Nanoparticles targeting OPN loaded with BY1 inhibits vascular restenosis by inducing FTH1-dependent ferroptosis in vascular smooth muscle cells.

Vascular restenosis following angioplasty continues to pose a significant challenge. The heterocyclic trioxirane compound [1, 3, 5-tris((oxiran-2-yl)methyl)-1, 3, 5-triazinane-2, 4, 6-trione (TGIC)], known for its anticancer activity, was utilized as the parent ring to conjugate with a non-steroidal anti-inflammatory drug, resulting in the creation of the spliced conjugated compound BY1. We found that BY1 induced ferroptosis in VSMCs as well as in neointima hyperplasia. Furthermore, ferroptosis inducers amplified BY1-induced cell death, while inhibitors mitigated it, indicating the contribution of ferroptosis to BY1-induced cell death. Additionally, we established that ferritin heavy chain1 (FTH1) played a pivotal role in BY1-induced ferroptosis, as evidenced by the fact that FTH1 overexpression abrogated BY1-induced ferroptosis, while FTH1 knockdown exacerbated it. Further study found that BY1 induced ferroptosis by enhancing the NCOA4-FTH1 interaction and increasing the amount of intracellular ferrous. We compared the effectiveness of various administration routes for BY1, including BY1-coated balloons, hydrogel-based BY1 delivery, and nanoparticles targeting OPN loaded with BY1 (TOP@MPDA@BY1) for targeting proliferated VSMCs, for prevention and treatment of the restenosis. Our results indicated that TOP@MPDA@BY1 was the most effective among the three administration routes, positioning BY1 as a highly promising candidate for the development of drug-eluting stents or treatments for restenosis.

Clinical Study of Modified Shenqi Pill （肾气丸） Plus Tongdu Tiaoshen Acupuncture （通督调神针刺） for Neurogenic Bladder After Spinal Cord Injury of Kidney-Yang Deficiency Syndrome / 中医杂志

ObjectiveTo observe the clinical efficacy of modified Shenqi Pill （肾气丸） plus Tongdu Tiaoshen Acupuncture （通督调神针刺） in the treatment of neurogenic bladder after spinal cord injury of kidney-yang deficiency syndrome. MethodsForty-six patients were randomly divided into 23 cases each in the control group and the treatment group. Both groups were given conventional treatment， i.e. oral methylcobalamin tablets （0.5 mg each time， 3 times a day） and paraplegic conventional acupuncture （once a day， 6 consecutive days a week）. The control group was given simple bladder function rehabilitation training on the basis of the conventional treatment； and the treatment group was given modified Shenqi Pill orally （1 dose a day， 150 ml each time， taken warmly in morning and evening） and Tongdu Tiaoshen Acupuncture （once a day， 6 consecutive days per week） in addition to what were given to the control group. The treatment course lasted for 4 weeks. The 24 h urination frequency， 24 h urine leakage frequency， 24 h single urine volume， bladder residual urine volume， international lower urinary tract symptom （LUTS） score， traditional Chinese medicine （TCM） syndrome score were compared between the two groups， and clinical effectiveness and TCM syndrome effectiveness were compared between the two groups after treatment. ResultsTwenty patients in each group were finally analyzed in this study. The number of 24 h urination， the number of 24 h urine leakage， bladder residual urine volume， LUTS score， and the TCM syndrome scores decreased after treatment in both groups， and the 24 h single urine volume increased （P＜0.01）； and much more improvement was found of each index in the treatment group than in the control group （P＜0.05 or P＜0.01）. The total clinical effectiveness and TCM syndrome effectiveness in the treatment group was 85.00% （17/20） respectively， which were statistically significantly higher than 45.00% （the total clinical effectiveness， 9/20） and 60.00% （TCM syndrome effectiveness， 12/20） in the control group （P＜0.01）. ConclusionModified Shenqi Pill plus Tongdu Tiaoshen Acupuncture can signi-ficantly improve the clinical symptoms of neurogenic bladder patients after spinal cord injury of kidney-yang deficiency syndrome， having better effectiveness than simple bladder function rehabilitation training， and its mechanism may be related to the improvement of the injured nerve function innervating the bladder.

