Correlations between soluble ST2 concentration and the nutritional status in patients with heart failure with reduced ejection fraction - cross-sectional study.

BACKGROUND: Heart failure (HF) is a global problem that stimulates research on markers associated with the diagnosis and course of the disease. Soluble suppression of tumorigenicity-2 (sST2) is a receptor for interleukin-33 and is associated with increased mortality rates in HF patients. Malnutrition in HF is also connected with inflammation and is associated with worse prognosis. The present study aimed to evaluate the relationship between sST2 concentration and the nutritional status of patients with HF with reduced ejection fraction (HFrEF). MATERIAL AND METHODS: 138 patients with HFrEF were enrolled in this cross-sectional study. Nutritional status was assessed using Geriatric Nutritional Risk Index (GNRI) and Controlling Nutritional Status (CONUT). The mean age was 53.6 ± 10.8 years. RESULTS: In the group with sST2 > 32.9 ng/mL, the GNRI score was higher and the associated risk of malnutrition was more common (29% vs. 12%; p = 0.011). Coherently in the group with sST2 > 32.9 ng/mL the median CONUT score was worse (2 [IQR 1-3] vs. 1 [IQR 0-2]; p = 0.0016) and the risk of malnutrition defined by this tool was also more prevalent (p = 0.0079). This relationship was independent of the concentration of natriuretic peptides, age and sex. CONCLUSIONS: According to available research, this research is the first study showing that sST2 concentration is related with nutritional status in HFrEF patients. sST2 may help to evaluate the necessity for nutritional intervention in HFrEF patients.

Redox homeostasis in human renal cells that had been treated with amphotericin B in combination with selected 1,3,4-thiadiazole derivatives.

BACKGROUND: The use of amphotericin B (AmB) in the therapy of systemic mycosis is associated with strong side effects, including nephrotoxicity, and hepatotoxicity. Therefore, agents that can reduce the toxic effects of AmB while acting synergistically as antifungal agents are currently being sought. 1,3,4-thiadiazole derivatives are promising compounds that have an antifungal activity and act synergically with AmB. Such combinations might allow the dose of AmB, which is essential for preventing patients from having serious side effects, to be decreased. This might result from the antioxidant properties of 1,3,4-thiadiazoles. Thus, the aim of the study was to investigate redox homeostasis in human renal proximal tubule epithelial cells (RPTEC) after they had been treated with AmB in combination with 1,3,4-thiadiazole derivatives. METHODS: Cellular redox homeostasis was assessed by investigating the total antioxidant capacity (TAC) of cells, the malondialdehyde (MDA) concentration, and the activity of antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT). TAC was measured using an ABTS method. The MDA concentration, and the activity of SOD, GPX, and CAT were determined spectrophotometrically using commercially available assays. Additionally, the antioxidant defense system-related gene expression profile was determined using oligonucleotide microarrays (HG-U133A 2.0). Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used to confirm the microarray results. RESULTS: Amphotericin B and selected 1,3,4-thiadiazole derivatives had a significant effect on the total antioxidant capacity of the RPTEC cells, and the activity of the antioxidant enzymes. We also revealed that the effect of thiadiazoles on the SOD and CAT activities is dependent on the treatment of RPTEC cells with AmB. At the transcriptional level, the expression of several genes was affected by the studied compounds and their combinations. CONCLUSIONS: The results confirmed that thiadiazoles can stimulate the RPTEC cells to defend against the oxidative stress that is generated by AmB. In addition, together with the previously demonstrated synergistic antifungal activity, and low nephrotoxicity, these compounds have the potential to be used in new therapeutic strategies in the treatment of fungal infections.

Static Magnetic Field Reduces the Anticancer Effect of Hinokitiol on Melanoma Malignant Cells-Gene Expression and Redox Homeostasis Studies.

