Implementation of student experiential learning in health & wellbeing in a large university setting

Background

Healthy UCD is a health promotion initiative in University College Dublin (UCD). Working together with university academic staff, we have provided opportunities for graded experiential learning for students in health and wellbeing-related courses. This abstract presents how experiential learning was implemented in the 2020/21 academic year.

Objectives

The first objective was to provide a public health nutrition learning opportunity to MSc in Clinical Nutrition & Dietetics students through the design, implementation and evaluation of UCD Healthy Eating Week in Autumn 2020. Secondly, we aimed to facilitate the running of a wellbeing event by BSc Sport & Exercise Management students with Healthy UCD as their client in Spring 2021. The students had the additional challenge this year of delivering the content online.

Results

MSc Clinical Nutrition & Dietetics students utilised Healthy UCD's website and social media channels to deliver a virtual Healthy Eating Week. Infographics, videos, articles and podcasts were produced which generated 1,000 website visits and reached over 3,000 on social media. Most students involved agreed that the event was successful (95%) and that they were sufficiently supported by Healthy UCD and their tutors (65%). BSc Sport & Exercise Management students devised and delivered a week-long event titled “Wellbeing Your Way”, creating wellbeing seminars and live exercise classes with each receiving an average of 460 views. The students reported gaining valuable experience of the responsibilities of running a professional event and operating as a team.

Conclusions

These examples of experiential learning for credit demonstrate how university campus health promotion teams can facilitate student learning and simultaneously reap the benefit for university faculty and students. The key requirements are committed academic engagement and supported students.

Key messages

University campus health promotion provides excellent opportunities for experiential learning. Health promotion practical experience can have benefits both for students and for the university.

Congenital Vascular Malformations: General Treatment Principles

The era where surgical excision alone was the sole treatment of venous malformation (VM) is now over. A multidisciplinary approach that utilizes both traditional surgical therapy and endovascular therapy is now the standard of care. Endovascular therapy utilizing primarily both embolization therapy and sclerotherapy is the treatment of choice for surgically ‘inaccessible' VM lesions. Surgical therapy of VM lesions has been shown to be more effective when combined with supplemental endovascular therapy.

Congenital Vascular Malformations: General Diagnostic Principles

Venous malformation (VM) is the most common congenital vascular malformation (CVM), which usually presents as a single lesion in the majority of cases. It also presents as a mixed lesion combined with other CVMs (e.g. lymphatic malformation and arteriovenous malformation [AVM]). Therefore, the diagnosis of VM should include an appropriate work-up, to not only confirm and characterize the VM as either extratruncular or truncular but also to diagnose or exclude the presence of other CVMs. The diagnosis of VM can be made safely using non-invasive to minimally invasive studies, which can also distinguish VM from infantile haemangioma. Invasive studies, such as venography and arteriography, are generally reserved for therapeutic planning and diagnosis of more virulent CVMs (e.g. AVM). The work-up of VM should include a complete assessment of the extent and severity of the primary VM lesion. In addition, its embryologic origin, as well as its haemodynamic characteristics and secondary effects should also be determined.

Terminology and Classification of Congenital Vascular Malformations

Venous malformation (VM) is a congenital vascular malformation (CVM) that develops along the venous system through the various stages of embryogenesis. Older terminology and classification were often misleading and confusing. A newer classification system has emerged that is based on advances in the study of these conditions and is useful in contemporary management. The Hamburg classification was introduced after reappraisal of older terminology and has become the standard system for contemporary classification, which is based on anatomical, pathological and embryological criteria.

Current status of lymphatic reconstructive surgery for chronic lymphedema: it is still an uphill battle!

