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11.
Successful cancer gene therapy depends on the development of non-toxic, efficient, tumor cell- specific systemic gene delivery systems. Our laboratory has developed a systemically administered, ligand–liposome complex that can effectively and preferentially deliver its therapeutic payload to both primary and metastatic tumors. To further improve the transfection efficiency of this targeting complex, a synthetic pH-sensitive histidylated oligolysine K[K(H)KKK]5-K(H)KKC (HoKC), designed to aid in endosomal escape and condensation of DNA, was included in the complex. The presence of HoKC increased the in vitro transfection efficiency over that of the original complex. Moreover, no increase in cytotoxicity was observed due to the presence of the HoKC peptide. In a DU145 human prostate cancer xenograft tumor model in athymic nude mice, inclusion of the HoKC peptide did not interfere with the tumor targeting specificity of the i.v. administered ligand/liposome/DNA complex. Most importantly, the level of transgene expression was significantly elevated in the tumors, but not in the normal tissue in those animals receiving the complex incorporating HoKC. The in vivo enhancement of transfection efficiency by this modified gene delivery vehicle could lead to a reduction in the number of administrations required for antitumor efficacy.  相似文献   
12.
Discovering lactic acid bacteria by genomics   总被引:25,自引:0,他引:25  
This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, nvironmental habitat, and its role in fermentation, bioprocessing, or probiotics. For those projects where genome sequence data were available by March 2002, summaries include a listing of key statistics and interesting genomic features. These efforts will revolutionize our molecular view of Gram–positive bacteria, as up to 15 genomes from the low GC content lactic acid bacteria are expected to be available in the public domain by the end of 2003. Our collective view of the lactic acid bacteria will be fundamentally changed as we rediscover the relationships and capabilities of these organisms through genomics.  相似文献   
13.
Serum interleukin-18 and nitric oxide activity in bladder carcinoma   总被引:3,自引:0,他引:3  
BACKGROUND: Both interleukin-18 and nitric oxide are multifunctional molecules that are involved in the different steps of carcinogenesis. METHODS: In the present study, we measured serum interleukin-18 and nitric oxide activity in 51 bladder cancer patients with different tumor stage and grade, and in 8 healthy controls. Serum nitrite-nitrate levels were measured as an index of nitric oxide generation. RESULTS: Serum interleukin-18 levels were significantly higher in bladder cancer patients when compared to the control subjects (p > 0.05). Serum interleukin-18 levels were found to be higher in patients with Ta stage than patients with T1 and T2, T3, T4 stages and in patients with grade 1 tumors than patients with grade 2 and grade 3 tumors, but this was not statistically significant (p > 0.05). There was no significant difference in serum nitrite + nitrate levels between bladder cancer patients and control subjects. CONCLUSIONS: Elevated serum interleukin-18 levels in bladder carcinoma patients may be a result of host defence mechanism against the growth and progression of bladder cancer cells.  相似文献   
14.
The morphology, anatomy and distribution of glandular trichomes on the aerial organs of Salvia argentea L. has been investigated. Two morphologically distinct types of glandular trichomes were determined. Capitate glandular trichomes forming a base 1–7 celled, a stalk 1–5 celled or no stalk and a head uni- or bicellular had various types. In capitate trichomes, the neck cell that has an important role especially for xeroformic plants, acting to prevent the backflow of secreted substance through the apoplast has been distinctively observed in the investigated species. The capitate trichomes were present abundantly on all aerial organs of S. argentea. Peltate glandular trichomes had a large secretory head forming 1–5, 8 central and 8–10, 12, 14 peripheral cells. Peltate trichomes are present on all aerial organs, except petiole, being the most abundant on calyx and corolla. Results were shown by tables and photographs.  相似文献   
15.

