Schmallenberg Virus beyond Latitude 65°N

Extensive and rapid spread of Schmallenberg virus (SBV) in Sweden was detected by consecutive serological bulk milk surveys conducted before and after the vector season of 2012. Whereas <0.2% of cattle herds tested positive in a first survey in spring 2012, SBV‐specific antibodies were detected in almost 75% of 723 bulk milk samples randomly collected all over the country 6 months later, beyond the 65th northern latitude, and with an observed spatial distribution suggesting multiple introductions of the virus. Circulation of virus was later confirmed by the detection of SBV in malformed lambs and calves starting from November 2012 and January 2013, respectively. These observations suggest SBV circulation starting from July 2012, with a peak in transmission between August and October. A local heterogeneity of within‐herd seroprevalence was found, indicating that SBV‐naïve animals remain also in highly infected areas enabling the re‐emergence of the infection in the coming vector season.     

Supracondylar femur fracture fixation: Mechanical comparison of the 95° condylar side plate and screw versus 95° angled blade plate

The best way to stabilize supracondylar femur fractures remains debatable. Previous studies have compared internal fixation to intramedullary fixation, but none have compared the stiffness characteristics and strength of the 95° angled blade plate (ABP) with the 95° condylar side plate and screw (DCS). 14 synthetic femora were cut in half and the proximal pole of the distal fragment was made secure. A 1 cm gap was made parallel to the femoral condylar weightbearing surface to create an extraarticular supracondylar femur fracture (OTA 33-A3). 7 femora were stabilized with an ABP and 7 with a DCS. Using an MTS compression/torsion servohydraulic testing machine, each femur was tested in 7 modes of loading: (1) axial compression; (2) anterior compression; (3) posterior compression; (4) medial compression; (5) lateral compression; (6) torsion in external rotation; and (7) torsion in internal rotation. The stiffness of the construct in each mode, the "maximum load in axial compression", and the fatigue characteristics in axial compression were measured. The DCS showed a statistically significant greater stiffness in axial compression and average maximal load than the ABP. The fatigue tests revealed no evidence of permanent deformation or loosening of either construct.     

Brain preservation with selective cerebral perfusion for operations requiring circulatory arrest: protection at 25 °C is similar to 18 °C with shorter operating times

Background: Hypothermic circulatory arrest (HCA) is employed for aortic arch and other complex operations, often with selective cerebral perfusion (SCP). Our previous work has demonstrated real-time evidence of improved brain protection using SCP at 18 °C. The purpose of this study was to evaluate the utility of SCP at warmer temperatures (25 °C) and its impact on operating times. Methods: Piglets undergoing cardiopulmonary bypass (CPB) and 60 min of HCA were assigned to three groups: 18 °C without SCP, 18 °C with SCP and 25 °C with SCP (n = 8 animals per group). CPB flows were 100 ml kg⁻¹ min⁻¹ using pH-stat management. SCP flows were 10 ml kg⁻¹ min⁻¹ via the innominate artery. Cerebral oxygenation was monitored using NIRS (near-infrared spectroscopy). A microdialysis probe placed into the cerebral cortex had samples collected every 15 min. Animals were recovered for 4 h after separation from CPB. All data are presented as mean ± standard deviation (SD; p < 0.05, significant). Results: Cerebral oxygenation was preserved during deep and tepid HCA with SCP, in contrast to deep HCA without SCP (p < 0.05). Deep HCA at 18 °C without SCP resulted in significantly elevated brain lactate (p < 0.01) and glycerol (p < 0.01), while the energy substrates glucose (p < 0.001) and pyruvate (p < 0.001) were significantly depleted. These derangements were prevented with SCP at 18 °C and 25 °C. The lactate/pyruvate ratio (L/P) was profoundly elevated following HCA alone (p < 0.001) and remained persistently elevated throughout recovery (p < 0.05). Piglets given SCP during HCA at 18 °C and 25 °C maintained baseline L/P ratios. Mean operating times were significantly shorter in the 25 °C group compared to both 18 °C groups (p < 0.05) without evidence of significant acidemia. Conclusion: HCA results in cerebral hypoxia, energy depletion and ischaemic injury, which are attenuated with the use of SCP at both 18 °C and 25 °C. Procedures performed at 25 °C had significantly shorter operating times while preserving end organs.     

