Biomedical subjects

Christopher Barry

Publications and source records attributed to Christopher Barry.

17 recordsLinked to original sources

PubMed2007

A long-term review of posterior colporrhaphy with Vypro 2 mesh.

The objective is to study the long-term outcomes of posterior colporrhaphy with composite polyglactin 910-polypropylene mesh (Vypro 2, Ethicon, Somerville, NJ, USA) utilizing an overlay technique. Seventy-eight patients involved in our previous study were contacted 3 years after their initial operation for follow-up (Lim YN, Rane A, Muller R, Int Urogynecol J 16:126-131, 2005). Thirty-seven (47%) returned for follow-up and completed a standardized questionnaire survey, whereas a further 16 (20%) returned their postal questionnaires. Mean age was 61.3 (SD 10.8) years, and follow-up was 35.7 (SD 4.5) months. There were statistically significant improvements in vaginal lump sensation and constipation (p < 0.001) but no differences with defecatory difficulties or dyspareunia. De novo dyspareunia was reported in 27%. On examination, the incidences of mesh vaginal erosion and rectocele recurrence were 30% and 22%, respectively. It appears that posterior colporrhaphy incorporating Vypro 2 mesh with an overlay method is associated with unacceptably high incidence of complications.

Aged↗

PubMed2006

TVT vs Monarc: a comparative study.

Following the success of the tension-free vaginal tape (TVT), there has been considerable interest in technique modifications such as the transobturator approach for implant placement. We attempted to elucidate possible anatomical and clinical differences between the two methods in a retrospective cohort study. One hundred and fourteen women who had undergone TVT or Monarc implantation were assessed by or under the supervision of the senior author, with identical tensioning technique. They were followed up by an interview, uroflowmetry, and translabial 3D ultrasound. There were significant differences for patient satisfaction (P=0.013), subjective overall cure/improvement (P=0.0018), and the symptom of poor stream (P=0.03), all favoring the Monarc group. On imaging Monarc tapes appeared more proximal at rest (P=0.006) and Valsalva (P=0.002) and remained further from the symphysis pubis on Valsalva (P=0.01). At 9 months follow-up, there was no significant difference as regards to cure rates for stress incontinence between the two suburethral slings. Monarc tapes are located more proximally and may be less obstructive, judging from a lower incidence of symptoms of voiding dysfunction. Patient satisfaction and overall subjective cure/improvement were higher after Monarc. In summary, the Monarc is an effective TVT alternative, achieving cure of stress incontinence by similar means. It may be less obstructive, resulting in improved patient satisfaction.

Female↗

PubMed2006

Dissociating word frequency and age of acquisition: The Klein effect revived (and reversed).

The Klein effect (G. S. Klein, 1964) refers to the finding that high-frequency words produce greater interference in a color-naming task than low-frequency words. The present study used the Klein effect to investigate the relationship between frequency and age of acquisition (AoA) by measuring their influence on color naming. Two experiments showed reliable effects of frequency (though in the opposite direction to that reported by Klein) but no effects of AoA. Experiment 1 produced a dissociation between frequency and AoA when manipulated orthogonally. Experiment 2 produced the same dissociation using different stimuli. In contrast, both variables reliably influenced word naming. These findings are inconsistent with the view that frequency and AoA are 2 aspects of a single underlying mechanism.

Adult↗

PubMed2006

Written spelling to dictation: Sound-to-spelling regularity affects both writing latencies and durations.

The authors examined the effect of sound-to-spelling regularity on written spelling latencies and writing durations in a dictation task in which participants had to write each target word 3 times in succession. The authors found that irregular words (i.e., those containing low-probability phoneme-to-grapheme mappings) were slower both to initially produce and to execute in writing than were regular words. The regularity effect was found both when participants could and could not see their writing (Experiments 1 and 2) and was larger for low- than for high-frequency words (Experiment 3). These results suggest that central processing of the conflict generated by lexically specific and assembled spelling information for irregular words is not entirely resolved when the more peripheral processes controlling handwriting begin.

Adolescent↗

PubMed2006

Repetition priming of access to biographical information from faces.

Two experiments examined repetition priming on tasks that require access to semantic (or biographical) information from faces. In the second stage of each experiment, participants made either a nationality or an occupation decision to faces of celebrities, and, in the first stage, they made either the same or a different decision to faces (in Experiment 1) or the same or a different decision to printed names (in Experiment 2). All combinations of priming and test tasks produced clear repetition effects, which occurred irrespective of whether the decisions made were positive or negative. Same-domain (face-to-face) repetition priming was larger than cross-domain (name-to-face) priming, and priming was larger when the two tasks were the same. It is discussed how these findings are more readily accommodated by the Burton, Bruce, and Johnston (1990) model of face recognition than by episode-based accounts of repetition priming.

