Essential hypertension and 5' upstream core promoter region of human angiotensinogen gene

The angiotensinogen (AGT) gene M235T variant is associated with essential hypertension and elevated plasma AGT concentrations, although the underlying mechanisms are unknown. Recent studies have suggested that AGCE 1 (human AGT gene core promoter element 1) located in the 5' upstream core promoter region (position -25 to -1) of the human AGT gene has an important part in the expression of AGT mRNA by binding with transcription factor AGCF 1 (human AGT gene core promoter element binding factor 1), and a mutation at -20 from adenine to cytosine (A-20C) increases the level of expression of this transcript. We therefore examined subjects with this mutation to study the association with increased plasma AGT concentrations and with essential hypertension. One hundred eighty-eight subjects receiving no antihypertensive medication were examined with regard to the correlation between A-20C and plasma AGT concentrations, and 234 subjects were studied with respect to the association between A-20C and essential hypertension. A-20C was determined by polymerase chain reaction-restriction fragment length polymorphism analysis with EcoOR 109I. Multiple regression analysis showed a weak but significant correlation between A-20C and plasma AGT concentrations (P=.047) and essential hypertension (P=.049). The results suggest that A-20C may underlie the increase in plasma AGT concentrations and be involved in the development of essential hypertension.

Inhibition by N-(4-hydroxyphenyl)retinamide and all-trans-retinoic acid of exogenous and endogenous development of putative preneoplastic, glutathione S-transferase placental form-positive lesions in the livers of rats

The effects of N-(4-hydroxyphenyl)retinamide (4-HPR) and all-trans-retinoic acid (tRA) on the exogenous and endogenous models of rat liver carcinogenesis respectively using diethylnitrosamine (DEN) and a choline-deficient, L-amino acid-defined (CDAA) diet were studied. For the exogenous study, male Fischer 344 rats, 6 weeks old, were given a single i.p. dose of 200 mg/kg body wt of DEN, partially hepatectomized at week 3, administered 4-HPR at doses of 0, 0.04, 0.08 and 0.16% or tRA at 0, 0.004, 0.008 and 0.015% in diet from week 2 for 6 weeks, and killed at the end of week 8. For the endogenous study, rats were fed the CDAA diet containing 4-HPR or tRA for 12 weeks and killed at the end of week 12. 4-HPR decreased the numbers and sizes of the glutathione S-transferase placental form-positive foci, assayed as putative preneoplastic lesions, the levels of 8-hydroxyguanine (8-OHG), a parameter of oxidative DNA damage, and the bromodeoxyuridine labeling indices (BrdU L.I.) by all three doses in the DEN-initiated case and, more prominently, in the CDAA diet-associated case. In contrast, while tRA failed to exert inhibitory effects apparently on foci development, 8-OHG formation or BrdU labeling in the DEN-initiated case, it reduced the numbers and sizes of the foci, the 8-OHG levels and the BrdU L.I. by all three doses in the CDAA diet-associated case. Furthermore, both 4-HPR and tRA inhibited the CDAA diet-associated induction of hepatocyte necrosis and connective tissue increase but not intrahepatocellular fat accumulation. These results indicate that 4-HPR exerts chemopreventive effects against the exogenous and endogenous rat liver carcinogenesis, while tRA can inhibit only the latter.

Effect of dietary ascorbic acid on the hepatic microsomal mixed function oxidase system in liver of chicks treated with Escherichia coli lipopolysaccharide

We determined whether dietary ascorbic acid (0.3 or 3 g/kg diet) modulates hepatic microsomal mixed function oxidase (MFO) system and plasma alpha 1 acid glycoprotein (AGP) concentration in chicks treated with Escherichia coli lipopolysaccharide (LPS). Injection of LPS (250 micrograms/kg body weight every other day) intraperitoneally for 14 days decreased cytochromes P450 and b, content and NADPH-cytochrome c reductase activity in hepatic microsomes in male broilers. Content of cytochromes P450 and b5 was negatively correlated with plasma AGP concentration. Feeding ascorbic acid partly alleviated the reduction of cytochromes P450 and b5 in males. Plasma AGP concentration also increased with the LPS injection and was partly lowered by feeding ascorbic acid. The results indicate that dietary ascorbic acid modulates the responses of the microsomal MFO system and of plasma AGP concentration against repeated injection of LPS in male broiler chicks.

