摘要:

An experimental model in rats for comparison of bone repair under normal and pathological conditions is described. The low cost of rats and the simple surgical procedure used allow large-scale studies. Although clinical implications must be interpreted with care, our model may prove useful in the attempt to understand how various drugs and metabolic disorders may affect bone healing. We used porous fiber titanium implants to replace a segment of the right proximal tibia in rats. The void space to be filled with bone represented a known and constant volume allowing a direct comparison between differently treated groups. Selected parameters for bone ingrowth could be expressed in terms of growth curves as a function of time, using a mathematical equation for restricted growth. The following parameters for quantity and quality of the ingrown bone were monitored: micromoles calcium as parameter for amount; calcium/hydroxyproline molar ratio for extent of mineralization; calcium/phosphorus molar ratio for maturity of minerals; and ultimate bending stress for strength of the bone-implant interface. With this model we have studied the effect that cis-platinum, an anticancer drug that is used in the treatment of osteogenic sarcoma, has on bone repair.

ISSN:0894-1939    

DOI:10.3109/08941938909018270

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

The physiochemical and healing characteristics of the Plasma-TFE synthetic artery (Atrium Medical Corp. Amherst, NH) were studied and compared to u similarly constructed polyethylene terephthalate graft without Plasma-TFE treatment. Plasma-TFE treatment is a method of coating a graft's surface with tetrafluoroethylene and was found to alter significantly the surface chemistry and energy of the graft. However. Result, of this study suggested that Plasma-TFE treatment had on effect on tissue penetration and neointima formation after implantation into the abdominal aorta of the dog for 8 weeks.

ISSN:0894-1939    

DOI:10.3109/08941938909018271

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Recent in vitro studies on isolated coronary and mesenteric arteries have shown that hyperlipidemia appears to hypersensitize the vascular arterial smooth muscle to drugs such as ergonovine and that this increased contractility seems to be mediated by a serotinergic mechanism. This results in vasospasm with exposure to certain vasoactive drugs such as serotonin or norepinephrine. However, in vivo quantification of this observed phenomenon has not been done. In the present study we used Watanabe hereditary hyperlipidemic (WHHL) rabbits (cholesterol level 459±216 mg/dL) and the normal lipidemic New Zealand white (NZW) rabbit (cholesterol level 35±19) as a control in the study of hyperlipidemia and blood flow changes in response to various vasoactive drugs. Blood flow measurements were made by the video dilution technique (VDT) following catheterization of the superior mesenteric artery. The serotinergic vasoactive drug ergonovine maleate was injected into the superior mesenteric artery at low dose (0.002 mg/kg) and high dose (0.004 mg/kg). A significant decrease (p<. 05) in blood flow was observed in response to high-dose ergonovine maleate in WHHL rabbits compared to the NZW rabbits. This in vivo experiment confirms the in vitro studies showing that hyperlipidemia sensitizes mesenteric arteries in the presence of serotinergic stimuli. The vasodilators verapamil hydrochloride and calcitonin gene-related peptide (CGRP) injected into the superior mesenteric artery caused a marked increase in flow in both the WHHL and the normal lipidemic NZW rabbits. This model can be used in the assessment of superior mesenteric artery ischemia and its reversal.

ISSN:0894-1939    

DOI:10.3109/08941938909018272

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

A device allowing pressure to be applied to a local skin site where the skin blood flow is followed using laser Doppler flowmetry is described. The blood flow was studied on the buck of the hand in eight volunteers before and during brachial arterial occlusion and while the external pressure was increased step by step. The flowmetry value during arterial occlusion was 0.3±0.1 AU. and when the external pressure was increased to 120 mm Hg the values was similar (p =. 44). The shin perfusion pressure, defined as the least external pressure needed to achieve flow cessation, was found to be 92±16 mm Hg (range 70–111 mm Hg), and the mean arterial pressure was 90±9 mm Hg (NS). The skin perfusion value is in agreement with that found by others using other techniques for measuring blood flow and a circumferent cuff for applying pressure.

ISSN:0894-1939    

DOI:10.3109/08941938909018273

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

In experiments with dogs (n = 610), the influence of temperature, flow rate, perfusate, and perfusion duration on the hind leg subjected to an isolation perfusion ads studied. The perfusion pressure, the blood gases, and the metabolic status in specimens of skeletal muscle obtained at the end of the perfusion period served us parameters. A perfusion of 1 and 2 h with whole blood, a flow rate of 10 mL/100 g/min, rind temperatures of up to 42°C did not result in alterations of the energy metabolism. When the flow rate was lowered to 5 mL/100 g/min, when other perfusates were used, or when the im temperature was raised to 43.5°C, then tissue damage occurred Knowledge gained in these. Extremities was utilized in the treatment of 371 patients with malignancies of the extremities, and an extremely low complication rate was observed.

ISSN:0894-1939    

DOI:10.3109/08941938909018274

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

ISSN:0894-1939    

DOI:10.3109/08941938909018275

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor