A histological study of mouse tissues and water loss following lyophilization

Lyophilization is a practical method for product storage and transportation; it commonly is used in the food and pharmaceutical industries. Lyophilization also is used for preserving biological samples such as serum, plasma and animal tissues. We found that lyophilization does not affect the stability of RNAs and proteins in tissue samples. To investigate histological characteristics, we prepared lyophilized tissues for paraffin sectioning and hematoxylin and eosin (H & E) staining. We also measured water loss from organs during lyophilization. We used immunohistochemistry of frozen brain sections to identify potential protective effects of three concentrations of sucrose, glucose and trehalose against the effects of lyophilization. H & E staining revealed vacuoles in heart, lung, liver, kidney, spleen and brain after lyophilization without pretreatments, especially heart and kidney. We found that 10% solutions of sucrose, glucose and trehalose helped preserve tissue morphology. Immunohistochemistry of frozen brain tissue showed that 10% glucose and 30% sucrose preserved cellular characteristics and immunogenicity following lyophilization. Lyophilization removed > 70% of the water from organs, and lyophilized tissues without protectants were not suitable for histological study. Overall, we found that 10% glucose helped preserve both optimal tissue morphology and immunogenicity of freeze-dried tissue.

[Application of mucosal flap technique in Draf type Ⅱb/Ⅲ frontal sinus surgery]

Draf type Ⅱb/Ⅲ frontal sinus surgery has been widely used in clinical practice. They can obtain a wide operating space and sufficient drainage pathways. However, the mucosa around the frontal sinus ostium was removed during the surgery, resulting in bone exposure, and sinus ostium stenosis or atresia may occur after the operation. In recent years, rhinologists at home and abroad have applied various mucosal flaps to cover the exposed bone around the frontal sinus orifice after Draf Ⅱb/Ⅲ frontal sinus surgery, in order to reduce scar formation and bone hyperplasia along with the incidence of frontal sinus ostium stenosis or atresia after surgery. Satisfactory results have been achieved. The article reviews the application of mucosal flap technique in Draf Ⅱb/Ⅲ frontal sinus surgery, in order to promote the clinical research and technical development of this technique in China.

[Clinical characteristics, treatment and outcome of chronic mercury-related nephrotic syndrome]

Objective: To investigate the etiology, clinical features, treatment and outcome of nephrotic syndrome associated with chronic mercury poisoning. Methods: From June 2013 to April 2018, Beijing Chaoyang Hospital, Capital Medical University received 33 patients with chronic mercury-neutral nephrotic syndrome. The clinical manifestations, laboratory tests, treatment methods, and outcomes were analyzed. Results: Among the 33 patients, 27 patients had mercury exposure due to daily-life contact and the other 6 patients were caused by iatrogenic mercury. The symptom was characterized by typical nephrotic syndrome such as lower extremity edema and proteinuria at first onset. The treatment was based on mercury-removing treatment, 19 cases were treated with mercury removal alone, 16 cases were completely relieved; 10 cases were treated with mercury removal and glucocorticoids, all of which were completely relieved; 4 cases were treated with mercury removal, glucocorticoids and immunosuppressive agents, all complete remission; clinical complete remission rate is about 90.9% (30 cases in total) . Urinary mercury levels decreased the fastest between the first and second courses of mercury treatment, but the total amount of urine protein increased. As the amount of urinary mercury excreted increased, the total amount of urine protein decreased gradually (Z=2.86, P<0.01) . Conclusion: The clinical features of chronic mercury-induced nephrotic syndrome are non-specific, easy to be misdiagnosed and missed. The treatment is mainly treated with mercury removal treatment. The prognosis is good. In severe cases, glucocorticoid therapy can be supplemented.

