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The major purpose of field workshops on volcanic gases, organized by the IAVCEI Commission on the Chemistry of Volcanic Gases, is the collection and analysis of volcanic gas discharges with the aim to develop and improve techniques for the geochemical surveillance of active volcanoes. The fourth and fifth workshops were held at Vulcano island, Italy, in 1991 and on Java island, Indonesia, in 1994, respectively. Gas samples were collected from four gas vents by nine groups at Vulcano and from eight gas vents by eight groups on Java. The quality (e.g. scatter of the data) of most of the results, reported from these two workshops, is sufficient to permit a broad chemical classification of the discharge and meaningful thermodynamic interpretation. In most cases, the majority of the data for individual gas vents cluster closely around the median values, suggesting that the median values are the best estimates of chemical composition. There is, however, also a considerable scatter of the analytical data, and this scatter warns us to not rely too heavily on a single analytical value, in particular on a value for CH4and CO, because analytical data for these species often show a wide scatter. This warning is particularly relevant for chemical monitoring of volcanic activity. Further improvement of the sampling and analytical techniques as well as more detailed comparison of the techniques is required to reduce such uncertainty in order to interpret the volcanic activity and hydrothermal conditions.

The D/H and 18O/16O ratios of water in the active crater lake situated on the Kusatsu-Shirane volcano, Japan are about 20 and 6‰, respectively, higher than local meteoric water. The ratios show seasonal variations superimposed on a gradual change over nine years. The isotopic ratios started to increase in early 1990 and decrease in the spring of 1995. The seasonal variation which is high in winter and low in summer correlates with the temperature difference between lake water and ambient air. The large temperature difference in winter enhances the evaporation of lake water and produces the enriched isotopic ratios relative to the ratios in summer. The accumulation of snow and the decrease in the flux of meteoric water into the lake strengthens the winter-time isotopic enrichment. The enriched isotopic ratios of the lake water over a long time result from the addition of an end member with heavy isotopic ratios contained in a thermal fluid supplied to the lake. Considering the water balance in the lake, the isotopic ratios of the thermal fluid were found to be close to the lake water itself, suggesting the circulation of the lake water seeping through lake floor. Based on the correlation between Cl−concentration and the isotopic ratios, the contribution by the heavy end member was estimated to be 25–36% relative to the enrichment by evaporation. The heavy end member could be a liquid phase evolved from a parental fluid, which is a mixture of local meteoric water and a magmatic fluid as found in high-temperature volcanic gases.

Galectin-1 (gal-1) a member of the mammalian beta-galactoside-binding proteins recognizes preferentially Galbeta1-4GlcNAc sequences of oligosaccharides associated with several cell surface glycoconjugates. In the present work, gal-1 has been identified to be a ligand for the CD3-complex as well as for CD2 as detected by affinity chromatography of Jurkat T-cell lysates on gal-1 agarose and by binding of the biotinylated lectin to CD3 and CD2 immunoprecipitates on blots. In CD45(+)Jurkat E6.1 cells, the lectin stimulates a sustained increase in the intracytoplasmic calcium concentration ([Ca(2+)](i)) consisting of both the release of calcium from intracellular stores and the calcium influx from the extracellular space. This effect of gal-1 on [Ca(2+)](i)is completely inhibited by lactose at 10 mM and was absent in CD45(-)Jurkat J45.01 cells. Preincubation of Jurkat E6.1 cells with cholera toxin or with the protein tyrosine kinase inhibitor herbimycin A reduced the gal-1 induced calcium response whereas the increase in [Ca(2+)](i)stimulated by CD2 or CD3 monoclonal antibodies (mAbs) was completely inhibited. Depolarization of E6.1 cells in a high-potassium buffer, a standard method to activate voltage-operated calcium channels, was without effect on [Ca(2+)](i). Membrane depolarization with gramicidin or by a high-potassium buffer was without effects on the lectin-mediated calcium release from intracellular stores but inhibited the gal-1 induced receptor-operated calcium influx. In Jurkat E6.1 cells the lectin stimulates the transient generation of inositol-1,4,5-trisphosphate and the tyrosine phosphorylation of phospholipase Cgamma1. The results suggest that the ligation of CD2 and CD3 by gal-1 induces early events in T-cell activation comparable with that elicited by CD2 or CD3 mAbs.

The complete primary structure of chicken 16-kDa beta-galactoside-binding lectin (C-16) was determined. It was composed of 134 amino acid residues and has an acetylated NH2 terminus. A cDNA was also cloned, but no signal sequence was found in the initiator region. The initiator methionine remained as the NH2 terminus of the mature lectin. Although C-16 is distinct from chicken 14-kDa beta-galactoside-binding lectin (C-14), it proved to be a member of the vertebrate 14-kDa-type lectin family. Comparison of the primary structures between the vertebrate 14-kDa-type lectins suggests that C-14 and C-16 were produced by gene duplication of an ancestral lectin gene at a time close to the divergence of birds and mammals. Northern and Southern blot analysis indicated that these isolectins are encoded by individual genes which are differently regulated during the development of the embryo. A recombinant C-16 lectin was produced in Escherichia coli. The product was indistinguishable from the authentic C-16 lectin except that the NH2 terminus of the former was found to begin with free methionine.

