Synthesis and biological activity of thiophene bioisosteres of natural styryl lactone goniofufurone and related compounds.

Ten new thiophene derivatives related to goniofufurone have been obtained by multistep synthesis starting from d-glucose. The critical step of the synthesis was the Grignard reaction of 2-thienyl magnesium bromide with a protected dialdose, yielding the C-5 epimeric thiophene derivatives 9 and 10. The mixture was oxidized to the 5-keto derivative 11, which after deprotection was converted to the corresponding keto-lactone 14. Stereoselective reduction of 14 afforded the thiophene mimic of goniofufurone 3. Esterification of 3 with cinnamic or 4-fluorocinnamic acid gave hybrids 5-7. Synthesized analogues were evaluated for their in vitro cytotoxicity against several tumour cell lines. The vast majority of them showed better activity than lead 1. In the culture of K562 cells, compound 3 was more active than the commercial antitumour drug doxorubicin. Structural features of analogues important for their antiproliferative activities were identified by SAR analysis. Pro-apoptotic potential examination of compound 3 on the K562 cell line was performed using flow cytometry, double fluorescence staining and apoptotic morphology screening. Results show that this derivative induces cell membrane disruptions attributable to apoptosis and induces the apoptotic morphology, but decreasing simultaneously the population of cells in the subG1 phase of the cell cycle. The results further suggest that analogue 3 achieves strong cytotoxicity without causing DNA fragmentation. This is clearly indicated by the relatively low incidence of micronuclei, as well as the SAR analysis of all biological effects.

Roadmap to improve the organized cancer screening programs - The case of colorectal cancer screening in Montenegro.

BACKGROUND: Implementation of organized cancer screening programs comes with many challenges and barriers, which may inhibit the achievement of the screening activities' desired benefits. In this paper we outline a plan for improving the colorectal cancer (CRC) screening system in Montenegro. METHODS: We formulated a roadmap, which was generally defined as a country-specific strategic plan to improve cancer screening programs. The roadmap development was an iterative, step-by-step process. First, we described the current screening program, then identified and described key barriers, and finally proposed actions to overcome them. Multiple sources of information (e.g., documents, expert opinions) were collected and processed by local and international stakeholders. RESULTS: The CRC screening program was implemented between 2013-2019 by gradually increasing the invitation of the target population. Key barriers of the implementation were defined: 1) Lack of colonoscopy capacity in the northern part of the country; 2) Inadequate information technology systems; 3) Inadequate public promotion of screening. The defined actions were related to overcoming lack of available resources (e.g., financial, human and technological), to improve the policy environment and the knowledge, and to facilitate information sharing. CONCLUSION: The collaboration between local stakeholders of CRC screening and researchers experienced in planning and evaluating screening programs resulted in the first comprehensive description of CRC screening in Montenegro, detailed understanding of key barriers that emerged during implementation and a carefully designed list of actions. The implementation of these actions and the evaluation of whether barriers were solved will be captured in the upcoming period by maintaining this collaboration.

The first total synthesis and revision of absolute stereochemistry of natural cytotoxic lactone cleistanolate.

Development of a synthetic route applicable to d-ribose and d-xylose enabled the synthesis of cleistanolate putative structure, its five stereoisomers, and led to revision and confirmation of absolute stereochemistry of the natural product. Key steps of the synthesis included zinc-mediated THF ring-opening and stereoselective dihydroxylation under the Upjohn conditions. The first total synthesis of cleistanolate was completed in eight steps starting from d-xylose. The C-5 stereocenter of the natural product was assigned the correct (5S)-stereochemistry. Cytotoxicity of natural product was briefly investigated.

Practical Synthesis and Application of Halogen-Doped Pyrrole Building Blocks.

A practical access to four new halogen-substituted pyrrole building blocks was realized in two to five synthetic steps from commercially available starting materials. The target compounds were prepared on a 50 mg to 1 g scale, and their conversion to nanomolar inhibitors of bacterial DNA gyrase B was demonstrated for three of the prepared building blocks to showcase the usefulness of such chemical motifs in medicinal chemistry.

