Urinary Prostasin

Prostasin is a serine peptidase hypothesized to regulate epithelial sodium channel (ENaC) activity in animals or on in vitro cultured cells. We investigated whether urinary prostasin may be a candidate marker of ENaC activation in humans. We studied 10 healthy volunteers and 8 hypertensive patients with raised aldosterone-to-renin ratio before and after spironolactone or saline/Florinef suppression test, respectively. Four healthy subjects were also studied before and after saline. Urinary prostasin was evaluated by SDS-PAGE, 2D maps, and Western blotting. Every sample of normotensive individuals was compared with the corresponding sample of urine collected after spironolactone or saline; every sample of hypertensive patients was compared with the corresponding sample of urine collected after saline or Florinef. Prostasin was detectable in all subjects regardless of gender, dietary sodium intake, and spironolactone treatment. Spironolactone (100 mg) increased urinary Na+/K+ ratio and decreased urinary prostasin in normotensives in whom the renin/aldosterone axis was activated by a low Na+ intake, but it was ineffective in individuals with high Na+ intake. Saline infusion also reduced prostasin in normotensive subjects. In contrast, prostasin paradoxically increased in urine of patients affected by primary aldosteronism after volume expansion. By 2D immunoblotting, several protein isoforms were observed, some of them being overexpressed after inhibition tests in patients with primary aldosteronism. In addition to a "basal" aliquot of prostasin, constitutively released in human urine regardless of sodium balance and aldosterone activation, there exists a second "aldosterone-responsive" aliquot modulated by Na+ intake and potentially suitable as candidate marker of ENaC activation.

Serum selenium concentrations in chronic pancreatitis and controls

BACKGROUND

In the light of the recent hypothesis that one cause of pancreatic damage may be related to the toxic action of oxygen free radicals [Braganza JM. The pathogenesis of pancreatitis. Manchester: Manchester University Press; 1991; Braganza JM. A framework for the aetiogenesis of chronic pancreatitis. Digestion 1998;59(Suppl. 4):1-12], we were prompted to assess the role of selenium in pancreatic disease.

OBJECTIVE

The objective of the study was to establish whether or not there is any correlation between selenium levels and the degree of impairment of exocrine pancreatic function in patients suffering from chronic pancreatitis.

PATIENTS

Two groups of subjects were recruited, the first consisting of 38 patients with clinically quiescent chronic pancreatitis of alcoholic origin and the second of 48 control subjects selected from among healthy volunteers attending our Transfusion Centre.

METHODS

Body mass index, smoking and drinking habits were evaluated and selenium serum levels were assayed in all subjects. The patients with pancreatic disease were subdivided into three groups on the basis of lipase output assayed with a duodenal probe. RESULTS.: Selenium serum levels in the chronic pancreatitis group as a whole were found to be significantly lower than in the control group, but when they were analysed in the three distinct subgroups, a significant difference was found against control group only in the groups with severe and moderate exocrine pancreatic insufficiency.

CONCLUSIONS

The mean serum selenium levels were lower in chronic pancreatitis patients than control.

The MTHFR 1298A>C polymorphism and genomic DNA methylation in human lymphocytes

Methylenetetrahydrofolate reductase (MTHFR) balances the pool of folate coenzymes in one-carbon metabolism for DNA synthesis and methylation, both implicated in carcinogenesis. Epidemiologic studies have shown that two functional polymorphisms in MTHFR gene, 677C>T and 1298A>C, are related to increased cancer risk. We aimed to analyze lymphocyte DNA from 198 subjects to evaluate the MTHFR 1298A>C polymorphism and folate status affecting genomic DNA methylation as a possible mechanism underlying the relationship between MTHFR polymorphisms and cancer susceptibility. Carriers of the 1298AA wild-type genotype showed lower genomic DNA methylation compared with 1298AC or 1298CC genotypes [3.72 versus 8.59 or 6.79 ng 5-methyl-2'-deoxycytidine (5-mCyt)/microg DNA, P < 0.0001 and P = 0.007, respectively]. When DNA methylation was evaluated according to plasma folate status, only 1298AA with low folate levels revealed diminished DNA methylation (P < 0.0001). Moreover, when the two MTHFR polymorphisms were concomitantly evaluated at the low folate status, DNA methylation was reduced only in 1298AA/677TT compared with 1298AA/677CC (3.11 versus 7.29 ng 5-mCyt/microg DNA, P = 0.001) and 1298CC/677CC genotypes (3.11 versus 7.14 ng 5-mCyt/microg DNA, P = 0.004). However, the high prevalence of 677TT mutants within the 1298AA group (79%) and the similar biochemical features of 1298AA/677CC and 1298CC/677CC combined genotypes suggest that the gene-nutrient interaction affecting DNA methylation in 1298AA is mainly due to the coexistence of the 677TT genotype and that the 1298A>C polymorphism may convey its protective effect not through this interaction but through another pathway in one-carbon metabolism. Further mechanistic studies are warranted to investigate how single polymorphisms as well as MTHFR combined genotypes exert their effect on cancer susceptibility.