The goal of reconstructive lymphatic surgery is to restore normal lymphatic function to "cure" permanently the lymphedematous limb in patients with lymphedema. In reality, reconstructive surgery remains an adjunctive treatment at best, with its current indication being refractory lymphedema in patients treated with complex decongestive therapy (CDT) alone. The role of reconstructive lymphatic surgery remains controversial and is far from being accepted as standard independent therapy because of multiple reasons. However, reconstructive surgery appears to be most effective in controlling the progression of lymphedema during the early stages when the paralyzed lymph vessels are still able to function and recover. Our experience in reconstructive surgery has shown that improved long-term results are dependent on prolonged patient compliance with maintenance CDT and the prevention and treatment of infection. To better understand the role of reconstructive surgery in the management of chronic lymphedema, well-constructed clinical trials based on well-organized multicenter studies with similar protocols are mandated. For the future, it remains the only possible treatment method capable of providing a cure.

Autotransplantation of solitary kidney with renal artery aneurysm treated with laparoscopic nephrectomy and ex vivo repair: a case report

INTRODUCTION

Renal artery aneurysms (RAA) are extremely rare clinical entities with associated morbidities including hypertension and rupture. Although most RAA can be treated with in vivo repair or endovascular techniques, these may not be possible in patients with complex RAA beyond the renal artery bifurcation. We report a case of RAA in a patient with a solitary kidney that we treated successfully by extracorporeal repair and autotransplantation and the 2-years follow-up.

CASE REPORT

A 64-year-old woman with a history of right nephrectomy for renal cell carcinoma presented with RAA found on routine computed tomography (CT). Preoperative workup demonstrated a 2.2 × 2.1 × 3-cm aneurysm in the distal left renal artery that was not amendable to in vivo or endovascular repair. The patient underwent a laparoscopic-assisted left nephrectomy, ex vivo renal artery aneurysm repair, and autotransplantation. She did well postoperatively and in clinic follow-up was found to have a creatinine of 1.2 mg/dL at the end of 2 years and stable blood pressure control.

DISCUSSION

This patient with RAA in her solitary kidney was successfully treated with laparoscopic-assisted nephrectomy, ex vivo repair, and autotransplantation. Her creatinine was stable postoperatively despite absence of a second kidney.

Reconstructive surgery for chronic lymphedema: a viable option, but

The aim of the paper is to assess the efficacy of reconstructive lymphatic surgery in the treatment of chronic lymphedema via retrospective analysis. Lymphovenous anastomotic surgery (LVAS) or free lymph node transplant surgery (FLTS) was performed on 32 patients who failed to respond to complex decongestive therapy (CDT) alone for a minimum of a one-year period. In LVAS, three patients with good compliance among 19 were able to maintain initial improvement through the four-year follow-up period. All three had secondary lymphedema in clinical stage II. In FLTS, among 13 patients, three compliant patients with the secondary lymphedema in clinical stage II kept initial improvement through the four-year follow-up. In conclusion, reconstructive lymphatic surgery (LVAS and FLTS) appears to be more effective in secondary lymphedema versus primary lymphedema when performed in the early stages. Patient compliance to maintain CDT postoperatively remains the most critical factor in maintaining durable long-term results. FLTS seems to have an additional risk involved to the donor lymph node harvest and a limited role compared to LVAS. Further extended study on FLTS is required to demonstrate its efficacy compared with LVAS.

Embryological background of truncular venous malformation in the extracranial venous pathways as the cause of chronic cerebro spinal venous insufficiency

The truncular venous malformation (VM) represents an embryologically defective vein where developmental arrest has occurred during the vascular trunk formation period in the 'later stage' of the embryonic development. A relatively simple truncular VM lesion such as a venous web at the hepatic venous outlet causes portal hypertension giving a profound damage/impact to the liver. A similar condition involving the head and neck venous system may cause chronic cerebro-spinal venous insufficiency (CCSVI) and may be involved in the development or exacerbation of multiple sclerosis.

Arterio-venous malformation: how much do we know?

