A bead-based multiplex assay covering all coronaviruses pathogenic for humans for sensitive and specific surveillance of SARS-CoV-2 humoral immunity

Serological assays measuring antibodies against SARS-CoV-2 are key to describe the epidemiology, pathobiology or induction of immunity after infection or vaccination. Of those, multiplex assays targeting multiple antigens are especially helpful as closely related coronaviruses or other antigens can be analysed simultaneously from small sample volumes, hereby shedding light on patterns in the immune response that would otherwise remain undetected. We established a bead-based 17-plex assay detecting antibodies targeting antigens from all coronaviruses pathogenic for humans: SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV strains 229E, OC43, HKU1, and NL63. The assay was validated against five commercial serological immunoassays, a commercial surrogate virus neutralisation test, and a virus neutralisation assay, all targeting SARS-CoV-2. It was found to be highly versatile as shown by antibody detection from both serum and dried blot spots and as shown in three case studies. First, we followed seroconversion for all four endemic HCoV strains and SARS-CoV-2 in an outbreak study in day-care centres for children. Second, we were able to link a more severe clinical course to a stronger IgG response with this 17-plex-assay, which was IgG1 and IgG3 dominated. Finally, our assay was able to discriminate recent from previous SARS-CoV-2 infections by calculating the IgG/IgM ratio on the N antigen targeting antibodies. In conclusion, due to the comprehensive method comparison, thorough validation, and the proven versatility, our multiplex assay is a valuable tool for studies on coronavirus serology.

Flexible upscaling of laboratory PCR testing capacity at the Robert Koch Institute during the SARS-CoV-2 pandemic

BACKGROUND

Over the course of the COVID-19 pandemic, laboratories worldwide have been facing an unprecedented increase in demand for PCR testing because of the high importance of diagnostics for prevention and control of virus spread. Moreover, testing demand has been varying considerably over time, depending on the epidemiological situation, rendering efficient resource allocation difficult. Here, we present a scalable workflow which we implemented in our laboratory to increase PCR testing capacity while maintaining high flexibility regarding the number of samples to be processed.

METHODS

We compared the performance of five automated extraction instruments, using dilutions of SARS-CoV-2 cell culture supernatant as well as clinical samples. To increase PCR throughput, we combined the two duplex PCR reactions of our previously published SARS-CoV-2 PCR assay into one quadruplex reaction and compared their limit of detection as well as their performance on the detection of low viral loads in clinical samples. Furthermore, we developed a sample pooling protocol with either two or four samples per pool, combined with a specifically adapted SARS-CoV-2 quadruplex PCR assay, and compared the diagnostic sensitivity of pooled testing and individual testing.

RESULTS

All tested automated extraction instruments yielded comparable results regarding the subsequent sensitivity of SARS-CoV-2 detection by PCR. While the limit of detection of the quadruplex SARS-CoV-2 PCR assay (E-Gene assay: 28.7 genome equivalents (ge)/reaction, orf1ab assay: 32.0 ge/reaction) was slightly higher than that of our previously published duplex PCR assays (E-Gene assay: 9.8 ge/reaction, orf1ab assay: 6.6 ge/reaction), the rate of correctly identified positive patient samples was comparable for both assays. Sample pooling with optimized downstream quadruplex PCR showed no loss in diagnostic sensitivity compared to individual testing.

CONCLUSION

Specific adaptation of PCR assays can help overcome the potential loss of sensitivity due to higher levels of PCR multiplexing or sample dilution in pooled testing. Combining these adapted PCR assays with different sample processing strategies provides a simple and highly adjustable workflow for resource-efficient SARS-CoV-2 diagnostics. The presented principles can easily be adopted in a variety of laboratory settings as well as be adapted to pathogens other than SARS-CoV-2, making it feasible for any laboratory that conducts PCR diagnostics.

A large travel-associated outbreak of iatrogenic botulism in four European countries following intragastric botulinum neurotoxin injections for weight reduction, Türkiye, February to March 2023

In March 2023, 34 associated cases of iatrogenic botulism were detected in Germany (30 cases), Switzerland (two cases), Austria (one case), and France (one case). An alert was rapidly disseminated via European Union networks and communication platforms (Food- and Waterborne Diseases and Zoonoses Network, EpiPulse, Early Warning and Response System) and the International Health Regulation mechanism; the outbreak was investigated in a European collaboration. We traced sources of the botulism outbreak to treatment of weight loss in Türkiye, involving intragastric injections of botulinum neurotoxin. Cases were traced using a list of patients who had received this treatment. Laboratory investigations of the first 12 German cases confirmed nine cases. The application of innovative and highly sensitive endopeptidase assays was necessary to detect minute traces of botulinum neurotoxin in patient sera. The botulism notification requirement for physicians was essential to detect this outbreak in Germany. The surveillance case definition of botulism should be revisited and inclusion of cases of iatrogenic botulism should be considered as these cases might lack standard laboratory confirmation yet warrant public health action. Any potential risks associated with the use of botulinum neurotoxins in medical procedures need to be carefully balanced with the expected benefits of the procedure.

Microbiota-sensitive drug delivery systems based on natural polysaccharides for colon targeting

Colon targeting is an ongoing challenge, particularly for the oral administration of biological drugs or local treatment of inflammatory bowel disease (IBD). In both cases, drugs are known to be sensitive to the harsh conditions of the upper gastrointestinal tract (GIT) and, thus, must be protected. Here, we provide an overview of recently developed colonic site-specific drug delivery systems based on microbiota sensitivity of natural polysaccharides. Polysaccharides act as a substrate for enzymes secreted by the microbiota located in the distal part of GIT. The dosage form is adapted to the pathophysiology of the patient and, thus, a combination of bacteria-sensitive and time-controlled release or pH-dependent systems can be used for delivery.

