High shear stress attenuates agonist-induced, glycoprotein IIb/IIIa-mediated platelet aggregation when von Willebrand factor binding to glycoprotein Ib/IX is blocked

High shear stress facilitates von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib/IX, causing activation of GPIIb/IIIa to induce platelet aggregation. Here we report that activated GPIIb/IIIa, even occupied by ligands, is not sufficient to mediate platelet aggregation under high shear stress conditions when vWF binding to GPIb/IX is blocked. Platelet rich plasma or washed platelet suspension supplemented with purified human fibrinogen at a concentration of 2 mg/mL were treated with an anti-vWF monoclonal antibody NMC-4 which blocks the binding of vWF to GPIb/IX. After addition of 10 mumol/L ADP, aggregation was continuously monitored under various shear stress conditions (0-108 dyne/cm2) using a cone-plate type aggregometer previously described (Ikeda Y et al J Clin Invest 1991; 87:1234). The extent of maximal aggregation of agonist-stimulated platelets in the presence of NMC-4 correlated inversely with the level of shear stress applied, with the virtual absence of aggregation at 108 dyne/cm2. Once aggregated by 10 mumol/L ADP under low shear stress (12 dyne/cm2), platelets could be disaggregated, in part, by the application of high shear stress (108 dyne/cm2), and reaggregated when shear stress was returned to 12 dyne/cm2. Flow cytometric analysis revealed that platelets stimulated with 10 mumol/L ADP at 108 dyne/cm2 bound fluorescein isothiocyanate (FITC)-labeled fibrinogen, although aggregation was absent in this experimental condition. These results demonstrate the dual effect of shear stress on platelet functions; a pro-aggregating activity that induces vWF-GPIb/IX interaction leading to platelet activation, and an anti-aggregating force to prevent the growth of platelet thrombi. It is suggested that the efficacy of vWF blockade is greater under high shear than low shear stress conditions, and that a selective inhibition of platelet functions can be possible.

Involvement of reactive oxygen species in the induction of chemokine JE/MCP-1 gene by phorbol-12-myristate-13-acetate in Balb 3T3 cells

The induction of JE/MCP-1 gene by TPA was transcriptionally suppressed by antioxidants such as pyrrolidine dithiocarbamate (PDTC) or trimethylthiourea (TMTU) in Balb 3T3 cells, whereas that of other early response genes, c-fos or egr-1, was not affected by these agents. Induction of the JE gene by TNF alpha or serum was not completely inhibited by these antioxidants inhibited an increase in intracellular oxidized state of cells treated with TPA. Next we examined the transcriptional regulatory region of the rat JE gene to determine the genomic target of active oxygen species. The chloramphenicol acetyltransferase (CAT) reporter gene, containing the 5'-upstream region approximately 2.6 kb DNA from the cap site, was transfected into Balb 3T3 cells. The CAT activity induced by TPA increased in parallel with the endogenous JE and mRNA level, and the increase was inhibited by the antioxidants. The essential region for this response in the upstream region was within the -2.6 to -2.0 kb region, and further defined to -2,224 to -2,069 bp which contained and NF kappa B-binding element. Gel shift analysis indicated that the nuclear factors that bound to this essential element contained NF kappa B, and that NF kappa B activity was stimulated by TPA and inhibited by PDTC. These results suggest that active oxygen species are involved in induction of the JE gene caused by TPA in Balb 3T3 cells, through NF kappa B activation.