BACKGROUND: Melanoma malignant is characterized by a high mortality rate, accounting for as much as 65% of deaths caused by skin cancer. A potential strategy in cancer treatment may be the use of natural compounds, which include hinokitiol (ß-Thujaplicin), a phenolic component of essential oils extracted from cypress trees. Many studies confirm that a high-induction SMF (static magnetic field) has anticancer effects and can be used as a non-invasive anticancer therapy in combination with or without drugs. AIM: The aim of this experiment was to evaluate the effect of a static magnetic field on melanoma cell cultures (C32 and COLO 829) treated with hinokitiol. METHODS AND RESULTS: Melanoma cells were exposed to a static magnetic field of moderate induction and hinokitiol. The research included determining the activity of the antioxidant enzymes (SOD, GPx, and CAT) and MDA concentration as well as the gene expression profile. CONCLUSION: Hinokitiol disturbs the redox homeostasis of C32 and COLO 829 melanoma malignant cells. Moreover, a static magnetic field has a protective effect on melanoma malignant cells and abolishes the anticancer effect of hinokitiol.

Kinin Receptors and Kinin-Related Gene Expression in Astrocytic Brain Tumors.

Kinins are a set of peptides present in tissues that are involved in the inflammatory response and cancer progression. However, studies showing the expression of kinin receptors in human glioma samples are still incomplete and contradictory. The aim of the present study was to ascertain the expression of BDKRB1 and BDKRB2 genes, as well as the level of B1R and B2R proteins in human gliomas, depending on the degree of malignancy. Additionally, representative kinin-dependent genes with altered expression were indicated. The expression profile of kinin-dependent genes was determined using oligonucleotide microarray technique. In addition, RT-qPCR was used to assess the expression level of selected differentiating genes. The location of kinin receptors in brain gliomas was assessed using immunohistochemical methods. The oligonucleotide microarray method was used to identify 12 mRNA IDs of kinin-related genes whose expression was upregulated or downregulated in gliomas of different grades. In immunohistochemically stained samples, the concentrations of BR1 and BR2 proteins, measured by optical density, were statistically significantly higher in grade G3 vs. G2 and G4 vs. G3. Increased expression of kinin receptors BDKRB1 and BDKRB2 in brain gliomas, depending on the degree of malignancy, suggests the involvement of kinins and their receptors in the disease's pathogenesis. Quantitative assessment of mRNA BDKRB1, PRKAR1A, MAP2K, and EGFR in patients with brain tumors may hold diagnostic and therapeutic significance.

Sex differences in the nutritional status and its association with long-term prognosis in patients with heart failure with reduced ejection fraction: a prospective cohort study.

AIMS: Many studies show the association between malnutrition and poor prognosis in heart failure (HF) patients. Our research aimed to analyse sex differences in patients with HF with reduced ejection fraction (HFrEF), emphasizing nutritional status and the influence of selected parameters on the prognosis. METHODS AND RESULTS: We enrolled 276 consecutive patients diagnosed with HFrEF. Nutritional status was assessed using Mini Nutritional Assessment (MNA), geriatric nutritional risk index (GNRI), and body mass index (BMI). The mean follow-up period was 564.4 ± 346.3 days. The analysed group included 81.2% of men. The median age was 58, interquartile range (IQR) 49-64 years. Among all patients, almost 60% were classified as NYHA III or IV. Half of the participants were at risk of malnutrition, and 2.9% were malnourished. During follow-up, 72 (26.1%) patients died. The female sex was not associated with a higher occurrence of malnutrition (P = 0.99) or nutritional risk (P = 0.85), according to MNA. Coherently, GNRI scores did not differ significantly between the sexes (P = 0.29). In contrast, BMI was significantly higher in males (29.4 ± 5.3 vs. 25.9 ± 4.7; P < 0.001). Impaired nutritional status assessed with any method (MNA, GNRI, BMI) was not significantly associated with a worse prognosis. In multivariable analysis, NYHA class, lower estimated glomerular filtration rate, higher B-type natriuretic peptide (BNP), higher N-terminal fragment of proBNP, and higher uric acid were independent of sex and age predictors of all-cause mortality. CONCLUSION: There were no sex differences in the nutritional status in the HFrEF patients, apart from lower BMI in females. Impaired nutritional status was not associated with mortality in both men and women.

Characters evolution of Encyclia (Laeliinae-Orchidaceae) reveals a complex pattern not phylogenetically determined: insights from macro- and micromorphology.

