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D S Jones

Publications and source records attributed to D S Jones.

At least 37 records · Page 2Linked to original sources
PubMed1999

Impaired endothelial-dependent forearm vascular relaxation in black Americans.

BACKGROUND: Hypertension is a major cause of morbidity and mortality in the general population and has an even more significant impact on the black community in particular. Explaining the interethnic differences has been difficult. Differences in endothelial function may provide some insight into the causes of the increased incidence of hypertension in the black population versus their white cohorts. METHODS: In this study 16 black subjects and 12 white subjects received brachial artery infusions of acetylcholine (12.5, 25, and 50 microg/min) and angiotensin II (3.82, 9.55, and 19.10 ng/min). Measurement of forearm vascular resistance by venous occlusion plethysmography was conducted. RESULTS: The dose of acetylcholine at 50% maximal observed response (EC50) for black subjects was 10.6+/-2.39 microg/min and 3.3+/-0.44 microg/min in the white subjects (mean +/- SEM; P < .05). Sodium nitroprusside infusions at 1 and 2 microg/min did not cause a significant difference in response between the 2 groups. After angiotensin II was infused, forearm vascular resistance Emax was 3.42+/-0.78 mm Hg/100 mL tissue volume/min for black subjects and 3.16+/-0.99 mm Hg/100 mL tissue volume/min for white subjects. CONCLUSION: This study shows impaired endothelial-dependent forearm vascular relaxation as measured by decreased acetylcholine response in black subjects. This impairment in endothelial function may contribute to the increased incidence of hypertension in black subjects compared with white subjects. Mechanisms for this finding warrant further investigation.

Acetylcholine↗
PubMed1999

Physicochemical characterization and preliminary in vivo efficacy of bioadhesive, semisolid formulations containing flurbiprofen for the treatment of gingivitis.

In this study, the physicochemical properties and preliminary in vivo clinical performance of formulations containing hydroxyethylcellulose (HEC; 3, 5, 10% w/w), poly(vinylpyrrolidone) (PVP; 3, 5% w/w), polycarbophil (PC; 1, 3, 5% w/w), and flurbiprofen (5% w/w) were examined. Flurbiprofen release into PBS pH 7.4 was performed at 37 degrees C. The mechanical properties (hardness, compressibility, adhesiveness, initial stress) and syringeability of formulations were determined using a texture analyzer in texture profile analysis (TPA) and compression modes, respectively. In general, the time required for release of 10 and 30% of the original mass of flurbiprofen (t10%, t30%) increased as the concentration of each polymeric component increased. However, in the presence of either 5 or 10% HEC and 5% PC, increased PVP concentration decreased both t10%, t30% due to excessive swelling (and disintegration) of these formulations. Increased concentrations of HEC, PVP, and PC significantly increased formulation hardness, compressibility, work of syringe expression, and initial stress due to the effects of these polymers on formulation viscoelasticity. Similarly, increased concentrations of PC (primarily), HEC, and PVP increased formulation adhesiveness due to the known bioadhesive properties of these polymers. Clinical efficacies of formulations containing 3% HEC, 3% PVP, 3% PC, and either 0% (control) or 5% (test) flurbiprofen, selected to offer optimal drug release and mechanical properties, were evaluated and clinically compared in an experimental gingivitis model. The test (flurbiprofen-containing) formulation significantly reduced gingival inflammation, as evaluated using the gingival index, and the gingival crevicular fluid volume, whereas, these clinical parameters were generally increased in volunteers who had received the control formulation. There were no observed differences in the plaque indices of the two subject groups, confirming that the observed differences in gingival inflammation could not be accredited to differences in plaque accumulation. This study has shown both the applicability of the in vitro methods used, particularly TPA, for the rational selection of formulations for clinical evaluation and, additionally, the clinical benefits of the topical application of a bioadhesive semisolid flurbiprofen-containing formulation for the treatment of experimental gingivitis.

Acrylic Resins↗
PubMed1999

Plasma and red blood cell fatty acids in peroxisomal disorders.

The demonstration of abnormal levels of fatty acids or plasmalogens in plasma or red blood cells is key to the diagnosis of peroxisomal disorders. We report the levels of 62 fatty acids and plasmalogens in patients with X-linked adrenoleukodystrophy (X-ALD), Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD), both at baseline and after dietary interventions. "Lorenzo's Oil" therapy in X-ALD normalizes the levels of saturated very long chain fatty acids in plasma, but leads to reduced levels of omega 6 and other omega 3 fatty acids, and requires monitoring and appropriate dietary supplements. Patients with ZS, NALD and IRD have reduced levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) which can be normalized by the oral administration of microencapsulated DHA and AA.

