Recombinant actin-depolymerizing factor of the apicomplexan Neospora caninum (NcADF) is susceptible to oxidation

Neospora caninum is a member of Apicomplexa Phylum and the causative agent of neosporosis, a disease responsible for abortions in cattle. Apicomplexan parasites have a limited set of actin-binding proteins conducting the regulation of the dynamics of nonconventional actin. The parasite actin-based motility is implicated in the parasite invasion process in the host cell. Once no commercial strategy for the neosporosis control is available, the interference in the parasite actin function may result in novel drug targets. Actin-depolymerization factor (ADF) is a member of the ADF/cofilin family, primarily known for its function in actin severing and depolymerization. ADF/cofilins are versatile proteins modulated by different mechanisms, including reduction and oxidation. In apicomplexan parasites, the mechanisms involved in the modulation of ADF function are barely explored and the effects of oxidation in the protein are unknown so far. In this study, we used the oxidants N-chlorotaurine (NCT) and H₂O₂ to investigate the susceptibility of the recombinant N. caninum ADF (NcADF) to oxidation. After exposing the protein to either NCT or H₂O₂, the dimerization status and cysteine residue oxidation were determined. Also, the interference of NcADF oxidation in the interaction with actin was assessed. The treatment of the recombinant protein with oxidants reversibly induced the production of dimers, indicating that disulfide bonds between NcADF cysteine residues were formed. In addition, the exposure of NcADF to NCT resulted in more efficient oxidation of the cysteine residues compared to H₂O₂. Finally, the oxidation of NcADF by NCT reduced the ability of actin-binding and altered the function of NcADF in actin polymerization. Altogether, our results clearly show that recombinant NcADF is sensitive to redox conditions, indicating that the function of this protein in cellular processes involving actin dynamics may be modulated by oxidation.

N-chlorotaurine is highly active against respiratory viruses including SARS-CoV-2 (COVID-19) in vitro

N-chlorotaurine (NCT) a long-lived oxidant generated by leukocytes, can be synthesized chemically and applied topically as an anti-infective to different body sites, including the lung via inhalation. Here, we demonstrate the activity of NCT against viruses causing acute respiratory tract infections, namely severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza viruses, and respiratory syncytial virus (RSV). Virucidal activity of NCT was tested in plaque assays, confirmed by RT-qPCR assays. Attack on virus proteins was investigated by mass spectrometry. NCT revealed broad virucidal activity against all viruses tested at 37°C and pH 7. A significant reduction in infectious particles of SARS-CoV-2 isolates from early 2020 by 1 log₁₀ was detected after 15 min of incubation in 1% NCT. Proteinaceous material simulating body fluids enhanced this activity by transchlorination mechanisms (1 −2 log₁₀ reduction within 1–10 min). Tested SARS-CoV-2 variants B.1.1.7 (Alpha) und B.1.351 (Beta) showed a similar susceptibility. Influenza virus infectious particles were reduced by 3 log₁₀ (H3N2) to 5 log₁₀ (H1N1pdm), RSV by 4 log₁₀ within a few min. Mass spectrometry of NCT-treated SARS-CoV-2 spike protein and 3C-like protease, influenza virus haemagglutinin and neuraminidase, and RSV fusion glycoprotein disclosed multiple sites of chlorination and oxidation as the molecular mechanism of action. Application of 1.0% NCT as a prophylactic and therapeutic strategy against acute viral respiratory tract infections deserves comprehensive clinical investigation.

Efficacy of Inhaled N-Chlorotaurine in a Mouse Model of Lichtheimia corymbifera and Aspergillus fumigatus Pneumonia

N-chlorotaurine (NCT) can be used topically as a well-tolerated anti-infective at different body sites. The aim of this study was to investigate the efficacy of inhaled NCT in a mouse model of fungal pneumonia. Specific pathogen-free female C57BL/6JRj seven-week-old mice were immune-suppressed with cyclophosphamide. After 4 days, the mice were inoculated intranasally with 1.5 × 10E7 spores of Lichtheimia corymbifera or 1.0 × 10E7 spores of Aspergillus fumigatus. They were randomized and treated three times daily for 10 min with aerosolized 1% NCT or 0.9% sodium chloride starting 1 h after the inoculation. The mice were observed for survival for two weeks, and fungal load, blood inflammation parameters, bronchoalveolar lavage, and histology of organs were evaluated upon their death or at the end of this period. Inhalations were well-tolerated. After challenge with L. corymbifera, seven out of the nine mice (77.8%) survived for 15 days in the test group, which was in strong contrast to one out of the nine mice (11.1%) in the control group (p = 0.0049). The count of colony-forming units in the homogenized lung tissues came to 1.60 (1.30; 1.99; median, quartiles) log₁₀ in the test group and to 4.26 (2.17; 4.53) log₁₀ in the control group (p = 0.0032). Body weight and temperature, white blood count, and haptoglobin significantly improved with NCT treatment. With A. fumigatus, all the mice except for one in the test group died within 4 days without a significant difference from the control group. Inhaled NCT applied early demonstrated a highly significant curative effect in L. corymbifera pneumonia, while this could not be shown in A. fumigatus pneumonia, probably due to a too high inoculum. Nevertheless, this study for the first time disclosed efficacy of NCT in pneumonia in vivo.

A self-help app for Syrian refugees with posttraumatic stress (Sanadak): results of a randomized controlled trial

Background

Syrian refugees often develop posttraumatic stress as a result of the Syrian civil war and migration stressors. However, there is a lack of adequate treatments. The smartphone app Sanadak was developed and evaluated to provide cognitive behavioral therapy-based self-help in the Arabic language for Syrian refugees with posttraumatic stress.

Methods

In a randomized controlled trial, eligible individuals were allocated to the intervention group (IG; app) or control group (CG; psychoeducational reading material). Data were collected during structured face-to-face interviews at 3 assessments (preintervention/baseline, postintervention/after 4 weeks, follow-up/after 4 months). Using adjusted mixed-effects models, changes in posttraumatic stress and secondary outcomes were investigated as intention-to-treat (ITT) and per-protocol (PP) analysis.

Results

Of 170 screened individuals (aged 18-65 years), 133 were eligible and randomized to the IG (n = 65) or CG (n = 68). Although there was a pre-post reduction in posttraumatic stress, ITT showed no significant differences between IG and CG after 4 weeks (Posttraumatic Diagnostic Scale for DSM-5, Diff -0.90, 95%CI -0.24 to 0.47; P=.52) and after 4 months (Diff -0.39, 95%CI -3.24 to 2.46; P=.79). The same was true for PP. Regarding secondary outcomes, ITT indicated a treatment effect for self-stigma after 4 weeks (Self-Stigma of Mental Illness Scale/SSMIS-stereotype agreement: d = 0.86, 95%CI 0.46 to 1.25; stereotype application: d = 0.60, 95%CI 0.22 to 0.99) and after 4 months (d = 0.52, 95%CI 0.12 to 0.92; d = 0.50, 95%CI 0.10 to 0.90).

