Fibrinogen binding to human blood platelets: effect of gamma chain carboxyterminal structure and length

Recent evidence suggests that fibrinogen binding to platelets is mediated by the 12 carboxyterminal amino acid residues of the gamma chain. Because human plasma fibrinogen gamma chains differ in mol wt and carboxyterminal amino acid sequence, we examined the effect of such gamma chain heterogeneity on platelet-fibrinogen interactions, using two fibrinogens of distinct composition, separated by ion exchange chromatography. One fibrinogen possessed only gamma chains of mol wt 50,000 (F gamma 50), the predominant gamma chain species found in plasma. The other fibrinogen possessed equal amounts of gamma chains with mol wt 50,000 and 57,500 (F gamma 50,57.5), with the longer gamma chain (gamma 57.5) possessing an amino acid extension at the carboxyterminal end. The latter fibrinogen was 50% less effective than F gamma 50 in supporting ADP-induced platelet aggregation at concentrations of .01 to 2 mg/mL. Scatchard analysis revealed no difference in the binding affinities of the two fibrinogens to ADP- treated platelets, but the amount of F gamma 50,57.5 that was bound to platelets at saturation was only 50% that of F gamma 50. Fibrinogen receptors that remained unoccupied in the presence of saturating concentrations of F gamma 50,57.5, however, could be occupied by fresh F gamma 50. Excess unlabeled F gamma 50 displaced both radiolabeled fibrinogens from activated platelets, and both fibrinogens bound to the same platelet receptor, as judged by the inhibition of binding to stimulated platelets by a monoclonal antibody directed against the glycoprotein (GP) IIb/IIIa complex. Furthermore, an intact GPIIb/IIIa complex was required for these reactions, since platelets incubated with EDTA at 37 degrees C at alkaline pH failed to aggregate and bound neither fibrinogen in response to ADP following recalcification. Approximately 50% of each fibrinogen bound irreversibly to platelets after one hour and failed to dissociate in the presence of 10 mmol/L of EDTA or excess unlabeled F gamma 50. The data demonstrate that heterodimeric F gamma 50,57.5 binds less well to platelets and supports platelet aggregation only half as well as homodimeric F gamma 50. These results support prior conclusions that the carboxyterminal portion of the gamma chain is important in platelet-fibrinogen interactions, and suggest that the 20 amino acid, hydrophobic gamma chain carboxyterminal extension of F gamma 50,57.5 may sterically hinder the interaction of this fibrinogen with platelet receptors.     

Induction of human platelet fibrinogen receptors by epinephrine in the absence of released ADP

The ability of epinephrine to expose platelet fibrinogen receptors independent of released ADP was assessed using aspirin-treated, gel- filtered platelets. Similar to ADP-induced aggregation, platelet aggregation in response to epinephrine was accompanied by fibrinogen binding. Ten micromolar epinephrine induced a maximum number of platelet fibrinogen receptors in the absence of significant 14C- serotonin release. As indicated by Scatchard analysis, receptors exposed by both epinephrine and ADP had similar affinities for fibrinogen, but epinephrine induced approximately 30% fewer receptors than did ADP. This appears to correlate with the lesser degree of primary aggregation observed with this agent. Studies using phentolamine, a specific alpha-adrenergic antagonist, apyrase, or creatine phosphate/creatine kinase indicate that the exposure of platelet fibrinogen receptors by epinephrine was specific for platelet alpha-adrenergic receptor stimulation and was not the result of released ADP.     