Adolescent↗
PubMed1999

Amsorb: a new carbon dioxide absorbent for use in anesthetic breathing systems.

BACKGROUND: This article describes a carbon dioxide absorbent for use in anesthesia. The absorbent consists of calcium hydroxide with a compatible humectant, namely, calcium chloride. The absorbent mixture does not contain sodium or potassium hydroxide but includes two setting agents (calcium sulphate and polyvinylpyrrolidine) to improve hardness and porosity. METHODS: The resultant mixture was formulated and subjected to standardized tests for hardness, porosity, and carbon dioxide absorption. Additionally, the new absorbent was exposed in vitro to sevoflurane, desflurane, isoflurane, and enflurane to determine whether these anesthetics were degraded to either compound A or carbon monoxide. The performance data and inertness of the absorbent were compared with two currently available brands of soda lime: Intersorb (Intersurgical Ltd., Berkshire, United Kingdom) and Dragersorb (Drager, Lubeck, Germany). RESULTS: The new carbon dioxide absorbent conformed to United States Pharmacopeia specifications in terms of carbon dioxide absorption, granule hardness, and porosity. When the new material was exposed to sevoflurane (2%) in oxygen at a flow rate of 1 l/min, concentrations of compound A did not increase above those found in the parent drug (1.3-3.3 ppm). In the same experiment, mean +/-SD concentrations of compound A (32.5 +/- 4.5 ppm) were observed when both traditional brands of soda lime were used. After dehydration of the traditional soda limes, immediate exposure to desflurane (60%), enflurane (2%), and isoflurane (2%) produced concentrations of carbon monoxide of 600.0 +/- 10.0 ppm, 580.0 +/- 9.8 ppm, and 620.0 +/-10.1 ppm, respectively. In contrast, concentrations of carbon monoxide were negligible (1-3 ppm) when the anhydrous new absorbent was exposed to the same anesthetics. CONCLUSIONS: The new material is an effective carbon dioxide absorbent and is chemically unreactive with sevoflurane, enflurane, isoflurane, and desflurane.

Absorption↗
PubMed1999

Lack of a regular source of care among children using a public hospital emergency department.

OBJECTIVES: This study examined risk factors for not having a regular source of care among children presenting to an urban public hospital for nonappointment care. Lack of a regular source of care is associated with decreased use of appropriate health care services and preventive care among children. METHODS: A cross-sectional survey was conducted for all children less than 16 years of age attending an emergency department at an urban public hospital over a consecutive 7-day period. Univariate and multivariate logistic regression analyses were conducted. RESULTS: In 791 interviews available for analysis, 52% of preschool children and 66% of school-aged children did not have a regular source of care. Children without a regular source of care were more likely to present for nonurgent conditions (P < 0.0005). In multivariate analysis, older age of the child (OR = 1.6, 95% CI 1.132.25), lack of insurance (OR = 1.47, 95% CI 1.03-2.11), and lack of personal vehicle (OR = 1.44, 95% CI 1.05-1.97) were associated with not having a regular source of care. CONCLUSIONS: The majority of children using an urban emergency department were without a regular source of care. In this population, no single factor identified children without a regular source of care, but increased age and lack of insurance were associated with it. Addressing this situation will require a multifaceted approach that includes, but is not limited to, decreasing financial barriers.

Adolescent↗
PubMed1999

Suprascapular nerve block for the treatment of frozen shoulder in primary care: a randomized trial.

BACKGROUND: Frozen shoulder is a common problem in general practice, but its treatment is difficult since none of the currently used therapies are proven to be effective. AIM: To assess the effectiveness of suprascapular nerve block to relieve pain and improve range of movement, and its suitability for use in primary care. This small study by a single practitioner aims to justify a larger multicentred trial. METHOD: A randomized trial of 30 patients to compare a single suprascapular nerve block with a course of intra-articular injections. Patients' pain levels and ranges of movement were assessed over a 12-week period. RESULTS: Suprascapular nerve block produced a faster and more complete resolution of pain and restoration of range of movement than a series of intra-articular injections. These differences were confirmed by statistical analysis using the Mann-Whitney U-test (P < 0.01 for pain levels and P < 0.05 for range of abduction and external rotation.) CONCLUSIONS: This study suggests that suprascapular nerve block is a safe and effective treatment for frozen shoulder in primary care, and justifies a larger multicentred trial using independent blinded assessment. Such a study should include a third group treated by suprascapular nerve block without steroid; a more comprehensive assessment of patient debility.

