To evaluate patient acceptance, optical properties and the clinical feasibility of flexible compared with rigid hysteroscopes, 142 patients undergoing outpatient hysteroscopy were included in a prospective, randomized clinical trial. The flexible hysteroscope was used in 70 patients, and the rigid instrument in 72. At different stages of the hysteroscopy the level of pain experienced by the women was assessed using a 10 cm visual analogue scale. Optical properties characterized by the parameters intrauterine visibility, hysteroscopic view and diagnostic accuracy were ranked by the surgeons using a 5-point scale (1 = excellent to 5 = insufficient), and duration of the hysteroscopy was measured. Hysteroscopy was successful in 87.5 and 100% of patients in the flexible and rigid groups respectively. With the use of rigid telescopes, discomfort at introduction and during the hysteroscopy was significantly greater (median 1.7 versus 0.7, P = 0.003; 3.1 versus 1.2, P < 0.001 respectively), but optical properties were judged to be far superior (P < 0.001 for all three comparisons) and procedure time was significantly shorter (median 70 versus 120 s, P = 0.003). In conclusion, outpatient hysteroscopy seems to be less painful when using flexible telescopes. However, rigid hysteroscopes provide superior optical qualities and permit a more rapid performance with higher success rates at much lower cost. 相似文献
The effect of both intrahypothalamic and systemic administration of guanosine triphosphate (GTP) on lordosis behavior was studied in ovariectomized and ovariectomized-adrenalectomized, estrogen-primed rats (estradiol benzoate, 4 μg). This estrogen dose per se induced only weak or no lordosis behavior. Injection of GTP into the medial hypothalamic area (100 μg in 2.5 μl) elicited lordosis behavior with relatively short latency in 6 out of 7 rats. Systemic administration of GTP in a dose range of 0.8 mg to 5.0 mg to ovariectomized estrogen-primed rats, stimulated intense lordosis behavior in all subjects. Weak lordosis responses were displayed within the first 12 hr after GTP injection, but at 48 hr all rats were highly estrous. Lordosis behavior remained for up to eight days, its duration being related to the dose of GTP administered. GTP (2 mg) induced lordosis behavior in ovariectomized, adrenalectomized estrogen-primed rats, thus excluding the participation of adrenal steroids in this effect. The results are interpreted in terms of the stimulation of adenyl cyclase-cAMP systems by GTP. 相似文献
Summary: Various poly(ε‐caprolactone‐block‐1,4‐dioxan‐2‐one) (P(CL‐block‐PDX)) block copolymers were prepared according to the living/controlled ring‐opening polymerization (ROP) of 1,4‐dioxan‐2‐one (PDX) as initiated by in situ generated ω‐aluminium alkoxides poly(ε‐caprolactone) (PCL) chains in toluene at 25 °C. 1 1H NMR, PCS and TEM measurements have attested for the formation of colloids attributed to a growing PPDX core surrounded by a solvating PCL shell during the polymerization of PDX promoted by ω‐Al alkoxide PCL chains in toluene. The thermal behavior of the P(CL‐block‐PDX) copolymers was studied by DSC; showing two distinct melting temperatures (as well as two glass transition temperatures) similar to those of the respective homopolyesters. Finally, the thermal degradation of the P(CL‐block‐PDX) block copolymers was investigated by TGA simultaneously coupled to a FT‐IR spectrometer and a mass spectrometer for evolved gas analysis (EGA). The degradation occurred in two consecutive steps involving a first unzipping depolymerization of the PPDX blocks followed by the degradation of the PCL blocks via both ester pyrolysis and unzipping reactions.
TEM observation of P(CL‐block‐PDX) block copolyesters ( = 11 600 and = 22 100) as formed by vaporization starting from a diluted suspension in toluene/TCE mixture solvent (50/50 v/v). 相似文献
Summary: Light‐induced reversible changes in elasticity of semi‐interpenetrating network (semi‐IPN) films bearing azobenzene moieties were achieved under both ultraviolet (UV) and visible light irradiation. The semi‐IPN film was prepared by a cationic copolymerization of azobenzene‐containing vinyl ethers in a linear polycarbonate (PC) film as a matrix. When the irradiation was switched on and off, the semi‐IPN film showed rapid reversible deformation with the same behavior occurring over a range of wavelengths, including both the UV and visible regions. The observed reversible deformation of the film was attributed to the decrease in the film's elasticity, which was assumed to be caused by the frequent trans‐cis cycling isomerization of azobenzene moieties taking place during the UV and visible light irradiation. This cycling makes it difficult for the azobenzene groups to aggregate, thus hindering their ability to function as pseudo‐crosslinking points.
