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81.
We describe three cases of fetal intracranial teratoma diagnosed by ultrasound and review the literature. Sonographic features include cranial enlargement, gross distortion of normal cerebral architecture by a hyperechoic, multicystic mass, and polyhydramnios. Despite early diagnosis, the cesarean section rate is high and the overall prognosis is dismal. 相似文献
82.
83.
中药升麻的化学成分 总被引:14,自引:0,他引:14
从中药兴安升麻[Cimicifuga dahurica(Turcz.)Maxim.]的干燥根茎中分得五个化合物,其中四个为三萜木糖甙:升麻醇-3-O-β-D-吡喃木糖甙(23R,24S)(Ⅰ),25-O-乙酰升麻醇-3-O-β-D-吡喃木糖甙(23R,24S)(Ⅱ),12-羟基升麻醇-3-O-β-D-吡喃木糖甙(23R,24S)(Ⅲ),升麻醇-3-O-β-D-吡喃木糖基(3→1)-β-D-吡喃木糖甙(23R,24S)(Ⅳ),另一个为异阿魏酸(Ⅴ)。Ⅲ和Ⅳ为新化合物,通过光谱(IR,MS,1H及13C NMR)解析确定了它们的结构,分别命名为升麻甙A(cimiside A)和升麻甙B(cimiside B)。 相似文献
84.
PL Perrotta ; L Baril ; C Tead ; J Chapman ; D Dincecco ; DH Buchholz ; EL Snyder 《Transfusion》1999,39(1):63-69
BACKGROUND: Photochemical methods can effectively inactivate extracellular viruses and bacteria found in blood components. Treatment of plasma with methylene blue (MB), a phenothiazine dye, and visible light inactivates enveloped viruses including HIV-1. The effects of MB- treated plasma on cellular components stored in vitro have not been well characterized. STUDY DESIGN AND METHODS: MB-treated plasma (83 microg MB/250 mL plasma) was added to single-donor platelets, stored AS- 1 red cells (RBCs), irradiated RBCs, and frozen-deglycerolized RBCs. In vitro platelet assays performed after 1 and 5 days of storage in MB- treated plasma included pH, pO2, pCO2, HCO3, platelet number, lactate dehydrogenase, glucose, osmotic recovery, and CD62 expression. RBC components were examined at specific intervals for leakage of potassium, plasma hemoglobin level, and percentage of hemolysis. Direct antiglobulin tests, osmotic fragilities, and RBC antigen stability tests were also performed on RBCs stored in MB-treated plasma. Components stored with autologous plasma or nontreated allogeneic plasma served as controls. RESULTS: Similar storage-induced changes in pH, glucose, and platelet numbers, as well as increases in lactate dehydrogenase, CD62 expression, and lactate were seen in single-donor platelets stored with MB-treated and control plasma. Platelet morphology scores and osmotic recoveries were not altered. Plasma hemoglobin and potassium and percentage of hemolysis increased equally in the various RBC components stored with MB-treated or nontreated plasma. Osmotic fragility and RBC antigen stability were not appreciably altered by MB-treated plasma. CONCLUSION: Plasma treated by MB photoinactivation can be used for in vitro resuspension and storage of platelets or RBCs, because of the lack of influence of MB-treated plasma on a variety of in vitro platelet and RBC assays. 相似文献
85.
SA Rabacchi JM Solowska B Kruk Y Luo JA Raper DH Baird 《The Journal of neuroscience》1999,19(11):4437-4448
Most axons in the CNS innervate specific subregions or layers of their target regions and form contacts with specific types of target neurons, but the molecular basis of this process is not well understood. To determine whether collapsin-1/semaphorin-III/D, a molecule known to repel specific axons, might guide afferent axons within their cerebellar targets, we characterized its expression by in situ hybridization and observed its effects on mossy and climbing fiber extension and growth cone size in vitro. In newborn mice sema-D is expressed by cerebellar Purkinje cells in parasagittal bands located medially and in some cells of the cerebellar nuclei. Later, sema-D expression in Purkinje cells broadens such that banded expression is no longer prominent, and expression is detected in progressively more lateral regions. By postnatal day 16, expression is observed throughout the cerebellar mediolateral axis. Collapsin-1 protein, the chick ortholog of sema-D, did not inhibit the extension of neurites from explants of inferior olivary nuclei, the source of climbing fibers that innervate Purkinje cells. In contrast, when it was applied to axons extending from basilar pontine explants, a source of mossy fiber afferents of granule cells, collapsin-1 caused most pontine growth cones to collapse, as evidenced by a reduction in growth cone size of up to 59%. Moreover, 63% of pontine growth cones arrested their extension or retracted. Its effects on mossy fiber extension and its distribution suggest that sema-D prevents mossy fibers from innervating inappropriate cerebellar target regions and cell types. 相似文献
86.