Anesthetics, Local↗
PubMed1998

Structural characterization and optimization of antibody-selected phage library mimotopes of an antigen associated with autoimmune recurrent thrombosis.

The presence of high titers of anti-cardiolipin antibodies (ACA's) of autoimmune origin, which are known to bind to plasma beta2-glycoprotein I (aka apolipoprotein H), correlates clinically with autoimmune recurrent thrombosis. Soluble beta2-glycoprotein I binds to solid-phase ACA (immobilized on a surface plasmon resonance chip) with a Kd of 1.4 microM, but if the reactants are reversed and beta2-glycoprotein I is on the solid-phase support, then the Kd is 52 nM. This 27-fold difference in affinity reflects the avidity/entropic advantage obtained for an antibody binding to an antigen that is made multivalent because it is attached to a solid phase. A mimotope of this antigen, selected from a phage display peptide library screen with an ACA, has been shown to bind to solid-phase ACA as a phage, using surface plasmon resonance. This peptide is representative of the motif from 37 peptides obtained in a previously reported phage library screen with this ACA (1). A synthetic version of this peptide, referred to as P4, has the sequence: A1G2P3C4I5L6L7A8R9D10R11C12P13G14, and binds to its selecting antibody with a Kd of 42 nM. NMR data indicate that proline-13 is present in both cis and trans configurations, and that these two geometries dramatically affect the overall tertiary structure of the molecule. The peptide lacking this proline binds severalfold better to the ACA, consistent with at least one of these structures having low affinity for binding ACA. Replacement of the arginine-9 position with a proline decreases binding affinity to ACA 10-fold. Another phage library-selected peptide has a proline in position 9, but also has a leucine in position 5, instead of isoleucine. Since its affinity for ACA is nearly as good as that for peptide P4, the phage library screening must have selected for a non-beta-branched amino acid in this position to compensate for the adverse effects of the arginine-9 to proline-9 substitution. The solution structure of a modified version of the antibody-selected phage peptide P4 with the central proline was determined. This peptide has one turn comprised of Ala-Pro-Asp-Arg, with the proline peptide bond in the cis configuration, and another turn that contains the disulfide and adjacent residues. If the disulfide is replaced by a thioether, and the central proline by an alpha-methyl proline, in an attempt to make the peptide more biologically stable, there is little adverse effect on affinity for ACA. The thioether bond/turn is fairly well defined with a Calpha to Calpha separation of 4.9 +/- 0.8 A. The alpha-methyl proline adopts the trans configuration, and this central Ala-(alpha-methyl-Pro)-Asp-Arg turn adopts a distorted type I turn conformation with a probable i to i+3 hydrogen bond. Modeling studies suggest that the proline peptide bond configuration switched from cis to trans in the presence of the alpha-methyl group on proline because of steric hindrance with the beta-carbon of the preceding residue. Overall, this peptidomimetic molecule is structurally very similar to the peptide with natural amino acids, with an rmsd difference of only 1.37 A, when comparing backbone atoms.

Antibodies, Anticardiolipin↗
PubMed1998

Transcutaneous access to retrograde axonal flow.

Transcutaneous entry of fluorescent tracer and subsequent retrograde neuronal transport achieved by the use of dimethyl sulfoxide (DMSO) as a vehicle fluorescent dye dissolved in DMSO and applied topically to the hind limb of rats was found in corresponding dorsal root ganglia; aqueous absorption of tracer dye by neuronal tissue was not demonstrated. This example of transcutaneous access and retrograde transport may have implications as to the entry of various toxins, viruses, chemicals, and therapeutic agents to the nervous system.

Administration, Cutaneous↗
PubMed1998

Evolution of the gibbon subgenera inferred from cytochrome b DNA sequence data.

DNA sequences for the mitochondrial cytochrome b gene from the four extant gibbon subgenera are described. The data confirm that the gibbon subgenera evolved from a common hylobatid ancestor and suggest that they diverged from each other after the divergence of the extant African great ape species. The cytochrome b gene does not resolve the evolutionary relationships between the gibbon subgenera themselves.

Animals↗
PubMed1998

Viscoelastic properties of bioadhesive, chlorhexidine-containing semi-solids for topical application to the oropharynx.

