BACKGROUND Early renal artery thrombosis after kidney transplantation is rare but often leads to graft loss.Prompt diagnosis and intervention are essential,particularly in patients with inherited thrombophilias such a...BACKGROUND Early renal artery thrombosis after kidney transplantation is rare but often leads to graft loss.Prompt diagnosis and intervention are essential,particularly in patients with inherited thrombophilias such as factor V Leiden(FVL)mutation.CASE SUMMARY A kidney transplant recipient with FVL mutation developed an acute transplant renal artery thrombosis.The immediate post-operative Doppler ultrasonography revealed thrombosis of the main and inferior polar renal arteries.Emergent thrombectomy and separate arterial re-anastomoses were performed after cold perfusion with heparinized saline and vasodilator solution.Reperfusion was successful with immediate urine output and gradual improvement in renal function.The patient was discharged on direct oral anticoagulation therapy.CONCLUSION Early detection and surgical intervention can preserve graft function in posttransplant renal artery thrombosis even in patients at high risk.展开更多
BACKGROUND Liver transplantation(LT)is the preferred treatment for end-stage liver diseases.Early allograft failure(EAF)can result in death or retransplantation.One of the key factors predicting EAF is the degree of g...BACKGROUND Liver transplantation(LT)is the preferred treatment for end-stage liver diseases.Early allograft failure(EAF)can result in death or retransplantation.One of the key factors predicting EAF is the degree of graft injury,which is typically assessed by elevated alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels.Aminotransferase levels exceeding 5000 U/L within 48 hours of LT are indicative of poor short-term graft survival.AIM To investigate outcomes in liver transplant recipients with peak aminotransferase levels exceeding 5000 U/L and to identify predictors of EAF.METHODS Adult patients who underwent LT from a deceased(brain-dead)donor between 2011 and 2024 at Hospital de Clínicas de Porto Alegre were screened.Patients with peak AST or ALT levels>5000 U/L post-LT were included,excluding those with vascular thrombosis.EAF was defined as death or retransplantation within 90 days.A receiver operating characteristic curve were generated for each EAF predictor to determine the area under the curve(AUC).Sensitivity,specificity,negative predictive value,and positive predictive value were calculated for each predictor’s best cutoff,as defined by the Youden Index.Survival curves were plotted using the Kaplan-Meier method.RESULTS Between 2011 and 2024,341 patients underwent LT.Of these,29(8.5%)patients had AST and/or ALT levels exceeding 5000 U/L within the first 48 hours post-LT.Four patients were excluded due to vascular thrombosis,resulting in a study cohort of 25 patients.EAF were also observed in 11 patients.One-year and five-year graft survival rates were 51.7%and 42.6%,respectively.For patients without EAF,one-year and five-year graft survivals were 92.3%and 76.2%,respectively.The key predictors of EAF included serum factor V and arterial lactate levels on postoperative day(POD)1,with AUCs of 0.936 and 0.919,respectively.The optimal cutoff for EAF prediction were 26.2%for serum factor V and 9 mmol/L for arterial lactate.CONCLUSION Aminotransferase levels>5000 U/L were associated with high EAF risk.However,favorable graft function indicators on POD 1 were associated with long-term survival comparable to that of general LT recipients.Serum factor V and arterial lactate levels emerged as valuable prognostic markers.展开更多
Graft failure is the worst complication of organ transplantation.Considering liver transplantation,aminotransferase levels have been demonstrated to be a precursor of severe graft failure,in particular when they excee...Graft failure is the worst complication of organ transplantation.Considering liver transplantation,aminotransferase levels have been demonstrated to be a precursor of severe graft failure,in particular when they exceed 5000 U/L in the immediate post-operation.However,some studies show that the outcome of the transplanted liver is not determinable by biochemistry alone.One of the most relevant studies is the one published by Lazzarotto-da-Silva et al.In this retrospective study,341 transplanted livers are considered.In 25 cases,this severe biochemical insult has been reported.But despite this event,more than half had significant long-term survival.One of the most valuable elements that emerge from this work is the identification of two easily measurable markers-serum factor V and arterial lactate,which independently can indicate the graft's 90-day outcome.This finding provides a key clinical picture to distinguish patients who are most likely to recover from those destined for irreversible graft loss.In a time where organs are increasingly scarce,these discoveries could facilitate more prudent use of retransplantation,improving both individual outcomes and the overall distribution of resources.This study contributes significantly to a deeper understanding of early graft injury,although larger prospective studies are needed.It highlights the need to move beyond singular value thresholds and toward integrated,evidence-based decision making during the crucial early posttransplant period.This study not only captures risk but also provides a tool for intervention.展开更多
A 79-year-old man was hospitalized because of worsening upper abdominal pain which started two days before admission and was continuously present. His personal and family historywas uneventful, he did not smoke and de...A 79-year-old man was hospitalized because of worsening upper abdominal pain which started two days before admission and was continuously present. His personal and family historywas uneventful, he did not smoke and denied toxic habits or using any medications, including overthe-counter medications, herbal remedies or any vitamin supplements.展开更多
