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1.
J Am Acad Dermatol ; 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37992812

RESUMO

BACKGROUND: Anti-p200 pemphigoid is a subepidermal autoimmune blistering disease (AIBD) characterized by autoantibodies against a 200 kDa protein. Laminin γ1 has been described as target antigen in 70% to 90% of patients. No diagnostic assay is widely available for anti-p200 pemphigoid, which might be due to the unclear pathogenic relevance of anti-laminin γ1 autoantibodies. OBJECTIVE: To identify a target antigen with higher clinical and diagnostic relevance. METHODS: Immunoprecipitation, mass spectrometry, and immunoblotting were employed for analysis of skin extracts and sera of patients with anti-p200 pemphigoid (n = 60), other AIBD (n = 33), and healthy blood donors (n = 29). To localize the new antigen in skin, cultured keratinocytes and fibroblasts, quantitative real-time polymerase chain reaction and immunofluorescence microscopy were performed. RESULTS: Laminin ß4 was identified as target antigen of anti-p200 pemphigoid in all analyzed patients. It was located at the level of the basement membrane zone of the skin with predominant expression in keratinocytes. LIMITATIONS: A higher number of sera needs to be tested to verify that laminin ß4 is the diagnostically relevant antigen of anti-p200 pemphigoid. CONCLUSION: The identification of laminin ß4 as an additional target antigen in anti-p200 pemphigoid will allow its differentiation from other AIBD and as such, improve the management of these rare disorders.

2.
Anat Sci Educ ; 16(5): 814-829, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37183973

RESUMO

Hands-on courses utilizing preserved human tissues for educational training offer an important pathway to acquire basic anatomical knowledge. Owing to the reevaluation of formaldehyde limits by the European Commission, a joint approach was chosen by the German-speaking anatomies in Europe (Germany, Austria, Switzerland) to find commonalities among embalming protocols and infrastructure. A survey comprising 537 items was circulated to all anatomies in German-speaking Europe. Clusters were established for "ethanol"-, formaldehyde-based ("FA"), and "other" embalming procedures, depending on the chemicals considered the most relevant for each protocol. The logistical framework, volumes of chemicals, and infrastructure were found to be highly diverse between the groups and protocols. Formaldehyde quantities deployed per annum were three-fold higher in the "FA" (223 L/a) compared to the "ethanol" (71.0 L/a) group, but not for "other" (97.8 L/a), though the volumes injected per body were similar. "FA" was strongly related to table-borne air ventilation and total fixative volumes ≤1000 L. "Ethanol" was strongly related to total fixative volumes >1000 L, ceiling- and floor-borne air ventilation, and explosion-proof facilities. Air ventilation was found to be installed symmetrically in the mortuary and dissection facilities. Certain predictors exist for the interplay between the embalming used in a given infrastructure and technical measures. The here-established cluster analysis may serve as decision supportive tool when considering altering embalming protocols or establishing joint protocols between institutions, following a best practice approach to cater toward best-suited tissue characteristics for educational purposes, while simultaneously addressing future demands on exposure limits.


Assuntos
Anatomia , Humanos , Fixadores , Anatomia/educação , Embalsamamento/métodos , Cadáver , Formaldeído/química , Etanol
3.
Neurol Genet ; 7(4): e608, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34250228

RESUMO

OBJECTIVE: Our study investigated the presence of regional differences in hexanucleotide repeat number in postmortem brain tissues of 2 patients with X-linked dystonia-parkinsonism (XDP), a combined dystonia-parkinsonism syndrome modified by a (CCCTCT)n repeat within the causal SINE-VNTR-Alu retrotransposon insertion in the TAF1 gene. METHODS: Genomic DNA was extracted from blood and postmortem brain samples, including the basal ganglia and cortex from both patients and from the cerebellum, midbrain, and pituitary gland from 1 patient. Repeat sizing was performed using fragment analysis, small-pool PCR-based Southern blotting, and Oxford nanopore sequencing. RESULTS: The basal ganglia (p < 0.001) and cerebellum (p < 0.001) showed higher median repeat numbers and higher degrees of repeat instability compared with blood. CONCLUSIONS: Somatic repeat instability may predominate in brain regions selectively affected in XDP, thereby hinting at its potential role in disease manifestation and modification.

