Kinase-addiction and bi-phasic sensitivity-resistance of Bcr-Abl- and Raf-1-expressing cells to imatinib and geldanamycin

By activating anti-apoptotic factors (e.g., Hsp70, Raf-1, Bcl-xL), Bcr-Abl blocks apoptotic pathways at multiple levels, thus rendering leukemia cells resistant to chemotherapeutic agents such as doxorubicin (DOX). In Bcr-Abl-transfected HL60 (HL/Bcr-Abl) cells, procaspase-9 was increased and partially processed. The Bcr-Abl inhibitor imatinib (Gleevec, STI-571) released the apoptotic stream. Also, HL/Bcr-Abl cells were hyper-sensitive to geldanamycin (GA), which depletes Bcr-Abl and Raf-1. Raf-1 and Bcr-Abl-transfected FDC-P1 hematopoietic cells were selectively sensitive to GA and imatinib, respectively. Remarkably, cell clones with high levels of Bcr-Abl that could not be depleted by GA were relatively resistant to both GA and imatinib. GA and flavopiridol sensitized such resistant cells to imatinib. These data suggest bi-phasic sensitivity to mechanism-based therapeutic agents. Although Bcr-Abl renders cells hyper-sensitive, an excess of Bcr-Abl results in resistance (due to the remaining activity). We discuss therapeutic approaches to overcome bi-phasic resistance to mechanisms-based agents.     

Ile118Val genetic polymorphism of CYP3A4 and its effects on lipid-lowering efficacy of simvastatin in Chinese hyperlipidemic patients

Objectives To determine the frequencies of CYP3A4 alleles (CYP3A4*4,*5 and *6) in Chinese hyperlipidemic patients and to observe the impact of CYP3A4*4 (Ile118Val) genetic polymorphism on the lipid-lowering effects of simvastatin and on the activity of CYP3A4.Methods From hospitalized and non-hospitalized patients, 211 unrelated hyperlipidemic patients were recruited for genotyping. CYP3A4 genotypes were determined by means of polymerase chain reaction and restriction fragment length polymorphism analysis. Of the non-hospitalized hyperlipidemic patients, 8 with CYP3A4*1/*1 and 8 with CYP3A4*1/*4 genotypes were selected to be treated with 20 mg simvastatin daily for 4 weeks. Serum triglycerides (TG), cholesterol (CHO) and low-density lipoprotein (LDL) levels were determined using an automated analyzer (Hitachi 747, Boehringer Mannheim, Mannheim, Germany). CYP3A4 activity was determined by the ratio of 6-hydroxycortisol to free cortisol (6-OHC/FC) in the morning spot urine with a high-throughput liquid chromatography–tandem mass spectrometry method.Results Of 211 subjects, 14 (allele frequency 3.32%) were heterozygous for CYP3A4*4 (Ile118Val). Nevertheless, no subjects with a CYP3A4*5 or CYP3A4*6 allele or homozygous for CYP3A4*4 were identified. The ratio of 6-OHC/FC was 9.9±13.7 and 56.6±35.7 in subjects with the Ile118Val variant (n=8) and in CYP3A4 wild-type subjects (n=8), respectively (P=0.0039). After oral intake of simvastatin 20 mg daily for 4 weeks, the change of serum lipids in CYP3A4*1/*1 and CYP3A4*1/*4 groups showed a significant difference, with a mean decrease in triglycerides and total cholesterol of 38.1±7.6% versus 25.1±8.3% (P=0.034) and of 35.8±9.6% versus 22.0±20.4% (P=0.0015) (means ± SD), respectively. We found no statistically significant difference in the reductions of LDL between subjects carrying the *1 and *4 genotypes (29.0±7.4% versus 36.8±8.8%, P=0.0721).Conclusions The allele frequency of CYP3A4*4 was 3.32% among the hyperlipidemic patients from the Chinese mainland. CYP3A4*4 was an allelic variant related to a functional decrease of CYP3A4 activity, and *4 expression seemed to increase the lipid-lowering effects of simvastatin.     

Evaluation of interaction between intrathecal adenosine and MK801 or NBQX in a rat formalin pain model

Adenosine and excitatory amino acids have been known to be involved in modulating nociceptive transmission at the spinal level. The authors assessed the characteristics of the interaction of the adenosine-excitatory amino acid antagonist combinations in the spinal cord of rats on the formalin-induced nociception. Intrathecal NMDA antagonist ((5R, 10S)-(+)-5-methyl-10,11-dihydro-(5)H-dibenzo[a[,]d]cyclohepten-5,10-imine hydrogen maleate, MK801, 30 microg) and AMPA antagonist (2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[F]quinoxaline-7-sulfonamide, NBQX, 3 microg) decreased the total number of flinches during both phases in the formalin test. Intrathecal adenosine (300 microg) had little effect on the phase 1 flinching response, but decreased the phase 2 response. The fixed dose analysis and the isobolographic analysis revealed that adenosine interacts additively with MK801 and NBQX in the spinal cord.     

