Spread of Toxoplasma gondii among animals and humans in Northern Italy: A retrospective analysis in a One-Health framework.

Toxoplasmosis occurs worldwide and is considered one of the most important food-borne parasitic zoonoses. The consumption of undercooked meat containing viable tissue cysts and ingestion of environmental oocyst are the most important sources of infection. The aim of this retrospective study was to evaluate the spread of Toxoplasma gondii in the province of Bologna (Emilia-Romagna region) in northern Italy, with a One Health approach, comparing seropositivity rates in different animal species and in humans over the last 19 and 4 years respectively. Analyses were performed on serological data collected over different periods at three separate locations: Istituto Zooprofilattico Sperimentale della Lombardia e della Emilia-Romagna (IZSLER); Veterinary University Hospital Clinical Pathology Service, Department of Veterinary Medical Sciences, University of Bologna; and Unit of Microbiology, St. Orsola Hospital, Bologna. Most relevant seropositivity rates observed in animals were 15.5% (wild boar), 25% (roe deer), 18.7% (goat), 29.9% (sheep), 9.7% (pigs), 42.9% and 21.8% in cat and dog, respectively. A comprehensive screening was conducted on a population of 36,814 individuals, revealing a prevalence of 20.4%. Among pregnant women, a frequence of 0.39% for active toxoplasmosis was observed. Despite certain limitations, this study provided valuable insights into the extensive distribution of this parasitic infection among diverse animal species and human populations in the province of Bologna. These findings underscore the importance of implementing consistent and proactive toxoplasmosis screening protocols during pregnancy, while emphasizing the critical need for adopting a One Health approach for effective control of this parasitic disease.

Failure rate analysis and clinical outcomes of two different femoral tunnel positions using anteromedial portal technique in anterior cruciate ligament reconstruction.

AIM: To analyze two different femoral tunnel positions and to evaluate their correlation with clinical, functional outcomes and surgical revision rate in patients who underwent primary arthroscopic anterior cruciate ligament (ACL) reconstruction with anteromedial (AM) portal technique. METHODS: From January 2015 to October 2018, we recruited 244 patients that underwent primary single-bundle ACL reconstruction, using four strand-semitendinosus graft and AM portal technique for femoral tunnel placement. Patients were divided into two groups based on the different femoral tunnel positions: 117 patients of group A had ACL footprint center femoral tunnel position compared with 127 patients of group B, with femoral tunnel placement close to the AM bundle footprint. Preoperatively and at last follow up, all patients were assessed subjectively by Lysholm, Tegner, and International Knee Documentation Committee (IKDC) scores, while Lachman, Pivot-shift, and KT-1000 tests were performed to evaluate knee joint stability. RESULTS: Group B patients showed significantly better results in Lysholm, objective, and subjective IKDC scores compared with patients of group A (P < 0.001). A significantly higher surgical failure rate was found in group A than in group B (10.26% vs. 2.3%; P < 0.001). A higher anterior knee laxity was recorded in patients of group A than in patients of group B (1.9 ± 1.1 vs. 1.3 ± 1 mm; P < 0.001); a reduction in mean anterior tibial translation from preoperative to final follow up was found in group B compared with group A (3.5 ± 1.2 vs. 2.7 ± 1.1 mm; P < 0.001). No significant differences in the Tegner scale were found between the two groups. CONCLUSION: ACL reconstruction performed using the AM portal technique showed better and more satisfactory clinical and functional outcomes associated with a lower failure rate when the femoral tunnel had been placed more eccentrically in the footprint, in the AM bundle center position.

Study of energetic properties of different tree organs in six Olea europaea L. cultivars.

Pruning is an important horticultural practice for the management of olive orchards (Olea europaea L.) that generates a considerable amount of residues every year. Olive orchards are increasingly expanding beyond the Mediterranean Basin to new growing Countries (Australia, California, Argentina, Chile and Uruguay) and this will certainly lead to larger availability of pruning material. Currently, the interest in use of olive tree pruning residues for energy purposes is increasing but unfortunately, the information on the differences among organs of the tree, in terms of calorific value and ash content, is scarce. Another unknown aspect is the effect of cultivar vigour on dry matter partition among different tree organs, these are important traits to establish the energetic quality of pruning residues. The aim of this research was to study energetic aspects of six olive cultivars, largely grown in the Sicilian olive industry and characterized by different vigour. The trees taken into consideration in the study were selected in an experimental orchard to avoid any effect due to differences in environmental conditions and management. The energetic characteristics, calorific value and ash content, were evaluated for the various tree organs particularly shoots, leaves and branches; also root system was evaluated, although the roots can only be used once the trees are uprooted. Significant differences were observed in the calorific values among the different tree organs and the cultivars. Regarding the ash, shoots and leaves showed the highest content with respect to the other organs, thus causing a possible tendency in slagging with fouling and corrosion of boiler components.