Conclusions

Sanadak reduced mild to moderate posttraumatic stress in Syrian refugees, but not superior to the control condition. Therefore, Sanadak may not be suitable as a standalone treatment. However, as the app usability was very good, no harms detected, and stigma significantly reduced, Sanadak has potential as a bridging aid within a stepped and collaborative care approach.

Activity of N-Chlorotaurine against Long-Term Biofilms of Bacteria and Yeasts

Background: N-chlorotaurine (NCT), an antiseptic that originates from the human defense system, has broad-spectrum microbicidal activity and is well tolerated by human tissue and applicable to sensitive body regions. Bacteria in short-term biofilms, too, have been shown to be killed by NCT. It was the aim of the present study to demonstrate the activity of NCT against bacteria and yeasts in longer-lasting biofilms, including their co-culture. Materials and methods: Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella variicola biofilms were grown for 14 weeks in MBECTM inoculator with 96 well base. Some pegs were pinched off weekly and incubated in 1% NCT in PBS (PBS only for controls) at pH 7.1 and 37 °C, for 30 and 60 min. Subsequently, bacteria were resuspended by ultrasonication and subjected to quantitative cultures. Similar tests were conducted with C. albicans biofilms grown on metal (A2-steel) discs for 4 weeks. Mixed co-cultures of C. albicans plus each of the three bacterial strains on metal discs were grown for 5-7 weeks and weekly evaluated, as mentioned above. Results: Single biofilms of S. aureus, P. aeruginosa, and K. variicola grew to approximately 1 × 106 colony forming units (CFU)/mL and C. albicans to 1 × 105 CFU/mL. In combined biofilms, the CFU count was about 1 log10 lower. Viable counts of biofilms of single bacteria were reduced by 2.8 to 5.6 log10 in 1% NCT after 60 min (0.9 to 4.7 log10 after 30 min) with Gram-negative bacteria being more susceptible than S. aureus. Significant reduction of C. albicans by 2.0 to 2.9 log10 occurred after 4 h incubation. In combined biofilms, viable counts of C. albicans were reduced by 1.1 to 2.4 log10 after 4 h, while they reached the detection limit after 1 to 2 h with bacteria (2.0 to > 3.5 log10 reduction). Remarkably, older biofilms demonstrated no increase in resistance but constant susceptibility to NCT. This was valid for all tested pathogens. In electron microscopy, morphological differences between NCT-treated and non-treated biofilms could be found. Conclusions: NCT is active against long-term biofilms of up to several months irrespective of their age. Combined biofilm cultures of yeasts and bacteria show a similar susceptibility pattern to NCT as single ones. These results contribute to the explanation of the clinical efficacy of NCT, for instance, in infected chronic wounds and purulently coated crural ulcerations.

Oxidant therapy improves adipogenic differentiation of adipose-derived stem cells in human wound healing

Background

Adipose-derived stem cells (ASC) and adipocytes are involved in numerous physiological and pathophysiological conditions, which have been extensively described in subcutaneous and visceral fat depots over the past two decades. However, much less is known about ASC and adipocytes outside classical fat tissue depots and their necessity in tissue remodeling after injury. Therefore, we investigated the etiology of adipocytes in human granulation tissue and define their possible role wound healing.

Methods

Identification of human wound tissue adipocytes was determined by immunohistochemical staining of granulation tissue sections from patients undergoing surgical debridement. Stromal cell fractions from granulation tissue and subcutaneous fat tissue were generated by collagenase type II-based protocols. Pro- and anti-inflammatory wound bed conditions were mimicked by THP1- and CD14⁺ monocyte-derived macrophage models in vitro. Effects of macrophage secretome on ASC differentiation and metabolism were determined by immunoblotting, flow cytometry, and microscopy assessing early and late adipocyte differentiation states. Functional rescuing experiments were conducted by lentiviral transduction of wildtype PPARG, IL1RA, and N-chlorotaurine (NCT) treatment.

Results

Single and clustered adipocyte populations were detected in 11 out of 13 granulation tissue specimens and single-cell suspensions from granulation tissue showed adipogenic differentiation potential. Pro-inflammatory signaling by IFNG/LPS-stimulated macrophages (M (IFNG/LPS)) inhibited the maturation of lipid droplets in differentiated ASC. In contrast, anti-inflammatory IL4/IL13-activated macrophages (M (IL4/IL13)) revealed minor effects on adipocyte development. The M (IFNG/LPS)-induced phenotype was associated with a switch from endogenous fatty acid synthesis to glycolysis-dominated cell metabolism and increased pro-inflammatory cytokine production. Impaired adipogenesis was associated with increased, but seemingly non-functional, CEBPB levels, which failed to induce downstream PPARG and CEBPA. Neither transgenic PPARG overexpression, nor inhibition of IL1B was sufficient to rescue the anti-adipogenic effects induced by IFNG/LPS-activated macrophages. Instead, macrophage co-treatment during stimulation with NCT, a mild oxidant produced by activated granulocytes present in human wounds in vivo, significantly attenuated the anti-adipogenic effects.

Conclusions

In conclusion, the appearance of adipocytes in wound tissue indicates a prevailing anti-inflammatory environment that could be promoted by NCT treatment and may be associated with improved healing outcomes.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02336-3.

N-chlorotaurine, a potent weapon against multiresistant bacteria

Aims

N‐chlorotaurine (NCT) is a body‐own mild oxidizing antiseptic that can be applied topically as a well‐tolerated anti‐infective at many body sites. The objective of this study was to demonstrate its activity against representative nosocomial multidrug‐resistant bacteria.

Methods and Results

The bactericidal activity of NCT was tested in quantitative killing assays against a panel of multiresistant Gram‐positive and Gram‐negative clinical isolates. N‐chlorotaurine (1%, 55 mmol l⁻¹) reduced the number of CFU of strains of methicillin‐resistant Staphylococcus aureus, linezolid‐resistant Staphylococcus epidermidis, vancomycin‐resistant, and linezolid‐ and vancomycin‐resistant Enterococcus faecium, 3MRGN and 4MRGN Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae by at least 2 log₁₀ steps after 15 min and completely or nearly to the detection limit after 30 min at pH 7·1 and 37°C.

Conclusion

The activity of NCT against these clinical isolates is similar to that against non‐resistant ATCC strains and therefore not influenced by antibiotic resistance. This can be explained by the oxidizing and chlorinating mechanism of action of NCT, which leads to an attack of multiple targets in the microorganisms.

Significance and Impact of the Study

The bactericidal spectrum of NCT is not restricted by resistance against antibiotics. Therefore, it can be used against resistant strains, too.

