Objective:To evaluate the effect of dexmedetomidine on the viability of dopaminergic neurons in the ventral tegmental area (VTA) of morphine-addicted mice.Methods:Experiment Ⅰ Thirty SPF healthy adult male C57BL/6 mice, aged 8 weeks, weighing 20-25 g, were divided into 3 groups ( n=10 each) using the random number table method: normal saline group (NS group), dexmedetomidine 50 μg/kg group (DEX50 group), and dexmedetomidine 100 μg/kg group (DEX100 group). A morphine addiction model was established by intraperitoneal injection of increasing doses of morphine (10, 20, 30, 40, 50 and 50 mg/kg) for 6 consecutive days in mice. After the successful establishment of the model, dexmedetomidine 50 and 100 μg/kg were intraperitoneally injected for 14 consecutive days in group DEX50 and group DEX100 respectively, while normal saline was given instead in group C. The conditioned place preference (CPP) experiment was conducted every other day. Experiment Ⅱ Thirty SPF healthy adult male C57BL/6 mice, aged 8 weeks, weighing 20-25 g, were divided into 3 groups ( n=10 each) by the random number table method: control group (C group), morphine group (Mor group) and dexmedetomidine 50 μg/kg group (DEX50 group). Normal saline was intraperitoneally injected for 10 consecutive days in group C. Morphine with increasing doses was intraperitoneally injected for 6 days, and then normal saline was intraperitoneally injected for 4 consecutive days in group Mor. Morphine with increasing doses was intraperitoneally injected for 6 days, and then dexmedetomidine 50 μg/kg was intraperitoneally injected for 4 consecutive days in group DEX50. The mice were anesthetized at 90 min after the last intraperitoneal injection, brain tissues were harvested, and the corresponding brain slices of the VTA were selected for c-Fos immunofluorescence staining. Experiment Ⅲ Ten dopamine transporter-Cre recombinase mice were divided into 2 groups ( n=5 each) by the random number table method: morphine group (Mor group) and morphine+ dexmedetomidine 50 μg/kg group (Mor+ DEX group). Stereotaxic viral injection was performed in the brain. rAAV-EF1α-DIO-GCaMP6s was injected into the VTA and an optical fiber was implanted. Three weeks later, a morphine addiction model was established based on Experiment Ⅰ for the CPP experiment, morphine was intraperitoneally injected in group Mor, and morphine and dexmedetomidine were intraperitoneally injected in group Mor+ DEX. The viral fluorescence signals were recorded at 5 min before and 20 min after the drug administration in the three groups. Results:Experiment Ⅰ There was no statistically significant difference in the CPP scores after developing the morphine addiction model among the three groups ( P>0.05). Compared with group NS, the CPP scores were significantly decreased at 4-14 days of the continuous administration in group DEX50 and group DEX100 ( P<0.05). Experiment Ⅱ Compared with group C, the number of c-Fos positive cells in the VTA was significantly increased in group Mor ( P<0.05). Compared with group Mor, the number of c-Fos positive cells in the VTA was significantly decreased in group DEX ( P<0.05). Experiment Ⅲ Compared with that before administration, the calcium signals of dopaminergic neurons in the VTA were significantly enhanced in group Mor ( P<0.05), and no statistically significant difference was found in the calcium signals of dopaminergic neurons in the VTA in group Mor+ DEX ( P>0.05). Compared with group Mor, no statistically significant difference was found in the calcium signals of dopaminergic neurons in the VTA before drug administration ( P>0.05), and the calcium signals of dopaminergic neurons in the VTA were significantly weakened after administration in group Mor+ DEX ( P<0.05). Conclusions:The mechanism by which dexmedetomidine promotes the extinction of morphine addiction is related to the inhibition of the viability of dopaminergic neurons in the VTA of mice.

Objective:To report the preclinical trial results of the application of a domestic high-flow percutaneous left ventricular assist device (pLVAD) in patients with low cardiac output syndrome (LCOS) following cardiac surgery.Methods:Six patients who developed LCOS after direct cardiac surgery were implanted with a domestic high-flow pLVAD. Clinical outcomes, including hemodynamic changes, complications, and survival rates were observed post-implantation.Results:Four patients underwent pLVAD implantation under digital subtraction angiography (DSA) guidance, while two patients had the procedure performed under ultrasound guidance. The implantation process was straightforward, rapid, and uneventful, with no instances of bleeding or arrhythmias. The flow rate at the initiation of pLVAD support was 3.8-5.0 (4.22±0.44)L/min, and the flow rate during pump removal was 1.0-1.3(1.18±0.15)L/min. The duration of pLVAD support was 16.5-165.0(101.3±60.65)h. Hemodynamic parameters showed immediate improvement following pLVAD support: mean arterial pressure increased from (62.67±4.46)mmHg to (80.50±18.96)mmHg (1 mmHg=0.133 kPa, P=0.049), cardiac output increased from (2.45±0.66)L/min to (4.35±1.32)L/min( P=0.01), cardiac index improved from (1.95±0.21)L·min -1·m -2 to (2.77±0.33)L·min -1·m -2( P<0.001), pulmonary artery diastolic pressure decreased from (27.50±1.87) mmHg to(18.33±4.18)mmHg( P=0.001), and left ventricular ejection fraction improved from 0.27±0.04 to 0.37±0.06 ( P=0.004). No visible hemoglobinuria was noted during the support period. No malignant arrhythmias or cerebrovascular complications occurred. One patient required transition to surgical LVAD implantation, while the other five patients had the pLVAD successfully removed and were discharged. Three months later, all six patients were alive, with functional status classified as New York Heart Association (NYHA) Class Ⅰ-Ⅱ. Conclusion:The implantation of a domestic high-flow pLVAD provides a safe and effective therapeutic option for patients with LCOS following cardiac surgery.

