Caudal Position Research Articles

Extraperitoneal robot-assisted radical prostatectomy: Comparison with transperitoneal technique

AIM: To determine peri-operative, oncological, functional and safety profiles of extraperitoneal robot-assisted radical prostatectomy(e RARP) vs transperitoneal robot-assisted radical prostatectomy(t RARP) in a single centre.METHODS: A total of 120 consecutive patients underwent 50 e RARP and 70 e RARP operations respectively by the same surgical team. Peri-operative and post-operative outcomes including blood loss, hospitalization, complications(Clavien grade), positive surgical margin(PSM) rates, continence and erectile function were compared. The performance of e RARP required several technical modifications. These included developmentof Retzius' space by balloon insufflation, laparoscopic dissection of lateral extensions of this area; caudal port positioning; cranial digital stripping of peritoneum for sucker port and lodging the bagged prostate specimen adjacent to the lateral assistant port to permit space for urethro-vesical anastomosis.RESULTS: Robotic console times were shorter with e RARP vs t RARP(145.1 min vs 198.3 min, P 0.0001). There were no significant differences in blood loss, PSM rates(e RARP 17.7% vs t RARP 22%) or complications(e RARP 8.5% vs t RARP 8%). A drain was used in all patients after t RARP and in 25/70 e RARP cases. Length of hospital stay was shorter after e RARP(mean 1.94 d vs 3.6 d, P 0.0002). There were no differences between techniques in continence or potency at 6 mo. e RARP required several technical modifications: development of Retzius' space by balloon insufflation, laparoscopic dissection of lateral extensions of this area; caudal port positioning; and lodging the bagged prostate specimen adjacent to the lateral assistant port to permit space for urethro-vesical anastomosis.CONCLUSION: e RARP demonstrated advantages in surgical times, hospital stay and equivalence in PSM rates, complications and functional outcomes. e RARP is a useful alternative to t RARP especially in patients with adhesions, pre-existing inguinal hernias, or those unable to withstand steep Trendelenburg position.

Bilateral efferents from nucleus isthmi to the optic tectum in goldfish (Carassius auratus) are spatially restricted

The projection from nucleus isthmi (NI) to the optic tectum (OT) was investigated in the goldfish, Carassius auratus, by retrograde transport of biocytin applied at various sites in a tectal lobe. In previous studies, this projection is described as predominantly from the ipsilateral NI and maps topographically along the approximate rostrocaudal axis of both brain areas. However, the rostromedial tectal lobe, the tectal region representing the binocular visual field, receives afferents from both the ipsilateral and the contralateral NI. The contralateral isthmic neurons are found at the most caudal position in NI and are not topographic with the tectum. The bilateral projection from NI to the tectum may play a role in functions requiring the coordination of both eyes.

Serotonin 2C receptor alternative splicing in a spinal cord injury model

Spinal cord injury can have debilitating consequences, commonly resulting in motor dysfunction below the lesion site and the development of chronic pain syndromes. The serotonin pathway is important for inhibiting noxious stimuli and facilitating motor function after spinal cord injury. The serotonin 2C receptor (5HTR2C) has several characteristic features, and is regulated by the amount of serotonin 2C receptor as well as RNA editing and alternative splicing. In this study, we used a rat model of spinal contusion injury to investigate the relationship between the pain threshold and 5HTR2C alternative splicing. The pain threshold was assessed using mechanical stimulation with von Frey filaments. We then used real-time PCR to examine the RNA levels of 5HTR2C in three sections of the spinal cord: the rostral, injury-core, and caudal positions. On postoperative day 12, the pain threshold in injured rats was significantly reduced compared with sham-operated and naïve rats. The total 5HTR2C levels were significantly lower in injured rats than in naïve rats at all positions, and significantly lower in injured rats compared with sham-operated rats at injury-core and caudal positions. The ratio of exon Vb-skipped nonfunctional 5HTR2C mRNA to total 5HTR2C was significantly higher in injured rats compared with naïve rats at the injury-core and caudal positions, and significantly higher in injured rats compared with sham-operated rats at the caudal position. These results indicate that spinal contusion injury, which causes neuropathic pain, induces serotonergic dysfunction. This dysfunction appears to be mediated by decreased 5HTR2C mRNA expression, and alternative splicing. These results confirm the importance of considering splice variants when examining 5HTR2C.

