[The effect of platelet infusion on the repair of bone marrow hematopoietic niche damage in mice induced by (60)Co radiation and hematopoietic reconstruction after bone marrow transplantation].

Objective: To observe the effect of platelets on hematopoietic stem cell (HSCs) implantation in mice with radiation-induced bone marrow injury and bone marrow transplantation models. Methods: ①Male C57BL/6 mice were divided into a single irradiation group and a radiation infusion group after receiving (60)Co semimyeloablative irradiation for 18-10 weeks. The irradiation infusion group received 1×10(8) platelets expressing GFP fluorescent protein. ② The allogeneic bone marrow transplantation model was established. The experimental groups included the simple transplantation group (BMT) and the transplantation infusion group (BMT+PLT). The BMT group was infused through the tail vein only 5 × 10(6) bone marrow cells, the BMT+PLT group needs to be infused with bone marrow cells at the same time 1× 10(8) platelets. ③ Test indicators included peripheral blood cell and bone marrow cell counts, flow cytometry to detect the proportion of hematopoietic stem cell (HSC) and hematopoietic progenitor cells, bone marrow cell proliferation and apoptosis, and pathological observation of vascular niche damage and repair. Results: ①On the 3rd, 7th, 14(th), and 21st days after irradiation, the bone marrow cell count of the infusion group was higher than that in the single irradiation group (P<0.05), and the peripheral blood cell count was also higher. A statistically significant difference was found between the white blood cell count on the 21st day and the platelet count on the 7th day (P<0.05). In the observation cycle, the percentage of bone marrow cell proliferation in the infusion group was higher, while the percentage of apoptosis was lower. ② The results of bone tissue immunofluorescence after irradiation showed that the continuity of hematopoietic niche with red fluorescence was better in the irradiation infusion group. ③The chimerism percentage in the BMT+PLT group was always higher than that in the BMT group after transplantation.④ The BMT+PLT group had higher bone marrow cell count and percentage of bone marrow cell proliferation on the 7th and 28th day after transplantation than that in the BMT group, and the percentage of bone marrow cell apoptosis on the 14th day was lower than that in the BMT group (P<0.05). After the 14th day, the percentage of stem progenitor cells in the bone marrow cells of mice was higher than that in the BMT group (P<0.05). ⑤The immunohistochemical results of bone marrow tissue showed that the continuity of vascular endothelium in the BMT+PLT group was better than that in the BMT group. Conclusion: Platelet transfusion can alleviate the injury of vascular niche, promotes HSC homing, and is beneficial to hematopoietic reconstruction.

Nirmatrelvir increases blood tacrolimus concentration in COVID-19 patients as determined by UHPLC-MS/MS method.

OBJECTIVE: Transplant recipients have a higher risk of SARS-CoV-2 infection owing to the use of immunosuppressive drugs like tacrolimus (FK506). FK506 and nirmatrelvir (NMV) (an anti-SARS-CoV-2 drug) are metabolized by cytochrome P450 3A4 and may have potential drug-drug interactions. It is important to determine the effect of NMV on FK506 concentrations. PATIENTS AND METHODS: Following protein precipitation from blood, FK506 and its internal standard (FK506-13C,2d4) were detected by ultra-high performance liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS). Total 22 blood samples (valley concentrations) from two coronavirus disease 2019 (COVID-19) patients were collected and analyzed for FK506 concentrations. RESULTS: Blood levels of FK506 (0.5-100 ng/mL) showed good linearity. The UHPLC-MS/MS method was validated with intra- and inter-batch accuracies of 104.55-107.85%, and 99.52-108.01%, respectively, and precisions of < 15%. Mean blood FK506 concentration was 12.01 ng/mL (range, 3.15-33.1 ng/mL). Five-day co-administration with NMV increased the FK506 concentrations from 3.15 ng/mL to 33.1 ng/mL, returning to 3.36 ng/mL after a 9-day-washout. CONCLUSIONS: We developed a simple quantification method for therapeutic drug monitoring of FK506 in patients with COVID-19 using UHPLC-MS/MS with protein precipitation. We found that NMV increased FK506 blood concentration 10-fold. Therefore, it is necessary to re-consider co-administration of FK506 with NMV.