[Study on the mechanism of serotype conversion of historical isolates of Shigella flexneri]

Objective: The serotype screening of Shigella flexneri from 1934 to 1965 preserved by the National Center for Medical Culture Collections was carried out, and the molecular characteristics of the serotype conversion strains were studied. Methods: Serotyping of Shigella flexneri in this study was conducted by slide agglutination and multiplex PCR, respectively. The gtrⅡ gene sequence alignment and pulsed field gel electrophoresis typing were performed on the serotype conversion strains. Results: Among the 255 strains of Shigella flexneri preserved in CMCC (B) from 1934 to 1965, 79 were carrying gtrⅡ gene, of which 19 strains and 1 strain were agglutinated with the Y serotype and X serotype, respectively, and furthermore, the multiplex PCR assays results showed serotypes 2a and 2b, respectively, and the strains were considered to have serotype conversion. The 20 strains carrying the gtrⅡ gene showed multiple nucleotide mutations. Besides 3 strains of 3 amino acid mutations, the amino acid sequences of the other 17 strains showed a stop codon in advance, resulting in functional inactivation of gtrⅡ. PFGE analysis revealed that the similarity between the serotype Y strain carrying the gtrⅡ gene and the serotype 2a strain was 75.8%-100%, and the similarity between the serotype X strain carrying the gtrⅡ gene and the serotype 2b strain was 81.6%-100%. Conclusion: Mutations in the gtrⅡ gene are more complicated in serotype-transforming Shigella flexneri serotype Y or X strains. Molecular typing suggests that the serotype-transforming Shigella flexneri serotype Y or X strains may be derived from the Shigella flexneri serotype 2a or 2b, and advance the serotype conversion to 1949.

[Nutritional status and energy metabolism characteristics in patients with nonalcoholic fatty liver disease]

Objective: To study the nutritional status and energy metabolic characteristics of patients with nonalcoholic fatty liver disease (NAFLD), and to provide evidence for clinical evaluation and intervention. Methods: A total of 359 NAFLD patients diagnosed on ultrasound from June 2015 to March 2017 were selected as study subjects and divided into mild, moderate to severe fatty liver disease group and 50 healthy subjects as control group. The changes of ICW, ECW, body fat, skeletal muscle, protein and visceral fat area (VFA) of patients and controls were analyzed by using body composition analyzer. The energy metabolism index was measured by the oxidation rate of resting energy expenditure(REE), respiratory quotient (RQ), and the oxidation rates of the three nutrients (CHO %, FAT %, and PRO %). According to different types of data, non-parametric tests like Kruskal-Wallis or χ(2) were used for this analysis. Results: Compared with the mild fatty liver group and the control group, the moderate and severe fatty liver group the BMI, waist circumference, waist-hip ratio were significantly elevated (P-value < 0.001), and their serum alanine aminotransferase, triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein, FBS levels were significantly increased (P value < 0.05). The Body composition analysis showed that there was no significant difference in skeletal muscle content between the three groups (P = 0.067). The ICW, ECW, protein, body fat content of moderate and severe fatty liver group were significantly higher than those of mild fatty liver group and control group (P < 0.01), but there was no significant difference between the mild fatty liver group and the control group. There was significant difference in the VFA between the three groups, while VFA in the moderate and severe fatty liver group was significantly increased. Metabolic results showed that the RQ of patients with moderate-severe fatty liver and mild fatty liver were 0.72 ± 0.08 and 0.78 ± 0.06, respectively, which were lower than those of the control group (0.80 ± 0.02), P = 0.004. Resting energy expenditure (REE) was not significantly different between moderate and severe fatty liver group and mild fatty liver group (P = 0.207), but both were significantly higher than those of the control group (P < 0.001). The percentages of CHO, FAT and PRO in moderate and severe fatty liver group were 19.49% ± 9.71%, 66.23% ± 12.54% and 14.22% ± 6.11% respectively. Compared with the control group, CHO % decreased, and FAT % increased. Conclusion: NAFLD patients have different extent of nutritional imbalance and energy metabolism disorders, the use of Body Composition analyzer and metabolic cart can comprehensively assess and monitor NAFLD patient's nutrition and energy metabolism status, to provide a basis for clinical intervention.

