Developmental stuttering and Parkinson's disease: the effects of levodopa treatment

The effects of dopamine on developmental stuttering was studied in a 44 year old man with developmental stuttering and Parkinson's disease during three levodopa "on" periods and three "off" periods. When compared with the "off" periods, during the "on"' periods he demonstrated an increase of speech dysfluencies. These findings lend support to the dopamine hypothesis of developmental stuttering.

Symptomatic anterior uveitis in HIV-positive patients

Symptomatic anterior uveitis is rare in HIV-positive patients. The uveitis associated with cytomegalovirus retinitis (CMVR), the commonest ocular manifestation in AIDS patients, is rarely symptomatic and patients do not typically present with a red painful eye in conjunction with blurred vision. In this article we report 12 cases of symptomatic anterior uveitis in HIV-positive patients and discuss the aetiology. The case notes of all HIV-positive patients presenting to the eye department with symptoms of uveitis over a 4-year period were studied retrospectively. The notes were analysed for age, sex, race, risk factors of HIV, features of the uveitis, concurrent disease and CD4 counts. Only 12 patients were identified to have symptomatic uveitis out of a total 172 patients. There were 9 males and 3 females with an average age of 35 years. None of these patients were taking either rifabutin, protease inhibitors or cidofovir. Seven out of the 12 patients had granulomatous uveitis. Of these 7 patients, 4 had CD4 counts over 200 and no other concurrent illness whilst 3 patients, with CD4 counts between 130-200, were subsequently found to have an underlying aetiology namely lymphoma, tuberculosis and candida. The remaining 5 patients, all with CD4 counts below 40, had a history of systemic illness with herpes zoster preceding the onset of the uveitis. HIV-positive patients with symptoms of uveitis do not have active CMVR and the ophthalmologist must search for other causes such as tuberculosis or lymphoma in those with granulomatous uveitis or herpes zoster in those with non-granulomatous uveitis. The CD4 count may be helpful.

Electrocardiographic evaluation of broilers following unilateral occlusion of an extrapulmonary primary bronchus

This study was conducted to provide a comprehensive evaluation of both the amplitudes and durations of the Lead II electrocardiogram (ECG) in nonascitic and ascitic broilers. At 14 d of age, male and female broiler chicks were sham-operated (SHAM, n = 27), or pulmonary hypertension was initiated by occluding one extrapulmonary primary bronchus (BRONCHUS CLAMP, n = 57). Lead II ECG and BW were recorded on Days 28 (ECG1) and 42 (ECG2), necropsies were conducted on all birds dying after Day 28, and final necropsies were conducted on Day 49. Data collected at necropsy included the presence (ASCITIC) or absence (NONASCITIC) of ascites, sex, and ventricular weights for calculating the right:total ventricular weight ratio (RV:TV), which serves as a reliable index of pulmonary hypertension. In each bird, three consecutive ECG1 and ECG2 wave cycles were quantified for both amplitude and duration of the following wave segments: Rb-R, R-S, S-R', R'-R'b, and S-T. The S wave amplitude was calculated by subtracting R-S from Rb-R and heart rate (HR) was measured from the peak of one T wave to the peak of the next. In the majority of comparisons, ASCITIC and BRONCHUS CLAMP broilers had larger S, R'-R'b, and S-T amplitudes, longer R-S, R'-R'b, and S-T durations, and a slower HR than NONASCITIC and SHAM broilers, regardless of sex. The differences in ECG wave forms and durations between ASCITIC and NONASCITIC broilers were greater on Day 42 (ECG2) than on Day 28 (ECG1), but when both ECG were used to develop a regression equation to estimate RV:TV, the R2 was 0.79. The most important Lead II ECG parameters associated with the development of ascites were an increasingly negative S wave amplitude and greater amplitudes and durations for R'-R'b and S-T as well as a decrease in the HR.

