Fraction A of armadillo submandibular glycoprotein and its desialylated product as sialyl-Tn and Tn receptors for lectins

Fraction A of the armadillo submandibular glycoprotein (ASG-A) is one of the simplest glycoproteins among mammalian salivary mucins. The carbohydrate side chains of this mucous glycoprotein have one-third of the NeuAc alpha 2-->6GalNAc (sialyl-Tn) sequence and two thirds of Tn (GalNAc alpha-->Ser/Thr) residues. Those of the desialylated product (ASG-Tn) are almost exclusively unsubstituted GalNAc residues (Tn determinant). When the binding properties of these glycoproteins were tested by a precipitin assay with Gal, GalNAc and GlcNAc specific lectins, it was found that ASG-Tn reacted strongly with all of the Tn-active lectins and completely precipitated Vicia villosa (VVL both B4 and mixture of A and B), Maclura pomifera (MPA), and Artocarpus integrifolia (jacalin) lectins. However, it precipitated poorly or negligibly with Ricinus communis (RCA1); Dolichos biflorus (DBA); Viscum album, ML-I; Arachis hypogaea (PNA), and Triticum vulgaris (WGA). The reactivity of ASG-A (sialyl-Tn) was as active as that of ASG-Tn with MPA and less or slightly less active than that of ASG-Tn with VVL-A+B, VVL-B4, HPA, WFA, and jacalin, as one-third of its Tn was sialylated. These findings indicate that ASG-A and its desialylated product (ASG-Tn) are highly useful reagents for the differentiation of Tn, T (Gal beta 1-->3GalNAc), A (GalNAc alpha 1-->3Gal) or Gal specific lectins and monoclonal antibodies against such epitopes.

A sheep hydatid cyst glycoprotein as receptors for three toxic lectins, as well as Abrus precatorius and Ricinus communis agglutinins

The binding properties of a glycoprotein with blood group P1 specificity isolated from sheep hydatid cyst fluid with Gal and GalNAc specific lectins was investigated by quantitative precipitin and precipitin inhibition assays. The glycoprotein completely precipitated Ricinus communis agglutinin (RCA1), Abrus precatorius agglutinin (APA) and Mistletoe toxic lectin-I (ML-I). Only 1.0 microgram of P1 glycoprotein was required to precipitate 50% of 5.1 micrograms ML-I nitrogen. It also reacted well with abrin-a and ricin, precipitating over 73% of the lectin nitrogen added, but poorly or weakly with Dolichos biflorus (DBL), Vicia villosa (VVL, a mixture of A4, A2B2 and B4), VVL-B4, Arachis hypogaea (PNA), Maclura pomifera (MPL), Bauchinia purpurea alba (BPL) and Wistaria floribunda (WFL) lectins. When an inhibition assay in the range of 5.1 micrograms N to 5.9 micrograms N of lectins (ML-I, abrin-a; ricin, RCA1, and APA, and 10 micrograms P1 active glycoprotein interaction was performed; from 76 to 100% of the precipitations were inhibited by 0.44 and 0.52 mumol of Gal alpha 1-->4Gal and Gal beta 1-->4GlcNAc, respectively, but not or insignificantly with 1.72 mumol of GlcNAc. The Gal alpha 1-->4Gal disaccharide found in this P1 active glycoprotein is a frequently occurring sequence of many glycosphingolipids located at the surface of mammalian cell membranes, especially human erythrocytes and intestinal cells for ligand binding and microbial toxin attachment. The present finding suggests that the Gal alpha 1-->4Gal beta 1-->4GlcNAc sequence in this P1 active glycoprotein is one of the best glycoprotein receptors for three toxic lectins (ricin, abrin-a, and ML-I) as well as for APA, and RCA1, and the result of inhibition assay implies that these lectins are recognizing part or all of the Gal alpha 1-->4Gal beta 1-->4GlcNAc sequence in the P1 active glycoprotein.