Bromamine T (BAT) Exerts Stronger Anti-Cancer Properties than Taurine (Tau)

Simple Summary

Taurine (Tau) has been shown to inhibit cancer growth. However, the mechanisms that underlie the growth-inhibitory effects of Tau remain obscure in both colon and breast cancer. In parallel, N-bromotaurine (TauNHBr) and a stable active bromine molecule, bromamine T (BAT), appear to exert strong anti-inflammatory effects. To our knowledge, this is the first study that evaluates the anti-cancer effects of BAT and its underlying mechanisms. To gain a comprehensive picture of the cytotoxic effect of BAT on colon and breast cancer, we compared its effect with that of Tau. Our data support that BAT exerts a superior anti-cancer effect than Tau, through the induction of cell death, probably due to the activation of distinct mitogen-activated protein kinase (MAPK) family members. Interestingly, BAT inhibits colon carcinogenesis in vivo to a greater extent than Tau. Our data significantly add to the use of BAT as a novel therapeutic modality in colon and breast cancer.

Abstract

Background: Taurine (Tau) ameliorates cancer pathogenesis. Researchers have focused on the functional properties of bromamine T (BAT), a stable active bromine molecule. Both N-bromotaurine (TauNHBr) and BAT exert potent anti-inflammatory properties, but the landscape remains obscure concerning the anti-cancer effect of BAT. Methods: We used Crystal Violet, colony formation, flow cytometry and Western blot experiments to evaluate the effect of BAT and Tau on the apoptosis and autophagy of cancer cells. Xenograft experiments were used to determine the in vivo cytotoxicity of either agent. Results: We demonstrated that both BAT and Tau inhibited the growth of human colon, breast, cervical and skin cancer cell lines. Among them, BAT exerted the greatest cytotoxic effect on both RKO and MDA-MB-468 cells. In particular, BAT increased the phosphorylation of c-Jun N-terminal kinases (JNK½), p38 mitogen-activated protein kinase (MAPK), and extracellular-signal-regulated kinases (ERK½), thereby inducing mitochondrial apoptosis and autophagy in RKO cells. In contrast, Tau exerted its cytotoxic effect by upregulating JNK½ forms, thus triggering mitochondrial apoptosis in RKO cells. Accordingly, colon cancer growth was impaired in vivo. Conclusions: BAT and Tau exerted their anti-tumor properties through the induction of (i) mitochondrial apoptosis, (ii) the MAPK family, and iii) autophagy, providing novel anti-cancer therapeutic modalities.

Childhood maltreatment in bariatric patients and its association with postoperative weight, depressive, and eating disorder symptoms

PURPOSE

The present study aimed to compare prevalence rates of childhood maltreatment between patients with severe obesity undergoing bariatric surgery and patients without a surgical procedure. Second purpose was to calculate the association between childhood maltreatment and outcomes 6 and 12 months after a bariatric procedure.

METHODS

Childhood maltreatment was assessed using the Childhood Trauma Questionnaire (CTQ) and compared between 120 bariatric surgery patients and 346 non-surgery patients with severe obesity. For the bariatric surgery subgroup, linear mixed models with repeated measures were used to analyze the predictive value of childhood maltreatment on weight outcomes and psychopathology. Additionally, between- and within-group comparisons were calculated to compare patients with and without childhood maltreatment regarding BMI and weight loss (%TWL, %EWL), depression severity (BDI-II), eating disorder psychopathology (EDE-Q), and suicidal ideation (BSS), at baseline, 6- and 12-month assessment.

RESULTS

Prevalence rates for childhood maltreatment, depression and suicidal ideation were significantly higher in non-surgery compared to bariatric surgery patients. Within the surgery group, no significant interaction effect between childhood maltreatment and time was found. Hence, childhood maltreatment did not impact the course of body weight, depression and eating disorder psychopathology from pre- to post-surgery.

CONCLUSIONS

Significantly higher rates of childhood maltreatment were found within non-surgery patients with obesity in comparison to bariatric surgery patients. Childhood maltreatment did not predict poorer outcomes after surgery. Since history of childhood maltreatment may increase the risk for psychological disturbances, regular screening and, if necessary, psychological support should be offered to both groups.

LEVEL OF EVIDENCE

Evidence obtained from well-designed cohort or case-control analytic studies, Level III.

CLINICAL TRIAL REGISTRATION

Deutsches Register Klinischer Studien-German Clinical Trials Register: DRKS00003976.

Successful treatment of a unique chronic multi-bacterial scalp infection with N-chlorotaurine, N-bromotaurine and bromamine T

Microbial species can act in synergy to circumvent environmental stress conditions and survive. In addition, biofilms are a serious public-health issue globally and constitute a clinical emergency. Infection persistence, increased morbidity and mortality, and antibiotic resistance are consequences of poly-microbial synergy. Due to inherited complexity and synergy between numerous species, newer antimicrobial agents of increased efficacy and tolerability are needed. In this unique medical case, a chronic (9 year) multi-bacterial scalp infection was differentially diagnosed from other inflammatory skin disorders by prolonged microbiological culture. The bacterial species found seem to have caused lesions of visible biofilm not documented previously in the medical literature. This complicated infection was treated successfully and rapidly with the combined topical application of the active halogen compounds N-chlorotaurine, N-bromotaurine and bromamine T, which is in contrast to the previous failed systemic and topical therapeutic approaches. This study strengthens the case for the use of active halogen compounds against multi-bacterial infections of the skin in the future, without the occurrence of resistance.

Microbicidal activity of N-chlorotaurine can be enhanced in the presence of lung epithelial cells

BACKGROUND

N-chlorotaurine (NCT) is an endogenous active chlorine compound that can be used as an antiseptic and anti-infective in different body regions. Recently, tolerability of inhaled NCT has been demonstrated in humans so that it is of interest for future treatment of cystic fibrosis. In the present study, we tested the bactericidal and fungicidal activity of NCT in different lung cell culture models.

METHODS

Bacteria (Staphylococcus aureus, Pseudomonas aeruginosa) and fungi (Candida albicans, Exophiala dermatitidis) were co-incubated with lung epithelial cell cultures, and after 4 h NCT was added. After different incubation times, aliquots were removed and quantitative cultures were performed.

RESULTS

NCT at the therapeutically applied concentration of 1% (55 mM) completely killed the test pathogens within 15 - 30 min at 20 °C and at 37 °C. Killing by 0.3% NCT lasted up to 4 h dependent on the pathogen at 20 °C and up to 1 h at 37 °C. 0.1% NCT was the threshold concentration for killing since this amount of oxidation capacity was consumed by reactions with the organic compounds of the medium within 3 h (20 °C) and 0.5 h (37 °C).

CONCLUSIONS

NCT in therapeutic concentration demonstrated its microbicidal activity in the presence of lung epithelial cells. Remarkably, particularly the fungicidal activity was higher under these conditions than in phosphate buffer. This can be explained by formation of the stronger microbicidal monochloramine in equilibrium by transchlorination. The results suggest the suitability of NCT as inhalation medication in the lung.