PURPOSE: This study examined the viscoelastic properties of bioadhesive, chlorhexidine-containing semi-solid formulations, designed for topical application to the oropharynx. METHODS: Oscillatory rheometry was performed using a Carri-Med CSL2-100 rheometer at 20.0 +/- 0.1 degrees C in conjunction with parallel plate geometry (2 cm diameter, 0.5 mm sample thickness). Samples were subjected to a constant strain (6.5 x 10(-3) rad) and defined viscoelastic parameters, namely storage modulus (G'), loss modulus (G"), loss tangent (tan delta) and dynamic viscosity (eta'), measured over a defined frequency range (0.01-1.0 Hz). RESULTS: As the oscillatory frequency was increased, G' G" of all formulations increased, whereas both eta' and tan delta significantly decreased. The magnitude of increase of G' and G" as a function of frequency was relatively small, indicating that, in general, the formulations were non-cross-linked elastic systems. Increasing concentrations of HEC, PVP and PC significantly increased G', G", eta' yet decreased tan delta, observations that may be attributed to the physical state of each polymer in the formulations. Formulation elasticity increased (i.e. tan delta decreased) as a result of increased entanglement of polymeric chains of dissolved components (i.e. HEC and PVP) and the restrained extension of swollen, cross-linked chains of PC. Additionally, in formulations where the saturation solubility of PVP was exceeded and/or insufficient "free-water" was available for maximal swelling of PC, formulation elasticity increased as a result of the increasing mass of dispersed solid particles of PVP and/or PC. Formulation eta' increased due to the attendant effects of polymer chain entanglement and polymer state on overall formulation viscosity. CONCLUSIONS: Following application to the oropharynx, the formulations will behave as elastic systems. Thus, these formulations would be expected to offer advantageous clinical properties, e.g., prolonged drug release, increased bioadhesion. However, it is noteworthy that the final choice of formulation for clinical evaluation will involve a compromise between viscoelastic characteristics and acceptable textural properties, e.g. ease of product application. This study has shown the applicability of oscillatory rheometry for both the characterisation and selection of candidate, topical bioadhesive formulations for clinical evaluation.

Acrylic Resins↗
PubMed1998

A chemically defined, toleragen-based approach for targeting anti-beta2-glycoprotein I antibodies.

Antiphospholipid syndrome is characterized by a prothrombotic state and the presence of beta2-glycoprotein I (beta2-GPI)-dependent antiphospholipid antibodies. The feasibility of a B cell tolerance-based approach for specific reduction of anti-beta2-GPI antibodies was investigated. Anti-beta2-GPI antibodies isolated from a patient with antiphospholipid syndrome were used to screen peptide libraries expressed in phage, resulting in the identification of a phage that specifically bound anti-beta2-GPI antibodies. The phage-displayed peptide was identified and chemically optimized to generate a synthetic 14-mer peptide with an internal thioether linkage (LJP 685) that retained the binding profile of the original phage. LJP 685 was conjugated to a defined, non-immunogenic organic platform to generate a tetravalent presentation of LJP 685 for use as a toleragen. Tetravalent LJP 685 induced a dose-dependent reduction in antibody levels in mice previously immunized and boosted with LJP 685 coupled to the carrier keyhole limpet hemocyanin. These experiments support the technical feasibility of a tolerance-based approach for reducing anti-beta2-GPI antibodies in vivo.

Amino Acid Sequence↗
PubMed1997

Role of physiological conditions in the oropharynx on the adherence of respiratory bacterial isolates to endotracheal tube poly(vinyl chloride).

