Comparison of action of the anti-neoplastic drug lonidamine on drug-sensitive and drug-resistant human breast cancer cells:31 P and 13C nuclear magnetic resonance studies

Lonidamine (LND) is a relatively new anti-cancer drug,and several clinical trials have indicated that it may be effectivein combinations with other therapeutic modalities. LND isclassified within the metabolic inhibitor agents. Multidrugresistance (MDR) phenomenon is often associated with increasedenergy requirements, and enhanced glycolysis rate. These studieswere performed to delineate the mechanism of action of LNDon MDR human breast cancer cells, and to investigate whetherLND as a single agent, or in combination with anotheranti-metabolism drug, 2-deoxyglucose (2-DG), may be usefulagainst MDR tumors. The effects of LND on intact perfuseddrug-sensitive (WT) and 33-fold resistant to Adriamycin(Adr) MCF-7 cells, embedded in alginate micro capsules, were continuouslymonitored by ³¹P and ¹³C nuclearmagnetic resonance (NMR) spectroscopy. ³¹PNMR studies showed that LND induced intracellular acidificationand depletion of NTP in both WT and Adr cells. However, pH and NTPlevels decreased less in the Adr cells than in the WT cells(p < 0.05 for both parameters). ¹³CNMR demonstrated that LND inhibited lactate transport,and lactate signals were elevated in both cell lines. However, theintracellular lactate levels increased to a greater extentin the WT than in the Adr cells (p < 0.05).There were major differences in the effects of LND onmetabolism between sensitive and resistant cells.While LND enhanced glucose uptake in the WT cells, and itsadministration was followed by continuous increase oflactate signal, both processes were not affected by LNDin the Adr cells. 2-DG is a glucose analogue that inhibitsboth cellular uptake and utilization of glucose, leading to cell starvation. Combined treatment with LND and2-DG yielded at best additive, but not synergistic,cellular toxicity, and the metabolic effects of LNDwere attenuated by 2-DG. These results showed that the principalmechanism of action of LND is inhibition of lactate transportleading to intracellular lactate accumulation and acidificationin both WT and Adr cells. The Adr cells were only 2-fold resistantto LND (compared to the WT cells), and since cellular uptakeof alkaloid chemotherapy is improved in acidic environment,LND may have a role in the treatment protocols of MDR tumors,especially when given as the initial means for inductionof intracellular acidification.     

Expression of activated extracellular signal-regulated kinases 1/2 in malignant melanomas: relationship with clinical outcome.

PURPOSE: The purpose of the present work was to analyze the protein expression of activated extracellular signal-regulated kinases 1 and 2 (ERK1/2) in a panel of superficial spreading (SSM) and nodular (NM) primary and metastatic melanomas, and to correlate the expression level with clinicopathological parameters. EXPERIMENTAL DESIGN: Expression of activated ERK1/2 was examined by immunohistochemistry in 172 primary melanomas (108 SSM and 64 NMs), 67 metastatic lesions, and in 41 benign nevi. RESULTS: Fifty four percent of primary and 33% of metastatic melanomas expressed variable levels of activated ERK1/2. No immunoreactivity was detected in benign nevi. In 21% of the primaries only cytoplasmic expression was detected, whereas 3% and 30% showed positive immunoreactivity in either nucleus or cytoplasm and nucleus, respectively. Activated ERK1/2 expression varied significantly with the thickness of superficial spreading melanomas, with lower expression in thinner lesions (P = 0.016). A significant correlation between activated ERK1/2 and cyclin D1 (P = 0.031) in nodular, as well as between activated ERK1/2 and cyclin D3 (P = 0.030) in SSMs were observed. The protein level of p27(Kip1) correlated with activated ERK1/2 (P = 0.048) in the nucleus. Furthermore, a strong inverse correlation between activated ERK1/2 and membrane-bound beta-catenin (P = 0.004) in nodular melanomas was revealed. Activation of ERK1/2 did not have any impact on relapse-free or overall survival. CONCLUSION: Our results suggest that activation of ERK1/2 may be involved in cell cycle regulation in SSMs. Moreover, the inverse association between membrane-bound beta-catenin and ERK1/2 in NMs suggest that ERK1/2 activation may play a role in decreasing homotypic interactions through destabilization of beta-catenin.     

