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排序方式: 共有118条查询结果,搜索用时 15 毫秒
1.
Linkage analysis was performed in a family with nonspecific X-linked mental retardation (MRX). Affected individuals had no clinical characteristics other than mental retardation. Linkage was detected to the marker loci DXS477, DXS465, DXS52, DXS15 and F8C with maximum lod scores of 1.70, 1.32, 2.52, 1.70, and 1.09, respectively ( = 0.0). The results strongly indicate that the gene for mental retardation in the family studied maps close to DXS52. 相似文献
2.
In the Baltic Sea area, the cladoceran Daphnia magna is commonly found in brackish water rockpools and it has been suggested that salinity is one of the niche dimensions that affects the distribution of the species. The salinity tolerance of D. magna was studied both in physiological and life history experiments. The experimental salinities were freshwater, 4S and 8S. The highest respiration and ammonium excretion rates were measured in the freshwater treatment with decreasing respiration and ammonium excretion rates at higher salinities. The lowest O/N ratio (oxygen consumption to ammonium excretion), describing the metabolic status of an organism, was obtained at 8S, although the only significant differences were detected when comparing to 4S treatments. Individual growth rate, reproductive output and population growth rate were highest at 4S. At 8S growth and reproduction were reduced as compared to freshwater and 4S. The life history parameters in the performed experiments indicated higher fitness (expressed as r) as well as more favourable conditions for growth and reproduction at 4S, whereas the O/N ratio was more difficult to interpret and, in this case, gave a less clear picture of the salinity influence. 相似文献
3.
S. M. Fortney V. A. Koivisto P. Felig E. R. Nadel 《The Yale journal of biology and medicine》1981,54(2):101-109
Because diabetics are prone to the development of neuropathy and microvascular disease, abnormalities of cardiovascular reactivity and capillary permeability in response to acute exercise and/or an increase in environmental temperature might presage the development of clinically overt complications. In the present study insulin-dependent diabetics without evidence of microangiopathy or neuropathy and controls matched for the same level of physical fitness performed cycle ergometer exercise for 20 minutes at 65 percent VO2 max in a temperature maintained at 35 percent C. Ther rise in heart rate (82-85 beats min-1), the fall in plasma volume (11-13 percent), and the increase in total serum proteins (13-16 percent) induced by exercise were the same in the two groups. Furthermore, comparable increments in skin blood flow (two- to threefold) and in core and skin temperatures were observed. The relationship between increases in body core temperature and increases in skin blood flow and the vasodilatory threshold (37.0 percent C) were also the same in the diabetics and controls. 相似文献
4.
Lyzel S. Elias-Sonnenschein Seppo Helisalmi Teemu Natunen Anette Hall Teemu Paajanen Sanna-Kaisa Herukka Marjo Laitinen Anne M. Remes Anne M. Koivisto Kari M. Mattila Terho Lehtim?ki Frans R. J. Verhey Pieter Jelle Visser Hilkka Soininen Mikko Hiltunen 《PloS one》2013,8(4)
Objectives
To understand the relation between risk genes for Alzheimer’s disease (AD) and their influence on biomarkers for AD, we examined the association of AD in the Finnish cohort with single nucleotide polymorphisms (SNPs) from top AlzGene loci, genome-wide association studies (GWAS), and candidate gene studies; and tested the correlation between these SNPs and AD markers Aβ1–42, total tau (t-tau), and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF).Methods
We tested 25 SNPs for genetic association with clinical AD in our cohort comprised of 890 AD patients and 701-age matched healthy controls using logistic regression. For the correlational study with biomarkers, we tested 36 SNPs in a subset of 222 AD patients with available CSF using mixed models. Statistical analyses were adjusted for age, gender and APOE status. False discovery rate for multiple testing was applied. All participants were from academic hospital and research institutions in Finland.Results
APOE-ε4, CLU rs11136000, and MS4A4A rs2304933 correlated with significantly decreased Aβ1–42 (corrected p<0.05). At an uncorrected p<0.05, PPP3R1 rs1868402 and MAPT rs2435211 were related with increased t-tau; while SORL1 rs73595277 and MAPT rs16940758, with increased p-tau. Only TOMM40 rs2075650 showed association with clinical AD after adjusting for APOE-ε4 (p = 0.007), but not after multiple test correction (p>0.05).Conclusions
We provide evidence that APOE-ε4, CLU and MS4A4A, which have been identified in GWAS to be associated with AD, also significantly reduced CSF Aβ1–42 in AD. None of the other AlzGene and GWAS loci showed significant effects on CSF tau. The effects of other SNPs on CSF biomarkers and clinical AD diagnosis did not reach statistical significance. Our findings suggest that APOE-ε4, CLU and MS4A4A influence both AD risk and CSF Aβ1–42. 相似文献5.
