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41.
A comparative study of attachment of human, bovine and mouse blastocysts to uterine epithelial monolayer 总被引:8,自引:0,他引:8
Lindenberg Svend; Hyttel Poul; Sj?gren Anita; Greve Torben 《Human reproduction (Oxford, England)》1989,4(4):446-456
The in-vitro attachment of human, bovine and murine blastocyststo monolayer cultures of uterine epithelium were studied bytransmission electron microscopy. The human trophoblastic cellsintrude between uterine epithelial cells forming a multilayerduring attachment in vitro, thus resembling the intrusive typeof penetration observed in vivo. The bovine trophoblastic outgrowthresembled an epithelio-chorial attachment as the trophoblastformed an attachment plate on top of the endometrial cells withoutpenetration. In the murine attachment study, the trophoblastcells immediately displaced the uterine cells and formed contactwith the culture vessel. 相似文献
42.
Summary Frozen sections of the corpus ventriculi, antrum pyloricum, duodenum, jejunum, ileum and colon from animals perfusion fixed with glutaraldehyde were treated with an antiserum specific for glutaraldehyde-fixed GABA and processed by the peroxidase antiperoxidase method. Semithin plastic sections from the antrum pyloricum were treated similarly. Stained cells appeared in the epithelium of all segments examined except the corpus ventriculi. The highest density of cells was observed along the major curvature of the antrum pyloricum. Here they were located in the bottom half of the gastric glands. Many of the cells showed a process extending towards the glandular lumen. No significant staining in the epithelium appeared when the antiserum was preincubated with glutaraldehyde-GABA complexes, nor when the anti-GABA serum was exchanged with anti-glycine or preimmune serum. The present findings and previous physiological data suggest that GABA may play a role in gut endocrine regulation. 相似文献
43.
Pedersen K Simonsen M Østergaard SD Munk OL Rosa-Neto P Olsen AK Jensen SB Møller A Cumming P 《NeuroImage》2007,35(1):38-46
The performance of small animal PET for neuroreceptor studies in a psychopharmacological challenge paradigm is not yet well-described. Therefore, we used microPET and [(11)C]raclopride to map the availability of dopamine D(2/3) receptors in brain of anesthetized rats, first in a baseline condition, and again after challenge with saline or d-amphetamine. Parametric maps of the specific binding (binding potential, pB) were calculated using a reference tissue input from cerebellum, and spatially normalized to a digitized stereotaxic coordinate system for rat brain. In volumes of interest (VOIs), the mean baseline pB (n=6) was 2.05 in dorsal striatum (caudate-putamen), and 1.34 in ventral striatum (nucleus accumbens), and did not significantly differ upon retest 2 h later. The availability of [(11)C]raclopride binding sites at baseline was 8% higher in the right striatum. Challenge with amphetamine sulfate (1 mg/kg, i.v., n=4) decreased pB by 19% in both ventral and dorsal striatum. We have earlier predicted that blockade of monoamine oxidase (MAO) should potentiate the amphetamine-evoked dopamine release, thus enhancing the displacement of [(11)C]raclopride binding in vivo. However, pretreatment of rats with pargyline hydrochloride (4 mg/kg, n=4; 20 mg/kg, n=4) 1 day prior to PET did not potentiate the amphetamine-evoked reduction in dopamine receptor availability within the extended striatum. We conclude that small animal PET can be used to investigate stimulant-induced dopamine release, but that the spatial resolution is insufficient to detect differences between relative changes in dorsal vs. ventral divisions of the rat striatum. Furthermore, the present results do not reveal potentiation of the amphetamine-evoked release of dopamine in rats with MAO inhibition. 相似文献
44.
