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J B Matthews

Publications and source records attributed to J B Matthews.

At least 19 recordsLinked to original sources
PubMed2003

Comparison of the cytotoxicity of clinically relevant cobalt-chromium and alumina ceramic wear particles in vitro.

Concern over polyethylene wear particle induced aseptic loosening of metal-on-polyethylene hip prostheses has led to renewed interest in alternative materials such as metal-on-metal and alumina ceramic-on-alumina ceramic for total hip replacement. This study compared the effects of clinically relevant cobalt-chromium and alumina ceramic wear particles on the viability of U937 histiocytes and L929 fibroblasts in vitro. Clinically relevant cobalt-chromium wear particles were generated using a flat pin-on-plate tribometer. The mean size of the clinically relevant metal particles was 29.5+/-6.3 nm (range 5-200 nm). Clinically relevant alumina ceramic particles were generated in the Leeds MkII anatomical hip simulator from a Mittelmieier prosthesis using micro-separation motion. This produced particles with a bimodal size distribution. The majority (98%) of the clinically relevant alumina ceramic wear debris was 5-20 nm in size. The cytotoxicity of the clinically relevant wear particles was compared to commercially available cobalt-chromium (9.87 microm+/-5.67) and alumina ceramic (0.503+/-0.19 microm) particles. The effects of the particles on the cells over a 5 day period at different particle volume (microm(3)) to cell number ratios were tested and viability determined using ATP-Lite(TM). Clinically relevant cobalt-chromium particles 50 and 5 microm(3) per cell reduced the viability of U937 cells by 97% and 42% and reduced the viability of L929 cells by 95% and 73%, respectively. At 50 microm(3) per cell, the clinically relevant ceramic particles reduced U937 cell viability by 18%. None of the other concentrations of the clinically relevant particles were toxic. The commercial cobalt-chromium and alumina particles did not affect the viability of either the U937 histiocytes or the L929 fibroblasts.Thus at equivalent particle volumes the clinically relevant cobalt-chromium particles were more toxic then the alumina ceramic particles. This study has emphasised the fact that the nature, size and volume of particles are important in assessing biological effects of wear debris on cells in vitro.

Aluminum↗
PubMed2003

Effects of clinically relevant alumina ceramic wear particles on TNF-alpha production by human peripheral blood mononuclear phagocytes.

The recent introduction of microseparation of the components of ceramic-on-ceramic hip prostheses during hip simulations has produced clinically relevant wear rates, wear patterns and wear particles. This provided an opportunity to determine the response of primary human peripheral blood mononuclear cells to clinically relevant alumina ceramic wear particles in vitro. Alumina ceramic wear particles were generated in a hip joint simulator under microseparation conditions. The particles showed a bi-modal size distribution with nanometer sized (5-20nm) and larger particles (0.2->10 micrometer). The particles were cultured with human peripheral blood mononuclear cells obtained from six different donors at particle volume to cell number ratios of 1, 10, 100 and 500 micrometer(3). After 24h incubation the viability of the cells and the levels of TNF-alpha were determined. The response to the microseparation wear particles was compared to that of commercially available alumina powder with a uniform morphology and mean size of 0.5 micrometer. All six Donors PBMNC produced significantly elevated levels of TNF-alpha when stimulated with 100 micrometer(3) of the alumina powder per cell. Volumetric concentrations of 10 and 1.0 micrometer(3) per cell failed to stimulate a significant response by the cells from any of the six donors. Three of the six Donors PBMNC secreted significantly elevated levels of TNF-alpha when stimulated with 100 micrometer(3) of the microseparation wear particles, whereas the other three failed to respond to the wear debris at this concentration. All of the Donors PBMNC produced significantly elevated levels of TNF-alpha when stimulated with 500 micrometer(3) of the microseparation wear particles per cell. Thus, a greater volume of the microseparation wear particles was required to activate the PBMNC than the alumina powder. This was probably due to the microseparation wear particles having fewer particles in the critical size range (0.1-1 micrometer) for macrophage activation compared to the alumina powder. It can be concluded that alumina ceramic wear particles generated under microseparation conditions are capable of inducing osteolytic cytokine production by human mononuclear phagocytes. However, the volumetric concentration of the particles needed to generate this response is extremely high and given the low wear rates (<4mm(3) per million cycles) of ceramic-on-ceramic bearings, even under severe microseparation conditions, it is unlikely that this concentration threshold will be achieved in vivo.

