Annexin V as a probe of aminophospholipid exposure and platelet membrane vesiculation: a flow cytometry study showing a role for free sulfhydryl groups

Annexin V, a protein with a high affinity and a strict specificity for aminophospholipids at physiologic calcium concentrations, was used to probe platelet activation and the development of procoagulant activity. Platelet secretion was studied in parallel using VH10, a murine monoclonal antibody specific for GMP-140, an alpha-granule membrane glycoprotein. Both proteins were labeled with fluorescein isothiocyanate and platelet activation was assessed by flow cytometry. Microparticles, which are shed from the platelet surface and also support procoagulant activity, were distinguished from platelets according to their associated light scattering signal. The relative ability of different inducers to trigger exposure of the procoagulant surface and microparticle formation was: ionophore A23187 > thrombin plus collagen > collagen > thrombin. The density of aminophospholipid on microparticles was higher than on remnant platelets. Platelet activation by these agonists was accompanied by GMP-140 exposure, both on platelets and microparticles. Here, thrombin was the most efficient agonist. The mechanisms responsible for the above processes were investigated using E-64-d, a specific membrane-permeable inhibitor of Ca(2+)-activated protease (calpain); tetracaine, an activator of calpain; and N-ethylmaleimide and diamide, two sulfhydryl-reactive agents. These agents were added to platelets alone or before stimulation by agonists. Calpain activity was assessed by the hydrolysis of cytoskeletal proteins as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results showed that calpain activity is not essential for aminophospholipid translocation or for secretion. In contrast, although sulfhydryl-reactive agents alone can trigger procoagulant activity, they inhibit microvesicle formation and platelet secretion induced by the above agonists, suggesting that different mechanisms account for these phenomena. The use of annexin V in flow cytometry is a rapid method to assess procoagulant activity in platelets and the loss of phospholipid asymmetry in cell membranes.     

Role of different hematologic variables in defining the risk of malignant transformation in monoclonal gammopathy

The presenting clinico-hematologic features of 386 patients with nonmyelomatous monoclonal gammopathy (MG) were correlated with the frequency of malignant transformation to evaluate the most important variables conditioning its evolution into multiple myeloma (MM) or Waldenstrom macroglobulinemia (WM). Most of the patients (335) had monoclonal gammopathy of undetermined significance (MGUS: 39 IgA, 242 IgG, 54 IgM): the remaining 51 patients (12 IgA, 39 IgG) fulfilled all of the MGUS diagnostic criteria (according to Durie) except that bone marrow plasma cell (BMPC) content was 10% to 30%, and so they were defined as having monoclonal gammopathy of borderline significance (MGBS). There were no significant differences between the MGUS and MGBS groups in terms of age, sex, or median follow-up. After a median follow- up of 70 and 53 months, respectively, 23 of 335 MGUS and 19 of 51 MGBS patients had undergone a malignant evolution. Univariate analysis of the IgA and IgG patients showed that the cumulative probability of the disease evolving into MM correlated with diagnostic definition (MGBS v MGUS), BMPC content (> or = 10% v < 5% and < or = 5% v > 5%) and reduced serum polyclonal Ig. In the IgG cases, there was also a significant correlation with detectable Bence Jones proteinuria, serum monoclonal component (MC) levels and age at diagnosis (> 70 v < = or 55 years). In the IgG cases as a whole, the same variables remained in the Cox model where the BMPC percentage was considered after natural logarithmic transformation and the monoclonal component as g/dL value. The relative risks of developing MM are the following: 2.4 for each 1 g/dL increase of IgG, serum MC, 3.5 for detectable light chain proteinuria, 4.4 for the increase of 1 unit in log. BMPC percentage, 6.1 for age > 70, 3.6 and 13.1 for a reduction in one or two polyclonal Ig. In conclusion, our study allows the identification of a particular subset of MGUS patients (MC < = or 1.5 g/dL, BMPC < 5%, no reduction in polyclonal Ig and no detectable light chain proteinuria) at very low- risk of evolution, who can be considered as having benign monoclonal gammopathies. We also describe a previously undefined group of MG patients (with monoclonal gammopathy of borderline significance) who are at high-risk of malignant evolution. These findings could have a considerable impact on the cost/benefit ratio of monitoring programs in these patients.     