4.
Ann Anat ; 227: 151415, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31513915

RESUMO

BACKGROUND: The phrenicoabdominal branch of the left phrenic nerve passes between muscle fiber bundles within the costal part of the diaphragm near the pericardium. In most German textbooks of anatomy, however, its passage is described to be found in the esophageal hiatus. The aim of this study was to reevaluate its topography relative to the diaphragm in a multicentric study and to identify the initiation of this description. METHODS: In this multicentric study, the most dorsomedial branch of the left phrenic nerve was identified as the phrenicoabdominal branch in 400 embalmed anatomic specimens of Caucasian origin. The distance between its passage and the apex of the pericardium, the left border of the esophageal hiatus, and the inner aspect of the left sixth rib was measured on the cranial aspect of the diaphragm. Textbooks on human anatomy published in German language between 1700 and 2018 were reviewed for their description of the passage of the left phrenicoabdominal branch through the diaphragm. RESULTS: The first statement on the passage of the left phrenicoabdominal branch through the esophageal hiatus was given in 1791 by Sömmering. Since then, in German textbooks of anatomy, a duality in the description of the passage of the left phrenicoabdominal branch persists. In none of the individuals examined in this study, the left phrenicoabdominal branch passed through the esophageal hiatus. In 99.5% of all cases, it pierced the costal part of the diaphragm dorsal to or at the same level as the apex of the pericardium. The mean distances (standard deviations) were 3.4 (±1.5) cm to the apex of the pericardium, 5.8 (±2.2) cm to the esophageal hiatus, and 5.5 (±1.6) cm to the inner aspect of the left sixth rib. CONCLUSION: The findings on the position of the left phrenicoabdominal branch relative to the diaphragm help to improve topographical knowledge and prevent inadvertent nerve injury during surgical interventions on or near the diaphragm. Further to this, these results may form a substantial basis to adopt the correct description of the passage of the left phrenicoabdominal branch to anatomical textbook knowledge.


Assuntos
Diafragma/anatomia & histologia , Esôfago/anatomia & histologia , Nervo Frênico/anatomia & histologia , Anatomia/história , Cadáver , Embalsamamento , Feminino , Alemanha , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Masculino , Pericárdio/anatomia & histologia , Costelas/anatomia & histologia , Livros de Texto como Assunto/história , População Branca
5.
Ann Anat ; 221: 179-185, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30393181

RESUMO

The practice of human and veterinary medicine is based on the science of anatomy and dissection courses are still irreplaceable in the teaching of anatomy. Embalming is required to preserve body donors, for which process formaldehyde (FA) is the most frequently used and well characterized biocidal substance. Since January 2016, a new occupational exposure limit (OEL) for FA of 0.37mg/m3 issued by the European Committee on Hazardous Substances is obligatory since FA has been classified as a human 1B carcinogen. The anatomical institutes in the German-speaking region are called upon to consolidate efforts to reduce use of FA in anatomical curricula and body donations. As a result, the Anatomische Gesellschaft (AG) has formed a "Working Group for Reduction of Formaldehyde Exposure in Dissection Courses" tasked with discussion and recommendation of measures to reduce FA. Based on the assessment of the Working Group, the AG has issued an official opinion to the effect that, at this point in time, embalming of body donors without FA completely is not feasible. Therefore, a combination of approaches are to be used to reduce FA exposure, including technical and structural (architectural) adaptations, modification of protocols for fixation and preservation as well as organizational measures. One structural measure considered unavoidable is the integration of air supply and exhaust of individual dissecting tables into the ventilation system of the anatomy building. To embalm human body donors, intra-arterial perfusion fixation with up to 4% FA and a total fluid volume of 150mL/kg body weight will suffice. For animals where body weights and biology of bodies vary widely (i.e. special needs of fixation for ruminants, large animals as horses) perfusion fixation with up to 4% FA and a quantity of fixative solution of 10-15% of the body weight may be required. Preservation of body donors in storage (immersion) can be done with 40% ethanol or in a full bath preservation containing up to 2% FA. Corpse humidification in the dissecting room is possible with 2% phenoxyethanol, in each case without FA. In veterinary anatomy, microbiological burden is often higher and therefore might lead to a need of FA in long-time storage. Compliance with the current OEL in all institutes would appear to be feasible in combination with various organizational measures.


