Objective Currently, there is no commercially available quantitative detection kit for the main Felis domestic allergen (Fel d 1) in China. To establish a rapid detection method for Fel d 1, this study aims to prepare monoclonal antibodies against Fel d 1 protein. Methods The codon preference of Escherichia coli was utilized to optimize and synthesize the Fel d 1 gene. The prokaryotic expression plasmid pET-28a-Fel d 1 was constructed and used to express and purify the recombinant Fel d 1 protein. Subsequently, the recombinant protein was immunized into BALB/c mice and monoclonal antibodies (mAbs) were prepared by the hybridoma technique. An indirect ELISA was established using the recombinant Fel d 1 as the coating antigen, and hybridoma cell lines were screened for positive clones. The specificity and antigenic epitopes of the mAbs were confirmed by Western blot analysis. Finally, the selected hybridoma cells were injected into the peritoneal cavities of BALB/c mice for large-scale monoclonal antibody production. Results The recombinant plasmid pET-28a-Fel d 1 was successfully constructed, and soluble Fel d 1 protein was obtained after optimizing the expression conditions. Western blot and antibody titer assays confirmed the successful isolation of two hybridoma cell lines, 7D11 and 5H4, which stably secreted mAbs specific to Fel d 1. Antibody characterization revealed that the 5H4 mAb was of the IgG2a subtype and could recognize the amino acid region 105-163 of Fel d 1, while the 7D11 mAb was the IgG1 subtype and could recognize the amino acid region 1-59. Conclusion The high-purity recombinant Fel d 1 protein produced in this study provides a promising alternative for clinical immunotherapy of cat allergies. Furthermore, the monoclonal antibody prepared in this experiment lays a material foundation for the in-depth study of the biological function of Fel d 1 and the development of ELISA detection.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice, Inbred BALB C ; Cats ; Mice ; Allergens/genetics* ; Glycoproteins/genetics* ; Enzyme-Linked Immunosorbent Assay ; Hybridomas/immunology* ; Recombinant Proteins/genetics* ; Female ; Antibody Specificity

BACKGROUND:Natural bone morphogenetic protein 2 disperses and degrades rapidly in vivo,reducing local concentration and therapeutic efficacy.Simply combining bone morphogenetic protein 2 with tissue engineering scaffolds could not stay in vivo for a long time,making it difficult to achieve good sustained and controlled release effects.OBJECTIVE:To prepare and test the biological properties and chondrogenic induction effect of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold.METHODS:SD rat tail collagen was extracted and a collagen cartilage scaffold was prepared using a vacuum freeze-drying machine chemical crosslinking method.The plasmid expressing collagen-binding domain-bone morphogenetic protein 2 was constructed by rapid cloning C112 homologous recombination,constructed by genetic engineering,and introduced into E.coli,and then collagen-binding domain-bone morphogenetic protein 2 was isolated and purified.Natural bone morphogenetic protein 2 and collagen-binding domain-bone morphogenetic protein 2 were combined with collagen cartilage scaffolds,respectively,to detect the release level of bone morphogenetic protein 2 in the scaffolds.The biocompatibility of collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold was detected by CCK-8 assay and F-Actin staining.Bone marrow mesenchymal stem cells were implanted on two kinds of collagen cartilage scaffolds for chondrogenic induction,and their chondrogenic induction activity was tested.RESULTS AND CONCLUSION:(1)The binding rate of collagen-binding domain-bone morphogenetic protein 2 to collagen cartilage scaffolds was higher than that of natural bone morphogenetic protein 2(P<0.05).After being immersed in PBS for 7 days in vitro,the release of bone morphogenetic protein 2 in the collagen-binding domain bone morphogenetic protein 2-collagen cartilage scaffold was smaller than that in the natural bone morphogenetic protein 2-collagen cartilage scaffold(P<0.05).The results of the CCK-8 assay and F-Actin staining showed that the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold had no obvious cytotoxicity and had good biocompatibility.(2)After 14 days of chondrogenic induction,ELISA detection demonstrated that the expressions of agglutincan and type Ⅱ collagen A1 in the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold group were higher than those in the natural bone morphogenetic protein 2-collagen cartilage scaffold group(P<0.05).Under scanning electron microscopy,more bone marrow mesenchymal stem cells were observed on the inner wall of the pores of the two groups of scaffolds,and the cell morphology and size were the same,and the cells were closely arranged,without cell fragmentation or abnormal morphology.(3)The results indicate that the collagen-binding domain-bone morphogenetic protein 2-collagen cartilage scaffold has good biological properties and chondrogenic induction activity.

