Sodium oleate induced rapid gelation of silk fibroin

Silk fibroin has acquired increasing interest in the last years for application in medicine and namely in tissue engineering. Several methods have been developed to process fibroin and for the fabrication of nets, sponges, films and gels. This paper deals with the fabrication and characterization of fibroin hydrogels obtained by using sodium oleate as gelation agent. Gels have been prepared by mixing Silk fibroin (SF) and Sodium oleate (SO) water solutions in different concentrations, and a quite wide frame of compositions have been explored. Rheological tests have been performed to determine the gelation times, scanning electron microscopies have been made to evaluate morphologies, FTIR analysis has been done to determine the conformation of the starting materials and of the resulting gels, water content has been measured and cytotoxicity tests have been performed to validate the potential biomedical use of the hydrogels. Depending on the SF and SO different gelation times have been obtained thanks to the formation of intermolecular bonds between the fibroin chains. The obtained fastest gelation of about 80 s could make this specific formulation compatible with in situ gelation. By changing composition, gels with different morphologies, rheological properties and water contents have been prepared.     

Phosphorus Solubilization and Plant Growth Promotion Ability of Rhizobacteria of <Emphasis Type="Italic">R. communis</Emphasis> L Growing in Assam,India

Castor (Ricinus communis L) is the primary host plant of eri silkworm and its rhizosphere harbours diverse group of microbial community with biofertilizer potentiality. Phosphate solubilizing bacteria (PSB) render available phosphate (P) in agricultural soil by P mineralization process through enzyme mediated reaction. In search for PSB strains, 15 castor rhizobacteria were isolated and characterized for morphological and biochemical properties. The isolates were screened in vitro for P solubilization efficiency both qualitatively and quantitatively. Isolate MAJ PSB12 produced highest soluble P concentration (322.20 µmol/l) in National Botanical Research Institute Phosphate medium after 96 h of incubation with a maximum drop in pH to 5.4 from 7.0. Among the isolates, maximum content of IAA (24.6 mg/l) and GA₃ (3.921 mg/l) was also found to be produced by the same strain. The most potential isolate was identified as Bacillus firmus MAJ PSB12 by 16S rRNA gene homology analysis and the sequence was submitted to National Centre for Biotechnology Information GenBank. Although many species belonging to the genus Bacillus are efficient P solubilizer, application of native rhizobacteria is easier for adaptation and succession during biofertilization process. B. firmus MAJ PSB12 can be utilized as potential biofertilizer to promote sustainable castor cultivation in sericulture for upliftment of rural livelihood.     

Physical activity and healthy eating in Brazilian students: a review of intervention programs

This article provides a systematic literature review on physical activity and/or healthy eating interventions among Brazilian students. Complete articles published from 2004 to 2009 were searched in the SciELO, MEDLINE, and CAPES electronic databases, in the articles' references, and through contacts with authors. Six studies covered nutritional interventions, another six analyzed nutrition and physical activity, and one discussed changes in body composition. Interventions produced different results according to their objectives: increase in weekly physical activity; improvement in eating habits and knowledge on nutrition; and decrease in overweight and obesity. School health promotion programs are essential for raising awareness on the relevance of health promotion and the adoption of healthy habits. However, further longitudinal studies are needed to produce evidence on sustainability of programs and healthy habits.     

Complexity of retinal cone bipolar cells

An open issue of retinal organization and function is the comprehension of the different tasks specifically performed by bipolar cells, the neurons that collect information from photoreceptors in the outer retina and convey the signal to the inner plexiform layer. Particularly interesting is to understand the unique contribution to the visual signal brought by cone bipolar cells, neurons typical of the mammalian retina and especially dedicated to receive synaptic input from cones. In all the species studied so far, it has been shown that cone bipolar cells occur in about ten different types, which form distinct clusters identified with a panel of both classical and modern genetic methods.Reviewed here is current literature illustrating the occurrence of morphological, molecular and architectural features that confer to each bipolar cell type exclusive fingerprints, ultimately predicting the emergence of similarly unique, albeit still partially unraveled, functional properties. Thus, differences among cone bipolar cells lay the ground for the genesis in the outer retina of parallel channels, which convey to the inner retina separate information, among others, about contrast, chromatic features and temporal properties of the visual signal.     

