Referral for liver transplant following acute variceal bleeding: a multicenter cohort study

OBJECTIVES

Referral for liver transplant (LT) following acute variceal bleeding (AVB) varies widely. We aimed to characterize and assess its impact on clinical outcomes.

METHODS

Observational retrospective cohort including cirrhosis patients with AVB from 3 hospitals in Lisbon, Portugal, from 2018 to 2019. Primary exposure was referral for LT and primary endpoint was all-cause mortality within 2 years of index hospital admission.

RESULTS

Among 143 patients, median (IQR) age was 59 (52-72) years and 90 (62.9%) were males. Median (IQR) MELDNa scores on hospital admission and discharge were 15 (11-21) and 13 (10-16), respectively. Overall, 30 (21.0%) patients were assessed for LT, 13 (9.1%) prior to and 17 (11.9%) within 2 years of hospital admission. Overall, 58 (40.6%) patients had at least one potential contra-indication for transplant. LT was performed in 3 (2.1%) patients (among 5 listed). Overall, 34 (23.8%) and 62 (43.4%) patients died at 6 weeks and 2 years post hospital admission, respectively. Following adjustment for confounders, referral for LT was associated with lower 2-year mortality (aHR (95% CI) = 0.20 (0.05-0.85)).

CONCLUSION

In a multicenter cohort of cirrhosis patients with AVB, less than a quarter underwent formal LT evaluation. Improved referral for LT following AVB may benefit cirrhosis patients' longer-term mortality.

Endoscopic Retrograde Cholangiopancreatography on Pediatric Patients: Experience of a Portuguese Adult Gastroenterology Department

Introduction

Experience with endoscopic retrograde cholangiopancreatography (ERCP) in the pediatric population is limited. Few medical centers have experts specifically trained in pediatric therapeutic endoscopy. As a result, patients are generally referred to adult endoscopists with high experience in the procedure. The aim of this study was to characterize the experience of an adult endoscopy unit with ERCP on pediatric patients, with a special focus on very young patients.

Methods

We retrospectively analyzed indications, technical success rate, final clinical diagnosis, and complications of ERCPs in children <18 years at our tertiary referral hospital center between January 1994 and June 2022.

Results

Sixty-five ERCPs were performed on 57 children with a median age of 13 years (range 1-17 years). Eleven ERCPs were performed on 9 patients up to 5 years old. Indications for ERCP were as follows: biliary obstruction (n = 40), mainly due to choledocholithiasis, lithiasic acute pancreatitis (n = 19), recurrent pancreatitis (n = 3), stent extraction (n = 2), and post-operative biliary fistula (n = 1). The cannulation success rate was 95.1%. Therapeutic interventions were performed in 79% of ERCP. All patients were followed up as inpatients. Complications were recorded in two procedures (3.1%), and no procedure-related mortality occurred.

Conclusion

In our experience, ERCP in children can be safely performed with high success rates by advanced adult-trained expert endoscopists at a high-volume center.

Is Metformin Associated with a Lower Prevalence of Polyps, Adenomas, and Colorectal Carcinoma in Patients with Diabetes Mellitus?

PURPOSE

Recent studies suggested a protective role of metformin in the development of colorectal cancer (CRC) and its precursors. We aimed to investigate if metformin was associated with a lower prevalence and number of colorectal polyps in diabetic patients and also adenomas, high-risk adenomas, and CRC.

METHODS

Retrospective study on adult patients with diabetes mellitus followed in our hospital with a total colonoscopy between 2015 and 2019, treated with either metformin for > 5 years or other antidiabetic agent (control group). We assessed the number, size, and histopathology examination of proliferative lesions detected on colonoscopy.

RESULTS

We included 401 patients aged 69 ± 9 years, 57% males, divided into two groups: treated with metformin (n = 260) and without (n = 141). The number of polyps detected was significantly lower in patients under metformin (p = 0.014). There was a nonsignificant trend towards lower polyp detection rates in the metformin compared to the control group both in unadjusted analysis (50% vs 60%, p = 0.058) and multivariable adjusted analysis (odds ratio [OR] 0.68, 95% confidence interval [CI] 0.43-1.09, p = 0.111). In the latter, we identified male gender (OR 2.24, 95%CI 1.44-3.49, p < 0.001), age (OR 1.35 for every 10 years, 95%CI 1.07-1.71, p = 0.012), glycated hemoglobin value (OR 1.20 for every 1% increase, 95%CI 1.06-1.37, p = 0.005), and hypertension (OR 1.76, 95%CI 1.01-3.08, p = 0.046) as factors associated with a higher prevalence of polyps. We saw no statistically significant differences regarding adenoma (p = 0.231), high-risk adenoma (p = 0.810), and CRC (p = 0.705) diagnoses between groups.

CONCLUSION

In our study, metformin was associated with less colorectal polyps in diabetic patients compared to other treatment modalities. We observed a nonsignificant trend towards lower polyp detection rates in the metformin group both in unadjusted and adjusted analyses.

Deep-sea mining: using hyperbaric conditions to study the impact of sediment plumes in the subtidal clam Spisula solida

With the growing interest to exploit mineral resources in the deep-sea, there is the need to establish guidelines and frameworks to support hazard and risk assessment schemes. The present study used a subtidal species of filter-feeding bivalve, the clam Spisula solida, as a proxy to better understand the impacts of sediment plumes in marine organisms under hyperbaric conditions. Four concentrations of suspended sediments (0 g/L, 1 g/L, 2 g/L, and 4 g/L) were used in a mixture with different grain sizes at 4 Bar for 96 h. Functional (filtration rate-FR) and biochemical endpoints (catalase-CAT, glutathione s-transferase-GST, and lipid peroxidation-LPO) were analyzed in the gonads, digestive gland, and gills of S. solida after a 96-h exposure at 4 Bar (the natural limit of the species vertical distribution). The FR showed a decreasing trend with the increasing sediment concentrations (significant effects at 2 and 4 g/L). Additionally, significant changes were observed for some of the tested oxidative stress biomarkers, which were concentration and tissue-dependent, i.e., CAT activity was significantly elevated in gills (1 g/L treatment), and GST was decreased in digestive gland (1 g/L treatment). Overall, the results show that suspended sediments, at 2 and 4 g/L, have negative functional impacts in the bivalve S. solida providing additional insights to improve hazard assessment of deep-sea mining. These findings represent a step forward to ensure the mitigation of the potential negative effects of deep-sea resource exploitation.

Gastrointestinal Symptoms and Liver Injury on Admission in a Hospitalised Population with COVID-19 Infection

N/a.