Aluminum↗
PubMed2003

Levels of TGFbeta1 in gingival crevicular fluid during a 21-day experimental model of gingivitis.

OBJECTIVE: TGFbeta1 is a multifunctional growth factor with both pro- and anti-inflammatory properties. This study aimed to determine levels of TGFbeta1 in gingival crevicular fluid (GCF), serum and plasma in the early stages of gingival inflammation. DESIGN: A 21-day experimental model of gingivitis employing a split mouth design with a soft vinyl splint used to cover test teeth during brushing. SUBJECTS: Ten healthy volunteers (mean age 21 years; five males and five females). METHODS: GCF and blood (with and without EDTA) was collected on days 0, 7, 14 and 21. GCF volumes were measured on a precalibrated Periotron 8000TM. Clinical indices of gingival inflammation and plaque levels were obtained after GCF sampling. Normal brushing resumed after GCF collection on day 21 and final samples were collected on day 35. TGFbeta1 and alkaline phosphatase (ALP) levels were determined using enhanced chemiluminescent methods. RESULTS: Clinical indices and GCF volumes increased at test sites during the 21-day test period. Concentrations of TGFbeta1 and ALP in GCF (test and control), serum and plasma did not change throughout the study (P > 0.3). However, total amounts of TGFbeta1 (pg sample-1) and ALP (mu IU sample-1) in GCF increased at test sites and were significantly higher than baseline values at days 7, 14 and 21 (P < 0.04). Control sites showed no variation in TGFbeta1 or ALP levels throughout the study period (P > 0.35). All parameters at test sites returned to control levels at day 35 (P > 0.3). CONCLUSION: The data indicate that GCF TGFbeta1 levels increase early in plaque-induced inflammation. Whether the biological consequence of this site-specific increase is pro- or anti-inflammatory in nature remains to be elucidated.

Adult↗
PubMed2003

Salivary gland expression of transforming growth factor beta isoforms in Sjogren's syndrome and benign lymphoepithelial lesions.

AIM: Transforming growth factor beta (TGF-beta) is involved in the control of autoimmune reactions, cell proliferation, and the accumulation of lymphocytes within organs. The aim of this study was to determine the expression of TGF-beta in salivary glands from patients with primary Sjogren's syndrome (SS) and benign lymphoepithelial lesions (BLEL) with emphasis on ductal epithelium. METHODS: Immunoperoxidase staining for TGF-beta isoforms and Ki67 antigen was performed on formalin fixed sections of labial glands from patients with primary SS (n = 15) and controls (n = 5) and parotid glands reported as BLEL (n = 5) or normal (n = 5). Ductal expression of TGF-beta was quantified by absorbance measurements using image analysis. The specificity of staining was confirmed by peptide blocking studies. RESULTS: All TGF-beta isoforms were detected within the cytoplasm of most lymphocytes, endothelial cells, and ducts in all specimens. Acinar expression was variable and weaker than that seen in ducts. Absorbance measurements revealed that the expression of all isoforms was greater in ducts within primary SS glands than in control glands. Ductal expression in control parotid glands was greater than that seen in BLEL glands, irrespective of the presence of adjacent lymphoid infiltrates. Comparisons between control specimens showed that ductal expression of all isoforms was highest in parotid glands, whereas no differences were detected between primary SS and BLEL glands. Ki67 positive lymphocytes and duct cells were mainly restricted to pathological specimens, with BLEL glands containing larger populations of positive cells than primary SS glands. CONCLUSION: These results demonstrate complex and variable changes in ductal expression of TGF-beta in primary SS and BLEL, which may be important in the control of lymphoid infiltration and the proliferation of lymphocytes and ductal epithelium.

Adolescent↗
PubMed2002

Antigen-specific IgG(T) responses in natural and experimental cyathostominae infection in horses.

