Biological and chemical contamination of illegal, uncontrolled refuse storage areas in Poland

This study focused on assessing the microbiological and chemical contamination of air, soil and leachate in uncontrolled refuse storage areas in central Poland. The research included an analysis of the number of microorganisms (culture method), endotoxin concentration (gas chromatography-mass spectrometry), heavy metals level (atomic absorption spectrometry), elemental characteristics (elemental analyser), cytotoxicity assessment against A-549 (human lung) and Caco-2 (human colon adenocarcinoma) cell lines (PrestoBlue™ test) and toxic compound identification (ultra-high-performance liquid chromatography-quadrupole time-of-flight ultrahigh-resolution mass spectrometry). Microbial contamination differed depending on the dump and the group of tested microorganisms. The number of bacteria was: 4.3 × 10² - 1.8 × 10³ CFU m^-3 (air); 1.1 × 10³ - 1.2 × 10⁶ CFU mL^-1 (leachate); 1.0 × 10⁶ - 3.9 × 10⁶ CFU g^-1 (soil). Respectively, for air and soil the number of fungi was: 2.2 × 10² - 4.6 × 10² CFU m^-3; 1.8 × 10² - 3.9 × 10³ CFU g^-1. Metal levels (Fe, Mn, Pb, Zn, Al, Hg, Cd, Cu, Cr) were higher than in the control sample; however, the average concentrations did not exceed the permissible standards. The cytotoxicity of soil and leachate samples depended on the dump, sample and cell line tested. The leachates were more cytotoxic than soil extracts. Compounds belonging to pesticides, surfactants and biocides, chemicals and/or polymer degradation products, medicinal drugs and insect repellents were found. The detection of potential pathogens in the air, soil and leachate, the presence of toxic compounds and the confirmation of the cytotoxic effect of leachate and soil on human cell lines justify the need for further research on the risks posed by illegal dumps. These studies should aim at developing a unified assessment method and a method to minimise the risk of contaminants spreading in the environment, including harmful biological agents.

Review of harmful chemical pollutants of environmental origin in honey and bee products

Honey is a natural food with many pro-health properties, which comprises a wide variety of valuable ingredients. It can also be the source of chemical contaminants of environmental origin, including POPs that can contribute to adverse health effects to human. Monitoring the degree of pollution of honey/bee products with hazardous chemicals is important from a nutraceutical point of view. In the present work, overview of recent literature data on chemical pollutants in honey/bee products originating from the environment was performed. Their MLs, MRLs and EDI were discussed. It can be concluded that huge amount of research concerned on the presence of TMs and pesticides in honey. Most of the studies have shown that honey/bee products sampled from urban and industrialized areas were more contaminated than these sampled from ecological and rural locations. More pollutants were usually detected in propolis and bee pollen than in honey. Based on their research and regulations, authors stated, that most of the toxic pollutants of environmental origin in honey/bee products are at levels that do not pose a threat to the health of the potential consumer. The greatest concern relates to pesticides and TMs, because in some research MLs in individual samples were highly exceeded.

Probiotics and Postbiotics as Substitutes of Antibiotics in Farm Animals: A Review

Simple Summary

Breeders are searching for methods to protect farming animals against diseases caused by pathogenic bacteria. The easiest way to fight bacteria is to use antibiotics. Unfortunately, their abuse results in the presence of bacteria resistant to the most commonly used antibiotics in the environment. The restrictions on the use of antibiotics have forced the search for natural and safe ways to protect animals. It has been shown that the use of probiotics based on lactic acid bacteria may have a positive effect on the growth and use of feed by broilers, on the stabilization of the intestinal microbiota of chickens and pigs, and in the prevention of mastitis in dairy cows. The use of probiotics (live, nonpathogenic microorganisms) and postbiotics (inanimate bacteria, cell components or post-fermentation by-products) reduces the occurrence of pathogens in large-scale farms.

Abstract

Since 2006, the use of growth-promoting antibiotics has been banned throughout the European Union. To meet the expectations of livestock farmers, various studies have been carried out with the use of lactic acid bacteria. Scientists are trying to obtain the antimicrobial effect against the most common pathogens in large-scale farms. Supplementing the diet of broilers with probiotics (live, nonpathogenic microorganisms) stabilized the intestinal microbiota, which improved the results of body weight gain (BWG) and feed intake (FI). The positive effect of probiotics based on lactic acid bacteria has been shown to prevent the occurrence of diarrhea during piglet weaning. The antagonistic activity of postbiotics (inanimate bacteria, cell components, or post-fermentation by-products) from post-culture media after lactobacilli cultures has been proven on Staphylococcus aureus—the pathogen most often responsible for causing mastitis among dairy cows. The article aims to present the latest research examining the antagonistic effect of lactic acid bacteria on the most common pathogens in broilers, piglets, pigs, and cow farms.

Effects of Insecticides and Microbiological Contaminants on Apis mellifera Health

Over the past two decades, there has been an alarming decline in the number of honey bee colonies. This phenomenon is called Colony Collapse Disorder (CCD). Bee products play a significant role in human life and have a huge impact on agriculture, therefore bees are an economically important species. Honey has found its healing application in various sectors of human life, as well as other bee products such as royal jelly, propolis, and bee pollen. There are many putative factors of CCD, such as air pollution, GMO, viruses, or predators (such as wasps and hornets). It is, however, believed that pesticides and microorganisms play a huge role in the mass extinction of bee colonies. Insecticides are chemicals that are dangerous to both humans and the environment. They can cause enormous damage to bees' nervous system and permanently weaken their immune system, making them vulnerable to other factors. Some of the insecticides that negatively affect bees are, for example, neonicotinoids, coumaphos, and chlorpyrifos. Microorganisms can cause various diseases in bees, weakening the health of the colony and often resulting in its extinction. Infection with microorganisms may result in the need to dispose of the entire hive to prevent the spread of pathogens to other hives. Many aspects of the impact of pesticides and microorganisms on bees are still unclear. The need to deepen knowledge in this matter is crucial, bearing in mind how important these animals are for human life.