Health-BlockEdge: Blockchain-Edge Framework for Reliable Low-Latency Digital Healthcare Applications.

The rapid evolution of technology allows the healthcare sector to adopt intelligent, context-aware, secure, and ubiquitous healthcare services. Together with the global trend of an aging population, it has become highly important to propose value-creating, yet cost-efficient digital solutions for healthcare systems. These solutions should provide effective means of healthcare services in both the hospital and home care scenarios. In this paper, we focused on the latter case, where the goal was to provide easy-to-use, reliable, and secure remote monitoring and aid for elderly persons at their home. We proposed a framework to integrate the capabilities of edge computing and blockchain technology to address some of the key requirements of smart remote healthcare systems, such as long operating times, low cost, resilience to network problems, security, and trust in highly dynamic network conditions. In order to assess the feasibility of our approach, we evaluated the performance of our framework in terms of latency, power consumption, network utilization, and computational load, compared to a scenario where no blockchain was used.

Post-Flood Impacts on Occurrence and Distribution of Mycotoxin-Producing Aspergilli from the Sections Circumdati, Flavi, and Nigri in Indoor Environment.

Mycotoxin-producing Aspergilli (Circumdati, Flavi, and Nigri), usually associated with contaminated food, may also cause respiratory disorders and are insufficiently studied in water-damaged indoor environments. Airborne (N = 71) and dust borne (N = 76) Aspergilli collected at post-flood and control locations in Croatia resulted in eleven different species based on their calmodulin marker: A. ochraceus, A. ostianus, A. pallidofulvus, A. sclerotiorum, and A. westerdijkiae (Circumdati); A. flavus (Flavi); and A. tubingensis, A. welwitschiae, A. niger, A. piperis, and A. uvarum (Nigri). Most of the airborne (73%) and dust borne (54%) isolates were found at post-flood locations, and the highest concentrations measured in indoor air (5720 colony-forming units (CFU)/m3) and dust (2.5 × 105 CFU/g) were up to twenty times higher than in the control locations. A. flavus dominated among airborne isolates (25%) at the unrepaired locations, while 56% of the dust borne Aspergilli were identified as A. tubingensis and A. welwitschiae. The ability of identified isolates to produce mycotoxins aflatoxin B1 (AFB1), fumonisin B2 (FB2), and ochratoxin A were assessed by LC-MS analysis. All ochratoxin A (OTA)-producing Circumdati belonged to A. westerdijkiae (13.7 ± 15.81 µg/mL); in the section, FlaviA. flavus produced AFB1 (2.51 ± 5.31 µg/mL), while A. welwitschiae and A. niger (section Nigri) produced FB2 (6.76 ± 13.51 µg/mL and 11.24 ± 18.30 µg/mL, respectively). Water damage dominantly supported the occurrence of aflatoxigenic A. flavus in indoor environments. Yet unresolved, the causal relationship of exposure to indoor Aspergilli and adverse health effects may support the significance of this research.

Synthesis, antiproliferative activity and SAR analysis of (-)-cleistenolide and analogues.

A new, modified total synthesis of (-)-cleistenolide (1) and sixteen new analogues or derivatives was achieved starting from commercially available 1,2-O-isopropylidene-α-d-glucofuranose. The synthesis of 1 proceeds in six steps and 67% overall yield, using single-carbon atom degradation of a protected chiral precursor, (Z)-selective Wittig olefination, and acid catalyzed δ-lactonization. A new Lewis acid promoted procedure for one-pot O-debenzylation/O-acylation has been developed to complete the synthesis of natural product 1 and selected analogues. The synthesized compounds were tested in vitro to evaluate their cytotoxicity against K562, HL-60, Jurkat, Raji, MCF-7, MDA-MB 231, HeLa, A549, and MRC-5 cell lines. All (-)-cleistenolide analogues exhibited significantly higher cytotoxicity than lead 1 against the majority of cell lines tested. Most of the synthesized compounds are more active than doxorubicin on at least one malignant cell line, but were almost completely inactive against normal MRC-5 cells. The structural features of the tested compounds responsible for their antiproliferative activity have been identified by preliminary SAR analysis.

