared between two groups.Results The ventilation time and intensive care unit time in open group were (40.3 ± 4.8) h and (78.3 ± 10.8) h,in open group were (28.6 ± 6.8) h and (54.8 ± 6.1) h.The ventilation time and intensive care time in open group were significantly longer than those in close group(P ＜ 0.01 or ＜ 0.05).The pleural effusion in open group was (800.0 ± 60.5) ml,in close group was (350.0 ± 28.6) ml.The pleural effusion in open group was significantly higher than that in close group (P ＜ 0.01).The rate of postoperative atelectasis and respiratory failure in open group were 36.7％(18/49) and 38.8％(19/49),in close group were 15.1％(8/53) and 18.9％(10/53).The rate of postoperative atelectasis and respiratory failure in open group were significantly higher than those in close group (P ＜ 0.01).Conclusions OPCABG is the operation in mediastinum.To avoid pleural cavity opened in OPCABG can reduce the incidence of postoperative respiratory complication.

Objective To assess the feasibility of anticoagulation therapy after mechanical valve replacement in grass-root health institutions.Methods One hundred and sixty one patients with mechanical valve replacement received anticoagulation therapy with warfarin,including 79 cases receiving the therapy in grass-root health institutions (test group) and 82 cases in the tertiary hospitals (control group).The patients were followed up for 12 months after operation;the rate of anticoagulation efficacy,the anticoagulationrelated complications,and the anticoagulation-related cost were documented and compared between two groups.Results The international normalized ratio (INR) tests were performed for 1 021 times in test group and 717 times were up to anticoagulation standard (70.2 ％,717/1 021),while INR tests in control group were performed for 965 times and 688 times were up to standard (71.3％,688/965);there were no significantly differences in efficacy rate between two groups (P ＞ 0.05).There were no significant differences in rate of bleeding events and thrombosis between two groups [16.5％ (13/79) vs.12.2％ (10/82),6.3％(5/79) vs.4.9％(4/82),respectively,x2 =0.596,P=0.44,x2 =0.161,P=0.69].The anticoagulation-related cost per month and per patient in test group was significantly lower than those in control group [(63.1 ±.12.8) vs.(176.6 ± 16.4) yuan,t =48.716,P ＜0.05].Conclusion Compared with the tertiary hospital,the anticoagulation therapy in grass-root institutions can accomplish the similar clinical outcomes and significantly reduce the medical cost in patients with mechanical valve replacement.