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PubMed1987

Effect of basement membrane entactin on epidermal cell attachment and growth.

A preparation of laminin and entactin (Matrix), extracted from the basement membrane of the murine cell line M1536-B3 was used to evaluate the effect of entactin on epidermal cell attachment and growth in culture. Cell growth on Matrix was significantly higher than on laminin or plastic, in the presence or absence of serum. In attachment assays, the attachment of cells to laminin (137% of control) or to Matrix (158% of control) was significantly higher when compared with plastic (p less than 0.01), and the attachment to Matrix was higher than to laminin (p less than 0.05). Varying the amount of laminin or Matrix used as a substratum showed each enhanced cell attachment to the same maximum value (approximately 50% attached cells or 160% of control), but maximal attachment was achieved with lower amounts of Matrix (15 micrograms Matrix vs 15-30 micrograms laminin, p less than 0.05). Inhibition studies with anti-entactin and anti-laminin antibodies were used to assay the specific contribution of entactin to cell attachment to Matrix. Pretreatment of the substratum with increasing amounts of anti-entactin antibody decreased cell attachment to Matrix in a concentration-dependent manner, with cell attachment to Matrix eventually falling to the same level as that obtained with laminin. There was no effect with anti-entactin on cell attachment to laminin or to plastic controls, and nonspecific rabbit IgG had no effect on any group. Similar experiments were performed using 2 different concentrations of anti-laminin antibody. At a low concentration, anti-laminin antibody decreased attachment to laminin (to a level equivalent to the plastic control). At a higher concentration anti-laminin decreased attachment to Matrix, but to a level that was still greater than the plastic control. The anti-laminin antibody had no effect on attachment to the plastic control and nonspecific rat IgG in equivalent amounts had no effect on attachment to any of the substrata. These results indicate that Matrix, containing laminin and entactin, enhanced cell attachment above the level seen with laminin alone, and that this effect was probably due to the presence of entactin in the Matrix.

Animals↗

PubMed1982

Attachment of Paramecium to polystyrene surfaces: a model system for the analysis of sexual cell recognition and nuclear activation.

In the ciliate Paramecium caudatum, only mating-reactive cells can attach to the polystyrene surface of Petri dishes. The attachment of mating-reactive cells occurs exclusively at the tips of ventrally located cilia (mating-reactive cilia) and appears to involve a hydrophobic interaction. An increase in the hydrophilic nature of the polystyrene surface following treatment with sulphuric acid results in the loss of attachment of reactive cells. The presence or absence of Ca ions and varying the ionic strength of the medium have no effect upon attachment. Although attachment reactivity is closely correlated with mating reactivity, the attachment sites appear distinct from the mating recognition sites, as suggested by the following experimental results: (I) cells that lose mating reactivity following treatment with trypsin are still able to attach to the polystyrene surface; (2) the attachment of cells appears temperature-dependent over a range where mating reactivity remains uneffected; (3) mating reactivity is quickly lost as a result of attachment to the surface of the dish. While the mechanism of attachment is not the same as sexual recognition, the attachment to the polystyrene surface initiates the early stages of the conjugation process. Cells that attach show micronuclear migration while unattached cells do not. The maximum rate of micronuclear migration occurs approximately 30 min after attachment. Meiosis does not occur following migration in the attached cells as in cells that are sexually mating. The relationship between the mating substance and the attachment substance is discussed, while the utilization of the attachment phenomenon for other experimental procedures is proposed.

Animals↗

PubMedDate not supplied

Attachment theory: a model for health care utilization and somatization.