Drug-Eluting Stents and Balloons-Materials, Structure Designs, and Coating Techniques: A Review

Controlled drug delivery is a matter of interest to numerous scientists from various domains, as well as an essential issue for society as a whole. In the treatment of many diseases, it is crucial to control the dosing of a drug for a long time and thus maintain its optimal concentration in the tissue. Heart diseases are particularly important in this aspect. One such disease is an obstructive arterial disease affecting millions of people around the world. In recent years, stents and balloon catheters have reached a significant position in the treatment of this condition. Balloon catheters are also successfully used to manage tear ducts, paranasal sinuses, or salivary glands disorders. Modern technology is continually striving to improve the results of previous generations of stents and balloon catheters by refining their design, structure, and constituent materials. These advances result in the development of both successive models of drug-eluting stents (DES) and drug-eluting balloons (DEB). This paper presents milestones in the development of DES and DEB, which are a significant option in the treatment of coronary artery diseases. This report reviews the works related to achievements in construction designs and materials, as well as preparation technologies, of DES and DEB. Special attention was paid to the polymeric biodegradable materials used in the production of the above-mentioned devices. Information was also collected on the various methods of producing drug release coatings and their effectiveness in releasing the active substance.

Abstract B76: Discovery of novel first-in-class nucleotide analogs as RIG-I agonists for immuno-oncology

Background: Agents that activate innate and adaptive immunity have the potential for transformative immunotherapeutic approach in cancer treatment. Recent evidence suggests that the induction of innate immunity via the activation of RIG-I pathway in tumor cells, as well as immune cells in the tumor microenvironment (TME), can produce type I Interferons and cytokines for the induction of adaptive immunity as well as tumor cell death, thereby synergizing antitumoral effects. We describe here the discovery of highly potent first-in-class nucleotide compounds as RIG-I agonists.

Methods: Synthesis: Using published crystal structure of 5´ppp-dsRNA bound to RIG-I in conjunction with structure-guided drug design, a focused library of more than 100 nucleotide compounds was generated and evaluated in multiple assays: (i) RIG-I binding affinity: Differential scanning fluorimetry was used to screen compounds for determining binding affinity to RIG-I (ii) Induction of IRF3: Compounds were assessed for IRF3 induction in doses ranging from 1 ug/mL to 100 ug/mL, using wild-type- and RIG-I-knockout mouse RAW cells, as well as, THP-1 cells carrying lucia reporter gene under the control of ISG54 minimal promoter and lead compounds were identified; (iii) Induction of cytokines: Lead compounds @ 100ug/ml were further evaluated for the induction of IFN-β and other cytokines in PBMCs and mouse bone-marrow-derived dendritic cells (mBMDCs) by Luminex analysis; (iv) Induction of Interferon Stimulated Genes (ISGs): ISGs such as DDX58, IFIT1, IFIT12, and IFIT13 were assessed by quantitative RT-PCR following treatment of the compounds in THP1 cells, PBMCs, and mBMDCs; (v) Induction of apoptosis in CT26 colon carcinoma cells: For determining apoptotic activity, CT26 cells were treated with various concentrations of the lead compounds, pppdsRNA or vehicle control and the apoptotic activity was measured using Caspase-Glo® 3/7 Assay (Promega). (vi) Release of DAMPs in CT26 colon carcinoma cells: For evaluating release of ATP and HMGB1, CT26 cells were treated with various concentrations of the lead compounds and supernatants were tested for presence of ATP and HMGB1 by ELISA.

Results: Through in vitro assays in conjunction with SAR studies, we have identified several potent and selective first-in-class nucleotide compounds as RIG-I agonists. Two lead nucleotide compounds, SB 1 and SB 2, activated RIG-I in a dose-dependent manner to induce IRF3 signaling pathway in various cells. SB 1 and 2 also showed potent in vitro antitumor activity in multiple cell lines via both RIG-I dependent apoptosis of tumor cells and through the induction of IFNs, ISGs, and other cytokines, along with the expression of PRRs and ISGs including DDX58 IFIT1, IFIT2, and IFIT3.

Conclusion: Highly potent RIG-I agonists that show excellent selectivity in the induction of IFN, NF-KB, ISGs, and PRRs and apoptosis of tumor-derived cell lines have been identified. The lead nucleotide compounds are being advanced for preclinical studies for applications in immuno-oncology.

Citation Format: Sreerupa Challa, Ireneusz Nowak, Geeta Meher, Rayomand Gimi, Seetharamaiyer Padmanabhan, Dillon Cleary, Leena Suppiah, Diane Schmidt, Sam Baskaran, Lakshmi Bhagat, Radhakrishnana Iyer. Discovery of novel first-in-class nucleotide analogs as RIG-I agonists for immuno-oncology [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B76.

