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Background: More research is needed to solidify the basis for reasonable metronomic chemotherapy regimens due to the inconsistent clinical outcomes from studies on metronomic chemotherapy with antineoplastic agents, along with signs of a nonlinear dose-response relationship at low doses. The present study therefore explored the dose-response relationships of representative antineoplastic agents in low dose ranges and their underlying mechanisms. Methods: Cyclophosphamide (CPA) and 5-fluorouracil (5-Fu) were employed to observe the effects of the frequent administration of low-dose antineoplastic agents on tumor growth, tumor angiogenesis, and bone-marrow-derived cell (BMDC) mobilization in mouse models. The effects of antineoplastic agents on tumor and endothelial cell functions with or without BMDCs were analyzed in vitro. Results: Tumor growth and metastasis were significantly promoted after the administration of CPA or 5-Fu at certain low dose ranges, and were accompanied by enhanced tumor angiogenesis and proangiogenic factor expression in tumor tissues, increased proangiogenic BMDC release in the circulating blood, and augmented proangiogenic BMDC retention in tumor tissues. Low concentrations of CPA or 5-Fu were found to significantly promote tumor cell migration and invasion, and enhance BMDC adhesion to endothelial cells in vitro. Conclusion: These results suggest that there are risks in empirical metronomic chemotherapy using low-dose antineoplastic agents and the optimal dosage and administration schedule of antineoplastic agents need to be determined through further research.
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BACKGROUND: The efficacy and safety of direct oral anticoagulants (DOACs) in atrial fibrillation (AF) patients with impaired liver function (ILF) have not been sufficiently studied. The aim of this study was to evaluate the efficacy and safety of DOACs for stroke prevention in patients with AF and ILF. METHOD: This study was based on data from 15 centers in China, including 4,982 AF patients. The patients were divided into 2 subgroups based on their liver function status: patients with normal liver function (NLF)(n = 4213) and patients with ILF (n = 769). Logistic regression analysis was used to investigate the risk of total bleeding, major bleeding, thromboembolism, and all-cause deaths in AF patients with NLF and ILF after taking dabigatran or rivaroxaban, respectively. RESULTS: Among AF patients treated with dabigatran or rivaroxaban, patients with ILF were associated with significantly higher major bleeding, compared with NLF patients (aOR: 4.797; 95% CI: 2.224-10.256; P < 0.001). In patients with NLF, dabigatran (n = 2011) had considerably lower risk of total bleeding than rivaroxaban (n = 2202) (aOR: 1.23; 95% CI: 1.002-1.513; P = 0.049). In patients with ILF, dabigatran (n = 321) significantly favored lower risks of major bleeding compared with rivaroxaban(n = 448) (aOR: 5.484; 95% CI: 1.508-35.269; P = 0.026). CONCLUSION: After using dabigatran or rivaroxaban, patients with ILF had remarkably increased risk of major bleeding compared with patients with NLF. In AF patients with NLF, dabigatran had the distinct strength of significantly reduced risk of total bleeding compared with rivaroxaban. In patients with AF and ILF, dabigatran use was associated with lower risk for major bleeding compared with rivaroxaban.
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Fibrilação Atrial , Dabigatrana , Hemorragia , Rivaroxabana , Humanos , Dabigatrana/efeitos adversos , Dabigatrana/uso terapêutico , Dabigatrana/administração & dosagem , Rivaroxabana/efeitos adversos , Rivaroxabana/uso terapêutico , Rivaroxabana/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/complicações , Masculino , Feminino , Idoso , Hemorragia/induzido quimicamente , Estudos Retrospectivos , Pessoa de Meia-Idade , Antitrombinas/efeitos adversos , Antitrombinas/uso terapêutico , Antitrombinas/administração & dosagem , Acidente Vascular Cerebral/prevenção & controle , Inibidores do Fator Xa/uso terapêutico , Inibidores do Fator Xa/efeitos adversos , Idoso de 80 Anos ou mais , Tromboembolia/prevenção & controleRESUMO
BACKGROUND: There is evidence that the empirical setting of doses and schedules of antineoplastic agents in metronomic chemotherapy (MC) might lead to undesirable outcomes, such as promoting tumor growth or metastasis at certain low doses. However, details about the dose effect of antineoplastic agents in MC have not been fully known yet. OBJECTIVES: Vinorelbine combined with cisplatin or fluorouracil (VNR/CDDP or VNR/FU) was selected to investigate its effects on tumor growth or metastasis as well as mechanisms. METHODS: Experimental techniques, including immunohistochemistry, western blot, immunofluorescence, and flow cytometry, were used to explore the mechanisms, along with cell proliferation, apoptosis, migration, and invasion. RESULTS: The results showed that VNR/CDDP or VNR/FU promoted tumor growth and metastasis at low doses and inhibited them at high ones. Except that expressions of apoptotic proteins were elevated at both low and high doses, low-dose treatments enhanced angiogenesis and promoted the mobilization and recruitment of myeloid-derived suppressor cells (MDSCs), while high-dose treatments reversed these effects. Additionally, low concentrations of VNR/CDDP or VNR/FU stimulated tumor cell functions such as anti-apoptosis, migration, and invasion, but high concentrations only suppressed cell proliferation and increased apoptosis. CONCLUSION: This study elucidated a bidirectional action mode regulated by multiple mechanisms at different doses in MC and also highlighted the risks of low-dose metronomic administration of antineoplastic agents in the clinic. More preclinical and clinical studies focusing on the dose-effect of metronomic regimens are urgently needed because an effective therapeutic regimen should be an optimal setting of drugs, doses, schedules, or combinations.