OBJECTIVE: Attachment theory proposes that cognitive schemas based on earlier repeated experiences with caregivers influence how individuals perceive and act within interpersonal relationships. We hypothesized that medical patients with two types of insecure attachment-preoccupied and fearful attachment-would have higher physical symptom reporting compared with those with other attachment styles, but that preoccupied attachment would be associated with higher and fearful attachment with lower primary care utilization and costs. METHODS: In a large sample of adult female primary care health maintenance organization patients (N = 701), we used analysis of covariance and Poisson regressions to determine whether attachment style was significantly associated with 1) symptom reporting based on questions from the somatization section of the Diagnostic Interview Schedule and 2) contemporaneous automated utilization and cost data. RESULTS: Attachment style was significantly associated with symptom reporting (p =.02), with patients with preoccupied (p =.03) and fearful (p =.003) attachment having a significantly greater number of physical symptoms compared with secure patients. There were no significant differences in medical comorbidity between attachment groups. Attachment was also significantly associated with primary care visits and costs. Patients with preoccupied attachment had the highest primary care costs and utilization, whereas patients with fearful attachment had the lowest. CONCLUSIONS: These results suggest that attachment style is an important factor in assessing symptom perception and health care utilization. Despite being on opposite ends of the utilization spectrum, patients with preoccupied and fearful attachment have the highest symptom reporting. These data challenge the observation that increased symptom reporting is uniformly associated with increased utilization in medical patients.

Adult↗

PubMed1999

[Transmission of binding over generations--contribution of the Adult Attachment Interview].

A new domain has been established within attachment research that deals with mental representations of attachment in adults, particularly in parents. This contribution describes the procedure of the Adult Attachment Interview (AAI) developed by George et al. (1996) and the scoring and classification system by Main and Goldwyn (1994). This method allow trained coders a reliable classification of different states of mind with respect to attachment based on a content and discourse analysis of the interview transcripts. By means of observational procedure of the Strange Situation for infants and the AAI for the adults, several studies support the assumption of a transmission of attachment relationships from one generation to the next one. These findings reveal that parents with secure autonomous attachment representations predominantly have infants with secure attachment patterns, parents with insecure-dismissing attachment representations mostly have children with an avoidant attachment and parents with insecure-preoccupied representations often have children with an insecure-ambivalent attachment. Less consistent results have been found for the correspondence between parents unresolved attachment status with respect to traumatic experiences and their infants' disoriented/disorganized attachment patterns. A recent study assessing attachment in six year olds revealed as well the transmission from mothers' attachment representations to those of their children for this older age. Since many studies have confirmed the correspondence of parents' and infants' attachment classifications, research interests are now directed towards the mediating processes of transmission.

Adult↗

PubMed2001

[Surface stress analysis of distal extension removable partial denture retained with two types of semi-precision attachments].

OBJECTIVE: The aims of this study are to analyze the surface stress of the periodontal supporting bone of the bilateral distol extension removable partial denture which is retained by using intra-coronal or extra-coronal semi-precision attachment, and to characterize the biomechanics of these two designs by using a strain gauge. METHODS: A fresh human mandible specimen with 76|67 missing and six bilateral partial removable denture retained with six semi-precision attachments were made, including three attachments with intra-coronal studs and three attachments with extra-coronal vertical bars. A total of six 45 degrees rosette strain gauges were bonded at six prepared points on the surface of the mandible to measure the surface stress, including the middle point between 76 of the buccal edentulous alveolar crest area under the denture base verge(point 1), the distal buccal cervix of 5 (point 2), the buccal apical area of 5 (point 3), the buccal middle area of 34 roots (point 4, 5), the lingual middle area of 5 root (point 6). The static loads of 14N, 28N and 42N were applied vertically, buccally 45 degrees, lingually 45 degrees at the middle point of the 6|6 occlusal surface. The micro-strain was recorded, and the maximal/minimal principle stresses were calculated for each RPD and each point. The stress characteristics of these two types of attachments were compared and analyzed. RESULTS: In most situations, the stress of these two semi-precision attachments showed significant differences. The vertical load: The stress values of these intra-coronal and extra-coronal attachments at points 1, 2, 3, 4, 6 differed significantly(P < 0.05), including points 1, 2, (sigma intra < sigma extra) and points 3, 4, 6(sigma intra > sigma extra). Buccal loads: The stress values of these intra-coronal and extra-coronal attachments at points 1, 2, 3, 4, 5 differed significantly(P < 0.05), including points 1, 2(sigma intra < sigma extra) and points 3, 4, 5(sigma intra > sigma extra). Lingual loads: The stress values of these intra-coronal and extra-coronal attachments at points 2, 3, 4, 6 differed significantly (P < 0.05, sigma intra > sigma extra). The intra-coronal attachment generally produced higher stress at the site of the alveolar bone around the abutment than the extra-coronal attachment, but extra-coronal attachment produced higher stress at the edentulous alveolar crest and the distal cervical alveolar bone of the distal abutment than the intra-coronal attachment. CONCLUSION: The intra-coronal attachment is suggested to be applied in some cases that the periodontal condition of distal abutment was good, and the extra-coronal attachment is suggested to be used in some cases that the condition of the edentulous alveolar crest is fairly good, while the periodontal condition of the distal abutment was relatively weak.

