Early-Life Environmental Exposures and Blood Pressure in Children

BACKGROUND

Growing evidence exists about the fetal and environmental origins of hypertension, but mainly limited to single-exposure studies. The exposome has been proposed as a more holistic approach by studying many exposures simultaneously.

OBJECTIVES

This study aims to evaluate the association between a wide range of prenatal and postnatal exposures and blood pressure (BP) in children.

METHODS

Systolic and diastolic BP were measured among 1,277 children from the European HELIX (Human Early-Life Exposome) cohort aged 6 to 11 years. Prenatal (n = 89) and postnatal (n = 128) exposures include air pollution, built environment, meteorology, natural spaces, traffic, noise, chemicals, and lifestyles. Two methods adjusted for confounders were applied: an exposome-wide association study considering the exposures independently, and the deletion-substitution-addition algorithm considering all the exposures simultaneously.

RESULTS

Decreases in systolic BP were observed with facility density (β change for an interquartile-range increase in exposure: -1.7 mm Hg [95% confidence interval (CI): -2.5 to -0.8 mm Hg]), maternal concentrations of polychlorinated biphenyl 118 (-1.4 mm Hg [95% CI: -2.6 to -0.2 mm Hg]) and child concentrations of dichlorodiphenyldichloroethylene (DDE: -1.6 mm Hg [95% CI: -2.4 to -0.7 mm Hg]), hexachlorobenzene (-1.5 mm Hg [95% CI: -2.4 to -0.6 mm Hg]), and mono-benzyl phthalate (-0.7 mm Hg [95% CI: -1.3 to -0.1 mm Hg]), whereas increases in systolic BP were observed with outdoor temperature during pregnancy (1.6 mm Hg [95% CI: 0.2 to 2.9 mm Hg]), high fish intake during pregnancy (2.0 mm Hg [95% CI: 0.4 to 3.5 mm Hg]), maternal cotinine concentrations (1.2 mm Hg [95% CI: -0.3 to 2.8 mm Hg]), and child perfluorooctanoate concentrations (0.9 mm Hg [95% CI: 0.1 to 1.6 mm Hg]). Decreases in diastolic BP were observed with outdoor temperature at examination (-1.4 mm Hg [95% CI: -2.3 to -0.5 mm Hg]) and child DDE concentrations (-1.1 mm Hg [95% CI: -1.9 to -0.3 mm Hg]), whereas increases in diastolic BP were observed with maternal bisphenol-A concentrations (0.7 mm Hg [95% CI: 0.1 to 1.4 mm Hg]), high fish intake during pregnancy (1.2 mm Hg [95% CI: -0.2 to 2.7 mm Hg]), and child copper concentrations (0.9 mm Hg [95% CI: 0.3 to 1.6 mm Hg]).

CONCLUSIONS

This study suggests that early-life exposure to several chemicals, as well as built environment and meteorological factors, may affect BP in children.

The IL-4 rs2070874 polymorphism may be associated with the severity of recurrent viral-induced wheeze

BACKGROUND

Childhood recurrent wheezing and consequently asthma corresponds to various phenotypes. Our aim was to link genetic variants of asthma candidate genes to the phenotypes of early onset wheezing.

STUDY DESIGN

We included very young consecutive children presenting with recurrent wheezing who had been evaluated for the severity of wheezing, associated atopic comorbidities, and tested for biomarkers of atopy and inflammation. All were genotyped for 16 single nucleotide polymorphisms (SNPs) linked with asthma or atopy. An unsupervised hierarchical bottom-up method was used for clustering the phenotypes and a multinomial logistic regression was performed for each individual SNP.

RESULTS

We replicated the three phenotypes previously described Trousseau Asthma Program in 317 children aged 21.5 ± 7.9 months: cluster 1 (nonatopic uncontrolled severe wheeze), n = 207, a severe viral-induced wheeze, cluster 2 (atopic multiple trigger wheeze), n = 61, with multiple allergic comorbidities, and cluster 3 (episodic viral wheeze), n = 49, a mild viral-induced wheeze. The TT-genotype of the IL-4 rs2070874 polymorphism was significantly associated with the nonatopic uncontrolled severe wheeze compared to the episodic viral wheeze (OR 7.9; CI95% [2.5-25.3]; P = 0.001).

