Experimental Evaluation of the Hypersensitivity Reactions of a New Glycopeptide Antibiotic Flavancin in Animal Models.

Glycopeptide antibiotics are still in demand in clinical practice for treating infections caused by resistant gram-positive pathogens; however, their use is limited due to severe adverse reactions. Their predominant types of side effects are immunoglobulin E-mediated or nonmediated hypersensitivity reactions. Therefore, the development of new glycopeptide antibiotics with improved toxicity profiles remains an important objective in advancing modern antimicrobial agents.

Semisynthetic Amides of Polyene Antibiotic Natamycin.

Natamycin is a macrolide polyene antibiotic, characterized by a potent broad spectrum antifungal activity and low toxicity. However, it is not used for the treatment of systemic mycoses due to its low bioavailability and low solubility in aqueous solutions. In order to create new semisynthetic antifungal agents for treatment of mycoses, a series of water-soluble amides of natamycin were synthesized.

Evaluation of Toxic Properties of New Glycopeptide Flavancin on Rats.

Glycopeptide antibiotics have side effects that limit their clinical use. In view of this, the development of glycopeptides with improved chemotherapeutic properties remains the main direction in the search for new antibacterial drugs. The objective of this study was to evaluate the toxicological characteristics of new semi-synthetic glycopeptide flavancin.

Subchronic Toxicity Study of Oral Anthrafuran on Rabbits.

A new antitumor multi-target drug anthrafuran, with cellular targets such as topoisomerase I/II and some protein kinases, was obtained in Gause Institute of New Antibiotics and was demonstrated to have a reliable specific effect on different murine and human tumor models by oral administration. In this study, we focused on the evaluation of subchronic toxicity of oral anthrafuran drug formulation (AF) on Chinchilla rabbits. The absence of any changes in the condition or behavior of animals was shown for oral anthrafuran.

Aminoalkylamides of Eremomycin Exhibit an Improved Antibacterial Activity.

After decades, the glycopeptide vancomycin is still the preferred antibiotic against resistant strains of Gram-positive bacteria. Although its clinical use is strictly regulated, the gradual spread of vancomycin-resistant bacteria, such as glycopeptide-resistant and glycopeptide-intermediate and vancomycin-resistant spp., is a serious health problem.

Discovery of Amphamide, a Drug Candidate for the Second Generation of Polyene Antibiotics.

Amphotericin B (AmB, ) is the drug of choice for treating the most serious systemic fungal or protozoan infections. Nevertheless, its application is limited by low solubility in aqueous media and serious side effects such as infusion-related reactions, hemolytic toxicity, and nephrotoxicity. Owing to these limitations, it is essential to search for the polyene derivatives with better chemotherapeutic properties.

Experimental Evaluation of Anticancer Efficiency and Acute Toxicity of Anthrafuran for Oral Administration.

The new antitumor agent anthrafuran has demonstrated a consistent effect in murine tumor models when administered parenterally due to the simultaneous inhibition of multiple cellular targets such as topoisomerases I/II and protein kinases. In this study, we assessed the anticancer efficiency and acute toxicity of anthrafuran administered orally. The action of anthrafuran was studied on transplanted tumor models which included P388 leukemia, Ca755 mammary adenocarcinoma, LLC lung carcinoma, and T47D human breast cancer xenografts on Balb/c nude mice.

[Chest X-ray in patients with fever and no localizing symptoms?].

Fever without localizing symptoms is a clinical problem that is frequently encountered on the emergency department. According to the NICE sepsis guideline, a chest X-ray should be considered in such patients. However, the evidence supporting this recommendation is limited to patients with neutropenic fever.

Toxicological study of doxorubicin-loaded PLGA nanoparticles for the treatment of glioblastoma.

Doxorubicin loaded in poloxamer 188-coated PLGA nanoparticles (Dox-NP + P188) was shown to produce a high antitumor effect against the experimental orthotopic 101.8 glioblastoma in rats upon intravenous administration. The objective of the present study was to evaluate the acute and chronic toxicity of this nanoformulation.

Eremomycin pyrrolidide: a novel semisynthetic glycopeptide with improved chemotherapeutic properties.

Purpose: Development of new semisynthetic glycopeptides with improved antibacterial efficacy and reduced pseudoallergic reactions.

Methods: Semisynthetic glycopeptides 3-6 were synthesized from vancomycin (1) or eremomycin (2) by the condensation with pyrrolidine or piperidine. The minimum inhibitory concentration (MIC) for the new derivatives was measured by the broth micro-dilution method on a panel of clinical isolates of Staphylococcus and Enterococcus.

[Toxicological Evaluation of Intravenous Formulation of Rifapentine.].

Rifapentine belongs to the most potent antituberculosis drugs. Nevertheless, there are some limitations for its clinical use because of the low aqueous solubility and side effects. A technological approach to development of rifapentine intravenous formulation based on human serum albumin was described earlier and its efficacy against experimental tuberculosis was estimated.

Cognitive functions and neuropsychological status of medical students with different attitudes to alcohol use: a study conducted at the Belarusian State Medical University, Minsk, Belarus.

