变形链球菌耐氟菌株与亲代菌株质子移位膜ATP酶活性的比较

目的:通过测定并比较变形链球菌耐氟菌株及其亲代菌株体内质子移位膜ATP酶的活性,以阐明耐氟菌株耐酸能力提高的原因。方法:将变链菌株Ingbritt及其耐氟突变株Ingbritt-FR通过甲苯处理,2个循环的液氮冷冻和37℃解冻,制成透性细胞。将透性细胞悬液加到含有10mmol/LMgSO4的50mmol/LTris-maleate测试缓冲液中(pH6.0),加温至37℃,再加入5mmol/LATP(pH6.0)起动反应。分别于10、20、60min取样,测定样品中水解ATP所释出的无机磷量。采用磷钼酸比色法在紫外分光光度计上进行比色分析(660nm),所得数据采用双因素方差分析。结果:在10、20和60min时,耐氟菌株H+-ATP酶活性分别为308.48、136.67和82.80μmolPi/g细胞干重/min,显著高于亲代菌株的相应酶活性:104.77,、64.69和30.70(P<0.01)。随时间推移,两类菌株的H+-ATP酶活性均逐渐降低,在酶的作用时间差别上有统计学意义(P<0.01)。结论:耐氟菌株ATP酶活性增高为其耐酸性增高的原因;H+-ATP酶活性及耐酸性的增高将会增加变链菌耐氟菌株的致龋潜能。     

老年人高龋患者牙菌斑中变形链球菌临床分离株耐酸能力的研究

目的:分析老年人高龋患者牙菌斑中,变形链球菌临床分离株(血清型C)在酸性条件下生存的耐酸能力。方法:体外培养从老年人高龋患者、无龋者牙菌斑中分离的101种不同基因型变形链球菌株临床分离株(血清型C),检测菌株在不同的pH条件下的耐酸能力。结果:老年人高龋患者口腔中分离出的变形链球菌临床分离株耐酸能力明显高于无龋组,与国际参考菌株无明显的统计学差异。同时研究发现,在老年人高龋患者同一个体的口腔中,变形链球菌临床分离株耐酸能力存在明显差异。结论:老年人高龋患者牙菌斑中变形链球菌临床分离株(血清型C)的高致龋性,与其携带有耐酸能力强的菌株关系密切。     

胆固醇的细菌内毒素检查方法研究

目的 为难溶性辅料胆固醇(供注射用)建立细菌内毒素检测方法。方法 通过筛选出适合溶解胆固醇的有机溶剂,并经过9种排除干扰的方法筛选,采用凝胶法和动态浊度法进行干扰试验,排除了有机溶剂和胆固醇对内毒素检查法的干扰,最终建立了胆固醇的细菌内毒素质量控制方法。检测条件：取胆固醇用无水乙醇配制成20 mg·mL-1溶液,用0.5 mg·mL-1聚氧乙烯(35)蓖麻油水溶液代替细菌内毒素检查用水稀释100倍,按内毒素检查法动态浊度法检测。结果 3批样品使用2个厂家的动态浊度法鲎试剂的回收率均在50%～200%,并且内毒素检测值均<0.1 EU·mg-1。如使用凝胶法,该品种只能使用1个厂家最高灵敏度的试剂进行检测。因此,胆固醇不建议使用凝胶法进行检测。结论 建立了胆固醇(供注射用)细菌内毒素动态浊度法检测方法,用于质量控制。     

维生素A棕榈酸酯原料细菌内毒素检查方法研究

目的：建立检查维生素A棕榈酸酯进行细菌内毒素检查法。方法：维生素A棕榈酸酯以无水乙醇为溶剂溶解,再用细菌内毒素检查用水稀释制成乳浊液,依照《中国药典》2020年版(四部)1143细菌内毒素检查法,对维生素A棕榈酸酯细菌内毒素检查法进行干扰试验预试验和干扰试验,同时增加细菌内毒素回收干扰试验预试验和干扰试验。结果：维生素A棕榈酸酯在实验过程中出现的复析、乳浊现象对细菌内毒素检查无影响,维生素A棕榈酸酯在0.015625mg.ml-1^浓度下对细菌内毒素检查无干扰作用。结论：本法可用于维生素A棕榈酸酯细菌内毒素的质量控制。     

