Sorafenib plus hepatic arterial infusion chemotherapy with cisplatin versus sorafenib for advanced hepatocellular carcinoma: randomized phase II trial

In a randomized phase II study of sorafenib plus hepatic arterial infusion chemotherapy with cisplatin in comparison with sorafenib alone in patients with advanced hepatocellular carcinoma, it yielded favorable overall survival when compared with sorafenib alone. This is the first report of its effectiveness in relation to the overall survival in comparison with that of sorafenib alone in patients with advanced hepatocellular carcinoma.

Background

Sorafenib (Sor) is acknowledged as a standard therapy for advanced hepatocellular carcinoma (HCC). This trial was conducted to evaluate the effect of addition of hepatic arterial infusion chemotherapy with cisplatin (SorCDDP) to Sor for the treatment of advanced HCC.

Patients and methods

We conducted a multicenter open-labeled randomized phase II trial in chemo-naïve patients with advanced HCC with Child-Pugh scores of 5–7. Eligible patients were randomly assigned 2:1 to receive SorCDDP (sorafenib: 400 mg bid; cisplatin: 65 mg/m², day 1, every 4–6 weeks) or Sor (400 mg bid). The primary end point was overall survival.

Results

A total of 108 patients were randomized (Sor, n = 42; SorCDDP, n = 66). The median survival in the Sor and SorCDDP arms were 8.7 and 10.6 months, respectively [stratified hazard ratio (95% confidence interval), 0.60 (0.38–0.96), P = 0.031]. The median time to progression and the response rate were, respectively, 2.8 months and 7.3% in the Sor arm and 3.1 months and 21.7% in the SorCDDP arm. The adverse events were more frequent in the SorCDDP arm than in the Sor arm, but well-tolerated.

Conclusion

SorCDDP yielded favorable overall survival when compared with Sor in patients with advanced HCC.

Clinical Trial registration

UMIN-CTR (http://www.umin.ac.jp/ctr/index-j.htm), identification number: UMIN000005703.

Purification and Some Properties of Acidocin 8912, a Novel Bacteriocin Produced byLactobacillus acidophilusTK8912

Acidocin 8912, a bacteriocin produced by Lactobacillus acidophilus TK8912, was purified by ammonium sulfate fractionation and successive chromatographies on CM-cellulose, Sephadex G-50, Sephadex G-25, and reversed-phase HPLC on Aquapore RP-300. The purified acidocin 8912 migrated as a single band on SDS-PAGE. The molecular weight was estimated to be 5200 by SDS-PAGE, and 5400 by HPLC gel filtration on TSKgel G3000PWXL. Both the amino acid composition and the N-terminal amino acid sequence analysis indicated that acidocin 8912 was a peptide composed of presumably 50 amino acids containing a Lys residue at the N-terminus. The purified acidocin 8912 showed a bactericidal effect on sensitive cells but not a bacteriolytic effect.

Evaluation of nanodispersion of iron oxides using various polymers

In order to create Fe2O3 and Fe2O3·H2O nanoparticles, various polymers were used as dispersing agents, and the resulting effects on the dispersibility and nanoparticulation of the iron oxides were evaluated. It was revealed that not only the solution viscosity but also the molecular length of the polymers and the surface tension of the particles affected the dispersibility of Fe2O3 and Fe2O3·H2O particles. Using the dispersing agents 7.5% hydroxypropylcellulose-SSL, 6.0% Pharmacoat 603, 5.0% and 6.5% Pharmacoat 904 and 7.0% Metolose SM-4, Fe2O3 nanoparticles were successfully fabricated by wet milling using Ultra Apex Mill. Fe2O3·H2O nanoparticles could also be produced using 5.0% hydroxypropylcellulose-SSL and 4.0 and 7.0% Pharmacoat 904. The index for dispersibility developed in this study appears to be an effective indicator of success in fabricating nanoparticles of iron oxides by wet milling using Ultra Apex Mill.

Thrombopoietin stimulates proliferation and megakaryocytic differentiation of mouse pro-B cell line BF-TE22

We have isolated and characterized a thrombopoietin (TPO)-dependent BF-TE22 cell line endogenously expressing murine Mpl, which is a subclone of murine pro-B Ba/F3 cells. TPO stimulated the proliferation of BF-TE22 cells in a dose-dependent manner, and also induced the expression of megakaryocyte lineage-specific AP-51 and CD61 cell surface antigens. The results indicate that the murine Mpl on BF-TE22 cells can transmit both proliferation and megakaryocyte lineage-specific differentiation signals to cells. Furthermore, it was shown that IL-3 inhibits the TPO-induced differentiation signals of BF-TE22 cells. These results suggest that the signals mediated by IL-3 predominate over those of TPO in BF-TE22 cells. Thus, BF-TE22 cells will be useful for the biological and biochemical studies of the TPO-Mpl signal transduction mechanism.