Camptothecin: solubility, in-vitro drug release, and effect on human red blood cells and sperm cold preservation

BACKGROUND

Camptothecin (CPT) is an anticancer drug, and is not employed in the clinic because of its high hydrophobicity and low active form stability. CPT may also have potential for use in cold preservation.

OBJECTIVE

To overcome these drawbacks, CPT solubility variations in the presence of cyclodextrins (CDs) and polyethylene glycol (PEG) were evaluated by Higuchi solubility experiments.

MATERIALS AND METHODS

CPT was encapsulated in different cyclodextrins and polyethylene glycol using a co-evaporation method. The CPT interactions with CDs and PEG 6000 were investigated by Fourier-transformed infrared spectroscopy (FT-IR), and X-ray powder diffraction (XRPD). Then, CPT complexes were evaluated for in-vitro drug release. To evaluate the potential anticancer efficacy of the CPT complexes system, in-vitro cytotoxicity studies on human red blood cells were carried out using UV assay. The impact of the CPT complex systems on sperm motility protection during cold preservation at 4 degree C was studied using CASA.

RESULTS

The dissolution profile of these preparations shows the improvement of the dissolution of the CPT following a fickien diffusion. The CPT solubility and stability improvement were the cause of the cytotoxicity on the red blood cells test. However, CPT alone, encapsulated, dispersed, and chemically modified protected spermatozoids during cold preservation.

CONCLUSION

We confirm the interest in CPT encapsulated and dispersed in anticancer treatments. We also found that CPT encapsulated or dispersed could protect sperm against oxidative damage and improve the membrane integrity of human sperm. Consequently, CPT encapsulated our dispersed could eventually be beneficial for infertility therapy. Doi: 10.54680/fr23210110712.

Drug release, stability and efficiency of vitamin e loaded in liposomes for bovine sperm protection in cryopreservation medium

BACKGROUND

It is known that a considerable number of drugs in clinical use or under development are water-insoluble drugs with poor bioavailability. The liposomal delivery system has drawn attention as one of the noteworthy approaches to increase both dissolution and absorption because of its biocompatibility and ability to encapsulate hydrophobic molecules in the lipid domain. However, several drawbacks have been reported, the most common is liposome structural instability.

OBJECTIVE

To encapsulate alpha tocopherol into liposomes, to determine the new formulation stability and to study the drug-release of alpha tocopherol into the sperm cryopreservation medium.

MATERIALS AND METHODS

The liposomes prepared by an ethanol injection method were characterized for size stability, alpha tocopherol release and sperm motility tests.

RESULTS

The prepared unilamellar vesicles had both narrow size distribution (around 99 nm) and a good physical and chemical stability at 4°C during 12 months. The liposomes did not release the vitamin E immediately, but retained the protectant for 24 hours, probably due to the rigidity of the liposomal fence which was reinforced by adding cholesterol. Then, all vitamin E molecules were released by 48 hours. Release was potentially by Fickian diffusion probably by the creation of mini-ducts due to both agitation and fence hydration. Moreover, semen motility treated with vitamin E liposome preparations was significantly improved compared to all other treatments (including commonly used sperm conservation media).

CONCLUSION

The stable vitamin E liposomes formulated in this work are a promising alternative for semen cryopreservation protection.

Differentiation, Quantification and Identification of Abrin and Abrus precatorius Agglutinin

Abrin, the toxic lectin from the rosary pea plant Abrus precatorius, has gained considerable interest in the recent past due to its potential malevolent use. However, reliable and easy-to-use assays for the detection and discrimination of abrin from related plant proteins such as Abrus precatorius agglutinin or the homologous toxin ricin from Ricinus communis are sparse. To address this gap, a panel of highly specific monoclonal antibodies was generated against abrin and the related Abrus precatorius agglutinin. These antibodies were used to establish two sandwich ELISAs to preferentially detect abrin or A. precatorius agglutinin (limit of detection 22 pg/mL for abrin; 35 pg/mL for A. precatorius agglutinin). Furthermore, an abrin-specific lateral flow assay was developed for rapid on-site detection (limit of detection ~1 ng/mL abrin). Assays were validated for complex food, environmental and clinical matrices illustrating broad applicability in different threat scenarios. Additionally, the antibodies turned out to be suitable for immuno-enrichment strategies in combination with mass spectrometry-based approaches for unambiguous identification. Finally, we were able to demonstrate for the first time how the developed assays can be applied to detect, identify and quantify abrin from a clinical sample derived from an attempted suicide case involving A. precatorius.

Encapsulation Nanotechnology in Sperm Cryopreservation: Systems Preparation Methods and Antioxidants Enhanced Delivery

Sperm cryopreservation promotes the storage and transport of germplasm for its use in artificial insemination (AI) and other advanced reproductive technologies. However, sperm cryopreservation causes several stresses including thermal shock, osmotic damage, and ice crystal formation, thereby reducing sperm quality. Supplementing cryoprotectant media with antioxidants has been reported to be positive in different species. It has been widely suggested to combine antioxidants with nanotechnology, to maximize therapeutic activity and to minimize undesirable side effects. In this review, we discuss the role of different antioxidants in sperm cryopreservation and their improved therapeutic effect through their formulation using nanotechnology. In addition, we report the different nano-systems preparation methods present in literature. Whilst the use of nanotechnology in animal production is still in its infancy, encouraging results from nutrition, biocidal, remedial, and reproductive studies are driving further investigations.

