In vitro study of the modulatory effects of heat-killed bacterial biomass on aquaculture bacterioplankton communities

Recent studies have shown that the addition of non-viable microbial biomass or their components (postbiotics) to fish feed can modulate the gut microbiome and positively influence fish health in aquaculture systems. However, no information was hitherto available on the use of non-viable microbial biomass to manipulate aquaculture bacterioplankton communities. To fill this gap, here we used an in vitro model to assess the effects of heat-killed biomasses of an antagonistic strain Pseudoalteromonas rubra SubTr2 and a non-antagonist strain Escherichia coli DH5α on bacterioplankton communities of a recirculating aquaculture system (RAS). Our results showed that these biomasses can have generalist and species-specific effects on aquaculture bacterioplankton structure and function. In addition, they enriched the abundance of bacterial predators, reduced bacterial load and potentially influenced nutrient cycling and pathogen development in aquaculture water. Despite its preliminary nature, for the first time, this study showed that heat-killed microbial biomass has potential application as an in situ modulator of bacterioplankton in aquaculture systems.

Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - A multiparameter spermiotoxicity approach

Nanoparticles (NP) are potentially reprotoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO₂: 10 to 10,000 μg·L^-1) and silver NP (Ag: 0.25 to 250 μg·L^-1) on the sperm of gilthead seabream (Sparus aurata). We performed short-term direct exposures (ex vivo) and evaluated sperm motility, head morphometry, mitochondrial function, antioxidant responses and DNA integrity. No alteration in sperm motility (except for supra environmental Ag NP concentration), head morphometry, mitochondrial function, and DNA integrity occurred. However, depletion of all antioxidants occurred after exposure to TiO₂ NP, whereas SOD decreased after exposure to Ag NP (lowest and intermediate concentration). Considering our results, the decrease in antioxidants did not indicate vulnerability towards oxidative stress. TiO₂ NP and Ag NP induced low spermiotoxicity, without proven relevant ecological impacts.

Cell-assembled extracellular matrix (CAM): a human biopaper for the biofabrication of pre-vascularized tissues able to connect to the host circulationin vivo

When considering regenerative approaches, the efficient creation of a functional vasculature, that can support the metabolic needs of bioengineered tissues, is essential for their survival after implantation. However, it is widely recognized that the post-implantation microenvironment of the engineered tissues is often hypoxic due to insufficient vascularization, resulting in ischemia injury and necrosis. This is one of the main limitations of current tissue engineering applications aiming at replacing significant tissue volumes. Here, we have explored the use of a new biomaterial, the cell-assembled extracellular matrix (CAM), as a biopaper to biofabricate a vascular system. CAM sheets are a unique, fully biological and fully human material that has already shown stable long-term implantation in humans. We demonstrated, for the first time, the use of this unprocessed human ECM as a microperforated biopaper. Using microvalve dispensing bioprinting, concentrated human endothelial cells (30 millions ml^-1) were deposited in a controlled geometry in CAM sheets and cocultured with HSFs. Following multilayer assembly, thick ECM-based constructs fused and supported the survival and maturation of capillary-like structures for up to 26 d of culture. Following 3 weeks of subcutaneous implantation in a mice model, constructs showed limited degradative response and the pre-formed vasculature successfully connected with the host circulatory system to establish active perfusion.This mechanically resilient tissue equivalent has great potential for the creation of more complex implantable tissues, where rapid anastomosis is sine qua non for cell survival and efficient tissue integration.

Stent strategies in left main bifurcation lesions: the simpler, the better?

Introduction

Although percutaneous coronary intervention (PCI) for ostial or midshaft lesions in left main (LM) disease has shown similar results as compared with coronary artery bypass grafting (CABG), distal LM bifurcations are associated with an increase in procedural complexity and higher rates of target lesion revascularization. Several studies have investigated the optimal stenting strategy in patients with coronary bifurcation lesions and showed no benefit for systematic two-stent approach in comparison with provisional stenting. This is reflected in the current guidelines that recommend provisional stenting of the side branch as the preferred approach for most bifurcation lesions. However, there is still debate about the optimal strategy according to lesion location.

Objectives

This analysis aimed to compare the clinical outcomes of LM bifurcation PCI using a provisional strategy versus a two-stent strategy.