Multilineal hematopoiesis in a three-dimensional murine long-term bone marrow culture

The highly packed cell density and the three-dimensional structure in the hematopoietic compartment of bone marrow facilitate cell-to-cell and cell-to-matrix interactions known to be important for hematopoietic activities. To provide a similar environment in vitro, we developed a long-term bone marrow culture (LTBMC) system, continuously perfused with Dexter's medium, employing packed, highly porous bovine collagen microspheres as the matrix support for marrow cell growth. Using murine bone marrow as a model, we found that the culture system differed from the conventional flask culture in the following ways: 1) as revealed by the electron microscopy, the bone marrow cells in the culture system grew in a three-dimensional configuration, similar to that in vivo, 2) the cell output from the culture system at 37 degrees C was virtually the same as that at 33 degrees C, and 3) in the absence of exogenous growth factors, except those in the serum, the culture system produced lymphoid cells and all stages of committed cells (i.e., erythrocytes, granulocytes, macrophages, and megakaryocytes), thus indicating multilineal differentiation of the hematopoietic stem cells. Furthermore, cell clusters resembling erythroblastic islands were observed in the absence of exogenous erythropoietin (Epo). The culture system appears to provide a different microenvironment than that of the flask culture and may be used as an alternative model for hematopoiesis.

A fluorescence quench and dequench assay of fibrinogen polymerization, fibrinogenolysis, or fibrinolysis

We present a kinetic assay based on the use of fluorescein isothiocyanate (FITC)-labeled fibrinogen as a fluoroactive substrate. The multiple FITCs bound to fibrinogen experienced quenching due to their close proximity. The thrombin-induced polymerization of FITC-fibrinogen led to additional fluorescence quenching due to enhanced neighbor-neighbor interactions in protofibrils and protofibril aggregates. The initial rate of quenching was directly dependent on the thrombin concentration at either low or high ionic strength. The final extent of quenching during polymerization with thrombin could be modulated by prevailing ionic strength and thrombin concentration suggesting that the quenching was due to fibril extension as well as aggregation. The full extent of quenching was greatly reduced by addition to the reaction of unlabeled fibrinogen or Gly-Pro-Arg-Pro, as expected for quenching due to neighbor-neighbor interactions. In contrast to polymerization, cleavage of fibrinogen by plasmin released FITC-labeled fragments free of proximity-based quenching that resulted in a large intensity increase as lysis proceeded--a process termed dequenching. The majority of the dequenching signal during fibrinogenolysis occurred during the generation of fragment X which proceeded as a first-order process with respect to fibrinogen-bound plasmin with kcat = 0.479 s-1. The Kd of active plasmin to fibrinogen was calculated to be 0.42 microM. Addition of epsilon-aminocaproic acid (epsilon ACA)-plasmin complex to FITC-fibrinogen produced little dequenching, demonstrating a requirement for binding in order to initiate lysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning and expression of the Clostridium thermocellum celS gene in Escherichia coli

Clostridium thermocellum ATCC 27405 produces an extremely complicated multi-component cellulase aggregate (cellulosome) highly active on crystalline cellulose. From the cellulosome, two subunits, CelS (or Ss; M(r) = 82,000) and CelL (or SL, CipA; M(r) = 250,000), have been identified as essential for crystalline cellulose degradation [Wu et al. (1988) Biochemistry 27:1703]. We have determined the DNA sequence of the celS gene from four cloned DNA fragments encompassing this gene [Wang et al. (1993) J Bacteriol 175:1293]. To express the entire celS gene in Escherichia coli, the celS structural gene was amplified by the polymerase chain reaction (PCR) employing the PCR primers corresponding to sequences flanking the desired gene. This PCR product (2.1 x 10(3) bases; 2.1 kb) was cloned into an E. coli expression vector pRSET B. Subsequent expression of the cloned gene resulted in a fusion protein (rCelS; M(r) = 86,000) as inclusion bodies. The rCelS protein was recognized specifically by an anti-CelS antiserum in a Western blot analysis. The inclusion bodies were purified and solubilized in 5 M urea. The refolded rCelS produced very little reducing sugar from carboxymethylcellulose. However, it showed a higher activity on the crystalline cellulose (Avicel) and an even higher activity on phosphoric-acid-swollen Avicel. These results indicate that the CelS is an exoglucanase.