CONCLUSION

Association between the TT-genotype of IL-4 rs2070874 polymorphism and a severe phenotype of viral-induced wheeze further underlines the role IL-4 plays in the inflammation pathway leading to viral respiratory infections.

Genome-wide association study of body mass index in 23 000 individuals with and without asthma

BACKGROUND

Both asthma and obesity are complex disorders that are influenced by environmental and genetic factors. Shared genetic factors between asthma and obesity have been proposed to partly explain epidemiological findings of co-morbidity between these conditions.

OBJECTIVE

To identify genetic variants that are associated with body mass index (BMI) in asthmatic children and adults, and to evaluate if there are differences between the genetics of BMI in asthmatics and healthy individuals.

METHODS

In total, 19 studies contributed with genome-wide analysis study (GWAS) data from more than 23 000 individuals with predominantly European descent, of whom 8165 are asthmatics.

RESULTS

We report associations between several DENND1B variants (P = 2.2 × 10(-7) for rs4915551) on chromosome 1q31 and BMI from a meta-analysis of GWAS data using 2691 asthmatic children (screening data). The top DENND1B single nucleotide polymorphisms(SNPs) were next evaluated in seven independent replication data sets comprising 2014 asthmatics, and rs4915551 was nominally replicated (P < 0.05) in two of the seven studies and of borderline significance in one (P = 0.059). However, strong evidence of effect heterogeneity was observed and overall, the association between rs4915551 and BMI was not significant in the total replication data set, P = 0.71. Using a random effects model, BMI was overall estimated to increase by 0.30 kg/m(2) (P = 0.01 for combined screening and replication data sets, N = 4705) per additional G allele of this DENND1BSNP. FTO was confirmed as an important gene for adult and childhood BMI regardless of asthma status.

CONCLUSIONS AND CLINICAL RELEVANCE

DENND1B was recently identified as an asthma susceptibility gene in a GWAS on children, and here, we find evidence that DENND1B variants may also be associated with BMI in asthmatic children. However, the association was overall not replicated in the independent data sets and the heterogeneous effect of DENND1B points to complex associations with the studied diseases that deserve further study.

Influence of fetal glutathione S-transferase copy number variants on adverse reproductive outcomes

A nested case-control association study was designed to investigate the influence of maternal and fetal copy number variants (CNVs) on reproductive outcomes. Genotypes of ten CNVs encompassing GST and CYP genes were assessed. Significant associations were only found for child CNV genotypes. In particular, the child GSTM1 insertion allele was associated with prematurity protection (odds ratio, 95% CI: 0.67, 0.51-0.89; P < 0.01), whereas the child GSTT2B insertion allele was associated with an increased risk of being small for gestational age (odds ratio, 95% CI: 1.33, 1.07-1.67; P = 0.01). The study highlights the role of the fetal genome in prenatal development and also the need to analyse CNVs in a systematic manner.

Positionally cloned genes and age-specific effects in asthma and atopy: an international population-based cohort study (ECRHS)

BACKGROUND

Several genes identified by positional cloning have been associated with asthma and atopy, but few findings have been replicated. Age at onset of asthma has been associated with different phenotypic characteristics, and with variants at chromosome 17q21 identified through genome-wide association. This study examined the associations and age-specific effects on asthma, atopy and bronchial hyper-responsiveness (BHR) of five candidate genes previously identified by positional cloning (ADAM33, PHF11, NPSR1, DPP10, SPINK5).

METHODS

51 polymorphisms from 2474 participants from 13 countries who took part in the European Community Respiratory Health Survey (1990-2000) were studied. Asthma and age at onset of asthma were assessed by questionnaire data, BHR by methacholine challenge and atopy by specific immunoglobulin E to four common allergens.

RESULTS

Significant associations with asthma, atopy and particularly for asthma with atopy were observed for a large region of 47 kb in the NPSR1 gene, even after Bonferroni correction for multiple comparisons (p<0.001). The associations with NPSR1 were stronger in those reporting a first attack of asthma before the age of 15, with statistically significant interactions with age of onset found for three SNPs. The evidence for ADAM33 and BHR and for an age-specific effect of two SNPs in DPP10 and asthma was weaker.

CONCLUSION

This study provides further evidence for an effect of NPSR1 on asthma, atopy and atopic asthma. In addition, this analysis suggests a role for NPSR1 in early-onset asthma driven by the strong effect of this gene on atopic asthma.