The Effects of Chitosan-PEG Nanoparticles Based on Channa striata Protein Hydrolyzate on Decreasing Diabetes Mellitus in Diabetic Rats

BackgroundChanna striata has several good nutrients, including 70% protein, 20% albumin, complete amino acids, zinc, selenium, and iron. However, no study has investigated the chitosan-PEG nanoparticles based on Channa striata protein hydrolyzate. This study''s purpose was to determine the role of 10% Channa striata protein hydrolyzate, chitosan-PEG 4000 nanoparticles, and chitosan-PEG 6000 nanoparticles in reducing diabetes mellitus in diabetic rats.MethodA randomized pretest-posttest control group design was used, with male Sprague-Dawley rats being divided into five groups: STZ, acarbose, hydrolyzate, chitosan-PEG 4000 nanoparticles, and chitosan-PEG 6000 nanoparticles. Diabetes was induced by a single injection of streptozotocin at 1 ml in each formulation. Blood glucose levels were analyzed using a glucometer 7, 14, and 21 days after treatment. The CHOD-PAP method was used to analyze the lipid profile. Pancreas and liver histology analyses were carried out using a microscope.ResultsThe formulation of 10% Channa striata protein hydrolyzate and PEG 6000 was the most effective in lowering blood glucose concentrations, and the response was close to the acarbose result. The glucose concentration decreased after daily oral administration of chitosan-PEG nanoparticles for 21 days. The plasma cholesterol, triglycerides, LDL, and HDL concentrations were lower in treated than in untreated diabetic rats.ConclusionThis study concluded that the formulation of 10% Channa striata protein hydrolyzate and chitosan-PEG 6000 nanoparticles was more effective than acarbose.     

Measuring the Year Consumption of Alcohol: The Development of a Questionnaire

Most general alcohol consumption population surveys are meant to represent the year consumption, although they actually ask only for habitual drinking and/or frequencies and quantities of binge drinking in the past months. These surveys typically cover about half of the alcohol sales figures. In order to enhance sales coverage and to reduce seasonal bias, we developed a year consumption questionnaire on the basis of daily and weekly drinking adding 13 categories of less-than-weekly drinking occasions over the year. As a first test we offered the new questionnaire together with a traditional typical week questionnaire, in different modes to various groups adding up to a purposive high diversity sample of 101 drinking persons (56 women, 44 men, 16–69 years old, mean age 34 years). After correction for overlaps between weekly habits and less-than-weekly occasions, the new questionnaire produces considerably higher reports of annual consumption, compared with the typical-week-based estimates of year consumption. Limitations of the study are discussed.     

NMR spectroscopic characterization of sarcolemmal permeability during myocardial ischemia and reperfusion.

This study aims to characterize the pattern of membrane disintegration during myocardial ischemia and reperfusion. Intracellular volumes were measured by 1H and 59Co NMR in isolated rat hearts during 10, 30 and 60 min of total ischemia and 30 min of reperfusion at normothermia. Perfusion with hypo-osmotic medium (210 mosm/l) increased intracellular water from 2.50+/-0.06 to 3.07+/-0.07 ml/g dry weight (P<0.001) during pre-ischemia. Hypo-osmotic swelling decreased by 16+/-3, 32+/-6 and 44+/-11% of the pre-ischemic value after 10, 30 and 60 min of ischemia (n.s., P<0.005, P<0.001) respectively, indicating that membrane permeabilization facilitated efflux of osmolytes and counterbalanced the osmotic driving force for water influx. Hypo-osmotic swelling decreased during 30 min of reperfusion by 18+/-5% in all groups (P<0.0.005 v post-ischemia). The volume of distribution of the extracellular marker cobalticyanide increased by more than 3.2+/-0.4 and 5.8+/-0.5% of the intracellular space after 30 and 60 min of ischemia respectively (P<0.001), and by an additional 2% after reperfusion. During 30 min of reperfusion, hearts released 1.6+/-0.2 and 3.2+/-0.4% of the intracellular creatine kinase contents after 30 and 60 min of ischemia, respectively (P<0.001). In addition to the correlation between ischemia duration and membrane permeability, evident from the analysis of each probe, the data showed a progressive increase in severity of membrane injury over time and permeabilization to larger molecules. 23Na NMR spectroscopy in conjunction with an extracellular shift reagent (SR) showed formation of a resonance at an intermediate chemical shift in between the intra and extracellular Na+ peaks, suggesting penetration of SR into cells with disrupted membranes. The constant chemical shift and narrow line shape of this resonance, characteristic of a homogeneous chemical environment, suggested that the distribution of SR was contained within the cytosol of cardiomyocytes. We propose that sarcolemmal membranes are gradually permeabilized to larger molecules by ischemia, and the evolving chemical instability is spatially contained within the myocyte.     

