PET imaging a MPTP-induced mouse model of Parkinson's disease using the fluoropropyl-dihydrotetrabenazine analog [18F]-DTBZ (AV-133)

Parkinson's disease (PD) is characterized by the loss of dopamine-producing neurons in the nigrostriatal system. Numerous researchers in the past have attempted to track the progression of dopaminergic depletion in PD. We applied a quantitative non-invasive PET imaging technique to follow this degeneration process in an MPTP-induced mouse model of PD. The VMAT2 ligand (18)F-DTBZ (AV-133) was used as a radioactive tracer in our imaging experiments to monitor the changes of the dopaminergic system. Intraperitoneal administrations of MPTP (a neurotoxin) were delivered to mice at regular intervals to induce lesions consistent with PD. Our results indicate a significant decline in the levels of striatal dopamine and its metabolites (DOPAC and HVA) following MPTP treatment as determined by HPLC method. Images obtained by positron emission tomography revealed uptake of (18)F-DTBZ analog in the mouse striatum. However, reduction in radioligand binding was evident in the striatum of MPTP lesioned animals as compared with the control group. Immunohistochemical analysis further confirmed PET imaging results and indicated the progressive loss of dopaminergic neurons in treated animals compared with the control counterparts. In conclusion, our findings suggest that MPTP induced PD in mouse model is appropriate to follow the degeneration of dopaminergic system and that (18)F-DTBZ analog is a potentially sensitive radiotracer that can used to diagnose changes associated with PD by PET imaging modality.     

Comparative treatability of Moso bamboo and southern pine with CCA preservative using a commercial schedule

The United States Department of Agriculture introduced several bamboo species into the southern United States in the 1920s. One of the species included was Moso bamboo (Phyllostachys pubescens), a species native to China. This species grows well in South Carolina. In rural areas, bamboo splits are frequently used for fences and stakes for supporting crop plants. However, the decay resistance of bamboo is very low. In this study, Moso bamboo splits and southern pine lumber were treated in a commercial wood-treating plant using a full-cell process with Chromated Copper Arsenate (CCA) preservative to target retentions of 4.0 and 6.4kg/m3. Results indicate that bamboo is much more difficult to treat than southern pine. Using the same treatment procedures for southern pine, bamboo could only achieve approximately 22% of the target CCA retention.     

Germ Tube Growth Inhibitor from Cronartium comandrae Aeciospores

The reduction of nucleic acid by an endogenous polynucleotide phosphorylase and ribonuclease in cells of Brevibacterium JM98A (ATCC 29895) was studied. A simple process was developed for the activation of the endogenous RNA-degrading enzyme(s). RNA degradation was activated by the presence of Pi with 14.2 mumol of ribonucleoside 5'-monophosphate per g of cell mass accumulating extracellularly. The optimum pH for degradation of RNA was 10.5 and the optimum temperature was 55 to 60 degrees C. Enzymatic activity was inhibited by the presence of Ca2+, Zn2+, or Mg2+. Although some of the RNA-degrading enzymatic activity was associated with the ribosomal fraction, most was soluble. Both polynucleotide phosphorylase and ribonuclease activities were identified.     

Double-stranded RNA in isolates ofDiscula destructiva from the Eastern United States

Phenol-chloroform extraction and CF-11 chromatography were used to examine 83 isolates ofDiscula sp. for the presence of dsRNA. Agarose-gel electrophoresis revealed three major size classes: large (ca. 8–12 kbp), medium (ca. 3–4 kpb), and small (ca. 1.5–2.5 kbp). Additional segments were present in two isolates. Double-stranded RNA was demonstrated in 80/80 isolates ofDiscula destructiva, but not in three isolates of an unidentifiedDiscula sp. commonly referred to asDiscula, Type 2. Twenty-two isolates contained one or more large segments. Isolates with large segments were more common in collection sites on the eastern slope of the Appalachian Mountains. The most common banding profile consisted of two medium and two small bands.     

Optimum tissue culture conditions for selection of resistance to Phytophtora cinnamomi in pine callus tissue

The present experimentation compared the best nutrient medium, temperature, and growth hormones for callus induction and growth of various pine species from different seed sources with their effect on growth of Phytophthora cinnamomi. Callus tissues maintained on a modified Murashige and Skoog medium with 10^–5M 2,4-D at 26°C in the dark optimized the expression of differential resistance when inoculated with hyphae of P. cinnamomi. High concentration of 2,4-D (5×10^–5M) inhibited growth of P. cinnamomi.Abbreviations AL loblolly pine-Alabama - PL South Carolina - AS shortleaf pine-Alabama - CS Georgia - AV Virginia pine-Alabama     

Bacteria Associated with Butterfly Stain of Chilean Tepa

Butterfly stain, common in Chilean tepa (Laureliopsis philippiana[Looser] Schodde) trees, appears in cross-section of the stem as a series of partially overlapping orange-brown arcs that in early stages resembles a butterfly. Bacterial isolates from stained tepa wood samples cultured under aerobic and anaerobic conditions were identified using several commercially available identification systems. Pseudomonas sp. were most common in the cultures handled aerobically, and Clostridium sp. were found in the cultures handled anaerobically. A pectinolytic Bacillus sp. and a Gram-negative rod-shaped bacterium that emitted a strong naphthalene-like odor similar to that of stained wood were also isolated. Not all isolates could be identified. This is the first report of Clostridium from tepa. Received: 4 June 1999 / Accepted: 25 August 1999     

A COMPARISON OF CERTAIN ACTIONS OF DEMEROL AND METHADONE

Demerol and methadone have advantages over morphine. Demerol requires a higher dosage than methadone, but produces less respiratory depression. Therefore, it can be used more freely in cases where respiratory depression is contraindicated. Demerol does not depress the cough reflex, and methadone is preferred for this purpose. Both drugs have a sufficient tendency to produce addiction that the usual narcotic restrictions should be observed.     

Genetic relatedness among dsRNAs from different isolates ofDiscula destructiva

The genetic relationships among double-stranded RNAs (dsRNAs) from 76 isolates ofDiscula destructiva obtained from different geographic locations from New York to Alabama were studied by dot-blot hybridization. The dsRNA segments, identified by agarose gel electrophoresis, varied in size and number. Probes were constructed from total dsRNA from six isolates with different dsRNA profiles and of different geographic origins. Each probe hybridized with dsRNA from ca. 62% of the isolates under the high-stringency washing conditions used. No major differences in the percentage of the total isolates that hybridized with each probe were observed. These results suggest a recent common origin of these isolates ofD. destructiva.