Joint effect of obesity and TNFA variability on asthma: two international cohort studies

Obesity is a risk factor for asthma. Adipose tissue expresses pro-inflammatory molecules including tumour necrosis factor (TNF), and levels of TNF are also related to polymorphisms in the TNF-alpha (TNFA) gene. The current authors examined the joint effect of obesity and TNFA variability on asthma in adults by combining two population-based studies. The European Community Respiratory Health Survey and the Swiss Cohort Study on Air Pollution and Lung and Heart Disease in Adults used comparable protocols, questionnaires and measures of lung function and atopy. DNA samples from 9,167 participants were genotyped for TNFA -308 and lymphotoxin-alpha (LTA) +252 gene variants. Obesity and TNFA were associated with asthma when mutually adjusting for their independent effects (odds ratio (OR) for obesity 2.4, 95% confidence interval (CI) 1.7-3.2; OR for TNFA -308 polymorphism 1.3, 95% CI 1.1-1.6). The association of obesity with asthma was stronger for subjects carrying the G/A and A/A TNFA -308 genotypes compared with the more common G/G genotype, particularly among nonatopics (OR for G/A and A/A genotypes 6.1, 95% CI 2.5-14.4; OR for G/G genotype 1.7, 95% CI 0.8-3.3). The present findings provide, for the first time, evidence for a complex pattern of interaction between obesity, a pro-inflammatory genetic factor and asthma.

Brain-derived neurotrophic factor modulates the severity of cognitive alterations induced by mutant huntingtin: involvement of phospholipaseCgamma activity and glutamate receptor expression

The involvement of brain-derived neurotrophic factor (BDNF) in cognitive processes and the decrease in its expression in Huntington's disease suggest that this neurotrophin may play a role in learning impairment during the disease progression. We therefore analyzed the onset and severity of cognitive deficits in two different mouse models with the same mutant huntingtin but with different levels of BDNF (R6/1 and R6/1:BDNF+/- mice). We observed that BDNF modulates cognitive function in different learning tasks, even before the onset of motor symptoms. R6/1:BDNF+/- mice showed earlier and more accentuated cognitive impairment than R6/1 mice at 5 weeks of age in discrimination learning; at 5 weeks of age in procedural learning; and at 9 weeks of age in alternation learning. At the earliest age at which cognitive impairment was detected, electrophysiological analysis was performed in the hippocampus. All mutant genotypes showed reduced hippocampal long term potentiation (LTP) with respect to wild type but did not show differences between them. Thus, we evaluated the involvement of BDNF-trkB signaling and glutamate receptor expression in the hippocampus of these mice. We observed a decrease in phospholipaseCgamma activity, but not ERK, in R61, BDNF+/- and R6/1:BDNF+/- hippocampus at the age when LTP was altered. However, a specific decrease in the expression of glutamate receptors NR1, NR2A and GluR1 was detected only in R6/1:BDNF+/- hippocampus. Therefore, these results show that BDNF modulates the learning and memory alterations induced by mutant huntingtin. This interaction leads to intracellular changes, such as specific changes in glutamate receptors and in BDNF-trkB signaling through phospholipaseCgamma.

TNFA -308G>A in two international population-based cohorts and risk of asthma

Genetic association studies have related the tumour necrosis factor-alpha gene (TNFA) guanine to adenine substitution of nucleotide -308 (-308G>A) polymorphism to increased risk of asthma, but results are inconsistent. The aim of the present study was to test whether two single-nucleotide polymorphisms, of TNFA and of the lymphotoxin-alpha gene (LTA), are associated with asthma, bronchial hyperresponsiveness and atopy in adults, by combining the results of two large population-based multicentric studies and conducting a meta-analysis of previously published studies. The European Community Respiratory Health Survey (ECRHS) and Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) used comparable protocols, including questionnaires for respiratory symptoms and measures of lung function and atopy. DNA samples from 11,136 participants were genotyped at TNFA -308 and LTA 252. Logistic regression employing fixed and random effects models and nonparametric techniques were used. The prevalence of asthma was 6%. The TNFA -308G>A polymorphism was associated with increased asthma prevalence and with bronchial hyperresponsiveness. No consistent association was found for atopy. The LTA 252A>G polymorphism was not associated with any of the outcomes. A meta-analysis of 17 studies showed an increased asthma risk for the TNFA -308 adenine allele. The tumour necrosis factor-alpha gene nucleotide -308 polymorphism is associated with a moderately increased risk of asthma and bronchial hyperresponsiveness, but not with atopy. These results are supported by a meta-analysis of previously published studies.

