68 research outputs found

    The Ronda Peridotite: Garnet-, Spinel-, and Plagioclase-Lherzolite Facies and the P-T Trajectories of a High-Temprature Mantle Intrusion

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    The Ronda peridotite is a high-temperature, alpine-type peridotite emplaced in the internal Zone of the Betic Cordilleras, southern Spain. Using the mineral assemblages of the peridotite and mafic layers, the peridotite mass has been subdivided into 4 zones of mineral facies: (1) garnet-lherzolite facies, (2) ariégite subfacies of spinel-lherzolite facies, (3) seiland subfacies of spinel-lherzolite facies, and (4) plagioclase-lherzolite facies. It is proposed that this mineralogical zonation developed through a syntectic recrystallization of a hot (1100 to 1200°C), solid mantle peridotite during its ascent into the Earth's crust. Coexisting minerals from 12 peridotites covering all the mineral facies above were analysed with an electron microprobe. Core compositions of pyroxene porphyroclasts are constant in all mineral facies and indicate that the peridotite was initially equilibrated at temperatures of 1100 to 1200 °C and pressures of 20 to 25 kb. In contrast, the compositions of pyroxene neoblasts and spinel grains (which appear to have grown during later recrystallization) are well correlated with mineral facies. They indicate that the recrystallization temperature throughout the mass is more or less constant, 800 to 900 °C, but that the pressure ranges from 5-7 kb in the plagioclase-lherzolite facies to 12-15 kb in the garnet-lherzolite facies. Therefore, variation in pressure appears to be primarily responsible for the four mineral facies types. A pressure range of at least 5 kb appears to be too large to have been maintained (at the same time) in a mass as small as the Ronda peridotite. Dynamic cooling may explain the observed variation in the recrystallization pressure; i.e. during the intrusion of the peridotite body, different parts of the body have followed different P-T paths in response to different local cooling rates. Comparing the inferred P-T paths for the peridotite with published melting temperature of peridotite and mafic rocks, it is concluded that the peridotite did not go through partial fusion during the ascent. A hypothetical, diapiric uprise that caused partial fusion and igneous differentiation of the mantle peridotite is considered to be a separate event prior to the ascent that started from about 70 km depth in the upper mantle. Estimates of cooling rates and of Al diffusion rates in pyroxenes suggest that the ascent rate of the peridotite body was greater than 1 meter/yea

    Alteration in Murine Epidermal Langerhans Cell Population by Various UV Irradiations: Quantitative and Morphologic Studies on the Effects of Various Wavelengths of Monochromatic Radiation on Ia-Bearing Cells

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    The present study was undertaken in order to clarify the exact mode of the Langerhans cell (LC) depleting process caused by UV irradiation. Following irradiation with a single dose of various wavelengths of monochromatic UV radiation (UVR), we studied the number of Ia-positive cells in mouse epidermal sheets quantitatively, particularly with regard to dose-response relationship, action spectrum, and time course change. In addition, we studied morphologic alterations of these cells using electron- and immunoelectron microscopy (EM and IEM).We obtained the following results after a single dose of UVB radiation (200 mJ/cm2 of 300 nm) or PUVA (1% of 8-methoxypsoralen (8-MOP) 20 ÎŒ1 and 1 J/cm2 of 360 nm): (1) EM and IEM showed that while some LCs simply lost their Ia marker without any structural alterations, the majority of the LCs disappeared due to actual cell damage. (2) During an ‘injury phase,” the initial 48 h, and a “recovery phase,” lasting from 4–14 days after irradiation, enlargement of the size of remaining Ia-positive LCs occurred. The degree of enlargement was closely related to the degree of reduction in number, suggesting a process compensating for the loss of the LC population. (3) It was found that the recovery rate of LCs after irradiation damage was slower than that of keratinocytes, indicating different cell kinetics between these distinct cell populations in the epidermis, i.e., restoration of LCs after irradiation seems to be achieved at least partially through a repopulation process originating in the bone marrow.Studies with irradiation of various monochromatic wavebands, with or without topical 8-MOP, showed that the action spectrum for Ia-positive cell depletion activity lay within the spectrum shorter than 300 nm for UVR alone, and between 320–380 nm for 8-MOP plus UVR. Since the action spectra were similar to those for keratinocyte damage, i.e., sunburn cell formation, induction of unscheduled DNA synthesis, and to those for UVR-induced erythema, we conclude that common mechanisms underlie these types of tissue damage

    Petrology and petrogenesis of the Ronda high-temperature peridotite intrusion, southern Spain.

