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Biomedical subjects

John Wright

Publications and source records attributed to John Wright.

At least 73 records · Page 4Linked to original sources
PubMed2003

Concentric intermediate filament lattice links to specialized Z-band junctional complexes in sonic muscle fibers of the type I male midshipman fish.

Type I male midshipman fish produce high-frequency hums for prolonged durations using sonic muscle fibers, each of which contains a hollow tube of radially oriented thin and flat myofibrils that display extraordinarily wide ( approximately 1.2 microm) Z bands. We have revealed an elaborate cytoskeletal network of desmin filaments associated with the contractile cylinder that form interconnected concentric ring structures in the core and periphery at the level of the Z bands. Stretch and release of single fibers revealed reversible length changes in the elastic desmin lattice. This lattice is linked to Z bands via novel intracellular desmosome-like junctional complexes that collectively form a ring, termed the "Z corset," around the periphery and within the core of the cylinder. The junctional complex consists of regularly spaced parallel approximately 900-nm-long cytoskeletal rods, or "Z bars," interconnected with slender (3-4 nm) plectin-positive filaments. Z bars are linked to the Z band by plectin filaments and on the opposite side to a dense mesh of desmin filaments. Adjacent Z bands are linked by slender filaments that appear to suspend sarcotubules. We propose that the highly reinforced elastic desmin cytoskeleton and the unique Z band junctions are structural adaptations that enable the muscles' high-frequency and high-endurance activity.

Animals↗
PubMed2003

Effectiveness of clinical pathways for total knee and total hip arthroplasty: literature review.

Although many hospitals have implemented clinical pathways to standardize the process of care, the effectiveness of clinical pathways for total hip and knee arthroplasties has not been reviewed critically. We searched for articles comparing outcomes of total hip or knee arthroplasty for patients who were treated using clinical pathways as opposed to patients treated without these pathways. Eleven studies met criteria for inclusion. Ten used historical controls, and 1 was a randomized trial. The studies had important methodological limitations. In general, the articles showed that patients treated using pathways experienced shorter hospital stays and lower costs, with comparable clinical outcomes as compared with patients treated without clinical pathways. We concluded that clinical pathways appear successful in reducing costs and length of stay in the acute care hospital, with no compromise in patient outcomes. However, interpretation of these studies is complicated by substantial methodological limitations, particularly the use of historical controls and failure to account for length of stay in rehabilitation facilities.

Arthroplasty, Replacement, Hip↗
PubMed2003

Access to diabetes services: the experiences of Bangladeshi people in Bradford, UK.

Recent years have seen a renewed emphasis in UK healthcare policy on access to services, yet there has been little research into possible inequalities in access for people from different ethnic backgrounds. This paper examines access from the point of view of a group of Bangladeshi people with diabetes, whose views were obtained as part of a wider evaluation of diabetes services. Their message is a powerful one. The problems they experienced, however, cannot be attributed solely to cultural insensitivity, in which providers adopt a 'like it or lump it' approach. The wider evaluation provides a context within which to identify similarities with, as well as differences from, other groups in the community, and the findings show that the experiences of this vulnerable group highlight more general weaknesses in service provision. The paper also shows that conventional analysis of access in terms of barriers to be overcome misses a crucial dimension: the ability to make full use of services. Gaining access does not mean that needs will be met appropriately, and patients vary in the extent to which they are able and enabled to play an active role in obtaining the services they need.

Adult↗
PubMed2003

Anatomy, pathologic features, and treatment of acetabular labral tears.

There is an evolving body of knowledge regarding the acetabular labrum. Labral tears are most frequently anterior and often are associated with sudden twisting or pivoting motions. High clinical suspicion in association with positive physical findings are fundamental for the clinician to properly determine treatment for the suspected tear. Labral tears, especially those present for years, may contribute to the progression of hip osteoarthritis. Patients at risk include those with developmental dysplasia, those with tears greater than 5 years, and those with associated chondral full-thickness lesions. Chondral injuries may occur in association with a multitude of hip conditions including labral tears, loose bodies, osteonecrosis, slipped capital femoral epiphysis, dysplasia, and degenerative arthritis. Labral tears occurring at the watershed zone may destabilize the adjacent acetabular conditions. Arthroscopic observations support the concept that labral disruption, acetabular chondral lesions, or both frequently are part of a continuum of degenerative joint disease.