Antimicrobial effects of the ginsenoside Rh2 on monospecies and multispecies cariogenic biofilms

AIMS

To investigate the effects of the ginsenoside Rh2 on monospecies and multispecies cariogenic biofilms and explore the mechanism of the antibiofilm effect of Rh2 in vitro.

METHODS AND RESULTS

Streptococcus mutans, Streptococcus sobrinus and Streptococcus sanguinis were chosen to form the monospecies or multispecies biofilms. Crystal violet staining and laser scanning confocal microscopy were used to observe the effect of Rh2 on biofilms in vitro. Cytotoxicity was examined by the Cell Counting Kit-8. The effects of Rh2 on bacterial membranes were observed via transmission electron microscopy (TEM). The isobaric tags for relative and absolute quantification (iTRAQ) method were used to profile the common differentially expressed proteins. Gene expression was analysed by reverse transcription quantitative polymerase chain reaction. In general, the treatment of cariogenic biofilms with Rh2 significantly decreased biomass accumulation by inhibiting bacterial growth and extracellular polysaccharide synthesis without any cytotoxic effects. TEM imaging showed that Rh2 could disrupt the cell membranes of these bacteria. The iTRAQ results indicated that the levels of mannose-specific IIC/D and acetaldehyde/alcohol dehydrogenase were substantially down-regulated, while the mRNA expression of the corresponding genes were significantly changed.

CONCLUSIONS

Our data revealed a potential application for Rh2 in the protection against dental caries via the inhibition of cariogenic biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study describes the first application of a ginsenoside against multispecies cariogenic biofilms. Rh2 may serve as an alternative agent to prevent dental caries by effectively modulating the pathogenic potentials of oral biofilms.

Vascular and Biliary Complications Following Deceased Donor Liver Transplantation: A Meta-analysis

OBJECTIVE

To assess biliary and vascular complications after liver transplantations (LTs) sourced from deceased donors.

METHODS

This study reviewed potentially relevant English-language articles gathered from PubMed and Medline published from 2012 to 2017. One additional study was carried out using our institution's database for articles published from 2013 to 2017. Biliary and vascular complications from adult patients receiving their first deceased-donor LT were included. This meta-analysis was performed using Review Manager version 5.2 (Cochrane Collaboration, Copenhagen, Denmark) and the study quality was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Ten studies met our inclusion criteria. Heterogeneity in donation after cardiac death (DCD) and donation after brain death (DBD) recipients was observed and minimized after pooling a subgroup analysis. This latter analysis focused on biliary stricture, biliary leaks and stones, and vascular thrombosis and stenosis. Meta-analyses showed that patients receiving DCD organs have a greatly increased risk of biliary complications compared to those receiving DBD organs, particularly the following: biliary leaks and stones (odds ratio [OR] = 1.69, 95% confidence interval [CI] 1.22-2.34); and biliary stricture (OR = 1.58, 95% CI 1.21-2.06). DCD grafts tended to be but were not significantly associated with DBD regarding vascular thrombosis (OR = 1.62, 95% CI 1.05-2.50), and the risk of vascular stenosis in DCD grafts was not statistically significant (OR = 1.25, 95% CI, .70-2.25).

CONCLUSION

DCD was associated with an increased risk of biliary complications after LT, tended to indicate an increased risk of vascular thrombosis versus, and was not associated with an increased risk of vascular stenosis compared to DBD. There was no significant difference between the grafts.

Analysis of Genetic Polymorphism and Genetic Distance of 19 Autosomal STR Loci in Jiangsu Han Population

OBJECTIVES

To investigate the distribution of alleles in 19 autosomal short tandem repeat （STR） loci in Jiangsu Han population.

