Am J Vet Res. 1988 Jul;49(7):1160-3.
Postweaning diarrhea in swine: effects of oxytetracycline on enterotoxigenic Escherichia coli infection.

Sarmiento JI, Moon HW.

USDA, Agricultural Research Service, National Animal Disease Center, Ames, IA 50010.

Investigators have found that oxytetracycline decreases the adhesion of K88+ Escherichia coli to intestinal epithelial cells in vitro. This occurs with oxytetracycline-sensitive E coli at drug concentrations less than those required to prevent growth and with E coli that are resistant to the drug. We conducted experiments to determine whether oxytetracycline alters the disease caused by an oxytetracycline-resistant K88+ enterotoxigenic strain of E coli. Oxytetracycline-treated pigs (inoculated with K88+ E coli) did not differ from nontreated pigs in the incidence or severity of diarrhea, nor in the shedding of K88+ E coli. However, during recovery, weight gain by treated pigs was slower than that of nontreated pigs. The control pigs were not inoculated with E coli, and they remained clinically normal. Oxytetracycline-treated controls gained weight faster than nontreated controls. Some controls were genetically resistant to K88+ E coli, others were susceptible. The K88-resistant oxytetracycline-treated controls gained weight faster than the K88-susceptible oxytetracycline-treated and non-treated controls.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3048158&dopt=Abstract antibiotics, tetracycline

epib.fgg.eur.nl

BACKGROUND: Recently several case reports described the association between minocycline and lupuslike syndrome. Minocycline, one of the tetracyclines, is widely used to treat acne. We aimed to examine the association of exposure to minocycline and other tetracyclines with the development of lupuslike syndrome. METHODS: We conducted a nested case-control study in a cohort of 27 688 acne patients aged 15 to 29 years, using data automatically recorded on general practitioners' office computers in the United Kingdom. Controls were matched to cases on age, sex, and practice. The main outcome was lupuslike syndrome defined as the occurrence of polyarthritis or polyarthralgia of unknown origin, with negative rheumatoid factor or latex agglutination test, positive or unmeasured antinuclear factor, elevated or unmeasured erythrocyte sedimentation rate, and absence of or unmeasured antinative DNA antibody levels. RESULTS: We identified 29 cases and selected 152 controls. Current single use of minocycline was associated with an 8.5-fold (95% confidence interval [CI], 2.1-35) increased risk of developing lupuslike syndrome compared with non-users and past users of tetracyclines combined. The risk of past exposure to any of the tetracyclines was closely similar to nonuse (relative risk, 1.3; 95% CI, 0.5-3.3). Current use of doxycycline, oxytetracycline, or tetracycline combined was associated with a 1.7-fold (95% CI, 0.4-8.1) increase of risk. The risk increased with longer use. CONCLUSION: Current use of minocycline increased the risk of developing lupuslike syndrome 8.5-fold in the cohort of young acne patients. The effect was stronger in longer-term users. However, the absolute risk of developing lupuslike syndrome seems to be relatively low.

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paratekpharm.com

A diverse collection of tetracycline derivatives has been synthesized utilizing Heck, Suzuki, and other palladium-coupling reactions via tetracycline arenediazonium and iodoarene salts. Large numbers of tetracyclines are now possible via these reactions, including numerous upper periphery derivatives of doxycycline, minocycline, sancycline, and methacycline modified at positions C7, C9, and C6-C13 on the tetracycline naphthacene ring. Application of palladium-coupling reactions to the tetracyclines has yielded new tetracycline classes with differing structural attributes, greatly increasing the structural diversity of this family of antibiotics, one of the last of the early antibiotic families to be expanded by organic and medicinal chemistry.

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Allerg Immunol (Leipz). 1984;30(2):104-9.
Inhibition of protein synthesis and lymphokine production by tetracycline.

Ganguly R, Pennock DG, Kluge RM.

This study was designed to examine the effects of tetracycline on DNA and protein synthesis by human lymphocytes treated with Con A. The effects of the drug were also assessed in terms of the in vitro production of the lymphokine, migration inhibitory factor (MIF). The results indicate that marked suppression of protein synthesis occurred in presence of tetracycline at all concentrations including clinically achievable doses. The group mean values of DNA synthesis did not show significant inhibition with lower concentrations of the drug. The marked decline in protein synthesis in tetracycline treated cultures was accompanied by a significant suppression of MIF production. Accelerated migration of macrophages was observed when the lymphocyte supernatant was produced in presence of the higher concentrations of tetracycline (75-100 microliter/ml). These observations suggest that tetracycline interfered with the in vitro correlates of cellular immunity in humans. This raises a possibility that indiscriminate use of the drug might compromise host defenses especially where long-term therapy is prescribed.

