Erythropoietin production by fetal mouse liver cells in response to hypoxia and adenylate cyclase stimulation

This study was done to investigate aspects of control of extrarenal erythropoietin (Ep) production. To this end we studied the effects of three stimuli of renal Ep production in the adult, i.e. hypoxia, cobalt, and activation of adenylate cyclase on Ep generation by cultured fetal mouse liver cells. The fetal liver was taken as a model for extrarenal Ep production because this organ is considered the predominant site of extrarenal Ep production. We found that Ep production by the cells increased as the oxygen concentration was decreased in the incubation atmosphere from 20% to 1%. Cobalt (10(-4)-10(-5) M) had no effect on Ep production. Activation of adenylate cyclase by forskolin (10(-5) M) or isoproterenol (10(-5) M) greatly enhanced Ep production. These findings indicate that the Ep-stimulating effect of cobalt is specific for the kidney. However, oxygen depletion and activation of adenylate cyclase seem to be more general stimuli in Ep-producing cells. Furthermore we found that Ep production in hypoxia correlated with lactate formation in the cultured liver cells. This finding suggests that Ep production in fetal livers under hypoxic conditions parallels the shift from aerobic to anaerobic cellular energy metabolism

Investigation of virus occurrence in different tissues throughout the year and sequence variability of Apple stem pitting virus

The occurrence of Apple stem pitting virus (ASPV) isolate PB 66 in three different types of tissue of four different apple varieties throughout the year was determined. Reliable virus detection in phloem tissue was observed in all four apple varieties investigated, at all sampling dates during the year. The complete nucleotide sequence of ASPV isolate PB 66 was determined and compared to ASPV isolate PA 66. The isolates show 80 % sequence identity. Comparison of the ASPV PA 66 coat protein amino acids sequence with 16 other ASPV isolates from different hosts revealed an insertion event of 18 amino acids.Keywords: Apple stem pitting virus, Foveavirus, Flexivirida

Transmission of Little cherry virus -1 (LChV-1) by Cuscuta europea to herbaceous host plants

Little cherry virus-1 (LChV-1) was transmitted from infected Prunus avium F12 rootstocks by Cuscuta europea to Nicotiana occidentalis ‘37B’. Transmission of the virus was confirmed by RT-PCR analysis of total nucleic acid extracts from dodder and N. occidentalis. Symptoms consisted of curled leaves, reddening of leaf margins and veins, and plant decline. In parallel attempts virus transmission was not successful for LChV-2. Propagation of LChV-1 by mechanical transmission on N. occidentalis failed, however the virus was transferred serially by grafting

A new member of the family Reoviridae may contribute to severe crumbly fruit in red raspberry, Rubus idaeus ‘Meeker’

AbstractA virus induced crumbly fruit disease of considerable importance in ‘Meeker’ and other cultivars of red raspberry has been observed in northern Washington, USA, and British Columbia, Canada and to a lesser extent in the Willamette Valley of Oregon. Raspberry bushy dwarf virus (RBDV), a pollen-borne virus, has been considered the causal agent of the disease. However, dsRNA extractions from raspberry plants exhibiting severe crumbly fruit in northern Washington revealed multiple bands in addition to those corresponding to RBDV (5.5kb and 2.2kb). Sequence analyses of these dsRNAs showed the presence of two additional viruses. One has significant amino acid identity to proteins encoded by Rice ragged stunt virus (RRSV), a ten-segmented dsRNA Oryzavirus that belongs to the family Reoviridae. Thus far, all dsRNA segments, except the one that corresponds to S6 of RRSV, have been fully sequenced and found to have characteristic features of other plant reoviruses genomes. In addition, Raspberry leaf mottle virus (RLMV), a recently characterized member of the Closteroviridae, has also been identified from raspberries with severe crumbly fruit. These findings along with the lack of severe crumbly fruit symptoms in ‘Meeker’ red raspberry singly infected with RBDV in Oregon, suggest the existence of a novel virus complex associated with severe crumbly fruit in red raspberries. The complex may involve RBDV, RLMV and/or this new reovirus, provisionally named Raspberry latent virus (RpLV). Keywords: Raspberry crumbly fruit, Raspberry bushy dwarf virus, Raspberry leaf mottle virus, Raspberry leaf spot virus, plant reoviruses

