The effect of adding oral dexamethasone to feed alterations on the airway cell inflammatory gene expression in stabled horses affected with recurrent airway obstruction.

BACKGROUND: Chemokine expression in airway epithelium and bronchoalveolar lavage fluid (BALF) cells of horses with recurrent airway obstruction (RAO) is increased. HYPOTHESIS: For RAO-affected horses that are stabled and fed a pelleted ration, the addition of oral dexamethasone further improves pulmonary function and reduces inflammatory gene expression in pulmonary cells. ANIMALS: Twelve RAO-affected horses. METHODS: In a randomized cross-over experiment, the effect of feeding pellets in lieu of hay to stabled, RAO-affected horses was compared with the effect of feeding pellets and administering a 21-day decreasing dose regimen of oral dexamethasone on the expression (by kinetic polymerase chain reaction) of interleukin-8 (IL-8), chemokine (C-X-C motif) ligand 2 (CXCL2), IL-1beta, IL-6, and beta-actin in the BALF cells and of IL-8, CXCL2, 2 IL-1 receptor (IL-1R2), Toll-like receptor 4 (TLR4), and glyceraldehyde 3-phosphate dehydrogenase in the bronchial epithelium 2 days after the final dose. RESULTS: Both treatments reduced airway neutrophilia and breathing efforts but the addition of dexamethasone was associated with fewer treatment failures. Compared with feed changes alone, dexamethasone administration further reduced the expression of IL-8, CXCL2, and IL-1beta in the BALF cells 3.3-, 2.5-, and 4.7-fold, respectively. In the airway epithelium, both treatments were equally efficacious in reducing the expression of IL-8 and CXCL2 expression relative to pretreatment values, but either treatment failed to alter the expression of IL-1R2 and TLR4. CONCLUSIONS AND CLINICAL IMPORTANCE: For a rapid and consistent improvement in pulmonary function and a reduction in inflammatory gene expression of the BALF cells, a decreasing dose of oral dexamethasone in combination with feed alterations is more efficacious for horses that must remain stabled.

Supratip deformity: a closer look.

Supratip deformity, a hallmark of a poorly executed rhinoplasty or an inauspicious healing, continues to plague the novice often and the experts on occasion. A clinical and histopathologic study was conducted to search for the surgical causes of this deformity and its histologic presentation. An organized, logical management program was then developed. Clinically, supratip fullness was observed in both primary (26 of 298 patients; 9 percent) and secondary (40 of 112 patients; 36 percent) rhinoplasty candidates. In primary patients, the deformity was the result of inadequate tip projection (pseudodeformity), an overprojected caudal dorsum, a combination of both, or cephalically oriented lower lateral cartilages. In secondary patients, the deformity was caused by an underresected or overresected caudal dorsum, overresected midvault, underprojected tip (pseudodeformity), or a combination of some of these factors. The histopathologic evaluation demonstrated significant fibrosis in the supratip soft tissue of 14 of 16 patients undergoing secondary rhinoplasty without the injection of triamcinolone acetonide and in only 13 of 23 patients who underwent primary rhinoplasty (p<0.05). A supratip deformity can be eschewed by proper resection of the caudal dorsum, avoidance of dead space, restoration of adequate projection to the nasal tip, and an approximation of the supratip subcutaneous tissue to the underlying cartilage using a supratip suture, hence eliminating the dead space. If the problem is noted shortly after surgery, in the presence of collapsible consistency of the supratip tissue and adequate projection, the treatment is taping the supratip tissue as often as it is practical. If no favorable response is elicited in 6 to 8 weeks, thejudicious injection of a small amount of triamcinolone acetonide (0.2 to 0.4 cc of 20 mg/cc) in the deep subcutaneous tissue (not in the dermis) is done. The injection is repeated in 4-week intervals until the desired effect is achieved. If supratip fullness is the consequence of inadequate cartilage resection or inadequate tip projection, surgical correction is needed. The recalcitrant soft-tissue excess in the supratip area is resected, and the subcutaneous soft tissue is approximated to the underlying cartilage. If the dorsum was previously overresected, a cartilage graft to the caudal dorsum or midvault will create an optimal dorsal frame and reduce the potential for a recurrent supratip deformity.

Ear projection and the posterior auricular muscle insertion.

Prominent ears is a common congenital anomaly affecting approximately 5 percent of the general population. The etiology has been attributed to three basic deformities in the ear structure: valgus of the concha with a cranioauricular angle greater than 40 degrees, underfolding of the anthelix, and rarely, hypertrophy of the concha. It is believed that by virtue of its insertion onto the ponticulus, the cranial surface of the concha, the posterior auricular muscle may function to pull the auricle back toward the head. A proximally (anteromedially) displaced insertion site would decrease the length of the effective momentum of the muscle, leading to protrusion of the auricle. This study was conducted to determine if indeed a relationship between the posterior muscle insertion site and ear projection could be established clinically by measuring these parameters intraoperatively in patients presenting for otoplasty and in patients without prominent ears who required conchal cartilage grafts for other procedures.

