Design and synthesis of chromone-nitrogen mustard derivatives and evaluation of anti-breast cancer activity

Chromone has emerged as one of the most important synthetic scaffolds for antitumor activity, which promotes the development of candidate drugs with better activity. In this study, a series of nitrogen mustard derivatives of chromone were designed and synthesised, in order to discover promising anti-breast tumour candidates. Almost all target derivatives showed antiproliferative activity against MCF-7 and MDA-MB-231 cell lines. In particular, methyl (S)-3-(4-(bis(2-chloroethyl)amino)phenyl)-2-(5-(((6-methoxy-4-oxo-4H-chromen-3-yl)methyl)amino)-5-oxopentanamido)propanoate showed the most potent antiproliferative activity with IC₅₀ values of 1.83 and 1.90 μM, respectively, and it also exhibited certain selectivity between tumour cells and normal cells. Further mechanism exploration against MDA-MB-231 cells showed that it possibly induced G2/M phase arrest and apoptosis by generating intracellular ROS and activating DNA damage. In addition, it also inhibited MDA-MB-231 cells metastasis, invasion and adhesion. Overall, methyl (S)-3-(4-(bis(2-chloroethyl)amino)phenyl)-2-(5-(((6-methoxy-4-oxo-4H-chromen-3-yl)methyl)amino)-5-oxopentanamido)propanoate showed potent antitumor activities and relatively low side effects, and deserved further investigation.     

Synthesis of Triazole Schiff’s Base Derivatives and Their Inhibitory Kinetics on Tyrosinase Activity

In the present study, new Schiff’s base derivatives: (Z)-4-amino-5-(2-(3- fluorobenzylidene)hydrazinyl)-4H-1,2,4-triazole-3-thiol (Y₁), (Z)-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y₂), (Z)-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y₃) and 3-((Z)-(2-(4- (((E)-3-hydroxybenzylidene)amino)-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y₄) were synthesized and their structures were characterized by LC-MS, IR and ¹H NMR. The inhibitory effects of these compounds on tyrosinase activites were evaluated. Compounds Y₁, Y₂ and Y₃ showed potent inhibitory effects with respective IC₅₀ value of 12.5, 7.0 and 1.5 μM on the diphenolase activities. Moreover, the inhibition mechanisms were determined to be reversible and mixed types. Interactions of the compounds with tyrosinase were further analyzed by fluorescence quenching, copper interaction, and molecular simulation assays. The results together with the anti-tyrosinase activities data indicated that substitution on the second position of benzene ring showed superior ant-ityrosinase activities than that on third position, and that hydroxyl substitutes were better than fluorine substitutes. In addition, two benzene rings connecting to the triazole ring would produce larger steric hindrance, and affect the bonding between tyrosinase and inhibitors to decrease the inhibitory effects. The anti-tyrosinase effects of these compounds were in contrast to their antioxidant activities. In summary, this research will contribute to the development and design of antityrosinase agents.     

Impact of age on breathing and resistive pressure in people with and without sleep apnea.

We investigated the effect of age on breathing and total pulmonary resistance (RL) during sleep by studying elderly (>65 yr) and young (25-38 yr) people without sleep apnea (EN and YN, respectively) matched for body mass index (BMI). To determine the impact of sleep apnea on age-related changes in breathing, we studied elderly and young apneic patients (EA and YA, respectively) matched for apnea and BMI. In all groups (n = 11), breathing during periods of stable sleep was analyzed to evaluate the intrinsic variability of respiratory control mechanisms. In the absence of sleep apnea, the variability of the breathing was similar in the elderly and young [mean (+/- SD) coefficient of variation (CV) of tidal volume (VT); wake: EN 21.0 +/- 14.9%, YN 14.7 +/- 5.5%; sleep: EN 14.0 +/- 6.0%; YN 11.5 +/- 6.4%]. In patients with sleep apnea, breathing during stable sleep was more irregular, but there were no age-related differences (CV of VT; wake: EA 22.0 +/- 11.6%, YA 16.7 +/- 11.3%; sleep: EA 32.8 +/- 24.9%, YA 25.2 +/- 16.3%). In addition, EN tended to have a higher RL (n = 6, RL midinspiration, wake: EN 7.1 +/- 3.0; YN 9.1 +/- 6.4 cmH(2)O. l(-1). s, sleep: EN 17.5 +/- 11.7; YN 9.8 +/- 2.0 cmH(2)O. l(-1). s). We conclude that aging per se does not contribute to the intrinsic variability of respiratory control mechanisms, although there may be a lower probability of finding elderly people without respiratory instability.     