Is Laryngeal Descent Associated With Increased Risk for Obstructive Sleep Apnea?

A lower (more caudal) position of the larynx may result in a longer collapsible segment of the upper airway. One could thus hypothesize that the lower the larynx the greater the risk for obstructive sleep apnea (OSA). To test this hypothesis, we measured the upper airway length to the level of the vocal cord and the horizontal and vertical segments of the supralaryngeal vocal cord tract (SVT) using multislice CT scan in Japanese patients with OSA. We recruited 249 consecutive patients who had polysomnography for suspected OSA (age, 47.8 ± 14.8 years; BMI, 24.8 ± 4.3 kg/m(2)). Using CT images, we measured airway length (AL), airway length to vocal cord (ALVC), ALVC-AL, horizontal segment of SVT (SVTH), and vertical segment of SVT (SVTV). The ratio SVTR (SVTH to SVTV) was calculated. The correlation between these measurements and age, BMI, and AHI were evaluated. Men had a longer ALVC than women. AL, ALVC, and SVTR were significantly correlated with age and AHI in all patients. Logistic regression analysis showed that ALVC > 0.24 (OR, 4.2; CI, 2.3-7.6) and BMI > 25 (OR, 4.8; CI, 2.7-8.5) were significant variables predicting AHI > 30. Even after controlling for BMI, the effect of ALVC was still significant. The laryngeal position is lower in men than women. Aging is associated with a lower laryngeal position, and a longer ALVC is independently associated with OSA severity in Japanese patients. We conclude that both laryngeal descent and BMI may be risk factors for OSA.

Gross anatomical features of the tongue, lingual skeleton and laryngeal mound of Rhea americana (Palaeognathae, Aves): morpho-functional considerations

The tongue body of Rhea americana is triangular and partially pigmented with each caudo-lateral margin displaying a round, sub-divided lingual papilla. The tongue root is a smooth, non-pigmented tract of mucosa. The tongue body is supported by the paraglossum and distal half of the rostral projection of the basihyal (RPB), and the tongue root by the proximal half of the RPB, body of the basihyal and proximal ceratobranchials. An urohyal is absent; however, peculiar to R. americana, the caudal margin of the cricoid body displays a median projection, which may represent the remnant of the urohyal incorporated into the cricoid. The laryngeal mound is less elevated, the arytenoid cartilages are smaller than in other ratites, and the caudal margin displays pharyngeal papillae that vary in shape and number. The unique morphology of the lingual skeleton and its positioning within the tongue of R. americana, the rostral insertion of the M. ceratoglossus, the absence of the urohyal (enhanced ventroflexion) and the caudal positioning and mobile attachment of the ensheathed basihyal to the paraglossum would appear to allow independent movement of the tongue body relative to the hyobranchial apparatus. Additionally, the deeply indented base and rostral oval opening in the paraglossum limits the length of cartilage present in the midline of the tongue body. This may allow the tongue the necessary flexibility for the lingual papillae to clean the choana. The cleaning action of the tongue would occur simultaneously with the previously described role of this organ and associated structures during feeding. Thus, the so-called reduced, ancestral tongue of R. americana may be structurally and functionally more complex than previously believed.

Placement of the diaphragmatic vertebra in catarrhines: Implications for the evolution of dorsostability in hominoids and bipedalism in hominins