Long-term follow-up of hemostatic molecular markers during remission induction therapy with all-trans retinoic acid for acute promyelocytic leukemia. Keio Hematology-Oncology Cooperative Study Group (KHOCS)

Hemostatic molecular markers were serially monitored in a prospective fashion during remission induction therapy with all-trans retinoic acid (ATRA) in sixteen patients with acute promyelocytic leukemia (APL). One patient with leukocytosis before treatment and three patients who later developed hyperleukocytosis also received chemotherapy with behenoyl Ara-C and daunorubicin. Plasma levels of E-fragment of fibrin and fibrinogen degradation product (FDP-E), FDP-D dimer (D-D), thrombin-antithrombin complex (TAT), and plasmin-alpha 2 plasmin inhibitor complex (PIC) were markedly elevated in all but one patient before treatment, and these parameters decreased to normal or near normal ranges in most patients within the first 7 days of treatment. Interestingly, we have found that these parameters were again elevated during the later course of ATRA therapy (after day +7) in eleven patients for various reasons including cytotoxic chemotherapy (3 cases), fever (5 cases; 2 cases with apparent infection, 3 cases without known etiology), Caesarean section (1 case), and no apparent etiology (2 cases). Three patients showed bleeding complications during re-elevation of molecular markers, but none developed thrombosis. Plasma elastase-alpha 1 proteinase inhibitor complex (E-alpha 1 PI) was markedly elevated in all patients at diagnosis and did not decrease significantly during ATRA therapy. Plasma tissue factor antigen was mildly elevated in one out of four patients studied, and thrombomodulin was elevated in two out of ten patients tested. These results confirmed the rapid normalization of coagulopathy during the early phase of remission induction therapy with ATRA but suggest that re-elevation of molecular markers occurs frequently during the later course of ATRA therapy.

Cloning and molecular analysis of the Arabidopsis gene Terminal Flower 1

The Arabidopsis gene Terminal Flower 1 (TFL1) controls inflorescence meristem identity. A terminal flower (tfl1) mutant, which develops a terminal flower at the apex of the inflorescence, was induced by transformation with T-DNA. Using a plant DNA fragment flanking the integrated T-DNA as a probe, a clone was selected from a wild-type genomic library. Comparative sequence analysis of this clone with an EST clone (129D7T7) suggested the existence of a gene encoding a protein similar to that encoded by the cen gene which controls inflorescence meristem identity in Antirrhinum. Nucleotide sequences of the region homologous to this putative TFL1 gene were compared between five chemically induced tfl1 mutants and their parental wild-type ecotypes. Every mutant was found to have a nucleotide substitution which could be responsible for the tfl1 phenotype. This result confirmed that the cloned gene is TFL1 itself. In our tfl1 mutant, no nucleotide substitution was found in the transcribed region of the gene, and the T-DNA-insertion site was located at 458 bp downstream of the putative polyadenylation signal, suggesting that an element important for expression of the TFL1 gene exists in this area.

Cervical aortic arch associated with 22q11.2 deletion

A 16-year-old boy had cervical aortic arch associated with 22q11.2 deletion. This case is the first one reported of cervical aortic arch in which deletion within the 22q11.2 band was detected by the fluorescent in situ hybridization (FISH) method.

bmr3, a third multidrug transporter gene of Bacillus subtilis

A third multidrug transporter gene named bmr3 was cloned from Bacillus subtilis. Although Bmr3 shows relatively low homology to Bmr and Blt, the substrate specificities of these three transporters overlap. Northern hybridization analysis showed that expression of the bmr3 gene was dependent on the growth phase.

Role of increased production of monocytes TNF-alpha, IL-1beta and IL-6 in psoriasis: relation to focal infection, disease activity and responses to treatments

To evaluate the immunological function of peripheral blood monocytes (PBMC) in psoriasis, we measured spontaneous production of the inflammatory cytokines, TNF-alpha, IL-1beta and IL-6 from the PBMC of psoriasis patients, by enzyme linked immunosorbent assay (ELISA). The production of all three inflammatory cytokines by psoriatic PBMC was significantly higher than that by normal control PBMC. PBMC sampled from active psoriasis produced three cytokines significantly higher than samples from inactive psoriasis. In addition, IL-1beta and TNF-alpha production showed a positive relation to clinical severity, but IL-6 did not. TNF-alpha production increased much more than did the others. Therefore, the TNF-alpha to IL-1beta ratio was significantly higher, even in inactive psoriasis, than that of the normal control. In relation to focal infection, psoriatic PBMC sampled 3 h after a tonsillar provocation test increased cytokine production, compared with the level before provocation. The cases which responded to tonsillectomy or systemic methotrexate therapy, but not the non-responding cases, showed a significant decrease in PBMC cytokine productivity. These results strongly suggest that inflammatory cytokines, especially TNF-alpha, from monocytes are involved in the pathogenesis of psoriasis, and activated monocytes may work as an effective mediator of focal infection in skin lesions.

