Activin signaling as an emerging target for therapeutic interventions

After the initial discovery of activins as important regulators of reproduction, novel and diverse roles have been unraveled for them. Activins are expressed in various tissues and have a broad range of activities including the regulation of gonadal function, hormonal homeostasis, growth and differentiation of musculoskeletal tissues, regulation of growth and metastasis of cancer cells, proliferation and differentiation of embryonic stem cells, and even higher brain functions. Activins signal through a combination of type I and II transmembrane serine/threonine kinase receptors. Activin receptors are shared by multiple transforming growth factor-β (TGF-β) ligands such as myostatin, growth and differentiation factor-11 and nodal. Thus, although the activity of each ligand is distinct, they are also redundant, both physiologically and pathologically in vivo. Activin receptors activated by ligands phosphorylate the receptor-regulated Smads for TGF-β, Smad2 and 3. The Smad proteins then undergo multimerization with the co-mediator Smad4, and translocate into the nucleus to regulate the transcription of target genes in cooperation with nuclear cofactors. Signaling through receptors and Smads is controlled by multiple mechanisms including phosphorylation and other posttranslational modifications such as sumoylation, which affect potein localization, stability and transcriptional activity. Non-Smad signaling also plays an important role in activin signaling. Extracellularly, follistatin and related proteins bind to activins and related TGF-β ligands, and control the signaling and availability of ligands.

The functions of activins through activin receptors are pleiotrophic, cell type-specific and contextual, and they are involved in the etiology and pathogenesis of a variety of diseases. Accordingly, activin signaling may be a target for therapeutic interventions. In this review, we summarize the current knowledge on activin signaling and discuss the potential roles of this pathway as a molecular target of therapy for metabolic diseases, musculoskeletal disorders, cancers and neural damages.

Haptic localizations for onset and offset of vibro-tactile stimuli are dissociated

When humans explore the external world, hand and arm movements play important roles. Spatio-temporal arrangements of the environment are perceptually generated mainly by means of the sensory-motor integration of the internal model of these movements with the information obtained during the movements. In order to investigate the mechanisms of this integration process, localization tasks have been studied, and previous studies have suggested that the integration process does not work properly around the time of a hand movement. In particular, when a transient vibro-tactile stimulation is presented before, during, or after a hand movement, the stimulus is systematically mislocalized. However, it is debatable whether the tendency to mislocalize a transient stimulus indicates a general failure of the sensory-motor integration process. Here we investigated the generality of the tendency towards mislocalization by observing haptic localizations to different target types, the onset and offset of continuous vibro-tactile stimuli. We found similar types of mislocalizations in responses to the transient vibration and the onset of a continuous vibration, and a clear difference in the types of mislocalizations in responses to the onset and offset of continuous vibrations.

Signal transduction pathway through activin receptors as a therapeutic target of musculoskeletal diseases and cancer

Activin, myostatin and other members of the TGF-beta superfamily signal through a combination of type II and type I receptors, both of which are transmembrane serine/threonine kinases. Activin type II receptors, ActRIIA and ActRIIB, are primary ligand binding receptors for activins, nodal, myostatin and GDF11. ActRIIs also bind a subset of bone morphogenetic proteins (BMPs). Type I receptors that form complexes with ActRIIs are dependent on ligands. In the case of activins and nodal, activin receptor-like kinases 4 and 7 (ALK4 and ALK7) are the authentic type I receptors. Myostatin and GDF11 utilize ALK5, although ALK4 could also be activated by these growth factors. ALK4, 5 and 7 are structurally and functionally similar and activate receptor-regulated Smads for TGF-beta, Smad2 and 3. BMPs signal through a combination of three type II receptors, BMPRII, ActRIIA, and ActRIIB and four type I receptors, ALK1, 2, 3, and 6. BMPs activate BMP-specific Smads, Smad1, 5 and 8. Smad proteins undergo multimerization with co-mediator Smad, Smad4, and translocated into the nucleus to regulate the transcription of target genes in cooperation with nuclear cofactors. The signal transduction pathway through activin type II receptors, ActRIIA and ActRIIB, with type I receptors is involved in various human diseases. In this review, we discuss the role of signaling through activin receptors as therapeutic targets of intractable neuromuscular diseases, endocrine disorders and cancers.

Characterization of follistatin-related gene as a negative regulatory factor for activin family members during mouse heart development

Follistatin-related gene (FLRG) encodes a secretory glycoprotein that has characteristic cysteine-rich follistatin domains. FLRG protein binds to and neutralizes several transforming growth factor-beta (TGF-beta) superfamily members, including myostatin (MSTN), which is a potent negative regulator of skeletal muscle mass. We have previously reported that FLRG was abundantly expressed in fetal and adult mouse heart. In this study, we analyzed the expression of FLRG mRNA during mouse heart development. FLRG mRNA was continuously expressed in the embryonic heart, whereas it was very low in skeletal muscles. By contrast, MSTN mRNA was highly expressed in embryonic skeletal muscles, whereas the expression of MSTN mRNA was rather low in the heart. In situ hybridization and immunohistochemical analysis revealed that FLRG expressed in smooth muscle of the aorta and pulmonary artery, valve leaflets of mitral and tricuspid valves, and cardiac muscles in the ventricle of mouse embryonic heart. However, MSTN was expressed in very limited areas, such as valve leaflets of pulmonary and aortic valves, the top of the ventricular and atrial septa. Interestingly, the expression of MSTN was complementary to that of FLRG, especially in the valvular apparatus. Biochemical analyses with surface plasmon resonance biosensor and reporter assays demonstrated that FLRG hardly dissociates from MSTN and activin once it bound to them, and efficiently inhibits these activities. Our results suggest that FLRG could function as a negative regulator of activin family members including MSTN during heart development.