Objective:To evaluate the effect of dexmedetomidine on the viability of dopaminergic neurons in the ventral tegmental area (VTA) of morphine-addicted mice.Methods:Experiment Ⅰ Thirty SPF healthy adult male C57BL/6 mice, aged 8 weeks, weighing 20-25 g, were divided into 3 groups ( n=10 each) using the random number table method: normal saline group (NS group), dexmedetomidine 50 μg/kg group (DEX50 group), and dexmedetomidine 100 μg/kg group (DEX100 group). A morphine addiction model was established by intraperitoneal injection of increasing doses of morphine (10, 20, 30, 40, 50 and 50 mg/kg) for 6 consecutive days in mice. After the successful establishment of the model, dexmedetomidine 50 and 100 μg/kg were intraperitoneally injected for 14 consecutive days in group DEX50 and group DEX100 respectively, while normal saline was given instead in group C. The conditioned place preference (CPP) experiment was conducted every other day. Experiment Ⅱ Thirty SPF healthy adult male C57BL/6 mice, aged 8 weeks, weighing 20-25 g, were divided into 3 groups ( n=10 each) by the random number table method: control group (C group), morphine group (Mor group) and dexmedetomidine 50 μg/kg group (DEX50 group). Normal saline was intraperitoneally injected for 10 consecutive days in group C. Morphine with increasing doses was intraperitoneally injected for 6 days, and then normal saline was intraperitoneally injected for 4 consecutive days in group Mor. Morphine with increasing doses was intraperitoneally injected for 6 days, and then dexmedetomidine 50 μg/kg was intraperitoneally injected for 4 consecutive days in group DEX50. The mice were anesthetized at 90 min after the last intraperitoneal injection, brain tissues were harvested, and the corresponding brain slices of the VTA were selected for c-Fos immunofluorescence staining. Experiment Ⅲ Ten dopamine transporter-Cre recombinase mice were divided into 2 groups ( n=5 each) by the random number table method: morphine group (Mor group) and morphine+ dexmedetomidine 50 μg/kg group (Mor+ DEX group). Stereotaxic viral injection was performed in the brain. rAAV-EF1α-DIO-GCaMP6s was injected into the VTA and an optical fiber was implanted. Three weeks later, a morphine addiction model was established based on Experiment Ⅰ for the CPP experiment, morphine was intraperitoneally injected in group Mor, and morphine and dexmedetomidine were intraperitoneally injected in group Mor+ DEX. The viral fluorescence signals were recorded at 5 min before and 20 min after the drug administration in the three groups. Results:Experiment Ⅰ There was no statistically significant difference in the CPP scores after developing the morphine addiction model among the three groups ( P>0.05). Compared with group NS, the CPP scores were significantly decreased at 4-14 days of the continuous administration in group DEX50 and group DEX100 ( P<0.05). Experiment Ⅱ Compared with group C, the number of c-Fos positive cells in the VTA was significantly increased in group Mor ( P<0.05). Compared with group Mor, the number of c-Fos positive cells in the VTA was significantly decreased in group DEX ( P<0.05). Experiment Ⅲ Compared with that before administration, the calcium signals of dopaminergic neurons in the VTA were significantly enhanced in group Mor ( P<0.05), and no statistically significant difference was found in the calcium signals of dopaminergic neurons in the VTA in group Mor+ DEX ( P>0.05). Compared with group Mor, no statistically significant difference was found in the calcium signals of dopaminergic neurons in the VTA before drug administration ( P>0.05), and the calcium signals of dopaminergic neurons in the VTA were significantly weakened after administration in group Mor+ DEX ( P<0.05). Conclusions:The mechanism by which dexmedetomidine promotes the extinction of morphine addiction is related to the inhibition of the viability of dopaminergic neurons in the VTA of mice.