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Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Melanoma , Animais , Camundongos , Vinorelbina/efeitos adversos , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Vimblastina/farmacologia , Melanoma/tratamento farmacológico , Cisplatino/farmacologia , Antineoplásicos/uso terapêutico , Quimioterapia Combinada , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologiaRESUMO
BACKGROUND: There are limited data about the clinical benefits and harm of direct oral anticoagulants (DOACs) in stroke prevention in patients with atrial fibrillation (AF) complicated with anemia or thrombocytopenia. METHODS: This is a multi-center retrospective cohort study involving 5469 AF patients from 15 hospitals in China. Patients were divided into three groups according to hemoglobin and platelet levels: Group 1 (hemoglobin male ≥ 130 g/L; female ≥ 120 g/L and platelet ≥ 100 × 109/L), Group 2 (hemoglobin male < 130 g/L; female < 120 g/L or platelet < 100 × 109/L), and Group 3 (hemoglobin male < 130 g/L; female < 120 g/L and platelet < 100 × 109/L). Patients in each category are further divided into two groups according to their stroke prevention strategies: rivaroxaban or dabigatran. Clinical results include major, minor, total bleeding, thrombosis, and the composite outcome of major bleeding and thrombosis. RESULTS: Higher hemoglobin levels were associated with a reduced risk of total bleeding and major bleeding, while platelet counts were not associated with any event. Compared with Group 1, Group 2 had a higher risk of major bleeding (aOR 1.70, 95%CI 1.12-2.57, P = 0.012), and the composite endpoint of major bleeding and thrombosis (aOR 1.70, 95%CI 1.19-2.44, P = 0.004). Compared with Group 1, Group 3 had a higher total bleeding risk (aOR 2.15, 95%CI 1.14-4.05, P = 0.018). Compared with dabigatran, rivaroxaban was associated with higher composite risk in Group 1 (aOR 2.91, 95% CI 1.66-5.16, P < 0.001) and Group 2 (aOR 3.05, 95%CI 1.46-6.39, P = 0.003), but there was no significant difference in Group 3 (aOR 1.78, 95%CI 0.23-13.54, P = 0.577). CONCLUSIONS: Higher hemoglobin levels are associated with a reduced risk of total bleeding and major bleeding in patients with AF. Dabigatran was associated with better clinical outcomes than rivaroxaban in patients with anemia or thrombocytopenia but not in those with anemia and thrombocytopenia.
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Determinants of thrombotic events remain uncertain in patients with atrial fibrillation treated with direct oral anticoagulants (DOACs). Our aim was to identify risk factors associated with thromboembolism in patients with at atrial fibrillation on DOACs and to construct and externally validate a predictive model that would provide a validated tool for clinical assessment of thromboembolism. In the development cohort, prediction model was built by logistic regression, the area under the curve (AUC), and Nomogram. External validation and calibration of the model using AUC and Hosmer-Lemeshow test. This national multicenter retrospective study included 3263 patients with atrial fibrillation treated with DOACs. The development cohort consisted of 2390 patients from three centers and the external validation cohort consisted of 873 patients from 13 centers. Multifactorial analysis showed that heavy drinking, hypertension, prior stroke/transient ischemic attack (TIA), cerebral infarction during hospitalization were independent risk factors for thromboembolism. The Alfalfa-TE risk score was constructed using these four factors (AUCâ=â0.84), and in the external validation cohort, the model showed good discriminatory power (AUCâ=â0.74) and good calibration (Hosmer-Lemeshow test P value of 0.649). Based on four factors, we derived and externally validated a predictive model for thromboembolism with DOACs in patients with atrial fibrillation (Alfalfa-TE risk score). The model has good predictive value and may be an effective tool to help reduce the occurrence of thromboembolism in patients with DOACs.
