Chlorophyll distribution pattern in inner stem tissues: evidence from epifluorescence microscopy and reflectance measurements in 20 woody species

The occurrence of functional chloroplasts in internal stem tissues and their distribution profiles in 20 woody species have been investigated. Chloroplasts were identified from the red chlorophyll auto-fluorescence using epi-fluorescence microscopy. Chloroplasts were detected in the cortex of all species examined, in the xylem rays of 19 and in the perimedullar and the pith cells of 16 out of the 20 investigated species. Chloroplast containing cell clusters in the pith were identified in some species. In addition, we report on the semi-quantitative distribution of chlorophylls in various internal stem tissues. Chlorophyll level was estimated by reflectance measurements at specific wave bands. Although decreasing chlorophyll gradients from cortex to pith were observed in half of the species, chlorophyll distribution in the remaining species was irregular with occasionally high levels in the pith. According to our data, chlorophyll occurrence in stem internal tissues is quite widespread, even in the light remote, deeply shaded central compartments like pith, provided that corresponding cells are viable. The species-specific tissue distribution of chlorophyll levels may be used to select suitable plants to investigate further this neglected area of photosynthesis research.     

A specific short dextrin-hydrolyzing extracellular glucosidase from the thermophilic fungus Thermoascus aurantiacus 179-5

The thermophilic fungus Thermoascus aurantiacus 179-5 produced large quantities of a glucosidase which preferentially hydrolyzed maltose over starch. Enzyme production was high in submerged fermentation, with a maximal activity of 30 U/ml after 336 h of fermentation. In solid-state fermentation, the activity of the enzyme was 22 U/ml at 144 h in medium containing wheat bran and 5.8 U/ml at 48 h when cassava pulp was used as the culture medium. The enzyme was specific for maltose, very slowly hydrolyzed starch, dextrins (2-7G) and the synthetic substrate (alpha-PNPG), and did not hydrolyze sucrose. These properties suggest that the enzyme is a type II alpha-glucosidase. The optimum temperature of the enzyme was 70 degrees . In addition, the enzyme was highly thermostable (100% stability for 10 h at 60 degrees and a half-life of 15 min at 80 degrees), and stable within a wide pH range.     

Neutral and cationic mononuclear copper(II) complexes with enrofloxacin: structure and biological activity

The mononuclear copper complexes with the quinolone antibacterial drug enrofloxacin (=Herx) in the presence or not of a nitrogen donor heterocyclic ligand 1,10-phenanthroline (=phen) and 2,2'-bipyridine (=bipy) have been prepared and characterized. Interaction of copper(II) with deprotonated enrofloxacin leads to the formation of the neutral complex Cu(erx)2(H2O), 1, while the presence of phen or bipy leads to the formation of a neutral or a cationic mononuclear complex, respectively. The crystal structures of (chloro)(1,10-phenanthroline)(enrofloxacinato)copper(II), 2, and (aqua)(2,2'-bipyridine)(enrofloxacinato)copper(II) chloride, 3, have been determined with X-ray crystallography. The complexes have been studied with X-band electron paramagnetic resonance in aqueous solutions at liquid helium temperature. The study of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques and has showed that all complexes are bound to DNA by the intercalative mode. The antimicrobial efficiency of the complexes has been tested on three different microorganisms and the available evidence supports that the best inhibition is provided by Cu(erx)2(H2O) (minimum inhibitory concentration=0.125 microg mL(-1)) against Escherichia coli and Pseudomonas aeruginosa.     

Synthesis, structure and biological activity of copper(II) complexes with oxolinic acid

The neutral mononuclear copper complexes with the quinolone antibacterial drug oxolinic acid in the presence or not of a nitrogen donor heterocyclic ligand 1,10-phenanthroline, 2,2'-bipyridine or 2,2'-dipyridylamine have been synthesized and characterized with infrared, UV-visible and electron paramagnetic resonance spectroscopies. The experimental data suggest that oxolinic acid acts as a deprotonated bidentate ligand and is coordinated to the metal ion through the pyridone and one carboxylate oxygen atoms. The crystal structure of (chloro)(1,10-phenanthroline)(oxolinato) copper(II), 2, has been determined with X-ray crystallography. For all complexes a distorted square pyramidal environment around Cu(II) is suggested. The EPR (electron paramagnetic resonance) behavior of 2 in aqueous solutions indicates mixture of dimeric and monomeric species. The investigation of the interaction of the complexes with calf-thymus DNA has been performed with diverse spectroscopic techniques and showed that the complexes are bound to calf-thymus DNA. The antimicrobial activity of the complexes has been tested on three different microorganisms. The complexes show a decreased biological activity in comparison to the free oxolinic acid.     