The effect of different extenders on post-thaw sperm survival, acrosomal integrity and longevity in cryopreserved semen of Formosan Sika deer and Formosan Sambar deer

This study investigates the efficacy of five extenders in contributing to the outcome of semen cryopreservation in Formosan Sika and Sambar deer. Pooled semen (n=4) of six males of each breed was used. In Sika deer, semen collection rate was 96% (23/24) over all electro-ejaculations. Volume, sperm motility and sperm concentration of fresh ejaculates was 0.5+/-0.4 ml, 77+/-6% and 1471.3+/-940.0 x 10(6) ml(-1), respectively. Post-thaw motility in respective extender was A: 66+/-16%; B: 71+/-2%; C: 73+/-6%; D: 9+/-4% and E: 26+/-12% (mean+/-S.D.). In extender C (74+/-14%) more viable spermatozoa were preserved than in the others (A: 64+/-10%; B: 48+/-11%; D: 41+/-16%; E: 47+/-6%; P<0.05). Acrosomal integrity was not influenced by extender composition. Post-thaw motility did not decrease during a 4-h incubation period, irrespective of the extender used (P>0.05). In Sambar deer, semen collection rate was 88% (21/24) over all electro-ejaculations. Volume, sperm motility and sperm concentration of fresh ejaculates was 1.3+/-0.5 ml, 82+/-4% and 379.1+/-252.2 x 10(6) ml(-1), respectively. Post-thaw motility was in respective extenders A: 69+/-2%; B: 74+/-6%; C: 73+/-2%; D: 13+/-6% and E: 31+/-20%. Extenders B and C were superior (P>0.05) with respect to sperm motility. Similarly, post-thaw viability in extenders A (70+/-7%), B (76+/-7%) and C (79+/-2%) was higher than that D (25+/-19%) and E (29+/-17%) (P<0.01). Sperm acrosomal integrity was better preserved in extenders B (86+/-4%) and C (83+/-4%) than in extenders A (54+/-13%), D (39+/-22%) and E (46+/-22%) (P<0.05). Post-thaw sperm longevity in extender A reduced from 69 to 16% during incubation (P<0.05) whereas only a slight decrease was observed in the other extenders after 4 h. In conclusion these data show that egg-yolk-Tris-Tes-glycerol based extender C containing Equex STM paste is optimal for freezing semen of Formosan Sika deer while egg-yolk-Tris-citric acid-glycerol based extender B containing Equex and extender C are superior in semen cryopreservation to others for Formosan Sambar deer.     

Comparison of estrogen concentrations, estrone sulfatase and aromatase activities in normal, and in cancerous, human breast tissues

In the present study, the concentrations of estrone (E(1)), estradiol (E(2)) and their sulfates (E(1)S and E(2)S), as well as the sulfatase and aromatase activities, were evaluated in post-menopausal patients with breast cancer. Comparative studies of the evaluation of these parameters were carried out in (a) tumor tissue, (b) areas surrounding the tumor, and (c) areas distant from the tumor (glandular tissue) which were considered as normal tissue. The levels (in pm/g; mean +/- SEM) were: for E(1) in the (a) area: 320+/-95; in (b): 232+/-86; and in (c): 203+/-71; for E(2) in the (a) area: 388+/-106; in (b): 224+/-48; and in (c): 172+/-80; for E(1)S in the (a) area: 454+/-110; in (b): 259+/-90; and in (c): 237+/-65; for E(2)S in the (a) area:318+/-67; in (b): 261+/-72; and in (c): 232+/-75, respectively. The values of E(1)S and E(2) were significantly higher in the tumor tissue than in the area considered as normal. In all the tissues studied, the sulfatase activity was much higher than aromatase (130-200). In addition, the sulfatase levels were significantly higher in the peripheral and in the tumor tissue than in the area considered as normal. The levels of aromatase were significantly higher in tumoral than in normal tissue. The present data extend the "intracrine concept" for breast cancer tumors. The physiopathology and clinical significance as promoter parameters in breast cancer is to be explored.     