Ability of Activation Recovery Intervals to Assess Action Potential Duration During Acute No-Flow Ischemia in the In Situ Porcine Heart

Activation Recovery Intervals During No-Flow Ischemia . Introduction : The ability to assess transmural changes in action potential duration during acute no-flow ischemia is essential to an understanding of the tachyarrhythmias that occur in this setting. The purpose of this study was to determine if activation recovery intervals determined from unipolar electrograms would provide this information.
Methods and Results : We recorded simultaneously transmembrane action potentials and unipolar electrograms from sites located as closely together as possible in the center and at the lateral margin of the ischemic zone during acute no-flow ischemia and correlated the changes in activation recovery intervals obtained from the unipolar electrograms to the changes in action potential duration. We found that the activation recovery intervals provided an accurate measure of the changes in action potential duration during acute no-flow ischemia provided the electrograms had a well-defined, single negative component to the QRS complex with a maximum negative dV/dt > 10 V/sec and a single positive component to the T wave having a maximum positive dV/dt > 1.6 V/sec. Electrograms meeting these criteria comprised 90% of the electrograms recorded at the margin of the ischemic zone throughout 60 minutes of no-flow ischemia. In the center of the ischemic zone, 75% of the recorded electrograms met these criteria for the first 20 minutes of no-flow ischemia. Thereafter, the percentage declined and after 40 minutes of no-flow ischemia, none of the electrograms recorded in the center of the ischemic zone met these criteria.
Conclusion : Activation recovery intervals obtained from unipolar electrograms provide an accurate assessment of changes in action potential duration throughout the ischemic zone during acute no-flow ischemia, provided the characteristics of the electrograms meet specific predetermined criteria.     

Hypodiploidy is associated with a poor prognosis in childhood acute lymphoblastic leukemia

Leukemic cells from 31 (7.6%) of 409 children with newly diagnosed acute lymphoblastic leukemia (ALL) had a hypodiploid karyotype. The patients' ages ranged from 0.8 to 17 years (median, 5 years) and their initial leukocyte counts from 1.0 to 132 X 10(9)/L (median, 12.7 X 10(9)/L). Modal chromosome numbers for the leukemic stem lines were 45 in 26 cases, 28 in two cases, and 26, 36 and 43 in one case each. Seven cases had one to three additional abnormal lines due to clonal evolution. Chromosome 20 was lost most frequently (nine cases). Structural abnormalities--including chromosomal translocations (21 cases), deletions (ten cases), duplications (two cases), or inversions (one case)--were common findings; the nonrandom translocations consisted of the t(1;19)(q23;p13.3) in two pre-B cases and tdic(9;12)(p1?1;p1?2) in three cases of common ALL. When compared with hyperdiploid cases (greater than 50 chromosomes), ALL with hypodiploidy was found to have a poorer outcome and was more likely to be associated with chromosomal translocations, higher serum lactic dehydrogenase levels, and age less than 2 or greater than or equal to 10 years. Moreover, patients with hypodiploid ALL fared as poorly as those with pseudodiploid karyotypes, even though their leukocyte counts and serum lactic dehydrogenase levels were lower and they had a comparable frequency of leukemic cell translocations. Hypodiploidy is therefore an unfavorable karyotypic feature in childhood ALL.     

Immunosuppressive therapy of Factor VIII inhibitors

Immunosuppressive therapy was used in seven hemophiliac and three nonhemophiliac patients with factor VIII inhibiors. Permanent disappearance of the inhibitor occurred in three hemophiliac and two nonhemophiliac patients following treatment with cyclophosphamide and factor VIII. Critical factors influencing the response to therapy may include both the titer and duration of the inhibitor and the degree of intervening factor VIII exposure prior to immunosuppressive therapy. Two severe hemophiliacs with low titer inhibitors that disappeared without specific therapy are also reported.     