A fundamental adaptation to orthograde posture and locomotion amongst living hominoid primates is a numerically reduced lumbar column, which acts to stiffen the lower back and reduce injuries to the intervertebral discs. A related and functionally complementary strategy of spinal stability is a caudal position of the diaphragmatic vertebra relative to the primitive condition found in nonhominoid primates and most other mammals. The diaphragmatic vertebra marks the transition in vertebral articular facet (zygapophysis) orientation, which either resists (prediaphragmatic) or allows (postdiaphragmatic) trunk movement in the sagittal plane (i.e., flexion and extension). Unlike most mammals, which have dorsomobile spines (long lumbar columns and cranially placed diaphragmatic vertebrae) for running and leaping, hominoids possess dorsostable spines (short lumbar columns and caudally placed diaphragmatic vertebrae) adapted to orthogrady and antipronogrady. In contrast to humans and other extant hominoids, all known early hominin partial vertebral columns demonstrate cranial displacement of the diaphragmatic vertebra. To address this difference, variation in diaphragmatic placement is assessed in a large sample of catarrhine primates. I show that while hominoids are characterized by modal common placement of diaphragmatic and last rib-bearing vertebrae in general, interspecific differences in intraspecific patterns of variation exist. In particular, humans and chimpanzees show nearly identical patterns of diaphragmatic placement. A scenario of hominin evolution is proposed in which early hominins evolved cranial displacement from the ancestral hominid condition of common placement to achieve effective lumbar lordosis during the evolution of bipedal locomotion.

Abstract P176: Associations of Cardiovascular Disease Risk Factors with Aorto-Iliac Bifurcation Location

Objectives: We investigated associations of cardiovascular disease (CVD) risk factors and calcified atherosclerosis with the aortic bifurcation location. Background: In older persons, the aorto-iliac bifurcation is found in a more caudal position along the lumbar spine. Little is known about what other factors may play a role in the location of the bifurcation. Methods and Results: We evaluated community living individuals, free of clinical CVD, who had completed abdominal, computed tomography (CT) scans. The aorto-iliac bifurcation distance (AIBD), bifurcation to L5-S1 disc space, was determined from CT scans. The 1,711 participants (51% male) in this study had a mean age of 62 ± 10 years, and a mean AIBD of 26 ± 15mm. Age was a strong correlate of AIBD, such that on average, individuals > 80 years had bifurcations positioned 16mm lower than individuals < 50 years. In multivariable linear regression, standardized for lumbar spine height, older age, smoking, hypertension, and larger aortic diameter (ADD) were each independently associated with a smaller AIBD (more caudal location of the bifurcation). In contrast, diabetes and elevated triglycerides were independently associated with a larger AIBD (more cephalad location). Conclusions: A more caudal position of the aorto-iliac bifurcation is associated with some, but not all, CVD risk factors. Future studies should access the position of the bifurcation as a useful surrogate for vascular aging, or a prognosticator for CVD.

Stem Cell Therapy Ameliorates Bladder Dysfunction in an Animal Model of Parkinson Disease

Different cell based therapies have been tested, focusing on motor function. We evaluated the effect of human amniotic fluid stem cells and bone marrow derived mesenchymal stem cells (ALLCELLS, Emeryville, California) on bladder dysfunction in a rat model of Parkinson disease. A nigrostriatal lesion was induced by 6-hydroxydopamine in 96 athymic nude female rats divided into 3 treatment groups. After 2 weeks the groups were injected with human amniotic fluid stem cells, bone marrow derived mesenchymal stem cells and vehicle for sham treatment, respectively. At 3, 7, 14 and 28 days the bladder function of 8 rats per group was analyzed by conscious cystometry. Brains were extracted for immunostaining. The nigrostriatal lesion caused bladder dysfunction, which was consistent in sham treated animals throughout the study. Several cystometric parameters improved 14 days after human amniotic fluid stem cell or bone marrow derived mesenchymal stem cell injection, concomitant with the presence of human stem cells in the brain. At 14 days only a few cells were observed in a more caudal and lateral position. At 28 days the functional improvement subsided and human stem cells were no longer seen. Human stem cell injection improved the survival of dopaminergic neurons until 14 days. Human stem cells expressed superoxide dismutase-2 and seemed to modulate the expression of interleukin-6 and glial cell-derived neurotrophic factor by host cells. Cell therapy with human amniotic fluid stem cells and bone marrow derived mesenchymal stem cells temporarily ameliorated bladder dysfunction in a Parkinson disease model. In contrast to integration, cells may act on the injured environment via cell signaling.