Constructing a CdS QDs/silica gel composite with high photosensitivity and prolonged recyclable operability for enhanced visible-light-driven NADH regeneration.

Visible-light-driven nicotinamide adenine dinucleotide (NADH) regeneration is one of the most effective measures, and cadmium sulfide (CdS) materials are typically used as low-cost photocatalysts. The CdS photocatalysts, however, still suffer from low regeneration efficiency and poor cycle stability. In this work, the CdS quantum dots (QDs) less than 10 nm embedded onto silica gel (CdS QDs/Silica gel) were constructed for visible-light-driven NADH regeneration by a successive ionic layer adsorption reaction and ball milling method. Results demonstrate that the photosensitivity of the CdS QDs/Silica gel composite was 31 times higher than that of the bulk CdS. Moreover, the conduction band (CB) edge of the CdS QDs/Silica gel composite is -1.34 eV, which is more negative 0.5 eV than that of the bulk CdS. The obtained CdS QDs/Silica gel composites showed the highest NADH regeneration yields of 68.8% under visible-light (LED, 420 nm) illumination and can be reused for over 40 cycles. Finally, the bioactivity of NADH toward enzyme catalysis is further confirmed by the hydrogenation of benzaldehyde to benzyl alcohol catalyzed with an alcohol dehydrogenase as enzyme catalysis.

Analysis of Radioactive Iodine Trapping Mechanism by Zinc-Based Metal-Organic Frameworks with Various N-Containing Carboxylate Ligands.

This study aimed to develop effective adsorbents for capturing radioactive iodine in nuclear power waste gas. Two zinc metal-organic frameworks (Zn-MOFs) were synthesized and found to have favorable properties such as a large surface area, thermal stability, surface rich in π-electron-containing nitrogen, and redox potential. Adsorption experiments revealed maximum capacities of 1.25 and 1.96 g g-1 for the MOFs at 75 °C, with the pseudo-second-order kinetic model fitting the data well. The Langmuir equation provided a better fit in cyclohexane, with maximum adsorption amounts of 249 and 358 mg g-1 for Zn-MOF-1 and Zn-MOF-2, respectively. The MOFs were also stable during six cycles of adsorption and desorption. Furthermore, electron transfer occurred due to the synergistic adsorption of Zn, N, and O atoms, resulting in the conversion of some iodine to polyiodide. Zn-MOF-2 exhibited better chemisorption than Zn-MOF-1 due to a smaller highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap. Notably, it was discovered that N-containing radicals had stronger interactions with iodine compared to radicals without N. These findings provide valuable insights into MOF synthesis and environmental protection.

A metal-poor star with abundances from a pair-instability supernova.

The most massive and shortest-lived stars dominate the chemical evolution of the pre-galactic era. On the basis of numerical simulations, it has long been speculated that the mass of such first-generation stars was up to several hundred solar masses1-4. The very massive first-generation stars with a mass range from 140 to 260 solar masses are predicted to enrich the early interstellar medium through pair-instability supernovae (PISNe)5. Decades of observational efforts, however, have not been able to uniquely identify the imprints of such very massive stars on the most metal-poor stars in the Milky Way6,7. Here we report the chemical composition of a very metal-poor (VMP) star with extremely low sodium and cobalt abundances. The sodium with respect to iron in this star is more than two orders of magnitude lower than that of the Sun. This star exhibits very large abundance variance between the odd- and even-charge-number elements, such as sodium/magnesium and cobalt/nickel. Such peculiar odd-even effect, along with deficiencies of sodium and α elements, are consistent with the prediction of primordial pair-instability supernova (PISN) from stars more massive than 140 solar masses. This provides a clear chemical signature indicating the existence of very massive stars in the early universe.

G4LDB 2.2: a database for discovering and studying G-quadruplex and i-Motif ligands.

