The combined measurement of synovial markers in the diagnosis of periprosthetic joint infection.

INTRODUCTION: Currently there is no single test for periprosthetic joint infection (PJI) that demonstrates an acceptable level of sensitivity. The aim of this pilot study was to identify a combination of biomarkers that could exclude periprosthetic infection prior to revision surgery in hip and knee arthroplasty. This would help in equivocal cases of PJI, such as those with low-virulence organisms, chronic low-grade infection or 'aseptic' loosening. Current research has focused on measuring the levels of biomarkers in the patient's synovial fluid, and these can be combined to improve accuracy. METHODS: We selected synovial white cell count (SF-WCC) and C-reactive protein (SF-CRP), as they demonstrated an acceptable level of sensitivity and specificity which could be measured using existing equipment. One hundred and sixty-one synovial fluid samples from 134 patients were collected and analysed prospectively using calculated cut-off values of 10mg/l for SF-CRP and 3,000×106/l for SF-WCC. Samples were deemed positive for infection when either of the SF-CRP or SF-WCC values were above the cut-off. RESULTS: The combined test demonstrated a sensitivity greater than 98.5% and specificity above 80% in all samples analysed or looked at separately for total hip replacement and total knee replacement infections. All ten aspirates taken from chronically infected joints tested positive. CONCLUSIONS: The combination of SF-CRP and SF-WCC measurement has been shown to have high sensitivity of over 99% in detecting both acute and chronic PJI in both hip and knee arthroplasty. This ability of the test to exclude infection with a high degree of certainty will help in preoperative planning of PJIs.

Biosurveillance: a systematic review of global infectious disease surveillance systems from 1900 to 2016.

Biosurveillance is crucial to detect, identify and minimise the negative consequences of infectious disease. Its value to society and importance to global public health and global health security are growing. Despite the long history and global importance of biosurveillance, a systematic review of all existing biosurveillance systems across the 'One Health' spectrum has not yet been published. This study conducted a systematic review to identify all extant and defunct biosurveillance systems from 1900 to 2016. Of the 815 systems examined, the majority surveyed human, animal or plant data discretely. Some 105 collected human and animal data, whereas only 31 collected data on all three categories. The authors found a large increase in the number of global biosurveillance systems between 1900 and 2008, but a reduction in the number of biosurveillance systems from 2008 to the present. The number of syndromic systems created, versus laboratory-based biosurveillance systems, increased rapidly after 1980 across the globe.

La surveillance biologique est un procédé essentiel pour détecter, caractériser et minimiser les effets négatifs des maladies infectieuses. Son rôle à l'égard de la société et son importance pour la santé publique et la sécurité sanitaire mondiale ne cessent de croître. Malgré l'histoire déjà longue et l'importance mondiale de la surveillance biologique, aucun inventaire systématique des systèmes de surveillance biologique mis en œuvre dans une perspective « Une seule santé ¼ n'avait été publié jusqu'à ce jour. La présente étude résume les résultats d'un examen systématique portant sur tous les systèmes de surveillance biologique appliqués entre 1900 et 2016, qu'ils aient été arrêtés ou qu'ils soient encore utilisés aujourd'hui. La majorité des 815 systèmes examinés exploite des données relatives soit aux êtres humains, soit aux animaux, soit aux plantes. Près de 105 systèmes recueillent à la fois des données sur l'être humain et sur les animaux et 31 systèmes seulement recueillent des données sur les trois catégories en même temps. Les auteurs ont constaté une forte augmentation du nombre de systèmes de surveillance biologique dans le monde entre 1900 à 2008, puis un déclin de ce nombre entre 2008 et aujourd'hui. Le nombre de systèmes syndromiques, par opposition aux systèmes de surveillance biologique basés sur les examens de laboratoire a connu une augmentation rapide dans le monde entier à partir de 1980.

La vigilancia biológica (o biovigilancia), indispensable para discernir, detectar y reducir al mínimo las consecuencias negativas de una enfermedad infecciosa, reviste cada vez más interés para la sociedad y más importancia para la salud pública y la seguridad sanitaria mundiales. Pese a la dilatada historia y a la relevancia mundial de la vigilancia biológica, hasta ahora nunca se había publicado un examen sistemático de todos los sistemas de biovigilancia existentes dentro del espectro de «Una sola salud¼. Los autores describen un estudio encaminado a examinar de forma sistemática todos los sistemas de vigilancia biológica, aún vigentes o ya extintos, instaurados entre 1900 y 2016. La mayoría de los 815 sistemas examinados estaban dedicados a la vigilancia específica de las personas, los animales o las plantas. En unos 105 se obtenían datos de humanos y anímales, y solo en 31 de ellos se recogían datos de las tres categorías. Los autores observaron un marcado incremento del número de sistemas mundiales de biovigilancia entre 1900 y 2008, número que en cambio se fue reduciendo a partir de 2008. De 1980 en adelante se aceleró en todo el globo la creación de sistemas sindrómicos, por oposición a sistemas de biovigilancia basados en el trabajo en laboratorio.