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    Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.Microfiche copy available in Archives and Science.Bibliography : leaves 202-217.Ph.D

    Successful Repeated Transcatheter Arterial Embolization (TAE) for Multiple Liver Metastases from Breast Cancer

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    A 46-year-old female was successfuly treated with repeated transcatheter arterial embolization (TAE) for multiple liver metastases from breast cancer. TAE using mitomycin C and epirubicin hydrochloride with lipiodol emulsion and gelatin sponge particles has been administered to the patient eight times over 4 years. She has also received systemic chemotherapy. She has survived for 6 years and 3 months after the detection of liver metastases

    The SNP rs6508974 in AXL is a functional polymorphism and a promising biomarker for gefitinib treatment

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    Somatic mutations in epidermal growth factor receptor (EGFR) found in lung adenocarcinomas are used as biomarkers for the treatment with EGFR-tyrosine kinase inhibitors, including gefitinib. The bypass tracks with amplification of AXL is one of the mechanisms underlying the resistance to gefitinib. We, therefore, carried out a candidate gene approach method to identify AXL polymorphisms associated with the effectiveness of gefitinib. EGFR mutations were first dentified by mutantenriched PCR-restriction fragment length polymorphism (RFLP), and then 2 tag single nucleotide olymorphisms (SNPs) of AXL were examined by PCR-RFLP in 62 Japanese patients with advanced lung adenocarcinoma and treated with gefitinib in two general hospitals in Nagasaki. Subsequently, the association of EFGR mutations and the AXL polymorphism with the effectiveness of gefitinib was examined in these patients. We next examined the effect of the AXL polymorphism on the expression and function of this gene. It is worthy of note that EGFR mutations and the AXL polymorphism rs6508974 independently contributed to the effectiveness of gefitinib, and the polymorphism was proved to be a possible biomarker for selecting non-responders and responders to gefitinib treatment even in the absence of EGFR mutations. Furthermore, this SNP increased the transcriptional activity of the AXL transcript variant 3, one of the three AXL transcript variants, which to some extent increased the epithelial-mesenchymal transition in cancer cells. Taken together, AXL is one of the genes that determine the effectiveness of gefitinib and a biomarker for selecting non-responders and responders among lung adenocarcinoma patients with no EGFR mutations, suggesting that rs6508974 in AXL might be a functional SNP in lung denocarcinoma

    Novel prospective umbrella-type lung cancer registry study for clarifying clinical practice patterns: CS-Lung-003 study protocol

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    Introduction Conventional cancer registries are suitable for simple surveillance of cancer patients, including disease frequency and distribution, demographics, and prognosis; however, the collected data are inadequate to clarify comprehensively diverse clinical questions in daily practice. Methods We constructed an umbrella‐type lung cancer patient registry (CS‐Lung‐003) integrating multiple related prospective observational studies (linked studies) that reflect clinical questions about lung cancer treatment. The primary endpoint of this registry is to clarify daily clinical practice patterns in lung cancer treatment; a key inclusion criterion is pathologically diagnosed lung cancer. Under this registry, indispensable clinical items are detected in advance across all active linked studies and gathered prospectively and systematically to avoid excessive or insufficient data collection. Researchers are to input information mutually, irrespective of the relevance to each researcher's own study. Linked studies under the umbrella of the CS‐Lung‐003 registry will be updated annually with newly raised clinical questions; some linked studies will be newly created, while others will be deleted after the completion of the analysis. Enrollment began in July 2017. Discussion We successfully launched the umbrella‐type CS‐Lung‐003 registry. Under this single registry, researchers collaborate on patient registration and data provision for their own and other studies. Thus, the registry will produce results for multiple domains of study, providing answers to questions about lung cancer treatment raised by other researchers. Through such analysis of each linked study, this registry will contribute to the comprehensive elucidation of actual daily practice patterns in lung cancer treatment. Key points CS‐Lung‐003 registry directly integrates multiple linked studies created under the umbrella of this cancer registry to solve various clinical questions regarding daily practice patterns of lung cancer treatment

    Biallelic Variants in UBA5 Link Dysfunctional UFM1 Ubiquitin-like Modifier Pathway to Severe Infantile-Onset Encephalopathy

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    The ubiquitin fold modifier 1 (UFM1) cascade is a recently identified evolutionarily conserved ubiquitin-like modification system whose function and link to human disease have remained largely uncharacterized. By using exome sequencing in Finnish individuals with severe epileptic syndromes, we identified pathogenic compound heterozygous variants in UBAS, encoding an activating enzyme for UFM1, in two unrelated families. Two additional individuals with biallelic UBAS variants were identified from the UK-based Deciphering Developmental Disorders study and one from the Northern Finland Intellectual Disability cohort. The affected individuals (n = 9) presented in early infancy with severe irritability, followed by dystonia and stagnation of development. Furthermore, the majority of individuals display postnatal microcephaly and epilepsy and develop spasticity. The affected individuals were compound heterozygous for a missense substitution, c.1111G>A (p.A1a371Thr; allele frequency of 0.28% in Europeans), and a nonsense variant or c.164G>A that encodes an amino acid substitution p.Arg5SHis, but also affects splicing by facilitating exon 2 skipping, thus also being in effect a loss-of-function allele. Using an in vitro thioester formation assay and cellular analyses, we show that the p.A1a371Thr variant is hypomorphic with attenuated ability to transfer the activated UFM1 to UFC1. Finally, we show that the CNS-specific knockout of Ufml in mice causes neonatal death accompanied by microcephaly and apoptosis in specific neurons, further suggesting that the UFM1 system is essential for CNS development and function. Taken together, our data imply that the combination of a hypomorphic p.A1a371Thr variant in trans with a loss-of-function allele in UBAS underlies a severe infantile-onset encephalopathy.Peer reviewe
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