Interaction between metabolic syndrome and PON1 polymorphisms as a determinant of the risk of coronary artery disease

The enzyme serum paraoxonase plays an important role in antioxidant defences and prevention of atherosclerosis. Metabolic syndrome (MS) is a clinical condition associated with increased oxidant stress and cardiovascular mortality. Two common polymorphisms of serum paraoxonase, PON1 Leu(55)Met and Gln(192)Arg, have been postulated to modulate the cardiovascular risk. We studied 915 subjects with angiographic documentation: 642 subjects with coronary atherosclerosis and 273 with normal coronary arteries. Two hundred and twenty-four subjects met the diagnostic criteria of MS. We found a significant interaction between MS and both the PON1 polymorphisms in determining the risk of coronary artery disease (P<0.05 by likelihood-ratio test). The 55Leu and the 192Arg alleles, associated with reduced protection against lipid peroxidation, were associated with coronary artery disease only in the MS subgroup. Subjects with MS and both 55Leu and 192Arg alleles had significantly increased risk (OR=9.38 with 95% CI=3.02-29.13 after adjustment by multiple logistic regression) as compared to subjects without MS and with 55Met/Met-192Gln/Gln genotype. No increased risk was found for subjects with MS and the 55Met/Met-192Gln/Gln genotype. This study highlights a potential example of genetic (paraoxonase polymorphisms)-clinical (MS) interaction influencing cardiovascular risk.

Induction of endothelial cell damage by hCMV molecular mimicry

Molecular mimicry between infectious agents and normal human host cell components is one of the mechanisms responsible for autoimmunity. Among infectious agents, some viruses represent ideal candidates for their ability to infect human cells, where they are harbored for the duration of the life of the host in a latent state. Human cytomegalovirus (hCMV) infection has been implicated in the pathogenesis of vascular damage in systemic sclerosis (SSc) and atherosclerosis. Based on recent data describing a cause and effect relationship between hCMV and endothelial cell damage in SSc and atherosclerosis, we propose that the immune response to particular hCMV proteins might result in autoaggression through a mechanism of molecular mimicry of normally expressed endothelial cell surface molecules.

Apolipoprotein C-III, n-3 polyunsaturated fatty acids, and "insulin-resistant" T-455C APOC3 gene polymorphism in heart disease patients: example of gene-diet interaction

BACKGROUND

Apolipoprotein C-III (apo C-III) is a marker of cardiovascular disease risk associated with triglyceride (TG)-rich lipoproteins. The T-455C polymorphism in the insulin-responsive element of the APOC3 gene influences TG and apo C-III concentrations. Long-chain n-3 polyunsaturated fatty acids (PUFAs) contained in fish have well-known apo C-III-lowering properties.

METHODS

We investigated the possibility of an interactive effect between the APOC3 gene variant and erythrocyte n-3 PUFAs, suitable markers of dietary intake of fatty acids, on apo C-III concentrations in a population of 848 heart disease patients who had coronary angiography.

RESULTS

In the population as a whole, apo C-III concentrations were significantly inversely correlated with total erythrocyte PUFAs, but the correlation was not significant when only -455CC homozygous individuals were taken into account. In the total population and in subgroups with the -455TT and -455CT genotypes, the relative proportions of individuals presenting with increased apo C-III (i.e., above the 75th percentile value calculated on the entire population after exclusion of individuals taking lipids-lowering medications) decreased progressively as the n-3 PUFA and docosahexaenoic acid concentrations increased. The opposite situation was observed in the homozygous -455CC subgroup, in whom increasing erythrocyte n-3 PUFA and docosahexaenoic acid concentrations were associated with higher proportions of individuals with high apo C-III. A formal interactive effect between genotype and n-3 PUFAs was confirmed even after adjustment for possible confounding variables [age, sex, body mass index, smoking, coronary artery disease (CAD)/CAD-free status, or use of lipid-lowering medications] by logistic models.