Pneumonia is a major problem in intensive care patients and can be induced by pathogenic bacteria adhering to poly(vinyl chloride) (PVC) endotracheal (ET) tubes. This study examines the influence of surface properties on the adherence of the respiratory isolates Staphylococcus aureus and Pseudomonas aeruginosa to PVC. In particular, the influence of respiratory tract physiological conditions, 5% CO2 and saliva, on adherence was investigated. In general, decreased adherence to PVC was observed when bacteria were grown in CO2. When these CO2-grown bacteria were treated with saliva their adherence to PVC significantly increased; however, their adherence was significantly reduced to saliva-treated PVC. Treatment of both bacterial isolates with saliva decreased their negative zeta potential, a factor which may directly contribute to the observed increased microbial (saliva pretreated) adherence to PVC. Cell surface hydrophobicity (CSH) was evaluated by measuring the initial rates of microbial removal from a buffered aqueous phase, to ensure the absence of electrostatic interactions, to an organic phase (xylene). Under physiological conditions, CSH did not appear to be a dominant factor in biomaterial adherence as the CSH of S. aureus was decreased by saliva treatment but was unchanged for Ps. aeruginosa. Additionally, CSH also differed for the two isolates when grown in CO2, significantly decreasing with S. aureus but remaining unaltered with Ps. aeruginosa. Saliva treatment of PVC also decreased the advancing and receding contact angles of the biomaterial and its surface roughness, which may be a factor in the decreased adherence of saliva-treated bacteria to this surface. Alternative biomaterials or surface modifications appear necessary for the desired improvements in ET tube effectiveness. This study highlights the influence of physiological conditions on biomaterial and bacterial surface characteristics and subsequent interactions. It is imperative that the physiological conditions predominating in the clinical area of biomaterial use be considered when investigating device biocompatibility.

Bacterial Adhesion↗
PubMed1997

Mechanical performance of polyurethane ureteral stents in vitro and ex vivo.

A serious problem associated with the use of ureteral stents is fracture in situ. Following clinical observations of fracture of polyurethane stents in vivo, this study examined the mechanical properties of 17 polyurethane stents (double-J containing drainage holes) retrieved from patients over a 24-week period of insertion. In addition, stents were immersed in human and artificial urine in an in vitro model at 37 degrees C to determine their general propensity to fracture. Mechanical properties of ureteral stents were examined using the standard ASTM D-412 tensile test and by the novel application of dynamic mechanical analysis (DMA). The ultimate tensile strength and elongation at break (but not the Young's modulus) of unused polyurethane stent sections containing side-drainage holes were greater than stent sections devoid of side-drainage holes. No correlations were observed between increased or decreased Young's modulus, ultimate tensile strength or elongation at break of polyurethane stents and their time of immersion in either human urine or artificial urine in simulated upper urinary tract conditions of 37 degrees C and 5% CO2. Similarly, no correlations were observed between Young's modulus, ultimate tensile strength or elongation of polyurethane stents and stent dwell time in situ. DMA of retrieved stents revealed that their tan delta value and storage modulus did not differ significantly from unused stents following dwell times in situ of up to 24 weeks. No changes in the glass transition temperatures were observed in retrieved stents. Although patient variation was observed, the results indicate that the polyurethane stents examined in vitro and following removal from patients did not exhibit any greater propensity to fracture than their unused counterparts. Fracture of retrieved polyurethane stents, arising in vivo and also during subsequent tensile testing, was observed to occur along the drainage holes, suggesting that elimination of these holes will reduce the incidence of polyurethane ureteral stent fracture in use.

Biocompatible Materials↗
PubMed1997

Textural analysis and flow rheometry of novel, bioadhesive antimicrobial oral gels.

PURPOSE: This study examined the rheological and textural characteristics (hardness, compressibilty, adhesiveness and cohesiveness) of bioadhesive oral gels containing the antimicrobial agent chlorhexidine. METHODS: Textural analysis was performed using a Stable Micro Systems texture analyser (model TA-XT 2) in texture profile analysis (TPA) mode. In this, an analytical probe was twice compressed into each formulation to a defined depth (15 mm) and at defined rates (2, 4, 6, 8, 10 mm s-1), allowing a delay period (15 s) between the end of the first and beginning of the second compressions. Flow rheograms were performed using a Carri-Med CSL2-100 rheometer with parallel plate geometry under controlled shearing stresses at 20.0 +/- 0.1 degrees C. RESULTS: All formulations exhibited pseudoplastic flow with thixotropy. Increasing concentrations of each polymer significantly increased formulation hardness, compressibility, adhesiveness and zero-rate viscosity. Increased hardness and compressibility were due to the attendent increased viscosities of these formulations. Increased adhesiveness was related to the concentrations of the (bioadhesive) polymers employed in these formulations and, in addition, was dependent on the physical state of polycarbophil. Formulation viscosity contributed to product adhesiveness, reflecting the importance of product rheology on this parameter. Decreased formulation cohesiveness, observed as the concentrations of the PVP, PC and HEC (3-5% w/w) were increased, was due an increase in semi-solid character. Numerical values of hardness, compressibility and adhesiveness were affected by the choice of probe speed, a parameter related to rate of shear in flow rheometry. Statistical interactions were observed and were assigned to the effects of HEC on the physical state of PVP (dissolved or dispersed) and PC (swollen or unswollen). CONCLUSIONS: This study has demonstrated both the applicability of textural analysis for the mechanical characterisation of bioadhesive semi-solid gel systems and, additionally, the direct influence of viscosity on the parameters defined by textural analysis, namely, hardness, compressibility and adhesiveness.

