Copper and iron-induced oxidative damage in non-tumor bearing LEC rats

The copper and Iron status in the liver of non-tumor bearing Long-Evans Cinnamon (LEC) rats (average age 17 months) was investigated. A direct quantitation of loosely-bound copper and iron was also investigated by using a chelating agent, nitrilotriacetic acid (NTA-chelatable free copper and iron). Besides the total copper and iron contents, the level of NTA-chelatable free copper was also higher in LEC rats than In LEA rats (P<0.05). But for the free iron level there was no signiflcant difference between the two rat groups (P>0.05). The formation of thiobarbituric acid-reactive substances was higher In LEC rats than In LEA rats (P<0.01). The 4–hydroxy-2–nonenal (HNE)-modified proteins were also clearly demonstrated in LEC rat liver. The copper and iron which produced the most important effect In the process of oxidative damage in LEC rats could not be distinguished. Even though free copper, which could induce free radical injuries, was increased in LEC rats, neither tumor-induction nor preneo-plastic lesions in the experimental LEC rats were observed. Therefore it is speculated that the elevation of a free iron is another important factor. Copper and iron, both important translation metals In the body, may participate In the Induction of DNA damage and oncogenesls     

Immunoelectron microscopic localization of carcinoembryonic antigen in gastric adenocarcinoma cell lines

The distribution of carcinoembryonic antigen (CEA) in human gastric adenocarcinoma cell lines (HPE-GAC-3 cells and HPE-GAC-2 cells) was determined immunohistochemically by indirect peroxidase-labeled antibody method at the light and electron microscopic levels. In GAC-3 cells that proliferated as non-adherent single cells, CEA was located in the perinuclear spaces, the endoplasmic reticulum, Golgi apparatus, vesicles, multivesicular body (MVB) and entire plasma membrane. Membrane CEA was shown to be internalized into MVB in GAC-3 cells. In GAC-2 cells that form an acinus, CEA was predominantly present along the microvilli of the lumina) surface and in glycocalyceal bodies, the vesicles which bud from the microvilli into the lumen. These results suggest that in poorly differentiated cancer cells CEA is transported over the entire cell surface, retained on the membrane and accumulated Into the cell by way of the MVB, but in well differentiated cancer cells the newly synthesized CEA is rapidly and predominantly transported to the luminal surface and rapidly released from the membrane into the lumen by way of the glycocalyceal body.     

Otx1 function overlaps with Otx2 in development of mouse forebrain and midbrain

Background: We previously reported that the homozygous mutation of Otx2 gene, a mouse cognate of the Drosophila head gap gene orthodenticle , causes failure in the development of the rostral head anterior to rhombomere 3, which may correspond to earlier Otx2 expression in cells destined for the anterior mesoendoderm. At the same time, the Otx2 heterozygous mutation displayed a phenotype characterized as otocephaly, probably related to expression in the anterior neuroectoderm at the subsequent pharyngula stage. Defects were characteristic in the most anterior and posterior regions of Otx2 expression where Otx1 , another mouse cognate of orthodenticle , is not or weakly expressed. They were not found in the region where Otx1 is expressed.
Results: In the present work, Otx1 null mutant mice were generated by gene targeting in embryonic stem cells. No defects were apparent in the regionalization of the early embryonic rostral brain. The newborn brain defects were subtle and most likely related to later Otx1 -unique expression. Otx1 and Otx2 double heterozygous mutant brains, however, exhibited marked defects throughout the fore- and midbrains, where defects were not apparent with a single mutation alone.
Conclusions: Otx1 and Otx2 play synergistic roles in the development of the forebrain and midbrain where both genes are expressed.     

Serotype-specific amplification of Rickettsia tsutsugamushi DNA by nested polymerase chain reaction.

Polymerase chain reaction (PCR) with nested primer pairs was used to diagnose scrub typhus and identify the Rickettsia tsutsugamushi serotype. The primer pairs used for PCR were designed on the basis of the nucleotide sequence of the gene that encodes the 56-kDa antigen. Serotype-specific primers were used in the second PCR amplification. Five serovariants, the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of R. tsutsugamushi, were identified by nested PCR. In addition, the serotype identified by PCR with DNA from blood clots was the same as that of the strain isolated from five patients with scrub typhus. These findings indicate that this method is useful for diagnosis and identification of the rickettsial serotype in infected patients.     

T-cell-specific expression of kinase-defective Eph-family receptor protein, EphB6 in normal as well as transformed hematopoietic cells

Although most kinase-defective growth factor receptor proteins are associated with pathogenic conditions, a kinase-defective Eph-family receptor protein, EphB6, is expressed in normal human tissues. We generated monoclonal antibodies specific for human EphB6 to characterize its expression on human hematopoietic cells. A very small population of normal human peripheral white blood cells (0.57 +/- 0.07%, n = 12) expressed EphB6. The EphB6-positive cells were CD2+, CD7+, CD3+ and CD4+ or CD8+ lymphocytes, but they did not express CD19 or CD11b. In human bone marrow, only 1.5 +/- 0.19% of lymphocytes expressed EphB6. Compared with the expression in peripheral lymphocytes, prominent expression of EphB6 protein was demonstrated in CD4+CD8+ double-positive mouse thymocytes. The T-cell lineage-specific expression was strictly conserved in human leukemia/lymphoma cells. Among T-cell-derived leukemia cells, the expression level of EphB6 seemed to decrease with maturation of the cells. These results suggest that EphB6 expression is regulated in T-cell development.     

