Local cholesterol metabolism orchestrates remyelination

Cholesterol is an essential component of all cell membranes and particularly enriched in myelin membranes. Myelin membranes are a major target of immune attacks in the chronic neurological disorder multiple sclerosis (MS). During demye- linating insults, cholesterol is released from damaged myelin, increasing local levels of this unique lipid and impeding tissue regeneration. Here, we summarize the current knowledge of cholesterol-dependent processes during demyelination and remyelination, emphasizing cell type-specific responses. We discuss cellular lipid/ cholesterol metabolism during early and late disease phases and highlight the con- cept of lipid-based pharmacological interventions. We propose that knowledge of the interplay between cell type-specific cholesterol handling, inflammation, and blood–brain barrier (BBB) integrity will unravel disease processes and facilitate development of strategies for therapies to promote remyelination

Scaling up the provision of family planning messages in antenatal and postpartum services in Upper Egypt

An operations research study by the Population Council’s FRONTIERS program in 20 facilities in Upper Egypt showed that integration of birth spacing messages into antenatal and postpartum care was feasible, acceptable to women and their husbands, and was associated with increased postpartum contraception. This report describes the initial and scale-up phases, their outcomes, challenges, and recommendations for improvement. In addition to successfully scaling up the program, the main achievement was securing the support and investment of senior MoHP officials at the central level, as well as the support and commitment of managers and supervisors at governorate and district levels. The report recommends more assistance to help MoHP adopt and integrate healthy timing and spacing of pregnancy messages in different programs

Inducible targeting of CNS astrocytes in Aldh1/1-CreERT2 BAC transgenic mice

Background: Studying astrocytes in higher brain functions has been hampered by the lack of genetic tools for the efficient expression of inducible Cre recombinase throughout the CNS, including the neocortex. Methods: Therefore, we generated BAC transgenic mice, in which CreERT2 is expressed under control of the Aldh1l1 regulatory region. Results: When crossbred to Cre reporter mice, adult Aldh1l1-CreERT2 mice show efficient gene targeting in astrocytes. No such Cre-mediated recombination was detectable in CNS neurons, oligodendrocytes, and microglia. As expected, Aldh1l1-CreERT2 expression was evident in several peripheral organs, including liver and kidney. Conclusions: Taken together, Aldh1l1-CreERT2 mice are a useful tool for studying astrocytes in neurovascular coupling, brain metabolism, synaptic plasticity and other aspects of neuron-glia interactions

Breaking the silence: Learning about youth sexual and reproductive health in Egypt

This collection of research (supported by the Ford Foundation office in Cairo) documents the Population Council’s efforts to build the capacity of young Egyptian researchers to study youth sexual and reproductive health. Understanding the needs of young Egyptians, including their sexual and reproductive health needs, is crucial for developing policies and programs that can help bring about desired changes and improve their health and well-being. Young people must be given accurate information and access to services to protect their sexual and reproductive health and to prepare them for taking on family responsibilities as they get older. This report sets the stage for the enormous work ahead in meeting young people’s needs for reliable sexual and reproductive health information and youth-friendly health services. It aims to shed light on these intimate and sensitive topics, encourage scientific debates, and highlight means of improving the sexual and reproductive health of young people in Egypt

Breaking the silence: Learning about youth sexual and reproductive health in Egypt [Arabic]

This collection of research (supported by the Ford Foundation office in Cairo) documents the Population Council’s efforts to build the capacity of young Egyptian researchers to study youth sexual and reproductive health. Understanding the needs of young Egyptians, including their sexual and reproductive health needs, is crucial for developing policies and programs that can help bring about desired changes and improve their health and well-being. Young people must be given accurate information and access to services to protect their sexual and reproductive health and to prepare them for taking on family responsibilities as they get older. This report sets the stage for the enormous work ahead in meeting young people’s needs for reliable sexual and reproductive health information and youth-friendly health services. It aims to shed light on these intimate and sensitive topics, encourage scientific debates, and highlight means of improving the sexual and reproductive health of young people in Egypt