Arterio-venous malformation (AVM) is a congenital vascular malformation that is neither a venous malformation nor a haemangioma. An AVM is a potentially life-threatening and limb-threatening lesion, especially the 'fistulous' truncular form due to its unique embryological and haemodynamic characteristics. AVM treatment requires an early aggressive approach, one that is careful and based on a thorough assessment of the risks and benefits associated with the treatment plan. A successful treatment strategy requires an accurate assessment of the AVM taking into account the extent, severity and progression of the lesion. This is critical in order to minimize the morbidity associated with the currently available therapies. A multidisiciplinary approach that integrates endovascular and surgical therapy can substantially improve the treatment results seen in patients with AVMs. Preliminary treatment of a fistulous AVM with coil embolization is essential in order to minimize associated morbidity and to alter the lesion haemodynamics from a high-flow lesion to a low-flow lesion that is more amenable to subsequent, definitive management with ethanol or NBCA glue embolo/sclerotherapy.

Supplemental surgical treatment to end stage (stage IV-V) of chronic lymphedema

AIM

When the lymphedema reaches to its end stages, the complex decongestive therapy (CDT) and/or compression therapy become less effective and increased risk of systemic/general sepsis to become potentially life threatening condition.

METHODS

To improve its clinical management, excisional surgery was performed on 22 patients for their 33 limbs in the end stage of lymphedema as a supplemental therapy, and its efficacy was retrospectively analyzed. Diagnosis was made by radionuclide lymphoscintigraphy and basic laboratory studies (e.g. ultrasonography, magnetic resonance imaging). Twenty-two patients (mean age: 46 years; 3 male and 19 female; 5 primary and 17 secondary) submitted to the excisional surgery on 33 limbs (unilateral: 11; bilateral: 22). Surgery was indicated by further progression of the disease with recurrent sepsis despite adequate antibiotics therapy. A modified Auchincloss-Homan's operation was used to excise grotesquely disfigured soft tissue with advanced dermato-lipo-fibrosclerotic change. The normal limb contour was re-established to allow proper postoperative therapy. Postoperative CDT and compression therapy were mandatorily implemented in all cases.

RESULTS

A postoperative assessment of the treatment results, at 12 months showed an overall improvement in 28 of the 33 limbs: substantial improvement on the condition of limb function and quality of life (QOL), and local and/or systemic sepsis. Eighteen patients with good compliance to maintain the postoperative CDT showed much improved clinical results and QOL through the first interim assessment (24 months).

CONCLUSION

Excisional surgery at the end stage of lymphedema seems to provide substantial improvement of clinical condition and QOL only when mandated postoperative CDT/compression therapy is well kept.

Congenital vascular malformations: general treatment principles

The era where surgical excision alone was the sole treatment of venous malformation (VM) is now over. A multidisciplinary approach that utilizes both traditional surgical therapy and endovascular therapy is now the standard of care. Endovascular therapy utilizing primarily both embolization therapy and sclerotherapy is the treatment of choice for surgically 'inaccessible' VM lesions. Surgical therapy of VM lesions has been shown to be more effective when combined with supplemental endovascular therapy.

Terminology and classification of congenital vascular malformations

Venous malformation (VM) is a congenital vascular malformation (CVM) that develops along the venous system through the various stages of embryogenesis. Older terminology and classification were often misleading and confusing. A newer classification system has emerged that is based on advances in the study of these conditions and is useful in contemporary management. The Hamburg classification was introduced after reappraisal of older terminology and has become the standard system for contemporary classification, which is based on anatomical, pathological and embryological criteria.

Distal venous patch improves results in PFTE bypasses to tibial arteries

In recent years, the management of limb-threatening ischemia has involved the use of distal bypasses to vessels beyond the popliteal trifurcation. Excellent patency rates and limb salvage data are achieved through the use of autologous long saphenous vein. However, an increasing number of patients in need of tibial bypass do not have adequate saphenous vein due to previous procedures, thrombophlebitis, or inadequate vein. In such cases alternative conduits have been proposed including lesser saphenous vein, arm vein, composite veins, composite vein with polytetrafluoroethylene (PTFE), and PTFE with or without a distal arteriovenous fistula. Unfortunately these alternative conduits have not resulted in equivalent results when used for distal bypass to tibial arteries. Several authors have reported upon the use of venous tissue at the distal anastomosis in the form of cuffs, collars, and boots to improve the results of prosthetic grafts in this challenging patient population. These techniques have been proposed as an option for revascularization in patients without adequate saphenous vein in an attempt to obtain limb salvage. The purpose of this review is to examine some of those techniques and focus on distal vein patch configuration with its perceived advantages and drawbacks.