The anterior tooth development of cattle presented for slaughter: an analysis of age, sex and breed.

In a cross-sectional study, data from records of cattle slaughtered over a 1-year period at a large abattoir in South West England were analysed using an ordered category response model to investigate the inter-relationships between age, sex and breed on development of the permanent anterior (PA) teeth. Using the model, transition points at which there was a 50% probability of membership of each category of paired PA teeth were identified. Data from ∼60,000 animals were initially analysed for age and sex effect. The age transition was found to be ∼23 months moving from zero to two teeth; 30 months for two to four teeth; 37 months for four to six teeth and 42 months for six to eight teeth. Males were found to develop, on average, ∼22 days earlier than females across all stages. A reduced data set of ∼23,000 animals registered as pure-bred only was used to compare breed and type interactions and to investigate sex effects within the sub-categories. Breeds were grouped into dairy and beef-type and beef breeds split into native and continental. It was found that dairy-types moved through the transition points earlier than beef-types across all stages (interval varying between ∼8 and 12 weeks) and that collectively, native beef breeds moved through the transition points by up to 3 weeks earlier than the continental beef breeds. Interestingly, in contrast to beef animals, dairy females matured before dairy males. However, the magnitude of the difference between dairy females and males diminished at the later stages of development. Differences were found between breeds. Across the first three stages, Ayrshires and Guernseys developed between 3 and 6 weeks later than Friesian/Holsteins and Simmental, Limousin and Blonde Aquitaine 6 and 8 weeks later than Aberdeen Angus. Herefords, Charolais and South Devon developed later but by a smaller interval and Red Devon and Galloway showed the largest individual effect with transition delayed by 8 to 12 weeks.

Steroid hormone-induced effects on membrane fluidity and their potential roles in non-genomic mechanisms.

Steroid hormones are lipophilic suggesting they intercalate into the bilayer of target cell plasma membranes, potentially altering the fluidity and function of the membrane. The present study measured the effects of steroidal exposure on both phospholipid fluidity and integral protein mobility. Studies were performed on the effects of a variety of steroids on phosphatidylcholine liposomes, synaptosomal plasma membranes and sarcoplasmic reticulum membranes. Progesterone decreased the lipid fluidity, whereas testosterone had no effect on lipid movement. The estrogen, 17 beta-estradiol, an aromatised metabolite of testosterone, increased lipid mobility. In each case, the steroid action was concentration-dependent. The steroids all increased the activity of the Ca2+ ATPase of SR membrane, in keeping with their effects on this enzyme's aggregation state. The results suggest that, although lipid fluidity is a factor influencing protein activity, their mobility within the bilayer is the primary determinant of enzyme activity in the membrane for most proteins.

Time perception in boys with attention-deficit/hyperactivity disorder according to time duration, distraction and mode of presentation.

In a recent theoretical model of attention-deficit/hyperactivity disorder (ADHD), Barkley (1997a) predicted that ADHD children experience impairments in their psychological sense of time. This was demonstrated in a series of experiments by Barkley, Koplowicz, Anderson, and McMurray (1997). The present study sought to investigate the effects of ADHD subtype, stimulus duration, mode of presentation (visual versus auditory) and distractors on the performance of a simple time reproduction task. Data were obtained from 44 ADHD children (14 predominantly inattentive and 30 combined type) and 44 age-matched Controls using the Time Perception Application version 1.0 (Barkley, University of Massachusetts Medical Center, 1998). Results revealed that the ADHD children made significantly larger errors on Visual time reproduction tasks than the Controls, regardless of ADHD subtype or the presence of distractors. Furthermore, ADHD children were more likely to overestimate the shorter time intervals (0.5 and 2 s) and underestimate the longer time intervals (3, 4 and 6 s) relative to Controls. No group differences were observed on the auditory time reproduction task, with both ADHD and Control groups consistently underestimating the durations to be reproduced. The results of this study provide further support for the prediction that children with ADHD have an impaired sense of time.

Differential patterns of executive function in children with attention-deficit hyperactivity disorder according to gender and subtype.