Development, validation and method stability study of a LC-MS method to quantify leuprolide (Hormone analog) in human plasma

A rapid, highly sensitive and simple high-performance liquid chromatographic-tandem mass spectrometric (LC-MS) assay is developed and validated for the quantification of leuprolide: a Gonadotropin Releasing Hormone analog (GnRH) in human plasma. Moreover, various parameters of the method stability are determined. After the addition of stable isotope (internal standard), the leuprolide was extracted from human plasma by a C₁₈ solid phase micro extraction (MEPS) cartridge and directly injected into LC-MS/MS system. Chromatographic separation was achieved using a Waters Atlantis HILIC, C₁₈, 150 × 2.1 mm, 5 μ column. Mobile phase was a mixture of acetate buffer (pH 3) and acetonitrile (25/75). Drug detection was performed by MS using electrospray ionization in positive mode. Multiple reaction monitoring (MRM) with a tandem mass spectrometer was used to detect the analytes. Precursor to product ion transitions of: m/z 605.5 → m/z 110.2 and m/z 609.1 → m/z 249.1 were used to quantify leuprolide and leuprolide-¹³C₆-¹⁵N, respectively. Sample analysis time was 3 min for each injection. The assay exhibited a linear dynamic range of 0.0500-40 ng/ml for each analyte with a lower limit of quantification (LLOQ) of: 0.0500 ng/ml. Furthermore, a complete analytic validation was carried out, including tests on: The specificity, precision, accuracy, matrix effect and stability under different storage conditions. Importantly, the obtained results established: an acceptable precision and accuracy for concentration over standard curve range. Nevertheless, it is to emphasize the simplicity, rapidity and also the high precision and accuracy of this novel LC-MS method, offering useful information about solution stability. Finally, this work is a good alternative to quantify Leuprolide concentration in human blood, especially on human clinic trials step.

Increasing the throughput of label-free cell assays to study the activation of G-protein-coupled receptors by using a serial agonist exposure protocol

Label-free, holistic assays, monitoring, for example, the impedance of cells on electrodes, are gaining increasing popularity in the evaluation of G-protein-coupled receptor (GPCR) ligands. It is the strength of these approaches to provide the integrated cellular response non-invasively, highly automated and with a device-dependent time resolution down to several milliseconds. With an increasing number of samples to be studied in parallel, the available time resolution is, however, reduced and the cost for the disposable sensor arrays may become limiting. Inspired by protocols from organ pharmacology, we investigated a simple serial agonist addition assay that circumvents these limitations in impedance-based cellular assays. Using a serial addition of increasing concentrations of a GPCR agonist while continuously monitoring the sample's impedance, we were able to establish a full concentration-response curve for the endogenous agonist histamine on a single layer of U-373 MG cells endogenously expressing the histamine 1 receptor (H1R). This approach is validated with respect to conventional, parallel agonist addition protocols and studies using H1R antagonists such as mepyramine. Applicability of the serial agonist addition assay was shown for other GPCRs known for their signaling via one of the canonical G-protein pathways, Gq, Gi/0 or Gs as well. The serial agonist addition protocol has the potential to further strengthen the output of label-free analysis of GPCR activation.

Botulinum Neurotoxin F Subtypes Cleaving the VAMP-2 Q58⁻K59 Peptide Bond Exhibit Unique Catalytic Properties and Substrate Specificities

In the recent past, about 40 botulinum neurotoxin (BoNT) subtypes belonging to serotypes A, B, E, and F pathogenic to humans were identified among hundreds of independent isolates. BoNTs are the etiological factors of botulism and represent potential bioweapons; however, they are also recognized pharmaceuticals for the efficient counteraction of hyperactive nerve terminals in a variety of human diseases. The detailed biochemical characterization of subtypes as the basis for development of suitable countermeasures and possible novel therapeutic applications is lagging behind the increase in new subtypes. Here, we report the primary structure of a ninth subtype of BoNT/F. Its amino-acid sequence diverges by at least 8.4% at the holotoxin and 13.4% at the enzymatic domain level from all other known BoNT/F subtypes. We found that BoNT/F9 shares the scissile Q⁵⁸/K⁵⁹ bond in its substrate vesicle associated membrane protein 2 with the prototype BoNT/F1. Comparative biochemical analyses of four BoNT/F enzymatic domains showed that the catalytic efficiencies decrease in the order F1 > F7 > F9 > F6, and vary by up to a factor of eight. K_M values increase in the order F1 > F9 > F6 ≈ F7, whereas k_cat decreases in the order F7 > F1 > F9 > F6. Comparative substrate scanning mutagenesis studies revealed a unique pattern of crucial substrate residues for each subtype. Based upon structural coordinates of F1 bound to an inhibitor polypeptide, the mutational analyses suggest different substrate interactions in the substrate binding channel of each subtype.

To what extent is it possible to dissociate the anxiolytic and sedative/hypnotic properties of GABAA receptors modulators?

