Development of structurally extended benzosiloxaboroles - synthesis and in vitro biological evaluation

The synthesis of potassium 6-hydroxy-7-chloro-1,1-dimethyl-3,3-difluorobenzo-1,2,3-siloxaborolate 5b from readily available 4-bromo-2-chlorophenol was developed. This compound proved useful in various derivatizations resulting in a wide range of O-functionalized benzosiloxaboroles. Reactions of 5b with selected substituted benzoyl chlorides gave rise to a series of respective derivatives with 6-benzoate side groups attached to the benzosiloxaborole core. Furthermore, treatment of 5b with substituted benzenesufonyl chlorides afforded several benzosiloxaboroles bearing functionalized benzenesulfonate moieties at the 6 position. The synthesis of related chloropyridine-2-yloxy substituted benzosiloxaboroles was accomplished by a standard approach involving silylation/boronation of appropriate heterodiaryl ethers. Investigation of biological activity of obtained compounds revealed that some benzoate and most benzenesulfonate derivatives exhibit high activity against Gram-positive cocci such as methicillin-sensitive Staphylococcus aureus ATCC 6538P as well as methicillin-resistant S. aureus ATCC 43300 with the MIC values in the range of 0.39–3.12 mg L⁻¹. Some benzenesulfonate derivatives showed also potent activity against Enterococcus faecalis ATCC 29212 and E. faecium ATCC 6057 with MIC = 6.25 mg L⁻¹. Importantly, for the most promising cocci-active benzenesulfonate derivatives the obtained MIC values were far below the cytotoxicity limit determined with respect to human normal lung fibroblasts (MRC-5). For those derivatives, the obtained IC₅₀ values were higher than 12.3 mg L⁻¹. The results of antimicrobial activity and cytotoxicity indicate that the tested compounds can be considered as potential antibacterial agents.

The synthesis of potassium 6-hydroxy-7-chloro-1,1-dimethyl-3,3-difluorobenzo-1,2,3-siloxaborolate 5b from readily available 4-bromo-2-chlorophenol was developed.

Identification of C-terminal hydrophobic residues important for dimerization and all known functions of ParB of Pseudomonas aeruginosa

The ParB protein of Pseudomonas aeruginosa is important for growth, cell division, nucleoid segregation and different types of motility. To further understand its function we have demonstrated a vital role of the hydrophobic residues in the C terminus of ParB(P.a.). By in silico modelling of the C-terminal domain (amino acids 242-290) the hydrophobic residues L282, V285 and I289 (but not L286) are engaged in leucine-zipper-like structure formation, whereas the charged residues R290 and Q266 are implicated in forming a salt bridge involved in protein stabilization. Five parB mutant alleles were constructed and their functionality was defined in vivo and in vitro. In agreement with model predictions, the substitution L286A had no effect on mutant protein activities. Two ParBs with single substitutions L282A or V285A and deletions of two or seven C-terminal amino acids were impaired in both dimerization and DNA binding and were not able to silence genes adjacent to parS, suggesting that dimerization through the C terminus is a prerequisite for spreading on DNA. The defect in dimerization also correlated with loss of ability to interact with partner protein ParA. Reverse genetics demonstrated that a parB mutant producing ParB lacking the two C-terminal amino acids as well as mutants producing ParB with single substitution L282A or V285A had defects similar to those of a parB null mutant. Thus so far all the properties of ParB seem to depend on dimerization.

