Soft dipole resonance in the neutron-skin nucleus 6He

A candidate for a soft dipole resonance, a dipole oscillation mode between a core cluster and a neutron skin, was observed at Ex = 4+/-1 MeV and with a width of 4+/-1 MeV in 6He via the 6Li( 7Li, 7Be) reaction at an incident energy of 65A MeV and forward scattering angles including 0 degrees. Its cross section is deduced to be sigma(0 degrees ) = 0.9+/-0.2 mb/sr. This value is comparable to that of the giant dipole resonance simultaneously measured.

Aminopeptidase A expression in cervical neoplasia and its relationship to neoplastic transformation and progression

Aminopeptidase A (AP-A) is a cell surface metallopeptidase which specifically cleaves the amino-terminal acidic residue from peptide substrates such as angiotensin II. AP-A is identical to the differentiation-related antigen, murine BP-1 or human kidney gp160, and is involved in regulating cell differentiation and/or neoplastic transformation of certain normal and transformed cells. We examined expression of AP-A in premalignant and malignant lesions of the uterine cervix, and investigated whether its expression was related to disease progression and neoplastic transformation. Formalin-fixed, paraffin-embedded tissue sections including 14 cervical intraepithelial neoplasms (CIN) and 23 invasive squamous cell carcinomas (SCC) were immunohistochemically evaluated. AP-A was localized in the basal cell layer in normal squamous epithelium. In CIN, AP-A expression was found on dysplastic cells, and increased with the severity of the precancerous lesions. In invasive cancer, 18 of 19 non-keratinizing-type SCCs and none of 4 keratinizing-type SCCs expressed AP-A. In addition, AP-A immunoreactivity was significantly correlated with proliferating cell nuclear antigen expression in both CIN and SCC cases. Furthermore, angiotensin II type 1 receptor was present in all AP-A-positive SCCs. These results indicate that AP-A is upregulated as the lesion progresses toward carcinoma in the cervical epithelium, and suggest that AP-A may play a regulatory role in neoplastic transformation and disease progression in cervical neoplasms and may serve as a potential tumor marker during cervical neoplasia development.

Common C677T polymorphism in the methylenetetrahydrofolate reductase gene increases the risk for deep vein thrombosis in patients with predisposition of thrombophilia

The alanine/valine (A/V) gene polymorphism of 5, 10-methylenetetrahydrofolate reductase (MTHFR), one of the key enzymes catalyzing remethylation of homocysteine, has been reported and the VV genotype is associated with increased plasma homocysteine levels as a result of the reduced activity and increased thermolability of this enzyme. Although previous studies have suggested that the VV genotype is a risk factor for arterial occlusive disease, whether the VV genotype is a risk factor for venous thrombosis is still controversial. Here we screened 72 Japanese patients with deep venous thrombosis (DVT) and 85 controls for this mutation, and we measured plasma levels of homocysteine to determine whether the thermolabile variant with the VV genotype is a risk factor for DVT in a Japanese population. Of the 72 patients with DVT, 10 (13.9%) were found to be homozygous for the VV genotype, and in 6 (7.0%) of 85, control individuals and the difference was not significant (odds ratio=2.12, 95% CI=0.73-6.16, p=0.19). When we divided the DVT patients into subgroups, with and without predisposition of thrombophilia, including deficiencies of proteins C and S, plasminogen, and lupus anticoagulant, the prevalence of the VV genotype in DVT patients with predisposition was significantly higher than that of the normal controls (odds ratio=5.99, 95% CI=1. 56-22.96, p=0.01). However, the prevalence of the VV genotype in DVT patients without predisposition was not significantly different from that of the normal controls (odds ratio=1.20, 95% CI=0.32-4.47, p=0. 75). The plasma homocysteine levels in patients with DVT (11.6+/-5.2 nmol/ml) was not significantly different from that of the control subjects (11.6+/-3.7 nmol/ml). Individuals with the VV genotype showed higher plasma homocysteine levels (15.4+/-6.9 nmol/ml) than did individuals with the AV genotype (11.2+/-3.7 nmol/ml, p=0.009) or in individuals with the AA genotype (11.1+/-4.2 nmol/ml, p=0.004). Serum folate and vitamin B12 levels were not correlated with the plasma homocysteine levels. In conclusion, even though homozygosity for the VV genotype of the MTHFR gene was associated with higher plasma homocysteine levels, we found no association between plasma levels of homocysteine and DVT or between the genotype of the MTHFR gene and the DVT incidence. However, we found that the VV genotype of the MTHFR gene is a risk factor for DVT only when combined with the predisposition of thrombophilia.

