Phenotype and function of human natural killer cells purified by using a clinical-scale immunomagnetic method

Infection, disease relapse, graft failure, and graft-versus-host disease (GVHD) are significant adverse events associated with allogeneic bone marrow transplantation. Donor natural killer (NK) cells may be an ideal cell type for prevention or treatment of all these adverse events. Therefore, we investigated the phenotype and function of human NK cells purified by using a clinical-scale immunomagnetic method. We found that the NK cell purification procedures did not adversely affect the expression of killer cell immunoglobulin-like receptors, adhesion molecules, intracellular cytokines, perforin, and granzyme B. Purified NK cells had extensive proliferative capacity and potent antitumor activity when assessed using an immunodeficient mouse model. While all mice transplanted with unpurified mononuclear cells developed GVHD, none of the mice transplanted with purified NK cells did. NK cells were highly susceptible to lysis by antithymocyte globulin (ATG), whereas G-CSF had a minimal effect on their natural cytotoxicity. These results support future clinical investigation of the use of purified NK cells for adoptive immunotherapy in the absence of ATG.     

Diversity of genome structure in Salmonella enterica serovar Typhi populations

The genomes of most strains of Salmonella and Escherichia coli are highly conserved. In contrast, all 136 wild-type strains of Salmonella enterica serovar Typhi analyzed by partial digestion with I-CeuI (an endonuclease which cuts within the rrn operons) and pulsed-field gel electrophoresis and by PCR have rearrangements due to homologous recombination between the rrn operons leading to inversions and translocations. Recombination between rrn operons in culture is known to be equally frequent in S. enterica serovar Typhi and S. enterica serovar Typhimurium; thus, the recombinants in S. enterica serovar Typhi, but not those in S. enterica serovar Typhimurium, are able to survive in nature. However, even in S. enterica serovar Typhi the need for genome balance and the need for gene dosage impose limits on rearrangements. Of 100 strains of genome types 1 to 6, 72 were only 25.5 kb off genome balance (the relative lengths of the replichores during bidirectional replication from oriC to the termination of replication [Ter]), while 28 strains were less balanced (41 kb off balance), indicating that the survival of the best-balanced strains was greater. In addition, the need for appropriate gene dosage apparently selected against rearrangements which moved genes from their accustomed distance from oriC. Although rearrangements involving the seven rrn operons are very common in S. enterica serovar Typhi, other duplicated regions, such as the 25 IS200 elements, are very rarely involved in rearrangements. Large deletions and insertions in the genome are uncommon, except for deletions of Salmonella pathogenicity island 7 (usually 134 kb) from fragment I-CeuI-G and 40-kb insertions, possibly a prophage, in fragment I-CeuI-E. The phage types were determined, and the origins of the phage types appeared to be independent of the origins of the genome types.     

Pre-electroconvulsive shock administration of calcium channel blockers reduces retrograde amnesia induced by ECS

Effect of pre-electroconvulsive shock (ECS) administration of calcium channel blockers (CCBs) like verapamil, diltiazem, nifedipine, nimodipine, flunarizine and cinnarizine on retrograde amnesia induced by ECS was examined using passive avoidance paradigm in rats. The groups (Gr 1-7) of adult, male Wistar rats received true ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; ip) and other groups (Gr 8-14) received sham ECS with CCBs (5mg/kg; i.p) or vehicle (10 ml/kg; i.p). The anti-amnestic activity of CCBs were evaluated using the passive avoidance paradigm in rats. Results showed that, the baseline latencies for all the groups did not differ significantly. Rats receiving true ECS produced significantly lower latencies. There was increase in the post ECS step through latencies of the rats administered CCBs before ECS. Therefore, pre-ECS administration of calcium channel blockers might reduce retrograde amnesia produced by ECS without altering seizure duration.     

Determinants of antileukemia effects of allogeneic NK cells

In HLA-nonidentical bone marrow transplantation, we studied the characteristics of donor NK cells, recipient leukemia cells, and the cytokine environment that predict the antileukemia effects of allogeneic NK cells. We found that the risk of relapse in pediatric patients with hematologic malignancies was best predicted by a model taking into consideration the presence of inhibitory killer cell Ig-like receptors (KIRs) on the donor's NK cells and the absence of corresponding KIR ligand in the recipient's HLA repertoire (a receptor-ligand model). The risk of relapse was prognosticated less precisely by the Perugia donor-recipient KIR ligand-ligand mismatch model or by a natural cytotoxicity model. In contrast to the ligand-ligand model, we found that the new receptor-ligand model was accurate when analysis was applied to patients with lymphoid malignancy. These findings corroborate our observations that the recipient's KIR repertoire, which was derived from highly purified, HLA-disparate CD34+ cells, resumed a donor-specific pattern within 3 mo of transplantation, but did not correlate evidently with the donor or recipient ligand repertoire. In an in vitro assay and an in vivo mouse model, human NK cell cytotoxicity toward human leukemia cells with 11q23 chromosomal rearrangement increased with the number of receptor-ligand mismatch pairs or prestimulation with IL-12 and IL-18. These findings provide new insights into the determinants of antileukemia effects of allogeneic NK cells and therapeutic strategies.     

