[Spinal multiple sclerosis mimicking a spinal cord tumor: a case report]

Since the advent of magnetic resonance imaging (MRI), to visualize lesions of multiple sclerosis has become easy to do. However, in some cases with primary spinal cord multiple sclerosis, it is not always easy to obtain a diagnosis in the first instance. We reported a case of primary spinal multiple sclerosis diagnosed through histological examination of a surgical specimen taken by an open biopsy. A 35-year-old woman was admitted with complaints of two-months duration of progressive weakness and sensory disturbance in the legs and buttocks. On radiological examinations including metrizamide CT myelography and MRI, enlargement of the conus medullaris was the only positive finding. Respective to her clinical course, intramedullary spinal cord tumor could not be ruled out, so an open biopsy was performed. Histological examination revealed that the cord lesion was acute demyelination with perivascular inflammation. Her neurological signs were almost completely cured with administration of corticosteroid, though new brainstem signs took place two months later and then a concrete diagnosis of her having multiple sclerosis was finally achieved. Since preoperative examinations can not differentiate spinal cord tumor from any other intramedullary cord lesions such as demyelinating foci of multiple sclerosis, surgical intervention would be approved in such atypical primary spinal cord multiple sclerosis.

Isolation and functional identification of a novel cDNA for astaxanthin biosynthesis from Haematococcus pluvialis, and astaxanthin synthesis in Escherichia coli

We succeeded in isolating a novel cDNA involved in astaxanthin biosynthesis from the green alga Haematococcus pluvialis, by an expression cloning method using an Escherichia coli transformant as a host that synthesizes beta-carotene due to the Erwinia uredovora carotenoid biosynthesis genes. The cloned cDNA was shown to encode a novel enzyme, beta-carotene ketolase (beta-carotene oxygenase), which converted beta-carotene to canthaxanthin via echinenone, through chromatographic and spectroscopic analysis of the pigments accumulated in an E. coli transformant. This indicates that the encoded enzyme is responsible for the direct conversion of methylene to keto groups, a mechanism that usually requires two different enzymatic reactions proceeding via a hydroxy intermediate. Northern blot analysis showed that the mRNA was synthesized only in the cyst cells of H. pluvialis. E. coli carrying the H. pluvialis cDNA and the E. uredovora genes required for zeaxanthin biosynthesis was also found to synthesize astaxanthin (3S, 3'S), which was identified after purification by a variety of spectroscopic methods.

Pulmonary sarcoidosis: population differences and pathophysiology

Sarcoidosis is characterized as a hyperimmune response to an unknown agent(s) at the lesion sites. Regarding pulmonary lesions, macrophage-T lymphocyte alveolitis precedes an epithelioid cell granuloma formation. In the 35 years since the first International Conference on Sarcoidosis, the definition of sarcoidosis has been revised several times, and many new pathophysiologic mechanisms have been proposed. In this review, we focused on four important issues: (1) possible population differences, (2) possible causative agent(s) and the current problems of disease susceptibility or resistance, (3) recent data on pathogenesis (including a genetic approach) and pathophysiologic processes, and (4) monitoring of disease activity.

CT and pathological correlation of pulmonary sarcoidosis

In CT the presence of mediastinal or hilar lymphadenopathies and thickened bronchovascular bundles are landmarks for the diagnosis of pulmonary sarcoidosis. The major CT findings for parenchymal involvement are thickened bronchovascular bundles, large parenchymal nodules, pleural or subpleural nodules, ground-glass opacities, local lung volume loss (distortion of the lung parenchyma), and microscopic and macroscopic honeycombing. The thickened bronchovascular bundles correspond histologically to granulomas, either with or without perigranulomatous fibrosis in the connective tissue sheath around the pulmonary vessels and airways. Conglomerate granulomas are represented on CT by high-attenuation nodules, and the ground-glass opacities are caused by the summation of a number of small granulomas in the interstitium.

