Prevention of graft-versus-host disease in mice using a suicide gene expressed in T lymphocytes

Alloreactive T cells present in a bone marrow transplant are responsible for graft-versus-host disease (GVHD), but their depletion is associated with impaired engraftment, immunosuppression, and loss of the graft-versus-leukemia effect. We developed a therapeutic strategy against GVHD based on the selective destruction of these alloreactive T cells, while preserving a competent T-cell pool of donor origin. We generated transgenic mice expressing in their T lymphocytes the Herpes simplex type 1 thymidine kinase (TK) suicide gene that allows the destruction of dividing T cells by a ganciclovir treatment. T cells expressing the TK transgene were used to generate GVHD in irradiated bone marrow grafted mice. We show that a short 7-day ganciclovir treatment, initiated at the time of bone marrow transplantation, efficiently prevented GVHD in mice receiving TK-expressing T cells. These mice were healthy and had a normal survival. They maintained a T-cell pool of donor origin that responded normally to in vitro stimulation with mitogens or third party alloantigens, but were tolerant to recipient alloantigens. Our experimental system provides the proof of concept for a therapeutic strategy of GVHD prevention using genetically engineered T cells.

Long-term prognostic significance of dobutamine echocardiography in patients with suspected coronary artery disease: results of a 5-year follow-up study

OBJECTIVES

This study sought to assess the long-term prognostic utility of dobutamine stress echocardiography in predicting fatal and nonfatal cardiac events.

BACKGROUND

Although dobutamine stress echocardiography has improved sensitivity and specificity for detection of coronary artery disease, little is known of its predictive value for long-term cardiac events. Therefore, we followed up 120 consecutive patients who underwent dobutamine echocardiography for suspected coronary disease from March 1989 to August 1991.

METHODS

All patients presenting for coronary angiography for chest pain were eligible for recruitment. Follow-up was 100% complete at 5 years (range 3.0 to 6.1). Cardiac events were defined as cardiac death or nonfatal myocardial infarction or the need for coronary revascularization (coronary angioplasty or bypass surgery).

RESULTS

Positive (n = 78) and negative (n = 42) dobutamine test groups differed in their rates of coronary artery bypass graft surgery (37.2% vs. 9.5%, p < 0.001, respectively) and mortality. Of 26 total deaths, 22 occurred in the group with positive dobutamine test results (28% vs. 9.5%, p < 0.018); all 7 cardiac deaths occurred in this group as well (9% vs. 0%, p < 0.045). By multivariate regression analysis, positive results on dobutamine echocardiography remained independently predictive of future cardiac death after left ventricular ejection fraction and other clinical variables were accounted for.

CONCLUSIONS

A positive finding on dobutamine echocardiography is an independent predictor of long-term cardiac mortality, whereas a negative finding confers a significantly reduced likelihood of cardiac death as much as 5 years from initial testing. We conclude that dobutamine stress echocardiography can be used to predict which patients with suspected coronary artery disease are at low risk for cardiac death and do not require concurrent nuclear or invasive testing.

Influence of local delivery of the protein tyrosine kinase receptor inhibitor tyrphostin-47 on smooth-muscle cell proliferation in a rat carotid balloon-injury model

Smooth-muscle cell proliferation in response to arterial injury represents an important etiologic factor in restenosis after angioplasty. Tyrphostin-47, a protein tyrosine kinase inhibitor, inhibits smooth-muscle cell proliferation in vitro. In this study tyrphostin-47 was incorporated into matrixes to determine whether prolonged local delivery would result in a reduction of neointimal proliferation after arterial injury in a rat carotid balloon-injury model. A polymer matrix (polylactic polyglycolic acid copolymer and pluronic gel F-127, mean matrix weight 7.83 +/- 0.39 mg) was loaded with tyrphostin-47 (25% w/w). Release studies demonstrated delivery of 11% of the incorporated drug over a 21-day release period. In cell culture, tyrphostin-47 released from the polymer matrix produced a reduction in smooth-muscle cell proliferation (p < 0.0007). Balloon denudation injury of the left common carotid artery of 34 animals was performed. In 12 animals, polymer matrixes containing tyrphostin-47 were wrapped around the injured arteries to provide prolonged drug delivery (estimated dosage 28 micrograms/kg/24 hr); in 10 animals a polymer matrix without tyrphostin-47 was implanted; and in 12 animals only balloon injury was performed. The mean neointimal cross-sectional areas, luminal areas, and intima/media ratios were not significantly different among animals receiving local treatment with tyrphostin-47, sham polymer after injury, or balloon injury without polymer implantation. We conclude that despite inhibition of smooth-muscle cell proliferation by tyrphostin-47 in vitro, sustained local delivery of this tyrosine kinase inhibitor does not result in a reduction of neointimal proliferation in the rat carotid injury model.

