Hypoxia-induced miR-210 modulates inflammatory response and fibrosis upon acute peripheral ischemia

Introduction

We previously demonstrated in mouse models of peripheral and heart ischemia that miR-210 is necessary and sufficient to stimulate blood perfusion recovery, as well as arteriolar and capillary density increase following ischemic damage.

Aim

To clarify the role of inflammatory cells in miR-210-induced angiogenesis.

Methods and results

In a mouse model of acute limb ischemia, miR-210 loss-of-function was obtained by administration of complementary anti-miR-210 LNA oligonucleotides (anti-210), while doxycycline-inducible miR-210 transgenic mice (Tg210) were used for gain-of-function experiments. Transcriptomic and gene ontology analysis in ischemic gastrocnemius muscles upon miR-210 blocking displayed an enrichment of categories related not only to angiogenesis, but also to inflammation, suggesting that miR-210 decrease prompted a pro-inflammatory and anti-regenerative response. Accordingly, immunofluorescence staining of ischemic muscles of anti-210 treated mice, showed an increased presence of granulocytes (Scr = 28±7, anti-210 = 108±17 cells/mm2, p<0.001), T and B lymphocytes (Scr = 32±8 SE, anti-210 = 112±19 cells/mm2, p<0.003; Scr = 45±10, anti-210 = 103±14 cells/mm2, p<0.006, respectively) and macrophages (Scr = 17±1, anti-210 = 27±4 cells/mm2; p<0.03), with a higher M1/M2 macrophage ratio (Scr = 0.6±0.1, anti-210 = 1.7±0.3; p<0.02). Conversely macrophages (WT = 17±2, Tg210 = 5±1 cells/mm2, p<0.003) and M1/M2 ratio (WT = 1.0±0.1, Tg210 = 0.3±0.1, p<0.02) were decreased in ischemic TG-210 mice. To clarify the role of inflammatory cells in miR-210-induced angiogenesis, bone-marrow (BM) transplantation experiments were performed. Tg210 mice transplanted with WT BM cells (BM-wt/R-Tg210), compared with WT mice transplanted with Tg210 BM (BM-Tg210/R-wt) showed increased blood perfusion (vascularity ratio: BM-wt/R-Tg210 = 0.8±0.1, BM-Tg210/R-wt = 0.6±0.1; p<0.01) and capillary density after ischemia (BM-wt/R-Tg210 = 497±41, BM-Tg210/R-wt = 212±32 cap./mm2; P<0.00001). Thus, miR-210 expression in the muscle and not in the BM-derived cells was crucial for miR-210-stimulated angiogenesis. Interestingly, BM-wt/R-Tg210 mice also showed increased fibrotic areas (sirius red staining: BM-wt/R-Tg210 = 12±2, BM-Tg210/R-wt = 22±3 A.U.; p<0.01), characterized by α-SMA+, vimentin+ and collagen V+ stainings. Fibrotic regions were enriched in cells double-positive for both CD206/α-SMA and CD45/α-SMA, as well as in phospho-Smad3+ cells, suggesting the activation of the TGFβ pathway. In vitro experiments showed higher expression of α-SMA and collagens in TG-210 BM-derived macrophages compared to WT, both in the presence and in the absence of TGFβ (α-SMA: w/o TGFβ 2.3±1.4 fold increase p<0.004; TGFβ+ 11.3±2 fold increase p<0.003).

Conclusions

Collectively, these data show that a miR-210 enriched milieu was sufficient to improve angiogenesis after ischemia. Moreover, a context-dependent regulation by miR-210 of the inflammatory response and of fibrosis were identified.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Italian Ministry of health: Ricerca Corrente and 5X1000

Significantly Improved Survival Time in Pigs with Complete Liver Ischemia Treated with a Novel Bioartificial Liver

Aim of the study was to evaluate treatment efficacy and safety of a scaled-up version of our porcine hepatocytes based BAL system in pigs with complete liver ischemia (LIS).

