High frequency of dolutegravir resistance in patients failing a raltegravir-containing salvage regimen

OBJECTIVES: Dolutegravir is a second-generation integrase strand transfer inhibitor (InSTI) that has been recently approved by the FDA to treat antiretroviral therapy-naive as well as treatment-experienced HIV-infected individuals, including those already exposed to the first-generation InSTI. Despite having a different mutational profile, some cross-resistance mutations may influence its susceptibility. The aim of this study was to evaluate the impact of a raltegravir-containing salvage regimen on dolutegravir activity. PATIENTS AND METHODS: Blood samples of 92 HIV-infected individuals with virological failure (two or more viral loads >50 copies/mL after 6 months of treatment) using raltegravir with optimized background therapy were sequenced and evaluated according to the Stanford University HIV Drug Resistance Database algorithm. RESULTS: Among the 92 patients analysed, 32 (35%) showed resistance to dolutegravir, in most cases associated with the combination of Q148H/R/K with G140S/A mutations. At genotyping, patients with resistance to dolutegravir had viral load values closer to the highest previously documented viral load. CONCLUSIONS: Changes in viraemia during virological failure may indicate the evolution of raltegravir resistance and may predict the emergence of secondary mutations that are associated with a decrease in dolutegravir susceptibility. Early discontinuation of raltegravir from failing regimens might favour subsequent salvage with dolutegravir, but further studies are necessary to evaluate this issue.

Effect of Endogenous Bone Marrow Derived Stem Cells Induced by AMD-3100 on Expanded Ischemic Flap

The purpose of this study was to devise an expanded ischemic flap model and to investigate the role of AMD-3100 (Plerixafor, chemokine receptor 4 inhibitor) in this model by confirming its effect on mobilization of stem cells from the bone marrow. Male Sprague-Dawley rats were used as an animal research model. The mobilization of stem cells from the bone marrow was confirmed in the AMD-3100-treated group. The fractions of endothelial progenitor cells (EPC) and the vascular endothelial growth factor receptor (VEGFR) 2+ cells in the peripheral blood were increased in groups treated with AMD-3100. The expression of vascular endothelial growth factor (VEGF) was increased in response to expansion or AMD injection. The expression of stromal cell derived factor (SDF)-1 and VEGFR2 were increased only in unexpanded flap treated with AMD-3100. Treatment with AMD-3100 increased both the number and area of blood vessels. However, there were no statistically significant differences in the survival area or physiologic microcirculation in rats from the other groups. This endogenous neovascularization induced by AMD-3100 may be a result of the increase in both the area and number of vessels, as well as paracrine augmentation of the expression of VEGF and EPCs. However, the presence of a tissue expander under the flap could block the neovascularization between the flap and the recipient regardless of AMD-3100 treatment and expansion.

Inhibitory effect of CXC chemokine receptor 4 antagonist AMD3100 on bleomycin induced murine pulmonary fibrosis

CXC chemokine receptor 4 (CXCR4), which binds the stromal cell-derived factor-1 (SDF-1), has been shown to play a critical role in mobilizing the bone marrow (BM)-derived stem cells and inflammatory cells. We studied the effects of AMD3100, CXCR4 antagonist, on a murine bleomycin-induced pulmonary fibrosis model. Treatment of mice with AMD3100 in bleomycin-treated mice resulted in the decrease of SDF-1 in bronchoalveolar lavage (BAL) fluids at an early stage and was followed by the decrease of fibrocytes in the lung. AMD3100 treatment decreased the SDF-1 mRNA expression, fibrocyte numbers in the lung at an early stage (day 3) and CXCR4 expression at the later stage (day 7 and 21) after bleomycin injury. The collagen content and pulmonary fibrosis were significantly attenuated by AMD3100 treatment in later stage of bleomycin injury. AMD3100 treatment also decreased the murine mesenchymal and hematopoietic stem cell chemotaxis when either in the stimulation with bleomycin treated lung lysates or SDF-1 in vitro. In BM stem cell experiments, the phosphorylation of p38 MAPK which was induced by SDF-1 was significantly blocked by addition of AMD3100. Our data suggest that AMD3100 might be effective in preventing the pulmonary fibrosis by inhibiting the fibrocyte mobilization to the injured lung via blocking the SDF-1/CXCR4 axis.

Chemical modification studies of Rhizomucor miehei protease: evidence for the role of basic amino acids in enzyme catalysis.

The effect of chemical modification on milk clotting and proteolytic activities of aspartyl protease obtained from Rhizomucor miehei NRRL 3500 was examined in the absence and the presence of its specific inhibitor pepstatin A. The effect on the ratio of milk clotting activity (MC) to proteolytic activity (PA), an index of the quality of milk clotting proteases was also determined. Modification of the enzyme with trinitrobenzenesulfonic acid, diethylpyrocarbonate and phenylglyoxal produced an increase in the ratio of MC/PA, while modification with 2- hydroxy-5-nitrobenzyl bromide did not affect the ratio. Modification with N-acetylimidazole resulted in a marginal increase in MC/PA ratio. Protection using pepstatin A during modification with phenylglyoxal, N-acetylimidazole and 2-hydroxy-5-nitrobenzyl bromide, protected both MC and PA. In the case of modification by diethylpyrocarbonate, pepstatin A protected only MC. Pepstatin A did not protect both the activities on the modification of the enzyme by trinitrobenzene sulfonic acid. These observations indicate the presence of arginine, tyrosine and tryptophan at the catalytic site of the enzyme, for eliciting MC and PA of the enzyme. In general, modification of the positively charged residues increases the MC/PA ratio of the enzyme. In addition the modified lysine residues responsible for the inactivation of the enzyme were not involved in the active site of the enzyme. Thus the lysine residues might have a secondary role in enzyme catalysis. Further, histidine at the catalytic site was found to be exclusively involved in milk clotting activity. The enzyme with modified histidine residues were more susceptible to autocatalysis, indicating that histidine residues protect the enzyme against autolysis.