Pharmacologic profiles of KRH-594, a novel nonpeptide angiotensin II-receptor antagonist

We studied pharmacologic profiles of KRH-594, dipotassium (Z)-2-[[5-ethyl-3-[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl-1,3,4 -thiadiazolin-2-ylidene]aminocarbonyl]-1-cyclopentenecarb oxylate, a novel angiotensin II (AII)-receptor antagonist. KRH-594 potently displaced specific binding of [125I]-AII from AT1 receptor with a Ki of 0.39 nM in rat liver membranes, but not from AT2 receptor in bovine cerebellar membranes (Ki > 10 microM). KRH-594 exhibited no affinity for 21 other receptors and two enzymes [50% inhibitory concentration (IC50) > 10 microM], demonstrating its high specificity toward AT1 receptors. In isolated rabbit aorta, KRH-594 caused nonparallel shifts to the right of the dose-response curve to AII and decreased the maximal response with a pK(B) of 10.4. We evaluated the in vivo efficacy and the duration of action in freely moving rats under nonfasting conditions. In normotensive rats, orally administered KRH-594 inhibited AII-induced pressor responses with a 50% inhibitory dose (ID50) of 0.39 mg/kg. In spontaneously hypertensive rats (SHRs), both KRH-594 (1 mg/kg p.o.) and losartan (10 mg/kg p.o.) exerted similar blood pressure-reducing effects, and their effects were still significant at 24 h after drug administration. We concluded that KRH-594 is a specific and efficacious AT1 antagonist that may find its use in the treatment of human hypertension.

Deuterium oxide (heavy water) accelerates actin assembly in vitro and changes microfilament distribution in cultured cells

While deuterium oxide (D2O) is known to produce various biological effects in living animals and cultured cells, the detailed mechanisms by which it does so remain unclear. The present study was designed to assess the effects of D2O on microfilaments (MFs) via fluorescence staining of BALB 3T3 cells and in vitro actin polymerization studies. After BALB 3T3 cells had been exposed to a concentration of more than 30% D2O for several hours, stress fibers in the peripheral region became thick and distinct, while the quantity of perinuclear MFs was drastically reduced. This effect was transient and returned to the original distribution within 12 h. Cytoplasmic F-actin (FA) also increased transiently coincident with the enhancement of stress fibers. The pattern of cell locomotion became simpler, and total locomotor activity was suppressed in a D2O concentration-dependent manner. Analysis of in vitro studies demonstrated that, when purified G-actin was polymerized in D2O at a concentration greater than 10%, the rate of actin polymerization was accelerated, whereas the total amount of polymerized actin at the steady state in D2O was the same as that in H2O controls. A gelation assay and transmission electron microscopy (TEM) showed that the network of crosslinked FA with alpha-actinin became denser in 30% D2O than in H2O. These findings concerning actin polymerization and FA gelation suggest that the alteration of stress fibers in cultured cells is caused by a direct effect of D2O on cellular MF dynamics.

Treatment of refractory cases of atopic dermatitis with acidic hot-spring bathing

The incidence of refractory atopic dermatitis has increased in teenagers and young adults. The purpose of this study was to control the skin symptoms of such patients in daily life. Seventy patients repeatedly took a 10-min 42 degrees C acidic hot-spring bath twice daily. The skin symptoms were improved in 76% of cases. In 30 of 42 responders examined Staphylococcus aureus, detected on the skin surface, disappeared or decreased through balneotherapy. In contrast, S. aureus remained unchanged in 8 of 10 non-responders examined. Thus, the balneotherapy using acidic hot-spring water may be useful for controlling the skin symptoms of acute flares of refractory cases of atopic dermatitis.

Comparison of the effects of various fine particles on IgE antibody production in mice inhaling Japanese cedar pollen allergens

