Arthrodesis of the equine proximal interphalangeal joint: a biomechanical comparison of 3-Hole 4.5 mm locking compression plate and 3-hole 4.5 mm narrow dynamic compression plate, with two transarticular 5.5 mm cortex screws

Objectives To compare the biomechanical characteristics of 2 arthrodesis techniques for the equine proximal interphalangeal joint (PIP) using either a 3-hole 4.5 mm locking compression plate (LCP) or 3-hole 4.5 mm narrow dynamic compression plate (DCP), both with 2 transarticular 5.5 mm cortex screws. Study Design Experimental. Sample Population Cadaveric adult equine forelimbs (*n=6 pairs). Methods For each forelimb pair, 1 limb was randomly assigned to 1 of 2 treatment groups and the contralateral limb by default to the other treatment group. Construct stiffness, gap formation across the PIP joint, and rotation about the PIP joint were determined for each construct before cyclic axial loading and after each of four, 5000 cycle loading regimens. After the 20,000 cycle axial loading regimen, each construct was loaded to failure. Results There were no significant differences in construct stiffness, gap formation, or sagittal plane rotation between the LCP and DCP treatment groups at any of the measured time points. Conclusion Biomechanically, fixation of the equine PIP joint with a 3-hole 4.5 mm LCP is equivalent to fixation with a 3-hole 4.5 mm narrow DCP under the test conditions used.

In vitro evidence for immune evasion activity by human plasmin associated to pathogenic Leptospira interrogans

Leptospirosis is a widespread re-emerging zoonosis of human and veterinary concern. It has been shown that virulent leptospires protect themselves against the host`s innate immune system, a strategy that allows the bacteria to reach immunologically safe environments. Although extensive studies on host pathogen interactions have been performed, little is known on how leptospires deal with host immune attack. In a previous work, we demonstrated the ability of leptospires to bind human plasminogen (PLC), that after treatment with activators, conferred plasmin (PLA) activity on the bacteria surface. In this study, we show that the PLA activity associated to the outer surface of Leptospira could interfere with the host immune attack by conferring some evasion advantage during infection. We demonstrate that PLA-coated leptospires interfere with complement Ob and IgG depositions on the bacterial surface, probably through the degradation of these components, thus diminishing opsonization process. Similar decrease on the deposition was observed when normal and immune sera from patients diagnosed with leptospirosis were employed as a source of IgG. We believe that decreasing opsonization by PLA generation might be an important aspect of the leptospiral immune escape strategy and survival. To our knowledge, this is the first proteolytic activity of plasmin associated-Leptospira related to anti-opsonic properties reported to date. (C) 2011 Elsevier Ltd. All rights reserved.

Transdermal Pharmacology of Small Molecule Cyclic C5a Antagonists

Overproduction or underregulation of the proinflammatory complement component C5a has been implicated in numerous immune and inflammatory conditions. Therefore, targeting the C5a receptor (C5aR) has become an innovative strategy for antiinflammatory drug development. The novel cyclic peptide C5aR antagonist, AcF-[OP(D-Cha)WR] (PMX53), attenuates injury in numerous animal models of inflammation following intravenous, subcutaneous, intraperitoneal, and oral administration. In the present study the transdermal pharmacology of PMX53 and three analogs designed with increased lipophilicity, hydrocinnamate-[OP(D-Cha)WCit] (PMX200), AcF-[OP(D-Cha)WCit] (PMX201) and hydrocinnamate-[OP(D-Cha)WR] (PMX205), have been examined in order to assess their transdermal permeability and inhibitory effect on C5a-mediated lipopolysaccharide (LPS)-induced systemic responses. In the rat, PMX53, PMX201, and PMX205, were bioavailable following topical dermal administration (10 mg/50 cm(2) site/rat). All analogs functionally antagonized neutropenia and hypotension induced by systemic challenge with LPS (I mg/kg i.v.). Interestingly, PMX200 attenuated LPS-induced neutropenia more effectively than other analogs, despite undetectable (< 5 ng/ml) circulating levels following topical administration. In conclusion, we have demonstrated that cyclic peptide C5aR antagonists can penetrate transdermally sufficiently to have systemic effects. However, increasing lipophilicity in these compounds did not result in increased blood levels. Nonetheless, topical application of C5aR antagonists produced circulating levels of the drugs that antagonized the LPS-induced systemic responses of neutropenia and hypotension. This suggests that these small-molecule C5aR antagonists may be developed for topical administration for the treatment of local and systemic inflammatory conditions in the human and veterinary pharmaceutical markets.

Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.

Assessment of linear measurements of bone for implant sites in the presence of metallic artefacts using cone beam computed tomography and multislice computed tomography

The objective was to evaluate the influence of dental metallic artefacts on implant sites using multislice and cone-beam computed tomography techniques. Ten dried human mandibles were scanned twice by each technique, with and without dental metallic artefacts. Metallic restorations were placed at the top of the alveolar ridge adjacent to the mental foramen region for the second scanning. Linear measurements (thickness and height) for each cross-section were performed by a single examiner using computer software. All mandibles were analysed at both the right and the left mental foramen regions. For the multislice technique, dental metallic artefact produced an increase of 5% in bone thickness and a reduction of 6% in bone height; no significant differences (p > 0.05) were detected when comparing measurements performed with and without metallic artefacts. With respect to the cone-beam technique, dental metallic artefact produced an increase of 6% in bone thickness and a reduction of 0.68% in bone height. No significant differences (p > 0.05) were observed when comparing measurements performed with and without metallic artefacts. The presence of dental metallic artefacts did not alter the linear measurements obtained with both techniques, although its presence made the location of the alveolar bone crest more difficult.

Education's role in economic development and in assisting the poor

Much faith has been put in the increased supply of education as a means to promote national economic development and as a way to assist the poor and the disadvantaged. However, the benefits that nations can obtain by increasing the level of education of their workforce depends on the availability of other forms of capital to complement the use of its educated workforce in production. Generally, less developed nations are lacking in complementary capital compared to more developed ones and it is appropriate for less developed countries to spend relatively less on education. The contribution of education to economic growth depends on a nation’s stage of economic development. It is only when a nation becomes relatively developed that education becomes a major contributor to economic growth. It is possible for less developed nations to retard their economic growth by favouring investment in educational capital rather than other forms of capital. Easy access to education is often portrayed as a powerful force for assisting the poor and the disadvantaged. Several reasons are given here as to why it may not be so effective in assisting the poor and in promoting greater income equality even though the aim is a worthy one. Also, an economic argument is presented in favour of special education for the physically and mentally handicapped. This paper is not intended to belittle the contribution of education to economic development nor to devalue the ideal of making basic education available to all. Instead, it is intended as an antidote to inflated claims about the ability of greater investment in education to promote economic growth and about the ability of more widespread access to education to reduce poverty and decrease income inequality.

Biomechanical and Microscopic Response of Bone to Titanium Implants in the Presence of Inorganic Grafts

This study evaluated the biomechanical and microscopic response of previously grafted bone to titanium implants. The lower incisors of 16 rabbits were surgically extracted, and bilateral perforations communicating with the remaining sockets were created distally. A socket/perforation defect on each mandible was chosen at random to be immediately filled with a xenogenic graft, whereas the contralateral perforation was left to heal naturally and served as a paired control. After 60 days, titanium implants were installed in the previously operated areas. After periods of 2 and 6 months, the animals were killed, and the force necessary to retrieve implants as well as the bone-implant contact (BIC) and bone mass (BM) were quantified and statistically compared by 2-way analysis of variance and Tukey`s test (alpha = .05). No significant differences in removal torque were observed, either by time or by treatment condition. Differences in BIC and BM between experimental and control groups were not statistically significant through the intervals studied (P < .05). The presence of a xenogenic graft did not influence the microscopic tissue response to titanium implants or fixation into newly formed or mature bone.

Management of a permanent tooth after trauma to deciduous predecessor: an evaluation by cone-beam computed tomography

Impaction of permanent teeth represents a clinical challenge with regard to diagnosis, treatment plan, and prognosis. There is a close relationship between deciduous teeth and permanent teeth germ, and any injury in the deciduous dentition may influence the permanent teeth eruption. The extent of the damage caused to the permanent teeth germ depends on the patient age at the time of injury, type of trauma, severity, and direction of the impact. Conventional radiographic images are frequently used for diagnosis; however, recent developments in three-dimensional (3D) imaging systems have enabled dentistry to visualize structural changes effectively, with better contrast and more details, close to the reality. The cone-beam computed tomography (CBCT) has been used in the diagnosis and treatment plan of these impacted teeth. The purpose of the present case report is to describe a successful conservative management of a retained permanent maxillary lateral incisor with delayed root development after a trauma through the deciduous predecessor in a 9 year-old patient. After clinical and radiographic examination, a CBCT examination of the maxilla was requested to complement the diagnosis, providing an accurate 3D position of the retained tooth and its relationship to adjacent structures. The proposed treatment plan was the surgical exposure and orthodontic traction of the retained tooth. The lateral incisor spontaneously erupted after 6 months. Therefore, this case report suggests that permanent teeth with incomplete root formation have a great potential for spontaneous eruption because no tooth malposition or mechanical obstacles are observed.

