Intramammary infections and risk factors in freshly calved heifers in Swedish dairy herds.

Subclinical mastitis can be common among freshly calved heifers (FCH), but the prevalence differs between herds, possibly due to variation in risk factors. The aims of this observational study were to identify differences in occurrence of intramammary infection (IMI) in FCH between herds with documented good or poorer first-parity udder health based on cow somatic cell count (CSCC) in early lactation, and to study herd differences in animal factors important for udder health, such as udder and hock skin lesions and animal cleanliness. Three groups of herds were included: those with high proportions of FCH with low CSCC (≤75,000 cells/mL) at the first 2 milk recordings after calving (LL), herds with high proportions of FCH with high CSCC (>100,000 cells/mL) at the first and low CSCC at the second recording (HL), and herds with high proportions of FCH with high CSCC at both recordings (HH). Thirty-nine herds (13 LL, 11 HL, 15 HH) were visited 3 times during a 12-mo period for observation of cleanliness and hock lesions, and sampling of udder and teat skin using swab cloths of milk-fed calves, early-pregnant heifers, and late-pregnant heifers. In 25 (9 LL, 9 HL, 7 HH) udder quarter samples from colostrum and milk on d 3 to 4 after calving were taken by the farmers from FCH during one year. The farmers also provided information on calving (individual or group), use of restraint and oxytocin at milking, and presence of teat and udder skin lesions. Bacterial growth in swab samples and quarter samples was investigated by culturing, and a selection of isolates was genotyped using whole-genome sequencing. Cleanliness, hock and udder skin lesions other than udder-thigh dermatitis, and growth of bacteria in swab samples did not differ between herd groups. It was more common that FCH from LL herds, compared with FCH in HH and HL herds, calved in a group of animals. Use of restraint at milking was more common in LL herds than in HH herds, whereas presence of udder-thigh dermatitis was lowest in LL herds. Specific infection was found in 14% of 5,593 quarter samples from 722 FCH. The most common IMI was Staphylococcus chromogenes. Growth of Staphylococcus simulans was more common in HH than in LL and HL herds. In colostrum samples, Staphylococcus haemolyticus was more common in HL and HH than in LL herds. The proportion of quarters with the same specific infection at both samplings was higher in HH than in LL herds and tended to be higher in HH than in HL herds. The proportion of quarters with Staph. chromogenes IMI at both samplings tended to differ between herd groups and was highest in HH herds. Whole-genome sequencing found the same sequence type of Staph. chromogenes and Staphylococcus aureus in both samples in almost all quarters with the same infection at both samplings. The differences in IMI between herd groups were in line with the higher somatic cell count in HH herds. The reasons for the predominance of Staph. chromogenes IMI in FCH need further studies.

Herd-level prevalence of Mycoplasma bovis in Swedish dairy herds determined by antibody ELISA and PCR on bulk tank milk and herd characteristics associated with seropositivity.

Mycoplasma bovis is an important pathogen causing pneumonia, mastitis, and arthritis in cattle, leading to reduced animal welfare and economic losses worldwide. In this cross-sectional study, we investigated the prevalence of M. bovis in bulk tank milk (BTM) and herd characteristics associated with a positive antibody test result in Swedish dairy herds. Bulk tank milk samples from all Swedish dairy herds (n = 3,144) were collected and analyzed with ID Screen antibody ELISA and PCR. Information on herd characteristics was collected from the national Dairy Herd Improvement database. To identify herd characteristics associated with the presence of antibodies in BTM, logistic regression was used in 4 different models. The apparent herd-level prevalence of M. bovis infection based on antibodies in BTM was 4.8%, with large regional differences ranging from 0 to 20%. None of the BTM samples was positive by PCR. All the antibody-positive herds were situated in the south of Sweden. The logistic regression model showed that larger herds had higher odds of detectable antibodies in BTM (herd size >120 cows, odds ratio = 8.8). An association was also found between antibodies in BTM and both a higher late calf mortality (2-6 mo) and a higher young stock mortality (6-15 mo). This study showed a clear regional difference in the apparent prevalence of M. bovis infection based on antibodies. The relatively low prevalence of M. bovis in Sweden is a strong motivator for the cattle industry to take steps to prevent further spread of the infection. It is essential that the M. bovis status of free herds be known, and the regional differences shown in this study suggest that testing is highly recommended when live cattle from high-prevalence areas are being introduced into herds. We do not recommend using PCR on BTM to detect infected herds, owing to the low detection frequency in this study.