Infections caused by RSV among children and adults during two epidemic seasons

Respiratory Syncytial Virus (RSV) is one of the most common causes of lower respiratory tract infections in young children, immunocompromised patients (children and adults), patients with chronic respiratory diseases and elderly people. Reinfections occur throughout the life, but the severity of disease decreased with subsequent infection. The aim of this study was to analyze the frequency of RSV infections in two selected subpopulations: young children (below 5 y.) and adults with chronic respiratory diseases (25-87 y.). Nasopharyngeal swabs (334) collected from October 2008 to March 2010 were examined. The presence of RSV genome was determined by RT-PCR and the presence of RSV antigen by quick immunochromatographic test. Positive results of RT-PCR were found in 45.2% of all swabs: 48.6% samples in 2008; 41.5% in 2009; 50.8% in 2010. The highest frequency of RSV-positive samples was in fall-winter months, but differences in RSV epidemic seasons were found. In the first season (2008-2009) an increased number of RSV infections was observed from November 2008, but in the second season--from January 2010. Generally, the frequency of RSV-positive RT-PCR among children was 53%, among adults 25%. The highest difference was observed in the first three-month period of 2010. RT-PCR positive samples were found in 68.5% of children and 5.9% of adults. However, the RSV antigen was found in 44.4% of samples collected from adults in this period. Our results indicate that the contribution of RSV infections during epidemic season of respiratory tract infections in Poland was really high among children and adults.

Detection of hMPV antigen by EIA in clinical specimens

Human Metapneumovirus (hMPV) is one of the latest discovered viruses. It has been classified to Paramyxoviridae family. It is the second viral etiological agent, after RSV, which causes respiratory tract infections (RTI) in children, especially children below 5 years old. It is estimated that 5-25% of RTI in children is due to hMPV. In adults hMPV reinfections are bounded to upper respiratory tract infections. The aim of the study was to establish usefulness of ELISA test in detecting hMPV antigen and to analyze hMPV infection in connection to clinical diagnosis.

MATERIAL/METHODS

273 nasopharyngeal swabs from children (189 swabs) and adults (84 swabs) with respiratory tract infections collected from 2008 to 2010 were examined. Due to similarity of hMPV and RSV viruses and overlapping of their epidemic season rapid immunochromatographic test for RSV antigen detection was also performed in case of 120 samples, hMPV antigen was detected in 24.5% of all swabs (n = 67): in 0.0% probes in 2008, 29.0% in 2009 and 36.8% in first quarter of 2010. The highest rate ofhMPV infection was detected from summer of 2009 till the end of March 2010 (VIII-IX 2009 - 62.5%, X-XII 2009 - 44.1% and I-III 2010 -36.8%). We analyzed respiratory tract diseases reported in patients with hMPV infection. Infection due to hMPV was found in 26.5% of children and 24.0% of adults with recognized pneumonia, respectively in 28.4 and 17.6% of patients with bronchitis. Bronchiolitis was diagnosed in two children with hMPV. RSV and hMPV coinfections were confirmed in 15 out of 120 examined probes. Cross reaction pattern was excluded thanks to ELISA hMPV antigen test which was performed with suspension of RSV and thanks to statistical analysis. Coinfections were confirmed in 8% of pneumonia, 11% of bronchitis and 24.2% of the rest concomitant diagnoses.

CONCLUSIONS

We found hMPV infection as the significant agent ofpneumonia not only in children but also in adults. ELISA hMPV antigen test can be used in diagnosis of etiological agent of respiratory infections in children and adults and in coinfections as well.

ParB deficiency in Pseudomonas aeruginosa destabilizes the partner protein ParA and affects a variety of physiological parameters

Deletions leading to complete or partial removal of ParB were introduced into the Pseudomonas aeruginosa chromosome. Fluorescence microscopy of fixed cells showed that ParB mutants lacking the C-terminal domain or HTH motif formed multiple, less intense foci scattered irregularly, in contrast to the one to four ParB foci per cell symmetrically distributed in wild-type P. aeruginosa. All parB mutations affected both bacterial growth and swarming and swimming motilities, and increased the production of anucleate cells. Similar effects were observed after inactivation of parA of P. aeruginosa. As complete loss of ParA destabilized its partner ParB it was unclear deficiency of which protein is responsible for the mutant phenotypes. Analysis of four parB mutants showed that complete loss of ParB destabilized ParA whereas three mutants that retained the N-terminal 90 aa of ParB did not. As all four parB mutants demonstrate the same defects it can be concluded that either ParB, or ParA and ParB in combination, plays an important role in nucleoid distribution, growth and motility in P. aeruginosa.