Functional, biochemical and molecular impact of sediment plumes from deep-sea mining on Mytilus galloprovincialis under hyperbaric conditions

The deep-sea is the biggest ecosystem in the world and despite the extreme conditions that characterize it, is highly biodiverse and complex. Deep-sea mining has been foreseen as a potential and concerning new stressor, and among the deep-sea mining associated stressors, sediment plumes, likely to be released into the water column as a side effect of mining, can reach habitats within a radius of more than a hundred kilometers. The present study examined the effects of suspended sediments of different grain sizes (63-125 μm, 125-250 μm and 250-500 μm) in the model species Mytilus galloprovincialis, at 4 bar, as a proxy to address the potential effects of sediment plumes, in the water column, with different grain sizes under high pressure conditions. Functional (filtration rate - FR), biochemical (catalase - CAT, glutathione s-transferase - GST, lipid peroxidation - LPO) and molecular (gene expression of [actin (ACTN), glutathione S-transferase alpha (GSTA), superoxide dismutase 2 (SOD2), catalase (CAT), heat shock protein 60 (HSP60), cytochrome c oxidase (COI) and DNA mismatch repair protein (MSH6)]) endpoints were studied in juvenile organisms. The FR decreased significantly for all tested grain size ranges, with a more severe effect for the particles with a diameter between 63 and 125 μm. In addition to the FR, significant changes were also observed for all tested biomarkers. Gene expression was significantly downregulated for CAT and ACTN. Overall, this study demonstrated that the smaller sized particles are the ones leading to more severe effects. Given their high dispersion potential and longer suspension periods under mining operation scenarios, particular attention should be given to the release of sediment plumes that may affect deep-sea environments and the water column. It is, therefore, vital to create standards and guidelines for sustainable mining practices.

Primary Liver Lymphoma Presenting as Liver Nodules

The liver is usually affected in advanced stages of lympho-proliferative diseases, but primary liver lymphomas (PLLs) are rare. The diagnosis is usually late, especially in patients without identifiable risk factors, with consequent worse prognosis. We report the case of a 59-year-old female with progressive worsening pain in the right hypochondrium and weight loss. She was previously healthy and had a family history of gastrointestinal and gynecologic neoplasms. During the initial investigation, three liver nodules suggestive of liver metastases were found. Nevertheless, no primary neoplasm was identified in a subsequent evaluation with imaging and endoscopic exams. Laboratory exams excluded hepatic infections, metabolic diseases, and acquired immunosuppression. Biopsy of the lesions revealed diffuse large B-cell lymphoma. Lymph node and medullar involvement were excluded, and the diagnosis of PLL was assumed. The patient started chemotherapy with R-CHOP. With this case, we intend to alert for this differential diagnosis of liver nodules, even in the absence of predisposing conditions for lymphoma. We point out the need to define universal diagnosis criteria for this pathology.

Endoscopic Management of Sigmoid Volvulus in a Debilitated Population: What Relevance?

Background

Colonic volvulus, mainly from the sigmoid, is a relatively common cause of intestinal obstruction, particularly in the elderly and in patients with debilitating conditions. The high morbi-mortality of emergency surgery places the endoscopic approach as the first-line treatment for the resolution of this acute obstructive condition.

Objectives

To assess the importance of endoscopic treatment for the resolution of colonic volvulus in a debilitated population.

Method

This is a retrospective analysis of emergency lower gastrointestinal endoscopies in patients with colonic volvulus as diagnosis, performed over a 9-year period (2009-2018), as well as population characterization and follow-up after the first exam.

Results

We performed 88 procedures in 52 patients (56.4% males, median age 83 years, range 33-94). Endoscopic resolution was effective in 86.4% (76/88) of the exams, without procedure complications. Eighty-one percent of patients presented with volvulus recurrence, 50% of which occurred during the 3 months after the initial procedure. Twenty-one were submitted to surgery, 12 of which were emergency procedures after endoscopic failure as the primary treatment (5 of which had mucosal necrosis at endoscopy). There was no mortality in elective surgery. In the emergency plus necrosis group, mortality was 60% (3/5) and 14.3% (1/7) in the emergency without necrosis group.

Conclusions

Despite the high recurrence of volvulus after endoscopic treatment, it seems to be an adequate and low-risk first-line therapy for sigmoid volvulus in debilitated patients, allowing improvement of surgical conditions.

Is the dendritic organ of the striped eel catfish Plotosus lineatus an ammonia excretory organ?

The dendritic organ (DO) is a salt secretory organ in the Plotosidae marine catfishes. The potential role of the DO in ammonia excretion was investigated by examining the effects of salinity [brackishwater (BW 3‰), seawater (SW 34‰) and hypersaline water (HSW 60‰)] acclimation and DO ligation on ammonia excretion and ammonia transporter expression by immunohistochemistry (IHC), immunoblotting (IB) and qPCR. Ammonia flux rates (J_Amm) were significantly lower in BW compared to SW and HSW. DO ligation resulted in a significantly lower J_Amm in SW but not BW fish. IHC demonstrated apical and basolateral localization of Rhesus-associated glycoprotein (Rhag-like) and Rhbg-like proteins, respectively, in parenchymal cells of the DO acini. In the gills, which are the primary site of ammonia excretion in teleost fishes, IHC showed an apical localization of Rhag-like protein in some Na⁺/K⁺-ATPase (NKA) immunoreactive (IR) cells limited to a few interlamellar regions of the filament and, in both apical and basolateral membranes of pillar cells irrespective of treatment group. In gills, the distribution of NKA-IR cells showed no salinity and/or ligation dependency. IB of Rhag and Rhbg-like proteins was found only in the gills and expression levels did not change with salinity but ligation in BW decreased Rhbg-like levels. Although Rhcg was not detected with heterologous antibodies, rhcg1 mRNA expression was detected in both gills and DO. HSW was associated with the lowest expression in DO and ligations in SW and BW were without effect on branchial expression levels. Taken together these results indicate the DO potentially has a physiological role in ammonia excretion under SW conditions.

Ecotoxicology of deep-sea environments: Functional and biochemical effects of suspended sediments in the model species Mytilus galloprovincialis under hyperbaric conditions

The deep-sea is the biggest ecosystem in the world and is characterized by extreme conditions such as high pressure, low temperatures and absence or limited light. Despite the scarce studies due to inaccessibility, these ecosystems are considered highly biodiverse. The deep-sea is subjected to anthropogenic stressors with deep-sea mining being a likely new form of disruption. Understanding how it affects the surrounding environments is paramount to develop guidelines to protect sensitive habitats and allow for responsible exploitation of resources. One of the potential stressors associated with deep-sea mining are the sediment laden plumes that can be generated during the mining process. The present study examined, for the first time, the effects of suspended sediments (0, 1, 2 and 4 g/L) in the model mussel species, Mytilus galloprovincialis, under hyperbaric conditions (1, 4 and 50 Bar). Functional endpoints, i.e. feeding assays, together with biochemical biomarkers of oxidative stress [catalase (CAT), lipid peroxidation (LPO), glutathione-s-transferase (GST) and superoxide dismutase (SOD)] were studied in juvenile mussels. The filtration rate (FR) of M. galloprovincialis decreased with the increment in the sediment concentrations, for all tested pressure conditions (1, 4 and 50 Bar). Significant alterations were also observed for all tested biomarkers, being sediment and pressure-dependent. Interestingly, pressure had an effect in GST activity, that increased in the 4 and 50 Bar experiments in comparison with the results at 1 Bar. Remarkably, filtration rates were significantly affected by pressure. These findings will support the filling of the knowledge gaps related with the hazard assessment of deep-sea mining associated stressors.

