OBJECTIVE: To investigate the accuracy and safety of pedicle screw placement using 3D-printed auxiliary guides in scoliosis correction surgery for adolescents. METHODS: A retrospective analysis was conducted on the clinical data of 51 patients who underwent posterior scoliosis correction surgery from January 2020 to March 2023. Among them, there were 35 cases of adolescent idiopathic scoliosis and 16 cases of congenital scoliosis. The patients were divided into two groups based on the auxiliary tool used:the 3D-printed auxiliary guide screw placement group (3D printing group) and the free-hand screw placement group (free-hand group, without auxiliary tools). The 3D printing group included 32 patients (12 males and 20 females) with an average age of (12.59±2.60) years;the free-hand group included 19 patients (7 males and 12 females) with an average age of (14.58±3.53) years. The two groups were compared in terms of screw placement accuracy and safety, spinal correction rate, intraoperative blood loss, number of intraoperative fluoroscopies, operation time, hospital stay, and preoperative and last follow-up scores of the Scoliosis Research Society-22 (SRS-22) questionnaire. RESULTS: A total of 707 pedicle screws were placed in the two groups, with 441 screws in the 3D printing group and 266 screws in the free-hand group. All patients in both groups successfully completed the surgery. There was a statistically significant difference in operation time between the two groups (P<0.05). The screw placement accuracy rate of the 3D printing group was 95.46% (421/441), among which the Grade A placement rate was 89.34% (394/441);the screw placement accuracy rate of the free-hand group was 86.47% (230/266), with a Grade A placement rate of 73.31% (195/266). There were statistically significant differences in the accuracy of Grade A, B, and C screw placements between the two groups (P<0.05), while no statistically significant differences were observed in intraoperative blood loss, number of fluoroscopies, correction rate, or hospital stay (P>0.05). In the SRS-22 questionnaire scores, the scores of functional status and activity ability, self-image, mental status, and pain of patients in each group at the last follow-up were significantly improved compared with those before surgery (P<0.05), but there were no statistically significant differences in all scores between the two groups (P>0.05). CONCLUSION In scoliosis correction surgery, compared with traditional free-hand screw placement, the use of 3D-printed auxiliary guides for screw placement significantly improves the accuracy and safety of screw placement and shortens the operation time.
Humans ; Male ; Scoliosis/surgery* ; Female ; Adolescent ; Printing, Three-Dimensional ; Retrospective Studies ; Pedicle Screws ; Child

Although teniposide(VM26)is widely used in the treatment of lymphoma,its poor water sol-ubility,low bioavailability and systemic toxicities still limit its clinical application.Nano-delivery systems are effective in increasing the bioavailability and reducing the toxicity of VM26,but there is an urgent need to overcome the problem of its non-specific targeting.Therefore,in this paper,we designed and constructed a hyaluronic acid-modified teniposide-targeted nano-delivery system(VM26-TNDS),and characterised its drug encapsulation rate,particle size and zeta potential.We also investigated the effects of VM26-TNDS on B-cell lymphoma cells with different expression of CD44 receptor,in terms of cellular targeting,inhibitory effect of proliferation,and induction of apoptosis and necrosis.The results showed that the drug encapsulation efficiency of VM26-TNDS exceeded 85％,and its liquid formulation could be stably stored at 4 ℃ for more than 6 months without precipitation.Based on CD44 receptor expression,Granta-519(high expression),Raji(medium-low expression)and SU-DHL-4(almost no expression)were screened for cellular experiments.Compared with VM26-NDS,the targeted modification could effec-tively reduce the uptake of VM26-TNDS by RAW264.7 and increase the uptake of VM26-TNDS by CD44 receptor-expressing lymphoma cells.The inhibitory proliferative effect and apoptotic necrosis-inducing a-bility of VM26-TNDS were stronger than those of VM26-NDS for Granta-519 and Raji cells,whereas there was no significant difference in the inhibitory effect on proliferation and ability to induce apoptosis and necrosis between VM26-NDS and VM26-TNDS in SU-DHL-4 cells,reflecting the targeting advantage for VM26-TNDS,as expected.However,its toxic effect on B-cell lymphoma cells only reflected the targeting advantage at some concentrations(0.25 μmol/L and 0.5 μmol/L),which met the expectation.The a-bove results indicate that a teniposide-targeted nano-delivery system,VM26-TNDS,has been successfully prepared in this study.VM26-TNDS improves the delivery efficiency of VM26 by targeting human B-cell lymphoma cells expressing the CD44 receptor,thus killing human B-cell lymphoma cells more effectively and overcoming the problem of non-specific targeting in drug delivery to improve the therapeutic effect.Its biological therapeutic effects and mechanisms still need to be proved by more in vitro and in vivo ex-perimental evidence.

