The Occurrence of Lung Cancer and Non-Pulmonary Malignancies After Pleural Infections.

BACKGROUND AND AIMS: Patients who develop infections of the pleura have several risk factors for malignancies, particularly lung cancer, and the infections might even be caused by undiagnosed intra-thoracic neoplasms. The aim of the study was to compare the occurrence of lung cancer and other malignancies between patients treated for pleural infections and controls during long-term follow-up. MATERIALS AND METHODS: All consecutive patients treated for pleural infections between January 2000 and June 2016 at the Tampere University Hospital were included. Ten matched controls and data regarding later cancer diagnoses were requested from national registries. The cancer types and rates, the diagnostic delays, as well as survival were compared between patients and controls. RESULTS: The material comprised 506 patients and 5022 controls (78% was male and median age was 60 years in both groups) with a median follow-up time of 69 months. In total, 74% of pleural infections were related to pneumonia. The occurrence of lung cancer during follow-up was 3.0% in all patients, 2.2% in pneumonia-related cases, and 0.6% in controls, p < 0.001 when compared with controls. The overall rate of non-pulmonary malignancies did not differ. Lung cancer was diagnosed within 3 months in 73% of patients versus in 6.9% of controls, p < 0.001. The survival in patients with later lung cancers or other malignancies was inferior to that of controls with similar neoplasms. CONCLUSION: The rate of lung cancer diagnoses was significantly increased in patients treated for pleural infections when compared with matched controls and the prognosis of patients with subsequent malignancies was impacted.

Trends in the Incidence, Etiology, Treatment, and Outcomes of Pleural Infections in Adults Over a Decade in a Finnish University Hospital.

BACKGROUND AND AIMS: The aim of the study was to ascertain changes in the incidence, etiology, treatment, and outcomes of pleural infections over a decade in a Finnish University Hospital. MATERIALS AND METHODS: All patients treated for pleural infections in Tampere University Hospital during 2000-2008 and 2012-2016 were included. The incidence rates and the epidemiologic data and medical history of patients, etiology of infection, and treatment trends and outcomes were compared between the cohorts. RESULTS: The incidence of pleural infections increased from 4.4 during 2000-2008 to 9.9 during 2012-2016 per 100.000 patient-years, p < 0.001. The patients in the latter group were older, 63 versus 57 years, p = 0.001, and the prevalence of chronic lung disease, hypertension, heart failure, dyslipidemia, and immunosuppressive medication were higher. The causes of infection remained similar and pneumonia accounted for 70% of all cases. The identification rate of the microbe pathogens increased from 49% to 64%, p = 0.002, while the distribution of identified pathogens was unchanged. More patients in the latter cohort were treated operatively, 88.3% versus 80.9%, p = 0.005, and, in these, the proportion of thoracoscopic surgery was higher, 57.4% versus 8.0%, p < 0.001, and the delay to surgery shorter, 5 versus 7 days, p < 0.001. Radiologic outcomes were similar. The 30-day mortality rate was 3.1% during 2000-2008 and 5.1% during 2012-2016, p = 0.293. CONCLUSION: The overall incidence of pleural infections has increased significantly while the causes of pleural infections and the distribution of pathogens remain unchanged. Contemporary patients are older with higher prevalence of comorbidities and more frequently undergo thoracoscopic surgery.

Long-Term Prognosis and Causes of Death After Pleural Infections.

