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Biomedical subjects

M Iijima

Publications and source records attributed to M Iijima.

At least 91 records · Page 5Linked to original sources

Prurigo pigmentosa (Nagashima) associated with anorexia nervosa.

Prurigo pigmentosa (Nagashima), which is not rare in Japan, is an inflammatory disease of unknown aetiology. The characteristic lesions are pruritic red papules, superseded by reticular hyperpigmentation, characteristically on the back, neck, and chest. We now report a case of prurgio pigmentosa associated with anorexia nervosa. These findings suggest that the ketosis produced by anorexia nervosa may well contribute to the pathogenesis of prurigo pigmentosa.

Adult↗

Flame figures associated with bullous pemphigoid.

We report a case of bullous pemphigoid showing the histological features of flame figures. An 80-year-old man was admitted with multiple, tense, thumb-sized blisters among erythematous plaques on his trunk and limbs. A biopsy showed accumulations of eosinophil granules on the collagen fibers, forming characteristic "flame figures", in addition to the features of bullous pemphigoid. We retrospectively examined biopsy specimens from 34 patients with bullous pemphigoid treated in our department over the last 10 years for the presence of flame figures. They were observed in 3 of these patients (8.8%), all of whom were more than 80 years of age. Our retrospective study indicates that the association of flame figures with bullous pemphigoid is not rare, considering the fact that the present case is only the third report of this association. Our data also suggest that the degree of dermal eosinophilia and the formation of flame figures could be related.

Age Factors↗

A case report of removable partial denture using the dimple-bar telescopic system.

The authors have devised a new attachment for a removable partial denture with a dimple-bar clasp, guiding channels, and a shoulder, named the dimple-bar telescopic system. This system has advantages over the clasp-type retention device in that it not only satisfies esthetic requirements, but also improves the handling and adjustability of the attachment denture. Furthermore, it was shown clinically that the dimple-bar telescopic system was free from food impaction when used as an intracoronal attachment, and maintained a feeling of comfort during tongue movement and speech. We present a typical case in which the dimple-bar telescopic system was used.

Crowns↗

Effect of some physico-chemical properties of matrix on lengthwise and oriented growth of octacalcium phosphate crystal.

Relationship between some physicochemical properties of matrix, such as viscosity, density or structure of the framework, and crystal growth of octacalcium phosphate (OCP) was studied using various concentrations of polyacrylamide gels at 37 degrees C and at pH 6.5. Reaction was carried out in a model system of enamel formation, where calcium solution (30 mM) and phosphate solution (5 mM) were separated by a cation selective membrane with polyacrylamide gel on the PO4 side. OCP grew in ribbon-like morphology in 5-20% polyacrylamide gels. Crystal size of OCP decreased with an increase in gel concentration. In 30% gel, growth of OCP was disturbed, In 7.5% polyacrylamide gel, 1% albumin reduced the crystal size of OCP. In contrast, 1% enamel proteins did not much reduce the crystal size of OCP and OCP crystallized in its characteristic ribbon-like morphology.

Acrylic Resins↗

Two new in vitro calcification systems showing the higher calcifiability of enamel proteins than dentin and bone matrices.

One of the difficulties in simulating in vivo calcification by in vitro experiments is how to prepare and apply a suitable calcifying solution. We have previously developed an entirely new model system consisting of 40% acrylamide gel blocks that contains matrix proteins and is immersed in fetal calf serum at 37 degrees C. (40% gel system) for 18 hr (Connect. Tissue Res., 33, 185, 1995). The gels were analyzed for immobilized calcium. In this system bovine enamel proteins (0.1% in the gel) showed the highest calcifiability among the tested matrices, followed by insoluble bovine dentin, bone and skin collagens. The 40% gel system provides a barrier for high molecular weight inhibitor molecules in the body fluid. The new calcifying system developed in this study consists of the matrix protein sealed in dialysis tubing within a glass chromatography column that was eluted with a calcifying solution. In this system (dialysis tubing system), again the enamel protein showed higher calcifiability than dentin, bone and skin collagens. It was also shown that enamel proteins became not only a reversible opaque gel, but also a relatively-irreversible coagulant, if the solution contained calcium and phosphate ions at concentration below saturation (1 mM calcium and 1 mM phosphate). With both systems combined, deposition and crystal growth of minerals in enamel proteins will be better understood than with previous methods.

Acrylic Resins↗

Effect of Cr and Cu addition on corrosion behavior of Ni-Ti alloys.

