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AJR. American Journal of Roentgenology Aug 1984One hundred seven women 18-65 years old were studied who were referred for suspected central nervous system disease not related to the pituitary gland or hypothalamus....
One hundred seven women 18-65 years old were studied who were referred for suspected central nervous system disease not related to the pituitary gland or hypothalamus. High-resolution, direct, coronal, contrast-enhanced computed tomography (CT) was used to examine the size, shape, and density of the normal pituitary gland. There were three major conclusions: (1) the height of the normal gland can be as much as 9 mm; (2) the superior margin of the gland may bulge in normal patients; and (3) both large size and convex contour appear to be associated with younger age. It was also found that serum prolactin levels do not appear to correlate with the CT appearances. Both low- and high-density areas were seen within the gland, and may be due to either tumors, cysts, infarcts, or metastases. Noise artifacts inherent in high-detail, thin-section, soft-tissue scanning may be a limiting factor in defining reproducible patterns in different parts of the normal pituitary gland.
Topics: Adolescent; Adult; Aged; Aging; Female; Humans; Middle Aged; Pituitary Gland; Prolactin; Reference Values; Sella Turcica; Tomography, X-Ray Computed
PubMed: 6611072
DOI: 10.2214/ajr.143.2.377 -
Topics in Magnetic Resonance Imaging :... Oct 2000Despite a traditional perception of reliance on computed tomography and lack of acceptance of magnetic resonance imaging (MRI) for detecting acute hemorrhage, MRI... (Review)
Review
Despite a traditional perception of reliance on computed tomography and lack of acceptance of magnetic resonance imaging (MRI) for detecting acute hemorrhage, MRI appears to be used increasingly in hemorrhagic stroke. This review addresses the MRI findings of acute hemorrhagic stroke obtained using relatively new imaging techniques. These new techniques have resulted in more acute stroke patients undergoing MRI examination. New information about the frequency and appearance of hemorrhage is emerging: for example, approximately 15-26% of cases of acute cerebral infarctions appear to be complicated by intracerebral hemorrhage. The MRI appearances of hemorrhagic transformation of ischemic infarction, as well as acute hypertensive intracerebral hemorrhage, are discussed based on clinical, biochemical, and technical aspects.
Topics: Brain Ischemia; Cerebral Hemorrhage; Humans; Magnetic Resonance Imaging; Stroke
PubMed: 11142627
DOI: 10.1097/00002142-200010000-00005 -
Molecular and Cellular Endocrinology Sep 2007During the last larval molt in Manduca sexta, in response to an increasing, then decreasing ecdysteroid titer, a number of transcription factors such as E75B, MHR3,...
During the last larval molt in Manduca sexta, in response to an increasing, then decreasing ecdysteroid titer, a number of transcription factors such as E75B, MHR3, MHR4, and betaFTZ-F1 appear and disappear in the abdominal epidermis leading to dopa decarboxylase (DDC) expression. Messenger RNAs for both the 20E-induced transcription factors, MHR3 and E75B, are maximal near the peak of the ecdysteroid titer with MHR4 mRNA appearing as the titer declines followed by betaFTZ-F1 and DDC mRNAs. E75B and MHR4 mRNA were not expressed in Manduca GV1 cells, either during exposure to 20E or after its removal. When either MHR3 dsRNA was transfected or E75B was constitutively expressed in these cells, MHR4 mRNA appeared in response to 20E by 6h. E75B was found to form a heterodimer with MHR3 using the BacterioMatch II two-hybrid assay. We conclude that MHR3 apparently suppresses MHR4 expression in the presence of 20E; the appearance of E75B then removes MHR3 by dimerization, allowing MHR4 to be expressed. Because of significant basal activity of the ddc promoter in the GV1 cells, we could perform rescue experiments by adding various factors. Constitutive expression of either E75B or MHR4 in the cells suppressed the significant basal activity of the 3.2kb ddc promoter in the GV1 cells, but 20E had no effect on this activity. Thus, E75B and MHR4 are 20E-induced inhibitory factors that suppress ddc expression and therefore act as ecdysteroid-regulated timers to coordinate the onset of ddc expression at the end of the molt.