The adjuvant effects of various fine particles [Kanto loam dust, fly ash, carbon black, diesel exhaust particles (DEP), and aluminum hydroxide (alum)] on immunoglobulin E (IgE) antibody production in female BDF1 mice were examined. In experiment 1, animals both received 25 micrograms of each particle intranasally and were exposed to aerosolized Japanese cedar pollen allergens (JCPA) for 30 min/d at 1-wk intervals for the first 8 wk. This was followed by exposure for 30 min every 3 wk for the next 9 wk. As parameters of allergic rhinitis, measurements were made of JCPA-specific IgE and IgG antibody titers, the protein-adsorbing capacity of each type of particle, and nasal rubbing movements. The increases in anti-JCPA IgE and IgG antibody production in mice treated with aerosolized JCPA plus respective particles were significantly greater than that found with aerosolized JCPA alone. This was associated with no marked differences in the other allergic rhinitis parameters. In experiment 2, after the administration of particles as in experiment 1, about 160,000 grains of Japanese cedar pollen (JCP, native dry pollen) were dropped onto the tip of the nose of mice twice a week for 16 wk. Six weeks after the first immunization, the anti-JCPA IgE antibody titers of groups treated with the respective particles were greater than 1:20, whereas those of mice treated with JCP alone were 1:10. No significant differences in the anti-JCPA IgE and IgG antibody productions, nasal rubbing counts, or histopathological changes were observed after 18 wk. These results suggested the nature of the particles, their capacity to adsorb antigens, and/or their size may not be related to enhancement of IgG antibody production nor symptoms of allergic rhinitis. However, IgE antibody production seemed to occur earlier in mice treated with particles than in mice immunized with allergens alone.

Involvement of RBP-J in biological functions of mouse Notch1 and its derivatives

Notch is involved in the cell fate determination of many cell lineages. The intracellular region (RAMIC) of Notch1 transactivates genes by interaction with a DNA binding protein RBP-J. We have compared the activities of mouse RAMIC and its derivatives in transactivation and differentiation suppression of myogenic precursor cells. RAMIC comprises two separate domains, IC for transactivation and RAM for RBP-J binding. Although the physical interaction of IC with RBP-J was much weaker than with RAM, transactivation activity of IC was shown to involve RBP-J by using an RBP-J null mutant cell line. IC showed differentiation suppression activity that was generally comparable to its transactivation activity. The RBP-J-VP16 fusion protein, which has strong transactivation activity, also suppressed myogenesis of C2C12. The RAM domain, which has no other activities than binding to RBP-J, synergistically stimulated transactivation activity of IC to the level of RAMIC. The RAM domain was proposed to compete with a putative co-repressor for binding to RBP-J because the RAM domain can also stimulate the activity of RBP-J-VP16. These results taken together, indicate that differentiation suppression of myogenic precursor cells by Notch signalling is due to transactivation of genes carrying RBP-J binding motifs.

[Circadian variation of blood pressure and heart rate in normotensive pre- and postmenopausal women]

The aim of this study was to assess the effect of menopause on circadian profile of blood pressure (BP) and heart rate (HR) in the normotensive pre- and postmenopausal women. Systolic BP (SBP), diagnostic BP (DBP) and HR were monitored every 30 min for 48 hrs using noninvasive ambulatory BP monitoring in 24 premenopausal and 40 postmenopausal women. Mean 48-hours, daytime (awake), and nighttime (sleeping) SBP, DBP and HR values were analyzed by reviewing the patients' diaries, and the nocturnal reduction rate (NRR) of SBP, DBP and HR were calculated according to the following formula. NRR (%9 = [(daytime mean-nighttime mean)/daytime mean] x 100. The study subjects were then divided into two groups according to the presence (dipper) or absence (nondipper) of a significant reduction in nocturnal BP (> 10%). Mean SBP, DBP and HR measured over 48 hours were similar between the premenopausal and the postmenopausal group. The NRR of DBP and HR in the postmenopausal group were significantly smaller than those in the premenopausal group (17.1 +/- 6.0% vs. 13.5 +/- 7.0%, 241.1 +/- 6.0% vs. 19.8 +/- 9.0%: p < 0.05). There tended to be higher prevalence of nondipper in the postmenopausal (37%) than in the premenopausal group (29%).

Evaluation of the AMPLICOR CMV test for direct detection of cytomegalovirus in plasma specimens

We evaluated the AMPLICOR CMV test (PCR) for the direct detection of cytomegalovirus in plasma. Sixty-eight specimens were involved for the comparison between the AMPLICOR test and the antigenemia assay. The sensitivities, specificities, and positive and negative predictive values were 97.1, 100, 100, and 97.1%, respectively, for the AMPLICOR test and 79.4, 100, 100, and 82.9%, respectively, for the antigenemia assay.

