[Pulmonary hypertension in endothelial NO synthase knockout mice]

Inhalation of nitric oxide (NO) effectively reduces pulmonary arterial pressure in patients with pulmonary hypertension. However, it is controversial as to the role of endothelium-derived NO in pulmonary hypertension. Disruption of endothelial NO synthase (eNOS) gene causes systemic hypertension and diminishes endothelium-dependent vasodilatation. Even at normoxia eNOS knockout mice showed slightly increased right ventricular systolic pressure, but normal right ventricular weight. Hypoxia increased right ventricular systolic pressure, hematocrit, right ventricular weight in a concentration-dependent manner. The hypoxic condition induced pulmonary vascular remodeling; increases in the ratio of fully muscular vessels. Thus, pulmonary hypertension in eNOS knockout mice may be due to exaggerated vasoconstriction in response to hypoxia. In contrast, eNOS gene transduction reduces pulmonary vascular resistance.

L-Arginine given after ischaemic preconditioning can enhance cardioprotection in isolated rat hearts

OBJECTIVE

Ischaemic or pharmacological preconditioning with L-arginine has been reported to be insufficient for optimal cardioprotection. The ability of nitric oxide (NO) to enhance ischaemic preconditioning was assessed, and the role of L-arginine-induced ischaemic preconditioning in myocardial protection was determined.

METHODS

Isolated rat hearts were prepared and divided into six groups: control hearts (control, n=6) were perfused without global ischaemia at 37 degrees C for 160 min; global ischaemia hearts (GI, n=6) were subjected to ischaemia for 20 min and reperfusion for 120 min; ischaemic preconditioned hearts (IP, n=6) received 2 min of zero-flow global ischaemia followed by 5 min reperfusion, before 20 min of global ischaemia; L-arginine hearts (ARG, n=6) received 1 mmol/l L-arginine for 5 min, before 20 min of global ischaemia; ischaemic preconditioning plus nitro-L-arginine methyl ester hearts (IP+L-NAME, n=6) received 2 min of ischaemic preconditioning and 5 min reperfusion with 3 mmol/l L-NAME in Krebs-Henseleit buffer, before 20 min of global ischaemia; and ischaemic preconditioning plus L-arginine hearts (IP+ARG, n=6) received 2 min of ischaemic preconditioning and 5 min reperfusion with 1 mmol/l L-arginine in Krebs-Henseleit buffer. Haemodynamic parameters and coronary flow were recorded continuously. Nitrites and nitrates (NOx) were measured 5 and 60 min after reperfusion, and infarct size was also determined.

RESULTS

In the IP+ARG group, significant amelioration and preservation of left ventricular peak developed pressure and coronary flow was observed compared with the GI, IP, ARG and IP+L-NAME groups. Infarct size in the IP+ARG group was reduced significantly compared with that in the GI, IP, ARG and IP+L-NAME groups. Significant preservation of NOx was observed during reperfusion in the IP+ARG group compared with the GI group.

CONCLUSIONS

Inhibition of NO synthase with L-NAME had little impact on ischaemic preconditioning, suggesting that endogenous NO is not a major mediator of ischaemic preconditioning. Nevertheless, enhancement of the effects of ischaemic preconditioning can be achieved with L-arginine, a precursor of NO, improving post-ischaemic functional recovery and infarct size in the isolated rat heart.

Acute Adaptation of the Vestibuloocular Reflex: Signal Processing by Floccular and Ventral Parafloccular Purkinje Cells

The gain of the vertical vestibuloocular reflex (VVOR), defined as eye velocity/head velocity was adapted in squirrel monkeys by employing visual-vestibular mismatch stimuli. VVOR gain, measured in the dark, could be trained to values between 0.4 and 1.5. Single-unit activity of vertical zone Purkinje cells was recorded from the flocculus and ventral paraflocculus in alert squirrel monkeys before and during the gain change training. Our goal was to evaluate the site(s) of learning of the gain change. To aid in the evaluation, a model of the vertical optokinetic reflex (VOKR) and VVOR was constructed consisting of floccular and nonfloccular systems divided into subsystems based on the known anatomy and input and output parameters. Three kinds of input to floccular Purkinje cells via mossy fibers were explicitly described, namely vestibular, visual (retinal slip), and efference copy of eye movement. The characteristics of each subsystem (gain and phase) were identified at different VOR gains by reconstructing single-unit activity of Purkinje cells during VOKR and VVOR with multiple linear regression models consisting of sensory input and motor output signals. Model adequacy was checked by evaluating the residual following the regressions and by predicting Purkinje cells' activity during visual-vestibular mismatch paradigms. As a result, parallel changes in identified characteristics with VVOR adaptation were found in the prefloccular/floccular subsystem that conveys vestibular signals and in the nonfloccular subsystem that conveys vestibular signals, while no change was found in other subsystems, namely prefloccular/floccular subsystems conveying efference copy or visual signals, nonfloccular subsystem conveying visual signals, and postfloccular subsystem transforming Purkinje cell activity to eye movements. The result suggests multiple sites for VVOR motor learning including both flocculus and nonflocculus pathways. The gain change in the nonfloccular vestibular subsystem was in the correct direction to cause VOR gain adaptation while the change in the prefloccular/floccular vestibular subsystem was incorrect (anti-compensatory). This apparent incorrect directional change might serve to prevent instability of the VOR caused by positive feedback via the efference copy pathway.

Enhancement of endothelial nitric oxide production by chenodeoxycholic acids in patients with hepatobiliary diseases

The purpose of this study was to clarify whether physiological concentrations of bile acids could affect endothelial nitric oxide production. We investigated the relationships between clinical concentrations of individual bile acids observed in patients with hepatobiliary diseases and endothelial nitric oxide production induced by each bile acid. Fifteen serum bile acids were measured using high-performance liquid chromatography combined with enzymatic fluorometry in 8 patients with liver cirrhosis, obstructive jaundice, and 8 healthy subjects. The effects of individual bile acids on nitric oxide production were examined in human umbilical endothelial cells by measuring the concentration of NO2- in the cultured medium. NO release in the blood was also determined by measuring the NO2-/NO3- concentration in these patients. In patients with hepatobiliary diseases, the plasma concentrations of chenodeoxycholic acid, ursodeoxycholic acid and cholic acid (free acid, taurine and glycine conjugates) were markedly elevated. Incubation of cells with chenodeoxycholic acid and deoxycholic acid (free acid, taurine and glycine conjugates) enhanced NO2- production in a concentration-dependent manner, while cholic acid (free and its conjugates) did not. The effects of individual bile acids on nitric oxide production were additive. Patients with liver cirrhosis and obstructive jaundice had higher plasma levels of NO2-/NO3- levels than the control subjects. These results suggest that increased plasma concentrations of chenodeoxycholic acid (free, taurine and glycine conjugates) in patients with hepatobiliary diseases may induce endothelial nitric oxide production. Thus, nitric oxide production induced by bile acids may be involved in the pathogenesis of circulatory abnormalities in patients with liver diseases.

Intra-abdominal metastases in musculoskeletal sarcomas

This study examined the incidence, histological type, clinical symptoms, and prognosis in patients with intra-abdominal metastases of musculoskeletal sarcomas. The medical records of 505 patients with musculoskeletal sarcomas were reviewed for examples of intra-abdominal metastases. The incidence of intra-abdominal metastases (excluding lung) was: 4% in the liver (20 patients), 1.2% in gastrointestine (6 patients), 0.8% in pancreas (4 patients), and 0.8% on the peritoneal surface (4 patients). Patients with a previous hisory of lung metastases and those with high-grade liposarcoma tended to show metastasis in the intra-abdominal organs. Most patients with liver metastasis had no symptoms. Patients with gastrointestinal metastasis had abdominal pain, anemia, and melena. Patients with pancreatic metastasis had diabetes and jaundice. Six patients underwent surgical treatment, and two of them survived for more than 2 years. Metastases within the abdomen must be considered as a possible site for dissemination of musculoskeletal sarcomas, especially in patients with advanced disease and those with liposarcoma.

