Phenotyping of circulating CD8⁺ T cell subsets in human cutaneous leishmaniasis

Recovery from CL is usually accompanied with long-lasting protection and induction of strong immune response. The phenotypes, generation and maintenance of central (=T_CM) and effector (=T_EM) memory T cell subsets in human leishmaniasis are not well known. Profile of T cell subsets were analyzed on peripheral CD8⁺ T cells from volunteers with history of cutaneous leishmaniasis (HCL).In HCL and control groups, mean frequencies of CCR7⁺CD45RA⁺CD8⁺ naïve and CCR7^?CD45RA^?CD8⁺ T_EM cells were higher than other subsets before culture, but after stimulation with soluble Leishmania antigen, the frequency of naïve T cells was significantly decreased and the frequency of T_EM cells was significantly increased. T_EM phenotype composed the highest portion of proliferating Carboxy Fluorescein diacetate Succinimidyl Ester (CFSE)-dim population which was significantly higher in HCL volunteers than in control group. Stimulation of isolated CD8⁺ memory T cells, but not naïve T cells, from HCL volunteers induced a significantly higher IFN-γ production compared with that of healthy controls. Intracellular IFN-γ staining provided the same result.Memory population is shown to be responsible for Leishmania-induced IFN-γ production. Leishmania-reactive proliferating T_EM cells were identified as the most frequent subset which may play a role in recall immune response and protection against Leishmania infection.     

Fish entrapment in the seawater intake of a power plant at Karachi coast

Synopsis The study deals with the entrapment of fishes in the intake of Karachi Nuclear Power Plant. A total of 62 species of marine fishes belonging to 43 genera were observed entrapped in the seawater intake. Therapon puta, Liza waigiensis, Abudefduf septemfasciatus, and Lagoceptalus inermis were the most common. Mass mortalities of the juveniles of Sardinella sindensis were recorded in September and October of 1974, 1975, and 1977. Commercially important fishes such as sardines, mullets and anchovies, were entrapped in the intake of the power plant in considerable numbers at various times of the year. The majority of fishes removed from the screen washes of the power plants were killed by impingement.     

The relationship between hydrophobicity and interfacial tension of proteins.

Charge-free hydrophobic gels of Hjerten et al. (Hjerten, S., Rosengren, J. and Pahlman, S. (1974) J. Chromatogr. 101, 281--288) were used for hydrophobic affinity chromatography. The effective hydrophobicity of proteins was expressed as their retention volumes from columns of butylepoxy- and hexylepoxy-Sepharose 4B. The effective hydrophobicity was also estimated by a partition method of Shanbhag and Axelsson ((1975) Eur. J. Biochem. 60, 17--22) from the partition coefficients of proteins between two phases, poly (ethylene glycol) and dextran. The former contained a hydrophobic ligand, palmitate. A close correlation was observed between the hydrophobicities determined by the two methods. However, no significant relationship was observed between these effective hydrophobicities and the average hydrophobicity of Bigelow ((1967) J. Theoret. Biol. 16, 187--211) that was calculated from the total amino acid composition of each protein. The interfacial tensions at the 0.2% protein/corn oil interface revealed negative correlations with the effective hydrophobicities determined by both methods indicating lower interfacial tensions with more hydrophobic proteins.     

A study of D‐lactate and extracellular methylglyoxal production in lactate Re‐Utilizing CHO cultures

In large‐scale mammalian cell culture, the key toxic by‐products assessed and monitored are lactate and ammonia. Often no distinction between the two isoforms of lactate is made. Here, we present profiles of both D ‐ and L ‐lactate. D ‐Lactate is the end molecule of the methylglyoxal pathway. D ‐Lactate unlike L ‐lactate is not re‐utilized, and although during normal culture time frames it represents one‐tenth of total lactate, during lactate re‐use it represents nearly 35%. This indicates significant carbon flow through pathways not associated with primary metabolites. We have observed that the behavior of D ‐lactate is radically different from that of L ‐lactate with the level of one isoform changing, whilst the concentration of the other remains constant. This is an example of an alternate carbon flow pathway containing metabolic intermediates that may potentially have a detrimental effect on cells. The activity of the methylglyoxal pathway when measured as a proportion of glucose consumption in this study far exceeds any previously reported. This highlights the potential importance of “non‐primary” metabolisms to long lifespan mammalian fermentation practices. Biotechnol. Bioeng. 2010;107: 182–189. © 2010 Wiley Periodicals, Inc.     

Effect of pH and loading manner on the start-up period of peat biofilter degrading xylene and toluene mixture

Laboratory-scale biofilters packed with a mixture of peat, bark and wood were used for xylene and toluene removal from waste air. Two kinds of peat, which differed in the resulting pH of the leachate, were chosen for degradation of the pollutants by a mixed culture. Using peat with the lower pH value, the feasibility of single and multiple pollutant loading during the start-up period and augmentation withPseudomonas putida strains were characterized. The lower pH value of the bed resulted in higher efficiency of toluene degradation from the mixture of pollutants. At higher pH values better degradation of both pollutants was achieved. Regarding the manner of loading during the start-up period, the best results were obtained using toluene as a single pollutant in the initial phase of operation.Pseudomonas strains demonstrated a high ability to degrade both pollutants; more efficient degradation for xylene than for toluene was observed at high loading rates.