[Translated article] Evolution of chromium and cobalt serum levels after the use of a modular neck stem in primary total hip arthroplasty.

INTRODUCTION AND OBJECTIVES: Modular neck primary stems were introduced with the theoretical advantage of restoring the hip anatomy more precisely. However, the presence of a second junction has been associated with increased corrosion and release of metal debris. The objective of our study is to quantify of chromium and cobalt serum values, and to analyse their temporal evolution during five years. MATERIAL AND METHODS: We present a prospective series of 61 patients who underwent primary total hip arthroplasty by implantation of the H MAX-M® stem (Limacorporate, San Daniele, Italy). Serum chromium and cobalt determinations were performed at six months, two years and five years. RESULTS: Our series shows a progressive elevation in chromium levels with a significant difference between chromium values at six months (0.35±0.18) and five years (0.52±0.36), p=.01. Regarding cobalt, a statistically significant elevation is observed between six months and two years and a subsequent stabilisation of values between two and five years, with a cobalt mean at six months (1.17±0.8) significantly lower than at two (2.63±1.76) and five years (2.84±2.1), p=.001. CONCLUSION: Elevated serum cobalt levels have been observed in patients who underwent modular neck stem implantation. The results obtained in this study have limited the use of stems with a modular neck in our clinical practice.

Evolution of chromium and cobalt serum levels after the use of a modular neck stem in primary total hip arthroplasty. / Evolución de los niveles séricos de cromo y cobalto tras el empleo de un vástago con cuello modular en la artroplastia total de cadera primaria.

INTRODUCTION AND OBJECTIVES: Modular neck primary stems were introduced with the theoretical advantage of restoring the hip anatomy more precisely. However, the presence of a second junction has been associated with increased corrosion and release of metal debris. The objective of our study is to quantify of chromium and cobalt serum values, and to analyze their temporal evolution during five years. MATERIAL AND METHODS: We present a prospective series of 61 patients who underwent primary total hip arthroplasty by implantation of the HMAX-M® stem (Limacorporate, San Daniele, Italy). Serum chromium and cobalt determinations were performed at six months, two years and five years. RESULTS: Our series shows a progressive elevation in chromium levels with a significant difference between chromium values at six months (0.35±0.18) and five years (0.52±0.36), P=.01. Regarding cobalt, a statistically significant elevation is observed between six months and two years and a subsequent stabilization of values between two and five years, with a cobalt mean at six months (1.17±0.8) significantly lower than at two (2.63±1.76) and five years (2.84±2.1), P=.001. CONCLUSION: Elevated serum cobalt levels have been observed in patients who underwent modular neck stem implantation. The results obtained in this study have limited the use of stems with a modular neck in our clinical practice.

Comparison of chromium and cobalt serum levels between a modular neck stem and its monoblock counterpart in primary total hip arthroplasty.

BACKGROUND: The addition of junctions in modular stems implies a greater susceptibility to corrosion. PURPOSE: The aim of this study is to compare serum chromium and cobalt levels after using a bimodular stem and its monoblock counterpart in primary total hip arthroplasty. Postoperative clinical scores were also compared. PATIENTS AND METHODS: A prospective cohort study between 2012 and 2015 was designed. One arm of the cohort included patients with the cementless modular neck stem H-Max M® and the other with the cementless monoblock stem counterpart H-Max S®. RESULTS: No statistically significant difference was found in chromium value between groups (p = 0.621) at two years postoperative. Cobalt value was higher in the modular group (p = < 0.001). No statistically significant difference was found in clinical postoperative scores except for the Harris Hip Score, with better results at six months in modular group (p = 0.007). CONCLUSIONS: Higher serum cobalt level in the modular group has limited the use of modular stems in our daily practice. Advantages of modular stem were not found. LEVEL OF EVIDENCE: II.

[Translated article] Comparison of leg length discrepancy correction after the use of a modular neck stem and its monoblock homologue in total primary hip arthroplasty.