[Clinical effect and safety of pegylated interferon-α-2b injection (Y shape, 40 kD) in treatment of HBeAg-positive chronic hepatitis B patients].

Objective: To investigate the clinical effect and safety of long-acting pegylated interferon-α-2b (Peg-IFN-α-2b) (Y shape, 40 kD) injection (180 µg/week) in the treatment of HBeAg-positive chronic hepatitis B (CHB) patients, with standard-dose Peg-IFN-α-2a as positive control. Methods: This study was a multicenter, randomized, open-label, and positive-controlled phase III clinical trial. Eligible HBeAg-positive CHB patients were screened out and randomized to Peg-IFN-α-2b (Y shape, 40 kD) trial group and Peg-IFN-α-2a control group at a ratio of 2:1. The course of treatment was 48 weeks and the patients were followed up for 24 weeks after drug withdrawal. Plasma samples were collected at screening, baseline, and 12, 24, 36, 48, 60, and 72 weeks for centralized detection. COBAS® Ampliprep/COBAS® TaqMan® HBV Test was used to measure HBV DNA level by quantitative real-time PCR. Electrochemiluminescence immunoassay with Elecsys kit was used to measure HBV markers (HBsAg, anti-HBs, HBeAg, anti-HBe). Adverse events were recorded in detail. The primary outcome measure was HBeAg seroconversion rate after the 24-week follow-up, and non-inferiority was also tested. The difference in HBeAg seroconversion rate after treatment between the trial group and the control group and two-sided confidence interval (CI) were calculated, and non-inferiority was demonstrated if the lower limit of 95% CI was > -10%. The t-test, chi-square test, or rank sum test was used according to the types and features of data. Results: A total of 855 HBeAg-positive CHB patients were enrolled and 820 of them received treatment (538 in the trial group and 282 in the control group). The data of the full analysis set showed that HBeAg seroconversion rate at week 72 was 27.32% in the trial group and 22.70% in the control group with a rate difference of 4.63% (95% CI -1.54% to 10.80%, P = 0.1493). The data of the per-protocol set showed that HBeAg seroconversion rate at week 72 was 30.75% in the trial group and 27.14% in the control group with a rate difference of 3.61% (95% CI -3.87% to 11.09%, P = 0.3436). 95% CI met the non-inferiority criteria, and the trial group was non-inferior to the control group. The two groups had similar incidence rates of adverse events, serious adverse events, and common adverse events. Conclusion: In Peg-IFN-α regimen for HBeAg-positive CHB patients, the new drug Peg-IFN-α-2b (Y shape, 40 kD) has comparable effect and safety to the control drug Peg-IFN-α-2a.

[Utility of hemoglobin A1c for diagnosing metabolic syndrome in Chinese subjects over 50 years old].

Objective: To evaluate glycated hemoglobing A1c (HbA1c) in diagnosing metabolic syndrome (MS) in Chinese subjects aged over 50 years. Methods: A community-based cross-sectional survey was conducted between October 2010 and January 2011 in Shipai community, Guangzhou. A total of 1 494 subjects aged over 50 years were investigated. Questionnaire survey and physical examination were performed among all participants. Fasting blood samples were obtained to measure plasma glucose (FPG), blood lipids and HbA1c. MS was defined by the criteria of International Diabetes Federation (IDF), National Cholesterol Education Program-Adult Treatment Panel Ⅲ (ATP Ⅲ)(2005) and Chinese Diabetes Society (CDS), respectively. Receiver operating characteristic (ROC) curves were plotted to explore the accuracy of HbA1c for diagnosing MS. Results: After excluding subjects with missing data, the remaining 1 473 subjects had a median age of 61 years (55-68 years). An HbA1c threshold of 6.1% yielded the highest combination of sensitivity (52.1%) and specificity (84.3%) for diagnosing MS. Using HbA1c≥5.7% as definition of dysglycemia, the prevalence of MS (IDF), MS (ATP Ⅲ) and MS (CDS) were 48.7%, 57.1% and 50.8%, respectively. The κ coefficients were 0.853, 0.768 and 0.730, respectively. Using HbA1c≥6.1% as definition of dysglycemia, the prevalences of MS (IDF), MS (ATP Ⅲ) and MS (CDS) were 41.2%, 45.8% and 39.1%, respectively. The κ coefficients were 0.923, 0.880 and 0.881, respectively. The optimal HbA1c threshold with the highest level of agreement according to IDF, ATP Ⅲ and CDS criteria were 6.1%, 6.3% and 6.3%, respectively. Conclusions: An HbA1c threshold of 6.1% showed a high specificity for diagnosing MS in Chinese subjects aged over 50 years in community-based setting. The optimal HbA1c threshold may vary according to different criteria and populations.