Development and Validation of an HPLC Method for the Quantitative Analysis of Bromophenolic Compounds in the Red Alga Vertebrata lanosa

Bromophenols are a class of compounds occurring in red algae that are thought to play a role in chemical protection; however, their exact function is still not fully known. In order to investigate their occurrence, pure standards of seven bromophenols were isolated from a methanolic extract of the epiphytic red alga Vertebrata lanosa collected in Brittany, France. The structures of all compounds were determined by NMR and MS. Among the isolated substances, one new natural product, namely, 2-amino-5-(3-(2,3-dibromo-4,5-dihydroxybenzyl)ureido)pentanoic acid was identified. An HPLC method for the separation of all isolated substances was developed using a Phenomenex C8(2) Luna column and a mobile phase comprising 0.05% trifluoroacetic acid in water and acetonitrile. Method validation showed that the applied procedure is selective, linear (R² ≥ 0.999), precise (intra-day ≤ 6.28%, inter-day ≤ 5.21%), and accurate (with maximum displacement values of 4.93% for the high spikes, 4.80% for the medium spikes, and 4.30% for the low spikes). For all standards limits of detection (LOD) were lower than 0.04 μg/mL and limits of quantification (LOQ) lower than 0.12 μg/mL. Subsequently, the method was applied to determine the bromophenol content in Vertebrata lanosa samples from varying sampling sites and collection years showing values between 0.678 and 0.005 mg/g dry weight for different bromophenols with significant variations between the sampling years. Bioactivity of seven isolated bromophenols was tested in agar diffusion tests against Staphylococcus aureus and Escherichia coli bacteria. Three compounds showed a small zone of inhibition against both test organisms at a concentration of 100 µg/mL.

Inactivation of Adenovirus in Water by Natural and Synthetic Compounds

Millions of people use contaminated water sources for direct consumption. Chlorine is the most widely disinfection product but can produce toxic by-products. In this context, natural and synthetic compounds can be an alternative to water disinfection. Therefore, the aim of this study was to assess the inactivation of human adenovirus by N-chlorotaurine (NCT), bromamine-T (BAT) and Grape seed extract (GSE) in water. Distilled water artificially contaminated with recombinant human adenovirus type 5 (rAdV-GFP) was treated with different concentrations of each compound for up to 120 min, and viral infectivity was assessed by fluorescence microscopy. The decrease in activity of the compounds in the presence of organic matter was evaluated in water supplemented with peptone. As results, NCT and GSE inactivated approximately 2.5 log₁₀ of adenovirus after 120 min. With BAT, more than 4.0 log₁₀ decrease was observed within 10 min. The oxidative activity of 1% BAT decreased by 50% in 0.5% peptone within a few minutes, while the reduction was only 30% for 1% NCT in 5% peptone after 60 min. Organic matter had no effect on the activity of GSE. Moreover, the minimal concentration of BAT and GSE to kill viruses was lower than that known to kill human cells. It was concluded that the three compounds have potential to be used for water disinfection for drinking or reuse purposes.

Swift Cure of a Chronic Wound Infected With Multiresistant Staphylococcus aureus in an Elderly Patient With Stage 5 Renal Disease

We present a case of a 91-year-old female with stage 5 renal disease, diabetes type 2, and considerable weakness, suffering from a 2-month-old wound infected by a multiresistant Staphylococcus aureus. The wound measured 7 cm in length, 5 cm in width, and 1.5 cm in depth, having purulent white edges and exudates exceeding the size of the wound. The systemic antibiotic use was opposing to improve the patient's clinical condition due to underlying nephrotoxicity that may have deteriorated renal failure and resistance of the infecting pathogen. The halogenated taurine (Tau) derivatives N-chlorotaurine (NCT) and N-bromotaurine (NBrT) with potent anti-inflammatory and antimicrobial efficacy were alternatively employed as combination topical treatment to provide a therapeutic solution. Each agent was applied separately with an interval of 5 minutes as a 1% spray in aqueous solution every 30 minutes during the day for 3 days. This treatment was very well tolerated and led to rapid disappearance of the purulent exudate, rapid epithelialization, and complete healing. To avoid relapse, the application was continued 4 times daily for a further 4 days. No complications occurred in the course of treatment. This case report confirms the therapeutic efficacy of NCT in chronic purulent wounds. NBrT is well tolerated, too, and can be used in combination with NCT in emergency clinical settings. Its potential as a single agent should be investigated in further studies. Advancement of wound closure by these agents proved to be life-saving for this patient. Further molecular research is needed to identify mechanisms that promote wound healing.

Potentiometric characterization of iodine-based disinfecting preparations

A potentiometric method is presented that allows to characterize aqueous iodine-based disinfecting solutions and preparations, respectively. By means of three electrodes (iodide-sensitive, platinum redox, and reference electrode), the concentrations of free iodine, iodide, and triiodide were determined. The apposition "free" means iodine not complexed with ligands originating from the organic matrix of the iodophoric iodine source (e.g. povidone iodine). Based on the gained values ([I₂], [I^-], and[I₃^-]), it is possible to assess features concerning kinetics of disinfection, disinfecting capacity, and tolerability. The method distinguishes by simplicity and modest time expenditure of 10-15 min for a complete investigation comprising two potentiometric measurements.

Tolerability of inhaled N-chlorotaurine in humans: a double-blind randomized phase I clinical study

BACKGROUND

N-chlorotaurine (NCT), a long-lived oxidant produced by human leukocytes, can be synthesized chemically and used topically as a well-tolerated antiseptic to different body regions including sensitive ones. The aim of this study was to test the tolerability of inhaled 1% NCT in aqueous solution upon repeated application.

METHODS

The study was performed double-blind and randomized with a parallel test group (1% NCT) and control group (0.9% NaCl as placebo). There were two Austrian centres involved, the hospitals, Natters and Vöcklabruck. Healthy, full age volunteers were included, 12 in each centre. A total of 12 patients were treated with NCT, and 12 with placebo, exactly half of each group from each centre. The single dose was 1.2 ml inhaled over a period of 10 min using an AKITA JET nebulizer. One inhalation was done every day for five consecutive days. The primary criterion of evaluation was the forced expiratory volume in 1 second (FEV₁). Secondary criteria were subjective sensations, further lung function parameters such as airway resistance, physical examination, and blood analyses (gases, electrolytes, organ function values, pharmacokinetic parameters taurine and methionine, immune parameters).

RESULTS

All included 15 females and 9 males completed the treatment and the control examinations according to the study protocol. FEV₁ (100.83% ± 8.04% for NCT and 92.92% ± 11.35% for controls) remained unchanged and constant during the treatment and in control examinations 1 week and 3 months after the treatment (98.75% ± 7.37% for NCT and 91.17% ± 9.46% for controls, p > 0.082 between time points within each group). The same was true for all other objective parameters. Subjective mild sensations with a higher frequency in the test group were chlorine taste ( p < 0.01) and occasional tickle in the throat ( p = 0.057). Taurine and methionine plasma concentrations did not change within 60 min after inhalation or later on.

CONCLUSIONS

Inhaled NCT is well tolerated as in other applications of different body regions. Side effects are mild, topical and transitory. The study was registered prospectively in the European Clinical Trials Database of the European Medicines Agency. The EudraCT number is 2012-003700-12.

