Agonistic anti-human Fas monoclonal antibody induces fibroblast-like synoviocyte apoptosis in haemophilic arthropathy: potential therapeutic implications.

Haemophilic arthropathy (HA) is characterized by chronic proliferative synovitis leading to cartilage destruction and shares some pathological features with rheumatoid arthritis (RA). Apoptosis has been implicated in RA pathogenesis, and an agonistic anti-Fas monoclonal antibody (mAb) was found to induce RA fibroblast-like synoviocyte (FLS) apoptosis and suppress synovial hyperplasia in animal models of RA. The aim of this study was to evaluate the effect of anti-Fas mAb on HA-FLS. FLS were isolated from knee synovial biopsies from six HA patients, six RA patients and six healthy subjects. The expression of Fas in synovial biopsies was investigated by immunohistochemistry. FLS were stimulated with anti-Fas mAb at different concentrations, alone or in combination with tumour necrosis factor-α (TNF-α) and basic fibroblast growth factor (bFGF). Fas expression in FLS was assessed by Western blot. Cell viability was studied with the WST-1 assay. Active caspase-3 levels were measured using ELISA and Western blot. A strong Fas-immunoreactivity was observed in different cells of HA synovium, including FLS, inflammatory cells and endothelial cells. Fas antigen was constitutively overexpressed in cultured HA-FLS. Anti-Fas mAb had a significant cytotoxicity on HA-FLS in a dose-dependent manner, either alone or in combination with TNF-α and bFGF. These cytotoxic effects were due to the ability of anti-Fas to induce HA-FLS apoptosis, as shown by the increased active caspase-3 levels. Anti-Fas mAb exhibited a more pronounced pro-apoptotic effect on HA-FLS than RA-FLS. Fas antigen is highly expressed on HA-FLS and its stimulation by anti-Fas mAb may be an effective strategy to induce HA-FLS apoptosis.

Severe fibrotic changes and altered expression of angiogenic factors in maternal scleroderma: placental findings.

OBJECTIVE: Pregnant women with systemic sclerosis (SSc; scleroderma) have an increased risk of premature delivery and small full-term infants. During placental development, angiogenesis and vascular remodelling are essential for a successful pregnancy outcome. An analysis was made of the pathological changes and expression of angiogenic factors in SSc placentas. METHODS: Placenta biopsies were obtained from three patients with SSc and four healthy uncomplicated pregnancies after delivery at 34-38 weeks of gestation. The sections were stained with Masson's trichrome and phosphotungstic-acid-haematoxylin and immunostained for connective tissue growth factor (CTGF), alpha-smooth muscle actin (alpha-SMA), vascular endothelial growth factor (VEGF), placenta growth factor (PlGF) and receptors VEGFR-1 and VEGFR-2. RESULTS: The pathological findings were signs of decidual vasculopathy, increased syncytiotrophoblast knotting, placental infarcts and villous hypoplasia. Severe and diffuse perivascular and stromal fibrosis of decidua and chorionic villi, and extensive deposition of fibrinoid material around decidual vessels and in intervillous spaces were observed. Strong CTGF expression in the vessel wall, decidual cells and fibroblasts and alpha-SMA+ myofibroblasts were found. VEGF and VEGFR-2 expression was stronger in SSc than in healthy placentas, while VEGFR-1 expression was similar to controls. PlGF immunopositivity was weaker in SSc. CONCLUSION: In SSc placentas, severe fibrosis and abnormal vascular remodelling were detected. This may result in reduced blood flow leading to deep sufferance of maternal placenta and possible premature delivery.

The -670G>A polymorphism in the FAS gene promoter region influences the susceptibility to systemic sclerosis.

