A novel missense mutation in codon 218 of the albumin gene in a distinct phenotype of familial dysalbuminemic hyperthyroxinemia in a Japanese kindred

Familial dysalbuminemic hyperthyroxinemia (FDH) is the most common cause of inherited euthyroid hyperthyroxinemia in Caucasians. To our knowledge, no such documentation on Asians exists. Six of 8 members of a 3-generation Japanese family were found by us to carry the FDH phenotype. Serum total T4 levels ranged from 1763.2-2741.3 nmol/L (normal range, 65.6-164.7), serum total T3 levels ranged from 2.73-5.62 nmol/L (normal range, 1.47-2.95), and rT3 levels ranged from 1.08-2.52 nmol/L (normal range, 0.22-0.60). In the proband, the majority of [125I]T4 in serum T4-binding proteins was distributed in albumin fractions, and the isolated albumin had an increased affinity for T4. A guanine to cytosine transition in the second nucleotide of codon 218, resulting in replacement of normal arginine with proline, was detected in 1 of 2 alleles in all 5 subjects of the family with FDH. In all FDH-affected Caucasian subjects from 10 unrelated families with a moderate increase in serum T4, the guanine to adenine transition was demonstrated at the same position of the albumin gene as noted in our patients, but histidine, the replacement amino acid, differed from proline noted in our FDH Japanese subjects. It would thus appear that FDH has ethnic variations.

Characterization and sensitivity to interleukin 2 and interferon alpha of leukemic cells from a patient with large granular lymphocytic leukemia associated with chronic active Epstein-Barr virus infection

A patient presented with chronic large granular lymphocyte leukemia associated with chronic active Epstein-Barr virus infection (CAEBV). Cell cycle analysis revealed a minimal growth compatible with chronic lymphocytic leukemia After 5 months of treatment, the patient died from acute transformation of the leukemia. Cell harvested during chronic phase were analyzed for sensitivity to interleukin 2 (IL-2) and interferon alpha (IFN alpha) in vitro by means of surface phenotyping and cell cycle assay. IL-2 induced remarkable growth of the cells, whereas IFN alpha did not confer a growth advantage. Since IFN alpha was expected to have no growth induction effect on the leukemia cells, it was administered to the patient to treat the CAEBV.

Primary familial polycythaemia associated with a novel point mutation in the erythropoietin receptor

Primary familial and congenital polycythaemia (PFCP) is a rare disease characterized by congenital erythrocytosis inherited in an autosomal dominant fashion. Recently, mutations in the erythropoietin receptor (EpoR) have been identified in PFCP families. We describe a Japanese family with an autosomal dominant inheritance of PFCP. An in vitro colony assay demonstrated hypersensitivity of erythroid progenitors to erythropoietin (Epo) in affected family members. Sequence analysis of RT-PCR products amplified from the C-terminal region of EpoR transcripts in affected family members revealed that they were all heterozygous for C and T bases at position 5986, which suggested a genetic mutation (C to T) on one allele of EpoR. This mutation gave rise to a translation termination codon TAG at amino acid 435. Thus, the resulting EpoR is a truncated protein product lacking all 74 amino acids downstream of the mutation. To date, all genetic mutations affecting a family with PFCP, including this one, have been located in the cytoplasmic negative regulatory region of the EpoR. All mutations gave rise to truncated Epo receptors between Tyrosine 427 and Tyrosine 455. The phosphotyrosines in this region of EpoR have been demonstrated to be binding sites for SHP-1 phosphatase. Therefore PFCP is presumably brought about as a result of genetic mutations which cause the loss of the SHP-1 binding site in the cytoplasmic region of EpoR.

Complete remission in three patients with acute myeloblastic leukemia by administration of G-CSF without antileukemic agents

We describe 3 patients with acute myeloblastic leukemia (AML), who received rhG-CSF for infections such as pneumonia or for prophylaxis of infection, and who achieved complete remission. They had not received any antileukemic therapy before or during the administration of rhG-CSF. These findings suggest the possibility that complete remission can be brought about by G-CSF itself in some patients with AML.