Equine clinical larval cyathostominosis is caused by simultaneous mass emergence of previously inhibited larvae from the mucosa of the colon. Clinical signs include diarrhoea, colic, weight loss and malaise, and in up to 50% of cases, the disease results in death. Cyathostominae spend a large part of their life cycle as larval stages in the intestinal mucosa. Definitive diagnosis is difficult due to the lack of diagnostic methods for pre-patent infection. In the present study, the enzyme-linked immunosorbent assay (ELISA) was used to investigate isotype responses to larval cyathostominae somatic antigen. Measurement of anti-larval IgG(T) responses appeared to have the most immunodiagnostic potential. An increase in IgG(T) response was detected to crude larval antigen by 5 weeks post-infection (PI) in individual infected ponies. Subsequently, IgG(T) responses to larval and adult somatic extracts were examined by Western blotting using sera from experimentally-infected horses and helminth-naive animals (n=6). Two antigen complexes, designated A and B, in larval somatic antigen were recognised specifically by the infected animals by 7 weeks PI. Sera taken from 23 endemically-infected animals, whose cyathostominae burdens had been enumerated, were also used to identify putative diagnostic antigens. Eighteen horses had positive mucosal worm burdens (range 723-3,595,725) and all but two of these animals had serum IgG(T) antibody specific to either complex. Moreover, IgG(T) responses specific to antigen complexes A and B were absent in all five parasite negative horses that were tested. Serum IgG(T) responses to either of the two complexes were identified in five clinical cases tested. IgG(T) responses to adult antigen somatic extracts were more heterogeneous, with no clear pattern between experimentally-infected ponies and helminth-free controls. The results indicate that increases in serum IgG(T) to mucosal larvae occur in the pre-patent period and that two antigenic complexes within somatic preparations of these stages have immunodiagnostic potential.

Animals↗
PubMed2002

Analysis of incisor pulp cell populations in Wistar rats of different ages.

Pulp cell function and viability is important for maintaining tooth vitality throughout life. However, the effects of ageing on pulpal cell populations and pulp tissue remodelling are still unclear. The aim here was to quantify age-related cell-density changes in the pulp of rat incisor teeth, using histomorphometric analysis and ANOVA. Mandibular (n=35) and maxillary (n=34) incisors were carefully extracted from 20 Wistar rats aged between 1 and 18 months, fixed and processed for light microscopy. Cell counts were performed in mature and immature regions at both labial and lingual aspects of all teeth. Odontoblast and subodontoblast cell densities were reported per mm of pulp-dentine border and core fibroblast density per mm2 pulp tissue. Irrespective of age, odontoblast and subodontoblast densities were lower in the immature than the mature regions of both maxillary and mandibular incisors (P<0.001). However, in both regions odontoblast and subodontoblast densities decreased significantly with increasing age (P<0.0001). The age-related reduction in odontoblasts was significantly greater in mature than immature regions (P<0.02) but not influenced by other variables. In contrast, the age-related reduction in subodontoblasts was significantly different between mandibular and maxillary teeth (P=0.012) but not influenced by site. Unlike odontoblasts and subodontoblasts, core fibroblasts showed small but significant increases with increasing age (P<0.0001). These age-related reductions in the density of odontoblasts and subodontoblasts may partly explain the slower rate of secondary dentine secretion and decreased pulp repair activity associated with ageing.

Aging↗
PubMed2002

Ability of structurally diverse natural products and synthetic chemicals to induce gene expression mediated by estrogen receptors from various species.