Antiangiogenesis signals by endostatin

Endostatin is a potent endogenous angiogenesis inhibitor that induces regression of tumors in mice. Neither an extracellular receptor for endostatin nor intracellular signals that result in the regression of tumor vascular beds have been identified. We demonstrate that endostatin, but not angiostatin, at comparable concentrations to those used in in vivo animal trials, rapidly down-regulates many genes in exponentially growing endothelial cells. These include immediate early response genes, cell cycle-related genes, and genes regulating apoptosis inhibitors, mitogen-activated protein kinases, focal adhesion kinase, G-protein-coupled receptors mediating endothelial growth, a mitogenic factor, adhesion molecules, and cell structure components. Suppression of both apoptosis inhibitors and cell proliferation genes may have a limited contribution to the antiangiogenesis process because endostatin induces neither apoptosis nor growth inhibition, unless studied under reduced serum conditions. In contrast, the antimigratory effect of endostatin was rapid and potent even under serum-supplemented conditions. Endostatin caused gene suppression and migration arrest exclusively in endothelial cells, most profoundly in microvascular endothelial cells. The c-myc null fibroblasts obtained by targeted homologous recombination showed an attenuated migration rate compared with isogenic parental cells, whereas the introduction of the c-myc gene into endothelial cells abrogated the antimigratory effect of endostatin. Inhibition of E-box-driven transcription by overexpressing max or mad suppressed endothelial migration. Thus, rapid down-regulation of genes by endostatin neither restores proliferating endothelial cells to their resting states nor induces apoptosis; rather, it potently inhibits endothelial cell migration partly via suppression of c-myc expression.

A pyrrolidinone derivative inhibits cytokine-induced iNOS expression and NF-kappaB activation by preventing phosphorylation and degradation of IkappaB-alpha

We previously showed that 1-[3-(3-pyridyl)-acryloyl]-2-pyrrolidinone hydrochloride (N2733) inhibits lipopolysaccharide (LPS)-induced tumour necrosis factor (TNF)-alpha secretion and improves the survival of endotoxemic mice. Since overproduction of nitric oxide (NO) by inducible NO synthase (iNOS) in vascular smooth muscle cells (VSMCs) is largely responsible for the development of endotoxemic shock, and iNOS gene expression is mainly regulated by LPS and inflammatory cytokines, we studied whether or not N2733 affects interleukin (IL)-1beta-induced iNOS gene expression, NF-kappaB activation, and NF-kappaB inhibitor (IkappaB)-alpha degradation in cultured rat VSMCs. N2733 dose-dependently (10-100 microM) inhibited IL-1beta-stimulated NO production, and decreased IL-1beta-induced iNOS mRNA and protein expression, as found on Northern and Western blot analyses, respectively. Gel shift assay and an immunocytochemical study showed that N2733 inhibited IL-1beta-induced NF-kappaB activation and its nuclear translocation. Western blot analyses involving anti-IkappaB-alpha and anti-phospho IkappaB-alpha antibodies showed that IL-1beta induced transient degradation of IkappaB-alpha preceded by the rapid appearance of phosphorylated IkappaB-alpha, both of which were markedly blocked by N2733. N2733 blocked IL-1beta-induced phosphorylated IkappaB-alpha even in the presence of a proteasome inhibitor (MG115). Immunoblot analysis involving anti-IkappaB kinase (IKK)-alpha and anti-phosphoserine antibodies revealed that N2733 inhibited IL-1beta-induced IKK-alpha phosphorylation, whereas N2733 had no inhibitory effect on IL-1beta-stimulated p42/p44 MAP kinase or p38 MAP kinase activity. Our results suggest that the inhibitory action of N2733 toward IL-1beta-induced NF-kappaB activation and iNOS expression is due to its blockade of the upstream signal(s) leading to IKK-alpha activation, and subsequent phosphorylation and degradation of IkappaB-alpha in rat VSMCs.

A patient with type 1 diabetes mellitus and cerebellar ataxia associated with high titer of circulating anti-glutamic acid decarboxylase antibodies

A 66-year-old Japanese woman presenting with recent onset of type 1 diabetes mellitus and cerebellar ataxia was admitted to our hospital. Physical examination on admission revealed coordinate disturbance due to cerebellar ataxia, and the laboratory examination showed marked hyperglycemia with ketosis and impaired insulin secretion. Anti-glutamic acid decarboxylase (GAD) antibodies in high titer were detected in patient's serum. Immunoblotting showed the patient's serum reacted with a 65 kDa protein in tissue extracts from rat pancreas and cerebellum, and immunohistochemical study produced positive immunostaining in the pancreatic islets of Langerhans, the axons of Purkinje cells and the nerve terminals in the granular layers of cerebellum of the rat. This is the first case presenting with concomitant type 1 diabetes and cerebellar ataxi associated with high titers of circulating anti-GAD antibodies which may play a critical role in the development of the diseases.

Akt phosphorylates and regulates the orphan nuclear receptor Nur77

The immediate early gene NUR77 (also called NGFI-B) is required for T cell antigen receptor-mediated cell death and is induced to very high levels in immature thymocytes and T cell hybridomas undergoing apoptosis. The Akt (PKB) kinase is a key player in transduction of anti-apoptotic and proliferative signals in T cells. Because Nur77 has a putative Akt phosphorylation site at Ser-350, and phosphorylation of this residue is critical for the transactivation activity of Nur77, we investigated whether Akt regulates Nur77. Coimmunoprecipitation experiments showed the detection of Nur77 in Akt immune complexes, suggesting that Nur77 and Akt physically interact. We further show that Akt specifically phosphorylates Ser-350 of the Nur77 protein within its DNA-binding domain in vitro and in vivo in 293 and NIH 3T3 cells. Because phosphorylation of Ser-350 of Nur77 is critical for its function as a transcription factor, we examined the effect of Akt on this function. By using luciferase assay experiments, we showed that phosphorylation of Nur77 by Akt decreased the transcriptional activity of Nur77 by 50--85%. Thus, we show that Akt interacts with Nur77 and inactivates Nur77 by phosphorylation at Ser-350 in a phosphatidylinositol 3-kinase-dependent manner, connecting the phosphatidylinositol 3-kinase-dependent Akt pathway and a nuclear receptor pathway.

L-canavanine, a selective inhibitor of inducible NO synthase, increases plasma endothelin-1 concentrations in dogs with endotoxic shock

PURPOSE

The purpose of this article is to elucidate the effect of L-canavanine, a selective inhibitor of inducible NO synthase (iNOS), on hemodynamics, blood gas parameters, and plasma concentrations of lactate and endothelin-1 (ET-1) during endotoxic shock.

MATERIALS AND METHODS

Eleven mongrel dogs under pentobarbital anesthesia were divided into two groups: (1) bacterial lipopolysaccharide (LPS) plus vehicle group (n = 5) receiving infusion of LPS (3 mg/kg/h for 1 h) followed by vehicle (2 mL/h for 5 hours); (2) LPS plus L-canavanine group (n = 6) receiving infusion of LPS (3 mg/kg/h for 1 hour) followed by L-canavanine (10 mg/kg/h for 5 hours).

RESULTS

LPS caused a significant (P < .05) decrease in mean arterial pressure (MAP) at 1 hour, but there was no significant difference in MAP during 6-hour period between the two groups. LPS alone did not cause significant changes in other hemodynamics, whereas L-canavanine caused a significant (P < .05) increase in pulmonary vascular resistance index (PVRI) and a decrease in oxygen delivery at 6 hours. The LPS-induced lactic acidosis and hypersecretion of ET-1 were aggravated after L-canavanine infusion. Plasma ET-1 showed positive correlations to lactate levels and PVRI, and negative correlations to cardiac output and oxygen delivery only in the LPS plus L-canavanine group, but not in the LPS plus vehicle group.

CONCLUSIONS

This study suggests that L-canavanine induces tissue hypoperfusion and ischemia with concomitant hypersecretion of ET-1 in dogs with endotoxic shock.

