Estimation of genotoxicity threshold induced by acute exposure to neodymium nitrate in mice using benchmark dose / 环境与职业医学

Background The benchmark dose (BMD) method calculates the dose associated with a specific change in response based on a specific dose-response relationship. Compared with the traditional no observed adverse effect level (NOAEL) method, the BMD method has many advantages, and the 95% lower confidence limit of benchmark dose lower limit (BMDL) is recommended to replace NOAEL in deriving biological exposure limits. No authority has yet published any health-based guideline for rare earth elements. Objective To evaluate genotoxicity threshold induced by acute exposure to neodymium nitrate in mice using BMD modeling through micronucleus test and comet assay. Methods SPF grade mice (n=90) were randomly divided into nine groups, including seven neodymium nitrate exposure groups, one control group (distilled water), and one positive control group (200 mg·kg−1 ethyl methanesulfonate), 10 mice in each group, half male and half female. The seven dose groups were fed by gavage with different concentrations of neodymium nitrate solution (male: 14, 27, 39, 55, 77, 109, and 219 mg·kg−1; female: 24, 49, 69, 97, 138, 195, and 389 mg·kg−1) twice at an interval of 21 h. Three hours after the last exposure, the animals were neutralized by cervical dislocation. The bone marrow of mice femur was taken to calculate the micronucleus rate of bone marrow cells, and the liver and stomach were taken for comet test. Results The best fitting models for the increase of polychromatophil micronucleus rate in bone marrow of female and male mice induced by neodymium nitrate were the exponential 4 model and the hill model, respectively. The BMD and the BMDL of female mice were calculated to be 31.37 mg·kg−1 and 21.90 mg·kg−1, and those of male mice were calculated to be 58.62 mg·kg−1 and 54.31 mg·kg−1, respectively. The best fitting models for DNA damage induced by neodymium nitrate in female and male mouse hepatocytes were the exponential 5 model and the exponential 4 model, respectively, and the calculated BMD and BMDL were 27.15 mg·kg−1 and 11.99 mg·kg−1 for female mice, and 16.28 mg·kg−1 and 10.47 mg·kg−1 for male mice, respectively. The hill model was the best fitting model for DNA damage of gastric adenocytes in both female and male mice, and the calculated BMD and BMDL were 36.73 mg·kg−1 and 19.92 mg·kg−1 for female mice, and 24.74 mg·kg−1 and 14.08 mg·kg−1 for male mice, respectively. Conclusion Taken the micronucleus rate of bone marrow cells, DNA damage of liver cells and gastric gland cells as the end points of genotoxicity, the BMDL of neodymium nitrate is 10.47 mg·kg−1, which can be used as the threshold of genotoxic effects induced by acute exposure to neodymium nitrate in mice.

Effect of neodymium-doped:yttrium aluminum perovskite laser combined with two kinds of remineralizers on remineralization of early enamel caries / 中国组织工程研究

BACKGROUND:In recent years,a variety of lasers have been widely used in various diseases related to stomatology,including the prevention and treatment of dental caries. OBJECTIVE:To investigate the effect of neodymium-doped:yttrium aluminum perovskite(Nd:YAP)laser combined with two remineralizers on early enamel caries in vitro. METHODS:Early enamel caries models in vitro were artificially established by 60 enamel blocks and randomly divided into 6 groups(n=10).Group A did not undergo any treatment but underwent extracorporeal pH circulation.Group B underwent remineralization of dentin(the main component of casein phosphopeptide-amorphous calcium phosphate composite)and extracorporeal pH circulation.Group C underwent remineralization treatment of Sensodyne toothpaste(the main component of bioactive glass)and then underwent extracorporeal pH circulation.Group D received Nd:YAP laser irradiation and extracorporeal pH circulation.Group E was treated with Nd:YAP laser irradiation,with remineralization of dentin,and then with extracorporeal pH circulation.In group F,Nd:YAP laser irradiation was performed,and then Sensodyne toothpaste was used for remineralization,and the extracorporeal pH circulation was performed;the remineralization treatment was conducted twice a day,and the experimental period was 20 days.Group G was a normal control group,without caries or remineralization,but only underwent extracorporeal pH circulation.After the experiment,the microhardness,morphology and Ca/P ratio of the dental enamel surface were measured in each group. RESULTS AND CONCLUSION:(1)The surface microhardness value of dental enamel in groups B,C and D was higher than that in group A(P<0.000 1);the surface microhardness value of dental enamel in groups E and F was significantly higher than that in groups B,C and D(P<0.000 1),and the surface microhardness value of dental enamel in group F was significantly higher than that in group E(P<0.000 1).(2)Scanning electron microscopy showed that there were a lot of demineralized pores on the enamel surface of group A.There were mineral deposits on the enamel surface of group B,which were uneven and loose.In group C,there were a lot of mineral deposits on the enamel surface,and demineralized pores were found between the calcified masses.The enamel surface of group D was relatively flat;the demineralized pores were significantly smaller than that of group A,and the enamel column interstitium was damaged.In group E,the mineral deposits on the enamel surface were thicker and the demineralized pores were significantly reduced.The mineralized substances deposited on the enamel surface of group F were most dense and uniform and the demineralized pores were small.(3)The Ca/P ratio on the enamel surface of groups B and C was significantly higher than that of group A(P<0.000 1);the Ca/P ratio on the enamel surface of group E was significantly higher than that of groups B,C and D(P<0.000 1),and the Ca/P ratio on the enamel surface of group F was higher than that of group E(P<0.001).(4)These findings indicate that bioactive glass,casein phosphopeptide-amorphous calcium phosphate composite,and Nd:YAP laser after enamel demineralization can promote the remineralization of early enamel caries.Nd:YAP laser combined with bioactive glass or casein phosphopeptide-amorphous calcium phosphate composite can further strengthen the remineralization of dental enamel caries,and the combination of Nd:YAP laser and bioactive glass has the best effect.