Left atrial dilatation in systolic heart failure: a marker of poor prognosis, not just a buffer between the left ventricle and pulmonary circulation.

BACKGROUND: The relation between systolic pulmonary pressure (sPAP) and left atrium in patients with heart failure (HF) is unclear. Diastolic dysfunction, expressed as restrictive mitral filling pattern (RMP), and functional mitral regurgitation (FMR) are associated with both LA enlargement and increased sPAP. We aimed to evaluate whether atrial dilation might modulate the consequences of RMP and FMR on the pulmonary circulation of patients with HF with reduced ejection fraction (HFrEF). METHODS: 1256 HFrEF patients were retrospectively recruited in four Italian centers. Left ventricular (LVD) and atrial (LAD) diameters were measure by m-mode, and EF were measured. RMP was defined as E-wave deceleration time lower than 140 ms. FMR was quantitatively measured. sPAP was evaluated based on maximal tricuspid regurgitant velocity and estimated right atrial pressure. RESULTS: Final study population was formed by 1005 patients because of unavailability of sPAP in 252 patients. Mean EF was 33 ± 3, 35% had RMP, 67% had mild, and 26% moderate-to-severe FMR. 69% of patients had increased sPAP. A significant association was observed between sPAP and EF, RMP, FMR, and LAD (p < 0.0001 for all). At multivariate analysis, LAD was positively associated with sPAP (p < 0.0001) independently of EF, RMP, and FMR. Analogously, LAD (p < 0.05) was associated with more severe symptoms and worse prognosis after adjustment for LV function and FMR. CONCLUSION: LA dilation was positively associated with sPAP independently of EF, RMP, and FMR. This highlights that LA size should be considered a marker of the severity of the disease.

Persistent pulmonary congestion before discharge predicts rehospitalization in heart failure: a lung ultrasound study.

BACKGROUND: B-lines evaluated by lung ultrasound (LUS) are the sonographic sign of pulmonary congestion, a major predictor of morbidity and mortality in patients with heart failure (HF). Our aim was to assess the prognostic value of B-lines at discharge to predict rehospitalization at 6 months in patients with acute HF (AHF). METHODS: A prospective cohort of 100 patients admitted to a Cardiology Department for dyspnea and/or clinical suspicion of AHF were enrolled (mean age 70 ± 11 years). B-lines were evaluated at admission and before discharge. Subjects were followed-up for 6-months after discharge. RESULTS: Mean B-lines at admission was 48 ± 48 with a statistically significant reduction before discharge (20 ± 23, p < .0001). During follow-up, 14 patients were rehospitalized for decompensated HF. The 6-month event-free survival was highest in patients with less B-lines (≤ 15) and lowest in patients with more B-lines (> 15) (log rank χ(2) 20.5, p < .0001). On multivariable analysis, B-lines > 15 before discharge (hazard ratio [HR] 11.74; 95 % confidence interval [CI] 1.30-106.16) was an independent predictor of events at 6 months. CONCLUSIONS: Persistent pulmonary congestion before discharge evaluated by ultrasound strongly predicts rehospitalization for HF at 6-months. Absence or a mild degree of B-lines identify a subgroup at extremely low risk to be readmitted for HF decompensation.

Preterm infants with severe extrauterine growth retardation (EUGR) are at high risk of growth impairment during childhood.