Association Learning↗

PubMed2006

Are age-of-acquisition effects on object naming due simply to differences in object recognition? Comments on levelt (2002).

Levelt (2002) argued that apparent effects of word frequency and age of acquisition (AoA) reported in recent picture naming studies might actually be confounded effects operating at the level of object recognition, rather than relevant to theories of lexical retrieval. In order to investigate this issue, AoA effects were examined in an object recognition memory task (Experiments 1 and 2) and a word-picture verification task (Experiment 3) and compared with those found in naming tasks using the same pictures. Contrary to Levelt's concerns, the results of the three experiments show that the AoA effect on picture naming has a lexical origin and does not simply result from a possible confound of object identification times.

Adolescent↗

PubMed2005

Does the MONARC transobturator suburethral sling cause post-operative voiding dysfunction? A prospective study.

The aim of this study was to compare pre-operative and post-operative voiding parameters following insertion of the MONARC transobturator tape (TOT), for treating women with urodynamic stress incontinence. This prospective observational study was conducted at a tertiary referral urogynaecology unit, in North Queensland, involving 83 women who were prospectively assessed pre-operatively and at 6-8 weeks following the procedure. Information collected included patient demographics, concomitant surgery, pre-operative and post-operative symptomatology (using validated questionnaires), and pre-operative and post-operative urodynamic parameters. Parameters used to assess voiding function included symptoms of voiding difficulty (incomplete emptying and irritative symptoms) as well as objective parameters including maximum flow rate (Qmax), adjusted maximum flow rate (Qmaxadj) using the Liverpool nomogram (LN), maximal urethral pressure, and post-void residual (PVR). Pre-operative average Qmax was 23.7 ml/s compared to 21.1 ml/s post-operatively (p=0.064). When the Qmax was adjusted for voided volume using the LN, Qmaxadj was seen to decrease significantly from 26 ml/s to 18 ml/s (p<0.05). Women with PVR>50 ml did not differ significantly pre-operatively and post-operatively, 5/83(6%) vs 7/83 (8.4%) (p=0.75). The number of women with a flow rate <10th centile on LN was 22 (26.5%) pre-operatively vs 29 (34.9%) post-operatively (p=0.21). One (1.2%) post-operatively had voiding dysfunction diagnosed by an abnormal voiding pattern (p=0.728), which was not statistically significant. Objective voiding dysfunction as determined by adjusted flow rates <10th centile LN and >50 ml PVR was seen in four women (4.8%). Adjusted free flow rates are significantly reduced following insertion of the MONARC TOT, as are some symptoms related to voiding dysfunction. Despite this, satisfaction rates remain high with observed voiding dysfunction or objective measures of voiding dysfunction showing no statistical change in the short term. Long-term follow-up is planned at 1 year.

Female↗

PubMed2005

Suburethral slingplasty evaluation study in North Queensland, Australia: the SUSPEND trial.

OBJECTIVE: To compare the safety and efficacy of three types of suburethral slings for the treatment of urodynamic stress incontinence. METHODS: Following ethics approval, 195 (3 x 65) patients with urodynamic stress incontinence were randomly assigned to undergo suburethral slingplasty with the Tension-free Vaginal Tape (TVT; Gynecare, Ethicon, Somerville, NJ, USA), Intravaginal Sling (IVS; Tyco Healthcare, Mansfield, MA, USA), or Suprapubic Arc Sling (SPARC; American Medical Systems, Minnetonka, MN, USA). The patients were blinded to the type of sling implanted. MAIN OUTCOME MEASURES WERE: (1) operative and short-term complications; (2) pre- and postoperative symptomatology; and (3) pre- and postoperative urodynamic findings. RESULTS: There was a statistically significant increased rate of sling protrusion (13.1% vs. 3.3% and 1.7%; P = 0.04) in the SPARC group when compared to TVT and IVS. Otherwise, there were no significant differences between the groups with respect to the incidences of other operative complications, patients' main subjective outcomes, satisfaction rates, or postoperative urodynamic findings. The overall objective stress incontinence cure rates were 87.9%, 81.5% and 72.4% for the TVT, IVS, SPARC groups respectively (P = 0.11). CONCLUSIONS: All three slings appear quite successful for the treatment of stress incontinence. The SPARC tapes showed more sling protrusion complications and a trend towards lower objective cure rates; probably as a result of the insertion method used in this study which favoured a loose SPARC sling placement. The authors recommend that the SPARC slings be left tighter than TVT, or for the cough test to be carried out.

Aged↗

PubMed2005

Transobturator tape for stress incontinence: the North Queensland experience.