Previous studies have reported an association of the cell surface adhesion molecule CD2 with the T cell receptor and with CD45 on mouse and human T lymphocytes. In this study the association of CD2 with cell surface molecules was investigated using cell surface biotinylation of T lymphocytes, coupled with immunoprecipitation using two CD2-specific monoclonal antibodies (mAb) (RM2–5 and 12–15) and analysis by SDS-PAGE. Although both CD2 mAb immunoprecipitated CD2 from lysates of murine lymphocytes, it was found that mAb 12–15, but not RM2–5, co-precipitated two other molecules of 95 and 180 kDa. Subsequent studies revealed that the 95- and 180-kDa molecules were associated with a subspecies of CD2 (? 5%) on thymocytes, the antigen-specific T cell line D10, and splenic T cells but not B cells. Two lines of evidence were obtained consistent with the 95- and 180-kDa molecules being the β and α chains of LFA-1. Firstly, an analysis of 12–15 mAb immunoprecipitates on 4–12% gels under reducing and nonreducing conditions shows that the 95- and 180-kDa molecules have a molecular weight and migration pattern identical to LFA-1. Secondly, depletion of LFA-1 from lysates with LFA-1 mAb abolished the ability of CD2 mAb 12–15 to co-precipitate the 95- and 180-kDa molecules, thereby identifying these as the β and α chains of mouse LFA-1, respectively. These results provide evidence for the first time for an association of LFA-1 and CD2 on mouse T lymphocytes, and suggest that the association occurs with an immunologically distinct subspecies of CD2 molecules. 相似文献
To test the hypothesis that chronic immune stimulation of a peripheral lymph node induces the formation of additional mature adipocytes in adjacent adipose tissue, one popliteal lymph node of large male rats was stimulated by local injection of 10 microg or 20 microg lipopolysaccharide three times a week for 6 weeks. Adipocyte volumes in sites defined by their anatomical relations to the stimulated and homologous unstimulated popliteal lymph nodes were measured, plus adipocyte complement of the popliteal depot, and the lipid and protein content of adipocytes and adipose stroma. The higher dose of lipopolysaccharide doubled the mass of the locally stimulated lymph node and the surrounding adipose tissue enlarged by the appearance of additional mature adipocytes. Similar but smaller changes were observed in the popliteal adipose depot of the unstimulated leg and in a nodeless depot. The lipid content of the adipocytes decreased and that of the stroma increased dose-dependently in all samples measured but the changes were consistently greater in the depot surrounding the stimulated lymph node. The protein content of both adipocytes and stroma increased in samples surrounding the stimulated node. We conclude that chronic immune stimulation of lymphoid tissues induces the formation of more adipocytes in the adjacent adipose tissue. These findings suggest a mechanism for the selective hypertrophy of lymphoid-containing adipose depots in the HIV-associated adipose redistribution syndrome. 相似文献
The purpose of this study was to use a model of aging to examine the relationships between passive properties of the calf
muscles and plantarflexion concentric isokinetic torque characteristics. Eighty-one active women 20–84 years of age were tested
using a Kin-Com isokinetic dynamometer interfaced with electromyography (EMG). The passive properties were tested by stretching
the muscles from relaxed plantarflexion to a maximal dorsiflexion (DF) angle at a rate of 5°·s–1 (0.087 rad·s–1) with minimal raw EMG activity (<0.05 mV). The maximal concentric torque was tested from maximal passive DF into plantarflexion
at four randomly ordered velocities of 30, 60, 120, and 180°·s–1. Pearson correlation coefficients (Bonferroni adjusted) indicated a hierarchical order of high to moderate positive correlations
between four passive properties and the peak and mean concentric torque for all test velocities. Correlation coefficients
for the four passive properties ranged from 0.50 to 0.78 (P<0.001), and the coefficients of determination (r2) from higher to lower were: (1) maximal DF passive resistive torque (r2: 0.50–0.62), (2) length extensibility (r2: 0.40–0.49), (3) maximal muscle length (r2: 0.28–0.41), and (4) passive elastic stiffness in the last half of the full-stretch range of motion (r2: 0.25–0.31). The maximal DF passive resistive torque and the length extensibility accounted for 50–62% and 40–49% of the
variability in the concentric torque, respectively. The results indicate that the concentrically stronger calf muscles of
active women were positively correlated with passively stronger, longer, and stiffer calf muscles, which are characteristics
of the calf muscles of younger women. Further studies are needed to examine whether therapeutic interventions, such as stretching
and strengthening, can promote adaptations in the calf muscles of older women to attain these more youthful characteristics.
Electronic Publication 相似文献