Intermittent subclavian artery occlusion following clavicular fracture

Although fractures of the clavicle are common, complications are rare. A 41 year old painter developed two uncommon complications of clavicular fracture, mechanical intermittent subclavian artery occlusion and subclavian vein thrombosis. Both conditions were clearly identified on the clinical symptoms and signs and confirmed with dynamic angiography and computerised tomography. Operative intervention led to complete resolution of symptoms.     

胚胎嗅鞘细胞移植治疗脑性瘫痪：4例术后4周结果报告

目的:观察胚胎嗅鞘细胞移植治疗脑性瘫痪的有效性和安全性。方法:①病例资料:4例因出生时缺血缺氧确诊为脑性瘫痪的患者,男2例,女2例,年龄分别为14岁、岁、个月、岁。嗅92817鞘细胞由北京市虹天济神经科学研究院细胞中心提供,实验经医学伦理委员会批准,4例脑性瘫痪患者均签署知情同意书。②实验方法:根据术前MRI或CT片,患者均在局麻下行微创立体定向嗅鞘细胞移植术,选取双额放射冠为注射靶点,每侧注射1.0×106个细胞。术后给予止血、抗感染、康复等常规处理。③实验评估:分别于嗅鞘细胞移植前、移植后4周采用脑瘫综合功能评定量表、脑瘫日常生活能力量表评价患者神经功能及生活质量的改善。结果:①嗅鞘细胞移植术后4周,4例患者较术前均有不同程度的神经功能改善,未出现手术并发症。②脑瘫综合功能评定总分:病例1由92.5分增至94分,病例2由55分增至56分,病例3由10.5分增至11.5分,病例4由9.5分增至13分。③脑性瘫痪日常生活能力量表总分:病例1由82.0分增至83.5分,病例2无变化,为16.5分,病例3由5.0分增至7.5分,病例4由5.0分增至8分。结论:嗅鞘细胞移植治疗脑性瘫痪患者近期评价安全可行,可部分改善神经功能与生活质量,长期效果有待进一步随访。     

Key lectures

International Journal of Clinical Pharmacy -     

Factor V is activated and cleaved by platelet calpain: comparison with thrombin proteolysis

Platelets are known to process human factor V during secretion and/or membrane binding. We studied the functional and structural changes produced in human factor V by purified human platelet calpain (calcium- activated thiol protease) and compared the alterations with those induced by thrombin. A maximum increase in coagulant activity of 2.5- fold was observed when factor V (1 U/mL, 33 nmol/L) was incubated with calpain (0.03 U/mL, 2.7 nmol/L) in comparison with a 8.8-fold increment for alpha-thrombin (0.7 U/mL, 8 nmol/L) at 25 degrees C. Thrombin additions to reactions initiated by calpain resulted in further activation comparable to that of thrombin alone, whereas the subsequent addition of calpain had no effect on the extent or pattern of the activation of factor V by thrombin. The cleavage pattern of factor V produced by these two enzymes are distinctly different. Although thrombin activation eventually results in four final components designated C1 (150 kd), D (105 kd), E (71 kd), and F1F2 (71 to 74 kd), calpain yields initial components of 200 kd and 160 kd within one minute. Further digestion of the 200 kd species by calpain gives rise first to a polypeptide of 160 kd that is converted to a 140 kd and a 120 kd species by two minutes with an increase in coagulant activity. Immunoblotting of these fragments with the monoclonal antibody (MoAb) B10 directed to factor V and the thrombin-generated C1 fragment yields results demonstrating a common epitope in these calpain-generated components of 200, 160, 140 and 120 kd. The degradation of the initial 160 kd polypeptide gives rise to polypeptides of 100 and 65 kd, both undetectable on immunoblotting with MoAb B10. The 130, 87, 58, and 48 kd components are of less certain origin. Thus, platelet calpain generates a complex but reproducible cleavage pattern different from thrombin that may explain the partial activation observed. Nevertheless, calpain processing may play a role in early hemostatic reactions involving platelets before the appearance of the first thrombin molecule.     