Vascular endothelial cells synthesize and secrete brain-derived neurotrophic factor

Brain-derived neurotrophic factor (BDNF) is an abundant neurotrophin in brain and peripheral nerves, where it affects neural development, survival and repair after injury. BDNF has been detected in rat and human blood, but the source of circulating BDNF is not established. BDNF messenger and peptide were detected in cultured cells and in the culture medium of human umbilical vein endothelial cells. The expression of BDNF was up-regulated by elevation of intracellular cAMP and down-regulated by Ca(2+) ionophore, bovine brain extract and laminar fluid shear stress. These results suggest that vascular endothelial cells may contribute to circulating BDNF.

The effect of apoptosis inhibitors on experimental autoimmune encephalomyelitis: apoptosis as a regulatory factor

The effect of apoptosis inhibitors on experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis, was investigated by intraperitoneal or intracisternal administration of apoptosis inhibitors Ac-YVAD-cmk and zVAD-fmk. After onset of the disease, these agents had no suppressive effect on EAE and resulted in impaired recovery or earlier relapse. Histological examination revealed that administration of zVAD-fmk suppressed the apoptotic death of inflammatory cells in the central nervous system (CNS) of mice with EAE. The results indicated that the apoptotic elimination of infiltrated cells in the CNS might be one of the recovery mechanisms in EAE.

[An autopsy case of malignant lymphoma who showed hearing loss and cavernous sinus syndrome in the first stage and hemophagocytic syndrome]

A 48-year-old man was admitted to our hospital due to multiple cranial neuropathy such as vertigo, hearing loss of the left ear, visual loss of the left eye, left ptosis and total ophthalmoplegia of the left eye. Brain MRI revealed no abnormalities. After 10 days, he suddenly showed hemophagocytic syndrome with high fever, liver dysfunction, jaundice and pancytopenia. In spite of the treatment, he died of multiple organ failure after 26 days. At autopsy, malignant lymphoma cells of T cell origin directly invaded into the liver, spleen, intraperitoneal lymph nodes and other organs. Reports that direct invasion of lymphoma cells could be detected at the cranial nerves in the cavernous sinus are very rare.

Molecular cloning of Saccharomyces cerevisiae MGC1/YDR473c gene which is essential for cell growth

Saccharomyces cerevisiae haploid cells undergo morphological changes in response to mating pheromones, a- and alpha-factors, during sexual conjugation. As a first step to elucidate the mechanism, I had previously identified the mgc1 mutation which affected the morphogenesis induced by mating pheromones. The mutation had been designated mgc1 for morphogenesis control. In the present study I cloned the MGC1 gene. Sequencing analysis indicates that the MGC1 gene corresponds to the YDR473c gene. The MGC1 gene was shown to be essential for cell growth and required for the transition from the G1 to S phase of cell cycle. Protein-protein interaction of Mgc1 protein was shown by using yeast two-hybrid system. Mgc1 protein was also proposed to be localized in the nucleus in yeast cells.

