61 research outputs found

    Fecundity, spore recruitment and size in Gelidium sesquipedale (Gelidiales,Rhodophyta)

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    Gelidium sesquipedale fecundity was quantified by counting tetrasporangial sori and cystocarps per meter squared and by estimating the number of spores contained inside them . These were obtained by regression on a size metric of reproductive structures . Tetrasporangial sori length and cystocarp thickness were the best estimators of spore number. To assess spore recruitment, 12 pottery tiles were fixed to the bottom, and the appearance of small fronds was monitored. No clear seasonal pattern of reproduction was found . Tetraspore production peaked in March 1990 with 10.4 x 106 spores m-2, whereas the carpospore peak was lower, 4.9 x 10 5 spores m-2 in July 1989. Recruitment followed tetraspore peaks . The probability of a G. sesquipedale tetraspore making the transition to a recruit was 4.7 x 10-5. Frond length was significantly related to tetrasporangial sori number, while cystocarp number was only related to frond branching order. Minimum size for reproduction was 6.9 cm for gametophytes and 5.4 cm for tetrasporophytes; very rarely were cystocarpic fronds smaller than 9 cm, while tetrasporic fronds were often longer than 15 cm . Cystocarpic fronds were significantly shorter and had more branches than tetrasporic fronds

    Sporadic Creutzfeldt-Jakob disease with glial PrPRes nuclear and perinuclear immunoreactivity

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    Proteinase K-resistant prion protein (PrPRes ) nuclear and perinuclear immunoreactivity in oligodendrocytes of the frontal cortex is found in one case of otherwise typical sporadic Creutzfeldt-Jakob disease (sCJD) type VV2a. The PrP nature of the inclusions is validated with several anti-PrP antibodies directed to amino acids 130-160 (12F10), 109-112 (3F4), 97-102 (8G8) and the octarepeat region (amino acids 59-89: SAF32). Cellular identification and subcellular localization were evaluated with double- and triple-labeling immunofluorescence and confocal microscopy using antibodies against PrP, glial markers, and histone H3. Based on review of the literature and our own experience, this is a very odd situation that deserves further validation in other cases. Keywords: Creutzfeldt-Jakob disease; astrocytes; oligodendrocytes; prion

    Mutation analysis of the LCE3B/LCE3C genes in Psoriasis

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    <p>Abstract</p> <p>Background</p> <p>An association between a common deletion comprising the late cornified envelope LCE3B and LCE3C genes (LCE3C_LCE3B-del) and Psoriasis (Ps) has been reported. The expression of these LCE genes was induced after skin barrier disruption and was also strong in psoriatic lesions. The damage to the skin barrier could trigger an epidermal response that includes the expression of genes involved in the formation of skin barrier.</p> <p>Methods</p> <p>We determined the LCE3C_LCE3B-del genotype in 405 Ps patients and 400 healthy controls from a Northern Spain region (Asturias). These patients and controls were also genotyped for the rs4112788 single nucleotide polymorphism, in strong linkage disequilibrium with the LCE3C_B cluster. The LCE3B and LCE3C gene variant was determined in the patients through SSCA, DHPLC, and direct sequencing.</p> <p>Results</p> <p>Allele and genotype frequencies did not differ between patients and controls for the rs4112788 and LCE3C_LCE3B-del polymorphisms. However, del/del homozygotes were significantly higher among patients with chronic plaque type Ps who did not develop arthritis (p = 0.03; OR = 1.4; 95%CI = 1.03-1.92). The analysis of the coding sequence of LCE3B and LCE3C in the patients who had at least one copy of this showed that only one patient has a no previously reported LCE3B variant (R68C).</p> <p>Conclusion</p> <p>Our work suggested that homozygosity for a common LCE3C_LCE3B deletion contributes to the risk of developing chronic plaque type Ps without psoriatic arthritis. Our work confirmed previous reports that described an association of this marker with only skin manifestations, and supported the concept of different genetic risk factors contributing to skin and joint disease.</p

    Global dataset of soil organic carbon in tidal marshes.

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    Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha-1 in the top 30 cm and 231 ± 134 Mg SOC ha-1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies

    Global dataset of soil organic carbon in tidal marshes

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    Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha−1 in the top 30 cm and 231 ± 134 Mg SOC ha−1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies

    Characterization of GFAP expression and cell proliferation in the rat median eminence following hypophysectomy