Predictable drill-free screw positioning with a graduated 3-dimensional radiographic-surgical guide: A preliminary report

Introduction: Mini-implants are placed in restricted sites, requiring an accurate surgical technique. However, no systematic study has quantified technique accuracy to reliably predict the surgical risks. Therefore, a graduated 3-dimensional radiographic-surgical guide (G-RSG) was proposed, and its inaccuracy and risk index (RI) were estimated. Methods: The sample consisted of 6 subjects (4 male, 2 female), who used mini-implant anchorage. Ten drill-free screws (DFS) were placed by using the G-RSG. The central point of the mesiodistal septum width (SW) was the selected implant site on the presurgical radiograph. The distances between DFS and the adjacent teeth (5-DFS and 6-DFS) were measured to evaluate screw centralization and inaccuracy degree (ID). These distances were statistically compared by independent t tests, and inaccuracy was determined by the expression ID = (5-DFS-6-DFS)/2, which represents deviation of the mini-implant`s final position regarding the central point initially selected. Then SW, ID, and screw diameter (SO) were combined to estimate the surgical risk with RI expressed by RI = SO/SW-ID. Results: The 5-DFS and 6-DFS distances were not significantly different. The ID of the G-RSG was 0.17 mm. The low ID ensured a safe RI (<1) in spite of the restricted SW. Conclusions: The G-RSG accuracy allowed fine prediction of the final DFS position in the inter-radicular septum, with a low RI, which is a helpful tool to estimate surgical risks. (Am J Orthod Dentofacial Orthop 2009; 136: 722-35)

Histological and molecular temporomandibular joint analyses after mandibular advancement surgery: study in minipigs

Objectives. The objective of this study was to elucidate the changes occurring in the temporomandibular joint (TMJ) after surgical mandibular advancement with different fixation techniques: bicortical screws (rigid fixation) and miniplates (semi-rigid fixation). Study design. Eighteen minipigs were equally and randomly divided into 3 groups: Group I (control), nonoperated animals; Group II, animals submitted to surgical advancement surgery and osteosynthesis by bicortical screws; and Group III, animals submitted to surgical advancement surgery and osteosynthesis by miniplates. Four months after the surgeries, the presence of interleukin (IL)-6 and IL-10 in synovial fluid samples was assessed in ELISA experiments. TMJs were histologically prepared. Results. Higher levels of IL-10 (P = .0436) were found for Group II. Descriptive histological analysis was compatible with the ELISA findings. Conclusions. Rigid fixation evokes more pronounced signs of bone remodeling in the TMJ, whereas malleable fixation promotes a more intense inflammatory activity. Therefore, rigid fixation seems to transmit a higher impact of postoperative masticatory forces to the TMJ.

Two-dimensional radiographic and clinical references of the tooth crown for orthodontic mini-implant insertion: A guide-free technique

Objective. This study evaluated the reliability of tooth-crown radiographic references to aid in orthodontic mini-implant insertion and showed an insertion technique based on these references. Study design. The sample consisted of 213 interradicular septa evaluated in 53 bitewing radiographs. The proximal contour of adjacent tooth crowns was used to define septum width and its midpoint was linked to the interdental contact point to determine septum midline (SML). The distances from SML to mesial and distal teeth were measured and compared to evaluate SML centralization degree in 2 different septum heights. Results. The mesial and distal distances were not statistically different in the midpoint of the septum height, but they were different at the apical septum height. Conclusions. The tooth-crown radiographic references determine a high centralization degree of the SML on which an insertion site could be defined. The greater SML centralization degree was observed at the coronal septum area. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:e8-e16)

Bite force, electromyography, and mandible mobility during the 6-month period after surgical treatment for isolated fractures of the zygomatico-orbital complex