Electrocardiographic and genetic evaluation of giant jungle fowl, broilers, and their reciprocal crosses following unilateral bronchus occlusion

Electrocardiography is useful as a noninvasive technique for detecting right ventricular hypertrophy in birds developing pulmonary hypertension (PH) and pulmonary hypertension syndrome (PHS, ascites). The objective of this study was to identify every aspect of the Lead II ECG wave form (amplitude or duration) that can be correlated with right ventricular hypertrophy [increased right:total ventricular weight ratios (RV:TV)] indicative of PH across a broad genetic background. Sham operations were conducted, or PH was induced by occluding one extrapulmonary primary bronchus in 14-d-old chicks produced from matings of broilers (B x B), Giant Jungle Fowl (J x J), and their reciprocal crosses (B x J and J x B). Standard three-lead electrocardiograms (ECG) were recorded on Days 28 and 42, and final necropsies were conducted to evaluate the incidence of ascites, confirm sex, and obtain ventricular weights for calculating RV:TV. Ascites did not develop in the J x J, and one each of the B x J and J x B chicks developed ascites; consequently, only data from birds that did not develop ascites were compared. Heart rate was recorded, and the following amplitudes and durations were measured or calculated for three consecutive wave cycles of the Lead II ECG: base of R to the peak of R (RbR), peak of R to base of S (RS), base of S to peak of R' (SR'), S, peak of R' to base of R' (R'R'b), and base of S to peak of T (ST). Differences between the ECG of sham and bronchus clamp groups were more prominent in B x B and B x J than in J x B, and bronchus occlusion did not affect the ECG, growth, or RV:TV ratios of J x J. In contrast, sex influences were more prominent in J x J and J x B than in B x J and B x B. These observations suggest a paternal pattern of inheritance for Lead II ECG wave forms, with crosses sired by broilers (B x B, B x J) exhibiting susceptibility to PH and few ECG differences related to sex, whereas crosses sired by Giant Jungle Fowl U x J, J x B) exhibited resistance to PH and numerous ECG differences related to sex.

Supersonic molecular beam-hyperthermal surface ionisation coupled with time-of-flight mass spectrometry applied to trace level detection of polynuclear aromatic hydrocarbons in drinking water for reduced sample preparation and analysis time

Analysis of sub-ppb levels of polynuclear aromatic hydrocarbons (PAHs) in drinking water by high performance liquid chromatography (HPLC) fluorescence detection typically requires large water samples and lengthy extraction procedures. The detection itself, although selective, does not give compound identity confirmation. Benchtop gas chromatography/mass spectrometry (GC/MS) systems operating in the more sensitive selected ion monitoring (SIM) acquisition mode discard spectral information and, when operating in scanning mode, are less sensitive and scan too slowly. The selectivity of hyperthermal surface ionisation (HSI), the high column flow rate capacity of the supersonic molecular beam (SMB) GC/MS interface, and the high acquisition rate of time-of-flight (TOF) mass analysis, are combined here to facilitate a rapid, specific and sensitive technique for the analysis of trace levels of PAHs in water. This work reports the advantages gained by using the GC/HSI-TOF system over the HPLC fluorescence method, and discusses in some detail the nature of the instrumentation used.

Vein patching reduces neointimal thickening associated with prosthetic graft implantation

PURPOSE

Modified anastomotic techniques utilizing autogenous vein-cuffs or patches have been devised with the hope of improving prosthetic graft patency. The mechanisms of the presumed improvement in patched anastomoses have never been elucidated and remain speculative. We characterized the healing response of the Taylor vein patch in prosthetic arteriovenous fistulae in a canine model of intimal hyperplasia.

METHODS

Six adult dogs underwent placement of bilateral (6 patched, 6 control) 4-mm diameter expanded polytetrafluoroethylene loop femoral artery-vein fistulae. Serial duplex ultrasound examinations confirmed graft patency until explant at 6 weeks. Differential light microscopy with computerized image analysis was performed on serial 5-microm sections. Intimal thickness through the venous anastomosis and outflow veins of Taylor patch and control (nonpatched) grafts were compared. Cell type-specific immunocytochemical antibody stains for smooth muscle cells (alpha SMC actin) and endothelial cells (von Willebrand factor) were performed.

RESULTS

Eleven of 12 grafts remained patent for 6 weeks, 1 control graft thrombosed. Mean duplex-derived peak systolic velocities of patched (96 cm/sec) and control (108 cm/sec) grafts were similar. Microscopy revealed more intimal pannus anastomotic suture line ingrowth in controls (mean thickness = 178 microm) than Taylor patched grafts (mean 147 microm, p = 0.0002). Significantly less intimal thickening was present in the outflow vein of patched (mean thickness = 90 microm) versus control grafts (mean 195 microm, P <0.0001). The intima maintained a single cell layer of vWF + endothelial cells, while the majority of the cells comprising the lesion expressed alpha SMC actin.

