Am Rev Respir Dis. 1981 Jul;124(1):65-7.
The effect of common sclerosing agents on the rabbit pleural space.

Sahn SA, Good JT Jr.

New Zealand white rabbits received intrapleural instillations of either tetracycline (7, 20, and 35 mg/kg), HCI (0.01N), quinacrine (10 mg/kg), nitrogen mustard (0.2 mg/kg), bleomycin (1.5 mg/kg), or NaOH (0.5%). All sclerosing agents produced a neutrophil-predominant, exudative pleural effusion within 12 h of instillation. By 48 h the pleural fluid was predominantly mononuclear. Despite the large pH range of the sclerosing agents (tetracycline, 2.0; NaOH, 13.0), the pleural fluid pH was always between 7.40 and 7.49 during the 144-h observation period. There was no difference in protein concentration, leukocyte count, or neutrophil differential with either the 3 different doses of tetracycline or the 5 other sclerosing agents. Autopsies at 30 days showed that only the 35 mg/kg dose of tetracycline produced pleural symphysis. We concluded that the common sclerosing agents produce a similar type of pleural effusion, but only tetracycline leads to pleural fibrosis; this effect appears to be dose-dependent. The pH of the sclerosing agent per se probably has little effect on the development of pleural symphysis.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6167181&dopt=Abstract antibiotics, tetracycline




Clin Ther. 1984;6(2):163-9.
A comparison of cefaclor and tetracycline in the treatment of bacterial bronchitis.

Hurst DJ.

Cefaclor and tetracycline were compared in a single-blind study designed to treat patients with acute bacterial bronchitis and acute exacerbations of chronic bronchitis. Twenty-five pathogens (including 19 of Haemophilus influenzae and four of Streptococcus pneumoniae) were obtained from sputum samples of 48 patients. No pathogen could be cultured from the sputum of 23 patients. All of these pathogens were susceptible to cefaclor, while 12 (63%) of the 19 H influenzae isolates and three of the four S pneumoniae isolates were resistant to tetracycline. When the susceptibility of the 25 isolates to other commonly used antibacterials was tested, 18 isolates of H influenzae were resistant to erythromycin and one was resistant to ampicillin. (One H influenzae isolate was not tested for erythromycin susceptibility.) The four isolates of S pneumoniae were susceptible to erythromycin and ampicillin. Satisfactory results were achieved in 21 of the 23 patients receiving cefaclor. After four to six days of cefaclor therapy, the other two patients were diagnosed as having bronchopneumonia, and parenteral antibiotic therapy was instituted. Of the 25 patients assigned to the tetracycline regimen, three with resistant H influenzae had unsatisfactory clinical responses and required parenteral antibiotic therapy for recovery. Although patients were randomly assigned to therapy, only three of the 16 patients infected with tetracycline-resistant organisms were assigned to the tetracycline group, and all three failed to respond to treatment. Had the patients been more evenly distributed according to susceptibilities, it is possible that more treatment failures would have occurred in the group receiving tetracycline.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6231104&dopt=Abstract antibiotics, tetracycline




Z Lebensm Unters Forsch. 1989 Mar;188(3):227-31.
A rapid fluorimetric screening method for chlortetracycline, oxytetracycline and tetracycline in pig meat and kidney tissues.

Haagsma N, Mengelers MJ.

Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.

A rapid fluorimetric screening method for chlortetracycline, oxytetracycline and tetracycline in pig meat and kidney tissues is described. After sonication-aided extraction with ethyl acetate, the extract is cleaned and concentrated by means of solid-phase extraction using an aromatic sulphonic acid cation-exchange column. Subsequent screening is carried out by fluorimetry. The detection level is estimated to be about 0.05 mg kg-1 for oxytetracycline, 0.1 mg kg-1 for chlortetracycline and 0.2 mg kg-1 for tetracycline.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2711756&dopt=Abstract antibiotics, tetracycline




Biochemistry. 1995 Jan 10;34(1):7-12.
Site-specificity of the second-site suppressor mutation of the Asp-285-->Asn mutant of metal-tetracycline/H+ antiporter of Escherichia coli and the effects of amino acid substitutions at the first and second sites.

Someya Y, Niwa A, Sawai T, Yamaguchi A.

