[Objective] To study the molecular biological mechanism for a case of ABO blood group B subtype, and perform three-dimensional modeling of the mutant enzyme. [Methods] The ABO phenotype was identified by the tube method and microcolumn gel method; the ABO gene of the proband was detected by sequence-specific primer polymerase chain reaction (PCR-SSP), and the exon 6 and 7 of the ABO gene were sequenced and analyzed. Homologous modeling of Bw.03 glycosyltransferase (GT) was carried out by Modeller and analyzed by PyMOL2.5.0 software. [Results] The weakening B antigen was detected in the proband sample by forward typing, and anti-B antibody was detected by reverse typing. PCR-SSP detection showed B, O gene, and the sequencing results showed c.721 C>T mutation in exon 7 of the B gene, resulting in p. Arg 241 Trp. Compared with the wild type, the structure of Bw.03GT was partially changed, and the intermolecular force analysis showed that the original three hydrogen bonds at 241 position disappeared. [Conclusion] Blood group molecular biology examination is helpful for the accurate identification of ambiguous blood group. Homologous modeling more intuitively shows the key site for the weakening of Bw.03 GT activity. The intermolecular force analysis can explain the root cause of enzyme activity weakening.

BACKGROUND:Traditional surgery for lumbar disc herniation involves extensive excision of tissue surrounding the nerve for decompression and removal of protruding lumbar intervertebral discs,which poses various risks and complications such as nerve damage causing paralysis,lumbar instability,herniation recurrence,intervertebral space infection,and adjacent vertebral diseases. OBJECTIVE:To propose the symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous technique for lumbar spine symmetrically decompression,showing the induced resorption of herniated nucleus pulpous phenomenon and early clinical efficacy,and then analyze its decompression mechanism. METHODS:214 patients with lumbar disc herniation at Department of Orthopedics,First Affiliated Hospital of Zhengzhou University from March 2021 to May 2023 were enrolled in this study.Among them,81 patients received conservative treatment as the control group,and 133 patients received symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous treatment as the trial group.Before surgery,immediately after surgery(7-14 days),and early after surgery(over 1 year),MRI images were used to measure the volume changes of lumbar disc herniation.CT images were used to measure the posterior displacement distance of the lumbar spinous process ligament complex,as well as the width and height of the lateral recess.Japanese Orthopaedic Association scores were used to evaluate the patient's neurological function recovery. RESULTS AND CONCLUSION:(1)Control group:81 patients with lumbar disc herniation were treated conservatively,with a total of 171 herniated lumbar discs.The average follow-up time was(22.7±23.1)months.The first and second MRI measurements of 171 herniated lumbar discs showed herniated lumbar disc volumes of(551.6±257.9)mm3 and(792.2±330.4)mm3,respectively,with an average volume increase rate of(53.2±44.4)%,showing statistically significant differences(P<0.001).Out of 171 herniated lumbar discs,4 experienced natural shrinkage,with an absorption ratio of 2.3%(4/171)and an absorption rate of(24.5±9.9)%.(2)Trial group:133 patients with lumbar disc herniation had a total of 285 herniated lumbar discs.(1)Immediately after surgery:All patients were followed up immediately after surgery.229 out of 285 herniated lumbar discs experienced retraction,with an absorption ratio of 80.3%(229/285)and an average absorption rate of(21.5±20.9)%,with significant and complete absorption accounting for 6.5%.There were a total of 70 herniated lumbar discs in the upper lumbar spine,with an absorption ratio of 85.7%(60/70),an average absorption rate of(23.1±19.5)%,and a maximum absorption rate of 86.6%.There were 215 herniated lumbar discs in the lower lumbar spine,with an absorption ratio of 78.6%(169/215),an average absorption rate of(21.0±21.3)%,and a maximum absorption rate of 83.2%.Significant and complete absorption of the upper and lower lumbar vertebrae accounted for 5.7%and 6.5%,respectively,with no statistically significant difference(P>0.05).The average distance of posterior displacement of the spinous process ligament complex immediately after surgery was(5.2±2.8)mm.There were no significant differences in the width and height of the left and right lateral recess before and immediately after surgery(P>0.05).The Japanese Orthopaedic Association score immediately after surgery increased from(10.1±3.4)before surgery to(17.0±4.8),and the immediate effective rate after surgery reached 95.6%.(2)Early postoperative period:Among them,46 patients completed the early postoperative follow-up.There were 101 herniated lumbar discs,with an absorption ratio of 94%(95/101)and an average absorption rate of(36.9±23.7)%.Significant and complete absorption accounted for 30.6%,with a maximum absorption rate of 100%.Out of 101 herniated lumbar discs,3 remained unchanged in volume,with a volume invariance rate of 2.97%(3/101).Out of 101 herniated lumbar discs,3 had an increased volume of herniated lumbar discs,with an increase ratio of 2.97%(3/101)and an increase rate of(18.5±18.4)%.The Japanese Orthopaedic Association score increased from preoperative(9.3±5.1)to(23.5±4.0),with an excellent and good rate of 93.4%.(3)The early postoperative lumbar disc herniation absorption ratios of the control group and trial group were 2.3%and 85.9%,respectively,with statistically significant differences(P<0.001).(4)Complications:There were two cases of incision exudation and delayed healing in the trial group.After conservative treatment such as dressing change,no nerve injury or death occurred in the incision healing,and no cases underwent a second surgery.(5)It is concluded that symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous is a new method for treating lumbar disc herniation that can avoid extensive excision of the"ring"nerve and achieve satisfactory early clinical efficacy.It does not damage the lumbar facet joints or alter the basic anatomical structure of the lateral recess,fully preserves the herniated lumbar discs,and can induce significant or even complete induced resorption of herniated nucleus pulpous.Symmetrically adduction of lumbar decompression induced resorption of herniated nucleus pulpous provides a new basis and method for the clinical treatment of lumbar disc herniation.