BACKGROUND AND AIMS: The development of pleural infection may imply a worse state of health and prognosis. The objective of this study was to ascertain the long-term survival and causes of death after pleural infections and to compare them to those of matched controls. MATERIAL AND METHODS: Altogether 191 patients treated for pleural infections at a single University Hospital between January 2000 and December 2008 and 1910 age- and gender-matched controls were included. Survival data and the causes of death for non-survivors were obtained from national databases and compared between the groups. RESULTS: The etiology of pleural infection was pulmonary infection in 70%, procedural complication in 9%, trauma in 5%, malignancy in 4%, other in 7%, and unknown in 5% of patients. The course of treatment was surgical in 82%, drainage only in 12%, and conservative in 5% of included patients. The median follow-up time was 11 years. Mortality rates were 8.4% versus 0.8% during the first 90 days, p < 0.001, and 46.6% versus 24.5% overall, p < 0.001, in patients and controls, respectively. Mortality was significantly higher in patients with pulmonary infection, procedural complication, or malignancy as the etiology of pleural infection. In multivariable analysis, advanced age, previous malignancies, institutional care, alcoholism, and malignant etiology for the infection were associated with inferior survival. Deaths caused by malignancies, respiratory diseases, and digestive diseases were significantly more common in patients than in controls. CONCLUSION: Long-term survival in patients with pleural infections is significantly inferior to that of age and gender-matched controls.

Biogas from energy crops--optimal pre-treatments and storage, co-digestion and energy balance in boreal conditions.

The objective of this research was to evaluate the biogas production from crops in boreal conditions, focusing on the optimal pre-treatment and storage methods, co-digestion and energy balance of farm-scale crop based biogas plants. Alkaline treatments offered some potential for improving the methane yield from grass and sugar beet tops. The results show that the CH4 yield of energy crops can be maintained by appropriate ensiling conditions for even after 11 months in ambient conditions. The CH4 yield was best preserved with wet grass mixture without additives. Co-digestion of manure and crops was shown to be feasible with feedstock volatile solids (VS) containing up to 40% of crops. The highest specific methane yields of 268, 229 and 213 l CH4 kg(-1) VSadded in co-digestion of cow manure with grass, sugar beet tops and straw, respectively, were obtained during feeding with 30% of crop in the feedstock, corresponding to 85-105% of the total methane potential in the substrates as determined by batch assays. The energy output:input ratio of farm-scale grass silage based biogas plant varied significantly (3.5-8.2) with different assumptions and system boundaries being lowest when using only inorganic fertilizers and highest when half of the heat demand of the system could be covered by metabolic heat.

Co-digestion of grass silage and cow manure in a CSTR by re-circulation of alkali treated solids of the digestate.

Three laboratory, continuously stirred tank reactors (CSTRs) co-digesting grass silage and cow manure (forming 30% and 70% of substrate volatile solids (VS), respectively) were operated to evaluate the effects of re-circulating an alkali-treated and untreated solid fraction of the digestate back to the reactors. The CSTRs were operated at an organic loading rate (OLR) of 2 kg VS m(-3) day(-1) and hydraulic retention time (HRT) of 20 days with a semi-continuous mode of feeding. The feasibility of co-digestion with substrate VS containing 30% VS of crop was reinforced, resulting in average specific methane yield of about 180-185 1 CH4 kg(-1) VS. Re-circulation of the solid fraction of digestate back to the reactors in both alkali-treated and untreated forms decreased the methane yield by 11% and 21%, respectively, and resulted in operational problems such as scum formation and accumulation of the reactor materials. Batch studies were conducted to evaluate (i) the methane potentials of the solid fraction of digestate, and whole digestate with alkali treatments ranging from 20-60 g NaOH kg(-1) VS of substrate, and (ii) methane potentials of the accumulated reactor materials as top, middle and bottom layers. The solid fraction of digestate treated with 20 g NaOH kg(-1) VS showed higher specific methane yield (340 l CH4 kg(-1) VS) than the higher range of alkali treatments. The bottom layers of the control reactor and the reactor fed with alkali-treated solids gave a higher specific methane yield (93 and 85 l CH4 kg(-1) VS, respectively), and all three layers of untreated solids gave similar methane potentials.

Anaerobic digestion of grass silage in batch leach bed processes for methane production.

