Investigation of Dissolution Behavior HPMC/Eudragit<Superscript>®</Superscript>/Magnesium Aluminometasilicate Oral Matrices Based on NMR Solid-State Spectroscopy and Dynamic Characteristics of Gel Layer

Burst drug release is often considered a negative phenomenon resulting in unexpected toxicity or tissue irritation. Optimal release of a highly soluble active pharmaceutical ingredient (API) from hypromellose (HPMC) matrices is technologically impossible; therefore, a combination of polymers is required for burst effect reduction. Promising variant could be seen in combination of HPMC and insoluble Eudragits^® as water dispersions. These can be applied only on API/insoluble filler mixture as over-wetting prevention. The main hurdle is a limited water absorption capacity (WAC) of filler. Therefore, the object of this study was to investigate the dissolution behavior of levetiracetam from HPMC/Eudragit^®NE matrices using magnesium aluminometasilicate (Neusilin^® US2) as filler with excellent WAC. Part of this study was also to assess influence of thermal treatment on quality parameters of matrices. The use of Neusilin^® allowed the application of Eudragit^® dispersion to API/Neusilin^® mixture in one step during high-shear wet granulation. HPMC was added extragranularly. Obtained matrices were investigated for qualitative characteristics, NMR solid-state spectroscopy (ssNMR), gel layer dynamic parameters, SEM, and principal component analysis (PCA). Decrease in burst effect (max. of 33.6%) and dissolution rate, increase in fitting to zero-order kinetics, and paradoxical reduction in gel layer thickness were observed with rising Eudragit^® NE concentration. The explanation was done by ssNMR, which clearly showed a significant reduction of the API particle size (150–500 nm) in granules as effect of surfactant present in dispersion in dependence on Eudragit^®NE amount. This change in API particle size resulted in a significantly larger interface between these two entities. Based on ANOVA and PCA, thermal treatment was not revealed as a useful procedure for this system.     

Efficacy of the new repellent BioUD<Superscript>®</Superscript> against three species of ixodid ticks

BioUD ^® with the active ingredient 2-undecanone originally derived from wild tomato plants is a new repellent recently registered by the US EPA. Repellent efficacy of BioUD ^® (7.75% 2-undecanone) and DEET (98.11%) was examined in the laboratory using a choice test between repellent-treated and control filter paper surfaces for Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis. BioUD ^® provided greater repellency against A. americanum and I. scapularis than DEET. No difference was found between BioUD ^® and DEET against D. variabilis. In head-to-head assays between BioUD ^® and DEET, undiluted and 50% dilutions of BioUD^® were more repellent than undiluted DEET against all three species tested. Similarly, a 25% dilution of BioUD^® was more repellent than DEET against A. americanum while no difference in mean percentage repellency was found between a 25% dilution of BioUD^® and DEET against I. scapularis. Based on regression analysis, the concentration of BioUD^® required for equivalent repellency to 98.11% DEET was 39.5% for D. variabilis and 29.7% for I. scapularis. A log-probit model could not be constructed for A. americanum from the dosages tested. Based on filter paper head-to-head assays, BioUD^® is at least 2–4 times more active as a repellent than DEET against three species of ixodid ticks under the conditions of our laboratory bioassays.     

Age-related changes in the behavioural response of honeybees to <Emphasis Type="Italic">Apiguard</Emphasis><Superscript>®</Superscript>, a thymol-based treatment used to control the mite <Emphasis Type="Italic">Varroa destructor</Emphasis>

The parasitic mite Varroa destructor is responsible for heavy losses in honey bee colonies and represents a major threat to the beekeeping industry. Essential oils offer an attractive alternative to the use of synthetic chemicals for the control of varroa. Amongst them, thymol appears to be particularly promising. However, treatments using thymol as their active substance, such as the gel formulation Apiguard ^®, are suspected to have adverse effects on honey bee colonies. In this study, laboratory assays are used to investigate the effects of Apiguard ^® exposure on honey bee behaviour. Our results reveal that honey bee responses to this anti-varroa treatment change with honey bee age. While 2-day-old bees respond neutrally to Apiguard ^®, older bees generally avoid the Apiguard ^® gel. Responses of forager bees were particularly striking. Foragers appear to be repelled by Apiguard ^®. Touching their antennae with Apiguard ^® induces robust fanning behaviour. Our data suggest, however, that forager bees exposed to Apiguard ^® in the hive can become habituated to this treatment. These results offer interesting new perspectives on the effects of Apiguard ^® on honey bee behaviour and serve to highlight age-related changes in honey bee responses to gustatory, as well as olfactory cues.     