The relatively common view indicates a possible dissociation between the anxiolytic and sedative/hypnotic properties of benzodiazepines (BZs). Indeed, GABAA receptor (GABAAR) subtypes have specific cerebral distribution in distinct neural circuits. Thus, GABAAR subtype-selective drugs may be expected to perform distinct functions. However, standard behavioral test assays provide limited direction towards highlighting new action mechanisms of ligands targeting GABAARs. Automated behavioral tests, lack sensitivity as some behavioral characteristics or subtle behavioral changes of drug effects or that are not considered in the overall analysis (Ohl et al., 2001) and observation-based analyses are not always performed. In addition, despite the use of genetically engineered mice, any possible dissociation between the anxiolytic and sedative properties of BZs remains controversial. Moreover, the involvement the different subtypes of GABAAR subtypes in the anxious behavior and the mechanism of action of anxiolytic agents remains unclear since there has been little success in the pharmacological investigations so far. This raises the question of the involvement of the different subunits in anxiolytic-like and/or sedative effects; and the actual implication of these subunits, particularly, α-subunits in the modulation of sedation and/or anxiety-related disorders. This present review was prompted by several conflicting studies on the degree of involvement of these subunits in anxiolytic-like and/or sedative effects. To this end, we explored the GABAergic system, particularly, the role of different subunits containing synaptic GABAARs. We report herein the targeting gene encoding the different subunits and their contribution in anxiolytic-like and/or sedative actions, as well as, the mechanism underlying tolerance to BZs.

Detection, differentiation, and identification of botulinum neurotoxin serotypes C, CD, D, and DC by highly specific immunoassays and mass spectrometry

Botulinum neurotoxin (BoNT) serotypes C and D and their mosaic variants CD and DC cause severe cases of botulism in animal husbandry and wildlife. Epidemiological data on the exact serotype or toxin variant causing outbreaks are rarely available, mainly because of their high sequence identity and the lack of fast and specific screening tools to detect and differentiate the four similar toxins. To fill this gap, we developed four highly specific sandwich enzyme-linked immunosorbent assays (ELISAs) able to detect and differentiate botulinum neurotoxins type BoNT/C, D, CD, and DC based on four distinct combinations of specific monoclonal antibodies targeting both conserved and divergent subdomains of the four toxins. Here, highly sensitive detection with detection limits between 2 and 24 pg mL(-1) was achieved. The ELISAs were extensively validated and results were compared with data obtained by quantitative real-time PCR using a panel of Clostridium botulinum strains, real sample materials from veterinary botulism outbreaks, and non-BoNT-producing Clostridia. Additionally, in order to verify the results obtained by ELISA screening, the new monoclonal antibodies were used for BoNT enrichment and subsequent detection (i) on a functional level by endopeptidase mass spectrometry (Endopep-MS) assays and (ii) on a protein sequence level by LC-MS/MS spectrometry. Based on all technical information gathered in the validation study, the four differentiating ELISAs turned out to be highly reliable screening tools for the rapid analysis of veterinary botulism cases and should aid future field investigations of botulism outbreaks and the acquisition of epidemiological data.

5-HT2C receptors in psychiatric disorders: A review

5-HT2Rs have a different genomic organization from other 5-HT2Rs. 5HT2CR undergoes post-transcriptional pre-mRNA editing generating diversity among RNA transcripts. Selective post-transcriptional editing could be involved in the pathophysiology of psychiatric disorders through impairment in G-protein interactions. Moreover, it may influence the therapeutic response to agents such as atypical antipsychotic drugs. Additionally, 5-HT2CR exhibits alternative splicing. Central serotonergic and dopaminergic systems interact to modulate normal and abnormal behaviors. Thus, 5HT2CR plays a crucial role in psychiatric disorders. 5HT2CR could be a relevant pharmacological target in the treatment of neuropsychiatric disorders. The development of drugs that specifically target 5-HT2C receptors will allow for better understanding of their involvement in the pathophysiology of psychiatric disorders including schizophrenia, anxiety, and depression. Among therapeutic means currently available, most drugs used to treat highly morbid psychiatric diseases interact at least partly with 5-HT2CRs. Pharmacologically, 5HT2CRs, have the ability to generate differentially distinct response signal transduction pathways depending on the type of 5HT2CR agonist. Although this receptor property has been clearly demonstrated, in vitro, the eventual beneficial impact of this property opens new perspectives in the development of agonists that could activate signal transduction pathways leading to better therapeutic efficiency with fewer adverse effects.

Characterization of Ricin and R. communis Agglutinin Reference Materials

Ricinus communis intoxications have been known for centuries and were attributed to the toxic protein ricin. Due to its toxicity, availability, ease of preparation, and the lack of medical countermeasures, ricin attracted interest as a potential biological warfare agent. While different technologies for ricin analysis have been established, hardly any universally agreed-upon "gold standards" are available. Expert laboratories currently use differently purified in-house materials, making any comparison of accuracy and sensitivity of different methods nearly impossible. Technically challenging is the discrimination of ricin from R. communis agglutinin (RCA120), a less toxic but highly homologous protein also contained in R. communis. Here, we established both highly pure ricin and RCA120 reference materials which were extensively characterized by gel electrophoresis, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS), and matrix-assisted laser desorption ionization-time of flight approaches as well as immunological and functional techniques. Purity reached >97% for ricin and >99% for RCA120. Different isoforms of ricin and RCA120 were identified unambiguously and distinguished by LC-ESI MS/MS. In terms of function, a real-time cytotoxicity assay showed that ricin is approximately 300-fold more toxic than RCA120. The highly pure ricin and RCA120 reference materials were used to conduct an international proficiency test.