Asthma care by nurse practitioners in the United States

PURPOSE

To survey nurse practitioners (NPs) in the United States on their level of input to asthma care prior to enrolling in The National Asthma and Respiratory Training Centre (NARTC) specialist asthma education program in the UK.

DATA SOURCES

Responses of 134 (66%) of the 202 NPs who self-selected for enrollment in the NARTC program on a preliminary questionnaire.

CONCLUSIONS

Nearly all (133 or 99%) currently work with asthmatics and 122 (91%) prescribe asthma drugs. Only 92 (69%) measure peak flow(PF), 84 (63%) check inhaler technique, 76 (57%) teach use of a home PF meter and diary, and 63 (47%) provide written self-management plans on any regular basis. Many have not established follow-up procedures (56 or 42%), or evaluated their asthma management practices (55 or 41%).

IMPLICATIONS FOR PRACTICE

Successful asthma management requires correct medication, systematic follow-up, patient education, and self-management. Specialist asthma training should encourage practitioners to combine effective drug usage with a long-term preventative approach.

Common femoral artery ligation and local debridement: a safe treatment for infected femoral artery pseudoaneurysms

PURPOSE

The management of infected femoral artery pseudoaneurysms (IFAPs) is difficult and controversial. Use of synthetic or autologous conduit during arterial revascularization in these cases is complicated by the presence of sepsis and unavailability of autologous venous conduit. We present the results of common femoral artery (CFA) ligation and local drainage with debridement for the treatment of IFAP.

METHODS

A retrospective chart review of six consecutive patients from 1995 to 1999 who presented with IFAP from intravenous drug abuse was performed. Inpatient records, anesthesia records, and outpatient clinic charts were reviewed. All patients were men with right-sided lesions. All six patients abused heroin, and five (83%) abused heroin and cocaine. All six patients had a duplex ultrasound scan, and five (83%) patients had a digital subtraction angiogram to confirm the clinical diagnosis. Proximal vascular control was achieved retroperitoneally through an oblique suprainguinal incision. After vascular isolation and test clamping of the distal external iliac artery (EIA), the pedal pulses were examined with continuous wave Doppler scan. If a Doppler signal was present, this was followed with CFA ligation and local drainage and debridement of the IFAP.

RESULTS

Pain at injection site and fever with chills were present in five (83%) and three (50%) patients, respectively. A pulsatile groin mass and thigh or leg edema were present in five (83%) patients. Three patients (50%) had a palpable pedal pulse, and all six had a Doppler signal over a pedal artery at presentation. The mean white cell count was 15.6 thousand per cubic millimeter (range, 9.2-19.3). All patients had a Doppler signal over a pedal artery after distal EIA/CFA test occlusion and ligation. None of the patients required an amputation, and all six patients regained their preoperative ambulatory status. The mean follow-up period was 25 months. Two patients had mild claudication (5-6 blocks) at 18 months and 2 years after surgery. All six patients received drug rehabilitation, but they admitted to drug abuse after surgery and rehabilitation.

CONCLUSION

CFA ligation and local debridement are safe treatment modalities for IFAP, if there is an intraoperative Doppler signal over a pedal artery during test occlusion of the distal EIA/CFA. CFA ligation avoids the use and therefore the risk of synthetic conduit infection, because there is a high incidence of postoperative drug injection despite aggressive drug rehabilitation.