Toothbrush Contamination by <Emphasis Type="Italic">Candida</Emphasis> spp. and Efficacy of Mouthrinse Spray for Their Disinfection

The aim of the study was to evaluate toothbrush contamination in vivo by Candida spp. and the efficacy of Periogard^® and Neem Sattiva^®, in spray, in the disinfection of these toothbrushes. This study was performed in three phases in which mouthrinses and sterile distilled water (control group) were sprayed six times on toothbrush bristles used by 61 university students. Toothbrushes were then submitted to microbiological processing for the isolation and identification of Candida species. Fifty-nine students completed the three phases of this study, and 22 (37.3%) control group toothbrushes presented growth of Candida species. Periogard^® and Neem Sattiva^® eliminated growth of Candida spp. in 48.1 and 7.4% of toothbrushes, respectively. Contamination by Candida spp. was observed on various toothbrushes of the control group. Periogard^® was more efficacious than Neem Sattiva^® in eliminating growth of Candida spp. on the toothbrush bristles.     

Effects of adjuvant and conidial concentration on the efficacy of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> for the control of the two spotted spider mite, <Emphasis Type="Italic">Tetranychus urticae</Emphasis>

Greenhouse experiments were conducted on various crops (cucumber, tomato, eggplant, green bean) to ascertain the effects of Break-thru^® (polyether-polymethylsiloxane-copolymer, a silicone surfactant) and an oil emulsion, on Beauveria bassiana (Balsamo) Vuillemin (Bb) applications for the control of the two spotted spider mite, Tetranychus urticae Koch. The objectives were to compare a) the efficacy of Bb control when applied in aqueous Break-thru^® or an oil emulsion; b) the effects of various concentrations of Bb conidia, as affected by each surfactant; and c) the effects of Break-thru^® on the activity of the fungus. Conidia were suspended either in an aqueous Break-thru^® or an emulsifiable formulation at different conidial concentrations (1.05 × 10⁶, 2.1 × 10⁶ and 4.2 × 10⁶ conidia ml^?1) and sprayed onto leaves 2 weeks after artificial pest inoculation. Two sprays were performed, with an interval of one week from one spray to another, and T. urticae population counts (both motile and egg stages) were made on plant leaves 7 days after each spray. Bb conidia in Break-thru^® were more efficacious than conidia in emulsifiable formulation. With the highest rate of conidia (4.2 × 10⁶ conidia ml^?1), mortality of adult mites ranged from 60 ± 4.2 (mean ± SE) to 85.7 ± 4.3% in the Break-thru^® suspension and 39.4 ± 7 to 61.3 ± 6% in the oil emulsion. Leaf damage index was also substantially reduced from 70% in the unsprayed control to 40% by the application of Bb conidia at the highest rate with Break-thru^®. Break-thru^® can be combined with Bb in the integrated management of T. urticae and Isolate R444 is a promising candidate for the control of the pest.     

The Development of Self-nanoemulsifying Liquisolid Tablets to Improve the Dissolution of Simvastatin

