Incomplete Ring Research Articles

Preliminary Study on HFSE Mineralization in the Peralkaline Granites of Nusab El Balgum Area, South Western Desert, Egypt

Nusab El Balgum mass complex represents one of peralkaline volcanic activity phenomena in the south Western Desert of Egypt, which is typical for within-plate event, which formed in Mesozoic period. It consists of acidic volcanic (rhyolite and their pyroclastics) and sub-volcanic granitic rocks (incomplete ring, small stock and dyke of a peralkaline aphanites) as well as dykes (trachyte, bostonite, rhyodacite, rhyolite and porphyritic rhyolite) variable in thickness and the most of run in NNE-SSW trend. The peralkaline granitic rocks, especially those located at the southwestern part of this mass are characterized by extreme enrichments in HFSE (rare metals such as Zr, Nb, U and Th and REEs) which are the highest concentrations (e.g., >1% Zr, 0.5% Nb and 2.6% total REEs, Y up to 1%, eU up to 300 ppm and eTh up to 1100 ppm). The rare metal bearing minerals are thorite, uranothorite, autunite, amorphous secondary uranium, zircon and ferrocolumbite, while the REEs bearing minerals are bastnaesite, monazite and xenotime. The positive relations in all of the binary diagrams of Zr versus Nb, Y, eU and eTh, Nb versus Y, eU and eTh, Y versus eU and eTh in post magmatic intensely hematised peralkaline granites indicated that, this process is responsible for the enrichment in these HFSE. The chondrite-normalized pattern of high-altered peralkaline granites indicates: 1) higher LREEs enriched pattern (La/Gd = 11.34 and 12.25) means the alteration processes taking place under open system and these rocks evolved from magma of lithospheric rifting, 2) ΔCe 2O, and thus very low viscosity, despite its low temperature (ments, as indicated by strong negative Eu anomalies; and c) it had abundances of HFSE cations. Redistribution of elements took place by post magmatic hydrothermal solutions.

Letter to the Editor Rare cardiovascular anomaly: congenital unilateral absence of the pulmonary artery

Letter to the Editor Rare cardiovascular anomaly: congenital unilateral absence of the pulmonary artery

Mass lesions in the brain: tumor or multiple sclerosis? Clinical and imaging characteristics and course from a single reference center.

In demyelinating disease spectrum, tumor-like (tumefactive) demyelinating lesions (TDL) are rarely seen. Atypical imaging and clinical features of these lesions may cause misdiagnosis of tumor or abscess. 25 patients with TDL in our center were followed and clinical, magnetic resonance imaging (MRI), magnetic resonance spectroscopy, cerebrospinal fluid (CSF) findings and disease course were retrospectively evaluated. Mean age at symptom onset was 29 years. Motor and sensory deficits were most common symptoms and 18 of them were polysymptomatic. Mostly frontal and parietal regions were affected. 10/25 patients were initially misdiagnosed clinically as brain abscess, primary central nervous system tumor metastasis. T2-hypointense rim, incomplete ring enhancement of the lesions on post-gadolinium T1- weighted imaging on brain MRI enabled accurate diagnosis of TDLs. 13 of 21 patients with first-TDL presentation sustained a monophasic course, remaining 8 patients converted to multiple sclerosis (MS) at a mean 38.4 months follow-up. Clinical isolated syndrome (CIS) patients were older than patients who developed MS and Expanded Disability Status Scale was lower (0.96 vs 3.7). Although MRI, CSF and pathologic examination help in differential diagnosis of the mass lesions, close follow-up is still crucial for the definite diagnosis. A higher MS conversion rate was found in patients with a younger TDL onset age.