OBJECTIVE: To evaluate the role of the single-nucleotide polymorphism (SNP) at position -670 in the FAS gene promoter (FAS-670G>A) in influencing the susceptibility, clinical features and severity of systemic sclerosis (SSc). METHODS: 350 white Italian SSc patients (259 with limited cutaneous SSc (lcSSc) and 91 with diffuse cutaneous SSc (dcSSc)) and 232 healthy individuals were studied. Patients were assessed for the presence of autoantibodies (anticentromere, anti-topoisomerase I (anti-Scl-70) antibodies), interstitial lung disease (ILD), pulmonary arterial hypertension and scleroderma renal crisis. FAS-670G>A SNP was genotyped by PCR restriction fragment length polymorphism assay. Serum levels of soluble FAS (sFAS) were analysed by ELISA. RESULTS: A significant difference in FAS-670 genotype distribution was observed between SSc patients and healthy individuals (p = 0.001). The frequency of the FAS-670A allele was significantly greater in SSc than in controls (p = 0.001). No significant difference in genotype distribution and allele frequencies was observed between lcSSc and dcSSc, although a greater frequency of the FAS-670A allele was found in dcSSc. The FAS-670AA genotype significantly influenced the predisposition to SSc (OR 1.97, 95% CI 1.35 to 2.88, p = 0.001) and to both lcSSc (OR 1.84, 95% CI 1.23 to 2.75, p = 0.003) and dcSSc (OR 2.37, 95% CI 1.41 to 3.99, p = 0.001). FAS-670A allele frequency was greater, although not significantly, in anti-Scl-70 antibody-positive dcSSc and ILD dcSSc. sFAS was significantly higher in patients and controls carrying the FAS-670AA genotype compared with those carrying the FAS-670GG genotype (p = 0.003 in SSc, p = 0.004 in controls). CONCLUSION: The FAS-670A allele is significantly associated with susceptibility to SSc, suggesting a role for a genetic control of apoptosis in the pathogenesis of the disease.

Association between a stromal cell-derived factor 1 (SDF-1/CXCL12) gene polymorphism and microvascular disease in systemic sclerosis.

OBJECTIVE: To investigate the possible implication of SDF1-3' polymorphism in systemic sclerosis (SSc) susceptibility or clinical phenotype, or both. METHODS: 150 patients with SSc and 150 controls were enrolled. Skin involvement, autoantibodies, interstitial lung disease, pulmonary arterial hypertension (PAH), scleroderma renal crisis, past and/or current skin ulcers were assessed. Genotyping was performed by PCR-RFLP. RESULTS: Genotype distribution and allele frequency were similar in SSc and controls. SDF1-3'A allele and SDF1-3'GA/AA genotype frequencies were significantly higher in SSc-PAH than in SSc-non-PAH (33.3% vs 18.3%, p = 0.01) and in SSc with skin ulcers than in SSc without ulcers (27.3% vs 16.9%, p = 0.03). The SDF1-3'A allele influenced the predisposition to SSc-related PAH (OR = 2.52, 95% CI 1.11 to 5.69, p = 0.02) and skin ulcers (OR = 2.31, 95% CI 1.18 to 4.52, p = 0.01). After adjustment for age and gender, the SDF1-3'A allele remained a susceptibility factor for the SSc-related vascular manifestations (PAH: OR = 2.37, 95% CI 1.04 to 5.42, p = 0.04; ulcers: OR = 2.33, 95% CI 1.78 to 4.62, p = 0.01). CONCLUSION: The SDF1-3'A allele is significantly associated with microvascular involvement in SSc.

Induced sputum in systemic sclerosis interstitial lung disease: comparison to healthy controls and bronchoalveolar lavage.

BACKGROUND: Induced sputum (IS) is a noninvasive tool, which can be used to collect cellular and soluble materials from lung airways. OBJECTIVE: To evaluate if IS may be a useful and safe tool for the detection of airway inflammation in patients with interstitial lung disease (ILD) in systemic sclerosis (SSc). METHODS: Sixty-eight patients with SSc and ILD as well as 18 healthy individuals (controls) were selected and submitted to IS examination. In 34 of 68 patients with SSc, bronchoalveolar lavage (BAL) was also performed. Safety of IS was assessed by comparison of forced expiratory volume in the first second (FEV(1)), FEV(1)/forced vital capacity ratio and peak expiratory flow before and after the IS procedure. Cell composition in samples collected by BAL and IS was correlated, and IS total and differential cell count in SSc patients and controls were compared. RESULTS: The total number of cells was significantly higher in IS samples of SSc patients compared to those of healthy controls. Mean percentage of neutrophils was also higher in SSc patients (41.79 +/- 23.89 vs. 27.37 +/- 17.90), as well as lymphocytes (17.42 +/- 19.70 vs. 3.13 +/- 2.28) and eosinophils (2.35 +/- 4.43 vs. 0.41 +/- 0.46). On the other hand, mean percentage of macrophages was higher in healthy individuals (69.10 +/- 19.15 vs. 36.96 +/- 20.68). In fluid recovered by BAL, the most frequent cells were macrophages (67.89% +/- 17.26), while neutrophils (14.77 +/- 17.18%) and lymphocytes (15.62 +/- 13.46%) were less frequent and eosinophils (1.66 +/- 2.08%) were rare. A similar pattern of cell composition was found in IS samples (41.15 +/- 21.67% of macrophages, 39.72 +/- 23.15% of neutrophils, 15.28 +/- 19.46% of lymphocytes and 2.56 +/- 5.03% of eosinophils). Strength of correlation between BAL and IS was significant for macrophages and neutrophils. After IS procedure was performed, improvement of FEV(1) (mean value before IS was 85.09 +/- 14.44 and 88.93 +/- 16.40 after IS) and FEV(1)/forced vital capacity (mean value before IS was 98.53 +/- 12.11 and 105.22 +/- 10.78 after IS) was observed. CONCLUSION: The IS method may allow a noninvasive assessment of cell composition in airway fluid and may contribute to the better understanding of upper/medium airway inflammation in SSc. Future studies are needed to verify whether IS can replace invasive procedures for the detection and monitoring of lung inflammation in SSc.