Gianotti-Crosti syndrome associated with cytomegalovirus antigenemia after bone marrow transplantation

Gianotti-Crosti syndrome (GCS) is characterized by a distinctive self-limiting acral papular or papulovesicular eruption associated with an underlying viral illness. It has not been previously reported in patients post-bone marrow transplantation. We report a 6-year-old Japanese boy who underwent allogeneic bone marrow transplantation from an unrelated donor for acute lymphoblastic leukemia (ALL) in second remission. He had clinical and histopathologic findings characteristic of GCS and evidence of subclinical infection with cytomegalovirus (CMV) detected by CMV antigenemia assay. It is likely that CMV is the causative agent for the GCS in this case.

Tissue angiotensinogen gene expression induced by lipopolysaccharide in hypertensive rats

There is now convincing evidence that various tissues express their own tissue renin-angiotensin system, which may be regulated independently of the systemic renin-angiotensin system. However, little information is available on the regulation of the tissue renin-angiotensin system. We investigated the regulation of tissue angiotensinogen gene expression with respect to the development of hypertension. We measured basal and lipopolysaccharide-stimulated plasma angiotensinogen concentrations by radioimmunoassay and examined the expression of tissue angiotensinogen by Northern blot analysis in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) at 4 and 13 weeks of age. Basal plasma angiotensinogen concentration in SHR was comparable to that in WKY at 4 weeks of age and was significantly higher than that in WKY at 13 weeks of age. Lipopolysaccharide induced a significant increase in plasma angiotensinogen concentration in both WKY and SHR at 4 and 13 weeks of age. At 4 weeks of age, the basal levels of angiotensinogen mRNA in the liver, fat, adrenal, and aorta were higher in WKY than in SHR. At 13 weeks of age, the basal levels of angiotensinogen mRNA in the fat, adrenal, aorta, spleen, and kidney were higher in WKY than in SHR, while that in the liver did not differ significantly between the two strains. At 4 weeks of age, pretreatment with lipopolysaccharide increased the angiotensinogen mRNA levels in the liver, fat, adrenal, and aorta in both WKY and SHR. At 13 weeks of age, pretreatment with lipopolysaccharide increased the angiotensinogen mRNA levels in the liver, aorta, and adrenal; decreased those in the spleen; and had no effect in the kidney in both WKY and SHR. Interestingly, lipopolysaccharide increased the angiotensinogen mRNA level in fat only in SHR, with no effect in WKY, at 13 weeks of age. Lipopolysaccharide stimulated tumor necrosis factor-a mRNA expression in fat of WKY and SHR, and the increase in tumor necrosis factor-alpha mRNA level in SHR was significantly greater than that in WKY. Therefore, the increased tumor necrosis factor-alpha mRNA expression may be involved in the increased lipopolysaccharide-induced expression of angiotensinogen gene in fat of SHR at 13 weeks of age. These data suggest that the transcriptional and probably posttranscriptional regulation of angiotensinogen mRNA differs between SHR and WKY, that the regulation of angiotensinogen gene expression is tissue-specific, and that the altered expression of the angiotensinogen gene may be involved in the development of hypertension.

Angiotensin-converting enzyme gene I/D polymorphism and carotid plaques in Japanese

To clarify the role of genetic factors in atherosclerotic plaque formation in the carotid artery and magnetic resonance imaging abnormalities in the brain, we investigated the association of these abnormalities with the angiotensin-converting enzyme (ACE) genotype. One hundred sixty-nine subjects (age, 59.2+/-0.8 years, mean+/-SE) admitted to our hospital for health checkups underwent brain magnetic resonance imaging to evaluate lacunar infarction. B-mode ultrasound examinations of the carotid arteries were performed to detect atherosclerotic plaque. The I/D polymorphism of the ACE gene was determined by the polymerase chain reaction method. Multivariate regression analysis was performed to assess the effects of the following variables on the presence of plaque, mean plaque thickness, and number of plaques: fibrinogen, sex, age, body mass index, mean blood pressure, glycosylated hemoglobin, LDL cholesterol, HDL cholesterol, hematocrit, and the D allele of the ACE gene. The frequency of carotid atherosclerotic plaque was significantly (P=.034) higher in subjects with the D allele than in those without this allele. However, the frequency of lacunar stroke was similar in these groups. A multivariate regression analysis showed that the presence of plaque was independently associated with the D allele (odds ratio=3.27, P=.016). However, mean plaque thickness and the number of plaques were not associated with the D allele. The D allele of the ACE gene may be involved in the presence of carotid plaque but not in the extent of this plaque or asymptomatic lacunar stroke in Japanese subjects.

