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Adjacent Structures (adjacent + structure)
Selected AbstractsShould direct mesocolon invasion be included in T4 for the staging of gastric cancer?JOURNAL OF SURGICAL ONCOLOGY, Issue 3 2010Jung Hoon Park MD Abstract Background and Objectives One of the sites most frequently invaded by gastric cancer is the mesocolon; however, the UICC does not mention this anatomical site as an adjacent structure involved in gastric cancer. The purpose of this study was to characterize and classify mesocolon invasion from gastric cancer. Methods We examined 806 patients who underwent surgery for advanced gastric carcinoma from 1992 to 2007 at the Department of Surgery, Gangnam Severance Hospital, Korea. Among these, patients who showed macroscopically direct invasion into the mesocolon were compared to other patients with advanced gastric cancer. Results The curability, number and extent of nodal metastasis, and the survival of the mesocolon invasion group were significantly worse than these factors in the T3 group. However, the survival of the mesocolon invasion group after curative resection was much better than that of patients who had incurable factors. Conclusions Mesocolon invasion should be included in T4 for the staging of gastric cancer. J. Surg. Oncol. 2010; 101:205,208. © 2010 Wiley-Liss, Inc. [source] Comparison of Endovenous Radiofrequency Versus 810 nm Diode Laser Occlusion of Large Veins in an Animal ModelDERMATOLOGIC SURGERY, Issue 1 2002Robert A. Weiss MDArticle first published online: 27 FEB 200 background. Endovenous occlusion using radiofrequency (RF) energy has been shown to be effective for the elimination of sapheno-femoral reflux and subsequent elimination of varicose veins. Recently, endovenous laser occlusion has been introduced with initial clinical reports indicating effective treatment for varicose veins. However, in our practice we note increased peri-operative hematoma and tenderness with the laser. Little is known regarding the mechanism of action of this new laser vein therapy. objective. To better understand the mechanism of action of endovenous laser vs. the endovenous RF procedure in the jugular vein of the goat model. methods. A bilateral comparison was performed using 810 nm diode laser transmitted by a bare-tipped optical fiber vs. the RF delivery by engineered electrodes with a temperature feedback loop using a thermocouple (Closure procedure) in three goat jugular veins. Immediate and one-week results were studied radiographically and histologically. Temperature measurements during laser treatment were performed by using an array of up to five thermocouples, spaced 2 mm apart, placed adjacent to a laser fiber tip during goat jugular vein treatment. results. Immediate findings showed that 100% of the laser-treated veins showed perforations by histologic examination and immediate contrast fluoroscopy. The RF-treated side showed immediate constriction with maintenance of contrast material within the vein lumen and no perforations. The difference in acute vein shrinkage was also dramatic as laser treatments resulted in vein shrinkage of 26%, while RF-treated veins showed a 77% acute reduction in diameter. At one week, extravasated blood that leaked into the surrounding tissue of laser treated veins acutely, continued to occupy space and impinge on surrounding structures including nerves. For the laser treatment, the highest average temperature was 729°C (peak temperature 1334°C) observed flush with the laser fiber tip, while the temperature feedback mechanism of the RF method maintains temperatures at the electrodes of 85°C. conclusion. Vein perforations, extremely high intravascular temperatures, failure to cause significant collagen shrinkage, and intact endothelium in an animal model justify a closer look at the human clinical application of the 810 nm endovenous laser technique. Extravasated blood impinging on adjacent structures may theoretically lead to increased peri-operative hematoma and tenderness. Further study and clinical investigation is warranted. [source] Medical imaging and MRI in nail disorders: report of 119 cases and review of the literatureDERMATOLOGIC THERAPY, Issue 2 2002Bertrand Richert Radiographs remain the golden standard for exploration of the bony structures located beneath the nail plate, but they provide no information on the perionychium. Until a few years ago the nail apparatus was deprived of investigative medical imaging. Glomus tumor was the only condition that was explored using invasive techniques such as angiography or scintigraphy. High-frequency ultrasound rapidly came up against technical limits. High-resolution magnetic resonance imaging (MRI) offers a superior alternative in detection of distal lesions as well as their relationship with the adjacent structures. MRI provides an accurate analysis of the nail apparatus with detection of lesions as small as 1 mm. This noninvasive technique will allow us to better understand, diagnose, and treat pathologies of the distal phalanx. [source] A Hertz contact model with non-linear damping for pounding simulationEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 7 2006Susendar Muthukumar Abstract This paper investigates the cogency of various impact models in capturing the seismic pounding response of adjacent structures. The analytical models considered include the contact force-based linear spring, Kelvin and Hertz models, and the restitution-based stereomechanical approach. In addition, a contact model based on the Hertz law and using a non-linear hysteresis damper (Hertzdamp model) is also introduced for pounding simulation. Simple analytical approaches are presented to determine the impact stiffness parameters of the various contact models. Parameter studies are performed using two degree-of-freedom linear oscillators to determine the effects of impact modelling strategy, system period ratio, peak ground acceleration (PGA) and energy loss during impact on the system responses. A suite of 27 ground motion records from 13 different earthquakes is used in the analysis. The results indicate that the system displacements from the stereomechanical, Kelvin and Hertzdamp models are similar for a given coefficient of restitution, despite using different impact methodologies. Pounding increases the responses of the stiffer system, especially for highly out-of-phase systems. Energy loss during impact is more significant at higher levels of PGA. Based on the findings, the Hertz model provides adequate results at low PGA levels, and the Hertzdamp model is recommended at moderate and high PGA levels. Copyright © 2006 John Wiley & Sons, Ltd. [source] Pounding of structures modelled as non-linear impacts of two oscillatorsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 5 2001K. T. Chau Abstract A new formulation is proposed to model pounding between two adjacent structures, with natural periods T1 and T2 and damping ratios ,1 and ,2 under harmonic earthquake excitation, as non-linear Hertzian impact between two single-degree-of-freedom oscillators. For the case of rigid impacts, a special case of our analytical solution has been given by Davis (,Pounding of buildings modelled by an impact oscillator' Earthquake Engineering and Structural Dynamics, 1992; 21:253,274) for an oscillator pounding on a stationary barrier. Our analytical predictions for rigid impacts agree qualitatively with our numerical simulations for non-rigid impacts. When the difference in natural periods between the two oscillators increases, the impact velocity also increases drastically. The impact velocity spectrum is, however, relatively insensitive to the standoff distance. The maximum relative impact velocity of the coupled system can occur at an excitation period Tn* which is either between those of the two oscillators or less than both of them, depending on the ratios T1/T2 and ,1/,2. Although the pounding force between two oscillators has been primarily modelled by the Hertz contact law, parametric studies show that the maximum relative impact velocity is not very sensitive to changes in the contact parameters. Copyright © 2001 John Wiley & Sons, Ltd. [source] Injection of the insertion of the deep digital flexor tendon in horses using radiographic guidanceEQUINE VETERINARY EDUCATION, Issue 7 2008J. D. C. Anderson Summary Insertional tendinopathies of the DDFT have been reported both as the sole lesion and as part of a multifocal lesion (Dyson et al. 2003). Computed tomography (CT) and magnetic resonance imaging allow specific diagnosis of deep digital flexor tendon lesions within the hoof capsule; however, direct intralesional treatment of such lesions is difficult because of the hoof's rigid structure. A technique designed to mimic intralesional injection of insertional tendinopathies of the DDFT in the standing horse using radiographic guidance was assessed. Radiographic and contrast CT imaging and sectioning of the limbs confirmed accurate injection in all cases although inadvertant administration of injectate into adjacent structures was also evident. [source] Subcutaneous angioleiomyomas: Gray-scale and color Doppler sonographic appearancesJOURNAL OF CLINICAL ULTRASOUND, Issue 2 2006Vanesa Gomez-Dermit MD Abstract Purpose: To describe the gray-scale Doppler and sonographic features of a series of subcutaneous angioleiomyomas. Methods: The sonographic appearances of 10 pathologically proven angioleiomyomas were retrospectively reviewed; 4 in women and 6 in men, with an age range from 33 to 77 years. We evaluated size, shape, echo pattern, margins, location, relationships with adjacent structures, and vascularity. Examinations were performed using a multifrequency linear array transducer (9,11 MHz) connected to a Logiq 500 scanner (GE, Milwaukee, Wl). Results: All tumors were subcutaneous and located in the extremities (7 in the lower extremities, 3 in the upper extremities). The sizes ranged from 0.6 to 6.4 cm, with an average size of 2 cm. All of the lesions were hypoechoic with well-defined margins, and 9 were oval. Intratumoral calcifications were observed in two patients. Vascularity was easily detected in all of them, and 4 tumors had a clear vascular pedicle. The spectral Doppler analysis performed in 5 cases, revealing a low-resistance arterial waveform in 4 patients. Conclusions: Although angioleiomyomas are uncommon soft tissue tumors, the presence of a well-defined, hypoechoic, vascular subcutaneous tumor in the extremities should raise the possibility of such a diagnosis. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 34:50,54, 2006 [source] Electrophysiological mapping for the implantation of deep brain stimulators for Parkinson's disease and tremorMOVEMENT DISORDERS, Issue S14 2006Robert E. Gross MD Abstract The vast majority of centers use electrophysiological mapping techniques to finalize target selection during the implantation of deep brain stimulation (DBS) leads for the treatment of Parkinson's disease and tremor. This review discusses the techniques used for physiological mapping and addresses the questions of how various mapping strategies modify target selection and outcome following subthalamic nucleus (STN), globus pallidus internus (GPi), and ventralis intermedius (Vim) deep brain stimulation. Mapping strategies vary greatly across centers, but can be broadly categorized into those that use microelectrode or semimicroelectrode techniques to optimize position prior to implantation and macrostimulation through a macroelectrode or the DBS lead, and those that rely solely on macrostimulation and its threshold for clinical effects (benefits and side effects). Microelectrode criteria for implantation into the STN or GPi include length of the nucleus recorded, presence of movement-responsive neurons, and/or distance from the borders with adjacent structures. However, the threshold for the production of clinical benefits relative to side effects is, in most centers, the final, and sometimes only, determinant of DBS electrode position. Macrostimulation techniques for mapping, the utility of microelectrode mapping is reflected in its modification of electrode position in 17% to 87% of patients undergoing STN DBS, with average target adjustments of 1 to 4 mm. Nevertheless, with the absence of class I data, and in consideration of the large number of variables that impact clinical outcome, it is not possible to conclude that one technique is superior to the other in so far as motor Unified Parkinson's Disease Rating Scale outcome is concerned. Moreover, mapping technique is only one out of many variables that determine the outcome. The increase in surgical risk of intracranial hemorrhage correlated to the number of microelectrode trajectories must be considered against the risk of suboptimal benefits related to omission of this technique. © 2006 Movement Disorder Society [source] Classic pyomyositis of the extremities as an unusual manifestation of Blastomyces dermatitidis: a report of two casesMYCOSES, Issue 4 2010Michael Y. Lin Summary Pyomyositis is an infection of skeletal muscle that, by definition, arises intramuscularly rather than secondarily from adjacent infection. It is usually associated with bacterial infection, particularly Staphylcococcus aureus. Fungi are rare causes, and Blastomyces dermatitidis has not been reported previously. In this case series, we report two cases of pyomyositis caused by B. dermatitidis. Cases were prospectively identified through routine clinical care at a single academic referral hospital. Two patients with complaints of muscle pain and subacute cough were treated at our hospital in 2007. Both patients were found to have pyomyositis caused by B. dermatitidis, in the quadriceps muscles in one patient, and in the calf muscle in another , by radiological imaging and fungal culture. Both were also diagnosed with pneumonia caused by B. dermatitidis (presumptive in one, confirmed in the other). There was no evidence of infection of adjacent structures, suggesting that the route of infection was likely direct haematogenous seeding of the muscle. A review of the literature confirmed that although B. dermatitidis has been described as causing axial muscle infection secondary to adjacent infection such as vertebral osteomyelitis, our description of isolated muscle involvement (classic pyomyositis) caused by B. dermatitidis, particularly of the extremity muscles, is unique. We conclude that B. dermatitidis is a potential cause of classic pyomyositis. [source] Malaria and oral healthORAL DISEASES, Issue 4 2008FJ Owotade Half of the world population resides in malaria-prone areas, and the disease is responsible for more than a million deaths annually. This is apart from the economic impact of the disease through resources expended towards treatment and prevention and the loss of manpower. In addition to the overt clinical signs and symptoms, the association of malaria with other diseases such as tuberculosis and HIV infection has been described. However few studies have attempted to investigate its relationship to oral diseases. This review provides an overview of the relevance of malaria to the mouth and adjacent structures. The need for further research is also emphasized. [source] An aid to the dissection of a cyst in the floor of the mouth: a technical noteORAL SURGERY, Issue 1 2008V. Bhatt Abstract The