Adenosine administration produces an antidepressant-like effect in mice: evidence for the involvement of A1 and A2A receptors

This study investigated the effect of adenosine in the forced swimming test (FST) and the tail suspension test (TST) in mice, and the contribution of adenosine A1 and A2A receptors to adenosine's antidepressant-like effect. The immobility time in the FST was reduced by adenosine given either by i.p. (5-10 mg/kg) or i.c.v. (0.01-10 microg/site) route. Adenosine (1-10 mg/kg, i.p.) also produced an antidepressant-like effect in the TST. No treatment affected locomotion in an open-field. The anti-immobility effect of adenosine (10 mg/kg, i.p.) in the FST was prevented by i.p. pretreatment of mice with caffeine (3 mg/kg), DPCPX (2 mg/kg) and ZM241385 (1 mg/kg). CHA (0.05 mg/kg, i.p.) and DPMA (1-5 mg/kg, i.p.) also produced an antidepressant-like effect in the FST. This is the first report of an antidepressant-like effect of adenosine in mice, apparently mediated through an interaction with A1 and A2A receptors.     

A double cryptic chromosome imbalance is an important factor to explain phenotypic variability in Wolf-Hirschhorn syndrome

A total of five Wolf-Hirschhorn syndrome (WHS) patient with a 4p16.3 de novo microdeletion was referred because of genotype-phenotype inconsistencies, first explained as phenotypic variability of the WHS. The actual deletion size was found to be about 12 Mb in three patients, 5 Mb in another one and 20 Mb in the last one, leading us to hypothesize the presence of an extrachromosome segment on the deleted 4p. A der(4)(4qter --> p16.1::8p23 --> pter) chromosome, resulting from an unbalanced de novo translocation was, in fact, detected in four patients and a der(4)(4qter --> q32::4p15.3 --> qter) in the last. Unbalanced t(4;8) translocations were maternal in origin, the rec(4p;4q) was paternal. With the purpose of verifying frequency and specificity of this phenomenon, we investigated yet another group of 20 WHS patients with de novo large deletions (n = 13) or microdeletions (n = 7) and with apparently straightforward genotype-phenotype correlations. The rearrangement was paternal in origin, and occurred as a single anomaly in 19 out of 20 patients. In the remaining patient, the deleted chromosome 4 was maternally derived and consisted of a der(4)(4qter --> 4p16.3::8p23 --> 8pter). In conclusions, we observed that 20% (5/25) of de novo WHS-associated rearrangements were maternal in origin and 80% (20/25) were paternal. All the maternally derived rearrangements were de novo unbalanced t(4;8) translocations and showed specific clinical phenotypes. Paternally derived rearrangements were usually isolated deletions. It can be inferred that a double, cryptic chromosome imbalance is an important factor for phenotypic variability in WHS. It acts either by masking the actual deletion size or by doubling a quantitative change of the genome.     

Circulating inflammatory mediators during start of fever in differential diagnosis of gram-negative and gram-positive infections in leukopenic rats

Gram-negative and gram-positive infections have been considered the most important causes of morbidity and mortality in patients with leukopenia following chemotherapy. However, discrimination between bacterial infections and harmless fever episodes is difficult. Because classical inflammatory signs of infection are often absent and fever is frequently the only sign of infection, the aim of this study was to assess the significance of serum interleukin-6 (IL-6), IL-10, macrophage inflammatory protein-2 (MIP-2), procalcitonin (PCT), and C-reactive protein (CRP) patterns in identifying bacterial infections during start of fever in normal and cyclophosphamide-treated (leukopenic) rats following an injection of lipopolysaccharide (LPS) or muramyl dipeptide (MDP) as a model for gram-negative and gram-positive bacterial infections. We found that, compared to normal rats, immunosuppressed animals exhibited significantly higher fevers and lesser production of all mediators, except IL-6, after toxin challenge. Moreover, compared to rats that received MDP, both groups of animals that received an equivalent dose of LPS showed significantly higher fevers and greater increase in serum cytokine levels. Furthermore, in contrast to those in immunocompetent rats, serum levels of IL-6 and MIP-2 were not significantly changed in leukopenic animals after MDP injection. Other serum markers such as PCT and CRP failed to discriminate between bacterial stimuli in both groups of animals. These results suggest that the use of the analyzed serum markers at an early stage of fever could give useful information for the clinician for excluding gram-negative from gram-positive infections.     

