Human cytomegalovirus infection in foci of Langerhans cell histiocytosis

 Langerhans cell histiocytosis (LCH) has been thought to be a disorder of immune regulation, and increasingly, evidence showing that the tissue damage in LCH involves lymphokines and pro-inflammatory cytokines is reported. We detected human cytomegalovirus (HCMV)-DNA in LCH cells in the foci of LCH lesions by immunohistochemistry, in situ hybridization and PCR. HCMV was detected in the nuclei and/or cytoplasm of LCH cells in 9 of 27 LCH cases by immunostaining. HCMV was probably an early antigen. In situ hybridization revealed signals for HCMV-DNA only in the nuclei of LCH cells in 10 of the 27 LCH cases. PCR analysis was performed in 20 of the LCH cases, and HCMV-DNA was detected in 7 of these. All 7 positive cases were also positive for HCMV by ISH and IHC. These findings suggested that early phase infection or reactivation of HCMV occurred in the LCH lesions. HCMV infection may be accompanied by impaired cytokine production. Our study also suggested a relationship between HCMV infection and expression of TNFα. In tissues affected by LCH, dermatopathic lymphadenopathy or malignant fibrous histiocytoma and in normal tissues no signals for Epstein-Barr virus-RNA were detected. These findings suggest that in some cases LCH is associated with HCMV infection. Received: 24 November 1998 / Accepted: 24 April 1998     

Comparison of mutagenic potentials and mutation spectra of benzene metabolites using supF shuttle vectors in human cells

Benzene is a human leukemogen and the metabolites are thought to be deeply involved in benzene leukemogenesis. In a previous study we reported the molecular analysis of p-benzoquinone (p-BQ) mutagenesis by using a supF shuttle vector plasmid and here we report the mutagenesis of the other metabolites, hydroquinone (HQ) and trans, trans-muconaldehyde (MUC). HQ is a precursor of p-BQ and MUC is produced by a ring-opening metabolic pathway. We found that the HQ redox cycle produced an oxidative lesion in plasmid DNA and significant differences among the mutagenic potentials of MUC, HQ and p-BQ. HQ has stronger mutagenicity than the others. It is about 20 and 600 times stronger than p-BQ and MUC, respectively. Furthermore, we found notable differences in each mutational feature. The MUC mutational type was characterized by a high frequency of tandem base substitutions that could be due to crosslinks produced by its aldehyde moieties, while HQ was characterized by frequent deletion. This HQ feature is the same as in vivo benezene mutagenesis of Big Blue mice reported by Provost et al. in 1996 and is also quite similar to a hydrogen peroxide mutational feature. Therefore, we presume that HQ and reactive oxygen species may play an important role in benzene carcinogenesis.     

Preparation of a protein micro-array using a photo-reactive polymer for a cell-adhesion assay

A protein micro-array, called a "cell chip" was constructed by using a photo-reactive polymer for a cell-adhesion assay. Various amounts of albumin or fibronectin were covalently immobilized on a polystyrene dish using a micro-spotter with a dip pen. First, poly(acrylic acid) carrying azidophenyl groups was synthesized as the photo-reactive polymer. Secondly, the aqueous solution of a photo-reactive polymer (several nanoliters) was cast using the dip pen of the micro-spotter and dried in air. Subsequently, aqueous solutions of proteins were cast on the same place using the micro-spotter. After drying, the dish was irradiated with ultraviolet light. Finally, the immobilization was confirmed by staining with a dye. The immobilization was stable even after washing with Tween-20. The protein-immobilized area depended on the manipulation of the micro-spotter and the size of the dip pen. Subsequently, cell adhesion on the photo-immobilized protein micro-array was investigated. The adhesion behavior of cells depended on the kind of immobilized proteins and the kind of cells. The protein micro-array will be useful for cell diagnosis and for the selection of biomaterials to regulate cell behavior.     

Effects of suramin on metastatic ability,proliferation, and production of urokinase-type plasminogen activator and plasminogen activator inhibitor type 2 in human renal cell carcinoma cell line SN12C-PM6

Effects of suramin, a polysulfonated naphthylurea compound, on metastatic ability, proliferation, and production of plasminogen activators and plasminogen activator inhibitors were studied using the highly metastatic human renal cell carcinoma cell line, SN12C-PM6. After renal subscapular implantation of tumor cells in nude mice, suramin significantly inhibited metastasis of tumor cells to the lungs and liver. In vitro growth of tumour cells was inhibited by suramin in a dose-dependent manner, at relatively low doses (ID₅₀ = 105 µg/ml). Plasminogen activator inhibitor type 2 (PAI-2) production by tumor cells was enhanced by suramin (100 µg/ml), whereas urokinase-type plasminogen activator (uPA) production was suppressed. Thus, the increase in PAI-2 and the decrease in uPA production correlated with the inhibitory effects on tumour growth and metastasis by suramin. Therefore suramin may be beneficial for the treatment of patients with an early stage of renal cancer with potential risk of metastasis.     

Investigation of albumin synthesis in rat livers during the perinatal period using immunocytochemistry andin situ hybridization

The immunoreactivity of albumin (ALB) was observed in the hepatocytes of fetal rats on day 18 of gestation, and was especially observable in immature rough endoplasmic reticulum (rER) and Golgi apparatus (GA); by then, a small amount of silver grains of ALB mRNA could already be detected. Just after birth, immunoreactivity of ALB could be observed in fine granules or diffusely in all hepatocytes, and was present in rER and GA. One week after birth immunoreactivity of ALB was observed in all hepatocytes and was visible in developed rER and GA; the grains of ALB mRNA were present in all hepatocytes.     

Studies on elementary reactions in the polymerization of 1,2-epoxycyclohexane with organozinc compounds as initiators

1,2-Epoxycyclohexane ( 1 ) was found to behave differently from propylene oxide (PO) in polymerization reactions with organozinc compounds as initiators. A chair-type complex, [Zn-MP]_2,2, is the only compound that shows high catalytic activity for both polymerization of 1 and PO, following an anionic coordination mechanism. On the other hand, the polymerization of 1 with ZnEt₂ or (EtZnOMe)₄ as initiator proceeds according to a cationic mechanism. Cationic polymerization of 1 with ZnEt₂ has two modes of termination reaction resulting in the formation of terminal units containing vinyl ether and allyl ether moieties. The initiation and propagation mechanism of 1 by [Zn-MP]_2;2 is similar to that of PO, but chain transfer reaction takes place in the polymerization of 1 owing to the low stability of the growing chain end. By using [Zn-MP]_2,2 as initiator, it was possible to prepare a block copolymer consisting of an isotactic sequence of monomeric units of PO and a syndiotactic sequence of monomeric units of 1 .     

Giant inflammatory polyposis of the descending colon associated with a Crohn's disease-like colitis

A case of giant inflammatory polyposis associated with a localized inflammatory bowel disease of the descending colon in a 49-year-old man is presented. Lower abdominal distension rapidly appeared without any previous history of gastrointestinal disease. Two months later, he underwent a left hemicolectomy. Postoperative recovery was complete and he remains in good health more than 2 years later. The resected colon showed a giant and bizarre polyposis measuring up to 12 cm in length and 2 cm in height and covering the entire circumference of the colon. The polyposis consisted of narrow worm- or noodle-like polyps that bridged over the irregularly shaped ulcers, which sometimes extended into muscularis propria. Although longitudinal ulcers or scars, stricture, and a cobble-stone appearance were not observed, transmural inflammation and deep fissures were found in the interpolypoid area. From these findings, this case seems to be more similar to Crohn's disease than other inflammatory bowel diseases.