Delayed angiogenesis in aging rats and therapeutic effect of adenoviral gene transfer of VEGF

We have studied an age-related impairment in angiogenesis and evaluated the effect of overexpressing VEGF in this situation. Polyvinyl alcohol sponges were implanted subcutaneously into aged (24-month), adult (12-month), and young (2-month) rats. Blood vessel ingrowth and proliferative activity in the sponges were assessed by histology with immunostaining for von Willebrand's factor and proliferating cell nuclear antigen (PCNA), respectively. The percentage of total sponge area filled with ingrowing fibrovascular tissue was minimal in aged rats, intermediate in adult rats and highest in young rats. A similar pattern was observed for the total blood vessel numbers in the sponges from old to young animals. The percentage of total sponge endothelial cells (ECs) showing proliferative activity (PCNA positive) was lowest in the aged animals, intermediate in the adult rats and highest in the young rats. To further explore the mechanism of impaired angiogenesis in aged animals, we investigated and found a reduced level of endogenous VEGF protein expression in 12-month-old rats compared to that in 2-month-old rats. VEGF121 gene transfer significantly enhanced blood vessel and fibrovascular tissue ingrowth in adult/aged rats. Adenoviral-VEGF gene transfer also significantly stimulated EC proliferation in aged and adult rats. However, identical treatment failed to further stimulate the already more robust angiogenesis in young animals. The different angiogenic response in adult vs. young rats was not due to differences in gene transfer efficiency, since similar levels of human VEGF121 protein was detected in adult and young rats. Our results indicate that the decreased angiogenic response with aging is associated with reduced EC proliferation and reduced endogenous VEGF production. Adenoviral-VEGF121 gene transfer is effective in augmenting angiogenesis, particularly in older animals.     

CD59 blocks not only the insertion of C9 into MAC but inhibits ion channel formation by homologous C5b-8 as well as C5b-9

Activation of the complement system on the cell surface results in the insertion of pore forming membrane attack complexes (MAC, C5b-9). In order to protect themselves from the complement attack, the cells express several regulatory molecules, including the terminal complex regulator CD59 that inhibits assembly of the large MACs by inhibiting the insertion of additional C9 molecules into the C5b-9 complex. Using the whole cell patch clamp method, we were able to measure accumulation of homologous MACs in the membrane of CD59⁻ human B-cells, which formed non-selective ion channels with a total conductance of 360 ± 24 pS as measured at the beginning of the steady-state phase of the inward currents. C5b-8 and small-size MAC (MAC containing only a single C9) can also form ion channels. Nevertheless, in CD59⁺ human B-cells in spite of small-size MAC formation, an ion current could not be detected. In addition, restoring CD59 to the membrane of the CD59⁻ cells inhibited the serum-evoked inward current. The ion channels formed by the small-size MAC were therefore sealed, indicating that CD59 directly interfered with the pore formation of C5b-8 as well as that of small-size C5b-9. These results offer an explanation as to why CD59-expressing cells are not leaky in spite of a buildup of homologous C5b-8 and small-size MAC. Our experiments also confirmed that ion channel inhibition by CD59 is subject to homologous restriction and that CD59 cannot block the conductivity of MAC when generated by xenogenic (rabbit) serum.     

Lymphopineal tissue in the chicken

We have studied the chicken's pineal gland by light and electron microscopy at 3 and 4 weeks of age. The results indicated that lymphocytes, plasma cells, secretory cells, basophil and eosinophil granulocytes enter the parenchyma and a new histologically defined tissue is formed which we call lymphopineal tissue. Inside the pineal parenchyma, the number of thymidine labeled cells is almost three times higher than in the interstitium suggesting that the pineal's products might be blastogenic for the cells and/or exert an influence on post-thymic T-cell differentiation.     

High sensitivity to autoxidation in neonatal calf erythrocytes: possible mechanism of accelerated cell aging

The suspension viscosity, formation of methaemoglobin and production of malondialdehyde (MDA) associated with the non-enzymatic oxidation of polyunsaturated fatty acids during auto-oxidation conditions in vitro have been compared in erythrocytes from young calves (2, 4 and 6 weeks of age) and mature cattle. The autoxidation conditions were designed to simulate the oxidative stress to which neonatal erythrocytes are exposed in vivo. Characterisation of lipid peroxidation was also undertaken by a combination of lipid fluorescent measurements and quantification of the superoxide dismutase (SOD) activities of the erythrocytes. The results demonstrated that high SOD activities in the erythrocytes of the neonatal calf was insufficient to afford protection against the increased autoxidation of haemoglobin and subsequent accumulation of lipid peroxidation products. High levels of methaemoglobin formation and lipid peroxidation were able to provide an explanation for an observed reduction in rheological adaptability (increased suspension viscosity) and an accelerated aging of the neonatal cells under in vivo conditions.     