Assuntos
Anatomia/educação , Formaldeído/efeitos adversos , Exposição Ocupacional/prevenção & controle , Hipersensibilidade Respiratória/prevenção & controle , Humanos , Guias de Prática Clínica como Assunto
6.
Knee Surg Sports Traumatol Arthrosc ; 26(1): 146-151, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28624856

RESUMO

PURPOSE: A detailed structural anatomy of the posterosuperior shoulder capsule and "glenocapsular ligament" is still rather unknown. The purpose of this study was meticulously to investigate and describe the structure and blood supply of the glenocapsular ligament on the posterosuperior shoulder joint capsule. METHOD: Sixteen fixed and twelve fresh cadaveric shoulder specimens with a mean age of 73.4 (±6.4) years were analysed. Dissection without arterial injection was performed on the 16 fixed specimens-using an alcohol-formalin-glycerol solution. Before dissection, the 12 fresh specimens received of arterial injection a 10% aqueous dispersion of latex solution. After the injection, these shoulders were also fixed in an alcohol-formalin-glycerol solution. RESULTS: The glenocapsular ligament was found in all 28 specimens. Single or double parallel-running bundles of connective tissue fibres were found to form a capsular-ligamentous structure on the posterosuperior part of the joint capsule. One part of the ligament was mediosuperior, another posterosuperior. The mediosuperior part varied in shape, and in 12 of 28 cases, it was absent. The glenocapsular ligament arose from the supraglenoid tubercle and posterior part of the collum scapulae and inserted into the semicircular humeral ligament. The posterior ascending branch of the circumflex scapular artery directly fed small branches laterally and medially to the joint capsule, supplying the glenocapsular ligament and the deep layer of the joint capsule. CONCLUSION: The glenocapsular ligament is a constant anatomical structure that consists of one or two different parts. The glenocapsular ligament and the posterosuperior part of the joint capsule appear well vascularized via the posterior ascending branch of the circumflex scapular artery. CLINICAL RELEVANCE: It is the hope of the authors that this anatomical study can help surgeons who perform open or arthroscopic surgery to the posterior part of the shoulder. Knowledge of the vascular anatomy presented in this study may be especially important when incisions are made to the posterior part of the shoulder, and should minimize the risk of complications.


Assuntos
Cápsula Articular/irrigação sanguínea , Ligamentos Articulares/irrigação sanguínea , Escápula/irrigação sanguínea , Articulação do Ombro/irrigação sanguínea , Idoso , Cadáver , Feminino , Humanos , Cápsula Articular/anatomia & histologia , Ligamentos Articulares/anatomia & histologia , Masculino , Escápula/anatomia & histologia , Articulação do Ombro/anatomia & histologia
7.
Plast Reconstr Surg ; 139(5): 1075-1082, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28092335

RESUMO

BACKGROUND: Understanding the precise position and course of the superior and inferior labial arteries within the upper lip and the lower lip is crucial for safe and complication-free applications of volumizing materials. METHODS: One hundred ninety-three anatomical head specimens (56.5 percent female cadavers) of Caucasian ethnicity were investigated in this large multicenter anatomical study. In total, six 3-cm-long vertical incisions were performed on each lip (midline and 1 cm medial to the angles of the mouth) to identify the position of the superior and inferior labial arteries in relation to the orbicularis oris muscle. RESULTS: Three different positions of the superior and inferior labial arteries were identified: submucosal (i.e., between the oral mucosa and the orbicularis oris muscle in 78.1 percent of the cases), intramuscular (i.e., between the superficial and deep layers of the orbicularis oris muscle in 17.5 percent of the cases), and subcutaneous (i.e., between the skin and the orbicularis oris muscle in 2.1 percent of the cases). The variability in changing the respective position along the labial course was 29 percent for the total upper and 32 percent for the total lower lip. The midline location was identified in both the upper and lower lips to be the most variable. CONCLUSIONS: Based on the results of this investigation, a safer location for the application of volumizing material is the subcutaneous plane in the paramedian location of both the upper lip and the lower lip. Care has to be taken when aiming to inject in the midline, as the artery can be identified more frequently in superficial positions.


