AB0097 EFFECT OF CYTOCHROME P450 METABOLITES OF ARACHIDONIC ACID IN RHEUMATOID ARTHRITIS

Background

Arachidonic acid (AA) is a polyunsaturated fatty acid, released in inflammatory disease, such as rheumatoid arthritis (RA). Cyclooxygenase (COX) and lypooxygenase (LOX) pathways have received greater attention than cytochrome P450 (CYP) pathway of AA, which also plays a significant role in RA. AA is a substrate of CYP enzymes through two different pathways: the ω-hydroxylase, and epoxygenase pathways, respectively. The epoxygenase gives rise to epoxyeicosatrienoic acids (EETs) (5,6-EET, 8,9-EET, 11,12-EET, 14,15-EET), whereas ω- hydroxylase produces hydroxyeicosatetraenoic acids (HETEs) [1].

Objectives

The aim of this study is to evaluate the role of Cytochrome P450 metabolites of arachidonic acid and their therapeutic targeting in rheumatoid arthritis.

Methods

Pubmed and Scopus databases were the main databases used to identify all the studies conformed to the eligibility criteria.

Results

CYP enzymes (CYP3A, CYP2C19, CYP2C9, CYP1A2) suppression was observed in the synovial fluid of RA patients with higher IL-6 levels. EETs inhibit bone resorption and osteoclastogenesis, have an important role in blocking inflammation by reducing TNFα, and are negatively linked with pro-inflammatory cytokines (IL-1, IL-6, IL-8)[2]. The anti-inflammatory effects of EETs are potentially attributed to peroxisome proliferator–activated receptor gamma (PPARγ) activation. EETs are also metabolized through soluble epoxide hydrolase (sEH) to dihydroxyeicsatrienoic acids (DHETs), which have a pro-inflammatory activity. On the other hand, 20-HETE deriving from CYP ω-hydroxylase pathway has pro-inflammatory effect [3]. Data have shown that the genetic variations of CYP could affect the individual susceptibility to RA [4].

Conclusion

sEH inhibitors (sEHi) can not only block the inflammation caused by EETs metabolite, but can also act on LOX and COX pathway, and can be used in chronic-phase arthritis to reduce both inflammation, and the pain. In a mouse model of RA, sEHi showed decent RA assessment score improvement [5]. Moreover, data suggest that sEHi inhibit also PGE2 production, and exert an additional anti-inflammatory effect in arthritis. Since NSAIDs can lead to gastric and cardiovascular problems, sEHi are considered a better pharmacological approach in inflammatory rheumatic disease. Despite the failure of some of sEHi to reach clinical trials, we believe that CYP-derived eicosanoids should be further studied as potential target in rheumatic disease. Dual inhibitors sEHI/5-LOX activating protein (FLAP) are also very promising compounds as they can inhibit leukotriene formation, without effecting the levels of anti-inflammatory pro-resolving mediators. In perspective we suggest that multiple ligands targeting different AA pathways or mediators should be further explored as potential targets for designing new compounds to treat RA patients.

References

[1]M. Hoxha, B. Zappacosta. CYP-derived eicosanoids: Implications for rheumatoid arthritis. Prostaglandins Other Lipid Mediat. 146 (2020) 106405.

[2]X. Xu, X.A. Zhang, D.W. Wang, The roles of CYP450 epoxygenases and metabolites, epoxyeicosatrienoic acids, in cardiovascular and malignant diseases, Adv. Drug Deliv. Rev. 63 (8) (2011) 597–609.

[3]D. Panigrahy, A. Kaipainen, E.R. Greene, S. Huang, Cytochrome P450-derived eicosanoids: the neglected pathway in cancer, Cancer Metastasis Rev. 29 (4) (2010) 723–735

[4]S. Puntarulo, A.I. Cederbaum, Production of reactive oxygen species by microsomes enriched in specific human cytochrome P450 enzymes, Free Radic. Biol. Med. 24 (7–8) (1998) 1324–1330

[5]J. Park, M.J. Cho, H.J. Park, Analgesic effects of soluble epoxide hydrolase inhibitor in K/BxN serum transfer arthritis mouse model, Anesth. Pain Med. 14 (2019) 76–94.

Disclosure of Interests

None declared

Urine Beta-Thromboglobulin Concentration or Beta-Thromboglobulin/Creatinine Ratio in Single Voided Urine Samples Cannot Be Reliably Used to Estimate Quantitative Beta-Thromboglobulin Excretion

Different procedures are currently used in the urine beta-thromboglobulin (BTG) assay. We investigated the reliability of limited urine collections and of different expressions of urine BTG results (concentration, urine BTG/creatinine ratio) for the measurement of hourly or daily BTG excretion rates. BTG was measured by a sensitive RIA method in various urine collections of normal subjects (n.80) and patients (n.120) with miscellaneous diseases where an enhanced in-vivo platelet activation could be expected. The BTG concentration in a 6-hour urine collection appeared to change in relation to the urine flow rate (r = -0.53 in normals, r = 0.27 in patients, p <0.01) and urine osmolality (r = 0.46 in normals, r = 0.31 in patients, p <0.01). In both normals and patients not a very good correlation was observed between the urine BTG/creatinine ratio and the BTG excretion rate (r = 0.54 and r = 0.48; p <0.001, respectively). Variable coefficients of correlation (r = 0.83-0.34) were observed between the BTG excretion rate of single voidings of the morning, afternoon-evening and night and the daily BTG excretion both in normals and patients. Reliable measurements of the BTG in urine should be expressed as the hourly excretion rate in a given period of the day for limited urine collections or as the daily excretion for 24-hour urine collections.

Folate, vitamin B12 and homocysteine status in an Italian blood donor population

BACKGROUND AND AIMS

The relevance of folate, other B-vitamins and homocysteine (Hcy) for the occurrence or prevention of several diseases has induced growing interest. Unfortunately, little evidence is available regarding B-vitamin concentrations in Italy. This study evaluated in a region of middle-southern Italy, folate, vitamin B12 and Hcy concentrations and the prevalence of their ideal blood levels. The main determinants of B-vitamins and Hcy were also considered.