Transgenic expression of a myostatin inhibitor derived from follistatin increases skeletal muscle mass and ameliorates dystrophic pathology in mdx mice

Myostatin is a potent negative regulator of skeletal muscle growth. Therefore, myostatin inhibition offers a novel therapeutic strategy for muscular dystrophy by restoring skeletal muscle mass and suppressing the progression of muscle degeneration. The known myostatin inhibitors include myostatin propeptide, follistatin, follistatin-related proteins, and myostatin antibodies. Although follistatin shows potent myostatin-inhibiting activities, it also acts as an efficient inhibitor of activins. Because activins are involved in multiple functions in various organs, their blockade by follistatin would affect multiple tissues other than skeletal muscles. In the present study, we report the characterization of a myostatin inhibitor derived from follistatin, which does not affect activin signaling. The dissociation constants (K(d)) of follistatin to activin and myostatin are 1.72 nM and 12.3 nM, respectively. By contrast, the dissociation constants (K(d)) of a follistatin-derived myostatin inhibitor, designated FS I-I, to activin and myostatin are 64.3 microM and 46.8 nM, respectively. Transgenic mice expressing FS I-I, under the control of a skeletal muscle-specific promoter showed increased skeletal muscle mass and strength. Hyperplasia and hypertrophy were both observed. We crossed FS I-I transgenic mice with mdx mice, a model for Duchenne muscular dystrophy. Notably, the skeletal muscles in the mdx/FS I-I mice showed enlargement and reduced cell infiltration. Muscle strength is also recovered in the mdx/FS I-I mice. These results indicate that myostatin blockade by FS I-I has a therapeutic potential for muscular dystrophy.

Epidermal keratinocytes as the forefront of the sensory system

Various sensors that respond to physical or chemical environmental factors have been identified in the peripheral nervous system. Some of them, which respond to mechanical stress, osmotic pressure, temperature and chemical stimuli (such as pH), are also expressed in epidermal keratinocytes. Neurotransmitters and their receptors, as well as receptors that regulate the neuroendocrine system of the skin, are also present in keratinocytes. Thus, broadly speaking, epidermal keratinocytes appear to be equipped with sensing systems similar to those of the peripheral and central nervous systems. It had long been considered that only nerve C-terminals in the epidermis play a role in skin surface perception. However, building on earlier work on skin receptors and new findings introduced here, we present in this review a novel hypothesis of skin sensory perception, i.e. first, keratinocytes recognize various environmental factors, and then the information is processed and conveyed to the nervous system.

ALK7 is a novel marker for adipocyte differentiation

Transforming growth factor-beta (TGF-beta) family members regulate a variety of cellular functions and play important roles in cell differentiation. Activin receptor-like kinase 7 (ALK7), a receptor for TGF-beta family members, was initially cloned from rats as an orphan receptor and has been recently shown to be a type I receptor for nodal, activin B and activin AB. ALK7 is expressed not only in neurons, but also in insulin-producing islet beta cells and white and brown adipose tissues; however, the specific functions of ALK7 in these tissues are not known. In order to test whether ALK7 is involved in adipocyte differentiation, we analyzed its expression during adipocyte differentiation. ALK7 expression was detected in the late phase of adipocyte differentiation by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence staining in 3T3-L1 cells. We also detected the expression of ALK7 by RT-PCR in stromal vascular fraction (SVF) cells. These results indicated that ALK7 is a novel marker specifically expressed during the late phase of adipocyte differentiation. Furthermore, our results suggest the possible involvement of nodal or activin B in adipocyte differentiation.

Inhibitors of the TGF-β Superfamily and their Clinical Applications

The transforming growth factor-beta (TGF-beta) superfamily includes TGF-betas, activin, myostatin and bone morphogenetic proteins. Misregulation of the activity of TGF-beta family members is involved in pathogenesis of cancer, muscular dystrophy, obesity and bone and tooth remodeling. Natural inhibitors for the TGF-beta superfamily regulate fine-tuning of activity of TGF-beta family in vivo. In addition to natural inhibitors for the TGF-beta family, soluble forms of receptors for the TGF-beta family, blocking monoclonal antibodies and small chemical TGF-beta inhibitors have been developed. In this review, we summarize recent advances in our understanding of inhibitors for the TGF-beta superfamily and their medical applications.

Muscular atrophy of caveolin-3-deficient mice is rescued by myostatin inhibition

Caveolin-3, the muscle-specific isoform of caveolins, plays important roles in signal transduction. Dominant-negative mutations of the caveolin-3 gene cause autosomal dominant limb-girdle muscular dystrophy 1C (LGMD1C) with loss of caveolin-3. However, identification of the precise molecular mechanism leading to muscular atrophy in caveolin-3-deficient muscle has remained elusive. Myostatin, a member of the muscle-specific TGF-beta superfamily, negatively regulates skeletal muscle volume. Here we report that caveolin-3 inhibited myostatin signaling by suppressing activation of its type I receptor; this was followed by hypophosphorylation of an intracellular effector, Mad homolog 2 (Smad2), and decreased downstream transcriptional activity. Loss of caveolin-3 in P104L mutant caveolin-3 transgenic mice caused muscular atrophy with increase in phosphorylated Smad2 (p-Smad2) as well as p21 (also known as Cdkn1a), a myostatin target gene. Introduction of the myostatin prodomain, an inhibitor of myostatin, by genetic crossing or intraperitoneal administration of the soluble type II myostatin receptor, another inhibitor, ameliorated muscular atrophy of the mutant caveolin-3 transgenic mice with suppression of p-Smad2 and p21 levels. These findings suggest that caveolin-3 normally suppresses the myostatin-mediated signal, thereby preventing muscular atrophy, and that hyperactivation of myostatin signaling participates in the pathogenesis of muscular atrophy in a mouse model of LGMD1C. Myostatin inhibition may be a promising therapy for LGMD1C patients.

PACAP Stimulates the Release of Interleukin-6 in Cultured Rat Muller Cells

We have investigated the in vivo effect of PACAP on rat Müller cells that are the predominant glial element in the retina. Müller cells were treated with PACAP38, either alone or in the presence of the PACAP-selective antagonist, PACAP6-38. Cellular proliferation was determined by measuring the incorporation of bromodeoxyuridine, while interleukin-6 (IL-6) levels in the culture medium were examined using a B9 cell bioassay. In cultured rat Müller cells, the expression of PACAP receptor (PAC1-R) was assessed with immunohistochemistry using a PAC1-R-specific antiserum. PACAP stimulated IL-6 production in Müller cells at a concentration as low as 10(-12) M, which was not sufficient to induce cell proliferation. This elevation of IL-6 production was significantly inhibited by PACAP6-38. These data suggest that Müller cells are one of the target cells for PACAP, stimulating the release of IL-6, and providing a mechanism whereby PACAP exerts a significant neuroprotective effect in the retina.

