The unexpected appearance of T hyperintensities, mostly in the dentate nucleus and the globus pallidus, during nonenhanced MRI was reported in 2014. This effect is associated with prior repeated administrations of gadolinium (Gd)-based contrast agents (GBCAs) in patients with a functional blood-brain barrier (BBB). It is widely assumed that GBCAs do not cross the intact BBB, but the observation of these hypersignals raises questions regarding this assumption.
View Article and Find Full Text PDFPurpose: The aim of this study was to investigate, based on in-depth multimodal imaging, the presence of Gd deposits, their ultrastructure, location, and co-location with endogenous elements, in the cerebellum, after repeated administrations of gadolinium-based contrast agents (GBCAs).
Methods: Rats sensitized by subtotal nephrectomy received 20 daily intravenous injections of 0.6 mmol Gd/kg for 5 weeks of commercial forms of either gadoterate, gadobenate or gadodiamide, or saline (n = 2/group).
Routine diagnostic electron microscopy of primary ciliary dyskinesia (PCD) is based on the findings of ultrastructural defects of axonemal components. Assessment of the typical abnormalities can be enhanced by improving the sample preservation status using tannic acid (TA) as additive in the biopsy fixation or processing steps. Another option is the implementation of computer-assisted image analysis tools.
View Article and Find Full Text PDFWhile not acutely toxic, chronic hepatic effect of certain gadolinium chelates (GC), used as contrast agent for magnetic resonance imaging, might represent a risk in renally-impaired patients due to free gadolinium accumulation in the liver. To answer this question, this study investigated the consequences of the presence of small amounts of either a soluble gadolinium salt ("free" Gd) or low-stability chelating impurity in the pharmaceutical solution of gadoteric acid, a macrocyclic GC with high thermodynamic and kinetic stabilities, were investigated in renally-impaired rats. Renal failure was induced by adding 0.
View Article and Find Full Text PDFIn our case, a 45-year-old male patient had multiple fractures accompanied by hypophosphatemia. FGF-23 levels were significantly increased, and total body magnetic resonance imaging (MRI) revealed a tumor mass located at the distal tibia leading to the diagnosis of tumor-induced osteomalacia (TIO). After resection of the tumor, hypophosphatemia and the increased levels of FGF-23 normalized within a few days.
View Article and Find Full Text PDFA putative involvement of the vasculature seems to play a critical role in the pathophysiology of graft-versus-host disease (GVHD). We aimed to characterize alterations of mesenteric resistance arteries in GVHD in a fully MHC-mismatched model of BALB/c mice conditioned with total body irradiation that underwent transplantation with bone marrow cells and splenocytes from syngeneic (BALB/c) or allogeneic (C57BL/6) donors. After 4 weeks, animals were sacrificed and mesenteric resistance arteries were studied in a pressurized myograph.
View Article and Find Full Text PDFObjectives: In rheumatoid arthritis, inadequate cortisol secretion was observed relative to inflammation, but reasons are unknown. Human adrenal glands cannot be investigated due to ethical reasons. Thus, a model of arthritis was studied to test inadequate glucocorticoid secretion and adrenocortical alterations.
View Article and Find Full Text PDFBackground: In renal Fanconi's syndrome, dysfunction in proximal tubular cells leads to renal losses of water, electrolytes, and low-molecular-weight nutrients. For most types of isolated Fanconi's syndrome, the genetic cause and underlying defect remain unknown.
Methods: We clinically and genetically characterized members of a five-generation black family with isolated autosomal dominant Fanconi's syndrome.
Infertility is sometimes more a man's problem than a woman's, failure of one or both of the testes to descend (cryptorchidism) being the most frequent genital malformation in boys. Untreated, the undescended testis impairs germ cell development and significantly reduces adult fertility. A-dark spermatogonia are the stem cells for all future spermatozoa, and their depletion can be reliably estimated in resin semithin sections.
View Article and Find Full Text PDFUltrastruct Pathol
October 2013
Here we describe a novel approach for the isolation and biochemical characterization of pathogen-containing compartments from primary cells: We developed a lipid-based procedure to magnetically label the surface of bacteria and visualized the label by scanning and transmission electron microscopy (SEM, TEM). We performed infection experiments with magnetically labeled Mycobacterium avium, M. tuberculosis and Listeria monocytogenes and isolated magnetic bacteria-containing phagosomes using a strong magnetic field in a novel free-flow system.
View Article and Find Full Text PDFPrimary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder characterized by defective cilia and flagella motility. Chronic destructive-airway disease is caused by abnormal respiratory-tract mucociliary clearance. Abnormal propulsion of sperm flagella contributes to male infertility.