Prognostic importance of blast cell DNA content in childhood acute lymphoblastic leukemia

Using flow cytometric techniques, we determined the pretreatment distribution of DNA content in propidium iodide-stained leukemic blasts from 205 children with "standard-risk" acute lymphoblastic leukemia (ALL). Risk assignment was based on an initial WBC count less than 100 X 10(9)/L, no thymic mass, no meningeal leukemia, and lymphoblasts lacking sheep erythrocyte receptors or surface immunoglobulin. A single aneuploid leukemic line was detected in 74 cases (36.1%): 70 hyperdiploid and four hypodiploid. For hyperdiploid cases, the DNA index (DI, or ratio of the DNA content of leukemic v normal G0/G1 cells) ranged from 1.06 to 2.0 (median, 1.20). A secondary leukemic line with hyperdiploid cellular DNA content was identified in 21 cases with diploid primary lines. Children whose primary leukemic line showed a DI greater than or equal to 1.16 (n = 57) had significantly better responses to treatment than did those with either a diploid DI (n = 130; P = .002) or values in the range of 1.01 to 1.15 (n = 14; P = .001). The relative risk of failure for hyperdiploid cases with DI greater than or equal to 1.16, corresponding to greater than or equal to 53 chromosomes, was one-third that of the other two groups. Treatment responses of patients with both diploid and hyperdiploid lines were identical to those associated with single diploid lines, but significantly worse than those associated with single hyperdiploid lines with DI greater than or equal to 1.16 (P = .016). The most favorable prognostic variables selected by a Cox proportional hazards model were: DI greater than or equal to 1.16 (P = .001), white race (P = .022), WBC less than or equal to 25 X 10(9)/L (P = .032), age between 2 and 9 years (P = .075), and hemoglobin less than 7.0 g/dL (P = .094). DNA index greater than or equal to 1.16 retained its significant prognostic impact even after adjustment for other variables (P = .001). With the combination of DI greater than or equal to 1.16 and WBC less than or equal to 25 X 10(9)/L, one can identify a group of children with ALL who have a low probability of relapse when treated with current therapy. If they remain disease-free after longer follow-up, it may be advisable to treat them with less intensive, hence less toxic, chemotherapy than patients with higher WBC counts or lower DI values.     

Comparative anti-inflammatory properties of Capsaicin and ethyl-aAcetate extract of Capsicum frutescens linn [Solanaceae] in rats

Background

The analgesic effect of capsaicin (the active ingredient in Capsicum frutescens Linn. [Solanaceae]) had been reported in several studies. Current research is being directed at producing analgesics, anti-inflammatory agents with better side effect profile.

Objectives

To investigate if either the ethyl acetate extract of Capsicum frutescens Linn. [Solanaceae] (CFE) or capsaicin (Fluka Biotechnika-CPF) (in addition to the known analgesic properties) has any anti-inflammatory effect comparable to nonsteroidal anti-inflammatory analgesics (NSAIDS).

Methods

The effects of ethyl acetate extract of Capsicum frutescens Linn. [Solanaceae] (CFE) and capsaicin (Fluka Biotechnika-CPF) was examined on rat hind paw. Inflammation was induced in the rat''s hind paw by subplantar injections of fresh egg albumin (0.5 ml/kg). Diclofenac (100 mg/kg) was used as the reference anti-inflammatory agent for comparison, while distilled water was used as the placebo. The leucocytes count, corticosterone and C - reactive protein (CRP) levels were measured as biomarkers of inflammation. Data obtained were pooled and analysed using repeated ANOVA, in a general linear model with the CPSS software.

