[Objective] To conduct a retrospective statistical comparison of alanine aminotransferase (ALT) test values in blood donors prior to blood collection, aiming to analyze the objective characteristics of the population with elevated ALT levels (ALT>50 U/L) and provide reference data for adjusting the screening eligibility threshold for ALT. [Methods] The preliminary ALT screening data of 30 341 blood donor samples collected prior to blood donation from three smart blood donation sites at the Shenzhen Blood Center between 2022 and 2023 were extracted and compared with data from a health examination department of a tertiary hospital in Shenzhen (representing the general population, n=24 906). Both datasets were categorized and statistically described. A retrospective analysis was conducted to examine the associations between ALT test results and factors such as donors' gender, age, ethnicity, donation site, donation season, and frequency of blood donation. [Results] The ALT levels in both blood donors and the general population were non-normally distributed. The 95th percentile of ALT values was calculated as 61.4 U/L (male: 67.8 U/L, female: 39.3 U/L) for blood donors and 58.1 U/L (male: 63.7 U/L, female: 51.2 U/L) for the general population. The non-compliance rates (ALT>50 U/L) were 7.65% (2 321/30 341) in blood donors and 7.08% (1 763/24 906) in the general population. There were significant differences (P<0.05) in the ALT failure rate among blood donors based on gender, age, and donation site, but no significant differences (P>0.05) during the blood donation season. There was no statistically significant difference (P>0.05) in the positive rates of four serological markers (HBsAg, anti HCV, HIV Ag/Ab, anti TP) for blood screening pathogens between ALT unqualified and qualified individuals (2.05% vs 1.5%). If the ALT qualification threshold was raised from 50 U/L to 90 U/L, the non qualification rates of male and female blood donors would decrease from 9.82% (2 074/21 125) to 2.23% (471/21 125) and from 2.70% (249/9 216) to 0.75% (69/9 216), respectively. Among the 154 blood donors who donated blood more than 3 times, 88.31% of the 248 ALT test results were in the range of 50-90 U/L. Among them, 9 cases had ALT>130 U/L, and ALT was converted to qualified in subsequent blood donations. [Conclusion] There are differences in the ALT failure rate among blood donors of different genders and ages, and different blood donation sites and operators can also affect the ALT detection values of blood donors. The vast majority of blood donors with ALT failure are caused by transient and non pathological factors. With the widespread use of blood virus nucleic acid testing, appropriately increasing the ALT qualification threshold for blood donors can expand the qualified population and alleviate the shortage of blood sources, and the risk of blood safety will not increase.

BACKGROUND:Osteonecrosis is an orthopedic disease that severely limits joint function,with complex pathogenesis involving multiple risk factors.Cathepsins,as a class of enzymes that play a key role in bone metabolism,are closely related to the proliferation,differentiation of bone cells,and remodeling of the bone matrix.However,previous studies have mostly focused on descriptive analyses,lacking direct evidence of causal relationships.OBJECTIVE:To clarify the potential causal relationship between cathepsins and osteonecrosis and to explore their possible mechanisms by analyzing large-scale sample data from the FinnGen database.METHODS:We obtained osteonecrosis-related data from the FinnGen database,including R9(a total of 359 399 samples:1 385 cases and 358 014 controls)and R10 versions(a total of 392 580 samples:1 543 cases and 391 037 controls).Single nucleotide polymorphisms associated with nine cathepsins(cathepsin B,E,F,G,H,O,S,L2,and Z)were acquired from a previous study(3 301 individuals).Univariate Mendelian randomization,reverse univariate Mendelian randomization,and multivariate Mendelian randomization analyses were conducted using the inverse variance weighted method,MR-Egger method,weighted median method,simple mode method,and weighted mode method.Initially,Mendelian randomization analysis was performed using osteonecrosis data from R9.Additionally,sensitivity analyses were conducted using Cochran's Q test,MR-Egger intercept,MR-PRESSO global test,and leave-one-out analysis to check for horizontal pleiotropy and heterogeneity.Subsequently,a validation analysis study was carried out on the R10 dataset,and a meta-analysis was conducted to combine the two datasets to explore the joint effect.RESULTS AND CONCLUSION:Univariate Mendelian randomization analysis results showed that higher levels of cathepsin B were significantly associated with a reduced risk of osteonecrosis(inverse variance weighted:odds ratio(OR)=0.865,95％confidence interval(CI):0.762-0.982,P=0.025),and no reverse causal relationship was found between the nine cathepsins and osteonecrosis(P＞0.05).These associations were validated by meta-analysis.Multivariate analysis,using the nine cathepsins as covariates,revealed a reverse causal relationship between the levels of cathepsin Band the risk of osteonecrosis(inverse variance weighted:OR=0.8710,95％CI:0.761-0.997,P=0.045),consistent with the results before adjustment.Sensitivity analyses based on heterogeneity and horizontal pleiotropy suggested that the results were relatively robust.This study suggests that there is a causal relationship between high levels of cathepsin B and the reduced risk of osteonecrosis,and it may serve as a biomarker for osteonecrosis,providing new directions and insights for the diagnosis and treatment of osteonecrosis.Although this study is based on data analysis of European populations,these findings have important implications for Chinese biomedical research,especially in understanding disease mechanisms,developing biomarkers,and formulating treatment strategies.They also encourage similar studies conducted on Chinese populations to explore the impact of racial and genetic background differences on the occurrence of osteonecrosis.