[Autoantibodies and thrombosis]

During late seventies it became apparent that the appearance of antiphospholipid antibodies is associated with thromboembolic manifestations, such as cerebral or myocardial infarction, pulmonary thromboembolism, deep vein thrombosis, intrauterine fetal losses and thrombocytopenia. The term antiphospholipid syndrome has been used to define this set of pathologic features. Recognition of this syndrome has spread worldwide as its clinical implications have become appreciated. Recent studies showed that cofactor, beta 2-glycoprotein I (beta 2-GPI) is required for binding of anticardiolipin antibodies (aCL) raised in the patients with SLE and related other autoimmune disorders. However, this finding has generated considerable controversy. Four different hypotheses have been proposed to explain the specificity of aCL: (1) CL is directly recognized by aCL; (2) the beta 2-GPI-CL complex is the structure recognized by aCL; (3) the beta 2-GPI is the actual target antigen for aCL but is cryptic in the absence of CL; and (4) the actual epitope for aCL appears on the native structure of beta 2-GPI. We showed that aCL bound to beta 2-GPI interacting with poly-oxygenated plates and in the absence of CL, an interaction which depends on introduction of oxygen atoms on the polystyrene surface. We also showed that the beta 2-GPI bound to CL via a particular region on the fifth domain, namely C281KNKEKKC288, and the tertiary structure of the region is involved in binding to phospholipid. Several mechanisms to explain the vascular injury and thrombosis associated with aCL have been proposed, primarily based on their phospholipid reactivity to activated platelets. Whether aCL-through binding to complex of beta 2-GPI and negatively charged phospholipid in the phospholipid-dependent coagulation reactions of hemostasis contribute to the increased risk of thrombosis in patients with aCL is an important question in need of an answer. We have demonstrated the possibility that not only activated platelets but also oxidized lipoproteins, e.g., low-density lipoprotein (LDL), may be thrombogenic targets of aCL which recognize the altered beta 2-GPI structure.

Prediction of growth sensitivity of acute promyelocytic leukemia cells to granulocyte colony-stimulating factor using 7AAD/PY during administration of all-trans retinoic acid

We discussed utility of cell cycle and phenotypic analysis of acute promyelocytic leukemia (APL) cells using 7AAD/PY for the prediction of efficacy and risks of all-trans retinoic acid (ATRA) and granulocyte colony-stimulating factor (G-CSF) administration to patients with APL. Serial changes in phenotype and cell kinetics of APL cells from two patients were analyzed during ATRA administration. CD15 and CD11b were expressed on the APL cells in vivo as neutrophil maturation markers, while growth activity of the cells was decreased during ATRA administration. Using 7AAD/PY, changes in phenotype and cell kinetics were clearly detected after 2 days of cultivation with ATRA and/or G-CSF. In one patient, APL cells harvested from marrow during the first 3 weeks of ATRA administration showed distinct growth sensitivity to G-CSF ex vivo, and the cells harvested after a 4-week exposure to ATRA appeared to have lost this sensitivity. In this patient, G-CSF could be safely administered after 4 weeks of ATRA therapy. 7AAD/PY analysis is useful for predicting growth sensitivity of APL cells to G-CSF during ATRA administration.

Risks associated with cesarean sections in women with placenta previa

OBJECTIVE

To investigate the risks associated with cesarean section performed because of placenta previa.

METHODS

We retrospectively reviewed the records of 88 women with singleton pregnancies complicated by placenta previa who underwent cesarean sections and those of 176 (control) women with singleton pregnancies who required cesarean section because of complications other than placenta previa.

RESULTS

The duration of gestation was 35.3 +/- 3.6 weeks for subjects with placenta previa and 36.9 +/- 3.8 weeks for the control subjects. The mean birth weight was 2,650 g +/- 75 g for infants of women with placenta previa and 2,644 g +/- 38 g for infants of the control subjects. Blood loss during surgery was greater for women with placenta previa than for the control subjects (1,154 ml +/- 924 ml vs 632 ml +/- 357 ml, p < 0.001). Blood transfusion was required in 13 of 88 (15%) women with placenta previa, compared with 4 of 176 (2.3%) of the control subjects (p < 0.001). An emergency cesarean hysterectomy was performed on 4 of the 88 (4.5%) women with placenta previa, and in none of the control subjects (p < 0.05). The Apgar score was < or = 7 at 5 minutes in 17 infants of the 88 (22%) women with placenta previa, compared with 17 infants of the 176 (11%) control subjects among infants born at > or = 33 weeks' gestation (p < 0.05); among infants with a birth weight > or = 2,000 g, the corresponding numbers were 15 (21%) and 13 (9.2%), respectively (p < 0.05).