Structure based design, synthesis and in vitro antitumour activity of tiazofurin stereoisomers with nitrogen functions at the C-2' or C-3' positions.

Three novel tiazofurin analogues having d-arabino stereochemistry and nitrogen functionalities at the C-2' position (5-7) have been designed and synthesized in multistep sequences, starting from d-glucose. The known d-xylo stereoisomer of 1 (compound 2) along with two new analogues bearing nitrogen functions at the C-3' (3 and 4) has also been synthesized from the same sugar precursor. The synthetic sequence consisted of the following three stages: (i) the multistep synthesis of suitably protected pentofuranosyl cyanides, (ii) the construction of ethyl thiazole-4-carboxylate part by cyclocondensation of thus obtained glycofuranosyl cyanides with l-cysteine ethyl ester followed by dehydrogenation, and (iii) the final transformation of the ethyl thiazole-4-carboxylates into the target tiazofurin analogues using the esters ammonolysis. The tiazofurin analogues were evaluated for their antitumour activities in cell-culture-based assays. Compounds 3, 4 (d-xylo) and 7 (d-arabino), showed remarkable antitumour activities, with IC50 values in the range of 4-7 nM. Preliminary structure-activity relationship allowed identification of two analogues with antiproliferative activities exceeding that of the parent compound 1 for several orders of magnitude (e.g. 4: 1354-fold against Raji, 7: 309-fold against K562). Flow cytometry data and Western blot analysis suggested that cytotoxic effects of d-xylo stereoisomers in the culture of K562 cells caused changes in the cell cycle distribution, as well as the induction of apoptosis in caspase-dependent way. The increase of apoptotic cells percentage in treated samples is also confirmed with fluorescent double-staining method. Genotoxicity testing showed that the analogues with the xylo-configuration (2-4) are far less genotoxic than tiazofurin.

Genetic Profiling and Comparison of Human and Animal Methicillin-Resistant Staphylococcus aureus (MRSA) Isolates from Serbia.

The aim of this study was to characterize a collection of methicillin-resistant Staphylococcus aureus (MRSA) isolates of human and animal origin from Serbia. In total, 36 MRSA isolates-30 obtained from humans and six from companion animals-were investigated by PCR for the presence of antibiotic and biocide resistance determinants and virulence genes (PVL-Panton⁻Valentine leukocidin, ETs-exfoliative toxins, TSST-toxic shock syndrome toxin, SEs-staphylococcal enterotoxins, and MSCRAMMs-microbial surface components recognizing adhesive matrix molecules and biofilm). Isolates were analyzed by staphylococcal cassette chromosome mec (SCCmec), spa, and dru typing, as well as by multiple locus variable number of tandem repeat analyses (MLVA), multilocus sequence typing (MLST), and subsequently, eBURST. The majority of human MRSA isolates were resistant to gentamicin, erythromycin, clindamycin, and ciprofloxacin. Different antibiotic resistance genes were detected: aac-aphD, ant(6')-Ia, erm(A), erm(B), erm(C), tet(K), tet(M), fexA, and catpC221. All isolates were susceptible to teicoplanin and linezolid. SCCmec type III was prevalent in human isolates, while SCCmec elements in animals were mostly nontypeable. t037 was the predominant spa type in human and t242 in animal MRSA isolates. The prevalent dru type was dt11c in human and dt10a in animal MRSA isolates. MRSA isolates exhibited 27 different MLVA types. ST239 was predominant in human, while ST5 was prevalent in canine MRSA isolates. PVL was found in two, while tsst-1 was detected in three human isolates. Human-associated clones belonging to ST5, ST45, and ST239 MRSA clones were discovered in companion animals, which suggests anthropozoonotic transmission.

A comparative study of chromatographic behavior and lipophilicity of selected natural styryl lactones, their derivatives and analogues.