Yucatan pig: an optimal hairless model for a true random cutaneous flap.

Porcine models have been used extensively for skin flap research because of the established similarity between the cutaneous blood supply of the swine and humans. The Yucatan minipig provides an excellent model for researching the properties of random cutaneous flaps, offering several advantages over other breeds of swine. In this study, a total of 67 random cutaneous dorsal flank flaps measuring 4 x 14 cm were raised on nine Yucatan minipigs. The mean survival length (10.03 +/- 1.60 cm) of the nondelayed flaps was greater than others reported in the literature. The well-defined plane between the subcutaneous tissue and the panniculus carnosus facilitated flap elevation consistently above the level of the panniculus carnosus thereby ensuring the creation of a true random cutaneous flap. Furthermore, the hairless nature of the skin, particularly beneficial in studying chemical peels, permits easy visualization and monitoring of any external skin changes. These advantages make the Yucatan minipig a more desirable alternative to other breeds of swine for use in skin flap research.

The fate of preserved autogenous bone graft.

Certain clinical conditions exist in which a section of cranial bone is removed but not immediately replaced at the initial procedure. Preservation of this bone can provide a valuable autogenous donor source for a future reconstructive procedure. The purpose of our study was to compare the volume retention of fresh autogenous bone with that of preserved autogenous bone as inlay and onlay cranial grafts. Two bone grafts were harvested from the skull of 15 adult New Zealand White rabbits. The graft volumes were calculated, and the graft were preserved in a normal saline-antibiotic solution at -20 degrees C. Three months later, during the second procedure, a fresh graft was harvested and then placed in the preexisting occipital defect as an inlay graft. Also at this time, the preserved grafts were placed, one as an inlay graft in the fresh occipital defect and the other as an onlay graft in the frontal region. The animals were sacrificed 3 months later, and the percentage of graft volume retention was determined. The fresh inlay grafts had a mean volume retention of 85.1 percent, while the preserved inlay nad onlay grafts had 61.8 and 75.9 percent mean volume retention, respectively. It is concluded that while fresh cranial autograft remains the "gold standard" for craniofacial reconstruction, preserved autogenous cranial bone is a viable alternative for inlay and onlay grafting of the craniofacial region.

Management of an extensive cervicofacial lymphovenous malformation of the maxillofacial region.

The operative approach to extensive vascular anomalies of the maxillofacial region with significant skeletal involvement demands considerable preoperative planning and orthodontic intervention guided by a creative surgical design. A case of a 17-year-old male with a middle and lower face lymphovenous malformation, requiring a complex orthodontic and surgical approach, is reported here. Details regarding the preoperative examination, orthodontic maneuvering, and the surgical procedures are given. An overview of the classification and clinical implications of craniofacial vascular anomalies is also presented.

Knee function after patellectomy and cruciform repair of the extensor mechanism.

When patellectomy is performed, the objectives should include restoration of a moment arm, centralization of the extensor mechanism, adequate range of motion, and cosmesis. The cruciate repair of the extensor mechanism described in this report has been developed to meet the aforementioned objectives. Eight patients with 12 patellectomies described herein were examined with Cybex testing of the knee at a follow-up period of 18 months to 20 years (mean, 56 months). A four-quadrant tissue dissection of the patellar soft-tissue enclosure was reconstructed in a cruciform pants-over-vest fashion, with the superomedial flap containing the vastus medialis insertion on top. This "soft-tissue" patella attempts to provide a greater moment arm than simpler repairs. This study examines whether this construct restored the torque of extension while concomitantly facilitating centralization of the extensor mechanism. Cybex testing of both knees examined both extensor and flexor function with specific regard to the ratio of extensor to flexor forces. Patients with patellectomies had few subjective complaints, with a mean knee score of 94 (median, 100). The extensor torque was not completely restored and there was a moderate decrease in the quadriceps function, both subjectively and objectively as measured by Cybex testing. The authors also found that in patients with unilateral patellectomies, the ratios of extension to flexion function, a parameter not yet reported in the literature, were significantly different between the normal and patellectomized knees. The same extension to flexion ratios were seen in patients with bilateral patellectomies. Because patients with patellar pathology requiring patellectomy frequently have chronic and bilateral disease, comparative functional evaluation may be difficult.(ABSTRACT TRUNCATED AT 250 WORDS)