Reduced progression of atherosclerosis in apolipoprotein E-deficient mice treated with lacidipine is associated with a decreased susceptibility of low-density lipoprotein to oxidation

A study has been carried out in the apolipoprotein (apo) E-deficient mouse to investigate the activity of lacidipine (a calcium antagonist with antioxidant properties) in inhibiting the development of atherosclerotic lesions; of particular interest were changes in the susceptibility of low-density lipoproteins (LDL) to oxidation. Mice receiving a Western-type diet to accelerate the development of atherosclerosis were treated orally with vehicle or lacidipine at 3 or 10 mg/kg/day for 8 weeks. Lacidipine treatment (at 3 or 10 mg/kg) had no effect on the plasma lipid profile. However, a significant (P < 0.01) dose-related reduction of 43 and 50% of the aortic lesion area in respect to vehicle-treated mice was observed. Moreover, the resistance of mouse plasma LDL to undergo lipid peroxidation was significantly (P < 0.01) increased in apo E-deficient mice treated with lacidipine. The native LDL-like particle, derived from apo E-deficient mice treated with lacidipine, contained significantly lower concentrations of malonyldialdehyde than the vehicle-treated control group (P < 0.01). After exposure to human umbilical vein endothelial cells, LDL-like particle vitamin E levels (expressed as area under the curve; AUC), were significantly higher (P < 0.01) in both the 3 and 10 mg/kg lacidipine-treated groups, in comparison with the vehicle-treated control animals. We conclude that lacidipine reduced the extent of the atherosclerotic area in hypercholesterolaemic apo E-deficient mice, and that this reduction may be associated with the capacity of the drug to decrease the susceptibility of LDL to oxidation.     

Reduced folate carrier polymorphism (80A-->G) and neural tube defects

Transport of folates in mammalian cells occurs by a carrier-mediated mechanism. The human folate carrier (RFC-1) gene has been isolated and characterized. Within this gene, a common polymorphism, 80A-->G, changing a histidine to an arginine in exon 2 (H27R), was recently identified. Defects in folate metabolism, such as defective carrier molecules, could be implicated in the etiology of neural tube defects (NTDs). In the present case-control study, we recruited 174 Italian probands with nonsyndromic NTD, 43 mothers, 53 fathers and 156 control individuals and evaluated the impact of RFC-1 variant on NTD risk. A statistically significant risk was calculated for the 80GG genotype of the NTD cases (OR=2.35; 95% CI 1.21-4.58) and mothers (OR=2.74; 95% CI 0.92-8.38). On the contrary, the heterozygous genotype of the mothers and both heterozygous and homozygous genotypes of the fathers did not seem to be significant NTD risk factors. Furthemore, according to the multifactorial inheritance of NTDs, we demonstrated that the combined genotypes for MTHFR 1298A-->C and RFC-1 80A-->G polymorphisms of cases resulted in greater NTD risk than heterozygosity or homozygosity for RFC-1 80A-->G variant alone. Conversely, our data provide no evidence for an association between NTD phenotype and combined MTHFR C677T/RFC-1 A80G genotypes. Moreover, here we describe the combinations of the two MTHFR polymorphic sites (677CT and 1298AC) with RFC-1 genotypes. We found that both patients and controls could have at most quadruple-mutation combinations. Interestingly, 27% (7/26) of the mothers and 18.75% (30/160) of the cases genotyped presented four mutant alleles in comparison with 8.5% (11/129) of the controls. Finally, the frequency of NTD cases and mothers carrying combined heterozygosity for the two MTHFR polymorphisms and RFC-1 80GG homozygosity (677CT/1298AC/80GG) (cases=11.3%; mothers 11.5%) was increased compared with controls (1.6%). Altogether, our findings support the hypothesis that RFC-1 A80G variant may contribute to NTD susceptibility in the Italian population.     