Characterization of human-type monoclonal antibodies against reduced form of hemin binding protein 35 from Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

The gram-negative anaerobe Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. We previously identified a 35 kDa surface protein (hemin binding protein 35; HBP35) from P. gingivalis that exhibited coaggregation activity, while additional analysis suggested that this protein possessed an ability to bind heme molecules. For development of passive immunotherapy for periodontal diseases, human-type monoclonal antibodies have been prepared using HBP35 as an antigen in TransChromo mice. In the present study, we focused on a single antibody, TCmAb-h13, which is known to inhibit heme binding to recombinant HBP35. The aim of our investigation was to clarify the redox-related function of HBP35 and consider the benefits of human-type monoclonal antibodies.

MATERIAL AND METHODS

To examine the antigen recognition capability of TCmAbs with immunoblotting and Biacore techniques, we used the native form as well as several Cys-to-Ser variants of recombinant HBP35.

RESULTS

We found that the redox state of recombinant HBP35 was dependent on two Cys residues, (48) C and (51) C, in the thioredoxin active center (WCGxCx). Furthermore, TCmAb-h13 recognized the reduced forms of recombinant HBP35, indicating its inhibitory effect on P. gingivalis growth.

CONCLUSION

Hemin binding protein 35 appears to be an important molecule involved in recognition of the redox state of environmental conditions. In addition, TCmAb-h13 had an inhibitory effect on heme binding to recombinant HBP35, thereby interfering with P. gingivalis growth.

Magnetic resonance imaging findings of ovarian stromal hyperthecosis

Ovarian stromal hyperthecosis is characterized by diffuse distribution of luteinized stromal cells accompanied by varying degrees of stromal hyperplasia. We report a case of ovarian stromal hyperthecosis with particular regard to magnetic resonance (MR)-pathologic correlation. At initial MR imaging, the central areas of the bilateral ovarian masses showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images, while the peripheries of the bilateral masses showed isointensity to myometrium on T1-weighted images and heterogeneous signal intensities on T2-weighted images. At 15 days after the initial MR imaging examination, a second MR imaging demonstrated shrinkage of the bilateral ovarian masses. Change in the peripheries to predominantly isointensity to myometrium on the T2-weighted images was also observed. The patient underwent bilateral oophorectomy. Microscopic examination revealed scattered nests of lutein cells on a background of densely proliferated ovarian stroma with minimal collagen production in both ovaries. Edema was occasionally seen in the outer portion but was marked in the central zone of the ovaries, particularly on the left. The final pathologic diagnosis was stromal hyperthecosis. With regard to MR-pathologic correlation, the MR findings in the peripheries of the bilateral masses (isointensity relative to myometrium on both T1- and T2-weighted imaging) showed the characteristics of stromal hyperthecosis.

Human normal hepatocytes are susceptible to apoptosis signal mediated by both TRAIL-R1 and TRAIL-R2

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in tumor cells without toxicity to normal cells, but some recombinant versions of TRAIL caused hepatocyte death. We generated fully human monoclonal antibodies (mAbs) that bind specifically to TRAIL receptor 1 (TRAIL-R1) and TRAIL receptor 2 (TRAIL-R2), which mediate apoptosis signal when they ligate with TRAIL, to investigate the contribution of each receptor to induce tumor cell apoptosis and hepatocyte toxicity. All of mAbs to TRAIL-R1 and TRAIL-R2 induced cell death in several cancer cell lines susceptible to TRAIL but not in human umbilical vein endothelial cells in vitro. Both anti-TRAIL-R1 mAbs and anti-TRAIL-R2mAbs also caused cell death in hepatocytes. However, a subset of mAbs to TRAIL-R2, which was characterized by the TRAIL blocking activity, did not show strong hepatocyte toxicity. These results indicate that human normal hepatocytes are susceptible to both TRAIL-R1- and TRAIL-R2-mediated apoptosis signal. Cell Death and Differentiation (2004) 11, 203-207. doi:10.1038/sj.cdd.4401331 Published online 24 October 2003

Role of the microenvironment of the embryonic aorta-gonad-mesonephros region in hematopoiesis