Protective role of heme oxygenase-1 in renal ischemia

Oxidative stress, which has been implicated in the pathogenesis of ischemic renal injury, degrades heme proteins, such as cytochrome P450, and causes the elevation in the level of cellular free heme, which can catalyze the formation of reactive oxygen species. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme degradation, is induced not only by its substrate, heme, but also by oxidative stress. In various models of oxidative tissue injuries, the induction of HO-1 confers protection on tissues from further damages by removing the prooxidant heme, or by virtue of the antioxidative, antiinflammatory, and/or antiapoptotic actions of one or more of the three products, i.e., carbon monoxide, biliverdin IXalpha, and iron by HO reaction. In contrast, the abrogation of HO-1 induction, or chemical inhibition of HO activity, abolishes its beneficial effect on the protection of tissues from oxidative damages. In this article, we review the protective role of HO-1 in renal ischemic injury, and its potential therapeutic applications. In addition, we summarize recent findings in the regulatory mechanism of ho-1 gene expression.     

General Pathology Of Kawasaki Disease

Systemic pathological alterations were studied in thirty-seven autopsied patients with Kawasaki disease. Systemic vasculitis was the most characteristic pathological finding and was present in all the patients. In addition to the vasculitis, there was a high incidence of inflammatory lesions in various organs and tissues: in the heart, endocarditis, myocarditis, and pericarditis; in the digestive system, stomatitis, sialoduct-adenitis, catarrhal enteritis, hepatitis, cholangitis, pancreatitis, and pancreas ductitis; in the respiratory system, bronchitis and segmental interstitial pneumonia; in the urinary system, focal interstitial nephritis, cystitis, and prostatitis; in the nervous system, aseptic leptomeningitis, choriomeningitis, ganglionitis, and neuritis; in the hematopoietic system, lymphadenitis, splenitis, and thymitis. Dermatitis, panniculitis or myositis were also observed in some patients. Therefore, Kawasaki disease is a systemic inflammatory disease which mainly affects the cardiovascular system. These systemic inflammatory lesions are considered to correspond to the variegated clinical manifestaitions. The relationship between Kawasaki disease and infantile polyarteritis nodosa (IPN) were discussed, based on the clinicopathological characteristics.     

The AMeX method: a multipurpose tissue-processing and paraffin-embedding method. III. Extraction and purification of RNA and application to slot-blot hybridization analysis.

RNA was extracted from tissues processed by a new fixation and paraffin-embedding method (the AMeX method) and examined by Northern blot analysis and slot-blot analysis. The RNA extraction method for AMeX-processed tissue sections after the deparaffinization step was the same as that for fresh materials. The total amount of cellular RNA extracted from AMeX-processed mouse liver tissue was slightly less than that extracted from fresh tissue. In tissues of malignant lymphoma, the total amount of cellular RNA extracted from 25 sections each 20 microns thick was about 1.6-1.8 micrograms/mm2, regardless of the histological subtype and period of storage. The extracted RNA was moderately degraded, and usually could not be used for Northern blot hybridization analysis. The intensity of ethidium bromide staining and the hybridization signals of RNA extracted from AMeX-processed tissues were usually reduced in comparison with RNA from fresh material, but specific signals could be detected by slot-blot hybridization analysis. We have demonstrated previously that the AMeX method preserves high-molecular-weight DNA and various antigens. Since the present study showed that information on mRNA can be obtained from AMeX-processed tissue, the versatility and usefulness of this method were further proven.     

Malignant phyllodes tumour with a noninvasive ductal carcinoma component

 A malignant phyllodes tumour with a noninvasive ductal carcinoma component is reported. The patient was an 80-year-old Japanese woman with a breast tumour detected by routine physical examination. A simple mastectomy was performed. The excised tumour was 10.5×9.4×5.4 cm in size and bulged into the skin with ulceration. The macroscopic appearance was that of a phyllodes tumour. Histologically the tumour consisted mainly of stromal components with a leaf-like structure lined by atypical ductal epithelium. The epithelial component showed gradual evolution to intraductal papillary carcinoma in a few areas. The stromal component was composed mainly of fibrosarcoma with areas of osteosarcoma and rhabdomyosarcoma. Neither stromal invasion of intraductal carcinoma nor transition between the stromal and epithelial elements was seen. Three months after the operation, death occurred, with multiple pulmonary and subcutaneous metastases. This case probably represents malignant change in both the stromal and the epithelial components of a phyllodes tumour. Since the two elements were independent, the possibility that a phyllodes tumour may be one of the origins of true carcinosarcoma is raised. Received: 11 March 1997 / Accepted: 5 May 1997