INTRODUCTION AND OBJECTIVE: Dual modularity stems seek to more precisely restore anatomy by allowing intraoperative adjustments thanks to modular necks. Our aim is to compare the radiographic length correction with the H MAX-M® Stem versus its monoblock counterpart H MAX-S®. MATERIAL AND METHODS: A prospective cohort study was carried out through consecutive sampling on patients who underwent primary total hip arthroplasty with coxarthrosis diagnosis between 2011 and 2015. One arm of the cohort included patients who were operated with a modular stem and the other with a monobloc stem. Length was measured on the anteroposterior pelvic-bearing radiograph at 6 months. The mean of the measurements obtained for each arm of the cohort were compared with each other. RESULTS: No statistically significant differences were observed in the correction of asymmetry between both groups, determined as the difference in length between the operated hip and the contralateral hip (p=.106). Nor were differences observed in postoperative length values (p=.053). It should be noted that for both the modular stem and the monobloc stem, the majority group is the one with restored length (84.1% and 80.4%, respectively; p=.001). CONCLUSION: Despite the theoretical advantage of modularity and that having interchangeable parts could be of great interest, in our study, we have not been able to demonstrate a superiority of modular designs compared to monoblock for control of postoperative leg length discrepancy.

Comparison of leg length discrepancy correction after the use of a modular neck stem and its monoblock homologue in total primary hip arthroplasty. / Comparación de la corrección de la discrepancia de longitud de miembros tras el empleo de un vástago con cuello modular y su homólogo monobloque en la artroplastia total de cadera primaria.

INTRODUCTION AND OBJECTIVE: Dual modularity stems seek to more precisely restore anatomy by allowing intraoperative adjustments thanks to modular necks. Our aim is to compare the radiographic length correction with the H MAX-M® Stem versus its monoblock counterpart H MAX-S®. MATERIAL AND METHODS: A prospective cohort study was carried out through consecutive sampling on patients who underwent primary total hip arthroplasty with coxarthrosis diagnosis between 2011 and 2015. One arm of the cohort included patients who were operated with a modular stem and the other with a monobloc stem. Length was measured on the anteroposterior pelvic-bearing radiograph at six months. The mean of the measurements obtained for each arm of the cohort were compared with each other. RESULTS: No statistically significant differences were observed in the correction of asymmetry between both groups, determined as the difference in length between the operated hip and the contralateral hip (P=.106). Nor were differences observed in postoperative length values (P=.053). It should be noted that for both the modular stem and the monobloc stem, the majority group is the one with restored length (84.1% and 80.4%, respectively; P=.001). CONCLUSION: Despite the theoretical advantage of modularity and that having interchangeable parts could be of great interest, in our study, we have not been able to demonstrate a superiority of modular designs compared to monoblock for control of postoperative leg length discrepancy.

Comparison of the correction of the femoral offset after the use of a stem with modular neck and its monoblock homologue in total primary hip arthroplasty. / Comparación de la corrección del offset femoral tras el empleo de un vástago monobloque y un vástago con cuello modular en la artroplastia total de cadera primaria.

INTRODUCTION AND OBJECTIVE: Dual modularity stems were introduced with the theoretical advantage of restoring hip anatomy more precisely through femoral offset and limb length adjustment. Interchangeable necks allow for intraoperative angulation, anteversion and length changes. Our objective is to study whether a better femoral offset correction is achieved with the H MAX-M® prosthesis (Limacorporate, San Daniele, Italy) compared to its monoblock counterpart. MATERIAL AND METHODS: A prospective cohort study was conducted by means of consecutive sampling on adult patients undergoing total hip arthroplasty with the diagnosis of coxarthrosis between January 2011 and December 2015. This cohort has two arms, one arm included patients who underwent modular neck arthroplasty and the other included patients who underwent monoblock total hip arthroplasty. Radiographic offset measurement of the operated hip and the contralateral hip was performed, and the difference between both values was calculated. The mean of the measurements obtained for each arm of the cohort were compared with each other. RESULTS: No statistically significant differences were observed in the difference in offset between the operated hip and the contralateral hip (P=.323). No statistically significant differences were observed in the correction of the femoral offset, determined as the difference between the operated hip and the contralateral hip (P=.323). Nor were differences observed in the postoperative offset values (P=.097). It should be noted that for both designs, the majority group is the one with restored offset (P=.001).

