Targeted worm micelles

Giant and stable worm micelles formed from poly(ethylene glycol) (PEG)-based diblock copolymer amphiphiles have the potential advantage compared to smaller assemblies for delivery of a large quantity of hydrophobic drugs or dyes per carrier. Here we show that worm micelles can be targeted to cells with internalization and delivery of nontoxic dyes as well as cytotoxic drugs. Constituent copolymers are end-biotinylated to mediate high affinity binding of worm micelles to both avidin-bearing surfaces and biotin-specific receptors on smooth muscle cells. Pristine worm micelles, that lack biotin, show much less frequent and nonspecific point attachments to the same surfaces. Biotinylated worm micelles prove stable in aqueous solution for at least a month and also prove capable of loading, retaining, and delivering hydrophobic dyes and drugs. The results thus demonstrate the feasibility of targeted delivery by polymeric worm micelles.     

Passive immunization of rams (Ovis aries) against GnRH: effects on antibody titer,serum concentrations of testosterone,and sexual behavior

The effect of immunoneutralization of gonadotropin-releasing hormone (GnRH) on serum concentrations of testosterone and sexual behavior was evaluated in sexually mature male sheep. In Experiment 1, GnRH1 rams (n=16) were passively immunized against GnRH (300 ml antiserum), control rams were either passively immunized against keyhole limpet hemocyanin (KLH, n=15) or surgically castrated (Wethers1, n=4). Sexual performance of the rams was assessed weekly for 3 weeks before and 6 weeks after immunization, using ovarihystertomized ewes actively immunized against GnRH. Experiment 2 evaluated the effects of repeated immunization. Rams were immunized with two aliquots (400 and 300 ml, respectively) of anti-GnRH sera (GnRH, n=5) or normal sheep serum (NSS, n=4), 2 weeks apart. Surgically castrated animals were used as a second control group (Wethers2). Administration of anti-GnRH sera, but neither anti-KLH nor NSS sera, resulted in marked reduction (P<0.05) in serum concentrations of testosterone. Sexual behavior was not consistently affected by administration of one aliquot of anti-GnRH sera, however repeated immunizations resulted in more persistent reduction in serum concentrations of testosterone and more consistent suppression of sexual behavior.     

Dietary oxidized fatty acids may enhance intestinal apolipoprotein A-I production

Apolipoprotein (apo)A-I, the major protein component of HDL, is synthesized principally in the small intestine and liver. Recently we observed an increase in plasma apoA-I level in humans who were on an oxidized fat diet. To test whether oxidized fatty acids could affect apoA-I synthesis, we incubated day 4 (undifferentiated) and day 14 (differentiated) Caco-2 cells with varying concentrations of oxidized linoleic acid (ox-linoleic acid) (5, 10, and 25 microM) and unoxidized linoleic acid for 24 h. Ox-linoleic acid caused a dose-dependent increase in the levels of apoA-I protein in both differentiated and undifferentiated Caco-2 cells as assessed by ELISA and Western blot analysis. Whereas apoB production was not increased by ox-linoleic acid in both day 4 and day 14 Caco-2 cells. The mRNA expression for apoA-I paralleled the protein expression when measured by RT-PCR. We also found that both day 4 and day 14 Caco-2 cells did express peroxisomal proliferator-activated receptor-gamma (PPAR-gamma). mRNA and PPAR-gamma ligand could increase apoA-I secretion in these cells.Therefore we propose that the mechanism for the induction of apoA-I might include PPAR-gamma for which oxidized fatty acid is a ligand.     

Erythrocyte,lipid peroxidation and antioxidant enzymes in hypervitaminotic A rats and their modification by dietary protein

Rats fed excess vitamin A showed decreased body weight gain and protein efficiency ratio. In rats fed low protein vitamin A level increased in liver but with an associated decrease in plasma. These changes were reversed in high protein fed state. The amount of protein in diet had little effect on haemoglobin level in erythrocyte, but excess vitamin A in diet significantly decreased haemoglobin level in erythrocyte. Lipid peroxidation (LP) increased in rats fed low protein and decreased in high protein fed rats. Rats fed high protein and excess vitamin A showed minimum level of LP. Result showed that high protein in diet increased the levels of antioxidant enzymes, catalase and superoxide dismutase (SOD) and that excess vitamin A supplementation functions synergistically with high protein in diet to increase antioxidant enzymes level.     