Novel factors in regulation of activin signaling

Activin type II receptors (ActRIIs) are the primary receptors that transmit the activin signal to intracellular signaling pathways. Binding of activins to ActRIIs recruits the activin type I receptor and initiates downstream signaling. We have found that PDZ proteins, named activin receptor-interacting proteins (ARIPs), specifically associate with ActRIIs. We have studied the mechanism that ARIPs regulate cell surface expression and cellular localization of ActRIIs. ARIP2 interacts with both ActRIIs and RalBP1 (Ral binding protein 1) through different domains to dramatically change the localization of ActRIIs. Overexpression of ARIP2 enhances endocytosis of ActRIIs. These data indicate that ARIP2 is a novel factor regulating cell surface ActRII expression and activin function. A novel activin binding protein, follistatin-related gene (FLRG) was identified. FLRG protein binds activin and myostatin with a high affinity. The biological activity of FLRG is similar to those of follistatin, however, the regulation and expression patterns of follistatin and FLRG differ. Immunohistochemical analysis shows that FLRG is distributed in spermatogenic cells of the testis, renal tubules, epithelial cells of the lung, and myocardium. Thus, although structurally and functionally similar, follistatin and FLRG likely play distinct roles as activin/GDF binding proteins in vivo.

Activin isoforms signal through type I receptor serine/threonine kinase ALK7

Activins play a fundamental role in cell differentiation and development. Activin A signaling is mediated through a combination of activin type II receptors (ActRIIs) and the activin type IB receptor, ALK4. Signaling receptors of other activin isoforms remain to be elucidated. Here, we found that activin AB and activin B are ligands for ALK7. ALK7 is an orphan receptor serine/threonine kinase expressed in neuroendocrine tissues including pancreatic islets. The combination of ActRIIA and ALK7, preferred by activin AB and activin B but not by activin A, is responsible for activin-mediated secretion of insulin from pancreatic beta cell line, MIN6. In contrast, all activins activate a combination of ActRIIA and ALK4 with various levels of potency. Thus, variation in activin signaling through type I receptors is dependent upon homo- and heterodimeric assembly of activin isoforms. Thus, the differential combination of receptor heterodimers mediates variation in activin isoform signaling.

Study of Dural Arteriovenous Fistula Drains into Leptomeningeal Vein without Sinus Interposition

SUMMARY

We evaluated dural arteriovenous fistulas (DAVF) drains into leptomeningeal vein (LMV) without the venous sinus interposition. This type of DAVF contained the extra-sinusal type DAVF and the DAVF with so-called pure leptomeningeal venous drainage (PLMVD).We studied 15 patients with DAVF that flows into LMVD without passing into the sinus. The subjects were 5 patients with DAVF in the anterior cranial fossa, 2 with DAVF in the tentorium cerebelli, and 3 with DAVF in the craniocervical junction as extra-sinusal type DAVF and 3 with DAVF in the transverse sigmoid sinus and 2 with DAVF in the superior sagittal sinus as DAVF with PLMVD. This type appears to take a very aggressive course. The arterial pressure of the shunt is directly applied to LMV, which causes bending and winding of the vein, eventually varices, inducing intracranial haemorrhage or venous ischemia in the LMV reflux area. Emergency treatment should be performed as soon as possible. Although it is recognized that interruption of the draining vein is very effective, treatment methods such as TAE, direct surgery, and g knife treatment, or their combinations should be carefully chosen for each case.

Genomic organization and promoter analysis of mouse follistatin-related gene (FLRG)

Follistatin (FS) is well characterized as an activin-binding protein. Recently, a novel follistatin-like protein called follistatin-related gene (FLRG) that has a similar domain organization to that of follistatin has been identified. Like follistatins, FLRG binds activins and bone morphogenetic proteins (BMPs). To study the regulation of FLRG expression, we have analyzed the genomic organization and promoter of the mouse FLRG gene. The mouse FLRG gene consists of five exons, and each encodes discrete functional regions. The overall genomic structure of FLRG is similar to that of FS except that the FLRG gene is missing one exon that codes a third FS domain found in FS. The promoter that covers 2.5 kbp and is linked to a luciferase reporter construct is active in human cervical carcinoma HeLa cells as well as in human embryonic kidney (HEK293) cells. Deletion analysis of the promoter regions indicates that a proximal 550 base pairs are enough for basal FLRG promoter activity in the cell lines. FLRG promoter activity is significantly augmented by phorbol 12-myristate 13-acetate (PMA) treatment, but not by cAMP stimulation. By contrast, FS promoter is activatable either by cAMP or PMA. Thus, although FS and FLRG are structurally and functionally related, their modes of regulation by external stimuli are different.

The involvement of vascular endothelial growth factor and flt-1 in the process of neointimal proliferation in pig coronary arteries following stent implantation

To clarify the role of vascular endothelial growth factor (VEGF) in the process of restenosis, a Palmaz-Schatz stent was implanted in the left anterior descending coronary artery of male pigs at 2 weeks after balloon injury (balloon/artery ratio 1.2:1). The animals were euthanized at 1, 2, and 4 weeks after stenting, and western blot and immunohistochemical analysis were performed using VEGF, fms-like tyrosine kinase (flt)-1, and platelet-derived growth factor (PDGF) antibodies. The expressions of VEGF and flt-1 protein in the neointima were observed as early as 1 week after stenting and remained for up to 4 weeks, while re-endothelialization was complete at 2 weeks. These protein expressions were demonstrated in proliferated smooth muscle cells throughout the entire period after stenting and, in addition, they were observed in the macrophages and endothelial cells of microvessels around stent struts at 4 weeks. The expression pattern of VEGF corresponded with that of PDGF, a growth factor well-known to induce neointimal proliferation. The cell proliferative activity, measured by the proliferating cell nuclear antigen index, around the struts remained high until 4 weeks after stenting, while that in the other areas declined at 4 weeks. These results suggest that VEGF is involved in the process of restenosis not only through its angiogenic properties and induction of monocyte chemotaxis, but also by a synergistic effect with PDGF.