Thirty-one pigs underwent total devascularization of the liver (LIS) by termino-lateral porta-caval shunts and sutures around the bile duct, the common hepatic and gastroduodenal arteries and their accessory branches. The hepato-duodenal ligament was completely transected. Four experimental groups were studied: the first control group (LIS Control, n = 10) received glucose infusion only, the second control group (LIS Plasmapheresis, n = 8) was connected to a centrifugal plasma-separator with a bottle representing the bioreactor volume, the third control group (LIS Empty-BAL, n = 5) received BAL treatment without cells, and the treated group (LIS Cell-BAL, n = 8) was connected for a maximum period of 24 hours to our scaled-up BAL seeded with around 14 billion viable primary porcine hepatocytes.

BAL treatment significantly prolonged life in large animals (-35 kg) with complete LIS (Controls, mean ± SEM: 33.1 ± 3 h, Cell-BAL: 51.1 ± 3.4 h; p = 0.001; longest survivor 63 h). In addition, blood ammonia and total bilirubin levels decreased significantly, indicating metabolic activity of porcine hepatocytes in the bioreactor. No significant differences were noticed among the three control groups, indicating that there was no device effect and that the plasmapheresis procedure was well tolerated. No important adverse effectes were observed.

Hypoxia determines survival outcomes of bacterial infection through HIF-1alpha dependent re-programming of leukocyte metabolism

Hypoxia and bacterial infection frequently co-exist, in both acute and chronic clinical settings, and typically result in adverse clinical outcomes. To ameliorate this morbidity, we investigated the interaction between hypoxia and the host response. In the context of acute hypoxia, both S. aureus and S. pneumoniae infections rapidly induced progressive neutrophil mediated morbidity and mortality, with associated hypothermia and cardiovascular compromise. Preconditioning animals through longer exposures to hypoxia, prior to infection, prevented these pathophysiological responses and profoundly dampened the transcriptome of circulating leukocytes. Specifically, perturbation of HIF pathway and glycolysis genes by hypoxic preconditioning was associated with reduced leukocyte glucose utilisation, resulting in systemic rescue from a global negative energy state and myocardial protection. Thus we demonstrate that hypoxia preconditions the innate immune response and determines survival outcomes following bacterial infection through suppression of HIF-1α and neutrophil metabolism. The therapeutic implications of this work are that in the context of systemic or tissue hypoxia therapies that target the host response could improve infection associated morbidity and mortality.

Preclinical and clinical evaluation of MET functions in cancer cells and in the tumor stroma

A lot of attention has been dedicated to investigate the role of the tyrosine kinase receptor MET in tumors. The acquired notion that cancer cells from different histological origin strictly rely on the engagement of this specific oncogene for their growth and survival has certainly justified the development and the use of MET-targeted therapies in the clinic. However, the function and involvement of this pathway in the stroma (that often constitutes >50% of the global cellularity of the tumor) may offer the opportunity to conceive new patient stratification criteria, rational drug design and guided trials of new combination treatments. In this review, we will summarize and discuss the role of MET in cancer cells but especially in different stromal compartments, in light of the results showed by past and recent preclinical and clinical trials with anti-MET drugs.

Tumor stroma: a complexity dictated by the hypoxic tumor microenvironment

A lot of effort has been done to study how cancer cells react to low-oxygen tension, a condition known as hypoxia. Indeed, abnormal and dysfunctional blood vessels in the tumor are incapable to restore oxygenation, therefore perpetuating hypoxia, which, in turn, will fuel tumor progression, metastasis and resistance to antitumor therapies. Nevertheless, how stromal components including blood and lymphatic endothelial cells, pericytes and fibroblasts, as well as hematopoietic cells, respond to low-oxygen tension in comparison with their normoxic counterparts has been a matter of investigation in the last few years only and, to date, this field of research remains poorly understood. In general, opposing phenotypes can arise from the same stromal component when embedded in different tumor microenvironments, and, vice versa, different stromal components can have opposite reaction to the same tumor microenvironment. In this article, we will discuss the emerging link between tumor stroma and hypoxia, and how this complexity is translated at the molecular level.