The ability of 14 structurally diverse estrogenic compounds to induce reporter gene expression mediated by estrogen receptors (ERs) from different species was examined. MCF-7 cells were transiently transfected with a Gal4-regulated luciferase reporter gene (17m5-G-Luc) and Gal4-ER chimeric receptors containing the D, E and F domains of the human alpha (Gal4-hERalphadef), mouse alpha (Gal4-mERalphadef), mouse beta (Gal4-mERbetadef), chicken (Gal4-cERalphadef), green anole (Gal4-aERalphadef), Xenopus (Gal4-xERdef) or rainbow trout alpha ERs (Gal4-rtERalphadef). The efficacy of 17beta-estradiol (E2) in inducing reporter gene expression was similar among the different constructs overall, with EC(50) values ranging from 0.05 to 0.7nM. However, Gal4-rtERalphadef had an EC(50) value at 37 degrees C of 28nM, though at 20 degrees C an EC(50) value of 1nM was observed. Despite a similar response to E2 treatment among the ERs, many differences were observed in the magnitude of the response to other structurally diverse chemicals. For example, coumestrol induced Gal4-mERbetadef- and Gal4-aERdef-mediated reporter gene expression 164- and 8-fold greater, respectively, than mediated with the other Gal4-ERs. As well, in contrast to results with other Gal4-ERs, alpha-zearalenol consistently induced Gal4-rtERalphadef-mediated reporter gene activity at lower concentrations than did E2. Overall, the results demonstrate that selected estrogenic compounds exhibit a differential ability to induce reporter gene activity mediated by ERs from different vertebrate species. These data also highlight the importance of incubation temperature when examining rtERalpha-mediated activity.

Animals↗
PubMed2002

Stress and the periodontal diseases: effects of catecholamines on the growth of periodontal bacteria in vitro.

Microorganisms possess the ability to recognize hormones within the host and utilize them to adapt to their surroundings. Noradrenaline and adrenaline, which are released during human stress responses, may act as environmental cues to alter the growth of individual organisms within subgingival biofilms. The aims of this study were to modify, for anaerobic culture, existing methodology used in determining microorganism catecholamine responses and to investigate the growth responses to noradrenaline and adrenaline of 43 microorganisms found within subgingival microbial complexes. We established initial inocula for each strain using anaerobic culture, re-inoculated into a minimal serum-based medium and grown anaerobically at 35 degrees C. We assessed organism growth by optical density (OD(600nm)) readings, with test and control cultures performed in triplicate. Test cultures were supplemented with 50 microm noradrenaline or 100 microm adrenaline. We observed significant growth effects for supplementation with noradrenaline (20 species responding positively) and adrenaline (27 species responding positively), with differences in growth response observed within bacterial species and within and between microbial complexes. The most pronounced positive growth effects of noradrenaline were demonstrated in Actinomyces naeslundii (+ 49.4%), Actinomyces gerenscseriae (+ 57.2%), Eikenella corrodens (+ 143.3%) and Campylobacter gracilis (+ 79.9%). We also observed inhibitory effects of noradrenaline supplementation for Porphyromonas gingivalis (- 11.9%) and Bacteroides forsythus (- 22.2%). Responses to adrenaline tended to mirror the responses seen with noradrenaline. Individual organisms from different microbial complexes vary in their in vitro growth responses to noradrenaline and adrenaline. Such variation may influence the in vivo composition of the subgingival biofilm in response to stress-induced changes in local catecholamine levels and play a significant role in the aetiology and pathogenesis of the periodontal diseases.

Actinomyces↗
PubMed2002

Cytokine mRNA expression pattern in horses with large intestinal disease.

The aim of this study was to investigate cytokine expression patterns in the large intestinal mucosa of horses, particularly in diseases associated with inflammation. Many cases of equine colitis remain without a definitive diagnosis and survival rates are poor. In humans, colitis is associated with increased expression of pro-inflammatory cytokines. To examine if similar responses occur in horses, we investigated il -2, il -4, il -5, il -10, tnfalpha, ifngamma and tgfbeta messenger rna expression in large intestinal mucosa. Samples were obtained from animals with large intestinal disease (n=15) or from horses which had different levels of cyathostomin infection (n=9) and analysed by reverse transcription-polymerase chain reaction. il -2 was detected at all sites, whilst il -4 was detected at all but one site. The presence of il -10, il -5, ifngamma and tgfbeta varied with no significant differences amongst groups (P>0.4). Detection of tnfalpha was significantly different between the group of horses that had infiltrative inflammatory bowel disease and those with larval cyathostominosis (P=0.028) and those that were helminth negative (P=0.014). These results indicate a possible role for tnfalpha in the pathogenesis of equine infiltrative inflammatory bowel disease.