Homocysteine accelerates endothelial cell senescence

In this study we demonstrate that exposure of cultured endothelial cells to homocysteine significantly accelerates the rate of endothelial senescence. Examination of telomere length demonstrates that homocysteine increases the amount of telomere length lost per population doubling. The effects of homocysteine on both senescence and telomere length are inhibited by treatment with the peroxide scavenger catalase. Chronic exposure of endothelial cells to homocysteine also increases the expression of two surface molecules linked to vascular disease, intracellular adhesion molecule-1 (ICAM-1) and plasminogen activator inhibitor-1 (PAI-1). Interestingly, the level of expression of both ICAM-1 and PAI-1 correlates with the degree of endothelial senescence. Taken together, these results suggest that homocysteine accelerates the rate of cellular senescence through a redox-dependent pathway. In addition, it suggests that chronic oxidative stress in the vessel wall may hasten the rate of senescence and that the senescent endothelial cell may in turn be pro-atherogenic.

Angioscopic evaluation of an endoluminal aortic graft: the first clinical experience

PURPOSE

Balloon aortoscopy has been described for viewing aortic endoluminal anatomy and guiding aortic stent placement in animals. We report the first clinical use of this technique to visually inspect the proximal portion of a 1-year-old endovascular aortic graft, its proximal fixation stent, and its relationship to the renal arteries.

METHODS

The aortoscope is a modified fiber-optic endoscope that is fitted over the lens with a transparent, saline-filled balloon for blood displacement. Its performance was evaluated in a 62-year-old woman who had a Parodi-type Dacron/modified Palmaz stent endoluminal graft implanted to exclude an infrarenal aortic aneurysm in 1994. One year later, during an angioplasty procedure for symptomatic left subclavian and left common iliac artery stenoses, the 1-year-old endoluminal graft was inspected with the balloon-tipped angioscopic assembly.

RESULTS

Introduced via the left brachial artery, the aortoscope provided a panoramic view of the endoluminal surface through the solution-filled balloon. The endoluminal aortic graft was clearly identified, as were both renal artery orifices proximal to the graft. The surface of the proximal stent was smooth and without exposed metal. No complications occurred with the angioscopy technique.

CONCLUSIONS

Aortic angioscopy can be used to evaluate endoluminal aortic grafts and endoluminal anatomy. It provides clear, magnified views that may be useful for guiding precise placement and assessing the function and healing of endoluminal devices in the aorta.

Arterial intimal flaps: a comparison of primary repair, aspirin, and endovascular excision in an experimental model

The optimal management for traumatic arterial intimal injuries is unresolved. Three therapeutic options were compared in an experimental model employing a standard intimal flap created in 51 canine superficial femoral arteries. Group 1 (14 arteries) underwent resection with end-to-end repair. Group 2 (19 arteries) received acetylsalicylic acid (ASA) and observation only. Group 3 (21 arteries) underwent endovascular excision of the flap with angioscopic guidance. Control intimal flaps (18 arteries) were created and observed without further intervention. Patency in group 1 (primary repair) and group 2 (ASA) was 100%; the patency in both was significantly (p < 0.05) greater than in the controls, which was 67%. Patency in group 3 (endovascular excision) was 79%. Residual luminal defects were observed in only 8% of the arteries repaired primarily, but in 76% of the aspirin-treated arteries. Residual luminal defects following endovascular excision were present in 53% of the arteries remaining patent. Although resection and primary repair (group 1) provided better results than observation alone (control), addition of ASA (group 2) also sustained patency. However, a high incidence of residual intimal defects occurred, the natural history of which is unknown. While endovascular excision (group 3) may become a feasible alternative, current technology provided inferior patency with frequent residual intimal defects. These results suggest that observation alone supplemented with antiplatelet medication (ASA) may be adequate treatment, but longer follow-up is necessary for confirmation.

Dose-dependent smooth muscle cell proliferation induced by thermal injury with pulsed infrared lasers

BACKGROUND

Recently, laser-heated and radio frequency-heated balloon angioplasty techniques have been proposed as a means to treat or minimize dissection and elastic recoil but have been associated with a high rate of clinical restenosis. Similarly, pulsed laser angioplasty techniques proposed to minimize thermal injury while ablating obstructing atheroma have failed to reduce clinical restenosis. Because "hot balloon" and pulsed laser angioplasty create both mechanical and thermal injury, it has been difficult to discern the cause of the smooth muscle cell (SMC) proliferation resulting in restenosis and whether such magnitude of proliferation is predictable and dose related. This study was undertaken to explore these issues.

