Hyperbaric oxygen therapy. Part 2: application in disease

Objective – Review the mechanisms of action and clinical application of hyperbaric oxygen therapy (HBOT) based on human and veterinary clinical and experimental literature. Data Sources – Pubmed and Veterinary Information Network databases were searched for human and veterinary journal articles on hyperbaric therapy in clinically applicable situations. Historical reference searches on several articles in addition to basic physiologic concepts were also reviewed. Human Data Synthesis – HBOT has gained acceptance as an adjunctive treatment in clinical conditions other than diving‐related injuries, such as select problem wounds and central nervous system diseases, in human medicine. Access to hyperbaric therapy has increased and ongoing research has furthered understanding of the mechanisms and potential therapeutic uses of HBOT. Veterinary Data Synthesis – Several animal models have been utilized to examine the effects of HBOT; primarily rodents (mice, rats) and rabbits but also dogs, cats, and pigs. Data related to animal model research as it pertains to clinical application of HBOT is reviewed. Conclusions – There is a substantial body of literature that has examined the adverse and beneficial effects of HBOT in animal models. As technology becomes more readily available to clinical practice and more clinical trials are performed to define its effectiveness, HBOT may be considered as an additional therapeutic option in many conditions including select problem wounds, spinal cord injury, and cerebral ischemic injury. Understanding the mechanisms by which HBOT exerts its effects will help guide research and use of the modality in clinical patients.     

ULTRASONOGRAPHIC ASSESSMENT OF FRACTURE HEALING AFTER PLATE OSTEOSYNTHESIS

The goals of this study were to assess the ability of ultrasonography (US) to assess uncomplicated fracture healing and to establish normal images. Twenty-two dogs, ranging in age from 6 to 180 months were studied. Body weight ranged from 2.2 to 60 kg. All fractures were treated by plate osteosynthesis. US (B-mode and power Doppler) and radiography were performed until both were consistent with complete healing. B-mode US was performed in all dogs, and power Doppler US in 14. Fracture healing was judged to be complete based on US earlier than when based on radiography. The tissue immediately adjacent to the plate appeared vascularized on power Doppler images at a time when the tissue at the fracture site had a negative power Doppler exam. US appears useful for assessment of primary fracture healing and power Doppler was useful for detecting vascularization at the fracture site in nonhealed fractures. Power Doppler interrogation should be performed away from any metal implant, as a result from an interrogation adjacent to an implant will not reflect actual vascularization at the fracture site.     

Presence of opioid growth factor and its receptor in the normal dog,cat and horse cornea

Objective To determine if opioid growth factor (OGF, [Met⁵]enkephalin) and its specific receptor (OGFr) are present in normal cat, dog and horse cornea. Animals studied Normal dog, cat and horse. Procedure Corneas were obtained from animals euthanized for reasons unrelated to this project. One cornea from each of three normal cats, dogs and horses was evaluated. The right or left cornea from each animal was chosen randomly. Corneas were harvested and placed in corneal storage media for transport to The M.S. Hershey Medical Center of The Pennsylvania State University where immunocytochemistry techniques were used to demonstrate the presence and location of OGF and OGFr. Tissues were rinsed in Sorenson's phosphate buffer, immersed in 20% sucrose in buffer and then snap frozen in isopentane. Corneas were then embedded in OCT medium and 15 µm cryostat sections were created. Presence of OGF was determined by using a polyclonal antibody to [Met⁵]enkephalin and assessing immunoreactivity. OGFr presence was determined by using a previously characterized rabbit polyclonal antibody to the receptor. Results OGF and OGFr were identified in large quantities in the corneal epithelium of all three species. Conclusion Opioid growth factor and its specific receptor are present in the corneal epithelium of normal cats, dogs and horses. OGF is present in the cornea of many species and its presence is theorized to inhibit healing of injured tissue.     