M1 and M2 mAChRs activate PDK1 and regulate PKC ßI and ε and the exocytotic apparatus at the NMJ.

Neuromuscular junctions (NMJ) regulate cholinergic exocytosis through the M1 and M2 muscarinic acetylcholine autoreceptors (mAChR), involving the crosstalk between receptors and downstream pathways. Protein kinase C (PKC) regulates neurotransmission but how it associates with the mAChRs remains unknown. Here, we investigate whether mAChRs recruit the classical PKCßI and the novel PKCε isoforms and modulate their priming by PDK1, translocation and activity on neurosecretion targets. We show that each M1 and M2 mAChR activates the master kinase PDK1 and promotes a particular priming of the presynaptic PKCßI and ε isoforms. M1 recruits both primed-PKCs to the membrane and promotes Munc18-1, SNAP-25, and MARCKS phosphorylation. In contrast, M2 downregulates PKCε through a PKA-dependent pathway, which inhibits Munc18-1 synthesis and PKC phosphorylation. In summary, our results discover a co-dependent balance between muscarinic autoreceptors which orchestrates the presynaptic PKC and their action on ACh release SNARE-SM mechanism. Altogether, this molecular signaling explains previous functional studies at the NMJ and guide toward potential therapeutic targets.

Which route of administration of acid tranexamic, intravenous or intra-articular, is more effective in the control of post-surgical bleeding after a total hip arthroplasty? A prospective, controlled and randomized study. / Aplicación del tranexámico intravenoso o intraarticular en el control del sangrado posquirúrgico tras una artroplastia total de cadera. Estudio prospectivo, controlado y aleatorizado.

INTRODUCTION: One of the most frequent complications after a total hip arthroplasty (THA) is bleeding, intravenous tranexamic acid (TXA) is used to reduce it. We considered it necessary to carry out a study to clarify which administration route is superior. MATERIAL AND METHOD: Prospective, controlled and randomized study in 2 arms carried out between February 2017 and February 2018. 15mg/kg of intravenous TXA were administered in group-A and 2gr of intra-articular TXA in group-B. The values of haemoglobin and haematocrit were evaluated at 24h-72h, blood loss volume, drained blood volume, transfusions and complications. RESULTS: 78 patients were included, 31 with intravenous treatment and 47 with intra-articular. The decrease of haemoglobin in the intravenous group was 3.15±1.64g/dl in 24h and 3.75±1.56g/dl in 72h, the haematocrit decreased by 10.4±4.17% in 24h and 11.85±4.15% in 72h. In the intra-articular group there was a haemoglobin fall of 3.03±1.30g/dl in 24h and 3.22±1.2g/dl in 72h and the haematocrit fell by 10.66±3.6% and 12,11±3.29% in 24 and 72h (P>.05). The mean drainage in 24h was 195.80ml in group-A versus 253.93ml in group-B (P>.05) and in 48h it was 225.33ml in group-A and 328.19ml in group-B (P=.009). The intravenous group lost an average of 1,505ml of blood compared to the 11,280ml of the intra-articular group. In 5.1% of the cases, transfusions were necessary. We had no secondary complications. CONCLUSIONS: The different routes of administration of TXA in THA have a similar effect in the reduction of postoperative bleeding. There was no evidence of an increase in complications.

Primary total hip arthroplasty with fourth-generation ceramic bearings: Clinical and survival results with a minimum follow-up of 5 years. / Prótesis total de cadera primaria con par de fricción cerámica sobre cerámica de cuarta generación: resultados clínicos y de supervivencia con un seguimiento mínimo de 5 años.

