Methylenetetrahydrofolate reductase gene C677T polymorphism,homocysteine, vitamin B12, and DNA damage in coronary artery disease

Elevated levels of plasma homocysteine (Hcy), a risk factor for coronary artery disease (CAD), can result from genetic errors, e.g., the methylenetetrahydrofolate reductase (MTHFR) polymorphism, or nutritional deficiencies, e.g., in vitamin B12 and folate. The mechanism by which Hcy induces atherosclerosis is not fully understood. Recently, Hcy has also been observed to induce DNA damage. In this study, we have investigated whether DNA damage is related to the C677T variant in the MTHFR gene and to plasma levels of Hcy, B12, and folate in patients with CAD. Patients ( n=46) with angiographically proven CAD were studied by using the micronucleus (MN) test, an accepted method for evaluating genetic instability. TT patients had plasma Hcy levels higher than those with the CT or CC genotypes (27.8+/-5.2 vs 13.7+/-2.2 and 12.9+/-1.9 micro mol/l, respectively; P=0.02). Patients with multi-vessel disease had higher plasma Hcy levels (11.6+/-1.2, 22.0+/-4.7, 19.3+/-3.9 micromol/l for one-, two- and three-vessel disease, respectively; P=0.05). The MN index increased with the number of affected vessels (8.4+/-0.7, 11.1+/-2.0, 14.2+/-1.7 for one-, two-, and three-vessels disease, respectively; P=0.02) and was significantly higher in subjects with the TT genotype compared with the CC or CT genotypes (15.7+/-2.4 vs 8.9+/-1.7 and 9.9+/-0.8; P=0.02). The MN index was also correlated negatively with plasma B12 concentration ( r=-0.343; P=0.019) and positively with plasma Hcy ( r=0.429, P=0.005). These data indicate that the MN index is associated with the severity of CAD and is related to the MTHFR polymorphism, suggesting an interesting link between coronary atherosclerosis and genetic instability in humans.     

Plasticity of influenza haemagglutinin fusion peptides and their interaction with lipid bilayers

A detailed molecular dynamics study of the haemagglutinin fusion peptide (N-terminal 20 residues of the HA2 subunits) in a model bilayer has yielded useful information about the molecular interactions leading to insertion into the lipids. Simulations were performed on the native sequence, as well as a number of mutant sequences, which are either fusogenic or nonfusogenic. For the native sequence and fusogenic mutants, the N-terminal 11 residues of the fusion peptides are helical and insert with a tilt angle of approximately 30 degrees with respect to the membrane normal, in very good agreement with experimental data. The tilted insertion of the native sequence peptide leads to membrane bilayer thinning and the calculated order parameters show larger disorder of the alkyl chains. These results indicate that the lipid packing is perturbed by the fusion peptide and could be used to explain membrane fusion. For the nonfusogenic sequences investigated, it was found that most of them equilibrate parallel to the interface plane and do not adopt a tilted conformation. The presence of a charged residue at the beginning of the sequence (G1E mutant) resulted in a more difficult case, and the outcomes do not fall straightforwardly into the general picture. Sequence searches have revealed similarities of the fusion peptide of influenza haemagglutinin with peptide sequences such as segments of porin, amyloid alpha eta peptide, and a peptide from the prion sequence. These results confirm that the sequence can adopt different folds in different environments. The plasticity and the conformational dependence on the local environment could be used to better understand the function of fusion peptides.     

Clinical Evaluation of Adriamycin,a New Antitumour Antibiotic

Adriamycin, a new antitumour antibiotic of the anthracycline group with a structural formula very similar to daunorubicin, has proved to have potent tumour-growth-inhibiting properties, and to be particularly effective in childhood malignancies. Though adriamycin produces a higher percentage of side-effects than daunorubicin—namely, stomatitis and alopecia—a lower dosage may be used for therapy.     