Methods

Retrospective, observational study including patients submitted to LM bifurcation (Medina 1,1,1) PCI between January 2010 and December 2019. Data was collected from the emergency department and hospitalization registries. Patients were divided according to the stenting approach. We made a global analysis including baseline clinical and angiographic data. The primary endpoint was target lesion failure (TLF), defined as the composite of myocardial infarction, cardiac death, and target lesion revascularization (TLR). Secondary endpoints included the individual components.

Results

A total of 106 patients were included (median age 74 [66–82], 79 (74.5%) males), 57 (53.8%) submitted to provisional stenting and 49 (46.2%) to a two-stent technique. Baseline characteristics were well matched (table 1). The mean SYNTAX score was 29.6±10.0 and LM stenosis grade was ≥70% in all lesions. Median follow-up was 26.6 [12.0–48.6] months. No differences were found regarding the primary endpoint (TLF in provisional stenting was 21.7% vs 21.4%, HR 2.432; 95% confidence interval, 0.472–12.450; p=0.233.). Although target lesion revascularization within the LM complex was numerically higher in the two-stent group (10.2% vs. 3.5%, p=0.245), the opposite was found in cardiac death (provisional group 10.5% vs. 4.3%, p=0.289).

Conclusions

Besides being a “simpler” technique, provisional stenting had no significant differences in outcomes compared to two-stent techniques. Without further evidence, revascularization strategies should primarily rely on operator expertise.

Funding Acknowledgement

Type of funding sources: None.

Basic life support training with high schools’ teachers in Bahia, Brazil: an experimental study

Background

Early performing of cardiopulmonary resuscitation is the cornerstone of survival in out-of-hospital cardiac arrest, doubling the odds of survival when correctly performed. The American Heart Association and the European Resuscitation Council advocate for training the entire population in order to enable a quick and effective response to out-of-hospital cardiac arrests, improving its outcomes. In primary healthcare settings the health workers can act as trainers, using the family and territorial approach to deliver basic life support (BLS) basis to general population, assuring that key social actors are skilled enough to aid community when needed. This study aims to compare the knowledge and practice skill of high school teachers before and after a BLS training delivered by health workers and students in a primary healthcare setting.

Methods

Teachers of three public high schools in Bahia, Brazil were assessed by a test for theoretical and practical skill in BLS and then trained by a group of primary care workers and students. Training included a 20min lecture and 40min practice session in a simulated scenario. After the training the teachers were assessed with the same test for theoretical and practical skill. A paired-samples T test was used to detect the difference in the mean total score before and after the training, with a significance level of 0.05 (two-sided test) and 95% confidence interval.

Results

The mean total score after the BLS training (8.2 ± 1.5) was significantly higher (p < 0.000) from before training (4.5 ± 1.7).

Conclusions

The high school teachers were unable to deliver proper cardiopulmonary resuscitation before the intervention. Following a BLS training a significant immediate improvement in the knowledge and practical skill was detected. Health workers were able to achieve these results in a primary healthcare setting. Further studies should assess this outcome with larger samples, evaluating the retention of knowledge and skills provided.

Key messages

Basic life support training can be delivered to general population by health workers in primary healthcare settings in order to improve the outcomes to out-of-hospital cardiac arrests. Teachers and health workers can act as key actors in intersetorial health-education initiatives, promoting the health of their communities.

Environmental risk assessment of accidental marine spills: A new approach combining an online dynamic Hazardous and Noxious substances database with numerical dispersion, risk and population modelling

The foreseen rise on maritime transportation of Hazardous and Noxious Substances (HNS) increases the likelihood of accidents, leading to a higher risk of chemical spillage that can have severe ecological impacts. Considering the lack of information on HNS spills, the response to these events is less well established than those involving oil. Moreover, a paramount knowledge of the physicochemical and ecotoxicological properties of the substance involved is required for an effective environmental risk assessment and response to an HNS spill. In the present work, a new online interface, in which a dynamic HNS database feeds a chemical numerical dispersion model, was developed with the aim to improve predictions regarding the behaviour and environmental risk of HNS spills on marine ecosystems. Potential impacts to pelagic organisms were characterized by coupling model outputs with toxicity risk ratios. Furthermore, a simple population model was developed, foreseeing impacts at the ecological level. The integration of the developed tools establishes an innovative framework, which aims to improve predictions related to HNS plumes' behaviour and potential hazards to the marine environment and associated ecosystem services. Further, this new approach fosters an improved preparedness and response to coastal pollution incidents, enhancing effective decision making and management by competent authorities.

