Importance of a biofouling-resistant phospholipid polymer to create a heparinized blood-compatible surface

Heparinization is believed to be one of the methods to suppress thrombus formation on blood-contacting surfaces. However, this study hypothesizes that heparinization alone might not be sufficient to provide a blood-compatible surface; that is, a surface property that resists biofouling is necessary to obtain an effective heparin-modified surface. 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers with 2-aminoethyl methacrylate (AEMA) were synthesized to immobilize heparin through ionic bonding. The primary amino groups of AEMA were considered to be the polymer surface because the zeta-potential of the surface was positive when the mole fraction of the AEMA units was above 0.2. The antithrombogenic character of the polymer surface modified with heparin was evaluated by both Lee-White and microsphere column methods. The coagulation period of human whole blood in the absence of anticoagulant in glass tubing coated with the MPC polymer was longer than that in the original glass tube. Cell adhesion was completely inhibited on the MPC polymer surface after contact with human whole blood without anticoagulant. However, many adherent blood cells were observed on poly(2-ethylhexyl methacrylate-co-AEMA) (no MPC unit) even after heparinization. These results strongly indicate that the MPC polymer is a useful substrate where the heparin works well and that the heparin-immobilized MPC polymer has superior blood compatibility to the simple MPC polymer.     

Variation of the conserved neutralizing epitope in influenza B virus victoria group isolates in Japan

For almost 20 years, the neutralizing-epitope site specific for influenza B virus Victoria group isolates was conserved at the "tip" of the hemagglutinin molecule; however, it was not detected in half of the isolates from the 2002-2003 epidemic in Japan. Amino acid substitutions (D164E or N165K) were observed at the "tip", and the epitope was altered. The viral antigenicities were affected, and human antibodies did not substantially inhibit the hemagglutination in the hemagglutination inhibition tests. It is suspected that such variants will be important in future epidemics.     

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.     

CUSHING'S SYNDROME WITH BILATERAL MULTINODULAR ADRENAL HYPERPLASIA

An unusual case of Cushing's syndrome of a 59-year-old man with bilateral multinodular adrenal hyperplasia and microadenoma of the pituitary gland is presented. Failure to suppress plasma Cortisol with large doses of dexamethasone may suggest autonomous growth of hyperplastic nodules of the adrenals, which were at first induced by prolonged stimuli of ACTH from the microadenoma of the pituitary gland. ACTH could not be detected in the microadenoma cells on paraffin sections, while Crooke's cells were strongly positive for ACTH. The interrelation between bilateral multinodular adrenal hyperplasia and pituitary microadenoma is discussed.     

The vomeronasal chemosensory system as a route of neuroinvasion by herpes simplex virus

We have investigated the potential of neurotropic microbes to invade the central nervous system (CNS) via the peripheral nervous system. Herpes simplex virus type 1 (HSV-1) strain KH6 and herpes simplex virus type 2 (HSV-2) strain 186 were found to infect chemosensory neurons in the vomeronasal organ (the pheromone detector) following intranasal inoculation of mice. HSV-1 strain KH6 infection was further transmitted to the accessory olfactory bulb (first relay), the medial amygdala (second relay), and the bed nucleus of the stria terminalis and the ventromedial hypothalamus (third relay). HSV-1 strain KH6 also targeted the olfactory and trigeminal systems. HSV-2 strain 186 predominantly attacked the brainstem including the trigeminal system. While both viruses did not induce apoptosis in infected chemosensory neurons, they did in infected brain tissue. These results suggest that neurotropic viruses can invade the brain by infecting vomeronasal chemosensory neurons and that the restrained induction of apoptosis in the infected neurons may facilitate viral transmission to the CNS.     

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     

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.     

Quantitative Analysis of Mycobacterial and Propionibacterial DNA in Lymph Nodes of Japanese and European Patients with Sarcoidosis

The cause(s) of sarcoidosis is unknown. Mycobacterium spp. are suspected in Europe and Propionibacterium spp. are suspected in Japan. The present international collaboration evaluated the possible etiological links between sarcoidosis and the suspected bacterial species. Formalin-fixed and paraffin-embedded sections of biopsy samples of lymph nodes, one from each of 108 patients with sarcoidosis and 65 patients with tuberculosis, together with 86 control samples, were collected from two institutes in Japan and three institutes in Italy, Germany, and England. Genomes of Propionibacterium acnes, Propionibacterium granulosum, Mycobacterium tuberculosis, Mycobacterium avium subsp. paratuberculosis, and Escherichia coli (as the control) were counted by quantitative real-time PCR. Either P. acnes or P. granulosum was found in all but two of the sarcoid samples. M. avium subsp. paratuberculosis was found in no sarcoid sample. M. tuberculosis was found in 0 to 9% of the sarcoid samples but in 65 to 100% of the tuberculosis samples. In sarcoid lymph nodes, the total numbers of genomes of P. acnes or P. granulosum were far more than those of M. tuberculosis. P. acnes or P. granulosum was found in 0 to 60% of the tuberculosis and control samples, but the total numbers of genomes of P. acnes or P. granulosum in such samples were less than those in sarcoid samples. Propionibacterium spp. are more likely than Mycobacteria spp. to be involved in the etiology of sarcoidosis, not only in Japanese but also in European patients with sarcoidosis.