Different surgical findings in congenital and acquired undescended testes

To compare surgical findings in congenital and acquired undescended testes (UDT). A review of 139 boys with 158 congenital UDT and 69 boys with 84 acquired UDT was performed. The most caudal testicular position preoperatively, testis position at surgery, patency of the processus vaginalis and epididymal anomalies were prospectively recorded. In the congenital group, orchiopexy had been performed at median age (range) 4.9 (1.5-14.6) years, while the median age (range) in the acquired group was 11.9 (3.8-23.3) years. Preoperatively, only congenital UDT were found not palpable or emergent inguinal, while only acquired UDT could be manipulated in an unstable scrotal position. In comparison with congenital UDT, acquired UDT were significantly more often located at the scrotal entrance, 27/158 vs 32/84 respectively (P < 0.001). At surgery anorchia, vanished testis or testes lying intra-abdominally were only registered in the congenital UDT group. Also 37/158 congenital UDT were located in the superficial inguinal pouch vs 52/84 of the acquired UDT (P = 0.04). In congenital UDT the processus vaginalis was wide open in 74/158, while in acquired UDT the processus vaginalis was closed in 46/84 (P < 0.001) and small open in 26/84 (P = 0.04). Epididymal anomalies were more often seen in the congenital UDT group (37%) than in the acquired group (11%). The most caudal position of congenital UDT after manipulation before surgery was at the scrotal entrance. These testes were frequently associated with epididymal anomalies and wide open processus vaginalis. This was in contrast to acquired UDT, which can often be pushed down well below the scrotal entrance and are more likely to be situated in the superficial inguinal pouch, with a normal epididymis and closed processus vaginalis.

Remarks on Doryphoribius flavus (Iharos, 1966), and description of three new species (Tardigrada, Hypsibiidae)

The author examined paratypes of Doryphoribius flavus (Iharos, 1966) (formerly Hypsibius (Isohypsibius) flavus Iharos, 1966), and the holotype and paratypes of D. citrinus (Maucci, 1972) (which is considered a junior synonym of D. flavus), furnishing new details, both qualitative and metric, to the description of the species, and providing a discussion on the synonymy. Specimens, previously attributed to these species, from Amazonia, South Africa, and Bali, were also examined and proved to belong to three species new to science: Doryphoribius amazzonicus sp. nov., Doryphoribius bindae sp. nov., and Doryphoribius solidunguis sp. nov. Doryphoribius amazzonicus sp. nov. has a reticular cuticular ornamentation with ridges forming a tubercle at each crossing; legs lacking cuticular ornamentation; buccal tube slightly longer than in D. flavus with respect to the body length, stylet supports inserted on the buccal tube in a slightly more caudal position; peribuccal papulae present; teeth and ridges appear to be absent in the buccal cavity; pharyngeal bulb with apophyses and two macroplacoids; claws slightly shorter and stouter than in D. flavus. Accessory points and smooth lunules present. No other cuticular thickening present on the legs. Doryphoribius bindae sp. nov. has a delicate reticular cuticular ornamentation formed by narrow ridges with a tiny tubercle at each crossing; a fine reticular design present on the legs; peribuccal papulae present, buccal armature with only one dorsal tooth near the medial margin of each stylet sheath. Pharyngeal bulb with apophyses and two macroplacoids. Accessory points and small lunules present. No other cuticular thickening present on the legs. Doryphoribius solidunguis sp. nov. has a very obvious reticular cuticular ornamentation with an irregular shape and size mesh (usually large) delimited by thick, sometimes protruding ridges that may form tubercles at crossings; cuticle of the legs smooth; peribuccal papulae present and two pairs of dorsal teeth lying along the anterior margins of the stylets sheaths. Pharyngeal bulb with apophyses and two macroplacoids. The claws are large and stout with very small accessory points; lunules present, those of the inner claws more evident than in similar species; a cuticular bar is present on the first three pairs of legs. Doryphoribius flavus was considered widespread, but this work exposing cryptic species indicates that the geographic distribution is more restricted.

