Rat liver carbohydrate alterations in streptozotocin-induced diabetic rats

Diabetes mellitus (DM) currently belongs to the most widespread human pathologies, affecting about 4% of the world adult population. Despite the pivotal role of the liver in the development of metabolic disorders, the influence of DM on hepatic glycoconjugates remains obscure. The aim of the present investigation was to use a set of lectins with different carbohydrate affinities to investigate impairment in rat liver glycoconjugates influenced by streptozotocin-induced diabetes mellitus. The lectin panel included 7 conventional lectins - Con A, SNA, RCA, WGA, PNA, SBA, and HPA, supplemented with the original fucose-specific lectin preparation from Laburnum anagyroides bark (LABA). Tissue samples were fixed in 4% neutral formalin, embedded in paraffin, and subjected to lectin-peroxidase-diaminobenzidine staining. In control rats a strong reactivity against Con A, LABA, SBA and SNA with cytoplasmic granularities of hepatocytes was detected, while RCA, WGA and HPA showed a strong reactivity with vascular endothelium, and WGA and HPA with bile capillaries. Experimental diabetes was associated with a redistribution of Con A and LABA receptor sites from centrolobular hepatocytes to hepatocytes with peripheral localization. Among the most remarkable observations was DMinduced exposure of lectin reactivity with hepatocyte and endothelial cell nuclei. The endothelial lining of sinusoidal hemocapillaries, of central veins, and portal tract vessels also displayed a significant and differential rearrangement of carbohydrate determinants when influenced by DM. Diabetes-induced activation of Kupffer cells was accompanied by the expression of SNA, PNA and SBA receptor sites within the cytoplasm of these cells, which was lectin-negative in control specimens. The results reported provide a new insight into the pathogenesis of DM-induced impairment of hepatic carbohydrates, and demonstrate the applicability of the original fucose-specific lectin preparation to experimental histopathology (AU)

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DNA damage in plant herbarium tissue.

Dried plant herbarium specimens are potentially a valuable source of DNA. Efforts to obtain genetic information from this source are often hindered by an inability to obtain amplifiable DNA as herbarium DNA is typically highly degraded. DNA post-mortem damage may not only reduce the number of amplifiable template molecules, but may also lead to the generation of erroneous sequence information. A qualitative and quantitative assessment of DNA post-mortem damage is essential to determine the accuracy of molecular data from herbarium specimens. In this study we present an assessment of DNA damage as miscoding lesions in herbarium specimens using 454-sequencing of amplicons derived from plastid, mitochondrial, and nuclear DNA. In addition, we assess DNA degradation as a result of strand breaks and other types of polymerase non-bypassable damage by quantitative real-time PCR. Comparing four pairs of fresh and herbarium specimens of the same individuals we quantitatively assess post-mortem DNA damage, directly after specimen preparation, as well as after long-term herbarium storage. After specimen preparation we estimate the proportion of gene copy numbers of plastid, mitochondrial, and nuclear DNA to be 2.4-3.8% of fresh control DNA and 1.0-1.3% after long-term herbarium storage, indicating that nearly all DNA damage occurs on specimen preparation. In addition, there is no evidence of preferential degradation of organelle versus nuclear genomes. Increased levels of C→T/G→A transitions were observed in old herbarium plastid DNA, representing 21.8% of observed miscoding lesions. We interpret this type of post-mortem DNA damage-derived modification to have arisen from the hydrolytic deamination of cytosine during long-term herbarium storage. Our results suggest that reliable sequence data can be obtained from herbarium specimens.

Cytisine's potential to be used as a traditional healing method to help indigenous people stop smoking: a qualitative study with Maori.

INTRODUCTION: Maori experience a disproportionate amount of smoking-related harm (46% of adult Maori smoke). Effective cessation treatments that are both accessible and attractive to Maori are urgently needed. Cytisine (a plant extract found in Golden Rain [Cytisus laburnum L.] and the New Zealand Kowhai [Sophora tetraptera L.] has a similar molecular makeup to nicotine, has been used successfully as a cessation product in central and eastern Europe and central Asia for many years, and is low priced. Recent reviews have found that cytisine is twice as effective as a placebo for smoking cessation. This study aimed to explore cytisine's potential as a 'rongoa Maori' (traditional Maori remedy) and its attractiveness to Maori smokers compared with other cessation products. METHODS: Maori that smoked were interviewed in two focus groups and eight individual semi-structured interviews. Two key informants were interviewed also. RESULTS: Barriers to using cessation products were financial and effort cost, pervasive smoking among family and peers, environments permissive of smoking, and perceived cultural inappropriateness of treatments. Participants were very interested in cytisine, supported the idea that it would be acceptable to package it as a rongoa Maori, and all wanted to use it. Named appropriately, packaged and promoted as a Maori cessation product, participants thought cytisine would contribute to the restoration of Maori identity and traditional beliefs and practices in addition to reducing smoking. CONCLUSIONS: Presented as a rongoa Maori, cytisine would likely be more attractive to Maori than currently available cessation products. Confirmation of efficacy and safety will be needed before promotion of the product could occur.