BACKGROUND:Previous studies by the research group have shown that core proteoglycan in Cornus Cervi Col la can enter the bone,promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells,and has a good repair effect on steroid-induced osteonecrosis of the femoral head.OBJECTIVE:To investigate the therapeutic effect and potential mechanism of Cornus Cervi Colla on steroid-induced osteonecrosis of the femoral head in rats by fecal non-targeted fecal metabolomics.METHODS:Thirty SD rats were randomly divided into three groups using a random number table method:the control group(n=10)was injected with normal saline into the right gluteal muscle(injected on the first 3 days of each week for 3 consecutive weeks),and was given pure water gavage(once a day for 6 consecutive weeks).The model group(n=10)was injected with methylprednisolone sodium succinate into the right gluteal muscle(injected on the first 3 days of each week for 3 consecutive weeks)to establish a steroid-induced osteonecrosis of the femoral head model,and was given pure water gavage(once a day for 6 consecutive weeks).The Cornus Cervi Co I la group(n=10)was also established with a steroid-induced osteonecrosis of the femoral head model,and was given Cornus Cervi Col la gavage(once a day for 6 consecutive weeks).After gavage,cecal feces and femoral heads were collected for fecal metabolomics analysis and bone tissue Micro-CT and hematoxylin-eosin staining,respectively.RESULTS AND CONCLUSION:(1)Metabolomics analysis results showed that there were 233 differential metabolites between the Cornus Cervi Col la and model groups,with 65 significantly differing and clearly annotated metabolites.Lipid and amino acid metabolites were significantly increased,with bile acids,sulfated steroids,ephedrine,hypoxanthine,betaine,L-carnitine,B-mouse bile acid,cytidine,4-pyridoxic acid,taurine,N-acetyl-d-glucosamine,and butyric acid being the most impacted(variable weight value VIP＞5).The metabolic pathways of taurine and hypotaurine were crucial in the metabolic regulatory network(pathway impact=0.428 57).(2)Micro-CT scanning results of bone tissue showed that the femoral heads of rats in the model group and the Cornus Cervi Col la group had different degrees of damage;the femoral head contour was irregular;the trabeculae in the subchondral bone of the femoral head were missing and disordered,and some cystic structures were visible.Compared with the model group,the degree of trabecular damage in the rats of the Cornus Cervi Colla group was milder.Hematoxylin-eosin staining results showed that the trabeculae in the subchondral bone of the femoral heads of rats in the model group and the Cornus Cervi Colla group were sparse or interrupted,and the empty bone lacuna rate and adipocyte invasion were increased.Compared with the model group,the empty bone lacuna rate and adipocyte invasion in the subchondral bone of the femoral heads of rats in the Cornus Cervi Colla group were reduced.(3)These results conclude that Cornus Cervi Colla potentially mitigates steroid-induced osteonecrosis of the femoral head through the metabolic processes involving taurine and associated pathways.

