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Biomedical subjects

F W LoGerfo

Publications and source records attributed to F W LoGerfo.

At least 55 records · Page 3Linked to original sources
PubMed1996

Evaluation of anastomotic hyperplasia progression using the cyclin specific antibody MIB-1.

BACKGROUND: Delayed failure of prosthetic arterial grafts is primarily due to the development of anastomotic intimal hyperplasia. This report follows the proliferation of smooth muscle cells that ensues after prosthetic arterial grafting, using the cyclin-specific antibody MIB-1. METHODS: Six-mm expandable polytetrafluoroethylene (ePTFE) grafts were placed end-to-end in the carotid arteries of mongrel dogs. Animals were randomly assigned to sacrifice intervals of 2, 7, 14, and 30 days. Serial coronal sections were cut and immunohistocytochemistry performed using the MIB-1 antibody. RESULTS: The control carotid artery had no definable proliferation. Two days after grafting, there was brisk proliferation in the upper one third of the arterial media. By 7 days, proliferation and migration of smooth muscle cells was seen above the internal elastic lamina, in which 50% of the cells were MIB-1 positive. Fourteen days after graft placement, proliferation continued in the neointima; however, the proliferation index was diminished compared with previous time intervals. At 30 days, despite a dramatic increase in lesional increase, there was a marked decrease in the overall proliferation of cells. CONCLUSIONS: Following placement of a prosthetic arterial graft, there is initial brisk proliferation of cells in the arterial media, with migration, ongoing proliferation, and resultant development of a localized cellular neointima. Over a 30-day period, the percentage of cells proliferating subsides in contrast to the progressive increase in the size of the neointima. Immunohistocytochemistry with the MIB-1 antibody is a useful tool in defining the cellular kinetics after prosthetic arterial grafting.

Anastomosis, Surgical↗
PubMed1996

Results of a policy with arm veins used as the first alternative to an unavailable ipsilateral greater saphenous vein for infrainguinal bypass.

PURPOSE: Aggressive policies for distal bypass and coronary revascularization increase the need to identify alternatives to autologous saphenous vein grafts. We examined the performance of arm vein as the primary alternative to contralateral saphenous vein when the ipsilateral saphenous vein was not available. METHODS: A total of 250 arm vein grafts were studied retrospectively in 224 patients (143 men, 81 women, 82.6% with diabetes, mean age 68.3 years) from February 1989 to April 1994. Intraoperative angioscopy was carried out to observe valve lysis, remove abnormalities, and select optimal vein segments. RESULTS: A total of 85 primary, 103 repeat, and 62 graft revision procedures were done for limb salvage in 99.2% of the patients. A total of 41 femoropopliteal, 114 femorotibial-pedal, 33 popliteodistal, and 62 jump or interposition grafts were constructed. A total of 199 grafts were single vein, and 51 were composite vein. The source was cephalic vein alone in 50.4%, cephalic and basilic vein in 35.6%, and basilic vein only in 14%. The contralateral saphenous vein as an alternative conduit was available in 97 (38.8%) instances. Interventions guided by angioscopy to "upgrade" the graft were necessary in 51.6%. Overall early patency (< or = 30 days) was 94.8% (n = 13 occlusions). The cumulative primary patency rate at 1 year was 70.6%, the secondary patency rate was 76.9%, and the limb salvage rate was 88.2%. The 3-year patency rate (limb salvage) was 51.9% (92.4%) for primary grafts, 56.7% (67.1%) in revision grafts, and 42.4% (79.9%) in repeat grafts. In 22.7% (22 of 97) the available contralateral saphenous vein was used for distal revascularization within the follow-up period. CONCLUSIONS: Arm veins are an easily accessible autologous conduit of sufficient length to reach the midtibial level. Excellent patency rates allow durable limb salvage in otherwise difficult circumstances. Vein configuration and splicing do not affect patency rates, but vein quality and repeat operations do. Angioscopy is a valuable adjunct to upgrade graft quality. The contralateral saphenous should be saved for subsequent contralateral revascularization or coronary artery bypass grafting.

