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排序方式: 共有786条查询结果,搜索用时 15 毫秒
1.
Sequence complexity and diversity of polyadenylated RNA molecules transcribed in human myeloid cells
2.
3.
The distribution of thiamine, thiamine phosphoesters, and the thiamine pyrophosphate synthetizing [thiamine-pyrophosphokinase (TPKase)] as well as hydrolyzing [thiamine pyrophosphatase (TPPase) and thiamine monophosphatase (TMPase)] enzymes was determined in neuronal and glial enriched fractions prepared from rat brain. Nucleoside diphosphatases [inosine diphosphatase (IDPase) and uridine diphosphatase (UDPase)] and nucleoside monophosphatases [uridine monophosphatase (UMPase) and inosine monophosphatase (IMPase)] were also determined. Thiamine and thiamine mono- and pyrophosphate were present in neuronal enriched fractions at concentrations 2.8, 3.6, and 4.6 times higher than in glial fractions. TMPase was found only in glial enriched fractions, whereas the levels of TPKase, UMPase, IMPase, IDPase, UDPase, and TPPase were 2.0-, 2.2-, 1.3-, 2.8-, 3.7-, and 20.8-fold higher in neuronal than in glial fractions. 相似文献
4.
Novel eicosanoid biosynthetic pathways and receptors are reviewed as potential targets for pharmacological intervention. In addition to the cyclooxygenase and lipoxygenase pathways of arachidonate metabolism, a cytochrome P450-dependent monooxygenase has been identified in corneal and renal epithelial cells. Elucidation of the enzymatic pathways of thromboxane (TX) disposition and development of analytical techniques for measuring urinary metabolites have allowed a reliable assessment of TXA2 biosynthesis in health and disease, and provide a rationale for the combined use of TX-synthase inhibitors and TXA2-receptor antagonists in the setting of platelet activation. Recent evidence for a transcellular metabolism of neutrophil-derived leukotriene (LT) A4 by other human blood cells might link platelet and neutrophil activation to the occurrence of vasospastic phenomena. Prostacyclin (PG1(2)), PGE2, PGD2, TXA2/PGH2, and sulfidopeptide-LT receptors are being characterized in terms of distribution, signal-transduction mechanisms, and agonist-mediated regulation. Development of relatively selective agonists and antagonists of these receptors is providing novel therapeutic strategies for several human diseases. 相似文献
5.
Roberto F. Nicosia Antonio Ottinetti 《In vitro cellular & developmental biology. Plant》1990,26(2):119-128
Summary Rings of rat aorta cultured in Matrigel, a reconstituted gel composed of basement membrane molecules, gave rise to three-dimensional
networks composed of solid cellular cords and occasional microvessels with slitlike lumina. Immunohistochemical and ultrastructural
studies showed that the solid cords were composed of endothelial sprouts surrounded by nonendothelial mesenchymal cells. The
angiogenic response of the aortic rings in Matrigel was compared to that obtained in interstitial collagen, fibrin, or plasma
clot. Morphometric analysis demonstrated that the mean luminal area of the microvascular sprouts and channels was significantly
smaller in Matrigel than in collagen, fibrin, or plasma clot. The percentage of patent microvessels in Matrigel was also markedly
reduced. Autoradiographic studies of3H-thymidine-labeled cultures showed reduced DNA synthesis by developing microvessels in Matrigel. The overall number of solid
endothelial cords and microvessels was lower in Matrigel than in fibrin or plasma clot. A mixed cell population isolated from
Matrigel cultures formed a monolayer in collagen or fibrin-coated dishes but rapidly reorganized into a polygonal network
when plated on Matrigel. The observation that gels composed of basement membrane molecules modulate the canalization, proliferation,
and organization into networks of vasoformative endothelial cells in three-dimensional cultures supports the hypothesis that
the basement membrane is a potent regulator of microvascular growth and morphogenesis.
This work was supported by grants from the W. W. Smith Charitable Trust and grants CA14137 and HL43392 from the National Institutes
of Health, Bethesda, MD. 相似文献
6.