The differential effects of galanin-(1-30) and -(3-30) on anterior pituitary hormone secretion in vivo in humans

Intravenous injection of galanin increases plasma growth hormone (GH) and prolactin (PRL) concentrations. In the rat, the effects of galanin on GH appear to be mediated via the hypothalamic galanin receptor GAL-R(1), at which galanin-(3-29) is inactive. In contrast, the effect of galanin on PRL is mediated via the pituitary-specific galanin receptor GAL-R(W), at which galanin-(3-29) is fully active. We investigated the effects of an intravenous infusion of human galanin (hGAL)-(1-30) and -(3-30) on anterior pituitary hormone levels in healthy females. Subjects were infused with saline, hGAL-(1-30) (80 pmol. kg(-1). min(-1)), and hGAL-(3-30) (600 pmol. kg(-1). min(-1)) and with boluses of gonadotropin-releasing hormone, thyrotropin-releasing hormone, and growth hormone-releasing hormone (GHRH). Both hGAL-(1-30) and -(3-30) potentiated the rise in GHRH-stimulated GH levels [area under the curve (AUC), saline, 2,810 +/- 500 vs. hGAL-(1-30), 4,660 +/- 737, P < 0.01; vs. hGAL-(3-30), 6, 870 +/- 1,550 ng. min. ml(-1), P < 0.01]. In contrast to hGAL-(1-30), hGAL-(3-30) had no effect on basal GH levels (AUC, saline, -110 +/- 88 vs. hGAL 1-30, 960 +/- 280, P < 0.002; vs. hGAL-(3-30), 110 +/- 54 ng. min. ml(-1), P = not significant). These data suggest that the effects of galanin on basal and stimulated GH release are mediated via different receptor subtypes and that the human equivalent of GAL-R(W) may exist.     

Effect of regional hyperemia on myocardial uptake of 2-deoxy-2-[(18)F]fluoro-D-glucose

2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) may be used to predict glucose kinetics when the factor relating differences in transport and phosphorylation between compounds remains constant ("lumped constant"). It is not clear whether hyperemia alters that factor. In anesthetized swine, myocardial FDG uptake was estimated by positron emission tomography, during an intracoronary infusion of either adenosine, ATP, or bradykinin (40 microg x kg(-1) x min(-1), 40 microg x kg(-1) x min(-1), and 2 nmol x kg(-1) x min(-1), respectively; n = 6 for all groups). In controls during normal perfusion (n = 6), FDG uptake was 0.78 +/- 0.32 micromol x g(-1) x min(-1), whereas glucose uptake by Fick was 0.71 +/- 0.25 micromol x g(-1) x min(-1) (r = 0.73; P < 0.05). Adenosine increased blood flow from 1.29 +/- 0.43 to 4.80 +/- 2.19 ml x g(-1) x min(-1) (P < 0.05) and glucose uptake from 1.16 +/- 1.10 to 3.35 +/- 2.12 micromol x g(-1) x min(-1) (P < 0.05), whereas FDG uptake in the hyperemic region was lower than remote regions (0.46 +/- 0.29 and 0.95 +/- 0.55 micromol x g(-1) x min(-1), respectively; P < 0.05). In the ATP and bradykinin groups, blood flow increased four- and twofold, respectively, with no net change in glucose uptake. FDG uptake in the hyperemic region was also significantly lower than remote regions. For all animals, the ratio of blood flow in the hyperemic region relative to remote region was inversely proportional to the ratio of FDG uptake in the same regions (r(2)=0.73; P < 0.001). Because nitric oxide elaboration during hyperemia could potentially alter substrate preference and FDG kinetics, six additional swine were studied during maximal adenosine before and after intracoronary N(G)-monomethyl-L-arginine (1.5 mg/kg). Inhibition of nitric oxide had no effect on either regional myocardial substrate uptake or FDG accumulation. In conclusion, hyperemia decreased regional myocardial FDG uptake relative to normally perfused regions and this effect on the lumped constant was independent of nitric oxide.     