Synergistic cytotoxic effect of quercetin and heat treatment in a lymphoid cell line (OZ) with low HSP70 expression

Heat shock protein 70 (HSP70) protects cells from various injurious stimuli and is important in cell growth and differentiation. However, its expression in leukemia cells has not been analyzed systematically. We, therefore, investigated the expression of HSP70 in various types of leukemia cells and hematopoietic cell lines. Immunoblot analysis revealed that HSP72/73 were expressed at low levels in the acute lymphocytic leukemia cells and lymphoid cell lines examined. However, heat (43 C for 2 h) preferentially augmented HSP72/73 expression in lymphoid cells. This induction was partially blocked by the treatment with quercetin (10 microM for 24 h). Finally, heat shock following quercetin treatment synergistically induced apoptosis in a lymphoid cell line (OZ). These observations suggest the possibility of selective purging of lymphocytic leukemia cells by combination with quercetin and heat.

Thyroid hormone stimulates Na(+)-Ca2+ exchanger expression in rat cardiac myocytes

We investigated whether thyroid hormone directly affects Na(+)-Ca2+ exchanger expression in cardiac myocytes. Cultured neonatal rat cardiocytes were prepared from 1-day-old Sprague-Dawley rats. Intracellular Na+ concentration ([Na+]i) in cardiocytes was measured by using the Na(+)-sensitive dye sodium-binding benzofran isophthalate (SBFI). Na(+)-Ca2+ exchanger messenger RNA (mRNA) and protein expression were assayed by Northern and Western blotting, respectively. Triiodothyronine (T3; 10(-8) M) showed no effect on [Na+]i in cardiocytes, whereas ouabain (100 microM) caused a significant increase in [Na+]i from 11.3 +/- 5.0 to 21.8 +/- 5.0 mM. Exposure of cardiocytes to ouabain caused a rapid increase in Na(+)-Ca2+ exchanger mRNA accumulation, with a maximal twofold elevation at 12 h. The ouabain-induced Na(+)-Ca2+ exchanger mRNA accumulation was still observed in the Ca(2+)-free culture medium. On the other hand, exposure of cardiocytes to T3 induced a gradual increase in Na+ exchanger mRNA accumulation, with a maximal threefold increase at 24 h. Even in Na(+)-free medium, T3 still induced a twofold increase in Na(+)-Ca2+ exchanger mRNA accumulation in cardiocytes. Exposure of cardiocytes to T3 for 24-48 h also caused a marked increase in Na(+)-Ca2+ exchanger protein accumulation. In conclusion, thyroid hormone directly increases cardiac Na(+)-Ca2+ exchanger expression, independent of alterations in Na+ mobilization. These findings suggest also that thyroid hormone and Na+ regulate Na(+)-Ca2+ exchanger gene expression through distinct molecular regulatory pathways.

Quantitative evaluation of inflammatory cells in seasonal allergic conjunctivitis

This study aimed to investigate the inflammatory changes occurring in the allergic conjunctiva due to different allergens. Ninety-two allergic conjunctivitis patients were divided into two groups: group I showed cedar pollen sensitivity only; group II showed sensitivities to cedar pollen and household dust or mites. Using brush cytology procedures, quantitative evaluation of inflammatory cells in the conjunctiva was made. The mean proportion of the neutrophils and lymphocytes in group II was significantly higher than the percentage of neutrophils in group I. The counts of eosinophils showed no significant difference between groups I and II. Our results suggest that the eosinophil numbers are not different between the allergic conjunctivitis groups. The neutrophilic and lymphocytic increase in allergic conjunctivitis may be due to two distinct groups of antigens.

