1,127 research outputs found
An early Pennsylvanian Flora with \u3cem\u3eMegalopteris\u3c/em\u3e and Noeggerathiales from west-central Illinois
The Spencer Farm Flora is a compression-impression flora of early Pennsylvanian age (Namurian B, or possibly Namurian C) from Brown County, west-central Illinois. The plant fossils occur in argillaceous siltstones and sandstones of the Caseyville Formation that were deposited in a ravine eroded in Mississippian carbonate rocks. The plant-bearing beds are the oldest deposits of Pennsylvanian age yet discovered in Illinois. They were formed before extensive Pennsylvanian coal swamps developed.
The flora consist of 29 species and a few problematical forms. It represents an unusual biofacies, in which the generally rare genera Megalopteris, Lesleya, Palaeopteridium, and Lacoea are quite common. Noeggerathiales, which are seldom present in roof-shale floras, make up 20% of the specimens. The Spencer Farm Flora is and extrabasinal (= upland ) flora that was growing on the calcareous soils in the vicinity of the ravine in which they were deposited.
It is suggested here that Noeggerathiales may belong to the Progymnosperms and that Noeggerathialian cones might be derived from Archaeopteris-like fruitifications. The cone genus Lacoea is intermediate between Noeggerathiostrobus and Discinites in its morphology. Two new species, Lesleya cheimarosa and Rhodeopteridium phillipsii, are described, and Gulpenia limburgensis is reported from North America for the first time
A Late Devonian isoetalean lycopsid, Otzinachsonia beerboweri gen. et sp nov., from North-Central Pennsylvania, USA
A Late Devonian Isoetalean Lycopsid, \u3cem\u3eOtzinachsonia Beerboweri\u3c/em\u3e, Gen. Et Sp. Nov., From North-Central Pennsylvania, USA
Compressions and impressions of an isoetalean lycopsid, comprising lower portions of stems, lobed bases, attached rootlets, and rounded rootlet scars, discovered in Late Devonian (Famennian) rocks of Clinton County, north-central Pennsylvania, Appalachian Basin, USA, are here described as Otzinachsonia beerboweri, gen. et sp. nov. These specimens demonstrate unequivocally the existence of the isoetalean lobe-and-furrow rhizomorphic growth pattern as early as the Late Devonian. They were found in an Archaeopteris- and Rhacophyton-dominated flora at Red Hill, an outcrop of the Duncannon Member of the Catskill Formation. The fossils were found in a dark-gray to greenish-gray lenticular siltstone layer that has an average thickness of 1.0 m. This deposit is interpreted as a floodplain pond. The low-energy nature of the deposit and the fine preservation of the intact rootlets of the specimens imply little or no transport. The plants were probably growing along the edge of the floodplain pond with their lower portions submerged for at least part of the year
Transmembrane signaling: an ion-flux-independent model for signal transduction by complexed Fc receptors.
A concept for the treatment of relapsed intermediate and high-grade NHL: Stem dell collection after IEV chemotherapy plus G.CSF, immunomagnetic purging of P.B.S.C. using Moabs against B-cell antigens in patients with CB/CC NHL and stem cell transplantation after high-dose BU/CY.
Antiparasitic and Antiproliferative Effects of Indoleamine 2,3-dioxygenase Enzyme Expression in Human Fibroblasts.