Objective:To examine the perioperative impact of factor V Leiden mutation on thromboembolic events'risk in radical prostatectomy(RP)patients.With an incidence of about 5%,factor V Leiden mutation is the most commo...Objective:To examine the perioperative impact of factor V Leiden mutation on thromboembolic events'risk in radical prostatectomy(RP)patients.With an incidence of about 5%,factor V Leiden mutation is the most common hereditary hypercoagulability among Caucasians and rarer in Asia.The increased risk of thromboembolic events is three-to seven-fold in heterozygous and to 80-fold in homozygous patients.Methods:Within our prospectively collected database,we analysed 33006 prostate cancer patients treated with RP between December 2001 and December 2020.Of those,patients with factor V Leiden mutation were identified.All patients received individualised recommendation of haemostaseologists for perioperative anticoagulation.Thromboembolic complications(deep vein thrombosis and pulmonary embolism)were assessed during hospital stay,as well as according to patient reported outcomes within the first 3 months after RP.Results:Overall,85(0.3%)patients with known factor V Leiden mutation were identified.Median age was 65(interquartile range:61-68)years.There was at least one thrombosis in 53(62.4%)patients and 31(36.5%)patients had at least one embolic event in their medical history before RP.Within all 85 patients with factor V Leiden mutation,we experienced no thromboembolic complications within the first 3 months after surgery.Conclusion:In our cohort of patients with factor V Leiden mutation,no thromboembolic events were observed after RP with an individualised perioperative coagulation management concept.This may reassure patients with this hereditary condition who are counselled for RP.展开更多
AIM： To analyze the prevalence of the two commonest thrombophilic mutations, factor V Leiden and prothrombin G20210A, in patients with gastric cancer. METHODS： One hundred and twenty-one patients with primary gastri...AIM： To analyze the prevalence of the two commonest thrombophilic mutations, factor V Leiden and prothrombin G20210A, in patients with gastric cancer. METHODS： One hundred and twenty-one patients with primary gastric carcinoma and 130 healthy subjects, comparable for age and sex, were investigated. Factor V Leiden was detected by using polymerase chain reaction and restriction enzyme digestion, and prothrombin G20210A gene mutation by allele-specific PCR. RESULTS： Among the 121 cancer patients, factor V Leiden was found in 4 cases （GA genotype： 3.3%） and prothrombin G20210A in 10 cases （GA genotype： 8.3%）. Of the 130 control subjects, factor V Leiden was detected in 6 cases （GA genotype： 4.6%） and prothrombin G20210A in 8 cases （GA genotype： 6.1%）. No double heterozygous carriers of both mutations were found in either group. The prevalence of both factor V Leiden and prothrombin G20210A variant was not statistically different between the cancer patients and the healthy subjects. CONCLUSION： Our study suggests that, in gastric cancer, the risk factors of thrombophilic cancer state are on acquired rather than on a genetic basis and that prothrombin G20210A does not seem to be a cofactor in gastric cancer pathogenesis.展开更多
Human coagulation Factor V（FV）, together with Factor Xa, assembles to prothrombinase complex on activated cell surface, which converts prothrombin into thrombin, leading to fibrin deposition. The C2 domain of FV is ...Human coagulation Factor V（FV）, together with Factor Xa, assembles to prothrombinase complex on activated cell surface, which converts prothrombin into thrombin, leading to fibrin deposition. The C2 domain of FV is believed to be a primary anchor for the assembly of pro- thrombinase on the cell surface, and was proposed as a target to intervene with pathological thrombotic events. We report here the crystal structure of the C2 domain of FV fused to maltose-binding protein（MBP）. The fusion tag of MBP is critical to generate the crystal for this study. There is no strong interaction between MBP and FVC2. The overall structure of FVC2 is similar to the previous FVC2 structures, suggesting the MBP fusion does not perturb the molecular structure of FVC2. This crystal form of FVC2 can be used for future study of molecular interaction between FVC2 and its inhibitors.展开更多
In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic indiv...In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic individuals. Diabetes is a complex and multifactorial disease involving genetic components. With the aim of preventing complications and contributing to an efficient management of diabetes, we investigated genes likely to lead to a risk of thrombosis, in particular the C677T of MTHFR, G20210A of prothrombin, and R506Q of factor V Leiden in type 2 diabetics in Abidjan receiving ambulatory care. A descriptive cross-sectional study was carried out on consenting type 2 diabetic patients. Mutation detection was carried out using the PCR-RFLP method employing restriction enzymes. Hemostasis tests (fibrinogen, D-dimers, fibrin monomers, and von Willebrand factor) were performed using citrate tubes on the Stage? Star Max automated system. Plasminogen activator inhibitor was assayed by ELISA method, and biochemical parameters were determined using the COBAS C311. The study population consisted of 45 diabetic patients, 51.1% of whom presented vascular complications, mainly neuropathy. Disturbances in hemostasis parameters were observed, with 15.5% of patients showing an increase in fibrin monomers. Mutation analysis revealed an absence of factor V mutation (factor V Leiden) and of G20210A mutation of the prothrombin gene. However, 15.6% of subjects had a heterozygous C677T mutation of MTHFR, with 57% of them being anemic. The exploration of biological and genetic factors associated with thrombotic risk is of significant interest in the optimal management of African type 2 diabetics.展开更多