Adult↗

PubMed1981

Attachment factors amont enterotoxigenic Escherichia coli from patients with acute diarrhea from diverse geographic areas.

To cause diarrhea, enterotoxigenic Escherichia coli (ETEC) must initially colonize the small bowel. Different surface structures have been implicated in this initial attachment. Recognized attachment factors include colonization factor antigens I and II (CFA/I and CFA/II) and type I pili. Several methods of detection for each of these factors have been reported. In this study, we screened for the presence of these attachment factors among enterotoxigenic E. coli isolated from 40 patients with acute diarrhea and 40 asymptomatic control individuals and examined their ability to attach to ATCC 407 human intestinal cells in vitro. Of 40 patients with diarrhea, 16 (40%) had enterotoxigenic E. coli isolates which exhibited an attachment trait. Fourteen (35%) of these isolates demonstrated the ability to attach to ATCC 407 cells, whereas only four isolates from asymptomatic controls attached (P < 0.02). A total of 20% of the patient isolates and 7.5% of the control isolates possessed CFA/I. Only one patient isolate demonstrated CFA/II. Evidence for type I pili was found on 10% of the patient isolates and 12.5% of the control isolates. Attachment to ATCC 407 cells allowed the detection of 87.5% (14 of 16) of enterotoxigenic E. coli isolates with any type of attachment trait. Of the 14 cases demonstrating attachment ability to ATCC 407 cells, 7 did not attach in the presence of mannose. Three of these showed evidence for both CFA/I and type I pili, one showed only CFA/I, and one showed only type I pili. Two of those mannose-sensitive attaching isolates showed no other demonstrable trait. Seven patient isolates showed mannose-resistant attachment. Of these, two were classified as possessing CFA/I, and one was classified as possessing CFA/II. The four remaining isolates could not be classified into any recognized attachment factor category, suggesting that other attachment factors remain to be identified.

Antigens, Bacterial↗

PubMed1997

Reciprocal signaling between Drosophila epidermal muscle attachment cells and their corresponding muscles.

Directed intercellular interactions between distinct cell types underlie the basis for organogenesis during embryonic development. This paper focuses on the establishment of the final somatic muscle pattern in Drosophila, and on the possible cross-talk between the myotubes and the epidermal muscle attachment cells, occurring while both cell types undergo distinct developmental programs. Our findings suggest that the stripe gene is necessary and sufficient to initiate the developmental program of epidermal muscle attachment cells. In stripe mutant embryos, these cells do not differentiate correctly. Ectopic expression of Stripe in various epidermal cells transforms these cells into muscle-attachment cells expressing an array of epidermal muscle attachment cell-specific markers. Moreover, these ectopic epidermal muscle attachment cells are capable of attracting somatic myotubes from a limited distance, providing that the myotube has not yet been attached to or been influenced by a closer wild-type attachment cell. Analysis of the relationships between muscle binding and differentiation of the epidermal muscle attachment cell was performed in mutant embryos in which loss of muscles, or ectopic muscles were induced. This analysis indicated that, although the initial expression of epidermal muscle-attachment cell-specific genes including stripe and groovin is muscle independent, their continuous expression is maintained only in epidermal muscle attachment cells that are connected to muscles. These results suggest that the binding of a somatic muscle to an epidermal muscle attachment cell triggers a signal affecting gene expression in the attachment cell. Taken together, our results suggest the presence of a reciprocal signaling mechanism between the approaching muscles and the epidermal muscle attachment cells. First the epidermal muscle attachment cells signal the myotubes and induce myotube attraction and adhesion to their target cells. Following this binding, the muscle cells send a reciprocal signal to the epidermal muscle attachment cells inducing their terminal differentiation into tendon-like cells.