UNLABELLED: Extrauterine growth retardation (EUGR) seriously affects premature newborns and is related to the impairment of growth during childhood. There are very limited data available concerning the growth outcome of EUGR children. Our aim was to assess the growth outcome in a cohort of children born before 34 weeks of gestation with severe EUGR. This was a retrospective multicenter study, performed in outpatient endocrinology clinic. A total of 103 premature children with weight and/or length below -2 standard deviation score (SDS) of "intrauterine" growth expectation at the time of discharge from hospital (within 42 weeks of postmenstrual age) were included in the study. The study participants underwent a thorough anthropometric assessment at a mean age of 3.9 years ± 1.7 SD. Of the EUGR children, 12.6 % showed a height below -2 SDS and 7.7 % even below -2.5 SDS. Growth impairment was more common in males than in females (17 vs. 8 %). The prevalence of subnormal weight (below -2 SDS) was 13.6 %, being higher in males than in females (17 vs. 10 %). BMI values below -2 SDS were found in 18.4 % of our study population (22.7 % in males and 12 % in females). The 19.6 % of EUGR children did not catch up in head circumference during early childhood. Length at term was the major predictor of height in childhood (P < 0.001). CONCLUSION: A significant proportion of children born prematurely with severe EUGR show growth retardation in childhood thus suggesting the need for a close clinical follow-up to determine their growth potential and implement effective intervention strategies.

Large-scale phylogenomic analysis reveals the phylogenetic position of the problematic taxon Protocruzia and unravels the deep phylogenetic affinities of the ciliate lineages.

The Ciliophora is one of the most studied protist lineages because of its important ecological role in the microbial loop. While there is an abundance of molecular data for many ciliate groups, it is commonly limited to the 18S ribosomal RNA locus. There is a paucity of data when it comes to availability of protein-coding genes especially for taxa that do not belong to the class Oligohymenophorea. To address this gap, we have sequenced EST libraries for 11 ciliate species. A supermatrix was constructed for phylogenomic analysis based on 158 genes and 42,158 characters and included 16 ciliates, four dinoflagellates and nine apicomplexans. This is the first multigene-based analysis focusing on the phylum Ciliophora. Our analyses reveal two robust superclades within the Intramacronucleata; one composed of the classes Spirotrichea, Armophorea and Litostomatea (SAL) and another with Colpodea and Oligohymenophorea. Furthermore, we provide corroborative evidence for removing the ambiguous taxon Protocruzia from the class Spirotrichea and placing it as incertae sedis in the phylum Ciliophora.

Effect of pelvic inclination and torsional deformity on canine acetabular morphology with computed tomography. A phantom study.

OBJECTIVES: To evaluate how the inclination and torsional deformity of the hemipelvis using extra-rotation as a model affect acetabular angle (AA) and dorsal acetabular rim angle (DARA) assessment with computed tomography (CT). METHODS: A normal canine hemipelvis positioned in dorsal recumbency was scanned with a 16-slice multidetector CT scanner, with different degrees of torsional deformity, using extra-rotation around the long axis (0-5-10-15°) of the hemipelvis. Each degree of extra-rotation was acquired at 0°, +20° and -20° of gantry tilt, to mimic different pelvic inclinations on its transverse axis. Cranial and central individual acetabular angles (IAA) and central DARA were calculated and correlated with inclination and torsional deformity. RESULTS: A very strong negative correlation was found between cranial and central IAA, pelvic inclination, and torsional deformity. A very strong positive correlation was found between DARA, pelvic inclination, and torsional deformity. CLINICAL SIGNIFICANCE: Pelvic inclination and torsional deformity affect acetabular angles assessment with CT. The greater the inclination (ilia far from the tabletop in dorsal recumbency) and torsional deformity of the pelvis, the worse the acetabulum appeared. A standardized scanning protocol for acetabular morphology assessment is needed and it should consider pelvic inclination. The actual relevance of pelvic torsional deformity is not well known and it should be investigated more thoroughly.

Effects on survival of loop diuretic dosing in ambulatory patients with chronic heart failure using a propensity score analysis.

OBJECTIVE: To ascertain whether increasing doses of orally administered furosemide are associated with impaired survival in outpatients with chronic heart failure (CHF) and left ventricular (LV) systolic dysfunction. METHODS: Transthoracic echo-Doppler examination was carried out at baseline in 813 consecutive CHF outpatients with LV ejection fraction ≤ 45%. The total daily dose of furosemide was assessed for each patient. Chronic kidney disease (CKD) was defined by a glomerular filtration rate < 60 ml/min/1.73 m(2). The end-point was all-cause mortality. To control the prognostic effect of furosemide for the propensity of using high doses of the drug, the Cox model was stratified by the propensity score, itself computed from a multivariable logistic model. Mean follow up was 44 months. RESULTS: After stratification for the propensity score, the risk of death increased linearly across quartiles of furosemide dose (HR 1.38, 95% CI 1.14-1.68, p < 0.001). A daily dose of 50 mg was identified as the best threshold value to predict a high risk of death within 3 years with an area under the ROC curve of 0.68 (95% CI 0.64-0.72). Increasing doses of furosemide were associated with an increased risk of death regardless of LV filling pattern, CKD and background therapy with ACE-inhibitors or beta-blockers. CONCLUSIONS: In outpatients with CHF, after stratification for the propensity score, the risk of death increased linearly across quartiles of furosemide daily dose. A threshold furosemide dose of 50 mg was related with the worse outcome.

