Improved isolation of glucuronan from algae and the production of glucuronic acid oligosaccharides using a glucuronan lyase

A new source for the production of bioactive glucuronic acid oligosaccharides (GlcUAOs) from the depolymerization of green seaweed Ulva lactuca glucuronan (Algal glucuronan) has been investigated. Algal glucuronan purification was optimized by the acidic precipitation method which allowed us to separate the polysaccharide mixture extracted from the cell wall of Ulva lactuca using hot water containing sodium oxalate. A series of the GlcUAOs were obtained by enzyme degradation of algal glucuronan with a glucuronan lyase (GL) isolated from Trichoderma strain. The putative bioactive GlcUAOs generated were then purified by size-exclusion chromatography in gram quantity and characterized by ¹H/¹³C NMR spectroscopy and ESI-Q/TOF-mass spectrometry.     

Regioselectivity in the glycosylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thiol

The glycosylation of 5-(3-chlorobenzo[b]thien-2-yl)-4H-1,2,4-triazole-3-thiol (1) and its 3-benzylsulfanyl and 3-methylsulfanyl derivatives with different glycosyl halides 2-4 has been studied in presence of base. The S-glycosides 5-7 were obtained in the presence of triethylamine, whereas the respective S,N⁴-bis(glycosyl) derivatives 8-10 were synthesized in the presence of potassium carbonate; the S,N²-bis(glycosyl) isomer 11 could also be isolated in the case of the galactosyl analog. Similarly, after protecting 1 as 3-benzyl(methyl)sulfanyl derivatives 12 or 13, the N⁴-glycosyl analogs 14-19 as well as minor amounts of S,N²-bis(galactosyl) isomers 20 and 21 were formed. The theoretical calculations using AM1 semiempirical methods agreed with the experimental results. Microwave irradiation (MWI) led to higher yields in much less time than the conventional methods, and no change in regioselectivity has been noticed.     

Pdk1 activity controls proliferation, survival, and growth of developing pancreatic cells

The formation of adequate masses of endocrine and exocrine pancreatic tissues during embryogenesis is essential to ensure proper nutrition and glucose homeostasis at postnatal stages. We generated mice with pancreas-specific ablation of the 3-phosphoinositide-dependent protein kinase 1 (Pdk1) to investigate how signaling downstream of the phosphatidylinositol-3-OH kinase (PI3K) pathway controls pancreas development. Pdk1-conditional knock-out mice were born with conspicuous pancreas hypoplasia, and within a few weeks, they developed severe hyperglycemia. Our detailed characterization of the mutant embryonic pancreas also revealed distinct temporal, cell type-specific requirements of Pdk1 activity in the control of cell proliferation, cell survival, and cell size during pancreas development. These results thus uncover Pdk1 as a novel, crucial regulator of pancreatic growth during embryogenesis. In addition, we provide evidence that Pdk1 activity is required differently in mature pancreatic cell types, since compensatory proliferation and possible mTORC2 activation occurred in exocrine cells but not in β cells of the Pdk1-deficient postnatal pancreas.     

Cyclin D1 gene amplification in proliferating haemangioma

Cyclin D1 gene amplification has been reported to promote abnormal endothelial cell proliferation and angiogenesis; these findings constantly present in proliferating haemangiomas. The present study was conducted to evaluate cyclin D1 gene amplification by fluorescence in situ hybridization analysis in tissue biopsies of 22 proliferating haemangiomas from 20 infants. Two significant correlations of cyclin D1 gene amplification with the early onset and the duplication of proliferating haemangiomas have been observed. Moreover, a significant correlation (P≤0.05) has been found between the treatment parameters of proliferating haemangiomas with the amplified versus the normal cyclin D1 gene. Proliferating haemangiomas with the amplified cyclin D1 gene required more frequent flashlamp pulsed dye laser treatment sessions at the maximum dosimetry and more frequent intralesional steroid injections at the maximum dose/injection but treatment outcomes were limited. The more frequent post-treatment complications among proliferating haemangiomas with cyclin D1 gene amplification might be attributable not only to the associated more aggressive natural course, but also to the higher treatment parameters needed for effective treatment. Within the limitations of the present study, cyclin D1 gene amplification was seen for the first time in proliferating haemangiomas. We have found that the amplification of the cyclin D1 gene can predict the more aggressive natural course of proliferating haemangiomas and the limited outcome and higher incidence of complications after non–excision treatment modalities. The present findings reflect the possible usefulness of antisense cyclin D1 to improve the therapeutic outcome of proliferating haemangiomas.     