Analysis of two new leukemia-associated antigens detected on human T- cell acute lymphoblastic leukemia using monoclonal antibodies

Two monoclonal antibodies (anti-3-3 and anti-3-40) were produced, which identify two new leukemia-associated antigens. Both antibodies reacted with most cell lines derived from patients with T lymphoblastic leukemia (T-ALL), but were not detected on suspensions of normal hematopoietic cells (including thymocytes) by cytotoxicity, absorption, or indirect immunofluorescence assays. Analysis of fresh leukemic cells indicated that anti-3-3 only reacted with T-ALL cells, while anti-3-40 also reacted with some non-T, non-B ALL cells and a few acute myelocytic leukemia (AML) cells. The 3-40 antigen was also found histopathologically in frozen sections of several normal tissues, including the epithelial cells and a few lymphoid cells of the thymus, and some malignant tissues. The 3-3 antigen was not found in any tissue studied. A "double absorption"assay provided additional serologic evidence that the two antibodies identify different antigenic determinants. Biochemical analysis indicated that the molecules immunoprecipitated by anti-3-3 and anti-3-40 have molecular weights of 35,000-40,000 daltons. This study demonstrated that the 3-3 and 3-40 antigens are markers for human T-ALL and can be used along with the normal T-lymphocyte antigen, 3A1, to discriminate T-ALL from cutaneous T-cell lymphoma (CTCL), adult T-cell leukemia (ATL), and T-cell chronic lymphocytic leukemia (T-CLL).     

Role of arginine residues in the coagulant activity of high molecular weight kininogen

High molecular weight (HMW) kininogen, the cofactor for activation of the contact system of plasma proteolysis, transports and optimally positions prekallikrein and factor XI on a negatively charged surface, allowing those zymogens to be activated by surface-bound factor XIIa. HMW kininogen circulates in plasma as a procofactor that, after cleavage by kallikrein or factor XIIa, gains ability to bind to the surface. The mechanism responsible for this increased affinity for the surface is unknown. We hypothesized that modification of arginine residues may prevent cleavage of HMW kininogen, since the initial kallikrein-induced cleavage sites on the HMW kininogen molecule are at the NH2 terminal and the COOH terminal of the bradykinin-containing portion of the molecule, each of which contains arginine. We found that modification with butanedione of four arginine residues in the HMW kininogen molecule prevented bradykinin release, which results from cleavage of HMW kininogen. Furthermore, HMW kininogen coagulant activity was lost, in proportion to the degree of arginine modification, until 6.6 residues had been modified. Complex formation with prekallikrein, however, was found to be uneffected by the modification of modified HMW kininogen. To account for the loss of coagulant activity, we also examined the ability of modified HMWKa (active cofactor) to bind to an activating surface. The affinity of modified HMWKa for kaolin was tenfold less than the affinity of unmodified HMWKa. These data suggest that arginine residues play a critical role in the ability of HMW kininogen to function as an activation cofactor, both by preventing the cleavages that produce HMWKa as well as by decreasing the affinity of HMWKa for the surface.     

Acute leukemia associated with the t(4;11) chromosome rearrangement: ultrastructural and immunologic characteristics

The acute leukemia associated with the t(4;11) chromosome rearrangement is characterized by relatively consistent clinical features: occurrence primarily in young individuals, hyperleukocytosis, and poor response to therapy. This study describes the morphological, ultrastructural, and immunologic characteristics of the leukemic cells from ten patients with this type of leukemia. The morphological features of the leukemic blasts vary from lymphoid-appearing to monocytic. Ultrastructurally and cytochemically, some of the lymphoid-appearing blasts possess features of myeloid origin. The immunologic phenotype is characteristically E- SIg- CALLA- BA-1- BA-2+ HLA-DR+ and TdT+. These findings suggest that the t(4;11)-associated acute leukemia represents a proliferation of an early myeloid progenitor cell.     