Synthesis,Biological Evaluation and in Silico Studies of 3-Hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide Derivatives

In the present study, a series of 3-hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide derivatives were synthesized, characterized and evaluated for theirin vitroactivity, i. e., antimicrobial, antioxidant and anti-inflammatory. The target compounds were synthesized by condensation reaction of 3-hydroxy-2-naphthoic acid hydrazide with substituted benzaldehydes which were subjected to cyclization reaction with thioglycolic acid and ZnCl₂ to get target compounds. The synthesized 3-hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide derivatives were examined for their antimicrobial activity and 3-hydroxy-N-(4-oxo-2-(3,4,5-trimethoxyphenyl)thiazolidin-3-yl)-2-naphthamide ( S20 ) exhibited the highest antimicrobial potential. The N′-(2,3-dichlorobenzylidene)-3-hydroxy-2-naphthohydrazide ( S5 ) displayed good antifungal potential against Rhizopus oryzae, whereas N′-(2,3-dichlorobenzylidene)-3-hydroxy-2-naphthohydrazide ( S20 ) showed the highest antioxidant potential and N-(2-(2,6-dichlorophenyl)-4-oxothiazolidin-3-yl)-3-hydroxy-2-naphthamide ( S16 ) displayed the highest anti-inflammatory activity. The results of molecular docking studies revealed that existence of hydrogen bonding and hydrophobic interactions with their respective proteins. In silico ADMET studies were carried out by Molinspiration, Pre-ADMET and OSIRIS property explorer to predict the pharmacokinetic behaviour of synthesized 3-hydroxy-N-(2-(substituted phenyl)-4-oxothiazolidin-3-yl)-2-napthamide derivatives.     

Oxytocin (OT) action in uterine tissues of cyclic and early pregnant gilts: OT receptors concentration, prostaglandin F(2)alpha secretion, and phosphoinositide hydrolysis

Oxytocin (OT) is involved in the regulation of luteolysis in pigs. However, it is still not clear if OT is responsible for initiation of luteal regression in this species. The objectives of the study were: (1) to compare OT receptors (OTr) concentrations in endometrium and myometrium of cyclic and early pregnant pigs, (2) to examine the effect of OT on plasma PGF(2)alpha secretion during the progressive luteal regression, (3) to ascertain the effect of OT on inositol phosphates (IPs) accumulation in endometrial and myometrial cells of cyclic and early pregnant pigs. Concentrations of OTr on the endometrium and myometrium of cyclic (n = 33) (days 2-4; 11-13; 14-16; 18-20; day 21) and early pregnant (n = 4) (days 14-16) gilts were determined and they ranged from 7 +/- 3 (days 11-13) to 377 +/- 113 fmol/mg protein (day 21) in the endometrium and from 33 +/- 11 (days 2-4) to 167 +/- 28 fmol/mg protein (days 18-20) in the myometrium. In both tissues, concentrations of OTr were low during the luteal phase and increased (P < 0.01) during the follicular phase. In contrast to myometrial OTr, endometrial OTr during pregnancy were undetectable. In next experiment, mature gilts (n = 12) were injected with OT (20IU; i.v.) for three consecutive days starting on days 14 and 15 of the oestrous cycle and plasma PGF(2)alpha metabolite-13,14-dihydro-16-keto PGF(2)alpha (PGFM) concentration was determined. On days 15-16 and 16-17, OT increased plasma PGFM level. This effect was not observed on days 14-15 of the estrous cycle. A negative correlation was noticed between plasma concentrations of PGFM and progesterone (r = -0.3; P < 0.05). In last experiment, OT (100 nM) augmented (P < 0.01) an accumulation of inositol phosphates (IPs) in isolated myometrial cells on days 14-16 (n = 4) and 18-20 (n = 3) of the estrous cycle and on days 14-16 (n = 4) of pregnancy. Oxytocin-stimulated accumulation of IPs was not observed in endometrial cells. In summary: (1) concentrations of OTr on both the endometrium and myometrium were the highest during perioestrus-period in pigs, (2) myometrium of early pregnant sows possessed functional OTr, (3) oxytocin increased plasma PGFM concentration after initiation of luteolysis; and (4) OT-stimulated accumulation of IPs in myometrial, but not in endometrial cells. In conclusion, OT appears to not be involved in the initiation of luteal regression in sows and functional OTr are still present in the myometrium during early pregnancy (days 14-16).     