Although various cytokines, growth factors, and chemokines are known to regulate hematopoiesis, expansion of hematopoietic stem cells (HSCs) in vitro with the use of such agents has proved problematic. Stromal cells are major components of the microenvironment that surrounds hematopoietic cells and are thought to play an important role in hematopoiesis in vivo. Co-culture of HSCs with stromal cells promotes hematopoiesis and self-renewal of HSCs. Definitive hematopoietic cells first appear during mammalian embryonic development in the aorta-gonad-mesonephros (AGM) region, and it is therefore thought that the microenvironment of this region plays an important role in HSC ontogeny. We have adopted two approaches to studying the contribution of the AGM microenvironment to hematopoiesis. In the first approach, we have developed an in vitro culture system for mouse AGM explants. Hematopoiesis is enhanced in such cultures by the presence of the combination of stem cell factor (SCF), basic fibroblast growth factor, leukemia inhibitory factor, and oncostatin M (SFLO culture). However, transplantation assays revealed that HSCs capable of long-term reconstitution of the hematopoietic compartment of irradiated mice (LTR-HSCs) do not expand in AGM-SFLO cultures; rather, these cultures appear to provide a favorable microenvironment for hematogenic angioblasts that are precursors of both endothelial and hematopoietic cells. In our second approach, we have established various stromal cell lines from the mouse AGM region. The AGM-S3 cell line supports human and mouse primitive hematopoietic cells as well as mouse LTR-HSCs. Maintenance of LTR-HSCs is mediated by a mechanism other than SCF signaling through its receptor (c-Kit). These two in vitro approaches should prove useful for further elucidation of the mechanisms that underlie hematopoiesis and HSC self-renewal.

Native thrombopoietin: structure and function

Thrombopoietin (TPO), the c-Mpl ligand, is produced constitutively in liver and other organs, circulates in the bloodstream, and is delivered to bone marrow, where it stimulates the early development of multiple hematopoietic lineages and megakaryocytopoiesis. The concentration of TPO in blood is regulated by c-Mpl mass on platelets and megakaryocytes. In addition to regulation by the number of TPO molecules, including the possible modulation of TPO mRNA abundance in bone marrow, megakaryocytopoiesis and platelet production may be regulated as a result of modulation of TPO activity by proteolytic processing that generates truncated forms of the molecule. Characterization of TPO partially purified from human plasma, however, revealed that the full-length molecule was the predominant form in the blood of both normal individuals and thrombocytopenic patients, although small amounts of truncated species were detected. Thus, truncation of TPO, at least that in the circulation examined, does not appear to contribute to the direct regulation of platelet production in response to increased demand. Given that native TPO isolated from the plasma of thrombocytopenic animals comprises truncated forms, the truncation of TPO is likely of physiological importance in the life history of this molecule.

Molecular cloning of delta-4, a new mouse and human Notch ligand

Complementary DNAs encoding a previously unidentified mouse Notch ligand and its human ortholog were isolated. The new Notch ligand contains a signal sequence, a DSL domain, eight epidermal growth factor-like repeats, a transmembrane domain, and an intracellular region, all of which are characteristics of members of the Delta protein family. The new protein was therefore designated Delta-4. Several previously unidentified sequences in both the extracellular and intracellular regions were shown to be conserved among vertebrate Delta proteins. The tissue distribution of Delta-4 mRNA resembles that previously described for Notch-4 (Int-3) transcripts. However, in situ hybridization with mouse lung revealed that Delta-4 mRNA is abundant in squamous alveolar cells that neighbor endothelial cells; Notch-4 expression is largely restricted to the latter cell type. Soluble forms of the extracellular portion of Delta-4 inhibit the apparent proliferation of human aortic endothelial cells, but not human pulmonary arterial endothelial cells.

Radiation enteritis: a rare complication of the transverse colon in uterine cancer

Radiation therapy is a powerful method for the control of cancer. The utilization of abdominal or pelvic radiation has been extended, and the incidence of radiation enteritis appears to be increasing. The majority of the induced lesions is in the distal ileum, sigmoid colon, or rectum. Reported here is an unusual case of radiation enteritis which caused a severe sequelae of stricture in the transverse colon as a long-term effect of therapeutic irradiation for uterine cancer, and required a surgical resection.

Functional analysis of the C-terminal region of recombinant human thrombopoietin. C-terminal region of thrombopoietin is a "shuttle" peptide to help secretion

Thrombopoietin (TPO) is a cytokine that primarily stimulates megakaryocytopoiesis and thrombopoiesis. TPO has a unique C-terminal tail peptide of about 160 amino acids that consists mostly of hydrophilic residues and contains six N-linked sugar chains. In order to investigate the biological function of the C-terminal domain, two series of mutations were performed. One is systematic truncation from the C terminus. Another is elimination of N-glycosylation sites in the C-terminal domain by Asn to Gln mutations. After the mutant proteins were expressed by mammalian cells, it was found that the elimination of the N-linked sugar sites did not affect the biological activity, whereas truncation of the C-terminal domain resulted in elevation of in vitro activity up to 4-fold. The C-terminal peptide itself was found to inhibit the in vitro activity. Moreover, both the C-terminal truncation and the elimination of the N-glycosylation sites decreased the secretion level progressively down to (1)/(10) that of wild type, and the amount of the mutant left in the cell increased. The N-glycosylation in the C-terminal region was found to be important for secretion of TPO. Among six N-glycosylation sites in the C-terminal region, two locations, Asn-213 and Asn-234, were found to be critical for secretion, and two other locations, Asn-319 and Asn-327, did not affect the secretion.