Role of endothelin-1/endothelin receptor system in endotoxic shock rats

Endothelin (ET)-1, a potent vasoconstrictor peptide derived from the endothelium, is markedly increased in endotoxic shock, although the pathophysiological role of ET-1 under septic conditions remains obscure. To delineate the role of ET-1 and its receptor subtype in endotoxic shock, we here attempted to determine the changes of circulating levels of ET-1 and its biosynthetic intermediate big ET-1 in endotoxic shock rats, to evaluate the gene expression of ET-1 as well as the ET-1 receptor subtypes (ETA and ETB) in the heart, lung and liver, and to study the effects of ET receptor antagonists on systemic arterial blood pressure, heart rate and survival rate. Administration of bacterial lipopolysaccharide (LPS) caused profound hypotension, increased heart rate and death, and these effects were blocked by a nonselective ETA/ETB receptor antagonist (TAK044), but not by an ETA selective antagonist (BQ123). Administration of exogenous ET-1 caused a profound pressor response in control rats, but not in the LPS-pretreated rats. Injection of LPS caused marked elevation of plasma levels of both ET-1 and big ET-1, which were not affected by treatment with either ET receptor antagonist. Administration of LPS caused up-regulation of ET-1 and ETB receptor mRNA in the heart, whereas ETA receptor mRNA was markedly down-regulated in the heart, lung and liver. These data suggest differential gene regulation of ET-1 and its receptor subtypes in various organs from endotoxic shock rats, and that nonselective ETA/ETB receptor antagonist, but not ETA receptor antagonist, ameliorates endotoxin-induced hypotension and death.

Modulation of neural activities during visual processing in the human extrastriate visual cortex

Magnetoencephalographic responses to single letters (Japanese monosyllabic characters) presented in the left visual field were measured during visual cognition tasks, in which subjects judged matching of characters in two different processes based on phonological and graphical cues. Equivalent current dipoles, which represent focal neural activities, were localized in the extrastriate visual cortex of the occipital to occipitotemporal regions. The main activities were observed in the right lateral area when the subjects detected shape, and also in the medial and inferior areas of both hemispheres when they detected rhyme. These results suggest that the neural activities in the extrastriate cortex, which are related to early processing of familiar visual forms, can be modified by the top-down control.

Unusual head-to-tail coupling of alkyl benzoates by electroreduction

The electroreduction of alkyl benzoates in an alcoholic solvent gave unusual head-to-tail coupled products. Usual head-to-head coupled products derived from acyloin condensation could not be detected. The best result (73% yield) was obtained from methyl benzoate using an undivided cell with an Sn cathode in i-PrOH containing tetraalkylammonium salt as a supporting electrolyte. Using an undivided cell, the products cross-coupled with a solvent molecule were obtained as byproducts. The substitution at the para position of methyl benzoate considerably decreased the yields of the head-to-tail coupled products and increased those of the cross-coupled products. The possible mechanism of the head-to-tail coupling is the attack of anion radical, generated from methyl benzoate by one-electron transfer, to another methyl benzoate. The cross-coupled products were formed by the reaction with carbonyl compound anodically produced from a solvent molecule. The cross-coupling between methyl benzoate and aromatic aldehydes was also effected by the mixed electroreduction under the same conditions.

Crucial role of type 1, but not type 3, inositol 1,4,5-trisphosphate (IP(3)) receptors in IP(3)-induced Ca(2+) release, capacitative Ca(2+) entry, and proliferation of A7r5 vascular smooth muscle cells

Stimulation of G protein- or tyrosine kinase-coupled receptors regulates cell proliferation through intracellular Ca(2+) ([Ca(2+)](i)) signaling. In A7r5 cells, we confirmed that inositol 1,4,5-trisphosphate (IP(3)) mediates vasopressin (VP)-evoked Ca(2+) release from intracellular stores and showed that types 1 (IP(3)R(1)) and 3 (IP(3)R(3)) IP(3) receptors were expressed. Using antisera selective for IP(3)R(1) or IP(3)R(3) and another that interacted equally well with both subtypes, together with membranes from SF:9 cells expressing only single IP(3)R subtypes to calibrate immunoblotting, we established that A7r5 cells express 81% IP(3)R(1) and 19% IP(3)R(3). To elucidate the contributions of IP(3)R(1) and IP(3)R(3) to Ca(2+) signaling and proliferation, stable clones expressing promoter-inducible antisense cDNA fragments (-90 to +9) corresponding to the two IP(3)R subtypes were selected. Mild inhibition of IP(3)R(1) (71+/-8% of control level) slightly attenuated the IP(3)-evoked Ca(2+) release (IICR) induced by VP but significantly decreased the subsequent capacitative Ca(2+) entry (CCE) and proliferation. Moderate inhibition (34+/-6%) strongly decreased both IICR and CCE and further blocked proliferation. Complete inhibition almost abolished IICR and CCE and arrested proliferation entirely. Complete inhibition of IP(3)R(3) expression slightly attenuated IICR without affecting CCE or proliferation. In cells microinjected with a low dose of heparin, VP-induced CCE was more susceptible than IICR to mild inhibition of both IP(3)R(1) and IP(3)R(3). A high dose of heparin had a similar effect to complete inhibition of IP(3)R(1) expression: it blocked VP-evoked IICR entirely and CCE by 90%. We conclude that IP(3)R(1), but not IP(3)R(3), is crucial for IICR, CCE, and proliferation of vascular smooth muscle cells.

Adrenomedullin stimulates proline-rich tyrosine kinase 2 in vascular smooth muscle cells

A novel vasodilator peptide, adrenomedullin (AM) stimulates extracellular signal-regulated kinase (ERK) 1/2 via yet uncharacterized 120 kDa tyrosine kinase(s) in rat vascular smooth muscle cells (VSMC). In the present study, we have examined whether the AM-activated tyrosine kinase is proline-rich tyrosine kinase 2 (PYK2) associable with adapter proteins. AM rapidly (within 30 sec) and dose dependently increased tyrosine kinase activity, whose effect was enhanced in the presence of o-vanadate, a phosphatase inhibitor. A tyrosine kinase with an apparent molecular mass of 120 kDa corresponding to that of PYK2 was predominantly localized to the cytosolic fraction, whereas the tyrosine-phosphorylated 180-kDa protein was observed in the membrane fraction from EGF-treated cells, but not from AM-treated cells. AM induced rapid (within 30 sec) and transient phosphorylation of PYK2, but not focal adhesion kinase. AM caused autophosphorylation of tyrosine residue(s) of PYK2 and promoted its association with adaptor proteins (Shc/Grb2). AM rapidly (within 1 min) activated c-Src and enhanced its association with tyrosine-phosphorylated PYK2. These data suggest that AM stimulates PYK2 which, in turn, activates c-Src and induces recruitment of adaptor proteins (Shc/Grb2), thereby leading to activation of p21(ras)/ERK1/2 cascade in VSMC.