Gastrointestinal and skin lesions in piglets naturally infected with pseudorabies virus

Pseudorabies virus (PRV) infection was diagnosed in 4 piglets from a litter by immunohistopathologic examination and virus isolation. Three piglets had moderate to severe neuronal degeneration, and PRV antigen was detected in Auerbach's myenteric plexus and Meissner's submucosal plexus of the gastrointestinal tract. One piglet had 2 types of skin lesions. One lesion appeared on the hip and ear and was characterized by ballooning degeneration, necrosis of epithelial cells, and intranuclear inclusion bodies. The other was found on the ear and hematoma-like lesion was composed of fibrinoid exudation and degenerative connective tissue. PRV antigen was clearly demonstrated in both skin lesions. These results suggested that degeneration of myenteric plexuses might be another characteristic of lesions in PRV-infected pigs and that the virus spreads by interaction between the skin and myenteric plexuses to the central nervous system.

Secretion of MPB64 antigen by a recombinant clone of Mycobacterium smegmatis: characterization and application for the diagnosis of tuberculosis

MPB64, a specific antigen to Mycobacterium tuberculosis complex (TB complex), was produced and secreted by a clone of M. smegmatis-MPB64 where the structural gene of MPB64 was inserted using a new mycobacteria, E. coli shuttle plasmid pNIS vector. Antibodies against the recombinant MPB64 (rMPB64) were used for the reverse particle latex agglutination (RPLA) test to detect the MPB64 antigen rapidly. RPLA tests were applied to the shock cultures and the clinical isolates of mycobacteria to identify TB complex. RPLA with anti-MPB64 antibody-coated latex beads completely distinguished TB complex from other mycobacteria. Thus, it is suggested that RPLA with anti-MPB64 antibody would be a new, easy and inexpensive method for the rapid diagnosis of tuberculosis.

[Study on surfactin, a cyclic depsipeptide. I. Isolation and structure of eight surfuctin analogs produced by Bacillus natto KMD 2311]

Crude surfactin was simply prepared from the culture filtrate of Bacillus natto KMD 2311 twice by acidification of the filtrate and extraction of the precipitate with ethanol. Eight surfactin analogs were isolated from the crude surfactin by RP-HPLC and gel filtration. The structure of each analog was deduced by means of amino acid composition of the acid hydrolysate and FAB-MS measurement to be a cyclic depsipeptide containing a hydroxyfatty acid. The structure of the hydroxyfatty acid moieties was elucidated as n- or iso- or anteiso-3-hydroxyfatty acid composed of carbon number 13-16 by GC analysis and EI-MS after the methanolysis of the analogs. The amino acid sequence of the peptide portion was assigned as acyl-Glu-Leu-Leu-Val-Asp-Leu-Leu by EI-MS for eight analogs. The isolated four compounds were found to be identical with the known surfactin analogs, A1, B1, B2 and C1. Although surfactin A2 and C2 had not been isolated, their structures were deduced to be a surfactin analog. Surfactin A3 and D were novel analogs. The acyl groups of surfactin A2, A3, C2 and D were anteiso-3-hydroxytridecanoic acid, n-3-hydroxytridecanoic acid, anteiso-3-hydroxypentadecanoic acid and iso-3-hydroxyhexadecanoic acid, respectively.

Pulmonary sarcoidosis: pathogenesis and population differences

Sarcoidosis is a systemic disease. Clinical manifestations and prognosis are heterogeneous in sarcoidosis patients from various populations. This suggests that genetic factors and/or environmental factors seem to play important roles in the pathogenesis. Sarcoidosis is characterized as a hyperimmune response to unknown agent(s) at the lesion sites. Regarding pulmonary lesions, macrophage-T lymphocyte alveolitis precedes epithelioid cell granuloma formation. In this review, reports presented in international meetings were introduced to compare population differences; we attempted to review the issues which relate to disease susceptibility in patients with sarcoidosis. In addition, we discussed the possible causative agents, whether T cell receptor expression reflects antigen driven immune responses, and what type of biological active materials may be critical in determining the disease activity and/or prognostic factors, with particular focus on the population differences.