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Antimicrob Agents Chemother. 1994 Jul;38(7):1658-60.
Inhibition of protein synthesis occurring on tetracycline-resistant, TetM-protected ribosomes by a novel class of tetracyclines, the glycylcyclines.

Rasmussen BA, Gluzman Y, Tally FP.

Department of Molecular Biology, American Cyanamid Company, Pearl River, New York 10965.

One of the two major mechanisms of tetracycline resistance is ribosomal protection. Of this resistance type, tet(M) is the best characterized. Although the mechanism of tet(M) resistance has not yet been fully elucidated, it has been demonstrated that ribosomes isolated from a tet(M) strain are resistant to inhibition of protein synthesis by tetracycline. A new generation of tetracycline compounds, the glycylcyclines, that are able to inhibit protein synthesis occurring on tetracycline-resistant, TetM-protected ribosomes, as well as wild-type, tetracycline-sensitive ribosomes, have been identified.

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Cancer Lett. 1984 Nov;25(1):33-40.
The mitochondrial genetic system as a target for chemotherapy: tetracyclines as cytostatics.

Kroon AM, Dontje BH, Holtrop M, Van den Bogert C.

The mitochondrial genetic system is indispensable for the biosynthesis of the enzyme complexes involved in aerobic energy generation. Tetracyclines inhibit the expression of only the mitochondrial genes because they specifically block mitochondrial protein synthesis. A salient feature is that this inhibition occurs at the low concentration required for anti-bacterial treatment, provided that this concentration is maintained continuously. Evidence is presented that the growth of carcinogen-induced tumors can be inhibited by tetracyclines. It is further shown that the development in the cheek pouch of the Syrian hamster of a transplantable hypernephroma from human origin can be strongly retarded by tetracyclines as well. Therefore, the mitochondrial genetic system has to be reckoned as a target for chemotherapy and tetracyclines as cytostatic agents.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6518450&dopt=Abstract antibiotics, tetracycline




J Pharm Biomed Anal. 1997 Aug;15(12):1833-8.
Study on the fluorescence system of chlortetracycline-Eu-TOPO-sodium dodecyl sulfonate and the determination of chlortetracycline.

Yang J, Tong C, Jie N, Wu X, Zhang G, Ye H.

Department of Chemistry, Shandong University, Jinan, People's Republic of China.

The fluorescence system of Eu-chlortetracycline-TOPO-sodium dedecyl sulfonate was studied. It was found that chloretetracycline formed a complex with Eu(III) at pH 8.0-9.0 and then emitted the characteristic fluorescence of Eu(III). TOPO and sodium dodecyl sulfonate greatly enhanced the fluorescence intensity of the system. The experiments indicated that under the optimum determining conditions a linear relationship was obtained between the fluorescence intensity and chlortetracycline concentration in the range of 2.0 x 10(-8)-1.0 x 10(-5) M. The detection limit was 6.0 x 10(-9) M. In addition, the luminescence mechanism of the complex system has been discussed.

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Invest Ophthalmol Vis Sci. 2000 Dec;41(13):4281-7.
Tetracycline-inducible system for photoreceptor-specific gene expression.

Chang MA, Horner JW, Conklin BR, DePinho RA, Bok D, Zack DJ.

Jules Stein Eye Institute, Department of Neurobiology, Brain Research Institute, University of California, Los Angeles, USA.

PURPOSE: To develop a system for inducible photoreceptor-specific gene expression in transgenic mice. The tetracycline regulatory system was chosen because it possesses the useful property of direct control of gene expression through use of an exogenous agent, doxycycline, a tetracycline derivative. METHODS: Transgenic mice were generated that carried the reverse tetracycline-controlled transactivator under the control of the photoreceptor-specific promoters for rhodopsin and interphotoreceptor retinoid-binding protein. These animals were crossed with transgenic mice carrying the lacZ reporter gene under control of the tetracycline operator cassette, creating doubly transgenic mice. Doxycycline was administered to induce expression of the reporter gene. Reporter assays were then performed to evaluate lacZ expression. RESULTS: Doxycycline administration led to photoreceptor-specific expression of the lacZ reporter gene in the doubly transgenic mice. X-gal staining was restricted to photoreceptor inner segments and synaptic termini. Induction could be achieved by addition of the drug to the animals' drinking water or by intravitreal injection. Induction was noted within 24 hours of doxcycline administration. Because of variability among animals, there was an approximate correlation, but not a clean dose-response curve relating drug dose to level of reporter expression. CONCLUSIONS: A transgenic system for inducible photoreceptor-specific gene expression has been developed. This system is currently being exploited to study the effects of regulated expression of genes of biological interest.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11095627&dopt=Abstract antibiotics, tetracycline