Establishment of a new method, transcription–reverse transcription concerted reaction, for detection of plasma hnRNP B1 mRNA, a biomarker of lung cancer

Purpose  Development of an early detection marker is one of the most important strategies for improving overall prognosis in lung cancer patients. We previously reported that hnRNP B1––an RNA binding protein––is overexpressed in lung cancer tissue from the early stage of cancer, and found that hnRNP B1 mRNA is detectable in the plasma of lung cancer patients using real-time RT-PCR. The purpose of this study was to establish a quick and simple method for detecting plasma hnRNP B1mRNA for use in screening for lung cancer. Methods  TRC, a homogenous method for fluorescence real-time monitoring of isothermal RNA amplification using intercalation activating fluorescence DNA probe, was used to detect plasma hnRNP B1 mRNA. Results  The detection limit of hnRNP B1 mRNA by TRC using synthetic control RNA or total RNA derived from a lung cancer cell line was 25 or 8.65 × 10² copies, respectively. Using total RNA extracted from 600 μl of plasma, we detected hnRNP B1 mRNA in 39.1% (9/23) of lung cancer patients, with levels ranging from 1.9 to 19,045.5 copies/100 ng RNA, and in 5.2% (5/97) of healthy volunteers. Copy numbers were not associated with age, gender, smoking status, or histological type of cancer. TRC could detect 10³ copies of hnRNP B1 mRNA in 10 min. Conclusion  Detection of plasma hnRNP B1 mRNA by TRC is a quick, easy, and non-invasive method suitable for lung cancer screening.     

CD25+CD4+ T cells contribute to the control of memory CD8+ T cells

Previously we demonstrated that IL-15 and IL-2 control the number of memory CD8+ T cells in mice. IL-15 induces, and IL-2 suppresses the division of these cells. Here we show that CD25+CD4+ regulatory T cells play an important role in the IL-2-mediated control of memory phenotype CD8+ T cell number. In animals, the numbers of CD25+CD4+ T cells were inversely correlated with the numbers of memory phenotype CD8+ T cells with age. Treatment with anti-IL-2 caused CD25+CD4+ T cells to disappear and, concurrently, increased the numbers of memory phenotype CD8+ T cells. This increase in the numbers of CD8+ memory phenotype T cells was not manifest in animals lacking CD4+ cells. Importantly, adoptive transfer of CD25+CD4+ T cells significantly reduced division of memory phenotype CD8+ T cells. Thus, we conclude that CD25+CD4+ T cells are involved in the IL-2-mediated inhibition of memory CD8+ T cell division and that IL-2 controls memory phenotype CD8+ T cell numbers at least in part through maintenance of the CD25+CD4+ T cell population.     

MOLECULAR IDENTIFICATION OF Bartonella henselae IN A SERONEGATIVE CAT SCRATCH DISEASE PATIENT WITH AIDS IN RIO DE JANEIRO, BRAZIL

Bartonella henselae is associated with a wide spectrum of clinical manifestations, including cat scratch disease, endocarditis and meningoencephalitis, in immunocompetent and immunocompromised patients. We report the first molecularly confirmed case of B. henselae infection in an AIDS patient in state of Rio de Janeiro, Brazil. Although DNA sequence of B. henselae has been detected by polymerase chain reaction in a lymph node biopsy, acute and convalescent sera were nonreactive.     

Biliary adenofibroma with ominous features of imminent malignant changes

Biliary adenofibroma (BAF) is a rare, benign liver tumor. Herein, we report a case of BAF with histological features of imminent malignant changes. Ultrasound and CT revealed a solid 2.5-cm mass in the right liver lobe. The patient was asymptomatic and had no past medical history including liver disease. A general examination that included the abdomen and the laboratory data were normal. Because of the increase of its size, this tumor was surgically resected. Grossly, a 3.5-cm nodular mass abutted on the hepatic capsule was found, and its cut surface showed a well-circumscribed, whitish, and firm lesion that showed microcystic changes in the periphery and solid changes in the central parts. Histologically, the tumor showed a proliferation of tubulocystic structures embedded in a fibrous stroma. Microcysts were prevalent in the periphery, while tubular components with abundant fibrous stroma were in the central parts. The tubules were variably dilated and branched. This case closely resembled the previously reported cases of BAF, except that there were complicated papillary projections with fine fibrovascular cores in some of the microcysts and that the epithelial component in papillary projections showed dysplastic changes and increased cellular proliferative activities, implicating ominous features of imminent malignant changes. These dysplastic and papillary changes may be an intermediate lesion leading to malignancy, which have occasionally been reported in BAF.     

Intraductal polypoid growth variant of pancreatic acinar cell carcinoma metastasizing to the intrahepatic bile duct 6 years after surgery: A case report and literature review

We present the first reported case of intraductal polypoid growth (IPG) variant of pancreatic acinar cell carcinoma (ACC) metastasizing to the intrahepatic bile duct. A 58-year-old Japanese woman had previously presented with obstructive jaundice and a 7.0 cm mass in the pancreatic head. She underwent biliary drainage for 2 months followed by pancreatectomy. Histological examination revealed a carcinoma with acinar pattern, immunohistochemically positive for trypsin, and acinar cell carcinoma was diagnosed. IPGs were prominent in the main pancreatic duct and its tributaries, extending into the intrapancreatic bile duct with tumor casts in the lumen. Imaging examinations 6 years later revealed a growing lesion within the intrahepatic bile duct. Needle biopsy examination suggested metastasis of ACC, and she underwent chemoradiation therapy and partial hepatectomy. Histological examination demonstrated ACC confined to the intrahepatic bile duct. The localization of metastasis and slow growth may indicate indolent biologic behavior of the IPG variant.