Telemedicine in the '90s

BACKGROUND

Telemedicine emerged in the 1950's and declined during the 1970s and 1980s. Its reemergence in the 1990s generally tracks communications technological advances. Though its major applications have traditionally been confined to rural and under-served areas, telemedicine's application grows on a nearly daily basis. Broadly defined, telemedicine describes the transfer of medical data over facsimile or telephone and video conferencing. Though traditionally applied to patient care, it is increasingly being employed in the area of physician education. The Florida Medical Association's computer CME developments are one example.

Spontaneous dissection of the internal carotid artery: a nineteen-year clinical experience

PURPOSE

This article reviews our experience with internal carotid artery dissection (ICAD), evaluates the usefulness of Duplex scanning in diagnosis, provides current recommendations for treatment, and better defines long-term prognosis.

METHODS

The records from 1976 to 1995 of 24 patients who had 28 ICAD were reviewed. All diagnoses were confirmed by arteriography. Presenting symptoms, diagnostic tests, clinical management, and outcome were examined.

RESULTS

Nine patients had visual symptoms or headache, 10 had transient focal neurologic symptoms (TIA), and five had stroke. Five of the 19 who had visual symptoms or TIA had a stroke before the diagnosis of ICAD. Seventeen patients who had 19 ICAD underwent a Duplex scan at the time of presentation. Duplex scan identified 18 arterial abnormalities consistent with ICAD (sensitivity, 95%). Three patients died from stroke during the initial hospitalization. Of the 21 who survived, 12 were treated with anticoagulation therapy, six with aspirin, and three with aspirin and anticoagulation therapy. None of the 21 patients had a subsequent stroke. Six patients subsequently had an operation for residual occlusive disease or aneurysm. The mean duration of follow-up was 9.3 years. Two patients developed contralateral ICAD. During follow-up, 19 arteries were studied with Duplex scan, and seven had no residual evidence of ICAD.

CONCLUSIONS

Patients who have ICAD often have prodromal symptoms before stroke. If diagnosed early, treatment with anticoagulation may prevent stroke. Duplex scans are accurate for defining carotid abnormalities consistent with ICAD and for indicating the need for arteriography. Patients should undergo a follow-up Duplex scan to identify contralateral ICAD.

Management of angiogram positive lower gastrointestinal hemorrhage: long term follow-up of non-operative treatments

After positive mesenteric angiography for massive lower gastrointestinal hemorrhage, one is faced with a localized bleeding site and the therapeutic options of embolization, vasopressin infusion, observation, or operation. This review was designed to determine long term outcomes of angiographically controlled bleeding. All cases of mesenteric angiography for hemorrhage performed over a twelve year period were reviewed, with focus on those treated non-operatively. A total of 37 patients had angiographically localized bleeding distal to the ligament of Treitz. Twenty-one patients were controlled with vasopressin, embolization, or spontaneous cessation. Only three patients had recurrent bleeding, at one month, one year, and eight years. No patients died from recurrent bleeding. Five patients died without any further bleeding; mean time to death was 2 years. Twelve patients had no further bleeding at a mean follow-up of 2.6 years. Bleeding controlled by any angiographic measure, was followed by recurrent bleeding in 14% without the need for operative intervention.