The aim of this work was to develop self-nanoemulsifying liquisolid tablets (SNELT) to enhance the dissolution profile of poorly water-soluble simvastatin. SNELT present a unique technique of incorporating self-nanoemulsifying drug delivery systems (SNEDDS) into tablets. Optimized SNEDDS containing different oils, Cremophor^® RH 40 (surfactant) and Transcutol^® HP (co-surfactant), at different ratios, were used as liquid vehicles and loaded on carrier material, microcrystalline cellulose (MCC), and coating material, Cab-o-sil^® H-5 (nanosize colloidal silicon dioxide) powders at different loading factors (L _f ) and fixed excipient ratio (R?=?20). The effect of using different carrier materials, granulated mannitol, crystalline mannitol, and maltodextrin with MCC at different ratios, and different coating materials, Aeroperl^® 300 (granulated silicon dioxide) at different excipient ratios (R), was also emphasized. Liquisolid powders with acceptable flowability, compressibility, and tablet weight were compressed into tablets. Results revealed that powders with L _f ?=?0.2 possessed the most preferable properties to be tableted. SNELT with MCC and Cab-o-sil^® H-5 were able to generate nanoemulsions and to enhance the cumulative percent of drug dissolved at 60 min significantly to reach up to 90%. Furthermore, using carrier material (granulated mannitol/MCC at ratio 3:1) enabled SNELT to disperse into nanoemulsion (Z-average?=?25.7 nm) and improved the dissolution profile significantly to reach 99% at 60 min. Cab-o-sil^® H-5 proved to be a better coating material compared to Aeroperl^® 300. In conclusion, developed SNELT were promising in enhancing in vitro dissolution of simvastatin and excipients highly affect SNELT’s performance.     

Effect of a Probiotic Intake on Oxidant and Antioxidant Parameters in Plasma of Athletes During Intense Exercise Training

The aim of this study was to evaluate the effect of Lactobacillus rhamnosus IMC 501^® and Lactobacillus paracasei IMC 502^® on oxidative stress in athletes during a four-week period of intense physical activity. Two groups of twelve subjects each were selected for this analysis. The first group consumed a daily dose of a mixture of the two probiotic strains (1:1 L. rhamnosus IMC 501^® and L. paracasei IMC 502^®; ~10⁹ cells/day) for 4 weeks. The second group (control) did not consume any supplements during the 4 weeks. Blood samples collected immediately before and after the supplementation were analyzed, and plasma levels of reactive oxygen metabolites and biological antioxidant potential were determined. Faeces were also collected and analyzed before and at the end of the probiotic supplementation. Antioxidative activity and oxidative stress resistance of the two strains were determined in vitro. Results demonstrated that intense physical activity induced oxidative stress and that probiotic supplementation increased plasma antioxidant levels, thus neutralizing reactive oxygen species. The two strains, L. rhamnosus IMC 501^® and L. paracasei IMC 502^®, exert strong antioxidant activity. Athletes and all those exposed to oxidative stress may benefit from the ability of these probiotics to increase antioxidant levels and neutralize the effects of reactive oxygen species.     

Seaweed-Derived Biostimulant (Kelpak<Superscript>®</Superscript>) Influences Endogenous Cytokinins and Bioactive Compounds in Hydroponically Grown <Emphasis Type="Italic">Eucomis autumnalis</Emphasis>

The effect of a seaweed-derived biostimulant (Kelpak^® at 1, 2.5 and 5 % dilution; v/v) on the growth, endogenous cytokinin (CK) and phytochemical content in Eucomis autumnalis (Mill.) Chitt. under hydroponic conditions was evaluated. After 4 months, the stimulatory effect of Kelpak^® treatments was more noticeable in the underground organs than in the aerial organs. Total endogenous CK was also higher in plants treated with Kelpak^® (c.a. 1000–1200 pmol g^?1 DW) compared to control plants (860 pmol g^?1 DW). Isoprenoid CKs (which mainly accumulated in the aerial organs) were more dominant than aromatic-type CKs across all the treatments. A total of 11 bioactive chemicals (8 phenolic acids and 3 flavonoids) and eucomic acid known for their diverse biological activities were quantified in the samples. The most abundant compound was p-coumaric acid (6.5 µg g^?1 DW) and it was approximately sevenfold higher in 2.5 % Kelpak^®-treated plants than in the control. It was also noteworthy that syringic acid only occurred in the underground organs of 5 % Kelpak^®-treated plants. Eucomic acid which is a major bioactive compound in E. autumnalis was significantly enhanced in Kelpak^® treatments, and the leaves accounted for more than 70 % of the overall content. Thus, Kelpak^® elicited a significant influence on the growth, endogenous CK and phytochemical content in E. autumnalis. These findings provide additional evidence of the enormous potential of Kelpak^® as a useful biostimulant with practical applications in various agricultural endeavours.     