Exposure to N-chlorotaurine induces oxidative stress responses in Aspergillus fumigatus

PURPOSE

The neutrophil-derived oxidant N-chlorotaurine (NCT) displays remarkable in vivo tolerability and efficacy against a range of pathogens. The aim of this study was to characterize the response of the pulmonary pathogen Aspergillus fumigatus to NCT.

METHODOLOGY

The effect of NCT on the growth and viability of A. fumigatus was characterized. NCT-induced alteration of amino acids and gliotoxin from A. fumigatus mycelium was assessed. Label-free shotgun quantitative proteomic analysis was performed on A. fumigatus exposed to NCT for 24 h.

RESULTS

Incubation of A. fumigatus with NCT at concentrations ranging from 6.8 to 55 mM decreased conidial growth and viability, and mycelium biomass relative to the controls. Exposure to NCT (13.77 mM) resulted in increased amino acids and gliotoxin levels from A. fumigatus mycelium. Exposure of A. fumigatus mycelium to NCT (6.8 mM) revealed an enrichment in proteins associated with the ribosome, transcription and translation and non-ribosomal peptide biosynthesis (e.g. Pes1, Pes3), which play an essential role in oxidative stress resistance in A. fumigatus. A decrease in the abundance of proteins associated with fumagillin and pseurotin biosynthesis highlighted the anti-virulence activity of NCT.

CONCLUSION

These results indicate that NCT induces an oxidative stress response in A. fumigatus as evidenced by alterations in the proteome and inhibits conidial and mycelial growth. Clinical investigations of topical application of NCT to treat Aspergillus infections are encouraged.

Scedosporium and Lomentospora: an updated overview of underrated opportunists

Species of Scedosporium and Lomentospora are considered as emerging opportunists, affecting immunosuppressed and otherwise debilitated patients, although classically they are known from causing trauma-associated infections in healthy individuals. Clinical manifestations range from local infection to pulmonary colonization and severe invasive disease, in which mortality rates may be over 80%. These unacceptably high rates are due to the clinical status of patients, diagnostic difficulties, and to intrinsic antifungal resistance of these fungi. In consequence, several consortia have been founded to increase research efforts on these orphan fungi. The current review presents recent findings and summarizes the most relevant points, including the Scedosporium/Lomentospora taxonomy, environmental distribution, epidemiology, pathology, virulence factors, immunology, diagnostic methods, and therapeutic strategies.

Comparative Analysis of Microbicidal and Anti-inflammatory Properties of Novel Taurine Bromamine Derivatives and Bromamine T

Taurine, the most abundant free amino acid in leukocyte cytosol traps hypohalous acids (HOCl and HOBr) to produce N-chlorotaurine (taurine chloramine, NCT and N-bromotaurine (taurine bromamine, Tau-NHBr,) respectively. Both haloamines show anti-inflammatory and antimicrobial properties. However, the therapeutic applicability of Tau-NHBr is limited due to its relatively poor stability. To overcome this disadvantage, we have synthesized the stable N-bromotaurine compounds N-monobromo-2,2-dimethyltaurine (Br-612) and N-dibromo-2,2-dimethyltaurine (Br-422). The aim of this study was to compare anti-inflammatory and microbicidal properties of Br-612 and Br-422 with that of Tau-NHBr and bromamine T (BAT). We have shown that all the tested compounds show similar anti-inflammatory properties. Importantly, the stable N-bromotaurine compounds exerted even stronger microbicidal activity than Tau-NHBr. Finally, for the purpose of topical application of these compounds we have developed a carbomer-based bioadhesive solid dosage form of BAT and Br-612, featuring sustained release of the active substance.

The endogenous antiseptic N-chlorotaurine irreversibly inactivates Chlamydia pneumoniae and Chlamydia trachomatis

PURPOSE

The antimicrobial activity of N-chlorotaurine (NCT), an endogenous long-lived oxidant applied topically, was tested against Chlamydiae in vitro.

METHODOLOGY

Elementary bodies of Chlamydia pneumoniae strain CV-6 and Chlamydia trachomatis serovars A and D were incubated in 0.01, 0.1 and 1 % (w/v) NCT solution at pH 7.1 and 37 °C. After different incubation times, aliquots were removed and grown in cell culture. The number of inclusion forming units was quantified by immunofluorescence and real-time qPCR.Results/Key findings.Chlamydia pneumoniae and Chlamydia trachomatis were inactivated by 1 and 0.1 % NCT within 1 min. Moreover, 0.025-0.1 % NCT significantly reduced the number of intracellularly growing C. pneumoniae within 30 min.

CONCLUSIONS

This is the first study demonstrating the antimicrobial activity of NCT against Chlamydiae. Clinical implications of these findings have to be investigated in further trials.

In Vitro Study on the Influence of N-Chlorotaurine on the Ciliary Beat Frequency of Nasal Mucosa

Background

The aim of this study was to investigate the in vitro effects of N-chlorotaurine (NCT), a new endogenous antimicrobial agent, on the nasal ciliary beat frequency (CBF) in nasal mucosa samples of 10 adult patients who underwent conchotomy.

Methods

CBF was measured by a photometric technique, combining a light microscope, a photometer, a photograph multiplier, and a computed analyzing unit.

Results

CBF decreased ∼10% after 20 minutes of incubation in aqueous 1% NCT solution compared with 3% in 0.9% saline, and 0.1 and 0.01% NCT had no effect. However, a solution of 7% cocaine, which is used routinely for shrinking the nasal mucosa before rhinoscopy lowered the CBF to 50% after the same incubation time.

Conclusion

These results confirm the very low toxic potential of NCT, and they are fundamental for clinical investigations regarding its topical application in the nasal and paranasal sinuses.

Microbicidal activity of N-chlorotaurine in combination with hydrogen peroxide

N-chlorotaurine (NCT) and hydrogen peroxide are powerful endogenous antiseptics. In vivo, the reaction between hydrogen peroxide and metal ions leads to the formation of free hydroxyl radicals, which have an increased bactericidal activity. This study examined whether there is an additive antimicrobial effect of NCT combined with hydrogen peroxide. Additionally, it was tested if the additive effect is based on the formation of free radicals. We found by luminometry that, in the presence of H₂O₂, NCT caused a slow and long-lasting production of singlet oxygen in contrast to HOCl, where this burst occurred instantaneously. Both NCT and hydrogen peroxide (1.0 and 0.1%) demonstrated bactericidal and fungicidal activity. At pH 7.1 and 37 °C, hydrogen peroxide (1%, 294 mM) showed a stronger bactericidal and particularly fungicidal activity than NCT (1%, 55 mM), whereas at pH 4.0 and also in the presence of 5.0% peptone NCT revealed a stronger bactericidal activity. A combination of NCT and hydrogen peroxide led to an increased bactericidal but no increased fungicidal activity compared to both substances alone. The additive effect against bacteria was not removed in the presence of the radical scavengers NaN₃, DMSO, or peptone. As a conclusion, NCT and hydrogen peroxide used concurrently interact additive against a range of microorganisms. However, the results of this study suggest that the additive effect of NCT combined with hydrogen peroxide is rather not based on the formation of free radicals.

