Growth Temperatures and Temperature Characteristics of Aeromonas

Six of the 13 Aeromonas hydrophila, 1 of 10 A. shigelloides, and none of 10 A. salmonicida were found to be psychrophiles. All of the rest of the strains were mesophiles. The mu values (temperature characteristics) could not be used to distinguish psychrophiles from mesophiles.     

Morphology,nutrition and physiology of Sphaerotilus discophorus

Summary By means of hay infusion-Fe(OH)₃–MnCO₃ enrichment cultures, 11 pure strains of the filamentous, sheathed bacterium, Sphaerotilus discophorus were isolated from streams, rivers and lakes. The morphology of the colonies, filaments and cells are shown in a series of photographs. The strains grew well in dilute organic media but not in many of the common bacteriological media. All strains required thiamin and biotin for growth. Glucose, mannitol, salicin, raffinose, glycerol and other compounds were suitable energy sources and peptone and casein hydrolysate were satisfactory nitrogen sources for growth. The temperature range for growth was 5–35°C and the pH range 6.0–8.6.The sudanophilic granules of S. discophorus are composed of poly--hydroxybutyric acid which may be as much as 40% of the dry weight of the cells. Growth with iron and manganese salts results in extensive deposition of oxides on these metals on the filaments. Chemical analyses of 60 hr cultures showed that the iron content of the filaments ranged from 4.25–7.10% and manganese from 1.12–1.43%, calculated on a dry weight basis. Resting cell suspensions oxidized a variety of sugars, sugar alcohols, amino acids and other compounds and concomitantly assimilated about 90% of these substrates. The properties of S. discophorus are compared with those of S. natans.Based in part on a thesis presented by the senior author in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Washington State University, 1963.     

Aluminum Toxicity: A Case Study on Tobacco (<i>Nicotiana tabacum</i> L.)

Aluminum is an abundant metal in the earth’s crust that turns out to be toxic in acidic environments. Many plants are affected by the presence of aluminum at the whole plant level, at the organ level, and at the cellular level. Tobacco as a cash crop (Nicotiana tabacum L.) is a widely cultivated plant worldwide and is also a good model organism for research. Although there are many articles on Al-phytotoxicity in the literature, reviews on a single species that are economically and scientifically important are limited. In this article, we not only provide the biology associated with tobacco Al-toxicity, but also some essential information regarding the effects of this metal on other plant species (even animals). This review provides information on aluminum localization and uptake process by different staining techniques, as well as the effects of its toxicity at different compartment levels and the physiological consequences derived from them. In addition, molecular studies in recent years have reported specific responses to Al toxicity, such as overexpression of various protective proteins. Besides, this review discusses data on various organelle-based responses, cell death, and other mechanisms, data on tobacco plants and other kingdoms relevant to these studies.     

Preferential recognition of epitopes on peroxynitrite-modified alpha-2-macroglobulin by circulating autoantibodies in rheumatoid arthritis patients

Abstract

Autoimmune responses against post-translationally modified antigens are a hallmark of several autoimmune diseases. In this work, we have studied the changes in alpha-2-macroglobulin (α₂M) upon modification by peroxynitrite. Furthermore, we have evaluated the immunogenicity of modified α₂M in experimental rabbits and rheumatoid arthritis (RA) patients. Peroxynitrite-modified α₂M showed disturbed microenvironment and altered aromatic residues under UV and fluorescence studies. Aggregation, reduction in β-sheet content, production of nitrotyrosine and shift in amide I and II bands were observed in the modified α₂M by polyacrylamide gel electrophoresis besides CD and FTIR spectroscopic analysis. The exposure of hydrophobic clusters and changes in contact positions were observed in ANS and ThT binding assays. Immunological studies using ELISA showed peroxynitrite-modified α₂M as highly immunogenic producing high titre of specific antibodies in immunized rabbits. Cross-reactivity studies revealed the polyspecificity of the elicited antibodies. Direct binding ELISA and competitive inhibition studies confirmed the presence of circulating antibodies in the sera of RA patients having high specificity towards the peroxynitrite-modified α₂M as compared to the native α₂M. Sera from healthy (normal) human subjects showed lower binding with the native and modified protein. This study confirms that peroxynitrite induces structural modifications in α₂M and makes it immunogenic. The presence of neo-antigenic determinants on modified α₂M with enhanced binding for circulating autoantibodies in RA patients could offer new possibilities for diagnosis and etiopathology of the disease.

