Recent advances in the structural biology of chondroitin sulfate and dermatan sulfate

Recent glycobiology studies have suggested fundamental biological functions for chondroitin, chondroitin sulfate and dermatan sulfate, which are widely distributed as glycosaminoglycan sidechains of proteoglycans in the extracellular matrix and at cell surfaces. They have been implicated in the signaling functions of various heparin-binding growth factors and chemokines, and play critical roles in the development of the central nervous system. They also function as receptors for various pathogens. These functions are closely associated with the sulfation patterns of the glycosaminoglycan chains. Surprisingly, nonsulfated chondroitin is indispensable in the morphogenesis and cell division of Caenorhabditis elegans, as revealed by RNA interference experiments of the recently cloned chondroitin synthase gene and by the analysis of mutants of squashed vulva genes.

Molecular cloning of a chondroitin polymerizing factor that cooperates with chondroitin synthase for chondroitin polymerization

We recently cloned human chondroitin synthase (ChSy) exhibiting the glucuronyltransferase-II (GlcATII) and N-acetylgalactosaminyltransferase-II (GalNAcTII) activities responsible for the biosynthesis of repeating disaccharide units of chondroitin sulfate, but chondroitin polymerization was not demonstrated in vitro using the recombinant ChSy. We report here that the chondroitin polymerizing activity requires concomitant expression of a novel protein designated chondroitin polymerizing factor (ChPF) with ChSy. The human ChPF consists of 775 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 23% identity to that of human ChSy. The expression of a soluble recombinant form of the protein in COS-1 cells produced a protein with little GlcAT-II or GalNAcT-II activity. In contrast, coexpression of the ChPF and ChSy yielded markedly augmented glycosyltransferase activities, whereas simple mixing of the two separately expressed proteins did not. Moreover, using both UDP-glucuronic acid (GlcUA) and UDP-N-acetylgalactosamine (GalNAc) as sugar donors, chondroitin polymerization was demonstrated on the so-called glycosaminoglycan-protein linkage region tetrasaccharide sequence of alpha-thrombomodulin. These results suggested that the ChPF acts as a specific activating factor for ChSy in chondroitin polymerization. The coding region of the ChPF was divided into four discrete exons and localized to chromosome 2q35-q36. Northern blot analysis revealed that the ChPF gene exhibited a markedly different expression pattern among various human tissues, which was similar to that of ChSy. Thus, the ChPF is required for chondroitin polymerizing activity of mammalian ChSy.

Self-reversal phenomena of toroidal current by reversing the external toroidal field in helicity-driven toroidal plasmas

In order to understand self-organization in helicity-driven systems, we have investigated the dynamics of low-aspect-ratio toroidal plasmas by decreasing the external toroidal field and reversing its sign in time. Consequently, we have discovered that the helicity-driven toroidal plasma relaxes towards the flipped state. Surprisingly, it has been observed that not only toroidal flux but also poloidal flux reverses sign spontaneously during the relaxation process. The self-reversal of the magnetic fields is attributed to the nonlinear growth of the n=1 kink instability of the central open flux.

Chondroitin proteoglycans are involved in cell division of Caenorhabditis elegans

Glycosaminoglycans such as heparan sulphate and chondroitin sulphate are extracellular sugar chains involved in intercellular signalling. Disruptions of genes encoding enzymes that mediate glycosaminoglycan biosynthesis have severe consequences in Drosophila and mice. Mutations in the Drosophila gene sugarless, which encodes a UDP-glucose dehydrogenase, impairs developmental signalling through the Wnt family member Wingless, and signalling by the fibroblast growth factor and Hedgehog pathways. Heparan sulphate is involved in these pathways, but little is known about the involvement of chondroitin. Undersulphated and oversulphated chondroitin sulphate chains have been implicated in other biological processes, however, including adhesion of erythrocytes infected with malaria parasite to human placenta and regulation of neural development. To investigate chondroitin functions, we cloned a chondroitin synthase homologue of Caenorhabditis elegans and depleted expression of its product by RNA-mediated interference and deletion mutagenesis. Here we report that blocking chondroitin synthesis results in cytokinesis defects in early embryogenesis. Reversion of cytokinesis is often observed in chondroitin-depleted embryos, and cell division eventually stops, resulting in early embryonic death. Our findings show that chondroitin is required for embryonic cytokinesis and cell division.

Molecular cloning and expression of a second chondroitin N-acetylgalactosaminyltransferase involved in the initiation and elongation of chondroitin/dermatan sulfate

We identified a novel human chondroitin N-acetylgalactosaminyltransferase, designated chondroitin GalNAcT-2 after a BLAST analysis of the GenBank(TM) data base using the sequence of a previously described human chondroitin N-acetylgalactosaminyltransferase (chondroitin GalNAcT-1) as a probe. The new cDNA sequence contained an open reading frame encoding a protein of 542 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 60% identity to that of human chondroitin GalNAcT-1. Like chondroitin GalNAcT-1, the expression of a soluble form of the protein in COS-1 cells produced an active enzyme, which not only transferred beta1,4-N-acetylgalactosamine (GalNAc) from UDP-[(3)H]GalNAc to a polymer chondroitin representing growing chondroitin chains (beta-GalNAc transferase II activity) but also to GlcUA beta 1-3Gal beta 1-O-C(2)H(4)NHCbz, a synthetic substrate for beta-GalNAc transferase I that transfers the first GalNAc to the core tetrasaccharide in the protein-linkage region of chondroitin sulfate. In contrast, the tetrasaccharide serine (GlcUA beta 1-3Gal beta 1-3Gal beta 1-4Xyl beta 1-O-Ser) derived from the linkage region, which is an inert acceptor substrate for chondroitin GalNAcT-1, served as an acceptor substrate. The coding region of this enzyme was divided into seven discrete exons, which is similar to the genomic organization of the chondroitin GalNAcT-1 gene, and was localized to chromosome 10q11.22. Northern blot analysis revealed that the chondroitin GalNAcT-2 gene exhibited a ubiquitous but differing expression in human tissues, and the expression pattern differed from that of chondroitin GalNAcT-1. Thus, we demonstrated redundancy in the chondroitin GalNAc transferases involved in the biosynthetic initiation and elongation of chondroitin sulfate, which is important for understanding the biosynthetic mechanisms leading to the selective chain assembly of chondroitin/dermatan sulfate on the linkage region tetrasaccharide common to various proteoglycans containing chondroitin/dermatan sulfate and heparin/heparan sulfate chains.