Arbutamine echocardiography: efficacy and safety of a new pharmacologic stress agent to induce myocardial ischemia and detect coronary artery disease. The International Arbutamine Study Group

OBJECTIVES

This study sought to determine the efficacy and safety of arbutamine echocardiography in inducing myocardial ischemia and detecting coronary artery disease.

BACKGROUND

Exercise and pharmacologic stress echocardiography are clinically accepted techniques for detecting coronary artery disease. Arbutamine is a new synthetic beta-adrenoceptor agonist developed specifically as a stress agent. Arbutamine is delivered by a new computerized drug delivery device that adjusts the rate of drug infusion according to the patient's heart rate response during stress testing.

METHODS

The sensitivity of arbutamine echocardiography was determined in 143 patients who had coronary artery disease documented by coronary angiography. A subset of these patients (n = 114) also underwent exercise echocardiography. The specificity, or normalcy, of arbutamine echocardiography was determined in 54 patients considered to have a low likelihood of coronary artery disease.

RESULTS

Among those patients who had both stress test results, the incidence of inducing myocardial ischemia (new or worsening wall motion abnormalities) was 79% (95% confidence interval [CI] 69% to 86%, n = 98) for arbutamine and 77% (95% CI 67% to 85%, n = 98) for exercise echocardiography. The sensitivity of detecting coronary artery disease (ischemia or rest wall motion abnormality) was 87% (95% CI 79% to 93%, n = 101) for arbutamine and 83% (95% CI 74% to 90%, n = 101) for exercise echocardiography. The specificity (normalcy) of arbutamine echocardiogrpahy was 96% (95% CI 87% to 100%, n = 52). Arbutamine was well tolerated, and there were no serious adverse events.

CONCLUSIONS

Arbutamine echocardiography is an effective and safe pharmacologic stress test technique for diagnosing or excluding the presence of coronary artery disease. The ability of arbutamine stress to induce myocardial ischemia, detectable by echocardiography, was comparable to that for exercise.

Long-term management of diverticulitis in young patients

PURPOSE

This study was designed to determine the natural history of documented diverticulitis that resolves after treatment with intravenous antibiotics and bowel rest in patients under the age of 50.

METHODS

Records of 40 patients aged 50 or under who were hospitalized with the diagnosis of acute diverticulitis between 1980 and 1984 were reviewed to obtain data regarding how the diagnosis was made. Patients successfully treated with antibiotics were contacted five to nine years after their attack and surveyed via telephone questionnaire about symptoms, recurrent attacks, and surgical interventions.

RESULTS

A total of 40 patients were included in the study. Ten patients (25 percent) required surgery during initial admission, and 30 patients were discharged with resolution of their symptoms after treatment with intravenous antibiotics and bowel rest. A five-year to nine-year follow-up was obtained on patients treated medically, one-third of whom underwent operation for diverticulitis during this period, and two-thirds of whom did not require surgery during the follow-up period. All operations were elective with single-stage resections.

CONCLUSION

Based on our data, we do not recommend surgery in this population after a single episode of diverticulitis that resolves after treatment with antibiotics.

Treatment of recurrent femoral or popliteal artery stenosis after percutaneous transluminal angioplasty

PURPOSE

This study was undertaken to compare repeat percutaneous transluminal angioplasty (rPTA), arterial reconstruction, and noninvasive therapy for treatment of patients with recurrent stenosis after PTA of the superficial femoral or popliteal artery.

METHODS

From 1983 to 1993, 93 patients were treated for recurrent femoropopliteal stenosis. Indication for treatment was claudication in 72 patients, rest pain in 9, and ischemic ulcer in 12. Thirty-six patients (38%) were treated with arterial bypass, 35 (38%) with rPTA, and 22 (24%) with exercise and medication. Patients were monitored with clinical examination, ankle-brachial indexes, and duplex scanning. Follow-up ranged from 6 to 110 months (mean 42 months).