Results

Sub-plantar injections of fresh egg albumin (0.5 ml/kg) produced profound and time-related oedema in the rat hind paw of the ‘control’ rats. Diclofenac (DIC, 100 mg/kg, i.p.) and reference capsaicin (CPF, 2.5 mg/kg, i.p.) significantly inhibited paw swelling at (p<0.05-0.001) (CI 95%) compared to distilled water-treated ‘controls’.While the corticosterone levels were all very low in 7 rats treated with capsaicin, the leucocytes count was within normal range in 9 rats. However, in 16 specimens randomly assigned for CRP levels, there were very high CRP readings, up to a magnitude of 10 times the normal range.

Conclusions

Capsaicin in both forms (CFE and CPF) produced anti-inflammatory effects that were comparable to diclofenac in the experimental rat model at p<0.05. It may be concluded that capsaicin has both analgesic and anti-inflammatory properties.     

Cytokinetically based induction chemotherapy and splenectomy for childhood acute nonlymphocytic leukemia

A four-drug regimen, based on cell kinetic principles, induced complete remissions in 68 of 95 children (72%) with acute nonlymphocytic leukemia (ANLL). Patients entered remission after 2-5 weekly cycles of vincristine-daunorubicin (day 1) followed by sequential cytosine arabinoside and 6-azauridine (days 4-7). With continuation therapy of monthly vincristine-doxorubicin-cyclophosphamide, weekly cytosine arabinoside, and daily 6-mercaptopurine, the median duration of complete remission was 10 mo and the median survival time 21 mo. Portal triaditis, evident in 11 of 23 patients with liver biopsies, was associated with long remissions. A larger spleen size (greater than 5 cm) and a higher myeloblast labeling index (greater than 10%) at diagnosis were clearly related to shorter durations of remission. Splenectomy within 1 mo of remission had no statistically significant effect on the frequency of relapse or length of remission. Patients without central nervous system (CNS) leukemia at diagnosis, all treated prophylactically with intrathecal methotrexate, had a low frequency of initial CNS relapse (3/56, 5%). The 2-yr disease-free survival rate is 29% (20 of 68 patients attaining complete remission). fifteen patients have completed 2.5 yr of therapy, and each remains in continuous complete remission, off treatment, for 1+ -36+ mo. This induction chemotherapy was as effective as more intensive regimens, with the advantage of less toxicity and shorter periods of hospitalization.     

Central nervous system leukemia in children with acute nonlymphoblastic leukemia

Factors contributing to the development of central nervous system (CNS) leukemia, and the impact of leukemic involvement of this site on subsequent remission length, were determined in 184 children with acute nonlymphoblastic leukemia who had been treated in two successive clinical trials. Preventive CNS therapy in both studies consisted of intrathecal methotrexate (12 mg/m2) given monthly during the first six months of therapy and then every three months until all treatment was stopped. Children with CNS leukemia at diagnosis or relapse were given intrathecal chemotherapy weekly for four weeks and then monthly throughout the remainder of the treatment course. Those continuing in complete remission received 2,400 rad cranial irradiation plus five doses of intrathecal methotrexate before cessation of therapy. The 38 children (20.7%) with CNS leukemia at diagnosis were more likely to have an initial leukocyte count greater than or equal to 25 X 10(9)/L (P = .01) and age less than 2 years (P = .03). The presence of CNS leukemia at diagnosis did not adversely affect the remission induction rate (P = .13) or the length of complete remissions (P = .73). CNS relapse ended initial remissions in 11 patients only and did not preclude subsequent long-term survival, as four of these children are off therapy and in second complete remission for 33+ to 78+ months. Three features at diagnosis were predictive of CNS relapse: monocytic or myelomonocytic leukemia (P = .002); age less than 2 years (P = .0001); and leukocyte count greater than or equal to 25 X 10(9)/L (P = .012). By stepwise Cox regression analysis, each factor was found to have independent predictive value. Despite the apparent effectiveness of intrathecal methotrexate as preventive CNS treatment, our findings indicate that more effective prophylaxis is needed for patients with features predisposing to CNS relapse.