Neutralization of biological activity and inhibition of receptor binding by antibodies against human thrombopoietin

Thrombopoietin (TPO) is a recently isolated cytokine that primarily regulates megakaryocytopoiesis and thrombopoiesis. We recently reported the development of a variety of antibodies (Abs) to synthetic peptides of human (h)TPO and to recombinant human TPO (rhTPO). In this study, we characterized the Abs and mapped immunologically distinct areas of the molecule. Among the five different antipeptide polyclonal Abs, only one, raised against synthetic peptide D8 to Q28, neutralized the TPO-dependent growth of FDCP-2 cells expressing human Mpl (FDCP-hMpl5 cells). One out of seven anti-rhTPO monoclonal Abs, designated as TN1, also showed neutralizing activity. TN1 was found to be specifically reactive with two proteolytic fragments, residues S1 to R117 and A60 to K122 of hTPO, indicating that the epitope(s) of TN1 is localized in residues A60 to R117 of the molecule. These two neutralizing Abs inhibited the binding of biotinylated rhTPO to FDCP-hMpl5 cells. On the other hand, the other Abs, which reacted with five polypeptides of S47 to D62, L108 to A126, N172 to A190, S262 to T284, and P306 to G332 of hTPO, did not show either the neutralizing activity or the ability to inhibit the binding of biotinylated rhTPO to the cell surface hMpl. These findings indicate that two regions, residues D8 to Q28 and A60 to R117 of hTPO, may contain the domains associated with its receptor, C-Mpl. These Abs characterized here are valuable for studying the structural analysis and the biological function of hTPO mediated by its receptor.

Photodegradation products of methylprednisolone suleptanate in aqueous solution--evidence of a bicyclo[3.1.0]hex-3-en-2-one intermediate

Two major photodegradation products of methylprednisolone suleptanate (sodium 11 beta, 17 alpha-dihydroxy-6 alpha-methyl-21-[[8-[methyl(2-sulfoethyl)amino]-1,8-dioxooctyl+ ++]oxy]-pregna-1,4-diene-3,20-dione) in aqueous solution irradiated with white fluorescent light at 2000 lux for 28 days at 25 degrees C were isolated by preparative high-performance liquid chromatography and characterized. Structures of the photodegradation products were determined as sodium 11 beta,17 alpha-dihydroxy-5 alpha, 6 alpha-dimethyl-21-[[8-[methyl(2-sulfoethyl)amino]-1,8-dioxoocty l]-oxy]-19-norpregna-1(10),3-diene-2,20-dione and sodium 1 beta, 11 beta-epoxy-17 alpha-hydroxy-6 alpha-methyl-21-[[8-[methyl(2-sulfoethyl)amino]-1, 8-dioxooctyl]oxy]-19 alpha-pregn-4-ene-2.20-dione. Formation of these compounds, especially the 1,11-epoxy analogue, strongly supports the existence of the bicyclo[3.1.0]hex-3-en-2-one intermediate in the photorearrangement of steroidal cross-conjugated dienones. The intermediate can account for all the major ketonic and phenolic products; these products are generated from the intermediate after subsequent transformations and/or further skeletal rearrangements. The 1,11-epoxy analogues were obtained from the prednisolone steroids in high yields by irradiation with a high-pressure mercury lamp.

Regulation of hepatic thrombopoietin production by portal hemodynamics in liver cirrhosis

OBJECTIVE

This study was designed to clarify how thrombopoietin (TPO) functions in and, to some extent, causes thrombocytopenia complicating liver cirrhosis and portal hypertension.

METHODS

Our study population consisted of 19 cirrhotic and six noncirrhotic patients who underwent percutaneous transhepatic portography (PTP) and hepatic venography.

RESULTS

The platelet counts of the cirrhotic patients were significantly lower than those of the noncirrhotic patients (8.7 +/- 4.1 vs 17.4 +/- 7 x 10(4)/microl; p < 0.01). The flow direction in the splenic vein was confirmed by PTP. Ten hepatofugal and nine hepatopetal flow directions in the splenic vein were noted among the cirrhotics. The hepatofugal group showed lower portal venous pressure (20 +/- 10 vs 32 +/- 4 cm H2O; p < 0.01) than the hepatopetal group and had a higher incidence of hepatic encephalopathy (six of 10 vs zero of nine; p < 0.01). The hepatic vein-portal difference in TPO did not differ substantially between the cirrhotics and noncirrhotics (0.12 +/- 0.04 vs 0.24 +/- 0.07 fmol/ml). Comparisons of this value among the three groups showed the TPO difference to be lowest in the hepatofugal group (hepatofugal: 0.04 +/- 0.03, hepatopetal: 0.21 +/- 0.07, noncirrhotic: 0.24 +/- 0.07; p < 0.05).

CONCLUSIONS

Our findings suggest that TPO production in the cirrhotic liver is regulated by the portal blood supply to the liver. Thus, portal hemodynamics may play a critical role in the development of thrombocytopenia.

Plain CT findings of brain death confirmed by hollow skull sign in brain perfusion SPECT

Computed tomographic (CT) findings of 13 patients manifesting brain death were reviewed. This diagnosis was confirmed by the so-called "hollow skull" pattern observed in brain perfusion single photon emission computed tomography (SPECT), which was performed between 4 hours before and 3 days after the CT scans, and by subsequent corporal death. The brain perfusion SPECT was performed with the intravenous administration of technetium (Tc)-99m-hexamethylpropyleneamine oxime (HMPAO) or iodine (I)-123-N-isopropyl-p-iodoamphetamine (IMP). CT scans showed diffuse cerebral edema and the loss of gray-white matter differentiation in all the cases, and transtentorial herniation in 12 patients. These CT findings were considered predictive of brain death.

