Characterization of CO3Ap-collagen sponges using X-ray high-resolution microtomography

For reconstruction and regeneration of hard tissues, scaffold biomaterials with large size pores and high porosity are important, in addition to their roles as supporting frames. To develop a new biodegradable scaffold biomaterial, CO3Ap, which has crystallinity and a chemical composition similar to bone, was synthesized at pH 7.4 and 60 degrees C. Then, the CO3Ap was mixed with a neutralized collagen gel and the CO3Ap-collagen mixtures with different kinds of CO3Ap contents and porosity were lyophilized into sponges. Scanning electron micrography (SEM) observation of CO3Ap-collagen sponges showed favorable pores for cell invasion. Approximately 50-300 microm size pores appeared to continue through the bulk. Higher magnification of the sponge showed a better adhesion between CO3Ap crystals and collagen. X-ray high-resolution microtomography revealed a clear image of the 3D structure of the sponges. The porosity of 0, 70 and 90%(w/w) CO3Ap-collagen sponges was 79.2 +/- 2.8%, 72.6 +/- 2.4% and 48.9 +/- 6.1%, respectively. The 70%(w/w) CO3Ap-collagen sponge appeared to be the most favorable biomaterial from the viewpoint of natural bone properties. Mouse osteoblast MC3T3-E1 cells were cultured in alphaMEM with 10% FCS for 2 weeks. Hematoxylin-eosin staining confirmed osteoblast cells invaded well into the CO3Ap-collagen sponge. These sponges are expected to be used as hard tissue scaffold biomaterials for therapeutic uses.     

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     

Novel missense mutations in the human lysosomal sialidase gene in sialidosis patients and prediction of structural alterations of mutant enzymes

Three novel missense mutations in the human lysosomal sialidase gene causing amino acid substitutions (P80L, W240R, and P316S) in the coding region were identified in two Japanese sialidosis patients. One patient with a severe, congenital form of type 2 sialidosis was a compound heterozygote for 239C-to-T (P80L) and 718T-to-C (W240R). The other patient with a mild juvenile-onset phenotype (type 1) was a homozygote for the base substitution of 946C-to-T (P316S). None of these mutant cDNA products showed enzymatic activity toward an artificial substrate when coexpressed in galactosialidosis fibroblastic cells together with protective protein/cathepsin A (PPCA). All mutants showed a reticular immunofluorescence distribution when coexpressed with the PPCA gene in COS-1 cells, suggesting that the gene products were retained in the endoplasmic reticulum/Golgi area or rapidly degraded in the lysosomes. Homology modeling of the structural changes introduced by the mutations predicted that the P80L and P316S transversions cause large conformational changes including the active site residues responsible for binding the sialic acid carboxylate group. The W240R substitution was deduced to influence the molecular surface structure of a limited region of the constructed models, which was also influenced by previously identified V217M and G243R transversions. Received: Stptember 21, 2001 / Accepted: November 2, 2001     

Decreased prolactin level in secretory granules and their increased exocytosis in estrogen-induced pituitary hyperplasia in rats treated with a dopamine agonist.

Treatment with bromocriptine (CB) stimulates the release of secretory granules from human prolactinomas by exocytosis in spite of a remarkable decrease in serum prolactin (PRL) levels. In an attempt to elucidate the reasons for this phenomenon, secretory granules were analyzed in estrogen-induced pituitary hyperplasia in rats which served as a model of human disease. The amount of protein contained in cell fractions rich in secretory granules was the same in CB-treated pituitaries as that in the controls, whereas PRL levels decreased to about a half the level of the controls. Morphometric analysis using point-counting and electron immunocytochemistry revealed that the PRL concentrations in secretory granules decreased to about 50% after CB-treatment. Serum PRL levels estimated by counting the exocytotic secretory granules were remarkably lower in CB-treated rats than in the controls. It was suggested that the composition of secretory granules changed or that nonhormonal constituents in the granules disintegrated more slowly after CB treatment, thus allowing exocytosed granules to be observed more frequently. Additionally CB might also suppress a bypass release of PRL by which PRL is secreted without being packaged into secretory granules.     

The frequency of patients with positive HIV-antibody in the various groups and the prognosis of these patients treated with SNMC

Among 300 patients receiving blood and/or blood products because of blood disorders, 3 (1%) were positive for HIV by ELISA. However, 3 patients were thought to be false positive because they had received bolus injection of gamma-globulin and their serum became negative after 6 months. Moreover, no viral inclusion or HIV-antigen was detected. In 30 patients with hemophilia and related disorders, 21 (70%) were positive by ELISA, Immunofluorescence, Passive-agglutination and Western Blot method. Immunodeficiency, as reflected by decreases of CD 4/8 ratio and NK activity, was successfully treated with high-dose of Stronger Neo-Minophagen C.     

