153 research outputs found
New multifunctional degrading microorganisms and optimization of renewable source conversion in biofuels of second and third generation
In recent years, climate change and energy issues have become prominent in public life. Governments have initiated extensive research into the large-scale production of alternative liquid transportation fuels from renewable resources to reduce the reliance on fossil fuels. Generally, biofuels used in the transportation sector are currently represented mainly by bioethanol and biodiesel. Second and third generation fuels are produce by non-edible crops, as Arundo donax, Populus nigra and Eucalyptus camaldulensis, and residues from industry, as sewage sludge.
Biological catalysts (bacteria and yeasts) play significant roles in the conversion lignocellulosic biomass in bioethanol: degrade the cellulose, hemicellulose, lignin and pectin and ferment the monosaccharides. The pretreated biomass can be processed using a variety of process configurations: Prehydrolysis and simultaneous saccharification and fermentation (PSSF), simultaneous saccharification and fermentation (SSF), simultaneous saccharification and co-fermentation (SSCF). Advantages from bioethanol production: produced from a variety of raw materials; it is non-toxic; easily introduced into the existing infrastructure. Two principal techniques used for biodiesel production are acid esterification followed by basic transesterification and enzymatic esterification followed by basic transesterification. Moreover, the extraction and transformation of the lipids from organic wastewater sludge represent a cheap and readily available feedstock for biodiesel production.
This research project was focused on the selection of new microorganisms able to hydrolyse and ferment renewable resource as lignocellulose biomass and on the evaluation and optimization of parameters in different configuration process for bioethanol and biodiesel production.
The microbial isolation was performed from chipped vegetable biomass piles of Arundo donax, Eucalyptus camaldulensis and Populus nigra processed to degradation under natural conditions. Cellulolytic, pectinolytic, hemicellulolytic, ligninolytic and yeasts microorganisms were isolated by differential selective solid substrates. Qualitative and semi-quantitative assessments were performed to determinate endo- and exo- cellulase, ß-glucosidase, xylanase, pectinase, ligninase, peroxidase and laccase enzymatic activities. Moreover, xylose and glucose fermentation tests were performed. Furthermore, PSSF, SSF and SSCF experiments were carried out to evaluate and selected the optimal enzyme concentration, solid amount and process configuration for bioethanol production. In addition, different acid and enzymatic esterification, and basic transesterification were performed to biodiesel production using sewage sludge.
540 endo-cellulolytic, 678 exo-cellulolytic, 709 hemicellulolytic, 385 pectinolytic and 248 ligninolytic microorganisms were isolated (total 1291 isolates) of which 753 showed multi-enzymatic activities. Some isolates were able to convert all the principal components of vegetable biomasses such as cellulose, hemicelluloses, lignin and pectin. Moreover, Saccharomyces cerevisiae NA227, Pichia caribbica NS117 and Cyberlindnera maclurae E41L were selected to ability glucose and xylose ferment, respectively.
The complex experiments of saccharification and fermentation carried out, allowed to define the best conditions for the second generation bioethanol production: 15% of pretreated A. donax biomass, 69.63 FPU g-1 of cellulose, temperature of 37°C, inocula separated of S. cerevisiae NA227 and P. caribbica NS117 (about 108 CFU mL-1 for each strain) and simultaneous saccharification and co-fermentation process (SSCF) as process configuration. The best performances, in biodiesel production from sewage sludge, were obtained using sulfuric acid and sodium hydroxide as catalysts.