HPLC法测定地西泮和艾司唑仑的血药浓度 总被引:9,自引:0,他引:9
建立HPLC法同时测定地西泮和艾司唑仑血药浓度。方法:以Ultrasphere-ODS5μm4.6mm*25cm色谱柱为分离柱,流动相:甲醇-乙腈-水(40:20:40);检测波长为254nm,以外标法峰面积定量。结论本法可用于血药浓度测定。 相似文献
87.
Ankit Butola David A. Coucheron Karolina Szafranska Azeem Ahmad Hong Mao Jean-Claude Tinguely Peter McCourt Paramasivam Senthilkumaran Dalip Singh Mehta Krishna Agarwal Balpreet Singh Ahluwalia 《Proceedings of the National Academy of Sciences of the United States of America》2021,118(47)
Visualization of three-dimensional (3D) morphological changes in the subcellular structures of a biological specimen is a major challenge in life science. Here, we present an integrated chip-based optical nanoscopy combined with quantitative phase microscopy (QPM) to obtain 3D morphology of liver sinusoidal endothelial cells (LSEC). LSEC have unique morphology with small nanopores (50-300 nm in diameter) in the plasma membrane, called fenestrations. The fenestrations are grouped in discrete clusters, which are around 100 to 200 nm thick. Thus, imaging and quantification of fenestrations and sieve plate thickness require resolution and sensitivity of sub-100 nm along both the lateral and the axial directions, respectively. In chip-based nanoscopy, the optical waveguides are used both for hosting and illuminating the sample. The fluorescence signal is captured by an upright microscope, which is converted into a Linnik-type interferometer to sequentially acquire both superresolved images and phase information of the sample. The multimodal microscope provided an estimate of the fenestration diameter of 119 ± 53 nm and average thickness of the sieve plates of 136.6 ± 42.4 nm, assuming the constant refractive index of cell membrane to be 1.38. Further, LSEC were treated with cytochalasin B to demonstrate the possibility of precise detection in the cell height. The mean phase value of the fenestrated area in normal and treated cells was found to be 161 ± 50 mrad and 109 ± 49 mrad, respectively. The proposed multimodal technique offers nanoscale visualization of both the lateral size and the thickness map, which would be of broader interest in the fields of cell biology and bioimaging.Far-field optical nanoscopy techniques are frequently used to visualize subcellular structures in biological specimens by surpassing the diffraction limit. Optical nanoscopy encompasses a plethora of techniques, including stimulated emission depletion microscopy (1), structured illumination microscopy (SIM) (2), different variants of single-molecule localization microscopy (SMLM), such as photo-activated localization microscopy (3) and direct stochastic optical reconstruction microscopy (dSTORM) (4), and intensity fluctuation–based techniques such as superresolution optical fluctuation imaging (5). These techniques can help detect subcellular structures (<200 nm) of biological specimens such as lipids, proteins, membrane structures, microtubules, and nucleic acids by specific fluorescence tagging (6). Each technique has respective advantages and disadvantages; for example, SIM has gained popularity for live-cell imaging due to its fast image acquisition time but at limited spatial resolution (7). dSTORM, on the other hand, is slower but offers high resolution for characterization of viral proteins (8) and imaging actin filaments in mammalian cells (9, 10), for example. To reduce the complexity of the typical SMLM setup using a total internal reflection fluorescence (TIRF) configuration, a photonic chip-based optical nanoscopy system was recently proposed (11–13). In the chip-based system, a photonic integrated circuit is used to replace the usual free space optics for excitation. The collection, however, is done through free space optics. The main advantage of this configuration is the decoupling of excitation and collection pathways as well as miniaturization of the excitation light path of the system. In chip-based nanoscopy, the TIRF illumination is generated through the evanescent field of waveguides rather than using conventional high magnification and high numerical aperture (N.A.) TIRF lens. The evanescent field in waveguides can be generated over extraordinarily large areas, as it is only defined by the waveguide geometry. The waveguide geometry makes it possible to use any imaging objective lens to image arbitrarily large areas as compared to the traditional TIRF-based dSTORM (12), which is limited by the field of view (FOV) of the TIRF lens.Quantitative phase microscopy (QPM) is a label-free optical microscopy technique, which facilitates sensitive measurements of the refractive index and thickness of both biological specimens (14). Various QPM methods have been proposed so far for extracting optical phase and dynamics of biological cells (15–17). These techniques offer high phase sensitivity (spatial and temporal), transverse resolution, and high imaging speed (15). The spatial and temporal phase sensitivity of the QPM system is highly dependent on the illumination source and the type of interferometric geometry, respectively (17–19). For example, common path QPM techniques offer better temporal phase sensitivity, which can be used to measure membrane fluctuation of the cells (20). In