Lucia Rosaria De Vitis Andrea Tedde Francesca Vitelli Franco Ammannati Pasquale Mennonna Umberto Bigozzi Enrico Montali Laura Papi 《Human genetics》1996,97(5):632-637
Meningiomas are benign tumors of the central nervous system. They are usually sporadic but can also occur associated with the neurofibromatosis type 2 (NF2) syndrome. The gene responsible for NF2, recently isolated from chromosome 22, encodes a membrane-organizing protein that shows high sequence homology to a protein family thought to link the cytoskeleton with membrane proteins. Mutations of the NF2 gene have been described in sporadic meningiomas, exclusively in tumors that show loss of heterozygosity (LOH) of 22q. These preliminary results indicate that the NF2 gene is involved in the pathogenesis of at least a subset of meningiomas, where it does indeed behave as a tumor suppressor gene. In order to characterize better the role of the NF2 gene in the genesis of meningiomas we have examined the entire coding sequence of the gene in 125 meningiomas by single-strand conformational polymorphism analysis; furthermore, LOH analysis for markers of 22q has been carried out. Inactivating mutations were identified in 30% of our samples, all of which also showed LOH of 22q. The majority of mutations identified were frameshifts and nonsense mutations, which are predicted to produce a truncated or non-functional protein. We also found two missense and three in-frame deletions that may pinpoint specific regions of the protein critical to its function. Furthermore, the distribution of mutations throughout the gene, suggested that exons 2, 3, 5, 11 and 13 are more frequently involved. Our results reconfirm the importance of the NF2 gene in the pathogenesis of meningiomas and also suggest that there may be a nonrandom clustering of mutations throughout the gene. 相似文献
7.
A preliminary report on the use of transfer factor for treating stage D3 hormone-unresponsive metastatic prostate cancer 总被引:4,自引:0,他引:4
Dr. Giancarlo Pizza Caterina De Vinci Diego Cuzzocrea Domenico Menniti Ernesto Aiello Paolo Maver Giuseppe Corrado Piero Romagnoli Ennio Dragoni Giuseppe LoConte Umberto Riolo Aldopaolo Palareti Paolo Zucchelli Vittorio Fornarola Dimitri Viza 《Biotherapy》1996,9(1-3):123-132
As conventional treatments are unsuccessful, the survival rate of stage D3 prostate cancer patients is poor. Reports have
suggested the existence of humoral and cell-mediated immunity (CMI) against prostate cancer tumour-associated antigens (TAA).
These observations prompted us to treat stage D3 prostate cancer patients with an in vitro produced transfer factor (TF) able
to transfer, in vitro and in vivo, CMI against bladder and prostate TAA. Fifty patients entered this study and received one
intramuscular injection of 2–5 units of specific TF monthly. Follow-up, ranging from 1 to 9 years, showed that complete remission
was achieved in 2 patients, partial remission in 6, and no progression of metastatic disease in 14. The median survival was
126 weeks, higher than the survival rates reported in the literature for patients of the same stage. 相似文献
8.
Gloria Giacomini Santo V. Nicosia Beatriz O. Saunders Caroline Fultz X. Sun Valerio M. Jasonni 《In vitro cellular & developmental biology. Animal》1995,31(4):300-309
Summary The ovarian mesothelium (OM) represents the tissue of origin of ovarian epithelial cancer. To gain insight into the regulation
of this tissue, OM organoids and submesothelial ovarian stromal cells (SC) were isolated from New Zealand White rabbits by
a stepwise tissue dispersal technique, while granulosa cells (GC) were aspirated from mature follicles (14±4 groups/animal).
OM and SC dispersal were sequentially accomplished by: a) 1-h incubation in collagenase type I (300 U/ml), gentle scraping
of the ovarian surface, and 1 g sedimentation of OM organoids (equivalent to 0.93±0.40 × 106 cells/animal) on 5% bovine serum albumin (BSA); b) 2-h incubation in pronase-collagenase (0.5%–300 U/ml) under periodical
resuspension and gentle scraping of SC (1.40±0.25 × 106/animal) from OM-denuded ovaries. After a week-long in vitro expansion, OM cells (OMC) were cultured alone and with SC or
GC within monocameral vessels or bicameral transfilter vessels in serumless, fibronectinrich (4μg/ml) HL-1 medium. After 7
d of contact cell-cell interaction, cytokeratin-positive OMC became surrounded by fibroblastoid, vimentin-positive SC or by
cytokeratin and vimentin-weakly positive GC. Filter-bound OMC humorally interacting with underlying SC or GC displayed a biphasic,
epithelioid and spindle, morphology with universal cytokeratin expression. Bromo-2′-deoxyuridine (BrdU) immunoperoxidase revealed
mean cell proliferation indices of 14.88% for OMC cultured alone, 11.21% and 19.39% for OMC cultured with GC or SC in monocameral
dishes, and 15.25% or 22.47% for OMC cultured in bicameral vessels over GC or SC, respectively. This model provides an experimental
tool for investigating the unexplored role of stromal-mesothelial interaction in OM pathobiology. 相似文献
9.
