Biomedical subjects

E Anderssen

Publications and source records attributed to E Anderssen.

6 recordsLinked to original sources

PubMed2001

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV.

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

Journal Article↗

PubMed2000

Stability of an epidural analgesic solution containing adrenaline, bupivacaine and fentanyl.

BACKGROUND: A low dose solution of adrenaline 2 microg x ml(-1), fentanyl 2 microg x ml(-1) and bupivacaine 1 mg x ml(-1) has been reported to give superior pain control when used for epidural analgesia after major surgery. The present paper describes the compounding and chemical stability of this triple-component solution during storage and use. METHODS: Sterile triple-component concentrates (11X) were diluted by the use of gas isolator technology to give ready-to-use infusion solutions. Eight solutions were analysed by reverse phase high-performance liquid chromatography (HPLC) methods, and assays were performed on 1, 45, 90 and 180 days after storage at 2-8 degrees C. After 180 days the solutions were subsequently stored at 22 degrees C for four days before they were reanalysed. HPLC quantification of adrenaline was also performed on samples from solutions given to 28 different patients. RESULTS: The concentration of adrenaline and fentanyl decreased approximately 3.5% from 1 to 180 days at 4 degrees C and four days at 22 degrees C. The corresponding figure for bupivacaine was an apparent increase by 2.4% in concentration. No absorption to the polypropylene plastic bags of fentanyl and bupivacaine was detected. None of the 28 samples derived from used infusion bags contained less than 95% of the declared content of adrenaline. CONCLUSIONS: The triple-component epidural analgesic solution remained stable during six months of cold storage, followed by four days of storage at room temperature. No significant degradation of adrenaline was observed in infusion solutions returned from the wards.

Adsorption↗

PubMed2000

Distribution of ascorbate in the anterior bovine eye.

PURPOSE: To analyze the ascorbate distribution in the anterior eye wall to better understand the functional significance of this compound in the eye. METHOD: Ascorbic acid was determined by high-performance liquid chromatography using an LC-10 system (Shimadzu, Kyoto, Japan). Bovine eye samples were used. RESULTS: The highest ascorbate concentration was observed in the corneal epithelium, with significantly higher values in the central (1.56 mg/g) than in the peripheral (1.39 mg/g) area. The ascorbate content was similar in the corneal stroma (0.22 mg/g), the Descemet's membrane (DM)/endothelium (0.22 mg/g), and the aqueous humor (0.21 mg/ml). By comparison, the sclera (0.15 mg/g) and the conjunctiva (0.11 mg/g) showed lower values, as did the lacrimal gland (0.09 mg/g) and the serum (0.0008 mg/ml). CONCLUSIONS: (1) Peak ascorbate concentration was observed in the central corneal epithelium covering the pupillary area. This is compatible with the idea that the ascorbate may act as an UV filter shielding internal eye structures from radiation damage. (2) The ascorbate concentration in the corneal stroma and DM/endothelium was as high as in the aqueous humor, and it is suggested that the aqueous humor plays a key role in the distribution of ascorbate to the anterior eye wall.

Animals↗

PubMed2000

UV absorption by uric acid in diurnal bird aqueous humor.

PURPOSE: To analyze the components responsible for the UV absorbance in diurnal bird aqueous humor. METHODS: The absorbance studies were carried out using a Hitachi spectrophotometer (U 2000). Uric acid was determined by high-performance liquid chromatography (LC-10 system; Shimadzu, Kyoto, Japan). Chicken and turkey eyes were examined. RESULTS: The UV absorbance in chicken aqueous was largely accounted for by the presence of protein, tryptophan, tyrosine, ascorbic acid, and uric acid. Ascorbic acid was low (23 micromol/l). Uric acid was, on the other hand, remarkably high (151 micromol/l) compared with that in mammals (cattle, 16 micromol/l). Principally the same results were obtained in chicken and turkey. CONCLUSIONS: Uric acid is a significant UV-absorbing substance in the aqueous humor of diurnal birds with its peak absorbance at 292 nm. The hypothesis that the aqueous humor acts as a UV filter seems to be valid also for the avian eye. However, in these eyes uric acid fulfills the role that ascorbic acid does in mammals.

Absorption↗

PubMed1998

Ascorbate in the corneal epithelium of diurnal and nocturnal species.

PURPOSE: To compare the amount of ascorbic acid in the corneal epithelium of various species to unveil possible differences between diurnal and nocturnal mammals. METHODS: Ascorbic acid was determined by high-performance liquid chromatography, using an LC-10 system (Shimadzu, Kyoto, Japan). RESULTS: Diurnal animals show a higher ascorbate concentration in the corneal epithelium than nocturnal animals. Ascorbate concentration is higher in the corneal epithelium than in the matching aqueous humor in diurnal and nocturnal species. The highest ascorbate concentration is found in the corneal epithelium of the reindeer. CONCLUSIONS: Ascorbate level in the corneal epithelium seems to vary in accordance with ambient radiation exposure of the respective species, just as in the aqueous humor. Both phenomena are regarded as environmental adaptations, and the ascorbic acid is suggested as protecting against photokeratitis and as acting as an ultraviolet filter for internal eye structures.

Animals↗

PubMedDate not supplied

Zherlock: an open source data analysis software.

Zherlock is an open source software that provides state-of-the-art data analysis tools to the user in an intuitive and flexible way. It is a front-end to different numerical "engines" to produce a seamless integration of algorithms written in different computer languages. Of particular interest is creating an interface to high-level scientific languages such as Octave (a Matlab clone) and R (an S-PLUS clone) to enable efficient porting of new data analytical methods. Zherlock uses advanced scientific visualization tools in 2-D and 3-D and has been extended to work on virtual reality (VR) systems. Central to Zherlock is a visual programming environment (VPE) which enables diagram based programming. These diagrams consist of nodes and connection lines where each node is an operator or a method and lines describe the flow of data between nodes. A VPE is chosen for Zherlock because it forms an effective way to control the processing pipeline in complex data analyses. The VPE is similar in functionality to other programs such as IRIS Explorer, AVS or LabVIEW.

Algorithms↗