Progression of hepatocellular carcinoma (HCC) is a stepwise process that proceeds from preneoplastic lesions-including low-grade dysplastic nodules (LGDNs) and high-grade dysplastic nodules (HGDNs)-to advanced HCC. The molecular changes associated with this progression are unclear, however, and the morphological cues thought to distinguish pre-neoplastic lesions from well-differentiated HCC are not universally accepted. To understand the multistep process of hepato-carcinogenesis at the molecular level, we used oligo-nucleotide microarrays to investigate the transcription profiles of 50 hepatocellular nodular lesions ranging from LGDNs to primary HCC (Edmondson grades 1-3). We demonstrated that gene expression profiles can discriminate not only between dysplastic nodules and overt carcinoma but also between different histological grades of HCC via unsupervised hierarchical clustering with 10,376 genes. We identified 3,084 grade-associated genes, correlated with tumor progression, using one-way ANOVA and a one-versus-all unpooled t test. H epatocelluar carcinoma (HCC) is one of the most common malignancies worldwide. The chronic hepatitis resulting from infection with hepatitis B virus or hepatitis C virus and exposure to carcinogens such as aflatoxin B1 are known as major risk factors for HCC. 1 Molecular investigations have recently found that genetic alterations of tumor suppressor genes or oncogenes such as p53, ␤-catenin, and AXIN1 might be involved in the progression to HCC, 2-4 but the frequency of these somatic mutations appears to be low in HCCs. Furthermore, it is unclear how these genetic changes reflect the clinical characteristics of the individual tumors. Therefore, the predominant molecular events underlying HCC in most patients remain unknown.Because HCC typically develops in close association with pre-existing cirrhosis, it is widely believed that a liver with cirrhosis may contain pre-neoplastic nodules that are in an intermediate stage between nonneoplastic regenerating nodules and overtly malignant HCC. 5,6 These nod-

The purpose of this study was to identify the major etiological agents responsible for invasive bacterial infections in immunocompetent Korean children. We retrospectively surveyed invasive bacterial infections in immunocompetent children caused by eight major pediatric bacteria, namely Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species that were diagnosed at 18 university hospitals from 1996 to 2005. A total of 768 cases were identified. S. agalactiae (48.1%) and S. aureus (37.2%) were the most common pathogens in infants younger than 3 months. S. agalactiae was a common cause of meningitis (73.0%), bacteremia without localization (34.0%), and arthritis (50%) in this age group. S. pneumoniae (45.3%) and H. influenzae (20.4%) were common in children aged 3 months to 5 yr. S. pneumoniae was a common cause of meningitis (41.6%), bacteremia without localization (40.0%), and bacteremic pneumonia (74.1%) in this age group. S. aureus (50.6%), Salmonella species (16.9%), and S. pneumoniae (16.3%) were common in older children. A significant decline in H. influenzae infections over the last 10 yr was noted. S. agalactiae, S. pneumoniae, and S. aureus are important pathogens responsible for invasive bacterial infections in Korean children.

Thiazole-containing π-conjugated moieties are important structural units in the development of new electronic and photochromic materials. We have developed a Pd-catalyzed syn-hydroarylation reaction of diaryl alkynes with thiazoles that provides access to thiazole-containing triarylethylenes. Pd­(II) complexes derived from Pd(0) species and carboxylic acids facilitated C–H functionalization of the unsubstituted thiazole with high C5 selectivity. The catalytic system was also compatible with other azoles, such as oxazoles and a pyrazole, allowing the stereoselective syntheses of various trisubstituted olefins.

Pd-catalyzed C–H annulation reactions of halo- and aryl-heteroarenes were developed using readily available o-bromobiaryls and o-dibromoaryls, respectively. A variety of five-membered heteroarenes rapidly provided the corresponding phenanthrene-fused heteroarenes, which led to the identification of phenanthro-pyrazole and thiazole as new, stable −2 V redox couples. The flexible syntheses and tunability of the redox potentials of these azole-fused phenanthrenes over a wide range are expected to facilitate their application as redox-active organic functional materials.

No abstract