Simulation of total knee arthroplasty in 5° or 7° valgus: A study of gap imbalances and changes in limb and knee alignments from native

This study calculated the frequency of occurrence of gap imbalances between medial and lateral compartments at 0° flexion and within a compartment between 0° and 90° flexion, and changes in limb and knee alignment from native after computer simulation of total knee arthroplasty (TKA) with the knee set in 5° or 7° valgus at 0° flexion. TKA was simulated on 49 3D bone models of native limbs. At 0° flexion, the femoral component was set in 5° or 7° valgus from the anatomic axis of the femur, and the tibial component was set 0° to the tibial anatomic axis. At 90° flexion, internal‐external rotation of the femoral component was set perpendicular to the anteroposterior axis of the trochlear groove (Method 1), parallel to the transepicondylar axis (Method 2), 3° externally rotated to the posterior condylar axis (Method 3), and gap‐balanced to the tibial resection at 0° flexion (Method 4). For 5° and 7° valgus knees, the frequency of occurrence of TKAs (1) with ≥2 mm gap imbalance between compartments at 0° flexion was ≥49%, (2) with ≥2 mm gap imbalance within a compartment between 0° and 90° flexion ranged from 43–69% for Methods 1, 2, and 3, and (3) with ≥2° change in limb and knee alignment from native was ≥47%. Achieving balanced gaps between compartments at 0° flexion may often require soft tissue release. Unbalanced gaps within a compartment between 0° and 90° flexion represent a potential instability which is difficult to surgically correct. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2031–2039, 2017.

     

Photodynamic therapy for esophageal cancer using a 180° windowed esophageal balloon

Although delivery of uniform circumferential light is desirable during photodynamic therapy of advanced esophageal cancer in humans, early esophageal cancer may need only targeted treatment. Studies were performed in the canine esophagus of eight animals to investigate whether use of a “windowed” (shaded) centering balloon would improve targeted illumination of esophageal mucosa for photodynamic therapy. Shaded balloons were developed with a 2-cm-long, 360° or 180° clear “window.” Photofrin 4 mg/Kg was used as the photosensitizer. Light at 630 nm was delivered at 300 J/cm or 600 J/cm. Isotropic probes placed on the balloon wall allowed real-time measurement and verification of relatively uniform light doses delivered to esophageal mucosa during balloon photodynamic therapy. With the windowed balloon, targeted delivery of photodynamic therapy was possible. Using the 180° balloon, mucosa exposed to illumination was destroyed, whereas mucosa protected from light by the balloon shading was undamaged. Healing was complete and strictures did not occur. The shading of the balloon protected normal mucosa and prevents the formation of esophageal strictures. The “windowed” centering balloon provides a technology and technique that allows targeted delivery of uniform light during esophageal PDT. © 1994 Wiley-Liss, Inc.     

Effect of addition of melatonin on liquid storage of ram semen at 4°C

Adding a certain amount of antioxidants to semen extender has been shown to improve semen quality. The aim of present study was to elucidate whether the supplementation of melatonin to the Tris‐based extender (CTR) could enhance the quality of ram spermatozoa during storage at 4°C. Ram semen samples were collected and diluted with CTR extender containing different concentrations (0, 0.05 (M 0.05), 0.1 (M 0.1), 0.2 (M 0.2) or 0.4 (M 0.4) mM) of melatonin. Sperm routine indicators, mitochondrial activity, total antioxidant capacity (T‐AOC) and malondialdehyde (MDA) content were analysed in control and melatonin treatment groups. The higher per cent of motility, plasma membrane integrity, mitochondrial activity and T‐AOC activity was observed in M 0.05, M 0.1 and M 0.2 groups compared to control group at 5 days of storage (p < 0.05), while lower percentage of MDA content was observed among these groups (p < 0.05). In addition, there were no significant differences in acrosome integrity among the control and M 0.05, M 0.1 and M 0.2 groups during the experiment. The above results show that the addition of 0.05, 0.1, 0.2 mM of melatonin is beneficial to the preservation of ram semen during liquid storage at 4°C mainly through antioxidative stress.     