Bulk nanobubbles in the mineral and environmental areas: Updating research and applications

In the last decade, the research with bulk nanobubbles (ultrafine bubbles with a diameter <1 μm, according to ISO 20480-1:2017) has been rapidly increasing in the academic and industrial environments. Nowadays, there are many applications reported in the literature, with several patents, procedures, and techniques on nanobubbles generation and an evergrowing research and many applications. Yet, most of those publications reporting bulk nanobubbles generation devices, do not bring information on measurements of size distribution or bubbles concentration (if nanobubbles). Further, there is a problem of scale and many of these products are small bench discontinuous rigs difficult to scale up, which might serve small scale purposes, but are not able for treating high flow-rate wastewaters or minerals pulps at industrial scale. These nanometric bubbles present interesting and peculiar properties such as high surface area per volume unit, high stability and longevity, surface charge in water and the ability to aggregate hydrophobic particles. These findings demonstrate their high potential for applications in many technological areas, which occur not only as isolated bubbles but also jointly with micro (~ 1-100 μm diameter) and/or macrobubbles (~100 μm - 2 mm diameter). This paper reviews the evolution of basic research on nanobubbles, the challenges concerning generation and stability and their applications in the mineral (flotation) and environmental areas (treatment of water and wastewaters or remediation of contaminated environments). Herein, because the importance in engineering, as a whole, most of the studies are based on the nanobubbles generated by depressurisation/hydrodynamic cavitation of the air-saturated water in flow constrictors (venturi, needle valves). In the mineral area, they appear to be responsible for increasing the recovery and flotation kinetics of fine (<74 μm) and ultrafine (<13 μm) particles at lower frother and collector dosages. In the environmental area, nanobubbles have been reported to enhance the removal of a variety of pollutants (emulsified oil, colloidal solids, organic/inorganic precipitates, ions) by flotation associated with bigger bubbles. More, the application of isolated nanobubbles on the removal of residual pollutants, such as amine and oil (both as flocs) were reported. Also, the use of ozone and oxygen nanobubbles has been studied for the remediation/decontamination of soil and aquatic ecosystems and for the oxidation of emerging pollutants in water and wastewater treatment. The future of nanobubbles in flotation separation research is highly promising; operating costs of the different forms of nanobubbles generation and bench studies should be validated through pilot and real scale with the continuous injection of these bubbles.

Pb low doses induced genotoxicity in Lactuca sativa plants

Soil and water contamination by lead (Pb) remains a topic of great concern, particularly regarding crop production. The admissible Pb values in irrigation water in several countries range from ≈0.1 to ≈5 mg L-1. In order to evaluate putative effects of Pb within legal doses on crops growth, we exposed Lactuca sativa seeds and seedlings to increasing doses of Pb(NO3)2 up to 20 mg L-1. The OECD parameter seed germination and seedling/plant growth were not affected by any of the Pb-concentrations used. However, for doses higher than 5 mg L-1 significant DNA damage was detected: Comet assay detected DNA fragmentation at ≥ 5 mg L-1 and presence of micronuclei (MN) were detected for 20 mg L-1. Also, cell cycle impairment was observed for doses as low as 0.05 mg L-1 and 0.5 mg L-1 (mostly G2 arrest). Our data show that for the low doses of Pb used, the OECD endpoints were not able to detect toxicity, while more sensitive endpoints (related with DNA damage and mitotic/interphase disorders) identified genotoxic and cytostatic effects. Furthermore, the nature of the genotoxic effect was dependent on the concentration. Finally, we recommend that MN test and the comet assay should be included as sensitive endpoints in (eco)toxicological assays.

