Surface photografting, 2. Modification of polypropylene film surface by graft polymerization of acrylamide

The hydrophobic surface of oriented poly(propylene) film (OPP) was modified to a hydrophilic one by a novel photo-grafting procedure using acrylamide (AM) as monomer. A deoxygenated acetone solution containing AM and benzophenone (BP) or other sensitizers was brought into contact with OPP film and the reaction system was photoirradiated from the other side of the polymer film. Within a few minutes, surface photo-grafting resulted. The influences of solvent, sensitizer, and additives revealed that the graft polymerization was initiated by hydrogen abstraction from the polymer surface by the triplet excited state of the sensitizer. IR Spectroscopy as well as ESCA measurements confirmed that the graft polymerization occurred on the film surface. The wettability of the grafted OPP film is discussed and correlated with the relative amount of surface grafting. The contact angle of untreated OPP film to water (101°) decreased to ≈40° after surface photografting. The drastic change of surface properties makes the practical application of the present technique feasible.     

Immunohistochemical study on tissue transglutaminase and copper-zinc superoxide dismutase in human myocardium: Its relevance to apoptosis detected by the nick end labelling method

The influence of free radicals on apoptosis was studied in the human heart; 45 autopsy cases were examined by the nick end labelling method (NELM) that detects DNA fragmentation. Immunostaining for copper-zinc superoxide dismutase (CuZn-SOD) and tissue transglutaminase (tTG) induced frequently during apoptosis were also studied. Positive immunoreaction for tTG was detected in mucinous degeneration of myocardial cells; these same cells were also positive for CuZn-SOD but negative for NELM. Myocardial cells showing basophilic alterations after haematoxylin and eosin staining were also positive for CuZn-SOD but negative for the other markers examined. Positive nuclear reaction by NELM was only observed in myocardial cells showing contraction band necrosis or irregularly shaped nuclei surrounding recent or long-standing infarcted foci. In these the other two markers were negative. Since mucinous degeneration lacks the distinguishing morphological features of apoptosis, immunoreactive tTG in this lesion may not imply that the cells are undergoing apoptosis. tTG can be induced in non-apoptotic conditions and may not be involved in apoptosis induced by infarction. Histological disassociation between CuZn-SOD expression and apoptosis suggests the possibility of a cytoprotective role played by endogenous CuZn-SOD against free radical generation in the human heart.     

Arpp,a new homolog of carp,is preferentially expressed in type 1 skeletal muscle fibers and is markedly induced by denervation

In this study, we isolated and characterized a murine counterpart of the human Arpp (hArpp) gene. Sequence analysis revealed that the murine Arpp (mArpp) gene is almost identical to the Ankrd2 gene, which has recently been isolated as a mouse gene induced in stretched skeletal muscle. The mArpp gene encodes a protein of 332 amino acids that contains four well-conserved ankyrin-repeat domains in the central portion of the protein. The amino acid sequence of mArpp protein (mArpp) is highly homologous to that of mouse cardiac-restricted ankyrin-repeat protein (Carp), which is proposed to be a putative genetic marker for cardiac hypertrophy. Immunohistochemical analysis revealed that mArpp is preferentially expressed in type 1 skeletal muscle fibers, and that mArpp is localized in both the nucleus and the sarcomeric I-band of muscle fibers, suggesting that Arpp may function as a nuclear and sarcomeric protein. Furthermore, mArpp was also expressed in neurons of the cerebellum and cerebrum, the islets of Langerhans in the pancreas, and the esophageal epithelium, suggesting that mArpp may play a functional physiologic role in brain, pancreas, and esophagus as well as in type 1 muscle fibers. Interestingly, although mArpp was localized in both nucleus and cytoplasm in neurons, its localization was restricted to nucleus in pancreas and esophagus, suggesting that intracellular localization of mArpp is regulated in a tissue-specific manner. Furthermore, we found that mArpp- and Carp-expression in skeletal muscle were markedly up-regulated after denervation. Although the elevated expression level of Carp was kept only for two weeks after denervation, that of Arpp was kept at least for 4 weeks, suggesting that mArpp and Carp may play distinct functional roles in denervated skeletal muscle.     