An explorative study on the validity of various definitions of a 2·2°C temperature threshold as warning signal for impending diabetic foot ulceration

Home monitoring of skin temperature is effective to prevent diabetic foot ulceration. We explored the validity of various definitions for the >2·2°C left‐to‐right threshold used as a warning signal for impending ulceration. Twenty patients with diabetes and peripheral neuropathy monitored their skin temperature with an infrared thermometer at the plantar hallux, metatarsal heads, midfoot and heel four times a day for 6 consecutive days. Environmental temperature and walking activity were monitored and associated with foot temperature. The average temperature difference between feet was 0·65°C. At single locations, a left‐to‐right temperature difference of >2·2°C was found 245 times (8·5% of measurements). Confirmation of these above‐threshold readings on the following day was found seven times (0·3%). Corrected for individual left‐to‐right mean foot temperature differences, this reduced to four (0·2%). No ulcers developed in the week after monitoring. Left‐to‐right foot temperature differences were not significantly correlated with walking activity, environmental temperature or time of day. The >2·2°C left‐to‐right foot temperature threshold for impending ulceration is not valid as single measurement, but validity improves to acceptable levels when an above‐threshold temperature difference is confirmed the following day and further improves with individual correction. The threshold is independent of time of day, environmental temperature and walking activity.     

Cold (0°C) ischaemic tolerance of latissimus dorsi free flaps in rats: A macroscopic and morphological study

The purpose of this study was to define the cold (0°C) ischaemic tolerance (CIT) of the latissimus dorsi free flap in inbred rats. Flaps were isolated, stored at 0°C for periods of time ranging from 0 to 120 hr and then revascularised and reperfused for 14 days. Thereafter the CIT was assessed macroscopically, and by light microscopy. Electron microscopy was performed in flaps after 0 and 24 hr of reperfusion following a cold ischaemic interval ranging from 0 to 120 hr. From this preliminary study, it was concluded that the CIT was 48-72 hr.     

Ischial pressure sores: Reconstruction using the perforator‐based reverse flow musculocutaneous 180° propeller flap

The treatment of pressure sores requires soft tissue reconstruction with thick tissue to provide padding of bony prominences and obliterate dead space. Fasciocutaneous flaps may not provide adequate bulk. Propeller flaps (180°) based on perforators from the gluteal artery may be harvested as a reverse flow musculocutaneous flap including a muscle plug to reconstruct deep cavities. Three patients presenting with deep pressure sores required reconstruction of large cavities. In addition to a regular 180° propeller flap, a muscle plug based on a perforator found in the blade of the propeller was used to add bulk to the flap and obliterate the cavity with well‐vascularized tissue. One flap required secondary closure of the donor site due to dehiscence, one hematoma required drainage. All flaps survived completely. No recurrence of osteomyelitis or pressure sores was seen. The 180° propeller flap can be harvested as a reverse flow musculocutaneous flap including a muscle plug in the distal blade. This adds volume which is required to adequately obliterate large cavities in cases of osteomyelitis. This new technique may be useful in other areas as well. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.     

Pre‐oxygenation in healthy volunteers: a comparison of the supine and 45° seated positions*

Pre‐oxygenation in the seated (sitting) position has been associated with better oxygenation. This randomised, cross over study compared oxygenation in the supine position with that in the 45° seated position in 40 young, healthy volunteers. Oxygen was administered through a circle system and tight fitting facemask. Transcutaneous Po ₂ levels were recorded at 10‐s intervals from two measurement points during 4 min of oxygenation in the two positions. The mean (SD) values of 12 measurements taken between the third and fourth minute were recorded. There was no difference in the increase in tissue oxygenation when comparing the supine and seated positions (32.7 (7.3) vs 32.6 (6.7) kPa, respectively). We conclude that there is no evidence that pre‐oxygenation in the 45° seated position improves tissue oxygenation in young healthy volunteers compared with the supine position.     

Chlorogenic acid improves the quality of boar semen subjected to cooled storage at 15°C

The aim of this study was to investigate the effect of chlorogenic acid (ChA) in boar semen stored at 15°C. Twelve ejaculates were processed into insemination doses at different concentrations of ChA (0.0, 1.5, 3.0, 4.0 and 6.0 mg/ml) or vitamin E (200 μl/ml) as positive control. Semen was analysed after 0, 24 and 72 hr of storage. ChA improved (p < .05) sperm motility, acrosome integrity and mitochondrial activity in all periods of storage. Furthermore, after 24 hr of storage, ChA above 1.5 mg/ml supported the sperm viability until 120 min after reheating (p < .05). Both ChA and vitamin E were similarly efficient in increasing the antioxidant capacity of semen, reducing the malondialdehyde levels before and after 72 hr of storage (p < .05). However, with 72 hr of storage, ChA at 3.0 mg/ml improved the mitochondrial activity over vitamin E (p < .05). In conclusion, results suggest that the concentration of 3.2 mg/ml of ChA is the best for semen stored for up to 24 hr. However, for semen stored for a longer period, 6.0 mg/ml or more should be used.