Farmakokinetika eprinomektina u ovaca nakon potkožne primjene.

The pharmacokinetics of eprinomectin was determined in lactating sheep following subcutaneous administration at a dose rate of 0.2 mg kg-1. The eprinomectin concentration in plasma was determined using High Performance Liquid Chromatography (HPLC) with a fluorescence detector. The kinetics of plasma concentrations were analysed using the non-compartment model. The maximum plasma concentration of 24.44 ng/mL occurred 2 days post-administration. Following subcutaneous administration of eprinomectin in sheep, the value of plasma elimination half-life, the area under the plasma concentration time curve (AUC) and mean residence time (MRT) were 388.52 ± 0.25 h. 4282.10 ng.h/mL and 374.50 h, respectively. The values of V (area), Vd(ss) and Cl(B) were 20.50 mL/kg, 13.70 mL/kg and 0.04 mL/h/kg, respectively. This study demonstrates that subcutaneous administration of eprinomectin led to higher bioavailability and longer mean residence time with a lower dose than a pour-on application, and that an injectable formulation may be applied in lactating sheep with zero withdrawal period.Farmakokinetika eprinomektina određivana je u ovaca u laktaciji nakon potkožne primjene u dozi od 0,2 mg/kg. Njegova koncentracija u plazmi utvrđena je visoko učinkovitom tekućinskom kromatografijom s fluorescentnim detektorom. Kinetika koncentracija u plazmi analizirana je na osnovi modela bez odjeljaka. Najveća koncentracija u plazmi od 24,44 ng/mL dokazana je dva dana nakon primjene. Poluživot eliminacije iz plazme iznosio je 388,52 ± 0,25 sati, površina ispod krivulje koncentracije u plazmi (AUC) 4282,10 ng/h/mL, a prosječno vrijeme zadržavanja iznosilo je 374,50 sati. Vrijednost prividnog volumena raspodjele, Vd(area), iznosila je 20,50 mL/kg, prosječni vidljivi volumen raspodjele, Vd(ss), 13,70 mL/kg, a ukupni klirens 0,04 mL/sat/kg. Istraživanje je pokazalo da potkožna primjena eprinomektina pruža veću bioraspoloživost, duže vrijeme zadržavanja s manjom dozom u odnosu na veliku te da se injekcijska formulacija može primijeniti u ovaca u laktaciji

Correlation and comparison of Risser sign versus bone age determination (TW3) between children with and without scoliosis in Korean population

<p>Abstract</p> <p>Background</p> <p>Most studies comparing the Risser staging for skeletal maturity are representing the American or European standards which are not always applicable to Asian population who have relatively less height and body mass. There is no article available that compares the Risser sign and bone age correlation between patients with idiopathic scoliosis and patients without scoliosis.</p> <p>Materials and methods</p> <p>To analyze and compare the skeletal age with the Risser sign between scoliosis and non-scoliosis group, a cross-sectional study was done in 418 scoliosis (untreated, bracing or surgically) and 256 non-scoliosis children of Korean origin. Relationship was found in both groups using Pearson correlation test.</p> <p>Results</p> <p>In scoliosis group, Pearson correlation exhibited significant correlation (p < 0.01) between Risser sign and chronological age (r²= 0.791 for girls, 0.787 for boys) and Risser sign and TW3 age (r²= 0.718 for girls, 0.785 for boys). Non-scoliosis group also showed significant relationship (p < 0.01) between Risser sign and chronological age (r²= 0.893 for girls, 0.879 for boys) and Risser sign and TW3 age (r²= 0.913 for girls, 0.895 for boys). Similarly, comparing Cobb angles of each patient according to their Risser staging, exhibited that if scoliosis remains untreated Cobb angle will increase with the increase in their Risser staging (r²= 0.363 for girls, 0.443 for boys; p < 0.01).</p> <p>Conclusion</p> <p>Our results showed that chronological age is equally as reliable as skeletal age method to compare with Risser sign, and therefore, we do not mean to imply that only the Risser sign compared with skeletal age should be considered in the decision making in idiopathic as well as non-scoliosis patients of Korean ethnicity. Concomitant indicators such as menarchal period, secondary sex characteristics, and recent growth pattern will likely reinforce our data comparing Risser sign with skeletal age in decision making.</p

Intraoperative blood loss during different stages of scoliosis surgery: A prospective study