Encyclia is the second-largest genus in the neotropical subtribe Laeliinae (Orchidaceae) and has more than 150 species, which are characterized by fairly consistent flower morphology. Its taxonomy and species boundaries, however, seem to be still under debate. In the present study, we first examined the lip micromorphology of 61 species of Encyclia sensu stricto. We correlated our results with external flower morphology and phylogenetic analyses performed on a combined dataset that included both nuclear (ITS, Xdh, PhyC) and plastid markers (ycf1, rpl32, and trnL-trnF). Phylogenetic reconstruction showed that Encyclia sensu stricto species form a coherent, monophyletic group. However, it is difficult to determine the relationships between the different groups within one larger clade. The groups all form distinct lineages that evolved from a common ancestor. The UPGMA cluster analysis for the seven qualitative micromorphological features clearly divides the genus into two main groups, the larger of which is further subdivided into two subgroups. None of these, however, overlap with any of the phylogeographic units distinguished in previously published papers or in presented article. It is worth noting that the groups resulting from the UPGMA analysis cannot be defined by macromorphological features. The pattern of similarities between species, taking into account both macro- and micromorphological features, is eminently mosaic in nature, and only a multifaceted approach can explain this enigmatic group.

Understanding Yb3+-sensitized photon avalanche in Pr3+ co-doped nanocrystals: modelling and optimization.

Among different upconversion processes where the emitted photon has higher energy than the one absorbed, photon avalanche (PA) is unique, because the luminescence intensity increases by 2-3 orders of magnitude in response to a tiny increase in excitation intensity. Since its discovery in 1979, PA has been observed in bulk materials but until recently, obtaining it at the nanoscale has been a significant challenge. In the present work, the PA phenomenon in ß-NaYF4 colloidal nanocrystals co-doped with Pr3+ and Yb3+ ions was successfully observed at 482 nm (3P0 → 3H4) and 607 nm (3P0 → 3H6) under excitation at 852 nm. The impact of Pr3+ ion concentration and pump power dependence on PA behavior was investigated, i.e. PA non-linearity slopes of luminescence intensity curves as a function of pump power density as well as PA thresholds. The highest slopes, namely 8.6 and 9.0, and the smallest thresholds equal to 286 kW cm-2 and 281 kW cm-2, observed for emission bands at 607 nm and 482 nm, respectively, were obtained for NaYF4:0.5%Pr3+,15%Yb3+@NaYF4 colloidal nanocrystals. Besides experimental research, simulations of PA behavior in Pr3+, Yb3+ co-doped materials were performed based on differential rate equations describing the phenomena that contribute to the existence of PA. The influence of different processes leading to PA, e.g. the rates of nonradiative and radiative transitions as well as energy transfers, on PA performance was simulated aiming to understand their roles in this complex sensitized system.

Effects of Water-Ethanol Extracts from Four Sphagnum Species on Gene Expression of Selected Enzymes in Normal Human Dermal Fibroblasts and Their Antioxidant Properties.

Mosses (Bryophyta), particularly species of the genus Sphagnum, which have been used for centuries for the treatment of skin diseases and damage, are still not explored enough in terms of their use in cosmetics. The purpose of this study was to determine the antioxidant properties of water-ethanol extracts from four selected species of the genus Sphagnum (S. girgenshonii Russow, S. magellanicum Brid., S. palustre L., and S. squarrosum Crome) and their impact on the expression of genes encoding key enzymes for the functioning of the skin. In this study, the effects of Sphagnum extracts on the expression of genes encoding tyrosinase, collagenase, elastase, hyaluronidase and hyaluronic acid synthase in human dermal fibroblasts were determined for the first time in vitro. The extracts inhibited tyrosinase gene expression and showed antioxidant activity. The experiment showed an increase in the expression of some genes encoding collagenase (MMP1) or hyaluronidase (HYAL2, HYAL3 and HYAL4) and a decrease in the hyaluronan synthase (HAS1, HAS2 and HAS3) genes expression by the tested extracts. The obtained results suggest that using extracts from the tested Sphagnum species in anti-aging cosmetics does not seem beneficial. Further studies are needed to clarify their impact on the skin.

The influence of adalimumab treatment on the systemic gene expression in patients with psoriatic arthritis - preliminary report.

