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排序方式: 共有176条查询结果,搜索用时 15 毫秒
71.
Mani Suganya Balasubramanian Mythili Gnanamangai Chandramohan Govindasamy Mohamed Farouk Elsadek Arivalagan Pugazhendhi Veeramani Chinnadurai Arokiyaraj Selvaraj Balasubramani Ravindran Soon Woong Chang Ponnusamy Ponmurugan 《Saudi Journal of Biological Sciences》2019,26(4):767-776
The present study reports the validation of cancer nanotherapy using proanthocyanidin (PAC). Nowadays, in vitro and in vivo deliveries of nanoparticle (NPs) drugs have been paid more attention, intensively. Moreover, the current chemotherapeutic drugs have few first rate drawbacks including lack of specificity and requirement of excessive drug doses. To overcome this problem of chemotherapy, the attainment of high drug loading in combination with degradable polymer nanoparticles (for instance,chitosan) is a trending research in cancer biology. Hence, in this study, the synthesized PAC-AgNPs were successfully crosslinked with chitosan nanoparticles (CS-PAC-AgNPs), which were found to be spherical or polygonal in shape with a median size of 70.68 nm and 52.16 nm as observed by FTIR, FESEM and TEM analysis; thus, being suitable for drug delivery. CS-PAC-AgNPs were taken up via endocytosis by cancer cells and enabled the release cytochrome-C from mitochondria, followed by dysregulation of anti-apoptotic protein Bcl2 family, inducing the apoptotic mediated activation of caspase 9 and 3. To identify the genotoxicity of the synthesized CS-PAC-AgNPs, the mortality, hatching rate, malformation and abnormalities of embryo/larvae of the vertebrate zebra fish model (Danio rerio) were observed in a dose-time-dependent manner. This improved cancer nanotherapy can thus be utilized as a novel nanocombination for inducing apoptosis in vitro and in vivo. 相似文献
72.
Thebirth season of Formosan macaqueM. cyclopis during our study started in February and ended in August with a peak in the second half of April and the first half of May.
The average birth rate was 82%±21 for 114 females with four years of breeding records. Our study reports that a time span
of one year between births can be considered as the norm for the wildM. cyclopis. Of the 288 inter-birth intervals (IBI), 88.5% showed a 1-year interval (mean 364±SD 29 days); 11% showed 2-year interval
(727±36 days); and 1% (2 females) had 3-year interval (range 1030–1040 days). The IBI for females that had infant loss within
six months of life were the shortest. But there was no significant difference from that of females that had stillbirth (p>0.9) and infant that survived for first six months of life (p>0.06). However, among 255 cases of 1-year IBI, stillbirth or following infant loss within six months of life did significantly
shorten IBI for ten days (F
1,253=5.74,p<0.05). 相似文献
73.
Ilangovan Govindasamy Li Haiquan Zweier Jay L. Kuppusamy Periannan 《Molecular and cellular biochemistry》2002,(1):393-398
Solid tumors are characterized by a number of physiological properties such as occurrence of significant hypoxia, large amounts of cellular reducing equivalents, compromised blood-flow and low pH, all of which are distinctly different from normal tissues. Tumor therapeutic regimens such as radiation or chemotherapy attempt to exploit these physiological differences between normal and malignant tissue. Thus, methods that can detect these subtle differences would greatly aid in devising appropriate treatment strategies. Low-frequency in vivo electron paramagnetic resonance (EPR) spectroscopy is capable of providing non-invasive measurements of these parameters in tumors. This requires the use of appropriate exogenously injected free radical reporter molecules (probes), such as nitroxides. In the present study we performed measurements of nitroxide metabolism in RIF-1 murine tumors, in vivo, and demonstrated that the rate of nitroxide decay correlated with the tumor redox environment. The results showed the existence of significantly higher reducing environment in the tumor tissue compared to normal tissue. The dependence of the tumor redox status on the intracellular GSH levels and tissue oxygenation was investigated. The measurement of redox status and its manipulation may have important implications in the understanding of tumor growth and therapy. 相似文献
74.
Hernáindez-Falcón J Basu AC Govindasamy S Kravitz EA 《Cellular and molecular neurobiology》2005,25(2):329-343
Agonistic contests between lobsters housed together in a confined space progress through encounters of increasing intensity until a dominance relationship is established. Once this relationship is established, losing animals continually retreat from the advances of winners.These encounters are likely to consume much energy in both winning and losing animals. Therefore, one might expect involvement of many physiological systems before, during and after fights. Here, we report effects of agonistic encounters on cardiac frequency in winning and losing adult lobsters involved in dyadic interactions.The results show that: (i) small but significant increases in heart rate are observed upon chemical detection of a conspecific; (ii) during agonistic interactions, further increases in heart rate are seen; and (iii) ultimate winners exhibit greater increases in heart rate lasting longer periods of time compared to ultimate losers. Heart rate in winners remains elevated for at least 15 min after the contests have ended and animals have been returned to their home tanks. Reduced effects are seen in second and third pairings between familiar opponents.The sustained changes in heart rate that we observe in winning lobsters may result from hormonal modulation of cardiac function related to the change in social status brought about by contest outcome. 相似文献
75.