RESULTS

With life-table analysis, the clinical and hemodynamic success of patients treated with rPTA was 41% at 1 year, 20% at 2 years, and 11% at 3 years. For patients treated with arterial bypass, the primary graft patency rate was 84%, 72%, and 72% at 1, 2, and 3 years, respectively. The secondary graft patency rate was 94%, 88%, and 88% at the same intervals. All patients with patent grafts were symptom free. All 22 patients treated with noninvasive therapy continued to have symptoms, but none required amputation during follow-up (range 6 to 108 months). Overall, patients with claudication did better than those treated for rest pain or an ischemic lesion after either rPTA or arterial bypass, but no other variable was statistically significant in predicting outcome.

CONCLUSIONS

This study finds that arterial bypass is safe and more effective than rPTA in treating patients with recurrent stenosis. Preoperative evaluation is unable to select patients likely to benefit from rPTA. Repeat PTA should be reserved for patients with limited life expectancy or contraindications to operation.

Endoscopic localization of colon cancers

In order to determine the accuracy of endoscopic localization of colon cancers, the endoscopic location was compared to the actual location at the time of operation in 320 patients who underwent resection of intraabdominal colon cancer between 1983 and 1988. The endoscopic location was correct in 86% of the cases. There were 44 endoscopic errors, including seven missed cancers. One-third of all endoscopic errors occurred when the tumor was in the cecum. We conclude that endoscopy is an accurate method of localizing colon cancers. However, with the advent of laparoscopic surgery and the loss of the ability to palpate the colon, the 14% of endoscopic errors take on a greater importance and additional means for localizing tumors should be pursued in selected cases.

Large bowel obstruction caused by incarcerated inguinal hernia: report of three cases

We report two patients with left colonic obstruction and one patient with cecal obstruction caused by incarceration in inguinal hernias. None of the patients had colonic malignancies within the hernial sacs. Reduction of the hernias was followed by resolution of the bowel obstruction and successful hernial repair in all patients.

The influence of diabetes mellitus on the risk of abdominal aortic surgery

Risk factors and postoperative complications of 153 diabetics (DM) who underwent an abdominal aortic operation for occlusive disease or an intact aneurysm from 1964 through June, 1988 were compared with 970 nondiabetics (nonDM) who underwent similar operations during the same time period. Heart disease, hypertension, cerebrovascular disease, and renal insufficiency were more prevalent in diabetics. Postoperatively, DM had a statistically significant increase in the incidence of myocardial infarction (DM 5.2%, nonDM 2.1%, P = .0434) and wound infection (DM 2.6%, nonDM 0.6%, P = .0359). The incidence of renal failure (DM 1.3%, nonDM 1.0%), stroke (DM 2.0%, nonDM 0.6%), and death (DM 3.9%, nonDM 2.9%) was higher in diabetics, but the differences were not statistically significant (P = NS). Operative mortality was greater for patients operated on for aneurysm (DM 5.3%, nonDM 3.2%) than for patients operated for occlusive disease (DM 3.3% versus nonDM 2.7%). Diabetics treated with insulin or oral agents had a higher complication rate than diabetics treated with diet alone or nondiabetics (insulin 13.0%, oral 13.4%, diet 4.2%, nonDM 8.6%). This study finds that diabetic patients can undergo an abdominal aortic operation with operative mortality comparable to that of nondiabetics. Diabetics have more postoperative complications than nondiabetics, but only myocardial infarction and wound infection are of statistical significance. Diabetics treated with insulin or oral agents have more complications than do diabetics treated by diet alone or nondiabetics.