Diterpenoids from Euphorbia paralias

Two segatane diterpenoids containing a bicyclic [4,3,1] ring system were isolated, together with 11 known diterpenoids, four segetanes, five jatrophanes and two paralianes, from the aerial parts of Euphorbia paralias. The structures of the new compounds were established by spectroscopic means, including by 2D NMR and CD spectroscopic analyses. The antifeedant and antiviral activities of the isolated compounds are also described.

[Morphological and histological studies of in-stent restenosis in seven types of stents implanted in porcine coronary arteries]

OBJECTIVES

Differences in the mechanism of restenosis after stenting between coil and tubular stents were examined in porcine coronary arteries using histological and immunohistochemical methods.

METHODS

Twenty-four pigs underwent balloon-induced injury in the left anterior descending coronary artery. Two weeks later, seven different stents clinically available in Japan (Coil stents: GR I, GR II, Wiktor, Cordis; Tubular stents: gfx, Multilink, Palmaz-Schatz) were implanted in the injured site. Four weeks after the stent implantation, the pigs were sacrificed for histological examination and for morphometrical analysis of the lumen, neointima, media and adventitia. Immunohistochemical studies using anti-proliferating cell nuclear antigen (PCNA), anti-alpha-smooth muscle actin and anti-macrophage antibody were also performed.

RESULTS

The coil stents formed eccentric, and the tubular stents formed concentric neointimal proliferation. Although there was no difference in the area of neointima between the stents, the area of lumen in the tubular stents was bigger than that in the coil stents (p < 0.01), because the vascular area was bigger in the tubular stents (p < 0.05). Immunohistochemical examination found many PCNA-positive cells in the proliferated neointima, especially in the area around the stent strut. Many of these cells around the stent strut were positively stained by anti-macrophage antibody. Other cells positively stained for PCNA were confirmed as smooth muscle cells.

CONCLUSIONS

Tubular stents maintained a wider lumen than coil stents, because negative remodeling after stenting was less in the tubular stents. Implantation of stents with less negative remodeling is very important to prevent restenosis after stenting.

Antifeedant rings B and D opened limonoids from Khaya senegalensis

Three new rings B and D opened limonoids, two mexicanolides named khayanone (1) and 2-hydroxyseneganolide (2) and one rearranged phragmalin limonoid of 1-O-acetylkhayanolide A (3), were isolated together with six known B,D-seco compounds from the acetone extract of the stem bark of Khaya senegalensis. Structures of new compounds were elucidated by spectroscopic means, and the absolute stereochemistry of 1 was established by CD study of the dibenzoate derivative. The insect antifeedant and antiviral activities of the new compounds were also determined.

Studies toward the total synthesis of popolohuanone E: enantioselective synthesis of 8-O-methylpopolohuanone E

[structure: see text]. 8-O-methylpopolohuanone E (2) was synthesized in a highly convergent manner starting from the cis-fused decalin derivative accessible from the (-)-Wieland-Miescher ketone analogue. The synthetic method features a biogenetic-type annulation of the phenolic and quinone segments to regioselectively construct the central tricyclic ring system as the key step.

Successful use of a defined antigen/GM-CSF adjuvant vaccine to treat mucosal Leishmaniasis refractory to antimony: A case report

Immunotherapy has been proposed as a method to treat mucosal leishmaniasis for many years, but the approach has been hampered by poor definition and variability of antigens used, and results have been inconclusive. We report here a case of antimonial-refractory mucosal leishmaniasis in a 45 year old male who was treated with three single injections (one per month) with a cocktail of four Leishmania recombinant antigens selected after documented hypo-responsiveness of the patient to these antigens, plus 50 microg of GM-CSF as vaccine adjuvant. Three months after treatment, all lesions had resolved completely and the patient remains without relapse after two years. Side effects of the treatment included only moderate erythema and induration at the injection site after the second and third injections. We conclude that carefully selected microbial antigens and cytokine adjuvant can be successful as immunotherapy for patients with antimonial-refractory mucosal leishmaniasis.

[Effects of home oxygen therapy on patients with chronic heart failure]

OBJECTIVES

Dyspnea on exertion and/or hypoxemia due to nocturnal respiratory disturbance may occur in patients with stable chronic congestive heart failure. Such patients with respiratory disorder during sleep have a poor prognosis. The effects of treatment with home oxygen therapy on patients with congestive heart failure are unclear when symptoms are stable at rest. This study investigated the effects of home oxygen therapy on patients with stable chronic congestive heart failure.

METHODS

Thirty-three patients with stable chronic congestive heart failure(New York Heart Association functional class II-IV) and hypoxemia during exercise or sleep were treated with oxygen above the level of 90% SaO2. The following factors were compared before and after home oxygen therapy: Subjective minimal capacity on exercise(metabolic equivalents: METs) before and 1 month after patients first became aware of dyspnea on effort using the specific activity scale(SAS); SaO2 at rest before and 1 month after; and frequency of admission during 1 year due to deterioration of heart failure.

RESULTS

After home oxygen therapy, SAS improved from 2.5 +/- 0.9 to 3.3 +/- 1.0 METs(p < 0.0001), and SaO2 at rest improved from 92.8 +/- 2.5% to 96.3 +/- 1.6%(p < 0.0001). The frequency of admission was decreased from 1.3 +/- 1.2 to 0.8 +/- 1.2 times(p = 0.03).

CONCLUSIONS

Home oxygen therapy is effective for improving the symptoms and activity of daily life in patients with chronic heart failure. Home oxygen therapy may prevent the deterioration of heart failure.

Treatment of chronic suppurative otitis media with Broncasma Berna

Broncasma Berna, an inactivated bacterial vaccine, has been safely used throughout the world for 30 years for the prevention or treatment of various infectious processes. Until now, there has been no published report regarding its use as a treatment for chronic suppurative otitis media. In this small study, five such patients (median age: 57 years) underwent a series of seven 0.05-ml injections of Broncasma Berna. In all cases, their otorrhea diminished markedly and their tympanic membranes were almost completely dry. The cost of treatment was extremely low.