Acetabulum↗
PubMed2003

Sexual behavior problems in preteen children: developmental, ecological, and behavioral correlates.

A large sample of 2-12 year old children (N = 2311) was studied to determine the relationship between three sexually intrusive behavior items (SIBs) measured by the Child Sexual Behavior Inventory (CSBI) and a range of developmental, ecological, and behavioral correlates. The variables studied included age, gender, race, family income, single parent status, maternal education, family sexual behaviors, physical abuse, sexual abuse, domestic violence, social competence of the child, and three scales from the CBCL (Internalizing, Externalizing, and PTSD). Sexual abuse was not the primary predictor of SIB, but a model incorporating family adversity, modeling of coercive behavior, child behavior, and modeling of sexuality predicted a significant amount of variance.

Child↗
PubMed2003

Effectiveness of multifaceted implementation of guidelines in primary care.

OBJECTIVE: To evaluate the effectiveness of a tailored and multifaceted approach to the implementation of nationally recommended and evidence-based guidelines in primary care within existing systems and resources. METHODS: A non-randomised Latin square to compare guideline implementation in two neighbouring health districts covering 180 general practices. Evidence-based guidelines for the treatment of patients with asthma and angina were implemented actively in one district and passively disseminated in the other district. Outcome measures for asthma were smoking status and inhaler technique. For angina the outcome measures were: smoking status; blood pressure; aspirin prescribed, contraindicated or self-medicated; beta-blocker prescribed or contraindicated; routine hospital admission; prescribed drugs; self-reported change. RESULTS: There were improvements in all outcome criteria between baseline and follow-up audits, regardless of whether the guideline was actively implemented or passively disseminated. The estimated increase in the proportion of records complying with guidelines was 4% [95% confidence intervals (CI): 0, 8] and was higher in intervention than in control practices. Using only records not compliant at baseline, the corresponding difference was 15% (95% CI: 7, 24). The only significant improvement associated with active implementation was smoking status in angina patients. Both prescribing and hospital admission monthly totals changed during the period of the trial, but there was no significant difference between the pattern of changes in intervention and control districts. A significantly greater proportion of health professionals saw the intervention guideline compared with the control (75% versus 25%). There was a significant correlation between self-reported change and interventions steps (P < 0.05). CONCLUSIONS: Increases in quality markers occurred irrespective of the multifaceted implementation efforts. Some of this increase was due to the method of data collection. Nevertheless, national initiatives may have more influence than local implementation initiatives.

Adrenergic beta-Antagonists↗
PubMed2003

General practitioners' uptake of clinical practice guidelines: a qualitative study.

OBJECTIVE: To explain recent rapid audited change in the uptake of locally implemented, evidence-based clinical guidelines for asthma and angina in primary care. METHODS: A case study of primary care in two matched, adjacent districts in Northern England, focusing on a stratified random sample of 49 general practitioners (GPs) from eight primary care groups. Data were collected from three cycles of mainly qualitative interviews carried out at six-monthly intervals, before and after the dissemination of local guidelines and after audit data were gathered. Interviews examined attitudes, awareness and impact of locally disseminated asthma and angina guidelines and the subsequent audit. Audit data on guideline uptake were also available from a parallel study. RESULTS: The rapid increase in guideline uptake observed in both intervention and control groups was not explained by individual practitioners or practice factors. The findings are attributed to GPs' awareness of policies for evidence-based medicine, of new health service institutions and of the clinical governance activities of primary care groups. Behaviour change reflects GPs' decisions about what to record in case notes as well as their clinical decisions, so that findings may reflect changing perceptions about accountability rather than about preferred treatment regimes. CONCLUSIONS: Guideline production and dissemination is best seen in the broader context of policy change. Studies of guideline implementation should report before and after data and incorporate significant qualitative components in order to identify important contextual factors.

