Activation of the coagulation cascade after infusion of a factor XI concentrate in congenitally deficient patients

Virally inactivated, high-purity factor XI concentrates are available for treatment of patients with factor XI deficiency. However, preliminary experience indicates that some preparations may be thrombogenic. We evaluated whether a highly purified concentrate produced signs of activation of the coagulation cascade in two patients with severe factor XI deficiency infused before and after surgery. Signs of heightened enzymatic activity of the common pathway of coagulation (elevated plasma levels of prothrombin fragment 1 + 2 and fibrinopeptide A) developed in the early post-infusion period, accompanied by more delayed signs of fibrin formation with secondary hyperfibrinolysis (elevated D-dimer and plasmin-antiplasmin complex). These changes occurred in both patients, but were more severe in the older patient with breast cancer when she underwent surgery, being accompanied by fibrinogen and platelet consumption. There were no concomitant signs of heightened activity of the factor VII-tissue factor mechanism on the factor Xase complex (plasma levels of activated factor VII and of factor IX and X activation peptides did not increase). The observed changes in biochemical markers of coagulation activation indicate that concentrate infusions increased thrombin generation and activity and that such changes were magnified by malignancy and surgery. Because some factor XI concentrates may be thrombogenic, they should be used with caution, especially in patients with other risk factors for thrombosis.     

先天性肠闭锁166例临床分析

目的分析先天性肠闭锁病例的诊断及治疗,以提高治愈率及术后生活质量。方法回顾性分析166例先天性肠闭锁的临床资料。结果治愈142例,治愈率85.5%(142/166),其中包括18例二期手术治愈者;术中10例、术后8例放弃治疗;术后死亡6例。结论早期诊断和选择合理的术式是提高肠闭锁治愈率的关键,基础支持及手术技术改进能促进病情的恢复,改善预后。     

A role for Src kinase in spontaneous epileptiform activity in the CA3 region of the hippocampus

Members of the Src family of nonreceptor protein tyrosine kinases (PTKs) have been implicated in the regulation of cellular excitability and synaptic plasticity. We have investigated the role of these PTKs in in vitro models of epileptiform activity. Spontaneous epileptiform discharges were induced in vitro in the CA3 region of rat hippocampal slices by superfusion with the potassium channel blocker 4-aminopyridine in Mg(2+)-free medium. In hippocampal slices treated in this fashion, Src kinase activity was increased and the frequency of epileptiform discharges could be greatly reduced by inhibitor of the Src family of PTKs, 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2), but not by the inactive structural analog 4-amino-7-phenylpyrazol[3,4-d]pyrimidine (PP3). 4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine also reduced epileptiform activity induced by either 4-aminopyridine or Mg(2+)-free medium alone. These observations demonstrate a role for Src family PTKs in the pathophysiology of epilepsy and suggest potential therapeutic targets for antiepileptic therapy.     

MODES OF INACTIVATION OF NEUROHYPOPHYSIAL HORMONES: SIGNIFICANCE OF PLASMA DISAPPEARANCE RATE FOR THEIR PHYSIOLOGICAL RESPONSES

Analogues of oxytocin and deaminooxytocin with 4-glutamine replaced by 4-glutamic acid methyl ester readily lose their uterotonic activity when incubated with rat serum, presumably by hydrolysis to the much less active 4-glutamic acid derivatives. On the other hand, inactivation of the deaminooxytocin analogue in the rat uterus, as demonstrated by the 'oil-bath'technique, is only slightly more rapid than that of deaminooxytocin and distinctly slower than that of oxytocin. Its in situ/in vitro ratio of uterotonic activity is less than 0.1 whereas that for deaminooxytocin is about 3 and also the persistence of the uterotonic effect in situ is slightly less than that of deaminooxytocin. The results with these 'rapidly inactivated'analogues can be used as proof of some predictions of the three-compartment model for tissue distribution of neurohypophysial hormones and its influence upon the time course of a biological response published earlier. The potential use of analogues of neurohypophysial hormones as probes for inactivation mechanisms and the results thus far obtained are discussed.     

