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排序方式: 共有347条查询结果,搜索用时 15 毫秒
91.
Current medical thinking supports early initiation of aggressive approaches to the management of perinatally acquired HIV infection. Biological mothers, however, may not endorse this way of managing their child's condition. For this study, grounded theory methods were used to conduct secondary analysis of eight semi-structured in-depth interviews with parents of children with perinatally acquired HIV. Biological mothers' perspectives on their children's treatment for perinatally acquired HIV infection, the strategies they used to manage their children's treatment and sociocultural influences on mothers' beliefs and actions are explored and described. Creation of a framework that may be useful for future research and recommendations for clinical practice are offered. 相似文献
92.
Carcinogenic polycyclic aromatic hydrocarbons increase intracellular Ca2+ and cell proliferation in primary human mammary epithelial cells 总被引:1,自引:1,他引:1
Previous studies have shown that polycyclic aromatic hydrocarbons (PAHs)
mobilize intracellular Ca2+ in human T cells by inositol
trisphosphate-dependent mechanisms resulting from activation of
phospholipase C-gamma by SRC-related protein tyrosine kinases, thereby
mimicking antigen-receptor activation. Ca2+ appears to play an important
second messenger role in growth factor control of cell proliferation in
human mammary epithelial cells (HMEC), such as the epidermal growth factor
receptor pathway. The purpose of the present studies was to determine if
PAHs are able to increase intracellular Ca2+ in primary cultures of HMEC
and increase cell proliferation. Two carcinogenic and two non-carcinogenic
PAHs were tested for their ability to increase intracellular Ca2+ in HMEC.
The carcinogenic PAHs dimethylbenz[a]anthracene (DMBA) and benzo[a] pyrene
(BaP) were able to cause Ca2+ elevation in HMEC at early time points (2 h)
and caused sustained alterations in Ca2+ homeostasis (18 h). DMBA showed
maximal effects at early time points (2 h), while BaP showed maximal
effects on sustained Ca2+ (18 h). 2,3,7,8-Tetrachlorodibenzo-p-dioxin
(TCDD), a potent dioxin and tumor promoter, produced maximal Ca2+ elevation
at 2 h, with a return to near baseline levels by 6 h. The non-carcinogenic
PAHs benzo[e]pyrene and anthracene did not significantly alter
intracellular Ca2+ at any time point. alpha-Naphthoflavone significantly
reduced the Ca2+ response induced by BaP treatment, but not by DMBA or
TCDD, suggesting that P450 1A or 1B metabolism of BaP may be important in
the sustained Ca2+ elevating response. In evaluating the effects of BaP on
HMEC proliferation, BaP was found to increase the number of cells recovered
after 4 days in culture in the absence or presence of various
concentrations of epidermal growth factor. These studies provide initial
evidence that Ca2+ signaling may be associated with mitogenesis in HMEC,
which may play a role in tumor promotion and progression produced by PAHs.
相似文献
93.
Three cases of asymptomatic intussusception in adults are reported, discovered incidentally during a CT scan of the abdomen. It is being increasingly observed in adults, possibly aided by the reformatting capabilities of the new multislice CT scanners. It has been documented in children where it is considered to be transient and of no clinical significance. 相似文献
94.
Roessler E; Belloni E; Gaudenz K; Vargas F; Scherer SW; Tsui LC; Muenke M 《Human molecular genetics》1997,6(11):1847-1853
Holoprosencephaly (HPE) is the most common brain anomaly in humans,
involving abnormal formation and septation of the developing central
nervous system. Among the heterogeneous causes of HPE, mutations in the
Sonic Hedgehog (SHH) gene have been shown to result in an autosomal
dominant form of the disorder. Here we describe a total of five different
mutations in the processing domain encoded by exon 3 of SHH in familial and
sporadic HPE. This is the first instance in humans where SHH mutations in
the domain responsible for autocatalytic cleavage and cholesterol
modification of the N-terminal signaling domain of the protein have been
observed.
相似文献
95.
96.
抗肿瘤药物研究Ⅰ:去甲斑蝥素氨基酸衍生物的合成与抗癌活性 总被引:1,自引:0,他引:1
In order to search for new compounds with higher anti-cancer activities and lower toxicities, 19 amino acid derivatives of norcantharidin, of which 16 are unknown compounds, were designed and synthesized. Preliminary screening results revealed that 2-(syn-exo-7-oxabicyclo [2. 2. 1] heptane-2, 3-dicarboxylic imido)-N-phenyl glutaramic acid exhibited a fairly apparent inhibitory activity against human-hepatoma cells in vitro (inhibitory rate 39.4% at 0.025 μtmol/ml). 相似文献
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