Neo-clerodane diterpenoids from teucrium yemense

The aerial parts of Teucrium yemense yielded four new neo-clerodane diterpenoids, namely, 6β-O-acetyl-3β-hydroxyteucroxylepin, teucryemin, 19-O-acetylteucryemin and teucryeminone, in addition to the known flavone cirsiliol. The structures of the new compounds were elucidated from their spectral data, by chemical derivatization and by comparison with closely related compounds.     

A Comprehensive Approach to Identify Reliable Reference Gene Candidates to Investigate the Link between Alcoholism and Endocrinology in Sprague-Dawley Rats

Gender and hormonal differences are often correlated with alcohol dependence and related complications like addiction and breast cancer. Estrogen (E2) is an important sex hormone because it serves as a key protein involved in organism level signaling pathways. Alcoholism has been reported to affect estrogen receptor signaling; however, identifying the players involved in such multi-faceted syndrome is complex and requires an interdisciplinary approach. In many situations, preliminary investigations included a straight forward, yet informative biotechniques such as gene expression analyses using quantitative real time PCR (qRT-PCR). The validity of qRT-PCR-based conclusions is affected by the choice of reliable internal controls. With this in mind, we compiled a list of 15 commonly used housekeeping genes (HKGs) as potential reference gene candidates in rat biological models. A comprehensive comparison among 5 statistical approaches (geNorm, dCt method, NormFinder, BestKeeper, and RefFinder) was performed to identify the minimal number as well the most stable reference genes required for reliable normalization in experimental rat groups that comprised sham operated (SO), ovariectomized rats in the absence (OVX) or presence of E2 (OVXE2). These rat groups were subdivided into subgroups that received alcohol in liquid diet or isocalroic control liquid diet for 12 weeks. Our results showed that U87, 5S rRNA, GAPDH, and U5a were the most reliable gene candidates for reference genes in heart and brain tissue. However, different gene stability ranking was specific for each tissue input combination. The present preliminary findings highlight the variability in reference gene rankings across different experimental conditions and analytic methods and constitute a fundamental step for gene expression assays.     

Phytoplankton associations in two pools and their relationships with associated benthic flora

Summary The theory underlying the delineation of phytoplankton association is examined, and the associations of Abbot's pond and Priddy pool are characterised according to the conclusions derived from this examination. The importance of extended investigations is stressed. Abbot's pond has a eu-planktonic flora with abundant Asterionella formosa, Pandorina morum and Chrysococcus diaphanus. The euphytoplankton of Priddy pool consists of a very few species, of which Dinobryon sertularia is most abundant, but owing to the action of wind on the pool, many species are introduced into the open water by disturbance of benthic habitats.     

Extraction and identification of different prostaglandins in Allium cepa

Green onions (Allium cepa) were homogenized in a blender and extracted by normal extraction methods except that diethyl ether was used as the first extracting solvent. Different analytical procedures were used for the identification of the prostaglandins separated. TLC was applied using silica gel 60 F254 plates and a mixture of benzene, dioxane and acetic acid (20:10:1) as eluent, and the Rf values were compared with those of authentic samples. GC analysis on an SE 30 packed column and FID was applied; relative retention times of the onion extract components were measured and matched with authentic prostaglandin samples using cholesterol as an internal standard. GC-MS analyses using the same conditions adopted for GC analysis were conducted on a Finnigan MAT 112S instrument. Four peaks were identified. The prostaglandins identified were F1 alpha, E1, B1 and A2.     

The effects of dietary L-ascorbic acid on the absorption and utilization of Na75SeO3 of silver-treated rats

Male hooded lister rats of the Rowett Institute strain, treated with silver in the drinking water, were used to study the effects of L-ascorbic acid on the utilization of Na75SeO3. Silver treatment dramatically decreased the absorption of 75Se from the rat GI tract. An attempt was made to utilize the reducing ability of L-ascorbic acid upon the absorption of 75Se from the rat GI tract. Increasing concentrations of L-ascorbic acid slightly increased the amount of 75Se absorbed from the rat gut.     

Isolation of bacteriophages from commercial sera

Summary Commercially available sera contain bacterial viruses. The possible origin of serum bacteriophages and the implication of this observation for tissue culture studies are discussed. Research supported by a Postdoctoral Fellowship (1 FO2 HD 50,527-1) from the National Institute of Child Health and Human Development.     

Mutational hotspots in the mitochondrial D-loop region of cancerous and precancerous colorectal lesions in Egyptian patients

Mutations in the mitochondrial genome (mtDNA) are associated with different types of cancer, specifically colorectal cancer (CRC). However, few studies have been performed on precancerous lesions, such as ulcerative colitis (UC) lesions and adenomatous polyps (AP). The aim of this study was to identify mtDNA mutations in the cancerous and precancerous lesions of Egyptian patients. An analysis of the mutations found in six regions of the mtDNA genome (ND1, ND5, COI, tRNAser, D-loop 1, and 2) in 80 Egyptian patients (40 CRC, 20 UC, and 20 AP) was performed using polymerase chain reaction-single-strand conformational polymorphism techniques and followed up by direct sequencing. The overall incidence of mutations was 25%, 25%, and 35% in CRC, UC, and AP cases, respectively. Although there was no common mutation pattern within each group, a large number of mutations were detected in the D-loop region in all of the groups. Some mutations (e.g., T414G) were detected repeatedly in precancerous (UC and AP) and cancerous lesions. Mutations detected in patients with CRC were predominantly found in the ND1 gene (40%). Our preliminary study suggests that Egyptian patients with CRC have a large number of mtDNA mutations, especially in the D-loop region, which have not been previously reported. Mutations in the mtDNA of precancerous lesions (i.e., AP and UC) may contribute to transformation events that lead to CRC.