Objective:To analyze the clinical phenotype and genetic basis of a Chinese pedigree affected with Otopalatodigital syndrome type 1 (OPD1).Methods:A pedigree which was evaluated at the Department of Endocrinology, General Hospital of the Central Theater Command on December 3, 2020 was selected as the study subject. Clinical phenotype and genetic features of the proband were analyzed. Whole exome sequencing was employed to screen for genetic variants in the proband, and Sanger sequencing was used to verify the candidate variants in the proband′s mother, uncle, maternal aunt, and paternal aunt. Pathogenicity analysis was also conducted for the candidate variants.Results:The proband, a 16-year-old male, had shown distinctive facial features including mildly prominent eyebrows, down-slanting palpebral fissures, hypertelorism, and depressed nasal bridge. Additionally, he had clubbing of bilateral thumbs and big toes, and central type diabetes insipidus. Genetic sequencing revealed that he has harbored a heterozygous c. 586C>T (p.R196W) missense variant of the FLNA gene (NM_001110556.2), which was also carried by his mother and uncle. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), this variant was classified as likely pathogenic (PM1+ PM2_Supporting+ PP2+ PP3+ PS4 Supporting). Conclusion:The heterozygous c. 586C>T (p.R196W) variant of the FLNA gene probably underlay the pathogenesis in this OPD1 family. The central type diabetes insipidus in the proband may represent a newly discovered phenotype of OPD1. Above finding has contributed crucial information for the comprehensive understanding of the clinical manifestations and pathogenic mechanisms of OPD1.

Objective To understand the awareness of the emergency physicians for thrombolytic thera-py recommended by ST-segment elevation myocardial infarction(STEMI)guidelines and implementation sit-uation,and to analyze the related influencing factors.Methods Relying on Chengdu Emergency Quality Con-trol Center,the questionnaires were distributed to the hospitals of expert group members and the hospitals of the medical union from April to July 2023 to investigate the awareness,implementation status and training status of the emergency doctors in Chengdu area on the STEMI thrombolytic therapy.The causes affecting thrombolysis decision-making were analyzed.Results A total of 137 hospitals participated in the survey.Whether the treatment system and type of chest pain,chest pain center,percutaneous coronary intervention(PCI)qualified hospitals or departments carrying out the training and hospital grade were correlated to whether STEMI patients were thrombolyzed within 12 h before transport(P＜0.05).Whether the PCI quali-fied hospital,chest pain center,chest pain treatment system and type,carrying training,hospital grade,geo-graphical location,transport duration,and thrombolytic indication understanding situation were not related to whether thrombolytic therapy was recommended for the duration from the first medical contact(FMC)to PCI(FMC-PCI)≥120 min(P＞0.05).The multivariate logistic regression analysis showed that whether the de-partment carrying out the training was an influential factor for whether thrombolytic therapy was carried out within 12 h before transport in STEMI onset(P＜0.05).The hospital grade was a influencing factor for whether thrombolysis in non-chest pain treatment system was carried before transport within 12 h of the onset of STEMI.The main reason for STEMI patients being directly transfered treatment without thrombolysis within 12 h of onset was because they knew that thrombolysis was needed but did not know how to do it(50.00％).The awareness rate of thrombolytic indication in non-main urban area was higher than that in main urban area(P＜0.05).The carrying out department training rate of PCI qualified hospitals was higher than that of non-PCI qualified hospitals(P＜0.05).The receiving superior hospital training rate also had difference among different hospital grades and geographical locations.Conclusion Conducting the thrombolysis training and enhancing the learning of treatment processes directly affect the emergency physicians'choice of reperfu-sion strategies for the patients with STEMI.Continuous promotion of the construction of chest pain center or chest pain treatment unit could further increase the early reperfusion rate of STEMI.

