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21.
Pigment producing in vitro cells of Vaccinium pahalae (ohelo) were tested for their ability to survive cryopreservation and
retain pigment-production capacity after encapsulation-dehydration. Preculture of cells for 6 to 8 days in a medium containing
1.0 M sucrose was essential before dehydration. Reduction of bead water content before quenching in liquid nitrogen was highly
correlated (r = 0.94) with increased survival rate in cells after cryopreservation. Dehydration of beads for 4 h was satisfactory
for survival of cells. After quenching in liquid nitrogen, colored cells became pale, but pigment content was recovered once
cells resumed growth. After three subcultures, cells regained their maximum capacity for pigment accumulation. The percentage
of colored-to-total cell volume was not influenced by cryopreservation. Encapsulation-dehydration and cryopreservation did
not diminish the capacity of cells to produce anthocyanins and other flavonoids.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
22.
JB Parentes-Vieira PV Lopes-Costa CG Pires AR dos Santos JD Pereira-Filho BB da Silva 《International Seminars in Surgical Oncology : ISSO》2007,4(1):22
Background
The objective of this study was to evaluate angiogenesis according to CD34 antigen expression in estrogen receptor (ER)-positive and negative breast carcinomas.Methods
This study comprised 64 cases of infiltrating ductal carcinoma in postmenopausal women divided into two groups: Group A: ER-positive, n = 35; and Group B: ER-negative, n = 29. The anti-CD34 monoclonal antibody was used as a marker for endothelial cells. Microvessel count was carried out in 10 fields per slide using a 40× objective lens (magnification 400×). Statistical analysis of the data was performed using Student's t-test (p < 0.05).Results
The mean number of vessels stained with the anti-CD34 antibody in the estrogen receptor-positive and negative tumors was 23.51 ± 1.15 and 40.24 ± 0.42, respectively. The number of microvessels was significantly greater in the estrogen receptor-negative tumors (p < 0.001).Conclusion
ER-negative tumors have significantly greater CD34 antigen expression compared to ER-positive tumors.23.
Sarab A. Sharaf Rida A. Shibli Mahmoud A. Kasrawi Savinaz H. Baghdadi 《Plant Cell, Tissue and Organ Culture》2012,108(3):437-444
Artemisia herba-alba, called Shih is a medicinal herbal plant found in the wilds. The biodiversity of this plant is heavily subjected to loss because
of heavy grazing, land cultivation and collection by people to be used in folk medicine. In the current study, two cryopreservation
dependent techniques to conserve the shoot-tips of in vitro grown Shih were evaluated: encapsulation- dehydration and encapsulation-
vitrification. Shoot-tips of Shih were encapsulated into sodium-alginate beads. In encapsulation- dehydration, the effect
of sucrose concentration (0.5, 0.75 or 1.0 M) and dehydration period (0, 2, 4 or 6 h) under sterile air-flow on survival and
regrowth of encapsulated shoot tips were studied. Maximum survival (100%) and regrowth (27%) rates were obtained when encapsulated
unfrozen Artemisia herba-alba shoot tips were pretreated with 0.5 M sucrose for 3 days without further air dehydration. After cryopreservation the highest
survival (40%) and regrowth (6%) rates were achieved when Artemisia herba-alba shoot tips were pretreated with 1.0 M sucrose for 3 days without further air dehydration. Viability of Artemisia herba-alba shoot tips decreased with increased dehydration period. In encapsulation-vitrification, the effect of dehydration of encapsulated
Artemisia herba-alba shoot tips with 100% PVS2 for various dehydration durations (10, 20, 30, 60 or 90 min) prior to freezing was studied. After
cryopreservation the dehydration of encapsulated and vitrified shoot tips with 100% PVS2 for 30 min resulted in 68% survival
and 12% regrowth rates. Further conservation techniques must be evaluated to increase both survival and regrowth percentages. 相似文献
24.
Soha E. Mostafa Nabila S. Karam Rida A. Shibli Feras Q. Alali 《Plant Cell, Tissue and Organ Culture》2010,103(1):111-121
A protocol for micropropagation of Arbutus andrachne from seeds was developed. Results indicated that none of the seeds cultured on Murashige and Skoog (MS) medium, with or without
plant growth regulators (PGRs), germinated. Seeds soaked in 250 mg l−1 gibberellic acid (GA3) at 4°C for 3 days, then cultured on water-agar medium containing 2.0 mg l−1 GA3 exhibited 80–100% germination and developed into usable seedlings. Shoot proliferation was tested on MS or B5 medium containing
different concentrations of cytokinin. No shoot proliferation was observed on PGR-free medium. Proliferation was more successful
on MS than on B5 medium. On both media, the most successful proliferation was obtained using zeatin as a cytokinin type. Rooting
was tested on MS medium containing different concentrations of auxin. Rooting failed on PGR-free medium and on medium containing
indole-3-acetic acid (IAA), 0.25 or 0.5 mg l−1 indole-3-butyric acid (IBA), or 0.25, 0.5 or 2.0 mg l−1 α-naphthaleneacetic acid (NAA). Rooting (40%) was most successful with 1.0 mg l−1 NAA. Rooted plantlets exhibited 80% survival in all mixtures of peatmoss and perlite, and acclimatized plants were successfully
grown in the greenhouse. Quantitative analysis of arbutin performed on in vivo and in vitro leaves using high-performance
liquid chromatography (HPLC) revealed that in vivo leaves contained higher arbutin content (0.3–0.81% w/w) than in vitro leaves
(0.09% w/w). The highest yield of arbutin in vivo was detected in leaves collected in August, and the lowest yield in leaves
collected in December. 相似文献
25.