Adult↗
PubMed1996

Infrapopliteal bypasses to severely calcified, unclampable outflow arteries: two-year results.

PURPOSE: Although severe, circumferential calcification of distal outflow vessels is frequently encountered, its effect on bypass graft patency rates has not been well established. METHODS: Using a computerized vascular registry database, we conducted a retrospective review of 1957 bypass grafts with distal anastomoses to infrapopliteal vessels performed at a single institution between 1990 and 1995. Of these cases, 101 procedures involved outflow arteries classified by the operating surgeon as severely calcified and unclampable (requiring intraluminal occluders for vascular control), whereas in 105 cases the outflow arteries had no calcification present at the distal anastomotic site. The remaining cases had varying intermediate degrees of calcification and were not analyzed. Indication for bypass procedure was limb-threatening ischemia in 90% of severe calcification cases and in 84% of cases without calcification. Atherosclerotic risk factors were similar except for the presence of diabetes (92% vs 74%, p < 0.001), creatinine level > 2.0 mg/dl (21% vs 8%, p < 0.01), and dialysis dependency (17% vs 3%, p < 0.001), all of which were more prevalent in the severe calcification group. Infrapopliteal distal anastomotic location and type of conduit ( > 90% autogenous vein) were comparable between groups. RESULTS: Primary patency, secondary patency, and foot salvage rates at 24 months were 60%, 65%, and 77% for the severe calcification group and 74%, 82%, and 93% for the no calcification group, respectively. With secondary procedures comprising 26% of cases in each group, data from the 150 primary procedures were reanalyzed separately. In this primary procedure group, 24-month primary patency, secondary patency, and foot salvage rates were 66%, 69%, and 77% for the severe calcification group and 84%, 90%, and 96% for the no calcification group, respectively. Although patency and salvage rates were consistently lower for the severe calcification group in all analyses, these differences did not achieve significance by log-rank life-table analysis at 2-year follow-up. Perioperative 30-day mortality (0.99% severe calcification vs 0.95% no calcification) and 24-month survival rates (84% severe calcification vs 83% no calcification) were also similar between groups. CONCLUSION: These data suggest that effective techniques exist to perform infrapopliteal bypasses to severely calcified, unclampable outflow arteries with results comparable with those obtained with clampable, uncalcified vessels. The finding of severe, circumferential calcification of outflow target arteries should not dissuade vascular surgeons from distal bypass for limb salvage indications.

Aged↗
PubMed1996

Vascular disease of the lower extremities in diabetes mellitus.

Vascular disease, neuropathy, and infection act synergistically to cause diabetic foot ulceration. Appropriate care is hindered by misconceptions about microvascular disease. Recent advances and success with extreme distal revascularization combined with surgical management of infection have greatly improved salvage of the diabetic foot. Success is enhanced by a multidisciplinary team approach.

Diabetes Complications↗
PubMed1995

The influence of race on the use of surgical procedures for treatment of peripheral vascular disease of the lower extremities.

OBJECTIVE: To assess whether rates of amputation and leg-sparing surgery for peripheral vascular disease of the lower extremities differ between African-American and white patients. DESIGN: Retrospective cohort study using Medicare claims data for 1989 and 1990. SETTING: A total of 3313 hospitals in the United States. PATIENTS: Random sample of 19,236 Medicare Part A enrollees who underwent amputation and/or leg-sparing surgery for peripheral vascular disease. MAIN OUTCOME MEASURES: Adjusted odds of toe and/or foot amputation, below-knee amputation, above-knee amputation, lower extremity arterial vascularization, and percutaneous transluminal angioplasty for African American relative to whites, controlling for case-mix, region, and hospital characteristics. RESULTS: African-American patients were significantly more likely than white patients to undergo above-knee, below-knee, and toe and/or foot amputation and significantly less likely to undergo lower-extremity arterial revascularization and percutaneous transluminal angioplasty. These associations occurred for diabetic patients and nondiabetic patients but were more pronounced among patients who did not have diabetes. CONCLUSIONS: Potential explanations include unmeasured factors such as severity of disease and the technical expertise available at hospitals or other factors such as lack of compliance with medical treatment and race-specific treatment decisions by providers. Whatever the cause, interventions aimed toward reducing the number of amputations among African Americans are needed. Further work is required to determine where such interventions should be targeted.

