It takes T to tango

Of three recently cloned T-type voltage-gated calcium channels, alpha(1g) is most likely responsible for burst firing in thalamic relay cells. These neurons burst during various thalamocortical oscillations including absence seizures. In this issue of Neuron, Kim et al. inactivated alpha(1g), and resultant mice were deficient in relay cell bursting and resistant to GABA(B) receptor-dependent absence seizures, suggesting roles for alpha(1g) and relay cell bursting in absences.     

Arabidopsis ICX1 is a negative regulator of several pathways regulating flavonoid biosynthesis genes

Flavonoid biosynthesis gene expression is controlled by a range of endogenous and environmental signals. The Arabidopsis icx1 (increased chalcone synthase expression 1) mutant has elevated induction of CHS (CHALCONE SYNTHASE) and other flavonoid biosynthesis genes in response to several stimuli. We show that ICX1 is a negative regulator of the cryptochrome 1, phytochrome A, ultraviolet (UV)-B, low temperature, sucrose, and cytokinin induction of CHS expression and/or anthocyanin accumulation, demonstrating that these pathways are regulated either directly or indirectly by at least one common component. Expression analysis of CHS and other genes (LTP, CAB, and rbcS) indicates that ICX1 functions in both seedlings and mature leaf tissue and acts principally in the epidermis, consistent with the alterations in epidermal development seen in icx1. The mutant was unaltered in the synergistic interactions between UV-B, blue, and UV-A light that regulate CHS and we propose a model of action of ICX1 in these responses.     

Effects of overexpression of copper-zinc and manganese superoxide dismutases,catalase, and thioredoxin reductase genes on longevity in Drosophila melanogaster

The overexpression of antioxidative enzymes such as CuZn-superoxide dismutase (SOD), Mn-SOD, and catalase has previously been reported to extend life span in transgenic flies (Drosophila melanogaster). The purpose of this study was to determine whether life-extending effects persist if the recipient control strains of flies are relatively long-lived. Accordingly, the life spans of large numbers of replicate control and overexpressor lines were determined in two long-lived genetic backgrounds involving a combined total of >90,000 flies. Significant increases in the activities of both CuZn-SOD and catalase had no beneficial effect on survivorship in relatively long-lived y w mutant flies and were associated with slightly decreased life spans in wild type flies of the Oregon-R strain. The introduction of additional transgenes encoding Mn-SOD or thioredoxin reductase in the same genetic background also failed to cause life span extension. In conjunction with data from earlier studies, the results show that increasing the activities of these major antioxidative enzymes above wild type levels does not decrease the rate of aging in long-lived strains of Drosophila, although there may be some effect in relatively short-lived strains.     

Cloning of ZNF237, a novel member of the MYM gene family that maps to human chromosome 13q11-->q12

We have cloned a novel, widely expressed human gene, ZNF237, that shows extensive similarity to the N-terminal region of ZNF198. Two alternatively spliced regions were identified by RT-PCR; the major splice variant is predicted to encode a 383 amino acid protein that contains a single diverged MYM domain. ZNF237 maps to 13q11-->q12, immediately proximal to ZNF198.     

Effects of aging and hyperoxia on oxidative damage to cytochrome c in the housefly, Musca domestica

Cytochrome c is a component of the mitochondrial electron transport chain, where it transfers electrons from ubiquinol-cytochrome c reductase to cytochrome c oxidase. Autoxidation of some of the components of the electron transport chain is the main source of intracellular O(2)(-*)/H(2)O(2) production in aerobic organisms. Because cytochrome c is located on the outer surface of the inner mitochondrial membrane, it is likely to be constantly exposed to H(2)O(2), secreted by mitochondria into the cytosol. The specific objective of this study was to determine whether cytochrome c in the flight muscle mitochondria of the housefly is oxidatively damaged during aging and/or under severe oxidative stress induced by exposure of flies to 100% oxygen. Results of two independent methods, namely tritiated borohydride labeling for determining carbonylation and mass spectral analysis for the measurement of molecular mass, indicated that neither the carbonyl level nor the molecular mass of cytochrome c was affected by aging or hyperoxia. Thus, either cytochrome c is resistant to oxidative damage in vivo or the oxidized cytochrome c is promptly degraded. These findings also support the concept that protein oxidative damage during aging and under oxidative stress is selective.     

