Effect of metformin on clastogenic and biochemical changes induced by adriamycin in Swiss albino mice

Diabetes mellitus (DM) is a chronic disease that is characterized by deteriorating glycemic control. The disease is known to be caused by imbalance between reactive oxygen species (ROS) and antioxidant defense systems. Hyperglycemia is commonly observed in a wide variety of diseases, including cancer. Although, therapy against glycemic control, is used in all these diseases, the diabetic cancer patients are on additional therapy with anticancer drugs. The objective of present study was to study if Glucophage (metformin), a very popular antidiabetic agent can avert the mutagenicity and lipid peroxidation caused by adriamycin (ADR), which is a commonly used cytotoxic drug. The experimental protocol included oral treatment of mice with different doses (62.5, 125 and 250 mg/kg day) of metformin for 7 days. Some mice in each group were injected i.p. with ADR (15 mg/kg). In each case animals were killed, 30 or 24, 48 and 72 h after the last treatment and femurs were excised for cytological studies by micronucleus test. Additional experiments on estimation of glutathione (GSH) and malondialdehyde (MDA) were undertaken in blood and serum, respectively. Twenty-four hour after the treatment, blood from each mouse was collected from heart and preserved for analysis. The results obtained revealed that pretreatment with metformin: (i) reduced the ADR-induced frequency of micronuclei without any alteration in its cytotoxicity and (ii) protected against the ADR-induced increase and decrease of MDA and GSH, respectively. The exact mechanism of action is not known, however, the inhibition of ADR-induced clastogenicity and lipid peroxidation by metformin may be attributed to the antioxidant action of the latter. Our results demonstrate that metformin might be useful to avert secondary tumor risk by decreasing the accumulation of free radicals and inhibition of mutagenicity.

Outcome of allogenic SCT in patients with low left ventricular ejection fraction

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Background: High-dose therapy and allogeneic stem cell transplantation (allo SCT) is a potentially curative treatment for patients with hematologic malignancies. Due to a high risk of regimen-related toxicity, only patients with excellent organ-system function are considered eligible for this treatment. A low left ventricular ejection fraction (LVEF) of ≤ 45% is considered to be a major risk factor for post-transplant cardiac toxicity and nonrelapse mortality. However, several patients with advanced hematologic malignancies and low LVEF can potentially benefit from this therapy. To address this issue, we studied the incidence of cardiac toxicity and non-relapse mortality (NRM) in 56 patients with low LVEF undergoing allo SCT. Methods: We performed a retrospective analysis on 56 patients with impaired cardiac function, who underwent an allo SCT between January 2000 and February 2006 at our institution. Pre-transplant evaluation included bidimensional echocardiogram and an electrocardiogram. Cardiac toxicity was defined as congestive heart failure (CHF), atrial / ventricular arrhythmia or acute myocardial ischemia. Twenty-two patients received a myeloablative (16 busulfan-based, 6 TBI-based), while 34 patients received a fludarabine-based reduced-intensity preparative regimen. Results: Twenty-three patients (41%) received allo SCT from an unrelated donor. Acute leukemia was the reason for allo SCT in 32 (57%) patients. Baseline LVEF, within 30 days prior to allo SCT, ranged from 20 to 45%. After a minimum of 6-month follow up, cardiac toxicity was seen in 7 (12%) patients. That included CHF in 4 (7%) and atrial fibrillation (AF) in 4 (7%). One patient had both CHF and AF. There were no documented episodes of acute myocardial ischemia. Cumulative incidence of NRM at 100 days was 12%, none of the deaths being attributable to a cardiac cause. These were comparable to allo SCT performed in patients with normal LVEF. Age, degree of left vetricular dysfunction, type of transplant or the underlying disease did not emerge as significant predictors of post-transplant cardiac toxicity or NRM. Conclusions: Allogeneic SCT is feasible in patients with hematologic malignancies and low LVEF. A prospective study with stratification for cardiac risk factors is warranted in patients with low LVEF.

No significant financial relationships to disclose.