Generation and Characterization of Six Recombinant Botulinum Neurotoxins as Reference Material to Serve in an International Proficiency Test

The detection and identification of botulinum neurotoxins (BoNT) is complex due to the existence of seven serotypes, derived mosaic toxins and more than 40 subtypes. Expert laboratories currently use different technical approaches to detect, identify and quantify BoNT, but due to the lack of (certified) reference materials, analytical results can hardly be compared. In this study, the six BoNT/A1–F1 prototypes were successfully produced by recombinant techniques, facilitating handling, as well as improving purity, yield, reproducibility and biosafety. All six BoNTs were quantitatively nicked into active di-chain toxins linked by a disulfide bridge. The materials were thoroughly characterized with respect to purity, identity, protein concentration, catalytic and biological activities. For BoNT/A₁, B₁ and E₁, serotypes pathogenic to humans, the catalytic activity and the precise protein concentration were determined by Endopep-mass spectrometry and validated amino acid analysis, respectively. In addition, BoNT/A₁, B₁, E₁ and F₁ were successfully detected by immunological assays, unambiguously identified by mass spectrometric-based methods, and their specific activities were assigned by the mouse LD₅₀ bioassay. The potencies of all six BoNT/A1–F1 were quantified by the ex vivo mouse phrenic nerve hemidiaphragm assay, allowing a direct comparison. In conclusion, highly pure recombinant BoNT reference materials were produced, thoroughly characterized and employed as spiking material in a worldwide BoNT proficiency test organized by the EQuATox consortium.

Fast dissolving cyclodextrin complex of piroxicam in solid dispersion part I: influence of β-CD and HPβ-CD on the dissolution rate of piroxicam

Sublingual drug delivery is an interesting route for drug having significant hepatic first-pass metabolism or requiring rapid pharmacological effect as for patients suffering from swallowing difficulties, nausea or vomiting. Sublingual absorption could however be limited by the kinetic of drug dissolution. This study evaluated influences of cyclodextrins (β-CD or HP-β-CD) and their different inclusion process (spray-drying or freeze-drying) on the drug dissolution kinetic of solid dispersions in poly(ethylene glycol) (PEG, Mw 6000Da) of piroxicam, used as poor hydrosoluble drug model. A secondary objective was to determine influences of drug dispersion process in PEG (evaporation or melting methods) on the drug dissolution kinetic of piroxicam. Piroxicam solid dispersions containing or not cyclodextrins were characterized by different scanning calorimetry (DSC), Thermogravometry analyser (TGA) and Fourier transform-infrared spectroscopy (FT-IR) spectroscopy. In vitro drug dissolution study of these solid dispersions was then performed. The results demonstrated the high potential and interest of solid dispersions of drug previously included in cyclodextrins for sublingual delivery of hydrophobic drugs. This study also showed the advantages of evaporation method on the melting ones during drug dispersion in PEG. Indeed, drug complexation with cyclodextrins as dispersion by melting prevented the presence in solid dispersions of drug in crystalline form which can represent up to 63%. Moreover, dispersion in PEG by evaporation method gave more porous drug delivery system than with melting methods. This allowed complete (limited at most at 80-90% with melting methods) and quick drug dissolution without rebound effect like with melting ones.

Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer

The fuel ion ratio nt/nd is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., nt/nd = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands that a DT spectrometer has to fulfill to be able to determine nt/nd with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.

Preparation and characterization of amorphous solid dispersions of nimesulide in cyclodextrin copolymers

A study to enhance the dissolution rate of nimesulide (NIM), a poorly water-soluble, non-steroidal anti-inflammatory drug, was carried out through developing new amorphous solid dispersions (ASD) based on soluble or insoluble water cyclodextrin copolymers (alpha-cyclodextrin, beta-cyclodextrin and y-cyclodextrin polymers) synthesized by direct melt polycondensation. Amorphous solid dispersions of NIM in cyclodextrin copolymers, obtained by solvent evaporation, were characterized by thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and fourier transform-infrared spectroscopy (FT-IR). These analyses provided the existence of interactions between amorphous drug and its carrier. A burst release of more than 80% NIM within approximately 70 minutes was seen with soluble alpha-cyclodextrin polymers (poly-alpha-sol) and insoluble gamma-cyclodextrin polymers (poly-gamma-insol) where no significant differences were observed with the other copolymers. Mathematical kinetic models such as zero order, Higuchi and Korsmeyer-Peppas were used to evaluate the kinetic and mechanism of release of NIM from the different ASD compared to lactose reference matrix. The kinetic of release of NIM from different ASD followed a Higuchi model and the mechanism of release was explained by Korsmeyer-Peppas model in which a fickian diffusion for lactose and soluble beta-cyclodextrin polymers (poly-beta-sol) was observed. However, an anomalous non-Fickian transport was found for the other copolymers.

Fully digital data acquisition system for the neutron time-of-flight spectrometer TOFOR at JET

A prototype of a fully digital data acquisition system based on 1 Gsps 12 bit digitizers for the TOFOR fusion neutron spectrometer at JET is assessed. The prototype system enables the use of geometry-based background discrimination techniques, which are modeled, evaluated, and compared to experimental data. The experimental results are in line with the models and show a significant improvement in signal-to-background ratio in measured time-of-flight spectrum compared to the existing data acquisition system.

