Targeting age‐specific changes in CD4+ T cell metabolism ameliorates alloimmune responses and prolongs graft survival

Age impacts alloimmunity. Effects of aging on T‐cell metabolism and the potential to interfere with immunosuppressants have not been explored yet. Here, we dissected metabolic pathways of CD4⁺ and CD8⁺ T cells in aging and offer novel immunosuppressive targets. Upon activation, CD4⁺ T cells from old mice failed to exhibit adequate metabolic reprogramming resulting into compromised metabolic pathways, including oxidative phosphorylation (OXPHOS) and glycolysis. Comparable results were also observed in elderly human patients. Although glutaminolysis remained the dominant and age‐independent source of mitochondria for activated CD4⁺ T cells, old but not young CD4⁺ T cells relied heavily on glutaminolysis. Treating young and old murine and human CD4⁺ T cells with 6‐diazo‐5‐oxo‐l‐norleucine (DON), a glutaminolysis inhibitor resulted in significantly reduced IFN‐γ production and compromised proliferative capacities specifically of old CD4⁺ T cells. Of translational relevance, old and young mice that had been transplanted with fully mismatched skin grafts and treated with DON demonstrated dampened Th1‐ and Th17‐driven alloimmune responses. Moreover, DON diminished cytokine production and proliferation of old CD4⁺ T cells in vivo leading to a significantly prolonged allograft survival specifically in old recipients. Graft prolongation in young animals, in contrast, was only achieved when DON was applied in combination with an inhibition of glycolysis (2‐deoxy‐d‐glucose, 2‐DG) and OXPHOS (metformin), two alternative metabolic pathways. Notably, metabolic treatment had not been linked to toxicities. Remarkably, immunosuppressive capacities of DON were specific to CD4⁺ T cells as adoptively transferred young CD4⁺ T cells prevented immunosuppressive capacities of DON on allograft survival in old recipients. Depletion of CD8⁺ T cells did not alter transplant outcomes in either young or old recipients. Taken together, our data introduce an age‐specific metabolic reprogramming of CD4⁺ T cells. Targeting those pathways offers novel and age‐specific approaches for immunosuppression.     

Technical Study of a Standalone Photovoltaic–Wind Energy Based Hybrid Power Supply Systems for Island Electrification in Malaysia

Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions.     

Possible role of metal ionophore against zinc induced cognitive dysfunction in <Emphasis Type="SmallCaps">d-</Emphasis>galactose senescent mice

Metal ionophores are considered as potential anti-dementia agents, and some are currently undergoing clinical trials. Many metals are known to accumulate and distribute abnormally in the aging brain. Alterations in zinc metal homeostasis in the glutaminergic synapse could contribute to ageing and the pathophysiology of Alzheimer’s disease (AD). The present study was designed to investigate the effect of metal ionophores on long term administration of zinc in D-galactose induced senescent mice. The ageing model was established by combined administration of zinc and D-galactose to mice for 6 weeks. A novel metal ionophore, PBT-2 was given daily to zinc-induced d-galactose senescent mice. The cognitive behaviour of mice was monitored using the Morris Water Maze. The anti-oxidant status and amyloidogenic activity in the ageing mouse was measured by determining mito-oxidative parameters and deposition of amyloid β (Aβ) in the brain. Systemic administration of both zinc and D-galactose significantly produced memory deficits, mito-oxidative damage, heightened acetylcholinesterase enzymatic activity and deposition of amyloid-β. Treatment with PBT-2 significantly improved behavioural deficits, biochemical profiles, cellular damage, and curbed the deposition of APP in zinc-induced senescent mice. These findings suggest that PBT-2, acting as a metal protein attenuating compound, may be helpful in the prevention of AD or alleviation of ageing.     