Structure of adeno-associated virus type 4 总被引:2,自引:0,他引:2
Padron E Bowman V Kaludov N Govindasamy L Levy H Nick P McKenna R Muzyczka N Chiorini JA Baker TS Agbandje-McKenna M 《Journal of virology》2005,79(8):5047-5058
Adeno-associated virus (AAV) is a member of the Parvoviridae, belonging to the Dependovirus genus. Currently, several distinct isolates of AAV are in development for use in human gene therapy applications due to their ability to transduce different target cells. The need to manipulate AAV capsids for specific tissue delivery has generated interest in understanding their capsid structures. The structure of AAV type 4 (AAV4), one of the most antigenically distinct serotypes, was determined to 13-A resolution by cryo-electron microscopy and image reconstruction. A pseudoatomic model was built for the AAV4 capsid by use of a structure-based sequence alignment of its major capsid protein, VP3, with that of AAV2, to which AAV4 is 58% identical and constrained by its reconstructed density envelope. The model showed variations in the surface loops that may account for the differences in receptor binding and antigenicity between AAV2 and AAV4. The AAV4 capsid surface topology also shows an unpredicted structural similarity to that of Aleutian mink disease virus and human parvovirus B19, autonomous members of the genus, despite limited sequence homology. 相似文献
76.
Effects of barrel temperature (81–149°C) and screw speed (315–486rpm) on extrusion processing of sago starch in a co-rotating twin-screw extruder under a high moisture system (34–47%) were investigated using response surface methodology. Structural changes were characterised by measuring water solubility index (WSI), water absorption index (WAI), degree of gelatinisation (DG), dextrose equivalent (DE) and high performance size-exclusion chromatography (HPSEC) profiles of the extradates. Thermomechanical processing of sago starch in the twin-screw extruder at the high moisture (34–47%) system led to shearinduced limited degradation and starch phase transitions (a composite melting gelatinisation process). Strong positive correlations between WAI, WSI and DG showed that gelatinisation was the fundamental mechanism in this high moisture system rather than dextrinisation. Processing-induced solubility increased at the expense of water absorption. Low WSI (4.5–18.1%) is ascribed to the presence of structures of either granular crystallite remnants or rearrangement of bonds during extrusion. 相似文献
77.
78.
Antitumor effect of echitamine chloride on methylcholonthrene induced fibrosarcoma in rats. 总被引:1,自引:0,他引:1
Echitamine chloride a plant alkaloid from Alstonia scholaris has been used to examine the anticancer effects on methylcholanthrene-induced fibrosarcoma. Echitamine chloride dissolved in saline (10 mg/kg body weight) and injected subcutaneously for 20 days in fibrosarcoma rats has exhibited significant regression in tumor growth. The altered activities of plasma and liver transaminases and gamma-glutamyl transpeptidase and lipid peroxidation in fibrosarcoma have been corrected to near normal after echitamine chloride treatment. The decreased liver glutathione content and the lowered activities of glutathione peroxidase, superoxide dismutase and catalase have also been reversed to near normals after echitamine chloride treatment. 相似文献
79.
Saraswathi V Mathuram V Subramanian S Govindasamy S 《Cancer biochemistry biophysics》1999,17(1-2):79-88
Echitamine chloride (EC), an indole alkaloid, extracted from the bark of Alstonia scholaris has got highly promising anticancer effect. The effect of this drug on the microsomal drug detoxifying system was studied in sarcoma-180 induced mice. When given sub-cutaneously at a dosage of 5 mg/kg body weight, it was able to alter the impaired drug detoxifying system which was observed in the Sarcoma-180 bearing mice. The levels of microsomal protein, Cyt-P450, Cyt-b5, NADH-Cyt-C-reductase, NADPH-Cyt-C-reductase, and glu-6 phosphatase were determined. The levels of these drug metabolizing enzymes were decreased in S-180 bearing mice. EC treatment corrected to near normal levels of these enzymes and microsomal hemeproteins. In order to understand the mechanism responsible for the decreased protein level and its normalization after treatment with EC, 3H-Phenylalanine incorporation study was carried out. From the results, it is observed that the synthesis of apoproteins is also altered in tumor-bearing animals. All these changes which were observed in tumor-bearing animals were corrected to near normal levels after treatment with EC. 相似文献
80.
Nareshwaran Gnanasegaran Vijayendran Govindasamy Sabri Musa Noor Hayaty Abu Kasim 《Cytotechnology》2016,68(2):343-353
Among the debilitating diseases, neurological related diseases are the most challenging ones to be treated using cell replacement therapies. Recently, dental pulp stem cells (SHED) were found to be most suitable cell choice for neurological related diseases as evidenced with many preclinical studies. To enhance the neurological potential of SHED, we recapitulated one of the pharmacological therapeutic tools in cell replacement treatment, we pre-conditioned dental pulp stem cells (SHED) with culture medium of ReNCell VM, an immortalized neuron progenitor cell, prior to neurogenesis induction and investigated whether this practice enhances their neurogenesis potential especially towards dopaminergic neurons. We hypothesed that the integration of pharmacological practices such as co-administration of various drugs, a wide range of doses and duration as well as pre-conditioning into cell replacement may enhance the efficacy of stem cell therapy. In particular, pre-conditioning is shown to be involved in the protective effect from some membrano-tropic drugs, thereby improving the resistance of cell structures and homing capabilities. We found that cells pre-treated with ReNCell VM conditioned medium displayed bipolar structures with extensive branches resembling putative dopaminergic neurons as compared to non-treated cells. Furthermore, many neuronal related markers such as NES, NR4A2, MSI1, and TH were highly expressed (fold changes > 2; p < 0.05) in pre-treated cells. Similar observations were detected at the protein level. The results demonstrate for the first time that SHED pre-conditioning enhances neurological potential and we suggest that cells should be primed to their respective environment prior to transplantation. 相似文献