Effect of dendritic organ ligation on striped eel catfish Plotosus lineatus osmoregulation

Unique amongst the teleost, Plotosidae catfish possess a dendritic organ (DO) as a purported salt secreting organ, whereas other marine teleosts rely on their gill ionocytes for active NaCl excretion. To address the role of the DO in ionregulation, ligation experiments were conducted in brackish water (BW) 3‰ and seawater (SW) 34‰ acclimated Plotosus lineatus and compared to sham operated fish. Ligation in SW resulted in an osmoregulatory impairment in blood (elevated ions and hematocrit) and muscle (dehydration). However, SW ligation did not elicit compensatory changes in gill or kidney Na⁺/K⁺-ATPase (NKA) activity and/or protein expression while a decrease in anterior intestine and increased in posterior intestine were observed but this was not reflected at the protein level. Following ligation in SW, protein levels of carbonic anhydrase (CA) and V-ATPase B subunit (VHAB) were higher in kidney but either lower (CA) or unchanged (VHAB) in other tissues. Taken together, the osmotic disturbance in ligated SW fish indicates the central role of the DO in salt secretion and the absence of a compensatory response from the gill.

Osmoregulation in the Plotosidae Catfish: Role of the Salt Secreting Dendritic Organ

Unlike other marine teleosts, the Plotosidae catfishes reportedly have an extra-branchial salt secreting dendritic organ (DO). Salinity acclimation [brackishwater (BW) 3aaa, seawater (SWcontrol) 34aaa, and hypersaline water (HSW) 60aaa] for 14 days was used to investigate the osmoregulatory abilities of Plotosus lineatus through measurements of blood chemistry, muscle water content (MWC), Na⁺/K⁺-ATPase (NKA) specific activity and ion transporter expression in gills, DO, kidney and intestine. Ion transporter expression was determined using immunoblotting, immunohistochemistry (IHC) and quantitative polymerase chain reaction (qPCR). HSW elevated mortality, plasma osmolality and ions, and hematocrit, and decreased MWC indicating an osmoregulatory challenge. NKA specific activity and protein levels were significantly higher in DO compared to gill, kidney and intestine at all salinities. NKA specific activity increased in kidney and posterior intestine with HSW but only kidney showed correspondingly higher NKA α-subunit protein levels. Since DO mass was greater in HSW, the total amount of DO NKA activity expressed per gram fish was greater indicating higher overall capacity. Gill NKA and V-ATPase protein levels were greater with HSW acclimation but this was not reflected in NKA activity, mRNA or ionocyte abundance. BW acclimation resulted in lower NKA activity in gill, kidney and DO. Cl^- levels were better regulated and the resulting strong ion ratio in BW suggests a metabolic acidosis. Elevated DO heat shock protein 70 levels in HSW fish indicate a cellular stress. Strong NKA and NKCC1 (Na⁺:K⁺:2Cl^- cotransporter1) co-localization was observed in DO parenchymal cells, which was rare in gill ionocytes. NKCC1 immunoblot expression was only detected in DO, which was highest at HSW. Cystic fibrosis transmembrane regulator Cl^- channel (CFTR) localize apically to DO NKA immunoreactive cells. Taken together, the demonstration of high NKA activity in DO coexpressed with NKCC1 and CFTR indicates the presence of the conserved secondary active Cl^- secretion mechanism found in other ion transporting epithelia suggesting a convergent evolution with other vertebrate salt secreting organs. However, the significant osmoregulatory challenge of HSW indicates that the DO may be of limited use under more extreme salinity conditions in contrast to the gill based ionoregulatory strategy of marine teleosts.

The last frontier: Coupling technological developments with scientific challenges to improve hazard assessment of deep-sea mining

The growing economic interest in the exploitation of mineral resources on deep-ocean beds, including those in the vicinity of sensitive-rich habitats such as hydrothermal vents, raise a mounting concern about the damage that such actions might originate to these poorly-know ecosystems, which represent millions of years of evolution and adaptations to extreme environmental conditions. It has been suggested that mining may cause a major impact on vent ecosystems and other deep-sea areas. Yet, the scale and the nature of such impacts are unknown at present. Hence, building upon currently available scientific information it is crucial to develop new cost-effective technologies embedded into rigorous operating frameworks. The forward-thinking provided here will assist in the development of new technologies and tools to address the major challenges associated with deep sea-mining; technologies for in situ and ex situ observation and data acquisition, biogeochemical processes, hazard assessment of deep-sea mining to marine organisms and development of modeling tools in support of risk assessment scenarios. These technological developments are vital to validate a responsible and sustainable exploitation of the deep-sea mineral resources, based on the precautionary principle.

Outcomes of Different Methods for Analysis of Biliary Brush Cytology and of Factors Associated with Positive Diagnosis in an Age-Dependent Retrospective Review

Background and Aims

Brush cytology during endoscopic retrograde cholangiopancreatography (ERCP) is the most frequently used strategy for obtaining a tissue sample from an indeterminate biliary stricture. A recent study reported that age is a factor associated with positive yields, but further analysis of how age influences the results was lacking. We aimed to evaluate clinical effectiveness of biliary cytology and prognostic factors for a positive outcome, especially age.

Methods

This study was a single-center, retrospective, clinical study of 77 consecutive patients who underwent brush cytology during ERCP to obtain a diagnosis of an indeterminate biliary stricture. We compared 2 routine cytology techniques: A (smear); B (centrifugation of the cytological material collected and the cut-off brush + cell block when sufficient amount of material was available). The data were collected aiming to compare the accuracy of the different techniques used and the prognostic factors affecting the outcome, with a particular focus on age. The yield for brush cytology was compared with the gold standard defined as either definitive histology or the long-term clinical course.

Results

The overall accuracy of the 2 used methods was 75.3%. Sensitivity was 52.5%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 66.1%. Although not statistically significant, there was a trend toward accuracy for method B compared with method A (80.4 vs. 65.4%; p = 0.153). Multiple logistic regression analysis showed that younger age was the only independent prognostic factor associated with a positive diagnosis (OR 0.95; 95% CI 0.90-0.99; p = 0.039). Receiver operating characteristic curves for age yielded an area under the curve value of 68.2%. On the basis of the Youden index, 69 years was found to be the optimal cutoff for age.