Physical, chemical and isotopic parameters were measured in fumaroles at the Vulcano crater and in drowned fumaroles near the beach. The data were used to define boundary conditions for possible conceptual models of the system.Crater fumaroles: time variations of CO2 and SO2 concentrations indicate mixing of saline gas-rich water with local fresh water. Cl/Br ratios of 300– 400 favour sea-water as a major source for Cl, Brand part of the water in the fumaroles. Cl concentrations and dD values revealed, independently, amixing of 0.75 sea-water with 0.25 local freshwaterin furmarole F-5 during September 1982.Patterns of parameter correlation and mass balances reveal that CO2, S, NH3 and B originate from sources other than sea water. The CO2 value of d13C = - 2%o favours, at least partial, origin from decomposition of sedimentary rocks rather than mantle-derived material. Radiogenic4He(1.3 × lO-3 ccSTP/g water) and radiogenic40Ar(10.6 × 10-4 ccSTP/g water) are observed, (4He/40Ar)radiogenic = 1.2, well in the range of values observed in geothermal systems.Drowned fumaroles: strongly bubbling gas at a pond and at the beachappears to have the same origin and initial compositionas the crater fumaroles (2 km away). The fumarolic gas is modified by depletion of the reactive gases, caused by dissolution in shallow-water. Atmospheric Ne, Ar, Kr and Xe are addeden route, some radiogenic He and Ar are maintained. The Vulcano system seems to be strongly influenced by the contribution of sea-water and decomposition of sedimentary rocks. Evidence of magmatic contributions is mainly derived from heat.

Galectins are a family of soluble beta-galactoside-binding lectins distributed in both vertebrates and invertebrates and, more recently, found also in fungus. The 32-kDa galectin isolated from the nematode Caenorhabditis elegans (Hirabayashi, J., Satoh, M., and Kasai, K. (1992) J. Biol. Chem. 267, 15485-15490) was the first "tandem repeat-type" galectin, containing two homologous carbohydrate-binding sites. Here, we report the structure of the nematode 32-kDa galectin gene. Physical mapping by yeast artificial chromosome polytene filter hybridization revealed that the 32-kDa galectin gene is located on chromosome II. Analysis of the transcript (1.4 kilobases) showed the presence at its 5'-end of a 22-nucleotide trans-spliced leader sequence (SL1). The entire genomic structure spanning >5 kilobase pairs (kbp), including the 5'-noncoding region, two intervening sequences (introns 1 and 2), and the 3'-noncoding region, was completely determined by the combination of genomic polymerase chain reaction and conventional colony hybridization. Intron 1 was relatively long (2.4 kbp) and was found to be inserted after the ninth codon (TAC) from the initiation codon. This position proved to be almost homologous to the conserved first intron insertion position in the vertebrate galectin genes (i. e. genes of mammalian galectin-1, -2, and -3 and chick 14-kDa galectin). On the other hand, intron 2 was much shorter (0.6 kbp), and it was inserted into the central region of the second carbohydrate-binding site. Although such an insertion pattern has never been observed in the vertebrate galectin genes, it seems to be common in C. elegans tandem repeat-type galectin genes, as predicted by the C. elegans genome project (Coulson, A., and the C. elegans Genome Consortium (1996) Biochem. Soc. Trans. 24, 289-291). Based on extensive sequence comparison, the origin and molecular evolution of the tandem repeat-type galectins are discussed.

Novel type lectins were found in the phylum Annelida, i.e. in the earthworm, tubifex, leech, and lugworm. The lectins (29-31 kDa) were extracted from the worms without the use of detergent and purified by affinity chromatography on asialofetuin-agarose. On the basis of the partial primary structures of the earthworm Lumbricus terrestris 29-kDa lectin (EW29), degenerate primers were synthesized for use in the reverse transcriptase-polymerase chain reaction. An amplified 155-base pair fragment was used to screen a cDNA library. Four types of full-length clones were obtained, all of which encoded 260 amino acids, but which were found to differ at 29 nucleotide positions. Since three of them resulted in non-silent substitutions, EW29 mRNA was considered to be a mixture of at least three distinct polynucleotides encoding the following proteins: Ala44-Gln197-Ile213 (clone 5), Gly44-Gln197-Val213 (clone 7), and Ala44-His197-Ile213 (clones 8 and 9; different at the nucleotide level, but encoding an identical polypeptide). Genomic polymerase chain reaction using DNA from a single worm revealed that the single worm already had four sets of cDNAs. The EW29 protein showed two features. First, the lectin was composed of two homologous domains (14,500 Da) showing 27% identity with each other. When each of the domains was separately expressed in Escherichia coli, the C-terminal domain was found to bind to asialofetuin-agarose as strongly as the whole protein, whereas the N-terminal domain did not bind and only retardation was observed. EW29 was found to exist as a monomer under non-denaturing conditions. It had significant hemagglutinating activity, which was inhibited by a wide range of galactose-containing saccharides. Second, EW29 contained multiple short conserved motifs, "Gly-X-X-X-Gln-X-Trp." Similar motifs have been found in many carbohydrate-recognizing proteins from an extensive variety of organisms, e.g. plant lectin ricin B-chain and Clostridium botulinum 33-kDa hemagglutinin. Therefore, these carbohydrate-recognition proteins appear to form a protein superfamily.