Strong inverse correlation between serum TPO level and platelet count in essential thrombocythemia

Serum thrombopoietin (TPO) levels in 50 essential thrombocythemia (ET) patients were measured using a highly sensitive sandwich ELISA. In nine cases, TPO levels were measured at two points with different platelet counts. ET patients showed significantly higher serum TPO levels (n = 59, 2.70 +/- 2.74 fmol/mL, P < 0.0001) than those of normal individuals (n = 29, 0.83 +/- 0.36 fmol/mL). Twenty-three previously untreated ET patients also showed significantly higher serum TPO levels (1.33 +/- 0.75 fmol/mL, P = 0.0066) than normal individuals. Extremely high serum TPO levels (5.46 +/- 3.68 fmol/mL) were observed in ET patients with normal platelet counts. Furthermore, a strong inverse correlation was found between serum TPO levels and platelet counts in ET patients (R = -0.729, P < 0. 0001). This inverse correlation also held for each of nine cases with two-point TPO measurements. In the clinical course of ET, megakaryocyte mass may parallel the platelet mass before and after chemotherapy. Although it is unknown whether overproduction of TPO exists or not in ET, total platelet and megakaryocyte mass, i.e., the total number of c-Mpl, may play a role to regulate serum TPO levels.

Strong inverse correlation between serum TPO level and platelet count in essential thrombocythemia

Serum thrombopoietin (TPO) levels in 50 essential thrombocythemia (ET) patients were measured using a highly sensitive sandwich ELISA. In nine cases, TPO levels were measured at two points with different platelet counts. ET patients showed significantly higher serum TPO levels (n = 59, 2.70 +/- 2.74 fmol/mL, P < 0.0001) than those of normal individuals (n = 29, 0.83 +/- 0.36 fmol/mL). Twenty-three previously untreated ET patients also showed significantly higher serum TPO levels (1.33 +/- 0.75 fmol/mL, P = 0.0066) than normal individuals. Extremely high serum TPO levels (5.46 +/- 3.68 fmol/mL) were observed in ET patients with normal platelet counts. Furthermore, a strong inverse correlation was found between serum TPO levels and platelet counts in ET patients (R = -0.729, P < 0. 0001). This inverse correlation also held for each of nine cases with two-point TPO measurements. In the clinical course of ET, megakaryocyte mass may parallel the platelet mass before and after chemotherapy. Although it is unknown whether overproduction of TPO exists or not in ET, total platelet and megakaryocyte mass, i.e., the total number of c-Mpl, may play a role to regulate serum TPO levels.

A case of aortic dissection with transient ST-segment elevation due to functional left main coronary artery obstruction

A 48-year-old man with a history of hypertension and diabetes mellitus was hospitalized with sudden onset of severe chest pain. He was in cardiogenic shock with a systolic pressure of 60 mm Hg. His electrocardiogram (ECG) showed ST-segment elevation in the precordial leads suggestive of acute anteroseptal myocardial infarction. The ST-segment returned to baseline after the systolic blood pressure rose to 100 mm Hg with the administration of sympathomimetic agents. Aortography and transesophageal echocardiography demonstrated type A aortic dissection and aortic regurgitation. Aortography and short-axis transesophageal echocardiography showed during diastole almost complete collapse of the true lumen of the ascending aorta caused by the intimal flap. The patient underwent surgical repair of the aortic dissection and implantation of Palmaz stents in the carotid arteries. Decreased blood pressure and the presence of aortic regurgitation accelerated the collapse of the true lumen during diastole in the ascending aorta, resulting in functional obstruction of the left main coronary artery, which may have been related to ST-segment changes in this case.

Aneurysmal bone cyst of the coronoid process of the mandible

A rare case of an aneurysmal bone cyst (ABC) involving the right coronoid process of the mandible in a 12-year-old girl is presented. The characteristic features with fluid-fluid levels within the lesion observed on Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) was helpful in the preoperative diagnosis.

