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Richard Jordan

    Richard Jordan

    Ectomesenchymal chondromyxoid tumor is a rare and benign neoplasm with a predilection for the anterior dorsal tongue. Despite morphologic heterogeneity, most cases are characterized by a proliferation of bland spindle cells with a... more
    Ectomesenchymal chondromyxoid tumor is a rare and benign neoplasm with a predilection for the anterior dorsal tongue. Despite morphologic heterogeneity, most cases are characterized by a proliferation of bland spindle cells with a distinctive reticular growth pattern and myxoid stroma. The immunophenotype of these neoplasms is likewise variable; most cases express glial fibrillary acid protein and S100 protein, with inconsistent reports of keratin and myoid marker expression. The molecular pathogenesis is poorly understood; however, a subset of cases has been reported to harbor EWSR1 gene rearrangement. Following identification of an RREB1-MKL2 fusion gene by RNA Sequencing in an index patient, a retrospective review of additional cases of ectomesenchymal chondromyxoid tumors was performed to better characterize the clinical, immunohistochemical, and molecular attributes of this neoplasm. A total of 21 cases were included in this series. A marked predisposition for the dorsal tongue...
    Sea-ice concentration in the central Arctic Ocean is typically 85–95% during summers and much of this ice consists of 2–5m thich multi-year ice. The Arctic Coring Expedition (ACEX, IODP Exp. 302) operated continuously in >90% ice cover... more
    Sea-ice concentration in the central Arctic Ocean is typically 85–95% during summers and much of this ice consists of 2–5m thich multi-year ice. The Arctic Coring Expedition (ACEX, IODP Exp. 302) operated continuously in >90% ice cover while on site, which was dominated by multi-year ice. The primary goal of ACEX was to continuously recover a >400m thich sediment sequence draping the crest of the Lomonosov Ridge in the central Arctic Ocean between 87°N and 88°N. This would meet the fundamental paleoceanographic objective of ACEX, namely to determine the Cenozoic paleoenvironmental evolution in the central Arctic Ocean. ACEX was executed using three platforms: Vidar Viking (drilling platform), Oden (support icbreaker, operational HQ, research lab and science center), and Sovetskiy Soyuz (nuclear support icebreaker). Over a period of 22.5 days from August 15th to September 5th, the drill-ship lept its position over site in about 1200m water depth for 15.1 days (~97% of the time within ±50m) through manual steering of the ship. During that period, three scientists were helicoptered to/from the drill-ship twice/day. Three sites were drilled along a single reflection seismic profile (AWI-91090) showing a coherent seismostratigraphy. Ice drift determined the exact drilling location. A total of 495.47 m was cored, resulting in a recovery of 339.06 m in 110 XCB-cores and 8 APC-cores (68% recovery). The deepest hole was terminated at 427.9 mbsf. Preliminary analyses of about 4% of these sediments were made onboard the Oden during the offshore phase. The remaining sections were subsequently split and described by the onshore science party at Bremen University. Biogenic carbonate were encountered only in the Holocene and uppermost Pleistocene sections. The Pleistocene and Neogene sections show biogenic components. It follows that the central Arctic Ocean was not a sediment starved basin during these times. A 22 m thich (171-193 mbsf) palynologically barren interval separates the overlying middle Miocene from the underlying middle Eocene, which presumably preserves some of the intervening lower Neogene and upper Paleogene sections. Sand lenses occur frequently down to 198 mbsf (middle Miocene) and cm-sized pebbles occur more or less continuously down to 239 mbsf (middle Eocene). Both sand and pebbles are interpreted to represent ice-rafted debris. The average sedimentation rate in the middle Eocene to uppermost Paleocene section is about 1.6 cm/ka. A 107 m thick middle to upper lower Eocene interval hosts rich biosiliceous assemblages in which radiolarians by-and-large are missing, probably indicating reduces surface water salinities. The lower Eocene to uppermost Paleocene interval, below the biosilica interval, consists of dark clays/shales often showing sub-mm laminations and presence of pyrite nodules. The transition to the underlying sedimentary bedrock was not sampled because of recovery problems. The oldest sediment sampled consists of 1.39 m of shallow-marine dark layey mud of Campanian age.
    In September 2004, the first-ever drilling of the Lomonosov Ridge (Arctic Coring Expedition, ACEX, aka IODP Expedition 302) recovered unprecedented climate records of the Arctic Ocean spanning the past ~56 Ma. Initial, mainly... more
    In September 2004, the first-ever drilling of the Lomonosov Ridge (Arctic Coring Expedition, ACEX, aka IODP Expedition 302) recovered unprecedented climate records of the Arctic Ocean spanning the past ~56 Ma. Initial, mainly dinoflagellate based age-assessments include the recognition of some ~200m each of upper Neogene, and middle Paleogene deposits, with a conspicuous ~25 Ma hiatus separating these units. The Neogene record appears one of slow sedimentation rates and frequent glacial conditions – contrasting the Paleogene, which is a story of waxing and waning of freshwater influence, warm conditions, and relatively high accumulation rates of organic-rich sediments. Paleogene highlights include the early–middle Eocene transition (~50 Ma) yielding stunning concentrations of remains of the freshwater fern Azolla suggesting that at least episodically, completely fresh surface water settings characterized the Arctic Basin. Moreover, although predictions had placed the base of the sediment column at 50 Ma, palynology revealed the successful recovery of the Paleocene–Eocene transition. During this time of super-greenhouse conditions, ~55.5 Ma ago, our records show the Arctic to be subtropical. ACEX also penetrated into some 30m of 'basement', the underlying tectinized sedimentary bedrock. Palynology confirmed the hypothesis that the top of the Lomonosov Ridge 'basement' is of shallow-water origin, and has a Campanian age.