This study is based on the analyses of the retention behavior of selected natural styryl lactones and their synthetic analogues in reversed-phase high-performance liquid chromatography. Chromatographic separations were achieved applying ZORBAX SB-C18 column and two different mobile phases: methanol-water and acetonitrile-water. Chromatographic lipophilicity of the analyzed compounds was defined by logk0 constant and correlated with in silico molecular descriptors. According to the statistical validation parameters, obtained results indicate that the presented linear and multiple quantitative structure-retention relationship models can successfully predict the chromatographic lipophilicity of structurally similar compounds. Hierarchical cluster analyses (HCA) was applied in order to group similar compounds according to their chromatographic and in silico lipophilicity. It can be concluded that chromatographic systems with methanol-water were better for modelling of logk0. Modelling was performed in order to characterize compounds regarding their lipophilicity profiles as future drug candidates.

Synthesis and in vitro antitumour activity of crassalactone D, its stereoisomers and novel cinnamic ester derivatives.

Naturally occurring styryl lactone, crassalactone D (1), unnatural 4-epi-crassalactone D (2), and the corresponding 7-epimers (3 and 4) have been synthesized starting from d-glucose. The key step of the synthesis is a new one-pot sequence that commenced with a Z-selective Wittig olefination of suitably functionalized sugar lactols with a stabilized ylide, (methoxycarbonylmethylene)-triphenylphosphorane, in dry methanol, to afford 1 or 3, in the mixtures with the corresponding 4-epimers (2 or 4, respectively). A number of 6-O-cinnamoyl derivatives of styryl lactones 1-4 have been prepared, bearing electron donating or electron withdrawing functionalities in the C-4 position of cinnamic acid residue. The synthesized products were evaluated for their in vitro antiproliferative activity against selected human tumour cell lines, whereupon very potent cytotoxicities have been recorded in many cases. SAR analysis indicated some important structural features responsible for biological activity, such as stereochemistry at the C-4 and C-7 positions, as well as the nature of a substituent at the C-4 position in the aromatic ring of cinnamoate moiety. Flow cytometry and Western blot analysis data gave insight in the mechanism underlying antiproliferative effects of the synthesized compounds.

Design, synthesis and in vitro antitumour activity of new goniofufurone and 7-epi-goniofufurone mimics with halogen or azido groups at the C-7 position.

A series of new antitumour lactones containing the [3.3.0] bicyclic furano-lactone core and the halogen or azido group at the C-7 position have been designed, synthesized, and evaluated for their in vitro antitumour activity against a panel of human tumour cell lines. Some of the analogues displayed powerful antiproliferative effects to certain human tumour cells, but all of them were devoid of any cytotoxicity towards the normal foetal lung fibroblasts (MRC-5). A SAR study reveals the structural features of these lactones that may affect their antiproliferative activity. These are: the nature of substituent present at the C-7 position, stereochemistry at the C-7 position, the absence of phenyl group at the C-7 position. Flow cytometry data indicate that the cytotoxic effects of the synthesized analogues in a culture of K562 cells are mediated by apoptosis, additionally revealing that these molecules induced changes in cell cycle distribution of these cells. Results of Western blot analysis suggested that the most of synthesized compounds induce apoptosis in K562 cells in caspase-dependent way.

Robust adaptive filtering using recursive weighted least squares with combined scale and variable forgetting factors.

In this paper, a new adaptive robustified filter algorithm of recursive weighted least squares with combined scale and variable forgetting factors for time-varying parameters estimation in non-stationary and impulsive noise environments has been proposed. To reduce the effect of impulsive noise, whether this situation is stationary or not, the proposed adaptive robustified approach extends the concept of approximate maximum likelihood robust estimation, the so-called M robust estimation, to the estimation of both filter parameters and noise variance simultaneously. The application of variable forgetting factor, calculated adaptively with respect to the robustified prediction error criterion, provides the estimation of time-varying filter parameters under a stochastic environment with possible impulsive noise. The feasibility of the proposed approach is analysed in a system identification scenario using finite impulse response (FIR) filter applications.

New antitumour agents with α,ß-unsaturated δ-lactone scaffold: Synthesis and antiproliferative activity of (-)-cleistenolide and analogues.

