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PubMed2005

The relationship of adult attachment to emotion, catastrophizing, control, threshold and tolerance, in experimentally-induced pain.

Although insecure attachment has been associated with a range of variables linked with problematic adjustment to chronic pain, the causal direction of these relationships remains unclear. Adult attachment style is, theoretically, developmentally antecedent to cognitions, emotions and behaviours (and might therefore be expected to contribute to maladjustment). It can also be argued, however, that the experience of chronic pain increases attachment insecurity. This project examined this issue by determining associations between adult attachment characteristics, collected prior to an acute (coldpressor) pain experience, and a range of emotional, cognitive, pain tolerance, intensity and threshold variables collected during and after the coldpressor task. A convenience sample of 58 participants with no history of chronic pain was recruited. Results demonstrated that attachment anxiety was associated with lower pain thresholds; more stress, depression, and catastrophizing; diminished perceptions of control over pain; and diminished ability to decrease pain. Conversely, secure attachment was linked with lower levels of depression and catastrophizing, and more control over pain. Of particular interest were findings that attachment style moderated the effects of pain intensity on the tendency to catastrophize, such that insecurely attached individuals were more likely to catastrophize when reporting high pain intensity. This is the first study to link attachment with perceptions of pain in a pain-free sample. These findings cast anxious attachment as a vulnerability factor for chronic pain following acute episodes of pain, while secure attachment may provide more resilience.

Acute Disease↗

PubMed1997

Specificity of attachment and neurite outgrowth of dissociated basal forebrain cholinergic neurons seeded on to organotypic slice cultures of forebrain.

Development and differentiation of basal forebrain-derived cholinergic neurons were studied using a new technique that combines dissociated cell cultures with organotypic slice cultures. Slices of cerebral cortex or entire forebrain hemispheres were taken from early postnatal rat pups and maintained as organotypic cultures on membranes. Dissociated cell suspensions of basal forebrain tissue, taken from rat or mouse fetuses at gestational day 15-17, were seeded on to the slice cultures. Combined cultures were maintained for two to 14 days in vitro. Cultures processed for acetylcholinesterase histochemical staining demonstrated that stained neurons display regional variation in attachment to the slice, with most attachment occurring on cortex and with no detectable attachment on the caudate-putamen. Regional differences in attachment occur between cortical areas, with medial (cingulate) cortex showing much denser cell attachment than lateral (parietal) cortex, and across cortical layers, with layer I and deep layers showing more attachment than middle cortical layers. Similar patterns were observed on slices from rat brain irrespective of whether rat or mouse dissociated cells were used. Tyrosine hydroxylase-stained dissociated cells from ventral midbrain displayed a different pattern of attachment, with prominent attachment to the caudate putamen and less apparent specificity of regional and cortical laminar attachment. Little evidence of neurite outgrowth occurred during the first two days in vitro, but by four days, acetylcholinesterase-positive basal forebrain cells displayed several short and thick neurites that appeared to be dendrites, and one long process that appeared to be an axon. By seven days in vitro, dendrites are well developed and the presumed axon has extended branches over wide areas of cortex. These studies revealed several different types of cell-tissue interaction. The degree of cell growth and differentiation ranged from robust growth when dissociated cells were seeded on to slice cultures of normal target tissue, to apparently no attachment or growth when cells were seeded on to non-target tissue. This combined technique appears to be a useful method for studies of specificity of cell attachment and patterns of neurite outgrowth.

Acetylcholinesterase↗

PubMed1992

The attachments of chromatin loops to the nucleoskeleton.

It is widely assumed by cell biologists that chromatin is looped by attachment to some nuclear skeleton. 'Structural' attachments might be mediated through specific sequences; these would be attached in most cells in an organism, underlying the basic structure of the mitotic chromosome and persisting throughout interphase. 'Functional' attachments might also exist, perhaps if active polymerases are attached to the skeleton and replication and transcription occur as DNA is reeled through them. Cells of different tissues--and even cells of the same tissue--would have different attachments of this type. Problems associated with demonstrating these two kinds of attachment are discussed. We find little good evidence for 'structural' attachments and explore the idea that 'functional' attachments are the only kind that exist: 'functional' attachments involving active transcription units might be stable enough to organize chromatin during both interphase and mitosis, but 'dynamic' enough to allow duplication of attached sequences without disrupting loops.