Hemosuccus pancreaticus from intraductal rupture of a primary splenic artery aneurysm

Hemosuccus pancreaticus--blood entering the gastrointestinal tract through the pancreatic duct--is a rare and elusive form of gastrointestinal bleeding. The most common cause is a splenic artery pseudoaneurysm caused by acute or chronic inflammation of the pancreas. We report the case of an 86-year-old woman who had recurrent gastrointestinal bleeding from erosion of an aneurysm of the splenic artery into the pancreatic duct. The lack of associated symptoms, equivocal endoscopic findings, and the rarity of this entity resulted in a delay in diagnosis. Nonresective treatment by ligation of the splenic artery proximal and distal to the aneurysm prevented any additional bleeding. Postoperative technetium sulfur colloid scanning demonstrated normal perfusion of the spleen. Only 16 cases of hemosuccus pancreaticus from primary splenic artery disease have previously been reported in the English-language literature (15 primary aneurysms, one medial disruption without an aneurysm). In contrast to cases caused by inflammatory pseudoaneurysms, splenic artery-pancreatic duct fistulas caused by primary aneurysms of the splenic artery should be treated without pancreatic or splenic resection, either with surgery or by embolization. In elderly patients with recurrent gastrointestinal bleeding of obscure source, the differential diagnosis should include the possibility of a ruptured aneurysm communicating with a viscus.

Comparison of dobutamine and exercise echocardiography for detecting coronary artery disease

There has been no study comparing the efficacy of dobutamine and exercise echocardiography in detecting coronary artery disease (CAD) or their physiologic effects at ischemic threshold in the same group of patients. To accomplish this, 52 patients presenting for coronary angiography underwent supine ergometer exercise and dobutamine echocardiography. Compared with angiography, the overall sensitivity of detecting CAD was 78% for exercise and 86% for dobutamine echocardiography (p = NS). The sensitivities of detecting patients with 1-, 2-, 3- and multivessel CAD with exercise echocardiography were 63, 80, 100 and 90%, respectively, and with dobutamine echocardiography 75, 90, 100 and 95%, respectively (p = NS, exercise vs dobutamine). The specificity of both tests was 87%. At ischemic threshold, heart rate was significantly lower with dobutamine than with exercise echocardiography (91 +/- 3 vs 114 +/- 3 beats/min; p < 0.001), systolic blood pressure was significantly lower with dobutamine testing (155 +/- 5 vs 176 +/- 6 mm Hg; p < 0.01), and rate-pressure product was significantly lower with dobutamine stress (14.1 +/- 0.7 vs 19.8 +/- 0.8 x 10(3) beats/min x mm Hg; p < 0.001). It is concluded that the efficacy of detecting CAD by exercise and dobutamine echocardiography is comparable, and the physiology at ischemic threshold of the 2 methods is significantly different and suggests a different means of inducing myocardial ischemia.

Tourniquet occlusion technique for tibial artery reconstruction

PURPOSE

Vascular clamps, vessel loops, and intraluminal occluding devices used to control tibial and pedal vessels can be injurious and may fail to occlude heavily calcified arteries. In an effort to prevent injury to these small arteries, we have investigated the safety and efficacy of thigh pneumatic tourniquet occlusion for distal vascular control during infrapopliteal reconstruction.

METHODS

During an 18-month period, 88 tibial or pedal arterial reconstructions were performed on 80 patients (mean age 75 years) by the tourniquet technique. Data regarding indications for operation, preoperative evaluation, intraoperative findings, surgical technique, and early outcome were recorded prospectively.

RESULTS

Sixty percent of patients were diabetic: 36% insulin dependent and 24% non-insulin dependent. The indications for operation were claudication in 6 (7%), ischemic ulcer in 24 (27%), rest pain in 25 (28%), and gangrene in 33 (38%) patients. Thirty-five percent of operations followed failed ipsilateral infrainguinal reconstructions. The peroneal artery was the target vessel in 38%, anterior tibial in 26%, posterior tibial in 23%, tibioperoneal trunk in 9%, and inframalleolar vessels in 4% of cases. Preoperative analog waveforms and ankle-brachial indexes were used to classify the tibial arteries as compliant, 49%; relatively noncompressible, 30%; and absolutely noncompressible, 9%. Twelve percent had no Doppler flow at the ankle level. At operation 36 of the target arteries (41%) had mural calcification. Tourniquet pressures of 200 to 400 mm Hg (mode 250 mm Hg) were applied from 13 to 55 minutes (mean 27.1 +/- 9.1 minutes). All patients were given systemic anticoagulants. In 19 limbs (22%) the tourniquet was used to occlude a patent superficial femoral artery above the proximal (inflow) anastomosis to either the superficial femoral artery (8%), the above-knee popliteal artery (5%), or the below-knee popliteal artery (9%). Hemostasis was adequate in all cases and no alternative occlusive devices were required. There were no significant complications attributable to the use of the pneumatic tourniquet.