Pseudomonas aeruginosa outcompetes other bacteria in the manifestation and maintenance of a biofilm in polyvinylchloride tubing as used in dental devices

In a PVC tube as a model system for dental devices, Pseudomonas aeruginosa outcompetes Staphylococcus aureus and Klebsiella pneumoniae for the biofilm formation. P. aeruginosa has advantage over the other strains due to higher tolerance for low-nutrient situations or direct killing by the production of soluble factors like pyocyanin.

[Questionnaire "Coping Procedures - Goals and Appraisals": Development and First Psychometric Evaluation in Patients with Chronic Back Pain]

AIM

Development of a disease specific Common Sense Model of Self-Regulation (CSM) based questionnaire assessing 'coping procedures', and their 'appraisal'. In this article, we describe the questionnaire and conduct a psychometric evaluation of the 'coping procedures'.

METHODS

The item pool was generated in a multimodal way. Data were collected from 9 orthopedic rehabilitation centres, with longitudinal measurement at 3 points in time. The sample comprised N=214 rehabilitation patients.

RESULTS

The questionnaire comprises CSM-based items with respect to coping procedures, their goals, and their appraisal. The coping procedures items loaded onto 2 scales, which reflected coping procedures with a focus on activity vs. biomedicine. A confirmatory analysis of a model with these 2 factors indicated an acceptable model fit. The distribution characteristics of the scales were in the range of normal distribution. Internal consistency was acceptable. The data show construct validity, sensitivity to change, comprehensibility and acceptance of the questionnaire.

CONCLUSIONS

The psychometric results were satisfactory. The practical implications of our results are discussed.

Microbial contamination of glaucoma eyedrops used by patients compared with ocular medications used in the hospital

The aim of this study was to compare the percentage of contamination of multiuse eyedrops applied by glaucoma patients at home and by the medical personnel at the outpatient department, the ward, and the operating room of our Department of Ophthalmology. Eyedrops were collected over a period of 11 months. Samples were taken from the dropper tip (smear), drops, and the residual fluid inside the bottle and cultivated on blood agar. Colony forming units were counted and identified by mass spectrometry. The percentage of contamination was significantly higher in eyedrops applied by the patients (29/119; 24.4%, P < 0.01), used in the ward (26/133; 19.5%, P < 0.01), and in the outpatient unit (6/35; 17.1%, P = 0.036) compared with that in the operating room (6/113; 5.3%). The median period of use was 1 week in the operating room compared with 4 weeks in the other groups (P < 0.01). Glaucoma medications were significantly more frequently contaminated than antibiotic and anesthetic eyedrops (P < 0.05). For eyedrops applied by the patients, the tip was more frequently contaminated than the drops and the residual internal fluid. For eyedrops from the ward, the opposite was true. Pathogenic strains (Pseudomonas aeruginosa, Serratia marcescens, Acinetobacter lwoffii, Stenotrophomonas maltophilia, and Staphylococcus aureus) were found only in 6 bottles (1.5%), whereas most of the detected microbes belonged to human or environmental flora. This study underlines the importance of hygienic handling of eyedrops and raises the question of whether single-use glaucoma medication might be preferred to reduce the risk of contamination.

Influence of poly-N-acetylglucosamine in the extracellular matrix on N-chlorotaurine mediated killing of Staphylococcus epidermidis

N-chlorotaurine (NCT) has recently been shown to have bactericidal activity against bacterial biofilm on metal discs (Coraca-Huber et al., 2014). In a biofilm, Staphylococcus epidermidis polymerizes poly-N-acetylglucosamine (PNAG) to form an extracellular matrix (ECM). Pseudomonas aeruginosa does not express this PNAG and has been shown to be highly susceptible to NCT. We compared the action of NCT on S. epidermidis 1457, a PNAG positive strain (SE1457) and S. epidermidis 1457- M10 an isogenic PNAG negative mutant (SE1457 M10). NCT-mediated killing was more effective and quicker on the PNAG negative strain SE1457 M10. Bacteria hidden in biofilms for prolonged periods of time were generally more susceptible than freshly formed biofilms. The differences in NCT-mediated killing might not be direct effects since NCT did not react with the monomeric N-acetylglucosamine, but might be explained by denser growth in the PNAG-containing biofilm produced by the wild type strain, which results in delayed penetration of NCT. The higher susceptibility of older biofilms to NCTmediated killing could be explained by more pronounced 3D architecture and subsequent larger surface area for interactions with NCT.

Superior bactericidal activity of N-bromine compounds compared to their N-chlorine analogues can be reversed under protein load

AIMS

To investigate and compare the bactericidal activity (BA) of active bromine and chlorine compounds in the absence and presence of protein load.

METHODS AND RESULTS

Quantitative killing tests against Escherichia coli and Staphylococcus aureus were performed both in the absence and in the presence of peptone with pairs of isosteric active chlorine and bromine compounds: hypochlorous and hypobromous acid (HOCl and HOBr), dichloro- and dibromoisocyanuric acid, chlorantine and bromantine (1,3-dibromo- and 1,3 dichloro-5,5-dimethylhydantoine), chloramine T and bromamine T (N-chloro- and N-bromo-4-methylbenzenesulphonamide sodium), and N-chloro- and N-bromotaurine sodium. To classify the bactericidal activities on a quantitative basis, an empirical coefficient named specific bactericidal activity (SBA), founded on the parameters of killing curves, was defined: SBA= mean log reductions/(mean exposure times x concentration) [mmol 1(-1) min (-1)]. In the absence of peptone, tests with washed micro-organisms revealed a throughout higher BA of bromine compounds with only slight differences between single substances. This was in contrast to chlorine compounds, whose killing times differed by a factor of more than four decimal powers. As a consequence, also the isosteric pairs showed according differences. In the presence of peptone, however, bromine compounds showed an increased loss of BA, which partly caused a reversal of efficacy within isosteric pairs.

CONCLUSIONS

In medical practice, weakly oxidizing active chlorine compounds like chloramines have the highest potential as topical anti-infectives in the presence of proteinaceous material (mucous membranes, open wounds). Active bromine compounds, on the other hand, have their chance at insensitive body regions with low organic matter, for example skin surfaces.

SIGNIFICANCE AND IMPACT OF THE STUDY

The expected protein load is one of the most important parameters for selection of a suited active halogen compound.

N-chlorotaurine and its analogues N,N-dichloro-2,2-dimethyltaurine and N-monochloro-2,2-dimethyltaurine are safe and effective bactericidal agents in ex vivo corneal infection models

PURPOSE

N-chlorotaurine (NCT) and its analogues N-monochloro-2,2-dimethyltaurine (NVC-612) and N-dichloro-2,2-dimethyltaurine (NVC-422) are new anti-infectives for topical treatment for conjunctivitis. The aim of this study was to show that these compounds are safe in an EpiOcular model and effective in corneas infected ex vivo.

