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51.
Epidemiological evidence demonstrates positive correlation between environmental and occupational arsenic or fluoride exposure
and risk to various cardio-respiratory disorders. Arsenic-exposure has been associated with atherosclerosis, hypertension,
cerebrovascular diseases, ischemic heart disease, and peripheral vascular disorders, whereas Fluoride-exposure manifests cardiac
irregularities and low blood pressure (BP). Present study aims to study the combined effects of these toxicants on various
cardio-respiratory variables in male rats. Single intravenous (i.v.) dose of arsenic (1, 5, 10 mg/kg) or fluoride (5, 10,
20, 36.5 mg/kg) either alone or in combination were administered. Individual exposure to arsenic or fluoride led to a significant
depletion of mean arterial pressure, heart rate (HR), respiration rate and neuromuscular (NM) transmission in a dose-dependent
manner. These changes were accompanied by increased levels of blood reactive oxygen species (ROS) and decreased glutathione
(GSH) concentrations. An increase in the blood acetyl cholinesterase (AChE) activity was observed in both arsenic or fluoride
exposed rats. These changes were significantly more pronounced in arsenic-exposed animals than in fluoride. During combined
exposure to arsenic (5 mg/kg) + fluoride (20 mg/kg) or arsenic (10 mg/kg) + fluoride (36.5 mg/kg) the toxic effects were more
pronounced compared to individual toxicities of arsenic or fluoride alone. However, combined exposure to arsenic (5 mg/kg) + fluoride
(36.5 mg/kg) resulted in antagonistic effects on variables suggestive of altered cardio-respiratory function and oxidative
stress. The results from the present study suggest that arsenic or fluoride individually demonstrate cardio-respiratory failure
at all doses whereas during combination exposure these toxins show variable toxicities; both synergistic and antagonistic
effects depending upon the dose. Moreover, it may be concluded that arsenic and/or fluoride cardio-respiratory toxicity may
be mediated via oxidative stress. However, these results are new in the discipline thus requires further exploration. 相似文献
52.
Marine derivatives are of great pharmaceutical interest as inhibitory compound and search of bioactive compounds from Marine
organism which is relatively new to medicinal chemistry. Our main aim in the study is to screen possible inhibitors against
CCR5 which acts as co-receptor M-tropic HIV-1, through virtual screening of 122 Marine derived compounds from various
organisms known to have biological activity. Homology Model of CCR5 was constructed using MODELLER and the Model was energy
minimized and validated using PROCHECK to obtain a stable structure, which was further used for virtual screening of Marine
derived compounds through molecular Docking studies using GOLD. The Docked complexes were validated and Enumerated based on
the GOLD Scoring function to pick out the best Marine inhibitor based on GOLD score. Thus from the entire 122 Marine
compounds which were Docked, we got best 4 of them with optimal GOLD Score.
(LAMIVUDINE: 45.0218, BATZELLINE-D: 44.3852.ACYCLOVIR: 43.1362 and THIIOACETAMIDE: 42.7412) Further the Complexes were analyzed
through LIGPLOT for their interaction for the 4 best docked Marine compounds. Thus from the Complex scoring and binding ability its
deciphered that these Marine compounds could be promising inhibitors for M-tropic HIV-1 using CCR5 as Drug target yet pharmacological
studies have to confirm it. 相似文献
53.
R. Mulherkar S. J. Desai R. S. Rao A. S. Wagle M. G. Deo 《Histochemistry and cell biology》1991,96(4):367-370
Summary Enhancing factor (EF), a 14 kDa protein, isolated from mouse small intestines, has been reported from this laboratory. Based on our earlier studies EF has been implicated in cell proliferation. Preliminary immunohistochemical studies have shown EF to be localized in the Paneth cells of small intestines. In this paper we report the tissue distribution of EF using conditions optimized for immunohistochemical staining. In addition, the data are supported by northern blot analysis using a nick translated cDNA probe specific for EF. The results indicate that EF gene is actively transcribed mainly in the intestines. The chief source of synthesis of EF appears to be the Paneth cells located at the base of the crypts of Lieberkühn. 相似文献
54.
55.
56.