CONCLUSIONS

Cesarean section in the women with placenta previa was associated with increased blood loss, resulting in a blood transfusion rate 6.5 times higher than in the control subjects. These findings suggest that placenta previa might adversely affect the neonatal outcome.

Effective high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation in a patient with the aggressive form of cytophagic histiocytic panniculitis

A 20-year-old Japanese man developed generalized, subcutaneous, painless nodules, fever, abnormal liver function, serosal effusions, hepatosplenomegaly, lymphadenopathy and anemia. Skin biopsies revealed lobular panniculitis with a morphologically benign histiocytic infiltration and prominent phagocytosis. Atypical T lymphocytes were also present in the skin and liver. The diagnosis given was aggressive cytophagic histiocytic panniculitis (CHP) or aggressive subcutaneous panniculitic T cell lymphoma (SPTCL). He received cyclophosphamide, doxorubicin, and vincristine on day 1, prednisolone on days 1-5, and etoposide on days 1, 3 and 5 (CHOP-E), with the support of granulocyte colony-stimulating factor. This regimen was repeated every 2 weeks and complete clinical remission (CCR) was attained after three cycles of CHOP-E. As the clinical course of aggressive CHP is recurrent and often fatal, he was given high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (APBSCT), after five cycles of CHOP-E. He has remained in CCR for 12 months after APBSCT. High-dose chemotherapy followed by APBSCT is considered to be one of the most beneficial therapies for patients with aggressive CHP and aggressive phase SPTCL.

[Effects of long-term administration of alfacalcidol on bone mass and bone metabolism in patients with primary osteoporosis--comparison with calcium preparations]

Long-term administration of active vitamin D3 can reduce the loss of bone mass and the incidence of fractures in Japanese whose intake of calcium (Ca) is low. In a crossover study, we examined the safety and efficacy of 1 alpha (OH)D3 and combination therapy with a Ca preparation. We measured bone mass, the incidence of fractures and bone metabolism in 33 elderly patients with a high risk of fracture (mean age: 77.5 %/- 7.8 (SD) years). Subjects were randomly assigned to receive calcium lactate alone for 12 months after 12 months of combination therapy with 1 alpha (OH)D3 (1 microgram/day) (A-C group, 17 patients) or to take calcium lactate alone for 12 months and then undergo 12 months of combination therapy with 1 alpha(OH)D3 (C-A group, 16 patients). These subjects were followed for 24 months. In the A-C group, the bone mineral density (BMD) of the lumbar spine (L2-4 BMD) measured 6 months after the start of 1 alpha (OH)D3 administration was 3% higher than the baseline value. In the C-A group, L2-4 BMD measured 6 months after the start of calcium lactate administration had decreased by approximately 2%. The rate of decrease was the same 12 months after the start of administration. The differences in L2-4 BMD between the two groups 6 and 12 months after the start of administration were significant (p = 0.023 and p = 0.005, respectively). In the A-C group, the mean BMD of the distal one-third radius measured 6 months after the start of administration had increased by 5%, but the increase was 1% when measured 12 months after the start of administration. In the C-A group, there were no such changes. The incidence of vertebral fracture during combination therapy with 1 alpha(OH) D3 and Ca preparations in the A-C group was significantly lower than that in the C-A group (chi square test, p < 0.05). The serum Ca level in the C-A group gradually increased, as measured 6 and 12 months after the start of combination therapy with 1 alpha(OH) D3 and Ca preparations, although these changes were within the reference range. There was no hypercalciuria. Serum intact parathyroid hormone levels had decreased from 26.5 +/- 11.3 pg/ml and 30.7 +/- 10.3 pg/ml to 19.8 +/- 9.7 pg/ml and 25.5 +/- 9.6 pg/ml in the A-C group and the C-A group, respectively, by 6 months after the start of administration. The rate of decrease was significantly higher in the A-C group (p = 0.004). These findings suggest that long-term administration of 1 alpha(OH)D3 is safe even when combined with administration of Ca preparations, and that this agent inhibits parathyroid function, and thus prevents loss of bone mass and reduces the incidence of vertebral fracture.

