Quantitative analysis of penicillins in porcine tissues, milk and animal feed using derivatisation with piperidine and stable isotope dilution liquid chromatography tandem mass spectrometry

Penicillins are used universally in both human and veterinary medicine. The European Union (EU) has established maximum residue levels (MRLs) for most ß-lactam antibiotics in milk and animal tissues and included them in the National Residue Monitoring Programs. In this study, a novel method is described for the determination and confirmation of eight penicillins in porcine tissues, milk and animal feed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). To prevent degradation of penicillin residues during workup, a derivatisation procedure was developed, by which penicillins were converted to stable piperidine derivatives. Deuterated piperidine derivatives were synthesised for all relevant penicillins, enabling the use of isotope dilution for accurate quantification. Penicillin residues were derivatised in the crude extract with piperidine and isolated using solid-phase extraction. The penicillin piperidine derivatives were determined by LC–MS/MS. The method was validated at the current MRLs, which range from 25–300 µg kg−1 in muscle and kidney to 4–30 µg kg−1 in milk as well as at the target value of 100 µg kg−1 chosen for animal feed, according to the EU requirements for a quantitative confirmatory method. Accuracy ranged from 94–113% (muscle), 83–111% (kidney) and 87–103% (milk) to 88–116% (animal feed). Intra-day precision (relative standard deviation (RSD)r) ranged from 5–13% (muscle, n = 18), 4–17% (kidney, n = 7) and 5–18% (milk, n = 7) to 11–32% (animal feed, n = 18). Inter-day precision (RSDRL, n = 18) ranged from 6–23% (muscle) to 11–36% (animal feed). From the results, it was concluded that the method was fit for purpose at the target MRLs in animal tissue and target levels for animal feed

W/M serrated osteotomy for infantile Blount’s disease in Ghana: Short‑term results

Purpose: The W/M serrated high tibial osteotomy is a not frequently described surgical technique for simultaneously correcting the varus and torsional deformity in patients with Blount’s disease. Without the need for internal fixation, this surgical treatment is well suited for developing countries. This study describes the short‑term results of the bilateral and unilateral W/M serrated osteotomy in patients with infantile Blount’s disease.Methods: Between May 2008 and January 2013, 52 patients were treated with uni‑ (n = 22) or bi‑lateral (n = 30) W/M serrated osteotomy of the proximal tibia due to a tibial varus deformity in two district hospitals in Ghana. Other causes than infantile Blount’s disease were excluded from the analysis. Pre‑ and post‑operative clinical and radiological measurements were done, and complications were monitored up to 12 weeks after surgery.Results: Seventeen patients (five males, 12 females; mean age 4.9 [standard deviation: 2.10]) were included, which underwent a total of 25 W/M serrated osteotomies. The femorotibial angle was corrected from 34.1° ([mean] range: 6 68°) to − 7.1° ([mean] range: −28–5°). Only one patient had developed a wound infection, and all reached full consolidation.Conclusions: The W/M serrated osteotomy seems a profitable alternative technique for treating the varus and torsional deformity in patients with Blount’s disease in the circumstances of developing countries. The short‑term outcomes are good and promising with a low complication rate and good consolidation. Long‑term follow‑up results of these patients are needed to observe possible complications.Level of Evidence: IV, therapeutic case series.Keywords: Blount’s disease, complications, infantile, osteotomy, tibia var

Knee adduction moments are not increased in obese knee osteoarthritis patients during stair negotiation

Background: Negotiating stairs is an important activity of daily living that is also associated with large loads on the knee joint. In medial compartment knee osteoarthritis, the knee adduction moment during level walking is considered a marker for disease severity. It could be argued that the discriminative capability of this parameter is even better if tested in a strenuous stair negotiation task. Research question: What is the relation with knee osteoarthritis on the knee adduction moment during the stance phase of both stair ascent and descent in patients with and without obesity? Methods: This case control study included 22 lean controls, 16 lean knee osteoarthritis patients, and 14 obese knee osteoarthritis patients. All subjects ascended and descended a two-step staircase at a self-selected, comfortable speed. Three-dimensional motion analysis was performed to evaluate the knee adduction moment during stair negotiation. Results: Obese knee osteoarthritis patients show a prolonged stance time together with a more flattened knee adduction moment curve during stair ascent. Normalized knee adduction moment impulse, as well as the first and second peaks were not different between groups. During stair descent, a similar increase in stance time was found for both osteoarthritis groups. Significance: The absence of a significant effect of groups on the normalized knee adduction moment during stair negotiation may be explained by a lower ambulatory speed in the obese knee osteoarthritis group, that effectively lowers vertical ground reaction force. Decreasing ambulatory speed may be an effective strategy to lower knee adduction moment during stair negotiation

