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181.
BACKGROUND: This study uses wrist actigrapy to assess the effects of 24-hr transdermal nicotine replacement on the sleep and daytime activity of smokers during smoking cessation. METHODS: Seventy-one subjects grouped as light (n = 23), moderate (n = 24), or heavy (n = 24) smokers were randomly assigned to placebo or 11, 22, or 44 mg/day doses of transdermal nicotine for 1 week of intensive inpatient treatment of nicotine dependence. Outpatient patch therapy continued for 7 weeks following the inpatient stay. Those initially on placebo were randomly assigned to 11 or 22 mg/day, and those initially on 44 mg/day were reduced to 22 mg/day at Week 4. RESULTS: There was a significant decrease in daytime wrist activity during patch therapy and the 1st week off patch therapy. These changes in daytime wrist activity were positively correlated with percentage of nicotine and cotinine replacement. No changes from baseline in sleep (sleep efficiency or wrist activity) were detected, nor were there differences in sleep among the four patch doses. CONCLUSIONS: Using wrist actigraphy, this study failed to show any disturbing effects of 24-hr high-dose nicotine replacement on sleep. Lower levels of nicotine replacement were associated with a decrease from baseline in daytime wrist activity.  相似文献   
182.
Resveratrol (3,4',5-trihydroxy-trans-stilbene), a phytoalexin found in grape skins, peanuts, and red wine, has been reported to exhibit a wide range of biological and pharmacological properties. It has been speculated that dietary resveratrol could be an explanation for the so-called 'French paradox' as it may act as an antioxidant, promote nitric oxide production, inhibit platelet aggregation, and increase high-density lipoprotein cholesterol, and thereby serve as a cardioprotective agent. Recently, it has been demonstrated that resveratrol can function as a cancer chemopreventive agent, and there has been a great deal of experimental effort directed toward defining this effect. It has been shown that resveratrol and some of its analogs interfere with signal transduction pathways, modulate cell cycle-regulating proteins, and is a potent inducer of apoptosis in multiple carcinoma cell lines. This review summarizes the recent advances that have provided new insights into the molecular mechanisms underlying the promising properties of resveratrol.  相似文献   
183.
The erucoyl-CoA specific sn-1-acylglycerol-3-phosphate acyltransferase (LPAAT) of Limnanthes douglasii was functionally expressed in developing seeds of differing high-erucic acid rapeseed genotypes, namely resynthesized lines and cultivars. Lipid analysis revealed that seed oil of transgenic plants in contrast to that of control plants contained trierucoylglycerol as well as a molecular species with two erucoyl groups and one eicosenoyl group. The proportion of trierucoylglycerol was distinctly higher in the seeds from transgenic resynthesized plants than in those from transgenic cultivars. In pooled seed oil fractions, up to 9% trierucoylglycerol (trierucin) was determined and the fatty acid composition at the sn-2 position was found to consist of more than 40% erucic acid. Since the pooled seeds were segregating for the presence of the L. douglasii gene, the analysis of single seeds gave even higher levels of up to 13% trierucin.  相似文献   
184.
Biochemical and Molecular Biological Approaches for Changing the Fatty Acid Composition of Rape Seed Oil For the technical usability of rape seed oil and uniform esterification of all three positions of the glycerol backbone with erucic acid is desired, which is not found in the varieties examined so far. Our enzymatic investigations revealed that this is especially due to the characteristics of the acyltransferase catalyzing the acylation of the C-2 position of the glycerol backbone. This enzyme is unable to utilize erucic acid as a substrate. The corresponding enzyme activity of Limnanthes douglasii, however, posseses the ability to incorporate erucic acid. To transfer this property to rape seed the corresponding gene has to be isolated. A gene isolation using antibodies or oligonucleotides requires the purification of the protein encoded by the gene, which up to now has failed. In parallel to our further efforts to purify the protein we have started to establish alternative methods of gene isolation based on the functional expression of cDNAs in microorganisms.  相似文献   
185.
