Ethical issues in endoscopic surgery.
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Biomedical subjects
Publications and source records attributed to C Filip.
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The possibility of exciting and filtering various multipolar spin states in proton NMR like dipolar encoded longitudinal magnetization (LM), double-quantum (DQ) coherences, and dipolar order (DO) in strongly inhomogeneous static and radio-frequency magnetic fields is investigated. For this purpose pulse sequences which label and manipulate the multipolar spin states in a specific way were implemented on the NMR-MOUSE (mobile universal surface explorer). The performance of the pulse sequences was also tested in homogeneous fields on a solid-state high-field NMR spectrometer. The theoretical justification of these procedures was shown for a rigid two-spin 1/2 system coupled by dipolar interactions. Dipolar encoded longitudinal magnetization decay curves, double-quantum and dipolar-order buildup curves, as well as double-quantum decay curves were recorded with the NMR-MOUSE for natural rubber samples with different crosslink density. The possibility of using these multipolar spin states for investigations of strained elastomers by NMR-MOUSE is also shown. These curves give access to quantitative values of the ratio of the total residual dipolar couplings of the protons in the series of samples which are in good agreement with those measured in homogeneous fields.
The possibility of exciting and detecting proton NMR double-quantum coherences in inhomogeneous static and radiofrequency magnetic fields was investigated. For this purpose specialized pulse sequences which partially refocus the strongly inhomogeneous evolution of the spin system and generate double-quantum buildup and decay curves were implemented on the NMR MOUSE (mobile universal surface explorer). The theoretical justification of the method was developed for the simple two-spin-1/2 system. The performances of the same pulse sequences were also tested on a solid-state high-field NMR spectrometer. It was shown that DQ decay curves have a better signal-to-noise ratio in the initial time regime than DQ buildup curves. The double-quantum buildup and decay curves were recorded for a series of cross-linked natural rubber samples. These curves give access to quantitative values of the ratio of proton total residual dipolar couplings which are in good agreement with those measured in homogeneous fields. A linear dependence of these ratios on the sulfur-accelerator content was found.
A two-dimensional (2D) double-quantum (DQ) experiment under rotational resonance (R(2)) conditions is introduced for evaluating dipolar couplings in rotating solids. The contributions from the R(2)-recoupled dipolar interaction and the J coupling can be conveniently separated in the resulting 2D R(2)-DQ spectrum, so that the unknown dipolar coupling can readily be extracted, provided that the values of the involved J coupling constants are known. Since the measured parameters are integral intensity ratios between suitably chosen absorption peaks in the 2D spectrum, the proposed method is characterized by a reduced sensitivity to relaxation parameters. The effect of rotor-modulated terms, including chemical shift anisotropy, is efficiently averaged out by synchronizing the excitation/reconversion time with the rotor period. All of these features are demonstrated theoretically by the example of two model systems, namely, isolated spin-pairs and a three-spin system. The results of the theoretical models are applied to both (13)C and (1)H nuclei to extract dipolar couplings in uniformly (13)C labeled L-alanine and a crosslinked natural rubber.
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The combination of magic-angle spinning and multiple-pulse sequences for line-narrowing in solids with homogeneous spin interactions is analyzed using Floquet theory. It is found that, for quasi-static conditions and for special synchronization conditions, line-narrowing is possible while for other conditions destructive interference of the two techniques takes place. However, even for optimum line-narrowing conditions, fundamental limitations with respect to the achievable linewidth are found, whereas the conditions of recoupling spin interactions are more easily realized. The implications of these results with respect to improving existing line-narrowing techniques or techniques for the design of specific Hamiltonians are discussed.
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The sensitivity of the outer and cytoplasmic membranes of Escherichia coli to detergent was examined by isopycnic sucrose density gradient centrifugation. Sodium lauryl sarcosinate (Sarkosyl) was found to disrupt the cytoplasmic membrane selectively under conditions in which Triton X-100 and dodecyl sodium sulfate solubilized all membrane protein. These results were verified by gel electrophoresis; membrane proteins solubilized by Sarkosyl were identical to those of the cytoplasmic membrane. The presence of Mg(2+) during treatment with Sarkosyl was found to afford partial protection of the cytoplasmic membrane from dissolution.
Twenty-five strains of Clostridium sordellii were divided into two groups on the basis of spore fine structure. Sixteen strains formed spores with smooth tubular appendages, and nine strains formed spores which lacked appendages. The other properties of the 25 strains were relatively constant. Since the minor strain variability which was encountered did not correlate with spore appendage status, fragmentation of this species on the basis of spore appendage status is not advocated.