Objective:To report the preclinical trial results of the application of a domestic high-flow percutaneous left ventricular assist device (pLVAD) in patients with low cardiac output syndrome (LCOS) following cardiac surgery.Methods:Six patients who developed LCOS after direct cardiac surgery were implanted with a domestic high-flow pLVAD. Clinical outcomes, including hemodynamic changes, complications, and survival rates were observed post-implantation.Results:Four patients underwent pLVAD implantation under digital subtraction angiography (DSA) guidance, while two patients had the procedure performed under ultrasound guidance. The implantation process was straightforward, rapid, and uneventful, with no instances of bleeding or arrhythmias. The flow rate at the initiation of pLVAD support was 3.8-5.0 (4.22±0.44)L/min, and the flow rate during pump removal was 1.0-1.3(1.18±0.15)L/min. The duration of pLVAD support was 16.5-165.0(101.3±60.65)h. Hemodynamic parameters showed immediate improvement following pLVAD support: mean arterial pressure increased from (62.67±4.46)mmHg to (80.50±18.96)mmHg (1 mmHg=0.133 kPa, P=0.049), cardiac output increased from (2.45±0.66)L/min to (4.35±1.32)L/min( P=0.01), cardiac index improved from (1.95±0.21)L·min -1·m -2 to (2.77±0.33)L·min -1·m -2( P<0.001), pulmonary artery diastolic pressure decreased from (27.50±1.87) mmHg to(18.33±4.18)mmHg( P=0.001), and left ventricular ejection fraction improved from 0.27±0.04 to 0.37±0.06 ( P=0.004). No visible hemoglobinuria was noted during the support period. No malignant arrhythmias or cerebrovascular complications occurred. One patient required transition to surgical LVAD implantation, while the other five patients had the pLVAD successfully removed and were discharged. Three months later, all six patients were alive, with functional status classified as New York Heart Association (NYHA) Class Ⅰ-Ⅱ. Conclusion:The implantation of a domestic high-flow pLVAD provides a safe and effective therapeutic option for patients with LCOS following cardiac surgery.

Objective:To evaluate the role of lactate-induced mitochondrial division of spinal cord neurons in diabetic neuropathic pain (DNP) in mice.Methods:Thirty-six SPF-grade healthy adult male C57BL/6 mice, aged 2 months, weighing 20-25 g, were divided into 3 groups ( n=12 each) using a random number table method: control group (CON group), DNP group, and DNP+ sodium oxalate group (OXA group). The diabetic model was established by intraperitoneal injection of streptozotocin 130 mg/kg. After the diabetic model was successfully established, sodium oxalate 750 mg/kg was intraperitoneally injected once a day for 4 consecutive weeks to inhibit lactate production in OXA group, while the equal volume of normal saline was given instead at the same time in C group and DNP group. The mechanical paw withdrawal threshold (MWT) of the left hindpaw was measured before developing the model and at 1, 2, 3 and 4 weeks after developing the model. After completing the last behavioral testing, the spinal cord tissue of the lumbar segment (L 4-6) was taken for determination of the levels of lactate in serum and spinal cord tissues (by the colorimetric method), expression of the mitochondrial membrane potential, reactive oxygen species (ROS) content (using JC-1 or DHE probes), expression of mitochondrial dynamin-related protein 1 (Drp1) and mitochondrial protein mitofusin 2 (Mfn2) (by Western blot), and co-expression of Drp1 and neuronal neuronal marker neuronal nuclear protein (NeuN) (by immunofluorescence double labeling) and for examination of the structure and the number of mitochondria (with a transmission electron microscope). Results:Compared with C group, the MWT was significantly decreased after developing the model, the levels of lactate in serum and spinal cord tissues and ROS content in the spinal cord were increased, the mitochondrial membrane potential was decreased, the Drp1 expression was up-regulated, the Mfn2 expression was down-regulated, the number of mitochondria was increased, the area was reduced ( P<0.05), and the co-expression of Drp 1 and NeuN was increased in DNP group and OXA group. Compared with DNP group, the MWT was significantly increased after developing the model, the levels of lactate in serum and spinal cord tissues and ROS content in the spinal cord were decreased, the mitochondrial membrane potential was increased, the Drp1 expression was down-regulated, the Mfn2 expression was up-regulated, the number of mitochondria was decreased, the area was increased ( P<0.05), and the co-expression of Drp 1 and NeuN was decreased in OXA group. Conclusions:Lactate-induced excessive mitochondrial division of spinal cord neurons can lead to mitochondrial dysfunction, which may be involved in the maintenance mechanism of DNP in mice.

