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排序方式: 共有6180条查询结果,搜索用时 15 毫秒
31.
Niels Jrgensen Jrn Müller Aleksander Giwercman Jakob Visfeldt Henrik Mller Niels E. Skakkebk 《The Journal of pathology》1995,176(3):269-278
The origin of testicular germ cell tumours occurring during childhood is poorly understood. In adults, the classical seminomas and non-seminomas originate from carcinoma in situ of the testis, which can usually also be detected in seminiferous tubules adjacent to the tumours. In order to contribute with information regarding a possible association between carcinoma in situ and the childhood group of germ cell tumours, we investigated seminiferous tubules adjacent to 13 infantile yolk sac tumours, five infantile teratomas, and six adolescent germ cell tumours of various types, using morphological evaluation, immunohistochemical staining with markers for carcinoma in situ cells, and densitometric DNA measurement of the germ cells. We detected clear differences between the germ cell populations adjacent to adolescent and infantile germ cell tumours. The former were associated with both normal germ cells and carcinoma in situ cells. The presence of carcinoma in situ cells strongly suggested that the adolescent tumours arose from carcinoma in situ cells, like germ cell tumours occurring in adult men. Although we were in doubt in two cases, the infantile germ cell tumours were in general not associated with carcinoma in situ cells. The aetiology of infantile yolk sac tumours and teratomas may therefore be fundamentally different from that of adolescent and adult germ cell tumours. The origin of yolk sac tumours and teratomas remains to be elucidated. 相似文献
32.
Niels Decher reas S. Barth Teresa Gonzalez Klaus Steinmeyer Michael C. Sanguinetti 《The Journal of physiology》2004,557(3):761-772
Kv4.3 channels conduct transient outward K+ currents in the human heart and brain where they mediate the early phase of action potential repolarization. KChIP2 proteins are members of a new class of calcium sensors that modulate the surface expression and biophysical properties of Kv4 K+ channels. Here we describe three novel isoforms of KChIP2 with an alternatively spliced C-terminus (KChIP2e, KChIP2f) or N-terminus (KChIP2g). KChIP2e and KChIP2f are expressed in the human atrium, whereas KChIP2g is predominantly expressed in the brain. The KChIP2 isoforms were coexpressed with Kv4.3 channels in Xenopus oocytes and currents recorded with two-microelectrode voltage-clamp techniques. KChIP2e caused a reduction in current amplitude, an acceleration of inactivation and a slowing of the recovery from inactivation of Kv4.3 currents. KChIP2f increased the current amplitude and slowed the rate of inactivation, but did not alter the recovery from inactivation or the voltage of half-maximal inactivation of Kv4.3 channels. KChIP2g increased current amplitudes, slowed the rate of inactivation and shifted the voltage of half-maximal inactivation to more negative potentials. The biophysical changes induced by these alternatively spliced KChIP2 proteins differ markedly from previously described KChIP2 proteins and would be expected to increase the diversity of native transient outward K+ currents. 相似文献
33.
Atubular glomeruli in patients with chronic pyelonephritis 总被引:2,自引:0,他引:2
N Marcussen T S Olsen 《Laboratory investigation; a journal of technical methods and pathology》1990,62(4):467-473
In an animal model of chronic nephropathy a large proportion of the apparently normal glomeruli have been shown to be small and without connection to a proximal tubule. The present study examines the degree to which atubular glomeruli are also present in human renal disease. Eleven patients with chronic pyelonephritis (CP) and seven controls were investigated. The number of glomeruli connected to a normal proximal tubule was determined in serial sections and the volumes of individual glomeruli estimated with stereological methods. Only glomeruli with little or no sclerosis were investigated. The volume fractions of proximal tubules and interstitial tissue were estimated using point counting. The results showed that 50% of glomeruli in the CP group were connected to a normal proximal tubule, whereas 35% of the glomeruli were without any recognizable connection to a proximal tubule (atubular glomeruli). The remaining 15% were connected to an atrophic tubule. The mean volume of the glomeruli without a connection to a normal proximal tubule was only half that of glomeruli with a normal proximal tubule. No significant difference was found between the mean glomerular volume in the two groups, but the intraindividual variation of glomerular volumes was larger in the CP group. A significant negative correlation was found in the CP group between the percentage of glomeruli without connection to a normal proximal tubule and the volume fraction of proximal tubules. A significant positive correlation was found between the percentage of glomeruli that were not connected to a normal proximal tubule and the volume fraction of the interstitial tissue. This study shows that atubular glomeruli, which only can be identified in serial sections, constitute a large proportion of glomeruli in chronic pyelonephritis. Their existence could be a major reason for the irreversibility of nonglomerular chronic renal diseases. 相似文献
34.
35.
