Canal Extension Research Articles

CCM-3/STRIPAK promotes seamless tube extension through endocytic recycling.

The mechanisms governing apical membrane assembly during biological tube development are poorly understood. Here, we show that extension of the C. elegans excretory canal requires cerebral cavernous malformation 3 (CCM-3), independent of the CCM1 orthologue KRI-1. Loss of ccm-3 causes canal truncations and aggregations of canaliculular vesicles, which form ectopic lumen (cysts). We show that CCM-3 localizes to the apical membrane, and in cooperation with GCK-1 and STRIPAK, promotes CDC-42 signalling, Golgi stability and endocytic recycling. We propose that endocytic recycling is mediated through the CDC-42-binding kinase MRCK-1, which interacts physically with CCM-3-STRIPAK. We further show canal membrane integrity to be dependent on the exocyst complex and the actin cytoskeleton. This work reveals novel in vivo roles of CCM-3·STRIPAK in regulating tube extension and membrane integrity through small GTPase signalling and vesicle dynamics, which may help explain the severity of CCM3 mutations in patients.

Type IV Aggressive and Symptomatic Vertebral Hemangioma

Vertebral hemangiomas (VHs) are benign tumours with rich vasculature. They are the most common tumours of the spine with an estimated incidence of 10% - 12% of the population. Despite its high incidence, they are often asymptomatic and only 0.9% - 1.2% are symptomatic. They may also be aggressive and are characterised by bone expansion, extra osseous extension of the tumour, disturbance of local blood flow and, in rare cases, compression fractures. We report a 59-year-old woman, presented with back pain after falling from standing height. Magnetic resonance imaging revealed lumbar spine vertebral fractures and T12 osteolytic lesion with spinal canal extension, concurring to VH type IV, according to Tomita’s surgical classification of spinal. Embolization, posterior decompression and fixation were performed followed by postoperative radiotherapy. Her symptoms were resolved immediately without recurrence after 6 mouths.

Evaluation of the Action of Chelating Agents on the Microhardness of Superficial Layer of Root Canal Lumen Dentin

ABSTRACT Aim To evaluate the effect of different chelating agents on the microhardness of the superficial dentin layer of the root canal lumen. Materials and methods Forty-two extracted single rooted teeth were instrumented, and the roots were longitudinally sectioned in a buccolingual direction to expose the entire canal extension. The specimens were randomly distributed in four groups according to the final irrigation: Glyde File Prep (Dentsply Maillefer, Ballaigues, Switzerland), RC Help (Prime Dental Pvt. Ltd, Mumbai, India), Endo Prep RC (Stedman Anabond, Chennai, India), Dolo Endogel (Prevest Denpro Ltd, Jammu, India). A standardized volume of 50 ml of each chelating agent was used for 5 minutes. Dentin microhardness was measured with a Knoop indenter under a 50 gm load and a 15 seconds dwell time. Data was analyzed statistically by one-way analysis of variance ANOVA and post hoc multiple-comparison test at 5% significance level. Results Statistically significant difference was detected among the chelating agents by one-way ANOVA. Glyde File Prep and Dolo Endogel chelating agents differed significantly (p < 0.0001) in reduction of dentin microhardness from RC help and Endo Prep RC. Conclusion Glyde File Prep and Dolo Endogel are significantly better than RC Help and Endo Prep RC in reducing dentin microhardness. How to cite this article Napte BD, Srinidhi SR. Evaluation of the Action of Chelating Agents on the Microhardness of Superficial Layer of Root Canal Lumen Dentin. World J Dent 2014;5(2):124-128.