Topics: Animals; Cell Line; Dopa Decarboxylase; Ecdysteroids; Gene Expression Regulation, Developmental; Insect Proteins; Manduca; Models, Biological; Molting; Promoter Regions, Genetic; Protein Binding; Receptors, Cytoplasmic and Nuclear
PubMed: 17706862
DOI: 10.1016/j.mce.2007.07.002 -
Nuclear Medicine Communications Mar 1984The standard nuclear medicine textbooks describe the pyramidal lobe of the thyroid as arising from the upper part of the thyroid lobes. Anatomy and surgical texts...
The standard nuclear medicine textbooks describe the pyramidal lobe of the thyroid as arising from the upper part of the thyroid lobes. Anatomy and surgical texts however describe it as a thyroglossal tract remnant and state that it arises from the isthmus. Review of 150 thyroid scintigrams confirms that on scintigraphy the pyramidal lobe does appear to originate from the upper pole. We have used single photon emission tomography to demonstrate the true origin of the pyramidal lobe by removing overlying thyroid tissue. We suggest that the pyramidal lobe arises from the isthmus and the appearances on scintigraphy are due to the lower part of the lobe being obscured behind the main thyroid lobe.
Topics: Humans; Retrospective Studies; Sodium Pertechnetate Tc 99m; Thyroid Gland; Tomography, Emission-Computed
PubMed: 6099530
DOI: 10.1097/00006231-198403000-00006 -
The Journal of Biological Chemistry Aug 1983We have measured the movement of newly synthesized phosphatidylethanolamine (PE) molecules from sites of intracellular synthesis to the plasma membrane in cultured V79...
We have measured the movement of newly synthesized phosphatidylethanolamine (PE) molecules from sites of intracellular synthesis to the plasma membrane in cultured V79 Chinese hamster fibroblasts. Plasma membrane PE was distinguished from intracellular PE by its derivatization with an amino-reactive reagent, trinitrobenzene sulfonic acid, under nonpermeating conditions. Within minutes after the addition of radiolabeled precursors of PE to the culture medium, radiolabeled PE appeared at the plasma membrane. The fraction of radiolabeled PE molecules appearing at the plasma membrane increased rapidly over a 2-h period and then increased very slowly for several days to a constant specific radioactivity. By measuring the release of radiolabeled secretory proteins, we determined that the transport of newly synthesized proteins to the cell surface occurred more slowly than the transport of PE. Preincubation of cells with either cytochalasin B, cytochalasin D, colchicine, oncobendazole, sodium azide, 2-deoxyglucose, dinitrophenol, p-trifluoromethoxyphenylhydrazone, or monensin did not block the transport of de novo synthesized PE; however, incubation of cells in culture medium at 2 degrees C effectively halted the appearance of new PE molecules at the plasma membrane. When cells which had been incubated at 2 degrees C were warmed, PE molecules from intracellular PE pools once again began to appear at the plasma membrane. These results suggest that the rapid transport of newly synthesized PE molecules to the plasma membrane occurs by a mechanism independent of that used for the transport of newly synthesized proteins.
Topics: Animals; Cell Line; Cell Membrane; Cricetinae; Cricetulus; Fibroblasts; Fluorescent Antibody Technique; Lung; Phosphatidylethanolamines; Time Factors; Trinitrobenzenesulfonic Acid
PubMed: 6348038
DOI: No ID Found -
Acta Radiologica (Stockholm, Sweden :... Sep 1993To provide a detailed description of the MR appearances of central neurocytoma, MR images of 13 patients with central neurocytoma were retrospectively reviewed and... (Comparative Study)
Comparative Study
To provide a detailed description of the MR appearances of central neurocytoma, MR images of 13 patients with central neurocytoma were retrospectively reviewed and compared with CT examinations. The histology was confirmed by ultrastructural and immunohistochemical studies. In 12 patients the tumors were histologically benign and located in the anterior part of the lateral ventricle, 6 of which extended to the 3rd ventricle. There was one case of a histologically malignant variant involving the thalamus and lateral ventricle. The tumors were primarily solid, but contained cysts (85%, 11/13), calcifications (69%, 9/13), and signal void from tumor vessels (62%, 8/13), frequently producing heterogeneous signal intensity on both T1- and T2-weighted images. Most of the solid portion appeared isointense or slightly hyperintense relative to the cerebral cortex on all MR pulse sequences. Calcifications were iso- or hypointense on MR, making them difficult to characterize with MR alone. Intratumoral hemorrhage was seen in 2 patients on MR but not on CT. Contrast enhancement was variable in degree and pattern. Coronal and sagittal MR images were valuable in evaluating the tumor extent and origin site, and in planning the surgical approach. It is concluded that MR imaging appears to be more useful than CT in the overall evaluation of central neurocytoma, even though calcification is better characterized with CT.