Animals↗

PubMed1976

Electrophoretic analysis of substrate-attached proteins from normal and virus-transformed cells.

The proteins which have been left tightly bound to the tissue culture substrate after ethylenebis (oxyethyl-enenitrilo) tetraacetic acid (EGTA)-mediated removal of normal, virus-transformed, and revertant mouse cells and which have been implicated in the substrate adhesion process have been analyzed by slab sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Three size classes of hyaluronate proteoglycans were resolved in the 5% well gel; approximately half of the protein in the substrate-attached material coelectrophoresed with these polysaccharides-so-called glycosaminoglycan-associated protein(GAP). A portion of the GAP was shown to be highly heterogeneous and displaced from the polysaccharide by preincubation with calf histone before electrophoresis. The relative proportions of the proteoglycans varied in material deposited during a variety of cellular attachment and growth conditions. The remainder of the cellular protein in substrate-attached material was resolved as several major and distinct protein bands in 8 or 20% separating gels (a limited number of distinct serum proteins have also been identified as substrate bound). Protein C0 (molecular weight 220 000) was a prominent component in the material from a variety of normal and virus-transformed cells and resembled the so-called LETS or CSP glycoprotein in several respects; protein Ca was myosin-like in several respects; protein C2 was shown to be actin; and protein C1 (molecular weight 56 000) does not appear to be tubulin. Histones were also present in most preparations of substrate-attached material, particularly at high levels in transformed cell meterial, and may result from EGTA-mediated leakiness of the cell and subsequent binding to the negatively charged polysaccharide. These substrate-attached proteins were (a) prominent in substrate-attached material from many cell types in characteristic relative proportions, (b) deposited by EGTA-subcultured cells during the first hour of attachment to fresh substrate, (c) deposited by cells growing on plastic or glass substrates (three additional) components were also prominent in glass-attached material), and (d) deposited during long-term growth on or initial attachment to substrates coated wit 3T3 substrate-attached material. Pulse-chase analyses with radioactive leucine indicated that these proteins exhibit different turn-over behaviors. These results are discussed with regard to the possible involvement of these substrate-attached proteins in the substrate adhesion process, with particular interest in the interaction of cytoskeletal microfilaments with other surface membrane components and with regard to alteration of substrate adhesion by virus transformation.

Binding Sites↗

PubMed1995

Fibroblast growth factor-2 can mediate cell attachment by linking receptors and heparan sulfate proteoglycans on neighboring cells.

The myeloid 32D cell line, which grows in suspension and does not express FGF receptors or heparan sulfate proteoglycans, was transfected with the cDNA encoding FGF receptor-1 (32D-flg cells). When co-cultured with glutaraldehyde-fixed Chinese hamster ovary (CHO) cells, the 32D-flg cells remained in suspension in the absence of FGF-2 but attached to the CHO monolayer in the presence of 10 ng/ml FGF-2. In contrast, 32D cells transfected with the vector alone did not attach to the CHO monolayer in the presence of FGF-2. FGF-2-dependent attachment of 32D-flg cells was prevented by inclusion of 10 micrograms/ml heparin in the incubation medium and was diminished when CHO mutants in glycosaminoglycan synthesis or wild-type CHO cells treated with heparinase were used, indicating that the attachment occurred through FGF-2 interactions with heparan sulfates on the CHO cells. Attachment of 32D-flg cells to wild-type CHO cells was half-maximal at 0.4 ng/ml FGF-2 and was also observed with FGF-1 but not FGF-4. 32D-flg cells also attached to living CHO cells in a FGF-2-dependent manner, but attachment was transient at 37 degrees C. Induction of new proteins was not required for FGF-2-dependent attachment, since attachment occurred when the co-cultures were incubated at 4 degrees C and when the 32D-flg cells were preincubated with cycloheximide. FGF-2-dependent attachment of 32D-flg cells was also observed with Balb/C 3T3, NIH 3T3, and bovine capillary endothelial cells. We conclude that attachment is due to FGF-2 binding simultaneously to receptors on the 32D-flg cells and heparan sulfates on the CHO monolayers; thus, the FGF-2 acts as a bridge between receptor-expressing cells and heparan sulfate-bearing cells. In addition, induction of DNA synthesis in 32D-flg cells in response to FGF-2 was potentiated by the CHO-associated heparan sulfates to the same extent as by soluble heparin, indicating that this interaction has functional significance.