Comparative Morphological Configuration of the Cardiac Nervous System in Lorises and Galagos (Infraorder Lorisiformes, Strepsirrhini, Primates) with Evolutionary Perspective

The detailed systematic morphology and comparative anatomy of the autonomic cardiac nervous system (ACNS) with its surrounding structures were examined in 14 sides of 7 Lorisiformes species (lorises and galagos) to consider its evolutionary differences and similarities to others in the primate lineage. Our detailed descriptions clarified that (1) a family-dependent morphology of the ACNS does not exist although several variations are recognized as common variation in Lorisiformes, (2) the morphology of the ACNS in Lorisiformes is almost consistent regardless of the number of presacral vertebrae and cardiac positions, and (3) the ACNS morphology in Lorisiformes is extremely different from that in New and Old World monkeys, gibbons, and human, specifically in a narrower contribution of the superior cervical ganglion to the spinal cervical nerves, the caudal position and organization of the cervicothoracic ganglion, and the narrower origins of the sympathetic cardiac nerves, although all parasympathetic vagal cardiac branches are consistently present among the primates. Based on these detailed findings, the systematic and evolutionary morphologies of the ACNS are discussed and compared with our previous works. These results suggest the primate ACNS preserves its evolutionary history without modification and specialization by its functional adaptation as seen in the somatic system.

Improved procedure for implanting radiotransmitters in the coelomic cavity of snakes

To investigate the expulsion of radiotransmitters in snakes and modify the surgical technique for coelomic implantation to prevent its occurrence. To enable monitoring of snakes for an ecological study, radiotransmitters were implanted in 23 south-west carpet pythons (Morelia spilota imbricata) using the standard surgical technique. In a further 23 pythons we used a refinement of the technique, which anchored the tracking device, using non-dissolvable sutures, to the snake's rib-cage. We also investigated the potential mechanisms for expelling the radiotransmitters in one snake that underwent an exploratory coeliotomy. Of the initial group of snakes, 12 (52%) expelled the radiotransmitter between 4 days and 3 years post implantation. In the later group, which underwent the refined technique of implantation, none of the radiotransmitters was expelled and no adverse responses were observed. An appropriately sized radiotransmitter anchored to the rib-cage of the snake will prevent expulsion of the device and appears to be well tolerated. Non-attachment of the tracking device enables it to migrate along the length of the body, particularly during feeding and reproduction. Caudal positioning of the transmitter's antenna provides a possible pathogenesis for expulsion into the cloaca.

PRE‐RIGOR MANIPULATION OF BEEF FORESHANK ALTERS SARCOMERE LENGTH OF INDIVIDUAL CHUCK MUSCLES

ABSTRACT Sixteen beef carcasses were harvested to determine the effect of pre‐rigor foreshank positioning on the ultimate sarcomere length and objective tenderness values of seven chuck muscles. After final inspection, the left side foreshank was positioned caudal to the point of the shoulder and secured until the completion of rigor. The right side foreshank served as the control and was allowed to hang in the normal position, cranial to the point of the shoulder. Biceps brachii, infraspinatus, pectoralis profundus, serratus ventralis, supraspinatus, teres major and triceps brachii muscles were excised from each carcass half for sarcomere length and Warner–Bratzler shear force determinations. Results indicate that sarcomere length was altered (P &lt; 0.05) for all muscles. When the foreshank was placed in the caudal position pre‐rigor, both the serratus ventralis and triceps brachii muscles had higher (P &lt; 0.05) shear values than when the foreshank was allowed to remain in its natural position.PRACTICAL APPLICATIONSAs the beef industry continues to search for methods to add value to the chuck, these data may offer insight into a practical method to increase sarcomere length and enhance palatability and marketability of underutilized muscles.