The corrosion behavior of three Ni-Ti alloys with compositions as commercial super-elastic orthodontic wires was investigated using polished plate specimens. Corrosion resistance was estimated by potentiodynamic polarization measurement in 0.9% NaCl and 1% lactic acid solutions and analysis of released metals by atomic absorption spectrophotometry. The influence of Cr and Cu addition on the structure of the surface oxide film was examined by X-ray photoelectron spectroscopy (XPS). Addition of 0.19 at% Cr had little effect on the structure of the oxide films and the corrosion resistance of the Ni-Ti alloys. For Ni-Ti-5Cu-0.3Cr alloy, the metallic Cu was enriched at the alloy/oxide film interface, resulting in increased susceptibility to pitting corrosion above +1000 mV. However, the passive current density and the amount of released Ni were not significantly increased by the addition of Cu. The study showed that small amounts of Cr and Cu added to change the super-elastic characteristics do not change the corrosion resistance of the Ni-Ti alloy freely immersed in simulated physiological environments.

Chromium↗

[A case manifested overlapping neuropathologic features of both progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD)].

A 62-year-old man developed clumsiness, vertical ophthalmoplegia, right-side dominant parkinsonism, pyramidal signs, limb-kinetic apraxia and dementia. His brain MRI and SPECT revealed mild fronto-parietal atrophy and hypoperfusion predominately on the right side. At the age of 65, the patient died of sepsis. The duration of his illness was approximately 3 years. Clinical diagnosis was corticobasal degeneration (CBD). On neuropathological examination, there was no neuronal loss and many neurofibrillary tangles (NFTs) in the cerebral cortices. Basal ganglia and substantia nigra showed moderate to severe neuronal loss. And there were many NFTs and argyrophillic threads (threads) in the subthalamic nucleus and nuclei of the brainstem. These findings were almost compatible to those of PSP. However, the following findings were atypical for PSP, 1) mild atrophy and absence of gliosis in the tegmentum of the brain stem, 2) Mild neuronal loss in the subthalamic nucleus and the dentate nucleus without grumose degeneration. Furthermore, characteristic findings were noted on modified Gallyas-Braak stain. Numerous threads and many astrocytic plaques (AP) were shown in cerebral cortices, which were particular to CBD cases. So this case demonstrated neuropathological findings of both PSP and CBD. Therefore, it was difficult to classify this case as either PSP or CBD, and we diagnosed this case as a neuropathological overlapping case of both PSP and CBD.

Aged↗

Human choroid plexus is an uniquely involved area of the brain in amyloidosis: a histochemical, immunohistochemical and ultrastructural study.

To better understand the characteristics of amyloid deposition in the choroid plexus, we examined autopsied brain by routine histology, immunohistochemistry, and electron microscopy in three group of patients: primary systemic amyloidosis (n = 7), cerebral amyloid angiopathy (CAA, n = 6), and controls (n = 3). Three of the CAA patients had Alzheimer's disease. Congophilic, birefringent amyloid deposits of the choroid plexus were seen in six of the seven cases of systemic light chain amyloidosis. Immunohistochemistry revealed that the deposited amyloids had reactivity for immunoglobulin light chain and amyloid P component. Accumulation of macrophages labeled with monoclonal antibodies against CD 68 and major histocompatibility complex class II antigens were observed around the massive amyloid deposits. The presence of approximately 10 nm amyloid fibrils along the epithelial basement membrane as well as in the vascular walls was ascertained by electron microscopy. In CAA, Congo red-positive amyloid deposits were consistently present in meningeal blood vessels and were often found in senile plaques of the cerebral parenchyma; congophilic amyloid deposits were absent in the choroid plexus. Choroid plexus epithelial cells exhibited immunostaining for beta amyloid precursor protein (APP) with N-terminal- and C-terminal-specific antibodies; in particular, consistent staining was obtained for the latter antibody. Immunoreactivity for amyloid beta protein (A beta) with monoclonal antibodies (6E10, 4G8) was often found in choroid plexus epithelial cells. These findings suggest that amyloid deposition of the choroid plexus depends on the major component protein in amyloidosis, and that the choroid plexus may produce APP and A beta protein although A beta amyloidosis is not evident in the choroid plexus.

Aged↗

Transformation of normal human fibroblasts into immortalized cells with the mutant p53 gene and X-rays.