Importance of Molecular Methods to Determine Whether a Probiotic is the Source of <Emphasis Type="Italic">Lactobacillus</Emphasis> Bacteremia

There has been an increasing interest in the use of probiotic products for the prevention of Clostridium difficile infection (CDI). Bio-K+^® is a commercial probiotic product comprising three strains of lactobacilli—Lactobacillus acidophilus CL1285^®, Lact. casei LBC80R^® and Lact. rhamnosus CLR2^®—that have been applied to prevent CDI. Generally considered as safe, lactobacilli have potential to cause bacteremia, endocarditis and other infections. The source of Lactobacillus bacteremia can be normal human flora or lactobacilli-containing probiotic. The aim of this study was to assess whether probiotic lactobacilli caused bacteremia and to show the value of molecular identification and typing techniques to determine probiotic and patient strain relatedness. We report an episode of Lactobacillus bacteremia in a 69-year-old man admitted to a hospital with severe congestive heart failure. During his hospitalization, he required long-term antibiotic therapy. Additionally, the patient received Bio-K+^® probiotic as part of a quality improvement project to prevent CDI. Subsequently, Lactobacillus bacteremia occurred. Two independent blinded laboratory evaluations, using pulse field gel electrophoresis, 16S rRNA gene sequencing and DNA fingerprint analysis (rep-PCR), were performed to determine whether the recovered Lact. acidophilus originated from the probiotic product. Ultimately, the patient strain was identified as Lact. casei and both laboratories found no genetic relation between the patient’s strain and any of the probiotic lactobacilli. This clinical case of lactobacillus bacteremia in the setting of probiotic exposure demonstrates the value of using discriminatory molecular methods to clearly determine whether there were a link between the patient’s isolate and the probiotic strains.     

Characterization of a field-grown transgenic pineapple clone containing the genes <Emphasis Type="Italic">chitinase</Emphasis>, <Emphasis Type="Italic">AP24</Emphasis>, and <Emphasis Type="Italic">bar</Emphasis>

We previously introduced the bar gene, along with chitinase and AP24 genes, into the pineapple genome. The present report focuses on the evaluation of the first vegetative generation of a transgenic clone containing these genes. Three materials were compared: macropropagated controls (non-transformed), micropropagated controls (non-transformed), and micropropagated transformed plants. From each group, 50% of the plants were sprayed with FINALE^® 3 mo after the experiment initiation. The characterization was performed after 1 yr of field growth. FINALE^® killed all non-transgenic plants. Plants that survived the herbicide application showed 2n?=?50 chromosomes in their roots after 1 yr in the field. Micropropagated transformed plants sprayed with FINALE^® did not show phenotype differences from micropropagated transformed plants not sprayed with the herbicide. Between the micropropagated transformed plants sprayed with FINALE^® and the micropropagated control plants, the following differences were observed: modifications in levels of cell wall-linked, free and total phenolics, and total proteins. Moreover, changes of the fruit mass without crown were also recorded. Between the micropropagated transformed plants sprayed with FINALE^® and the macropropagated control plants, levels of chlorophyll b, total chlorophyll pigments, and proteins were different. Furthermore, activities of phenylalanine ammonia-lyase, superoxide dismutase, and glutamine synthetase were dissimilar. The plant height and diameter, and the crown height were also different. Until now, we have evaluated transformed pineapple plants during hardening and field growth. Although some unexpected variations were recorded, we believe they are not relevant enough to justify rejection of transgenesis as an important tool for pineapple genetic improvement.     

