An anti-K-ras ribozyme suppresses oncogene expression and cell growth of human pancreatic cancer

Hammerhead ribozymes are effective modulators of gene expression due to their simple structure, site-specific cleavage activity and catalytic potential. The K-ras oncogene is thought to play an important role in the growth of pancreatic cancer, because an activated (mutated) ras gene is found in approximately 90% of human pancreatic cancers. In this study, we designed a hammerhead ribozyme directed against K-ras mRNA at codon 25 [K-ras Rz (25)], and investigated its efficacy in a cultured human pancreatic carcinoma cell line, MIA PaCa-2. K-ras Rz (25) significantly reduced the cellular K-ras mRNA level when introduced into the MIA PaCa-2 cells. The ribozyme suppressed cell growth. K-ras Rz (25) appears capable of reversing the malignant phenotype in human pancreatic carcinoma cells.     

The effect of taste masking agents on in situ gelling pectin formulations for oral sustained delivery of paracetamol and ambroxol

The aim of this study was to examine the influence of polyhydric alcohols (taste masking agents) on the rheological properties of in situ gelling pectin formulations and on the in vitro and in vivo release of paracetamol and ambroxol from these formulations. Gelation of orally administered pectin solutions containing calcium in complexed form occurred on release of calcium in the acidic environment of the stomach. Inclusion of 10% (w/v) sorbitol in 2% (w/v) pectin sols reduced the viscosity and ensured Newtonian flow properties. Xylitol and mannitol in similar concentrations were less effective in reducing viscosity; sucrose increased viscosity and caused non-Newtonian flow. The in vitro release of paracetamol from 2% (w/v) pectin gels formulated with 10% (w/v) of sorbitol, erythritol, xylitol or mannitol, and of ambroxol from 2% (w/v) pectin gels containing 10% (w/v) sorbitol, followed diffusion-controlled kinetics. Pectin gels (2%, w/v) containing sorbitol (10%, w/v) sustained the release of paracetamol in the rat stomach and bioavailabilities of approximately 90% of those from an orally administered paracetamol syrup were achieved. Sustained release of ambroxol from in situ gelling formulations was achieved with pectin concentrations of 1.5 and 1% (w/v) and a sorbitol concentration of 10% (w/v).     

Paeonianins A-E,new dimeric and monomeric ellagitannins from the fruits of Paeonia lactiflora

Four new dimeric ellagitannins, paeonianins A-D (2-5), were isolated from the fruits of Paeonia lactiflora, together with a new ellagitannin monomer, paeonianin E (1). Their structures were determined by spectroscopic methods. Paeonianins A-D (2-5) are positional isomers formed by condensation of pentagalloyl-beta-D-glucose (8) with 5-desgalloylstachyurin (6) or casuariin (7). Paeonianin E is a C-glycosidic ellagitannin having a gallic acid methyl ester moiety at the glucose C-1 position. This is the first report of the isolation of dimeric ellagitannins from a plant in the family Paeoniaceae.     

Sclerosing hemangioma of the lung. An epithelial tumor composed of immunohistochemically heterogenous cells

Lung tissues from 16 patients with pulmonary sclerosing hemangioma were studied with the use of serial sections and immunoperoxidase staining for surfactant apoprotein, secretory component (SC), and epithelial membrane antigen (EMA). The cells lining papillary projections or cystic spaces were stained with surfactant apoprotein, SC, and EMA. Characteristic round stromal cells, which were considered to be the main component of the sclerosing hemangioma, consisted of immunohistochemically heterogenous cells, that is, positive findings were attained with all three antigens, surfactant apoprotein- and EMA-positive ones, SC- and EMA-positive ones, only EMA-positive ones, and all three negative. When investigating the immunoreactivity of neoplastic type II pneumocytes in bronchioalveolar cell carcinoma and hyperplastic ones in nonneoplastic pulmonary disorders, the authors found that almost all the neoplastic type II pneumocytes had all three antigens. Many of the hyperplastic and normal type II pneumocytes, however, were stained with surfactant apoprotein and EMA but not with SC. The authors' findings add further support for the proposal that sclerosing hemangioma of the lung is epithelial in origin. In view of the various staining patterns found in the stromal cells, sclerosing hemangioma probably consists of immunohistochemically heterogenous epithelial cells. The staining pattern of the cells lining papillary projections or cystic spaces was similar to that of neoplastic type II pneumocytes rather than that of hyperplastic type II pneumocytes.     

High levels of intracellular ATP prevent nitric oxide-induced apoptosis in rat gastric mucosal cells

Nitric oxide (NO) plays an important role in gastric mucosal injury in the human stomach. Exposure to excessive NO leads to apoptosis; however, the mechanism remains largely unknown in gastric epithelial cells. The apoptotic process is modulated by energy states in cells. This study investigated molecular mechanisms of NO-induced apoptosis in gastric epithelial cells and influence of high glucose on those mechanisms. Normal rat gastric mucosal epithelial (RGM-1) cells were cultured in media containing either 1000 (low) or 4500 mg/l (high) of D-glucose. When the cells were incubated with a chemical NO donor NOC18, apoptosis was induced in a dose-dependent manner. Intracellular adenosine triphosphate (ATP) levels significantly increased in the cells cultured with high glucose in comparison with the low-glucose condition. The cells with high ATP levels were more resistant to NO-induced apoptosis than the cells with low ATP levels. NO-induced apoptosis was followed by mitochondrial depolarization, upregulation of Bax protein, cytochrome C release from mitochondria to the cytosol and subsequent caspases activation. These results suggest that NO inhibition of mitochondrial respiratory system and acute ATP depletion initiate apoptotic signalling in gastric epithelial cells. High glucose may prevent NO-induced apoptosis by leading to high levels of intracellular ATP or other metabolic changes in this cell line.     