Adhesives↗
PubMed1997

The effects of hexetidine (Oraldene) on the adherence of Candida albicans to human buccal epithelial cells in vitro and ex vivo and on in vitro morphogenesis.

PURPOSE: This study reports the effects of hexetidine (Oraldene) on two virulence attributes of Candida albicans, namely, in vitro and ex vivo adherence of yeast cells to buccal epithelial cells (BEC) and in vitro morphogenesis. METHODS: The effects of hexetidine treatment of either yeast cells (stationary and exponential phases) or BEC on Candidal adherence, in terms of viable and non-viable adherent yeast cells, were evaluated using an acridine orange stain in conjunction with fluorescence microscopy. Ex vivo anti-adherence effects were determined by rinsing BEC in vivo with hexetidine (0.1%), removal of BEC after defined periods and inclusion in the adherence assay. The effects of hexetidine on morphogenesis were evaluated using light microscopy. Yeast cell viability following exposure to a range of concentration of hexetidine (0.005-0.1% v/v) for defined periods was determined following serial dilution and enumeration on solid media. RESULTS: Treatment of stationary and exponential phase yeast cells or BEC with hexetidine (0.1%) for a range of times (10-300 s) or, alternatively, with a range of concentrations of hexetidine (0.005-0.1%) for a fixed time (30s) significantly decreased the resultant Candidal/ epithelial adhesion. No correlations were observed between reduced adherence and either time of treatment or hexetidine concentration. In vivo treatment of BEC with hexetidine (0.1%) for 30s resulted in prolonged and significant reductions in the ex vivo adherence of both viable and non-viable yeast cells for periods of up to (and including) four hours post-rinsing. Treatment of C. albicans blastospores with hexetidine (0.05, 0.1% v/v) for 10s and 30s totally inhibited Candida morphogenesis, whereas treatment with lower antiseptic concentrations significantly reduced the extent of Candida morphogenesis and the rate of hyphal development. The effects of hexetidine on yeast cell viability were both concentration and time-dependent. CONCLUSIONS: The reduced adherence of C. albicans to BEC and the modification or inhibition of morphogenesis following exposure to hexetidine suggests a clinical role for hexetidine in the prophylaxis of both superficial candidosis and the systemic complications resulting from invasion of sub-epithelial tissue.

Antifungal Agents↗
PubMed1997

Conditioning fluid influences on the surface properties of silicone and polyurethane peritoneal catheters: implications for infection.

Catheter-related infection remains a considerable problem in continuous ambulatory peritoneal dialysis (CAPD). This study examined the adherence of clinical isolates of Staphylococcus epidermidis to commercially available polyurethane and silicone peritoneal catheters in the presence and absence of a proteinaceous conditioning film. In addition, the effects of the conditioning film on the surface properties (advancing and receding contact angles, and surface rugosity) of these biomaterials were investigated. Bacterial adherence to polyurethane and silicone catheters, pre-treated with phosphate-buffered saline (PBS) or artificial spent peritoneal dialysate (ASD) for 1 h at 37 degrees C, was examined using a radiometric (2-3H-adenine) adherence assay. The advancing and receding contact angles and the surface rugosity of ASD- and PBS-treated biomaterials were examined using a dynamic contact angle analyser and an atomic force microscope, respectively. The bacterial isolates were selected to represent high and low cell surface hydrophobicity. The hydrophobic isolate exhibited both a significantly greater rate and a significantly greater extent of adherence than the hydrophilic isolate to both catheter materials, independent of pre-treatment. In general, pre-treatment of the catheter materials with ASD significantly decreased the subsequent adherence of both isolates owing to the deposition of a conditioning film on the surface of the biomaterial. ASD treatment also decreased both the advancing and receding contact angles and the surface rugosity of both catheter materials. This study highlights the influence of both bacterial cell surface hydrophobicity and biomaterial surface conditioning films on bacterial adherence to CAPD catheters. In addition, it is recommended that the effects of proteinaceous conditioning films on biomaterial surface properties should be considered when assessing materials for medical devices and products.

Journal Article↗