Sema3E-Plexin D1 signaling drives human cancer cell invasiveness and metastatic spreading in mice

Semaphorin 3E (Sema3E) is a secreted molecule implicated in axonal path finding and inhibition of developmental and postischemic angiogenesis. Sema3E is also highly expressed in metastatic cancer cells, but its mechanistic role in tumor progression was not understood. Here we show that expression of Sema3E and its receptor Plexin D1 correlates with the metastatic progression of human tumors. Consistent with the clinical data, knocking down endogenous expression of either Sema3E or Plexin D1 in human metastatic carcinoma cells hampered their metastatic potential when injected into mice, while tumor growth was not markedly affected. Conversely, overexpression of exogenous Sema3E in cancer cells increased their invasiveness, transendothelial migration, and metastatic spreading, although it inhibited tumor vessel formation, resulting in reduced tumor growth in mice. The proinvasive and metastatic activity of Sema3E in tumor cells was dependent on transactivation of the Plexin D1-associated ErbB2/Neu oncogenic kinase. In sum, Sema3E-Plexin D1 signaling in cancer cells is crucially implicated in their metastatic behavior and may therefore be a promising target for strategies aimed at blocking tumor metastasis.

Novel alternatives for anti-angiogenetic therapy and therapeutic angiogenesis

Anti-angiogenic therapy and therapeutic angiogenesis have been proposed as opposite strategy for the treatment of cancer and ischemic diseases, respectively. However, both approaches do not provide long term solutions of these pathological conditions and have failed in clinical trials. Therefore, novel strategies are needed. In the current work we describe: 1) how vessels sense and re-adapt oxygen supply and, hence, perfusion in case of oxygen shortage, therefore identifying PHD2 oxygen sensor as a novel target to normalize the tumor vasculature, reduce cancer hypoxia and prevent cancer cell extravasations and dissemination; 2) anti-P1GF as a efficient and safe tool in cancer therapy that does not prune excessively pathological vessels and does not affect the normal vasculature; 3) hypoxia tolerance via inhibition of the oxygen sensor PHD1 as alternative strategy to therapeutic angiogenesis. Altogether, our findings provide new alternatives in the treatment of ischemic disorders and cancer, largely unmet medical problems to date.

The use of non-invasive ventilation in the treatment of acute cardiogenic pulmonary edema

The patient with acute heart failure may present with acute cardiogenic pulmonary edema (ACPE), a condition accompanied by severe respiratory distress, with crackles over the lung and orthopnea, and an O2 saturation usually < 90% on room air, prior to treatment. Non-invasive ventilation is the delivery of assisted ventilation without the need for endotracheal intubation and an invasive artificial airway. Two techniques are used for ventilatory support: continuous positive airway pressure (CPAP) and non-invasive positive-pressure ventilation (NPPV). There is a strong consensus that one of these two techniques should be used before endotracheal intubation and mechanical ventilation because non-invasive techniques dramatically reduce the need for mechanical ventilation via endotracheal intubation and its complications. The aim of this review is to evaluate and resume the evidence for the use of non-invasive positive pressure ventilation in the treatment of acute cardiogenic pulmonary edema according recent literature in order to guide physicians in using CPAP and NPPV in patients affected by ACPE in clinical practice. Recent literature showed that CPAP and NPPV both significantly decrease the need for endotracheal intubation, and CPAP significantly decreases mortality when compared to standard medical treatment. These techniques resulted safe and there is no evidence of increased risk of acute myocardial infarction (AMI) with either of them. Although both CPAP and NPPV present similar efficacy, CPAP has been shown to be cheaper and easier to implement in clinical practice and it could be considered the preferred intervention in patients with ACPE especially in the Emergency Department setting.

Quality in emergency departments: a study on 3,285,440 admissions

INTRODUCTION

A multi-centre study has been conducted, during 2005, by means of a questionnaire posted on the Italian Society of Emergency Medicine (SIMEU) web page. Our intention was to carry out an organisational and functional analysis of Italian Emergency Departments (ED) in order to pick out some macro-indicators of the activities performed. Participation was good, in that 69 ED (3,285,440 admissions to emergency services) responded to the questionnaire.