Characterization of native human thrombopoietin in the blood of normal individuals and of patients with haematologic disorders

Thrombopoietin (TPO) isolated from thrombocytopenic plasma of various animal species has previously been shown to comprise only truncated forms of the molecule, presumably generated by proteolysis. Native TPO has now been partially purified from normal human plasma by immunoaffinity chromatography and was confirmed to be biologically active. Gel filtration in the presence of SDS revealed that TPO eluted in two peaks: a major peak corresponding to the elution position of fully glycosylated recombinant human TPO (rhTPO) consisting of 332 amino acid residues, and a minor peak corresponding to a smaller molecular size. Immunoblot analysis also revealed that most plasma-derived TPO migrated at the same position as fully glycosylated rhTPO, corresponding to a molecular size of approximately 80 to 100 kDa. Furthermore, the size distribution of circulating TPO in patients with various haematologic disorders did not differ markedly from that of plasma-derived TPO from healthy individuals. These results indicate that the truncation of circulating TPO is not related to disease pathophysiology, and that the predominant form of TPO in blood is a biologically active approximately 80- to 100-kDa species. The size distribution of TPO extracted from normal platelets was similar to that of TPO in plasma; the proportion of truncated TPO was decreased by prior incubation of platelets with hirudin. indicating that the endogenous truncated TPO, at least in platelet extract, was generated by thrombin-mediated cleavage.

Liver cirrhosis with marked thrombocytopenia and highly elevated serum thrombopoietin levels

Three patients with liver cirrhosis (LC) and a bleeding tendency due to marked thrombocytopenia of less than 20 x 10(9)/l were admitted to our hospital for further examination. Bone marrow examination revealed megakaryocytic hypoplasia in all three patients. All patients exhibited amegakaryocytic thrombocytopenic purpura, myelodysplastic syndrome, or bone marrow hypoplasia. 111In-labeled platelet kinetic studies revealed decreased platelet production in all patients. Although serum thrombopoietin (sTPO) levels are usually within the normal level in patients with LC, the sTPO levels of our patients were about 10 times higher than the levels of normal subjects (1.22 +/- 0.37 fmol/ml): 13.34, 16.79, and 10.46 fmol/ml, respectively. These sTPO data supported our findings of decreased megakaryopoiesis. Our findings suggest that examination of sTPO levels is useful in determining the etiology of marked thrombocytopenia in LC patients.

Serum thrombopoietin and erythropoietin levels in patients with acute promyelocytic leukaemia during all-trans retinoic acid treatment

Endogenous serum thrombopoietin (TPO) and various cytokines including erythropoietin (EPO), interleukin (IL)-3, IL-6, IL-11, granulocyte-colony stimulating factor (G-CSF), granulocyte-macrophage-colony stimulating factor (GM-CSF) and stem cell factor (SCF) levels were measured in five patients with acute promyelocytic leukaemia (APL) during all-trans retinoic acid (RA) treatment. During differentiation-inducing therapy, platelet counts slowly increased and reached a peak between days 29 and 46 (median day 35). Serum TPO levels increased parallel to the increasing platelet counts and reached a maximum level during the first 10-20 d of all-trans RA treatment. The circulating TPO levels then decreased in inverse correlation to the platelet counts. These unique changes in serum TPO levels revealed that TPO levels were not regulated by platelet or megakaryocyte mass in patients with APL during differentiation-inducing therapy, and it would appear that TPO levels are directly regulated by all-trans RA during the first 10-20 d of treatment. In addition, the change in circulating EPO levels and reticulocyte counts were similar to that of the TPO levels and platelet counts during all-trans RA treatment, suggesting a close relationship between TPO and EPO signalling.

Laparoscopically assisted bowel resection for primary mucosa-associated lymphoid tissue lymphoma of the cecum

We present the first report of laparoscopic resection for colorectal mucosa-associated lymphoid tissue (MALT) lymphoma. A 76-year-old man was found to have MALT lymphoma of the cecum during colonoscopy. He underwent a laparoscopically assisted ileocecal resection after admission and was discharged 9 days postoperatively without any complications. Colorectal MALT lymphoma is a rare neoplasm that responds favorably to locally directed therapy, because it tends to remain localized for prolonged periods. Laparoscopic surgery for colorectal MALT lymphoma is considered feasible because it is minimally invasive, making it suitable for treatment of low-grade malignancies, such as MALT lymphoma, which cannot be removed endoscopically.

The dependence of catalytic activities of secondary functional beta-cyclodextrins on cavity structures

Secondary imidazole-appended beta-cyclodextrin 5 with a nondistorted cavity synthesized from a novel intermediate 3-amino-3-deoxy-beta-cyclodextrin exhibits much greater catalytic activity in the ester hydrolysis than its isomer 6 with a distorted cavity, indicating that the catalytic activities of secondary functional cyclodextrins are dependent on cavity structures.