Molecular cloning and expression of human chondroitin N-acetylgalactosaminyltransferase: the key enzyme for chain initiation and elongation of chondroitin/dermatan sulfate on the protein linkage region tetrasaccharide shared by heparin/heparan sulfate

Based on sequence homology with the recently cloned human chondroitin synthase, we identified a novel beta1,4-N-acetylgalactosaminyltransferase, which consisted of 532 amino acids with a type II transmembrane protein topology. The amino acid sequence displayed 27% identity to that of human chondroitin synthase. The expression of a soluble form of the protein in COS-1 cells produced an active enzyme, which transferred beta1,4-N-acetylgalactosamine (GalNAc) from UDP-[(3)H]GalNAc not only to a polymer chondroitin representing growing chondroitin chains (beta-GalNAc transferase II activity) but also to GlcUAbeta1--3Galbeta1-O-C(2)H(4)NH-benzyloxycarbonyl, a synthetic substrate for beta-GalNAc transferase I that transfers the first GalNAc to the core tetrasaccharide in the protein linkage region of chondroitin sulfate. Hence, the enzyme is involved in the biosynthetic initiation and elongation of chondroitin sulfate and is the key enzyme responsible for the selective chain assembly of chondroitin/dermatan sulfate on the linkage region tetrasaccharide common to various proteoglycans containing chondroitin/dermatan sulfate or heparin/heparan sulfate chains. The coding region of this enzyme was divided into seven discrete exons and localized to chromosome 8. Northern blot analysis revealed that the chondroitin GalNAc transferase gene exhibited a ubiquitous but markedly differential expression in human tissues and that the expression pattern was similar to that of chondroitin synthase. Thus, more than two distinct enzymes forming the novel gene family are required for chain initiation and elongation in chondroitin/dermatan sulfate as in the biosynthesis of heparin/heparan sulfate.

Molecular cloning and expression of a human chondroitin synthase

We have identified a human chondroitin synthase from the HUGE (human unidentified gene-encoded large proteins) protein data base by screening with two keywords: "one transmembrane domain" and "galactosyltransferase family." The identified protein consists of 802 amino acids with a type II transmembrane protein topology. The protein showed weak homology to the beta1,3-galactosyltransferase family on the amino-terminal side and to the beta1,4-galactosyltransferase family on the carboxyl-terminal side. The expression of a soluble recombinant form of the protein in COS-1 cells produced an active enzyme, which transferred not only the glucuronic acid (GlcUA) from UDP-[(14)C]GlcUA but also N-acetylgalactosamine (GalNAc) from UDP-[(3)H]GalNAc to the polymer chondroitin. Identification of the reaction products demonstrated that the enzyme was chondroitin synthase, with both beta1,3-GlcUA transferase and beta1,4-GalNAc transferase activities. The coding region of the chondroitin synthase was divided into three discrete exons and localized to chromosome 15. Northern blot analysis revealed that the chondroitin synthase gene exhibited ubiquitous but markedly differential expression in the human tissues examined. Thus, we demonstrated that analogous to human heparan sulfate polymerases, the single polypeptide chondroitin synthase possesses two glycosyltransferase activities required for chain polymerization.

Subunit C of the vacuolar-type ATPase from the vanadium-rich ascidian Ascidia sydneiensis samea rescued the pH sensitivity of yeast vma5 mutants

A vanadium-accumulating ascidian, Ascidia sydneiensis samea, expresses vacuolar-type H(+)-ATPases (V-ATPases) on the vacuole membrane of the vanadium-containing blood cells known as vanadocytes. Previously, we showed that the contents of their vacuoles are extremely acidic and that a V-ATPase-specific inhibitor, bafilomycin A(1), neutralized the contents of the vacuoles. To understand the function of V-ATPase in vanadocytes, we isolated complementary DNA encoding subunit C of V-ATPase from vanadocytes because this subunit has been known to be responsible for the assembly of V-ATPases and to regulate the ATPase activity of V-ATPases. The cloned cDNA was 1443 nucleotides in length, and encoded a putative 384 amino acid protein. By expressing the ascidian cDNA for subunit C under the control of a galactose-inducible promoter, the pH-sensitive phenotype of the corresponding vma5 mutant of a budding yeast was rescued. This result showed that the ascidian cDNA for subunit C functioned in yeast cells.