Bifid bacteria in bovine rumen

Summary About 500 bifid isolates from 150 samples of bovine rumen liquor were examined for their morphology, physiology and biochemistry. Diagnosis as bifid bacteria was based upon the peculiar pathway of glucose anaerobic metabolism i.e. the fructose-6-phosphate shunt. Four phenetic types were recognized. These types can be differentiated from those found in human habitats because their cell-free extracts are aldolase and HMP dehydrogenases positive: they are potential heterofermenters; furthermore the rumen types are nutritionally different. The distinction of the rumen bifids from the Bifidobacterium species of the intestine of Apis mellifica and Apis indica is still more consistent for a lot of characters. The characters of two rumen types warranted the creation of two new species of the genus Bifidobacterium. One of these, B. globosum n. sp., has a proper morphology, is serologically distinct and has a deoxyribonucleic acid base composition, in % GC, of 64.5. The other, B. ruminale n. sp., found so far only in rumen, is characteristically lactose non fermenter, at variance with all the bifids from human habitats and has peculiar morphological traits. A third type is probably a rough variant of B. ruminale and a fourth is serologically distinct and mannitol fermenter; their taxonomic definition is still, however, premature.This investigation was supported by a grant received from Consiglio Nazionale delle Ricerche (C.N.R.), Roma.     

Complexes of 2-thiophenecarbonyl and isonicotinoyl hydrazones of 3-(N-methyl)isatin. A study of their antimicrobial activity

Cobalt(II), nickel(II), copper(II) and zinc(II) complexes of 2-thiophenecarbonyl and isonicotinoyl hydrazones of 3-(N-methyl)isatin (HL(1) and HL(2), respectively) were synthesized and characterized, being the crystal structures of HL(1), HL(2) and [Ni(L(1))(2)].2CHCl(3) elucidated by X-ray diffraction techniques. The in vitro antimicrobial activity of all these compounds was tested against several bacteria and fungi. HL(1)and its complexes exhibited a strong inhibition of the growth of Haemophilus influenzae (MIC 0.15-1.50microg/mL) and good antibacterial properties towards Bacillus subtilis (MIC 3-25microg/mL). The minimal inhibitory concentration (MIC) was defined as the lowest concentration of compound inhibiting the growth of each strain. The antibacterial effectiveness was confirmed against a number of Gram positive bacteria, including methicillin-resistant Staphylococcus aureus. Yeasts and moulds showed a low susceptibility, except the dermatophyte mould Epidermophyton floccosum that is inhibited at concentrations ranging from 6 to 50microg/mL. In general, the antimicrobial activity of the thiophene derivatives was greater than that of the isonicotinic analogues.     

Design, synthesis, and biological evaluation of new (2E,6E)-10-(dimethylamino)-3,7-dimethyl-2,6-decadien-1-ol ethers as inhibitors of human and Trypanosoma cruzi oxidosqualene cyclase

New dimethylamino truncated squalene ether derivatives containing a different aromatic moiety (phenyl, naphthyl, and biphenyl) or a simple alkyl (n-hexylic) group were synthesized as inhibitors of the oxidosqualene cyclase (OSC) and of the sterol biosynthetic pathway. The activity against human OSC was compared with the activity against the OSCs of pathogenic organisms such as Pneumocystis carinii and Trypanosoma cruzi. The phenyl derivative was the most potent inhibitor of T. cruzi OSC.     

Role of DAMPs and of Leukocytes Infiltration in Ischemic Stroke: Insights from Animal Models and Translation to the Human Disease