Towards understanding the mode of action of the multifaceted cell adhesion receptor CD146

CD146, also known as melanoma cell adhesion molecule or MCAM, is a key cell adhesion protein in vascular endothelial cell activity and angiogenesis. CD146 promotes tumor progression of many cancers including melanoma and prostate. Strikingly, its expression is frequently lost in breast carcinoma cells, and it may act as a suppressor of breast cancer progression. While upstream mechanisms regulating CD146 are well documented, our understanding of the downstream molecular events underlying its mode of action remains to be elucidated. This review aims to focus on the progress in understanding the signaling mechanisms and the functional relevance of CD146, a multifaceted molecule, in cancer with particular emphasis on its role in inhibiting breast cancer progression.     

Effect of physical desiccation on plant regeneration efficiency in rice (Oryza sativa L.) variety super basmati

This experiment assessed the effect of partial physical desiccation on plant regeneration efficiency in scutellum-derived embryogenic calluses of rice (Oryza sativa L.) variety Super basmati. A number of callusing cultures were developed, and efficient callus induction was observed on MS (Murashige and Skoog) basal medium supplemented with 2.0 mg/L 2,4-dichlorophenoxy acetic acid. The calluses were proliferated on the same medium for 3 weeks and then shifted to dehydration desiccation treatment for 72 h. The desiccated calluses were cultured on different media for somatic embryogenesis and plant regeneration. A medium with 2.0 mg/L α-napthaleneacetic acid, 10.0 mg/L abscisic acid , 2.0 mg/L kinetin was best for somatic embryogenesis only, but not for further plant development. After 10 d, differentiated calluses were sub-cultured on medium with various concentrations and types of carbohydrates (carbon source) in ¹MS_2j medium. A large number of plantlets (14.51±2.81 and 8.56±2.90 plants/callus) were regenerated via chemical desiccation, on MS with 3% maltose+3% sorbitol and 6% sucrose, respectively. Under dehydration on only simple MS (3% sucrose), 11.23±3.22 plants/callus were developed. Under conditions of dehydration and chemical desiccation, plant regeneration rates were higher than the calluses cultured on simple MS medium in the presence of plant growth regulator. After somatic embryogenesis, >25% plants were sterile. The protocol used here may allow maximum regeneration of normal and fertile plantlets of super basmati rice within 3 months.     

Enhancing antimicrobial properties of dyed and finished cotton fabrics

1,2,3-Benzothiazole-7-thiocarboxylic acid-S-methylester (commercially known as Actigard^® AM-87) was utilized to impart cotton fabric durable antimicrobial properties. Finishing treatment was carried out under a variety of conditions. The latter were included, effect of pH, concentration of antibacterial agents, curing temperature and curing time. The effect of fabric construction, mercerization, and dyeing with different dyestuff were also investigated. The study was also extended to investigate the technical feasibility of combining antimicrobial finishing treatment in question with other finishing treatment generally carried out on cotton fabric, like soft finishing and crease recovery finishing. The treated fabrics were monitored for antimicrobial properties before and after washing. The treated fabrics were also evaluated for the physio-mechanical properties like fabric tensile strength, elongation at break (or bursting strength for knitted fabric), wettability, crease recovery angle, whiteness index and roughness. Results obtained show that, the most appropriate conditions for treatment cotton fabric with Actigard^® are: padding the cotton fabric in aqueous solution containing 6% Actigard^® at pH 5 (adjusted using formic acid) then squeezed to wet pick up of 100%, dried at 80 °C for 5 min then cured at 100 °C for 150 s. The untreated cotton fabric did not show any antimicrobial activity towards Staphylococcus aureus or Escherichia coli. Treatment of cotton fabric with Actigard^® improves its antimicrobial properties towards S. aureus or E. coli. It is also observed that, treatment of cotton fabric with Actigard^® marginally decreases fabric tensile strength, elongation at break, roughness and WI, whereas; both wettability and crease recovery angle remain practically intact. This was observed whether the fabric was pre-mercerized or not.