The present investigation examined differential patterns in executive functions of children with attention-deficit hyperactivity disorder (ADHD; no diagnosed comorbid disorders) according to subtype and gender, and identified instrumentation sensitive to executive function in children aged 6 to 12 years with ADHD. Data were obtained from 94 children diagnosed with ADHD (predominantly inattentive, n = 32, ADHD combined, n = 62), and from 28 controls. Participants with ADHD, who were unmedicated at the time of testing, were administered five tests of executive function (the Wisconsin Card Sorting Test, the Stroop Color-Word Test, the Matching Familiar Figures Test, the Trail Making Test, and the Tower of London). A two-way multivariate analysis of covariance with age as the covariate and subtype and gender as the independent variables was conducted on all of the tests administered. While children with ADHD predominantly inattentive and those with ADHD combined differed from controls, it was only the latter subtype that differed significantly in perseveration and response inhibition. The absence of diagnosed comorbidity in the children with ADHD at the time of test administration demonstrates that the impairments in executive function are clearly located in ADHD, particularly in the ADHD combined subtype, thus providing support for Barkley's proposed unifying theory of ADHD.

The effects of broadband noise masking on cortical event-related potentials to speech sounds /ba/ and /da/.

OBJECTIVE: To systematically investigate in normal-hearing listeners the effects of decreased audibility produced by broadband noise masking on the cortical event-related potentials (ERPs) N1, N2, and P3 to the speech sounds /ba/ and /da/. DESIGN: Ten normal-hearing adult listeners actively (button-press response) discriminated the speech sounds /ba/ and /da/ presented in quiet (no masking) or with broadband masking noise (BBN), using an ERP oddball paradigm. The BBN was presented at 50, 60, and 70 dB SPL when speech sounds were presented at 65 dB ppe SPL and at 60, 70 and, 80 dB SPL when speech sounds were presented at 80 dB ppe SPL. RESULTS: On average, the 50, 60, 70, and 80 dB SPL BBN maskers produced behavioral threshold elevations of 18, 25, 35, and 48 dB (average for 250 to 4000 Hz), respectively. The BBN maskers produced significant decreases (relative to quiet condition) in ERP amplitudes and behavioral discriminability. These decreases did not occur, however, until the noise masker intensity (in dB SPL) was equal to or greater than the speech stimulus intensity (in dB ppe SPL), that is, until speech to noise ratios (SNRs) were < or = 0 dB. N1 remained present even after N2, P3, and behavioral discriminability were absent. In contrast to amplitudes, ERP and behavioral latencies showed significant decreases at higher (better) SNRs. Significant latency increases occurred when the noise maskers were within 10 to 20 dB of the stimuli (i.e., SNR < or = 20 dB). The effects of masking were greater for responses to /da/ compared with /ba/. Latency increases occurred with less masking for N1 than for P3 or behavioral reaction time, with N2 falling in between. CONCLUSIONS: These results indicate that decreased audibility as a result of masking affects the various ERP peaks in a differential manner and that latencies are more sensitive indicators of these masking effects than are amplitudes.

Changes in the neuronal membranes of mice related to steroid hormone influences.

Changes in the biochemical composition of synaptosomal plasma membranes (SPM) isolated from mouse brains have been measured. The protein, phospholipid, and cholesterol contents all increased over the first 30 days of postnatal life, with the cholesterol to phospholipid molar ratio (one of the major determinants of lipid fluidity) also increasing in direct relation to the decrease in lipid fluidity. The fatty acid composition of SPM also changes with the increase in 18:0, and the decrease in 18:2, 18:3, and 22:4, in keeping with the increase in membrane order. Steroid hormones alter lipid fluidity to a greater degree in fluid membranes, indicating that the nongenomic effects of steroids will be most prevalent in membranes during the early prenatal period and for the first days following birth. The potential effects of xenobiotics on membrane fluidity are also discussed.

Characterization of profilaggrin endoproteinase 1. A regulated cytoplasmic endoproteinase of epidermis.

Profilaggrin, an insoluble precursor of the intermediate filament-associated protein filaggrin, contains multiple internal repeats (PIRs). At terminal differentiation of epidermis, proteolytic processing within a "linker" region of each PIR releases soluble filaggrin in a two-stage process. The first stage endoproteinase (PEP1, profilaggrin endoproteinase 1) cleaves mouse profilaggrin at a subset of the linkers, yielding processing intermediates consisting of several filaggrin repeats. An epidermal endoproteinase that cleaves the requisite linker subset has been purified 4,966-fold from mouse epidermal extracts. SDS-polyacrylamide gel electrophoresis demonstrated a band of molecular mass of 29.5 kDa that correlated with the activity. Labeling with [3H]diisopropylfluorophosphate identified PEP1 as a serine protease; inhibitor studies suggest that it is similar to chymotrypsin, as expected from previous in vivo studies. The purified PEP1 cleaved a peptide derived from profilaggrin (P1) at three residues within and adjacent to a multiple tyrosine sequence, consistent with the in vivo processing sites. No exopeptidase activity was detected. PEP1 is only active toward insoluble profilaggrin, resulting in partial solubilization, consistent with a role in dispersal of profilaggrin during terminal differentiation. In contrast to the specific cleavage of mouse profilaggrin, PEP1 cleaved all linker regions of rat profilaggrin. Studies with phosphorylated P1 suggest that PEP1 specificity may be partly regulated by profilaggrin phosphorylation.