View Article and Find Full Text PDFPrimary spindle cell neoplasms of the thyroid gland are quite rare. They encompass a heterogeneous group of benign and malignant lesions of mesenchymal and epithelial origin. We herein describe two unusual follicular thyroid adenomas dominated by spindle cells with occasional areas of colloid-forming follicular differentiation.
View Article and Find Full Text PDFPurpose: To detect the ultrastructural site of gadolinium retention in skin by using an animal model of nephrogenic systemic fibrosis and compare a linear, low-stability gadolinium chelate (formulated gadodiamide) with a macrocylic, high-stability gadolinium chelate (gadoterate meglumine).
Materials And Methods: Experimental procedures were performed according to rules and regulations laid down by the UK Home Office (Animal Procedures Act of 1986). Male Wistar rats were subjected to 5/6 subtotal nephrectomy (creatinine clearance, 25% normal).
Extracellular deposition of altered autologous protein (amyloid protein) within the dermis is the hallmark of cutaneous amyloidoses and systemic amyloidoses with cutaneous involvement. Amyloidoses may be acquired or hereditary in nature and subclassification differentiates between primary amyloidosis (no obvious predisposing disease) and secondary amyloidosis (specific underlying disease). More than 26 different proteins and peptides have been identified as amyloid precursors and these proteins are used to subclassify this heterogeneous group of diseases.
View Article and Find Full Text PDFUnlabelled: Background. Encapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD) characterized by the development of an extensive fibrosis of the visceral peritoneum that may eventually lead to intestinal constriction. Its cause remains elusive.
View Article and Find Full Text PDFBackground: The manufacturers of permanent injectable fillers claim that their products are widely inert, biocompatible, atoxic, and nonimmunogenic. There are polymer gels without microparticles on the market and combination products that use collagen suspension or a hyaluronic acid gel as a vector to which polymer microspheres or polygonal particles are added. The filling effect of the polymer gels is based on the volume injected and, for the combination gels, partly on the volume injected and partly on the intended host foreign-body reaction to the microparticles.
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
October 2009
Splanchnic vasodilation is the pathophysiological hallmark in the development of the hyperdynamic circulatory syndrome in liver cirrhosis and portal hypertension. This has been attributed so far mainly to a marked vascular hyporeactivity to endogenous vasoconstrictors. However, myogenic tone and vessel stiffness have not been addressed in mesenteric arteries in liver cirrhosis.
View Article and Find Full Text PDFSkeinoid fibers are globular, brightly eosinophilic periodic Schiff stain (PAS)-positive extracellular collagen deposits commonly seen in gastrointestinal stromal tumors (GIST) of the small bowel. However, smooth-surfaced hyaline globules are occasionally encountered in leiomyomatous GI neoplasms and may be mistaken for true skeinoid fibers. We investigated a total of 93 histologically and immunohistochemically well-characterized true smooth muscle neoplasms of the GI tract for the presence of hyaline globules.
View Article and Find Full Text PDFGene transfer to the retina using recombinant adeno-associated viral (rAAV) vectors has proven to be an effective option for the treatment of retinal degenerative diseases in several animal models and has recently advanced into clinical trials in humans. To date, intracellular trafficking of AAV vectors and subsequent capsid degradation has been studied only in vitro, but the fate of AAV particles in transduced cells following subretinal injection has yet to be elucidated. Using electron microscopy and western blot, we analyzed retinas of one primate and four dogs that had been subretinally injected with AAV2/4, -2/5, or -2/2 serotypes and that displayed efficient gene transfer over several years.
View Article and Find Full Text PDFHuman immunodeficiency virus type-1 (HIV-1) Pr55(Gag) virus-like particles (VLP) represent an interesting HIV vaccine component since they stimulate strong humoral and cellular immune responses. We demonstrated that VLP expressed by recombinant baculoviruses activate human PBMC to release pro-inflammatory (lL-6, TNF-alpha), anti-inflammatory (IL-10) and Th1-polarizing (IFN-gamma) cytokines as well as GM-CSF and MIP-1alpha in a dose-and time-dependent manner. Herein, residual baculoviruses within the VLP preparations showed no or minor effects.
View Article and Find Full Text PDFBackground: Human bocavirus (HBoV) was recently described as a new member of the Parvoviridae family, and its possible association with respiratory illness in infants has been discussed. To date, HBoV genomes have been detected worldwide in respiratory tract samples obtained from children with pulmonary diseases, whereas only limited data on virus-specific immunity are available, mainly because of the lack of recombinant viral antigens.
Methods: HBoV viruslike particles (VLPs) were produced in insect cells and characterized by electron microscopy and cesium chloride gradient centrifugation.