Ultrastructural localization of laminin-5 (gamma2 chain) in the rat peri-implant oral mucosa around a titanium-dental implant by immuno-electron microscopy

Laminin-5 (Ln-5) is an important molecule associated with epithelial cell adhesion and migration. In the gingiva around the tooth, Ln-5 localizes within basement membranes between the junctional epithelium (JE) and the tooth or connective tissue. Recently, we reported that in the oral mucosa around a dental implant, Ln-5 is expressed within the basement membranes at the implant-peri-implant epithelium (PIE) interface, and at the PIE-connective tissue interface. However, the ultrastructural localization of Ln-5 within or along the PIE has not yet been reported. Therefore, peri-implant oral mucosa was treated with anti-Ln-5 (gamma2 chain) antibody and examined using immuno-electron microscopy. Ln-5 was localized in the cells of the innermost-third layer and basal layer of the PIE. A 100-nm-wide Ln-5-positive internal basal lamina (basement membrane) and hemidesmosomes as adhesion structures were formed at the apical portion of the implant-PIE interface. However, at the upper-middle portion of the interface, these adhesion structures were not observed. Furthermore, at the PIE-connective tissue interface, the Ln-5-positive external basal lamina (basement membrane) and hemidesmosomes were partially deficient. Judging from these findings, we concluded that Ln-5 contributes to the attachment of the PIE to the titanium surface, and that PIE attached to titanium at the apical portion of the dental implant-PIE interface.     

Phase stability after aging and its influence on pin-on-disk wear properties of Ce-TZP/Al2O3 nanocomposite and conventional Y-TZP

Recently zirconia/alumina composites have been examined by many researchers as the new generation of bearing materials in total joint replacements. In this study, the phase stability of a Ce-TZP/Al(2)O(3) nanocomposite and conventional Y-TZP after aging, and its influence on wear resistance, were investigated. Very slight phase transformation was observed in both types of ceramics 18 months after the implantation of Ce-TZP/Al(2)O(3) or Y-TZP samples into rabbit tibiae. However, Y-TZP showed marked phase transformation (approximately 80%) after aging in an autoclave (121 degrees C) for 190 h or in physiological saline at 62 degrees C for 18 months, whereas the new composite remained almost resistant to degradation. According to the results of self-pairing pin-on-disk wear tests using ceramic specimens with or without autoclave aging, the wear factor was almost the same between Ce-TZP/Al(2)O(3) samples with and without aging (6.74 +/- 0.36 x 10(-8) and 6.04 +/- 0.95 x 10(-8) mm(3)/Nm, respectively). In contrast, although non-aged Y-TZP had the lowest wear factor (4.88 +/- 0.51 x 10(-8) mm(3)/Nm) of all specimens tested, aged Y-TZP showed 10-fold greater wear than nonaged Y-TZP. The present study suggests that Ce-TZP/Al(2)O(3) nanocomposite has much greater phase stability than Y-TZP, and that its wear properties are not influenced by aging.     

TAC-101, a benzoic acid derivative, inhibits liver metastasis of human gastrointestinal cancer and prolongs the life-span

We examined the anti-tumor effect of a novel benzoic acid derivative, TAC-101 (4-[3,5-bis(trimethylsilyl) benzamide] benzoic acid) on models with liver metastasis. Oral administration of TAC-101 significantly inhibited spontaneous liver metastasis of AZ-521 (human gastric cancer ) by orthotopic implan-tation to athymic nude mice. It also inhibited both the liver metastasis of AZ-521 induced by intrasplenic injection and the secondary lung metastasis from the liver. In addition, TAC-101 inhibited the proliferation of Co-3 (human colon adenocarcinoma) that formed a single nodule in the liver of athymic nude mice by intrahepatic implantation. The growth inhibitory effect of TAC-101 on AZ-521 experimental liver metastasis was observed when treatment was started on day 7, 14, or 21 which may correspond to the progressive stage of liver metastasis in clinical settings. Multiple administration of TAC-101 (8 mg/kg/day) significantly prolonged survival time of the animals with liver met astasis by intrasplenic injection of AZ-521 (T/C = 230%) and A549 (human lung adenocarcinoma; T/C = 186%). These effects of TAC-101 were stronger than those of 5-FU, CDDP or ATRA. Furthermore, TAC-101 inhibited the binding of AP-1 to DNA on electrophoretic mobility shift assay using nuclear extract of AZ-521 cells, although ATRA did not inhibit. These findings suggested that TAC-101 may be a candidate for a new class of anti-cancer agents for liver metastasis. © Rapid Science Ltd.     

