Impact of Smoking Cessation in Donor Candidates for Living Donor Liver Transplantation.

BACKGROUND: The relationship between smoking cessation and weight gain is well recognized. Examining the link between smoking cessation and weight gain in donor candidates for living donor liver transplantation (LDLT) is an important topic because of the influence of weight gain on the liver. This study assessed body weight (BW) changes after smoking cessation in donor candidates for LDLT. METHODS: The 27 donor candidates were retrospectively analyzed. The smoking status was determined based on questionnaires administered at the initial presentation, and the candidates were divided into 2 groups: recent quitters and nonsmokers. The changes in BW were compared between the groups. RESULTS: The recent quitters group included 10 (37.0%) candidates, and the nonsmokers group included 17 (63.0%). In the nonsmokers group, 1 candidate had gained weight since the initial presentation. In contrast, in the recent quitters group, 70.0% of candidates had gained weight since the initial presentation (P < .01). The change in BW from the initial presentation was greater in recent quitters than in nonsmokers (+1.6 kg [+2.4%] vs -0.5 kg [-0.9%]; P < .01). Two candidates in the recent quitters group gained ≥ 5 kg [8%] of weight. One of these 2 candidates was judged to be in a donor-inadequate status because of the appearance of fatty liver. CONCLUSIONS: Weight gain due to smoking cessation was observed in donor candidates for LDLT. The amount of weight gain after smoking cessation is highly individualized, so everyone concerned with LDLT must be alert to its potential development.

Expression profiling of microRNAs in RAW264.7 cells treated with a combination of tumor necrosis factor alpha and RANKL during osteoclast differentiation.

BACKGROUND AND OBJECTIVE: Tumor necrosis factor alpha (TNF-α), a cytokine involved in the pathogenesis of periodontal disease, induces osteoclast differentiation and indirectly promotes alveolar bone resorption. We investigated TNF-α-regulated osteoclast differentiation, focusing on microRNAs. MicroRNAs are small, noncoding RNAs that are involved in various biological processes, including cellular differentiation, proliferation and apoptosis. Aside from miR-21, miR-155 and miR-223, the identities of the microRNAs that play roles in osteoclast differentiation are unknown. Notably, no previous studies have reported the expression profiling of microRNAs during TNF-α-regulated osteoclast differentiation. MATERIAL AND METHODS: We used microarrays to screen the levels of expression of mature microRNAs in RAW264.7 cells treated with a combination of TNF-α and RANKL, or RANKL alone for 0, 24 or 82 h during osteoclast formation. We validated the results of the microarray analyses through quantitative RT-PCR analyses of representative microRNAs in RAW264.7 cells and murine bone marrow macrophages. RESULTS: During osteoclast formation, the expression of 44 mature microRNAs differed by more than twofold between untreated cells and cells treated with a combination of TNF-α and RANKL, and the expression of 52 mature microRNAs differed upon RANKL treatment. According to quantitative RT-PCR analyses, miR-378 was upregulated and miR-223 was downregulated during osteoclast formation. Furthermore, miR-21, miR-29b, miR-146a, miR-155 and miR-210 were highly expressed during osteoclast differentiation in TNF-α/RANKL-treated cells compared with RANKL-treated cells. CONCLUSIONS: These results suggest that miR-223 and miR-378 may play important roles in osteoclastogenesis, and that miR-21, miR-29b, miR-146a, miR-155 and miR-210 are involved in TNF-α-regulated osteoclast differentiation.

Study of antioxidant properties of a water-soluble Vitamin E derivative-tocopherol monoglucoside (TMG) by differential pulse voltammetry.

Study of antioxidant properties of tocopherol monoglucoside (TMG), a water-soluble Vitamin E derivative, by differential pulse voltammetry has been carried out in this work. The pH influence on the antioxidant properties of TMG has been also investigated. It was observed that the antioxidant activity of TMG is greater at 6.90

Effects of phenolic compounds on reactions involving various organic radicals.