Conclusions

In this series, the accuracy of routine biliary brush cytology was not equal for all methods and ages; in particular, younger patients (below 69 years) tended to have a higher probability of a correct diagnosis.

Cortisol plays a role in the high environmental ammonia associated suppression of the immune response in zebrafish

Exposure to high environmental ammonia (HEA) levels increases the vulnerability of fishes to parasitic, viral and bacterial diseases. We tested the hypothesis that elevated plasma cortisol levels play a role in the HEA-mediated immunosuppression in fishes. To this end, we tested the effect of exogenous cortisol treatment on the lipopolysaccharide (LPS)-induced immune response in zebrafish (Danio rerio). Also, to test whether glucocorticoid receptor (GR) signaling is involved in HEA-mediated immunosuppression, zebrafish were treated with mifepristone, a GR antagonist, and the LPS-induced immune response assessed after HEA exposure. We evaluated a panel of important immunity-related genes including interleukin 1β (il1b) and suppressor of cytokine signaling (socs-1a, 2, 3) and acute phase response genes [serum amyloid A (saa), transferrin (tfa), leukocyte cell-derived chemotaxin 2-like (lect2l), haptoglobin (hp), hepcidin (=hepatic anti-microbial peptide hamp), and complement component 3b (c3b)] by real-time quantitative PCR. Our results demonstrate that exogenous cortisol administration as well as elevated cortisol levels in response to HEA exposure modulate mRNA transcript levels of key mediators of the innate immune response in zebrafish. Mifepristone treatment reduced whole body cortisol levels and eliminated the HEA-mediated changes in transcript abundance of socs1a, il1b, as well as APR genes. Together, these results suggest that the HEA effect on the innate immune response is in part mediated by cortisol signaling, while the mode of action, including the receptors involved remains to be elucidated.

A cytosolic carbonic anhydrase molecular switch occurs in the gills of metamorphic sea lamprey

Carbonic anhydrase plays a key role in CO2 transport, acid-base and ion regulation and metabolic processes in vertebrates. While several carbonic anhydrase isoforms have been identified in numerous vertebrate species, basal lineages such as the cyclostomes have remained largely unexamined. Here we investigate the repertoire of cytoplasmic carbonic anhydrases in the sea lamprey (Petromyzon marinus), that has a complex life history marked by a dramatic metamorphosis from a benthic filter-feeding ammocoete larvae into a parasitic juvenile which migrates from freshwater to seawater. We have identified a novel carbonic anhydrase gene (ca19) beyond the single carbonic anhydrase gene (ca18) that was known previously. Phylogenetic analysis and synteny studies suggest that both carbonic anhydrase genes form one or two independent gene lineages and are most likely duplicates retained uniquely in cyclostomes. Quantitative PCR of ca19 and ca18 and protein expression in gill across metamorphosis show that the ca19 levels are highest in ammocoetes and decrease during metamorphosis while ca18 shows the opposite pattern with the highest levels in post-metamorphic juveniles. We propose that a unique molecular switch occurs during lamprey metamorphosis resulting in distinct gill carbonic anhydrases reflecting the contrasting life modes and habitats of these life-history stages.

Effects of salinity on upstream-migrating, spawning sea lamprey, Petromyzon marinus

The sea lamprey, Petromyzon marinus, is an anadromous, semelparous species that is vulnerable to endangered in parts of its native range due in part to loss of spawning habitat because of man-made barriers. The ability of lampreys to return to the ocean or estuary and search out alternative spawning river systems would be limited by their osmoregulatory ability in seawater. A reduction in tolerance to salinity has been documented in migrants, although the underlying mechanisms have not been characterized. We examined the capacity for marine osmoregulation in upstream spawning migrants by characterizing the physiological effects of salinity challenge from a molecular perspective. Estuarine-captured migrants held in freshwater (FW) for ∼1 week (short-term acclimation) or 2 months (long-term acclimation) underwent an incremental salinity challenge until loss of equilibrium occurred and upper thresholds of 25 and 17.5, respectively, occurred. Regardless of salinity tolerance, all lamprey downregulated FW ion-uptake mechanisms [gill transcripts of Na(+):Cl(-) cotransporter (NCC/slc12a3) and epithelial Na(+) channel (ENaC/scnn1) and kidney Na(+)/K(+)-ATPase (NKA) protein and activity but not transcript]. At their respective salinity limits, lamprey displayed a clear osmoregulatory failure and were unable to regulate [Na(+)] and [Cl(-)] in plasma and intestinal fluid within physiological limits, becoming osmocompromised. A >90% drop in haematocrit indicated haemolysis, and higher plasma concentrations of the cytosolic enzymes alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase indicated damage to other tissues, including liver. However, >80% of short-term FW-acclimated fish were able to osmoregulate efficiently, with less haemolysis and tissue damage. This osmoregulatory ability was correlated with significant upregulation of the secretory form of Na(+):K(+):2Cl(-) cotransporter (NKCC1/slc12a2) transcript levels and the re-emergence of seawater-type ionocytes detected through immunohistochemical NKA immunoreactivity in the gill, the central ionoregulatory organ. This work sheds light on the molecular and physiological limits to the potential return to seawater for lampreys searching for alternative FW systems in which to spawn.

Pneumatose Cólica Tratada com Metronidazol e Oxigenoterapia Hiperbárica: Um Caso de Sucesso

Pneumatosis intestinalis, characterized by the presence of gas within the bowel wall, is an uncommon condition with variable<br />presentation. It may be idiopathic or secondary to other diseases. A computed tomography scan is the most sensitive method for diagnosis. In the absence of signs and symptoms of complications, such as perforation and peritonitis, pneumatosis intestinalis can be<br />managed conservatively. We present the case of a 59-year-old woman with pneumatosis coli secondary to benign ovary teratoma. After surgery she remained symptomatic and was successfully treated with metronidazole and hyperbaric oxygen therapy.

[Pneumatosis Coli Treated with Metronidazole and Hyperbaric Oxygen Therapy: A Successful Case]

Pneumatosis intestinalis, characterized by the presence of gas within the bowel wall, is an uncommon condition with variable presentation. It may be idiopathic or secondary to other diseases. A computed tomography scan is the most sensitive method for diagnosis. In the absence of signs and symptoms of complications, such as perforation and peritonitis, pneumatosis intestinalis can be managed conservatively. We present the case of a 59-year-old woman with pneumatosis coli secondary to benign ovary teratoma. After surgery she remained symptomatic and was successfully treated with metronidazole and hyperbaric oxygen therapy.