Variations among cell lines in the synthesis of sphingolipids in de novo and recycling pathways 总被引:1,自引:0,他引:1
There are several pathways for the incorporation of sugars into
glycosphingolipids (GSL). Sugars can be added to ceramide that contains
sphinganine (dihydrosphingosine) synthesized de novo (pathway 1), to
ceramide synthesized from sphingoid bases produced by hydrolysis of
sphingolipids (pathway 2), and into GSL recycling from the endosomal
pathway through the Golgi (pathway 3). We reported previously the
surprising observation that SW13 cells, a human adrenal carcinoma cell
line, synthesize most of their GSL in pathway 2. We now present data on the
synthesis of GSL in four additional cell lines. Approximately 90% of sugar
incorporation took place in pathway 2, and 10% or less in pathway 1, in
human foreskin fibroblasts and NB41A3 neuroblastoma cells. In contrast,
approximately 50-90% of sugar incorporation took place in pathway 1 in
C2C12 myoblasts. The C2C12 cells divide more rapidly and synthesize 10-14
times as much GSL as the other three cell lines. In C6 glioma cells,
approximately 30% of sugar incorporation occurred in pathway 1 and 60% in
pathway 2. There was no relation between the utilization of pathways for
GSL and sphingomyelin synthesis in foreskin fibroblasts and C2C12 cells. In
both cells pathways 1 and 2 each accounted for 50% of incorporation of
choline into sphingomyelin. In five of the six cell lines that we have
studied, most GSL synthesis takes place in pathway 2. We suggest that when
the need for synthesis is relatively low, as in slowly dividing cells, GSL
are synthesized predominantly from sphingoid bases salvaged from the
hydrolytic pathway. When cells are dividing more rapidly, the need for
increased synthesis is met by upregulating the de novo pathway.
相似文献
57.
Enhancing Factor (EF) is a 14 kDa protein isolated from mouse small intestines, which enhances the binding of 125I-EGF to A431 cells. This observation as well as our earlier in vitro studies have indicated that EF is a modulator of EGF. In adult mice, localization of EF by immunohistochemistry shows it is present predominantly in the Paneth cells of the small intestines and to a lesser extent in the stomach and colon. This study of the ontogeny of EF shows that the appearance of the protein coincides with the appearance of mature Paneth cells. In new born mouse skin EF is localized in the hair follicles in the first hair cycle from day 2 to day 8. It is however absent in the adult skin. Thus EF is associated with tissues which have a high growth rate. 相似文献
58.
This article reports a new application of material and energy accounting techniques to characterize and quantify the relationships between material input (and the related energy flows and emissions) and the services provided (i.e., material input per service unit [MIPS]) at the neighborhood level. The case study focuses on China's small residential district (SRD). It is concluded that linking a service (in this case, residential function) enabled by a given product (neighborhood development) to the amount of materials, energy, and emissions used or produced in creating that product offers a potential way to reduce the environmental impact of that service through more efficient use of materials, enlarged service scales, and improved buying decisions. 相似文献
59.
Deo R. Singh Fozia Ahmed Christopher King Nisha Gupta Matt Salotto Elena B. Pasquale Kalina Hristova 《The Journal of biological chemistry》2015,290(45):27271-27279
The EphA2 receptor tyrosine kinase promotes cell migration and cancer malignancy through a ligand- and kinase-independent distinctive mechanism that has been linked to high Ser-897 phosphorylation and low tyrosine phosphorylation. Here, we demonstrate that EphA2 forms dimers in the plasma membrane of HEK293T cells in the absence of ephrin ligand binding, suggesting that the current seeding mechanism model of EphA2 activation is incomplete. We also characterize a dimerization-deficient EphA2 mutant that shows enhanced ability to promote cell migration, concomitant with increased Ser-897 phosphorylation and decreased tyrosine phosphorylation compared with EphA2 wild type. Our data reveal a correlation between unliganded dimerization and tumorigenic signaling and suggest that EphA2 pro-tumorigenic activity is mediated by the EphA2 monomer. Thus, a therapeutic strategy that aims at the stabilization of EphA2 dimers may be beneficial for the treatment of cancers linked to EphA2 overexpression. 相似文献
60.
BK McFarlin AS Venable RR Williams AW Jackson 《Biology of sport / Institute of Sport》2015,32(1):11-14
Exercising or working in a hot, humid environment can results in the onset of heat-related illness when an individual''s temperature is not carefully monitored. The purpose of the present study was to compare three techniques (data loggers, thermal imaging, and wired electrodes) for the measurement of peripheral (bicep) and central (abdominal) skin temperature. Young men and women (N = 30) were recruited to complete the present study. The three skin temperature measurements were made at 0 and every 10-min during 40-min (60% VO2max) of cycling in a hot (39±2°C), humid (45±5% RH) environment. Data was statistically analyzed using the Bland-Altman method and correlation analysis. For abdominal skin temperature, the Bland-Altman limits of agreement indicated that data loggers (1.5) were a better index of wired than was thermal imaging (3.5), For the bicep skin temperature the limits of agreement was similar between data loggers (1.9) and thermal (1.9), suggesting the both were suitable measurements. We also found that when skin temperature exceeded 35°C, we observed progressively better prediction between data loggers, thermal imaging, and wired skin sensors. This report describes the potential for the use of data loggers and thermal imaging to be used as alternative measures of skin temperature in exercising, human subjects. 相似文献