Hybridization properties of oligodeoxynucleotide pairs bridged by polyarginine peptides

The hybridization properties of a series of probes, based on two 9mer oligodeoxynucleotides (designated as I and II) having an appended oligoarginine chain (Rn) to produce peptide-oligonucleotide conjugates or peptide-bridged oligonucleotide pairs (e.g. Rn-I or II-Rn-I), were investigated. For the double-linked probes, we found that the peptide bridge induces the two 9mers to bind complementary single-stranded DNA or RNA targets with substantially enhanced thermal stability. The resulting hybrid with complementary DNA was found to assume a 1:1 complex in the B conformation as judged by UV mixing curves and CD spectroscopy. Complexes of single or double-linked probes with complementary RNA exhibited sensitivity to RNase H digestion. The influence of the identity and chirality of the repeating unit in the bridge, the length of the bridge, the gap size and the salt concentration on the hybridization properties of this new class of oligonucleotide probes was also studied. Our data reveal that these compounds exhibit properties that should prove useful in the development of antisense strategies.

Gel shift assay: demonstration of enhanced binding of oligo(delta)-L-ornithine-oligodeoxynucleotide conjugates to complementary DNA and RNA

An increase in melting temperature for DNA:DNA duplexes had been observed previously (Zhu et al. Antisense Res. Dev. 3:349-356, 1993) when an oligo(delta)ornithine moiety was covalently appended to a short oligodeoxynucleotide. We now report the analysis of duplex formation by electrophoretic gel shift analysis. In the particular example studied, an increase in Tm of 4 degrees C was found to correspond to about a fivefold increase in binding constant. A similar enhancement by the appended cationic peptide was observed when the target strand was RNA. The use of a competitive assay format for avoidance of adsorptive loss at low concentrations (< 10(-7)M) of the oligonucleotide-oligo(delta)ornithine conjugate is presented.

[Trabeculectomy combined with extracapsular cataract extraction and posterior chamber intraocular lens implantation]

PURPOSE

To evaluate the effect of trabeculectomy combined with extacapsular cataract extraction and posterior chamber intraocular lens implantation (triple surgeries) on the patients of coexisting cataract and glaucoma.

METHODS

18 cases (19 eyes) of coexisting cataract and glaucoma treated by the triple surgeries were reviewed. Mean follow-up was 14.7 months (rangs from 2 to 20 months).

RESULTS

Intraocular pressure was controlled satisfyingly in all cases except one case required additional treatment of the anti-glaucoma drug. 78.9% of patients achieved 0.3 or better visual acuity. The operation complications consist of anterior uveitis and hyphaema. However, all of them were controlled within 14 days.

CONCLUSION

The triple surgeries are safe and have definite effect on controlling the IOP and improving visual acuity.

Drug-induced heat-shock preconditioning improves postischemic ventricular recovery after cardiopulmonary bypass

BACKGROUND

Heat-stress preconditioning of mammalian heart has been found to confer protection against ischemic reperfusion injury. Heat shock is generally provided by warming the animal by mechanical means, which is often impractical in a clinical setting. Amphetamine, a sympathomimetic drug, can elevate the body temperature as a result of enhanced endogenous lipolysis. In this study, we examined the effects of heat shock induced by amphetamine on postischemic myocardial recovery in a setting of coronary revascularization for acute myocardial infarction.

METHODS AND RESULTS

Adult Yorkshire swine were injected with amphetamine (3 mg/kg IM) (n = 12), and body temperature was continuously monitored. For control studies, the pigs were injected with saline (n = 12). Five swine in each group were killed after 3 hours to obtain biopsies of vital organs to measure heat-shock protein (HSP) mRNAs. After 40 hours, the remaining 7 pigs in each group were placed on cardiopulmonary bypass, and the isolated, in situ heart preparations were subjected to 1 hour of occlusion of the left anterior descending coronary artery followed by 1 hour of global hypothermic cardioplegic arrest and 1 hour of reperfusion. Postischemic myocardial performance was monitored by measuring left ventricular (LV) pressure, its dP/dt, myocardial segment shortening, and coronary blood flow. Cellular injury was examined by measurement of creatine kinase release. The antioxidant enzymes superoxide dismutase and catalase were also assayed. Amphetamine treatment was associated with the induction of mRNAs for HSP 27, HSP 70, and HSP 89 in all the vital organs, including heart, lung, liver, kidney, and brain. Amphetamine also enhanced superoxide dismutase and catalase activities in the heart. Significantly greater recovery of LV contractile functions was noticed, as demonstrated by improved recovery of LV developed pressure (61% versus 52%), LV dP/dtmax (52% versus 44%), and segment shortening (46.2% versus 10%) and reduced creatine kinase release in the amphetamine group.