Molecular cloning and functional expression of feline thrombopoietin

Feline thrombopoietin (TPO) was molecularly cloned to establish a basis for cytokine therapy of thrombocytopenia in cats. cDNA clones covering the whole coding sequence of feline TPO were isolated from feline liver. The feline TPO cDNA obtained in this study contained an open reading frame encoding 349 amino acid residues. The predicted amino acid sequence of feline TPO shared 78.7, 69.9, 72.9 and 83.0% similarity with sequences of human, murine, rat and canine TPO, respectively. Four cysteine residues and two of four N-glycosylation sites that are conserved among species were also found at the corresponding positions in feline TPO. The feline TPO cDNA fragment encoding the whole amino acid coding region was recloned into an expression vector, and the resulting vector was transfected into 293T cells using the calcium phosphate method. The supernatant of the transfected 293T cells stimulated the proliferation of a human megakaryoblastic leukemia cell line (UT-7/TPO) cells in a dose dependent manner, indicating that the feline TPO cDNA obtained in this study encodes biologically active feline TPO.

Plasma thrombopoietin (TPO) levels and expression of TPO receptor on platelets in patients with myelodysplastic syndromes

Data on endogenous thrombopoietin (TPO) levels and their regulation in myelodysplastic syndromes (MDS) are sparse. We examined the plasma TPO level of 85 MDS patients by a sensitive enzyme immunoassay and the platelet expression of TPO receptor (TPO-R) protein, which metabolizes endogenous TPO, in 19 MDS patients with an equilibrium binding assay using 125I-TPO. The MDS patients had higher plasma TPO levels (7.0 +/- 9.3 fmol/ml) than 52 normal subjects (P < 0.0001). Refractory anaemia (RA) patients (n = 39) had higher plasma TPO levels than patients (n = 28) with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-t) (P = 0.0002), irrespective of similar platelet counts in these groups. The plasma TPO level correlated inversely with the platelet count in RA patients (P = 0.0027) but not in RAEB and RAEB-t patients (P = 0.7865). These data suggest that the physiological pathway for TPO production and metabolism is conserved, at least partially, in RA, but deranged in RAEB/RAEB-t. The number of TPO-R per platelet was significantly smaller in 19 MDS patients (17.5 +/- 13.3) than in normals (P = 0.0014), but similar between RA patients and patients with RAEB and RAEB-t. Further, the bone marrow megakaryocyte count, determined in 31 MDS patients, was quite similar between RA patients and patients with RAEB or RAEB-t. Thus, in addition to thrombocytopenia, a reduced platelet TPO-R number may contribute to elevated plasma TPO levels in MDS, and a regulatory pathway for circulating TPO other than platelet TPO-R and marrow megakaryocytes, such as blasts expressing TPO-R, may operate in RAEB/RAEB-t.

Changes in serum thrombopoietin levels after splenectomy

To clarify the role of thrombopoietin (c-Mpl ligand, TPO) in 'hypersplenic' thrombocytopenia, we used an enzyme-linked immunosorbent assay to examine changes in serum TPO levels accompanied with splenectomy in 6 patients with liver cirrhosis, 4 patients with gastric cancer, and 2 patients with lymphoid malignancies. We also measured serum levels of other thrombopoietic cytokines such as interleukin-6 (IL-6) and erythropoietin. Platelet counts reached a maximum at day 14 after splenectomy in all subjects. In patients with liver cirrhosis, a lower elevation of platelet counts was observed compared with that in patients with gastric cancer. Serum TPO levels gradually elevated after splenectomy and reached a maximum 3.5 days after splenectomy in noncirrhotic patients, whereas peak serum TPO levels were delayed until day 7 in the cirrhosis group. IL-6 and erythropoietin showed similar kinetics between cirrhotic and noncirrhotic patients. These findings suggest that transient thrombocytosis after splenectomy may be associated with an alteration in the site of TPO catabolism by platelets from spleen to the blood and that deterioration of TPO production may play a role in thrombocytopenia in liver cirrhosis.