Animals↗
PubMed2002

Glutathione in gingival crevicular fluid and its relation to local antioxidant capacity in periodontal health and disease.

AIMS: To determine possible changes in gingival crevicular fluid (GCF) antioxidant defence in chronic adult periodontal disease and to investigate the nature of the local radical scavenging mechanisms, with particular reference to glutathione. METHODS: GCF and plasma were collected from patients with chronic periodontitis and age and sex matched control subjects (n = 10). Polymorphonuclear leucocytes (PMNLs) were prepared and gingival epithelial cells (GECs) were collected by conventional methods from periodontally healthy subjects. PMNL were stimulated with F-Met-Leu-Phe after cytochalasin B treatment. Enhanced chemiluminescence was used to determine the total antioxidant capacity and to investigate the activity of cell fractions and reducing agents. GCF concentrations of reduced (GSH) and oxidised (GSSG) glutathione were determined by high performance liquid chromatography. RESULTS: Plasma and GCF from patients contained lower mean (SD) total antioxidant capacity (501.8 (123) micro M Teq/litre and 658.3 (392) micro M Teq/litre, respectively) compared with controls (577.9 (99.8) and 1351.5 (861) micro M Teq/litre, respectively). Antioxidant light recovery profiles for GCF demonstrated a stepped response, not seen in plasma, which was inhibited by N-ethylmaleimide. This response was also detected in the cytosolic fraction of GEC and anaerobically stimulated PMNL. Similar antioxidant profiles, inhibitable by N-ethylmaleimide, were obtained with cysteamine, cysteine, and GSH. Control GCF contained high mean (SD) concentrations of glutathione (GSH, 1899.8 (494.4) micro M; GSSG, 256.8 (152.4) micro M). GCF from patients with periodontitis contained significantly lower amounts of GSH (mean, 1183.1; SD, 580.3 micro M) and GSSG (mean, 150.1; SD, 44.9 micro M). CONCLUSIONS: GSH values and total antioxidant capacity are reduced in chronic periodontal disease. The high concentrations of GSH present in GCF in health are similar to those found extracellularly in the lung and may represent an important antioxidant and anti-inflammatory defence strategy common to exposed epithelial surfaces.

Adult↗
PubMed2001

Reciprocal mutagenesis between human alpha(L349, M528) and rainbow trout (M317, I496) estrogen receptor residues demonstrates their importance in ligand binding and gene expression at different temperatures.

Several fish proteins exhibit compromised function at temperatures outside of their normal physiological range. In this study, the effect of temperature on the ligand binding and the transactivation abilities of the rainbow trout estrogen receptor (rtER) and human estrogen receptor alpha (hER alpha) were examined. Saturation analysis and gene expression assays, using GST-ER and Gal4-ER fusion proteins consisting of the D, E and F domains of human (hER alpha def) and rainbow trout (rtERdef) receptors, show that GST-rtERdef E2 binding affinity and transactivation ability decrease with increasing temperature. A comparison of the amino acid sequence differences between their ligand binding pockets identified two conservative amino acid residue substitutions in rtER (M317, I496) and hER alpha (L349, M528). The effect of these substitutions on ligand binding and transactivation were examined by constructing reciprocal mutants, which effectively exchanged the binding pockets between rtER and hER alpha. The rtERdef M317L:I496M double mutant exhibited increased E2 binding affinity and transactivation ability at higher temperatures, and displayed hER alpha phenotypic behavior for the phytoestrogen, coumestrol. The hER alpha def L349M:M528I double mutant also exhibited a modest trend towards adopting the rtER phenotype. These studies demonstrate that conservative changes in residue hydrophobicity and volume can significantly affect ER ligand binding and transactivation ability in a temperature-dependent manner. The lack of a complete exchange of phenotypes between rtER and hER alpha indicates that factors outside of the ligand binding pocket are also involved.

Amino Acid Sequence↗
PubMed2001

Interaction of PAH-related compounds with the alpha and beta isoforms of the estrogen receptor.

