Extracellular accumulation of bioactive substances during preparation and storage of various platelet concentrates

BACKGROUND: Side effects of platelet transfusion may be associated with infusion of bioactive substances. We therefore studied extracellular accumulation of histamine, plasminogen activator inhibitor (PAI)-1, vascular endothelial growth factor (VEGF), and interleukin (IL)-6 during preparation and storage of various platelet concentrates. METHODS: Twenty buffy-coat-derived platelet pools (BCPC) were prepared and stored in platelet additive solutions (PAS). Twelve apheresis platelet (APC) units were prepared using the COBE Spectra LRS, and 14 were prepared using the Fenwal Amicus Separator. After preparation half of the content was drawn from each APC unit. The normal ranges of the substances were determined in plasma from all donors, and the extracellular concentrations of the substances were determined in supernatants collected on days 0, 1, 3, 5, and 7 of storage from all platelet preparations. RESULTS: The platelet counts were not significantly different in BCPC units and APC units. The BCPC units had a significantly higher white cell count than the APC units (P < 0.0001), but the count was significantly higher in the Amicus APC units than in the COBE APC units (P < 0.0001). The extracellular histamine concentration was significantly (P < 0.001) increased in BCPC units after preparation and without further increase during storage, while there was no accumulation of histamine in APC units. After preparation the PAI-1 concentration was significantly (P < 0.02) higher in BCPC units than in APC units, but during storage PAI-1 increased significantly (P < 0.05) more in APC units than in BCPC units. Similarly, VEGF concentration was significantly (P < 0.05) higher in BCPC units than in APC units after preparation. During storage, however, VEGF increased more in BCPC units compared with COBE Spectra APC units (P < 0.05), but compared with Amicus Separator APC units only for the first 3 days of storage. At days 5 and 7 of storage the VEGF concentration was significantly higher in the Amicus APC units than in the COBE APC units (P < 0.05). IL-6 was not detectable in any of the concentrates after preparation or during storage. CONCLUSION: Platelet concentrates prepared by the apheresis method may contain less white cell derived bioactive substances than platelet concentrates prepared by the buffy-coat method. However, a substantial storage time dependent platelet derived bioactive substance accumulation takes place in all platelet concentrates tested, presumably due to platelet disintegration.     

血浆纤溶酶原激活物抑制物1与胰岛素抵抗的相关性研究

目的：探讨血浆纤溶酶原激活物抑制物1（plasminogen activitor inhibitor one,PAI-1)活性及其基因启动子区4G／5G多态性与胰岛素抵抗综合征的关系。方法：应用等位基因特异性PCR扩增技术，对胰岛素抵抗综合征患者（160例）和对照组（90例）PAI－1 4G／5G多态位点的基因型进行检测，用发色底物法测血浆PAI－1活性。结果：（1）胰岛不抵抗综合综合患者PAI－1活性明显升高，空腹胰岛素，空腹血糖，甘油三酯与PAI－1活性升高密切相关（P＜0．01）。（2）对照组和胰岛素抵抗综合征患者，4G／5G基因型频率分别为0．52和0．48，两组比较无明显差异（P＞0．05），但胰岛素抵抗综合征不同基因型者PAI－1活性差异显著（P＜0．01），4G／4G基因型者PAI－1活性高于4G／5G和5G／5G基因型者（P＜0．01）。（3）血糖、甘油三酯对PAI－1活性的调节受基因型的影响。4G／4G基因型者血糖，甘油三酯与PAI－1活性密切相关（P＜0．01），而4G／5G和5G／5G基因型者血糖。甘油三酯与PAI－1活性无明显相关（P＞0．05）。（4）胰岛素对PAI－1活必的影响无基因型依赖性。结论：PAI－1活性升高是胰岛素抵抗综合征患进的特征之一，免疫反应性胰岛素，血糖，甘油三酯与PAI－1活性升高有关，血糖，甘油三酯对PAI－1活性的调节存在明显的基因型依赖性。     

Macrophage migration inhibitory factor stimulated by Helicobacter pylori increases proliferation of gastric epithelial cells