Eligibility for sacubitril/valsartan in heart failure across the ejection fraction spectrum: real-world data from the Swedish Heart Failure Registry.

BACKGROUND: Randomized controlled trials (RCT) generalizability may be limited due to strict patient selection. OBJECTIVE: In a real-world heart failure (HF) population, we assessed eligibility for sacubitril/valsartan based on PARADIGM-HF (sacubitril/valsartan effective)/PARAGON-HF [sacubitril/valsartan effective in mildly reduced ejection fraction (EF)]. METHODS: Outpatients from the Swedish HF Registry (SwedeHF) were analysed. In SwedeHF, EF is recorded as <30, 30-39, 40-49 and ≥50%. In PARAGON-HF, sacubitril/valsartan was effective with EF ≤ 57% (i.e. median). We defined reduced EF/PARADIGM-HF as EF < 40%, mildly reduced EF/PARAGON-HF ≤ median as EF 40-49%, and normal EF/PARAGON-HF > median as EF ≥ 50%. We assessed 2 scenarios: (i) criteria likely to influence treatment decisions (pragmatic scenario); (ii) all criteria (literal scenario). RESULTS: Of 37 790 outpatients, 57% had EF < 40%, 24% EF 40-49% and 19% EF ≥ 50%. In the pragmatic scenario, 63% were eligible in EF < 50% (67% for EF < 40% and 52% for 40-49%) and 52% in EF ≥ 40% (52% for EF ≥ 50%). For the literal scenario, 32% were eligible in EF < 50% (38% of EF < 40%, 20% of EF 40-49%) and 22% in EF ≥ 40% (25% for EF ≥ 50%). Eligible vs. noneligible patients had more severe HF, more comorbidities and overall worse outcomes. CONCLUSION: In a real-world HF outpatient cohort, 81% of patients had EF < 50%, with 63% eligible for sacubitril/valsartan based on pragmatic criteria and 32% eligible based on literal trial criteria. Similar eligibility was observed for EF 40-49% and ≥50%, suggesting that our estimates for EF < 50% may be reproduced whether or not a higher cut-off for EF is considered.

Risk and success factors for good udder health of early lactation primiparous dairy cows.

We compared the management and housing of dairy heifers from calf to calving in herds that were very successful versus less successful in preventing mastitis in early lactation primiparous cows. This retrospective observational study included 170 Swedish dairy herds. Eligible herds were identified from the Swedish official milk recording scheme (SOMRS). Each herd had at least 60 cows per year, production data from 3 consecutive years, and at least 10 primiparous cows per year with their first milk recording 5 to 35 d after calving and their second milk recording 20 to 40 d after the first milk recording. In each herd, primiparous cows with a low (≤75,000 cells/mL) cow somatic cell count (CSCC) at both the first and second milk recording were categorized as low-low (LL); those with a high (>100,000 cells/mL) CSCC at both recordings were categorized as high-high (HH). Cows with high CSCC at the first recording and low at the second were categorized as high-low (HL). The annual proportions of LL, HL, and HH cows within each herd were calculated. Herds with an above-median proportion of LL, HL, or HH cows during the first year of a 3-yr selection period, and above the third quartile proportion of LL, HL, or HH cows, respectively, during the second and third year were identified. These herds (LL herds, n = 129; HL herds, n = 92; HH herds, n = 139) were contacted until a maximum of 60 herds per category had agreed to participate. Field technicians/veterinarians visited each herd once in the mid to late indoor season to collect data on housing and management of the heifers from birth to calving. Additional data were retrieved from the SOMRS. Associations between herd category (LL, HL, or HH) and variables collected were analyzed in 8 multivariable multinomial logistic regression submodels covering herd characteristics, milk-fed calves, heifers in early pregnancy, heifers in late pregnancy, calving and colostrum period, miscellaneous factors, summarized heifer housing data, and general health, culling, and fertility data. A final multivariable model was built from the results of the submodels and univariable analyses. The final model showed that having a standard operating procedure for colostrum feeding was more common in LL and HL herds than in HH herds; the mean bulk milk SCC and overall culling rate due to udder health was higher in HH herds than in LL and HL herds; and automatic milking was less common in LL herds than in HL and HH herds. Several herd and management variables differed between herd categories in the submodels. In conclusion, we identified several success factors for herds with good udder health among early lactation primiparous cows. This knowledge can be used to improve preventive measures in dairy herds to ensure sustainable and economic milk production.