CONCLUSION

Perianastomotic pannus is primarily composed of intimal smooth muscle cells. Neointimal thickening is significantly reduced in prosthetic arteriovenous fistulae created with the Taylor vein patch in a canine model. Reduction in perianastomotic intimal thickening may explain the reported clinical improvement in prosthetic bypass graft patency when modified with vein patch techniques.

Treatment of patients with venous thromboembolism and malignant disease: should vena cava filter placement be routine?

PURPOSE

It has been proposed that inferior vena cava filter placement should be the initial treatment of deep venous thrombosis (DVT) or pulmonary embolus (PE) in patients with coexisting malignant disease. We have chosen instead to selectively place filters only in patients with either a contraindication to anticoagulation therapy or a subsequent complication from anticoagulation therapy. The treatment efficacy and mortality rates in patients with concomitant malignant disease and venous thromboembolism using this approach was determined.

METHODS

We retrospectively reviewed all patients at our institution with malignant disease in whom venous thromboembolism developed between August 1991 through August 1996 and identified 166 patients with PE (n = 8), DVT (n = 147), and DVT/PE (n = 11). Of these patients, 138 (83.1%) were initially treated with anticoagulation therapy, and 28 (16.9%) had primary filter placement because of contraindications to anticoagulation therapy (10 for intracranial tumors, 11 for recent or upcoming operations, 6 for recent hemorrhage, and 1 for a malignant bloody pericardial effusion).

RESULTS

Thirty-two (23%) of the 138 patients who initially underwent anticoagulation therapy subsequently required a filter for the following reasons: bleeding (n = 15, 10.9%); recurrent thromboembolism (n = 6, 4.3%); heparin-induced thrombocytopenia (n = 1, 0.7%); and perceived high risk for bleeding with continued anticoagulation therapy (n = 11, 8%). Both bleeding and recurrent thromboembolism developed in 1 patient. Sixty patients (36%) received filters. No major technical complications occurred from filter placement. Major recurrent thromboembolic complications developed in 10 patients: DVT (n = 6, 10%), PE (n = 2, 3.3%), inferior vena cava thrombosis and phlegmasia cerulea dolens (n = 1, 1.7%), superior vena cava thrombosis (n = 1, 1.7%). Venous gangrene developed in 1 patient with DVT. The 1-year actuarial survival rates for patients treated with filter and anticoagulation therapy were 35% and 38%, respectively (P = NS).

CONCLUSION

In summary, our experience suggests that 64% of patients with malignant disease and venous thromboembolism are effectively treated with anticoagulation alone; 17% require primary filter placement for standard indications, and an additional 19% require subsequent filter placement because of complications (primarily bleeding) or failure of anticoagulation therapy. Although technical complications of filter placement are low, serious life-threatening or limb-threatening thromboembolic complications developed in 17% of patients. Survival was poor in all patients, regardless of treatment. These data support a conservative approach of routine anticoagulation therapy with selective filter placement.

Finding DNA regulatory motifs within unaligned noncoding sequences clustered by whole-genome mRNA quantitation

Whole-genome mRNA quantitation can be used to identify the genes that are most responsive to environmental or genotypic change. By searching for mutually similar DNA elements among the upstream non-coding DNA sequences of these genes, we can identify candidate regulatory motifs and corresponding candidate sets of coregulated genes. We have tested this strategy by applying it to three extensively studied regulatory systems in the yeast Saccharomyces cerevisiae: galactose response, heat shock, and mating type. Galactose-response data yielded the known binding site of Gal4, and six of nine genes known to be induced by galactose. Heat shock data yielded the cell-cycle activation motif, which is known to mediate cell-cycle dependent activation, and a set of genes coding for all four nucleosomal proteins. Mating type alpha and a data yielded all of the four relevant DNA motifs and most of the known a- and alpha-specific genes.

A regional pedal ischemia scoring system for decision analysis in patients with heel ulceration

PURPOSE

The objective of this study was to evaluate patients undergoing operative debridement for heel ulceration and to categorize pedal perfusion and its influence on therapeutic alternatives.

METHODS

Patients with heel ulceration were stratified by arteriography and graded I (patent posterior tibial, PT), II (occluded PT/reconstituted from peroneal), III (PT reconstituted from dorsal pedal), IV (no PT reconstitution but visible heel tributaries), and V (avascular heel).