CONCLUSION

Tourniquet occlusion simplifies the infrapopliteal dissection, lessens operating time, improves visualization of the distal anastomosis, and removes the potential for arterial injury to the target vessel. Arterial calcification and noncompressible tibial arteries do not contraindicate the use of thigh tourniquet occlusion. This technique is preferred for all patients undergoing tibial or pedal artery reconstruction.

Acute renal allograft dysfunction in the setting of deep venous thrombosis: a case of successful urokinase thrombolysis and a review of the literature

Acute renal allograft vein thrombosis is a rare but serious complication of renal transplantation. When occurring in the early posttransplant period it is usually associated with surgical complications and often results in the loss of the graft. At later stages, when graft function has stabilized, its development may then be associated with underlying disorders such as glomerulonephritis, immunosuppressive therapy, increased hematocrit, acute rejection, or extension of lower extremity venous thromboses. We report a case of acute allograft dysfunction occurring in the setting of extensive deep vein thrombosis. In our patient, thrombosis in the setting of acute graft tenderness and swelling, anuria, and an increasing creatinine strongly suggest a diagnosis of acute allograft renal vein thrombosis. We describe a successful reversal of acute renal failure through urokinase thrombolysis and review the current literature on the use of thrombolytic agents for the treatment of acute renal allograft vein thrombosis.

Does routine patch angioplasty after carotid endarterectomy lessen the risk of perioperative stroke?

From 1964 through 1991 we performed primary closure of the arteriotomy in 1173 patients and patch angioplasty in 506 patients after carotid endarterectomy. The decision to patch was made at the surgeon's discretion. In general a patch was used for small arteries. In the primary closure group 32 patients (2.7%) had a perioperative stroke and in the patch angioplasty group 17 (3.4%) had a stroke. The difference (2.7% vs. 3.4%) was not significant (p < 0.5275, Fisher's exact two-tailed test). A total of 240 arteries were closed with a vein patch and 11 (4.6%) of these patients had a stroke; 266 were closed with a synthetic patch (Dacron, 211; polytetrafluoroethylene, 55) and six of the patients had a stroke (2.3%). The difference in stroke rate between the vein and synthetic patch groups (4.6% vs. 2.3%) was not significant (p < 0.2159). Patch angioplasty cannot be shown to reduce the incidence of perioperative stroke. Late carotid patency was not studied. This study supports a policy of selective patch angioplasty based on arterial size rather than patching all carotid arteries. When a patch is used, we prefer filamentous Dacron as the patch material.

Open-label study of the safety and efficacy of naftifine hydrochloride 1 percent gel in patients with distal subungual onychomycosis of the fingers

Optimal topical therapy for distal subungual onychomycosis is not available. An open-label study was performed to determine the safety and efficacy of naftifine hydrochloride (Naftin) 1 percent gel in patients with this disorder of the fingers. Ten patients with culture-proven distal subungual onychomycosis were treated twice daily for six months with naftifine hydrochloride 1 percent gel. At monthly intervals, the target nail was trimmed, the nail bed debrided, and global clinical assessment recorded. Following months three, six, and eight (two months after treatment), the target nail underwent evaluation with potassium hydroxide wet mount and fungal culture. After six months of therapy, eight of ten patients showed negative results of fungal culture and eight of ten patients showed clinical improvement. Adverse effects were minimal and included mild peeling in two patients and mild fissuring with transient fingertip numbness in one patient.