ErbB2 and the antimetastatic nm23/NDP kinase in regulating serum induced breast cancer invasion

The erbB2 gene is often found amplified and/or overexpressed in breast cancer in which it has clinical relevance as prognostic and predictive factor. It is involved in growth regulation and has a role in the initial phases of cell proliferation, while in vivo and in vitro studies have suggested an involvement also in cell invasion and metastases. It is not clear if these two roles are mutually exclusive and little is known about the mechanisms by which erbB2 may be involved in the control of these processes. Our previous data on patient series suggested that erbB2 might be regulated in different ways depending on the neoplastic status of the cells and that it might be involved in different regulatory pathways. To test this hypothesis we have measured the serum-dependent regulation of erbB2 as a function of the expression of the antimetastatic gene, nm23, in a panel of breast cancer cell lines. The experimental model consisted of three cell lines having different proliferative and invasive potentials: a non-metastatic estrogen receptor (ER) positive cell line, MCF-7; a highly metastatic ER negative cell line, MDA-MB435; and the MDA-MB435 cell line transfected with the nm23-H1 antimetastatic gene (clone H1-177) which has lost the ability to invade and metastasize. We first analysed the serum concentration dependence of invasion and proliferation after 3-4 days of serum deprivation confirming the proliferative and invasive potential of the three cell lines. Modulation of erbB2 expression by different concentrations of serum was then studied. ErbB2 expression in MCF-7 cells showed a complex pattern due to serum modulation, whereas, it was not longer regulated by serum in the MDA-MB435 cell line. In H1-177 cells the erbB2 response to serum was restored and it was very similar to that observed in MCF-7. These data showed a tight association between nm23 and the regulation of erbB2 expression by serum factors suggesting that the role of erbB2 in invasion might be dependent on nm23 expression.     

Juvenile Idiopathic Arthritis

Overexpression of cytokines in inflamed joints plays an important role in joint inflammation and in damage to articular tissue. Biological agents aimed at specifically antagonising tumour necrosis factor (TNF) are effective in the treatment of adult rheumatoid arthritis. A recent trial of etanercept, a genetically engineered fusion protein consisting of the Fc domain of human IgG1 and the TNF receptor p75, has demonstrated that this agent is also well tolerated and effective in patients with juvenile idiopathic arthritis (JIA). Etanercept offers a promising new alternative for patients with JIA who have persistently active arthritis despite treatment with methotrexate. Further studies are needed to clarify whether etanercept is equally effective in the various onset types of JIA (oligoarthritis, polyarthritis and systemic arthritis), whether it can modify disease progression and whether it can be administered safely for long periods of time to children.     

Hepatic Function and Fibrinolysis in Patients with Hereditary Angioedema Undergoing Long-Term Treatment with Tranexamic Acid

Prophylactic treatment with antifibrinolytic agents, epsilon-aminocapriod and tranexamic acid, reduces the incidence and severits of attacks in patients with hereditary angioedema. Long-term ellectivenessor risk of antifibrinolytic agents has not been established. Sixteen patients needing continuous prophylaxis because of frequency and severity of attacks were treated with tranexamic acid. In four patients this treatment was ineffective and the drug was withdrawn after 2 months. A remission or reduction in the frequency or serverity of attacks was observed in 12 patients treated for a period ranging from 8 to 34 months. Hepatic tests and blood fibrinolytic activity were not influenced by long term oral treatment with tranexamic acid.     

Further Survey of Aflatoxin M1 in Milk Powders by ELISA

A survey of AFM₁ residues in 58 commercial milk powder samples was carried out using an enzyme‐linked immunosorbent assay (ELISA) based on a monoclonal antibody against aflatoxin M₁ (AFM₁). The samples were collected from the USA (10), China (28), Italy (14), New Zealand (3) and Poland (3). The ELISA was performed without the need for clean‐up procedures. The data revealed that 4 (US), 21 (Chinese) and 1 (Polish) samples were positive for AFM₁, with an average of 95.5, 102.8 and 85.0 pg g^‐1 of the AFM₁respectively.