Mast cell survival and apoptosis in organ-cultured human skin

Mast cells accumulate and persist predominantly in the upper dermis of the skin but the mechanism for this is obscure. The skin is normally exposed to external air, which is essential for the maturation of the epidermis and probably also the dermis. In order to clarify the importance of air exposure on dermal mast cells, skin organ culture at the air-liquid interface (ALI) and submerged (SM) in medium (10% fetal calf serum and Dulbecco's modification of Eagle's medium) was used to study changes in tryptase-, chymase- and Kit-positive mast cell numbers during cultivation for up to 14 days. In addition, possible apoptosis (TACS TdT in situ apoptosis detection method) in chymase-positive mast cells was studied during the culture. In the less-physiologic SM culture, the number of Kit-positive mast cells decreased rapidly on day 1-2 and tryptase-positive cells decreased markedly on day 14. This decrease in mast cell numbers can be explained by the finding that a rapid increase in the apoptosis index of mast cells was induced on day 1-2. In contrast, in the more physiologic ALI culture, the number of Kit-positive cells was sustained over 1-2 days but then decreased on day 7. In addition, tryptase-positive cells decreased steadily in number but not to the same extent as those in the SM culture. Moreover, the increase in the apoptosis index of mast cells was delayed until day 7 in the ALI culture. Addition of exogenous stem cell factor (up to 200 ng/ml) to the SM culture could not prevent the decay in tryptase- and chymase-positive cells. However, stem cell factor reduced significantly the number of Kit-positive cells already on day 2 indicating that the cells had responded. Addition of histamine (0.25 or 1 mM) or tumor necrosis factor-alpha (500 or 2000 U/ml) caused a decrease in the number of tryptase- and Kit-positive cells in the SM culture. In conclusion, a novel finding was that air exposure in the ALI culture markedly delayed the rapid apoptosis and subsequent decrease in mast cell numbers noted to occur in the SM culture. Stem cell factor could not prevent the rapid decrease in mast cell numbers. Histamine and tumor necrosis factor-alpha are possible factors promoting the decline in mast cells.     

Approval summary: imatinib mesylate for one or three years in the adjuvant treatment of gastrointestinal stromal tumors

On January 31, 2012, the U.S. Food and Drug Administration granted regular approval of imatinib mesylate tablets (Gleevec®; Novartis Pharmaceuticals Corporation, East Hanover, NJ) for the adjuvant treatment of adult patients following complete gross resection of Kit⁺ (CD117⁺) gastrointestinal stromal tumors (GISTs). The recommended dose of imatinib is 400 mg/day administered daily for 3 years. Three hundred ninety‐seven patients were enrolled in a randomized adjuvant, multicenter, open label, phase III trial comparing 12 months with 36 months of imatinib treatment. Eligible patients had one of the following: tumor diameter >5 cm and mitotic count >5 per 50 high power fields (HPFs); tumor diameter >10 cm and any mitotic count; tumor of any size with mitotic count >10/50 HPFs; or tumor ruptured into the peritoneal cavity. The primary endpoint was the recurrence‐free survival (RFS) interval. The median follow‐up for patients without an RFS event was 42 months. There were 84 (42%) RFS events in the 12‐month treatment arm and 50 (25%) RFS events in the 36‐month treatment arm. Thirty‐six months of imatinib treatment led to a significantly longer RFS interval than with 12 months of treatment. The median follow‐up for overall survival (OS) evaluation in patients still living was 48 months. Thirty‐six months of imatinib treatment led to a significantly longer OS time than with 12 months of imatinib treatment. The most common adverse reactions, as noted in previous imatinib studies, were diarrhea, fatigue, nausea, edema, decreased hemoglobin, rash, vomiting, and abdominal pain.     

Expression of c‐Kit discriminates between two functionally distinct subsets of human type 2 innate lymphoid cells

Human type 2 innate lymphoid cells (ILC2) are the only ILC subset that shows heterogeneous expression of the SCF receptor c‐Kit (CD117). Despite its use as surface marker to distinguish ILC populations, its influence on ILC2 biology has not been investigated. Here, we show that c‐Kit expression of peripheral blood ILC distinguishes two functionally distinct ILC2 subsets (c‐Kit^hi and c‐Kit^lo). When examined for their potential for functional plasticity we found that c‐Kit^lo ILC2 displayed greater potential to produce type 2 cytokines, possibly representing fully mature and lineage committed ILC2. On the other hand, c‐Kit^hi ILC2 coexpressed the ILC3‐marker and chemokine receptor CCR6 and were able to mount a significant IL‐17A response under ILC3‐promoting conditions. In addition, c‐Kit^hi ILC2 produced higher levels of IFN‐γ than c‐Kit^lo ILC2 under ILC1‐conditions. Although costimulation with SCF did not further influence ILC2 plasticity, it augmented type 2 cytokine production. We conclude that c‐Kit marks distinct subpopulations of ILC2, which has therapeutic implications for conditions in which ILC2 are involved, such as allergy and asthma.     

