105 research outputs found

    Thermoelectric properties of Ca0.8Dy0.2MnO3 synthesized by solution combustion process

    Get PDF
    High-quality Ca0.8Dy0.2MnO3 nano-powders were synthesized by the solution combustion process. The size of the synthesized Ca0.8Dy0.2MnO3 powders was approximately 23 nm. The green pellets were sintered at 1150-1300°C at a step size of 50°C. Sintered Ca0.8Dy0.2MnO3 bodies crystallized in the perovskite structure with an orthorhombic symmetry. The sintering temperature did not affect the Seebeck coefficient, but significantly affected the electrical conductivity. The electrical conductivity of Ca0.8Dy0.2MnO3 increased with increasing temperature, indicating a semiconducting behavior. The absolute value of the Seebeck coefficient gradually increased with an increase in temperature. The highest power factor (3.7 × 10-5 Wm-1 K-2 at 800°C) was obtained for Ca0.8Dy0.2MnO3 sintered at 1,250°C. In this study, we investigated the microstructure and thermoelectric properties of Ca0.8Dy0.2MnO3, depending on sintering temperature

    Abscopal effect of radiation on lung metastases of hepatocellular carcinoma: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>The abscopal effect is the effect of radiation therapy at a site distant to the area of irradiation. This is not a common event and has not been clearly defined, resulting in few reported cases in the literature. We discuss this phenomenon in a patient with hepatocellular carcinoma.</p> <p>Case presentation</p> <p>A 63-year-old Japanese man underwent extended right hepatic lobectomy for hepatocellular carcinoma. During his follow-up examination, a single lung metastasis and a single mediastinal lymph node metastasis were found. Trans-catheter arterial embolization was initially attempted to treat the mediastinal tumor, however this approach failed to take effect and carried risks of spinal artery embolism. External-beam irradiation, with a dose of 2.25 Gy per fraction, was performed using an antero-posterior parallel-opposed technique (total dose, 60.75 Gy). A computed tomography scan performed one month after starting radiotherapy showed a remarkable reduction of the mediastinal lymph node metastasis. In addition to this, we observed spontaneous shrinking of the lung metastasis, which was located in the right lower lobe and out of the radiation field. No chemotherapy was given during the period. There has been no recurrence of either the lung metastasis or the mediastinal lymph node metastasis during a follow-up 10 years after the radiotherapy.</p> <p>Conclusion</p> <p>We observed a rare abscopal effect in a site distant from the area of irradiation. Irradiation of the mediastinum resulted in tumor mass regression in the untreated lung tumor.</p

    Skin cancers in albinos in a teaching Hospital in eastern Nigeria - presentation and challenges of care

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Albinism is a genetic disorder characterized by lack of skin pigmentation. It has a worldwide distribution but is commoner in areas close to the equator like Nigeria. Skin cancers are a major risk associated with albinism and are thought to be a major cause of death in African albinos. Challenges faced in the care of these patients need to be highlighted in order to develop a holistic management approach with a significant public health impact. The aim of the study was to determine the pattern of skin cancers seen in Albinos, and to highlight problems encountered in their management.</p> <p>Method</p> <p>Case records of albinos managed in Imo state University teaching Hospital from June 2007 to May 2009 were reviewed. The data obtained was analyzed using descriptive statistics.</p> <p>Results and discussion</p> <p>In the period under review, albinos accounted for 67% of patients managed for primary skin cancers. There were twenty patients with thirty eight (38) lesions. Sixty one percent of the patients were below 40 years. Average duration of symptoms at presentation was 26 months. The commonest reason for late presentation was the lack of funds. Squamous cell carcinoma was the commonest histologic variant. Most patients were unable to complete treatment due to lack of funds.</p> <p>Conclusion</p> <p>Albinism appears to be the most important risk factor in the development of skin cancers in our environment. Late presentation and poor rate of completion of treatment due to poverty are major challenges.</p

