Pharmacokinetics and metabolism of KW-4490, a selective phosphodiesterase 4 inhibitor: difference in excretion of KW-4490 and acylglucuronide metabolites between rats and cynomolgus monkeys.

1. The pharmacokinetics and metabolism of KW-4490, a selective phosphodiesterase 4 inhibitor, were investigated in rats and monkeys. After oral administration, KW-4490 was rapidly absorbed, and then its plasma concentrations apparently declined with half-lives of approximately 5 h in rats and 3.5 h in cynomolgus monkeys; however, a number of secondary peaks were apparent in the profiles for both species. The plasma pharmacokinetics of KW-4490 were comparable between rats and monkeys. 2. After oral administration, KW-4490 was mainly eliminated by metabolism to acylglucuronides and renal excretion in the unchanged form. KW-4490 acylglucuronides were found in monkey but not rat urine. In rats, KW-4490 acylglucuronides were excreted only in bile. Although the pathway of excretion of acylglucuronides differed between rats and monkeys, cumulative excretion in the two animals was very similar, as expected from comparable hepatic clearance for glucuronidation in rat and monkey liver microsomes. 3. The glomerular filtration rate of unbound KW-4490 indicated that renal tubular secretion was significant in monkeys, whereas reabsorption was significant in rats. These species differences in urinary excretion of KW-4490 and its acylglucuronide metabolites are most likely due to substrate specificity of active transporters in rat and monkey kidney.

Effect of the antiulcer polysaccharide fraction from Bupleurum falcatum L. on the healing of gastric ulcer induced by acetic acid in rats.

An antiulcer polysaccharide fraction (BR-2) from Bupleurum falcatum L. was examined for its effect on the healing of chronic ulcers induced by acetic acid in rats. When BR-2 was administered orally to the rats, it was shown to be effective in the healing of acetic acid-induced chronic ulcer. This result suggests that the use of herbal prescriptions containing B. falcatum L. may prove useful for the treatment of peptic ulcers.

Molecular cloning of a cDNA encoding mouse DNA helicase B, which has homology to Escherichia coli RecD protein, and identification of a mutation in the DNA helicase B from tsFT848 temperature-sensitive DNA replication mutant cells.

DNA helicase B is a major DNA helicase in mouse FM3A cells. A temperature-sensitive mutant defective in DNA replication, tsFT848, isolated from FM3A cells, has a heat-labile DNA helicase B. In this study, we purified DNA helicase B from mouse FM3A cells and determined partial amino acid sequences of the purified protein. By using a DNA probe synthesized according to one of the partial amino acid sequences, a cDNA was isolated, which encoded a 121.5 kDa protein containing seven conserved motifs for DNA/RNA helicase superfamily members. A database search revealed similarity between DNA helicase B and the alpha subunit of exodeoxyribonuclease V of a number of prokaryotes including Escherichia coli RecD protein, but no homologous protein was found in yeast. The cDNA encoding DNA helicase B from tsFT848 was sequenced and a mutation was found between DNA/RNA helicase motifs IV and V.

Antitumor activity of tumor necrosis factor-alpha conjugated with polyvinylpyrrolidone on solid tumors in mice.

