Some pharmacological aspects of a new water-soluble tetracycline

The pharmacological properties of a new derivative of tetracycline have been described. This water-soluble compound has a low toxicity, is stable, and lacks the local side-effects common to other derivatives of tetracycline.

Trichloroacetic acid in Norway spruce/soil-system. II. Distribution and degradation in the plant

Independently from its origin, trichloroacetic acid (TCA) as a phytotoxic substance affects coniferous trees. Its uptake, distribution and degradation were thus investigated in the Norway spruce/soil-system using 14C labeling. TCA is distributed in the tree mainly by the transpiration stream. As in soil, TCA seems to be degraded microbially, presumably by phyllosphere microorganisms in spruce needles. Indication of TCA biodegradation in trees is shown using both antibiotics and axenic plants.

[Effects some drugs of re-epithelialization in the early postoperative period after photorefraction keratectomy]

Terms of re-epithelialization, severity of the painful syndrome, intensity of corneal "crepe" (opacity) are assessed in myopic patients treated by maxitrol, eubetal, colbiocin ointments and maxitrol eyedrops in the early postoperative period after photorefraction keratectomy. The crepe intensity was assessed routinely according to a clinical score: 0) transparent cornea, 1) trace crepe; 2) moderate crepe; and 3) intensive crepe. Biomicroscopy on day 4 after photorefraction keratectomy showed complete epithelialization in 91.7% patients after colbiocin ointment, in 91.% after maxitrol eyedrops, 87% after eubetal ointment, and 82.6% after maxitrol ointment. The least corneal opacity (0 and 0-1) was observed after eubetal ointment and maxitrol eyedrops. The mean score for pain was virtually the same in all groups; in the colbiocin ointment group more patients complained of pain for more than 24 h in comparison with other groups.

[Eye ointments eubetal and colbiocin in the treatment of chlamydial conjunctivitis]

The above ointments were used for local treatment of chlamydial conjunctivitis in 325 patients. The results demonstrated their high efficacy, good tolerance, advantages over tetracycline ointment, and absence to toxic allergic reactions.

[The intraoperative visualization of the bile ducts by the use of fluorescent substances. A feasibility study]

Iatrogenic bile duct injury during cholecystectomy is the most serious complication of this surgical procedure. Initial reports suggest that this complication is particularly problematic during laparoscopic cholecystectomy. Proper identification of biliary anatomy in the subhepatic region is the only way to avoid this severe complication. The potential benefit from a simple, reliable method for intraoperative delineation of biliary anatomy is self-evident. In this experimental work the Authors-study the possibility and the feasibility of intraoperative biliary tree imaging with two fluorescent molecules (rolitetracyclin and fluorescin).

Detection of acute myocardial infarction in spontaneously hypertensive rats by 99mTc-pyrrolidino methyl tetracycline

The myocardial infarct induced by isoproterenol in spontaneously hypertensive rats accumulates higher activities of 99mTc-PM tetracycline compared with the cardiac infarct in normotensive rats caused by the same method. The isoproterenol model of the myocardial necrosis was induced in intact rats without opening the thorax and is a convenient method for experimental radioisotope studies.

Bone changes incident to blade-vent implants

This research was undertaken to study the dynamics of bone changes in relation to endosseous blade-vent implants with vital labeling technique. Three mandibular premolars were bilaterally extracted in six two years old dogs. Subsequently each healed edentulous space was implanted with a titanium endosteal blade. One blade in each dog had the post extending into the mouth; the other had the post cut at the level of the neck and covered by the mucoperiosteal flap. The animals received I.V. Pyrrolidin-Methyl-Tetracycline and Alizarine Red S labelings at 15 and 30 days intervals. Dogs 1, 3 and 5 were sacrificed on the 97th day; dogs 2, 4 and 6 on the 52nd day. On ground sections of the mandibular bone which included the blades under U.V. light, it was observed that the implants were surrounded by remodeled trabecular bone of cancellous nature containing the labeling lines of Tetracycline (yellow) and Alizarine (red). The bone-metal interface consisted mainly of a thick layer of non mineralized tissue of about 70 micrometer. The labeling results showed that the new bone apposition began early (at least by the 15th day) and continued for a long time, being still present at the moment of the last injection (90th day). No difference was recognized between the bone responses to the implants jutting out and those submerged. This confirms that implant failure is mainly linked to irregular traumatism and inflammatory infiltration which occurs over a more prolonged duration.

Kinetics of drug decomposition. Part 45. Logk--pH profile for rolitetracycline degradation

UV spectrophotometry and fluorometry were applied for an examination of rolitetracycline (RT) degradation at pH's ranged from ca 0-8 to 13-0. It was demonstrated that these methods enable to follow the rate of degradation of tetracycline formed in the course of RT hydrolysis. However, they do not allow to monitor the hydrolysis of RT to tetracycline. Application of the so-called "subtraction technique" permits to calculate the rate constants for the total, reversible epimerization reaction and for the subsequent degradation of the resultant products. A rate equation derived for RT degradation in an alkaline medium beginning at pH 10-5 contains a term second-order in the hydroxide ion. Such a relationship was not yet observed in the course of an antibiotic degradation.

Kinetics of drug decomposition. Part 48. Specific acid-base hydrolysis of rolitetracycline

Using chromatographic-spectrophotometric method, the effect of H+ and OH- ions on the rate of hydrolysis of rolitetracycline (RT) to tetracycline (T) at 20degreeC was investigated. The advantage of this analytical procedure over the direct fluorescence or UV absorption measurements of RT solutions during the kinetic investigations in HCl medium was demonstrated. The catalytic rate constants (kH+ and kOH-) for the hydrolytic degradation of RT under oxygen-free conditions are given.