3T3 Cells↗

PubMed2005

Experiences of female general practice registrars: are rural attachments encouraging them to stay?

OBJECTIVE: To establish whether a six-month rural attachment influenced female GP registrars' future plans to work in a rural area. Secondary aims include establishing the adequacy of postgraduate training in preparing the registrars for the attachment, opinions regarding rural practice and suggestions to improve the attachment. DESIGN: A six-page questionnaire was sent to eligible participants via state branches of General Practice Education Australia. SUBJECTS: Female GP registrars who undertook a six-month rural attachment during 2002. MAIN OUTCOME MEASURE: Whether the six-month rural attachment influenced female registrars to practise in the country. RESULTS: The rural attachment was a positive experience for 82% of participants. One-third were more likely, as a result of the attachment, to practise rurally in the future. In total, 14% were influenced against working rurally as a result of the attachment. Those who had previously resided or studied in a rural area were more likely to plan to work rurally. Level of vocational preparation was adequate for the majority with notable deficits in obstetrics and gynaecological procedural skills. Main negatives associated with the attachment included working long hours and social isolation. Recommendations for change focused on amending these issues along with improved child-care facilities and improved remuneration. CONCLUSION: The rural attachment is a predominantly positive experience for female registrars with the exception of professional and personal hardships associated with relocating to rural practice. The attachment dissuades only a small proportion of its female counterparts, which is promising considering the increasing role of female practitioners in the workforce.

Adult↗

PubMed2004

Retention characteristics of attachment systems for implant overdentures.

PURPOSE: The aim of this study was to compare the retention characteristics of various overdenture attachment systems commonly used to retain overdentures to dental implants. MATERIALS AND METHODS: An edentulous mandibular model was constructed incorporating 2 parallel 4.0 mm x 13 mm Branemark implants placed in the canine regions. Attachments were embedded in a metal-reinforced experimental overdenture designed to be dislodged from the model by a universal testing machine. Tensile dislodging force was applied to the overdenture at a cross-head speed of 50 mm/min. Five overdentures were constructed for each of the attachment systems. The attachments evaluated were the Hader bar & metal clip, Locator LR pink, Locator LR white, Spheroflex ball, Shiner magnet, Maxi magnet, Magnedisc magnet, ERA white, and ERA gray. Each apparatus was tested with 5 specimens per attachment system. Peak load-to-dislodgement was measured. Analysis of variance and Scheffe multiple comparison tests were applied to the data with alpha< or = 0.05 level of significance. RESULTS: Peak load-to-dislodgement for all attachment systems ranged from 3.68 +/- 1.32 N to 35.24 +/- 1.99 N. Strain-at-dislodgement, calculated from stress-strain curves, ranged from 0.78 +/- 0.20% to 2.78 +/- 0.5%. The ERA gray attachment demonstrated the greatest retention, with a peak load-to-dislodgement of 35.24 +/- 1.99 N, and a relatively low strain-at-dislodgement of 1.64 +/- 0.09%. Less retention was recorded for the Locator LR white, Spheroflex ball, Hader bar & metal clip, and ERA white systems. The Locator LR pink attachment demonstrated still less retention with a load-to-dislodgement of 12.33 +/- 1.28 N. Significantly high strain-at-dislodgement was recorded for the Hader bar & metal clip and Locator nylon attachment systems. The lowest dislodging loads and strains were recorded for the Shiner magnet, Maxi magnet, and Magnedisc magnet attachments. CONCLUSIONS: Results suggest that the attachment systems evaluated may be grouped into high (ERA gray), medium (Locator LR white, Spheroflex ball, Hader bar & metal clip, ERA white), low (Locator LR pink), and very low (Shiner magnet, Maxi magnet, Magnedisc magnet) retention characteristics.

Analysis of Variance↗

PubMed1983

Role of attached gingiva for maintenance of periodontal health. Healing following excisional and grafting procedures in dogs.