Chronotherapy for coronary heart disease

Traditionally the therapy for coronary heart disease has been focused on the "how-to" problem. However, the clustering of cardiovascular events around the specific time of the day has been clarified. To solve the problems of the clustering would give us the clue to treat the coronary heart disease timely and in time. Therefore, the research has been stressed to solve "when-to" problem. The circadian variabilities in coronary heart disease has been clarified to be the function of the biologic time. Therefore, three problems were discussed in this paper. 1) The circadian variabilities in biology should be assessed based on the biologic zero hour rather than the mid-night of the mechanical clock. Our concept of the biologic zero hours has been proposed to answer this problem. 2) Daily health care with circadian order and harmony for the prevention of the coronary risk factors should be recommended as the prevention of the acute coronary risk factors as the trigger mechanism of the cardiovascular events. 3) The chronotherapy to chronic coronary risk factors such as hypertension was discussed, In hypertension the anti-hypertensive therapy should be customized individually adjusting the circadian variability of blood pressure with the proper selection of agents and time of the administration.

Angiotensin-converting enzyme gene polymorphism adds risk for the severity of coronary atherosclerosis in smokers

To investigate the relation between the angiotensin-converting enzyme (ACE) gene polymorphism and acute coronary syndromes with respect to environmental factors, we analyzed the association of genotype with the coronary angiographic findings of patients with acute myocardial infarction or unstable angina pectoris, and we examined the linkage of each genotype with established risk factors for coronary artery disease. We determined the ACE genotype in 152 Japanese patients with acute coronary syndromes and 399 healthy individuals. The genotype distributions were not different between the two groups (P=.74, chi2 test). In the former group, coronary angiograms were evaluated by criteria based on the number of diseased vessels, the number of stenotic lesions (> or = 50%), and the relative abnormal arterial portion (extent index). Although the number of stenotic lesions was higher in patients with the DD genotype than in those with the ID or II genotype (P=.006), there were no differences in the number of diseased vessels or the extent index. When only smokers were analyzed, the number of diseased vessels (P=.032), number of stenotic lesions (P=.003), and extent index (P=.019) were all higher in patients with the DD genotype than in those with the ID or II genotype. In contrast, these differences in the respective parameters did not exist in nonsmokers. The results indicate smoking-associated effects of the ACE genotype on the severity of coronary atherosclerosis.

Effect of stereochemistry on the transport of Aca-linked beta-turn peptidomimetics across a human intestinal cell line

Transcellular transport is one of the most important barriers facing the development of new therapeutic agents. However, little is known about the specific effects of structure and particularly stereochemistry on cell permeability. An attractive in vitro model has been developed for the direct assessment of cell transport, using the immortalized human epithelial cell line, Caco-2. The present study assesses the effects of stereochemistry on transport in a commonly used beta-turn model system. Thus, L,L- and L,D-Ala-Ala were cyclized with aminocaproic acid, resulting in macrocycles in which the dipeptides correspond to the i + 1 and i + 2 positions of a beta-turn. The transport of these dipeptides across a Caco-2 cell monolayer was determined, along with corresponding acyclic models (L,L- and L,D-CH3CH2C(O)-Ala-Ala-n-Pr). The transport studies were carried out in the presence and absence of verapamil, a known inhibitor of the apically polarized efflux system present in Caco-2 cells. Both apical-->basolateral and basolateral-->apical transport were measured. Measurements made in the presence of verapamil showed that the cyclic peptides experienced a ca. 4-5-fold difference in intrinsic flux depending on stereochemistry, with the L,D isomer being transported at a higher rate. These differences disappeared in the acyclic cases examined (permeability coefficient ratios of the L,D/L,L isomers were 1.04-1.13). These observations are discussed in terms of the conformations and hydrogen-bonding characteristics of the compounds as determined by NMR spectroscopy.