This study aims to explore the diagnostic value of inflammation-related genes in peripheral blood mononuclear cells in bronchopulmonary dysplasia (BPD). By using bioinformatics analysis, three datasets including GSE32472, GSE125873, and GSE220135, which contain whole-genome expression profile data of 251 neonates, were included. The GSE32472 dataset was used as a training dataset to detect differentially expressed genes between non-BPD and BPD neonates in peripheral blood mononuclear cells. The gene enrichment analysis (GSEA) was used to detect the pathway enrichment of up-regulated genes in BPD newborns. The main regulatory factors analysis (MRA) algorithm was used to filter the main regulatory genes in the inflammation-related pathway (GO:0006954). After obtaining the main regulatory genes, the expression of the main regulatory genes in the GSE32472, GSE125873, and GSE220135 datasets was detected. Through the logistic regression model, risk scoring was conducted for neonates, and the risk scores of non-BPD and BPD neonates were compared. Lastly, the classification performance of the model was evaluated using the area under the curve (AUC). The results showed that compared with non-BPD neonates, there were 486 up-regulated genes and 433 down-regulated genes in the peripheral blood mononuclear cells of BPD neonates. The inflammation-related pathway was highly enriched in the up-regulated genes. Ultimately, phospholipase C beta 1 (PLCB1), nidogen 1 (NID1), serum response factor binding protein 1 (SRFBP1), centrosomal protein 72 (CEP72), excision repair cross complementation group 6 like (ERCC6L), and peptidylprolyl isomerase like 1 (PPIL1) were identified as the main regulatory genes. The prediction model′s calculation formula for risk score was PLCB1×0.26+NID1×0.97+SRFBP1×1.58+CEP72×(-0.36)+ERCC6L×2.14+PPIL1×0.67. The AUCs in the GSE32472 test dataset, GSE125873 dataset, and GSE220135 dataset were 0.88, 0.86, and 0.89, respectively. This prediction model could distinguish between non-BPD and BPD neonates. In conclusion, the prediction model based on inflammation-related pathway genes has a certain diagnostic value for BPD.

This study aims to explore the diagnostic value of inflammation-related genes in peripheral blood mononuclear cells in bronchopulmonary dysplasia (BPD). By using bioinformatics analysis, three datasets including GSE32472, GSE125873, and GSE220135, which contain whole-genome expression profile data of 251 neonates, were included. The GSE32472 dataset was used as a training dataset to detect differentially expressed genes between non-BPD and BPD neonates in peripheral blood mononuclear cells. The gene enrichment analysis (GSEA) was used to detect the pathway enrichment of up-regulated genes in BPD newborns. The main regulatory factors analysis (MRA) algorithm was used to filter the main regulatory genes in the inflammation-related pathway (GO:0006954). After obtaining the main regulatory genes, the expression of the main regulatory genes in the GSE32472, GSE125873, and GSE220135 datasets was detected. Through the logistic regression model, risk scoring was conducted for neonates, and the risk scores of non-BPD and BPD neonates were compared. Lastly, the classification performance of the model was evaluated using the area under the curve (AUC). The results showed that compared with non-BPD neonates, there were 486 up-regulated genes and 433 down-regulated genes in the peripheral blood mononuclear cells of BPD neonates. The inflammation-related pathway was highly enriched in the up-regulated genes. Ultimately, phospholipase C beta 1 (PLCB1), nidogen 1 (NID1), serum response factor binding protein 1 (SRFBP1), centrosomal protein 72 (CEP72), excision repair cross complementation group 6 like (ERCC6L), and peptidylprolyl isomerase like 1 (PPIL1) were identified as the main regulatory genes. The prediction model′s calculation formula for risk score was PLCB1×0.26+NID1×0.97+SRFBP1×1.58+CEP72×(-0.36)+ERCC6L×2.14+PPIL1×0.67. The AUCs in the GSE32472 test dataset, GSE125873 dataset, and GSE220135 dataset were 0.88, 0.86, and 0.89, respectively. This prediction model could distinguish between non-BPD and BPD neonates. In conclusion, the prediction model based on inflammation-related pathway genes has a certain diagnostic value for BPD.