The complication rate following Neodymium-doped Yttrium Aluminum Garnet laser posterior capsulotomy for posterior capsular opacification in patients with and without comorbidities

Purpose: To study the complication rate following Nd: YAG posterior capsulotomy posterior capsular opacification (PCO) in patients with and without comorbid conditions. Methods: This was a prospective, interventional, comparative, and observational study. A total of 80 eyes, consisting of 40 eyes without ocular comorbidities (group A) and 40 eyes with ocular comorbidities (group B) that were being treated with Nd: YAG capsulotomy for PCO, were included. Visual outcome and complications of Nd: YAG capsulotomy were studied. Results: The mean age of group A patients was 61.65 ± 8.85 years and that of group B patients was 63 ± 10.46 years. Of the total, 38 (47.5%) were men and 42 (52.5%) were women. In group B, the ocular comorbidities were moderate nonproliferative diabetic retinopathy (NPDR) (n = 14 eyes; 14/40 = 35%), subluxated intraocular lens (IOL; <2 clock hours of subluxation; n = 6), age?related macular degeneration (ARMD; n = 6), post?uveitic eyes (having old signs of uveitis, no episode of uveitis since the last 1 year; n = 5), and operated cases of traumatic cataract (n = 4). The mean energy required in groups A and B was 46.95 ± 25.92 and 42.62 ± 21.85 mJ, respectively (P = 0.422). The average energy requirement in Grade 2, Grade 3, and Grade 4 PCO was 22.30, 41.62, and 79.52 mJ, respectively. An increase in intraocular pressure (IOP) of >5 mmHg from pre?YAG levels was observed in one patient in each group on day 1 postprocedure, for which medical treatment was given to both patients for 7 days. One patient in each group had IOL pitting. No patient had any other complications attributable to ND:YAG capsulotomy. Conclusion: Nd:YAG laser posterior capsulotomy is a safe procedure for PCO in patients with comorbidities. Visual outcomes were excellent after Nd:YAG posterior capsulotomy. Although a transient increase in IOP was noted, the response to treatment was good and a long?term increase in IOP was not observed

The role of Keap1/Nrf2/HO-1 signal pathway in liver injury induced by rare earth neodymium oxide in mice / 中华劳动卫生职业病杂志

Objective: To investigate the role of Keap1/Nrf2/HO-1 signaling pathway in liver injury induced by neodymium oxide (Nd(2)O(3)) in mice. Methods: In March 2021, forty-eight SPF grade healthy male C57BL/6J mice were randomly divided into control group (0.9% NaCl), low dose group (62.5 mg/ml Nd(2)O(3)), medium dose group (125.0 mg/ml Nd(2)O(3)), and high dose group (250.0 mg/ml Nd(2)O(3)), each group consisted of 12 animals. The infected groups were treated with Nd(2)O(3) suspension by non-exposed tracheal drip and were killed 35 days after dust exposure. The liver weight of each group was weighed and the organ coefficient was calculated. The content of Nd(3+) in liver tissue was detected by inductively coupled plasma mass spectrometry (ICP-MS). HE staining and immunofluorescence was used to observe the changes of inflammation and nuclear entry. The mRNA expression levels of Keap1, Nrf2 and HO-1 in mice liver tissue were detected by qRT-PCR. Western blotting was used to detect the protein expression levels of Keap1 and HO-1. The contents of catalase (CAT), glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD) were detected by colorimetric method. The contents of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by ELISA. The data was expressed in Mean±SD. Two-independent sample t-test was used for inter-group comparison, and one-way analysis of variance was used for multi-group comparison. Results: Compared with the control group, the liver organ coefficient of mice in medium and high dose groups were increased, and the Nd(3+) accumulation in liver of mice in all dose groups were significantly increased (P<0.05). Pathology showed that the structure of liver lobules in the high dose group was slightly disordered, the liver cells showed balloon-like lesions, the arrangement of liver cell cords was disordered, and the inflammatory exudation was obvious. Compared with the control group, the levels of IL-1β and IL-6 in liver tissue of mice in all dose groups were increased, and the levels of TNF-α in liver tissue of mice in high dose group were increased (P<0.05). Compared with the control group, the mRNA and protein expression levels of Keap1 in high dose group were significantly decreased, while the mRNA expression level of Nrf2, the mRNA and protein expression levels of HO-1 were significantly increased (P<0.05), and Nrf2 was successfully activated into the nucleus. Compared with the control group, the activities of CAT, GSH-Px and T-SOD in high dose group were significantly decreased (P<0.05) . Conclusion: A large amount of Nd(2)O(3) accumulates in the liver of male mice, which may lead to oxidative stress and inflammatory response through activation of Keap1/Nrf2/HO-1 signal pathway. It is suggested that Keap1/Nrf2/HO-1 signal pathway may be one of the mechanisms of Nd(2)O(3) expose-induced liver injury in mice.