CONCLUSIONS

The results demonstrate that amphetamine can induce whole-body heat shock that can precondition the heart, enhancing cellular tolerance to ischemia-reperfusion injury. Amphetamine is a sympathomimetic drug that may be used for preconditioning.

An enzyme-linked immunosorbent assay using biotinylated heparan sulfate to evaluate the interactions of heparin-like molecules and basic fibroblast growth factor

Basic fibroblast growth factor (bFGF) is a member of the heparin-binding growth factor family that interacts with cell surface heparan sulfate (HS) proteoglycans and extracellular matrix heparin. Here we report the development of a simple and sensitive assay that used biotinylated HS or heparin to bind to bFGF coated onto 96-well microtiter plates. Bound labeled HS or heparin was reacted with enzyme-linked streptavidin and results were recorded as optical density. Increased molar excess of biotin resulted in increased incorporation of biotin and higher signal without compromising binding. Glycosaminoglycans and modified heparins were assayed for their ability to compete with biotinylated HS for binding to bFGF. Inhibition of that binding by heparin and HS but not by chondroitin sulfate A or C, dermatan sulfate, or keratan sulfate demonstrated the specificity of the glycosaminoglycan binding. Structural modifications of heparin produced various degrees of inhibition with high structural specificity. Although removal of N-sulfates or 2,3-O-sulfate groups resulted in significant loss of inhibition, removal of 6-O-sulfates had little affect on binding. Carboxyl reduction or N-acetylation following N-desulfation produced heparinoids with moderate changes in binding capacity. Results from this assay are in agreement with previous data from our laboratory and reports from other researchers with respect to the specificity of glycosaminoglycan binding to bFGF and the role of 2,3-O- and 6-O-sulfate groups of heparin. The flexibility of this assay, in both the amount of label incorporated and the variability of solid substrate, makes this an excellent tool to study other heparin binding proteins.

Characterization of the SpHE promoter that is spatially regulated along the animal-vegetal axis of the sea urchin embryo

To understand how the maternally determined animal-vegetal polarity of the sea urchin embryo is established, we have begun to examine the regulatory apparatus of the gene encoding the Strongylocentrotus purpuratus hatching enzyme (SpHE). Previous studies have shown that the pattern of SpHE mRNA accumulation reflects the animal-vegetal developmental axis in that transcription is strongly upregulated during early cleavage in more animal blastomeres, but not in those around the maternally specified vegetal pole of the 16-cell embryo [Reynolds et al., Development 114, 769-786 (1992)]. Tests of SpHE promoter function in vivo using chloramphenicol acetyltransferase and beta-galactosidase enzymatic reporters define a regulatory region within several hundred nucleotides of the transcription initiation site. This region is sufficient to mediate both strong expression in the early blastula and spatially correct transcription. However, neither this region nor longer upstream sequences are sufficient to reproduce the transcriptional downregulation after very early blastula stage that is observed for endogenous genes. Biochemical assays of protein-DNA interactions within the regulatory region identify at least nine sites binding at least six different factors. These cis elements include Otx (an orthodenticle homologue), CCAAT, ets-related, and three unidentified motifs. Deletions and/or replacements of these cis-elements, alone and in combination, indicate that no single factor is essential for SpHE promoter activity, but instead that various combinations of subsets of these elements are capable of eliciting levels of transcription similar to those of the unaltered regulatory region. This density of regulatory elements is consistent with the intense transcription of endogenous SpHE genes during cleavage.

Low-power phase conjugation in push-pull azobenzene compounds

Push-pull azobenzene compounds were synthesized by the diazocoupling reaction, and low-power phase conjugation of azobenzene-compound-doped poly(methyl methacrylate) films was studied with a He-Ne laser at 632.8 nm. It is shown that this kind of polymer has appreciable third-order optical nonlinearity, with a chi((3)) of approximately 10(-4) esu in the tail of absorption.

