Antiproliferative Potential of Olneya tesota PF2 Lectin in Human Acute Monocytic Leukemia Cells

Acute monocytic leukemia is a type of myeloid leukemia that develops in monocytes. The current clinical therapies for leukemia are unsatisfactory due to their side effects and nonspecificity toward target cells. Some lectins display antitumor activity and may specifically recognize cancer cells by binding to carbohydrate structures on their surface. Therefore, this study evaluated the response of the human monocytic leukemia cell lines THP-1 to the Olneya tesota PF2 lectin. The induction of apoptosis and reactive oxygen species production in PF2-treated cells was evaluated by flow cytometry, and the lectin-THP-1 cell interaction and mitochondrial membrane potential were evaluated by confocal fluorescence microscopy. PF2 genotoxicity was evaluated by DNA fragmentation analysis via gel electrophoresis. The results showed that PF2 binds to THP-1 cells, triggers apoptosis and DNA degradation, changes the mitochondrial membrane potential, and increases reactive oxygen species levels in PF2-treated THP-1 cells. These results suggest the potential use of PF2 for developing alternative anticancer treatments with enhanced specificity.     

Substance use disorders: a comprehensive update of classification,epidemiology, neurobiology,clinical aspects,treatment and prevention

Substance use disorders (SUDs) are highly prevalent and exact a large toll on individuals’ health, well-being, and social functioning. Long-lasting changes in brain networks involved in reward, executive function, stress reactivity, mood, and self-awareness underlie the intense drive to consume substances and the inability to control this urge in a person who suffers from addiction (moderate or severe SUD). Biological (including genetics and developmental life stages) and social (including adverse childhood experiences) determinants of health are recognized factors that contribute to vulnerability for or resilience against developing a SUD. Consequently, prevention strategies that target social risk factors can improve outcomes and, when deployed in childhood and adolescence, can decrease the risk for these disorders. SUDs are treatable, and evidence of clinically significant benefit exists for medications (in opioid, nicotine and alcohol use disorders), behavioral therapies (in all SUDs), and neuromodulation (in nicotine use disorder). Treatment of SUDs should be considered within the context of a Chronic Care Model, with the intensity of intervention adjusted to the severity of the disorder and with the concomitant treatment of comorbid psychiatric and physical conditions. Involvement of health care providers in detection and management of SUDs, including referral of severe cases to specialized care, offers sustainable models of care that can be further expanded with the use of telehealth. Despite advances in our understanding and management of SUDs, individuals with these conditions continue to be stigmatized and, in some countries, incarcerated, highlighting the need to dismantle policies that perpetuate their criminalization and instead develop policies to ensure support and access to prevention and treatment.     

Green mass aggregations of Gyrodinium cf. aureolum Hulburt in the Ria of Pontevedra (north-west Spain)

In this paper we report a bloom of Gyrodinium cf. aureolum occurringin an estuary of the north-west coast of Spain. It was sampledin late August 1989, in shallow waters 2 m deep in the Ria ofPontevedra. Its temperature was 19.5°C and salinity 35     

The deactivation pathways of the excited-states of the mycosporine-like amino acids shinorine and porphyra-334 in aqueous solution.

In vitro studies on the structurally related mycosporine-like amino acids (MAAs) porphyra-334 and shinorine in aqueous solutions were carried out aiming at their full photochemical and photophysical characterization and expanding the evidence on the assigned UV-photoprotective role of the molecules in vivo. The experiments on shinorine confirmed a high photostability and a poor fluorescence quantum yield, in concordance with previous results on porphyra-334. The estimation of triplet production quantum yields for both MAAs was achieved by laser-flash photolysis measurements. In particular, photosensitization experiments on porphyra-334 support the participation of the triplet state in the photodecomposition mechanism yielding a more precise value of [capital Phi](T). As well, photoacoustic calorimetry experiments allowed the first direct quantification of the nonradiative relaxation pathways of the excited MAAs in solution, corroborating that the vast majority (ca. 97%) of the absorbed energy is promptly delivered to the surroundings as heat, consistently with the low photodecomposition and emission yields observed.     