Assuntos
Cadáver , Lábio/irrigação sanguínea , Angiografia , Artérias , Técnicas Cosméticas , Preenchedores Dérmicos/administração & dosagem , Feminino , Humanos , Masculino , Tomografia Computadorizada por Raios X
8.
Knee Surg Sports Traumatol Arthrosc ; 25(8): 2502-2510, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26820966

RESUMO

PURPOSE: To evaluate the knee kinematics of the intact, MPFL-ruptured and MPFL-reconstructed knee and, moreover, to compare dynamic patellofemoral contact pressure of the gracilis tendon and the fascia lata as an alternative graft option for reconstruction of the MPFL. METHODS: Eight paired human cadaveric knees were fixed in a custom-made fixation device. Patellofemoral contact pressure was assessed during a dynamic flexion movement at 15°-30°-45°-60°-75° and 90° using a pressure-sensitive film (Tekscan). The medial patellofemoral ligament was cut, and measurements were repeated. Finally, reconstruction of the MPFL was performed using the gracilis tendon (group I) or a fascia lata graft (group II). Tunnel localization was performed under fluoroscopic control. Grafts were fixed at 30° of flexion, and pressure measurements were repeated. RESULTS: Incision of the medial patellofemoral ligament significantly reduced patellofemoral contact pressure at 15°, 30° and 45° of knee flexion compared to the intact knee (p < 0.05), whereas reconstruction of the MPFL using either gracilis tendon of the fascia lata was able to restore pressure distributions at 15° and 30° of knee flexion. However, in the hamstring group, reconstruction of the MPFL revealed a significantly reduced contact pressure at 45° of flexion (p = 0.038) compared to the intact knee. In the fascia lata group, a significant reduction in patellofemoral contact pressure was observed after MPFL reconstruction at 45°, 60°, 75° and 90° of knee flexion (p < 0.05). CONCLUSIONS: Anatomic reconstruction of the MPFL with either a gracilis or a fascia lata graft showed comparable patellofemoral pressure distributions which were closely restored compared to the native knee. Therefore, the fascia lata has shown to be a viable alternative to the gracilis tendon for reconstruction of the MPFL. However, anatomic reconstruction of the MPFL may lead to persistently altered patellofemoral contact pressure during knee flexion compared to the native knee independent of the tested graft.


Assuntos
Fascia Lata/transplante , Músculo Grácil/cirurgia , Ligamentos Articulares/cirurgia , Articulação Patelofemoral/cirurgia , Pressão , Amplitude de Movimento Articular , Tendões/transplante , Fenômenos Biomecânicos , Cadáver , Fluoroscopia , Músculos Isquiossurais , Humanos , Articulação do Joelho/fisiopatologia , Articulação do Joelho/cirurgia , Ligamentos Articulares/fisiopatologia , Articulação Patelofemoral/fisiopatologia , Procedimentos de Cirurgia Plástica
9.
Knee Surg Sports Traumatol Arthrosc ; 25(7): 2041-2046, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27872990