Subpopulations of bovine WC1+ γδ T cells rather than CD4+CD25highFoxp3+ T cells act as immune regulatory cells ex vivo

Regulatory T cells (Treg) are regarded essential components for maintenance of immune homeostasis. Especially CD4+CD25high T cells are considered to be important regulators of immune reactivity. In humans and rodents these natural Treg are characterized by their anergic nature, defined as a non-proliferative state, suppressive function and expression of Foxp3. In this study the potential functional role of flowcytometry-sorted bovine white blood cell populations, including CD4+CD25high T cells and γδ T cell subpopulations, as distinct ex vivo regulatory cells was assessed in co-culture suppression assays. Our findings revealed that despite the existence of a distinct bovine CD4+CD25high T cell population, which showed Foxp3 transcription/expression, natural regulatory activity did not reside in this cell population. In bovine co-culture suppression assays these cells were neither anergic nor suppressive. Subsequently, the following cell populations were tested functionally for regulatory activity: CD4+CD25low T cells, WC1+, WC1.1+ and WC1.2+ γδ T cells, NK cells, CD8+ T cells and CD14+ monocytes. Only the WC1.1+ and WC1.2+ γδ T cells and CD14+ monocytes proved to act as regulatory cells in cattle, which was supported by the fact that these regulatory cells showed IL-10 transcription/expression. In conclusion, our data provide first evidence that cattle CD4+CD25highFoxp3+ and CD4+CD25low T cells do not function as Treg ex vivo. The bovine Treg function appears to reside in the γδ T cell population, more precisely in the WC1.1+ and the WC1.2+ subpopulation, major populations present in blood of cattle in contrast to non-ruminant species

The Glasgow-Maastricht foot model, evaluation of a 26 segment kinematic model of the foot

BACKGROUND: Accurately measuring of intrinsic foot kinematics using skin mounted markers is difficult, limited in part by the physical dimensions of the foot. Existing kinematic foot models solve this problem by combining multiple bones into idealized rigid segments. This study presents a novel foot model that allows the motion of the 26 bones to be individually estimated via a combination of partial joint constraints and coupling the motion of separate joints using kinematic rhythms. METHODS: Segmented CT data from one healthy subject was used to create a template Glasgow-Maastricht foot model (GM-model). Following this, the template was scaled to produce subject-specific models for five additional healthy participants using a surface scan of the foot and ankle. Forty-three skin mounted markers, mainly positioned around the foot and ankle, were used to capture the stance phase of the right foot of the six healthy participants during walking. The GM-model was then applied to calculate the intrinsic foot kinematics. RESULTS: Distinct motion patterns where found for all joints. The variability in outcome depended on the location of the joint, with reasonable results for sagittal plane motions and poor results for transverse plane motions. CONCLUSIONS: The results of the GM-model were comparable with existing literature, including bone pin studies, with respect to the range of motion, motion pattern and timing of the motion in the studied joints. This novel model is the most complete kinematic model to date. Further evaluation of the model is warranted

Changing from batch to flow assembly in the production of emergency lighting devices.

Current assembly enterprises are under a lot of pressure, as they are faced with increasing volume demands and product variations, needs for shorter delivery times and cost reduction. This pressure is likely to increase the pressure on individual workers. In many small to medium-sized enterprises (SMEs), we observe that traditional assembly concepts are no longer fulfilled. These are challenged to find other concepts to meet today's demands. In a company where emergency lighting devices are assembled in batches (large series of products are assembled step by step), we applied a participatory and integrative approach to set up a mixed flow assembly system including ergonomically designed work stations. In this paper, we describe the approach and the effects which were studied by a within-subject design. We observed an increase of 44% in productivity and a reduction in order lead time of 46%. The time that workers spent to added-value activities increased significantly from 74% to 92%, without any increase in postural and experienced loads. Instead, the workers experienced significantly less overall fatigue at the end of the day in the new situation. The results show the potential benefits of the approach for the many SMEs where products are assembled in batches and faced with the problem of meeting current production demands. © 2005 Taylor & Francis Group Ltd