Introduction: The primary goal of psoriasis treatment is to reduce the inflammatory response and associated complications. In severe cases of psoriasis that are resistant to local treatment (e.g., keratolytic preparations) and at least two types of general treatment methods (e.g., retinoids and cyclosporine A), biological therapy is used. This study aimed to assess the systemic effects of adalimumab at a given stage of treatment in patients with psoriatic arthritis and evaluate how the drug can improve the clinical condition of the patients. Material and methods: The study group consisted of patients with diagnosed psoriatic arthritis, while the control group consisted of individuals from whom peripheral blood mononuclear cells were obtained. The effects of the administration of adalimumab were assessed by analyzing the gene expression using oligonucleotide microarrays. Result: The apoptosis process was found to be one of the overrepresented categories (the PANTHER classification system 13.1 program, overrepresentation test, p < 0.05). The dermatological indexes decreased, indicating an improvement in the clinical conditions of the patients 3 months after the first dose of adalimumab. Conclusions: We found that adalimumab affects apoptosis, which is crucial in the development and course of psoriasis. The differential gene expression in peripheral blood mononuclear cells of patients with psoriatic arthritis indicated the potential systemic effects of adalimumab therapy. The analyses of dermatological (the Psoriasis Area and Severity Index, body surface area and Dermatology Life Quality Index) and inflammatory (Biernacki's reaction) parameters revealed the effectiveness of the therapy.

Notes to the Taxonomic Affiliation of the Bulbophyllym Sect. Physometra (Orchidaceae, Epidendroideae) Based on Molecular Phylogenetic Analyses.

To solve the taxonomic affiliation of Bulbophyllum physometrum, the only known species of the Bulbophyllym sect. Physometra (Orchidaceae, Epidendroideae), we conducted phylogenetic analyses based on nuclear markers, i.e., ITS and the low-copy gene Xdh, and the plastid region matK. We used Asian Bulbophyllum taxa, with a special focus on species from the sections Lemniscata and Blepharistes, i.e., the only Asian sections of this genus with bifoliate pseudobulbs, as in B. physometrum. Unexpectedly, the results of molecular phylogenetic analyses showed that B. physometrum is most probably more related to the representatives of the sections Hirtula and Sestochilos than Blepharistes or Lemniscata.

sST2 and Heart Failure-Clinical Utility and Prognosis.

New parameters and markers are constantly being sought to help better assess patients with heart failure (HF). ST2 protein has gained interest as a potential biomarker in cardiovascular disease. It is known that the IL-33/ST2L system belongs to the cardioprotective pathway, which prevents the fibrosis, hypertrophy, and apoptosis of cardiomyocytes and also inhibits the inflammatory response. Soluble ST2 (sST2) is involved in the immune response and secreted in response to the mechanical overload of the myocardium, thus providing information on the processes of myocardial remodeling and fibrosis. A total of 110 hospitalized patients diagnosed with heart failure with reduced ejection fraction (HFrEF) were included in the study. Clinical and biochemical parameters were studied. During the follow-up, 30.9% patients died and 57.3% patients reached the composite endpoint. Using ROC curves, the reference cut-off point for sST2 was determined to be 45.818 pg/mL for all-cause deaths. Significantly higher concentrations of inflammatory parameters and natriuretic peptides were found in the group of patients with higher sST2 concentrations. sST2 protein is an independent risk factor for all-cause deaths of patients with HFrEF.

Phenolic acids and a static magnetic field change the expression of transforming growth factor ß isoforms in amelanotic melanoma cells.

BACKGROUND: Melanoma is an aggressive type of cancer that can metastasize to numerous other organs. TGFß is one of the key signaling pathways in melanoma progression. Previous studies on various types of cancer have shown that both: polyphenols and a static magnetic field (SMF) can be potential chemopreventive/therapeutic agents. Therefore, the aim of the study was to evaluate the effect of a SMF and selected polyphenols on the transcriptional activity of TGFß genes in melanoma cells. METHODS AND RESULTS: Experiments were performed on the C32 cell line treated with caffeic or chlorogenic acids, and with simultaneous exposure to a moderate-strength SMF. The RT-qPCR method was used to determine the mRNA level of genes encoding the TGFß isoforms and their receptors. The concentration of the TGFß1 and TGFß2 proteins were also measured in the cell culture supernates. The first response of C32 melanoma cells to both factors is the reduction of TGFß levels. Then, mRNA level of these molecules returned to values close to pre-treatment level by the end of experiment. CONCLUSION: Our study results demonstrate the potential of polyphenols and a moderate-strength SMF to support cancer therapy by altering TGFß expression, which is a very promising topic for the diagnosis and treatment of melanoma.