Thromboembolism is an important complication in children undergoing therapy for ALL as it has the potential to impact adversely on both their survival and quality of life. The incidence of thrombosis in children with ...Thromboembolism is an important complication in children undergoing therapy for ALL as it has the potential to impact adversely on both their survival and quality of life. The incidence of thrombosis in children with ALL varies between 1.1% and 36.7% and the actual mean is 3.2%. The aim of our study is to review the available reported data on the effect of FVL on thrombotic risk in pediatric patients with acute leukemia.展开更多
Background: As life expectancy of HIV-infected patients increases with use of highly active antiretroviral therapy (HAART), protean haematologic manifestation including decreased activity of natural anticoagulants suc...Background: As life expectancy of HIV-infected patients increases with use of highly active antiretroviral therapy (HAART), protean haematologic manifestation including decreased activity of natural anticoagulants such as protein C may occur in the absence of genetic risk factors. Based on this preposition, we assessed the plasma level of protein C, and prevalence of factor V Leiden mutation among HIV-infected individuals. Our cohort consisted of 499 HIV-infected patients, of which 250 had AIDS, while 249 were either asymptomatic or had minor mucocutaneous infection consistent with WHO clinical stages I and II without features of AIDS. We also evaluated 251 healthy, HIV-negative subjects as controls. All participants were tested for plasma protein C levels and factor V Leiden (FVL) mutation (Arg 506 Gln) by automation and amplification created restriction enzyme site (ACRES) polymerase chain reaction, respectively. The prevalence of reduced protein C plasma levels among HIV positive patients was 20%;it was more prevalent among those that had AIDS compared with those without features of AIDS, but within WHO clinical stage I and II, (93.3% vs 6.7%) respectively. None of the control patients had either reduced protein C nor FVL mutation. All participants that demonstrated reduced protein C plasma levels demonstrated normal FVL genotype (1691G/G). Conclusion: Decreased protein C plasma levels can occur in HIV-infected patients in the absence of factor V Leiden mutation. The risk increases with severity of the disease. Deranged protein C plasma level increases the risk of hypercoagulable state in patients with advanced HIV disease;it should be considered among the causes of thrombo embolism in this group of patients.展开更多
AIM: To evaluate the effect of resistance to activated protein C (aPCR), the most common known inherited thrombophilic disorder, on the risk of intestinal operation of fi brostenosis in patients with Crohn’s disease ...AIM: To evaluate the effect of resistance to activated protein C (aPCR), the most common known inherited thrombophilic disorder, on the risk of intestinal operation of fi brostenosis in patients with Crohn’s disease (CD). METHODS: In a previous study, we assessed the prevalence of aPCR in CD. In a retrospective case- controlled study, 8 of these CD patients with aPCR were now compared with 24 CD patients without aPCR, matched by gender, age at diagnosis and duration of disease in a 1:3 fashion. The primary end point was the occurrence of an intestinal CD-related operation with evidence of fibrostenosis in the bowel resection specimen. RESULTS: The Kaplan-Meier analysis revealed that patients with aPCR had a lower probability of remaining free of operation with f ibrostenosis than patients without aPCR (P = 0.0372; exact log-rank test) resulting in a signifi cantly shorter median time interval from diagnosis of CD to the fi rst operation with fi brostenosis (32 vs 160 mo). At 10 years, the likelihood of remaining free of operation with fi brostenosis was 25% for patients with aPCR and 57.8% for patients without aPCR. CONCLUSION: CD patients with aPCR are at higher risk to undergo intestinal operation of fi brostenosis than those without aPCR. This supports our hypothesis of aPCR being a possible risk factor for fi brostenosis in CD.展开更多
Nerve growth factor(NGF) is a powerful trophic factor that provides essential support for the survival and differentiation of sympathetic and sensory neurons during development. However, NGF also activates nociceptors...Nerve growth factor(NGF) is a powerful trophic factor that provides essential support for the survival and differentiation of sympathetic and sensory neurons during development. However, NGF also activates nociceptors contributing significantly to inflammatory pain and neuropathic pain after tissue injury. As such anti-NGF based therapies represent a promising strategy for pain management. Because of dose-dependent serious side effects such as back pain, injection site hyperalgesia, clinical trials of using NGF to treat various disorders such as diabetic neuropathies, chemotherapy-induced and human immunodeficiency virus-associated peripheral neuropathies were all discontinued. Thus far, worldwide clinical applications of NGF in treating patients are very limited except in China. Hereditary sensory autonomic neuropathy type V(HSAN V) is an extremely rare disease. Genetic analyses have revealed that HSAN V is associated with autosomal