METHODS

The study was based on 18 questions: 3 regarding the personnel of the ED, 2 regarding organisational and functional aspects, 5 on the activity of the ED, 7 on triage and 1 on the assessment of the quality perceived by the users of the ED.

RESULTS AND CONCLUSION

The replies revealed that 91.30% of the ED were equipped with data-processing software, which, in 96.83% of cases, tracked the entire itinerary of the patient. About 48,000 patients/year used the ED: 76.72% were discharged and 18.31% were hospitalised. Observation Units were active in 81.16% of the ED examined. Triage programmes were in place in 92.75% of ED: in 75.81% of these, triage was performed throughout the entire itinerary of the patient; in 16.13% it was performed only symptom-based, and in 8.06% only on-call. Of the patients arriving at the ED, 24.19% were assigned a non-urgent triage code, 60.01% a urgent code, 14.30% a emergent code and 1.49% a life-threatening code. Waiting times were: 52.39 min for non-urgent patients, 40.26 min for urgent, 12.08 for emergent, and 1.19 for life-threatening patients.

Amiodarone-induced thyroid dysfunction in clinical practice

Amiodarone is a potent class III anti-arrhythmic drug used in clinical practice for the prophylaxis and treatment of many cardiac rhythm disturbances, ranging from paroxismal atrial fibrillation to life threatening ventricular tachyarrhythmias. Amiodarone often causes changes in thyroid function tests mainly related to the inhibition of 5'-deiodinase activity resulting in a decrease in the generation of T3 from T4 with a consequent increase in rT3 production and a decrease in its clearance. In a group of amiodarone-treated patients there is overt thyroid dysfunction, either amiodarone-induced thyrotoxicosis (AIT) or amiodarone-induced hypothyroidism (AIH). AIT is primarily related to excess iodine-induced thyroid hormone synthesis in an abnormal thyroid gland (type I AIT) or to amiodarone-related destructive thyroiditis (type II AIT). The pathogenesis of AIH is related to a failure to escape from the acute Wolff-Chaikoff effect due to defects in thyroid hormonogenesis, or, in patients with positive thyroid autoantibody test, to concomitant Hashimoto's thyroiditis. Both AIT and AIH may develop either in apparently normal thyroid glands or in glands with preexisting, clinically silent abnormalities. AIT is more common in iodine-deficient regions of the world, whereas AIH is usually seen in iodine-sufficient areas. In contrast to AIH, AIT is a difficult condition to diagnose and treat, and discontinuation of amiodarone is usually recommended. In this review we analyse, according to data from current literature, the alterations in thyroid laboratory tests seen in euthyroid patients under treatment with amiodarone and the epidemiology and treatment options available of amiodarone-induced thyroid dysfunctions (AIT and AIH).

Approach to respiratory failure in emergency department

OBJECTIVES AND BACKGROUND

The goal of this review is to provide update recommendations that can be used by emergency physicians who provide primary cares to patients with Acute Respiratory Failure (ARF), from the admission to an emergency department through the first 24 to 48 hours of hospitalization. This work wants to address the diagnosis and emergency medical care of ARF and the management of medical complications.

STATE OF THE ART

A lot of statement has been developed for the early management and treatment of ARF; moreover, over the last fifteen years, we have assisted to the rise of a new technique of ventilation, in the Emergency Department: Non Invasive Ventilation. This kind of ventilation was firsthy applied in intensive Care and in Respiratory Care Unit. Randomized controlled clinical trials have showed its usefulness in the early treatment of several forms of ARF, together with medical therapy.

Review of dilated cardiomyopathies. Dilated cardiomyopathies and altered prothrombotic state: a point of view of the literature

