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OBJECTIVE To describe an ultrasound-guided technique for central venous catheter placement via the external jugular vein (EJV) in pigs. ANIMALS 96 healthy Landrace–Poland China barrows (approx 16 weeks old with a mean weight of 70 kg). PROCEDURES Pigs were anesthetized. With ultrasound guidance, a needle was inserted into the EJV without a large incision or cutdown procedure. A guidewire was inserted through the needle into the vein. A modified Seldinger technique was used to advance a catheter into the vessel until the tip was in the cranial vena cava near the right atrium. A trocar was used to create a tunnel through the subcutaneous tissues from the catheter insertion site to between the dorsal borders of the scapulae. The free end of the catheter was passed through that tunnel. An extension was attached to the catheter and secured to the skin. Pigs were euthanized and underwent necropsy at completion of the study for which they were catheterized. RESULTS Central venous catheters were successfully placed in all 96 pigs and facilitated collection of serial blood samples with minimal stress. Catheters remained in place for a mean of 6 days (range, 4 to 10 days). Necropsy revealed abscesses along the subcutaneous catheter tract in 9 pigs. Twenty pigs had histologic evidence of phlebitis and fibroplasia in the cranial vena cava. CONCLUSIONS AND CLINICAL RELEVANCE The described technique, in combination with extensive socialization, allowed serial collection of blood samples with minimal stress and restraint and is an alternative to surgical cutdown procedures for catheter placement. (Am J Vet Res 2021;82:760–769)

Chronic wounds such as diabetic foot ulcers and venous leg ulcers are common problems in people suffering from type 2 diabetes. These can cause pain, and nerve damage, eventually leading to foot or leg amputation. These types of wounds are very difficult to treat and sometimes take months or even years to heal because of many possible complications during the process. Allogeneic skin grafting has been used to improve wound healing, but the majority of grafts do not survive several days after being implanted. We have been studying the behavior of fibroblasts and keratinocytes in engineered capillary-like endothelial networks. A dermo-epidermal graft has been implanted in an athymic nude mouse model to assess the integration with the host tissue as well as the wound healing process. To build these networks into a skin graft, a modified inkjet printer was used, which allowed the deposit of human microvascular endothelial cells. Neonatal human dermal fibroblast cells and neonatal human epidermal keratinocytes were manually mixed in the collagen matrix while endothelial cells printed. A full-thickness wound was created at the top of the back of athymic nude mice and the area was covered by the bilayered graft. Mice of the different groups were followed until completion of the specified experimental time line, at which time the animals were humanely euthanized and tissue samples were collected. Wound contraction improved by up to 10% when compared with the control groups. Histological analysis showed the neoskin having similar appearance to the normal skin. Both layers, dermis and epidermis, were present with thicknesses resembling normal skin. Immunohistochemistry analysis showed favorable results proving survival of the implanted cells, and confocal images showed the human cells' location in the samples that were collocated with the bilayer printed skin graft.

In this investigation, the influence of hyperbaric oxygen (HBO) therapy on the survival of a replanted extremity subjected to prolonged warm ischaemia is evaluated. Among the relative contraindications to replantation are prolonged warm ischaemia time, since an obstruction to blood reflow ('no-reflow phenomenon') may occur in amputated parts that are subjected to more than 6h of warm ischaemia. Twenty-three rat hindlimbs were amputated and subjected to 4h of normothermic ischaemia. The average weight of the animals was 500 gm, and re-plantation of the hindlimb was performed by bone fixation followed by microvascular anastomosis of the femoral vessels. Limb re-vascularisation was confirmed at the end of all procedures by the milk test, clinical assessment and pulse oximetry recordings (>90%). Eleven animals served as a control group and no further therapy was instituted, whereas 12 animals served as the study (replantation) group and were subjected to HBO therapy for 3 days postoperatively. The therapy was conducted in a large animal chamber for 90 min at 2.5 ata. Limb survival was assessed by capillary refill upon compression, skin turgor assessment and colour. Confirmation of clinical findings was conducted with daily pulse oximetry readings of >90%. Animals were followed up for 7 days at which point all animals were euthanized or were euthanized earlier if a non-viable limb was present. Two of the 11 limbs in the control group survived following re-plantation, whereas eight of the 12 limbs in the experimental HBO group survived at least 7 days following replantation. This difference was statistically significant (p=0.0361) using chi-square analysis and Fisher's exact test. Although re-plantation of an amputated extremity after prolonged warm ischaemia is considered a relative contraindication due to the possibility of poor outcomes, our results indicate that the window for replantation may be increased if adjunctive HBO therapy is employed in the postoperative period.