[The function of NLRP1 in noninfectious pulmonary injury following allogeneic hematopoietic stem cell transplantation].

Objective: To explore the function of NLRP1 in noninfectious pulmonary injury (nonIPI) after allogeneic stem cell transplantation (allo-HSCT) . Methods: In this study, we established the model of allo-HSCT with C57BL/6 and NLRP(-/-) mouse as recipients. Chimera rate was measured by flow cytometry. The HE staining was used to observe the pathology changes in the lungs. NLRP1 and relevant inflammatory proteins were measured by Western Blot. Results: On the day 14 after allo-HSCT, the chimera rate was more than 96%, HSCs of donors had been successfully transplanted into recipients. HE staining showed that nonIPI occurred after allo-HSCT. The degrees of injuries reached the peak on day 21. In addition, the expressions of MPO, NLRP1, p20, Mature-IL-1ß and Mature-IL-18 had same tends with the degrees of nonIPI. When we knocked out NLRP1 gene of recipients, the degrees of nonIPI reduced and the expressions of MPO, p20, Mature-IL-1ß and Mature-IL-18 were less than in non-knockout group. Conclusion: allo-HSCT could cause nonIPI and high expressions of MPO, p20, IL-1ß, IL-18, NLRP1. Knocking out NLRP1 gene could alleviate the degrees of nonIPI and reduce the expressions of relevant inflammatory proteins, indicating that NLRP1 might be one of factors contributed to nonIPI after allo-HSCT.

[Effects of allogeneic hematopoietic stem cell transplantation in combination with infusion of endothelial progenitor cells on bone marrow inflammatory injury].

Objective: To explore effects of allogeneic hematopoietic stem cell transplantation (HSCT) in combination with infusion of endothelial progenitor cells (EPC) on bone marrow inflammatory injury. Methods: 6-8 weeks BALB/c (H-2K(d)) mice after lethal dose of irradiation (TBI) were subjected to allogeneic bone marrow transplantation (BMT group) or co-transplantation of EPC (EPC group) . Samples of bone marrow cells of mice in each group on days 7,14,21,28 after transplantation were obtained to detect EPC cultural and cell chimeric rates by flow cytometer. Mice were sacrificed on days 7, 14, 21 and 28 post HSCT to analyze bone marrow pathology by H&E staining, the infiltration of macrophages and neutrophils by Western blot, validation expression levels of inflammatory complexes nlrp1、nlrp6 and its downstream molecules casepase-1 by Q-PCR and Western blot. Results: Cell chimeric rate on day 7 after transplantation in EPC group[ (91.65±2.77) %] was significantly higher than in BMT group[ (83.69±1.26) %]. Alleviated osteomyelitis injury and inflammatory cell infiltration in EPC group were observed when compared with BMT mice. Also significant reductions of the levels of nlrp1、nlrp6、casepase-1 transcription complexes in EPC mice were noted when compared with BMT ones. Conclusion: Co-transplantation of HSC and EPC could alleviate inflammatory cell infiltration and activation of the complex to promote the repair of bone marrow.

[Effect of continuous subcutaneous insulin infusion on the evaluation of ß cell function].

