Comparative Genetic Structure of Cannabis sativa Including Federally Produced, Wild Collected, and Cultivated Samples

Currently in the United States, the sole licensed facility to cultivate Cannabis sativa L. for research purposes is the University of Mississippi, which is funded by the National Institute on Drug Abuse (NIDA). Studies researching Cannabis flower consumption rely on NIDA-supplied "research grade marijuana." Previous research found that cannabinoid levels of NIDA-supplied Cannabis do not align with commercially available Cannabis. We sought to investigate the genetic identity of Cannabis supplied by NIDA relative to common categories within the species. This is the first genetic study to include "research grade marijuana" from NIDA. Samples (49) were assigned as Wild Hemp (feral; 6) and Cultivated Hemp (3), NIDA (2), CBD drug type (3), and high THC drug type subdivided into Sativa (11), Hybrid (14), and Indica (10). Ten microsatellites targeting neutral non-coding regions were used. Clustering and genetic distance analyses support a division between hemp and drug-type Cannabis. All hemp samples clustered genetically, but no clear distinction of Sativa, Hybrid, and Indica subcategories within retail marijuana samples was found. Interestingly, the two analyzed "research grade marijuana" samples obtained from NIDA were genetically distinct from most drug-type Cannabis available from retail dispensaries. Although the sample size was small, "research grade marijuana" provided for research is genetically distinct from most retail drug-type Cannabis that patients and patrons are consuming.

Influence of omega-3 fatty acids on bovine luteal cell plasma membrane dynamics

Fish oil is a rich source of omega-3 fatty acids which disrupt lipid microdomain structure and affect mobility of the prostaglandin F_2α (FP) receptor in bovine luteal cells. The objectives of this study were to determine the effects of individual omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on 1) membrane fatty acid composition, 2) lipid microdomain structure, and 3) lateral mobility of the FP receptor in bovine luteal cells. Ovaries were collected from a local abattoir (n=5/experiment). The corpus luteum was resected and enzymatically digested using collagenase to generate a mixed luteal cell population. In all experiments, luteal cells were treated with 0, 1, 10 or 100μM EPA or DHA for 72h to allow incorporation of fatty acids into membrane lipids. Results from experiment 1 show that culturing luteal cells in the presence of EPA or DHA increased these luteal fatty acids. In experiment 2, both EPA and DHA increased spatial distribution of lipid microdomains in a dose-dependent manner. Single particle tracking results from experiment 3 show that increasing both EPA and DHA concentrations increased micro- and macro-diffusion coefficients, increased domain size, and decreased residence time of FP receptors. Collectively, results from this study demonstrate similar effects of EPA and DHA on lipid microdomain structure and lateral mobility of FP receptors in cultured bovine luteal cells. Moreover, only 10μM of either fatty acid was needed to mimic the effects of fish oil.

Effect of fish oil on lateral mobility of prostaglandin F2α (FP) receptors and spatial distribution of lipid microdomains in bovine luteal cell plasma membrane in vitro

Lipid microdomains are ordered regions on the plasma membrane of cells, rich in cholesterol and sphingolipids, ranging in size from 10 to 200 nm in diameter. These lipid-ordered domains may serve as platforms to facilitate colocalization of intracellular signaling proteins during agonist-induced signal transduction. It is hypothesized that fish oil will disrupt the lipid microdomains, increasing spatial distribution of these lipid-ordered domains and lateral mobility of the prostaglandin (PG) F_2α (FP) receptors in bovine luteal cells. The objectives of this study were to examine the effects of fish oil on (1) the spatial distribution of lipid microdomains, (2) lateral mobility of FP receptors, and (3) lateral mobility of FP receptors in the presence of PGF_2α on the plasma membrane of bovine luteal cells in vitro. Bovine ovaries were obtained from a local abattoir and corpora lutea were digested using collagenase. In experiment 1, lipid microdomains were labeled using cholera toxin subunit B Alexa Fluor 555. Domains were detected as distinct patches on the plasma membrane of mixed luteal cells. Fish oil treatment decreased fluorescent intensity in a dose-dependent manner (P < 0.01). In experiment 2, single particle tracking was used to examine the effects of fish oil treatment on lateral mobility of FP receptors. Fish oil treatment increased microdiffusion and macrodiffusion coefficients of FP receptors as compared to control cells (P < 0.05). In addition, compartment diameters of domains were larger, and residence times were reduced for receptors in fish oil-treated cells (P < 0.05). In experiment 3, single particle tracking was used to determine the effects of PGF_2α on lateral mobility of FP receptors and influence of fish oil treatment. Lateral mobility of receptors was decreased within 5 min following the addition of ligand for control cells (P < 0.05). However, lateral mobility of receptors was unaffected by addition of ligand for fish oil-treated cells (P > 0.10). The data presented provide strong evidence that fish oil causes a disruption in lipid microdomains and affects lateral mobility of FP receptors in the absence and presence of PGF_2α.

Development and analysis of an instrument to assess student understanding of GOB chemistry knowledge relevant to clinical nursing practice

The General, Organic, and Biological Chemistry Knowledge Assessment (GOB-CKA) is a multiple-choice instrument designed to assess students' understanding of the chemistry topics deemed important to clinical nursing practice. This manuscript describes the development process of the individual items along with a psychometric evaluation of the final version of the items and instrument. In developing items for the GOB-CKA, essential topics were identified through a series of expert interviews (with practicing nurses, nurse educators, and GOB chemistry instructors) and confirmed through a national survey. Individual items were tested in qualitative studies with students from the target population for clarity and wording. Data from pilot and beta studies were used to evaluate each item and narrow the total item count to 45. A psychometric analysis performed on data from the 45-item final version was used to provide evidence of validity and reliability. The final version of the instrument has a Cronbach's alpha value of 0.76. Feedback from an expert panel provided evidence of face and content validity. Convergent validity was estimated by comparing the results from the GOB-CKA with the General-Organic-Biochemistry Exam (Form 2007) of the American Chemical Society. Instructors who wish to use the GOB-CKA for teaching and research may contact the corresponding author for a copy of the instrument.