    Risk Factors for Acute Leukemia in Children: A Review

    Get PDF
    Although overall incidence is rare, leukemia is the most common type of childhood cancer. It accounts for 30% of all cancers diagnosed in children younger than 15 years. Within this population, acute lymphocytic leukemia (ALL) occurs approximately five times more frequently than acute myelogenous leukemia (AML) and accounts for approximately 78% of all childhood leukemia diagnoses. Epidemiologic studies of acute leukemias in children have examined possible risk factors, including genetic, infectious, and environmental, in an attempt to determine etiology. Only one environmental risk factor (ionizing radiation) has been significantly linked to ALL or AML. Most environmental risk factors have been found to be weakly and inconsistently associated with either form of acute childhood leukemia. Our review focuses on the demographics of childhood leukemia and the risk factors that have been associated with the development of childhood ALL or AML. The environmental risk factors discussed include ionizing radiation, non-ionizing radiation, hydrocarbons, pesticides, alcohol use, cigarette smoking, and illicit drug use. Knowledge of these particular risk factors can be used to support measures to reduce potentially harmful exposures and decrease the risk of disease. We also review genetic and infectious risk factors and other variables, including maternal reproductive history and birth characteristics

    Shaping Skeletal Growth by Modular Regulatory Elements in the Bmp5 Gene

    Get PDF
    Cartilage and bone are formed into a remarkable range of shapes and sizes that underlie many anatomical adaptations to different lifestyles in vertebrates. Although the morphological blueprints for individual cartilage and bony structures must somehow be encoded in the genome, we currently know little about the detailed genomic mechanisms that direct precise growth patterns for particular bones. We have carried out large-scale enhancer surveys to identify the regulatory architecture controlling developmental expression of the mouse Bmp5 gene, which encodes a secreted signaling molecule required for normal morphology of specific skeletal features. Although Bmp5 is expressed in many skeletal precursors, different enhancers control expression in individual bones. Remarkably, we show here that different enhancers also exist for highly restricted spatial subdomains along the surface of individual skeletal structures, including ribs and nasal cartilages. Transgenic, null, and regulatory mutations confirm that these anatomy-specific sequences are sufficient to trigger local changes in skeletal morphology and are required for establishing normal growth rates on separate bone surfaces. Our findings suggest that individual bones are composite structures whose detailed growth patterns are built from many smaller lineage and gene expression domains. Individual enhancers in BMP genes provide a genomic mechanism for controlling precise growth domains in particular cartilages and bones, making it possible to separately regulate skeletal anatomy at highly specific locations in the body

    Presence of Mycoplasma fermentans in the bloodstream of Mexican patients with rheumatoid arthritis and IgM and IgG antibodies against whole microorganism

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Increasing evidence incriminates bacteria, especially <it>Mycoplasma fermentans</it>, as possible arthritogenic agents in humans. The purpose of this study was to investigate <it>M. fermentans </it>in the bloodstream of patients with rheumatoid arthritis.</p> <p>Methods</p> <p>Two hundred and nineteen blood samples from patients with rheumatoid arthritis, systemic lupus erythematosus, antiphospholipid syndrome, and healthy individuals were screened by bacterial culture and direct PCR in order to detect mycoplasmas; IgM and IgG against <it>M. fermentans </it>PG18 were also detected by ELISA and Immunoblotting assays in patients with rheumatoid arthritis and healthy individuals.</p> <p>Results</p> <p>Blood samples from patients with antiphospholipid syndrome and healthy individuals were negative for mycoplasma by culture or direct PCR. In blood samples from patients with systemic lupus erythematosus were detected by direct PCR <it>M. fermentans </it>in 2/50 (2%), <it>M. hominis </it>in 2/50 (2%) and <it>U. urealyticum </it>in 1/50 (0.5%). In patients with RA <it>M. fermentans </it>was detected by culture in 13/87 blood samples and in 13/87 by direct PCR, however, there was only concordance between culture and direct PCR in six samples, so <it>M. fermentans </it>was detected in 20/87(23%) of the blood samples from patients with RA by either culture or PCR. Antibody-specific ELISA assay to <it>M. fermentans </it>PG18 was done, IgM was detected in sera from 40/87 patients with RA and in sera of 7/67 control individuals, IgG was detected in sera from 48/87 RA patients and in sera from 7/67 healthy individuals. Antibody-specific immunoblotting to <it>M. fermentans </it>PG18 showed IgM in sera from 35/87 patients with RA and in sera from 4/67 healthy individuals, IgG was detected in sera from 34/87 patients and in sera from 5/67 healthy individuals.</p> <p>Conclusion</p> <p>Our findings show that only <it>M. fermentans </it>produce bacteremia in a high percentage of patients with RA. This finding is similar to those reported in the literature. IgM and IgG against <it>M. fermentans </it>PG18 were more frequent in patients with RA than healthy individuals.</p