CONCLUSION

Patients homozygous for the -455C APOC3 variant are poorly responsive to the apo C-III-lowering effects of n-3 PUFAs.

A pilot study on the efficacy of ketorolac plus tramadol infusion combined with erythrocytapheresis in the management of acute severe vaso-occlusive crises and sickle cell pain

One of the major causes of hospitalization for patients with sickle cell disease (SCD) are vaso-occlusive crises (VOC), which are characterized by acute pain and organ damage related to the presence of dense red cells. Here we report a pilot study which combined balanced analgesia with tramadol plus ketorolac and erythrocytapheresis. Key words: sickle cell disease, therapeutic erythrocytapheresis, HbS, visual analog scale, vaso-occlusive crisis.

Selective intra-arterial terlipressin infusion stops acute lower gastrointestinal bleeding: a case report and review of the literature

Acute gastrointestinal bleedings are considered clinical emergency events and implicate a difficult medical decision-making process, in particular in poor surgical candidates. Here, we report one case with acute lower gastrointestinal bleeding, for the first time, treated with selective intra-arterial infusion of terlipressin (triglycyl lysine-vasopressin), a long-acting vasopressin analogue. The patient was affected by lung adenocarcinoma with abdominal metastasis and presented severe lower intestinal bleeding. Using selective angiography, the middle colic artery was catheterized and terlipressin was infused as follows: 1.5 mg in bolus (21 microg/kg), then 1.5 mg (21 microg/kg) intra-arterially in 20 min, then 1.5 mg in bolus (21 microg/kg), determining the cessation of the lower gastrointestinal bleeding. Since no cases of intra-arterial selective infusion of terlipressin have been reported in the literature, terlipressin may represent a new useful tool in pharmaco-angiographic strategy. The present case should prompt its consideration for further clinical studies.

Aldosterone to Renin ratio in a primary care setting: the Bussolengo study

The aim of the study was to evaluate the prevalence of hypertension associated with an elevated aldosterone to renin activity ratio (ARR) in a sample of adults aged 35-74 yr, randomly selected from the population register of the Bussolengo Health District (northern Italy) and representative of the total population of the district. Subjects (n = 1462) were randomly selected from the population register and examined by their general practitioners. Complete data for 1348 individuals were available for final statistical analysis. Apart from verapamil or alpha-blockers, no hypotensive drugs were allowed during the 4 wk before assay. Direct active renin and aldosterone were measured in the plasma of hypertensive patients after 2 h in the upright posture. Of 412 identified hypertensive patients, 287 subjects agreed to give blood (70% response rate). An aldosterone to active renin ratio (AARR) of 32 pg/ml was taken as the cut-off value, equivalent to an ARR of 50 ng/dl/ng/ml.h. An elevated AARR was observed in 32.4% of the hypertensive patients, with increased prevalence in females and in people aged 55 yr or older. As an elevated AARR is frequent in the general hypertensive population, screening should not be limited to the patients referred to specialist units.

Efficacy of intravenous immunoglobulin in chronic idiopathic pericarditis: report of four cases

Human intravenous immunoglobulins (hIVIgs) are used in two broad categories of diseases: immunodeficiency and autoimmunity. Among the immune-mediated diseases hIVIgs are of benefit in idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia, and dermatomyositis. Chronic idiopathic pericarditis (CIP) is a chronic disease of unknown origin characterized by recurrent episodes of pericardial inflammation. The cause of the recurrence is unknown, although in some cases it may be traced to a viral infection and to the presence of antimyocardial antibodies. Since a viral infection can induce an autoimmune process through a mechanism of molecular mimicry, and since the optimal therapy for prevention of the recurrences has not been established, we reasoned that treatment with hIVIgs could be beneficial in our patients unresponsive to previous immunosuppressive therapies. We describe four patients affected by CIP treated with monthly high-dose hIVIgs (0.4 g/kg daily for 5 consecutive days) for five times followed by administration every 2 months. Three of the four patients could permanently discontinue steroid therapy and are still in remission after years of follow-up. Our experience suggests that hIVIgs therapy may be a useful and safe treatment for CIP in steroid-dependent patients.