Dopaminergic deficiency in mice with reduced levels of the dual-specificity tyrosine-phosphorylated and regulated kinase 1A, Dyrk1A(+/-)

The dual-specificity tyrosine-phosphorylated and regulated kinase 1A (DYRK1A) gene encodes a protein kinase known to play a critical role in neurodevelopment. Mice with one functional copy of Dyrk1A (Dyrk1A(+/-)) display a marked hypoactivity and altered gait dynamics in basal conditions and in novel environments. Dopamine (DA) is a key neurotransmitter in motor behavior and genetic deletion of certain genes directly related to the dopaminergic system has a strong impact on motor activity. We have studied the effects of reduced Dyrk1A expression on the function of the nigrostriatal dopaminergic system. To characterize the dopaminergic system in DYRK1A(+/-) mice, we have used behavioral, pharmacological, histological, neurochemical and neuroimaging (microPET) techniques in a multidisciplinary approach. Dyrk1A(+/-) mice exhibited decreased striatal DA levels, reduced number of DA neurons in the substantia nigra pars compacta, as well as altered behavioral responses to dopaminergic agents. Moreover, microdialysis experiments revealed attenuated striatal DA release and positron emission tomography scan display reduced forebrain activation when challenged with amphetamine, in Dyrk1A(+/-) compared with wild-type mice. These data indicate that Dyrk1A is essential for a proper function of nigrostriatal dopaminergic neurons and suggest that Dyrk1A(+/-) mice can be used to study the pathogenesis of motor disorders involving dopaminergic dysfunction.

Monitoring falls in gastric cancer mortality in Europe

We have considered trends in age-standardized mortality from gastric cancer in 25 individual European countries, as well as in the European Union (EU) as a whole, in six selected central-eastern European countries and in the Russian Federation over the period 1950-1999. Steady and persisting falls in rates were observed, and the fall between 1980 and 1999 was approximately 50% in the EU, 45% in eastern Europe and 40% in Russia. However, the declines were greater in Russia and eastern Europe, since rates were much higher, in absolute terms. Joinpoint regression analysis indicated that the falls were proportionally greater in the last decade for men (-3.83% per year in the EU) and in the last 25 years for women (-3.67% per year in the EU) than in previous calendar years. Moreover, steady declines in gastric cancer mortality were observed in the middle-aged and the young population as well, suggesting that they are likely to persist in the near future. In terms of number of deaths avoided, however, the impact of the decline in gastric cancer mortality will be smaller, particularly in the EU.

Trends in Childhood Cancer Incidence and Mortality in Catalonia, Spain, 1975–1998

Childhood cancer mortality has sharply declined in most economically developed countries over the last years, whereas no substantial changes in the incidence have been observed. In Catalonia (Spain), childhood cancer mortality showed a considerable decline until 1992, but incidence trends have not been analysed in this population. To assess both recent incidence and mortality trends in this population, we analysed childhood (0-14 years) cancer data from the population-based Tarragona Cancer Registry and from the Mortality Registry of Catalonia (Spain) from 1980 to 1998. All cancer mortality decreased by -2.6% annually in boys (95% confidence interval, 95% CI -3.7, -1.6) and -3.7% in girls (95% CI -4.9, -2.5). Mortality due to leukaemia decreased annually -3.0% in boys (95% CI -4.7, -1.4) and -4.4% in girls (95% CI -6.3, -2.4). Mortality for brain tumours showed a reduction of -3.2% in boys (95% CI -5.5, -0.9) and of -4.4% in girls (95% CI -6.3, -2.4). No significant trend in incidence rates, either in boys or in girls, was observed (annual per cent of change for all cancers -0.5%, 95% CI -3.5, 2.7, in boys and 1.7%, 95% CI -1.9, 5.5, in girls). These results suggest an improvement in both childhood cancer diagnosis and treatment, which may explain current higher childhood cancer survival rates.