A prospective observational study of 96 patients undergoing insertion of the MONARC transobturator tape (American Medical Systems, Minnetanka, USA) for treatment of urodynamic stress incontinence was conducted to investigate its' the safety and efficacy. Although there were no major intraoperative complications, sling protrusion was observed in 11/91 patients (12.1%) at early follow up visits. At these visits, 80 women (87.9%) were either completely or substantially continent and 74 women (81.3%) were satisfied with the operation. Objectively, 74 women (81.3%) were cured on urodynamic assessment and only one woman (1.1%) was found to have voiding dysfunction. As a conclusion, it would appear that this new technique is effective for the treatment of stress incontinence; but further studies are needed to investigate its long-term results and complications.

Adult↗

PubMed2005

Biomechanical studies of an artificial disc implant in the human cadaveric spine.

OBJECT: The authors compared the biomechanical performance of the human cadaveric spine implanted with a metallic ball-and-cup artificial disc at L4-5 with the spine's intact state and after anterior discectomy. METHODS: Seven human L2-S1 cadaveric spines were mounted on a biomechanical testing frame. Pure moments of 0, 1.5, 3.0, 4.5, and 6.0 Nm were applied to the spine at L-2 in six degrees of motion (flexion, extension, right and left lateral bending, and right and left axial rotation). The spines were tested in the intact state as well as after anterior L4-5 discectomy. The Maverick disc was implanted in the discectomy defect, and load testing was repeated. The artificial disc created greater rigidity for the spine than was present after discectomy, and the spine performed biomechanically in a manner comparable with the intact state. CONCLUSIONS: The results indicate that in an in vitro setting, this model of artificial disc stabilizes the spine after discectomy, restoring motion comparable with that of the intact state.

Aged↗

PubMed2005

Age of acquisition effects in the semantic processing of pictures.

In two experiments, we investigated the role of age of acquisition (AoA) in the categorizing of objects in semantic tasks that do not require access to the object names. In both a found inside or outside the house (Experiment 1A) and a smaller or larger than a loaf of bread (Experiment 2A) classification task, objects with earlier-acquired names were categorized more quickly than those with later-acquired names. Experiments 1B and 2B also showed AoA effects on object-naming times for the same pictures. We conclude that AoA operates within the identification process in a fashion not simply restricted to name retrieval. These effects may be better explained in terms of the connectionist model proposed by Ellis and Lambon Ralph (2000) or by accounts that locate AoA within the semantic system (e.g., Brysbaert, Van Wijnendaele, & De Deyne, 2000; van Loon-Vervoorn, 1989).

Adolescent↗

PubMed2004

Correlation between gene expression and morphological alterations in baboon carotid after balloon dilatation injury.

Treatment for fibroproliferative restenosis after angioplasty and endovascular surgery is an unmet medical need. Rational therapy and drug design still lack the very basic knowledge about the underlying biological processes leading to pathological changes in the vessel wall. We have developed a primate model for vascular response to denudation-overstretch injury of baboon carotid artery. With this model, we have investigated the time course of vascular expression of 41,000 human cDNA clones and correlated these changes with carotid histology and function. Analysis revealed 20,788 differentially regulated cDNA clones. After high stringency data selection, the most prominently regulated 1629 cDNA clones representing 1510 genes of known function were clustered. Genes corresponding to functional and anatomical alterations in the injured carotid wall were further aligned into functional groups according to Gene Ontology classification. The observed expression patterns faithfully reflected the functional and anatomical alterations observed in the vascular wall in response to injury. The analysis presents a tentative model for genomic response to balloon catheter injury and a road map to identify time-related genomic alterations in human vascular specimens.

Animals↗

PubMed2003

Both concreteness and age-of-acquisition affect reading accuracy but only concreteness affects comprehension in a deep dyslexic patient.

As concreteness correlates very highly with the age-of-acquisition (AoA) of words, we attempted to disentangle the effects of these two variables in the oral reading and comprehension performance of the deep dyslexic patient LW. The results of a multiple regression analysis of LW's reading of 217 words showed that both AoA and concreteness affect reading accuracy, with the AoA effect being most apparent for her reading of concrete words. However, concreteness and not AoA affected LW's performance in matching spoken definitions to printed words, both when the distractors were semantically unrelated and when they were related. These data are interpreted in terms of a model of reading in deep dyslexia in which concreteness affects the ease with which semantics are accessed and can activate lexical representations, and AoA affects the ease with which lexical phonology becomes available for spoken word production.

Age Factors↗

PubMed2003

Molecular profiling of anemia in acute renal allograft rejection using DNA microarrays.