OBJECTIVE: To evaluate the impact of continuous subcutaneous insulin infusion (CSII) on ß-cell function assessment. METHODS: One hundred and twenty-five patients with type 2 diabetes (T2DM) admitted to Third Affiliated Hospital of Sun Yat-sen University treated with CSII were enrolled from May to December 2015. Blood samples were collected to measure their fasting blood glucose, haemoglobin A1c, blood lipids and plasma C peptide levels (fasting, 30 min and 120 min after a mixed meal) on the next day of their admission before CSII started. When patients achieved the target of fasting capillary glucose ≤ 7.0 mmol/L, C-peptide levels (0 min, 30 min and 120 min after a mixed meal) were measured. Then CSII were stopped at 10 pm with the same tests repeated on the next day. RESULTS: Compared with those measured before CSII [0 min: (0.35±0.20) nmol/L, 30 min: (0.57±0.31) nmol/L, 120 min: (0.84±0.54) nmol/L], C-peptide levels after stopping CSII at all time points [0 min: (0.41±0.16) nmol/L, 30 min: (0.71±0.33) nmol/L, 120 min: (1.37±0.75) nmol/L] increased (P=0.015, P=0.005, P<0.001) even glucose control was achieved, but significantly decreased immediately before CSII was stopped [0 min: (0.23±0.13)nmol/L, 30 min: (0.39±0.26) nmol/L, 120 min: (0.67± 0.50) nmol/L] (P<0.001, P<0.001, P=0.023). The C-peptide after stopping CSII increased to 141% (0 min), 127% (30 min) and 219% (120 min) respectively compared to those before stopping CSII. CONCLUSION: CSII therapy should be stopped for accurate evaluation of ß-cell function due to its"ß-cell rest"effect in T2DM.

Retrospective analysis of early outcomes after a single-armed suture technique for microsurgical intussusception vasoepididymostomy.

Longitudinal intussusception microsurgical vasoepididymostomy (LIVE) increases the patency rate in men with epididymal obstructive azoospermia (EOA). Here, we retrospectively analyzed the early outcomes of our modified single-armed suture technique for LIVE in men with EOA. From February 2012 to November 2013, 51 men received the modified technique and 39 men provided at least one post-operative semen sample. The mean age was 31.4 years old for the men and 29.2 years old for their female partners. The mean duration of obstruction was 34.3 months. Patency was noted in 24 (61.5%) men and pregnancy was reported in 15 (38.5%) female partners. Motile spermatozoa in the epididymal fluid were observed intraoperatively in 14 (58.3%) patent men and 3 (20%) non-patent men, respectively (p < 0.05). In the patent cohort, the mean ages of the pregnant and non-pregnant female partners were 26.5 and 32.7 years old, respectively (p < 0.05). Our modified technique resulted in favorable patency and pregnancy rates in this study. Sperm motility in epididymal fluid and female partner age were important factors associated with the patency and pregnancy rates.

Tunable dielectric properties of ferrite-dielectric based metamaterial.

A ferrite-dielectric metamaterial composed of dielectric and ferrite cuboids has been investigated by experiments and simulations. By interacting with the electromagnetic wave, the Mie resonance can take place in the dielectric cuboids and the ferromagnetic precession will appear in the ferrite cuboids. The magnetic field distributions show the electric Mie resonance of the dielectric cuboids can be influenced by the ferromagnetic precession of ferrite cuboids when a certain magnetic field is applied. The effective permittivity of the metamaterial can be tuned by modifying the applied magnetic field. A good agreement between experimental and simulated results is demonstrated, which confirms that these metamaterials can be used for tunable microwave devices.

Suppression of human peripheral blood lymphocyte proliferation by immortalized mesenchymal stem cells derived from bone marrow of Banna Minipig inbred-line.

This study sought to investigate whether mesenchymal stem cells (MSC) derived from Banna Minipig Inbred-line (BMI-MSC) suppressed human peripheral blood lymphocyte (hPBLs) proliferation in a one-way mixed lymphocyte reaction system. BMI-MSC failed to stimulate proliferative responses by hPBLs, which were activated by allogenic endothelial cells, BMI-PBLs and non-specific mitogenic stimuli. Furthermore, BMI-MSC also suppressed proliferation of hPBLs stimulated by mismatched allogenic, as well as xenogenic PBLs, and the mitogenic stimulus ConA. The suppression occurred in dose-dependent fashion when the ratio of hPBLs to BMI-MSC varied from 1 to 5 fold; fewer, BMI-MSC (0.001 to 0.01 times) showed no obvious suppression. When BMI-MSC were added to hPBLs stimulated for 72 hours, the proliferative suppression was still evident. Addition of anti-FasL or anti-TGF-beta1 antibody attenuated the proliferative suppression, while antibody against IL-10 had no effect on it. Further immunofluorescence analysis demonstrated that FasL and TGF-beta1 constitutively expressed BMI-MSC. These findings suggest that BMI-MSC suppress hPBLs proliferation relying on FasL and TGF-beta1 mediated pathways.