Functionalized Halloysite Nanotubes as Potential Drug Carriers.

The aim of the work was to examine the possibility of using modified halloysite nanotubes as a gentamicin carrier and to determine the usefulness of the modification in terms of the effect on the amount of the drug attached, its release time, but also on the biocidal properties of the carriers. In order to fully examine the halloysite in terms of the possibility of gentamicin incorporating, a number of modifications of the native halloysite were carried out prior to gentamicin intercalation with the use of sodium alkali, sulfuric and phosphoric acids, curcumin and the process of delamination of nanotubes (expanded halloysite) with ammonium persulfate in sulfuric acid. Gentamicin was added to unmodified and modified halloysite in an amount corresponding to the cation exchange capacity of pure halloysite from the Polish Dunino deposit, which was the reference sample for all modified carriers. The obtained materials were tested to determine the effect of surface modification and their interaction with the introduced antibiotic on the biological activity of the carrier, kinetics of drug release, as well as on the antibacterial activity against Escherichia coli Gram-negative bacteria (reference strain). For all materials, structural changes were examined using infrared spectroscopy (FTIR) and X-ray diffraction (XRD); thermal differential scanning calorimetry with thermogravimetric analysis (DSC/TG) was performed as well. The samples were also observed for morphological changes after modification and drug activation by transmission electron microscopy (TEM). The conducted tests clearly show that all samples of halloysite intercalated with gentamicin showed high antibacterial activity, with the highest antibacterial activity for the sample modified with sodium hydroxide and intercalated with the drug. It was found that the type of halloysite surface modification has a significant effect on the amount of gentamicin intercalated and then released into the surrounding environment but does not significantly affect its ability to further influence drug release over time. The highest amount of drug released among all intercalated samples was recorded for halloysite modified with ammonium persulfate (real loading efficiency above 11%), for which high antibacterial activity was found after surface modification, before drug intercalation. It is also worth noting that intrinsic antibacterial activity was found for non-drug-intercalated materials after surface functionalization with phosphoric acid (V) and ammonium persulfate in the presence of sulfuric acid (V).

Schiedeella bajaverapacensis (Orchidaceae, Spiranthinae), a New Orchid Species from Guatemala.

Guatemala is recognized for its diverse and rich flora and fauna. It is estimated that over 1200 orchid species, classified in 223 genera, are known to occur in this rather small, yet megadiverse country. While studying the diversity of this plant group in the department of Baja Verapaz, we found individuals that clearly belonged to the genus Schiedeella, but whose features did not fit any previously known species. At that time, nine terrestrial taxon representatives were known to occur in Guatemala. We conducted the morphological analysis in accordance with the standard procedures of classical taxonomy. For phylogenetic reconstruction, 59 sequences of the ITS region and 48 of the trnL-trnF marker were applied. The topology of trees was obtained based on the Bayesian inference. Schiedeella bajaverapacensis was described and illustrated based on morphological evidence, and its taxonomic position was confirmed by phylogenetic analyses. The new entity is the 10th Schiedeella representative known from Guatemala.

Changes in the Expression Profile of Pyroptosis-Related Genes in Senescent Retinal Pigment Epithelial Cells after Lutein Treatment.