Objective To investigate the plasma level of interleukin-31(IL-31)in patients with pulmonary arterial hypertension(PAH)and its clinical relevance.Methods The patients who were diagnosed as PAH in Zhongshan Hospital,Fudan University from January 1,2021 to December 30,2023(PAH group)and the healthy people in the same period(control group)were selected.The clinical data and follow-up records were collected.Plasma levels of IL-31,IL-1β,IL-6,IL-10,IL-12p70,monocyte chemoattractant protein-1(MCP-1),tumor necrosis factor-α(TNF-α)and transforming growth factor-β1(TGF-β1)were detected by enzyme-linked immunosorbent assay(ELISA).Pearson correlation test was used to evaluate the correlations between IL-31 and right cardiac catheterization parameters,echocardiography parameters and blood indices in patients with PAH.Cox proportional hazard model was used to analyze the prognostic factors of patients in PAH group.Results A total of 50 patients with PAH and 22 healthy controls were included.There was no significant difference in age,gender,body mass index and left ventricular ejection fraction between the two groups.Compared with the control group,the plasma level of IL-31 in the PAH group was significantly higher(168.82[149.14,177.26]pg/mL vs 152.76[145.58,159.41]pg/mL,P=0.001).Pearson correlation test showed that the plasma level of IL-31 in PAH patient was positively correlated with mean pulmonary artery pressure(r=0.652,P＜0.001)and pulmonary vascular resistance(r=0.651,P＜0.001),but was negatively correlated with tricuspid annular plane systolic excursion(r=-0.496,P＜0.001).Cox proportional hazard model showed that higher plasma level of IL-31 was an independent predictor of readmission for heart failure/all-cause mortality in patients with PAH(HR=1.130,95％CI 1.052-1.214,P=0.001).Conclusions Plasma level of IL-31 may be significantly increased in patients with PAH and be positively correlated with the severity of PAH,and elevated level of IL-31 is predictive of poor prognosis in PAH patients.

Objective:To investigate the accuracy, effectiveness and feasibility of MassARRAY genotyping assay in the diagnoses of neonatal genetic metabolic diseases.Methods:This is a retrospective study. From December 2016 to January 2020, newborns were screened by tandem mass spectrometry at the Zhejiang Newborn Screening Center, among which the data of 7 922 suspected positive cases of genetic metabolic diseases were collected. These patients were then tested for the common variants of 27 genetic metabolic diseases by MassARRAY genotyping assay, along with further testing using Sanger or next-generation sequencing used to verify and/or further search for potential variants.Results:A total of 1 408 cases were tested with MassARRAY. Among these, 307 cases were confirmed with certain genetic metabolic diseases. The detection rate of hyperphenylalaninemia was the highest, followed by primary carnitine deficiency, short acyl-coA dehydrogenase deficiency and methylmalonic acidemia. With these cases, the consistency of Sanger sequencing and MassARRAY was 100% (307/307). Another 287 cases were identified as carriers by MassARRAY with a 49.1% (141/287) consistency in reference to Sanger sequencing, mainly involving SLC22A5 and MCCC1 genes. Meanwhile, 50.8% (146/287) of these cases were found to have another variant mainly involving PAH, PTS and ACADS genes. The remaining 814 cases have no variants; 158 cases out of these patients have continuously abnormal amino acids, acyl carnitines, urine organic acid and/or other biochemical indices, and were tested by next-generation sequencing, among which 38% (60/158) were detected with two variants. In this study, a total of 513 patients with genetic metabolic disease were diagnosed, and the detection rate of MassARRAY was 59.8% (307/513). Conclusions:MassARRAY genotyping assay can be used as an early molecular screening method for neonatal genetic metabolic diseases. The detection rate is particularly high in diseases with a high concentration of hotspot variants, such as hyperphenylalaninemia and primary carnitine deficiency. The future application value of MassARRAY should be further improved by continuously optimizing its ability to identify new disease genes and potential variable sites.

