New model for analysis of dynamic contrast-enhanced MRI data distinguishes metastatic from nonmetastatic transplanted rodent prostate tumors.

Dynamic contrast-enhanced MRI (DCEMRI) data were acquired from metastatic and nonmetastatic tumors in rodents to follow the uptake and washout of a low-molecular-weight contrast agent (Gd-DTPA) and a contrast agent with higher molecular weight (P792). The concentration vs. time curves calculated for the tumor rims and centers were analyzed using the two-compartment model (TCM) and a newly developed empirical mathematical model (EMM). The EMM provided improved fits to the experimental data compared to the TCM. Parameters derived from the empirical model showed that the contrast agent washout rate was significantly slower in metastatic tumors than in nonmetastatic tumors for both Gd-DTPA (P < 0.03) and P792 (P < 0.04). The effects of the tumor on blood flow in "normal" tissue immediately adjacent to the tumors were evident: Gd-DTPA uptake and washout rates were much lower in muscle near the tumor (P < 0.05) than normal muscle farther from the tumor. The results suggest that accurate fits of DCEMRI data provide kinetic parameters that distinguish between metastatic and relatively benign cancers. In addition, a comparison of the dynamics of Gd-DTPA and P792 provides information regarding the microenvironment of tumors.     

Inducible nitric oxide synthase inhibition by mycophenolic acid

The focus of this review is the influence of an immunosuppressive xenobiotic drug mycophenolic acid on the induction of nitric oxide production in various cell types. The potential therapeutic significance of the cell-specific fine-tuning of nitric oxide release by mycophenolic acid, as well as the mechanisms behind the drug action are discussed.     

N-methyl-3,4-methylenedioxyamphetamine-induced hepatotoxicity in rats: oxidative stress after acute and chronic administration

BACKGROUND: The underlying mechanisms of N-methyl-3,4-methylenedioxyamphetamine--MDMA--induced hepatotoxicity are still unknown. The aim of this study was to evaluate hepatic oxido-reductive status in the rats liver after the single and repeated administration of MDMA. METHODS: MDMA was dissolved in distilled water and administered in the doses of 5 mg, 10 mg, 20 mg, and 40 mg/kg. The animals from the acute experiment were treated per os with the single dose of the appropriate solution, through the orogastric tube. The animals from the chronic experiment were treated per os, with the doses of 5, 10, or 20 mg/kg of MDMA every day during 14 days. The control groups were treated with water only. Eight hours after the last dose, the animals were sacrificed, dissected, their livers were rapidly removed, frozen and stored at -70 degrees C until the moment of analysis. The parameters of oxidative stress in the crude mitochondrial fractions of the livers were analyzed. RESULTS: Superoxide dismutase (SOD) activity increased in the livers of the animals that were treated with single doses of MDMA. Chronically treated animals showed the increased SOD activity only after the highest dose (20 mg/kg). The content of reduced glutathione decreased in both groups, but the depletion was much more expressed after the single administration. Lipid peroxidation index increased in dose-dependent manner in both groups, being much higher after the single administration. CONCLUSION: The increased index of lipid peroxidation and the decreased reduced glutathione levels suggested that MDMA application induced the state of oxidative stress in the liver. These changes were much more expressed after the single administration of MDMA.     

NG-nitro-L-arginine methyl ester potentiates the effect of aminophylline on the isolated rat hemidiaphragm

The effects of different concentrations of N(G)-nitro-L-arginine methyl ester (L-NAME) (0.3, 1, 3, and 10 mM), a non-selective inhibitor of NOS, on the effect of aminophylline on the isometric contraction of the isolated rat hemidiaphragm were investigated. The muscle contractions were induced by direct subtetanic electrical stimulation. Aminophylline (0.36 - 3.60 mM) produced a typical concentration-dependent increase in both parameters of the isometric contraction: tension developed (Td) and the maximum rate of rise of tension (dT/dt max). The second series of additions of aminophylline produced a more pronounced effect. L-NAME (0.3, 1, 3, and 10 mM, 30 min of incubation without stimulation) itself did not change Td and dT/dt max. However, L-NAME (1, 3, and 10 mM) produced a statistically significant potentiation of the effect of aminophylline on Td and dT/dt max.     