Animals↗

PubMed2003

A picture is worth a thousand words: children's representations of family as indicators of early attachment.

To ascertain whether attachment representations at age 7 are related to early attachment behaviour, family drawings of 123 7-year-olds of known infant attachment status (25 avoidant, 80 secure, 18 resistant) were scored in four ways. Three of these were based in previous attachment research and one was based on a clinical method. The attachment-based coding schemes included specific markers for each attachment pattern (Kaplan & Main, 1985), global ratings (Fury, Carlson, & Sroufe, 1997) and efforts to classify each drawing as belonging to one of the three primary infant attachment groups (secure, avoidant, resistant). In the clinical scheme, children who had been resistant infants were distinguished from the others by use of overlapping and encapsulated figures. For the attachment based schemes, although individual markers were not successful in discriminating attachment groups, the more global approaches (aggregation of markers, global rating scales and judgments of attachment classification) succeeded in this task. In regression analyses controlling for concurrent child and parent measures, infant attachment did not make a significant contribution to predicting insecurity markers in drawings, although child current emotional functioning did. These findings linking attachment relationships with later representations of family relationships were in accord with the conception that avoidant attachment strategies de-emphasize intimate relationships, while resistant attachment strategies are preoccupied with close relationships. These links are most evident in global interpretive strategies rather than those that rely on specific markers.

Art↗

PubMed1991

Clinical risk indicators for periodontal attachment loss.

The purpose of the present investigation was to evaluate the association of baseline clinical parameters of periodontal disease with disease progression in the following year. 271 randomly selected subjects from Ushiku Japan were monitored for overt gingivitis and plaque accumulation at 4 sites per tooth and probing pocket depth, probing attachment level and bleeding on probing at 6 sites per tooth for all teeth at baseline and 1 year. A subject was considered to exhibit additional attachment loss if one or more sites increased 3 mm or more in a probing attachment level measurement in one year. The clinical variables included age, sex, number of missing teeth, mean pocket depth and attachment level. In addition, the % of sites which exhibited overt gingivitis, visible plaque, pocket depths, attachment levels or gingival recession over certain mm thresholds or bled on probing were determined. Chi 2 analysis was used to seek significant associations between the baseline clinical variables and subsequent attachment loss in a subject. Only 74 of the 271 subjects (27.3%) exhibited additional attachment loss of 3 mm or more at 1 or more sites after 1 year. Older subjects had a greater risk of disease progression than younger subjects. There were no significant differences in % of individuals exhibiting additional attachment loss when divided on the basis of sex, number of missing teeth or % of sites with overt gingivitis. However, the greater the % of sites with visible plaque or which bled on probing, the greater was the likelihood of subsequent attachment loss. Increasing mean levels of pocket depth or attachment level or increasing %s of sites exhibiting prior attachment loss were strongly related to the proportion of individuals with subsequent attachment loss. Gingival recession exhibited similar but weaker relationships. Log-linear analysis suggested that the association between bleeding on probing, age, or plaque levels with additional attachment loss may be explained by the association of these variables with baseline attachment loss. The analyses were repeated with a positive subject defined as having only 1 active site or 2 or more active sites. 37 subjects fit the 1st criterion and the remaining 37 the 2nd criterion. The associations observed were almost identical to those found when subjects were considered positive on the basis of 1 or more changing sites. Discriminant analysis was used to classify subjects as active or inactive using up to 11 predictor variables.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed2004

[Measurements of the flux densities of static magnetic fields generated by two types of dental magnetic attachments and their retentive forces].

