An update on the pharmacotherapeutic management of lower respiratory tract infections

Application of Next-Generation Sequencing in Infections After Allogeneic Haematopoietic Stem Cell Transplantation: A Retrospective Study

This retrospective study aimed to determine the characteristics of infection and diagnostic efficacy of next-generation sequencing (NGS) in patients with fever after allogeneic hematopoietic stem cell transplantation (allo-HSCT). A total of 71 patients with fever after HSCT were enrolled in this study. Compared with conventional microbiological test (CMT), we found that the sensitivity of NGS versus CMT in peripheral blood samples was 91.2% vs. 41.2%, and that NGS required significantly less time to identify the pathogens in both monomicrobial infections (P=0.0185) and polymicrobial infections (P= 0.0027). The diagnostic performance of NGS was not affected by immunosuppressant use. Viruses are the most common pathogens associated with infections. These results indicated that the sensitivity, timeliness, and clinical significance of NGS are superior for the detection of infections. Although NGS has the advantage of identifying a wide range of potential pathogens, the positive rate is related closely to the sample type. Therefore, we recommend that, in the clinical application of NGS to detect pathogens in patients after allo-HSCT, an appropriate sample type and time should be selected and submitted to improve the positive rate and accuracy of NGS. NGS holds promise as a powerful technology for the diagnosis of fever after HSCT.

Synthesis and biological activity of 2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide derivatives

The synthesis and antimicrobial evaluation of new 2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide derivatives was investigated. According to the literature, there are a lot of antimicrobial agents among the pyrimidines and hydrazides, and therefore it seems promising to use 2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide as a base object for synthesizing new biologically active substances. 2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide was obtained by the hydrazinolysis of ethyl thioacetate, using a 3-fold molar excess of 85 % hydrazine hydrate in ethanol, at room temperature. Interaction of 2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide with ketones during boiling in ethanol yielded N-ylidenehydrazides. The solid obtained by concentration was collected, and then purified by recrystallization. The new compounds were characterized by ¹H, ¹³C NMR, IR spectroscopy and elemental analysis. The antibacterial and antifungal activities of the new compounds were analysed using agar diffusion and tenfold broth (pH 7.2 - 7.4) dilution methods, in comparison with the clinical used drugs, ceftriaxone and Pimafucin. The structure-activity studies showed that, depending on the nature of the hydrazide fragment, the newly synthesized compounds exhibited varying degrees of microbial inhibition. Within the same series the antimicrobial activity depends on the nature of the substituent attached to the benzene ring. The investigation of antibacterial screening data revealed that the compounds N'-[1-(4-aminophenyl)ethylidene]-2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide, N'-[1-(4-hydroxyphenyl)ethylidene]-2-[6-methyl-4-(thietan-3-yloxy)pyrimidin-2-ylthio]acetohydrazide, N'-[1- (2,5-dihydroxyphenyl) ethylidene]-2-[6-methyl-4-(thietan-3-yloxy)-pyrimidin-2-ylthio]acetohydrazide were found to be more potent than the other synthesized analogues.

Biomarkers in Chronic Obstructive Pulmonary Disease: Emerging Roles of Eosinophils and Procalcitonin

Antibiotics can improve the prognosis in patients with exacerbation of chronic obstructive pulmonary disease. However, the overuse of antibiotics can carry serious adverse effects for patients (gastrointestinal infections) and for society (bacterial resistance). Likewise, systemic corticosteroids may also help these patients, but also carries severe adverse effects like osteoporosis, muscle loss, and diabetes, in many patients. Whenever safe methods exist to reduce these two treatment modalities, they should be implemented. The blood biomarkers procalcitonin and the fraction of leukocytes known as eosinophil granulocytes have been proven in randomized controlled trials (RCTs), to effectively, significantly, and substantially assist in reducing the use of these two potent, yet toxic medication types. In this review, the background and main clinical results are discussed, explaining the rationale for biomarker-guided clinical decisions. Also, the main expected effects, their sizes, and importantly the limitations to such a strategy are described. Clinical evidence is prioritized with main weight on RCTs and meta-analyses of these and regarding outcomes, and focus is set on the safety of such a biomarker-guided strategy, as well as the effects on medicine reduction. In an epoch of increasing demands to physicians from patients and politicians to cure and reduce symptoms, the Hippocratic phrase of "primum non nocere" or "first, do no harm" seems more than ever of contemporary importance.