Improved mitochondrial bioenergetics by anesthetic preconditioning during and after 2 hours of 27 degrees C ischemia in isolated hearts

We examined if sevoflurane given before cold ischemia of intact hearts (anesthetic preconditioning, APC) affords additional protection by further improving mitochondrial energy balance and if this is abolished by a mitochondrial KATP blocker. NADH and FAD fluorescence was measured within the left ventricular wall of 5 groups of isolated guinea pig hearts: (1) hypothermia alone; (2) hypothermia+ischemia; (3) APC (4.1% sevoflurane)+cold ischemia; (4) 5-HD+cold ischemia, and (5) APC+5-HD+cold ischemia. Hearts were exposed to sevoflurane for 15 minutes followed by 15 minutes of washout at 37 degrees C before cooling, 2 hours of 27 degrees C ischemia, and 2 hours of 37 degrees C reperfusion. The KATP channel inhibitor 5-HD was perfused before and after sevoflurane. Ischemia caused a rapid increase in NADH and a decrease in FAD that waned over 2 hours. Warm reperfusion led to a decrease in NADH and an increase in FAD. APC attenuated the changes in NADH and FAD and further improved postischemic function and reduced infarct size. 5-HD blocked the cardioprotective effects of APC but not APC-induced alterations of NADH and FAD. Thus, APC improves redox balance and has additive cardioprotective effects with mild hypothermic ischemia. 5-HD blocks APC-induced cardioprotective effects but not improvements in mitochondrial bioenergetics. This suggests that mediation of protection by KATP channel opening during cold ischemia and reperfusion is downstream from the APC-induced improvement in redox state or that these changes in redox state are not attenuated by KATP channel antagonism.     

The services for women victims of sexual violence: a qualitative study

OBJECTIVE: To assess public services attending female victims of sexual violence in the city of Sao Paulo. METHODS: This is a qualitative study conducted in two public services attending female victims of sexual violence. Interviews with 42 women were conducted, 13 of whom had sought these services for assistance and 29 were professionals working in these services. Evaluation of the services was based on the categories: reception, access, resolvability and sanitary responsibility. RESULTS: The analysis of the interviews per category has shown that there was reception in both services, problems with respect to access due to the lack of information concerning these services, and quality resolvability with a multi-professional team. As to the sanitary responsibility, it is present in these specialized services but is deficient in the emergency services and basic health care units. Many women are unaware of the rights they are entitled to with respect to specialized services. Frequently their late arrival compromises the efficacy of care. There are deficiencies both in terms of reference and counter reference. CONCLUSIONS: The results ratify the importance of these services and the need for their decentralized expansion. Health courses should introduce the theme of sexual violence at the undergraduate level.     

Nonylphenol and Nonylphenol Ethoxylates in River Water, Drinking Water,and Fish Tissues in the Area of Chongqing, China

Little attention has been paid to the estrogenic-like compounds, such as 4-nonylphenol (4-NP) and its potential precursor nonylphenol ethoxylates (NPEOs), in China although its usage is huge. Water samples and corresponding drinking water samples were seasonally collected at five sites of each of the two main rivers in Chongqing Area. Individual nonylphenol ethoxylates (NPEOs) and 4-NP in the Changjiang River and Jialingjiang River were detected by normal-phase liquid chromatography electrospray ionization mass spectrometry and gas chromatography-mass spectrometry. The results indicated that of the five sampling points in the two rivers, NPEOs were the dominant pollutant in April and December with the similar distribution profile, and total NPEOs with different ethylene oxide lengths were 6.9–97.6 g/L in April and 2.5–52.7 g/L in December. However, NP was the dominant pollutant in July with a concentration of 1.7–7.3 g/L. Corresponding drinking water samples derived from river water as source suggested that the conventional water treatment process used in the five waterworks could remove NPEOs from the source water with high removal efficiency (>99%). The 4-NP removal efficiency, however, varied in a range of 62% to 95%, leaving a significantly high concentration of NP (0.1 to 2.7 g/L) in drinking water in July. Fish samples taken in December 2000 contained 4-NP of 1.9g/g and NPEOs of 0.4–48.3g/g, with the highest concentration level found in liver.     

Canine carpal joint fusion: a model for four-corner arthrodesis using a porous tantalum implant

PURPOSE: Interest has focused on porous materials that promote bony ingrowth. In this study a porous tantalum implant was used as an adjunct to intercarpal stabilization in a canine model of wrist arthrodesis. METHODS: A defect was created at the junction of the radiocarpal, ulnocarpal, and fourth carpal bones, analogous to a four-corner fusion site in humans. A tantalum cylinder was press-fit and stabilized with K-wires. Controls were represented by creating the defect without implant placement. Animals were killed at 4, 8, and 12 weeks. RESULTS: Histology showed bony ingrowth as early as 4 weeks and mechanical testing showed a statistically significant increase in strength of the construct over time. Controls failed to achieve union at any time point. CONCLUSIONS: The implant served as an adjunct to stabilization of the carpus in this model of four-corner fusion, suggesting a novel application of this material in conditions in which bone graft has been required previously. This study represents a preliminary investigation of the use of a tantalum device for intercarpal stabilization; it does not compare this technique with conventional methods.