Presence Of Lamina Research Articles

Hemipenial morphology of whiptail lizards Glaucomastix abaetensis and Glaucomastix littoralis , with comments on the genus Ameivula (Teiidae: Teiinae).

Hemipenes are important structures for the systematics of Squamata, and may assist in the diagnosis of closely related taxa. Only one of the species of Glaucomastix (G. venetacauda) had its hemipenial morphology described in literature so far. Here we analyze and describe for the first time the hemipenes of seven specimens of G. abaetensis and 20 specimens of G. littoralis from the reptile collection of Museu Nacional, Universidade Federal do Rio de Janeiro. In both species the hemipenes are bilobed with a forked sulcus spermaticus in a centripetal orientation and present laminar ornamentations on the hemipenial body and paired awns on the apical region of the lobes. The two species differed from each other only in the modal number of proximal laminae. The main differences in hemipenial morphology between Glaucomastix and its sister genus Ameivula are the presence of laminae in the hemipenial body (absent in Ameivula) and the absence of digitiform papillae on the apical lobular region (present in Ameivula). We expect that our data can be used as an additional tool to diagnose species within the genus Glaucomastix/Ameivula.

Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture

ObjectiveThough magnetic resonance imaging (MRI) is the primary modality of investigation for determining the extent of PLC injuries in lower lumbar fractures (L3-L5), the reliability of computed tomography (CT) has not been well defined. The main objective of this study is to analyze the diagnostic accuracy of combined CT findings for detecting posterior ligamentous complex injury in patients with lower lumbar fractures. MethodsWe retrospectively analyzed data from 108 patients who presented with traumatic lower lumbar fractures. CT parameters like loss of vertebral body height, local kyphosis, retropulsion of fracture fragment, interlaminar distance (ILD), interspinous distance (ISD), supraspinous distance (SSD), interpedicular distance (IPD), canal compromise, facet joint diastasis in axial images (FJDA) and sagittal images (FJDS), presence of lamina and spinous process fracture were calculated using axial and sagittal CT images. The presence or absence of PLC injury was determined using MRI as a reference standard. ResultsAmong 108 patients PLC injury was identified in 57 (52.8%). On univariate analysis local kyphosis, retropulsion of fracture fragment, ILD, IPD, FJDS, FJDA, and the presence of spinous process fracture were found to be significant (P < 0.05) in predicting PLC injury. Whereas on multivariate logistic regression analysis, FJDS (P= 0.039), and FJDA (P= 0.003) were found to be variables independently associated with PLC injury. ConclusionAmong the various CT parameters, facet joint diastasis (FJDS > 4.2 mm and FJDA > 3.5 mm) is the most reliable factor in determining PLC injury.

Deformation Analysis of the Rock Surrounding a Tunnel Excavated through a Gently Dipping Bed

To investigate the deformation and stability of the rock surrounding a tunnel excavated through layered rock, a three-dimensional numerical simulation was conducted to compare and analyze the right line of the YD2K100+560–630 two-stage docking cross-section of the Yuelongmen Tunnel using a ubiquitous joint model. Based on 3-D numerical simulations, the following conclusions were drawn: (1) The excavation on the construction entrance side significantly disturbed the construction exit side, and the exit side was more disturbed in the steeply dipping layer than in the gently dipping layer. (2) The influence of the dip angle of the laminae on the uplift of the tunnel invert was greater than the influence on the tunnel vault settlement when the laminae were oriented perpendicular to the trend of the tunnel and two-stage docking excavation was used. (3) When two-stage excavation was applied to gently inclined laminated rock, there was an obvious disturbance to both the top of the tunnel (less than one time the diameter of the through face; and to the bottom of the tunnel within 0.5 time the diameter of the through face on the side with the stopping construction exit side during the tunnelling process. When tunnel excavation was conducted against the trend of the layer, there was obvious disturbance to the top of the tunnel within 0.5 time the diameter of the through face and to the bottom of the tunnel within one time the diameter of the entrance face) on the construction exit side during the tunnelling process due to the presence of laminae. The excavation on the construction entrance side significantly disturbed the construction exit side. When docking and penetrating layered rock tunnels, priority should be given to docking and penetrating in the direction corresponding to the layers, and temporary support on the exit side should be strengthened to ensure the deformation stability of the surrounding rock mass.