recessive mutations in NGF. One of the mutations occurred at the 100^(th) position of mature NGF resulting in a change of residue from arginine to tryptophan(R100W). Although those HSAN V patients associated with the NGF^(R100W) mutation suffer from severe loss of deep pain, bone fractures and joint destruction, interestingly patients with the NGF^(R100W) mutation do not show apparent cognitive deficits, suggesting important trophic support function is preserved. We believe that NGF^(R100W) provides an ideal tool to uncouple the two important functions of NGF: trophic versus nociceptive. Studies from investigators including ourselves have indeed confirmed in animal testing that the NGF^(R100W) no longer induced pain. More importantly, the trophic function seemed to be largely preserved in NGF harboring the R100W mutation. On the mechanistic level, we found that the NGF^(R100W) mutation was capable of binding to and signaling through the tyrosine receptor kinase A receptor. But its ability to bind to and activate the 75 kDa neurotrophic factor was significantly diminished. The significance of these findings is at least two folds: 1) the NGF^(R100W) mutation can be used as an alternative to the wildtype NGF to treat human conditions without eliciting pain; and 2) the 75 kDa neurotrophic factor may serve as a novel target for pain management. We will discuss all the details in this mini-review.展开更多
Based on Zak＇s stress function, the eigen-equation of stress singularity ofbi-materials with a V-notch was obtained. A new definition of stress intensity factor for a perpendicular interfacial V-notch of bi-material ...Based on Zak＇s stress function, the eigen-equation of stress singularity ofbi-materials with a V-notch was obtained. A new definition of stress intensity factor for a perpendicular interfacial V-notch of bi-material was put forward. The effects of shear modulus and Poisson＇s ratio of the matrix material and attaching material on eigen-values were analyzed. A generalized expression for calculating/（i of the perpendicular V-notch of bi-materials was obtained by means of stress extrapolation. Effects of notch depth, notch angle and Poisson＇s ratio of materials on the singular stress field near the tip of the V-notch were analyzed systematically with numerical simulations. As an example, a finite plate with double edge notches under uniaxial uniform tension was calculated by the method presented and the influence of the notch angle and Poisson＇s ratio on the stress singularity near the tip of notch was obtained.展开更多
BACKGROUND Epidermal growth factor receptor(EGFR)tyrosine-kinase inhibitors are widely used for the treatment of non-small-cell lung cancer with EGFR mutations.However,patients with rare,even compound EGFR mutations h...BACKGROUND Epidermal growth factor receptor(EGFR)tyrosine-kinase inhibitors are widely used for the treatment of non-small-cell lung cancer with EGFR mutations.However,patients with rare,even compound EGFR mutations have different responses to EGFR-tyrosine-kinase inhibitors,which bring uncertainty to clinical treatment.CASE SUMMARY A 45-year-old female patient presented with a 3-mo history of cough and white sputum without chest pain.Chest computed tomography revealed lung spaceoccupying lesions and multiple lymphadenectasis.Bronchoscopy and pathology suggested lung adenocarcinoma.Compound variation of EGFR gene(exon 21 L858 R/V834 L)was detected in both tissue and circulating tumor deoxyribonucleic acid samples.As a result of next-generation sequencing and her family’s wishes,the patient was given oral treatment with icotinib hydrochloride(125 mg/d,tid)from March 21,2019 and has achieved stable disease for the last 1 year.CONCLUSION Non-small cell lung adenocarcinoma with EGFR L858 R/V834 L was treated successfully with icotinib,and it may be a new medication treatment option.展开更多
The relationship between fracture toughness VGC and critical void growth RC/RO was studied for ten kinds of Steel. The macroscopic fracture toughness VGC was determined by using notched tensile specimens. and the micr...The relationship between fracture toughness VGC and critical void growth RC/RO was studied for ten kinds of Steel. The macroscopic fracture toughness VGC was determined by using notched tensile specimens. and the microscopic parameters of critical void growth ratio RC/RO were quantitatively measured under SEM. Then, the coefhcient C in the relation VGC = C In(RC/RO) proposed in author's past work was specifically explored. The correlation of C with tensile proderty parameter φ=σyδ/(Eφn) was presented for the Steel investigated, and the effects of low temperature on C were also discussed. Results show that the coefficient C is linearly related to the parameter and insensitive to low temperature.展开更多
In order to improve the bending load-carrying capacity （BLCC） of undermatched butt joint under three-point bending load, the influence of joint geometric parameters on stress concentration factors （SCF） at the wel...In order to improve the bending load-carrying capacity （BLCC） of undermatched butt joint under three-point bending load, the influence of joint geometric parameters on stress concentration factors （SCF） at the weld bottom center and the weld toe of uudermatched butt joint with single V-groove are studied respectively based on the finite element method in this paper. Results show that the reinforcement height and the cover pass width play decisive role in the BLCC for undermatched butt joint. BLCC of undermatched butt joint can be improved by choosing the appropriate joint geometric parameters.展开更多
