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PubMed1984

Immunotherapy with alginate-conjugated and alum-precipitated grass pollen extracts in patients with allergic rhinoconjunctivitis.

In order to compare the safety and the efficacy of two grass pollen extracts made from the same starting material, i.e. equal proportions of cocksfoot and timothy, a 3-year study was made on patients with hay fever. One product was a dialysed aqueous extract of pollens which was chemically conjugated to activated sodium alginate ( Conjuvac ). The other was a pyridine-extracted alum-precipitated crude extract (Allpyral). Forty patients with classical hay fever were admitted to the study. All gave positive result to prick and nasal/conjunctival testing with extracts of both cocksfoot and timothy grass. Thirty-five patients completed all 3 years of the study. Seventeen/eighteen Allpyral-treated and 17/17 Conjuvac -treated patients were subjectively improved. There was no significant difference in symptom scores between the two groups. Challenge tests showed a tendency to reduced sensitivity to allergen in the Conjuvac -treated but not in the Allpyral-treated group. The median values for specific IgG and IgE showed the same pattern of reaction as seen in earlier studies of pollen hyposensitization. There was, however, a greater increase of grass-specific IgG in the Conjuvac -treated patients. No serious adverse effects were seen in any of the treatment groups, but there were slightly fewer side effects in the Conjuvac group.

Adolescent↗
PubMed1990

A double-blind study of hyposensitization with an alginate-conjugated extract of Dermatophagoides pteronyssinus (Conjuvac) in patients with perennial rhinitis. II. Immunological aspects.

In a 2-year double-blind placebo controlled study an immunological evaluation was carried out on 33 patients (15 males, 18 females, mean age 29.2 years) with mite-induced perennial rhinitis who were submitted to specific immunotherapy (IT) with an alginate-conjugated extract of D. pteronyssinus. The behaviour of IgE, IgG, IgG1 and IgG4 antibodies specific to D. pteronyssinus and its major allergen Der p1 was characterized by assessment of their changes in serum, and changes in IgG in nasal secretions during the treatment. The placebo-treated patients did not show any significant variation in the levels of specific antibodies, while in the actively treated patients we found: a statistically significant decrease (P less than 0.005) of specific IgE, a statistically significant increase of specific IgG (P less than 0.005), IgG1 (P less than 0.005) and IgG4 (P less than 0.005) in serum and a statistically significant increase (P less than 0.001) of specific IgG in nasal secretions. The IgG response showed an early relative predominance of the IgG1 subclass and a late absolute predominance of IgG4 subclass, that confirmed the model of IgG4 restriction in prolonged allergen stimulation. No correlation was found between immunological and clinical data.

Adjuvants, Immunologic↗
PubMed1994

A double-blind, placebo-controlled study of immunotherapy with an alginate-conjugated extract of Parietaria judaica in patients with Parietaria hay fever.

A double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of immunotherapy (IT) with a partially purified alginate-conjugated extract of Parietaria judaica (Conjuvac Parietaria, Dome/Hollister-Stier) in patients suffering from rhinoconjunctivitis caused by Parietaria pollen. Eighteen patients (10 women, 8 men, mean age 35 years) received active treatment and 17 (10 women, 7 men, mean age 42.5 years) received placebo. Actively treated patients had significantly lower nasal symptom/medication scores (running nose P = 0.0087 and sneezing P = 0.048) during the Parietaria pollen season. Significant decreases in specific skin (P < 0.01), nasal (P < 0.05), and conjunctival (P < 0.01) reactivity to the Parietaria extract and significant increases of specific IgG (P < 0.001), IgG1 (P < 0.001), and IgG4 (P < 0.001) in actively treated patients, but not in placebo, were found. IT was well tolerated, the active extract inducing five mild systemic reactions (four rhinitis and one urticaria) and placebo two (rhinitis). A significant correlation was found between low skin reactivity and high specific IgG (P = 0.0002) and IgG4 (P = 0.036). These findings indicate that IT with a partially purified P. judaica extract is an effective and safe treatment for Parietaria pollen allergy. The correlation between low immediate skin reactivity and high specific IgG and IgG4 suggests that, at least in the studied cutaneous model, these antibodies may exert a blocking effect.

Adjuvants, Immunologic↗
PubMed1984

Properties of alginate lyases from marine bacteria.

Alginate lyases (EC 4.2.2.3) from two marine bacteria were isolated and partially characterized. A cell-bound lyase from isolate A3 had a molecular weight of approximately 100,000 and cleaved mannuronate blocks, apparently in an exo manner. A lyase recovered from the culture medium of isolate W3 was soluble in saturated ammonium sulfate, cleaved guluronate blocks, apparently in an endo manner, and had a molecular weight of 35,000. The thiobarbiturate test and urea-polyacrylamide gel electrophoresis were used to determine substrate specificity and mode of substrate cleavage by the enzymes.

Journal Article↗
PubMed1985

Distribution of Alginate Lyase Activity among Strains of Bacillus circulans.

