Inflammatory pseudotumor of lymph nodes: clinicopathologic and immunohistological study of 11 Japanese cases

We report 11 Japanese cases of inflammatory pseudotumor (IPT) of the lymph node. There were 7 males and 4 females with ages ranging from 5 to 68 years (median; 48). Only 2 patients had systemic lymphadenopathy, and all others had involvement of only 1 lymph node group. Constitutional symptoms such as fever were present in 8 patients and laboratory abnormalities were detected in 5. All patients recovered and were alive and well after 2 to 180 months (median; 32 months). Histologically, the process mainly involved the connective tissue framework of the lymph node, secondarily spreading into the lymph node parenchyma and the perinodal tissue. It was characterized by a storiform growth pattern of myofibroblasts, marked vascularity with associated vascular lesions, and a polymorphous reactive cellular infiltrate in a collagen-rich stroma. An immunohistochemical study revealed numerous myofibroblasts, histiocytes, and vascular endothelial cells expressing vascular endothelial growth factor (VEGF) in 6 cases. It was suggested that VEGF may be involved, in part, in the induction of the angiogenesis of IPT. Moreover, the present study indicates that follicular dendritic cell sarcoma, nasal T/natural killer cell lymphoma, and anaplastic large cell lymphoma should be added to the differential diagnosis from IPT of the lymph node. Int J Surg Pathol 9(3):207-214, 2001     

Murine stromal cell line HESS-5 maintains reconstituting ability of Ex vivo-generated hematopoietic stem cells from human bone marrow and cytokine-mobilized peripheral blood

Human bone marrow (BM) or mobilized peripheral blood (mPB) CD34(+) cells have been shown to loose their stem cell quality during culture period more easily than those from cord blood (CB). We previously reported that human umbilical CB stem cells could effectively be expanded in the presence of human recombinant cytokines and a newly established murine bone marrow stromal cell line HESS-5. In this study we assessed the efficacy of this xenogeneic coculture system using human BM and mPB CD34(+) cells as materials. We measured the generation of CD34(+)CD38(-) cells and colony-forming units, and assessed severe-combined immunodeficient mouse-repopulating cell (SRC) activity using cells five days after serum-free cytokine-containing culture in the presence or the absence of a direct contact with HESS-5 cells. As compared with the stroma-free culture, the xenogeneic coculture was significantly superior on expansion of CD34(+)CD38(-) cells and colony-forming cells and on maintenance of SRC activity. The PKH26 study demonstrated that cell division was promoted faster in cells cocultured with HESS-5 cells than in cells cultured without HESS-5 cells. These results indicate that HESS-5 supports rapid generation of primitive progenitor cells (PPC) and maintains reconstituting ability of newly generated stem cells during ex vivo culture irrespective of the source of samples. This xenogeneic coculture system will be useful for ex vivo manipulation such as gene transduction to promote cell division and the generation of PPC and to prevent loss of stem cell quality.     

Platelet-activating factor in Japanese cedar pollinosis

Japanese cedar pollinosis is a typical allergic disease and has recently become a big social problem. Many population are suffering from this disease every year from the end of February to the beginning of April. In this study, we planned to examine the role of platelet-activating factor (PAF) in this disease, because PAF has been known to be one of the potent chemical mediators in allergic and inflammatory reactions and many evidences indicate that PAF is deeply involved in the pathogenesis of bronchial asthma, a typical allergic disease. We measured the concentrations of the PAF derivative (lyso-PAF) in serum from patients with cedar pollinosis during the pollen season. The level of lyso-PAF in serum from untreated patients with cedar pollinosis (87.8 +/- 8.7 unit.) was significantly higher than that in healthy control (54.9 +/- 7.7 unit.). We also tested the effect of an anti-allergic drug on the level of serum lyso-PAF of cedar pollinosis. Eighteen pairs of serum samples from patients with cedar pollinosis were employed in this study. Lyso-PAF levels after two weeks' therapy with ketotifen (2 mg/day), an anti-allergic drug, decreased the levels significantly (from 82.6 unit to 41.3 unit). These results suggest that PAF could play some important role in cedar pollinosis and that the clinical effect of anti-allergic drug could be partially due to the anti-PAF action.     

Studies on in vitro evaluation for the biocompatibility of various biomaterials: inhibitory activity of various kinds of polymer microspheres on metabolic cooperation

Gap junctional intercellular communication is a function that plays an important role in maintaining cell and tissue homeostasis and in regulating cell growth, development, and differentiation. Change in this function when contacting fibroblasts with various polymer microspheres was estimated using the metabolic cooperation assay system. When the cells were in contact with the microspheres after their adhesion onto a substrate, the function did not alter. However, when they were in contact with precoated microspheres on test dishes, the function was inhibited as the quantity of microspheres increased. Moreover, the inhibition level increased as the diameters of polyethylene and polystyrene microspheres decreased. However, no inhibition was observed if precoated microspheres were composed from poly(L-lactic acid). These findings suggest that the size and the material of microspheres, and how cells recognize the microspheres, are factors affecting cell function of gap junctional intercellular communication. Therefore, estimating this function may provide valuable information about the biocompatibility of many kinds of materials even in the form of particles.     

