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991.
VR Lord JW Cherwonogrodzky GG Schurig RD Lord MJ Marcano GE Meléndez 《Canadian Metallurgical Quarterly》1998,59(5):546-551
We have investigated the inter-relationship between the opioid and aminergic systems in the control of secretion of the pro-oestrous LH surge and the involvement of delta-opioid receptor subtypes in this process. Conscious female rats bearing a cannula in the femoral artery were injected i.p. with a selective delta-opioid receptor agonist (DPDPE) either alone or with the opioid antagonist (naloxone) at 1300 h on the day of pro-oestrus. Blood samples were collected hourly between 1500 h and 1900 h, and plasma LH levels were measured by RIA. At the end of this period (1900 h), the animals were autopsied and the concentrations of the amines (noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5HT)) and their metabolites (dihydroxyphenolglycol (DHPG) and 5-hydroxyindoleacetic acid (5HIAA), metabolites of NA and 5HT respectively) were determined by HPLC with electrochemical detection in the medial preoptic area, suprachiasmatic nucleus, median eminence and arcuate nucleus. DPDPE abolished the LH surge and concomitantly decreased hypothalamic NA and DHPG concentrations in all the areas examined. The levels of DA, 5HT and 5HIAA were also reduced in all hypothalamic regions studied, except DA and 5HIAA in the suprachiasmatic nucleus. Naloxone reversed these inhibitory effects of the delta-agonist. We conclude that activation of delta-opioid receptors may exert an inhibitory effect on LH release. The effect is probably an indirect one mediated by the monoaminergic systems, as they are suppressed by DPDPE in nearly all the hypothalamic regions studied. 相似文献
992.
High-resolution spectroscopy of Mars' atmosphere with the Hubble Space Telescope revealed the deuterium Lyman alpha line at an intensity of 23 +/- 6 rayleighs. This measured intensity corresponds to HD/H2 = 1.5 +/- 0.6 x 10(-4), which is smaller by a factor of 11 than HDO/H2O. This indicates that fractionation of HD/H2 relative to that of HDO/H2O is not kinetically controlled by the rates of formation and destruction of H2 and HD but is thermodynamically controlled by the isotope exchange HD + H2O left and right arrow HDO + H2. Molecular hydrogen is strongly depleted in deuterium relative to water on Mars because of the very long lifetime of H2 (1200 years). The derived isotope fractionation corresponds to an estimate of a planetwide reservoir of water ice about 5 meters thick that is exchangeable with the atmosphere. 相似文献
993.
CONTEXT: Oral contraceptive users' risk of accidental pregnancy may be higher than it should be, because of inconsistent pill-taking. However, few reliable data are available on pill users' everyday experiences with their method, especially characteristics that may affect consistency of use. METHODS: Two months after initiating or resuming oral contraceptive use, a nationwide sample of 943 women completed questionnaires examining their compliance with instructions for proper use, the quality of their interactions with their provider, their satisfaction with the method, and the frequency and costs of visits or calls to their providers because of pill-related side effects. Regression analyses were used to determine the factors associated with compliance difficulties and method dissatisfaction. RESULTS: In all, 47% of users missed one or more pills per cycle, and 22% missed two or more. Women who lacked an established pill-taking routine, who did not read and understand all of the informational material accompanying the pill package, or who experienced spotting or heavy bleeding had increased odds of missing two or more pills per cycle. Method satisfaction was most likely among women who were aware of the pill's noncontraceptive benefits, were satisfied with their relationship with their provider, had used the pill in the past and experienced few side effects. Some 22% of users called their provider at least once about pill-related side effects, and 9% made at least one visit for this reason; these women spent $25 and $62, respectively, to treat side effects. CONCLUSIONS: Improving pill use is a shared responsibility of the provider, the patient and, to a lesser degree, pill manufacturers. Awareness of potential difficulties such as inadequate counseling is a key step in helping women use oral contraceptives effectively. 相似文献
994.
