Investigations into the role of cGMP in mediating the effects of extracellular nucleotides on root hair growth in Arabidopsis thaliana

textThe eATP pathway begins a cascade of events which includes the involvement of nitric oxide synthase (NOS) and nitrate reductase (NR) in the production of nitric oxide (NO). Research has shown that SNAP (S-nitroso-N-acetylpenicillamine) and NONOates (diazeniumdiolates) promote the availability of NO and, with the addition of guanylate cyclase, form cyclic guanine monophosphate (cGMP), and root hair growth is promoted. Phosphodiesterases (PDE) break down the cGMP and agents such as IBMX and Viagra inhibit the PDEs thereby inhibiting root hair growth. Several questions remain to be answered. How much cGMP is necessary for the promotion of root hair growth? Is there an optimal concentration of cGMP which stimulates root hair growth, above which is inhibitory, or below which is ineffective? Is there a “non-hydrolyzable analog” of cGMP which is more effective at promoting root hair growth? Is it possible to see inhibition of root hair growth with exposure to a known inhibitor, such as ATPγS, and then reverse the inhibition with a “non-hydrolyzable analog” of cGMP? Answering these vi questions is the substance of this research and the answers will provide direction and understanding to the growth-promoting and regulatory role eATP plays in signal transduction pathways in plants. With the hypothesis asking whether the effects of NO on root hair growth is cGMP-dependent or cGMP-independent we found that there is no consistent concentration of non-hydrolyzable cGMP analog which promotes root hair growth. Additionally we found that the 8-Br-cGMP analog promotes root hair growth more consistently in Arabidopsis thaliana than its counterpart, dibutyryl cGMP. We substantiated previously published results showing an inhibition of root hair growth when root hairs were exposed to high concentrations of ATPγS. Based on these results we believe the promotion of root hair growth in Arabidopsis thaliana to be mediated independently of cGMP.Science and Mathematics Educatio

Economic Impact of Lyme Disease

Since 1975, Lyme disease has become the most common vectorborne inflammatory disease in the United States

DNA characterization of Lyme disease spirochetes.

Lyme disease spirochetes (LDS) have phenotypic characteristics of both treponemes and borreliae. To ascertain whether one or more species of LDS exist, as well as their taxonomic status, we determined the DNA base (G + C) content for three strains of LDS, the DNA relatedness of ten strains isolated in the United States or Europe, and the DNA relatedness of LDS to other spirochetes. The G + C content of the three LDS strains was 28.1-29.0 mol%, most similar to those of Borellia hermsii (30.6 mol %) and Treponema hyodysenteriae (25.6 mol %) among the other spirochetes tested. DNA hybridization studies of nine LDS strains to a reference strain isolated from human blood revealed divergence (unpaired bases) within related nucleotide sequences of only 0.0-1.0 percent, indicating the strains were one species. Similarly, relatedness values of seven strains to the reference strain were high: 58-98 percent (mean, 71 percent) in 50 degrees C reactions and 50-93 percent (mean, 69 percent) in 65 degrees C reactions. Labeled DNA from B. hermsii was 30-40 percent related to three Lyme disease spirochete strains in 50 degrees C reactions and 8-10 percent related in 65 degrees C reactions. In contrast, DNA from the reference LDS strain showed relatedness of only 1 percent to DNAs of two leptospires and only 16 percent to DNA from T. hyodysenteriae. We conclude that LDS are a single species, genetically unlike treponemes or leptospires, which belong in the genus Borrelia

Oedema of the metatarsal heads II-IV and forefoot pain as an unusual manifestation of Lyme disease: a case report

We report the case of a healthy 36 year old man who suffered from foot pain lasting for weeks, without having a specific medical history relating to it. The clinical evaluation was interpreted as a transfer metatarsalgia caused by a splayfoot. The radiographs revealed no pathology except the splayfoot deformity. Due to persistent pain and swelling of the entire forefoot, after two weeks of conventional treatment, magnet resonance images (MRI) and a blood sample were taken. The laboratory investigation showed raised levels of white blood cell count and C-reactive protein. The MRI showed up oedema in the metatarsal heads II-IV, as well as soft tissue swelling of the forefoot without any signs of decomposition

Identification of winter weather types of the eastern North Pacific by means of a partial zonal index

This thesis document was issued under the authority of another institution, not NPS. At the time it was written, a copy was added to the NPS Library collection for reasons not now known.  It has been included in the digital archive for its historical value to NPS.  Not believed to be a CIVINS (Civilian Institutions) title.In case of war, the weather information available to the U.S. Naval Service in the Pacific would probably be reduced to observations from continental North America and from a few island possessions. It is the purpose of this study to contribute to the problem of forecasing for this area under such conditions.http://www.archive.org/details/identificationof00bettU.S. Navy (U.S.N.) authors