Clinicopathological significance of epidermal growth factor and its receptor in human pancreatic cancer

The expression of epidermal growth factor (EGF) and its receptor (EGF-R) was examined immunohistochemically in 60 primary and 26 metastatic lesions of pancreatic carcinoma. EGF was stained mainly in the cytoplasm of tumor cells, and EGF-R was stained mainly on the surface of cells. The expression rates of EGF and EGF-R were 28% and 43% for primary lesions, and 46% and 46% for metastatic lesions, respectively. The expression of EGF and EGF-R alone did not correlate with any clinicopathological factors such as clinical stage, tumor size, nodal involvement, histology, etc. The median survival period after pancreatectomy was 21.4 months for patients with EGF(+) cancers and 25.1 months for those with EGF (-) ones. On the other hand, the median survival period was 22.7 months for patients with EGF-R (+) cancers and 25.0 months for those with EGF-R (-) cancers. There were no significant differences in survival between groups of patients differing in EGF or EGF-R expression. When the expression of EGF and EGF-R was analysed in combination, the survival curve of patients with EGF(+) and EGF-R(+) cancers was found to be lower than that of the rest of the patients (p = 0.07), and especially the survival curve of patients with EGF(+)EGF-R(+) cancers was significantly lower than that of patients with EGF(+)EGF-R(-) cancers (p = 0.02), and EGF(-)EGF-R(+) cancers (p = 0.06). These results indicate that the expression of EGF or EGF-R alone in pancreatic cancer does not reflect the prognosis of patients; however the coexpression of EGF and EGF-R may be a beneficial prognostic factor for pancreatic cancer.

Retinoic acid changes the proximodistal developmental competence and affinity of distal cells in the developing chick limb bud

In the developing chick limb bud, retinoic acid (RA) has a striking effect on anteroposterior axis formation, resulting in a duplicated pattern of digits. There is no evidence, however, that RA affects proximodistal axis formation in the developing chick limb bud, although RA induces proximodistal duplication in regenerating amphibian limbs. We describe a series of investigations on the effect of RA on the proximodistal axis in the chick limb bud. A RA-containing bead applied to the anterior margin of the chick limb bud at stage 20 induces the anteroposterior duplication of autopodial structures at the wrist level. We found that the RA-treated tissue has the ability to form more proximal structures. When a tissue graft from the RA-treated anterior region was implanted into a stage 17 wing bud (in which the stylopod is developing in the progress zone), the graft produced a humerus, radius-ulna, and digits. When the graft was implanted into a stage 19 wing bud (in which the zeugopod is developing in the progress zone), a zeugopod and digits were formed. These results were associated with changes in the expression of Hox-A genes in the RA-treated grafts, whose domains were reorganized to be similar to those in host tissues 24 h after grafting. When a small graft of RA-treated tissue was implanted into the apex of a stage 19 wing bud, the cells were found in the zeugopod and autopod, whereas cells of control fragments were found only in the autopod region. In vitro, distal cells from different stage limb buds are known to segregate from each other. However, RA-treated stage 24 distal cells did not sort out from stage 20 distal cells and mixed homogeneously. These results suggest that RA induces distal cells to adopt "younger" properties which render them susceptible to forming more proximal patterns under the direction of host signals. The effects of RA on proximodistal patterns in developing chick limb buds appear to differ from its effects on proximodistal patterns in regenerating urodele limbs because RA can induce the proximodistal duplication in situ in the regenerating limbs.

A quinolinone derivative, vesnarinone (OPC-8212), significantly inhibits the in vitro and in vivo growth of human pancreatic cancer cell lines

A quinolinone derivative, vesnarinone, has been used as a cardiotonic agent. Previous studies have demonstrated that vesnarinone has potent antitumor activity. The present study was designed to assess the antitumor effects of vesnarinone on human pancreatic cancer cell lines in vitro and in vivo. The in vitro effects of vesnarinone on the human pancreatic cancer cell lines (PANC-1, MIA PaCa-2 and BxPC-3) were assessed by the MTT assay, the Trypan blue dye exclusion test and the Matrigel invasion chamber assay. The inhibition of in vivo tumor growth was evaluated on two human pancreatic cancer xenografts (BxPC-3 and SPa-1) transplanted s.c. into nude mice. The dose of vesnarinone for 50% inhibition of cell growth in a 7 day culture ranged between 10 and 20 micrograms/ml as verified by the Trypan blue dye exclusion test. The dose for 50% cytotoxicity after a 3 day culture in the MTT assay was 32 micrograms/ml for PANC-1 and 30 micrograms/ml for BxPC-3, but 50% cytotoxicity for MIA PaCa-2 was not achieved by the maximal dose of vesnarinone (50 micrograms/ml). Nomalsky optic microscopy and acridine orange staining demonstrated the vacuolization and crater-like changes in the cell nucleus after vesnarinone treatment. Moreover, staining of an apoptosis marker (Le(y) protein) and nick end-labeling increased. Vesnarinone also inhibited cancer invasion in the Matrigel invasion chamber assay. In vivo, BxPC-3 and SPa-1 were s.c. transplanted into the nude mice, and vesnarinone (5 or 50 mg/kg) was daily administered orally for 21 days. In both lines, vesnarinone at 50 mg/kg achieved significant inhibition. The present study suggests that vesnarinone may be a new therapeutic agent for pancreatic cancer.