Angina Pectoris↗
PubMed2003

Predictors of maternal support: the point of view of adolescent victims of sexual abuse and their mothers.

Maternal support received by sexual abuse victims is considered a key factor in coping with the aftermath of abuse. The present study looked at four groups of potential predictors of maternal support: mothers' psychosocial characteristics, abuse characteristics, victim's characteristics, and disclosure characteristics. A total of 120 adolescents aged 12 to 17 years and their mothers, who were recruited from Child Protective Services, completed questionnaires and semi-structured interviews. Multiple regression analyses performed separately on mother and child data sets revealed five significant predictors of maternal support in each analysis, four of which were common to both. The discussion underscores the importance of taking into account both the mother's and the victim's perceptions regarding psychological adjustment and family environment.

Adolescent↗
PubMed2003

Sexual at-risk behaviors of sexually abused adolescent girls.

The present study investigated sexual at-risk behaviors of sexually abused adolescent girls. Variables of interest were presence of consensual sexual activity, age at first consensual intercourse, number of sexual partners, condom use, and pregnancies. Participants were 125 sexually abused adolescent girls aged 12 to 17 years. Results showed that severity of sexual abuse (e.g., penetration, multiple perpetrators, physical coercion, multiple incidents of abuse) was related to a greater number of sexual at-risk behaviors. For instance, adolescents with a history of sexual abuse involving penetration were 13 times as likely to have been pregnant. Although family characteristics were significantly associated with being sexually active, their effect proved non-significant in the final hierarchical regression. Regression analyses clearly showed that the likelihood of engaging in sexual at-risk behaviors increased as a function of the number of severity factors.

Adolescent↗
PubMed2003

The relationship between attachment strategies and psychopathology in adolescence.

AIM: The majority of research investigating attachment and psychopathology has focused largely on children, and more recently adults. By comparison, few studies have considered the role of attachment on the development of psychopathology during adolescence. The scarcity of studies in this area is surprising given that adolescence is a critical period of psychological adjustment. This study investigates attachment patterns in adolescence and their relationship to symptomatology and interpersonal difficulties. METHOD: A two-sample comparative design was employed so that a clinical group of adolescents were compared with a matched non-clinical group, on attachment classifications (using a modified Separation Anxiety Test), reported interpersonal difficulties and clinical symptoms. RESULTS: Significant differences were found between the clinical and non-clinical groups on attachment classifications. Adolescents with ambivalent attachment patterns reported significantly more interpersonal difficulties and symptoms compared to young people classified as having secure and avoidant attachment classifications. The results are suggestive of specific differences in the way difficulties are reported. CONCLUSION: The findings are consistent with two strategies of affect regulation. It is proposed that a 'hyperactivating' strategy and a 'deactivating' strategy may be operating among those adolescents with ambivalent and avoidant attachment classifications, respectively. The implications of using self-report measures in clinical work and for evidence-based practice are discussed.

Adolescent↗
PubMed2003

[Contextual factors associated with the symptoms of teenagers victims of intrafamilial sexual aggression].

OBJECTIVE: The aim of the study was to identify the unique contribution of three sets of contextual factors (maternal supports, family problems and characteristics of the sexual aggression) on adolescents' post-disclosure symptoms. All participants were abused by a family member. METHOD: A total of 71 adolescents girls were recruited from youth center services across Quebec. Psychological distress was evaluated with "Trauma Symptoms Checklist for Children" (TSC-C; Briere, 1989). Adolescents also completed self-report instruments and semi-structured interviews to evaluate contextual factors. RESULTS: Regression analyses indicated that general maternal support explain more variance in most of TSC-C symptoms than maternal response to disclosure. Analysis highlight that alcohol problems in family and various characteristics of sexual aggression explain a unique part of variance of several symptoms. CONCLUSIONS: The discussion addresses the need to continue to explore these questions with more specific instruments to evaluate family problems. A large spectrum of symptoms should also be considered.

Adolescent↗
PubMed2002

Ethnic divergence and linkage disequilibrium of novel SNPs in the human NLI-IF gene: evidence of human origin and lack of association with tuberculosis susceptibility.