Heart failure is an enormously important clinical problem that, if not faced, may overwhelm health care resources. Primary and secondary cardiomyopathies cause the majority of cases of clinical heart failure, which is thus better approached from the utility point of view of myocardial failure. Furthermore, the risk of thromboembolic complications presenting in such disease may be higher than in ischemic cardiomyopathy. Intracardiac thrombi and mural endocardial plaques (from the organization of thrombi) are present at necropsy in more than 50% of patients with dilated cardiomyopathy (DCM). Several studies have shown that systemic and pulmonary emboli are more frequent in patients with ventricular thrombi or plaques. Dilated cardiomyopathy has been associated with left ventricular thrombosis which leads to substantial morbidity and mortality as a site for peripheral emboli. There are some studies on patients with dilated cardiomyopathy showing altered hemostasis and platelet behavior despite sinus rhythm. Platelet activation, thrombin activation and fibrinolytic activity are increased in patients with DCM compared to normal subjects. However, these markers reflecting coagulation activation in patients with left ventricle thrombus are comparable to those in patients without thrombus in the left ventricle. The pathophysiology and clinical issues concerning the susceptibility to develop left ventricular (LV) thrombosis and its complications like cerebrovascular disease in patients with DCM are summarized and the most recent articles present in the medical literature are reviewed.

Heart failure and therapy

The clinical syndrome of heart failure is the final outcome of a number of diseases affecting the heart. Several studies undertaken over the past decade, have led to a significant change in the therapies available and a growing understanding of the physiopathological mechanisms. Increasingly, the current treatment of heart failure, is not just symptomatic but also etiologic and physiopathologic. In this paper we will try to furnish guidelines, as practical as possible, for the treatment of this syndrome, addressing the physiopathologic and experimental principles which underlie it. The present suggestions are based on the updated literature review, they conform to the latest guidelines of the European Society of Cardiology and are in agreement with the classification in grades, proposed by the American Heart Association and the American College of Cardiology.

Brain natriuretic peptide and acute coronary syndrome

The natriuretic peptide system (atrial natriuretic peptide, brain natriuretic peptide, BNP, and C natriuretic peptide) is an important marker of cardiac failure. These peptides are synthesized in atrial or ventricular myocytes in response to wall tension. In several studies the correlation between high BNP levels and mortality, in patients with acute coronary syndrome and heart failure, has been demonstrated. On the other hand, plasma levels of BNP could be considered as independent predictors of mortality in patients with heart failure. BNP could be used, for instance, as an early diagnostic marker for the differential diagnosis between cardiogenic and non cardiogenic dyspnea. In the Emergency Department its use will be important in the diagnosis of thoracic pain origin since it may help in the diagnostic and therapeutic course of this patient and to define the modality of hospitalization. Moreover, it can be used as a marker of heart failure severity and as an important negative prognostic factor. Some studies have confirmed that plasma BNP reflects the degree of left ventricular dysfunction and the prognostic significance after acute myocardial infarction and chronic heart failure.

How to use the C-reactive protein in cardiac disease?

Inflammation is an important contributor to atherothrombosis. The C-reactive protein (CRP) is not only an excellent biomarker of inflammation, but it is also a direct participant in atherogenesis. CRP consistently predicts new coronary events, including myocardial infarction and death, in patients with ischemic heart disease. The predictive value of CRP is, in the majority of the studies, independent of and additive to that of the troponins and its levels can be modulated by statins. Prospective observational studies show that moderately elevated levels of CRP are associated with an adverse cardiovascular prognosis among healthy individuals. The availability of high sensibility assays for CRP should provide a valuable tool for identifying patients at risk of cardiovascular events in primary prevention in conjunction with lowering LDL cholesterol and may also have utility in the treatment of acute coronary syndromes with percutaneous coronary intervention (PCI) therapy. High CRP levels, associated with a higher risk, should suggest a more aggressive medical therapy in the long term and also an aggressive and invasive therapy in the short term, including the use of GP IIb/IIIa inhibitors, high doses of statins, and when a PCI is necessary, provisional stenting. Finally, CRP will provide a readily accessible marker for further testing of the inflammatory hypothesis in atherosclerosis.