Objective. The aim of this study was to identify the behavior of masticatory muscles after fractures of the zygomatico-orbital complex (ZOC) and subsequent surgical treatment, by using analyses of bite force, electromyography (EMG), and mandible mobility during a 6-month period after surgery. Study design. Five patients with fractured ZOCs treated surgically by using an intraoral approach and fixation exclusively in the region of the zygomaticomaxillary buttress were evaluated. The control group included 12 other patients. During postoperative follow-up, bite force, mandible mobility, and EMG analysis of the masticatory muscles were evaluated. Results. There was an increase in bite force with time, but a decline in EMG activity during the same period. In the mandible mobility analysis, only maximum mouth-opening values increased significantly after the surgical treatment. Conclusions. The masticatory musculature, according to bite force and EMG, returned to its normal condition by the second month after surgery, and maximum mouth opening was observed after the first month. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:e1-e7)

Bone repair in mandibular body osteotomy after using 2.0 miniplate system - histological and histometric analysis in dogs

The objective of this study was to evaluate the bone repair along a mandibular body osteotomy after using a 2.0 miniplate system. Nine adult mongrel dogs were subjected to unilateral continuous defect through an osteotomy between the mandibular 3rd and 4th premolars. Two four-hole miniplates were placed in accordance with the Arbeitgeimeinschaft fur Osteosynthesefragen Manual. Miniplates adapted to the alveolar processes were fixed monocortically with 6.0-mm-length titanium alloy self-tapping screws, whereas miniplates placed near the mandible bases were fixed bicortically. At 2, 6 and 12 weeks, three dogs were sacrificed per period, and the osteotomy sites were removed, divided into three thirds (Tension Third, TT; Intermediary Third, IT; Compression Third, CT) and prepared for conventional and polarized light microscopy. At 6 weeks, while the CT repaired faster and showed bone union by woven bone formation, the TT and IT exhibited a ligament-like fibrous connective tissue inserted in, and connecting, newly formed woven bone overlying the parent lamellar bone edges. At 12 weeks, bone repair took place at all thirds. Histometrically, proportions of newly formed bone did not alter at TT, IT and CT, whereas significantly enhanced bone formation was observed for the 12-week group, irrespective of the third. The results demonstrated that although the method used to stabilize the mandibular osteotomy allowed bone repair to occur, differences in the dynamics of bone healing may take place along the osteotomy site, depending on the action of tension and compression forces generated by masticatory muscles.

Variations in cone photoreceptor abundance and the visual ecology of birds

The relative abundance and topographical distribution of retinal cone photoreceptors was measured in 19 bird species to identify possible correlations between photoreceptor complement and visual ecology. In contrast to previous studies, all five types of cone photoreceptor were distinguished, using bright field and epifluorescent light microscopy, in four retinal quadrants. Land birds tended to show either posterior dorsal to anterior ventral or anterior dorsal to posterior ventral gradients in cone photoreceptor distribution, fundus coloration and oil droplet pigmentation across the retina. Marine birds tended to show dorsal to ventral gradients instead. Statistical analyses showed that the proportions of the different cone types varied significantly across the retinae of all species investigated. Cluster analysis was performed on the data to identify groups or clusters of species on the basis of their oil droplet complement. Using the absolute percentages of each oil droplet type in each quadrant for the analysis produced clusters that tended to reflect phylogenetic relatedness between species rather than similarities in their visual ecology. Repeating the analysis after subtracting the mean percentage of a given oil droplet type across the whole retina (the 'eye mean') from the percentage of that oil droplet type in each quadrant, i.e. to give a measure of the variation about the mean, resulted in clusters that reflected diet, feeding behaviour and habitat to a greater extent than phylogeny.

Uterine preservation or hysterectomy at sacrospinous colpopexy for uterovaginal prolapse

This study retrospectively compared 34 women who had a sacrospinous hysteropexy and 36 who had a vaginal hysterectomy and sacrospinous fixation for symptomatic uterine prolapse. All women underwent independent review and examination, with a mean follow-up of 36 months in the hysterectomy group and 26 months in the hysteropexy group.  The subjective success rate was 86% in the hysterectomy group and 78% in the hysteropexy group (P = 0.70). The objective success rate was 72% and 74%, respectively (P = 1.00). The patient-determined satisfaction rate was 86% in the hysterectomy group and 85% in the hysteropexy group (P = 1.00). The operating time in the hysterectomy group was 91 minutes, compared to 59 minutes in the hysteropexy group (P