METHODS AND RESULTS

Male and female blood donors (n=240), aged 18-66 years and living in Molise region (Italy), were enrolled in the study. They completed a brief questionnaire concerning fruit and vegetables intake, physical activity and smoking; serum and red blood cell (RBC) folate and serum vitamin B12 were measured by an immunoassay on an automated analyzer. Total Hcy was measured by high performance liquid chromatography (HPLC). Geometric means of serum folate, RBC folate and serum vitamin B12 were 10.8nmoll(-1), 426.0nmoll(-1) and 245.0pmoll(-1), respectively. Only 22.5%, 24.2% and 16.3% of blood donors showed an adequate level of serum folate, RBC folate or serum vitamin B12 respectively. When a cut-off of RBC folate ≥906nmoll(-1) was used no women of childbearing age had adequate levels. A geometric mean of 14.0μmoll(-1) was found for total Hcy, with an ideal concentration in 12.1% of subjects. Folate concentration was higher in women and non-smokers and in subjects with higher consumption of fruit and vegetable.

CONCLUSION

This study shows a low-moderate B-vitamins status in middle-southern Italy, associated with an inadequate fruit and vegetable consumption. A public health strategy should be undertaken to encourage a B-vitamin-rich diet with the addition of vitamin supplements or vitamin fortified foods in population subgroups with special needs.

Morpho-functional modifications of human neutrophils induced by aqueous cigarette smoke extract: comparison with chemiluminescence activity

Cigarette smoking plays an important role as a cause of morbidity and mortality in humans, involving respiratory, cardiovascular, digestive and reproductive systems. Tobacco smoke contains a large number of molecules, some of which are proven carcinogens. Although not fully understood, polymorphonuclear leukocytes seem to play a crucial role in the mechanisms by which tobacco smoke compounds are implicated in smoke-related diseases. In this paper the effects of an aqueous cigarette smoke extract on the expression of adhesion molecules of polymorphonuclear leukocytes together with the changes in the cell morphology have been related to the chemiluminescence activity. The results obtained show that polymorphonuclear leukocytes treated with aqueous cigarette smoke extract are significantly impaired, as suggested by the changes of chemiluminescence activity, of membrane receptors (CD18, CD62), myeloperoxidase expression and of cell morphology. Altogether the present data indicate that treated polymorphonuclear leukocytes are ineffectively activated and therefore unable to phagocytize zymosan particles.

Effect of cigarette smoke extract on the polymorphonuclear leukocytes chemiluminescence: influence of a filter containing glutathione

Cigarette smoking is known to be a risk factor for several chronic and neoplastic diseases. Many compounds formed by cigarette burning, ranging from particulate materials to water solutes and gaseous extracts, are considered to be noxious agents, and many biochemical and molecular mechanisms have been proposed for the toxic effects of cigarette smoke. The oral cavity and the upper respiratory tract represent the first contact areas for smoke compounds; even a single cigarette can produce marked effects on some components of the oral cavity, either chemical compounds, such as glutathione and enzymes, or cellular elements, such as polymorphonuclear leukocytes. Several studies suggest a protective role of glutathione against the noxious effects of tobacco smoke; the sulphydril groups of glutathione, in fact, could react with some smoke products, such as unsaturated aldehydes, leading to the formation of harmless intermediate compounds and simultaneously preventing the inactivation of metabolically essential molecules, such as some enzymes. In this paper we analyse the effect of a filter containing glutathione on the respiratory burst of polymorphonuclear leukocytes exposed to aqueous extract of cigarette smoke, measuring their chemiluminescence activity. The results of this paper indicate that the GSH-containing filter has a likely protective effect against the inhibition of cigarette smoke extract on polymorphonuclear leukocyte activity.

Hyperhomocysteinemia in acute Plasmodium falciparum malaria: an effect of host-parasite interaction

BACKGROUND

Plasmodium falciparum utilises the polyamine pathway, essential in proliferation and differentiation, and imposes an oxidative stress on host cell, enhancing the loss of glutathione.

METHODS

Standard hematological parameters were determined in 40 black African subjects with acute P. falciparum malaria, 30 aged 5-24 months, 5 aged 4-10 years and 5 aged 19-35 years. Plasma homocysteine, cysteine, glutathione and cysteinylglycine levels were measured by HPLC method. Twenty-eight healthy black children (15 aged 6-24 months and 13 aged 3-10 years) and 20 healthy black adults (aged 20-40 years) were also included as controls.

RESULTS

Plasma homocysteine levels were higher in all subjects with P. falciparum malaria and correlated positively with the disease severity and number of parasites, but negatively with Hb levels and patient ages. Cysteine level was found higher in all patients and markedly higher in 4-10 year old patients. Cysteinylglycine level was found lower particularly in 19-35 year old patients. Glutathione level was significantly lower in all patients.

CONCLUSIONS

The elevated level of homocysteine during acute P. falciparum infection suggests an imbalance in the folate cycle, which could be a consequence of the reduced availability of NADPH and Vit B12, caused by increased oxidative stress. This may suggest a selection for the C677T MTHFR allele, driven by P. falciparum in sub-Saharan regions. Hence Hcy level could be useful as a predictive parameter of severity, as well as of treatment efficacy.

[Primary malignant schwannoma of the uterine cervix: a malignant tumor with unusual behaviour. A case report]

Malignant tumors of peripheral nerves (MPNST) represent approximately 5-10% of all soft tissue sarcomas and usually are in relationship with a major nerve. Primary cervical malignant Schwannomas are very rare neural sheat tumors that, grossly and clinically, are misdiagnosed for other more frequent lesions of the uterine cervix. We report a case of primary cervical malignant Schwannoma in a 27 years old female with atypical bleeding. The lesion is characterized by densely packed spindle cells with nuclear atypia and high mitotic rate. Immuno-histochemical stains are positive for vimentin and S-100 but negative for HMB-45, keratins, desmin and actin. After 34 months the patient is disease free. To our knowledge, this is the seventh case described.

[Retroperitoneal Pacinian neuroma: report of a rare lesion in an uncommon location]

Pacinian neuroma is an extremely rare benign tumor which has only occasionally been reported in the literature. To date, this lesion has usually been observed in the hand and foot; only one had intra-abdominal localization. Local trauma is reported in the most of these cases. We describe the first case of retroperitoneal pacinian neuroma. The lesion was observed as an incidental finding in a 75-year-old man who underwent laparotomy for aortic aneurysm. Here are discussed the differential diagnosis and a complete literature review on the topic.

