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E R Pietrzak

Publications and source records attributed to E R Pietrzak.

9 recordsLinked to original sources
PubMed1998

Characterization of serum antibodies to Porphyromonas gingivalis in individuals with and without periodontitis.

Although Porphyromonas gingivalis is a defined pathogen in periodontal disease, many subjects control the infection without experiencing loss of attachment. Differences in host susceptibility to the disease may be reflected in the pattern of humoral antibodies against specific P. gingivalis antigens. The aim of this study was to determine the presence of antibodies against immunodominant P. gingivalis antigens as well as the isotype and subclass of anti-P. gingivalis antibodies against outer membrane antigens in four groups of patients: P. gingivalis-positive, 1) with and 2) without periodontitis, and P. gingivalis-negative, 3) with and 4) without periodontitis. Antigens of molecular weight 92, 63, and 32 kDa and lipopolysaccharide were found to be immunodominant. Group 1 subjects showed a significantly higher response to the 92 and 63 kDa antigens compared with other groups. The response to lipopolysaccharide was significantly higher in group 1, and lower in group 4 than in groups 2, 3. Immunoglobulin G1 (IgG1), IgG2 and IgM antibodies against P. gingivalis outer membrane were present in all subjects, while only some subjects were seropositive for IgG3, IgG4 and IgA. There were no differences in concentrations for IgG1, IgG3 and IgM. The IgG2 concentration in group 4 was significantly higher than in groups 1 and 2, while the IgG4 concentration in group 4 was significantly lower than in other groups. The frequency of seropositivity for IgG4 and IgA was lowest in group 4, while IgG3 seropositivity was almost exclusively seen in healthy patients in groups 2, 4. These findings suggest that the presence of IgG3 may reflect non-susceptibility to the disease, while lack of IgG4 may be indicative of periodontal health and lack of infection.

Adult↗
PubMed1996

Expression of the E-selectin gene in human gingival epithelial tissue.

E-selectin is an adhesion molecule, expressed by cytokine-activated endothelial cells, that participates in the binding of neutrophils. Recent studies in our laboratory documented binding of the E-selectin-specific monoclonal antibody H4/18 to keratinocytes in inflamed human oral mucosa, particularly gingival epithelium. To determine whether this immunoreactivity was due to expression of authentic E-selectin, the presence of E-selectin mRNA in gingival epithelium was analysed using the polymerase chain reaction (PCR). Reverse transcription of epithelial RNA and amplification of cDNA with E-selectin-specific primers resulted in the formation of a 178 nucleotide PCR product identical to that obtained from cytokine-activated endothelial cells. Sequencing of the PCR product revealed 100% homology between epithelial and endothelial E-selectin fragments. Epithelial preparations did not contain mRNA for von Willebrand factor, excluding the possibility of contamination by endothelial cells. These results confirm immunohistochemical studies of E-selectin immunoreactivity in human oral mucosa and demonstrate that E-selectin expression is not confined to endothelium.

Adult↗
PubMed1996

Human gingival keratinocytes express E-selectin (CD62E).

OBJECTIVES: E-selectin (CD62E) is an adhesion molecule that participates in the binding of leukocytes to activated blood vascular endothelium. The present study was undertaken to characterise the pattern of E-selectin expression on epithelial cells of the gingival crevice and oral epithelium. METHODS: A panel of six anti-E-selectin monoclonal antibodies was reacted with cryosections of human gingiva and cytospins of cultured gingival keratinocytes. RESULTS: Three antibodies raised against leukocyte binding epitopes of the molecule (H4/18, H18/7, 1.2B6) were reactive with gingival keratinocytes, three were negative (4D10, BBA1, BBA2), while all six reacted with endothelial cells. Staining with H18/7 and 1.2B6 was weaker and more variable than with H4/18. In cell culture, levels of E-selectin expression reduced slowly, and were only modestly increased by treatment with exogenous TNF alpha, a known inducer of E-selectin on endothelium. CONCLUSIONS: E-selectin epitopes are expressed on gingival keratinocytes. These binding epitopes may be involved in the traffic of leukocytes in this tissue compartment.

Adult↗
PubMed1995

Differential reactivity of anti-E-selectin monoclonal antibodies in human gingival tissue.

E-selectin is a cytokine-inducible endothelial glycoprotein which participates in the binding of leukocytes to vascular endothelium. Variable levels of expression of E-selectin have been reported in gingivitis and periodontitis, and two differing concepts of its significance have emerged: either gingival blood vessels express E-selectin constitutively, or are continuously activated by inflammatory mediators arising from the gingival environment. A range of monoclonal antibodies reacting with different epitopes of E-selectin are available commercially. The present study explored the possibility that the choice of antibody could affect estimation of the level of expression of E-selectin in vivo. Five monoclonal antibodies were used to investigate E-selectin expression in serial cryosections of human gingival tissue. While E-selectin-positive vascular endothelial cells were detected with all antibodies, the number of positively staining endothelial cells varied, with BBA1 > H4/18 = H18/7 = 4D10 > 1.2B6. The frequency of strong staining in tissue specimens was BBA1 > 4D10 > H4/18 = H18/7 > 1.2B6, while the frequency of weak staining showed the reverse trend. Additionally, with antibodies H18/7 and 1.2B6, 17 and 36% of the specimens were E-selectin negative. The occurrence of what appear to be false positives and false negatives confounds estimation of the level of E-selectin expression. Based on these findings, patterns of endothelial E-selectin expression in gingivitis and periodontitis should be re-evaluated.