[Usefulness of three-dimensional color Doppler sonography for the differential diagnosis of subpleural lesions]

The purpose of our investigation was to assess the usefulness of three-dimensional color Doppler sonography (velocity mode and power mode) for the differential diagnosis of subpleural lesions. Thirty lesions (11 pneumonias, 5 lung abscesses, 11 primary lung cancers, 3 metastatic lung cancers) were examined. Three-dimensional images were reconstructed by a maximum intensity projection method. Three-dimensional representations of intralesional blood flow became available for all lesions approximately 11 seconds after scanning. In every case, the entire vasculature of the tumor, the pneumonia, the abscess, or the inflamed region of the lung was appreciated more easily from three-dimensional images than from two-dimensional images. We classified the color flow pattern of subpleural lesions depicted by color flow imaging into seven groups. Color flow was depicted better by the three-dimensional color Doppler power mode than the velocity mode. Three-dimensional color flow patterns observed in power mode, patterns of the pneumonias and the lung cancers differed significantly. Our results suggest that the three-dimensional color Doppler power mode is useful for the differential diagnosis of subpleural lesions.

Hyperperfusion phenomenon after percutaneous transluminal angioplasty for atherosclerotic stenosis of the intracranial vertebral artery

✓ The authors report on a patient who underwent percutaneous transluminal angioplasty (PTA) for stenosis of the intracranial vertebral artery (VA). This 67-year-old man's dizziness while walking was caused by infarction of the left cerebellar peduncle. On angiograms, his left VA manifested 90% stenosis at the intracranial portion and his right VA ended at the posterior inferior cerebellar artery. Because single-photon emission computerized tomography (SPECT) showed low perfusion and poor perfusion reserve in the posterior circulation, the authors performed PTA of the left VA, which was only 35% dilated due to stenosis. Although the patient's postoperative course was uneventful, postoperative hemodynamic studies (SPECT and transcranial Doppler [TCD] ultrasonography) revealed the hyperperfusion phenomenon. A 100% increase of regional cerebral blood flow in the posterior circulation was demonstrated on SPECT studies and TCD ultrasonography revealed a doubling of blood flow velocity in the VA compared with preoperative values. Careful control of the patient's blood pressure resulted in resolution of the hyperperfusion phenomenon within 1 week post-PTA. Although hyperperfusion syndrome following carotid endarterectomy is not rare, it is seldom seen after reconstruction of the posterior circulation, and the possibility of its occurrence must be kept in mind when the posterior circulation is reconstructed.

Studies on defatted seed removal efficiency for organochlorine compounds

Defatted seeds were evaluated for effective adsorption of organochlorine compounds such as chloroform, dichloromethane, and trichloroethylene. The amounts of these compounds adsorbed were plotted against the equilibrium concentration of substances in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reactions were of the Freundlich type. The removal of these organochlorine compounds by defatted seed was attributed to the uptake by intracellular particles called spherosomes.

A DNA ligase from a hyperthermophilic archaeon with unique cofactor specificity

A gene encoding DNA ligase (lig(Tk)) from a hyperthermophilic archaeon, Thermococcus kodakaraensis KOD1, has been cloned and sequenced, and its protein product has been characterized. lig(Tk) consists of 1,686 bp, corresponding to a polypeptide of 562 amino acids with a predicted molecular mass of 64,079 Da. Sequence comparison with previously reported DNA ligases and the presence of conserved motifs suggested that Lig(Tk) was an ATP-dependent DNA ligase. Phylogenetic analysis indicated that Lig(Tk) was closely related to the ATP-dependent DNA ligase from Methanobacterium thermoautotrophicum DeltaH, a moderate thermophilic archaeon, along with putative DNA ligases from Euryarchaeota and Crenarchaeota. We expressed lig(Tk) in Escherichia coli and purified the recombinant protein. Recombinant Lig(Tk) was monomeric, as is the case for other DNA ligases. The protein displayed DNA ligase activity in the presence of ATP and Mg(2+). The optimum pH of Lig(Tk) was 8.0, the optimum concentration of Mg(2+), which was indispensable for the enzyme activity, was 14 to 18 mM, and the optimum concentration of K(+) was 10 to 30 mM. Lig(Tk) did not display single-stranded DNA ligase activity. At enzyme concentrations of 200 nM, we observed significant DNA ligase activity even at 100 degrees C. Unexpectedly, Lig(Tk) displayed a relatively small, but significant, DNA ligase activity when NAD(+) was added as the cofactor. Treatment of NAD(+) with hexokinase did not affect this activity, excluding the possibility of contaminant ATP in the NAD(+) solution. This unique cofactor specificity was also supported by the observation of adenylation of Lig(Tk) with NAD(+). This is the first biochemical study of a DNA ligase from a hyperthermophilic archaeon.

A new quinolizidine alkaloid from the Papua New Guinean sponge Xestospongia exigua

A new bis-quinolizidine alkaloid, xestosin A (1), possessing cis- and trans-quinolizidine nuclei, has been isolated from the Papua New Guinean sponge Xestospongia exigua. The structure was determined by spectrometric and single-crystal X-ray analyses.

Anthocyanins in callus induced from purple storage root of Ipomoea batatas L

Two anthocyanins were isolated from the highly pigmented callus derived from the storage root of purple sweet potato (Ipomoea batatas L.) cultivar 'Ayamurasaki'. One was identified as cyanidin 3-O-sophoroside-5-O-glucoside, and the other as cyanidin 3-O-(2-O-(6-O-(E)-p-coumaroyl-beta-D-glucopyranosyl)-beta-D-glucop yranoside)-5-O-beta-D-glucopyranoside, by chemical and spectroscopic analysis.

[Changes of serum hepatocyte growth factor in coronary artery disease]

Hepatocyte growth factor (HGF) is an endothelial cell specific growth factor involved in the repair of endothelial cells and collateral formation, however, the role for coronary artery disease is still unknown. We measured serum HGF level in various coronary artery diseases to examine the clinical significance. Serum HGF level was measured using the enzyme-linked immunosorbent assay method in patients with stable effort angina pectoris (n = 26), old myocardial infarction (n = 18), unstable angina pectoris (UAP; n = 10) and acute myocardial infarction (AMI; n = 21). As a control group, we selected 11 patients with neurocirculatory asthenia. Blood samples from peripheral veins were collected at cardiac catheterization before heparin administration. In the AMI group, blood samples were also collected at 48, 72 hr, 1, 2, 3 and 4 weeks from the peripheral veins and 48 and 72 hr after reperfusion from the coronary sinus. Serum HGF level was significantly higher in the UAP (0.41 +/- 0.12 ng/ml, p < 0.001) and AMI groups (0.38 +/- 0.26 ng/ml, p < 0.05) compared to the control group (0.19 +/- 0.09 ng/ml). Serum HGF level peaked 48 hr after reperfusion in both the peripheral veins (0.42 +/- 0.16 ng/ml) and coronary sinus (0.58 +/- 0.23 ng/ml) in the AMI group, with a significantly higher level in the coronary sinus than the peripheral veins (p < 0.05). No significant correlation between peak HGF level in the peripheral veins and peak creatine kinase (CK), CK-MB, ejection fraction and cardiac index was observed. Serum HGF was elevated in acute coronary syndrome, indicating advanced endothelial cell damage. HGF is produced, at least partially, in the heart in patients with AMI. Serum HGF level may be useful to detect endothelial cell damage rather than myocardial cell damage.