Ethanol is one of the most used substances that produce liver lesions. The differences between species, the pathway of administration and the genetic variation are factors that influence the response of liver to ethanol. The experiment used adult male Wistar rats and the hepatic lesions were assessed using standard histological examination. The results show an increase of triglycerides in liver cells even in acute intoxication, the most affected cells being located in the periphery of the hepatic lobule, associated with a dilatation of blood vessels.
PURPOSE: This paper is a study concerning the clinical-imagistic correlations in lacunar infarcts causes and associated lesions in these ones. We made an attempt to find out and emphasize the risk factors, causes and pathogenic mechanisms involved in lacunar syndromes. MATERIALS AND METHODS: We studied 138 patients with lacunar infarcts diagnosed by clinical examination and computer tomography. The investigation of risk factors evidenced arterial hypertension in 75 cases (54%). The clinical features of lacunar syndromes were: 1) pure motor stroke 41c; 2) pure sensory stroke 8c; 3) ataxic hemiparesis 9c; 4) dysarthria-clumsy hand 1c; 5) sensorimotor stroke 21c; 6) Landry syndrome 1c. RESULTS: We correlated the clinical manifestations and complementary investigations what enabled us to charge in determining of lacunar infarcts: focal microangiopathy-small artery disease (75c), cardio-embolic mechanism (12c), arterio-arteriolar embolic mechanism (15c). The risk factors and pathogenic mechanisms need more adequate research in order to find appropriate prevention and medical attendance.
The acute toxicity, local tolerance and pharmacokinetic properties of sulbactame manufactured by the Iaşi Antibiotic Investigation Centre, alone or in association with ampicillin or amoxicillin were tested. Some tests were made comparatively with the product Unasyn--Pfizer. The obtained data show that this beta-lactamase inhibitor has a low toxicity--DL50 i.p. in mice over 4,000 mg/kg, both alone or associated with the two semisynthetic beta-lactamic antibiotics. The local tolerance is good and the serum levels of the above mentioned associations are above towards the tested bacteria and are similar or very close to those of Unasyn. It is believed that the therapeutical use of the association sulbactame + ampicillin or sulbactame + amoxicillin is very useful in the beta-lactamase producing germs infection.
The present paper analyzes the liver trauma, underlying efficient diagnostic methods and treatment approaches. Liver trauma is frequent in Surgical Emergency Units and it is a challenge for the surgeon who has to deal with diagnosis and treatment problems and also to treat the associated lesions. The study analyzes 49 cases of liver trauma admitted in Emergency Surgery Clinic from Timisoara City Hospital between January 1995 and April 2005. A very good trained team specialized in liver surgery but also a multidisciplinary team is very important in liver trauma.
The teratogen action of Boicil tablets was studied in two animal species, rats and mice, the prefertilization and implantation stages being the main interest. Three generations of animals were followed up. The active powder suspended in distilled water (0.1 ml/10 g for mice and 1 ml/100 g for rats) was administered per os in a single dose, prepared on spot and in two doses, 2 mg/kg body weight and 20 mg kg body weight, respectively. The administered doses were equivalent to the daily maximum therapeutic dose prescribed in humans (110 mg active principle). The first gestational day was determined differently in the two species. For estimating the effect on prefertilization, Boicil tablets was administered for 5 days before making and for its effects on the number of implantations during the first 3 gestational days. The two parameters under investigation were within normal limits and all newborn animals followed up for three generations did not present pathological microscopic and gross alterations or somatic malformations. It was concluded that Boicil tablets is not teratogenic.
The effect of Boicil tablets on early embryogenesis (the first 3 gestational days), organogenesis (the 10th, 11th and 12th gestational days) and fetus (the 18th and 19th gestational days) by its intraamniotic administration was followed up in three successive generations of mice and rats. Two doses were used (2 mg/kg body weight and 20 mg/kg body weight), estimated in relation with the maximum therapeutic daily dose in man, being administered in a single dose, per os. No inborn malformations or somatic abnormalities were recorded both in mothers and in their descendents for three successive generations. It is concluded that Boicil tablets is not teratogenic.
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We investigated the influences of Li2CO3 1 g/kg i.p., MgSO4 1 g/kg i.p. and Zinc acexamate 100 mg/kg p.o. on gastric lesions induced by Platelet Activating Factor (PAF), 2 micrograms/kg i.v. in rats. Our data show that, Li+ has no a significant influence, while Mg2+ decrease significantly the PAF induced gastric lesions.
We tested the influence of 30 mg/kg/per os BN 52021, 300 micrograms/kg Cloprostenol (CIPG) and of 5 mg/kg per os LY 171883B in stress restrain and indomethacin induced ulcers in rats. The data obtained show that CIPG and LY 171883 have a significant gastroprotective action in both ulcer models. BN 52021 has a significant protective activity in stress ulcer and less in indomethacin-induced ulcers.