Objective:To explore the outcome of sponge forceps assisted threading with Speedbridge technique for the treatment of acute closed Achilles tendon rupture.Methods:A retrospective case series study was conducted on 20 patients with acute closed Achilles tendon rupture treated in Zhengzhou Orthopedic Hospital from December 2019 to December 2021. There were 18 males and 2 females, with age range of 24-43 years [(29.5±7.6)years]. All patients were with unilateral injury, involving the left side in 13 patients and right side in 7. Examinations revealed a palpable defect in the Achilles tendon and positive Thompson test. A longitudinal incision was made at the medial edge of the ruptured tendon. Three nonabsorbable sutures were passed through the proximal stump with sponge forceps, bypassed the rupture site and fixed directly into the calcaneal bone. The disrupted tendon ends were aligned by the tendon-bundle technique using 4-0 absorbable sutures. The operation time and incision length were documented. The ankle joint range of motion (dorsiflexion/plantar flexion), American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and Achilles tendon total rupture score (ATRS) in the affected and healthy side were compared at 3, 6 and 12 months postoperatively. The wound healing and complications were observed.Results:All patients were followed up for 12-16 months [(13.2±2.5)months]. The operation time was 40-66 minutes [(52.0±10.3)minutes], with the incision length of 3-4 cm [(3.3±0.7)cm]. In the affected side at 3 and 6 months postoperatively, the ankle joint dorsiflexion [(5.6±1.5)°, (10.5±0.2)°] and plantar flexion [(28.4±3.2)°, (33.5±1.5)°] showed statistically significant difference compared with the healthy side (all P<0.05). The ankle joint dorsiflexion [(13.9±0.7)°] and plantar flexion [(38.3±4.4)°] in the affected side were not statistically different from that of the healthy side at 12 months postoperatively (all P>0.05). The AOFAS ankle-hindfoot score was (58.3±5.4)points, (84.9±7.1)points and (91.8±6.3)points at 3, 6 and 12 months postoperatively, showing a gradual rise (all P<0.05). The ATRS was (60.5±4.9)points, (85.5±9.0)points and (93.1±5.7)points at 3, 6 and 12 months postoperatively, showing a gradual rise (all P<0.05). All incisions were healed primarily. No patients had wound infection, nerve injury or re-rupture. Pain at the anchor insertion site occurred in 2 patients at 1 month after operation and relieved after active functional rehabilitation at 4 months after operation. Transient pain at the Achilles tendon insertion occurred in 1 patient at 6 months after operation, and relieved after 2 weeks of oral non-steroidal anti-inflammatory drugs treatment. Conclusion:For acute closed Achilles tendon rupture, sponge forceps assisted threading with Speedbridge technique can attain short operation time, small incision and good functional recovery, with few complications.