Genotoxicity of citrate-coated silver nanoparticles to human keratinocytes assessed by the comet assay and cytokinesis blocked micronucleus assay

Silver nanoparticles (AgNPs) are widely used in industrial, cosmetic, and biomedical products, and humans are frequently exposed to these products through the skin. It is widely recognized that the characteristics of AgNPs (e.g., size, coating) may influence their cytotoxic effects, but their correlation with DNA damage and mitotic disorders remains poorly explored. In this study, human keratinocytes (HaCaT cell line) were exposed to well-characterized 30 nm AgNPs coated with citrate, and their effects on viability, DNA fragmentation (assessed by the comet assay), and micronuclei (MNi) induction (assessed by the cytokinesis-block micronucleus cytome assays, CBMN) were investigated. The results showed that 10 and 40 μg/mL AgNPs decreased cell proliferation and viability, and induced a significant genetic damage. This was observed by an increase of DNA amount in comet tail, which linearly correlated with dose and time of exposure. Also, cytostaticity (increase of mononucleated cells) and MNi rates increased in treated cells. In contrast, no significant changes were observed in nucleoplasmatic bridges (NPBs) or nuclear buds (NBUDs), although NBUDs tended to increase in all conditions and periods. The cytostatic effects on HaCaT cells were also shown by the decrease of their nuclear division index. Thus, both comet and CBMN assays supported the observation that citrate-AgNPs induced genotoxic effects on HaCaT cells. Considering that AgNPs are present in a vast number of consumer products and also in multiple nanomedicine skin applications and formulations, more research is needed to determine the properties that confer less toxicity of AgNPs to different cell lines.

A novel hybrid nanofibrous strategy to target progenitor cells for cost-effective in situ angiogenesis

Ti-doped calcium phosphate ormoglasses combined with biodegradable PLA promote an efficient and low-cost angiogenesis by the generation of high Ca²⁺concentrated interfaces that induce a high yield of tubulogenesis, with the gain in interface–cell interaction and instructivity.

Circulating cell-free DNA levels in Portuguese patients with psoriasis vulgaris according to severity and therapy

BACKGROUND

Inflammation has a key role in the pathogenesis of psoriasis. Circulating cell-free DNA (CFD) is a marker of tissue cell damage closely associated with inflammation.

OBJECTIVES

We aimed to understand the relation of CFD levels with psoriasis severity, defined by the Psoriasis Area and Severity Index (PASI), with inflammation and with psoriasis therapy.

METHODS

Forty-six patients with psoriasis vulgaris were evaluated before (T0) and after 12 weeks (T12) of treatment with narrowband ultraviolet light B (NB-UVB; n = 17), psoralen plus UVA (PUVA; n = 20) or topical therapy (n = 9). We evaluated interleukin (IL)-6 and circulating CFD levels.

RESULTS

Compared with controls, at T0, patients presented significantly higher levels of circulating CFD. CFD presented a significant positive correlation with IL-6 and a trend towards a positive correlation with PASI. Multiple linear regression analysis identified IL-6 as an independent variable associated with CFD circulating levels. As shown by the PASI score, a trend towards higher values of CFD was observed in the severe psoriasis forms; moderate and severe psoriasis presented also significantly higher CFD values, compared with control. Both NB-UVB and PUVA treatments significantly decreased the levels of CFD.

CONCLUSIONS

Patients with psoriasis, at the active stage of the disease, presented an increased inflammation associated with raised circulating CFD levels, which seem to be linked to psoriasis severity. Both NB-UVB and PUVA, anti-inflammatory therapies, were effective in decreasing CFD values. We propose that the evaluation of circulating CFD may provide a new biomarker to monitor psoriasis, its severity and its treatment.

The in vitro and in vivo genotoxicity of isotretinoin assessed by cytokinesis blocked micronucleus assay and comet assay

Isotretinoin is a retinoic acid frequently used in monotherapy or combined with narrow-band ultraviolet B (NBUVB) irradiation to treat patients with acne and psoriasis vulgaris. As both diseases need frequent and/or prolonged therapeutic interventions, the study of the genotoxicity of retinoids becomes important. Our aim was to study the genotoxic effects of isotretinoin alone or combined with NBUVB. In vitro studies were performed in the absence of S9 metabolic activation using blood from five healthy volunteers, incubated 72 h with isotretinoin (1.2-20 μM) (i.e., at concentrations usually achieved in blood with therapeutic doses as well as at higher concentrations). In vivo studies were also performed using blood from two patients with acne and three patients with psoriasis vulgaris treated with isotretinoin in monotherapy (8 or 20mg/day) or combined with NBUVB (20mg isotretinoin/day+NBUVB). The genotoxic effect was evaluated by the cytokinesis-blocked micronucleus and the comet assays. Our studies showed that isotretinoin alone was not genotoxic when tested in human lymphocytes in vitro and in vivo. There was no clear genotoxic effect in psoriatic patients treated with isotretinoin and NBUVB. The in vitro studies showed that isotretinoin induced apoptosis and necrosis in human lymphocytes at higher doses.