Studies on the cytological and biochemical effects of valerian in somatic and germ cells of Swiss albino mice

Valerian is widely known for its use as a sedative and an anti-anxiety drug in the folk medicine. Literature reports suggested valerian to induce genotoxicity in vitro (ECV304 cells) by reactive oxygen species-mediated mechanism; however, there are no reports on its genotoxicity and/or the epigenetic mechanism in vivo. In view of the folkloric significance, it was found worthwhile to (1) determine the genotoxic effects of valerian in somatic and germ cells of mice and (2) investigate the role of epigenetic mechanisms. The protocol included the oral treatment of mice with different doses (500, 1000 and 2000 mg/kg/day) of valerian for 7 days. The following experiments were conducted: (i) cytological studies on micronucleus test, (ii) cytogenetic analysis for meiotic chromosomes, (iii) cytological analysis of spermatozoa abnormalities, (iv) quantification of proteins and nucleic acids in testicular cells and (v) estimation of malondialdehyde (MDA) and nonprotein sulfhydryl (NP-SH) in hepatic and testicular cells. The treatment increased the frequency of micronuclei in the polychromatic erythrocytes (PCE) and decrease the ratio of PCE to normochromatic erythrocytes (NCE) in the femur. It caused aberrations in chromosomes of the testis and induced spermatozoa abnormalities. The concentration of nucleic acids was depleted in the testicular cells. These changes might be attributed to the epigenetic mechanisms as revealed by an increase in the concentrations of MDA and a decrease of NP-SH levels in hepatic and testicular cells observed in the present study. The observed changes may be ascribed to terpenoids (valepotriates) and flavonoids (6-methylapigenin and 2S(-)-hesperidin) present in valerian.

Studies on the reproductive, cytological and biochemical toxicity of Ginkgo Biloba in Swiss albino mice

Ginkgo biloba (an herbal product), used as a folkloric medicine in the treatment of dementia, was evaluated for its effects on reproductive, cytological and biochemical toxicity in male Swiss albino mice. The mice were treated with different doses (25, 50 and 100mg/kg/day) of the aqueous suspension of Ginkgo biloba for 90 days by oral gavage. The following parameters were evaluated: (1) reproductive organ weight; (2) motility and content of sperms; (3) spermatozoa morphology; (4) cytology of the testes chromosomes; (5) study on reproduction; (6) biochemical study on proteins, nucleic acids, malondialdehyde (MDA) and nonprotein sulfhydryl (NP-SH). The treatment caused significant changes in the weight of caudae epididymis, prostate, chromosomal aberrations, rate of pregnancy and pre-implantation loss. However, the percent motility, sperm count and morphology of spermatozoa were not affected. Our study on biochemical parameters showed depletion of nucleic acids, NP-SH and increase of MDA, which elucidated the role of free radical species in the induced changes in testis chromosomes and the reproductive function. The exact mechanism is not known, however, the activation of GABA, glycine and glutamate under the influence of Ginkgo biloba and its constituents might have generated free radicals and depleted cellular glutathione by calcium influx and membrane depolarization. The observed toxicity is attributed to the toxic constituents (ginkgolic acids, biflavones, cardanols, cardols, bilobalides and quercetin) of Ginkgo biloba. Our results warrant careful use of Ginkgo biloba as a remedy for impotence and/or erectile dysfunction.

Protection of gastric mucosal damage by Coriandrum sativum L. pretreatment in Wistar albino rats

The effect of Coriander pretreatment on gastric mucosal injuries caused by NaCl, NaOH, ethanol, indomethacin and pylorus ligation accumulated gastric acid secretions was investigated in rats. Pretreatment at oral doses of 250 and 500mg/kg, body weight was found to provide a dose-dependent protection against the (i) ulcerogenic effects of different necrotizing agents; (ii) ethanol-induced histopathological lesions; (iii) pylorus ligated accumulation of gastric acid secretions and ethanol related decrease of Nonprotein Sulfhydryl groups (NP-SH). Results obtained on the study of gastric mucus and indomethacin-induced ulcers demonstrated that the gastro protective activity of Coriander might not be mediated by gastric mucus and/or endogenous stimulation of prostaglandins. The protective effect against ethanol-induced damage of the gastric tissue might be related to the free-radical scavenging property of different antioxidant constituents (linanool, flavonoids, coumarins, catechins, terpenes and polyphenolic compounds) present in Coriander. The inhibition of ulcers might be due to the formation of a protective layer of either one or more than one of these compounds by hydrophobic interactions.

Left ventricular systolic dysfunction after transcatheter closure of a large patent ductus arteriosus

A 12-year-old boy reported in outpatient department with history of shortness of breath and dyspnoea on moderate exertion. Physical examination was significant for bounding pulses and for a continuous murmur III/VI, best heard at the left upper sternal border. Echocardiography confirmed a large patent arterial duct with shortening fraction of 33%. He underwent successful transcatheter closure of the patent arterial, using Amplatzer duct occluder 12/10. Few hours later echocardiography revealed an unexpected, yet important depression of left ventricular systolic function with shortening fraction decreasing to 24% and then two weeks later decreasing further to 20%. At a follow-up after four months, he had improved clinically but left ventricular dysfunction still persisted with shortening fraction of 24%.