Projection of the retinal ganglion cells to the tectum differentiated from the prosencephalon.

The alar plate of the prosencephalon differentiates into a tectum-like structure when transplanted into the mesencephalon around the 10-somite stage. Here, we report on the projection pattern of the retinal ganglion cells to the transplants. Optic nerve fibers were labeled with horseradish peroxidase (HRP) and 3H-proline, and the innervation of the optic nerve fibers to the chimeric tectum was analyzed by HRP histochemistry on whole-mounted specimens, by autoradiography and by electron microscopy on embryonic day 16. In the chimeric tectum, the transplant was distinguished from the host by difference in nuclear structure between the quail and the chick cells. It was shown that the transplant had the laminar pattern of the optic tectum when the transplant was integrated into the host mesencephalon. The whole-mount HRP histochemistry showed that the optic nerve fibers extend to the transplants. Autoradiography showed that the distribution pattern of silver grains was similar in both the host and the transplant. These results may indicate that the optic nerve fibers turn to the transplant and terminate on the transplant. Electron microscopy further confirmed that optic nerve fibers ended by making synaptic contacts with the dendrites in the transplant region of the tectum. These results indicate that the transplant with the laminar pattern of the optic tectum is a true tectum receiving input from the eye.     

Phylogenetic association of Pneumocystis carinii with the 'Rhizopoda/Myxomycota/Zygomycota group' indicated by comparison of 5S ribosomal RNA sequences

The cytoplasmic 5S ribosomal RNA (5S rRNA) sequence from Pneumocystis carinii was determined. A sequence comparison matrix of 382 eukaryote 5S rRNA sequences and an evolutionary tree were constructed to establish the phylogenetic position of Pneumocystis. The data suggest that Pneumocystis is associated with the Rhizopoda/Myxomycota/Zygomycota group (= 'Protista fungi') but not with common fungi, such as Ascomycota or Basidiomycota, nor with other protozoa.     

Overexpression of human thioredoxin in transgenic mice controls oxidative stress and life span

Transgenic (Tg) mice overexpressing human thioredoxin (TRX), a small redox-active protein, were produced to investigate the role of the protein in a variety of stresses. Bone marrow cells from TRX-Tg mice were more resistant to ultraviolet C-induced cytocide compared with those from wild type (WT) C57BL/6 mice. TRX-Tg mice exhibited extended median and maximum life spans compared with WT mice. Telomerase activity in spleen tissues in TRX-Tg mice was higher than that in WT mice. These results suggest that overexpression of TRX results in resistance against oxidative stress and a possible extension of life span without apparent abnormality in mammals.     

Secretory leukoprotease inhibitor augments hepatocyte growth factor production in human lung fibroblasts

Secretory leukoprotease inhibitor (SLPI), an 11.7-kD nonglycosylated serine protease inhibitor, is produced and released into the fluids of mucosal surfaces including human lung. It comprises two domains with homologous amino acid sequences: the N-terminal domain possessing antibacterial activity, and the C-terminal domain with antiprotease activity. Here we report the positive regulation of hepatocyte growth factor (HGF) production in human lung fibroblasts exerted by SLPI or its C-terminal domain under physiologic concentrations (1 to 10 microM). This HGF production by SLPI was unaffected by the addition of interleukin (IL)-1 receptor antagonist. In contrast, human skin fibroblasts exerted no SLPI-stimulated increase in HGF production, despite the fact that IL-1beta increased HGF production with an intensity similar to that of human lung fibroblasts. Both the time-course and dose-response studies in human lung fibroblasts revealed that the induction of HGF messenger RNA (mRNA) and protein occurred in parallel, indicating that the mechanism existed at the steady-state mRNA level. A synthetic elastase inhibitor failed to induce HGF, but alpha(1)-antitrypsin also stimulated HGF production in lung fibroblasts. Inactivation of the antiprotease activity of SLPI or its C-terminal domain by an oxidizing agent (N-chlorosuccinimide) abolished their stimulatory effect on HGF production. These findings demonstrate that SLPI exerts a novel HGF induction and functions as an anti-inflammatory and regenerative factor in addition to its role in protease inhibition.     

The effect of jogging on P300 event related potentials

Physical exercise has beneficial effects not only on cardiovascular system and fat metabolism, may also directly effect the cognitive process. We studied the effect of physical exercise on cognitive processes by measuring the P300 event related-potential (ERP) after jogging. Seven well-trained joggers were enrolled in this study and the P300 potentials using auditory oddball paradigm. ERPs were measured before and after 30 minutes of jogging. The amplitude of the P300 significantly increased after jogging compared to values recorded before jogging. These findings suggest that jogging has the effect of facilitating cognitive processes involved in generation of the P300.