Growth dynamics of juvenile loggerhead sea turtles undergoing an ontogenetic habitat shift

Ontogenetic niche theory predicts that individuals may undergo one or more changes in habitat or diet throughout their lifetime to maintain optimal growth rates, or to optimize trade-offs between mortality risk and growth. We combine skeletochronological and stable nitrogen isotope (δ¹⁵N) analyses of sea turtle humeri (n = 61) to characterize the growth dynamics of juvenile loggerhead sea turtles (Caretta caretta) during an oceanic-to-neritic ontogenetic shift. The primary objective of this study was to determine how ontogenetic niche theory extends to sea turtles, and to individuals with different patterns of resource use (discrete shifters, n = 23; facultative shifters n = 14; non-shifters, n = 24). Mean growth rates peaked at the start of the ontogenetic shift (based on change in δ¹⁵N values), but returned to pre-shift levels within 2 years. Turtles generally only experienced 1 year of relatively high growth, but the timing of peak growth relative to the start of an ontogenetic shift varied among individuals (before, n = 14; during, n = 12; after, n = 8). Furthermore, no reduction in growth preceded the transition, as is predicted by ontogenetic niche theory. Annual growth rates were similar between non-transitioning turtles resident in oceanic and neritic habitats and turtles displaying alternative patterns of resource use. These results suggest that factors other than maximization of size-specific growth may more strongly influence the timing of ontogenetic shifts in loggerhead sea turtles, and that alternative patterns of resource use may have limited influence on somatic growth and age at maturation in this species.     

On the cause of variability of the cosmic ray spectrum in the knee region

Cosmic ray (CR) energy spectra for H, He, Si, and Fe nuclei with energy-to-charge number ratios ?/Z in the range from 10 to 5 × 10⁷ GeV are studied using observational data obtained at different times in different energy ranges: AMS-02, CREAM, Tibet ASγ, Tibet (hybrid), GRAPES-3, KASCADE, and KASCADE-Grande. Comparison of the H and He CR fluxes according to the KASCADE and KASCADE-Grande data (for different models of deconvolving CR spectra) with the Tibet ASγ and Tibet (hybrid) data obtained at another time in the range of ?/Z ～ 3 × 10⁶ GeV demonstrates space weather-caused variability of the CR flux. This feature of CR energy spectra in the Tibet ASγ data is most clearly observed in the spectra of heavier nuclei (Si and Fe) according to the KASCADE-Grande and GRAPES-3 data. The variability in the energy spectra of all CRs in the vicinity of the “knee” is shown in the data of Yakutsk EAS, CASA-BLANCA, and Tibet-III experiments. The variability of the CR flux on a time scale on the order of several years exists only if the source corresponding to the peak in the energy spectrum is situated at a distance of no more than 1 pc from the Sun. Rapid surfatron acceleration of CRs may result from colliding interstellar clouds nearest to the Sun (LIC and G). This acceleration mechanism allows one to explain the variability of the CR spectrum in the range 10³ GeV < ?/Z < 10⁸ GeV. Conditions for the trapping of strongly relativistic Fe nuclei by an electromagnetic wave, the dynamics of the components of the particle velocity and momentum, and the dependence of the particle acceleration rate on the initial parameters of the problem are analyzed using numerical calculations. The structure of the phase plane of the accelerated Fe nuclei is examined. Optimal conditions for the implementation of ultrarelativistic surfatron acceleration of Fe nuclei by an electromagnetic wave are formulated.     

Performance evaluation of a rapid whole-blood immunoassay for the detection of IgG antibodies against <Emphasis Type="Italic">Helicobacter pylori</Emphasis> in daily clinical practice

Background

A growing number of rapid Helicobacter pylori antibody tests are commercially available now, however, some of these tests are often used without sufficient evaluation. The aim of this study was to evaluate the performance of a commercially available rapid whole-blood immunoassay (gabControl^® H. pylori; gabmed GmbH, Köln, Germany), for the qualitative detection of IgG antibodies against H. pylori with the ¹³C-urea breath test (¹³C-UBT) serving as a reference method.

Methods

A total of 108 consecutive outpatients, who were referred for ¹³C-UBT by general practitioners and specialists, were also tested for H. pylori infection by the gabControl^® H. pylori immunoassay. The clinical performance of this rapid whole-blood test was evaluated by determining the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) compared to the ¹³C-UBT. The agreement between the two tests was calculated using Cohen’s Kappa (κ) with 95 % confidence intervals (CI).