In conclusion: many procariotyc and eucariotic strains were characterised, identified and selected for their multi-enzymatic activities. They represent a precious biological and genetic source to upgrade the feasibility of lignocellulose conversion for the 'greener' technology of second-generation biofuel. The optimization of the bioethanol production required to find the best performances that were enhanced by modifying the biotechnological parameters of the fermentation process such as the temperature, the enzymes concentration, the amount of pretreated vegetable biomass, the configuration process as well as the selection of Saccharomyces and non-Saccharomyces yeast strains. Moreover, preliminary results in biodiesel production could give an important indication about the performances obtained using different catalysts
Chronic infection with non-tuberculous mycobacteria in patients with non-CF bronchiectasis: Comparison with other pathogens
Abstract Introduction The aim of this study is to compare characteristics of non-cystic fibrosis bronchiectasis (NCFBE) patients with chronic infections with non-tuberculous mycobacteria (NTM) versus those with Pseudomonas aeruginosa or other colonizations. Methods This was an observational, perspective study of consecutive NCFBE adult patients attending the outpatient bronchiectasis clinic at the San Gerardo Hospital in Monza, Italy, during 2012 and 2013. Patients with a chronic infection were included in the study and divided into three groups: those with NTM (Group A); those with P. aeruginosa (Group B); and those with other pathogens (Group C). Patients with both NTM and another pathogen were included in Group A. Comparison among the three study groups was performed using X 2 or Fisher exact test for categorical variables or Kruskal–Wallis or Mann–Whitney test for continuous variables. Results A total of 146 patients (median age 67 years, 40% males) were enrolled: 19 belonged to Group A, 34 to Group B and 93 to Group C. Within group A, 6 patients had only NTM isolation, 7 patients had NTM and P. aeruginosa co-infection and 6 patients had NTM plus another pathogen. The most common isolated pathogens among NTM was Mycobacterium avium complex (15 patients, 79%). A total of 4 patients (21%) with NTM were on active treatment. Patients affected by NTM pulmonary infection had a significantly less severe clinical, functional and radiological involvement compared with patients colonized by P. aeruginosa , see Table. Group A (NTM) n = 19 Group B ( P. aeruginosa ) n = 34 Group C (Others) n = 93 p Value ∗ p Value # p Value + Age (years), median (IQR) 70 (64–75) 74 (67–79) 66 (53–72) 0.001 0.172 0.050 Male, n (%) 8 (42) 15 (44) 36 (33) 0.660 – – BMI, median (IQR) 22 (19–26) 24 (21–25) 24 (21–27) 0.352 – – BSI, median (IQR) 5 (4–9) 12 (8.5–16) 5 (3–7) 0.001 0.001 0.090 Bhalla score, median (IQR) 21 (15–34) 36 (30.5–40.5) 16 (10.5–21.5) 0.001 0.016 0.076 Idiopathic etiology, n (%) 8 (42) 11 (32) 37 (40) 0.721 – – Post-infective etiology, n (%) 8 (42) 16 (47) 29 (31) 0.244 – – Exacerbations/y, median (IQR) 1 (0–2) 2 (1.5–3.5) 2 (1–2) 0.040 0.024 0.132 FEV1%, median (IQR) 85 (59.75–109.5) 58.5 (48.25–74) 84 (62–102) 0.002 0.010 0.857 FVC%, median (IQR) 94.5 (70–109.75) 65 (56–81.5) 88 (69.5–101.5) 0.003 0.003 0.270 ∗ Among the three groups: # Group A vs. Group B; + Group A vs. Group C; BMI: Body mass index; BSI: bronchiectasis severity index; y: year. Conclusions Colonization with P. aeruginosa seems to have the highest impact on the clinical, functional and radiological status of patients with NCFBE. No specific characteristics may help to identify NTM versus other pathogen colonizations. Thus, diagnostics for atypical mycobacteria should be performed on all patients with NCFBE, as suggested by recent international guidelines
Positive end expiratory pressure in acute hypoxemic respiratory failure due to community acquired pneumonia: Do we need a personalized approach?
Background. Acute respiratory failure (ARF) is a life-threatening complication in patients with community acquired pneumonia (CAP). The use of non-invasive ventilation is controversial. With this prospective, observational study we aimed to describe a protocol to assess whether a patient with moderate-to-severe hypoxemic ARF secondary to CAP benefits, in clinical and laboratoristic terms, from the application of a positive end expiratory pressure (PEEP) + oxygen vs oxygen alone. Methods. Patients who benefit from PEEP application (PEEP-responders) were defined as those with partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2) increase > 20% and/or reduction of respiratory distress during PEEP + oxygen therapy compared to oxygen therapy alone. Clinical characteristics and outcomes were compared between PEEP-responders and PEEP-non responders. Results. Out of 41 patients, 27 (66%) benefit from PEEP application (PEEPresponders), the best response was obtained with a PEEP of 10 cmH2O in 13 patients, 7.5 cmH2O in eight and 5 cmH2O in six. PEEP-responders were less likely to present comorbidities compared to PEEP-non responders. No differences between groups were found in regards to endotracheal intubation criteria fullfillment, intensive care unit admission and in-hospital mortality, while PEEP-responders had a shorter length of hospital stay. Discussion. The application of a protocol to evaluate PEEP responsiveness might be useful in patients with moderate-to-severe hypoxemic ARF due to CAP in order to personalize and maximize the effectiveness of therapy, and prevent the inappropriate PEEP use. PEEP responsiveness does not seem to be associated with better outcomes, with the exception of a shorter length of hospital stay