Modification of m6 A in human embryonic lung fibroblasts induced by neodymium oxide exposure and its mechanism / 环境与职业医学

Background Occupational and environmental particulate matter may cause fibrosis, accompanied by RNA m6A modification changes. Neodymium oxide (Nd2O3) can cause mouse lung fibrosis, which contains a large number of fibroblasts. Objective To investigate m6A modification of tumor necrosis factor receptor-associated protein 6/nuclear factor-κB (TRAF6/NF-κB) signaling pathway in fibrosis of human embryonic lung fibroblasts induced by Nd2O3, and identify the key m6A modification sites of TRAF6. Methods Designed concentrations of Nd2O3 (0, 1.563, 3.125, 6.25, 12.5, 25, 50, 100, and 200 mg∙L−1) were infected with HELF cells for 24 and 48 h, and cell viability was detected to determine exposure time and dose. Measurements included indicators of fibrosis [hydroxyproline (HYP) and transforming growth factor-β1 (TGF-β1)], m6A methylation level, methyltransferases (METTL3 and METTL14), demethylases (FTO and ALKBH5), reading proteins (YTHDC2 and YTHDF2), fibrosis-associated genes (collagen-І, vimentin, and α-SMA), and proteins related to signaling pathway (TRAF6, NFKB1, P65, and P-P65). The enrichment of m6A in TRAF6 mRNA was measured by methylated RNA immunoprecipitation-quantitative real-time PCR (MeRIP-qPCR). Results The results of cell viability indicated that 6.25, 12.5, 25 mg∙L−1 Nd2O3 and 48 h exposure time were used for subsequent experiments. After 48 h exposure, compared with the control group, the HYP level in the 25 mg∙L−1 Nd2O3 group was increased, and the levels of TGF-β1 in the 6.25, 12.5, and 25 mg∙L−1 Nd2O3 groups were increased (P<0.05); the overall m6A methylation levels of HELF cells in the 12.5 and 25 mg∙L−1 Nd2O3 groups were increased (P<0.05). At mRNA level, compared with the control group, the mRNA expression levels of methyltransferases METTL3 and METTL14 (6.25, 12.5, and 25 mg∙L−1 Nd2O3) were increased (P<0.05); the mRNA expression level of reading protein YTHDF2 (6.25, 12.5, and 25 mg∙L−1 Nd2O3) was increased (P<0.05), while the mRNA expression level of YTHDC2 (25 mg∙L−1 Nd2O3) was decreased (P<0.05); the mRNA expression levels of demethylases FTO (12.5 and 25 mg∙L−1 Nd2O3) and ALKBH5 (25 mg∙L−1 Nd2O3) were decreased (P<0.05); the mRNA expression levels of fibrosis-related genes vimentin, α-SMA, and collagen-Ⅰ (6.25, 12.5, and 25 mg∙L−1 Nd2O3) were increased (P<0.05); the mRNA expression levels of pathway-related genes TRAF6 (25 mg∙L−1 Nd2O3) and NFKB1 (12.5 and 25 mg∙L−1 Nd2O3) were increased (P<0.05). At protein level, compared with the control group, the expression levels of methyltransferases METTL3 (25 mg∙L−1 Nd2O3) and METTL14 (12.5 and 25 mg∙L−1 Nd2O3) were increased (P<0.05); the expression level of reading protein YTHDF2 (12.5 and 25 mg∙L−1 Nd2O3) was increased, while the expression level of YTHDC2 (25 mg∙L−1 Nd2O3) was decreased (P<0.05); the expression level of demethylase FTO (25 mg∙L−1 Nd2O3) was decreased (P<0.05); the expression level of fibrosis-associated protein vimentin was increased at 25 mg∙L−1 Nd2O3, and the expression levels of α-SMA and collagen-Ⅰ were increased at 12.5 and 25 mg∙L−1 Nd2O3 (P<0.05); the expression levels of TRAF6 and P-P65 were increased at 25 mg∙L−1 Nd2O3 (P<0.05). The MeRIP-qPCR results showed that compared with the control group, the concentrations of m6A in all Nd2O3 groups were significantly increased (P<0.05). Conclusions Upon exposure of HELF cells to Nd2O3, the alterations in fibrosis-related indexes increase the expression of some m6A methylases and decrease the expression of demethylases, thereby increasing the m6A methylase level, and may promote the progression of fibrosis by activating the TRAF6/NF-κB signaling pathway.