Udder health of early-lactation primiparous dairy cows based on somatic cell count categories.

The aims were to investigate the prevalence of intramammary infection in early-lactation primiparous dairy cows (PC) in Sweden using milk recording cow composite somatic cell count (CSCC) categories based on classification of CSCC at the first 2 milk recordings after calving as low or high using cut-offs indicating intramammary infection. We also wanted to evaluate if herd-specific patterns in CSCC categories among PC can be identified to indicate success and problem herds as well as cow-level associations between CSCC categories and breed and sire, and herd-level associations between CSCC categories and herd size, milk production, production system, milking system, and year. A total of 1,597 dairy herds were included. Inclusion criteria were enrolment in the Swedish official milk recording scheme and having production data from at least 10 PC per year during 2014, 2015, and 2016. Herd (size, SCC, milk production, production system, milking system) and cow (breed, lactation number, calving date, CSCC, milk production) data were collected from the Swedish official milk recording scheme. Each PC was assigned a CSCC category (low-low, low-high, high-high, high-low, or inconclusive) based on the CSCC at the first 2 milk recordings using the following cut-offs. At each milk recording a CSCC ≤75,000 cells/mL was considered low and a CSCC >100,000 cells/mL was considered high, whereas a CSCC in between those values was considered inconclusive. Associations between CSCC categories and breed or sire of the PC were analyzed using multivariable multinomial logistic regression models. Associations at herd level between number of PC in a CSCC category and herd variables were analyzed using multivariable Poisson or negative binomial regression models. The annual proportions of CSCC categories for all PC were 51.3%, 5.5%, 15.5%, 13.7%, and 14.0% for the low-low, low-high, high-low, high-high, and inconclusive categories, respectively. The distribution of CSCC categories varied markedly between herds. Overall, the median herd prevalence was 50.2 to 54.2% and 11.7 to 13.2% per year for the low-low and high-high categories, respectively. At cow level, both breed and sire were significantly associated with CSCC categories, showing for example that a higher proportion of Jersey PC were categorized as high-high compared with Swedish Holstein (SH) and Swedish Red (SR) PC, and that PC of certain SH and SR sires more often were categorized as low-low or high-high cows than PC of other sires within each breed. All herd factors, except conventional and organic production, were significantly associated with the proportion of PC in a CSCC category at herd level. For example, the proportion of PC in the low-low category was significantly lower in larger herds (≥80 cows) compared with smaller herds (<80 cows) and significantly lower in automatic milking system herds than in herds with other milking systems, but significantly higher in herds with higher milk production. Overall, the results indicate a substantial need for prevention of subclinical mastitis in early-lactation PC as only 50% of these cows had low CSCC at both milk recordings after calving. Moreover, we conclude that CSCC categories may be a useful tool for identifying success and problem herds.

Functional and homeostatic defects of regulatory T cells in patients with coronary artery disease.

OBJECTIVE: Regulatory T cells (Tregs) are considered atheroprotective, and low levels have been associated with the acute coronary syndrome (ACS), particularly non-ST elevation (NSTE)-ACS. However, the functional properties as well as homeostasis of Tregs are mainly unknown in coronary artery disease (CAD). Here, we investigated the composition and functional properties of naïve (n) and memory (m)Tregs in patients with NSTE-ACS and in patients 6-12 months post-ACS. METHODS: Based on the expression of CD25, FOXP3, CD127, CD45RA, CD39 and CTLA-4, Treg subsets were defined by flow cytometry in whole blood or isolated CD4(+) T cells. The functional properties of nTregs and mTregs were examined in terms of proliferative capacity and modulation of cytokine secretion. To understand the potential consequences of Treg defects, we also investigated correlations with lipopolysaccharide (LPS)-induced cytokine secretion and ultrasound-defined carotid atherosclerosis. RESULTS: Both NSTE-ACS and post-ACS patients exhibited reduced levels of nTregs (P < 0.001) compared with healthy control subjects, but without compensatory increases in mTregs. Both nTregs and mTregs from patients showed significantly lower replicative rates and impaired capacity to modulate T-cell proliferation and secretion of interferon-gamma and IL-10. The Treg defect was also associated with LPS-induced cytokine secretion and increased burden of carotid atherosclerosis. CONCLUSION: Our results demonstrate a functional and homeostatic Treg defect in patients with NSTE-ACS and also in stabilized patients 6-12 months after ACS. Moreover, this defect was associated with a subclinical proinflammatory and atherogenic state. We believe that the failure to preserve Treg function and homeostasis reflects a need for immune-restoring strategies in CAD.

Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis at calving in dairy herds with suboptimal udder health.

Udder infections with Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis are common causes of bovine mastitis. To study these pathogens in early lactation, a 12-mo longitudinal, observational study was carried out in 13 herds with suboptimal udder health. The aims of the study were to investigate the occurrence of these pathogens and to identify if presence of the 3 pathogens, and of genotypes within the pathogens, differed with respect to herd, season, and parity. Quarter milk samples, collected at calving and 4 d in milk (DIM), were cultured for the 3 pathogens. Genotyping of staphylococcal and streptococcal isolates was performed using spa typing and pulsed-field gel electrophoresis, respectively. For each of the 3 pathogens, cows with an udder infection at calving or 4 DIM were allocated to 1 of 4 infection types: cleared (pathogen present only at calving), persistent (pathogen present in the same quarter at calving and 4 DIM), new (pathogen present only at 4 DIM), or cleared/new (pathogen present in 1 quarter at calving and in another quarter at 4 DIM). Associations between season or parity and overall occurrence of pathogens or infection types were determined using univariable mixed-effect logistic-regression models and the Fisher's exact test, respectively. The most commonly occurring pathogen was Staph. aureus, followed by Strep. dysgalactiae and Strep. uberis. Persistent infections were the most common infection type among Staph. aureus-infected cows, whereas cleared infections were the most common among Strep. dysgalactiae- and Strep. uberis-positive cows. The proportion of cows with persistent Staph. aureus infections and the proportion of cows having a Strep. uberis infection at calving or 4 DIM were higher in the multiparous cows than in primiparous cows. Infections with Strep. dysgalactiae were less common during the early housing season than during the late housing or pasture seasons, whereas persistent Strep. uberis infections were less common during the pasture season than during the late housing season. The relative occurrence of the 3 pathogens, infection types of each pathogen, and genotype diversity of each pathogen throughout the year or in different seasons and parities varied among the herds, indicating that underlying factors predisposing for udder infections at calving differ between herds. Genotyping of bacterial isolates gave important insight into how such infection patterns differed within and between herds. These findings emphasize the need to choose preventive strategies for each individual herd.

Genes involved in senescence and immortalization.

Senescence is now understood to be the final phenotypic state adopted by a cell in response to several distinct cell physiological processes, including proliferation, oncogene activation and oxygen free radical toxicity. The role of telomere maintenance in immortalization and the roles of p16(INK4A), p19(ARF), p53 and other genes in senescence are being further elucidated. Significant progress continues to be made in our understanding of cellular senescence and immortalization.

Influence of early gut microbiota on the maturation of childhood mucosal and systemic immune responses.

INTRODUCTION: Among sensitized infants, those with high, as compared with low levels, of salivary secretory IgA (SIgA) are less likely to develop allergic symptoms. Also, early colonization with certain gut microbiota, e.g. Lactobacilli and Bifidobacterium species, might be associated with less allergy development. Although animal and in vitro studies emphasize the role of the commensal gut microbiota in the development of the immune system, the influence of the gut microbiota on immune development in infants is unclear. OBJECTIVE: To assess whether early colonization with certain gut microbiota species associates with mucosal and systemic immune responses i.e. salivary SIgA and the spontaneous Toll-like receptor (TLR) 2 and TLR4 mRNA expression and lipopolysaccharide (LPS)-induced cytokine/chemokine responses in peripheral blood mononuclear cells (PBMCs). METHODS: Fecal samples were collected at 1 week, 1 month and 2 months after birth from 64 Swedish infants, followed prospectively up to 5 years of age. Bacterial DNA was analysed with real-time PCR using primers binding to Clostridium difficile, four species of bifidobacteria, two lactobacilli groups and Bacteroides fragilis. Saliva was collected at age 6 and 12 months and at 2 and 5 years and SIgA was measured with ELISA. The PBMCs, collected 12 months after birth, were analysed for TLR2 and TLR4 mRNA expression with real-time PCR. Further, the PBMCs were stimulated with LPS, and cytokine/chemokine responses were measured with Luminex. RESULTS: The number of Bifidobacterium species in the early fecal samples correlated significantly with the total levels of salivary SIgA at 6 months. Early colonization with Bifidobacterium species, lactobacilli groups or C. difficile did not influence TLR2 and TLR4 expression in PBMCs. However, PBMCs from infants colonized early with high amounts of Bacteroides fragilis expressed lower levels of TLR4 mRNA spontaneously. Furthermore, LPS-induced production of inflammatory cytokines and chemokines, e.g. IL-6 and CCL4 (MIP-1 beta), was inversely correlated to the relative amounts of Bacteroides fragilis in the early fecal samples. CONCLUSION: Bifidobacterial diversity may enhance the maturation of the mucosal SIgA system and early intense colonization with Bacteroides fragilis might down-regulate LPS responsiveness in infancy.

Helical axes of skeletal knee joint motion during running.

The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase moved 20mm posteriorly and 10mm distally. At the time of peak flexion, the FHA shifted rapidly by about 10-20mm in proximal and posterior direction. The angle between the FHA and the tibial transverse plane increased gradually during flexion, to about 15 degrees of medial inclination, and then returned to zero at the start of the extension phase. These changes in position and orientation of FHA in the knee should be considered in analyses of muscle function during human movement, which require moment arms to be defined relative to a functional rotation axis. The finding that substantial changes in axis of rotation occurred independent of flexion angle suggests that musculoskeletal models must have more than one kinematic degree-of-freedom at the knee. The same applies to the design of knee prostheses, if the goal is to restore normal muscle function.

Invasive in vivo measurement of rear-, mid- and forefoot motion during walking.

The aim of this work was to use bone anchored external markers to describe the kinematics of the tibia, fibula, talus, calcaneus, navicular, cuboid, medial cuneiform, first and fifth metatarsals during gait. Data were collected from six subjects. There was motion at all the joints studied. Movement between the talus and the tibia showed the expected predominance of sagittal plane motion, but the talocalcaneal joint displayed greater variability than expected in its motion. Movement at the talonavicular joint was greater than at the talocalcaneal joint and motion between the medial cuneiform and navicular was far greater than expected. Motion between the first metatarsal and the medial cuneiform was less than motion between the fifth metatarsal and cuboid. Overall the data demonstrated the complexity of the foot and the importance of the joints distal to the rearfoot in its overall dynamic function.

Functional units of the human foot.

Functional units in the human foot provide a meaningful basis for subdivisions of the entire foot during gait analysis as well as justified simplifications of foot models. The present study aimed to identify such functional units during walking and slow running. An invasive method based upon reflective marker arrays mounted on intracortical pins was used to register motion of seven foot bones. Six healthy subjects were assessed during walking and four of them during slow running. Angle-angle diagrams of corresponding planar bone rotations were plotted against each other and used to establish functional units. Individual functional units were accepted when the joints rotated temporally in phase and either (i) in the same direction, (ii) in the opposite direction, or (iii) when one of the two joints showed no rotation. A functional unit was generalized if all available angle-angle diagrams showed a consistent pattern. A medial array from the navicular to the first metatarsal was found to perform as a functional unit with parts rotating in the same direction and larger rotations occurring proximally. A rigid functional unit comprised the navicular and cuboid. No other functional units were identified. It was concluded that the talus, navicular, and medial cuneiform should neither be regarded as one rigid unit nor as one segment during gait analysis. The first and fifth metatarsals should also be considered separately. It was further concluded that a marker setup for gait analysis should consist of the following four segments: calcaneus, navicular-cuboid, medial cuneiform-first metatarsal, fifth metatarsal.

Functional inactivation of the retinoblastoma protein requires sequential modification by at least two distinct cyclin-cdk complexes.

The retinoblastoma protein (pRb) acts to constrain the G1-S transition in mammalian cells. Phosphorylation of pRb in G1 inactivates its growth-inhibitory function, allowing for cell cycle progression. Although several cyclins and associated cyclin-dependent kinases (cdks) have been implicated in pRb phosphorylation, the precise mechanism by which pRb is phosphorylated in vivo remains unclear. By inhibiting selectively either cdk4/6 or cdk2, we show that endogenous D-type cyclins, acting with cdk4/6, are able to phosphorylate pRb only partially, a process that is likely to be completed by cyclin E-cdk2 complexes. Furthermore, cyclin E-cdk2 is unable to phosphorylate pRb in the absence of prior phosphorylation by cyclin D-cdk4/6 complexes. Complete phosphorylation of pRb, inactivation of E2F binding, and activation of E2F transcription occur only after sequential action of at least two distinct G1 cyclin kinase complexes.