OBJECTIVE: To measure and analyze the flux densities of static magnetic fields generated by two types of commonly used dental magnetic attachments and their retentive forces, and to provide guidance for the clinical application of magnetic attachments. METHODS: A digital Gaussmeter was used to measure the flux densities of static magnetic fields generated by two types of magnetic attachments, under four circumstances: open-field circuit; closed-field circuit; keeper and magnet slid laterally for a certain distance; and existence of air gap between keeper and magnet. The retentive forces of the magnetic attachments in standard closed-field circuit, with the keeper and magnet sliding laterally for a certain distance or with a certain air gap between keeper and magnet were measured by a tensile testing machine. RESULTS: There were flux leakages under both the open-field circuit and closed-field circuit of the two types of magnetic attachments. The flux densities on the surfaces of MAGNEDISC 800 (MD800) and MAGFIT EX600W (EX600) magnetic attachments under open-field circuit were 275.0 mT and 147.0 mT respectively. The flux leakages under closed-field circuit were smaller than those under open-field circuit. The respective flux densities on the surfaces of MD800 and EX600 magnetic attachments decreased to 11.4 mT and 4.5 mT under closed-field circuit. The flux density around the magnetic attachment decreased as the distance from the surface of the attachment increased. When keeper and magnet slid laterally for a certain distance or when air gap existed between keeper and magnet, the flux leakage increased in comparison with that under closed-field circuit. Under the standard closed-field circuit, the two types of magnetic attachments achieved the largest retentive forces. The retentive forces of MD800 and EX600 magnetic attachments under the standard closed-field circuit were 6.20 N and 4.80 N respectively. The retentive forces decreased with the sliding distance or with the increase of air gap between keeper and magnet. CONCLUSION: The magnetic attachments have flux leakages. When they are used in patients' oral cavities, if keeper and magnet are not attached accurately, the flux leakage will increase, and at the same time the retentive force will decrease. Therefore the keeper and magnet should be attached accurately in clinical application.

Denture Precision Attachment↗

PubMed2003

Retention and postinsertion maintenance of bar-clip, ball and magnet attachments in mandibular implant overdenture treatment: an in vivo comparison after 3 months of function.

It could be hypothesised that attachments, which provide more retention against vertical and horizontal dislodgement, will be associated with more favourable parameters of oral function. This in vivo study is designed to provide data regarding initial retention force, loss of retention force after 3 months of function and postinsertion maintenance and complications associated with the use of magnet, bar-clip and ball attachments in mandibular overdenture treatment. Eighteen edentulous subjects received two permucosal implants in the inter-foramina region of the mandible, a new denture and three successive suprastructure modalities (magnet-, bar-clip and ball attachments). The retention force of the attachments at baseline and after 3 months was measured in a standardised way. The amount and type of postinsertion maintenance that was related to the attachment were evaluated. No differences in retention force at baseline and after 3 months of loading were observed for all three attachment types. The mean retention forces of magnet attachments, bar-clip attachments and ball attachments were 8.1, 31.3 and 29.7 N respectively. Functional maintenance complications related to the attachments were predominantly observed in 11/36 magnet attachments. Functional problems in the ball attachment group were relatively rare, easily manageable and seen in 4/36 attachments. The bar-clip attachments exhibited no maintenance problems at all.

Adult↗

PubMed1987

Platelet thrombospondin mediates attachment and spreading of human melanoma cells.

