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71.
The purpose of this study was to compare two methods for evaluating periapical healing in humans: the periapical index (PAI) and a gray value correction method. Fifty human teeth with a periapical lesion were endodontically treated. Radiographs, with a special aluminum device, were taken postoperatively, after 3 months and after 6 months. The PAI was recorded at each period of time, and a Kruskall and Wallis test was performed to compare the three groups. After scanning, the size of the lesion and its gray value were recorded. The aluminum device allowed the gray values to be equalized. An analysis of variance followed by a Duncan test was performed to compare the three groups. The teeth that showed no sign of healing according to the PAI were separately analyzed by an analysis of variance and a Duncan test. The PAI (n = 50) showed signs of periapical healing over time (p < 0.01). The analysis of variance, based on gray value evaluation (n = 50), also showed signs of periapical healing over time (p < 0.002). The analysis of variance of teeth with the same PAI over time (n = 15 at 3 months, and n = 5 at 6 months), based on gray value evaluation showed statistically significant differences among the 3 groups (p < 0.02). These results show that the gray level correction method is powerful and may reduce the risks of false negative responses during assessment of treatment results or epidemiological studies.  相似文献   
72.
BACKGROUND: Decreased motion of the subtalar joint is common after operative treatment of idiopathic clubfeet. The purposes of this study were to validate parameters of dynamic foot-pressure measurement that enable detection of physiological pronation of the subtalar joint and to analyze the consequences of absent or decreased pronation following clubfoot surgery on long-term functional results. METHODS: To validate parameters of dynamic foot-pressure measurement, we initially analyzed two control groups: one of forty asymptomatic normal feet and the other of five feet with a previous subtalar joint arthrodesis. The resulting parameters were then applied to a group of nineteen patients with twenty-four idiopathic clubfeet for whom initial conservative treatment had failed and in whom a posterior surgical release (lengthening of the Achilles tendon and release of the posterior ankle capsule) had been performed at a mean age of twenty months. The mean duration of follow-up was forty-one years. All feet were evaluated radiographically, and the clinical results were assessed with the American Orthopaedic Foot and Ankle Society score. RESULTS: An interruption in the rise of the pressure-time curve and a short medial deviation of the center of pressure path immediately after heel strike are reliable and objective characteristics of pronation movement of the subtalar joint. Nineteen clubfeet had a demonstrable pronation movement, and five clubfeet did not. The nineteen feet with pronation movement were either asymptomatic (twelve feet) or mildly painful on occasion (seven feet). The mean American Orthopaedic Foot and Ankle Society score for the nineteen feet was 87 points. The five feet without pronation movement were moderately painful during strenuous activities only (four feet) or were nearly always painful (one foot). The mean score for those feet was 57 points. There was a significant difference between these two groups with regard to the pain scores and the total scores (p < 0.001), but there was no appreciable difference regarding function and hindfoot motion. It was not possible to distinguish between these two groups on the basis of the findings of the physical or radiographic examinations. CONCLUSIONS: Idiopathic clubfeet with preserved hindfoot pronation have a better long-term prognosis. Preservation of functional mobility of the subtalar joint is a key factor in the treatment of clubfoot deformity.  相似文献   
73.
Enhancing and diminishing gene function in human embryonic stem cells   总被引:7,自引:0,他引:7  
It is widely recognized that gain- and loss-of-function approaches are essential for understanding the functions of specific genes, and such approaches would be particularly valuable in studies involving human embryonic stem (hES) cells. We describe a simple and efficient approach using lipofection to transfect hES cells, which enabled us to generate hES cell lines expressing naturally fluorescent green or red proteins without affecting cell pluripotency. We used these cell lines to establish a means of diminishing gene function using small interfering (si)RNAs, which were effective at knocking down gene expression in hES cells. We then demonstrated that stable expression of siRNA could knock down the expression of endogenous genes. Application of these gain- and loss-of-function approaches should have widespread use, not only in revealing the developmental roles of specific human genes, but also for their utility in modulating differentiation.  相似文献   
74.
The purpose of the study was to investigate whether the reported increased cardiovascular disease risk in shift workers could be explained by changes in cardiovascular risk factors. In a cohort of 239 shift and 157 daytime workers, 1-year changes in biological and lifestyle cardiovascular risk factors were monitored between the start of a new job and 1 year later. Both body mass index and low-density lipoprotein/high-density lipoprotein cholesterol ratio decreased significantly in shift workers compared with daytime workers (body mass index change: -0.31 and +0.13 kg/m; low-density lipoprotein/high-density lipoprotein ratio change: -0.33 and -0.13 respectively). Cigarettes smoked per day increased significantly in shift compared with daytime workers (+1.42 and -1.03, respectively). Therefore, only for smoking, an unfavorable change was observed. This may explain, at most, only a part of the excess cardiovascular disease risk reported in shift workers.  相似文献   
75.
