Anthropogenic impacts on the Orbetello lagoon ecosystem

The aim of the present study was to assess the environmental quality of Orbetello lagoon (Tyrrhenian coast, Italy), using a biomonitoring method based on measuring organochlorinated pollutants in the Anguilla anguilla, chosen as sentinel organism, and remote sensing data obtained by elaboration of Landsat 7 Enhanced Thematic Mapper (ETM) data of 2002. Polychlorinated biphenyls and organochlorine pesticides were determined by gas chromatography/mass spectrometry in muscle of European eels captured in seven sites having different levels of pollution in Orbetello lagoon. Remote sensing data and chemical analysis showed the Albegna river as a probable vehicle of pesticides (hexachlorocyclohexanes).

Assessment of environmental pollutants in ten southern Italy harbor sediments

In 2003–2006, the distribution of macronutrients and pollutants of environmental interest was investigated in surficial sediments collected from 10 southern Italy harbors selected in four different regions. About 167 stations were sampled to determine levels of total organic carbon, total nitrogen, total phosphorous, trace elements (Al, Cd, Pb, Ni, Cr, Cu, Zn, Hg, As), short- and long-chain aliphatic hydrocarbons ( Hy C > 12 and Hy C < 12), and concentrations of persistent organic pollutants (polychlorinated biphenyls, polycyclic aromatic hydrocarbons [PAHs], p-p-Dichlorodiphenyldichloroethylene ( 4,4′-DDE), and Hexachlorobenzene (HCB). General relationships between studied variables and harbors systems were explored by multivariate statistical approaches. Results show that wide fluctuations are reported for all variables both among harbors and inside each studied system. Principal components analysis suggests that major significance in explaining total average variability is due to lead, copper, zinc, silts, sands, and PAHs. No significance has been observed when testing nonmetric multidimensional scaling distributions relating with the factor “region,” while performing analyses on factor “main human activity,” a higher significance is observed. These results suggest a strong relationship between the main human use of marine systems and observed pollution levels in sediments.

PCB levels in European eel (Anguilla anguilla) from two coastal lagoons of the Mediterranean

Eels are exposed to pollutants due to their unusual life cycle and are vulnerable to contamination associated with sediment due to their diet, feeding habits and territoriality. Since the 1980s, a decline in American and European eel populations has been recorded. The causes of this decline still are unknown but pollution from domestic and industrial effluents is known to be involved. Since little data is available on PCB contamination in eels from Italian waters, PCBs were measured in muscle of Anguilla anguilla captured in 2001 in two brackish ecosystems of the Mediterranean: the lagoons of Orbetello and Santa Giusta (Italy). PCBs were higher in samples from Orbetello lagoon than in those detected from Santa Giusta lagoon (P < 0.05). Congener and isomer analyses indicated Aroclor 1260 as a likely source of PCBs in the Orbetello and Santa Giusta samples. Only the toxic equivalents (TEQs) of mono-ortho PCBs were calculated.

Cytochrome P450, acetylcholinesterase and gonadal histology for evaluating contaminant exposure levels in fishes from a highly eutrophic brackish ecosystem: the Orbetello Lagoon, Italy

Biochemical markers and ovarian histology were investigated in prespawning females of grass goby (Zosterisessor ophiocephalus) and grey mullet (Mugil cephalus) collected, respectively, in late spring and summer 2000 in four sites of a highly eutrophic brackish ecosystem of central Italy, the Orbetello Lagoon. Exposure to chlorinated and aromatic hydrocarbons was evaluated in fish livers by the somatic liver index (SLI) and by measuring 7-ethoxyresorufin-O-deethylase (EROD) and benzo(a)pyrene monooxygenase (BaPMO) activities. Acetylcholinesterase (AChE) activity was measured in brain and gills to evaluate exposure to organophosphates (OPs) and carbamates (CBs). The gonad somatic index (GSI) was used to confirm ovarian maturation and ovarian histology was investigated as a potential biomarker for environmental effects. Samples from the Western Basin, near a sewage treatment plant (STP) off the town of Orbetello, showed higher SLI values and higher EROD and BaPMO activities than those collected from the Ansedonia Canal (AC) in the Eastern Basin (p<0.05) and respect to those from reference sites: the Albegna River (AR) Delta for grass goby and the Nassa Canal (NC), connected with the sea, for grey mullet both located in the Western Basin as well. Low brain AChE activity was observed in both species from the reference sites (AR and NC) in association with the presence of anomalies in developing oocytes: unexpectedly small in grass goby and irregular disintegrated cytoplasm in grey mullet. The results indicate that the Western Basin is more polluted than the Eastern Basin particularly in the Orbetello where the sewage treatment plant may be a source of aromatic and chlorinated compounds while the Albegna River and the Nassa Canal may be sources of OPs and CBs.