Black or African American↗
PubMed1995

Modification of polyethylene terephthalate (Dacron) via denier reduction: effects on material tensile strength, weight, and protein binding capabilities.

Thrombosis remains a significant and potentially catastrophic complication of polyethylene terephthalate (Dacron) prosthetic vascular graft implantation. Numerous attempts have been made to create a novel surface that reduces the adverse effects of blood interaction with the material. The purpose of this study was to create reactive groups on Dacron without significantly altering the chemical and physical properties of the biomaterial. These groups would then serve as "anchor sites" for covalent attachment of the blood protein albumin to the surface, thus creating a more biocompatible surface. Denier reduction, an established textile chemistry procedure that creates carboxyl groups on the fiber surface via hydrolysis of the material, was performed at 100 degrees C using sodium hydroxide concentrations of 0.5, 1.0, 2.5, and 5.0% (treated materials referred to as 0.5% hydrolyzed etc.). Tensile strength determination of hydrolyzed materials revealed no statistically significant difference in material strength between control, 0.5, and 1.0% hydrolyzed materials; the 2.5 and 5.0% hydrolyzed materials had significant strength loss as compared to the controls. Significant fiber weight loss occurred in the 1.0, 2.5, and 5.0% hydrolyzed Dacron segments. The 0.5% hydrolyzed material did not have any significant weight loss. Covalent linkage of 125I-albumin to these modified materials using the crosslinker 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide hydrochloride (EDC) resulted in the 0.5% hydrolyzed material having the greatest protein binding (330 ng/mg Dacron, 2,4-fold greater than control). Incubation of the 0.5% hydrolyzed material with EDC and various concentrations of 125I-albumin resulted in the 14.80 microM solution permitting the greatest binding per milligram Dacron (330 ng/mg Dacron). Scanning electron microscopy, performed blindly, revealed no change in the 0.5% hydrolyzed Dacron as compared to untreated Dacron. The 5.0% hydrolyzed Dacron, however, had noticeable structural damage on the outer periphery of the fiber surface. Observation of the untreated Dacron with nonspecifically bound albumin showed scattered areas of albumin adherent to the fiber surface whereas covalent linkage of albumin to the 0.5% hydrolyzed Dacron via EDC crosslinking showed numerous albumin moieties on each fiber. This study demonstrates that a clinically accepted biomaterial (Dacron) can be chemically modified, without significantly altering the physical and chemical characteristics of the biomaterial, in order to covalently bind albumin to the fiber surface. Thus, these results serve as foundation for creating potential novel biomaterials without significantly altering the properties of the original biomaterial.

Animals↗
PubMed1995

Platelet activation by healing ePTFE grafts.