Reciprocal responses to dietary diacylglycerol of hepatic enzymes of fatty acid synthesis and oxidation in the rat

The activities of hepatic enzymes of fatty acid synthesis and oxidation were compared in rats fed on diacylglycerol and triacylglycerol. In the first trial, rats were fed on diacylglycerol or triacylglycerol (rapeseed oil) for 14 d. The diacylglycerol preparation contained 65.2 g and 32.6 g fatty acids/100 g total fatty acids as 1,3-species and 1,2-species respectively. Fatty acid compositions of these dietary lipids were similar. Dietary acylglycerols were added to experimental diets to provide the same amounts of fatty acids (93.9 g/kg diet). Dietary diacylglycerol compared with triacylglycerol significantly reduced the concentrations of serum and liver triacylglycerol. The activities of enzymes of fatty acid synthesis (fatty acid synthetase, glucose 6-phosphate dehydrogenase (EC 1.1.1.49) and malic enzyme (EC 1.1.1.40)) were significantly lower in rats fed on diacylglycerol than in those fed on triacylglycerol. In contrast, the rates of mitochondrial and peroxisomal oxidation of palmitoyl-CoA in liver homogenates were higher in rats fed on diacylglycerol than in those fed on triacylglycerol. In the second trial, varying amounts of dietary triacylglycerol were replaced by diacylglycerol while the dietary fatty acid content was maintained (93.9 g/kg diet). After 21 d of the feeding period the significant reductions in serum and liver triacylglycerol levels were confirmed in groups of rats fed on the diets in which diacylglycerol supplied more than 65.8 g fatty acids/kg diet (65.8 and 93.9 g/kg). Reductions in the activities of enzymes of fatty acid synthesis and increases in palmitoyl-CoA oxidation rates by both mitochondrial and peroxisomal pathways were also apparent when diacylglycerol replaced triacylglycerol in diets to supply more than 65.8 g fatty acid/kg. Increasing dietary levels of diacylglycerol also progressively increased the activities of enzymes involved in the beta-oxidation pathway (carnitine palmitoyltransferase (EC 2.3.1.21), acyl-CoA dehydrogenase (EC 1.3.99.3), acyl-CoA oxidase (EC 1.3.3.6), enoyl-CoA hydratase (EC 4.2.1.17), 3-hydroxyacyl-CoA dehydrogenase (EC 1.1.1.35), 2,4-dienoyl-CoA reductase (EC 1.3.1.34) and delta 3, delta 2-enoyl-CoA isomerase (EC 5.3.3.8)) in the liver. These results suggest that alteration of fatty acid metabolism in the liver is a factor responsible for the serum triacylglycerol-lowering effect of dietary diacylglycerol.

[Clinical classifications of Parkinson's disease]

Although typical clinical features of Parkinson's disease are widely accepted, the symptoms of individual parkinsonian patient are variable. We reviewed here the possible classification of the disease in terms 1) degree of response to levodopa, 2) rates of progression, 3) age of onset, and 4) main symptoms. In order to select a most appropriate therapeutic drug, we proposed other points for classification, 5) development of wearing-off, 6) with or without severe dementia and 7) characteristic clinical features, i.e. akinetic form, frozen form and so on. For the evaluation of long-term effects of anti-parkinsonian drugs, it is important to classify the patients by the course of alteration of cardinal or characteristic symptoms.

Angiotensinogen mRNA is synthesized locally in rat ocular tissues

Angiotensinogen (ANG) is present in the eye. However, the source has not been determined. We showed that ANG mRNA was present in several ocular tissues using RT-PCR with ANG-specific primers. One of 10 iris samples (10%), 1 of 10 ciliary body samples (10%), 3 of 10 choroid samples (30%) and 9 of 10 retina samples (90%) were positive for ANG. Our study provides the first direct evidence that the renin-angiotensin system (RAS) component ANG is synthesized locally in the eye, especially the retina and choroid portion. These are strategic locations for an ocular RAS to influence chorioretinal blood flow, raising the possibility that RAS alterations may be involved in chorioretinal vascular disease.