Sample Preparation for N-Glycosylation Analysis of Therapeutic Monoclonal Antibodies by Electrophoresis

There are a considerable number of biopharmaceuticals that have been approved for clinical use in the past decade. Over half of these new generation drugs are glycoproteins, such as monoclonal antibodies or other recombinant glycoproteins, which are mostly produced in mammalian cell lines. The linked carbohydrate moieties affect not only their physicochemical properties and thermal stability but also crucial features like receptor-binding activity, circulating half-life, as well as immunogenicity. The structural diversity of these attached glycans can be manifested in altered monosaccharide composition and linkages/positions among the monosaccharide building blocks. In addition, as more and more biosimilar products hit the market, understanding the effects of their glycosylation modifi cation has become a recent target in effi cacy and safety issues. To ensure consistent quality of these products, glycosylation profi les have to be monitored and controlled in all steps of the manufacturing process, i.e., from clone selection to lot release. In this paper, we describe some of the recently introduced and commonly used sample preparation techniques for capillary electrophoresis (CE)-based profi ling and structural elucidation of N-glycans. The presented pro- tocols include protein A affi nity partitioning of monoclonal antibodies (mAbs), enzymatic release of the N-linked glycans, labeling of the liberated carbohydrates, reaction mixture purifi cation techniques to remove the excess labeling reagent, and high-resolution and rapid capillary electrophoresis-laser-induced fl uorescence (CE-LIF)-based profi ling of the labeled and purifi ed N-glycans

The prognostic value of the hypoxia markers CA IX and GLUT 1 and the cytokines VEGF and IL 6 in head and neck squamous cell carcinoma treated by radiotherapy ± chemotherapy

BACKGROUND: Several parameters of the tumor microenvironment, such as hypoxia, inflammation and angiogenesis, play a critical role in tumor aggressiveness and treatment response. A major question remains if these markers can be used to stratify patients to certain treatment protocols. The purpose of this study was to investigate the inter-relationship and the prognostic significance of several biological and clinicopathological parameters in patients with head and neck squamous cell carcinoma (HNSCC) treated by radiotherapy ± chemotherapy. METHODS: We used two subgroups of a retrospective series for which CT-determined tumoral perfusion correlated with local control. In the first subgroup (n = 67), immunohistochemistry for carbonic anhydrase IX (CA IX) and glucose transporter-1 (GLUT-1) was performed on the pretreatment tumor biopsy. In the second subgroup (n = 34), enzyme linked immunosorbent assay (ELISA) was used to determine pretreatment levels of the cytokines vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in serum. Correlation was investigated between tumoral perfusion and each of these biological markers, as well as between the markers mutually. The prognostic value of these microenvironmental parameters was also evaluated. RESULTS: For CA IX and GLUT-1, the combined assessment of patients with both markers expressed above the median showed an independent correlation with local control (p = 0.02) and disease-free survival (p = 0.04) with a trend for regional control (p = 0.06). In the second subgroup, IL-6 pretreatment serum level above the median was the only independent predictor of local control (p = 0.009), disease-free survival (p = 0.02) and overall survival (p = 0.005). CONCLUSION: To our knowledge, we are the first to report a link in HNSCC between IL-6 pretreatment serum levels and radioresistance in vivo. This link is supported by the strong prognostic association of pretreatment IL-6 with local control, known to be the most important parameter to judge radiotherapy responses. Furthermore, the combined assessment of CA IX and GLUT-1 correlated independently with prognosis. This is a valuable indication that a combined approach is important in the investigation of prognostic markers

Neonatal erythropoiesis and subsequent anemia in HIV-positive and HIV-negative Zimbabwean babies during the first year of life: a longitudinal study