Sequence variation in the human genome has been used as a tool in studying human diseases and the evolutionary history of man. A human inherited predisposition to tuberculosis has been suggested and studied; however. genetic mechanisms are still ambiguous. In the present study, we scanned the regulatory and coding region of Nuclear LIM Interactor-Interacting Factor gene (NLI-IF), which is physically close to the tuberculosis-associated gene NRAMP1. Thirteen biallelic single-nucleotide polymorphisms (SNPs) were identified from four ethnic populations (African-American, Caucasian, Hispanic, and Asian) with population-specific distribution of alleles. The extent of linkage disequilibrium (LD) between 402T > C, and 472-42G > A varied distinctly from complete LD in the non-African-American groups to strong but incomplete LD in African-Americans. Both SNPs were in significant LD with the polymorphism 3' UTR in NRAMP1 among these ethnic groups (P < 0.02), except 402T > C in African-Americans. In a case-control study with a Caucasian population, three cosmopolitan SNPs (204C > A, 402T > C and 472 - 42G > A) in NLI-IF showed no significant association with human susceptibility to tuberculosis. Our results support the "out-of-Africa" model of human origin, and suggest the time for the common ancestor dispersing from Africa could not have been more than approximately 385,620 years ago.

Alleles↗
PubMed2002

Intrafamilial sexual abuse: brother-sister incest does not differ from father-daughter and stepfather-stepdaughter incest.

OBJECTIVE: Three groups of girls who were sexually abused (by either brothers, fathers, or stepfathers) were compared. The purpose was to identify the differing characteristics of the abuse, the family environments, and the psychosocial distress of these children. METHOD: Seventy-two girls aged between 5 and 16 were assigned to one of the three groups. Subjects were matched between groups on the basis of their actual age. Children completed measures of traumatic stress; their mothers completed the Child Behavior Checklist-Parent Report Form (CBCL) and other self-report questionnaires on family characteristics. Workers in child protective services completed information regarding the nature and severity of the abuse. RESULTS: Results suggested few differences in the characteristics of sexual abuse between the three groups. However, penetration was much more frequent in the sibling incest group (70.8%) than in the stepfather incest (27.3%) or father incest (34.8%) groups. Ninety percent of the victims of fathers and brothers manifested clinically-significant distress on at least one measure, whereas 63.6% of stepfather victims did. Compared with father and stepfather perpetrators, brothers were raised in families with more children and more alcohol abuse. CONCLUSIONS: The authors conclude that the characteristics of brother-sister incest and its associated psychosocial distress did not differ from the characteristics of father-daughter incest These findings suggest that theoretical models and clinical practices should be adjusted accordingly and that sibling incest should not necessarily be construed as less severe or harmful than father-daughter incest.

Adolescent↗
PubMed2002

The early days of primary care groups: general practitioners' perceptions.

English primary care is currently undergoing radical reform. Primary care groups (PCGs), effectively compulsory federations of general practices, came into legal existence in April 1999. This paper contains a review of general practitioners' (GPs') initial perceptions of the impact of these reforms on practice and considers the wider issue of changes in professional autonomy. A random sample of 49 GPs from two adjacent health districts in the North of England were interviewed as part of a longitudinal qualitative study. One round of interviews took place 7 to 9 months after the creation of PCGs and a further round of interviews was carried out 6 months later. We were interested in GPs' knowledge of recently formed (PCGs') plans and priorities, the impact of PCG activity to date, and the predicted future impact of such activity. After the published priorities of PCGs had been identified, thematic content analysis was used to ascertain GPs' perceptions of those priorities. GPs were generally unaware of their PCGs' published priorities. The wider strategic role of PCGs in commissioning services was rarely alluded to. Although over a third of GPs reported no current impact of the PCG, the majority expected PCGs to have considerable impact. In particular, control, management and accountability arrangements were all perceived as central issues in the expected developments. Performance management arrangements related to specific clinical priorities were widely expected. Although the new arrangements were inspiring little enthusiasm, the reforms did not appear to threaten GPs sufficiently enough to provoke active resistance.

Attitude of Health Personnel↗