Training Enhances Vascular Relaxation after Chemotherapy-Induced Vasoconstriction

PURPOSE

Although evidence is accumulating that suggests regular moderate physical activity improves physiological and psychological well-being of cancer patients undergoing chemotherapy, the mechanisms involved remain unclear. Therefore, the purpose of this study was to determine if exercise training improves endothelium-dependent vasodilation after exposure to the chemotherapeutic agent 5-fluorouracil (5-FU).

METHODS

Rats were injected with N-methyl-N-nitrosourea (MNU) and assigned to either exercise (EX; treadmill running, 20-25 m.min(-1) grade, 30 min.d(-1), 5 d.wk(-1) for 8 wk) or sedentary (SED) groups. After the exercise training period, aortic rings were obtained and used to assess contractile and relaxation characteristics. In addition, endothelial nitric oxide synthase (eNOS) protein content and eNOS enzyme activity was determined.

RESULTS

Exercise training resulted in increased maximal endothelium-dependent vasorelaxation to acetylcholine (ACh, 1 x 10(-5) M) (SED, 56 +/- 3%; exercise, 71 +/- 5%; P < 0.05) after norepinephrine-induced (1 x 10(-7) M) vasoconstriction. Exposure of aortic rings from each group to increasing concentrations of 5-FU (7 x 10(-5) x 10 M(-3)) resulted in vasoconstriction. Rings obtained from exercise-trained animals demonstrated enhanced vasorelaxation to ACh (1 x 10(-5) M) after 5-FU-induced vasoconstriction compared with rings obtained from SED animals (P < 0.05). In addition, exercise training enhanced eNOS protein content and eNOS activity.

CONCLUSION

Exercise training enhances endothelium-dependent vasorelaxation after 5-FU-induced vasoconstriction, and this may be due, at least in part, to an increase in aortic eNOS protein content and activity. Such exercise-induced adaptations may help alleviate chemotherapy-related fatigue observed in cancer patients.

Differences in conformational dynamics of ribonucleases A and S as observed by infrared spectroscopy and hydrogen-deuterium exchange

Differences in conformational dynamics of bovine pancreatic RNase A and RNase S have been investigated using hydrogen-deuterium (H-D) exchange in conjunction with Fourier transform infrared spectroscopy. Deuteration-induced spectral changes in the amide I and II regions were monitored as a function of time. Second-derivative analysis revealed similar amide I spectral patterns for both proteins in H2O as well as fully deuterated in D2O. However, the rate of amide proton exchange of RNase S is much faster than that of RNase A at 25 degrees C as determined by changes in the intensity ratio of amide II/amide I bands and frequency red-shifts of amide I components. The frequency red-shifts of the amide I components ascribed to beta-sheet, alpha-helix, and beta-turns are continuous as a function of time, indicating that both proteins are too small to contain isolated secondary structural groups containing only exchanged or unexchanged amide protons in the partially deuterated intermediate states. Despite the dramatic difference in H-D exchange rate, the patterns of spectral changes in the conformation-sensitive amide I regions of RNase A and RNase S are very similar throughout the course of deuteration, indicating a similar pathway of amide proton exchange in both proteins.

Metabolism of 6-thiopurines. I. Irreversible binding of a metabolite of 6-thiopurine to mammalian hepatic protein in vitro

Irreversible binding of a metabolite of 6-thiopurine to mammalian hepatic protein was demonstrated in vitro. Protein binding occurred with rat, hamster, rabbit, pig and human liver microsomes in the presence of NADPH and oxygen. The involvement of the cytochrome P-450 system in the activation of 6-thiopurine to the chemically reactive metabolite was supported by the effects of inhibitors of cytochrome P-450 mediated reactions and phenobarbital induction. The binding of the metabolite appeared to be through formation of a mixed disulfide between 6-thiopurine and protein thiols. In the presence of thiols such as glutathione, the irreversible protein binding of 6-thiopurine was inhibited. No significant binding of 6-thiopurine to other tissues was observed in vitro with rats.

Metabolism of 6-thiopurines. II. Covalent binding of a 6-thiopurine metabolite to mammalian tissue protein in vivo

After injection of 6-thio[8-14C]purine i.p. in rats or rabbits radioactivity was shown to be irreversibly bound to protein of all tissues examined except brain. The binding increased with time after a single injection and increased nonlinearly in response to dose. Binding per milligram of protein was most extensive in intestine, spleen and liver. Binding in liver was primarily to microsomal protein with no binding detected in microsomal nucleic acid. Hepatic microsomal protein binding increased in rats fed a protein-free diet to deplete the hepato-cellular glutathione concentration. Binding to hepatic microsomal protein was decreased by pretreatment with phenobarbital or piperonyl butoxide, but not significantly with allopurinol. 6-Thiopurine at therapeutic doses had no apparent negative effects on either hepatocellular glutathione levels or hepatic microsomal aminopyrine N-demethylase activity during this time period. These observations may be significant regarding reported toxic side effects associated with 6-thiopurine.

Cytochrome P-450 dependent irreversible binding of 6-thiopurine to rat liver microsomal protein in vitro and protection by glutathione

6-Thiopurine when incubated in the presence of rat liver microsomes and reduced nicotine adenine dinucleotide phosphate (NADPH) binds to microsomal protein. Data support a mechanism involving initial metabolic activation via a cytochrome P450 mediated reaction to an intermediate which binds to protein. Glutathione protects against protein binding of the 6-thiopurine metabolite.