Noncanonical nucleic acid structures, such as G-quadruplex (G4) and i-Motif (iM), have attracted increasing research interests because of their unique structural and binding properties, as well as their important biological activities. To date, thousands of small molecules that bind to varying G4/iM structures have been designed, synthesized and tested for diverse chemical and biological uses. Because of the huge potential and increasing research interests on G4-targeting ligands, we launched the first G4 ligand database G4LDB in 2013. Here, we report a new version, termed G4LDB 2.2 (http://www.g4ldb.com), with upgrades in both content and function. Currently, G4LDB2.2 contains >3200 G4/iM ligands, ∼28 500 activity entries and 79 G4-ligand docking models. In addition to G4 ligand library, we have also added a brand new iM ligand library to G4LDB 2.2, providing a comprehensive view of quadruplex nucleic acids. To further enhance user experience, we have also redesigned the user interface and optimized the database structure and retrieval mechanism. With these improvements, we anticipate that G4LDB 2.2 will serve as a comprehensive resource and useful research toolkit for researchers across wide scientific communities and accelerate discovering and validating better binders and drug candidates.

NF-κB activation impedes the transdifferentiation of hypertrophic chondrocytes at the growth plate of mouse embryos in diabetic pregnancy.

BACKGROUND: Diabetes mellitus could cause numerous complications and health problems including abnormality of endochondral bone formation during embryogenesis. However, the underlying mechanisms still remain obscure. METHODS: Streptozotoci (STZ) was injected to induce pregestational diabetes mellitus (PGDM) mouse model. The femurs of E18.5 mouse embryos from control and PGDM groups were harvested. Morphological staining was implemented to determine the abnormality of the bone development. The expressions of the key genes participating in osteogenesis (e.g., Sox9, Runx2, and Osterix), the NF-κB signaling molecules (e.g., P50, P65, IκBα), and the corresponding regulatory factors (e.g., Bmp2, phospho-p38) were evaluated by immunofluorescence, quantitative PCR and western blot. Finally, in vitro chondrocyte differentiation model was employed to verify the role of NF-κB on the expressions of chondro-osteogenic markers. RESULTS: Alcian blue/alizarin red double staining and H&E staining demonstrated the restriction of skeletal development and relatively extended hypertrophic zone at growth plate in E18.5 STZ-induced diabetic mouse embryos compared to the control. Immunofluorescent staining and qPCR showed that Sox9 expression increased, while Runx2 and Osterix expressions decreased in the growth plate of the offspring of PGDM mice. Immunofluorescence of P65 manifested the activation of NF-κB signaling in growth plate in PGDM mouse embryos. Furthermore, the relatively extended hypertrophic zone was also observed in the growth plate of the NF-κB-activated transgenic mice, as well as the activated p65 up-regulated the expression of Bmp2 and p-p38. In ATDC5 cells, we could observe the high glucose up-regulated the P50 and P65 expressions and down-regulated IκBα expression, but the high glucose-activated NF-κB signaling could be reversed by addition of Bay (inhibitor of NF-κB signaling). The expression changes of Bmp2, Sox9 and Runx2 in presence of high glucose were resumed too. CONCLUSION: Our data revealed that NF-κB signaling was involved in mediation effects of dysfunctional trans-differentiation of hypertrophic chondrocytes in the embryonic growth plate induced by maternal diabetic mellitus.

Reversine suppresses osteosarcoma cell growth through targeting BMP-Smad1/5/8-mediated angiogenesis.

