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Biomedical subjects

A Linde

Publications and source records attributed to A Linde.

At least 271 records · Page 15Linked to original sources
PubMed1982

A retrospective study of microbiologic samples from oral mucosal lesions.

This report describes findings in microbial samples from 271 patients with lesions of the oral mucous membranes. Analyses were made on the basis of direct microscopy and cultivation on nonselective and selective media incubated under aerobic and anaerobic conditions. Growth of bacteria was semiquantitatively determined according to a five-grade scale. Among the 134 samples for direct microscopy, fungi in yeast as well as hyphae phase, were identified in 39 cases. Among the cultivated samples, Candida albicans was detected in 107 cases, of which 71 were full-denture wearers. Staphylococcus aureus, coliform bacteria and Klebsiella were the most frequently isolated "nonoral" bacteria. In some cases also Streptococcus pyogenes, Haemophilus influenzae, Pseudomonas or other gram-negative aerobic bacteria were found. In 84 cases the bacteria mentioned were registered as single "nonoral" infection, and in 63 cases combinations of "nonoral" species occurred. In 51 of these 63 cases C. albicans was also involved. In 31 cases a significant quantitative increase of one or more oral bacterial species was registered. In 93 cases there was no indication of a microbial cause of the lesion. On the basis of these microbial findings, it might be presupposed that in the majority of cases microorganisms were of primary or secondary pathogenic importance to the lesions.

Adolescent↗
PubMed1982

Craniofacial morphology and growth in the rat. Cephalometric analysis of the effects of a low calcium and vitamin D-deficient diet.

The influence of a low calcium and vitamin D-deficient diet on the growth and form of the skull of the growing rat was studied using a cephalometric radiographic technique. First, this technique was used to obtain an intra-individual cephalometric description of the normal growth and form of the skull at different ages during postnatal growth in the rat. It was shown that the methodological error and the biological variation between animals were significantly lower than the registered growth changes, thus demonstrating the suitability of the technique. In the animals fed the low calcium and vitamin D-deficient diet and impaired increase in body weight was found. This diet also caused changes in cranial dimensions, both when the deficient animals were compared with control animals of the same age and with control animals with the same weight. It was concluded that the vitamin D-free and low calcium diet caused a disturbed osteogenesis in growth sites determining the growth and form of the viscerocranium and its relation to the neurocranium.

Animals↗
PubMed1981

Non-collagenous proteins of rat dentin. Evidence that phosphoprotein is not covalently bound to collagen.

The non-collagenous proteins of rat dentin that remain firmly bound to the matrix after demineralization were studied in order to ascertain if they are covalently linked to insoluble dentin collagen. After solubilization with CNBr or with bacterial collagenase, unusually small amounts of dentin phosphoprotein were detected in the matrix. The phosphoprotein obtained by CNBr digestion of the matrix was separated from collagen peptides using two chromatographic steps. Thus even this small quantity of phosphoprotein found in decalcified rat dentin matrix was not covalently bound to collagen.

Amino Acids↗
PubMed1981

Antibody response to cytomegalovirus: a comparison between adult patients with neurological disease and uncomplicated infection.

Cytomegalovirus (CMV) infection in adults can cause neurological diseases such as the Guillain--Barré syndrome (GBS) and myelitis. The mechanism leading to the development of neurological damage is, however, still unknown. We have investigated the possibility that an abnormal humoral immune response, either weak or hyperactive, could be the cause. The antibody response of four patients with a primary CMV followed by neurological symptoms was compared to that of four age-matched controls with an uncomplicated infection. IgG and IgM antibodies to CMV early antigens (EA), late antigens (LA), and IgG antibodies to CMV immediate early antigens (IEA) were measured in consecutive serum samples. Comparison of titers indicated a longer time lapse between the onset of CMV infection and the development of symptoms in the group with neurological disease. We found no conclusive evidence of an abnormal humoral immune response to CMV in the patients with neurological disease compared to the patients with an uncomplicated infection.

Adolescent↗
PubMed1981

ATP-dependent uptake of Ca2+ by a microsomal fraction from rat incisor odontoblasts.

Intracellular vesicles containing alkaline phosphatase and Ca2+-ATPase activity were isolated in the microsomal fraction from free-dissected odontoblasts of rat incisors. The microsomal fraction was incubated with 45Ca2+ to study Ca2+ uptake. ATP stimulated Ca2+ uptake, whereas little uptake occurred without ATP. The maximal effect was obtained with 3mM ATP. The ATP-dependent uptake was linear for 2 h. Increasing the pH up to pH 8.2 resulted in an increased uptake. Mg2+ was stimulatory with an optimal effect at a 6mM concentration. Increasing concentrations of Ca2+ up to 100 micrometer enhanced the uptake. A correlation between Ca2+ uptake and Ca2+-ATPase in intracellular vesicles as well as a possible function in the calcification process are discussed.

Animals↗
PubMed1981

Nonocollagenous proteins of dentin. Isolation and partial characterization of rat dentin proteins and proteoglycans using a three-step preparative method.