Fatal cytisine intoxication and analysis of biological samples with LC-MS/MS.

We report about a fatal cytisine intoxication in a 20-year-old man who, according to his mother, had drunken tea prepared from plant material of Laburnum anagyroides with the toxic pyridine-like alkaloid as ingredient, which exhibits pharmacological effects similar to nicotine. Using a liquid chromatographic-mass spectrometric (LC-MS) procedure cytisine was quantified in post-mortem specimens. By exclusion of other causes of death an intoxication was determined as the cause of death with respiratory failure as the pathophysiological mechanism.

Cytisine-based nicotinic partial agonists as novel antidepressant compounds.

Nicotine and other nicotinic agents are thought to regulate mood in human subjects and have antidepressant-like properties in animal models. Recent studies have demonstrated that blockade of nicotinic acetylcholine receptors (nAChRs) including those containing the beta2 subunit (beta2(*)), results in antidepressant-like effects. Previous studies have shown that cytisine, a partial agonist at alpha4/beta2(*) nAChRs, and a full agonist at alpha3/beta4(*) and alpha7 nAChRs, has antidepressant-like properties in several rodent models of antidepressant efficacy; however, it is not clear whether more selective partial agonists will also be effective in these models. We tested cytisine and two derivatives, 5-bromo-cytisine (5-Br-Cyt) and 3-(pyridin-3'-yl)-cytisine (3-pyr-Cyt) for their ability to act as a partial agonist of different nAChR subtypes and to show antidepressant-like activity in C57/BL6 mice in the tail suspension, the forced-swim, and the novelty-suppressed feeding tests. 3-pyr-Cyt was a partial agonist with very low efficacy at alpha4/beta2(*) nAChRS but had no agonist effects at other nAChRs normally targeted by cytisine, and it was effective in mouse models of antidepressant efficacy. Animals showed dose-dependent antidepressant-like effects in all three behavioral paradigms. 5-Br-Cyt was not effective in behavioral tests when administered peripherally, probably because of its inability to penetrate the blood-brain barrier, because it efficiently reduced immobility in the tail suspension test when administered intraventricularly. These results suggest that novel nicotinic partial agonists may provide new possibilities for development of drugs to treat mood disorders.

Antibacterial and antioxidant properties of the methanol extracts of the leaves and stems of Calpurnia aurea.

BACKGROUND: In South Africa, Calpurnia aurea (Ait.) Benth is used to destroy lice and to relieve itches, to destroy maggots and to treat allergic rashes, particularly those caused by caterpillars. Antioxidants play an important role protecting against damage by reactive oxygen species. Plants containing flavonoids have been reported to possess strong antioxidant properties. METHODS: The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of Calpurnia aurea were evaluated using in vitro standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the stem extract of Calpurnia aurea were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant. RESULTS: The results from this study showed that the antioxidant activities of the stem extract of Calpurnia aurea as determined by the total phenol, flavonoids, and FRAP methods were higher than that of the leaves. On the other hand, the leaf extract of the plant has higher level of total flavonols and proanthocyanidins. The leaf extract also has higher radical scavenging activity as shown in 1, 1-Diphenyl-2-picrylhydrazyl (DPPH), and 2,2¿-azinobis-3- ethylbenzothiazoline-6-sulfonic acid (ABTS) assay. The leaf extract showed activity against seven of the bacterial organisms. CONCLUSION: The results from this study indicate that the leaves and stem extracts of Calpurnia aurea possess antioxidant properties and could serve as free radical inhibitors or scavenger or, acting possibly as primary antioxidants. Although, the antibacterial properties of Calpurnia aurea are not as effective as the standard drugs- Chloramphenicol and Streptomycin, they still possess some activity against bacterial strains used in this study. Calpurnia aurea may therefore be a good candidate for functional foods as well as pharmaceutical plant-based products.

[Structure of carbohydrate chains of fucolectin from the bark of golden rain shrub Laburnum anagyroides].

A reductive LiBH4-ButOH cleavage of N-glycosylamide carbohydrate-peptide bond allowed splitting off of oligosaccharide chains of the fucolectin, the bark agglutinin from the shrub golden rain Laburnum anagyroides (LABA). Four N-glycans were isolated by HPLC, and their structures were elucidated by monosaccharide analysis and 1H NMR (500 MHz) spectroscopy: Man2Fuc1XyllGlcNAc2 (M2FX), Man3XyllGlcNAc2 (M3X), Man3FuclXyllGlcNAc2 (M3FX), and Man3XyllFucIGlcNAc3 (NM3FX). All the N-glycans contain D-xylose and three of them, L-fucose; they were found to be in a 1 : 8 : 1 : 3 ratio.

[Interaction of the Laburnum anagyroides lectin with fucoantigens].