Age-related change in duration of afterhyperpolarization of human motoneurones

Motor unit (MU) potentials were recorded from brachial biceps of healthy subjects aged 5.5-79 years. The subjects were subdivided into young (5.5-19 year) and adult (37.5-79 year) groups, between which single MU discharge characteristics were compared. Firing rates were in the ranges of 8.3-21.7 s(-1) (mean 12.87 s(-1)) and 5.9-18.7 s(-1) (mean 11.08 s(-1)) for young and adult groups, respectively. Standard deviations (s.d.) of interspike intervals (ISIs) were in the range 4.84-11.57 ms (mean 8.39 ms) for the young group and 4.26-12.23 ms (mean 7.76 ms) for the adult group. Both differences were statistically significant (P < 0.001). Special attention was paid to the previously developed method of ISI variability analysis, which enabled the comparison of MUs with respect to afterhyperpolarization (AHP) duration of their motoneurones (MNs). The results show that AHP duration increases gradually with increasing age, which is in line with the transformation of muscle properties towards a slower phenotype. This transformation seems to be a continuous process, covering the entire lifespan of a human being, from childhood to senescence. The results presented here are significant for their insight into the ageing process of the neuromuscular system. The age-related change in AHP duration has not been investigated previously in human studies and has been met with ambiguous results in animal studies.

[Alexithymia and depression: relationship to cigarette smoking, nicotine dependence and motivation to quit smoking]

The aim of the study was to examine an alexithymia score and depression among people smoking cigarettes and also to examine association between alexithymia, depression and smoking index, nicotine addiction, the motivation to quit smoking. The study comprised 46 people from Warsaw and its environs, without pulmonary, cardiovascular or neoplastic diseases, with at least medium education. The subjects were qualified into two groups: group I (n = 22) - subjects who had never smoked cigarettes, and group II - currently smoking (n=24). The total alexithymia score and scores of alexithymia subscales: difficulty in identifying feelings (TIE), b) difficulty in communicating feelings (TOU), c) externally oriented thinking (OSM) were assessed with Toronto Alexi. thymia Scale 20 (TAS-20). Beck Depression Inventory (Scale) (BDI) was used to evaluate presence and intensification of depression symptoms. The tobacco addiction rate was assessed with the Fagestrom questionnaire, and the motivation to quit smoking with the Schneider test. All data were obtained during individual exami. nations. The mean alexithymia score in the nonsmokers group was 38.6+/-8.8, in the smokers group: 46.6+/-13.0. The differences between the groups were statistically significant (p=0.02). Both difficulty in identifying feelings (TIE) and difficulty in communicating feelings (TOU) scores were significantly higher in the smokers (TIE p=0.01; TOU p=0.03). There were no differences in externally oriented thinking. It was found that people smoking cigarettes had a significantly higher level of intensification of depression symptoms than the controls. There was not any correlation between the total alexithymia score and depression symptoms or smoking index, the degree of nicotine addiction, the motivation to quit smoking.

[Comparative analysis of nicotine dependence and motivation to quit smoking in patients with bronchial asthma or COPD]

The aim of the study was to assess differences in tobacco addiction rate and motivation to quit tobacco smoking in patients with bronchial asthma and chronic obstructive pulmonary disease (COPD). The study comprised 384 males from Warsaw and its environs, aiming to quit smoking within the nearest year, without cardiovascular or neoplastic diseases, with at least medium education (17.19). The subjects were qualified into one of three groups: a control group--subjects without pulmonary diseases (n=143), patients with COPD (n=126) and patients with bronchial asthma (n=115). The smoking index (pack-years) was calculated in each group. The tobacco addiction rate was assessed with the Fageström questionnaire, and the motivation to quit smoking with the Schneider test. All data were obtained during individual examinations. The mean smoking index in the study population was 29.0 +/- 20.6 pack-years (control--27.0 +/- 20.6; asthma--25.2 +/- 14.2 and COPD--38.0 +/- 21.4). A high tobacco addiction rate was found in 40.5% of the patients with COPD, 37.1% of the patients with asthma and 30.3% of the subjects from the control group. The differences between the groups were not statistically significant (p>0.05). In the asthmatic group the percentage of subjects with a high motivation to quit smoking was significantly lower (48%) than in the COPD group (74%, p=0.005) and the control group (75%, p=0.002). It was found that patients with COPD significantly more frequently than asthmatics and people without pulmonary diseases need medical assistance in overcoming nicotine addiction.