The biotin/avidin-mediated microtiter plate lectin assay with the use of chemically modified glycoprotein ligand

The conditions of a simple and sensitive microtiter plate lectin assay with biotinylated TF- and/or Tn-reactive lectins and ExtrAvidin/alkaline phosphatase conjugate are described. As ligand for lectin binding, chemically modified glycophorin A from human erythrocytes was used. The TF and Tn receptors present in glycophorin A in cryptic form were exposed by desialylation under mild acidic conditions (TF) and by removing galactose residues from asialoglycophorin by Smith degradation (Tn). These modifications can be performed either in solution or on the plate coated with untreated glycophorin. It was demonstrated with six lectins that their biotinylation via lectin amino groups gave products of higher binding activity than biotinylation via periodate-oxidized carbohydrate residues of lectins. The first step in the binding assay requires the selection of the proper concentration of the glycoprotein used for coating the plate, since the lectins tested showed a maximal binding at an optimal glycophorin concentration, and in many cases the binding was distinctly lower when a higher ligand concentration was used for coating. The inhibition of binding of Tn-reactive lectins to plates coated with asialo-agalactoglycophorin (Tn antigen) was performed using low- and high-molecular-weight inhibitors (1-2 micrograms lectin was used for each inhibition curve) and concentrations of inhibitors required for 50% inhibition of lectin binding were compared. The results were in agreement with the known specificity of the lectins tested. In conclusion, the method described is simple, sensitive, and versatile, enabling the characterization of lectin specificity with a broad spectrum of inhibitors using microgram quantities of lectin only.

Transport phenomena and clot dissolving therapy: an experimental investigation of diffusion-controlled and permeation-enhanced fibrinolysis

We have investigated the effects of diffusive and convective transport on fibrinolysis. Using a constant pressure drop (delta P/L) from 0 to 3.7 mmHg/cm-clot to drive fluid permeation, various regimes of lytic agents were delivered into fine and coarse fibrin gels (3 mg/ml) and whole blood clots. Using plasmin (1 microM) delivered into pure fibrin or urokinase (1 microM) delivered into glu-plasminogen (2.2 microM)-laden fibrin, the velocity at which a lysis front moved across fibrin was greatly enhanced by increasing delta P/L. Lysis of fine and coarse fibrin clots by 1 microM plasmin at delta P/L of 3.67 and 1.835 mmHg/cm-clot, respectively, led to a 12-fold and 16-fold enhancement of the lysis front velocity compared to lysis without pressure-driven permeation. For uPA-mediated lysis of coarse fibrin at delta P/L = 3.67 mmHg/cm-clot, the velocity of the lysis front was 25-fold faster than the lysis front velocity measured in the absence of permeation. Similar permeation-enhanced phenomenon was seen for the lysis of whole blood clots. Without permeation, the placement of a lytic agent adjacent to a clot boundary led to a reaction front that moved at a velocity dependent on the concentration of plasmin or uPA used. Overall, these studies suggest that transport phenomena within the clot can play a major role in determining the time needed for reperfusion during fibrinolysis.

Increased frequency of apolipoprotein B signal peptide sp24/24 in patients with coronary artery disease. General allele survey in the population of Taiwan and comparison with Caucasians

Apolipoprotein B (apoB) signal peptide (sp) polymorphism was characterized by polymerase chain reaction in blood samples of 58 coronary artery disease (CAD) patients and 319 control individuals of Chinese Han ethnic origin in Taiwan. In the CAD group, 77% of the observed alleles were sp27 (sp with 27 amino acids), and the remaining 23% sp24 (sp with 24 amino acids). The frequency distributions of the apoB sp allele in the control group were 0.81 for sp27 and 0.19 for sp24. The genotype distributions were 0.64 sp27/27, 0.26 sp27/24 and 0.10 sp24/24 in the CAD group; 0.64 sp27/27, 0.33 sp27/24 and 0.03 sp24/24 in the control group. The frequency of sp24/24 was significantly higher (p = 0.012) in the CAD group than in the control group. Several studies have shown that the frequency of sp24/24 is higher in hyperlipidemic than in normolipidemic groups. This marker is probably in linkage disequilibrium with some other atherogenic genes. Our study shows that the differences in both apoB signal peptide alleles and sp27/27 and sp27/24 genotype distributions are statistically significant between the Taiwanese and Caucasians.