addition, spatial phase sensitivity of the system can be improved by using low-coherence light sources (halogen lamps and light-emitting diodes [LED]) but requires phase-shifting techniques to utilize the whole FOV of the camera (21). A recent advancement in the QPM technique with superior resolution using structured illumination (22, 23) and three-dimensional (3D) information of the samples has been shown by measuring the phase across multiple angles of illumination. This technique facilitates tomography of various biological specimens such as red blood cells, HT29 cells, and bovine embryos (17, 24). Since the lateral resolution of the QPM technique depends on the N.A. of the objective lens, imaging beyond the diffraction limit (<200 nm) is still challenging and limits the study of subcellular structures. Therefore, it is useful to develop multimodality routes in which different microscopy methods can be utilized to provide complementary information about biological specimens such as liver sinusoidal endothelial cells (LSEC).Fig. 1 depicts LSEC that contain large numbers of fenestrations. These transcellular nanopores vary in diameter from 50 to 300 nm, which is just below the diffraction limit of optical microscopy (25–27). Fenestrations are typically clustered in groups of 5 to 100 within areas called sieve plates (28). The porous morphology of LSEC acts as an ultrafilter between blood and the underlying hepatocytes, facilitating the bidirectional exchange of substrates between the interior of the liver and blood. For example, smaller viruses and drugs can pass this barrier, while blood cells are retained within the sinusoidal vessel lumen (25, 29). The typical thickness of sieve plates is around 100 to 150 nm (30), so fenestrations are consequently nanoscale sized in all three dimensions. As shown in Fig. 1, the fenestrations in sieve plates form openings through the entire LSEC cell body, and therefore TIRF illumination is ideally suited for imaging these structures. Determining the diameter and number of fenestrations, as well as the height of sieve plate regions, is important, as it can be affected by several drugs and conditions (31, 32). The loss of LSEC porous morphology, a process called defenestration, compromises the filtration properties of the liver, which may lead to atherosclerosis (33). Moreover, aging results in “pseudocapillarization,” whereby LSEC simultaneously lose fenestrations and become thicker (34) (Fig. 1). This is believed to be a main factor contributing to the age-related need to increase doses of drugs targeting hepatocytes (e.g., statins) that have to pass through the fenestrations (35). The number of fenestrations in vitro can be increased using actin disrupting agents such as cytochalasin B (27). This treatment decreases the height of LSEC outside of the nuclear area, which contributes to the formation of new fenestrations (36).Open in a separate windowFig. 1.Top view (A) and cross-sectional view (B) of LSEC. LSEC have unique morphology, in which nanoscopic fenestrations are grouped in thin sieve plates. The diameter of fenestrations and thickness of sieve plates are below the diffraction limit of conventional optical microscopes. The number and size of fenestrations, but also LSEC thickness, can be affected by aging and in liver diseases. In vitro, the number of fenestrations can be increased using actin disrupting agents, such as cytochalasin B (27).Here, we have developed a multimodal chip-based optical nanoscopy and highly sensitive QPM system to visualize the 3D morphological changes in LSEC. The proposed system decouples the light illumination path from the collection path and thus enables a straightforward integration of dSTORM and QPM. The nanoscale phase sensitivity of the QPM technique is utilized to extract the optical thickness of sieve plates. Moreover, chip-based dSTORM supports superresolution imaging down to 50 nm over an extraordinarily large FOV up to millimeter scale (12). Therefore, integration of dSTORM and QPM allows superresolution imaging in the lateral dimension (with dSTORM) and nanometric sensitivity in the axial direction (with QPM). In this work, we demonstrate the capabilities of the system by imaging LSEC with both diffraction-limited TIRF microscopy and dSTORM. The fenestrations and sieve plates are observable with dSTORM, and the average optical thickness of the sieve plate region is obtained using diffraction-limited QPM. Furthermore, we investigated the change in the interior morphology of sieve plates by treating the cell with cytochalasin B (10 μg/mL). The deficiency of lateral resolution of QPM was compensated by dSTORM, which enabled us to localize the sieve plate regions containing subdiffraction-sized fenestration. Therefore, in the cell membrane regions distal from the nucleus, the 3D morphology of LSEC can be reconstructed reliably using our multimodal approach. The integrated system offers a combination of simultaneous functional and quantitative imaging of the cells with large FOV, providing a compact imaging platform with a potential for high-throughput morphological and nanometric imaging for specific biological applications. 相似文献
88.