Investigation of effects produced by 26 various phenol and diphenol derivatives, including industrial and natural antioxidants (ionol, bis-phenol 2246, alpha-tocopherol), on final product yields of radiation-induced free-radical processes involving peroxyl, alkyl, alpha-hydroxyalkyl and alpha,beta-dihydroxyalkyl radicals has been performed. Ionol and bis-phenol 2246 have been shown to be more effective than alpha-tocopherol or diphenol derivatives in suppressing hydrocarbon oxidation processes. At the same time, alpha-tocopherol and its water-soluble analogues, as well as diphenol-based substances, are more effective than phenol derivatives in regulating various homolytic processes involving carbon-centered radicals. This fact can be accounted for by taking into consideration the contribution to formation of the final product set and the respective yields made by semiquinone radicals and compounds with quinoid structure arising in the course of homolytic transformations in systems containing diphenol derivatives.

Effect of a hypoxic radiosensitizer, AK 2123 (Sanazole), on yeast Saccharomyces cerevisiae.

Sanazole/DNA repair/Hypoxic radiosensitization/DNA polymerases/Saccharomyces cerevisiae Yeast Saccharomyces cerevisiae can exist in two physiological states, namely anaerobic and aerobic. They differ in their response to gamma- radiation and radiomodification. We report hereon our results concerning radiosensitization by Sanazole (AK-2123), a well-known hypoxic radio sensitizer, whose mechanism of action has been studied extensively. The results have revealed that Sanazole (1 mM) when present during irradiation could specifically sensitize wild-type anaerobic yeast cells with a DMF of 2.4. In a radiation-sensitive mutant which lacks a DNA repair pathway specific for the recovery from gamma-radiation induced DNA damage, the extent of sensitization was considerably lower and the DMF was only 1.3. Studies on the liquid holding recovery of cells of both wild- type and rad52 yeast cells exposed to radiation in presence of Sanazole revealed that sensitization by Sanazole is due to a preferential increase in the DNA damage, and not by impairing DNA repair. This system thus holds promise for screening potential hypoxic chemical radiosensitizers.

Nitrotriazole AK-2123 enhances mitomycin C activity in mice bearing multidrug-resistant tumors.

The often observed cross resistance of multidrug-resistant (MDR) tumors to mitomycin C (MMC) is surprising, as these tumors are, as a rule, sensitive to alkylating drugs, and the mechanism of MMC activity is connected to alkylation of DNA. This study shows that nitrotriazole AK-2123 significantly enhances the sensitivity of MDR-strains of P388 mouse leukemia (developed and characterized by authors previously) to mitomycin C. The modulating effect is dependent on the initial sensitivity of resistant tumors to MMC which is correlated with the existence or absence of sorcin (cytosole Ca2+-binding protein) gene coamplification in MDR-amplicon. In agreement with authors' previous data about AK-2123 influence on active Ca2+-transport, it is supposed that the modulatory effect of radiosensitizer is at least partially dependent on this capacity. AK-2123 has no own antitumor effect on investigated tumors and cannot modify the sensitivity of the parent tumor P388 to MMC.

Redox reactions of sanazole (AK-2123) in aqueous solutions: a pulse radiolysis study.

The redox chemistry of sanazole, an efficient hypoxic cell radiosensitizer, generally referred to as AK-2123, was studied by pulse radiolysis with eaq-, CO2-., 2-propanol radicals and CH2OH radicals. AK-2123 reacts with eaq-, CO2-. and 2-propanol radicals at almost diffusion-controlled rates, producing a nitro radical anion (lambda max = 290 nm) within a few microseconds. The decay kinetics of the radical anion was independent of the pH. The radical anion reacts with oxygen with a rate constant of 3.4 x 10(6) dm3 mol-1 s-1. An electron-transfer reaction was observed from the thymine radical anion to AK-2123. From redox equilibria with methyl viologen, the one-electron reduction potential of AK-2123 in aqueous solution, determined by pulse radiolysis, was estimated to be -0.33 +/- 0.02 V vs. NHE. Depletion of intracellular nonprotein thiols did not mitigate the radiosensitizing affect of the hypoxic radiosensitizer, AK-2123.

Inhibitory effect of radiosensitizer AK-2123 on experimental hepatic metastases and Ca2+ active transport.