Endoplasmic reticulum aminopeptidase 1 polymorphism Ile276Met is associated with atopic dermatitis and affects the generation of an HLA-C associated antigenic epitope in vitro

BACKGROUND

Atopic dermatitis (AD) is a common inflammatory skin disease of complex aetiology, with interactions between susceptibility genes and environmental factors. We have previously described a protective effect of the KIR2DS1 gene encoding the natural killer cell receptor, whose ligands are HLA-C molecules. Here, we found an association of HLA-C*05:01 allele with AD. KIR-HLA-C interactions are affected by peptides presented by HLA-C. The generation of these peptides is strongly influenced by endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2). Expression and activity of ERAP molecules depend on the polymorphisms of their genes.

OBJECTIVE

Possible associations of several single nucleotide polymorphisms (SNPs) in the ERAP1 and ERAP2 genes with susceptibility to AD.

METHODS

Peripheral blood DNA isolation from 318 patients and 549 controls. PCR-SSO or PCR-SSP for HLA-C typing; TaqMan Genotyping Assay for ERAP typing.

RESULTS

Only one SNP in the ERAP1 gene, rs26618T>C, causing the amino acid change Ile276Met, had an association with AD. To gain insight on the functional role of this SNP, we produced recombinant variants differing only at position 276 (Ile or Met) and tested their aminopeptidase activity against a N-terminally extended precursor LIVDRPVTLV of the HLA-C*05:01 epitope IVDRPVTLV. Both ERAP1 variants were able to efficiently generate the epitope, although the 276Ile allotype was able to do this about 50% faster. Furthermore, both variants were quite inefficient in further degradation of the mature epitope. Finally, we found that the effect of 276Met on susceptibility to AD was seen only in KIR2DS1-negative individuals, not protected by this KIR.

CONCLUSION

Associations of HLA-C*05:01 allele and rs26618T>C (Ile276Met) ERAP1 polymorphism with AD, and a significant difference between these two ERAP1 variants in their ability to generate an epitope for the HLA-C*05:01 molecule was found.

Evaluation of sex-related changes in skin topography and structure using innovative skin testing equipment

BACKGROUND

Evaluation of skin condition on the basis of parametrization and objective measurements of the parameters has become obligatory. The aim of this study was to assess sex-related changes in skin topography and structure using the skin testing equipment.

MATERIALS AND METHODS

The study was carried out on the group of 40 volunteers (20 females and 20 males) of the mean age 24 ± 3 years. The skin parameters were measured using 3 devices: Visioscan^®  VC 98 (skin topography), Visioline^® VL 650 (skin macro relief) and Ultrascan UC22 (ultrasound imaging of the skin). All measurements were performed on the inner part of the left forearm.

RESULTS

The skin parameters measured revealed significant differences in skin surface and structure between females and males. The skin of all women subjects was more homogenous in its structure with the presence of more abundant superficial skin lines and wrinkles in comparison to male skin. The higher number of skin furrows in the skin of women is in agreement with literature reports claiming that men's skin has lower number of wrinkles which are deeper and more pronounced. Ultrasound imaging of the skin indicated greater thickness and lower density of the dermis of men subjects compared to those of females.

CONCLUSION

Non-invasive methods of skin testing using new and advanced equipment have provided a possibility of objective parametrization and evaluation of sex-related changes in skin topography and structure.

Genetic polymorphisms and expression of HLA-G and its receptors, KIR2DL4 and LILRB1, in non-small cell lung cancer

Human leukocyte antigen-G (HLA-G) is a nonclassical HLA class I molecule absent from most normal tissues but detected in many malignant tumors. It is recognized by cells of the immune system using LILRB1, KIR2DL4 and LILRB2 receptors. We attempted to find out whether some polymorphisms of HLA-G, LILRB1 and KIR2DL4 genes are associated with susceptibility to nonsmall cell lung cancer (NSCLC). Four polymorphisms in HLA-G, i.e. -964A>G (rs1632947), -725C>G>T (rs1233334), -716T>G (rs2249863) in the promoter, and a 14 base pair insertion/deletion (14 bp indel) in the 3'-untranslated region (3'UTR), and five in LILRB1 - 5651G>A (rs41308748) in intron 14, 5717C>T L622L (rs1061684), 5724G>A E625K (rs16985478), 5774 C>A P641P (rs41548213) in exon 15, and 5806C>T (rs8101240) in 3'UTR - as well as 9620 9A/10A (rs11410751) polymorphism in exon 7 of KIR2DL4 were typed using different laboratory techniques. Only one single nucleotide polymorphism (SNP) in HLA-G (-964A>G) and one in LILRB1 (5724G>A) were found to influence the risk of NSCLC. In addition, 5724G>A was associated with protection from tumor cell infiltration of regional lymph nodes. Most importantly, we detected HLA-G and LILRB1 expression in tumor specimens, but no correlation with genetic polymorphisms was observed. HLA-G and LILRB1 protein expression levels in tumor tissue were significantly correlated with tumor stage.