IL-6 plays a crucial role in the induction phase of myelin oligodendrocyte glucoprotein 35-55 induced experimental autoimmune encephalomyelitis

We investigated the role of IL-6 in myelin oligodendrocyte glycoprotein (MOG) peptide induced experimental autoimmune encephalomyelitis (EAE) using IL-6-deficient mice and found that IL-6-deficient mice were resistant to active induction of EAE, but that the treatment of those mice with IL-6 during the preclinical phase caused typical EAE. We also found that both wild-type and IL-6-deficient mice were resistant to passive transfer of EAE by lymphocytes from IL-6-deficient mice, but that passive transfer of lymphocytes from wild-type mice induced typical EAE in IL-6-deficient mice. Histological abnormalities of the central nervous system (CNS) in those IL-6-deficient mice with EAE were similar to those in wild-type mice with EAE. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed no difference in the production of inflammatory cytokines such as IL-1beta, IL-2, TNF-alpha, and IFN-gamma in the CNS of IL-6-deficient mice with EAE as compared to the CNS of wild-type mice with EAE. These results indicated that IL-6 might be an important factor in the induction phase, but might have little influence on the effector phase of EAE. We further estimated the production of cytokines in MOG-stimulated lymph node (LN) cells by enzyme-linked immunosorbent assay. Increased IL-4 and IL-10 production and reduced IL-2 and IFN-gamma production were observed in LN cells from IL-6-deficient mice as compared to LN cells from wild-type mice. These results suggested that a shift of T cell responses from Thl to Th2 might explain the resistance of IL-6-deficient mice to EAE. Taken together, IL-6 may play a crucial role in the induction phase of EAE by modulating Th1/Th2 balance.

Expression and secretion of a biologically active mouse sonic hedgehog protein by the methylotrophic yeast Pichia pastoris

We have successfully secreted the amino-terminal functional domain of mouse sonic hedgehog protein (SHH) into culture fluid using a yeast Pichia pastoris expression system. A cDNA fragment encoding the amino-terminal domain of mouse SHH was inserted downstream of the Saccharomyces cerevisiae alpha-mating factor secretion signal. The DNA fragment was introduced into the host genome by the spheroplast transformation method. Transformants were selected based on their resistance to G418: His+ transformants which showed resistance to over 8 mg G418/ml were selected and analyzed for determination of the plasmid copy number. One His+ clone which has eight copies of the expression cassette per genome was cultured in minimal medium deficient for histidine, and further cultured in buffered medium supplemented with methanol which activates the AOX1 promoter. SDS-PAGE analysis indicated efficient expression and secretion of mouse SHH into culture fluid. The yield of secreted SHH was estimated to be 50 micrograms/ml. Purified protein was assayed for biological activity and found to activate the transcription of the Patched genes (Ptc-1 and Ptc-2) encoding receptors for SHH.

Undetectable dystrophin can still result in a relatively benign phenotype of dystrophinopathy

We present here a 28-year-old male patient with Becker muscular dystrophy whose skeletal muscle showed an absence of dystrophin. He has had progressive and predominantly proximal muscular wasting since 5 years of age, but was able to walk until 26 years of age. He showed hypertrophic calves, cardiomyopathy, and an elevated serum creatine kinase level (934 U/1). A skeletal muscle biopsy revealed advanced chronic myopathic changes. Immunohistochemical examination using anti-dystrophin antibodies against C-terminus showed deficiency of the protein. Rod domain and N-terminus were also absent in almost all muscle fibers, but only in a small part of the sample, they were faintly stained. beta-Dystroglycan and utrophin were present only in a small number of muscle fibers. DNA and RT-PCR analysis showed a frame-shift deletion of exons 3-7 in the dystrophin gene. In such an exceptional case as this one, it is important to investigate the factors which determine the severity of dystrophinopathy.

Cell-cell recognition and pheromone response of the yeast Saccharomyces globosus

Sexual agglutination and pheromone interaction between cells of two mating types, a and alpha, in the yeast Saccharomyces globosus were studied. S. globosus was shown to produce mating-type-specific factors analogs to a- and alpha-mating pheromones of Saccharomyces cerevisiae and to undergo the sexual agglutination reaction between cells of two mating types. While the sexual agglutination of cells of different species was not observed, mating type a cells of each species were shown to respond to alpha-factors produced by the other species. Thus, the mating response of S. globosus was shown to be identical to what has been observed in two other species of the same genera: S. cerevisiae and Saccharomyces kluyveri.