Studies on Crocker sarcoma 180 under the effect of alkylating agents. IV. Morphological studies of sarcoma 180 during treatment with the antitumour drug cytoxan

The effect of one massive dose of cytoxan (150 mg/kg), as an alkylating agent, on the morphology of sarcoma 180 cells was followed after 1, 3, 6, 12, 24, 48, 96, 120, and 168 h. After 1 h the cells of treated tumour showed clumping and a decrease in their size. In addition, statistical analysis manifested significant decrease in all phases of mitotic figures. All mitotic figures were completely stopped after 3 h from cytoxan treatment. After 6 and 12 h from cytoxan treatment the hyaline degenerations became more marked in the treated tumour tissue. Chromosomal bridge formation, nuclei aberrations and polynuclear cells were more prominent in 24, 48, and 96 h from cytoxan treatment. Increase in the nuclear size and hyaline degeneration were observed in treated section of 120 and 168 h.     

Pregnenolone, dehydroepiandrosterone, and their sulfate and fatty acid esters in the rat brain

The rat brain contains large amounts of pregnenolone (P) and dehydroepiandrosterone (D) arising from local biosynthetic pathways. We have devised a procedure for the measurement of both "neurosteroids" either unconjugated or released from their sulfate (S) or fatty acid (L) esters. The measurements were performed at the acrophase of the circadian variation of neurosteroids, and confirmed the large accumulation of P (25 +/- 8 ng/g, mean +/- SD) and of PS (19 +/- 6 ng/g) and DS (2.1 +/- 0.5 ng/g) in the brain of adult male rats. We found that fatty acid esters constitute the major species of neurosteroids in brain (PL 46 +/- 14, and DL 36 +/- 7 ng/g, in adult males). The levels of P and DS were increased by daily injection of vehicle to intact males, whereas castration, without or with testosterone or estradiol supplementation (2 mg daily for 7 days), did not produce a significant change of neurosteroids concentrations. Measurements of neurosteroids had not been previously reported in cyclic females. The levels of P, PL, and DS were identical in proestrous females and in intact males, whereas PS (26 +/- 6 ng/g) and DL (50 +/- 16 ng/g) were increased in females. Compared to proestrous females, diestrous females had lower levels of PS (19 +/- 6 ng/g), DS (1.7 +/- 0.4 ng/g), and PL (43 +/- 19 ng/g). These differences suggested a modulatory role of ovarian secretions on the metabolism of neurosteroids.     

Influence of tea and coffee beverages on prostacyclin synthesis by the rat aorta

Influences of 2.5 and 5% (w/v) aqueous tea and coffee beverages administered ad lib. to rats for two weeks on PGI2 synthesis by the rat thoracic aorta in vitro were investigated using a rat platelet antiaggregatory bioassay and HPLC methods. The 2.5% beverages did not affect PGI2 synthesis; however, the 5% beverages significantly decreased PGI2 synthesis. The observed decreases were significantly abolished in presence of exogenous arachidonic acid suggesting a beverage-induced inhibition of precursor release. The ability of the beverages to inhibit PGI2 synthesis may partly contribute towards better understanding of the biochemical mechanisms underlying some of the beverages-induced actions in vivo.     

Bacterial siderophores : structure and NMR assignment of pyoverdins Pa,siderophores ofPseudomonas aeruginosa ATCC 15692

Summary In iron-deficient conditions,Pseudomonas aeruginosa ATCC 15692 synthesizes two major siderophores, pyoverdins Pa and pyoverdin Pa B. Two other compounds, pyoverdin Pa A (occurring from hydrolysis of pyoverdin Pa during the culture) and pyoverdin Pa C (occurring artifactually during the purification procedure) were also isolated. All these compounds possess the same partly cyclic peptide chain wherel-Orn(OH · HCO) isN -formyl,N -hydroxy-l-ornithine. The chain is bound to a chromophore derived from 2,3-diamino-6,7-dihydroxyquinoline and having the (S) configuration. The four pyoverdins differ only in the acyl substituent bound to the nitrogen atom bound to carbon C3 of the chromophore. This is succinamide (pyoverdin Pa), succinic acid (pyoverdin Pa A), methyl succinate (pyoverdin Pa C) and 2-oxoglutaric acid (pyoverdin Pa B). The complete¹H- and¹³CNMR assignments, using two-dimensional total correlation NMR spectroscopy (TOCSY) and rotating-frame Overhauser enhancement spectroscopy (ROESY) procedures, as well as¹H-¹³C correlations, are reported. The complete sequence of the peptide using CH-NH correlations was achieved by NMR and confirmed the partly cyclic structure earlier reported using fast-atom-bombardment mass spectrometry (FAB-MS) on the siderophores and their dansylated fragments [Briskot G, Taraz K, Budzikiewicz H (1989)Liebigs Ann Chem: 375–384]. The use of these NMR procedures appears to be a tool of choice and a complementary approach to FAB-MS in the structure determination of some complex pyoverdins.Abbreviations Ser serine - Arg arginine - Thr ethreonine - Lys lysine - OHOrn N -hydroxyornithine - Chr chromophore     