Establishment and characteristics of an anthocyanin-producing cell line from sweet potato storage root

 Anthocyanin pigments accumulated in a cell line derived from storage-root explants of sweet potato (Ipomoea batatas L.) cv 'Ayamurasaki'. Somatic pro-embryos were induced on the explants cultured on Murashige and Skoog medium supplemented with 1 mg/l 2,4-D. The pro-embryo structures produced callus when transferred to MS medium with 0.5 mg/l 2,4-D. A cell line was isolated from this callus which accumulated anthocyanin pigment. The color value of the pigment extracted after 27 days of culture in MS medium with 2 mg/l 2,4-D was 8.2, which was very close to that of a pigment extracted from roots, which was 8.9. Most of the pigments from the cell extract were hydrophilic and appeared on the ODS-column HPLC with a lower retention time than the main anthocyanins of the root tissues. The majority of the pigments were identical with the root anthocyanins. Cell line-specific anthocyanins were detected.

New xenicane diterpenes isolated from the acetone extract of the soft coral Xenia florida

Six new xenicane diterpenes have been isolated from the acetone extract of the soft coral Xenia florida. Two of them are diterpenes containing a bicyclic [4.3.1] ring system. Three of them seem to be precursors for diterpenes possessing the bicyclic [4.3.1] ring system. One is a common monocarbocyclic diterpene with a cyclononane skeleton.

[Possibility of discharge and need for rehabilitation of psychiatric patients hospitalized for one year or more in Japan: a preliminary report. Committee on Rehabilitation Affairs, Subcommittee of Survey on Rehabilitation Need]

A total of 19,342 psychiatric patients staying in a total of 143 hospitals in Japan for one year or more entered in this study in order to determine the possibility of discharge (POD) and the need for rehabilitation. Those who were assessed by the psychiatrist in charge to have POD provided community support was assured accounted for 32.5%. As for the levels of daily life functions measured with the GAF score, those assessed to have POD showed the maximum frequency between scores 51 and 60, while the others, who were not considered suitable for discharge, showed the maximum frequency between scores 21 and 30. On the other hand, the control group, consisting of subjects with psychiatric disabilities and living in the community while using day care or rehabilitation facilities, showed the maximum frequency of GAF scores between 51 and 60. Two-thirds of the study subjects were older than fifty, while in the control group those aged between 30 and 49 accounted for 49.0%, thus indicating that the residents of mental hospitals tend to be older. More than 60% of the study subjects had been staying in hospital for five years or more. Those without their own home accounted for about 60%.

The role of ATP-sensitive potassium channels in the mechanism of ischemic preconditioning

We clarified the role of K(ATP) channels in the mechanism of ischemic preconditioning by using K(ATP) channel opener, nicorandil, and K(ATP) channel inhibitor, glibenclamide. Forty anesthetized dogs were divided into five groups: (a) control (C), (b) ischemic preconditioning (PC), (c) intravenous infusion of nicorandil before PC (Ni), (d) glibenclamide pretreated with PC (Gl + PC), and (e) glibenclamide pretreated with Ni (Gl + Ni). All groups were followed by 60-min ischemia and 60-min reperfusion and analyzed by the biochemical procedures. At the end of 60-min reperfusion, percentage of segment shortening in C indicated paradoxic bulging. This value was significantly recovered in PC and Ni, but it was still negative in Gl + PC and Gl + Ni. Ca2+ -adenosine triphosphatase (ATPase) activity of sarcoplasmic reticulum (SR) was significantly decreased in C. In PC and Ni, this activity was significantly maintained; however, in Gl + PC and Gl + Ni, it was similar to that in C. State III respiration of mitochondria showed similarity to the changes in SR. These results indicated that the K(ATP) channel opener enhanced the effects of ischemic preconditioning, and its blockade abolished these phenomena. We conclude that the ATP-sensitive potassium channel may play one of key roles in the mechanisms of ischemic preconditioning in the dog model.

[Effects of low dose pimobendan in patients with cor-pulmonale]

The acute and chronic efficacy of low dose pimobendan (1.25 mg x 2/day) was evluated in patients with cor-pulmonale. Fifteen patients (12 men, 3 women, mean age 73 +/- 5 yr) with right ventricular dysfunction judged by Tei's Doppler index (> or = 0.4) and poor working capacity (exercise tolerance: 2.2-6.6 MET) were studied. Mean pulmonary artery pressure, cardiac output, total pulmonary resistance using Swan-Ganz catheter, and arterial oxygen and carbon dioxide pressure (PaO2, PaCO2) were measured before and 24 hr after pimobendan administration. Maximal oxygen intake (MET), saturation of arterial blood oxygen at rest and desaturation by treadmill stress test were measured before and 1 month after pimobendan administration. Pulmonary artery pressure decreased (17.6 +/- 4.7 to 10.2 +/- 2.3 mmHg, p < 0.001) and cardiac output increased (3.5 +/- 0.6 to 5.1 +/- 0.9 l/min, p < 0.001), resulting in decreased total pulmonary resistance (5.0 +/- 1.3 to 2.1 +/- 0.7 U, p < 0.001), and a mild decrease in PaO2 (74 +/- 8 to 70 +/- 10 mmHg, p < 0.05). Exercise tolerance improved significantly (4.8 +/- 1.7 to 6.8 +/- 2.2 MET, p < 0.001), without deterioration of PaO2 and desaturation. These results indicate that low dose pimobendan is useful for the treatment of patients with cor-pulmonale.

New cembranes from the soft coral sarcophyton species

Three new cembranes, including one with a 13-membered carbocyclic ring, have been isolated from the soft coral Sarcophyton sp.