Exogenous antigens are processed through the endoplasmic reticulum-associated degradation (ERAD) in cross-presentation by dendritic cells

Antigen cross-presentation is critical in infectious and tumor immunity where cytotoxic T lymphocytes are induced by dendritic cells specifically equipped with cellular machineries to present exogenous antigens with major histocompatibility complex (MHC) class I molecules. To examine molecular mechanisms of antigen cross-presentation, we employed as a model system a murine dendritic cell line DC2.4 capable of presenting soluble antigens such as ovalbumin (OVA) with MHC class I. Here, we demonstrate that exogenously added OVA is accumulated in the endoplasmic reticulum (ER) and late endosomes followed by retrograde transport to the cytoplasm through the Sec61 transporter complexes, and that CHIP functions as an E3 ubiquitin-ligase for OVA degradation by proteasomes. This mechanism is essentially the same as that known as the ER-associated degradation (ERAD) in the quality control of secretary and membrane proteins.     

Abnormal distribution of cathepsins in the brain of patients with Alzheimer's disease

Formalin-fixed paraffin-embedded hippocampal sections of brains with early-onset and late-onset Alzheimer's disease were studied immunohistochemically with antisera against cathepsin D and cathepsin B. In addition to the staining of neuronal perikarya, some of the senile plaques visualized by Bielshowsky silver staining and some of reactive astrocytes were positively stained with the antisera against cathepsin D and cathepsin B in brains with Alzheimer's disease. Abnormal localization of cathepsin D and cathepsin B immunoreactivity in neuronal perikarya was observed in brains with early-onset Alzheimer's disease. These findings demonstrate that the distribution of lysosomal proteases was altered in brains with Alzheimer's disease, suggesting the primary and/or secondary involvement of the lysosomal proteases in the pathological process of Alzheimer's disease.     

NECROTIZING MYOPATHY AS A REMOTE EFFECT OF GASTRIC CANCER ACCOMPANIED WITH HASHIMOTO'S THYROIDITIS

An autopsy case of a 74-year-old male who had shown clinically hypothyroidism due to chronic atrophic thyroiditis (Hashimoto's thyroiditis), and pathologically necrotizing myopathy as a remote effect of gastric cancer was reported.
Morphological features of this necrotizing myopathy was those of carcinomatous myopathy rather than those of hypothyroid or diabetic myopathy.
As for the pathogenesis of the necrotizing myopathy (as a Group IV of polymyositis of Walton and Adams), the malignancy might have played an important role as a trigger of the secondary immunological abnormality upon a pre-exizting longstanding immune disorder of Hashimoto's thyroiditis. Pseudomembranous colitis, which was thought to be related to antibiotics (Lincomycin), was also briefly discussed.     

IMMUNOELECTRON MICROSCOPIC LOCALIZATION OF THYROGLOBULIN IN HUMAN FOLLICULAR ADENOMA

An electron microscopic immunohistochemical localization of thyroglobulin (TG) using PAP methods has been made in 15 cases of cold follicular adenoma. All cases of follicular adenoma showed organ specific functions such as synthesis, storage, reabsorption, and hydrolysis of thyroglobulin except for an area composed of follicular cells with trabecular arrangement. Immuno-reaction product for TG was precisely demonstrated in follicular lumina, subapical vesicles and reabsorbed colloid droplets. The reaction product observed in the follicular lumen was clearly demarcated from the cytoplasm of the follicular cells by the apical plasma membrane. The subapical vesicles ranging approximately from 50 mμ to 300 mμ in diameter were rarely observed in follicular adenoma and some of them fused with the reabsorbed colloid droplets. The reabsorbed colloid droplets usually had the intense reaction product and hydrolyzed colloid droplets had a vacuole containing floccular low electron dense materials. There is no reaction product in rough endoplasmic reticulum and Golgi complexes.     

Cardiac ankyrin repeat protein is preferentially induced in atrophic myofibers of congenital myopathy and spinal muscular atrophy

Cardiac ankyrin repeat protein (CARP), which is structurally characterized by the presence of four ankyrin repeat motifs in its central region, is believed to be localized in the nucleus and to participate in the regulation of cardiac-specific gene expression in cardiomyocytes. However, we recently found that CARP was induced in skeletal muscle by denervation, leading us to speculate that CARP may be induced under some pathological conditions. In the present study, we immunohistochemically analyzed the expression of CARP in 11 cases of spinal muscular atrophy (SMA) and 14 cases of congenital myopathy. In SMA, CARP was expressed selectively in severely atrophic myofibers, suggesting that CARP expression may reflect the status of muscle atrophy. Furthermore, in the congenital myopathies, the expression patterns of CARP were distinct among the subtypes, which included nemaline myopathy, myotubular myopathy, central core disease, and congenital fiber type disproportion. Although CARP was preferentially expressed in severely damaged myofibers in nemaline myopathy, it was not detected in central core disease. These findings suggest that immunohistochemical evaluation of CARP may be helpful in the diagnosis of SMA and the congenital myopathies.