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Fibrilação Atrial , Acidente Vascular Cerebral , Tromboembolia , Humanos , Fibrilação Atrial/complicações , Fibrilação Atrial/tratamento farmacológico , Anticoagulantes/efeitos adversos , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Acidente Vascular Cerebral/tratamento farmacológico , Tromboembolia/etiologia , Tromboembolia/prevenção & controle , Fatores de Risco , Administração OralRESUMO
Background: Prothrombin complex concentrate (PCC) enhances coagulation and controls bleeding. We aimed to assess whether perioperative infusion of PCC is associated with venous thrombosis after cardiac surgery. Methods: We conducted a case-control study of patients undergoing cardiac surgery at our hospital in 2021. Multivariate logistic regression was used to assess the correlation between perioperative PCC infusion and postoperative venous thrombosis in cardiac surgery. Stratified analysis was also performed by age, hospitalization days, and whether warfarin, warfarin combined with heparin, warfarin combined with antiplatelet drugs were used postoperatively. Results: Data from 161 patients undergoing cardiac surgery were included in the analysis. Of these, 37 (23.0%) patients in the case group developed venous thrombosis, and 124 (77.0%) patients in the control group did not develop venous thrombosis. In the analysis without adjustment for confounders (model 1), perioperative PCC infusion significantly increased the risk of postoperative venous thrombosis (OR: 3.10, 95% CI: 1.26-7.59, P = 0.0135). In the model analysis adjusted for sex, age, and hospitalization days (model 2), perioperative PCC infusion was no longer significantly associated with the risk of postoperative venous thrombosis (OR: 1.76, 95% CI: 0.56-7.59, P = 0.3317). In the fully adjusted model (model 3), there was a marginally significant association between perioperative infusion of PCC and the risk of postoperative venous thrombosis (OR: 0.03, 95% CI: 0.00-1.23, P = 0.0637). Conclusions: Our findings show no significant association between perioperative PCC infusion in cardiac surgery and the development of postoperative venous thrombosis. Randomized controlled trials are needed to determine the causal relationship between perioperative PCC infusion and venous thrombosis in cardiac surgery.
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BACKGROUND: Based on the few available studies on the prognostic benefit of using direct oral anticoagulants (DOACs) after atrial fibrillation (AF) ablation. Therefore, this study aimed to evaluate the prognostic differences between patients who underwent radiofrequency ablation (RFA) and those without RFA taking DOACs. METHODS: This is a multicenter retrospective cohort study enrolling 6137 patients with non-valvular AF (NVAF) at 15 hospitals in China. Patient information was collected through a mean follow-up of 10 months and medical record queries. Clinical outcomes included major bleeding, total bleeding, thrombosis, all-cause death, and a composite endpoint of bleeding, thrombosis, and all-cause death. RESULTS: After adjusting for confounders and propensity score matching (PSM), patients with RFA of NVAF had a significantly lower risk of major bleeding [OR 0.278 (95% CI, 0.150-0.515), P<0.001], thrombosis [OR 0.535 (95% CI, 0.316-0.908), P=0.020] and the composite endpoint [ OR 0.835 (95% CI, 0.710-0.982), P=0.029]. In the RFA PSM cohort, dabigatran was associated with reduced all-cause death in patients with RFA of NVAF [OR 0.420 (95% CI, 0.212-0.831), P=0.010]. In the no RFA PSM cohort, rivaroxaban was associated with a reduction in major bleeding [OR 0.521 (95% CI, 0.403-0.673), P<0.001], total bleeding [OR 0.114 (95% CI, 0.049-0.266), P<0.001], and the composite endpoint [OR 0.659 ( 95% CI, 0.535-0.811), P<0.001]. CONCLUSION: Among patients with NVAF treated with DOACs, RFA was a negative correlate of major bleeding, thrombosis, and composite endpoints but was not associated with total bleeding or all-cause mortality.
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Whether there are differences in direct oral anticoagulants efficacy and safety in patients with atrial fibrillation (AF) combined with hypertension is unclear. We therefore conducted a multicenter retrospective cohort study to assess the differences in the efficacy and safety of direct oral anticoagulants in patients with AF combined with hypertension. This multicenter retrospective cohort study was based on data from 15 centers in China and included 2086 patients with AF. We divided the patients into dabigatran and rivaroxaban groups according to their direct oral anticoagulants. Propensity score matching was used to balance the covariates between the groups. Due to our limited sample size, the number of cases of some clinical events with low incidence was small. During a mean follow-up period of 10 months, a total of 268 (12.9%) bleeding events occurred, including 27 (1.3%) major bleeding events and 241 (11.6%) minor bleeding events, and 45 (2.2%) thromboembolic events. In patients with AF combined with hypertension, rivaroxaban was associated with a higher major bleeding incidence than dabigatran (odds ratio [OR], 2.89 [95% confidence interval [CI, 1.22-6.87]; P = .012). In contrast, the risk of thromboembolism and minor bleeding was similar for rivaroxaban (OR, 0.55 [95%CI, 0.29-1.01]; P = .069) and dabigatran (OR, 0.82 [95%CI, 0.63-1.08]; P = .150). Based on the results of this study, in patients with AF and hypertension treated with direct oral anticoagulants, the incidence of thromboembolism and minor bleeding was not statistically different between dabigatran and rivaroxaban, but compared with rivaroxaban, dabigatran was associated with a lower risk of major bleeding.