Sensorineural deafness in two infants: a novel feature in the 22q distal duplication syndrome. Cardinal signs in trisomies 22 subtypes

Sensorineural deafness in two infants: a novel feature in the 22q distal duplication syndrome. cardinal signs in trisomies 22 subtypes: Distal trisomy 22 has been described in more than 15 individuals. The features are severe mental and growth retardation, failure to thrive, congenital hypotonia, hydrocephalus, microcephaly, cleft palate, epicanthic folds, low-set ears, broad prominent nasal bridge, long philtrum, micrognathia, finger-like thumbs, cryptorchidism. We describe a girl deceased at the age of 12 years and an 11 year old boy, both with a duplication of distal 22q due to a parental pericentric inversion (22) (p13q12). Their phenotypes are compatible with distal trisomy of chromosome 22. However, they did not present cleft palate, but the survival of both patients permitted us to discover sensorineural deafness not previously reported in this chromosomal duplication.

Lung cancer mortality in European regions (1955-1997)

BACKGROUND

The different spread of tobacco smoking across European countries has caused a substantial variability in lung cancer mortality. The objective of this investigation was to analyse the trends in lung cancer mortality rates in three broad European regions (Northern and Western countries, Eastern countries, and Mediterranean countries) during the second half of the 20th century.

PATIENTS AND METHODS

Mortality data were obtained from the World Health Organisation database. Lung cancer mortality rates were age-standardised by the direct method to the world standard population. Trends from 1955 to 1997 were assessed by means of joinpoint regression analysis.

RESULTS

In men, rates in Eastern Europe increased to reach in the 1990s the highest values ever registered, while downward trends were observed in Northern and Western Europe since 1979, and in Mediterranean countries since the 1990s. In women, upward trends were observed in the three regions considered for the whole period.

CONCLUSIONS

Different smoking prevalences over time explain the shift of almost one decade in the trends in Mediterranean men as compared with Northern and other Western European men. The persisting upward trends in women in the three regions are of concern.

Do corticosteroids add any benefit to standard GVHD prophylaxis in allogeneic BMT?

In a retrospective study, we compared 15 patients who received cyclosporine (CsA), methotrexate (MTX) and prednisone (PDN) and 15 patients who received CsA-MTX for GVHD prophylaxis after allogeneic BMT (HLA-identical sibling (n = 22), related one HLA mismatch (n = 1), unrelated matched donors (n = 6), unrelated one HLA mismatch (n = 1)). The primary objectives of this study were to compare the incidence of GVHD and post-transplantation complications. Secondary objectives were to compare relapse rate, transplant-related mortality and overall survival. The incidence of acute GVHD grade III-IV was similar between the two groups (P = 0.66), as was the incidence of chronic GVHD (P = 0.67). Incidence of arterial hypertension was significantly higher in patients who received prophylactic PDN, (P = 0.03) and more insulin treatment was required in this group (P = 0.003). We observed no differences in the incidence of infections or upper digestive tract bleeding. Musculoskeletal complications appeared earlier in the group which received PDN. With a median follow-up of 4.4 years, patients in the CsA-MTX group had better overall survival, 46.7% vs 13.3% (P = 0.026). Relapse was a more frequent cause of death in the CsA-MTX group, whereas procedure-related mortality was more frequent in the CsA-MTX-PDN group (P = 0.013). These results suggest that prophylactic prednisone when combined with cyclosporine and methotrexate adds no benefit in acute or chronic GVHD prevention and may increase the morbidity of allogeneic transplantation. Corticosteroids may be reserved for GVHD treatment.

Sentinel node biopsy as a practical alternative to axillary lymph node dissection in breast cancer patients: an approach to its validity

BACKGROUND

Sentinel node biopsy (SNB) has been proposed as an alternative to axillary lymph-node dissection (ALND) in breast cancer. Before implementing SNB in our practice, we wished to test its validity by comparing it to the standard ALND, both in our hands and with other reported series.

PATIENTS AND METHODS

One hundred thirty-two patients were included prospectively. SNB and immediate ALND were performed. For SNB, a technetium-colloid was used to produce preoperative lymphoscintigraphy and intraoperative gamma-probe search for the SN. Serial sectioning and immunostains were used on the SN. A comprehensive review of the literature was done in order to run a meta-analysis of diagnostic tests using a summary receiver operating characteristic curve (SROC) to calculate the pooled parameters of sensitivity and associated 95% confidence interval (95% CI), including our own data.