Increased serum levels of thrombopoietin in patients with thrombotic thrombocytopenic purpura, idiopathic thrombocytopenic purpura, or disseminated intravascular coagulation

The serum levels of thrombopoietin (TPO) were measured in 16 patients with thrombotic thrombocytopenic purpura (TTP), 12 with hemolytic uremic syndrome (HUS), 10 with aplastic anemia (AA), 10 with disseminated intravascular coagulation (DIC), and 71 with idiopathic thrombocytopenic purpura (ITP). The serum TPO levels were measured with a sensitive sandwich enzyme-linked immunosorbent assay. The serum TPO level in the ITP group (1.68 +/- 0.85 fmol/ml) were not significantly increased compared with those of the normal subjects. The TPO levels in the TTP (2.77 +/- 1.38 fmol/ml) and HUS groups (5.77 +/- 4.41 fmol/ml) were higher than those of the normal subjects. The patients with AA (12.7 +/- 8.0 fmol/ml) and those with DIC (13.3 +/- 5.7 mol/ml) had significantly higher serum TPO levels than did the normal subjects and ITP patients. The TPO levels were well correlated with the platelet counts in the TTP patients, and were negatively correlated with the platelet counts in the ITP patients. These results suggest that the serum TPO levels in some thrombocytopenic diseases are regulated not only by the platelet count and the megakaryocyte mass, but also by other factors.

Effects and serum levels of thrombopoietin in a case of chronic thrombocytopenia with achondroplasia

Thrombopoietin (TPO), produced mainly in the liver, is a major regulator of platelet production. Serum TPO levels are generally increased in thrombocytopenia. We report a case of a 12-year-old boy with chronic severe thrombocytopenia, achondroplasia and nephritis. Severe chronic thrombocytopenia was found at 9 months of age. It was resistant to any treatment. Studies on megakaryocytic colonies in vitro revealed that the marrow cells responded well to TPO and no plasma inhibitor was found. Although hepatic function test results were normal, serum TPO levels in the patient (0.94 fmol/ml) were consistent with those in age-matched children (0.49-1.75 fmol/ml). Chronic thrombocytopenia requires individual evaluation before clinical trials with TPO.

Measurement of endogenous plasma thrombopoietin in patients with acquired aplastic anaemia by a sensitive enzyme-linked immunosorbent assay

We measured the endogenous plasma concentration of thrombopoietin (TPO) in 76 patients with acquired aplastic anaemia (AA) by a sensitive sandwich enzyme-linked immunosorbent assay (ELISA). The plasma TPO concentrations were significantly higher in AA patients when compared to healthy control subjects (P < 0.0001) and there was a significant negative correlation between plasma TPO concentrations and platelet counts in 54 AA patients who had not received any platelet transfusions prior to sampling. On the other hand, there was no statistically significant correlation between the TPO concentrations and platelet counts in 22 AA patients who had previously received platelet transfusions. We studied serial changes of plasma TPO concentration in 24 patients who showed an increase in their platelet counts following bone marrow transplantation or immunosuppressive (IS) therapy. Although a decrease in plasma TPO concentration was observed, levels remained above the range of normal healthy controls even in the patients who attained normal platelet counts following therapy. A decrease in TPO concentrations was observed in only half of the responders to IS therapy. Whether exogenous TPO will result in increased platelet counts in AA patients with high TPO levels remains to be determined.

Advanced imaging of carcinoma of the mandibular gingiva

OBJECTIVE

To evaluate the validity of MRI in detecting spread of mandibular gingival carcinoma within the bone marrow. SCHEME: Three patients with mandibular gingival carcinoma were examined by panoramic radiography, CT, MRI and radionuclide scanning. The resected mandibles were examined histologically for invasion of bone marrow by the tumor.

RESULTS

With MRI the bone marrow in all cases had a low signal intensity on the T1-weighted images, a high signal intensity on the T2-weighted, and high signal intensity on the contrast-enhanced T1-weighted. In one case there was an obvious evidence of tumor invasion of the bone marrow histologically, but in two cases only dilatation of the blood vessels and evidence of hemorrhage associated with tumor.

CONCLUSION

MRI is not specific for detecting tumor invasion of bone marrow in mandibular gingival carcinoma.

Interferon increases serum thrombopoietin in patients with chronic hepatitis C

We measured serum thrombopoietin (TPO) in chronic hepatitis C treated with interferon (IFN). The platelet count before the therapy was 161.9 x 10(9) +/- 64.1 x 10(9)/l, which decreased to 116.3 x 10(9) +/- 48.4 x 10(9)/l 1 week after IFN therapy (P < 0.01). On the other hand, serum TPO increased from 1.96 +/- 0.60 fmol/ml to 2.68 +/- 0.69 fmol/ml (P < 0.02). Contrary to a recent report that serum TPO was not altered in liver cirrhosis, these data indicate that serum TPO was increased in chronic hepatitis C in response to thrombocytopenia by IFN therapy.

Isolation and partial amino acid sequence of bacteriocins produced by Lactobacillus acidophilus

Bacteriocins produced by Lactobacillus acidophilus JCM 1023, JCM 1028, JCM 1021, JCM 1229, and JCM 5342 were active against closely related lactobacilli. These bacteriocins were purified and partial sequenced. Bacteriocin activities of L. acidophilus JCM 1023 and JCM 1028 were associated with two components. On the basis of N-terminal amino acid sequencing and the molecular masses, it is interpreted that these two-component bacteriocins are identical to acidocin J1132, a bacteriocin from L. acidophilus JCM 1132 [Tahara et al., Appl. Environ. Microbiol., 62, 892-897 (1996)]. Other bacteriocins were single-peptide bacteriocins.

Isolation and partial characterization of bacteriocins produced by Lactobacillus gasseri JCM 2124

Four antibacterially active peptides (B1 to B4) were purified from the culture broth of L. gasseri JCM 2124. The B2 peptide (gassericin B2) was determined to be 4400 Da by mass spectrometry and partially sequenced. Gassericin B2 did not show any sequence similarities to other known bacteriocins. The B1 and B3 peptides shared identical sequences with two peptides of a two-component bacteriocin from Lactobacillus acidophilus. However, synergistic activity upon complementation of B1 and B3 was not observed. Based on amino acid sequencing and molecular mass, it is suggested that B1 and B4 peptides were derived from B3 (gassericin B3).