The inhibitory mechanism of Cu(II) on the Photosystem II electron transport from higher plants

In a previous paper, we reported that Cu(II) inhibited the photosynthetic electron transfer at the level of the pheophytin-Q_A-Fe domain of the Photosystem II reaction center. In this paper we characterize the underlying mechanism of Cu(II) inhibition. Cu(II)-inhibition effect was more sensitive with high pH values. Double-reciprocal plot of the inhibition of oxygen evolution by Cu(II) is shown and its corresponding inhibition constant, K_i, was calculated. Inhibition by Cu(II) was non-competitive with respect to 2,6-dichlorobenzoquinone and 3-(3,4-dichlorophenyl)-1,1-dimethylurea and competitive with respect to protons. The non-competitive inhibition indicates that the Cu(II)-binding site is different from that of the 2,6-dichlorobenzoquinone electron acceptor and 3-(3,4-dichlorophenyl)-1,1-dimethylurea sites, the Q_B niche. On the other hand, the competitive inhibition with respect to protons may indicate that Cu(II) interacts with an essential amino acid group(s) that can be protonated or deprotonated in the inhibitory-binding site.Abbreviations BSA bovine seroalbumin - Chl chlorophyll - DCBQ 2,6-dichlorobenzoquinone - DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - MES 2-(N-morpholino)-ethanesulphonic acid - Pheo pheophytin - Q_A primary quinone acceptor - Q_B secondary quinone acceptor - PS Photosystem - RC reaction center - Tricine N-[Tris(hydroxymethyl)-methyl]-glycine     

Decreased fractional urinary calcium excretion and serum 1,25-dihydroxyvitamin D and IGF-I levels in preeclampsia

During preeclampsia several alterations of calcium metabolism have been described, the most common of them is hypocalciuria, which pathophysiology is still unclear. In order to assess the contribution of calciotropic hormones to urinary calcium excretion, a cross-sectional study was done including 26 preeclamptic Mexican women (PE group) and 26 normotensive control pregnant women (NT group). Total and fractional urinary calcium excretion were significantly lower (P<0.0001) in the PE group than in the NT group (82+/-7 versus 171+/-7 mg/24h and 0.62+/-0.38 versus 1.38+/-0.71%, respectively), without significant differences in creatinine clearance, urinary sodium excretion and phosphate tubular reabsorption. In addition, serum 1,25-(OH)(2)D and IGF-I levels were significantly (P<0.05) lower in the PE than in NT group (43+/-9 versus 50+/-9 pg/mL and 195+/-67 versus 293+/-105 ng/mL, respectively), without significant differences in serum PTH levels. In the NT group, association analysis showed that total and fractional urinary calcium excretions positively correlated with serum levels of 1,25-(OH)(2)D (P<0.01) and IGF-I (P<0.001). In the PE group, total urinary calcium excretion positively correlated only with serum 1,25-(OH)(2)D (P<0.05). In conclusion, the results obtained in this study confirm that PE is associated with hypocalciuria and suggest that 1,25-(OH)(2)D and/or IGF-I may be involved in the regulation of urinary calcium excretion.     

The ruthenium complex <Emphasis Type="Italic">cis</Emphasis>-(dichloro)tetrammineruthenium(III) chloride induces apoptosis and damages DNA in murine sarcoma 180 cells