In order to make the fracture cross-section of rock smooth in controlled cutting-blast, generally, two V-shape-notches on the inner wall of a shot hole are notched in symmetry along the design direction. A V-shape not...In order to make the fracture cross-section of rock smooth in controlled cutting-blast, generally, two V-shape-notches on the inner wall of a shot hole are notched in symmetry along the design direction. A V-shape notch approximately be considered as V-shape-fracture under certain condition. This paper gave the complex stress function of preformed V-shape-fracture under a blasting load. The stress field and displacement field at the tip of a preformed V-shape-fracture were derived with Westergaard's method, hence its stressintensity factor was obtained. To verify the derived results, blasting tests were made with concrete samples of 400mm×400mm×300mm, and all having, in the center, a drilled hole of 25mm in diameter and 200mm in height. The test result showed that the formulas derived are correct and effective.展开更多
文摘BACKGROUND Early renal artery thrombosis after kidney transplantation is rare but often leads to graft loss.Prompt diagnosis and intervention are essential,particularly in patients with inherited thrombophilias such as factor V Leiden(FVL)mutation.CASE SUMMARY A kidney transplant recipient with FVL mutation developed an acute transplant renal artery thrombosis.The immediate post-operative Doppler ultrasonography revealed thrombosis of the main and inferior polar renal arteries.Emergent thrombectomy and separate arterial re-anastomoses were performed after cold perfusion with heparinized saline and vasodilator solution.Reperfusion was successful with immediate urine output and gradual improvement in renal function.The patient was discharged on direct oral anticoagulation therapy.CONCLUSION Early detection and surgical intervention can preserve graft function in posttransplant renal artery thrombosis even in patients at high risk.
基金Supported by Financiamento e IncentivoàPesquisa of Hospital de Clínicas de Porto Alegre,No.170271.
文摘BACKGROUND Liver transplantation(LT)is the preferred treatment for end-stage liver diseases.Early allograft failure(EAF)can result in death or retransplantation.One of the key factors predicting EAF is the degree of graft injury,which is typically assessed by elevated alanine aminotransferase(ALT)and aspartate aminotransferase(AST)levels.Aminotransferase levels exceeding 5000 U/L within 48 hours of LT are indicative of poor short-term graft survival.AIM To investigate outcomes in liver transplant recipients with peak aminotransferase levels exceeding 5000 U/L and to identify predictors of EAF.METHODS Adult patients who underwent LT from a deceased(brain-dead)donor between 2011 and 2024 at Hospital de Clínicas de Porto Alegre were screened.Patients with peak AST or ALT levels>5000 U/L post-LT were included,excluding those with vascular thrombosis.EAF was defined as death or retransplantation within 90 days.A receiver operating characteristic curve were generated for each EAF predictor to determine the area under the curve(AUC).Sensitivity,specificity,negative predictive value,and positive predictive value were calculated for each predictor’s best cutoff,as defined by the Youden Index.Survival curves were plotted using the Kaplan-Meier method.RESULTS Between 2011 and 2024,341 patients underwent LT.Of these,29(8.5%)patients had AST and/or ALT levels exceeding 5000 U/L within the first 48 hours post-LT.Four patients were excluded due to vascular thrombosis,resulting in a study cohort of 25 patients.EAF were also observed in 11 patients.One-year and five-year graft survival rates were 51.7%and 42.6%,respectively.For patients without EAF,one-year and five-year graft survivals were 92.3%and 76.2%,respectively.The key predictors of EAF included serum factor V and arterial lactate levels on postoperative day(POD)1,with AUCs of 0.936 and 0.919,respectively.The optimal cutoff for EAF prediction were 26.2%for serum factor V and 9 mmol/L for arterial lactate.CONCLUSION Aminotransferase levels>5000 U/L were associated with high EAF risk.However,favorable graft function indicators on POD 1 were associated with long-term survival comparable to that of general LT recipients.Serum factor V and arterial lactate levels emerged as valuable prognostic markers.
文摘Graft failure is the worst complication of organ transplantation.Considering liver transplantation,aminotransferase levels have been demonstrated to be a precursor of severe graft failure,in particular when they exceed 5000 U/L in the immediate post-operation.However,some studies show that the outcome of the transplanted liver is not determinable by biochemistry alone.One of the most relevant studies is the one published by Lazzarotto-da-Silva et al.In this retrospective study,341 transplanted livers are considered.In 25 cases,this severe biochemical insult has been reported.But despite this event,more than half had significant long-term survival.One of the most valuable elements that emerge from this work is the identification of two easily measurable markers-serum factor V and arterial lactate,which independently can indicate the graft's 90-day outcome.This finding provides a key clinical picture to distinguish patients who are most likely to recover from those destined for irreversible graft loss.In a time where organs are increasingly scarce,these discoveries could facilitate more prudent use of retransplantation,improving both individual outcomes and the overall distribution of resources.This study contributes significantly to a deeper understanding of early graft injury,although larger prospective studies are needed.It highlights the need to move beyond singular value thresholds and toward integrated,evidence-based decision making during the crucial early posttransplant period.This study not only captures risk but also provides a tool for intervention.