Osteochondral lesion depth on MRI can help predict the need for a sandwich procedure

PurposeAutologous subchondral bone grafting in combination with autologous chondrocyte implantation (ACI) (sandwich procedure) is a well-accepted procedure for the treatment of osteochondral lesions of the knee. This requires a different surgical technique and preoperative planning compared to ACI alone. In addition, pain from bone marrow donor site locations can be expected and should be part of patient consent and expectations. This study evaluates whether the MRI made as part of the standard preoperative cartilage patient work up has the diagnostic accuracy to predict the need for a sandwich procedure. Methods and materialsRetrospectively, 185 preoperative MRI scans (PD and T2 sequences) of patients planned for ACI were included. The integrity of the subchondral bone and lamina was scored by four different observers (3 radiologists, and 1 orthopaedic resident). The depth of the defect was measured perpendicular from articulating surface to the bottom of the bony lesion. The area under the curve (AUC) for subchondral defect on MRI (i.e. lamina or bone defect or expert impression), depth measurements and eventual sandwich procedure were calculated. Also inter-observer Kappa values were determined. ResultsThe AUCs for lamina (0.74–0.80) and bone defect (0.73–0.79) were fair and inter-observer Kappas ranged from 0.49 to 0.76, indicating a moderate-good inter-observer agreement and moderate prediction of the need for a sandwich procedure based on the presence of lamina and or subchondral bone defect on MRI. However, depth measurements resulted in an AUC of 0.90 (95% CI: 0.84–0.95,) with an optimal cut-off point at 6.5mm depth of the lesion (90% sensitivity, 80% specificity) to predict the need for a sandwich procedure. ConclusionOurs is the first study examining MRI as a diagnostic tool in predicting the need for a sandwich procedure. Our results show that the integrity of the subchondral layer on MRI has a moderate role in predicting the need for an eventual autologous bone graft to augment ACI whereas in our cohort a depth of the lesion above 6.5mm accurately predicts the need for a sandwich procedure. This can aid in optimising the preoperative planning and patient consent.

Carrageenan Induced Phosphorylation of Akt is Dependent on Neurokinin-1 Expressing Neurons in the Superficial Dorsal Horn

BackgroundPaw carrageenan induces activation of phosphatidylinositol 3-kinase (PI-3K) and Akt in dorsal horn neurons in addition to induction of pain behavior. Spinal PI-3K activation is also thought to be required for inflammation-induced trafficking of GluA1, AMPA receptor subunits, into plasma membranes from cytosol. Phosphorylation of Akt has a unique time course. It occurs first in the superficial dorsal horn (0.75 h), then soon dissipates and is followed an hour later by Akt phosphorylation in deeper dorsal horn laminae, primarily lamina V. Initially, we wished to determine if Akt phosphorylation in the deeper laminae were dependent on the presence of lamina I, neurokinin receptor bearing projection neurons. As the study progressed, our aims grew to include the question, whether carrageenan-induced GluA1 subunit trafficking was downstream of Akt phosphorylation.ResultsRats pretreated with spinal saporin conjugated to a stabilized form of substance P had substantial loss of neurons with neurokinin 1 receptors throughout their superficial, but not deep dorsal horns. Animals pre-treated with substance P-saporin exhibited no change in locomotor ability and a small, but significant decrease in carrageenan-induced mechanical allodynia when compared to animals pre-treated with spinal saporin alone. Importantly, carrageenan-induced phosphorylation of Akt was blocked, in the substance P-saporin treated group, throughout the spinal cord grey matter. In marked contrast, carrageenan induced-trafficking of the GluA1 receptor subunit increased equivalently in both treatment groups.ConclusionsWe infer from these data that 1) phosphorylation of Akt in the deep dorsal horn is dependent on prior activation of NK1 receptor bearing cells in superficial dorsal horn, and 2) there are parallel spinal intracellular cascades initiated by the carrageenan injection downstream of PI-3K activation, including one containing Akt and another involving GluA1 trafficking into neuronal plasma membranes that separately lead to enhanced pain behavior. These results imply that the two pathways downstream of PI-3K can be activated separately and therefore should be able to be inhibited independently.

Influence of petiole and lamina on adventitious shoot initiation from leaf explants of Paulownia fortunei.

Adventitious shoot bud differentiation occurred preferentially from the petiolar cut ends of leaf explants of Paulownia fortunei cultured on Murashige and Skoog medium supplemented with 4 μMα-naphthaleneacetic acid and 20 μM benzyladenine. The details of plantlet regeneration and successful transplantation to soil have been reported earlier. We now show that besides medium supplementation with auxin and cytokinin, the presence of lamina and petiole in the explant influence shoot bud induction. Explants with the basal half of the lamina and the entire petiole were much more responsive than those with whole lamina and petiole. A dual-culture-medium technique which permitted incubation of the two ends of excised petioles under two different phytohormone regimes was devised. Our data suggest that some of the diffusible factors from the lamina may be phytohormones, and that the establishment of an endogenous phytohormone gradient in the explants may affect shoot bud differentiation in this culture system.

Origin of Carbonate Pseudopellets

Several lines of evidence are presented including lack of fossils and bioturbation, highly irregular contacts between lamina and micrite, identical textures of aggregates and micrite, presence of lamina and association of aggregates with sorted ferrugenous grains, and hydraulic equivalence of pellets and detritals. These suggest that certain micro-sized, ellipsoidal to spherical, rounded aggregates of micrite, here termed pseudopellets, are formed by hydraulic forces.