Long-Term Survival and Late-Onset Complications of Cancer Patients Treated With High-Dose Chemotherapy Followed by Autologous Peripheral Blood Stem Cell Transplantation

The antitumor effect of high-dose chemotherapy (HDC) followed by autologous peripheral blood stem cell transplantation (auto-PBSCT) is considered superior to that of conventional chemotherapy. However, the long-term benefits of this strategy in Japan remain unclear. Therefore, in this study, 109 cancer patients enrolled between 1989 and 1999 were treated with HDC and auto-PBSCT. Patients were evaluated for long-term survival and late-onset complications, including secondary malignancy. The mean number of CD34+ cells harvested per apheresis was larger in the group receiving high-dose cytosine arabinoside or high-dose etoposide plus granulocyte colony-stimulating factor (G-CSF) than in the group receiving conventional chemotherapy plus G-CSF. The 5-year overall survival rates for non-Hodgkin's lymphoma patients in first complete remission (CR) (83.2%), second or subsequent CR (74.1%), or first partial remission (PR) (66.7%) at the time of transplantation were significantly higher than those with no remission (35.7%) at the time of transplantation (first CR, P < .05; second or subsequent CR, P < .05; first PR, P < .05). The 5-year overall survival (OS) rates for breast cancer was 40.8%, and the disease-free survival rate was extremely low (8.8%). The 5-year OS rates for chemotherapy-sensitive and chemotherapy-resistant diseases at the time of transplantation were 32.7% and 35.7%, respectively, a difference that was not considered significant. The 5-year OS for germ cell tumor was 80.0%, and the disease-free survival rate was 77.9%. The rate of therapy-related death was 8.2%. The occurrence rate of secondary malignancy was 0.9%. Late-onset complications were observed in 4 cases (glomerulonephritis, interstitial pneumonitis, ulcerative colitis, and acute myelogenous leukemia). At 3.7%, the occurrence rate was not very high, but most complications of auto-PBSCT were life threatening and interfered with patients' quality of life. A careful follow-up is required for at least 2 years after transplantation, because the mean occurrence time of late-onset complications is 16.7 months posttransplantation.

Transcriptional activation of the cyclin D1 gene is mediated by multiple cis-elements, including SP1 sites and a cAMP-responsive element in vascular endothelial cells

In an attempt to examine the mechanisms by which transcriptional activity of the cyclin D1 promoter is regulated in vascular endothelial cells (EC), we examined the cis-elements in the human cyclin D1 promoter, which are required for transcriptional activation of the gene. The results of luciferase assays showed that transcriptional activity of the cyclin D1 promoter was largely mediated by SP1 sites and a cAMP-responsive element (CRE). DNA binding activity at the SP1 sites, which was analyzed by electrophoretic mobility shift assays, was significantly increased in the early to mid G(1) phase, whereas DNA binding activity at CRE did not change significantly. Furthermore, Induction of the cyclin D1 promoter activity in the early to mid G(1) phase depended largely on the promoter fragment containing the SP1 sites, whereas the proximal fragment containing CRE but not the SP1 sites was constitutively active. Finally, the increase in DNA binding and promoter activities via the SP1 sites was mediated by the Ras-dependent pathway. The results suggested that the activation of the cyclin D1 gene in vascular ECs was regulated by a dual system; one was inducible in the G(1) phase, and the other was constitutively active.

Conservation of K1 immunoreactivity against early cortical neurones in the vertebrate telencephalon

A monoclonal antibody, K1, immunostains neurones generated earliest in the rat neocortex. The K1 immunoreactivity was found in both mouse and human embryos. In the human marginal zone, the subpial granular layer and the inner sublayer were stained at the 19th and 20th week of gestation, respectively. Western blot analysis revealed that the K1 immunoreactivity was conserved in a variety of vertebrates. While a protein of low molecular weight (200 kDa) reacted dominantly in an amphibian (Xenopus laevis) and a reptile (Agkistrodon blomhoffii), proteins of higher molecular weights (280 and 290 kDa) reacted dominantly in mammals (mouse, rat and macaque). In the brain of the reptile (Lacerta triliniata) embryo, K1 stained a marginal part of the superficial molecular layer in the dorsal cortex that is probably homologous to the mammalian marginal zone in the neocortex. In the chick embryo at the 8th day of incubation, the immunoreactivity was observed on neurones generated earliest in the dorsal cortex but not in the superficial molecular layer. The dorsal ventricular ridge and pallial thickening in either the reptile or chick were not stained. The K1 antigen could be a good marker for evolutional study of the mammalian neocortex.

Primary involvement of the motor area in association with the nigrostriatal pathway in multiple system atrophy: neuropathological and morphometric evaluations

To evaluate the changes that occur in the motor and supplementary motor cortices in cases of multiple system atrophy (MSA), we carried out morphological and morphometric studies in 7 cases of MSA and 11 age-matched controls. Neuropathological study revealed presence of glial cytoplasmic inclusions (GCIs) in the cortex and subcortical white matter of the motor and supplementary motor areas, loss of small to medium-sized pyramidal neurons, and astrocytosis in the motor cortex in all cases of MSA, showing a definite predilection in the cortical layers V and VI. The severity of neuronal loss in the motor cortex was highly correlated with the incidence of GCIs and the involvement of the nigrostriatal pathway. Morphometrically, significant reductions of both the thickness of motor cortical layers V and VI and the number of neurons were observed. In addition, a reduction in the number of neurons in the supplementary motor cortex was detected in three out of the seven MSA cases. The results of this study suggest that the motor area is a cardinal target in MSA, and that in association with the nigrostriatal pathway it forms a motor loop degeneration in this disease.

Oxidized low-density lipoprotein impairs the anti-coagulant function of tissue-factor-pathway inhibitor through oxidative modification by its high association and accelerated degradation in cultured human endothelial cells

We have examined whether oxidized low-density lipoprotein (ox-LDL) affects the function of tissue-factor-pathway inhibitor (TFPI), an anti-coagulant regulator in the extrinsic pathway of coagulation, in cultured human umbilical vein endothelial cells (HUVEC). Treatment of culture medium of HUVEC with ox-LDL, but not with native or acetylated LDLs, drastically decreased the reactivity of TFPI to its antibody specific for Kunitz domain 1 or one specific for the conformation between Kunitz 1 and 2 of TFPI, and caused a rapid, concentration-dependent decrease in the functional activity of TFPI to inhibit Factor X activation. When 5 ng of recombinant TFPI (rTFPI) was mixed with 10 microg of ox-LDL for 30 min, almost all of the rTFPI was detected in the ox-LDL fraction and no free rTFPI was observed on non-denaturing PAGE, in contrast with the virtual absence of rTFPI in the native LDL fraction. Ox-LDL decreased the antigen level of TFPI in the lysate of HUVEC in a time-dependent manner. It did not affect the mRNA level, but ox-LDL-dependent reduction of the TFPI antigen level in HUVEC was reversed by the simultaneous treatment of ox-LDL with bafilomycin A1, an inhibitor of the lysosomal proton pump. These results indicate that ox-LDL lessens the anti-coagulant function of TFPI through both oxidative modification and accelerated degradation of the molecule outside and inside HUVEC respectively.

A study on the structure-function relationship of lipopeptide biosurfactants

Arthrofactin (AF) and surfactin (SF) are the most effective cyclic lipopeptide biosurfactants ever reported. Linear AF and linear SF were prepared by saponification of lactone ring. The oil displacement activities decreased to one third of their respective original values. When residues of both an aspartic acid and a glutamic acid of SF were methylated or amidated, the activity increased by 20%, although their water solubility was lost. When these amino acid residues were modified by aminomethane sulfonic acid, the activity was drastically decreased probably owing to charge repulsion and structural distortion inhibiting micelle formation. Both AF and SF expressed higher activity under alkaline conditions than acidic conditions. AF was more resistant to acidic conditions than SF and it kept high activity even under pH 0.5. Although SF drastically reduced its activity under acidic conditions, surfactin-Asp/Glu-amido ester and surfactin-Asp/Glu-methyl ester retained similar activities irrespective of the pH change. A couple of conformers of SF prepared by reverse-phase HPLC showed the same oil displacement activity but different surface tension-reducing activity. AF was produced as a series of different fatty acid chain lengths (from C8 to C12). Among them, AF with fatty acid chain length of C10, which was the main product of the strain, showed the highest activity.