The purpose of this study was to examine the effect of the in vivo maturing ePTFE graft surface on platelet activation. Ten canines were randomized to receive either a carotid to infrarenal aorta ePTFE graft or sham operation. Animals were sampled at specific time points up to 3 months postoperatively. Whole blood platelet aggregometry (arachidonic acid, ADP, and collagen agonists) and ATP secretion (in response to arachidonic acid, ADP, collagen, and thrombin) were measured. Additionally, complete hematologic analysis and histology were performed. With time, graft animals showed significantly more decrease in platelet aggregation in response to ADP compared to sham animals (P = .023). The total amount of ATP per platelet was not different, as demonstrated by equivalent ATP release per platelet in response to thrombin. Over the first week, grafted dogs developed a decrease in systemic platelet count of 50% (P < .001) that persisted over the 3-month follow-up period. With time, overall regression model slopes of graft and sham platelet count data were not statistically different (P = .29). Histologically, the grafts demonstrated limited cellular ingrowth at both anastomoses, with fibrin matrix along the remainder of the blood-biomaterial interface. These data suggest that, similar to Dacron, exposure to an ePTFE surface results in significant changes in platelet biology, and these platelet-ePTFE interactions persist even after the graft has formed a mature pseudointima. The pseudointima appears to be the primary determinant of the blood-biomaterial interaction.

Adenosine Triphosphate↗
PubMed1995

The upper arm basilic-cephalic loop for distal bypass grafting: technical considerations and follow-up.

PURPOSE: The performance of a graft created from the upper arm basilic and cephalic veins in continuity was investigated. METHODS: Retrospective analysis of 50 patients, who underwent 54 distal reconstructions with an upper arm vein loop graft between February 1989 and October 1993 (male-to-female ratio of 30/20; mean age of 69.2 years, range 39 to 87; 74% had diabetes) was undertaken. Vein grafts were harvested through a near continuous incision, leaving a skin bridge in the cubita. Intraoperative angioscopy was used to exclude endoluminal disease and to directly observe valvulotomy of the nonreversed part of the graft. RESULTS: Operations were performed for limb salvage in 98.2% of 17 primary and 37 reoperative procedures. Eleven femoropopliteal, 33 femorotibial-pedal, seven popliteal-distal, and two outflow jump grafts were performed. The ipsilateral saphenous vein was unavailable because of previous infrainguinal bypass in 35, coronary artery bypass grafting in 14, and unsuitable quality in 5 cases. Thirty-eight grafts were used in continuity, and 16 grafts required repair or splicing with additional vein segments. Primary 30-day patency rate was 92.6% (n = 4 occlusions). No operative deaths occurred. The cumulative patency rate at 1 year was 74.4%, the limb salvage rate 90.7%. CONCLUSIONS: The upper arm vein loop is a durable graft with excellent short-term and midterm patency rates. Sufficient vein length can be obtained to reach the below-knee and midtibial levels. Angioscopic quality assessment is a valuable adjunct to exclude endoluminal disease most commonly occurring in the median cubital vein. Straightening the curve of the median cubital vein and valvulotomy do not influence patency rates. This is a valuable technique for vascular surgeons that enables rescue of ischemic limbs under otherwise difficult circumstances.

Adult↗
PubMed1995

Return to well-being and function after infrainguinal revascularization.

PURPOSE: The purpose of this study was to assess functional status, well-being, and symptom relief of patients after infrainguinal revascularization for severe peripheral vascular disease. METHODS: Two questionnaires were used to assess symptoms, functional status, and well-being before operation and 6 months after operation. Sociodemographics, comorbidities, indications for surgery, graft location, and morbidity, mortality, patency, and limb salvage rates were obtained via vascular registry. RESULTS: Of 318 patients who underwent revascularization over a 1-year period, 276 patients were asked to complete the questionnaires. Of the 156 patients who completed both questionnaires, mean age was 66 years, 67% were men, 84% had diabetes mellitus, and 83% had various heart-related conditions. Mean length of stay was 15.3 days. Distal graft sites were popliteal (29%), tibial/peroneal (40%), and pedal/plantar (31%). The operative morbidity rate was 21%, the cumulative primary graft patency rate was 93%, the cumulative secondary graft patency rate was 95%, and the limb salvage rate was 97% at 6 months. At follow-up, improved functioning of instrumental activities of daily living, mental well-being, and vitality were reported. Symptoms of calf cramping and toe or foot pain when walking and at rest were also improved. Sores or ulcers improved, but leg swelling did not. The only independent predictor of improved function and well-being was the patients' perception of their status at baseline: those patients who functioned better before operation reported improved function and well-being at 6 months. Only 45% of patients reported feeling "back to normal" at 6 months. CONCLUSION: Reported health status at baseline was a predictor of improved function, mental well-being, and resolution of symptoms after infrainguinal revascularization. Expected return to "normal" may take longer than 6 months.