AIM: Helicobacter pylori ( H pylorl) is associated with increased gastric inflammatory and epithelial expression of macrophage migration inhibitory factor (MIF) and gastric epithelial cell proliferation. This study aimed at determining whether H pyloridirectly stimulates release of MIF in monocytes, whether the cag pathogenicity island (PAI) is involved for this function, and whether MIF stimulated by H pylori increases gastric epithelial cell proliferation in vitro. METHODS: A cytotoxic wild-type Hpyloristrain (TN2), its three isogenic mutants (TN2Acag, TN2AcagA and TN2AcagE) were co-cultured with cells of a human monocyte cell line, THP-1, for 24 h at different organism/cell ratios. MIF in the supernatants was measured by an ELISA. Cells of a human gastric cancer cell line, MKN45, were then co-cultured with the supernatants, with and without monoclonal anti-MIF antibody for 24 h. The cells were further incubated for 12 h after addition of 3H-thymidine, and the levels of incorporation of 3H-thymidine were measured with a liquid scintillation counter. RESULTS: The wild-type strain and the isogenic mutants, TN2ΔcagA and TN2ΔcagE, increased MIF release at organism/cell ratios of 200/1 and 400/1, but not at the ratios of 50/1 and 100/1. However, the mutant TN2Δcag did not increase the release of MIF at any of the four ratios.^ 3H-thymidine readings for MKN-45 cells were significantly increased with supernatants derived from the wild-type strain and the mutants TN2ΔcagA and TN2ΔcagE, butnot from the mutant TN2A cag. Moreover, in the presence of monoclonal anti-MIF antibody, the stimulatory effects of the wild-type strain on cell proliferation disappeared. CONCLUSION: H pylori stimulates MIF release in monocytes, likely through its cag PAI, but not related to cagA or cagE. H pylori-stimulated monocyte culture supernatant increases gastric cell proliferation, which is blocked by anti-MIF antibody, suggesting that MIF plays an important role in H pylori-induced gastric epithelial cell proliferation.     

Renin inhibition in hypertension

Fifty years ago, investigators identified renin inhibition as the preferred pharmacologic approach to blockade of the renin-angiotensin system. Renin is a monospecific enzyme that catalyzes the rate-limiting step in the synthesis of angiotensin II. Amplified enzymatic activity and additional physiological effects occur when renin and pro-renin bind to the (pro)renin receptor. Until very recently, development of clinically effective renin inhibitors remained elusive. Molecular modeling was used to develop aliskiren, a potent, low-molecular-weight, nonpeptide, direct renin inhibitor with sufficient bioavailability to produce sustained suppression of plasma renin activity after oral administration. In patients with hypertension, aliskiren produces dose-dependent blood pressure (BP) reduction and 24-h BP control up to a dose of approximately 300 mg once daily; at these doses, aliskiren shows placebo-like tolerability. Its antihypertensive potency is approximately equivalent to that of angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and diuretics. After abrupt withdrawal, persistent BP reduction and prolonged suppression of plasma renin activity is observed. When combined with diuretics, fully additive BP reduction is seen. When given with an angiotensin receptor blocker, aliskiren produces significant additional BP reduction indicative of complimentary pharmacology and more complete renin-angiotensin system blockade. Clinical trials are currently underway assessing the effects of aliskiren combined with an angiotensin receptor blocker on intermediate markers of end organ damage, and long-term end point trials are planned. The results of these studies will ultimately determine the place of renin inhibition and aliskiren in the treatment of hypertension and related cardiovascular disorders. The effect of aliskiren on receptor-bound renin and pro-renin is the subject of active investigation.     

Randomized controlled trial to improve childhood immunization adherence in rural Pakistan: redesigned immunization card and maternal education

Objective A substantial dropout from the first dose of diphtheria‐tetanus‐pertussis (DTP1) to the 3rd dose of DTP (DTP3) immunization has been recorded in Pakistan. We conducted a randomized controlled trial to assess the effects of providing a substantially redesigned immunization card, centre‐based education, or both interventions together on DTP3 completion at six rural expanded programme on immunization (EPI) centres in Pakistan. Methods Mother‐child pairs were enrolled at DTP1 and randomized to four study groups: redesigned card, centre‐based education, combined intervention and standard care. Each child was followed up for 90 days to record the dates of DTP2 and DTP3 visits. The study outcome was DTP3 completion by the end of follow‐up period in each study group. Results We enrolled 378 mother–child pairs in redesigned card group, 376 in centre‐based education group, 374 in combined intervention group and 378 in standard care group. By the end of follow‐up, 39% of children in standard care group completed DTP3. Compared to this, a significantly higher proportion of children completed DTP3 in redesigned card group (66%) (crude risk ratio [RR] = 1.7; 95% CI = 1.5, 2.0), centre‐based education group (61%) (RR = 1.5; 95% CI = 1.3, 1.8) and combined intervention group (67%) (RR = 1.7; 95% CI = 1.4, 2.0). Conclusions Improved immunization card alone, education to mothers alone, or both together were all effective in increasing follow‐up immunization visits. The study underscores the potential of study interventions’ public health impact and necessitates their evaluation for complete EPI schedule at a large scale in the EPI system.     