Reversine, or 2-(4-morpholinoanilino)-6cyclohexylaminopurine, is a 2,6-disubstituted purine derivative. This small molecule exhibits tumor-suppressive activities through different molecular mechanisms. In this study, in vitro and in vivo angiogenic models were used to elucidate the effect of Reversine on angiogenesis in the tumor suppression. Firstly, we grafted osteosarcoma-derived MNNG/HOS cell aggregates onto chick embryonic chorioallantoic membrane (CAM) to examine the vascularization of these grafts following Reversine treatment. Following culture, it was determined that Reversine inhibited MNNG/HOS grafts growth, and decreased the density of blood vessels in the chick CAM. We then used CAM and chick embryonic yolk-sac membrane (YSM) to investigate the effects of Reversine on angiogenesis. The results revealed Reversine inhibited the proliferation of endothelial cells, where cells were mainly arrested at G1/S phase of the cell cycle. Scratch-wound assay with HUVECs revealed that Reversine suppressed cell migration in vitro. Furthermore, endothelial cells tube formation assay and chick aortic arch sprouting assay demonstrated Reversine inhibited the sprouting, migration of endothelial cells. Lastly, qPCR and western blot analyses showed BMP-associated Smad1/5/8 signaling expressions were up-regulated by Reversine treatment. Our results showed that Reversine could suppress tumor growth by inhibiting angiogenesis through BMP signaling, and suggests a potential use of Reversine as an anti-tumor therapy.

The Synthesis, Bonding, and Transformation of a Ligand-Protected Gold Nanohydride Cluster.

Gold does not react with H2 to form bulk hydrides. Here we report the synthesis and characterization of a gold nanohydride protected by diphosphine ligands, [Au22 H4 (dppo)6 ]2+ [dppo=1,8-bis(diphenylphosphino)octane]. The Au22 core consists of two Au11 units bonded by eight Au atoms not coordinated by the diphosphine ligands. The four H atoms are found to bridge the eight uncoordinated Au atoms at the interface. Each Au11 unit can be viewed as a tetravalent superatom forming four delocalized Au-H-Au bonds, similar to the quadruple bond first discovered in the [Re2 Cl8 ]2- inorganic cluster. The [Au22 H4 (dppo)6 ]2+ nanohydride is found to lose H atoms over an extended time via H evolution (H2 ), proton (H+ ) and hydride (H- ) releases. This complete repertoire of H-related transformations suggests that the [Au22 H4 (dppo)6 ]2+ nanohydride is a versatile model catalyst for understanding the mechanisms of chemical reactions involving hydrogen on the surface of gold nanoparticles.

Clinical research progress of acupuncture in the treatment of cervical spondylosis / 国际中医中药杂志

Acupuncture has achieved good effect in the treatment of various types of cervical spondylosis, which can alleviate the symptoms of neck pain and vertigo, and improve the blood supply to the brain. In terms of acupuncture location, treatment mainly selects acupoints according to meridians and syndrome differentiation, that is, identifying the diseased meridians and giving acupuncture treatment according to massage along meridians and pressing in the traditional meridian diagnosis method,or taking points according to location, including near and far ends based on meridian theory, acupuncture needlingcorresponding locations of hands and feet based on holographic theory, or taking points according to innervated areas or muscle fibers based on anatomical structure. Acupuncture methods mainly include warming and dredging acupuncture, short needling, fast needling and so on. In addition to filiform needles, floating needles, long needles, electroacupuncture and other special needles arealso usedin clinic.

Analysis on Chemical Constituents in Xiao Chengqitang by UPLC-Q-Orbitrap-MS / 中国实验方剂学杂志

Objective:To rapidly identify the chemical constituents in Xiao Chengqitang by ultra-performance liquid chromatography-quadrupole-electrostatic field orbitrap high resolution mass spectrometry （UPLC-Q-Orbitrap-MS）. Method:The method was established by the Waters CORTECS T3 column （2.1 mm×150 mm， 1.6 μm）， mobile phase was methanol （A）-0.1% formic acid aqueous solution （B） for gradient elution （0-5 min， 3%-21%A； 5-20 min， 21%-36%A； 20-32 min， 36%-50%A； 32-42 min， 50%-62%A； 42-50 min， 62%-85%A； 50-60 min， 85%-95%A）， the flow rate was 0.2 mL·min^-1， and the column temperature was 30 ℃. UPLC-Q-Orbitrap-MS was operated in positive and negative ion modes， the scanning range was 100-1 200 with mode of Full MS/dd-MS²， and the collision energies were 20， 40 eV. The compounds were identified by comparing with reference substances and combining with literature reports and MS database information. Result:A total of 123 components were identified in Xiao Chengqitang， including 33 flavonoids， 25 anthraquinones and anthrones， 23 phenylpropanoids， 15 tannins， 10 nitrogen-containing components and 17 other components. Among them， 32 components were determined by reference substances. Conclusion:The material basis of Xiao Chengqitang is flavonoids， anthraquinones and anthrones， phenylpropanoids， which is derived from Aurantii Fructus Immaturus，<italic> </italic>Rhei Radix et Rhizoma and Magnoliae Officinalis Cortex， respectively.