Isolation, partial characterization and mode of action of acidocin J1229, a bacteriocin produced by Lactobacillus acidophilus JCM 1229

Lactobacillus acidophilus JCM 1229 produces a heat-stable bacteriocin, designated as acidocin J1229, that has a narrow inhibitory spectrum. Production of acidocin J1229 in MRS broth was pH dependent, with maximum activity detected in broth culture maintained at pH 5.0. Acidocin J1229 was purified by ammonium sulphate precipitation and sequential cation exchange and reversed-phase chromatographies. The sequence of the first 24 amino acid residues of the N terminus of acidocin J1229 was determined. The molecular mass of acidocin J1229 as determined by mass spectrometry was 6301 Da. Acidocin J1229 showed a bactericidal effect but not a bacteriolytic effect on sensitive cells. Acidocin J1229 dissipated the membrane potential and the pH gradient in sensitive cells, which affected such proton motive force-dependent processes as amino acid transport. Acidocin J1229 also caused an efflux of glutamate, previously taken up via a unidirectional ATP-driven transport system. Secondary structure prediction revealed the presence of an amphiphilic alpha-helix region that could form hydrophilic pores. These results suggest that acidocin J1229 is a pore-forming peptide that creates cell membrane channels through the "barrel-stave' mechanism.

Circulating endogenous thrombopoietin, interleukin-3, interleukin-6 and interleukin-11 levels in patients undergoing allogeneic bone marrow transplantation

To elucidate the physiologic role of thrombopoietin (TPO) for hematologic reconstitution following allogeneic bone marrow transplantation (BMT), serum TPO levels as well as interleukin-3 (IL-3), IL-6 and IL-11 were serially measured in 55 samples from 3 patients who underwent allogeneic BMT using an enzyme-linked immunosorbent assay (ELISA). The TPO level was higher in the serum taken during marrow aplasia than in the pretransplant serum. The serum TPO levels and platelet counts showed a strong inverse relationship in all patients examined. We also sequentially measured endogenous serum TPO levels before and within 36 h after platelet transfusions. Endogenous serum TPO levels were inversely correlated with platelet mass following platelet transfusions. Serum levels of IL-3 had no apparent correlation with platelet counts and serum levels of IL-11 remained below the detection levels (31.3 pg/ml) in all samples. Serum levels of IL-6 were high during myeloaplasia and more upregulated in the febrile period. These findings support the view that TPO is the central regulator for megakaryopoiesis in vivo and the rationale for its clinical use after allogeneic BMT.

Serum thrombopoietin (TPO) levels in patients with amegakaryocytic thrombocytopenia are much higher than those with immune thrombocytopenic purpura

We assayed serum thrombopoietin (TPO) levels in amegakaryocytic thrombocytopenia (AMT) and immune thrombocytopenic purpura (ITP) patients by using a newly established enzyme-linked immunosorbent assay (ELISA). TPO levels in AMT patients were quite high (mean +/- SD = 13.7 +/- 11.2 fmoles/ml, n = 4), whereas those in ITP patients were only slightly higher (1.25 +/- 0.39, n = 12) than those of the healthy donors (0.55 +/- 0.2, n = 20). Furthermore, in ITP patients no correlation was observed between platelet counts and serum TPO levels (correlation coefficient = 0.14). We further assayed serum TPO levels sequentially during steroid treatment in patients with AMT and ITP. In one AMT patient serum TPO levels started to decrease in accordance with the increase of megakaryocyte counts, which preceded the increase in platelet counts. However, in ITP patients serum TPO levels did not change significantly throughout the course of the treatment despite the recovery of platelet counts. Based on these findings, we conclude that serum TPO levels may be regulated at least in part by megakaryocyte counts.

Functional analysis of the cytoplasmic domain of the human Mpl receptor for tyrosine-phosphorylation of the signaling molecules, proliferation and differentiation

To investigate the functional domains for signal transduction of human Mpl, we constructed a series of human c-mpl cDNAs with various deletions in the cytoplasmic domain, and then introduced each cDNA into murine IL-3-dependent myeloid leukemia FDC/P2 cells to establish stable transformants. We examined the growth and differentiation responses and tyrosine phosphorylation of the intracellular signaling proteins including Jak2, Tyk2, Stat3, Stat5, Vav, SHPTP2, Cbl, Shc and Shc-associated p145 when receptor stimulation occurred after thrombopoietin (TPO) binding. TPO stimulated cell proliferation and induced the expression of megakaryocyte lineage-specific AP-51 and CD61 cell surface antigens and tyrosine phosphorylation of the signaling proteins in transformants expressing full length human Mpl. These results suggested that Mpl not only induced proliferation but also transduced megakaryocyte-specific differentiation signals into FDC/P2 cells. Mutational analysis of human Mpl indicated that the N-terminal region of its cytoplasmic domain is necessary and sufficient to transduce proliferation and differentiation signals into cells, while the C-terminal region may also play important roles in transducing the differentiation signals.

Serum thrombopoietin (c-Mpl ligand) levels in patients with liver cirrhosis

To clarify the role of c-Mpl ligand (thrombopoietin: TPO) in liver cirrhosis (LC), we examined serum TPO levels (sTPO) in patients with LC (N = 44), chronic hepatitis (CH; N = 13) and healthy controls (N = 41) by an enzyme-linked immunosorbent assay. Although platelet counts of all LC patients (89 +/- 59 x 10(9)/l; mean +/- SD) were lower than those of controls and CH patients, sTPO levels in LC patients (1.23 +/- 0.51 fmol/ml) were the same as those in controls (1.22 +/- 0.37) and CH patients (1.18 +/- 0.36). Platelet counts were significantly higher in splenectomized patients than in unsplenectomized patients, but the sTPO level did not differ between these two groups. In LC patients, the sTPO level was not correlated with the platelet count, but was correlated with prothrombin time, activated partial thromboplastin time, and total bilirubin, indicating that production of TPO in the liver decreases slightly with the development of liver dysfunction. Our findings suggest that production of TPO is maintained in LC patients and their thrombocytopenia is not due to a defect in platelet production.