Genetic polymorphism of KIR2DL4 in the Polish population

The KIR2DL4 gene is characterized by alleles with either 9 or 10 consecutive adenines in exon 7, which encodes the transmembrane domain. The 9A variant produces either a protein with a truncated cytoplasmic tail or one lacking the transmembrane region. This causes a lack of KIR2DL4 expression. In contrast, 10A alleles encode receptors that may be expressed at the cell surface. We tested 438 healthy individuals for polymorphism of the KIR2DL4 gene. KIR2DL4 9A/10A alleles were distinguished by the high resolution melting (HRM) method, and restriction fragment length polymorphism (RFLP) was used for genotyping of three other single nucleotide polymorphisms (SNPs) spanning the near vicinity of the poly-adenine fragment. We found a weak difference between males and females in 9769 C/A genotypes and alleles. In addition, we observed complete linkage disequilibrium (LD) between 9A insertion/deletion in the 9620 position and the 9571T/C position of the gene (r(2)  = 1) both in females and males and almost complete LD with the 9797G/A position (r(2)  = 0.963 for females and r(2)  = 0.892 for males). Most importantly, we detected, in a group of fertile women, a high frequency (30.2%) of homozygosity for the defective 9A variant, which suggests that KIR2DL4 as a functional cell surface receptor is not absolutely necessary for reproduction. On the other hand, lower representation of 10A/10A homozygotes and high frequency of 10A/9A heterozygotes indicates a need for both cell membrane-anchored and soluble KIR2DL4 molecules. Finally, cost-reducing RFLP instead of HRM is proposed for typing 9A and 10A variants.

Lack of KIR2DL4 gene in a fertile Caucasian woman

Killer cell immunoglobulin-like receptor (KIR2DL4) gene is present in virtually all humans. It encodes a receptor present on uterine and decidual natural killer (NK) cells and some peripheral blood NK cells. Its only known ligand is human leukocyte antigen-G molecule expressed on extravillous trophoblasts invading the decidua. Therefore, KIR2DL4 has been regarded as a molecule important for successful pregnancy. However, a multiparous woman from Africa, lacking KIR2DL4 gene, was described suggesting that this gene is not absolutely required for successful human reproduction. Here, we describe a Polish woman who delivered a child and who is not only lacking KIR2DL4 gene, but also possessing a KIR genotype virtually identical to that of the African woman mentioned above. Their genotypes are compared with few other KIR2DL4-negative genotypes and haplotypes described so far.

The introduction of the SENTINEL influenza surveillance system in Poland - experiences and lessons learned from the first three epidemic seasons

Influenza surveillance provides information on virus activity and is necessary for the selection of vaccine strains and early warning in the case of the threat of an epidemic or pandemic. To improve this surveillance in Poland, a sentinel surveillance system was introduced in 2004-5 (""SENTINEL""). This paper presents results from SENTINEL during three seasons of its existence. Voivodship Sanitary-Epidemiological Stations (VSESs), physicians and the National Influenza Center (NIC) participate in SENTINEL. Laboratory course was performed by the NIC for VSESs. Stations were provided with procedures, report forms, etc. Physicians register number of influenza-like illnesses (ILI) and collect swabs. VSESs perform diagnostic tests. On the basis of information from VSESs, the NIC prepares weekly reports for the entire country. In 2004-5 epidemiological reports were received from 50% of VSESs, while in 2005-6 and 2006-7 from all VSESs. Virological reports were obtained from 37.5% of VSESs (2004-5), 75% (2005-6) and 94% (2006-7). Weekly number of reporting physicians ranged in three consecutive seasons from 165 to 219, 98 to 949 and 696 to 1,054. A total of 399 specimens were tested during the 2004-5 winter; 63 (16%) were positive for influenza and 21 (5%) for other respiratory viruses. In 2005-6, 949 specimens were tested. Influenza infections were confirmed in 47 cases (5%) and infections with other respiratory viruses in 36 cases (4%). A total of 1,195 specimens were tested during the 2006-7 winter; 37 (3%) were positive for influenza and 26 (2%) for other respiratory viruses. SENTINEL provided improvement of influenza surveillance when compared with seasons before 2004. Nevertheless, due to decreasing rate of positive specimens, virological surveillance is the most important part to improve in the next years.

The introduction of the SENTINEL influenza surveillance system in Poland--experiences and lessons learned from the first three epidemic seasons

Influenza surveillance provides information on virus activity and is necessary for the selection of vaccine strains and early warning. To improve this surveillance in Poland, a sentinel surveillance system was introduced in 2004-5 influenza season (SENTINEL). This paper presents results from SENTINEL during three seasons of its existence. Voivodship Sanitary-Epidemiological Stations (VSESs), physicians and the National Influenza Center (NIC) participate in SENTINEL. Laboratory course was performed by the NIC for VSESs. Stations were provided with procedures, report forms, etc. Physicians register number of influenza-like illnesses (ILI) and collect swabs. VSESs perform diagnostic tests. On the basis of information from VSESs, the NIC prepares weekly reports for the entire country. In 2004-5 epidemiological reports were received from 50% of VSESs, while in 2005-6 and 2006-7 from all VSESs. Virological reports were obtained from 37.5% of VSESs (2004-5), 75% (2005-6) and 94% (2006-7). Weekly number of reporting physicians ranged in three consecutive seasons from 165 to 219, 98 to 949 and 696 to 1,054. A total of 399 specimens were tested during the 2004-5 winter; 63 (16%) were positive for influenza and 21 (5%) for other respiratory viruses. In 2005-6, 949 specimens were tested. Influenza infections were confirmed in 47 cases (5%) and infections with other respiratory viruses in 36 cases (4%). A total of 1,195 specimens were tested during the 2006-7 winter; 37 (3%) were positive for influenza and 26 (2%) for other respiratory viruses. SENTINEL provided improvement of influenza surveillance when compared with seasons before 2004. Nevertheless, due to decreasing rate of positive specimens, virological surveillance is the most important part to improve in the next years.

