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CG Teo 《Oral diseases》2002,8(S2):88-90
Oral hairy leukoplakia (OHL) and Kaposi's sarcoma (KS) are commonly encountered in the HIV-infected patient. A unique feature of OHL is non-cytolytic high level of replication of Epstein–Barr virus (EBV) in the glossal epithelium. The expression of viral-encoded anti-apoptotic proteins concomitant to replicative proteins probably underlies this phenomenon. The question of whether OHL arises from activation of EBV latent in the tongue, or from superinfection by endogenous EBV shed via non-glossal sites or by exogenous EBV remains unresolved. Human herpesvirus 8 (HHV8) is now seen as necessary but not sufficient cause of KS. Expression of HHV8-encoded oncogenic proteins in endothelial cells probably explains the aberrant proliferation of these cells in KS lesions. Studies into why KS is so commonly observed at the palate in HIV-infected patients may provide important clues to its pathogenesis. 相似文献
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Transfection of human macrophages by lipoplexes via the combined use of transferrin and pH-sensitive peptides 总被引:10,自引:0,他引:10
Simões S Slepushkin V Pretzer E Dazin P Gaspar R Pedroso de Lima MC Düzgüneş N 《Journal of leukocyte biology》1999,65(2):270-279
The crucial function of macrophages in a variety of biological processes and pathologies render these cells important targets for gene therapeutic interventions. Commonly used synthetic gene delivery vectors have not been successful in transfecting these non-dividing cells. A combination strategy involving cationic liposomes to condense and carry DNA, transferrin to facilitate cellular uptake, and the pH-sensitive peptide GALA to promote endosome destabilization, resulted in significant expression of a luciferase gene. Transfection of macrophages was dependent on the degree of differentiation of the cells. The quaternary complexes of cationic liposomes, DNA, transferrin, and GALA exhibited a net negative charge, which may obviate a limitation of cationic synthetic vectors in vivo. The lack of cytotoxicity and the expected lack of immunogenicity of these complexes may render them useful for gene delivery to macrophages in vivo. 相似文献
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Arif JM; Gairola CG; Glauert HP; Kelloff GJ; Lubet RA; Gupta RC 《Carcinogenesis》1998,19(8):1515-1517
The present study investigated the effects of dietary oltipraz on cigarette
smoke-related lipophilic DNA adduct formation. Female Sprague- Dawley rats
were exposed daily to sidestream cigarette smoke in a whole- body exposure
chamber 6 h/day for 4 consecutive weeks. One group of rats was maintained
on control diet while another group received the same diet supplemented
with either a low (167 p.p.m.) or high (500 p.p.m.) dose of oltipraz,
starting 1 week prior to initiation of smoke exposure until the end of the
experiment. Analysis of lipophilic DNA adducts by the nuclease P1-mediated
32P-post-labeling showed up to five smoke-related adducts. Adduct no. 5
predominated in both the lung and the heart while adduct nos 3 and 2
predominated in the trachea and bladder, respectively. Quantitative
analysis revealed that the total adduct level was the highest in lungs
(270+/-68 adducts/10(10) nucleotides), followed by trachea (196+/-48
adducts/10(10) nucleotides), heart (141+/-22 adducts/10(10) nucleotides)
and bladder (85+/-16 adducts/10(10) nucleotides). High dose oltipraz
treatment reduced the adduct levels in lungs and bladder by >60%, while
the reduction in lungs in the low-dose group was approximately 35%. In
trachea, the effect of low and high dietary oltipraz on smoke DNA adduction
was equivocal, while smoke-related DNA adducts in the heart were minimally
inhibited by high-dose oltipraz. In a repeat experiment that employed a
3-fold lower dose of cigarette smoke, oltipraz (500 p.p.m.) was found to
inhibit the formation of DNA adducts in rat lungs and trachea by 80 and
65%, respectively. These data clearly demonstrate a high efficacy of
oltipraz in inhibiting the formation of cigarette smoke-induced DNA adducts
in the target tissues.
相似文献
8.
Mutation of the p53 tumor suppressor gene in spontaneously occurring osteosarcomas of the dog 总被引:8,自引:0,他引:8
Inactivation of the p53 tumor suppressor gene has been implicated in the
pathogenesis of numerous human cancers, including osteosarcomas.
Appendicular osteosarcomas of the dog appear to be a good model for their
human equivalent with regard to biologic behavior, epidemiology and
histopathology. We individually screened exons 5-8 of the p53 gene for
mutations in 15 canine appendicular osteosarcomas using 'Cold' SSCP to
compare the role of this gene in human and canine osteosarcoma
tumorigenesis. Seven of the tumors (47%) exhibited point mutations, with
one tumor possessing two mutations within different exons. Of these, seven
were missense mutations and the eighth was a 'silent' mutation potentially
affecting the exon 6-7 splicing region. Five of the missense mutations were
located in highly conserved regions IV and V, while another corresponded
with the highly conserved codon 220 mutational hotspot located outside the
conserved domains. The locations and types of mutations were nearly
identical to those reported in human cancer. These findings provide strong
evidence of the involvement of p53 mutations in the development of canine
appendicular osteosarcomas. Canine osteosarcomas appear to be a promising
model for their human equivalent on a clinical, pathologic, and molecular
level.
相似文献
9.
R W Foltin M W Fischman J J Pedroso G D Pearlson 《Pharmacology, biochemistry, and behavior》1987,28(4):459-464
Seven adult male volunteers residing on a research ward received intravenous cocaine and smoked marijuana, alone and in combination, during daily experimental sessions. Following the determination of baseline cardiovascular indexes, a one gram marijuana cigarette (0-2.7% delta 9-THC w/w) was smoked. Cocaine hydrochloride (0-32 mg) was administered intravenously 13 minutes after the start of marijuana smoking. Cocaine alone produced dose-dependent increases in heart rate, while both low and high THC blood levels produced a similar increase in heart rate. Both doses of cocaine increased mean arterial pressure (MAP) similarly, while THC alone produced blood level dependent increases in MAP. Combinations of cocaine and marijuana increased heart rate above levels seen with either drug alone, with increases plateauing at nearly 50 bpm for all dose-blood level combinations. Increases in mean arterial pressure following combinations of cocaine and marijuana were equivalent to those produced by cocaine alone. 相似文献
10.
本文对模式产地的山药Piper haneei Maxim, var, hancei Maxim,和腺鳞蒟P. kancei Maxim var. squamiglanduferum Fan var. nov.进行了原植物形态特征和花序轴、花序梗、茎、叶的显微特征以及化学成分的TLC及UV比较。挥发油的GC—MS研究共鉴定出38个成分,其中28个是胡椒属植物中首次报道的成分。结果证明了在福建长期以来被认为是山药的腺鳞蒟与模式产地的山药有较大差别,尤其是腺鳞蒟叶上表面有腺鳞,是迄今为止第1个发现具有腺鳞的胡椒属植物。据此把腺鳞蒟作为新变种从山药中分出。腺鳞药是福建南部海风藤主要来源之一。 相似文献