In vitro cell transformation is a valuable approach for studying the mechanisms of multistep carcinogenesis of human cells. Since immortalization is an essential step for in vitro neoplastic transformation of human cells, this study addresses the question of whether mutant p53 contributes to the immortalization process of human cells. The mutant p53 gene (mp53: codon273Arg-His) was introduced into normal human fibroblasts (OUMS-24 line) and a G418-resistant clone, OUMS-24/P6 line, was obtained. This clone showed an extended life span and chromosome abnormalities, but senesced at the 79th population doubling level (PDL). When these cells were subjected to intermittent X-ray treatment, they became an immortalized cell line (OUMS-24/P6X). Although these immortalized cells showed chromosome abnormalities, they were not tumorigenic. On the other hand, normal OUMS-24 cells into which mp53 had not been introduced were not immortalized by the same X-ray treatment. These results indicate that introduction and expression of mp53 alone were not sufficient for immortalization of human cells, and that mutations of the remaining wild-type p53 or other genes may have been necessary for immortalization. In fact, no expression of the wild-type p53 was detected in the immortalized cells by RT-PCR. Expression of p21, which is located downstream of p53, was remarkably reduced in the immortalized cells, resulting in an increase in cdk2 and cdc2 kinase activity. These findings indicate that the p53-p21 cascade may play some role in the immortalization of human cells. On the other hand, there was no significant difference in expression of proteins such as Rb, p16, cdk4, cdk6, cyclin A and cyclin D1 between the normal and immortalized human fibroblasts.

Cell Transformation, Neoplastic↗

An unusual variant of ependymoma with extensive tumor cell vacuolization.

We report a case of ependymoma with unusual vacuolar features arising in the left occipital lobe of a 2-year-old child. The tumor was composed of cells with single or multiple cytoplasmic vacuoles and clear cells. Some cells showed a signet ring-like configuration. Clear cells were compactly arranged and showed an oligodendro-glioma-like appearance. In addition, there were cellular ependymoma-like areas including perivascular pseudorosettes. On immunohistochemistry, glial fibrillary acidic protein and vimentin were mainly detected in cytoplasmic processes, and epithelial membrane antigen (EMA) staining showed granular and small vesicular reactivity. Ultrastructural investigation demonstrated intercellular microrosettes with or without cilia and long zonula adherens-type junctions that are typical of ependymoma. Furthermore, many intracytoplasmic lumina (ICL) were observed. Some ICL had microvilli and some did not. The latter varied in size, and may have fused with each other to develop giant ICL which could correspond to the signet ring-like configuration. Small ICL without microvilli had an appearance similar to that of distended endoplasmic reticula. Serial semithin and ultrathin sections revealed that EMA-positive structures were consistent with ICL containing microvilli and intercellular microrosettes. To determine the presence of unusual vacuolated ependymoma, electron microscopical examination was required. However, light microscopy was useful for detecting EMA-positive microvesicular and granular structures.

Child, Preschool↗

Progressive supranuclear palsy with palatal myoclonus.

We present a case of progressive supranuclear palsy (PSP) with palatal myoclonus occurred in a 64-year-old man. The nucleus olivaris of the medulla oblongata showed high signal intensity on T2-weighted MR images, indicating brainstem tegmental atrophy, which were confirmed as hypertrophy of the nucleus inferior olivaris at autopsy. The characteristic neuropathological findings were marked grumose degeneration of the dentate nucleus, degeneration and gliosis of the superior cerebellar peduncle, and hypertrophy of the bilateral olivary nuclei. As far as we know, although a few cases of PSP with olivary hypertrophy have been described, only one case has presented with palatal myoclonus.

Cerebellum↗

Lithium deficiency reduces thymus weight and alters differential blood count in rats.

Effects of lithium (Li) deficiency and/or immobilization stress on the thymus weight and differential blood count of rats were studied. The thymus weight of the rats fed a low Li diet were lighter than those of rats fed a Li supplemented diet, whether the rats were exposed to stress or not. Of the rats not exposed to stress, those in the low Li diet group showed a significant decrease in the ratios of neutrophils and T helper lymphocytes. However, there was an increase in the total number of lymphocytes in the low Li dietary group. It was shown that Li deficiency altered the responses to stress in rats.

Animals↗

The influence of trace elements on calcium phosphate formation by matrix vesicles.

The effects of two inhibitors, fluoride (F-) and zinc (Zn2+), were studied on the formation of mineral by matrix vesicles (MV) in an in vitro system. Kinetically, mineral formation by MV incubated in a synthetic cartilage lymph (SCL) is characterized by three phases: a lag period, a period of rapid uptake, and finally a period of slow uptake. Zn2+ at > or = 5 microM completely inhibited MV mineralization; at < or = 1 microM, it had little effect on rate of ion uptake, but delayed conversion of an OCP-like intermediate into hydroxyapatite (OHAp). F- at > or = 10 microM reduced the rate of rapid uptake by MV and caused the OCP-like precursor to convert to OHAp. When synthetic OCP was seeded into SCL, mineralization ensued and OHAp became the dominant phase. With Zn2+ present, OCP-like features persisted longer; with F-, the OCP-like features were lost more rapidly. When ACP was seeded into SCL, OHAp formed; Zn2+ at < or = 1 microM caused OCP-like mineral to form. Our findings indicate that Zn2+ stabilizes a noncrystalline precursor in MV regulating the length of the lag period; Zn2+ also favors the formation of an OCP-like intermediate whose growth accounts for the rapid uptake phase. This OCP-like phase appears to nucleate formation of OHAp by MV.