Distribution of the CTLA-4 single nucleotide polymorphisms CT60G>A and +49A>G in psoriasis vulgaris patients and control individuals from a Polish Caucasian population

Psoriasis vulgaris is a multifactorial disease with an autoimmune component, and T lymphocytes seem to be involved in its aetiology. CTLA-4 molecule is an important down-regulator of T-lymphocyte activation, and several polymorphisms of the CTLA-4 gene were found to be associated with some autoimmune diseases. We examined whether single nucleotide polymorphisms (SNPs) in the CTLA-4 gene, CT60A>G and +49A>G, are associated with psoriasis vulgaris. Alleles of these two SNPs were determined by the polymerase chain reaction-restriction fragment length polymorphism method. Both the CT60G>A and the +49A>G alleles and genotypes were distributed similarly in patients and controls. Although the two SNPs studied here in Poles were in linkage disequilibrium, all four possible two-locus haplotypes were found, one of them rare; of the remaining three, the haplotype +49G, CT60G was significantly (P = 0.019, OR = 0.58, 95%CI = 0.37-0.91) less frequent in the patient group with disease onset between the ages of 21 and 40 years than in controls and the other patient groups, whereas the frequencies of the other haplotypes were similar in patients and controls. To the authors' knowledge, this is the first study on CTLA-4 CT60 allele frequencies in psoriasis.

Antibody response to inactivated subunit influenza vaccine in patients with Wegener's granulomatosis

In the present study we investigated the humoral response to inactivated subunit influenza vaccine in patients with Wegener's granulomatosis, who were in clinical and serological remission after immunosuppressive treatment (Group I). The results were compared with patients with Wegener's granulomatosis who were treated immunosuppressively, but were not vaccinated (Group II) and with healthy persons who received the vaccine (Group III). After vaccination, antihemagglutinin and antineuraminidase antibody titers significantly increased in Groups I and Group III subjects when compared with the pre-vaccination values. Post-vaccination protection rates ranged from 51.4% to 74.3% in Group I patients and from 65.7% to 94.3% in Group III subjects. In Group II, the protection rates were between 0% and 21.4%. The response rates ranged from 60% to 74.3% in Group I patients and from 71.4% to 88.6% in Group III subjects. In Group II, the response rates were between 7.1% and 21.4%. The study confirmed the immunogenicity of influenza vaccine in patients with Wegener's granulomatosis and showed similar response in the patients to those present in healthy people.

Antibody response to influenza vaccination in patients suffering from asthma

The aim of the study was to assess humoral response to influenza vaccination in 20 children with bronchial asthma vaccinated with split inactivated vaccine. Response to influenza hemagglutinin was assessed before vaccination and after 1 month by hemagglutination inhibition test. Antibody titers were significantly higher after vaccination than before vaccination. The mean fold increase of antibody levels ranged after vaccination from 12.2 to 53.7. The post-vaccination percentage of patients with protective antihemagglutinin antibody titers>or=40 ranged from 95% to 100%. The percentage of patients with at least a 4-fold increase of anthemagglutinin antibody titers ranged after vaccination from 90% to 100%. The results confirmed the immunogenicity and safety of inactivated influenza vaccine in children with asthma. The registered values of all parameters of the immunological response (mean fold increase, protection rate, response rate) fulfilled the requirements of the Committee for Proprietary Medicinal Products established for healthy people vaccinated against influenza.

Deoxygenative [1,2]-hydride shift rearrangements in nucleoside and sugar chemistry: analogy with the [1,2]-electron shift in the deoxygenation of ribonucleotides by ribonucleotide reductases

A variant of the semipinacol rearrangement that was observed in our laboratory has been applied to the synthesis of several furanose and pyranose derivatives. The process consists of an "orchestrated" [1,2]-hydride shift with departure of a leaving group from the opposite face. Transient formation of a C=O group is followed by rapid transfer of a hydride-equivalent from the same face from which the leaving group departed, which results in double inversion of stereochemistry at the two vicinal carbon atoms. Treatment of 2'-O- and 3'-O-tosyladenosine with lithium triethylborohydride in DMSO/THF gave the respective 2'- and 3'-deoxynucleoside analogues with beta-D-threo configurations. Identical treatment of 5'-O-TPS-2'-O-tosyladenosine gave 9-(5-O-TPS-2-deoxy-beta-D-threo-pentofuranosyl)adenine. The same [1,2]-hydride shift and stereochemistry with the 5'-OH and 5'-O-TPS compounds demonstrated the absence of remote hydroxyl-group participation. Application of this process to other nucleoside 2'-O-tosyl derivatives gave the 2'-deoxy-threo compounds in good yields. The reaction-rate order was OTs approximately Br >> Cl for 2'-O-tosyladenosine, 2'-bromo-2'-deoxyadenosine, and 2'-chloro-2'-deoxyadenosine (all with beta-d-ribo configurations). Analogous results were obtained with mannopyranoside derivatives with either 4,6-O-benzylidene protection or a free OH group at C4. Deuterium labeling clearly defined the stereochemical course as a cis-vicinal [1,2]-hydride shift on the face opposite to the original cis OH and OTs groups followed by hydride transfer from the face opposite to the [1,2]-hydride shift. Synthetic and mechanistic considerations are discussed.