A mouse model of vascular injury that induces rapid onset of medial cell apoptosis followed by reproducible neointimal hyperplasia

Genetically modified mice serve as a powerful tool to determine the role of specific molecules in a wide variety of biological phenomena including vascular remodeling. Several models of arterial injury have been proposed to analyze transgenic/knock-out mice, but many questions have been raised about their reproducibility and physiological significance. Here, we report a new mouse model of vascular injury that resembles balloon-angioplasty. A straight spring wire was inserted into the femoral artery via arterioctomy in a small muscular branch. The wire was left in place for one minute to denude and dilate the artery. After the wire was removed, the muscular branch was tied off and the blood flow of the femoral artery was restored. The lumen was enlarged with rapid onset of medial cell apoptosis. While the circumference of the external elastic lamina remained enlarged, the lumen was gradually narrowed by neointimal hyperplasia composed of smooth muscle cells. At 4 weeks, a concentric and homogeneous neointimal lesion was formed reproducibly in the region where the wire had been inserted. Similar exuberant hyperplasia could be induced in all strains examined (C57BL/6J, C3H/HeJ, BALB/c, and 129/SVj). This model may be widely used to study the molecular mechanism of post-angioplasty restenosis at the genetic level.

[Vascular and metabolic reserve in a case of hypoplasia of bilateral internal carotid arteries]

We report a 64-year-old right-handed man who presented with a hypoplasia of bilateral internal carotid arteries (ICAs). The patient complained of a vertigo and was diagnosed as having a benign paroxysmal positional vertigo. Upon neurological examination, he was completely free from neurological deficits. MR angiogram revealed an occlusion of both ICAs. On conventional angiogram, the right ICA was occluded about 3 cm distal from its origin, and the left ICA was occluded at the precavernous portion. There was an abundant collateral blood flow to the frontal, temporal and parietal lobes through the posterior communicating arteries. Both carotid canals were hypoplastic on 3D-CT. The patient was then diagnosed as having a hypoplasia of both ICAs. Using a positron emission tomography (PET), cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), oxygen extraction fraction (OEF), and vascular transit time (VTT) were measured during resting state, and the vascular reactivities to carbon dioxide inhalation (VRCO2), and to the intravenous administration of Acetazolamide (VRACZ) were also evaluated. There was no global or focal reduction in CBF and VTT was within normal limit, whereas a global reduction of CMRO2 caused mild decrease in OEF. Moreover, VRACZ was significantly decreased and an intracerebral steal phenomenon was observed in the parietal cortical areas, whereas VRCO2 was preserved. The discrepancy between VRACZ and VRCO2 observed could be related to the differences in the mechanisms underlying the vasodilating effects of carbon dioxide and ACZ.

Suppression of integrin alpha(v) expression by endothelin-1 in vascular smooth muscle cells

Both integrins and endothelins (ETs) are known to play important roles in vascular remodeling via proliferation, apoptosis, and migration of vascular smooth muscle cells (VSMCs), whose dysfunctions have been implicated in the pathogenesis of end-organ damage associated with hypertension and arteriosclerosis. However, whether there is any interaction between endothelin-1 (ET-1) and integrins remains unknown. Therefore, the aim of the present study was to elucidate whether ET-1 regulates the expression of integrin alpha(v) in rat VSMCs. ET-1 dose- and time-dependently suppressed the integrin alpha(v) messenger RNA (mRNA) transcripts, as quantified by a real-time quantitative polymerase chain reaction (PCR) method, and decreased the transcriptional activity of integrin alpha(v) gene, as demonstrated by integrin alpha(v)-luciferase assay. The inhibitory effect of ET-1 on integrin alpha(v) gene expression was abrogated by an ETA receptor antagonist (BQ123) but not by an ET(B) receptor antagonist (BQ788). ET-1 also suppressed the cell surface expression of integrin alpha(v)beta5 and the adhesion to vitronectin, but not to fibronectin. These results demonstrate that the adhesion of vitronectin to rat VSMCs is inhibited by ET-1 via the ET(A) receptors by suppressing integrin alpha(v) gene transcription, suggesting that ET-1 is involved in regulation of vascular integrin alpha(v) gene expression.

Cytokine-activated p42/p44 MAP kinase is involved in inducible nitric oxide synthase gene expression independent from NF-kappaB activation in vascular smooth muscle cells

Recent evidence suggests the possible involvement of inducible nitric oxide synthase (iNOS) in the development and maintenance of hypertension in certain animal models. Inflammatory cytokines activate nuclear factor (NF)-kappaB, which plays a major role in transactivation of the inducible nitric oxide synthase (iNOS) gene. However, it remains unknown whether cytokine-mediated iNOS expression in vascular smooth muscle cells (VSMCs) requires signaling pathway(s) other than NF-kappaB activation. The purpose of this study was to determine whether the p42/p44 MAP kinase pathway is involved in cytokine-induced NF-kappaB activation and/or iNOS expression in cultured rat VSMCs. Nitrite/nitrate (NOx) production stimulated by interleukin (IL)-1beta or tumor necrosis factor (TNF)-alpha in VSMCs was markedly suppressed by inhibiting MAP kinase by pretreatment with a p42/p44 MAP kinase kinase (MAPKK)-1 inhibitor (PD98059) or by transfecting the dominant-interfering form of the nonphosphorylated MAPKK-1 expressing construct (MAPKK S222A). Inhibition of p42/p44 MAP kinase also antagonized the upregulation of iNOS mRNA and protein, as demonstrated by the quantitative RT-PCR method and Western blot analysis, respectively. Furthermore, rat iNOS promoter activity using an iNOS-luciferase construct stimulated by cytokines was inhibited by MAPKK-1 inhibition. However, kappaB-dependent transcription analysis revealed that cytokine-stimulated NF-kappaB activity was unaffected by MAP kinase inhibition. Western blot analysis using anti-IkappaB-alpha and anti-phospho-IkappaB-alpha antibodies showed that PD98059 had no effect on transient phosphorylation or degradation of IkappaB-alpha by cytokines. An electrophoretic mobility shift assay using synthetic oligonucleotide corresponding to the downstream NF-kappaB site of rat iNOS promoter as a probe showed that MAP kinase inhibition did not block cytokine-stimulated activation of NF-kappaB. These data suggest that the MAP kinase pathway is in part involved in cytokine-induced iNOS expression independent from NF-kappaB activation in rat VSMCs.

Solitary osseous hemangioma outside the spinal and craniofacial bones

Bone hemangioma is mainly seen in the skull and spine, and rarely occurs in other bones. We report herein four cases of osseous hemangioma arising in rare sites: In two cases, on a rib; a faintly painful mass in one case located on the scapula; and progressive pain in one case located on the ischium. The tumors presented clinically as incidental lesions on radiographs. All cases had an aggressive appearance, such as defect of the cortex, a soft-tissue mass, and a sunburst-like appearance. Markedly high signal intensity on T2-weighted magnetic resonance images was a characteristic finding. Open biopsy resulted in severe blood loss, but needle biopsy was performed safely under computed tomography guidance. It is important to note that bone hemangiomas may be misdiagnosed as malignant tumors.

Cyclin A downregulation and p21(cip1) upregulation correlate with GATA-6-induced growth arrest in glomerular mesangial cells

The GATA-6 transcription factor is reported to be expressed in vascular myocytes. Because glomerular mesangial cells (GMCs) and vascular myocytes have similar properties, we examined whether GATA-6 was expressed in cultured GMCs and whether overexpression of GATA-6 induced cell cycle arrest in GMCs, using a recombinant adenovirus that expresses GATA-6 (Ad GATA-6). GATA-6 expression in GMCs was downregulated when quiescent GMCs were stimulated by serum to reenter the cell cycle. [(3)H]thymidine uptake was inhibited in GMCs infected with Ad GATA-6 in a dose- and time-dependent manner. The expression of cyclin A protein was decreased and that of the cyclin-dependent kinase inhibitor p21(cip1) was increased in GMCs infected with Ad GATA-6. Although the expression of p21(cip1) transcripts did not change remarkably, p21(cip1) protein was stabilized in GMCs infected with Ad GATA-6, suggesting a post-transcriptional regulation of p21(cip1) expression. Northern blot analysis showed that expression of the cyclin A transcript was decreased in Ad GATA-6-infected cells, whereas this decrease of cyclin A was not observed in GMCs derived from p21(cip1) null mice. Our results demonstrate that GATA-6 is endogenously expressed in GMCs and that overexpression of GATA-6 can induce cell cycle arrest. Our results also show that GATA-6-induced cell cycle arrest is associated with inhibition of cyclin A expression and p21(cip1) upregulation. Finally, our results indicate that the GATA-6-induced suppression of cyclin A expression depends on the presence of p21(cip1).