OBJECTIVE: To evaluate the clinical results and survival of primary hip prosthesis with ceramic delta bearings (C-C) with a minimum follow-up of 5years. MATERIAL AND METHOD: A total of 205 primary hip arthroplasties performed between 2008 and 2012 were studied. The clinical results, pre-surgical and at 5years of follow-up were evaluated using the Harris Hip Score (HHS), the Short Form-36 (SF-36), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the visual analogue scale (VAS). The position of the prosthetic components, periprosthetic osteolysis, loosening of the prosthetic components and ruptures of the ceramic components were studied radiologically. The adverse events related to bearings were recorded according to their diameter, paying special attention to prosthetic dislocations and the presence of noise. Survival with an endpoint of prosthetic revision for any cause was estimated using the Kaplan-Meier method. RESULTS: Significant improvements were obtained in the HHS (88.7% of good/excellent results), SF36, WOMAC and EVA, P<.001. There were 19 adverse events related to the prosthesis (4 periprosthetic fractures, 4 dislocations, 2 superficial infections, 1 mobilization of the cup, 2 noises, 4 aseptic loosenings and 2 breaks of the prosthetic neck); 47.3% needed revision. The cumulative survival of the prostheses was 97.5% (95%CI: 96.4-98.5). No differences were found in survival, prosthetic adverse events, noise incidence or dislocations and clinical results among the different diameters used. CONCLUSIONS: Primary hip prostheses with fourth-generation ceramic bearings showed good survival in the medium term, and good clinical results.

Development and validation of the openness to the future scale: a prospective protective factor.

BACKGROUND: Most of the research on psychopathology has provided an incomplete picture of mental health by focusing on vulnerability factors and omitting the transversal processes that may explain human adapted functioning. Moreover, research has not sufficiently addressed prospective protective factors for mental health. New theoretical and empirical endeavors aim to incorporate this perspective, particularly in the realm of emotional disorders. A positive view of the future is an indispensable process in attaining desired goals and wellbeing. Openness to the Future is a construct characterized by positive affectivity towards the future, which can be a protective factor for mental health. Although some scales assess future orientations, the complexity of this concept has not yet been captured; therefore, there is a need for new instruments. This study presents the development and validation of a scale for measuring Openness to the Future in clinical (n = 412) and community (n = 890) samples. METHODS: Psychometric properties of the OFS were analyzed using Confirmatory Factor Analysis (CFA) and Item Response Theory (IRT) analyses, establishing cut-off points to better classify these two groups. Moreover, convergent and discriminant validity were examined by correlating the OFS with theoretically related constructs. RESULTS: Results support a unidimensional structure and indicate that the items function similarly across clinical and community samples. Moreover, the Openness to the Future scale shows good convergent and discriminant validity. CONCLUSIONS: These findings suggest that the Openness to the Future scale is a valid and brief measure of openness to the future for use with clinical and community samples, and it could help to fill a gap in the literature regarding attitudes towards the future and their implications. Openness to the Future is presented as an empirically feasible and theoretically consistent construct that includes both prospective and protective factors in the psychopathological chart.

Effects of a Fence on Pollutant Dispersion in a Boundary Layer Exposed to a Rural-to-Urban Transition.

Simultaneous particle-image velocimetry and laser-induced fluorescence combined with large-eddy simulations are used to investigate the flow and pollutant dispersion behaviour in a rural-to-urban roughness transition. The urban roughness is characterized by an array of cubical obstacles in an aligned arrangement. A plane fence is added one obstacle height h upstream of the urban roughness elements, with three different fence heights considered. A smooth-wall turbulent boundary layer with a depth of 10h is used as the approaching flow, and a passive tracer is released from a uniform line source 1h upstream of the fence. A shear layer is formed at the top of the fence, which increases in strength for the higher fence cases, resulting in a deeper internal boundary layer (IBL). It is found that the mean flow for the rural-to-urban transition can be described by means of a mixing-length model provided that the transitional effects are accounted for. The mixing-length formulation for sparse urban canopies, as found in the literature, is extended to take into account the blockage effect in dense canopies. Additionally, the average mean concentration field is found to scale with the IBL depth and the bulk velocity in the IBL.

Dispositional hope and life satisfaction among older adults attending lifelong learning programs.