RESUMO

PURPOSE: Vascularity of the subacromial bursa and rotator cuff tendons is key factors in the pathogenesis of subacromial bursitis and impingement syndrome, rotator cuff tendinitis, and rotator cuff tears. The purpose of this study was to investigate and describe blood supply to the cranial and caudal parts of the subacromial bursa and the vascularity of the rotator cuff tendons on the bursal side. METHODS: Fourteen fresh cadaveric shoulders from six females and eight males with a mean age of 71.7 (±10.8) years were studied. Before dissection, an arterial injection of 10% aqueous dispersion of latex was administered. Post-injection, the shoulders were fixed in an alcohol-formalin-glycerol solution. RESULTS: The cranial and caudal bursa of all specimens was mainly supplied by the thoracoacromial, suprascapular, and anterior and posterior circumflex humeral arteries. The cranial part of the bursa was supplied anteriorly by the thoracoacromial artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third. The caudal part received arterial blood anteriorly from the anterior circumflex humeral artery, and posteriorly and medially by the posterior circumflex humeral artery as far as the medial third of the caudal bursa. In addition, the suprascapular artery branched at the upper surface of the coracohumeral ligament, and the subcoracoid artery branched at the under surface of the same ligament. CONCLUSION: The subacromial bursa appears well vascularized. The results of the present investigation showed that blood supply to the subacromial bursa at the caudal part and rotator cuff tendons on the bursal side was linked to the same arteries. The subcoracoid artery supplied interval rotator structures close to the caudal bursa. It is the wish of the authors that this meticulous anatomical work will help surgeons in their day-to-day clinical work, e.g. to minimize the risk of complications such as perioperative bleeding.


Assuntos
Bolsa Sinovial/irrigação sanguínea , Manguito Rotador/irrigação sanguínea , Idoso , Cadáver , Feminino , Humanos , Masculino , Articulação do Ombro/irrigação sanguínea
10.
Mol Metab ; 5(4): 283-295, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27069868

RESUMO

OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and is associated with an enhanced risk for liver and cardiovascular diseases and mortality. NAFLD can progress from simple hepatic steatosis to non-alcoholic steatohepatitis (NASH). However, the mechanisms predisposing to this progression remain undefined. Notably, hepatic mitochondrial dysfunction is a common finding in patients with NASH. Due to a lack of appropriate experimental animal models, it has not been evaluated whether this mitochondrial dysfunction plays a causative role for the development of NASH. METHODS: To determine the effect of a well-defined mitochondrial dysfunction on liver physiology at baseline and during dietary challenge, C57BL/6J-mt(FVB/N) mice were employed. This conplastic inbred strain has been previously reported to exhibit decreased mitochondrial respiration likely linked to a non-synonymous gene variation (nt7778 G/T) of the mitochondrial ATP synthase protein 8 (mt-ATP8). RESULTS: At baseline conditions, C57BL/6J-mt(FVB/N) mice displayed hepatic mitochondrial dysfunction characterized by decreased ATP production and increased formation of reactive oxygen species (ROS). Moreover, genes affecting lipid metabolism were differentially expressed, hepatic triglyceride and cholesterol levels were changed in these animals, and various acyl-carnitines were altered, pointing towards an impaired mitochondrial carnitine shuttle. However, over a period of twelve months, no spontaneous hepatic steatosis or inflammation was observed. On the other hand, upon dietary challenge with either a methionine and choline deficient diet or a western-style diet, C57BL/6J-mt(FVB/N) mice developed aggravated steatohepatitis as characterized by lipid accumulation, ballooning of hepatocytes and infiltration of immune cells. CONCLUSIONS: We observed distinct metabolic alterations in mice with a mitochondrial polymorphism associated hepatic mitochondrial dysfunction. However, a second hit, such as dietary stress, was required to cause hepatic steatosis and inflammation. This study suggests a causative role of hepatic mitochondrial dysfunction in the development of experimental NASH.