[Changes in otoacoustic emission during the glycerol test in the ears of patients with Meniere's disease]

Monitoring of cochlear function is one proposed clinical application of otoacoustic emission (OAE). To determine the clinical utility of OAE in monitoring, we studied changes in OAE during the glycerol test used to diagnose endolymphatic hydrops. Transiently evoked OAE (TEOAE) and distortion product OAE (DPOAE) were measured before and 3 hours after oral administration of glycerol in 22 ears of patients with Meniere's disease. The positive result in the glycerol test was observed in 11 of 22 ears. TEOAE was recorded using a nonlinear click stimulus, and total echo power (TEP) of the whole response and filtered echo power (FEP) of its mid-frequency (1000-2000 Hz) component were used as TEOAE parameters. The growth functions of DPOAE were recorded at 3 F2 frequencies--1000, 1500, and 2000 Hz. Changes in the growth function were determined based on changes in 2 parameters--maximum level and detection threshold of DPOAE. When changes in these 4 parameters exceeded 2 standard deviations above mean test-retest variability determined from OAE data for 17 normal ears, they were considered significant. Significant changes indicating improved cochlear function in 4 OAE parameters or the appearance of OAE during the glycerol test were judged positive for OAE. Regardless of glycerol test results, positive findings were observed in both OAEs whenever a pure-tone threshold at 1000 or 2000 Hz improved. However, even in ears for which pure-tone thresholds at these frequencies did not improve, both OAEs frequently exhibited positive findings. In all ears with a positive result in the glycerol test, positive findings were observed in DPOAE, but not in TEOAE. Of the 2 parameters of TEOAE, FEP always exhibited a positive finding in ears with a positive TEP finding and FEP positivity was higher than that of TEP. In DPOAE, no cases showed a positive finding only at F2 = 2000 Hz, and DPOAE at F2 = 1000 Hz could not be detected in 4 ears due to high noise floor. Overall, positive findings were obtained in 14 ears (63.9%) for TEOAE and 20 ears (90.9%) for DPOAE. In only 1 ear were no positive findings observed in either OAE. The sensitivity of OAE measurement as a diagnostic test for endolymphatic hydrops was higher than that of pure-tone audiometry. Of the 2 OAEs, test sensitivity was much higher for DPOAE than for TEOAE. These results show that OAE measurement detects changes in cochlear function during the glycerol test more sensitively than pure-tone audiometry. They also suggest that FEP is a better indicator than TEP as a parameter of TEOAE, and that DPOAE measurement at F2 = 1000 and 1500 Hz is sufficient for practical clinical use. However, of the 2 OAEs, DPOAE was considered more appropriate than TEOAE for monitoring during the glycerol test because of its high sensitivity in detection of changes in cochlear function. In conclusion, clinical use of OAE, especially DPOAE, as a test complementary to pure-tone audiometry during the glycerol test is very useful and will improve the diagnosis of endolymphatic hydrops.

Pleural-changes in the lung allograft during acute rejection

To ascertain the cause of pleural fibrosis in lung allografts, pleural changes were investigated in rat syngeneic and allogeneic lung grafts. The pleura of lung syngeneic grafts showed no pathological changes except for mild edema on the first day after transplantation. In lung allografts, recipient cells migrated into the subpleural tissue early after transplantation (latent phase). In the vascuar phase, recipient lymphocytes in the subpleural tissue increased in number, while almost all alveolar structures were free from infiltration. Both CD4-positive and CD8-positive cells infiltrated in almost equal numbers with macrophages. The subsets of infiltrating cells were similar to those of the perivascular and peribronchial areas. In the late vascular or alveolar phase, fibroblasts were observed among the infiltrating cells, and fibrotic changes started. In the destructive phase, collagen formation with marked pleural thickening was dominant. Pulmonary acute rejection should be treated at least up to the late vascular phase to prevent pleural fibrosis.

Exclusive expression of transketolase in the vanadocytes of the vanadium-rich ascidian, Ascidia sydneiensis samea

Ascidians, especially those belonging to the Ascidiidae, are known to accumulate extremely high levels of vanadium in vanadocytes, one type of blood (coelomic) cell. Vanadium, which exists in the +5 oxidation state in seawater, is accumulated in the vanadocytes and reduced to the +3 oxidation state. We have been trying to characterize all of the polypeptides specific to vanadocytes and to specify the proteins that participate in the accumulation and reduction of vanadium. To date, we have localized three enzymes in vanadocytes: 6-phosphogluconate dehydrogenase (6-PGDH: EC 1.1.1.44), glucose-6-phosphate dehydrogenase (G6PDH: EC 1.1.1.49), and glycogen phosphorylase (GP: EC 2.4.1.1), all of which are involved in the pentose phosphate pathway. In the current study, we cloned a cDNA for transketolase, an essential and rate-limiting enzyme in the non-oxidative part of the pentose phosphate pathway, from vanadocytes. The cDNA encoded a protein of 624 amino acids, which showed 61.8% identity to the human adult-type transketolase gene product. By immunocytochemistry and immunoblot analyses, the transketolase was revealed to be a protein that was expressed only in vanadocytes and not in any of the more than ten other types of blood cell. This finding, taken together with the localized expression of the other three enzymes, strongly supports the hypothesis that the pentose phosphate pathway functions exclusively in vanadocytes.

Mediastinal esophageal cyst causing unilateral hyperlucent lung

Unilateral emphysema secondary to bronchial obstruction by a foregut-derived mediastinal cyst is rare. Here we describe an infant with a unilateral hyperlucent lung due to compression on the left main bronchus by an esophageal cyst, visualized by chest computed tomography and magnetic resonance imaging. A chest roentgenogram and a perfusion scan presented the normalized left lung after resection of the cyst.