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Fibrilação Atrial , Hipertensão , Acidente Vascular Cerebral , Tromboembolia , Humanos , Fibrilação Atrial/complicações , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/epidemiologia , Rivaroxabana/efeitos adversos , Dabigatrana/efeitos adversos , Anticoagulantes/efeitos adversos , Varfarina , Estudos Retrospectivos , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Tromboembolia/epidemiologia , Tromboembolia/prevenção & controle , Tromboembolia/complicações , Administração Oral , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológicoRESUMO
PURPOSE: Our aim was to identify factors associated with major bleeding in patients with atrial fibrillation (AF) on direct oral anticoagulants (DOACs) and to construct and externally validate a predictive model that would provide a validated tool for clinical assessment of major bleeding. METHODS: In the development cohort, prediction model was built by logistic regression, the area under the curve (AUC), and Nomogram. External validation, analytical identification and calibration of the model using AUC, calibration curves and Hosmer-Lemeshow test. RESULTS: The development cohort consisted of 4209 patients from 7 centers and the external validation cohort consisted of 1800 patients from 12 centers. Multifactorial analysis showed that age > 65 years, history of bleeding, anemia, vascular disease, antiplatelet therapy/non-steroidal anti-inflammatory drugs and rivaroxaban were independent risk factors for major bleeding, and gastrointestinal protective agents was a protective factor. The Alfalfa-MB model was constructed using these seven factors (AUC = 0.807), and in the external validation cohort, the model showed good discriminatory power (AUC = 0.743) and good calibration (Hosmer-Lemeshow test P value of 0.205). The predictive power of the six bleeding scores was ORBIT (AUC = 0.706), HAS-BLED (AUC = 0.648), ATRIA (AUC = 0.645), HEMORR2 HAGES (AUC = 0.632), ABC (AUC = 0.619) and Shireman (AUC = 0.599) in descending order. CONCLUSION: Based on 7 factors, we derived and externally validated a predictive model for major bleeding with DOACs in patients with AF (Alfalfa-MB). The model has good predictive value and may be an effective tool to help reduce the occurrence of major bleeding in patients with DOACs.
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Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Idoso , Fibrilação Atrial/epidemiologia , Anticoagulantes/efeitos adversos , Medição de Risco , Hemorragia/induzido quimicamente , Acidente Vascular Cerebral/epidemiologia , Fatores de RiscoRESUMO
PURPOSE: We conducted a multicenter real-world study in China to assess the association between body mass index (BMI) and clinical outcomes in patients with atrial fibrillation (AF) taking direct oral anticoagulants (DOACs). METHOD: This is a retrospective multicenter cohort study conducted in 15 centers in China. We collected demographic information through the hospital information system and obtained clinical events through follow-up visits to patients or relatives. Clinical outcomes include major, minor, total bleeding, thromboembolism, and all-cause death. RESULT: A total of 6164 patients with non-valvular AF (NVAF) were included in this study. The incidence of major bleeding in patients with NVAF differed significantly by BMI category (P < 0.001), with 5.2% in the underweight group, 2.6% in the normal group, 1.4% in the overweight group, 1.1% in the obese I group, and 1.3% in the obese II group. There was no significant difference in minor, total bleeding, and thrombosis in the five groups (P = 0.493; P = 0.172; P = 0.663). All-cause death was significantly different among the five groups (P < 0.001), with 8.9% in the underweight group, 6.3% in the normal group, 4.8% in the overweight group, 2.2% in the obese I group, and 0.4% in the obese II group. High BMI was negatively associated with major bleeding (OR = 0.353, 95% CI 0.205-0.608), total bleeding (OR = 0.664, 95% CI 0.445-0.991), and all-cause death (OR = 0.370, 95% CI 0.260-0.527). CONCLUSION: In patients with NVAF treated with DOACs, higher BMI was associated with lower major bleeding and better survival. BMI was a negative correlate of total bleeding, but not minor bleeding and thrombosis.
