Biomedical subjects

J R Rubin

Publications and source records attributed to J R Rubin.

At least 55 records · Page 3Linked to original sources

PubMed1990

Unna's boot vs polyurethane foam dressings for the treatment of venous ulceration. A randomized prospective study.

Recent reports have suggested that polyurethane foam dressings provide a more rapid and comfortable healing of venous stasis cutaneous ulcerations than standard semirigid impregnated gauze dressings. This multi-institutional study consists of a randomized, prospective comparison of 36 consecutive patients who were treated with either polyurethane foam dressings (group 1, n = 17) or Unna's boot (group 2, n = 19) for venous ulceration of the lower extremities. Ulcer size ranged from 6.0 to 270 cm2 (mean, 32.2 cm2) for group 1 and 0.2 to 600 cm2 (mean, 76.0 cm2) for group 2. Nine (52.9%) of 17 group 1 patients withdrew from the study due to wound odor, while there was 100% compliance in group 2. Overall wound healing was superior in group 2 (18 [94.7%] of 19) as compared with group 1 (7 [41.2%] of 17) (chi 2 = 8.2). The rate of healing was also better in group 2 (0.5 cm2/d) than in group 1 (0.07 cm2/d). Contrary to published European trials, impregnated gauze dressings exhibited superior treatment results when compared with polyurethane foam dressings in the current study.

Bandages↗

PubMed1990

Carotid endarterectomy for chronic retinal ischemia.

Carotid arterial disease may result in a variety of ischemic ocular problems that can eventually lead to permanent blindness. From 1984 to 1988, 18 patients underwent reconstruction of the carotid artery in an attempt to restore normal retinal arterial flow and, thereby, reverse or prevent progression of ischemic oculopathy. During a mean period of 21 months after carotid arterial reconstruction, subjective improvement in vision as well as a resolution in eye and periorbital pain was reported in 87.5 per cent of the patients. Measured visual acuity improved or stabilized in 94.4 per cent; macular photostress recovery times improved in 87.5 per cent, funduscopic examinations noted improvement or resolution in ischemic signs in 93.3 per cent and intraocular pressures improved in two of three patients. One patient experienced recurrent episodes of amaurosis fugax, which resolved after two weeks and did not recur. A second patient experienced an increase in intraocular pressures with visual deterioration, required laser photocoagulation after which the condition of the patient stabilized but only after significant visual impairment. Carotid arterial reconstruction is effective for the treatment of ischemic oculopathy and is most beneficial if performed early, before the onset of irreversible neovascular glaucoma.

Aged↗

PubMed1990

Timing of carotid endarterectomy after acute stroke.

An arbitrary delay of at least 6 weeks before performing carotid endarterectomy after acute stroke has been recommended based on anecdotal reports. This prolonged interval may increase the danger of recurrent neurologic deficit before surgery. From September 1978 to September 1988, carotid endarterectomy was performed on 140 patients at variable intervals after stroke. Eleven patients had temporary stroke, which left 129 patients with neurologic symptoms that persisted for 3 weeks or had a cortical infarct on CT scanning. A prospective therapeutic protocol was applied to 82 patients admitted with acute stroke. They were observed until neurologic recovery reached a plateau, based on clinical observation by a neurologist, before performing angiography and carotid endarterectomy (group I). Forty-seven patients were not seen until after recovery from stroke was established (group II). At initial presentation, the severity of neurologic deficit was classified as mild, moderate, or severe in 31%, 58%, and 11%, respectively. Recovery before operation was registered as complete in 11%, mild residual in 66%, moderate residual in 21%, and severe residual in 2%. Group I patients (n = 82, 64%) were operated on within 6 weeks of stroke and group II (n = 47, 36%) were operated on at varying times after 6 weeks. No significant difference was found in the incidence of cerebrovascular events (1.2% vs 4.2%) and deaths (1.3% vs 2.1%) between groups I and II with respect to the timing of carotid endarterectomy, and no significant difference was found between patients operated on at 2, 4, 6, or more than 6 weeks after stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1989

Crystallization and preliminary X-ray diffraction studies of bovine recombinant immune interferon.