A novel factor, TA20, involved in neuronal differentiation: cDNA cloning and expression

Combined treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) and dibutyryl cyclic AMP (diBu-cAMP) induced significantly longer neurites than treatment with each alone in NG108-15 cells. We performed differential screening to identify genes expressed only by treatment with TPA plus diBu-cAMP but not by that with diBu-cAMP for 72 h alone in NG108-15 cells, and isolated a novel gene, TA20. Over-expression of the gene in NG108-15 and neuroblastoma N18TG-2 cells caused intense neurite elongation and suppressed cell growth. TA20 did not cause, however, any morphological changes in glioma C6Bu-1 cells. These results suggest that TA20 is a novel neuronal differentiation factor.

Coronary artery disease in dermatomyositis. A case report

A sixty-two-year-old woman with chronic dermatomyositis (DM) receiving steroid monotherapy developed coronary artery stenosis. She had lung fibrosis and complained of dyspnea, but no ischemia was suggested by electrocardiogram. Ateriographic findings and clinical symptoms of coronary artery disease in DM have not been previously reported.

Homology between the MPB70 and MPB83 proteins of Mycobacterium bovis BCG

Isolation of MPB83 from Mycobacterium bovis BCG Tokyo culture fluid is described. MPB70 and MPB83 have similar molecular mass as judged by SDS-PAGE but differ in isoelectric points. Peptides isolated after CNBr cleavage of MPB83 revealed extensive homology as well as distinct differences from corresponding parts of the amino acid sequence deduced from the mpb70 gene cloned by Terasaka et al. Antibodies produced by immunization with MPB70 and MPB83 had distinctly different fine specificity revealing cross-reactivity between the proteins. These findings indicate that two distinct, homologous genes code for these proteins. Sensitization with live BCG Tokyo also induced T cell responses to MPB83 with development of delayed type hypersensitivity in guinea pigs.

Establishment and characterization of human gastric and colonic xenograft lines resistant to CPT-11 (a new derivative of camptothecin)

CPT-11-resistant human gastric and colonic xenograft lines were established by direct intratumoral injection of CPT-11 into subcutaneous SC-1-NU and CC-2-NU tumors in nude mice once a week for 10 months. The resistance of these xenograft lines to CPT-11 was confirmed by growth inhibition rate, to be 36.3% and 45.4%, respectively, compared to each parent cell line. DNA topoisomerase I activity of the nuclear extracts of SC-1-NU/CPT-11 and CC-2-NU/CPT-11, as assayed by relaxation of supercoiled DNA Col-E1, was significantly less than those of the parent lines. The cellular levels of topoisomerase I in those resistant lines measured by Western blot analysis were 0.57- and 0.79-fold lower than those of the parental lines, respectively. However, the activity of DNA topoisomerase II of those resistant cell lines assayed by decatenation of kinetoplast DNA was higher than that of the parental lines and the cellular levels of topoisomerase II in the resistant lines measured by Western blot analysis were 10.8- and 8.1-fold higher than those of the parent lines. Intracellular accumulation of CPT-11 in CPT-11-resistant tumors was not changed as compared to that of the parental lines, but hydrolysis of CPT-11 to more active SN-38 was reduced in the resistant tumors.

Purification and characterization of a low-molecular-mass T-cell antigen secreted by Mycobacterium tuberculosis