Calvarial stem cells are essential for maintaining the health and function of the craniofacial complex and the central nervous system.Under physiological conditions,these stem cells primarily reside within specialized microenvironments known as stem cell niches,located in the bone marrow,periosteum,and sutures of cranial bones.The heterogeneous cellular populations within the microenvironment dynamically regulate the quantity and function of stem cells.Due to their distinct spatial distribution,these stem cells exhibit unique functional characteristics and play crucial roles in the development and progression of various diseases,as well as in relevant therapeutic applications.Herein,we summarize the latest research advances concerning various types of calvarial stem cells,elaborating on their respective functions,microenvironmental regulation,and therapeutic potential,thereby providing new perspectives for both basic research and clinical applications in this field.

Objective:To compare the medical costs of using standard fortified donor human milk (DHM) or preterm formula (PF) to supply very low birth weight [VLBW, defined as birth weight (BW) ≥1 000 g but <1 500 g] and extremely low birth weight (ELBW, defined as BW <1 000 g) premature infants with insufficient maternal breast milk.Methods:VLBW and ELBW preterm infants hospitalized in Peking Union Medical College Hospital from September 2017 to October 2020 were retrospectively enrolled and assigned into DHM group and PF group based on complementary feeding methods. The cost of parenteral nutrition (PN), cost of antibiotics, and total medical expenses during hospitalization were compared between the two groups.Results:A total of 89 infants were enrolled in this study, out of whom 50 was in the DHM group and 39 the PF group. The gestational age in DHM group and PF group were both (29±2) weeks. The BW of DHM group was 1 170 (919, 1 380)?g and that of PF group was 1 170 (1 010, 1 360) g. There were no significant differences in gestational age, BW, maternal age at delivery, delivery mode, gender ratio, proportion of small-for-gestational-age infants and length of hospital stay between the two groups (all P>0.05). The cost of parenteral nutrition in DHM group was significantly lower than that in PF group [3 500 (1 922, 5 704) Chinese yuan vs 7 995 (5 579, 10 788) Chinese Yuan, P<0.01]. The cost of antibiotics in DHM group was significantly lower than that in PF group [6 529 (2 265, 10 860) Chinese Yuan vs 13 676 (10 480, 18 506) Chinese Yuan, P<0.01]. The difference in total medical expense during hospitalization showed no statistical significance between two groups ( P>0.05). Amorg VLBW preterm infants, the cost of PN, cost of antibiotics, total cost of hospitalization, and daily cost of hospitalization in HDM group was significantly lower than that in PF group (all P<0.05). In ELBW preterm infants, the cost of PN and the cost of antibiotics in HDM group were significantly lower than that in PF group (both P<0.05), but the total cost of hospitalization and the daily cost of hospitalization between two groups showed no significant difference (all P>0.05). Conclusions:When mother's own milk is insufficient, using donor human milk reduces the costs of PN and antibiotics in VLBW and ELBW preterm infants compared with using PF. In VLBW preterm infants, using DHM can also reduce the total and daily cost of hospitalization.

Objective:To compare the medical costs of using standard fortified donor human milk (DHM) or preterm formula (PF) to supply very low birth weight [VLBW, defined as birth weight (BW) ≥1 000 g but <1 500 g] and extremely low birth weight (ELBW, defined as BW <1 000 g) premature infants with insufficient maternal breast milk.Methods:VLBW and ELBW preterm infants hospitalized in Peking Union Medical College Hospital from September 2017 to October 2020 were retrospectively enrolled and assigned into DHM group and PF group based on complementary feeding methods. The cost of parenteral nutrition (PN), cost of antibiotics, and total medical expenses during hospitalization were compared between the two groups.Results:A total of 89 infants were enrolled in this study, out of whom 50 was in the DHM group and 39 the PF group. The gestational age in DHM group and PF group were both (29±2) weeks. The BW of DHM group was 1 170 (919, 1 380)?g and that of PF group was 1 170 (1 010, 1 360) g. There were no significant differences in gestational age, BW, maternal age at delivery, delivery mode, gender ratio, proportion of small-for-gestational-age infants and length of hospital stay between the two groups (all P>0.05). The cost of parenteral nutrition in DHM group was significantly lower than that in PF group [3 500 (1 922, 5 704) Chinese yuan vs 7 995 (5 579, 10 788) Chinese Yuan, P<0.01]. The cost of antibiotics in DHM group was significantly lower than that in PF group [6 529 (2 265, 10 860) Chinese Yuan vs 13 676 (10 480, 18 506) Chinese Yuan, P<0.01]. The difference in total medical expense during hospitalization showed no statistical significance between two groups ( P>0.05). Amorg VLBW preterm infants, the cost of PN, cost of antibiotics, total cost of hospitalization, and daily cost of hospitalization in HDM group was significantly lower than that in PF group (all P<0.05). In ELBW preterm infants, the cost of PN and the cost of antibiotics in HDM group were significantly lower than that in PF group (both P<0.05), but the total cost of hospitalization and the daily cost of hospitalization between two groups showed no significant difference (all P>0.05). Conclusions:When mother's own milk is insufficient, using donor human milk reduces the costs of PN and antibiotics in VLBW and ELBW preterm infants compared with using PF. In VLBW preterm infants, using DHM can also reduce the total and daily cost of hospitalization.