Plant regeneration from embryo-derived callus of oil palm – the effect of exogenous polyamines

Regeneration in oil palm was achieved through somatic embryogenesis/organogenesis from embryo-derived callus. Callus was induced from mature embryos of the cross 281 (D)×18 (P) on modified MS medium supplemented with 2,4-D (113.12 M) and 2-iP (14.76 M). The embryogenic calluses obtained were transferred to Blaydes medium supplemented with 2,4-D (0.045 M) and one of the following growth regulators: TDZ (4.54 M), zeatin riboside (2.85 M), putrescine (1 mM) and spermine (100 M). Secondary somatic embryogenesis was found to occur in media supplemented with polyamines. The efficiency of formation of somatic embryos, secondary somatic embryos and shoot meristemoids were significantly higher in putrescine containing medium. Histological studies were also undertaken.     

Lipid peroxides induce expression of catalase in cultured vascular cells

Various forms of oxidized low-density lipoproteins (Ox-LDL) are thought to play a major role in the development of atherosclerosis. The lipid components of Ox-LDL present a plethora of proatherogenic effects in in vitro cell culture systems, suggesting that oxidative stress could be an important risk factor for coronary artery disease. However, buried among these effects are those that could be interpreted as antiatherogenic. The present study demonstrates that various oxidants, including oxidized fatty acids and mildly oxidized forms of LDL (MO-LDL), are able to induce catalase (an antioxidant enzyme) expression in rabbit femoral arterial smooth muscle cells (RFASMC), RAW cells (macrophages), and human umbilical vein endothelial cells (HUVEC). In RFASMC, catalase protein, mRNA, and the enzyme activity are increased in response to oxidized linoleic acid (13-hydroperoxy-9,11-octadecadienoic acid [13-HPODE] and 13-hydroxy-9,11-octadecadienoic acid [13-HODE]), MO-LDL, or hydrogen peroxide (H(2)O(2)). Such an increase in catalase gene expression cannot totally be attributed to the cellular response to an intracellular generation of H(2)O(2) after the addition of 13-HPODE or 13-HODE because these agents induce a further increase of catalase as seen in catalase-transfected RFASMC. Taken together with the induction of heme oxygenase, NO synthase, manganese superoxide dismutase (Mn-SOD), and glutathione synthesis by oxidative stress, our results provide yet more evidence suggesting that a moderate oxidative stress can induce cellular antioxidant response in vascular cells, and thereby could be beneficial for preventing further oxidative stress.     

Pseudomonas aeruginosa RRALC3 Enhances the Biomass,Nutrient and Carbon Contents of Pongamia pinnata Seedlings in Degraded Forest Soil

The study was aimed at assessing the effects of indigenous Plant Growth Promoting Bacterium (PGPB) on the legume Pongamia pinnata in the degraded soil of the Nanmangalam Reserve Forest (NRF) under nursery conditions. In total, 160 diazotrophs were isolated from three different nitrogen-free semi-solid media (LGI, Nfb, and JMV). Amongst these isolates, Pseudomonas aeruginosa RRALC3 exhibited the maximum ammonia production and hence was selected for further studies. RRALC3 was found to possess multiple plant growth promoting traits such as nitrogen accumulation (120.6ppm); it yielded a positive amplicon with nifH specific primers, tested positive for Indole Acetic Acid (IAA; 18.3μg/ml) and siderophore production, tested negative for HCN production and was observed to promote solubilization of phosphate, silicate and zinc in the plate assay. The 16S rDNA sequence of RRALC3 exhibited 99% sequence similarity to Pseudomonas aeruginosa JCM5962. Absence of virulence genes and non-hemolytic activity indicated that RRALC3 is unlikely to be a human pathogen. When the effects of RRALC3 on promotion of plant growth was tested in Pongamia pinnata, it was observed that in Pongamia seedlings treated with a combination of RRALC3 and chemical fertilizer, the dry matter increased by 30.75%. Nitrogen, phosphorus and potassium uptake increased by 34.1%, 27.08%, and 31.84%, respectively, when compared to control. Significant enhancement of total sugar, amino acids and organic acids content, by 23.4%, 29.39%, and 26.53% respectively, was seen in the root exudates of P. pinnata. The carbon content appreciated by 4-fold, when fertilized seedlings were treated with RRALC3. From the logistic equation, the rapid C accumulation time of Pongamia was computed as 43 days longer than the control when a combination of native PGPB and inorganic fertilizer was applied. The rapid accumulation time of N, P and K in Pongamia when treated with the same combination as above was 15, 40 and 33 days longer, respectively, as compared to the control.