[Usefulness of magnetic resonance imaging for the diagnosis of acute myocarditis. A case of acute myocarditis as myocardial infarction-like]

According to the Dallas criteria, myocarditis is defined histologically as an inflammatory process involving the myocardium with an inflammatory infiltrate and myocyte necrosis or damage. Clinically, myocarditis is an insidious disease that is usually asymptomatic and commonly underdiagnosed. Infact, the symptoms are often non-specific and the majority of cases recover fully with no sequelae. At present, endomyocardial biopsy remains the gold standard for the diagnosis of myocarditis, despite its limited sensitivity and specificity. However, the lack of an association between biopsy evidence of myocarditis and the presence of autoantibodies in patients with clinical signs of myocarditis, the paucity of the positive biopsy findings in large cohorts of patients with suspected myocarditis, the potential discordance between clinical and histologic features and the inherent limitation of histologic diagnosis, suggest that the diagnosis shouldn't be based on histologic examination alone. The magnetic resonance imaging (MRI) with gadolinium can be useful to visualize the localization, activity and extent of inflammation and may be a powerful noninvasive diagnostic tool in acute myocarditis. Infact, MRI achieves a 100% sensitivity and a 90% specificity. We report the case of a 31-year-old male patient with an acute myocarditis with electrocardiographic manifestations like to acute myocardial infarction, whose diagnosis was based on the clinical signs and on the characteristic pattern of the MRI with paramagnetic contrast. The MRI with gadolinium is suggested as noninvasive study to support the diagnosis of acute myocarditis in the correct clinical setting.

[Humoral and cellular inflammatory mediators in acute lung injury: friends or enemies? ]

Diffuse lung injury (DLI) is characterised by damage to the alveolar and endothelial epithelium that leads to acute respiratory insufficiency. From the histological point of view, this pathological process proceeds through an initial exudative phase which is followed by the organisation of the inflammatory infiltrate up to the deposit of collagen and fibrin which seriously compromises gaseous exchanges. The clinical expression typical of this pathology consists of Acute Lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS) characterised by hypoxemia resistant to oxygen therapy, tachypnea and the presence of bilateral infiltrates on conventional X-ray of the thorax. Although the etiology is multifactorial, the pathogenesis depends on the uncontrolled activation of the inflammation system in its humoral and cellular components. The present paper examines the principal studies regarding the most important mediators. From an analysis of the literature it emerges that some cytokines (IL-1betha, IL-6, IL-6ra) and cellular mediators (NF-kB, sFasL) are responsible for the epithelial damage by way of complex mechanisms that include apoptosis. Studies carried out up to the present have not however evidenced any independent pathway decisive for pathogenesis. This shows that inflammation is in effect a multiform process that originates precisely as a result of the mutual interaction of the factors implicated in it. The humoral and cell mediators can, however, be used as clinical indicators correlatable with the clinical and physiopathological outcome.

Whole-genome organization and functional properties of miniature DNA insertion sequences conserved in pathogenic Neisseriae

The chromosome of pathogenic Neisseriae is peppered by members of an abundant family of small DNA sequences known as Correia elements. These DNA repeats, that we call nemis (for neisseria miniature insertion sequences) can be sorted into two major size classes. Both unit-length (154-158 bp) and internally rearranged (104-108 bp) elements feature long terminal inverted repeats (TIRs), and can potentially fold into robust stem-loop structures. Nemis are (or have been) mobile DNA sequences which generate a specific 2-bp target site duplication upon insertion, and strictly recall RUP, a repeated DNA element found in Streptococcus pneumoniae. The subfamilies of 26L/26R, 26L/27R, 27L/27R and 27L/26R elements, found by wide-genome computer surveys in both the Neisseria meningitidis and the Neisseria gonorrhoeae genomes, originate from the combination of TIRs which vary in length (26-27 bp) as in sequence content (L and R types). In both species, the predominant subfamily is made by the 26L/26R elements. The number of nemis is comparable in the N. meningitidis Z2491 (A serogroup) and the MC58 (B serogroup) strains, but is sharply reduced in the N. gonorrhoeae strain F1090. Consequently, several genes which are conserved in the two pathogens are flanked by nemis DNA in the meningococcus genome only. More than 2/3 of nemis are interspersed with single-copy DNA, and are found at close distance from cellular genes. Both primer extension and RNase protection data lend support to the notion that nemis are cotranscribed with cellular genes and subsequently processed, at either one or both TIRs, by a specific endoribonuclease, which plausibly corresponds to RNase III.

