Ascorbic acid and aging in the rat. Uptake of ascorbic acid by teeth and concentration of various forms of ascorbic acid in different organs

1. The uptake of ascorbic acid in vitro by the teeth of rats showed a gradual decrease with age, indicating that the uptake may be related to collagen synthesis as in bone. 2. The concentration of total free ascorbic acid in various organs declined with age, but the rate of decline was different in different organs. In the spleen, however, it increased until maturity and then declined. 3. This decrease may be due to one or both of the following reasons: (a) the permeability of different tissues may decrease at different rates for ascorbic acid, or (b) the requirement for ascorbic acid may decrease at different rates. 4. The bound ascorbic acid declined with age in the skin, kidney, liver and brain after the age of 10-12 weeks, and in the spleen after the age of 26 weeks. 5. The concentration of dehydroascorbic acid and dioxogulonic acid declined with age in the skin.     

SP500263, a novel SERM,blocks osteoclastogenesis in a human bone cell model: role of IL-6 and GM-CSF

Bone metabolism requires tightly coupled activities exhibited by two unique cell populations, the bone-resorbing osteoclasts and the bone-forming osteoblasts. Imbalance in the function of these two cell types can result in osteoporosis, a condition characterized by loss in bone integrity and of bone mass. We developed a human bone cell culture model that allows the in vitro study of bone formation and osteoclastogenesis and employed this bone model for the screening and pharmacological analyses of protein and small molecule therapeutics. The cytokines, interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF), play an intricate role in osteoclastogenesis in this system. Neutralizing antibodies to IL-6 and GM-CSF decreased the formation of osteoclast-like cells. SP500263, an early lead compound from a novel class of selective estrogen receptor modulators (SERMs), was more efficacious than estrogen and comparable to raloxifene in blocking cytokine production and formation of osteoclast-like cells. Our research demonstrates the usefulness of the in vitro co-culture model in the dissection of molecular events relevant to bone metabolism and provides greater insight into a potential novel role for cytokines in bone resorption. Furthermore, representatives of the SP500263 family of SERMs may be effective as therapeutics for the treatment of osteoporosis.     

Neurotensin and neurotensin receptor 1 mRNA expression in song‐control regions changes during development in male zebra finches

Learned vocalizations are important for communication in some vertebrate taxa. The neural circuitry for the learning and production of vocalizations is well known in songbirds, many of which learn songs initially during a critical period early in life. Dopamine is essential for motor learning, including song learning, and dopamine‐related measures change throughout development in song‐control regions such as HVC, the lateral magnocellular nucleus of the anterior nidopallium (LMAN), Area X, and the robust nucleus of the arcopallium (RA). In mammals, the neuropeptide neurotensin strongly interacts with dopamine signaling. This study investigated a potential role for the neurotensin system in song learning by examining how neurotensin (Nts) and neurotensin receptor 1 (Ntsr1) expression change throughout development. Nts and Ntsr1 mRNA expression was analyzed in song‐control regions of male zebra finches in four stages of the song learning process: pre‐subsong (25 days posthatch; dph), subsong (45 dph), plastic song (60 dph), and crystallized song (130 dph). Nts expression in LMAN during the subsong stage was lower compared to other time points. Ntsr1 expression was highest in HVC, Area X, and RA during the pre‐subsong stage. Opposite and complementary expression patterns for the two genes in song nuclei and across the whole brain suggest distinct roles for regions that produce and receive Nts. The expression changes at crucial time points for song development are similar to changes observed in dopamine studies and suggest Nts may be involved in the process of vocal learning. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 78: 671–686, 2018     

N-(Iodoacetyl)-N'-(anthraquinon-2-oyl)-ethylenediamine (IAED): a new heterobifunctional reagent for the preparation of biochips

Design and synthesis of a new heterobifunctional reagent, N-(iodoacetyl)-N'-(anthraquinon-2-oyl)-ethylenediamine (IAED), have been described for the preparation of oligonucleotide-based biochips. The performance of the featured reagent is probed by the immobilization of thiolated and thiophosphorylated oligonucleotides on modified glass microslides via two routes (routes A and B). The immobilization procedure was accelerated by performing a chemical reaction between thiolated oligomers and the iodoacetyl moiety of the reagent under microwaves (MW), where it is completed in just 10 min. The quality of the constructed oligonucleotide microarrays was tested by performing a hybridization assay with a complementary target and subsequently used for the detection of base mismatches. The immobilized probes were found to be thermally stable.     

Evidence for estradiol-induced differential expression of genes for brain RNA polymerase during developmental stages of the rat

In order to gain insight into the steroid hormone-induced differential expression of genes for several rate-limiting enzymes of various metabolic pathways during differentiation, growth, adulthood, and senescence in rats, nuclear RNA polymerase of the cerebellum and cerebral hemispheres were studied. The level of this enzyme in both the tissues was highest in the immature rats and decreased significantly thereafter with increasing age. Ovariectomy decreased, and estradiol administration increased significantly the activity of this enzyme in both cerebellum and cerebral hemispheres of immature, young-adult, adult, and late-adult rats but not of senescent rats. However, the effects of these treatments were highest in the young-adult rats.     

Thermostable pullulanase from a mesophilic Bacillus cereus isolate and its mutant UV7.4

Summary A mesophilicBacillus cereus strain was isolated from soil. Since it produced fairly good amounts of extracellular pullulanase, mutations with ultraviolet light and nitrosoguanidine were done to improve the productivity. One of the second generation mutants, UV7.4, produced larger amounts of pullulanase at 37°C than most (mesophilic or thermophilic) organisms reported. The pullulanase was highly active and stable for up to one hour at 70°C. If developed further, UV7.4 can be used commercially for the saccharification of starch.