Comparison of two vasopressor protocols for preventing hypotension post-spinal anesthesia during cesarean section: a randomized controlled trial / 中华医学杂志(英文版)

BACKGROUND@#Norepinephrine infusion decreases hypotension after spinal anesthesia during cesarean section. This study aimed to compare the efficacy of norepinephrine infusion and ephedrine bolus against post-spinal hypotension in parturients.@*METHODS@#In this double-blinded, randomized controlled clinical trial, parturients scheduled for elective cesarean section were randomly allocated to receive norepinephrine infusion (0.05 μg·kg-1·min-1) just before spinal anesthesia continuing for 30 min or ephedrine bolus (0.15 mg/kg) just before spinal anesthesia. A rescue bolus (5 μg norepinephrine for the norepinephrine group, and 5 mg ephedrine for the ephedrine group) was administered whenever hypotension occurred. Our primary outcome was the incidence of hypotension within 30 min of spinal anesthesia administration. Secondary outcomes included maternal and neonatal outcomes 30 min after spinal block, and neonatal cerebral oxygenation 10 min after birth.@*RESULTS@#In total, 190 patients were enrolled; of these patients, 177 were included in the final analysis. Fewer patients suffered hypotension in the norepinephrine group than in the ephedrine group (29.5% vs. 44.9%, odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.28-0.95, P = 0.034). Moreover, the tachycardia frequency was lower in the norepinephrine group than in the ephedrine group (OR: 0.22, 95% CI: 0.11-0.44, P < 0.001), and patients suffered less nausea and vomiting (OR: 0.28, 95% CI: 0.11-0.70, P = 0.004). There was no difference in Apgar scores and umbilical arterial blood gas analysis between the two groups. However, neonatal cerebral regional saturations were significantly higher after birth in the norepinephrine group than in the ephedrine group (mean difference: 2.0%, 95% CI: 0.55%-3.45%, P = 0.008).@*CONCLUSION@#In patients undergoing elective cesarean section with spinal anesthesia, norepinephrine infusion compared to ephedrine bolus resulted in less hypotension and tachycardia, and exhibited potential neonatal benefits.@*TRIAL REGISTRATION@#ClinicalTrials.gov, NCT02542748; https://clinicaltrials.gov/ct2/show/record/NCT02542748.

Nitrogen-containing flavonoid and their analogs with diverse B-ring in acetylcholinesterase and butyrylcholinesterase inhibition.

In this study, a series of new flavones (2-phenyl-chromone), 2-naphthyl chromone, 2-anthryl-chromone, or 2-biphenyl-chromone derivatives containing 6 or 7-substituted tertiary amine side chain were designed, synthesized, and evaluated in acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition. The results indicated that the alteration of aromatic ring connecting to chromone scaffold brings about a significant impact on biological activity. Compared with flavones, the inhibitory activity of 2-naphthyl chromone, 2-anthryl-chromone derivatives against AChE significantly decreased, while that of 2-biphenyl chromone derivatives with 7-substituted tertiary amine side chain is better than relative flavones derivatives. For all new synthesized compounds, the position of tertiary amine side chain obviously influenced the activity of inhibiting AChE. The results above provide great worthy information for the further development of new AChE inhibitors. Among the newly synthesized compounds, compound 5a is potent in AChE inhibition (IC50 = 1.29 ± 0.10 µmol/L) with high selectivity for AChE over BChE (selectivity ratio: 27.96). An enzyme kinetic study of compound 5a suggests that it produces a mixed-type inhibitory effect against AChE.

