The lumbar intervertebral disc exhibits a complex physiological structure with interactions between various segments, and its components are extremely complex. The material properties of different components in the lumbar intervertebral disc, especially the water content (undergoing dynamic change as influenced by age, degeneration, mechanical loading, and proteoglycan content) - critically determine its mechanical properties. When the lumbar intervertebral disc is under continuous pressure, water seeps out, and after the pressure is removed, water re-infiltrates. This dynamic fluid exchange process directly affects the mechanical properties of the lumbar intervertebral disc, while previous isotropic modeling methods have been unable to accurately reflect such solid-liquid phase behaviors. To explore the load-bearing mechanism of the lumbar intervertebral disc and establish a more realistic mechanical model of the lumbar intervertebral disc, this study developed a solid-liquid biphasic, fiber-reinforced finite element model. This model was used to simulate the four movements of the human lumbar spine in daily life, namely flexion, extension, axial rotation, and lateral bending. The fluid pressure, effective solid stress, and liquid pressure-bearing ratio of the annulus fibrosus and nucleus pulposus of different lumbar intervertebral discs were compared and analyzed under the movements. Under all the movements, the fluid pressure distribution was closer to the nucleus pulposus, while the effective solid stress distribution was more concentrated in the outer annulus fibrosus. In terms of fluid pressure, the maximum fluid pressure of the lumbar intervertebral disc during lateral bending was 1.95 MPa, significantly higher than the maximum fluid pressure under other movements. Meanwhile, the maximum effective solid stress of the lumbar intervertebral disc during flexion was 2.43 MPa, markedly higher than the maximum effective solid stress under other movements. Overall, the liquid pressure-bearing ratio under axial rotation was smaller than that under other movements. Based on the solid-liquid biphasic modeling method, this study more accurately revealed the dominant role of the liquid phase in the daily load-bearing process of the lumbar intervertebral disc and the solid-phase mechanical mechanism of the annulus fibrosus load-bearing, and more effectively predicted the solid-liquid phase co-load-bearing mechanism of the lumbar intervertebral disc in daily life.
Humans ; Finite Element Analysis ; Intervertebral Disc/physiology* ; Lumbar Vertebrae/physiology* ; Weight-Bearing/physiology* ; Biomechanical Phenomena ; Stress, Mechanical ; Computer Simulation ; Models, Biological

Objective:To summarize the characteristics of autosomal recessive axonal neuropathy with neuromyotonia (ARAN-NM) caused by HINT1 gene mutation. Methods:Retrospective case summary.Clinical data of 2 Tibetan siblings diagnosed with ARAN-NM in the Department of Pediatrics of Peking University First Hospital in August 2023 were retrospectively analyzed.A review of literature reporting relevant Chinese patients was conducted.Results:The proband and her elder brother were aged 13 and 19, respectively.Both developed abnormal gait at the age of 11, followed by varus, claudication, and weak thumb strength.The proband also had neuromyotonia.Physical examinations showed that the proband and her elder brother had decreased muscle strength of the extremities, mainly in the thumbs and distal ends of lower limbs.The distal muscles of the proband′s lower extremities and the muscles of both hands of the proband′s elder brother were atrophied.Both feet showed talipes equinovarus in the proband and her elder brother.The proband′s electromyography (EMG) showed peripheral nerve injuries (motor and sensory axonal involvement, especially in distal ends) and myotonic potentials.The trio-whole exon sequencing detected homozygous pathogenic variation in HINT1 gene in both the proband and her elder brother, who were diagnosed as ARAN-NM based on c. 169A>G (p.K57E). After the Carbamazepine treatment, the proband′s neuromyotonia, numbness and weakness were relieved.Both the proband and her elder brother underwent orthopaedic surgery and rehabilitation.Their foot deformities and gait were significantly improved.Two Chinese literatures (2 patients) and four English literatures (8 patients) were retrieved.Including the proband and her elder brother in this study, there were 12 ARAN-NM patients, 10 of whom had clinical data.The ages of onset and diagnosis were 2-16 (1 case unknown) and 13-33 years old, respectively.Myasthenia was present in 9 patients, especially in distal ends.Eight patients were complicated with neuromyotonia, nine patients with muscle atrophy, seven patients with foot deformity, and two patients with sensory disturbance.Creatine kinase(CK) was elevated in all 9 patients tested or CK.EMG showed neurogenic injuries in all patients and neuromyotonia discharge in six patients.Three patients were treated with Carbamazepine, and some symptoms were relieved.Missense/nonsense mutations were found in the 12 patients, and the high-frequency variation was c. 112T>C (p.C38R). Conclusions:ARAN-NM is a rare autosomal recessive neuromuscular disease caused by HINT1 gene mutation.There is no ethnic difference in clinical manifestations, mainly distal limb weakness with neuromyotonia.Carbamazepine can alleviate some symptoms, and orthopaedic surgery can improve foot deformity and gait.