Understanding HIV-related vulnerabilities and stigma among Egyptian youth

The overall objective of this study is to provide an evidence-based description and interpretation of the HIV-related risks and vulnerabilities faced by different subgroups of youth in Egypt. The report is part of a six-country study that was conducted by the Population Council in Egypt, Kenya, Nigeria, Senegal, South Africa, and Uganda. The study examines social, economic, cultural, and legal factors that may contribute to youth’s increased vulnerability to HIV and documents the situation of the policy and programmatic responses. The study identified poverty, unemployment, delayed marriage, and gender inequality as examples of factors that increase young people’s risk-taking behavior and hence vulnerability to HIV. The report concludes with a number of policy recommendations to help confront challenges due to dwindling funds, conservative social norms, discriminating laws and policies, under-utilization of services, and lack of coordination among various stakeholders

Efficacy of mannan-oligosaccharide and live yeast feed additives on performance, rumen morphology, serum biochemical parameters and muscle morphometric characteristics in buffalo calves

The objective of the current study was to assess the effect of dietary supplementations of mannan-oligosaccharide, live yeast, and a combination of these two additives on growth performance, histo-morphology of the rumen, and muscle morphometric attributes in buffalo calves. A total of twenty buffalo calves (average weight of 25 kg) having 3 months of age were distributed according to a complete randomized design. All animals were individually stalled in the shed and were fed ad-libitum. Experimental animals were divided into four groups for 67 days: Control group(without the inclusion of dietary supplementation); MOS group (Mannan oligosaccharide 5 g/clave/day; Yeast group (Live yeast 2g/calve/day) and Mixed group (MOS + Live Yeast 2.5g + 1g )/calve/day. Experimental results revealed that combined supplementation of MOS and Yeast and MOS alone resulted in an increased number of short-chain fatty acids in the rumen as well as ruminal pH (P<0.05). Results showed a significant improvement in average daily gain and FCR of MOS and Mixed supplemented groups (P<0.05). Histomorphological evaluation of rumen mucosal epithelium showed a significant improvement in the mixed-supplemented group (P<0.05) as compared to the yeast-supplemented and control groups. Muscle quality parameters such as meat texture showed significant improvement in MOS and mix-supplemented groups. Histological examination of longissimus dorsi muscle cross-section showed a significantly higher(P<0.05) muscle fiber and muscle fascicle diameter in both MOS and mix-supplemented calves groups. In conclusion, the results of this experiment revealed that the dietary addition of MOS, Live yeast, and their combination have positive effects on growth performance, rumen histology indices, and muscle morphometric features in buffalo calves.Comment: Pages 13, 4 figure

"Level Curvature" Distribution for Diffusive Aharonov-Bohm Systems: analytical results

We calculate analytically the distributions of "level curvatures" (LC) (the second derivatives of eigenvalues with respect to a magnetic flux) for a particle moving in a white-noise random potential. We find that the Zakrzewski-Delande conjecture is still valid even if the lowest weak localization corrections are taken into account. The ratio of mean level curvature modulus to mean dissipative conductance is proved to be universal and equal to $2\pi$ in agreement with available numerical data.Comment: 12 pages. Submitted to Phys.Rev.

Dietary cholesterol promotes repair of demyelinated lesions in the adult brain

Multiple Sclerosis (MS) is an inflammatory demyelinating disorder in which remyelination failure contributes to persistent disability. Cholesterol is rate-limiting for myelin biogenesis in the developing CNS; however, whether cholesterol insufficiency contributes to remyelination failure in MS, is unclear. Here, we show the relationship between cholesterol, myelination and neurological parameters in mouse models of demyelination and remyelination. In the cuprizone model, acute disease reduces serum cholesterol levels that can be restored by dietary cholesterol. Concomitant with blood-brain barrier impairment, supplemented cholesterol directly supports oligodendrocyte precursor proliferation and differentiation, and restores the balance of growth factors, creating a permissive environment for repair. This leads to attenuated axon damage, enhanced remyelination and improved motor learning. Remarkably, in experimental autoimmune encephalomyelitis, cholesterol supplementation does not exacerbate disease expression. These findings emphasize the safety of dietary cholesterol in inflammatory diseases and point to a previously unrecognized role of cholesterol in promoting repair after demyelinating episodes

Nonlinear localized waves in a periodic medium

We analyze the existence and stability of nonlinear localized waves in a periodic medium described by the Kronig-Penney model with a nonlinear defect. We demonstrate the existence of a novel type of stable nonlinear band-gap localized states, and also reveal an important physical mechanism of the oscillatory wave instabilities associated with the band-gap resonances.Comment: 4 pages, 5 figure