Prevention of flight activity prolongs the life span of the housefly, Musca domestica, and attenuates the age-associated oxidative damamge to specific mitochondrial proteins

The purpose of this study was to explore the mechanisms by which oxidative stress affects the aging process. The hypothesis that the rate of accumulation of oxidative damage to specific mitochondrial proteins is linked to the life expectancy of animals was tested in the housefly. The rate of oxygen consumption and life expectancy of the flies were experimentally altered by confining the flies in small jars, where they were unable to fly. Prevention of flight activity decreased the rate of oxygen utilization of flies and almost tripled their life span as compared to those permitted to fly. Rate of mitochondrial H(2)O(2) generation at various ages was lower in the low activity flies than in the high activity flies. Oxidative damage to mitochondrial proteins, adenine nucelotide translocase, and aconitase, detected as carbonyl modifications, was attenuated; and the loss in their functional activity occurring with age was retarded in the long-lived low activity flies as compared to the short-lived high activity flies. The two proteins were previously identified to be the only mitochondrial proteins exhibiting age-related increases in carbonylation. Results support the hypothesis that accrual of oxidative damage to specific protein targets and the consequent loss of their function may constitute a mechanism by which oxidative stress controls the aging process.     

Non-chemical method of DNA recovery and characterization of Mycobacterium avium subspecies paratuberculosis using IS 900 PCR

In the present study, two methods of DNA isolation-routine, traditional and standard DNA isolation protocol for Mycobacteria (Method 1) and a new non-chemicals and non-enzymes (physical) method (Method 2) of DNA recovery have been compared and evaluated in IS900 PCR for the specific detection of pathogen. Using the new Method 2, DNA has been recovered from few (1 - 3 colonies), extremely minute and stunted colonies. DNA, thus, isolated from these colonies (colonies PCR) and cultured for the first time from the cases of Crohn's disease in human beings, dairy cattle, raw milk and pasteurized commercial milk samples has been characterized in the present study. It is the first report from India.     

Mycobacterium avium subspecies paratuberculosis diagnosis and strain typing--present status and future developments

Mycobacterium avium subspecies paratuberculosis (MAP) is the etiological agent of paratuberculosis, a chronic gastroenteritis of ruminants and has zoonotic importance. We present here a review of MAP with respect to--(i) present diagnostic techniques and important developments; and (ii) MAP strain-typing tools. A summary of the findings to date is presented, and advantages and disadvantages of each of the methods are compared and discussed.     

Restoration of immunity in lymphopenic individuals with cancer by vaccination and adoptive T-cell transfer

Immunodeficiency is a barrier to successful vaccination in individuals with cancer and chronic infection. We performed a randomized phase 1/2 study in lymphopenic individuals after high-dose chemotherapy and autologous hematopoietic stem cell transplantation for myeloma. Combination immunotherapy consisting of a single early post-transplant infusion of in vivo vaccine-primed and ex vivo costimulated autologous T cells followed by post-transplant booster immunizations improved the severe immunodeficiency associated with high-dose chemotherapy and led to the induction of clinically relevant immunity in adults within a month after transplantation. Immune assays showed accelerated restoration of CD4 T-cell numbers and function. Early T-cell infusions also resulted in significantly improved T-cell proliferation in response to antigens that were not contained in the vaccine, as assessed by responses to staphylococcal enterotoxin B and cytomegalovirus antigens (P < 0.05). In the setting of lymphopenia, combined vaccine therapy and adoptive T-cell transfer fosters the development of enhanced memory T-cell responses.