Rosmarinic acid failed to suppress hydrogen peroxide-mediated apoptosis but induced apoptosis of Jurkat cells which was suppressed by Bcl-2

Rosmarinic acid (RosA), frequently found as a secondary metabolite in herbs and medicinal plants, has exhibited antioxidative and anti-inflammatory activities. RosA was shown to inhibit the proliferation and induce apoptosis of Jurkat T cells but the mechanism of action of RosA in apoptosis remains elusive. RosA inhibited the proliferation of Jurkat cells in a dose-dependent manner by suppressing the expression of cyclin D₃ and p21^Cip1/Waf1 and up-regulating p27^Kip1. RosA induced apoptosis of Jurkat cells in a dose-dependent manner and failed to protect them from hydrogen peroxide (H₂O₂)-mediated apoptosis. Induction of apoptosis by RosA correlated with suppression of Bcl-2 but not of Bak or PUMA. Overexpression of Bcl-2 protected Jurkat cells from both H₂O₂- and RosA-induced apoptosis by altering the ratio of anti- to pro-apoptotic members of the Bcl-2 family. In conclusion, RosA inhibited Jurkat cell proliferation by altering the expression of cyclins and cyclin-dependent kinase inhibitors and induced apoptosis most likely acting through the mitochondrial pathway and possessed no anti-oxidant properties.     

Multiple biological activities for two peptides derived from the nerve growth factor precursor

ProNGF can be cleaved proteolytically at dibasic residues and liberates two other peptides beside NGF, LIP1 a 29 amino acid (aa) peptide and LIP2 a 38 aa peptide. These peptides were found present in the rat intestine and shown to induce rapid phosphorylation of the Trk receptor in cell lines. The present study describes several novel biological properties for these peptides. They exert an anti-proliferative effect on the mitogenic activity of estrogen and IGF in MCF-7 cells. They protect against in vivo induction of excitotoxic lesions by the glutamatergic analogue ibotenate injected into the developing mouse brain and against in vitro NMDA-induced cell death in primary neuronal cultures. They bind to murine microglial cells and induce phosphorylation of Akt. These results suggest a role for LIP1 and LIP2 in cell survival.     

Elevated serum triglycerides is the strongest single indicator for the presence of metabolic syndrome in patients with type 2 diabetes

Objectives

South-Asians have lower adiponectin levels compared to Caucasians. It was not clear however, if this intrinsic feature is related to aspects of glucose metabolism. This study aims to determine the relationship between body fat distribution and adipocytokine in South-Asian subjects by measuring serum adipocytokines, adiposity, insulinemia, and glucose tolerance levels.

Methods

In this cross-sectional study, 150 South-Asians (80 males, 70 females) were included, 60 had NGT (Control group, Age 51.33 ± 11.5, BMI 27 ± 2.3), 60 had IGT (Age 57.7 ± 12.5, BMI 27.2 ± 2.7), 30 had type 2 DM (Age 49.5 ± 10.9, BMI 28 ± 1.7). Measures of adiposity, adipocytokines and other metabolic parameters were determined. Parameters were measured using the following: a) Plasma glucose by glucose oxidase method b) CRP by immunoturbidimetric method (Roche/Hitachi analyser) c) insulin by Medgenix INS-ELISA immunoenzymetric assay by Biosource (Belgium) d) Leptin, Adiponectin by radioimmunoassay kits by Linco Research (St. Charles MO) e) Resistin by immunoassay kits by Phoenix Pharmaceuticals INC (530 Harbor Boulevard, Belmont CA 94002, USA).

Results

Adiponectin concentrations were highest in NGT, decreased in IGT and lowest in DMT2, (both p < 0.01). Leptin was significantly higher in DMT2 than IGT and NGT p = 0.02 and 0.04 respectively. There was a significant positive relationships between log adiponectin and 2-hr insulin values, p = 0.028 and history of hypertensions and a ischemic heart disease p = 0.008 with R = 0.65. There was a significant inverse correlation between log adiponectin and resistin, p < 0.01.

Conclusion

Resistin levels had an inverse correlation with adiponectin levels, indicating an inverse relationship between pro-inflammatory cytokines and adiponectin. Adiponectin levels were related to glucose tolerance.