Patellar tilt and subluxation in total knee arthroplasty. Relationship to pain, fixation, and design

Two hundred thirty-four primary total knee prostheses were evaluated with a 45 degrees merchant view to examine patellar position and fixation. Despite a standardized technique for obtaining roentgenographs, patellar position varied with leg position. Overall, 54.7% tracked centrally, 31.2% tilted, and 14.5% displaced. The incidence of these findings was the same whether the patella was domed or congruent. Neither pain scores nor fixation were affected by position. Postoperative tilt and displacement were more common in patellae that were tilted preoperatively. The incidence of postoperative tilt or displacement was not significantly different in knees in which a lateral release was performed. Patellar tilt in some patients seems inevitable despite careful technique because intraoperative tests are static and postoperative function is dynamic. This does not bode well for wear in a metal-backed patella. Tilt caused increased loading at the periphery of the component where most metal-backed prostheses have thin polyethylene.

Suicidality in hospitalized adolescents: relationship to prior abuse

The effects of admission status, prior abuse, and the frequency and duration of both physical and sexual abuse on measures of suicidality for a sample of 117 hospitalized adolescents were investigated. Having been abused was found to have a significant association with the number of previous suicide attempts and to interact with the variable of admission status in measures of suicide ideation.

Vascular complications of the intra-aortic balloon pump

The lower extremity complications of 100 consecutive patients who required the placement of an intra-aortic balloon pump (IABP) during a 3-year period were studied. Indications for the IABP included hypotension during cardiac catheterization (33%) or coronary angioplasty (13%), hemodynamic instability after open heart surgery (35%), unstable angina (5%), and cardiac arrest (14%). The incidence of IABP morbidity was 29%. Complications included ischemia (25%), bleeding (2%), lymph fistula (1%), and femoral neuropathy (1%). Twenty patients required 1 or more surgical interventions for lower extremity vascular complications. The majority of patients who underwent operation (70%) had significant pre-existing arterial occlusive disease. Local femoral artery reconstruction or repair was performed in 18 patients. Two patients had adjunctive bypasses. Continued IABP support was required in four patients after treatment of complications. One patient (1%) had an above-knee amputation. Limb ischemia was treated nonoperatively by removal of the IABP in five patients. Color-flow duplex scans were useful in distinguishing hematomas from pseudoaneurysms as well as for assessing femoral artery flow. We conclude that: (1) limb ischemia remains the primary complication of the IABP; (2) pre-insertion documentation of the severity of existing peripheral arterial disease by noninvasive studies may aid in the management of subsequent acute limb ischemia; (3) femoral artery thrombectomy or endarterectomy is usually sufficient for revascularization; and (4) noninvasive color flow studies are an important diagnostic tool in the nonoperative management of limb complications.

Effects of serotonergic agonists and antagonists on ganglion cells in the goldfish retina

Extracellular recordings were made from the isolated goldfish retina during superfusion with various serotonergic agonists and antagonists to determine the effects of these drugs on the maintained activity and response properties of the ganglion cells. Superfusion of the retina with serotonin (25-500 microM) increased the maintained activity of OFF-center ganglion cells and decreased the maintained activity of ON-center ganglion cells. In addition, serotonin also attenuated the excitatory responses to annular stimuli, suggesting a decrease in the strength of surround input to the ganglion cells. The effects of serotonin on OFF-center ganglion cells were mimicked by the nonselective 5-HT1 agonist 5-MeOT and the 5-HT1A receptor agonist 8-OH-DPAT, while only 5-MeOT mimicked the action of serotonin on ON-center ganglion cells. The effects of exogenously applied serotonin on the ganglion cells could be blocked by the mixed 5-HT1/5-HT2 receptor antagonist methysergide but not by the 5-HT2 receptor antagonist mianserin or the dopamine receptor antagonist haloperidol. These results support previous anatomical and biochemical evidence that serotonin functions in a neurotransmitter or neuromodulatory role in the teleost retina and suggest that serotonin may be involved in modulating the maintained activity and surround input to the ganglion cells. The results also indicate that two different types of receptors may mediate the actions of serotonin in the ON and OFF pathways, respectively.