Differential expression of tissue kallikrein in the skin of systemic sclerosis.

Systemic sclerosis (SSc) is characterised by ischemic damage, impaired angiogenesis and skin fibrosis. Tissue kallikrein (t-kallikrein) is involved through kinins in inflammation, vasorelaxation and angiogenesis. T-kallikrein is synthetised by endothelial, smooth muscle, and inflammatory cells and, in skin, also by dark cells of the sweat glands, where it is involved in sweat formation. Our aim was to analyse, by immunohistochemistry and RT-PCR, the expression of t-kallikrein in the skin of patients with different SSc subsets, limited (lSSc) and diffuse (dSSc), and phases, early and advanced. Skin biopsies were taken from 18 SSc patients and 10 controls. Immunohistochemistry was performed on paraffin sections with an antibody against human urinary t-kallikrein. For RT-PCR, cDNA from skin biopsies was amplified using primers specific for human t-kallikrein. In the control skin, dark cells of the secretory units of sweat glands showed immunopositivity for t-kallikrein as well as blood vessels. In the lSSc skin, immunoreactivity was observed only in some glands, with weak staining in the advanced phase. In early lSSc skin, immunoreactivity was observed in microvessel walls and in the inflammatory infiltrate. In dSSc skin, dark cells of the glandular fundus units, and the few remaining vessels showed scarcity (early phase) or lack (advanced phase) of immunoreactivity for t-kallikrein. RT-PCR confirmed a decrease of t-kallikrein mRNA levels from early to advanced phase in SSc subsets, reaching its lowest level in advanced dSSc. In conclusion, immunohistochemical and biomolecular results indicate that t-kallikrein is decreased in the skin of SSc patients and decreases progressively from the early to advanced phase of lSSc and dSSc. The decreased expression of t-kallikrein may be involved in the impairment of the sweating process, vessel functionality and angiogenesis.

Increased circulating levels of tissue kallikrein in systemic sclerosis correlate with microvascular involvement.

BACKGROUND: In systemic sclerosis (SSc) the lack of an angiogenic response to hypoxia may be due to inappropriate synthesis of angiogenic and angiostatic factors. Tissue kallikrein (t-kallikrein), regulating the kallikrein-kinin system and acting on the microcirculation, is a potent angiogenic agent, and kallistatin is its natural inhibitor. OBJECTIVE: To evaluate, in patients with SSc, t-kallikrein and kallistatin levels and their correlation with clinical features and measures of microvascular involvement. PATIENTS AND METHODS: Serum levels of t-kallikrein and kallistatin (ELISA) and t-kallikrein skin expression (immunohistochemistry) were studied in patients with SSc, and evaluated for subset (dSSc or lSSc), clinical and immunological features, and microvascular involvement (ulcers, telangiectasias, nailfold videocapillaroscopy). RESULTS: Circulating levels of t-kallikrein were higher in SSc than in controls (p<0.001). T-kallikrein did not differ between lSSc and dSSc, although it was higher in lSSc than in controls (p<0.001).T-kallikrein levels were higher in patients with early and active capillaroscopic pattern than in those with late pattern (p = 0.019 and 0.023). Patients with giant capillaries and capillary microhaemorrhages had higher t-kallikrein concentrations than patients with architectural derangement (p = 0.04). No differences in kallistatin levels were detected between patients with SSc and controls, or between lSSc and dSSc. In early SSc skin, the presence of t-kallikrein was found in endothelial and in perivascular inflammatory cells, while no staining in skin of advanced SSc was detected. CONCLUSION: T-kallikrein levels are increased in patients with SSc, particularly in lSSc, and are associated with early and active capillaroscopic patterns. T-kallikrein may play a part in SSc microvascular changes.