[Determination of modulus of elasticity of human periodontal membrane]

The modulus of elasticity of periodontal membrane, as an essential parameter indicating the mechanical character of periodontal membrane, is very important in biomechanical studies (e.g. finite element stress analysis and photoelastic analysis) of dental restoration. However, determination of modulus of elasticity of human periodontal membrane has not been reported in China, and there are differences among the foreign reports. In this study, 135 periodontal samples were collected from fresh teeth and alveoli of 6 healthy adults. Drawing and compressing test were performed. The results showed that the tensile modulus of elasticity of human periodontal membrane is between 3.35 and 4.59MPa and the compress modulus of elasticity 0.5402(+/- 0.348) MPa.

Enhancement of cardiac function by cyclocreatine in models of cardiopulmonary bypass

This study tests the hypothesis that the administration of cyclocreatine prior to global ischemia enhances recovery of cardiac function during reperfusion. Two models were used. First, in a Langendorff-working heart model of normothermic cardioplegic arrest, rats (n = 6 per group) were injected intravenously with saline or cyclocreatine (600, 300, or 150 mg/kg). After 30 min or 2 h, hearts were excised and perfused in the Langendorff mode for 5 min and then in the working heart mode for 20 min. Normothermic arrest was induced by infusing warm St. Thomas solution once; then hearts were kept at 37 degrees C for 40 min. Following arrest, hearts were reperfused in the Langendorff mode for 15 min and then in the working mode for 30 min. Cyclocreatine consistently produced significantly better recovery of aortic flow and cardiac output compared to that of saline hearts. Second, in an intact canine model of cold cardioplegic arrest, adult mongrel dogs (n = 3 to 6 per group) underwent aortic cross-clamping for 1 h, followed by reperfusion on bypass for 45 min and off bypass for 4 h. Dogs were injected intravenously with saline or cyclocreatine (500 mg/kg) for 1 h before experiment. Post-bypass segmental contractility and cardiac output were significantly better in cyclocreatine hearts compared to that of controls. In a limited study, after a 3 h aortic cross-clamp time, cyclocreatine hearts achieved 91% baseline function while control hearts failed after 2 h. Results of this study suggest that cyclocreatine, without inotropic or chronotropic effect, protects the heart from global ischemic injury.

Biological effects of carbon ions with medium energy on plant seeds

The biological effects of 46.6 MeV/u 12C6+ ions on four kinds of plant seeds were studied at the Heavy Ion Research Facility in Lanzhou (HIRFL), Institute of Modern Physics (IMP), Academia Sinica. The results show that germination of the seeds is inhibited by exposure to ions. In root tip cells of irradiated seeds, a great variety of chromosomal aberrations were observed. Sensitivities in terms of inhibition of germination and induction of chromosomal aberrations in the four species are correlated.

[Clinical significance of urodynamic study in benign prostatic hyperplasia]

Urodynamic study, including UFR, cystometry, UPP, and EMG was carried out in 74 patients with benign prostatic hyperplasia (BPH) during the past 5 years. The correlations of prostate volume (57.3 +/- 6.3 ml), prostate length (4.94 +/- 1.23 cm) and detrusor pressure (6.54 +/- 4.73 kPa) were analysed. The results showed that urodynamic study plays an important role in indicating the time and method of operative treatment and predicting the prognosis of BPH operation. The fistularization of the bladder should be performed on the patients with the bladder disfunction. The measurement of the urethral resistance is of value in the diagnosis of posterior urethra obstruction than that of UFR.

Synthesis of oligoarginine-oligonucleotide conjugates and oligoarginine-bridged oligonucleotide pairs

Conjugates consisting of oligoarginine peptides linked to oligodeoxynucleotides have been synthesized, including a new type of conjugate, in which a pair of oligonucleotides is bridged by a cationic peptide. Two different 9-mer oligonucleotides were conjugated to the terminal cysteine residues of the peptide series H-Cys-(Arg)n-Cys-NH2 (n = 3, 5, 7). Different thiol protecting groups were utilized on the amino- and carboxy-terminal cysteine residues of the peptide to allow selective attachment to the 3'- or 5'-terminus of each specific oligonucleotide. The conjugates containing oligoarginine peptides were purified by anion-exchange chromatography, and their structures were confirmed by polyacrylamide gel electrophoresis and amino acid analysis.