Preventing Alar Retraction by Preservation of the Lateral Crus

Resecting the cephalic component of the lateral crus in an attempt to reduce tip bulbosity has the potential to aggravate and/or cause alar retraction. It is a more serious problem for those patients who exhibit borderline alar retraction. Fourteen primary rhinoplasty patients with borderline alar/columellar relationships for alar retraction formed the study. They did not warrant frank treatment of alar retraction but did exhibit tip bulbosity. An "island" of cephalic lateral crus was developed by an intercartilaginous incision and another 6 mm cephalic to the caudal border of the lateral crus. One or more mattress sutures were placed in the main body of the lateral crus to stiffen and straighten it. The "island" of cephalic crus was then slipped under the main body of the lateral crus. At 11 months to 2(1/2) years, 13 of the 14 patients demonstrated no significant change in their preoperative alar/columellar relationships. Bulbosity was corrected in all patients. One patient, however, required a revision using an alar contour rim graft. The mean preoperative alar-nostril axis measurement was 1.48 mm (range, 1.3 to 1.9 mm) in contrast to a mean postoperative measurement of 1.71 mm (range, 1.5 to 2.2 mm). A one-tailed paired t test indicated no statistically significant difference between preoperative and postoperative values. The cephalic part of the lateral crus can act as a lateral crural strut to maintain the ala in a more caudal position. The technique is useful for borderline alar retraction and when lengthening the short nose for which there is a need to preserve side wall length.

Connections of the auditory brainstem in a songbird, Taeniopygia guttata. II. Projections of nucleus angularis and nucleus laminaris to the superior olive and lateral lemniscal nuclei

Three nuclei of the lateral lemniscus are present in the zebra finch, ventral (LLV), intermediate (LLI), and dorsal (LLD). LLV is separate from the superior olive (OS): it lies closer to the spinal lemniscus and extends much further rostrally around the pontine periphery. LLI extends from a caudal position ventrolateral to the principal sensory trigeminal nucleus (LLIc) to a rostral position medial to the ventrolateral parabrachial nucleus (LLIr). LLD consists of posterior (LLDp) and anterior (LLDa) parts, which are largely coextensive rostrocaudally, although LLDa lies medial to LLDp. All nuclei are identifiable on the basis of cytochrome oxidase activity. The cochlear nucleus angularis (NA) and the third-order nucleus laminaris (NL) project on OS predominantly ipsilaterally, on LLV and LLI predominantly contralaterally, and on LLD contralaterally only. The NA projections are heavier than those of NL and differ from them primarily in their terminations within LLD: NA projects to LLDp, whereas NL projects to LLDa. In this the projections are similar to those in the barn owl (Takahashi and Konishi [1988] J Comp Neurol 274:212-238), in which time and intensity pathways remain separate as far as the central nucleus of the inferior colliculus (MLd). In contrast, in the zebra finch, although NA and NL projections remain separate within LLD, the projections of LLDa and LLDp become intermixed within MLd (Wild et al., J Comp Neurol, this issue), consistent with the intermixing of the direct NA and NL projections to MLd (Krützfeldt et al., J Comp Neurol, this issue).

Absence of the Septum Pellucidum Associated with a Midline Fornical Nodule and Ventriculomegaly: A Report of Two Cases

We report two autopsy cases that revealed the partial absence of the septum pellucidum with ventriculomegaly. In each case, the brain showed mild dilatation of both frontal horns of the lateral ventricles, normal third and fourth ventricles and no aqueductal stenosis. The posterior portion of the septum pellucidum was absent and the fornices were fused in a single midline nodule, abnormally displaced to a caudal position and lodged in the foramina of Monro. The brain base showed no apparent abnormalities; the optic nerves were well developed. We conclude that the caudally displaced fornix in the absence of the septum pellucidum may have intermittently obstructed the foramina of Monro and induced mild ventriculomegaly.