经食管超声心动图在复杂性先天性心脏病Fontan术中的应用

应用双平面经食管小儿探头对13例患复杂性先天性心脏病儿童，于Fontan术中连续监测。提供了高清晰的二维及彩色多普勒血流图，右房一肺动脉连接的内径0.5～1.0cm与外科手术中直接测量结果基本一致，脉冲多普勒提供术中Fontan连接内血流信息，前向性血流平均峰值速度57±26cm／sec，逆向血流平均峰值速度43±25cm／sec。经胃扫查显示下腔簿脉至肺动脉隔的全貌。2例再手术患者均基于术中超声立即发现的异常;1例为过长的隔引起左房流出道阻塞，另1例为房间隔小孔过小。本文表明经食管超声心动图（TEE）是小儿Fontan术中、术后的重要诊断与监视技术。     

Undersized dendritic arborizations in retinal ganglion cells of the rd1 mutant mouse: a paradigm of early onset photoreceptor degeneration

Retinitis pigmentosa (RP) is a family of inherited diseases causing progressive photoreceptor death. Retinal ganglion cells (RGCs) form the biological substrate for various therapeutic approaches designed to restore vision in RP individuals. Assessment of survival and preservation of RGCs in animal paradigms mimicking the human disease is of key importance for appropriate implementation of vision repair strategies. Here we studied the survival of RGCs in the rd1 mutant mouse, a known model of early onset, autosomic recessive RP, at various stages of photoreceptor degeneration. Furthermore, we analyzed the morphology of various types of RGCs using the newly generated transgenic mouse rd1/Thy1-GFP, in which the rd1 mutation is associated with green fluorescent protein (GFP) expression in a small population of different RGCs. We found excellent survival of cells at up to 1 year of age, a time at which the inner retina is known to have severely reorganized and partially degenerated. However, 50% of the cells analyzed within all RGC types exhibit an undersized dendritic tree, spanning about half of the normal area. Undersized cells are found both in adult and in very young (1-month-old) mice. This suggests that their aberrant phenotype is due to incomplete dendritic development, possibly as a consequence of altered visual input at the time of dendritic arbor refinement. These data show the importance of the timing of photoreceptor death in RGC dendritic development.     

The presence of retinopathy in patients with secondary diabetes following pancreatectomy or chronic pancreatitis

The incidence of diabetic retinopathy was evaluated by means of fluorescein angiography in 54 patients with diabetes secondary to chronic pancreatitis or to pancreatectomy. Thirty-one percent of the patients had background retinopathy; none had proliferative retinopathy. The percentage of patients with retinopathy was the same in groups with or without a family history of diabetes. There was no correlation between the degree of metabolic control, the levels of C-peptide, glucagon, growth hormone, and the presence of retinopathy. Retinopathy was correlated with the duration of diabetes. In conclusion, diabetes caused by pancreatitis or pancreatectomy has a significant prevalence of retinopathy, which has more benign characteristics and slower evolution than the retinopathy in patients with primary diabetes.     

Glucagon levels and ketogenesis in human diabetes following total or partial pancreatectomy and severe chronic pancreatitis

Summary In three groups of patients with insulin-dependent diabetes following total (n=5) or partial (n=5) pancreatectomy or chronic pancreatitis (n=7) and in a group of idiopathic diabetics, ketogenic capacity following insulin withdrawal and during a 24-h fast was studied. Basal glucagon values were significantly increased in all diabetic groups with no significant intergroup differences. Basal ketone body values and their increase during starvation and insulin withdrawal were high and not different in totally pancreatectomized and primary diabetics, both showing unmeasurable C-peptide levels. On the contrary, ketogenesis was reduced in partially pancreatectomized and in pancreatitis diabetics with persistent levels of C-peptide. Our data confirmed the persistence of immunoreactive glucagon after pancreatectomy and demonstrated that ketogenesis is not suppressed in pancreatectomized diabetics and depends above all on residual B-cell function. A possible ketogenic effect of extra-pancreatic glucagon-like substances cannot be excluded.