Associations of killer cell immunoglobulin-like receptor genes with complications of rheumatoid arthritis

We investigated whether killer cell immunoglobulin-like receptor (KIR) genes are risk factor(s) for rheumatoid arthritis (RA) and its clinical manifestations. One hundred and seventy-seven RA patients and 243 healthy individuals were tested for the presence of 11 KIR genes using PCR-SSP method. The frequencies of KIRs in patients with RA were similar to the frequencies in controls. However, RA patients positive for KIR2DL3 and negative for KIR2DS3 had earlier disease diagnosis. Additionally, KIR2DL2 and KIR2DS2 were significantly more frequent among RA patients with extra-articular manifestations and in its subgroup with vasculitis than in controls and in patients without these complications. Furthermore, the frequencies of KIR2DS1 and KIR3DS1 were lower in patients without bone erosions compared with healthy individuals. Relationships between the presence or absence of autoantibodies (rheumatoid factor and anti-cyclic citrullinated peptide) and KIR frequencies were also evaluated, but no significant differences were observed. These results suggest that particular clinical manifestations of RA may have different genetic backgrounds with respect to KIR genotype.

Synthesis and Antiviral Evaluation of 6-(Alkyl-heteroaryl)furo[2,3-d]pyrimidin-2(3H)-one Nucleosides and Analogues with Ethynyl, Ethenyl, and Ethyl Spacers at C6 of the Furopyrimidine Core

Sonogashira coupling strategies were employed to synthesize new furo[2,3-d]pyrimidin-2(3H)-one (FuPyrm) 2'-deoxynucleoside analogues. Partial or complete reduction of ethyne-linked compounds afforded ethenyl- and ethyl-linked derivatives. Levels of inhibition of varicella-zoster virus (VZV), human cytomegalovirus (HCMV), a broad range of other DNA and RNA viruses, and several cancer cell lines were evaluated in cell cultures. The anti-VZV potency decreased with increasing rigidity of the side chain at C6 of the FuPyrm ring in the order dec-1-yn-1-yl < dec-1-en-1-yl < decan-1-yl. In contrast, compounds with a rigid ethynyl spacer between C6 of the FuPyrm ring and a 4-alkylphenyl moiety were more potent inhibitors of VZV than the corresponding derivatives with an ethyl spacer. Replacement of the phenyl moiety in 6-(4-alkylphenyl) derivatives with a pyridine ring (in either regioisomeric orientation) gave analogues with increased solubility in methanol but reduced anti-VZV potency, and replacement with a pyrimidine ring reduced the anti-VZV activity even further. The pyridine-ring-containing analogues were approximately 20-fold more potent inhibitors of VZV than acyclovir but were approximately 6-fold less potent than BVDU and approximately 60-fold weaker than the most active 6-(4-pentylphenyl)-substituted prototype.

Probing the membrane targeting C1 subdomains of PKC with bivalent ligands

Protein kinase C is a family of ubiquitously expressed signal transducing proteins. The hallmark for PKC activation is its translocation to membranes following generation of lipid second messengers. This process is mediated by C1 and C2 membrane-targeting modules, whose engagement on membranes provides energy for a conformational change crucial to PKC activity. Novel and conventional subfamilies of PKC have two C1 domains, namely C1A and C1B, each of which contain a binding pocket for a messenger. Several studies addressed the issue of simultaneous activation of both C1 domains by specifically designed bivalent activators based on phorbol esters, benzolactam and other PKC ligands. Many bivalent ligands displayed 1-2 orders of magnitude higher potency then their monovalent congeners. Most effective were the "dimeric" ligands linked with 10-14 carbon spacers. Lower than predicted potency and lack of marked isoform selectivity indicate that those compounds do not activate both C1 domains at the same time, or that process is unfavored due to steric or conformational reasons. However, high binding affinity for some of them provides hope that related PKC activators that are isoform selective can be developed. As to the nature of the linkers: flexible and lipophilic oligomethylene chains proved superior over flexible and hydrophilic oligoethylene glycol or rigid and lipophilic benzene in recruiting PKC to the membranes.

Synthesis of 3'-deoxynucleosides with 2-oxabicyclo[3.1.0]hexane sugar moieties: addition of difluorocarbene to a 3',4'-unsaturated uridine derivative and 1,2-dihydrofurans derived from D- and L-xylose1

Syntheses of 3'-deoxy analogues of adenosine, cytidine, and uridine with a 2,2-difluorocyclopropane ring fused at C3'-C4' are described. Treatment of a 2',5'-protected-3',4'-unsaturated derivative of uridine with difluorocarbene [generated from (CF3)2Hg and NaI] gave a diastereomeric mixture of the 3',4'-difluoromethylene compounds (alpha-L-arabino/beta-D-ribo, approximately 5:4). The limited stereoselectivity for addition at the beta face results from competitive steric hindrance by an allylic 4-methoxybenzyloxy group at C2' on the alpha face and a homoallylic nucleobase at C1' on the beta face. Protected uracil derivatives were converted into their cytosine counterparts via 4-(1,2,4-triazol-1-yl) intermediates. Treatment of 1,2-dihydrofurans derived from D- and L-xylose with difluorocarbene resulted in stereospecific addition at the beta face (anti to the 1,2-O-isopropylidene group on the alpha face). Glycosylations with activated enantiomeric sugar derivatives with the fused difluorocyclopropane ring on the beta face gave protected adenine nucleosides, whereas attempted glycosylation with an alpha-fused derivative gave multiple products. Removal of base- and sugar-protecting groups gave new difluoromethylene-bridged nucleoside analogues.

Trifluoromethylation of Alkenyl Bromides and Iodides (Including 5-Iodouracils) with (CF3)2Hgand Cu (“Trifluoromethylcopper”)1

Bromo- and iodoalkenes undergo trifluoromethylation efficiently in DMA with "CF3Cu" generated from (CF3)2Hg and Cu. Variable stereochemical inversion is observed with substrates having a gem-carbonyl group. Substrates having gem-hydrogen, -alkyl, or -alkenyl groups give products with stereochemical retention.