Improved postischemic ventricular functional recovery by amphetamine is linked with its ability to induce heat shock

Heat shock has been shown to increase the cellular tolerances to ischemic injury. In this study, we examined the effects of heat shock induced by amphetamine on postischemic myocardial functional recovery in a setting of coronary revascularization for acute myocardial infarction. Intramuscular injection of amphetamine (3 mg/kg, i.m.) to pigs increased the body temperature to 42.5 degrees C within 1 h, and maintained this temperature for an additional 2 h. Fourty h after the amphetamine injection, the pigs were placed on by cardiopulmonary bypass and then isolated, in situ heart preparations were subjected to 1 h of global hypothermic cardioplegic arrest and 1 h of normothermic reperfusion. Postischemic myocardial performance was monitored by measuring left ventricular (LV) pressure, its dp/dt, myocardial segmental shortening (%SS), and coronary blood flow. Cellular injury was examined by measuring creatine kinase (CK) release. Biochemical measurements included quantification of plasma catecholamines and study of the induction of heat shock gene expression and antioxidative enzymes in the heart tissue. The results of this study indicated significantly greater recovery of LV contractile functions by amphetamine as demonstrated by improved recovery of LVDP (61% vs 52%), dp/dtmax (52% vs 44%), and segmental shortening (46.2% vs 10%). Myocardial CK release was significantly reduced in the amphetamine group. Furthermore, amphetamine pretreatment was associated with the induction of heat shock protein (HSP) 27 mRNA and stimulated Cu/Zn-superoxide dismutase and catalase levels, suggesting that amphetamine mediated improved postischemic ventricular recovery might be linked with its ability to induce heat shock and stimulate antioxidant enzymes.

Structural features in heparin which modulate specific biological activities mediated by basic fibroblast growth factor

The biological activity of basic fibroblast growth factor (bFGF) is influenced greatly by direct binding to heparin and heparan sulphate (HS). Heparin-derived oligosaccharides have been utilized to determine the structural requirements present in the polymer that account for binding to bFGF. We had previously demonstrated that fragments > 6 mer can inhibit the interaction between cell surface heparan sulphate proteoglycan (HSPG) and bFGF, and bFGF-induced proliferation of adrenocortical endothelial (ACE) cells. In contrast, oligosaccharides > 10 mer can enhance the binding of bFGF to its high-affinity receptor or support bFGF-induced mitogenesis in ACE cells (Ishihara et al., J. Biol. Chem., 268, 4675-4683, 1993). We have extended these studies to size- and structure-defined oligosaccharides from heparin, 2-O-desulphated (2-O-DS-) heparin, 6-O-desulphated (6-O-DS-) heparin, carboxy-reduced (CR-) heparin and carboxy-amidomethylsulphonated (AMS-) heparin. Oligosaccharides from these polymers were fractionated on a bFGF-affinity column and were assessed as inhibitors or enhancers of specific bFGF-derived biological activities. The results of these studies indicate that both 2-O-sulphate and the negative charge of the carboxy group [L-iduronic acid (IdoA) residues] are required for specific interactions of heparin-derived oligosaccharides with bFGF and for modulation of bFGF mitogenic activity. In addition, the charge of the carboxy groups in uronic acids can be replaced by other functional groups with a negative charge, such as the amidomethyl sulphonate moiety described here.

Enhancement of the recovery of rat hearts after prolonged cold storage by cyclocreatine phosphate

The present study determined whether the administration of cyclocreatine phosphate (CCrP) prior to ischemia can enhance the recovery of rat hearts hypothermically preserved for a prolonged period. Rats (n = 6 per group) were injected intravenously with 1 ml saline or CCrP (500 mg/kg). After 2 hr, hearts were excised and arrested by an infusion of University of Wisconsin solution. Saline hearts were then incubated in 40 ml UW, while CCrP hearts were incubated in 40 ml UW containing 100 mg CCrP; a mixture that is now referred to as Hartford Hospital (HH) solution. After 6 hr of storage at 4 degrees C, hearts were reperfused in the Langendorff mode for 15 min and then in the working heart mode for 30 min. Results indicated that the recovery of cardiac function--measured as aortic flow, coronary flow, cardiac output, stroke volume, and stroke work--was significantly better in CCrP group (50-55% baseline) compared with that of saline hearts (20-25%). Although no difference in enzyme leakage (i.e., creatine kinase) or lactate was detected between the two groups, the increase in heart weight after the initial 6-hr storage was significantly higher in saline hearts compared with that of CCrP hearts. Results of this study support the conclusion that CCrP treatment provides improved functional recovery after prolonged hypothermic preservation.