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Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/epidemiologia , Índice de Massa Corporal , Anticoagulantes/efeitos adversos , Sobrepeso/complicações , Sobrepeso/tratamento farmacológico , Sobrepeso/epidemiologia , Paradoxo da Obesidade , Magreza/diagnóstico , Magreza/epidemiologia , Magreza/complicações , Estudos de Coortes , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Obesidade/diagnóstico , Obesidade/epidemiologia , Administração OralRESUMO
AIM: This study aimed to evaluate the label compliance of DOACs in the Chinese AF population and explore the relationship between inappropriate DOACs dosage and clinical results. METHODS AND RESULTS: This is a retrospective multicenter cohort study conducted in 14 centers in China. According to the China Food and Drug Administration(CFDA) label and the recommendations of international guidelines, we divided patients into on-label dosage and off-label dosage. We then compared the clinical results after propensity score matching. We collect demographic information through the hospital information system and obtain clinical events through follow-up of patients or their families. Clinical results include major, minor, total bleeding, thrombosis, and all-cause death. 4191 patients with non-valvular AF (NVAF) were included, and approximately 55.6% and 1.7% of AF patients received off-label underdose and off-label overdose of DOACs, respectively. Compared with the on-label dose, DOACs with off-label underdose were associated with a significantly reduced risk of major bleeding (P = 0.004, OR = 0.23,95% CI: 0.08-0.69) and all-cause death (P<0.001, OR = 0.49,95% CI: 0.33-0.73). However, there was no significant difference in thrombotic events (P = 0.865 OR = 1.06,95% CI: 0.54-2.07) and minor bleeding (P = 0.465, OR = 1.10,95% CI: 0.85-1.43) risk. CONCLUSIONS: About 57.3% of Asian AF patients received an off-label dose of DOACs in daily practice. Off-label underdose DOACs were associated with significantly lower risks of major bleeding, all-cause death, and similar risks of minor bleeding, thrombotic events compared with on-label dose DOACs. Further prospective randomized trials are needed to determine the optimal dose of DOACs in Asian patients with AF at high bleeding risk.
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Fibrilação Atrial , Acidente Vascular Cerebral , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/complicações , Estudos de Coortes , Administração Oral , Resultado do Tratamento , Anticoagulantes , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controleRESUMO
AIMS: There is emerging evidence that antineoplastic agents and the cytotoxic effects on tumor tissues attenuate the benefits of chemotherapy due to tumor microenvironment changes. Nevertheless, the actual relationship between chemotherapy and recurrent tumors in which the genotypes differ from the original tumor after chemotherapy is unclear. MATERIALS AND METHODS: Bone marrow transplantation, flow cytometer, immune inhibition and immunofluorescence will be utilized to investigate the effect of antineoplastic agents on bone-marrow-derived cells (BMDCs) release and recruitment, and to explore the pathways and mechanisms of antineoplastic agents in promoting tumor growth. KEY FINDINGS: Tumor growth and angiogenesis were significantly enhanced in the mouse model after treatment with antineoplastic agents such as cyclophosphamide, 5-fluorouracil, or cisplatin, along with large increases in proangiogenic vascular endothelial growth factor receptor-2 (VEGFR2+), ß3+, CD11b+Gr-1+, and VEGFR2+ß3+ BMDCs in circulating blood. BMDC recruitment and VEGFR2 and ß3 mRNA transcription in tumor tissues were also enhanced by antineoplastic agents. Antineoplastic-agent-treated BMDCs markedly augmented tumor and endothelial cell proliferation, and ß3 mRNA transcription in endothelial cells (ECs). SIGNIFICANCE: The results suggested that antineoplastic-agent treatment augmented the tumor microenvironment by mobilizing proangiogenic BMDCs, enhancing BMDC recruitment and angiogenesis, and increasing BMDC-mediated tumor and EC functions. These results led to tumor growth and angiogenesis aggravation. It is paramount to elucidate the potential mechanism by which the cellular and molecular effects triggered by the antineoplastic agents attenuate the effects of cancer therapy, and thereafter to explore possible methods for improving tumor treatment efficacy.
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Antineoplásicos , Neoplasias , Animais , Camundongos , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo , Células da Medula Óssea/metabolismo , Células Endoteliais/metabolismo , Neoplasias/metabolismo , Neovascularização Patológica/metabolismo , RNA Mensageiro/metabolismo , Microambiente Tumoral , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
MAJOR FINDING: This study observes a previously neglected pharmacological phenomenon and investigates its mechanism of that the continuous low-dose administration of some antineoplastic agents in certain dose ranges can promote tumorigenesis and tumor progression in vitro and in vivo, through stimulation of tumor cell functions directly as well as enhancement of tumor angiogenesis by BMDCs recruitment indirectly. The results alert to a potential risk in current empirically based continuous low-dose chemotherapy regimens such as metronomic chemotherapy. BACKGROUND AND OBJECTIVES: There are indications that certain antineoplastic agents at low dosages may exhibit abnormal pharmacological actions, such as promoting tumor growth. However, the phenomenon still needs to be further confirmed, and its underlying mechanisms have not yet been fully elucidated. METHODS: Gemcitabine (GEM) and cisplatin (CDDP) were employed as representative antineoplastic agents to observe effects of continuous low-dose chemotherapy with GEM or GEM combined with CDDP (GEM+CDDP) on tumor formation and growthin xenograft tumor models in vivo. Tumor and endothelial cell functions, apoptosis, cell cycle analysis, as well as bone marrow derived cells (BMDCs) mobilization, were evaluated with transwell, MTT or flow cytometry analysis in vitro, respectively. Histological methods were employed to assess angiogenesis in tumor tissues. RESULTS: The results showed that tumor formation and growth were both significantly promoted by GEM or GEM+CDDP at as low as half of the metronomic dosages, which were accompanied by enhancements of angiogenesis in tumor tissues and the release of proangiogenic BMDCs in the circulating blood. Additionally, GEM or GEM+CDDP at low concentrations dramatically facilitated the proliferation, migration, and invasion of tumor cells in vitro. Cell-cycle arrest, activation of associated apoptotic proteins, and inhibition of apoptosis were also observed in tumor cells. CONCLUSIONS: These findings indicate that, the continuous low-dose administration of GEM and GEM+CDDP can promote tumorigenesis and tumor progression in vivo by inhibiting apoptosis, mobilizing BMDCs, and promoting angiogenesis in certain dose ranges. These findings urge further investigations to avoid the potential risks in current empiric continuous low-dose chemotherapy regimens with antineoplastic agents.