Results

The agreement between the gabControl^® H. pylori assay and the ¹³C-UBT was 0.62 [95 % confidence intervals (CIs) 0.47–0.76; P < 0.001]. With the ¹³C-UBT serving as the non-invasive gold standard method of H. pylori diagnosis, the gabControl^® H. pylori assay demonstrated a sensitivity and specificity of 91.4 and 76.7 %, respectively, with a PPV of 65.3 % and a NPV of 94.9 %. Seventeen (15.7 %) individuals with a positive H. pylori anamnesis showed a negative ¹³C-UBT and were typed positive by the gabControl^® H. pylori assay. Of these, 13 (76.5 %) and 3 individuals (17.6 %) had completed one and two eradication therapies, respectively.

Conclusions

The gabControl^® H. pylori immunoassay is a rapid and easy to use first line screening tool for H. pylori IgG antibody detection in daily clinical practice. However, this assay should not be used for confirmation of the successful H. pylori eradication after antibiotic treatment.

     

Light-activated cytotoxic compounds from Malaysian microorganisms for photodynamic therapy of cancer

Photodynamic therapy (PDT) is a promising cancer treatment which involves activation of a photosensitizing drug with light to produce reactive oxygen species that kill tumors without causing damage to unirradiated normal tissues. To date, only Photofrin^®, Foscan^® and Levulan^® have been approved for clinical treatment of cancer. Tropical habitats such as those found in Malaysia are attractive sources of new therapeutic compounds as tremendous chemical diversity is found in a large number of plants, animals, marine- and micro-organisms. In our screening program for novel photosensitizers from nature, colorful strains of fungi (from Aspergillus and Penicillium genus) and bacteria (including actinomycetes and photosynthetic bacteria) were collected from various habitats in Peninsular Malaysia, such as coastal soil, peat soil, marine sponges and wastewater ponds. Methanolic extracts from a total of 85 different species were evaluated with a short-term cell viability assay for photo-cytotoxicity, where a promyelocytic leukemia cell-line, HL60 incubated with 20 μg/ml of extracts was irradiated with 9.6 J/cm² of a broad spectrum light. Two of these extracts, one from Rhodobacter sphaeroides (PBUM003) and one from Rhodopseudomonas palustris (PBUM001) showed moderate to strong photo-cytotoxicity. Subsequent bioassay guided isolation of the PBUM001 extract yielded known photosensitisers that are based on bacteriochlorophyll-a by comparing their molecular weight data, HPLC profiles and UV–vis absorption spectra with literature values, thereby demonstrating the validity of our screening approach.     

Water polluted with glyphosate formulations: effectiveness of a decontamination process using <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> growing as bioindicator

The environmental pollution caused by pesticides is considered a major problem worldwide. Glyphosate is one of the herbicides most widely used, and its use has increased sharply in the last years. In this work, the toxicity of four commercial glyphosate formulations (Eskoba^®, Panzer Gold^®, Roundup Ultramax^® and Sulfosato Touchdown^®) was assessed by determining the median effective concentration at 96 h (96 h-EC₅₀) using the microalga Chlorella vulgaris as the biological model. Although the formulations tested are moderately to slightly toxic to C. vulgaris according to the World Health Organization’s toxicity categories for aquatic and terrestrial organisms, this research shows that the four formulations are toxic, with Eskoba^® the least toxic and Roundup Ultramax^® the most toxic one. A UV/H₂O₂ remediation process for the detoxification of the samples was tested also. Its effectiveness was evaluated using a C. vulgaris growth inhibition test. Growth inhibition of C. vulgaris did not reach 18.2 %, indicating the efficacy of the UV/H₂O₂ remediation process to reduce glyphosate toxicity. In some of the samples tested within the first 48 h of the assay, C. vulgaris growth was even increased. The results of the present work suggest that the selected species was a good indicator to determine the toxicity level of glyphosate formulations and shows the relevance of the ecotoxicological tests to evaluate a physicochemical remediation process.     