Cardiac magnetic resonance imaging after stage I Norwood operation for hypoplastic left heart syndrome

BACKGROUND

After the Norwood operation, a patient's suitability for proceeding to a bidirectional cavopulmonary connection (BCPC) is assessed by a combination of echocardiography and diagnostic cardiac catheterization. In this study, we describe the results of 37 patients who underwent cardiovascular magnetic resonance (MR) assessment before BCPC.

METHODS AND RESULTS

Cardiovascular MR and echocardiography were performed in 37 infants with hypoplastic left heart syndrome before BCPC, and the findings were compared with surgical findings. MR assessment of ventricular function and valvar regurgitation were compared with echocardiography. MR exhibited high sensitivity and specificity for identification of neoaortic (sensitivity 86%, specificity 97%) and left pulmonary artery (sensitivity 100%, specificity 94%) obstruction. Echocardiography exhibited poor sensitivity for identification of vascular stenosis. The mean right ventricular ejection fraction calculated from the MR data was 50+/-10%. There was general agreement between MR and echocardiographic measures of ventricular function, although patients with good function on echocardiography demonstrated a wide range of ejection fractions. There was good agreement between MR and echocardiography for identification of valvar regurgitation.

CONCLUSIONS

Cardiovascular MR can be used to define ventricular and valvar function and vascular anatomy in infants with hypoplastic left heart syndrome after the Norwood operation. We have shown how this information can be used to plan the BCPC and identify any revisions or additional valvar surgery.

In situ DMSO Hydration Measurements of HTS Compound Libraries

Compounds used in high throughput screening (HTS) are typically dissolved in DMSO. These solutions are stored automation-friendly racks of wells or tubes. DMSO is hygroscopic and quickly absorbs water from the atmosphere. When present in DMSO compound solutions, water can accelerate degradation and precipitation. Understanding DMSO hydration in an HTS compound library can improve storage and screening methods by managing the impact of water on compound stability. A non-destructive, acoustic method compatible with HTS has been developed to measure water content in DMSO solutions. Performance of this acoustic method was compared with an optical technique and found to be in good agreement. The accuracy and precision of acoustic measurements was shown to be under 3% over the tested range of DMSO solutions (0% to 35% water by volume) and insensitive to the presence of HTS compounds at typical storage concentrations. Time course studies of hydration for wells in 384-well and 1536-well microplates were performed. Well geometry, fluid volume, well position and atmospheric conditions were all factors in hydration rate. High rates of hydration were seen in lower-volume fills, higher-density multi-well plates and when there was a large differential between the humidity of the lab and the water content of the DMSO. For example, a 1536-well microplate filled with 2microL of 100% DMSO exposed for one hour to a laboratory environment with approximately 40% relative humidity will absorb over 6% water by volume. Understanding DMSO hydration rates as well as the ability to reverse library hydration are important steps towards managing stability and availability of compound libraries.

Topical nonsteroidal anti-inflammatory drugs versus oil of evening primrose in the treatment of mastalgia

OBJECTIVE

To compare oil of evening primrose (OEP) and topical nonsteroidal anti-inflammatory (NSAIDs) with respect to safety, effectiveness, rapidity of response, cost effectiveness and acceptability in the treatment of breast pain.

STUDY DESIGN

An open, non-randomised, comparative study of topical (NSAI) gel versus OEP was carried out, over a period of one year.

PATIENTS AND METHODS

Fifty female patients attending the outpatient department with moderate to severe breast pain were given one of the two agents alternatively, after selection.

RESULTS

Results showed that out of 25 patients treated with OEP, 64% had a clinically significant response after three months of treatment, compared with 92% with topical NSAIDs. Only one patient (4%) had side effects with OEP, while no patient had side effects with topical NSAIDs. Twenty per cent and seventy per cent showed acceptability as far as costs were concerned and mode of administration respectively, with OEP. The acceptability rate was 68% and 96% respectively, with topical NSAIDs.

CONCLUSION

This study has shown topical NSAIDs to be safe, effective, rapid and acceptable mode of treatment for cyclical and non-cyclical mastalgia.