BACKGROUND: The aim of this study is to explore the indirect effects of dispositional hope in the life satisfaction of older adults attending a lifelong learning program at the University of Valencia, Spain. We examine the mediating impact of dispositional hope regarding its ability to impact life satisfaction while considering affective and confidant social support, perceived health and leisure activities, consciousness and spirituality as predictors. METHODS: Analysis were based on survey data (response rate 77.4%) provided by 737 adults 55 years old or more (Mean age=65.41, SD=6.60; 69% woman). A structural model with latent variables was specified and estimated in Mplus. RESULTS: The results show the ability of just a few variables to sum up a reasonable model to apply to successful aging population. All these variables are correlated and significantly predict hope with the exception of health. The model additionally includes significant positive indirect effects from spirituality, affective support and consciousness on satisfaction. The model has a good fit in terms of both the measurement and structural model. Regarding predictive power, these comprehensive four main areas of successful aging account for 42% of hope and finally for one third of the life satisfaction variance. CONCLUSIONS: Results support the mediating role of dispositional hope on the life satisfaction among older adults attending lifelong learning programs. These findings also support the MacArthur model of successful aging adapted to older adults with high levels of functional, social and cognitive ability. Dispositional hope, perceived health, and social support were the strongest predictors of satisfaction with life.

Cobalt toxicity after revision total hip replacement due to fracture of a ceramic head. / Toxicidad por cobalto después de la revisión a una artroplastia total de cadera posterior a fractura de cabeza cerámica.

Symptomatic cobalt toxicity from a failed total hip replacement is a rare, but devastating complication. Potential clinical findings include cardiomyopathy, hypothyroidism, skin rash, visual and hearing impairment, polycythaemia, weakness, fatigue, cognitive impairment, and neuropathy. The case is presented of a 74year-old man in whom, after a ceramic-ceramic replacement and two episodes of prosthetic dislocation, it was decided to replace it with a polyethylene-metal total hip arthroplasty (THA). At 6months after the revision he developed symptoms of cobalt toxicity, confirmed by analytical determination (serum cobalt level=651.2µg/L). After removal of the prosthesis, the levels of chromium and cobalt in blood and urine returned to normal, with the patient currently being asymptomatic. It is recommended to use a new ceramic on ceramic bearing at revision, in order to minimise the risk of wear-related cobalt toxicity following breakage of ceramic components.

Aeromonas piscicola AH-3 expresses an extracellular collagenase with cytotoxic properties.

UNLABELLED: The aim of this study was to investigate the presence and the phenotypic expression of a gene coding for a putative collagenase. This gene (AHA_0517) was identified in Aeromonas hydrophila ATCC 7966 genome and named colAh. We constructed and characterized an Aeromonas piscicola AH-3::colAh knockout mutant. Collagenolytic activity of the wild-type and mutant strains was determined, demonstrating that colAh encodes for a collagenase. ColAh-collagen interaction was assayed by Far-Western blot, and cytopathic effects were investigated in Vero cells. We demonstrated that ColAh is a gluzincin metallopeptidase (approx. 100 kDa), able to cleave and physically interact with collagen, that contributes for Aeromonas collagenolytic activity and cytotoxicity. ColAh possess the consensus HEXXH sequence and a glutamic acid as the third zinc binding positioned downstream the HEXXH motif, but has low sequence similarity and distinct domain architecture to the well-known clostridial collagenases. In addition, these results highlight the importance of exploring new microbial collagenases that may have significant relevance for the health and biotechnological industries. SIGNIFICANCE AND IMPACT OF THE STUDY: Collagenases play a central role in processes where collagen digestion is needed, for example host invasion by pathogenic micro-organisms. We identified a new collagenase from Aeromonas using an integrated in silico/in vitro strategy. This enzyme is able to bind and cleave collagen, contributes for AH-3 cytotoxicity and shares low similarity with known bacterial collagenases. This is the first report of an enzyme belonging to the gluzincin subfamily of the M9 family of peptidases in Aeromonas. This study increases the current knowledge on collagenolytic enzymes bringing new perspectives for biotechnology/medical purposes.

Method Effects and Gender Invariance of the Rosenberg Self-esteem Scale: A Study on Adolescents / Efectos de Método y Estabilidad entre Sexos de la Escala de Autoestima de Rosenberg: Un Estudio en Adolescentes

Abstract: Rosenberg's self-esteem scale has been extensively used in all areas of psychology to assess global self-esteem (Rosenberg, 1965, 1979). Its construct validity, and specifically its factor structure, has almost from the beginning been under debate. More than four decades after its creation the cumulated evidence points that the scale measures a single trait (self-esteem) but confounded by a method factor associated to negatively worded items. The aim of the study is to examine the measurement invariance of the RSES by gender and test potential gender differences at the latent (trait and method) variable level, while controlling for method effects, in a sample of Spanish students. A series of completely a priori structural models were specified, with a standard invariance routine implemented for male and female samples. The results lead to several conclusions. Conclusions: a) the scale seem gender invariant for both trait and method factors; b) there were small but significant differences between males and females in self-esteem, differences that favored male respondents; and c) there were statistically non-significant differences between men and women in the method factor's latent means.