    The ultimate objective of palaeoceanographic and palaeoclimatic research consists of decoding the record of past climatic changes, to explain it, and to make use of this understanding to improve models that predict them. Our efforts to... more
    The ultimate objective of palaeoceanographic and palaeoclimatic research consists of decoding the record of past climatic changes, to explain it, and to make use of this understanding to improve models that predict them. Our efforts to describe past climatic variability throughout the course of the Cenozoic have made great progress over the last few years, mostly due to the efforts of ocean drilling, and we are now in a position to recognise many previously unknown, presumably climate and ocean circulation related "events", particularly in the Oligocene and Eocene . Equally, great strides have been made to explain the longer term evolution of the climatic system within a framework of climate "forcing", predominantly by recognising the role that the changing orbital configuration plays in re-occurring oceanic patterns, and repeated cycles in climate expressions such as sea-level, and past temperatures. For many years now there have been separate efforts to understand the relative importance of high- and low latitude processes that are predicted by changes of the Earth's orbital orientation. During August and September 2004 the Arctic Coring Expedition (IODP 302) recovered the first long record of sediments from near the North Pole. This sedimentary record, although incomplete, now offers the chance to test simple predictions that arise from orbital theory, for example whether the Earth system near the poles exhibits an amplified response to obliquity forcing in general, and whether the nature of this response was different for the Eocene, a presumed "warm-house", and the more recent ice-dominated geological history. We will present the first results from the stratigraphic correlation of high-resolution physical properties records from the Arctic, the implications of biostratigraphically derived age models of these data, as well as the first interpretation of cyclic changes encoded in the sediments and how these relate to possible forcing mechanisms at very high latitudes.
    Reduced levels of p27Kip1 are frequent in human cancers and have been associated with poor prognosis. Skp2, a component of the Skp1-Cul1-F-box protein (SCF) ubiquitin ligase complex, has been implicated in p27Kip1 degradation. Increased... more
    Reduced levels of p27Kip1 are frequent in human cancers and have been associated with poor prognosis. Skp2, a component of the Skp1-Cul1-F-box protein (SCF) ubiquitin ligase complex, has been implicated in p27Kip1 degradation. Increased Skp2 levels are seen in some solid tumors and are associated with reduced p27Kip1. We examined the expression of these proteins using single and double immunolabeling in a large series of lymphomas to determine if alterations in their relative levels are associated with changes in cell proliferation and lymphoma subgroups. We studied the expression of Skp2 in low-grade and aggressive B-cell lymphomas (n = 86) and compared them with p27Kip1 and the proliferation index (PI). Fifteen hematopoietic cell lines and peripheral blood lymphocytes were studied by Western blot analysis. In reactive tonsils, Skp2 expression was limited to proliferating germinal center and interfollicular cells. Skp2 expression in small lymphocytic lymphomas (SLLs) and follicular...
    Purpose: Oral fluid (saliva) meets the demand for noninvasive, accessible, and highly efficient diagnostic medium. Recent discovery that a large panel of human RNA can be reliably detected in saliva gives rise to a novel clinical... more
    Purpose: Oral fluid (saliva) meets the demand for noninvasive, accessible, and highly efficient diagnostic medium. Recent discovery that a large panel of human RNA can be reliably detected in saliva gives rise to a novel clinical approach, salivary transcriptome diagnostics. The purpose of this study is to evaluate the diagnostic value of this new approach by using oral squamous cell carcinoma (OSCC) as the proof-of-principle disease. Experimental Design: Unstimulated saliva was collected from patients (n = 32) with primary T1/T2 OSCC and normal subjects (n = 32) with matched age, gender, and smoking history. RNA isolation was done from the saliva supernatant, followed by two-round linear amplification with T7 RNA polymerase. Human Genome U133A microarrays were applied for profiling human salivary transcriptome. The different gene expression patterns were analyzed by combining a t test comparison and a fold-change analysis on 10 matched cancer patients and controls. Quantitative pol...
    The CDKN2A gene locus encodes two different proteins derived from alternative splicing. p16 (exons 1alpha, 2, and 3) acts as a G1 cell cycle regulator, and p14ARF (exons 1beta, 2, and 3) acts to modulate MDM2-mediated degradation of p53.... more
    The CDKN2A gene locus encodes two different proteins derived from alternative splicing. p16 (exons 1alpha, 2, and 3) acts as a G1 cell cycle regulator, and p14ARF (exons 1beta, 2, and 3) acts to modulate MDM2-mediated degradation of p53. Inactivation of p16 is a common finding in many cancers; however, there is little data on CDKN2A gene abnormalities in oral precancer. In this longitudinal study, we examined changes in the CDKN2A gene locus in sequential epithelial dysplasias and oral carcinomas from 11 patients. Genomic DNA was extracted from laser-microdissected lesional tissue, and exons 1alpha, 1beta, and 2 were analyzed by duplex PCR. Immunohistochemistry was done to identify p16 and p14ARF protein expression. Two adjacent polymorphic microsatellite markers were used for allelotyping. Homozygous deletion of exon 1alpha was identified in 2 of 17 (12%) precancerous lesions. Loss of either exon 1alpha, exon 2, or both was seen in seven of nine (78%) carcinomas. In five of these c...
    Skp2 is a member of the F-box family of substrate-recognition subunits of SCF ubiquitin–protein ligase complexes that has been implicated in the ubiquitin-mediated degradation of several key regulators of mammalian G 1 progression,... more
    Skp2 is a member of the F-box family of substrate-recognition subunits of SCF ubiquitin–protein ligase complexes that has been implicated in the ubiquitin-mediated degradation of several key regulators of mammalian G 1 progression, including the cyclin-...