Light-controllable metasurface for microwave wavefront manipulation.

Applying multiple physical fields to artificial manipulate electromagnetic waves is a highly stirring research. In this paper, we creatively combine light control with microwave scattering, realizing an optically coding metasurface for beam deflection based on anomalous reflection. A photoresistor and a voltage-driven module are connected to control each row of PIN-diode-loaded unit cells, endowing the reflection phase of the elements with a strong dependence on light. Owing to the high sensitivity of photoresistor, the digital element state "0" or "1" can be switched effectively via light variation sensed by the photoresistor. By modulating the light signal, the arrangement of digital elements can be reprogrammed, generating the specific scattering field. Therefore, the electromagnetic field can be determined by the spatial distribution of light, which induces the connect with the optical information and microwave field. The simulated and experimental results demonstrate the feasibility of our design. This light-steering approach provides a dimension for electromagnetic wave modulation.

Halogen effects on the electronic and optical properties of Au13 nanoclusters.

We report an experimental and theoretical investigation of the electronic and optical properties of a series of icosahedral Au13 nanoclusters, protected using different halogen ligands (Cl, Br, and I), as well as 1,2-bis(diphenylphosphino)ethane (dppe) ligands. All three clusters are comprised of the same Au13 kernel with two halogens coordinated to the poles of the icosahedral cluster along with five dppe ligands. UV-vis absorption spectra indicate a systematic red shift from Cl to Br to I, as well as a sudden enhancement of the second excitonic peak for the I-coordinated cluster. Density functional theory (DFT) calculations suggest that all clusters possess a wide HOMO-LUMO energy gap of ∼1.79 eV and are used to assign the first two excitonic bands. Frontier orbital analyses reveal several HOMO → LUMO transitions involving halogen-to-metal charge transfers. For the I-coordinated cluster, more complicated I-to-metal charge transfers give rise to different excitation features observed experimentally. The current findings show that halogen ligands play important roles in the electronic structures of gold clusters and can be utilized to tune the optical properties of the clusters.

Animal experiment of magnetic anchor device on lung surface / 中华胸心血管外科杂志

Objective:To verify the feasibility of a self-designed laparoscopic magnetic anchoring device for assisting thoracoscopic wedge resection.Methods:Six healthy Beagle dogs were selected as animal models, and underwent thoracoscopic wedge resection after general anesthesia. We replaced the pulmonary forceps with a magnetic anchoring device to complete the traction exposure of the lobes, and recorded the operation time of the operation, the amount of intraoperative blood loss, and the safety and feasibility of the magnetic anchoring device.Results:Six Beagle dogs successfully completed a thoracoscopic wedge resection with the aid of a magnetic anchoring device. During the operation, the magnetic anchoring device can completely replaced the exposure function of the pulmonary forceps, effectively eliminating the " chopstick effect" between the instruments during the uniportal video-assisted thoracoscopic operation. The magnetic anchoring device provided sufficient traction for the surgery to achieve a clear exposure of the field. Tissue damage and magnetic anchoring pliers slip did not occur during the operation. The operation time was(22.67±3.25)min(range 18-26 min), and the intraoperative blood loss was less than 10 ml. The experimental animals survived well after surgery.Conclusion:Magnetic anchoring device is safe and effective for thoracoscopic wedge resection, which can eliminate mutual interference between operating instruments and has potential for clinical application.

Establishment of gastrointestinal anastomosis by magnetic compression technique in rabbits / 中华消化内镜杂志