Interaction of hamster submaxillary sialyl-Tn and Tn glycoproteins with Gal, GalNAc and GlcNAc specific lectins

Hamster submaxillary glycoprotein (HSM), one of the simplest glycoproteins among mammalian salivary mucins, is composed of approximately equivalent amounts of protein, hexosamine and sialic acid. The Thr and Ser residues in the protein core account for more than half of all of the amino acid residues, while Lys, Glu, Pro and Ala are the major components of the remaining portion of amino acids. The carbohydrate side chains of this mucous glycoprotein have mainly the NeuAc-GalNAc-(sialyl-Tn) sequence (HSM), and those of the desialylated product (HSM-Tn) are almost exclusively unsubstituted GalNAc residues (Tn determinants). The binding properties of sialyl-Tn (HSM) and asialo-HSM (HSM-Tn) glycoproteins were tested by precipitin assay with Gal, GalNAc and GlcNAc specific lectins. The HSM-Tn completely precipitated Vicia villosa (VVL both B4 and mixture of A and B), Maclura pomifera (MPL), and Artocarpus integrifolia (Jacalin) lectins; less than 2 micrograms of HSM-Tn were required for precipitating 50% of 5.0-6.3 micrograms lectin nitrogen added. HSM-Tn also reacted well with Helix pomatia lectin (HPL), Wistaria floribunda lectin (WFL) and Abrus precatorius agglutinin (APA) and precipitated in each case over 81% of the lectin nitrogen added. The reactivity of HSM-Tn with other lectins (Ricinus communis, RCA1; Dolichol biflorus, DBL; Viscum album, ML-I; Arachis hypogaea, PNA, and Triticum vulgaris, WGA) was weak or negligible. The activity of sialyl-Tn (HSM) was more restricted; HSM reacted well with Jacalin, moderately with MPL and VVL-B4, but was inactive or only weakly with the other lectins used. These findings indicate that HSM and its desialylated product (HSM-Tn) are highly useful reagents for the differentiation of Tn and T/Gal specific lectins and for anti-T, Tn and Af monoclonal antibodies.

Product-activation of Escherichia coli membrane-bound H(+)-ATPase (F1F0-ATPase) connected with epsilon-subunit at alkaline pH

Mutant strain AN1518 or AN2387 (Gly48-->Asp in epsilon-subunit) and partial revertant strain AN2540 (Gly48-->Asp, Pro47-->Ser in epsilon-subunit) of E. coli were used in a kinetic study of membrane-bound H(+)-ATPase. It was found that at pH 9.0 mutant strain AN1518 or AN2387 and partial revertant strain AN2540 gave a low initial rate, which increased with time until linearity was reached after 1-2 min. This phenomenon was prominent in mutant strains, but was not so obvious in wild-type AN346 of E. coli; this property is similar to F1-ATPase reported by Cox [1]. The mechanism of the slow activation of membrane-bound H(+)-ATPase was further investigated in this paper. The experimental results indicated that the hydrolytic rate of E. coli F1F0-ATPase that increased with time was membrane protein concentration- and pH-dependent, and that the product ADP produced during ATP hydrolysis is the factor causing the slow activation. Preincubation of the hydrolytic product ADP with a concentration comparable to that produced in the assay (20 microM) caused initial activation of ATP hydrolysis and abolished the slow activation. On the other hand, with the removal of ADP during the progress of the hydrolytic reaction it could be seen that the slow activation was abolished as well. In order to test the relationship between the epsilon-subunit and ADP involved in the slow activation, trypsin treatment was carried out on the membrane-bound H(+)-ATPase of various strains. The activation observed after trypsin treatment was on the order of AN1518 > AN2540 > AN346. The activation effects of ADP and trypsin were not found to be additive. This implies that ADP acted in a similar way to trypsin, i.e., to cause removal of the epsilon-subunit. A tentative mechanism of the slow activation was proposed that ADP, a product of ATP hydrolysis, could induce conformational changes of F1F0 at alkaline pH 9.0, thus weakening the binding strength between the epsilon-subunit and other subunits of F1F0, and resulting in removal or partial removal of the epsilon-subunit. This further impaired the coupling of F1 and F0 in the mutant strains; as a consequence the rate of ATP hydrolysis was increased.