頭部超音波検査で2つの結節パターンを認めた結節性硬化症の新生児例

We report a neonatal case of tuberous sclerosis (TS) presenting two types of tubers on cranial ultrasound (US) images. Multiple cardiac rhabdomyomas (CRs) were detected at 36 weeks’ gestation by intrauterine US. Postnatally, the patient had no heart problems. On her second day after birth, she experienced generalized tonic clonic seizures. On the same day, tubers, white matter lesions, and subependymal nodules were recognized on her brain magnetic resonance imaging (MRI) scan. In addition, cranial US showed multiple brain lesions. The patient fulfilled the diagnostic criteria for TS. Two types of tubers were detected on US: an incomplete ring resembling a half-eaten doughnut and a solid mass. These could be observed more clearly with a 12-MHz linear probe than with a 7-MHz sector probe. If the fetal US examination had been performed with suitable probes, her brain lesions could have been prenatally detected. When CRs can be detected on fetal US, neuroimaging enables a rapid diagnosis of TS. In addition to genetic testing and the morphology of tubers as seen on MRI, it is likely that the types of tubers seen on US facilitate forecasting of the postnatal severity of the neuronal manifestations of TS.

Structural and Metabolic Features of Two Different Variants of Multiple Sclerosis: A PET/MRI Study

Multimodality imaging such as proton magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) have provided information specific to the underlying mechanisms of many brain diseases, including multiple sclerosis (MS). To determine the structural and metabolic characterization of two particular variants of MS, namely tumefactive MS and Balo's concentric sclerosis (BCS). Conventional MR imaging, diffusion and perfusion MR, MR spectroscopy and PET imaging with F-18 fluorodeoxyglucose (FDG) and F-18 fluoromethylcholine (FCho) were performed. In a case with pathologically proven tumefactive MS, magnetic resonance imaging (MRI) showed a pseudotumoral lesion with incomplete ring enhancement, peripheral diffusion restriction, and high choline and lactate peaks on MRS. On follow-up, the lesion showed significant growth. In a case of BCS, MRI showed an onion-like lesion without contrast enhancement or diffusion restriction, and only a moderate increase in choline on MRS. The lesion remained stable on follow-up. On PET, there was no uptake of F-18 FDG in either type of MS lesion. Conversely, uptake of F-18 FCho was moderate in tumefactive MS, whereas no F-18 FCho uptake was noted in the lesion with, on MRI, typical features of BCS. Our findings illustrate that metabolic features may differ between variants of MS possibly signifying different disease activity.

Axial stiffness and ring deformation of complete and incomplete single ring circular external skeletal fixator constructs

To compare the axial stiffness, maximum axial displacement, and ring deformation during axial loading of single complete and incomplete circular (ring) external skeletal fixator constructs. 32 groups of single ring constructs (5 constructs/group). Single ring constructs assembled with 2 divergent 1.6-mm-diameter Kirschner wires were used to stabilize a 60-mm-long segment of 16-mm-diameter acetyl resin rod. Construct variables included ring type (complete or incomplete), ring diameter (50, 66, 84, or 118 mm), and fixation wire tension (0, 30, 60, or 90 kg). Axial loading was performed with a materials testing system. Construct secant stiffness and maximum displacement were calculated from the load-displacement curves generated for each construct. Ring deformation was calculated by comparing ring diameter during and after construct loading to ring diameter prior to testing. Complete ring constructs had greater axial stiffness than did the 66-, 84-, and 118-mm-diameter incomplete ring constructs. As fixation wire tension increased, construct stiffness increased in the 66-, 84-, and 118-mm-diameter incomplete ring constructs. Maximum axial displacement decreased with increasing fixation wire tension, and complete ring constructs allowed less displacement than did incomplete ring constructs. Incomplete rings were deformed by wire tensioning and construct loading. Mechanical performance of the 66-, 84-, and 118-mm-diameter incomplete ring constructs improved when wire tension was applied, but these constructs were not as stiff as and allowed greater displacement than did complete ring constructs of comparable diameter. For clinical practice, tensioning the wires placed on 84- and 118-mm-diameter incomplete rings to 60 kg is recommended.

Pulmonary Artery Sling and Tracheal Bronchus Presenting in a 2-Year-Old Child

Pulmonary artery sling is an incomplete vascular ring, the result of the left pulmonary artery arising from the right pulmonary artery and effectively constricting the airway, and it usually presents within the first weeks to months of life. We report a surgical correction of tracheal stenosis for a two-year-old patient associated with pulmonary artery sling and tracheal broncus.