Fuel ion ratio measurements in reactor relevant neutral beam heated fusion plasmas

In this paper, we present a method to derive n(t)/n(d) using the ratio of the thermonuclear neutron emission to the beam-target neutron emission. We apply it to neutron spectroscopy data from the magnetic proton recoil spectrometer taken during the deuterium tritium experiment at JET. n(t)/n(d)-values obtained using neutron spectroscopy are in qualitative agreement with those from other diagnostics measuring the isotopic composition of the exhaust in the divertor.

Is addition of angiotensin receptor blockade superior to increasing ACE inhibitor dose in patients with heart failure?

We conducted a prospective, randomised, open-label, blinded end point (PROBE) study examining the relative efficacy of irbesartan 300 mg/day versus maximising dose of ACE inhibitor, additional to background conventional heart failure therapy. Patients with CHF, NYHA Class II-III and a left ventricular ejection fraction <40% were randomised to one of two treatment arms. All patients were receiving ≤ half target dose of ACE inhibitor as background therapy. 44 patients received an increase in their background ACE inhibitor while 45 patients were given irbesartan (target dose 300 mg/day) in addition to their background ACE inhibitor. The primary end-point was change in brain natriuretic peptide (BNP) from baseline to 6 months. Change in hs-CRP level, 6 min walk distance, and Minnesota living with heart failure quality of life questionnaire (MLWHF) from baseline to 6 months were also evaluated. Patients were well matched at baseline for all end-point parameters as well as for age, gender and baseline systolic ventricular function. There was general improvement in clinical status for all patients but no significant difference between increased ACE inhibitor vs added ARB for change in BNP, hs-CRP, NYHA, 6 min walk or MLWHF (all P>0.05). This PROBE study has demonstrated similar clinical responses with increased dose of ACE inhibitor compared to addition of ARB in patients with systolic CHF. These findings suggest that either approach to increasing renin-angiotensin blockade in patients taking low doses of background ACE inhibitor results in similar clinical outcomes.

A comprehensive proteome map of bovine cerebrospinal fluid

Cerebrospinal fluid (CSF) is considered as the most promising body fluid target for the discovery of biomarkers for early diagnosis of neurodegenerative diseases such as Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. For the recognition of disease-associated changes in bovine CSF protein patterns, a detailed knowledge of this proteome is a prerequisite. The absence of a high-resolution CSF proteome map prompted us to determine all bovine CSF protein spots that can be visualised on 2-D protein gels. Using state-of-the-art 2-DE technology for proteome mapping of bovine ante mortem CSF combined with sensitive fluorescent protein staining and MALDI-TOF/TOF MS for protein identification, a highly detailed 2-DE map of the bovine CSF proteome was established. Besides the proteins mapped by earlier studies, this map contains 66 different proteins, including 58 which were not annotated in bovine 2-DE CSF maps before.

Charcot's Joint of the Wrist in Type 2 Diabetes Mellitus

In patients with diabetes mellitus, Charcot's neuroarthropathy mainly affects major weight-bearing joints, especially the foot and ankle. Remarkably, we report a case of Charcot's joint of the wrist - an unusually rare localization in type 2 diabetic patient. A review of medical literature identified only three such cases so far.

The effect of rapid lipid lowering with atorvastatin on autonomic parameters in patients with coronary artery disease

Many cardiovascular disease states are associated with autonomic dysfunction, specifically sympathetic activation and parasympathetic withdrawal. Both these autonomic derangements are independently associated with adverse prognostic outcomes. HMG CoA reductase inhibitors (statins) reduce cardiovascular mortality and morbidity when compared to placebo in subjects with proven coronary artery disease (CAD), including sudden presumed arrhythmic death. As autonomic dysfunction is associated with arrhythmogenesis, statins may be having a beneficial effect on autonomic function in these subjects. We conducted a randomised, double-blind, placebo-controlled, cross-over study examining the effect of rapid short-term lipid lowering with a statin on autonomic function in CAD patients. Ten subjects with proven CAD (8 male, 2 female; mean age 63.4 years) were randomised to receive either 80 mg atorvastatin or placebo over a 4 week period followed by a 4 week washout, then the alternative treatment for a further 4 weeks. Autonomic parameters assessed were plasma noradrenaline levels on recumbency and 80 degrees head-up tilt, cold pressor testing, and heart rate variability (HRV) analysis. Plasma noradrenaline levels were significantly reduced (p=0.050) after 20 min rest in the recumbent position, with atorvastatin compared to placebo. A nonsignificant reduction in plasma noradrenaline with atorvastatin compared to placebo was observed in the prolonged 80 degrees head-up position (p=0.207). In addition, sympathovagal balance was shifted to greater vagal predominance with atorvastatin (low-frequency/high-frequency ratio in the HRV frequency domain) when compared to placebo, p=0.06. We found that rapid lipid lowering with atorvastatin reduces sympathetic nervous system in this pilot study of CAD patients. Larger trials are required to definitively address the effects of statins on autonomic activity in these patients.