In amphibians, thyrotropin-releasing hormone (TRH) is a potent stimulator of alpha-melanotropin (alpha-MSH) secretion, so TRH plays a major role in the neuroendocrine regulation of skin-color adaptation. We have recently cloned a third type of TRH receptor in Xenopus laevis (xTRHR3) that has not yet been characterized in any other vertebrate species. In the present study, we have examined the distribution of the mRNAs encoding proTRH and the three receptor subtypes (xTRHR1, xTRHR2, and xTRHR3) in the frog CNS and pituitary, and we have investigated the effect of background color adaptation on the expression of these mRNAs. A good correlation was generally observed between the expression patterns of proTRH and xTRHR mRNAs. xTRHRs, including the novel receptor subtype xTRHR3, were widely expressed in the telencephalon and diencephalon, where two or even three xTRHR mRNAs were often simultaneously observed within the same brain structures. In the pituitary, xTRHR2 was expressed selectively in the distal lobe, and xTRHR3 was found exclusively in the intermediate lobe. Adaptation of frog skin to background illumination had no effect on the expression of proTRH and xTRHRs in the brain. In contrast, adaptation of the animals to a white background provoked an 18-fold increase in xTRHR3 mRNA concentration in the intermediate lobe of the pituitary. These data demonstrate that, in amphibians, the effect of TRH on alpha-MSH secretion is mediated through the novel receptor subtype xTRHR3.  相似文献   
76.
BACKGROUND: A remaining leiomyoma, an uncommon postoperative complication of vaginal hysterectomy for symptomatic leiomyomas, occurred. CASE: A second vaginal operation for a remaining leiomyoma was necessary 1 month after a vaginal hysterectomy for a myomatous uterus. CONCLUSION: Checking the pelvic cavity during hysterectomy may avoid this complication.  相似文献   
77.
Hemorrhage risk during operative hysteroscopy   总被引:3,自引:0,他引:3  
BACKGROUND: To evaluate the risk of hemorrhage during hysteroscopic surgery. METHODS: Cases of hemorrhage during hysteroscopic surgery were assessed in a single center, observational, prospective study conducted from 1990 to 2000, including 2116 surgical hysteroscopies. Risk of hemorrhage was evaluated according to the hysteroscopic procedure. The management of this complication was also noted. RESULTS: Thirteen cases (0.61%) were reported. In six cases, hemorrhage stopped spontaneously. For six patients, a Foley (no. 10) probe was introduced into the uterine cavity and inflated for 24 h to stop hemorrhage. For one patient, immediately from the start of the procedure, the uterine arteries were ligatured through the vaginal route in order to stop bleeding. Haemorrhage risk was higher during hysteroscopic adhesiolysis compared with endometrial ablation (Relative risk [RR] 5.22 (1.26-21.64); p = 0.02), polyp [RR 5.3 (1.04-27.09); p = 0.04], and fibroid resections [RR 6.55 (1.58-27.17); p = 0.01]. Haemorrhage risk was however, comparable for endometrial ablation, uterus septa section, polyp, and fibroid resections (p = 0.92). CONCLUSIONS: Hemorrhage risk is higher during synechiolysis compared with other procedures. An inflated Foley probe may be an efficient means of stopping hemorrhage.  相似文献   
78.
This prospective study of 12,140 employees examined the effects of work characteristics and situational, psychological, and health aspects on job mobility. Before job change, the mobility group reported significantly more conflicts with the supervisor, higher physical and emotional strain, higher degree of job insecurity, lower job satisfaction, and lower degree of commitment compared with employees who did not change jobs. After job change, the mobility group reported improved autonomy, task diversity, decreased occurrence of conflicts with the supervisor, decreased physical and emotional strain, and improved training possibilities and job security than before the change. Changing jobs had a positive effect on employees with respect to job perception and job satisfaction and led to reduced fatigue and need for recovery.  相似文献   
79.
80.
We have recently shown that hydroxysteroid sulfotransferase (HST), the enzyme responsible for the biosynthesis of pregnenolone sulfate (Delta(5)PS) and dehydroepiandrosterone sulfate (DHEAS), is expressed in neurons located in the anterior preoptic area and the dorsal magnocellular nucleus of the frog diencephalon. As these two nuclei are richly innervated by NPY-immunoreactive fibers, we investigated the possible implication of NPY in the control of Delta(5)PS and DHEAS biosynthesis. Double labeling of frog brain sections revealed that 42% of the HST-immunoreactive perikarya in the diencephalon were contacted by NPY-containing fibers. In situ hybridization studies showed that Y(1) and Y(5) receptor mRNAs are expressed in the anterior preoptic area and the dorsal magnocellular nucleus. Pulse-chase experiments with (35)S-labeled 3'-phosphoadenosine 5'-phosphosulfate as a sulfate donor demonstrated that frog NPY (fNPY) inhibited the conversion of [(3)H]Delta(5)P and [(3)H]dehydroepiandrosterone ([(3)H]DHEA) into [(3)H,(35)S]Delta(5)PS and [(3)H,(35)S]DHEAS by diencephalic explants. The inhibitory effect of fNPY on Delta(5)PS and DHEAS formation was mimicked by (pPYY) and [Leu(31),Pro(34)]pNPY, which is an agonist for non-Y(2) receptors in mammals, and was completely suppressed by the Y(1) receptor antagonist BIBP3226. Conversely, the Y(2) receptor agonist pNPY-(13-36) and the Y(5) receptor agonist [D-Trp(32)]pNPY did not significantly modify the biosynthesis of [(3)H,(35)S]Delta(5)PS and [(3)H,(35)S]DHEAS. The present study provides the first evidence for the innervation of neurosteroid-producing neurons by NPY fibers. Our data also demonstrate that NPY, acting via Y(1) receptors, exerts an inhibitory effect on the biosynthesis of sulfated neurosteroids.  相似文献   
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