Interstitital cells of Cajal in the human stomach: distribution and relationship with enteric innervation.

Interstitial cells of Cajal (ICC) are distributed throughout the gastrointestinal muscle coat with a region-specific location, and are considered to be pace-maker and/or mediators of neurotransmission. Little is known about their shape, size, distribution and relationships with excitatory and inhibitory nerves in human stomach. With this aim, we labeled the ICC, using c-Kit immunohistochemistry, followed by a quantitative analysis to evaluate the distribution and area occupied by these cells in the circular and longitudinal muscle layers and at the myenteric plexus level in the human fundus, corpus and antrum. Furthermore, by NADPH-d histochemistry and substance P (SP) immunohistochemistry, we labeled and quantified nitric oxide (NO)-producing and SP-containing nerves and evidenced their relationships with the ICC in these three gastric regions. In the fundus, the ICC appeared as bipolar cells and in the corpus and antrum they mainly appeared as multipolar cells, with highly ramified processes. The networks formed by ICC differed in the three gastric regions. The ICC number was significantly higher and cell area smaller in the fundus compared to the corpus and antrum. The area occupied by the ICC was significantly higher at the myenteric plexus level compared with circular and longitudinal muscle layers. Everywhere, NADPH-d-positive nerves were more numerous than SP-positive ones. Both kinds of fibers were closely apposed to the ICC in the corpus and antrum. In conclusion, in the human stomach, the ICC have region-specific shape, size and distribution and in the corpus and antrum have close contact with both inhibitory and excitatory nerves. Presumably, as suggested for laboratory mammals, these differences are in relationship with the motor activities peculiar to each gastric area.

Modification of plasma glycosaminoglycans in long distance runners.

BACKGROUND: It is well documented that exercise reduces the risk of thromboembolic disease, possibly by increasing the plasma concentration of anticoagulant-antithrombotic compounds. OBJECTIVES: As plasma glycosaminoglycans (GAGs) play a role in the anticoagulant-antithrombotic potential of plasma, to examine the concentration and profile of these compounds in well trained, long distance runners and sedentary subjects. METHODS: Plasma GAGs were measured in 10 male, long distance runners and 10 sedentary counterparts before and after ergometric tests. GAGs were extracted, purified, and identified by electrophoretic and enzymatic methods, and measured as hexosamine. RESULTS: Plasma GAGs found in sedentary subjects were slow migrating heparan sulphates I and II, keratan sulphate I, and chondroitin 4-6-sulphate. Those found in trained athletes were slow migrating heparan sulphate I, chondroitin 4-6-sulphate (or keratan sulphate I), and fast migrating heparan sulphate. Total plasma concentrations of GAGs were higher in athletes than in sedentary subjects at rest. In sedentary subjects, plasma GAGs did not change after cycle ergometric exercise at 80% of their anaerobic threshold. However, the appearance of a novel band of heparan sulphate migrating faster than fast migrating heparan sulphate was observed in athletes after exercise. CONCLUSIONS: Exercise changes the amount and profile of plasma GAGs; these changes may play a role in protecting subjects who practise aerobic sports against developing cardiovascular disease.

[Peripheral nervous system in limited systemic sclerosis]. / Il sistema nervoso periferico nella sclerosi sistemica limitata.