[Study on the influence of enzymatic digestion upon tumor-infiltrating lymphocytes]

To get a long-term culture of tumor-infiltrating lymphocytes (TILs) is very difficult. The authors have investigated some suitable enzymes, their digestive conditions such as time and temperature, which may influence the viability and cytotoxicity of TILs. The results showed that collagenase II and IV could keep viability of TILs much longer than those treated with trypsin or hyaluronidase. The digestion with collagenase II or IV at 4 degrees C for 24 hours was much less damage to viability of TILs than those treated at 37 degrees C for one hour. The TILs, which digested at 4 degrees C for 24 hours, still had cytotoxicity against autologous tumor cells as long as sixty to seventy-five days.

Interaction of a novel Tn (GalNAc alpha 1-->Ser/Thr) glycoprotein with Gal, GalNAc and GlcNAc specific lectins

A naturally occurring Tn glycoprotein (Native ASG-Tn) with GalNAc alpha 1-->Ser/Thr as the only carbohydrate side chains, has been prepared from armadillo submandibular glands. In a quantitative precipitin assay, this glycoprotein completely precipitated Maclura pomifera (MPA), Vicia villosa B4 (VVL-B4) and Artocarpus integrifolia (Jacalin, AIL). It also reacted well with Helix pomatia (HPL) and Wistaria floribunda (WFL) and precipitated over 75% of the lectin nitrogen added, but poorly with Ricinus communis agglutinin (RCA1), ricin, peanut (Arachis hypogaea, PNA), Abrus precatorius agglutinin (APA) and Triticum vulgaris (WGA). This finding suggests that this novel Tn-glycoprotein may serve as a useful reagent for differentiating Tn and T specific monoclonal antibodies and lectins.

Effects of hyaluronan on collagen fibrillar matrix contraction by fibroblasts

Hyaluronan, found in high concentrations in fetal tissues, appears to have a major role in preventing scar formation in fetal wounds. Nevertheless, its role in inhibiting wound contractures associated with scar formation has not been clearly demonstrated. Our current study evaluated the effects of hyaluronan using an in vitro floating collagen fibrillar matrix (CFM) contraction model. The results demonstrated that the contraction of CFM by fibroblasts was significantly reduced when high concentrations (> 1 mg/mL) of hyaluronan were present in the media. This phenomenon is unique to hyaluronan, because chondroitin sulfate was ineffective in this connection. Fibroblast migration and proliferation studies indicated that high concentrations of hyaluronan stimulated cell migration and had no cytotoxic effects. Some possible mechanisms by which high concentrations of hyaluronan reduced CFM contraction by fibroblasts were proposed. Because the viscosity of a hyaluronan solution is much greater than that of chondroitin sulfate, and this increases with concentration, we investigated whether this property in itself was an important factor in inhibiting CFM contraction. No direct correlation was found between the viscosity of glycosaminoglycans and their ability to reduce CFM contraction.