A triazole group radiosensitizer AK-2123 is shown to inhibit considerably the growth of hepatic metastases induced by the intrasplenic injection of colon adenocarcinoma cells in syngenic mice. Even an extremely low dose of the drug exhibits the antimetastatic effect. It is shown that AK-2123 injected at therapeutic dose inhibits active transport of calcium ions by the (Ca2+-Mg2+)-dependent ATP-ase. The antimetastatic effect of AK-2123 is suggested to be related, at least partially, to the inhibition of the active calcium transport.

Modification of radio-thermo-chemotherapy by AK-2123 and hydralazine in tumor bearing mice.

The effects of chemical modifiers of hypoxic radiosensitizer, a 3-nitrotriazole derivative AK-2123 (200 mg/kg) before treatment, and vasodilator of hydralazine (HDZ; 5.0 mg/kg) after treatment on tumor growth of SCCVII of mice were investigated in the radio-thermotherapy combined with mitomycin C (MMC; 2.0 mg/kg) or adriamycin (ADM; 3 mg/kg). The tumor treated by 10 Gy alone (tumor doubling time = 7.5 days), MMC alone (6.9 days), and hyperthermia (43 degrees C, 30 min; HT) alone (8.0 days) showed a slight growth delay (control: 5.6 days). Prolonged growth delay (23.2 days) was observed by MMC-radio-thermotherapy (MMC-10Gy/HT) than that (12.4 days) by 10 Gy/HT. The modification of MMC-radio-thermotherapy by HDZ administered between 10 Gy and HT (MMC-10 Gy/HDZ/HT) resulted in the significant prolongation of tumor growth delay (31.7 days). AK-2123 administration before this treatment, (MMC-AK-2123)-10 Gy/HDZ/HT), enhanced a further tumor growth delay (37.6 days) which is equal to that by 50 Gy alone and resulted in the highest dose modifying factor (DMF) of 5.2. While modification of ADM-radio-thermotherapy by AK-2123 and HDZ, (ADM-AK-2123)-10 Gy/HDZ/HT, gave the equal tumor growth delay to that by 30 Gy alone (DMF = 3.1). These high efficacies of radio-thermo-chemotherapy modified by AK-2123 and HDZ may be caused by tumor blood flow reduction.

Radiosensitizer AK-2123 as modulating agent in the chemotherapy of experimental metastases.

Therapeutic effect of Cyclophosphamide (CPA) and radiosensitizer AK-2123 (AK) combination versus CPA alone in the same doses was investigated on transplanted LL carcinoma and B 16 melanoma. Antimetastatic efficacy of different doses of CPA and combined therapy was evaluated. Our data demonstrate that the effect of combined treatment by CPA at low uneffective doses (60 mg/kg, 40 mg/kg, 20 mg/kg at the 3rd and the 7th day after transplantation) and AK at low daily doses (1 mg/kg and 0.1 mg/kg for 3-9 days after transplantation) is equal or superior to the effect of CPA alone at the therapeutic dose (120 mg/kg).

Nitrotriazoles bearing sulfur-substituted side chains: preparation and characterization as hypoxic cell radiosensitizers.

A series of 3-nitro-1,2,4-triazole (NTA) derivatives with -(CH2)mC(= Y)NH(CH2)nZCH3(Y, Z = O or S; m = 1 or 2; n = 2 or 3) group in the side chain at the N-1 position of NTA and their fluorinated analogs were synthesized. Their physicochemical properties and radiosensitizing activities in vitro and in vivo were investigated with respect, particularly, to the effects of sulfur substitution on the side chain of triazoles. The sulfur substitution of the oxygen atom in the side chain of NTA derivatives increased the partition coefficient (P value), but had little effect on the one-electron reduction potential. The derivatives bearing a thioether group in the side chain were more effective in vitro on hypoxic EMT6/KU cells, but were less effective in vivo on SCCVII tumor than their oxygen analogs. The thioamide compounds showed almost the same or slightly higher sensitizing activities in vitro compared with their oxygen analogs.

Alpha 1 adrenoceptor mediated signal transduction in neonatal rat ventricular myocytes: effects of prolonged hypoxia and reoxygenation.