Improving the quality of health care: using international collaboration to inform guideline programmes by founding the Guidelines International Network (G-I-N)

Clinical practice guidelines are regarded as powerful tools to achieve effective health care. Although many countries have built up experience in the development, appraisal, and implementation of guidelines, until recently there has been no established forum for collaboration at an international level. As a result, in different countries seeking similar goals and using similar strategies, efforts have been unnecessarily duplicated and opportunities for harmonisation lost because of the lack of a supporting organisational framework. This triggered a proposal in 2001 for an international guidelines network built on existing partnerships. A baseline survey confirmed a strong demand for such an entity. A multinational group of guideline experts initiated the development of a non-profit organisation aimed at promotion of systematic guideline development and implementation. The Guidelines International Network (G-I-N) was founded in November 2002. One year later the Network released the International Guideline Library, a searchable database which now contains more than 2000 guideline resources including published guidelines, guidelines under development, "guidelines for guidelines", training materials, and patient information tools. By June 2004, 52 organisations from 27 countries had joined the network including institutions from Oceania, North America, and Europe, and WHO. This paper describes the process that led to the foundation of the G-I-N, its characteristics, prime activities, and ideas on future projects and collaboration.

Improving the quality of health care: using international collaboration to inform guideline programmes by founding the Guidelines International Network (G-I-N)

Clinical practice guidelines are regarded as powerful tools to achieve effective health care. Although many countries have built up experience in the development, appraisal, and implementation of guidelines, until recently there has been no established forum for collaboration at an international level. As a result, in different countries seeking similar goals and using similar strategies, efforts have been unnecessarily duplicated and opportunities for harmonisation lost because of the lack of a supporting organisational framework. This triggered a proposal in 2001 for an international guidelines network built on existing partnerships. A baseline survey confirmed a strong demand for such an entity. A multinational group of guideline experts initiated the development of a non-profit organisation aimed at promotion of systematic guideline development and implementation. The Guidelines International Network (G-I-N) was founded in November 2002. One year later the Network released the International Guideline Library, a searchable database which now contains more than 2000 guideline resources including published guidelines, guidelines under development, "guidelines for guidelines", training materials, and patient information tools. By June 2004, 52 organisations from 27 countries had joined the network including institutions from Oceania, North America, and Europe, and WHO. This paper describes the process that led to the foundation of the G-I-N, its characteristics, prime activities, and ideas on future projects and collaboration.

Supranormal renal function in unilateral hydronephrotic kidney can be avoided

INTRODUCTION

There are reports and controversy in the literature of supranormal (defined as >55%) differential renal function (DRF) in the hydronephrotic kidney in children with unilateral hydronephrosis. It is not confirmed whether supranormal DRF is an artifact or a true finding. In patients in whom the relative renal function deteriorates, relief of obstruction becomes surgically necessary and if this artifact can be removed. Supranormal function in an obstructed kidney is confusing and there is no consensus on how to manage these patients. There is no agreement if this is a true entity or an artifact. We wanted to address this issue by reporting our experience.

METHODS

We reviewed all the consecutive cases from August 2000 to October 2001 who were studied in our center with the diagnosis of unilateral renal obstruction for confirmation or evaluation of DRF. All patients had MAG-3 studies that were interpreted by experienced nuclear medicine physicians. The DRF were measured within the first to second minute of the MAG-3 injection. Regions of interest were drawn by the imaging software and the images were corrected for background counts by drawing regions of interest 2 pixels away from the edge of the renal cortex.

RESULTS

Fifty-seven patients were confirmed to be obstructed unilaterally; 41 (72%) patients had obstructive lesions in the left kidney and 16 (28%) in the right kidney. There was no case of supranormal DRF in the obstructed kidneys in our study.

CONCLUSION

The supranormal renal function, as noted in some reports in the literature, was not seen in any patients at our institution. We believe that this entity is an artifact and can be avoided by using MAG-3 and projecting regions of interest by computer software; we plan to start analyzing multiple algorithms in phantoms with different ROI selection for background analysis.

A low-cost intervention for cleaner drinking water in Karachi, Pakistan

OBJECTIVE

To pilot test an inexpensive, home-based water decontamination and storage system in a low-income neighborhood of Karachi.

METHODS

Fifty households received a 20-L plastic water storage vessel with a high-quality spout and a regular supply of diluted hypochlorite solution. Twenty-five control households were recruited. Water samples were collected at baseline and during unannounced follow-up visits 1, 3, 6, and 10 weeks later.