Characterization of binding sites of a memory-enhancing peptide AVP(4-8) in rat cortical synaptosomal membranes

The pentapeptide pGlu-Asn-Cyt-Pro-Arg [AVP(4-8), termed ZNC(C)PR in this article] has been found as a metabolite of arginine-vasopressin (AVP) in rat brain and has been shown to have potent memory-enhancing activity and to yield a series of biochemical events in brain tissues. [35S]ZNC(C)PR was chemically synthesized with high specific activity (232 Ci/mmol), and specific binding sites for ZNC(C)PR were located in synaptosomal membrane preparations of rat brain. We identified a specific binding site for ZNC(C)PR with a Kd of 3.12 nM and Bmax of 31 fmol/mg protein in anterior cortical synaptosomal membranes in the presence of 5 mM Ni2+. A comparison of synthetic analogues of ZNC(C)PR competing with [35S]ZNC(C)PR for binding to anterior cortical receptor are presented. ZDC(C)PR, a 2-aspartyl substitute of the 2-asparaginyl residue in ZNC(C)PR, had the most potent competition, but AVP did not show significant ability to compete for the receptor with ZNC(C)PR.

Longevity-determining genes in Caenorhabditis elegans: chromosomal mapping of multiple noninteractive loci

We have used chromosome mapping with polymorphic markers to define genetic components governing life span in the nematode Caenorhabditis elegans. A complex recombinant-inbred population was derived from an interstrain cross, yielding > 1000 genotypes, each a composite of homozygous segments from the two parental strains. Genotypes were analyzed for the last-surviving 1-5% of worms in aging cohorts, and for young controls, by multiplex polymerase chain reaction using polymorphic markers to distinguish the parental alleles. We identified five regions of the genome at which one parental allele was significantly enriched in long-lived subpopulations. At four of five loci, the same alleles were selected in aging cohorts maintained under two different conditions, implying that these genes determine life span in differing environments.

Structural features of the Clostridium thermocellum cellulase SS gene

The Clostridium thermocellum cellulase SS is a subunit of the extracellular cellulase complex (cellulosome). It has previously been shown that SS, hydrolyzes crystalline cellulose synergistically with another subunit, SL. To study this synergism further, the authors cloned the gene coding for SS (celS) and compared its sequence to other known cel genes. The celS, although unique in its DNA sequence, has many structural features similar to those found in other cel genes. These features include a ribosome biding site, signal peptide sequence, the existence of a conserved reiterated amino acid sequence, and a palindromic structure downstream from its open reading frame.

DNA polymorphisms of apolipoprotein B in the population of Taiwan

Four apolipoprotein B (apoB) genetic polymorphisms, the AluI, XbaI, MspI and EcoRI restriction fragment length polymorphisms (RFLPs), were analyzed for 162 individuals in Taiwan by polymerase chain reaction. Allele frequency determination revealed that this population has 0.86 AluI- (A-), 0.99 XbaI- (X-), 1.0 MspI+ (M+), and 0.98 EcoRI+ (E+) alleles. Major genotypes were A-/A- (0.75), X-/X- (0.98), M+/M+ (1.0) and E+/E+ (0.96). There were 0.22 A-/A+, 0.02 X-/X+ and 0.04 E+/E- heterozygous genotypes and one minor homozygous A+/A+ (0.03) genotype. The XbaI allele frequency is similar to that found in the Japanese population (XbaI- 0.96), but is significantly different from that in Caucasians (XbaI- 0.31-0.54). Significant differences (p < 0.001) between the Taiwanese and Caucasians were also observed for the AluI, EcoRI and MspI RFLP alleles of the apoB gene. More heterozygous genotypes are observed in Caucasians than in the Taiwanese.

