POSSIBLE SOURCE OF SECONDARY INVADING STAPHYLOCOCCI IN MICE EXPOSED TO ACUTE COLD

Miraglia, Gennaro J. (Bryn Mawr College, Bryn Mawr, Pa.) and L. Joe Berry. Possible source of secondary invading staphylococci in mice exposed to acute cold. J. Bacteriol. 85:345-348. 1963.-In an effort to determine the origin of the staphylococci known to invade the deep tissues (liver, spleen, kidneys, lungs, and heart) of mice exposed continuously to 5 C in individual compartments without bedding, the intestinal tract was freed of these organisms, as judged by absence of growth when fecal suspensions were inoculated into selective media. Substitution of 0.01 n hydrochloric acid for drinking water eliminated staphylococci within a few days, yet the incidence of tissue invasion was unaltered. The coagulase-negative strains normally present in feces and in tissues persisted in tissues even though the intestine was seeded with a coagulase-positive strain by feeding contaminated food. Cultures from the external nares continued unaltered. This suggests that the respiratory tract is a possible origin of the staphylococci found in tissues of the cold-stressed mice.     

Histochemical observations on the taste buds of the marmosets (Callithrix jacchus and Callithrix penicillata).

The epithelial cells in the taste buds of C. jacchus and C. penicillata show a moderate amount of ribonucleic acid an a concentration of a PAS-positive diastase-resistant material at their apical part. These cells are devoid of UDPG-GT, phosphorylases, G-6-PA, alanyl aminopeptidase, leucine aminopeptidase, cholinesterase and MAO; they present a weak reaction of F-1, 6-P Ald, LDH, SDH, MDH, cytochrome oxidase, beta-OHBDH, nonspecific esterase and acid phosphatase and a stronger reaction to ADH, NADPH2-TR, ATPases, alpha-GPDH, alkaline phosphatase, 5-nucleotidase and GDH. Although some enzymes (alkaline phosphatase, 5-nucleotidase and ATPases) have an almost uniform reactivity by the several taste buds, the other ones react with a lesser intensity in the smaller uniform reactivity by the several taste buds, the other ones react with a lesser intensity in the smaller taste buds of the fungiform papillae. As a rule the apical part of the cells shows a stronger enzymatic reactivity. The taste buds of the marmosets are penetrated by acetylcholinesterase positive nerve fibers whereas the autonomic ganglia in the connective tissue contain both-acetyl and butyrylcholinesterase.     

Patterns of Root Colonization in Epacridaceous Plants Collected from Different Sites

Root colonization was studied in ten species of the Epacridaceaeat three sites in Victoria by morphological and cross-inoculationexperiments. The sites and genera chosen were Cranbourne [Epacrisimpressa Labill. andLeucopogon ericoides(Smith) R. Br.] andRye [L. parviflorus(Andrews) Lindley] on the Mornington Peninsula,and the Grampians[Astroloma conostephioides(Sond.) Benth.,A.humifusum(Cav.) R. Br.,A pinifolium(R. Br.) Benth,Brachylomadaphnoides(Smith) Benth.,E. impressa, E. impressavar.grandifloraBenth.andStyphelia adscendensR. Br.] in western Victoria. For morphologicalstudies, samples of roots from each species at each site werecleared and stained and examined microscopically. For cross-inoculationstudies, cuttings from each site were struck in potting mediuminoculated with soil from the same and other sites. The ericoidmycorrhizae in the roots of plants found at or grown in Cranbourneand Rye soils were similar. Both were significantly differentfrom the internal hyphae found in the roots of plants foundat or grown in Grampians soils, which were three times largerin diameter and formed dense coils which filled the host celland invaded adjacent epidermal cells. This suggests that morethan one fungus is involved in the relationships, that the MorningtonPeninsula sites had a different fungus from the Grampians siteand that host specificity is low. Vesicular structures werealso found commonly on plants at the Grampians site, in contrastwith other sites. Epacridaceae; root; fungus; mycorrhiza; morphology; inoculation     

The human AC133 hematopoietic stem cell antigen is also expressed in epithelial cells and targeted to plasma membrane protrusions

The human AC133 antigen and mouse prominin are structurally related plasma membrane proteins. However, their tissue distribution is distinct, with the AC133 antigen being found on hematopoietic stem and progenitor cells and prominin on various epithelial cells. To determine whether the human AC133 antigen and mouse prominin are orthologues or distinct members of a protein family, we examined the human epithelial cell line Caco-2 for the possible expression of the AC133 antigen. By both immunofluorescence and immunoprecipitation, the AC133 antigen was found to be expressed on the surface of Caco-2 cells. Interestingly, immunoreactivity for the AC133 antigen, but not its mRNA level, was down-regulated upon differentiation of Caco-2 cells. The AC133 antigen was specifically located at the apical rather than basolateral plasma membrane. An apical localization of the AC133 antigen was also observed in various human embryonic epithelia including the neural tube, gut, and kidney. Electron microscopy revealed that, within the apical plasma membrane of Caco-2 cells, the AC133 antigen was confined to microvilli and absent from the planar, intermicrovillar regions. This specific subcellular localization did not depend on an epithelial phenotype, because the AC133 antigen on hematopoietic stem cells, as well as that ectopically expressed in fibroblasts, was selectively found in plasma membrane protrusions. Hence, the human AC133 antigen shows the features characteristic of mouse prominin in epithelial and transfected non-epithelial cells, i.e. a selective association with apical microvilli and plasma membrane protrusions, respectively. Conversely, flow cytometry of murine CD34(+) bone marrow progenitors revealed the cell surface expression of prominin. Taken together, the data strongly suggest that the AC133 antigen is the human orthologue of prominin.     

Ultrasound imaging in an experimental model of fatty liver disease and cirrhosis in rats

Background

Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries. Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. The first successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.

Results

This study demonstrates that atypical scrapie has distinct clinical, pathological and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.

Conclusions

Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage.     

Mapping of citrullinated fibrinogen B-cell epitopes in rheumatoid arthritis by imaging surface plasmon resonance

Introduction  

Rheumatoid arthritis (RA) frequently involves the loss of tolerance to citrullinated antigens, which may play a role in pathogenicity. Citrullinated fibrinogen is commonly found in inflamed synovial tissue and is a frequent target of autoantibodies in RA patients. To obtain insight into the B-cell response to citrullinated fibrinogen in RA, its autoepitopes were systematically mapped using a new methodology.     

Quantification of global transcription patterns in prokaryotes using spotted microarrays

We describe an analysis, applicable to any spotted microarray dataset produced using genomic DNA as a reference, that quantifies prokaryotic levels of mRNA on a genome-wide scale. Applying this to Mycobacterium tuberculosis, we validate the technique, show a correlation between level of expression and biological importance, define the complement of invariant genes and analyze absolute levels of expression by functional class to develop ways of understanding an organism's biology without comparison to another growth condition.