Meloidogyne mayaguensis n. sp. (Meloidogynidae), a Root-knot Nematode from Puerto Rico

Meloidogyne mayaguensis n. sp. is described and illustrated from specimens obtained from galled roots of eggplant, Solanum melongena L., from Puerto Rico. The perineal pattern of females is round to ovoid with fine, widely spaced striae. It has occasional breaks of striation laterally and a circular tail tip area lacking striae. The stylet, 15.8 μm long, has reniform knobs that merge gradually with the stylet shaft. Males have a high, rectangular, smooth head region, not set off from the body contour. The labial disc is continuous with the medial lips which do not slope posteriorly. The styler, 22.9 μm long, has large rounded backward sloping knobs; the shaft is of uneven diameter. Mean body length of second-stage juveniles is 453.6 μm. The truncate head region is not annulated, and the rounded, slightly raised labial disc and the crescentic medial lips form dumbbell-shaped lip structures. The stylet, 11.6 μm long, has rounded, posteriorly sloping knobs. The slender tail, 54.4 μm long, gradually tapers to a bluntly pointed tip. Tomato, tobacco, pepper, and watermelon are good hosts; cotton and peanut are not hosts. M. mayaguensis n. sp. reproduces by mitotic parthenogenesis and has a somatic chromosome number of 2n = 44-45. The enzyme patterns are unique among Meloidogyne species.     

A clonal derivative of mammary epithelial cell line COMMA-D retains stem cell characteristics of unique morphological and functional heterogeneity

The COMMA-D cell line derived from mammary epithelial cells of midpregnant mice was shown previously to be heterogeneous as determined by phase-contrast microscopy, immunocytochemical staining, DNA content, and oncogenic potential (K.D. Danielson et al. (1984) Proc. Natl. Acad. Sci. USA 81, 3756; D. Medina et al. (1986) J. Natl. Cancer Inst. 76, 1143). Clonal subpopulations of COMMA-D cells have now been isolated by both transfection and selection using a dominant-selectable gene transfer vector and by limiting dilution. Despite their clonal origin, these subpopulations in many cases retained the heterogeneity of the parental COMMA-D line. Of 18 clonal lines assayed, only 5 were able to express beta-casein mRNA. Pooled populations of G418-resistant cells expressed substantially higher levels of beta-casein mRNA than the clonal lines. One of the expressing clonal lines, BNW-7, was characterized further, using immunocytochemical techniques. Approximately 10% of BNW-7 cells expressed casein under the appropriate hormonal and cell-substratum conditions by indirect immunofluorescent staining. Casein immunoperoxidase staining of BNW-7 cells on floating collagen gels revealed that casein-producing cells were localized in small alveolar structures, which were formed in a non-hormone-dependent fashion. The cells in these alveolar structures were cuboidal with basally located nuclei, expressed keratin intermediate filament proteins preferentially, and comprised approximately 18% of the total cells. Cells elsewhere on the surface of the gel displayed a flattened morphology, and expressed vimentin intermediate filament proteins preferentially. A proportion of COMMA-D cells, therefore, appeared to have some of the characteristics of mammary stem cells, and retained the ability to differentiate and form phenotypically heterogeneous cell populations in vitro.