BACKGROUND: Anemia is common in HIV infection and independently associated with disease progression and mortality. The pathophysiology of HIV-related anemia is not well understood especially in infancy. METHODS: We conducted a longitudinal cohort study nested within the Zimbabwe Vitamin A for Mothers and Babies Project. We measured hemoglobin, erythropoietin (EPO), serum transferrin receptor (TfR) and serum ferritin at 6 weeks, 3 and 6 months of age and hemoglobin at 9 and 12 months in 3 groups of randomly selected infants: 136 born to HIV-negative mothers, and 99 born to HIV-positive mothers and who were infected themselves by 6 weeks of age, and 324 born to HIV-positive mothers but who did not become infected in the 6 months following birth. RESULTS: At one year of age, HIV-positive infants were 5.26 (adjusted odds ratio, P < 0.001) times more likely to be anemic compared to HIV-negative infants. Among, HIV-negative infants, EPO was or tended to be inversely associated with hemoglobin and was significantly positively associated with TfR throughout the first 6 months of life; TfR was significantly inversely associated with ferritin at 6 months; and EPO explained more of the variability in TfR than did ferritin. Among infected infants, the inverse association of EPO to hemoglobin was attenuated during early infancy, but significant at 6 months. Similar to HIV-negative infants, EPO was significantly positively associated with TfR throughout the first 6 months of life. However, the inverse association between TfR and ferritin observed among HIV-negative infants at 6 months was not observed among infected infants. Between birth and 6 months, mean serum ferritin concentration declined sharply (by ~90%) in all three groups of babies, but was significantly higher among HIV-positive compared to HIV-negative babies at all time points. CONCLUSION: HIV strongly increases anemia risk and confounds interpretation of hematologic indicators in infants. Among HIV-infected infants, the EPO response to anemia is attenuated near the time of infection in the first weeks of life, but normalizes by 6 months

Haemoglobin mass and running time trial performance after recombinant human erythropoietin administration in trained men

&lt;p&gt;Recombinant human erythropoietin (rHuEpo) increases haemoglobin mass (Hbmass) and maximal oxygen uptake (v˙ O2 max).&lt;/p&gt; &lt;p&gt;Purpose: This study defined the time course of changes in Hbmass, v˙ O2 max as well as running time trial performance following 4 weeks of rHuEpo administration to determine whether the laboratory observations would translate into actual improvements in running performance in the field.&lt;/p&gt; &lt;p&gt;Methods: 19 trained men received rHuEpo injections of 50 IUNkg21 body mass every two days for 4 weeks. Hbmass was determined weekly using the optimized carbon monoxide rebreathing method until 4 weeks after administration. v˙ O2 max and 3,000 m time trial performance were measured pre, post administration and at the end of the study.&lt;/p&gt; &lt;p&gt;Results: Relative to baseline, running performance significantly improved by ,6% after administration (10:3061:07 min:sec vs. 11:0861:15 min:sec, p,0.001) and remained significantly enhanced by ,3% 4 weeks after administration (10:4661:13 min:sec, p,0.001), while v˙ O2 max was also significantly increased post administration (60.765.8 mLNmin21Nkg21 vs. 56.066.2 mLNmin21Nkg21, p,0.001) and remained significantly increased 4 weeks after rHuEpo (58.065.6 mLNmin21Nkg21, p = 0.021). Hbmass was significantly increased at the end of administration compared to baseline (15.261.5 gNkg21 vs. 12.761.2 gNkg21, p,0.001). The rate of decrease in Hbmass toward baseline values post rHuEpo was similar to that of the increase during administration (20.53 gNkg21Nwk21, 95% confidence interval (CI) (20.68, 20.38) vs. 0.54 gNkg21Nwk21, CI (0.46, 0.63)) but Hbmass was still significantly elevated 4 weeks after administration compared to baseline (13.761.1 gNkg21, p&#60;0.001).&lt;/p&gt; &lt;p&gt;Conclusion: Running performance was improved following 4 weeks of rHuEpo and remained elevated 4 weeks after administration compared to baseline. These field performance effects coincided with rHuEpo-induced elevated v˙ O2 max and Hbmass.&lt;/p&gt