Although teniposide(VM26)is widely used in the treatment of lymphoma,its poor water sol-ubility,low bioavailability and systemic toxicities still limit its clinical application.Nano-delivery systems are effective in increasing the bioavailability and reducing the toxicity of VM26,but there is an urgent need to overcome the problem of its non-specific targeting.Therefore,in this paper,we designed and constructed a hyaluronic acid-modified teniposide-targeted nano-delivery system(VM26-TNDS),and characterised its drug encapsulation rate,particle size and zeta potential.We also investigated the effects of VM26-TNDS on B-cell lymphoma cells with different expression of CD44 receptor,in terms of cellular targeting,inhibitory effect of proliferation,and induction of apoptosis and necrosis.The results showed that the drug encapsulation efficiency of VM26-TNDS exceeded 85％,and its liquid formulation could be stably stored at 4 ℃ for more than 6 months without precipitation.Based on CD44 receptor expression,Granta-519(high expression),Raji(medium-low expression)and SU-DHL-4(almost no expression)were screened for cellular experiments.Compared with VM26-NDS,the targeted modification could effec-tively reduce the uptake of VM26-TNDS by RAW264.7 and increase the uptake of VM26-TNDS by CD44 receptor-expressing lymphoma cells.The inhibitory proliferative effect and apoptotic necrosis-inducing a-bility of VM26-TNDS were stronger than those of VM26-NDS for Granta-519 and Raji cells,whereas there was no significant difference in the inhibitory effect on proliferation and ability to induce apoptosis and necrosis between VM26-NDS and VM26-TNDS in SU-DHL-4 cells,reflecting the targeting advantage for VM26-TNDS,as expected.However,its toxic effect on B-cell lymphoma cells only reflected the targeting advantage at some concentrations(0.25 μmol/L and 0.5 μmol/L),which met the expectation.The a-bove results indicate that a teniposide-targeted nano-delivery system,VM26-TNDS,has been successfully prepared in this study.VM26-TNDS improves the delivery efficiency of VM26 by targeting human B-cell lymphoma cells expressing the CD44 receptor,thus killing human B-cell lymphoma cells more effectively and overcoming the problem of non-specific targeting in drug delivery to improve the therapeutic effect.Its biological therapeutic effects and mechanisms still need to be proved by more in vitro and in vivo ex-perimental evidence.

Objective:To compare the short-term outcomes of very low birth weight (VLBW) and extremely low birth weight (ELBW) infants supplementarily fed with fortified donor human milk (DHM) or preterm formula (PF) when the mother's own milk (MOM) is insufficient.Methods:This retrospective cohort study included 91 VLBW or ELBW preterm infants with birth weight<1 500 g who were hospitalized in Peking Union Medical College Hospital from October 1, 2017, to September 30, 2020. Based on the supplemental feeding method when MOM was insufficient, these infants were divided into the DHM group ( n=51) and PF group ( n=40). Mann-Whitney U, t-test, Chi-square test, or Fisher's exact test were used to compare the short-term clinical outcomes during hospitalization between the two groups. Results:(1) There were no statistically significant differences between the 91 preterm infants in the DHM group and PF group in their gestational age, birth weight, sex ratio, birth mode, mothers' age at delivery, or the proportion of infants of small gestational age (all P>0.05). (2) The feeding volume in the DHM group was significantly greater than that in the PF group on the 14th day after birth [(108.2±53.1) vs. (81.0±47.8) ml/(kg·d), t=0.78, P=0.020]. Moreover, the time to achieve the feeding amounts up to 120 ml/(kg·d) and 150 ml/(kg·d) for infants in the DHM group were significantly shorter than those in the PF group [(17.5±10.2) vs. (30.0±12.0) d, t=4.38; (22.1±13.3) vs. (32.3±11.9) d, t=0.02; both P<0.05]; (3) Lower proportion of peripherally inserted central catheter (PICC) [58.8% (30/51) vs. 100% (40/40), χ 2=21.88, P<0.001] and shorter PICC duration were observed in the DHM group [10.0 (0.0-19.0) vs. 29.0 (17.0-40.5) d, Z=5.56, P<0.001] compared to the PF group. The times of red blood cell transfusions and the incidence of late sepsis in the DHM group were less than those in the PF group [0.0 (0.0-2.0) vs. 2.0 (1.0-3.0) times, Z=4.44, P<0.001; 23.5% (12/51) vs. 50.0% (20/40), χ 2=6.39, P=0.011]. There were no statistically significant differences observed in the incidence of bronchopulmonary dysplasia, neonatal necrotizing enterocolitis, retinopathy of prematurity, and the length of hospitalization (all P>0.05). Conclusion:When MOM is insufficient, supplementing VLBW and ELBW infants with fortified donor human milk can shorten the time to achieve enteral nutrition and reduce the use rate and time of PICC, the incidence of late-onset sepsis, and the times of red blood cell transfusion.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