BACKGROUND:Mechanical stimulation has been confirmed to promote osteogenic differentiation of bone marrow stromal stem cells,but the mechanism is unknown.Primary cilia are important mechanoreceptors and regulate various signaling pathways such as TGF-β1/BMP-2/SMAD.They are likely to be important targets for mechanical regulation of bone marrow stromal stem cells. OBJECTIVE:To investigate the effect and mechanism of fluid shear stress on osteogenic differentiation of bone marrow stromal stem cells. METHODS:Rat bone marrow stromal stem cells were divided into control group,mechanical stimulation group(fluid shear mechanics intervention by shaking table),mechanical stimulation + IFT88 silencing group(mechanical stimulation + silencing IFT88 expression with siRNA).After 24 hours of intervention,qRT-PCR was utilized to determine the expression of transforming growth factor β1 and bone morphogenetic protein 2.Western blot assay was used to detect the expression of phosphorylated SMAD2/3 protein.Immunofluorescent staining of primary cilia was conducted and morphology was analyzed. RESULTS AND CONCLUSION:Shear stress stimulation could promote the transcriptional activity of transforming growth factor β1 and bone morphogenetic protein 2 genes,and increase the expression of phosphorylated SMAD2/3 protein.After siRNA interfered with primary cilia,this mechanical response effect was significantly reduced.There was a Spearman correlation between the change ratio of the primary cilium area of bone marrow stromal stem cells and the increased ratio of transforming growth factor β1 and bone morphogenetic protein 2 gene transcription.These findings indicate that primary cilia/intraflagellar transport mediates the activation of fluid shear stress-responsive transforming growth factor β1/bone morphogenetic protein 2/SMAD signaling pathway and promotes osteogenic differentiation of bone marrow stromal stem cells.

Objective:To investigate the molecular biological mechanism of Bw07 allele and its transferase alteration carried by a proband of ABw07 subtype.Methods:A 2-year-old male child was selected as the research object. The peripheral blood of the proband and his parents was identified for ABO blood type by the test tube method, and the ABO subgroup PCR-SSP detection and ABO gene sequencing were performed on the three individuals to determine their blood type genotypes. Finally, the effect of the p.Arg352Gln mutation on Bw07 transferase was verified by virtual mutation, DUET structure prediction, molecular dynamics analysis, and in vitro cellular experiments.Results:The serological phenotypes of the proband and his mother were ABw and Bw, respectively, while his father was normal A. The ABO subgroup PCR-SSP assay identified the three genotypes as Bw07/A, Bw07/O, and A/A, respectively.Sanger sequencing further verified that the proband and his mother carried the Bw07 gene, and virtual mutation showed that the intermolecular forces were weakened by the R352Q mutation. DUET predicted that this p.Arg352Gln mutation could affect the thermodynamic stability of Bw07 transferase. Molecular dynamics analysis confirmed that the alteration of thermodynamic stability was mainly related to the appearance of large fluctuations in the amino acid backbone atoms in the 125-133, 193-198 and 336-354 regions, and in vitro cellular experiments further verified the weakened antigen synthesis of Bw07 transferase.Conclusion:The formation of the ABw07 phenotype is associated with the mutation of the highly conserved Arg352 to Gln in Bw07 transferase.