Johannes Soma MD PhD Bjrn A. J. Angelsen Dr Techn Svend Aakhus MD PhD Terje Skjrpe MD PhD 《Journal of the American Society of Echocardiography》2000,13(12):1100-1108
Venodilatation with consequent reduction in left ventricular filling and end-diastolic wall stress is an important mechanism for the beneficial effects of nitroglycerin in ischemic heart disease and in left ventricular failure. The effects of sublingual nitroglycerin on arterial pulsatile hemodynamics are less well defined. Doppler echocardiography and the calibrated subclavian artery pulse tracing were used to assess hemodynamics in subjects with sustained arterial hypertension (n = 25) before and 5 to 10 minutes after sublingual deposition of 0.5 mg glyceryl trinitrate. Aortic characteristic impedance was calculated by averaging the modulus of the input impedance (ratio of pressure to flow) at high frequencies and by calculating the ratio of pressure and flow increments during upstroke. The pressure wave was split into forward and backward components, and the reflection coefficient (the ratio of backward to forward pressures) was calculated. Parameters of the arterial bed were estimated by using 2- and 3-element Windkessel models. Nitroglycerin delayed the return of arterial wave reflections by 17% (P =.02) and increased aortic characteristic impedance by 20% (P =. 01), but it did not influence total arterial compliance. Mean arterial pressure decreased 7% (P =.0001), but pulse pressure did not change. Stroke volume and the acceleration time of aortic root flow decreased by 13% (P =.0001) and 8% (P =.01), respectively. Cardiac output decreased 7% (P =.01), despite an increase in heart rate of 10% (P =.0001). Peripheral resistance tended to decrease (4%, P =.06). Thus, in subjects with sustained hypertension, sublingual nitroglycerin dilates peripheral, predominantly muscular arteries with a subsequent delayed return of reflected pressure waves. Reflex activation of the sympathetic nervous system with consequent increased acceleration of left ventricular ejection seems to counteract the effect of reduced mean arterial pressure (distending pressure) with respect to the "stiffness" of the aorta. 相似文献
45.
Olaf Rodevand Reidar Bjornerheim Svend Aakhus John Kjekshus 《The international journal of cardiovascular imaging》1998,14(1):55-63
Three-dimensional (3D) echocardiography may overcome the problems with inadequate accuracy and reproducibility of 2D volume measurements of the left ventricle. Aims: To establish the in vitro accuracy and reproducibility of two new methods for 3D echocardiographic volume determination as compared to biplane measurements. Methods: Validation of volume measurements by a multiplane 3D method was performed on asymmetric latex phantoms (n=8, true volumes 45-304 ml) using rotational acquisition of 90 image planes. Porcine agarose-filled asymmetrical left ventricles (n=7, true volumes 34 – 280 ml) were measured by the same multiplane 3D method based on images acquired by probe rotation axis perpendicular (A) and parallel (B) to the ventricular long axis. Ventricular volumes were also obtained by a simplified 3D system using only the three standard apical views (C) and by the ordinary biplane Simpson’s method (D). Results: On latex phantoms systematic deviation from true volumes by multiplane 3D was less than 2%, and 95% variability of individual measurements from this mean was ± 4,9%. For accuracy on left ventricles, systematic bias was small with all the methods (<5%), but 95% variability of individual measurements was ±9,0%, 15.4%, 18.8% and 41.3% of true volumes for methods A-D respectively. Corresponding results in the same range were obtained for inter- and intraobserver variability. Conclusion: Individual in vitro volume estimates of left ventricles are of similar quality using apical multiplane or apical triplane 3D echocardiography. Both methods were superior to the ordinary apical biplane method, but inferior to multiplane 3D method with the probe directed perpendicular to the ventricular long axis. 相似文献
46.
Lithium clearance in chronic nephropathy 总被引:1,自引:0,他引:1
A L Kamper N H Holstein-Rathlou P P Leyssac S Strandgaard 《Clinical science (London, England : 1979)》1989,77(3):311-318
1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption of lithium or influence of osmotic diuresis. 3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min. 4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min. 5. Lithium clearance data were independent of whether renal disease was of primarily glomerular or tubular origin and, further, were not influenced by long-term conventional antihypertensive treatment. 6. It is concluded that, even with a reduced kidney function, the data are compatible with the suggestion that lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct). With more severe impairment the proximal tubule also becomes involved in the adjustment. 相似文献
47.
48.