Anaerobic digestion of grass silage in batch leach bed reactors, with and without a second stage upflow anaerobic sludge blanket (UASB) reactor, was evaluated. Sixty six percent of the methane potential in grass was obtained within the 55 days solids retention time in the leach bed-UASB process without pH adjustment, whereas in the one-stage leach bed process 20% of the methane potential in grass was extracted. In two-stage operation, adjustment of the pH of influent to the leach bed reactor to 6 with HCl led to inhibition of both hydrolysis/acidogenesis and methanogenesis. In the leach bed-UASB process 39% of the carbohydrates and 58% of the acid soluble lignin were solubilised within the 49 days of operation, whereas Klason lignin was most recalcitrant. The methane potential of the digestates varied from 0.141 to 0.204 m3 CH4 kg(-1) added volatile solids.

Hydrolysis and microbial community analyses in two-stage anaerobic digestion of energy crops.

AIMS: The roles of the diverse populations of micro-organisms responsible for biodegradation of organic matter to form methane and carbon dioxide are rudimentarily understood. To expand the knowledge on links between microbial communities and the rate limiting, hydrolytic stage of two-stage biogas production from energy crops, this study was performed. METHODS AND RESULTS: The process performance and microbial communities (as determined by fluorescence in situ hybridization) in two separate two-stage batch digestions of sugar beets and grass/clover were studied. The microbial populations developed in the hydrolytic stage of anaerobic digestion of beets and grass/clover showed very few similarities, despite that the hydrolysis dynamics were similar. In both substrates, the solubilization of organic material was rapid for the first 10 days and accompanied by a build-up of volatile fatty acids (VFAs) and lactate. Between days 10 and 15, VFA and lactate concentrations decreased, as did the solubilization rates. For both substrates, Archaea started to appear in the hydrolytic stage between days 10 and 15, and the fraction of Bacteria decreased. The major bacterial group detected in the leachate fraction for beets was Alphaproteobacteria, whereas for grass/clover it was Firmicutes. The number of cells that bound to probes specifically targeting bacteria with cellulolytic activity was higher in the digestion of grass than in the digestion of beet. CONCLUSIONS: This study allowed the identification of the general bacterial groups involved, and the identification of a clear shift in the microbial population when hydrolysis rate became limiting for each of the substrates investigated. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings from this study could be considered as a first step towards the development of strategies to stimulate hydrolysis further and ultimately increasing the methane production rates and yields from reactor-based digestion of these substrates.

Two-stage anaerobic digestion of energy crops: methane production, nitrogen mineralisation and heavy metal mobilisation.

Energy crops (willow, sugar beet and grass silage) were digested in pilot scale two-stage anaerobic digesters. The specific methane yields obtained were 0.16, 0.38 and 0.39 m3 kg(-1) added volatile solids (VSadded) for willow, sugar beet and grass, respectively, corresponding to yearly gross energy yields of 15, 53 and 26 megawatt-hours (MWh) per hectare. With grass and sugar beets as substrate, 84-85% of the harvestable methane was obtained within 30 days. In pilot scale two-stage digestion of willow and sugar beet, 56 and 85% of the laboratory scale methane yields were obtained, but digestion of grass in two-stage reactors yielded 5% more methane than digestion in laboratory scale completely mixed low solids systems, possibly due to the pH conditions favourable to hydrolysis in the two-stage system. In digestion of grass and sugar beet the liquid at the end of digestion was rich in ammonium nitrogen, and the nitrogen in the substrate was efficiently mineralised. The results show that heavy metal concentrations are not likely to limit the utilisation of residues from digestion of nonmetal accumulating crops. Efficient mobilisation of heavy metals during the acidic phase of digestion revealed the possibility of removing metals from leachate generated in two-stage anaerobic digestion of phytoextracting crops.

Biomass characterization of laboratory-scale thermophilic-mesophilic wastewater treatment processes.