Expression of EGF, EGF-receptor, p53, v-erb B and ras p21 in colorectal neoplasms by immunostaining paraffin-embedded tissues

Immunohistochemical studies were performed to clarify the significance of the expression or overexpression of epidermal growth factor (EGF), EGF-receptor (EGFR), p53, v- erb B, ras p21 in 23 cases each of tubular adenoma and adenocarcinoma. The expression of EGF, EGFR, p53, v- erb B, and ras p21 in paraffin-embedded tissues, from 46 patients with colorectal tumors (adenoma: 23 cases; 14 mild dysplasia, six moderate dysplasia, three severe dysplasia, adenocarcinoma: 23 cases; 17 well differentiated, two moderately differentiated, three poorly differentiated, one mucinous carcinoma was analyzed immunohistochemically using anti-EGF, EGFR, p53, v- erb B and ras p21 antibodies. The EGF and ras p21 tended to express more strongly in carcinoma cases than in the adenoma cases, and in severe and moderate dysplasia than in mild dysplasia (EGF: stained positive in five adenomas [21.74%] and 17 adenocarcinomas [73.91%]; ras p21: stained positive in six adenomas [26.09%] and 14 adenocarcinomas [60.87%]. The EGFR stained positive in two adenomas (8.70%) and two adenocarcinomas (8.70%). The p53 and v- erb B showed positive staining only in the carcinoma cases (p53: stained positive in four cases [17.39%]; v- erb B: stained positive in eight cases [34.78%]). This study suggests that these factors seem to have some role in the progression of colon neoplasms. It suggests that genetic alteration is not always equal to the overexpression of protein products, but that it reflects them well, and that the staining makes some contribution to differential diagnosis in colorectal neoplasms.     

Immunogenetic background of patients with autoimmune fatigue syndrome

We have previously reported that approximately 50% of children with chronic nonspecific complaints were positive for antinuclear antibodies (ANA), and that a novel autoantibody to a 62 kD protein (anti-Sa) was found in 40% of these ANA-positive patients. Therefore, we proposed a distinct disease entity termed autoimmune fatigue syndrome (AIFS). We hypothesized that if autoimmune mechanisms did play an important role in the pathogenesis of AIFS, it is possible that it is immunogenetically regulated as observed in other autoimmune disorders. In order to examine the immunogenetic background of AIFS patients, HLA-A, -B, -C, and -DR loci were analyzed serologically in 61 AIFS patients. AIFS was found to be positively associated with the class I antigen HLA-B61 and with the class II antigen HLA-DR9, with odds ratios of 2.77 (p = 0.015, Pcorr = 0.48) and 2.60 (p= 0.012, Pcorr = 0.17), respectively. A negative association was also found between AIFS and HLA-DR2 with odds ratio of 0.25 (p = 0.029, Pcorr = 0.041). When comparing anti-Sa positive AIFS patients with healthy controls, the odds ratios associated with HLA-B61, DR9, and DR2 were 3.42 (p = 0.021, Pcorr = 0.22), 3.96 (p = 0.0011, Pcorr = 0.015), and 0.16 (p = 0.0022, Porr = 0.031), respectively. Thus, the HLA associations observed in this study suggested that immunogenetic background might play a role in AIFS.     

Encoding-related brain activity during deep processing of verbal materials: a PET study

The recent advent of neuroimaging techniques provides an opportunity to examine brain regions related to a specific memory process such as episodic memory encoding. There is, however, a possibility that areas active during an assumed episodic memory encoding task, compared with a control task, involve not only areas directly relevant to episodic memory encoding processes but also areas associated with other cognitive processes for on-line information. We used positron emission tomography (PET) to differentiate these two kinds of regions. Normal volunteers were engaged in deep (semantic) or shallow (phonological) processing of new or repeated words during PET. Results showed that deep processing, compared with shallow processing, resulted in significantly better recognition performance and that this effect was associated with activation of various brain areas. Further analyses revealed that there were regions directly relevant to episodic memory encoding in the anterior part of the parahippocampal gyrus, inferior frontal gyrus, supramarginal gyrus, anterior cingulate gyrus, and medial frontal lobe in the left hemisphere. Our results demonstrated that several regions, including the medial temporal lobe, play a role in episodic memory encoding.