Circulating adipokine levels in Portuguese patients with psoriasis vulgaris according to body mass index, severity and therapy

BACKGROUND

Psoriasis vulgaris is associated with overweight/obesity and with increased C-reactive protein (CRP), tumour necrosis factor (TNF)-α, interleukin (IL)-6, leptin and resistin levels and decreased adiponectin levels.

OBJECTIVES

To understand the role/relationship of adipokines, as well as CRP, in a Portuguese psoriatic population, by assessing the relationship of their levels with psoriasis severity, defined by Psoriasis Area and Severity Index (PASI), with obesity, defined by body mass index (BMI), and psoriasis therapy.

METHODS

A cross-sectional (n=66) and longitudinal study (before and after 12 weeks of therapy; n=44) was performed; 10 patients started topical treatment, 17 narrow-band ultraviolet B (NBUVB) and 17 psolaren associated with UVA (PUVA).

RESULTS

Patients presented significantly higher BMI, leptin, resistin, TNF-α, IL-6 and CRP and significantly lower adiponectin values. CRP and IL-6 correlated with PASI. Adiponectin and leptin were more altered in patients with higher BMI. Concerning severity, CRP, resistin and adiponectin were more altered in the severer forms. After treatment, a significant reduction in PASI, CRP, resistin, TNF-α and IL-6, and a significant rise in adiponectin were observed. Nonetheless, CRP and adiponectin remained different from those of control. Concerning therapies, topical therapy was not associated with any significant change, except for TNF-α. After NBUVB, a significant reduction was observed in TNF-α and in CRP. For PUVA, we observed a significant reduction in TNF-α, IL-6 and CRP, and a significant increase in adiponectin.

CONCLUSION

In psoriatic patients, increased overweight/obesity was associated with raised leptin levels and decreased adiponectin levels. Leptin may contribute to enhance the inflammatory process in overweight/obese psoriatic patients. Resistin, IL-6, CRP and adiponectin levels appear to be dependent on psoriasis severity. CRP, together with IL-6, appears to be a useful marker of psoriasis severity. Both NBUVB and PUVA were effective; however, PUVA results seem to be more successful. Nonetheless, after NBUVB and PUVA, a low-grade inflammation still persists.

First Report of Bacterial Speck of Tomato Caused by Pseudomonas syringae pv. tomato Race 1 in Portugal