Four samples each of clear and lightly (thin), moderately, and heavily (thick) meconium-stained amniotic fluid were divided in two portions and submitted twice for assessment to 20 midwives (a total of 320 case assessments). None of the midwives completely agreed with the standard assessment for more than 85 percent of the cases. When disregarding clear samples, for which there was good agreement, each of the midwives classified on average only 35.8 percent of the meconium-stained samples in the same category on each of the four occasions that they were presented to them. Calculation of kappa statistics, which express proportional agreement corrected for chance, indicated that none of the midwives showed very good agreement (kappa > 0.81) with the standard and that fewer than 10 percent showed very good agreement with themselves. The data indicate that grading the severity of meconium staining by visual assessment has such poor accuracy and precision that it cannot provide a valid basis for assigning different care policies to different degrees of meconium staining. 相似文献
995.
Our experience with developing and implementing the outpatient component of an evidence-based disease management initiative has been a positive one. Involvement of respected practicing physicians in the planning phase, recommendation of evidence-based guidelines, and the supportive relationship between the hospital and participating practices have been essential to the successful launching of an asthma disease management program by a children's healthcare system. As the implementation phase continues to progress, we are preparing for the 6 month data collection stage, including outcomes measurement and practice pattern feedback. After 1 year of implementation we will analyze the data and report on the effects of the Partnership. We expect that physicians will continue to use the guidelines, and therefore sustain the improved health status of children with asthma. We will continue to invite pediatricians' participation in the Partnership so that more children in our community can benefit from high-quality cost-effective care that results in superior health outcomes. 相似文献
996.
SA Eisen N Lin MJ Lyons JF Scherrer K Griffith WR True J Goldberg MT Tsuang 《Canadian Metallurgical Quarterly》1998,93(9):1375-1384
BACKGROUND: Pathological gambling is becoming an increasing problem in the United States as the number of legalized gambling establishments grows. To examine vulnerability to pathological gambling, we estimated the familial contributions (i.e. inherited factors and/or experiences shared by twin siblings during childhood) to DSM-III-R pathological gambling symptoms and disorder. METHODS: Data were obtained from a telephone interview performed in 1991-92 utilizing the Diagnostic Interview Schedule Version III-Revised. Interviews were administered to 6718 members of the nationally distributed Vietnam Era Twin Registry of male-male monozygotic and dizygotic twin pairs who served in the military during the Vietnam era. RESULTS: Inherited factors explain between 35% (95% CI: 28%, 42%) and 54% (95% CI: 39%, 67%) of the liability for the five individual symptoms of pathological gambling behavior that could be estimated statistically. In addition, familial factors explain 56% (95% CI: 36%, 71%) of the report of three or more symptoms of pathological gambling and 62% (95% CI: 40%, 79%) of the diagnosis of pathological gambling disorder (four or more symptoms). CONCLUSIONS: Familial factors have an important influence on risk for pathological gambling behavior. The increasing access to legalized gambling is likely to result in a higher prevalence of pathological gambling behavior among individuals who are more vulnerable because of familial factors. 相似文献
997.
JS Cacciola MJ Rutherford AI Alterman JR McKay FD Mulvaney 《Canadian Metallurgical Quarterly》1998,12(4):332-337
Continuous wave Doppler methods have been widely used clinically for evaluating the severity of aortic regurgitation; however, there have been no studies comparing these continuous wave Doppler methods with a strictly quantifiable reference for regurgitant severity. The purpose of this study was to test the applicability of continuous wave Doppler methods (deceleration slope and pressure half-time) for evaluation of chronic aortic regurgitation in an animal model. Eight sheep were studied 8 to 20 weeks after surgery to create chronic aortic regurgitation. Twenty-nine hemodynamically different states were obtained pharmacologically. A Vingmed 775 system was used for recording continuous wave Doppler traces with a 5 MHz annular array transducer directly placed on the heart near the apex. The aortic regurgitation was quantified as peak and mean regurgitant flow rates, regurgitant stroke volumes and regurgitant fractions determined with pulmonary and aortic electromagnetic flow probes and meters balanced against each other. Peak regurgitant flow rates varied from 1.8 to 13.6 L/min (6.3 +/- 3.2 L/min) (mean +/- SD), mean regurgitant flow rates varied from 0.7 to 4.9 L/min (2.7 +/- 1.3 L/min), regurgitant stroke volume varied from 7.0 to 48.0 ml/beat (26.9 +/- 12.2 ml/beat), and regurgitant fraction varied from 23% to 78% (53% +/- 16%). Only marginal correlations were obtained between reference indexes and continuous wave Doppler deceleration slope and pressure half-time (r = 0.55 to 0.74). A deceleration slope greater than 3 m/sec2 and pressure half-time less than 400 msec did, however, provide 100% specificity for detecting severe AR (regurgitant fraction > 50%). Our study shows that the continuous wave Doppler deceleration slope and pressure half-time methods have limited use for quantifying aortic regurgitation. 相似文献
998.