Immunologic characterization and functional properties of murine antibodies raised against deleted mutants of human beta 2-glycoprotein I

beta 2-Glycoprotein I (beta 2GPI) is a 50 kDa molecule proposed as a principal target of 'autoimmune' antiphospholipid antibodies (aPL). We have used deleted mutants (DM) representing different domains of beta 2GPI (I-IV, IV-V and V) for immunization of naive mice and studied the characteristics of the respective murine IgG preparations in comparison with affinity-purified IgG from two patients with primary antiphospholipid syndrome. Immunization with beta 2GPI and with the DM produced anti-beta 2GPI antibodies, part of which reacted with negatively charged phospholipids (PL), whereas reactivity with cardiolipin was evident only in the IgG from mice immunized with beta 2GPI. These results are consistent with the presumption that aPL are induced following the in vivo association of beta 2GPI (used for immunization) with resident negatively charged PL. Accordingly, DM which either lack the PL binding site or aPL attachment locus did not elicit, upon immunization, antibodies reactive with PL. Further, murine anti-beta 2GPI IgG and human 'autoimmune' aPL were similar, albeit not identical, in terms of DM requirement for PL binding and charge dependency. Murine antibodies and human aPL, regardless of their binding characteristics, were found to bind significantly to platelets upon their activation with thrombin and to promote platelet activation. The results of the current study emphasize the dissimilarities between human 'autoimmune' aPL and murine anti-beta 2GPI. Thus, anti-beta 2GPI antibodies to different DM as well as human aPL are capable of binding and activating human platelets provided beta 2GPI is present.

Proliferative and differentiative potential of thrombopoietin-responsive precursors: expression of megakaryocytic and erythroid lineages

We investigated changes in proliferative potential and surface markers during human megakaryocytic differentiation, using megakaryocytic cells grown by thrombopoietin (TPO). Cells grown in response to TPO from CD34+ cord blood cells in a liquid culture system expressed CD41b at a frequency of 92% and CD42b at a frequency of 80% on day 10, whereas cells expressing other lineage markers constituted less than 2.5% of this population. The cultured cells were divided into CD41b-/CD42b-, CD41b+/CD42b-, and CD41b+/CD42b+ cells. Comparison of their respective proliferative potentials showed that CD41b-/CD42b- cells generated megakaryocytic progeny in response to TPO to a lesser extent, but responded to the combination of growth factors (GFs) more intensely than CD41b+/CD42b- cells. Almost all CD41b+/CD42b+ cells failed to undergo cell division. In the culture containing GFs, some CD41b-/CD42b- cells and CD41b+/CD42b- cells gave rise to erythroid as well as megakaryocytic progeny. The potential of these cells to yield erythroid progeny in response to GFs correlated well with their expression of CD34. These results suggest that TPO generates precursors with a potential to differentiate into megakaryocytic and erythroid lineages.

The best site for bronchial stapling in left and right upper lobectomies: a comparative study

Bronchial stapling and postoperative bronchoscopy was performed in 22 left upper lobectomies (LUL) and 18 right upper lobectomies (RUL). Seven LUL cases and 15 RUL cases with staples positioned 2 bronchial rings (BR) from the entrance to the upper lobe bronchus (ULB) had no residual cartilaginous rings at the stump (RCRS). Deformity of the residual bronchus (DRB) was found in 6 of these 7 LUL cases, and 3 of these 15 RUL cases (p < 0.01), with a high rate of suffering from a severe cough. The remaining 15 LUL cases and 3 RUL cases had staples positioned 3 to 4 BR from the entrance to the ULB resulting in one or two RCRS. Only one LUL case with one RCRS was accompanied by DRB and coughing. These facts strongly imply a connection between cough and DRB. DRB was frequently seen in LUL cases with no RCRS (86%), was less likely to occur in cases with one RCRS (10%), and was absent in cases with two RCRS (p < 0.01). We conclude that bronchial staples applied during a LUL should be positioned 3 or 4 bronchial rings distal from the entrance to the left ULB.

Up-regulation of cytokine mRNA, adhesion molecule proteins, and MHC class II proteins in salivary glands of TGF-beta1 knockout mice: MHC class II is a factor in the pathogenesis of TGF-beta1 knockout mice