Study on the reduction of atmospheric mercury emissions from mine waste enriched soils through native grass cover in the Mt. Amiata region of Italy.

Atmospheric mercury emissions from mine-waste enriched soils were measured in order to compare the mercury fluxes of bare soils with those from other soils covered by native grasses. Our research was conducted near Mt. Amiata in central Italy, an area that was one of the largest and most productive mining centers in Europe up into the 1980s. To determine in situ mercury emissions, we used a Plexiglas flux chamber connected to a portable mercury analyzer (Lumex RA-915+). This allowed us to detect, in real time, the mercury vapor in the air, and to correlate this with the meteorological parameters that we examined (solar radiation, soil temperature, and humidity). The highest mercury flux values (8000ngm(-2)h(-1)) were observed on bare soils during the hours of maximum insulation, while lower values (250ngm(-2)h(-1)) were observed on soils covered by native grasses. Our results indicate that two main environmental variables affect mercury emission: solar radiation intensity and soil temperature. The presence of native vegetation, which can shield soil surfaces from incident light, reduced mercury emissions, a result that we attribute to a drop in the efficiency of mercury photoreduction processes rather than to decreases in soil temperature. This finding is consistent with decreases in mercury flux values down to 3500ngm(-2)h(-1), which occurred under cloudy conditions despite high soil temperatures. Moreover, when the soil temperature was 28°C and the vegetation was removed from the experimental site, mercury emissions increased almost four-fold. This increase occurred almost immediately after the grasses were cut, and was approximately eight-fold after 20h. Thus, this study demonstrates that enhancing wild vegetation cover could be an inexpensive and effective approach in fostering a natural, self-renewing reduction of mercury emissions from mercury-contaminated soils.

Myositis ossificans circumscripta of the triceps muscle in a Rottweiler dog.

A 20-month-old male Rottweiler dog was presented with the complaint of chronic right forelimb lameness that was unresponsive to conservative treatment. Physical examination allowed for the topographical identification of the source of the problem as a firm enlargement of the soft tissues that was partially movable from humeral bone and compatible with an alteration of the triceps brachii muscle. Radiographic images showed signs that were highly suggestive of myositis ossificans. Computed tomography allowed for a more accurate characterization of the lesion, to exclude involvement of the elbow joint and humeral bone, and to localize anatomically the lesion in the caput accessorium and longum of the triceps brachii muscle. Surgical excision of the ossified portion of the triceps muscle was performed. Histological examination of the excised tissue substantiated the diagnosis of myositis ossificans. A one year clinical and radiographic follow-up examination showed a complete recovery, with no evidence of complications or recurrence. Despite myositis ossificans in dogs having previously been identified in the hindlimbs, this case of myositis ossificans circumscripta of the triceps muscle suggests that it may also occur in the muscles of the forelimb.

Molecular phylogeography of the asp viper Vipera aspis (Linnaeus, 1758) in Italy: evidence for introgressive hybridization and mitochondrial DNA capture.

Owing to its temperature dependence and low vagility, the asp viper (Vipera aspis) is an interesting model species to study the effects of Pleistocene climatic fluctuations on vertebrate genomes. We genotyped 102 specimens from the whole Italian distribution range at three mitochondrial DNA regions (2278 characters, total) and six microsatellite DNA loci (Short Tandem Repeats, STR). The molecular phylogeny was constructed according to Bayesian, Neighbour Joining, Maximum Parsimony and Maximum Likelihood procedures. All methods grouped individuals of the three morphological subspecies (V. a. aspis, V. a. francisciredi, V. a. hugyi) into five different haploclades. Specimens assigned to hugyi clustered in two highly differentiated clades, one being sister group to the complex comprising the second clade of hugyi (i.e., a paraphyletic status), plus two clades of francisciredi. The Bayesian clustering of the STR variability disclosed only two groups, the first including aspis and francisciredi, the second all hugyi. Introgressive hybridization and capture of francisciredi-like lineages in the hugyi mitochondrial genome were suggested to explain the discordance between mitochondrial and nuclear data. The phylogeographic pattern was compatible with population contractions in three glacial refuges. Plausibility of derived hypothesis was checked using coalescence simulations as post hoc tests. Long-term drift and serial founder effects, rather than selection, appeared the main factors affecting the genetic make-up of the Italian asp viper.