Competitive adsorption between phospholipid and plasma protein on a phospholipid polymer surface

The competitive adsorption of proteins and phospholipids on omega-methacryloyloxyalkyl phosphorylcholine (MAPC) polymer was evaluated in this study. Albumin, fibrinogen, and dimyrstoyl phosphatidylcholine (DMPC) were used as model components. The amount of DMPC adsorbed on the MAPC polymers increased with an increase in the MAPC unit composition of the polymer. The methylene chain length of the MAPC unit was another factor influencing the DMPC adsorption when the MAPC unit composition of the MAPC polymer was low. The state of albumin and DMPC liposome adsorbed on the 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer was determined by dynamic contact angle (DCA) measurement. The adsorption strength of albumin on the MPC polymer was weaker than that on the poly[n-butyl methacrylate (BMA)], that is, the albumin was detached from the MPC polymer during the rinsing process. On the poly(BMA) surface, no difference in the shape of the DCA loops before and after contact with the DMPC liposomal suspension was observed. Fibrinogen adsorption on the MAPC polymer was detected by gold-colloid labeled immunoassay. The amount of fibrinogen adsorbed on every MAPC polymer surface was reduced by addition of the DMPC liposome in the fibrinogen solution. The number of platelets adhered on the MAPC polymer was also decreased when the DMPC liposome was present in the fibrinogen solution during pretreatment. We concluded that phospholipids were preferentially adsorbed on the MAPC polymer surface compared with plasma protein and that the adsorbed phospholipids played an important role in showing an excellent blood compatibility on the MAPC polymer.

Effect of non-selective endothelin blockade, TAK-044, on the ischemic cellular injury of rat heart

The aim of this study is to evaluate the role of non-selective endothelin blockade (TAK-044) in ischemic myocardial injury. Forty anesthetized rats were separated into four groups: 1) TAK-I group, after preinjection of TAK-044 (3 mg/kg), LAD was ligated for 60 min and reperfused for 60 min; 2) Saline (SAL)-I group, LAD ligation and reperfusion without TAK-044; 3) TAK-C group, sham operated TAK group; 4) SAL-C group, sham-operated SAL group. Myocardium from each group was separated and analyzed by biochemical and ultrastructural procedures. Reperfusion arrhythmia (VT) was observed in 88% of the SAL-I group, in contrast to only 36% of the TAK-I group. At the end of reperfusion, hemodynamics indicated no significant differences between these two groups. The Ca(++)-ATPase activity of sarcoplasmic reticulum (SR) was 3.9 mumoles Pi/mg protein/h (39% of SAL-C group) in the SAL-I group, while that in the TAK-I group was significantly higher at 6.1 (54%). The ratio of infarct/risk area was 58% in the SAL-I group and 36% in the TAK-I group. In the ultrastructural observations, irreversibly injured cells of the ischemic portion were reduced significantly from 35% (SAL-I group) to 14% (TAK-I group). Thus, our results indicated that endothelin blockade reduced ischemic cellular injury. The mechanism of this reduction was speculated to be a resistance to ischemic injury in the subcellular levels of the myocardium conferred by a reduction of vascular constriction and improvement of imbalance in the energy supply and demand.

Biochemical and ultrastructural evaluations of the effect of ischemic preconditioning on ischemic myocardial injury--role of the adenosine triphosphate-sensitive potassium channel

The aim of this study was to clarify the role of the adenosine triphosphate (ATP)-sensitive potassium channel on the mechanism of ischemic preconditioning (IP). Thirty-five anesthetized dogs were divided into 5 groups: (1) Control (C), (2) IP, (3) intravenous infusion of nicorandil (Ni) prior to IP, (4) glibenclamide (G1) pretreated with IP (G1+IP), and (5) G1 pretreated with Ni (G1+Ni). All groups had 60 min ischemia followed by 60 min reperfusion, and were analyzed by biochemical and morphological procedures. At the end of the 60-min reperfusion, %segment shortening in C indicated paradoxical bulging. This value had significantly recovered in IP and Ni groups, but it was still negative in the G1+IP and G1+Ni groups. Ca++-ATPase activity of the sarcoplasmic reticulum (SR) was significantly decreased in C. In the IP and Ni groups, this activity was significantly maintained; however, in the G1+IP and G1+Ni groups it was similar to that in C. State 3 respiration of mitochondria showed similar changes in the SR. In the ultrastructural observations, severely damaged cells were not observed in the IP and Ni groups. These results indicated that an ATP-sensitive potassium channel opener enhanced the effects of IP and its blockade abolished these phenomena. It was conclude that the ATP-sensitive potassium channel may play a key role in the mechanism of IP.

New alkaloids from the papua new guinean sponge agelas nakamurai

Two new bromopyrroles and a new diterpene possessing a 9-methyladenium moiety have been isolated from the Papua New Guinean sponge Agelas nakamurai Hoshino.

Which vertebrae should be assessed in diagnosing osteoporosis by plain radiography? Comparative study of radiographic findings and bone mineral density measured by dual energy X-ray absorptiometry

In 1990, the Ministry of Health and Welfare of Japan advocated a criterion for the diagnosis radiographic bone atrophy in lumbar vertebrae. We carried out a comparative study of this criterion (i.e. , radiographic bone atrophy grading) and bone mineral density measured by posteroanterior and lateral dual energy X-ray absorptiometry. We investigated the second to fourth lumbar vertebrae of 47 postmenopausal women (mean age, 67.2 years; range, 57-82 years), to determine which vertebra would most accurately indicate osteoporosis. A significant difference in bone mineral density (P < 0.01) was found between each grade of radiographic bone atrophy in all of the second, third, and fourth vertebrae examined. The highest correlation (r = 0.714) was found between the radiographic grades and the bone mineral density on lateral dual energy X-ray absorptiometry of the third lumbar vertebrae. Our visual determinations were dependable, radiographic and a examination of the third lumbar vertebra rather than that of other lumbar vertebrae was more helpful for the detection of radiographic bone atrophy. Plain radiographic film can provide a rough estimation of bone atrophy.