Protected and open field tomato crops are economically important for Portuguese agriculture. In 1983, Pseudomonas syringae pv. tomato (Okabe, 1933) Young, Dye & Wilkie, 1978 was first reported affecting protected crops (3) and then later under open field conditions (1). In the 2009 spring/summer season, several outbreaks of bacterial speck of tomato showing an unusual degree of severity were observed in open fields from the Tagus Valley Region. Typical symptoms included necrotic specks surrounded by a yellow halo on younger and older leaves with losses higher than 60% due to the heavy floral bud abortion. Abnormal lesions on the stems, as well as on the petioles and fruits, together with reduced growth of the entire plant, which is normally uncommon, were frequently observed in affected plants from distinct tomato cultivars (H-9665, H-9776, and CDX 255), two of them carrying the Pto resistance gene. Samples collected from different fields and cultivars were observed and used for isolation of the causal agent on King's medium B. The isolates were characterized (2) and Koch's postulates were fulfilled by carrying out pathogenicity tests. Ten plants from three commercial cultivars carrying the Pto resistance gene (CXD 255, Defender F1, and H-9775) were inoculated by spraying bacterial water suspensions (10⁸ CFU ml^-1) and kept under environmental conditions favorable for disease development. Positive and negative controls were also performed using P. syringae pv. tomato type strain (CFBP 2212T; race 0) and sterile distilled water, respectively. Cultural and biochemical characterization of the isolates showed their ability to produce levan, use sucrose, and induce a hypersensitivity reaction on tobacco leaves. Moreover, the isolates were oxidase negative, did not hydrolyze arginine nor produce soft rot on potato slices, and did not use erythritol as well as dl-lactate, identifying them as P. syringae pv. tomato. Typical and severe bacterial speck symptoms were produced in the Pto resistant tomato plants 4 days after inoculation and the isolates could be recovered after reisolation. Negative control plants showed no disease symptoms and CFBP 2212 was unable to produce typical lesions, except for a few in the older leaves. Altogether these results pointed to P. syringae pv. tomato race 1 as the disease causative agent. Further confirmation was achieved by partial sequencing of the rpoD gene using primers PsrpoD FNP1 and PsrpoDnprpcr1 (4). rpoD sequences, obtained from two isolates (CPBF 1288, GenBank HM368535; CPBF 1290, GenBank HM368537), were compared by nucleotide BLAST at NCBI displaying a 100% level of DNA similarity with strain Pto T1 belonging to P. syringae pv. tomato race 1. To our knowledge, this is the first report of the occurrence of Pseudomonas syringae pv. tomato race 1 in Portugal. References: (1) L. Cruz et al. ATTI Giornate Fitopatol, 2:399, 1992. (2) R. Lelliott and D. Stead. Methods for the Diagnosis of Bacterial Diseases of Plants. Blackwell Scientific Publications, Oxford, 1987. (3) H. Oliveira and J. Santa-Marta. Pseudomonas syringae pv. tomato (Okabe, 1933) Young, Dye & Wilkie, 1978. Uma nova bacteriose do tomateiro em Portugal. Publicação do Laboratório de Patologia Vegetal "Veríssimo de Almeida", 1983. (4). S. Sarkar et al. Genetics 174:1041, 2006.

Interleukin (IL)-22, IL-17, IL-23, IL-8, vascular endothelial growth factor and tumour necrosis factor-α levels in patients with psoriasis before, during and after psoralen-ultraviolet A and narrowband ultraviolet B therapy

BACKGROUND

Several cross-sectional studies have shown that different cytokines and growth factors are enhanced in psoriasis.

OBJECTIVES

We aimed to understand the role/relation of interleukin (IL)-22, IL-17, IL-23, IL-8, vascular endothelial growth factor (VEGF) and tumour necrosis factor (TNF)-α in psoriasis vulgaris, addressing their levels and changes before, during and after psoralen-ultraviolet A (PUVA) and narrowband ultraviolet B (NB-UVB) treatment.

METHODS

A cross-sectional and a longitudinal study (n = 34) - before (T0) and at 3 (T3), 6 (T6) and 12 (T12) weeks of NB-UVB and PUVA therapy - were performed; 17 patients started NB-UVB and 17 PUVA, and IL-22, IL-17, IL-23, IL-8, TNF-α and VEGF levels were evaluated.

RESULTS

At T0, compared with controls (n = 20), all the parameters were significantly higher in patients, except for TNF-α. Both NB-UVB and PUVA treatment gave, at T3, a significant decrease in TNF-α and IL-23; IL-22 and IL-17 decreased significantly at T6; all parameters and Psoriasis Area and Severity Index decreased significantly at T12. However, in both groups, at T12, VEGF was still significantly higher than control.

CONCLUSIONS

Psoriasis seems to be a complex disease in which the cytokine network is disturbed, namely in levels of IL-22, IL-17, IL-23, IL-8, TNF-α and VEGF. NB-UVB and PUVA follow-up studies suggested that the reduction in the IL-23/Th17 axis might be important in the pathogenic mechanisms of psoriasis. Further follow-up studies of patients with psoriasis treated with these and other therapies could be very helpful for the understanding of the disturbance in the cytokine network in psoriasis and indirectly in its pathogenesis.

Drug-resistant tuberculosis in six hospitals in Rio de Janeiro, Brazil

SETTING

Tuberculosis (TB) drug resistance survey in six hospitals in Rio de Janeiro, Brazil.