Stroke is a leading cause of death and disability worldwide. Several mechanisms are involved in the pathogenesis of ischemic stroke (IS). The contributory role of the inflammatory and immunity processes was demonstrated both in vitro and in animal models, and was confirmed in humans. IS evokes an immediate inflammatory response that involves complex cellular and molecular mechanisms. All components of the innate and adaptive immunity systems are involved in several steps of the ischemic cascade. In the early phase, inflammatory and immune mechanisms contribute to the brain tissue damage, whereas, in the late phase, they participate to the tissue repair processes. In particular, damage-associated molecular patterns (DAMPs) appear critical for the promotion of altered blood brain barrier permeability, leukocytes infiltration, tissue edema and brain injury. Conversely, the activation of regulatory T lymphocytes (Tregs) plays protective effects. The identification of specific cellular/molecular elements belonging to the inflammatory and immune responses, contributing to the brain ischemic injury and tissue remodeling, offers the advantage to design adequate therapeutic strategies. In this article, we will present an overview of the knowledge on inflammatory and immunity processes in IS, with a particular focus on the role of DAMPs and leukocytes infiltration. We will discuss evidence obtained in preclinical models of IS and in humans. The main molecular mechanisms useful for the development of novel therapeutic approaches will be highlighted. The translation of experimental findings to the human disease is still a difficult step to pursue. Further investigations are required to fill up the existing gaps.

     

15-Hydroxyprostaglandin Dehydrogenase Generation of Electrophilic Lipid Signaling Mediators from Hydroxy Ω-3 Fatty Acids

15-Hydroxyprostaglandin dehydrogenase (15PGDH) is the primary enzyme catalyzing the conversion of hydroxylated arachidonic acid species to their corresponding oxidized metabolites. The oxidation of hydroxylated fatty acids, such as the conversion of prostaglandin (PG) E₂ to 15-ketoPGE₂, by 15PGDH is viewed to inactivate signaling responses. In contrast, the typically electrophilic products can also induce anti-inflammatory and anti-proliferative responses. This study determined that hydroxylated docosahexaenoic acid metabolites (HDoHEs) are substrates for 15PGDH. Examination of 15PGDH substrate specificity was conducted in cell culture (A549 and primary human airway epithelia and alveolar macrophages) using chemical inhibition and shRNA knockdown of 15PGDH. Substrate specificity is broad and relies on the carbon position of the acyl chain hydroxyl group. 14-HDoHE was determined to be the optimal DHA substrate for 15PGDH, resulting in the formation of its electrophilic metabolite, 14-oxoDHA. Consistent with this, 14-HDoHE was detected in bronchoalveolar lavage cells of mild to moderate asthmatics, and the exogenous addition of 14-oxoDHA to primary alveolar macrophages inhibited LPS-induced proinflammatory cytokine mRNA expression. These data reveal that 15PGDH-derived DHA metabolites are biologically active and can contribute to the salutary signaling actions of Ω-3 fatty acids.     

D-Asp: a new player in reproductive endocrinology of the amphibian Rana esculenta

We investigated the involvement of D-Aspartic acid (D-Asp) on ovarian and testicular morphology of the green frog, Rana esculenta, and its effect on the testosterone production. The study has been performed throughout the reproductive cycle. In both ovary and testis a substantial amount of D-Asp is endogenously present and its concentration varies as function of reproduction. In the frog, D-Asp content is differently correlated with gonadal and plasmatic levels of testosterone, depending on the sex. In fact, the amount of the D-Asp is inversely linked with that of the testosterone in the ovary, while this correlation directly matched in the testis. In vivo short-term experiments, consisting of a single intra-peritoneal injection of D-Asp (2.0 μmol/g body weight), demonstrated that the enantiomer is significantly accumulated by both the ovary and testis, reaching after 3 h the highest uptake and thereafter decreasing to baseline values within 24 h. Furthermore, D-Asp influences the synthesis and/or the release of testosterone, causing a decrease of its level in the female, and an increase in the male, respectively. In vivo long-term experiments, D-Asp, chronically administered to the frogs of both sexes, enhances the maturation of both gonads, determining in the oocytes an higher accumulation of carbohydrate yolk plates in the ooplasm, and stimulating the spermatogenesis in the testis. Taken altogether, our results show that D-Asp operates differently in female and male frog gonads, indicating that it has different targets in the reproductive machinery depending on the sex.