Human platelet thrombospondin adsorbed on plastic promotes attachment and spreading of human G361 melanoma cells. Attachment is rapid, and spreading is maximal by 90 min with 60-90% of the attached cells spread. In contrast, thrombospondin promotes attachment but not spreading of human C32 melanoma cells, which attach and spread only on laminin substrates. The specificity of these interactions and the regions of the thrombospondin molecule involved in attachment and spreading were examined using proteolytic fragments of thrombospondin and by inhibition studies. The sulfated fucan, fucoidan, and monoclonal antibody A2.5, which is directed against the heparin-binding domain of thrombospondin, selectively inhibit spreading but only weakly inhibit attachment. Monoclonal antibodies against some other domains of thrombospondin, however, are potent inhibitors of attachment. The amino-terminal heparin-binding domain of thrombospondin does not promote attachment. Large fragments lacking the heparin-binding domain support attachment but not spreading of G361 cells. Attachment activity is lost following removal of the 18-kD carboxyl-terminal domain. These results suggest that at least two melanoma ligands are involved in cell attachment and spreading on thrombospondin. The carboxyl-terminal region and perhaps other regions of the molecule bind to receptor(s) on the melanoma surface that promote initial attachment but not cell spreading. Interaction of the heparin-binding domain with sulfated glycoconjugates on melanoma surface proteoglycans and/or sulfated glycolipids mediates spreading. Monoclonal antibodies A2.5 and C6.7 also reverse spreading of G361 cells growing on glass culture substrates, suggesting that binding to thrombospondin mediates attachment of these melanoma cells in culture.

Adsorption↗

PubMed1991

Multiple cell surface receptors for the short arms of laminin: alpha 1 beta 1 integrin and RGD-dependent proteins mediate cell attachment only to domains III in murine tumor laminin.

Cell surface molecules that interact with the cross formed by the three short arms of murine tumor laminin were studied using thermal perturbation, antibody and peptide blocking, and affinity chromatography. Several potential receptors for the laminin short arms were revealed that differed from those mediating cell attachment to the E8 (long arm) fragment. Two cell lines, Rugli and L8 attached well to E1-X (short arm) fragments of laminin. This attachment was blocked by antibodies against alpha 1 integrin chains. Other cells were unable to attach strongly to E1-X, but attached to P1. This attachment was unaffected by anti-beta 1 integrin antibodies, but specifically blocked by the peptide GRGDS. By contrast, binding of Rugli cells was RGD independent and blocked by anti-beta 1 integrin antibodies. G7 and C2C12 myoblasts were very sensitive to GRGDS (ID50 approximately 2 micrograms.ml-1) for attachment to P1 which implied that a non-beta 1 series integrin, possibly alpha v beta 3, was involved. On heat denaturation of P1(3) attachment remained sensitive to RGDS and ID50 was unchanged. On heat denaturation of E1-X, attachment remained sensitive to RGDS but the ID50 increased to approximately 200 micrograms.ml-1. Cellular beta 1 integrins were retained on laminin affinity columns. A beta 1 integrin with an approximately 190 kD alpha-chain could be isolated from Rugli cells whose attachment could be blocked by anti-alpha 1 antibodies and not from cells blocked by RGDS peptides. Anti-alpha 1 antibodies blocked Rugli attachment to native laminin, but only when the E8 cell binding sites on laminin were also blocked. Thus, a receptor related to alpha 1 beta 1 integrin can function simultaneously with a receptor for E8. Anti-alpha 1 also blocked attachment to heated laminin, suggesting that the heat-stable attachment activity in laminin involved the E1-X binding site. Thus, at least two putative receptors mediate attachment to the short arms of laminin. One, related to alpha 1 beta 1 integrin, recognizes RGDS-independent sites in E1-X defined by P1 (within domains III, IIIa, IIIb), and one is an RGD-dependent molecule recognizing sites in P1, and is not a beta 1 integrin.

Amino Acid Sequence↗

PubMed2005

Spatial periodicity of Escherichia coli K-12 biofilm microstructure initiates during a reversible, polar attachment phase of development and requires the polysaccharide adhesin PGA.