dissection of cysts in the floor of the mouth is technically difficult. The dissection of a thin-walled large ranula invariably results in rupture and as a result subsequent dissection and removal of the cyst can be difficult. We describe a simple method to allow for easier dissection of the cyst following rupture, which reduces the risk of damage to adjacent structures. [source] Mucoepidermoid carcinoma of the thyroid gland showing marked ciliation suggestive of its pathogenesisPATHOLOGY INTERNATIONAL, Issue 11 2008Mizuo Ando Mucoepidermoid carcinoma of the thyroid gland is a rare tumor first described by Rhatigan et al. in 1977. Its pathogenesis is still controversial. With regard to its most likely origin, some authors have suggested that it arises directly from follicular epithelium whereas others have proposed that it arises from ultimobranchial body (diverticulum from the fourth pharyngeal pouch) remnants, also known as solid cell nests (SCN). Herein is reported a unique case of thyroid mucoepidermoid carcinoma. The patient, a 67-year-old man, presented with a non-tender thyroid mass and vocal cord fixation. The tumor was poorly defined, necessitating subtotal thyroidectomy with composite resection of the adjacent structures. Pathologically, the tumor cells had characteristics of mucoepidermoid carcinoma, along with layers of columnar cells showing marked ciliation resembling respiratory-type epithelium, suggesting that this rare tumor had originated from SCN. p63 immunopositivity in the tumor provided additional evidence for the pathogenesis. [source] Intraprostatic ethanol chemoablation via transurethral and transperineal injectionBJU INTERNATIONAL, Issue 1 2003M.K. Plante OBJECTIVES To further assess the safety and feasibility of prostatic chemoablation with ethanol and to address previous concerns associated with transperineal injection using a canine model. MATERIALS AND METHODS The study included 25 dogs; normal saline or 98% dehydrated ethanol were injected into the prostate using both routes, at volumes of 25,50% of the total prostate volume. The prostate and adjacent structures were examined grossly and histopathologically after the dogs were killed humanely at 4 h, 7 days and 12 weeks after injection. RESULTS Transperineal injection resulted in tissue necrosis in all prostates and significant extraprostatic necrosis in two of three animals treated. With transurethral injection, the control groups showed minimal change, whereas the group injected with ethanol resulted in lesions with variable necrosis and location. CONCLUSIONS Intraprostatic chemoablation is possible with ethanol injection both transperineally and transurethrally. Transperineal ethanol injections were associated with more extraprostatic necrosis. Transurethral injections resulted in larger amounts of necrosis in the prostatic parenchyma with minimal extraprostatic effects. However, the extent of prostatic necrosis/ablation was inconsistent and further research is warranted. [source] Reduced Activity of CD13/Aminopeptidase N (APN) in Aggressive Meningiomas Is Associated with Increased Levels of SPARCBRAIN PATHOLOGY, Issue 1 2010Christian Mawrin Abstract Meningiomas are the second most common brain tumors in adults, and meningiomas exhibit a tendency to invade adjacent structures. Compared with high-grade gliomas, little is known about the molecular changes that potentially underlie the invasive behavior of meningiomas. In this study, we examined the expression and function of the membrane alanyl-aminopeptidase [mAAP, aminopeptidase N (APN), CD13, EC3.4.11.2] zinc-dependent ectopeptidase in meningiomas and meningioma cell lines, based on its prior association with tumor invasion in colorectal and renal carcinomas. We found a significant reduction of APNmRNA and protein expression, as well as enzymatic activity, in high-grade meningiomas. While meningioma tumor cell proliferation was not affected by either pharmacologic APN inhibition or siRNA-mediated APN silencing, APN pharmacologic and siRNA knockdown significantly reduced meningioma cell invasion in vitro. Next, we employed pathway-specific cDNA microarray analyses to identify extracellular matrix and adhesion molecules regulated by APN, and found that APN-siRNA knockdown substantially increased the expression of secreted protein, acidic and rich in cysteine (SPARC)/osteonectin. Finally, we demonstrated that SPARC, which has been previously associated with meningioma invasiveness, was increased in aggressive meningiomas. Collectively, these results suggest that APN expression and enzymatic function is reduced in aggressive meningiomas, and that alterations in the balance between APN and SPARC might favor meningioma invasion. [source] Prognostic significance of RET and NTRK1 rearrangements in sporadic papillary thyroid carcinomaBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2000T. J. Musholt Background The genetic background of papillary thyroid carcinoma (PTC) has been elucidated by the identification of somatic translocations of the tyrosine kinases RET and NTRK1. Expression of RET/PTC chimeras has been demonstrated in 10,25 