RESULTS

From May 1992 through January 1997, 23 patients underwent operative treatment for 25 heel ulcers. The heel ischemia score stratified patients into two groups: 1, revascularization/debridement (71% grades I to III, 29% grade IV, 0% grade V); and 2, free tissue transfer with or without revascularization (100% grades IV, V). Cumulative functional limb salvage was 91% (BP), 60% (BP + TT), and 81% (TT) at 24 months (P = 0.15 log rank).

CONCLUSION

The heel ischemia score may direct treatment of heel ulceration by identifying patients who will need vascularized tissue transfer early in their treatment regimen.

Flow-dependent pulmonary vasodilation during acute unilateral pulmonary artery occlusion in Jungle Fowl

Giant Jungle Fowl previously were shown to be highly resistant to the onset of pulmonary hypertension syndrome (PHS, ascites) under conditions that induce a substantial incidence of PHS in broiler chickens. In the present study, lightly anesthetized, clinically healthy 12- to 13-wk-old male Giant Jungle Fowl maintained a lower respiratory rate, a similar hematocrit, and superior arterial blood gas values when compared with 6-wk-old male broilers. Giant Jungle Fowl weighed less than broilers (1,860 +/- 19 vs 2,788 +/- 63 g, respectively) and had equivalent absolute values for pulmonary arterial pressure, cardiac output, and pulmonary vascular resistance. Acute unilateral pulmonary artery occlusion in Giant Jungle Fowl doubled the pulmonary vascular resistance and forced the right ventricle to propel a sustained 60% increase in blood flow through the vasculature of the unoccluded lung. A transient increase in pulmonary arterial pressure initially was required to overcome the vascular resistance of the unoccluded lung; however, flow-dependent vasodilation gradually reduced the pulmonary vascular resistance and permitted pulmonary arterial pressure to return toward control levels. Unilateral pulmonary artery occlusion also triggered an immediate reduction in the partial pressure of oxygen in arterial blood, and the gradual return of pulmonary arterial pressure toward control levels did not eliminate this ventilation-perfusion mismatch, which has been attributed to blood flowing too rapidly through the unoccluded lung to permit diffusive gas equilibration. The inherent capacity for flow-dependent pulmonary vasodilation may reduce the susceptibility of Giant Jungle Fowl to PHS by reducing the increment in pulmonary arterial pressure required to propel an elevated blood flow through the lungs.

The thrombosed arteriovenous graft: an endovascular model for vascular surgeons

Arteriovenous dialysis grafts are the most commonly implanted prosthetic grafts. Thrombectomy with selective graft revision is traditional therapy for occlusions, but patency is minimally prolonged. Stenoses are determined by tactile feedback from an embolectomy catheter and lack of prograde and retrograde bleeding. An objective method for studying the graft and inflow and outflow tracts that permits appropriate endoluminal or surgical correction is described. This approach is appealing because: (i) the current approach is inadequate; (ii) it offers an objective, quantitative method to determine frequency and severity of critical stenoses within the failed access graft; (iii) remote and perigraft stenoses can be treated at the same setting; and (iv) it promotes the development of endovascular skills by surgeons in a high-volume, low-risk setting.

Identification of predictors for lower extremity vein graft stenosis

BACKGROUND

The cause of intrinsic vein graft stenosis, which develops in at least 20% of infrainguinal autogenous bypass grafts during the intermediate follow-up interval, is unknown. We performed standard duplex surveillance of all lower extremity bypass grafts and evaluated the potential of comorbid patient risk factors that might predict development of vein graft flow disturbance or high-grade graft stenosis.

METHODS

Patients with at least 6 months of postoperative duplex surveillance were identified through our vascular registry. The association of clinical and hemodynamic profiles of graft performance were compared with specific patient risk factors, including demographics, cigarette smoking, antihypertensive medical therapy, type and quality of conduit, degree of ischemia, bypass run-off, and presence of infection, using stepwise logistic regression analysis.

RESULTS

Ninety-three patients (55 male, 38 female; mean age 69) underwent 100 infrainguinal bypasses. Twenty-six high-grade graft stenoses (>70%) were identified in 26 patients during follow-up (mean 21 months) by graft-flow peak systolic velocity (PSV) >300 cm/sec on more than one duplex examination, and were electively revised. Graft flow disturbances (180 cm/sec >PSV <300 cm/sec) were identified in an additional 13 grafts (6 regressed, 7 observed). The need for graft revision was associated with an early graft flow disturbance (P = 0.02), or drop in ankle-brachial index >0.15 (P = 0.03), and the use of an alternative conduit in 13 of 100 grafts (P = 0.04). Only smoking was associated with the development of a duplex detected graft flow disturbance during follow up (P = 0.03).