Scorpinone: a new natural azaanthraquinone produced by a Bispora-like tropical fungus

Scorpinone (1), 3-methyl-6,8-methoxy-2-aza-9,10-anthraquinone, has been isolated from the mycelium of a cultured sterile fungus of Caribbean origin. The structure was elucidated by X-ray crystallography, and 2D NMR spectral data have been assigned. The compound is one of very few known fungal azaanthraquinones.     

Low-oxygen and high-carbon-dioxide atmosphere improves the conservation of hematopoietic progenitors in hypothermia

BACKGROUND: During short-term storage of hematopoietic cells (HCs) at 4°C a substantial decline in number and in functional capacity of progenitors occurs after 3 days. We hypothesized that physiologic O₂ and CO₂ concentrations of hematopoietic tissue microenvironment (approx. 3% O₂ and approx. 6% CO₂) could improve cell viability and functionality during storage at 4°C.
STUDY DESIGN AND METHODS: Mobilized peripheral blood (PB) CD34+ cells from multiple myeloma or non-Hodgkin's lymphoma patients were stored in flasks containing air (approx. 20% O₂ and approx. 0.05% CO₂) or 3% O₂/6% CO₂ atmosphere, for 3, 5, and 7 days at 4°C. The total number of cells, the number of cells in G0 or G1 phase of cell cycle, and the apoptosis rate were determined. The functional capacity of stored cells was assessed by the capacity of progenitors to form colonies in methylcellulose (colony-forming cells [CFCs]) and of stem cells to repopulate the bone marrow (BM) of immunodeficient mice (SCID-repopulating cell [SRC] assay).
RESULTS: The total number of viable cells and cells in G1 phase as well as the number of total CFCs were significantly higher at 3% O₂/6% CO₂ than in air at all time points. Cells in G0 phase and SRC were equally preserved in both conditions.
CONCLUSION: Atmosphere with low O₂ and high CO₂ concentration (3% O₂/6% CO₂) in hypothermia (+4°C) during 7 days of storage prevents cell damage and preserves a high number of functional HSCs and progenitors mobilized in PB by granulocyte–colony-stimulating factor.     

Hairy cell leukemia in first cousins and review of the literature

Familial hairy cell leukemia (HCL) occurs rarely. So far, 26 familial instances of HCL (in 12 families) have been reported in the literature. The consistent human leukocyte antigen (HLA) linkage could not be established in most cases of familial HCL. History of exposure to organic chemicals or employment in woodworking or farming was noted in only two out of 11 affected families. We present two familial cases of HCL as well as a thorough literature review. An influence of HLA or farming themselves on a predisposition to HCL remains unproven but does not rule out an HLA-linked and as yet unidentified gene responsible for increased disease susceptibility. HCL in families is unlikely to be due to random patterning, but there are insufficient data so far to decisively incriminate either HLA-related or environmental causative factors.     

Assessment of four biochemical markers of bone metabolism in postmenopausal osteoporosis

In order to sudy the specificity and sensitivity of markers of bone metabolism in postmenopausal osteoporosis we investigated bone alkaline phosphatase, osteocalcin and carboxyl-terminal propeptide of procollagen type I in sera as markers of bone formation, and deoxypyridinoline in urine as a marker of bone resorption. The investigated parameters were determined in 53 women with confirmed osteoporosis and in a control group consisting of 45 healthy postmenopausal women without bone changes who were 40 to 79 years old. All biochemical markers were determined by monoclonal competitive enzyme immunoassay tests obtained by Metra Biosystems. The activity of bone alkaline phosphatase and the concentration of osteocalcin, procollagen type IVC-terminal propeptide (PICP), and deoxypyridinoline were grouped according to age of postmenopausal healthy and osteoporotic women. The values of all bone markers gradually increased with age, but significantly higher values were obtained in groups of postmenopausal osteoporotic women. By using receiver operator characteristic curve analysis, a very high specificity and sensitivity of the investigated biochemical markers in the diagnosis of postmenopausal osteoporosis were proven. The areas under the PICP curve and the osteocalcin curve were significantly higher than the area under the deoxypyridinoline curve, demonstrating a higher discriminating power of PICP and osteocalcin than deoxypyridinoline (p < 0.05).