Angiotensin II plays a pathogenic role in immune-mediated renal injury in mice

Several lines of evidence show the importance of angiotensin II (AII) in renal injuries, especially when hemodynamic abnormalities are involved. To elucidate the role of AII in immune-mediated renal injury, we studied anti-glomerular basement membrane (GBM) nephritis in AII type 1a receptor (AT1a)-deficient homozygous (AT1a-/-) and wild-type (AT1a+/+) mice. A transient activation of the renin-angiotensin system (RAS) was observed in both groups of mice at around day 1. A renal expression of monocyte chemoattractant protein-1 (MCP-1) was transiently induced at six hours in both groups, which was then downregulated at day 1. In the AT1a+/+ mice, after RAS activation, the glomerular expression of MCP-1 was exacerbated at days 7 and 14. Thereafter, severe proteinuria developed, and the renal expressions of transforming growth factor-beta1 (TGF-beta1) and collagen type I increased, resulting in severe glomerulosclerosis and interstitial fibrosis. In contrast, glomerular expression of MCP-1, proteinuria, and tissue damage were markedly ameliorated in the AT1a-/- mice. Because this amelioration is likely due to the lack of AT1a, we can conclude that AII action, mediated by AT1a, plays a pathogenic role in anti-GBM nephritis, in which AII may contribute to the exacerbation of glomerular MCP-1 expression. These results suggest the involvement of AII in immune-mediated renal injuries.

Ibudilast, a phosphodiesterase inhibitor, ameliorates experimental autoimmune encephalomyelitis in Dark August rats

A phosphodiesterase inhibitor (PDEI), Ibudilast, which has been in wide use for the management of bronchial asthma and cerebrovascular disease in Japan, was tested for its clinical efficacy on experimental autoimmune encephalomyelitis (EAE) in Dark August rats. The severity of acute EAE was significantly ameliorated by prophylactic oral treatment with Ibudilast (10 mg/kg per day) starting on the day of immunization, although it did not modify the course of the disease when it was given after the onset of the first clinical sign of EAE. Histologically, inflammatory cell infiltration in the lumbar spinal cord was significantly reduced in Ibudilast-treated animals as compared to control animals. Ibudilast mildly suppressed MBP-induced proliferation of T cells in regional lymph nodes, the secretion of interferon-gamma from T cells activated by MBP in CFA, and the secretion of tumor necrosis factor-alpha from macrophages. While the in vitro studies did not suggest difference between Ibudilast and other PDEIs such as rolipram, the clinical dose of Ibudilast is approximately 200-fold higher than that of rolipram and the effective dose of Ibudilast was relatively close to what has been therapeutically used in patients. Thus, Ibudilast may be a candidate for clinical use for patients with multiple sclerosis. 1999 Elsevier Science B.V. All rights reserved.

Immunological localization and ontogenetic development of inhibin alpha subunit in rat brain

This study examined the immunolocalization and ontogeny of the inhibin-specific alpha subunit in the brain of male rats. Immunohistochemistry using antiserum directed against the mature region of porcine inhibin alpha (1-19, Tyr20) revealed positive reactions in process-bearing cells resembling astroglia in several regions, especially in the dorsal region of the third ventricle, medial and ventral arcuate nucleus, hippocampal dentate gyrus, and layers 1-3 of the cerebral cortex. Generally, inhibin alpha-positive cells in the limbic cortex had larger cell bodies and longer processes than those in the hypothalamus. These inhibin alpha-positive cells were verified to be positive for glial fibrillary acidic protein (GFAP), a differentiated astroglial marker, by double immunolabelling. The expression of inhibin alpha mRNA was higher in the brains of neonatal rats than in those of adult rats, as revealed by reverse transcription-competitive polymerase chain reaction, although the similar changes of immunoreactive inhibin alpha subunit in the brain was not observed. Orchiectomy did not affect expression of inhibin alpha mRNA in the hypothalamic area. This study suggests that inhibin-related peptide is produced by differentiated astrocytes, especially in the hypothalamic arcuate nucleus, the hippocampal dentate gyrus, and the cerebral cortex, and that the expression of inhibin alpha is regulated during brain development.