Evaluation of coupling conditions for the incorporation of Nα-Fmoc-Tyr(PO3H2)-OH in solid-phase peptide synthesis

Summary In order to minimise the formation of the pyrophosphate derivative of the target peptide when side-chain-unprotected phopshotyrosine is used in solid-phase peptide synthesis, this building block can be incorporated using benzotriazolyloxy-tris-(dimethylamino)phosphonium hexafluorophosphate/1-hydroxybenzotriazole/N-methylmorpholine (1:1:2.3) in the presence of a chaotropic salt (0.4 M LiCl in N-methyl-2-pyrrolidinone).Abbreviations BOP benzotriazolyloxy-tris-(dimethylamino)phosphonium hexafluorophosphate - DIEA diisopropylethylamine - Fmoc 9-fluorenylmethoxycarbony - HATU N-[(dimethylamino)1H-1,2,3-triazolo[4,5-b]pyridin-1-ylmethylene]-N-methylmethan-aminium hexafluorophosphate N-oxide - HOBt 1-hydroxybenzotriazole - HPLC high-performance liquid chromatography - MALDI-TOF matrix-assisted laser-desorption ionization time-of-flight mass spectrometry - NMM N-methylmorpholine - NMP N-methyl-2-pyrrolidinone - Pmc 2,2,5,7,8-pentamethyl-chroman-6-sulfonyl - ® solid support - TFA trifluoroacetic acid - TPTU 2-(2-pyridon-1-yl)-1,1,3,3-tetramethyluroniumfluoroborate. Abbreviations used for amino acids follow the recommendations of the IUPAC-IUB Commission of Biochemical Nomenclature [Eur. J. Biochem., 138 (1984) 9]     

The vegetable rennet of Cynara cardunculus L. contains two proteinases with chymosin and pepsin-like specificities

The flowers of cardoon (genus Cynara) are traditionally used in Portugal for cheese making. In this work the vegetable rennet of the species Cynara cardunculus L. was characterized in terms of enzymic composition and proteolytic specificity of its proteinases (cardosin A and cardosin B). Cardosin A was found to cleave insulin B chain at the bonds Leu15-Tyr16, Leu17-Val18 and Phe25-Tyr26. In addition to the bonds mentioned cardosin B cleaves also Glu13-Ala14, Ala14-Leu15 and Phe24-Phe25 indicating that it has a broader specificity. The kinetic parameters for the hydrolysis of the synthetic peptide Leu-Ser-Phe(NO₂)-Nle-Ala-Leu-oMe were also determined and compared to those of chymosin and pepsin. The results obtained indicate that in terms of specificity and kinetic parameters cardosin A is similar to chymosin whereas cardosin B is similar to pepsin. It appears therefore that the enzyme composition of cardoon rennet closely resembles that of calf rennet.     

Properties of a Large Complex with NADH Dehydrogenase Activity from Barley Thylakoids

When assays for NAD(P)H-ferricyanide oxidoreductases were performed,activities specific for NADH (0.23 unit (mg protein)^–1)and NADPH (0.68 unit (mg protein)^–1) were detected inchloroplasts isolated from leaves of barley (Hordeum vulgareL.). Activities of chloroplast NADH- and NADPH-ferricyanideoxidoreductase were 5-fold and 25-fold higher, respectively,than the maximum activity that could be attributed to mitochondrialcontamination. Moreover, most of the chloroplast NADH-ferricyanideoxidoreductase (60 to 80%) was solubilized by deoxycholate (DOC)from thylakoids as a single, high-molecular-mass complex thatwas distinguishable from the mitochondrial complex by its lowerelectrophoretic mobility in 3% polyacrylamide, as revealed byreduction of nitro blue tetrazolium (NBT) in the presence ofNADH or NADPH on gels after electrophoresis. The stroma yieldeda single band of a dehydrogenase (66 kDa) that used NADH asits electron donor. Several NADPH-dependent activities weredetected after electrophoresis of the stromal fraction. Moreover,chloroplast-specific activities could be distinguished frommitochondrial activities on the basis of the specificity ofthe donor and the acceptor of electrons, the dependence of theactivities on pH, and the sensitivity to various inhibitors.K_m values for NADH (26 µM) and NADPH (75 µM) werein the same range as those of mitochondrial activities. Mostof the NADPH-dependent activity probably corresponds to thechloroplast ferredoxin-NADP⁺ oxidoreductase. The possibilityis discussed that thylakoid NADH dehydrogenase(s) might be theproduct of chloroplast ndh genes and that this activity is involvedin chlororespiration. (Received April 25, 1994; Accepted December 5, 1994)     

