Undifferentiated (embryonal) sarcoma of the liver in middle-aged adults: smooth muscle differentiation determined by immunohistochemistry and electron microscopy

Undifferentiated (embryonal) sarcoma of the liver (UESL) is a rare pediatric liver malignancy that is extremely uncommon in middle-aged individuals. We studied 2 cases of UESL in middle-aged adults (1 case in a 49-year-old woman and the other in a 62-year-old man) by histology, immunohistochemistry, and electron microscopy to clarify the cellular characteristics of this peculiar tumor. One tumor showed a mixture of spindle cells, polygonal cells, and multinucleated giant cells within a myxoid matrix and also revealed focal areas of a storiform pattern in a metastatic lesion. The other tumor was composed mainly of anaplastic large cells admixed with few fibrous or spindle-shaped components and many multinucleated giant cells. In both cases, some tumor cells contained eosinophilic hyaline globules that were diastase resistant and periodic acid-Schiff positive. Immunohistochemically, the tumor cells showed positive staining for smooth muscle markers, such as desmin, alpha-smooth muscle actin, and muscle-specific actin, and also for histiocytic markers, such as alpha-1-antitrypsin, alpha-1-antichymotrypsin, and CD68. Electron microscope examination revealed thin myofilaments with focal densities and intermediate filaments in the cytoplasm of tumor cells. Our studies suggest that UESL exhibits at least a partial smooth muscle phenotype in middle-aged adults, and this specific differentiation may be more common in this age group than in children. Tumor cells of UESL with smooth muscle differentiation in middle-aged adults show phenotypic diversity comparable to those of malignant fibrous histiocytoma with myofibroblastic differentiation.     

Propagation of action potentials from the soma to individual dendrite of cultured rat amacrine cells is regulated by local GABA input

Retinal amacrine cells are interneurons that make lateral and vertical connections in the inner plexiform layer of the retina. Amacrine cells do not possess a long axon, and this morphological feature is the origin of their naming. Their dendrites function as both presynaptic and postsynaptic sites. Half of all amacrine cells are GABAergic inhibitory neurons that mediate lateral inhibition, and their light-evoked response consists of graded voltage changes and regenerative action potentials. There is evidence that the amount of neurotransmitter release from presynaptic sites is increased by spike propagation into the dendrite. Thus understanding of how action potentials propagate in dendrites is important to elucidating the extent and strength of lateral inhibition. In the present study, we used the dual whole cell patch-clamp technique on the soma and the dendrite of cultured rat amacrine cells and directly demonstrated that the action potentials propagate into the dendrites. The action potential in the dendrite was TTX sensitive and was affected by the local membrane potential of the dendrite. Propagation of the action potential was suppressed by local application of GABA to the dendrite. Dual dendrite whole cell patch-clamp recordings showed that GABA suppresses the propagation of action potentials in one dendrite of an amacrine cell, while the action potentials propagate in the other dendrites. It is likely that the action potentials in the dendrites are susceptible to various external factors resulting in the nonuniform propagation of the action potential from the soma of an amacrine cell.     

Novel single nucleotide polymorphisms of the human nuclear factor kappa-B 2 gene identified by sequencing the entire gene

The nuclear factor kappa-B 2 (NFKB2) gene is a member of the NFKB/Rel gene family, which is known to be a pivotal regulator of the acute phase of the inflammatory response and of immune responses. We identified three novel single nucleotide polymorphisms (SNPs) and determined their allelic frequencies, as determined by the sequencing of 48 alleles of the entire gene in a Japanese population sample. Two of the three polymorphisms were identified at nucleotide (nt) position 1837 (T/C) and nt position, 1867 (GG/G) in the upstream region of the gene. The other polymorphism was identified at nt position 2584 (G/T) within intron 1. These polymorphisms will be useful in genetic studies of the processes involved in inflammatory responses and in bone differentiation. Received: October 17, 2000 / Accepted: October 23, 2000     

A comparative study of gut‐associated lymphoid tissue in calf and chicken

The calf contains two types of Peyer's patches (PPs): jejunal and ileal. The ileal PP has been thought to be equivalent to the bursa of Fabricius (BF) as a central lymphoid organ. The morphologies of ileal and jejunal PPs in the calf were compared with those of the BF and the caecal tonsil (CT) in the chicken. Immunoglobulin G–positive (IgG⁺) cells appear in the follicles of them all and exhibited a dendritic appearance after birth. We investigated whether the IgG in these follicles was produced in situ. IgG‐producing cells were detected in the follicular medullas of the jejunal PP and the CT, but not in those of the ileal PP and the BF. CD4⁺ cells were distributed in the follicular medullas of the jejunal PP and the CT, but not in those of the ileal PP and the BF. The data suggest that Ig class switching occurs in both jejunal PP follicles and CT follicles, but does not occur in either the ileal PP follicles or the bursal follicles. Because CD4⁺ T cells would be prerequisite for Ig class switching in these follicles, IgG⁺ cells of the follicular medullas in the ileal PP and the BF would trap immune complexes from the gut lumen. The primary B‐cell repertoire might be selected by gut‐derived antigens in the ileal PP and the BF before seeding the periphery. Anat Rec 266:207–217, 2002. © 2002 Wiley‐Liss, Inc.     

