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101.
The effect of bromocriptine, a dopamine receptor agonist, has been studied on the aspirin, phenylbutazone and reserpine induced gastric ulcers in rats. A single dose of bromocriptine 4 mg/kg s.c. produced a significant exacerbation of gastric ulcers induced by all the three ulcerogenic drugs, whereas in the same dose administered once daily for 5 consecutive days, it produced a marked protective effect in all the models. A review of the literature shows that different mechanisms may be involved in the opposite effects of acutely and chronically administered bromocriptine observed in this study. The study also points towards a role of dopamine in the pathogenesis of gastroduodenal ulceration. 相似文献
102.
Cyclin D1 genetic heterozygosity regulates colonic epithelial cell differentiation and tumor number in ApcMin mice 总被引:1,自引:0,他引:1 下载免费PDF全文
Hulit J Wang C Li Z Albanese C Rao M Di Vizio D Shah S Byers SW Mahmood R Augenlicht LH Russell R Pestell RG 《Molecular and cellular biology》2004,24(17):7598-7611
Constitutive β-catenin/Tcf activity, the primary transforming events in colorectal carcinoma, occurs through induction of the Wnt pathway or APC gene mutations that cause familial adenomatous polyposis. Mice carrying Apc mutations in their germ line (ApcMin) develop intestinal adenomas. Here, the crossing of ApcMin with cyclin D1−/− mice reduced the intestinal tumor number in animals genetically heterozygous or nullizygous for cyclin D1. Decreased tumor number in the duodenum, intestines, and colons of ApcMin/cyclin D1+/− mice correlated with reduced cellular proliferation and increased differentiation. Cyclin D1 deficiency reduced DNA synthesis and induced differentiation of colonic epithelial cells harboring mutant APC but not wild-type APC cells in vivo. In previous studies, the complete loss of cyclin D1 through homozygous genetic deletion conveyed breast tumor resistance. The protection of mice, genetically predisposed to intestinal tumorigenesis, through cyclin D1 heterozygosity suggests that modalities that reduce cyclin D1 abundance could provide chemoprotection. 相似文献
103.
Sammyia Jannat Mahmood ul Hassan Muhammad Kausar Nawaz Shah Asad Hussain Shah Anila Fariq Suman Mehmood Abdul Qayyum Amal F. Gharib Ahmad El Askary 《Saudi Journal of Biological Sciences》2022,29(4):3033
Peanut, the only cash crop of rainfed areas of Pakistan, is facing immense challenges due to global warming. Climatic factors particularly the temperature fluctuations and rain pattern shift significantly impact the production and yield of peanut and unavailability of resilient varieties exacerbate this impact. To deal with the cropping pattern change and yield losses, due to climate vagaries, a study was conducted to develop early maturing hybrids using line into tester mating design. The F1 hybrids from the parental lines were produced in the year 2018 using Line × Tester mating design and then grown in the field in the year 2019 for further evaluation. The hybrids were evaluated based on the early maturity and yield-related attributes in comparison with the parental lines. Based on the general combining ability estimate, line V-3 (Golden), was found as best parent with highly significant values for plant height, days to peg formation, days to maturity, number of pegs per plant, number of pods per plants, number of seeds per plant, 100 pod weight 100 seed weight. Similarly, tester V-7 (PI 635006 01 SD) showed highly significant results of GCA for days to germination, day to 50% flowering, plant height, days to peg formation, days to maturity, number of pegs per plant, number of pods per plants, number of seeds per plant, 100 kernel weight, shelling percentage. All the combinations were evaluated for specific combining ability and significant results were observed for V-3 × V-4 (Golden × PI 619175 01 SD) and V-1 × V-6 (BARI-2000 × PI 564846 01 SD) by developing or maturity and yield-related attributes. The hybrid combinations V-3 × V-5 (Golden × PI 635006 01 SD) followed by V-3 × V-6 showed highly significant results for mid parent heterosis and better parent heterosis for days to 50% flowering, plant height, days to peg formation, number of pegs, days to maturity, number of mature seeds per plant, shelling ratio, 100 pod weight and 100 kernel weight. These parents and hybrid combinations with early maturity genes and high yield attributes can further be used for the development of short duration variety. 相似文献
104.
The activities of lactase, sucrase, alkaline phosphatase (AP) and y-glutamyl transpeptidase (gamma-GTP) were studied in the intestinal brush border membranes of pups born to rat mothers exposed to ethanol (1 ml of 30% ethanol daily during gestation) at different days of postnatal development. The activities of lactase (at day 4-20) and sucrase (at day 20-30) were considerably reduced in response to prenatal exposure to ethanol, while AP (at day 4-30) and gamma-GTP activities were significantly enhanced (p < 0.05) at day 4, 8, 14 and 20, but there was no significant difference by day 30 of postnatal development. The observed changes in enzyme activities were corroborated by Western blot analysis of lactase, sucrase and AP. Kinetic studies revealed a change in Vmax without affecting apparent Km of enzymes under these conditions. The present findings suggest that in utero ethanol exposure to rats is embryotoxic and affects the postnatal development of various brush border enzymes, which persist long after the ethanol was withdrawn prior to birth. 相似文献
105.