Nitric oxide. A general review about the different roles of this innocent radical

Nitric oxide, a short half-life radical, is highly reactive, and it is involved in many biological processes, such as vascular homeostasis, neurotransmission, and inflammation, defined as a sequence of events which can be simplified as follows: vasodilatation, alteration of vascular permeability, emigration of leucocytes from vessels, migration of leucocytes into the sites of tissutal damages or inflammation, activation of leucocyte mechanisms. This review has a double purpose: 1) to provide a comprehensive table of cell types that produce NO, together with the effects of agents used to study iNOS regulation; 2) to investigate the role of NO in different human systems. The different relations between NO and cytokines, the heart, infectious diseases, inflammatory diseases, brain cells and, lastly, gastrointestinal diseases are examined.

[A clinical case of hepatic psittacosis with ultrasonography anomalies of the liver]

Psittacosis marked by liver and spleen involvement and minimal pericarditis was observed in an 18-year-old patient hospitalized for fever of 1 month duration. Liver tests revealed cholestasis. Ultrasonography revealed multiple nodular formations in the liver and spleen, images confirmed on computed tomography. Liver biopsy showed granulomatous with hyperplasia of the Kupffer cells surrounded by healthy tissue. The diagnosis was confirmed by complement fixation. Treatment with tetracycline led to rapid remission of the fever and normalization of the liver tests and hepatic images.

[Nitro derivatives: considerations on their antiplatelet activity]

The antischemic effect of nitrates is known and well accepted since more than 100 years, but recently many and interesting studies about antiaggregant property of such drugs have been reported. This action would be lied to increased synthesis of GMPc. The antiaggregant property pf nitrates may be leave open the problem to include the nitrates between the drugs able to influence the prognosis of myocardial infarction both in acute and chronic phase, such as betablockers, ASA and thrombolytics.

Significantly improved survival time in pigs with complete liver ischemia treated with a novel bioartificial liver

Aim of the study was to evaluate treatment efficacy and safety of a scaled-up version of our porcine hepatocytes based BAL system in pigs with complete liver ischemia (LIS). Thirty-one pigs underwent total devascularization of the liver (LIS) by termino-lateral porta-caval shunts and sutures around the bile duct, the common hepatic and gastroduodenal arteries and their accessory branches. The hepato-duodenal ligament was completely transected. Four experimental groups were studied: the first control group (LIS Control, n = 10) received glucose infusion only, the second control group (LIS Plasmapheresis, n = 8) was connected to a centrifugal plasma-separator with a bottle representing the bioreactor volume, the third control group (LIS Empty-BAL, n = 5) received BAL treatment without cells, and the treated group (LIS Cell-BAL, n = 8) was connected for a maximum period of 24 hours to our scaled-up BAL seeded with around 14 billion viable primary porcine hepatocytes. BAL treatment significantly prolonged life in large animals (approximately 35 kg) with complete LIS (Controls, mean +/- SEM: 33.1 +/- 3 h, Cell-BAL: 51.1 +/- 3.4 h; p = 0.001; longest survivor 63 h). In addition, blood ammonia and total bilirubin levels decreased significantly, indicating metabolic activity of porcine hepatocytes in the bioreactor. No significant differences were noticed among the three control groups, indicating that there was no device effect and that the plasmapheresis procedure was well tolerated. No important adverse effects were observed.

[Dynamics of ascitic fluid in decompensated cirrhosis]