per cent of sporadic PTCs while rearrangements of NTRK1 were detected less frequently. Based upon the limited data available, some investigators have hypothesized that RET/PTC activation is preferentially associated with slow growing tumours of low malignancy in elderly patients, while other studies support the contrary. Methods Tumour tissues from 115 patients with sporadic PTC were harvested at operation and snap frozen. Following RNA extraction, expression analysis of the RET proto-oncogene as well as the NTRK1 gene was performed by multiplex reverse transcriptase,polymerase chain reaction. Samples with suspected rearrangements of the genes were further analysed for expression of the hybrid messenger RNAs RET/PTC1 to RET/PTC4, and for known NTRK1 chimeras. Clinical data of all patients were documented in an extensive database of thyroid carcinomas maintained by this research group. Results Twenty-one (18 per cent) of 115 tumour samples revealed somatic rearrangements of RET while translocations of the NTRK1 gene were demonstrated in 2 per cent of all samples analysed to date. The mean age of all patients was 52 (range 14,86, median 54) years and that of patients positive for RET rearrangements was 49 (range 14,82, median 49) years. Nine of 21 RET -rearranged tumours showed aggressive behaviour with locally invasive tumour growth and infiltration of adjacent structures such as muscles, vessels and trachea. Tumour samples without detectable RET translocations were associated with organ-exceeding tumour growth in only 20 per cent of cases. Conclusion These data represent one of the most comprehensive studies on gene translocations and their clinical significance in PTC. In accordance with international publications, an incidence of 2 per cent of NTRK1 rearrangements and 18 per cent of RET translocations is reported, which is in contrast to other national reports of low rearrangement rates. Somatic translocations were associated with tumours demonstrating aggressive behaviour in almost half of patients with PTC in all age groups, indicating a prognostic role of oncogenic RET/PTC activation. © 2000 British Journal of Surgery Society Ltd [source] Treatment of thoracic esophageal carcinoma invading adjacent structuresCANCER SCIENCE, Issue 7 2007Yasuyuki Seto T4 esophageal cancer is defined as the tumor invading adjacent structures, using tumor,node,metastasis (TNM) staging. For clinically T4 thoracic esophageal carcinoma, multimodality therapy, that is, neoadjuvant chemoradiotherapy (CRT) followed by surgery or definitive CRT, has generally been performed. However, the prognosis of patients with these tumors remains poor. Another strategy is needed to achieve curative treatment. In the present article, the treatment strategies employed to date are reviewed. Furthermore, the strategies for these malignancies are reassessed, based on our experiences. R1/2 and R0 resections are regarded as those with residual and no tumor after surgery. The present data show that patients who underwent R1/2 resection after neoadjuvant CRT experienced little survival benefit, while complete response (CR) cases after definitive CRT had comparatively better results. Therefore, curative surgery should not be attempted without down-staging, and definitive CRT should be the initial treatment. Then surgery is indicated for the eradication of residual cancer cells. Close surveillance is essential for early detection of relapse even after CR, because the operation will gradually become increasingly difficult due to post-CRT fibrosis. In conclusion, multimodality therapy consists of definitive CRT followed by R0 resection, which can be the treatment of choice for T4 esophageal carcinoma. These challenging treatments have the potential to constitute the most effective therapeutic strategy. (Cancer Sci 2007; 98: 937,942) [source] Parameters for Successful Implant Integration Revisited Part II: Algorithm for Immediate Loading Diagnostic FactorsCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2010FACD, Oded Bahat BDS ABSTRACT Immediate loading of dental implants has become a widely reported practice with success rates ranging from 70.8% to 100%. Although most studies have considered implant survival to be the only measure of success, a better definition includes the long-term stability of the hard and soft tissues around the implant(s) and other adjacent structures, as well as the long-term stability of all the restorative components. The parameters identified in 1981 by Albrektsson and colleagues as influencing the establishment and maintenance of osseointegration have been reconsidered in relation to immediate loading to improve the chances of achieving such success. Two of the six parameters (status of the bone/implant site and implant loading conditions) have preoperative diagnostic implications, whereas three (implant design, surgical technique, and implant finish) may compensate for less-than-ideal site and loading conditions. Factors affecting the outcome of immediate loading are reviewed to assist clinicians attempting to assess its risks and benefits. [source] | |||||||||||||||||||||||||