Low plasma vitamin B-6 concentrations and modulation of coronary artery disease risk

BACKGROUND

Low concentrations of pyridoxal-5'-phosphate (PLP), the active metabolite of vitamin B-6, are associated with high C-reactive protein (CRP) concentrations. Both low PLP and elevated inflammatory markers, such as high-sensitivity CRP (hs-CRP) and fibrinogen, are related to higher risk of coronary artery disease (CAD).

OBJECTIVES

The objectives were to evaluate the relation between PLP and acute-phase reactants in affecting CAD risk and to estimate the risk of CAD related to low plasma PLP, either alone or in combination with high concentrations of acute-phase reactants and other classic risk factors for CAD.

DESIGN

A case-control study was conducted with 742 participants: 475 with severe multivessel CAD and 267 free from coronary atherosclerosis (CAD-free). We measured plasma PLP, fibrinogen, hs-CRP, and serum lipid concentrations and all major biochemical CAD risk factors, including total homocysteine.

RESULTS

A significant, inverse, graded relation was observed between PLP and both hs-CRP and fibrinogen (P < 0.001). The prevalence of PLP concentrations in the lower half of the population (<50th percentile: 36.3 nmol/L) was significantly higher among CAD patients than among CAD-free subjects (P < 0.001). The odds ratio for CAD risk related to low PLP concentrations after adjustments for the major classic CAD risk factors, including hs-CRP and fibrinogen, was 1.89 (95% CI: 1.18, 3.03; P = 0.008). The CAD risk as a result of low PLP was additive when considered in combination with elevated hs-CRP concentrations or with an increased ratio of LDL to HDL.

CONCLUSION

Low plasma PLP concentrations are inversely related to major markers of inflammation and independently associated with increased CAD risk.

Randomized placebo-controlled trial comparing fluticasone aqueous nasal spray in mono-therapy, fluticasone plus cetirizine, fluticasone plus montelukast and cetirizine plus montelukast for seasonal allergic rhinitis

BACKGROUND

Corticosteroids are considered to be particularly effective in reducing nasal congestion and are therefore recommended as first-line treatment in allergic rhinitis patients with moderate to severe and/or persistent symptoms.

OBJECTIVE

We compared the clinical efficacy of fluticasone propionate aqueous nasal spray (FPANS) 200 microg given once daily, administered in mono-therapy or combined therapy with a H1 receptor antagonist (cetirizine, CTZ) or with a leukotriene antagonist (montelukast, MSK), and the combined therapy of CTZ plus MSK in the treatment of patients affected by allergic rhinitis to Parietaria during natural pollen exposure. In addition, we examined the effect of the treatment on eosinophil counts and eosinophil cationic protein (ECP) in nasal lavage performed at beginning of season, during season and at the end of the season.

METHODS

One hundred patients aged 12-50 years (mean+/-SD 31.8+/-9.6) with a history of moderate to severe Parietaria pollen-induced seasonal allergic rhinitis were selected. A randomized, double-blind, double dummy, placebo (PLA)-controlled, parallel-group study design was used. Patients were treated FPANS 200 microg once daily (n=20) or with FPANS 200 microg once daily, plus CTZ (10 mg) in the morning (n=20), or with FPANS 200 microg once daily, plus MSK (10 mg) in the evening (n=20) or with CTZ (10 mg) in the morning plus MSK in the evening (n=20) or matched PLA (n=20). Assessment of efficacy was based on scores of daily nasal symptoms and on eosinophil counts and ECP in nasal lavage.