Lower extremity pain as initial presentation of cervical cancer

IntroductionThe diagnosis of bone metastases in cervical cancer defines ad-vanced disease with a median overall survival of b1year(Matsuyamaetal.,1989;Abdul-Karimetal.,1990).Themostcommonbonesaffectedare the lumbar spine and pelvis; distal extremity metastases are rare,accounting for b5% of bone metastases (Ratanatharathorn et al., 1994;Rangarajanetal.,2010).High-dosepalliativeradiotherapyprovidessig-nificant symptomatic relief in approximately 67% of cervical cancer pa-tients(Matsuyamaetal.,1989).Theoverallclinicalandpersonalimpactofosseousfracturesforpatientshighlightstheimportanceofclearlyde-fining the management plan for osseous metastases in gynecologicalcancers.We report a woman who presented with back and lower ex-tremity pain, ultimately found to have cervical cancer. Despite mul-timodal therapy, the patient passed away 3 months after her initialpresentation. This case report also reviews the biology of bone me-tastases and presents some emerging therapeutic options for thesescenarios.Case reportThe patient was a previously healthy 36-year-old nulligravidawoman who presented with isolated back and right leg pain (RLE)fortwoweeks.ImagingworkupincludedX-rayandmagneticresonanceimaging (MRI) of the spine, which demonstrated multiple vertebralbody lesions with spinal canal extension at the T6 level (Fig. 1A);Tc99m bone scan redemonstrated the multiple spine and RLE lesions,including a large, distal right femoral lesion (Fig. 1B). Distal right ex-tremity X-rays and MRI were obtained to exclude pathologic fractureat this site (Fig. 1C). An anterior cortex, lytic lesion with associatedsoft tissue component was seen, without associated fracture. A subse-quent FDG-PET/CT (Fig. 1D) of the abdomen and pelvis demonstratedmultiple organ lesions and lymphadenopathy. Because the etiology ofthepresumeddiffusemetastaticdiseasewasunclear,thepatientsubse-quently underwent a CT-guided, core biopsy of the femur. Pathologyrevealed sheets of undifferentiated pleomorphic neoplastic cells withhigh nuclear/cytoplasmic (N:C) ratio, prominent nucleoli and nu-merous mitotic figures (Figs. 2A–C). The tumor cells stainedstrongly for cytokeratin (AE1/3) (Fig. 2D) and negative for CK7/CK20, S100, HMB45, synaptophysin, chromogranin, estrogen re-ceptor (ER), progesterone receptor (PR), thyroid transcriptionfactor-1 TTF1, CA125, renal cell marker, and calretinin. Becausethe primary site was still unidentifiable, excisional biopsy of thefemur lesion was performed. Pathology showed rare areas ofsquamous differentiation among nestsoftumorcellsimmunore-active for p63 (Fig. 2E) and CK5/6 (Fig. 2 F), consistent with apoorly-differentiated squamous cell carcinoma from either thelung, head and neck or uterine cervix. A pelvic examination re-vealed a single 2-cm erosive lesion on her anterior cervix, and acervical biopsy demonstrated a moderately-to-poorly differentiat-ed squamous cell carcinoma.Zoledronic acid was administered to slow the progression of thebone metastases, and surgical excision and internal fixation wereperformed to the femur. She also received palliative radiation therapy(20 Gy over 5 fractions to T4–T7 and 8 Gy in a single fraction toL5-sacrum). The patient received one cycle of systemic gemcitabine(1600 mg/m

Distinct Cell Guidance Pathways Controlled by the Rac and Rho GEF Domains of UNC-73/TRIO in Caenorhabditis elegans

The cytoskeleton regulator UNC-53/NAV2 is required for both the anterior and posterior outgrowth of several neurons as well as that of the excretory cell while the kinesin-like motor VAB-8 is essential for most posteriorly directed migrations in Caenorhabditis elegans. Null mutations in either unc-53 or vab-8 result in reduced posterior excretory canal outgrowth, while double null mutants display an enhanced canal extension defect, suggesting the genes act in separate pathways to control this posteriorly directed outgrowth. Genetic analysis of putative interactors of UNC-53 or VAB-8, and cell-specific rescue experiments suggest that VAB-8, SAX-3/ROBO, SLT-1/Slit, and EVA-1 are functioning together in the outgrowth of the excretory canals, while UNC-53 appears to function in a parallel pathway with UNC-71/ADAM. The known VAB-8 interactor, the Rac/Rho GEF UNC-73/TRIO operates in both pathways, as isoform specific alleles exhibit enhancement of the phenotype in double-mutant combination with either unc-53 or vab-8. On the basis of these results, we propose a bipartite model for UNC-73/TRIO activity in excretory canal extension: a cell autonomous function that is mediated by the Rho-specific GEF domain of the UNC-73E isoform in conjunction with UNC-53 and UNC-71 and a cell nonautonomous function that is mediated by the Rac-specific GEF domain of the UNC-73B isoform, through partnering with VAB-8 and the receptors SAX-3 and EVA-1.

