Intracellular response to process optimization and impact on productivity and product aggregates for a high‐titer CHO cell process

A key goal in process development for antibodies is to increase productivity while maintaining or improving product quality. During process development of an antibody, titers were increased from 4 to 10 g/L while simultaneously decreasing aggregates. Process development involved optimization of media and feed formulations, feed strategy, and process parameters including pH and temperature. To better understand how CHO cells respond to process changes, the changes were implemented in a stepwise manner. The first change was an optimization of the feed formulation, the second was an optimization of the medium, and the third was an optimization of process parameters. Multiple process outputs were evaluated including cell growth, osmolality, lactate production, ammonium concentration, antibody production, and aggregate levels. Additionally, detailed assessment of oxygen uptake, nutrient and amino acid consumption, extracellular and intracellular redox environment, oxidative stress, activation of the unfolded protein response (UPR) pathway, protein disulfide isomerase (PDI) expression, and heavy and light chain mRNA expression provided an in‐depth understanding of the cellular response to process changes. The results demonstrate that mRNA expression and UPR activation were unaffected by process changes, and that increased PDI expression and optimized nutrient supplementation are required for higher productivity processes. Furthermore, our findings demonstrate the role of extra‐ and intracellular redox environment on productivity and antibody aggregation. Processes using the optimized medium, with increased concentrations of redox modifying agents, had the highest overall specific productivity, reduced aggregate levels, and helped cells better withstand the high levels of oxidative stress associated with increased productivity. Specific productivities of different processes positively correlated to average intracellular values of total glutathione. Additionally, processes with the optimized media maintained an oxidizing intracellular environment, important for correct disulfide bond pairing, which likely contributed to reduced aggregate formation. These findings shed important understanding into how cells respond to process changes and can be useful to guide future development efforts to enhance productivity and improve product quality.     

Assessment of effects of atomoxetine in adult patients with ADHD: consistency among three geographic regions in a response maintenance study

A previous study (Upadhyaya et al. in Eur J Psychiatry 2013b; 27:185–205) reported that adults with attention-deficit/hyperactivity disorder (ADHD) demonstrated maintenance of response for up to 25 weeks after initially responding to atomoxetine treatment. In the present report, the consistency of treatment effect across three geographic regions (Europe, United States/Canada [US/Can], and Latin America [Latin Am]) was explored. Data were analyzed from a phase 3, multicenter, randomized, double-blind, maintenance-of-response (randomized withdrawal) trial of atomoxetine versus placebo in adults with ADHD. Patients were randomized to atomoxetine (N = 266) or placebo (N = 258) for 25 weeks. Consistency assessments included the interaction test, pairwise t tests, noninferiority, and the criteria from Basic Principles on Global Clinical Trials (Ministry of Health, Labour and Welfare of Japan 2007). Atomoxetine-treated patients maintained the improved ADHD symptoms relative to placebo-treated patients on the Conners’ Adult ADHD Rating Scale Investigator-Rated: Screening Version 18-Item (CAARS-Inv:SV) total score in all three regions (atomoxetine–placebo mean difference = ?4.55, ?3.18, and ?0.07 for Europe, US/Can, and Latin Am, respectively). For the Latin Am region, the mean change in total score (0.41) was notably smaller for the placebo group than for Europe (5.87) and US/Can (4.39). Similar results were observed for the CAARS-Inv:SV hyperactivity/impulsivity and inattention subscale scores. Overall, patients maintained the response with atomoxetine treatment compared to placebo; however, the magnitude of treatment effect differed among the regions studied, being numerically higher in the EU and US/Can than Latin Am. Trial registration http://www.clinicaltrials.gov/(NCT00700427).     

Thetms2 gene as a negative selection marker in rice

A conditional negative selection marker is essential for high throughput insertional mutagenesis with any two-element transposon tagging system. Thetms2 gene encodes indoleacetic acid hydrolase (IAAH) which converts naphthaleneacetamide (NAM) to the potent auxin naphthaleneacetic acid, a phytotoxic derivative. This gene, under the control of the manopine synthase gene 2 promoter fromAgrobacterium tumefaciens and exogenously applied NAM, have been used effectively as a negative selector inAc/Ds insertional mutagenesis ofArabidopsis thaliana (Sundaresan et al., 1995). In this study we show thattms2 can also be used as a negative selector in rice. T₁ transgenic seedlings expressing thistms2 gene under the control of themas2’ promoter showed significant reduction in shoot and root growth in the presence of 5–10 μM NAM under specified growth conditions compared to plants not containing this gene.     

Use of Transformed Auxiliary Variable in Estimating the Finite Population Mean

For estimating the finite population mean Y- of the study character y, an estimator using a transformed auxiliary variable has been defined. The bias and mean-squared error (MSE) of the proposed estimator have been obtained. The regions of preference have been obtained under which it is better than usual unbiased estimator y-, the ratio estimator y-_R = y-X-/x-, Sisodia and Dwivedi (1981) estimator y-_s = y-(X- + C_x)/(x- + C_x) and Singh and Kakran (1993) estimator y-_k = y[X- + β₂(x)]/[x- + β₂(x)]. An empirical study has been carried out to demonstrate the superiority of the suggested estimator over the others.     