Using a flexible shaft agitator to enhance the rheology of a complex fungal fermentation culture

The rheology behavior of biological fluids particularly when the viscosity is high and rheology is complex, is an important issue to understand, particularly for studies in mass-transfer and for solving technical problems with mixing in stirred bioreactors. In this paper, the use of a Swingstir^® impeller during the fermentation of Aspergillus oryzae resulted in decreases from the parameters of a power-law model, in viscosity and in the thixotropic behavior of a cultivation broth. The results showed that both the K _L a and the alpha amylase activity were improved when using the Swingstir^® in comparison with Fullzone^® impeller (FZ) at the same level of energy consumption. Increasing the pellet porosity during mixing via the Swingstir^® resulted in increases in oxygen mass transfer and the average shear stress.     

Color measurements as a reliable method for estimating chlorophyll degradation to phaeopigments

The application of biocides is a traditional method of controlling biodecay of outdoor cultural heritage. Chlorophyll degradation to phaeopigments is used to test the biocidal efficacy of the antimicrobial agents. In the present study, the usefulness of color measurements in estimating chlorophyll degradation was investigated. An aeroterrestrial stone biofilm-forming cyanobacterium of the genus Nostoc was chosen as test organism, comparing its different behaviour in both planktonic and biofilm mode of growth against the isothiazoline biocide Biotin T^®. Changes in A_435 nm/A_415 nm and A_665 nm/A_665a nm and in the chlorophyll a and adenosine triphosphate (ATP) cell content were compared with the variations in the CIELAB color parameters (L*, a*, b*, C*_ab and h_ab). Our findings showed that both the phaeophytination indexes are useful in describing degradation of chlorophyl a to phaeopigments. Moreover, the CIELAB color parameters represented an effective tool in describing chlorophyll degradation. L* CIELAB parameter appeared to be the most informative parameter in describing the biocidal activity of Biotin T^® against Nostoc sp. in both planktonic and biofilm mode of growth.     

Optimization of <Emphasis Type="Italic">Curcuma</Emphasis> Oil/Quinine-Loaded Nanocapsules for Malaria Treatment

Quinine, a treatment used in chloroquine-resistant falciparum malaria, was loaded into poly(?-caprolactone) or Eudragit^® RS100 nanocapsules using Curcuma oil as the oil-based core. Until now, the effect of cationic nanocapsules on malaria has not been reported. A 2⁴ factorial design was adopted using, as independent variables, the concentration of Curcuma oil, presence of quinine, type of polymer, and aqueous surfactant. Diameter, zeta potential, and pH were the responses studied. The formulations were also evaluated for drug content, encapsulation efficiency, photostability, and antimalarial activity against Plasmodium berghei-infected mice. The type of polymer influenced all of the responses studied. Quinine-loaded Eudragit^® RS100 (F13) and PCL nanocapsules (F9), both with polysorbate 80 coating, showed nanometric particle size, positive zeta potential, neutral pH, high drug content, and quinine photoprotection ability; thus, these nanocapsules were selected for in vivo tests. Both formulations showed lower levels of parasitemia from the beginning of the experiment (5.78 ± 3.60 and 4.76 ± 3.46% for F9 and F13, respectively) and highest survival mean time (15.3 ± 2.0 and 14.9 ± 5.6 days for F9 and F13, respectively). F9 and F13 showed significant survival curve compared to saline, thus demonstrating that nanoencapsulation improved bioefficacy of QN and co-encapsulated curcuminoids, regardless of the surface charge.     