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Antineoplásicos , Neoplasias , Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinogênese , Linhagem Celular Tumoral , Cisplatino/farmacologia , Desoxicitidina/análogos & derivados , Humanos , Neoplasias/tratamento farmacológico , GencitabinaRESUMO
OBJECTIVE: To observe the differences in curative effects between prophylactic and therapeutic administrations of Gliclazide (GLZ) or Methylcobalamin (MCA) on diabetic peripheral neuropathy in rats. METHODS: GLZ (25 mg/kg/day) or MCA (175 µg/kg/day) was orally administrated prophylactically to streptozotocin-induced diabetic rats for 8 weeks before diabetic peripheral neuropathy developed or administrated therapeutically after diabetic peripheral neuropathy developed, respectively. The motor nerve conduction velocities (MNCV), aldose reductase (AR) activities, the polyol contents and antioxidative enzyme activities in the sciatic never tissues were determined. The morphology of sciatic never tissues was observed. RESULTS: In comparison to vehicle, most of the changes in the sciatic nerves of the diabetic rats (e. g., delayed MNCV, altered/damaged nerve structure, enhanced AR activity, increased polyol contents, altered Cu, Zn-superoxide dismutase, glutathione-peroxidase activities, and elevated malondialdehyde level) were significantly ameliorated by prophylactic administration with either GLZ or MCA. In contrast, only few of above-mentioned parameters were alleviated in DPN rats by therapeutic administration with GLZ or MCA as compared to vehicle. The curative effects of GLZ or MCA prophylactic administration on MNCV, AR activity, polyol contents and antioxidative enzyme activities were markedly stronger than therapeutic administration. CONCLUSION: Prophylactic administration of GLZ or MCA was superior to the therapeutic administration in alleviation of diabetic neuropathy in STZ-rats, suggesting that pharmacotherapy should be initiated at a much earlier stage before diabetic neuropathy developed, but not at a later stage after never damage reached.
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Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/prevenção & controle , Neuropatias Diabéticas/tratamento farmacológico , Neuropatias Diabéticas/prevenção & controle , Gliclazida/administração & dosagem , Hipoglicemiantes/administração & dosagem , Vitamina B 12/análogos & derivados , Complexo Vitamínico B/administração & dosagem , Animais , Diabetes Mellitus Experimental/complicações , Neuropatias Diabéticas/etiologia , Ratos , Fatores de Tempo , Vitamina B 12/administração & dosagemRESUMO
Brain ischemia, including cerebral ischemia and cerebrovascular ischemia, leads to poor oxygen supply or cerebral hypoxia, and causes brain tissue death or cerebral infarction/ischemic stroke. The troxerutin and cerebroprotein hydrolysate injection (TCHI), is widely applied in China to improve blood supply in ischemic brain tissues and to enhance neuroprotective effects in clinical practice. However, the benefits and detailed underlying mechanism elaborating the effectiveness of TCHI in cerebrovascular diseases require further investigation. Therefore, in the present study, experimental in vivo and in vitro models were employed to investigate the potential mechanisms of TCHI on cerebral ischemic injury. The results demonstrated that TCHI increased the lactate dehydrogenase levels in the brain homogenate and conversely decreased lactic acid levels. TCHI was further observed to significantly increase superoxide dismutase activity and decrease malondialdehyde levels in ischemic brain tissues. In addition, TCHI significantly induced vascular maturation processes, including proliferation, adhesion, migration and tube formation in cultured human umbilical vein endothelial cells. Additionally, TCHI significantly stimulated microvessel formation in the rat aortic ring and chick chorioallantoic membrane assays. Taken together, these results provided strong evidence that TCHI stimulated angiogenesis at multiple steps, and indicated that TCHI attenuated cerebral ischemic damage through the amelioration of oxidative stress and promotion of angiogenesis.
