Hemoglobin-mediated selenium export from red blood cells

On the basis of the fact that selenium from selenite binds to hemoglobin (Hb), we investigated the missing process in the selenium export from red blood cells (RBCs), i.e., the transfer of selenium bound to Hb to RBC membrane proteins. To elucidate the molecular events of the Hb-associated selenium export from RBC, a Hb–Se complex was synthesized from thiol-exchange of Cys-β93 in Hb with penicillamine-substituted glutathione selenotrisulfide, as a model of major metabolic intermediates, and then interactions between the Hb–Se complex and RBC inside-out vesicles (IOVs) were examined. Selenium bound to Hb was transferred to the IOV membrane on the basis of the intrinsic interactions between Hb and the cytoplasmic domains of band 3 protein (CDB3). The observed selenium transfer was inhibited by the pretreatments of IOVs with iodoacetamide and the α-chymotrypsin digestion, indicating that the Hb mediates the selenium transfer to the thiol groups of CDB3. In addition, it was found that deoxygenated Hb, with a high binding affinity for CDB3, more favorably transferred selenium to the IOV membranes than oxygenated Hb, with a low affinity. When selenium export from RBC to the plasma was examined by continuously introducing nitrogen gas, the selenium export rate was promoted with an increase in the rate of deoxygenated Hb. Overall, these data suggested that Hb could possibly play a role in the selenium export from RBC treated with selenite in an oxygen-linked fashion. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Systemic lupus erythematosus associated with primary large cell carcinoma of the lung

The association between systemic lupus erythematosus (SLE) and malignancy has been controversial in the literature. We report a case of lung cancer in a 50-year-old woman with a 4-year history of SLE. She underwent surgery at a pathological stage of T2N2M0, but she eventually died of rapid recurrence of the cancer in the abdomen resulting in massive haemorrhage from the inferior vena cava (IVC). Immunological disorders related to SLE are thought to contribute to rapid progression of the malignancy.     

Metastatic small cell lung cancer causing biliary obstruction

We report a case with metastatic small cell lung cancer which first manifested with biliary obstruction due to metastasis. Prognosis of patients presenting with jaundice due to hepatic parenchyma involvement is thought to be poor. However, the patient was successfully treated with percutaneous transhepatic biliary drainage and combination chemotherapy with reduced dosage. We believe this to be the first such case report, despite the frequency of metastasis to the liver from small cell lung cancer.     

Frequent Detection of Hepatitis C Virus Subtype 3a (HCV-3a) Isolates in Thailand by PCR Using Subtype-Specific Primers

By means of a polymerase chain reaction (PCR) method using subtype-specific primers for hepatitis C virus (HCV) subtypes 1a, 1b, 2a, 2b and 3a, the prevalence of each subtype among HCV isolates in Chiang Mai, Thailand, was determined. HCV-3a appeared to be the most common subtype in blood donors, and was also frequently found in patients with liver disease. HCV-1b, but not HCV-2a or ?2b, was also commonly found in this area, while a considerable percentage of the total HCV isolates still remained unclassifiable by the above methods. Serotype analysis of the HCV isolates using C14-1 and C14-2 recombinant peptides revealed that HCV-3a was likely to carry an antigenic determinant(s) different from those of the major types 1 (HCV-1a and ?1b) and 2 (HCV-2a and ?2b).     

The Dictyostelium developmental cDNA project: generation and analysis of expressed sequence tags from the first-finger stage of development.

In an effort to identify and characterize genes expressed during multicellular development ill Dictyostelium, we have undertaken a cDNA sequencing project. Using size-fractionated subsets of cDNA from the first finger stage, two sets of gridded libraries were constructed for cDNA sequencing. One, library S, consisting of 9984 clones, carries relatively short inserts, and the other, library L, which consists of 8448 clones, has longer inserts. We sequenced all the selected clones in library S from their 3'-ends, and this generated 3093 non-redundant, expressed sequence tags (ESTs). Among them, 246 ESTs hit known Dictyostelium genes and 910 showed significant similarity to genes of Dictyostelium and other organisms. For library L, 1132 clones were randomly sequenced and 471 non-redundant ESTs were obtained. In combination, the ESTs from the two libraries represent approximately 40% of genes expressed in late development, assuming that the non-redundant ESTs correspond to independent genes. They will provide a useful resource for investigating the genetic networks that regulate multicellular development of this organism.