Comparative morphology of serotonergic‐like immunoreactive elements in the central nervous system of kinorhynchs (kinorhyncha, cyclorhagida)

Cycloneuralian taxa exhibit similar organ system architectures, providing informative characters of metazoan evolution, yet very few modern comparative descriptions of cellular and molecular homologies within and among those taxa are available. We immunolabeled and characterized elements of the serotonergic nervous system in the kinorhynchs Echinoderes spinifurca, Antygomonas paulae, and Zelinkaderes brightae using confocal laser scanning microscopy. Fluorescent markers targeting DNA were combined with observations of auto-fluorescent structures to guide interpretations of the internal and external anatomy in each species. Results show a common pattern of the central nervous system with a circumenteric brain divided into ring-shaped anterior and posterior neuronal somata and a central neuropil connected to a multi-stringed, longitudinal ventral nerve cord. Structural similarities and differences in the nervous systems of these species were observed and described, stressing the incomplete ring nature of the anterior region of the kinorhynch brain, the functional relationship between the brain and the movable introvert, and the number and arrangement of nerve strings and somata of the ventral nerve cord. The ventral cord ends in two ventrolateral cell bodies in E. spinifurca, and forms a terminal loop associated with a midterminal spine in A. paulae and Z. brightae. The possible functional and phylogenetic significance of these features and arrangements are discussed.

A Biomechanical Comparison of Three Hybrid Linear‐Circular External Fixator Constructs

To evaluate the stiffness, displacement, ring deformation and bone model motion of 3 configuations of linear-circular hybrid fixator constructs loaded in axial compression, craniocaudal and mediolateral bending, and torsion. Biomechanical evaluation. Three hybrid construct configurations with 8 replicates/configuration. Construct Ia used a single, 84 mm, incomplete ring and 2 tensioned olive wires to stabilize 1 bone segment and a primary hybrid rod with 3 fixation pins to stabilize the other bone segment. Constructs Ia(d) and Ib were similar to Ia with the addition of a secondary diagonal hybrid rod. Construct Ib had a fixation pin inserted orthogonally from the diagonal rod. Constructs were loaded for 10 cycles in each mode of loading using a materials testing machine. Ring deformation was assessed by obtaining serial ring measurements. Bone model motion at the fracture gap as a result of loading was also calculated. Axial compression: constructs Ia(d) and Ib were significantly stiffer than construct Ia. Craniocaudal bending: Construct Ib was significantly stiffer than construct Ia. Mediolateral bending: there were no significant differences between constructs. Torsion: Construct Ib was significantly stiffer than constructs Ia and Ia(d) . Permanent ring deformation did not occur. Bone model translational motion decreased in constructs Ia(d) and Ib compared to construct Ia. Addition of a secondary hybrid rod as well as biplanar fixation pin placement improved construct stiffness in several loading modes.

Percutaneous edge-to-edge mitral valve repair for recurrent mitral regurgitation after percutaneous mitral annuloplasty: towards a staged approach