Using fast Fourier transform (FFT) analysis, we previously observed that cells within Escherichia coli biofilm are organized in nonrandom or periodic spatial patterns. Here, we developed a gravity displacement assay for examining cell adherence and used it to quantitatively monitor the formation of two distinct forms of cell attachment, temporary and permanent, during early biofilm development. Temporarily attached cells were mainly surface associated by a cell pole; permanent attachments were via the lateral cell surface. While temporary attachment precedes permanent attachment, both forms can coexist in a population. Exposure of attached cells to gravity liberated an unattached population capable of rapidly reassembling a new monolayer, composed of temporarily attached cells, and possessing periodicity. A csrA mutant, which forms biofilm more vigorously than its wild-type parent, exhibited an increased proportion of permanently attached cells and a form of attachment that was not apparent in the parent strain, permanent polar attachment. Nevertheless, it formed periodic attachment patterns. In contrast, biofilm mutants with altered lipopolysaccharide synthesis (waaG) exhibited increased cell-cell interactions, bypassed the polar attachment step, and produced FFT spectra characteristic of aperiodic cell distribution. Mutants lacking the polysaccharide adhesin beta-1,6-N-acetyl-d-glucosamine (DeltapgaC) also exhibited aperiodic cell distribution, but without apparent cell-cell interactions, and were defective in forming permanent attachments. Thus, spatial periodicity of biofilm microstructure is genetically determined and evident during the formation of temporary cell surface attachments.

Adhesins, Bacterial↗

PubMed1995

Role of the heparin binding domain of fibronectin in attachment and spreading of human bone-derived cells.

Human bone-derived cells are known to attach and spread on surfaces which have been precoated with fibronectin, but the contributions made by specific domains of the molecule have not yet been defined. Here we refer to the osteoblast-like cells as human bone cells. We have determined the relevance of separate regions of fibronectin, particularly the heparin-binding region, for the initial attachment and spreading of these cells. Human bone cells attached to fragments from each of the cell- and heparin-binding regions of fibronectin, but failed to attach to a fragment from the gelatin-binding region. Bovine corneal epithelial cells, which were included as an example of an alternative primary cell strain, attached to the cell-binding fragment but showed no specific short-term attachment to the heparin or gelatin-binding fragments. Monoclonal antibody MAb17, which binds to the cell binding region of fibronectin, partially inhibited the attachment of both human bone cells and corneal epithelial cells to intact fibronectin when present at 50 micrograms/ml and reduced human bone cell attachment to the cell-binding region fragment of fibronectin. Monoclonal antibody, MAb 32, which binds to the heparin-binding region of fibronectin, failed to inhibit attachment of the human bone cells to fibronectin but reduced the attachment of these cells to the heparin-binding region fragment. Heparin and chondroitin sulphate were able to inhibit human bone cell attachment to the heparin-binding fragment of fibronectin but had no effect on their attachment to intact fibronectin or the cell-binding region of fibronectin. Immunofluorescent staining and confocal microscopy showed extensive spreading and actin filament formation when human bone cells were cultured on intact fibronectin. Cells cultured on the heparin-binding fragment showed only minimal spreading coinciding with less extensive actin filament organisation. On the cell-binding fragment of fibronectin more spreading was seen than on the heparin-binding fragment but it was not as extensive as on intact fibronectin. Taken together, these data suggest that human bone cells, unlike bovine corneal epithelial cells, have an attachment mechanism for the heparin-binding region of fibronectin. Attachment to this region is probably mediated by cell surface proteoglycans. However, interaction with the cell-binding domain is required for effective cell spreading of human bone cells on fibronectin during the first 90 minutes after seeding into culture.

Actin Cytoskeleton↗

PubMed1997

Differential attachment of oral treponemes to monolayers of epithelial cells.