Serum thrombopoietin level in various hematological diseases

To investigate the pathophysiological role of thrombopoietin (TPO) in thrombopoiesis, we measured its serum levels in 15 healthy individuals, 84 patients with various hematological diseases and 2 patients with liver cirrhosis using an enzyme immunoassay procedure. The TPO level was 0.84 +/- 0.40 f mol/ml in normal individuals. TPO levels were considerably elevated in patients with myelosuppression after intensification chemotherapy of acute leukemia in complete remission (postchemotherapy group; n = 18; 18.46 +/- 9.70 f mol/ml). When the data of normal individuals and the postchemotherapy group were combined, TPO levels were inversely correlated with the platelet count in this combined group. We compared these data of normal individuals and the postchemotherapy group with various hematological disease states. In aplastic anemia (n = 13; 16.03 +/- 9.44 f mol/ml), acute lymphoblastic leukemia (n = 5; 10.36 +/- 5.57 f mol/ml), malignant lymphoma (n = 6; 2.79 +/- 2.27 f mol/ml), multiple myeloma (n = 3; 3.34 +/- 0.20 f mol/ml) and chronic lymphocytic leukemia (n = 2; 1.71 +/- 3.91 f mol/ml), the relationship of serum TPO levels and platelet counts was almost the same as in the combined group with normal individuals and the postchemotherapy group. However, the TPO levels were slightly higher in myeloproliferative disorders (n = 12; 1.99 +/- 1.47 f mol/ml) and lower in acute myelogenous leukemia (n = 8; 2.27 +/- 1.25 f mol/ml), hypoplastic leukemia (n = 3; 2.76 +/- 2.23 f mol/ml), myelodysplastic syndrome (n = 2; 0.42 +/- 0.60 f mol/ml), liver cirrhosis (n = 2; 1.50 +/- 0.92 f mol/ml) and idiopathic thrombocytopenic purpura (n = 12; 2.08 +/- 1.41 f mol/ml), when compared to the regression line for the combined group with normal individuals and postchemotherapy group. These findings suggest that TPO might play an important role in regulation of the platelet count in normal and pathological conditions.

Regulation of serum thrombopoietin levels by platelets and megakaryocytes in patients with aplastic anaemia and idiopathic thrombocytopenic purpura

To clarify the regulatory mechanism of thrombopoietin (TPO, c-Mpl ligand) in chronic thrombocytopenic conditions, we determined TPO levels in the sera of patients with aplastic anaemia (AA; n = 26) and idiopathic thrombocytopenic purpura (ITP; n = 32) by an enzyme-linked immunosorbent assay. Despite a similarity in platelet counts, serum TPO levels in the AA group were markedly higher than those in the ITP group: 20.41 +/- 9.71 f mol/ml (mean +/- SD) and 1.66 +/- 0.55 f mol/ml, respectively, both of which were significantly elevated compared to normal subjects (n = 41; 1.22 +/- 0.37). In both groups, serum TPO level showed an inverse correlation with the platelet count. We determined the megakaryocyte volume using bone marrow clot section and found that it was markedly small in the AA group; while in the ITP group it was augmented with a correlation to serum TPO level. Our findings suggest that TPO levels may be regulated not only by platelets but also megakaryocytes in AA and ITP.

Serum thrombopoietin and plasma glycocalicin concentrations as useful diagnostic markers in thrombocytopenic disorders

Using enzyme-linked immunosorbent assays, we measured the concentrations of serum thrombopoietin (TPO) and plasma glycocalicin, a proteolytic fragment of platelet glycoprotien Ib alpha, in 13 patients with myelodysplastic syndrome (MDS), aplastic anaemia (AA) or idiopathic thrombocytopenic purpura (ITP). In the patients with AA or MDS, the TPO concentrations were remarkably increased, and their glycocalicin concentrations were decreased compared with the normal control individuals. In the patients with ITP, however, the TPO and glycocalicin levels were not changed as much as in the AA/MDS patients in spite of the same degree of thrombocytopenia. During immunosuppressive treatment of ITP patients, there was an inverse relationship between the level of TPO and the platelet count. Thus, measurements of TPO and glycocalicin levels are useful for the diagnosis of thrombocytopenia, and our results from ITP patients did not support the model which suggested the simple feedback regulation of TPO in thrombocytopenia.

Cyclic change of cytokines in a patient with cyclic thrombocytopenia

The serial change of various cytokines in the serum from a patient with cyclic thrombocytopenia is described. Interleukin 7, stem cell factor, and transforming growth factor beta 1 synchronized with the platelet count, and there was a significant positive correlation between the three cytokines and the platelet count. Levels of macrophage colony-stimulating factor, thrombopoietin, platelet-associated IgG and erythropoietin changed reciprocally with the platelet count, and there was a significant negative correlation between the platelet count and these cytokines except erythropoietin. No cyclic change was observed in IL-3, IL-6, IL-11, granulocyte-macrophage colony-stimulating factor, or leukaemia inhibitory factor. These observations suggest that this disease involves two cyclic changes: megakaryocytopoiesis and platelet destruction, in both of which the cytokines play an important role.

A sensitive sandwich ELISA for measuring thrombopoietin in human serum: serum thrombopoietin levels in healthy volunteers and in patients with haemopoietic disorders

A sensitive sandwich enzyme-linked immunosorbent assay (ELISA) has been established to estimate serum thrombopoietin (TPO) concentrations in healthy volunteers and patients with haemopoietic disorders. The ELISA uses a mouse monoclonal antibody (Ab) as the capture Ab and a biotinylated rabbit polyclonal Ab as the detector. The ELISA was reproducible, highly sensitive and specific for human TPO. The coefficients of intra-and inter assay variation were from 3.0% to 4.9% and from 5.9% to 6.1%, respectively. The quantitative limit of the ELISA was 0.09 fmol/ml in serum. The quantitative limit was lower than the normal level. The dose-response curves of serum samples from healthy volunteers and patients with haemopoietic disorders were parallel to the standard curves. The ELISA did not cross-react with a variety of blood components and cytokines to produce false-positive results. The serum TPO concentrations from 29 normal males and 21 females were 0.79 +/- 0.35 and 0.70 +/- 0.26 fmol/ml, respectively. Serum TPO levels in patients with aplastic anaemia (AA), acute lymphocytic leukemia (ALL) and essential thrombocythaemia (ET) were measured using the ELISA. The serum TPO levels in the patients with ET (n = 6, 2.80 +/- 1.55 fmol/ml) were higher than the normal level. The patients with AA (n = 7, 18.53 +/- 12.37 fmol/ml) and ALL (n = 5, 10.36 +/- 5.57 fmol/ml) had significantly higher serum TPO levels than normal individuals. These results indicate that the ELISA specific to TPO should prove useful in measuring the TPO concentration in serum samples.

