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61.
YK Fung MG Mendlik MC Haven MP Akhter DB Kimmel 《Canadian Metallurgical Quarterly》1998,82(5):243-249
Quantitative measurement of sound-induced discomfort and pain thresholds showed that migraineurs (n = 65) were significantly more sensitive than headache-free controls (n = 80), both during and outside attack (p < 0.0001). Patients tested with head pain had lower thresholds than those tested without pain (p < 0.01). Migraine with and without aura did not differ as to sound sensitivity. There were no significant differences in thresholds between the symptomatic and nonsymptomatic sides (p > or = 0.78). Patients with unilateral headache or pain of pulsating character were more sensitive than those with bilateral headache or pressing pain (p < 0.05). Phonophobia did not correlate significantly with duration, frequency, or severity of attacks. The main results were in accordance with a questionnaire study concerning subjective evaluation of sound sensitivity. Similarities between phonophobia and photophobia in migraine provide evidence that both phenomena share a common pathophysiological mechanism in this condition. 相似文献
62.
Many biomolecules are characterized by surfaces containing extended nonpolar regions, and the aggregation and subsequent removal of such surfaces from water is believed to play a critical role in the biomolecular assembly in cells. A better understanding of the hydrophobic hydration of biomolecules may therefore yield new insights into intracellular assembly. Conventional views hold that the hydration shell of small hydrophobic solutes is clathrate-like, characterized by local cage-like hydrogen-bonding structures and a distinct loss in entropy. The hydration of extended nonpolar planar surfaces, however, appears to involve structures that are orientationally inverted relative to clathrate-like hydration shells, with unsatisfied hydrogen bonds that are directed towards the hydrophobic surface. Here we present computer simulations of the interaction between the polypeptide melittin and water that demonstrate that the two different hydration structures also exist near a biomolecular surface. We find that the two structures are distinguished by a substantial difference in the water-water interaction enthalpy, and that their relative contributions depend strongly on the surface topography of the melittin molecule: clathrate-like structures dominate near convex surface patches, whereas the hydration shell near flat surfaces fluctuates between clathrate-like and less-ordered or inverted structures. The strong influence of surface topography on the structure and free energy of hydrophobic hydration is likely to hold in general, and will be particularly important for the many biomolecules whose surfaces contain convex patches, deep or shallow concave grooves and roughly planar areas. 相似文献
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64.
We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from the 1970 census from the National Bureau of Statistics in Denmark, which has data on occupational status for 1,768,846 men between 15 and 74 years of age. From this census, we ascertained a group of 124,766 "solvent-exposed" men and an "unexposed" group of 87,501 male electricians, bricklayers, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis. 相似文献
65.
BACKGROUND: In dealing with displaced proximal humerus fractures, there is still much controversy in treatment modalities. The latest investigations emphasize the concept of minimal exposure and rigid fixation. METHODS: The technique of closed reduction and percutaneous fixation with cannulated screws and k-pins was performed on 19 patients with two- and three-part proximal humerus fractures. The outcomes were evaluated with a mean follow-up of 21 months. RESULTS: All except one case had a solid union of the fracture. Sixteen of 19 patients (84%) acquired good or excellent results according to Neer's classification. No further collapse or avascular necrosis was found. CONCLUSION: The method of closed reduction and percutaneous fixation, although technically demanding, yields satisfactory results in displaced proximal humerus fracture. Cannulated screws provided rigid fixation that was the underlying tenet for early functional retrieval. 相似文献
66.
Mycobacterium szulgai is a rare cause of human infections, and when present it is mostly known to cause lung infection. We report the first case of isolated Mycobacterium szulgai osteomyelitis in a 68-year-old woman on chronic immunosuppressive therapy. Review of the literature revealed a total of three other cases of M. szulgai osteomyelitis. In all these cases there was evidence of hematogenous or contiguous spread, including one with extensive dissemination. Pulmonary M. szulgai infections tend to occur in patients with chronic lung disease and/or concomitant lung infections, whereas osteomyelitis tends to occur in patients who have severe immunosuppression secondary to disease or drugs. 相似文献
67.
Dobutamine-induced hypotension has been disregarded as a marker of more severe functional abnormalities in patients with suspected coronary artery disease. However, its functional significance in patients with myocardial infarction has not been studied. The aim of this study was to define the predictors of systolic blood pressure (SBP) response to dobutamine in patients with previous myocardial infarction. Dobutamine stress (up to 40 microg/kg per minute) echocardiography was performed in 326 patients with prior myocardial infarction referred for evaluation of myocardial ischemia. A 16-segment, four-grade score model was used to assess left ventricular function. Wall motion score index was derived by summation of wall motion score divided by 16. SBP and heart rate increased from rest to peak dobutamine stress (127 +/- 22 vs 134 +/- 27 mm Hg and 72 +/- 14 vs 122 +/- 24 bpm, p < 0.00001 in both). An increase of SBP > or = 30 mm Hg occurred in 50 patients (15%). By multivariate analysis, independent predictors of failure of SBP increase were higher peak wall motion score index (p < 0.001), higher resting SBP (p < 0.01), and medication with calcium channel blockers (p < 0.05). SBP drop > or = 20 mm Hg occurred in 54 patients (17%). Independent predictors of SBP drop were higher resting wall motion score index (p < 0.001), higher resting SBP (p < 0.0001), and older age (p < 0.05). In patients with myocardial infarction, left ventricular function and baseline systolic blood pressure are powerful predictors of SBP response to dobutamine stress testing. 相似文献
68.