Aims: Neutrophil adhesion molecule CD11b and reactive oxygen species (ROS) are neutrophil activation markers for evaluating the functional activity of neutrophils. The aim of this study was to determine if neutrophils are activated in murine AIDS and/or chronic ethanol consumption and if neutrophil CD11b expression and ROS production vary when progressive retrovirus infection occurs. Methods: Four groups were studied: control, murine AIDS, ethanol and ethanol plus murine AIDS. Neutrophil activation was assessed by CD11b expression and ROS production using flow cytometry. Results: We found that neutrophils lost their responsiveness to fMLP due to retrovirus or ethanol exposure. In the murine AIDS group, neutrophil CD11b expression was up-regulated along with a significant increase in ROS after 1 month of retroviral infection. After 2 months, neutrophil CD11b and ROS decreased. Howeve r, neutrophil CD11b expression further increased after 3 months. In the ethanol consumption group, neutrophil CD11b expression was down-regulated after 2 months, whereas ROS production increased in the first and third months. In the murine AIDS plus ethanol group, there were significant increases in both ROS and CD11b expression during the 3-month observation period. Conclusions: These findings suggest that neutrophil function is impaired by LP-BM5 retrovirus infection and/or chronic ethanol consumption. The pattern of neutro- phil CD11b expression and ROS production might help to predict the stage of murine AIDS. Ethanol may further compromise neutrophil function in AIDS.

Diabetics suffer from many complications including a prothrombotic condition. Activated platelet membrane provides an anchor, phosphatidylserine, for the attachment of the prothrombinase complex, which allows increased thrombin formation. This study aimed to further elucidate the interrelationship between coagulation proteins and activated platelets in type 2 diabetic blood. We found that there was a significant increase (30×) in thrombin activity in the type 2 diabetic (ZDF) blood as compared to age-matched (ZL) controls (p

Surgical treatment of chronic osteomyelitis requires aggressive debridement followed by wound coverage and obliteration of dead space with vascularized tissue. Controversy remains as to the effectiveness of different tissue types in achieving these goals and in the eradication of disease.Chronic osteomyelitis was induced in 26 goat tibias using Staphylococcus aureus as an infecting inoculum. In a single stage, debridement followed by reconstruction using either a muscle flap (n = 13) or a fasciocutaneous flap (n = 13) was performed. Flap donor sites were closed primarily and antibiotics were given for 5 days postoperatively. Daily clinical evaluation for 1 year was performed and monthly radiographs were obtained for 9 months and 1 year after the reconstruction.Twenty-five flaps survived completely, and one nonmuscle flap underwent partial flap loss following a period of venous congestion. There were no postoperative complications in the muscle flap group. Two goats (15 percent) in the nonmuscle group developed superficial wounds in the immediate postoperative period that resolved with conservative management. No limbs had recurrent osteomyelitis wounds at 1 year of clinical follow-up examination. Radiographic evidence of osteomyelitis was present in two goats (15 percent) in the muscle group and one goat (8 percent) in the nonmuscle group. There was no statistically significant difference in the incidence of recurrent osteomyelitis between the groups by clinical and radiographic assessment.The findings in this study demonstrate that vascularized tissue flaps in the form of muscle or nonmuscle flaps provide viable options for wound coverage of osteomyelitis defects following adequate surgical debridement.

The recovery from cardiac surgery and cardiopulmonary bypass can be complicated by an acute inflammatory response. Circulating blood through an extracorporeal circuit (ECC) contributes to this complication. Perfluorocarbon-based blood substitutes (PFCs) are under investigation for use as a component of the ECC "prime" solution, because PFCs increase the oxygen-carrying capacity of the diluted blood. Some PFCs may provide the additional benefit of attenuating the ECC-induced inflammatory response. Earlier, we reported that perflubron emulsion (PFE, Alliance Pharmaceutical Corp.) reduced neutrophil (PMN) activation in vivo. However, the potential of PFE to reduce ECC-induced PMN activation has not been investigated. In this study, we used a small-scale ECC model to quantify the extent of PMN activation during circulation and to examine if PFE treatment attenuated PMN activation. ECC circuits were filled with a mixture of blood and Plasmalyte. Two groups were studied: an untreated group containing blood plus PlasmaLyte and a treated group in which some of the Plasmalyte was substituted with PFE (4.5 g/100 ml). Hematology and measures of whole blood PMN activation were made from blood samples taken periodically throughout the 120-min ECC circulation period. We found, for the untreated group, a significant decrease in the number of circulating PMNs and an increase in PMN activation with time. PMN activation was demonstrated as a significant increase in the expression of the PMN adhesion protein CD11b (P < 0.05) and an increase in PMN oxygen free radical production (reactive oxygen species (ROS)). After 120 min of circulation, the PMNs remained capable of a significant response to a second inflammatory stimulus, but PFE treatment significantly attenuated the fMLP-induced increase in PMN ROS at t = 120 min (P < 0.05). These results suggest that PFE may have dual utility in cardiac surgery, to increase oxygen delivery and to serve as an antiinflammatory agent.