Circulating thrombopoietin level in chronic immune thrombocytopenic purpura

The circulating thrombopoietin (TPO) level in 43 patients with chronic immune thrombocytopenic purpura (ITP) was examined by an ELISA system. The TPO level (mean +/- SD) in ITP patients was mildly elevated (1.86 +/- 1.17 fmol/ml) compared to that in normal subjects (0.76 +/- 0.21), and was within the normal range in 30% of ITP patients. In contrast, the TPO level in patients with aplastic anaemia was very high, 12.35 +/- 6.42 fmol/ml. There was no correlation between TPO level and platelet count in ITP patients. Splenectomy was performed in two ITP patients, after which platelet counts increased to normal levels and TPO levels showed a transient increase. These data suggest that reactive TPO production against thrombocytopenia in ITP is small when compared to that in aplastic anaemia. Relative endogenous TPO deficiency may play some role in the pathophysiology of thrombocytopenia in ITP patients.

Isolation, partial characterization, and mode of action of Acidocin J1132, a two-component bacteriocin produced by Lactobacillus acidophilus JCM 1132

Lactobacillus acidophilus JCM 1132 produces a heat-stable, two-component bacteriocin designated acidocin J1132 that has a narrow inhibitory spectrum. Maximum production of acidocin J1132 in MRS broth was detected at pH 5.0. Acidocin J1132 was purified by ammonium sulfate precipitation and sequential cation exchange and reversed-phase chromatographies. Acidocin J1132 activity was associated with two components, termed alpha and beta. On the basis of N-terminal amino acid sequencing and the molecular masses of the alpha and beta components, it is interpreted that the compounds differ by an additional glycine residue in the beta component. Both alpha and beta had inhibitory activity, and an increase in activity by the complementary action of the two components was observed. Acidocin J1132 is bactericidal and dissipates the membrane potential and the pH gradient in sensitive cells, which affect such proton motive force-dependent processes as amino acid transport. Acidocin J1132 also caused efflux of preaccumulated amino acid taken up via a unidirectional ATP-driven transport system. Secondary structure prediction revealed the presence of an amphiphilic alpha-helix region that could form hydrophilic pores. These results suggest that acidocin J1132 is a pore-forming bacteriocin that creates cell membrane channels through the "barrel-stave" mechanism.

Coexpression of thrombopoietin and c-mpl genes in human acute myeloblastic leukemia cells

Thrombopoietin (TPO) is a recently identified hematopoietic growth factor that is essential for the growth and development of megakaryocytes. We have previously shown that TPO induces proliferation of acute myeloblastic leukemia (AML) cells in vitro. In this study, we have examined the expression of TPO and its receptor c-mpl in a series of AML cases and human leukemia cell lines. The mRNA transcripts of TPO were detectable in 18 of 50 AML cases and in some myeloid leukemia cell lines (HEL, M07E and CMK) by means of reverse transcriptase polymerase chain reaction (RT-PCR). In addition, TPO transcripts were coexpressed with c-mpl transcripts in 10 of 50 AML cases and in HEL, M07E and CMK cells. With regard to the French-American-British (FAB) classification, coexpression OF TPO and c-mpl was observed with high frequency in AML cases of M7-type. Despite the TPO expression in a substantial fraction of leukemia cells, biological activity of TPO was not found in the conditioned medium that was obtained from cultivation of TPO mRNA-positive leukemia cells. These results suggest that TPO may not commonly participate in the abnormal growth of AML cells as an extracellular autocrine growth factor.

[Diagnostic value of high N-isopropyl-p-[123I] iodoamphetamine (IMP) uptake in brain tumors]

The diagnostic value of high N-isopropyl-p-[123I] iodoamphetamine (123I-IMP) uptake in histologically proven intracranial tumors was evaluated in 54 patients with both early (15-35 min after injection) and delayed (4 hours) SPECT before treatment. Higher uptake in the tumor compared with normal cerebral cortex was observed in early scans in all of the five patients with primary intracranial malignant lymphoma, in two of 16 meningiomas, two of seven astrocytomas, one of three pituitary adenomas, and one central neurocytoma. Among these 11 cases all the malignant lymphomas showed persistent high uptake in delayed scans, whereas other tumors showed decreased uptake in delayed scans. This persistent high 123I-IMP uptake was characteristic of primary intracranial malignant lymphomas and was useful in the diagnosis of intracranial malignant lymphoma.

Cloning and nucleotide sequence of the gene for acidocin 8912, a bacteriocin from Lactobacillus acidophilus TK8912

Acidocin 8912 is a bacteriocin produced by Lactobacillus acidophilus TK8912. The acidocin 8912 structural gene, acdT, was cloned and determined. It was located on the 14-kb plasmid pL103 and encoded a 46 amino acid precursor including a 20 amino acid N-terminal extension. The precursor sequence of the acdT gene shows a conservation of the general structural characteristics of the bacteriocin precursors from some lactic acid bacteria.

Hurler syndrome with severe complication in post-bone marrow transplantation course: life threatening interstitial pneumonitis and hypertension

Bone marrow transplantation (BMT) was performed in a 3 year old patient with Hurler syndrome. The post-BMT course was complicated by interstitial pneumonitis and severe hypertension, which were life threatening. The patient responded well to therapy and recovered. BMT in this patient resulted in significant clinical improvement in the signs and symptoms of Hurler syndrome. Biochemical improvement, including elevated alpha-L-iduronidase activity in white blood cells and decreased urinary glycosaminoglycan excretion was significant. However, skeletal and neurological impairment were not improved. We conclude that BMT for Hurler syndrome should be performed at an earlier stage, before severe neuronal damage has occurred. Moreover, BMT is a high risk procedure and there will always be a possibility that life threatening complications will occur, as in our case.