Assuntos
Anticoagulantes/farmacologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Hidroxietilrutosídeo/análogos & derivados , Neovascularização Patológica/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Biomarcadores , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/etiologia , Adesão Celular , Movimento Celular , Modelos Animais de Doenças , Células Endoteliais da Veia Umbilical Humana , Humanos , Hidroxietilrutosídeo/farmacologia , Masculino , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Estradiol (E2) is a prime culprit for enhancing the progression of female hormonerelated cancers. Bone marrowderived cells (BMDCs) have been found to play a pivotal role in tumor growth. Estrogen receptors (ERs) are also found on certain subtypes of BMDCs, in addition to endothelial cells (ECs) and certain tumor cells. However, the role of BMDCs in E2induced tumor biology is still unclear. Thus, the effects of E2 on ERnegative 4T1 breast cancer growth, the mobilization and recruitment of BMDCs, and interactions among BMDCs, ECs, and 4T1 cells were investigated. The results showed that E2 potentiated 4T1 tumor growth and angiogenesis in mice subjected to sham operation, ovariectomy (OVX), or OVX and E2 replacement treatment. E2 supplementation in mice with OVX upregulated the transcription of stromal cellderived factor1 (SDF1) mRNA in tumor tissues and enhanced the recruitment of BMDCs into tumor tissues in vivo. E2 deficiency significantly decreased proangiogenic CXCR4+, ß3+, Sca1+ and CXCR4+ß3+ BMDCs circulating in the peripheral blood. Cellbased system analyses showed that E2 augmented the transcription of ß3 mRNA in ECs, increased the adhesion of BMDCs to ECs. In addition, E2 enhanced the BMDCinduced EC proliferation and migration, the BMDCinduced 4T1 proliferation and the 4T1stimulated EC proliferation in addition to enhancing the proliferation of tumor cells and the migration of ECs in vitro. Therefore, E2 enhanced the growth of breast tumors by stimulating tumor cells and ECs directly, as well as by increasing proangiogenic BMDC mobilization and recruitment leading to augmentation of the tumor and EC functions indirectly by cell proliferation assay. These findings reveal a separate mechanism via which E2 promotes the growth of female hormonedependent tumors, which may be useful in explorations of new therapies for related cancers.
Assuntos
Medula Óssea/patologia , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/patologia , Proliferação de Células , Endotélio Vascular/patologia , Estrogênios/toxicidade , Neovascularização Patológica/patologia , Animais , Apoptose , Biomarcadores Tumorais/metabolismo , Medula Óssea/efeitos dos fármacos , Neoplasias da Mama/induzido quimicamente , Adesão Celular , Movimento Celular , Meios de Cultivo Condicionados/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neovascularização Patológica/induzido quimicamente , Transdução de Sinais , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Granulocyte-macrophage colony-stimulating factor has been widely used as an adjuvant therapy for cancer patients exhibiting myelosuppression induced by chemotherapy or radiotherapy. However, the effects of granulocyte-macrophage colony-stimulating factor on tumor growth, as well as its precise mechanism, are still controversial due to inconsistent evidence. This study investigated the effect of exogenous granulocyte-macrophage colony-stimulating factor on the growth of B16 melanoma, S180 sarcoma, and U14 cervical carcinoma in mice. The angiogenesis and recruitment of bone-marrow-derived cells were analyzed in tumor tissues. Interactions among granulocyte-macrophage colony-stimulating factor, bone-marrow-derived cells, and B16 tumor cells were investigated in vitro. Proangiogenic types of bone-marrow-derived cells in blood were assessed both in vivo and in vitro. The results showed that granulocyte-macrophage colony-stimulating factor markedly facilitated the growth of B16 and S180 tumors, but not U14 tumors. Granulocyte-macrophage colony-stimulating factor increased the densities of blood vessels and the number of bone-marrow-derived cells in B16 tumor tissues. The granulocyte-macrophage colony-stimulating factor-induced enhancement of tumor cell proliferation was mediated by bone-marrow-derived cells in vitro. Meanwhile, a distinct synergistic effect on endothelial cell function between granulocyte-macrophage colony-stimulating factor and bone-marrow-derived cells was observed. After separating two types of bone-marrow-derived cells, granulocyte-macrophage colony-stimulating factor-induced enhancement of tumor growth and angiogenesis in vivo was mediated by proangiogenic cells in granulocytes, but not monocytes, with CD11b+, vascular endothelial growth factor receptor 2, and C-X-C chemokine receptor 4 granulocytes possibly involved. These data suggest that granulocyte-macrophage colony-stimulating factor contributes to the growth and angiogenesis of certain types of tumor, and these mechanisms are probably mediated by proangiogenic cells in granulocytes. Applying granulocyte-macrophage colony-stimulating factor may attenuate the antitumor effects of chemotherapy and radiotherapy in certain types of tumor.