Two cases of repeatedly recurrent atypical thymoma

Two cases of repeatedly recurrent thymoma with myasthenia gravis are detailed here. A 41-year-old woman had 5 recurrent thymomas, including local recurrences and lumbar and lung metastases; she was alive at the time of this writing, which was 22 years after her first surgery. A 36-year-old man had 3 recurrent thymomas, including local recurrence, dissemination, and lung metastasis; he was alive at the time of this writing, which was 16 years after his first surgery. Both recurrent lesions were diagnosed as "atypical thymoma" with moderate nuclear atypia. The patients with atypical thymoma must be followed up carefully due to a possible recurrence. Surgical treatment with chemoradiotherapy can lengthen their survival.

High frequency expressions of CD44 standard and variant forms in non-small cell lung cancers, but not in small cell lung cancers

BACKGROUND AND OBJECTIVES

Organ specificity has been demonstrated in the mode of CD44 expression among several cancers.

METHODS

We examined the expressions of CD44 standard (CD44s) and CD44 variants (CD44v) in 14 cell lines (small cell lung cancer (SCLC): 5, non-small cell lung cancer (NSCLC): 9 and 20 surgically resected samples (SCLC: 7, NSCLC: 13) of lung cancer using reverse transcription polymerase chain reaction and immunohistochemistry.

RESULTS

Although both NSCLC and SCLC expressed CD44s, the frequency and intensity of CD44s expression in NSCLC were different from those in SCLC: cell lines, 89% vs. 40%; tumor samples, 100% (diffusely stained) vs. 57% (focally stained). CD44s expression was partially or completely repressed in SCLC. However, NSCLC frequently expressed CD44v, but SCLC expressed infrequently: cell lines, 67% vs. 20%; tumor samples, 69% vs. 0%. The N-417 line, which only expressed some CD44v in SCLC, falls SCLC and NSCLC both in biomarkers and in growth patterns.

CONCLUSIONS

CD44 expression was repressed in SCLC but was enhanced in NSCLC.

6-Phosphogluconate dehydrogenase is a 45-kDa antigen recognized by S4D5, a monoclonal antibody specific to vanadocytes in the vanadium-rich ascidian Ascidia sydneiensis samea

We previously prepared a monoclonal antibody, S4D5, specific to vanadocytes, vanadium-containing blood cells, in the vanadium-rich ascidian Ascidia sydneiensis samea. Here, we demonstrate that a 45-kDa antigen recognized by S4D5 is 6-phosphogluconate dehydrogenase (6-PGDH), an enzyme of the pentose phosphate pathway, based on cDNA isolation of RNA samples from blood cells of the ascidian. Western blot analysis confirmed an abundance of 6-PGDH protein in the vanadocytes and localization of 6-PGDH in the soluble extract of the blood cells. Soluble protein exhibited a correspondingly high level of 6-PGDH enzymatic activity. Ascidians are known to selectively accumulate high levels of vanadium in vanadocytes, and the highest recorded concentration of accumulated vanadium is 350 mM, which is 10(7) times the concentration in sea water. Almost all vanadium ions are reduced to the +3 oxidation state via the +4 oxidation state in vanadocytes, indicating that reducing agents must participate in the accumulation. On the other hand, vanadium ions in the +5 oxidation state are reduced to the +4 oxidation state by the presence of NADPH in vitro. Together, these observations suggest that NADPH produced in the pentose phosphate pathway may conjugate the reduction of vanadium from the +5 oxidation state through the +4 oxidation state in vanadocytes of ascidians.

Value of mass screening for thyroid cancer

This study aims to clarify the presently uncertain value of mass screening for thyroid cancer, which has been performed by physical examination along with mass screening for breast cancer in Zentsuji, Japan since 1983. Among 18,619 subjects, 36 individuals with thyroid cancer (0.19%) were found. The detection rate was 0.40% at the initial screening and 0.10% during subsequent periodic screening. All thyroid cancers were confirmed histologically as well differentiated carcinoma. The tumor size in the mass-screening group (14 +/- 6 mm) was significantly smaller than in patients presenting at an outpatient clinic during the same period (19 +/- 13 mm) (p < 0.05). The incidence of nodal metastases in the mass-screening group (38%) was significantly lower than in the outpatient group (68%) (p < 0.05). Thus mass screening seemed to find thyroid cancers in a relatively early stage. Mass screening for thyroid cancer was economic in this instance because it was performed together with screening for other cancers, such as breast cancer. Thyroid cancer screening required less than one additional minute per subject. The ultimate aim of mass screening is to reduce mortality. No improvement in prognosis from enforced mass screening for thyroid cancer was detected in this study. It cannot be demonstrated that there is sufficient value of mass screening for thyroid cancer to perform it independently despite early cancer detection.

Mutations of the p53 gene in human lung cancer from chromate-exposed workers

We examined p53 mutations in 20 cancer samples from 19 chromate workers with lung cancer by Polymerase chain reaction-Single strand conformation polymorphism analysis and direct sequencing. Six missense mutations were identified in 4 (20%) of the 20 chromate lung cancer samples. Fewer mutations were found in the patients with lung cancers who had been exposed to chromate than in those who had not. However, the pattern of p53 mutations in lung cancer patients exposed to chromate differed from that of common lung cancers in 3 respects. There were no apparent G to T transversions, which are common base changes in lung cancers. Half of the mutational sites (3/ 6) had changes of AT base-pairs, and 2 of 4 mutational tumor samples had double missense mutations. Our results suggested that chromate exposure may induce point mutation of the p53 gene.