Sirs: Although mitral valve (MV) repair remains the treatment of choice to treat severe mitral valve regurgitation (MR), there is still a plethora of patients that, in light of their complex comorbid profile, could be approached in a less invasive fashion [1]. Timely echocardiography evaluation of the valve anatomy and the regurgitation flow-dynamics are crucial to plan an adequate percutaneous repair strategy [2, 3]. In this context, the MR often results from an annular dilatation that leads to a decreased MV leaflets coaptation. The percutaneous transvenous MitraClip -System (MitraClip, Abbot, USA) has been recently introduced and popularized to mimic the ‘‘edge to edge’’ MV repair firstly described by Alfieri et al. The results of the EVEREST II trial have demonstrated that the procedure is safe and associated with improvements in clinical outcomes [4]. Implantation of a percutaneous transvenous mitral annuloplasty (PTMA) device to reduce the MV annular size has also been shown to be feasible and safe [5–7]. After percutaneous annuloplasty with the MONARC device (Edwards Lifesciences, Irvine, California), a 12-months reduction in MR by C1 grade was observed in 85 % of patients with baseline MR grade C3 [6]. We report on a 74-year-old multi-morbid female patient (EuroScore 24, STS 14) presenting with severe MR recurring 2 years after implantation of a MONARC device. The patient was admitted in our institution with increasing shortness of breath and signs of heart failure (New York Heart Association (NYHA) class III). Echocardiography revealed a reduced left ventricular ejection fraction (LVEF 43 %) secondary to ischaemic cardiomyopathy. A markedly eccentric MR grade 3 (type IIIb Capentier’s functional classification) was also reported. The MV annulus was measured 3.9 cm (lateral–medial) and 3.6 cm (anterior–posterior) with a MV orifice area (MVOA) of 6.9 cm. An interventional strategy to address the MR was planned after exacerbation of the heart failure picture in spite of maximal medical treatment. Percutaneous placement of the MitraClip to maximize MV leaflets cooptation and reduce MR was performed under general anaesthesia and with continuous twoand three-dimensional echocardiography and fluoroscopy imaging. After standard implantation of the first clip within the main jet area, the severity of MR was reduced to grade 1? to 2. A second clip was implanted parallel to the first one to eliminate the residual regurgitation. At the end of the procedure there was no mitral stenosis (mean gradient of 3 mm Hg, MVOA of 2.5 cm) and only a trivial MR. Notice that there was a significant reduction of the MV anterior–posterior annular dimension (2.3 cm postinterventional) and no changes in the latero-medial size (unchanged at 3.8 cm) (Fig. 1). The patient was discharged home on the 8th postoperative day in NYHA class I–II. A 6-month follow-up confirmed the clinical and echocardiographic improvement. To the best of our knowledge MitraClip therapy to treat recurrent MR after previous PTMA has never been described before. In fact, PTMA with an incomplete ring decreases the septal-lateral annular diameter [6]. MitraClip implantation can facilitate MV leaflets coaptation and indirectly decrease the anterior–posterior MV annulus L. Paranskaya G. D0Ancona C. A. Nienaber H. Ince (&) Department of Cardiology, Heart Center Rostock, University Hospital of Rostock, E-Heydemann-Str. 6, 18057 Rostock, Germany e-mail: hueseyin.ince@med.uni-rostock.de

Screws, Facets, and Atlantoaxial Instability

The aim of this study was to calculate the prevalence of ponticulus posticus (a small bony bridge on the dorsal aspect of the atlas on lateral digital cephalometric radiographs) and classify it into a complete ring or an incomplete ring. The study also investigated its association with the presence or absence of cervicogenic headache in the examined population; a literature review of ponticulus posticus is also presented.The presence and types of ponticuli posticus were investigated on 500 digital lateral cephalograms and the same patients were questioned for a history of cervicogenic headache.In 500 patients, 79 ponticulus posticus (34 complete and 45 incomplete) were identified on the lateral cephalograms; therefore, the prevalence was 15.8%. The distribution of the type of ponticulus posticus was 13.1% in males and 17.9% in females in the studied sample. The overall prevalence of cervicogenic headache was 6% in the studied sample with a significant association between cervicogenic headache and type of ponticulus posticus.The study shows that ponticulus posticus is not a rare finding and its association with unexplainable headache, neck pain, and other symptoms as well as its importance and implications during management of cervical spine surgical procedures, especially those requiring lateral mass screw placements in the atlas, imply that radiologists and dentists in general should closely inspect the vertebral region on a lateral cephalogram.