Secretion of adrenomedullin by renal tubular cell lines

Adrenomedullin (AM) is a novel and potent vasodilator peptide originally isolated from human pheochromocytoma. The present study was designed to study whether AM is produced by and secreted from renal tubular cell lines and whether arginine vasopressin (AVP) affects AM secretion from these cell lines. Three renal tubular cell lines derived from different species (LLCPK1, MDCK, and MDBK) secrete AM-like immunoreactivity (AM-LI) into culture medium, the immunological and physicochemical properties of which are similar to that of synthetic human AM as evaluated by reverse-phase high-performance liquid chromatography. Among the three cell lines, AVP in combination with a phosphodiesterase inhibitor (isobutylmethylxanthine) stimulated AM-LI secretion most potently from MDCK cells in a time- and dose-dependent manner. In MDCK cells, a V2 receptor agonist (deamino-D-Arg8-vasopressin) dose-dependently stimulated AM-LI secretion in the same manner as AVP. Furthermore, the AVP-induced AM-LI secretion was blocked by a V2 receptor antagonist (OPC31260), but not by a V1 receptor antagonist (OPC21268). These data indicate that AM is secreted from renal tubular cell lines and that AVP stimulates AM secretion via V2 receptors, suggesting its autocrine/paracrine role in renal function.

Analysis of the discharge pattern of floccular Purkinje cells in relation to vertical head and eye movement in the squirrel monkey

Purkinje (P) neurons are highly irregular in their discharge patterns having a high coefficient of variation. We have developed a method to extract the signal from these noisy neurons employing multiple linear regression against the input signals that are causal in P-cell firing, namely retinal slip, head motion parameters, and the efference copy of the oculomotor commands. This method was shown to extract all of the experimental stimulus-related signal as the residual following extraction had the same amplitude distribution and spectral content as those of the spontaneous discharge of P-cells when no external stimuli were applied. The method enables us to decompose P-cell firing modulation into components mediated by mossy fiber inputs to flocculus, that is, retinal slip, vestibular and oculomotor efference copy signals. By evaluating these components in relation to VOR adaptation, one can argue that one role of the flocculus is in converting these sensory and efference copy input signals into eye movement-related signals in conjunction with VOR motor learning.

Immunotoxicity of N,N-diethylaniline in mice: effect on natural killer activity, cytotoxic T lymphocyte activity, lymphocyte proliferation response and cellular components of the spleen

We previously found that N,N-diethylaniline increased the frequency of sister chromatid exchange (SCE) of human lymphocytes to about five times that of the control value, and was as toxic as cyclophosphamide used as a positive control for SCE. To explore whether N,N-diethylaniline affects the function of lymphocytes, we evaluated its immunotoxicity using CBA/N mice. The mice were divided into four groups and received 0, 100, 200, or 400 mg/kg body weight of N,N-diethylaniline by subcutaneous injection. The following items were investigated on days 3 and 7 after injection: body weight, weight of spleen, number of splenocytes, natural killer (NK) and cytotoxic T lymphocyte (CTL) activities, and concanavalin A (Con A)- and lipopolysaccharide (LPS)-stimulated lymphocyte proliferation using splenocytes. The following splenocyte phenotypes were also quantified by flow cytometry: (1) B cells; (2) total T cells; (3) CD4(+) and CD8(+) T cells; (4) NK; (5) macrophages and (6) nucleated erythrocytes. The splenic NK and CTL activities in exposed groups significantly decreased compared to the control in a dose-dependent manner and lymphocytes from the 200 and 400 mg/kg groups showed significantly higher spontaneous proliferation. The weight of the spleen and number of splenocytes were significantly higher in exposed groups than in the control. N,N-Diethylaniline also increased the percentages of macrophages, nucleated erythrocytes and B cells in the spleen. On the other hand, N,N-diethylaniline did not affect LPS-stimulated B cell and Con A-stimulated T cell proliferation, or the percentages of NK, total T, and CD4(+) and CD8(+) T cells in the spleen or the body weight of mice. The above findings indicated that N,N-diethylaniline selectively inhibited splenic NK and CTL activity and this inhibition was due to decreased NK and CTL functions, but not due to changes in the numbers of splenic NK and T cells.

Effects of vasodilatory antihypertensive agents on endothelial dysfunction in rats with ischemic acute renal failure

Ischemic acute renal failure is associated with vascular endothelial dysfunction. We examined whether vasodilatory antihypertensive agents would improve endothelial function in rats with ischemia/reperfusion renal injury. Rat kidneys were isolated and perfused after clipping of the bilateral renal arteries for 45 min and reperfusion for 24 h, and renal perfusion pressure and nitric oxide concentration in the venous effluent (chemiluminescence assay) were monitored. Preischemic administration of celiprolol (a beta-blocker; 100 mg/kg p.o.), benidipine (a calcium channel blocker; 1 mg/kg p.o.), or imidapril (an angiotensin converting-enzyme inhibitor; 3 mg/kg p.o.) restored endothelial function in rats subjected to acute renal ischemia (deltarenal perfusion pressure [10(-8) M acetylcholine]: sham -42+/-3%, ischemia -31+/-1%, ischemia +celiprolol -39+/-1%*, ischemia+benidipine -38+/-2%*, ischemia+imidapril -42+/-2%*; *p<0.05 vs. ischemia). Serum urea nitrogen and creatinine levels were also lower in the treated groups. Furthermore, ischemia-induced decreases in the response to acetylcholine and renal excretory function were smaller in SHR than in deoxycorticosterone-salt hypertensive rats, in which endothelial damage was marked. These results suggest that preischemic endothelial function may influence the degree of ischemic renal injury. Calcium channel blockers, converting-enzyme inhibitors, and endothelial NO synthase-activating beta-blockers had beneficial effects on renovascular endothelial dysfunction due to ischemia.

Yeast glycogen synthase kinase 3 is involved in protein degradation in cooperation with Bul1, Bul2, and Rsp5

The yeast Saccharomyces cerevisiae has four genes, MCK1, MDS1 (RIM11), MRK1, and YOL128c, that encode glycogen synthase kinase 3 (GSK-3) homologs. The gsk-3 null mutant, in which these four genes are disrupted, shows temperature sensitivity, which is suppressed by the expression of mammalian GSK-3beta and by an osmotic stabilizer. Suppression of temperature sensitivity by an osmotic stabilizer is also observed in the bul1 bul2 double null mutant, and the temperature sensitivity of the bul1 bul2 double null mutant is suppressed by multiple copies of MCK1. We have screened rog mutants (revertants of gsk-3) which suppress the temperature sensitivity of the mck1 mds1 double null mutant and found that two of them, rog1 and rog2, also suppress the temperature sensitivity of the bul1 bul2 double null mutant. Bul1 and Bul2 have been reported to bind to Rsp5, a hect (for homologous to E6-associated-protein carboxyl terminus)-type ubiquitin ligase, but involvement of Bul1 and Bul2 in protein degradation has not been demonstrated. We find that Rog1, but not Rog2, is stabilized in the gsk-3 null and the bul1 bul2 double null mutants. Rog1 binds directly to Rsp5, and their interaction is dependent on GSK-3. Furthermore, Rog1 is stabilized in the npi1 mutant, in which RSP5 expression levels are reduced. These results suggest that yeast GSK-3 regulates the stability of Rog1 in cooperation with Bul1, Bul2, and Rsp5.

Auditory cortex responds in 100 ms to incongruity of melody

In order to find the cortical neural activities that reflect musical processing, we conducted measurements of MEG responses while subjects listened to familiar melodies. Significant enlargement of the N1m peak was observed in the response to the endnote of a phrase that was deviated to out-of-key from the keynote. Equivalent current sources of the enlarged N1m response were localized in the cortical area of the superior temporal plane. These results suggest the possibility of fast neural processing, as early as 100 ms, of the auditory cortex detecting incongruity of a melody.