Objective:To study the clinical application and complications of umbilical arterial catheterization (UAC) in premature infants.Methods:From January 2021 to December 2022, premature infants with UAC successfully inserted in NICU of our hospital were enrolled. According to birth weight (BW), the infants were assigned into three groups: <1 000 g, 1 000~1 499 g and ≥1 500 g. The perinatal data, UAC usage, UAC-related complications and risk factors of UAC-related complications were retrospectively analyzed.Results:A total of 39 premature infants received UAC, with gestational age 29.3(27.3, 30.4) weeks and BW 1 100 (900, 1 310) g. The insertion length (IL) of UAC was calculated using the average value of two formulas: a, IL (cm) =4×BW (kg) +7; and b, IL(cm) =3×BW (kg)+9. The accuracy of tube end position was determined using chest/abdomen radiography. 30(76.9%) cases had accurate position, 6(15.4%) had higher position and 3(7.7%) had lower position. The proportion of appropriately positioned tube end in <1 000 g, 1 000~1 499 g and ≥1 500 g groups were 80.0%, 76.5% and 71.4%, respectively, without statistically significant differences ( P>0.05) .No significant differences existed among the three groups in UAC duration and UAC routinely removal rate ( P>0.05). 9 cases (23.1%) of UAC were removed for specific reasons, including 4 cases of arterial spasm, 2 cases of withdrawal of treatment, 1 case of tube end displacement, 1 case of abdominal distension and 1 case of death. 21 cases received 1 U/ml heparin (0.9%NaCl solution) 0.5~1 ml/h arterial infusion. 23.8% (5/21) had hypernatremia and the level of sodium became normal after reducing the concentration of NaCl solution. Arterial vasospasm occurred in 4 patients with skin color changes of one side of the lower extremities. After UAC removal, the skin color returned to normal. Conclusions:UAC is helpful and safe for preterm infants, however, its complications should be alerted to.

Objective:To discuss the point-selection and point-grouping patterns and therapeutic application features in acupuncture-moxibustion treatment of acute gouty arthritis(AGA)based on complex networks and to provide references for treating AGA with acupuncture-moxibustion therapy. Methods:Articles related to acupuncture-moxibustion treatment of AGA were searched across the China National Knowledge Infrastructure(CNKI),Chongqing VIP Database(CQVIP),Wanfang Data Knowledge Service Platform(Wanfang),Chinese Biomedical Literature Service System(SinoMed),PubMed,Web of Science(WOS),and Excerpta Medica Database(EMBASE)from their inception till March 31,2023.An acupuncture-moxibustion prescription database was established after the articles were screened according to the inclusion and exclusion criteria.The association rule and complex network analyses of points were conducted using SPSS Modeler 18.1 and Gephi 0.9.7. Results:A total of 145 articles were collected,contributing 382 pieces of acupuncture-moxibustion prescriptions involving 104 points with a total frequency of 1 288.Ashi points contributed the highest frequency.The Spleen Meridian of Foot-Taiyin and the Stomach Meridian of Foot-Yangming were more commonly selected.Filiform-needle acupuncture and bloodletting therapy were more frequently used.The association rule analysis revealed that the highest degree of support belonged to"Ashi point-Zusanli(ST36)"and"Sanyinjiao(SP6)-Zusanli(ST36)",which reflected the rules of point combination of distal and proximal areas and point combination of the coupled meridians.The complex network analysis of the major points discovered a core point prescription mainly consisting of Ahi point,Zusanli(ST36),Sanyinjiao(SP6),Yinlingquan(SP9),and Taichong(LR3).Pattern differentiation and region differentiation were used in selecting adjunct points,stressing the improvements of patterns and joint-related symptoms. Conclusion:Acupuncture-moxibustion treatment of AGA follows the principle of combining major points with adjunct points selected based on pattern or region differentiation;the selection of major points focuses on regulating the deficient Zang-Fu organs,and the selection of adjunct points emphasizes improving patterns and symptoms.The specificity of therapeutic effects is also stressed.