Inhibition of salivary enzymes by cigarette smoke and the protective role of glutathione

Tobacco smoke is involved in the pathogenesis of several diseases regarding different body systems, mainly cardiovascular and respiratory in addition to its local toxic effect in the oral cavity. The noxious effects of smoke compounds justify the high incidence of periodontal diseases, caries, and neoplastic diseases of oral tissues in smokers. Some toxic components of tobacco smoke, unsaturated and saturated aldehydes, could interact with thiol rich compounds, leading to structural and functional modification of these molecules. Previous papers have demonstrated an in vitro significant decrease of some enzymatic activities, both in plasma and in saliva, following external addition of aldehydes or exposure to cigarette smoke (CS). Furthermore, the same studies underlined the protective effect exerted by the addition of glutathione (GSH) against the damaging role of smoke aldehydes. In this study some salivary enzymes (lactic dehydrogenase [LDH], aspartate aminotransferase [AST] and amylase), and total GSH were measured in 20 volunteers smokers, before and just after smoking a single cigarette. All enzymatic activities showed a significant inhibition following a single cigarette, probably due to the interaction between smoke aldehydes and -SH groups of the enzyme molecules. Moreover, the percentage of the enzymatic inhibition showed a negative correlation with the basal level of salivary GSH. Our results emphasize that not only one cigarette is sufficient to impair the salivary enzymatic activities but also strengthen the proposed protective role of GSH against the noxious biochemical effects of CS.

Is homocysteine a pro-oxidant?

High plasma homocysteine concentrations have been found to be associated with atherosclerosis and thrombosis of arteries and deep veins. The oxidative damage mediated by hydrogen peroxide production during the metal-catalyzed oxidation of homocysteine is to date considered to be one of the major pathophysiological mechanisms for this association. In this work, a very sensitive and accurate method was employed to measure the effective production of H2O2 during homocysteine oxidation. Furthermore, the interaction of homocysteine with powerful oxidizing species (hypochlorite, peroxynitrite, ferrylmyoglobin) was evaluated in order to ascertain the putative pro-oxidant role of homocysteine. Our findings indicate that homocysteine does not produce H2O2 in a significant amount (1/4000 mole/mole ratio of H2O2 to homocysteine). Moreover, homocysteine strongly inhibits the oxidation of luminol and dihydrorhodamine by hypochlorite or peroxynitrite and rapidly reduces back ferrylmyoglobin, the oxidizing species, to metmyoglobin. All these results should, in our opinion, lead to a rethinking of the commonly held view that homocysteine oxidation is one of the main causative mechanisms of cardiovascular damage.

Hyperhomocysteinemia and prevalence of polymorphisms of homocysteine metabolism-related enzymes in patients with inflammatory bowel disease

OBJECTIVES

Patients with inflammatory bowel disease (IBD) have an increased risk of thrombotic complications. Moreover, a hypercoagulable state has been hypothesized as a contributing factor in the pathogenesis of IBD. Recently, a growing amount of interest has focused on mild-to-moderate hyperhomocysteinemia as a risk factor for thromboembolic disease. We aimed to evaluate the prevalence of hyperhomocysteinemia in patients with IBD and to investigate the contribution of genetic defects in the enzymes involved in homocysteine (Hcy) metabolism and vitamin status in determining increased levels of plasma total Hcy (tHcy).

METHODS

The concentrations of tHcy, folate, and vitamin B12 as well as the prevalence of methylenetetrahydrofolate reductase (MTHFR) 677C to T mutation and the 68-bp insertion at exon 8 of cystathionine beta-synthase (CBS) were measured in patients with IBD and healthy controls.

RESULTS

In all, 17 out of 64 IBD patients (26.5%) and four out of 121 (3.3%) controls had hyperhomocysteinemia with a statistically significant difference (p < 0.0001). No significant difference was found between IBD patients and controls with regard to the prevalence of homozygotes for the C677T variant (TT) of MTHFR or the prevalence of heterozygotes for the CBS-gene mutation (IN). Among the IBD patients the only independent factor significantly associated with hyperhomocysteinemia was folate deficiency (p = 0.0002), regardless of the MTHFR or the CBS genotype.

CONCLUSIONS

IBD patients have a higher prevalence of hyperhomocysteinemia than do healthy controls. Folate deficiency is the only independent risk factor in developing hyperhomocysteinemia.

Effect of aqueous cigarette smoke extract on the chemiluminescence kinetics of polymorphonuclear leukocytes and on their glycolytic and phagocytic activity

Water-soluble extracts of cigarette smoke are easily formed in some body compartments, such as saliva or fluid lining alveolar spaces, and can act on both cellular and extracellular compartments. In this paper we have analysed the effect of aqueous smoke extract on some metabolic and functional aspects of polymorphonuclear leukocytes. In particular, the following cellular aspects were studied: chemiluminescence, glycolysis, membrane fluidity and microscopic interaction with zymosan particles. While chemiluminescence and glycolytic activity are highly inhibited, no effect of smoke extract on membrane fluidity was observed. Moreover, the response of luminol-dependent chemiluminescence was significantly delayed, while that of lucigenin-dependent chemiluminescence was anticipated. Furthermore, the phagocytic ability of neutrophils pretreated with aqueous smoke extract was also significantly hindered. All these results might indicate that the finely tuned activity of polymorphonuclear leukocytes is somehow hampered by the aqueous extract of cigarette smoke in a way which makes these cells less effective against bacteria and more noxious towards surrounding tissues.

A fast chemiluminescent method for H(2)O(2) measurement in exhaled breath condensate

BACKGROUND

Breath condensate can give useful information on volatile compounds produced at alveolar level. Actual concentration of H(2)O(2) in breath condensate is dependent on its production at alveolar level and on the efficacy of the detoxifying systems, catalase, glutathione peroxidase, etc.

METHODS

In the present paper, a simple chemiluminescent method for the determination of the H(2)O(2) collected in exhaled breath is shown and data of both smokers and nonsmokers volunteers are presented.

RESULTS

The chemiluminescent response is linear up to 100 micromol/l H(2)O(2). The analytical sensitivity is about 0.01 micromol/l. Most of the nonsmokers have a H(2)O(2) content lower than 0.05 micromol/l, while smokers have a content ranging from 0.1 to 0.6 micromol/l.