INSARA: a new method for the analysis and visualization of Structure-Activity-Relationships

Due to the rapid progress in combinatorial chemistry and (high-throughput-) screening, the organization and mining of the large amount of produced data becomes an increasingly important task in the modern drug discovery process. Herein, one particular challenge is the recognition of SAR-patterns e.g. for the selection of promising compounds for further analysis or lead optimization. To support the medicinal chemist in doing this job a readily interpretable concept is required. Most published approaches addressing this problem (e.g. SARANEA [1]) use fingerprint similarity for the analysis of molecular relationships. Yet, a promising alternative and more intuitive way of comparing similarity is the maximum common substructure (MCS), the largest substructure in common between two molecules. Since computing the MCS is very demanding, it is usually not applicable to large data sets. To circumvent this and other drawbacks (e.g. the exact match or incomplete ring problems) our own in-house strategy INSARA (intuitive networks for Structure-Activity-Relationships analysis) employs reduced graphs (RG) instead of the original molecules in order to reduce the complexity of the problem to a manageable size. The advantage of RG is that only pharmacophoric features and functional units represented by a few pseudoatoms have to be compared [2]. Iterative super- and substructure searches and MCS calculations subsequently lead in an unsupervised manner to SAR networks. When associated with bioactivity data the networks can be used for SAR analysis. While focussing on pharmacophoric properties a more general overview about the similarities within the active set is expected. For initial performance evaluation two targets with well-known SARs (ACE and COX 2) were chosen.

The macrosemiiform fish companion of the Late Jurassic theropod Juravenator from Schamhaupten, Bavaria, Germany

A new neopterygian fish, Voelklichthys comitatus n. gen. n. sp., is described. The fish was found during the preparation of the theropod Juravenator starki Göhlich & Chiappe, 2006 in the same rock. The fish possesses numerous autapomorphies. The combination of autapomorphies is unique among Jurassic fishes and makes its taxonomic assignment difficult. The following characters are few examples demonstrating some of the peculiarities of the fish: The fish is small, oblong-shaped and has a large triangular head that is deeper than long; deepest point is at the level of the postparietal bone [parietal of traditional terminology] and the ventral end of the cleithrum. The skull roof is almost vertically oriented, with a strongly ossified and developed antero-dorsal orbital margin. Premaxilla and dentary possess very small conical teeth. The opercular apparatus is markedly narrow and deep. A clavicle is present. Both dorsal and ventral postcleithra are almost as deep as the maximum depth of the head; the dorsal postcleithrum is two times deeper than the ventral one. The vertebral centra are of arcocentral-type formed mainly by the development of the dorsal arcocentra. Pectoral and pelvic fins possess long rays that extend onto the pelvic and anal fins, respectively, whereas the rays of the dorsal and anal fins extend onto the caudal fin. The fish is interpreted as a macrosemiiform because it presents two of the three synapomorphies of the group (e.g., an incomplete circumorbital ring because the lateral edge of parietal bone [frontal of traditional terminology] makes up part of orbital margin and absence of a supramaxillary bone). The third macrosemiiform synapomorphy cannot be determined in the new fish because the coronoid bones and their dentition are not observed due to condition of preservation. The new fish shares a few characters with members of the families Macrosemiidae and the Uarbryichthyidae but lacks others so that presently, we place it in a family indeterminate within Macrosemiiformes. doi:10.1002/mmng.201200001

CADASIL mutation and Balo concentric sclerosis: A link between demyelination and ischemia?

A 26-year-old man of Portuguese descent with no significant past medical history presents with subacute onset of right-sided hemiparesis and aphasia, with marked expressive aphasia, word-finding difficulty, and rare paraphrasic errors. Examination demonstrated right central facial weakness, 2–3/5 strength in the right arm and leg, and dysmetria in the right upper and lower extremities. Reflexes were hyperactive on the right with a right-sided Babinski response. MRI of the brain showed multiple bilateral concentric ring-like structures in the centrum semiovale and the corona radiata on T2 imaging (figure,A), consistent with the pattern of Balo concentric sclerosis. There was associated restricted diffusion in 3 lesions and incomplete ring enhancement in 1 lesion. CSF analysis showed 30 leukocytes (79% lymphocytes, 4% monocytes), erythrocyte count was 850, and oligoclonal bands were absent. He was treated with 1 g of IV methylprednisolone daily for 5 days, with little improvement. He then underwent 5 plasmapheresis exchanges, with significant improvement of motor, sensory, speech deficits, and gait. Forty-five days after discharge, his examination showed 4+/5 strength in the right intrinsic muscles of the hand and a right-sided positional tremor. Gait and tandem gait were normal. He was placed …