Niels Ødum Niels Morling Johannes Friis Carsten Heilmann Jens J. Hyldig-Nielsen Bodil K. Jakobsen Freddy Karup Pedersen Per Platz Lars P. Ryder Arne Svejgaard 《Tissue antigens》1986,28(4):245-250
Thirty-six unrelated Danish patients with pauciarticular Juvenile Chronic Arthritis (PJCA) and 120 controls were typed for HLA-DPw1-w6 and the local specificity CDPHEI with bulk-expanded Primed Lymphocyte Typing (PLT) cells. The frequency of HLA-DPw2 was 52.8% in PJCA patients and 16.7% in controls (relative risk, RR = 4.5; P less than 0.001). The antigens HLA-Dw5 and/or Dw8 were present in 50% of the patients and in 21.3% of the controls (RR = 4.2; p less than 10(-3)). DPw2 was not associated (in linkage disequilibrium) with Dw5/w8 in patients or in controls, and the DP and D associations with PJCA were independent of each other. However, the combined presence of DPw2 and Dw5 and/or Dw8 gave a significantly higher risk of PJCA than each antigen alone indicating interaction of DP and DR gene products. PJCA is the first disease definitely found to be associated with a DP antigen. 相似文献
36.
p
< 0.05). On postoperative
days 3 and 7 the values were 7.2 (5.3–8.2) and 7.5 (5.4–9.4) mmol/L,
respectively, in the erythropoietin group compared to 6.7 (5.2–7.8)
and 6.9 (5.1–8.6) mmol/L in the placebo group (
p
<
0.01). At discharge the hemoglobin concentration was 7.8 (5.9–8.8)
mmol/L in the erythropoietin group and 7.2 (5.4–8.6) mmol/L in the
placebo group (
p
< 0.002). The blood loss during
operation was similar in the two groups. In the erythropoietin group
the median value was 280 ml (range 25–2000 ml), with the lower and
upper quartiles 150 and 500 ml, respectively. In the placebo group the
blood loss was median 300 ml (range 50–1800 ml), with the lower and
upper quartiles 200 and 750 ml, respectively. The number of blood
transfusions given was significantly lower in the erythropoietin group,
with a mean of 0.3 (range 0–6) units compared to 1.6 (0–9) units in
the control group (
p
< 0.05). In conclusion, the
hemoglobin concentration at the time of surgery and during the week
following surgery was significantly higher in the group of patients
receiving r-HuEPO perioperatively compared to the placebo group
together with a significant lower use of blood transfusions in the
r-HuEPO group. However, the clinical implications of these findings has
yet to be proven.RID=" ID=" <E5>Correspondence to:</E5> N. Qvist, M.D., D.Sci. 相似文献
37.
Leif Henriksen Olaf B. Paulson Niels A. Lassen 《European journal of nuclear medicine and molecular imaging》1981,6(11):487-489
Regional cerebral blood flow (CBF) was studied tomographically with 133Xe administered by inhalation over a 1-min period at a concentration of 10 mCi/l. A fast rotating (dynamic) single-photon emission computed tomograph with four detector heads was used, an instrument that has been found to be well suited for detecting focal ischemia. In the present study its ability to detect focal hyperemia was investigated in 13 normal subjects studied during rest and during visual stimulation. A flickering light seen with eyes open and closed, increased blood flow in the visual cortex by 35% and 22% respectively. Looking at different pictures displayed on a screen raised regional CBF by 26%. The most complex task, reading and copying a text, increased blood flow by 45%. Averaging the different tasks resulted in a mean regional CBF increase in the visual cortex of 35%. The result is comparable with that obtained by positron emission tomography. Both forms of isotope tomography offer unique possibilities for the study of brain function in health and disease, possibilities not matched by X-ray tomography. The low cost and ready availability of appropriate single-photon radionucleides (133Xe and 127Xe) are mentioned.Supported by the Danish Medical Research Council, the Danish Sclerose Association, and the Johann and Hanne Weimann Foundation. 相似文献
38.