METHODS

Goldeneye^® 20A kit was used to detect 9 025 samples. Genetic analysis was performed on typing data of 19 autosomal STR loci, and genetic distance with other 17 populations was analyzed.

RESULTS

All the 19 autosomal STR loci were consistent with the Hardy-Weinberg equilibrium （P>0.05）, with the heterozygosity 0.616 1-0.916 3, probability of match 0.012 8-0.202 6, discrimination power 0.797 4-0.987 2, probability of paternity exclusion 0.310 8-0.828 8, and polymorphic information content 0.561 7-0.913 6. The cumulative discrimination power and cumulative probability of exclusion were 0.999 999 999 999 999 998 434 1 and 0.999 999 989, respectively. The Jiangsu Han population had close genetic distances with the Han population in Tianjin, Hunan and Jilin, and significant difference with Han population in Aletai region in Xinjiang （P<0.05）.

CONCLUSIONS

The STR allele polymorphism data and population genetic parameters of Jiangsu Han population can provide data support for the forensic application of these STR loci in Jiangsu Han population.

Mild Hypothermia Protects Renal Function in Ischemia-reperfusion Kidney: An Experimental Study in Mice

Mild hypothermia reduces the damage caused by hypoxia and oxidative stress, but how this happens is not very clear. Mice were anesthetized and their core body temperature was maintained at 38 ± 0.5°C and 32 ± 0.5°C. The renal artery and renal veins were blocked for 35 minutes and reperfusion was performed. Twenty-four hours later, serum was obtained to detect the concentrations of creatinine. The expression of CIRP, TRX, Bcl-2, and Bax were detected in tissue samples using Western blot. Apoptosis was measured using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and the apoptosis rates were calculated. SOD and MDA were detected to determine the extent of oxidative damage in different groups. The concentration of creatinine in the NC group was 2.11 ± 0.39 mg/dL. Compared to the IR group, the concentration of creatinine decreased in MH+IR group and showed a significant statistical difference (8.74 ± 1.38 mg/dL vs 15.36 ± 2.13 mg/dL, P < .01); the apoptosis rate also decreased with statistical significance (15.02 ± 1.45% vs 37.02 ± 5.70%, P < .01). Compared to the IR group, the expression of CIRP, TRX, and the Bcl-2/Bax ratio significantly increased in the MH+IR group. The SOD activity in the MH+IR group increased (26.90 ± 4.41 U/mgprot vs 16.85 ± 2.41 U/mgprot, P < .05) and the MDA level decreased (0.76 ± 0.18 nmol/mgprot vs 1.37 ± 0.32 nmol/mgprot, P < .05) compared to those of the IR group. Mild hypothermia protects mice kidneys from ischemia-reperfusion damage by reducing oxidative stress injury and apoptosis.

[The expression and significance of microtubule - driven protein KIF2A in epithelial ovarian cancer]

Objective: To investigate the protein and mRNA expression of KIF2A in ovarian cancer, and to investigate the migration and invasion ability changes in ovarian cancer cell line HO-8910 transfected by KIF2A-siRNA. Methods: Immunohistochemical method was used to detect the expression of KIF2A in 30 cases of ovarian cancer and 20 cases of ovarian normal tissues. The expression of KIF2A mRNA was detected by RT-PCR. The mRNA and protein expression of KIF2A in cell line HO-8910 was detected by RT-PCR and Western blot after transfected by KIF2A-siRNA in vitro. After the transfection, the cell migration and invasion ability were observed by scratch test and transwell experiments. Result: The expression of KIF2A mRNA and protein in HO-8910 was significantly lower than that in normal ovarian tissue (P<0.05). The capacities of migration and invasion of HO-8910 was suppressed notably after the knockdown of KIF2A (P<0.05). Conclusion: KIF2A gene expression was increased in ovarian cancer, and knockdown of KIF2A gene can inhibit the migration and invasion of ovarian cancer cells. It suggested that KIF2A gene may be a new target for the development of ovarian cancer.