Identification of the replication region of Lactobacillus acidophilus plasmid pLA103

The structure of the region necessary for replication of the plasmid pLA103 from Lactobacillus acidophilus TK8912 has been characterized. Sequence analysis revealed that the replication region contained an open reading frame (OrfA) encoding a 282-amino acid peptide preceded by a 22-bp tandem repeat sequence region. The predicted OrfA protein showed homology to the replication protein of a plasmid from Pediococcus halophilus. The plasmid containing the repeat sequence region preceding OrfA was able to replicate in the Lactobacillus host when provided with OrfA in trans, suggesting that the repeat sequence region contains the origin sequence essential for the pLA103 replication.

NMR spectroscopic characterization of adinazolam mesylate: pH-dependent structure change in aqueous solution and active methylene

The present study is to investigate structural changes of adinazolam mesylate in aqueous solution under various pH conditions by NMR spectroscopy. By plotting of the signal integration and chemical shifts of the side chain, pKa values for imine hydrolysis and the side chain amine were determined. Conformational analysis of the side chain was performed with deuterium-induced isotope effects on chemical shifts, nuclear Overhauser effects, relaxation times, and energy calculations. Hydrogen/deuterium exchange due to an active methylene at the 4-position under basic conditions was revealed.

Expression of laminin in vestibular ganglia and nerves in herpes simplex virus infectious chick embryo

The expression of laminin in the vestibular ganglia and nerves in herpes simplex virus I (HSV-I) infectious chick embryos was examined by immuno-histochemistry. In 9-day-old normal chick embryos, the surface of the vestibular ganglion cells and the vestibular nerves were labelled with laminin, while, in HSV-I infectious chick embryos, the staining of laminin in the vestibular ganglia and nerves was very weak. These results suggest that HSV-I injures vestibular ganglia and nerves, and that laminin is a good marker of the degeneration and innervation of developing vestibular nerves.

Neurotological evaluation of Harada's disease

We have had 30 patients with Harada's disease at our clinic from 1980 to 1993 and their neurotological findings were retrospectively reviewed. There were 12 males and 18 females, whose ages ranged from 15-years to 67-years. Preceding symptoms such as headache or common cold were observed in 50% of the patients. Pleocytosis of the cerebrospinal fluid was found in 89% of the patients. Subjective cochlear and/or vestibular symptoms were noted in 60% of the patients. In 43 of the 50 ears, sensorineural hearing loss (< 40 dB) was observed. In 77% of the patients, vestibular function tests gave abnormal results. On the basis of our findings, it was suggested that Harada's disease with vertiginous and cochlear symptoms could be classified as follows: cochlear type, peripheral vestibular type, cochleovestibular type, central type, and 'unclassified', based on the neurotological results.

Effect of hypergravity on vestibular compensation in guinea pigs

The effect of hypergravity on vestibular compensation was studied in guinea pigs. Pharmacological labyrinthectomy was performed by injecting chloroform into the middle ear cavity under ether anesthesia. The guinea pigs were exposed to hypergravity on a centrifuge. The animals were divided into four groups: a group stimulated with 2G after labyrinthectomy of the right ear, a group stimulated with 2G after labyrinthectomy of the left ear to evaluate the influence of the centrifugal rotation, a group stimulated with acceleration and deceleration alone, and a control group which was maintained under similar conditions, but without centrifugation. Head deviation and nystagmus were recorded and analysed to assess the process of compensation at 1, 3, 5, 7 and 9 h after labyrinthectomy. The 2G-stimulated group showed faster compensation in head deviation than the control group. In this study, the hypergravity stimulation seemed to facilitate the compensation in head deviation.

Early onset of cecal perforation in neonatal, recto-sigmoid type Hirschsprung's disease

Hirschsprung's disease has been considered to cause intestinal perforation in rare cases. Even if a perforation occurs, the majority of cases are associated with the long-segment or total colonic type. Our case developed the perforation in the neonatal period in spite of being of the recto-sigmoidal type, and it affected the cecum. We do not have a good explanation for this condition. However, the pathological examination of the specimens of the perforated cecum revealed some necrosis (ulceration, subcutaneous hemorrhage, congestion and severe edema) which was considered to be caused by ischemia, secondary to a localized vascular accident in the wall of the distended intestine.

Choristoma of the nasopharynx

A choristoma is a tumor-like mass consisting of tissues that are foreign to the site at which they are located. A hamartoma, on the other hand, is a tumor-like mass consisting of tissues that are native to the site of origin. We report a choristoma in the nasopharynx that consisted of normal skin tissue.

[Equilibrium of small animals in "drop shaft" experimentation--preliminary study on the frog with vestibular neurectomy]

We have newly designed instruments for equilibrium experimentation, using a drop shaft, and studied the behavior and EMG Patterns of frogs with or without unilateral vestibular neurectomy, as a preliminary study at JAMIC (Japan Microgravity Center). The results are reported herein and the efficacy of the drop shaft in equilibrium experimentation is also documented. 1) In unilateral vestibular neurectomized frogs, posture--head tilt, leg flexion on the affected side, and leg extension on the opposite side--is maintained and persists under microgravity. Rolling to the affected side was also observed. 2) The latencies of the EMG responses from M. tibialis anticus and M. longissimus dorsi were prolonged on the affected side. 3) The frog is suitable for use in equilibrium experiments utilizing a drop shaft. 4) The JAMIC drop shaft can be used to obtain constant and stable microgravity, 10(-4) G for 10 sec, which is similar to that in space. Drop shafts are suitable for equilibrium experimentation.

[Relapse of acute leukemia after allogeneic bone marrow transplantation]

The relapses of 45 acute leukemia patients who underwent allogeneic bone marrow transplantation between April 1976 and February 1992 were analyzed clinically. The relapse rates of acute nonlymphocytic leukemia (ANLL) and acute lymphocytic leukemia (ALL) were 4/26 (15%) and 9/19 (47%), respectively. Although multivariate analysis could not be done, a high frequency of leukemia relapse was significantly associated with ALL, a younger age, history of extramedullary leukemia and blood-type identity. Chromosomal abnormalities at diagnosis, interval from diagnosis to bone marrow transplantation (BMT) and graft-versus-host disease (GVHD) prophylaxis were likely to be predictive of relapse. On the other hand, neither stage of leukemia at BMT, acute GVHD, sex, nor WBC count at diagnosis was a predictive factor. Eight of 10 relapsed patients achieved complete remission posttransplant, but the duration of remission was only 138 days on average. Four second BMT procedures for relapsed leukemia were carried out but were associated with many complications. However, one is alive well over 6 years after the second transplantation. There is a high treatment-related mortality following second BMT, but there is some possibility of long survival in some patients.