Recently,increasing attention has been paid to the study of orthostatic hypotension.Othostatic hypotension is a common systemic multisystem disease,with many clinical symptoms such as dizziness,headache,and blurred vision,which have a great impact on the quality of life of patients.Othostatic hypotension is divided into initial upright hypotension,delayed blood pressure recovery,classical orthostatic hypotension and delayed orthostatic hypotension.This paper aims to explore the research progress and clinical application value of delayed othostatic hypotension,and provide some reference for clinical diagnosis and treatment.

Objective:To explore the molecular basis for an individual with Bel subtype of the ABO blood type due to a novel c. 620T>C variant gene, and assess its impact on the structure of GTB transferase.Methods:An individual who had visited the First Affiliated Hospital of Zhengzhou University on February 11, 2023 was selected as the study subject. ABO phenotyping was initially conducted with serological methods, which was followed by direct sequencing of 7 exons of the ABO gene. Subsequently, single-strand sequencing was carried out by using allele-specific primers, and the variant in the B transferase was homology-modeled using the Modeller software. The impact of the variant on the transferase′s spatial structure was analyzed with the PyMOL software. Results:The serological phenotype of the patient was identified as the Bel subtype. Direct sequencing revealed that she has harbored a novel c. 620T>C variant, resulting in a p. Leu207Pro substitution in the polypeptide chain. Combined with single-strand sequencing, her genotype was ultimately determined as ABO* BELnew/ ABO* O.01.02. Three-dimensional protein structure modeling showed that, compared with the wild type, the distance of one hydrogen bond between Proline and Glycine at position 272 has increased, along with disappearance of another hydrogen bond. Conclusion:The novel c. 620T>C (p.Leu207Pro) variant of B allele may affect the structural stability of the glycosyltransferase. The weakened enzyme activity in turn may lead to reduced B antigen expression, manifesting as the Bel subtype by serological analysis.

Objective:To study the molecular basis for a proband with A subtype B of the ABO blood group and explore the influence of amino acid variant on the activity of glycosyltransferase (GT).Methods:A proband who had presented at the First Affiliated Hospital of Zhengzhou University on July 2, 2020 was selected as the study subject. Serological identification of the ABO blood groups of the proband and her family members were performed by gel card and test tube methods. The ABO gene of the proband was identified by PCR-sequence specific primers (PCR-SSP) and DNA sequencing. A 3D molecular homologous model was constructed to predict the impact of the variant on the stability of α-(1→3)-D-N-acetylgalactosamine transferase (GTA). Results:The red blood cells of the proband, her mother and two younger brothers showed weak agglutination with anti-A and strong agglutination with anti-B. The sera showed 1~2+ agglutination with Ac and no agglutination with Bc. Based on the serological characteristics, the proband was identified as AwB subtype. Pedigree analysis suggested that the variant was inherited from her mother. The blood group of the proband was identified as A223B type by PCR-SSP. ABO gene sequencing analysis showed that the proband has harbored heterozygous variants of c. 297A>G, c. 467C>T, c. 526C>G, c. 657C>T, c. 703G>A, c. 796C>A, c. 803G>C, c. 930G>A and c. 1055insA. Based on the results of clone sequencing, it was speculated that the genotype was ABO* A223/ ABO* B.01. There were c. 467C>T and c. 1055insA variants compared with ABO* A1.01, and c. 1055insA variant compared with ABO* A1.02. Homologous modeling showed that the C-terminal of A223 GT was significantly prolonged, and the local amino acids and hydrogen bond network have changed. Conclusion:Above results revealed the molecular genetics mechanism of A223B subtype. The c. 1055insA variant carried by the proband may affect the enzymatic activity of GTA and ultimately lead to weakening of A antigen.