Ruthenium(III) complexes are increasingly attracting the interest of researchers due to their promising pharmacological properties. Recently, we reported that the cis-(dichloro)tetrammineruthenium(III) chloride compound has cytotoxic effects on murine sarcoma 180 (S-180) cells. In an effort to understand the mechanism responsible for their cytotoxicity, study we investigated the genotoxicity, cell cycle distribution and induction of apoptosis caused by cis-(dichloro)tetrammineruthenium(III) chloride in S-180 tumour cells. cis-(dichloro)tetrammineruthenium(III) chloride treatment induced significant DNA damage in S-180 cells, as detected by the alkaline comet assay. In the cell cycle analysis, cis-(dichloro)tetrammineruthenium(III) chloride caused an increase in the number of cells in G1 phase, accompanied by a decrease in the S and G2 phases after 24 h of treatment. In contrast, the cell cycle distribution of S-180 cells treated with cis-(dichloro)tetrammineruthenium(III) chloride for 48 h showed a concentration-dependent increase in the sub-G1 phase (indicating apoptosis), with a corresponding decrease in cells in the G1, S and G2 phases. In addition, cis-(dichloro)tetrammineruthenium(III) chloride treatment induced apoptosis in a time-dependent manner, as observed by the increased numbers of annexin V-positive cells. Taken together, these findings strongly demonstrate that DNA damage, cell cycle changes and apoptosis may correlate with the cytotoxic effects of cis-(dichloro)tetrammineruthenium(III) chloride on S-180 cells.     

Sympathetic, sensory, and nonneuronal contributions to the cutaneous vasoconstrictor response to local cooling

Previous work indicates that sympathetic nerves participate in the vascular responses to direct cooling of the skin in humans. We evaluated this hypothesis further in a four-part series by measuring changes in cutaneous vascular conductance (CVC) from forearm skin locally cooled from 34 to 29 degrees C for 30 min. In part 1, bretylium tosylate reversed the initial vasoconstriction (-14 +/- 6.6% control CVC, first 5 min) to one of vasodilation (+19.7 +/- 7.7%) but did not affect the response at 30 min (-30.6 +/- 9% control, -38.9 +/- 6.9% bretylium; both P < 0.05, P > 0.05 between treatments). In part 2, yohimbine and propranolol (YP) also reversed the initial vasoconstriction (-14.3 +/- 4.2% control) to vasodilation (+26.3 +/- 12.1% YP), without a significant effect on the 30-min response (-26.7 +/- 6.1% YP, -43.2 +/- 6.5% control; both P < 0.05, P > 0.05 between sites). In part 3, the NPY Y1 receptor antagonist BIBP 3226 had no significant effect on either phase of vasoconstriction (P > 0.05 between sites both times). In part 4, sensory nerve blockade by anesthetic cream (Emla) also reversed the initial vasoconstriction (-20.1 +/- 6.4% control) to one of vasodilation (+213.4 +/- 87.0% Emla), whereas the final levels did not differ significantly (-37.7 +/- 10.1% control, -37.2 +/- 8.7% Emla; both P < 0.05, P > 0.05 between treatments). These results indicate that local cooling causes cold-sensitive afferents to activate sympathetic nerves to release norepinephrine, leading to a local cutaneous vasoconstriction that masks a nonneurogenic vasodilation. Later, a vasoconstriction develops with or without functional sensory or sympathetic nerves.     

Molecular and biochemical features of poly (ADP-ribose) metabolism

In the past five years, poly(ADP-ribosyl)ation has developed greatly with the help of molecular biology and the improvement of biochemical techniques. In this article, we describe the physico-chemical properties of the enzymes responsible for the synthesis and degradation of poly(ADP-ribose), respectively poly(ADP-ribose) polymerase and poly(ADP-ribose) glycohydrolase. We then discuss the possible roles of this polymer in DNA repair and replication as well as in cellular differentiation and transformation. Finally, we put forward various hypotheses in order to better define the function of this polymer found only in eucaryotes. (Mol Cell Biochem122: 171–193, 1993)Abbreviations 3-AB 3-Aminobenzamide - 3-MBA 3-Methoxybenzamide - AADH Amino Acid Dehydrogenase - CAT Chloramphenicol Acetyl Transferase - DHFR Dihydrofolate Reductase - DMS Dimethylsulfate - DMSO Dimethylsulfoxide - DNase Deoxyribonuclease - HMG High Mobility Group - kb Kilobase - kDa Kilodalton - LMG Low Mobility Group - MNNG Methylnitroso Nitroguanidine - MNU Methylnitrosourea - NAD Nicotinamide Adenine Dinucleotide - NLS Nuclear Localization System - NTP Nucleotide Triphosphate - pADPR Poly (ADP-ribose) - PARP Poly(ADP-ribose) Polymerase - PHA Phytohemaglutinin - PMA Phorbol Myristate Acetate - PRAMP Phosphoribosyl AMP - (PR)₂AMP Diphosphoribosyl AMP - RNase Ribonuclease - SCE Sister Chromatid Exchange - TPA Tetradecanoyl Phorbol-13-Acetate - UV Ultra-Violet     