[Effect of retroauricular galvanic stimulation on muscle atrophy in the unweighted rat hindlimb]

Hindlimb unweighting in the rat may serve as an experimental model simulating muscle atrophy under weightlessness. As a preventive measure, retroauricular galvanic stimulation was delivered to the unweighted rat hindlimb and the weights of the bilateral soleus and gastrocnemius muscles were compared. Wistar rats, with unweighted hindlimbs, were divided into two groups; the control group which received no galvanic stimulation and a galvanically stimulated group which received galvanic stimulation (bipolar biauricular, 1 mA in intensity, 500 msec in duration, 1 Hz in frequency) for one hour twice a day for 7 days using an electronic stimulator made by NIHON-KODEN (MODEL SEN-1101). The weights of the soleus and gastrocnemius muscles on both sides were measured in each group using a balance (METTLER AT201). The results were as follows: 1. Muscle weights in the galvanically stimulated group were greater than those in the control group. 2. A statistically significant difference between right and left soleus muscle weights was obtained in the galvanically stimulated group (P < 0.01). 3. We found no significant difference between the two sides in the weights of gastrocnemius muscles. It is presumed that retroauricular galvanic stimulation exerts some influence, not only on vestibular organs, but also on hindlimb muscles through the lateral vestibulo-spinal tract and, in addition, through the spinal motor neuron. Therefore, we speculate that galvanic stimulation might prevent atrophy of the unweighted hindlimb muscle.

A case of cerebellar infarction occurred with the 8th cranial nerve symptoms

A rare case, 32-year-old man, of cerebellar infarction with the occurrence of the 8th cranial nerve symptoms was reported. On the neuro-otological examination, hearing test and caloric test showed a severe hearing loss and no response on the right side, respectively, and the spontaneous horizontal nystagmus fixed to the left direction was observed. Magnetic resonance (MR) imaging showed the infarctions in the areas of anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) on the right side. On the 14th illness day, the 8th cranial nerve symptoms disappeared, and on the 12th illness day, right hearing level and caloric response were significantly improved. We suggested that such an early recovery of the subjective symptoms and neuro-otological findings may be attributable to the recanalized circulation disturbance or the development of collateral circulation.

Human cystathionine beta-synthase cDNA: sequence, alternative splicing and expression in cultured cells

Cystathionine beta-synthase (CBS) deficiency is the major cause of homocystinuria in humans. The most frequent symptoms of homocystinuria include: dislocated optic lenses, vascular disorders, skeletal abnormalities and mental retardation. Patients with this deficiency have elevated levels of homocyst(e)ine, methionine and low cysteine in their body fluids. These abnormal levels often partially or fully normalize upon treatment with pharmacological doses of vitamin B6. To investigate the molecular and biochemical basis for these conditions, it was necessary to determine the nucleotide and polypeptide sequence of CBS. We report here the human CBS cDNA sequence of 2,554 nucleotides encoding the CBS subunit of 551 amino acids. An intron of 214 bp appears to be retained in the 3'-untranslated region of most of the fibroblast and liver mRNA. We also report a frequent Mspl polymorphism in the 3'-untranslated sequence and two synonymous mutations in the coding region: 699C/T (Y233Y) and 1080C/T (A360A). The amino acid sequence similarity of human and rat CBS is greater than 90%; the enzyme also exhibits 52% similarity to O-acetylserine(thiol)-lyase from bacteria and plants. Lastly, we demonstrate that expression of the human enzyme in CHO cells yields enzymatically active protein of the expected size with a half-life of approximately 14 hrs.

Detection of minimal residual disease in Philadelphia chromosome positive acute lymphoblastic leukemia: rationale for bone marrow transplantation from the polymerase chain reaction point of view

Bone marrow transplantation (BMT) is performed as curative therapy for acute lymphoblastic leukemia (ALL). In most patients, BMT is performed at the time of remission which implies that the number of leukemic cells is less than 5% of all hematopoietic cells, namely, 0 to 10(10) leukemia cells in the body. Thus, some patients may well undergo BMT despite the fact that no leukemic cells are left in the body. In this respect, more accurate diagnosis of complete remission status would be to the patients' benefit. To detect minimal residual disease (MRD) not found by light-microscopy, further strategies are required after achieving hematological remission. Cytogenetic methods, Southern blot analysis and conventional immunological techniques can all provide accurate diagnosis, however, the sensitivity of these techniques for the detection of MRD is just as low as that of the light microscopy. Recently, polymerase chain reaction (PCR) has become available for the detection of low levels of chimeric bcr-abl transcripts in Philadelphia chromosome positive (Ph1) ALL patients. With this assay, investigators have reported MRD in patients after chemotherapy or BMT. Most patients who achieve hematological remission after conventional chemotherapy still have bcr-abl transcript detectable by PCR, confirming the general concept that this particular leukemia needs BMT in order to cure the disease. Some patients who had MRD prior to BMT continued disease free survival > 1 year after BMT with a negative PCR result and in these patients, MRD seems to have been eradicated by the BMT procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ontogeny of the pronephros and mesonephros in the South African clawed frog, Xenopus laevis Daudin, with special reference to the appearance and movement of the renin-immunopositive cells]

Development of the pronephros and mesonephros of Xenopus laevis was morphologically studied in the larvae immediately after hatch (stage 35/36) to the end of metamorphosis (stage 66) together with the appearance of renin-immunopositive cells. The pronephros consisted of 3 pairs of pronephric tubules at stage 35/36 and became functional at stage 37/38 with the opening of the pronephric ducts to the cloaca. It increased thereafter in volume, but became degenerative at stage 56, lost a part of the pronephric ducts at stage 60, and completely disappeared at stage 64. The mesonephros displayed its anlage at stage 42, and gained the immature renal corpuscles at stage 48. At stage 49, it was equipped with the matured nephrons. The mesonephric tubules differentiated into the neck, proximal, intermediate and distal parts. The collecting tubules and ducts were also observed at this stage. At stage 56, a part of the mesonephric tubules degenerated and were displaced by newly formed tubules. Reorganization of the mesonephros was not completed at the end of metamorphosis. Renin-immunopositive cells did not appear in the pronephros, but were observed at the diverging part of the renal artery from the dorsal aorta, and in the walls of arteries and afferent arterioles within the mesonephros in a low frequency of appearance.