The present study was undertaken to analyze the role of attached gingiva for the maintenance of periodontal health in sites with normal and reduced height of the supporting apparatus. Furthermore, the effect of excision and grafting of gingiva on some parameters describing dimensions and location of the periodontal tissues was evaluated. 7 beagle dogs were used. A baseline examination comprised assessments of dental plaque, gingival conditions, attachment level, position of the gingival margin and width of the keratinized and the attached gingiva. In the right side of the jaws (experimental side) a 6-month period of periodontal tissue breakdown was followed by surgical excision of the entire zone of the gingiva. After another 4-month period of healing with daily plaque control, a gingival graft was inserted in one quadrant of the experimental side to regain a zone of attached gingiva while the other quadrant of the experimental side was left ungrafted. In the left side of the jaws (control side), the teeth were subjected to daily meticulous plaque control during the entire study. In one of the control quadrants the entire zone of the keratinized and attached gingiva was excised at a time point corresponding to the grafting procedure in the experimental side, while the gingiva in the remaining control jaw quadrant was left unoperated. Clinical examinations of all control and experimental tooth units were repeated at certain time intervals during the course of the study. The final examination was carried out 4 months after grafting. The results of the experiment showed that in sites exposed to careful plaque control measures gingival health could be established and maintained without sign of recession of the gingival margin or loss of attachment, independent of (1) presence or absence of attached gingiva, (2) width of keratinized gingiva or (3) height of the supporting attachment apparatus. Following surgical excision of the entire gingiva, all buccal sites regained a zone of keratinized gingiva, but most sites were lacking attached gingiva. Furthermore, grafting of gingival tissue significantly increased the width of the keratinized and the attached gingiva but had no obvious effect on the position of the gingival margin or the level of the attachment.

Animals↗

PubMed1990

Isolation of a fibroblast attachment protein from cementum.

Cementum forms the interface through which soft connective tissue of the periodontium is attached to the root surface. The interactions between cementum and connective tissue are not completely understood and whether cementum influences periodontal connective tissue formation and regeneration is not clear. We have examined the effect of cementum components on the attachment of gingival fibroblasts. Cementum was harvested from healthy human and bovine teeth and extracted sequentially in 0.5 M CH3COOH, 4 M guanidine and bacterial collagenase. Fibroblast attachment was measured using 51Cr-labelled human gingival fibroblasts on tissue culture plates previously incubated with cementum components. Results showed that all three extracts mediated fibroblast attachment and attachment was dependent on concentration and incubation time. The attachment activity was not destroyed by digestion with bacterial collagenase or by antibodies to fibronectin and laminin. However, it was inhibited by a peptide containing the amino acid sequence RGD. By gel filtration or HPLC using a DEAE-cellulose column several proteins with attachment activity were fractionated. SDS-polyacrylamide gel electrophoresis revealed that HPLC fraction eluted by 0.2-0.3 M NaCl contained a protein with molecular weight 55 kDa as a major component. This protein was isolated and shown to promote fibroblast attachment, and optimal attachment occurred at a concentration of 2 micrograms/ml. We conclude that cementum contains substances capable of mediating fibroblast attachment and that these substances play an important role in periodontal connective tissue formation and regeneration by facilitating fibroblast attachment to root surfaces.

Amino Acid Sequence↗

PubMed1987

Involvement of both cellulose fibrils and a Ca2+-dependent adhesin in the attachment of Rhizobium leguminosarum to pea root hair tips.

We have previously described an assay for the attachment of Rhizobium bacteria to pea root hair tips (cap formation) which was used as a model to study the attachment step in the nodulation process. Under all conditions tested, a positive correlation was observed between the percentage of fibrillated cells and the ability of these bacteria to form caps and to adhere to glass, suggesting that fibrils play a role in the attachment of Rhizobium leguminosarum to pea root hair tips and to glass (G. Smit, J. W. Kijne, and B. J. J. Lugtenberg, J. Bacteriol. 168:821-827, 1986). In the present paper the chemical and functional characterization of the fibrils of R. leguminosarum is described. Characterization of purified fibrils by infrared spectroscopy and cellulase treatment followed by thin-layer chromatography showed that the fibrils are composed of cellulose. Purified cellulose fibrils, as well as commercial cellulose, inhibited cap formation when present during the attachment assay. Incubation of the bacteria with purified cellulase just before the attachment assay strongly inhibited cap formation, indicating that the fibrils are directly involved in the attachment process. Tn5-induced fibril-overproducing mutants showed a greatly increased ability to form caps, whereas Tn5-induced fibril-negative mutants lost this ability. None of these Tn5 insertions appeared to be located on the Sym plasmid. Both types of mutants showed normal nodulation properties, indicating that cellulose fibrils are not a prerequisite for successful nodulation under the conditions used. The ability of the fibril-negative mutants to attach to glass was not affected by the mutations, indicating that attachment to pea root hair tips and attachment to glass are (partly) based on different mechanisms. However, growth of the rhizobia under low Ca2+ conditions strongly reduced attachment to glass and also prevented cap formation, although it had no negative effect on fibril synthesis. This phenomenon was found for several Rhizobium spp. It was concluded that both cellulose fibrils and a Ca2+ -dependent adhesin(s) are involved in the attachment of R. leguminosarum to pea root hair tips. A model cap formation as a two-step process is discussed.

