Antiretroviral Therapy for Prevention Is a Combination Strategy

In the past several years, the debate of “treatment vs prevention” has shifted with the introduction of the concept of “treatment as prevention,” (TasP), stemming from a series of compelling observational, ecological, and modeling studies as well as HPTN 052, a randomized clinical trial, demonstrating that use of ART is associated with a decrease in HIV transmission. In addition to TasP being viewed as 1 intervention in a combination strategy for HIV Prevention, TasP is, in and of itself, a combination of multiple interventions that need to be implemented with high coverage in order to achieve its potential impact.     

Pyridazine and its related compounds. Part 34. Hypoglycemic and hypolipidemic activity of some novel condensed pyridazine sulfonamides

A novel class of sulfonylurea and thiourea derivatives substituted with pyridazine and triazolopyridazine were designed and synthesized. The target compounds were assayed for their effects on the insulin release of alloxan-induced diabetic rats. The results showed that derivatives 4a, 4c, 8a, 11a, and 11b have significant antihyperglycemic effect in an experimental model of diabetes mellitus. No significant differences in cholesterol levels were observed between the diabetic group and diabetic groups that received the test compounds. However, the triglycerides level was reduced significantly by compound 8a when compared with the diabetic group.     

The Flavonoid Constitunts of Leucaena Leucocephala. Growing in Egypt,and Their Biological Activity

Background

Leucaena leucocephala is native to Southern Mexico and Northern Central America, but is now naturalized throughout the tropics. The phyto-chemical data of L. leucocephala revealed the presence of terpenes, flavonoids, coumarins and sterols. Various parts of L. leucocephala have been reported to have medicinal properties.

Materials and Methods

Flavonoids were isolated from the aerial parts of L. leucocephala. Antioxidant activity of the extracts and the isolated compounds was evaluated using (DPPH), as well as their cytotoxic activity using a single tumor [Ehrlish ascites carcinoma cells].

Results

The flavonoidal constituents isolated from chloroform, ethyl acetate and n-butanol fractions of the aqueous alcoholic extract of aerial parts of Leucaena leucocephala were identified as Caffeic acid, Isorhamnetin, Chrysoeriol, Isorhamnetin 3-O-galactoside, Kaempferol-3-O-rubinoside, Quercetin-3-O-rhamnoside and Luteolin-7-glucoside. Chemical structures of the isolated compounds were identified by TLC, PC and spectral techniques (UV, ¹H-NMR and MS). The ethyl acetate fraction and the isolated flavonoidal compounds showed high antioxidant activity compared to Trolox (standard antioxidant compound). The different fractions and isolated compounds of Leucaena leucocephala exhibited no cytotoxic activity against Ehrlich-ascitis carcinoma cell line at the tested concentrations.

Conclusion

This is the first record of the flavonoids in the aerial parts of Leucaena leucocephala (L.) except Quercetin-3-O-rhamnoside.     

Nanobiotic formulations as promising advances for combating MRSA resistance: susceptibilities and post-antibiotic effects of clindamycin,doxycycline, and linezolid

Antimicrobial activity and post-antibiotic effects (PAEs) are both important parameters in determination of the dosage regimen of antimicrobial agents. In the present study, antimicrobial activity and PAEs of clindamycin, doxycycline, linezolid, and their nanobiotic formulations were evaluated against two methicillin resistant Staphylococcus aureus clinical isolates (MRSA) encoded (MRSA-S1 and MRSA-S2). Nanobiotic formulations increased the susceptibility of MRSA isolates by 4–64 folds as compared to their conventional ones. The PAE values were determined after exposure of MRSA isolates for 1 h to 10× the MICs of the tested antibiotics. The duration of PAEs were recorded after bacterial growth in Mueller Hinton broth (MHB) free from antibiotic has been restored. The PAE values for MRSA-S1 were 2.5 h for the conventional antibiotics. However, the PAEs for nanobiotics were 4 h for both clindamycin and linezolid, while 3 h for doxycycline. For MRSA-S2, linezolid and linezolid nanobiotics PAEs were 3 h. PAEs of clindamycin and clindamycin nanobiotics were 3.75 h and 4 h, respectively. Doxycycline and doxycycline nanobiotics revealed the same PAEs patterns of 3.5 h. The findings of the current study may positively influence the pharmacodynamics of the antibiotics and consequently the dosage regimen of nanobiotics as well as on their clinical outcome.

Novel nanobiotic formulations of clindamycin, doxycycline, and linezolid were evaluated for the post-antibiotic effects against biofilm forming methicillin resistant Staphylococcus aureus (MRSA).