Mice homozygous for a disrupted TGF-beta1 allele develop multiple lymphoproliferative disorders similar to those seen in the pseudolymphoma of Sjögren's syndrome. At 2 wk of age, these TGF-beta1 mutant mice begin to develop wasting syndrome and die at around 4 to 5 wk of age. We studied salivary glands from symptomatic mutant mice &gt;14 days of age. Reverse transcriptase-PCR analysis showed up-regulation of proinflammatory cytokine genes such as IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-10, and IFN-gamma in these mutant mice. Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1), and MHC class II as well as CD4-positive T lymphocyte infiltration was detected by immunostaining. To elucidate the role of MHC class II, salivary glands from TGF-beta1/MHC class II double knockout mice were used to investigate the expression of adhesion molecules and MHC class II. In spite of the existence of basal intercellular adhesion molecule-1 expression on vessels, there was neither MHC class II expression, enhanced vascular cell adhesion molecule-1 expression, nor lymphocytic infiltration in the salivary glands. These results suggest that MHC class II plays a significant role in the pathogenesis of TGF-beta1 mutant mice. Although the mechanism that initiates multiple inflammatory diseases in these mice remains unclear, the context reported here would provide insight into the immunopathology of Sjögren's syndrome.

Z-100, extracted from Mycobacterium tuberculosis strain Aoyama B, inhibits the development of collagen-induced arthritis in mice

We evaluated the effects of Z-100, extracted from human type Mycobacterium tuberculosis strain Aoyama B, on collagen-induced arthritis (CIA) in mice. One hundred thirty-five DBA/1J mice, 8 weeks of age, were assigned to 9 groups and immunized with bovine type II collagen (CII) or CFA. From the next day, Z-100 at doses of 0.004, 0.04, or 0.4 mg/kg B.W./d for 48 d was intradermally injected into the tail base. Methotrexate (MTX) at daily doses of 0.1, 0.3, or 1.0 mg/kg B.W. and cyclophosphamide (CY) at a daily dose of 5 mg/kg B.W. were used as reference drugs. The effects of these drugs on CIA mice were evaluated in terms of the incidence of CIA, the arthritis index (AI), and hind paw edema, after which the animals were sacrificed at 49 d, and both anti-CII antibody titer and delayed-type hypersensitivity (DTH) reaction were measured. In the arthritic control groups, the AI and hind paw edema were significantly increased after the second immunization on day 28. The anti-CII antibody titer and DTH reaction were significantly increased compared to normal mice on day 49. Z-100 significantly inhibited the AI at a dose of 0.4 mg/kg/d on day 49, and suppressed the incidence of both CIA and hind paw edema. Increases in both anti-CII antibody titer and DTH reaction in CIA mice were prevented by treatment with Z-100 at 0.4 mg/kg/d. MTX, in a dose-dependent manner, and CY, at a dose of 5 mg/kg/d, inhibited the incidence of CIA, AI, hind paw edema, anti-CII antibody titer and DTH reaction in CIA mice. Z-100 at a dose of 0.4 mg/kg was as effective as MTX was at a dose of 0.3 mg/kg against the DTH reaction, and it had no side effects. These results suggest the usefulness of Z-100 in patients with chronic rheumatoid arthritis.

Up-regulation of cytokine mRNA, adhesion molecule proteins, and MHC class II proteins in salivary glands of TGF-beta1 knockout mice: MHC class II is a factor in the pathogenesis of TGF-beta1 knockout mice

Mice homozygous for a disrupted TGF-beta1 allele develop multiple lymphoproliferative disorders similar to those seen in the pseudolymphoma of Sjögren's syndrome. At 2 wk of age, these TGF-beta1 mutant mice begin to develop wasting syndrome and die at around 4 to 5 wk of age. We studied salivary glands from symptomatic mutant mice >14 days of age. Reverse transcriptase-PCR analysis showed up-regulation of proinflammatory cytokine genes such as IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-10, and IFN-gamma in these mutant mice. Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1), and MHC class II as well as CD4-positive T lymphocyte infiltration was detected by immunostaining. To elucidate the role of MHC class II, salivary glands from TGF-beta1/MHC class II double knockout mice were used to investigate the expression of adhesion molecules and MHC class II. In spite of the existence of basal intercellular adhesion molecule-1 expression on vessels, there was neither MHC class II expression, enhanced vascular cell adhesion molecule-1 expression, nor lymphocytic infiltration in the salivary glands. These results suggest that MHC class II plays a significant role in the pathogenesis of TGF-beta1 mutant mice. Although the mechanism that initiates multiple inflammatory diseases in these mice remains unclear, the context reported here would provide insight into the immunopathology of Sjögren's syndrome.