11.
Knee Surg Sports Traumatol Arthrosc ; 23(9): 2734-41, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24850240

RESUMO

PURPOSE: To evaluate knee laxity after anatomic ACL reconstruction with additional suture repair of a medial meniscus tear. METHODS: Kinematics of the intact knee were determined in 12 human cadaver specimens in response to a 134-N anterior tibial load (aTT) and a combined rotatory load of 10 Nm valgus and 4 Nm internal tibial rotation (aTTPS) using a robotic/universal force moment sensor testing system. Subsequently, the ACL was resected following the creation of a standardized tear of the medial meniscus, a standard meniscus repair and an ACL reconstruction using an anatomic single-bundle (6) or an anatomic double-bundle technique (6). Knee kinematics were determined following every sub-step. RESULTS: Significant increase of aTT in the ACL-deficient knee was found (p ≤ 0.001) with a further increase in the ACL-deficient knee with additional medial meniscal rupture (p ≤ 0.001). ACL reconstructions significantly decreased aTT compared with the ACL and meniscus-ruptured knee. No significant differences were seen between the intact knee and the ACL-reconstructed knee with additional meniscal repair (p < 0.05). In response to a simulated pivot shift, aTTPS in the intact knee significantly increased in the ACL-deficient knee and meniscus-ruptured knee (p = 0.005). No significant differences in knee kinematics were found between SB as well as DB ACL reconstruction with additional medial meniscal repair compared with the intact knee. Comparison of SB versus DB ACL reconstruction did not reveal any significant differences in a simulated Lachman test or simulated pivot shift test (n.s.). CONCLUSIONS: aTT as well as aTTPS significantly increased with ACL deficiency compared with the intact knee; additional medial meniscal rupture further increased aTT. Anatomic ACL reconstruction with medial meniscal repair did not reveal significant differences in knee kinematics compared with the intact knee. Comparison of anatomic SB versus DB ACL reconstruction with additional repair of the medial meniscus did not show significant differences neither in a simulated Lachman nor in a simulated pivot shift test.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior/métodos , Instabilidade Articular/cirurgia , Traumatismos do Joelho/fisiopatologia , Articulação do Joelho/fisiopatologia , Meniscos Tibiais/cirurgia , Idoso , Ligamento Cruzado Anterior/fisiopatologia , Ligamento Cruzado Anterior/cirurgia , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Instabilidade Articular/etiologia , Instabilidade Articular/fisiopatologia , Traumatismos do Joelho/complicações , Traumatismos do Joelho/cirurgia , Articulação do Joelho/cirurgia , Masculino , Meniscos Tibiais/fisiopatologia , Robótica , Lesões do Menisco Tibial
12.
Int Orthop ; 39(4): 681-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25398470

RESUMO

PURPOSE: The purpose of this study was the evaluation of knee laxity in the ACL-deficient knee with combined meniscal tear, meniscal suture and partial medial meniscectomy. METHODS: Kinematics of the intact knee were determined in 18 human cadaver specimens in response to a 134-N anterior tibial load (aTT) as well as a combined rotatory load of 10 Nm valgus and 4 Nm internal tibial rotation using a robotic/universal force moment sensor testing system. The anterior cruciate ligament was resected. Subsequently, a vertical bucket-handle medial meniscal tear was created followed by a standard meniscus repair using horizontal inside-out stitches or a partial medial meniscectomy. Knee kinematics were calculated following every sub-step. RESULTS: A significant increase of anterior tibial translation was found in the ACL-deficient knee compared to the intact knee at 30° and 90° of flexion (p = 0.001; p ≤ 0.001). Additional tear of the medial meniscus significantly increased anterior tibial translation (p = 0.01). In response to a simulated pivot shift, anterior tibial translation of the intact knee did not increase significantly after ACL resection (p = 0.067). However, ACL deficiency with an additional medial meniscus tear led to a significant increase compared to the intact knee at 0° of flexion (p = 0.009). CONCLUSIONS: Additional injury of the medial meniscus increased aTT as well as aTT under a combined rotatory load in the ACL-deficient knee whereas repair of the meniscus significantly decreased aTT. Therefore, the meniscus status does have a significant impact on knee kinematics in the ACL-deficient knee. The present biomechanical study further highlights the importance of preserving the meniscus especially in patients with additional ACL injuries.