Differential contribution of the FcRγ chain to the surface expression of the T cell receptor among T cells localized in epithelia: analysis of FcRγ-deficient mice

The function of the Fc receptors γ chain (FcR_γ) for the expression of the T cell receptor (TCR) complex and for T cell development, especially for T cells localized in epithelia, was investigated by analyzing FcR_γ-deficient mice. In wildtype mice, CD8αα⁺β^?TCRαβ⁺ T cells of intestinal intraepithelial lymphocytes (i-IEL) utilized CD3ζ homodimers and ζ-FcR_γ heterodimers, whereas CD8α α⁺β^?TCR_γδ⁺ i-IEL used ζ-FcR_γ and FcR_γ homodimers in the TCR complex. On the other hand, these T cells in FcR_γ-deficient mice contained only ζ homodimers. The surface expression of the TCR complex was reduced in CD8αα⁺β^?i-IEL and dendritic epidermal T cells (DETC) in these mice, whereas the development of these T cells was normal. The degree of reduction appeared to depend on the expression level of FcR_γ. In contrast to these populations, TCR_γδ⁺ intraepithelial T cells in reproductive organs (r-IEL) were dramatically decreased, suggesting that the development of r-IEL is FcR_γ-dependent, probably due to the predominant usage of FcR_γ homodimers in the TCR complex. These results indicate that the FcR_γ chain contributes differently to the TCR expression and to the development of T cells localized in epithelia.     

Appearance of high-frequency alpha band with disappearance of low-frequency alpha band in EEG is produced during voluntary abdominal breathing in an eyes-closed condition

This study examined the effects of voluntary abdominal breathing (VAB) on the electroencephalogram (EEG) in 22 healthy subjects. VAB was characterized by prolonged rhythmic contraction of abdominal muscles for 20 min in an eyes-closed condition. The breathing rate was instructed to be very slow, i.e., 3-4 breaths/min (inspiratory time for 6-8s and expiratory time for 9-12s). A low-frequency alpha band appeared immediately after eye closing, but it later disappeared and was replaced by a new development of a high-frequency alpha band 4-5 min after the onset of VAB. The subjects had a feeling of vigor-activity with a tendency of reduced anxiety during and/or after VAB, as assessed by POMS and STAI questionnaire scores. On the other hand, during resting in the eye-closed condition, the disappearance of the low-frequency alpha band was replaced by the occurrence of a theta/delta band. The subjects became drowsy in this condition. We therefore conclude that the increase in high-frequency alpha activity is linked to the state of vigor-activity with a tendency of reduced anxiety. Since the urinary serotonergic level significantly increased after the VAB, we suggest that the serotonergic neurons within the brain may produce the changes in the EEG patterns.     

GLOMERULAR TISSUE INJURY IN IgA NEPHRITIS

The glomerular lesions In 129 cases of IgA nephritis were analyzed. The development of glomerular injury occurred in two ways, one being a chronic mesangial depositive and sclerosing lesion commonly found in most glomeruli, and the other an acute but local injury initiating from the local peripheral glomerular basement membrane abnormality, i.e., thinning and/or splitting, which was seen at least in one third of all cases. The activation of the local coagulatory process could add segmental glomerular changes including small crescents, adhesion, and local tuft necrosis to the mesangial lesion. ACTA PATHOL. JPN. 33; 367–380, 1983.     

Histologic transformation in extranodal non-Hodgkin's lymphoma

Histologic transformation in the course of non-Hodgkin's lymphoma (NHL) has been reported to occur in 18 to 30% of the cases. Less favorable prognosis in cases with initial low grade malignancy followed by emergence of high grade malignancy has been previously described. In the previous literature, the histologic transformation has been examined mostly in nodal NHL. In the present study, histologic transformation in the course was investigated on 20 cases with early extranodal NHL. All these 20 cases were diffuse lymphomas, and were composed of 7 cases with low grade malignancy and 13 cases with high grade malignancy. Histologic transformation was not observed in any of these cases. These findings indicate that the frequency of histologic transformation is much lower in extranodal NHL than in nodal NHL. The prognostic significance of these findings is also discussed.     

Injection-site granulomas resulting from the administration of both leuprorelin acetate and goserelin acetate for the treatment of prostatic cancer.

Although injection-site granulomas caused by leuprorelin acetate have been reported, there have been no reports of granulomas caused by both leuprorelin acetate and goserelin acetate. An 81-year-old man presented with subcutaneous nodules of the abdominal wall and upper arm, where 11.25 mg of leuprorelin acetate had been injected for the treatment of prostate cancer. Because of these nodules, treatment was changed to goserelin acetate. Nevertheless, he presented with another subcutaneous nodule at the injection site. Histological examination showed that these nodules consisted of numerous giant cells that were CD3-positive T lymphocytes and CD68-positive histiocytes associated with granulomatous changes. The granulomas had likely been caused by delayed-type hypersensitivity to leuprorelin acetate injection. The granuloma that formed after goserelin acetate injection might thus have developed owing to the immunogenicity of the previous leuprorelin acetate injections. The patient underwent surgical castration. The present case suggests that both leuprorelin acetate and goserelin acetate can cause injection-site disorders.