Adhesins, Bacterial↗

PubMed1984

Teamwork, myth or reality: community nurses' experience with general practice attachment.

A survey of 93 community nurses, 48 health visitors, and 45 district nurses was carried out in one area health authority where nurses had been attached to general practice schemes for up to 10 years. The purpose of the study was to determine the nurses' impression of teamwork within their attachment arrangements. Half the group surveyed had either a geographical area or other area health authority responsibilities, or both, in addition to their primary attachment commitment. No structured plan for preparing or evaluating attachment groups had been carried out by the area health authority. Only one third of attached nurses were working from premises shared with other members of the attachment group, and often facilities were poorly designed for teamwork. Health visitors were generally less enthusiastic about attachment and identified more obstacles in developing teamwork than did district nurses. Health visitors also tended to stay with individual attachment groups for shorter periods than did district nurses. Most nurses communicated frequently with attachment group members, but these opportunities were unplanned and usually limited to immediate problems of patient care. In a few attachments patterns of communication and collaboration appeared to be non-existent. Despite the problems identified in this study, most respondents prefer attachment to working solely in a geographical area and value their links the area health authority. Evaluation and positive direction is needed if the primary care team is to develop.

Communication↗

PubMed1994

Roles of serum vitronectin and fibronectin in initial attachment of human vein endothelial cells and dermal fibroblasts on oxygen- and nitrogen-containing surfaces made by radiofrequency plasmas.

Fluoropolymers modified by plasma modification were studied for their suitability as surfaces for the adhesion of cells. We compared films made by plasma modification of fluoroethylenepropylene (FEP) using nitrogen-containing gases (ammonia or dimethyl acetamide) with films deposited using oxygen-containing monomers (methanol, methyl methacrylate or sequential treatment with toluene then water). The surfaces were compared for the attachment and spreading of human vein endothelial cells and human dermal fibroblasts. The initial attachment and spreading of cultured fibroblasts and endothelial cells onto films deposited using nitrogen-containing gases were equivalent to that onto films deposited using oxygen-containing monomers, but there were some differences in the mechanism of attachment. With films deposited using oxygen-containing monomers, the initial attachment and spreading of endothelial cells failed when the medium contained 15% (v/v) serum from which both fibronectin (Fn) and vitronectin (Vn) had been removed. Similarly, initial attachment and spreading of endothelial cells onto films deposited using oxygen-containing monomers were reduced by 62-86% when the cells were seeded in medium containing Vn-depleted serum (which contained Fn). Endothelial cells attached and spread onto films made using oxygen-containing monomers, when seeded in medium containing Fn-depleted serum (which contained Vn). On films deposited using nitrogen-containing gases, the adhesion of endothelial cells was only slightly reduced in Vn-depleted medium (as compared to attachment in medium containing unmodified serum). Furthermore, surfaces which had incorporated nitrogen were more effective than were oxygen-containing films in adsorbing sufficient serum Fn as to promote endothelial cell attachment. Similar results were seen for the attachment and spreading of fibroblasts as for the endothelial cells. For fibroblasts, attachment and spreading onto oxygen-containing films and onto nitrogen-containing films were not simply dependent upon either the Vn content or the Fn content of the medium. Maximal attachment and spreading of fibroblasts were, however, dependent upon adsorption of both serum Vn and Fn.

Blood Proteins↗

PubMed1978

Attachment role of gonococcal pili. Optimum conditions and quantitation of adherence of isolated pili to human cells in vitro.