Thrombopoietin in patients with hepatoblastoma

Marked thrombocytosis (over 50 x 10(4)/microl) is frequently seen in patients with hepatoblastoma. Thrombopoietin (TPO), c-mpl ligand, has recently been purified as the major physiological regulator of the thrombopoiesis and is mainly produced in the liver. Since it is possible that TPO participates in thrombocytosis and the tumor growth of this particular hepatic tumor, serum TPO levels in addition to interleukin 1beta (IL-1beta) and IL-6 levels were assessed in seven untreated patients by using a sandwich enzyme-linked immunosorbent assay. High serum TPO levels were observed in all of the examined patients. The level ranged from 3.15 to 11.02 (mean +/- standard deviation; 6.08+/-1.25) fmol/ml. IL-6 levels were also somewhat higher than normal. Platelet counts, however, appeared to correlate more with serum TPO levels (p = 0.1) than with IL-1beta (p = 0.5) and IL-6 (p = 0.2) levels. Furthermore, using the reverse transcriptase polymerase chain reaction method, the expression of c-mpl mRNA was found in five of eight hepatoblastoma tissues as well as TPO mRNA in all eight tissues. These observations suggest that thrombocytosis in hepatoblastoma patients results from the production of cytokine members, including TPO, within tumor tissues. Additionally, it is possible that TPO might act as a type of autocrine and/or paracrine system for cellular growth in this tumor.

Native thrombopoietin: structure and function

Thrombopoietin (TPO), the c-Mpl ligand, is produced constitutively in liver and other organs, circulates in the bloodstream, and is delivered to bone marrow, where it stimulates the early development of multiple hematopoietic lineages and megakaryocytopoiesis. The concentration of TPO in blood is regulated by c-Mpl mass on platelets and megakaryocytes. In addition to regulation by the number of TPO molecules, including the possible modulation of TPO mRNA abundance in bone marrow, megakaryocytopoiesis and platelet production may be regulated as a result of modulation of TPO activity by proteolytic processing that generates truncated forms of the molecule. Characterization of TPO partially purified from human plasma, however, revealed that the full-length molecule was the predominant form in the blood of both normal individuals and thrombocytopenic patients, although small amounts of truncated species were detected. Thus, truncation of TPO, at least that in the circulation examined, does not appear to contribute to the direct regulation of platelet production in response to increased demand. Given that native TPO isolated from the plasma of thrombocytopenic animals comprises truncated forms, the truncation of TPO is likely of physiological importance in the life history of this molecule.

Plasma thrombopoietin levels in marrow transplant patients with veno-occlusive disease of the liver

Platelet transfusion requirements are higher among patients with veno-occlusive disease (VOD), compared to patients without VOD. One possible explanation is inadequate production of thrombopoietin (TPO), a protein synthesized in the liver. We prospectively studied 28 patients to test the hypothesis that plasma TPO levels were decreased in patients who developed VOD. Plasma TPO levels to day +30 were measured by ELISA (normal, 0.36+/-0.15 fmol/ml). VOD developed in 18/28 patients. Platelet transfusion requirements were significantly different in patients with and without VOD (97+/-46.1 units vs 51+/-33.2 units, P = 0.008). Plasma TPO levels were elevated at baseline (10.8+/-13.0 fmol/ml) and increased after transplant, with peak values of 32.3+/-10.3 fmol/ml at day +7. TPO levels were significantly higher at days +7 and +17 among patients with VOD than among those without VOD (P < 0.01). Regression analysis of TPO levels vs platelet counts showed a significant inverse relationship. We conclude that TPO levels were higher in patients with VOD and were inversely correlated with platelet counts, suggesting that regulation of TPO levels was related to platelet mass. Thrombocytopenia in patients with VOD cannot be explained by inadequate hepatic synthesis of TPO.

Downgraded non-Hodgkin's lymphoma in the neck occurring as a secondary malignancy

While the histologic progression from low-grade non-Hodgkin's lymphoma (NHL) to intermediate- or high-grade NHL has been well documented, a rare phenomenon called downgrading in which the histologic conversion of a low-grade NHL occurs after treatment for intermediate- or high-grade NHL has recently been recognized. We report the clinical, immunologic, and genetic features of a patient with a diffuse NHL (intermediate grade) who initially achieved complete remission by both chemotherapy and radiation therapy and then presented with a follicular NHL (low grade) 14 years later. The immunohistochemical study of the lymphoma cells showed B lymphocytes in biopsied lymph nodes at both the initial and the second diagnosis. However, a polymerase chain reaction (PCR) analysis for the immunoglobulin gene rearrangement indicated that the clone of the initial intermediate-grade NHL showed monoclonal cell population, and was distinct from that of the second downgraded form. Given the PCR results and the clinical features, we suggest that a follicular NHL can occur as a secondary malignancy following combined therapy for a diffuse NHL.