METHODS AND RESULTS

Localized thermal lesions accompanying efficient ablation were created with a pulsed Tm:YAG laser in nine rabbit aortas, which consistently led to a focal proliferation of SMC that filled the ablated region by 4 weeks. Transcutaneous Ho:YAG pulsed laser irradiation at multiple independent sites of 24 central rabbit ear arteries without ablation led to brief approximately 30 degrees C thermal transients and thermal damage to the artery wall resulting in significant neointimal proliferation by 3 weeks and a mean cross-sectional narrowing of 59 +/- 17% at a dose of 390 mJ/mm2. Acute and chronic responses to varying total energy deposition were studied by histology after the rabbits were killed at 2 hours to 4 weeks. Arterial segments midway between laser injuries were unaffected and served as internal controls. Neointimal proliferation at 3 weeks after laser injury exhibited a clear dose dependence. Mean cross-sectional narrowing increased from 34 +/- 10% to 85 +/- 15% as laser fluence increased from 240 mJ/cm2 to 640 mJ/cm2 (r = 0.84). Similarly, cross-sectional narrowing caused by SMC neointimal proliferation increased from 20 +/- 10% to 77 +/- 17% for a fixed surface irradiation as the depth of the most superficial arterial media decreased from 600 microns to 330 microns (r = 0.94).

CONCLUSIONS

Thermal injury to the arterial wall is a potent stimulus for SMC proliferation and may necessitate reduction in laser or thermal energy used for angioplasty. Moreover, a dose-response relation exists between the degree of thermal injury and SMC proliferative response. Hence, this technique could be used as a practical model of restenosis suitable for screening therapies for inhibition of SMC proliferation.

Role of heparin in reducing skeletal muscle infarction in ischemia-reperfusion

Heparin continues to be recommended in the clinical management of limb ischemia to prevent extension of distal vascular thrombosis and increased rates of limb loss. However, heparin may also be responsible for reduced skeletal muscle injury. Although its mechanism of action has not been fully evaluated, we have investigated the ability of heparin to minimize skeletal muscle injury associated with the ischemia-reperfusion syndrome in an in vivo canine gracilis muscle model. Our findings demonstrated a significant reduction in the amount of skeletal muscle infarction, microvascular permeability, and H+ ion accumulation cumulation after preischemic heparinization. Diffuse intravascular coagulation also has been observed in observed in this model which may be prevented or reduced by the anticoagulant properties of heparin when administered prior to ischemia. However, heparin's protective effect may be independent of its anticoagulant activity. Heparin is a polycomponent drug with non-anticoagulant properties which may serve to reduce cellular injury during ischemia and reperfusion in several different ways. Microvascular injury is decreased by the restoration of normal intimal negative charge and through the binding and resultant inactivation of histamine, bradykinin and other vasoactive amines. Heparin inhibits the complement cascade which is known to determine ischemic infarct size. Other factors of importance in determining the extent of skeletal injury include neutrophil activation, chemotaxis, enzyme release, and free oxygen radical generation, all of which are decreased or modulated by heparin. Heparin is a complex substance and much more remains to be learned about its anticoagulant and nonanticoagulant properties as well as its protective effects on skeletal muscle injury in ischemia-reperfusion syndrome.

Somatostatin and analogs lack splanchnic vasoconstrictive effects in anesthetized pigs