Efficacy of intratumoral delivery of mitoxantrone in recurrent malignant glial tumours

Ninety-nine patients bearing recurrent malignant glioma sequentially selected according to strict eligibility criteria (72 GBL and 27 AA) entered the study. All patients were previously managed with radiotherapy 60 Gy total dose and chemotherapy with nitrosoureas and platinum compounds. At recurrence they were subdivided in homogeneous groups, all treated with the same systemic chemotherapy protocol: 27 GBL (group A) only systemically treated, 20 GBL (group B) treated also locally by delivering 4mg of mitoxantrone every 20 days through the Ommaya reservoire, and 25 GBL (group C) treated with a second surgery and locally as group B. Of the AA group, 13/27 were treated locally trough the Ommaya reservoir after repeat surgery. A trend to different demographic features among subgroups (with locoregionally treated patients and patients undergoing repeat surgery being younger than the others) was seen in this non-randomized study, but this was not statistically significant. Median overall survival was 27, 26 and 15.5 months respectively for groups c, b and a (log-rank = 0.1). After tumor recurrence median survival was 16.8, 12 and 6.6 months respectively for groups c, b and a (log-rank = 0.001) For the 29 AA, overall survival was 48.5 and 100 months (log-rank = 0.03) if treated locally with second tumor debulking. Our results stress the opinion that a second operation could be indicated only if it is a part of a therapeutic protocol to allow a locoregional treatment. Moreover we can finally assume that local delivery of chemotherapy after tumor recurrence, possibly extends patients survival but certainly improves the number of long-survivors.

Interaction between hyperhomocysteinemia and inherited thrombophilic factors in venous thromboembolism

Hyperhomocysteinemia is an established risk factor for deep vein thrombosis. Factor V Leiden has been reported to potentiate the thrombotic risk related with severe hyperhomocysteinemia, being more represented in thrombotic patients with homocystinuria as compared with patients without a history of thrombosis. The results concerning the interaction between moderate hyperhomocysteinemia and inherited thrombophilic factors such as Factor V Leiden or the prothrombin G20210A mutation are contradictory. The relative risk for venous thrombosis has been reported to be increased 10- to 50-fold in patients carrying both hyperhomocysteinemia and inherited thrombophilia in comparison with normal controls, suggesting a synergistic interaction, yet other studies failed to confirm such conclusion. The heterogeneity of these findings is in part due to the small number of individuals with double defects, leading to statistically unreliable results. Genotyping for mutations that are possible causes of moderate hyperhomocysteinemia, such as the thermolabile variant (C677T) of methylenetetrahydrofolate reductase (MTHFR), does not seem useful to identify individuals at higher risk for venous thromboembolism. In fact, in most of the studies the presence of the C677T MTHFR homozygous genotype does not increase the thrombotic risk associated with Factor V Leiden or the prothrombin mutation.

Effect of homocysteine on polymorphonuclear leukocyte activity and luminol-dependent chemiluminescence

Homocysteine is a non-protein-forming sulphur amino acid that plays an important role in remethylation and trans-sulphuration processes. In recent years, a high plasma homocysteine concentration has been implied as a possible pathophysiological factor in atherosclerosis and artery and deep vein thrombosis, probably through generation of H(2)O(2), enhanced platelet activity and increased production of macrophage-derived tissue factor. Furthermore, an increase of polymorphonuclear leukocyte (PMN) activity mediated by homocysteine-generated H(2)O(2) has also been reported. Because some preliminary experimental results in our laboratory did not confirm this effect of homocysteine on PMNs, we investigated the effect of homocysteine on the activity of PMNs, measured by their luminol-dependent chemiluminescence. Moreover, we also studied the effect of homocysteine in a luminol-hypochlorite chemiluminescent system. Our results clearly indicate that homocysteine at micromol/L concentrations (10-100 micromol/L) slightly inhibits neutrophil chemiluminescence, while it strongly inhibits the luminescence of the luminol-hypochlorite system. Therefore, the hypothesis that homocysteine induces an increase of H(2)O(2)-mediated neutrophil activity is not supported and, probably, the common opinion that views the H(2)O(2) generated by homocysteine as a possible mechanism for cardiovascular damage should be reconsidered.

Effect of aqueous extract of cigarette smoke on peripheral blood polymorphonuclear leukocytes chemiluminescence

Cigarette smoke induces a vast cohort of deleterious effects on biological structures. In the present paper, the effect of aqueous extract of cigarette smoke on the activity of polymorphonuclear leukocytes was studied. Although the aqueous extract of cigarette smoke inhibits the luminol oxidation catalysed by horseradish peroxidase, it strongly interacts with polymorphonuclear leukocytes and inhibits their phorbol-induced chemiluminescence in the presence of either luminol or lucigenin. The results indicate that at least some of the components of the aqueous extract of cigarette smoke may strongly interfere with polymorphonuclear cells, contributing to the deleterious effects of smoke products.

High total antioxidant activity and uric acid in tracheobronchial aspirate fluid of preterm infants during oxidative stress: an adaptive response to hyperoxia?

The effect of O2 exposure, expressed by mean daily fractional inspired oxygen concentration (FiO2), was evaluated during the first 6 d of life in the tracheobronchial aspirate fluid of 16 mechanically ventilated preterm infants in terms of both antioxidant response and oxidative damage, by measuring total antioxidant activity, uric acid concentrations and protein carbonyl content. Each day linear regression analysis was performed and a positive correlation was found between total antioxidant activity and FiO2 during the study period, especially on day 2 of life (r = 0.91, p < 0.0001), but uric acid correlated only in the first 3 d, especially on the 2nd day (r = 0.83, p < 0.0001). No correlation was found between carbonyl content and FiO2. The highest values of total antioxidant activity (416 and 790 micromol l(-1)) were found in 2 babies ventilated with highest FiO2: 1 and 0.80, respectively. Total antioxidant activity was not detectable or was very low in the babies not requiring O2 therapy. The highest value of uric acid (270 micromol l(-1)) was found in the baby ventilated with 100% oxygen. Uric acid concentrations obtained in these babies were much higher then those reported in the bronchoalveolar lavage fluid of adults. Preterm babies seem to have an antioxidant response in the tracheobronchial aspirate fluid following an oxidative stress and uric acid may be physiologically important as an antioxidant of the respiratory tract, especially during the first days of life.

Blood bank conditions and RBCs: the progressive loss of metabolic modulation

BACKGROUND

Human RBC metabolism is modulated by the cell oxygenation state. Among other mechanisms, competition of deoxyhemoglobin and some glycolytic enzymes for the cytoplasmic domain of band 3 is probably involved in modulation. This metabolic modulation is connected to variations in intracellular NADPH and ATP levels as a function of the oxygenation state of the cell, and, consequently, it should have physiologic relevance. The present study investigates the effect of storage on this metabolic modulation and its relationship with the alteration of membrane protein composition.