Experimental study of the influence of a neogalenical phytocomplex from the shoots of Ledum palustre on the course of acute bronchitis disease in rats

The aim of the experiment was to study the anti-inflammatory effect of the novogalene agent Ledum 50, obtained from Ledum palustre shoots, in a rat model of acute bronchitis. Materials and methods. Acute bronchitis was initiated by endotracheal administration of 1 % formalin solution. The effectiveness of Ledum 50 was investigated by the number of leukocytes and cell composition in isotonic BAL solution after 24 hours and after 8 days of the experiment. Serum levels of C-reactive protein (CRP), alkaline phosphatase (AP) and CIC were determined. Histological examination of the lungs was carried out. Results. Endotracheal injection of formalin caused irritation of the trachea and bronchi, excessive formation of bronchial secretions (heavy breathing, wheezing) in all the studied groups. The lethality of animals in the OB group on the 3rd day of the experiment (1 rat) was recorded, in the studied groups there was no death. The level of leukocytes in BAL after 24 hours exceeded the index of the IC group by 9.63 times (p<0.05), after 8 days – by 3.0 times (p<0.05). In the cellular composition of BAL, there was a significant increase in granulocytes (rod- ​​and segmented neutrophils, eosinophils), monocytes and a decrease in the lymphocyte population against the IC group. Such changes were verified in the long term (8 days of the experiment), which indicates an inflammatory process. In the group of rats that received Ledum 50, leukocytes in the BAL significantly decreased, the number of monocytes and lymphocytes in the BAL decreased, the amount of CIC in the blood serum, CRP and AP normalized. In terms of effectiveness, Ledum 50 significantly exceeded the BAL values ​​of the reference drug. The effectiveness of experimental therapy for acute bronchitis was also verified by studying the histostructure of the airways and the respiratory part of the lungs. Conclusions. Studies confirm the favorable course of acute bronchitis with Ledum 50 monotherapy. This fact is confirmed by the results of normalization of hematological parameters, leukocytes and BAL cell composition after 7 days of treatment with the claimed agent. This is the basis for further preclinical and clinical studies with the aim of creating an oral drug for the treatment of acute bronchitis.

Granulocyte-targeted therapies for airway diseases

The average respiration rate for an adult is 12-20 breaths per minute, which constantly exposes the lungs to allergens and harmful particles. As a result, respiratory diseases, which includes asthma, chronic obstructive pulmonary disease (COPD) and acute lower respiratory tract infections (LTRI), are a major cause of death worldwide. Although asthma, COPD and LTRI are distinctly different diseases with separate mechanisms of disease progression, they do share a common feature - airway inflammation with intense recruitment and activation of granulocytes and mast cells. Neutrophils, eosinophils, basophils, and mast cells are crucial players in host defense against pathogens and maintenance of lung homeostasis. Upon contact with harmful particles, part of the pulmonary defense mechanism is to recruit these cells into the airways. Despite their protective nature, overactivation or accumulation of granulocytes and mast cells in the lungs results in unwanted chronic airway inflammation and damage. As such, understanding the bright and the dark side of these leukocytes in lung physiology paves the way for the development of therapies targeting this important mechanism of disease. Here we discuss the role of granulocytes in respiratory diseases and summarize therapeutic strategies focused on granulocyte recruitment and activation in the lungs.

Diagnostic value and clinical application of next-generation sequencing for infections in immunosuppressed patients with corticosteroid therapy

Background

Next-generation sequencing (NGS) is a comprehensive approach for sequence-based identification of pathogens. However, reports on the use of NGS in patients with immunosuppression are scarce, especially in subjects with negative microbiological results.

Methods

In this study, NGS was performed on samples obtained from 108 anonymized patients with suspected infection undergoing immunosuppressive corticosteroid therapy. A panel of conventional microbiological tests (CMT) was performed in parallel with NGS.

Results

Of these 108 subjects, 36 were diagnosed with infections by clinical and microbiological criteria (Group I), 41 were exclusively diagnosed clinically (Group II), and 31 exhibited no evidence of infection (Group III). In Group I, NGS was concordant with CMT results from 29 patients (80.6%). A total of 4 samples had positive NGS results in Group III. NGS showed a sensitivity of 80.6% (95% CI, 64.7% to 90.6%) and specificity of 87.1% (95% CI, 70.5% to 95.5%). NGS also played an important role in optimizing antibiotic regimens in patients with negative results for CMT (Group II). The treatment success rate (TSR) of patients using NGS-guided antibiotic regimens (81.8%, 18/22) was significantly higher than that of patients using empirical antibiotics (52.6%, 10/19) (P<0.0001). NGS results were not affected by the degree of immunosuppression.

Conclusions

NGS of clinical samples from immunosuppressed patients demonstrated promising diagnostic potential in identifying clinically relevant pathogens. Consequently NGS stands to become a standard tool for infection detection and control, providing valuable information to optimize antibiotic therapy in immunosuppressed patients.