Roles of conserved arginine residues in the metal-tetracycline/H+ antiporter of Escherichia coli

Seven arginine residues are conserved in all the tetracycline/H+ antiporters of Gram-negative bacteria. Four (Arg67, -70, -71, and -127) of them are located in the putative cytoplasmic loop regions and three (Arg31, -101, and -238) in the putative periplasmic loop regions [Eckert, B., and Beck, C. F. (1989) J. Biol. Chem. 264, 11663-11670]. These arginine residues were replaced by alanine, lysine, or cysteine one by one through site-directed mutagenesis. None of the mutants showed significant alteration of the protein expression level. The mutants resulting in the replacement of Arg31, Arg67, Arg71, and Arg238 with either Ala, Cys, or Lys retained tetracycline resistance levels comparable to that of the wild type. Among them, only the Arg238 --> Ala mutant showed very low transport activity in everted membrane vesicles, probably due to the instability of the mutant protein. The replacement of Arg70 and Arg127 with Ala or Cys resulted in a drastic decrease in the drug resistance and almost complete loss of the transport activity, while the Lys replacement mutants retained significant resistance and transport activity, indicating that the positively charged side chains at these positions conferred the transport function. On the other hand, neither the Ala, Cys, nor Lys replacement mutant of Arg101 exhibited any drug resistance or transport activity. As for the reactivity of the Cys replacement mutants, only two (Arg71 --> Cys and Arg101 --> Cys) were not reactive with NEM, the other five mutants being highly or moderately reactive. The reactivity of the cysteine-scanning mutants around Arg101 with NEM revealed that Arg101 is located in transmembrane helix IV. It is not likely that Arg101 confers the protein folding through a salt bridge with a transmembrane acidic residue because no double mutants involving Arg101 --> Ala and the replacement of one of three transmembrane acidic residues (Asp15, Asp84, and Asp285) showed the recovery of any tetracycline resistance or transport activity. The effect of tetracycline on the [14C]NEM binding to the combined mutants S65C/R101A and L97C/R101A suggests that Arg101 may cause a substrate-induced conformational change of the putative exit gate of TetA(B).

New adsorption column (Lixelle) to eliminate beta2-microglobulin for direct hemoperfusion

The Lixelle column is an adsorbent column used to eliminate beta2-microglobulin (beta2M) selectively from circulating blood of dialysis related amyloidosis (DRA) patients, which is used in combination with a dialyzer in series. The column has such a high capacity for adsorbing beta2M that the most intensive removal of beta2M has been possible. In clinical trials of the column, the obvious improvement of subjective symptoms such as decreases in the frequency of nocturnal awakening, the joint pain severity index, and the joint mobility index were observed. Hypotension has been the most frequent adverse event observed during treatment since the column was put on the market. It is very important to clarify the causes of both the efficacy and the side effects. A controlled prospective study is now in progress to clarify the efficacy more scientifically. The results will be published soon elsewhere.

On the treatment of recurrent tonsillitis by vaccination

This paper reports on the experience of using vaccination in the treatment of recurrent tonsillitis. All of the 82 patients, who were aged between 5 and 67 years and who suffered from recurrent tonsillitis, were given an injection of a bacterial vaccine (Broncasma Berna, Swiss Serum Institute, Berne) that has been used in many countries for three decades. A dose of 0.05 ml was given once every 4 to 14 days (average once a week) on 3 to 20 occasions (average 8). The treatment prevented 75 of the 82 patients (91%) from having attacks of recurrent tonsillitis for extended periods. These 75 patients included three who relapsed into recurrent tonsillitis in spite of having tonsillectomies. As the dose used was relatively small, none of the patients complained of spontaneous pain or fever although three complained of slight tenderness at the injection point on the following day. The effect on recurrent tonsillitis of the Paspat intracutaneous injection (Luitpold Werk, Munich) has also been investigated recently. It was effective in two patients who did not respond to Broncasma Berna. In this retrospective study, low doses of bacterial vaccine reduced the incidence of recurrent tonsillitis and were well tolerated.

Developmentally regulated release of intraretinal neurotrophic factors in vitro

The effects of conditioned media either from aggregates or from explants of embryonic chick retinae and of recombinant neurotrophins were tested upon the survival in vitro of ganglion cells in dissociated cell cultures from the retina of newborn rats. Ganglion cells were identified by the detection of retrogradely transported horseradish peroxidase injected bilaterally into the superior colliculus. Conditioned media increased significantly the survival of ganglion cells after 2 days in culture, at a wide range of plating densities, and had no effect upon adhesion of rat retinal cells. Media conditioned by cell ensembles from chick retinae from embryonic day 8 (E8) to E16 had neurotrophic effects. Release of neurotrophic activity peaked at E10 E12, irrespective of the numbers of cells or total concentration of protein in the conditioned media. The active molecules were non-dialyzable and were released either in the presence or in the absence of fetal calf serum. The neurotrophic activity was abolished by trypsinization, and recovered by salting-out with 25 75% ammonium sulfate. NT-4, BDNF and, to a lesser extent, NT-3, increased the survival of ganglion cells in our assay, while NGF had no effect. The data show that chick retinal cells release soluble trophic proteins according to a developmentally regulated pattern. These neurotrophic factors may be involved in local competitive interactions that help control naturally occurring neuron death among ganglion cells of the vertebrate retina.

Death in a dish: controls of apoptosis within the developing retinal tissue

Studies of programmed cell death in the developing retina in vitro are currently reviewed. The results of inhibiting protein synthesis in retinal explants indicate two mechanisms of apoptosis. One mechanism depends on the synthesis of positive modulators ('killer proteins'), while a distinct, latent mechanism appears to be continuously blocked by negative modulators. Extracellular modulators of apoptosis include the neurotrophic factors NT-4 and BDNF, while glutamate may have either a positive or a negative modulatory action on apoptosis. Several protein kinases selectively modulate apoptosis in distinct retinal layers. Calcium and nitric oxide were also shown to affect apoptosis in the developing retinal tissue. The protein c-Jun was found associated with apoptosis in various circumstances, while p53 seems to be selectively expressed in some instances of apoptosis. The results indicate that the sensitivity of each retinal cell to apoptosis is controlled by multiple, interactive, cell type- and context-specific mechanisms. Apoptosis in the retina depends on a critical interplay of extracellular signals delivered through neurotrophic factors, neurotransmitters and neuromodulators, several signal transduction pathways, and the expression of a variety of genes.