The ability of several 4- and 5-ring polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs, and their monohydroxy derivatives to interact with the estrogen receptor (ER) alpha and beta isoforms was examined. Only compounds possessing a hydroxyl group were able to compete with 3H-labeled 17beta-estradiol (E2) for binding to either a glutathione-S-transferase and human ERalpha D, E, and F domain fusion protein (GST-hERalphadef) or to the full-length human ERbeta. Competitive binding was comparable for both isoforms, with IC(50) values ranging from 20 to 300 nM (E2 IC(50) approximately 3 nM). However, several compounds were able to induce reporter gene expression preferentially through mERbeta, using MCF-7 cells transiently transfected with either a Gal4-human ERalphadef or Gal4-mouse ERbetadef construct, as well as a Gal4-regulated reporter. These data extend the number and type of PAH-related compounds capable of interacting with ERalpha and ERbeta, and provides additional evidence that even though some compounds may possess a similar affinity for both ER isoforms, the capacity for transcriptional activation can still be isoform-specific.

Animals↗
PubMed2001

Decreased expression of TGF-beta cell surface receptors during progression of human oral squamous cell carcinoma.

This study examined the immunocytochemical expression of the transforming growth factor-beta (TGF-beta) isoforms TGF-beta1, TGF-beta2, and TGF-beta3, together with the TGF-beta cell surface receptors TbetaR-I and TbetaR-II, in patient-matched tissue pairs of normal human oral epithelium, primary squamous cell carcinomas, and metastatic lymph node tumour deposits. There were no significant differences in the intensity of TGF-beta isoform specific staining between the normal oral epithelium, the primary tumours, and the lymph node metastases. By contrast, there was significantly less TbetaR-II in the metastases than in the primary tumour and between the primary tumour and the normal oral epithelium. Similar trends were evident with TbetaR-I, but not at a statistically significant level. This study also examined the structure of TbetaR-I and TbetaR-II in normal human oral keratinocytes in vitro and in 14 human oral carcinoma cell lines with known responses to TGF-beta1. No structural abnormalities of TbetaR-II were present in the normal keratinocytes or in 13 of 14 malignant cell lines; in one line, there were both normal and mutant forms of TbetaR-II, the latter being in the form of a frameshift mutation with the insertion of a single adenine base (bases 709-718, codons 125-128), predicting a truncated receptor having no kinase domain. No defects were present in TbetaR-I. The structures of TbetaR-I and TbetaR-II did not correlate with growth inhibition by TGF-beta1. The data suggest that decreased expression of TGF-beta receptors, rather than structural defects of these genes, may be important in oral epithelial tumour progression. In order to examine the functional significance of a specific decrease in TbetaR-II expression, a dominant-negative TbetaR-II construct (dnTbetaR-II) was transfected into a human oral carcinoma cell line with a normal TGF-beta receptor profile and known to be markedly inhibited by TGF-beta1. In those clones that overexpressed the dnTbetaR-II, growth inhibition and Smad binding activity were decreased, whilst the regulation of Fra-1 and collagenase-1 remained unchanged following treatment with TGF-beta1. The results demonstrate that a decrease in TbetaR-II relative to TbetaR-I leads to selective gene regulation with loss of growth inhibition but continued transcription of AP-1-dependent genes that are involved in the regulation of the extracellular matrix.

Adult↗
PubMed2001

Immunisation of cattle with recombinant acetylcholinesterase from Dictyocaulus viviparus and with adult worm ES products.