Gonoccocal pili facilitate attachment of virulent Neisseria gonorrhoeae to human cells. To characterize this attachment function, purified gonococcal pili isolated from four strains possessing antigenically distinct pili were radiolabeled with 125I and used to measure the attachment of pili to various human cells in vitro. Human buccal and cervical-vaginal mucosal epithealial cells, fallopian tube mucosa, and sperm bound pili in greater numbers per micrometer2 of surface area (1--10) than fetal tonsil fibroblasts, HeLa M cells, erythrocytes, or polymorphonuclear leukocytes. This cell specificity of attachment suggests a greater density of membrane pili binding sites on cells similar or identical to cells from natural sites of infection. The pili binding sites were quantitated as 1 X 10(4) per cervical-vaginal squamous cell. Pili of all antigenic types attached equally to a given cell type, implying that the attachment moiety of each pilus was similar. Attachement of gonoccocal pili to human cells occurred quickly with saturation of presumed receptor sites within 20--60 min. Attachment was temperature dependent (37 degrees greater than 20 degrees greater than 4 degrees C), and pH dependent (3.5 less than 4.5 less than 5.5 less than 7.5). Attachment was inhibited by antibody to pili (homologous pili Ab greater than heterologous Ab). The extent of possible protection against gonococcal infection due to inhibition of pili-mediated attachment might prove limited as a result of the considerable antigenic heterogeneity among pili and the observation that blockage of pili attachment is maximal only with antibody to pili of the infecting strain.

Antibodies, Bacterial↗

PubMed2000

Attachment and coercive sexual behavior.

This study examined the relationships between childhood attachment and coercive sexual behavior. One hundred sixty-two male undergraduate students completed self-report measures of childhood maternal attachment, childhood paternal attachment, adult attachment, antisociality, aggression, and coercive sexual behavior. As predicted, insecure childhood attachment, especially insecure paternal attachment, was associated with antisociality, aggression, and coercive sexual behavior. Moreover, childhood attachment independently predicted coercive sexual behavior after antisociality and aggression were statistically controlled. The hypothesis that paternal avoidant attachment would predict coercive sexual behavior independently of its relationship with aggression and antisociality was also supported. Posthoc analysis indicated that maternal anxious attachment was associated with antisociality and that paternal avoidant attachment was associated with both antisociality and coercive sexual behavior. These results are consistent with criminological and psychological research linking adverse early family experiences with offending and lend support to an attachment-theoretical framework for understanding offending behavior in general and sexual offending behavior in particular.

Adolescent↗

PubMed2026

Two worlds beneath: Distinct microbial strategies of the rock-attached and planktonic subsurface biosphere.

BACKGROUND: Microorganisms in groundwater ecosystems exist either as planktonic cells or as attached communities on aquifer rock surfaces. Attached cells outnumber planktonic ones by at least three orders of magnitude, suggesting a critical role in aquifer ecosystem function. However, particularly in consolidated carbonate aquifers, where research has predominantly focused on planktonic microbes, the metabolic potential and ecological roles of attached communities remain poorly understood. RESULTS: To investigate the differences between attached and planktonic communities, we sampled the attached microbiome from passive samplers filled with crushed carbonate rock exposed to oxic and anoxic groundwater in the Hainich Critical Zone Exploratory and compared it to a previously published, extensive dataset of planktonic communities from the same aquifer ecosystem. Microbial lifestyle (attached vs. planktonic) explained more variance in community composition than redox conditions, prompting us to further investigate its role in shaping functional and activity profiles. Metagenomic analysis revealed a striking taxonomic and functional segregation: the 605 metagenome-assembled genomes (MAGs) from attached communities were dominated by Proteobacteria (358 MAGs) and were enriched in genes for biofilm formation, chemolithoautotrophy, and redox cycling (e.g., iron and sulfur metabolism). In contrast, the 891 MAGs from planktonic communities were dominated by Cand. Patescibacteria (464 MAGs) and Nitrospirota (60 MAGs) and showed lower functional versatility. Only a few genera were shared, and even closely related MAGs (> 90% average nucleotide identity) differed in assembly size and metabolic traits, demonstrating lifestyle-specific functional adaptation. Analysis of active replication indicated that the active fraction of the attached community was primarily represented by the most abundant MAGs. Planktonic communities featured a higher fraction of active MAGs compared to attached communities, but overall with lower relative abundances. CONCLUSIONS: The high abundance, metabolic specialization, and carbon fixation potential of attached microbes suggest that they are key drivers of subsurface biogeochemical processes. Carbonate aquifers may act as much larger inorganic carbon sinks than previously estimated based on CO2 fixation rates of the planktonic communities alone. Our findings underscore the need to incorporate attached microbial communities into models of subsurface ecosystem function. Video Abstract.