Assuntos
Células Endoteliais/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Granulócitos/efeitos dos fármacos , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/patologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Processos de Crescimento Celular/efeitos dos fármacos , Embrião de Galinha , Feminino , Granulócitos/patologia , Células Endoteliais da Veia Umbilical Humana , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Patológica/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Distribuição AleatóriaRESUMO
AIMS: This study investigated the efficacies of gliclazide (GLZ), methylcobalamin (MCA), and GLZ+MCA combination therapy on DPN by evaluating the treatment-related changes in peripheral nerve function, the polyol pathway, and oxidative stress in the sciatic nerve of streptozotocin-induced diabetic rats. MATERIALS AND METHODS: The rat model of streptozotocin-induced diabetes was orally given GLZ (25mg/kg/day), MCA (175µg/kg/day), and GLZ+MCA (25mg/kg/day+175µg/kg/day) combination therapy for 8weeks, in order to observe its effects on the motor nerve conduction velocity (MNCV), on the activities of Na(+), K(+)-ATPase, aldose reductase(AR), AR mRNA expression, on the polyol contents, antioxidative enzyme activities and peroxidation products in the sciatic never tissue. KEY FINDINGS: Most of the indicators of DPN, such as delayed MNCV, altered/damaged nerve structure, inhibited Na(+),K(+)-ATPase activity, enhanced AR activity and AR mRNA expression, increased polyol contents, altered Cu,Zn-superoxide dismutase, catalase, and glutathione-peroxidase activities, and elevated malondialdehyde level in the sciatic nerves of the diabetic rats, were significantly ameliorated by treatment with either GLZ or MCA. Moreover, the combination of GLZ and MCA was found to enhance the curative effect on DPN in parts of above-mentioned parameters as compared to monotherapy. SIGNIFICANCE: Monotherapy with GLZ or MCA, and especially the combined application of GLZ and MCA, could be efficient therapeutic strategies for combating experimental DPN in diabetic rats.
Assuntos
Neuropatias Diabéticas/tratamento farmacológico , Gliclazida/administração & dosagem , Vitamina B 12/análogos & derivados , Animais , Glicemia/metabolismo , Neuropatias Diabéticas/metabolismo , Quimioterapia Combinada , Masculino , Estresse Oxidativo , Ratos , Ratos Wistar , Nervo Isquiático/patologia , Estreptozocina , Vitamina B 12/administração & dosagemRESUMO
OBJECTIVE: To determine the health risks of antineoplastic drugs (ADs) occupational exposure in nurses and to evaluate the effects of implementing a pharmacy intravenous admixture service (PIVAS) in two Chinese hospitals. METHODS: The laboratory findings were collected from annual staff physical examination data. Reproductive toxicity and clinical manifestations were self-reported via a questionnaire. RESULTS: Hematotoxicity, organ damage, reproductive toxicity, and clinical manifestations associated with AD exposure were markedly higher in oncology nurses than unexposed nurses. Application of PIVAS led to a significant restoration of the blood cell counts and kidney function, and a reduction in adverse reproductive outcomes among oncology nurses. Pronounced symptoms related to AD exposure were alleviated as well. CONCLUSION: Oncology nurses who work with AD's experienced more adverse health outcomes than unexposed nurses. The health risks to AD were significantly alleviated by implementing a pharmacy intravenous admixture service.
Assuntos
Antineoplásicos/efeitos adversos , Recursos Humanos de Enfermagem Hospitalar/estatística & dados numéricos , Doenças Profissionais/induzido quimicamente , Exposição Ocupacional/efeitos adversos , Serviço de Farmácia Hospitalar/métodos , Administração Intravenosa , Adulto , Antídotos/administração & dosagem , China , Feminino , Humanos , Pessoa de Meia-Idade , Doenças Profissionais/prevenção & controle , Medição de Risco , Adulto JovemRESUMO
Previous studies have found that Danhong injection (DHI), an extensively used herbal extract preparation in China, might be a powerful vasodilator. The aims of this study were to determine the vascular activity of DHI and its effects on arteries of different sizes. The results showed that DHI significantly inhibited rat-hindquarters and rabbit-ear vasoconstriction elicited by norepinephrine (NE) perfusion and markedly relaxed KCl-contracted and NE-contracted rat abdominal aortic and mesenteric artery rings. The endothelium made only a minor contribution to the vasorelaxant effect of DHI on artery segments. The vasorelaxant effect of DHI varied with the artery size, with larger arteries exhibiting a more sensitive and potent vasodilator response. DHI relaxed NE-induced vasoconstriction probably through inhibition of the intracellular Ca2+ release through the inositol triphosphate receptor system in the abdominal aorta and mesenteric artery, along with blockage of extracellular Ca2+ influx through the receptor-linked Ca2+ channels in the mesenteric artery. In addition, DHI completely relaxed KCl-induced contraction in both of the arteries, suggesting that inhibition of Ca2+ influx through voltage-gated Ca2+ channels is involved in the vasorelaxant effect of DHI. This elucidation of the vascular effects of DHI and the underlying mechanisms could lead to improved clinical applications.