[Application of the principles of minimum intervention by primary health care doctors--evaluation by patients addicted to nicotine]

The aim of the study was to analyze to what extend the principles of minimum intervention are applied by basic health care doctors in Mazovia. The study comprised 326 tobacco smokers, divided into two groups: group I--including 160 adults living in towns with a population below 10000 and group II--including 166 inhabitants of towns with a population above 100000. Each subject had their tobacco dependence rate (the Fagerström test) and the period of smoking (pack-years) calculated. Each subject evaluated application of the minimum intervention principles by their basic health care doctor anonymously. The data obtained were statistically analyzed. The study groups did not differ in terms of nicotine addiction rate. It was found that almost half of the patients smoking tobacco had never been asked by their doctor about smoking habit during consultation. An educational material concerning the harmfulness of smoking is received by every seventh smoker, and an attempt of a pharmacological therapy of addiction is undertaken only in every tenth patient. The minimum medical intervention principles in tobacco smokers are twice more often applied by basic health care doctors working in small towns.

[Effect of some demographic and social factors on the degree of nicotine addiction and motivation to quit smoking in healthy people]

AIM

Estimation of the influence of some demographical and social factors on degree of nicotine addiction and motivation to quit smoking.

MATERIAL AND METHOD

208 healthy, smoking people entered the study. The Fagerström test was used for analyzing degree of nicotine addiction (heavy addiction > 7 points). Motivation for smoking cessation was estimated by Schneider test (high motivation > 5 positive answers). Tests results were analyzed in connection with age, gender, education and intensity of nicotine addiction defined as pack-years.

RESULTS

In 37% of patients (77/208) heavy nicotine addiction was diagnosed. High motivation for quitting smoking was recognized in 74% people (150/208). Subjects with wild nicotine addiction had significantly higher motivation for smoking cessation (chi2, p=0.002). There was not influence of gender, age, education and addiction intensity (defined as pack-years) on the grade of nicotine addiction. We didn't notice relation between gender and motivation to quit. Young, well educated patients are significantly stronger motivated for smoking cessation.

CONCLUSIONS

There was not direct dependence between the number of smoked cigarettes and degree of nicotine addiction. In the group of healthy subjects, young, well educated people have a better chance for smoking cessation.

[Blood serum eotaxin and eosinophil cationic protein in asthmatic patients]

Eotaxin belongs to CC class of chemokines and is a potent eosinophil chamoattractant. Activated eosinophils are able to release many cytotoxic proteins, including eosinophil cationic protein (ECP), which has central role in allergic inflammation. The aim of this study was to assess eotaxin and ECP levels in plasma of atopic asthma patients in stable period of the disease. 19 patients with asthma and 10 healthy controls took part in this study. ELISA test was used to measure eotaxin (kits from R&D, pg/ml) and ECP (kits from Pharmacia, mg/l) levels. Plasma eotaxin level (mean +/- SD) was 176.52 +/- 50.3 (range 89-288) in asthma patients and 101.42 +/- 49.4 (range 35-206) in control group (p < 0.001). Plasma ECP concentration was 16.7 +/- 6.4 (6.3-28) and 16.8 +/- 17.1 (3.1-61.6), respectively (n.s). There was correlation between plasma eotaxin and ECP levels (Pearsons correlation co. r = +0.5, p < 0.05) and between eotaxin and FEV1 (Pearsons correlation co r = -0.4, p < 0.05) in asthma patients. We suggest that measurement of eotaxin and ECP levels as well may be useful indicator of disease.