Compromised renal function after renal allograft transplantation often results in anemia in the recipient. Molecular mechanisms leading to anemia during acute rejection are not fully understood; inadequate erythropoietin production and iron deficiency have been reported to be the main contributors. To increase our understanding of the molecular events underlying anemia in acute rejection, we analyzed the gene expression profiles of peripheral blood lymphocytes (PBL) from four pediatric renal allograft recipients with acute rejection and concurrent anemia, using DNA microarrays containing 9000 human cDNA clones (representing 7469 unique genes). In these anemic rejecting patients, an 'erythropoiesis cluster' of 11 down-regulated genes was identified, involved in hemoglobin transcription and synthesis, iron and folate binding and transport. Additionally, some alloimmune response genes were simultaneously down-regulated. An independent data set of 36 PBL samples, some with acute rejection and some with concurrence of acute rejection and anemia, were analyzed to support a possible association between acute rejection and anemia. In conclusion, analysis using DNA microarrays has identified a cluster of genes related to hemoglobin synthesis and/or erythropoeisis that was altered in kidneys with renal allograft rejection compared with normal kidneys. The possible relationship between alterations in the expression of this cluster, reduced renal function, the alloimmune process itself, and other influences on the renal transplant awaits further analysis.

5-Aminolevulinate Synthetase↗

PubMed2003

In vitro biomechanical comparison of pedicle screws, sublaminar hooks, and sublaminar cables.

OBJECT: Three types of posterior thoracolumbar implants are in use today: pedicle screws, sublaminar titaniumcables, and sublaminar hooks. The authors conducted a biomechanical comparison of these three implants in human cadaveric spines. METHODS: Spine specimens (T5-12) were harvested, radiographically assessed for fractures or metastases, and their bone mineral density (BMD) was measured. Individual vertebrae were disarticulated and fitted with either pedicle screws, sublaminar cables, or bilateral claw hooks. The longitudinal component of each construct consisted of bilateral 10-cm rods connected with two cross-connectors. The vertebral body was embedded in cement, and the rods were affixed to a ball-and-socket apparatus for the application of a distraction force. The authors analyzed 1) 20 vertebrae implanted with screws; 2) 20 with hooks, and 3) 20 with cables. The maximum pullout (MPO) forces prior to failure (mean +/- standard deviation) for the screw, hook, and cable implants were 972 +/- 330, 802 +/- 356, and 654 +/- 248 N, respectively (p = 0.0375). Cables allowed significantly greater displacement (6.80 +/- 3.95 mm) prior to reaching the MPO force than hooks (3.73 +/- 1.42 mm) and screws (4.42 +/- 2.15 mm [p = 0.0108]). Eleven screw-implanted vertebrae failed because of screw pullout. All hook-and-cable-implanted vertebrae failed because of pedicle, middle column, or laminar fracture. CONCLUSIONS: These findings suggest that screws possess the greatest pullout strength of the three fixation systems. Sublaminar cables are the least rigid of the three. When screw failure occurred, the mechanism was generally screw back-out, without vertebral fractures.

Adult↗

PubMed2002

Gene expression patterns in human liver cancers.

Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Using cDNA microarrays to characterize patterns of gene expression in HCC, we found consistent differences between the expression patterns in HCC compared with those seen in nontumor liver tissues. The expression patterns in HCC were also readily distinguished from those associated with tumors metastatic to liver. The global gene expression patterns intrinsic to each tumor were sufficiently distinctive that multiple tumor nodules from the same patient could usually be recognized and distinguished from all the others in the large sample set on the basis of their gene expression patterns alone. The distinctive gene expression patterns are characteristic of the tumors and not the patient; the expression programs seen in clonally independent tumor nodules in the same patient were no more similar than those in tumors from different patients. Moreover, clonally related tumor masses that showed distinct expression profiles were also distinguished by genotypic differences. Some features of the gene expression patterns were associated with specific phenotypic and genotypic characteristics of the tumors, including growth rate, vascular invasion, and p53 overexpression.

Carcinoma, Hepatocellular↗

PubMed2002

A retrospective cohort study comparing microwave endometrial ablation with levonorgestrel-releasing intrauterine device in the management of heavy menstrual bleeding.

OBJECTIVE: To compare microwave endometrial ablation (MEA) with a levonorgestrel-releasing intrauterine device (Mirena) in the management of heavy menstrual bleeding. DESIGN: A retrospective cohort study SAMPLE: Thirty-nine women were treated with MEA and 23 women with Mirena, in the South East Regional Health Service of South Australia during 1998 to 2001; the mean duration of follow-up was 14.6 months. MAIN OUTCOME MEASURES: Primary measures included acceptability of the treatment process, effectiveness of the treatment, and satisfaction with outcomes. Secondary measures included side effects, complications and quality of life (using the SF-36). RESULTS: Acceptability of the treatment process and satisfaction with outcomes was very high for both procedures. Each treatment led to a statistically significant reduction in menstrual bleeding (p < 0.0001) and dysmenorrhoea scores (p < 0.002). CONCLUSIONS: There were no statistical differences between the two treatments for any of the primary or secondary outcome measures assessed. The treatments seem equally effective in the management of heavy menstrual loss.

Adult↗