Studies were carried out to evaluate the proposed role of indoleamine 2,3-dioxygenase (INDO) induction in the antimicrobial and antiproliferative effects of gamma interferon (IFN-gamma) in human fibroblasts. The INDO cDNA coding region was cloned in the pMEP4 expression vector, containing the metallothionein (MTII) promoter in the sense (+ve) or the antisense (-ve) orientation. Human fibroblasts (GM637) stably transfected with the sense construct expressed INDO activity after treatment with CdCl2 or ZnSO4, but cells transfected with the antisense construct did not. The growth of Chlamydia psittaci was strongly inhibited in INDO +ve cells but not in INDO -ve cells after treatment with Cd2+ or Zn2+. The inhibition correlated with the level of INDO activity induced and could be reversed by the addition of excess tryptophan to the medium. The growth of Toxoplasma gondii was also strongly inhibited in INDO +ve cells but not in INDO -ve cells after treatment with Cd2+. Expression of Cd(2+)-induced INDO activity also inhibited thymidine incorporation and led to cytotoxicity in INDO +ve cells but not in INDO -ve cells. Thus, the induction of INDO activity by IFN-gamma may be an important factor in the antimicrobial and antiproliferative effects of IFN-gamma in human fibroblasts
Regional astrocyte IFN signaling restricts pathogenesis during neurotropic viral infection
Type I IFNs promote cellular responses to viruses, and IFN receptor (IFNAR) signaling regulates the responses of endothelial cells of the blood-brain barrier (BBB) during neurotropic viral infection. However, the role of astrocytes in innate immune responses of the BBB during viral infection of the CNS remains to be fully elucidated. Here, we have demonstrated that type I IFNAR signaling in astrocytes regulates BBB permeability and protects the cerebellum from infection and immunopathology. Mice with astrocyte-specific loss of IFNAR signaling showed decreased survival after West Nile virus infection. Accelerated mortality was not due to expanded viral tropism or increased replication. Rather, viral entry increased specifically in the hindbrain of IFNAR-deficient mice, suggesting that IFNAR signaling critically regulates BBB permeability in this brain region. Pattern recognition receptors and IFN-stimulated genes had higher basal and IFN-induced expression in human and mouse cerebellar astrocytes than did cerebral cortical astrocytes, suggesting that IFNAR signaling has brain regionâspecific roles in CNS immune responses. Taken together, our data identify cerebellar astrocytes as key responders to viral infection and highlight the existence of distinct innate immune programs in astrocytes from evolutionarily disparate regions of the CNS
Extent of hypoattenuation on CT angiography source images in Basilar Artery occlusion: prognostic value in the Basilar Artery International Cooperation Study
<p><b>Background and Purpose:</b> The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) quantifies the extent of early ischemic changes in the posterior circulation with a 10-point grading system. We hypothesized that pc-ASPECTS applied to CT angiography source images predicts functional outcome of patients in the Basilar Artery International Cooperation Study (BASICS).</p>
<p><b>Methods:</b> BASICS was a prospective, observational registry of consecutive patients with acute symptomatic basilar artery occlusion. Functional outcome was assessed at 1 month. We applied pc-ASPECTS to CT angiography source images of patients with CT angiography for confirmation of basilar artery occlusion. We calculated unadjusted and adjusted risk ratios (RRs) of pc-ASPECTS dichotomized at ≥8 versus <8. Primary outcome measure was favorable outcome (modified Rankin Scale scores 0â3). Secondary outcome measures were mortality and functional independence (modified Rankin Scale scores 0â2).</p>
<p><b>Results:</b> Of 158 patients included, 78 patients had a CT angiography source images pc-ASPECTS â„8. Patients with a pc-ASPECTS â„8 more often had a favorable outcome than patients with a pc-ASPECTS <8 (crude RR, 1.7; 95% CI, 0.98â3.0). After adjustment for age, baseline National Institutes of Health Stroke Scale score, and thrombolysis, pc-ASPECTS ≥8 was not related to favorable outcome (RR, 1.3; 95% CI, 0.8â2.2), but it was related to reduced mortality (RR, 0.7; 95% CI, 0.5â0.98) and functional independence (RR, 2.0; 95% CI, 1.1â3.8). In post hoc analysis, pc-ASPECTS dichotomized at ≥6 versus <6 predicted a favorable outcome (adjusted RR, 3.1; 95% CI, 1.2â7.5).</p>
<p><b>Conclusions:</b> pc-ASPECTS on CT angiography source images independently predicted death and functional independence at 1 month in the CT angiography subgroup of patients in the BASICS registry.</p>
Individual Response to Risk As a Function of Normative Social Pressure: A Pilot Study of Seat Belt Use
The authors attempt to clarify some of the variables that influence whether people act appropriately when a Risk is substantial and subject to individual control. They do so by reporting results of a pilot study of seat belt use. Also, the authors believe their approach to be generalizable to problems such as encouraging people to test for radon, to use condoms to prevent AIDS or to quit smoking
Cysteinyl Leukotriene Levels in Esophageal Mucosal Biopsies of Children with Eosinophilic Inflammation: Are They All the Same?
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75498/1/j.1572-0241.2006.00557.x.pd
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