RESULTS

Baseline drinking water samples among intervention households were contaminated with a mean 9397 colony-forming units (cfu)/100 mL of thermotolerant coliforms compared with a mean 10,990 cfu/100 mL from controls. After intervention the mean concentration of thermotolerant coliforms decreased by 99.8% among the intervention households compared with an 8% reduction among controls. Two years after vessel distribution, 34 (68%) of the families were still using the vessel. Thirteen of the households had stopped using their vessel because it had broken after more than 6 months of use, a pattern most consistent with ultraviolet radiation-induced degradation of the plastic.

CONCLUSIONS

In a highly contaminated environment, a specifically designed water storage container and in-home water chlorination was acceptable and markedly improved water quality. Where plastic water vessels will be exposed to substantial sunlight, ultraviolet light stabilizers should be incorporated into the plastic.

Outcome of staged reconstructive surgery for hypoplastic left heart syndrome following antenatal diagnosis

BACKGROUND AND AIMS

Staged reconstructive surgery has radically altered the prognosis of hypoplastic left heart syndrome (HLHS). Antenatal diagnosis allows for appropriate counselling, and time to consider treatment options. We report outcome from a centre where most cases are antenatally diagnosed and delivered on site.

METHODS

Information was collated on 188 consecutive cases of HLHS between 1995 and 2000, including timing of diagnosis, outcome of pregnancy, and age and outcome at each stage of surgery. At Guy's Hospital, 174 cases were diagnosed antenatally, of whom 50 underwent surgery. Fourteen others (five diagnosed antenatally at other centres, and nine diagnosed postnatally) also underwent surgery.

RESULTS

Survival after stage I (the Norwood operation) was 52% (33/64). Postoperative survival after stage II (the hemi-Fontan operation, performed in 29), and stage III (the Fontan operation, performed in 10), was 100%. Two late deaths occurred 3 and 10 months after stage II, giving overall survival of 48% (31/64). At follow up, three children have neurological impairment, and one had poor right ventricular function necessitating cardiac transplantation.

CONCLUSIONS

Antenatal diagnosis allows informed decisions about treatment options, and facilitates preoperative care. Mortality following stage I is high, irrespective of timing of diagnosis, but medium term outcome for survivors is good.

General practitioners' and patients' models of obesity: whose problem is it?

Primary care literature emphasises the importance of agreement and shared models in the consultation. This study compared general practitioners' (GPs') and patients' models of obesity. Questionnaires concerning beliefs about the causes, consequences and solutions to obesity were completed by 89 general practitioners (GPs) and 599 patients from practices across UK. In terms of causes, the results showed that the patients were more likely to attribute obesity to a gland/hormone problem, slow metabolism and stress than the GPs, whereas the GPs were more likely to blame eating too much. In terms of consequences, the patients rated difficulty getting to work more highly whereas the GPs regarded diabetes as more important. For the solutions to obesity, the two groups reported similar beliefs for a range of methods, but whereas the patients rated the GP and a counsellor as more helpful, the GPs rated the obese person themselves more highly. It is argued that patients show a self serving model of obesity by blaming internal uncontrollable factors for causing obesity yet expecting external factors to solve it. In contrast, GPs show a victim blaming model by attributing both cause and the solution to internal controllable factors. Such differing models have implications regarding the form of intervention likely to be used in primary care and indicate that whereas patients would prefer a more professional based approach, GPs would prefer a more patient-led one. Further, the results suggest that even if an intervention could be negotiated, success rates would be low as either the patient or the GP would be acting in contradiction to their beliefs about the nature of obesity.

Boric acid enhances in vivo Ehrlich ascites carcinoma cell proliferation in Swiss albino mice

The influence of boric acid, a boron carrier, on Ehrlich ascites carcinoma (EAC) cell-bearing mice was investigated in view of its importance in the boron neutron capture therapy and the influence of boron on proliferation and progression of cancer cells mediated by proteoglycans and collagen. The present study included the evaluation of boric acid for the effects on total count and viability of EAC cells in addition to their non-protein sulfhydryls (NP-SH) and malondialdehyde (MDA) contents as parameters for conjugative detoxication potency and possible oxidative damage. The EAC cell-bearing animals were also observed for the effect on survival, body weight changes, and histopathological evaluation of the tumors grown at the site of inoculation. The treatment with boric acid significantly increased the total number of peritoneal EAC cells and their viability. A significant increase in the body weight was observed that dose-dependently reached plateau levels by 20 days of treatment. Conversely, a reduction in the duration of survival of these animals was evident with the same protocol. Boric acid treatment resulted in a decrease in NP-SH contents with a concomitant increase in MDA levels in EAC cells as revealed by the results of the biochemical analysis. These data are supported by our results on histopathological investigations, which apparently showed fast growth, in addition to several mitotic figures and mixed inflammatory reaction, after treatment with boric acid. It seems likely that a particular combination of properties of boric acid, rather than a single characteristic alone, will provide useful information on the use of this boron carrier in neutron capture therapy.