Markers of insulin resistance in Polycystic ovary syndrome women: An update

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, affecting 5%-10% of women of reproductive age. The importance of this syndrome lies in the magnitude of associated comorbidities: infertility, metabolic dysfunction, cardiovascular disease (CVD), plus psychological and oncological complications. Insulin resistance (IR) is a prominent feature of PCOS with a prevalence of 35%-80%. Without adequate management, IR with compensatory hyperinsulinemia contributes directly to reproductive dysfunction in women with PCOS. Furthermore, epidemiological data shows compelling evidence that PCOS is associated with an increased risk of impaired glucose tolerance, gestational diabetes mellitus and type 2 diabetes. In addition, metabolic dysfunction leads to a risk for CVD that increases with aging in women with PCOS. Indeed, the severity of IR in women with PCOS is associated with the amount of abdominal obesity, even in lean women with PCOS. Given these drastic implications, it is important to diagnose and treat insulin resistance as early as possible. Many markers have been proposed. However, quantitative assessment of IR in clinical practice remains a major challenge. The gold standard method for assessing insulin sensitivity is the hyperinsulinemic euglycemic glucose clamp. However, it is not used routinely because of the complexity of its procedure. Consequently, there has been an urgent need for surrogate markers of IR that are more applicable in large population-based epidemiological investigations. Despite this, many of them are either difficult to apply in routine clinical practice or useless for women with PCOS. Considering this difficulty, there is still a need for an accurate marker for easy, early detection and assessment of IR in women with PCOS. This review highlights markers of IR already used in women with PCOS, including new markers recently reported in literature, and it establishes a new classification for these markers.     

中药肠内营养剂干预糖耐量低减的临床观察

目的:观察中药肠内营养剂干预糖耐量低减(impaired glucose tolerance,IGT)的临床疗效。方法:将300例IGT患者随机分为对照组和研究组,每组各150例。对照组在临床标准化诊疗方案进行降血糖、降血脂、减肥及运动治疗,研究组在对照组的基础上给予特定主食中辨证加入中药细粉组成中药肠内营养剂。比较两组患者的临床疗效及治疗前后中医证候积分变化情况,观察两组患者治疗前后FPG、餐后2 h血糖(2h blood sugar,2h PG)、糖化血红蛋白(glycosylated hemoglobin,Hb A1c)、低血糖发生率、血清三酰甘油(three acyl glycerol,TG)、血清总胆固醇(total cholesterol,TC)、血尿素氮(blood urea nitrogen,BUN)、血肌酐(serum creatinine,Scr)、血尿酸(uric acid,UA)、谷丙转氨酶(glutamic pyruvic transaminase,ALT)、体质量指数(body mass index,BMI)及腰围。结果:对照组有效率为85.3%,研究组有效率为96.7%,两组患者临床疗效比较,差异具有统计学意义(P0.05)。两组患者治疗后FPG、2h PG、Hb A1c、低血糖发生率、TG、TC、BMI及腰围均低于治疗前,且研究组低于对照组,差异均有统计学意义(P0.05)。结论:中药肠内营养剂干预IGT,可改善不良指标,并且未见肝肾功能的损害,糖尿病发病率明显降低。     

Immunosuppressive and metabolic agents that influence allo- and xenograft survival by in vivo expansion of T regulatory cells

The transplanted organs or cells survive if the recipient receives adequate long-term immunosuppressive therapy. Immunosuppressive therapy combined with cell-based strategies (eg, regulatory T cell [Treg]-based therapy) promotes graft survival. A combination of Treg-based therapy and minimal or no immunosuppressive drug therapy would have the potential to minimize the risks of the complications and side effects of these drugs. Fortunately, some immunosuppressive and other agents not only impede the effector T cell response, but also help generate new CD4⁺ Tregs from conventional effector T cells. These agents include IL-2, TGF-β, agents that block the CD40/CD40L costimulation pathway, mTOR inhibitors, and histone deacetylase inhibitors. Consequently, a state of relative unresponsiveness to the transplanted organ may be induced through the expansion of Tregs. We here review the effect of these various agents on expansion of CD4⁺ Tregs in allo- and xenotransplantation. The expansion of Tregs might allow a dose reduction of the standard immunosuppressive drugs.     