Identification of an ubiquitin-ligation system for the epidermal-growth-factor receptor--herbimycin A induces in vitro ubiquitination in rabbit-reticulocyte lysate

Some receptor tyrosine kinases such as the receptors for epidermal-growth factor (EGF) and platelet-derived growth factor undergo polyubiquitination as a consequence of ligand binding. The EGF receptor is also ubiquitinated by treatment with herbimycin A, an ansamycin antibiotic widely used as a tyrosine kinase inhibitor. To investigate the mechanism of the receptor ubiquitination, we have established an assay system in which herbimycin-A-induced ubiquitination processes can be analyzed in vitro. We now show that herbimycin A treatment of the purified EGF receptor induces polyubiquitination of the receptor in rabbit-reticulocyte lysate. Both DEAE unadsorbed material (fraction I) and high salt eluate (fraction II) of the reticulocyte lysate are involved cooperatively in the ubiquitination process, where the ubiquitin-conjugating enzyme UBC4 can functionally substitute for fraction I. A ubiquitin-protein ligase-like activity, partially purified from fraction II by DEAE anion-exchange chromatography, also functions in concert with UBC4. The precise mechanism of herbimycin A-induced ubiquitination of the EGF receptor is not fully understood, however, our present findings suggest that direct interaction with herbimycin A results in some modification of the receptor which is recognized by the ubiquitin-conjugating system in rabbit-reticulocyte lysate.

Xanthogranulomatous pyelonephritis

A 76-year-old woman presented with spiking fever and right back pain. Ultrasonography (US) revealed that her right kidney was enlarged. Computed tomography (CT) showed the parenchyma was replaced by non-enhancing masses but the overall kidney shape was maintained. These findings were compatible with those of xanthogranulomatous pyelonephritis (XP). The nonenhancing masses on CT coincided with the multiple butter yellow nodules of the resected kidney and microscopically these lesions were proved to be abscesses with xanthoma cells. In this case, the US and CT findings reflected the pathological feature of XP and thus these techniques are thought to be useful for the diagnosis of XP.

In vitro pharmacological properties of KRH-594, a novel angiotensin II type 1 receptor antagonist

This report describes the in vitro pharmacological properties of dipotassium (Z)-2-[[5-ethyl-3-[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl-1, 3,4-thiadiazolin-2-ylidene]aminocarbonyl]-1-cyclopentenec arboxylate, called KRH-594, a novel angiotensin II (AII) type 1 (AT1) receptor antagonist. We exposed rabbit aortic rings to KRH-594 (0.1 nM) for increasing contact times and observed an increasing degree of insurmountable suppression of AII-induced contractions. KRH-594 (0.01, 0.1 and 1.0 nM) caused a concentration-related, insurmountable suppression of the AII concentration-response curve. Repeated washing of rabbit aortic rings preincubated with KRH-594 (0.1, 1.0 and 10 nM) slowly reversed the insurmountable suppression. The marked suppression of AII-induced contractions by KRH-594 (0.1 nM) was restored by co-incubation with losartan (100 nM). KRH-594 (10 microM) had no effect on bradykinin-, acetylcholine-, or histamine-induced contractions of guinea pig ileum, demonstrating its high specificity for AT1 receptors. These results demonstrate that KRH-594 is a potent, specific and insurmountable AT1 receptor antagonist. KRH-594 activity in rabbit aorta appears to be that of a slowly reversible (pseudo-irreversible) antagonist.