Objective:To retrospect the blood transfusion status of patients with extensive burns in multiple centers and analyze its influencing factors.Methods:A retrospective case series study was conducted. Clinical data of 455 patients with extensive burns who met the inclusion criteria and were admitted to the burn centers of 3 hospitals from January 2016 to June 2022 were collected, including 202 patients from the First Affiliated Hospital of Nanchang University, 179 patients from the Second Affiliated Hospital of Zhejiang University School of Medicine, and 74 patients from the First Affiliated Hospital of Anhui Medical University. The following data were collected from patients during their hospitalization, including infusion of red blood cells, plasma, and platelets during hospitalization; age, gender, body mass index, combined underlying diseases, cause of injury, time of admission after injury, type of admission, total burn area, full-thickness burn area, combination of inhalation injury, combination of other trauma, and combination of pulmonary edema; the blood lactic acid, serum creatinine, total bilirubin, and albumin values within 24 h of admission; combination of bloodstream, wound, lung, and urinary tract infection, and combination of sepsis; the number of escharectomy or tangential excision and skin grafting surgery (hereinafter referred to as surgery) and total surgical blood loss volume; occurrence of hemoglobin<70 g/L, admission to intensive care unit (ICU), conduction of mechanical ventilation and continuous renal replacement therapy (CRRT), length of hospital stay, and prognosis were recorded. In 602 surgeries of patients within 14 days after injury, data including area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and surgical blood loss volume per surgery, operation site, and use of tourniquet and wound graft were collected. Data were statistically analyzed with Mann-Whitney U test, Kruskal-Wallis H test, and Spearman correlation analysis. Combined with the results of single factor analysis and clinical significance, multiple linear regression analysis was performed to screen the independent influencing factors of red blood cell infusion volume and plasma infusion volume, as well as blood loss volume per surgery. Results:During the whole hospitalization period, 437 (96.0%) patients received blood transfusion therapy, including 435 (95.6%) patients, 410 (90.1%) patients, and 73 (16.0%) patients who received transfusion of plasma, red blood cells, and platelets, respectively. The patients were mainly male, aged 18 to 92 years. There were statistically significant differences in the plasma infusion volume among patients with different combination of underlying disease, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.06, -4.67, -2.11, -6.13, -9.56, -4.93, -8.08, -4.78, -9.12, -6.55, -9.37, -11.46, and -7.17, respectively, P<0.05). The total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, albumin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the plasma infusion volume of patients (with r values of 0.39, 0.51, 0.14, 0.28, -0.13, 0.47, and 0.56, respectively, P<0.05).There were statistically significant differences in the red blood cell infusion volume among patients with different gender, combination of inhalation injury, combination of other trauma, combination of pulmonary edema, combination of bloodstream infection, combination of wound infection, combination of lung infection, combination of urinary tract infection, combination of sepsis, occurrence of hemoglobin value <70 g/L, admission to ICU, conduction of mechanical ventilation, and conduction of CRRT (with Z values of -2.00, -4.34, -3.10, -4.22, -8.24, -7.66, -8.62, -4.75, -7.42, -9.36, -6.12, and -8.31, -6.64, respectively, P<0.05). The age, total burn area, full-thickness burn area, blood lactic acid value within 24 h of admission, serum creatinine value within 24 h of admission, total bilirubin value within 24 h of admission, number of surgeries, and total surgical blood loss volume were correlated with the red blood cell infusion volume of patients (with r values of 0.12, 0.22, 0.49, 0.09, 0.18, 0.13, -0.15, 0.69, and 0.77, respectively, P<0.05). Combined underlying diseases, full-thickness burn area, combined pulmonary edema, serum creatinine value within 24 h of admission, combined sepsis, conduction of CRRT, number of surgeries, and total surgical blood loss volume were the independent influencing factors for plasma infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.09, 0.16, 0.12, 0.07, 0.11, 0.15, 0.31, and 0.26, respectively, P<0.05). Female, full-thickness burn area, serum creatinine value within 24 h of admission, combined sepsis, occurrence of hemoglobin value <70 g/L, conduction of CRRT, and total surgical blood loss volume were the independent influencing factors for red blood cell infusion volume during hospitalization in patients with extensive burns (with standardized regression coefficients of 0.10, 0.12, 0.10, 0.11, 0.05, 0.19, and 0.54, respectively, P<0.05). There were statistically significant differences in blood loss volume per surgery of patients with different surgical site and wound graft (with Z values of -2.54 and -2.27, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting and duration of operation were correlated with the blood loss volume per surgery of patients (with r values of 0.40 and 0.21, respectively, P<0.05). The area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts were the independent influencing factors for blood loss volume per surgery of patients with extensive burns (with standardized regression coefficients of 0.41, 0.16, and 0.12, respectively, P<0.05). Conclusions:The major factors influencing blood transfusion status in patients with extensive burns are female, combined underlying diseases, full-thickness burn area, serum creatinine value within 24 h of admission, combined pulmonary edema, occurrence of hemoglobin value <70 g/L, combined sepsis, conduction of CRRT, number of surgery, and total surgical blood loss volume. In addition, the area of escharectomy or tangential excision and skin graft harvesting, duration of operation, and active wound grafts indirectly affect the patient's blood transfusion status by affecting the blood loss volume per surgery.