Remarkable isomer-selective gelation of aromatic solvents by a polymorph of a urea-linked bile acid-amino acid conjugate

We report an unusual, isomer-selective gelation of aromatic solvents by a polymorph of a urea-linked bile acid-amino acid conjugate. The gelator showed selectivity towards gelation of 1,2-disubstituted aromatic solvents.

Hydrogelation of bile acid-peptide conjugates and in situ synthesis of silver and gold nanoparticles in the hydrogel matrix

Fabricating supramolecular hydrogels with embedded metal nanostructures is important for the design of novel hybrid nanocomposite materials for diverse applications such as biosensing and chemosensing platforms, catalytic and antibacterial functional materials etc. Supramolecular self-assembly of bile acid-dipeptide conjugates has led to the formation of new supramolecular hydrogels. Gelation of these molecules depends strongly on the hydrophobic character of the bile acids. The possibility of in situ fabrication of Ag and Au NPs in these supramolecular hydrogels by incorporating Ag+ and Au3+ salts was investigated via photoreduction. Chemical reductions of Ag+ and Au3+ salts in the hydrogels were performed without adding any external stabilizing agents. In this report we have shown that the color, size and shape of silver nanoparticles formed by photoreduction depend on the amino acid residue of the side chain.

Blanchiert oder Gegart? - Die Einstufung erhitzter Muscheln (Perna canaliculus) durch Eiweißuntersuchung

The evaluation of heated mussels by protein analysis makes clear that the methods used allow a differentiation between mussel tissues which had experienced different degrees of heating. It could be verifiyed by both, the analysis of enzyme activities and differential scanning calorimetry that the investigated trade products were only blanched and not completely well done cooked.

Characterisation of neurons in the pedal ganglia of the green-lipped mussel, Perna canaliculus, using antibodies raised against neuropeptides and neurotransmitters involved in gastropod egg-laying behaviour and bivalve reproduction and spawning

To characterise central neurons in the pedal ganglia of both male and female green lipped mussel, Perna canaliculus immunohistochemical techniques were used. Mollusc antibodies were used against neuropeptides and neurotansmitters known to control reproduction and spawning. Anti-ELH and anti-APGWamide showed very strong immunoreactivity in small type of neurons. Anti-5-HT and anti-DA immunoreactivity was mostly in large type of neurons. The labelled neurons are consistent with descriptions of neurosecretory cells implicated in the control of reproduction and spawning on the basis of earlier histological staining techniques used in this species. The use of selective immunological markers for peptides and amines appears to be a, promising tool for further characterisation of neurosecretory cells, and to isolate an'tl characterise neuropeptides and other biologically active materials involved in the control of reproduction in Perna canaliculus.

Isolation of bile from fish and identification by thin layer chromatography

The paper deals with the collection of gall bladders, isolation of bile and identification of the constituents of the bile salts from different fishes. The yield of bile contents from fresh water fishes rohu, mrigal and catla was compared with that from marine fishes seer, tuna, shark and sardine. Considerable variation in yield was showed between marine and fresh water fish as well as between the species in both groups. It ranged from 0.04 to 0.06% of the body weight of fish in calla, mrigal and rohu. The bile constituents from rohu and mrigal were analysed by thin layer chromatography. The result showed that bile of rohu and mrigal contains mainly taurine derivative of lithocholic acid.

Neurons characterization in the cerebral ganglia of the green-lipped mussel, Perna canaliculus, using antibodies raised against neuropeptides and neurotransmitters involved in gastropod egg-laying behaviour and bivalve reproduction and spawning

Immunohistochemical techniques were used to characterise central neurons in the cerebral ganglia of both male and female Perna canaliculus. We used mollusc antibodies raised against neuropeptides and neurotransmitters known to control reproduction and spawning. Anti-ELH and anti-APGWamide showed very strong immunoreactivity in small type of neurons. Anti-5-HT and anti-DA immunoreactivity was mostly in large type of neurons. The labelled neurons are consistent with descriptions of neurosecretory cells implicated in the control of reproduction and spawning on the basis of earlier histological staining techniques used in this species. The use of selective immunological markers for peptides and amines appears to be a promising tool for further characterisation of neurosecretory cells, and to isolate and characterise neuropeptides and other biologically active materials involved in the control of reproduction in Perna canaliculus.