Objective:To investigate the efficacy and safety of recombinant tissue plasminogen activator (rt-PA) in patients with wake-up ischemic stroke (WUIS) of anterior circulation non-major arteries.Methods:Sixty-seven patients with WUIS of anterior circulation non-major arteries (time from falling asleep/last use of bathroom at night to intravenous thrombolysis≤9 h and >4.5 h) admitted to Department of Neurology, Beijing Shijingshan Hospital and Department of Neurosurgery, Beijing Muyangliu Hospital from January 1 st, 2017 to December 31 st, 2021 were chosen; these 35 patients accepted routine antiplatelet therapy after intravenous thrombolytic therapy were chosen as control group, and the other 32 patients accepted rt-PA arterial thrombolysis after intravenous thrombolytic therapy were chosen as study group. Vascular recanalization after arterial thrombolysis was observed in study group (cerebral infarction thrombolysis grading 2 and 3: good vascular recanalization). Neurological deficit improvement during treatment, clinical prognoses (modified Rankin scale scores of 0-2: good prognosis) and hemorrhagic transformation incidence 3 months after treatment were compared between the 2 groups. Results:The vascular thrombolytic recanalization rate of study group was 81.25% (26/32). Patients in study group had significantly decreased National Institute of Health stroke scale scores compared with those in control group 1, 7, and 14 d after thrombolytic therapy ( P<0.05). The good prognosis rate of study group (62.50%, 20/32) was significantly higher than that in control group (37.14%, 13/35, P<0.05). No significant difference in hemorrhagic transformation rate was noted between the 2 groups (15.6% [5/32] vs. 5.71% [2/35], P>0.05). Conclusion:Patients with WUIS of anterior circulation non-major arteries (time from falling asleep/last use of bathroom at night to intravenous thrombolysis≤9 h and >4.5 h) benefit from arterial thrombolysis with rt-PA, and risk of secondary intracerebral hemorrhage is not obviously increased.

Objective: To understand the level and risk factor of lead exposure among children in one city of Jiangsu. Methods: In northern Jiangsu Province, 373 children from 2 primary schools were enrolled and were tested for blood lead and heavy metal exposure. Lead exposure was tested in household dust of 46 children. A multivariate Logistic regression was used for lead exposure risk analysis. Spatial distribution of lead contamination in household dust was conducted and compared with the location of industrial enterprises. Results: The geometric mean of blood lead in 373 children was 25.80 mg/L,the blood lead of 3 children (0.8%) was more than 100 mg/L. Pencil biting ( OR=4.26, 95%CI=1.61-10.68, P <0.05) and lead contamination in surrounding environment ( OR=2.93, 95%CI=1.24-7.34, P =0.02) was positively related to high blood lead level in children. The geometric mean household dust lead concentrations in 46 children was 302.27 μg/mg, and household with high dust lead levels were mainly located around manufacturing enterprises. Conclusion Environmental factors correlate with blood lead level in children. Efficient strategies and public health policies are urgently needed to control and prevent environmental lead pollution. Families and schools should actively carry out health education to engourage children good hygiene habits, and effectively reduce lead exposure.