Reproducible conditions have been established for the crystallization of recombinant bovine immune interferon. Two cystalline forms of this protein were obtained. A tetragonal form, space group P422, with unit cell dimensions a = b = 59.0 A and c = 125.7 A and an orthorhombic form, space group P2(1)2(1)2(1), with unit cell dimensions a = 42.80 A, b = 79.90 A and c = 85.64 A were obtained under similar crystallization conditions. The orthorhombic form diffracts to 2.6 A resolution, contains a single interferon dimer in the asymmetric unit of structure and is suitable for X-ray diffraction analysis.

Animals↗

PubMed1989

Femoral-tibial bypass for calcific arterial disease.

Overt calcification of the recipient artery and outflow bed has been regarded as a poor prognostic factor for femoral-distal arterial bypass patency and subsequent wound healing. In order to determine the short- and long-term limb salvage and graft patency rates achieved in these patients, the records of 35 patients undergoing 38 attempted femoral-tibial bypasses to a calcified recipient artery were reviewed. Two patients were unreconstructable at the time of surgery. Thirty-one of the 36 operations (86 percent) were performed using in situ saphenous vein bypass techniques, 3 were performed with polytetrafluoroethylene (PTFE), 1 with a composite sequential, and 1 with a composite vein graft. Immediate limb salvage was achieved in 31 of 36 limbs (86 percent). Five early below-knee amputations (14 percent) were required, two due to graft thromboses and three due to progressive foot necrosis despite patent grafts. One patient (3 percent) died secondary to sepsis. Three-year primary graft patency and limb salvage rates did not differ significantly from bypasses to noncalcified vessels. Femoral-distal bypass in the presence of overt calcific arterial disease may be successfully accomplished and offers an excellent prognosis for long-term graft patency and limb salvage.

Adult↗

PubMed1988

Do operative results justify tibial artery reconstruction in the presence of pedal sepsis?

An aggressive surgical approach is warranted in all patients with a salvageable weight-bearing pedal surface. Although patients with pedal sepsis (69 limbs) had a lower 30 day limb salvage rate and higher morbidity and mortality rates than those without sepsis (34 limbs), the long-term salvage rates of both groups by life table analysis were not statistically different and remained at the 70 percent level 3 years postoperatively. Peribypass amputation, debridement of the septic foot, or both should be carried out when deemed necessary to decrease the risk of septic complications after revascularization. Other risk factors such as diabetes or heart disease had no bearing on the short-term results of bypass in either the septic or nonseptic group. Autogenous saphenous vein is preferable to synthetic bypass material, especially in patients with ongoing infection. Lastly, even though the medical climate in 1988 must reflect the stark reality of economic restrictions imposed by third-party payors, optimal patient care remains our primary responsibility. We believe that long-term pedal salvage, as achieved by arterial reconstruction, aggressive wound management, and rehabilitation, attains this goal.

Amputation, Surgical↗

PubMed1988

Effect of hemodilution on brain tissue during global ischemia.

This study evaluates the effect of blood volume and hematocrit changes on brain tissue during temporary global ischemia. Normal saline was administered intravenously to 55 gerbils to achieve hypo-, normo-, and hypervolemic hemodilution and uniform 30% hematocrit reduction. Each group had unilateral carotid artery ligation and temporary (20 minute) contralateral carotid occlusion. After ten days or death, brains were harvested, preserved in formalin, sectioned in a manner which provided adequate samples of both cortex and hippocampus, and stained with H&E and luxol fast blue. They were then examined and staged microscopically for white and gray matter infarction, edema, and neuronal injury and loss. Histologic studies were performed in a randomized and blinded manner and were classified by one of four categories: normal, minimal, moderate, and severe changes. Three of ten (30%) controls survived ten days but had severe neuronal loss, minimal cerebral edema and a minimal to moderate number of white matter strokes. Survival was best in animals treated with hypovolemic hemodilution (43%). Other rates were: normovolemic (33%), controls (30%), and hypervolemic (8.3%). The degree of brain tissue damage was markedly less in the normovolemic group. In this model, normovolemic hemodilution followed by hypovolemic hemodilution offered the best overall cerebral protection during global ischemia.

Animals↗

PubMed1988

Carotid endarterectomy in a metropolitan community: the early results after 8535 operations.

