The array of cytokines produced by T cells in effector sites is a primary means by which these cells mediate host defense. It is well recognized that cloned T cells are heterogeneous with regard to cytokine synthesis and, thus, in their ability to mediate specific immune responses, but the extent to which the patterns of cytokine secretion observed in cloned cells reflect actual populations of memory/effector T cells existing in vivo is largely unknown. Here, we report our findings using a multiparameter flow cytometric assay that allows simultaneous determination of an individual T-cell' ability to produce multiple cytokines and its phenotype after only short (4 to 8 hours) in vitro incubation with an activating stimulus and the secretion inhibitor Brefeldin A. This assay shows a rapid accumulation of interleukin-2 (IL-2), IL-4, and gamma-interferon (gamma-IFN) in the cytoplasm of CD4+ cells after stimulation with either accessory cell- independent (phorbol 12-myristate 13-acetate [PMA] + ionomycin [I]) or accessory cell-dependent (staphylococcal enterotoxins [SE] A and B) T- cell-activating stimuli. Further analysis showed that production of gamma-IFN and IL-4 is predominantly, if not exclusively, restricted to the CD45ROhigh memory/effector T-cell subset, whereas IL-2 may be produced by both the CD45ROhigh and CD45ROlow subsets. Simultaneous determination of IL-2 and gamma-IFN production among CD45ROhigh/CD4+ T cells showed distinct subsets that produce each of these cytokines alone (an average of 30% for IL-2 alone, 8% for gamma-IFN alone), both (16%), or neither (46%). Similar analyses with the small IL-4-producing memory/effector T-cell subset (only 4.3% of total CD4+/CD45ROhigh T cells) showed that an average of 51% of these IL-4-producing cells also synthesize average of 51% of these IL-4-producing cells also synthesize IL-2, 23% synthesize only IL-4, 16% synthesize all three cytokines, and 9.6% synthesize IL-4 and gamma-IFN. These patterns of cytokine synthesis were found to be similar with both PMA + I and SEA/SEB stimulation and were observed in both peripheral blood memory/effector CD4+ T cells and in T cells of similar phenotype obtained from cutaneous delayed-type hypersensitivity sites. Taken together, these data strongly support the in vivo existence of human memory/effector T- cell subsets with “preprogrammed” cytokine synthesis potential, although they suggest that these subsets may be more complex than originally proposed in the TH1/TH2 hypothesis.

Despite the extensive use of nanoparticles (NPs) in various fields, adequate knowledge of human health risk and potential toxicity is still lacking. The human lymphocytes play a major role in the immune system, and it can alter the antioxidant level when exposed to NPs. Identification of the hazardous NPs was done using in vitro toxicity tests and this study mainly focuses on the comparative in vitro cytotoxicity and genotoxicity of four different NPs including cobalt (II, III) oxide (Co3O4), iron (III) oxide (Fe2O3), silicon dioxide (SiO2), and aluminum oxide (Al2O3) on human lymphocytes. The Co3O4 NPs showed decrease in cellular viability and increase in cell membrane damage followed by Fe2O3, SiO2, and Al2O3 NPs in a dose-dependent manner after 24 h of exposure to human lymphocytes. The oxidative stress was evidenced in human lymphocytes by the induction of reactive oxygen species, lipid peroxidation, and depletion of catalase, reduced glutathione, and superoxide dismutase. The Al2O3 NPs showed the least DNA damage when compared with all the other NPs. Chromosomal aberration was observed at 100 µg/ml when exposed to Co3O4 NPs and Fe2O3 NPs. The alteration in the level of antioxidant caused DNA damage and chromosomal aberration in human lymphocytes.

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The process of development of reliable and eco-friendly metallic nanoparticles is an important step in the field of nanotechnology. To achieve this, use of natural sources like biological systems becomes essential. In the present work, extracellular biosynthesis of gold nanoparticles using Padina gymnospora has been attempted and achieved rapid formation of gold nanoparticles in a short duration. The UV-vis spectrum of the aqueous medium containing gold ion showed peak at 527 nm corresponding to the plasmon absorbance of gold nanoparticles. Scanning electron microscopy showed the formation of welldispersed gold nanoparticles. FTIR spectra of brown alga confirmed that hydroxyl groups present in the algal polysaccharides were involved in the gold bioreduction. AFM analysis showed the results of particle sizes (53-67 nm) and average height of the particle roughness (60.0 nm). X-ray diffraction (XRD) spectrum of the gold nanoparticles exhibited Bragg reflections corresponding to gold nanoparticles. This environment-friendly method of biological gold nanoparticle synthesis can be applied potentially in various products that directly come in contact with the human body, such as cosmetics, and foods and consumer goods, besides medical applications.

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Attention deficit hyperactivity disorder (ADHD) is a highly disabling, early onset childhood neurobehavioral disorder with a higher occurrence in boys as compared to girls. Pharmacological and molecular genetic studies have revealed the influence of dopaminergic and serotonergic systems in the etiology of the disorder. Monoamine oxidase A (MAOA) is a mitochondrial enzyme that regulates the dopaminergic signals in the pre-synaptic region. Polymorphism in the promoter region of the MAOA gene, which comprises of 30 bp repeats with repeat number varying between 2.5, 3.5, 4.5, and 5.5, has been shown to be associated with various neurobehavioral disorders including ADHD. This is the first study on Indian ADHD cases to validate an association between transmission of MAOA promoter polymorphism and risk of ADHD. We have analyzed the MAOA promoter polymorphism in a group of ADHD probands, their parents and ethnically matched controls by UNPHASED. Our findings indicate significant difference in the frequency of 3.5 repeat allele (P = 0.02) between cases and controls and preferential transmission of the short allele (3.5 repeat) from mothers to male ADHD probands (P = 0.005). We conclude that the short 3.5 repeat allele of the MAOA-u VNTR is probably associated with ADHD in our population and could be the reason for making boys prone to ADHD as compared to girls.

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Attention deficit hyperactivity disorder (ADHD) is a childhood onset neurobehavioral disorder. Several studies worldwide have implicated a possible association between ADHD and transmission of different polymorphisms of the dopamine D4 receptor gene (DRD4) in different ethnic groups. However, this is the first report on the transmission of different polymorphisms of DRD4 in Indian subjects. Association of 5' flanking 120-bp duplication, exon 1 12-bp duplication, and exon 3 48-bp variable numbers of tandem repeats (VNTR) were analyzed in 50 ADHD cases. Haplotype-based haplotype relative risk (HHRR) analysis and transmission disequilibrium test (TDT) were carried out to ascertain the association of these polymorphisms with the disorder. Linkage disequilibria (LD) between the polymorphisms were calculated using EH+ and 2LD programs. Our preliminary data showed lack of association between ADHD and transmission of the 5' flanking 120-bp duplication and exon 1 12-bp duplication. But, the transmissions of 6 and 7 repeat alleles of exon 3 48-bp VNTR showed significant association with ADHD. We have also examined the haplotype frequencies and biased transmission of one haplotype was observed in ADHD probands. LD analysis showed very strong disequilibrium between exon 1 12-bp duplication and exon 3 48-bp VNTR. Strong LD was also observed between the 5' flanking 120-bp duplication and exon 1 12-bp duplication. The observed association between higher repeat alleles of exon 3 48-bp VNTR and Indian ADHD children is consistent with some of the earlier reports.