Division of Microbial Chemistry, Faculty of Pharmaceutical Sciences, Chiba University, Japan.

The deleterious effect of the mutation of Asp-285 to Asn of the metal-tetracycline/H+ antiporter (TetA) of Escherichia coli is suppressed by the second-site mutation of Ala-220 to an acidic amino acid residue (Yamaguchi, A., O'yauchi, R., Someya, Y., & Sawai, T. (1993) J. Biol. Chem. 268, 26990-26995). In this study, site-specific second-site Glu mutants as to 11 different positions around position 220 were established from the Asp-285-->Asn mutant TetA protein. Among them, only the Ala-220-->Glu mutant completely suppressed the deleterious effect of the Asp-285-->Asn mutation, indicating that position 220 is highly specific for the suppression. Although E. coli cells producing second-site Glu mutants as to positions 213, 216, 217, 218, 219, 221, 222, and 223 of the Asn-285 mutant were as tetracycline sensitive as the host cells without TetA, Gly-224-->Glu and Pro-227-->Glu second-site mutants of the Asn-285 mutant conferred low-level tetracycline resistance, the levels decreasing in this order. These two positions and position 220 are on the same side of putative transmembrane helix VII. The Phe-289-->Asp mutation, which is located at a position one-alpha-helical-turn downstream from Asp-285 in the same putative helix, IX, did not suppress the Asn-285 mutation. The introduction of an acidic residue at the second site was essential for suppression of the Asn-285 mutation because Lys-220 and Gln-220 second-site mutants of the Asn-285 mutant showed very low tetracycline resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7819225&dopt=Abstract antibiotics, tetracycline




Biochem Biophys Res Commun. 2003 Apr 25;304(1):167-75.
Tetracycline-regulated secretion of human insulin in transfected primary myoblasts.

Scougall KT, Shaw JA.

Diabetes Research Group, School of Clinical Medical Sciences, University of Newcastle upon Tyne, Framlington Place, NE2 4HH, Newcastle upon Tyne, UK.

A mechanism for safely regulating transgene expression will be necessary for gene therapy approaches to endocrine disorders. In this study, a two-plasmid tetracycline-inducible system was used to regulate expression of human proinsulin (hppI1) and a mutated proinsulin construct (hppI4, allowing cleavage by furin) in primary rat soleus myoblasts. In hppI1 and hppI4 transient transfections, the presence of 0.01 and 0.1 microg/ml tetracycline for 48 h inhibited pro/insulin secretion to 19-27% and 7-12%, respectively, compared to tetracycline untreated myoblasts. Following a 48 h tetracycline incubation (1.0 microg/ml), pro/insulin secretion in hppI1 and hppI4 transfected myoblasts was reduced to <4% of that in cells incubated without tetracycline. Pro/insulin secretion equivalent to that of untreated cells was restored following tetracycline withdrawal and incubation for a further 72 h. Conversion of proinsulin to insulin in transfected myoblasts was <1% for hppI1 and >45% for hppI4. In conclusion, regulated insulin secretion has been achieved in a dose-dependent and reversible manner in primary myoblasts.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12705902&dopt=Abstract antibiotics, tetracycline




J Mol Endocrinol. 2003 Jun;30(3):331-46.
Tetracycline-regulated secretion of human insulin in a transfected non-endocrine cell line.

Scougall KT, Maltin CA, Shaw JA.

Department of Medicine and Therapeutics, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen, Scotland, UK.