Expression and clinical significance of miR-181a and miR-203 in systemic lupus erythematosus patients

OBJECTIVE

MiR-181a plays a critical role in modulating T cell and B cell differentiation, as well as immune response. Its abnormal expression probably participates in the pathogenesis of systemic lupus erythematosus (SLE). MiR-203 is involved in regulating Toll-like receptor and inducing immune tolerance. Abnormal expression or function of miR-203 is related to multiple auto-immune diseases but its role in SLE remains unclear. This study, thus, investigated the serum level of miR-181a and miR-203, to analyze their roles in diagnosing and evaluating SLE.

PATIENTS AND METHODS

SLE patients were recruited from our hospital, and divided into non-active and active SLE based on disease activity index, along with healthy individuals. qRT-PCR was used to quantify the serum miR-181a and miR-203 expression, and their correlation with clinical features. ROC was used to evaluate the diagnostic value on SLE, while survival curves were compared to show progression-free survival (PFS) between populations with high and low expression.

RESULTS

SLE patients had significantly higher serum levels of miR-181a and lower miR-203, both of which were correlated with SLE activity. Expression levels of miR-181a and miR-203 were correlated with erythrocyte sedimentation rate, C reactive protein, anti-dsDNA antibody, complements, and SLEDAI score. Their expression levels had certain values in the differential diagnosis for active SLE (AUC=0.885 and 0.843). PFS in miR-181a high-expression individuals was lower than that in the low-miR-181 group (χ2=7.474, p=0.029). Whilst, miR-203 high-expression SLE patients had higher PFS than low-expression group (χ2=4.367, p=0.037).

CONCLUSIONS

SLE patients had higher miR-181a and lower miR-203 expression, which thus may have critical implications in disease diagnosis and evaluation.

Childhood obesity prevention through a community-based cluster randomized controlled physical activity intervention among schools in china: the health legacy project of the 2nd world summer youth olympic Games (YOG-Obesity study)

Background:

Childhood obesity has been becoming a worldwide public health problem. We conducted a community-based physical activity (PA) intervention program aiming at childhood obesity prevention in general student population in Nanjing of China, the host city of the 2nd World Summer Youth Olympic Games (YOG-Obesity study).

Methods:

This was a cluster randomized controlled intervention study. Participants were the 4th (mean age±s.e.: 9.0±0.01) and 7th (mean age±s.e.: 12.0±0.01) grade students (mean age±s.e.: 10.5±0.02) from 48 schools and randomly allocated (1:1) to intervention or control groups at school level. Routine health education was provided to all schools, whereas the intervention schools additionally received an 1-year tailored multi-component PA intervention program, including classroom curricula, school environment support, family involvement and fun programs/events. The primary outcome measures were changes in body mass index, obesity occurrence and PA.

Results:

Overall, 9858 (97.7%) of the 10091 enrolled students completed the follow-up survey. Compared with the baseline, PA level increased by 33.13 min per week (s.e. 10.86) in the intervention group but decreased by 1.76 min per week (s.e. 11.53) in the control group (P=0.028). After adjustment for potential confounders, compared with the control group, the intervention group were more likely to have increased time of PA (adj. Odds ratio=1.15, 95% confidence interval=1.06–1.25), but had a smaller increase in mean body mass index (BMI) (0.22 (s.e. 0.02) vs 0.46 (0.02), P=0.01) and BMI z-score (0.07 (0.01) vs 0.16 (0.01), P=0.01), and were less likely to be obese (adj. Odds ratio=0.7, 95% confidence interval=0.6, 0.9) at study end. The intervention group had fewer new events of obesity/overweight but a larger proportion of formerly overweight/obese students having normal weight by study end.

Conclusions:

This large community-based PA intervention was feasible and effective in promoting PA and preventing obesity among the general student population in a large city in China. Experiences from this study are the lessons for China to control the childhood obesity epidemic.