We attempted the development of a novel polymer conjugation to further improve the therapeutic potency of antitumor cytokines compared with PEGylation for clinical application. Compared with native tumor necrosis factor (TNF)-alpha in vitro, specific bioactivities of polyvinyl-pyrrolidone (PVP)-modified TNF-alphas (PVP-TNF-alphas) were decreased by increasing the degree of PVP attachment. PVP-TNF-alpha fraction 3, Mr 101,000, had the most effective antitumor activity of the various PVP-TNF-alphas in vivo. PVP-TNF-alpha fraction 3 had >200-fold higher antitumor effect than native TNF-alpha, and the antitumor activity of PVP-TNF-alpha fraction 3 was >2-fold higher than that of MPEG-TNF-alpha (Mr 108,000), which had the highest antitumor activity among the polyethylene glycol (PEG)-conjugated TNF-alphas. Additionally, a high dose of native TNF-alpha induced toxic side effects such as body weight reduction, piloerection. and tissue inflammation, whereas no side effects were observed after i.v. administration of PVP-TNF-alpha fraction 3. The plasma half-life of PVP-TNF-alpha fraction 3 (360 min) was about 80- and 3-fold longer than those of native TNF-alpha (4.6 mm) and MPEG-TNF-alpha (122 min), respectively. The mechanism of increased antitumor effect in vivo caused the prolongation of plasma half-life and increase in stability. These results suggested that PVP is a useful polymeric modifier for bioconjugation of TNF-alpha to increase its antitumor potency, and multifunctionally bioconjugated TNF-alpha may be a potentiated antitumor agent for clinical use.

Reaction of various lectins to mucin derived from the different layers of rat gastric mucosa: comparison of enzyme-linked lectin binding assay with lectin histochemistry.

The purpose of this study was to demonstrate that the histochemical staining reactivities of lectins in rat stomach actually represent the gastric mucins, and to estimate the utility of the lectins for mucin histochemistry. In this paper, the lectin histochemistry was compared with an enzyme-linked lectin binding assay (ELLA) of the mucins derived from distinct regions and layers of the Sprague-Dawley rat stomach and it was examined to determine the definite binding and problematic binding of the conventional lectin. Among the 10 different biotinylated lectins, Canavalia ensiformis (ConA), Griffonia simplicifolia II (GS-II), Triticuin vulgaris (WGA), Ricinus communis I (RCA-I), Arachis hypogaea (PNA), Glycine max (SBA), Dolichos biflorus (DBA), Ulex europaeus I (UEA-I), Sambucus nigra (SNA) and Maackia amurensis II (MAL-II), examined in this study, GS-II, SBA, DBA, UEA-I, SNA and MAL-II bound clearly to the mucin of distinct regions and layers of the Sprague-Dawley rat stomach in agreement with the results of ELLA. Namely GS-II lectins preferentially bound to the mucin in the mucous neck cells of the corpus area. SBA and DBA clearly recognized the mucin in the covering epithelial mucous cells in the corpus and antral area. UEA-I was widely bound to all the mucin present in both the corpus and antrum. On the other hand, SNA and MAL-II could not react with the mucin obtained from the gastric mucosa but was specifically bound to the mucin purified from the mucous gel layer. These results suggested that the lectins described above are useful histochemical tools to recognize the mucus present in the different regions and layers of Sprague-Dawley rat gastric mucosa.

Rat gastric mucous gel layer contains sialomucin not produced by the stomach.

The sialylated mucus components of the normal gastric mucosa and mucous gel layer of rats were studied by using various histochemical staining methods including Maackia amurensis II (MAL-II) and Sambucus nigra (SNA) lectins, alcian blue (AB) pH 2.5 -- periodic acid Schiff (PAS) and high iron diamine (HID) -- AB pH 2.5. The acidic and neutral mucins characterized by the AB-PAS staining were abundantly present in the mucous gel layer as well as in the gastric mucosa. The sialomucin characterized by HID-AB was barely found in either the mucous gel layer or the mucosa. The sialomucin positive to MAL-II and SNA, which react with the N-acetyl neuraminic acid residue linked to galactose via an alpha-linkage, was moderately detected only in the mucous gel layer, but not in the entire mucosal layer. Furthermore, in animals given surgery to form an esophageal fistula through which saliva was excluded or in animals subjected to salivectomy, the mucous gel layer stained with MAL-II and SNA lectins was markedly decreased. These results indicate that a part of the sialomucin containing-mucous gel layer covering normal rat gastric mucosa originates from the saliva and that MAL-II and SNA lectins are useful for detecting this specific sialomucin.