Two thermophilic-mesophilic wastewater treatment processes, one as the combination of the thermophilic activated sludge process (ASP), followed by the mesophilic ASP and the other as thermophilic suspended carrier biofilm process (SCBP), followed by the mesophilic ASP, were used to study sludge characteristics and floc formation. Thermophilic bacteria in both ASP and SCBP were able to form flocs, which were <50 microm in size and had a weak structure and irregular shape. Flocs in both the mesophilic ASPs were larger in size (50-500 microm) and had more compact structures. Filamentous bacteria played an important role in both the thermophilic and mesophilic processes by forming bridges between small flocs. Both thermophilic processes showed a high density of dispersed particles, such as free bacteria. When hydraulic retention time (HRT) was decreased the biofilm was retained in the thermophilic SCBP better than the flocs in the thermophilic ASP. The mesophilic ASPs efficiently removed dispersed particles originating from the thermophilic processes.

Comparative study of laboratory-scale thermophilic and mesophilic activated sludge processes.

Laboratory-scale mesophilic (20-35 degrees C) and thermophilic (55 degrees C) activated sludge processes (ASPs) treating diluted molasses wastewater were compared in effluent quality, removal of different COD fractions, sludge yield, floc size, and sludge settleability. The effect of polyaluminium chloride (PAC) with high cationic charge on sludge settleability and effluent quality was also studied. In the ASPs, the hydraulic retention time was 12h in both processes, corresponding to a volumetric loading rate of 3.2+/-1.0 kg COD(filt) m(-3)d(-1). The mesophilic ASP gave 79+/-18% and 90+/-2% and the thermophilic ASP gave 50+/-6% and 67+/-11% total COD (COD(tot)) and GF/A-filtered COD (COD(filt)) removals, respectively. The higher COD values in the thermophilic effluent were due to dispersed particles, such as free bacteria, measured as colloidal COD (COD(col)=difference between soluble COD (COD(sol)) and COD(filt)). Both ASPs gave high (90%) COD(sol) removals. Aeration (24-h) of the thermophilic ASP effluent at 35 degrees C reduced the density of the free bacteria by half, which was also measured as 90% COD(col) removal. Post-aeration of thermophilic effluent at 55 degrees C had no influence either on the density of free bacteria or on the COD(col) values. The use of PAC did not increase COD(tot) or COD(filt) removals in either process, but reduced the mesophilic and increased the thermophilic sludge volume index values.

Comparison of laboratory-scale thermophilic biofilm and activated sludge processes integrated with a mesophilic activated sludge process.

A combined thermophilic-mesophilic wastewater treatment was studied using a laboratory-scale thermophilic activated sludge process (ASP) followed by mesophilic ASP or a thermophilic suspended carrier biofilm process (SCBP) followed by mesophilic ASP, both systems treating diluted molasses (dilution factor 1:500 corresponding GF/A-filtered COD (COD(filt)) of 1900+/-190 mgl(-1)). With hydraulic retention times (HRTs) of 12-18 h the thermophilic ASP and thermophilic SCBP removed 60+/-13% and 62+/-7% of COD(filt), respectively, with HRT of 8 h the removals were 48+/-1% and 69+/-4%. The sludge volume index (SVI) was notably lower in the thermophilic SCBP (measured from suspended sludge) than in the thermophilic ASP. Under the lowest HRT the mesophilic ASP gave better performance (as SVI, COD(filt), and COD(tot) removals) after the thermophilic SCBP than after the thermophilic ASP. Measured sludge yields were low (less than 0.1 kg suspended solids (SS) kg COD(filt removed)(-1)) in all processes. Both thermophilic treatments removed 80-85% of soluble COD (COD(sol)) whereas suspended COD (COD(susp)) and colloidal COD (COD(col)) were increased. Both mesophilic post-treatments removed all COD(col) and most of the COD(susp) from the thermophilic effluents. In conclusion, combined thermophilic-mesophilic treatment appeared to be easily operable and produced high effluent quality.