Clinical phenotypes in adult patients with bronchiectasis
Bronchiectasis is a heterogeneous disease. This study aimed at identifying discrete groups of patients with different clinical and biological characteristics and long-term outcomes. This was a secondary analysis of five European databases of prospectively enrolled adult outpatients with bronchiectasis. Principal component and cluster analyses were performed using demographics, comorbidities, and clinical, radiological, functional and microbiological variables collected during the stable state. Exacerbations, hospitalisations and mortality during a 3-year follow-up were recorded. Clusters were externally validated in an independent cohort of patients with bronchiectasis, also investigating inflammatory markers in sputum. Among 1145 patients (median age 66 years; 40% male), four clusters were identified driven by the presence of chronic infection with Pseudomonas aeruginosa or other pathogens and daily sputum: "Pseudomonas" (16%), "Other chronic infection" (24%), "Daily sputum" (33%) and "Dry bronchiectasis" (27%). Patients in the four clusters showed significant differences in terms of quality of life, exacerbations, hospitalisations and mortality during follow-up. In the validation cohort, free neutrophil elastase activity, myeloperoxidase activity and interleukin-1\u3b2 levels in sputum were significantly different among the clusters. Identification of four clinical phenotypes in bronchiectasis could favour focused treatments in future interventional studies designed to alter the natural history of the disease
Characterizing non-tuberculous mycobacteria infection in bronchiectasis
Chronic airway infection is a key aspect of the pathogenesis of bronchiectasis. A growing interest has been raised on non-tuberculous mycobacteria (NTM) infection. We aimed at describing the clinical characteristics, diagnostic process, therapeutic options and outcomes of bronchiectasis patients with pulmonary NTM (pNTM) disease. This was a prospective, observational study enrolling 261 adult bronchiectasis patients during the stable state at the San Gerardo Hospital, Monza, Italy, from 2012 to 2015. Three groups were identified: pNTM disease; chronic P. aeruginosa infection; chronic infection due to bacteria other than P. aeruginosa. NTM were isolated in 32 (12%) patients, and among them, a diagnosis of pNTM disease was reached in 23 cases. When compared to chronic P. aeruginosa infection, patients with pNTM were more likely to have cylindrical bronchiectasis and a “tree-in-bud” pattern, a history of weight loss, a lower disease severity and a lower number of pulmonary exacerbations. Among pNTM patients who started treatment, 68% showed a radiological improvement, and 37% achieved culture conversion without recurrence, while 21% showed NTM isolation recurrence. NTM isolation seems to be a frequent event in bronchiectasis patients, and few parameters might help to suspect NTM infection. Treatment indications and monitoring still remain an important area for future research
Arrhythmogenic Right Ventricular Cardiomyopathy: Characterization of Left Ventricular Phenotype and Differential Diagnosis With Dilated Cardiomyopathy
Background This study assessed the prevalence of left ventricular (LV) involvement and characterized the clinical, electrocardiographic, and imaging features of LV phenotype in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Differential diagnosis between ARVC-LV phenotype and dilated cardiomyopathy (DCM) was evaluated. Methods and Results The study population included 87 ARVC patients (median age 34\ua0years) and 153 DCM patients (median age 51\ua0years). All underwent cardiac magnetic resonance with quantitative tissue characterization. Fifty-eight ARVC patients (67%) had LV involvement, with both LV systolic dysfunction and LV late gadolinium enhancement (LGE) in 41/58 (71%) and LV-LGE in isolation in 17 (29%). Compared with DCM, the ARVC-LV phenotype was statistically significantly more often characterized by low QRS voltages in limb leads, T-wave inversion in the inferolateral leads and major ventricular arrhythmias. LV-LGE was found in all ARVC patients with LV systolic dysfunction and in 69/153 (45%) of DCM patients. Patients with ARVC and LV systolic dysfunction had a greater amount of LV-LGE (25% versus 13% of LV mass; P<0.01), mostly localized in the subepicardial LV wall layers. An LV-LGE 6520% had a 100% specificity for diagnosis of ARVC-LV phenotype. An inverse correlation between LV ejection fraction and LV-LGE extent was found in the ARVC-LV phenotype (r=-0.63; P<0.01), but not in DCM (r=-0.01; P=0.94). Conclusions LV involvement in ARVC is common and characterized by clinical and cardiac magnetic resonance features which differ from those seen in DCM. The most distinctive feature of ARVC-LV phenotype is the large amount of LV-LGE/fibrosis, which impacts directly and negatively on the LV systolic function
Rationale and protocol of a double-blind, randomized, placebo-controlled trial to test the efficacy, safety, and tolerability of dimethyl fumarate in Friedreich Ataxia (DMF-FA-201)