The purpose of this study was to develop a method for fractionation of dentin proteins and proteoglycans into pools. The sequential procedure consisted of: (1) addition of 1.0 M CaCl2 to solutions of EDTA extracts of rat dentin in the presence of protease inhibitors to form a CaCl2 precipitate (Fraction I), (2) dialysis of the resultant supernatant against 0.1 M formic acid to form an acid precipitate (Fraction II), and (3) passage of the 0.1 M formic acid supernatant over a Sephadex G-50 column to obtain a high molecular weight, excluded peak (Fraction III) and a lower molecular weight, included peak (Fraction IV). Each of the four fractions was characterized by amino acid analysis, slab gel electrophoresis and ion-exchange chromatography on DEAE-cellulose. Fraction I contained almost exclusively phosphoproteins while Fraction II consisted of several acidic proteins, albumin, proteoglycans and a protein with a relatively low level of organic phosphate. A unique glycoprotein with an apparent Mr = 95,000 was found in Fraction III along with smaller amounts of other proteins, including albumin and a phosphoprotein with a relatively low level of organic phosphate. Fraction IV contained several low molecular weight, gamma-carboxyglutamate-containing proteins similar to those found in bone. The data show that the method selectively fractionates the proteins and proteoglycans of rat dentin. Furthermore the method is rapid and allows preparative steps to be performed in the presence of protease inhibitors. This new procedure should be a useful step in the comprehensive isolation of dentin proteins in experiments designed to study their detailed chemical nature and metabolism.

Albumins↗
PubMed1981

Ca2+-binding studies of the phosphoprotein from rat-incisor dentine.

Rat incisor dentine was demineralized and extracted with 0.25 M EDTA containing protease inhibitors. The extract was purified by chromatography on DEAE-cellulose and sulfonated polystyrene. The Ca2+-finding properties of the phosphoprotein were studied by dynamic dialysis and by using a Ca2+-selective electrode. Two different binding sites were detected with Kd = 0.9 X 10(-7) M and 1.1 X 10(-5) M and displaying a Ca2+-binding capacity of 127 and 176 mol bound Ca2+/mol protein, respectively, assuming a molecular weight of 30 000. Upon enzymatic dephosphorylation of the phosphoprotein, the highest affinity sites disappeared and those with the lowest affinity were reduced. The optimum for Ca2+ binding by the phosphoprotein occurred at pH 8.2. The specificity of the Ca2+ ion interaction with the phosphoprotein was investigated by studying the competitive nature of other divalent and monovalent cations. It was found that Ca2+ ions were to a large extent displaced from the phosphoprotein by other cations in physiological concentrations.

Animals↗
PubMed1980

Noncollagenous proteins of dentin. A re-examination of proteins from rat incisor dentin utilizing techniques to avoid artifacts.

Noncollagenous proteins (NCPs) were obtained rrom rat dentin using several precautionary measures to prevent artifactual degradation and losses of the proteins. Prior to demineralization, rat incisor dentin was extracted with 4 M guanidine hydrochloride (GdmCl) containing enzyme inhibitors. The only major component extracted with GdmCl was a proteoglycan fraction. Most of the NCPs were extracted when the incisors were decalcified with an EDTA solution containing protease inhibitors. The EDTA extract contained four types of macromolecules: acidic glycoproteins, gamma-carboxyglutamic acid (Gla)-containing proteins, phosphoproteins, and proteoglycans. With two exceptions, the apparent molecular weights of these NCPs were greater than 50,000. Our observations contrast sharply with the results obtained by others for human dentin NCPs and suggest that artifactual degradation and losses of some NCPs occurred in these previous studies. The organic phosphate-containing fraction was biphasic when the EDTA extract was chromatographed on DEAE-cellulose. Rechromatography of this fraction by two different procedures separated the material into a complex glycoprotein-containing fraction and, a single rat incisor phosphoprotein peak (RIP). Thus, the earlier interpretation by others that the biphasic nature of the RIP-containing fraction represents two widely differing phosphoprotein species was premature. Highly purified RIP, prepared by passage through a sulfonated polystyrene column, contained no cysteine, valine, methionine, leucine, phenylalanine, or arginine, and the level of phosphoseryl residues was higher than for any previous report. When this preparation of phosphoprotein was dephosphorylated (dP-RIP) and rechromatographed on DEAE-cellulose, a partial separation into two fractions was observed. Automated Edman degradation of fraction dP-RIP suggested the presence of two NH2-terminal sequences: Asp-Asp-Asp-Asn and Asp-Asp-Pro-Asn. However, this material displayed a single protein band when applied to 7.5% sodium dodecyl sulfate polyacrylamide gel electrophoresis and stained with Coomassie brilliant blue. The apparent molecular weight of dP-RIP, compared to standard globular proteins, was about 72,000. The data suggest that rat dentin contains at least two major molecular species of RIP that are closely related in size and-structure. In addition, preliminary evidence suggested that other minor forms of related phosphoproteins may exist.