Objective:To investigate the incidence of hypothyroxinemia in very low birth weight infant (VLBWI) and its effect on early postnatal feeding and weight gain.Methods:This retrospective study analyzed 164 cases of VLBWIs admitted to the Neonatal Intensive Care Unit of Peking University First Hospital from January 2017 to December 2018. According to the gestational age, these VLBWIs were divided into <30 weeks group ( n=85) or ≥30 weeks group ( n=79), and the basic data and thyroid function were compared. According to the levels of serum tetraiodothyronine and free tetraiodothyronine at the first thyroid function test, the subjects were further assigned into normal thyroxine group and hypothyroxinemia group. The risk factors of hypothyroxinemia identified at the first detection were analyzed by single and multiple-facter analysis. The results of the second detection of thyroxine were also analyzed. On the basis of the first detection and receiving treatment or not, the <30 weeks and ≥30 weeks groups were divided into normal thyroxine, hypothyroxinemia treated and hypothyroxinemia untreated subgroups, and differences in the tolerance of early feeding and weight gain were compared between different groups. Two independent samples/paired t-test, rank sum test, Chi-square test and logistic regression were used for statistical analysis. Results:Out of the 164 VLBWIs with the gestational age of (29.7±2.0) weeks and birth weight of (1 210±210) g, 27 cases (16.5%) were extremely low birth weight infants. The age at their first detection was (10.7±3.1) d and the incidence of hypothyroxinemia was 45.1% (74/164), including 71 mild and three severe cases, with a higher incidence in the ≥30 weeks group comparing to the <30 weeks group [55.7%(44/79) vs 35.5%(30/85), χ 2= 6.883, P=0.009]. All the three severe cases were in the ≥30 weeks group. The gestational age ( OR=1.413, 95% CI:1.044-1.912, P=0.025) and male infant ( OR=2.082, 95% CI: 1.047-4.143, P=0.037) were the risk factors of hypothyroxinemia. At the second detection, the incidence of hypothyroxinemia in VLBWIs with normal thyroid function at their first test was 47.6% (39/82), which is higher in the ≥30 weeks group than in the <30 weeks group [64.5%(20/31) vs 37.3%(19/51), χ 2= 5.745, P=0.017]. Among the infants with hypothyroxinemia at the first detection, those untreated had a significantly higher incidence of hypothyroxinemia at the second detection than those treated [81.3%(26/32) vs 38.7%(12/31), χ 2= 11.905, P=0.001]. The incidence of abdominal distension within 21 days, feeding volume on day 7, 14, and 21, and neonatal weight gain within 7, 14, and 21 days were similar between normal thyroxine, hypothyroxinemia treated and hypothyroxinemia untreated subgroups within the ≥30 weeks or the <30 weeks groups (all P>0.05). Conclusions:VLBWI is at high risk of hypothyroxinemia. Two times of postnatal thyroid function tests can help to detect the delayed hypothyroxinemia. Thyroxine level and receiving treatment or not may have no significant effect on the early postnatal feeding and weight gain.

Objective To study the role of sequential cranial ultrasound (cUS) in the early prognosis of neurodevelopmental outcome in the very low birth weight and extremely low birth weight preterm infants.Method Clinical and examination data of premature infants with birth weight less than 1 500 g,who were admitted to the neonatal intensive care unit of our hospital within 24 hours after birth from January 2012 to December 2016 were analyzed retrospectively.Early cranial ultrasound refers to the cUS scans during the period of 0 to 14 days after birth.Classification was applied to the whole set of early cUS scans based on the most severe lesion observed.Index 1 was periventricular-intraventricular hemorrhage (PVH-IVH),which was divided into none and grade 1 to 4 according to the severity.Index 2 was paraventricular white matter echo,which was divided into normal,slightly enhanced and significantly enhanced.The cUS scan repeated at term-equivalent age (corrected gestational age 37 ～ 44 weeks) was referred to as term cUS.Term cUS was evaluated according to paraventricular leukomalacia (PVL) and enlargement of ventricle.Data were analyzed using IBM SPSS Statistics version 16.0.Result A total of 200 premature infants were collected.The gestational age was (30.1 ± 1.9) weeks,and the birth weight was (1 203 ± 186) g.The median time of cUS scans during hospitalization was 3 times.The age at which the Gesell Development Diagnosis Scale was completed was (11.8 ±4.0) months,the corrected age was (9.7 ±4.0) months.The development quotient (DQ) of gross motor was lower than that of the other four items,and the difference was statistically signi icant.Analysis of data suggested that PVH-IVH grade 3 or grade 4,significantly enhanced paraventricular white matter echo found in early cUS,and PVL or enlargement of ventricle found in term cUS were all associated to lower gross motor DQ (P ＜ 0.05).PVL was also significantly correlated with lower DQ of adaptability,fine motor,language and personal-social (P ＜ 0.05).Conclusion Compared to adaptability,fine motor,language and personal-social,gross motor has the lowest DQ among very low or extremely low birth weight infants.PVH-IVH grade 3 or worse,significantly enhanced paraventricular white matter echo found in early cUS,and PVL or enlargement of ventricle found in term cUS are high risk factors for adverse outcome of gross motor.Among them,PVL found in term cUS suggests poor neurodevelopmental outcome.