Rat TAFII31 gene is induced upon programmed cell death in differentiated PC12 cells deprived of NGF

Typical programmed cell death (PCD) requires de novo macromolecular synthesis and shares common morphological changes referred to as apoptosis. To elucidate the molecular mechanism of apoptosis, we isolated cDNA clones that are induced in differentiated PC12 cells deprived of NGF by differential display method. Among such clones, homology searches revealed that the one clone encodes the rat TATA-binding-protein-associated factor TAFII31, a component of TFIID, and a transcriptional coactivator of the p53 protein. Northern analysis of various organs in human showed one band in heart, brain, skeletal muscle and pancreas, whose size is approximately 1.1 kb which identical to that of human TAFII31 mRNA, although the size of rat human TAFII31 mRNA is approximately 2.7 kb. The deduced amino acid sequence of the rat TAFII31 was 77% identical to that of the human TAFII31. Northern analysis of various organs in adult mice showed that expression levels of TAFII31 mRNA were strong in heart but weak in spleen, although this gene is ubiquitously expressed.

Progression of nephropathy in spontaneous diabetic rats is prevented by OPB-9195, a novel inhibitor of advanced glycation

Levels of tissue advanced glycation end products (AGEs) that result from nonenzymatic reactions of glucose and proteins are high in both diabetic and aging people. Irreversible AGE formation is based on increases in AGE-derived protein-to-protein cross-linking and is considered to be a factor contributing to the complications of diabetes. A novel inhibitor of advanced glycation, OPB-9195, belongs to a group of thiazolidine derivatives, known as hypoglycemic drugs; however, they do not lower blood glucose levels. We did studies to determine if OPB-9195 would prevent the progression of nephropathy in spontaneous diabetic rats. In vitro inhibitory effects of OPB-9195 on AGE formation and AGE-derived cross-linking were examined by enzyme-linked immunosorbent assay (ELISA) and SDS-PAGE, respectively. Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats, a model of NIDDM, were used to evaluate the therapeutic effect of OPB-9195. Light microscopic findings by periodic acid-Schiff (PAS) staining, the extent of AGE accumulation detected by immunohistochemical staining in the kidneys, the levels of serum AGEs by AGE-specific ELISA, and urinary albumin excretion were examined. OPB-9195 effectively inhibited both AGE-derived cross-linking and the formation of AGEs, in a dose-dependent manner in vitro. In addition, the administration of OPB-9195 prevented the progression of glomerular sclerosis and AGE deposition in glomeruli. Elevation of circulating AGE levels and urinary albumin excretion were dramatically prevented in rats, even at 56 weeks of age and with persistent hyperglycemia. We concluded that a novel thiazolidine derivative, OPB-9195, prevented the progression of diabetic glomerular sclerosis in OLETF rats by lowering serum levels of AGEs and attenuating AGE deposition in the glomeruli.

[A study on antiprothrombin antibodies in antiphospholipid syndrome]

In this study we investigated the frequency and the type of manifestations of antiprothrombin antibodies (aFII) in patients with antiphospholipid syndrome (APS). In 16 (84.2%) of 19 patients with lupus anticoagulant (LA) and either anticardiolipin antibodies or antiphosphatidylserine antibodies, two types of abnormal patterns were shown on a crossed immuno-electrophoresis technique using anti-human prothrombin murine IgG. The slow-moving peak of prothrombin was detected in 8 patients, while a peak in the other patients had the slow-moving shoulder. These slow-moving materials might represent prothrombin-aFII complexes. In 13 patients who were studied on Western blots, IgGs of 11 patients (84. 6%) bound to human purified prothrombin, and the IgGs of 7 (53.8%) of these patients also bound to human purified alpha-thrombin. Our results indicate that aFII detected in patients with APS may explain part of the mechanism of LA.

Oxidized low-density lipoprotein (Ox-LDL) but not LDL aggravates the manifestations of experimental antiphospholipid syndrome (APS)