IntroductionFriedreich Ataxia (FRDA) is an autosomal recessive neurodegenerative disorder that causes gait and limb ataxia, dysarthria, and impaired vibratory sense, with cardiomyopathy being the predominant cause of death. There is no approved therapy, which results in the use of symptomatic treatments and the chronic support of physiotherapy. Dimethyl fumarate (DMF) is a fumaric acid ester used for the treatment of psoriasis and Multiple Sclerosis (MS). It induces Nrf2 in vitro and in vivo, and it increases frataxin in FRDA patient lymphoblasts, in mouse models, and in MS treated patients.MethodsThe aim of our study is to investigate if DMF can increase the expression of the FXN gene and frataxin protein and ameliorate in-vivo detectable measures of mitochondrial dysfunction in FRDA. The study is composed of a screening visit and two sequential 12-week phases: a core phase and an extension phase. During the first phase (core), patients will be randomly assigned to either the DMF or a placebo group in a 1:1 ratio. During the first week, patients will receive a total daily dose of 240 mg of DMF or placebo; from the second week of treatment, the dose will be increased to two 120 mg tablets BID for a total daily dose of 480 mg. During the second phase (extension), all patients will be treated with DMF. EudraCT number 2021-006274-23.EndpointsThe primary endpoint will be a change in FXN gene expression level after 12 weeks of treatment. Secondary endpoints will be frataxin protein level, cardiopulmonary exercise test outputs, echocardiographic measures, Nrf2 pathway and mitochondrial biogenesis gene expression, safety, clinical scales, and quality of life scales.ConclusionsThis is the first study aimed at exploring the ability of DMF, an already available treatment for MS and psoriasis, to correct the biological deficits of FRDA and potentially improve mitochondrial respiration in-vivo
Continuous versus intermittent antibiotics for bronchiectasis
Background Bronchiectasis is a chronic airway disease characterised by a destructive cycle of recurrent airway infection, inflammation and tissue damage. Antibiotics are a main treatment for bronchiectasis. The aim of continuous therapy with prophylactic antibiotics is to suppress bacterial load, but bacteria may become resistant to the antibiotic, leading to a loss of effectiveness. On the other hand, intermittent prophylactic antibiotics, given over a predefined duration and interval, may reduce antibiotic selection pressure and reduce or prevent the development of resistance. This systematic review aimed to evaluate the current evidence for studies comparing continuous versus intermittent administration of antibiotic treatment in bronchiectasis in terms of clinical efficacy, the emergence of resistance and serious adverse events. Objectives To evaluate the effectiveness of continuous versus intermittent antibiotics in the treatment of adults and children with bronchiectasis, using the primary outcomes of exacerbations, antibiotic resistance and serious adverse events. Search methods On 1 August 2017 and 4 May 2018 we searched the Cochrane Airways Review Group Specialised Register (CAGR), CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and AMED. On 25 September 2017 and 4 May 2018 we also searched www.clinicaltrials.gov, the World Health Organization (WHO) trials portal, conference proceedings and the reference lists of existing systematic reviews. Selection criteria We planned to include randomised controlled trials (RCTs) of adults or children with bronchiectasis that compared continuous versus intermittent administration of long-term prophylactic antibiotics of at least three months' duration. We considered eligible studies reported as full-text articles, as abstracts only and unpublished data. Data collection and analysis Two review authors independently screened the search results and full-text reports. Main results We identified 268 unique records. Of these we retrieved and examined 126 full-text reports, representing 114 studies, but none of these studies met our inclusion criteria. Authors' conclusions No randomised controlled trials have compared the effectiveness and risks of continuous antibiotic therapy versus intermittent antibiotic therapy for bronchiectasis. High-quality clinical trials are needed to establish which of these interventions is more effective for reducing the frequency and duration of exacerbations, antibiotic resistance and the occurrence of serious adverse events. Plain language summary Are antibiotics more effective when given continuously or intermittently to people with bronchiectasis? Background Bronchiectasis is an incurable lung disease characterised by repeated chest infections. Antibiotics are a main form of treatment and can be taken long term to prevent chest infections from developing. This could be continuously or intermittently for a fixed period of time. However, we do not currently know which approach is the most effective for reducing the frequency and duration of exacerbations, managing antibiotic resistance and minimising side effects. Study Characteristics On 1 August 2017 we searched a wide range of sources to find clinical trials for our review. We found 268 potentially relevant results but on closer examination none of the studies met our review criteria and none could be included. Authors' conclusions There is no high-quality evidence about whether continuously administered or intermittently administered antibiotics are safer and more helpful for people with bronchiectasis. More research is needed to evaluate which one of these methods is better for reducing chest infections, limiting resistance to antibiotic therapy and reducing serious side effects
- …