Knowledge about osteoporosis in a cohort of Polish females: the influence of age, level of education and personal experiences

In this study, a group of 1065 women aged 16-72 years recruited from patients attending general practitioners was studied to investigate knowledge of osteoporosis and attitude towards methods of preventing the disease. The interviews were carried out by students of the Silesian School of Medicine, using a structured questionnaire. The average number of correct answers in the whole population was 7.05, and in women with established osteoporosis 6.89. In the whole population, the majority of answers were correct and ranged from 60% to 95% in seven out of ten questions. The answers for three questions were incorrect in about half or more of the cohort: 53% of subjects considered that osteoporosis could be cured; for 50% of women osteoporosis is a minor health problem (except for the youngest women and women with university education--74% and 69% of correct answers, respectively); and 58% of women considered that those with osteoporosis should not engage in physical activity due to the risk of falling and causing a fracture. A simple chi-squared test was used to show the role of age, level of education and personal experiences with osteoporosis on answers given by the subjects studied. Age (six out of ten answers), level of education (seven out of ten answers) and personal experience (four out of ten answers) significantly affected answers given. The number of correct answers decreased with age and increased with level of education, and there was no systematic influence of personal experience. In summary, data collected provide important information about knowledge of osteoporosis. Generally, the level of knowledge about osteoporosis was high. Higher level of education and younger age improve the knowledge of osteoporosis with no systematic influence of personal experience with the disease.

Comparative metabolic effects of hydrochlorothiazide and indapamide in hypertensive diabetic patients receiving ACE inhibitor therapy

BACKGROUND

ACE inhibitors, when used as monotherapy, are frequently unable to adequately control blood pressure in diabetic patients. A diuretic may be added; however, thiazide diuretics, but not indapamide, have been associated with adverse metabolic effects. Whether these effects also apply to thiazides when administered in the currently used lower doses, and whether they differ from indapamide in their metabolic effects, particularly when used in combination with an ACE inhibitor in diabetic patients, has not been previously studied.

METHODS

We conducted a prospective, randomized, open-label, blinded endpoint crossover study comparing the metabolic responses to the addition of either hydrochlorothiazide (HCTZ) or indapamide, in 18 diabetic hypertensive patients receiving ACE inhibitor monotherapy for hypertension. Patients stabilized on fosinopril 20 mg/day were randomized to receive either HCTZ 12.5 mg od or indapamide 2.5 mg od for 8 weeks, then crossed over to the alternate therapy for a further 8-week period. Blood pressure, heart rate and metabolic assessments were performed at the end of each 8-week treatment period.

RESULTS

Seated and standing systolic and diastolic blood pressures were not different between HCTZ or indapamide when added to fosinopril, nor was the fasting lipid profile or urinary albumin : creatinine ratio. Plasma potassium was lower with indapamide compared with HCTZ treatment (indapamide 4.3+/-0.1 mmol/l; HCTZ 4.5+/-0.1 mmol/l, P<0.01) and HbA1c was higher with indapamide than with HCTZ therapy (indapamide 7.8+/-0.4%; HCTZ 7.2+/-0.3%, P<0.01).

CONCLUSIONS

Hydrochlorothiazide 12.5 mg/day, when added to background ACE inhibitor therapy with fosinopril in hypertensive diabetic patients, resulted in a metabolic profile that was similar, if not superior on certain parameters, in comparison with indapamide 2.5 mg/day.

The usefulness of antioxidative enzymes for the estimation of synthetic effects of PGE1 analogue

The aim of our research was estimation of the activity of superoxide dysmutase (SOD) and glutathione peroxidase (GPx) in rabbits' blood after administration of single dose of carbon tetrachloride (CCl4) and synthetic analogue PGE1 - Cytotec. The research was carried out on 56 Chinchilla rabbits. By means of stomach tube rabbits were administered respectively: CCl4, Cytotec, CCl4 with Cytotec, indomethacin, Cytotec with indomethacin and CCl4 with Cytotec and indomethacin simultneously. In comparison with control group almost double increase of SOD activity was stated at rabbits which were administered CCl4 and CCl4 with indomethacin. At rabbits which were administered CCl4 with Cytotec and CCl4 with Cytotec and with indomethacin, the SOD activity increased by only 50% in comparison with control group. At rabbits in whose blood the SOD activity increased, the activity of GPx decreased on average by respectively 40% and 15%. The stated changes of SOD and GPx activity in rabbits' blood which were administered prostaglandin apart from CCl4 indicates prostaglandin's indirect interference into hepatocytes antioxidative system and thus its hepatoprotective activity.

Air pollution and acute respiratory diseases in children: regression analysis of morbidity data

The aim of this study was to investigate the relationship between acute respiratory diseases and the air quality in the urban area of the Upper Silesian Industrial Zone during autumn and winter with special emphasis on temporal variability in the air concentrations of pollutants. The survey was carried out in 5 primary care units in Chorzów where the morbidity data on the selected respiratory diseases were collected from 1 November 1992 to 31 March 1993. The air pollution data were obtained from the monitoring station, being a part of the Sanitary and Epidemiological Station Network. Regression analysis with mean values of concentrations of air pollutants as explanatory variables revealed a positive effect of combined suspended particulate matter and SO2 concentration on the increased prevalence of bronchitis and bronchiolitis. Similar and even stronger effect was observed at the level of temporal variability coefficients of the air pollutants. A hypothesis that temporal variability of the air concentration of pollutants might be a more relevant factor for determining the prevalence of respiratory diseases than simple mean values of the pollutant concentrations is very interesting worthy of further investigations.

Asymmetry pays: visual lateralization improves discrimination success in pigeons

Functional cerebral asymmetries, once thought to be exclusively human, are now accepted to be a widespread principle of brain organization in vertebrates [1]. The prevalence of lateralization makes it likely that it has some major advantage. Until now, however, conclusive evidence has been lacking. To analyze the relation between the extent of cerebral asymmetry and the degree of performance in visual foraging, we studied grain-grit discrimination success in pigeons, a species with a left hemisphere dominance for visual object processing [2,3]. The birds performed the task under left-eye, right-eye or binocular seeing conditions. In most animals, right-eye seeing was superior to left-eye seeing performance, and binocular performance was higher than each monocular level. The absolute difference between left- and right-eye levels was defined as a measure for the degree of visual asymmetry. Animals with higher asymmetries were more successful in discriminating grain from grit under binocular conditions. This shows that an increase in visual asymmetry enhances success in visually guided foraging. Possibly, asymmetries of the pigeon's visual system increase the computational speed of object recognition processes by concentrating them into one hemisphere while preventing the other side of the brain from initiating conflicting search sequences of its own.