Objective To compare the short-term outcomes of less invasive surfactant administration (LISA) with traditional intubate-surfactant-extubate (INSURE) method for respiratory distress syndrome (RDS) in premature infants.Method From January 2017 to December 2018,premature infants (gestational age ≤32 weeks) diagnosed with RDS who needed pulmonary surfactant (PS) administration were prospectively enrolled and randomly assigned into LISA group and INSURE group.The duration of oxygen supply,side effects during PS administration,the outcome and severe adverse events,bronchopulmonary dysplasia (BPD),necrotizing enterocolitis (NEC),3 ～ 4° periventricular intraventricular hemorrhage (PIVH),periventricular leukomalacia (PVL) and death were compared.Result A total of 67 cases were enrolled including 34 in LISA group and 33 in INSURE group.No significant differences existed between the two group on mechanical ventilation rates,oxygen therapy duration and the incidences of severe adverse events.However,the duration of noninvasive ventilation in LISA group was significantly longer than INSURE group [(10.5 ± 8.7) d vs.(7.1 ± 2.6) d,P ＜ 0.05].The LISA group had significantly higher PS reflux rate than INSURE group [41.2％ (14/34)vs.18.2％ (6/33),P ＜0.05].Conclusion LISA has similar clinical effects and severe adverse events as INSURE,but with higher rates of PS reflux and longer duration of noninvasive ventilation.

Objective To investigate the predictive value of cervical length (CL) measured by transvaginal ultrasound for preterm birth<32 weeks,＜34 weeks in twin pregnancies in the second and the third trimester of pregnancy. Methods A total of 490 twin pregnant women with CL measured by transvaginal ultrasound during the second trimester of pregnancy (20-24 weeks) and the third trimester of pregnancy (28-32 weeks) delivered in Peking University Third Hospital, and Tongzhou Maternal and Child Health Hospital from January 2014 to December 2017 were collected, and 161 cases out of which were measured by CL during both the second trimester and the third trimester of pregnancy. Based on the measured gestational weeks, 427 cases were in the second trimester group and 224 cases in the third trimester group. The predictive value of CL for preterm birth was evaluated by calculating the optimal cut-off point with sensitivity and specificity. Logistic regression analysis was used to assess the relationship between CL and preterm birth after adjusting for confounding factors (age of pregnant women, chorionic status, mulipara, assisted reproductive pregnancy and pre-pregnancy body mass index). Results (1) The median CL of pregnant women in the second trimester group and the third trimester group were 36 mm (33-40 mm) and 28 mm (18-33 mm) respectively. In the second trimester group, 151 cases (35.4%, 151/427) were preterm birth and 276 cases (64.6%, 276/427) were full-term birth; the median CL of preterm and full-term pregnant women were 34 mm (30-37 mm) and 37 mm (34-40 mm), respectively, with significant difference (P<0.01). In the third trimester group, 100 cases (44.6%, 100/224) were preterm birth and 124 cases (55.4%, 124/224) were full-term birth; the median CL of preterm and full-term pregnant women were 22 mm (15-30 mm) and 31 mm (23-34 mm), respectively, with significant difference (P<0.01). (2) Prediction of preterm birth<32 weeks and<34 weeks was performed with CL in the second trimester group. The area under the receiver-operating characteristics curve were 0.78 (95% CI : 0.70-0.86) and 0.71 (95% CI : 0.64-0.79), respectively. The optimal cut-off points were 36.5 mm and 33.5 mm, respectively. After adjusting for confounding factors, CL was inversely associated with preterm birth<32 weeks and<34 weeks of gestation. (3) Prediction of preterm birth <32 weeks and <34 weeks were performed with CL in the third trimester group. The area under the receiver-operating characteristics curve were 0.86 (0.75-0.96) and 0.75 (0.67-0.84), respectively. The optimal cut-off points were 17.5 mm and 18.5 mm, respectively. After adjusting for confounding factors, CL was inversely associated with preterm birth at<32 weeks and<34 weeks of gestation. Conclusions CL measured by transvaginal ultrasound in the second and the third trimester is a good predictor for preterm birth of twin pregnancy. CL≤36.5 mm and≤33.5 mm at 20-24 weeks of gestation could predict preterm birth<32 weeks and<34 weeks respectively. CL≤17.5 mm and≤18.5 mm at 28-32 weeks of gestation could predict preterm birth<32 weeks and<34 weeks respectively.