文摘A 79-year-old man was hospitalized because of worsening upper abdominal pain which started two days before admission and was continuously present. His personal and family historywas uneventful, he did not smoke and denied toxic habits or using any medications, including overthe-counter medications, herbal remedies or any vitamin supplements.
文摘Objective:To examine the perioperative impact of factor V Leiden mutation on thromboembolic events'risk in radical prostatectomy(RP)patients.With an incidence of about 5%,factor V Leiden mutation is the most common hereditary hypercoagulability among Caucasians and rarer in Asia.The increased risk of thromboembolic events is three-to seven-fold in heterozygous and to 80-fold in homozygous patients.Methods:Within our prospectively collected database,we analysed 33006 prostate cancer patients treated with RP between December 2001 and December 2020.Of those,patients with factor V Leiden mutation were identified.All patients received individualised recommendation of haemostaseologists for perioperative anticoagulation.Thromboembolic complications(deep vein thrombosis and pulmonary embolism)were assessed during hospital stay,as well as according to patient reported outcomes within the first 3 months after RP.Results:Overall,85(0.3%)patients with known factor V Leiden mutation were identified.Median age was 65(interquartile range:61-68)years.There was at least one thrombosis in 53(62.4%)patients and 31(36.5%)patients had at least one embolic event in their medical history before RP.Within all 85 patients with factor V Leiden mutation,we experienced no thromboembolic complications within the first 3 months after surgery.Conclusion:In our cohort of patients with factor V Leiden mutation,no thromboembolic events were observed after RP with an individualised perioperative coagulation management concept.This may reassure patients with this hereditary condition who are counselled for RP.
基金Supported by a Research Grant from the University of Siena (PAR)
文摘AIM： To analyze the prevalence of the two commonest thrombophilic mutations, factor V Leiden and prothrombin G20210A, in patients with gastric cancer. METHODS： One hundred and twenty-one patients with primary gastric carcinoma and 130 healthy subjects, comparable for age and sex, were investigated. Factor V Leiden was detected by using polymerase chain reaction and restriction enzyme digestion, and prothrombin G20210A gene mutation by allele-specific PCR. RESULTS： Among the 121 cancer patients, factor V Leiden was found in 4 cases （GA genotype： 3.3%） and prothrombin G20210A in 10 cases （GA genotype： 8.3%）. Of the 130 control subjects, factor V Leiden was detected in 6 cases （GA genotype： 4.6%） and prothrombin G20210A in 8 cases （GA genotype： 6.1%）. No double heterozygous carriers of both mutations were found in either group. The prevalence of both factor V Leiden and prothrombin G20210A variant was not statistically different between the cancer patients and the healthy subjects. CONCLUSION： Our study suggests that, in gastric cancer, the risk factors of thrombophilic cancer state are on acquired rather than on a genetic basis and that prothrombin G20210A does not seem to be a cofactor in gastric cancer pathogenesis.
基金Supported by the National Natural Science Foundation of China(31161130356)
文摘Human coagulation Factor V（FV）, together with Factor Xa, assembles to prothrombinase complex on activated cell surface, which converts prothrombin into thrombin, leading to fibrin deposition. The C2 domain of FV is believed to be a primary anchor for the assembly of pro- thrombinase on the cell surface, and was proposed as a target to intervene with pathological thrombotic events. We report here the crystal structure of the C2 domain of FV fused to maltose-binding protein（MBP）. The fusion tag of MBP is critical to generate the crystal for this study. There is no strong interaction between MBP and FVC2. The overall structure of FVC2 is similar to the previous FVC2 structures, suggesting the MBP fusion does not perturb the molecular structure of FVC2. This crystal form of FVC2 can be used for future study of molecular interaction between FVC2 and its inhibitors.