Retinal pigment epithelium (RPE) is a specialized structure essential for proper vision, which is constantly exposed to oxidative damage. With aging, this damage accumulates within the RPE cells, causing various diseases, including age-related macular degeneration (AMD). Numerous antioxidant substances are used to prevent this process in humans, including lutein. This study aims to determine the differences in the expression patterns of pyroptosis genes in senescent human retinal pigment epithelial cell line ARPE-19 exposed to lutein. Changes in the expression of pyroptosis-related genes were assessed by oligonucleotide microarrays, and the results were validated by real-time RT-qPCR. The microarray analysis showed seven transcripts were differentially expressed both in the H2O2-treated cells versus the controls and in the lutein/H2O2-treated cells compared to the H2O2-treated cells (FC > 2.0). Depending on the used lutein, H2O2, or co-treatment of ARPE-19 cells, statistically significant differences in the expression of TXNIP, CXCL8, BAX, and CASP1 genes were confirmed by the RT-qPCR (p < 0.05). A STRING database analysis showed that the proteins encoded by the analyzed genes form a strong interaction network (p < 0.001). These data indicate that lutein modulates the expression level of pyroptosis-related genes, which may be useful for the development of new methods preventing pyroptosis pathway activation in the future.

Comparison of the population of Polish patients participating in the TRANSITION study with the international population: a post hoc analysis.

INTRODUCTION: Heart failure (HF) patients discharged from a hospital are at a high risk of death and rehospitalization. Scarce data are available on the use of sacubitril / valsartan in this population in Poland. OBJECTIVE: The aim of this study was to compare the efficacy and tolerability of sacubitril / valsartan in the group of Polish patients who participated in the TRANSITION study with the patients recruited at other sites. PATIENTS AND METHODS: This is a post hoc secondary analysis of the TRANSITION study comparing sacubitril / valsartan initiation pre- vs postdischarge in 991 patients hospitalized for acute decompensated HF with reduced ejection fraction (HFrEF). The Polish subgroup consisted of 104 patients. RESULTS: Significant differences were identified in the characteristics of Polish vs non­Polish populations. At baseline, the Polish population showed higher proportion of men, higher body mass index, lower heart rate, N­terminal pro-B­type natriuretic peptide and high­sensitivity troponin T levels, and significantly lower New York Heart Association class. The Polish patients were better managed in terms of implanted electrotherapy devices, percutaneous coronary interventions, and drug therapy, and were more often hospitalized. The primary end point of achieving the target dose of sacubitril / valsartan at treatment week 10 was met by 45.6% of the Polish patients and 48.4% of the non­Polish population (P = 0.61). Approximately 90% of the Polish patients received and maintained any sacubitril / valsartan dose for 2 weeks over 10­week treatment vs 87.5% of the non­Polish patients (P = 0.36). The rate of permanent sacubitril / valsartan treatment discontinuation was low in both Polish (3.9%) and non­Polish populations (6.4%) (P = 0.33). CONCLUSIONS: Sacubitril / valsartan can be used safely in the early period after an episode of acute HF both in the Polish and non­Polish patients with HFrEF, and the likelihood to achieve the maximum dose is the same despite significant differences between the studied populations.

The MAP2K2 Gene as Potential Diagnostic Marker in Monitoring Adalimumab Therapy of Psoriatic Arthritis.

BACKGROUND: MAP kinases are some of the cascades that are specialized in the cell's response to external stimuli. Their impaired functioning can be observed during the course of psoriatic arthritis. Currently, the best-known class of biological drugs is the inhibitors of the proinflammatory cytokine TNF-α, including adalimumab. OBJECTIVE: The aim of this study was to assess changes in the expression of MAP kinase genes in patients with psoriatic arthritis treated with adalimumab, as well as to determine which of the analyzed transcripts could be used as a diagnostic or therapeutic target. METHODS: An analysis was performed on the total RNA extracted from PBMCs of patients with psoriatic arthritis before and after three months of adalimumab therapy as well as from a control group. Changes in the expression of the mitogen-activated protein kinase genes were assessed using the HG-U133A 2.0 oligonucleotide microarray method, while the obtained results were validated using the real-time RT-qPCR method. RESULTS: Using the oligonucleotide microarray method, 14 genes coded for proteins from the MAPK group were identified with at least a two-fold change of expression in the control group and during adalimumab therapy. Validation of the results confirmed a statistically significant decrease in the transcriptional activity of the MAP2K2 gene in the group of patients three months after the administration of adalimumab relative to the control group. CONCLUSION: Adalimumab therapy alters the expression of MAPK-coding genes. The assessment of the number of MAP2K2 mRNA molecules can potentially be used in diagnostic analyses or in monitoring adalimumab therapy.