STUDY DESIGN AND METHODS

RBCs stored in CPD-saline-adenine-glucose-mannitol were assayed for glucose uptake and partition between glycolysis and the pentose phosphate pathway at high and low oxygen saturation by nuclear magnetic resonance spectroscopy after 1, 14, 21, 35, and 42 days of storage. Membrane protein composition was determined by SDS-PAGE on Days 1, 14, 35, and 42. Metabolic values and 2,3 DPG concentration were also measured after rejuvenation for 1 hour at 37 degrees C with pyruvate-inosine-phosphate-adenine solution on Day 21.

RESULTS

Metabolic differences between RBCs incubated at high and low oxygen saturation decreased during storage, and, on Day 35, the two groups did not have significant differences (p = 0.111). SDS-PAGE showed that membrane protein composition was concurrently modified. The percentage of unmodified band 3 decreased during storage, principally between Days 14 and 35. In rejuvenated RBCs, oxygen-dependent modulation was not restored.

CONCLUSIONS

RBCs stored in CPD-saline-adenine-glucose-mannitol do show a progressive loss of oxygen-dependent metabolic modulation, which is not restored after rejuvenation and which seems partly related to modifications in membrane proteins, mainly band 3.

Adult and fetal haemoglobin J-Sardegna [alpha50(CE8)His-->Asp]: functional and molecular modelling studies

Haemoglobin (Hb) J-Sardegna [alpha50(CE8)His-->Asp] is a haemoglobin variant characteristic of subjects from the island of Sardinia. Here we report a study of the functional properties of both fetal and adult Hb J-Sardegna. The results indicate that adult Hb J-Sardegna displays an oxygen affinity that is higher than that of adult Hb only in the presence of 2,3-diphosphoglycerate (2,3-DPG). On the contrary, at 20 degrees C, the oxygen affinity of fetal Hb J-Sardegna is identical to that of normal fetal haemoglobin, both in the presence and in the absence of 2,3-DPG. A significant difference between these two systems (i.e. a higher oxygen affinity of fetal Hb J-Sardegna) shows up very clearly only when temperature is increased to 37 degrees C. Hence in fetal Hb, the main effect of the amino acid substitution is a decrease in the overall enthalpy change of oxygenation. The results outline the role of the alpha(1)-beta(1) interface in assessing the thermodynamics of oxygen binding. The functional properties of both adult and fetal Hb J-Sardegna have been interpreted at the structural level in light of the results obtained by a computational modelling approach performed in comparison with HbA and Hb Aichi, a variant characterized by a different mutation [alpha50(CE8)His-->Arg] at the same position.

Embryonal tumors in the adult population: implications in therapeutic planning

The natural history of neuroectodermal tumors is still debated as far as prognostic factors are concerned; the same uncertainty applies to the optimal radiotherapy schedule and even more to the presumptive additive effect of chemotherapy. The rarity of these tumors and the heterogeneity of management make interpretation of literature data also more difficult. We evaluated clinical course in a cohort of 39 patients, including 31 with medulloblastoma (MB) and 8 with primitive neuroectodermal tumors (PNET). All patients were treated with radiotherapy, a standardized chemotherapy protocol including PCV scheme, and a second-line chemotherapy with cisplatin and etoposide (VP16) at recurrence. In 27 patients, intrathecal chemotherapy was also delivered. Median follow-up was 10.8 years. Overall, PNET had a worse outcome as compared to MB: median survival times were 42.8 vs. 92.6 months, respectively (p = 0.05). At 5 years, 45% of MB patients are alive. No significant difference in disease-free period was found between patients of different age, desmoplastic variant, tumor localization, or extent of surgery. Patients considered to be "high risk" had a significantly shorter disease-free period as compared with low-risk patients (27 vs. 54.7 months, p = 0.04). Systemic or intrathecal chemotherapy did not influence progression-free survival (PFS). However, in the majority of chemotherapy-treated patients, a low-dose craniospinal radiotherapy was also delivered. This combination of treatments may have avoided the expected increased percentage of failure. Moreover, more than half of recurrent patients had a partial response to chemotherapy that extended survival for approximately 3 years. Repeated surgery and chemotherapy at recurrence favorably influenced survival time.

Purine metabolites and malondialdehyde in platelets of diabetic patients

The concentration of some of the purine nucleotides and their metabolites together with that of malondialdehyde (MDA) have been measured in resting and stimulated platelets of type 1 and type 2 diabetic patients. While control platelets show a net decrease of guanosine triphosphate (GTP) (3.1 vs. 2.3 nmol per 10(9) platelets) and guanosine diphosphate (GDP) (3.0 vs. 2.0 nmol per 10(9) platelets) and a significant increase of adenosine (0.04 vs. 0.55 nmol per 10(9) platelets) with platelet stimulation, platelets of type 1 and type 2 diabetic patients have a lesser change of these metabolites (GTP, 2.6 vs. 2.4; GDP, 2.3 vs. 2.4; adenosine, 0.04 vs. 0.30 (P < 0.05 vs. control) nmol per 10(9) platelets in type 1 diabetics; GTP, 2.4 vs. 2.7; GDP, 2.4 vs. 2.1; adenosine, 0.08 vs. 0.32 (P < 0.05 vs. control) nmol per 10(9) platelets in type 2 diabetics). These results indicate that the change (stimulated minus resting) of GTP, GDP and adenosine in diabetic platelets is significantly different from that of controls (P < 0.001). Moreover, the amount of MDA produced during platelet activation seems to be lower than controls only in type 2 diabetes (1.81 vs. 2.86 nmol per 10(9) platelets, P < 0.05). These results seem to indicate that a difference in the pattern of platelet nucleotides could be an important feature even in well-controlled diabetes, while MDA is probably modified only in association with the late vascular complications of diabetes.