A novel immunogenic antigen, the 6-kDa early secretory antigenic target (ESAT-6), from short-term culture filtrates of Mycobacterium tuberculosis was purified by hydrophobic interaction chromatography and anion-exchange chromatography by use of fast protein liquid chromatography. The antigen focused at two different pIs of 4.0 and 4.5 during isoelectric focusing, and each of these components separated into three spots ranging from 4 to 6 kDa during two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The apparent differences in molecular masses or pIs of these isoforms were not due to posttranslational glycosylation. The molecular weight of the purified native protein was determined by applying gel filtration and nondenaturing polyacrylamide gel electrophoresis and found to be 24 kDa. ESAT-6 is recognized by the murine monoclonal antibody HYB 76-8, which was used to screen a recombinant lambda gt11 M. tuberculosis DNA library. A phage expressing a gene product recognized by HYB 76-8 was isolated, and a 1.7-kbp fragment of the mycobacterial DNA insert was sequenced. The structural gene of ESAT-6 was identified as the sequence encoding a polypeptide of 95 amino acids. The N terminus of the deduced sequence could be aligned with the 10 amino-terminal amino acids derived from sequence analyses of the native protein. N-terminal sequence analysis showed that the purified antigen was essentially free from contaminants, and the amino acid analysis of the antigen was in good agreement with the DNA sequence-deduced amino acid composition. Thus, the heterogeneities observed in the pI and molecular weight of the purified antigen do not derive from contaminating proteins but are most likely due to heterogeneity of the antigen itself. Native and recombinant ESAT-6 are immunologically active in that both elicited a high release of gamma interferon from T cells isolated from memory-immune mice challenged with M. tuberculosis. Analyses of subcellular fractions of M. tuberculosis showed the presence of ESAT-6 in cytosol- and cell wall-containing fractions. Interspecies analyses showed the presence of ESAT-6 in filtrates from M. tuberculosis complex species. Among filtrates from mycobacteria not belonging to the M. tuberculosis complex, reactivity was observed in Mycobacterium kansasii, Mycobacterium szulgai, and Mycobacterium marinum.

Recall of long-lived immunity to Mycobacterium tuberculosis infection in mice

Our study investigates the recall of immunity in the mouse model of memory immunity to tuberculosis infection. The results provide evidence that recall of immunity is expressed as an accelerated accumulation of potent effector cells in the infected target organs. These effector cells were recruited from the resting pool of memory cells and were immediately triggered to exert their effector functions, leading to a massive release of Th1 cytokines detectable both in splenic extracts and in the serum within the first 24 h of infection. During a primary infection, in contrast, a 14-day delay was observed before significant cytokine levels were reached. After the initial effector phase, the cells blasted and entered into clonal expansion, resulting in a rapid increase in the total number of CD4 CD45RBlow cells in the spleen. The recall of memory immunity was highly efficient and controlled an infectious challenge within the first week. The molecules recognized by the memory effector subset were the proteins secreted from Mycobacterium tuberculosis during growth. By separating the CD4 population into CD45RBhigh and CD45RBlow subsets, the memory effector cells were demonstrated to reside predominantly in the activated population of CD45RBlow CD44high LFA-1high L-selectinlow cells. The key antigenic targets recognized by these cells were identified as Ag85B and a secreted 6-kDa protein (ESAT-6) that elicited the release of exceedingly high levels of IFN-gamma. ESAT-6 was biochemically purified, characterized, and the gene encoding the protein was cloned.

Recall of long-lived immunity to Mycobacterium tuberculosis infection in mice

Our study investigates the recall of immunity in the mouse model of memory immunity to tuberculosis infection. The results provide evidence that recall of immunity is expressed as an accelerated accumulation of potent effector cells in the infected target organs. These effector cells were recruited from the resting pool of memory cells and were immediately triggered to exert their effector functions, leading to a massive release of Th1 cytokines detectable both in splenic extracts and in the serum within the first 24 h of infection. During a primary infection, in contrast, a 14-day delay was observed before significant cytokine levels were reached. After the initial effector phase, the cells blasted and entered into clonal expansion, resulting in a rapid increase in the total number of CD4 CD45RBlow cells in the spleen. The recall of memory immunity was highly efficient and controlled an infectious challenge within the first week. The molecules recognized by the memory effector subset were the proteins secreted from Mycobacterium tuberculosis during growth. By separating the CD4 population into CD45RBhigh and CD45RBlow subsets, the memory effector cells were demonstrated to reside predominantly in the activated population of CD45RBlow CD44high LFA-1high L-selectinlow cells. The key antigenic targets recognized by these cells were identified as Ag85B and a secreted 6-kDa protein (ESAT-6) that elicited the release of exceedingly high levels of IFN-gamma. ESAT-6 was biochemically purified, characterized, and the gene encoding the protein was cloned.