[Diagnostic value of multi-slice spiral computerized tomographic fistulography in congenital fistula of neck]

Objective: To investigate the usefulness and effectiveness of multi-slice spiral computerized tomographic fistulography (MSCTF) in the diagnosis and treatment of congenital fistula of neck. Methods: Thirty-four patients with thyroglossal fistulasor branchial cleft fistulas who were initial treated from July 2008 to August 2015 in Fujian Provincial Hospital were retrospectively analyses. Thirteen males and 21 females patients aging from 3 to 46 years old with a median age of 37 were included. There were thyroglossal fistula in 6 cases, the first branchialcleft fistula in 9 cases, the second branchialcleft fistula in 3 cases, the third branchialcleft fistula in 9 cases, and the fourth branchialcleft fistula in 7 cases. All the patients underwent preopeative MSCTF and the diagnoses were finally confirmed with surgery and histopathology. Multiplanar reconstruction(MPR), maximumintensity projection(MIP)and volume rendering(VR) were completed with AW Volume Share 4.2 image processing software after initial CT scanning.The internal openings, distribution, and neighboring relationship of the fistulas showed by MSCTF were analyzed and the surgical strategies were subsequently made. Results: Except 2 cases, 32 patients had obtained successfully MSCTF image. The presence and location of the fistulas could be showed clearly on MSCTF. Based on the results of MSCTF examination, the surgical planes to treat the fistulas were made. The fistulas in all cases were successfully found and excised. Three cases underwent selective neck dissection. Postoperative infection occurred in 1 case. Unilateral vocal fold paralysis due to surgery recovered 3 months after surgery with follow-up. One case lost follow-up, the remaining 33 cases were followed up for 13-97 months with no the fistula recurrence. Conclusions: MSCTF could provide valuable information and benefit surgical planning by demonstrating the coursesof congenital fistulas of neck in detail.

Comparison of Clinical Outcomes Between Spousal and Living-related Donor Kidney Transplantation in Mainland China: A Single-center Experience

Shortage of donors still is the major obstacle for kidney transplantation. Living-related donors are the major resource of kidney transplantation at present. To expand the donor pool, spousal-donor kidney transplantation as one of the types of living-unrelated donors has been used to alleviate the organ shortage. A total of 116 living-kidney transplantations were retrospectively analyzed. We classified these recipients into two groups: a spousal-donor group (n = 50) and a living-related donor group (n = 66), and analyzed the outcome of transplantation. The Kaplan-Meier method was used for survival analysis with the log-rank test. The occurrence of delayed graft function and biopsy-proven acute rejection showed no significant difference between the two groups. Serum creatinine values at different times after transplantation in recipients with functioning grafts were similar in the two groups. Kaplan-Meier 3-year patient and graft survival rates were, respectively, 98% and 94% for the spousal donor group, and 98.5% and 95.5% for living-related donor group without significant difference. The demonstration of similar patient and graft survival of spousal-donor kidney transplantation compared with living-related donor kidney transplantation has made spousal-donor kidney transplantation an acceptable alternative for donor supply.

Nonlinear modulation of interacting between COMT and depression on brain function

BACKGROUND

The catechol-O-methyltransferase (COMT) gene is related to dopamine degradation and has been suggested to be involved in the pathogenesis of major depressive disorder (MDD). However, how this gene affects brain function properties in MDD is still unclear.

METHODS

Fifty patients with MDD and 35 cognitively normal participants underwent a resting-state functional magnetic resonance imaging scan. A voxelwise and data-drive global functional connectivity density (gFCD) analysis was used to investigate the main effects and the interactions of disease states and COMT rs4680 gene polymorphism on brain function.