Biological variation in glycated proteins.

The high degree of individuality in the fructosamine assay has been ascribed to non-specific interferences in the assay. To investigate this, we measured the biological variability of 10 non-diabetic subjects using the fructosamine assay, the new fructosamine plus assay, glycated albumin and glycated total plasma proteins by affinity chromatography. The total variation of the two fructosamine assays was half that of the affinity chromatography assays. This was mainly due to the greater analytical imprecision of the affinity chromatography assays. The resulting high index of heterogeneity for both affinity methods makes it difficult to assess the significance of changes in serial results. The within-subject variation made a small contribution to the total variation for all the assays, and was particularly low for the fructosamine assays. This suggests that any non-specific component makes a constant contribution to the measured fructosamine activity in non-diabetic subjects. The fructosamine assays therefore have significant advantages over the affinity chromatography methods as indices of medium-term glycaemic control.

The role of central nervous system functioning and family functioning in behavioral problems of children with myelodysplasia.

This study examined the frequency and type of behavioral problems in 50 children with myelodysplasia and investigated the hypothesized roles of central nervous system (CNS) functioning and family functioning in behavioral problem outcome. The findings revealed that 50% of the children with myelodysplasia had a behavioral problem pattern and another 2% had low social skills, yielding an overall problem pattern rate of 52%. There was a high frequency of internalizing behavior problem profiles and a very low frequency of externalizing behavior problem profiles. Although there was little support for the hypothesized mediating role of central nervous system functioning, considerable support was provided for the association of family functioning and behavior problem outcomes.

Interaction of long-term stored platelets with vascular subendothelium.

Platelets stored as platelet-rich plasma under mildly alkaline conditions in vitro maintain morphologic integrity and functional capability for 2 to 3 weeks. We used the Baumgartner method to assess the ability of long-term stored platelets to interact with exposed vascular subendothelium. After 3 days in storage the size and number of thrombi on damaged surfaces decreased. However, the percentage of vascular surface covered was not reduced significantly until the cells had been stored for 14 days. Treatment of vascular segments with chymotrypsin to increase thrombogenicity caused platelets stored for 14 days to adhere and form aggregates on denuded surfaces in a manner similar to that of fresh platelets, but the ability to develop thrombi remained depressed. Thus long-term storage that maintains physical and functional integrity also preserves a reasonable capacity of platelets to interact with damaged blood vessels.

Lymphocyte beta-adrenergic receptor density of patients with recurrent affective illness.

The binding characteristics of (-)3-[125I]iodocyanopindolol, a high specific activity antagonist for the lymphocyte beta-adrenoceptor, were determined in a group of euthymic lithium-treated patients and controls. There was a statistically significant reduction (less than 20%) in the density of beta-adrenoceptors in a group of 56 lithium-treated patients. Division of this group of patients into the unipolar and bipolar distinction indicated that the abnormality was based mainly in the bipolar group of patients. The unipolar patients with an endogenous form of the illness also showed this abnormality. Reduced beta-adrenoceptor density may be associated with endogenous affective illness. However, the results must be interpreted with caution since lymphocyte fractions prepared for beta-adrenoceptor assays can be contaminated with platelets and since platelets have been reported to have beta-receptors then a proportion of the total binding could be associated with platelet beta-adrenoceptors rather than with lymphocyte beta-adrenoceptors.

Freeze-fracture electron microscopy of human erythrocytes lacking the major membrane sialoglycoprotein.

Human erythrocytes of blood group En (a-), a rare homozygous condition involving a complete lack of the major sialoglycoprotein of the cell membrane (glycophorin A), were compared with erythrocytes from normal (En (a+)) individuals by freeze-fracture electron microscopy. No decrease in number, or variation in morphology, of the intramembranal particles of En (a-) cells was detectable. The results show that the erythrocyte sialoglycoprotein is not essential for the maintenance of the integrity of the intramembranal particles of the human erythrocyte membrane.