Adjuncts to case assessment of vaginal discharge syndrome in pregnant women

ObjectiveTo investigate the aetiology of abnormal vaginal discharge, using a non-culture based method, among pregnant women presenting at the University of Calabar Teaching Hospital, Calabar, Nigeria.MethodsTwo hundred consecutive antenatal patients, aged 18 to 38 years, with complaints of abnormal vaginal discharge between 1st April and 31st July 2004 were investigated clinically for the characteristics of the vaginal discharge. High vaginal swabs taken from the vaginal fornices were examined using a non-culture based method to determine the possible aetiology of the discharge. The possibility of integrating non-culture based laboratory methods in the syndromic case management of abnormal vaginal discharge in an antenatal clinic setting is discussed.ResultsThe commonest form of abnormal discharge was curdy white in 66% of cases. Ten (5%) women had malodourous vaginal discharged, 92% had vulval itching; and superficial dyspareunia was seen in 29% of cases. Microscopic studies of vaginal discharge revealed the following findings: lactobacilli (96%), polymorphs (96%), 'clue' cells (4%); positive Whiff test (5%), and pH > 4.5 (7%). The clinical and laboratory assessment of each patient lasted between 35 and 45 minutes. The procedures used were acceptable to 78% of women.ConclusionThe use of non-culture based laboratory methods in the initial assessment of abnormal vaginal discharge can be a useful adjunct in the syndromic case management of abnormal vaginal discharge in pregnant women.     

B 超诊断前置胎盘分型的再探讨

目的 对Ｂ超诊断前置胎盘分型的改进探讨。方法 对３６例前置胎盘患者进行Ｂ超探查。观察胎盘下缘与子宫内口的关系。结果 前置胎盘的Ｂ超声像图可分四类：①胎盘中央部位于宫内口。②胎盘边缘部完全覆盖宫内口。③胎盘下缘至宫内口边缘,未覆盖宫内口。④盈盘位于子宫下截,未达到宫内口。结论 部分性前置胎盘的超声诊断分型担法不确切可予取消。将中央性前置胎盘诊断分两个亚型：中央型、边缘型。     

氨溴特罗口服液治疗支气管炎患儿的效果

目的：观察氨溴特罗口服液治疗支气管炎患儿的效果。方法选取承德市中医院2013年7月~2014年7月收治的支气管炎患儿100例,将其随机分为A、B两组。两组患儿均在常规治疗基础上分别给予氨溴特罗口服液及盐酸氨溴索糖浆进行治疗。比较两组患儿不同药物治疗后症状控制情况及治疗总有效率等指标。结果 A组患儿咳嗽、咳痰、喘息、肺部啰音、憋闷缓解时间及住院时间分别为(7.4±1.2)、(6.1±1.1)、(6.0±1.2)、(4.7±1.5)、(3.7±1.1)、(9.1±1.4)d,均显著短于B组[(10.3±2.1)、(8.4±1.2)、(7.5±1.4)、(5.2±1.3)、(4.3±1.4)、(13.7±1.5)d],差异有统计学意义(P约0.05)。A组患儿治疗后显效29例(58.0%),有效21例(42.0%),总有效率(100.0%)显著优于B组患儿[显效17例(34.0%),有效20例(40.0%),总有效率(74.0%)],两组总有效率比较,差异有统计学意义(P约0.05)。治疗后A组患儿咳嗽症状、咳痰量、痰液黏稠程度评分均较治疗前及B组患儿明显改善,差异有统计学意义(P约0.05)。结论临床应用氨溴特罗口服液可在短时间内缓解患儿咳嗽、发热等不适症状并缓解支气管痉挛。服药后起效速度快,且药效发挥时间长,有助于痰液排出并有效抑制炎性物质释放。服药后患儿不良反应较少,治疗安全性高,对加快疾病治疗速度、改善患儿预后情况并提高其生活质量具有重要意义。     

Sinusoidal caliber in alcoholic and nonalcoholic liver disease: diagnostic and pathogenic implications

Portal hypertension in alcoholic liver disease has been attributed to an increased resistance to blood flow either of sinusoidal or of postsinusoidal origin. The former should be accompanied by sinusoidal compression while the latter is expected to result in an increased or a normal sinusoidal diameter. Patients with alcoholic liver disease showed a marked reduction (p less than 0.001) in relative sinusoidal area (995 +/- 135 micron 2; n = 19) when compared to nonalcoholic patients with normal liver histology (5,100 +/- 389 micron 2; n = 6), or to patients with nonalcoholic liver disease (6,242 +/- 467 micron 2; n = 19). Hepatocyte surface area was significantly increased in patients with alcoholic liver disease when compared to hepatocytes from normal biopsies (563 +/- 32 micron 2 vs. 301 +/- 26 micron 2; p less than 0.001). Patients with nonalcoholic liver disease had hepatocyte surface areas within the normal range (327 +/- 14 micron 2). There was a significant inverse correlation between hepatocyte size and sinusoidal area (r = -0.63; p less than 10(-6); n = 44), indicating that larger hepatocytes were associated with sinusoidal compression. In the alcoholic patients, portal pressure correlated inversely (r = -0.77; p less than 0.01) with sinusoidal area only after the sinusoidal area was markedly reduced to areas below 20% of normal. Such a threshold was not reached in patients with nonalcoholic liver disease, in whom no correlation between sinusoidal area and portal pressure was observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human chorionic gonadotrophin and steroid concentrations in follicular fluid: the relationship to oocyte maturity and fertilization rates in stimulated and natural in-vitro fertilization cycles