CONCLUSION

Grafts with early flow disturbances warrant close duplex surveillance to identify graft-threatening stenosis. Risk factors that may predict future lower extremity bypass graft stenosis are smoking and the use of alternative bypass conduits.

Anti-VLA-4 antibody reduces intimal hyperplasia in the endarterectomized carotid artery in nonhuman primates

PURPOSE

Recently, very late antigen-4 (VLA-4) has been shown to mediate initial monocyte adhesion and migration to the injured artery. We hypothesized that blocking monocyte adhesion using a specific monoclonal antibody against VLA-4 may reduce intimal hyperplasia.

METHODS

Bilateral carotid endarterectomies were performed in eight adult baboons. Among them, five animals received an intravenous bolus injection of anti-VLA-4 antibody (3 mg/kg) during surgery and again after 2 weeks. Three animals underwent bilateral carotid endarterectomies and served as untreated control subjects. Specimens were harvested at 4 weeks and subjected to morphometric analysis, cell proliferation assay, and immunostaining for macrophages.

RESULTS

All of the endarterectomized arteries were patent except for one in the treated group. The number of macrophages in the intimal tissues was significantly reduced in the treated arteries compared with that in the control vessels (15.78 +/- 3.05 cells/section versus 33.50 +/- 6.13 cells/section; p < 0.001). The cell proliferation rate was significantly lower (p < 0.001) in the treated vessels (2.88% +/- 1.07%) compared with the control vessels (4.89% +/- 0.77%). The intimal area at the endarterectomized sites of carotid arteries was significantly less (p < 0.05) in the group treated with the anti-VLA-4 antibody (1.10 +/- 0.68 mm2) than in the control group (2.00 +/- 0.52 mm2).

CONCLUSION

These data show that blocking monocyte adhesion by use of an anti-VLA-4 antibody significantly reduces the number of intimal macrophages, intimal cell proliferation, and intimal hyperplasia in injured carotid arteries in baboons. This study supports a central role for macrophages in the development of intimal hyperplasia and may suggest a new therapeutic strategy to prevent clinical restenosis.

Reduced blood flow accelerates intimal hyperplasia in endarterectomized canine arteries

The purpose of this study was to evaluate a technique that accelerates intimal hyperplasia by reduction of blood flow. Bilateral endarterectomies were performed in both femoral and carotid arteries in six dogs. One week later, all animals underwent banding of an artery distal to the injured region to reduce the blood flow by 50%. The contralateral injured arteries served as controls. At 11 weeks, the specimens were harvested and analyzed. Five of 12 (42%) of the flow-restricted arteries and nine of 12 (75%) of the non-flow-restricted arteries were patent at 11 weeks (P<0.05). Marked stenotic intimal hyperplastic lesions developed in the flow-restricted arteries (69% stenosis) as compared with the non-flow-restricted arteries (37% stenosis). Mean(s.d.) intimal thickness, intimal areas, and intimal/medial area ratio were 0.52(0.19) mm, 3.17(1.11) mm2, and 1.12(0.33)%, respectively, in the flow-restricted arteries. Their counterparts in the non-flow-restricted arteries were 0.21(0.09) mm, 1.70(1.09) mm2, and 0.58(0.14)%, respectively (P<0.05). Extracellular matrix comprised 48% of total intimal volumes in the flow-restricted arteries. Cell proliferation and occluded arteries were also characterized. These data demonstrate that reduction of blood flow significantly accelerated intimal hyperplasia and occlusion rates in endarterectomized arteries. Advanced intimal hyperplastic lesions (>50% stenosis) possess a high extracellular matrix content. This new animal model is a reliable generator of advanced stenotic lesions in a relatively short time period and can be used to study biologic mechanisms of stenosis and evaluate therapeutic interventions.