This article presents findings on the effects of alcohol use on cognitive performance, functional (well-being, activity, mood) and neuropsychological status and anxiety levels of medical students. A total of 265 medical students (107 males and 158 females) from the Belarusian State Medical University, Minsk (Belarus) were administered questionnaire, containing the AUDIT, CAGE, MAST, and PAS, and other alcohol related questions. Academic Performance questionnaire was administered together with other tests.

Structure-antifungal activity relationships of polyene antibiotics of the amphotericin B group.

A comprehensive comparative analysis of the structure-antifungal activity relationships for the series of biosynthetically engineered nystatin analogues and their novel semisynthetic derivatives, as well as amphotericin B (AMB) and its semisynthetic derivatives, was performed. The data obtained revealed the significant influence of the structure of the C-7 to C-10 polyol region on the antifungal activity of these polyene antibiotics. Comparison of positions of hydroxyl groups in the antibiotics and in vitro antifungal activity data showed that the most active are the compounds in which hydroxyl groups are in positions C-8 and C-9 or positions C-7 and C-10.

Synthesis and study of the antifungal activity of new mono- and disubstituted derivatives of a genetically engineered polyene antibiotic 28,29-didehydronystatin A1 (S44HP).

Mono- and disubstituted novel derivatives of the heptaene nystatin analog 28,29-didehydronystatin A(1) (S44HP, 1) were obtained by chemical modification of the exocyclic C-16 carboxyl and/or an amino group of mycosamine moiety. The strategy of preparation of mono- and double-modified polyene macrolides was based on the use of intermediate hydrophobic N-Fmoc (9-fluorenylmethoxycarbonyl) derivatives that facilitated the procedures of isolation and purification of new compounds. The antifungal activity of the new derivatives was first tested in vitro against yeasts and filamentous fungi, allowing the selection of the most active compounds that were subsequently tested for acute toxicity in mice.

Intravenous tolerance of a nanoparticle-based formulation of doxorubicin in healthy rats.

A comparative toxicological study of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles coated with polysorbate 80 was performed in male and female Wistar rats. The drug substance was used as a reference formulation. The formulations were injected intravenously at a therapeutic dose of 6 mg/kg administered either as a single injection or in form of four weekly injections.

Influence of the formulation on the tolerance profile of nanoparticle-bound doxorubicin in healthy rats: focus on cardio- and testicular toxicity.

A toxicological study of doxorubicin bound to poly(butyl cyanoacrylate) or human serum albumin nanoparticles coated with polysorbate 80 was performed in healthy rats. The doxorubicin formulations were injected at a therapeutic dose regimen (3 x 1.5 mg/kg with a 72 h interval), and the animals were followed up for 15 or 30 days.

[Fortification of antimicrobial barrier of the small intestine in newborn mice after oral administration of ascorbigen].

Ascorbigen, a natural product, is an indole derivative of L-ascorbic acid. Its effect on postnatal development and antibacterial resistance of the small intestine was studied on newborn mice. Ascorbigen was administered to 3-5-day old mice in a dose of 100 mg/kg orally every day for 7-10 days.

[Comparative analysis of in vitro antifungal activity and in vivo acute toxicity of the nystatin analogue S44HP produced via genetic engineering].

New polyene macrolide S44HP was purified from the culture of recombinant Streptomyces noursei strain with engineered nystatin polyketide synthase. S44HP, nystatin (NYS), and amphotericin B (Amph-B) were tested against 19 clinical fungal isolates in agar diffusion assay, which demonstrated clear differences in antifungal activities of these antibiotics. Sodium deoxycholate suspensions of all three antibiotics were subjected to acute toxicity studies in vivo upon intravenous administration in mice.

Potential mutagenicity, embryotoxicity, and teratogenicity of calcium ketopantoyl aminobutyrate.

We studied mutagenic, embryotoxic, and teratogenic properties of calcium ketopantoyl aminobutyrate, a preparation proposed as a new drug. Long-term oral administration of calcium ketopantoyl aminobutyrate produced no mutagenic, embryotoxic, and teratogenic effects.

Allergic and immunotoxic effects of calcium ketopantoyl aminobutyrate.

We studied the allergic and immunotoxic effects of a new promising medicinal preparation calcium ketopantoyl aminobutyrate. Calcium ketopantoyl aminobutyrate produced no negative effects on general mechanisms of humoral and cellular immunity. This preparation did not modulate the anaphylactic reaction to bovine serum, exhibited no mitostatic and lymphotoxic properties, had no effect on the delayed-type hypersensitivity response, and did not produce active cutaneous anaphylactic reaction.

Effect of a novel antineoplastic drug olipifat on antitumor immunity in mice.

Olipifat is an antineoplastic drug containing pyrophosphate and a product of special lignin processing. Donor C57Bl/6J mice with syngeneic B16 melanoma received a single 5-day course of olipifat. Effect of olipifat on antitumor resistance was evaluated by local neutralization test [3].

Histamine-correcting drug pherofunginum and bone tissue regeneration.

It has been shown that a histamine-correcting preparation (Pherofunginum) speeds up bone tissue regeneration. Other histamine correcting preparations behave in a similar way. We conclude that the application of these preparations in traumatology may have beneficial results.