A novel regulatory epitope defined by a murine monoclonal antibody to the platelet GPIIb-IIIa complex (alpha IIb beta 3 integrin)

We characterized a murine monoclonal antibody, PT25-2 (IgG1), raised against washed human platelets. The antibody and its Fab fragments were both capable of inducing platelet aggregation in a fibrinogen-dependent manner and induced 125I-fibrinogen binding to unstimulated platelets (120,000 molecules/platelet at a 100 nM IgG concentration). The antibody immunoprecipitated the alpha IIb beta 3 complex from lysates of iodinated platelets but did not react with the respective subunits when complex formation was disrupted by treatment with 5 mM EDTA at 37 degrees C for 30 min. However, simply removing the extracellular divalent cation with EDTA had no effect on antibody binding indicating that the antibody's epitope depends upon a conformational structure maintained by alpha beta subunit association. Antibody binding to unstimulated, washed platelets yielded binding parameters (Kd = 40 nM, Bmax = 100,000 molecules/platelet), which were found to be virtually unchanged when binding was performed using thrombin or RGDS-peptide-stimulated platelets. Thus, the PT25-2 antibody defines a novel regulatory epitope expressed by the alpha IIb beta 3 integrin on unstimulated, quiescent platelets.

Decreased very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acid expression in placentas from preeclamptic pregnancies

OBJECTIVE

Our purpose was to investigate the levels of very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acid expression in placentas obtained from normal pregnant women at various gestational stages and from patients with preeclampsia.

STUDY DESIGN

The relative level of expression of very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acid in each sample was determined by Northern blot analysis as a ratio of the intensity to that of glyceraldehyde-3-phosphate dehydrogenase messenger ribonucleic acid.

RESULTS

The expression of very-low-density lipoprotein receptor messenger ribonucleic acid increased significantly (p < 0.05) from both the first (n = 9) and second (n = 8) trimesters to the third (n = 11) trimester. Similarly, the expression of low-density lipoprotein receptor messenger ribonucleic acid increased significantly (p < 0.05) from the first to the third trimester. The expression of both very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acids in third-trimester placentas from preeclamptic pregnancies (n = 13) was significantly lower than that in normal pregnancies in the third trimester.

CONCLUSION

These results demonstrate the expression of very-low-density lipoprotein and low-density lipoprotein receptor messenger ribonucleic acids in the human placenta, both of which increase at late gestational stages, and the decreased expression in cases of preeclampsia. Abnormal fetomaternal lipid metabolism resulting from low expression of these receptors in the placenta may be involved in the pathogenesis of preeclampsia.

[Bone marrow transplantation versus maintenance chemotherapy for adult acute leukemia in first remission]

We compared the outcome of bone marrow transplantation (BMT) with that of maintenance chemotherapy for adults with acute leukemia who achieved first remission in Japanese Red Cross Nagoya First Hospital. From 1976 to 1993, 17 patients with acute myelogenous leukemia (AML) and 10 patients with acute lymphoblastic leukemia (ALL) received allogeneic BMT from HLA genotypically identical siblings in first remission, 4 patients with ALL undertook purged autologous BMT using monoclonal antibody and complement, and 55 patients with AML and 27 patients with ALL were treated with maintenance chemotherapy. The estimated 6-year disease free survival (DFS) of AML patients was significantly higher in the BMT group than in the chemotherapy group (77.3% vs 42.6%; p < 0.01). For ALL patients, the estimated 6-year DFS was 72.5% in the allo-BMT group and 100% for the auto-BMT group, but no patient was disease free more than 2 years in the chemotherapy group (p < 0.0001). We conclude that BMT after several courses of consolidation chemotherapy is the optimal treatment of choice in patients with AML and ALL in first remission. A prospective study is needed to confirm the efficacy of BMT after intensive consolidation chemotherapy.