Steady-state kinetics of imipramine in patients 总被引:1,自引:0,他引:1
Lars F. Gram Ib Søndergaard Johannes Christiansen Gorm Odden Petersen Per Bech Niels Reisby Ilse Ibsen Jørgen Ortmann Adam Nagy Sven J. Dencker Ove Jacobsen Ole Krautwald 《Psychopharmacology》1977,54(3):255-261
Steady-state plasma level kinetics were studied in 76 patients given imipramine (IP) 150 to 225 mg/day for 2–5 weeks. IP was given in three divided doses at 8.00 a.m., 1.00 p.m. and 5.00 p.m. Plasma concentrations of IP and its active metabolite desipramine (DMI) were determined by quantitative in situ thin-layer chromatography. The plasma levels of IP and DMI showed pronounced flucutations throughout the day with a ratio of about 2 between highest and lowest level. Patients with steady-state levels of IP and/or DMI below 50 g/l reached this within 1 week of treatment. Patients with higher steady-state levels reached steady-state concentrations within 2–3 weeks. There were some intraindividual fluctuations in plasma levels from week to week after steady state had been reached (coefficient of variation: 10–20%). Interindividually, the steady-state levels corrected to a dose of 3.5 mg/kg per day varied considerably: IP: 6–356 g/l, DMI: 24–659 g/l and IP+DMI: 58–809 g/l. The steady-state plasma levels showed a skew distribution that became normal by logarithmic transformation. The IP/DMI ratio ranged from 0.07 to 5.5 with a median value of 0.47. Compared to data from amitriptyline treated patients the IP/DMI ratios had significantly lower median value and larger variation than the corresponding plasma level ratios of amitriptyline/nortriptyline. Several statistically significant differences in steady-state levels between age groups were found. For IP: Women aged 30–39 had lower levels than women aged 20–29, 40–49, and 50–59, and men aged 50–59 and 60–65; men aged 30–39 had lower levels than men aged 60–65. For DMI: Women aged 30–39 had lower levels than women aged 50–59. 相似文献
39.
Cyclooxygenase-2 is a target of KRASD12, which facilitates the outgrowth of murine C26 colorectal liver metastases. 总被引:5,自引:0,他引:5
Niels Smakman Onno Kranenburg Jan M Vogten Alexander L A Bloemendaal Paul van Diest Inne H M Borel Rinkes 《Clinical cancer research》2005,11(1):41-48
PURPOSE: Mutational activation of the KRAS oncogene and overexpression of cyclooxygenase-2 (COX-2) contribute to colorectal carcinoma (CRC) development, but the relationship between these two events is unclear. This study was designed to clarify that relationship and to assess the contribution of KRAS-dependent COX-2 to the seeding of CRC cells in the liver and to their outgrowth as liver metastases in an experimental mouse model. EXPERIMENTAL DESIGN: The effect of RNA interference-mediated KRAS knockdown on COX-2 expression and activity was tested in murine C26 CRC cells. The contribution of KRAS-dependent COX-2 to early metastatic tumor cell seeding (by intravital microscopy) and outgrowth of metastases in the liver (by bioluminescence imaging) was studied by using parecoxib, a novel and highly selective liver-activated COX-2 inhibitor. Intratumoral cell proliferation, apoptosis, and tumor-associated angiogenesis were assessed by immunohistochemistry on liver tissue sections. RESULTS: Stable knockdown of mutant KRAS(D12) in murine C26 CRC cells by RNA interference lead to a dramatic reduction of COX-2 synthesis and prostaglandin E2 production. Inhibition of host or tumor cell COX-2 activity had no effect on early metastatic cell seeding in the liver but greatly reduced intrahepatic tumor cell proliferation and the rate of liver metastasis outgrowth. COX-2 inhibition had no effect on early tumor vascularization or on tumor cell apoptosis. CONCLUSIONS: The high levels of COX-2 enzyme and prostaglandin production in C26 CRC cells are primarily caused by the presence of endogenous mutant KRAS(D12). Furthermore, COX-2 inhibition affects the tumoral rather than the vascular compartment during the early stages of C26 liver metastasis outgrowth. 相似文献
40.
Removing power line noise and other frequency‐specific artifacts from electrophysiological data without affecting neural signals remains a challenging task. Recently, an approach was introduced that combines spectral and spatial filtering to effectively remove line noise: Zapline. This algorithm, however, requires manual selection of the noise frequency and the number of spatial components to remove during spatial filtering. Moreover, it assumes that noise frequency and spatial topography are stable over time, which is often not warranted. To overcome these issues, we introduce Zapline‐plus, which allows adaptive and automatic removal of frequency‐specific noise artifacts from M/electroencephalography (EEG) and LFP data. To achieve this, our extension first segments the data into periods (chunks) in which the noise is spatially stable. Then, for each chunk, it searches for peaks in the power spectrum, and finally applies Zapline. The exact noise frequency around the found target frequency is also determined separately for every chunk to allow fluctuations of the peak noise frequency over time. The number of to‐be‐removed components by Zapline is automatically determined using an outlier detection algorithm. Finally, the frequency spectrum after cleaning is analyzed for suboptimal cleaning, and parameters are adapted accordingly if necessary before re‐running the process. The software creates a detailed plot for monitoring the cleaning. We highlight the efficacy of the different features of our algorithm by applying it to four openly available data sets, two EEG sets containing both stationary and mobile task conditions, and two magnetoencephalography sets containing strong line noise. 相似文献