OBJECTIVE

To estimate resistance to at least one drug (DR) and multidrug resistance (MDR) and identify associated factors.

DESIGN

One-year cross-sectional survey. Hospitals were included as a convenience sample.

RESULTS

Of 595 patients investigated, 156 (26.2%) had previously undergone anti-tuberculosis treatment, 433 (72.8%) were not previously treated and information on the remaining 6 was not available. Overall, DR and MDR rates were high, at respectively 102 (17.1%, 95%CI 14.3-20.5) and 44 (7.4%, 95%CI 5.5-9.9) cases. Among individuals not previously treated, 17 had MDR (3.9%, 95%CI 2.4-6.3) and diagnosis in a TB reference hospital was independently associated with MDR (prevalence ratio [PR] 3.3, 95%CI 1.2-8.7) after multivariate analysis. Among previously treated individuals, 27 had MDR (17.3%, 95%CI 11.7-24.2). MDR-TB was independently associated with diagnosis in a TB reference hospital (PR 3.6, 95%CI 1.5-8.7), male sex (PR 2.3, 95%CI 1.2-4.4) and dyspnoea (PR 0.3, 95%CI 0.1-0.7).

CONCLUSION

We found high levels of DR- and MDR-TB. Our study design did not permit us to determine the contribution of community versus nosocomial transmission. Further studies are needed to establish this. Nevertheless, hospitals should be recognised as a potential source of transmission of resistant TB strains and urgent measures to avoid nosocomial TB transmission should be taken.

C-reactive protein and leucocyte activation in psoriasis vulgaris according to severity and therapy

BACKGROUND

Psoriasis vulgaris is a chronic recurrent inflammatory skin disease and psoriatic lesions have shown leucocyte infiltration.

OBJECTIVES

We aimed to study C-reactive protein (CRP) and leucocyte activation markers/inhibitors as potential monitors of psoriasis vulgaris.

METHODS

A cross-sectional (n = 73) and a longitudinal study (before, at 3, 6 and 12 weeks of therapy; n = 47) was performed; 10 patients started topical treatment, 17 narrow-band ultraviolet light B (NBUVB) and 20 psolaren associated to UVA (PUVA); psoriasis severity was defined by Psoriasis Area and Severity Index (PASI).

RESULTS

Compared with control (n = 38), we found higher CRP levels, total leukocyte/neutrophil count, elastase, lactoferrin and alpha1-antitrypsin. Increasing PASI was linked to increasing CRP and a trend to higher elastase and lactoferrin, suggesting that worsening enhances inflammatory response with neutrophil activation. CRP correlated with PASI, total leucocytes, neutrophils, elastase, lactoferrin and alpha1-antitrypsin. NBUVB and PUVA presented similar effects.

CONCLUSION

We propose CRP as a useful marker of psoriasis severity that could be used to monitor psoriasis and its treatment, and, together with PASI and elastase, could also be used as a global index of severity.

Improving chitosan-mediated gene transfer by the introduction of intracellular buffering moieties into the chitosan backbone

Chitosan was functionalized with imidazole moieties (CHimi) with the aim of improving its buffering capacity and promoting the endosomal escape ability of chitosan-DNA complexes, ultimately increasing their transfection efficiency. 5.6%, 12.9% and 22.1% of the glucosamine residues of chitosan were substituted. Complexes with different molar ratios of primary amines to DNA phosphate anion (N/P) were prepared by a coacervation method. For an N/P>3, CHimi polymers are able to complex electrostatically with DNA and condense it into positively charged nanostructures (average size 260 nm and zeta potential +16 mV at pH 5.5). In the concentration range 2.5-100 microg ml(-1), the modified polymers had no cytotoxic effect on 293T cells. CHimi polymers with the highest degree of substitution were found to enhance beta-gal expression in 293T and HepG2 cells. Bafilomycin A1 inhibited transfection, indicating that the protonation of the imidazole groups in the endolysosome pathway favors the escape of the complexes from the endosomes, increasing the amount of transgene that can reach the cell nucleus.

Soil and vegetation carbon stocks in Brazilian Western Amazonia: relationships and ecological implications for natural landscapes

The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east-west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting C stocks in Amazonia when such great pedological variability is not taken into account.