Cross-Sectional Associations between Mothers and Children’s Breakfast Routine—The Feel4Diabetes-Study

Positive influences of family members have been associated with a high probability of children’s daily breakfast consumption. Therefore, the aim of this study was to scrutinize the association of breakfast routines between mothers and their children. The baseline data of the Feel4Diabetes-study was obtained in 9760 children (49.05% boys)–mother pairs in six European countries. A parental self-reported questionnaire gauging the frequency of breakfast consumption and of breakfast´ foods and beverages consumption was used. Agreement in routines of mothers and their children’s breakfast consumption was analyzed in sex-specific crosstabs. The relationship of breakfast routine and food groups’ consumption between mothers and their children was assessed with analysis of covariance. The highest proportion of children who always consumed breakfast were those whose mothers always consumed it. Children consuming breakfast regularly had a higher intake of milk or unsweetened dairy products and all kind of cereal products (low fiber and whole-grain) than occasional breakfast consumers (p < 0.05). The strong similarity between mothers and children suggests a transfer of breakfast routine from mothers to their children, as a high proportion of children who usually consume breakfast were from mothers also consuming breakfast. All breakfast foods and beverages consumption frequencies were similar between children and their mothers.     

Whole-body autoradiography and quantitative organ-level distribution study of deramciclane in rats

The distribution of 3H-labelled deramciclane (EGIS-3886), a new 5-HT2 antagonist with anxiolytic activity, has been investigated by whole-body autoradiography and quantitative organ-level determination after intravenous and oral administration to male and female rats at a dose of 3 mg kg(-1). Pregnant dams were also studied, but by autoradiography only. In the autoradiographic study 32 organs were investigated, while in the quantitative organ-level study the radioactivity in 15 organs were determined. There are no sex differences in the distribution of deramciclane, absorption is rapid, elimination is comparatively fast, no specific organ is targeted, and the accumulation of the compound is very unlikely. Penetration of the blood-brain barrier was complete and extremely fast, a very important feature of a potential anxiolytic drug. There is no penetration of the foetus in pregnant dams. The study demonstrated that deramciclane has advantageous pharmacokinetic properties in rats.     

Influence of food on the oral bioavailability of deramciclane from film-coated tablet in healthy male volunteers.

The effect of a high-fat meal on the oral bioavailability of deramciclane 30 mg tablet was evaluated in 18 healthy male volunteers in a randomised, single dose, two-way crossover study. The drug was administered following an overnight fast or a standardised high-fat breakfast. The plasma concentrations of deramciclane and N-desmethylderamciclane were determined by using a validated HPLC-MS -MS/MS method. An effect of food on the bioavailability was indicated if the 90% confidence interval (CI) for the ratio of geometric means of fed and fasted treatments was not contained in the equivalence limit of 0.8-1.25 for AUC and C(max). The ratios of the mean C(max) and AUC(0-infinity) values of deramciclane were 1.24 (90% CI 1.12-1.38) and 1.31 (90% CI 1.21-1.41) in fed versus fasted subjects, which overlapped but exceeded the equivalence limit. In contrast to the parent compound, the 90% CI of the mean ratios for AUC(0-infinity) and C(max) of N-desmethylderamciclane were within the predefined range. The 24 and 31% increase in C(max) and AUC(0-infinity) of deramciclane, respectively, under fed condition is modest and probably has no clinical significance since it is relatively small compared to the inter-individual variability of these parameters.     

Liposomes for Topical Use: A Physico-Chemical Comparison of Vesicles Prepared from Egg or Soy Lecithin

Developments in nanotechnology and in the formulation of liposomal systems provide the opportunity for cosmetic dermatology to design novel delivery systems. Determination of their physico-chemical parameters has importance when developing a nano-delivery system. The present study highlights some technological aspects/characteristics of liposomes formulated from egg or soy lecithins for topical use. Alterations in the pH, viscosity, surface tension, and microscopic/macroscopic appearance of these vesicular systems were investigated. The chemical composition of the two types of lecithin was checked by mass spectrometry. Caffeine, as a model molecule, was encapsulated into multilamellar vesicles prepared from the two types of lecithin: then zeta potential, membrane fluidity, and encapsulation efficiency were compared. According to our observations, samples prepared from the two lecithins altered the pH in opposite directions: egg lecithin increased it while soy lecithin decreased it with increased lipid concentration. Our EPR spectroscopic results showed that the binding of caffeine did not change the membrane fluidity in the temperature range of possible topical use (measured between 2 and 50 °C). Combining our results on encapsulation efficiency for caffeine (about 30% for both lecithins) with those on membrane fluidity data, we concluded that the interaction of caffeine with the liposomal membrane does not change the rotational motion of the lipid molecules close to the head group region. In conclusion, topical use of egg lecithin for liposomal formulations can be preferred if there are no differences in the physico-chemical properties due to the encapsulated drugs, because the physiological effects of egg lecithin vesicles on skin are significantly better than that of soy lecithin liposomes.