Several retrospective community surveys have provoked speculation concerning the safety of carotid endarterectomy (CEA) throughout the United States. To address this serious issue, surgical outcome was calculated for 8535 CEAs entered prospectively into a computer registry by 51 trained vascular surgeons in a large metropolitan area from 1973 to 1985. A total of 7480 procedures (88%) were performed for symptomatic lesions and 1055 (12%) were performed for asymptomatic stenosis or ulceration. There were 178 operative strokes (2.1%) and 135 early deaths (1.6%), for a combined morbidity-mortality rate of 3.2%. Fatal events were attributed to cardiac disease in 0.7%, neurologic complications in 0.6%, and other causes in 0.3%. The stroke rate (n = 148; 2.0%) in symptomatic patients was better than that in asymptomatic patients (n = 30; 2.8%) (chi 2 = 5.2; p less than 0.025), but the combined morbidity-mortality rates (2.9% and 3.7%) were not statistically different. The incidence of stroke reported by surgeons who performed more than 5 CEAs annually (1.7%) was statistically superior to the stroke rate (3.4%) among those with less experience (chi 2 = 37.1; p less than 0.0001). Nevertheless, both groups had acceptable results that were consistent with their training and continued interest in vascular surgery.

Aged↗

PubMed1988

Combined thrombolytic therapy and percutaneous transluminal angioplasty for treatment of complex arterial graft thrombosis--a case report.

Combined catheter-directed thrombolytic therapy followed by percutaneous transluminal angioplasty (PTA) was successfully performed for the treatment of a thrombosed complex mesenteric artery bypass graft resulting from an anastomotic stenosis. Restenosis of the graft due to neointimal hyperplasia was subsequently treated by PTA, with resultant long-term patency. This approach is an attractive alternative to surgical thrombectomy and graft revision, especially in patients who are poor surgical risks owing to concurrent medical problems.

Aged↗

PubMed1988

Management of failed prosthetic grafts at the time of major lower extremity amputation.

During a 2-year period 75 patients underwent 77 major lower extremity amputations for arterial insufficiency deemed untreatable by reconstruction (36 primary and 41 after failed infrainguinal arterial bypass). Patients with nonfunctional prosthetic grafts were randomized prospectively to either partial graft removal or complete graft removal, performed simultaneously with amputation, to determine which technique more effectively reduces delayed wound healing, stump infection, operative revision, and process-related death. Patients with known graft and deep wound infection were excluded from this review, as were patients who had positive graft cultures at the time of amputation. Partial graft removal resulted in an increased rate of delayed wound healing (47.8% vs 7.7%; chi 2 5.9, p less than 0.025) and secondary stump infection (39.1% vs 7.7%; chi 2 4.4, p less than 0.05), when compared with complete graft removal. The operative revision and process-related mortality rates were also higher in limbs that had partial graft removal, although not statistically significant. The operative morbidity and mortality rate was no greater in the group with complete graft removal, although the mean operative time was nearly doubled (1.4 vs 2.6 hours). Therefore we recommend that all nonfunctional prosthetic graft material be removed concomitant with major lower extremity amputation to avoid the excessive number of wound healing and suppurative complications that are encountered when residual graft material is present in the amputation stump.

Amputation, Surgical↗

PubMed1988

The immediate postoperative prosthesis (IPOP) in ischemia and septic amputations.

A retrospective analysis of the medical records of 17 consecutive patients undergoing lower extremity amputation and Immediate Postoperative Prosthesis (IPOP) placement for infectious complications of unreconstructable arterial insufficiency was performed. Significant soft tissue infection was present in 13 patients and osteomyelitis in four. The mean patient age was 59.4 years and 13 of 17 patients were diabetic. Fourteen patients underwent below knee and three underwent above knee amputations. Seven patients had undergone previous arterial reconstruction. Thirteen patients had previous ipsilateral amputations, five of which were open guillotine amputations performed between 3 and 7 days prior to definitive surgery. Four individuals (24%) required early removal of the IPOP, two due to patient noncompliance and two due to stump healing complications. Thirteen patients (76%) were successfully treated with IPOP and went on to achieve independent gait within 3 weeks of their definitive amputation.

Adult↗

PubMed1987

Duplex scanning versus conventional arteriography for the evaluation of carotid artery plaque morphology.