The macrosemiiform fish companion of the Late Jurassic theropod <i>Juravenator</i> from Schamhaupten, Bavaria, Germany

A new neopterygian fish, <i>Voelklichthys comitatus</i> n. gen. n. sp., is described. The fish was found during the preparation of the theropod <i>Juravenator starki</i> Göhlich & Chiappe, 2006 in the same rock. The fish possesses numerous autapomorphies. The combination of autapomorphies is unique among Jurassic fishes and makes its taxonomic assignment difficult. The following characters are few examples demonstrating some of the peculiarities of the fish: The fish is small, oblong-shaped and has a large triangular head that is deeper than long; deepest point is at the level of the postparietal bone [parietal of traditional terminology] and the ventral end of the cleithrum. The skull roof is almost vertically oriented, with a strongly ossified and developed antero-dorsal orbital margin. Premaxilla and dentary possess very small conical teeth. The opercular apparatus is markedly narrow and deep. A clavicle is present. Both dorsal and ventral postcleithra are almost as deep as the maximum depth of the head; the dorsal postcleithrum is two times deeper than the ventral one. The vertebral centra are of arcocentral-type formed mainly by the development of the dorsal arcocentra. Pectoral and pelvic fins possess long rays that extend onto the pelvic and anal fins, respectively, whereas the rays of the dorsal and anal fins extend onto the caudal fin. The fish is interpreted as a macrosemiiform because it presents two of the three synapomorphies of the group (e.g., an incomplete circumorbital ring because the lateral edge of parietal bone [frontal of traditional terminology] makes up part of orbital margin and absence of a supramaxillary bone). The third macrosemiiform synapomorphy cannot be determined in the new fish because the coronoid bones and their dentition are not observed due to condition of preservation. The new fish shares a few characters with members of the families Macrosemiidae and the Uarbryichthyidae but lacks others so that presently, we place it in a family indeterminate within Macrosemiiformes. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.201200001" target="_blank">10.1002/mmng.201200001</a>

Standing Laparoscopic Peritoneal Flap Hernioplasty Technique for Preventing Recurrence of Acquired Strangulating Inguinal Herniation in Stallions

To describe a standing laparoscopic peritoneal flap hernioplasty (PFH) technique for closure of the vaginal ring, and to evaluate its effect on prevention of recurrent herniation in stallions, previously treated for acquired strangulating inguinal hernia (SIH). Case series. Stallions (n = 30) aged 3-15 that had previous acquired SIH. Bilateral standing laparoscopic PFH was performed on 30 stallions that had previous acquired SIH treated without castration. The vaginal rings were approached from 3 portals, 2 in the paralumbar fossa and a 3rd between the 17th and 18th ribs on the ipsilateral side. A large inverted U-shaped peritoneal flap was dissected from the abdominal wall proximal and cranial to the vaginal ring, reflected caudally over the vaginal ring, and secured to the abdominal wall with laparoscopic staples. In the first 11 stallions, only the cranial and mid third of the vaginal ring was covered. For the next 19 stallions, complete closure of the vaginal ring including the entire caudal aspect of the vaginal ring was achieved. SIH recurrence occurred in 4 of 11 stallions with incomplete ring closure whereas no SIH recurrence occurred when the entire vaginal ring was closed. No major complications occurred and cosmetic outcome was excellent. All breeding stallions were successfully used for breeding. Standing laparoscopic closure of the vaginal ring using a PFH is an effective way to prevent recurrence of SIH provided the entire vaginal ring, including the caudal aspect is covered by the flap. There seems to be no effect on subsequent fertility.