Hidrolise do terconazol: relacao estrutura-atividade / Hydrolysis of terconazole: chemical structure - biological activity relationship

Com o objetivo de contribuir para melhor entendimento da relacao entre estrutura quimica e a atividade biologica do terconazol, foi proposta a otimizacao da sua hidrolise. O isolamento e identificacao de produto resultante, cujas analises levam a crer que se trata da 1-(2,4-diclorofenil)-2-(1H-1,2-4-triazol-1-il)etanona (DFTE), sugerem que o terconazol sofre hidrolise no anel 1,3-dioxolanico (cetal ciclico), resultando em composto carbonilico. A DFTE mostrou-se ativa contra Candida albicans CBS 3156 e Escherichia coli ATCC 25922, nao apresentando atividade contra Staphylococcus aureus ATCC 25923. Estes resultados confirmam dados sobre o mecanismo de acao do terconazol e de outros compostos azolicos, tanto contra fungos e leveduras como contra bacterias

The influence of gastrokinetics and inhibitors of acid secretion on motor responses of the gastric fundus to acetylcholine

The influence of eight gastrokinetics and six inhibitors of acid secretion used routinely in gastrointestinal prescriptions were verified, through dose-response curves to acetylcholine, on longitudinal muscular gastric fundus secretions of 70 rats. Some drugs increased the fundic motor response, and few others decreased the affinity of the fundi for acetylcholine. The results of the present paper may contribute to the knowledge of the effect of these drugs on gastric motility

Substituted nitrogen bridgehead heterocycles of potential smooth muscle relaxant and antihypertensive activities

Pyrrolo [1,2-c] pyrimidine derivatives I reacted with various acid chlorides to afford a number of 3-substituted pyrimido [5,4-e] pyrrolo [1,2-c] pyrimidines. The 3-chlorocarbonyl intermediate I-A reacted with different alcohols to give the corresponding esters. Moreover, 3-chloromethyl derivative I-B reacted with thiourea, alkoxides and sodium salts of aromatic acids to yield thiouronium salts, ethers and esters, respectively. Some members were tested as smooth muscle relaxant diuretic and hypotensive activities. It was shown that compound VII-a is the potent as hypotensive and diuretic agent. Also, it was noticed that, while all the test substances inhibit the uterine motility, VII-a stimulates the uterine motility in all stages

Synthesis of some novel heterocyclic compounds of potential antiallergic activity

Dicyanomethylidene 1a and its piperidine analogue 1b reacted with B-chloroethylisocyanate to afford unexpectedly the heterocycles: imidazo [1,2-c] pyrrolo [2,1-f] pryrimidine-10-carbonitrile and imidazo [1,2-c] pyrido [2,1-f] pyrimidine-11-carbonitrile hydrochlorides 3a and 3b respectively. Subsequent hydrolysis gave the corresponding carboxamides 4a,b and carboxylic acids 6a,b. The structures of the new nuclei have been confirmed by chemical and spectral means. Two compounds were subjected to pharmacological testing and have shown 50% inhibition of the histamine induced contraction of guinea pig ileum

Studies on the synthesis and biological activity of certain spiro heterocyclic compounds

A series of some spiro compounds covering thiazolidinones, beta- lactams and triazolidine incorporating piperidino [2, 3-g] 1,2,3,4,6,7,8,9-octahydro-quinolinoqinone [3a-c, 4a-c and 5a-c] were prepared. The synthesis was proceeded through cycloaddition reaction of thioglycolic acid, monochloroacetyl chloride and diazomethane to the newly reported bis aryl [naphthyl] iminopiperidino [2,3-9]-1,2,3,4,6,7,8,9,-octahydro-quinolinoquinone [1a-c]. The biological screening of some selected spiro compounds was tested against some bacterial and fungal strains

Exploration of antileishmanial activity in heterocycles; results of their in vivo & in vitro bioevaluations.

A total of 51 imidazoles, pyrroles, quinolines and isoxazolines compounds were screened for antileishmanial activity in vivo and in vitro, using Leishmania donovani as the test parasite. The screening revealed hitherto unknown antileishmanial activity in these heterocycles. Three of the compounds screened (one belonging to isoxazoline series and two from pyrrole series) showed significant anti-leishmanial activity, ranging from 86-91 per cent inhibition in hamsters. When tested in vitro, using macrophage amastigote culture system, these compounds showed inhibition of 62-78 per cent at 30 micrograms/ml concentration.