Thymic hyperplasia as a source of ectopic ACTH production

A 26 year-old man with suspected Cushing's disease underwent transsphenoidal exploration of the pituitary without any evidence of microadenoma or hyperplasia. Progressive hypercortisolism necessitated bilateral adrenalectomy. Postoperatively, skin pigmentation gradually developed with a marked elevation of plasma ACTH levels, and CT scanning uncovered a thymic mass. Following removal of the thymic mass, skin pigmentation disappeared and plasma ACTH levels fell to normal. The excised mass was found to be a benign thymic hyperplasia without epithelial or carcinoid tumor cells. However, gel chromatography showed that the thymic tissue extract contained high ACTH content comparable to that of ectopic ACTH-producing tumors with a major component corresponding to ACTH(1-39). Northern blot analysis and in situ hybridization revealed the expression of proopiomelanocortin transcripts in lymphocytes of thymic hyperplasia. This report suggests that lymphocytes in thymic hyperplasia are the most likely site of deregulated ACTH expression causing ectopic ACTH syndrome.

H. pylori activates NF-kappaB through a signaling pathway involving IkappaB kinases, NF-kappaB-inducing kinase, TRAF2, and TRAF6 in gastric cancer cells

BACKGROUND & AIMS

H. pylori infection on gastric epithelial cells has been shown to induce NF-kappaB activation, but the mechanism of intracellular signal conduction that leads to NF-kappaB activation is not clear. The aim of this study was to analyze the molecular mechanism responsible for H. pylori-mediated NF-kappaB activation on gastric cancer cells.

METHODS

NF-kappaB activation by H. pylori was tested by using luciferase reporter assay. IkappaBalpha degradation by H. pylori infection was assessed by immunoblotting. IKKalpha and IKKbeta activation was analyzed by kinase assay. In transfection experiments, effects of dominant negative IkappaBalpha, IKKalpha, IKKbeta, NF-kappaB-inducing kinase (NIK), TRAF2, and TRAF6 mutants were investigated. The effects of an IKKbeta-specific inhibitor, aspirin, on NF-kappaB activation and IL-8 secretion were also analyzed.

RESULTS

H. pylori promotes degradation of IkappaBalpha, a cytoplasmic inhibitor of NF-kappaB. In kinase assay, H. pylori induced IKKalpha and IKKbeta catalytic activity in gastric cancer cells. Transfection of kinase-deficient mutant of either IKK inhibited H. pylori-mediated NF-kappaB activation dose-dependently. Aspirin inhibited both NF-kappaB activation and IL-8 secretion induced by H. pylori. NF-kappaB activation was also inhibited by transfection of kinase-deficient NIK or a dominant negative mutant of upstream adapter protein TRAF2 or TRAF6.

CONCLUSIONS

H. pylori induces NF-kappaB activation through an intracellular signaling pathway that involves IKKalpha, IKKbeta, NIK, TRAF2, and TRAF6.

Established histological identity and cell destruction treatments for cancer

During cancerous cell turnover activity maintained by two types of mitosis, maturation and heteroduplication, cancer tissue consists of two types of cells, maturable and non-maturable. Most of the tissue is composed of maturable cells, which eventually disappear in the terminally matured cell phase. These cells do not participate in cell turnover activity or the organoid identity of cancer tissue. However, a small portion of the tissue is comprised of non-maturable cells, which replicate themselves endlessly, while producing maturable cells through each mitotic division in hetero-duplication mitosis. Thus, cell turnover activity and organoid identity are established in the cancer tissue. This organoid identity is solely responsible for carcinogenesis. Since most typical features of cancer are only detectable in maturable cells during maturation mitosis, cell destruction targeting these features should not be regarded as eradication. To eradicate cancer, the organoid identity of cancer, which is only established by heteroduplication mitosis, should clearly be recognized, and a new concept of cancer treatment based on destruction of the organoid identity should be devised in the future. This does not appear to be an insurmountable task.

Adrenomedullin and nitric oxide inhibit human endothelial cell apoptosis via a cyclic GMP-independent mechanism

Adrenomedullin, which was discovered as a vasodilating peptide, has been reported to be produced in various organs, in which adrenomedullin regulates not only vascular tone but also cell proliferation and differentiation in an autocrine/paracrine manner. We evaluated the effect of adrenomedullin on endothelial cell apoptosis. Human umbilical vein endothelial cells underwent apoptosis when cultured in serum-free medium. Treatment with adrenomedullin reduced the number of cells with pyknotic nuclei (Hoechst 33258 staining) and inhibited cell death (dimethylthiazol-diphenyltetrazolium bromide assay) in a dose-dependent manner. The administration of adrenomedullin did not alter the expression levels of Bcl-2 family proteins. Experiments with analogs of cAMP or a cAMP-elevating agonist demonstrated that elevation of the intracellular cAMP concentration does not mediate the antiapoptotic effect of adrenomedullin. The coadministration of N-nitro-L-arginine methyl ester (2 mmol/L), an inhibitor of nitric oxide synthase, abrogated the effect of adrenomedullin. Lower doses of sodium nitroprusside (1 to 10 micromol/L), a nitric oxide donor, mimicked the antiapoptotic effect of adrenomedullin. The antiapoptotic effect of sodium nitroprusside was not attenuated by the inhibition of soluble guanylyl cyclase with 1 micromol/L oxadiazolo-quinoxalin-1-one nor could apoptosis be inhibited by the incubation of human umbilical vein endothelial cells with 1 mmol/L 8-bromo-cGMP, a cell-permeant cGMP analog. These results indicate that adrenomedullin and nitric oxide inhibit endothelial cell apoptosis via a cGMP-independent mechanism.

Well-differentiated liposarcoma of the hand. Case report

Malignant lipomatous tumours of the hands are extremely rare. A 62-year-old man complained of an enlarging, soft, painless mass in his left hand. Magnetic resonance imaging showed a fatty tumour with irregular septa, and an incisional biopsy showed it to be a well-differentiated liposarcoma. The tumour was resected en bloc and he had a course of external beam radiotherapy. Apart from a slight reduction in grip strength he was well 15 months later with no sign of recurrence.

Identification of a 97-kDa mastoparan-binding protein involving in Ca(2+) release from skeletal muscle sarcoplasmic reticulum

Mastoparan (MP) and radiolabeled [Tyr(3)]MP caused a transient Ca(2+) release from the heavy fraction of sarcoplasmic reticulum, which was inhibited by ryanodine. MP enhanced [(3)H]ryanodine binding in a concentration-dependent manner with an EC(50) value of approximately 0.3 microM. The (45)Ca(2+) release was accelerated by MP, [Tyr(3)]MP, or caffeine in a concentration-dependent manner. The EC(50) values for MP, [Tyr(3)]MP, and caffeine were approximately 2. 0 microM, 7.7 microM, and 1.8 mM, respectively. MP, like caffeine, shifted the stimulatory limb of a bell-shaped curve of Ca(2+) dependence to the left. (45)Ca(2+) release induced by caffeine was completely inhibited by typical blockers of Ca(2+)-induced Ca(2+) release, such as Mg(2+), ruthenium red, or procaine. However, (45)Ca(2+) release induced by MP was completely inhibited by Mg(2+), but it was only partially inhibited by ruthenium red or procaine. The rate of (45)Ca(2+) release induced by MP was further increased in the presence of caffeine, showing that the MP binding site is different from that of caffeine on Ca(2+) release channels. We succeeded in the synthesis of (125)I-[Tyr(3)]MP with a high specific activity. (125)I-[Tyr(3)]MP bound specifically to heavy fraction of sarcoplasmic reticulum with a K(d) value of 4.0 microM and a B(max) value of 3.0 nmol/mg. Furthermore, (125)I-[Tyr(3)]MP specifically cross-linked to the 97-kDa protein without direct binding to ryanodine receptor. The protein was not triadin or Ca(2+)-pump, because antitriadin antibody and anti-Ca(2+)-pump antibody did not immunoprecipitate the protein. These results suggest that the 97-kDa MP-binding protein may have an important role in the excitation-contraction coupling of skeletal muscle.

