Ecological and genetic analyses of the complete genomes of Culex flavivirus strains isolated from Culex tritaeniorhynchus and Culex pipiens (Diptera: Culicidae) group mosquitoes.

Culex flavivirus (CxFV) is an insect-specific flavivirus that was first reported in 2007 in Japan. CxFV strains were isolated from Culex tritaeniorhynchus Giles and Culex pipiens L. group mosquitoes and genetically characterized in Toyama Prefecture, Japan, from 2004 to 2009, to reveal host specificity, mode of transmission, and seasonal and geographical distribution. The minimum infection rate (MIR) of CxFV within Cx. tritaeniorhynchus populations was 0.3 and much lower than that within Cx. pipiens group (17.9). The complete genome sequences of 11 CxFV isolates (four from Cx. tritaeniorhynchus and seven from Cx. pipiens group) consisted of 10,835-10,837 nucleotides. When these 11 isolates and five reference strains (NIID-21-2 and Tokyo strains from Japan, Iowa07 and HOU24518 strains from the United States, H0901 strain from China) were compared, there were 95.2-99.2% nucleotide and 98.1-99.8% amino acid identities. Phylogenetic analysis showed that the 11 isolates were divided into four clusters. One cluster consisted of five isolates from Cx. pipiens group and Cx. tritaeniorhynchus from one site and their nucleotide sequences almost completely matched. One cluster consisted of an isolate with a unique sequence from a Cx. pipiens group mosquito captured in an aircraft from Taiwan, suggesting that it was introduced from abroad. CxFV strains were divided into several groups according to countries when nucleotide sequences of CxFV available in GenBank and 11 Toyama isolates were compared. These results suggest that CxFV is maintained in nature among Culex mosquitoes in a mosquito habitat-specific but not a species-specific manner.

1C5 antigen: cancer-associated protein expressed by cervical adenocarcinomas and beta-casein.

The monoclonal antibody 1C5 reacts with an antigenic determinant present in 90% of the cases of adenocarcinoma of the uterine cervix. The antigen defined by the 1C5 antibody exhibits immunological characteristics similar to those of skim milk (bovine buttermilk). 1C5-defined antigen obtained from tumor extract and skim milk binds specifically to wheat germ agglutinin (WGA) lectin. The 1C5-defined antigenic activity of a WGA lectin-bound fraction was eluted at 0.7-0.8 M NaCl off a Mono Q column. Use of an inhibition assay and a dot immunobinding assay revealed that the antigenic epitope defined by the 1C5 MoAb from skim milk exists within the first 28 amino acids of the beta-casein peptide.

Demonstration of the interaction between the CD23 molecule and the galactose residue of glycoproteins.

The CD23 molecule is a low-affinity receptor for IgE and has a marked homology in amino acid sequence with C-type animal lectins, including asialoglycoprotein receptor. We tested whether the CD23 antigen can indeed interact with the sugar chain of glycoproteins. Detergent extract of the membrane component from Epstein-Barr Virus (EBV)-transformed human B-cell line, L-KT9 cells, was incubated with asialofetuin (ASF)-coupled Sepharose, and bound proteins were effectively eluted by 0.3 M lactose or galactose which were among the competitive sugars tested. In this eluate, the CD23 molecule was detected by an immunoblotting technique. Because fetuin has both an N- and O-type sugar chain on the molecule, we tested which type of sugar chain can interact with CD23. The CD23 molecule interacted with asialocasein having a sugar chain with the Gal-GalNAc structure with asialobovine submaxillary mucin having the GalNAc structure, and also with ASF; however, it faintly interacted with ASF after removal of the O-type sugar chain by beta-elimination. These results showed that the CD23 molecule can, indeed, interact with the galactose residue, especially with the Gal-GalNAc rather than the Gal-GlcNAc structure of the terminal sugar chain of glycoproteins.

Morphology of adenocarcinoma in situ and microinvasive adenocarcinoma of the uterine cervix. A cytologic and ultrastructural study.

Adenocarcinoma in situ (AIS) and microinvasive adenocarcinoma of the uterine cervix and normal endocervical columnar epithelium were studied by cytology, morphometry and electron microscopy to identify differentiating features and to ascertain the cellular origin of cervical adenocarcinoma. Smears from AIS showed the characteristic cytology, consisting of glandular rosettes, palisading and crowded sheets; most nuclei had a relatively uniform oval shape. Smears from microinvasive adenocarcinoma showed more crowded sheets, with enlarged, round and irregular-shaped nuclei and prominent oval nucleoli. These nuclear features were confirmed by the morphometric results. Ultrastructurally, reserve cells in the normal tissues contained tonofibers and secretory granules and showed squamous and adenomatous features. The ultrastructural features of microinvasive adenocarcinoma were similar to those of well-differentiated invasive adenocarcinoma. The cells from both contained tonofibers and secretory granules. These findings suggested that the reserve cell is the cell of origin for cervical adenocarcinoma.