Thermodynamics of single strand DNA base stacking

The thermodynamics of the stacking to unstacking transitions of 24 single-stranded DNA sequences (ssDNA), 10-12 bases in length, in sodium phosphate buffer were determined from 10 to 95 degrees C, using differential scanning calorimetry (DSC). An additional 22 ssDNA sequences did not exhibit an S<-->U transition in this temperature range. The transition properties of the ssDNA sequences with 相似文献   

Fine needle aspiration cytology of epithelioid angiosarcoma: a case report

BACKGROUND: Malignant vascular tumors are rare. Few studies have described cytomorphologic features of hemangioendothelioma and angiosarcoma on fine needle aspiration cytology (FNAC). Malignant vascular tumor with epithelioid morphology can create diagnostic difficulty, as the cytology may simulate that in other nonvascular malignant tumors. We describe epithelioid angiosarcoma, diagnosed on FNAC, in which a differential diagnosis of histiocytosis and inflammatory granulation tissue was considered. CASE: A 20-year-old man presented with forehead and scalp swellings. The forehead lesion was radiologiocally associated with a lytic lesion in the bone. FNA resulted in high cellular yield, and smears revealed prominent vascular pattern with endothelial cell atypia and histiocytoid/epithelioid neoplastic cells, occasional mitotic figures and a few cells displaying nuclear grooving. Smear background showed a significant number of neutrophils. Epithelioid hemangioendothelioma/angiosarcoma, histiocytosis and inflammatory granulation tissue were considered. A cytologic diagnosis of epithelioid angiosarcoma/epithelioid hemangioendothelioma was suggested and confirmed on histopathologic and immunohistochemical examination. CONCLUSION: Cellular aspirates from malignant epithelioid endothelial tumors involving bone may be cytologically mistaken for histiocytosis and, rarely, inflammatory granulation tissue. However, prominent vascular pattern with striking endothelial cell atypia, presence of mitotic figures and careful search for presence of endothelial differentiation are helpful in accurate cytologic diagnosis.     

Bacillus coagulans Unique IS2 in Constipation: A Double-Blind,Placebo-Controlled Study

Functional constipation has a high prevalence in both adults and children affecting quality of life. Evidence suggests that probiotics can reduce the sympt     

Altered dopamine transporter function and phosphorylation following chronic cocaine self-administration and extinction in rats

Cocaine binds with the dopamine transporter (DAT), an effect that has been extensively implicated in its reinforcing effects. However, persisting adaptations in DAT regulation after cocaine self-administration have not been extensively investigated. Here, we determined the changes in molecular mechanisms of DAT regulation in the caudate-putamen (CPu) and nucleus accumbens (NAcc) of rats with a history of cocaine self-administration, followed by 3 weeks of withdrawal under extinction conditions (i.e., no cocaine available). DA uptake was significantly higher in the CPu of cocaine-experienced animals as compared to saline-yoked controls. DAT V_max was elevated in the CPu without changes in apparent affinity for DA. In spite of elevated CPu DAT activity, total and surface DAT density and DAT-PP2Ac (protein phosphatase 2A catalytic subunit) interaction remained unaltered, although p-Ser- DAT phosphorylation was elevated. In contrast to the CPu, there were no differences between cocaine and saline rats in the levels of DA uptake, DAT V_max and K_m values, total and surface DAT, p-Ser-DAT phosphorylation, or DAT-PP2Ac interactions in the NAcc. These results show that chronic cocaine self-administration leads to lasting, regionally specific alterations in striatal DA uptake and DAT-Ser phosphorylation. Such changes may be related to habitual patterns of cocaine-seeking observed during relapse.     

Estimation of endogenous indole-3-acetic acid in leaf explants and a protocol for direct regeneration in Lilium cv. Pavia

In Vitro Cellular & Developmental Biology - Plant - A method for regeneration via direct organogenesis in Lilium cv. Pavia using leaf primary explants has been established. Outer leaves from in...     

Alpha-adrenergic receptor blocking effect of Cleistanthus collinus (Roxb.) Benth. and Hook f. leaf extract on guinea pig isolated smooth muscle preparations

Aqueous extract of C. collinus leaves inhibited norepinephrine induced contraction in guinea pig vas deferens and aortic strip in a dose-dependent manner. Inhibition of acetylcholine induced contraction in ileum was dose independent. C. collinus extract per se had no effect on isolated guinea pig vas deferens and aortic strip, but inhibited norepinephrine induced contraction in a dose-dependent manner probably by its antagonist action on alpha-adrenergic receptor. It had inconsistent effect on guinea pig ileum in vitro preparation.     

A multicarotenoid beadlet for human nutrition - proof of concept of in vitro timed release

Since the 1980's when the predominate focus of study and use of carotenoids in human nutritional formulations was solely on beta-carotene, there has been a steady increase in research aimed to understand the role of a wide variety of carotenoids in human health. This work has increasingly demonstrated the benefits of a number of carotenoids, and there has been a corresponding increase in the number of carotenoids provided in nutritional supplements (multicarotenoids). Numerous published observations in both human and animal studies suggest significant interaction and competition between various carotenoids during absorption and metabolism, resulting in the inhibition of uptake of one over the other. This competition has the end result of reducing the beneficial effects of the inhibited carotenoid. To limit such competition and maximize carotenoid uptakes, a layered beadlet was designed to release a defined ratio of carotenoids sequentially. Preliminary dissolution testing is presented showing the release profile in simulated digestive conditions of a combination of beta-carotene, alpha carotene, lutein, zeaxanthin, lycopene and astaxanthin derived from natural sources. Comparison is made to an immediate release beadlet formulation using the same combination of carotenoids. These results will be used to guide proof of concept clinical testing for effectiveness in humans.     

Mycoremediation of Endosulfan and Its Metabolites in Aqueous Medium and Soil by Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9

Microbial degradation offers an efficient and ecofriendly approach to remove toxicants from the contaminated environments. Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9 were capable of degrading endosulfan and their metabolites which were isolated through enrichment technique. Both the strains were able to withstand an exposure of 1300 mg/L and showed luxuriant growth at 1000 mg/L of endosulfan. The change in pH in the culture broth was from 6.8 to 3.4 and 3.8 during growth kinetic studies of JAS6 and JAS9 strains, respectively upon biological degradation of endosulfan. The degradation of endosulfan by JAS6 and JAS9 strains were examined by HPLC. The biodegradation rate constant (k) and the initial concentration were reduced by 50% (DT₅₀) which was determined by first and pseudo first order kinetic models. In the present investigation it has been revealed that Botryosphaeria laricina JAS6 and Aspergillus tamarii JAS9 possessing endosulfan degrading capability are being reported for the first time. These findings confirm the degradation of endosulfan by JAS6 and JAS9 strains which were accompanied by significant reduction in the toxicity and could be used as remedial measure in contaminated environments.