Pharmacological study of stem-cell-factor-induced mast cell histamine release with kinase inhibitors

Stem cell factor (SCF) is a ligand for c-kit receptor and has a critical role in the development of mast cells. In this study, we investigated the effect of a panel of kinase inhibitors on SCF-induced histamine release from rat peritoneal mast cells. Genistein, an inhibitor of tyrosine kinases, inhibited SCF-induced histamine release with IC50 of 1.6 x 10(-5) M. Wortmannin, an inhibitor of phosphatidylinositol 3'-kinase (PI3 kinase), inhibited histamine release stimulated with SCF dose-dependently with IC50 of 4 x 10(-9) M. KT5926, an inhibitor of myosin light chain (MLC) kinase, reduced histamine release with IC50 of 1.8 x 10(-7) M. Staurosporine, an inhibitor of protein kinases, also inhibited SCF-induced histamine release with IC50 of 6.5 x 10(-8) M. These results show the early involvement of tyrosine kinase and PI3 kinase and the possible role of MLC kinase in the late secretory phase in the signaling pathway used by SCF.

Guinea pig cellular immune responses to proteins secreted by Mycobacterium tuberculosis

To study the immunological activity of proteins secreted by Mycobacterium tuberculosis, we carried out comparative studies in guinea pigs infected intravenously with 2.5 x 10(3) CFU of this organism or with 2.5 x 10(4) CFU of Mycobacterium bovis BCG. Groups of infected guinea pigs were skin tested with fractions of secreted proteins covering well-defined narrow-molecular-mass regions, or such fractions were used for lymphocyte stimulation experiments. The lymphocyte stimulation experiments showed that the fraction containing proteins with molecular masses below 10 kDa had a superior stimulating capacity in tuberculous guinea pigs whereas the 24- to 30-kDa fraction gave significantly higher skin reactions in this group compared with BCG-vaccinated guinea pigs. A precise mapping within the region from 23 to 35 kDa by using a combination of narrow overlapping fractions and purified proteins enabled the identification of the 24-kDa antigen MPT64 as a molecule specific for tuberculous infection. Thus, MPT64 is a promising candidate for a specific diagnostic skin test reagent for human tuberculosis.

Analysis of fused-membrane structures in bronchoalveolar lavage fluid from patients with alveolar proteinosis

Alveolar macrophages of patients with alveolar proteinosis, obtained by lung lavage, contain a large number of intracytoplasmic inclusions with mutlilamellar membranous structures, called fused-membrane structures, having a periodicity of 4.7 nm. To analyze the composition of these structures, we concentrated them from the bronchoalveolar lavage fluid of patients by a combination of sucrose density-gradient ultracentrifugation and enzyme hydrolysis using proteinase K. Fused-membrane structures were most numerous (26.2%) in a fraction obtained at the interface between 1.0 and 1.1 M sucrose solutions separated after proteinase K hydrolysis. This fraction was rich in acidic phospholipids. Hydrophobic surfactant apoproteins constituted about 77% of the proteins in this fraction, and a remarkable increase in the content of surfactant-associated protein C (SP-C) was found. The phospholipid-to-protein ratio was 0.25:1. Based on these results, we tried to reconstitute fused-membrane structures from purified lipids and hydrophobic proteins isolated from the patients' lavage fluid or from pig lungs. Only in the presence of both phospholipids and SP-C were similar multilamellar structures, having a periodicity of 4.3 to 4.5 nm, formed. These results suggest that fused-membrane structures have a close relationship to a hydrophobic surfactant-associated protein, SP-C, which accumulates in alveolar macrophages, possibly by incomplete digestion.

Delayed-type hypersensitivity to a recombinant mycobacterial antigen, MPB64, in guinea pigs sensitized to Mycobacterium tuberculosis or Mycobacterium bovis BCG

Recombinant MPB64 (rMPB64), a mycobacterial antigen, was obtained from an Escherichia coli clone transformed with a recombinant expression vector, pMAL64c. The rMPB64 was examined for the activity to elicit delayed-type hypersensitivity (DTH) in guinea pigs injected with liver Mycobacterium tuberculosis H37Rv or live M. bovis BCG Tokyo. It was found that rMPB64 has the same reactivity as native MPB64 (nMPB64) or MPT64 (nMPT64) and the potency to elicit DTH was 13.4 times higher than that of PPD. Because MPB64 is secreted only by living M. tuberculosis and some strains of BCG, it is possible to use this antigen for the diagnosis of tuberculosis.

