Chromophobe renal cell carcinoma

Chromophobe renal cell carcinoma (RCC) is a recently established subtype of RCC, which has rarely been reported in Japan. In this communication, the authors report two Japanese cases of chromophobe RCC together with the immunohistochemical findings. The tumors were composed of sheets and cribriform glands formed by tumor cells with cloudy and reticular cytoplasm. Ultrastructurally, the cytoplasm was filled with numerous microvesicles. The tumor cells were positive for cytokeratin, epithelial membrane antigen, and Tamm-Horsfall protein. Occasionally, LeuM1-positive cells were also noted. Vimentin was negative, unlike the usual RCC. Reactivity for peanut agglutinin was more frequent than that to Lotus tetragonolobus agglutinin. The results of this study suggest that the tumor cellq possessed phenotypes similar to the distal nephron rather than to the proximal tubular cells.     

Monoclonal antibodies to a CD4 peptide derivative which includes the region corresponding to an immunoglobulin CDR3: evidence of the involvement of pre-CDR3-related region in HIV-1 and host cell interaction.

A CD4 peptide of amino acid residues 68-130 [CD4(68-130)], which had the capacities to inhibit HIV-1 replication and HIV-1-induced syncytium formation, was used as an immunogen for the preparation of mAb. The mAbs prepared were classified into at least five types (I-V) in terms of their recognition sites by ELISA using various kinds of smaller CD4 peptides. Among them, the type I mAb no. 35 recognizing amino acid residues 72-84, which lies just before the region corresponding to an immunoglobulin third complementarity-determining region (CDR3), showed the strongest effects in reducing both HIV-1 infection and HIV-1-induced syncytium formation, although a large amount of no. 35 mAb was necessary to reduce such HIV-1 activities compared with those of anti-Leu-3a and OKT4A mAbs which recognize CD4 epitopes near a portion corresponding to an immunoglobulin CDR2. Western blot analysis showed that the reactivities of CD4 molecule in CD4-positive cells or sCD4 molecule with types I-V mAbs were stronger than that with anti-Leu-3a mAb. Flow cytometry showed that no. 35 mAb was faintly reactive with native CD4 molecule on cell surface at the concn showing the inhibitory effects on HIV-1 infection and syncytium formation. In addition, a smaller peptide CD4(66-92), one of the good epitope peptides for no. 35 mAb, also showed strong inhibitory effect on HIV-1 infection as well as a weaker inhibitory effect on syncytium formation. These results suggest that, in addition to the CD4 CDR2-related region, the pre-CDR3-related region is also involved in the early events of the interactions between the host cell and HIV-1.     

Establishment and Characterization of Cell Lines from Human Adenovirus Type 12-induced Murine Tumors Producing Endogenous Virus Particles

Two cell lines designated IC KMS and D KMS were established from human adenovirus type 12 induced tumors of C3Hf/OK mouse. The cell lines retained the characteristics of the original tumor i.e., production of numerous C type and intracisternal A-type particles, integration of Adl2 El region DNA and amplification of the myc gene family. Chromosomal analysis revealed chromosome aberrations in both IC KMS and D KMS cells. The modal chromosome number of IC KMS cells was 54 and that of D-KMS cells was 48. Metacentric chromosomes and mini-chromosomes were found. Trisomy of chromosome 3, 7 and 12 was seen frequently in D KMS cells. Although DNA aneuploidy was revealed by flow cytometry, the DNA indices of these cells showed no relation to the copy number of integrated Adl2 DNA. These cells have been propagated by serial culture during the past 17 months. Production of endogenous virus particles is a unique characteristic of IC KMS and D KMS cells. These cell lines would be useful materials for examining the contribution of Adl2 carcinogenesis to activation of endogenous virus particles, and also the correlation between Adl2 carcinogenesis and cancer related genes. Acta Pathol Jpn 42: 242-248, 1992.     

Ability of polymorphonuclear leukocytes to generate active oxygen species in children with bronchial asthma. Use of chemiluminescence probes with a Cypridina luciferin analog and luminol.

Airway inflammation with polymorphonuclear leukocytes (PMN) may play an important role in bronchial hyperresponsiveness (BHR). PMN generate superoxide anion (O2-) and other oxygen radicals that can damage lung tissue. We investigated the ability of peripheral PMN of children with bronchial asthma and control subjects to generate O2- and other active oxygen species using a 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one, a highly sensitive and specific chemiluminescence (CL) probe for O2-, and luminol-dependent CL. The ability of PMN of subjects with asthma to generate O2- and other active oxygen species was significantly greater than that of PMN of control subjects when stimulated with opsonized zymosan (OZ), phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine. Furthermore, in the same asthmatic children, the generation of O2- and other active oxygen species was significantly higher with attacks than without attacks when PMN were stimulated with OZ. We also demonstrated that O2- generation correlated with the degree of BHR to inhaled histamine. These results suggest that PMN of asthmatic children, especially those with attacks, generate more active oxygen species than that of control subjects and that airway inflammation caused by O2- may be closely related to BHR in subjects with bronchial asthma.     