Objective:To construct a sizeable naive human Fab phage display antibody library to screen high-affinity specific antibodies in vitro. Methods:Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 126 healthy individuals, subsequently reverse-transcribed into cDNA, and used as a template. PCR amplification was performed to obtain the V H from IgG, IgM and light chain κ, λ, separately, with the initial PCR products serving as templates for a second round of PCR. Overlap extension PCR was employed to generate fragments of the κ and λ light chains. These fragments were ligated with the phage vector pNC3, which harbors the variable region 1 of the heavy chain, to construct a recombinant phage plasmid. This plasmid was then electroporated into competent Escherichia Coli TG1 cells to establish a naive human Fab phage display antibody library. One hundred clones were randomly selected for identification and sequencing, and antibody gene polymorphisms were analyzed using the IMGT database and MAFFT software. Recombinant α-hemolysin from Staphylococcus aureus was utilized to screen Fab antibody fragments through biopanning of the antibody library, followed by random selection of phage ELISA-identified clones. The positive clones (antigen A450∶blank control A450≥2.1) were sequenced. Results:Two large naive Fab phage display antibody libraries were successfully constructed, in which the capacity of κ and λ chain antibody libraries were 1.25×10 11 and 1.54×10 11, respectively. The titers for two antibody libraries were 6.04×10 13 CFU/ml and 3.50×10 13 CFU/ml. The positive transformation insertion rates for κ and λ chain antibody libraries were 96% (96/100) and 100% (100/100), respectively. Sequence analysis revealed that all antibody sequences were unique. The amino acid sequences in the skeletal region were relatively conserved. In contrast, significant variations in the length of the complementarity determining region (CDR) were found, and the diversity of amino acid sequence of the complementary determining region was high, especially the CDR3. Analysis using the IMGT database indicated that the sequences exhibited a broad distribution across variable-diversity-joining gene families. After six rounds of panning, specific phage antibodies enrichment targeting α-hemolysin were achieved. A total of 142 monoclonal antibodies were sequenced, yielding 8 distinct Fab antibody sequences. Conclusion:This study successfully constructed two naive human Fab phage display antibody libraries with large capacity and good diversity, which can be used for screening human antibodies for serum epidemiology.

Objective:To construct a sizeable naive human Fab phage display antibody library to screen high-affinity specific antibodies in vitro. Methods:Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) of 126 healthy individuals, subsequently reverse-transcribed into cDNA, and used as a template. PCR amplification was performed to obtain the V H from IgG, IgM and light chain κ, λ, separately, with the initial PCR products serving as templates for a second round of PCR. Overlap extension PCR was employed to generate fragments of the κ and λ light chains. These fragments were ligated with the phage vector pNC3, which harbors the variable region 1 of the heavy chain, to construct a recombinant phage plasmid. This plasmid was then electroporated into competent Escherichia Coli TG1 cells to establish a naive human Fab phage display antibody library. One hundred clones were randomly selected for identification and sequencing, and antibody gene polymorphisms were analyzed using the IMGT database and MAFFT software. Recombinant α-hemolysin from Staphylococcus aureus was utilized to screen Fab antibody fragments through biopanning of the antibody library, followed by random selection of phage ELISA-identified clones. The positive clones (antigen A450∶blank control A450≥2.1) were sequenced. Results:Two large naive Fab phage display antibody libraries were successfully constructed, in which the capacity of κ and λ chain antibody libraries were 1.25×10 11 and 1.54×10 11, respectively. The titers for two antibody libraries were 6.04×10 13 CFU/ml and 3.50×10 13 CFU/ml. The positive transformation insertion rates for κ and λ chain antibody libraries were 96% (96/100) and 100% (100/100), respectively. Sequence analysis revealed that all antibody sequences were unique. The amino acid sequences in the skeletal region were relatively conserved. In contrast, significant variations in the length of the complementarity determining region (CDR) were found, and the diversity of amino acid sequence of the complementary determining region was high, especially the CDR3. Analysis using the IMGT database indicated that the sequences exhibited a broad distribution across variable-diversity-joining gene families. After six rounds of panning, specific phage antibodies enrichment targeting α-hemolysin were achieved. A total of 142 monoclonal antibodies were sequenced, yielding 8 distinct Fab antibody sequences. Conclusion:This study successfully constructed two naive human Fab phage display antibody libraries with large capacity and good diversity, which can be used for screening human antibodies for serum epidemiology.