<p>Abstract</p> <p>Background</p> <p>There are a number of reasons for intraoperative blood loss during scoliosis surgery based on the type of approach, type of disease, osteopenia, and patient blood profile. However, no studies have investigated bleeding patterns according to the stage of the operation. The objective of this prospective study was to identify intraoperative bleeding patterns in different stages of scoliosis surgery.</p> <p>Methods</p> <p>We prospectively analyzed the estimated blood loss (EBL) and operation time over four stages of scoliosis surgery in 44 patients. The patients were divided into three groups: adolescent idiopathic (group 1), spastic neuromuscular (group 2) and paralytic neuromuscular (group 3). The per-level EBL and operation times of the groups were compared on a stage-by-stage basis. The bone marrow density (BMD) of each patient was also obtained, and the relationship between per-level EBL and BMD was compared using regression analysis.</p> <p>Results</p> <p>Per-level operation time was similar across all groups during surgical stage (p > 0.05). Per-level EBL was also similar during the dissection and bone-grafting states (p > 0.05). However, during the screw insertion stage, the per-level EBL was significantly higher in groups 2 and 3 compared to group 1 (p < 0.05). In the correction stage, per-level EBL was highest in group 3 (followed in order by groups 2 and 1) (p < 0.05). Preoperative BMD indicated that group 3 had the lowest bone quality, followed by groups 2 and 1 (in order), but the preoperative blood indices were similar in all groups. The differences in bleeding patterns in the screw insertion and correction stages were attributed to the poor bone quality of groups 2 and 3. Group 3 had the lowest bone quality, which caused loosening of the bone-screw interface during the correction stage and led to more bleeding. Patients with a T-score less than -2.5 showed a risk for high per-level EBL that was nine times higher than those with scores greater than -2.5 (p = 0.003).</p> <p>Conclusions</p> <p>We investigated the blood loss patterns during different stages of scoliosis surgery. Patients with poor BMD showed a risk of blood loss nine times higher than those with good BMD.</p

Epidural cement leakage through pedicle violation after balloon kyphoplasty causing paraparesis in osteoporotic vertebral compression fractures - a report of two cases

Kyphoplasty is advantageous over vertebroplasty in terms of better kyphosis correction and diminished risk of cement extravasations. Literature described cement leakage causing neurological injury mainly after vertebroplasty procedure; only a few case reports show cement leakage with kyphoplasty without neurological injury or proper cause of leakage. We present a report two cases of osteoporotic vertebral compression fracture treated with kyphoplasty and developed cement leakage causing significant neurological injury. In both cases CT scan was the diagnostic tool to identify cause of cement leakage. CT scan exhibited violation of medial pedicle wall causing cement leakage in the spinal canal. Both patients displayed clinical improvement after decompression surgery with or without instrumentation. Retrospectively looking at stored fluoroscopic images, we found that improper position of trocar in AP and lateral view simultaneously while taking entry caused pedicle wall violation. We suggest not to cross medial pedicle wall in AP image throughout the entire procedure and keeping the trocar in the center of pedicle in lateral image would be the most important precaution to prevent such complication. Our case reports adds the neurological complications with kyphoplasty procedure and suggested that along with other precautions described in the literature, entry with trocar along the entire procedure keeping the oval shape of pedicle in mind (under C-arm) will probably help to prevent such complications

Bone quality and growth characteristics of growth plates following limb transplantation between animals of different ages - Results of an experimental study in male syngeneic rats

<p>Abstract</p> <p>Introduction</p> <p>The purpose of this study was to identify graft osteoporosis post transplantation by micro-CT analysis, and the growth potential of growth plates in the transplanted limb.</p> <p>Methods</p> <p>Ten juvenile to juvenile and five juvenile to adult hind limb transplants were performed in male syngeneic Lewis rats. Upper tibial bone density in isochronograft and heterochronograft limbs was measured by 3D micro-CT and compared with that of the opposite non-operated limbs.</p> <p>Results</p> <p>We observed inferior bone quality (p < 0.05) in heterochronografts compared to isochronografts. After transplantation, isochronografts did not exhibit increases in tibial lengths compared to opposite juvenile non-operated tibias (p = 0.66) or heterochronograft tibias (p = 0.61). However, significant differences were observed between heterochrongraft tibial lengths when and opposite adult non operated tibial lengths (p < 0.001).</p> <p>Conclusions</p> <p>Age dependent alterations affect bone quality, resulting in post transplantation osteoporosis in heterochronografts, but not isochronografts. However, the growth plates of transplanted limbs retain their properties of longitudinal growth and continue to grow at the same rate.</p

Two levels above and one level below pedicle screw fixation for the treatment of unstable thoracolumbar fracture with partial or intact neurology

<p>Abstract</p> <p>Background</p> <p>Treatment of unstable thoracolumbar fractures is controversial regarding short or long segment pedicle screw fixation. Although long level fixation is better, it can decrease one motion segment distally, thus increasing load to lower discs.</p> <p>Methods</p> <p>We retrospectively analyzed 31 unstable thoracolumbar fractures with partial or intact neurology. All patients were operated with posterior approach using pedicle screws fixed two levels above and one level below the fracture vertebra. No laminectomy, discectomy or decompression procedure was done. Posterior fusion was achieved in all. Post operative and at final follow-up radiological evaluation was done by measuring the correction and maintenance of kyphotic angle at thoracolumbar junction. Complications were also reported including implant failure.</p> <p>Results</p> <p>Average follow-up was 34 months. All patients had full recovery at final follow-up. Average kyphosis was improved from 26.7° to 4.1° postoperatively and to 6.3° at final follow-up. And mean pain scale was improved from 7.5 to 3.9 postoperatively and to 1.6 at final follow-up, All patients resumed their activity within six months. Only 4 (12%) complications were noted including only one hardware failure.</p> <p>Conclusion</p> <p>Two levels above and one level below pedicle screw fixation in unstable thoracolumbar burst fracture is useful to prevent progressive kyphosis and preserves one motion segment distally.</p