Boundary layer infusion of nitric oxide reduces early smooth muscle cell proliferation in the endarterectomized canine artery

To evaluate the direct effect of nitric oxide (NO) on vascular smooth muscle cell (SMC) proliferation in vivo, we used an expanded polytetrafluoroethylene (ePTFE)-based local infusion device to deliver an NO donor, proline/NO (PROLI/NO), to the luminal boundary layer of endarterectomized artery and the distal anastomosis of the graft in a canine model. Once delivered to the blood, PROLI/NO releases NO by a mechanism involving pH-dependent decomposition. Six dogs underwent bilateral femoral artery endarterectomies. ePTFE infusion devices, blindly primed with PROLI/NO to one artery or proline to the contralateral vessel, were anastomosed proximal to the injured segments so that each animal served as its own control. PROLI/NO or proline was continuously delivered for 7 days from an osmotic reservoir, through the wall of the graft infusion device. Euthanasia was carried out at 7 days, and the processed specimens were blindly analyzed for SMC proliferation at both graft anastomoses and endarterectomized segments by a bromodeoxyuridine index assay. All dogs survived with no clinical side effects. In comparing the treated and control vessels, NO released from PROLI/NO significantly reduced SMC proliferation by 43% (13.24 +/- 1.24% versus 23.24 +/- 1.01%, P = 0.004) at the distal anastomoses and by 68% (10.58 +/- 1.63% versus 25.17 +/- 3.39%, P = 0.007) at endarterectomized segments. However, there was no significant difference in blood flow measurements between treated and control arteries (56.25 +/- 6.50 ml/min versus 46.50 +/- 3.20 ml/min, P = 0.094). These data demonstrate that local boundary layer infusion of NO released from PROLI/NO significantly reduces SMC proliferation in injured arteries with no effect on regional blood flow. This study suggests a new strategy to inhibit early SMC proliferation in injured arteries and probably to control intimal hyperplastic lesion formation in the manipulated vessels.

Time-course study of intimal hyperplasia in the endarterectomized canine artery

In an effort to characterize intimal hyperplastic lesions, we have undertaken a time-course study in a canine endarterectomy model of intimal hyperplasia. Twenty dogs underwent surgical endarterectomies of the carotid arteries. A total of 23 of 27 (85%) injured arteries were patent, which consisted of 6, 8, 5, and 4 arteries found to be patent at 1, 2, 5, and 11 weeks, respectively. Measurable intimal thickening developed at 1 week (0.08 +/- 0.01 mm) and at 2 weeks (0.13 +/- 0.02 mm), maximized at 5 weeks (0.29 +/- 0.03 mm), and subsided at 11 weeks (0.21 +/- 0.01 mm) after injury. Endothelial cells covering intimal hyperplastic tissues were seen only at 11 weeks. The intimal cell proliferation rate reached a maximum of 24% at 1 week, decreased dramatically at 2 weeks, and remained at low levels but higher than baseline levels at 5 and 11 weeks. Extracellular matrix (ECM) content accounted for 29% of total intimal volume at 1 week after endarterectomy and increased to 37, 40, and 47% at 2, 5, and 11 weeks, respectively. These data demonstrate that maximum intimal cell proliferation occurs at 1 week and maximum intimal hyperplasia at 5 weeks after arterial injury. Intimal ECM content increased with time after injury throughout the duration of this study. The uniform and consistent intimal lesion that was established in this large animal model is clinically relevant and can be used to study cellular and molecular mechanisms of restenosis and to evaluate therapeutic interventions.

Endoscopic venous valve transplantation with a valve-stent device

In this report we describe the outcome of a 6-week study of the valve-stent device in a goat model. Six female goats underwent endoscopic subcutaneous harvest of a valve-containing segment of external jugular vein. This segment was sutured inside a 10-mm Wallstent (Schneider Inc., USA), and the device was compressed and loaded into a 12 Fr. introducer sheath and deployed through a venotomy into the contralateral external jugular vein. The animals were anticoagulated for 1 week and euthanized at 6 weeks. Flow studies, manual strip test, and angioscopic evaluation were performed prior to sacrifice. All six valve-stents were patent at harvest by Doppler flow studies, and five of six were competent as demonstrated by the manual strip test. At angioscopic evaluation, the valves were open. Gross and histologic examination revealed intact valve leaflets in five specimens. This technique is a minimally invasive approach to valve harvest and transplantation with a valve-stent device. We have demonstrated that valve-stent can remain patent and competent for up to 6 weeks. This technique may have potential application in venous valvular incompetence.

Optic neuropathy preceding acute retinal necrosis in acquired immunodeficiency syndrome

OBJECTIVE

To describe the clinical course of varicella-zoster optic neuropathy preceding acute retinal necrosis in patients with acquired immunodeficiency syndrome.

DESIGN

Case series.

SETTING

Two tertiary care centers in San Diego, Calif, and London, England.

PATIENTS

Three human immunodeficiency virus-positive men with previous cutaneous zoster infection, optic neuropathy, and necrotizing retinitis.