Report of a Scientific Working Group on Serious Adverse Events following Mectizan<Superscript>®</Superscript> treatment of onchocerciasis in <Emphasis Type="Italic">Loa loa</Emphasis> endemic areas

The occurrence of Serious Adverse Experiences (SAEs) following Mectizan^® treatment of onchocerciasis in Loa loa endemic areas has been increasingly reported over the past decade. These SAEs include a severely disabling, and potentially fatal, encephalopathy, which appears to correlate with a high load of L. loa microfilariae (> 30,000 mf/ml).Previous consultations organized by the Mectizan^® Donation Program (MDP) in 1995 and 1999 have developed useful "case" definitions of encephalopathic SAEs following Mectizan^® treatment and have summarized available evidence on its pathogenesis and optimal clinical management. At both meetings, the need for better understanding of the pathogenesis of the encephalopathy was emphasized, including the need for biological and autopsy specimens from the affected cases.Following a recommendation at the Joint Action Forum of the African Programme for Onchocerciasis Control in December 2001, the MDP, on behalf of the Mectizan^® Expert Committee, organized a Scientific Working Group on L. loa associated SAEs following Mectizan^® treatment in May 2002. The present report includes the background, new evidence, conclusions and recommendations from that Scientific Working Group. The following points represent a summary of the present status:1. Although there are more and better quality clinical and epidemiological data on L. loa, the pathogenesis of the Mectizan^®-related L. loa encephalopathy remains obscure.2. Very limited progress has been made in research on the pathogenesis of encephalopathy, because of the lack of specimens from cases, and the lack of animal models.3. There has been no particular breakthrough in terms of the medical management of patients with L. loa encephalopathy; however, a favorable outcome usually results from prompt general nursing and nutritional care which remain the major interventions.The main recommendations for future actions are as follows:1. Validate and update the mapping of L. loa with a combination of remote sensing and RAPLOA techniques.2. Conduct an expert analysis of the apparent clustering of encephalopathic SAEs reported so far.3. Investigate a possible "pre-treatment" scheme with high-dose albendazole in L. loa endemic communities at high risk of encephalopathic SAEs if treated with Mectizan^®; this study will be conducted in collaboration with WHO/TDR.4. Establish a post of Loiasis Technical Advisor for research and operational support in Cameroon, to conduct population surveys and to facilitate better data collection from SAE cases, including postmortem studies as appropriate.5. Investigate the possibility of developing an animal model of L. loa encephalopathy; this activity would be linked to the above-mentioned research agenda in Cameroon.6. Investigate the best care model for encephalopathic SAEs, including identification of early warning signs and therapeutic interventions.7. Develop further models for health education messages needed for community compliance with Mectizan^® treatment, and family support for SAE cases.8. Conduct research studies on the safety of combination therapy of Mectizan^® and albendazole in areas co-endemic for L. loa and lymphatic filariasis (LF) with coordination from the relevant technical bodies that oversee these issues.The above recommendations will be implemented through a continuing collaboration between the interested parties represented at the Scientific Working Group, involved in onchocerciasis control and/or the Global Programme to Eliminate Lymphatic Filariasis.     

Decolorization of textile dye RB19 using volcanic rock matrix immobilized <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> cells with surface displayed laccase

A triplicate volcanic rock matrix–Bacillus thuringiensis–laccase WlacD (VRMs–Bt–WlacD) dye decolorization system was developed. WlacD was displayed on the B. thuringiensis MB174 cell surface to prepare a whole-cell laccase biocatalyst by using two repeat N-terminal domains of autolysin Mbg (Mbgn)₂ as the anchoring motif. Immunofluorescence microscopic assays confirmed that the fusion protein (Mbgn)₂–WlacD was anchored on the surface of the recombinant B. thuringiensis MB174. After optimization by a single factor test, L ₉(3⁴)-orthogonal test, Plackett–Burman test, steepest ascent method, and Box–Behnken response surface methodology, the whole-cell specific laccase activity of B. thuringiensis MB174 was improved to 555.2 U L^?1, which was 2.25 times than that of the primary culture condition. Optimized B. thuringiensis MB174 cells were further adsorbed by VRMs to prepare VRMs–Bt–WlacD, an immobilized whole-cell laccase biocatalyst. Decolorization capacity of as-prepared VRMs–Bt–WlacD toward an initial concentration of 500 mg L^?1 of an textile dye reactive blue 19 (RB19) aqueous solution reached 72.36% at a solid-to-liquid ratio of 10 g–100 mL. Repeated decolorization-activation operations showed the high decolorization capacity of VRMs–Bt–WlacD and have the potential for large-scale or continuous operations.