Biodegradation of poly(L-lactide-co-glycolide) tube stents in bile

The objective of this study was to evaluate degradation behavior and the feasibility of biodegradable polymeric stents in common bile duct (CBD) repair and reconstruction. Various molar ratios of lactide (LA) and glycolide (GA) in poly(L-lactide-co-glycolide) (PLGA) were synthesized and processed into a circular tubing of similar to 10.0 mm outer diameter and a wall thickness of about 2.0 mm.

Feasibility of biodegradable PLGA common bile duct stents: An in vitro and in vivo study

The current study investigates the feasibility of using a biodegradable polymeric stent in common bile duct (CBD) repair and reconstruction. Here, poly(l-lactide-co-glycolide) (PLGA, molar ratio LA/GA = 80/20) was processed into a circular tube- and dumbbell-shaped specimens to determine the in vitro degradation behavior in bile. The morphology, weight loss, and molecular weight changes were then investigated in conjunction with evaluations of the mechanical properties of the specimen. Circular tube-shaped PLGA stents with X-ray opacity were subsequently used in common bile duct exploration (CBDE) and primary suturing in canine models. Next, X-ray images of CBD stents in vivo were compared and levels of serum liver enzymes and a histological analysis were conducted after stent transplantation. The results showed that the PLGA stents exhibited the required biomedical properties and spontaneously disappeared from CBDs in 4-5 weeks. The degradation period and function match the requirements in repair and reconstruction of CBDs to support the duct, guide bile drainage, and reduce T-tube-related complications.

INVESTIGATION ON MECHANISMS FOR THE ELECTROOXIDATION OF SOME BILE-PIGMENTS BY SPECTROELECTROCHEMISTRY

The electrooxidation behavior of bilirubin (BR), biliverdin (BV), purpurin (Pu), and choletelin (Ch in dimethylformamide (DMF) have been investigated bv voltammetry, in situ electron spin resonance (ESR) thin-layer spectroelectrochemistry and especially i

Enhancement of atmospheric pressure chemical ionization for the determination of free and glycine-conjugated bile acids in human serum

A highly sensitive and accurate method based on the precolumn derivatization of bile acids (BA) with a high ionization efficiency labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-ethyl-benzenesulfonate (BDEBS) coupled with LC/MS has been developed. After derivatization, BA molecules introduced a weak basic nitrogen atom into the molecular core structure that was readily ionized in commonly used acidic HPLC mobile phases. Derivatives were sufficiently stable to be efficiently analyzed by atmospheric pressure chemical ionization (APCI)-MS/MS in positive-ion mode. The MS/MS spectra of BA derivatives showed an intense protonated molecular ion at m/z [M + H](+). The collision-induced dissociation of the molecular ion produced fragment ions at [MH - H2O](+), [MH - 2H(2)O](+), [MH - 3H(2)O](+). The characteristic fragment ions were at m/z 320.8, 262.8, and 243.7 corresponding to a cleavage of N - CO, O - CO, and C - OCC, respectively, and bonds of derivatized molecules. The selected reaction monitoring, based on the m/z [M + H]+ -> [MH - H2O](+), [MH - H2O](+), [MH - 2H(2)O](+), [MH-3H(2)O](+), 320.8, 262.8, and 243.7 transitions, was highly specific for the BA derivatives. The LODs for APCI in a positive-ion mode, at an S/N of 5, were 44.36-153.6 fmol. The validation results showed high accuracy in the range of 93-107% and the mean interday precision for all standards was < 15% at broad linear dynamic ranges (0.0244-25nmol/mL). Good linear responses were observed with coefficients of > 0.9935 in APCI/MS detection. Therefore, the facile BDEBS derivatization coupled with mass spectrometric analysis allowed the development of a highly sensitive and specific method for the quantitation of trace levels of the free and glycine-conjugated BA from human serum samples.

Comparative proteomics of excretory-secretory proteins released by the liver fluke Fasciola hepatica in sheep host bile and during in vitro culture ex host

Russell M. Morphew, Hazel A. Wright, E. James LaCourse, Debra J. Woods and Peter M. Brophy (2007). Comparative proteomics of excretory-secretory proteins released by the liver fluke Fasciola hepatica in sheep host bile and during in vitro culture ex host. Molecular and Cellular Proteomics, 6 (6), 963-972. Sponsorship: BBSRC / EU RAE2008