Cloning and DNA sequence of the gene coding for Clostridium thermocellum cellulase Ss (CelS), a major cellulosome component

Clostridium thermocellum ATCC 27405 produces an extracellular cellulase system capable of hydrolyzing crystalline cellulose. The enzyme system involves a multicomponent protein aggregate (the cellulosome) with a total molecular weight in the millions, impeding mechanistic studies. However, two major components of the aggregate, SS (M(r) = 82,000) and SL (M(r) = 250,000), which act synergistically to hydrolyze crystalline cellulose, have been identified (J. H. D. Wu, W. H. Orme-Johnson, and A. L. Demain, Biochemistry 27:1703-1709, 1988). To further study this synergism, we cloned and sequenced the gene (celS) coding for the SS (CelS) protein by using a degenerate, inosine-containing oligonucleotide probe whose sequence was derived from the N-terminal amino acid sequence of the CelS protein. The open reading frame of celS consisted of 2,241 bp encoding 741 amino acid residues. It encoded the N-terminal amino acid sequence and two internal peptide sequences determined for the native CelS protein. A putative ribosome binding site was identified at the 5' end of the gene. A putative signal peptide of 27 amino acid residues was adjacent to the N terminus of the CelS protein. The predicted molecular weight of the secreted protein was 80,670. The celS gene contained a conserved reiterated sequence encoding 24 amino acid residues found in proteins encoded by many other clostridial cel or xyn genes. A palindromic structure was found downstream from the open reading frame. The celS gene is unique among the known cel genes of C. thermocellum. However, it is highly homologous to the partial open reading frame found in C. cellulolyticum and in Caldocellum saccharolyticum, indicating that these genes belong to a new family of cel genes.

Defining carbohydrate specificity of Ricinus communis agglutinin as Gal beta 1-->4GlcNAc (II) > Gal beta 1-->3GlcNAc (I) > Gal alpha 1-->3Gal (B) > Gal beta 1-->3GalNAc (T)

To define carbohydrate specificity of Ricinus communis agglutinin (RCA1), the combining site of RCA1 was further characterized by quantitative precipitin (QPA) and precipitin-inhibition assays (QPIA). Among the oligosaccharides tested for QPIA, Gal beta 1-->4GlcNAc (II, human blood group type II precursor sequence) was found to be 7.1 times more active than Gal beta 1-->3GalNAc (T, Thomsen-Friedenreich sequence) and about 1.7 times more active than the other three disaccharides tested--Gal beta 1-->4Man, Gal beta 1-->3DAra and Gal beta 1-->6GalNAc. Gal alpha 1-->4Gal, the receptor of the uropathogenic E. coli ligand was 3.6 times less active than the II sequence. These results indicate that the beta 1-->4 linkage of the terminal Gal to subterminal GlcNAc is important as this beta 1-->4GlcNAc sequence is at least 1.6 times more active than other types of disaccharides. Among the glycoproteins examined for QPA, native and desialized bovine submandibular glycoproteins, native and desialized human plasma alpha 1-acid glycoproteins, as well as crude hog stomach mucin and its three mild acid hydrolyzed products reacted well with the lectin. These glycoproteins precipitated over 75% of the lectin nitrogen added indicating that RCA1 has the ability to recognize Gal beta 1-->4/3GlcNAc and/or the related residues at the non-reducing ends and at positions in the interior of the chains. However, Tn (GalNAc alpha 1-->Ser/Thr sequence) rich glycoproteins such as desialized ovine submandibular glycoprotein and desialized armadillo salivary glycoprotein, in which over 90% of the carbohydrate side chains are Tn determinants with none or only a trace of I/II or T determinants, precipitated poorly with RCA1. From the present and previous results obtained, the carbohydrate specificity of RCA1 can be constructed and summarized in decreasing order by lectin determinants as follows: II (Gal beta 1-->4GlcNAc) > I (Gal beta 1-->3GlcNAc) > E (Gal alpha 1-->4Gal) and B (Gal alpha 1-->3Gal) > T (Gal beta 1-->3GalNAc), while Tn (GalNAc alpha 1-->Ser/Thr) is a poor inhibitor.