Serum response factor is required for immediate-early gene activation yet is dispensable for proliferation of embryonic stem cells.

Addition of serum to mitogen-starved cells activates the cellular immediate-early gene (IEG) response. Serum response factor (SRF) contributes to such mitogen-stimulated transcriptional induction of many IEGs during the G0-G1 cell cycle transition. SRF is also believed to be essential for cell cycle progression, as impairment of SRF activity by specific antisera or antisense RNA has previously been shown to block mammalian cell proliferation. In contrast, Srf(-/-) mouse embryos grow and develop up to E6.0. Using the embryonic stem (ES) cell system, we demonstrate here that wild-type ES cells do not undergo complete cell cycle arrest upon serum withdrawal but that they can mount an efficient IEG response. This IEG response, however, is severely impaired in Srf(-/-) ES cells, providing the first genetic proof that IEG activation is dependent upon SRF. Also, Srf(-/-) ES cells display altered cellular morphology, reduced cortical actin expression, and an impaired plating efficiency on gelatin. Yet, despite these defects, the proliferation rates of Srf(-/-) ES cells are not substantially altered, demonstrating that SRF function is not required for ES cell cycle progression.

Intrinsic foot kinematics measured in vivo during the stance phase of slow running.

An accurate kinematic description of the intrinsic articulations of the foot during running has not previously been presented, primarily due to methodological limitations. An invasive method based upon reflective marker arrays mounted on intracortical pins drilled into the bones was used in this study. Four male volunteers participated as subjects. Pins (1.6mm diameter) were inserted under local anaesthetic in the tibia, fibula, calcaneus, talus, navicular, cuboid, medial cuneiform and metatarsals I and V. A 10 camera motion analysis system was used for kinematic data capture and the ground reaction force was simultaneously measured. Segment motion relative to adjacent proximal segments was determined using helical axes projected into the coordinate system of the proximal segment. Coefficients of multiple correlation calculated to determine the strength of association between running style with and without the pins inserted indicated that the subjects had little restriction due to the inserted pins. Individual and mean results were presented for rotations defined in the planes of the proximal segment's coordinate system and showed frontal plane rotation of the talocrural joint (12.2+/-7.1 degrees ), which exceeded that of the subtalar joint (8.9+/-3.2 degrees ). Considerable mobility of the talonavicular joint was found (6.5+/-2.9 degrees , 13.5+/-4.1 degrees and 8.7+/-1.4 degrees in the sagittal, frontal and transverse planes, respectively). Furthermore, little, but non-negligible motion between the fibula and tibia was found (3.3+/-2.4 degrees in the sagittal plane). The presented data are of interest as input for future biomechanical modelling and clinical decision making in particular, concerning joint fusion.

Foot kinematics during walking measured using bone and surface mounted markers.

The aim was to compare kinematic data from an experimental foot model comprising four segments ((i) heel, (ii) navicular/cuboid (iii) medial forefoot, (iv) lateral forefoot), to the kinematics of the individual bones comprising each segment. The foot model was represented using two different marker attachment protocols: (a) markers attached directly to the skin; (b) markers attached to rigid plates mounted on the skin. Bone data were collected for the tibia, talus, calcaneus, navicular, cuboid, medial cuneiform and first and fifth metatarsals (n=6). Based on the mean differences between the three data sets during stance, the differences between any two of the three kinematic protocols (i.e. bone vs skin, bone vs plate, skin vs plate) were >3 degrees in only 35% of the data and >5 degrees in only 3.5% of the data. However, the maximum difference between any two of the three protocols during stance was >3 degrees in 100% of the data, >5 degrees in 73% of the data and >8 degrees in 23% of the data. Differences were greatest for motion of the combined navicular/cuboid relative to the calcaneus and the medial forefoot segment relative to the navicular/cuboid. The differences between the data from the skin and plate protocols were consistently smaller than differences between either protocol and the kinematic data for each bone comprising the segment. The pattern of differences between skin and plate protocols and the actual bone motion showed no systematic pattern. It is unlikely that one rigid body foot model and marker attachment approach is always preferable over another.

A five-year radiostereometric follow-up of the Birmingham Hip Resurfacing arthroplasty.