This in vitro study describes the attachment properties of several oral treponemes to monolayers of epithelial cells and the effect of epithelial cell confluence on treponeme attachment. Four serotypes of Treponema denticola, Treponema scoliodontum, three subspecies of Treponema socranskii, and Treponema vincentii were tested with monolayers of epithelial cells of human and canine origin. Attachment of oral treponemes were compared to attachment by T. pallidum subsp. pallidum, and by the non-pathogen Treponema phagedenis. Results indicated that different serotypes of T. denticola had similar abilities to attach to epithelial cells. However, subspecies of T. socranskii differed in their ability to attach to epithelial cells. The proportion of epithelial cells susceptible to attachment by oral spirochetes was strongly related to the confluence level of the monolayer. In contrast, T. pallidum attached equally well to both epithelial cell lines at all confluence levels. T. phagedenis attached to < 1% of all epithelial cells. In general, attachment of oral treponemes to canine cells was lower than to human cells, suggesting species-specificity for adherence. Attachment of oral treponemes to epithelial cells may promote colonization of the periodontal pocket, as well as retention of treponeme colonies within plaque. The preference of oral treponemes to attach to cells of low confluence fields may translate in vivo to an increased ability to attach to cells which are actively dividing. Such cells are found in areas of repair, a common status within inflamed periodontal pockets. Furthermore, attachment of oral treponemes to epithelial cell barriers may promote or potentiate cytopathic processes.

Animals↗

PubMed2001

Relationship of cigarette smoking to attachment level profiles.

OBJECTIVES: The present investigation examined clinical features of periodontal disease and patterns of attachment loss in adult periodontitis subjects who were current, past or never smokers. MATERIAL AND METHODS: 289 adult periodontitis subjects ranging in age from 20-86 years with at least 20 teeth and at least 4 sites with pocket depth and/or attachment level >4 mm were recruited. Smoking history was obtained using a questionnaire. Measures of plaque accumulation, overt gingivitis, bleeding on probing, suppuration, probing pocket depth and probing attachment level were taken at 6 sites per tooth at all teeth excluding 3rd molars at a baseline visit. Subjects were subset according to smoking history into never, past and current smokers and for certain analyses into age categories <41, 41-49, >49. Uni- and multi-variate analyses examined associations between smoking category, age and clinical parameters. RESULTS: Current smokers had significantly more attachment loss, missing teeth, deeper pockets and fewer sites exhibiting bleeding on probing than past or never smokers. Current smokers had greater attachment loss than past or never smokers whether the subjects had mild, moderate or severe initial attachment loss. Increasing age and smoking status were independently significantly related to mean attachment level and the effect of these parameters was additive. Mean attachment level in non smokers <41 years and current smokers >49 years was 2.49 and 4.10 mm respectively. Stepwise multiple linear regression indicated that age, pack years and being a current smoker were strongly associated with mean attachment level. Full mouth attachment level profiles indicated that smokers had more attachment loss than never smokers particularly at maxillary lingual sites and at lower anterior teeth. CONCLUSIONS: In accord with other studies, smokers had evidence of more severe periodontal disease than past or never smokers. At all levels of mean attachment loss, smokers exhibited more disease than never smokers. Difference in mean attachment level between smokers and never smokers at individual sites was not uniform. Significantly more loss was observed at maxillary lingual sites and lower anterior teeth suggesting the possibility of a local effect of cigarette smoking.

Adult↗

PubMed1997

Adult attachment processes: individual and couple perspectives.

This paper overviews a new approach to understanding the range of difficulties experienced in close attachment relationships in adulthood. Drawing on the work of Bowlby, four prototypic adult attachment patterns are defined in terms of the intersection of two underlying dimensions, the positivity of the person's self-image and the positivity of the person's image of others (Bartholomew, 1990; Bartholomew & Horowitz, 1991). The distinct interpersonal difficulties associated with each attachment pattern are described. Findings are presented indicating that individual differences in attachment have implications for the quality of adults' romantic relationships, and that attachment theory may be helpful in understanding violent spousal relationships. Five current issues in the study of adult attachment are addressed: the stability of attachment patterns, the associations between attachment and general personality factors, the relative merits of categorical and prototype assessments of attachment, the identification of multiple attachments in adulthood, and the specificity of adult attachment patterns. It is suggested that the four-category model of adult attachment is especially sensitive to the range and complexity of attachment-related difficulties experienced in adulthood.

Adult↗