Adult↗
PubMed1995

Antibodies made against a formaldehyde-protein adduct cross react with an acetaldehyde-protein adduct. Implications for the origin of antibodies in human serum which recognize acetaldehyde-protein adducts.

Acetaldehyde, the major metabolite of ethanol, reacts with lysine and other free amino groups on proteins to form acetaldehyde-protein adducts. The presence of antibodies which recognize such acetaldehyde-protein adducts in sera from alcoholics has been attributed to an immune response to such adducts. Complicating this conclusion is the finding that sera from non-alcoholic control subjects also contain antibodies which recognize acetaldehyde-protein adducts. In the current research we sought to determine whether antibodies which recognize epitopes formed by the reaction of a protein with acetaldehyde can be formed in response to a protein modified with a structurally related protein adduct. We modified lysine residues on apolipoprotein (apo) B-100 with acetaldehyde and formaldehyde under reducing conditions, to form epsilon-N-methyl- and epsilon-N-ethyl-lysine residues, and with acetic anhydride to form epsilon-N-acetyl-lysine residues, and made antibodies against these modified proteins in guinea-pigs. In ELISA assays antibodies made against methylated apoB-100 (Me-apoB) cross-reacted effectively with ethylated apoB-100 (Et-apoB), while antibodies made against acetic anhydride-modified apoB-100 did not cross-react. We conclude that methyl-lysine shares one or more immunoreactive epitopes with ethyl-lysine, and that antibodies which recognize acetaldehyde-modified proteins can be formed in response to formaldehyde-modified proteins. We demonstrate that sera from both alcoholics and non-drinkers contain antibodies which recognize Me-apoB and Et-apoB and that the titres of these antibodies are comparable. These data raise the possibility that some human serum antibodies which recognize acetaldehyde-modified protein epitopes may have been made against formaldehyde-modified protein epitopes.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaldehyde↗
PubMed1990

Interaction of chronic ethanol consumption and aging on brain muscarinic cholinergic receptors.

It has been proposed that ethanol and aging may interact synergistically to impair brain function through effects on central muscarinic receptors. Previous studies have investigated the effect of either chronic ethanol treatment or aging, but not both factors simultaneously, on brain muscarinic receptors. We have studied brain muscarinic receptors in animals treated with ethanol for up to 25 months. Ethanol consumption for 3 and 9 months resulted in increased density of quinuclidinyl benzilate (QNB) binding sites in cortex, coinciding with an increase in high-affinity pirenzepine binding sites and low-affinity carbachol binding sites. Upregulation of QNB binding sites in striatum and hippocampus became obvious after further ethanol treatment (15 and 21 months, respectively). Affinity of QNB binding sites and carbachol binding sites was not altered by ethanol treatment. However, there was an ethanol-related decrease in affinity of low-affinity pirenzepine binding sites in cerebral cortex. Density of QNB binding sites and low-affinity pirenzepine binding sites decreased with age in three brain areas investigated. There were age-related changes in receptor affinity in hippocampus and striatum, but not in cortex. Ethanol-related upregulation of muscarinic receptors was superimposed on age-related loss of receptors. We conclude that acceleration of the aging process associated with ethanol abuse is unlikely to be explained on the basis of alterations in receptor density or affinity.

Aging↗
PubMed1989

Plasticity of brain muscarinic receptors in aging rats: the adaptative response to scopolamine and ethanol treatment.

Young and aged rats were treated chronically with ethanol or scopolamine. Muscarinic receptors were measured in cerebral cortex, hippocampus and striatum. Following scopolamine treatment muscarinic receptor density in cerebral cortex, hippocampus and striatum of young rats increased by 34, 57 and 27%, respectively; in brains of aged rats the increase was 41% in cerebral cortex, 43% in hippocampus and nil in striatum. Affinity of muscarinic receptors was not changed by scopolamine treatment. Following chronic ethanol administration there was a 48% increase in cortical muscarinic receptor density in young, but not aged rats. The density of muscarinic receptors in hippocampus and striatum of both young and aged rats was not affected by ethanol treatment. Affinity of receptors in hippocampus of aged, ethanol-treated rats was increased compared to age-matched controls. Adaptative responses of the muscarinic receptor/transducer system to neurotransmitter availability are present in both young and aged rats, both the ethanol-induced response is present only in young animals. This suggests differences in the mechanism of action of ethanol and receptor agonists and antagonists in modulating receptor plasticity.

Aging↗
PubMed1989

A feeding regime for the study of the interaction of ethanol and aging.

A suitable model for the study of the interaction of the aging process and prolonged treatment with ethanol is described. Animals were given 15% ethanol in the drinking water for up to 25 months. There was little disruption in the growth of the animals. Ethanol treatment resulted in a number of neurological and morphological changes some of which persisted throughout the treatment period. Both young and old animals displayed metabolic tolerance by the criteria of resistance to ethanol-induced hypothermia and increased metabolism of [14C]ethanol. The regime used has proved useful in the study of the interaction of ethanol and aging in the rat.

Aging↗