Comparative effect of a new mouthrinse containing chlorhexidine, triclosan and zinc on volatile sulphur compounds: a randomized, crossover, double-blind study

AIM

The aims of this study were to compare the volatile sulphur compounds (VSC)-reducing effect of two commercial mouthrinses using a morning bad breath model and to assess the role of mechanical plaque control (MPC) when performed previously to mouthrinse use.

PATIENTS AND METHODS

Eleven volunteers with good oral health were enrolled in a double-blind, randomized, six-step crossover design study with a 7-day washout period. Two commercial mouthrinses were tested using a saline solution (NaCl 0.9%) as a negative control: one mouthrinse contained 0.05% chlorhexidine, 0.05% cetylpyridinium chloride and 0.14% zinc lactate (CHX-CPC-Zn), while the other contained 0.05% chlorhexidine, 0.15% triclosan and 0.18% zinc pidolate (CHX-triclosan-Zn). A portable sulphide monitor (Halimeter(®) ) was used for VSC quantification. Measurements were made at baseline, and 1, 3 and 5 h after rinsing. Significant differences were detected by analysis of variance.

RESULTS

No significant differences between groups were detected at baseline. We were unable to demonstrate a significant influence of mechanical plaque control on the reduction of VSC levels when performed before mouthrinse use (P = 0.631). Both mouthrinses effectively lowered VSC levels in all test intervals (P < 0.05). No statistically significant differences were found between mouthrinses in any of the test intervals (P = 0.629, 0.069 and 0.598 at 1, 3 and 5 h).

CONCLUSION

This study demonstrated that CHX-CPC-Zn and CHX-triclosan-Zn have significant and similar effects in reducing VSC levels, which persist for at least 5 h. Such effects were independent of previous MPC, which failed to improve on the results of mouthrinse use alone.

P2X7-induced zeiosis promotes osteogenic differentiation and mineralization of postmenopausal bone marrow-derived mesenchymal stem cells

Polymorphisms of the P2X7 receptor have been associated with increased risk of fractures in postmenopausal women. Although both osteoblasts and osteoclasts express P2X7 receptors, their function in osteogenesis remains controversial. Here, we investigated the role of the P2X7 receptor on osteogenic differentiation and mineralization of bone marrow mesenchymal stem cell (BMSC) cultures from postmenopausal women (age 71±3 yr, n=18). We focused on the mechanisms related to intracellular [Ca(2+)]i oscillations and plasma membrane-dynamics. ATP, and the P2X7 agonist BzATP (100 μM), increased [Ca(2+)]i in parallel to the formation of membrane pores permeable to TO-PRO-3 dye uptake. ATP and BzATP elicited reversible membrane blebs (zeiosis) in 38 ± 1 and 70 ± 1% of the cells, respectively. P2X7-induced zeiosis was Ca(2+) independent, but involved phospholipase C, protein kinase C, and Rho-kinase activation. BzATP (100 μM) progressively increased the expression of Runx-2 and Osterix transcription factors by 452 and 226% (at d 21), respectively, alkaline phosphatase activity by 88% (at d 28), and mineralization by 329% (at d 43) of BMSC cultures in a Rho-kinase-dependent manner. In summary, reversible plasma membrane zeiosis involving cytoskeleton rearrangements due to activation of the P2X7-Rho-kinase axis promotes osteogenic differentiation and mineralization of BMSCs, thus providing new therapeutic targets for postmenopausal bone loss.

The inhibitory effect of environmental ammonia on Danio rerio LPS induced acute phase response

Ammonia is a toxic by-product of amino acid catabolism and a common environmental pollutant that has been associated with increased disease susceptibility in fish although the mechanism is not well understood. We addressed the hypothesis that elevated environmental ammonia acts by impairing the acute phase response (APR). Specifically, we determined the impact of sub-lethal acute (24 h) and chronic (14 d) ammonia exposure on acute phase protein gene expression in zebrafish (Danio rerio) in response to a challenge with bacterial lipopolysaccharide (LPS: i.p. 10 μg/g after 24h). A panel of LPS-responsive genes (SAA, HAMP, LECT2, Hp and IL1β) were identified and evaluated by real-time quantitative PCR. Ammonia was found to impair induction of SAA, HAMP and LECT2 by 50-90%. Both short (15 min, 1h and 24h) and long-term (14 days) exposure to high environmental ammonia concentrations significantly elevated whole-body cortisol levels compared with control fish. Our results reveal for the first time that exposure to high environmental levels of ammonia suppresses the innate immune response in fish. We hypothesize that high environmental ammonia-mediated elevation of cortisol levels in zebrafish may be playing a key role in this immunosuppression, while the mechanisms involved remains to be elucidated.

Mechanisms of transepithelial ammonia excretion and luminal alkalinization in the gut of an intestinal air-breathing fish, Misgurnus anguilliacaudatus

The weatherloach, Misgurnus angulliacaudatus, is an intestinal air-breathing, freshwater fish that has the unique ability to excrete ammonia through gut volatilization when branchial and cutaneous routes are compromised during high environmental ammonia or air exposure. We hypothesized that transepithelial gut NH4+ transport is facilitated by an apical Na+/H+ (NH4+) exchanger (NHE) and basolateral Na+/K+(NH4+)-ATPase, and that gut boundary layer alkalinization (NH4+ =&gt; NH3 + H+) is facilitated by apical HCO3- secretion through a Cl-/HCO3- anion exchanger. This was tested using a pharmacological approach with anterior (digestive) and posterior (respiratory) intestine preparations mounted in pH-stat equipped Ussing chambers. The anterior intestine had a markedly higher conductance, short circuit current and net base (Jbase) and ammonia excretions rates (Jamm) than posterior intestine. In anterior intestine, HCO3- accounted for 70% Jbase. In the presence of an imposed serosal-mucosal ammonia gradient, both NHE and Na+/K+-ATPase inhibitors EIPA (0.1mM) and ouabain (0.1mM) significantly inhibit Jamm in the anterior intestine, although only the former in the posterior intestine. In addition, the anion exchange inhibitor DIDS significantly reduced Jbase in anterior intestine although only at a high dose (1mM). Carbonic anhydrase does not appear to be associated with gut alkalization under these conditions since etoxzolamide was without effect on Jbase. Membrane fluidity of the posterior intestine was low suggesting low permeability, which was also reflected in a lower mucosal-serosal Jamm in the presence of an imposed gradient in contrast to the anterior intestine. To conclude although the posterior intestine is highly modified for gas exchange, it is the anterior intestine that is the likely site of ammonia excretion and alkalinization leading to ammonia volatilization in the gut.