We studied interaction of the lectin from the bark of Golden Rain shrub (Laburnum anagyroides, LABA) with a number of basic fucose-containing carbohydrate antigens by changes in its tryptophan fluorescence. The strongest LABA binding was observed for the trisaccharide H of type 6 [alpha-L-Fucp-(1-2)-beta-D-Galp-(1-4)-D-Glc, Ka= 4.2 x 10(3) M(-1)]. The following antigens were bound with a weaker affinity: H-disaccharide alpha-L-Fucp-(1-2)-D-Gal, a glucoanalogue of tetrasaccharide Ley alpha-L-Fucp-(1-2)-beta-D-Galp-(1-4)-[alpha-L-Fucp-(1-3)]-D-Glc, and 6-fucosyl-N-acetylglucosamine, a fragment of core of the N-glycans family (Ka 1.1-1.7 x 10(3) M(-1)). The lowest binding was observed for L-fucose (Ka = 2.7 x 10(2) M-1) and trisaccharide Lea, (3-Galp-(1-3)-[a-L-Fucp-(1-4)]-GlcNAc (Ka = 6.4 x 10(2) M(-1)). The Lea, Lea, and Lex pentasaccharides and Leb hexasaccharide were not bound to LABA.

[Oligosaccharide specificity of the fucolectin from the bark of laburnum Laburnum anagyroides]. / Oligosakharidnaia spetsifichnost' fukolektina kory bobovnika Laburnum anagyroides.

A comparative study of thin carbohydrate specificity of the lectin from the bark of laburnum Laburnum anagyroides (LABA) and fucolectin from asparagus pea Tetragonolobus purpureus (TPA) was performed using inhibition of agglutination of the complex formed by H-active neoglycoprotein and nanoparticles of colloidal gold. Both lectins bound most strongly the H type 2 oligosaccharides comprising O-glycanes; however, TPA was almost unable to discriminate between them. LABA bound more weakly the H type 6 trisaccharide (Fuc alpha 1-2Gal beta 1-4Glc) and difucosyllactose (Fuc alpha 1-2Gal beta 1-4[Fuc alpha 1-3]Glc), a glucoanalogue of the Le(y) antigen, and, even more weakly, the Le(a) pentasaccharide lacto-N-fucopentaose II (Gal beta 1-3[Fuc alpha 1-4]GlcNAc beta 1-3Gal beta 1-4Glc). However, LABA did not bind the antigens Le(b), Le(c), and Le(d), very poorly interacted with the terminal Le(x), and somewhat more strongly bound the internal Le(x). The lectin also had a hydrophobic binding site. Both lectins exhibited a cluster effect with polymeric ligands (neoglycoproteins).

[Populations of afferent neurons in the sensory ganglia detected using lectin from Laburnum anagyroides]. / Populiatsii afferentnykh neironov v chuvstvitel'nykh uzlakh, vyiavlennye s ispol'zovaniem lektina bobovnika anagirolistnogo.

The purpose of the present research was the study of afferent neuron subpopulations in vagal caudal ganglia and trigeminal ganglion of adult albino rats using a conjugate of fucose-specific Laburnum anagyroides lectin (LAL) with peroxidase. Histochemical preparations obtained were examined using computer videoanalyzer with the determination of dimensions of afferent neurons and integral optical density (IOD) of their cytoplasm. In the ganglia studied LAL was found to bind to the majority (more than 98%) of neurons. Reaction product was demonstrated in the perikaryon either as discrete granules (Nissl body-type), or as a uniform precipitate. Nucleoplasm in most of neurons remained lightly stained. Determination of IOD of neuronal cytoplasm in various ganglia demonstrated significant differences in degree of LAL accumulation. Analysis of interrelation between neuronal size and IOD permitted to establish non-linear correlation of metric and optical parameters and to detect subpopulations of cells in the sensory ganglia, which were stained with LAL most intensely. Functional specialization of these cells remains to be determined. Thus, a combined application of lectin-histochemical method with a computer videoanalysis of morphological slides enabled the identification neuronal populations and subpopulations in rat afferent ganglia, which are not demonstrated with the standard histological methods.

Siembra directa de nueve especies nativas y exóticas (arboreas y arbustivas) en el Parque Nacional Tunari

El estudio tuvo por finalidad determinar las especies nativas y exóticas de 9 especies, aptas para la siembra directa en las diferentes condiciones edafoclimáticas del Parque Nacional Tunari (10 pisos ecológicos), conocer los tratamientos pregerminativos más favorables (sin o con tratamiento); el método de siembra adecuado para las especies (remoción de tierra a 5 y 20 cm. de profundidad) y determionar los factores edafoclimáticos en siembras de dos tipos de ensayo (Tipo I y II); conducido en diseño completamente al azar con tres repeticiones. Los resultados en los ensayos Tipo I, determinaron que los tratamientos pregerminativos y la remoción del suelo fueron estadísticamente similares en la germinación y la sobrevivencia. En los ensayos Tipo II, de los 10 pisos establecidos, las especies Tipuana Tipa y Acacia caven, reportaron las emergencias en los pisos 1 y 2; mientras que en los pisos 3, 4, 5 y 6, Caesalpina tintorea fue la mejor entre las especies nativas. entre las exóticas, Pinus radiata y eucaliptus globulus de los pisos 7, 8 y 9 respectivamente.