Prevalence of mild hyperhomocysteinaemia and association with thrombophilic genotypes (factor V Leiden and prothrombin G20210A) in Italian patients with venous thromboembolic disease

Mild hyperhomocysteinaemia is an established risk factor for deep vein thrombosis (DVT); few data concerning its potential interaction with thrombophilic genotypes are available at the present time. We investigated 121 thrombosis-free individuals and 111 patients with at least one objectively confirmed episode of DVT. A thrombophilic condition (deficiency in antithrombin, protein C and S, factor V Leiden, prothrombin G20210A) was detected in 25.2% of the patients; mutant factor V or prothrombin genotypes were present in 6.6% of the controls. Hyperhomocysteinaemia was found in 14.4% of patients and 3. 3% of the controls, with a 3.7-fold increase in risk for DVT (95% CI 1.1-12.3). Adoption of different cut-off levels for definition of hyperhomocysteinaemia did not substantially change the magnitude of the risk. Carriership of both hyperhomocysteinaemia and factor V Leiden or prothrombin G20210A was detected in 2.7% of patients for each combination and in none of the controls. An approximate estimate of 30-fold increased risk in carriers of both hyperhomocysteinaemia and factor V Leiden and 50-fold increased risk in carriers of both hyperhomocysteinaemia and prothrombin G20210A was calculated, suggesting a synergistic interaction between hyperhomocysteinaemia and such thrombophilic genotypes. Yet statistical analysis is highly unstable due to the small number of individuals with combined defects. Further investigations on large series of patients are needed.

Effect of smoking one cigarette on antioxidant metabolites in the saliva of healthy smokers

Concentrations of glutathione, uric acid and total antioxidant activity, expressed as Trolox (a water-soluble vitamin E analogue) equivalent, were measured in the saliva of healthy non-smokers and smokers before and just after smoking a single cigarette. There was no statistically significant difference between smokers and non-smokers in uric acid concentrations and total radical-trapping antioxidant capacity, but glutathione concentrations were significantly (p < 0.05) higher in smokers. Smoking of a single cigarette induced a significant reduction in glutathione concentration (p < 0.05). Salivary antioxidant power may affect individual sensitivity toward tobacco stress.

[Serum ferritin determination: is it useful in the early diagnosis of renal carcinoma?]

The aim of the study was to evaluate the usefulness of ferritin as an early marker in the diagnosis of renal cell carcinoma (RCC). The Authors dosed the pre-operative concentration of ferritin in the sera of 22 patients (16 males and 6 females) affected by stage I-II, according to Robson's classification, RCC. Plasma concentrations of ferritin were matched for the presence of tumor and for the tumor volume. The results did not evidence any relationship between plasma concentration of ferritin and the presence of renal cancer. In the same way a linear correlation did not show any significant relationship between serum concentration of ferritin and tumor diameter. Ferritin does not seem to be a usefull marker in the early diagnosis of renal cell carcinoma.

Very late onset Friedreich's ataxia without cardiomyopathy is associated with limited GAA expansion in the X25 gene

Molecular analysis of spinocerebellar ataxias revealed a pathologic GAA expansion in the gene encoding frataxin in six adult patients from three families. These patients, carrying expanded alleles in the low-range size, had an exceptionally late onset and lacked cardiomyopathy, pointing to phenotypic variability of Friedreich's ataxia. Both mitotic and gametic instability of the expanded triplet repeat were present in these families.

Modulation of ADPase and t-PA release by radiographic contrast media in bovine aortic endothelium

Vascular endothelial injuries induced by intravascular administration of radiographic contrast agents may be clinically relevant to the development of thrombosis and platelet activation. In this connection, we investigated the in vitro effects induced by iodamide, iopamidol, and ioxaglate on vascular endothelial ADPase activity and tissue plasminogen activator (t-PA) release in bovine aortic endothelium, in order to extend knowledge required to evaluate endothelial compatibility of radiographic contrast media. Undiluted and Tris-diluted contrast agent formulations were employed, and mannitol and sucrose hyperosmolar solutions were used as comparison. Results demonstrated that the high-osmolar ionic contrast agent iodamide, and to a lesser extent, the low-osmolar nonionic agent iopamidol, stimulated endothelial ADPase activity of the aortic endothelium; the low-osmolar ionic agent ioxaglate left endothelial ADPase activity unchanged. Furthermore, the diluted formulations of iodamide and iopamidol, as well as high-osmolar mannitol and sucrose solutions, were devoid of activity in ADPase. This suggests that the endothelial ADPase stimulation induced by both radiographic contrast media was a hyperosmolar-independent pharmacodynamic activity. Iopamidol and ioxaglate reduced endogenous t-PA release from bovine aortic endothelium only in undiluted formulation, while iodamide showed this inhibiting action in both diluted and undiluted formulations. No effect was observed when using mannitol solutions at different osmolarity values. Our in vitro findings agree with published data on the different thrombotic tendency attributed to the contrast agents used, suggesting endothelial enzymatic activities (ADPase and t-PA release) as suitable tools for evaluating endothelial vessel wall compatibility with radiographic contrast media.

Resting and stimulated human polymorphonuclear leucocytes from type-2 diabetic patients: change in purine nucleotide pattern

It is known that polymorphonuclear leucocytes are deeply involved in the inflammatory complications of diabetes mellitus, showing many functional and biochemical abnormalities. Because adenine and guanine metabolites exert an important role in many metabolic aspects of phagocytic cells, we have investigated the pattern of purine metabolites during the respiratory burst of polymorphonuclear leucocytes in order to characterize any difference that may be significantly correlated with the abnormal neutrophil function of diabetic patients. The results obtained show clearly that polymorphonuclear leucocytes from diabetic patients are characterized by an abnormal pattern of purine nucleotides and their metabolites. In particular, the concentration of adenine and guanine triphosphates and the net amount of adenosine triphosphate hydrolysed during neutrophil stimulation by phorbol ester is higher in diabetic than in control cells. Moreover, higher values of adenosine monophosphate, inosine monophosphate and inosine have been found in diabetic cells. The behaviour of guanosine triphosphate is highly interesting. In fact, in addition to the higher concentration found in diabetic polymorphonuclear leucocytes, stimulation by phorbol ester induces a net decrease in guanosine triphosphate whereas control neutrophils show a slight increase. These findings have been associated with the ease with which diabetic neutrophils undergo metabolic activation and sustain an inflammatory response.

Errors in Huntington disease diagnostic test caused by trinucleotide deletion in the IT15 gene

Images

Psychiatric symptoms do not correlate with cognitive decline, motor symptoms, or CAG repeat length in Huntington's disease

OBJECTIVES

To investigate the hypothesis that psychiatric disturbances in Huntington's disease are related to degree of cognitive or motor compromise and to determine correlations between CAG repeat length within the gene for Huntington's disease and disease severity.