Triassic–Jurassic climate in continental high-latitude Asia was dominated by obliquity-paced variations (Junggar Basin, ürümqi,China)

Empirical constraints on orbital gravitational solutions for the Solar System can be derived from the Earth’s geological record of past climates. Lithologically based paleoclimate data from the thick, coal-bearing, fluvial-lacustrine sequences of the Junggar Basin of Northwestern China (paleolatitude ∼60°) show that climate variability of the warm and glacier-free high latitudes of the latest Triassic–Early Jurassic (∼198–202 Ma) Pangea was strongly paced by obliquity-dominated (∼40 ky) orbital cyclicity, based on an age model using the 405-ky cycle of eccentricity. In contrast, coeval low-latitude continental climate was much more strongly paced by climatic precession, with virtually no hint of obliquity. Although this previously unknown obliquity dominance at high latitude is not necessarily unexpected in a high CO₂ world, these data deviate substantially from published orbital solutions in period and amplitude for eccentricity cycles greater than 405 ky, consistent with chaotic diffusion of the Solar System. In contrast, there are indications that the Earth–Mars orbital resonance was in today’s 2-to-1 ratio of eccentricity to inclination. These empirical data underscore the need for temporally comprehensive, highly reliable data, as well as new gravitational solutions fitting those data.Our understanding of Triassic and Early Jurassic high-latitude climate, biotic evolution, mass extinction, and geochronology is very poor in contrast to that of the contemporaneous tropics (1, 2). This poor resolution impairs an elucidation of the basic patterns of Earth system function during the early Mesozoic, notably the high-latitude climatic response to orbital forcing, as well as the effects of the eruption of the Triassic–Jurassic Central Atlantic Igneous Province (CAMP) (3). The former issue bears on the stability of the Solar System, in which determining variations in orbital eccentricity (via climatic precession) and inclination (via obliquity) figure as crucial (4–6), and the latter bears on the causes, effects, and recovery from the end-Triassic mass extinction (ETE) (e.g., ref. 2). Here, we describe results of a cyclostratigraphic investigation of lithologic variations in the paleo-high latitude, lacustrine, Late Triassic–Early Jurassic Haojiagou and Badaowan formations of the Junggar Basin, China representing, to our knowledge, the first analysis of orbital cyclicity from a high-latitude, early Mesozoic continental sequence, and a step toward development of an empirical basis for evaluating numerical solutions of Solar System chaotic behavior.     

Metallo-beta-lactamases as emerging resistance determinants in Gram-negative pathogens: open issues

The rapid spread of acquired metallo-beta-lactamases (MBLs) among major Gram-negative pathogens is a matter of particular concern worldwide and primarily in Europe, one of first continents where the emergence of acquired MBLs has been reported and possibly the geographical area where the increasing diversity of these enzymes and the number of bacterial species affected are most impressive. This spread has not been paralleled by accuracy/standardisation of detection methods, completeness of epidemiological knowledge or a clear understanding of what MBL production entails in terms of clinical impact, hospital infection control and antimicrobial chemotherapy. A number of European experts in the field met to review the current knowledge on this phenomenon, to point out open issues and to reinforce and relate to one another the existing activities set forth by research institutes, scientific societies and European Union-driven networks.