The focus of this research was to design a functional and user-friendly reacher for people with spinal cord injuries (SCIs). Engineering advancements have taken assistive robotics to new dimensions. Technologies such as wheelchair robotics and myo-electronically controlled systems have opened up a wide range of new applications to assist people with physical disabilities.
View Article and Find Full Text PDFA 39-year-old woman with Carney complex presented with a stroke of undetermined etiology. Computed tomography showed bilateral thalamic infarctions and also an unsuspected multicompartmental cystic neoplasm that had eroded the anterior clivus and extended forward into the nasopharynx. Histologically, the mass appeared benign and was composed of spindle cells and multiple foci of striated muscle.
View Article and Find Full Text PDFMalignant peripheral nerve sheath tumors are usually Schwann cell derived. Differentiation along mesenchymal lines is uncommon. Herein we present an example with smooth muscle differentiation occurring in the left distal forearm of a 62-year-old male with neurofibromatosis type I.
View Article and Find Full Text PDFClear cell change in basal cell carcinomas is a well-recognized phenomenon, but is obviously rare in trichoblastomas. We present two cases of clear cell trichoblastoma in which clear cell change was very much prominent, and the results of an ultrastructural study intended to explore the basis of that feature. Both our patients were women, aged 56 and 77 years, who presented with solitary, slowly growing nodules that measured 3 to 5 cm in largest dimension and were located on the scalp and the flexor aspect of the lower arm.
View Article and Find Full Text PDFHepatic amyloid deposition in the form of globular inclusions is a rare occurrence. Only 24 such cases have been reported to date. Its clinical and pathological significance are undefined.
View Article and Find Full Text PDFMesothelioma with a pronounced myxoid stroma has been identified as a morphological pattern that might portend a better prognosis. Reports on this type of cases are few. Its clinical and pathological features are not defined.
View Article and Find Full Text PDFHepatobiliary neuroendocrine carcinoma was diagnosed in 17 cats in a period of 10 years. Seven tumors were of intrahepatic origin, one of which was a composite containing components of epithelial and neuroendocrine carcinoma. Nine tumors were of extrahepatic origin, and one tumor was located in the gall-bladder.
View Article and Find Full Text PDFThe term malignant fibrous histiocytoma was coined by Stout and associates in the 1960s to encompass pleomorphic soft tissue sarcomas presumably derived from histiocytes that are capable of fibroblastic transformation. The concept was reaffirmed in the following 2 decades and malignant fibrous histiocytoma thus was regarded as the most common soft tissue tumor in older adults. However, recent more critical clinicopathologic, ultrastructural, and immunohistochemical studies have shown that malignant fibrous histiocytomas are not derived from histiocytic "facultative fibroblasts" and many neoplasms so diagnosed actually are pleomorphic subtypes of other sarcomas.
View Article and Find Full Text PDFTen dogs with neuroendocrine carcinoma of the liver were selected for inclusion in the study. Clinical signs were anorexia (7), vomiting (5), polydipsia/polyuria (3), icterus (2), lethargy (2), weight loss (2), paresis (1), ataxia (1), weakness (1), collapse (1), and urinary tract infection (1). Hematologic and biochemical abnormalities included anemia (2/8), leukocytosis (4/8), high liver enzyme activity (serum alkaline phosphatase, 7/9; alanine transaminase, 7/9; aspartate transaminase, 8/9), and high total bilirubin (6/9).
View Article and Find Full Text PDFLymphohistiocytoid mesothelioma (LHM) is a term proposed to designate a variant of mesothelioma that assumes a histiocytoid morphology and contains intense lymphocytic infiltrates. Reports on this variant are few, and its clinicopathologic and ultrastructural characteristics are still to be defined. The authors have studied 4 such cases that were identified among 120 mesotheliomas in the electron microscopy (EM) files of a single institution between 1982 and 2002.
View Article and Find Full Text PDFUnlike most soft tissue tumors, schwannoma is characterized by the presence of distinct linear, frequently duplicated external lamina (EL). Although electron microscopy remains the gold standard for demonstrating this unique feature and distinguishing its morphologic variants from mimickers, the use of two anti-EL antibodies, laminin and type IV collagen, appears to supersede electron microscopy in terms of current practice. To determine whether immunohistochemical expression correlates with ultrastructural findings, 10 cellular schwannomas, 18 classic schwannomas, and 3 melanotic schwannomas were evaluated ultrastructurally and immunohistochemically using antibodies to type IV collagen and laminin.