Addition of Difluorocarbene to 3‘,4‘-Unsaturated Nucleosides: Synthesis of 2‘-Deoxy Analogues with a 2-Oxabicyclo[3.1.0]hexane Framework1

Treatment of protected 2'-deoxy-3',4'-unsaturated nucleosides derived from adenosine and uridine with difluorocarbene [generated from bis(trifluoromethyl)mercury and sodium iodide] gave fused-ring 2,2-difluorocyclopropane compounds. Stereoselective alpha-face addition to the dihydrofuran ring resulted from hindrance by the protected beta-anomeric nucleobases. A protected uracil compound was converted smoothly into the cytosine derivative via a 4-(1,2,4-triazol-1-yl) intermediate. Removal of the protecting groups gave new difluorocyclopropane-fused nucleoside analogues. The solid-state conformation of the nearly planar furanosyl ring in the uracil compound had a shallow 2E pucker, and a more pronounced 1E conformation was present in the furanosyl ring of the cytosine derivative.

Addition of Difluorocarbene to 4‘,5‘-Unsaturated Nucleosides: Synthesis and Deoxygenation Reactions of Difluorospirocyclopropane Nucleosides1

Synthetic routes to 4'-(2,2-difluorospirocyclopropane) analogues of adenosine, cytidine, and uridine are described. Treatment of 2',3'-O-isopropylidene-4',5'-unsaturated compounds derived from adenosine and uridine with difluorocarbene (generated from PhHgCF3 and NaI) gave diastereomeric mixtures of the 2,2-difluorospirocyclopropane adducts. Stereoselectivity resulting from hindrance by the isopropylidene group favored addition at the beta face. Removal of base and sugar protecting groups gave new difluorospirocyclopropane nucleoside analogues. The protected uridine analogue was converted into its cytidine counterpart via a 4-(1,2,4-triazol-1-yl) intermediate. Stannyl radical-mediated deoxygenation of the 3'-O-TBS-2'-thionocarbamate derivatives gave the 2'-deoxy products of direct hydrogen transfer. In contrast, identical treatment of the 2'-O-TBS-3'-thionocarbamate isomers resulted in opening of the vicinal difluorocyclopropane ring upon generation of a C3' radical followed by homoallylic hydrogen transfer to give 4'-(1,1-difluoroethyl)-3',4'-unsaturated nucleoside derivatives. Structural aspects and biological effect considerations are discussed.

Regiospecific and Highly Stereoselective Coupling of 6-(Substituted-imidazol-1-yl)purines with 2-Deoxy-3,5-di-O-(p-toluoyl)-α-d-erythro-pentofuranosyl Chloride. Sodium-Salt Glycosylation in Binary Solvent Mixtures: Improved Synthesis of Cladribine1

Glycosylation of 6-(substituted-imidazol-1-yl)purine sodium salts with 2-deoxy-3,5-di-O-(p-toluoyl)-alpha-D-erythro-pentofuranosyl chloride proceeds with regiospecific formation of the N9 isomers. Base substrates with lipophilic substituents on the C6-linked imidazole moiety are more soluble in organic solvents, and the solubility is further increased with binary solvent mixtures. Selective solvation also diminishes the extent of anomerization of the chlorosugar. Stirred reaction mixtures of the modified-purine sodium salts generated in a polar solvent and cooled solutions of the protected 2-deoxysugar chloride in a nonpolar solvent give 2'-deoxynucleoside derivatives with N9 regiochemistry and enhanced beta/alpha configuration ratios. Application of the binary-solvent methodology with 2-chloro-6-(substituted-imidazol-1-yl)purine salts in cold acetonitrile and the chlorosugar in cold dichloromethane gives essentially quantitative yields of the N9 isomers of beta-anomeric 2'-deoxynucleoside intermediates. Direct ammonolysis (NH(3)/MeOH) of such intermediates or benzylation of the imidazole ring followed by milder ammonolysis of the imidazolium salt gives high yields of the clinical anticancer drug cladribine (2-chloro-2'-deoxyadenosine).

N-Oxides of Adenosine-Type Nucleosides Undergo Pyrimidine Ring Opening and Closure To Give 5-Amino-4-(1,2,4-oxadiazol-3-yl)imidazole Derivatives†

Treatment of acylated adenosine N-oxides with carboxylic anhydrides and thiophenol resulted in pyrimidine ring opening followed by exocyclic ring closure. Ammonolysis gave 5-amino-4-(5-substituted-1,2,4-oxadiazol-3-yl)-1-(beta-d-ribofuranosyl)imidazole derivatives, whereas iodine in methanol selectively unmasked the 5-amino group. Related flexible nucleoside analogues can be prepared from adenine-type precursors.

CTLA-4 gene polymorphisms and natural soluble CTLA-4 protein in psoriasis vulgaris

CTLA-4 molecule is an important inhibitor of T-lymphocyte activation. Several single nucleotide polymorphisms (SNPs) in the CTLA-4 gene were found, and their associations with many human diseases were described. So far, however, such studies have not been performed in psoriasis vulgaris in Caucasoids. Therefore, we examined the distribution of three CTLA-4 SNPs: -1147C/T, -318C/T and +49 A/G in 116 patients with psoriasis vulgaris and 123 healthy blood donors using the polymerase chain reaction-restriction fragment length polymorphism method. For all three SNPs, the frequencies of alleles, genotypes and three-point haplotypes were very similar in patients and controls, suggesting no contribution of these genetic variants to psoriasis.