The expression of the CD44 variant exon 6 is associated with lymph node metastasis in non-small cell lung cancer

Recently, it was suggested that splice variants of the surface glycoprotein CD44 (CD44v) were associated with tumor metastasis in some cancers. We examined the expression of variant forms of CD44 in 31 non-small cell lung carcinomas (NSCLCs) and in 8 normal lung tissue samples by reverse transcription-PCR (RT-PCR). CD44v3, CD44v5, CD44v6, and CD44v7 were not expressed or were weakly expressed in normal lung tissue (0 of 8). In contrast, CD44v3, CD44v5, CD44v6, or CD44v7 was expressed in 28 of 31 (90.3%) NSCLCs. Additionally, we examined the expression of CD44v6, which has been shown to be related to metastasis, in 5 normal lungs and 30 NSCLCs by RT-PCR and immunohistochemical analysis to clarify which cells express CD44v6 in NSCLC specimens. Thirty-six of 61 (59%) NSCLCs variably expressed CD44v6 by RT-PCR, and cancer cells were selectively immunostained by anti-CD44v6 antibodies in 23 of 30 (76.7%) NSCLCs. The results of immunohistochemical analysis almost correlated with those of RT-PCR. NSCLCs with lymph node metastasis expressed significantly more v6 exon than did those without lymph node metastasis [23 of 29 (79.3%) versus 13 of 32 (40.6%); P < 0.01]. There was a significant association between the intensity of v6 expression by RT-PCR and the frequency of cases showing lymph node metastasis (Cochran-Armitage's test, P < 0.002). In conclusion, this study demonstrated that in NSCLC, a number of variant forms of CD44 are frequently expressed, although these variants are infrequently expressed in normal lung tissue, and that the expression of CD44v6 is particularly associated with lymph node metastasis in NSCLC.

Pleuropulmonary blastoma: fluorescence in situ hybridization analysis indicating trisomy 2

We report a case of pleuropulmonary blastoma occurring in the right upper lobe and pleura of a 29-month-old boy. Histologically, the tumor was composed of undifferentiated mesenchymal cells with occasional rhabdomyoblastic and chondroid differentiation. Immunohistochemical analysis showed vimentin immunoreactivity in most of the tumor cells, myoglobin, desmin, and actin in the rhabdoid cells, and S-100 protein in the chondroid cells. Fluorescence in situ hybridization (FISH) analysis showed trisomy 2 and normal chromosomal copy numbers for chromosomes 7, 12, 17, 18, and X in the majority of the tumor cell nuclei. The identification of trisomy 2 in the current pleuropulmonary blastoma confirms a previous cytogenetic finding of chromosome 2 abnormality with cultured metaphase cells of a similar case, indicating that the acquisition of an additional chromosome 2 copy in pleuropulmonary blastoma is a nonrandom chromosomal alteration and that pleuropulmonary blastoma is cytogenetically distinct from pulmonary blastoma in which chromosome 2 is bisomic. It is also suggested that pleuropulmonary blastoma may have an intimate tumorigenetic relationship with embryonal rhabdomyosarcoma.

Finding of the same antigens in the polychaete, Pseudopotamilla occelata, as those in the vanadium-rich ascidian, Ascidia sydneiensis samea

The polychaete Pseudopotamilla occelata is the first animal revealed to contain high levels of vanadium besides ascidians. The present experiment disclosed that P. occelata has the same antigens with those in the ascidian Ascidia syndneiensis samea, which were recognized by two types of antibodies, a polyclonal antibody against vanadium-associated proteins extracted from blood cells and a monoclonal antibody against vanadocytes in the vanadium-rich ascidian A. sydneiensis samea. There is, therefore, a possibility that similar mechanism works on the accumulation of vanadium between the Polychaeta and the Ascididae.

Identification of a vanadium-associated protein from the vanadium-rich ascidian, Ascidia sydneiensis samea

Ascidians are known to accumulate vanadium in their blood cells (vanadocytes) at extremely high levels which correspond to about 10(6) to 10(7) times the levels of vanadium ions in seawater. The route for the accumulation of vanadium ions from the outside environment into the blood system in ascidians has not yet been discovered. In the present experiments, using a combined technique of anion exchange column and atomic absorption spectrometry, we first extracted a vanadium-associated protein (VAP) from the blood cells of the ascidian Ascidia sydneiensis samea. VAP was estimated to associate with vanadium at an approximate ratio of 1 mol:16 mole. SDS-PAGE and a polyclonal antibody against VAP (anti-VAP) revealed that VAP is composed of at least two types of peptides estimated to be 12.5 kDa and 15 kDa with a minor peptide of 18 kDa and that VAP is localized in the cytoplasm of the vanadocytes.

Invasive thymoma with endobronchial polypoid growth

A rare case of invasive thymoma with endobronchial polypoid growth is presented. A 68-year-old woman presented with coughing and sputum. The chest X-ray and computed tomography (CT) findings demonstrated a large mass with a calcified lesion in the left hilar region. A bronchoscopic examination showed a polypoid tumor in the left B3b bronchus. The tumor was surgically resected and revealed a unique polypoid endobronchial extension. This tumor was pathologically diagnosed to be invasive thymoma.

