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Biomedical subjects

R B Rutherford

Publications and source records attributed to R B Rutherford.

At least 19 recordsLinked to original sources
PubMed1992

Synergistic effects of dexamethasone on platelet-derived growth factor mitogenesis in vitro.

Platelet-derived growth factor (PDGF) and insulin-like growth factor-I (IGF-I) interact to stimulate proliferation of fibroblasts in culture. Glucocorticoids variably effect the response of cultured fibroblasts to polypeptide growth factors. This study determined the effects of dexamethasone on growth-factor stimulation of gingival, periodontal ligament and pulp fibroblast proliferation in vitro. Cultures of quiescent, low-passage, human fibroblasts were treated for varying periods of time with transforming growth factor-beta 2 (TGF-beta 2), PDGF and IGF-I: (1) alone, (2) in combination with each other, (3) singly plus dexamethasone, (4) in combination plus dexamethasone. Combinations of human, recombinant PDGF and IGF-I (10-1000 ng/ml) induced significantly higher rates of cell proliferation than either factor alone. Dexamethasone at doses ranging from 10(-5) to 10(-8) M substantially enhanced cell proliferation induced by these combinations and by PDGF without IGF-I but not IGF-I alone. By 6 days after a single application, 2-3 times as many cells were present in the PDGF and dexamethasone cultures as compared to PDGF without IGF-I. TGF-beta 2 specifically blocked the effects of dexamethasone added to PDGF-stimulated cells. Collagen and non-collagenous protein synthesis was not affected by the addition of PDGF and IGF-I with or without dexamethasone. These data suggest that dexamethasone may substitute for IGF-I in PDGF stimulation of cell proliferation.

Cell Division↗
PubMed1992

Political issues in endovascular surgery.

"Political issues" may determine the relative progress if not the ultimate success and acceptance of endovascular surgery as much as its intrinsic merits. These issues include turf battles, commercialization of newly developing technologies, unethical advertising, and self-serving reporting practices in presenting clinical results. Acceptable indications, methods of evaluating results, standardized reporting practices, appropriate "gold standards" for comparison, and controlled trials (without premature release) are recommended, as well as an emphasis on the future need for proper training and credentialing and quality assurance programs.

Cost-Benefit Analysis↗
PubMed1992

Platelet-derived and insulin-like growth factors stimulate regeneration of periodontal attachment in monkeys.

Regeneration of cementum, ligament, bone and new attachment was achieved by introducing mixtures of recombinant human platelet-derived growth factor and insulin-like growth factor into debrided lesions of experimentally induced periodontitis in monkeys. This growth factor therapeutic regimen induced the regeneration of nearly 50% of the lost attachment within 4 weeks. New attachment in some cases included regeneration of horizontally resorbed interdental septa. These observations suggest that predictable, clinically significant gains in new attachment may be possible through the use of highly purified human recombinant growth factors delivered to debrided lesions of adult periodontitis in appropriate, inert carrier vehicles.

Alveolar Bone Loss↗
PubMed1992

Use of bovine osteogenic protein to promote rapid osseointegration of endosseous dental implants.

An enriched bovine osteogenic protein preparation in combination with bone collagen matrix (osteogenic protein device) was used to effect new bone growth in extraction sites in the presence or absence of titanium dental implants. Incisor and canine teeth were extracted from each of three cynomolgus monkeys, and implants were inserted directly into the sockets without surgical site preparation. The osteogenic protein device induced new bone formation in close apposition to the titanium implants in all trials within 3 weeks. A lesser amount of new bone formation in both sets of control sites was limited to the bony socket walls and not closely apposed to the implant. These data show that the osteogenic protein device is capable of inducing new bone formation in tooth sockets within 3 weeks in the presence or absence of titanium implants. This is the first known demonstration of the therapeutic induction of bone formation in close apposition to metallic implants.

Animals↗
PubMed1991

Standards for evaluating and reporting the results of surgical and percutaneous therapy for peripheral arterial disease.

By adopting precise definitions of essential terms, developing objective criteria by which the various measures of success or failure can be judged, and establishing a standardized scheme by which severity of disease, degrees of improvement or deterioration, and risk factors that affect outcome can be graded, the quality of published reports of revascularization procedures for lower extremity ischemia can be greatly improved, allowing comparative evaluation of treatment modalities.

Angioplasty, Balloon↗
PubMed1991

Popliteal artery entrapment: findings at MR imaging.