Characterization of the transport mechanism and permeant binding profile of the uridine permease Fui1p of Saccharomyces cerevisiae

The uptake of Urd into the yeast Saccharomyces cerevisiae is mediated by Fui1p, a Urd-specific nucleoside transporter encoded by the FUI1 gene and a member of the yeast Fur permease family, which also includes the uracil, allantoin, and thiamine permeases. When Fui1p was produced in a double-permease knock-out strain (fur4Deltafui1Delta) of yeast, Urd uptake was stimulated at acidic pH and sensitive to the protonophore carbonyl cyanide m-chlorophenylhydrazone. Electrophysiological analysis of recombinant Fui1p produced in Xenopus oocytes demonstrated that Fui1p-mediated Urd uptake was dependent on proton cotransport with a 1:1 stoichiometry. Mutagenesis analysis of three charged amino acids (Glu(259), Lys(288), and Asp(474) in putative transmembrane segments 3, 4, and 7, respectively) revealed that only Lys(288) was required for maintaining high Urd transport efficiency. Analysis of binding energies between Fui1p and different Urd analogs indicated that Fuip1 interacted with C(3')-OH, C(2')-OH, C(5)-H, and N(3)-H of Urd. Fui1p-mediated transport of Urd was inhibited by analogs with modifications at C-5', but was not inhibited significantly by analogs with modifications at C-3', C-5, and N-3 or inversions of configuration at C-2' and C-3'. This characterization of Fui1p contributes to the emerging knowledge of the structure and function of the Fur family of permeases, including the Fui1p orthologs of pathogenic fungi.

Inhibitory and activatory KIR gene frequencies in the Polish population

Killer cell immunoglobulin-like receptors (KIRs) present on natural killer cells and minor subpopulations of T cells recognize class I human leukocyte antigen (HLA) molecules on the surface of target cells. Human individuals differ by the presence or absence of some KIR genes on their chromosomes (haplotypic polymorphism). As KIRs (especially two-immunoglobulin-domain-like containing, or KIR2D, molecules) are important for the outcome of tissue (particularly for haematopoietic stem cell) transplantation and possibly for pregnancy, the knowledge of KIR gene distribution in a given human population is of practical value. Therefore, we tested 175 healthy individuals from Poland for the presence or absence of these KIR genes which show haplotypic polymorphism and are expressed. Results were compared with those published for other human populations, showing close relations with other Caucasoids.

Nucleic acid related compounds. 127. Selective N-deacylation of N,O-peracylated nucleosides in superheated methanol

[reaction: see text] Solutions of peracylated adenosine, cytidine, and related nucleoside derivatives undergo selective N-deacylation upon heating at elevated temperatures (oil bath > or = 105 degrees C) in methanol. An increase in the bulk of the N-acyl group has little effect on the rate of N-deacylation but increases the N/O selectivity ratio. Extended heating is required for N-deacylation with arylcarboxylic acid derivatives. Contamination with acidic or basic reagent residues is avoided.

Structure and Synthesis of 6-(Substituted-imidazol-1-yl)purines: Versatile Substrates for Regiospecific Alkylation and Glycosylation at N91

X-ray crystal structures of several 6-(azolyl)purine base and nucleoside derivatives show essentially coplanar conformations of the purine and appended 6-(azolyl) rings. However, the planes of the purine and imidazole rings are twisted approximately 57 degrees in a 2-chloro-6-(4,5-diphenylimidazol-1-yl)purine nucleoside, and a twist angle of approximately 61 degrees was measured between the planes of the purine and pyrrole rings in the structure of a 6-(2,5-dimethylpyrrol-1-yl)purine nucleoside derivative. Shielding "above" N7 of the purine ring by a proximal C-H on the 6-azolyl moiety is apparent with the coplanar compounds, but this effect is diminished in those without coplanarity. Syntheses of 6-(azolyl)purines from both base and nucleoside starting materials are described. Treatment of 2,6-dichloropurine with imidazole gave 2-chloro-6-(imidazol-1-yl)purine. Modified Appel reactions at C6 of trityl-protected hypoxanthine and guanine derivatives followed by detritylation gave 6-(imidazol-1-yl)- and 2-amino-6-(imidazol-1-yl)purines. Imidazole was introduced at C6 of 2',3',5'-tri-O-acetylinosine by a modified Appel reaction, and solvolysis of the glycosyl linkage gave 6-(imidazol-1-yl)purine. Guanosine triacetate was transformed into the protected 2,6-dichloropurine nucleoside, which was subjected to S(N)Ar displacement with imidazoles at C6 followed by glycosyl solvolysis to provide 2-chloro-6-(substituted-imidazol-1-yl)purines. Potential applications of these purine derivatives are outlined.

Selective removal of the 2'- and 3'-O-acyl groups from 2',3',5'-tri-O-acylribonucleoside derivatives with lithium trifluoroethoxide

Selective cleavage of O2' and O3' ester groups from ribonucleoside derivatives has been accomplished with Dowex 1 x 2 (CF3CH2O-) in 2,2,2-trifluoroethanol (TFE) or lithium trifluoroethoxide/TFE. Deacylations with Li+ -OCH2CF3/TFE proceed at ambient temperature (or with mild heating) to give the 5'-O-acyl derivatives in superior yields and higher purity than prior approaches for selective O2' and O3' ester deprotection.