Resumen: La Escala de Autoestima de Rosenberg (EAR) ha sido utilizada extensamente en todas las áreas de la Psicología para evaluar la autoestima (Rosenberg, 1965, 1979). Su validez de constructo, y particularmente su estructura factorial, ha estado en debate casi desde que fue construida. Más de cuatro décadas después de su creación, la evidencia acumulada señala que la escala evalúa un solo rasgo (autoestima), aunque se confunde con un método factorial asociado de manera negative con reactivos verbales. El objetivo de este estudio fue evaluar la estabilidad de la medición de la EAR entre sexos y poner a prueba potenciales diferencias entre los mismos en un nivel latente de la variable (rasgo y estado), controlando efectos de método, en una muestra de estudiantes españoles. Se especificaron una serie de modelos estructurales a priori, con rutinas implementadas de invarianza estándar para muestras de hombres y mujeres. Los resultados llevan a diferentes conclusiones: a) La escala parece ser invariable ante el sexo tanto para factores de rasgo como de estado; b) existieron diferencias pequeñas, pero significativas, entre hombres y mujeres en autoestima, favoreciendo ligeramente a los hombres; y, c) no existieron diferencias estadísticamente significativas entre hombres y mujeres en las medias de la variable latente del factor.

Predicting life satisfaction of the Angolan elderly: a structural model.

Satisfaction with life is of particular interest in the study of old age well-being because it has arisen as an important component of old age. A considerable amount of research has been done to explain life satisfaction in the elderly, and there is growing empirical evidence on best predictors of life satisfaction. This research evaluates the predictive power of some aging process variables, on Angolan elderly people's life satisfaction, while including perceived health into the model. Data for this research come from a cross-sectional survey of elderly people living in the capital of Angola, Luanda. A total of 1003 Angolan elderly were surveyed on socio-demographic information, perceived health, active engagement, generativity, and life satisfaction. A Multiple Indicators Multiple Causes model was built to test variables' predictive power on life satisfaction. The estimated theoretical model fitted the data well. The main predictors were those related to active engagement with others. Perceived health also had a significant and positive effect on life satisfaction. Several processes together may predict life satisfaction in the elderly population of Angola, and the variance accounted for it is large enough to be considered relevant. The key factor associated to life satisfaction seems to be active engagement with others.

The main Aeromonas pathogenic factors.

The members of the Aeromonas genus are ubiquitous, water-borne bacteria. They have been isolated from marine waters, rivers, lakes, swamps, sediments, chlorine water, water distribution systems, drinking water and residual waters; different types of food, such as meat, fish, seafood, vegetables, and processed foods. Aeromonas strains are predominantly pathogenic to poikilothermic animals, and the mesophilic strains are emerging as important pathogens in humans, causing a variety of extraintestinal and systemic infections as well as gastrointestinal infections. The most commonly described disease caused by Aeromonas is the gastroenteritis; however, no adequate animal model is available to reproduce this illness caused by Aeromonas. The main pathogenic factors associated with Aeromonas are: surface polysaccharides (capsule, lipopolysaccharide, and glucan), S-layers, iron-binding systems, exotoxins and extracellular enzymes, secretion systems, fimbriae and other nonfilamentous adhesins, motility and flagella.

Computed tomographic screening of pulmonary arterial hypertension in candidates for lung transplantation.