Watson JL Ansari S Cameron H Wang A Akhtar M McKay DM 《American journal of physiology. Gastrointestinal and liver physiology》2004,287(5):G954-G961
A characteristic of many enteropathies is increased epithelial permeability, a potentially pathophysiological event that can be evoked by T helper (Th)-1 (i.e., IFN-gamma) and Th2 (i.e., IL-4) cytokines and bacterial infection [e.g., enteropathogenic Escherichia coli (EPEC)]. The green tea polyphenol (-)-epigallocatechin gallate (EGCG) has immunosuppressive properties, and we hypothesized that it would ameliorate the increased epithelial permeability induced by IFN-gamma, IL-4, and/or EPEC. EGCG, but not the related epigallocatechin, completely prevented the increase in epithelial (i.e., T84 cell monolayer) permeability caused by IFN-gamma exposure as gauged by transepithelial resistance and horseradish peroxidase flux; EGCG did not alleviate the barrier disruption induced by IL-4 or EPEC. IFN-gamma-treated T84 and THP-1 (monocytic cell line) cells displayed STAT1 activation (tyrosine phosphorylation on Western blot analysis, DNA binding on EMSA) and upregulation of interferon response factor-1 mRNA, a STAT1-dependent gene. All three events were inhibited by EGCG pretreatment. Aurintricarboxylic acid also blocked IFN-gamma-induced STAT1 activation, but it did not prevent the increase in epithelial permeability. Additionally, pharmacological blockade of MAPK signaling did not affect IFN-gamma-induced epithelial barrier dysfunction. Thus, as a potential adjunct anti-inflammatory agent, EGCG can block STAT1-dependent events in gut epithelia and monocytes and prevent IFN-gamma-induced increased epithelial permeability. The latter event is both a STAT1- and MAPK-independent event. 相似文献
106.
Faruqi SA Prescott HM Ali T Noumoff JS 《Journal of the Association of Genetic Technologists》2004,30(4):146-148
We have devised a new cell culture method where two types of culture plates made of normal tissue culture plastic (NTCP) and Primaria(TM), and two media, RPMI-1640 and a serum-free media LHC-9(TM), are used in combination with an in situ harvest. Multiple culture conditions in combination with in situ harvest has yielded many more clones for karyotyping than was possible with previous methods. Cells were cultured in 60 mm Petri plates instead of flasks and harvested in situ. Chromosome banding was performed using a highly purified trypsin "Enzar-T(TM)" and Leishman stain instead of ordinary trypsin and Giemsa stain. These modifications have increased the number of clones retrieved, rate of culture success, and quality of karyotypes in solid tumors. 相似文献
107.
Multiple,independently regulated pathways of cholesterol transport across the intestinal epithelial cells 总被引:3,自引:0,他引:3
The present study provides a new understanding about the mechanisms involved in cholesterol absorption by the intestinal cells. Contrary to general belief, our data show that newly absorbed cholesterol is neither immediately available for secretion with apoB lipoproteins nor exclusively secreted as part of chylomicrons. Based on our data, cholesterol transport by enterocytes can be broadly classified into two independently modulated, apoB-dependent and -independent, pathways. Cholesterol secretion by the apoB-dependent pathway is induced by oleic acid, is repressed by microsomal triglyceride transfer protein inhibitors, and occurs only with larger apoB-containing lipoproteins. ApoB-independent pathways do not require microsomal triglyceride transfer protein and involve efflux mediated by ABCA1, high density lipoprotein assembly, and possibly other unknown mechanisms. There are at least two different metabolic pools of cholesterol. The newly absorbed and pre-absorbed cholesterol are preferentially secreted via apoB-independent and apoB-dependent pathways, respectively. In contrast to compartmentalization for secretion, these two metabolic pools are equally accessible for cellular esterification. The esterified cholesterol is mainly secreted by the apoB-dependent pathway, whereas both the pathways are involved in the secretion of free cholesterol. Thus, enterocytes transport exogenous cholesterol by several independently regulated pathways raising the possibility that targeting of apoB-independent pathways may result in selective inhibition of cholesterol transport without affecting triglyceride transport. 相似文献
108.
109.
Mukhopadhyay I Nazir A Mahmood K Saxena DK Das M Khanna SK Chowdhuri DK 《Cell biology and toxicology》2002,18(1):1-11
The effect of argemone oil on hsp70expression and tissue damage was investigated by studying β-galactosidase activity, Western blotting and hybridization, and
trypan blue staining in the larval tissues of transgenic Drosophila melanogaster(hsp70-lacZ)Bg
9. Different concentrations of argemone oil were mixed with food and third-instar larvae were allowed to feed on them for different
time intervals (2, 4, 24, and 48 h). Argemone oil was found to induce hsp70even in the lowest concentration of the adulterant while maximum tissue damage was observed in the higher two treatment groups.
Malpighian tubules and midgut tissue reflected maximum damage as evidenced by both high β-galactosidase activity and trypan
blue staining in these tissues. A prior temperature shock treatment to the larvae was enough to protect the larvae from argemone
oil-induced tissue damage as evidenced by little or no trypan blue staining. The present study suggests the cytotoxic potential
of argemone oil and further strengthens the evidence for the use of hsp70as a biomarker in risk assessment.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
110.