成纤维细胞生长因子（FGFs）对小鼠实验性创伤愈合的作用

实验利用酸性和碱性成纤维细胞生长因子（ａＦＧＦ和ｂＦＧＦ）,分别对小鼠进行实验性创伤修复试验。结果表明,ａＦＧＦ和ｂＦＧＦ对创伤愈合有显著的促进作用,而且ａＦＧＦ的效果优于ｂＦＧＦ。     

Efficacy of nano-hydroxyapatite prepared by an aqueous solution combustion technique in healing bone defects of goat

The present study was undertaken to evaluate porous hydroxyapatite (HAp), the powder of which was prepared by a novel aqueous solution combustion technique, as a bone substitute in healing bone defects in vivo, as assessed by radiologic and histopathologic methods, oxytetracycline labeling, and angiogenic features in Bengal goat. Bone defects were created in the diaphysis of the radius and either not filled (group I) or filled with a HAp strut (group II). The radiologic study in group II showed the presence of unabsorbed implants which acted as a scaffold for new bone growth across the defect, and the quality of healing of the bone defect was almost indistinguishable from the control group, in which the defect was more or less similar, although the newly formed bony tissue was more organized when HAp was used. Histologic methods showed complete normal ossification with development of Haversian canals and well-defined osteoblasts at the periphery in group II, whereas the control group had moderate fibro-collagenization and an adequate amount of marrow material, fat cells, and blood vessels. An oxytetracycline labeling study showed moderate activity of new bone formation with crossing-over of new bone trabeculae along with the presence of resorption cavities in group II, whereas in the control group, the process of new bone formation was active from both ends and the defect site appeared as a homogenous non-fluoroscent area. Angiograms of the animals in the control group showed uniform angiogenesis in the defect site with establishment of trans-transplant angiogenesis, whereas in group II there was complete trans-transplant shunting of blood vessel communication. Porous HAp ceramic prepared by an aqueous combustion technique promoted bone formation over the defect, confirming their biologic osteoconductive property.     

马来亚豪猪中国亚种皮肤伤口无疤痕愈合能力的研究

[目的]研究马来亚豪猪中国亚种皮肤伤口无疤痕愈合方式。[方法]对马来亚豪猪中国亚种的耳部实施贯穿伤及撕裂伤,以7 d为节点拍照记录伤口愈合情况;运用石蜡切片、HE染色等方法对豪猪耳部伤口愈合进展进行组织学观察。[结果]撕裂伤口能够在63 d内以无疤痕的方式愈合,于再生区观察到新生的脂肪组织、真皮、表皮和丰富的毛囊。[结论]该研究结果有助于探明豪猪皮肤创伤无疤痕愈合的机理以及了解动物皮肤损伤修复的机制,可为治愈人的大面积皮肤创伤提供参考。     

Meet the corneal myofibroblast: the role of myofibroblast transformation in corneal wound healing and pathology

In recent years the role of the myofibroblast in corneal wound healing has been extensively studied. The transformation of the corneal keratocyte to the fibroblast and myofibroblast phenotypes is a critical process in normal and pathologic corneal wound healing. This review will introduce this important transformation and its role in corneal wound healing and pathology.     

Application of Exogenous Esterified Hyaluronan to Equine Distal Limb Wounds

The objective of this study was to evaluate the efficacy of topical application of a hyaluronan (HA) derivative in wound healing with respect to the rate of epithelialization, fibroplasia, angiogenesis and contraction, magnitude of the local inflammatory response, local expression of transforming growth factor-β 1 and 3 (TGF-β 1 and 3), tumor necrosis factor-α (TNF-α), and collagen type III deposition. In six healthy adult horses, six full-thickness skin wounds were created on the dorsal aspect of both metacarpi using a sterile template. Sites were sampled at 0, 1, 2, 5, 14, 21, and 35 days following wounding. Wounds on one limb were dressed with commercially available esterified HA fleece under a nonadherent dressing. The opposite limb was covered with the nonadherent dressing alone (control). Images of the most proximal wounds were used to determine the area of total healing and the relative contributions of epithelialization and contraction to healing. At each sample time, a control and treatment biopsy were taken for histological evaluation and special stains. All samples were evaluated for degree of inflammation, fibroplasia and angiogenesis; in situ hybridization for type III collagen, TGFβ1 and 3, and immunohistochemistry for TNF-α. Mean percentages of total wound healing, epithelialization, and wound contraction were not significantly different between control and treatment groups. In treated horses, initial wound expansion was significantly decreased during the first 2 weeks. Mononuclear cell numbers, counted in the granulation tissue, increased in both control and treated limbs over the entire course of the study. However at day 35 the macrophage numbers counted in the treated horses were significantly increased compared with the control limbs (P < .05). Although not statistically significant, relative staining for type III collagen in the treated wounds was less than that of control wounds. Results of the present study do not support a benefit of an exogenous HA-derivative in the healing of distal limb wounds in horses. The shortcomings of the study design are discussed.     