Strains from four different DNA relatedness groups of Bacillus circulans showed apparent alginate lyase activity; the activity of three strains examined had mannuronidase specificity. A representative strain of group 4 also produced apparent inducible unsulfated chrondroitin lyase activity.

Journal Article↗
PubMed1986

Alginate beads as synthetic inoculant carriers for slow release of bacteria that affect plant growth.

Uniform synthetic beads were developed as carriers for the bacterial inoculation of plants. The beads are made of sodium alginate and skim milk and contain a large reservoir of bacterial culture which releases the bacteria at a slow and constant rate. The beads are biodegradable and produce no environmental pollution. The strength of the beads, the rate of bacterial release, and the time of their survival in the soil can be controlled by several hardening treatments. The final product, lyophilized beads, is simple to use and is applied to the seeds concomitantly with sowing. The released bacteria are available for root colonization immediately at seed germination. Dry beads containing bacteria can be stored at ambient temperature over a long period without loss of bacterial content; storage requires a limited space, and the quality control of a number of bacteria in the bead is simple. The level of plant inoculation with beads was similar to that with previously used peat inoculants, but the former method yielded more consistent results, as the frequency of inoculated plants was much higher. The former method provides a different approach for inoculation of plants with beneficial rhizosphere bacteria.

Journal Article↗
PubMed1994

Human immune response to Pseudomonas aeruginosa mucoid exopolysaccharide (alginate) vaccine.

Chronic lung infection with mucoid Pseudomonas aeruginosa is the major pathologic feature of cystic fibrosis. Previous studies suggested that a failure to produce opsonic antibody to the mucoid exopolysaccharide (MEP; also called alginate) capsule is associated with the maintenance of chronic bacterial infection. Provision of MEP-specific opsonic antibodies has therapeutic potential. To evaluate the ability of MEP to elicit opsonic antibodies, humans were immunized with two lots of MEP vaccine that differed principally in molecular size. Lot 2 had a larger average MEP polymer size. Both vaccines were well tolerated, but lot 1 was poorly immunogenic, inducing long-lived opsonic antibodies in only 2 of 28 vaccinates given doses of 10 to 150 micrograms. In contrast, at the optimal dose of 100 micrograms, lot 2 elicited long-lived opsonic antibodies in 80 to 90% of the vaccinates. The antibodies elicited by both lots enhanced deposition of C3 onto mucoid P. aeruginosa cells and mediated opsonic killing of heterologous mucoid strains expressing distinct MEP antigens. These results indicate that the polymers of MEP with the largest molecular sizes safely elicit opsonic antibodies in a sufficiently large proportion of vaccinates to permit studies of active and passive immunization of cystic fibrosis patients against infection with mucoid P. aeruginosa.

Adult↗
PubMedDate not supplied

Towards the development of a bioartificial pancreas: effects of poly-L-lysine on alginate beads with BTC3 cells.

A bioartificial tissue construct that consists of insulin-secreting cells entrapped in an alginate/poly-L-lysine (PLL) matrix offers a promising approach for the treatment of type I diabetes. Use of transformed cells has been proposed as a solution to the cell availability problem posed by islets. The growth characteristics of transformed cells in their sequestered environment and the effects of PLL on their metabolic and secretory activities have not yet been characterized. Our data demonstrate that mouse insulinoma beta TC3 cells proliferate while they are entrapped in both PLL-free and PLL-coated alginate beads. During this process, cell aggregates develop in the bead periphery, which increase in number and size with time. PLL is crucial for the long-term in vitro structural stability of beads, and it does not appear to affect the metabolic and secretory activities of entrapped beta TC3 cells. The implications of these findings in the development of a bioartificial pancreatic construct based on transformed cells are discussed.

Animals↗
PubMed2005

Encapsulated Escherichia coli in alginate beads capable of secreting a heterologous pectin lyase.

BACKGROUND: Production of heterologous proteins in the E. coli periplasm, or into the extracellular fluid has many advantages; therefore naturally occurring signal peptides are selected for proteins translocation. The aim of this study was the production in high yields of a recombinant pectin lyase that is efficiently secreted and the encapsulation of transformed E. coli cells for pectin degradation in a biotechnological process. RESULTS: The nucleotide sequence of Bacillus subtilis alpha-amylase's signal peptide was fused to the N-terminal of an heterologously expressed pectin lyase in E. coli BL21 [DE3]. Thus pectin lyase secretion was achieved into the extracellular growth medium. E. coli cells harboring the recombinant plasmid heterologously express pectin lyase to around 22% of the total cellular proteins, as it was estimated by SDS-PAGE and image analysis. IPTG induces the heterologously expressed enzyme, which is initially distributed extracellularly (7 hour) and later on at the periplasmic (9 hours) or cytosolic fraction (20 hours). No pectin lyase activity was found in the membranes fraction and in the inclusion bodies. Encapsulation of the recombinant strains of E. coli in alginate or alginate/silica beads 1:5 showed that pectin lyase could degrade effectively its substrate, for at least ten operational cycles. CONCLUSION: Secretion of an heterologously overexpressed pectin lyase in E. coli BL21 [DE3] was achieved in this study. For this purpose the signal peptide of alpha-amylase from B. subtilis was fused to the N-terminal domain of pectin lyase. Encapsulated E. coli BL21 [DE3] cells harboring pET29c/exPNL were used successfully for pectin degradation up to ten operational cycles indicating that under special conditions this might have biotechnological implementations.