High frequency of p53 protein expression in thymic carcinoma but not in thymoma

Thymic epithelial tumours are broadly classified into thymomas and thymic carcinomas. Although both tumours occasionally show invasive growth, they exhibit different clinical and biological findings. The oncogene and anti-oncogene in thymic epithelial tumours have not been evaluated fully. We investigated the expression of p53 protein by immunohistochemical analysis using the anti-p53 polyclonal antibody (CM-1) in 17 thymomas and 19 thymic carcinomas. We also examined p53 gene (exon 5-8) mutation in 18 thymic carcinomas by using polymerase chain reaction-single-strand conformation polymorphism methods and direct sequencing. Of the thymoma cases, only one invasive thymoma showed focal nuclear staining. Fourteen of the 19 thymic carcinomas (74%) showed nuclear staining. Point mutations of the p53 gene were recognized in only 2 of the 18 thymic carcinomas (11%). One was the mutation C to T transition in the first letter of codon 222 in exon 6, which results in the amino acid substitution from proline to serine. Another was a silent mutation. p53 protein accumulation is highly frequent in thymic carcinomas but not in thymomas, and gene mutation is uncommon in thymic carcinomas.

Relationship between prognostic score and thyrotropin receptor (TSH-R) in papillary thyroid carcinoma: immunohistochemical detection of TSH-R

We have demonstrated the expression of thyrotropin receptor (TSH-R) in thyroid neoplasms (13 adenomas, 21 papillary carcinomas, two follicular carcinomas) and adjacent normal thyroid using the monoclonal antibody against human TSH-R and have also demonstrated a relationship between prognostic scores and the expression of TSH-R. Among the adenomas, eight showed an intensity similar to that of normal thyroid and five showed a higher intensity than normal. Two tumours exhibited heterogeneous distribution of TSH-R. Among the papillary carcinomas, seven showed similar intensity to normal tissue and four showed higher intensity and ten showed weaker intensity. Eight tumours showed heterogeneous distribution of the stain. Among the follicular carcinomas, one showed similar intensity to normal tissue and the other exhibited weaker intensity. Both cases showed homogeneous distribution of TSH-R. The adenomas never showed a weaker intensity than normal thyroid, but various intensities of TSH-R occurred in differentiated carcinomas. There was no significant relationship between the clinical data and the signal intensity in the adenomas. Among the papillary carcinomas, however, the group with weaker intensity had significantly poorer prognostic scores than the other two groups. Thus, we assume that low TSH-R may be expressed by the clinically high-risk group of patients with papillary thyroid carcinoma.

Myasthenia gravis induces the activation and maturation of lymphocytes in thymoma

The biological differences between lymphocytes separated from thymoma patients with myasthenia gravis (MG) and those separated from thymoma patients without MG was examined. We investigated whether lymphocytes in thymoma (Th-L) of patients with and without MG could react to interleukin-2 (IL-2) to develop cytolytic activity against K562 and lympho kine-activated killer (LAK) activity, and their phenotypic changes during incubation with IL-2. Sixteen thymoma patients who consisted of eight patients with MG and eight patients without MG were investigated. Th-L of all MG patients could react to IL-2 to develop LAK activity. Th-L of all of MG patients also developed cytolytic activity against K562 target cells. Cytolytic activity against K562 and LAK activity from Th-L of the MG patients were significantly higher than those from Th-L of the patients without MG (P < 0.01, P < 0.01). The proportions of CD3+ and CD4-/CD8+ cells of Th-L of MG patients increased significantly during the incubation period with IL-2 (P < 0.05, P < 0.05). The proportion of CD4+/CD8+ cells of Th-L of patients with MG decreased significantly (P < 0.05) during incubation with IL-2. On the other hand, there was no significant phenotypic change in Th-L of the patients without MG. These results indicate that MG induces the functional and phenotypic activation and functional and phenotypic maturation of Th-L.

Difference in cytokine production in acute and chronic rejection of rat lung allografts

In Brown Norway to Lewis rat lung transplantation, short-term administration of cyclosporine produces permanent adoption of allografts; however, the adopted grafts show symptoms of chronic rejection. To clarify the difference in cytokine production in acute an chronic rejection of the allografts, an immunohistochemical study was performed. In acute rejection, positive cells for respective cytokines were observed in infiltrating cells, increasing in number as the days after transplantation passed, and reaching a maximum on the fifth day. The strongest reactivity was observed perivenously. In chronic rejection, TNF-alpha positive cells were observed in the perivascular and peribronchial regions, especially around class II positive epithelia. The number of positive cells was, however, less than that in the vascular phase of acute rejection. Few cells were positive for IL-1 beta, IFN-gamma and, unexpectedly, for IL-4. These facts indicate the functional difference of infiltrating cells between acute and chronic rejection.

A dose-response relationship between the frequency of p53 mutations and tobacco consumption in lung cancer patients

Mutations of the p53 tumor suppressor gene are frequent in lung cancers. It is suggested that p53 mutations are associated with smoking-induced lung carcinogenesis. We examined p53 mutations in 53 lung cancers by analyzing reverse transcription-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) to ascertain the association between p53 mutations and smoking. Twenty-five (47%) of 53 lung cancers carried p53 mutations. A discriminant analysis showed that the Brinkman index (0.156) and gender (0.140) significantly influenced p53 mutations. Furthermore, there was a dose-response relationship between the quantity of cigarettes consumed and the frequency of p53 mutations in lung cancer patients (P < 0.001). In patients with adenocarcinoma, the frequency of p53 mutations correlated with the amount of the tobacco smoked (P < 0.05). We suggest that the p53 gene is a target of particular carcinogen in tobacco smoke.