Effect of Neodymium-Doped Yttrium Aluminum Garnet Laser Combined With Desensitizing Toothpaste on Dentinal Tubule Occlusion Against Acid Challenge / 中国医学科学院学报

Objective To assess the effects of different application sequences of neodymium-doped yttrium aluminum garnet(Nd∶YAG)laser and the desensitizing toothpaste containing stannous fluoride on dentinal tubule occlusion.Methods Twelve intact third molars freshly extracted from human were selected and prepared into dentin slices with a thickness of 0.8 mm.Each dentin slice was subdivided into four small slices,three of which were etched with 6% citric acid and randomly assigned to the following three groups(n=12):(1)control group:no treatment;(2)Nd∶YAG+toothbrushing(TB)group:first irradiated with Nd∶YAG laser and then brushed with desensitizing toothpaste;(3)TB+Nd∶YAG group:first brushed with desensitizing toothpaste and then irradiated with Nd∶YAG laser.The Nd∶YAG laser irradiation were carried out at 1 W,15 pulses/s,and the pulse width of 150 μs for 10 s(for a total of 6 cycles).After the above treatment,the 12 dentin slices from the Nd∶YAG+TB and TB+Nd∶YAG groups were randomly assigned to four subgroups(n=3)and subjected to acid etching in the Coca-Cola solution for 0,5,10,and 15 min.A scanning electron microscope was used to observe and photograph the dentin slices in each group,and eight single-blinded examiners scored the slices according to uniform criteria.The analysis of variance was carried out to compared the scores between groups.Results Before acid etching,the dentin tubule occlusion scores of the Nd∶YAG+TB and TB+Nd∶YAG groups were(4.83±0.09) scores and(3.85±0.66) scores,respectively,which had no significant difference between each other(P=0.0590)and were higher than that[(0.10±0.07)scores]of the control group(both P<0.0001).The dentin tubule occlusion scores of the Nd∶YAG+TB group after acid etching for 5,10,and 15 min were(4.33±0.60)scores,(4.27±0.24)scores,and(3.63±0.07)scores,respectively,which were not significantly different from those[(4.04±0.10)scores,(3.76±0.59)scores,and(3.17±0.29)scores,respectively]of the TB+Nd∶YAG group(all P>0.05).In the Nd∶YAG+TB subgroup,the dentin tubule occlusion score after acid etching for 15 min was significantly lower than that before acid etching(P=0.0011).In the TB+Nd∶YAG group,there was no statistically significant difference in the score between before and after acid etching(P>0.05).Conclusions Nd∶YAG laser irradiation with appropriate parameters combined with the use of desensitizing toothpaste could produce an excellent occluding effect on dentinal tubules regardless of the sequence.However,brushing with desensitizing toothpaste followed by Nd∶YAG laser irradiation produced more consistent dentin sealing after acid etching.

Study of end-to-end magnetic anastomosis technique of infrahepatic inferior vena cava in rats / 器官移植