文摘In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic individuals. Diabetes is a complex and multifactorial disease involving genetic components. With the aim of preventing complications and contributing to an efficient management of diabetes, we investigated genes likely to lead to a risk of thrombosis, in particular the C677T of MTHFR, G20210A of prothrombin, and R506Q of factor V Leiden in type 2 diabetics in Abidjan receiving ambulatory care. A descriptive cross-sectional study was carried out on consenting type 2 diabetic patients. Mutation detection was carried out using the PCR-RFLP method employing restriction enzymes. Hemostasis tests (fibrinogen, D-dimers, fibrin monomers, and von Willebrand factor) were performed using citrate tubes on the Stage? Star Max automated system. Plasminogen activator inhibitor was assayed by ELISA method, and biochemical parameters were determined using the COBAS C311. The study population consisted of 45 diabetic patients, 51.1% of whom presented vascular complications, mainly neuropathy. Disturbances in hemostasis parameters were observed, with 15.5% of patients showing an increase in fibrin monomers. Mutation analysis revealed an absence of factor V mutation (factor V Leiden) and of G20210A mutation of the prothrombin gene. However, 15.6% of subjects had a heterozygous C677T mutation of MTHFR, with 57% of them being anemic. The exploration of biological and genetic factors associated with thrombotic risk is of significant interest in the optimal management of African type 2 diabetics.
文摘Thromboembolism is an important complication in children undergoing therapy for ALL as it has the potential to impact adversely on both their survival and quality of life. The incidence of thrombosis in children with ALL varies between 1.1% and 36.7% and the actual mean is 3.2%. The aim of our study is to review the available reported data on the effect of FVL on thrombotic risk in pediatric patients with acute leukemia.
文摘Background: As life expectancy of HIV-infected patients increases with use of highly active antiretroviral therapy (HAART), protean haematologic manifestation including decreased activity of natural anticoagulants such as protein C may occur in the absence of genetic risk factors. Based on this preposition, we assessed the plasma level of protein C, and prevalence of factor V Leiden mutation among HIV-infected individuals. Our cohort consisted of 499 HIV-infected patients, of which 250 had AIDS, while 249 were either asymptomatic or had minor mucocutaneous infection consistent with WHO clinical stages I and II without features of AIDS. We also evaluated 251 healthy, HIV-negative subjects as controls. All participants were tested for plasma protein C levels and factor V Leiden (FVL) mutation (Arg 506 Gln) by automation and amplification created restriction enzyme site (ACRES) polymerase chain reaction, respectively. The prevalence of reduced protein C plasma levels among HIV positive patients was 20%;it was more prevalent among those that had AIDS compared with those without features of AIDS, but within WHO clinical stage I and II, (93.3% vs 6.7%) respectively. None of the control patients had either reduced protein C nor FVL mutation. All participants that demonstrated reduced protein C plasma levels demonstrated normal FVL genotype (1691G/G). Conclusion: Decreased protein C plasma levels can occur in HIV-infected patients in the absence of factor V Leiden mutation. The risk increases with severity of the disease. Deranged protein C plasma level increases the risk of hypercoagulable state in patients with advanced HIV disease;it should be considered among the causes of thrombo embolism in this group of patients.
文摘AIM: To evaluate the effect of resistance to activated protein C (aPCR), the most common known inherited thrombophilic disorder, on the risk of intestinal operation of fi brostenosis in patients with Crohn’s disease (CD). METHODS: In a previous study, we assessed the prevalence of aPCR in CD. In a retrospective case- controlled study, 8 of these CD patients with aPCR were now compared with 24 CD patients without aPCR, matched by gender, age at diagnosis and duration of disease in a 1:3 fashion. The primary end point was the occurrence of an intestinal CD-related operation with evidence of fibrostenosis in the bowel resection specimen. RESULTS: The Kaplan-Meier analysis revealed that patients with aPCR had a lower probability of remaining free of operation with f ibrostenosis than patients without aPCR (P = 0.0372; exact log-rank test) resulting in a signifi cantly shorter median time interval from diagnosis of CD to the fi rst operation with fi brostenosis (32 vs 160 mo). At 10 years, the likelihood of remaining free of operation with fi brostenosis was 25% for patients with aPCR and 57.8% for patients without aPCR. CONCLUSION: CD patients with aPCR are at higher risk to undergo intestinal operation of fi brostenosis than those without aPCR. This supports our hypothesis of aPCR being a possible risk factor for fi brostenosis in CD.
文摘Nerve growth factor(NGF) is a powerful trophic factor that provides essential support for the survival and differentiation of sympathetic and sensory neurons during development. However, NGF also activates nociceptors contributing significantly to inflammatory pain and neuropathic pain after tissue injury. As such anti-NGF based therapies represent a promising strategy for pain management. Because of dose-dependent serious side effects such as back pain, injection site hyperalgesia, clinical trials of using NGF to treat various disorders such as diabetic neuropathies, chemotherapy-induced and human immunodeficiency virus-associated peripheral neuropathies were all discontinued. Thus far, worldwide clinical applications of NGF in treating patients are very limited except in China. Hereditary sensory autonomic neuropathy type V(HSAN V) is an extremely rare disease. Genetic analyses have revealed that HSAN V is associated with autosomal recessive mutations in NGF. One of the mutations occurred at the 100^(th) position of mature NGF resulting in a change of residue from arginine to tryptophan(R100W). Although those HSAN V patients associated with the NGF^(R100W) mutation suffer from severe loss of deep pain, bone fractures and joint destruction, interestingly patients with the NGF^(R100W) mutation do not show apparent cognitive deficits, suggesting important trophic support function is preserved. We believe that NGF^(R100W) provides an ideal tool to uncouple the two important functions of NGF: trophic versus nociceptive. Studies from investigators including ourselves have indeed confirmed in animal testing that the NGF^(R100W) no longer induced pain. More importantly, the trophic function seemed to be largely preserved in NGF harboring the R100W mutation. On the mechanistic level, we found that the NGF^(R100W) mutation was capable of binding to and signaling through the tyrosine receptor kinase A receptor. But its ability to bind to and activate the 75 kDa neurotrophic factor was significantly diminished. The significance of these findings is at least two folds: 1) the NGF^(R100W) mutation can be used as an alternative to the wildtype NGF to treat human conditions without eliciting pain; and 2) the 75 kDa neurotrophic factor may serve as a novel target for pain management. We will discuss all the details in this mini-review.