INTRODUCTION: Computed tomography (CT) is essential to evaluate candidates for lung transplantation (LT) We sought to correlate identification of pulmonary arterial hypertension (PAH) via CT to echocardiographic (Eco) and/or hemodynamic observations (Hd) as well as the pathological findings (Path) at posttransplant pneumonectomy. MATERIALS AND METHODS: The study included 24 consecutive months follow-up of 71 patients who were referred for LT evaluation with 54 undergoing LT. Study parameters included CT [diameter of the principal pulmonary artery (PPA) >or= 29 mm), PPA/diameter of the ascending aorta (AA) ratio > 1; diameter of the lobar artery (LA)/diameter of the lobar bronchiole (LB) ratio > 1 in three or more lobes; thickening of the anterosuperior pericardial recess (>15 mm); mosaic lung density pattern]; PAPs via Eco and/or Hd, and findings Path of PAH. Statistical analysis included chi-square and Pearson correlation coefficient. RESULTS: Thirty-five patients had PAH. Significant relationships (P < .05) were observed between PAH (Eco and/or Hd) and PPA, PPA/AA, and LA/LB. The sensitivity of the finding PPA >or= 29 mm was 65.9%, and 85.7% when combined with LA/LB > 1. In the Path study, 14/54 patients revealed alterations compatible with PAH. Significant relationships (P < .05) were observed between PAH via Path and PPA (CT) and between PAH via Path and PAH (Eco and/or Hd). CONCLUSIONS: CT is useful for the detection of PAH. Findings of PAH via CT were indicative of the need for further confirmatory studies. In contrast, the absence of findings with CT does not exclude the possible presence of PAH.

Work design and management in the manufacturing sector: development and validation of the Work Organisation Assessment Questionnaire.

OBJECTIVES: To examine the factor structure, reliability, and validity of a new context-specific questionnaire for the assessment of work and organisational factors. The Work Organisation Assessment Questionnaire (WOAQ) was developed as part of a risk assessment and risk reduction methodology for hazards inherent in the design and management of work in the manufacturing sector. METHOD: Two studies were conducted. Data were collected from 524 white- and blue-collar employees from a range of manufacturing companies. Exploratory factor analysis was carried out on 28 items that described the most commonly reported failures of work design and management in companies in the manufacturing sector. Concurrent validity data were also collected. A reliability study was conducted with a further 156 employees. RESULTS: Principal component analysis, with varimax rotation, revealed a strong 28-item, five factor structure. The factors were named: quality of relationships with management, reward and recognition, workload, quality of relationships with colleagues, and quality of physical environment. Analyses also revealed a more general summative factor. Results indicated that the questionnaire has good internal consistency and test-retest reliability and validity. Being associated with poor employee health and changes in health related behaviour, the WOAQ factors are possible hazards. It is argued that the strength of those associations offers some estimation of risk. Feedback from the organisations involved indicated that the WOAQ was easy to use and meaningful for them as part of their risk assessment procedures. CONCLUSIONS: The studies reported here describe a model of the hazards to employee health and health related behaviour inherent in the design and management of work in the manufacturing sector. It offers an instrument for their assessment. The scales derived which form the WOAQ were shown to be reliable, valid, and meaningful to the user population.

Identification and characterization of putative virulence genes and gene clusters in Aeromonas hydrophila PPD134/91.

Aeromonas hydrophila is a gram-negative opportunistic pathogen of animals and humans. The pathogenesis of A. hydrophila is multifactorial. Genomic subtraction and markers of genomic islands (GIs) were used to identify putative virulence genes in A. hydrophila PPD134/91. Two rounds of genomic subtraction led to the identification of 22 unique DNA fragments encoding 19 putative virulence factors and seven new open reading frames, which are commonly present in the eight virulence strains examined. In addition, four GIs were found, including O-antigen, capsule, phage-associated, and type III secretion system (TTSS) gene clusters. These putative virulence genes and gene clusters were positioned on a physical map of A. hydrophila PPD134/91 to determine their genetic organization in this bacterium. Further in vivo study of insertion and deletion mutants showed that the TTSS may be one of the important virulence factors in A. hydrophila pathogenesis. Furthermore, deletions of multiple virulence factors such as S-layer, serine protease, and metalloprotease also increased the 50% lethal dose to the same level as the TTSS mutation (about 1 log) in a blue gourami infection model. This observation sheds light on the multifactorial and concerted nature of pathogenicity in A. hydrophila. The large number of putative virulence genes identified in this study will form the basis for further investigation of this emerging pathogen and help to develop effective vaccines, diagnostics, and novel therapeutics.