Activities of Daily Living↗
PubMed1995

Isolation of genes differentially expressed at the downstream anastomosis of prosthetic arterial grafts with use of mRNA differential display.

PURPOSE: Downstream anastomotic intimal hyperplasia in prosthetic arterial grafts remains a major cause of delayed graft failure. The new method of messenger RNA (mRNA) differential display was used to screen numerous genes to gain insight into the molecular mechanisms of intimal hyperplasia. METHODS: Fifty-centimeter-long 8 mm expanded polytetrafluoroethylene grafts were placed in four mongrel dogs from the carotid artery to the distal abdominal aorta. At 3 months the distal anastomoses and adjacent normal aortas were harvested; a portion was taken for histologic examination, and total RNA was isolated from the remainder. Differential mRNA display was used to identify candidate cDNA clones whose expression differed in anastomotic intimal hyperplasia as compared with adjacent unaffected aorta. The clones were sequenced, and national gene databases were searched. Northern blot analysis confirmed alteration of gene expression. RESULTS: Approximately 5000 mRNA species were screened, and 11 candidate clones were obtained. DNA sequence revealed homology of five clones to known gene sequences. Homologous genes included an interferon-gamma-induced human gene, (IGUP I-5111), alpha-1 protease inhibitor gene, human retinoblastoma susceptibility gene, and human creatine kinase gene (two clones). Northern blot analysis revealed altered gene expression in 4 of 11, nonregulation in 1 of 11, and undetectable signals in 6 of 11. Expression of the clone representing IGUP I-5111 in the segment of intimal hyperplasia was found to be decreased over threefold to only 31% +/- 16.4% SE of the level seen in normal aorta. CONCLUSIONS: The technique of mRNA differential display has identified differences in gene expression in an in vivo model of anastomotic intimal hyperplasia. Expression of RNA with homology to an interferon-gamma-induced human gene was consistently decreased within the hyperplastic region at the downstream polytetrafluoroethylene arterial anastomosis.

Anastomosis, Surgical↗
PubMed1995

Dorsalis pedis arterial bypass: durable limb salvage for foot ischemia in patients with diabetes mellitus.

PURPOSE: Although the technical feasibility of pedal artery bypass for limb salvage is now well established, questions remain about its most appropriate use and its long-term durability. METHODS: We reviewed our experience over an 8-year period in 367 consecutive patients undergoing 384 vein bypass grafts to the dorsalis pedis for limb salvage. RESULTS: Ninety-five percent of the patients had diabetes mellitus. Infection complicated ischemia at initial presentation in 55.2% of patients. The preoperative arteriogram demonstrated a patent dorsalis pedis in 362 extremities (92.8%). Four hundred two patients underwent exploration for bypass, including 29 patients without demonstrated arteries on the arteriogram but audible pedal Doppler signals. Successful bypasses were carried out in 357 of 362 cases, where preoperative arteriography demonstrated a patent dorsalis pedis artery (98.6%), 16 of 28 cases explored on the basis of a Doppler signal alone (57%), and 11 of 12 patients where angiographic status was unknown. All procedures were performed with vein: in situ 38.5%, reversed 29%, nonreversed 18%, arm vein 7%, and composite vein 8%. Inflow was taken from the common femoral artery in 34%, superficial femoral or popliteal arteries in 60%, a previously placed graft in 5%, and a tibial artery in 1%. There were seven perioperative deaths (1.8%) and 21 myocardial infarctions (5.4%). Twenty-nine grafts failed within 30 days (7.5%), but 19 were successfully revised. Eight of the 10 failed grafts resulted in major amputation (80%). Over the remaining study period, there were 39 additional graft failures, of which 17 were successfully revised, and 17 additional major amputations. Actuarial primary and secondary patency and limb salvage rates were 68%, 82%, and 87%, respectively, at 5 years' followup. The actuarial patients survival rate was 57% at 5 years. Patency rates were similar for in situ and translocated saphenous vein grafts. CONCLUSIONS: Dorsalis pedis arterial bypass is an effective limb salvage procedure with long-term durability comparable to distal vein grafts placed into more proximal arteries.