The effect of elevated hydrostatic pressure upon selected biomarkers in juvenile blackspot seabream Pagellus bogaraveo in a 14 day-long experiment

Hydrostatic pressure elevated to 500 kPa for 14 days was found to affect hepatic 7-ethoxyresorufin-O-deethylase (EROD), oxidized protein (POx), protein yield and branchial Na(+)-K(+)-ATPase. No effect on glutathione-S-transferase (GST), superoxidase dismutase (SOD), catalase (CAT), lipid peroxidation (LP), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), condition factor (K) and hepato-somatic index (I(H)) was encountered.

Water-soluble fraction of mercury, arsenic and other potentially toxic elements in highly contaminated sediments and soils

The water-soluble contents of mercury, arsenic and other potentially toxic elements in highly contaminated sediment and soil samples from Portugal were determined. Mercury and arsenic concentrations were detectable and reproducible among replicate experiments. Despite the acidic pH, the low organic carbon content and the exceptionally high levels of contamination of certain samples (total mercury contents varied between 0.15 and 3180 mg kg(-1) while total arsenic concentrations ranged from 11 to 6365 mg kg(-1)), the water-soluble percentages of both mercury (<1.2%) and arsenic (<4.6%) were generally low. The variability of the water-soluble fractions of these two elements among these samples and at the occurring pH conditions seems not to be associated with the release of other potentially toxic elements. The highest water-soluble concentrations of the remaining potentially toxic elements were generally observed in the 15-25 cm depth layer of sediments from areas colonised with plants (Halimione portulacoides) and in mining soil samples. Zinc, cobalt, copper and cadmium showed the highest water-soluble percentages of elements in relation to total metal contents. Given the high contamination levels, the availability of potentially toxic elements in these areas as well as possible risks to the environment and humans should be further investigated. The presence of plants (H. portulacoides) appears to cause significant changes in the sediment matrix that increase the mobility of several potentially toxic elements, particularly in the 15-25 cm depth layer. The effects of vegetation on the fractionation of potentially toxic elements on these sediments should be further studied.

Branchial ammonia excretion in the Asian weatherloach Misgurnus anguillicaudatus

The weatherloach, Misgurnus anguillicaudatus, is a freshwater, facultative air-breathing fish that lives in streams and rice paddy fields, where it may experience drought and/or high environmental ammonia (HEA) conditions. The aim of this study was to determine what roles branchial Na(+)/K(+)-ATPase, H(+)-ATPase, and Rhcg have in ammonia tolerance and how the weatherloach copes with ammonia loading conditions. The loach's high ammonia tolerance was confirmed as was evident from its high 96 h LC(50) value and high tissue tolerance to ammonia. The weatherloach does not appear to make use of Na(+)/NH(4)(+)-ATPase facilitated transport to excrete ammonia when exposed to HEA or to high environmental pH since no changes in activity were observed. Using immunofluorescence microscopy, distinct populations of vacuolar (V)-type H(+)-ATPase and Na(+)/K(+)-ATPase immunoreactive cells were identified in branchial epithelia, with apical and basolateral staining patterns, respectively. Rhesus C glycoprotein (Rhcg1), an ammonia transport protein, immunoreactivity was also found in a similar pattern as H(+)-ATPase. Rhcg1 (Slc42a3) mRNA expression also increased significantly during aerial exposure, although not significantly under ammonia loading conditions. The colocalization of H(+)-ATPase and Rhcg1 to the similar non-Na(+)/K(+)-ATPase immunoreactive cell type would support a role for H(+)-ATPase in ammonia excretion via Rhcg by NH(4)(+) trapping. The importance of gill boundary layer acidification in net ammonia excretion was confirmed in this fish; however, it was not associated with an increase in H(+)-ATPase expression, since tissue activity and protein levels did not increase with high environmental pH and/or HEA. However the V-ATPase inhibitor, bafilomycin, did decrease net ammonia flux whereas other ion transport inhibitors (amiloride, SITS) had no effect. H(+)-ATPase inhibition also resulted in a consequent elevation in plasma ammonia levels and a decrease in the net acid flux. In gill, aerial exposure was also associated with a significant increase in membrane fluidity (or increase in permeability) which would presumably enhance NH(3) permeation through the plasma membrane. Taken together, these results indicate the gill of the weatherloach is responsive to aerial conditions that would aid ammonia excretion.

Ammonia sensitivity of the glass eel (Anguilla anguilla L.): salinity dependence and the role of branchial sodium/potassium adenosine triphosphatase

Eel aquaculture is capture based and thus dependent on the fishery for juvenile glass eels. This fishery typically takes place in estuaries where salinity varies and ammonia levels can be elevated. Also, during capture and transport glass eels are kept at high densities and ammonia from endogenous production can increase to toxic levels. Ammonia is known to have detrimental effects on fish growth and survival. In the present study, the salinity dependence of ammonia sensitivity in glass eels acclimated to either seawater or freshwater was determined, and the possible role of branchial sodium/potassium adenosine triphosphatase (Na+/K+ -ATPase) was investigated. Freshwater-acclimated glass eels were found to be more sensitive to ammonia with a lethal concentration to 50% of the test organisms (LC50) value for 96 h of 3.30 mM for total ammonia nitrogen (TAN) and 117 microM for un-ionized ammonia (UIA), versus values of 4.95 mM and 138 microM, respectively, for seawater-acclimated animals. Freshwater glass eels also had significantly lower body TAN levels than seawater-acclimated glass eels, although body accumulation profiles during exposure were similar. The higher branchial Na+/K+ -ATPase activities in seawater glass eels might explain this difference in sensitivity; however, activities decreased significantly with increasing ammonia levels. There was also no salinity dependence of net ammonia flux rates (0.388 micromol of TAN/g/h). Holding glass eels at high densities characteristic of transport conditions resulted in elevated ammonia concentrations to approximately 3 mM, which coincidently approaches to the freshwater LC50 value and may therefore contribute to mortality.

Is there a compromise between nutrient uptake and gas exchange in the gut of Misgurnus anguillicaudatus, an intestinal air-breathing fish?