METHODS

Corneal buttons were excised from porcine eyes. In 183 of the 229 corneas, erosion and artificial superficial stromal incision were induced. They were bathed in suspensions of Pseudomonas aeruginosa or Staphylococcus aureus for 24 hr at 37°C and incubated in solutions of the test substances at 37°C and pH 7.1. Subsequently, they were subjected to histology (n = 20) or homogenized followed by quantitative bacterial cultures (n = 209). Ocular irritation was tested using the EpiOcular™ tissue system (MatTek Corporation).

RESULTS

Bacterial accumulations were detected histologically both on the corneal surface and also in the anterior third of the stroma of incised corneal buttons. All three test compounds at a concentration of 55 mm (equals 1% NCT) reduced the bacterial counts of P. aeruginosa and S. aureus by approximately 5 log10 after 60- and 120-min incubation, respectively. Significant killing was observed as early as after 5-min incubation. Also intrastromal bacteria were inactivated. In the EpiOcular™ tissue model, NCT, NVC-422 and NVC-612 had no or very low potential to irritate corneal tissue.

CONCLUSION

N-chlorotaurine, NVC-422 and NVC-612 are non-irritating in cornea and kill P. aeruginosa and S. aureus, even following penetration into the deeper corneal stromal layers.

N-chlorotaurine, a long-lived oxidant produced by human leukocytes, inactivates Shiga toxin of enterohemorrhagic Escherichia coli

N-chlorotaurine (NCT), the main representative of long-lived oxidants produced by granulocytes and monocytes, is known to exert broad-spectrum microbicidal activity. Here we show that NCT directly inactivates Shiga toxin 2 (Stx2), used as a model toxin secreted by enterohemorrhagic Escherichia coli (EHEC). Bacterial growth and Stx2 production were both inhibited by 2 mM NCT. The cytotoxic effect of Stx2 on Vero cells was removed by ≥5.5 mM NCT. Confocal microscopy and FACS analyses showed that the binding of Stx2 to human kidney glomerular endothelial cells was inhibited, and no NCT-treated Stx2 entered the cytosol. Mass spectrometry displayed oxidation of thio groups and aromatic amino acids of Stx2 by NCT. Therefore, long-lived oxidants may act as powerful tools of innate immunity against soluble virulence factors of pathogens. Moreover, inactivation of virulence factors may contribute to therapeutic success of NCT and novel analogs, which are in development as topical antiinfectives.

Characterization of volatile metabolites taken up by or released from Streptococcus pneumoniae and Haemophilus influenzae by using GC-MS

Volatile organic compounds (VOCs) released from or taken up by Streptococcus pneumoniae and Haemophilus influenzae cultures were analysed by means of GC-MS after adsorption of headspace samples on multi-bed sorption tubes. Sampling was performed at different time points during cultivation of bacteria to follow the dynamics of VOC metabolism. VOCs were identified not only by spectral library match but also based on retention times of native standards. As many as 34 volatile metabolites were released from S. pneumoniae and 28 from H. influenzae, comprising alcohols, aldehydes, esters, hydrocarbons, ketones and sulfur-containing compounds. For both species, acetic acid, acetaldehyde, methyl methacrylate, 2,3-butanedione and methanethiol were found in strongly elevated concentrations and 1-butanol and butanal in moderately elevated concentrations. In addition, characteristic volatile biomarkers were detected for both bacterial species and exclusively for S. pneumoniae, also catabolism of aldehydes (3-methylbutanal and hexanal) was found. The results obtained provide important input into the knowledge about volatile bacterial biomarkers, which may become particularly important for detection of pathogens in upper airways by breath-gas analysis in the future.

Active halogen compounds and proteinaceous material: loss of activity of topical anti-infectives by halogen consumption

OBJECTIVES

The activity of oxidants, such as halogens and active halogen compounds, decreases generally in the presence of proteinaceous material. A quantification of consumption effects was performed to judge the suitability of different representatives as antiseptics and their compatibility with pharmaceutical additives.

METHODS

An iodometric approach served to assess the temporal loss of oxidation capacity in the presence of peptone and fetal calf serum (FCS). The tested agents comprised active halogen compounds, well-known and in particular novel chloramine-based agents indicated for the topical treatment of infections.

KEY FINDINGS

The decrease in oxidation capacity was higher in the presence of FCS than of peptone and correlated with the reactivity of the oxidants in both cases. The highest consumption rates were for active bromine compounds followed by hypochlorous acid and heterocyclic chlorimides, such as dichloro-isocyanuric acid, while N-chlorotaurine and related amine-based analogues were least consumed. The pH dependence was only remarkable for chloramine T.

CONCLUSIONS

The observed consumption effects are the result of the differing oxidizing (chlorinating) potencies. Since consumption and irritation are founded on the very same reactions, representatives with low reactivity (N-chloro amino acids) are regarded as more tolerable and retain more oxidative capacity, which provides a more sustained antimicrobial activity.

Electric field gradients at (111)In/(111)Cd probe atoms on A-sites in 211-MAX phases

The method of perturbed angular correlation (PAC) was applied to selected MAX phases with 211 stoichiometry. Radioactive (111)In ions were implanted in order to measure the electric field gradients (EFG) in the key compounds Ti(2)InC and Zr(2)InC to determine the strength and symmetry of the EFG at the In-site. Further PAC studies in the In-free MAX phases Ti(2)AlN, Nb(2)AlC, Nb(2)AsC and Cr(2)GeC were performed to confirm that the In probes occupy the A-site as well. The strength of the EFG, with a quadrupole coupling constant ν(Q) between 250 and 300 MHz in these phases, is quite similar to the ones found in Ti(2)InC with ν(Q) = 292(1) MHz and in Zr(2)InC with ν(Q) = 344(1) MHz, respectively. Different annealing behavior was observed whereas in all cases a linear decrease of ν(Q) with increasing measuring temperatures was found. The experimental results are also in excellent agreement with those predicted by ab initio calculations using the APW+lo method implemented in the WIEN2k code. This study shows in an exceptional manner that (111)In → (111)Cd atoms are suitable probes to investigate the local surrounding at the A-site in 211-MAX phases.

Tolerability of inhaled N-chlorotaurine in an acute pig streptococcal lower airway inflammation model

Background

Inhalation of N-chlorotaurine (NCT), an endogenous new broad spectrum non-antibiotic anti-infective, has been shown to be very well tolerated in the pig model recently. In the present study, inhaled NCT was tested for tolerability and efficacy in the infected bronchopulmonary system using the same model.

Methods

Anesthetized pigs were inoculated with 20 ml of a solution containing approximately 10⁸ CFU/ml Streptococcus pyogenes strain d68 via a duodenal tube placed through the tracheal tube down to the carina. Two hours later, 5 ml of 1% NCT aqueous solution (test group, n = 15) or 5 ml of 0.9% NaCl (control group, n = 16) was inhaled via the tracheal tube connected to a nebulizer. Inhalation was repeated every hour, four times in total. Lung function and haemodynamics were monitored. Bronchoalveolar lavage samples were removed for determination of colony forming units (CFU), and lung samples for histology.