基金supported by the Ministry of Education of China(No.208152)Gansu Natural Science Foundation(No.3ZS061-A52-47).
文摘Based on Zak＇s stress function, the eigen-equation of stress singularity ofbi-materials with a V-notch was obtained. A new definition of stress intensity factor for a perpendicular interfacial V-notch of bi-material was put forward. The effects of shear modulus and Poisson＇s ratio of the matrix material and attaching material on eigen-values were analyzed. A generalized expression for calculating/（i of the perpendicular V-notch of bi-materials was obtained by means of stress extrapolation. Effects of notch depth, notch angle and Poisson＇s ratio of materials on the singular stress field near the tip of the V-notch were analyzed systematically with numerical simulations. As an example, a finite plate with double edge notches under uniaxial uniform tension was calculated by the method presented and the influence of the notch angle and Poisson＇s ratio on the stress singularity near the tip of notch was obtained.
文摘BACKGROUND Epidermal growth factor receptor(EGFR)tyrosine-kinase inhibitors are widely used for the treatment of non-small-cell lung cancer with EGFR mutations.However,patients with rare,even compound EGFR mutations have different responses to EGFR-tyrosine-kinase inhibitors,which bring uncertainty to clinical treatment.CASE SUMMARY A 45-year-old female patient presented with a 3-mo history of cough and white sputum without chest pain.Chest computed tomography revealed lung spaceoccupying lesions and multiple lymphadenectasis.Bronchoscopy and pathology suggested lung adenocarcinoma.Compound variation of EGFR gene(exon 21 L858 R/V834 L)was detected in both tissue and circulating tumor deoxyribonucleic acid samples.As a result of next-generation sequencing and her family’s wishes,the patient was given oral treatment with icotinib hydrochloride(125 mg/d,tid)from March 21,2019 and has achieved stable disease for the last 1 year.CONCLUSION Non-small cell lung adenocarcinoma with EGFR L858 R/V834 L was treated successfully with icotinib,and it may be a new medication treatment option.
文摘The relationship between fracture toughness VGC and critical void growth RC/RO was studied for ten kinds of Steel. The macroscopic fracture toughness VGC was determined by using notched tensile specimens. and the microscopic parameters of critical void growth ratio RC/RO were quantitatively measured under SEM. Then, the coefhcient C in the relation VGC = C In(RC/RO) proposed in author's past work was specifically explored. The correlation of C with tensile proderty parameter φ=σyδ/(Eφn) was presented for the Steel investigated, and the effects of low temperature on C were also discussed. Results show that the coefficient C is linearly related to the parameter and insensitive to low temperature.
基金The authors are grateful to be financially supported by Projects of Natural Science Foundation of Heilongjiang Province （No. E201458） , State Key Lab of Advanced Welding and Joining, Har- bin Institute of Technology （AWJ-M13-14） and Hei longjiang Prov- ince Department of Education （12541679）.
文摘In order to improve the bending load-carrying capacity （BLCC） of undermatched butt joint under three-point bending load, the influence of joint geometric parameters on stress concentration factors （SCF） at the weld bottom center and the weld toe of uudermatched butt joint with single V-groove are studied respectively based on the finite element method in this paper. Results show that the reinforcement height and the cover pass width play decisive role in the BLCC for undermatched butt joint. BLCC of undermatched butt joint can be improved by choosing the appropriate joint geometric parameters.
文摘In order to make the fracture cross-section of rock smooth in controlled cutting-blast, generally, two V-shape-notches on the inner wall of a shot hole are notched in symmetry along the design direction. A V-shape notch approximately be considered as V-shape-fracture under certain condition. This paper gave the complex stress function of preformed V-shape-fracture under a blasting load. The stress field and displacement field at the tip of a preformed V-shape-fracture were derived with Westergaard's method, hence its stressintensity factor was obtained. To verify the derived results, blasting tests were made with concrete samples of 400mm×400mm×300mm, and all having, in the center, a drilled hole of 25mm in diameter and 200mm in height. The test result showed that the formulas derived are correct and effective.