Plankton↗

PubMed1993

Diverse mechanisms for cell attachment to platelet thrombospondin.

Thrombospondin-1 is a component of the extracellular matrix which is thought to play important roles in cell migration and proliferation, during embryogenesis and wound repair. To understand the basis for these activities, we are mapping the regions of the molecule with cell adhesive activity. Here, we use antagonists of specific cell binding sites, adhesion-perturbing thrombospondin monoclonal antibodies and proteolytic fragments of platelet thrombospondin, to investigate the adhesive mechanisms used by G361 melanoma cells, human intestinal smooth muscle cells (HISM), epidermal keratinocytes and MG-63 osteosarcoma cells. When attached to the same preparations of platelet thrombospondin, HISM and MG-63 cells underwent spreading, whereas G361 cells and keratinocytes did not. Attachment of all four cell types involved the carboxyterminal domain. The type 1 repeats and the amino-terminal heparin binding domain were important for stable attachment of G361, HISM and MG-63 cells, but were not involved in keratinocyte attachment. GRGDSP peptide caused near complete inhibition of HISM and MG-63 cell attachment, partially inhibited G361 attachment, but did not inhibit keratinocyte attachment. Attachment of HISM and MG-63 cells involved the alpha v beta 3 integrin. The integrity of the thrombospondin molecule was important for its adhesivity towards G361, HISM, and MG-63 cells, whereas keratinocytes attached to the 140 kDa tryptic fragment as effectively as they did to the intact molecule. These results show that cell attachment to platelet thrombospondin typically involves multiple binding interactions, but the exact profile of interactions is cell type specific. Usage of particular cell-binding sites does not predict whether cells will undergo spreading or not. These data may, in part, explain some of the current controversies surrounding the mechanisms of cell attachment to thrombospondin.

Amino Acid Sequence↗

PubMed2001

Checkpoint signals in grasshopper meiosis are sensitive to microtubule attachment, but tension is still essential.

The spindle checkpoint detects errors in kinetochore attachment to microtubules and delays anaphase if attachment is improper. The checkpoint is activated by attachment-sensitive components including Mad2 and certain phosphorylated proteins detected by the 3F3/2 antibody. We have studied Mad2 and 3F3/2 immunofluorescence in grasshopper spermatocytes. As in other cells, unattached kinetochores are loaded with Mad2 and are highly phosphorylated, whereas after proper attachment, Mad2 is lost and kinetochores are dephosphorylated. What is it about proper attachment that produces these changes--is it microtubule attachment itself or is it the tension from mitotic forces that follows proper attachment? Using micromanipulation, we created an intermediate state, weak attachment, that provides an answer. Weakly attached kinetochores are not under tension and have few kinetochore microtubules. Despite the absence of tension, many weakly attached kinetochores lose their Mad2 and become dephosphorylated. Therefore we conclude that microtubule attachment determines both Mad2 binding and phosphorylation. Nevertheless, tension plays an absolutely essential role. Tension elevates the number of kinetochore microtubules to the level necessary for the complete loss of Mad2 and dephosphorylation from all kinetochores. This gives a reliable 'all clear' signal to the checkpoint, allowing the cell to progress to anaphase.

Animals↗

PubMed1999

Attachment style and adult love relationships and friendships: a study of a group of women at risk of experiencing relationship difficulties.

This study examines the relationship between attachment style and love relationships and friendships in a group of women (N = 40) known to be at risk of experiencing relationship problems. The association between attachment style and measures of self-esteem and depression were also investigated. Women with a secure attachment style had more positive ratings in the domain of adult love relationships than women with insecure attachment style (avoidant and ambivalent) and difficulties in adult love relationships were found to be particularly related to an avoidant attachment style. Insecure attachment style was also related to having cohabited with a deviant partner. Adult attachment style was not found to be related to ratings of current mood but was significantly related to self-esteem and to ratings of functioning in the domain of adult friendships. In particular, participants with an anxious-ambivalent attachment style had more negative self-esteem than secure participants. Secure participants had more positive ratings in the domain of adult friendships than insecure participants and a moderately significant association was also found between difficulties in the domain of adult friendships and an anxious-ambivalent attachment style. In addition, 20% (N = 8) of the women also reported attachment styles characterized by high levels of avoidance and ambivalence: this group was found to have more pervasive difficulties in their close relationships than women who endorsed a single dominant attachment style.

Adult↗