RESULTS

All patients had an episode of zoster dermatitis treated with acyclovir. Visual loss consistent with an optic neuropathy ensued, followed by typical herpetic retinitis. The cause of visual loss was not suspected to be varicella-zoster until after the retinitis occurred. Despite aggressive medical treatment, 4 of 6 eyes progressed to retinal detachment.

CONCLUSIONS

Varicella-zoster may cause an optic neuropathy in patients with acquired immunodeficiency syndrome, especially in those with previous shingles. A high index of suspicion is necessary to establish the diagnosis and begin early antizoster treatment.

Recombinant mitotoxin basic fibroblast growth factor-saporin reduces venous anastomotic intimal hyperplasia in the arteriovenous graft

BACKGROUND

The plant cytotoxin saporin (SAP) is a potent ribosome-inactivating protein. When conjugated to basic fibroblast growth factor (FGF2), it selectively kills proliferating cells that have upregulated FGF receptors. In this study, we evaluated the effect of the recombinant chimeric mitotoxin rFGF2-SAP on venous anastomotic intimal hyperplasia, a major cause of failure of arteriovenous (AV) grafts.

METHODS AND RESULTS

Recently designed expanded polytet-rafluoroethylene-based local infusion devices were implanted bilaterally as femoral AV conduits in six dogs. The venous anastomoses were the sites of continuous delivery of rFGF2-SAP (2.7 micrograms.kg-1.d-1) to one side and vehicle (4.6 microL.kg-1.d-1) as control to the contralateral side for 14 days. All animals survived, and all grafts were patent. Liver enzyme levels and histological analyses of liver, kidneys, and brain were normal, indicating the absence of systemic toxicity. Morphometric measurements and measurements of cell proliferation by bromodeoxyuridine index analysis were performed at both arterial and venous anastomoses. There were no significant differences between the treated grafts and the control grafts in intimal hyperplasia and intimal cell proliferation at the arterial anastomoses. In contrast, rFGF2-SAP reduced intimal thickness by 32%, intimal area by 40%, and cell proliferation index by 33% at the treated venous anastomoses compared with the control venous anastomoses (P < .05).

CONCLUSIONS

These data demonstrate that local infusion of rFGF2-SAP significantly reduces venous anastomotic intimal hyperplasia and cell proliferation without systemic toxicity. This study suggests a new strategy for reducing intimal hyperplasia by the selective killing of proliferating smooth muscle cells with a potent chimeric mitotoxin through a novel local infusion device.

Normothermic renal artery perfusion: a comparison of perfusates

Hypothermia and preservative perfusates have been used to decrease ischemic renal injury. This study was performed to identify the preservative function of perfusates independent of the effects of hypothermia. Rats underwent 45 minutes of renal ischemia. Rectal and renal parenchyma temperatures were monitored and maintained within 1 degree C of normal. Perfusates were University of Wisconsin solution (UW), Euro-Collins solution, normal saline solution, and Ringer's lactate solution. A nonperfused ischemic control and a nonischemic control group were also evaluated. Parameters evaluated included serum creatinine and blood urea nitrogen levels, renal ischemic injury grade, renal weight, and gross appearance of the injured kidney. Rats treated with UW solution were found to have a significantly lower creatinine, blood urea nitrogen, and injury grade than the other three perfused groups. The external gross appearance of the UW-treated kidneys was normal, whereas that of the other groups demonstrated moderate to severe injury. Although the mean right/left renal weight difference of the UW-treated group was lower than that of the other three groups, this was not statistically significant. Under normothermic conditions in rats, UW solution affords significant renal protection from ischemia. Euro-Collins, normal saline, and Ringer's lactate solutions display no significant protective effect.

Transgraft infusion of heparin to prevent early thrombosis of expanded PTFE grafts in canine femoral veins

Recently we designed an expanded polytetrafluoroethylene (ePTFE)-based local infusion device that delivers therapeutic agents directly through the graft wall in the region adjacent to the upstream anastomosis, thereby achieving a high drug concentration downstream along the graft-blood interface. In this study we evaluated the effects of infusing heparin by this method on graft patency and neointimal hyperplasia in a canine model of femoral vein replacement. Five dogs underwent bilateral femoral vein replacement with the device. In each case one graft was infused with continuous heparin (48 U/kg/day) while the contralateral control graft received phosphate-buffered saline solution for 14 days. All heparin-treated grafts were patent and all control grafts were thrombosed at 14 days. There was no significant difference in systemic activated partial thromboplastin time among samples taken preoperatively, at 48 hours, and at 14 days of implantation (p > 0.5). There was no significant difference in neointimal hyperplasia between the upstream and downstream anastomoses in heparin-treated grafts. These data demonstrate that the transgraft infusion of heparin preserved venous ePTFE graft patency without measurable systemic anticoagulation. Thus this approach may represent an attractive strategy for maintaining patency of synthetic venous grafts.