PA Wabnitz H Walters MJ Tyler JC Wallace JH Bowie 《Canadian Metallurgical Quarterly》1998,52(6):477-481
We treated a 73-year-old man with a dural arteriovenous fistula (AVF) with cortical venous drainage of the left mastoid region using transarterial embolization of the middle meningeal and occipital arteries with n-butyl 2-cyanoacrylate (NBCA). The patient's clinical symptoms improved dramatically. Three months after the procedure, follow-up CT showed resolution of white matter edema and follow-up angiograms showed no evidence of a recurrent AVF. This report indicates that dural AVFs without sinus drainage can be cured solely with transarterial NBCA embolization. 相似文献
999.
JB Gibson RA Reynolds MJ Palmieri GT Berry LJ Elsas HL Levy S Segal 《Canadian Metallurgical Quarterly》1995,44(5):597-604
By limiting galactosylation mechanisms, a cellular deficiency of the uridine sugar nucleotide, UDPgalactose, has been implicated as a cause of the long-term complications seen in patients with classic galactosemia despite dietary treatment. As a result, great interest has been generated in the accurate assessment of UDPgalactose, as well as UDPglucose, from which UDPgalactose may be derived by the function of a ubiquitous, active UDPgalactose-4-epimerase. Since several series of values for the concentration of these compounds in red blood cells (RBCs) of galactosemics have been flawed by the use of methods subsequently shown to be unsuitable, we have quantified erythrocyte UDPgalactose and UDPglucose levels by an accurate high-performance liquid chromatography (HPLC) assay in 116 normals, 76 galactosemics, and 39 patients with other metabolic disorders. These large groups have permitted the evaluation of age, diet, and genotype as influential factors in the steady-state RBC levels of the sugar nucleotides. The data show that age is an important determinant of RBC levels, with children younger than 10 years having higher values than individuals older than 10 years. Mean UDPgalactose levels in galactosemic children younger than 10 years and those older than 10 years were 30% and 18% lower, respectively, than levels in comparable normals. Although the mean differences were highly significant, there was considerable overlap of individual values. There was no difference in UDPglucose levels between galactosemics and normals.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
1000.
Amyotrophic lateral sclerosis (ALS) is characterized neuropathologically by chromatolysis, Bunina bodies, hyaline inclusions, skein-like inclusions and axonal spheroids. Aluminum, a known neurotoxin, is the cause of dialysis encephalopathy and is considered to be a causative agent in high incidence foci of ALS in the western Pacific. We have developed an experimental model of motor neuron degeneration in New Zealand white rabbits using chronic low-dose intracisternal administration of aluminum and compared the clinical and neuropathological changes to those of human ALS. Aluminum-inoculated rabbits developed progressive hyperreflexia, hypertonia, limb splaying, gait impairment, muscle wasting, hindlimb paralysis and impaired tonic immobility responses without overt encephalopathic features over a 14-month period. Examination of spinal cords from these animals demonstrated the frequent occurrence and progressive development of anterior horn cell lesions that included small, round, argentophilic perikaryal inclusions similar to hyaline inclusions seen in human ALS. Other inclusions were more condensed and eosinophilic, while still others had neurofibrillary tangle-like morphologies. Axonal spheroids and neuritic thickenings were also prominent and were identical to those seen in human ALS. We believe that the similar and progressive development of neuropathological changes observed in the chronic aluminum-intoxication model, compared to human ALS, warrants further study to aid in understanding the cellular and molecular mechanisms of human motor neuron disease. 相似文献