OBJECTIVES: PNS is involved in Systemic Sclerosis (SSc) since the earliest phases. Our aim is to perform an ultrastructural study on skin PNS fibers in SSc. METHODS: Skin biopsies were taken from forearms of 8 patients affected by limited SSc (lSSc) and 3 controls and processed for transmission electron microscopy (TEM). The semithin sections (2 mm) were observed at light microscope and optical fields were chosen for ultrathin sections (1 mm) preparation and TEM examination. RESULTS: In lSSc skin, in the semithin sections, damaged areas are close to apparently spared areas. At TEM, in early lSSc patients, signs of inflammation and damaged microvessels are visible in derma. PNS fibers are no damaged. In advanced lSSc, fibrosis prevails on inflammation, and slight ultrastructural alterations of PNS fibers are evident in papillar derma. CONCLUSIONS: PNS lesions are different in severity in lSSc according to the disease duration, resulting more severe in advanced than in early phase.

Possible role of acylphosphatase, Bcl-2 and Fas/Fas-L system in the early changes of cardiac remodeling induced by volume overload.

To identify early adaptive processes of cardiac remodeling (CR) in response to volume overload, we investigated the molecular events that may link intracellular Ca(2+) homeostasis alterations and cardiomyocyte apoptosis. In swine heart subjected to aorto-cava shunt for 6, 12, 24, 48 and 96 h sarcoplasmic reticulum (SR) Ca(2+) pump activity was reduced until 48 h (-30%), but a recovery of control values was found at 96 h. The decrease in SR Ca(2+)-ATPase (SERCA2a) expression at 48 h, was more marked (-60%) and not relieved by a subsequent recovery, while phospholamban (PLB) concentration and phosphorylation were unchanged at all the considered times. Conversely, acylphosphatase activity and expression significantly increased from 48 to 96 h (+40%). Bcl-2 expression increased significantly from 6 to 24 h, but at 48 h, returned to control values. At 48 h, microscopic observations showed that overloaded myocardium underwent substantial damage and apoptotic cell death in concomitance with an enhanced Fas/Fas-L expression. At 96 h, apoptosis appeared attenuated, while Fas/Fas-L expression was still higher than control values and cardiomyocyte hypertrophy became to develop. These data suggest that in our experimental model, acylphosphatase could be involved in the recovery of SERCA2a activity, while cardiomyocyte apoptosis might be triggered by a decline in Bcl-2 expression and a concomitant activation of Fas.

Altered Cx43 expression during myocardial adaptation to acute and chronic volume overloading.

Gap-junctions are specialized regions of intercellular contacts allowing electrical impulse propagation among adjacent cardiomyocytes. Connexin43 (Cx43) is the predominant gap-junction protein in the working ventricular myocardium and its reduced expression has been extensively implicated in the genesis of conduction abnormalities and re-entry arrhythmia of chronically hypertrophied hearts. In contrast, data on the role played by this protein during cardiac remodeling and early phases of developing hypertrophy are lacking. Therefore, in the present study, we investigated this issue using an experimental model of pig left ventricle (LV) volume overloading consisting in the creation of an aorto-cava fistula. At scheduled times (6, 24, 48, 96, 168 h, and 2, 3 months after surgery) echocardiographic and haemodynamic measurements were performed and myocardial biopsies were taken for the morphological and biochemical analyses. When faced with the increased load, pig myocardium underwent an initial period (from 6 up to 48 h) of remarkable tissue remodeling consisting in the occurrence of cardiomyocyte damage and apoptosis. After that time, the tissue developed a hypertrophic response that was associated with early dynamic changes (up-regulation) in Cx43 protein expression, as demonstrated by Western blot and confocal immunofluorescence analyses. However, an initial transient increase of this protein was also found after 6 h from surgery. With the progression of LV hypertrophy (from 168 hr up to 3 months), a reduction in the myocardial Cx43 expression was, instead, observed. The increased expression of Cx43 protein during acute hypertrophic response was associated with a corresponding increase in the levels of its specific mRNA, as detected by RT-PCR. We concluded that up-regulation of Cx43 gap-junction protein could represent an immediate compensatory response to support the new working conditions in the early stages of ventricular overloading.

Biochemical changes and their relationship with morphological and functional findings in pig heart subjected to lasting volume overload: a possible role of acylphosphatase in the regulation of sarcoplasmic reticulum calcium pump.