Yeast-to-hyphal transition triggers formin-dependent Golgi localization to the growing tip in Candida albicans
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Rapid and long-distance secretion of membrane components is critical for hyphal formation in filamentous fungi, but the mechanisms responsible for polarized trafficking are not well understood. Here, we demonstrate that in Candida albicans, the majority of the Golgi complex is redistributed to the distal region during hyphal formation. Randomly distributed Golgi puncta in yeast cells cluster toward the growing tip during hyphal formation, remain associated with the distal portion of the filament during its extension, and are almost absent from the cell body. This restricted Golgi localization pattern is distinct from other organelles, including the endoplasmic reticulum, vacuole and mitochondria, which remain distributed throughout the cell body and hypha. Hyphal-induced positioning of the Golgi and the maintenance of its structural integrity requires actin cytoskeleton, but not microtubules. Absence of the formin Bni1 causes a hyphal-specific dispersal of the Golgi into a haze of finely dispersed vesicles with a sedimentation density no different from that of normal Golgi. These results demonstrate the existence of a hyphal-specific, Bni1-dependent cue for Golgi integrity and positioning at the distal portion of the hyphal tip, and suggest that filamentous fungi have evolved a novel strategy for polarized secretion, involving a redistribution of the Golgi to the growing tip. 相似文献
26.
Muhammad Riaz Rahman Qadir Muhammad Tahir Akhtar Muhammad Misbah ur Rehman Farooq Anwar Rida Eman Muhammad Fayyaz ur Rehman Muhammad Safwan Akram 《化学与生物多样性》2023,20(1):e202200537
The present study investigates the chemical composition, antioxidant and antimicrobial bioactivities of essential oil and hexane extract from Citrus limon leaves. The isolation of essential oil was carried out using the Clevenger apparatus. The percentage yield of essential oil and hexane extract from Citrus limon leaves was 0.59 and 0.50 %, respectively. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay highlighted that Citrus limon leaves essential oil (CLEO) and hexane extract exhibited the significant antioxidant potential of 69.64 and 67.55 %, respectively, compared to the BHT standard. Similarly, a significant inhibition in linoleic acid peroxidation was recorded in both CLEO (81.93 %) and hexane extract (50.34 %). Characterization of chemical constituents in CLEO and extract was executed using GC/MS, where Limonene was detected as a major compound in CLEO (60.52 %) and hexane extract (73.62 %). The haemolytic activity ranged from 2.46 to 5.75 % revealing negligible cytotoxicity of CLEO and hexane extract. In silico studies agree with the in vitro antimicrobial studies, where vinimalol, taraxasterol, and moretenol present in CLEO showed strong interactions/inhibition against dihydroorotase and DNA gyrase from E. coli, and the tyrosyl-tRNA synthetase and DNA gyrase from S. aureus. Based on the current data, it may be concluded that both CLEO and hexane extract possessed significant bioactivities, such as antimicrobial and antioxidant activity, with minimal cytotoxicity. 相似文献
27.
Somatic embryogenesis in the endemic black iris 总被引:2,自引:0,他引:2
Apple shoot cultures accumulate phenolic acids, flavonols, catechins, and procyanidins. Increasing the sucrose content and reducing the macronutrient content of culture media both resulted in an enhanced content of phenolic substances. The qualitative composition of the substances was affected as well. Morphology of the shoots, preculture and time of sampling in the subculture interval influenced the reaction pattern. 相似文献
28.
Naegleria fowleri is a parasitic unicellular free living eukaryotic amoeba. The parasite spreads through contaminated water and
causes primary amoebic meningoencephalitis (PAM). Therefore, it is of interest to understand its molecular pathogenesis. Hence,
we analyzed the parasite genome for miRNAs (microRNAs) that are non-coding, single stranded RNA molecules. We identified
245 miRNAs using computational methods in N. fowleri, of which five miRNAs are conserved. The predicted miRNA targets were
analyzed by using miRanda (software) and further studied the functions by subsequently annotating using AmiGo (a gene
ontology web tool). 相似文献
29.
30.
A simple method to separate base population and segregation effects in genomic relationship matrices
Laura Plieschke Christian Edel Eduardo CG Pimentel Reiner Emmerling J?rn Bennewitz Kay-Uwe G?tz 《遗传、选种与进化》2015,47(1)