Assuntos
Lesões do Ligamento Cruzado Anterior , Instabilidade Articular/fisiopatologia , Traumatismos do Joelho/fisiopatologia , Articulação do Joelho/fisiopatologia , Amplitude de Movimento Articular/fisiologia , Robótica/métodos , Tíbia/cirurgia , Lesões do Menisco Tibial , Adulto , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Articulação do Joelho/cirurgia , Masculino , Meniscos Tibiais/cirurgia , Ruptura , Torque
13.
Med Phys ; 39(11): 7042-54, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23127095

RESUMO

PURPOSE: In computed tomography imaging metal objects in the region of interest introduce inconsistencies during data acquisition. Reconstructing these data leads to an image in spatial domain including star-shaped or stripe-like artifacts. In order to enhance the quality of the resulting image the influence of the metal objects can be reduced. Here, a metal artifact reduction (MAR) approach is proposed that is based on a recomputation of the inconsistent projection data using a fully three-dimensional Fourier-based interpolation. The success of the projection space restoration depends sensitively on a sensible continuation of neighboring structures into the recomputed area. Fortunately, structural information of the entire data is inherently included in the Fourier space of the data. This can be used for a reasonable recomputation of the inconsistent projection data. METHODS: The key step of the proposed MAR strategy is the recomputation of the inconsistent projection data based on an interpolation using nonequispaced fast Fourier transforms (NFFT). The NFFT interpolation can be applied in arbitrary dimension. The approach overcomes the problem of adequate neighborhood definitions on irregular grids, since this is inherently given through the usage of higher dimensional Fourier transforms. Here, applications up to the third interpolation dimension are presented and validated. Furthermore, prior knowledge may be included by an appropriate damping of the transform during the interpolation step. This MAR method is applicable on each angular view of a detector row, on two-dimensional projection data as well as on three-dimensional projection data, e.g., a set of sequential acquisitions at different spatial positions, projection data of a spiral acquisition, or cone-beam projection data. RESULTS: Results of the novel MAR scheme based on one-, two-, and three-dimensional NFFT interpolations are presented. All results are compared in projection data space and spatial domain with the well-known one-dimensional linear interpolation strategy. CONCLUSIONS: In conclusion, it is recommended to include as much spatial information into the recomputation step as possible. This is realized by increasing the dimension of the NFFT. The resulting image quality can be enhanced considerably.


Assuntos
Artefatos , Imageamento Tridimensional/métodos , Metais , Tomografia Computadorizada por Raios X/métodos , Análise de Fourier , Humanos , Imagens de Fantasmas
14.
Am J Dermatopathol ; 25(6): 451-62, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14631185

RESUMO

Erythema annulare centrifugum is classified generally into a superficial and a deep type. Whether those types are variants of the same process or unrelated to one another, and whether they represent non-specific patterns or specific clinico-pathologic entities, is controversial. To answer those questions, we analyzed 82 biopsy specimens from 73 patients with a clinical and histopathologic diagnosis of erythema annulare centrifugum, gyrate erythema, or figurate erythema regarding a variety of clinical and histopathologic findings. We found substantial differences between cases with a wholly superficial type and cases with a superficial and deep infiltrate. Clinically, a collarette of scales was seen only in the superficial type. Histopathologically, some findings were much more common in the superficial type (eg, spongiosis, parakeratosis, crusts, edema of the papillary dermis, epidermal hyperplasia) and others in the deep type (eg, sleeve-like arrangement of the infiltrate, melanophages, subtle vacuolar changes at the dermo-epidermal junction, individual necrotic keratinocytes). Whereas cases of the superficial type could be distinguished from differential diagnoses by a variety of clinical and histopathologic findings, most cases of the deep type showed subtle signs of lupus erythematosus. Neither type was associated consistently with any other systemic disease. Because the superficial and the deep type of erythema annulare centrifugum seem to be unrelated to one another, they should not be referred to by the same name. We believe that the term should be reserved for the superficial type because the latter seems to be a specific clinico-pathologic entity. By contrast, most cases of the deep type seem to be annular examples of tumid lupus erythematosus and should be diagnosed that way. If findings militate against the diagnosis of lupus erythematosus, we suggest using a descriptive term that signals non-specificity-namely, deep figurate erythema.


Assuntos
Eritema/patologia , Adolescente , Adulto , Idoso , Diagnóstico Diferencial , Eritema/classificação , Eritema/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pele/patologia
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