Resource partitioning and interspecific interactions among sympatric rain forest arboreal mammals of the Western Ghats, India

Resource partitioning in a community of diurnal arboreal mammalsconsisting of the lion-tailed macaque Macaca silenus, bonnetmacaque (BM) Macaca radiata, Nilgiri langur Semnopithecus johnii,and the Indian giant squirrel Ratufa indica of the Western Ghats,southern India, was studied. Differences in their diet, verticalstratification, food resource niche breadth, niche overlap,and behavioral interactions were examined. Resource partitioningwas through differential habitat use, resource use, and verticalstratification. Of the four species, the BM was not a residentspecies and made frequent forays into evergreen forest fromthe adjacent deciduous forest during the flowering season ofCullenia exarillata and fruiting season of Ficus microcarpa.The macaques had narrower niches, and the langur and the squirrelhad wider niches. Niche overlap was highest between the twomacaques. Overlap among the study species was particularly pronouncedduring the flowering of C. exarillata. There was significantcorrelation between niche overlap and intolerance among thestudy species. Certain species pairs showed little or no mutualintolerance despite high overlap. Cooperative interactions suchas alarm calls occurred more frequently among the resident species.Interaction matrices revealed an underlying pattern of interspecificdominance hierarchy, with the BM dominating over the other threespecies. Our study suggests that the BM do not coexist withthe other three because of high overlap with its congener andlow occurrence of cooperative interactions.     

Ecoinformatics using wireless sensor networks: An overview

Wireless sensor networks have the potential to become significant subsystems of ecological experiment. Sensor networks consist of large number of tiny sensor nodes, all of which have sensing capabilities. These networks allow coordinated signal detection, monitoring, and tracking to enable sensor nodes to simultaneously capture geographically distinct measurements. Sensor nodes do not require predetermined positioning making such networks especially useful for applications in remote, inhospitable environments. In this paper we have tried to see the various ecological experimental scenarios, and how wireless sensor networks can be used in that field. One of the most challenging bottlenecks in the usage of wireless sensor networks in large scale experiments is the energy constraint. Various routing protocols which have tried to optimize the energy usage are also studied in the paper.     

Calreticulin transacetylase catalyzed modification of the TNF-α mediated pathway in the human peripheral blood mononuclear cells by polyphenolic acetates

Polyphenols, coumarin (1,2-benzopyrone) and chromone (1,4-benzopyrone), are naturally occurring constituent of variety of plant species. They have attracted immense interest because of their diverse pharmacological activities. Not much was known about biological activities of acetyl derivative (polyphenolic acetates) of parent polyphenols. In previous investigations, we have conclusively established calreticulin transacetylase catalyzed activation of endothelial nitric oxide synthase (eNOS) by polyphenolic acetates. In the present work, calreticulin transacetylase of human peripheral blood mononuclear cells was characterized with respect to specificity for various polyphenolic acetates and its role in the activation of TNF-α induced nitric oxide synthase (iNOS). Peripheral blood mononuclear cells incubated with a model polyphenolic acetate, 7,8-diacetoxy-4-methylcoumarin (DAMC), along with l-arginine caused activation of NOS. The incubation of peripheral blood mononuclear cells with TNF-α and DAMC resulted in increased production of NO as compared to TNF-α alone. This increased NO production was attenuated by l-Nω-nitro-l-arginine methyl ester (l-NAME), a well known non-specific inhibitor of NOS, and 1400W (N-[3-(aminomethyl) benzyl] acetamidine), a specific inhibitor of human iNOS. These results substantiate the CRTAase catalyzed activation of iNOS. Further, expression of NOS isoforms by semi-quantitative PCR and real-time RT-PCR confirms the preponderance of iNOS in TNF-α treated peripheral blood mononuclear cells over the untreated one. It was also observed that polyphenolic acetates inhibit TNF-α mediated release of IL-6 from peripheral blood mononuclear cells.     

Mineralization of 4-aminobenzenesulfonate (4-ABS) by Agrobacterium sp. strain PNS-1

A bacterial strain, PNS-1, isolated from activated sludge, could utilize sulphanilic acid (4-ABS) as the sole organic carbon and energy source under aerobic conditions. Determination and comparison of 16S r DNA sequences showed that the strain PNS-1 is closely related to the species of Agrobacterium genus. Growth on 4-ABS was accompanied with ammonia and sulfate release. TOC results showed complete mineralization of sulphanilic acid. This strain was highly specific for 4-ABS as none of the sulphonated aromatics used in the present study including other ABS isomers were utilized. Strain PNS-1 could, however, utilize all the tested monocyclic aromatic compounds devoid of a sulfonate group. No intermediates could be detected either in the growth phase or with dense cell suspensions. Presence of chloramphenicol completely inhibited 4-ABS degradation by cells pregrown on succinate, indicating that degradation enzymes are inducible. No plasmid could be detected in the Agrobacterium sp. Strain PNS-1 suggesting that 4-ABS degradative genes may be chromosomal encoded.     

Beta-adrenoceptor agonist treatment reverses denervation atrophy with augmentation of collagen proliferation in denervated mice gastrocnemius muscle

Daily oral administration of isoproterenol hydrochloride (60 mg/kg body weight; for 30 days) a beta-receptor agonist to normal innervated and denervated adult male Swiss albino mice confirmed its ability to induce skeletal muscle hypertrophy and reverse denervation atrophy respectively. Measurement of total tissue proteins and dry muscle mass showed 15-17% increase with 6% rise of hypertrophy index in gastrocnemius muscle. Hydroxyproline assay employed to measure the total tissue collagen exhibited 45% increase in collagen in normal innervated gastrocnemius muscle in response to beta agonist treatment. beta-adrenoceptor agonist ameliorated denervation atrophy along with further increase in collagen content of denervated gastrocnemius muscle.