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T. M. Skerry M.D. M.R.C.V.S. R. Suswillo A. J. El Haj N. N. Ali R. A. Dodds L. E. Lanyon 《Calcified tissue international》1990,46(5):318-326
Summary Previous studies of Alcian blue-induced birefringence in adult avian cortical bone showed that a short period of intermittent
loading rapidly produces an increased level of orientation of proteoglycans within the bone tissue. In the absence of further
loading, this persists for over 24 hours. We have proposed that this phenomenon could provide a means for “capturing” the
effects of transient strains, and so provide a persistent, constantly updated strain-related influence on osteocyte populations
related to the bones' averaged recent strain history, in effect, a “strain memory” in bone tissue. In our present study, we
use the Alcian blue-induced birefringence technique to demonstrate that proteoglycan orientation also occurs after intermittent
loading of both cortical and cancellous mammalian bonein vivo andin vitro. We also show that the change in birefringence is proportional to the magnitude of the applied strain, and that the reorientation
occurs rapidly, reaching a maximal value after only 50 loading cycles. Examination of electron micrographs of bone tissue
after staining with cupromeronic blue allows direct visualization and quantification of the change in proteoglycan orientation
produced by loading. This shows that intermittent loading is associated with a realignment of the proteoglycan protein cores,
bringing them some 5 degrees closer to the direction of collagen fibrils in the bone matrix. 相似文献
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Cyclodextrin formulation of dorzolamide and its distribution in the eye after topical administration. 总被引:2,自引:0,他引:2
Hakon H Sigurdsson Einar Stefánsson Elínborg Gudmundsdóttir Thór Eysteinsson Margrét Thorsteinsdóttir Thorsteinn Loftsson 《Journal of controlled release》2005,102(1):255-262
Due to limited aqueous solubility of dorzolamide at physiologic pH, the pH of Trusopt eye drops (cont. 2% dorzolamide) has to be kept at about 5.65, and to increase the topical bioavailability of the drug from Trusopt the contact time of the drug with the eye surface is increased by increasing the viscosity of the eye drops to 100 cps. This low pH and high viscosity can lead to local irritation. In this study, dorzolamide hydrochloride was formulated as 2% and 4% low viscosity solutions (viscosity 3 to 5 cps) containing randomly methylated beta-cyclodextrin at pH 7.45. These formulations were evaluated in rabbits. The animals were sacrificed at various time points after topical administration of the drug and the dorzolamide concentration determined in the different parts of the eye. Trusopt was used as a reference standard. The topical availability of dorzolamide from the cyclodextrin-containing eye drops appeared to be comparable to that from Trusopt and the drug reached retina and optic nerve to give measurable concentrations for at least 8 h after administration of the eye drops. 相似文献
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Youness El harrech Hassan Jira Jaouad Chafiki Mohamed Ghadouane Ahmed Ameur Mohamed Abbar 《Actas urologicas espa?olas》2009,33(1):93-96
Nutcracker syndrome is caused by compression of the left renal vein between the aorta and the superior mesenteric artery where it passes in the fork formed at the bifurcation of these arteries. The phenomenon results in left renal venous hypertension. The syndrome is manifested by left flank and abdominal pain, with or without unilateral haematuria. The nutcracker syndrome has been treated in various ways. We report one case of the syndrome and discuss the place of surveillance in its management. 相似文献
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Hisham Abdel Ghani Ahmed El-Naggar Mohamad Hegazy Atef Hanna Yehia Tarraf Samia Temtamy 《Journal of children's orthopaedics》2007,1(5):313-322
Purpose Congenital clasped thumb is a deformity that is associated with heterogeneous congenital anomalies and it has been addressed
in many congenital syndromes. The aim of this study was to diagnose and evaluate cases of clasped thumb as regards the associated
congenital anomalies and syndromes, and evaluation of the results of treatment of such cases.
Methods A prospective study on 40 patients with 73 clasped thumbs was done. All the patients’ data regarding their personal, family,
pregnancy and developmental histories were recorded. All the patients were exposed to thorough clinical and radiological examination
and genetic assessment. The cases were classified using the Tsuyuguchi et al. (J Hand Surg [Am] 10:613–618, 1985) classification into three types. Conservative treatment was adopted in ten hands, and surgical treatment was performed for
28 hands in 17 patients, with an average follow-up of 26 months.
Results Positive consanguinity was recorded in 57.5% of cases. Associated anomalies were recorded in 77.5% of cases. Type I was the
most common one, followed by type III and then type II. Conservative treatment is effective in type I cases when presented
early, and all patients were satisfied with the results of surgical treatment.
Conclusions We reported associated anomalies which are to our knowledge have not mentioned before in the literature which include; congenital
blindness, radial deviation of the index finger and ventricular septal defect. We found that 68% of the patients had associated
syndromes, and this has not been mentioned before. In this study, we found that there were no difference between type II and
type III clasped thumb as regards the pathological findings, severity, the operative procedures, the treatment protocol and
the operative results. Properly planned treatment gives satisfactory results. 相似文献
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F Reichenberger R Voswinckel B Enke M Rutsch E El Fechtali T Schmehl H Olschewski R Schermuly N Weissmann H A Ghofrani F Grimminger E Mayer W Seeger 《The European respiratory journal》2007,30(5):922-927
For chronic thromboembolic pulmonary hypertension not amenable to pulmonary endarterectomy, effective medical therapy is desired. In an open-label uncontrolled clinical trial, 104 patients (mean +/- sem age 62 +/- 11 yrs) with inoperable chronic thromboembolic pulmonary hypertension were treated with 50 mg sildenafil t.i.d. At baseline, patients had severe pulmonary hypertension (pulmonary vascular resistance 863 +/- 38 dyn.s.cm(-5)) and a 6-min walking distance of 310 +/- 11 m. Eight patients were in World Health Organization functional class II, 76 in class III and 20 in class IV. After 3 months' treatment, there was significant haemodynamic improvement, with reduction of pulmonary vascular resistance to 759 +/- 62 dyn.s.cm(-5). The 6-min walking distance increased significantly to 361 +/- 15 m after 3 months' treatment, and to 366 +/- 18 m after 12 months' treatment. A subset of 67 patients received a single dose of 50 mg sildenafil during initial right heart catheterisation. The acute haemodynamic effect of this was not predictive of long-term outcome. In this large series of patients with inoperable chronic thromboembolic pulmonary hypertension, open-label treatment with sildenafil led to significant long-term functional improvement. The acute effect of sildenafil may not predict the long-term outcome of therapy. 相似文献