Antifouling blood purification membrane composed of cellulose acetate and phospholipid polymer

The ideal surface of an artificial blood purification membrane needs hemocompatibility and durability of high performance; it should not adsorb any proteins or cells but should still have high permeability in the desired range of solute size. To improve the anti-fouling property of cellulose acetate (CA) membranes, a CA membrane blended with poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)) (PMB30) was designed as a blood purification membrane. The polymer solutions for preparing the membrane were prepared using a solvent mixture composed of N, N-dimethylformamide, acetone, 2-propanol or water. The CA and CA/PMB30 blend membranes with an asymmetric and porous structure were prepared by a phase inversion process.The characteristics of the CA/PMB30 blend membrane, such as structural properties, mechanical properties, and solute permeability were examined with attention to changes in the preparation conditions of the membrane. The CA/PMB30 blend membrane had good water and solute permeability and a sharp molecular weight cut-off property. Moreover, the amount of proteins adsorbed on the CA/PMB30 blend membrane surface was less than that of the original CA membrane and a conventional polysulfone membrane. Adhesion and activation of platelets on the CA/PMB30 blend membrane were reduced compared with that on a CA membrane. In addition, the CA/PMB30 blend membrane showed good permselectivity and an antifouling property during a long time ultrafiltration experiment with protein solutions.     

Mapping nondominant voices into understanding stress-coping mechanisms

This study reports key findings from a research project, which examined the stress and coping mechanisms of several nondominant groups of individuals. The groups were based in Winnipeg, Manitoba, Canada and included (a) Aboriginal individuals with diabetes, (b) individuals with disabilities, and (c) gays and lesbians. Our analyses of personal narratives and life stories have led to develop an interpretive map of findings that depicts mechanisms of how stress and coping operate. Specifically, the interpretive map consists of personal and structural stressors, meanings of stress, and personal and structural resources, as well as of two constructs termed intersectionality and social exclusion. Not only are nondominant voices and lived experiences recognized and incorporated into an emergent interpretive map, but this map also articulates the complex ways in which multiple identities intersect (i.e., intersectionality) and the realities of being excluded socioeconomically, culturally, and politically among nondominant groups (i.e., social exclusion). © 2008 Wiley Periodicals, Inc.     

Microfilamentous type VI collagen in the hyalinized stroma of the hypertrophied ligamentum flavum

Summary Thickened ligamenta flava obtained from 14 patients with spinal canal stenosis were examined with special reference to type VI collagen. The characteristic histological finding in the thickened area was rupture of normal elastic fibre meshwork with resultant fibrosis which usually appeared hyaline. Using an immunohistological method, collagen types VI, I and III were found to be present in the hyaline matrix. Ultrastructural study revealed many microfilamentous structures of type VI collagen admixed in loosely packed, banded collagen fibres. With differential salt precipitation of pepsin-extracted collagen the existence of type VI collagen was confirmed by SDS-polyacrylamide gel electrophoresis analysis and Western blotting analysis using anti-type VI collagen antibody. Quantification of type VI collagen in pepsin-extracted crude collagen samples by an inhibition enzyme-linked immunosorbent assay showed an increasing amount of type VI collagen in the thickened ligamenta flava compared to the normal ligaments. Thus, increase of type VI collagen is the main contribution to the thickening of the ligamentum flavum. This may represent an adaptational and reparative process associated with disruption of elastic fibres.     

Infantile and adult fibrosarcomas of the soft tissues.

Histologic sections of 68 soft-tissue sarcomas initially diagnosed as fibrosarcoma were reviewed, and 36 were excluded because of revised diagnosis. The tumors from the remaining 32 patients were analyzed clinicopathologically, and were classifed into two types; the adult type (22 cases) and the infantile type (10 cases). The adult type fibrosarcoma occurred in adults aged 25 to 67 years and consisted of spindle-shaped fibroblastic cells which formed interlacing bundles accompanied by variable amounts of collagen or reticulin fibers. The infantile fibrosarcoma affected children below the age of seven years in this series and was characterized by proliferation of immature fibroblasts forming indistinct bundles, frequently exhibiting areas of an angiosarcoma-like pattern and cavernous blood vessels. The authors expressed the view that infantile fibrosarcoma should be separated from adult fibrosarcoma, because between these two types of fibrosarcoma there were marked differences in the histologic feature as well as in the age, sex and anatomical distributions.