Epstein-Barr virus transformation of human B lymphocytes despite inhibition of viral polymerase.

Epstein-Barr virus transformed human lymphocytes despite the presence of up to 500 microM acyclovir [9-(2-hydroxyethoxymethyl)guanine], a viral DNA polymerase inhibitor. The transformed cells contained multiple Epstein-Barr virus genome copy numbers. Functional viral DNA polymerase is probably not required for cell transformation and the initial amplification of the viral genome.     

Dimer–monomer equilibrium of human thymidylate synthase monitored by fluorescence resonance energy transfer

An ad hoc bioconjugation/fluorescence resonance energy transfer (FRET) assay has been designed to spectroscopically monitor the quaternary state of human thymidylate synthase dimeric protein. The approach enables the chemoselective engineering of allosteric residues while preserving the native protein functions through reversible masking of residues within the catalytic site, and is therefore suitable for activity/oligomerization dual assay screenings. It is applied to tag the two subunits of human thymidylate synthase at cysteines 43 and 43′ with an excitation energy donor/acceptor pair. The dimer–monomer equilibrium of the enzyme is then characterized through steady‐state fluorescence determination of the intersubunit resonance energy transfer efficiency.     

Body Mass Index and Serum Proteomic Profile in Breast Cancer and Healthy Women: A Prospective Study

Epidemiological studies suggest a possible association between BMI, diagnosis and clinical-pathological breast cancer characteristics but biological bases for this relationship still remain to be ascertained. Several biological mechanisms play a role in the genesis and progression of breast cancer. This study aimed to investigate relationships between BMI and breast cancer diagnosis/progression in a Southern Italian population and to try to interpret results according to the serum proteomic profile of healthy and breast cancer patients.BMI, presence or absence of breast cancer and its clinical-pathological characteristics were analyzed in a series of 300 breast cancer women and compared with those of 300 healthy women prospectively. To investigate whether obesity is associated with alterations in serum protein profile, SELDI-ToF approach was applied.Alcohol consumption (22.7% vs 11.3%; p<0.001) and postmenopausal status (65.7% vs 52%; p<0.001) but not BMI resulted significantly different in patients vs controls. Conversely, BMI was significantly associated with a larger-tumour size (BMI> = 30 respect to normal weight: OR = 2.49, 95% CI 1.25–4.99, p = 0.0098) and a higher probability of having positive axillary lymph node (OR = 3.67, CI 95% 2.16–6.23, p<0.0001). Multivariate analysis confirmed the association of breast cancer diagnosis with alcohol consumption (OR = 2.28;CI 1.36–3.83; p<0.0018). Serum protein profile revealed the presence of significant (p-value <0,01) differentially expressed peaks m/z 6934, m/z 5066 in high BMI breast cancer patients vs healthy subjects and m/z 6934, m/z 3346 in high vs low BMI breast cancer patients.The analysis of pathological features of cancer indicates that normal weight women have a significantly higher probability of having a smaller breast cancer at time of diagnosis and negative axillary lymph nodes while increased BMI is associated with an altered protein profile in breast cancer patients. Further studies to identify specific proteins found in the serum and their role in breast cancerogenesis and progression are in progress.     

Synthesis of novel nitric oxide (NO)-releasing esters of timolol

A novel class of timolol derivatives with nitric oxide (NO)-donating moieties achieved chemical stability yet under physiologically relevant conditions released timolol and NO. Hindered esters A were designed and synthesized, whose ‘triggered’ release relied on enzymatic hydrolysis of the nitrate ester in A to B, that in turn cyclized to liberate timolol.     

Synthesis and structure–activity studies of novel homomorpholine oxazolidinone antibacterial agents

A novel series of oxazolidinones were synthesized in which the morpholine C-ring of linezolid was replaced with homomorpholine. In addition to investigating the effect of a homomorpholine C-ring on antibacterial activity, the effect of des-, mono-, di-, and tri-fluoro substitution on the phenyl B-ring was investigated as well. Various C-5 functional groups were also examined, including acetamides and triazoles and carboxamides.     

Development of the digestive system of Argentine hake,Merluccius hubbsi,larvae

The Argentine hake Merluccius hubbsi is an important fishery resource of the Southwestern Atlantic Ocean and it is also a potential species for cultivation. In this work, the digestive system development in field-caught hake larvae was studied using histological and histochemical approaches. The digestive tract of larvae was divided into: oropharyngeal cavity (OPC), esophagus, stomach (that develops in the preflexion stage), and intestine. The annexed digestive glands consisted of the liver and the exocrine pancreas. At the beginning of the preflexion stage, teeth were developed in the OPC. There were mucous cells in the esophagus secreting different glycoconjugates from hatching. The enterocytes in the posterior intestine exhibited supranuclear vesicles associated with protein absorption. Mucous cells were observed in the posterior intestine in the preflexion stage and, in the anterior region, ending the flexion stage. Each type of glycoconjugates has a specific role. Acidic mucins lubricate and protect from mechanical damage, sialomucines protect from bacterial infections and neutral mucins regulate the acidity of mucus secretion, protect against abrasion and participate in the formation of the chyme, indicating a pregastric digestion. The liver was present since hatching with pancreatic tissue inside and increased in size acquiring the typical structure with hepatocyte cords, sinusoids, vacuoles, and hepatic duct. The hepatocytes vacuolization increased with larval development. The pancreas became extra-hepatic, with basophilic acinar cells and acidophilic zymogen granules. Throughout the ontogeny, the increased structural and functional complexity of the digestive system reflected the transition to exogenous feeding and nutritional increasing needs.     

Interactions of phospholipid vesicles with murine lymphocytes. II. Correlation between altered surface properties and enhanced proliferative response.

The effect of unilamellar lipid vesicles composed of dioleoyl lecithin (DOL), egg yolk lecithin (EYL), 1:1 EYL:cholesterol (Chol), dipalmitoyl lecithin (DPL), and dimyristoyl lecithin (DML) on the mitogenic response in mouse lymphocytes was tested. Cortisone-resistant thymocytes were briefly treated with lipid vesicles and subsequently stimulated with concanavalin A (con A). All of the lipid vesicles induced an enhanced mitogenic response on day 3 as tested by [3H]TdR incorporation and by counting total cells. The order of enchanced [3H]TdR incorporation (less than or equal to 5.3 times the control) was DML greater than DPL greater than 1:1 EYL:Chol greater than EYL congruent to DOL greater than untreated control cells. These increases were paralleled by increased numbers of total cells. The response of spleen cells to a B-cell mitogen, bacterial lipopolysaccharide, was similarly enhanced by vesicle pretreatments in the same order. Vesicle treatments alone were not mitogenic Pretreatment of cells with lipid vesicles modified lectin binding: DML and DPL increased the binding of [125I]con A by three to four times the control, whereas 1:1 EYL:Chol, EYL, or DOL had little or no effect. The binding of [125I]phytohemagglutinin-P (PHA-P) to vesicle-treated cells was indistinguishable from untreated cells. The lectin (con A; PHA-P)-induced agglutination of vesicle-treated cells was also modified by different lipid vesicles in the same order as the mitogenic response. Based on the results presented in the accompanying report [6], we find that the cell surface adsorption properties of the applied lipid vesicles correlate with their ability to enhance the mitogenic response, and that they modify agglutinability and lectin binding. These results are further discussed in terms of the possible alteration of membrane properties and subsequent cellular activity.