Dictyocaulus viviparus causes a serious lung disease of cattle. For over 30 years, a radiation-attenuated larval vaccine has been used with success; however, this vaccine has several disadvantages. A more stable vaccine against D. viviparus, capable of stimulating prolonged protective immunity, would be beneficial. Recent research has been directed at adult worm ES components that may be involved in parasite survival in the host. One component is the secreted enzyme, acetylcholinesterase (AChE), a target for circulating antibody in infected calves. Here, we describe a study where protection was investigated in calves immunised with either native adult ES products or a recombinant parasite AChE. These antigens were administered twice with Freund's incomplete adjuvant. Subsequently, all calves were challenged with 700 L3 and their worm burdens and immune responses compared with those in calves that received an anthelmintic-abbreviated infection and challenge control calves. Significant levels of protection were not obtained in the immunised groups but significant immunity was achieved in the calves that received the anthelmintic abbreviated infection. Antibody responses amongst the groups were different, with significantly higher IgG1 responses in the immune, infected group and in adult ES recipients. Significantly higher IgG2 responses were found in the latter group. Following challenge, the groups that received the abbreviated infection and the fusion protein produced specific antibody that bound the native enzyme. No differences were observed between groups in peripheral blood mononuclear cell responsiveness to either antigen. However, adult ES products appeared to have a mitogenic effect on these cells, whilst the fusion protein exhibited an inhibitory effect. These results suggest that in this form, AChE is not a potential vaccine candidate and that adult ES products, in contrast to previous experiments in guinea pigs, do not contain protective components.

Acetylcholinesterase↗
PubMed2001

Evaluation of the specificity of five oligoprobes for identification of cyathostomin species from horses.

Here, we report evaluation of five oligoprobes designed from intergenic spacer (IGS) region sequences for identification of cyathostomin species. Oligoprobes were designed for identification of Cylicocyclus ashworthi, Cylicocyclus nassatus, Cylicostephanus longibursatus, Cylicostephanus goldi and a fifth probe designed to identify all members of this tribe. PCR amplification of IGS DNA from 16 cyathostomin species allowed sequence comparison and identification of four putative species-specific probes. Southern blotting of amplified products from 16 species showed that all probes were species-specific. The fifth probe recognised all 16 cyathostomin species but did not bind to members of the genus Strongylus. Furthermore, these probes were used to identify individual infective L3, eggs and L4 indicating that they will be invaluable to furthering the study of the epidemiology and pathogenesis of these important equine nematodes.

Animals↗
PubMed2001

An evaluation of the capacity of differently prepared demineralised bone matrices (DBM) and toxic residuals of ethylene oxide (EtOx) to provoke an inflammatory response in vitro.

Demineralised bone matrix (DBM) is a form of allogeneic tissue graft widely used in oral and maxillofacial procedures. There is a long history of controversy relating to the suitability of ethylene oxide gas (EtOx) as a terminal sterilisation agent for this graft, relating to its effects on the clinical performance of the grafts. Furthermore, the generation of a toxic residual chemical (ethylene chlorohydrin, ECl) during the ethylene oxide sterilisation of patellar tendon allografts has been implicated in the failure of these grafts owing to the induction of a localised inflammatory response. In this study we have investigated the capacity of a range of different DBM preparations, and ECl dilutions, to induce the production of three pro-inflammatory cytokines, interleukin-6 (IL-6), interleukin-1beta (IL-1beta), and tumour necrosis factor alpha (TNF-alpha) from human peripheral blood mononuclear cells (PBMNCs). The levels of EtOx and ECl in EtOx terminally sterilised DBM and mineralised bone grafts were measured by gas chromatography. It was found that the only factor capable of rendering DBM pro-inflammatory was the presence of small (<20 micrometre diameter) DBM particles. No other processing or sterilisation technique resulted in the DBM becoming pro-inflammatory. Although it was also found that DBM, when EtOx-sterilised, retained more ECI than mineralised bone grafts following a standard EtOx sterilisation protocol, ECl did not provoke an inflammatory response in vitro at levels up to and including those which are cytotoxic to PBMNCs.

Bone Demineralization Technique↗
PubMed2001

Percutaneous treatment of a pancreatic fistula after pancreaticoduodenectomy.

Breakdown of the pancreaticojejunal anastomosis after a Whipple procedure is reported to occur in as many as 15% of cases. Intraoperative placement of a drain adjacent to the anastomosis is performed to allow the creation of a controlled pancreaticocutaneous fistula in the event of an anastomotic disruption. The authors present a case of successful percutaneous treatment of a disrupted pancreaticojejunal anastomosis. This was achieved with use of the resulting pancreaticocutaneous fistula for access to restore internal drainage, followed by fistula occlusion with use of gelatin pledgets.

Anastomosis, Surgical↗