RESULTS

All treatments showed significant differences (P<0.001) compared with PLA in terms of total symptom, rhinorrhea, sneezing and nasal itching scores. Concerning nasal congestion on waking and daily only the groups treated with FPANS in mono-therapy or in combined therapy showed significant differences compared with PLA. Comparing the group treated with FPANS alone and the groups treated with FPANS plus CTZ, we found significant differences for total symptom score (P=0.04) and for nasal itching (P=0.003). The comparison between FPANS plus CTZ and FPANS plus MSK showed significant difference for nasal itching (P=0.003). Finally, there were significant differences between the group treated with FPANS and the group treated with CTZ plus MSK for total symptom score (P=0.009), for nasal congestion on waking (P<0.001) and nasal congestion daily (P<0.001). Also the comparisons between the group treated with FPANS plus CTZ and the group treated with CTZ plus MSK demonstrated significant differences (P<0.001) for total symptom, for nasal congestion on waking and for nasal congestion on daily, for rhinorrhea (P=0.04) and for nasal itching (P=0.003) scores. Concerning the comparison between the group treated with FPANS plus MSK and the group treated with CTZ plus MSK we found significant differences for total symptom score (P=0.005), for nasal congestion on waking (P<0.001) and for nasal congestion on daily (P<0.001). No other differences were observed between the groups. Concerning blood eosinophil counts, significant differences were found between the treatments with FPANS in mono-therapy or in combined therapy with PLA group during and at the end of the season (P=0.0003 and P<0.0001, respectively). Concerning eosinophils and ECP in nasal lavage, all treatments showed significant differences (P<0.001) compared with PLA. Besides, there were significant differences (P<0.001) between the groups treated with FPANS alone or in combined therapy and the group treated with CTZ plus MSK.

CONCLUSION

The results of this comparative study demonstrate that FPANS is highly effective for treating patients affected by allergic rhinitis, with efficacy exceeding that of CTZ plus MSK in combined therapy. In addition, the regular combined therapy of FPANS plus CTZ or plus MSK would not seem to offer substantial advantage with respect to FPANS in mono-therapy in patients affected by seasonal allergic rhinitis.

Urinary nitrite/nitrate concentrations and total antioxidant capacity in patients with chronic hepatitis C in therapy with interferon and ribavirin

In this study we tried to elucidate the role of nitric oxide (NO) in chronic hepatitis C in relation to antioxidant status, since the mechanisms by which hepatitis C virus (HCV) causes cell damage and the factors underlying its resistance to therapy are not well understood. Before and after one and six months of therapy with alpha-interferon and ribavirin, we measured nitrite/nitrate urinary levels, total antioxidant capacity and selenium serum concentrations in 14 patients with chronic hepatitis C and in 9 healthy subjects. Before therapy, mean urinary nitrite/nitrate levels of patients were not different from those of healthy subjects, but after a 6-month treatment with alpha-interferon and ribavirin, these NO metabolites were higher in virologically negative patients (responders). Moreover, while no changes in selenium were observed in all patients, total antioxidant capacity was significantly higher in non-responders and well correlated with hyperuricemia (due to cell damage) observed in these subjects. Instead, uric acid decreased as free molecule in serum in responders, while we found the excretion of high NO levels as nitrite/nitrate. Our data allow us to hypothesize a role for NO as predictive of the success of therapy, since nitrite/nitrate increase in the urine of some patients precedes disappearance of the virus observed at the end of therapy.

Comparing tacrolimus ointment and oral cyclosporine in adult patients affected by atopic dermatitis: a randomized study

BACKGROUND

Atopic dermatitis (AD) is a chronic allergic inflammatory disease, which manifests itself with eczematous skin lesions.

OBJECTIVE

We compared the clinical efficacy of tacrolimus ointment (0.1%) given twice a day and oral cyclosporine (3 mg/kg) given once daily. Rescue medication for itching included cetirizine 10-20 mg (equal to one or two tables).

METHODS

Thirty patients, aged 13-45 years (mean+/-SD 27.1+/-10.9), with a history of moderate-to-severe AD were randomized to treatments, 15 patients for each treatments. Assessment of efficacy was based on SCORAD, on scores of daily itching, erythema, interference with sleep, due to the skin condition and days without use of cetirizine tablets. SCORAD, measured on a scale (0-103), was evaluated before treatment (0) and at 7, 14, 21, 28, 35 and 42 days after treatment. Similarly, the means of daily symptoms, on a scale (0-3), were evaluated before the treatment (0) and at 7, 14, 21, 28, 35 and 42 days after treatment; finally, on day without use of cetirizine tablets. The safety of the study treatments was assessed through haematologic, biochemical and urinary testing and on systolic and diastolic blood pressures and heart rate measurements.