View Article and Find Full Text PDFSince 1980 when Sibley and coworkers first described a nodal neoplasm of unknown histogenesis with striking surface microvilli for which they introduced the term "anemone cell," a series of reports have appeared in the literature illustrating tumors with similar ultrastructural features. While most reported cases showed differentiation along a particular line, rare cases remained histogenetically unclear. In this report a case is described of epithelioid gastric gastrointestinal stromal tumor metastatic to the liver, showing conspicuous long microvillus-type cell processes partially or circumferentially coating the cell surfaces, thus qualifying as yet another tumor type with anemone cell features.
View Article and Find Full Text PDFCystic thymoma was diagnosed in 14 cats in a period of 6 years. The most common clinical sign was laboured breathing. The tumours were characterized by various-sized cystic spaces with central vessels.
View Article and Find Full Text PDFDeciduoid mesothelioma was first described in young females and in the peritoneum, which led to the suggestion that deciduoid mesothelioma was a distinct subtype with specific clinical and pathologic features. Later reports, however, have shown that this type of mesothelioma may also occur in elderly people and in the pleura. Cases reported in the literature so far are limited, and the disease is not well defined.
View Article and Find Full Text PDFNeuroendocrine carcinoma of the nasopharynx was diagnosed in a 9-year-old male Golden Retriever. The mass was identified by computed tomography of the nasal cavity and nasopharyngoscopy, and it was surgically excised. Histologic, cytochemical, and electromicroscopic examination of specimens confirmed the type of tumor.
View Article and Find Full Text PDFPigs with hypertrophic cardiomyopathy diagnosed by echocardiographic examination were selected for study from a genetic breeding herd. Under dissecting microscopic examination, intramural coronary arteries in the septum and left ventricular free wall of euthanized pigs were collected for ultrastructural study. The major lesions of wall thickening included degeneration or denudation of endothelium, subendothelial edema, proliferation of collagen fiber, and hyperplasia of smooth muscle cells.
View Article and Find Full Text PDFMalignant neuroendocrine carcinoma of the skin (Merkel cell tumor) was diagnosed in an 18-year-old spayed female Maine Coon Cat. The diagnosis was made on the basis of morphologic and electron microscopic findings. The cat was euthanatized 321 days after surgical excision of the tumor.
View Article and Find Full Text PDFUltrastruct Pathol
June 2001
Because the fibroblast has a remarkable capability of phenotypic modulations, reflected in both morphologic and immunohistochemical (IHC) changes, ultrastructural studies are mandatory to identify the variants of fibroblasts. Myofibroblasts or histiofibroblasts are such examples, demonstrating chimeric ultrastructural features of fibroblastic cells in common with smooth muscle cells or with histiocytes, respectively. The presence of epithelioid fibroblastic cells sharing morphologic features with epithelial or plasma cells has not been yet characterized.
View Article and Find Full Text PDFThe abundant glands situated in the lamina propria of the human anterior middle nasal turbinate were complex tubules that consist of serous, seromucous, and mucous cells, either singly or in combination. Serous granules were homogeneously dense, but could have a small lighter core. Seromucous granules had a dense rim and a large compartment of appreciably lighter density.
View Article and Find Full Text PDFAs primary bone fibrosarcoma (FS) and malignant fibrous histiocytoma (MFH) have similar clinical, radiographic, or survival manifestations, ultrastructural and immunohistochemical studies were undertaken to determine the differentiation pathways of constituent malignant cells. Twelve cases of primary intraosseous FS and MFH were selected for this ultrastructural comparative study and were analyzed for fibroblastic or modified fibroblastic differentiation. There were 4 FS cases and 8 MFH cases, of which 5 were storiform-pleomorphic, 2 were giant cell, and 1 was myxoid type.
View Article and Find Full Text PDFCytokeratin-positive interstitial reticulum cells (CIRCs) have been described as a subset of fibroblastic reticulum cells (FBRCs) normally found in lymph nodes, the spleen, and tonsils. Although tumors derived form other reticulum (dendritic) cells, specifically follicular dendritic cells, interdigitating dendritic cells, and cytokeratin-negative FBRCs, have been well documented and are now accepted, this is not the case for tumors of CIRCs. A possible reason for this failure is the difficulty in distinguishing them from other tumors, particularly carcinoma.
View Article and Find Full Text PDFUnusual or atypical melanocytic nevi can be confused with malignant melanoma. The authors present two cases of an unusual variant of blue nevus that were misdiagnosed initially as malignancy. Both lesions were asymptomatic and characterized clinically by childhood onset, with slow enlargement during adolescence and subsequent nodule formation.
View Article and Find Full Text PDF"Hyalinizing spindle cell tumor with giant rosettes" is a tumor recently described by Lane et al. and thought by them possibly to represent a form of low-grade fibromyxoid sarcoma. Proof of a metastatic potential was lacking.
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