Coronary artery disease risk predicted by plasma concentrations of high-density lipoprotein cholesterol, apolipoprotein AI, apolipoprotein B, and lipoprotein(a) in a general Chinese population

We measured lipid and lipoprotein concentrations in blood samples from control subjects and patients with coronary artery disease (CAD) in Taiwan. We found significant differences (P < 0.01) in the concentrations of high-density lipoprotein cholesterol (HDLC), apolipoprotein AI (ApoAI), apolipoprotein B (ApoB), and lipoprotein(a) [Lp(a)]. Concentrations of HDLC < 350 mg/L, ApoAI < 900 mg/L, ApoB > 800 mg/L, and Lp(a) > 200 mg/L occurred, respectively, 2.8, 5.2, 1.7, and 2.3 times more frequently in the patients than in the control group. If one considers HDLC at < 350 mg/L, ApoAI at < 900 mg/L, ApoB at > 800 mg/L, and Lp(a) at > 200 mg/L as separate risk factors for CAD, the ratio of individual patients to control subjects having 4, 3, 2, 1, or 0 risk factors was [symbol: see text] 9.4, 2.1, 0.2, 0.2, respectively. Individuals displaying three or more risk factors were found 15 times more frequently in the CAD group than in the control group. These risk factors may be used clinically for the prediction and prevention of CAD in the general population.

Coronary artery disease risk predicted by plasma concentrations of high-density lipoprotein cholesterol, apolipoprotein AI, apolipoprotein B, and lipoprotein(a) in a general Chinese population

We measured lipid and lipoprotein concentrations in blood samples from control subjects and patients with coronary artery disease (CAD) in Taiwan. We found significant differences (P &lt; 0.01) in the concentrations of high-density lipoprotein cholesterol (HDLC), apolipoprotein AI (ApoAI), apolipoprotein B (ApoB), and lipoprotein(a) [Lp(a)]. Concentrations of HDLC &lt; 350 mg/L, ApoAI &lt; 900 mg/L, ApoB &gt; 800 mg/L, and Lp(a) &gt; 200 mg/L occurred, respectively, 2.8, 5.2, 1.7, and 2.3 times more frequently in the patients than in the control group. If one considers HDLC at &lt; 350 mg/L, ApoAI at &lt; 900 mg/L, ApoB at &gt; 800 mg/L, and Lp(a) at &gt; 200 mg/L as separate risk factors for CAD, the ratio of individual patients to control subjects having 4, 3, 2, 1, or 0 risk factors was [symbol: see text] 9.4, 2.1, 0.2, 0.2, respectively. Individuals displaying three or more risk factors were found 15 times more frequently in the CAD group than in the control group. These risk factors may be used clinically for the prediction and prevention of CAD in the general population.

Intrathoracic extramedullary hematopoietic tumor in hemoglobin H disease

We report a Chinese patient with hemoglobin H (Hb H) disease who developed intrathoracic extramedullary hematopoiesis (EMH) 17 years following splenectomy for a blunt abdominal injury. The patient initially presented with extreme hyperbilirubinemia and multiple intrathoracic tumors. Hb H disease was diagnosed after investigation, and the marked jaundice, which declined gradually after supportive treatment, was attributed to his chronic hemolysis superimposed on an acute hepatitis C virus infection. A biopsy of the intrathoracic tumors revealed an EMH. Intrathoracic EMH, which is usually encountered in patients with beta-thalassemia and hereditary spherocytosis, has never been reported in Hb H disease. In areas where thalassemia is prevalent, EMH should be considered in the differential diagnosis of patients who have chronic anemia with asymptomatic intrathoracic tumor to avoid unnecessary surgical interventions.

Hair casts: a clinical and electron microscopic study

Hair casts were seen in 22 girls ranging in age from 4 to 13 years. They were localized to the frontal, vertex, and temporal areas. The number of affected hairs varied from one-tenth to one-third. Twenty of the 22 girls styled their hair in ponytails or pigtails. Compound root sheath casts were present in six of nine patients using 1% 4-dimethylaminocinamaldehyde stain. A mass of large polymorphous scales and solitary or clumped spores was seen on the surface of hair casts using scanning and transmission electron microscopy. Energy-dispersive x-ray microanalysis showed that elements of silicon, aluminum, and molybdenum were uniquely present in hair casts. We assume that tightly drawn braids, by causing local circulatory disturbances and inflammation of the scalp, may be one etiologic factor in the disorder.