Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 265621

[Lead content in alginates].

L Castagnola·J Wirz
View original source ↗Export metadata ↓

Abstract

Alginates containing a high level of lead may lead to health damages in dentists and their personnel. Walter and Söremark have pointed out these hazards. The author's investigations with the Perkin-Elmer absorption-photospectrometer shall show how high the lead content of the 25 brands of alginate sold in this country is. Ca 37, Protex and Algihard S contain sizeable amounts of lead. Recommendations are given towards the protection of dentist and assistant.

Explore related subjects

AlginatesDental AssistantsEnvironmental ExposureHumansLeadOccupational DiseasesEnglish AbstractJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

L Castagnola, J Wirz. 1977. [Lead content in alginates].. https://pubmed.ncbi.nlm.nih.gov/265621/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Occurrence of alginate gene sequences among members of the pseudomonad rRNA homology groups I-IV.

Total genomic DNA of 13 pseudomonads representing rRNA homology groups I-IV were screened for sequences homologous to four Pseudomonas aeruginosa alginate (alg) genes by Southern hybridization. Biotinylated probes for three structural genes (algA, algC and algD) and one regulatory gene (algR1) were prepared. Genomic DNA of strains representing group I (P. syringae pv. glycinea, P. viridiflava and P. corrugata) hybridized with all four gene probes. Hybridizing fragments were of differing sizes, indicating that evolutionary divergence among group I members has occurred. P. corrugata has not been reported to synthesize alginate. Genomic DNA from representatives of groups II-IV gave no or very weak hybridization with the probes except for algC. This study indicates that the ability to produce alginic acid as an exopolysaccharide among the pseudomonads is restricted to members of rRNA homology group I in agreement with earlier physiological studies.

Alginates↗
PubMed1979

A study of the reaction catalysed by alginate lyase VI from the sea mollusc, Littorina sp.

The molecular weight of polymeric alginic acid digested by alginate lyase (poly(1,4-beta-D-mannuronide) lyase, EC 4.2.2.3) was determined at various stages of the lysis. Low molecular weigh fragments were detected only after 60-100% lysis. Some high molecular weight fragments remained intact even after addition of a fresh aliquot of enzyme to the digest. The enzyme showed maximal activity at pH 5.6 in 0.05 M salt. Enzyme activity was stimulated by addition of 7.5 mM CaCl2 and 0.2 M NaCl, when the pH optimum was between 8 and 8.5. Only mannuronic acid was detected at the reducing end of fragments after exhausive enzymolysis, reduction and hydrolysis. On studying the reaction products by NMR, a double-bound signal (sigma = 5.98 ppm) was observed. A considerable decrease in intensity of the D-mannuronic acid residue signal was detected after hydrolysis of alginate lyase VI on poly-(ManUA-GulUA), but not poly(GulUA). The results suggest that alginate lyase VI may be an endoalginate lyase that splits glycoside bonds only between two mannuronic acid residues.

Alginates↗