Bioconjugation of laminin-related peptide YIGSR with polyvinyl pyrrolidone increases its antimetastatic effect due to a longer plasma half-life.

Polyvinyl pyrrolidone (PVP) which can be radically synthesized and have a long blood residency was used to modify the laminin-related peptide YIGSR, and its inhibitory effect on experimental lung metastasis of B16-BL6 melanoma cells was examined. The antimetastatic effect of PVP-conjugated YIGSR (PVP-YIGSR) was more than 100-fold greater than that of native YIGSR. When injected intravenously, PVP-YIGSR showed more than a 15-fold longer plasma half-life relative to native YIGSR. In addition, the stability of YIGSR in plasma was increased by conjugation with PVP. These findings suggest that PVP is a useful polymeric modifier for increasing the antimetastatic activity of YIGSR.

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.

Bioconjugation of laminin peptide YIGSR with poly(styrene co-maleic acid) increases its antimetastatic effect on lung metastasis of B16-BL6 melanoma cells.

A comb-shaped polymeric modifier, SMA [poly(styrene comaleic anhydride)], which binds to plasma albumin in blood was used to modify the synthetic cell-adhesive laminin peptide YIGSR, and its inhibitory effect on experimental lung metastasis of B16-BL6 melanoma cells was examined. YIGSR was chemically conjugated with SMA via formation of an amide bond between the N-terminal amino group of YIGSR and the carboxyl anhydride of SMA. The antimetastatic effect of SMA-conjugated YIGSR was approximately 50-fold greater than that of native YIGSR. When injected intravenously, SMA-YIGSR showed a 10-fold longer plasma half-life than native YIGSR in vivo. In addition, SMA-YIGSR had the same binding affinity to plasma albumin as SMA, while native YIGSR did not bind to albumin. These findings suggested that the enhanced antimetastatic effect of SMA-YIGSR may be due to its prolonged plasma half-life by binding to plasma albumin, and that bioconjugation of in vivo unstable peptides with SMA may facilitate their therapeutic use.

A Case of Phyllodes Tumor with Bloody Nipple Discharge in Juvenile Patient.

We report a rare case of phyllodes tumor of the breast in a juvenile patient with bloody nipple discharge. An 11-year-old girl had a chief complaint of a palpable 5 cm well-circumscribed tumor with nipple discharge in the left breast. The histopathological diagnosis of the resected specimen was benign phyllodes tumor showing extensive areas of hemorrhagic necrosis. The bloody nipple discharge was caused by spontaneous infarction of the tumor. Preoperative ultrasonography and galactography were helpful in evaluating the mechanism of nipple dicharge from the tumor. Although phyllodes tumor must be differentiated from fibroadenoma, the present case was histopathologically identical to phyllodes tumor.

Low prevalence of a polymorphism of platelet membrane glycoprotein Ib beta associated with neonatal alloimmune thrombocytopenic purpura in Asian populations.

Iy alloantigen system is the first polymorphism of platelet glycoprotein Ib beta reported to cause neonatal alloimmune thrombocytopenic purpura. We investigated the allelic frequency of Iy alloantigen among Japanese and Korean populations by polymerase chain reaction-restriction fragment length method to determine the possibility of alloimmunization against Iy. Two hundred and nine Japanese and 97 Korean subjects were examined. All 306 individuals were homozygous for glycine at amino acid position 15 and negative for Iy. The allelic frequency of Iy in these populations was calculated to be less than 0.0016. Alloimmunization associated with Iy antigen in Asian populations seems unlikely from these results.

A selective amplifier gene for tamoxifen-inducible expansion of hematopoietic cells.