Biphoton holographic storage in Methyl Orange and Ethyl Orange dyes

Biphoton holograms are recorded by a He-Ne laser in Methyl Orange and Ethyl Orange dyes on exposure to a 514.5-nm argon-ion laser, and the dynamic of holographic recording is reported. The recording utilizes an unusual photochemistry that is due to either to a triplet-triplet transition from a long-lived triplet lower state of the cis configuration or a transition back to the trans state.

"Natural" presentation of human papillomavirus type-16 E7 protein to immunocompetent mice results in antigen-specific sensitization or sustained unresponsiveness

We have used a mouse model that utilizes the exclusively epithelial nature of human papillomavirus (HPV) infections to investigate the in vivo immune response to the E7 protein of human papillomavirus type-16. A keratinocyte cell line expressing E7 protein has been established and grafted onto syngeneic mice using a transplantation technique that permits the reformation of a differentiated epithelium on a granulation tissue bed. In this way viral antigens may be presented to the immune system in a way comparable to natural infection. A delayed-type hypersensitivity (DTH) response was studied post grafting by intradermal challenge with recombinant E7 protein. A significant response to E7 has been demonstrated in this way; however, priming with a low amount of HPV-16 E7 antigen induces immunological unresponsiveness, as measured by a loss of DTH reactivity to the protein, and persistence of keratinocytes expressing E7. Lymphocytes from mice exhibiting DTH reactivity have been shown to proliferate when stimulated with purified recombinant E7 protein in vitro, while immunoperoxidase staining of tissue from the sites of immunologically-induced inflammation has defined the cell infiltrate to be phenotypically characteristic of DTH. The observations reported here have important implications for vaccine strategy.

Molecular cloning and expression of a glycosaminoglycan N-acetylglucosaminyl N-deacetylase/N-sulfotransferase from a heparin-producing cell line

Heparin has a higher content of N-sulfated glucosamine and L-iduronic acid than heparan sulfate. Deacetylation of N-acetylglucosamine followed by N-sulfation may be important steps differentiating the biosynthesis of these glycosaminoglycans. We have cloned, by cross-hybridization with the cDNA from rat liver heparan sulfate N-deacetylase/N-sulfotransferase, a protein from a heparin synthesizing mastocytoma derived cell line called MST. This protein, which has both N-deacetylase/N-sulfotransferase activities, has a predicted amino acid sequence homology of 70% with the above rat liver enzyme and is unique for the following reasons. 1) It was found to be encoded by a 3.8-kilobase mRNA that was unique to heparin-producing cells; an 8.5-kilobase mRNA encoding the rat liver enzymes has been found to occur in all mammalian cells tested on the basis of nucleic acid cross-hybridization; 2) the protein overexpressed in COS cells in its full-length transmembrane form or as a soluble secreted protein A chimera displayed ratios of N-deacetylase to N-sulfotransferase activities that were 4-8-fold higher than that observed for the enzyme found in liver that is involved in the biosynthesis of heparan sulfate. These results suggest that the MST-derived enzyme is probably unique to the production of heparin in mast cells.

Postischemic deterioration of sarcoplasmic reticulum: warm versus cold blood cardioplegia

Impaired cardiac sarcoplasmic reticulum (SR) function, as evidenced by reduced SR Ca2+ uptake rate and decreased SR Ca(2+)-adenosine triphosphatase activity, has been found in postischemic "stunned" myocardium and in hearts subjected to hypothermic arrest. In this study, we compared the effects of retrograde continuous coronary sinus warm blood cardioplegia (WBC) and retrograde intermittent cold blood cardioplegia (CBC) on cardiac SR function and postischemic ventricular functional recovery in pig hearts. Twelve in situ isolated pig hearts supported by cardiopulmonary bypass were subjected to 120 minutes of cardioplegic arrest with either WBC (37 degrees C) or CBC (6 degrees to 10 degrees C), followed by 60 minutes of 37 degrees C reperfusion. Left ventricular global contractile function and coronary blood flow were measured before arrest and during reperfusion. Cardiac SR was isolated from left ventricular biopsy specimens, and 45Ca2+ uptake by SR and SR Ca(2+)-adenosine triphosphatase activity were determined. The recovery of left ventricular global contractile function as indicated by the maximum of the first derivative of left ventricular pressure was significantly improved in the WBC group compared with that of the CBC group (70% versus 46%; p < 0.05). The SR Ca(2+)-adenosine triphosphatase activity was better preserved after 60 minutes reperfusion in WBC compared with CBC (0.31 +/- 0.02 versus 0.20 +/- 0.03 microM Pi/min/mg protein, p < 0.05), and the recovery of SR Ca2+ uptake was significantly improved by WBC compared with CBC (1.15 +/- 0.12 versus 0.83 +/- 0.04 microM Ca2+/min/mg protein; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-1 alpha preconditioning reduces myocardial ischemia reperfusion injury