Ethanol increases GABAergic transmission at both pre- and postsynaptic sites in rat central amygdala neurons

We examined the interaction of ethanol with the gamma-aminobutyric acid (GABA)ergic system in neurons of slices of the rat central amygdala nucleus (CeA), a brain region thought to be critical for the reinforcing effects of ethanol. Brief superfusion of 11-66 mM ethanol significantly increased GABA type A (GABA(A)) receptor-mediated inhibitory postsynaptic potentials (IPSPs) and currents (IPSCs) in most CeA neurons, with a low apparent EC(50) of 20 mM. Acute superfusion of 44 mM ethanol increased the amplitude of evoked GABA(A) IPSPs and IPSCs in 70% of CeA neurons. The ethanol enhancement of IPSPs and IPSCs occurred to a similar extent in the presence of the GABA type B (GABA(B)) receptor antagonist CGP 55845A, suggesting that this receptor is not involved in the ethanol effect on CeA neurons. Ethanol superfusion also decreased paired-pulse facilitation of evoked GABA(A) IPSPs and IPSCs and always increased the frequency and sometimes the amplitude of spontaneous miniature GABA(A) IPSCs as well as responses to local GABA application, indicating both presynaptic and postsynaptic sites of action for ethanol. Thus, the CeA is the first brain region to reveal, without conditional treatments such as GABA(B) antagonists, consistent, low-dose ethanol enhancement of GABAergic transmission at both pre- and postsynaptic sites. These findings add further support to the contention that the ethanol-GABA interaction in CeA plays an important role in the reinforcing effects of ethanol.     

Response to 2'-deoxycoformycin after failure of interferon-alpha in nonsplenectomized patients with hairy cell leukemia

Two patients with hairy cell leukemia with massive splenomegaly and severe pancytopenia were treated with recombinant alpha-A interferon (IFN-alpha-2a). There was no significant response to a trial of IFN- alpha-2a (11 and 20 weeks) with respect to blood counts or spleen size. Subsequent treatment with 2'-deoxycoformycin (dCF) for 8 consecutive weeks (4 mg/m2/wk) resulted in normalization of spleen size and a normalization of peripheral blood counts and bone marrow in one patient. The second patient demonstrated a reduction in spleen size and improved blood counts following 9 weeks of dCF therapy but eventually became refractory. This demonstrates that dCF is non-cross-resistant with interferon and confirms the efficacy of dCF in nonsplenectomized patients.     

Evaluation of drugs for elimination of leukemic cells from the bone marrow of patients with acute leukemia

Relatively nonmyelotoxic drugs and drug combinations were investigated for their ability to eliminate malignant cells from human bone marrow. In vitro 90% inhibitory concentration (IC90) doses were established on granulocyte macrophage colony-forming units (GM-CFU) in culture of bone marrow by using the GM-CFU assay for the following drugs: 4- hydroperoxycyclophosphamide (4-HC), Adriamycin, L-asparaginase, bleomycin, hydrocortisone, VP-16, spirogermanium, Taxol, and vincristine. The leukemic cell kill efficiency of these drugs at IC90 doses was compared with that of 4-HC on acute lymphoid leukemia (ALL) cell lines by using the limiting-dilution assay. Under these conditions, no single drug was superior to 4-HC. To increase the in vitro effect in leukemic cell kill, combinations of vincristine with hydrocortisone, Adriamycin, VP-16, and 4-HC were investigated. Vincristine at 1 to 5 micrograms/mL increased the marrow cytotoxicity of hydrocortisone, Adriamycin, and VP-16, but it was protective (subadditive) with 4-HC. Vincristine and 4-HC in combination was additive to supraadditive on ALL cell lines, increased the leukemic cell kill by one to two logs above 4-HC alone at IC90 doses (P less than .05), and was not affected by the addition of excess marrow cells. The recommended doses for chemopurging in clinical studies are vincristine, 1 to 5 micrograms/mL, plus 4-HC, 5 micrograms/mL.