Elevation of plasma atrial natriuretic peptide in a neurosurgical patient with the syndrome of inappropriate secretion of antidiuretic hormone--case report.
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The authors describe a case of subarachnoid hemorrhage with hyponatremia accompanied by elevation of plasma atrial natriuretic peptide (ANP). The early phase of hyponatremia was classified as the syndrome of inappropriate secretion of antidiuretic hormone (ADH) due to subarachnoid hemorrhage. However, in the later phase, hyponatremia and natriuresis were accompanied by suppression of ADH while plasma ANP remained elevated. The patient was effectively treated with demeclocycline and hypertonic saline. The significance of ANP in the pathophysiology of increased natriuresis is discussed. (+info)
The ocular hypotensive effects of demeclocycline, tetracycline and other tetracycline derivatives.
(19/37)
Demeclocycline, tetracycline and other tetracycline derivatives lowered intraocular pressure (IOP) in rabbits following intravitreal injection, but the onset of this effect was not evident until 1 or more days after drug administration. Of the drugs tested, demeclocycline was the most active ocular hypotensive agent. Demeclocycline caused a dose-dependent decrease in IOP. The maximum IOP decrease of approximately 12 mm Hg occurred 5 days after intravitreal administration of 0.5 mg, with the effect persisting for over a week. Demeclocycline did not alter tonographically measured aqueous humor outflow facility or episcleral venous pressure. Based on calculated aqueous humor flow rates following 0.2 mg demeclocycline, a 62% decrease in aqueous humor formation occurred 7 days after intravitreal injection. The flow-to-diffusion ratio for ascorbate was reduced 54% 6 days after the intravitreal administration of demeclocycline, a change also consistent with suppression of aqueous humor formation. Anterior chamber aqueous humor protein concentration was increased 6 days after demeclocycline administration. No histologic changes were present in the treated eyes by light microscopy. Intravitreal demeclocycline similarly lowered IOP in cats, with the duration of effect lasting up to 20 days. (+info)
Phototoxicity of the tetracyclines: photosensitized emission of singlet delta dioxygen.
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The spectroscopic observation of 1268-nm emission of singlet oxygen photosensitized by tetracyclines in oxygenated solutions at room temperature is reported. In the series demeclocycline, tetracycline, and minocycline, the efficiency of singlet oxygen generation is found to parallel the clinical observation of relative frequency of phototoxicity of these antibiotics, suggesting singlet oxygen generation as the origin of their phototoxicity. (+info)
Competition between tetracycline and tRNA at both P and A sites of the ribosome of Escherichia coli.
(21/37)
Fluorescence anisotropy studies performed on 6-demethylchlortetracycline, binding to the ribosome of E. coli in competition with tRNA at the P site or at both P and A sites, have provided a quantitative assessment in situ of the interaction of this antibiotic with the A site and have demonstrated that there is also an interaction between tetracycline and the P site. (+info)
In vitro susceptibilities of Ehrlichia risticii to eight antibiotics.
(22/37)
Inhibition of the proliferation of Ehrlichia risticii cultured in murine macrophage P388D1 cells by eight antibiotics was evaluated by indirect fluorescent-antibody staining with an antiserum specific to E. risticii. There was a negative correlation between the percentage of infected cells and the log10 of the concentrations of all antibiotics examined. The ranks of the antibiotics in the order of 50% inhibitory concentrations (on a microgram-per-milliliter basis) after 48 h of exposure were as follows: demeclocycline, doxycycline, and oxytetracycline less than minocycline less than rifampin less than tetracycline less than erythromycin and nalidixic acid. When the antibiotics were removed after 48 h of incubation, continuous inhibition of proliferation was evident at 72 h. At 96 h regrowth of the organisms occurred in most of the cultures. The rate of regrowth was the highest with nalidixic acid, followed by erythromycin, at all concentrations of the antibiotic tested. Regrowth was observed with less than 0.1 microgram of minocycline per ml and less than 0.01 microgram of oxytetracycline, tetracycline, and doxycycline per ml. With more than 0.01 microgram of demeclocycline per ml, however, the inhibition persisted for up to 72 h after removal of the antibiotic. These results indicate that demeclocycline was slightly more effective than doxycycline, oxytetracycline, and minocycline in eliminating E. risticii in macrophages in vitro, whereas tetracycline and rifampin were less effective. Nalidixic acid and erythromycin were ineffective. (+info)
Triple tetracycline (Deteclo) in the treatment of chlamydial infection of the female genital tract.
(23/37)
The efficacy of treating genital Chlamydia in women using Deteclo 300 mg twice daily for seven and 21 days has been studied. Forty-four patients were treated for seven days and 20 for 21 days. Seven days of treatment was as effective in eliminating Chlamydia trachomatis from the female genital tract as 21 days. The reproducibility of the technique of isolation of C. trachomatis was assessed by delaying treatment in 10 patients for up to 156 days and find C. trachomatis still present. (+info)
International standards and international reference preparations: amphotericin B, vancomycin, capreomycin, cefalotin, demethylchlortetracycline, gentamycin, gramicidin S, kanamycin and kanamycin B, lincomycin, lymecycline, methacycline, paromomycin, rifamycin SV, ristocetin and ristocetin B, spiramycin, and triacetyloleandomycin.
(24/37)
Each of the preparations described here was obtained and evaluated at the request of a WHO Expert Committee on Biological Standardization. Unless otherwise stated, a standard procedure was used to distribute the material into individual ampoules. The procedure was as follows. Upon receipt by the National Institute for Medical Research (NIMR), London, materials were stored temporarily in the dark at a temperature of -10 degrees C or lower, and protected from moisture. At a convenient time they were brought back to room temperature, mixed, and distributed into individual neutral glass ampoules so that each ampoule contained 50-100 mg of powder. If it was known that the material was light-sensitive non-actinic glass ampoules were used. After exhaustive drying in vacuum over phosphorus(V) oxide, the ampoules were either constricted (up to 1963) or fitted with capillary leak plugs, dried for a further period under the same conditions, filled with dry nitrogen, and sealed by fusion of the glass. The total drying period varied from 8 to 38 days according to the nature of the material. After they had been tested for leaks, the ampoules were stored in the dark at -20 degrees C. (+info)