Dissolved gaseous mercury production in the dark: Evidence for the fundamental role of bacteria in different types of Mediterranean water bodies.

It is well established that the dissolved gaseous mercury (DGM) production in waters is mainly driven by photochemical processes. The present paper provides evidence for a significant bacteria-mediated DGM production, occurring also under dark conditions in environmentally different types of coastal water bodies of the Mediterranean basin. The DGM production was laboratory determined in sea, lagoon-brackish and lake water samples, comparing the efficiency of the DGM production processes in darkness and in the light. This latter condition was established by exposing samples at solar radiation intensity in the Photosyntetical Active Radiation region (PAR) of 200 W m(-2). Mercury reduction rate in the dark was of the order of 2-4% of the DGM production in lightness, depending on the total mercury concentration in the water, rather than the bacterial abundance in it. Support for the active bacterial role in mercury reduction rate under dark conditions was provided by: 1) absence of significant DGM production in sterilized water samples (following filtration treatment or autoclaving), 2) restored DGM production efficiency, following re-inoculation into the same water samples of representatives of their bacterial community, previously isolated and separately cultured. Notwithstanding the low bacteria-mediated vs. the high photo-induced DGM production, whatever natural water body was considered, it is worth stressing the significant contribution of this organismal-mediated process to oceanic mercury evasion, since it occurs continuously along the entire water column throughout the 24 h of the day.

Independence of restrictive filling pattern and LV ejection fraction with mortality in heart failure: an individual patient meta-analysis.

BACKGROUND: The Doppler echocardiographic restrictive mitral filling pattern (RFP) is an important prognostic indicator in patients with heart failure (HF), but the interaction between RFP, left ventricular ejection fraction (LVEF) and filling pattern remains uncertain. AIMS: To determine whether the RFP is predictive of mortality independently of LVEF in patients with HF. METHODS: Online databases were searched to identify studies assessing the relationship between prognosis and LV filling pattern in patients with HF. Individual patient data from 18 studies (3540 patients) were extracted and collated at the MeRGE Coordinating Centre (The University of Auckland). RESULTS: Overall, RFP was associated with higher all-cause mortality than the non-restrictive filling pattern: hazard ratio 2.42 (95% CI 2.06, 2.83). In multivariable analysis the RFP, LVEF, NYHA class and age were independent predictors of mortality. The prevalence of the RFP was inversely related to LVEF but remained a predictor of mortality even in those patients with preserved LVEF. CONCLUSIONS: The restrictive mitral filling pattern is a powerful predictor of mortality, independent of LVEF and age, in patients with HF. Doppler-derived LV filling patterns are an accessible marker from echocardiography that can readily be incorporated in risk stratification of all patients with HF.

Independent prognostic importance of a restrictive left ventricular filling pattern after myocardial infarction: an individual patient meta-analysis: Meta-Analysis Research Group in Echocardiography acute myocardial infarction.

BACKGROUND: Restrictive mitral filling pattern (RFP), the most severe form of diastolic dysfunction, is a predictor of outcome after acute myocardial infarction (AMI). Low power has precluded a definite conclusion on the independent importance of RFP, especially when overall systolic function is preserved. We undertook an individual patient meta-analysis to determine whether RFP is predictive of mortality independently of LV ejection fraction (LVEF), end-systolic volume index, and Killip class in patients after AMI. METHODS AND RESULTS: Twelve prospective studies (3396 patients) assessing the relationship between prognosis and Doppler echocardiographic LV filling pattern in patients after AMI were included. Individual patient data from each study were extracted and collated into a single database for analysis. RFP was associated with higher all-cause mortality (hazard ratio, 2.67; 95% CI, 2.23 to 3.20; P<0.001) and remained an independent predictor in multivariate analysis with age, gender, and LVEF. The overall prevalence of RFP was 20% but was highest (36%) in the quartile of patients with lowest LVEF (<39%) and lowest (9%) in patients with the highest LVEF (>53%; P<0.0001). RFP remained significant within each quartile of LVEF, and no interaction was found for RFP and LVEF (P=0.42). RFP also predicted mortality in patients with above- and below-median end-systolic volume index (1575 patients) and in different Killip classes (1746 patients). Importantly, when diabetes, current medication, and prior AMI were included in the model, RFP remained an independent predictor of outcome. CONCLUSIONS: Restrictive filling is an important independent predictor of mortality after AMI regardless of LVEF, end-systolic volume index, and Killip class.