Examination Under Anesthetic for Occult Pelvic Ring Instability

To describe the technique and results of stress examination with fluoroscopy under anesthesia (EUA) to determine stability and the need for operative stabilization of traumatic pelvic ring injuries. Retrospective chart and radiographic review. Level I trauma center. Skeletally mature patients with traumatic incomplete posterior pelvic ring injuries. Patients were consented for EUA if preoperative radiographs and computed tomographic scanning of the pelvis demonstrated an incomplete injury to the posterior pelvic ring (Orthopaedic Trauma Association [OTA] 61-B type injuries). Patients with nondisplaced anterior compression fractures of the sacral ala without internal rotation or a fracture line exiting the posterior cortex were excluded from this analysis. Similarly, skeletally immature patients or those with complete instability of the pelvic ring (OTA 61-C type injuries) were excluded. All patients meeting inclusion criteria were taken to the operating room, anesthetized, and placed in the supine position for stress examination (EUA) of the pelvic ring using intraoperative dynamic fluoroscopy. Examination consisted of a resting static film followed by internal rotation, external rotation, and push-pull maneuvers of both lower extremities. Each of these maneuvers was performed using the anteroposterior, inlet, and outlet projections, providing a total of 15 distinct images for each patient's examination. The preoperative classification of the pelvic ring injury was then accepted or redefined based on the amount of rotational and translational instability in the axial, coronal, and sagittal planes. The decision to proceed with anterior and/or posterior operative reduction and stabilization was subsequently based on the degree of pelvic ring instability noted during the EUA. A total of sixty-eight patients underwent an EUA of their pelvis by the senior author. Fifty males and 18 females with an average age of 35 years comprised the study group. In all, 37 anteroposterior compression (APC or OTA 61-B1) injuries and 31 lateral compression (LC or OTA 61-B2) injuries were evaluated. Of the 14 pelvic ring injuries initially classified as an APC-1, seven (50%) were deemed stable and treated nonsurgically, whereas seven (50%) were felt to have sufficient instability (an occult APC-2) to warrant treatment with anterior fixation based on EUA. Of the 23 injuries initially classified as an APC-2, all but one required surgical fixation: 13 (57%) were treated with anterior fixation alone (APC-2a), whereas nine (39%) were treated with anterior fixation and supplemental iliosacral screw placement (APC-2b) based on the degree of instability noted during the EUA. Of the 20 injuries initially classified as an LC-1, 13 (65%) were stable and treated nonsurgically (LC-1a), whereas seven (35%) were treated with anterior and/or posterior stabilization (LC-1b) based on the degree of instability noted during the EUA. The reported incidence of poor functional outcomes associated with pelvic fracture may be attributable, in part, to inadequate treatment of misdiagnosed injuries and chronic instability and/or malunion. Performing an examination under anesthesia with dynamic stress fluoroscopy as described in this series revealed occult instability in 50% of presumed APC-1 injuries, 39% of APC-2 injuries, and 37% of LC-1 injuries. We propose a modification to the Young-Burgess Classification system to reflect the dynamic component of pelvic ring instability disclosed on EUA as follows: APC-2a for those injuries requiring anterior only fixation, APC-2b for those injuries that may require treatment with anterior and posterior fixation, LC-1a for those injuries that are stable and do not require internal fixation, and LC-1b for those lateral compression injuries that may require treatment with internal fixation. We conclude that pelvic EUA merits further analysis as an important diagnostic tool that may provide additional information regarding instability of the pelvic ring.