We evaluated the changes in sarcoplasmic reticulum (SR) function and the parallel hemodynamic and morphological modifications in a heart subjected to volume overload. We also determined the levels of acylphosphatase, a cytosolic enzyme, that could play a regulatory effect on SR Ca(2+) pump by hydrolyzing the phosphorylated intermediate of this transport system. For this, swine hearts were subjected to volume overload by aorta-cava shunt for 1, 2, or 3 months. Changes in heart contractility reflected modifications of SR function, whose reduction after 1 month of overload was followed by a gradual recovery. A decrease in SERCA2a protein and mRNA content was shown from 1 month and remained for the following 2 months. Phospholamban content and its phosphorylation status were not modified. Acylphosphatase was unchanged at 1 month, but at 2 months this enzyme exhibited an increased activity, protein and mRNA expression. Morphological alterations consisting of the cytoskeletal architectures, intermyofibrillar oedema, swollen mitochondria and abnormality of the membrane system (T-tubule and SR cisternae) were particularly evident after 1 month but almost disappeared after 3 months. These results suggest that our overloaded hearts underwent a substantial recovery of their structural and biochemical properties at 3 months after surgery. A possible involvement of acylphosphatase in the modification of SR function is discussed.

Early changes induced in the left ventricle by pressure overload. An experimental study on swine heart.

The purpose of this study was to evaluate the early changes in sarcoplasmic reticulum (SR) function and the parallel morphological and hemodynamic modifications occurring in the heart following pressure overload. As regards SR function, we also explored the levels of acylphosphatase, an enzyme which might have a regulatory effect on the SR Ca(2+) pump by hydrolyzing the phosphorylated intermediate of this transport system. Pigs subjected to pressure overload by aortic stenosis for 6, 12, 24, 48, 72, and 96 h were compared to sham-operated controls. At each of the considered times both SR Ca(2+)-ATPase activity and Ca(2+) uptake, as well as acylphosphatase activity, were significantly enhanced in the pressure overloaded compared to the control hearts, with a maximal increase at 6 h; moreover, a positive and significant correlation was found between these parameters. The modifications in the activities of Ca(2+)-ATPase and acylphosphatase reflected an increased expression of these proteins, while phospholamban did not show significant changes in its concentration nor in its phosphorylation status. As for hemodynamic parameters, rapid changes in the left ventricular function were observed and especially the early hours following the aortic stenosis appeared to be crucial for the adjustment of heart function. The most relevant morphological finding was a focal disarrangement of the myofibrillar pattern which was very evident at 6 h, and progressively attenuated at later times. Taken together our data suggest that an early adaptation to the increased hemodynamic working overload is a consistent activation of the contractile apparatus which reflects, at least in part, an enhanced SR function. Besides the changes in Ca(2+) pump protein expression, increased acylphosphatase levels might also contribute to this effect.

Chronic cryptosporidiosis in patients with AIDS: stable remission and possible eradication after long-term, low dose azithromycin.

AIMS: To investigate the effectiveness of long term, low dose azithromycin treatment for chronic cryptosporidiosis in patients with AIDS. METHODS: Azithromycin was administered as initial daily treatment to 13 patients with AIDS: 6 patients received 500 mg for 30 to 40 days (mean 35); 3 patients received 1000 mg for 21 to 50 days (mean 37); and 4 patients received 1500 mg for 20 days. Nine of the 13 patients were also given low dose maintenance treatment with different schedules of azithromycin for 30 to 360 days (mean 129). Patients were monitored, during and after treatment, for parasite shedding in stool and for daily stool frequency and body weight. All but one patient had severe immunodeficiency. RESULTS: Long term, low dose maintenance treatment was associated with major clinical and parasitological benefits: there was probable eradication of infection in 2 patients, and 7 patients showed a complete response with persistent high decrease (5 patients) or clearance (2 patients) of parasite in stool. The drug was well tolerated, and there was no relapse either during treatment or during follow up (up to 21 months). These results were more impressive than those observed after the short term initial course of azithromycin, which was unable at any tested dose to achieve parasite clearance in stool (except in the patient with less advanced immunodeficiency) or to prevent relapse in 3 patients who discontinued treatment. Reversible side effects occurred with the 1500 mg daily dose. CONCLUSIONS: Long term, low dose azithromycin is well tolerated and may induce stable remission of chronic cryptosporidiosis in patients with AIDS. It may lead to probable eradication of the infection in some patients, even those with severe immunodeficiency.

Beneficial effects of the 21-aminosteroid U 74389G on the ischemia-reperfusion damage in pig hearts.