Design and synthesis of novel 1-phenyl-3-(5-(pyrimidin-4-ylthio)-1,3,4-thiadiazol- 2-yl)urea derivatives with potent anti-CML activity throughout PI3K/AKT signaling pathway

In this investigation, a series of 1-phenyl-3-(5-(pyrimidin-4-ylthio)-1,3,4- thiadiazol-2-yl)urea receptor tyrosine kinase inhibitors were synthesized by a simple and efficient structure-based design. Structure-activity relationship (SAR) analysis of these compounds based on cellular assays led to the discovery of a number of compounds that showed potent activity against human chronic myeloid leukemia (CML) cell line K562, but very weak or no cellular toxicity through monitoring the growth kinetics of K562 cell during a period of 72 h using the real-time live-cell imaging. Among these compounds, 1-(5-((6-((3-morpholinopropyl) amino)pyrimidin-4-yl)thio)-1,3,4-thiadiazol-2-yl)-3-(4-(trifluoromethyl)phenyl)urea (7) exhibited the least cellular toxicity and better biological activity in cellular assays (K562, IC₅₀: 0.038 μM). Compound 7 also displayed very good induced-apoptosis effect for human CML cell line K562 and exerted its effect via a significantly reduced protein phosphorylation of PI3K/Akt signal pathway by Human phospho-kinase array analysis. In vitro results indicate that 1-phenyl-3-(5-(pyrimidin-4-ylthio)-1,3,4- thiadiazol-2-yl)urea derivatives are lead molecules for further development as treatment of chronic myeloid leukemia and cancer.     

Comparison of some reproductive characteristics of farmed and wild white shrimp males Litopenaeus vannamei (Decapoda: Penaeidae)

We rated some reproductive characteristics of white shrimp Litopenaeus vannamei (Boone, 1931) males using 46 farmed individuals (weighing 21.42 +/- 0.56 g) and 40 wild individuals (weighing 36.10 +/- 0.72 g). In farmed shrimps, spermatophore mean weight was 8.94 +/- 0.51 mg; total mean sperm count was 3.90 +/- 0.27 x 10(6) in each spermatophore; and mean percentage of normal sperm was 86.9 +/- 0.37%. In wild individuals, the respective values were 30.68 +/- 2.32 mg; 6.22 +/- 1.09 x 10(6); and 62.1 +/- 3.56%. In both groups, the differences between right and left spermatophore were not significant (p < 0.01). There were significant differences in spermatophore weight and percentage of normal sperm between farmed and wild shrimps; sperm counts differences, however, were not significant (p < 0.01). The relationship between spermatophore weight (Ws) and individual weight (Wo) was Ws (mg)=1.23 (Wo)-17.34 (r2=0.89), in farmed shrimps; and Ws (mg) = 2.57 (Wo)-60.04 (r2 = 0.64), in wild ones. In cultivated organisms, the relationship between sperm counts (Cs) and individual weight (Wo) was Cs (x 10(6)) = 1.13 * 10(-4*) (Wo) 3.361 (r2 = 0.85); and versus spermatophores weight was Cs (x 10(6)) = 0.439* (Ws) 0.984 (r2 = 0.90). In wild organisms, there was no correlation. The proportion of normal sperm ranged from 79.8 to 95.2 % (86.9 +/- 0.37%) and from 14.0 to 91.5% (62.1 +/- 2.52%), in farmed and wild shrimps, respectively. The most frequent abnormalities in both farm and wild animals were sperm without spike (49.3% and 76.6%, respectively) and irregular shape (35.8 % and 17.7 %). The less frequent occurrences were those of bent (10.2 % and 4.29%) and double spike (4.7% and 1.41%).     