Progressive Aphasia and Vision Loss in a Teen-Aged Girl

A 16-year-old female honor student presented for evaluation of vertigo, headache, mild aphasia, and blurred vision. Her symptoms started approximately 2 months earlier when she experienced 3–4 days of intense vertigo and ear pain that waxed and waned and then gradually subsided. Her bifrontal headache initially was intermittent, but over the next several months, increased in severity and duration and by the time of presentation had become persistent. Her family indicated that she understood language normally but was having increasing difficulty with word finding. Visual symptoms were vaguely characterized as blurriness with intermittent diplopia. She occasionally stumbled while walking, which she attributed to difficulty seeing. She had no significant medical history. The patient was assessed at another hospital where brain MRI was abnormal. Lumbar puncture revealed a protein of 53 mg/dL (normal, 14–45 mg/dL), glucose of 36 mmol/L (normal, 50–80 mmol/L), 1 leukocyte, and 1 erythrocyte. The opening pressure was not recorded, and cytological examination was not performed. IgG index was normal, and oligoclonal bands were absent. Other unremarkable CSF studies included polymerase chain reaction (PCR) for herpes simplex viruses 1 and 2, cytomegalovirus, and JC virus, assay for myelin basic protein, and staining for acidfast bacillus. Serologic and blood studies were negative or normal, including white blood cell count, hemoglobin, hematocrit, platelet count, ferritin level, angiotensin-converting enzyme, anti-nuclear antibody, single-stranded DNA, double-stranded DNA antibody, PCR for human immunodeficiency virus, rapid plasma reagin, rheumatoid factor, very long-chain fatty acids, Lyme disease, and aquaporin-4 channel antibodies. When evaluated at our institution, the patient’s visual acuity was 20/20 in each eye with no relative afferent pupillary defect. Extraocular motility showed slight limitation of abduction of the left eye. External examination, anterior segment examination, and intraocular pressure were normal in both eyes. Dilated fundus examination revealed moderate bilateral optic disc swelling (Fig. 1). There was no evidence of vitritis or other posterior segment abnormalities. Automated perimetry revealed a right homonymous hemianopia and a left inferior homonymous quadrantanopia (Fig. 2). The patient had normal vital signs and was afebrile. No abnormalities were found on general physical examination. Neurologic examination revealed normal sensation and strength in the face and extremities. Cerebellar function, deep-tendon reflexes, and gait were normal. The patient’s speech was moderately fluid with poor naming of lowfrequency objects. Comprehension was moderate with slowing during 3-step commands. Reading was poor, and she was able to write only simple sentences. Brain MRI was obtained.

Light microscopic and immunohistochemical study of the trachea of the broad-snouted caiman (Caiman latirostris)

The purpose of this study was to examine the tracheal structure of the crocodile Caiman latirostris using light microscopy, histochemical and immunocytochemical techniques. The tracheal epithelium of C. latirostris consists of a ciliated pseudostratified columnar epithelium with goblet cells. The respiratory epithelium also includes endocrine cells immunoreactive to serotonin. The histochemical techniques demonstrated the presence of neutral and sulphated mucins secreted by goblet cells. The lamina propria consists of connective tissue with many reticular fibres. The elastic fibres are interspersed among collagen bundles, forming the border between the mucosa and the submucosa. The submucosal layer consists of connective tissue similar to that found in the lamina propria. Serous or mucous glands were not observed. The predominant characteristic in the adventitia is the presence of an incomplete hyaline cartilage ring, in the form of a circle. Dense connective tissue fills the space between the extremities of each cartilage ring. Serotonin-immunoreactive cells frequently had an apical cytoplasmic process directed towards the lumen, and were therefore classified as open type. The α-actin immunohistochemistry revealed smooth muscle cells only in blood vessel walls, confirming the absence of a tracheal muscle.

Vasculature and neurovascular relationships of the trigeminal nerve root

Specific microanatomical characteristics of the trigeminal nerve root (TNR) blood supply and close neurovascular relationships with surrounding vessels as well as their possible clinical significance were the main reasons for this study. The vasculature of 25 adult and four fetal TNRs were microdissected and examined under the stereoscopic microscope, after injecting their arteries with India ink. The trigeminal vessels, which varied between two and five in number, arose from two or three of the following arteries: the superolateral pontine (92%), anterior inferior cerebellar (AICA) (88%), inferolateral pontine (72%), and superior cerebellar (SCA) (12%). The trigeminal vascular twigs had a mean diameter of 0.215mm. A single vessel may supply either the motor portion of the nerve root or the sensory portion or both. The trigeminal vasculature formed the proximal and distal rings. The proximal ring was located at the trigeminal root entry zone. Its central branches extended along the TNR to the principal sensory and motor trigeminal nuclei while its peripheral longitudinal twigs followed the TNR fascicles. The incomplete distal arterial ring embraced the middle portion of the TNR before the level of its entrance into the arachnoid sleeve. The most frequent contact of the TNR was noticed with the SCA (20%), the petrosal or Dandy's vein (24%), and the AICA (12%). The observed characteristics of the TNR vasculature could be the anatomical basis for decompressive neurovascular surgery.