Acoustic test fixture for insertion loss measurements of hearing protector devices.

According to ANSI standard S12.42 new aspects have to be considered when measuring the Insertion Loss of Hearing Protectors at an Acoustic Test Fixture. First, the ear simulator has to be able to measure up to 170 dB SPL, so a 1/4 in. microphone is needed. The ear canal extension is also longer than the standard extension known from KEMAR and is fitted with flesh simulation. The circumaural pinna has a larger diameter to ensure a perfect seal for all kinds of hearing protection devices (HPD). Furthermore, the total system consisting of ear simulator, ear canal extension, and pinna is heated to body temperature. All the effects of these new aspects have been measured to assess their influence compared to previous ATF types like the ISO 4869-3.

Effect of Chelating Solutions on the Microhardness of Root Canal Lumen Dentin

Introduction The greatest reduction in microhardness of the most superficial layer of dentin of the root canal lumen is desired. The use of chelating agents during biomechanical preparation of root canals removes smear layer, increasing the access of the irrigant into the dentin tubules to allow adequate disinfection, and also reduces dentin microhardness, facilitating the action of endodontic instruments. This study evaluated the effect of different chelating solutions on the microhardness of the most superficial dentin layer from the root canal lumen. Methods Thirty-five recently extracted single-rooted maxillary central incisors were instrumented, and the roots were longitudinally sectioned in a mesiodistal direction to expose the entire canal extension. The specimens were distributed in seven groups according to the final irrigation: 15% EDTA, 10% citric acid, 5% malic acid, 5% acetic acid, apple vinegar, 10% sodium citrate, and control (no irrigation). A standardized volume of 50 μL of each chelating solution was used for 5 minutes. Dentin microhardness was measured with a Knoop indenter under a 10-g load and a 15-second dwell time. Data were analyzed statistically by one-way analysis of variance and Tukey-Kramer multiple-comparison test at 5% significance level. Results EDTA and citric acid had the greatest overall effect, causing a sharp decrease in dentin microhardness without a significant difference ( p > .05) from each other. However, both chelators differed significantly from the other solutions ( p < .001). Sodium citrate and deionized water were similar to each other ( p > .05) and did not affect dentin microhardness. Apple vinegar, acetic acid, and malic acid were similar to each other ( p > .05) and presented intermediate results. Conclusion Except for sodium citrate, all tested chelating solutions reduced microhardness of the most superficial root canal dentin layer. EDTA and citric acid were the most efficient.

Intrinsic brainstem glioma mimicking an ependymoma

A 14-year-old child presented with complaints of headache, vomiting and complete vision loss for 1 month. Sagittal T1W and T2-W MR images of the brain revealed a posterior fossa tumor with cervical spinal canal extension consistent with ependymoma (Fig. 1). Intraoperatively, a moderately vascular intrinsic brainstem glioma was found with a dorsal exophytic component extending into the cervical canal to the C4 level with a caudal syrinx. Histopathology confirmed the diagnosis of pilocytic astrocytoma. Direct cervical intramedullary extension of a posterior fossa tumor is rare, and ependymoma has the greatest predilection for this pattern of spread. Leproux et al. [1] reported a case of cystic astrocytoma with spinal extension through the fourth ventricle outlet foramina. Although cervicomedullary glioma forms a distinct entity among brainstem gliomas, a direct intramedullary cervical canal extension of a posterior fossa pilocytic astrocytoma, as described in this case, is extremely unusual. The recognition of such an unusual spread is important, as cervicomedullary variants of brainstem glioma are relatively benign and radical removal is associated with improved survival [2].