Communicated by Ramaswamy H. Sarma     

Immunohistochemical localization of irisin in skin,eye, and thyroid and pineal glands of the crested porcupine (Hystrix cristata)

Irisin was first identified in muscle cells. We detected irisin immunoreactivity in various organs of the crested porcupine (Hystrix cristata). In the epidermis, irisin immunoreactivity was localized mainly in stratum basale, stratum spinosum and stratum granulosum layers; immunoreactivity was not observed in the stratum corneum. In the dermis, irisin was found in the external and internal root sheath, cortex and medulla of hair follicles, and in sebaceous glands. Irisin immunoreactivity was found in the neural retina and skeletal muscle fibers associated with the eye. The pineal and thyroid glands also exhibited irisin immunoreactivity.     

Single versus multiple bioreactor scale-up: economy for high-value products

The economy of scaling-up a bioreactor by increasing the number of units was investigated with respect to an integrated flowsheet. For the production of t-PA from animal cells, a base case flowsheet using a single large bioreactor was compared to a multiple bioreactor case. Simulation of the complete flowsheets for the two cases showed that a multiple bioreactor approach to scale-up increases the return of investment (ROI) of the base process by 122%. This enormous increase in ROI results from the smaller size of the downstream units compared to the base case, since downstream processing accounts for about 80% of the total cost for high value products like t-PA. Proper scheduling of the downstream units allowed sharing of the equipment by the bioreactors. A breakdown of the equipment purchase cost showed that cost related to cell culture equipment increased from 14% for the base case to about 37% for the multiple bioreactor case. The contribution from chromatography columns to the total equipment purchase cost, on the other hand, decreased from 52 to 33%.     

Ultrasound imaging in an experimental model of fatty liver disease and cirrhosis in rats

Background

Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries. Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. The first successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.

Results

This study demonstrates that atypical scrapie has distinct clinical, pathological and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.

Conclusions

Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage.     

Fracture prevention in COPD patients; a clinical 5-step approach

Although osteoporosis and its related fractures are common in patients with COPD, patients at high risk of fracture are poorly identified, and consequently, undertreated. Since there are no fracture prevention guidelines available that focus on COPD patients, we developed a clinical approach to improve the identification and treatment of COPD patients at high risk of fracture. We organised a round-table discussion with 8 clinical experts in the field of COPD and fracture prevention in the Netherlands in December 2013. The clinical experts presented a review of the literature on COPD, osteoporosis and fracture prevention. Based on the Dutch fracture prevention guideline, they developed a 5-step clinical approach for fracture prevention in COPD. Thereby, they took into account both classical risk factors for fracture (low body mass index, older age, personal and family history of fracture, immobility, smoking, alcohol intake, use of glucocorticoids and increased fall risk) and COPD-specific risk factors for fracture (severe airflow obstruction, pulmonary exacerbations and oxygen therapy). Severe COPD (defined as postbronchodilator FEV₁ < 50% predicted) was added as COPD-specific risk factor to the list of classical risk factors for fracture. The 5-step clinical approach starts with case finding using clinical risk factors, followed by risk evaluation (dual energy X-ray absorptiometry and imaging of the spine), differential diagnosis, treatment and follow-up. This systematic clinical approach, which is evidence-based and easy-to-use in daily practice by pulmonologists, should contribute to optimise fracture prevention in COPD patients at high risk of fracture.