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[en] Calculations of Raman spectra were performed in the case of four furanocoumarins: psoralen, bergapten, xanthotoxin, and isopimpinellin. The Raman bands were assigned by using the results for wavevectors also obtained through these calculations. It is shown that an easy distinction between the four compounds can be obtained by the analysis of the higher wavenumber region of the spectrum where the stretching modes of atoms pertaining to the radicals appear. The use of the other spectral regions is possible for this task, but at the expense of some additional reasoning
[en] This paper determines the optimum quantity of heparin sodium added to nonionic low-osmolarity contrast material to prevent clot formation when mixed with venous blood. Varying concentrations of heparin sodium, from 1 to 50 μm/mL were added to 5-mL samples of nonionic contrast material. Following the addition of 1 mL of fresh venous blood, the samples were examined at intervals for visible clot formation over a 36-hour period. Venous blood alone, a 1:5 dilution of venous blood in normal saline, and a 1:5 dilution of venous blood in nonionic contrast material were used as controls
[en] For decades the therapeutic properties of psoralens were related to their photochemical reactions with DNA and RNA. Such approach, although fruitful in treatments, did not explain satisfactorily the way of healing of the multitude of diseases manifested through skin disorders. The new research field presented in our review is directed to another target: the lipid components of the cell. The studies on the photobiology of phospholipids may help to elucidate the phototoxic and pigment including activity of psoralens. (author). 31 refs, 6 refs
[en] In vitro mutagenesis of functional DNA gene fragments by covalently reactive agents permits one in principle to examine the consequent alterations in DNA sequence directly. I have carried out selective mutagenesis of the tetracycline resistance gene in the plasmid pBR322 using the long wavelength UV light activated reaction of 4,5',8-trimethylpsoralen (TMP). The mutagenized DNA sequence was the EcoR1-Hind III restriction fragment in the vicinity of the Tcsup(R) promoter. Two classes of mutants were obtained. One exhibited a high level of Tc resistance (40-60 μg/ml) but still lower than the wild-type. Interestingly, these showed no sequence alterations at all in the vicinity of the TMP-reacted fragment. The other class of mutants exhibited low levels of drug resistance (< 20 μg/ml) and two of those that were sequenced were found to contain a 15-base pair insertion to the right of the original Hind III site. Under the conditions used, psoralen plus UV light treatment appears to be capable of inducing substantial frame-shifts in DNA. (orig.)
BackgroundWe assessed the feasibility and safety of single-site laparoscopic surgery for patients with colorectal cancer who required perioperative heparinization.
MethodsThis retrospective study reviewed the medical records of 390 patients who underwent single-site laparoscopic surgery for colorectal cancer from January 2010 to December 2016. Antithrombotic drugs were stopped preoperatively and heparin was administered according to the operative risk of each patient, based on consultation with the cardiologist physician or neurosurgeon. Propensity score modeling was utilized to adjust for baseline characteristics.
ResultsOf 390 patients, 29 were treated with standard bridging intravenous heparin therapy. Propensity matching identified 119 patients: 22 patients in the heparinization group and 97 in the control group. The matched groups were not significantly different in operation times, bleeding volumes, or conversion rate. The mean postoperative hospital stay was 17.9 days in the heparinization group and 9.5 days in the control group (p = 0.034). Postoperative bleeding was observed in 4 patients (18.2%) in the heparinization group and 11 patients (11.4%) in the control group (p = 0.646), while other complications were similar in the two study groups (p = 0.502). Of these other complications, thromboembolic events were observed in two patients in the heparinization group and one patient in the control group.
ConclusionsWe found that single-site laparoscopic surgery for colorectal cancer with heparinization was feasible and safe. Heparinization did not increase the risk of postoperative bleeding complications, but postoperative hospital stay was prolonged.
[en] Dynamical solvation data recently obtained with the probe solute coumarin 153 are used to test the reliability of dielectric continuum models for estimating dielectric friction effects. In particular, the predictions of the Nee endash Zwanzig theory of rotational dielectric friction are examined in some detail. The analysis undertaken here uncovers an error made in virtually all previous applications of the Nee endash Zwanzig formalism. The error involves neglect of the solvent close-quote s electronic polarizability when calculating dielectric friction constants. In highly polar solvents the effect of this neglect is shown to be minor, so that the results of past studies should not be appreciably altered. However, in weakly polar and especially in nondipolar solvents, the proper inclusion of electronic polarizability terms is essential. The equivalence between the Nee endash Zwanzig theory of dielectric friction and more general continuum treatments of polar solvation dynamics is also demonstrated. This equivalence enables the use of solvation data to test the reliability of the Nee endash Zwanzig description of electrical interactions between a solute and solvent that form the core of this and related continuum theories of dielectric friction. Comparisons to experimental data show that, with the important exception of nondipolar solvents, such continuum treatments provide reasonably accurate (±40%) predictors of time-dependent solvation and/or dielectric friction. copyright 1997 American Institute of Physics
[en] Recent data indicate that heparin may act as an immunomodulator. In this paper we have analyzed the effect of this agent on human B cell proliferation ''in vitro'' induced by ''S. aureus'' Cowan. The action of heparin is complex, but there was a trend for inhibition of B cell responses obtained from defibrinated but not heparinized blood samples. This suggest that heparin interacts with platelet products (growth factors, cytokines) and the results of such interactions determine the final effect. (author). 6 refs, 4 figs
[en] Pattern formation at the solid-liquid interface of a growing crystal was studied in directional solidification using a perturbation technique. We analyzed both experimentally and numerically the stability range and dynamical selection of cellular arrays of 'doublets' with asymmetric tip shapes, separated by alternate deep and shallow grooves. Applying an initial periodic perturbation of arbitrary wavelength to the unstable planar interface allowed us to force the interface to evolve into doublet states that would not otherwise be dynamically accessible from a planar interface. We determined systematically the ranges of wavelength corresponding to stable singlets, stable doublets, and transient unstable patterns. Experimentally, this was accomplished by applying a brief UV light pulse of a desired spatial periodicity to the planar interface during the planar-cellular transient using the model alloy Succinonitrile-Coumarin 152. Numerical simulations of the nonlinear evolution of the interface were performed starting from a small sinusoidal perturbation of the steady-state planar interface. These simulations were carried out using a computationally efficient phase-field symmetric model of directional solidification with recently reformulated asymptotics and vanishing kinetics [A. Karma and W.-J. Rappel, Phys. Rev. E 53 R3017 (1996); Phys. Rev. Lett. 77, 4050 (1996); Phys. Rev. E 57, 4323 (1998)], which allowed us to simulate spatially extended arrays that can be meaningfully compared to experiments. Simulations and experiments show remarkable qualitative agreement in the dynamic evolution, steady-state structure, and instability mechanisms of doublet cellular arrays. copyright 1998 The American Physical Society
[en] We have synthesized a series of 8-[3H]methoxypsoralens in which methyl and hydrogen are systematically varied at the 4- and 5'-positions. Analysis of the products resulting from the photoaddition of these four psoralens with the nucleic acid poly(dA-dT) reveals that the product distribution depends on the presence or absence of a 4-methyl substituent. Compounds with the 4-methyl group show an overwhelming preference (approximately 98%) for addition to the furan double bond, while compounds without the 4-methyl show a substantial amount (approximately 18%) of addition to the pyrone double bond