[A case of leiomyosarcoma as a mediastinal tumor excised by bilateral thoracotomy]

Leiomyosarcoma as a mediastinal tumor is so rare that no more than 6 and 12 cases have so far been reported in and out Japan, respectively. The patient was 74-year-old male. While treated at the outpatient clinic of our university hospital for low back pain, he was referred to our department because of a shadow of the mediastinum on chest roentgenogram. A fist-sized tumor was found located in the posterior mediastinum behind the heart. Since it was difficult to make a preoperative definitive diagnosis, it was excised by bilateral thoracotomy. Histologically, it was compatible with sarcoma and a definitive diagnosis of leiomyosarcoma was made based on electron microscopic findings.

[Ultrasonographic diagnosis of athero- and arterio-sclerosis]

Modalities to depict atherosclerotic lesion, have recently been rich in approaches, such as angiography, computed tomography, ultrasonography, radionuclide imaging and magnetic resonance imaging. Although the angiography is still one of the gold standards for diagnosing athero- and arteriosclerotic changes, recent developments in interventional catheterization and medical treatments necessitate the detailed characterization of the vascular wall. High-frequency ultrasonography now expands the observation toward the structure and composition of the vascular wall which can not be obtained in angiography. The higher the frequency of ultrasound is, the better the resolution of the echo imaging improves. However, the adequate depth for echo observation from the probe becomes narrower with the increase of the probe frequency. Accordingly, we have to choose an adequate approach for the vessel of interest. For example, transesophageal echocardiography is useful to evaluate the atherosclerotic changes of the descending aorta. Peripheral ultrasonography is useful for the superficial arteries, including carotid arteries, femoral arteries and branchial arteries. The advantages of the peripheral body surface approach are non-invasiveness and repeatability. Intravascular ultrasonography requires invasive technique, but it provides novel information regarding the presence and the extent of atherosclerosis and its characterization such as calcification. Intravascular ultrasonography is a necessary modality for evaluating the effect of the directional coronary atherectomy.

T-cell receptor V gene expression in HLA-typed Japanese patients with pulmonary sarcoidosis

The clinical features of sarcoidosis vary in different ethnic groups, suggesting that different genetic or environmental backgrounds influence the disease. In Scandinavian sarcoidosis patients, we have previously described a correlation between lung-accumulated CD4+ T cells expressing the T-cell receptor (TCR) V alpha 2.3 gene segment and a particular HLA type (DR3[17],DQ2). For purposes of comparison, we have in this study investigated TCR V gene usage and gamma delta TCR expression in CD4+ and CD8+ T cells in bronchoalveolar lavage (BAL) fluid and peripheral blood in an ethnically distinct and homogenous group of individuals consisting of Japanese sarcoidosis patients and healthy controls. We used a panel of 13 monoclonal antibodies (Mab) specific for different TCR V genes, which altogether stained approximately 50% of the T cells, and triple staining techniques with flow cytometry. The patients and controls were also HLA-typed. Our results show a high degree of expression of gamma delta TCR in peripheral blood T cells of close to half of the patients. Expansions of T-cell subsets were readily detected in the CD8+ T-cell population, while a more homogenous staining pattern was found in the CD4+ T-cell population. These findings show the importance of ethnic origin and environment in discussions of TCR V gene usage.

Studies on chemical modification of monensin. V. Synthesis, sodium ion permeability, antibacterial activity, and crystal structure of 7-O-(4-substituted benzyl)monensins

7-O-(4-Substituted benzyl)monensins (3a-g) were synthesized from monensin (1), and their lipophilicity, antibacterial activity, and Na+ ion permeability were examined. 7-O-(4-Ethylbenzyl)monensin (3e) showed the largest Na+ ion permeability, but 3c,f,g showed smaller Na+ ion permeability than 7-O-benzylmonensin (2) in spite of higher lipophilicity. An X-ray study of the sodium salt of 3e revealed that the benzyl group was located over the position between the D and E rings, and that the ethyl substituent on the benzyl group was close to the C(28) methyl group on the E ring.