Kirsten JE Asmus-Szepesi Paul L de Vreede Anna P Nieboer Jeroen DH van Wijngaarden Ton JEM Bakker Ewout W Steyerberg Johan P Mackenbach 《BMC geriatrics》2011,11(1):1-17
Background
Elderly persons admitted to the hospital are at risk for hospital related functional loss. This evaluation aims to compare the effects of different levels of (integrated) health intervention care programs on preventing hospital related functional loss among elderly patients by comparing a new intervention program to two usual care programs.Methods/Design
This study will include an effect, process and cost evaluation using a mixed methods design of quantitative and qualitative methods. Three hospitals in the Netherlands with different levels of integrated geriatric health care will be evaluated using a quasi-experimental study design. Data collection on outcomes will take place through a prospective cohort study, which will incorporate a nested randomised controlled trial to evaluate the effects of a stay at the centre for prevention and reactivation for patients with complex problems. The study population will consist of elderly persons (65 years or older) at risk for functional loss who are admitted to one of the three hospitals. Data is prospectively collected at time of hospital admission (T0), three months (T1), and twelve months (T2) after hospital admission. Patient and informal caregiver outcomes (e.g. health related quality of life, activities of daily living, burden of care, (re-) admission in hospital or nursing homes, mortality) as well as process measures (e.g. the cooperation and collaboration of multidisciplinary teams, patient and informal caregiver satisfaction with care) will be measured. A qualitative analysis will determine the fidelity of intervention implementation as well as provide further context and explanation for quantitative outcomes. Finally, costs will be determined from a societal viewpoint to allow for cost effectiveness calculations.Discussion
It is anticipated that higher levels of integrated hospital health care for at risk elderly will result in prevention of loss of functioning and loss of quality of life after hospital discharge as well as in lower burden of care and higher quality of life for informal caregivers. Ultimately, the results of this study may contribute to the implementation of a national integrated health care program to prevent hospital related functional loss among elderly patients.Trial registration
The Netherlands National Trial Register: NTR2317 相似文献89.
Summary
This study examined the effects of quercetin on spontaneously contracting portal veins isolated from healthy young adult male and female Wistar rats (250–300 g). Quercetin (10-7–10-4 M) always produced significant biphasic effects, comprising an initial brief stimulant effect (rise in basal tone), followed by a sustained, longer-lasting secondary relaxant (inhibitory) effect on the venous tissues. The initial brief contractions of the venous muscle preparations were not modified by preincubation of the tissues with prazosin (10-6 M), suggesting that the initial upsurge in basal tone and increases in contractile frequencies of the venous tissues were probably not mediated via alpha1-adrenoceptor stimulation. However, preincubation of the tissues with nifedipine (10-7 M) significantly suppressed (p < 0.05) or attenuated the initial stimulant effect of quercetin, suggesting that the flavonoid might be activating L-type voltage-dependent calcium channels. The vasorelaxant effect of quercetin was partially but not significantly (p > 0.05) inhibited by L-NAME (100 μM) or indomethacin (10 μM), suggesting that the vasorelaxant effect of the flavonoid was unlikely to be mediated via endothelium-dependent relaxing factor (EDRF), or through prostacyclin (PGI2) pathways. N-p-tosyl-l-phenylalanine-chloromethyl-ketone (TPCK, 3 μM) significantly (p < 0.01) antagonised quercetin-induced relaxations, suggesting that cAMP-dependent protein kinases might have contributed, at least in part, towards the vasorelaxant effect of quercetin on rat isolated portal veins. 相似文献90.