Topics: Adult; Brain Neoplasms; Cerebral Ventricle Neoplasms; Female; Humans; Magnetic Resonance Imaging; Male; Neuroblastoma; Retrospective Studies; Tomography, X-Ray Computed
PubMed: 8369193
DOI: No ID Found -
Israel Journal of Medical Sciences 1981A series of 27 cystosarcoma phyllodes diagnosed in 23 patients is presented. Treatment consisted of wide local excision with a rim of normal tissue for the...
A series of 27 cystosarcoma phyllodes diagnosed in 23 patients is presented. Treatment consisted of wide local excision with a rim of normal tissue for the histologically benign-appearing tumors, and simple mastectomy for the histologically malignant-appearing tumors. Of the three tumors with a malignant appearance, one metastasized distantly and the patient died; the other two patients were apparently cured. Of the 24 benign-appearing tumors, 3 recurred locally and were cured by reexcision. None behaved in a malignant fashion. There was one case of bilateral cystosarcoma phyllodes, and one tumor was associated with carcinoma of the breast. The local recurrence rate of 11% (3 out of 27) and mortality rate of 4% (1 out of 23) appears to justify this therapeutic approach. The precise indications for mastectomy in this disease are still unclear.
Topics: Adolescent; Adult; Aged; Breast Neoplasms; Female; Humans; Lymph Node Excision; Mastectomy; Middle Aged; Phyllodes Tumor
PubMed: 6273359
DOI: No ID Found -
Virchows Archiv : An International... 1994The distribution of integrin alpha 5 beta 1 (alpha 5 beta 1) and associated components during wound healing was investigated in the rat trachea following mechanical...
The distribution of integrin alpha 5 beta 1 (alpha 5 beta 1) and associated components during wound healing was investigated in the rat trachea following mechanical injury. Under anesthesia, the ventral surface of the trachea was scratched, and tissue specimens were obtained from 6 h to 3 weeks after injury and studied using light and electron microscopy and immunohistochemistry. alpha 5 beta 1, vinculin and actin in regenerating epithelial cells and extracellular fibronectin appear virtually simultaneously after injury (from 12 h to 7 days) as do alpha 5 beta 1, vinculin and alpha-smooth muscle actin in fibroblasts and cellular fibronectin in granulation tissue (from 3 to 10 days). Immunoelectron microscopy 2 days after injury showed that alpha 5 beta 1 and vinculin were localized on the basal and lateral surfaces of regenerating epithelial cells and fibroblast surfaces, and fibronectin was localized just under the regenerating epithelial cells, around collagen fibrils and sporadically around fibroblasts. Bromodeoxyuridine labeling showed that the appearance of these components was associated with the period of cell proliferation. The appearances of fibronectin, alpha 5 beta 1, vinculin and actin in regenerating epithelial cells and fibroblasts during tracheal wound healing are well coordinated. During the initial cell migration phase, plasma fibronectin may stimulate cell migration before cellular fibronectin is produced in situ, and regenerating epithelial cells appear to begin to migrate into the wound before cell proliferation starts.