Epstein-Barr virus (EBV) associated post-transplant lymphoproliferative disorders (PTLD) are one of the most severe complications after hematopoietic stem cell transplantation (HSCT). This study includes 31 cases of aplastic anemia (AA) patients who developed PTLD after haploidentical transplantation, summarizing their clinical characteristics and categorizing them into either rituximab monotherapy group or combination therapy group based on whether their condition improved by 1 log after a single dose of rituximab. The incidence of PTLD after HSCT in children with AA was 10.16%, and the incidence of PTLD in patients with age >10 years was significantly increased ( χ2=11.336, P=0.010). Of the 31 patients, 27 were clinically diagnosed and 4 were pathologically confirmed. Finally, 15 patients were classified into the rituximab treatment group and 15 patients into the combination treatment groups. Finally three patients died, and the 2-year overall survival rate was (89.7±5.6) %. Standard pre-treatment protocols and EBV reactivation are risk factors affecting the prognosis of PTLD. There was no statistically significant difference in the impact of the two treatment schemes on prognosis.

Objective:To investigate the efficacy and safety of venetoclax combined with the decitabine, cytarabine, and homoharringtonine (HHT) regimen and donor lymphocyte infusion (DLI) for the preventive and salvage therapy of pediatric acute myeloid leukemia (AML) /myelodysplastic syndrome (MDS) after allogeneic hematopoietic stem cell transplantation (HSCT) .Methods:A total of 29 relapsed pediatric/minimal residual disease-positive AML after HSCT were recruited at the Peking University Institute of Hematology from January 1, 2021, to June 1, 2023. They were treated with the above combination regimen and administered with DLI after 24-48 hours at the end of chemotherapy, and the treatment response and adverse reactions were regularly assessed.Results:The overall response rate (ORR) was 75.8%, CR rate was 88.9% (8/9) in the hematologic relapse group, and MRD negativity rate was 61.1% (11/18) in the MRD-positive group. The incidence of agranulocytosis, anemia, and thrombocytopenia with a classification above grade 3 were 100%, 82.7%, and 100%, respectively. The median time of the granulocyte deficiency period was 15 days. Acute graft-versus-host diseases (aGVHD) with a classification of grades Ⅲ-Ⅳ occurred in 11.1% of the patients after DLI, while moderate or severe cGVHD occurred in 7.4% of the patients. The single risk factor for ORR was MNC counts of less than 10×10 8/kg, and the relapse occurred within 100 days. At a median follow-up of 406 days, the 1-year OS was 65%, and the 1-year OS was 57% in the group with no reaction ( P=0.164) compared with 71% in the group who had an overall reaction. Conclusion:The combined regimen based on the DAC, VEN, and modified HA regimen showed a high response rate in the salvage therapy for pediatric AML after the relapse of HSCT. However, bridging to transplantation should be performed immediately after remission to result in a long survival rate.

Objective:To evaluate the role of lactate dehydrogenase in diabetic neuropathic pain (DNP) and the relationship with peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in mice.Methods:SPF-grade healthy male C57BL/6J mice, aged 6-8 weeks, weighing 18-22 g, were used to establish diabetes mellitus model by intraperitoneal injection of streptozotocin (STZ) 120 mg/kg. Twenty-four mice with diabetes mellitus were divided into 2 groups ( n=12 each) using a random number table method: DNP group and DNP + oxamate group (OXA group). Another 12 SPF-grade healthy male C57BL/6J mice were selected as control group (C group). In OXA group, oxamate 750 mg/kg was intraperitoneally injected once a day for 28 consecutive days. The equal volume of normal saline was given instead in C group and DNP group. The mechanical paw withdrawal threshold (MWT), blood glucose and body weight were measured at 3 days before STZ injection and at 1, 2, 3 and 4 weeks after STZ injection (T 0-4). After the last behavioural test was completed, blood samples were collected from the posterior orbits of anesthetized mice for determination of serum lactate concentrations. The animals were then sacrificed and the tissues from the prefrontal cortex of the brain were taken for determination of lactate content, mitochondrial membrane potential (by the JC-1), content of reactive oxygen species (ROS) (using dihydroethidium probes), and level of histone lactylation and expression of PGC-1α (by Western blot). Results:Compared with C group, the MWT was significantly decreased at T 2-4, the serum lactate concentrations, contents of lactate and ROS and level of histone lactylation were increased, the mitochondrial membrane potential was decreased, and the expression of PGC-1α was down-regulated in DNP and OXA groups ( P<0.05). Compared with DNP group, no significant change was found in blood glucose and body weight ( P>0.05), the MWT was significantly increased at T 2-4, the serum lactate concentrations, contents of lactate and ROS and level of histone lactylation were decreased, the mitochondrial membrane potential was increased, and the expression of PGC-1α was up-regulated in OXA group ( P<0.05). Conclusions:Lactate dehydrogenase promotes the development of DNP, and the mechanism is related to promotion of increase in histone lactfication and down-regulation of PGC-1α expression in the prefrontal cortex of mice.