The Ca2+/calmodulin dependent protein kinase II (CaM kinase II) is thought to play an important part in glucose-stimulated insulin secretion. To determine which of the known subtypes (alpha, beta, gamma, delta) occur in insulin-secreting cells, we amplified all types of CaM kinase II by RT-PCR and found the beta3-, gamma-, delta2- and delta6-subtypes in RINm5F insulinoma cells. None of the other 8 delta-subtypes was present. Antibodies generated against the bacterially expressed association domain of the delta2-subtype recognized the recombinant gamma and delta-subtypes. In INS-1 and RINm5F cells, as well as freshly isolated rat islets, only a 55-kDa protein corresponding in size to the delta2-subtype expressed in NIH3T3 fibroblasts was detected. The delta2-subtype therefore appears to represent the predominant subtype of CaM kinase II present in insulin secreting cells. The enzyme was primarily associated with cytoskeletal structures, and very little was present in the soluble compartment or detergent soluble fraction in INS-1- or RINm5F-cells. An analysis of its subcellular distribution was performed by sucrose and Nycodenz density gradient fractionation of INS-1 cells and detection of CaM kinase II delta by immune blots. The enzyme codistributed with insulin used as a marker for secretory granules but not with the lighter synaptic-like microvesicles detected with an antibody against synaptophysin, plasma membranes (syntaxin 1), lysosomes (arylsulfatase), or mitochondria (cytochrome c oxidase). CaM kinase II delta2 thus is identified as the subtype associated with insulin secretory granules and is likely to be involved in insulin secretion.  相似文献   
186.
Nineteen benign [World Health Organization (WHO) grade I; MI], 21 atypical (WHO grade II; MII), and 19 anaplastic (WHO grade III; MIII) sporadic meningiomas were screened for chromosomal imbalances by comparative genomic hybridization (CGH). These data were supplemented by molecular genetic analyses of selected chromosomal regions and genes. With increasing malignancy grade, a marked accumulation of genomic aberrations was observed; i.e., the numbers (mean +/- SEM) of total alterations detected per tumor were 2.9 +/- 0.7 for MI, 9.2 +/- 1.2 for MII, and 13.3 +/- 1.9 for MIII. The most frequent alteration detected in MI was loss on 22q (58%). In MII, aberrations most commonly identified were losses on 1p (76%), 22q (71%), 14q (43%), 18q (43%), 10 (38%), and 6q (33%), as well as gains on 20q (48%), 12q (43%), 15q (43%), 1q (33%), 9q (33%), and 17q (33%). In MIII, most of these alterations were found at similar frequencies. However, an increase in losses on 6q (53%), 10 (68%), and 14q (63%) was observed. In addition, 32% of MIII demonstrated loss on 9p. Homozygous deletions in the CDKN2A gene at 9p21 were found in 4 of 16 MIII (25%). Highly amplified DNA sequences were mapped to 12q13-q15 by CGH in 1 MII. Southern blot analysis of this tumor revealed amplification of CDK4 and MDM2. By CGH, DNA sequences from 17q were found to be amplified in 1 MII and 8 MIII, involving 17q23 in all cases. Despite the high frequency of chromosomal aberrations in the MII and MIII investigated, none of these tumors showed mutations in exons 5-8 of the TP53 gene. On the basis of the most common aberrations identified in the various malignancy grades, a model for the genomic alterations associated with meningioma progression is proposed.  相似文献   
187.
Advances in satellite technology in the area of very small aperture terminals (VSATs) offer economical data and voice services for corporate networks and rural applications. The authors describe VSAT application and technology with emphasis on analyzing the issues of quality after the sale. The quality and maintenance requirements of the VSAT networks in operation are defined. The reliability, maintainability, and availability calculations for VSAT networks with different topologies are evaluated. Results show that both star and point-to-point VSAT networks are capable of meeting higher availability standards  相似文献   
188.
189.
We have investigated the mechanism of light-induced band-structure modifications to be employed in light-activated switching devices. This mechanism has been studied in a specially designed modulation doped GaAs/AlxGa1−xAs heterostructure by means of photoluminescence spectroscopy at low temperatures. It is related to the build-up of photogenerated carriers in the heterostructure, thereby changing the band structure. We show that this mechanism can be employed in a light-activated all-optical switch or a light-activated all-optical modulator with an expected contrast ratio of 27:1.  相似文献   
190.
Three cases of chronic infection with Borrelia burgdorferi are described. The patients presented with nodular or discoid fibrosis, partly in conjunction with acrodermatitis chronica atrophicans (ACA). Juxta-articular fibrotic nodules may develop within a few months of the onset of ACA. Nodular, discoid morphoea-like, and widespread cutaneous fibroses in chronic Borrelia infection may be provoked by trauma, surgery or electromagnetic radiation. They respond well to antibiotic therapy. These lesions offer an in vivo model for studying the evolution of immunologically induced fibrosis.  相似文献   
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