Examinations that are performed for the evaluation of the extracranial cerebrovascular system need to supply accurate information regarding the luminal surface of the carotid artery as well as the morphologic characteristics of the plaque. To compare conventional carotid artery angiography and Duplex scanning, 32 consecutive patients underwent both evaluations, the results of which were compared, in a blinded manner, to the plaque characteristics noted on direct examination by the attending surgeon and pathologist. The following observations were made: angiographic and Duplex scanning evaluations concurred with direct-specimen examination for luminal narrowing in 31 of 32 patients (97%) and 30 of 32 patients (94%), respectively, whereas Duplex scanning was more accurate for diagnosing ulcerative lesions, 13 of 14 patients (93%), than angiography, five of 14 patients (36%) (p less than 0.0001). Luminal surface irregularity was accurately described by Duplex scanning in 20 of 23 patients (87%) and by angiography in 11 of 23 patients (48%) (p less than 0.005), whereas plaque morphology or consistency was not commented on with angiography but was accurately described with Duplex scanning in 12 of 12 patients (100%). This series clearly demonstrates that both angiography and Duplex scanning are extremely accurate for determining the reduction in the diameter of the carotid artery, whereas Duplex scanning is more accurate for detecting important plaque characteristics such as irregularity, ulceration, and composition.

Angiography↗

PubMed1986

Descending thoracic aorta-to-femoral artery bypass.

Descending thoracic aorta-to-femoral artery grafts were placed in 13 patients who had abdominal aortas deemed undesirable for surgical treatment. These included seven patients in whom an infected aortic graft had been removed for primary graft infection (three) or aortoduodenal fistula (four). These patients had been treated initially with axillary-femoral grafts. In five other patients, this approach was used following failure of at least two previous aortofemoral grafts. The remaining patient was so treated following multiple complex abdominal operations. The surgical technique involves a posterolateral, seventh interspace thoracoabdominal incision with a transdiaphragmatic retroperitoneal tunnel to the left groin. There was no operative mortality. The mean follow-up of all patients was 22 months (range, one to 44 months). All grafts remained patent except one, which was removed because of ascending groin infection. Three patients died, at 24, 29, and 44 months postoperatively, respectively. Reasonable perioperative morbidity and reliable patency make this an attractive technique for the conversion of axillofemoral bypasses and, when reentry of the abdominal cavity is undesirable, laparotomy is avoided.

Aorta, Thoracic↗

PubMed1986

The value of carotid endarterectomy in reducing the morbidity and mortality of recurrent stroke.

Survivors of ischemic stroke are at high risk of sustaining recurrent strokes, which tend to be more severe and are often fatal. Controversy exists regarding whether or not carotid endarterectomy (CEA) achieves its objectives of preventing recurrent stroke and reducing subsequent death in such patients. Therefore, we analyzed the records of 275 consecutive patients who underwent 350 CEAs between 1977 and 1983 and identified 95 patients (34.5%) who had suffered a preoperative stroke, which was the primary indication for operation. All had either full recovery (13.7%) or only mild (63.2%) or moderate (23.1%) neurologic deficits at the time of operation. Patients with severe deficits did not undergo operation. The operations were performed whenever the neurologic recovery had reached a plateau, without a specific interim waiting period between the stroke and the operation. The combined operative morbidity/mortality rate was 2.7% (three patients), both deaths caused by stroke in patients with mild preoperative neurologic deficits and one (0.9%) nonfatal postoperative stroke involving the retina in a patient who also had a mild preoperative deficit. Long-term follow-up averaged 32 months (range, 6 to 72 months). No ipsilateral recurrent strokes occurred during this period after CEA. Life-table analysis revealed a recurrent stroke rate of 3.2% (0.64% per year) and a 5-year survival rate of 81.3%. Patients who were neurologically normal at the time of operation had a cumulative 5-year survival rate of 90.9%. None of the late deaths was due to recurrent stroke.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1985

A comparison of three chemotherapeutic regimens in the treatment of advanced pancreatic and gastric carcinoma. Fluorouracil vs fluorouracil and doxorubicin vs fluorouracil, doxorubicin, and mitomycin.