Immunoreactive adrenomedullin (AM) concentration in maternal plasma during human pregnancy and AM expression in placenta

Adrenomedullin (AM) is a novel vasorelaxant peptide, isolated from human pheochromocytoma. Although AM may be involved in the regulation of the cardiovascular system, a number of other mechanisms are also involved. The present study was undertaken to confirm the presence of AM in human maternal circulation and in placental function during pregnancy. Immunoreactive (ir) AM concentrations in maternal plasma were 3.4+/-0.7fmol/ml (mean+/-s.e. m.) in the first trimester, 3.3+/-1.1fmol/ml in the second trimester, 7.3+/-2.8fmol/ml in the third trimester, 4.1+/-1.9fmol/ml in early puerperium and 3.0+/-0.4fmol/ml in non-pregnant periods; the concentration in the third trimester was significantly greater than those in other periods. Plasma concentrations of estradiol (E(2)), progesterone, human placental lactogen (hPL) and human chorionic gonadotropin (hCG) were also measured, using RIA kits. Significant correlations have been demonstrated between the concentrations of irAM and those of E(2), progesterone and hPL. We therefore examined the expression of AM within the placental tissues using immunohistochemistry and northern blot analysis in order to demonstrate a correlation between the presence of AM in the placenta and maternal plasma. Using immunohistochemistry, we detected AM in the amnion at term and the expression of AM mRNA in human placental tissues using cloned human (h) AM complementary DNA as a probe. This study demonstrates the immunoreactivity of human hAM in maternal plasma during pregnancy, and suggests that hAM in maternal plasma is generated partly from placental tissue.

Pontine atrophy in spinocerebellar ataxia type 6

To investigate the clinical range of spinocerebellar ataxia type 6 (SCA6), we screened CAG repeat expansion in the voltage-dependent alpha 1A calcium channel gene (CACNL1A4) in 71 ataxic patients in 60 families; 54 patients in 43 families with hereditary ataxia and 17 sporadic patients. Thirteen patients with SCA6 were detected to have elongated CAG in CACNL1A4. Of these, 7 patients had been diagnosed as having hereditary cerebellar cortical atrophy, and 6 patients had been found to have sporadic occurrence. One patient showed distinct pontine atrophy with prominent horizontal or oblique gaze nystagmus which is an unusual feature in sporadic olivopontocerebellar atrophy. For the efficient screening of SCA6, we would propose testing CAG repeat expansion in CACNL1A4, in patients with one of two markers: (1) horizontal or oblique gaze nystagmus without other eye movement disorders, (2) pure cerebellar atrophy, even if occurrence is sporadic. We should note that the pontine atrophy could also be caused by CAG repeat expansion in CACNL1A4.

The by-products generated during sarin synthesis in the Tokyo sarin disaster induced inhibition of natural killer and cytotoxic T lymphocyte activity

More than 5000 passengers on Tokyo subway trains were injured by the nerve gas, sarin and its by-products. Analysis of phosphor-carrying metabolites of sarin and its by-products in urine samples from the victims suggested that they were exposed not only to sarin, but also by-products generated during sarin synthesis, i.e. diisopropyl methylphosphonate (DIMP) and diethyl methylphosphonate (DEMP). We suspected genetic after-effects due to sarin by-products, thus, we checked the frequency of sister chromatid exchange (SCE) and found that SCE was significantly higher in the victims than in a control group, and that DIMP and DEMP significantly induced human lymphocyte SCE in vitro. In the present study, to explore whether DIMP and DEMP, which induced a high frequency of SCE of lymphocytes, also affected the lymphocyte functions, we examined the effect of DIMP and DEMP on splenic natural killer (NK) and splenic cytotoxic T lymphocyte (CTL) activity in mice, and NK activity of human lymphocytes in vitro. We found that DIMP and DEMP significantly inhibited NK and CTL activity in a dose-dependent manner. The inhibition induced by DIMP was stronger than that by DEMP. The effect of DIMP and DEMP on the splenic NK activity of mice was stronger than on the splenic CTL activity, and the human lymphocytes is more sensitive to DIMP and DEMP than the splenocytes of mice.

Apraxia of lid opening is alleviated by pallidal stimulation in a patient with Parkinson's disease

Apraxia of lid opening (ALO) is a syndrome characterized by a non-paralytic inability to open the eyes at will in the absence of visible contraction of the orbicularis oculi muscle. Here we report that globus pallidus internus deep brain stimulation on the right side markedly alleviates ALO as well as gait freezing in a patient with Parkinson's disease.

[Study of matrix metalloproteinase-2 and -9 in thyroid papillary cancer]

Metastasis of cancer starts with the penetration of cancer cells through the membrane surrounding the cancer focus into the stroma (extracellular matrix). The focal membrane consists of mainly type-IV collagen. An immunochemical study of 28 patients with benign thyroid nodular diseases and 27 patients with papillary carcinoma revealed the fragmentation of type-IV collagen in 4 patients with papillary carcinoma. Matrix metalloprotease (MMP)-2 and MMP-9 are the major enzymes which decompose type-IV collagen, and they have been suggested to be related to cancer metastasis. Therefore, we conducted biochemical and immunohistochemical studies to determine the relationship between these MMPs and the degree of malignancy in thyroid diseases. The concentration of MMP-2 in the serum of patients with papillary carcinoma and patients with benign nodules was 526.0 +/- 96.6 and 522.7 +/- 114.6 ng/ml, respectively, and that of MMP-9 was 53.8 +/- 40.3 and 39.9 +/- 36.0 respectively. There was no significant difference between the two groups in the concentration of either enzyme. The concentration of TIMP-2 in the serum was below the detectable level. On the other hand, the concentration of MMP-2 in the tissue of papillary carcinoma, benign nodules and normal tissue was 12.1 +/- 8.1, 5.7 +/- 4.3, and 0.6 +/- 0.5 ng/mg tissue protein, respectively, and that of MMP-9 was 4.2 +/- 4.1, 2.1 +/- 1.7, and 0.4 +/- 0.3 ng/mg tissue protein, respectively. Concentrations of both enzymes were significantly higher in the papillary carcinoma tissue. Immunohistochemical studies revealed a diffuse granular distribution of MMP-2 in the cytoplasm of the tumor cells. These findings imply that MMP-2 and MMP-9 are related to the degree of malignancy of cancer, especially metastasis.

Can PET data differentiate Alzheimer's disease from vascular dementia?

The present study endeavored to differentiate Alzheimer's disease (AD) from vascular dementia (VaD) by comparing the metabolic and hemodynamic parameters. Positron emission tomographic (PET) studies were carried out in 13 patients with probable AD and 20 patients with VaD. PET findings were not included in the diagnostic criteria of AD or VaD. Using oxygen-15 labeled compounds, cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF), cerebral blood volume, and vascular transit time (VTT) were measured quantitatively during the resting state. To evaluate vascular reactivity (VR), CBF was also measured during 7% CO2 inhalation. Regional CBF from the parietal cortex positively correlated with the neuropsychological scores in both AD and VaD groups. The typical parietotemporal pattern of hypoperfusion and hypometabolism was observed in the AD group, whereas the frontal lobe including the cingulate and superior frontal gyri were predominantly affected in the VaD group. The occipital cortex was preserved in both groups. A significant increase of the OEF was found in the parietotemporal areas in the AD group. No significant prolongation was seen with VTT. There was a marked difference in VR between the two groups: VR was depleted in the VaD group, whereas VR was normal in the AD group. The increased OEF with preserved vascular reserve seen in AD may implicate participation of a vascular factor in the pathogenesis of AD, possibly at the capillary level. Thus, PET provides important functional information in discriminating AD from VaD by comparing the patterns of hypoperfusion and/or hypometabolism, and in the understanding of the underlying hemodynamic pathophysiology.