STUDY OBJECTIVE: The aim was to study the effects of prolonged hypoxia and reoxygenation on alpha 1 adrenoceptors and inositol phosphate accumulation in neonatal rat ventricular myocytes maintained in culture for 6-8 d. DESIGN: Neonatal rat ventricular myocytes were subjected to 2 h hypoxia followed by 2 h reoxygenation. Cells were harvested at various times during hypoxia and after reoxygenation and measurements of alpha 1 adrenoceptor density and affinity and determinations of basal and (-)-noradrenaline stimulated inositol phosphate accumulation were carried out. EXPERIMENTAL MATERIAL: A neonatal rat ventricular myocyte preparation almost completely free of contaminating non-myocytes was used. Cells were grown in serum containing medium for 5 d before experiments were performed. alpha 1 Adrenoceptors were measured using the radioligand 125I-HEAT and inositol phosphates were measured by anion exchange chromatography after incubation with 1 microM (-)-noradrenaline for 5 min. MEASUREMENTS AND MAIN RESULTS: Hypoxia resulted in an increase in alpha 1 adrenoceptor density which was reversed by reoxygenation. There were no changes in antagonist affinity. (-)-Noradrenaline stimulated inositol phosphate production was increased at 1 h hypoxia but declined to control levels after 2 h hypoxia, while basal levels increased significantly at this time. This pattern was similar for all inositol phosphates measured: inositol-1-phosphate, inositol bisphosphate, and the putative second messenger, inositol trisphosphate. Displacement by (-)-noradrenaline of 125I-HEAT binding was significantly shifted to the right after 2 h hypoxia. CONCLUSIONS: Prolonged hypoxia in neonatal rat ventricular myocytes increases alpha 1 adrenoceptor density without change in antagonist affinity. Inositol phosphates follow a biphasic response, increasing after 1 h and decreasing after 2 h hypoxia in response to (-)-noradrenaline stimulation. This second messenger response and the rightward shift of the (-)-noradrenaline displacement curve suggests that after 2 h hypoxia there is a decrease in agonist affinity for the alpha 1 adrenoceptor consistent with uncoupling of the alpha 1 adrenoceptor from its effector.

A fluorinated 2-nitroimidazole, KU-2285, as a new hypoxic cell radiosensitizer.

To develop new hypoxic cell radiosensitizers, we incorporated fluorine atoms into the side chain of the 2-nitroimidazole. Of the resulting compounds, KU-2285 (a 2-nitroimidazole with an N1-substituent of CH2CF2CONHCH2-CH2OH) was considered the most useful as a hypoxic cell radiosensitizer. In this study, its in vivo radiosensitizing activity and acute toxicity were compared with those of etanidazole. The reduction potentials of KU-2285 and etanidazole were -0.96 V and -1.05 V vs Ag/Ag+ in N,N-dimethylformamide, respectively, and their respective octanol/water partition coefficients were 0.25 and 0.040. The in vivo radiosensitizing activity of KU-2285 was found to be similar to that of etanidazole at the same administration dose when assayed by an in vivo-in vitro assay, a growth delay assay, and a tumor control assay using SCC VII tumor or transplanted mammary tumor in C3H/He mice. Although the radiosensitizing activity of etanidazole was reduced when it was administered orally, there was no significant difference in the radiosensitizing activity of KU-2285 whether it was administered intravenously, intraperitoneally, or orally. The acute toxicity measured as the LD50/7 in 8-week-old female C3H/HeJ mice was found to be 2.4 g/kg (intravenously), 2.1 g/kg (intraperitonealy), and 4.25 g/kg (orally) for KU-2285, whereas it was 4.75 g/kg (intravenously) for etanidazole.

Detrimental effects of beta-adrenergic stimulation on beta-adrenoceptors and microtubules in the heart.

Increased plasma catecholamines - in particular, excessive beta-adrenoceptor activation in chronic heart failure - may easily desensitize the beta-adrenoceptors as well as the postreceptor signal transductions. Since these detrimental changes in the failing heart could be reversible, administration of low-dose beta-blocker, which minimizes the negative inotropic effects, may be effective in attenuating the harmful effects of sympathetic nerve activation. Beta-adrenoceptor stimulation may also produce microtubule disruptions of the cell either through direct action or through an increase in heart rate. Treatment with beta-blockers could attenuate Ca overload by slowing the heart rate and may be useful as a protection from the structural disintegration of the cell. Thus, to clarify the underlying mechanisms of beta-blocker therapy for chronic heart failure, we have to consider not only to the functional aspects but also to the structural changes of the cells.