Background and aims:Radiofrequency ablation(RFA)is the first-line treatment for early-stage hepato-cellular carcinoma(HCC).However,recurrence after curative RFA remains a significant challenge for HCC patients.Although RFA induces an immune response,the anti-tumor effect is often limited by the immunosuppressive tumor microenvironment.Enhancing anti-tumor immunity is essential to improve treatment efficacy and prevent recurrence.In this study,we explore the efficacy and underlying mechanisms of the combination of RFA and anti-PD-1 in suppressing abscopal and recurrent tumors.Methods:We established a bilateral subcutaneous HCC mouse model and performed complete RFA on the right-flank tumor.Anti-PD-1 or anti-IgG was administered post-RFA.Tumor growth,immune cell profiles,and molecular pathways were assessed using flow cytometry,immunohistochemistry staining,RNA-sequencing,and Western blot.Chemokines released by the tumor were detected by ELISA.An in vivo tumor rechallenge experiment was performed after a complete tumor regression to evaluate the immune memory induced by the RFA+anti-PD-1 treatment.Results:RFA combined with anti-PD-1 significantly suppressed abscopal tumor growth and prolonged survival.Compared with RFA monotherapy,the infiltration of CD8+T cells and dendritic cells was sig-nificantly increased in the combined treatment group,while PMN-MDSCs were markedly reduced.Mechanistically,the chemokine signaling pathway and JAK-STAT signaling pathway were activated in the tumor of the RFA+anti-PD-1 group with upregulation of CXCL10 to recruit CD8+T cells.In addition,the combination therapy induced durable immune memory that inhibited rechallenge tumor outgrowth.Conclusions:Our study discovered that RFA combined with anti-PD-1 induced anti-tumor immunity to inhibit abscopal tumors and durable immune memory to prevent recurrence,suggesting RFA+anti-PD-1 as a potential therapeutic strategy for multifocal HCC and preventing recurrence.

BACKGROUND:Previous studies by the research group have shown that core proteoglycan in Cornus Cervi Col la can enter the bone,promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells,and has a good repair effect on steroid-induced osteonecrosis of the femoral head.OBJECTIVE:To investigate the therapeutic effect and potential mechanism of Cornus Cervi Colla on steroid-induced osteonecrosis of the femoral head in rats by fecal non-targeted fecal metabolomics.METHODS:Thirty SD rats were randomly divided into three groups using a random number table method:the control group(n=10)was injected with normal saline into the right gluteal muscle(injected on the first 3 days of each week for 3 consecutive weeks),and was given pure water gavage(once a day for 6 consecutive weeks).The model group(n=10)was injected with methylprednisolone sodium succinate into the right gluteal muscle(injected on the first 3 days of each week for 3 consecutive weeks)to establish a steroid-induced osteonecrosis of the femoral head model,and was given pure water gavage(once a day for 6 consecutive weeks).The Cornus Cervi Co I la group(n=10)was also established with a steroid-induced osteonecrosis of the femoral head model,and was given Cornus Cervi Col la gavage(once a day for 6 consecutive weeks).After gavage,cecal feces and femoral heads were collected for fecal metabolomics analysis and bone tissue Micro-CT and hematoxylin-eosin staining,respectively.RESULTS AND CONCLUSION:(1)Metabolomics analysis results showed that there were 233 differential metabolites between the Cornus Cervi Col la and model groups,with 65 significantly differing and clearly annotated metabolites.Lipid and amino acid metabolites were significantly increased,with bile acids,sulfated steroids,ephedrine,hypoxanthine,betaine,L-carnitine,B-mouse bile acid,cytidine,4-pyridoxic acid,taurine,N-acetyl-d-glucosamine,and butyric acid being the most impacted(variable weight value VIP＞5).The metabolic pathways of taurine and hypotaurine were crucial in the metabolic regulatory network(pathway impact=0.428 57).(2)Micro-CT scanning results of bone tissue showed that the femoral heads of rats in the model group and the Cornus Cervi Col la group had different degrees of damage;the femoral head contour was irregular;the trabeculae in the subchondral bone of the femoral head were missing and disordered,and some cystic structures were visible.Compared with the model group,the degree of trabecular damage in the rats of the Cornus Cervi Colla group was milder.Hematoxylin-eosin staining results showed that the trabeculae in the subchondral bone of the femoral heads of rats in the model group and the Cornus Cervi Colla group were sparse or interrupted,and the empty bone lacuna rate and adipocyte invasion were increased.Compared with the model group,the empty bone lacuna rate and adipocyte invasion in the subchondral bone of the femoral heads of rats in the Cornus Cervi Colla group were reduced.(3)These results conclude that Cornus Cervi Colla potentially mitigates steroid-induced osteonecrosis of the femoral head through the metabolic processes involving taurine and associated pathways.