Umberto Belluco Roberta Bertani Rino A. Michelin Mirto Mozzon Franco Benetollo Gabriella Bombieri Robert J. Angelici 《Inorganica chimica acta》1995,240(1-2):567-574
The chloro complexes trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4, react with 1-alkynes HC---C---R in the presence of NEt3 to afford the corresponding acetylide derivatives trans-[Pt(Me) (C---C---R) (PPh3)2] (R = p-tolyl (1), Ph (2), C(CH3)3 (3)). These complexes, with the exception of the t-butylacetylide complex, react with the chloroalcohols HO(CH2)nCl (n = 2, 3) in the presence of 1 equiv. of HBF4 to afford the alkyl(chloroalkoxy)carbene complexes trans-[Pt(Me) {C[O(CH2)nCl](CH2R) } (PPh3)2][BF4] (R = p-tolyl, N = 2 (4), N = 3 (5); R=Ph, N = 2 (6)). A similar reaction of the bis(acetylide) complex trans-[Pt(C---C---Ph)2(PMe2Ph)2] with 2 equiv. HBF4 and 3-chloro-1-propanol affords trans-[Pt(C---CPh) {C(OCH2CH2CH2Cl)(CH2Ph) } (PMe2Ph)2][BF4] (7). T alkyl(chloroalkoxy)-carbene complex trans-[Pt(Me) {C(OCH2CH2Cl)(CH2Ph) } (PPh3)2][BF4] (8) is formed by reaction of trans-[Pt(Me)(Cl)(PPh3)2], after treatment with AgBF4 in HOCH2CH2Cl, with phenylacetylene in the presence of 1 equiv. of n-BuLi. The reaction of the dimer [Pt(Cl)(μ-Cl)(PMe2Ph)]2 with p-tolylacetylene and 3-chloro-1-propanol yields cis-[PtCl2{C(OCH2CH2CH2Cl)(CH2C6H4-p-Me}(PMe2Ph)] (9). The X-ray molecular structure of (8) has been determined. It crystallizes in the orthorhombic system, space group Pna21, with a = 11.785(2), B = 29.418(4), C = 15.409(3) Å, V = 4889(1) Å3 and Z = 4. The carbene ligand is perpendicular to the Pt(II) coordination plane; the PtC(carbene) bond distance is 2.01(1) Å and the short C(carbene)-O bond distance of 1.30(1) Å suggests extensive electronic delocalization within the Pt---C(carbene)---O moietry. 相似文献
10.
VIP stimulates adenylate cyclase activity of male and female rat anterior pituitaries and human prolactinomas, while dopamine inhibits the enzyme activity of female rat pituitaries and prolactinomas. A dopamine inhibited cyclase can be detected also in male rats provided the enzyme activity is increased by VIP. The analysis of the dose-response curves for one agent (VIP or dopamine) in the absence or in the presence of the other indicates that the two agents exhibit a different pattern of interaction in the different systems. In fact, in female rat pituitaries and in human prolactinomas, the curves for dopamine±VIP and for VIP±dopamine were parallel, indicating that the two agents exherted their effects independently from one another. On the contrary, in male rat pituitaries, the curves were definitively non parallel, that is, the inhibitory effect of dopamine was greatly amplified by VIP. In no case was the apparent affinity (EC50) of one agent modified by the presence of the other. It is concluded that two different modes of interaction between stimulatory and inhibitory neurohormones might exist at the level of adenylate cyclase from anterior pituitary cells. 相似文献