Synthesis and cytokinin activity of (R)-(+)- and (S)-(−)-dihydrozeatins and their ribosides

(R)-(+)- and (S)-(?)-dihydrozeatins [(R)-(+)- and (S)-(?)-6-(4-hydroxy-3-methylbutylamino)purines, 1a and 1b] and their ribosides {(?)-6-[(R)-4-hydroxy-3-methylbutylamino]- and (?)-6-[(S)-4-hydroxy-3-methyl-butylamino]-9-β-D-ribofuranosylpurines, 3a and 3b} were synthesized and tested for their cytokinin activity by four bioassay systems, the growth of tobacco callus, the seed germination of lettuce, the fr. wt increase of excised radish cotyledons and the retardation of chlorophyll degradation in radish cotyledons. In tobacco callus bioassay, 1a was more active than 1b. The ribosides 3a and 3b were not less active than their corresponding aglycones 1a and 1b. In other bioassays used the activity followed the order: 1a >3a >1b >3b. In tobacco callus bioassay and lettuce seed germination, trans-zeatin [6-(4-hydroxy-3-methylbut-trans-2-enylamino)purine] showed stronger cytokinin activity than 1a.     

Synthesis,biological activity and multiscale molecular modeling studies of bis-coumarins as selective carbonic anhydrase IX and XII inhibitors with effective cytotoxicity against hepatocellular carcinoma

A series of novel bis-coumarin derivatives containing triazole moiety as a linker between the alkyl chains was synthesized and their inhibitory activity against the human carbonic anhydrase (hCA) isoforms I, II, IX and XII were evaluated. In addition, cytotoxic effects of the synthesized compounds on renal adenocarcinoma (769P), hepatocellular carcinoma (HepG2) and breast adeno carcinoma (MDA-MB-231) cell lines were examined. While the hCA I and II isoforms were inhibited in the micromolar range, the tumor-associated isoform hCA IX and XII were inhibited in the high nanomolar range. 4-methyl-7-((1-(12-((2-oxo-2H-chromen-7-yl)oxy)dodecyl)-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (5p) showed the strongest inhibitory activity against hCA IX with the K_i of 144.6 nM and 4-methyl-7-((1-(10-((2-oxo-2H-chromen-7-yl)oxy)decyl)-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (5n) exhibited the highest hCA XII inhibition with the K_i of 71.5 nM. In order to better understand the inhibitory profiles of studied molecules, multiscale molecular modelling approaches were applied. Low energy docking poses of studied molecules at the binding sites of targets have been predicted. In addition, electrostatic potential surfaces (ESP) for binding sites were also generated to understand interactions between proteins and active ligands.     

Beta-blockade does not improve orthostatic intolerance induced by 20 days bed rest

To assess if propranolol influences orthostatic intolerance induced by prolonged bed rest (BR), a lower body negative pressure test (LBNP) and left ventricular (LV) echocardiography before and during -40mmHg of LBNP were performed with and without intravenous propranolol administration (0.04mg/kg) in 9 healthy volunteers (mean age: 21 years) before and after 20 days BR. LBNP tolerance time (LBNP-T), endpoint heart rate(HR), and percentage changes from 0 to -40mmHg LBNP in HR, LV diastolic dimension(LVDd), stroke volume (SV), cardiac output (CO), and systemic vascular resistance(SVR) were measured. After BR, percentage changes in CO during LBNP was not altered by propranolol (-12+/-21% vs. -24+/-24%; with and without propranolol; p>0.05) because the effect on percentage changes in HR (18+/-11% vs. 26+/-12%; p<0.05) cancelled out the effects of percentage changes in LVDd (-9+/-6% vs. -15+/-10%; p<0.05) and percentage changes in SV (-26+/-16% vs. -39+/-22%; p<0.05). In addition, propranolol decreased end-point HR (85+/-15bpm vs. 119+/-l4bpm; p<0.05) and percentage changes in SVR (25+/-32% vs. 53+/-57%; p<0.05). As a result, LBNP-T after BR was unchanged by propranolol (8.8+/-3.3min vs. 10.8+/-5.0min; p>0.05). In conclusion, propranolol failed to change orthostatic intolerance induced by BR.