Fog LS Rasmussen JF Aznar M Kjær-Kristoffersen F Vogelius IR Engelholm SA Bangsgaard JP 《Physics in medicine and biology》2011,56(6):1853-1863
RapidArc? has become the treatment of choice for an increasing number of treatment sites in many clinics. The extensive use of multiple subfields in RapidArc? treatments presents unique challenges, especially for small targets treated in few fractions. In this work, very small static fields and subsequently RapidArc? and conventional plans for two targets (0.4 and 9.9 cm(3)) were investigated. Doses from static fields 1-4 MLC leaves (0.25-1.00 cm) wide, and larger fields with 1-4 MLC leaves closed in their centres, were measured using the portal dosimeter-based QA system EPIQA (v?1.3) and gafchromic film. RapidArc and conventional plans for two tumours were then measured using EPIQA, gafchromic EBT2 film and the phantom-based QA system Delta4. Eclipse 8.6 and 8.9, grid spacings of 1.25 and 2.50 mm and a Varian HD linac were used. For static fields one MLC leaf wide, the dose was underestimated by Eclipse by as much as 53% (v?8.6, 2.5 mm grid). Eclipse underestimated the dose downstream from a few MLC leaves closed in the centre of a large MLC field by as much as 30%. Eclipse consistently overestimated the width of the penumbra by about 100%. For the conventional plans, there was good agreement between the calculated and measured dose for the 9.9 cm(3) PTV, but a 10% underdose was observed for the 0.4 cm(3) PTV. For the RapidArc? plans, the measured dose for the 9.9 cm(3) PTV was in good agreement with the calculated one. However, for the 0.4 cm(3) PTV about 10% overdosing was detected (Eclipse v 8.6, 2.5 mm grid spacing). EPIQA data indicated that the measured dose profiles were overmodulated compared to the calculated one. The use of small subfields, typically a few MLC leaves wide, or larger fields with one or a few MLC leaves closed in its centre can result in significant errors in the dose calculation. The detector systems used vary in their ability to detect the discrepancies. Using a smaller grid size and newer version of Eclipse reduces the discrepancies observed in this work but does not eliminate them. 相似文献
49.
Nielsen EH Lindholm J Laurberg P Bjerre P Christiansen JS Hagen C Juul S Jørgensen J Kruse A Stochholm K 《Pituitary》2007,10(1):67-73
The incidence of clinically significant, nonfunctioning pituitary adenoma, requiring surgical treatment, has not been established.
According to previous studies, both surgery type and subsequent radiotherapy may have an impact on quality of life (QOL),
and some studies have shown increased cardiovascular mortality in patients with pituitary disease. We studied all patients
with functionless, suprasellar pituitary adenoma who were operated on during the period 1985–1996 (N = 192; transsphenoidal surgery = 160, craniotomy = 32). QOL was evaluated from Short Form 36 and Major Depression Inventory
questionnaires. Causes of death were obtained from the Danish Register of Causes of Death. Incidence was 5.6/mill/year. Postoperatively,
27% of the patients had normal pituitary function and 27% were panhypopituitary. Fifty three patients had died. Death from
cardiovascular, cerebrovascular and malignant diseases was not increased. Overall, QOL was not different from QOL of an age-
and sex matched background population. QOL was, however, impaired in patients who had undergone craniotomy as compared to
patients undergoing transsphenoidal surgery. QOL was not reduced in hypopituitary patients or in patients receiving radiotherapy.
The study was supported by grants from The Aarhus University Hospital Research Initiative and The Obel Family Foundation,
Aalborg, Denmark 相似文献
50.
Thøgersen J Knudsen CS Maetzke A Jensen SJ Keiding SR Alsner J Overgaard J 《International journal of radiation biology》2007,83(5):289-299
PURPOSE: High intensity femtosecond (1 fs = 10(-15) s) laser pulses may, via multi-photon processes, cause reproductive cell death at wavelengths that otherwise are harmless. We study the efficacy of inducing reproductive death of cancer cells by ultraviolet (UV), visible (VIS) and near infrared (IR) femtosecond laser pulses. MATERIALS AND METHODS: Human squamous carcinoma cervical cancer cells are irradiated by femtosecond laser pulses at 800 nanometers (nm), 400 nm, 266 nm and 200 nm. The reproductive death is assessed by colony forming assay. The contribution from multi-photon processes is evaluated by comparing the cell reproduction subsequent to irradiation by collimated (low intensity) and focused (high intensity), pulsed laser beams with identical fluences. RESULTS: Suitable femtosecond pulses are capable of arresting cell reproduction at all the tested wavelengths. Irradiation at 266 nm is far more efficient than the other wavelengths, both in terms of the fluence and the absorbed dose needed to induce reproductive cell death. The collimated 800 nm beam is unable to induce reproductive cell death even at a fluence of 230 Joule/square centimeters (J/cm2). However, focused 800 nm pulses with much higher intensities, but lower fluences efficiently arrest cell reproduction, thus highlighting the dramatic effect of multi-photon processes. At the intensities used in the present work focusing the 400 nm beam improves its efficacy by an order of magnitude, whereas focusing the 266 nm beam does not improve its efficacy. CONCLUSION: Femtosecond pulses at 200, 266, 400 and 800 nm induce reproductive cell death if the intensity is sufficiently high. Multi-photon processes can improve the efficacy substantially and even result in reproductive cell death at wavelengths, where single-photon processes are harmless. 相似文献