Protein carbonyls are widely analysed as a measure of protein oxidation. Several different methods exist for their determination. A previous study had described orders of magnitude variance that existed when protein carbonyls were analysed in a single laboratory by ELISA using different commercial kits. We have further explored the potential causes of variance in carbonyl analysis in a ring study. A soluble protein fraction was prepared from rat liver and exposed to 0, 5 and 15 min of UV irradiation. Lyophilised preparations were distributed to six different laboratories that routinely undertook protein carbonyl analysis across Europe. ELISA and Western blotting techniques detected an increase in protein carbonyl formation between 0 and 5 min of UV irradiation irrespective of method used. After irradiation for 15 min, less oxidation was detected by half of the laboratories than after 5 min irradiation. Three of the four ELISA carbonyl results fell within 95% confidence intervals. Likely errors in calculating absolute carbonyl values may be attributed to differences in standardisation. Out of up to 88 proteins identified as containing carbonyl groups after tryptic cleavage of irradiated and control liver proteins, only seven were common in all three liver preparations. Lysine and arginine residues modified by carbonyls are likely to be resistant to tryptic proteolysis. Use of a cocktail of proteases may increase the recovery of oxidised peptides. In conclusion, standardisation is critical for carbonyl analysis and heavily oxidised proteins may not be effectively analysed by any existing technique.

The genome of the nitrogen-fixing soil bacterium Sinorhizobium meliloti does not possess genes for bioremediation of aromatic pollutants. It has the well-known ability to interact specifically with the leguminous alfalfa plant, Medicago sativa. Our previous work has shown enhanced degradation of the nitroaromatic compound 2,4-dinitrotoluene (DNT) when a plasmid containing degradative genes was introduced in it. In this study we report molecular evidence of the transfer of a polychlorinated biphenyl (PCB)-biodegradative plasmid pE43 to S. meliloti strain USDA 1936. Several standard analytical tests and plant growth chamber studies were conducted to test the ability of S. meliloti to degrade 2',3,4-PCB congener. Alfalfa plant alone was able to degrade 30% of PCBs compared with control. No enhanced dechlorination was noted when alfalfa plant was grown with wild-type S. meliloti, and when alfalfa plant was grown with the S. meliloti electrotransformants (genetically modified) dechlorination of PCBs was more than twice that when alfalfa plant was grown with wild-type S. meliloti. When alfalfa plant was grown with uncharacterized mixed culture (containing nodule formers), almost equally significant PCB degradation was observed. The significance of this work is that the naturally occurring nitrogen-fixing soil bacterium S. meliloti (genetically modified) has the ability to enhance fertility of soil in association with the leguminous alfalfa plant while simultaneously enhancing bioremediation of PCB-contaminated soils. Enhanced bioremediation of PCB and robust alfalfa plant growth was also noted when uncharacterized mixed cultures containing alfalfa plant nodule formers were used.

Background In Sudan, the number of End Stage Renal Disease (ESRD) patients receiving hemodialysis is growing. Patients and their families incur a high out of pocket expenditure provided that hemodialysis treatment is expensive. There is limited data about out of pocket spending on hemodialysis in the country. This study aims to explore patients’ out-of-pocket expense on direct medical and non-medical goods and services and to which extent they can be predicted from socio-demographic characteristics, health insurance status, comorbidity, and accommodation change. Methods This is a cross-sectional descriptive study conducted in Ibn Sina Hospital. One hundred and thirty patients undergo regular two hemodialysis sessions were randomly selected. Results Among the study participants the median of the overall total out-of-pocket (direct medical and direct non- medical) spending per patient per year was found to be US$ 3859.1(Inter quartile Range(IQR): 2298.1- 6261.1). As for the medians out-of-pocket expenditure on direct medical and non-medical costs, they were found to be US$2327.6 (IQR 1421.5-3804.8) and US$ 1096 (IQR 715.2-2345.2), respectively. The direct medical expenditure (355586US$) accounted for (60%) of the overall total expenses. Medications and investigations were the primary drivers of direct medical spending. Higher out-of-pocket expenditure rates were found among those with one or more of these merits; uninsured patients, Patient with comorbidity, female gender, and over 40 years age. The multivariate analysis showed that the significant predictors of direct medical expenditure were health insurance, comorbid conditions, while the predictors for direct non-medical expenditure were accommodation change and gender. Conclusion Results of this study provide a better understanding of out-of-pocket spending on direct medical and non-medial spending among hemodialysis patients within the context of Sudan. Furthermore, it provides descriptive information on patients’ characteristics that are found to be associated with increased out of pocket expenditure among hemodialysis population. Further research needed in this area.

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