RESULTS

Our technical success rate was 96%. Local sensitivity was 96%, with a 95% CI from 85%-99%. Seven patients were upstaged by the SNB. A literature search identified 18 studies published from 1996-1999. Estimates of sensitivity ranged from 83%-100%. The pooled data meta-analysis gave a global sensitivity of 91%, with a 95% CI from 89%-93%. The area under the global SROC curve was 0.9967.

CONCLUSIONS

The minimally invasive SNB was shown to be a practical alternative to ALND. We propose to use local as well as global sensitivity and associated 95% CI to test the validity of SNB in the clinical setting. Due to limitations of ALND as the golden standard, SNB can in fact be considered a more accurate method for nodal staging.

Blind persons navigate in virtual reality (VR); hearing and feeling communicates "reality"

Can Virtual Reality (VR) developments in audio navigation for blind persons support therapies for all? Working with Crystal River Engineering we are developing navigable Virtual Reality worlds for blind users, using spatialized audio [1], [2]. All persons, however, use specialized channels, such as: visual, aural, and kinetic learning senses. Predominantly visual VR worlds and health informatics models from World Wide Webs, may be downloaded, tailored, augmented, and delivered to each of these learning senses using VR. We are also testing a proof of concept system with Boston Dynamics which downloads 3-dimensional, satellite-derived map models from the World Wide Web, and makes them navigable by "feeling" the terrain using haptic (tactual or force feedback to your hand) robotic interfaces. Ultimately, these multi-sensory VR access methods: sight, localization by audio, and "feeling" of data sets could open up the World Wide Web to individuals with sight impairments. This could also, however, benefit government, businesses, universities, and (elementary) education. It could contribute more powerful communications, education, and medical simulation applications on the World Wide Web. This work is part of government technology transfer to telemedicine, (elementary) education, disabilities access to the Web, and new Internet access and productivity efforts under Vice President Gore's National Performance Review.

Pharmacokinetics and safety of transcorneal iontophoresis of tobramycin in the rabbit

Transcorneal iontophoresis of tobramycin in normal eyes of New Zealand white rabbits was compared to an eye cup control and application of fortified topical drops. Iontophoresis was performed with 25 mg/ml of tobramycin at 0.8 mAmps for 10 or 5 min. The eye cup with 25 mg/ml of tobramycin was placed on the eye for 10 min without current. Topical fortified drops (13.6 mg/ml) were applied every half hour for 4 hr. Epithelium, stroma, and aqueous humor were assayed separately at 1, 4, 8 and 16 hr after treatment. The eyes were examined using the slit-lamp biomicroscope before and immediately after the treatment, and prior to sacrifice. Two eyes were examined by light and scanning electron microscopy 5 and 10 min after iontophoresis. Iontophoresis yielded significantly higher tobramycin concentrations than the eye cup or fortified topical drops at 1 hr and 4 hr after treatment (P = 0.001). In all treated eyes, iontophoresis resulted in epithelial edema and mucous discharge, which resolved by 24 hr after the treatment. Histologically there was evidence of epithelial disruption in the superficial layer after 5 min of iontophoresis and in all layers of the epithelium after 10 min of iontophoresis. Iontophoresis is a relatively safe, effective method to deliver medications to ocular tissues and may be useful alone or as an adjunct to current modes of antimicrobial chemotherapy.

Iontophoresis of tobramycin for the treatment of experimental Pseudomonas keratitis in the rabbit

Iontophoresis of tobramycin sulfate was employed to treat bacterial keratitis induced in rabbits by an intrastromal injection of Pseudomonas aeruginosa. Quantitation of bacterial killing was achieved by culturing corneal homogenates and counting viable bacteria per cornea after treatment. When the rabbits received two iontophoretic treatments, iontophoresis significantly reduced the number of bacterial colony-forming units, compared with the use of an eyecup without current or two subconjunctival injections of 20 mg of tobramycin sulfate, and with untreated controls. The results of iontophoresis were not significantly different from those involving treatment with topical fortified drops (40 mg/mL). A single iontophoresis treatment was compared with the use of an eyecup without current or less fortified topical drops (13.6 mg/mL), as well as with untreated controls. Iontophoresis was significantly better than either the eyecup or the topical fortified tobramycin drops in reducing viable bacteria in the corneas. Iontophoresis may be a useful adjunct in the treatment of severe corneal bacterial infections.