BACKGROUND

Interleukin-1 (IL-1) has been shown to induce superoxide dismutase (SOD) activity and to express heat shock protein (HSP). Since the reperfusion of ischemic heart is associated with the reduction of antioxidative enzymes including SOD and expression of HSP, it was hypothesized that IL-1 could be beneficial against ischemic reperfusion injury.

METHODS AND RESULTS

Rats were injected with recombinant IL-1 alpha (30 micrograms/kg IP); after 48 hours, they were anesthetized and hearts were removed, isolated, and perfused by the Langendorff technique. Myocardial functions were studied by measuring left ventricular developed pressure (LVDP) and its maximum first derivative (LV dP/dt), and cellular injury was studied by estimating creatine kinase (CK) release. Induction of the expression of HSP27 mRNA and HSP27 protein was examined by Western blot analysis and Northern blot analysis, respectively. Antioxidant enzymes were assayed by enzymatic analysis. Our results indicated reduction of ischemic reperfusion injury by IL-1 alpha, as evidenced by better recovery in postischemic ventricular functions (LVDP [mm Hg]: control, 63 +/- 14; IL-1, 102 +/- 11; P < .05), increased coronary flow (mL/min) (control, 2.93 +/- 0.58; IL-1, 5.17 +/- 0.43; P < .03), and reduced creatine kinase release (IU/L) (control, 110 +/- 5.78; IL-1, 81.76 +/- 7.71; P < .01). IL-1 alpha induced the expression of HSP27 mRNA within 2 hours as examined by Northern blot analysis and the expression of HSP27 after 48 hours. In addition, hearts pretreated with IL-1 alpha for 48 hours and then subjected to 30-minute ischemia and 60-minute reperfusion enhanced the activities (nmol/min/mg protein) of Cu/Zn SOD (control, 1.55 +/- 0.22; IL-1 alpha, 2.92 +/- 0.04; P < .004), Mn-SOD (control, 4.54 +/- 0.19; IL-1 alpha, 6.33 +/- 0.09, P < .001), catalase (control, 15.53 +/- 0.37; IL-1 alpha, 21.67 +/- 0.72; P < .002), glutathione peroxidase (control, 17.49 +/- 0.35; IL-1 alpha, 25.87 +/- 0.58; P < .001), and glucose-6-phosphate dehydrogenase (control, 22.71 +/- 0.44; IL-1 alpha, 29.53 +/- 0.48; P < .001).

CONCLUSIONS

The results of this study indicate that low doses of IL-1 alpha can be used as a therapeutic agent to precondition a heart from ischemia reperfusion injury.

Regulation of biosynthesis of the basic fibroblast growth factor binding domains of heparan sulfate by heparan sulfate-N-deacetylase/N-sulfotransferase expression

Heparan sulfate-N-deacetylase/N-sulfotransferase catalyzes both the N-deacetylation and N-sulfation reactions that initiate the modification of the oligosaccharide backbone of heparan sulfate (HS). The glycosaminoglycan polymer appears to modulate the activity of growth factors by mediating their initial binding. To understand how the biosynthesis of these binding sites is regulated, a rat liver-derived cDNA encoding the above activities was overexpressed in a COS cell mutant (CM-15) that has reduced levels of the enzyme and binds poorly to immobilized basic fibroblast growth factor (bFGF). This resulted in increased synthesis of sulfated blocks of decasaccharide size or longer. These blocks exhibited high affinity binding to bFGF and contained a high content of 2-O-sulfated iduronate and at least five consecutive N-sulfated disaccharides. An increase in the synthesis of these high affinity blocks was not seen in transfected wild-type COS cells even though they showed a 4-fold increase of both enzyme activities, suggesting that once sufficient levels of highly sulfated blocks of saccharides with high affinity for bFGF are attained, no further synthesis of these domains occurs.