Characterization of a trinucleotide repeat sequence (CGG)5 and potential use in restriction fragment length polymorphism typing of Mycobacterium tuberculosis

The genomes of 28 bacterial strains, including mycobacterial species Mycobacterium tuberculosis and Mycobacterium bovis, were analyzed for the presence of a special class of microsatellite, that of trinucleotide repeat sequences (TRS). Results of a search of all 10 possible TRS motifs (i.e., CCT, CGG, CTG, GAA, GAT, GTA, GTC, GTG, GTT, and TAT) with five or more repeating units showed that (CGG)(5) was highly represented within the genomic DNA of M. tuberculosis and M. bovis. Most of the (CGG)(5) repeats in the genome were within the open reading frames of two large gene families encoding PE_PGRS and PPE proteins that have the motifs Pro-Glu (PE) and Pro-Pro-Glu (PPE). (CGG)(5)-probed Southern hybridization showed that some mycobacterial species, such as Mycobacterium marinum, Mycobacterium kansasii, and Mycobacterium szulgai, possess many copies of (CGG)(5) in their genomes. Analysis of clinical isolates obtained from Tokyo and Warsaw with both IS6110 and (CGG)(5) probes showed that there is an association between the fingerprinting patterns and the geographic origin of the isolates and that (CGG)(5) fingerprinting patterns were relatively more stable than IS6110 patterns. The (CGG)(5) repeat is a unique sequence for some mycobacterial species, and (CGG)(5) fingerprinting can be used as an epidemiologic method for these species as well as IS6110 fingerprinting can. If these two fingerprinting methods are used together, the precise analysis of M. tuberculosis isolates will be accomplished. (CGG)(5)-based fingerprinting is particularly useful for M. tuberculosis isolates with few or no insertion elements and for the identification of other mycobacterial species when informative probes are lacking.     

Multiple atherosclerotic aneurysms of the bilateral subclavian artery, aortic arch and abdominal aorta.

Subclavian artery aneurysms are relatively rare in comparison with other peripheral aneurysms. We report a 65-year-old woman with multiple atherosclerotic aneurysms of the subclavian artery, aortic arch saccular aneurysm and abdominal aortic aneurysm. Two-staged operations by which the infrarenal abdominal aorta was replaced first and median sternotomy extending to the supraclavicular space for the concomitant resection of bilateral subclavian as well as aortic arch aneurysm resulted in good results.     

Preformed Angiotensin II is Present in Human Mast Cells

Summary Purpose The density of mast cells increases in the myocardium of patients suffering from heart failure. However, their function remains unclear. In this study, preformed angiotensin II (ANG II), a potent growth factor, was found to be contained in, and released by, human mast cells.Methods: The human mast cell line (HMC-1) was incubated with 0 to 10^–6 M calcitonin gene-related peptide (CGRP) or culture medium. The expression of renin-angiotensin system mRNA was examined using RT-PCR analysis. ELISA and immunohistochemistry with monoclonal antibody against human ANG II were performed to detect the presence of ANG II in HMC-1. The effect of CGRP on the expression of angiotensinogen mRNA was examined by quantitative RT-PCR analysis.Results: Preformed ANG II was detected in a human mast cell line (HMC-1) which is a neoplastic cell line of mast cells by ELISA and immunohistochemistry. Presence of mRNA of angiotensinogen and renin was confirmed by polymerase chain reaction in HMC-1, while mRNA of angiotensin converting enzyme (ACE) was undetectable. Since myocardial mast cells are interfaced with nerve fibers and functionally associated with CGRP, the effect of CGRP on ANG II release from HMC-1 was examined. CGRP induced the release of ANG II and increased angiotensinogen mRNA in HMC-1.Conclusions The presence of preformed ANG II and gene expression of the renin-angiotensin system were detected in human mast cells. The release and synthesis of ANG II in mast cells was regulated by CGRP.     

A clinical study of renal pelvic and ureteral cancer: prognosis and frequency of subsequent bladder cancer following surgical treatment

PURPOSE: A retrospective investigation of patients presenting with renal pelvic and ureteral cancer was performed. This study focused on the prognostic factors and frequency of subsequent bladder cancer following surgical treatment. MATERIALS AND METHODS: Forty-five patients presenting with transitional cell carcinoma, who had undergone nephroureterectomy at the Department of Urology, Okayama Central Hospital, from March 1990 to November 2000, were reviewed. Various factors were evaluated according to survival and non-bladder cancer occurrence rates. The Kaplan-Meier method was used in the analyses. RESULTS: Patients consisted of 33 males and 12 females (mean age was 71.7). Seventeen patients exhibited renal pelvic cancer, 25 cases displayed ureteral cancer and three subjects presented with multiple cancers. Eleven patients had received treatment for precedent or coexistent superficial bladder cancer by transurethral resection. The overall 5-year survival rate was 71.9%. Ten patients died as a result of the disease; in all cases, lymph node or distant metastasis had progressed. Pathological T factor, tumor grade and pN factor demonstrated a significant effect on survival; however, sex, age, tumor localization and incidence of subsequent bladder cancer had no influence on survival. The 5-year non-bladder cancer occurrence rate was 38.8%; additionally, all subsequent bladder cancer was disclosed within three years. Tumor multiplicity exclusively in the upper urinary tract significantly affected occurrence of bladder cancer. T factor and tumor grade revealed no correlation to occurrence. CONCLUSIONS: Adjuvant chemotherapy for prevention of clinical metastasis should be considered in cases involving pT3 or higher stage, grade 3, or in instances of pathologically confirmed lymph node metastasis. The significant occurrence of subsequent bladder cancer in the case of tumor multiplicity suggested that prophylactic therapy such as intravesical BCG instillation or chemotherapy might be beneficial.