The selection of NIH 3T3 cells expressing a hydroxytamoxifen-inducible c-Raf-1-estrogen receptor fusion protein (c-Raf-1-BxB-ER) in the absence or presence of the inducer results in dramatic differences in the expression levels of the fusion protein. Hydroxytamoxifen-mediated constitutive activation of the Raf signal favors the selection of cells expressing low levels of c-Raf-1-BxB-ER. Cells selected in the absence of hydroxytamoxifen express up to 20 times higher levels of the inducible Raf kinase. Activation of the oncogenic Raf kinase in cells expressing low levels leads to a weak activation of the Raf/Mek/Erk cascade and the induction of S phase in confluent cells. The activation of cells expressing high levels of the kinase leads to a strong persistent signal and inhibits DNA synthesis and mitosis in proliferating cells. The inhibition of DNA synthesis and cell division is presumably due to the elevated expression of the cyclin-dependent kinase inhibitor p21cip1, similar to cells exposed to ionizing radiation. Despite the inhibition of DNA synthesis and mitosis, the constitutive activity of the Raf signaling pathway is still able to initiate cell growth. Activation of the high-intensity Raf signal in arrested serum-starved cells induces cell growth up to a size corresponding to that of M-phase cells in the absence of DNA synthesis. High-intensity Raf signals in proliferating cells consistently lead to an accumulation of cells with the size of M-phase cells and the DNA content of G1 cells or G2-M-phase cells. Therefore, the activation of Raf kinase is sufficient to drive cell growth, even in the presence of high levels of the cyclin-dependent kinase inhibitor p21cip1. 相似文献
69.
RK Dhiman AK Seth S Jain YK Chawla JB Dilawari 《Canadian Metallurgical Quarterly》1998,43(6):1311-1316
Results of eight multicenter, randomized, placebo-controlled, double-blind, parallel-group studies were pooled to assess the efficacy of the angiotensin II-receptor blocker irbesartan over the dose range of 1 to 900 mg. A total of 2955 adults with a seated diastolic blood pressure of 95 to 110 mm Hg were randomized to treatment with oral irbesartan once daily or placebo for 6 to 8 weeks. Office blood pressure was measured at trough (24+/-3 hours after the last dose) and peak (3+/-1 hours after the last dose) by mercury sphygmomanometry. Demographic characteristics (mean blood pressure; 151/101 mm Hg; mean age, 54 years; 63% male; and 82% white) were similar across all dose groups. After the groups were pooled, antihypertensive efficacy was assessed by therapeutic response (trough seated diastolic blood pressure <90 mm Hg or a reduction from baseline of > or = 10 mm Hg) and by modeling of the maximum reductions in trough and peak seated diastolic and systolic blood pressure. Antihypertensive effects increased with increasing doses and reached a plateau at > or = 300 mg. Irbesartan 150 mg provided placebo-subtracted reductions in trough seated systolic and diastolic blood pressure of approximately 8 and approximately 5 mm Hg, respectively, with 56% of patients displaying a favorable response. In conclusion, irbesartan provides clinically significant blood pressure lowering, with a clear relationship between (log) dose and antihypertensive effect. 相似文献
70.
PP Chen YK Weaver DL Budenz WJ Feuer RK Parrish 《Canadian Metallurgical Quarterly》1998,105(10):1928-1935
OBJECTIVE: To examine the effect of cataract extraction (CE) after trabeculectomy on intraocular pressure (IOP) control. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: A total of 115 consecutive patients who underwent extracapsular CE (N = 58) or phacoemulsification (N = 57) with intraocular lens (IOL) placement after trabeculectomy were studied. INTERVENTION: Cataract extraction with IOL after trabeculectomy was performed. MAIN OUTCOME MEASURES: Preoperative, intraoperative, and postoperative factors were evaluated for association with loss of IOP control requiring additional medications, bleb needling, or further glaucoma surgery, using Kaplan-Meier survival analysis and Cox multivariate proportional hazards survival regression. RESULTS: After mean postoperative follow-up of 21.1 +/- 14.3 months, additional glaucoma medication or needling of the filtering bleb to maintain IOP control was required in 35 eyes (30.4%) and was significantly associated with intraoperative iris manipulation and early postoperative peak IOP greater than 25 mmHg. Additional glaucoma surgery was eventually required in 11 eyes (9.6%) and was significantly associated with age of 50 years or younger, preoperative IOP greater than 10 mmHg, and early postoperative peak IOP greater than 25 mmHg. The cumulative proportion of patients who did not require reoperation for glaucoma was 93% and 90% at 1 and 2 years, respectively. The mean IOP at last visit had increased 1.6 mmHg above the pre-CE level and did not vary significantly after the first postoperative month. The median interval from CE to the addition of glaucoma medication or bleb needling was 1.6 months (within 3 months in 20 of 33 eyes) and that from nonsurgical intervention to further glaucoma surgery was 3.6 months (before the 7th postoperative month in 6 of 11 eyes). Of 19 eyes with hypotony (IOP < or = 6 mmHg) before CE, 11 eyes remained hypotonous after CE despite an increase in the mean IOP from 4.6 to 7.5 mmHg. CONCLUSIONS: When CE is performed after trabeculectomy, age of 50 years or younger, preoperative IOP greater than 10 mmHg, intraoperative iris manipulation, and early postoperative IOP greater than 25 mmHg are associated with worsened postoperative IOP control. Most bleb failures occur soon after CE. Resolution of pre-existing hypotony after CE is unpredictable. 相似文献