Renal artery perfusion modifies ischemia/reperfusion injury

Renal ischemic and reperfusion injury is a significant complication of major aortic and renovascular surgery. The delivery of a preservative agent just prior to reperfusion of an ischemic kidney may decrease the reperfusion injury. The purpose of this study was to evaluate the effects of renal artery perfusates delivered at the termination of an ischemic period. Five groups of rats were evaluated. All rats underwent left nephrectomy. The right kidney was made ischemic for 45 min by occlusion of the renal artery and vein. Ischemic control animals had no renal artery perfusion. Nonischemic control animals had no renal vessel occlusion or perfusion. The other three groups were perfused during the final 4 min of ischemia with one of the following: normal saline (NS), phosphate-buffered saline (PBS), or anti-ICAM-1-antibody (mAb). The blood urea nitrogen (BUN), serum creatinine (Cr), and renal histopathologic injury of each group were compared. The ischemic control group had significantly better renal function than the group perfused with NS or mAb at 72 hr. There was no significant difference between the ischemic control and PBS groups in renal function or morphologic injury. It is concluded that none of the perfusates in the study had protected the kidney from ischemic and reperfusion injury. NS delivered in this manner was injurious to the kidney.

Local infusion of FGF-saporin reduces intimal hyperplasia

The recent conjugation of the potent ribosome-inactivating protein saporin (SAP) with basic fibroblast growth factor (FGF2) to form recombinant (r)FGF2-SAP permits increased selectivity of this mitoxin for cells exhibiting upregulated FGF receptors. Systemic administration of rFGF-SAP in therapeutic doses, however, may be associated with significant liver toxicity. In this blinded study, we used a local boundary layer infusion approach to increase local drug concentration while minimizing the risk of side effects. Six dogs underwent bilateral carotid endarterectomies. Expanded polytetrafluoroethylene infusion devices, blindly primed with rFGF2-SAP to one artery or vehicle to the contralateral vessel, were anastomosed proximal to the injured segments so that each animal served as its own control. rFGF2-SAP (2 microgram/kg/day) or vehicle (5 microl/hr) was continuously delivered for 14 days from an osmotic reservoir, through the wall of the graft infusion device. Euthanasia was carried out at 14 days and the processed arteries were blindly analyzed for intimal thickening and cellular proliferation. All dogs survived until sacrifice with no clinical side effects. Liver function tests at euthanasia were not significantly altered when compared to baseline values. Intimal area in rFGF2-SAP-treated vessels averaged 0.31 +/- 0.10 mm2 versus 0.57 +/- 0.24 mm2 in the control segments (P = 0.02), a relative reduction of 46%. Cell proliferation, however, was not significantly different at 14 days postendarterectomy (2.40 +/- 1.31% vs 2.39 +/- 0.45%). From this study it can be concluded that locally delivered rFGF2-SAP reduces intimal hyperplasia and that the boundary layer infusion strategy is an effective means for delivering high local drug concentration while minimizing systemic drug effects.

Peripheral vascular complications of aortic dissection

BACKGROUND

The incidence and management of peripheral vascular complications of aortic dissection is unsettled.

PATIENTS AND METHODS

Peripheral vascular complications of spontaneous aortic dissection were examined in a 5-year retrospective review. Patients who had peripheral vascular complications were categorized as group A; those without as group B.

RESULTS

Thirty-eight major vessels were affected in 18 patients. No patient underwent a peripheral vascular procedure for complications of the carotid, subclavian, celiac, mesenteric, or renal arteries. Three patients underwent femorofemoral bypass for acute iliofemoral occlusion due to dissection. A fourth patient had repair of an iliac aneurysm that developed as a complication of chronic dissection. The mortality rate was 17% for group A, 9% for group B, and 10% overall. Following repair of the aortic dissection, the majority of the peripheral vascular complications resolved.

CONCLUSIONS

Peripheral revascularization is infrequently required in aortic dissection following primary dissection repair.