Unexpected heterogeneity of PML/RAR alpha fused mRNA detected by nested polymerase chain reaction in acute promyelocytic leukemia

We have analyzed ten APL patients using reverse transcription polymerase chain reaction (RT-PCR) technique to detect PML/RAR alpha fused mRNA. All patients in this study had PML/RAR alpha fused mRNA (three cases of the short type and seven cases of the long type), although the chromosomal translocation t(15;17) was not detected in one patient. After ethidium bromide staining, two-thirds of the short type and all cases of the long type were found to have multiple PCR products (192 and 93 base pair (bp) bands in the short type and 666, 522, 263, and 164 bp in the long type). A total of six distinct fused mRNAs were sequenced (P1R1, P1R2, P3R1, P2R1, and P2R2). Southern hybridization analysis showed only one rearranged band in each of the patients. These results suggest that the longest mRNAs in each type are the authentic fused mRNAs and the other smaller mRNAs are generated through splicing events. In RAR alpha, a novel fusion point (R2) was identified within the fourth exon. This uncommon splicing may be caused by the instability of the splicing mechanism of the rearranged PML/RAR alpha gene. Among the ten APL patients, no correlation was observed between the type of fused mRNA and the clinical characteristics examined.

[Motility of isolated vestibular hair cells induced by potassium]

Many studies of the outer hair cells in cochlea have demonstrated active motility. However, very few studies have been done on vestibular hair cells. This study was designed to demonstrate the motile responses of isolated vestibular hair cells of the chick, induced by potassium promoting contraction. Reversible cell shape changes were observed in 4 of 6 type I hair cells and 3 of 5 type II hair cells by applying the contraction solution. The cell shape changes were revealed mainly in the cuticular plate and infracuticular region. It was suggested that contraction in the cuticular plate of the isolated hair cells might be converted into tension which increases the stiffness of the sensory hairs and restricts their motions, based on the results of the present study, and the structure of contractile proteins and hair behaviors reported by previous investigators.

Long persistent bcr-abl positive transcript detected by polymerase chain reaction after marrow transplant for chronic myelogenous leukemia without clinical relapse: a study of 64 patients

We report here the results of polymerase chain reaction (PCR) for bcr-abl transcript and clinical details derived from 64 chronic myelogenous leukemia (CML) patients after allogeneic bone marrow transplantation (BMT). A total of 139 samples (2 to 220 weeks after BMT) were analyzed and bcr-abl transcript was detected in 99 samples from 52 patients. Patients were defined as bcr-abl early negative (EN) if they had > or = 1 negative PCR result < or = 1 year post-BMT (n = 13), and bcr-abl late positive (LP) if they had > or = 1 positive PCR result > or = 1 year post-BMT (n = 21). Among LP patients, only two patients had hematologic/cytogenetic (clinical) relapse. Another 19 LP patients remained in clinical remission 7 to 130 weeks after positive analysis for bcr-abl transcript, including 5 patients who had persistent bcr-abl transcript detectable even 2 years after BMT. To estimate the relationship between clinical data and residual bcr-abl transcript, EN patients are compared with LP patients. However, no clinical data studied were significantly associated with the persistent PCR positivity. If only patients in chronic phase are compared, the t-test showed significant correlation between leukocyte count just before BMT and sustained bcr-abl transcript (P < .05). These results suggest that PCR positivity is frequently observed in CML patients who sustain clinical remission after BMT, without being predictive of imminent clinical relapse. Tumor burden at the time of BMT may play an important role in the latency of bcr-abl positivity after BMT.

[Paranasal sinusitis due to Pasteurella multocida]

A case of paranasal sinusitis due to Pasteurella multocida (P. multocida) is reported. A 39-year-old woman presented with chief complaints of rhinorrhea and headache. The patient kept a cat in her house and kept such close contact with it as to wake up by being licked every morning. Bacteriological examination revealed P. multocida isolated from her nasal discharge and also from the saliva of the cat kept by the patient. The two isolates were compatible with respect to biochemical properties, serotype and drug susceptibility. Therefore, P. multocida infection in this case was considered to have originated from the pet cat. P. multocida infection has been increasing recently. One of the reasons is a pet boom. In order to prevent acquiring the infection from a pet animal, we should have knowledge about this infection, advise the patient to avoid close contact with pets, and provide valuable information concerning these problems to society from the viewpoint of zoonosis.

Three independent mutations in the same exon of the PCCB gene: differences between Caucasian and Japanese propionic acidaemia

Propionic acidaemia is an inborn error of organic acid metabolism caused by deficiency of propionyl-CoA carboxylase (PCC). Enzyme deficiency can result from mutations in either of the non-identical alpha- and beta-subunits. We have screened genomic DNA from patients with defects in the beta-subunit from two ethnic groups (Caucasians and Japanese) and detected three types of mutations in the same exon of the coding sequence of the beta-subunit: an insertion/deletion that replaces 14 nucleotides with 12 nucleotides of unrelated sequence and eliminates an Msp I site; a 3-bp deletion of a single isoleucine codon immediately proximal to that Msp I site; and a C-->T transition in the same Msp I site. The insertion/deletion was detected only in Caucasian patients in 11 of 34 mutant alleles; the C-->T transition was found only in Japanese patients in 4 of 12 mutant alleles. Following digestion of genomic DNA by Msp I, both of these mutations were detected on Southern blots by the presence of a 2.7-kbp band; they can be distinguished from one another by allele-specific oligonucleotide hybridization following PCR amplification. These results underscore the independent origin of the mutations in the two populations and suggest a key role of this exon in the beta-subunit of PCC.