The ascitic fluid in decompensated liver cirrhosis constitutes a continuously circulating pool which carries on sustained water exchanges with plasma and extracellular fluids through the whole peritoneal membrane. The actual ascites volume results therefore from the steady-state between the formation and reabsorption transperitoneal water flows. The ascitic reabsorption concerns both the "iso-osmotic" (i.e. the portion bound to the ascitic proteins and solutes) and the "free-water" (i.e. the amount exceeding the osmotic bounding ability of the peritoneal solutes) fractions of total ascitic water. By means of a simple dilution test, it is possible an in vivo estimation of both the ascites volume and the rate of transperitoneal free-water reabsorption, which is the actual free-water peritoneal clearance (CPAL) and an evaluation of the total intra-abdominal pressure (PIA). PIA results from the sum of the ascitic hydrostatic pressure, and the tension of the abdominal wall. Diuretic administration is able to significantly reduce CPAL, inducing a negative sodium balance and thus leading to a readjustment of ascites steady-state. This fact may cause reductions of ascites volume and PIA only after several days of diuretic treatment. An acute diuretic treatment by itself, even if intensive and resulting in a rapid diuresis and a significant modification of CPAL, does not appear able to determine rapid and detectable modifications of PIA. CPAL has an intrinsic prognostic value in patients with decompensated cirrhosis, since the cumulative mortality was reported to be significantly higher in the patients with lower CPAL levels. The peritoneal clearance ability may be regarded as a compensatory mechanisms of portal hypertension, and its estimate may be a reliable index of patient's aptitude to a lower hydro-retentive trend, which is in turn correlated to a greater cirrhosis severity and a worse prognosis.

Ascites free-water dynamics in decompensated cirrhosis: effects of an acute Hemaccel infusion

BACKGROUND

Plasma-expanders (PE) are commonly employed to reduce the hemodynamic effects of large-volume paracentesis in patients with decompensated cirrhosis. The aim of this paper is to investigate the effects of PE acute administration on ascites dynamics in cirrhotic patients.

METHODS

Wash-out intraabdominal pressure (IAP), ascites volume and free-water peritoneal clearance (FWPC) were evaluated in six decompensated cirrhosis by means of a methylene-blue (MB) dilution method. The method is based on the compartmental analysis of MB peritoneal clearance and has been validated by previous deuterium oxide studies. Immediately after the MB dilution test, a rapid Hemaccel i.v. infusion (500 ml 3.5% in 15 min) was perform-ed in all subjects, thereafter carrying out a second MB test. The obtained results were analyzed by two-way variance analysis.

RESULTS

IAP and ascites volume values were not appreciably modified by the PE treatment. Following the Hemaccel infusion, only a fair reduction of FWPC values (from 88.33+/-7.78 to 76.98+/-8.09 ml/min) was observed.

CONCLUSIONS

The results obtained indicate that, at least at the employed doses, Hemaccel acute administration has a low impact on the ascites dynamics in decompensated cirrhotics. These data cannot therefore support the hypothesis of a therapeutic use of PE in ascitic patients, but to avoid excessive plasma volume reductions in association with a large volume paracentesis.

[The importance of follow-up of colorectal polyps]

In this paper, we have considered the indications for coloscopy for the screening of colon polyposis. On the basis of its sensitivity in detection and follow-up of colo-rectal cancer, we tried to determine the exact procedure to be followed subsequent to the discovery and ablation of a polyp. We have outlined the following parameters to be observed during the period of follow-up: dimension, number, histologic features of the polyp, age, general conditions and familiarity of the patient for colorectal cancer.

[Physiopathologic aspects of non-ulcerous dyspepsia. Considerations of a new diagnostic method]

The above study is an analysis of different dyspeptic syndromes outlining their pathophysiology and clinical features. On this basis, the authors suggest a diagnostic strategy, stressing the importance of certain elements such as age at onset, duration and variability of symptoms. This allows to evaluate the indications for endoscopy or biopsy, or to decide that it is sufficient to continue observation while reassuring the patient that the dyspeptic condition is benign.

[Studies on the cardiovascular response to hypoxia]

Fifty-eight adults, nearly all male, aged between 35 and 50, with slight bronchiopneumopathy in a state of functional compensation, were subjected to hypoxia by rerespiration. Heart rate and oxyhaemoglobin saturation were observed. In nearly all cases, hypoxia caused an increase in heart rate that varied considerably from subject to subject, but seemed more marked between the 1st and 2nd minute after start of the trial. Normalization of heart rate, similarly very variable, reflected the increase phase and was complete in periode varying between 30 and 210 seconds. It may be supposed that as regards heart rate the wide variety of responses to the same stimulus is due to individual states of equilibrium of a predominantly vegetative nature. There was no relation between duration of the hypoxia trial, extent of desaturation and time of resaturation in air because the rate of haemoglobin desaturation and resaturation varied from case to case.