Eotaxin in serum of patients with asthma or chronic obstructive pulmonary disease: relationship with eosinophil cationic protein and lung function

This study was undertaken to investigate the correlation between the serum ECP and the serum eotaxin level, and disease activity as evaluated with pulmonary function in patients with asthma or chronic obstructive pulmonary disease (COPD). 20 patients with stable asthma and 15 patients with COPD, and 15 subjects of the control group took part in this study. The analysis of ECP was performed according to the manufacturer's directions (Pharmacia Diagnostics AB, Uppsala, Sweden). The ELISA test was used to measure eotaxin levels in sserum (kits from R&D, USA). The levels of ECP were 16.9+/-6.3 microg/L in patients with asthma, 15.1+/-9.3 microg/L in patients with COPD and 11.8+/-6.2 microg/L in the control group (P<0.05). There was no significant difference in the asthma ECP level compared with the ECP level in COPD. There was a significant difference between the ECP plasma level in asthma compared with the ECP plasma level in the control group (p<0.05). The levels of eotaxin were 175.8+/-49.3 pg/mL in the control group. There was a correlation of ECP and the eotaxin level in asthma patients (r=+0.5, p<0.05). The percentage fall in FEV1 correlated with eotaxin level in asthma (r=-0.3, p<0.05) and with the eotaxin level in COPD (r=-0.5, p<0.05). Serum outcomes of eotaxin and ECP levels appear to be a useful indicator of atopic asthma, and might provide complementary data disease monitoring. Therefore, further investigations are required to clarify whether serum eotaxin measurements have a role in the clinical evaluation in COPD.

Are motoneurons involved in muscular dystrophy?

In the early seventies, a suggestion that even in muscular dystrophy a neurogenic factor may be involved, was formulated. The argument which followed this suggestion, resulted in eventual abandoning of this concept even by its author. This discussion however has never been supported by any systematic study of motoneuron activity in muscular dystrophy. We examined an activity of motoneurons supplying brachial biceps in eight controls and 26 patients affected by Duchenne muscular dystrophy by studying single motor unit (MU) potentials picked up by fine wire bipolar electrodes. In the majority of patients, MU firing rates were higher as compared to controls and increased more rapidly with increasing force level. The relationship between standard deviation of interspike intervals and their mean value, SD(x), was shifted towards the shorter intervals and lower SDs. The numerical values describing these changes were correlated with severity of the disease. There is evidence that the break-point of the function SD(x) is correlated with motoneuron properties, in particular with after-hyperpolarization duration. In muscular dystrophy, this break-point corresponds to the shorter interspike intervals. We suggest that the motoneurons in muscular dystrophy are altered either in response to the muscle degeneration, or as a result of the disease itself.

Motoneurons are altered in muscular dystrophy

The activity of motoneurons supplying the brachial biceps muscle was examined in eight control subjects and 26 patients affected by Duchenne muscular dystrophy. The patients were subdivided into two groups: one whose motor units (MU) fired with normal rates (N group) and the other whose MU firing rates were higher as compared to controls (I group). Firing rates of motoneurons of patients from group I increased more rapidly with increasing force level. The relationship between the standard deviation of interspike intervals and their mean value, sigma(Tm), was shifted towards the shorter intervals and lower standard deviations in both groups of patients. The numerical values describing these changes correlated with the severity of disease. The MU recruitment was comparable for control subjects and for patients. Experimental results as well as computer simulations indicate that the break-point of the function sigma(Tm) is correlated with motoneuronal properties, and in particular with the afterhyperpolarization (AHP) duration. In muscular dystrophy this break-point corresponds to the shorter interspike intervals. Therefore, we propose that the motoneurons in muscular dystrophy are altered either in response to the muscle degeneration or as a result of the disease itself.