Three hundred five patients with advanced pancreatic and gastric carcinoma were randomly assigned to treatment with fluorouracil, fluorouracil plus doxorubicin (Adriamycin) (FA), or fluorouracil plus doxorubicin plus mitomycin (mitomycin C) (FAM). All regimens were equivalent with regard to patient survival. There is no reasonable likelihood that either the FA or FAM regimen could produce a meaningful survival advantage over fluorouracil alone. Interval to disease progression, objective response rates, and palliative effects (improved performance, body weight, or symptoms) were essentially equivalent among the three regimens. With regard to toxicity, the FAM regimen produced more anorexia, nausea, vomiting, leukopenia, thrombocytopenia, and cumulative bone marrow suppression. Fluorouracil alone produced more stomatitis and diarrhea. Because of a failure to produce improved survival or palliation, unrewarded toxicity, and excessive cost, neither the FA nor FAM regimen can be recommended for the treatment of advanced pancreatic or gastric cancer.

Adenocarcinoma↗

PubMed1985

X-ray studies on the interaction of the anticancer agent cis-[Pt(NH3)2cl2] to tRNAphe. A mechanism for the formation of the intrastrand cross-link to adjacent guanines in DNA.

The interaction of the potent anticancer agent cis-[Pt(NH3)2cl2] to phenylalanine tRNA from yeast has been investigated by x-ray crystallography. Two major binding sites were excavated from difference Fourier maps and both showed monodentate binding to guanine bases (G15 and G18) at N7. The expected intrastrand cross-linked complex between adjacent guanines was not observed in tRNA. Although both bases G15 and G18 are in the dihydrouridine loop, they are engaged in tertiary base interactions viz. G15-C48 and G18-psi 56. The high C1- ion concentration in the crystal made the reaction sluggish and was perhaps responsible for the formation of only the monodentate complex. This appears to be the initial complex that is formed during the interaction of the Pt drug with DNA, with a subsequent attack of the drug on the N7 of the 5'-side guanine base to generate the expected intrastrand cross-linked product involving adjacent guanines. The wedge-shaped Pt-GG complex that is formed perturbs not only the local geometry but also produces a kink or bend in the DNA duplex.

Chemical Phenomena↗

PubMed1985

The role of the lymphatic system in acute arterial prosthetic graft infections.

No experimental data have been published that evaluate the role of lower extremity lymphatics in the pathophysiology of arterial graft infection. Bilateral interpositional femoral artery graft (PTFE) replacements were performed in 21 greyhounds, accompanied by unilateral limb ischemia-rendering operations and ipsilateral bacterial inoculations with standardized inocula of Escherichia coli and Staphylococcus aureus. Inguinal lymphatics in the ischemic leg were either simply transected (group I), carefully preserved (group II), or excised and ligated (group III) at the time of femoral graft implantation. The grafts were harvested 48 hours later and graft and blood cultures obtained. There was an 87.5% incidence of positive graft cultures in groups I and II, but both organisms were cultured significantly more often in group II than in group I (62.5% vs. 12.5%; p less than 0.01). Blood culture data were similar. The incidence of positive graft and blood cultures in group III was only 20%, and no cultures obtained were positive for both organisms. Cultures of contralateral control grafts yielded both organisms in all group II dogs compared with only 25% of group I and 0% in group III (p less than 0.01). These results suggest that the lymphatics probably contribute to the development of acute graft infection by absorbing bacteria, and either transporting them to the systemic circulation via lymphatic-venous communications when the lymphatics are intact, causing hematogenous contamination of a graft, or by directly bathing the implanted graft when the lymphatics are disrupted proximal to a septic focus. Careful isolation, transection, and ligation of the inguinal lymphatics at the time of arterial reconstruction might minimize acute graft sepsis.

Acute Disease↗

PubMed1985

Peripheral vascular disease: treatment and referral of the elderly. Part I.

In the elderly, arterial disease may not necessarily require operative intervention if the patient is not functionally disabled or can adjust to self-imposed limitations. However, with nonhealing skin lesions, gangrene, impending limb loss, or ischemic rest pain, reconstructive arterial surgery must be considered. Pain at rest signals advanced limb-threatening ischemia. The pattern of pain distribution over the foot distinguishes it from common nighttime leg cramps.

Aged↗