PubMed · 15628510
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Takao Shimizu. 2004. [Acetate].. https://pubmed.ncbi.nlm.nih.gov/15628510/
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Catechin compounds from Korean green tea as potential sources of anticancer and antioxidant components were target materials in this work. The methodologies of solvent extraction and partition were utilized to recover catechin compounds from green tea. The optimum experimental condition was obtained by optimizing operating factors, such as, the extraction solvent, extraction time and operating temperature. After extracting the green tea with water at 80 degrees C for 40 min, the extract was partitioned with water/chloroform, which was best suited to remove caffeine impurity from the extract. Further, the resulting extract was partitioned water/ethyl acetate to deeply purify the catechin compounds of EGC, EC, EGCG and ECG. The experimental result in this work could be extended to preparative HPLC to obtain EGCG on commercial scale.
BACKGROUND: The current study was conducted to evaluate the efficacy of human papillomavirus (HPV) DNA testing of residual ThinPrep specimens, which were pretreated with acetic acid to optimize cellularity with a special focus on atypical squamous cells of undetermined significance (ASCUS) specimens. METHODS: A total of 120 ThinPrep gynecologic samples were chosen for a pilot study including cases with a normal or abnormal interpretation and those with or without blood. Each residual specimen was divided into two portions. One portion was treated with glacial acetic acid (GAA) and the other half remained untreated. Both aliquots were tested for high-risk HPV DNA using the Hybrid Capture 2 test. After internal validation, reflex HPV DNA testing was performed on all consecutive 1776 ASCUS specimens including 98 acid-washed bloody specimens in routine practice. RESULTS: Of the 120 specimens with paired aliquots, 117 specimens had concordant HPV DNA test results in the treated and untreated groups with a squared correlation coefficient value of 0.97 and a kappa value of 0.95. Subsequently, in the clinical setting, 43 of 98 (43.9%) acid-washed specimens and 845 of 1676 (50.4%) routine specimens with an ASCUS interpretation tested positive for high-risk HPV DNA. There was no statistically significant difference noted between these two groups with regard to age, percentage HPV DNA positivity, or viral load. CONCLUSIONS: The pretreatment of bloody specimens with GAA did not appear to significantly affect high-risk HPV DNA testing in specimens with an ASCUS interpretation.
Gravitropism is explained by the Cholodny-Went hypothesis: the basipetal flow of auxin is diverted laterally. The resulting lateral auxin gradient triggers asymmetric growth. However, the Cholodny-Went hypothesis has been questioned repeatedly because the internal auxin gradient is too small to account for the observed growth asymmetry. Therefore, an additional gradient in indolyl-3-acetic acid (IAA) sensitivity has been suggested (Brauner and Hager in Planta 51:115-147, 1958). We challenged the Cholodny-Went hypothesis for gravitropism of rice coleoptiles (Oryza sativa L.) and found it to be essentially true. However, we observed, additionally, that the two halves of gravitropically stimulated coleoptiles responded differentially to the same amount of exogenous auxin: the auxin response is reduced in the upper flank but normal in the lower flank. This indicates that the auxin-gradient is amplified by a gradient of auxin responsiveness. Hormone contents were measured across the coleoptile by a GC-MS/MS technique and a gradient of jasmonate was detected opposing the auxin gradient. Furthermore, the total content of jasmonate increased during the gravitropic response. Jasmonate gradient and increase persist even when the lateral IAA gradient is inhibited by 1-N-naphtylphtalamic acid. Flooding with jasmonate delays the onset of gravitropic bending. Moreover, a jasmonate-deficient rice mutant bends more slowly and later than the wild type. We discuss a role of jasmonate as modulator of auxin responsiveness in gravitropism.