BACKGROUND: We have developed a novel system for expansion of gene-modified hematopoietic stem/progenitor cells to overcome the low efficiency of current gene transfer methodology. This system involves 'selective amplifier genes', that encode fusion proteins between the granulocyte colony-stimulating factor receptor (GCR) and the hormone-binding domain of estrogen receptor (ER). Hematopoietic progenitors expressing the chimeras showed estrogen-responsive growth in a controllable manner. However, endogenous estrogen may activate the fusion proteins in vivo, depending on the hormonal status of the subjects. METHODS: We replaced ER with a mutant receptor (TmR) which specifically binds to 4-hydroxytamoxifen (Tm), to overcome limitations with wild-type ER. Interleukin-3 (IL-3)-dependent Ba/F3 cells and hematopoietic progenitor cells transduced with the resultant fusion proteins (GCRTmR and delta GCRTmR) were examined for ligand-inducible growth. RESULTS: GCRTmR- and delta GCRTmR-expressing Ba/F3 showed IL-3-independent growth in response to Tm, while the cells were unresponsive to estrogen at concentrations up to 10(-7)-10(-6) M. Furthermore, murine bone marrow cells transduced with GCRTmR and delta GCRTmR formed colonies in methyl-cellulose medium in response to Tm, while virtually no colonies appeared with 10(-7) M estrogen or without cytokines. CONCLUSIONS: These results suggest that influences of the endogenous estrogen can be almost eliminated by using the GCRTmR/Tm or delta GCRTmR/Tm system to expand gene-modified hematopoietic stem/progenitor cells.

Fas and mutant estrogen receptor chimeric gene: a novel suicide vector for tamoxifen-inducible apoptosis.

Several cancer gene therapy strategies involve suicide genes to kill the neoplasm, or to regulate effector cells such as lymphocytes. We have developed an inducible apoptosis system with a Fas-estrogen receptor fusion protein (MfasER) for rapid elimination of transduced cells. In the present study, we further improved this molecular switch for estrogen-inducible apoptosis to overcome concerns with the wild-type estrogen receptor and its natural ligand, 17beta-estradiol (E2). The ligand-binding domain of MfasER was replaced with that of a mutant estrogen receptor which is unable to bind estrogen yet retains affinity for a synthetic ligand, 4-hydroxytamoxifen (Tm). The resultant fusion protein (MfasTmR) and MfasER were expressed in L929 cells for examination of their ligand specificities. Tm induced apoptosis in MfasTmR-expressing cells (L929MfasTmR) at 10(-8) M or higher concentrations, but induced no apoptosis in MfasER-expressing cells (L929MfasER) at up to 10(-6) M. On the other hand, E2 induced apoptosis in L929MfasER at concentrations as low as 10(-10)-10(-9) M, while it did so partially in L929MfasTmR at concentrations greater than 10(-7) M. Thus, L929MfasTmR cells were highly susceptible to Tm, but refractory to E2, with 100-1,000 times more tolerance than L929MfasER. These results suggest that the MfasTmR/Tm system would induce apoptosis in the target cells more safely in vivo, working independently of endogenous estrogen.

Resistance to activated protein C and Arg 506 Gln factor V mutation are uncommon in eastern Asian populations.

We investigated the prevalence of the factor V (FV) Arg 506 Gln mutation in healthy subjects from three eastern Asian countries (Japan, n = 270; China, n = 113; and Korea, n = 93) and in 26 Japanese patients showing venous thromboembolic events. The patients were also examined for activated protein C (APC) resistance by using the Coatest APC resistance kit. The FV mutation was investigated by polymerase chain reaction and restricted enzyme digestion with MnlI RFLP assay of the FV gene. None of the patients showed APC resistance, while all subjects examined were homozygous for Arg at position 506 of the FV gene. Our results imply that FV mutation and APC resistance contribute little to venous thrombotic diseases in eastern Asia.

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.

The largest isoform of platelet membrane glycoprotein Ib alpha is commonly distributed in eastern Asian populations.