DESIGN

Consecutive series of patients with Huntington's disease.

SETTING

Neurological specialty hospital.

PATIENTS

Seventeen men and 12 women from 24 families.

MAIN OUTCOME MEASURES

The Hamilton Psychiatric and Anxiety Rating Scales and Brief Psychiatric Rating Scale were used to assess psychiatric disturbances; Folstein's Quantified Neurological Examination to evaluate motor status; and the Mini-Mental State Examination, Raven Progressive Matrices), Phonemic Verbal Fluency Test, Short Tale Test, Visual Search Test, and Benton's Visual Orientation Line Test to evaluate cognitive function. The length of the CAG repeat sequence in the Huntington's gene was determined by quantitative polymerase chain reaction.

RESULTS

Cognitive test scores correlated significantly with each other; of these, results of the Visual Search and Short Tale tests correlated significantly with the Folstein's Quantified Neurological Examination score (P = .05 and P = .03, respectively). Results of the Folstein's Quantified Neurological Examination also correlated with the illness duration and the length of the CAG repeat. Although psychiatric scores correlated significantly among themselves (P < .01), neither cognitive compromise, motor deterioration, nor CAG length were related to the extent of psychiatric compromise. Patients who were depressed when they were examined tended to have a history of psychiatric disorders.

CONCLUSIONS

The lack of correlation between disease severity and psychiatric disturbances indicates that psychiatric disorders progress nonlinearly, possibly because of differential degeneration of the striatal-cortical circuits; the possibility that psychiatric disorders are prevalent in certain families with a member who has Huntington's disease is being further investigated. The lack of correlation between CAG length and cognitive and psychiatric variables needs further investigation.

Lactate dehydrogenase activity of platelets in diabetes mellitus

Lactate dehydrogenase (L-lactate : NAD+ oxidoreductase, EC 1.1.1.27) activity has been measured on the subpopulations of platelets obtained from blood of diabetic patients. Small, but not large platelets show a lactate dehydrogenase activity higher than that of controls. Moreover, a positive statistically significant correlation was found between the activity of small platelets and the percent of glycated haemoglobin, while no correlation was obtained in the case of large platelets. Since we previously demonstrated that lactate dehydrogenase activity of small platelets is exceedingly high in some clinical and experimental conditions, our results not only confirm the involvement of platelets in diabetes but provide more evidence in support of our previous hypothesis of a relationship between lactate dehydrogenase and in-vivo platelet activation.

Progression of motor and cognitive impairment in Parkinson's disease

We performed a longitudinal study (mean follow-up 86.7 months) to evaluate motor and mental deterioration in patients with Parkinson's disease. Of the original 91 patients, only 61 could be re-examined 7 years later and 11 of these had become demented (PD-Dems). PD-Dems were older with worse motor and, obviously, cognitive performance than non-demented parkinsonian patients (PDs). A global cognitive decay index (DI) was calculated for each patient. Based on this, non-demented PDs were further split into 38 stable parkinsonian patients (S-PDs) with DI-30% to +30%, and 10 deteriorated but non-demented parkinsonian patients (D-PDs) with a DI worse than -30% (as had PD-Dems). D-PDs were older and had greater motor impairment than S-PDs but did not differ from PD-Dems on these measures. D-PDs and PD-Dems deteriorated especially in attention, visuospatial and executive ability tests. Ageing seems to be the main predictive factor for mental deterioration.

Platelet lactate dehydrogenase activity in systemic lupus erythematosus: correlation with anticardiolipin antibodies

OBJECTIVE

To evaluate lactate dehydrogenase (LDH) activity in platelet subpopulations in systemic lupus erythematosus (SLE) and to correlate platelet LDH activity with concentrations of anticardiolipin antibody (aCL).

METHODS

Twelve female patients with SLE and 12 age matched female control subjects were studied. Platelets were separated on the Percoll gradient, their density values controlled by density marker beads. LDH activity was measured after platelet lysis, expressed as nU/fl. ELISA were used to measure levels of IgG and IgM aCL.

RESULTS

A significant increase of LDH activity with a significant correlation to IgG and IgM aCL were found in small, light platelets with a volume < 5 mu 3 compared to large, dense platelets and to controls. LDH activity did not correlate with immunoglobulin classes, anti-DNA antibodies, and complement fractions in small and large SLE platelets.

CONCLUSION

Our data suggest a possible chronic activation of subpopulations of small platelets in patients with SLE independent of thrombotic process. Low levels of aCL can mediate small platelet activation. Quantitative and qualitative analysis of the small, light platelets can serve a clinical diagnostic purpose as an in vivo platelet activation index in SLE.

Salivary electrolytes in treated hypertensives at low or normal sodium diet

The aim of this study was to investigate possible abnormalities in salivary electrolytes in hypertensives treated with ace-inhibitors (ACE-I) or calcium antagonists (Ca-ANT) at low or normal sodium intake. Hypertensives treated with ACE-I (n.14) or Ca-ANT (n.22) and 13 normotensives were studied during normal or restricted Na intake. Na, K, Ca, Mg and Cl were determined in saliva samples collected by using a standardized adsorption procedure (SALIVETTE). Na intake was evaluated by determination of the 24-hr urinary Na excretion. Similar concentrations of Na, K, Ca, and Cl were found in normotensives and in hypertensives treated with ACEI or Ca-ANT both at low or normal Na diet. Magnesium in saliva appeared reduced in ACEI-treated hypertensives (0.28 +/- 0.06 mmol/l) in comparison to the similar values of normotensives (0.53 +/- 0.05) and Ca-ANT treated hypertensives (0.54 +/- 0.07). In normotensives and in treated hypertensives lowering of Na intake did not change the salivary content of Ca, Mg and Cl but produced in saliva a reduction of Na associated to a rise in K. Salivary Na/K ratio was significantly correlated with 24 hr urinary Na excretion in normotensives (r = 0.77; p < 0.05) and in hypertensives treated with ACE-I (r = 0.74; p < 0.05) or Ca-ANT (r = 0.62; p < 0.05). The low salivary magnesium in ACE-I-HT may have a role in the occasional ACEI-dependent dysgeusia. Salivary Na/K ratio may be used as a rough index of Na intake in treated hypertensives.