BACKGROUND:Osteonecrosis is an orthopedic disease that severely limits joint function,with complex pathogenesis involving multiple risk factors.Cathepsins,as a class of enzymes that play a key role in bone metabolism,are closely related to the proliferation,differentiation of bone cells,and remodeling of the bone matrix.However,previous studies have mostly focused on descriptive analyses,lacking direct evidence of causal relationships.OBJECTIVE:To clarify the potential causal relationship between cathepsins and osteonecrosis and to explore their possible mechanisms by analyzing large-scale sample data from the FinnGen database.METHODS:We obtained osteonecrosis-related data from the FinnGen database,including R9(a total of 359 399 samples:1 385 cases and 358 014 controls)and R10 versions(a total of 392 580 samples:1 543 cases and 391 037 controls).Single nucleotide polymorphisms associated with nine cathepsins(cathepsin B,E,F,G,H,O,S,L2,and Z)were acquired from a previous study(3 301 individuals).Univariate Mendelian randomization,reverse univariate Mendelian randomization,and multivariate Mendelian randomization analyses were conducted using the inverse variance weighted method,MR-Egger method,weighted median method,simple mode method,and weighted mode method.Initially,Mendelian randomization analysis was performed using osteonecrosis data from R9.Additionally,sensitivity analyses were conducted using Cochran's Q test,MR-Egger intercept,MR-PRESSO global test,and leave-one-out analysis to check for horizontal pleiotropy and heterogeneity.Subsequently,a validation analysis study was carried out on the R10 dataset,and a meta-analysis was conducted to combine the two datasets to explore the joint effect.RESULTS AND CONCLUSION:Univariate Mendelian randomization analysis results showed that higher levels of cathepsin B were significantly associated with a reduced risk of osteonecrosis(inverse variance weighted:odds ratio(OR)=0.865,95％confidence interval(CI):0.762-0.982,P=0.025),and no reverse causal relationship was found between the nine cathepsins and osteonecrosis(P＞0.05).These associations were validated by meta-analysis.Multivariate analysis,using the nine cathepsins as covariates,revealed a reverse causal relationship between the levels of cathepsin Band the risk of osteonecrosis(inverse variance weighted:OR=0.8710,95％CI:0.761-0.997,P=0.045),consistent with the results before adjustment.Sensitivity analyses based on heterogeneity and horizontal pleiotropy suggested that the results were relatively robust.This study suggests that there is a causal relationship between high levels of cathepsin B and the reduced risk of osteonecrosis,and it may serve as a biomarker for osteonecrosis,providing new directions and insights for the diagnosis and treatment of osteonecrosis.Although this study is based on data analysis of European populations,these findings have important implications for Chinese biomedical research,especially in understanding disease mechanisms,developing biomarkers,and formulating treatment strategies.They also encourage similar studies conducted on Chinese populations to explore the impact of racial and genetic background differences on the occurrence of osteonecrosis.

