91 research outputs found
Intraepithelial and Interstitial Deposition of Pathological Prion Protein in Kidneys of Scrapie-Affected Sheep
Prions have been documented in extra-neuronal and extra-lymphatic tissues of humans and various ruminants affected by Transmissible Spongiform Encephalopathy (TSE). The presence of prion infectivity detected in cervid and ovine blood tempted us to reason that kidney, the organ filtrating blood derived proteins, may accumulate disease associated PrPSc. We collected and screened kidneys of experimentally, naturally scrapie-affected and control sheep for renal deposition of PrPSc from distinct, geographically separated flocks. By performing Western blot, PET blot analysis and immunohistochemistry we found intraepithelial (cortex, medulla and papilla) and occasional interstitial (papilla) deposition of PrPSc in kidneys of scrapie-affected sheep. Interestingly, glomerula lacked detectable signals indicative of PrPSc. PrPSc was also detected in kidneys of subclinical sheep, but to significantly lower degree. Depending on the stage of the disease the incidence of PrPSc in kidney varied from approximately 27% (subclinical) to 73.6% (clinical) in naturally scrapie-affected sheep. Kidneys from flocks without scrapie outbreak were devoid of PrPSc. Here we demonstrate unexpectedly frequent deposition of high levels of PrPSc in ovine kidneys of various flocks. Renal deposition of PrPSc is likely to be a pre-requisite enabling prionuria, a possible co-factor of horizontal prion-transmission in sheep
Carotenoid Distribution in Living Cells of Haematococcus pluvialis (Chlorophyceae)
Haematococcus pluvialis is a freshwater unicellular green microalga belonging to the class Chlorophyceae and is of commercial interest for its ability to accumulate massive amounts of the red ketocarotenoid astaxanthin (3,3′-dihydroxy-β,β-carotene-4,4′-dione). Using confocal Raman microscopy and multivariate analysis, we demonstrate the ability to spectrally resolve resonance–enhanced Raman signatures associated with astaxanthin and β-carotene along with chlorophyll fluorescence. By mathematically isolating these spectral signatures, in turn, it is possible to locate these species independent of each other in living cells of H. pluvialis in various stages of the life cycle. Chlorophyll emission was found only in the chloroplast whereas astaxanthin was identified within globular and punctate regions of the cytoplasmic space. Moreover, we found evidence for β-carotene to be co-located with both the chloroplast and astaxanthin in the cytosol. These observations imply that β-carotene is a precursor for astaxanthin and the synthesis of astaxanthin occurs outside the chloroplast. Our work demonstrates the broad utility of confocal Raman microscopy to resolve spectral signatures of highly similar chromophores in living cells
‘There is a Time to be Born and a Time to Die’ (Ecclesiastes 3:2a): Jewish Perspectives on Euthanasia
Reviewing the publications of prominent American rabbis who have (extensively) published on Jewish biomedical ethics, this article highlights Orthodox, Conservative and Reform opinions on a most pressing contemporary bioethical issue: euthanasia. Reviewing their opinions against the background of the halachic character of Jewish (biomedical) ethics, this article shows how from one traditional Jewish textual source diverse, even contradictory, opinions emerge through different interpretations. In this way, in the Jewish debate on euthanasia the specific methodology of Jewish (bio)ethical reasoning comes forward as well as a diversity of opinion within Judaism and its branches
Nucleic acid malaria vaccines
During the twentieth century, the primary approach to malaria prevention has been to interfere with transmission of the parasite between the infected mosquito and the human host using physical barriers, insecticides and prophylactic drugs. Despite these measures, it is estimated that there are 300-500 new Plasmodium infections and 1-2 million deaths annually due to malaria. Thus, there have been major efforts to develop malaria vaccines. This is thought to be a feasible approach because immunization with radiation-attenuated Plasmodium spp. sporozoites induces sterile protective immunity against malaria in rodents, primates and humans(reviewed in Ref. 2). The complex life cycle of the Plasmodium spp. parasites and the extensive variability among strains of the same Plasmodium species dictate, however, that an effective malaria vaccine will probably need to induce protective antibodies as well as effector CD4+ and CD8+ T lymphocytes specific for variants of multiple antigens expressed at different stages of the life cycle. It is our view that nucleic acid vaccines offer an excellent approach to developing a multivalent vaccine that effectively activates all arms of the immune system. Furthermore, such vaccines may overcome the additional problem inherent in subunit vaccine development: major histocompatibility complex (MHC) restriction of the protective immune responses to identified target epitopes. Supporting data and rationale for our view are presented here. The major emphasis of the work thus far has been to use plasmid DNA to induce protective CD8+ cytotoxic T lymphocytes (CTL), but the induction of protective antibody and CD4+ T cell responses is being investigated
Long-term expression of erythropoietin in the systemic circulation of mice after intramuscular injection of a plasmid DNA vector.
Transmission of enteric disease associated with wastewater irrigation: a prospective epidemiological study.
- …