Microsurgical Treatment of Meningiomas of the Cerebellopontine Angle with Internal Auditory Canal Extension

Microsurgical Treatment of Meningiomas of the Cerebellopontine Angle with Internal Auditory Canal Extension

EFFECT OF EARLY OPTIC CANAL UNROOFING ON THE OUTCOME OF VISUAL FUNCTIONS IN SURGERY FOR MENINGIOMAS OF THE TUBERCULUM SELLAE AND PLANUM SPHENOIDALE

The aim of this study was to evaluate the effect of early optic canal unroofing on visual function in patients with meningiomas of the tuberculum sellae and planum sphenoidale. We retrospectively reviewed the clinical records of 20 consecutive patients with tuberculum sellae meningiomas and two patients with planum sphenoidale meningiomas who were admitted to our institution from 1999 to 2007. Factors that may influence postoperative visual functions were analyzed, including patient's age and sex, duration of preoperative visual symptoms, preoperative visual acuity, tumor size, tumor consistency, tumor extension into the optic canal, tumor adhesion to the optic nerve, timing of optic canal unroofing, and tumor resection rate. The mean patient age was 52.9 +/- 13.7 years (range, 27-73 yr); 18 patients were women and four were men. The mean maximum tumor size was 2.3 +/- 0.7 cm (range, 1.5-3.5 cm). Visual symptoms were present preoperatively in 19 patients, and three patients were asymptomatic. The mean duration of visual symptoms was 12.0 +/- 16.4 months (range, 0-72 mo). Tumor resection was evaluated according to Simpson's grade, and Grade II was achieved in 14, Grade III in two, and Grade IV in six (two patients were recurrent cases). Tumors were extended into the optic canal in 15 patients, and severe adhesion to the optic nerve was observed in nine patients. Tumor consistency was soft in eight patients, intermediate in eight patients, and hard in six patients. The optic canal was unroofed early before dissection or manipulation of tumor in nine patients (early group) and after dissection of tumor in seven patients (late group), and optic canal unroofing was not performed in six patients (none group; no canal extension in two and intentional incomplete resection in four patients). Visual symptoms were improved in 10 patients, unchanged in seven patients, and worsened in five patients (transient in two and permanent in three). Logistic regression analysis revealed that early optic canal unroofing was an independent factor for postoperative improvement of visual symptoms. Early optic canal unroofing may increase the possibility of improved preoperative visual symptoms in surgical resection of tuberculum sellae meningiomas and planum sphenoidale meningiomas.

Unusual magnetic resonance characteristics of a cerebellopontine angle epidermoid cyst with upper cervical spinal canal extension

We present a 27-year-old woman with an epidermoid cyst at the cerebellopontine (CP) angle with caudal extension into the upper cervical spinal canal. The lesion showed unusual hyperintensity on T1-weighted images, and hypointensity on T2-weighted images. We used microneurosurgical techniques for tumour dissection and excision. To our knowledge, this is the fifth example in Index Medicus/MEDLINE of histopathologically proven CP angle epidermoid with cervical spine extension.

Measurement of Endocervical Canal Extension of the Transformation Zone on Fresh Hysterectomy Specimens

Determine the extent of endocervical canal extension of the transformation zone on fresh hysterectomy specimens. After removal for standard gynecologic indications, 201 uteri were evaluated in the pathology accessioning area of a community hospital before formalin fixation. Uteri were opened in standard fashion. The length of the endocervical canal and the distance from the external cervical os to the most cranial extension of the squamocolumnar junction (SCJ) into the canal were measured grossly to the nearest millimeter. Patient age, menopausal status, and indication for surgery were extracted from the pathology consultation sheet. The upper limit of the SCJ was located within the canal in 188 of 201 cases (93.5%), including 152 of 162 premenopausal cases (93.8%), 25 of 27 postmenopausal cases (92.6%), and 11 of 12 cases of unknown postmenopausal status (91.7%). The mean distance of SCJ extension was 3.8 mm (SD, 2.5 mm), with a trend toward a shorter distance in the postmenopausal women. The SCJ distance was > or =10 mm in 5 of 188 women (2.7%), all of whom were premenopausal, and > or =5 mm in 41 of 188 women (21.8%). Among women with SCJ extension into the canal, the mean canal length was 33.2 mm (SD, 5.4 mm) for the premenopausal women and 28.3 mm (SD, 5.6 mm) for the postmenopausal women (p < .001). Postmenopausal status and advancing age were not associated with an increased depth of the SCJ into the endocervical canal. The high rates of unsatisfactory colposcopy reported for postmenopausal women are more likely the result of anatomic changes precluding visualization of the canal rather than the skill of the colposcopist. A device designed to detect cervical intraepithelial neoplasia within the cervical canal should be capable of evaluating to a depth exceeding 5 mm.