Results

Arterial pressure of oxygen (PaO₂) decreased rapidly after instillation of the bacteria in all animals and showed only a slight further decrease at the end of the experiment without a difference between both groups. Pulmonary artery pressure increased to a peak 1-1.5 h after application of the bacteria, decreased in the following hour and remained constant during treatment, again similarly in both groups. Histology demonstrated granulocytic infiltration in the central parts of the lung, while this was absent in the periphery. Expression of TNF-alpha, IL-8, and haemoxygenase-1 in lung biopsies was similar in both groups. CFU counts in bronchoalveolar lavage came to 170 (10; 1388) CFU/ml (median and 25 and 75 percentiles) for the NCT treated pigs, and to 250 (10; 5.5 × 10⁵) CFU/ml for NaCl treated pigs (p = 0.4159).

Conclusions

Inhaled NCT at a concentration of 1% proved to be very well tolerated also in the infected bronchopulmonary system. This study confirms the tolerability in this delicate body region, which has been proven in healthy pigs previously. Regarding efficacy, no conclusions can be drawn, mainly because of the limited test period of the model.

[The development of an instrument assessing the relevance of rehabilitation outcomes for patient participation: retest reliability and descriptive results]

OBJECTIVE

In the context of an increasing patient orientation in health care, surveying patients on the success of treatment has become highly relevant. The objective of the study was to develop and test an instrument for surveying the patients' perceptions of the participation relevance of changes in health status after inpatient medical rehabilitation with respect to various areas of life for 3 diagnoses: breast cancer, chronic ischemic heart disease, and chronic back pain.

METHODS

The instrument refers to certain disease-specific areas of health (e. g., mobility) with regard to which the patients are asked whether they perceived an improvement and if so, what improvement in participation had ensued as a result. A questionnaire study (measuring time points: end of rehab and 6 months after the end of rehab) was conducted in 3 samples (breast cancer: n=297, chronic ischemic heart disease: n=295, chronic back pain: n=186) to test the methodology. The share of missing values and undesirable ceiling/floor effects were assessed to analyze the distribution characteristics. In a partial sub-sample, a third measuring time point was introduced approx. 10 days after the second measuring time point, and the retest reliability of the assessment of participation relevance is determined using the ICC. We also present descriptive results relative to the participation relevance from the patient perspective.

RESULTS

The instrument shows good distribution characteristics for the items. Regarding retest reliability, there were satisfactory values for all diagnoses in all areas of health. The descriptive analyses showed that patients who perceived a noticeable improvement in their health status at the end of rehabilitation or 6 months after inpatient rehab generally assessed the participation relevance of this improvement in health to be "moderate" to "strong".

DISCUSSION

The concept of assessing the participation relevance from the patient perspective is a satisfactorily reliable construct. By including the subjective significance of treatment success it takes into account the concept of clinical significance from the patient's perspective, a concept which has thus far been considered only insufficiently. Results show that patients ascribe the health improvements achieved by rehabilitation a noticeable relevance for their participation.

In vitro activity of N-chlorotaurine (NCT) in combination with NH4Cl against Trichomonas vaginalis

Trichomoniasis, caused by the protozoan Trichomonas vaginalis, is usually treated with metronidazole, however resistance is on the rise. In this study, N-chlorotaurine (NCT), a new endogenous mild active chlorine compound for topical use, killed T. vaginalis in vitro within 15 min of treatment at a concentration of 55 mM (1%), which is well tolerated by human tissue. The activity of NCT was further enhanced by addition of ammonium chloride (NH(4)Cl). A combination of 5.5 mM (0.1%) NCT plus 19 mM (0.1%) NH(4)Cl killed 100% of trichomonads within 5 min.

The influence of plasma on the disinfecting activity of the new antimicrobial agent N-chlorotaurine-sodium in comparison with chloramine T

The phenomenon of increasing bactericidal activity of N-chlorotaurine in the presence of chlorine-consuming material has been investigated both on a chemical-analytical and microbiological basis using plasma as substrate and chloramine T for comparison. Chlorine consumption assessed by iodometric titration showed a biphasic time-course with a very fast loss of oxidation capacity within one minute (N-chlorotaurine: — 9.3%, chloramine T: −16.8%) followed by a slow loss which could still be detected after 24 h (total loss −61.7% and −74.1%, respectively). Killing curves revealed that an increase in bactericidal activity, in spite of improved consumption, did not occur with all strains, and could be detected only at a certain degree of consumption. Escherichia coli and Pseudomonas aeruginosa showed the most pronounced effect, Streptococcus pyogenes and Proteus mirabilis a medium-sized one, while it was absent in Staphylococcus aureus. With chloramine T, an increase in bactericidal activity could not be proved. The chemical basis of these consumption effects can be reduced to four reaction types: oxidation of thiols; chlorine substitution of activated C-H compounds; transhalogenation; and hydrolytic degradation of N-chloro-α-amino acids and -peptides emerging by transhalogenation. The initial fast loss of oxidation capacity can be attributed mainly to oxidation of thiols, while the subsequent slower decrease is caused by the other types of reaction. The increase in bactericidal activity, on the other hand, can be explained by transhalogenation, leading to the formation of more bactericidal N-chloro compounds by which the loss of N-chlorotaurine is over-compensated.

N-chlorotaurine, a natural antiseptic with outstanding tolerability

N-chlorotaurine, the N-chloro derivative of the amino acid taurine, is a long-lived oxidant produced by activated human granulocytes and monocytes. Supported by a high number of in vitro studies, it has mainly anti-inflammatory properties and seems to be involved in the termination of inflammation. The successful synthesis of the crystalline sodium salt (Cl-HN-CH(2)-CH(2)-SO(3)Na, NCT) facilitated its development as an endogenous antiseptic. NCT can be stored long-term at low temperatures, and it has killing activity against bacteria, fungi, viruses and parasites. Transfer of the active chlorine to amino groups of molecules of both the pathogens and the human body (transhalogenation) enhances rather than decreases its activity, mainly because of the formation of monochloramine. Furthermore, surface chlorination after sublethal incubation times in NCT leads to a post-antibiotic effect and loss of virulence of pathogens, as demonstrated for bacteria and yeasts. Being a mild oxidant, NCT proved to be very well tolerated by human tissue in Phase I and II clinical studies. A 1% aqueous solution can be applied to the eye, skin ulcerations, outer ear canal, nasal and paranasal sinuses, oral cavity and urinary bladder, and can probably be used for inhalation. Therapeutic efficacy in Phase II studies has been shown in external otitis, purulently coated crural ulcerations and keratoconjunctivitis, so far. Based upon all presently available data, NCT seems to be an antiseptic with a very good relation between tolerability and activity. Recently, C-methylated derivatives of NCT have been invented, which are of interest because of improved stability at room temperature.