Role of increased alpha 1-adrenergic activity in cardiomyopathic Syrian hamster.

We investigated serial changes in myocardial norepinephrine content and myocardial adrenergic receptors during the development of cardiomyopathy in Syrian hamsters (Bio 14.6) and their age-matched healthy controls. We also examined phosphatidylinositide hydrolysis after alpha 1-adrenergic stimulation and the effects of alpha 1-blockade. We found that in the prehypertrophic stage, myocardial norepinephrine content and densities of alpha 1- and beta-adrenergic receptors were significantly higher in the cardiomyopathic hamsters than in the controls. However, in the early heart failure stage, beta-receptor density was 28% lower than that of the age-matched controls, although alpha 1-receptor density remained 55% higher. Norepinephrine-stimulated phosphatidylinositide hydrolysis in the cardiomyopathic hamster in the hypertrophic stage was twice that in the controls, indicating that the increase in alpha 1-adrenergic receptors is coupled with the intracellular signal transduction. Furthermore, selective alpha 1-adrenoceptor blockade by bunazosin in the cardiomyopathic hamsters from 70 to 170 days of age reduced myocardial hypertrophy and focal myocardial necrosis. Thus we conclude that increased alpha 1-adrenergic activity plays an important role in progression of cardiac hypertrophy is cardiomyopathic Syrian hamsters.

The role of Na+/H+ exchange in norepinephrine-induced protein synthesis in neonatal cultured rat cardiomyocytes.

It is reported that Na+ influx contributes to stretch-induced cardiac hypertrophy. Na+ influx may also be involved in cardiac hypertrophy induced by catecholamine. In the present study, to test whether Na+/H+ exchange plays an important role in norepinephrine-induced cardiac hypertrophy, the effect of Na+/H+ exchange inhibitor, amiloride on protein synthesis was studied in cultured neonatal rat cardiomyocytes in serum free medium. [3H]Phenylalanine uptake was determined 24 and 48 hours after administration of norepinephrine with and without amiloride. In the control, norepinephrine increased [3H]phenylalanine uptake in a dose dependent manner (10(-5)-10(-7) M). Prazosin (10(-7) M) and amiloride (10(-5)-10(-4) M) significantly attenuated the norepinephrine mediated protein synthesis. These results indicate that alpha 1-adrenergic stimulation enhances the protein synthesis through activation of Na+/H+ exchange. Therefore, Na+ influx and/or PH increase may play a key role in cardiac hypertrophy.

Effects of pertussis toxin on alpha 1-agonist-mediated phosphatidylinositide turnover and myocardial cell hypertrophy in neonatal rat ventricular myocytes.

In neonatal rat ventricular myocytes pretreatment with pertussis toxin did not affect 1 microM (-)-norepinephrine stimulation of inositol phosphates or myocardial cell hypertrophy as measured either by protein radiolabelling or by myocardial cell protein content. Thus guanine nucleotide protein(s) ADP-ribosylated by pertussis toxin do not play a role in two alpha 1-adrenoceptor-mediated processes, phosphatidylinositide turnover and induction of myocardial cell hypertrophy.

A new, potent 2-nitroimidazole nucleoside hypoxic cell radiosensitizer, RP170.

The radiosensitizing activity, acute toxicity and pharmacokinetics of RP170, a new hypoxic cell radiosensitizer, were compared with those of misonidazole (MISO) and SR2508. RP170 belongs to the group of 2-nitroimidazole nucleosides, which are designed to be selectively excluded from the neural tissue. The reduction potential of RP170 was similar to that of MISO and SR2508. The partition coefficients in octanol/water of RP170, MISO, and SR2508 were 0.094, 0.35, and 0.021, respectively. The radiosensitizing activity of RP170 was similar to that of MISO and SR2508 in vitro and in vivo. There was no significant difference in the radiosensitizing activity of RP170 in vivo between intravenous and intraperitoneal administration. The acute toxicity of RP170 was the same as that of SR2508. Pharmacokinetic evaluation showed that the concentration of RP170 in the brain was as low as that of SR2508. RP170 is expected to have the same radiosensitizing effects as MISO and SR2508, and to be less neurotoxic than MISO.