    Factors affecting glomerular filtration rate, as measured by iohexol disappearance, in men with or at risk for HIV infection

    Get PDF
    Objective: Formulae used to estimate glomerular filtration rate (GFR) underestimate higher GFRs and have not been well-studied in HIV-infected (HIV(+)) people; we evaluated the relationships of HIV infection and known or potential risk factors for kidney disease with directly measured GFR and the presence of chronic kidney disease (CKD). Design: Cross-sectional measurement of iohexol-based GFR (iGFR) in HIV(+) men (n = 455) receiving antiretroviral therapy, and HIV-uninfected (HIV(-)) men (n = 258) in the Multicenter AIDS Cohort Study. Methods: iGFR was calculated from disappearance of infused iohexol from plasma. Determinants of GFR and the presence of CKD were compared using iGFR and GFR estimated by the CKD-Epi equation (eGFR). Results: Median iGFR was higher among HIV(+) than HIV(-) men (109 vs. 106 ml/min/1.73 m2, respectively, p = .046), and was 7 ml/min higher than median eGFR. Mean iGFR was lower in men who were older, had chronic hepatitis C virus (HCV) infection, or had a history of AIDS. Low iGFR (≤90 ml/min/1.73 m2) was associated with these factors and with black race. Other than age, factors associated with low iGFR were not observed with low eGFR. CKD was more common in HIV(+) than HIV(-) men; predictors of CKD were similar using iGFR and eGFR. Conclusions: iGFR was higher than eGFR in this population of HIV-infected and -uninfected men who have sex with men. Presence of CKD was predicted equally well by iGFR and eGFR, but associations of chronic HCV infection and history of clinically-defined AIDS with mildly decreased GFR were seen only with iGFR. © 2014 Margolick et al

    Rapamycin and the transcription factor C/EBPβ as a switch in osteoclast differentiation: implications for lytic bone diseases

    Get PDF
    Lytic bone diseases and in particular osteoporosis are common age-related diseases characterized by enhanced bone fragility due to loss of bone density. Increasingly, osteoporosis poses a major global health-care problem due to the growth of the elderly population. Recently, it was found that the gene regulatory transcription factor CCAAT/enhancer binding protein beta (C/EBPβ) is involved in bone metabolism. C/EBPβ occurs as different protein isoforms of variable amino terminal length, and regulation of the C/EBPβ isoform ratio balance was found to represent an important factor in osteoclast differentiation and bone homeostasis. Interestingly, adjustment of the C/EBPβ isoform ratio by the process of translational control is downstream of the mammalian target of rapamycin kinase (mTOR), a sensor of the nutritional status and a target of immunosuppressive and anticancer drugs. The findings imply that modulating the process of translational control of C/EBPβ isoform expression could represent a novel therapeutic approach in osteolytic bone diseases, including cancer and infection-induced bone loss

    Circulating mediators of inflammation and immune activation in AIDS-related non-Hodgkin lymphoma

    Get PDF
    Background: Non-Hodgkin lymphoma (NHL) is the most common AIDS-related malignancy in developed countries. An elevated risk of developing NHL persists among HIV-infected individuals in comparison to the general population despite the advent of effective antiretroviral therapy. The mechanisms underlying the development of AIDS-related NHL (A-NHL) are not fully understood, but likely involve persistent B-cell activation and inflammation. Methods: This was a nested case-control study within the ongoing prospective Multicenter AIDS Cohort Study (MACS). Cases included 47 HIV-positive male subjects diagnosed with high-grade B-cell NHL. Controls were matched to each case from among participating HIV-positive males who did not develop any malignancy. Matching criteria included time HIV+ or since AIDS diagnosis, age, race and CD4+ cell count. Sera were tested for 161 serum biomarkers using multiplexed beadbased immunoassays. Results: A subset of 17 biomarkers, including cytokines, chemokines, acute phase proteins, tissue remodeling agents and bone metabolic mediators was identified to be significantly altered in A-NHL cases in comparison to controls. Many of the biomarkers included in this subset were positively correlated with HIV viral load. A pathway analysis of our results revealed an extensive network of interactions between current and previously identified biomarkers. Conclusions: These findings support the current hypothesis that A-NHL develops in the context of persistent immune stimulation and inflammation. Further analysis of the biomarkers identified in this report should enhance our ability to diagnose, monitor and treat this disease. © 2014 Nolen et al
    corecore