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    To analyze whether the reorganization of the rat median eminence after hypophysectomy might be related to changes in glial fibrillary acidic protein (GFAP)- and cellular proliferation, the distribution of cells immunoreactive for GFAP and the proliferation rate of such cells were analyzed at 20, 40 and 60 days posthypophysectomy. For this study, four rostro-caudal regions of the median eminence were differentiated: the retrochiasmatic, preinfundibular, infundibular and postinfundibular regions. In each of these regions, three layers were studied: the ependymal, the internal and the external. At 20 and 40 days after hypophysectomy, significant increases in cellular proliferation affecting all three layers studied in the preinfundibular and infundibular regions were found. At the same time points, increases in GFAP expression were also observed. However, after 60 days, GFAP and proliferative cellular nuclear antigen (PCNA) expression decreased. Although variations of PCNA and GFAP levels were evident, no colocalisation of PCNA and GFAP was found in the cells of the median eminence in untreated or hypophysectomized rats when sections were analyzed by double immunohistochemical staining. Our results suggest that reorganization of median eminence involves alterations (or modulation) of GFAPimmunoreactive cells together with a proliferation of cells that are not GFAP-immunoreactive. This study also demonstrates that this reorganization is completed within the first two months after hypophysectomy

    Estimated Effect of COVID-19 Lockdown on Skin Tumor Size and Survival: An Exponential Growth Model

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    Antecedentes y objetivos La pandemia del coronavirus SARS-CoV-2 ha provocado un confinamiento indefinido. Una posible consecuencia de esta situación es un retraso en los procedimientos asistenciales de las enfermedades oncológicas. El objetivo de este estudio es estimar el hipotético impacto en la supervivencia que tendría el aumento del tamaño tanto para los carcinomas de células escamosas (CCE) como de los melanomas. Material y método Estudio observacional retrospectivo de cohorte multicéntrico. Se desarrolló un modelo de crecimiento exponencial para cada tumor basado en el tiempo de evolución que refiere el paciente. Resultados Se incluyeron un total de 200 pacientes con CCE localizados en la cabeza y el cuello y 1.000 pacientes con melanoma cutáneo. Se calculó una curva de crecimiento exponencial para cada tumor y se estimó el tamaño del tumor tras 1, 2 y 3 meses tras el diagnóstico. En la muestra, los CCE mayores de 4 cm o > 6 mm de grosor (definidos como T3) pasaron de 83 (41,5%) en el grupo de estudio real a una estimación del 58,5, 70,5 y 72% tras 1, 2 y 3 meses de retraso quirúrgico estimado, respectivamente. Se estimó una disminución de la supervivencia específica de enfermedad (SEE) de un 6,2, 8,2 y 5,2% a los 2, 5 y 10 años, respectivamente, tras 3 meses de retraso. Para los melanomas ultragruesos (> 6 mm de Breslow) pasaron del 6,9% en el grupo de estudio al 21,9, 30,2 y 30,2% tras 1, 2 y 3 meses de demora. La SEE a los 5 y 10 años del grupo de estudio descendió un 14,4% en ambos tiempos. Conclusiones En ausencia de un adecuado diagnóstico y tratamiento de los pacientes con CCE y melanoma en la actual situación de confinamiento en España, podemos llegar a asistir a un considerable aumento de los casos de CCE y melanomas gruesos y de gran tamaño. Se deben fomentar los esfuerzos para promocionar la autoexploración y facilitar el acceso a los dermatólogos para no aumentar la demora de estos pacientes.Background and objectives Spain is in a situation of indefinite lockdown due to the ongoing coronavirus disease 2019 (COVID-19) pandemic. One of the consequences of this lockdown is delays in medical and surgical procedures for common diseases. The aim of this study was to model the impact on survival of tumor growth caused by such delays in patients with squamous cell carcinoma (SCC) and melanoma. Material and methods Multicenter, retrospective, observational cohort study. We constructed an exponential growth model for both SCC and melanoma to estimate tumor growth between patient-reported onset and surgical excision at different time points. Results Data from 200 patients with SCC of the head and neck and 1000 patients with cutaneous melanoma were included. An exponential growth curve was calculated for each tumor type and we estimated tumor size after 1, 2, and 3 months of potential surgical delay. The proportion of patients with T3 SCC (diameter >4cm or thickness >6 mm) increased from 41.5% (83 patients) in the initial study group to an estimated 58.5%, 70.5%, and 72% after 1, 2, and 3 months of delay. Disease-specific survival at 2, 5, and 10 years in patients whose surgery was delayed by 3 months decreased by 6.2%, 8.2%, and 5.2%, respectively. The proportion of patients with ultrathick melanoma (>6 mm) increased from 6.9% in the initial study group to 21.9%, 30.2%, and 30.2% at 1, 2, and 3 months. Five- and 10-year disease-specific survival both decreased by 14.4% in patients treated after a potential delay of 3 months. Conclusions In the absence of adequate diagnosis and treatment of SCC and melanoma in the current lockdown situation in Spain, we can expect to see to a considerable increase in large and thick SCCs and melanomas. Efforts must be taken to encourage self-examination and facilitate access to dermatologists in order to prevent further delays
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