Effect of Antibiotic Amphotericin B Combinations with Selected 1,3,4-Thiadiazole Derivatives on RPTECs in an In Vitro Model.

4-(5-methyl-1,3,4-thiadiazole-2-yl) benzene-1,3-diol (C1) and 4-[5-(naphthalen-1-ylmethyl)-1,3,4-thiadiazol-2-yl] benzene1,3-diol (NTBD) are representative derivatives of the thiadiazole group, with a high antimycotic potential and minimal toxicity against normal human fibroblast cells. The present study has proved its ability to synergize with the antifungal activity of AmB. The aim of this work was to evaluate the cytotoxic effects of C1 or NTBD, alone or in combination with AmB, on human renal proximal tubule epithelial cells (RPTECs) in vitro. Cell viability was assessed with the MTT assay. Flow cytometry and spectrofluorimetric techniques were used to assess the type of cell death and production of reactive oxygen species (ROS), respectively. The ELISA assay was performed to measure the caspase-2, -3, and -9 activity. ATR-FTIR spectroscopy was used to evaluate biomolecular changes in RPTECs induced by the tested formulas. The combinations of C1/NTBD and AmB did not exert a strong inhibitory effect on the viability/growth of kidney cells, as evidenced by the negligible changes in the apoptotic/necrotic rate and caspase activity, compared to the control cells. Both NTBD and C1 displayed stronger anti-oxidant activity when combined with AmB. The relatively low nephrotoxicity of the thiadiazole derivative combinations and the protective activity against AmB-induced oxidative stress may indicate their potential use in the therapy of fungal infections.

Micromorphology of Labellum in Selected Dendrobium Sw. (Orchidaceae, Dendrobieae).

Dendrobium is one of the most species-rich genera of the Paleotropical orchids. It embraces more than 1000 species, most of which are epiphytes. The strong variation in floral characters causes many identification difficulties within this genus. One of the key structures, often sufficient in identification on a species level, is the labellum, which in many species of Dendrobium possesses a thickened callus and various types of trichomes and papillae. The aim of this study is to identify and describe the structures present on the labellum surface of the analyzed species, determine their distribution and density, as well as to check whether the obtained data have taxonomic value. In this paper, we present the results of a micromorphological study on the labellum of 21 species of Dendrobium, representing 13 sections, using scanning electron microscopy (SEM). Our studies revealed the presence of both uni- and multicellular structures on the surface of the labellum. We observed three types of trichomes (conical, cylindrical, ellipsoidal) and three types of papillae (conical, cylindrical, semicircular). Neither trichomes nor papillae were recorded for five species. In addition, we made diagrams showing the distribution and density of structures on the labellum. Based on the micromorphological results combined with the phylogenetic tree performed, we suggest that the presence/absence of labellum structures does not necessarily reflect the phylogenetic relationship and might be misleading, as in some cases, they arise due to convergence.

Niche conservatism and evolution of climatic tolerance in the Neotropical orchid genera Sobralia and Brasolia (Orchidaceae).

Sobralia and Brasolia form a large complex of Neotropical Orchidaceae. Although the molecular and morphological studies allowed to increase the rate of work on the modern classification of the taxa, they still require the attention as remaining without complete revision. The niche similarity analysis between representatives of Sobralia and recently segregated from this taxon-genus Brasolia is presented. The ecological tolerance evolution within the group was investigated with molecular clock analysis and phylogeny as the background. The phylogenetic analysis has confirmed the previous results and placed Brasolia representatives in a single clade with Elleanthus and Sobralia core as a separated group. The molecular clock analysis suggests that Sobralia and Brasolia are relatively young groups that evolved between 8.5 and 8 million years ago. Distribution of suitable niches of studied species is generally congruent with the known geographical ranges of particular taxa. The calculated niche overlap did not indicate any correlation between niche overlap and species phylogenetic relationships and remains low for both intra- and intergeneric relationships. The reconstruction of climatic tolerance evolution indicated that the studied species of Brasolia and Sobralia are characterized by generally similar ecological tolerance for most of the analyzed variables.