Objective:To study the feasibility of establishing gastrointestinal anastomosis by magnetic compression technique in rabbits.Methods:Ten healthy New Zealand rabbits were selected as models for gastrointestinal anastomosis by magnetic compression technique. Daughter and parent magnets suitable for gastrointestinal anastomosis in rabbits were designed and manufactured. A daughter magnet was inserted into the stomach through the purse fistula in the lack of blood vessel area of gastric body, and was pushed into the duodenum along the intestinal tract. And then a parent magnet was inserted through the stomach fistula. The daughter and parent magnets were automatically attracted and pressed the gastric and intestinal walls after they were adjusted in the proper position. The stomach fistula was closed with purse string suture. After ischemia, necrosis, detachment of the tissues between magnets, gastrointestinal anastomosis was established, and the magnets and necrotic tissues were expelled together from the body through the digestive tract. Survival of experimental animals was observed. Anastomotic specimens were obtained one month after operation. The blasting pressure of anastomotic stoma was measured, and the healing of anastomotic stoma was observed with naked eyes.Results:According to the pre-designed operative route, 10 New Zealand rabbits all successfully completed the operation and survived one month after surgery. No complications occurred during perioperative period. The operation time was 35.80±4.71 min (range 28.00-43.00 min), and the magnet discharge time was 11.40±1.56 days (range 9.00-14.00 days). Anastomotic specimens were obtained one month after the operation. Gross observation showed that the anastomotic stoma of gastrointestinal bypass anastomosis healed well, and the surrounding tissues adhered slightly. The anastomotic bursting pressure was 103.00±7.95 mmHg (range 94.00-113.00 mmHg) (1 mmHg=0.133 kPa).Conclusion:The establishment of gastrointestinal anastomosis by magnetic compression technique in rabbits is simple and effective.

Study of colorectal neoplasms localization based on magnetic tracer technique in an animal model / 中华消化内镜杂志

Objective:To design magnets to locate colorectal neoplasms based on magnetic tracer technology, and to test its feasibility and safety by animal experiments.Methods:The magnets used for endoscopic localization of colorectal tumors consist of a tracer magnet and a pursuit magnet, both of which are ring-shaped Nd-Fe-B magnets. Eight healthy Beagle dogs were used as animal models. Tumor locations were assumed in the different parts of the colon and rectum under colonoscopy. The tracer magnet was sent to the hypothetical tumors by endoscopic soft tissue clamp and fixed near the tumors. After 24 hours, laparoscopic surgery was performed under general anesthesia. The pursuit magnet was inserted near the resected colon or rectum through the main operating hole. The tracer magnet was absorbed to the pursuit magnet to identify the location of tumors.Results:The tracer magnet and pursuit magnet were successfully designed and processed. The suction force between the tracer magnet and the pursuit magnet at zero distance was 16 N. All the 8 Beagle dogs successfully received indwelling of magnets under colonoscopy, and no magnets fell off after 24 hours. After the placement of pursuit magnet under laparoscopy, the two magnets attracted each other rapidly and accurately, and successfully completed localization of tumor site without any damage during the operation.Conclusion:Colonoscopy combined with laparoscopy for colorectal neoplasms localization based on magnetic tracer technique is simple, accurate, safe and feasible.

Experimental study of stomach tumor localization based on magnetic tracer technique / 中华普通外科杂志

Objective To verify the feasibility and safety of stomach tumor marker localization based on magnetic tracer technique in dogs.Methods Six male Beagle dogs were examined by gastroscopy.Then tracer magnets were sent to the "tumor" locations assumed in advance and fixed near the "tumors" by endoscopic soft tissue clamp.Laparoscopic gastric tumor localization was performed under general anesthesia 24 hours later.The tracer magnet was placed near the tumor on the surface of the stomach through the operating hole after the conventional establishment of laparoscope puncture parallel mirror to explore the tracer magnet.After the two magnets were attracted,the location of the tracer magnet seen under the laparoscope was the location of the gastric tumor,so as to complete the labeling and positioning of the lesion.Results All the 6 Beagle dogs were successfully implanted with tracer magnets under gastroscopy.Twenty-four hours after the gastroscopy,the pursuit magnet was successfully implanted during laparoscopic surgery.The two magnets automatically attracted each other and formed a sandwich structure of "tracer magnet-gastric wall-pursuit magnet ",which completed the location and identification of gastric tumor under the laparoscopy.Conclusion Gastroscopy combined with laparoscopy based on magnetic tracer technique is simple,accurate,safe and feasible.