Thermoregulatory and In-vivo Anti-inflammatory Effects of Vigabatrin In Rat and Mice

Effects of acute administration of vigabatrin (VGB) that has significant GABA-mimetic properties were studied for its antiinflammatory, antigranuloma effects in rats and thermoregulatory actions in mice. Treatment of rats with VGB (125, 250 and 500 mg/kg, i.p doses) caused a significant and persistent inhibition in the carrageenan induced paw edema. Inhibitory effect at high dose (500 mg/kg, which was about 10-fold of the maximal effective dose 50 mg/kg in humans) was 40-, 41- and 39% of the control at 2-, 3- and 4 hours afier the treatment. In cotton-pellet-granuloma study, only the high dose was significantly (P<0.05) effective and inhibition in granuloma was 17 and 28% of the control at 250 and 500 mg/kg doses, respectively. In another model, leukocyte migration to the inflamed peritoneal cavity was used as a parameter in rats. In this model, VGB (500 mg/kg, i.p) induced a significant (P<0.05) reduction in leukocyte migration to the inflamed peritoneal cavity when administered 30 min before carrageenan. This was comparable to indomethacin (10 mg/kg) that also caused a significant (P<0.05) reduction in leukocyte migration. The inhibition in the leukocyte migration was 66 and 61% with VGB and indomethacin, respectively. In thermoregulation studies, the rectal temperature of normothermic mice declined dose dependently. In another part of this study all the doses of VGB induced a significant reduction in body temperature at 45 min following drug administration in yeast-induced hyperpyrexic mice. The hypothermic response diminished after 90 min, 3 hours and 6 hours of treatment at 125, 250 and 500 mg/kg doses respectively and none of the dose showed any change in rectal temperature at 24-hour study point. The results of the present study indicate that vigabatrin has the potential to induce anti-edema, antigranuloma and leukocyte anti-migratory effects in inflamed peritoneal cavity and reduce the rectal temperature in normothermic as well as hyperthermia-induced mice with acute regimen. These effects are thought to be the result of GABA accumulation, its interaction with PG biosynthesis and other neuromediators.

A European multicentric experience using the CardioSEal and Starflex double umbrella devices to close interatrial communications holes within the oval fossa

In this review, we describe the experience from 13 European centres using the CardioSEAL and Starflex double umbrella devices to close interatrial communications within the oval fossa (so-called 'secundum' defects). Between October 1996 and April 1999, the procedure was attempted in 334 patients with a mean age of 12 years and a mean weight of 44kg. The mean measured stretched diameter of the defect was 15 mm. In the overall group, the defect was solitary in 245 patients (73%), multiple in 21 (6%), associated with an aneurysm of the flap valve in 15 (5 %), was represented by patency of the oval foramen in 44 (13%), and was a fenestration in a Fontan repair in 9 (3%). In all patients, the devices were inserted under general anesthesia, using fluoroscopic and transesophageal echocardiographic control. Implantation was achieved in 325 (97,3%). The device embolized within either a few minutes or a few hours in 13 patients (4%). Of these, uncomplicated surgical repair was undertaken in 10, while the device was retrieved in 3 using catheters and a second device was successfully implanted. Residual shunting was detected immediately after the procedure in 41% of the patients, with the incidence decreasing to 31% at discharge, 24% at 1 month, 21% at 6 months, and 20.5% at one year. During the period of follow-up, elective surgical repair became necessary in two patients, due to malposition of the device in one, and late embolization in the other. Fractures of arms were seen in 6.1 %, most commonly with the largest devices. All those with fractured arms of the device were asymptomatic, and no clinical complications related to the fractures were observed. There were no arrhythmias, endocarditis, valvar distortion, thromboembolic events, or other complications. After one year of follow-up, clinical success, defined as complete closure of the defect or presence of only a trivial leak, had been obtained in 92.5% of the patients. We conclude, therefore, that these devices produce excellent results when used to close defects of small to moderate size. Results are less than optimal, or else complications ensure, when attempts are made to close very large defects.