Ox-LDL is thought to play a major role in atherogenesis. The mechanisms mediating the deleterious influences of Ox-LDL include foam cell formation and cell cytotoxicity. The production of anti-Ox-LDL antibodies results in the formation of immune complexes which are taken up at enhanced rate by macrophages, leading to foam cell formation. APS is characterized by repeated venous and arterial thromboembolic phenomena, recurrent fetal loss and thrombocytopenia, associated with the presence of antibodies to negatively charged phospholipids (aPL) (i.e. cardiolipin, phosphatidylserine). Phospholipids bear structural resemblance to LDL, and several studies have indeed proved that aPL display cross-reactivity with anti-Ox-LDL antibodies. In this study we assessed the capacity of oxidized and native forms of LDL to aggravate the clinical picture of experimentally induced APS in naive mice. Mice were actively immunized intradermally with anticardiolipin antibodies and developed a clinical picture resembling APS in humans. Subsequently, the mice were infused with either Ox-LDL, native LDL or PBS, and similar regimens were applied to controls. APS mice infused with Ox-LDL were found to exhibit a significantly more severe form of the disease in comparison with native LDL- and PBS-infused mice, expressed by lower platelet counts (261,000/mm3, 535,000/mm3 and 455,000/mm3, respectively), longer activated partial thromboplastin time (aPTT) (99 +/- 12 s, 63 +/- 8 s and 74 +/- 8 s, respectively) and higher fetal resorption rates (72.7%, 34.4% and 32.6%, respectively). The results of this study show that Ox-LDL, compared with native LDL, aggravates the clinical manifestations of experimental APS and suggest that cross-reactivity of Ox-LDL with phospholipids may provide a pathogenic explanation for this effect.

Anti-beta2-glycoprotein I (beta2GPI) monoclonal antibodies with lupus anticoagulant-like activity enhance the beta2GPI binding to phospholipids

beta2-Glycoprotein I (beta2GPI), a plasma glycoprotein with phospholipid-binding property, is known to be the actual target antigen for autoimmune type anticardiolipin antibodies (aCLs). Certain groups of aCLs (anti-beta2GPI antibodies) exert lupus anticoagulant (LA) activity and perturb the function of vascular endothelial cells. This investigation aimed at highlighting some insights into the molecular basis by which aCLs exert their biological effects by using anti-beta2GPI mAbs with well-characterized epitopes from mice and from patients with antiphospholipid syndrome. Anti-beta2GPI mAbs directed against the third domain (Cof-20 and Cof-22) and fourth domain (Cof-21, EY1C8, and EY2C9) of beta2GPI inhibited the thrombin generation induced by Russell's viper venom in diluted plasma and that induced by the prothrombinase complex reconstituted with purified clotting factors. This anticoagulant activity was abrogated in the presence of an excess amount of phospholipids, thus resembling the LA activity. In stark contrast, anti-beta2GPI mAbs directed against the fifth domain and the carboxy-terminal region of the fourth domain showed no LA-like activity. These findings suggest that the LA activity of anti-beta2GPI antibodies depends on their epitope specificity. Experiments carried out to clarify the mechanism of the LA activity showed that anti-beta2GPI mAbs with LA-like activity, but not those without this effect, enhance the beta2GPI binding to phospholipids. In addition, the F(ab')2 fragment, but not the Fab' fragment, of the anti-beta2GPI mAbs was found to enhance the LA activity and the beta2GPI binding to phospholipids, suggesting that anti-beta2GPI antibodies induce formation of multiple complexes of beta2GPI on the surface of phospholipids because of their bivalent property. This clustering of beta2GPI molecules induced by anti-beta2GPI antibodies, probably because of their multivalent property and epitope specificity, might hinder the lateral mobility and activation of clotting factors on the surface of phospholipids and thus exert LA activity. Clustering of beta2GPI molecules may also explain the molecular mechanism by which anti-beta2GPI antibodies alter the function of leukocytes and endothelial cells. The well-documented heterogeneous LA activity of aCLs (anti-beta2GPI antibodies) may also be explained by their epitope specificity.

Comparison of postural control of children with Down syndrome and those with other forms of mental retardation

To confirm the 1994 findings of Okuzumi, Haishi, and Kokubun, the displacement of the center of foot pressure, one-foot balance and head sway were measured in children with Down syndrome (n = 11) compared to those with other types of mental retardation (n = 17). The magnitudes of the displacement of the center of foot pressure and head sway were not significantly different between the Down group and other forms of mental retardation, whereas the performance of one-foot balance was significantly lower in the Down group. The mean frequencies of sway waves were generally higher in the Down group, and the differences between the two groups were significant except for sagittal head sway. The results generally supported the prior findings. We proposed that it was not the magnitude of the displacement of the center of foot pressure but rather the manner of the whole body's sway which might be related to postural control.