In our previous study (Hirabayashi, J., Satoh, M., Ohyama, Y., and Kasai, K. (1992) J. Biochem. (Tokyo) 111, 553-555), two beta-galactoside-binding lectins (apparent subunit molecular masses, 16 and 32 kDa, respectively) were identified in the nematode Caenorhabditis elegans. The subsequent study revealed that the 32-kDa lectin is a member of the galectin family. Since the 32-kDa galectin was found to consist of two homologous domains (approximately 16 kDa), 16-kDa lectin was thought to be a degradation product of the 32-kDa galectin. To clarify this, the 16-kDa lectin was purified by an improved procedure employing extraction with a calcium-supplemented buffer. The purified 16-kDa lectin was found to exist as a dimer (approximately 30 kDa) and showed hemagglutinating activity toward trypsinized rabbit erythrocytes, which was inhibited by lactose. Almost the whole sequence of the 16-kDa polypeptide (approximately 95%, 135 amino acids) was determined after digestion with various proteases. Based on the obtained information, a full-length cDNA was cloned with the aid of RNA-polymerase chain reaction. The clone encoded 146 amino acids including initiator methionine (calculated molecular mass, 15,928 Da). Based on these results, it was concluded that the 16-kDa lectin is a novel member of the galectin family, but not a degradation product of the 32-kDa galectin as had previously thought. However, the 16-kDa galectin showed relatively low sequence similarities to both the N-terminal and the C-terminal domains of the 32-kDa galectin (28% and 27% identities, respectively) and to various vertebrate galectins (14-27%). Nonetheless, all of the critical amino acids involved in carbohydrate binding were conserved. These observations suggest that, in spite of phylogenic distance between nematodes and vertebrates, both the 16-kDa and 32-kDa nematode isolectins have conserved essentially the same function(s) as those of vertebrate galectins, probably through recognition of a key disaccharide moiety, "N-acetyllactosamine."

The 14 kD S-type lectin from human placenta may have a role in regulating the maternal immune response to fetal antigens. In this study, an immunoperoxidase technique was used to determine the distribution of the lectin at the human maternofetal interface. Tissue obtained during the first trimester of pregnancy and at term was used. The lectin was not detectable in either the villous syncytiotrophoblast or the underlying cytotrophoblast in first-trimester tissue, although some cells of the cytotrophoblast columns were reactive. It was also not detectable in villous or extravillous trophoblast populations at term. In contrast, strong reactivity was found in decidual stromal cells throughout gestation, and endometrial stromal cells were also positive. The lectin is, therefore, not a component of the immunosuppressive factors associated with syncytiotrophoblast membranes, but may have a role in either the decidual control of trophoblast migration or some functions unrelated to pregnancy, or both.

Jacalin, a lectin from the jackfruit Artocarpus integrifolia, has been known as a valuable tool for specific capturing of O-glycoproteins such as mucins and IgA1. Though its sugar-binding preference for T/Tn-antigens is well established, its detailed specificity has not been elucidated. In this study, we prepared a series of mucin-type glycopeptides using human glycosyltransferases, that is, ST6GalNAc1, Core1Gal-T1 and -T2, β3Gn-T6, and Core2GnT1, and investigated their binding to immobilized Jacalin by frontal affinity chromatography (FAC). As a result, consistent with the previous observation, Jacalin showed high affinity for T-antigen (Core1) and Tn-antigen (alpha N-acetylgalactosamine)-attached peptides. Furthermore, we here show as novel findings that (1) Jacalin also showed significant affinity for Core3 and sialyl-T (ST)-attached peptides, but (2) Jacalin could not bind to Core2, Core6, and sialyl-Tn (STn)-attached peptides. The results were also confirmed by FAC using p-nitrophenyl (pNP)-derivatized saccharides. In conclusion, Jacalin binds to a GalNAcα1-peptide, in which C6-OH of αGalNAc is free (i.e., Core1, Tn, Core3, and ST), whereas it cannot recognize a GalNAcα1-peptide with a substitution at the C6 position (i.e., Core2, Core6, and STn). These findings provide useful information when applying jacalin for functional analysis of mucin-type glycoproteins and glycopeptides.