Arteries↗
PubMed1994

Role of angioscopy in reoperation for the failing or failed infrainguinal vein bypass graft.

The purpose of this retrospective study is to review our ongoing experience with the use of angioscopy during reoperation for failed or failing infrainguinal vein bypass grafts and define the role of angioscopy in the management of this clinically demanding patient group. All hospital records, arteriograms, and intraoperative angioscopic video recordings of 79 consecutive failed or failing grafts (76 patients) examined with angioscopy during reoperation between 1987 and 1993 were reviewed. Clinical and intraoperative data, comparison of the preoperative arteriogram and intraoperative angioscopic findings, and surgical decisions or interventions resulting from the additional angioscopic findings were collated and analyzed according to a predetermined protocol. Sixty-six additional angioscopic findings were noted during the 79 reoperations and resulted in 61 additional interventions and surgical decisions with salvage of all or part of the graft in 90.9% in the early (< 30 day) failed (group 1), 84.6% in the late (> 30 day) failed (group 2), and 90.3% in the late (> 30 day) failing grafts (group 3). The amount of residual thrombus within the graft, as assessed by angioscopy after all interventions, was the critical determinant for overall early graft patency (p < 0.001) and long-term patency for all the subgroups after reoperation (group 1, p < 0.001; group 2, p = 0.0016; and group 3, p = 0.0194). Intraoperative angioscopy has an important role in these challenging procedures. It provides additional and useful information that not only influences the conduct and extent of the reoperative surgery but may provide insights into the pathogenesis of graft failure.

Adult↗
PubMed1994

Maximizing foot salvage by a combined approach to foot ischemia and neuropathic ulceration in patients with diabetes. A 5-year experience.

OBJECTIVE: The combination of peripheral neuropathy and arterial insufficiency in patients with diabetes frequently results in chronic non-healing foot ulcers. These patients often have a protracted course that commonly ends in limb amputation. RESEARCH DESIGN AND METHODS: Since 1987, 39 diabetic patients presented with 42 neuropathic ulcerations beneath the lesser metatarsal heads, complicated by severe arterial insufficiency. A variety of vascular reconstructions were performed to improve circulation to the foot. After successful vascular reconstruction, 14 patients with deep ulcers underwent resection of the involved bone or joint through a plantar elliptical incision with excision of the ulcer and primary closure (33%). Five patients required a simultaneous panmetatarsal head resection (12%). For fifteen superficial ulcers, metatarsal osteotomy through a dorsal approach was performed (36%). Eight patients underwent a fifth metatarsal head resection through a dorsal approach (19%). RESULTS: In follow-up of 2-64 months (mean 21.2 months), 35 extremities with patent bypass grafts achieved and maintained primary healing of their local foot procedure (83%). Two feet required subsequent revision but ultimately healed (5%). Three feet (7%) developed a new plantar ulceration adjacent to the original one. In two extremities, the foot remained healed in spite of thrombosis of their grafts (5%). One patient with a thrombosed graft required a below-knee amputation. One patient died before the foot healed with a patent bypass graft. Overall, 40 of 42 extremities (95%) ultimately healed over the course of the follow-up period. CONCLUSIONS: We conclude that complex neuropathic ulcers in diabetic patients can be successfully treated by an aggressive surgical approach that removes infected bone and ulcers and corrects underlying structural abnormalities provided arterial insufficiency is corrected first.