Aminotransferases and lactate dehydrogenase in saliva of diabetic patients

Although inflammatory or degenerative changes in salivary glands have been demonstrated in genetic animal models of diabetes mellitus and in experimental diabetes, no information is available in diabetics on the possible leakage in saliva of cytosolic enzymes as markers of salivary cell injury. Aspartate (GOT) and alanine (GPT) aminotransferases and lactate dehydrogenase (LDH) were determined in saliva samples collected by the Salivette method from well-controlled insulin-dependent (IDDM n = 11) and non-insulin-dependent (NIDDM n = 18) diabetic patients and from age-cross-matched healthy subjects (n = 33). In IDDM salivary concentrations of GOT (112.55 +/- 23.94 UI/L) and LDH (1120.27 +/- 168.31 UI/L) were similar to those found in the NIDDM (90.94 +/- 19.64, and 1255.43 +/- 221.40 UI/L respectively), but higher (p < 0.05) than those observed in normal subjects (33.09 +/- 3.71, and 423.58 +/- 39.94, UI/L respectively). GPT was higher in NIDDM than IDDM, which in turn was higher than in normal subjects (42.78 +/- 14.72, 16.45 +/- 3.74 and 6.85 +/- 1.52 UI/L respectively). Salivary and serum values of GOT, GPT and LDH were not correlated. Determination of cytosolic enzymes in saliva may be useful for monitoring the diabetic involvement of salivary glands.

Platelet heterogeneity based on lactic dehydrogenase activity

Mean lactic dehydrogenase (LDH) activity of human platelets is about 5 nU/platelet; expressed on a cell volume basis, it is 0.5 nU/fl. Platelet separation by means of centrifugation on a Percoll discontinuous gradient gives different subpopulations with a clear-cut change of LDH at a mean platelet volume (MPV) of about 6 fl. The LDH content of platelets with a MPV > 6 fl is constant (about 0.5 nU/fl), while that of small platelets (3 < MPV < 6 fl) is inversely correlated with the MPV and reaches a value of 1.5-2.0 nU/fl. Because small platelets are granule-depleted, we suggest that platelet LDH activity be considered as an in vivo activation index.

Lactic dehydrogenase activity of platelet subpopulations during pregnancy

We determined the LDH activity of different platelet subpopulations throughout pregnancy. While no changes in LDH content occurred in large, dense platelets, a significant change was found in small, light platelets.

Bone metastasis associated with shunt-related peritoneal deposits from a pineal germinoma. Case report and review of the literature

The case of a 15-year-old boy with a pineal germinoma is reported. The patient first underwent a ventriculoperitoneal (VP) shunt followed by a stereotactic biopsy, then, because of the rapidly deteriorating neurological status, an emergency craniotomy with subtotal removal of the tumour was performed. Two months after surgery, a left femoral metastasis and extensive peritoneal lesions became evident; they were regarded as due to haematogenous and VP shunt spread of the germinoma. At that time, extremely high serum levels of placental alkaline phosphatase were detected. The patient died 6 months after the initial diagnosis. The occurrence of extraneural metastases as well as of shunt related peritoneal deposits from primary intracranial germinoma is discussed. As far as we know this is the first reported case of a combination of haematogenous as well as VP shunt spread of a pineal germinoma.

Lactic dehydrogenase and glycolytic activity of human platelets in uncomplicated pregnancy

Lactic dehydrogenase (LDH) of isolated platelets was determined in a group of 103 normally pregnant and 19 unpregnant women. LDH activity is significantly increased in the last trimester of pregnancy while the isoenzyme pattern does not vary in relation to LDH increase. Moreover, glucose consumption and lactic acid production are linearly correlated to platelet LDH activity.

Effects of calcium channel blockers on the endothelial release of von Willebrand factor after exercise in healthy subjects

Von Willebrand factor (vWF) is known to play a relevant role in the development of atherosclerotic lesions by promoting platelet adhesion to injured endothelial cells. An increase in cytosolic calcium has been shown to be associated with the in vitro release of vWF from endothelial cells. The aim of our investigation was to examine the effect of some calcium channel blockers on the release of vWF antigen (vWF:Ag) induced by exercise in two groups of eight healthy subjects during a randomized crossover study between placebo and calcium channel blockers. Placebo and verapamil (80 mg) or nicardipine (10 mg) were given orally at an interval of 2 weeks three times on the day before and once on the morning of the study day. Measurements of plasma vWF:Ag were made at rest and after a progressive maximal exercise on a cycloergometer. A significant increase in absolute values of vWF:Ag was observed after exercise in the subjects given a placebo in both verapamil (0.397 +/- 0.074 U/ml) and nicardipine (0.327 +/- 0.036 U/ml) groups, p less than 0.05. With use of verapamil the rise in vWF:Ag was blunted and not significant (0.123 +/- 0.081 U/ml) whereas a larger increase in vWF:Ag was found in the subjects given nicardipine in comparison with placebo (0.593 +/- 120 U/ml; p less than 0.05). No correlations were observed between exercise-induced changes in systolic or diastolic blood pressure, heart rate, blood lactate level, or pH and vWF:Ag changes in the subjects given a placebo or in those given calcium channel blockers.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular reactivity, plasma markers of endothelial and platelet activity and plasma renin activity after mental stress in normals and hypertensives

Endothelial injury and platelet activation, mechanisms known to be involved in vascular lesions, may promote the development of cardiovascular disorders possibly associated with mental stress. Plasma markers of platelet activation (beta-thromboglobulin, BTG) and of endothelium activity (factor VIII/von Willebrand factor, FVIII/vWf) and plasma renin activity (PRA) were determined in 17 healthy normotensive volunteers and in 21 hypertensives without target-organ damage before and after mental stress (a colour-word conflict test). The aim of the study was to compare cardiovascular reactivity with the stress-induced changes in platelet and endothelium activity. Individual responses in BTG and factor FVIII/vWf after the colour-word conflict test were markedly different, but significant mean increases were observed in both groups with no difference in the degree of response and in the percentage of responders. No correlations were found among the changes in plasma variables or between cardiovascular reactivity (systolic and diastolic blood pressure and heart rate) and the changes in BTG, FVIII/vWf and PRA. These findings suggest that hypertensive patients do not have an abnormal platelet or endothelium reactivity to mental stress, at least when the disease is free of vascular complications. This dissociation of stress-induced variability in BTG and FVIII/vWf and cardiovascular reactivity indicates that these indices could be used as independent markers of mental stress.