Objective:To investigate the effect of selenium on cyclophosphamide(CTX)-induced spermatogenic impairment(SI)in mice and its underlying mechanism.Methods:We equally randomized 36 male KM mice into 3 SI model and 3 control groups,the first 3 treated by intraperitoneal injection of CTX at 100 mg/kg(the SI model control group),CTX plus SI model control group,selenium deficient model group(-Se SI),selenium supplemented model group(+Se SI),while latter 3 by intraperitoneal injection of normal saline(the normal control),selenium deficiency control group(-Se control),selenium addition control group(+Se control),respectively,all once a week for 6 successive weeks.Then we observed the histopathological changes in the testes of all the mice by HE staining,obtained the sperm count in the epididymides,determined the expressions of glutathione peroxidase 4(GPx4)and SLC7A11 proteins by Western blot and ferroptosis-related genes by RT-qPCR,and examined the changes in the expres-sions of ferroptosis-related proteins and genes in the GC2-spd cells treated with ferroptosis inhibitors and inducers in combination with different concentrations of inorganic sodium selenite(SeS)and organic selenomethionine(SeM).Results:Compared with the nor-mal controls,the SI model mice showed significantly decreased testicular and prostatic organ coefficients,reduced spermatogenic lay-ers,increased voids,decreased serum ferritin concentration(P<0.05),and elevated transferrin concentration(P<0.05).The or-gan coefficients were significantly higher in the+Se SI and+Se control than in the-Se SI and-Se control groups(P<0.05,P<0.01),with evident pathological improvement of the testis tissue in the+Se controls.The expressions of the GPx4 and solute carrier family 7 members 11(SLC7A11)genes in the testis were dramatically down-regulated in the SI model controls(P<0.01),but up-reg-ulated in the+Se SI and+Se control compared with those in the-Se SI and-Se control group(P<0.01 and P<0.05),but there were no statistically significant differences between their protein expressions.The results of in vitro GC2 spd cell experiments indicated that the GPx4 gene and GPx4 protein levels in the-Se group were significantly lower than those in the normal control group(P<0.05),while the SLC7A11 gene level decreased(P<0.01).Different doses of SeS and SeM significantly increased the GPx4 protein expression compared to the average Se group.Low doses of SeM promoted a significant increase in GPx4 gene levels,while high doses of SeS increased the expression levels of SLC7A11 gene and SLC7A11 protein(P<0.05,P<0.01).The Se group showed a signifi-cant decrease in the levels of acsl4 and ptgs2 genes compared to the normal control group.SeM promoted the expression of acsl4,while SeS promoted the expression of ptgs2 and fth1(P<0.01,P<0.05).The intervention results of GC2 spd showed that the Erastin group had a decrease in ptgs2 compared to the normal control group,while the SeS+Erastin and SeM+Erastin groups had an increase in ptgs2 gene expression compared to the Erastin group.However,the ptgs2 expression of Fer-1 was lower than that of the normal con-trol group,and the ptgs2 gene level of SeS+Fer-1 and SeM+Fer-1 groups was lower than that of Fer-1 group(P<0.05);The gene quantity of GPx4 in the SeM+Erastin and SeM+Fer-1 groups increased compared to the Erastin and Fer-1 groups(P<0.01,P<0.05);SeM+Erastin and SeS+Erastin showed a decrease in SLC7A11 compared to the Erastin group,as well as SeM+Fer-1 and SeS+Fer-1 groups compared to the Fer-1 group,accompanied by an increase in acsl4 and fth1(P<0.01).Conclusion:Selenium deficiency causes the reduction of the SLC7A11 and GPx4 gene levels,disorder of ferroptosis-related genes and down-regulation of the GPx4 protein expression in the mouse testis and spermatocytes.Selenium can promote the expression of GPx4,up-regulate the level of SLC7A11,and improve spermatogenesis in the testis of the mouse with SI.There are differences between organic SeM and inorganic SeS in regulating the ferroptosis pathway-related genes.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]