Animals↗

Pale islands in medulloblastoma consist of differentiated cells with low growth potential.

Cerebellar medulloblastomas are the most common embryonal neoplasms occurring in the pediatric age group. Thirty-five specimens from 28 cases of medulloblastoma and variant neoplasms were examined to elucidate the histopathologic significance of the reticulin-free pale islands. In 10 specimens, there were light-looking areas corresponding to pale islands: three specimens from desmoplastic and seven from classic medulloblastoma. The difference in cell population, 1.73-fold more cells in dark areas than in light areas (P < 0.001), seemed to be a major factor in the formation of the biphasic architecture. Immunohistochemically, occasional tumor cells in both areas were found to express neuronal phenotypes. In addition, positive immunoreactivity for glial markers was exceptional. There was significant difference in the staining indices (SI) for cell proliferation markers. The light areas consistently showed low SI values (mean MIB-1 SI, 5.75; mean PCNA SI, 11.8) compared with the dark areas (mean MIB-1 SI, 22.7; mean PCNA SI, 44.9). It is suggested that light areas (pale islands) consist of more differentiated cells of neuronal lineage with relatively low proliferation potential. These tumor cells might proliferate in a group, and then expand, thereby compressing the surrounding tissue to form pale islands.

Adult↗

Rôle of ear piercing in metal allergic contact dermatitis.

To evaluate the effect of ear piercing on sensitization to gold and other metals, diagnostic patch testing with 18 metals was performed. 377 patients (65 men and 312 women, ranging in age from 15 to 78 years; mean 34.2, S.D +/- 15.1 years) were patch tested; 107 had pierced earlobes. Metals were applied on the back for 2 days, and the results read with the ICDRG scoring system 3 days after application. Reactions of + to +3 were regarded as positive. There were significantly more patients reacting to gold chloride (p < 0.001), mercuric chloride and nickel sulfate (p < 0.05) in patients with pierced ears than in those without. Statistical issues included: (i) a significant number of patients with pierced ears referred because of earring dermatitis; (ii) those with pierced ears represented a different age group from those without; (iii) a significant number of patients without eczema in the non-pierced ear group. However, our data suggests that ear piercing is a risk factor not only for nickel but also for gold sensitization. Gold was the second most frequent metal allergen after nickel in the pierced group.

Adolescent↗

Patch test materials for mercury allergic contact dermatitis.

The objective of this study was to define adequate patch test materials to evaluate mercury allergic contact dermatitis. We applied 0.1% and 0.05% mercuric chloride, and 0.5% and 0.2% mercury in petrolatum to systemic eczematous contact-type dermatitis (baboon syndrome), and gold-dermatitis patients. All baboon-syndrome patients reacted not only to mercuric chloride but also to metallic mercury. In gold-dermatitis patients, significantly more patients reacted to mercuric chloride than to metallic mercury (21 of 35, 60%, versus 2 of 19, 10.5%, p < 0.0005). We speculated that sensitization to mercury may be of 2 types: one a reaction to ionized mercury only, the other to both ionized mercury and non-ionized mercury. The possibility that the phenomenon is caused by differences in bioavailability or percutaneous penetration between ionized and non-ionized mercury cannot be ruled out, but could be explored by penetration measurement. For the evaluation of mercury hypersensitivity, it may be more reliable to apply both ionized and non-ionized mercury, rather than only mercuric chloride or ammoniated mercury.

Adult↗

Oriented and lengthwise growth of octacalcium phosphate on collagenous matrix in vitro.

A correlation among the oriented growth of octacalcium phosphate (OCP), the arrangement of the collagen fibrils in a collagenous matrix and direction of ionic flow was studied in vitro at pH7.0 and at 37 degrees, using two types of collagen disks made from sliced bovine Achilles tendon. Disk A and disk B were made from slices cut perpendicular and parallel to the collagen fibrils, respectively. The products on the collagen fibrils were a mixture of OCP and apatite in the both disks, but the relative amounts of apatite and OCP could not be determined. Short plate-like or flake-like OCP crystals grew parallel to the collagen fibrils and ionic flow on the Ca-side of the disk A. On the contrary, ribbon-like or rectangular OCP crystals grew along the collagen fibrils lying on the disk B. Apatite also grew with the same orientation as OCP in the both cases. The oriented and length-wise growth of OCP crystals on the disk B was ascribed to the arrangement of the collagen fibrils in the disk.

Achilles Tendon↗