Topics: Actins; Animals; Antibodies; Antibodies, Monoclonal; Biomarkers; Epithelium; Fibroblasts; Fibronectins; Immunohistochemistry; Integrins; Male; Microscopy, Immunoelectron; Rats; Rats, Wistar; Receptors, Fibronectin; Trachea; Vinculin; Wound Healing
PubMed: 7529621
DOI: 10.1007/BF00189581 -
Radiographics : a Review Publication of... 2013Esophageal neoplasms have a wide spectrum of clinical features, pathologic findings, and imaging manifestations. Leiomyomas are the most common benign esophageal... (Review)
Review
Esophageal neoplasms have a wide spectrum of clinical features, pathologic findings, and imaging manifestations. Leiomyomas are the most common benign esophageal neoplasm, typically appearing as smoothly marginated intramural masses. Fibrovascular polyps arise in the cervical esophagus, gradually elongating as they are pulled inferiorly by esophageal peristalsis. Granular cell tumors are generally incidental small intramural masses with an appearance similar to that of leiomyomas. Malignant esophageal neoplasms are a common cause of cancer mortality, particularly squamous cell carcinoma (SCC) and adenocarcinoma. Both of these tumors occur in older men, most often appearing as irregular infiltrative lesions at barium examination, with evidence of tumor spread beyond the esophagus at cross-sectional imaging. Adenocarcinoma arises from Barrett esophagus and is much more likely than SCC to involve the gastroesophageal junction. Esophageal involvement by lymphoma is usually secondary to tumor spread from the stomach or mediastinum. Spindle cell carcinoma is a biphasic malignancy with carcinomatous and sarcomatous elements that forms a bulky polypoid intraluminal mass. Neuroendocrine carcinoma is an aggressive neoplasm that may be hypervascular and is usually associated with metastatic disease at presentation. Understanding the imaging appearances and pathologic bases of esophageal neoplasms is essential for their detection, differential diagnosis, staging, and treatment planning.
Topics: Esophageal Neoplasms; Humans; Image Enhancement; Magnetic Resonance Imaging; Tomography, X-Ray Computed; Ultrasonography
PubMed: 23842973
DOI: 10.1148/rg.334135027 -
Breast Disease 2023The normal imaging appearances of the common agents used in injection mammoplasty and the challenges of mammography screening will be reviewed. (Review)
Review
BACKGROUND
The normal imaging appearances of the common agents used in injection mammoplasty and the challenges of mammography screening will be reviewed.
METHODS
The local database from a tertiary hospital was accessed for imaging cases of injection mammoplasty.
RESULTS
Free silicone is seen as multiple high-density opacities on mammograms. Silicone deposits can often be seen within axillary nodes due to lymphatic migration. Sonographically, a snowstorm appearance is seen when the silicone is diffusely distributed. On MRI, free silicone is hypointense on T1-weighted and hyperintense on T2-weighted images, with no contrast enhancement. Mammograms have a limited role in screening due to the high density of silicone. MRI is often required in these patients.Polyacrylamide gel and hyaluronic acid are seen as multiple collections on mammography. Polyacrylamide gel collections are of the same density as cysts, while hyaluronic acid collections are of higher density but less dense than silicone. On ultrasound, both can appear anechoic or show variable internal echoes. MRI demonstrates fluid signal with hypointense T1-weighted and hyperintense T2-weighted signal. Mammographic screening is possible if the injected material is located predominantly in the retro-glandular space without obscuring the breast parenchyma.On mammograms, autologous fat locules appear as lucent masses. Rim calcification can be seen if fat necrosis had developed. On ultrasound, focal fat collections can demonstrate varying levels of internal echogenicity, depending on the stage of fat necrosis. Mammographic screening is usually possible for patients after autologous fat injection as fat is hypodense compared to breast parenchyma. However, the dystrophic calcification associated with fat necrosis may mimic abnormal breast calcification. In such cases, MRI can be utilized as a problem-solving tool.
CONCLUSION
It is important for the radiologist to recognize the type of injected material on the various imaging modalities and recommend the best modality for screening.
Topics: Humans; Female; Fat Necrosis; Hyaluronic Acid; Breast Neoplasms; Mammography; Mammaplasty; Calcinosis
PubMed: 36872763
DOI: 10.3233/BD-220059