Low prevalence of activated protein C resistance and coagulation factor V Arg506 to Gln mutation among Japanese patients with various forms of thrombosis, and normal individuals

Resistance to activated protein C (APC), recently reported to be the most prevalent inherited cause of thrombosis among Caucasians, is associated with a single point mutation in the coagulation factor V gene. We investigated the prevalence of APC resistance and the factor V gene mutation (R506Q) in 34 consecutive Japanese patients with venous thrombosis or pulmonary thromboembolism and 63 control subjects. Three of the 33 patients examined (9%) had an APC ratio below the 5th percentile of control values (2.27), but all were above 2.0. The factor V mutation (R506Q) was not detected in the 29 patients studied, including the 3 patients whose APC ratios were below 2.27, or in 53 controls. In a tissue factor-based factor V assay to detect APC resistance recently described by Le et al. (Blood 1995;85:1704-1711), all patients studied were found to be normal including the three with a low APC ratio. We conclude that APC resistance and factor V gene mutation are less prevalent in Japan than in several European countries.

Isolation and characterization of cDNA clones corresponding to the genes expressed preferentially in floral organs of Arabidopsis thaliana

Seventeen cDNA clones of genes corresponding to mRNAs expressed preferentially in floral organs of Arabidopsis thaliana were obtained by differential screening of a flower bud cDNA library, and classified into five groups (1A, 17A, 1B, 4B and 5B) by cross-hybridization and restriction analysis. Sequence analysis revealed that the 1A-1 and 17A-1 clones encode vegetative storage proteins (VSPs). The VSP mRNAs were detected in a small amount in leaves and increased to a limited level by wounding. Both 1B-1 and 5B-1 clones were homologous to transmembrane protein cDNAs. The protein encoded by 4B-1 clone contained a proline-rich region, but no homologous proteins were found in databases.

Standard RUS skeletal maturation of Tokyo children

A total of 704 girls and 753 boys, all healthy, from 3 to 18 years of age, from Tokyo and its suburbs, were radiographed on the left hand and wrist in 1986. Their RUS (TW2) skeletal maturity was estimated, the 50th-centile skeletal maturity scores were obtained, and the smoothed RUS maturity curves were determined applying the cubic spline function to the 50th-centile scores. On this maturity curve the score at each 0.1 year of chronological age was obtained and allocated as a given RUS skeletal age. This set of scores and ages we termed the TW2-J RUS, i.e. the Japanese TW2 RUS maturity standard. Comparing this RUS standard with the British standard, the Belgian, the southern Chinese, and the northern Indian, it became clear that Japanese children's RUS skeletal maturity progresses rapidly during puberty (after ages 9 in girls and 11 in boys), and that the maximum score difference between neighbouring age groups was observed at ages 12.5 in girls and 14.5 in boys on the spline-smoothed curve. Japanese children attain the adult stage 1 or 2 years earlier than other groups of children (at ages 15 in girls and 16 in boys).

[Comparative study of bone marrow transplantation from unrelated donors and identical sibling donors in a single institute]

This retrospective study analyzes the result of bone marrow transplantation in 28 patients with unrelated donors compared with 75 patients transplanted from identical HLA sibling donors at a single institute during the same time period. One unrelated donor patient with severe aplastic anemia died without evidence of engraftment. The incidence of grade III-IV acute graft-versus-host disease (GVHD) in unrelated donor patients (19%) was higher than sibling donors (0%) and the probability of survival more than 30 years was lower compared with sibling donors. However, the probability of survival without grade III-IV acute GVHD was similar in the two groups, 62% (n = 21) vs. 65% (n = 75), and there was no significant difference in relapse-free survival, good prognostic factors; 76% (n = 11) vs. 66% (n = 37), higher risk factors; 30% (n = 11) vs. 31% (n = 21). Death due to viral infection were significantly higher among unrelated donor patients. We conclude that bone marrow transplantation for patients younger than 30 years old from unrelated donors should be considered equally to sibling donors with great care to engraftment for severe aplastic anemia, grade III-IV acute GVHD and viral infection.