Platelet membrane glycoprotein Ib alpha has at least two polymorphisms which affect phenotype. One is the dimorphism at codon 145, and the other is a molecular weight polymorphism due to variable numbers of tandem repeats (TR) in the macroglycopeptide region. These two polymorphisms are in linkage disequilibrium. The frequencies of these polymorphisms differ considerably depending on race, and the largest variant with four TR is almost exclusively present in the Japanese population. We examined the genotypes of HPA-2 and TR polymorphism in three different races from Eastern Asia; the Japanese (n = 103), Korean (n = 101) and Chinese population (n = 177). The gene frequency of HPA-2 differed significantly among these three populations. Among HPA-2b-positive individuals, the A isoform with four TR and B with three TR were present in all three populations and A dominated over B. Individuals homozygous for the A isoform were found in both Japanese and Korean populations. These findings indicate that the largest haplotype is common in the Eastern Asian region.

Eosinophilia associated with proliferation of CD(3+)4-(8-) alpha beta+ T cells with chromosome 16 anomalies.

We describe a patient with eosinophilia and an abnormal CD(3+)4-(8-) alpha beta+ T-cell population. Chromosomal analysis of sorted CD(3+)4-(8-) cells revealed abnormal karyotypes on chromosome 16. In the presence of IL-2 the production of IL-5 from CD(3+)4-(8-) cells was higher than that from CD(3+)4-(8-) cells. Eosinophil survival-enhancing activity in the patient serum was inhibited by a combination of anti-IL-5 and anti-GM-CSF monoclonal antibodies. These data suggest that increased production of IL-5 and GM-CSF from the abnormal CD(3+)4-(8-) cells might cause eosinophilia.

[Effect of FRG-8813, a new histamine H2-receptor antagonist, on gastric mucus production in rats].

We examined the effect of FRG-8813, a new histamine H2-receptor antagonist, on 1% NH3-induced gastric mucosal lesions and basal gastric mucus production in rats. The effect of FRG-8813 (10 mg/kg) given orally was investigated macroscopically and histochemically compared with that of 16,16-dimethyl prostaglandin E2 (dmPGE2, 2 micrograms/kg) or capsaicin (Cap, 10 mg/kg) in the fundic gland area. FRG-8813, dmPGE2 and capsaicin inhibited the NH3-induced mucosal lesions, and stimulated the mucus secretion 5 min after the administration. Chemical deafferentation abolished the gastroprotective effect of FRG-8813 or Cap and attenuated the increase by FRG-8813, dmPGE2 or Cap in mucus secretion seen after 5 min. These results suggest that FRG-8813 exerts its effect on gastric mucus production partially through the capsaicin-sensitive afferent nerves, like the mechanism involved in gastroprotection, and that the increase in mucus production by FRG-8813 is at least in part responsible for the gastroprotection.

[Effects of FRG-8813, a new histamine H2-receptor antagonist, on gastric mucus in rats].

We examined the effects of FRG-8813, a new histamine H2-receptor antagonist with potent antisecretory activity, on gastric mucus in male SD rats (7w). In this study, the effects of FRG-8813 (1, 3, 10 mg/kg), given orally twice a day for 7 days, were investigated by histochemical and biochemical methods in comparison with those of cimetidine (CM, 30 mg/kg) and famotidine (FM, 1 mg/kg) in the fundic gland area (F. area) and pyloric gland area (P. area). In the histochemical study by alcian blue (pH 2.5)-PAS (AB-PAS) or high iron diamine-alcian blue (HID-AB) staining, the CM group showed a significant decrease in PAS and tended to show decreases in HID-AB positive mucus and mucous gel layer in the F. area; the FM group also showed a decrease in AB positive mucus in the P. area. On the other hand, the AB-PAS and HID-AB positive mucus of the FRG-8813 group were not affected. In the biochemical study, FRG-8813 increased the gastric mucosal hexose, hexosamine and sialic acid composing the mucus in a dose-dependent manner in the F. area. These results suggest that FRG-8813 does not cause a decrease in gastric mucus, unlike CM or FM, and it may be able to promote mucus secretion through increasing the mucous component in the F. area.