Magnetic resonance (MR) imaging can noninvasively demonstrate the anatomic relationships between the popliteal artery and the muscles within the popliteal fossa, making it an ideal screening test for popliteal artery entrapment prior to angiography or surgery. The authors describe a patient with bilateral type II popliteal artery entrapment in whom the anomaly was diagnosed in the asymptomatic extremity with MR imaging.

Adult↗
PubMed1991

Suggested standards for reporting on arterial aneurysms. Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery.

The literature on arterial aneurysms is subject to potential misinterpretation because of inconsistencies in reporting standards. The joint councils of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery appointed an ad hoc committee to address this issue. This communication, prepared in response to the need for standardized reporting, defines and classifies arterial aneurysms and recommends standards for describing the causes, manifestations, treatment, and outcome criteria that are important when publishing data on aneurysmal disease.

Aneurysm↗
PubMed1991

Standards for evaluating and reporting the results of surgical and percutaneous therapy for peripheral arterial disease.

By adopting precise definitions of essential terms, developing objective criteria by which the various measures of success or failure can be judged, and establishing a standardized scheme by which severity of disease, degrees of improvement or deterioration, and risk factors that affect outcome can be graded, the quality of published reports of revascularization procedures for lower extremity ischemia can be greatly improved, allowing comparative evaluation of treatment modalities.

Arterial Occlusive Diseases↗
PubMed1991

Standards for evaluating results of interventional therapy for peripheral vascular disease.

Uniform standards for evaluating and reporting the results of therapeutic interventions for peripheral vascular disease are clearly needed. They are already established for vascular surgery, as represented by several reports by SVS/ISCVS committees, but they are not always followed by vascular surgeons and have been largely ignored by other vascular interventionists. In this article, the major problematic reporting practices are discussed and illustrated, and 14 recommendations are advanced to deal with them. They are intended to provide precise definitions, objective criteria of success or failure, standardized severity gradation schemes for peripheral vascular disease and its risk factors, and proper procedures for reporting the outcome of all forms of therapeutic intervention. Until these or some other agreed upon reporting standards are accepted and followed, the literature on peripheral vascular disease and its management will continue to be a source of confusion rather than enlightenment.

Angioplasty, Balloon↗
PubMed1991

Factors affecting the patency of small-caliber prostheses: Observations in a suitable canine model.

Lack of an endothelial surface is most often blamed for the relatively poor patency of polytetrafluoroethylene grafts used in infrageniculate bypass when compared to autogenous saphenous vein. Length, caliber, flow, and ability to withstand flexion are also acknowledged but have not been systematically examined. We report the results of our attempts to discriminate between the relative contributions of these factors and to develop a suitable canine model for evaluating small-caliber prostheses (4 mm x 10 cm thin-walled polytetrafluoroethylene). ASA/dipyridamole were given 1 week before and 4 weeks after operation. Patency was assessed by directional Doppler at frequent intervals (less than or equal to 3 days). The following were observed: (1) Iliac placement provided a useful patency reference point (40% to 50% patency at 60 days). (2) Carotid patency was not better than iliac patency. (3) Crossing a flexion crease decreased patency. (4) The low patencies were not technical but intrinsic to the graft. Iliofemoral vein grafts achieved 100% patency at 60 days. (5) External rings did not improve iliofemoral patency (equal in paired comparisons). (6) Neither baseline platelet aggregation nor platelet aggregation after ASA administration correlated with patency. This canine model is an excellent test for small caliber-low flow prostheses. It allows paired-site comparisons, which are essential, and meaningful patency data with reasonable numbers of subjects within 2 months' observation. Directional Doppler evaluation avoids need for angiography or serial postmortem analysis sacrifice.

Anastomosis, Surgical↗
PubMed1991

Peripheral vascular assessment and its role in predicting wound healing potential.

Local perfusion is a critical factor in wound healing with substantially greater perfusion levels necessary to support healing than those required to maintain viable intact tissues. Clinical observations alone are not sufficiently reliable to assess healing potential particularly in the patient with known vascular compromise. This article reviews the more common noninvasive techniques for evaluating peripheral circulation and wound healing potential in the distal lower extremity.

Foot↗
PubMed1991

Spontaneous aorto-left renal vein fistula: the "abdominal pain, hematuria, silent left kidney" syndrome.