Objective To develop a magnetic anastomosis device for infrahepatic inferior vena cava and verify its feasibility and safety in rat models. Methods According to the anatomical characteristics of rat inferior vena cava, a magnetic device suitable for end-to-end anastomosis of infrahepatic inferior vena cava was designed and manufactured. The device consisted of the inner and outer rings. The inner ring was a coated neodymium-iron-boron magnetic ring, and the outer ring was made of polyetheretherketone by 3D printing. Ten fine holes are evenly distributed on the outer ring, of which 5 fine holes were used to load the fine needles, and the other 5 fine holes were mutually connected with the fine needles of the contralateral anastomosis ring during anastomosis. The outer ring was uniformly loaded with fine needles and then bonded with the inner ring to form a magnetic anastomosis complex. Bilateral ends of vessels passed through the anastomosis ring and were fixed to the fine needles, and then end-to-end vascular anastomosis was performed by mutual attraction of two magnetic anastomosis rings. Twenty SD rats were selected and received end-to-end anastomosis of infrahepatic inferior vena cava with magnetic anastomosis device. The time of vascular occlusion, postoperative survival, postoperative anastomotic patency, gross observation and histological examination of anastomotic stoma were analyzed. Results All rats successfully completed end-to-end magnetic anastomosis of the infrahepatic inferior vena cava, and the time of vascular occlusion was 4~6 min. One rat died at 10 d after operation, and the other rats survived within postoperative 2 months. The patency rates of anastomotic stoma in surviving rats at postoperative 1 d, 3 d, 1 month and 2 months were 100%, 100%, 95% and 95%, respectively. At 2 months after operation, no obvious displacement and angulation of the anastomosis device were seen. No signs of corrosion and cracking of the anastomosis rings were observed. No evident hyperplasia and edema of surrounding tissues were noted. Bilateral ends of vessels were completely healed, and no obvious stenosis or thrombosis was found at the anastomotic stoma. Histological examination showed high continuity of bilateral vascular walls of anastomotic stoma, the inner surface of anastomotic stoma was covered by endothelial cells, and no thrombus or fibrous tissue was attached. Conclusions It is safe and feasible to utilize the self-designed magnetic anastomosis device to perform end-to-end magnetic anastomosis of infrahepatic inferior vena cava in rat models.

Ingesta de cuerpos extraños magnéticos en la edad pediátrica. Caso clínico de localización y extracción endoscópica con ayuda de un imán / Ingestion of magnetic foreign bodies during the paediatric age. Case report, location and endoscopic extraction aided by a magnet

La ingesta accidental de más de un imán puede producir complicaciones graves. Los protocolos actuales recomiendan la extracción endoscópica de ser posible. El objetivo de este trabajo es presentar un caso clínico de una ingesta de dos imanes y la técnica endoscópica de extracción. Niño de 11 años que acudió a Urgencias tras la ingesta de dos imanes, asintomático. En la radiografía de abdomen, se identificaron dos cuerpos extraños radiopacos, aparentemente unidos, en la cámara gástrica. Se realizó una endoscopía bajo anestesia general en quirófano. Para facilitar la extracción, se colocó, encima de la pared abdominal, a nivel gástrico, un imán de neodimio. En la endoscopía, se observaron dos pequeños imanes localizados y fijados en la cara anterior del estómago. Una vez localizados, se retiró el imán externo y se procedió a su extracción con cesta

The ingestion of more than one magnet can cause multiple complications. Current protocols recommend endoscopic extraction if possible. We report a patient who swallowed two magnets and the endoscopic extraction technique. An 11-yearold boy presented at the Emergency Room after ingesting two small magnets, being asymptomatic. In the abdominal x-ray two radiopaque bodies were identified at the gastric chamber, apparently together. A gastroscopy was done in the operating room under general anaesthesia. To enable the extraction, a neodymium magnet was placed externally at the abdominal wall. In the endoscopic image, the two magnets were fixed to the anterior gastric wall. Once located, the neodymium magnet was removed and the two magnets were retrieved with an endoscopic basket.

Development of a microcomposite with single-walled carbon nanotubes and Nd2O3 for determination of paracetamol in pharmaceutical dosage by adsorptive voltammetry / 药物分析学报

This study presents for the first time a new composite of carbon paste (CP), single-walled carbon na-notubes (SWCNTs) and Nd2O3 (NdOX). This versatile composite (NdOX-SWCNT/CPE) was applied to the oxidation of paracetamol (PCM). The newly formed surface was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The re-sults showed greater conductivity and a higher surface area for the composite than those of the carbon paste alone. Moreover, the anodic peak currents for PCM increased from 1.6 to 3.6 mA with CPE and NdOX-SWCNT/CPE, indicating an increase of nearly 51.0％ for the anodic peak current. On the other hand, the anodic peak potentials shifted from 0.67 to 0.57 V. The detection limits were 0.05 mmol/L with NdOX-SWCNT/CPE and 0.50 mmol/L with SWCNT/CPE. The relative standard deviations (RSDs) were 1.5％(n =7). The accuracy and interference of the methods were evaluated with a urine chemistry control spiked with known quantities of PCM, uric acid, dopamine, ascorbic acid, caffeine, acetylsalicylic acid, tartrazine, sunset yellow, allure red, rutin, morin and metal ions. Finally, the novelty and usefulness of the composite were evaluated to quantify PCM in pharmaceutical dosage forms such as tablets, powders and syrups for children.

Comparison of the Neodymium-doped Yttrium Aluminum Garnet Capsulotomy Rate with Viscoimplantation and the Hydroimplantation Intraocular Lens Technique

PURPOSE: To investigate the rate of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy in the hydroimplantation intraocular lens (IOL) technique. METHODS: This retrospective study was comprised of 6,192 eyes in 3,790 patients who underwent surgery from January 2013 to September 2017 and then were followed up for at least 1 year. The eyes of these patients were divided into two groups: either viscoimplantation or hydroimplantation. The follow-up examinations were carried out on the 1st day, 4th day, 1st month, and 3 months to 1 year postoperatively. The Nd:YAG capsulotomy rates were evaluated by the different IOL implantation techniques and IOL materials. RESULTS: The mean follow-up duration of the patients was in the viscoimplantation group 14.85 ± 2.43 and 15.05 ± 1.93 months in the hydroimplantation group. The Nd:YAG capsulotomy rate was significantly lower in the hydroimplantation group compared with the viscoimplantation group for the entire hydrophilic IOL model (p < 0.001). In addition, the Nd:YAG rate was lower in the hydroimplantation group that used a hydrophilic IOL than it was in the viscoimplantation group, which used a hydrophobic IOL. CONCLUSIONS: The hydroimplantation technique reduced the Nd:YAG capsulotomy rate.

Non-Surgical Management of Gastroduodenal Fistula Caused by Ingested Neodymium Magnets / 대한소아소화기영양학회지

Foreign body ingestions pose a significant health risk in children. Neodymium magnets are high-powered, rare-earth magnets that is a serious issue in the pediatric population due to their strong magnetic force and high rate of complications. When multiple magnets are ingested, there is potential for morbidity and mortality, including gastrointestinal fistula formation, obstruction, bleeding, perforation, and death. Many cases require surgical intervention for removal of the magnets and management of subsequent complications. However, we report a case of multiple magnet ingestion in a 19-month-old child complicated by gastroduodenal fistula that was successfully treated by endoscopic removal and supportive care avoiding the need for surgical intervention. At two-week follow-up, the child was asymptomatic and upper gastrointestinal series obtained six months later demonstrated resolution of the fistula.

Toxic effects of nano-sized neodymium oxide on central nervous system in mice / 中国职业医学

OBJECTIVE: To investigate the toxic effects of nano-sized neodymium oxide( nano-Nd_2O_3) on the central nervous system in mice. METHODS: Specific pathogen free female ICR mice were randomly divided into control group,lowdose group and high-dose group,with 12 rats in each group. The mice in low-dose group and high-dose group were treated with nano-Nd_2O_3 by nasal drip method at 80 and 160 mg/( kg·d) body weight for 30 days,while the mice in the control group were given 0. 9% sodium chloride solution. The water maze experiment and jump platform experiment were used to evaluate learning and memory ability. Hippocampus was examined using Hematoxylin-Eosin( HE) staining and glial fibrillary acidic protein( GFAP) immunohistochemical staining. The level of malondialdehyde( MDA) and the activity of total superoxide dismutase( T-SOD) in brain tissue were detected by microplate reader. RESULTS: The escape latency increased and the step down latency decreased in the low-dose group and high-dose group compared with the control group(P < 0. 05). No obvious pathological changes were observed by HE staining in brain hippocampus. Immunohistochemistry staining showed that the expression of GFAP protein in the hippocampal astrocytes of the low-and high-dose groups was higher than that in the control group,especially in the high-dose group,when compared with the control group. The MDA level increased and the T-SOD activity decreased in the low-and high-dose groups compared with the control group( P <0. 05). CONCLUSION: nano-Nd2 O3 can reduce the learning and memory ability of mice and increased GFAP expression in hippocampal astrocytes. The mechanism may be related to oxidative stress.

A Case of Late-onset Capsular Block Syndrome, Resulting in the Misdiagnosis of Intraocular Lens Opacity

PURPOSE: We report a case of late-onset capsular block syndrome, which resulted in a misdiagnosis of intraocular lens (IOL) opacity. CASE SUMMARY: A 59-year-old man visited our clinic with reduced visual acuity in the right eye from 1 year prior. He had undergone uncomplicated bilateral cataract surgery by phacoemulsification with IOL implants at another hospital 10 years before. There was no specific history with the exception of hypertension. After being diagnosed in the ophthalmology clinic with IOL degeneration and opacity in the right eye, he was referred to our hospital for IOL replacement. Upon examination, his right uncorrected visual acuity was 0.06 and intraocular pressure was 22 mmHg. The refractive error could not be checked due to IOL opacity. Slit-lamp microscopy revealed a cloudy, milky IOL. Anterior-segment optical coherence tomography of the right eye showed retention of a highly reflective material in the lens capsule behind the IOL. Posterior capsule enlargement of the right eye was confirmed on ultrasound biomicroscopy. After neodymium-doped yttrium aluminium garnet (Nd:YAG) laser capsulotomy was performed, the homogeneous space disappeared and the eye recovered normal visual acuity. CONCLUSIONS: Capsular block syndrome is a rare complication that can occur shortly (1 day to 2 days) after cataract surgery. Late-onset capsular block syndrome, which occurs 10 years after surgery differs from typical clinical manifestations. Thus, capsular block syndrome is an important consideration upon the presentation of opacification due to IOL degeneration.