Koivisto L Larjava K Häkkinen L Uitto VJ Heino J Larjava H 《Cell adhesion and communication》1999,7(3):245-257
Collaborative role of various fibronectin-binding integrins (alpha5beta1, alphavbeta1 and alphavbeta6) as mediators of cell adhesion and migration on fibronectin was studied using cultured HaCaT keratinocytes. This cell line spontaneously expressed all three fibronectin-binding integrins. In addition, the expression of alphavbeta6 integrin was strongly and specifically upregulated by transforming growth factor-beta1 (TGFbeta1) whereas the amount of other integrins remained practically unchanged on the cell surface. Adhesion, spreading and motility of HaCaT keratinocytes on fibronectin were promoted by TGFbeta1. Based on antibody blocking experiments, both untreated and TGFbeta1-treated HaCaT cells used alphavbeta6 integrin as their main fibronectin receptor for cell spreading. In contrast to TGFbeta1-treated cells, the untreated cells also needed alpha5beta1 integrin for maximal cell spreading on fibronectin. Combinations of antibodies blocking both of these receptors totally prevented spreading of both untreated and TGFbeta1-treated cells. Haptotactic motility of individual HaCaT cells through fibronectin-coated membranes was again mainly dependent on alphavbeta6 integrin, while alphavbeta1 and alpha5beta1 integrins played a lesser role both in untreated and TGFbeta1-treated HaCaT cells. However, unlike haptotaxis, lateral migration of HaCaT cell sheet was mainly mediated by beta1 integrins, and alphavbeta6 integrin showed a minor role. The migration process appeared to involve a number of beta1 integrins that could adaptively replace each other when blocking antibodies were present. Thus, keratinocytes appear to use different fibronectin receptors for different functions, such as cell spreading, haptotaxis and lateral migration. The cells can also adapt to a situation where one receptor is unfunctional by switching to another receptor of the same ligand. 相似文献
6.
Ylioja S Pertovaara A Koivisto J Korvenoja A Artchakov D Carlson S 《Somatosensory & motor research》2004,21(1):3-7
Somatosensory point localization is a clinical test evaluating spatial accuracy of the somatosensory system. Possible effects of the interstimulus interval (ISI) on point localization threshold have not been previously examined. In the present set of experiments the effect of time delay on somatosensory point localization was studied using ISIs of 1, 3, 5, 7, and 9 s, and applying a newly developed computer-controlled application method of a Semmes-Weinstein monofilament. It was found that the point localization threshold was not significantly affected by the ISI length. However, the response time was shorter and response accuracy better at the shorter (1 and 3 s) than at the longer (5, 7, and 9 s) ISIs, suggesting a change in the mechanism underlying point localization decision criteria in ISIs longer than 3 s. 相似文献
7.
Effects of electromagnetic field emitted by cellular phones on the EEG during an auditory memory task: a double blind replication study 总被引:5,自引:0,他引:5
Krause CM Haarala C Sillanmäki L Koivisto M Alanko K Revonsuo A Laine M Hämäläinen H 《Bioelectromagnetics》2004,25(1):33-40
The effects of electromagnetic fields (EMF) emitted by cellular phones on the event related desynchronization/synchronization (ERD/ERS) of the 4-6, 6-8, 8-10, and 10-12 Hz electroencephalogram (EEG) frequency bands were studied in 24 normal subjects performing an auditory memory task. This study was a systematic replication of our previous work. In the present double blind study, all subjects performed the memory task both with and without exposure to a digital 902 MHz field in a counterbalanced order. We were not able to replicate the findings from our earlier study. All eight of the significant changes in our earlier study were not significant in the present double blind replication. Also, the effect of EMF on the number of incorrect answers in the memory task was inconsistent. We previously reported no significant effect of EMF exposure on the number of incorrect answers in the memory task, but a significant increase in errors was observed in the present study. We conclude that EMF effects on the EEG and on the performance on memory tasks may be variable and not easily replicable for unknown reasons. 相似文献
8.
FOXL2 and BPES: mutational hotspots,phenotypic variability,and revision of the genotype-phenotype correlation 总被引:15,自引:0,他引:15
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9.
Hypersensitivity symptoms associated with exposure to cellular telephones: no causal link 总被引:5,自引:0,他引:5
The hypothesis that there exist hypersensitive persons who perceive subjective symptoms from radiofrequency (RF) fields emitted by hand held mobile phones (cellular phones) was tested using double blind provocation experiments. We also tested whether sensitive subjects are able to determine whether the phone is on or off by sensing RF fields. The study group consisted of 20 volunteers (13 women and 7 men) who reported themselves as being sensitive to cellular phones. The RF exposure sources were one analogue NMT phone (900 MHz) and two digital GSM phones (900 and 1800 MHz). The duration of a test session was 30 min, and three or four sessions were performed in random order for each subject during 1 day. The subjects were asked to report symptoms or sensations as soon as they perceived any abnormal feelings. In addition, the subjects' blood pressure, heart rate, and breathing frequency were monitored every 5 min. The results of the study indicated that various symptoms were reported, and most of them appeared in the head region. However, the number of reported symptoms was higher during sham exposure than during real exposure conditions. In addition, none of the test persons could distinguish real RF exposure from sham exposure. Hence, we conclude that adverse subjective symptoms or sensations, though unquestionably perceived by the test subjects, were not produced by cellular phones. 相似文献
10.
Androgen receptor CAG polymorphism and prostate cancer risk 总被引:4,自引:0,他引:4
Mononen N Ikonen T Autio V Rökman A Matikainen MP Tammela TL Kallioniemi OP Koivisto PA Schleutker J 《Human genetics》2002,111(2):166-171
Recent studies have suggested that polymorphisms of the androgen receptor gene ( AR) may influence the risk of prostate cancer (PC) development and progression. Here, we analyzed the length of the CAG repeat of the AR gene in 1363 individuals, including patients with PC, benign prostate hyperplasia (BPH), and population controls. There was a tendency for short CAG repeats to be associated with PC. The Odds Ratio (OR) for PC was 1.47 ( P=0.05) when individuals with short CAG repeats (=18) were compared with those having long repeats (>18). CAG repeat length was not significantly associated with family history, disease stage, grade, age at diagnosis, prostate-specific antigen (PSA) level at diagnosis, or prognosis of the patients. Unexpectedly, short CAG repeats were significantly less common in patients with BPH compared with controls (OR=0.47, P=0.03). Our results suggest that the CAG polymorphism of the AR gene is unlikely to have a major role in the development or progression of PC in the Finnish population. The association of CAG repeats with the risk of BPH warrants further study. 相似文献