A stereoselective total synthesis of (-)-cleistenolide (1) from d-glucose has been achieved. This new approach for the synthesis of (-)-cleistenolide and analogues involves a one-C-atom degradation of the chiral precursor, (Z)-selective Wittig olefination, followed by the final δ-lactonisation. Synthesized compounds showed potent growth inhibitory effects against selected human tumour cell lines, especially 2,4,6-trichlorobenzoyl derivative 12, which in the culture of MDA-MB 231 cells displayed the highest activity (IC50 0.02µM) of all compounds under evaluation. A preliminary SAR study reveals the structural features that are beneficial for antiproliferative activity of synthesized δ-lactones, such as presence of either electron-withdrawing or electron-donating substituents in the aromatic ring, as well as the presence of cinnamoyl functionality instead of benzoyl group at the O-7 position.

Synthesis and antiproliferative activity of goniobutenolides A and B, 5-halogenated crassalactone D derivatives and the corresponding 7-epimers.

A new synthesis of goniobutenolides A (1) and B (2) and the corresponding 7-epimers has been achieved starting from diacetone d-glucose. The key step of the synthesis is a new one-pot sequence that commenced with Z-selective Wittig (or Horner-Wadsworth-Emmons) olefination, followed by successive γ-lactonisation and ß-elimination. The above-mentioned unsaturated lactones were then converted to the corresponding 5-halogenated crassalactone D derivatives by using the appropriate haloetherification protocol. The most of synthesized compounds exhibited potent cytotoxic activities against a panel of tumour cell lines. The main structural features responsible for their antitumour potency have been revealed by means of SAR analysis. Flow cytometry data suggested that cytotoxic effects of these compounds in the culture of K562 cells might be mediated by apoptosis, additionally revealing that these molecules induced changes in cell cycle distribution of these cells. Results of semi-quantitative Western blot analysis indicate that the most of synthesized compounds induce apoptosis in a caspase-dependent manner.

The effects of industrial noise of higher spectrum on the workers' auditory perception abilities.

Background/Aim: Results of previous studies gave support to the idea that machines in power plants produce noise of different levels of loudness and frequency, and that it could cause deterioration of the hearing ability of workers. As a matter of fact, noiseinduced hearing loss is the most widespread occupational disease nowadays. As noise is a complex acoustic phenomenon, more factors have to be considered when studying it, such as frequency, intensity and the period of exposure. The aim of this study was to find if there are differences in the absolute threshold of hearing between workers in the factory production lines that are constantly exposed to the industrial noise of higher spectrum and those exposed to the noise of standard spectrum at different frequencies of sound. Methods: In the research plan, there were 308 workers employed in the production line of the Factory "Knjaz Milos", Arandelovac. A total of 205 of them were working in the conditions of higher spectrum noise (4,000 Hz ­ 8,000 Hz) and 103 workers were exposed to standard noise spectrum (31.5 Hz ­ 2,000.0 Hz). The objective measures of noise (frequency and amplitude) were acquired by phonometer, and measures of absolute threshold of hearing for both ears were obtained by audiometer by exposure to nine sound frequency levels. Data were statistically analyzed by establishing the significance of differences between absolute thresholds of hearing for both groups and for all nine frequency levels. Results: It was found that the absolute threshold of hearing is significantly higher for the group exposed to highfrequency noise at the 4,000 Hz and 8,000 Hz levels of frequency. Conclusion: Reduction of hearing sensitivity is evident for those exposed to higher spectrum noise, which is particularly evident at the higher frequency levels. Employees are often unaware of its effects because they are the results of prolonged exposure. Therefore, working in those conditions requires preventive measures and regular testing of the hearing ability.

[Pathophysiology of osteoporosis]. / Patofiziologija osteoporoze.

The balance of degradation and bone formation is important for the normal process of remodeling and maintenance of bone mass. Genetic, hormonal, immunological and other factors affect bone remodeling throughout life. Disorder of bone turnover plays key role in the pathophysiology of osteoporosis and presents a complex process which involves bone cells, cytokines and their receptors. Nowadays, important role of RANK/RANKL/OPG system in the pathophysiology of osteoporosis is well known, but it is still important to investigate the intracellular signaling pathways in the development of osteoporosis and other metabolic bone diseases.