cag A阳性幽门螺杆菌与老年胃十二指肠病的相关性

目的 探讨本地区老人幽门螺杆菌（Hp）tagA基因存在状况及其与老年胃十二指肠病的关系。方法 收集89例老年和96例青壮年慢性胃炎、消化性溃疡患菌及30例正常对照人群的血清标本及胃组织标本,应用血清学检验其Hp-cag A阳性菌株感染状况。结果 89例老年患者中慢性胃炎、胃溃疡、十二指肠溃疡的Hp-cag A基因的阳性率分别为73．5％（38／52）、81．3％（13／16）及85．7％（18／21）;96例青壮年患者中慢性胃炎、胃溃疡、十二指肠溃疡的Hp-cag A基因的阳性率分别为59．3％（32／54）、68．8％（11／16）及61．5％（16／26）;对照组Hp-cag A阳性病株感染率为33．3％,各疾病组间Hp-cag A阳件菌株感染率差异无显著性（P〉0．05）．仍均高于对照组（P〈0．05）;cag A阳性Hp菌株感染率老年组高于青壮年组（P〈0．05）。结论 本地区老年患者cag A阳性Hp菌株感染与上述3种胃十二指肠疚病的发生均密切相关．老年患者感染的Hp绝大多数为cag A阳性菌株。     

纤溶酶原激活物抑制物-1基因4G/5G基因型分布频率与心肌梗死和脑梗死相关性初步分析

目的研究我国汉族人纤溶酶原激活物抑制物-1基因启动子区-675位4G/5G(单鸟嘌呤核苷酸插入/缺失)基因多态性与心肌梗死和脑梗死的等位基因特异性的相关性.方法以等位基因特异性聚合酶链反应(AS-PCR)扩增56例心肌梗死患者,54例脑梗死患者,83例无关健康对照个体的基因组DNA,鉴定PAl-1 4G/5G基因型及分布频率,常规方法检验研究个体的主要临床和生化指标.结果PAI-1基因启动子区4G/5G基因多态性在心肌梗死,脑梗死患者组中的分布频率与对照组明显不同.在心肌梗死组中,4G/4G基因型分布频率(71.40%)比对照组(30.12%)显著增加(P＜0.001),杂合型4G/5G基因型分布频率(25.00%)比对照组(62.65%)明显降低;而在脑梗死组中,4G/4G,4G/5G基因型分布频率(分别为20.37%,55.56%)均比对照组(分别为30.12%,62.65%)低,5G/5G基因型明显增加(24.07%vs7.32%,P＜0.001).而且心梗组中血浆PAI-1活性水平随着4G等位基因的减少而降低;脑梗死组中,血浆PAI-1活性水平随着5G等位基因的升高而增加.心肌梗死、脑梗死患者组中的血浆PAI-1活性水平,甘油三酯水平和血糖水平都比对照组明显升高(分别为P＜0.001,P＜0.05,P＜0.001).结论本研究表明,中国汉族人PAI-1基因启动子区4G/5G基因多态性可能和心肌梗死、脑梗死发生的危险性相关,4G/5G基因多态性可能是一种重要的遗传性血栓性疾病的危险因子.     

急性心肌梗死血小板及纤溶活性的改变

目的：了解急性心肌梗死（AMI）患血小板活化及纤溶状态，探讨其在发病机制中的作用及应采取的对策。方法：测定27例AMI患及正常对照组的血浆GMP－140、t-PA、PAI、DD含量。结果：AMI患血浆GMP－140、PAI的含量明显高于正常对照组（P＜0．01）。而t-PA含量则明显低于正常对照组（P＜0．01）。AMI恢复期血浆GMP－140水平低于急性期的（P＜0．05）。DD在急性期内（≤2天）无显增高。恢复期高于急性期及正常对照组（P＜0．01）。结论：急性心肌梗死患血小板活性增高而纤溶活性降低；要施行积极的抗血小板治疗和早期溶栓治疗，要重视动脉粥样硬化防治以防止血管内皮细胞损害，预防心肌梗死的发生。     

上海地区幽门螺杆菌菌株cag致病岛基因cagA、cagE、cagT检出率及临床意义

目的 检测上海地区幽门螺杆菌（Ｈｐ）分离株ｃａｇ致病岛（ＰＡＩ）中ｃａｇＡ、ｃａｇＥ、ｃａｇＴ基因,初步探讨ｃａｇＰＡＩ的完整性及其与胃十二指肠疾病的关系。方法 用多聚酶链反应（ＰＣＲ）技术扩增和检测了９９株从１７例慢性浅表性胃炎、２１例慢性性胃炎、１９例胃溃疡、２３例十二指肠溃疡和１９例胃癌中分离的Ｈｐ菌株的ｃａｇＡ、ｃａｇＥ、ｃａｇＴ基因。结果 ｃａｇＡ、ｃａｇＥ和ｃａｇＴ的总检出率分别为８４．８％（８４／９９）、９９．０％（９８／９９）和８４．８％（８４／９９）,各基因检出率在各种胃十二指肠疾病患者分离的Ｈｐ菌株之间差异无显著性（均Ｐ〉０．０５）。９８株ｃａｇＥ阳性的菌株中,有１４株ｃａｇＡ阴性。结论 上海地区分离ｐ菌株绝大多数可能具有完整的ｃａｇＰＡＩ,其完整性与其感染后的临床结局不相关。ｃａｇＥ基因可