Immunocytochemical identification of interstitial cells of Cajal in the murine fundus using a live-labelling technique

Interstitial cells of Cajal (ICC) within the gastrointestinal (GI) tract play a critical role in the generation of electrical slow waves and as mediators of enteric motor neurotransmission. Kit immunohistochemistry has proven to be a reliable method to identify the location of these cells within the tunica muscularis and to provide information on how the distribution and density of these cells change in a variety of GI motility disorders. Because of the labile nature of Kit or its detection, ultrastructural immunocytochemistry using conventional chemical fixation methods has been difficult. We describe a novel in vivo technique to label ICC within GI tissues. Using antibodies directed against the extracellular domain of the Kit receptor, we have been able to live-label the stomach with Kit while the animal is under anaesthesia and the organ is still receiving normal blood supply. This approach provided optimum maintenance of ultrastructural features with significant binding of antibody to the Kit receptor. The loss of ICC in many human motility disorders suggests exciting new hypotheses for their aetiology. This method will prove useful to investigate the ultrastructural changes that occur in ICC networks in animal models of motility disorders that are associated with the loss of these cells.     

四种乙肝标志物ELISA试剂盒的动力学比较研究

目的 观察和评价四种ELISA试剂盒的动力学过程，并对4种试剂进行动力学评价。方法 将系列定值血清进行倍比稀释，用4种乙肝标志物试剂盒分别检测HBsAg、Anti—HBs、HBeAg、Anti—HBe和Anti—HBc，对检验结果进行统计分析。结果 4种试剂盒灵敏度、线性、本底等不尽一致，A试剂相对较好；Anti—HBe和Anti—HBc的CO值位于成长曲线上平台附近；立可读(C)试剂的灵敏度偏低。结论 ELISA反应的成长曲线与检测标本的取值范围密切相关，在确定拟合曲线前应充分考虑研究对象的分布特性；所观察试剂的质量有一定差异，特别是C试剂的灵敏度偏低。     

Study of neuropeptide Y in the plasma and skin tissue of patients with vitiligo

Vitiligoisacommondepigmentingdisorder.Thepathogenesishasnotyetbeenfullyelucidated .Therearethreeprevailingtheoriestoexplainthepathogenesisofvitil igo :theneuralhypothesis,theimmunehypothesisandthemelanocyteself destructionhypothesis .Thereisnowconv incingevidencethatneuralfactorshaveanimportantroleinthepathogenesisofvitiligo[1-6] .InordertomakefurtherstudyonthepossibleroleofneuropeptideY (NPY)inthepathogenesisofvitiligo ,wemeasuredthelevelsofNPYintheplasmaofpatientswithvitiligoandhealthyvol…     

Interstitial cells of Cajal – their role in pacing and signal transmission in the digestive system

Interstitial cells of Cajal (ICC) are located in most parts of the digestive system. Although they were discovered over 100 years ago, their function began to be unravelled only recently. Morphological observations have led to a number of hypotheses on the possible physiological roles of ICC: (1) these cells may be the source of slow electrical waves recorded in gastrointestinal (GI) muscles; (2) they participate in the conduction of electrical currents, and (3) mediate neural signals between enteric nerves and muscles. These hypotheses were supported by experiments in which the ICC‐containing layer was removed surgically, or when ICC were ablated chemically, and as a consequence the slow waves were absent. Electrophysiological experiments on isolated cells confirmed that ICC can generate rhythmic electrical activity and can also respond to messenger molecules known to be released from enteric nerves. In mice mutants deficient in ICC, or in mice treated with antibody against the protein c‐Kit, slow wave activity was impaired. These results support the role of ICC as pacemaker cells. Physiological studies have shown that ICC in certain GI regions are important for signal transmission between nerves and smooth muscle. There is evidence that pathological changes in ICC may be associated with GI motility disorders. The full interpretation of the role of ICC in disease conditions will require much further study on the physiology and pharmacology of these cells.     

检测弓形虫IgM抗体的3种试剂盒的比较分析

目的 评价用于检测弓形虫IgM抗体的3种市售的试剂盒。方法 用3种试剂盒检测125份孕妇的血清,比较各试剂盒的阳性检出率、敏感性、特异性和试验效率等。结果 125份血清经Bi、Di和So试剂盒检测,分别有12．8％、15．2％和12．0％阳性,3种试剂盒检测血清的阳性率之间无显著性差异（P＞0．05）。Bi、Di和So试剂的敏感性和特异性分别为88．9％与100％、100％与99．1％和83．3％与100％,试验效率分别为98．4％、99．2％和97．6％。用WHO国际生物标准化实验室的抗号形虫血清标准品定量测得3种试剂盒的灵敏度都是0．31IU／ml。Bi试剂盒与Di试剂盒的总符合率为97．6％;Di试剂盒与So试剂盒的总符合率为96．8％;Bi试剂盒与So试剂盒的总符合率为97．6％。结论 这3种试剂盒都能用于弓形虫IgM抗体的常规普筛和血清学诊断。