21-Aminosteroids (Lazaroids), acting as free radical scavengers and as membrane stabilizers, proved to have beneficial effects in various pathological conditions. In the present study we explored the effectiveness of one of these compounds, U 74389 G, in protecting pigs myocardium against the ischemia-reperfusion damage induced by transient coronary occlusion achieved by clampling the left anterior descending coronary artery. Animals were divided into three groups: control, untreated and treated. Control animals were operated but not subjected to ischemia-reperfusion; the untreated group underwent to ischemia-reperfusion without pharmacological treatment; while the treated group received the aminosteroid (4 mg/kg) before coronary occlusion and at the time of reperfusion. Specimens of myocardial tissue and blood samples were taken for morphological and biochemical studies. In the ischemic-reperfused myocardium of the untreated animals, the dominant morphological features were neutrophil infiltration, intercellular edema and severe swelling of mitochondria. All these alterations, notably neutrophil infiltration, were attenuated by aminosteroid treatment. As for the biochemical findings, the changes in adenine nucleotides and nucleosides levels, thus the reduction of energy charge, were reversed in the treated, but not in the untreated group. Myocardial concentration of malondialdehyde, which was undetectable in the control group, was raised in all the animals after reperfusion, but this effect was significantly less marked with aminosteroid treatment. In addition, the higher myocardial content of ascorbic acid and the reduced serum potential peroxidation exhibited by the treated animals compared with untreated group indicate an enhanced antioxidant protection induced by aminosteroid administration. On the other hand, the serum levels of myoglobin, cardiac troponin I and creatine kinase MB isoenzyme suggest the ability of the aminosteroid to attenuate the modifications of membrane permeability induced by ischemia-reperfusion injury. All these results lead to the conclusion that aminosteroid treatment, at least in the conditions of the present study, is effective in reducing the morphological and biochemical alterations occurring in ischemic-reperfused myocardium.

Vitamin E prevents neutrophil accumulation and attenuates tissue damage in ischemic-reperfused human skeletal muscle.

Neutrophil accumulation and the consequent production of oxygen-derived free radicals are involved in the pathogenesis of Ischemia-Reperfusion syndrome. In this study we investigated whether a treatment with Vitamin E, which has antioxidant properties, could attenuate the tissue damage by interfering with the influx of neutrophils within the ischemic and reperfused human skeletal muscle. To this purpose, patients undergoing aortic cross-clamping during the surgical repair of aortic abdominal aneurysm were studied as a model of ischemia-reperfusion of the lower limb muscles. Muscle biopsies from the right femoral quadriceps of patients not receiving and receiving Vitamin E pretreatment before surgery were taken: a) after the induction of anaesthesia, as control samples, and b) after a period of ischemia followed by 30 min of reperfusion. The tissue samples were either routinely processed for morphological study and immunohistochemical analysis to detect an altered expression of specific endothelial adhesion proteins, such as E-selectin and ICAM-1. The results obtained showed that Vitamin E administration was able to prevent the accumulation of neutrophils within the ischemic and reperfused muscle. This beneficial effect of Vitamin E was due to its ability to hinder the expression of E-selectin and ICAM-1, molecules known to increase the adhesiveness of endothelium to circulating neutrophils. After treatment with Vitamin E a marked attenuation of the reperfusion injury was also evident. In conclusion, Vitamin E treatment may be considered a valuable tool for protection against the ischemia-reperfusion damage of human skeletal muscle.

Morphological injury of the intestinal mucosa and infection in patients with AIDS. The role of combined tissue and stool examination.

AIMS: To define the relationship between morphological injury of the intestinal mucosa and infections in AIDS patients. METHODS: Forty-nine AIDS patients were examined by upper gastrointestinal (GI) endoscopy and 8 of them also by lower GI endoscopy. Biopsy specimens, taken from the lower duodenum, esophagus and rectum, were studied by light (L.M.) and transmission electron microscopy (T.E.M.). Stool examination for microorganisms was routinely performed in all patients. RESULTS: Microorganisms were detected in 37 of the 49 patients (75.5%) by combined tissue and stool examination. The histological study revealed villous atrophy, inter- and intra-enterocyte oedema and epithelial degenerative changes in most of the patients whether or not they had detectable microorganisms. CONCLUSIONS: Combined methods (endoscopy, L.M. and T.E.M., studies of tissue samples, microbiological study of stool samples) may be used to improve the documentation of infections and morphological injury of the intestinal mucosa in AIDS patients.