RESULTS

SCORAD decreased in the two treatment groups 14 days after the beginning of the period study. However, the patients in tacrolimus ointment group reported significantly lower SCORAD than those treated with oral cyclosporine. Overall SCORAD, as assessed by the area under the curve (AUC) day(0-42) (score/day), was significantly lower in the tacrolimus ointment group when compared with oral cyclosporine (P<0.001). Similarly, AUC day(0-42) (score/day) for itching, erythema and number of nights without interference with the sleep due to skin condition were significantly lower in the group of patients treated with tacrolimus compared with those treated with cyclosporine (P=0.003, 0.005 and 0.01, respectively). As regards the use of rescue medication, expressed by median of number of days without use of anti-H(1), it was significantly lower in the group treated with tacrolimus (82.5) than in the cyclosporine group (76.5) (P=0.03). There were no appreciable changes in haematological and biochemical indices, in both treatments groups.

CONCLUSION

The results of this comparative study demonstrate that tacrolimus ointment twice daily and cyclosporine administered orally once daily are effective on SCORAD, daily symptoms and anti-H(1) rescue. When we compared tacrolimus and cyclosporine there was a faster onset of action in the group treated with tacrolimus. The two drugs presented the same safety. However, these data support the preferential use of topical tacrolimus 0.1% in AD, because cyclosporine has potential side-effects.

Established and experimental treatments for sickle cell disease

Sickle cell disease (SCD) is characterized by the presence of sickle hemoglobin (HbS), which has the unique property of polymerizing when deoxygenated. The sickling process is markedly accelerated when intracellular concentration of HbS is increased. Due to the unique dependence of HbS polymerization on its cell concentration, a slight reduction in HbS concentration is likely to have a beneficial effect on the kinetic of polymerization and on the generation of dense, dehydrated red cells. The pathophysiology of acute and chronic clinical manifestations of SCD is strictly related to the hemoglobin cyclic polymerization, to the generation of dense, dehydrated red cells and to the interaction between sickle red cells and abnormal activated vascular endothelial cells. In the present paper we have reviewed the principal therapeutic strategies and we have explored the future treatment options for sickle cell disease. Therapy of sickle cell disease is based on two major goals. The first one is the decrease in intracellular HbS concentration obtained with agents activating fetal hemoglobin synthesis, such as hydroxyurea (HU) or with erythrocyte-active agents blocking different red cell membrane ion pathways and preventing sickle cell dehydration. The second one is based on therapeutic strategies, which may reduce sickle cell-endothelial adhesive events.

[Pyogenic sacroiliitis complicated by iliopsoas muscle abscess]

Both pyogenic sacroiliitis and iliopsoas muscle abscess are uncommon infectious entities, and their coexinstence has been reported in very few patients. We present here the case of a woman who developed a large iliopsoas abscess as a consequence of a pyogenic sacroiliitis, initially misdiagnosed as a common sciatica and treated with corticosteroids. The patient was cured by the surgical drainage of the abscess and a long-lasting antibiotic treatment. We discuss diagnostic difficulties linked to the two infectious entities, their possible pathogenic connections, the role of imaging procedures, and therapeutic options. We conclude that pyogenic sacroiliitis and the potential evolution to an iliopsoas abscess must be taken into consideration in the differential diagnosis of lower back pain, especially if fever is a concomitant sign.

Erythrocyte aging in neurodegenerative disorders

In the present paper, we have reviewed the principal studies on red cell membrane abnormalities associated with neurodegenerative disorders. In the literature, two lines of investigation may be recognized: one based on the hypothesis of the presence of an oxidative environment responsible for red cell oxidative damage in Alzheimer's disease (AD), Alzheimer's dementia type (DAT) and Parkinson' disease (PD); the other one based on the identification of structural and/or functional abnormalities in red cell membrane band 3 and/or in red cell membrane lipid composition in "neuroacanthocytosis". In AD, DAT and PD patients, an increased red cell membrane lipid peroxidation suggests an increase red cell oxidative damages and precocious red cell aging. In "neuroacanthocytosis", grouping chorea-acanthocytosis, Mcleod syndrome and abetalipoproteinemia, the red cells are characterized by thorn or spur-like protrusions, known as "acanthocytes". The presence of circulating acanthocytes, characterized by abnormalities in red cell band 3 structure and/or function, is associated with increase levels of anti-band 3 antibodies which are physiologically produced against aged red cells and are known to mediate red cell removal from the peripheral circulation by macrophages. We have reviewed the mechanism(s) of the loss of red cell membrane stability and of the precocious red cell aging in neurodegenerative disorders.