[Guidelines on intestinal dysmicrobism (SIBO Small Intestine Bacterial Overgrowth)]

Bacterial flora consisting of Gram-positive and Gram-negative germs, aerobes and anaerobes, is distributed along the digestive tract in varying quantities from zero to a maximum of 10(12)/ml of endoluminal aspirate. This bacterial ecosystem counterbalances with the ecological niche of the host organism and harmonizes with the various digestive, secretory, motor, absorption and sensitivity functions of the entire intestine. This dynamic equilibrium between environment, bacterial flora and host may be interrupted due to a variety of complex reasons, leading to quantitative and qualitative modifications of the normal intestinal microbial flora that can cause Small Intestinal Bacterial Overgrowth (SIBO). SIBO is thus due to an invasion of the small intestine, from the upper part, by pathogenic strains of oro-alimentary origin, and from the lower part by colo-fecal germs through an incontinent Bauhin's valve. These germs alter the normal intestinal functions and give rise to a form of diarrhoea in which the characteristics of malabsorption prevail, with all the inherent diagnostic problems. The diagnostic gold standard is the culture of the duodenal-jejunal aspirate which, being difficult to perform and providing unreliable results, is not easily included in the daily clinical routine. Indirect tests include the breath test, which is widely accepted by patients but burdened by diagnostic doubts on the part of medical personnel. Diagnostic confirmation is therefore greatly conditioned by clinical subjectivity and objectivity, as well as by the response to medical therapy. In cases of declared malabsorption, medical therapy is necessary by means of appropriate diet, prebiotics, probiotics and antibiotics. The difficulty in identifying the specific bacterial population and the part of the digestive tract that is affected indicate the appropriateness of a broad-spectrum antibiotic therapy, capable of eradicating aerobes and anaerobes, preferably with a topical rather than a general action, frequently cause of undesired effects.

Acid exposure of proximal esophagus in healthy subjects

BACKGROUND

An association between gastroesophageal reflux (GER) and pulmonary or laryngeal diseases has been recognized, and dual pH monitoring of both distal and proximal esophagus has been proposed to investigate chronic respiratory symptoms of unexplained etiology. However, the degree of acid reflux in the upper esophagus is still uncertain, making it difficult to discriminate between physiological and abnormal GER.

AIM

To define normal values for proximal esophageal acid exposure.

METHODS

Two-level esophageal pH monitoring was performed in 22 healthy subjects and 26 reflux patients. A dual pH sensor with electrodes spaced 15 cm that were positioned 5 and 20 cm above cardias was used. Two different thresholds of pH 4 and 5 were used to evaluate GER at proximal level.

RESULTS

In healthy subjects, at proximal level, the acid exposure time (% time pH < 4) was 0.4%, 0.7% and 0.1% for 24-hrs, upright and recumbent periods, respectively. Using pH 5 as threshold, acid exposure time (% time pH < 5) was 1.5%, 2.3% and 0.3% for 24-hrs, upright and recumbent periods, respectively. Twenty cm above cardias, acid exposure was greater in reflux patients in comparison to controls; however, all reflux values were significantly different between the two groups only when pH 5 was used as threshold. The percentage of distal reflux reaching the proximal site (16.0%, 27.9% and 7.1% in controls for 24-hrs, upright and recumbent periods, respectively) was similar in the two groups.

CONCLUSIONS

Acid reflux, to a limited extent, is physiologic in proximal esophagus. The technique of pH recording 20 cm above cardias might be useful in documenting the cephalic extend of GER, allowing to investigate patients with atypical presentations of GER disease. It may be best to use both thresholds 4 and 5 for evaluating proximal acid exposure.

[Esophageal motor disorders in patients with dysphagia]

Endoscopy and radiology are usually suggested as the first line investigations in patients with dysphagia. Esophageal manometry is indicated if the above studies are unfruitful. Our aim was to evaluate the role of manometry in diagnosing motor disorders of the esophagus in patients with non-organic dysphagia. We retrospectively evaluated the results of seven years' experience with esophageal manometry performed in 114 patients with difficulty in swallowing not due to esophageal structural lesions or reflux esophagitis, both escluded by endoscopic and/or radiologic studies prior to manometric investigation. A variety of nonspecific esophageal motor disorders were the most common (32%) manometric abnormalities seen in patients with dysphagia. Achalasia was common (23%) too, whereas diffuse esophageal spasm (8%), nutcracker esophagus (6%) and hypertensive LES (1%) accounted for a few motility disorders associated with dysphagia. Low LES pressure was found in 3% of the patients, suggesting gastroesophageal reflux as the cause of their difficulty in swallowing. The study confirms the role of esophageal manometry in diagnosing the cause of a swallowing disorder, identified in 83 out of 114 patients (73%). Achalasia and nonspecific esophageal motor disorders accounted for more than 50% of the motility disorders in patients with dysphagia.

Syphilis and blood donors: comparison of two different diagnostic strategies

In this study the validity of the methods provided for by Italian law (VDRL or RPR tests) were compared with the diagnostic strategy suggested by WHO (the use of VDRL and TPHA tests in parallel). Sensitivity, specificity and posterior probability of infection after a positive or a negative result were estimated. The application of two tests in parallel produces a statistically significant increase of sensitivity from 47% to 98% while the increase of proportion of false positives is not significant (from 15% to 16%). Probability of infection when the result is negative to the RPR is 0.07% while a negative result to the RPR and the TPHA tests has a probability to be really infected of 0.003%. The use of the two tests (RPR and TPHA) in parallel is able to give the highest degree of sensitivity, indispensable to select possible blood donors, while maintaining a good degree of specificity. The authors concluded that the use of VDRL alone does not exclude infectivity of a blood sample, and in accordance with WHO and international recommendations, the VDRL or RPR and TPHA tests should be used in parallel for syphilis screening.