BACKGROUND:Osteonecrosis due to drugs is a serious adverse reaction occurring after the application of such drugs.Increasing evidence suggests that the gut microbiota composition is associated with osteonecrosis due to drugs.However,the causal relationship of the gut microbiota to osteonecrosis due to drugs is still unclear. OBJECTIVE:To evaluate the potential causal relationship between the gut microbiota and the risk of osteonecrosis due to drugs using the Mendelian randomization method. METHODS:A two-sample Mendelian randomization study was performed using the summary statistics of gut microbiota from the largest available genome-wide association study meta-analysis(n=13 266)conducted by the MiBioGen consortium as well as the summary statistics of osteonecrosis due to drugs obtained from the FinnGen consortium R9 release data(264 cases and 377 013 controls).Inverse variance weighted,MR-Egger,weighted median,weighted model and simple model were used to examine the causal association between gut microbiota and osteonecrosis due to drugs.Sensitivity analysis was used to test whether the results of the Mendelian randomization analysis were reliable.Reverse Mendelian randomization analysis was performed on all the bacteria as an outcome for effect analysis and sensitivity analysis. RESULTS AND CONCLUSION:Inverse variance weighted estimates suggested that Lentisphaerae(phylum),Lentisphaeria(class),Melainabacteria(class),Gastranaerophilales(order),Rhodospirillales(order),Victivallales(order)and Bifidobacterium(genus)had protective causal effects on osteonecrosis due to drugs.Methanobacteria(class),Bacillales(order),Methanobacteriaceae(family),Lachnospiraceae(family),Methanobacteriales(order),Holdemania(genus),Holdemania(UCG010 group)(genus),Odoribacter(genus)and Tyzzerella3(genus)had negative causal effects on osteonecrosis due to drugs.According to the results of reverse Mendelian randomization analysis,Clostridiaceae1(family),Peptostreptococcaceae(family),Streptococcaceae(family),Clostridiumsensustricto1(genus)and Streptococcus(genus)showed negative causal effects on osteonecrosis due to drugs.However,Eisenbergiella(genus)showed protective causal effects on osteonecrosis due to drugs.None of the bidirectional sensitivity analysis revealed heterogeneity or horizontal pleiotropy.When gut microbiota were used as exposure and osteonecrosis due to drugs as the outcome,Mendelian randomization analysis found that seven bacterial traits were positively correlated to osteonecrosis due to drugs,nine bacterial traits were negatively related to osteonecrosis due to drugs.When osteonecrosis due to drugs were used as exposure and gut microbiota as the outcome,reverse Mendelian randomization analysis found a negative correlated relationship with five bacterial traits and a positive causal relationship with one bacterial trait.By changing the diversity and composition of gut microbiota,it is expected to improve the incidence and prognosis of osteonecrosis due to drugs,providing new ideas for the study of orthopedic diseases.

Objective:To investigate the application value of fecal Syndecan-2 (SDC2) gene methylated SDC2 (m SDC2) detection in colorectal cancer (CRC) screening among urban residents in Guangzhou City. Methods:A cross-sectional study was conducted in Shitan Town, Zengcheng District, Guangzhou City from July to December 2022. A community-based screening program for CRC was conducted among residents aged 40-74 years old. m SDC2 detection was employed in the participants, and those with positive results should be recommended to receive colonoscopy examination. The positive rate of m SDC2 detection, colonoscopy compliance rate, detection rate of intestinal lesions and clinicopathological characteristics were observed. The relationship between cycle threshold (CT) value of m SDC2 and intestinal lesions was explored. Further, the cost-effectiveness of screening was evaluated. Results:A total of 8 189 fecal samples were collected from 8 877 participants with the recovery rate of 92.25%. 8 048 qualified samples were enrolled in this study, consisted of 3 182 males (39.54%) and 4 866 females (60.46%), with the average age of 56 years old (40-74 years). The positive rate of m SDC2 detection was 7.99% (643/8 048), and the compliance rate of colonoscopy was 73.10% (470/643). 20 cases (4.25%) of colorectal cancer, 109 cases (23.19%) of advanced adenoma, 145 cases (30.85%) of non-advanced adenoma, 79 cases (16.81%) of polyps were detected. The detection rate of intestinal lesions was 75.11% and indicated significant differences in gender and age. 20 CRCs included 15 of stage 0-I, 4 of stage Ⅱ-Ⅲ and 1 of unknown stage. The CT value of m SDC2 was negatively correlated with the proportion of advanced colorectal neoplasms ( χ2=16.063, P<0.001). The total cost of the screening was 4.339 5 million yuan, the screening benefit was 28.506 2 million yuan, and the benefit-cost ratio was 6.57. Conclusion:The CRC screening strategy of fecal m SDC2 detection combined with colonoscopy has high colonoscopy compliance and detection rate of intestinal lesions, which is conducive to the detection of early CRCs, and has good cost-effectiveness. This study suggests that this method may be applied to the general CRC screening in China and contribute to the prevention of CRC. The CT value of m SDC2 may have a certain suggestion on the malignant degree of intestinal tumors.