Trained immunity in organ transplantation

Consistent induction of donor‐specific unresponsiveness in the absence of continuous immunosuppressive therapy and toxic effects remains a difficult task in clinical organ transplantation. Transplant immunologists have developed numerous experimental treatments that target antigen‐presentation (signal 1), costimulation (signal 2), and cytokine production (signal 3) to establish transplantation tolerance. While promising results have been obtained using therapeutic approaches that predominantly target the adaptive immune response, the long‐term graft survival rates remain suboptimal. This suggests the existence of unrecognized allograft rejection mechanisms that contribute to organ failure. We postulate that trained immunity stimulatory pathways are critical to the immune response that mediates graft loss. Trained immunity is a recently discovered functional program of the innate immune system, which is characterized by nonpermanent epigenetic and metabolic reprogramming of macrophages. Since trained macrophages upregulate costimulatory molecules (signal 2) and produce pro‐inflammatory cytokines (signal 3), they contribute to potent graft reactive immune responses and organ transplant rejection. In this review, we summarize the detrimental effects of trained immunity in the context of organ transplantation and describe pathways that induce macrophage training associated with graft rejection.     

Pancreatic islets engineered with a FasL protein induce systemic tolerance at the induction phase that evolves into long‐term graft‐localized immune privilege

We have previously shown that pancreatic islets engineered to transiently display a modified form of FasL protein (SA‐FasL) on their surface survive indefinitely in allogeneic recipients without a need for chronic immunosuppression. Mechanisms that confer long‐term protection to allograft are yet to be elucidated. We herein demonstrated that immune protection evolves in two distinct phases; induction and maintenance. SA‐FasL‐engineered allogeneic islets survived indefinitely and conferred protection to a second set of donor‐matched, but not third‐party, unmanipulated islet grafts simultaneously transplanted under the contralateral kidney capsule. Protection at the induction phase involved a reduction in the frequency of proliferating alloreactive T cells in the graft‐draining lymph nodes, and required phagocytes and TGF‐β. At the maintenance phase, immune protection evolved into graft site‐restricted immune privilege as the destruction of long‐surviving SA‐FasL‐islet grafts by streptozotocin followed by the transplantation of a second set of unmanipulated islet grafts into the same site from the donor, but not third party, resulted in indefinite survival. The induced immune privilege required both CD4⁺CD25⁺Foxp3⁺ Treg cells and persistent presence of donor antigens. Engineering cell and tissue surfaces with SA‐FasL protein provides a practical, efficient, and safe means of localized immunomodulation with important implications for autoimmunity and transplantation.     

Donor‐specific chimeric antigen receptor Tregs limit rejection in naive but not sensitized allograft recipients

Cell therapy with autologous donor‐specific regulatory T cells (Tregs) is a promising strategy to minimize immunosuppression in transplant recipients. Chimeric antigen receptor (CAR) technology has recently been used successfully to generate donor‐specific Tregs and overcome the limitations of enrichment protocols based on repetitive stimulations with alloantigens. However, the ability of CAR‐Treg therapy to control alloreactivity in immunocompetent recipients is unknown. We first analyzed the effect of donor‐specific CAR Tregs on alloreactivity in naive, immunocompetent mice receiving skin allografts. Tregs expressing an irrelevant or anti‐HLA‐A2‐specific CAR were administered to Bl/6 mice at the time of transplanting an HLA‐A2⁺ Bl/6 skin graft. Donor‐specific CAR‐Tregs, but not irrelevant‐CAR Tregs, significantly delayed skin rejection and diminished donor‐specific antibodies (DSAs) and frequencies of DSA‐secreting B cells. Donor‐specific CAR‐Treg–treated mice also had a weaker recall DSA response, but normal responses to an irrelevant antigen, demonstrating antigen‐specific suppression. When donor‐specific CAR Tregs were tested in HLA‐A2‐sensitized mice, they were unable to delay allograft rejection or diminish DSAs. The finding that donor‐specific CAR‐Tregs restrain de novo but not memory alloreactivity has important implications for their use as an adoptive cell therapy in transplantation.