Background  

Polysomnography (PSG) is used to define physiological sleep and different physiological sleep stages, to assess sleep quality and diagnose many types of sleep disorders such as obstructive sleep apnea. However, PSG requires not only the connection of various sensors and electrodes to the subject but also spending the night in a bed that is different from the subject's own bed. This study is designed to investigate the feasibility of automatic classification of sleep stages and obstructive apneaic epochs using only the features derived from a single-lead electrocardiography (ECG) signal.  相似文献   
16.
Demirkan A  Melli M 《Lab animal》2007,36(2):39-41
Many studies require collection of metabolic wastes from laboratory animals, and oftentimes it is important that feces and urine be collected separately. The authors describe an easily assembled and inexpensive device that can be used to collect urine samples from rats without any invasive operations. The device affords reasonable separation of feces and urine.  相似文献   
17.
Ultrastructural changes in the kidneys of rats after acute cadmium exposure and the effects of exogenous metallothionein (MT) were studied by transmission electron microscopy. Thirty-six adult Wistar rats were divided into three groups. Cadmium chloride (CdCl2) (3.5 mg/kg/day) was injected subcutaneously in the first group. In the second group, 30 μmol/kg MT was administered in addition to CdCl2. Control rats received 0.5 ml subcutaneous saline solution. Four rats from each group were killed on days 1, 3, 5, and 7 after administration of the compounds. Kidney tissues were taken and fixed in 2.5% glutaraldehyde solution for electron microscopic observations. Tissue damage in kidney increased as time passed since the administration of CdCl2 in the first group. Degeneration in the proximal and distal tubules was observed. Increased apoptosis was seen in the proximal tubules epithelium, especially on day 7. Peritubular capillaries became dilated, there was degeneration of the endothelial cells, and the amount of intertubular collagen fibers was increased. On day 1, irregular microvilli in the proximal tubules, deepening of the basal striations, and myelin figures; on day 3, multiple vesicular mitochondria and regions of edema around tubules; on days 5 and 7, increased apoptotic cell in the proximal tubules and widened rough endoplasmic reticulum of the endothelial cells of glomerular capillaries were observed. We observed that the structural alterations that increased depending on the day of Cd administration decreased after exogenous MT administration, the dilation of the peritubular capillaries persisted, and there were degenerated proximal tubules. It was established that cadmium chloride was toxic for kidney cortex and caused structural damage. Exogenous MT partly prevents CdCl2-induced damage.  相似文献   
18.
Previous studies have revealed that chlorine participates in a complex biogeochemical cycle in soil, which suggests that the transport of chloride through catchments may also be influenced. The present study is based on field observations of organic carbon, chloride (Clin), and chlorinated organic carbon (Clorg) in precipitation, soil, and runoff over a 2-year period from a small, forested catchment in southeast Sweden. The study reveals that (1) the soil pool is dominated by Clorg, (2) the input via wet deposition and output of Clin via runoff is 30 times smaller than the total storage of chlorine (Clin + Clorg) in soil, and (3) the transport is dominated by Clin. The organic matter that entered the outlet of the catchment was more chlorinated in the autumn than during the rest of the year, and rain events taking place in low-flow periods had a greater influence on TOC, Clorg, and Clin than did rain events taking place in high-flow periods. The seasonal pattern in combination with the low-flow versus high-flow pattern and previous findings of increasing chlorine-to-carbon ratios with soil depth suggests that the chlorine-to-carbon ratio variation in the leached organic matter is due that water preferentially comes from deeper layers in low-flow conditions. This study provides well-founded estimates of Clorg and Clin storage and fluxes for the studied catchment; however, the processes underlying the observed seasonal Clorg variations and transportation processes need further study.  相似文献   
19.

Introduction  

Co-morbidity and mortality due to cardiovascular disease (CVD) are increased in patients with rheumatoid arthritis (RA). Most published studies in this field are retrospective or cross sectional. We investigated the presence of traditional and disease related risk factors for CVD at the onset of RA and during the first five years following diagnosis. We also evaluated their potential for predicting a new cardiovascular event (CVE) during the five-year follow-up period and the modulatory effect of pharmacological treatment.  相似文献   
20.
Within the framework of the present study we test whether climatic niche similarity can be identified in a monophyletic group of species inhabiting remarkably restricted ranges by pooling presence data of all species into a single concatenated data set and subsequently jackknifing single species. We expect that, when the jackknifed species differs markedly in its climatic niche from all other species, this approach will result in increased niche homogeneity, allowing assessments of niche divergence patterns. To test our novel jackknife approach, we developed species distribution models for all members of Lycian salamanders (genus Lyciasalamandra), native to Turkey and the adjacent Aegean islands using Maxent. Degrees of niche similarity among species were assessed using Schoener’s index. Significance of results was tested using null-models. The degree of niche similarity was generally high among all seven species, with only L. helverseni differing significantly from the others. Carstic lime stones providing specific microhabitat features may explain the high degree of niche similarity detected, since the variables with the highest explanative power in our models (i.e. mean temperature, and precipitation of the coldest quarter) corresponded well with salamander natural history observations, supporting the biologically plausibility of the results. We conclude that the jackknife approach presented here for the first time allows testing for niche similarity in species inhabiting restricted ranges and with few species records available. Our results strongly support the view that detailed natural history information and knowledge of microhabitats is crucial when assessing possible climate change impacts on species.  相似文献   
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