Aged↗
PubMed1994

Synthesis and characterization of a recombinant hirudin-albumin complex.

The purpose of this investigation was to covalently bind recombinant hirudin (rHir) to albumin and compare alpha-thrombin inhibition by complexed rHir to rHir. rHir was radiolabelled with 125I and covalently bound to albumin using heterobifunctional cross-linking reagents. HPLC purification of the 125I-rHir-SMCC-albumin complex using gel filtration chromatography resulted in four elution peaks, with the main peak containing an average M(r) of 78 kDa. This peak fraction also contained 63% (+/- 1.4%) of the total protein and 49% (+/- 6.8%) of the 125I-rHir conjugated to albumin. Purification of unbound 125I-rHir from complex was confirmed by SDS gel electrophoresis and autoradiography. 125I-rHir inhibition of alpha-thrombin, measured by an assay utilizing the chromogenic tripeptide substrate H-D-Phe-Pip-Arg-pNA (S-2238), was observed to be non-competitive of linear mixed-type having a Ki of 1.61 pM and an alpha Ki of 1.09 pM. In contrast, complexed 125I-rHir was found to be a pure, non-competitive inhibitor having a Ki of 15.6 pM showing a ten-fold increase. These results demonstrate that covalently bound 125I-rHir still maintains potent alpha-thrombin affinity while losing minimal inhibitory capacity. Thus, successful modification of 125I-rHir serves as the foundation for future alternative applications for this potent inhibitor.

Amino Acid Sequence↗
PubMed1994

Covalent linkage of streptokinase to recombinant hirudin: a novel thrombolytic agent with antithrombotic properties.

In a continuing effort to create an agent which has both thrombolytic and antithrombotic properties, streptokinase (SK) was covalently bound to the potent antithrombin agent recombinant hirudin (rHir). Linkage of SK to 125I-rHir was accomplished via heterobifunctional crosslinkers in an average molar ratio of 1:1. The 125I-rHir-SK complex was purified from starting components by anion exchange and gel filtration chromatography. The major band containing covalently bound 125I-rHir had a molecular weight of 53 kDa as determined by SDS-PAGE and autoradiography. Biologic activity of each component was then assayed utilizing the chromogenic substrate for each compound. Complex bound 125I-rHir exhibited a 1.2 fold decrease in thrombin inhibition when compared to concentrations of 125I-rHir greater than 3.13 nM. Complex bound 125I-SK, replacing the 125I label on rHir, displayed a 7.9-fold loss in plasminogen activation when compared to 125I-SK. These chromogenic assay results were not adversely altered in the presence of the converse compound's substrate. The 125I-SK-rHir complex (examined at various concentrations) also demonstrated a 0.17- to 17-fold greater affinity for thrombin immobilized onto Sepharose beads as compared to 125I-SK. These findings indicate the rHir-SK complex maintained both thrombolytic and antithrombin properties while also obtaining affinity for immobilized thrombin.

Binding Sites↗
PubMed1993

Improved quality of diabetic foot care, 1984 vs 1990. Reduced length of stay and costs, insufficient reimbursement.

Ischemic foot ulceration in the diabetic patient is a source of great physical and emotional strain for the patient and represents a significant financial burden for the health care system responsible for the cost of such care. Limb salvage remains the primary therapeutic goal; yet, fiscal constraints imposed by diagnosis related group-based reimbursement systems require maximal cost efficiency in the care process. Between 1984 and 1990, the changes in our team management approach to this problem, emphasizing aggressive surgical revascularization of threatened limbs, have improved the quality of care and dramatically reduced the major and minor amputation rate. In the process, we have reduced the length of hospital stay and the overall cost of care. Despite this improvement in outcome and efficiency, Medicare reimbursement remains insufficient, with an average loss of $7480 per admission.

Aged↗