Serial changes of hemostasis in aneurysmal subarachnoid hemorrhage with special reference to delayed ischemic neurological deficits

This study was undertaken to elucidate comprehensively the serial changes occurring in hemostatic systems after aneurysmal subarachnoid hemorrhage (SAH) and thereby to ascertain whether the examination of the integrity of these systems is helpful in predicting delayed ischemic neurological deficits (DINDs). The authors examined 117 patients admitted to the hospital within 24 hours after onset of SAH. Blood samples were collected from each patient on Days 0 (at admission), 3, 6, 14, and 30. A number of hemostatic parameters were examined in these samples, and the relationships between their changes and DINDs were assessed. Eighteen (15.4%) of the patients exhibited DINDs, and their frequency increased as the severity of subarachnoid clotting increased. Also, the frequency of DINDs was significantly higher in the patients with hydrocephalus on initial computerized tomography (CT) scans than in those without hydrocephalus. Regarding the hemostatic parameters at admission, there was no significant difference between the patients with and without DINDs. On Day 3, however, the fibrinogen and D-dimer levels were higher in the patients with than in those without DINDs. The fibrinogen and thrombin-antithrombin complex levels on Day 6 and the D-dimer level on Day 14 in the patients with DINDs were higher than the corresponding levels in those without DINDs. Multivariate analyses revealed that the following variables (in order of importance) were independent predictors of DINDs: the levels of D-dimer on Day 3, fibrinogen on Day 6, and the presence of hydrocephalus on admission. These data indicate that the levels of hemostatic parameters in concert with the CT findings may enable us to predict the appearance of DINDs.

Protection by alpha2-macroglobulin of tissue plasminogen activator against inhibition by plasminogen activator inhibitor-1

Tissue plasminogen activator (tPA) is widely used in the treatment of acute myocardial infarction (MI). However, its thrombolytic efficacy does not correlate with the dose administered. The interactions between tPA, alpha2-macroglobulin (alpha2-M), and plasminogen activator inhibitor-1 (PAI-1) were investigated both in vitro and in patients undergoing tPA therapy for MI in an attempt to identify variables that might affect the clinical efficacy of tPA. Purified alpha2-M (5.4 mg/ml) protected 16.0% or 22.4% of tPA (12.5 IU/ml) activity from inhibition by PAI-1 at 4 or 8 IU/ml in vitro. Of nine patients treated with 5-20 mega IU of tPA for MI, the plasma activity of tPA remained increased for 15-30 min after the cessation of infusion in eight; the patient who failed to exhibit a persistent increase in tPA activity had a low plasma concentration of alpha2-M. Total tPA activity, derived from the area under the activity-versus-time curve (AUC), showed a significant inverse correlation with the ratio of the plasma PAI-1 activity to the plasma alpha2-M concentration. Total tPA activity did not correlate with plasma PAI-1 activity or plasma alpha2-M concentration alone. Results suggest that alpha2-M, by binding to tPA, protects the latter against inhibition by PAI-1.

Detection of delayed cerebral vasospasm, after rupture of intracranial aneurysms, by magnetic resonance angiography

OBJECTIVE

The goal of this study was to assess the value of magnetic resonance angiography (MRA), compared with conventional angiography, in the diagnosis and follow-up monitoring of delayed cerebral vasospasm after subarachnoid hemorrhage resulting from rupture of intracranial aneurysms.

METHODS

For 32 patients undergoing examination by both MRA and conventional angiography during the period of risk for vasospasm, on the same day, the frequency and severity of and sequential changes in vasospasm were evaluated. The three-dimensional time-of-flight method was used. MRA was performed three times, i.e., before, during, and after the period of risk for vasospasm. Conventional angiography was performed twice, i.e., at admission and during the period of risk for vasospasm. Vasospasm was assessed at 22 regions of the cerebral arteries, including the bilateral anterior cerebral (A1, A2, and A3 segments), middle cerebral (M1, M2, and M3 segments), internal carotid (C1 and C2 segments), posterior cerebral (P1 and P2 segments), and posterior communicating arteries.

RESULTS

Seven patients were excluded because of poor MRA images. Twenty-two of 25 patients (125 arteries) showed vasospasm in conventional angiograms. Nineteen of the 22 patients also showed vasospasm in MRA images; however, 57 arteries (45.6%) were diagnosed as showing vasospasm by MRA, and 59 (47.2%) could not be evaluated because of artifacts. For the remaining three patients (nine arteries, 7.2%), vasospasm could not be detected by MRA. Sequential changes in vasospasm could be well evaluated by MRA.

CONCLUSION

MRA could be useful for management of cerebral vasospasm, although it cannot become a practical alternative to conventional angiography.