The Asian weatherloach, Misgurnus anguillicaudatus (Cobitidae), is a facultative air-breathing teleost fish that makes use of its hindgut or intestine as an accessory air-breathing organ (ABO). The hindgut is highly modified, being well vascularized with intraepithelial capillaries, which makes it well suited for gas exchange. However, the consequences for nutrient uptake, the traditional function of the intestine are unknown. The alimentary canal was examined histologically to assess differences between the fore-, mid- and hindgut regions that have been considered as the digestive, spiral and respiratory zones, respectively. In order to characterise the potential digestive (absorptive) function of the respiratory zone we used semi-quantitative polymerase chain reaction (PCR) to detect the presence of the intestinal Na(+):glucose cotransporter (SGLT1; SLC5A1) and H(+):peptide cotransporter (PEPT1a; SLC15A1) and partially sequenced the SGLT1 and PEPT1a cDNAs. These two transporters play important roles in the absorption of carbohydrate and di-/tripeptides, respectively, in the gut of fishes and other vertebrates and were therefore used as markers for potential nutrient uptake function. We also determined their tissue distributions through semi-quantitative RT-PCR. The effects of diet composition (high protein or high carbohydrate) or fasting on gene expression were also examined. SGLT1 expression was found in kidney, liver, heart, as well as in the three zones of the gut except the most distal part of the hindgut. PEPT1a mRNA was found in heart, brain, liver, and fore- and midgut, but absent in the hindgut. Our results clearly show high expression of SGLT1 (both mRNA and protein by immunolocalization) and PEPT1a (mRNA) in the foregut and midgut correlated with the digestive region of the gut. Modulatory effects of diet on the gene expression for both SGLT1 and PEPT1a were not observed. The presence of SGLT1 transcripts in the respiratory zone of the intestine suggests an overlap in function. However, in the case of PEPT1a, the distal limit was the midgut. Thus, despite its highly modified structure, the hindgut of the loach retains some potential nutrient uptake function.

Effects of cyclic hydrostatic pressure on the brain biogenic amines concentrations in the flounder, Platichthys flesus

The present study evaluated the effects of cyclic variations of hydrostatic pressure (HP) on neurotransmitters in the whole brain of flounder. The concentrations of the biogenic amines L-3,4-dihydroxyphenylalanine (L-DOPA), dopamine (DA), norepinephrine (NE), epinephrine (E), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxytyramine (3-MT), 5-hydroxytryptamine (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) were measured. Fish were subjected to HP cyclic variations which mimic naturally occurring conditions for a period of 14 days. DA, NE and 5-HT concentrations were significantly smaller by 21, 24 and 36%, respectively, compared to control fish. The concentrations of monoamine metabolites HVA, 3-MT and 5-HIAA were also smaller than those in control fish. These results suggest that central monoaminergic systems were influenced during long exposure to cyclic HP. The decreases of central neurotransmitters content might be involved in the physiological and behavioral responses to intermittent HP in fish.

Effect of cortisol on some osmoregulatory parameters of the teleost, Oreochromis niloticus L., after transference from freshwater to seawater

This trial was conducted in order to determine the effects of cortisol on salt water acclimation of tilapia Oreochromis niloticus (L.). Tilapia (n=42) were injected intraperitoneally with cortisol and then were directly transferred from freshwater (FW) to 15‰ salt water (SW). Changes in plasma osmolality, chloride ion concentration (Cl-), plasma level of cortisol and gill Na+, K+-ATPase activity were measured at 6, 12, 24, 48, 72 and 168 hours after transference to 15‰ SW. Plasma osmolality and Cl- increased immediately after transference until 12-24 h. The fish injected with cortisol (F) showed higher plasma levels of cortisol than those from control group (C) that maintained the initial levels during the experiment. Gill Na+, K+-ATPase activity of C fish began to increase at first hours after transference and peak at 48h. The differences between gill Na+, K+-ATPase activity of F and C groups were significant (P<0.05) in FW, which confirm the effect of exogenous cortisol.

Efeito da suplementação da dieta com NaCl no crescimento de tilápia Oreochromis niloticus cultivada em diferentes salinidades

Este estudo foi realizado com o objectivo de testar o efeito de uma dieta suplementada com cloreto de sódio no crescimento de tilápia Oreochromis niloticus cultivada em água doce e em água salobra a 10 e 20‰. Foi fornecida uma dieta suplementada com 8% de NaCl durante o período de aclimatação de três semanas. Após esse período, os peixes foram diretamente transferidos para tanques com água doce e água salobra a 10 e 20‰, para o estudo do crescimento de 180 dias. A suplementação com NaCl aumentou o crescimento dos peixes cultivados em água doce nos primeiros 30 dias (P<0,05), mas não se observaram diferenças significativas entre os outros grupos. No final do ensaio, os peixes cultivados em água salobra a 10‰ apresentaram os melhores resultados de crescimento (P<0,05). Nesse período, os peixes cultivados em 20‰ de salinidade mostraram lesões externas, perda de escamas, desorientação de escamas e inchaço do abdómen.

Plasma steroid levels in female flounder (Platichthys flesus) after chronic dietary exposure to single polycyclic aromatic hydrocarbons

The chronic effects of polycyclic aromatic hydrocarbons (PAHs) on ovary development, total hepatic lipids and plasma sex- and corticosteroid levels in female flounder (Platichthys flesus) were examined. Sexually mature feral female flounder were exposed via the diet to phenanthrene (0.5, 2.5 or 12.5 nmol/g food) or chrysene (0.4 nmol/g food) for 12 weeks, during the previtellogenic phase of the annual reproductive cycle. PAH exposure did not directly affect germ cell development since no structural and/or developmental differences were observed between control and exposed fish. On the contrary, all treatments resulted in altered plasma steroid levels. The most pronounced effect was the significant decrease in plasma 17 beta-estradiol to 19 +/- 11%, 27 +/- 7%, 63 +/- 20% and 61 +/- 12% in relation to control fish, respectively, in flounders exposed to 12.5, 2.5 or 0.5 nmol phenanthrene/g food and 0.4 nmol chrysene/g food. Impaired ovarian growth was not observed, most likely because experiments were ended before the period of vitellogenesis, even though a non-significant general decline in total hepatic lipids could be observed. Moreover, all exposed flounders, except fish fed with the highest amount of phenanthrene, showed a negative correlation between plasma 17 beta-estradiol and 17 alpha-hydroxyprogesterone levels (r = -0.46). One possible explanation is that PAH action may be mediated by a specific inhibition of steroidogenic enzymes. These findings provide evidence that selected PAHs are antiestrogenic xenobiotics with the capability to impair female teleost reproductive function.

Polycyclic aromatic hydrocarbons inhibit in vitro ovarian steroidogenesis in the flounder (Platichthys flesus L.)