Carcinoma do esôfago com invasão do canal medular: relato de caso e revisão da literatura

Os autores apresentam o caso de paciente do sexo masculino, 62 anos de idade, com emagrecimento há quatro meses e diminuição da força muscular associada a parestesias em membros inferiores há dois dias. Foi submetido a mielotomografia, que demonstrou massa no mediastino posterior com destruição dos corpos vertebrais e invasão do canal medular, além de espessamento irregular das paredes do esôfago. Na evolução, foi submetido a estudo contrastado do esôfago, que demonstrou falha de enchimento irregular. A biópsia confirmou a presença de carcinoma de células escamosas. Este é o primeiro relato na literatura latino-americana (Lilacs) de carcinoma de esôfago com invasão de canal medular e manifestação inicial de síndrome de compressão medular.

Routine brain imaging is unwarranted in asymptomatic patients with rhabdomyosarcoma arising outside of the head and neck region that is metastatic at diagnosis: a report from the Intergroup Rhabdomyosarcoma Study Group.

To the authors' knowledge, the incidence of brain metastases at the time of diagnosis in children with metastatic rhabdomyosarcoma (RMS) arising outside the head and neck region is unknown, and routine imaging to identify metastatic brain involvement is costly. The authors retrospectively reviewed the results of computed tomography (CT) or magnetic resonance imaging (MRI) scans of the head, which was mandated by protocol, in patients with metastatic RMS arising outside the head and neck region who were enrolled on the fourth Intergroup Rhabdomyosarcoma Study (IRS-IV; 1991--1997). Of 100 eligible patients with metastatic RMS arising outside the head and neck region, 56 (56%) underwent head CT (n = 51) and/or MRI (n = 11) scans. Seven of these 56 patients (12.5%) had abnormal scans. Three patients with physical findings suggesting head or neck pathology underwent imaging that confirmed the presence of metastases in bone (one patient), orbit (one patient), or lymph nodes (one patient). One patient who presented with seizures had imaging findings consistent with cerebral embolic infarctions. Of three asymptomatic patients, one had bone metastases that also were identified on skeletal survey and one had bone metastases in the base of the skull that were not identified on bone scan. The remaining asymptomatic patient had a retroperitoneal paraspinal tumor with spinal canal extension and subsequently developed leptomeningeal disease dissemination. Brain metastases are uncommon at the time of initial diagnosis of metastatic RMS arising outside the head and neck region, and the majority of abnormalities detected on head CT or MRI scans are evident clinically or on other imaging studies. Patients with clinical findings suggesting intracranial pathology and those with paraspinal tumors may benefit from brain imaging, but cost savings may be realized by foregoing imaging in patients without these features.

Spinal canal extension of hyperalimentation catheter without neurologic sequela

An attempt at placement of a left femoral vein hyperalimentation catheter resulted in entrance of the catheter into the spinal canal. Catheter location was documented by injections of nonionic contrast material into the catheter without neurologic sequellae.

Neurogenic Tumors of the Thorax

Neurogenic tumors of the thorax are observed in all age groups, although they are rare in the elderly. They are more likely to be malignant in the child than in the adult. Tumors of the autonomic system are common in children, whereas the nerve sheath tumors are more likely to be found in adults. The malignant lesions are almost always symptomatic and the benign lesions asymptomatic, except in the child, in whom a benign lesion may result in symptoms because of its size relative to the volume of the child's thorax. Intraspinal canal extension, although relatively infrequent, should be sought for in all paravertebral tumors, for a significant percentage of these may be initially asymptomatic. Excision of such an hourglass tumor without foreknowledge of such extension may lead to serious spinal cord complications. Surgical excision of most of these tumors is sufficient except for the malignant lesions, especially in infancy and childhood, for which the addition of postoperative irradiation and chemotherapy may be beneficial. The prognosis after the removal of benign neurogenic tumors of the thorax is excellent. In the infant or child with Stage III or IV neuroblastoma, ganglioneuroblastoma, or an Askin tumor, the prognosis is poor. In the adult with a malignant neurogenic sarcoma or a malignant paraganglioma, the prognosis likewise is grave.