Damaging effect of nano-neodymium oxide on PC12 cells / 中国职业医学

OBJECTIVE: To study the damaging effect of nano-neodymium oxide( Nano-Nd_2O_3) on rat adrenal pheochromocytoma cell PC12. METHODS: PC12 cells in the logarithmic growth phase were divided into control group and 7 drug treatment groups. The control group was not treated with Nano-Nd_2O_3. The drug treatment groups were treated with 7 different dosing with the final mass concentrations of 3. 13,6. 25,12. 50,25. 00,50. 00,75. 00,100. 00 mg/L of NanoNd_2O_3 for 24 hours,then the follow-up selected experimental concentration were 3. 13,6. 25,12. 50,25. 00,50. 00 and75. 00 mg/L. The CCK-8 essay was used to detect the cell viability. The levels of glutathione( GSH) and superoxide dismutase( SOD) in the cells were measured by enzyme-linked immunosorbent assay. The expression of B cell lymphoma-2( Bcl-2),Bcl-2 associated X protein( Bax) and Caspase-3 protein were detected by Western blot. RESULTS: The survival rate,GSH level and Bcl-2/Bax ratio of PC12 cells decreased with the increase of the Nano-Nd_2O_3 dose,and showed doseresponse relationship( P < 0. 01). The SOD activity of PC12 cells in Nano-Nd_2O_3 group of 12. 50,25. 00,50. 00 and75. 00 mg/L were lower than that of control group( P < 0. 05). The ratio of Caspase-3/β-actin in PC12 cells was higher than that in control group( P < 0. 05). In the range of 0. 00-25. 00 mg/L of Nano-Nd_2O_3,with the increase of NanoNd_2O_3 dose,the ratio of Caspase-3/β-actin in PC12 cells increased gradually,and showed a dose-response relationship( P < 0. 01). CONCLUSION: Nano-Nd_2O_3 can induce oxidative stress in PC12 cells,leading to the decrease of Bcl-2/Bax ratio,activate Caspase-3 expression,and than inhibits cell proliferation in a dose-dependent manner.

Intense Pulsed Light and Q-Switched 1,064-nm Neodymium-Doped Yttrium Aluminum Garnet Laser Treatment for the Scarring Lesion of Discoid Lupus Erythematosus

Discoid lupus erythematosus (DLE) is a chronic form of cutaneous lupus that can cause permanent scarring. Treatment of DLE includes protection from sunlight and artificial sources of ultraviolet light, as well as systemic and topical medications. The first-line standard therapies are antimalarials and topical steroids. Other systemic therapies include systemic steroid, azathioprine, dapsone, and immunosuppressive agents. Topical tacrolimus and pimecrolimus have also been evaluated. Recent studies reported that several treatments, including pulsed dye laser, CO₂ laser, intense pulsed light (IPL), and 1,064-nm long-pulse neodymium-doped yttrium aluminum (Nd:YAG) have been used for the cosmetic treatment of DLE. Here, we report a case of a DLE scar that was successfully treated with a combination therapy of IPL and Q-switched 1,064-nm Nd:YAG laser.

Combined vitamin C sonophoresis and neodymium-doped yttrium aluminum garnet (NdYAG) laser for facial hyperpigmentation: An outcome observation study in Asian patients.

Background: The neodymium-doped yttrium aluminum garnet (NdYAG) laser therapy has been a popular technique for facial rejuvenation but certain adverse effects like post-infl ammatory hyperpigmentation are issues of concern to Asian patients. Aims: To assess the outcome following combined treatment with vitamin C sonophoresis and NdYAG laser, in selected cases of facial hyperpigmentation. Methods: Twenty three women with dyschromia or melasma who had undergone fi ve sessions of Q-switched NdYAG laser therapy followed by transdermal delivery of vitamin C via sonophoresis were selected after a retrospective review of case records. The objective and subjective clinical outcomes and the side effects, including erythema, scaling, pruritus, dryness and post-infl ammatory hyperpigmentation were evaluated. Results: In both objective or subjective outcomes, 91.3% (21/23) of the patients showed an excellent or better outcome, while 8.7% (2/23) showed no change. A majority of the patients (73.9%, 17/23) experienced no post-infl ammatory hyperpigmentation or had slight post-infl ammatory hyperpigmentation which quickly resolved within 1 week. Only one (4.3%) patient had extreme post-infl ammatory hyperpigmentation which lasted for over a month. Limitations: This was a retrospective study without a control group; a comparative study with a control group (patients treated with the laser alone, without vitamin C sonopheresis) is needed to determine the difference in the outcome. Conclusion: The use of vitamin C sonophoresis along with NdYAG laser may reduce the incidence of adverse effects in Asian patients. Patients experienced obvious improvement in hyperpigmentation and had lower chances of experiencing extreme or severe post-inflammatory hyperpigmentation.