Mucosal blood flow and generation of superoxide in rat experimental colitis induced by succinic acid

As we consider succinic acid to be an exacerbating factor in ulcerative colitis, we investigated its influence on rat colonic mucosa in terms of mucosal blood flow and superoxide generation. We measured mucosal blood flow by the hydrogen gas clearance method and superoxide generation by the chemiluminescence method, and observed histopathological findings to determine the effects of succinic acid. After the instillation of succinic acid of any concentration tested to the colon, mucosal blood flow decreased. Histopathologically, the higher the concentration of succinic acid, the greater was the erosion formation in the colonic mucosa, while significant polymorpho-nuclear cell infiltration superoxide generation from colon tissue were observed with 0.01% succinic acid compared with higher or lower concentrations. Succinic acid, at fecal concentrations found in active stage ulcerative colitis, appears to be implicated in mucosal injury, mediated by a decrease in colonic mucosal blood flow and infiltration of superoxide-generating polymorpho-nuclear cells into the mucosa.

Inhibitory effect of a new steroidal saponin, OSW-1, on ovarian functions in rats

1. This study was undertaken to determine the effects of OSW-1 (3 beta, 16 beta, 17 alpha-trihydroxycholest-5-en-22-one 16-O-(2-O-4-methoxybenzoyl-beta-D-xylopyranosyl)- (1-->3)-(2-O-acetyl-alpha-L-arabinopyranoside)) on the pituitary-ovarian system and the functions of aortic smooth muscle. 2. A single s.c. injection of OSW-1 (9 micrograms kg-1) on the morning of pro-oestrus inhibited the occurrence of the expected next pro-oestrus, whereas administration of OSW-1 at a dose of 4.5 micrograms kg-1 did not affect the oestrous cycle. OSW-1 treatment on the day of dioestrus-1 did not affect the oestrous cycle. 3. At doses of 4.5 and 9 micrograms kg-1 OSW-1, the serum oestradiol (E2) levels at the expected next pro-oestrus were significantly lower than in control (pro-oestrus). The serum luteinizing hormone (LH) levels 4 days after 9 micrograms kg-1 OSW-1 treatment were also markedly lower than those of control. OSW-1 (4.5 micrograms kg-1) did not affect the levels of inhibin, progesterone and gonadotrophins on the same day. 4. OSW-1 did not inhibit the preovulatory LH surge which occurs on the afternoon of pro-oestrus day. 5. The expression of mRNA coding for the cholesterol side chain cleavage cytochrome P-450 (p450scc), an ovarian steroidal limiting enzyme, was suppressed at 24 and 96 h after OSW-1 treatment. 6. Administration of OSW-1 (9 micrograms kg-1) tended to reduce the relaxation of isolated thoracic aorta ring preparations induced by acetylcholine, while there was no difference in the relaxation induced by sodium nitroprusside. 7. Our results show that OSW-1 inhibits ovarian E2 secretion and that the decrease in E2 secretion may contribute to its effects on the oestrous cycle and the sensitivity of the thoracic aorta to relaxation. The decrease in the levels of ovarian steroids induced by OSW-1 may be due to its direct inhibitory action on the gene expression of the steroidal enzyme and on the proliferation of granulosa cells in the ovary.

Experimental investigation of the role of the splenic vein in gastric venous obstruction after pylorus-preserving pancreatoduodenectomy in the dog

CONCLUSION

This study showed that the splenic vein (SV) plays a major role in maintaining gastric blood flow after ligature of peripyloric vessels in the dog. Therefore, SV preservation or alternative venous drainage may be recommended to maintain sufficient gastric blood flow in pylorus-preserving pancreatoduodenectomy (PPPD).

BACKGROUND

In PPPD, we often encounter the problem of gastric venous drainage obstruction, if the splenic-portal vein confluence needs to be resected. This study investigated significance of venous drainage via the left gastric and splenic veins in gastric tissue blood flow.

METHODS

In seven mongrel dogs, gastric tissue blood flow was measured by both laser Doppler flowmetry (LDF) in the antrum and hydrogen gas clearance (HGC) in the antrum and body. Blood flow was measured after the following treatments: 1. No treatment; 2. Duodenal transection; 3. Ligature of the right gastric and gastroepiploic arteries and veins; 4. Transient obstruction of the left gastric vein (LGV); 5. Transient obstruction of the SV with the LGV open; and 6. Obstruction of both the LGV and the SV.

RESULTS

As judged by LDF, treatments 2, 3, and 4 did not decrease blood flow, but treatments 5 and 6 significantly decreased it compared with both treatments 1 and 3. By HGC, changes in the antrum and the body were parallel. Duodenal transection did not, but treatments 3 and 4 did decrease blood flow compared with no treatment. Obstruction of the left gastric vein did not, but treatments 5 and 6 did significantly decrease it compared with treatment 3.