Thrombopoietin level is inversely related to blast count, not platelet number, in Down syndrome neonates with transient myeloproliferative disorder

Transient myeloproliferative disorder (TMD) in neonates with Down syndrome is characterized by increased megakaryoblastic cells in the peripheral blood. Despite their spontaneous regression in weeks, prognosis is not always favorable because of fatal hepatic fibrosis. In this study, blood thrombopoietin (TPO) levels were measured by ELISA in six TMD patients and the expression of c-Mpl, a ligand for TPO, was examined on the blast cells from four patients by flow cytometer. At the onset, TPO level was undetectable in one patient and significantly lower in five patients than six neonatal controls (mean 0.52 fmol/ml, range 0.30-0.93 vs. 3.70, 1.38-8.33, P < 0.001), although platelet counts were similar (mean 321 x 10(9)/l, range 42-1,040 vs. 253 x 10(9)/l, 124-381). Two patients died of hepatic failure. TPO levels were measured in five patients after regression of the blast cells. With regression of blast cells, TPO levels were remarkably increased in four survived patients. In one patient with hepatic failure, TPO level was poorly elevated and relatively lower compared to the others. TPO levels were inversely correlated with blast numbers (r = -0.85, P < 0.001), but not with platelet counts (r = 0.426). Blast cells from four patients were all positive for c-Mpl. Our findings suggest that megakaryocyte mass is a major regulator of TPO levels and hepatic failure may affect the TPO level because liver is a major source of TPO production.

Evaluation of thrombopoiesis in thrombocytopenic disorders by simultaneous measurement of reticulated platelets of whole blood and serum thrombopoietin concentrations

To evaluate thrombopoiesis in thrombocytopenic disorders, we simultaneously determined reticulated platelet counts in whole blood by FACScan flow cytometry and serum thrombopoietin (TPO) concentrations by a sensitive sandwich ELISA. The subjects were 40 healthy volunteers and 45 thrombocytopenic patients. In idiopathic thrombocytopenic purpura (ITP), the percentage of reticulated platelets was significantly elevated (5.61 +/- 2.02%: mean +/- SD) relative to normal controls (2.17 +/- 0.90%), but serum TPO concentrations (1.91 +/- 1.27 fmol/l) did not differ significantly from the normal range (1.43 +/- 0.62 fmol/l). The patients with aplastic anemia (AA) had decreased reticulated platelet counts and markedly increased serum TPO concentrations (13.65 +/- 10.64 fmol/l). In thrombocytopenic patients with liver cirrhosis (LC), the absolute number of reticulated platelets (1.65 +/- 1.11 x 10(9)/l) decreased similarly that in AA. However, serum TPO concentrations (1.38 +/- 0.50 fmol/l) did not increase in contrast to AA. Our findings suggested a possible dual mechanism of thrombocytopenia in LC; that is, thrombocytopenia in LC results from the decreased TPO production primarily in the liver adding to an increase in platelet sequestration in the spleen.

Increased thrombopoietin levels in idiopathic thrombocytopenic purpura patients with a poor response to steroid therapy

The serum thrombopoietin (TPO) levels in 61 idiopathic thrombocytopenic purpura (ITP) patients were found to be slightly increased compared with those of 29 normal subjects. The TPO levels of the 15 ITP patients who had a poor response to steroid therapy (i.e. an unchanged platelet count) were higher than those of the 22 ITP patients who had a good response to steroid therapy (i.e. an increased platelet count) and the normal subjects. The TPO levels in the 15 ITP patients whose platelet count was higher than 10 x 10(4)/microl after the discontinuation of steroid therapy significantly higher than those of the normal subjects. The platelet-associated immunoglobulin G (PAIgG) levels in the ITP patients who had a poor response to steroid therapy were slightly increased compared with the normal subjects and the ITP patients who had a good response to the steroid therapy and the nine ITP patients who did not undergo the steroid therapy. The serum TPO level was negatively correlated only with the megakaryocyte count in the ITP patients, and the megakaryocyte count in the ITP patients who had good responses to the steroid therapy was higher than that in those who had poor responses. These data suggest that serum TPO levels might be important for the prediction of the outcome of ITP patients who receive steroid therapy.

Serum thrombopoietin level is mainly regulated by megakaryocyte mass rather than platelet mass in human subjects

A patient with idiopathic thrombocytopenic purpura (ITP) developed T-cell lymphoma while undergoing steroid therapy. We examined the relationship between the patient's serum thrombopoietin (Tpo) level, platelet count, megakaryocyte number and CFU-Meg number during the second 5 d course of chemotherapy for lymphoma in which megakaryopoiesis switched from ITP phase to amegakaryocytic phase. The patient's platelet count was temporarily elevated but CFU-Meg numbers were markedly suppressed, and megakaryocyte numbers were decreased in this period, whereas serum Tpo level was not suppressed despite an increased platelet count, indicating that serum Tpo level is mainly regulated by megakaryocyte mass.