Laser intervention on trabeculo‑Descemet’s membrane after resistant viscocanalostomy: Selective 532 nm gonioreconditioning or conventional 1064 nm neodymium‑doped yttrium aluminum garnet laser goniopuncture.

Purpose: To compare the results of conventional 1064 nm neodymium‑doped yttrium‑aluminum garnet laser goniopuncture (Nd:YAG‑GP) and selective 532 nm Nd:YAG laser (selective laser trabeculoplasty [SLT]) gonioreconditioning (GR) on trabeculo‑Descemet’s membrane in eyes resistant to viscocanalostomy surgery. Methods: Thirty‑eight eyes of 35 patients who underwent laser procedure after successful viscocanalostomy surgery were included in the study. When postoperative intraocular pressure (IOP) was above the individual target, the eyes were scheduled for laser procedure. Nineteen eyes underwent 532 nm SLT‑GR (Group 1), and the remaining 19 eyes underwent conventional 1064 nm Nd:YAG‑GP (Group 2). IOPs before and after laser (1 week, 1 month, 3 months, 6 months, 1 year, and last visit), follow‑up periods, number of glaucoma medications, and complications were recorded for both groups. Results: Mean times from surgery to laser procedures were 17.3 ± 9.6 months in Group 1 and 13.0 ± 11.4 months in Group 2. Mean IOPs before laser procedures were 21.2 ± 1.7 mmHg in Group 1 and 22.8 ± 1.9 mmHg in Group 2 (P = 0.454). Postlaser IOP measurements of Group 1 were 12.1 ± 3.4 mmHg and 13.8 ± 1.7 mmHg in the 1st week and last visit, respectively; in Group 2, these measurements were 13.6 ± 3.7 mmHg and 14.9 ± 4.8 mmHg, respectively. There were statistically significant differences (P < 0.001) in IOP reduction at all visits in both groups; the results of the two groups were similar (P > 0.05). Mean follow‑up was 16.6 ± 6.4 months after SLT‑GR and 18.9 ± 11.2 months after Nd:YAG‑GP. Conclusions: While conventional Nd:YAG‑GP and SLT‑GR, a novel procedure, are both effective choices in eyes resistant to viscocanalostomy, there are fewer complications with SLT‑GR. SLT‑GR can be an alternative to conventional Nd:YAG‑GP.

Prospective Comparison of Dual Wavelength Long-Pulsed 755-nm Alexandrite/1,064-nm Neodymium:Yttrium-Aluminum-Garnet Laser versus 585-nm Pulsed Dye Laser Treatment for Rosacea

BACKGROUND: Rosacea treatments including oral/topical medications and laser therapy are numerous but unsatisfactory. OBJECTIVE: To compare the effectiveness of the dual wavelength long-pulsed 755-nm alexandrite/1,064-nm neodymium: yttrium-aluminum-garnet laser (LPAN) with that of 585-nm pulsed dye laser (PDL) for rosacea. METHODS: This was a randomized, single-blinded, comparative study. Full face received four consecutive monthly treatments with LPAN or PDL, followed-up for 6 months after the last treatment. Erythema index was measured by spectrophotometer, and digital photographs were evaluated by consultant dermatologists for physician's global assessment. Subjective satisfaction surveys and adverse effects were recorded. RESULTS: Forty-nine subjects with rosacea enrolled and 12 dropped out. There were no significant differences between LPAN and PDL in the mean reduction of the erythema index (p=0.812; 3.6% vs. 2.8%), improvement of physician's global assessment (p=1.000; 88.9% vs. 89.5%), and subject-rated treatment satisfaction (p=0.842; 77.8% vs. 84.2%). PDL showed more adverse effects including vesicles than LPAN (p=0.046; 26.3% vs. 0.0%). No other serious or permanent adverse events were observed in both treatments. CONCLUSION: Both LPAN and PDL may be effective and safe treatments for rosacea.

Acquired Dermal Melanocytosis of the Nose Successfully Treated with Neodymium-doped Yttrium Aluminum Garnet 1064 nm Laser / 대한피부과학회지

No abstract available.

Underestimated risks of rare-earth magnet ingestion in children: when does it need surgery?

This review discusses an underestimated risk of rare-earthmagnet (henceforth, magnet) ingestion in children and its surgical indication. Due to the ubiquity of magnets, the incidence of magnet ingestion has rapidly increased. While most foreign body ingestions show spontaneous passage, multiple magnet ingestion requires surgery in 30%-70% of the cases. Multiple magnets can attract each other across the bowel wall, leading to pressure necrosis, and subsequently, fistula, perforation, obstruction or volvulus. After recognizing magnet ingestion, the number of magnets should be checked using radiographs. In case of multiple magnet ingestion, surgery should be promptly considered.