Effect of diabetic sera on the conversion of eicosapentaenoic acid (EPA) to prostaglandin I3 by cultured bovine aortic endothelial cells

The effects of sera from diabetic patients and healthy donors on the synthesis of prostaglandin I2 (PGI2) and PGI3 in vitro were studied in confluent bovine aortic endothelial cells cultured with EPA. The products 6-keto-PGF1 alpha and delta 17-6-keto-PGF1 alpha were measured by GC/SIM as markers of PGI2 and PGI3 formation in growth medium after 60 min of incubation. PGI2 and PGI3 synthesis with 10% diabetic sera were less than with sera from healthy donors (p < 0.05). However, the total prostacyclin production (PGI2 and PGI3) in the cell cultures incubated with 10 microM EPA and 10% diabetic sera approximated that of the cultures incubated with the sera of healthy donors without EPA. These results suggest that the diabetic sera inhibits PGI2 and PGI3 synthesis in the cultured endothelial cells, and that EPA intake may reduce the complications of diabetes mellitus, such as microangiopathy and vaso-occlusive diseases, and enhances the production of PGI3 which seems to exert a strong anti-aggregatory effect.

Defective bronchus-associated lymphoid tissue in long-term surviving rat lung allografts

In a previous study we found that a local immune response did not develop in the bronchus-associated lymphoid tissue (BALT) of infected rat allografts. We hypothesized that the BALT in rat lung allografts was damaged after allotransplantation. Therefore, we investigated three prerequisites for a normal function of the BALT, i.e., its structure, the uptake of antigens, and the lymphocyte migration to the BALT in three groups of rats (n = 10 each): (1) Brown Norway(BN)-to-Lewis (LEW) allografts; (2) LEW-to-LEW isografts; and (3) normal LEW rats. All rats were immunosuppressed with CsA (injected on days 2 and 3). Six mo after transplantation the structure of the BALT and the uptake of intrabronchially injected carbon particles in the BALT were determined histologically; the migration of intravenously injected, fluoroscein-isothiocyanate labeled lymphocytes to the BALT was determined immunohistochemically. In the allografts the BALT was defective in all three investigated aspects. It was reduced in size and lymphocyte density and was largely replaced by fibrous tissue. Twenty-four h after administration no carbon particles and only a few labeled lymphocytes were found in the BALT. In contrast, in the syngeneically transplanted and nontransplanted lungs the BALT consisted of a large and dense collection of lymphocytes. In these BALTs large numbers of carbon particles and labeled lymphocytes were found. In conclusion, after allogeneic transplantation the BALT in the lung becomes defective in structure and function. The BALT is most likely damaged by rejection, since the BALT is syngeneic lung transplants was perfectly normal.

Granulocyte-macrophage colony-stimulating factor augments lymphokine-activated killer activity from pleural cavity mononuclear cells of lung cancer patients without malignant effusion

The role of recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) in augmentation of lymphokine-activated killer (LAK) cell induction by interleukin-2 (IL-2) from pleural cavity mononuclear cells (PCMNCs) was examined in sixteen patients with resectable primary lung cancer not associated with malignant effusion. None of the patients had received any anticancer therapy prior to this study. Incubation of PCMNCs of patients without malignant effusion with GM-CSF for 4 days in the presence of IL-2 resulted in a significant increase in LAK activity against natural killer-resistant Daudi cells. This result was obtained by using the 4 h 51Cr-release assay. PCMNCs and blood mononuclear cells (BMNCs) were harvested simultaneously from pleural cavity lavage fluid and peripheral blood in lung cancer patients. The LAK activity developed from PCMNCs and BMNCs following incubation with IL-2 for 4 days, but the LAK activity from PCMNCs was significantly lower than that from BMNCs (P < 0.05). Incubation of PCMNCs with GM-CSF augmented the LAK activity from PCMNCs to a level as high as that from BMNCs. These results suggest that the combined use of GM-CSF with IL-2 may result in augmentation of LAK activity developed from PCMNCs of lung cancer patients without malignant effusion.

Difference in thymidylate synthetase activity in involved nodes compared with primary tumor in breast cancer patients

Thymidylate synthetase (TS) is a key enzyme as a methyl donor in the methylation reaction from dUMP to dTMP. TS activity was assessed in various tissue of mammary disorders. The descending order of TS activity was as follows: cancer-positive nodes, primary cancers, cancer-negative nodes, benign lesions, and normal parenchyma. Significant differences in TS activity were found between the positive nodes and each of the other tissues (p < 0.01). In node-positive cases, a significant correlation in TS activity was found between the primary cancers and positive nodes (r = 0.616, p = 0.033). There was no correlation between the nodal status and the TS activity in primary cancers. In 11 of 12 cases, the TS activity of positive nodes was higher than the 'calculated' TS activity of the primary cancer, which was defined as the TS activity per unit weight of cancer cells. A significant correlation was found between the calculated TS activity and the mitotic frequency in primary cancers (r = 0.697, p = 0.0001). On the other hand, a significant correlation could not be found between the TS activity and the mitotic frequency in positive nodes (r = 0.364, p = 0.244).