创伤愈合中P物质的免疫组化观察

目的：动态分析创伤愈合中中性粒细胞、成纤维细胞(fibroblast，FB)和P物质(Substance P，SP)阳性细胞的时空分布以及创伤局部SP物质的分布与变化，阐述上述变化与创伤愈合的关系。方法：取家兔皮肤创伤组织进行H．E．、免疫组化染色，分别观察局部组织与细胞的变化。结果：中性粒细胞于创后第1天最高，然后回落；FB在第3天即开始大量增殖，在上皮化接近完成，真皮重建活跃的第7天到达峰值；SP阳性物质在刨伤局部呈现强阳性反应，SP阳性细胞数在创后第1天，第3天，第5天时持续显著上升，维持在较高水平直到第15天后才回落。结论：中性粒细胞在创伤愈合早期起作用，不直接参与创伤修复，FB为刨伤修复的主要细胞，SP参与了创伤愈合的全过程。     

HPLC法测定创伤愈合药喷雾剂中血竭素的含量

建立了高效液相色谱法测定创伤愈合药喷雾剂中血竭素含量的方法。色谱柱为C18柱(5μm,4.6 mm×250 mm),流动相乙腈-0.05 mol/L磷酸二氢钠溶液(50∶50),流速1.0 mL/min,柱温40℃,检测波长440 nm,血竭素在13.07～45.74μg/mL浓度范围内,峰面积与浓度线性关系良好(r=0.9997,n=6),平均加样回收率为98.29%,相对标准偏差为0.67%,血竭素的平均含量为0.01902 mg/mL。本研究所建立的含量测定方法简便、灵敏、准确、稳定,可用于创伤愈合药喷雾剂的质量控制。     

Comparison of two topical treatments on wound healing 7 days after disbudding of calves using thermocautery

ABSTRACT

Aims To compare wound healing 7 days after cautery disbudding of dairy calves treated immediately after disbudding with a traditional antimicrobial spray (OXY) or with a topical anaesthetic gel containing cetrimide, adrenaline and two local anaesthetics, lignocaine and bupivacaine (TA).

Method Eighty-one female dairy calves between 6–8 weeks of age were disbudded using a standard cautery disbudding protocol (sedation, cornual block, and analgesia), with complete removal of the horn bud. After disbudding, the wound on the right and left horn buds within each animal were randomly allocated to receive either OXY or TA. One week after disbudding, wounds were visually assessed for the presence of exudate, necrotic tissue, crust, or granulation tissue which were each assigned a grade from 1–3, where 1?=?no evidence, 2?=?moderate presence; and 3?=?marked presence.

Results At 7 days after disbudding, the prevalence of wounds with exudate or necrotic tissue was very low, and independent of treatment. The odds of a disbudding wound treated with TA being scored as having granulation tissue and was 5.2 (95% CI?=?1.72–15.7) times that of a wound treated with OXY. Conversely, the odds of wounds treated with TA being scored as having crusts was 0.18 (95% CI?=?0.06–0.57) that of a wound treated with OXY. No sign of infection was seen in any calves.

Conclusion and clinical relevance The greater prevalence of granulation tissue and reduction in crusting in disbudding wounds treated with topical anaesthetic gel compared to those treated with the antimicrobial spray suggests that use of the topical anaesthetic gel may speed wound healing compared to using antimicrobial spray. This should be further tested in a larger study undertaken over a longer period.     

The effects of omega-3 fatty acid diet enrichment on wound healing

Omega-3 fatty acids were evaluated to determine how their anti-inflammatory properties affect wound healing. Twelve Beagle dogs were divided into two groups of six. Group I was fed an n-3 fatty acid enriched diet (n-3 FAED) with an n-6 to n-3 fatty acid ratio of 0.3, and group II was fed a control diet (CD) with a ratio of 7.7. Open and sutured cutaneous wounds were created on the trunk of the dog, and evaluated by laser Doppler perfusion imaging, tensiometry, planimetry, histopathology, and eicosanoid content. At 5 days, the n-3 FAED-fed dogs had significantly less epithelialization of the open wounds ( P  = 0.0343) and significantly less oedema in sutured wounds ( P  = 0.015). There were also tendencies of less tissue perfusion ( P  = 0.086), lower PGE₂ levels ( P  = 0.0756) and negative wound contraction in open wounds at 5 days. The n-3 FAED used in this study did not appear to have any outstanding long-term negative effect on wound healing.