Genomic alterations in primary cutaneous melanomas detected by metaphase comparative genomic hybridization with laser capture or manual microdissection: 6p gains may predict poor outcome

To clarify the correlation of genomic alterations with clinical and histological features, we performed metaphase comparative genomic hybridization analysis on 20 primary cutaneous melanomas, which were obtained by laser capture or manual microdissection, and 16 melanoma cell lines. There were no differences in the average number of aberrations between acral melanomas (AM) and non-AM, although gains of 5q and 11q13 were more frequent (P=0.05) and 10q loss was less frequent (P=0.01) in AM than in non-AM. Although tumor thickness is considered a measurable estimate of clinical expression, there were no differences in the average number of aberrations among 4 groups, classified by thickness of the tumor. While the majority of aberrations were equally distributed among the 4 groups, 6p gains were found only in the thickest tumors. Patients with 6p or 1q gains had a lower overall survival rate than those without them (P=0.0002 or P=0.013). While gains of 1q, 2q, 3p, 3q, 7q, 20p, and 20q were more frequent in the cell lines than in the primary tumors (P<0.01), losses of 6q, 9p, 10p, and 10q were equally found in both cell lines and primary tumors. The present study showed that chromosomal aberrations had already occurred in the thinner tumors, and that 6p and 1q gains may be a prognostic factor.     

Molecular mechanism for connective tissue destruction by dipeptidyl aminopeptidase IV produced by the periodontal pathogen Porphyromonas gingivalis

Porphyromonas gingivalis is a pathogen associated with adult periodontitis. It produces dipeptidyl aminopeptidase IV (DPPIV), which may act as a virulence factor by contributing to the degradation of connective tissue. We investigated the molecular mechanism by which DPPIV contributes to the destruction of connective tissue. DPPIV itself did not show gelatinase or collagenase activity toward human type I collagen, but it promoted the activity of the host-derived matrix metalloproteinase 2 (MMP-2) (gelatinase) and MMP-1 (collagenase). DPPIV bound to fibronectin and mediated the adhesion of P. gingivalis to fibronectin. Mutant DPPIV with catalytic Ser mutagenized to Ala (DPPSA) did not accelerate the degradation of collagen and gelatin by MMPs but retained fibronectin-binding activity. The adhesion of human gingival fibroblasts and NIH 3T3 cells to fibronectin was inhibited by DPPIV. Strain 4351ADPPSA exhibited an intermediate level of virulence in mice, between that of the strain expressing wild-type DPPIV (4351ADPP) and that of the strain harboring only the plasmid vector (4351AVEC). It is suggested that both activity promoting the degradation of collagen and gelatin and binding to fibronectin are required for full virulence. These results reveal novel biological functions of DPPIV and suggest a pathological role in the progression of periodontitis.     

Characterization of acetate uptake by the colonic epithelial cells of the rat

The characteristics of acetate uptake by colonic epithelial cells of the rat were studied. Clear saturation kinetics of acetate uptake were not observed in these experiments at either 0° C or 30° C. A decrease in the pH of the medium markedly increased the acetate uptake. The activation energy for acetete uptake derived from an Arrhenius plot was about 6.1 kcal/mole. Among the inhibitors tested, no effective inhibition of acetate uptake at 0° C was observer. Metabolic inhibitors severely inhibited transport at 30° C. Inhibition of acetate uptake by other short chain fatty acids, which was non-competitive, was observed. The finding that efflux from the cells was stimulated in the presence of compounds such as pyruvate and bicarbonate supported the notion of a close interrelationship between weak electrolyte transports in vivo. Although the H⁺ gradient across the cell membrane is suggested to be one of the factors determining the uptake rate, it seems difficult to explain all the results in this way.     

Five-year follow-up study of mother-to-child transmission of Helicobacter pylori infection detected by a random amplified polymorphic DNA fingerprinting method

Recent studies have speculated on the possible role of the mother in transmitting Helicobacter pylori infection to their children. In an attempt to either prove or disprove this supposition, we investigated the rates of infection of children born to H. pylori-positive mothers from birth to 5 years of age using serology and the stool antigen test. When infection of the children did occur, the strains from the children were compared to those of their mothers using DNA analysis. Sixty-nine of the 350 pregnant mothers (19.7%) had a positive serology for H. pylori. Fifty-one children underwent serological examinations and stool antigen tests at 4 to 6 days after birth, followed by 1, 3, and 6 months. They were continuously given the stool antigen test at 4- to 6-month intervals until the age of 5 years. Gastric juice samples were collected from the infected children and their mothers for culture and DNA analyses using a random amplified polymorphic DNA fingerprinting method. None of the 51 children acquired H. pylori infection during the first year of life. Of the 44 children enrolled in a 5-year follow-up study, five (11%) acquired H. pylori infection. They acquired the infection at the age of 1 year 2 months, 1 year 3 months, 1 year 6 months, 1 year 8 months, and 4 years 4 months. Random amplified polymorphic DNA fingerprinting confirmed that the strains of the five children exhibited DNA fingerprinting patterns identical to those of their mothers. These findings suggest that mother-to-child transmission is the most probable cause of intrafamilial spread of H. pylori.