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At least 253 records · Page 14Linked to original sources

A double-blind comparison of dezocine and morphine in patients with acute renal and ureteral colic.

The safety and analgesic efficacy of dezocine and morphine in the treatment of acute renal or ureteral colic due to calculi were evaluated in 2 multicenter, double-blind studies, comparing 10 mg. dezocine and 10 mg. morphine in 88 patients, and 15 mg. dezocine and 10 mg. morphine in 61 patients. All patients received an intramuscular injection of the test drug, and pain intensity and pain relief were evaluated through 4 hours after drug administration. Vital signs, degree of sedation and adverse effects also were recorded. Mean efficacy scores were virtually identical for 10 mg. dezocine and 10 mg. morphine but 15 mg. dezocine produced consistently better analgesia than 10 mg. morphine. This superiority of 15 mg. dezocine was statistically significant on the pain analogue scale at 1 to 4 hours. More morphine-treated than dezocine-treated patients withdrew from each study because of inadequate pain relief. The frequency of adverse effects was not significantly different between groups in either study and none of the patients had clinically significant changes in vital signs. These results indicate that dezocine is a safe and effective analgesic for the treatment of renal and ureteral colic due to calculi, and 15 mg. dezocine were more effective than 10 mg. morphine in this pain model.

Acute Disease↗

N-Cycloalkanoyl-L-phenylalanine derivatives as VCAM/VLA-4 antagonists.

A systematic structure-activity relationship investigation of the lead compound 1 resulted the identification of several N-[(substituted alkyl)cycloalkanoyl]-4-[((2,6-dichlorophenyl)carbonyl)amino]-L-phenylalanine derivatives as potent VCAM/VLA-4 antagonists. The data are consistent with a model of these compounds in which these alkanoylphenylalanines reside in a compact gauche (-) bioactive conformation.

Crystallography, X-Ray↗

Theoretical calculation of the vibrational spectra of cis-cis-cyclooctadienes in the vapour phase.

The theoretical infrared spectra of 1,3-cis-cis-cyclooctadiene (1,3-COD) and 1,5-cis-cis-cyclooctadiene (1,5-COD), were obtained by ab initio MO calculations at Hartree-Fock level. The results were compared with the available IR experimental spectra of 1,3- and 1,5-COD. The apparent agreement between theoretical and experimental data allows us to exploit two bands, found only in the case of the theoretical spectrum of 1,4-COD, as a tool for identifying 1,4-COD during its synthesis.

Cyclooctanes↗

Maduropeptin: an antitumor chromoprotein with selective protease activity and DNA cleaving properties.

Maduropeptin (MDP) is a recently isolated antitumor antibiotic, consisting of an enediyne-containing chromophore embedded in a highly acidic protein. This holoantibiotic damages duplex DNA in vitro, producing a mixture of single- and double-strand breaks at selected sites. The chromophore, isolated as the methanol adduct from the protein-containing holoantibiotic, exhibits the same selectivity and cleavage chemistry as the chromoprotein complex. Preliminary evidence suggests that the primary DNA breaks involve 4'-H abstraction from the deoxyribose sugars at the cleavage sites. Unlike most other enediyne antitumor antibiotics, DNA strand scission is not bioreductively induced by MDP or the methanol adduct of the chromophore. This was also observed for the C1027 chromophore. DNA cleavage is inhibited in the presence of certain cations (Ca2+, Mg2+) as was observed with the kedarcidin chromophore. 1H NMR spectroscopy studies on the methanol adduct of the maduropeptin chromophore in the presence of calcium chloride provide clues regarding its activation and give insight as to the regions of the chromophore important for DNA binding. Our results suggest that the solvent artifact of the chromophore may in essence be a prodrug and it regenerates the parent chromophore as in the holoantibiotic prior to cleaving DNA. As with kedarcidin and neocarzinostatin, maduropeptin exhibits a high affinity for histones, in vitro, cleaving them to low molecular mass peptides. Histone H1, the most opposite in net charge, is cleaved most readily. This latter activity may serve to disrupt the chromatin superstructure in vivo, prior to exposing the DNA to the chromophore.

Alkynes↗

C1027 chromophore, a potent new enediyne antitumor antibiotic, induces sequence-specific double-strand DNA cleavage.

C1027, a new macromolecular antitumor antibiotic produced by a Streptomyces strain, shows highly potent cytotoxicity to cultured cancer cells and marked DNA cleaving ability. The structure of its chromophore, responsible for most of the biological activities of the antibiotic, was recently determined and found to contain a nine-membered enediyne. In contrast to other enediyne antibiotics, such as neocarzinostatin, calicheamicin, esperamicin, and recently found kedarcidin, C1027 damages duplex DNA even in the absence of thiols. The DNA damage caused by C1027 includes double-strand breaks, single-strand breaks, and abasic sites. Experiments with plasmid DNA and 32P-end-labeled restriction fragments demonstrated that the chromophore, extracted from the protein-containing holoantibiotic, interacts in the DNA minor groove and cleaves double-helical DNA with a remarkable sequence-selectivity causing direct double-strand breaks. The double-strand cleavage sites, occurring predominantly at CTTTT/AAAAG, ATAAT/ATTAT, CTTTA/TAAAG, CTCTT/AAGAG, and especially GTTAT/ATAAC, consist of five nucleotide sequences with a two-nucleotide 3'-stagger of the cleaved residues (cutting sites are underlined). The chemical structures of the damaged residues at the GTTAT/ATAAC cleavage site suggest a model in which a C1027-induced double-strand break results from abstraction, by a single molecule of the diradical form of the chromophore, of a C4' hydrogen atom from the A residue of GTTAT and a C5' hydrogen atom from the A of ATAAC on the opposite strand. Single-strand breaks, which are mainly produced at adenylate and thymidylate residues, appear to be separate events presumably resulting from different binding modes of the drug to DNA.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkynes↗