The study investigates the relationship of follicular fluidsteroids and human chorionic gonadotrophin to oocyte maturityand fertilization rates in stimulated and natural cycles. Oestradiol,progesterone, testosterone and human chorionic gonadotrophinwere quantified in 129 samples of follicular fluid and the progesterone:oestradiol ratio calculated. Both stimulated cycles (short andlong luteinizing hormone-releasing hormone/human menopausalgonadotrophin regimens) and natural cycles were compared. Atotal of 60 women were studied, 20 in each group. In the naturalcycles, testosterone was significantly lower in follicles withintermediate oocytes (P = 0.015). Both oestradiol and testosteronewere significantly lower in stimulated cycles compared to naturalcycles (P = 0.032 and P = 0.034 respectively). In the ovarianstimulation cycles, the progesterone: oestradiol ratio was significantlyhigher when oocytes fertilized (P = 0.052). Moreover, in thestimulated cycles, oestradiol and human chorionic gonadotrophinwere significantly lower in the short protocol compared to thelong protocol. The data demonstrate that the hormonal milieuof the follicle is altered in downregulated stimulated cyclesto varying degrees, depending partially on the type of protocolused. Furthermore, the progesterone: oestradiol ratio, ratherthan individual hormone concentrations, may be a useful predictorof the fertilizing capacity of the oocytes.     

脑电图在大脑半球切除术前后表现及临床意义

目的:探讨半球综合征(Hemispheric syndromes,HS)患者病变半球切除术前后发作间期与发作期的脑电图(EEG)表现特点及其临床意义。方法:总结自2001年4月至2004年4月行大脑半球切除手术的4例患者的临床资料并结合脑磁共振成像(MRI),对其发作间期、发作期以及病损大脑半球切除术半年后复查EEG结果进行分析总结。结果:4例患者MRI均显示为一侧半球广泛病变,对侧正常。EEG均表现为两侧不对称,患侧波幅明显减低。其中3例EEG表现出背景抑制。发作间期癫 癎异常波表现:1例癎样放电出现的侧别与影像学检查结果相反,2例患者出现了双侧同步癎样放电,1 例无明显异常波。发作期EEG表现:1例患者癎样放电起源与病灶侧别相符,其余3例出现在病灶的对侧。所有患者均接受了病灶侧大脑半球切除术,术后随访最短1例为12个月,4例均没有癫癎发作。手术半年后复查EEG,2例患者对侧发作间期癎样放电未消失,2例对侧EEG正常。结论:EEG对HS患者手术前定位诊断及预后判断都有一定的价值。分析HS头皮EEG时,要考虑到两侧大脑结构的绝对不对称性;当出现双侧癫癎异常放电时,不排除手术可以获得良好预后的可能性,可考虑对患侧半球行切除术治疗。EEG发作期单侧起源,在HS患者癫癎灶定位方面,与MRI结果相比,价值有限。HS患者,如明确患侧已不存在重要功能,应尽早手术治疗。     

Extraadrenal pheochromocytoma: detection during pregnancy using MR imaging

This case report demonstrates the usefulness of magnetic resonance (MR) imaging to demonstrate an abdominal mass during pregnancy. A pregnant woman presented in midgestation with symptoms and chemical evidence of a pheochromocytoma. The use of MR imaging permitted early localization of a retrouterine tumor when it would have been undesirable for the woman to undergo computed tomography because of radiation exposure. Evaluation of the MR images formed the basis of the therapeutic strategy used by the patient's physicians.