Objective:To explore the RH genotype for a female with RhD(-) blood type and its molecular basis. Methods:A 26-year-old female who had attended the outpatient clinic of the First Affiliated Hospital of Zhengzhou University in August 2019 was selected as the study subject. Peripheral blood samples were collected from the proband and her parents for Rh phenotyping with gel card method. PCR-sequence-based typing (PCR-SBT) and DNA sequencing were used to determine the RHD zygosity and RH genotype of the proband and her parents. Homology modeling of Rh proteins was performed with bioinformatic software, and protein structural alterations caused by the variant was simulated by molecular dynamics. This study was approved by the Medical Ethics Committee of the First Affiliated Hospital of Zhengzhou University (Ethics No. 2023-KY-0870-003). Results:Serological tests showed that the proband and her father both had weakened e antigen of the Rh phenotype. PCR-SBT and DNA sequencing showed that the genotypes of the proband and her parents were dce/ dCE, dce/ DcE and dCE/ DcE, respectively. And the genotypes of the RHD and RHCE of the proband were RHD*01N.01/ RHD*01N.16, RHCE*01.01/RHCE*04, respectively. Protein simulation and molecular dynamics analysis revealed that the ce_16C variant resulted from RHCE* ce (c.48G>C) may alter the structure of intracellular and extracellular loops, mainly affecting the mobility of extracellular loops 2, 6 and intracellular loops 3, 4. Conclusion:Variant of the RHCE* ce allele c. 48G>C probably underlay the weakened e antigen in this proband.

Objective To statistically analyze the perioperative results of patients with ABO-incompatible kidney trans-plantation(ABOi-KT),in order to explore the changes in blood group antibody of type-A/B recipients.Methods A total of 33 cases of blood group A/B ABOi-KT recipients in our hospital from January 2021 to October 2023 were recruited and divided into two groups of group A(n=18)and group B(n=15)according to the different blood types of recipient.The effects of preoperative plasmapheresis on antibody titer,antibody rebound and renal function after operation(serum urea ni-trogen,creatinine and estimated glomerular filtration rate on the 1st,3rd,7th and 14th day)were analyzed between the two groups.According to the postoperative rebound of blood type antibodies,33 recipients were divided into antibody rebound group(n=7)and non rebound group(n=26),and the differences in initial blood type antibody titers between the two groups were analyzed.Results There was no significant difference in the clearance rate of IgM with preoperative plasma ex-change between the two groups(Z=-0.26,P＞0.05);Levels of serum urea nitrogen and creatinine on the 1st,3rd,7th and 14th day after operation between group A and group B were not statistically significant(P＞0.05),the same as eGFR.Group B was more prone to rebound antibody compared with group A(P＜0.05).There was a significant difference in the in-itial IgM antibody titer between the blood type antibody rebound group and the non rebound group(Z=-2.127,P＜0.05),but no statistically significant difference in the initial IgG antibody titer(Z=-1.835,P＞0.05)between the two groups was found.Conclusion The patients type B receiving type AB kidney donors are more prone to rebound antibody after ABOi-KT operation compared to the the patients type A receiving type AB.

Objective:To investigate the relationship between serum soluble receptor activator of nuclear factor-κB ligand (sRANKL), Omentin-1 levels and postmenopausal osteoporosis (PMOP) .Methods:A total of 310 menopausal patients admitted to Qingdao Municipal Hospital from Jun. 2017 to Jul. 2021 were selected, including 165 patients with PMOP and 145 women with simple menopause as the control group. Serum sRANKL and Omentin-1 levels were detected by ELISA. Bone mineral density and bone metabolism indexes [N-terminal propeptide of typeⅠprecollagen (PINP), bone alkaline phosphatase (BALP), β isomer of the C-terminal telopeptide of type Ⅰ collagen (β-CTX) and osteocalcin (OC) ] were compared between the two groups. The correlation between serum sRANKL and Omentin-1 levels and bone mineral density and bone metabolism indexes in PMOP patients was analyzed by Pearson. The predictive value of sRANKL and Omentin-1 to PMOP was analyzed by ROC curve. Logistic regression analysis of the influence of multiple factors on PMOP.Results:Compared with the control group (15.62±4.41) (42.56±8.53), the serum sRANKL level (26.63±8.12) was increased and Omentin-1 level (32.32±5.52) was decreased in PMOP group ( t=14.55, P<0.001; t=12.69, P<0.001). The serum sRANKL in PMOP group was positively correlated with PINP, β-CTX and OC, while the serum Omentin-1 level was negatively correlated with the above indexes by Pearson analysis. ROC curve showed that serum sRANKL and Omentin-1 had important reference significance in predicting PMOP. Logistic regression suggested that increased sRANKL and decreased Omentin-1 were risk factors for PMOP. Conclusion:Serum sRANKL and Omentin-1 in patients with PMOP are correlated with bone mineral density and bone metabolism, and have potential as diagnostic targets of PMOP.