Amino Acid Sequence↗
PubMed1980

Comparative studies of phosphoprotein preparations from rat incisor dentin.

Phosphoprotein was obtained from rat incisor dentin either by extraction at elevated ionic strength after acetic acid demineralization, or by extraction simultaneous with demineralization in neutral EDTA solution. Purification of solubilized proteins was achieved by Sepharose 4B and DEAE-cellulose chromatography. Polyacrylamide gel electrophoresis of the material from the two preparations resulted in one single band. Except for the amino acid analyses, no evidence for a difference between the two phosphoprotein preparations could be found. After additional purification by iso-electric focusing the amino acid analyses demonstrated a similar composition. It is concluded that the two methods for phosphoprotein extraction yield the same product when purified properly. The study did not give any unequivocal answer as to if any phosphoprotein component exists in rat incisor dentin which is covalently linked to the collagen matrix.

Amino Acids↗
PubMed1980

Cation binding by the rat-incisor-dentine phosphoprotein. A spectroscopic investigation.

Nuclear magnetic resonance and electron paramagnetic resonance spectroscopy have been used to quantify metal binding to the phosphoprotein extractable from demineralized rat incisor dentine. Paramagnetic cation probes enable identification of the metal binding sites. Cations are able to diffuse across the protein surface while forming a relatively long-lived metal-phosphoprotein complex. The ability of the protein to sequester surface-mobile Ca(II) is discussed in terms of its ability to act as a possible nucleation site for the initial localization of Ca(II) within the dentine matrix.

Animals↗
PubMed1980

Reduction of tension in fearful dental patients.

A method based on the principles of desensitization, biofeedback, and control by patients is described; ten patients who had severe dental fear were given therapy before conventional treatment was begun.

Adult↗
PubMed1979

Separation of odontoblast Ca2+-ATPase and alkaline phosphatase.

Ca2+-ATPase activity was solubilized, partly purified, and separated from nonspecific alkaline phosphatase activity (APase1) of dentinogenically active rat incisor odontoblasts. Attempts were made to extract the enzymes by various agents, such as Triton X-100, deoxycholate, butanol, EDTA, and buffers of decreasing ionic strength. Solubilization by butanol followed by extraction with low concentrations of EDTA proved to be most effective. Purification and separation were done by molecular sieve chromatography. Ca2+-ATPase showed no activity against p-nitrophenyl phosphate (p-NPP) or inorganic pyrophosphate (PPi) and was unaffected by R 8231 [+/-)-6(m-bromophenyl)-5,6-dihydroimidazo(2,1-b)thiazole oxalate]. It was activated by Ca2+ and Mg2+ ions in equimolar concentrations with the substrate. The enzyme was rapidly inactivated in the solubilized state. An apparent molecular weight of about 18,000 was obtained from molecular sieve data. APase, showing activity against ATP, PPi, and p-NPP, was virtually totally inhibited by R 8231. It was activated by Mg2+ ions but slightly reduced in activity by Ca2+ ions. It had an apparent mol. wt. of 79,000. The results provide direct evidence for earlier suggestions of the existence in hard tissue forming cells of two phosphatases active at alkaline pH.

Alkaline Phosphatase↗
PubMed1979

Cathepsin D: ultra-immunohistochemical localization in dentinogenesis.

Cathepsin D was purified from rat liver using a new affinity chromatographic method, based on the coupling to the specific inhibitor pepstatin. This preparation was used for the production of specific antibodies from rabbit. The purified IgG fraction was conjugated to horseradish peroxidase in a two-step coupling procedure and used for electron microscopic immunohistochemistry of the odontoblast-predentine region of the rat incisor. Precipitates, indicating the presence of cathepsin D, were seen in the odontoblast, odontoblast process, and in the extracellular unmineralized matrix, the predentine. The observations are discussed in relation to proteoglycan degradation at the mineralization front simultaneous with crystal formation, and in relation to the function of lysosomal enzymes in the turnover of connective tissue.

Animals↗
PubMed1978

Isoelectric focusing of the phosphoprotein of rat-incisor dentin in ampholine and acid pH gradients. Evidence for carrier ampholyte-protein complexes.

Rat-incisor phosphoprotein (RIP) has been subjected to isoelectric focusing at 4 degrees in (a) an Ampholine pH gradient of 2.5-4 and (b) an acid pH gradient created by electrolysis of a system of acids and acidic ampholytes and covering the pH range 0.5-3.5. In the Ampholine gradient, the RIP unexpectedly formed several adjacent and strongly opalescent bands in the pH range 2.5-3.1. These bands, which migrated slowly toward the anode on prolonged focusing, are interpreted as being the result of an interaction between the amino groups of the Ampholine and the numerous phosphate groups of the protein. In the acid pH gradient, the RIP focused into one narrow zone corresponding to an isoelectric pH of 1.1 at 4 degrees. This value is consistent with the amino-acid composition and the phosphate content of the protein,

Animals↗