Monosodium benzoate hypersensitivity in subjects with persistent rhinitis

BACKGROUND

Very few data are available from the literature on whether nonatopic subjects affected by persistent rhinitis may show the appearance of objective symptoms of rhinitis after the ingestion of food additives such as tartrazine (E102), erythrosine (E127), monosodium benzoate (E211), p-hydroxybenzoate (E218), sodium metabisulphite (E223), and monosodium glutamate (E620). It is still unclear whether the ingestion of food additive may cause, as well, a consensual reduction of nasal peak inspiratory flow (NPIFR). Therefore, we used a double-blind placebo-controlled (DBPC) study to evaluate this hypothesis.

PATIENTS AND METHODS

Two hundred and twenty-six consecutive patients (76 males and 150 females) aged 12-60 years (mean age 40.2 +/- 16.3 years). After 1 month of an additive-free diet regimen, an open challenge was carried out (food additive-rich diet for 2 weeks). After this period, challenges were administered in a DBPC manner using the above-mentioned substances under investigation.

RESULTS

Twenty of 226 subjects (8.8%) reported an improvement of the symptoms of rhinitis after additive-free diet. More precisely, six of 226 (2.6%) were symptom-free and 14 of 226 (6.2%) showed an improvement in their symptoms after an additive-free diet. As far as the results for DBPC are concerned, 20 challenges with monosodium benzoate induced both objective (i.e. sneezing and rhinorrhoea) and subjective symptoms (nasal blockage and nasal itching) of rhinitis with reduction of NPIFR >/=20%, 45 challenges induced subjective symptoms of rhinitis (i.e. nasal blockage and nasal itching), without reduction of NPIFR >/=20% of the basal value, two with tartrazine, seven with erythrosine, 19 with monosodium benzoate, three with p-hydroxybenzoate, six with sodium metabisulphite, and eight with monosodium glutamate, respectively.

CONCLUSIONS

The observation that nonatopic persistent rhinitis may be caused by the frequent, probably daily, ingestion of small doses of a nontolerated substance is intriguing and suggests that at least some patients with 'chronic vasomotor rhinitis' may be intolerant to a particular food additive. Therefore, food additives can be considered triggers or aggravating factors, rather than aetiological factors.

Interaction between smoking and PON2 Ser311Cys polymorphism as a determinant of the risk of myocardial infarction

BACKGROUND

Increased oxidative stress is thought to play a role in the pathogenesis of the atherothrombotic process. Paraoxonases (PONs) are closely related antioxidant enzymes encoded by clustered genes on chromosome 7q. We evaluated three PON polymorphisms (PON1 Leu55Met and Gln192Arg; PON2 Ser311Cys) as possible risk factors for coronary atherosclerotic disease (CAD) and/or its main thrombotic complication, myocardial infarction (MI).

MATERIALS AND METHODS

We studied 890 subjects with angiographic documentation of coronary vessels (272=CAD-free; 618=CAD). In the CAD group, 341 subjects had a previous MI.

RESULTS

Frequencies of various genotypes were not significantly different between CAD-free subjects and the entire CAD population. In the latter group, there were more carriers of the PON2 311Cys variation among those who had suffered a MI than among those who had not (P<0.01 by chi2). The adjusted OR for MI among PON2 311Cys carriers was 1.5 (95%CI, 1.03-2.19). A gene-environmental interaction was found between PON2 Ser311Cys and smoking. Smoking by itself was associated with an increased MI risk. Among smokers, however, the MI risk was related to PON2 genotype: Cys/Cys homozygotes (OR=5.3; 95%CI, 1.7-16.4) and Ser/Cys heterozygotes (OR=2.1; 95%CI, 1.3-3.6) were at greater risk than Ser/Ser subjects (OR=1.2; 95%CI, 0.8-1.8). The PON2 polymorphism did not influence the MI risk among nonsmokers.

CONCLUSIONS

In CAD subjects, a proportion of the risk of MI may be influenced by the interaction between smoking and a polymorphism in the antioxidant enzyme PON2.