The early designs of hip resurfacing implants suffered high rates of early failure, making it impossible to obtain valuable mid-term radiostereophotogrammetric (RSA) results. The metal-on-metal Birmingham Hip Resurfacing arthroplasty has shown promising mid-term results and we present here the first mid-term RSA analysis of a hip resurfacing implant. The analysis was performed in 19 hips at five years post-operatively. The mean acetabular component translation and rotation, and femoral component translation were compared with the previous RSA measurements at two and six months, and one and two years. There was no statistical significance (t-test, p < or = 0.05) between these consecutive movements, indicating the mid-term stability of the implant.

Main component of soft tissue artifact of the upper-limbs with respect to different functional, daily life and sports movements.

Soft tissue artifact (STA) is the main source of error in kinematic estimation of human movements based on skin markers. Our objective was to determine the components of marker displacements that best describe STA of the shoulder and arm (i.e. clavicle, scapula and humerus). Four participants performed arm flexion and rotation, a daily-life and a sports movement. Three pins with reflective markers were inserted into the clavicle, scapula and humerus. In addition, up to seven skin markers were stuck on each segment. STA was described with a modal approach: individual marker displacements or marker-cluster (i.e. translations, rotations, homotheties and stretches) relative to the local segment coordinate system defined by markers secured to the pins. The modes were then ranked according to the percentage of total STA energy that they explained. Both individual skin marker displacements and marker-cluster geometrical transformations were task-, location-, segment- and subject-specific. However, 85% of the total STA energy was systematically explained by the rigid transformations (i.e. translations and rotations of the marker-cluster). In conclusion, large joint dislocations and limited efficiency of least squares bone pose estimators are expected for the computation of upper limb joint kinematics from skin markers. Future developments shall consider the rigid transformations of marker-clusters in the implementation of an STA model to reduce its effects on kinematics estimation.

Stress-induced release of the S100A8/A9 alarmin is elevated in coronary artery disease patients with impaired cortisol response.

Psychological stress is thought to be an important trigger of cardiovascular events, yet the involved pathways and mediators are largely unknown. Elevated systemic levels of the pro-inflammatory alarmin S100A8/A9 correlate with poor prognosis in coronary artery disease (CAD) patients. Here, we investigated the links between S100A8/A9 release and parameters of anti-inflammatory glucocorticoid secretion in two different cohorts subjected to a psychological stress test. In the first cohort of 60 CAD patients, psychological stress induced a rapid increase of circulating S100A8/A9. This rapid S100A8/A9 response strongly correlated with elevated evening saliva cortisol levels, suggesting an association with a dysregulated hypothalamic-pituitary-adrenal (HPA) axis. In the second cohort of 27 CAD patients and 28 controls, elevated S100A8/A9 levels were still detectable 24 h after stress in 40% of patients and 36% of controls, with a tendency for higher levels in patients. The sustained S100A8/A9 response was associated with a poor rapid cortisol release after stress in patients, but not in the control group. Our findings reveal for the first time that acute psychological stress induces elevated levels of S100A8/A9. We also provide hypothesis-generating evidence that dysregulated cortisol secretion in CAD patients might be associated with an exaggerated pro-inflammatory S100A8/A9 response.

Determining in vivo sternoclavicular, acromioclavicular and glenohumeral joint centre locations from skin markers, CT-scans and intracortical pins: A comparison study.

To describe shoulder motion the sternoclavicular, acromioclavicular and glenohumeral joint centres must be accurately located. Within the literature various methods to estimate joint centres of rotation location are proposed, with no agreement of the method best suited to the shoulder. The objective of this study was to determine the most reliable non-invasive method for locating joint centre locations of the shoulder complex. Functional methods using pin mounted markers were compared to anatomical methods, functional methods using skin mounted markers, imaging-based methods using CT-scan data, and regression equations. Three participants took part in the study, that involved insertion of intracortical pins into the clavicle, scapula and humerus, a CT-scan of the shoulder, and finally data collection using a motion analysis system. The various methods to estimate joint centre location did not all agree, however suggestions about the most reliable non-invasive methods could be made. For the sternoclavicular joint, the authors suggest the anatomical method using the most ventral landmark on the sternoclavicular joint, as recommended by the International Society of Biomechanics. For the acromioclavicular joint, the authors suggest the anatomical method using the landmark defined as the most dorsal point on the acromioclavicular joint, as proposed by van der Helm. For the glenohumeral joint, the simple regression equation of Rab is recommended.