Spontaneous aorto-left renal vein fistula (ALRVF) is a rare occurrence; with this case, only 16 have been reported to date. Common features in patients with ALRVF include abdominal pain (81%), hematuria (100%), impaired renal function (85%), and nonvisualization of the left kidney (100%). Less common but also present in the majority of cases are a left sided bruit (73%), pulsatile abdominal mass (63%), and proteinuria (50%). Also important, 94% have a retroaortic left renal vein, unlike the six cases of traumatic ALRVF that have been reported. This magnifies the diagnostic value of contrast abdominal computed tomographic scanning, which demonstrates not only the anomalous location of the left renal vein but also the abdominal aortic aneurysm and poor enhancement of the left kidney. These findings rule out the possibility of the "nutcracker syndrome" (left renal vein compression between aorta and superior mesenteric artery). Although confirming the presence of a fistula by early caval opacification, aortography does not always distinguish ALRVF from the more common aortocaval fistula. This can be accomplished by Duplex scanning with deep probes and even preferably color coding of velocity signals. With such precise preoperative localization, surgical repair is relatively easy and safe.

Abdominal Pain↗
PubMed1991

Inflammatory abdominal aortic aneurysm: an indication for the retroperitoneal approach.

In three recent cases, one of which is described in this report, we have found the retroperitoneal approach to have the following significant and distinct advantages over the transabdominal repair of inflammatory abdominal aortic aneurysms: (1) The posterolateral aspect of the aorta characteristically is not significantly involved by the inflammatory process, whereas the anterior aspect is. (2) The duodenum does not need to be dissected away from the aorta and, in fact, is not seen. (3) The left renal vein moves up off the neck of the aneurysm with forward mobilization of the kidney, facilitating proximal control. Now that the computerized tomography scan has become the preferred preoperative imaging technique for abdominal aortic aneurysms, the diagnosis of inflammatory abdominal aortic aneurysm can routinely be made before elective operation allowing the retroperitoneal approach to be selected.

Aged↗
PubMed1990

Serum endothelin-1 concentrations and cold provocation in primary Raynaud's phenomenon.

To determine whether the vasoconstriction in Raynaud's phenomenon is associated with raised concentrations of the endothelium-derived vasoconstrictor endothelin (ET-1), responses to cold pressor testing were examined in 7 subjects with primary Raynaud's phenomenon and in 7 control subjects. Baseline serum ET-1 levels (pg/ml), as measured by radioimmunoassay, were three times higher in Raynaud's subjects (5.3 [SEM 1.7] pg/ml) than in controls (1.7 [0.3]). With progressive local cooling digital arterial pulsatility, as measured by plethysmography, fell earlier and to a greater extent in Raynaud's subjects than in controls, with a half-maximum decrement in pulsatility occurring at 27 [2.6] degrees C and 18 [0.5] degrees C, respectively. Temperature reduction sufficient to cause loss of pulsatility in the Raynaud's subjects produced increases in ET-1 concentrations in both groups that were greater in Raynaud's (10.3 [4.4] pg/ml) than in control subjects (2.7 [0.9] pg/ml). Serum ET-1 in the contralateral arm rose in parallel to but to a lesser extent than that in the cold-challenged arm. Increases in ET-1 concentrations were temporally related to loss of pulsatility but followed the onset of symptoms. Thus the increased basal and stimulated serum endothelin concentrations in Raynaud's disease are associated with the enhanced, prolonged vasospasm of this disorder.

Adult↗
PubMed1990

Interleukin-1 regulation of procollagenase mRNA and protein in periodontal fibroblasts in vitro.

An in vitro model is used to investigate the hypothesis that activated fibroblasts produce collagenolytic activity in inflammatory sites. Interleukin-1, a cytokine present in the gingiva and crevicular fluid of periodontitis patients, has multiple biologic activities including the ability to stimulate collagenase in dermal and synovial fibroblasts. In this report IL-1 is tested on gingival (GF) and periodontal ligament fibroblasts (PLF) for its ability to increase collagenolytic activity and procollagenase mRNA and protein. GF produce a 3- to 7-fold increase in collagenase activity, while PLF collagenase activity is rarely increased above control amounts by IL-1 treatment. In contrast, both cell types demonstrate an increase in procollagenase protein production with IL-1 treatment. RNA from both GF and PLF contain procollagenase mRNA as demonstrated when northern blots of fibroblast total RNA are hybridized with the cDNA for human procollagenase. Treatment with IL-1 increases the steady-state levels of this message in GF by up to 10-fold in 48 hours when measured with dot blot analysis standardized for poly-A RNA. PLF also produce up to 7 times more message at the same dose and time. Since fibroblasts present in the lesion are exposed to inflammatory cell products it is possible that the production of collagenase by these cells could result in the destruction of the periodontal fibrous attachment.

Blotting, Western↗