Involvement of angiotensin II in development of spontaneous nephrosis in Dahl salt-sensitive rats

We investigated the effect of angiotensin-converting enzyme inhibition on spontaneous nephrosis in Dahl salt-sensitive (Dahl/S) rats. Dahl/S rats fed on a normal sodium diet spontaneously developed nephrosis and mild hypertension from a young age. In young Dahl/S rats, an angiotensin-converting enzyme inhibitor, imidapril, attenuated the development of proteinuria accompanied by a decrease in blood pressure. Methylprednisolone, a potent therapeutic agent for proteinuria, did not affect the development of nephrosis. An angiotensin AT1 receptor antagonist, losartan, but not a Ca2+ channel blocker, verapamil, inhibited the development of nephrosis while both agents decreased blood pressure to a similar extent as imidapril. In mature Dahl/S rats, imidapril suppressed not only the development of proteinuria but also the glomerular lesions. It is concluded that the development of spontaneous nephrosis in Dahl/S rats is mediated by angiotensin II.

[An autopsy case of Degos' disease with ascending thoracic myelopathy]

Degos' disease is a rare multisystem vasculopathy of unknown etiology. We report a 44-year-old man who presented himself with gait and sensory disturbances mainly due to thoracic transverse myelopathy four years after the appearance of many characteristic umbilicated papules over the trunk and extremities. He did not complain of abdominal pain or discomfort. Laboratory, electrophysiological and imaging studies did not show any characteristic change, except for the increase of protein contents and cell counts in the cerebrospinal fluid. We tried methylprednisolone pulse-dose therapy (1,000 mg/day x 3 days) five times, but this patient's neurological condition worsened stepwise after it, although the appearance of new skin lesion was suppressed. Intravenous infusion of ozagrel sodium and cyclophosphamide (1,000 mg/day) were also ineffective, and this patient died of respiratory failure after showing oculomotor paresis and comatose state. Necropsy revealed Degos' disease-specific vasculopathy in the central nervous system and the gastrointestinal tract, where occlusions of small-sized arteries and veins due to the intimal thickening were evident. The tissue necrosis was macroscopically remarkable in the brainstem and the thoracic spinal cord. The efficacy of steroid therapy for this disease should be investigated more carefully.

[The inhibitory effect and the mechanism of ethanol absorption by L-carnosine zinc complex in mouse gastrointestinal tract]

The effect of L-carnosine-zinc complex(Car-Zn) on ethanol absorption was investigated after oral administration(adm) to mice. One hour after oral adm of Car-Zn, and 14C-ethanol was given orally or intraperitoneally(i.p.). After passage of time, the blood was drawn from the tail vein, and 14C-radioactivities determined. The Car-Zn showed a dose-dependent inhibition of the appearance of 14C-radioactivities in blood following oral 14C-ethanol loading, while Zn acetate did not induce any alteration as compared with control. Car-Zn pretreatment did not induce any change in the blood 14C-radioactivity when ethanol was given i.p. The 14C-radioactivity and zinc in gastrointestinal tract after oral adm of Car-Zn and 14C-ethanol showed significantly higher levels than those of control for 7 hr. Distribution of 14C-radioactivities in other organs of Car-Zn treated mice were lower than those of control 3 hr after adm, while it was similar or higher than those of control 7 hr after adm. The excretions of 14C-radioactivity through expiration in Car-Zn group was a lower than that of control. Also, the urinary and fecal excretions of 14C-radioactivity were low values at 5.0% and 0.5% of the administered dose 72 hr after adm, respectively. Also, the 14C-radioactivities remaining in the organs did not detect or were very low values. In vitro study, Car-Zn stimulated the metabolism of ethanol to acetaldehyde and acetic acid in 9,000 g supernatant of small intestine. The major route of excretions of 14C-radioactivity may be excreted into the expired air. The results suggest that Car-Zn shows a long-term adhesive and permeable action on gastrointestinal tract in the mouse; as a result, this may inhibited ethanol absorption.

Growth inhibition of Saccharomyces cerevisiae by the immunosuppressant leflunomide is due to the inhibition of uracil uptake via Fur4p

The immunosuppressant leflunomide inhibits cytokine-stimulated proliferation of lymphoid cells in vitro and also inhibits the growth of the eukaryotic microorganism Saccharomyces cerevisiae. To elucidate the molecular mechanism of action of the drug, two yeast genes which suppress the anti-proliferative effect when present in multiple copies were cloned and designated MLF1 and MLF2 for multicopy suppressor of leflunomide sensitivity. DNA sequencing analysis revealed that the MLF1 gene is identical to the FUR4 gene, which encodes a uracil permease and functions to import uracil efficiently. The MLF2 was found to be identical to the URA3 gene. Excess exogenous uracil also overcomes the anti-proliferative effect of leflunomide on yeast cells. Uracil prototrophy also conferred resistance to leflunomide. Uracil uptake was inhibited by leflunomide. Thus, the growth inhibition by leflunomide seen in a S. cerevisiae ura3 auxotroph is due to the inhibition of the entry of exogenous uracil via the Fur4 uracil permease.

Diagnostic value of plasma thrombin-antithrombin III complex and D-dimer concentration in patients with varicose veins for exclusion of deep-vein thrombosis

The aim of this study was to evaluate the usefulness of determining plasma D-dimer (DD) and thrombin-antithrombin III complex (TAT) levels in the diagnostic workup for the screening of deep-venous thrombosis (DVT) among varicose vein patients. One hundred forty consecutive patients being treated for DVT or varicose veins underwent color-flow duplex scanning, and 25 patients had DVT and the remaining 115 had primary varicose veins. When DD and TAT were analyzed statistically in combination, it was determined that the combination of either positive DD (cutoff level 1.0 microg/ml) or positive TAT (cutoff level 3.0 microg/l) had a sensitivity of 100% for DVT with a specificity, positive predictive value, and negative predictive value of 79%, 51%, and 100%, respectively. This study demonstrates plasma levels of DD (less than 1.0 microg/ml) and TAT (less than 3.0 microg/l) in combination to be useful for the exclusion of DVT among patients with varicose veins. Patients with negative hematological data may safely undergo surgical treatment for varicose veins without further evaluation such as duplex scanning or contrast venography.

A case of Kearns-Sayre syndrome showing a constant proportion of deleted mitochondrial DNA in blood cells during 6 years of follow-up

Kearns-Sayre syndrome (KSS) and Pearson syndrome (PS) show quite different phenotypes despite the same underlying genetic defect, i.e. a large deletion of one population of mitochondrial (mt) DNA. The main feature of KSS is progressive encephalomyopathy; on the other hand, PS shows fatal hematological problems in early infancy. Through Southern blot analysis of mtDNA of blood cells, deletion has been consistently found in patients with PS but usually undetectable in KSS patients. Therefore, their different clinical phenotypes have been explained by the different tissue distribution of mutant mtDNA. Recently, a few cases were reported which had features of PS in infancy and later developed KSS. These observations suggest that phenotypes may also be modified by the selection process involving mtDNA within different tissues. We found a case of KSS, who initially presented endocrinological dysfunction such as insulin-dependent diabetes mellitus (IDDM) and growth hormone (GH) deficiency, and had not developed external ophthalmoplegia until the age of 17. Although he did not show any symptoms of PS, a marked proportion of mtDNA was deleted not only in muscle but also in blood cells. Analysis of his blood cells showed an unchanged proportion of deleted mtDNA at three estimations within 6 years of the follow-up period. This case provides evidence that deleted mtDNA in blood cells also has a stable replicative capacity and that a large proportion of deleted mtDNA in blood cells may not accompany hematological problems.