Pathogenesis of late airway changes in long-term surviving lung allografts

Late airway changes are frequently observed in long-term surviving rat lung allografts. In this present study, we investigate this problem using the mixed lymphocyte reaction, graft-versus-host assay (popliteal lymph node assay), skin grafting from the donor strain to the lung allograft recipient, and histology to evaluate this problem. The results show that spleen cells from recipient rats with long-term surviving lung allografts possessed alloreactivity in mixed lymphocyte reaction against both donor and third-party ACI antigens. Suppressor cell activity was not detected in spleen cells from these recipient rats. The popliteal lymph node assay showed that the response to recipient spleen cells was detectable but weaker than that of naive spleen cells from the same strain. Mean survival time of skin grafts from the donor strain to long-term allograft survivors was significantly longer than that between donor and recipient strains. Chest roentgenograms revealed opacification of long-term surviving lung allografts at 2 to 3 wk after skin transplantation that was coincident with the rejection of the skin grafts, and histologic examination of the lung allografts revealed changes compatible with acute rejection. We conclude that alloreactivity can be demonstrated in rats with long-term surviving lung allografts and suggest that late airway changes in these lungs are immunologically mediated.

Immunological detection of a vacuolar-type H(+)-ATPase in vanadocytes of the ascidian Ascidia sydneiensis samea

Ascidians belonging to the family Ascidiidae are known to accumulate vanadium from seawater in their blood cells, concentrating vanadium by a factor of 10(7). Among several different types of blood cell, the signet ring cells have both high levels of vanadium and a low pH. These observations suggest the possibility that proton ions concentrated by a H(+)-ATPase are energetically linked to the accumulation of vanadium. In the present experiments, therefore, we made an immunological search for a H(+)-ATPase in the vacuolar membranes of the signet ring cells, as a first step in our attempts to clarify the energetics of the accumulation of vanadium by these cells. Antibodies raised against the 72-kDa and 57-kDa subunits of a vacuolar-type H(+)-ATPase from bovine chromaffin granules reacted with the vacuolar membranes of signet ring cells. Immunoblotting analysis confirmed that specific antigens in ascidian blood cells actually reacted with the antibodies. Furthermore, addition of bafilomycin A1, a specific inhibitor of vacuolar-type H(+)-ATPase, inhibited the uptake of protons by the vacuoles of signet ring cells. Thus, the addition of bafilomycin A1 inhibited the pumping function of the vacuoles of signet ring cells, with resultant neutralization of the contents of the vacuoles.

Application of electrical impedance analysis for diagnosis of a pulmonary mass

The electrical impedance of a pulmonary mass was measured in 53 patients of whom 44 had primary lung cancer, 5 had metastatic lung tumor, and 4 had organizing pneumonia. Because biologic tissue can be regarded, electrically, to consist of extracellular resistance (Re), intracellular resistance (Ri), and the electrical capacitance of the cell membrane (Cm), these three parameters were calculated from the measured electrical impedance of tissue by a curve-fitting technique using a computer program. The Re of lung tissue was significantly greater (p < 0.01) and the Cm of lung tissue was significantly less (p < 0.01) than that of a pulmonary mass. The Re of malignant tumors (both lung cancer and metastatic tumors) was significantly greater (p < 0.01) and the Cm of malignant tumors was significantly less (p < 0.01) than that of organizing pneumonia. With this information, we used a biopsy needle to diagnose nine intrathoracic lesions. This technique additionally allowed us to confirm the proximity of the needle tip of the mass. The electrical impedance of the lung mass was measured through the biopsy needle using a modified impedance analysis system before the biopsy was performed. There were no false-negative results, and one false-positive result. The rapid measurement of the electrical impedance of a pulmonary mass, preoperatively, may be of value in the clinical evaluation of a pulmonary mass both by facilitating needle guidance and by permitting diagnosis based on electrical impedance.

[Two cases of thyroid cancer resected with trachea]

We described two patients of thyroid cancer with tracheal invasion. A 54-aged female visited our hospital with complaint of the neck pain. Echography showed a tumor in the right lobe of the thyroid. In operation the thyroid tumor invaded the trachea and right recurrent nerve. A 24-aged male visited our hospital with complaint of a mass of the left side neck. Echography showed a tumor in the left lobe of the thyroid. In operation the thyroid tumor invaded the trachea, lymph node and left recurrent nerve. In these two cases we could find thyroid tumors invaded into the trachea by echography. We re-evaluated the utility of echography.

Thyroid nodules in female uremic patients on maintenance hemodialysis

We investigated the incidence of thyroid nodules in female uremic patients on maintenance hemodialysis using a high-frequency sonographic scanner. In 47 (21.0%) of the 224 female normal controls and 33 (55.0%) of the 60 female patients, thyroid nodules were detected. The difference in these incidences between controls and patients was significant. There were no differences in age, duration of hemodialysis, the level of blood urea nitrogen, parathyroid hormone or thyroid stimulating hormone between the patients with thyroid nodules and those without nodules. Although there is a correlation between uremia and the development of thyroid nodules, the details of the underlying mechanism of their association remain unclear.

Tumor progression accompanied by increase in proliferation rate in breast cancer: a preliminary report

Forty consecutive cases with invasive ductal carcinoma of the breast (samples of both the primary invasive area and the involved node were available for 19 cases, multiple sections of breast tissue including both the primary invasive area and forefront intraductal cancerous area were available for 15 cases; and multiple sections of breast cancerous tissue and the involved node were available for six cases) were examined by immunohistochemical analysis for evaluation of their proliferation rate. In this study, we selected the PCNA index as a marker of the proliferation rate of the tumor cells. We demonstrated that the PCNA index of the primary invasive area was significantly higher than that of the forefront intraductal area (P = 0.0017), and the PCNA index of the involved nodes was significantly higher than that of the primary invasive area (P = 0.0004). These preliminary findings suggest that the progression from the tumor cells of the intraductal cancerous area to the metastatic tumor cells must be accompanied by two phases of increase in the proliferation rate.