3D-FEM and histomorphology of mandibular reconstruction with the titanium functionally dynamic bridging plate

Biomechanical investigation of the mandible is difficult due to the complex geometrical structure. A three-dimensional finite element model of the mandible and masticatory muscles was produced with approximately 23,000 hexahedral elements. On this model, mesial and distal portions of the jaw were resected and bridged with a buccal and/or caudally positioned bridging plate. The plate was fixed caudal or buccal to the mandible. The defect was left as it was or reconstructed with an exactly fitting transplant defined as bone. The jaw was loaded at a predefined point. The changes in stresses and deformations of bone, the transplant and the bridging plate were analysed. In the caudally positioned bridging plate, finite element analysis showed lesser stresses around the fixation screws of the bridging plate. During reconstruction of the lateral defect, the buccal (ramus)-caudal (corpus) position of the bridging plate showed fewer stresses and deformations than purely buccal positioning. The caudal position of the bridging plate has biomechanical advantages and facilitates fixation of the plate, and fixation of a bone graft on the jaw stumps. Histomorphological investigations, 12 weeks and 7 years after reconstruction, show partial osseous integration or transformation of autologous iliac crest transplants.

Finite element analysis of four different implants inserted in different positions to stabilize an idealized trochanteric femoral fracture

Biomechanical analysis of the ideal placement of new intramedullary implants for stabilization of trochanteric fractures is not currently available. The aim of the presented study is to determine to what extent four intermedullary nails (Gliding-Nail, Gamma-Nail, PFN-A and Targon-PF), inserted in different positions, differ mechanically. A proximal femur was reconstructed on the basis of clinical CT data as a surface model. Load application equivalent to the one-leg stance phase during gait was assumed, taking into account a limited number of active muscle forces. The four implants were inserted cranially and caudally into the bone structure and a model of a trochanteric fracture was created. Criteria with point ratings were introduced to quantify a favourable fracture healing situation. Finite element simulation showed clear differences between the different implants with regard to the distributions of stress and strain at the two fracture surfaces in the model and the von Mises stress in the implant itself. It was apparent for three implants under investigation that the caudal position generated better fracture healing conditions than the cranial position. Only the Targon PF demonstrated better fracture healing conditions in the cranial position. Evaluation based on the point rating system revealed that the caudal position was the ideal position for the PFN-A, Gamma-Nail and Gliding-Nail. The Targon-PF demonstrated some advantages over the other implants in the caudal position.

Tracheostomy in the Giant Anteater (Myrmecophaga tridactyla)

Anesthesia in the giant anteater (Myrmecophaga tridactyla) may be complicated by apnea. Although emergent orotracheal intubation may be possible in other species, the particular anatomy of the anteater prevents a smooth intubation. A technique, developed on a cadaver model, is described for a surgical approach to the trachea of the giant anteater that may be used to secure an airway in an anesthetized animal under emergent conditions. The approach is complicated by the presence of the large paired submaxillary salivary gland and the relatively deep and caudal position of the larynx relative to the ramus of the mandible. This procedure, however, appears to be a feasible method to achieve endotracheal intubation in the anteater.

Conservation genomics of Atlantic salmon: SNPs associated with QTLs for adaptive traits in parr from four trans-Atlantic backcrosses

European Atlantic salmon (Salmo salar) differ in skin pigmentation and shape from the North American lineage of Atlantic salmon but the genetic basis of these differences are poorly understood. We created four large (N=300) backcross families by crossing F1 hybrid male siblings to two females from the European and two from the North American aquacultural strains. We recorded 15 morphological landmarks and two skin pigmentation, three growth and three condition traits on parr. The backcross families were genotyped for at least 129 SNPs (single nucleotide polymorphisms) within expressed sequence tags (ESTs) spaced throughout the Atlantic salmon linkage map. The high polymorphism and low rates of crossover in our hybrid sires provided enough statistical power to detect 79 significant associations between SNP markers and quantitative traits after experiment-wide permutation analysis for all families within traits. Linkage group AS22 contained a quantitative trait loci (QTL) for parr mark number; its homolog AS24 contained a large QTL, which explained 26% of the phenotypic variance in parr mark contrast. We found 25 highly significant QTLs for body shape and fin position on seven different linkage groups, and 16 for growth and condition on six different linkage groups. QTL(s) for pectoral fin position, caudal peduncle position, late parr growth and condition index were associated with an SNP on linkage group AS1, which was linked to the sex-determining locus. Our work adds to the evidence that much of the variation in growth rate, shape and skin pigmentation observed among Atlantic salmon parr from different natal streams is genetic.