The in vitro effect of polycyclic aromatic hydrocarbons (PAHs) on ovarian steroidogenesis of the flounder (Platichthys flesus L.) was determined. Fully vitellogenic ovary tissue was in vitro incubated in the presence of phenanthrene, benzo[a]pyrene or chrysene, using 17alpha-hydroxyprogesterone or androstenedione as precursors. Androstenedione (A), testosterone (T) and 17beta-estradiol (E(2)) synthesised in the presence of PAHs were assayed by radioimmunoassay and results compared with control incubations. In order to establish the effect of PAHs on the steroidogenic enzyme systems cytochrome P450 17,20-lyase (P450-17,20l), 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and cytochrome P450 aromatase (P450-arom), results were also compared with the action of ketoconazole (KCZ) and aminoglutethimide (AMG), wich are, respectively, inhibitors of cytochrome P450 steroidogenic enzymes and of P450-arom. KCZ inhibited secretion of A and E(2) in 65% and T in 40%, as a consequence of inhibited P450-17,20l and P450-arom. AMG inhibited P450-arom, which resulted in decreased E(2) synthesis to approximately 50% of control incubations. All the three PAHs inhibited A secretion by approximately 50% and E(2) from 10 to 40%. Because steroid conjugation was also inhibited by phenanthrene, it could be concluded that PAH action was mediated by an inhibitory effect over P450-17,20l, 17beta-HSD and P450-arom. Except for 17beta-HSD, PAHs resembled KCZ, and P450-17,20l was the most sensitive to their inhibitory effect. In conclusion, PAHs strongly blocked the activity of P450-17,20l, a rate-limiting enzyme for conversion of C21 to C19 steroids, and showed, therefore, the potential to disrupt the reproductive cycle of fish living in polluted environments, due to impairment of steroid biosynthesis.

Multiple sclerosis and intrathecal IgA synthesis

A clinically definite diagnosis of multiple sclerosis was done in a 61 year-old woman who displayed severe cerebellar and pyramidal tract involvement. Symptoms developed 5 years before with unsteadiness of gait and difficulties in walking. Diagnosis was supported by evoked potentials studies and magnetic resonance imaging. However, the cerebrospinal fluid (CSF) analysis was very unusual. CSF albumin and IgG concentrations were normal, as well as the IgG index. In contrast, the IgA level and the IgA index were markedly increased and the local synthesis of IgA was estimated at 31.36 mg/l. Reduction by dithiotreitol did not change the IgA level. On affinity immunoblots, oligoclonal IgA bands were not detected but oligoclonal IgG bands were present. The strong local production of IgA in this patient seems to be therefore polyclonal.

Trout farm effluents: characterization and impact on the receiving streams

Effluents from three rainbow trout (Oncorhynchus mykiss) farms located in Northern Portugal were characterized and their impact on the receiving streams was evaluated. Mean fish productions in the studied fish farms were 15, 55 and 500 t of trout per year, respectively. The feeding water was abstracted from Fornelo, Inha and Coura Rivers, at flow rates ranging from 1.2 (15 t year(-1) fish farm) to 4.8 litre s(-1) per ton annual fish production (500 t year(-1) fish farm). As the water flows through the farms, net variations in the chemical characteristics were observed: a mean reduction in the dissolved oxygen (DO) concentration between 0.7 and 2.4 mg litre(-1); mean increases between 1.9 and 3.2 mg CaCO3 litre(-1) for total alkalinity, between 0.9 and 14 mg litre(-1) for BOD5, between 0.27 and 1.46 mg litre(-1) for ammonia nitrogen (NH4-N), between 0.060 and 0.579 mg litre(-1) for soluble phosphorus (PO4-P) and less than 16 mg litre(-1) for suspended solids; variations in the pH value and nitrate nitrogen concentration were not statistically significant (p<0.05). At the 500 t year(-1) fish farm it was also possible to detect net increases of total hardness (3.2 mg CaCO3 litre(-1)), electric conductivity (19 mS cm(-1)) and permanganate value (3.6 mgO2 litre(-1)). At the other farms net variations in these parameters were not significant. Net mass flow variations reported to the annual fish production are presented. The DO mass flow decreased, on average, between 255 and 549 g t(-1) of fish per day. The mean daily BOD5 increase ranged from 353 to 1510 g t(-1) of fish. The corresponding ranges for the other parameters were 105-157 g t(-1) for NH4-N, 24-62 g t(-1) for PO4-P, 348-1035 g CaCO3 t(-1) for total alkalinity and 224 x 10(6)-506 x 10(6) t(-1) for mesophilic bacteria. Daily net variations of suspended solids, total hardness, electric conductivity and permanganate value were below 1753 g t(-1), 342 g CaCO3 t(-1), 2081 mS cm t(-1) and 392 gO2 t(-1), respectively. Longitudinal concentration profiles for the most relevant parameters show the impact of the effluent discharges on the physico-chemical and bacteriological river water quality downstream from the trout farms. Analyzing the situations from a purely chemical point of view, the polluted stretches were 3, 5 and 12 km long downstream from the effluent discharges, respectively. The microbiological contamination extended over longer distances.

[ERCP/ES in the therapy of acute calculous pancreatitis]

In the medical press there are several data confirming the value of E.R.C.P. and E.E.S., in the therapeutical approach of acute lithiasic pancreatitis (A.L.P.). Nowadays it is a first line endoscopic technic on the therapeutical approach in A.L.P. permitting to clean out the biliary tree of stones, eliminating the etiological factor of the disease. It's the experience of the group of E.R.C.P./E.S.E. of Hospital dos Capuchos that we will present on this paper.

[Neuropathy in Waldenstrom's macroglobulinemia]

The association of a neuropathy and a paraproteinaemia such as Waldenström's macroglobulinaemia is frequent and not fortuitous. This paper reports a slowly progressive, predominantly sensory neuropathy, occurring in a 69-year-old man, as the first sign of a Waldenström's macroglobulinaemia. A saphenous [correction of sural] nerve biopsy revealed a mixed process of primary demyelination and axonal degeneration. Accumulations of immunoglobulin M were observed in the myelin sheets and the perineurium by immunocytochemistry. Infiltrations of inflammatory blood cells and accumulations of amyloid material were absent in the peripheral nerve. The axonal loss was most prominent in central areas of the nerve fascicles. This find supports the hypothesis of an ischemic mechanism for the axonal degeneration plus secondary demyelination, associated to a direct immunological attack against myelin. The various types of peripheral nerve involvement in Waldenström's macroglobulinaemia, as well as the admitted mechanisms of nerve lesion and the therapeutic approaches to this still unclear neuropathy are briefly reviewed.

[Prefrontal syndrome as a manifestation of intracranial dural arterio-venous malformation]

The authors present a clinical case of an intracranial dural arteriovenous malformation with clinical manifestations of a prefrontal syndrome, documented with its respective diagnostic tests, including imaging studies. A number of considerations are being enlarged upon, concerning possible pathophysiological mechanisms.

[Familial peripheral neuropathy caused by susceptibility to entrapment (tomaculous neuropathy)]

The authors describe a case of hereditary neuropathy with liability to pressure palsies (entrapment), and compare it to reports from literature. The main characteristics are: autosomal dominant inheritance, recurrent mononeuropathies (ulnar, median, peroneal, brachial plexus), and specific features at nerve biopsy. The sensory nerve reveals predominantly demyelinating alterations, having the remaining myelin fibres focal thickenings, the so called tomaculous, and shows numerous subperineural structures named Renaut Bodies. The EMG findings show a slowing of the nerve conduction velocities and an increase of distal latencies.