Journal Article↗
PubMed2002

A novel gene delivery system in plants with calcium alginate micro-beads.

We have produced micrometer-sized calcium alginate beads referred to as "bio-beads" that encapsulate plasmid DNA molecules carrying a reporter gene. In order to evaluate the efficiency of the bio-beads in mediating genetic transfection, protoplasts isolated from cultured tobacco cells (BY-2) were transfected with bio-beads containing a plasmid that carries the modified green fluorescent protein gene CaMV35S-sGFP. With the bio-beads treatment, approximately ten-fold higher GFP expression was observed after 24 h incubation compared to that with the conventional method using a naked plasmid solution. Transfection was up to 0.22% efficient. These results indicate that bio-beads have a possibility for efficient transformation in plants.

Journal Article↗
PubMed2005

Antagonism of Gluconacetobacter diazotrophicus (a sugarcane endosymbiont) against Xanthomonas albilineans (pathogen) studied in alginate-immobilized sugarcane stalk tissues.

Xanthomonas albilineans, a pathogenic bacterium that produces leaf scald disease of sugarcane, secretes a xanthan-like gum that invades both xylem and phloem of the host. Xanthan production has been verified after experimental infection of stalk segments of healthy plants. Moreover, Gluconacetobacter diazotrophicus is a nitrogen-fixing endosymbiont of sugarcane plants that antagonizes with X. albilineans by impeding the production of the bacterial gum. The physiological basis of this antagonism has been studied using tissues of sugarcane stalks previously inoculated with the endosymbiont, then immobilized in calcium alginate and maintained in a culture medium for Gluconacetobacter. Under these conditions, bacteria infecting immobilized tissues are able to secrete to the medium a lysozyme-like bacteriocin that inhibits the growth of X. albilineans.

Bacteriocins↗
PubMed1995

Purification and characterization of extracellular alginate lyase from Enterobacter cloacae M-1.

An alginate lyase from the culture supernatant of Enterobacter cloacae M-1 was purified by ammonium sulfate precipitation, cation-exchange chromatography (SP-Toyopearl), and gel filtration (Ultrogel AcA44). The final preparation thus obtained showed a single band on SDS-PAGE. The purified enzyme had the molecular weight of 38,000 and 32,000 by SDS-PAGE and gel filtration, respectively. The pI of the enzyme was 8.9. The optimum pH and temperature for the enzyme reaction were around 7.8 and 30 degrees C, respectively. The enzyme was unstable on heating. EDTA completely inhibited the enzyme activity, but the activity was completely restored by the treatment with CaCl2. The enzyme was specific for poly-guluronate and produced several kinds of unsaturated oligomers from the gluluronate. This suggested that the enzyme could be classified as an endo poly-guluronate lyase.

Amino Acid Sequence↗
PubMed1998

[Spectroscopic investigations on sol-gel transition of alginate solutions by addition of cupric ion].

Viscosity measurements and 13C-NMR, UV/VIS, and Raman spectroscopic studies have been carried out of various concentration of alginate solutions undergoing sol-gel transition induced by addition of cupric cation. From analyses of the spectra, a qualitative explaination was suggested of the interaction mode of the coordination between functional groups and cupric ions, the conformational change of polychains and the behaviour of solvent molecules druing the process of sol-gel transition. The mechanisms of phase transition of our system induced by the heavy metal ion have been discussed.

English Abstract↗
PubMed1986

A multicenter trial of immunotherapy with alginate--conjugated grass pollen extract.

Conjuvac, a new generation of allergen extracts, has been developed to meet the need for improved characterization, purification, and standardization. Conjuvac consists of a dialyzed, standardized aqueous allergen extract chemically conjugated to a sodium alginate carrier and lyophilized in single-dose vials, thus ensuring stability until reconstituted with sterile water just before each injection. A preliminary study of Conjuvac 2 Grass by Pegelow (1984) involving a small number of patients showed this extract to have potential advantages. Accordingly, a study involving more patients was undertaken: two different maintenance dose levels of Conjuvac 2 Grass were investigated and compared to a pyridine-extracted, alum-precipitated two-grass extract called Allpyral, which in previous double-blind trials has been shown to be effective. The trial, which included 125 patients with hay fever and which extended over 2 years, involved ten allergists from seven European countries. Overall, the Conjuvac high-dose regimen proved slightly superior to Allpyral without any increased incidence of side effects, and all treatments stimulated marked increases in specific IgG levels without raising IgE levels.

Adolescent↗