Due to an apparently selective vasoconstrictive effect on the splanchnic circulation, somatostatin (SRIF) has been advocated for the treatment of variceal hemorrhage. The present study was designed to compare and contrast the systemic and splanchnic hemodynamic effects of SRIF and two of its long-acting analogs (SMS 201,995 and L 363,568) with those of Pitressin. Anesthetized pigs were subjected to laparotomy for placement of an electromagnetic flowmeter on the main trunk of the superior mesenteric artery (SMA). Systemic hemodynamic parameters of arterial blood pressure and cardiac output were monitored with thermodilution catheters. Portal venous blood was collected for measurement of plasma levels of SMS 201,995 and L 363,568 and for determination of gastrin levels during infusion of the latter analog. Experimental drugs were administered via an aortic cannula in a range (5-10 mg/kg bolus and 5-10 mg/kg/min continuous infusion) of dosages. At the higher dosages, SRIF, SMS 201,995, and L 363,568 decreased SMA blood flow (mean% +/- SD) 5.6 +/- 2.2, 1.6 +/- 4.4, and 8.0 +/- 3.8 after 10 min. None of the values achieved significance when compared to variation in baseline determinations. Pitressin (0.25 units, intravenously) produced a consistent and highly significant (P less than 0.001) reduction-in SMA flow after 5 min. Pharmacologic levels of SMS 201,995 and L 363,568 were reliably achieved in portal blood and the latter produced significant reduction (P less than 0.05) in portal venous levels of gastrin. SRIF and its long-acting analogs produced no significant splanchnic nor systemic hemodynamic effects in this model.

Local tumor recurrence after curative resection for rectal cancer. A ten-hospital review

Local tumor recurrence rates after curative rectal cancer surgery with the end-to-end anastomosis stapler (EEA) are reportedly high. Therefore, a retrospective review in ten Yale-affiliated hospitals was undertaken to establish the outcome of surgical resection for rectal cancer in this patient population. Of those 373 patients who had had curative resections, 192 (52 percent) were abdominoperineal resections (APR); 105 patients (28 percent) had restorative resections with sutured anastomoses, and the EEA stapler was used in 76 patients (20 percent). There was an equal distribution of tumors in the various Dukes' stages in all three procedures. Local tumor recurrence was: APR 19 percent, SUT 17 percent, and EEA 24 percent, but local tumor recurrence was more frequent after EEA than APR for tumors 7 to 10 cm from the anal verge (32 vs. 13 percent, respectively, P less than 0.05), and the time to recurrence was least in EEA patients. It is concluded that local tumor recurrence is higher than expected for all three procedures and that the EEA stapler was associated with a greater risk of local tumor recurrence. These findings are attributed to surgeon-related technical operative factors rather than to the nature of the tumors themselves.

Pyrolytic carbon, porous implants, and the fibrin adhesive system

The bone implant interface for Pyrolite and titanium alloy was evaluated. The effects of a fibrin adhesive system (FAS) on the interface was also compared. Fixation of the Pyrolite and porous titanium implants was observed to occur in the 4-week period of the study with minimal fibrous tissue encapsulation. The ultimate interfascial shear strength for bone-Pyrolite interface was attained at 4 weeks. No adverse effect with utilization of the FAS could be identified. Further investigation into the use of Pyrolite and the FAS in foot surgery is anticipated.

Preservative cytotoxicity to cultured corneal epithelial cells

Cultured human and rat corneal epithelial cells with 51Cr incorporated were used as a model to test the cytolytic action of four common preservatives. Benzalkonium chloride, chlorohexidine and thimerosol were all found to lyse greater than 40% cells when incubated for fifteen minutes at concentrations in clinical use in topical ophthalmic medications. Chlorobutanol is the only preservative tested which has a low level of cytotoxicity (10%) and which, under these conditions, can be considered a safe preservative using cytolytic activity as the means of criteria.

Isolation and partial characterization of pancreatic polypeptide-like material in the brain of the blowfly Calliphora vomitoria

Using 10(6) flies (5 kg of heads) a pancreatic polypeptide-like material has been partially purified from the blowfly Calliphora vomitoria. The isolated material was eluted on Sephadex G-50 similarly to bovine pancreatic polypeptide and had an RF on polyacrylamide-gel electrophoresis that was identical with that of the bovine hormone. The material diluted linearly and showed parallelism with bovine standards in a bovine pancreatic polypeptide immunoassay. In specificity controls the immunoreactivity was not abolished by trasylol and no cross-reactivity was discerned in assay for glucagon, proangiotensin and cyclic AMP. These data suggest that the pancreatic polypeptide material in the brain of the blowfly has close structural similarity to the mammalian hormone.