Lateralized interhemispheric transfer of color cues: evidence for dynamic coding principles of visual lateralization in pigeons

Visual feature discrimination tasks in pigeons reveal a right eye/left hemisphere dominance at the population level. Anatomical studies and lesion data show this visual lateralization to be related to asymmetries of the tectofugal system, which ascends from the tectum over the n. rotundus to the forebrain. Anatomically, this system is characterized by numerous morphological and connectional asymmetries which result in a bilateral visual representation in the dominant left hemisphere and a mostly contralateral representation in the subdominant right hemisphere. Ontogenetically, visual lateralization starts with an asymmetrical embryonic position within the egg, which leads to asymmetries of light stimulation. Differences in exposure to light stimulation between the eyes result in activity differences between the ascending tectofugal pathways of the left and the right hemisphere, which are transcribed during a critical time span into morphological asymmetries. The asymmetries established after this transient period finally start to determine the lateralized processes of the visual system for the entire life span of the individual. We now can show that these anatomical lateralizations are accompanied by asymmetries of interocular transfer, which enable a faster shift of learned color cues from the dominant right to the left eye than vice versa. In summary, our data provide evidence that cerebral asymmetries are based both on "static" anatomical and on "dynamic" process-dependent principles.

Pharmacokinetic assessment of oral ganciclovir in lung transplant recipients with cystic fibrosis

Oral ganciclovir has been used as prophylaxis and therapy against cytomegalovirus in patients with HIV infection and following organ transplantation. Oral ganciclovir has clear practical advantages over intravenous ganciclovir but has a relatively low bioavailability and this may be problematic in at-risk patients with malabsorption. The bioavailability and therefore therapeutic potential of oral ganciclovir in cystic fibrosis (CF) patients post-lung transplant (LT) might be expected to be inadequate given the high incidence of malabsorption in these patients. An 8 h pharmacokinetic study was performed in 12 CF patients 160 +/- 122 days post-transplant who had been taking 1 g oral ganciclovir tds for 3 days with food (plus normal enzyme supplements). Mean (range) serum creatinine was 150 Imol/L (70-280). Blood was sampled at 0.5, 1, 2, 3, 4, 6 and 8 h post-final dose. Plasma was stored at -20 degrees C and later analysed by highperformance liquid chromatography. Mean peak concentration (C(max)) was 4.8 mg/L (0. 96-12.8), mean minimum concentration (C(min)) was 3.6 mg/L (0.78-11. 7) and mean area under the curve (AUC) was 35.4 mg.8 h/L (8-99). C(max), C(min) and AUC correlated significantly with one another (P < 0.001) as well as with serum creatinine and creatinine clearance (P < 0.01). When corrected for alterations in renal function, plasma oral ganciclovir levels are as predicted for other transplant populations. Three days of oral ganciclovir results in therapeutically useful plasma drug levels in the CF LT population, despite a background of general malabsorption. C(max), C(min) and AUC are highly correlated, allowing for the possibility of steady-state drug monitoring to confirm that the recommended dosing algorithm produces appropriate plasma levels.

Stability assessment of ketoconazole in aqueous formulations

Ketoconazole is an imidazole antifungal agent. It has a wide antifungal spectrum and possesses some antibacterial activity. In inappropriate formulations, especially in aqueous media, ketoconazole molecules may be unsteady. The stability of ketoconazole in aqueous media was assessed as a function of pH, antioxidant and ketoconazole concentrations. It was found that ketoconazole was least stable at pH 1 among the pH values studied (pH 1-9). Since the major degradation pathway was specific acid catalysis, based upon the transition-state theory, the entropy (DeltaS) of the activation was calculated and found to be negative indicating that the activated complex was more constrained than the individual species. The free energy of activation (DeltaG) was estimated to be 30 kcal mol(-1). The viscosity of the formulation was found to be more stable at high pH because carbopol is stable at basic pH and protected ketoconazole. It appears that the amount of ketoconazole in the formulation has a low influence on the degradation mechanisms. The increase of the butylated hydroxytoluene antioxidant levels from 0.05 to 0.4%, adversely affected the stability of ketoconazole. In conclusion, the expected shelf life of the final ketoconazole formulation (pH 7, 0.1% butylated hydroxytoluene) was 15 months.

Evaluation of 8-oxodeoxyguanosine, typical oxidative DNA damage, in lymphocytes of ozone-treated arteriosclerotic patients

In the present study we measured the amount of 8-oxo-2'-deoxyguanosine (8-oxo-dG) in DNA isolated from lymphocytes of arteriosclerotic patients undergoing ozonetherapy. Treatment of the patients with therapeutic concentration of ozone caused a significant increase over the control value in the amount of 8-oxo-dG of DNA isolated from their lymphocytes. However, only three out of six patients examined responded positively to the treatment in terms of the base damage. The increases varied among patients, and were in the range of 100-450%. This interindividual difference may at least be partly explained by recently demonstrated heritable susceptibility to ozone.