Changes in the origin and quality of soil organic matter after pasture introduction in Rondônia (Brazil)

We examined the effects of the conversion of tropical forest to pasture on soil organic matter (SOM) origin and quality along a chronosequence of sites, including a primary forest and six pastures. Bulk soil samples received a physical size-fractionation treatment to assess the contribution of each compartment to total SOM pool. Besides a general increase in total C and N stocks along the chronosequence, we observed a reduction of the relative contribution of the coarser fractions to total soil C content, and an increased concentration in the finer fractions. The origin of the C in each size fraction was established from measurements of¹³C abundance. After 80 years about 93% of the C in the least humified fraction of the top 10 cm of soil was of pasture origin, while in the most humified it was 82%. Chemical analyses indicated that the fine silt and coarse clay fractions contained the most refractory carbon.     

Age structure,growth and reproduction ofRutilus lemmingii in an intermittent stream of the Guadalquivir river basin,southern Spain

The age, growth and reproduction ofRutilus lemmingii (Steindachner, 1866), an endemic cyprinid from the Iberian Peninsula, was studied for over a period of two years in a small seasonal tributary of the Guadalquivir river basin. Approximately 65 % of the total growth in length occured in the first year of life. Males reached a maximum age of 3+ yr (Fork Length, F.L. = 114 mm) and females 4+ yr (F.L. = 144 mm). Both sexes matured during their second year of life (1 +). The overall sex ratio (334 males to 389 females) differed significantly from unity. Somatic condition decreased markedly during the reproductive period of March to May.R. lemmingii is a multiple spawner and releases two batches of eggs per female each year. Mean egg diameter of the first batch was larger than the second one. The regression between fecundity and Fork Length (mm) was: Fec = 0.014 F.L.Z.^2.858 Compared with available information, thisR. lemmingii population, located at a lower latitude, is characterized by fast growth, early maturity, high level of reproductive effort, and a short life-span. These life-history characteristices are typical of species in unstable environments, where adult mortality is high, variable or unpredictable.     

Solution conformation and dynamics of a tetrasaccharide related to the LewisX antigen deduced by NMR relaxation measurements

¹H-NMR cross-relaxation rates and nonselectivelongitudinal relaxation times have been obtained at two magnetic fields (7.0and 11.8 T) and at a variety of temperatures for the branchedtetrasaccharide methyl3-O--N-acetyl-galactosaminyl--galactopyranosyl-(14)[3-O--fucosyl]-glucopyranoside (1), an inhibitor of astrocyte growth. Inaddition, ¹³C-NMR relaxation data have also been recorded atboth fields. The ¹H-NMR relaxation data have been interpretedusing different motional models to obtain proton–proton correlationtimes. The results indicate that the GalNAc and Fuc rings display moreextensive local motion than the two inner Glc and Gal moieties, since thosepresent significantly shorter local correlation times. The¹³C-NMR relaxation parameters have been interpreted in termsof the Lipari–Szabo model-free approach. Thus, order parameters andinternal motion correlation times have been deduced. As obtained for the¹H-NMR relaxation data, the two outer residues possess smallerorder parameters than the two inner rings. Internal correlation times are inthe order of 100 ps. The hydroxymethyl groups have also different behaviour,with the exocyclic carbon on the glucopyranoside unit showing the highestS². Molecular dynamics simulations using a solvated systemhave also been performed and internal motion correlation functions have beendeduced from these calculations. Order parameters and interproton distanceshave been compared to those inferred from the NMR measurements. The obtainedresults are in fair agreement with the experimental data.