Long-term constitutive secretion of insulin by implantation of ex vivo transfected cells such as fibroblasts or myoblasts or in situ by intramuscular injection of naked plasmid DNA provides a potential approach to gene therapy for diabetes mellitus. A mechanism for regulating insulin secretion will be necessary to realize the therapeutic potential of this approach. A second obstacle is the inability of non-endocrine host cells to fully process proinsulin. Therefore, alteration of the wild-type cDNA will be necessary to achieve processing of proinsulin by endogenous endoproteases within these cells. The cDNAs for beta-galactosidase (beta), human wild-type proinsulin (hppI1) and a mutated construct (hppI4), in which the dibasic PC2 and PC3 cleavage sites had been altered to form furin cleavage sites, were sub-cloned into four vectors (pCR3, pVR1012, pIRES, pTRE), including a tetracycline responsive plasmid (pTRE) that requires co-transfection with another plasmid encoding a transactivator (pTet-off) for transgene expression. Transient transfection of the COS-7 fibroblast cell line with these constructs was performed using DEAE-dextran and liposomes. Analysis of vector efficiencies revealed that pTRE/pTet-off>pIRES>pCR3>pVR1012. Further analysis demonstrated total pro/insulin secretion of 2.33 ng/10(6) cells/24 h with > or =25% processed to insulin in hppI-1.pTRE/pTet-off-transfected cells compared with 0.39 ng/10(6) cells/24 h and >70% processing in hppI-4.pTRE/pTet-off-transfected cells. In co-transfection studies with pTRE-hppI1/pTet-off and pTRE-hppI4/pTet-off constructs, pro/insulin secretion was inhibited to 65-66% and 36-38% of control (100%) in the presence of 0.01 and 0.1 microg/ml tetracycline respectively over a 24-h incubation period. Furthermore, reversal of tetracycline inhibition was demonstrated for pTRE-hppI1/pTet-off- and pTRE-hppI4/pTet-off-transfected cells. After a 48-h incubation with 1.0 microg/ml tetracycline, total pro/insulin levels were 10 and 14% compared with untreated cells respectively. On tetracycline removal, total proinsulin levels increased and were equivalent to untreated groups 72 h later. In conclusion, regulation of fully processed human insulin secretion has been achieved in a transiently transfected non-endocrine cell line.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12790803&dopt=Abstract antibiotics, tetracycline




J Exp Zool. 1978 Jan;203(1):89-98.
In vitro inhibition of mouse dental development by tetracycline.

Kerley MA, Kollar EJ.

Embryonic molars and incisors were dissected from mandibles of 15-day post-fertilization C57BL/10 mouse embryos and were cultured in vitro for six days on agar-solidified Eagle's basal medium. Experimental explants were cultured on medium which was the same as the control except that 50, 75 or 100 microgram/ml tetracycline was added. Treated explants of both incisors and molars were suppressed in development and reduced in size. Enamel organs and dental papillae of all tooth germs subjected to higher tetracycline concentrations were abnormal in structure and differentiation of ameloblasts and odontoblasts was inhibited. Explants treated with higher dosage levels of the drug were more severely affected than those exposed to lower concentrations. Recovery from the suppression induced by tetracycline was observed in explants transferred to control medium for four days of growth following treatment. Differentiated ameloblasts and odontoblasts observed in the recovering tooth germs indicated that the inhibition in development was temporary. The results of this study showed that tetracycline can alter dental development in vitro prior to mineralization. The observed inhibition may be related to a disruption of collagen biosynthesis which is thought to play a role in the controlling epithelial-mesenchymal interaction involved in tooth germ morphogenesis.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=624925&dopt=Abstract antibiotics, tetracycline




Antibiotiki. 1975 Jan;20(1):74-7.
[Study of the antibiotic sensitivity of the Shigellae, pathogenic Escherichia, Proteus and Staphylococcus isolated from young children in Tbilisi with acute intestinal diseases]

[Article in Russian]

Lomtadze ZD.

Sensitivity of Shigella, pathogenic Escherichia, Proteus and Staphylococcus isolated from children with acute intestinal diseases was studied with respect to antibiotics widely used in medical practice: streptomycin, levomycetin, tetracycline, chlortetracycline, oxytetracycline and neomycin. The antibiotic sensitivity was determined with the method of indicator discs. It was found that sensitivity of shigella was: 44 percent to streptomycin, 69.5 per cent to levomycetin, 18.5 per cent to tetracycline, 18.5 per cent to chlortetracycline, 23 per cent to oxytetracycline and 94 per cent to neomycin. Sensitivity of pathogenic Eschericia was 28, 33, 14, 14, 25 and 74 per cent, sensitivity of staphylococci was 46, 56.5, 21, 21, 31.5 and 89.5 per cent, sensitivity of Proteus was 15, 31.5, 3.5, 3.5, 7.5 and 52.5 per cent respectively. Cross resistance with respect to tetracyclines was found in all the microbes studie. Intragenera differences in the antibiotic sensitivity were observed among Shigella and pathogenic Escherichia.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=123726&dopt=Abstract antibiotics, tetracycline