[Emerging problems in enforcement of safe maternity and feeding protection at work: a public prevention service experience]. / Problematiche emerse nell'applicazione della tutela della lavoratrice in gravidanza, puerperio e allattamento: esperienza di un servizio pubblico di prevenzione.

We have examined the claims for advance maternity leave or prolonged benefits for breastfeeding addressed to Occupational Health Unity of Local Health Service 11 by women at harmful works in the period 2002-2005. The most frequent occupations were: shoemaker (29%), service company's employee (7%), tanners (7%), leather industry's employee (6%) and food industry's employee (6%). The most important risk factors were: bound postures, manual load handling, chemical hazards and biological agents. The numbers of claims increased during the period of interest. In the work place often risks for pregnancy and breastfeeding are not correctly assessed and women workers are not informed on their rights. The Occupational Health Unity of Local Health Service 11 tried to correct the lack of information for workers, employers, workers' representatives in health and safety and enterprise's occupational health physician.

[Silica risk in construction industry: an investigation on raw materials]. / Il rischio silice nel settore edilizia: esperienza di un'indagine sulle materie prime.

Typical construction activities like demolition, excavation and sanding can expose workers to silica, but there are few investigations carried out with the aim of evaluating the silica content in raw materials used for these activities (mortars, plasters, cement...). Our intervention has been directed in looking for free crystalline silica in samples of raw materials. We have measured the silica content in these materials comparing declared and real composition found in the products. Our intent was to obtain more information about the working activities which expose workers to free crystalline silica in construction industry and to highlight the silica presence in raw materials also when the companies don't declare it, against labeling rules based on Italian law D.lgs 65/03.

Cytotoxic effects and apoptotic signalling mechanisms of the sesquiterpenoid euplotin C, a secondary metabolite of the marine ciliate Euplotes crassus, in tumour cells.

Most antitumour agents with cytotoxic properties induce apoptosis. The lipophilic compound euplotin C, isolated from the ciliate Euplotes crassus, is toxic to a number of different opportunistic or pathogenic microorganisms, although its mechanism of action is currently unknown. We report here that euplotin C is a powerful cytotoxic and pro-apoptotic agent in mouse AtT-20 and rat PC12 tumour-derived cell lines. In addition, we provide evidence that euplotin C treatment results in rapid activation of ryanodine receptors, depletion of Ca2+ stores in the endoplasmic reticulum (ER), the release of cytochrome c from the mitochondria, activation of caspase-12, and activation of caspase-3, leading to apoptosis. Intracellular Ca2+ overload is an early event which induces apoptosis and is parallelled by ER stress and the release of cytochrome c, whereas caspase-12 may be activated by euplotin C at a later stage in the apoptosis pathway. These events, either independently or concomitantly, lead to the activation of the caspase-3 and its downstream effectors, triggering the cell to undergo apoptosis. These results demonstrate that euplotin C may be considered for the design of cytotoxic and pro-apoptotic new drugs.

Importance of the biogenic organic matter in photo-formation of dissolved gaseous mercury in a culture of the marine diatom Chaetoceros sp.

Laboratory experiments on DGM production under light/dark cycles in a culture of the marine diatom Chaetoceros sp. spiked with 200 ng l(-1) of mercury have been performed. DGM formation has been investigated also in the cell exudates, obtained by filtration of the cell culture. Results show that the cell culture and the filtrate give the same value of DGM production (2.24+/-0.88 pg min(-1) l(-1) and 2.23+/-0.02 pg min(-1) l(-1), respectively) in the light (40 W m(-2)), values much higher than to those obtained in the medium culture alone. A significant DGM production has been measured in dark conditions both in the cell culture (0.48+/-0.11 pg min(-1) l(-1)) and in the filtrate (0.85+/-0.10 pg min(-1) l(-1)). The results highlight that the organic compounds released by the cell in the culture medium play a fundamental role in the DGM photo-formation processes.