Protein phosphorylation in neutrophils from patients with p67-phox- deficient chronic granulomatous disease

Neutrophils are known to contain a major 67-kD protein that undergoes enhanced phosphorylation and translocation to the membrane during cell stimulation. Recent studies have assumed that this 67-kD phosphoprotein is the 67-kD subunit of the phagocyte oxidase (p67-phox). We compare here the protein phosphorylation patterns in lysates of normal neutrophils and neutrophils from patients with chronic granulomatous disease (CGD) that are completely deficient in p67-phox. The phosphoproteins were labeled by incubation of the cells with radioactive inorganic phosphate (32Pi) or by the addition of [gamma- 32P]ATP to electropermeabilized neutrophils. With either method, stimulation of the normal or CGD cells always resulted in an enhanced incorporation of 32p into two proteins in the 67-kD area. The extent of phosphorylation of these two proteins was very similar in the normal and CGD cells when permeabilized neutrophils loaded with [gamma - 32P]ATP were compared. Moreover, no overall differences in the protein phosphorylation patterns were observed between the normal and CGD cells. Our data indicate that the major 67-kD phosphoproteins observed in stimulated neutrophils are clearly different from p67-phox.     

Effect of surfaces on fluid-phase prekallikrein activation

The activation of prekallikrein by factor XII fragments (XIIf), during incubation in plastic tubes was previously noted to be increased by high molecular weight (HMW) kininogen as well as other plasma proteins. In this report, we investigated the mechanism responsible for this increase. Although we confirmed that HMW kininogen, bovine serum albumin, fibrinogen, cold insoluble globulin, and mixed phospholipids apparently increased prekallikrein activation, we found that the product of prekallikrein activation (kallikrein) lost substantial activity in less than 0.5 min after exposure to a variety of fresh surfaces. This loss was partially prevented by the presence of various proteins and phospholipids. Similar protection against inactivation of XIIf, the enzyme in this reaction, was also found. In contrast, no loss of the substrate, prekallikrein, was observed during incubation. The loss of kallikrein activity was found to be proportional to the surface area of the incubation vessel as well as the concentration of kallikrein. Further loss of kallikrein activity could also be prevented by pretreating the vessel with kallikrein. We therefore conclude that various substances apparently affect prekallikrein activation in a purified system by preventing the enzyme and product in the reaction mixture from losing activity due to adsorption to a surface.     

Inhibition of factor XII in septic baboons attenuates the activation of complement and fibrinolytic systems and reduces the release of interleukin-6 and neutrophil elastase

In previous studies, we have shown that administration of monoclonal antibody (MoAb) C6B7 against human factor XII to baboons challenged with a lethal dose of Escherichia coli abrogates activation of the contact system and modulates secondary hypotension. To evaluate the contribution of activated contact proteases to the appearance of other inflammatory mediators in this experimental model of sepsis, we studied the effect of administration of MoAb C6B7 on activation of complement and fibrinolytic cascades, stimulation of neutrophil degranulation, and release of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Activation of the complement system, as reflected by circulating C3b/c and C4b/c levels, was significantly reduced in five animals that had received MoAb C6B7 before a lethal dose of E coli as compared with five control animals that had been given a lethal challenge only. Inhibition of contact activation also modulated the fibrinolytic response, since the release of tissue-type plasminogen activator (t-PA) and the appearance of plasmin-alpha2-antiplasmin (PAP) complexes into the circulation was significantly attenuated upon pretreatment with anti-factor XII MoAb. In contrast, plasma levels of plasminogen activator inhibitor (PAI) were modestly enhanced in the treatment group. Degranulation of neutrophils, as assessed by circulating elastase-alpha1-protease inhibitor complexes, and release of IL-6 but not of TNF-alpha was decreased in anti-factor XII-treated animals. Observed differences in the inflammatory response between treatment and control groups were not likely due to different challenges, since the number of E coli that had been infused, as well as circulating levels of endotoxin after the challenge, were similar for both groups. These data suggest that activation of the contact system modulates directly or indirectly various mediator systems involved in the inflammatory response during severe sepsis in nonhuman primates.