Phylogenetic diversity of Mesorhizobium in chickpea

Crop domestication, in general, has reduced genetic diversity in cultivated gene pool of chickpea (Cicer arietinum) as compared with wild species (C. reticulatum, C. bijugum). To explore impact of domestication on symbiosis, 10 accessions of chickpeas, including 4 accessions of C. arietinum, and 3 accessions of each of C. reticulatum and C. bijugum species, were selected and DNAs were extracted from their nodules. To distinguish chickpea symbiont, preliminary sequences analysis was attempted with 9 genes (16S rRNA, atpD, dnaJ, glnA, gyrB, nifH, nifK, nodD and recA) of which 3 genes (gyrB, nifK and nodD) were selected based on sufficient sequence diversity for further phylogenetic analysis. Phylogenetic analysis and sequence diversity for 3 genes demonstrated that sequences from C. reticulatum were more diverse. Nodule occupancy by dominant symbiont also indicated that C. reticulatum (60%) could have more various symbionts than cultivated chickpea (80%). The study demonstrated that wild chickpeas (C. reticulatum) could be used for selecting more diverse symbionts in the field conditions and it implies that chickpea domestication affected symbiosis negatively in addition to reducing genetic diversity.     

Metabolic diversity in the grains of Indian varieties of rice

The aim of the present work was to analyze metabolic diversity in 26 different indica varieties of rice grains. Seventy-six metabolites could be identified in the methanol extracts of each of the rice varieties analyzed by gas chromatography-mass spectrometry. These metabolites included 9 sugars/sugar alcohols, 17 amino acids/derivatives, 18 fatty acids, 5 free phenolic acids and 19 other organic acids, 3 phytosterols, 5 other constituents. Cluster analyses to extract information for similarity and differences in metabolites unveiled diversity in metabolite profile. Two hierarchical clusters were generated based on the metabolite contents of the rice varieties. The first cluster (cluster I) consisted of one variety only. The second cluster again segregated into four clusters (clusters II, III, IV and V). Very distinct differences were visible amongst the clusters with respect to their sugars/sugar alcohols, organic acid, amino acid and fatty acid, phenol, and sterol profiles. Metabolites determine nutritional quality, taste, aroma. This and future efforts on the metabolomic information would help biochemists and nutritionists to better understand the nutritional quality of such grains at varietal level and correlating metabolites and long term human health related issues.     

Hydrogen peroxide-scavenging enzymes and antioxidants in Echinochloa frumentacea as affected by triazole growth regulators

Paclobutrazol (PBZ)- and uniconazole (UCZ)-treated plants of Echinochloa frumentacea were shorter but had much wider leaves than untreated controls 10 days after treatment. Leaves of treated plants had a slightly higher concentration of soluble protein than the controls and exhibited enhanced activities of ascorbate peroxidase, monodehydroascorbate (MDHA) reductase, and glutathione (GSH) reductase. The triazoles did not influence the activity of dehydroascorbate (DHA) reductase. The leaves of treated plants had increased concentrations of water-soluble sulfhydryls and ascorbic acid. In contrast, the concentration of malondialdehyde (MDA), a by-product of lipid peroxidation, was lower in the leaves of treated plants than in controls. These results suggest that triazole growth regulators increased the activity of the endogenous H₂O₂-scavenging system in E. frumentacea.     

Integrated management of foliar blast through ecofriendly formulated product,Oscext-e developed from Ocimum sanctum ethanolic extract

Ocimum sanctum ethanolic extract was combined with a formulating agent (coded B+) and named Oscext-e, and the product was bioassayed under in vitro conditions against Pyricularia grisea Sacc. that causes blast disease of rice. Fungitoxic patterns such as complete inhibition, granulation in cytoplasm, reduction in germ tube length, production of thinner or coiled germ tube in conidial germination and restriction in mycelial growth registered as evident through the present studies by various experimentation confirm the fungitoxic strength of importance in impairing the successful infection of the pathogen compared with normal infection. The formulated product, Oscext-e retained its fungitoxicity until 24 months storage period in all treatments. In a separate test of the product in greenhouse and field conditions, it was not only found to effectively reduce the foliar blast of rice crop but also found comparable with a standard fungicide carbendazim.     

Do rhizobia produce cytokinins?

Two Rhizobium strains were cultured on a defined medium; one was a normal strain of the cowpea group (ANU240) while the other (IC3342) was an unusual but related strain of the same group which induced abnormal shoot development, including proliferation of lateral buds, in nodulated plants. Culture supernatants were examined for the presence of cytokinins by mass spectrometry using deuterium-labelled internal standards and by radioimmunoassay. In culture supernatants of both strains a range of cytokinins was detected and quantified, but N6-(2-isopentenyl)adenine (iP) and zeatin (Z) were the dominant cytokinins. The levels of Z and iP in supernatants of strain IC3342 were 26 and 8 times, respectively, those in supernatants of the strain ANU240. These results appear to provide the first unambiguous identifications of cytokinins in Rhizobium culture media. The cytokinin level in xylem sap of pigeonpea plants inoculated with strain IC3342 was markedly greater than that in plants inoculated with a normal nodulating strain. The abnormal proliferation of lateral buds in the former plants is probably linked to the elevation of cytokinin level in xylem sap caused by strain IC3342.