RESULTS

We found significant group differences of the gFCD in bilateral fusiform area (FFA), post-central and pre-central cortex, left superior temporal gyrus (STG), rectal and superior temporal gyrus and right ventrolateral prefrontal cortex (vlPFC); abnormal gFCDs in left STG were positively correlated with severity of depression in MDD group. Significant disease×COMT interaction effects were found in the bilateral calcarine gyrus, right vlPFC, hippocampus and thalamus, and left SFG and FFA. Further post-hoc tests showed a nonlinear modulation effect of COMT on gFCD in the development of MDD. Interestingly, an inverted U-shaped modulation was found in the prefrontal cortex (control system) but U-shaped modulations were found in the hippocampus, thalamus and occipital cortex (processing system).

CONCLUSION

Our study demonstrated nonlinear modulation of the interaction between COMT and depression on brain function. These findings expand our understanding of the COMT effect underlying the pathophysiology of MDD.

Application value of laboratory indexes in the differential diagnosis of Henoch-Schoenlein purpura

OBJECTIVE

The aim of this study was to explore the value of laboratory indexes in the differential diagnosis of Henoch-Schoenlein purpura (HSP).

METHODS

Patients with HSP hospitalized at the Children's Hospital of Zhejiang University School of Medicine between January 2010 and December 2014 were enrolled in this prospective study. In addition, septic patients with rash and patients with urticaria, simple hematuria, and acute appendicitis hospitalized during the same period were selected at random as differential diagnosis subjects, and healthy children were selected as normal controls. The levels of IgA, D‑dimer, fibrinogen (FIB), and platelet (PLT) and the platelet distribution width (PDW) of these individuals were tested and analyzed, and the ROC curve was used to determine the applicability of these indexes to differentiate between patients with HSP and other diseases easily confused with HSP, as well as to determine the efficacy of combined diagnosis.

RESULTS

There were remarkable differences in the levels of FIB, D‑dimer, IgA, PLT, and PDW among patients with HSP, sepsis patients with rash, patients with urticaria, simple hematuria, or acute appendicitis and healthy children (P < 0.01).

CONCLUSION

The levels of IgA, D‑dimer, and PLT can be applied separately for the differential diagnosis of HSP, and these indexes and FIB can be combined appropriately to improve the diagnostic efficacy.

The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion

Objectives

Many studies have investigated the kinematics of the lumbar spine and the morphological features of the lumbar discs. However, the segment-dependent immediate changes of the lumbar intervertebral space height during flexion-extension motion are still unclear. This study examined the changes of intervertebral space height during flexion-extension motion of lumbar specimens.

Methods

First, we validated the accuracy and repeatability of a custom-made mechanical loading equipment set-up. Eight lumbar specimens underwent CT scanning in flexion, neural, and extension positions by using the equipment set-up. The changes in the disc height and distance between adjacent two pedicle screw entry points (DASEP) of the posterior approach at different lumbar levels (L3/4, L4/5 and L5/S1) were examined on three-dimensional lumbar models, which were reconstructed from the CT images.

Results

All the vertebral motion segments (L3/4, L4/5 and L5/S1) had greater changes in disc height and DASEP from neutral to flexion than from neutral to extension. The change in anterior disc height gradually increased from upper to lower levels, from neutral to flexion. The changes in anterior and posterior disc heights were similar at the L4/5 level from neutral to extension, but the changes in anterior disc height were significantly greater than those in posterior disc height at the L3/4 and L5/S1 levels, from neutral to extension.

Conclusions

The lumbar motion segment showed level-specific changes in disc height and DASEP. The data may be helpful in understanding the physiologic dynamic characteristics of the lumbar spine and in optimising the parameters of lumbar surgical instruments.

Cite this article: M. Fu, Q. Ye, C. Jiang, L. Qian, D. Xu, Y. Wang, P. Sun, J. Ouyang. The segment-dependent changes in lumbar intervertebral space height during flexion-extension motion. Bone Joint Res 2017;6:245–252. DOI: 10.1302/2046-3758.64.BJR-2016-0245.R1.