Design, synthesis and SAR analysis of antitumour styryl lactones related to (+)-crassalactones B and C.

A series of styryl lactones containing the cinnamic acid ester groups such as (+)-crassalactones B (3a) and C (4a), 5,7-di-O-cinamoyl derivative 6, the corresponding 7-epimers and 7-deoxy derivatives have been synthesized, characterized and evaluated for their in vitro antitumour activity against a panel of several human tumour cell lines. Twelve new analogues such as 5-O- or 7-O-(4-methoxycinnamoyl), 5-O- or 7-O-(4-nitrocinnamoyl) and 5-O- or 7-O-(4-fluorocinnamoyl) esters of (+)-goniofufurone (3b-d), 7-epi-(+)-goniofufurone (epi-3b-d), as well as 7-deoxy derivatives 5b-d have been prepared to correlate all compounds in a SAR study. Some of the analogues displayed powerful antiproliferative effects on selected human tumour cell lines, but none of them demonstrated cytotoxicity towards the normal foetal lung fibroblasts (MRC-5). Thus, for the 7-epi-crassalactone B (epi-3a) was found to be a potent inhibitor of HL-60 cells growth, with an IC50 value that is approximately 46-fold lower than that observed for the commercial antitumour drug doxorubicin in the culture of the same cells. A SAR analysis performed on these lactones reveals the main structural features that affect their antiproliferative activity, such as nature of the substituents at the C-4 in the aromatic rings of cinnamoyl moieties, the absolute stereochemistry, as well as the presence of a deoxy function at the C-7 position.

Conformationally constrained goniofufurone mimics as inhibitors of tumour cells growth: Design, synthesis and SAR study.

Synthesis of conformationally restricted (+)-goniofufurone (1) and 7-epi-(+)-goniofufurone (2) analogues, with embedded O-isopropylidene, O-methylidene or cyclic carbonate functions is disclosed starting from d-glucose. A number of potential bioisosteres of 1 and 2 bearing both 5,7-O-methylidene and 4-substituted cinnamoyloxy functions at the C-7 position have also been synthesized. In vitro cytotoxicity of target molecules against a number of human tumour cell lines were recorded and compared with those observed for the parent molecules 1 and 2. Some of the analogues displayed powerful antiproliferative effects on selected human tumour cell lines, but all of them were devoid of any cytotoxicity towards the normal foetal lung fibroblasts (MRC-5). A SAR study reveals the structural features of these lactones that may increase their antiproliferative activity.

Vagus nerve stimulation in Lafora body disease.

INTRODUCTION: Lafora body disease (LBD) is a rare autosomal recessive disorder characterized by progression to inexorable dementia and frequent occipital seizures, in addition to myoclonus and generalized tonic-clonic seizures (GTCSs). It belongs to the group of progressive myoclonus epilepsies (PMEs), rare inherited neurodegenerative diseases with great clinical and genetic differences, as well as poor prognosis. Since those patients have a pharmacoresistant disease, an adjunctive treatment option is vagus nerve stimulation (VNS). To date, there are four reported cases of the utility of VNS in PME - in Unverricht-Lundborg disease (ULD), myoclonic epilepsy with ragged-red fibers (MERRF), Gaucher's disease, and in one case that remained unclassified. CASE PRESENTATION: A 19-year-old male patient had progressive myoclonus, GTCSs that often progressed to status epilepticus (SE), progressive cerebellar and extrapyramidal symptomatology, and dementia, and his disease was pharmacoresistant. We confirmed the diagnosis of LBD by genetic testing. After VNS implantation, in the one-year follow-up period, there was a complete reduction of GTCS and SE, significant regression of myoclonus, and moderate regression of cerebellar symptomatology. CONCLUSION: To our knowledge, this is the first reported case of the utility of VNS in LBD. Vagus nerve stimulation therapy may be considered a treatment option for different clinical entities of PME. Further studies with a larger number of patients are needed.